A 50-Day Heat Wave Forecast, and the Future of Subseasonal to Seasonal Prediction

By: Bob Henson , 6:50 PM GMT on March 29, 2016

For those of us interested in the future of long-range weather forecasting, two developments this week pair very nicely. A paper published on Monday online in the journal Nature Geoscience shows how heat waves across the midwestern and eastern U.S. may be predictable with some skill as far as 50 days out. On its heels is the Tuesday release of a report from the U.S. National Academies, Next Generation Earth System Prediction: Strategies for Subseasonal to Seasonal Forecasts. The report argues that there is great potential to improve the quality and value of forecasts in the two-week to 12-month range, if the necessary resources can be marshaled--and if researchers can develop and tailor products designed to fit the needs of users.

The Pacific Extreme Pattern: A prelude to big heat in the central and eastern U.S.
The paper in Nature Geoscience--led by Karen McKinnon, a postdoctoral researcher at the National Center for Atmospheric Research--finds that a particular arrangement of sea surface temperature (SST) can take shape across the North Pacific weeks ahead of the advent of widespread summer heat over much of the central and eastern U.S. This oceanic configuration, dubbed the Pacific Extreme Pattern (PEP), features colder-than-usual SSTs along the west coast of North America, with a warmer-than-usual area north of Hawaii and another cold anomaly toward Japan (Figure 1).

The PEP bears some of the hallmarks of the negative (cold) phase of the Pacific Decadal Oscillation, which is known to raise the odds of drought and heat across parts of the United States. However, the PDO and PEP are separate beasts, according to McKinnon. “PEP has a smaller spatial scale and varies more within a season than the PDO,” said McKinnon in an email. “While in some cases SST anomalies may project similarly onto both patterns, we do not believe that they are generally the same phenomenon.”


Figure 1. Colored areas show anomalies (departures from average) in sea surface temperature associated with the Pacific Extreme Pattern (PEP) at the 40-day lead time, when it would suggest an enhanced risk of heat 40 days later over the central and eastern U.S. Overlaid in dashed and solid black contours are the Pacific Decadal Oscillation (PDO). While a negative PDO is defined by a large warm anomaly that spans most of the North Pacific (solid contours), with a cold tongue near the western U.S. (dashed contours), the PEP has a large cold anomaly in the western part of the ocean basin (blue colors), a smaller warm anomaly in the middle part of the basin, and then a second cold anomaly in the eastern part of the basin. Image credit: Karen McKinnon, NCAR.


Figure 2. The five clusters of stations across the U.S. identified as tending to experience hot days at the same time. The cluster examined in this study (blue stations] covers much of the central and eastern U.S. Image credit: Fig. S1(a) from K.A. McKinnon et al., Long-lead predictions of eastern United States hot days from Pacific sea surface temperatures, published online on March 28, 2016, in Nature Geoscience.


By exploring where unusually hot U.S. summer temperatures tend to cluster, the study team decided to focus on a large and important region extending from the Central Plains and encompassing most of the nation east of the Mississippi River and north of Florida (see Figure 2). As the PEP evolves in a sequence of steps identified by the authors, it tends to generate high pressure off the West Coast and, further downstream, dry, hot weather over the central and eastern U.S. On a regional basis, the paper defines a hot day as one where at least 5% of the study area (at least 80 of 1613 weather stations) experiences a high of at least 6.5°C (11.7°F) above average (one standard deviation). Using this yardstick, the evolution of the PEP provides significant skill at predicting the timing of hot days for the region as a whole up to 50 days in advance. Even at the individual-station level, the PEP demonstrates significant skill at about half of all locations out to 40 days, particularly across the Mississippi Valley.


Figure 3. SST anomalies in the North Pacific Ocean 50 days in advance of June 29, 2012. The pattern inside the green box best matches the early stage of the Pacific Extreme Pattern, indicating that there would be an increase in the odds of a heat wave in the eastern half of the United States at the end of June. Temperatures on June 29 (bottom) largely bore out the forecast, with readings above 100°F covering much of the Central Plains and mid-Mississippi Valley. Image credit: Karen McKinnon, NCAR.


Hints in May of heat in July
The authors make their case further through a retroactive “hindcast” of the scorching U.S. summer of 2012, which produced record heat and grinding drought across much of the study domain. The three biggest multi-day summer heat spikes of 2012 began on June 25, July 16, and 29 July. The state of the PEP on May 15 corresponded to a more-than-threefold increase in the likelihood of hot days 40 days later (June 24). At the end of May, the PEP indicated even stronger 40-day odds for a hot period around July 9.

Clearly, the PEP is not a perfect predictor, but it may serve as an useful new avenue toward probabilistic heat and drought forecasts over a key part of the U.S., with more specific timing than now offered by today’s leading techniques. “The Pacific Extreme Pattern appears to provide a cohesive framework for improving seasonal prediction of summer precipitation deficits and high temperature anomalies in the eastern U.S.” the paper asserts. “The identification of predictive skill at a seven-week lead time is an important advance over current seasonal forecast models that tend to under-predict the probability of extremes.” It’s possible that the PEP is associated with one or more factors that also influence eastern U.S. heat and dryness. The authors add that “it would be useful to better determine whether the ocean forces, feed backs on, or simply acts as a passive recorder of atmospheric anomalies in the months preceding hot weather.”

Dr. Todd Crawford, chief meteorologist at The Weather Company, said: “These results confirm the importance of North Pacific SST patterns in modulating summer temperature patterns over the US on seasonal time scales, and for the first time suggest predictability of extreme heat events on sub-seasonal time scales.  There is now the potential for the addition of another useful statistical forecasting technique to accompany dynamical model output in the sub-seasonal forecaster's toolbox.” Crawford, whose TWC Energy group carries out seasonal and sub-seasonal prediction for a range of customers, told me he’s being “peppered with client questions/comments” about the paper.

