Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 05/14/12


AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
956 PM MDT SUN MAY 13 2012 .UPDATE... UPDATED FORECAST TO DECREASE POPS ACROSS WESTERN AND NORTHERN PORTIONS OF THE FORECAST AREA. SCATTERED TO WIDESPREAD SHOWERS WITH EMBEDDED THUNDERSTORMS WILL CONTINUE ACROSS THE SOUTHEAST PLAINS THROUGH 06Z BEFORE DIMINISHING ACROSS MOST OF THE AREA BY 09Z. HRRR SEEMS TO HAVE A FAIR HANDLE ON THE PROGRESSION OF THE PCPN...AND HAVE FOLLOWED IT FOR POPS IN THE LATEST GRID UPDATE. -KT && .AVIATION... OUTFLOW BOUNDARIES FROM CONVECTION OUT EAST ARE HEADING WESTWARD TOWARDS KCOS AND KPUB...AND MAY BRING A BRIEF WIND SHIFT FROM AN EASTERLY DIRECTION TO BOTH TERMINALS BETWEEN 04 AND 06Z. THIS MAY HELP WITH SOME LOW STRATUS DEVELOPMENT AND WILL CONTINUE TO BE MONITORED TOWARDS THE 06Z TAF ISSUANCE. -KT && .PREV DISCUSSION... /ISSUED 242 PM MDT SUN MAY 13 2012/ SHORT TERM... (TONIGHT AND MONDAY) ..ONE LAST CHANCE AT GETTING SOME RAIN... UPPER LOW CENTER IS DROPPING SOUTH ACROSS WESTERN COLORADO CENTERED NEAR GRAND JUNCTION AT THE PRESENT TIME. LEFT FRONT QUADRANT ACTIVITY ASSOCIATED WITH 70 KNOT JETSTREAM MAXIMA MOVING BY TO THE SOUTH OF THE 4 CORNERS...IS TRIGGERING WIDESPREAD SHOWERS AND THUNDERSTORMS OVER THE SOUTHERN HALF OF THE FORECAST AREA. NORTHERN HALF OF THE FORECAST AREA IS BEING AFFECTED BY LIFT ASSOCIATED WITH UPPER LEVEL DIFFLUENT FLOW AND COLD POOL NEAR UPPER LOW CENTER. THE 2 FEATURES WILL COMBINE TO GIVE MUCH OF SOUTHERN COLORADO ANOTHER SHOT AT SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING... BEFORE EVERYTHING SHIFTS SOUTH INTO NEW MEXICO AFTER MIDNIGHT. SO FAR TODAY...THERE HAVE BEEN PEA TO HALF INCH SIZE HAIL REPORTS IN AN AND AROUND THE AREA. A BRIEFLY INTENSE PULSE STORM THAT DEVELOPED NEAR FLORISSANT EARLIER...HAD A 48 DBZ CORE UP TO ABOUT 34,000 FEET MSL...MINOR ROTATION...AND A VIL HITTING 30. AT THAT ELEVATION...IN THIS ENVIRONMENT...WITH A GOOD AMOUNT OF COLD AIR ALOFT...SOME QUARTER SIZE HAIL WAS CERTAINLY PLAUSIBLE. SAW THIS HAPPEN FROM A STORM 2 MILES EAST OF SOUTH FORK YESTERDAY. FOR THE REMAINDER OF THE EVENING...EXPECT SHOWERS AND THUNDERSTORMS TO SPREAD OFF OF THE MOUNTAINS ONTO THE PLAINS AND CONTINUE EASTWARD...PROBABLY WITH BETTER SUCCESS THAN LAST NIGHT. ATMOSPHERE IS A BIT LESS STABLE TODAY AND DEWPOINTS ARE NOW WIDESPREAD LOWER TO UPPER 40S ACROSS THE PLAINS. THIS SHOULD HELP THE SUCCESS OF THE EVENING CONVECTION ACROSS THE PLAINS. MOST ACTIVITY SHOULD SHIFT SOUTH INTO NEW MEXICO BY MIDNIGHT...WITH JUST SOME LINGERING ACTIVITY SOUTHERN AREAS PAST MIDNIGHT. COULD SEE SOME PATCHY GROUND FOG IN A LOT OF AREAS TOWARD MORNING AS SKIES START TO CLEAR. ONCE THE FOG GETS OUT OF HERE IN THE MORNING...WE SHOULD BE LOOKING AT A MOSTLY SUNNY DAY WITH VERY PLEASANT SEASONAL SPRING TEMPERATURES. STILL AN ISOLATED STORM CHANCE SOUTHERN MOUNTAIN AREAS...BUT LIKELY THE EXCEPTION...NOT THE RULE. THIS JUST IN...JUST HEARD FROM ONE OF OUR HAM RADIO COOPERATORS. APPARENTLY...THE CELL THAT WAS WARNED ON OVER TELLER COUNTY EARLIER DROPPED PEA SIZE HAIL...TO A 1 INCH DEPTH...IN A SWATH FROM THE LAKE GEORGE AREA EASTWARD THROUGH THE FLORISSANT CANYON...TO WITHIN 5 MILES OR SO WEST OF WOODLAND PARK. ALSO GOT A REPORT FROM ANOTHER SPOTTER 2 MILES NORTH OF WOODLAND PARK OF 1/2 DIAMETER HAIL IN THE PAST HOUR. SPRINGTIME IS FUN TIME IN THE ROCKIES. LW LONG TERM... (MONDAY NIGHT THROUGH NEXT SUNDAY) REST OF THE WEEK INTO NEXT WEEKEND LOOKS RELATIVELY BENIGN WITH GENERALLY ABOVE AVERAGE TEMPERATURES AND NO SIGNIFICANT STORMS ON THE HORIZON. TUESDAY...SHOULD BE WARM AND DRY AS AN UPPER RIDGE MOVES SEWD THROUGH CO. TEMPS SHOULD CLIMB INTO THE 80S OVR THE PLAINS...AND 50S-60S FOR THE MTN AREAS. BY WED...FIRST OF A COUPLE SHORT WAVES MOVES THROUGH FROM THE W. THE TROUGH AXIS LOOKS TO BE MOSTLY EA OF OUR AREA BY 00Z THU...AND BEST MID LEVEL WINDS AND FORCING LOOK TO BE FARTHER N...SO STRONGEST AFTERNOON OR EVE CONVECTION AT THIS POINT LOOKS TO BE MAINLY NE OF OUR CWA. HAVE INTRODUCED LOW POPS HOWEVER FOR THE ERN PLAINS IN THE LATE AFTERNOON AND EVENING HOURS. THERE IS JUST ENOUGH BULK SHEAR AND INSTABILITY THAT A COUPLE STRONG STORMS CANNOT BE RULED OUT. THE RIDGE REBUILDS THU INTO FRI...AND AGAIN IT SHOULD BE MOSTLY DRY BOTH DAYS FOR THE ENTIRE AREA...WITH TEMPS IN THE UPPR 80S TO POSSIBLY NR 90 DEGREES OVR THE PLAINS. NEXT DISTURBANCE MOVES IN LATE FRI INTO SAT...AND A COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL PUSH INTO ERN CO SOMETIME ON SAT. SOME POTENTIAL FOR STRONGER CONVECTION WITH THIS SYSTEM...AS DEEPER MOISTURE WITH HIGHER DEWPOINTS BEGINS TO SURGE WWD OVR THE PLAINS BY LATE IN THE DAY OR INTO SUN. NOT VERY CONFIDENT WITH THE MODEL SOLUTIONS FOR THE LATTER PART OF THE WEEKEND...AS THE GFS AND ECMWF CONTINUE TO BE OUT OF PHASE BEYOND SAT. 44 AVIATION... CATTERED THUNDERSTORMS HAVE DEVELOPED OVER THE HIGHER TERRAIN AND WILL SPREAD ONTO THE PLAINS THROUGH THE REMAINDER OF THE AFTERNOON INTO THE EVENING. WILL CONTINUE AT LEAST VCTS MENTION ALL TAF SITES THROUGH 02Z TIME PERIOD...WITH POTENTIAL FOR AT LEAST BRIEF MVFR CONDITIONS UNDER A FEW OF THE STRONGER STORMS. MAINLY VFR CONDITIONS SPREADING FROM NORTH TO SOUTH 03Z-06Z TIME FRAME AS TSRA MOVE INTO NM...THOUGH DUE TO RECENT PRECIPITATION AND LIGHT WINDS...WILL HAVE TO WATCH FOR PATCHY GROUND FOG DEVELOPMENT AROUND SUNRISE MONDAY... ESPECIALLY AT KALS AND KPUB. LW && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31/13
