Florida joins the Severe Weather Threat Tuesday

[Rainband]

000
FXUS62 KTBW 260649
AFDTBW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
249 AM EDT TUE APR 26 2005

...SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING AND TONIGHT...

.SHORT TERM (TODAY-THU)...A SUB-TROPICAL JET FROM MEXICO TO THE
SOUTHEAST U.S. WILL SHIFT SOUTHWARD/ TO THE GULF AND FL/ AS A
COMPLEX AND SPRAWLING LOW PRESSURE SYSTEM OVER THE GREAT LAKES
ROTATES THROUGH THE NORTHEAST QUARTER OF THE NATION WITH A LONG
WAVE TROUGH SWINGING INTO THE SE BY WED. THE JET DROPPING SOUTH
ALONG WITH A SERIES OF SHORT WAVE TROUGHS MOVING FROM THE SOUTHERN
PLAINS AND THROUGH THE BASE OF THE TROUGH IS EXPECTED TO SUPPORT
CONSIDERABLE PCPN ALONG WITH STRONG THUNDERSTORMS. THERE IS A SLIGHT
RISK THAT SOME OF THESE STORMS MAY BECOME SEVERE AS THEY MOVE INTO
AND ACROSS THE CWFA LATE THIS AFTERNOON AND THROUGH THE NIGHT...AS
A COLD FRONT/ ALIGNED WITH THE UPPER TROUGH/ MOVES ACROSS THE GULF
AND OVER THE STATE WED.

SCATTERED TO ISOLATED TSTMS THIS AFTERNOON WILL BECOME NUMEROUS
DURING THE NIGHT ALONG THE POSSIBILITY OF SOME OF THEM REACHING
SEVERE LIMITS. TSTMS AND PCPN WILL BE ENDING...FROM NORTH TO SOUTH...
AS THE FRONT CROSSES THE AREA WED.

SURFACE HIGH PRESSURE BUILDS IN OVER THE GULF DURING WED AND THEN
SLIDES EAST...ACROSS THE SE STATES INCLUDING FL...THU. THIS WILL HELP
TO COOL TEMPERATURES/ THAT WILL HAVE WARMED SLIGHTLY TODAY AND WED/
BUT ONLY TO JUST BELOW CLIMO.

.LONG TERM (THURS NIGHT - MON)...LITTLE CHANGE TO GLOBAL MODELS...AND
HENCE CURRENT FCST THINKING...THROUGH EARLY SUNDAY AS FLAT 500 MB
RIDGE ON SCHEDULE TO STRETCH ACROSS THE PENINSULA WHILE SFC HIGH
EXTENDS FROM BERMUDA TO THE CENTRAL PENINSULA. TEMPS CURRENTLY
ADVERTISES AT OR SLIGHTLY ABOVE SEASONAL NORMS REMAIN.

AS FOR SUNDAY/MONDAY...SEVERAL OF THE 00Z RUNS ARE IN AGREEMENT THAT
WE MAY NOT BE JUST DONE YET WITH TROUGH PASSAGES. THE GFS NOW HAS
YET ANOTHER TIGHT IMPULSE RACING THROUGH N FLORIDA AND THE NORTH
HALF OF THE PENINSULA SUNDAY EVENING...WITH QUICKLY DEPARTING
ENERGY EARLY MONDAY. THE NOGAPS AND CANADIAN GEM HAVE THE MORE
TYPICAL SQUALL LINE LOOK WITH MORE SW FLOW AND A DEEPER TROUGH
SUNDAY NIGHT. THE FLOW QUICKLY RETURNS TO A FLAT RIDGE LATER NEXT
MONDAY INTO TUESDAY.

DESPITE THE DECENT AGREEMENT AMONG MODELS...PREFER TO ONLY INCREASE
COVERAGE AND MOVE UP TIMING FOR THE NATURE COAST TO SUNDAY AFTN.
PCPN CHANCES KEPT IN THE ISOLD/SLIGHT CATEGORY FOR NOW...PENDING
FUTURE DATA WHICH SHOULD BEGIN TO SHOW A TREND. MY HUNCH IS THAT
GIVEN THE ACTIVE SPRING PATTERN THUS FAR THE TREND WILL BE WETTER.

