AFDCRP AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 642 AM CDT MON APR 18 2011 .DISCUSSION...UPDATED AVIATION DISCUSSION FOR 12Z TAFS. && .AVIATION...DRIER AIR MIXING IN THE MVFR STRATUS DECK OVER THE COASTAL PLAINS THIS MORNING...WITH LARGE HOLES IN THE STRATUS VISIBLE IN SATELLITE IMAGERY. THEREFORE...EXPECT VFR CONDITIONS BY MID MORNING AREAWIDE. BREEZY SOUTHEAST WINDS ARE EXPECTED ACROSS THE COASTAL PLAINS...WITH GUSTS TO AROUND 30 KNOTS POSSIBLE THIS AFTERNOON. MVFR STRATUS DECK WILL MOVE IN QUICKLY THIS EVENING AS A 50 KNOT LLJ DEVELOPS AND CONTINUE THROUGH THE END END OF THE TAF PERIOD. ALSO ADDED NON-CONVECTIVE LLWS IN THE TAFS FOR THE COASTAL BEND DUE TO THE 50 KNOT LLJ. && .PREV DISCUSSION... /ISSUED 407 AM CDT MON APR 18 2011/ SHORT TERM (TODAY THROUGH TUESDAY)...LOW PRESSURE STRENGTHENING OVER THE TEXAS PANHANDLE AND HIGH PRESSURE OVER THE SOUTHEAST IS LEADING TO A 45-50 KNOT LLJ OBSERVED ON VAD WIND PROFILE OVER THE COASTAL BEND. LOW STRATUS ACROSS MOST OF THE REGION IS EXPECTED TO SCATTER OUT BY LATE MORNING AND BREEZY TO WINDY SOUTHEAST WINDS WITH GUSTS TO 35 MPH ARE EXPECTED ACROSS THE COASTAL BEND. MUCH WARMER TEMPERATURES BEING OBSERVED THIS MORNING ACROSS THE REGION...WITH TEMPERATURES IN THE LOW 70S AREAWIDE. THE NAM TRIES TO PUSH A DRYLINE INTO THE RIO GRANDE PLAINS THIS AFTERNOON WITH RH VALUES FALLING TO 20 TO 30 PERCENT...BUT THIS FEATURE IS NOT EXPECTED TO MAKE IT VERY FAR TO THE EAST TODAY. IN ADDITION...WINDS WILL REMAIN RELATIVELY LIGHT ACROSS THE WEST. THIS WILL LEAD TO VERY WARM TEMPERATURES THIS AFTERNOON ACROSS THE WEST WITH HIGHS FROM 95 TO 105 DEGREES. ELSEWHERE...HIGHS WILL BE IN THE MID 80S TO THE LOWER 90S. WARM AND MUGGY OVERNIGHT LOWS ARE EXPECTED FOR TUESDAY MORNING...WITH TEMPERATURES IN THE LOW TO MID 70S. A 45-50 KNOT LLJ WILL REDEVELOP OVER THE COASTAL PLAINS LEADING TO MORE LOW STRATUS ACROSS THE REGION. LOW PRESSURE ACROSS THE SOUTHERN PLAINS WILL BEGIN TO MOVE OFF TO THE NORTHEAST ON TUESDAY IN RESPONSE TO AN UPPER LEVEL DISTURBANCE MOVING ACROSS THE MIDWEST. THIS WILL PUSH A MUCH MORE PRONOUNCED DRYLINE ACROSS THE RIO GRANDE PLAINS AND BRUSH COUNTRY. THE NAM IS VERY AGGRESSIVE WITH DEWPOINTS DROPPING INTO THE LOW 20S ACROSS THE RIO GRANDE. SPLIT THE DIFFERENCE WITH MOS...AND THIS STILL WOULD LEAD TO VERY LOW RH VALUES ACROSS THE WEST ON TUESDAY. HOWEVER...WINDS ARE EXPECTED TO BE AROUND 10 TO 15 MPH. AN ELEVATED FIRE DANGER THREAT WILL EXIST ACROSS THE RIO GRANDE PLAINS AND BRUSH COUNTRY DUE TO THE LOW RH AND MODERATE WINDS. WITH WEST TO SOUTHWEST WINDS ALOFT BRINGING IN VERY DRY AND WARM TEMPERATURES ALOFT...STRONG MIXING AND ADIABATIC WARMING WILL LEAD TO VERY HOT TEMPERATURES ACROSS THE WESTERN TWO-THIRDS OF TEXAS ON TUESDAY. HIGHS MAY APPROACH 110 DEGREES ACROSS THE RIO GRANDE. THE RECORD HIGH FOR LAREDO ON TUESDAY IS 105 DEGREES...AND THE ALL TIME RECORD FOR THE MONTH OF APRIL IS 112 SET ON APRIL 28TH IN 1937. HIGH TEMPERATURES MAY APPROACH 100 AS FAR EAST AS JIM WELLS AND LIVE OAK COUNTIES. BREEZY TO WINDY SOUTHEAST FLOW IS EXPECTED ACROSS THE COASTAL PLAINS ONCE AGAIN WITH TEMPERATURES IN THE UPPER 80S TO THE MIDDLE 90S. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...IN RESPONSE TO AN UPPER DISTURBANCE...A FRONT IS PROGD TO ENTER THEN STALL AS FAR SOUTH AS CENTRAL TX WEDNESDAY. EVEN IF SHOWERS DEVELOP ALG THE FRONT...HIGH CIN OVER THE CWA WILL PRECLUDE ACTIVITY OVR THE CWA. AFTERWARD...THE MODELS PROG A QUASI-ZONAL UPPER PATTERN OVR MUCH OF THE CONUS EXCEPT FOR A FEW DISTURBANCES. THE GFS AND ECMWF DIVERGE WITH REGARD TO THE TIMING OF THESE SYSTEMS. THE GFS PROGS AN UPPER DISTURBANCE TO MOVE ACRS THE PLAINS FRIDAY YET THE ECMWF MAINTAINS A QUASI-ZONAL FLOW. EITHER SOLN SUGGESTS AN ONSHORE FLOW WITH DIFFERENCES IN WIND MAGNITUDES OVR THE CWA/MSA. WILL FCST GREATER WIND SPEEDS FRIDAY TO ACCOUNT FOR UNCERTAINTY. THE MODELS DIFFER AGAIN REGARDING THE NEXT SYSTEM WITH THE ECMWF FCSTG A MUCH STRONGER UPPER TROUGH OVER THE WRN CONUS SUNDAY. AGAIN...EITHER SOLN MAINTAINS ONSHORE FLOW OVR THE CWA/MSA. DRG THE PERIOD...ONSHORE FLOW WILL MAINTAIN AN INFLUX OF GULF MSTR YET GFS PROGS MSTR TO EXTEND ONLY TO AROUND 950MB...WITH A STRONG THERMODYNAMIC CAP DIRECTLY ABOVE THE MSTR LAYER. THUS EXPECT MOSTLY CLOUDY NIGHTS/PARTLY SUNNY DAYS WITH NO PCPN. MARINE...CANCELLED THE SMALL CRAFT ADVISORY ACROSS THE AREA THIS MORNING AS WINDS HAVE REMAINED BELOW CRITERION. ALTHOUGH A 35 KNOT LLJ IS PRESENT OVER THE GULF WATERS...INCREASING STABILITY IS NOT ALLOWING THE WINDS TO MIX TO THE SURFACE OF THE WATER. EXPECT SCEC CONDITIONS ACROSS MOST OF THE GULF WATERS TODAY. HOWEVER...DUE TO AN INCREASING TEMPERATURE AND PRESSURE GRADIENT THIS AFTERNOON...SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED ACROSS THE SOUTHERN NEARSHORE WATERS AND SOUTHERN BAYS. THEREFORE...A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THOSE AREAS THIS AFTERNOON THROUGH TONIGHT. SCA CONDITIONS ARE LIKELY TO CONTINUE FOR THE SOUTHERN BAYS AND SOUTHERN NEARSHORE WATERS THROUGH TUESDAY. SEAS MAY BUILD TO AROUND 7 FEET ACROSS THE OFFSHORE WATERS DUE TO THE LONG FETCH. FIRE WEATHER...A DRYLINE MAY IS EXPECTED TO MOVE THROUGH THE RIO GRANDE PLAINS TODAY AND RH VALUES WILL LIKELY DROP TO 20 TO 30 PERCENT. WINDS WILL VEER TO THE SOUTHWEST...BUT REMAIN LESS THAN 15 MPH. ELSEWHERE...RH VALUES WILL FALL TO 45 TO 75 PERCENT. A MUCH MORE PRONOUNCED DRYLINE IS EXPECTED TO MOVE THROUGH THE RIO GRANDE PLAINS AND BRUSH COUNTRY ON TUESDAY AS LOW PRESSURE ACROSS THE SOUTHERN PLAINS MOVES OFF TO THE EAST. THIS WILL LEAD TO VERY HOT TEMPERATURES AND RH VALUES OF 8 TO 15 PERCENT ACROSS THE WEST. WINDS ARE EXPECTED TO BE 10 TO 15 MPH...BUT THE LOW RH VALUES WILL LEAD TO AN ELEVATED FIRE DANGER THREAT FOR THE BRUSH COUNTRY AND RIO GRANDE PLAINS. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 88 74 91 75 87 / 0 0 0 10 10 VICTORIA 89 73 92 73 88 / 0 0 0 10 10 LAREDO 105 77 109 76 102 / 0 0 0 10 10 ALICE 95 73 99 73 92 / 0 0 0 10 10 ROCKPORT 82 75 86 76 82 / 0 0 0 10 10 COTULLA 99 71 104 71 98 / 0 0 0 10 10 KINGSVILLE 93 73 96 74 89 / 0 0 0 10 10 NAVY CORPUS 82 75 86 75 81 / 0 0 0 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY FOR WINDS FROM 3 PM THIS AFTERNOON TO MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM. && $$