September: Weekend Rain Chances. 1-2 Inches Possible C/N TX

[Paul Robison]

Thank you, Jeff. For now, I'll trust the GFS. Anyone with me on that?

[jeff]

Thank you, Jeff. For now, I'll trust the GFS. Anyone with me on that?

I would not recommend putting all your eggs in one basket or all your support behind one model. In forecasting a consensus is the best course of action and sometimes even that is not correct for the final outcome. With that said there is decent model agreement on development in the BOC and a track generally toward MX...only the FIM and a few ensemble members show a threat up the coast toward TX.

Finally time for the Texans to play....the weather will still be here in the morning!

[Katdaddy]

2AM TWO on the Caribbean disturbance:

AN AREA OF DISTURBED WEATHER LOCATED OVER THE NORTHWESTERN CARIBBEAN
SEA IS MOVING WESTWARD AT ABOUT 10 MPH. THIS DISTURBANCE IS
FORECAST TO MOVE ACROSS THE YUCATAN PENINSULA AND INTO THE BAY OF
CAMPECHE BY LATE THURSDAY WHERE AN AREA OF LOW PRESSURE IS EXPECTED
TO FORM. ENVIRONMENTAL CONDITIONS SHOULD GRADUALLY BECOME MORE
CONDUCIVE FOR THE DEVELOPMENT OF A TROPICAL DEPRESSION BY THE
WEEKEND. THIS SYSTEM HAS A LOW CHANCE...10 PERCENT...OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A HIGH CHANCE...60
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS.

[srainhoutx]

The overnight guidance continues to advertise a broad and rather large surface circulation entering the Bay of Campeche from the NW Caribbean on Thursday and heading generally WNW to NW. Due to the large circulation and long fetched ESE winds streching from the SE Gulf and NW Caribbean Sea and increasing swells and fresh breezes, Coastal Counties from Brownsville to Morgan City Louisiana need to keep a close eye on the developments and the potential for a Coastal Flood Watch with increasing tides and winds by late Saturday into Monday. Interests from Tuxpan Mexico to Vermilion Bay Louisiana should monitor future forecasts closely and expect changes over the next several days.This is a rather complex and complicated forecast and changes are likely as we head into the late week/weekend time frame across the NE Mexico Gulf Coast extending NE along the Texas and SW Louisiana Gulf Coastal areas.

[srainhoutx]

Morning e-mail from Jeff:

Tropical wave over the western Caribbean Sea will move into the southern Gulf of Mexico and likely develop into a tropical cyclone late this week or this weekend.

Focus for the next several days will be on the current tropical wave in the western Caribbean Sea and its potential for development and impacts along the TX coast. Current satellite images show a cluster of showers and thunderstorms over the western Caribbean Sea in association with what appears to be the southern end of the tropical wave that spawned TS Gabrielle last week. This wave is moving toward the WNW and should progress into the Yucatan before being able to develop.

Global forecast models suggest this wave will enter the southern Gulf of Mexico late this week in the Thursday-Friday time period and all show development of surface low pressure. The Bay of Campeche has been a favored area for development this year and tropical systems in this region under favorable upper level conditions have a tendency to spin up quickly. While most of the global models want to track the system into MX much like several other tropical storms have done this year in the southern Gulf, there are some trends that suggest a westward track is not a 100% done deal.

Upper level steering high pressure currently anchored over the central plains will be drifting southward over the next few days and by late this week be located over TX into the SE US. This pattern would block any potential northward turn of a Bay of Campeche tropical system and send the system on a W to WNW into MX. However over the weekend into early next week, this high begins to break down and shift into the SE US under the approach of a W US trough. This trough erodes the western edge of the ridge protection over TX and does open a path for a tropical system to turn NW or NNW toward the NW Gulf coast. At the moment this is the least likely of the two options…but it is a possibility and while it was only supported by a few model ensemble members yesterday, the 06Z GFS run is concerning for coastal TX…with a system tracking NNW toward the CRP area.

Upper air conditions look overly favorable for development and there appears to be a good shot at this system becoming a hurricane depending on how long it remains over the water.

The National Hurricane Center indicates a 60% chance…a high chance….of development of a tropical cyclone over the next 5 days and a 10% chance over the next 48 hours.

Impacts:

A long fetch ESE to E will be building seas across the Gulf over the next several days. This fetch will result in the formation of long period swells and tidal pile-up along the TX coast. This process is already underway with current coastal tidal sites averaging .5 to 1.0 ft above normal predicted levels. Using the ET-surge modeling with wind grids from the GFS model shows a developing coastal storm surge of around .5 of a foot toward the end of the week and total coastal water levels rising to around 1.0-2.5 ft. These levels would not cause any significant coastal flooding issues, but large swells will be breaking well up the beach and possibly at the base of dunes resulting in some potential for beach erosion and strong rip currents.

Tides and seas would require additional increases if any southern Gulf tropical cyclone moved further northward or the pressure gradient increased between the tropical system and high pressure to our NE.

Stay tuned!