&&

.MARINE...THE GULF WATERS COULD SEE SOME GUSTY WINDS THIS AFTERNOON
AND WILL ISSUE SCEC BUT OTHERWISE WINDS & SEAS ARE EXPECTED TO STAY
BELOW ANY HIGHLIGHTS AS THE FRONT MOVES THROUGH WED AND SHIFTS THE
WINDS. WINDS CONTINUE TO VEER AROUND AS HIGH PRESSURE MOVES ACROSS
THE COASTAL WATERS AND THEN OUT OVER THE ATLANTIC FOR THE WEEKEND.
ONE OTHER CONCERN WILL BE ANY THUNDERSTORMS THAT REACH SEVERE LATE
TODAY OR TONIGHT.

&&

.FIRE WEATHER...NO CONCERNS FOR THE NEXT COUPLE OF DAYS...HOWEVER
RH VALUES MAY BRIEFLY DROP BELOW 40 PERCENT THU AFTERNOON BUT STAY
ABOVE CRITICAL LEVELS.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA 80 68 81 66 / 30 60 40 00
FMY 85 69 83 66 / 20 50 60 20
GIF 85 67 82 64 / 30 60 40 00
SRQ 81 67 79 64 / 30 60 60 00
BKV 82 62 80 57 / 40 60 30 00

&&

.TBW WATCHES/WARNINGS/ADVISORIES...NONE.

$$

SHORT TERM...RKR
LONG TERM....BSG

[hurricanefloyd5]

a severethunderstorm watch in affected untill 9 tonight

[feederband]

At least we are seeing some action. April and May are usally boring, I hate boring weather.

[hurricanefloyd5]

Storm Prediction Center altocumulus 261613


Day 1 convective outlook
National Weather Service Storm Prediction Center Norman OK
1113 am CDT Tuesday Apr 26 2005


Valid 261630z - 271200z


There is a slight risk of severe thunderstorms to the right of a line from 40 southeast
bpt 20 west hez 20 southeast gwo bhm 25 S Atlantic 55 northwest ays ssi ... 25 south-southeast
vrb 10 west fmy.


General thunderstorms are forecast to the right of a line from 60 south-southeast lrd 20 S crp
... 15 south-southwest bpt 35 SW glh 55 north-northeast glh 25 west-southwest mem 50 south-southwest jbr 60
southeast hro 20 SW fyv 10 northwest tul 20 west-northwest bvo 40 S emp 15 S otm 10 S dbq 15
west-southwest jvl 35 east-southeast jvl azo 25 SW cak 15 west-southwest pit 30 east-northeast lbe 30 NE ipt 15
NE isp.


General thunderstorms are forecast to the right of a line from 80 northwest fca 15 west fca 15
west-northwest lvm 35 east-southeast evw 15 NE puc 40 northwest u17 35 SW bce 70 north-northwest bih 50 east-southeast
rbl eka ... 40 S onp 20 S sea 35 east-northeast bli.


General thunderstorms are forecast to the right of a line from 50 east-northeast dht 15 southeast csm
40 north adm 20 north-northwest dua 45 north-northwest Dal 70 west-northwest abi 35 S lbb 35 south-southeast cvs 30 NE
4cr 35 NE onm 35 west-southwest tcs 35 south-southeast sow 60 northwest gup 10 northwest dro 30 west-northwest tad
50 east-northeast dht.


..there is a slight risk of severe thunderstorms eastern Gulf Coast states...


..Ern Gulf Coast states...


Large amplitude trough extending from cold upper low over western
Ontario southward through western Great Lakes to lower MS valley. Very strong
wind fields rotating through bottom of trough at this time translating across
lower MS valley/middle Gulf Coast to southeastern U.S. Tonight.