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1204 PM MDT SAT MAY 12 2012 .UPDATE... ISSUED AT 1203 PM MDT SAT MAY 12 2012 A BATTLE BETWEEN THE DRY AIR ALOFT AND THE CONDITIONALLY UNSTABLE AIR MASS BENEATH THE SUBSIDENT LAYER. THE SUBSIDENT LAYER IS NOT THAT STRONG BUT NEITHER IS THE CONVECTIVE POTENTIAL. BUILDING CUMULUS HAS FIRED OVER THE WESTERN SLOPE HIGH TERRAIN BUT NOT A SINGLE LIGHTNING STRIKE AS OF 1745Z. DO EXPECT THUNDERSTORMS WITH THE BEST POTENTIAL OVER THE SAN JUANS AND TOWARD THE DIVIDE. BUT LESSER ACTIVITY FARTHER WEST AND NO STORMS EXPECTED OVER ERN UTAH (EXCEPT FOR A POSSIBLE LATE DAY STORM OVER THE ERN UINTAS). GRIDS HAVE BEEN UPDATED TO REFLECT THIS CURRENT THINKING. CONSIDERATION FOR SUNDAY...CLOSED LOW CIRCULATION WILL BE MOVING NORTH TO SOUTH. THE NAM SHOWS A TIGHTER CLOSED LOW CIRCULATION BUT MOISTURE IS LACKING. WILL TAKE A CLOSER EXAMINATION BEFORE THE MID AFTERNOON FORECAST UPDATE. UPDATE ISSUED AT 754 AM MDT SAT MAY 12 2012 STRATUS SHROUDS THE UPPER GUNNISON VALLEY THIS MORNING...COVERS BLUE MESA RESERVOIR AND THE TOWN OF GUNNISON. THESE STRATIFORM CLOUDS WILL LIFT AND DISSIPATE LATER THIS MORNING...THE TEMPERATURE AND DEW POINT SPREAD OF 7F AT KGUC SUGGESTS THIS WILL BE SOONER THAN LATER. THE HRRR SHOWS CONVECTIVE SHOWERS DEVELOPING OVER THE SAN JUAN MOUNTAINS...BUT NOTABLY DRY OVER THE NORTHERN AND CENTRAL MOUNTAINS THIS AFTERNOON. MUCH OF THE FORECAST AREA IS IN A DRY AND SUBSIDENT AIR MASS THIS MORNING...BUT THIS IS ONLY TEMPORARY AS THE NEXT UPSTREAM SHORT WAVE WILL BE APPROACHING FROM THE NORTHWEST THIS AFTERNOON. THE FORECAST MAY BE TOO FAST WITH SHOWERS AND STORMS REDEVELOPING OVER THE NORTHERN MOUNTAINS...WE WILL TAKE A LOOK AT THE MODEL SUITE TO CHECK WHETHER OTHER MODELS SHOW THIS SAME TREND. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 311 AM MDT SAT MAY 12 2012 NEXT UPSTREAM PACIFIC SHORTWAVE TROUGH APPARENT ON SATELLITE IMAGERY IN SOUTHERN IDAHO. AHEAD OF THAT FEATURE...EXPECT CONVECTION TO DEVELOP AGAIN OVER OUR CWA THIS AFTERNOON MAINLY NEAR THE CONTINENTAL DIVIDE...THOUGH NOT AS EXTENSIVE AS ON FRIDAY. MAX TEMPERATURES TODAY LIKELY TO BE A TAD COOLER ACROSS THE SOUTHERN THIRD OF OUR CWA...AND SIMILAR TO YESTERDAY ACROSS THE REMAINDER OF OUR CWA. THE 00Z NAM HAS COME IN STRONGER WITH THE SHORTWAVE TROUGH THAT IS PROGGED TO DROP SOUTHWARD ACROSS WY SAT NIGHT...AND THEN PROCEED ACROSS CO/EASTERN UT ON SUNDAY. THIS SOLUTION IS IN BETTER AGREEMENT WITH THE GFS THAN THE PREVIOUS RUN. AND BOTH MODELS NOW SEEM TO BE JUST A LITTLE SLOWER IN MOVING THE SYSTEM SOUTHWARD INTO NM... KEEPING IT OVER AND JUST SOUTH OF OUR SOUTHERN EDGE THROUGH SUN EVENING. EXPECT SCATTERED SHOWERS WILL CONTINUE THROUGH SAT NIGHT AS THIS SHORTWAVE APPROACHES...MAINLY OVER THE EASTERN MOUNTAINS. THEN BY SUNDAY THE TROUGH WILL MOVE OVERHEAD FOR AN UPTICK OF ACTIVITY THROUGH THE DAY AND INTO THE EVENING. WHILE THE EASTERN MOUNTAINS WILL CONTINUE TO BE FAVORED...WILL EXPAND COVERAGE WESTWARD SOMEWHAT AS THE NAM SHOWS THE 500 MB LOW DROPPING ALONG THE UT/CO BORDER THROUGH THE DAY. AN EASTERLY OR DOWNSLOPE COMPONENT QUICKLY FOLLOWS WITH DIMINISHING ACTIVITY FROM THE NORTH BEGINNING BEFORE SUNSET AS THE TROUGH AXIS MOVES INTO NM. SHOWERS WILL LINGER LONGEST OVER THE SOUTHERN DIVIDE. HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND WEST LATE SUN NIGHT INTO MONDAY. BY MONDAY AFTERNOON THE HIGH PRESSURE RIDGE WILL BE JUST UPSTREAM...CENTERED OVER UT WITH DRIER AND WARMER CONDITIONS FOR OUR CWA. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 311 AM MDT SAT MAY 12 2012 MIGRATORY UPPER RIDGE SHOULD BE MOVING ACROSS OUR CWA MONDAY NIGHT AND TUESDAY WITH RELATIVELY DRY CONDITIONS EXCEPT FOR ISOLATED CONVECTION OVER THE MOUNTAINS. THEN A PACIFIC SHORTWAVE DISTURBANCE IS STILL EXPECTED TO DRIFT ACROSS OUR AREA ON WEDNESDAY...FOLLOWED BY ANOTHER DISTURBANCE ON THURSDAY... WHICH SHOULD RESULT IN A FEW SHOWERS AND THUNDERSTORMS MAINLY OVER THE MOUNTAINS. THESE FEATURES SHOULD HAVE MINIMAL IMPACT ON TEMPERATURES...EXCEPT FOR THE INFLUENCE OF ANY CLOUD COVER. AN INCREASING SW FLOW ALOFT IS STILL EXPECTED OVER OUR CWA ON FRIDAY AS THE MODELS ARE INDICATING A MORE SIGNIFICANT SHORTWAVE TROUGH APPROACHING OUR CWA. PRESENTLY...NEXT FRIDAY APPEARS TO BE A RATHER DRY DAY FOR OUR CWA WITH BREEZY SOUTHERLY SURFACE WINDS. MAX TEMPERATURES DURING THIS PERIOD SHOULD BE NEARLY 10 DEGREES ABOVE NORMAL AT MOST LOCATIONS...WITH MIN TEMPERATURES 5 TO 10 DEGREES ABOVE NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1203 PM MDT SAT MAY 12 2012 THE MAIN AVIATION HAZARD WILL BE CONVECTIVE STORMS AND GUSTY OUTFLOW WINDS. SHOWERS WITH EMBEDDED THUNDERSTORMS WILL HUG THE HIGHER TERRAIN...BUT A PASSING SHORT LIVED STORM WILL BE IN THE VICINITY OF KEGE AND KASE. KRIL...KMTJ...AND KGJT COULD EXPERIENCE GUSTY OUTFLOW WINDS FROM DISTANT STORMS. NO THUNDERSTORMS ARE EXPECTED OVER ERN UTAH EXCEPT FOR A LATE DAY STORM OVER THE ERN UINTA MOUNTAINS. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATE...PF SHORT TERM...EH LONG TERM...JRP AVIATION...PF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
