000
AXPZ20 KNHC 300350
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI NOV 30 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 
0330 UTC.
 
...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N78W 7N100W 14N117W 
10N127W 8N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 
90-120 NM OF THE AXIS BETWEEN 109W AND 112W. SCATTERED MODERATE 
FROM 9N TO 14N BETWEEN 120W AND 125W. 

SCATTERED MODERATE ISOLATED STRONG CONVECTION FROM 18N TO 24N 
BETWEEN 115W AND 119W...AND FROM 14N TO 18N BETWEEN 107W AND 
110W. 

...DISCUSSION...

E OF 110W...
A STRONG MID-LEVEL HIGH IS CENTERED OVER THE YUCATAN CHANNEL AND 
NW CARIBBEAN WITH AN UPPER RIDGE AXIS EXTENDING NWWD FROM 
NORTHERN COLOMBIA NW TO E TEXAS. DUE TO THE ORIENTATION OF THE 
RIDGE...THE FLOW ALOFT E OF 100W IS PRIMARILY SOUTHERLY BUT A 
LACK OF MOISTURE S OF THE EQUATOR IS PRODUCING MAINLY DRY AIR 
NEAR CENTRAL AMERICA. SPORADIC DEEP CONVECTION IS OCCURRING 
ALONG THE ITCZ E OF 110W...BUT THE LOW-LEVEL ENVIRONMENT N OF 
THE AXIS IS ALSO RATHER DRY. A 0054 UTC QUIKSCAT PASS INDICATED 
A WEAK GAP WIND EVENT IS OCCURRING OVER THE GULF OF TEHUANTEPEC 
WITH 20 TO 25 KT WINDS. GAP WINDS ARE ALSO OCCURRING IN THE GULF 
OF PAPAGAYO. ELSEWHERE...A SHEARED UPPER LEVEL SHORTWAVE TROUGH 
IS LOCATED ALONG 101W OVER CENTRAL MEXICO AND THE ADJACENT 
WATERS...PRODUCING ADDITIONAL SUBSIDENCE OVER THE AREA N OF 15N 
E OF 104W.

W OF 110W...
THE MAJOR WEATHER MAKER OVER THE SUBTROPICAL PACIFIC WATERS IS 
A PERSISTENT AND LARGE CUT-OFF LOW CENTERED W OF BAJA CALIFORNIA 
NEAR 26N125W WHICH IS EXPECTED TO REMAIN NEARLY STATIONARY FOR 
ANOTHER 12-18 HRS OR SO...THEN LIFT NE AND BECOME ABSORBED BY A 
LARGER UPPER TROUGH OVER THE WESTERN UNITED STATES. STRONG UPPER 
DIFFLUENCE IS OCCURRING SE OF THE LOW WHERE PART OF THE FLOW 
TURNS NE INTO NW MEXICO AND THE OTHER PART TURNS SE PAST THE 
EQUATOR. THIS HAS CAUSED SURFACE PRESSURES TO LOWER IN THE AREA 
WITH A 1011 MB SURFACE LOW NEAR 24N121W ALONG A TROUGH EXTENDING 
FROM THE LOW TO 12N124W. THE LOW IS EXPECTED TO LIFT NE INTO 
SOUTHERN CALIFORNIA AND ARIZONA BY SAT MORNING. THERE IS THE 
POTENTIAL FOR SIGNIFICANT RAINFALL OVER PARTS OF BAJA 
CALIFORNIA...SONORA...SINALOA...AND CHIHUAHUA THROUGH SAT DUE TO 
THE DEEP PLUME OF MOISTURE THAT WILL STREAM IN FROM THE SOUTH. 
THEREAFTER...THE LOW WILL LIKELY CONTRIBUTE TO A SIGNIFICANT 
WINTER STORM OVER PARTS OF THE ROCKIES AND CENTRAL PLAINS EARLY 
NEXT WEEK.

ELSEWHERE...MODERATE/STRONG SUBSIDENCE IS OCCURRING ON THE BACK 
SIDE OF THE CUT-OFF LOW WHERE THE FLOW IS CONVERGING INTO THE 
BASE OF THE TROUGH. THERE IS VERY LITTLE CLOUD COVER AT THE 
MOMENT AND THE TRADES ARE ACTUALLY EXPECTED TO WEAKEN OVER THE 
NEXT FEW DAYS AS LOW PRES DEVELOPS TO THE E AND BREAKS DOWN THE 
RIDGE. 

IN THE LONGER TERM...NUMERICAL MODELS ARE FORECASTING A 
SIGNIFICANT STORM CENTER TO DEVELOP WELL NW OF THE AREA WITH
AN INCREASE IN SW WINDS TO 20 TO 25 KT BY 48 HOURS AND THE 
POTENTIAL FOR GALE FORCE WINDS OR HIGHER BY 72 HOURS AND BEYOND 
WITH LARGE NW SWELLS/SEAS EXCEEDING 20 FT. 
  
$$
COBB