[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 171122
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SAT FEB 17 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...
CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...
NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC
OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N.
THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...
METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N10W 3N25W 1N34W...CROSSING THE
EQUATOR NEAR 39W...2S41W INTO NORTHEASTERN BRAZIL NEAR 3S45W.
CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 180 NM
EITHER SIDE OF THE AXIS E OF 17W AND W OF 32W. ISOLATED MODERATE
IS WITHIN 120 NM EITHER SIDE BETWEEN 26W-32W.

...DISCUSSION...
THE GULF OF MEXICO...
FAIR WEATHER IS THE RULE ACROSS THE AREA THIS MORNING THANKS IN
PART TO A 1023 MB HIGH PRES SYSTEM IN THE CENTRAL GULF NEAR
25N90W. NEARLY ALL OF THE LOW TO MID LEVEL CLOUD DECK THAT
PLAGUED THE SRN GULF OVER THE PAST FEW DAYS HAS THINNED AND
PUSHED SWD WITH THE FRONT NOW IN THE NW CARIB. THE ONLY AREA OF
NOTABLE CLOUD COVER IS IN THE WRN BAY OF CAMPECHE ASSOCIATED
WITH SLY RETURN FLOW. SCATTERED COLD AIR STRATOCUMULUS CLOUDS
ARE SEEN ON IR IMAGES OVER MOST OF THE ERN HALF OF THE
REGION...NAMELY E OF THE SFC HIGH. THESE CLOUDS ARE AN
INDICATION OF THE COLD AIRMASS IN PLACE. IN FACT...THIS MORNING
IS THE COLDEST THIS WINTER FOR MANY LOCATIONS IN FLORIDA. SFC
WINDS HAVE RELAXED A GREAT DEAL SINCE YESTERDAY AT THIS TIME DUE
TO THE WEAK SFC PATTERN...BUT THEY WILL NOT STAY LIGHT FOR LONG
AS A   REINFORCED COLD FRONT...CURRENTLY DRAPED ACROSS THE
CENTRAL U.S...ENTERS THE GULF THIS MORNING AND RACES ACROSS THE
REGION CLEARING THE ENTIRE AREA BY TOMORROW MORNING. NLY WINDS
WILL INCREASE BEHIND THE FRONT AS STRONG HIGH PRES BUILDS SWD IN
ITS WAKE.

THE CARIBBEAN SEA...
THE TAIL END OF A WEAKENING COLD FRONT EXTENDS FROM CENTRAL CUBA
TO HONDURAS ALONG 21N78W 18N83W 14N87W. THE FRONT IS MOST EASILY
NOTED BY A SURGE IN NLY WINDS AS INDICATED BY A QSCAT PASS NEAR
00 Z. A WEAK PREFRONTAL TROUGH IS ANALYZED FROM 19N79W TO 14N81W
SHIFTING THE WINDS FROM E/NE TO NW PRIOR TO THE FRONTAL PASSAGE.
BROKEN PATCHES OF LOW TO MID LEVEL CLOUDS LIE OVER CUBA AND
PARTS OF THE NW CARIB. THERE MAY BE ISOLATED SHOWERS EMBEDDED
BUT NO ORGANIZED ACTIVITY AS SUGGESTED BY DOPPLER RADAR IN CUBA.
ELSEWHERE THE MAIN WEATHER FEATURE IS A VERY BROAD STRONG UPPER
LEVEL RIDGE STRETCHING ACROSS THE REGION. THE RIDGE HAS
FLATTENED IN THE WRN CARIB IN RESPONSE TO A LARGE UPPER TROUGH
ENCOMPASSING THE ERN U.S. THIS RIDGE CONTINUES TO SUPPLY AN
ABUNDANT AMOUNT OF DRY AIR/SUBSIDENT FLOW ALOFT SUPPRESSING ANY
SIGNIFICANT TSTM ACTIVITY. THE DRIEST AIR IS IN THE UPPER
CONFLUENT ZONE BETWEEN HISPANIOLA AND VENEZUELA/COLOMBIA.
BENEATH THE STRONG MID LEVEL CAP...SMALL PATCHES OF LOW-LEVEL
MOISTURE ARE BEING STEERED BY LIGHT TO MODERATE ELY TRADES E OF
THE PREFRONTAL TROF. LOOKING AHEAD FOR A DAY OR SO...THE STRONG
NLY WINDS IN THE NW CARIB ARE EXPECTED TO SUBSIDE SLIGHTLY
DURING THE DAY TODAY AND THEN QUICKLY RAMP UP AGAIN ON SUN
BEHIND A QUICK MOVING REINFORCING COLD FRONT.

THE ATLANTIC OCEAN...
A COLD FRONT ENTERS THE AREA NEAR 32N56W AND CONTINUES SW ALONG
26N66W TO THE COAST OF CUBA NEAR 21N77W. LOW LEVEL LIFT NEAR THE
FRONT ALONG WITH SOME UPPER ENERGY FROM A SUBTROPICAL JET RACING
THRU THE AREA IS PRODUCING BROKEN TO OVERCAST MULTILAYERED
CLOUDS WITH EMBEDDED SHOWERS ROUGHLY WITHIN 300 NM NW OF THE
FRONT. A SFC TROUGH ENTERS THE AREA NEAR 32N61W AND CONTINUES
WSW TO NE FLA NEAR 29N81W...ADDING A LITTLE CYCLONIC CURVATURE
TO THE PREDOMINANT STRONG NW WINDS BLOWING OFFSHORE THE SE U.S.
THE REMAINDER OF THE SFC PATTERN IN THE ATLC AREA IS DOMINATED
BY THE SRN PERIPHERY OF A 1028 MB HIGH NEAR 36N24W. THIS IS
SUPPLYING MOSTLY FAIR WEATHER AND MODERATE TRADES ACROSS A GOOD
PORTION OF THE CENTRAL AND E ATLC. THE SFC WINDS ARE
STRONGEST...SWLY GALE FORCE...WITHIN 240 NM E OF THE FRONT N OF
29N...IN THE TIGHT GRAD BETWEEN THE RIDGE AND THE FRONT. THE MID
TO UPPER LEVEL PATTERN HAS AMPLIFIED A LITTLE DOMINATED BY A
LARGE RIDGE OVER THE WRN AND CENTRAL ATLC W OF 45W AND A BROAD
TROUGH E OF THERE. WHILE THE PATTERN IS MORE AMPLIFIED...THERE
IS LITTLE SIGNIFICANT ASSOCIATED MOISTURE. THE ONLY AREA OF ANY
SIGNIFICANT DEEP MOISTURE IS IN THE ITCZ...WHICH IS QUITE ACTIVE
TODAY. STRONG SWLY WINDS IN THE UPPER LEVELS AND DIFFLUENCE IS
FAVORING CONVECTION ALONG THE AXIS.

$$
CANGIALOSI




This weather bulletin was brought to you by:
www.nashvilleweather.net