Global model runs discussion

[HURAKAN]

SST in the area are below 22C, not good for tropical or subtropical development

[cycloneye]

Dr Jeff Masters says those waters can support a subtropical system:

First named storm in the Atlantic possible next week

Both the GFS and ECMWF models are predicting that an extratropical "cut-off" low will separate from the jet stream early next week several hundred miles east of Bermuda, and linger for several days over subtropical waters with temperatures in the 22 - 24°C range. These ocean temperatures may be warm enough to allow the storm to organize into a named subtropical storm. However, climatology argues against such an occurrence; there has been only one named April storm in the Atlantic since 1851. If a subtropical storm does form next week, it would probably not affect any land areas.

[RL3AO]

I think we should take any storm we can get in the Atlantic because when El Nino kicks in this fall the ATL will hit a brick wall.

[cycloneye]

I think we should take any storm we can get in the Atlantic because when El Nino kicks in this fall the ATL will hit a brick wall.

That is true.

There is now a thread for that possible low in the Atlantic,so we can post the model runs there.

viewtopic.php?f=31&t=112663&p=2219028#p2219028

[xironman]

I saw in today's HPC discussion that they are running the GFS parallel, but I don't know how to get to it in the new NCEP page. Does anyone here know?

Code: Select all

THE UKMET/GFS PARALLEL WERE THE FIRST TO
ADVERTISE THE GULF COAST CYCLONE ON THEIR 16/00Z RUNS...WITH THE
ECMWF AND OPERATIONAL GFS CONVERGING UPON THE SLOWER SOLUTIONS
DURING THEIR PAST DAY OF RUNS.  THE 00Z CANADIAN IS MUCH MORE
NORTHERLY AND NORTHERN STREAM-DOMINANT WITH ITS CYCLONE WITHIN THE
EAST COAST TROUGH.  DUE TO THE AMPLIFICATION EXPECTED...THE
CANADIAN IS LIKELY TOO FAR NORTH WITH THIS FEATURE...SO IT WAS NOT
USED.  THE 00Z GFS IS THE SLOWEST OF THE GUIDANCE WITH THE
PROGRESSION OF THE GULF COAST LOW...BUT THAT HAS BEEN THE TREND SO
FAR IN THE GFS/ECMWF GUIDANCE SO DID NOT WANT TO DISMISS IT.  THE
00Z GFS PARALLEL WAS BY FAR THE DEEPEST OF THE GUIDANCE...TAKING A
984 HPA LOW THROUGH NEW ENGLAND MONDAY NIGHT.  THE PRESSURES WERE
DERIVED FROM A 40/30/30 BLEND OF THE 00Z UKMET/00Z GFS
PARALLEL/00Z ECMWF SOLUTION FROM FRIDAY THROUGH SUNDAY BEFORE
SWITCHING TO A 40/30/30 BLEND OF THE 00Z GFS PARALLEL/00Z GFS/00Z
ECMWF THEREAFTER.  THE 12Z GLOBAL ENSEMBLE GUIDANCE INDICATES THAT
IT IS UNLIKELY THE DETERMINISTIC GUIDANCE WILL SLOW THIS SYSTEM
DOWN TOO MUCH MORE THAN IS CURRENTLY SHOWN BY THE GFS/ECMWF/UKMET
SOLUTIONS.

[cycloneye]

Searching the net,I found this site of GFS parallel,but I dont know this is what you are looking for.

http://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/para/

[Dean4Storms]

I didn't see this mentioned anywhere. Might need to watch this...........

http://raleighwx.americanwx.com/models/ ... p06132.gif

[Dean4Storms]

Question will be does it become tropical or sub-tropical?

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... =Animation

[cycloneye]

Hi Dean. I merged the thread that you made to this models thread as we dont want Talking Tropics forum to be full of threads of individual runs.

[Dean4Storms]

Hi Dean. I merged the thread that you made to this models thread as we dont want Talking Tropics forum to be full of threads of individual runs.

Gotcha, although this isn't an individual run, 18z, 00z and 06z all show this and ECMWF is also trending that way.