Going operational (experimentally)
We’ll soon find out how well this new technique works in real time. Based on daily PEP calculations, McKinnon and colleagues are planning to make predictions for this summer, beginning in early May. These forecasts will be available through a link to be posted at McKinnon’s website. “Our hope is that these can be used directly by, e.g., city leaders to ensure that enough cooling rooms are available for those without air conditioning if there are increased odds of a heat wave, and utility companies who may want to make sure they have sufficient power to bring online in case of spikes in electricity demand,” McKinnon told me. “We also hope to interface with operational and seasonal forecasters to see if the information from PEP could complement that provided by the current dynamical models.”


Figure 4. Leniel Fields of K&K Maintenance wipes his face in the heat as he trims and maintains the grounds at the Franklin School Apartments near downtown St. Louis on July 23, 2012. The city hit 106°F that day, with temperatures remaining above 80°F at night for three consecutive days. Image credit: AP Photo/St. Louis Post-Dispatch, Erik M. Lunsford.

A comprehensive strategy for improving forecasts up to a year out
The PEP study is one step in a direction encouraged by the National Academies report released on Tuesday. This report serves as an update to a similarly themed 2010 study, Assessment of Intraseasonal to Interannual Climate Prediction and Predictability, this time dropping the multi-year component and focusing on the interval from two weeks to 12 months in advance, a period dubbed S2S (seasonal to subseasonal). Another new tack is broadening the kinds of phenomena that might be predicted, encompassing extreme weather events such as the heat waves analyzed in the new paper above. The study examines recent progress in using such phenomena as the Madden-Julian Oscillation and the North Atlantic Oscillation as forecasting tools, along with such efforts as the North American Multi-Model Ensemble. “However, an associated U.S. national research agenda aimed at strengthening the contributions of S2S forecasts to public and private activities has not yet emerged,” the report noted.

The study’s vision--that “S2S forecasts will be as widely used a decade from now as weather forecasts are today”--includes 16 recommendations to get us there, as well as four research strategies:

• Engage users in the process of developing S2S forecast products
• Increase S2S forecast skill
• Improve prediction of extreme and disruptive events and consequences of unanticipated forcing events
• Include more components of the Earth system in S2S forecast models

“It is easy to envision the potential value of high-quality predictions two weeks to 12 months ahead for any number of industries--for example, energy, water resource management, and agriculture,” noted committee chair Raymond Ban (Ban and Associates) in the report’s preface. “Even if such information never matches the level of confidence associated with tomorrow’s weather forecast, it could still be used by individuals, businesses, and governments to plan and make a large array of important decisions.”


Figure 5. Severe-weather risk areas for Wednesday (left) and Thursday (right), March 30 and 31, 2016, as designated by NOAA’s Storm Prediction Center on Tuesday morning, March 29.

Tornadoes may spin up across Central/Southern Plains on Wednesday
We’ll be back with a new post by Thursday at the latest. We’re also keeping an eye on a fairly classic set-up for early-spring severe weather in the nation’s midsection, especially from around Kansas City to the Dallas-Fort Worth area. At midday Tuesday, NOAA’s Storm Prediction Center was calling for a slight risk of severe weather on Wednesday over much of the southern and central Great Plains, shifting on Thursday into the central Gulf Coast area. The chance of a major tornado outbreak did not appear large, given the moderate amounts of instability expected and a tendency toward southwest winds at most levels, which would tend to reduce vertical wind shear. Early-morning storms on Wednesday may also cut back on daytime heating. Still, it’s late March, and all of the ingredients should be present for the full gamut of severe weather, including tornadoes in some areas. SPC noted in its Tuesday update that the risk for Wednesday could be upgraded in subsequent outlooks.

Bob Henson



The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 281 - 231

Page: 1 | 2 | 3 | 4 | 5 | 6Blog Index

281. Rbirds
8:31 PM GMT on April 04, 2016
Definition of a generation varies by source. The Census Bureau defines only a single generation - the "babyboomer" generation: 1946-1964. And only that single generation because the Census Bureau believes they share a common set of characteristics. Some social scientists and the media identify other "generations", all of which last a period of 18-22 years. No one defines a generation by the length of the average human lifespan, but rather in segments of around 20 years.

So 140 years would represent around 70 generations rather than 2. I'm not sure that affects the dour conclusion of vis0 but the revised definition means that blink volume by generation decreases significantly.
Member Since: December 31, 1969 Posts: Comments:
280. vis0
8:33 PM GMT on March 31, 2016
  Quoting 277. NativeSun:

      And 140 yrs. is a blink of the eye, in Earths history.



In 140 years that gives us 2 generations, that from childhood - teen years - young adults and adults will (goodness permit) live till lets say 80.

Each of those 2 generations will blink ~730,000,000 (Seven Hundred Thirty million) times and maybe some of the blinking will be purposely slow in the hopes that after they blink that all this havoc is a bad dream that no human could allow this to build to such a level that a child already has 2 strikes against them when they try to take their first breath.


Member Since: December 31, 1969 Posts: Comments:
279. Neapolitan
6:36 PM GMT on March 31, 2016
Quoting 274. 69Viking:



So how does a map that shows a 10' sea level rise show it covering areas of NW Florida that are 50' to 300' above sea level?
It doesn't. Suggest you consult a topographgioc map.
Member Since: December 31, 1969 Posts: Comments:
278. Neapolitan
6:35 PM GMT on March 31, 2016
Quoting 277. NativeSun:

And 140 yrs. is a blink of the eye, in Earths history.

