000
AXPZ20 KNHC 190318
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON NOV 19 2007

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...TROPICAL WAVES...

TROPICAL WAVE LOCATED OVER THE WEST COAST OF COSTA RICA AND 
WESTERN NICARAGUA ALONG 86W N OF 5N MOVING W 10 KT. A FAIRLY 
WELL-DEFINED AXIS...FOR MID-NOVEMBER...IS VISIBLE MOVING ACROSS 
CENTRAL AMERICA WITH SCATTERED SHOWERS/TSTMS TO THE N OVER THE 
GULF OF HONDURAS. SOUTHWESTERLY SHEAR IS KEEPING THE DEEPEST 
CONVECTION E OF THE WAVE AXIS WHERE SCATTERED MODERATE 
CONVECTION IS LOCATED OVER THE SW CARIBBEAN.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG THE LINE...4N77W 8N105W 11N140W. 
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN THE AREA FROM 
8N TO 10N FROM 110W TO 113W. SCATTERED MODERATE CONVECTION IS 
WITHIN 120 NM EITHER SIDE OF AXIS W OF 113W.

...DISCUSSION...

THE GENERAL LONGWAVE PATTERN FEATURES TWO RIDGES AND TWO TROUGHS 
WITHIN AND FLANKING THE DISCUSSION AREA. FIRST...AN UPPER RIDGE 
AXIS IS LOCATED E OF THE AREA OVER THE CENTRAL CARIBBEAN ALONG 
73W WITH DOMINATING MID-LEVEL HIGH CENTERED OVER THE GREATER 
ANTILLES. WIDESPREAD MODERATE/STRONG SUBSIDENCE LIES E OF 
95W BENEATH THE RIDGE ALTHOUGH SOME AREAS OF CONVECTION ARE 
LOCATED ALONG AND E OF THE TROPICAL WAVE ALONG 86W. ABUNDANT 
LOW-LEVEL DRY AIR COVERS THE PACIFIC WATERS N OF THE ITCZ E OF 
120W ALTHOUGH DEEP MOISTURE WILL GRADUALLY INCREASE FROM EAST TO 
WEST OVER THE NEXT FEW DAYS WITH THE PASSAGE OF THE WAVE.

AN UPPER TROUGH AXIS...PARTIALLY CUT-OFF FROM THE PREVAILING 
MID-LATITUDE WESTERLIES OVER THE EASTERN UNITED STATES...EXTENDS 
FROM EASTERN TEXAS SW ACROSS CENTRAL MEXICO TO 15N108W...WITH 
INDICATIONS OF A DEVELOPING CYCLONIC CIRCULATION CENTER NEAR THE 
SOUTH TIP OF BAJA CALIFORNIA. ALTHOUGH THE SHARPEST PART OF THE 
TROUGH LIES N OF THE TROPICS...BROAD CYCLONIC CURVATURE IS NOTED 
IN THE UPPER LEVEL WINDS FARTHER S AS WELL. MODERATE/STRONG 
SUBSIDENCE COVERS WESTERN MEXICO N OF LINE 20N105W TO 30N100W
BENEATH THE TROUGH AXIS WHILE SCATTERED MID/HIGH CLOUDINESS IS 
MOVING NE WITHIN 240 NM SOUTHEAST OF THIS LINE.

A WEAK OMEGA BLOCK IS LOCATED JUST W OF BAJA CALIFORNIA WITH A 
NEARLY STATIONARY RIDGE AXIS ALONG 120W BORDERED BY THE TROUGH 
OVER MEXICO AND A SHARPER TROUGH NE OF HAWAII. THE RIDGE IS 
DEEP-LAYERED AND IS REFLECTED AS A 1021 MB HIGH NEAR 
30N129W...ALL OF WHICH IS PRODUCING AN OVERCAST/BROKEN BUT 
RELATIVELY SHALLOW MARINE LAYER N OF 20N.  UPPER DIVERGENCE E OF 
THE LOW IS PRODUCING BROKEN MID/HIGH LEVEL CLOUDS N OF 15N W OF 
133W. THE UPPER LEVEL FLOW IS PRIMARILY WESTERLY S OF 15N 
ALTHOUGH THERE IS ENOUGH DIFFLUENCE WHERE SOME OF THE WINDS TURN 
TO THE SE TO ENHANCE DEEP CONVECTION ALONG THE ITCZ BETWEEN 
105W-140W.

$$
LL