SWOMCD
SPC MCD 310002
FLZ000-310200-
MESOSCALE DISCUSSION 2189
NWS STORM PREDICTION CENTER NORMAN OK
0702 PM CDT SAT AUG 30 2008
AREAS AFFECTED...FL KEYS...EXTREME S FL.
CONCERNING...TORNADO WATCH 874...
VALID 310002Z - 310200Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 874 CONTINUES.
INCREASE NOTED IN ORGANIZATION AND COVERAGE OF DISCRETE CELLS DURING
LAST 1-2 HOURS OVER CUBA AND FL STRAITS...BASED ON REFLECTIVITY
ANIMATIONS AND SATELLITE IMAGERY. THIS ACTIVITY WILL CONTINUE TO
CROSS LOWER-MIDDLE KEYS THROUGH 01Z...FOLLOWED BY BKN BAND EVIDENT
FARTHER SE THAT SHOULD AFFECT KEYS IN 01Z-03Z TIME FRAME.
KINEMATIC PROFILES ARE FAVORABLE FOR SUCH STORMS TO ROTATE
PERSISTENTLY AND PRODUCE A FEW TORNADOES AS THEY CROSS KEYS...GIVEN
OBSERVED VWP HODOGRAPHS AT EYW AND MODIFICATION OF RELATIVELY WEAK
MFL HODOGRAPHS FOR RADAR-INDICATED WINDS ALOFT FARTHER SW OVER
MID/UPPER KEYS. FOR ANOTHER SEVERAL HOURS...0-1 KM SRH SHOULD
CONTINUE TO RANGE FROM 350-500 K/KG AROUND EYW AND MARQUESAS
KEYS...TO 150-200 J/KG BETWEEN HST AND KEY LARGO NWWD ACROSS MOST OF
MAINLAND MONROE COUNTY. WITHOUT APPRECIABLE EXPANSION OF WIND FIELD
DURING NEXT SEVERAL HOURS...WHICH IS NOT FCST BY NHC...LOW LEVEL
SHEAR PROFILES IN OUTER PERIPHERY OF CIRCULATION ENVELOPE SHOULD
PEAK WITHIN 3-4 HOURS AS TWO THINGS OCCUR...
1. NE-SW AXIS NORMAL TO STORM MOTION PASSES EYW...EXPOSING GREATEST
LENGTH OF WW AREA TO FAVORABLE WIND FIELDS IN NERN SEMICIRCLE...AND
2. CORE WINDS INTENSIFY AFTER MOVING OFF NWRN CUBA...AS FCST BY NHC.
TORNADO THREAT DURING THAT TIME FRAME WILL BE DICTATED LARGELY BY
FORTUITOUS JUXTAPOSITION OF STORM MODE AND LAND CROSSING...AMIDST
VERY STG SHEAR...MRGLLY FAVORABLE LOW LEVEL BUOYANCY AND NEARLY
MOIST-ADIABATIC DEEP-LAYER LAPSE RATES. REF NHC ADVISORIES UNDER
WMO HEADER WTNT22 KNHC FOR LATEST TROPICAL WATCHES/WARNINGS AND
TRACK/INTENSITY FCST.
..EDWARDS.. 08/31/2008
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MFL...KEY...
24648295 24588240 24628191 24788148 24838105 24958098
25068104 25158112 25338117 25468117 25678128 25798139
25818087 25328024 25048045 24808075 24678110 24638135
24518173 24528192 24538250 24588284
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.
No comments:
Post a Comment