When a person is shot by a high-powered rifle, that single bullet is in contact with their body for only a tiny fraction of a second as it passes through--that is, just "a blink of the eye" in that person's total time on earth. Yet that person is most assuredly dead. Which is to say, your statement has no relevance to or bearing on georgevandenberghe's comment, so please use another response.

Next--
Member Since: December 31, 1969 Posts: Comments:
277. NativeSun
6:25 PM GMT on March 31, 2016
Quoting 238. georgevandenberghe:




I often remind people that six of the past twelve record warm months (Oct 2007, June 2010, July 2011, March 2012, May 2015 and Dec 2015) in Washington DC have occurred in the past nine years. Our period of record is 140 years.

And 140 yrs. is a blink of the eye, in Earths history.
Member Since: December 31, 1969 Posts: Comments:
276. dabirds
6:14 PM GMT on March 31, 2016
Well, guess my post is lost in the ether, so apologies if it all of a sudden appears. Was getting ready to edit it, as downpour let loose at 1 just after I hit post. Anyway, line formed to our E & S instead of moving over us in cells as 10 news forecast showed. Looks like more discreet cells are even farther S & E near Wabash / Ohio confluence. Will need to keep an eye open for more development ahead of front passage, but doubt any severe here in S C IL, but enhanced area def needs to keep an eye out.

Press dropped a tad to 29.42", temp up to 68 (at least b4 downpour, which is over now), says dew pt still 59, though felt stickier. Will be interested to see how much came down in that 8 mins. A few little rumbles from it too, were louder yesterday.
Member Since: December 31, 1969 Posts: Comments:
275. WunderAlertBot (Admin)
6:07 PM GMT on March 31, 2016
JeffMasters has created a new entry.
274. 69Viking
5:59 PM GMT on March 31, 2016
Quoting 263. LargoFl:

with a 10ft sea level rise,kiss most of the gulf and east coast cities goodbye..................


So how does a map that shows a 10' sea level rise show it covering areas of NW Florida that are 50' to 300' above sea level?
Member Since: December 31, 1969 Posts: Comments:
273. dabirds
5:59 PM GMT on March 31, 2016
Well they had initiation timing right, just not cells on top of us. A line forming just to our S & E, more discreet cells appear to be even more S & E near Wabash / Ohio River confluence. Dropped a few more hundreths to 29.42", still says 59 dew pt, but feels stickier as temp now up to 68 in S C IL. Still have to watch for cell forming behind this and ahead of front, but think the action will be mostly in the enhanced area as forecast. Heads up!
Member Since: December 31, 1969 Posts: Comments:
272. 69Viking
5:57 PM GMT on March 31, 2016
Quoting 262. Patrap:

Remove the s from the https and it will post.

IBM did that...and wu cant even fix the wu mail red light icon.

We are fading fast, like real fast.




Thanks!
Member Since: December 31, 1969 Posts: Comments:
271. RitaEvac
5:51 PM GMT on March 31, 2016
Quoting 255. Houdude:

A six foot sea rise would turn the Bayou City of Houston into a bay city, with tides pushing up the bayous. The Ship Channel industries would be inundated regularly, and Galveston would probably be reduced to a string of sand atolls. Pretty hard to imagine.


I think massive changes are coming for America, Oil and Gas is going to be phased out SLOWLY rather we like it or not, and if water levels rise that much, economically it's going to be scary. Unless we phase everything into new industries and people still have jobs. Infrastructure rebuilding is going to be Paramount and to me that's where to invest. I do GIS/mapping and my hope is it will increase into the new industries where infrastructure is key, mapping out everything to the "T"

Geodesign
Member Since: December 31, 1969 Posts: Comments:
270. Qazulight
5:49 PM GMT on March 31, 2016
Quoting 269. RitaEvac:



It'll be the end of the world for man, where cities will be inhabitable, it'll be chaos that Hollywood hasn't even thought up yet.


It will not be that fun. Just depressing. The economics will drive the ruin, not anything interesting like storms or floods are even wars, although they will happen.

On a happier note. A least in South East Texas, when you get to the north side of Houston and up, the terrain becomes more hilly and the water lapping up against that area should make a very beautiful place of the place.

Cheers
Qazulight
Member Since: December 31, 1969 Posts: Comments:
269. RitaEvac
5:39 PM GMT on March 31, 2016
Quoting 258. Qazulight:



It will happen sooner than that.

First, the scientists have been less accurate than room full of dart throwing monkeys. They have dramatically underestimated the speed and scope of the warming and the sea level rise. Additionally, they have been less accurate than the monkeys on how it will effect the weather. The only thing they have gotten right was, yes, the ice is melting and yes the sea level is rising. How much, how fast, how it will effect the weather. All wrong.

What people don't tell you is that long before the sea level becomes a problem, the people will be gone, except for a few homeless people wandering among the ruins. The people who run businesses, understand probability, and they will quit investing long before the sea level rises.

You will see less development of the petro chemical complex. Today the gulf coast is far and away the most efficient complex to turn crude oil and natural gas into useful things. But even that advantage will be overcome as the weather breaks it down.

Expect the Gulf Coast will look a lot like Detroit in 30 years or less, probably less.