From NWS New Orleans AFD this morning

UNFORTUNATELY...THE MODELS HAVE SHIFTED DRAMATICALLY IN THE LAST
COUPLE OF RUNS ON THE EVOLUTION OF A STRONG LONG WAVE TROUGH
DIVING INTO THE EASTERN THIRD OF THE NATION FOR THE UPCOMING
WEEKEND. BOTH THE ECMWF AND THE GFS DEPICT A SURGE OF UPPER LEVEL
ENERGY DIVING SOUTH ACROSS THE LOWER MISSISSIPPI VALLEY AND
BEGINNING TO CUT OFF OVER NORTHWEST GULF OF MEXICO ON FRIDAY. THIS
SOLUTION IS MUCH SLOWER IN PROGRESSION THAN THE PREVIOUS RUNS
INDICATED. WITH A CUT OFF LOW SLOWLY TRANSITING THROUGH THE
NORTHERN GULF OF MEXICO OVER THE WEEKEND...AN EXTENDED PERIOD OF
UNSETTLED WEATHER IS NOW IN THE FORECAST. GIVEN THE RADICAL SHIFT
AND LOWER FORECAST CONFIDENCE...HAVE ONLY WENT WITH CHANCE POPS
FOR THE WEEKEND SYSTEM AT THIS TIME. IF THE NEXT FEW MODELS RUNS
BECOME MORE CONSISTENT WITH THIS CUT-OFF FEATURE...WILL HAVE TO
BUMP UP POPS FOR THE WEEKEND. HAVE INCREASED SKY COVER...POPS...AND
LOWERED DAYTIME TEMPERATURES INTO THE LOWER TO MIDDLE 70S F0R BOTH
SATURDAY AND SUNDAY. THE CUT-OFF LOW AND ASSOCIATED RAIN CHANCES
WILL FINALLY PULL EAST OF THE REGION BY MONDAY MORNING.

MARINE...GRADIENT WILL CONTINUE TO RELAX OVER THE ERN HALF OF THE
COASTAL WATERS THROUGH TODAY BUT WEST OF THE MS RIVER DELTA THE
GRADIENT WILL TIGHTEN BACK UP BY MIDDAY/AFTN. THIS WILL BE A RESULT
OF BROAD LOW PRESSURE OVER THE ERN GULF AND HIGH PRESSURE BUILDING
SOUTH INTO ERN TX AND THE TX COAST. WINDS WILL LIKELY RANGE IN THE
15-20 KT RANGE WEST OF THE RIVER THIS AFTN AND COULD PERSIST THROUGH
TONIGHT SO WE WILL ADD SCS HEADLINES. THE GRADIENT WILL WEAKEN
CONSIDERABLY BY TOMORROW AS HIGH PRESSURE TAKES OVER THROUGH THE
REMAINDER OF THE WORK WEEK. BY SAT MORNING THE FCST HAS CHANGED
SIGNIFICANTLY. MDLS ARE NOW IN GREAT AGREEMENT AND HAVE COME AROUND
TO A STRONG GULF LOW DEVELOPING RIGHT OVER THE REGION INSTEAD OF
JUST A COLD FRONT MOVING THROUGH. THIS WILL LEAD TO SCY CONDITIONS
AT THE LEAST AND COULD BRING BORDERLINE GALE WARNING CONDITIONS BY
SAT EVN AND INTO SUN. WITH THIS NEW SOLUTION WE HAVE RAMPED UP WINDS
AND SEAS CONSIDERABLY FOR SAT-MON. IF THE MDLS HOLD ONTO THIS
SOLUTION THEN WE WILL LIKELY NEED TO ISSUE A GALE WATCH BY FRIDAY.

[Pearl River]

From New Orleans this afternoon:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
340 PM CDT TUE APR 17 2012

LONG TERM...
NEXT SYSTEM WILL BEGIN TO TAKE SHAPE THURSDAY AS A RIGOROUS UPPER
TROUGH BEGINS TO DIVE SOUTHEASTWARD INTO THE SOUTHWEST CONUS.
MODELS CONTINUE TO BE IN GOOD AGREEMENT CONCERNING THIS SYSTEM
AND BOTH THE GFS AND ECMWF ARE STILL INDICATING THAT A CLOSED LOW
WILL DEVELOP INT HE BASE OF THE TROUGH AS IT APPROACHES THE
LOUISIANA/TEXAS BORDER FRIDAY NIGHT. THIS WILL HAVE A TWO FOLD
IMPACT ON THE SURFACE SYSTEM. IT WILL SLOW THE EASTWARD
PROGRESSION OF THE SYSTEM...AND WILL RESULT IN A WELL DEVELOPED
SURFACE LOW AS IT MOVES THROUGH THE LOCAL AREA.

