000 AXPZ20 KNHC 262137 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT JAN 26 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 3N77W 6N88W 3N97W 11N125W 8N128W 8N140W. NO SIGNIFICANT CONVECTION. ...DISCUSSION... W OF 105W... A DEEP-LAYERED CUT-OFF LOW AND ASSOCIATED TROUGH REMAINS LOCATED OFF THE CALIFORNIA COAST WITH A 1000 MB SURFACE LOW CENTERED ABOUT 730 NM W OF SAN DIEGO NEAR 32N132W...AND A COLD FRONT SURGING ACROSS THE AREA FROM 30N126W TO 21N130W TO 18N140W. THE UPPER TROUGH IS BECOMING NEGATIVELY TILTED NOW AS THE VIGOROUS 110+ KT UPPER LEVEL JET HAS BECOME ESTABLISHED ON THE SE PERIPHERY OF THE TROUGH. THE JET ALSO APPEARS TO BE SPLITTING WITH ONE BRANCH STREAMING ENE INTO SOUTHERN ARIZONA AND NEW MEXICO INTO THE SUBTROPICAL JET STREAM...AND THE OTHER PART RUNNING NORTHWARD OFF THE CALIFORNIA COAST INTO THE POLAR JET LOCATED ACROSS THE PACIFIC NORTHWEST. A LARGE AREA OF UPPER DIFFLUENCE E OF THE TROUGH AXIS IS PRODUCING WIDESPREAD CLOUDINESS N OF 13N E OF 128W INTO N/CENTRAL MEXICO WITH EMBEDDED SCATTERED SHOWERS AND ISOLATED TSTMS MAINLY ALONG A PRE-FRONTAL RAIN BAND EXTENDING FROM 30N119W TO 20N125W. THE MOISTURE SURGE AHEAD OF THE SYSTEM IS POISED TO REACH BAJA CALIFORNIA BY SUN MORNING AND HAS THE POTENTIAL TO BRING SCATTERED SHOWERS TO THE PENINSULA THROUGH AT LEAST EARLY TUE. W OF THE FRONT...THE SURFACE LOW IS ROTATING S/SE TOWARDS 30N AND IS EXPECTED THE BRUSH THE REGION TONIGHT WITH A 25-35 KT WIND MAXIMUM READY TO SWING THROUGH THE NORTHERN LATITUDES OF THE AREA W OF 120W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE LOCATED WITHIN THE UNSTABLE AIR BEHIND THE FRONT N OF 26N BETWEEN THE FRONT AND 135W. FARTHER S...A 1012 MB LOW IS LOCATED IN THE TROPICS NEAR 12N125W BUT DEFINITELY HAS MORE BAROCLINIC FORCING THAN WOULD BE EXPECTED AT THAT LATITUDE. UPPER LEVEL WINDS ARE PRIMARILY WESTERLY S OF 20N BUT PART OF THE FLOW SPLITS TO THE NE NEAR 125W IN RESPONSE TO THE CUT-OFF TROUGH TO THE N...AND IS RESULTING IN FAVORABLE UPPER DIFFLUENCE OVER THE SURFACE LOW. SCATTERED SHOWERS AND ISOLATED TSTMS ARE LOCATED PRIMARILY TO THE N AND NE OF THE LOW FROM 12N-15N BETWEEN 121W-125W. OTHER ELEVATED ACTIVITY EXTENDS FARTHER NE TOWARDS THE BAJA PENINSULA DUE TO EXCELLENT ISENTROPIC LIFT OF TROPICAL MOISTURE IN THE LOW TO MID LEVELS. E OF 105W... THE UPPER LEVEL PATTERN OVER MUCH OF SE MEXICO AND CENTRAL AMERICA IS DOMINATED BY A WEAK REX BLOCK WITH RIDGING OCCURRING FROM 10N105W NE TO THE YUCATAN PENINSULA AND TROUGHING FROM THE CAYMAN ISLANDS SW ACROSS HONDURAS/EL SALVADOR TO 4N95W. IN ADDITION...A LARGE MID-LEVEL HIGH IS CENTERED NEAR THE N COAST OF THE YUCATAN PENINSULA WITH AXIS ALONG 22N. THIS PATTERN IS PRODUCING MODERATE/STRONG SUBSIDENCE E OF 100W AND SUPPRESSING MOST DEEP CONVECTION. RELATIVELY DRY LOW-LEVEL AIR AND THE MID-LEVEL SUBSIDENCE IS ALSO PRODUCING TEMPERATURES ACROSS PARTS OF CENTRAL AMERICA...ESPECIALLY NEAR THE PACIFIC COAST...WHICH ARE SEVERAL DEGREES ABOVE NORMAL. THE HIGHEST TEMPERATURE NOTED SO FAR THIS AFTERNOON IS 95 F (35 C) FROM THE CITY OF AMAPALA HONDURAS NEAR THE GULF OF FONSECA. GAP WINDS CONTINUE THROUGH TEHUANTEPEC...PAPAGAYO...AND PANAMA AND THE RESULTANT NORTHERLY LOW-LEVEL FLOW HAS PUSHED THE ITCZ WELL S TO NEAR 5N. $$ BERG