Cheers
Qazulight


It'll be the end of the world for man, where cities will be inhabitable, it'll be chaos that Hollywood hasn't even thought up yet.
Member Since: December 31, 1969 Posts: Comments:
268. Gearsts
5:30 PM GMT on March 31, 2016
Quoting 264. tiggerhurricanes2001:

-NAO coming.
@MJVentrice So... what's the most striking feature you see here via the 11-15d period GFS op forecast from 12Z?
Link
GFS being doing that for the last 4 runs. Showing -NAO and then flips to positive NAO on the next -_-
Member Since: December 31, 1969 Posts: Comments:
267. Gearsts
5:21 PM GMT on March 31, 2016
With strong winds.
Member Since: December 31, 1969 Posts: Comments:
266. Patrap
5:20 PM GMT on March 31, 2016
265. LargoFl
5:10 PM GMT on March 31, 2016
WATCH COUNTY NOTIFICATION FOR WATCH 67
NATIONAL WEATHER SERVICE MOBILE AL
1202 PM CDT THU MAR 31 2016

ALC003-025-035-039-053-097-099-129-FLC033-113-311 900-
/O.CON.KMOB.TO.A.0067.000000T0000Z-160331T1900Z/

TORNADO WATCH 67 REMAINS VALID UNTIL 2 PM CDT THIS AFTERNOON FOR
THE FOLLOWING AREAS

IN ALABAMA THIS WATCH INCLUDES 8 COUNTIES

IN SOUTH CENTRAL ALABAMA

CONECUH COVINGTON ESCAMBIA
MONROE

IN SOUTHWEST ALABAMA

BALDWIN CLARKE MOBILE
WASHINGTON

IN FLORIDA THIS WATCH INCLUDES 2 COUNTIES

IN NORTHWEST FLORIDA

ESCAMBIA SANTA ROSA

THIS INCLUDES THE CITIES OF...ANDALUSIA...ATMORE...BAY MINETTE...
BELLVIEW...BRENT...BREWTON...CHATOM...DAPHNE...EN SLEY...
EVERGREEN...FERRY PASS...FLOMATON...GROVE HILL...GULF BREEZE...
GULF SHORES...HOMEWOOD...JACKSON...MILLRY...MILTON...MO BILE...
MONROEVILLE...MYRTLE GROVE...OPP...PACE...PENSACOLA...PRICHARD...
SARALAND...THOMASVILLE AND TILLMANS CORNER.

Member Since: December 31, 1969 Posts: Comments:
264. tiggerhurricanes2001
5:06 PM GMT on March 31, 2016
-NAO coming.
@MJVentrice So... what's the most striking feature you see here via the 11-15d period GFS op forecast from 12Z?
Link
Member Since: December 31, 1969 Posts: Comments:
263. LargoFl
5:04 PM GMT on March 31, 2016
with a 10ft sea level rise,kiss most of the gulf and east coast cities goodbye..................
Member Since: December 31, 1969 Posts: Comments:
262. Patrap
5:01 PM GMT on March 31, 2016
Remove the s from the https and it will post.

IBM did that...and wu cant even fix the wu mail red light icon.

We are fading fast, like real fast.

Member Since: December 31, 1969 Posts: Comments:
261. 69Viking
4:49 PM GMT on March 31, 2016
Can someone post an image of the Alabama radar, I tried but it didn't show up. Not sure what I'm doing wrong.
Member Since: December 31, 1969 Posts: Comments:
260. 69Viking
4:47 PM GMT on March 31, 2016
Alabama is under the gun right, a lot of big storms over a good portion of the state.

Member Since: December 31, 1969 Posts: Comments:
259. LargoFl
4:45 PM GMT on March 31, 2016
Don't forget..most of the Miami metro area is 4 feet or less above sea level,there's going to be a lot, of High rise buildings down there becoming metal islands,till the storms level them.
Member Since: December 31, 1969 Posts: Comments:
258. Qazulight
4:30 PM GMT on March 31, 2016
Quoting 255. Houdude:

A six foot sea rise would turn the Bayou City of Houston into a bay city, with tides pushing up the bayous. The Ship Channel industries would be inundated regularly, and Galveston would probably be reduced to a string of sand atolls. Pretty hard to imagine.


It will happen sooner than that.

First, the scientists have been less accurate than room full of dart throwing monkeys. They have dramatically underestimated the speed and scope of the warming and the sea level rise. Additionally, they have been less accurate than the monkeys on how it will effect the weather. The only thing they have gotten right was, yes, the ice is melting and yes the sea level is rising. How much, how fast, how it will effect the weather. All wrong.

What people don't tell you is that long before the sea level becomes a problem, the people will be gone, except for a few homeless people wandering among the ruins. The people who run businesses, understand probability, and they will quit investing long before the sea level rises.

You will see less development of the petro chemical complex. Today the gulf coast is far and away the most efficient complex to turn crude oil and natural gas into useful things. But even that advantage will be overcome as the weather breaks it down.

Expect the Gulf Coast will look a lot like Detroit in 30 years or less, probably less.

Cheers
Qazulight
Member Since: December 31, 1969 Posts: Comments:
257. LargoFl
4:30 PM GMT on March 31, 2016
STORMS MAY EVOLVE UPSCALE INTO LINE SEGMENTS/CLUSTERS OF
STORMS...SPREADING EWD ACROSS THE TN VALLEY TOWARD/INTO THE SRN
APPALACHIANS THROUGH THE EVENING. CONVECTION/SOME SEVERE RISK MAY
EXPAND AS FAR E AS THE WRN CAROLINAS AND VICINITY OVERNIGHT.

FINALLY...MODELS HINT THAT A WEAK VORT MAX CROSSING THE N CENTRAL
GULF OVERNIGHT MAY SUPPORT AN INCREASE IN CONVECTION NEAR THE MOUTH
OF THE MS RIVER/CENTRAL GULF COASTAL AREAS...WHERE ISOLATED RISK FOR
HAIL/WIND AND POSSIBLY A TORNADO OR TWO MAY EXIST.

..GOSS/COOK.. 03/31/2016
Member Since: December 31, 1969 Posts: Comments:
256. LargoFl
4:20 PM GMT on March 31, 2016
FLSTAE
FLOOD STATEMENT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1045 AM EDT THU MAR 31 2016

...The Flood Warning continues for the following rivers in Florida...