754 AM MDT SAT MAY 12 2012 .UPDATE... ISSUED AT 754 AM MDT SAT MAY 12 2012 STRATUS SHROUDS THE UPPER GUNNISON VALLEY THIS MORNING...COVERS BLUE MESA RESERVOIR AND THE TOWN OF GUNNISON. THESE STRATIFORM CLOUDS WILL LIFT AND DISSIPATE LATER THIS MORNING...THE TEMPERATURE AND DEW POINT SPREAD OF 7F AT KGUC SUGGESTS THIS WILL BE SOONER THAN LATER. THE HRRR SHOWS CONVECTIVE SHOWERS DEVELOPING OVER THE SAN JUAN MOUNTAINS...BUT NOTABLY DRY OVER THE NORTHERN AND CENTRAL MOUNTAINS THIS AFTERNOON. MUCH OF THE FORECAST AREA IS IN A DRY AND SUBSIDENT AIR MASS THIS MORNING...BUT THIS IS ONLY TEMPORARY AS THE NEXT UPSTREAM SHORT WAVE WILL BE APPROACHING FROM THE NORTHWEST THIS AFTERNOON. THE FORECAST MAY BE TOO FAST WITH SHOWERS AND STORMS REDEVELOPING OVER THE NORTHERN MOUNTAINS...WE WILL TAKE A LOOK AT THE MODEL SUITE TO CHECK WHETHER OTHER MODELS SHOW THIS SAME TREND. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 311 AM MDT SAT MAY 12 2012 NEXT UPSTREAM PACIFIC SHORTWAVE TROUGH APPARENT ON SATELLITE IMAGERY IN SOUTHERN IDAHO. AHEAD OF THAT FEATURE...EXPECT CONVECTION TO DEVELOP AGAIN OVER OUR CWA THIS AFTERNOON MAINLY NEAR THE CONTINENTAL DIVIDE...THOUGH NOT AS EXTENSIVE AS ON FRIDAY. MAX TEMPERATURES TODAY LIKELY TO BE A TAD COOLER ACROSS THE SOUTHERN THIRD OF OUR CWA...AND SIMILAR TO YESTERDAY ACROSS THE REMAINDER OF OUR CWA. THE 00Z NAM HAS COME IN STRONGER WITH THE SHORTWAVE TROUGH THAT IS PROGGED TO DROP SOUTHWARD ACROSS WY SAT NIGHT...AND THEN PROCEED ACROSS CO/EASTERN UT ON SUNDAY. THIS SOLUTION IS IN BETTER AGREEMENT WITH THE GFS THAN THE PREVIOUS RUN. AND BOTH MODELS NOW SEEM TO BE JUST A LITTLE SLOWER IN MOVING THE SYSTEM SOUTHWARD INTO NM... KEEPING IT OVER AND JUST SOUTH OF OUR SOUTHERN EDGE THROUGH SUN EVENING. EXPECT SCATTERED SHOWERS WILL CONTINUE THROUGH SAT NIGHT AS THIS SHORTWAVE APPROACHES...MAINLY OVER THE EASTERN MOUNTAINS. THEN BY SUNDAY THE TROUGH WILL MOVE OVERHEAD FOR AN UPTICK OF ACTIVITY THROUGH THE DAY AND INTO THE EVENING. WHILE THE EASTERN MOUNTAINS WILL CONTINUE TO BE FAVORED...WILL EXPAND COVERAGE WESTWARD SOMEWHAT AS THE NAM SHOWS THE 500 MB LOW DROPPING ALONG THE UT/CO BORDER THROUGH THE DAY. AN EASTERLY OR DOWNSLOPE COMPONENT QUICKLY FOLLOWS WITH DIMINISHING ACTIVITY FROM THE NORTH BEGINNING BEFORE SUNSET AS THE TROUGH AXIS MOVES INTO NM. SHOWERS WILL LINGER LONGEST OVER THE SOUTHERN DIVIDE. HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND WEST LATE SUN NIGHT INTO MONDAY. BY MONDAY AFTERNOON THE HIGH PRESSURE RIDGE WILL BE JUST UPSTREAM...CENTERED OVER UT WITH DRIER AND WARMER CONDITIONS FOR OUR CWA. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 311 AM MDT SAT MAY 12 2012 MIGRATORY UPPER RIDGE SHOULD BE MOVING ACROSS OUR CWA MONDAY NIGHT AND TUESDAY WITH RELATIVELY DRY CONDITIONS EXCEPT FOR ISOLATED CONVECTION OVER THE MOUNTAINS. THEN A PACIFIC SHORTWAVE DISTURBANCE IS STILL EXPECTED TO DRIFT ACROSS OUR AREA ON WEDNESDAY...FOLLOWED BY ANOTHER DISTURBANCE ON THURSDAY... WHICH SHOULD RESULT IN A FEW SHOWERS AND THUNDERSTORMS MAINLY OVER THE MOUNTAINS. THESE FEATURES SHOULD HAVE MINIMAL IMPACT ON TEMPERATURES...EXCEPT FOR THE INFLUENCE OF ANY CLOUD COVER. AN INCREASING SW FLOW ALOFT IS STILL EXPECTED OVER OUR CWA ON FRIDAY AS THE MODELS ARE INDICATING A MORE SIGNIFICANT SHORTWAVE TROUGH APPROACHING OUR CWA. PRESENTLY...NEXT FRIDAY APPEARS TO BE A RATHER DRY DAY FOR OUR CWA WITH BREEZY SOUTHERLY SURFACE WINDS. MAX TEMPERATURES DURING THIS PERIOD SHOULD BE NEARLY 10 DEGREES ABOVE NORMAL AT MOST LOCATIONS...WITH MIN TEMPERATURES 5 TO 10 DEGREES ABOVE NORMAL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 311 AM MDT SAT MAY 12 2012 EXPECT VFR CONDITIONS ACROSS MOST OF THE AREA TODAY AND TONIGHT...EXCEPT FOR SOME EARLY MORNING LOW CLOUDS AND MOUNTAIN OBSCURATION IN THE EXTREME SOUTHERN PART OF WESTERN CO NEAR THE CONTINENTAL DIVIDE. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON MAINLY OVER THE MOUNTAINS OF WESTERN COLORADO WITH LOCALIZED MOUNTAIN OBSCURATION/MVFR CIGS. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATE...PF SHORT TERM...EH LONG TERM...JRP AVIATION...JRP
AREA FORECAST DISCUSSION
NWS NEW YORK NY
855 PM EDT SUN MAY 13 2012 .SYNOPSIS... A COLD FRONT APPROACHES THE NORTHEAST TONIGHT...AND BECOMES NEARLY STATIONARY JUST WEST OF THE AREA. A WEAK...BROAD AREA OF LOW PRESSURE SLOWLY MOVES NORTHEAST FROM THE SOUTHEASTERN STATES STARTING MONDAY...MOVING OVER THE REGION BY WEDNESDAY MORNING. A COLD FRONT THEN MOVES INTO FAR WESTERN PORTIONS OF THE TRI-STATE BY LATE WEDNESDAY...THEN CROSSES THE REMAINDER OF THE TRI-STATE WEDNESDAY NIGHT. HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES FROM THURSDAY INTO FRIDAY...THEN SLIDES INTO THE CANADIAN MARITIMES...WHERE IT DOMINATES OUR WEATHER INTO SUNDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... RECENT RADAR TRENDS...AND 15Z SREF/18Z NAM/LATEST HRRR ALL SUGGEST REGION SHOULD REMAIN DRY THROUGH MIDNIGHT...SO HAVE ADJUSTED FORECAST ACCORDINGLY. MAINLY SCT-ISOLD -SHRA SHOULD DEVELOP AFTER MIDNIGHT IN RESPONSE TO APPROACH OF A FAIRLY STRONG 700-500 HPA SHORTWAVE...WITH FORCING ENHANCED WITH THE DEPARTURE OF A VORTICITY MINIMUM AHEAD OF IT. WILL ALSO BE IN THE RIGHT REAR QUADRANT OF AN 80+ KT 300 HPA JET STREAK...WHICH WILL SUPPLY SOME ADDITIONAL FORCING OVERNIGHT. BEST FORCING WILL BE OVER FAR NW ZONES...SO HAVE THE HIGHEST POPS THERE OVERNIGHT - LOW END LIKELY AND ONLY LOW END SLIGHT CHANCE POPS OVER FAR SE ZONES. THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE OVERNIGHT LOWS REMAINING WELL ABOVE NORMAL...WITH 925MB TEMPS NEARING 15 DEGREES CELSIUS. SHOULD SEE LOWS MAINLY IN THE MID TO UPPER 50S...WITH LOWER 60S IN NYC. THIS IS CONSISTENT WITH A BLEND OF 2/3 MAV/MET GUIDANCE AND 1/3 NAM 2-METER TEMPERATURE. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... PRECIP TIMING AND INTENSITY REMAINS THE QUESTION FOR THIS PERIOD AS THE FRONT REMAINS NEARLY STATIONARY OVER CENTRAL NY AND STRONG HIGH PRESSURE REMAINS SETTLED OVER THE NORTH ATLANTIC. WITH THE BROAD UPPER LEVEL TROUGH PERSISTING...A VORT MAX LOOKS TO TRAVERSE THE REGION SOMETIME BETWEEN 12Z AND 18Z MON...BRINGING ENOUGH FORCING THAT WILL ASSIST IN TRIGGERING SCT SHOWERS. WITH LITTLE TO NO INSTABILITY EXPECTED...ANY PRECIP SHOULD REMAIN JUST SHOWERS. THE MODELS DEVELOP A BROAD SURFACE LOW MONDAY AND BRING IT NORTH ALONG THE FRONT. AS THIS LOW APPROACHES...IT SHOULD GENERATE A STRONG SOUTH TO SOUTH SOUTHEAST FLOW...INCREASING THE ISENTROPIC LIFT...RESULTING IN MORE RAIN SHOWERS. HAVE THEREFORE KEPT CHANCE TO LIKELY POPS OVER THE WESTERN HALF OF THE CWA WITH THE BETTER FORCING...AND SLIGHT CHANCE TO CHANCE IN THE MORE STABLE EASTERN HALF. THE SOUTHERLY FLOW WILL FINALLY MOISTEN UP THE LOWER LEVELS...SO EXPECTING BKN TO OVC SKIES WITH SOME LOWER CLOUDS MOVING IN. THE OVC SKIES...ALONG WITH ANY PRECIP...AND 925MB TEMPS REMAINING NEAR 12 DEGREES...EXPECTING MUCH COOLER TEMPS MON AND MON NIGHT...ESP ALONG THE COAST WHERE AN ONSHORE FLOW WILL GENERATE HIGHS ONLY IN THE 60S. && .LONG TERM /TUESDAY THROUGH SUNDAY/... THERE IS QUITE A BIT OF MODEL SPREAD AS TO WHO MUCH IF ANY PRECIPITATION THE REGION RECEIVES ON TUESDAY...WITH THE NAM BEING BASICALLY DRY AND THE ECMWF BEING THE WETTEST AND FARTHEST EAST. GIVEN THE BLOCKING PATTERN SET UP OVER THE NORTHERN STREAM AND THE STRENGTH OF THE HIGH TO THE EAST...DO NOT WANT TO COMPLETELY DISCOUNT THE NAM SOLUTION. SO WENT WITH LIKELY POPS OVER FAR NW ZONES TO SLIGHT CHANCE POPS OVER FAR SE ZONES. THIS IS ALSO CONSISTENT WITH ALL MODELS HAVING THE BEST DYNAMICS WITH A 700-500 HPA SHORTWAVE TROUGH THAT LIFTS NE THROUGH THE REGION PASS MAINLY TO THE NW OF THE CWA. WITH MINIMAL CAPE...THE THETA-E RIDGE FORECAST TO STAY TO OUR WEST...AND WEAK INSTABILITY ALOFT...HAVE KEPT THUNDER OUT OF THE FORECAST FOR TUESDAY. FOR HIGHS TUESDAY USED A BLEND OF 4/5 MAV/MET/MIX FROM 950 NEAR THE COAST/MIX FROM 900 ACROSS THE INTERIOR AND 1/5 NAM 2-METER TEMPERATURES. THIS YIELDS VALUES NEAR NORMAL. TUESDAY NIGHT BRINGS THE BEST CHANCE FOR HEAVY PRECIPITATION TO THE REGION WITH STRONG ISENTROPIC LIFT FROM THE I-295 TO I-305 SURFACES...A PASSING 700-500 HPA SHORTWAVE AND THE REGION BEING IN THE RIGHT REAR QUADRANT OF A 80+ KT 300 HPA JET. SO HAVE LIKELY POPS...WITH A SLIGHT CHANCE OF THUNDER...WITH SHOWALTER INDICES PROGGED AROUND ZERO. FOR LOWS TUESDAY NIGHT USED A BLEND OF 2/3 MET/MAV AND 1/3 NAM 2-METER TEMPERATURES. THIS YIELDED VALUES AROUND 5 DEGREES ABOVE NORMAL. HAVE LIKELY POPS E WEDNESDAY MORNING AS THE SURFACE WAVE SLOWLY MOVES OUT...THIS WILL TAKE THE CORE OF THE LOW LEVEL MOISTURE WITH IT...LEAVING NOT MUCH BEHIND FOR THE APPROACHING COLD FRONT AND FAIRLY STRONG 700-500 HPA SHORTWAVE PASSING ACROSS THE REGION TO ACT ON. SO HAVE POPS IN THE AFTERNOON RANGING FROM SLIGHT CHANCE FAR NW TO CHANCE ELSEWHERE. DO HAVE A SLIGHT CHANCE OF THUNDER...WITH CAPES GENERALLY FROM 250-750 J/KG...SHOWALTER INDICES AS LOW AS -2...THE LOW LEVEL THETA-E RIDGE OVER THE REGION...AND CONTINUATION OF BEING IN THE RIGHT REAR QUADRANT OF AN 80+ KT 300 HPA JET. FOR HIGHS WEDNESDAY BLENDED MEX/MEX MEAN GUIDANCE AND NAM 2-METER TEMPERATURES...WITH A MIX DOWN FROM 925 HPA ACROSS THE INTERIOR AND 975 HPA AT THE COAST. THIS YIELDS VALUES 3-5 DEGREES ABOVE NORMAL. OTHER THAN A CHANCE TO SLIGHT CHANCE OF SHOWERS EARLY...WEDNESDAY NIGHT SHOULD BE DRY AS THE 700-500 HPA TROUGH AXIS SLIDES TO OUR EAST. MODEL DIFFERENCE IN THE EXTENDED WITH THE ECMWF FEATURING WNW-NW FLOW ALOFT AND THE GFS MORE ZONAL FLOW. THE ECMWF IS ALSO MORE ROBUST WITH ITS HANDLING OF A COASTAL LOW FORECAST TO DEVELOP OFF THE SE COAST BY FRIDAY MORNING. THE GFS TAKES THIS SYSTEM OFF WELL TO OUR EAST THEN NE...WHILE THE ECMWF HAS IT MEANDER OFF THE CAROLINA COAST. THIS SYSTEM COULD ULTIMATELY END UP PLAYING A ROLE IN OUR WEATHER...SO WILL HAVE TO CONTINUE TO MONITOR. FOR NOW...WITH HIGH PRESSURE THE MAIN PLAYER AT THE SURFACE...OTHER THAN POSSIBLY A BACKDOOR COLD FRONT OR TWO...WENT WITH A DRY FORECAST THURSDAY-SUNDAY. FOR TEMPERATURES USED A BLEND OF MEX/MEX ENSEMBLE MEAN GUIDANCE WITH HPC GUIDANCE. THIS YIELDED ABOVE NORMAL HIGHS AND LOWS NEAR TO SLIGHTLY ABOVE NORMAL. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... TERMINALS REMAIN NESTLED BETWEEN HIGH PRESSURE OFFSHORE AND A SLOW MOVING COLD FRONT ACROSS NORTHERN/WESTERN NY STATE...WHILE A WEAK TROF RESIDES CLOSE TO THE AREA. THIS GENERAL SCENARIO SHOULD NOT CHANGE MUCH OVER THE NEXT 24 HR...WHILE UPPER LEVEL DISTURBANCES MOVE ACROSS AND CREATE OPPORTUNITIES FOR LOWER CIGS AND SHOWERS LATE TONIGHT INTO MON MORNING...AND AGAIN MON AFTERNOON. CONFIDENCE IN SHOWERS ACTUALLY OCCURRING IS HIGH ENOUGH TO AT LEAST MENTION...BUT EXACT TIMING IS STILL SOMEWHAT IN QUESTION. CONDITIONS SHOULD BE MOSTLY VFR...BUT AFTERNOON SHOWERS AT KSWF LOOK MORE LIKELY TO BRING MVFR CONDITIONS. SOUTHERLY SEA BREEZES WILL DIMINISH EARLY...AND WINDS ACROSS THE BOARD MAY VEER A LITTLE MORE SW THIS EVENING. WEAKER SEA BREEZE DEVELOPMENT THAN THAT OF TODAY EXPECTED MON AFTERNOON. OUTLOOK FOR 00Z TUE THROUGH FRI... .MON NIGHT-WED...MVFR OR LOWER CONDITIONS POSSIBLE IN SHOWERS. ISOLD THUNDER POSSIBLE TUE NIGHT-WED. .WED NIGHT-FRI...VFR. && .MARINE... MINOR CHANGES IN THE NEAR TERM TO REFLECT THE LATEST TRENDS IN OBSERVATIONS AND GUIDANCE. THE MAIN CHANGE WAS TO REMOVE ALL MENTION OF PRECIPITATION PRIOR TO MIDNIGHT TONIGHT. WINDS WILL INCREASE TONIGHT AS THE COLD FRONT APPROACHES THE COAST...PRODUCING A SOUTHERLY FLOW WITH GUSTS UP TO AROUND 20 KT. HOWEVER...WITH THE PERSISTENT SOUTHERLY FLOW...UP TO 5 FT SEAS ARE EXPECTED OVER THE EASTERN TWO COASTAL OCEAN ZONES...SO HAVE CONTINUED THE SCA FOR HAZARDOUS SEAS INTO MONDAY. DEPENDING ON WHETHER THE CONDITIONS ARE MET...MAY NEED TO CONTINUE INTO MONDAY NIGHT AS WELL. ALL OTHER WATERS SHOULD REMAIN BELOW SCA CRITERIA THROUGH MONDAY NIGHT. WINDS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY TUESDAY-FRIDAY...AS THE PRESSURE