[srainhoutx]

Possible RECON tasking has been issued for the Bay of Campeche disturbance:

Code: Select all

WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1045 AM EDT TUE 10 SEPTEMBER 2013
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
         VALID 11/1100Z TO 12/1100Z SEPTEMBER 2013
         TCPOD NUMBER.....13-101

I.  ATLANTIC REQUIREMENTS
    1. NEGATIVE RECONNAISSANCE REQUIREMENTS    
    2. SUCCEEDING DAY OUTLOOK: POSSIBLE LOW LEVEL INVEST 
       IN THE GULF OF MEXICO NEAR 20N 92W AT 12/1800Z.          
    3. REMARKS: POSSIBLE GLOBAL HAWK MISSION FOR 12/1100Z

[srainhoutx]

INVEST 93L has been designated for the NW Caribbean tropical disturbance.

[Portastorm]

Looks like we have some long days and nights (finally) ahead of us in tracking 93L's development and future direction. I know most of us would welcome a rainy system into Texas with open arms ... of course without the damaging wind part.

[spadilly]

I would love some rain this weekend to help keep temps down for Alabama @ A&M. It's been entirely too hot out there the last two weekends!

[Ptarmigan]

Looks like we have some long days and nights (finally) ahead of us in tracking 93L's development and future direction. I know most of us would welcome a rainy system into Texas with open arms ... of course without the damaging wind part.

It would be nice to see rain.

[srainhoutx]

The 12Z GFS has a weak broad circulation center nearing the Brownsville area late on Sunday into Monday.

[srainhoutx]

The 12Z GFS suggests near 10 inches of rainfall across drought parched Regions of Texas.

[srainhoutx]

The 12Z GFS ensembles members are trending a bit further N and slightly stronger with 93L as it heads generally WNW to NW towards the NE Mexico/Lower Texas Coast.

[srainhoutx]

The SHIPS (Statistical Hurricane Intensity Prediction Scheme) guidance suggests we may see a Hurricane near the S Texas Coast:

TROPICAL CYCLONE GUIDANCE MESSAGE
NWS NATIONAL HURRICANE CENTER MIAMI FL
1830 UTC TUE SEP 10 2013

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

DISTURBANCE INVEST (AL932013) 20130910 1800 UTC

...00 HRS... ...12 HRS... ...24 HRS... ...36 HRS...
130910 1800 130911 0600 130911 1800 130912 0600

LAT LON LAT LON LAT LON LAT LON
BAMS 18.0N 86.1W 18.6N 87.9W 19.4N 89.9W 19.7N 91.8W
BAMD 18.0N 86.1W 18.4N 87.5W 19.0N 89.0W 19.6N 90.5W
BAMM 18.0N 86.1W 18.5N 87.7W 19.2N 89.5W 19.6N 91.2W
LBAR 18.0N 86.1W 18.3N 87.3W 19.2N 89.0W 20.3N 90.8W
SHIP 20KTS 27KTS 35KTS 43KTS
DSHP 20KTS 24KTS 26KTS 32KTS

...48 HRS... ...72 HRS... ...96 HRS... ..120 HRS...
130912 1800 130913 1800 130914 1800 130915 1800

LAT LON LAT LON LAT LON LAT LON
BAMS 20.0N 93.6W 19.6N 96.6W 19.2N 99.2W 19.1N 101.0W
BAMD 20.1N 91.9W 20.8N 94.2W 21.6N 96.8W 22.6N 99.6W
BAMM 20.0N 93.0W 20.2N 95.8W 20.1N 98.5W 20.3N 100.5W
LBAR 21.5N 92.3W 23.8N 94.8W 25.8N 96.1W 28.1N 96.7W
SHIP 52KTS 63KTS 67KTS 71KTS
DSHP 41KTS 52KTS 32KTS 27KTS

...INITIAL CONDITIONS...
LATCUR = 18.0N LONCUR = 86.1W DIRCUR = 275DEG SPDCUR = 4KT
LATM12 = 18.0N LONM12 = 85.3W DIRM12 = 276DEG SPDM12 = 5KT
LATM24 = 17.7N LONM24 = 84.2W
WNDCUR = 20KT RMAXWD = 50NM WNDM12 = 20KT
CENPRS = 1009MB OUTPRS = 1010MB OUTRAD = 100NM SDEPTH = S
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

[srainhoutx]

The Experimental 12Z FIM 9 Model 10 meter wind fields suggest a large sprawling circulation near the Lower Texas Coast on Monday.

[Katdaddy]

Invest 93L looking better organized and a rather large system that will likely become TS Ingrid in the GOM this weekend. Models are showing shift further N will a possible landfall between Tampico, MX and Brownsville, TX. A few models are further N toward the Corpus Christi area. Still many days out and not even in the GOM yet however very well needed tropical rains may become reality for a large part of TX early next week. Interesting days ahead.

[Ptarmigan]

Mexico to Louisiana should keep an eye on 93L.

Looks like a weak circulation is developing.

[Ptarmigan]

Invest 93L could be like Frances, a large slow moving storm that produces heavy rain over a large area.

[TexasBreeze]

The 18z new gfs is 8+ inches (!!!) of widespread rainfall over a large area.

[rnmm]

8+ inches of rain?!?!?!? What a beautiful thought and sight!!