Ochlockonee River near Concord (CR 12) affecting Gadsden and Leon
Counties
Ochlockonee River near Havana (US 27) affecting Gadsden and Leon
Counties

PRECAUTIONARY/PREPAREDNESS ACTIONS...

All persons with interest along the river should monitor the latest
forecasts, and be prepared to take necessary precautions to protect
life and property. Do not drive cars through flooded areas. If you
see flood waters: Turn around. Don`t drown.

For graphical hydrologic information, please go to weather.gov and
click on your state. Select Rivers and Lakes AHPS under current
conditions and click on your river point.

&&

FLC039-073-011445-
/O.EXT.KTAE.FL.W.0028.000000T0000Z-000000T0000Z/
/CONF1.1.ER.160329T0930Z.160331T0400Z.000000T0000Z .NO/
1045 AM EDT THU MAR 31 2016

...Flood Warning extended until further notice...The Flood Warning
continues for
the Ochlockonee River near Concord (CR 12).
* Until further notice.
* At 10:00 AM Thursday the stage was 37.3 feet.
* Minor flooding is occurring and Minor flooding is forecast.
* Flood stage is 36.0 feet.
* Forecast: The river will continue rising to near 37.3 feet by this
afternoon. Additional rises may be possible thereafter.
* Impact: At 38.5 feet: County highway 12 may become closed to
vehicular traffic.

&&

LAT...LON 3069 8432 3064 8433 3058 8439 3056 8436 3068 8422

Member Since: December 31, 1969 Posts: Comments:
255. Houdude
4:11 PM GMT on March 31, 2016
A six foot sea rise would turn the Bayou City of Houston into a bay city, with tides pushing up the bayous. The Ship Channel industries would be inundated regularly, and Galveston would probably be reduced to a string of sand atolls. Pretty hard to imagine.
Member Since: December 31, 1969 Posts: Comments:
254. wpb
4:02 PM GMT on March 31, 2016
https://www.youtube.com/watch?v=5Iz0YrSZ7iA
Member Since: December 31, 1969 Posts: Comments:
253. Walshy
3:45 PM GMT on March 31, 2016
$50 Trillion Global Electricity Network proposed by China

Link
Member Since: December 31, 1969 Posts: Comments:
252. RitaEvac
3:43 PM GMT on March 31, 2016
Ice melt could make seas rise 6 feet by 2100, new study says
Member Since: December 31, 1969 Posts: Comments:
251. Patrap
3:41 PM GMT on March 31, 2016
Area forecast discussion 
National Weather Service New Orleans la
909 am CDT Thursday Mar 31 2016

Previous discussion... /issued 347 am CDT Thursday Mar 31 2016/ 

Synopsis... 

latest surface analysis revealed an exiting 1022mb high over the
Middle Atlantic States and a 995mb low over eastern Iowa. A frontal
zone extended south from the low to eastern Oklahoma to north
central Texas to Texas Big Bend. Tight pressure gradient of 5mb
was present from btr to mob. As a result...southeast to south
winds of 10 to 20 knots with occasional gusts up to 30 knots were
occurring. Isotach analysis showed the nose of 140 knot sub-
tropical jet from Texas Big Bend to west Louisiana...forecast area
in right front quadrant for now. Isotach analysis at 850mb showed
a low level jet of 50 to 60 knots southwest Louisiana to middle Mississippi
Valley...40 knots over our area. 

Precipitable water plots at 00z 
showed a swath of moisture with values of 1.6 to 1.8 inches from
northwest Gulf to west Louisiana to southeastern Arkansas. Finally...the latest upper air analysis the main trough axis from
Iowa to Arizona with disturbances over Missouri/Arkansas and
over Arizona. 18

Short term... 
moisture axis and low level jet will migrate east and yielding 0-3 km
helicity values over 400 to 500 M/S over southwest Mississippi and
Florida parishes of Louisiana this morning before sunrise. Cape
values around 1000 j/kg will increase to 1800 j/kg by sunrise with
a slight lag behind the current convection. Could see some spin
ups through this morning. Ergo...agree with tornados watch through 9
am for north half zones excluding MS coast. Worked over atmosphere may
yield a lull in activity from middle morning to afternoon. Moisture
axis will slide east to the east through the day.
However...surface heating and instability will yield scattered
south to more numerous activity for north zones.

Wind profile becomes southwest from surf to 500mb and slightly
decreasing ll shear this afternoon through Friday. The surface
front will finally approach the north zones late this afternoon
and enter into the forecast area tonight. The focus of the front
and several upper disturbances will yield convection across the
south half of the forecast toward midnight tonight and persisting
through Friday.
Member Since: December 31, 1969 Posts: Comments:
250. Patrap
3:38 PM GMT on March 31, 2016

roll,severe/patrap/wu-icons/beta


Orleans Parish Severe Watches & WarningsNOAA Weather Radio

Watches & WarningsFlash Flood WatchIssued: 3:53 AM CDT Mar. 31, 2016 – National Weather Service

... Flash Flood Watch remains in effect from late tonight through
Friday evening...

The Flash Flood Watch continues for

* portions of southeast Louisiana and Mississippi... including
the following areas... in southeast Louisiana... Assumption...
lower Jefferson... lower Lafourche... Lower Plaquemines... lower
  St. Bernard... lower Terrebonne... Orleans... St. Charles... St. 
James... St. John The Baptist... upper Jefferson... upper
Lafourche... upper Plaquemines... upper St. Bernard and upper
Terrebonne. In Mississippi... Hancock... Harrison and Jackson.

* From tonight through Friday evening

* hourly rainfall amounts of 1 to 2 inches.