GRADIENT AND WINDS IN THE LOW LEVELS SUPPORT ONLY WINDS OF AT MOST 10-15KT WITH GUSTS OF AT MOST 20 KT. HOWEVER...A PERSISTENT ONSHORE FLOW FROM TUESDAY INTO WEDNESDAY NIGHT WILL KEEP SEAS AT HAZARDOUS LEVELS ON ALL THE COASTAL OCEAN ZONES...AND POSSIBLY INTO THURSDAY ON THE WATERS EAST OF MORICHES INLET. && .HYDROLOGY... THERE WILL BE THE POTENTIAL BETWEEN 1 AND 3 INCHES WITH THE PRECIP EXPECTED TONIGHT THROUGH INTO WEDNESDAY EVENING. TONIGHT/S AMOUNTS SHOULD REMAIN LESS THAN A TENTH...WITH THE AMOUNTS PICKING UP MONDAY DURING THE DAY WITH BETWEEN A QUARTER AND THREE QUARTERS INCH POSSIBLE THROUGH MONDAY NIGHT. THE HEAVIEST PRECIP IS EXPECTED FROM LATE TUESDAY INTO WEDNESDAY MORNING...WITH BETWEEN 1 AND 2 INCHES POSSIBLE OVER THE LOWER HUDSON RIVER VALLEY AND NORTHEASTERN NJ...AND HALF AN INCH TO AN INCH OVER CT...LONG ISLAND...AND THE NYC METRO AREA. DUE TO ANTECEDENT DRY CONDITIONS...THERE IS INITIALLY A HIGHER PROBABILITY OF MINOR URBAN FLOODING THAN MINOR SMALL STREAM FLOODING...BUT WILL HAVE TO MONITOR FOR TRAINING SHOWER/TSTM ACTIVITY ACROSS NE NJ AND THE LOWER HUDSON VALLEY MONDAY NIGHT INTO WEDNESDAY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT MONDAY FOR ANZ350. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON EDT MONDAY FOR ANZ353. && $$ SYNOPSIS...MALOIT/SEARS NEAR TERM...MALOIT SHORT TERM...SEARS LONG TERM...MALOIT AVIATION...GOODMAN MARINE...MALOIT/SEARS HYDROLOGY...MALOIT/SEARS
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
359 PM EDT SAT MAY 12 2012 .SHORT TERM /TONIGHT THROUGH MONDAY/... MAIN FORECAST CONCERN WILL BE QPF AND POPS ASSOCIATED WITH DEVELOPING LOW PRESSURE SYSTEM APPROACHING THE FORECAST AREA FROM THE WEST. MODELS ARE GENERALLY IN GOOD AGREEMENT WITH THIS FEATURE HOWEVER THE GFS SEEMS TO HAVE A SLIGHTLY BETTER HANDLE ON IT AND THE ASSOCIATED PRECIPITATION...THEREFORE MADE MINOR TWEAKES TO MAV INITIALIZATION. HRRR IS SUGGESTING SOME SCATTERED SHOWER DEVELOPMENT AHEAD OF THE MAIN SWATH AFTER 21Z THIS EVENING... WHILE THE MORE WIDESPREAD RAIN SHOULD AFFECT THE WESTERN PORTIONS AFTER ABOUT 03Z. HAVE THEREFORE KEPT CHANCE POPS THIS AFTERNOON AND INCREASED TO LIKELY AND CATEGORICAL POPS ACROSS THE NORTHWESTERN HALF OF THE AREA OVERNIGHT. SOME BREAKS IN THE CLOUD DECK THIS AFTERNOON HAS ALLOWED CAPE VALUES TO INCREASE SOMEWHAT SO THERE IS STILL A SLIGHT CHANCE FOR THUNDERSTORMS. SUNDAY LOOKS TO BE THE WETTEST DAY IN THE SHORT TERM WITH THE HEAVIEST RAINFALL LIKELY OCCURRING IN THE NORTHERN PORTIONS OF THE AREA DURING THE MORNING AND SUNDAY OVERNIGHT. LATEST 12Z GFS AND NAM TIME HEIGHTS ALSO SHOW DEEPEST HIGH RH LAYER INFLUENCING THE AREA ON SUNDAY WITH LESS MOISTURE ON MONDAY THAN PREVIOUSLY THOUGHT. HAVE THEREFORE MAINTAINED CATEGORICAL POPS IN THE NORTH... LIKELY POPS CENTRAL... AND HIGH END CHANCE POPS SOUTH THROUGH SUNDAY. MODELS DO INDICATED A BIT HIGHER CAPE VALUES AFTER 18Z SUNDAY SO HAVE INCLUDED CHANCE OF THUNDERSTORMS. THE UPPER LEVEL SHORTWAVE TROUGH AXIS SHOULD SWING THROUGH THE AREA BY AROUND 18Z MONDAY AND THE WEAK COLD FRONT ASSOCIATED WITH THE PHASED SURFACE LOW SHOULD PASS AROUND 00Z TUESDAY...THUS ALLOWING FOR CHANCE POPS TO CONTINUE THROUGH MUCH OF THE DAY. LESS QPF IS EXPECTED DURING THIS TIME HOWEVER. FOR TOTAL QPF...HPC GUIDANCE IS OVERALL LEANING MORE TOWARD GFS AMOUNTS GIVING 48 HOUR RAINFALL TOTALS OF NEAR 2.5 INCHES IN THE NORTH TO HALF AN INCH IN THE SOUTHEAST BY 00Z TUESDAY. THE HEAVIEST OF WHICH SHOULD OCCUR SUNDAY MORNING AND SUNDAY OVERNIGHT. FOR TEMPS...MAV GUIDANCE SEEMS TO HAVE BEEN DOING WELL WITH PROGGED HIGHS AND LOWS SO MADE ONLY MINOR TWEAKS. MONDAY LOOKS TO BE A BIT WARMER THAN TUESDAY WITH HIGHS IN THE MID TO UPPER 70S NORTH AND LOW TO MID 80S SOUTH. 03 && .LONG TERM /TUESDAY THROUGH SATURDAY/... MODELS CONTINUE TO HOLD A BROAD TROUGH ACROSS THE SOUTHEAST THROUGH THE PERIOD. LOW PRESSURE DEVELOPING IN THE CENTRAL GULF SHOULD BE INTO THE WESTERN CAROLINAS AT THE BEGINNING OF THE PERIOD...WITH MOST OF THE RAINFALL EAST OF THE CWA. HAVE HELD ON TO LOW POPS ACROSS THE EASTERN ZONES INTO WEDNESDAY NIGHT. SOME QUESTION AS TO HOW MUCH MOISTURE LINGERS BEHIND THIS SYSTEM AS MODELS HOLD THE BROAD UPPER TROUGH ACROSS THE SOUTHEAST AND REMNANTS OF THE SURFACE FRONT DRIFT ACROSS CENTRAL OR SOUTH GEORGIA. HAVE NOT ADDED ANY POPS TO THE LAST FEW DAYS DUE TO LOW CONFIDENCE IN THE MODEL SOLUTION. 41 && HYDROLOGY... /ISSUED 330 PM EDT SAT MAY 12 2012/ HPC 1-3 DAY QPF TOTAL ENDING 12Z TUESDAY SHOWS 2.5 TO 3.00 ACROSS EXTREME NORTH GEORGIA AND LESSER AMOUNTS ELSEWHERE. 6 HOUR FFG VALUES ARE AROUND 4.5 INCHES OVER THE NORTH. WITH EXPECTED RAINFALL SPREAD OVER A COUPLE OF DAYS...THINK WE SHOULD BE ABLE TO HANDLE THESE FORECAST AMOUNTS...BUT WILL HAVE TO WATCH FOR LOCALIZED PROBLEMS ON THE CREEKS AND RIVERS ACROSS THE NORTH. 41 AVIATION... 