Air mass recovery process ongoing over the Gulf of Mexico and
spreading inland across northestern Gulf coastal areas during the day.
With the strong westerly component and the upper support rotating rather
quickly across the southeastern states...only expect a limited amount of
instability will be able to develop inland prior to passage of upper
trough.


Ongoing marginally severe convective line from ncentral Alabama west-southwestward
across southern MS reflects the vertical motion associated with the shortwave
trough now rotating across lower MS valley. More vigorous
thunderstorms remain offshore over northern Gulf where Richer Gulf air
mass is available coupled with the strong shear.


Sufficient breaks in cloudiness along with low level moisture
advection to support development of weak to MDT surface based
instability during afternoon across southern Alabama/Georgia and Florida Panhandle.
With such very strong deep layer shear...60-70kt from sfc-6km...
even a limited amount of surface instability will result in a wind
damage threat with any line segments that develop within the current
line of convection. While the middle level lapse rates are relatively
cool and steep...the large hail potential will still be limited by
lack of strong instability and dominant westerly component limiting the
low level convergence.


Best opportunity for supercell and isolated tornado potential will
be nearer the northestern Gulf Coast where dewpoints will likely rise into
the middle/upper 60s Florida Panhandle this afternoon ahead of the trough.
Cloudiness will slow heating process ahead of storms...however
mlcapes to around 1000 j/kg could be available for supercell
development this afternoon northern Florida into southern Georgia/southeastern Alabama. Since the
shear and helicity is very favorable...supercells could easily form
along with isolated tornadoes given sufficient cape.


There will be a decreasing threat of severe overnight as the lines
of convection continue to move east and southeast across SC and Florida with the
upper trough rotating away from the better instability northestern Gulf
region.


.Hales/Jewell.. 04/26/2005


...
The station relative points in this product are now available
separately under the WMO headings wuus01 ptsdy1...
wuus02 ptsdy2...wuus03 ptsdy3. The inclusion of points
in this discussion will be discontinued after the 2005
convective season. A public notification statement (pns)
will provide details on the transition.










Mesoscale Discussion


042
acus11 kwns 261854
sels mesoscale discussion
Storm Prediction Center mesoscale discussion 261854
gaz000-flz000-alz000-msz000-laz000-262000-


Mesoscale discussion 0695
National Weather Service Storm Prediction Center Norman OK
0154 PM CDT Tuesday Apr 26 2005


Areas affected...southeast MS into central/southern Alabama/SW Georgia/western Florida Panhandle


Concerning...Severe Thunderstorm Watch 205...


Valid 261854z - 262000z


Trends continue to be monitored for possibility of new ww. Current
indications are ww 205 will be allowed to expire at 21z.


Convectively-generated boundary has progressed into the Interstate
65 corridor of southern Alabama. However...southward advance toward
southern Mississippi coastal areas has been a bit slower...with middle-
level trough axis just now progressing through central
Mississippi/south central Louisiana. Band of forcing along/ahead of
this feature has become focus for convective development...south of
boundary near Lake Ponchartrain into areas north of
boundary...across southwest Alabama.


Cape in mixed boundary layer south of outflow...and moist layer
above outflow...is on the order of 1000 j/kg...and will remain
supportive of large hail threat in favorable cool/sheared
environment through the afternoon. To this point...hail has only
been marginally in excess of severe limits...but activity south of
outflow could still intensify a bit further this afternoon as it
spreads across the Mobile area into the Florida Panhandle.


. 04/26/2005


. see http://www.Spc.NOAA.Gov for graphic product...


Attention...wfo...ffc...tae...bmx...mob...Jan...lix...


30779063 31118927 31668791 32468684 32808618 32718541
32188462 31278464 29718578 29368699 29088905 29749094

[chadtm80]

And this is our Dry season, so this rain is very much "appreciated"

http://storm2k.nhcwx.com/hw3.php?config ... one=FLZ041

http://storm2k.nhcwx.com/hw3.php?config ... ption|pass