* Rainfall amounts of 2 inches in an hour could quickly lead to
localized flash flooding concerns... especially in urban areas
where runoff will be very quick.

Precautionary/preparedness actions...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

You should monitor later forecasts and be prepared to take action
should flash flood warnings be issued.

Member Since: December 31, 1969 Posts: Comments:
249. Patrap
3:35 PM GMT on March 31, 2016


Member Since: December 31, 1969 Posts: Comments:
248. 69Viking
3:21 PM GMT on March 31, 2016
Looks like we're safe along the coast for now, we'll have to wait and see what this afternoon brings.



Member Since: December 31, 1969 Posts: Comments:
247. HurricaneFan
3:17 PM GMT on March 31, 2016
I wonder what the TSR will say next Tuesday. They probably will leave their forecast close to their original one.
Member Since: December 31, 1969 Posts: Comments:
246. 69Viking
3:16 PM GMT on March 31, 2016
Quoting 242. JNFlori30A:

Wow.. over 4" precip. forecast (total) today through Saturday here in the panhandle. My office window faces NW (looking toward Mobile?)

So as I sit here updating clients' WordPress Plugins I find it hard to imagine how such a beautiful spring morning is going to morph into a dark and soggy couple of days.... I think I may have to go for a walk very soon!


Now is definitely the time to do it, by late afternoon I think we'll be dodging storms as there are plenty to our North and West right now!
Member Since: December 31, 1969 Posts: Comments:
245. JRRP7
3:03 PM GMT on March 31, 2016
Quoting 240. wunderkidcayman:


I say we may get La Niña before July ... may even be before June

Eric Blake ‏@EricBlake12
2016 has surprisingly (to me) moved ahead of '98 in a possible #LaNina transition w/much less warm water in the east
Member Since: December 31, 1969 Posts: Comments:
244. georgevandenberghe
2:55 PM GMT on March 31, 2016
Looks like a top 4 or 5   warmest March in DC with likely three or four being ahead   Think we'll beat 53.0 in 1946.. current #4

1981 33.0 43.7 47.6 62.1 66.2 78.7 80.2 77.0 71.0 58.3 51.4 38.5 59.0 38.8 58.6 78.6 60.2 55.2 62.7
2007 40.7 30.9 47.7 53.6 67.8 76.1 79.3 79.7 72.9 67.1 49.8 41.8 59.0 38.6 56.4 78.4 63.3 52.8 65.1
1987 34.7 37.0 47.7 54.8 67.2 76.4 82.6 78.7 72.1 54.4 49.9 41.5 58.1 37.2 56.6 79.2 58.8 53.0 63.2
2002 41.6 42.6 47.7 60.0 65.2 76.1 80.9 81.1 73.0 58.7 47.1 37.2 59.3 43.2 57.6 79.4 59.6 55.5 63.0
1985 30.8 37.8 47.7 61.6 68.1 72.3 79.0 76.7 71.9 61.2 54.3 36.4 58.2 38.1 59.1 76.0 62.5 53.1 63.3
2006 43.1 38.6 47.9 59.5 65.1 74.5 80.4 80.6 67.8 57.3 50.7 44.2 59.1 39.4 57.5 78.5 58.6 54.8 63.5
1948 28.8 36.8 48.0 55.9 64.6 74.0 78.0 75.8 69.4 56.2 51.4 40.2 56.6 34.1 56.2 75.9 59.0 51.4 61.8
1871 32.6 35.9 48.0 58.2 63.9 73.2 74.0 76.8 62.3 58.1 42.3 32.1 54.8 M 56.7 74.7 54.2 52.0 57.6
1918 23.7 36.8 48.4 53.2 69.6 70.8 74.4 77.6 64.2 60.6 46.3 41.6 55.6 29.5 57.1 74.3 57.0 50.4 60.8
1894 37.8 35.2 48.5 53.2 65.9 73.6 77.9 74.0 71.4 57.9 44.0 37.4 56.4 37.1 55.9 75.2 57.8 52.4 60.4
1963 31.4 31.0 48.5 57.8 64.9 73.7 77.6 75.4 66.5 61.2 49.8 31.1 55.7 31.9 57.1 75.6 59.2 51.2 60.3
1997 37.0 44.7 48.7 54.0 62.9 73.1 80.4 77.6 70.5 59.6 46.2 41.0 58.0 41.6 55.2 77.0 58.8 53.4 62.6
1907 37.2 30.2 48.8 48.4 59.2 65.9 75.8 72.4 69.4 52.0 44.5 38.1 53.5 34.8 52.1 71.4 55.3 48.3 58.7
1898 36.6 35.0 48.8 50.9 64.4 73.5 78.8 76.9 71.0 57.8 44.0 35.6 56.1 36.6 54.7 76.4 57.6 51.5 60.7
1983 38.1 38.7 48.8 53.3 64.9 75.0 81.2 81.0 72.6 60.5 50.3 36.0 58.4 40.8 55.7 79.1 61.1 53.1 63.6
2004 30.6 38.2 48.8 57.4 71.8 73.4 78.6 75.9 71.6 58.3 51.0 40.1 58.0 36.0 59.3 76.0 60.3 53.4 62.6
1991 38.6 43.0 48.8 58.2 73.0 76.8 81.4 80.0 71.0 60.4 48.8 42.3 60.2 42.0 60.0 79.4 60.1 56.4 64.0
1913 43.6 36.6 49.0 55.5 64.4 72.8 77.6 74.2 67.4 58.8 47.8 40.4 57.3 40.1 56.3 74.9 58.0 53.7 61.0
2008 40.0 41.0 49.0 58.9 64.7 77.9 80.8 77.9 74.0 58.9 46.6 40.3 59.2 40.9 57.5 78.9 59.8 55.3 63.1
1995 39.6 34.3 49.2 56.3 65.8 74.6 81.5 81.3 70.9 62.3 43.1 35.6 57.9 39.4 57.1 79.1 58.8 53.3 62.5
1974 42.9 39.2 49.2 58.3 65.1 71.5 79.0 78.4 70.2 57.3 50.9 43.1 58.8 41.3 57.5 76.3 59.5 54.4 63.2
1878 33.5 39.8 49.4 58.3 62.5 69.1 80.2 75.0 68.9 57.0 45.4 33.3 56.0 38.4 56.7 74.8 57.1 52.1 60.0
1968 31.4 34.3 49.7 58.0 63.7 74.1 79.9 79.2 72.0 61.3 50.0 36.6 57.5 35.2 57.1 77.7 61.1 51.9 63.2
1938 35.7 40.9 49.8 57.1 63.4 72.8 78.4 78.6 67.4 58.8 49.8 38.4 57.6 37.9 56.8 76.6 58.7 53.3 61.9
1903 33.4 37.4 50.0 54.0 64.4 67.0 76.0 71.8 67.2 56.8 41.6 32.2 54.3 35.1 56.1 71.6 55.2 51.0 57.6
1935 33.3 35.4 50.2 51.9 61.8 73.4 79.4 76.8 67.0 58.2 50.2 32.1 55.8 35.3 54.6 76.5 58.5 51.0 60.6
1990 43.6 45.2 50.2 56.8 64.3 75.0 79.4 76.5 69.6 62.8 52.0 44.5 60.0 38.9 57.1 77.0 61.5 55.9 64.1
1929 34.9 35.0 50.2 57.6 64.5 72.9 76.9 74.4 70.2 55.6 47.6 38.4 56.5 36.4 57.4 74.7 57.8 52.5 60.5
1936 30.6 29.6 50.3 52.2 67.4 72.8 78.4 77.9 71.4 59.7 45.0 39.8 56.3 30.8 56.6 76.4 58.7 50.5 62.0
1973 37.6 37.0 51.1 56.0 62.8 77.1 79.2 79.9 74.3 63.3 51.6 41.9 59.3 39.4 56.6 78.7 63.1 53.6 65.0
1910 33.6 34.6 51.2 57.9 61.4 69.7 77.6 73.8 71.0 60.2 41.4 30.5 55.2 33.3 56.8 73.7 57.5 51.4 59.1
2010 35.3 34.2 51.2 60.9 69.4 80.6 83.1 80.2 75.5 61.6 50.5 34.6 59.8 35.8 60.5 81.3 62.5 55.3 64.3
1976 33.9 46.9 51.3 59.9 65.0 77.6 78.4 76.7 70.4 55.4 43.0 35.5 57.9 40.4 58.7 77.6 56.3 55.8 59.9
1979 35.1 28.4 51.5 56.0 67.7 72.4 78.6 78.5 71.6 58.6 54.4 43.7 58.1 35.5 58.4 76.5 61.5 51.9 64.2
2000 35.9 42.5 51.7 55.6 67.8 74.7 74.7 75.1 67.6 60.2 46.7 31.8 57.0 40.1 58.4 74.8 58.2 54.7 59.4
1977 25.4 38.8 52.7 60.1 69.4 74.3 80.9 78.8 73.9 59.0 51.8 38.1 58.6 33.2 60.7 78.0 61.6 53.5 63.8
1946 36.8 39.2 53.0 56.0 65.2 72.4 76.2 72.6 70.0 61.4 51.8 41.4 58.0 36.3 58.1 73.7 61.1 53.8 62.2