18Z UPDATE... CIGS HAVE BEEN BOUNCING BETWEEN VFR AND MVFR THIS AFTERNOON... HOWEVER SITES SHOULD STAY AT VFR LEVELS FOR THE MOST PART. WINDS SHOULD REMAIN SOUTHEASTERLY THROUGH THE FORECAST PERIOD AND MOST SITES SHOULD HAVE GUSTS THIS AFTERNOON STAYING UNDER 20KTS. AFTER 21Z THIS EVENING LOCATIONS EXCEPT FOR KMCN A BIT LATER SHOULD BEGIN TO HAVE -SHRA WITH CONTINUED CHANCES THROUGH THE PERIOD. CIGS LOOK TO LOWER TO MVFR LEVELS WITH 0VC020 BY 03Z AND IFR WITH 0VC007 ALONG WITH VISBYS AROUND 4SM BY 10Z SUNDAY. INTRODUCED -TSRA FOR KATL AFTER 18Z SUNDAY. //ATL CONFIDENCE...18Z UPDATE... HIGH. 03 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 59 73 62 79 / 50 70 60 50 ATLANTA 62 73 63 77 / 70 80 50 40 BLAIRSVILLE 57 65 59 74 / 60 80 80 50 CARTERSVILLE 63 71 63 77 / 80 80 70 40 COLUMBUS 65 79 65 81 / 70 60 50 40 GAINESVILLE 59 70 62 77 / 60 80 80 50 MACON 61 79 63 82 / 50 50 50 50 ROME 63 75 62 80 / 80 80 60 40 PEACHTREE CITY 60 75 60 78 / 70 80 50 40 VIDALIA 66 81 67 84 / 30 50 50 50 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BAKER LONG TERM....41 AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1156 PM CDT FRI MAY 11 2012 .SHORT TERM /TONIGHT/... THE COLD FRONT WAS ALONG A NEWTON TO LAMONI LINE AT 20Z THIS AFTERNOON. VISIBLE SATELLITE IMAGERY WAS SHOWING A FEW CU DEVELOPING NEAR THE BOUNDARY. SURFACE DEW POINTS ALONG AND AHEAD OF THE FRONT WERE IN THE MID TO UPPER 50S. THE 19Z SPC THERMODYNAMICS FIELDS SUGGEST MODEST INSTABILITY WITH VERY WEEK MOISTURE CONVERGENCE ALONG THE FRONT. THROUGH THE EARLY EVENING...EXPECT THE FRONT TO SLOWLY MOVE SOUTHEAST REACHING DAVIS COUNTY BY 7 PM. 12Z GFS/NAM AND THE LATEST HRRR DEVELOP SHOWERS OR THUNDERSTORMS NEAR THE FRONT THIS EVENING. THERE WILL BE ENOUGH INSTABILITY AND LIFT TO KEEP A SMALL CONDITIONAL CHANCE OF SHOWERS AND THUNDERSTORMS IN THE FORECAST. WEAK MID LEVEL FORCING AHEAD OF POSITIVELY TILTED 700 MB TROUGH AND MID-LEVEL MOISTURE MAY BE ADEQUATE TO PRODUCE SCATTERED SHOWERS OVER SOUTH CENTRAL IOWA TONIGHT ALONG WITH CLOUDINESS. PREVIOUS TEMPERATURE FORECAST LOOKED GOOD REQUIRING ONLY MINOR ADJUSTMENTS. .LONG TERM /SATURDAY THROUGH FRIDAY/... RATHER QUIET PERIOD TO CONTINUE INTO THE WEEKEND AND NEXT WEEK. A FEW ITEMS TO MENTION INCLUDING COLD FRONTAL BOUNDARY HANGING UP OVER CENTRAL TO NORTHERN MO ON SATURDAY MAY HAVE ENOUGH ISENTROPIC LIFT TO KEEP A FEW SHOWERS OVER FAR SOUTHERN IOWA SATURDAY AND SATURDAY EVENING. CLOUDS WILL ALSO LINGER OVER THE SOUTH ON SATURDAY BUT SHOULD EXIT THE REGION BY SATURDAY EVENING LEAVING SUNDAY MAINLY SUNNY AND QUIET. MODEST FLOW REMAINS ACROSS THE NORTHERN TIER STATES WITH A FEW WAVES TRAVELING ALONG THE US CAN BORDER. A WEAK COOL FRONT HAS BEEN ADVERTISED TO CROSS THE REGION BY TUESDAY EVENING OR WEDNESDAY MORNING. THIS WILL ALLOW FOR SLIGHTLY COOLER AIR TO DROP INTO THE REGION FOR A DAY PRIOR TO THE FRONT LIFTING BACK NORTH BY WEDNESDAY NIGHT AND THURSDAY. CLIMATOLOGY FAVORS SOME THUNDER ACTIVITY AS THE FRONT LIFTS NORTH...BUT MODELS REMAIN RATHER DRY AS FLOW OVER THE SOUTH HAS BEEN SHUT DOWN WITH WEAK LOW PRESSURE AND NORTHWEST FLOW HUGGING THE GULF COAST. THUS...AM RELUCTANT TO GET TOO EXCITED ABOUT POP IN THE REMAINDER OF THE EXTENDED PERIOD UNTIL A STRONGER WAVE DROPS INTO THE WEST. IT APPEARS THAT THE NEXT OPPORTUNITY FOR THAT WILL COME 24 TO 48 HOURS FOLLOWING THE CURRENT EXTENDED FORECAST. FORECAST HIGHS WILL WARM NICELY BY THE END OF THE EXTENDED PERIOD. WITH SW FLOW IN PLACE AND GOOD MIXING COMBINED WITH H850 TEMPS OF 17-19C...WILL LIKELY SEE HIGHS IN THE MID TO UPPER 80S IF THE TREND HOLDS. COORD WITH SURROUNDING OFFICES WITH LOWER 80S IN MIND AND WILL WAIT FOR A FEW MORE CONFIRMATION RUNS PRIOR TO RAISING TEMPS HIGHER...BUT BOTH H500 PATTERN WITH RIDGE BUILDING OVER THE LOWER MS RIVER VALLEY AND INCREASING H850 TEMPS SUPPORT VERY WARM AND INCREASINGLY HUMID AIRMASS NORTH INTO THE REGION. EURO THICKNESS BY 00Z SAT 5/19 BACK TO 570-573DM WHICH IS RATHER SUMMER LIKE. && .AVIATION...12/06Z COLD FRONT HAS MOVED PAST KOTM WITH NO PRECIPITATION CURRENTLY IN THE FORECAST AREA. PRECIP ASSOCIATED WITH SW-NE ORIENTED SIOUXLAND UPPER SYSTEM HAS DISSIPATED AS WELL. ATTENTION WILL THEN TURN TO OK UPPER LOW AND SCATTERED SHOWERS ACROSS KS. SHOWERS WITH THIS SYSTEM MAY MOVE NE AND AFFECT SRN TAF SITES /KDSM/KOTM/ AT ANY TIME THROUGH 00Z BUT CONFIDENCE IN ANY PARTICULAR LOCATION OR TIMING IS LOW SO WILL LEAVE DRY INSTEAD OF PROLONGED VCSH MENTION. EVEN IF PRECIP DOES DEVELOP...EXPECT CONDITIONS TO REMAIN VFR. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...JOHNSON LONG TERM...REV AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1141 PM CDT FRI MAY 11 2012 .AVIATION... A COLD FRONT WILL PASS SOUTHEAST OF THE AREA BY 07Z. FOLLOWING THE FRONTAL PASSAGE BEYOND 10Z...BUT WITH LIMITED COVERAGE ISOLATED TO SCATTERED AREAS OF LIGHT PRECIPITATION EXPECTED...WILL CONTINUE VC WORDING FOR SHOWERS THIS MORNING INTO SATURDAY AFTERNOON AND EVENING AND NOT INCLUDE ANY MENTION OF THUNDER...AT CID...MLI...BRL TERMINALS. PROB30 GROUP AT BRL TERMINAL WHERE GREATEST RISK OF SHOWERS LATE MORNING INTO MID AFTERNOON. NORTH WINDS OF 5 TO 12 KTS WILL VEER TO THE NORTHEAST SATURDAY MORNING. VFR FLIGHT RULES TO PERSIST...WITH A BRIEF PERIOD OF MVFR CIGS POSSIBLE WITH THE STRONGEST PRECIPITATION SATURDAY MORNING INTO AFTERNOON POSSIBLY AT BRL TERMINAL. NICHOLS && .PREV DISCUSSION... /ISSUED 312 PM CDT FRI MAY 11 2012/ SYNOPSIS... MOISTURE STARVED SURFACE COLD FRONT CONTINUES CRAWL SLOWLY ACROSS IA THIS AFTERNOON...REACHING FROM WEST CENTRAL WI...TROUGH MASON CITY TO WEST OF DES MOINES...INTO FAR NW MO AT 19Z. VISIBLE SATELLITE SHOWED MOSTLY CLEAR SKIES OVER THE FORECAST AREA WITH SIGNIFICANT CLOUD COVER NEAR THE BOUNDARY LIMITED TO MN AND WI...WHILE POST FRONTAL CLOUDS ASSOCIATED WITH HIGHER MOISTURE AND MID AND UPPER LEVEL FORCING WERE WELL TO THE NW FROM NW NEB THROUGH SE SD INTO MN. AREA RADAR MOSAIC INDICATED A BAND OF SHOWERS WELL BEHIND THE FRONT FROM W CENTRAL MN INTO N CENTRAL NEB. ISOLATED HIGH BASED SHOWERS WERE BEGINNING TO POP UP IN W CENTRAL AND NW IA OVER THE PAST HOUR. TEMPERATURES WERE INTO THE UPPER 70S TO LOWER 80S OVER THE FORECAST AREA...WHILE UPPER 60S TO LOWER 70S WERE FOUND WEST OF THE BOUNDARY ACROSS WESTERN IA AND SW MN. SHORT TERM...TONIGHT AND SATURDAY... PRIMARY CHALLENGE IS RAIN CHANCES AS THE COLD FRONT PUSHES THROUGH THE AREA TONIGHT INTO SATURDAY. WITH GULF MOISTURE RATHER MEAGER AND LIMITED