CONCERNING THE SLOW MOVEMENT OF THE SYSTEM...WILL CONTINUE TO
CARRY CHANCE POPS FRIDAY NIGHT THROUGH SUNDAY...THOUGH THESE POPS
WILL LIKELY NEED TO BE TWEAKED UPWARD FRIDAY NIGHT OR SATURDAY AS
CONFIDENCE IN THE TIMING INCREASES. THE SLOW MOVING NATURE OF THE
SYSTEM WILL ALSO RESULT IN A THREAT OF LOCALIZED HEAVY RAINFALL.
EXPECT PW VALUES TO RISE ABOVE 1 INCH BY FRIDAY NIGHT AS STRONG
SOUTHEAST WINDS AHEAD OF THE SYSTEM CONTINUE TO PUMP GULF MOISTURE
INTO THE AREA. MAX PW THROUGH THE PERIOD WILL BE NEAR OR SLIGHTLY
ABOVE 1.5 INCHES...OR ROUGHLY 150 PERCENT OF NORMAL FOR THIS TIME
OF YEAR. AMPLE MOISTURE THROUGHOUT THE COLUMN WILL RESULT IN
STORMS THAT ARE EFFICIENT RAIN PRODUCERS. IT IS STILL TOO SOON TO
DETERMINE WHICH AREAS WILL BE MOST AT RISK FOR LOCALLY HEAVY
RAINFALL...BUT DETAILS SUCH AS THIS WILL CONTINUE TO BE REFINED
OVER THE NEXT SEVERAL DAYS.

ADDITIONALLY...STRONG GRADIENT WINDS ARE EXPECTED AS THE LOW AND
FRONT PASS THROUGH THE AREA. THESE STRONG WINDS...COMBINED WITH
THE HIGHER CHANCE OF RAIN...COULD HAVE SIGNIFICANT IMPACTS ON
PLANNED OUTDOOR ACTIVITIES THIS WEEKEND.

THE SEVERE WEATHER SET UP DOES NOT LOOK AS FAVORABLE WITH THIS
SYSTEM AS THE HEAVY RAIN MODE. BY THE TIME THE DYNAMICAL FORCING OF
THE FRONT APPROACHES AND ENTERS THE REGION...THE INSTABILITY IS
FORECAST TO BE LARGELY DIMINISHED.

.MARINE...
COLD FRONT WILL MOVE SLOWLY THROUGH THE COASTAL WATERS THIS
EVENING AND THROUGH THE FIRST PART OF TONIGHT. AS THE FRONT PASSES
THROUGH...THE GRADIENT WILL CONTINUE TO WEAKEN AND WINDS AND SEAS
WILL RESPOND ACCORDINGLY. MODELS CONTINUE TO BE IN GOOD AGREEMENT
CONCERNING THE DEVELOPMENT OF A SURFACE LOW OVER THE NORTHERN GULF
COAST REGION LATE FRIDAY/SATURDAY. THIS WILL LEAD TO STRONG
GRADIENT WINDS OVER THE REGION AND LIKELY ADVISORY CONDITIONS BY
SATURDAY MORNING. AS THE LOW CONTINUES TO DEEPEN AND THE PRESSURE
GRADIENT TIGHTENS...SUSTAINED WINDS COULD REACH AS HIGH AS 25 TO
30 KTS WITH FREQUENT GUSTS TO NEAR GALE FORCE. WILL CONTINUE TO
MONITOR FUTURE MODEL RUNS AND TWEAK WIND SPEEDS WHERE
NECESSARY...BUT IT IS NOT ENTIRELY OUT OF THE QUESTION FOR A GALE
WATCH/WARNING TO BE NECESSARY FOR PART OF THE WEEKEND. STRONG WINDS
AND HAZARDOUS SEAS CONTINUE TO BE AN ISSUE DURING THE FIRST PART
OF NEXT WEEK AS STRONG HIGH PRESSURE BUILDS INTO THE AREA.

[somethingfunny]

If this wasn't mid April I'd say it looks like a classic Dixie snow setup.