2016 so far 53.2

1921 36.6 39.0 55.5 59.2 62.3 74.2 79.3 72.8 74.4 57.0 47.5 37.9 58.0 38.3 59.0 75.4 59.6 54.5 61.5
1945 30.8 38.4 56.2 59.5 62.8 74.5 76.4 74.8 72.8 57.6 49.3 32.9 57.1 34.5 59.5 75.2 59.9 53.7 60.6
2012 40.8 44.4 56.8 58.3 71.4 76.3 84.0 81.0 72.2 61.0 46.6 45.4 61.5 43.4 62.2 80.4 59.9 58.0 65.0
YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN WINTER SPRING SUMMER AUTUMN 1ST HALF 2ND HALF

Member Since: December 31, 1969 Posts: Comments:
243. dabirds
2:45 PM GMT on March 31, 2016
1.1" in gauge this morning in S C IL, enhanced area just E of me this p.m. StL 10 o'clock precast showed it pop up over us at about 1, then move E and get nastier, we'll see. Pressure continues to drop, 29.45". Was around 30.3 Tues, 29.7 yesterday. Wind gusts still around 30 from S, dew pt at 57 currently. Stay alert S & E!

Looks like it's going to be a chilly opener in Pittsburgh Sun. afternoon. Snow out?

Edit: See I forgot temp - think 59 then, but now 61 & dew pt up to 59, fuel is there & S winds blowing more up into partly sunny area.
Member Since: December 31, 1969 Posts: Comments:
242. JNFlori30A
2:39 PM GMT on March 31, 2016
Wow.. over 4" precip. forecast (total) today through Saturday here in the panhandle. My office window faces NW (looking toward Mobile?)

So as I sit here updating clients' WordPress Plugins I find it hard to imagine how such a beautiful spring morning is going to morph into a dark and soggy couple of days.... I think I may have to go for a walk very soon!
Member Since: December 31, 1969 Posts: Comments:
241. RobertWC
2:34 PM GMT on March 31, 2016
Tracking 'marine heatwaves' since 1950: How the 'blob' stacks up

Date:
March 30, 2016
Source:
University of Washington
Summary:
A tally of Northern Hemisphere marine heatwaves since 1950 shows that prolonged warm periods have recurred regularly in the past, but are being pushed into new territory by climate change.