BY A LOW MOVING ACROSS TX TODAY...SURFACE DEWPOINTS HAVE ONLY REACHED A NARROW AXIS OF MID 50S AHEAD OF THE FRONT...AND 850 MB ANALYSIS FROM THIS MORNING WOULD SUGGEST BULK OF GULF MOISTURE TO REMAIN CUTOFF IN THE SOUTHERN PLAINS. CLOSE INSPECTION OF THE LATEST VISIBLE SATELLITE SHOWS THE FIRST CU OF THE DAY STARTING TO POP ALONG THE BOUNDARY NEAR DSM...AND WILL WATCH THIS DEVELOPMENT ALONG AND AHEAD OF THE FRONT FOR POSSIBLE SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS MUCAPES RISE TO VALUES WELL BELOW 1000 J/KG. OTHERWISE...IT LOOKS LIKE THE BETTER FORCING FOR SHOWERS TONIGHT WILL MORE CLOSELY TIED TO THE WEAK FORCING AND MOISTURE AROUND 700 MB ASSOCIATED WITH THE CURRENT AXIS OF POST FRONTAL SHOWERS. THIS FEATURE FOLLOWS THE FRONT INTO THE FORECAST AREA LATER THIS EVENING AND OVERNIGHT AND WILL KEEP CHANCE POPS IN PLACE. WILL KEEP AN MENTION OF ISOLATED THUNDERSTORMS FOR THE EVENING FOR THE POSSIBLE DEVELOPMENT OF CONVECTION ALONG THE ADVANCING BOUNDARY...WHICH IS STILL SUGGESTED AS POSSIBILITY BY THE HRRR MODEL. OTHERWISE... INCREASING CLOUD COVER WILL OFFSET THE LOW LEVEL COLD AIR ADVECTION BEHIND THE WEAKENING COLD FRONT AND LIMIT LOWS TO AROUND 50 NORTH TO THE MID 50S SOUTH. SATURDAY...THE FRONT CONTINUES TO WEAKEN AND SLOW AS IT DROPS TOWARD THE UPPER LEVEL SYSTEM MOVING THROUGH THE MID MS VALLEY. WEAK MID LEVEL FORCING AND MOISTURE IS SHOWN POOLING NORTH OF THE BOUNDARY THROUGH AT LEAST THE MORNING HOURS TO JUSTIFY CHANCE POPS FOR LIGHT RAIN SHOWERS. THIS THEN SHIFTS TO THE FAR SOUTH IN THE AFTERNOON AS SURFACE HIGH PRESSURE BUILDS OVER THE NORTHERN PLAINS INTO THE UPPER MS VALLEY...INCREASING THE LOW LEVEL FLOW OF DRY AIR INTO THE AREA. LINGERING MID AND HIGH LEVEL MOISTURE AND WEAK FORCING EMBEDDED IN THE MID LEVEL CYCLONIC FLOW TO THE NORTH WILL LIKELY KEEP SKIES MOSTLY CLOUDY AND WILL LIMIT HIGHS TO THE 60S OVER MOST OF THE AREA. SHEETS LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY... MAIN FOCUS THIS FORECAST TIME RANGE IS ON PRECIPITATION CHANCES SATURDAY NIGHT AND AGAIN WEDNESDAY THROUGH FRIDAY. SATURDAY NIGHT AND SUNDAY THE COLD FRONT CONTINUES TO SAG SOUTH. THE 850MB BOUNDARY REMAINS IN THE AREA SATURDAY NIGHT AND A WEAK VORT MAX WILL DROP SOUTH ACROSS THE AREA. THIS MAY PRODUCE SOME ELEVATED SHOWERS SATURDAY NIGHT...MAINLY IN THE EVENING. MOISTURE IS A LIMITING FACTOR SO HAVE KEPT PRECIPITATION CHANCES IN THE SLIGHT CHANCE CATEGORY. TEMPERATURES TO BE MILD BOTH PERIODS WITH CLOUDS TEMPERING THE COOLER AND DRIER AIR COMING IN FROM THE NORTH. MINS SATURDAY NIGHT IN THE 40S AND LOW 50S. HIGHS SUNDAY TO BE IN THE LOW 70S. MONDAY AND TUESDAY A WEAK SURFACE RIDGE TO BUILD SOUTH ACROSS THE AREA WITH WEAK WESTERLY RETURN FLOW SETTING UP FOR TUESDAY. THIS WILL ALLOW TEMPERATURES TO RISE SO THAT ON TUESDAY WE WILL HAVE HIGHS IN THE UPPER 70S AGAIN...POSSIBLY EVEN SOME MORE LOW 80S. FORECAST HIGHS MAY NEED TO BE RAISED IF IT STILL APPEARS WE WILL BE WORKING WITH VERY DRY AIR AND DEEP MIXING. WEDNESDAY THROUGH FRIDAY THE SURFACE RIDGE SLIPS OFF TO THE SOUTHEAST AND SOUTHWEST RETURN FLOW SETS IN IN EARNEST WITH A LONG FETCH FROM TEXAS...AND BY FRIDAY IT APPEARS THAT THERE WILL BE STREAM OF GULF MOISTURE HEADING OUR DIRECTION. A FAIRLY STRONG UPPER LEVEL SYSTEM OVER CANADA WILL PUSH A COLD FRONT TOWARDS THE AREA WEDNESDAY. THIS FRONT MAY DROP INTO THE AREA WEDNESDAY... THOUGH THERE IS SOME MODEL DISAGREEMENT HERE...WITH SOME KEEPING IT NORTH OF THE AREA. FOR NOW HAVE KEPT THE FORECAST DRY AS THERE IS LITTLE MOISTURE AVAILABLE FOR THIS BOUNDARY TO WORK WITH. A SURFACE LOW IS GENERATED OVER WESTERN KANSAS...AND BY THURSDAY AND FRIDAY THE FRONT BECOMES A WARM FRONT AND PUSHES BACK NORTH...AND WILL BE GENERALLY DRAPED FROM SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND INTO WISCONSIN. UNLESS THIS CHANGES THIS IS LIKELY TO BE THE STORM TRACK NEXT WEEK...AND WE WILL BE SITTING IN A VERY WARM AND INCREASINGLY HUMID AIRMASS BOTH DAYS...WITH HIGHS INTO THE LOW 80S. HAVE SOME VERY LOW END CHANCE POPS IN THE FORECAST...BUT UNLESS THE FRONT SHIFTS CLOSER TO THE AREA AM ANTICIPATING WE WILL BE DRY. LE && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
843 PM MDT SUN MAY 13 2012 .UPDATE... ISSUED AT 837 PM MDT SUN MAY 13 2012 JUST ISSUED ANOTHER UPDATE. CURRENT PRECIPITATION FORECAST IS TRENDING AND MADE NO CHANGES. THERE WAS LITTLE WIND/MIXING THROUGH THE DAY WITH DEWPOINTS NEARLY THE SAME TODAY AS YESTERDAY. AREA SOUNDINGS SHOW THAT THE LOW LEVEL MOISTURE HAS ALSO CHANGED LITTLE ALTHOUGH THE AIR MASS HAS WARMED. WITH A SIMILAR AIR MASS YESTERDAY THERE WAS SOME MORNING FOG. ALSO CLUSTER OF THUNDERSTORMS DROPPED A DECENT AMOUNT OF RAINFALL OVER A RATHER LARGE AREA OVER WESTERN KIT CARSON AND CHEYENNE COUNTIES. WINDS WILL BE LIGHT AND THEN WILL SHIFT TO THE WEST TO BRING THIS MOISTURE IN FROM THE WEST. CONSIDERING THE RUC THAT HAS A GOOD HANDLE ON THE WIND FIELD...DRIER AIR WORKS ITS WAY INTO THE NORTHEAST HALF OF THE AREA. RUC AND TO A LESSER DEGREE THE ECMWF INCREASE LOW LEVEL MOISTURE OVER THE SOUTHWEST HALF ALTHOUGH THE RUC WOULD SAY IT WILL BE STRATUS. AS A RESULT...ADDED PATCHY TO AREAS OF FOG FOR LATER TONIGHT INTO TOMORROW MORNING. LATEST MAV WAS DOING WELL WITH THE DEWPOINTS AND AS STATED ABOVE USED THE RUC FOR THE WINDS AND BLENDED THEM WITH REALITY. OVERNIGHT LOWS LOOK FINE AT THIS TIME. UPDATE ISSUED AT 623 PM MDT SUN MAY 13 2012 PERSISTENT AND SLOW MOVING CLUSTER OF STORMS LOCATED OVER/NEAR WESTERN KIT CARSON AT THIS TIME. THIS AREA LOOKS TO BE IN AN AREA OF SURFACE/MOISTURE CONVERGENCE COMBINED WITH WEAK SHORTWAVE TROUGH AND DEEPEST MOISTURE. RAISED POPS MUCH HIGHER OUT WEST...EXPANDED AREA OF THUNDERSTORMS AND PER CONVERGENCE AND QPF FORECASTS...EXTENDED THUNDERSTORMS UNTIL 06Z. ALSO INCREASED CLOUD COVER OVER THE WEST AND SOUTHWEST PORTIONS OF THE AREA WHERE CONVECTION IS OCCURRING. OTHERWISE JUST MADE MINOR ADJUSTMENTS WITH THE REMAINING ELEMENTS. && .SHORT TERM...