[cycloneye]

Hey peeps,maybe we get something Sub or Tropical briefly from this low in NGOM in 96 hours?

4/18/12: 12z GFS



Uploaded with imageshack.us

[cycloneye]

Normally,is a favored area for early activity, but will the SW or Western Caribbean be the area where the first named storm is born on the 2012 North Atlantic Hurricane Season?

4/18/12: 12z GFS at 240 hours



Uploaded with imageshack.us

[cycloneye]

NCEP GFS will be upgraded on May 22

Let's see if this model takes away the crown from ECMWF as the #1 Global Model.

Effective on or about Tuesday, May 22, 2012, beginning with the 1200 Coordinated Universal Time (UTC) run, the National Centers for Environmental Prediction (NCEP) will upgrade the GFS model and its associated data assimilation system (GDAS). The primary changes will be to the analysis system. There will be no major changes to the GFS model itself, but there will be a few modifications to the output products available from the GFS.

The major component of the analysis change will be the incorporating a hybrid variational/ensemble assimilation system. In this system, the background error used to project the information in the observations into the analysis is created by a combination of a static background error (as in the prior system) and a new background error produced from a lower resolution (T254) Ensemble Kalman Filter. The development of this system was done in collaboration with PSD at ESRL. Including this change and the other smaller changes listed below produce significant positive impact on forecasts in both the northern and southern hemispheres and in the tropics. In almost all measures, a positive impact is noted; however, during the summer (convective precipitation) season, a small consistent degradation of the rain/no rain line and an increase in the bias was noted. This problem will be addressed through modifications to the convective parameterization in the next global implementation.



Additional changes in this upgrade include:

Analysis Changes:

- Use GPS RO bending angle rather than refractivity

- Include compressibility factors for atmosphere

- Retune SBUV ob errors, fix bug at top

- Update radiance usage flags

- Prepare for monitoring NPP and Metop-B satellite data

- Add NPP ATMS satellite data

- Add GOES-13/15 radiance data

- Add SEVERI CSBT radiance product

- Include satellite monitoring statistics code in operations

- Add new satellite wind data and quality control

- Update to current version of analysis trunk for optimization

and preparation for future updates


http://www.nws.noaa.gov/os/notification ... hybrid.htm

[hurricanetrack]

That's awesome that they're fixing this:

Retune SBUV ob errors, fix bug at top

That always bothered me, LOL.

Good to know this Luis. Now we'll see if it can whip up on the ole Euro.

[somethingfunny]

Normally,is a favored area for early activity, but will the SW or Western Caribbean be the area where the first named storm is born on the 2012 North Atlantic Hurricane Season?

4/18/12: 12z GFS at 240 hours

[ img]http://img827.imageshack.us/img827/2061/gfsatlantic24010mwndpre.gif[/img]

Uploaded with imageshack.us

If this festers for a while, it could become a named storm. It would be Aletta though, not Alberto.

[NDG]

Perhaps some early action in the Caribbean in May. Though I am not a long range forecast fan, the GFS has been fairly persistent in its long range of a an organized system developing down there towards the end of its run, but with its history of coming out with this solution about this time of the yeay, year after year I am not really jumping on it just yet

http://mag.ncep.noaa.gov/NCOMAGWEB/appc ... mageSize=M

This is the current disturbance that will give some wet weather from Cuba to the Bahamas to possibly S FL over the next few days.

[cycloneye]

Perhaps some early action in the Caribbean in May. Though I am not a long range forecast fan, the GFS has been fairly persistent in its long range of a an organized system developing down there towards the end of its run, but with its history of coming out with this solution about this time of the yeay, year after year I am not really jumping on it just yet

http://mag.ncep.noaa.gov/NCOMAGWEB/appc ... mageSize=M

This is the current disturbance that will give some wet weather from Cuba to the Bahamas to possibly S FL over the next few days.

http://i20.photobucket.com/albums/b245/ ... PkDrBT.jpg

I prefer to see other models join GFS on that scenario and if it happens,then I jump on the development bandwagon.

[CYCLONE MIKE]

First post of the 2012 season anyway saw this afternoon on our long range forecast from msy/btr office they are saying models are showing an inverted trough moving north out of the gulf mid to late next week. Wonder if this is the system to cause that?