Link
Member Since: December 31, 1969 Posts: Comments:
240. wunderkidcayman
2:13 PM GMT on March 31, 2016
Quoting 229. rmbjoe1954:

If forecasts bear out and we get La Nina conditions by July we may see an uptick in hurricane formations close to USA waters. I say that on account of extremely warm SST in the area now.

I say we may get La Niña before July ... may even be before June
Member Since: December 31, 1969 Posts: Comments:
239. LargoFl
1:58 PM GMT on March 31, 2016
Member Since: December 31, 1969 Posts: Comments:
238. georgevandenberghe
1:54 PM GMT on March 31, 2016
Quoting 151. vis0:


Agree, though  if not immediately sooner than most think (most as in the general uninformed or misinformed public) PLUS IMHO you forget the "s" after disaster.

For those that say or think this has happened before. Notice already in the past few years the USofA has broken 3-5 weather extremes and when one notices the records that where broken none are over a year or even 5 year period (except the dust bowl).
Read wxu members as barbamz, plazared, pablosyn (Pablosyn still here??? after barbamz report of a serious storm in pablosyn's area) reports/links for similar examples throughout the world.  

These are records that are spread over 20-40 years being broken in a span of ~5-10 years. Remember part of the reason for the spread of the dust bowl was crop mismanagement when now we know better management so if we see half a dust bowl THAT means that with the better management of crops/soil something still has influenced nature to create such an extreme.  

That something might start with an "a" and Ends with a "W", gee i wonder if readers can guess the missing letter? ...Taz don't even think of posting that.

BACK TO OBSERVING what could become serious weather. Remember do not drive through water where you cannot see the asphalt, don't think because the road has been there for your entire life, that its still there when its covered by water. If the road has been washed away or crumbling it then becomes a fools road, and i'm sure you are not a fool so be safe turn around and warn others.



I often remind people that six of the past twelve record warm months (Oct 2007, June 2010, July 2011, March 2012, May 2015 and Dec 2015) in Washington DC have occurred in the past nine years. Our period of record is 140 years.
Member Since: December 31, 1969 Posts: Comments:
237. LargoFl
1:54 PM GMT on March 31, 2016
Greenland ice sheet today........................................Link
Member Since: December 31, 1969 Posts: Comments:
236. LargoFl
1:48 PM GMT on March 31, 2016
Member Since: December 31, 1969 Posts: Comments:
235. RobertWC
1:40 PM GMT on March 31, 2016
Scientists say Antarctic melting could double sea level rise. Here’s what that looks like.

Instead, this study published in the journal Nature suggests that we should actually double that forecast when we include melting in Antarctica: approximately six feet of sea level rise by 2100. Just as alarming is the projection that Antarctica by itself could add 50 feet of sea level rise by 2500.

What does that even look like?


Link
Member Since: December 31, 1969 Posts: Comments:
234. Gearsts
1:23 PM GMT on March 31, 2016
Quoting 233. Tropicsweatherpr:

No change to the drought areas from last week in Puerto Rico.


Dry month.
Member Since: December 31, 1969 Posts: Comments:
233. Tropicsweatherpr
12:57 PM GMT on March 31, 2016
No change to the drought areas from last week in Puerto Rico.

Member Since: December 31, 1969 Posts: Comments:
232. Xyrus2000
12:41 PM GMT on March 31, 2016
Quoting 223. gr8lakebreeze:



Yeah light pollution is a major concern for me too. I live about 80 miles North of Cleveland and 90 or so N/E of Detroit and about 30 S/W of London Ontario and while my overhead view is still able to show the milky way, it is washed out about 35 degrees down from the zenith. The light pollution is still limited to domes of light on the horizon, the light signature of London is by far the worst comprising, most of my N/E view.

I bought a Skyshed pod and placed it on a deck behind my barn, well away from the lights from the busy rural highway in front of my place.

As for scopes, I am limited to a 9.25" Celestron and a small refractor plus binos, of course. I sold my 5 inch APO refractor a couple of years back, as it's a tight fit in the pod, besides the C 9.25 is a pretty awesome scope, it does double duty as a deep sky scope plus it is a wonderful planetary instrument as well.





The 9.25" Clestron's are pretty popular. Big enough to be serious, yet still small enough that most people won't blow their backs out moving it around.

Where I am, the light pollution is bad enough that I can almost read outside at night. :P
Member Since: December 31, 1969 Posts: Comments:
231. LindyVirginIslander
12:12 PM GMT on March 31, 2016
Hi there!

It's a pleasant 81, feeling like 84, and partly cloudy kind of morning on the island today. Looks like an afternoon of showers on their way.

Had a wonderful 5-day camping trip which went way too quickly and am already planning our next get away!

Latest update on Zika:

"Weekly Update: No New Zika Cases, Four More Cases of Dengue

The Virgin Islands Department of Health reported no new cases of Zika this week, though it did confirm four case of dengue.
The total count for Zika cases remains at 12, with 11 on St. Croix and one on St. Thomas. The new dengue cases were reported on St. Croix and St. Thomas."

Hope all is well with everybody!

Lindy


Member Since: December 31, 1969 Posts: Comments:

Viewing: 281 - 231

Page: 1 | 2 | 3 | 4 | 5 | 6Blog Index

Top of Page

Category 6™

About

Cat 6 lead authors: WU cofounder Dr. Jeff Masters (right), who flew w/NOAA Hurricane Hunters 1986-1990, & WU meteorologist Bob Henson, @bhensonweather