760 FXUS65 KPUB 231958 AFDPUB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 158 PM MDT THU MAY 23 2013 .UPDATE... ISSUED AT 154 PM MDT THU MAY 23 2013 UPDATED FORECAST TO INTRODUCE FIRE WEATHER WATCH FOR THE EASTERN MOUNTAINS...TELLER AND EL PASO COUNTIES FROM NOON UNTIL 8 PM MDT FRIDAY. UPDATE ISSUED AT 125 PM MDT THU MAY 23 2013 UPDATED SHORT TERM FORECASTS TO REFLECT CURRENT OBSERVATIONS AND TRENDS. LW UPDATE ISSUED AT 1030 AM MDT THU MAY 23 2013 UPDATED FORECASTS TO REFLECT CURRENT OBSERVATIONAL TRENDS. HELD ONTO CLOUDS AND FOG LONGER. ADJUST TEMPS DOWN ACROSS THE PLAINS. MAY BE VERY SLOW TO CLEAR COMPLETELY IN A LOT OF AREAS ACROSS THE PLAINS DUE TO THE PERSISTENT LOW LEVEL UPSLOPE FLOW. LW && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM MDT THU MAY 23 2013 LOW LEVEL E-SE UPSLOPE FLOW GRADUALLY DEEPENING OVER THE EASTERN MOUNTAINS AND PLAINS THIS MORNING...AND A RAPID EXPANSION OF MVFR STRATUS WAS OCCURRING ALONG AND EAST OF THE MOUNTAINS AS OF 10Z. ALSO APPEARS LOW LEVEL MOISTURE AND CLOUDINESS HAS WORKED WESTWARD INTO THE UPPER ARKANSAS VALLEY...AS SALIDA AND BUENA VISTA HAVE BECOME OVERCAST. EXPECT STRATUS DECK WILL CONTINUE TO EXPAND THE NEXT SEVERAL HOURS...COVERING MUCH OF THE EASTERN MOUNTAIN SLOPES AND PLAINS BY MID-MORNING. MODELS THEN SUGGEST STRATUS WILL DIMINISH BY EARLY AFTERNOON...ESPECIALLY OVER THE EASTERN MOUNTAINS AND I-25 CORRIDOR. WITH SOME SOME SUN...AIR MASS BECOMES WEAKLY UNSTABLE BY LATE AFTERNOON...AS LIFTED INDICES FALL INTO THE MINUS 2 TO MINUS 4 RANGE WHILE CAPES CLIMB TO 500-1000 J/KG...WITH THE GREATEST INSTABILITY OVER THE FAR SOUTHEAST PLAINS. GIVEN THE INSTABILITY...TOUGH TO RULE OUT A TSRA OVER THE EASTERN MOUNTAINS AND PLAINS...AND WILL CONVERT -SHRA TO -TRSA FOR MOST OF THE AREA FOR THE AFTERNOON AND EVENING. FAR SOUTHEAST MAY EVEN SEE A CHANCE OF A STRONG STORM AS 0-6KM SHEAR IN THIS AREA IS AROUND 35 KNOTS. PRECIP WILL LINGER INTO THE EVENING...ESPECIALLY ON THE PLAINS...AS LOW LEVEL MOISTURE SLOSHES BACK WESTWARD BY MIDNIGHT...LEADING TO FAIRLY EXTENSIVE STRATUS OVER THE EASTERN MOUNTAINS AND PLAINS ONCE AGAIN. WILL LIKELY SEE SOME PATCHY FOG/DRIZZLE/LIGHT RAIN OVER THE PLAINS AFTER MIDNIGHT...AS SATURATED LAYER NEAR THE SURFACE GRADUALLY DEEPENS. WESTERN MOUNTAINS AND VALLEYS WILL MISS OUT ON MOST MOISTURE AND PRECIP...AS AIR MASS ALONG THE CONTINENTAL DIVIDE REMAINS VERY DRY. MAX TEMPS TODAY LIKELY WARMEST OVER THE SAN LUIS VALLEY...WHILE PLAINS STAY RATHER COOL WITH CLOUDS AND INCREASED MOISTURE. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 411 AM MDT THU MAY 23 2013 ...SEVERE WEATHER POSSIBLE FOR THE PLAINS FRIDAY... ...WARM WEEKEND AHEAD... MAIN CONCERN IN THE EXTENDED WILL BE THE POTENTIAL FOR SVR WX FRIDAY...GENERALLY E OF A LINE FROM KLIC TO KLHX TO KTAD. DEEP SWRLY FLOW AHEAD OF A TROUGH OVR THE W COAST AND PACNW WILL LEAD TO A STRENGTHENING LEE TROUGH AND SFC LOW OVR ERN CO BY FRI AFTERNOON. AS MENTIONED IN PREVIOUS AFDS...POSITION OF DRYLINE STILL NOT COMPLETELY CLEAR...BUT IT APPEARS LIKELY THAT MOISTURE WILL REMAIN OVR THE ERN PLAINS. SVR THREAT WILL BE HIGHEST LATE FRI AFTERNOON OVR PROWERS AND ERN KIOWA COUNTIES...WHERE CAPE OF AROUND 2000 J/KG...AND BULK SHEAR OF 40 KTS OR SO...ALONG WITH VEERING WIND PROFILES...WILL BE SUFFICIENT FOR SUPERCELL STORM STRUCTURES. MAIN THREAT WILL BE LARGE HAIL AND DAMAGING WINDS. TORNADO THREAT WILL PROBABLY BE LIMITED DUE TO HIGH TEMP-DEWPOINT SPREADS AND ASSOCIATED HIGH LCLS. OTHER STORY FOR THE COMING WEEK WILL BE THE VERY WARM TEMPS EXPECTED THROUGH THE MEMORIAL DAY WEEKEND. SHOULD SEE HIGH TEMPS BREAKING THE 90 DEGREE MARK OVR A GOOD PORTION OF THE PLAINS BOTH SAT AND SUN...AND POSSIBLY INTO MON IF A COLD FRONT HOLDS OFF TIL LATE IN THE DAY. STRENGTHENING SW FLOW AHEAD OF THE PERSISTENT WRN TROUGH WILL LEAD TO SOME FIRE WX CONCERNS OVR THE WEEKEND. PRECIP CHANCES WILL REMAIN LOW THROUGH THIS PERIOD AS THE DRYLINE PUSHES EWD INTO KS...BUT WILL STILL SEE THE DRYLINE FLIRT WITH THE CO-KS BORDER INTO EARLY NEXT WEEK. TUE THROUGH NEXT WEEK...SHOULD SEE POPS PICK UP A BIT AS THE TROUGH BEGINS TO EJECT INTO THE ROCKIES. LATEST ECMWF AND GFS BOTH ARE FAIRLY AMPLIFIED WITH THE UPPER LOW DIGGING INTO AZ AND NM IN THE TUE-THU TIME PERIOD. THIS SHOULD BRING INCREASED CHANCES OF SHOWERS AND STORMS...FOR THE MTS EARLY ON...AND THEN POSSIBLY MORE ACTION ALONG THE DRYLINE LATER IN THE WEEK. TEMPS WILL MODERATE TO NR SEASONAL AVERAGES. ROSE && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1107 AM MDT THU MAY 23 2013 MVFR TO LIFR STRATUS PERSISTENT OVER THE EASTERN MOUNTAINS AND PLAINS LATE THIS MORNING...WITH EVEN SOME POCKETS OF LIFR FOG AND DRIZZLE ACROSS NORTHERN PARTS OF EL PASO COUNTY. FOR KCOS AND KPUB...EXPECT AREAS OF MVFR TO LIFR CIGS AND VSBYS TO CONTINUE THROUGH 20-22Z...BEFORE CLOUDS GRADUALLY BREAK UP AND LIFT 22-00Z. THEN...EXPECT A FEW -SHRA AND -TSRA TO DEVELOP AFTER 22Z...CONTINUING UNTIL 04Z. OVERNIGHT...AREAS OF MVFR STRATUS WILL REDEVELOP AND COVER BOTH TERMINALS UNTIL MID-MORNING FRIDAY. AT KALS...EXPECT VFR CONDITIONS THROUGH TONIGHT. LW && .PUB WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING FOR COZ221-222-225>227. && $$ UPDATE...LW SHORT TERM...PETERSEN LONG TERM...ROSE AVIATION...LW |