(THIS AFTERNOON THROUGH MONDAY EVENING) ISSUED AT 1157 AM MDT SUN MAY 13 2012 SCATTERED TO BROKEN SKY COVER THIS AFTERNOON WILL PERSIST WITH THE DAYTIME HEATING PRODUCING A WIDESPREAD CU FIELD. EXPECT THIS TO DISSIPATE RAPIDLY FOLLOWING SUNSET WITH DRYER AIR MOVING IN MONDAY AND MONDAY NIGHT AS THE RIDGE OF HIGHER PRESSURE MOVES OVER THE ROCKIES AND HIGH PLAINS REGION. THERE IS SOME CONVECTIVE ACTIVITY DEVELOPING OVER THE HIGH TERRAIN OF COLORADO THIS AFTERNOON...SO THERE IS THE POSSIBILITY OF A FEW SHOWERS MAKING THEIR WAY OVER THE FAR SOUTHWESTERN PORTION OF THE FORECAST AREA LATE THIS AFTERNOON AND EARLY EVENING. ANY SHOWERS THAT DO MAKE IT THIS FAR EAST SHOULD DISSIPATE RAPIDLY AFTER 03Z. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 236 PM MDT SUN MAY 13 2012 TUESDAY-TUESDAY NIGHT...SHORTWAVE RIDGE WILL REMAIN IN PLACE THROUGH TUESDAY NIGHT...WITH LARGE SCALE SUBSIDENCE SUPPORTING DRY CONDITIONS. MUCH WARMER TEMPERATURES ARE EXPECTED WITH GUIDANCE CONTINUING TO SUPPORT TEMPS IN THE MID TO UPPER 80S OVER MUCH OF THE CWA...WITH TEMPS AROUND 90F IN THE EAST. WEDNESDAY-THURSDAY NIGHT...VERY WARM TEMPERATURES CONTINUE WITH SOUTHERLY FLOW IN PLACE AND H85 TEMPS AROUND 25C. HIGHS ON WEDNESDAY AND THURSDAY WILL BE VERY SIMILAR TO TUESDAY...WITH HIGHS OVER MUCH OF THE CWA IN THE UPPER 80S. H5 RIDGE BEGINS TO BREAK DOWN WEDNESDAY AS A SHORTWAVE TROUGH MOVES TOWARDS THE INTER-MOUNTAIN WEST/HIGH PLAINS. STILL SOME RUN-RUN SPREAD BETWEEN GUIDANCE ON TIMING/POSITION OF THIS FEATURE...WITH 12Z ECMWF SLOWER AND DRIER. GFS AND NAM STILL SUPPORT TIMING/COVERAGE FROM PREVIOUS FORECAST WITH THUNDERSTORMS BEGINNING IN EASTERN COLORADO WEDNESDAY AFTERNOON AND SPREADING EAST ACROSS THE CWA THROUGH THURSDAY. COVERAGE IS STILL A QUESTION EVEN WITH THE GFS/NAM SOLUTIONS...WITH LIMITED MOISTURE ADVECTION AND INSTABILITY WEDNESDAY/WEDNESDAY NIGHT. I KEPT POPS LIMITED TO SLIGHT CHANCE CATEGORY...AND MADE ONLY MINOR ADJUSTMENTS TO LOCATION OF POPS IN CWA. IF GFS/NAM IS CORRECT THEN BEST CHANCE FOR PRECIP WITH THIS FEATURE MAY END UP BEING THURSDAY OVER OUR EASTERN CWA. FRIDAY-SUNDAY...SUBSIDENCE ASSOCIATED WITH SHORTWAVE RIDGE SHOULD KEEP FRIDAY WARM AND DRY. PRECIP CHANCES RETURN BY SATURDAY AS SW FLOW SET UP ACROSS CWA...AND COLD FRONT DROPS SOUTH ACROSS CWA SUNDAY. THERE IS STILL CONSIDERABLE SPREAD IN UPPER LEVEL PATTERN BETWEEN OPERATIONAL GUIDANCE...HOWEVER BOTH GFS AND ECMWF SUPPORT PRECIP CHANCES SATURDAY THROUGH SUNDAY NIGHT. I CONSIDERED RAISING POPS...HOWEVER WITH SPREAD ON UPPER LEVEL AND SURFACE FEATURES...ITS DIFFICULT TO PIN DOWN FAVORED LOCATIONS AT THIS TIME. RATHER THAN STRAY TOO FAR FROM PREVIOUS TRENDS...I KEPT POPS IN SLIGHT CHANCE/CHANCE CATEGORIES DURING THESE PERIODS TO ACCOUNT FOR MODEL SPREAD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 540 PM MDT SUN MAY 13 2012 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SMALL CLUSTER OF THUNDERSTORMS OVER EAST CENTRAL COLORADO. AT THIS TIME...THIS AREA SHOULD STAY TO THE WEST OF KGLD. OTHERWISE LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE WHOLE PERIOD. && .FIRE WEATHER... ISSUED AT 236 PM MDT SUN MAY 13 2012 RED FLAG CONDITIONS WILL BE POSSIBLE WEDNESDAY THROUGH FRIDAY WITH RH VALUES AND WINDS APPROACHING CRITERIA. BEST CHANCE FOR RED FLAG CRITERIA TO BE MET LOOKS TO BE ON WEDNESDAY AFTERNOON WHEN WINDS GUSTING OVER 25 MPH WILL BE COMMON ACROSS THE CWA. THERE ARE STILL QUESTIONS ON HOW LOW RH VALUES WILL BE WEDNESDAY WITH SHORTWAVE TROUGH MOVING IN FROM THE WEST. IF PROFILES REMAIN DRY ADIABATIC THROUGH THE AFTERNOON...CURRENT TD/RH FORECAST COULD BE TOO HIGH. THIS WILL NEED TO BE MONITORED. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...BULLER SHORT TERM...LOCKHART LONG TERM...DR AVIATION...BULLER FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
929 AM MDT SAT MAY 12 2012 .UPDATE... ISSUED AT 928 AM MDT SAT MAY 12 2012 AM UPDATING FORECAST TO BETTE DEPICT THE AREA OF LIGHT RAIN WITH A FEW EMBEDDED STRONGER SHOWERS MOVING ACROSS THE FORECAST AREA THIS MORNING. UPDATE ISSUED AT 551 AM MDT SAT MAY 12 2012 AREA OF LIGHT RAIN SHOWERS BECOMING FAIRLY WELL ORGANIZED AHEAD OF SHORT WAVE TROUGH ACROSS THE NORTHERN PART OF CWA...WITH MEASURABLE PRECIPITATION BEING OBSERVED WITH WEAKER ECHOES CONFIDENCE HAS INCREASED IN COVERAGE OF MEASURABLE PRECIP. WHILE THINK GENERAL TIMING OF FORECAST REMAINS OK...DID INCREASE MAGNITUDE OF POPS 20-30 PERCENT MAINLY ACROSS NORTHERN CWA TO ACCOUNT FOR CURRENT ACTIVITY. RADAR ECHOES BECOMING BETTER ORGANIZED TO THE SOUTH AS WELL...BUT SO FAR HAVE NOT SEEN MUCH IN THE WAY OF -RA IN OBS SO WILL CONTINUE WITH SCATTERED POPS IN THIS AREA. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 259 AM MDT SAT MAY 12 2012 230Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED CLOSE LOW CIRCULATION ACROSS THE SOUTHERN PLAINS WITH LARGE TROUGH ACROSS THE NORTHERN PLAINS WITH AN EMBEDDED SHORT WAVE TROUGH MOVING INTO WESTERN COLORADO. AT THE SURFACE 1028MB SFC HIGH WAS BUILDING OVER THE AREA BEHIND FRONTAL ZONE WHICH WAS DRAPED FROM SOUTHEAST COLORADO INTO NW MISSOURI. 00Z RAOBS...ESPECIALLY AT KLBF AND KDNR INDICATED A FAIRLY DEEP FRONT IN PLACE WITH FRONTAL INVERSION ENDING AROUND 725 MB AND 675MB RESPECTIVELY. ALTHOUGH FAIRLY DRY AIR WAS LOCATED BELOW INVERSION AT LBF...PARCELS LIFTED FROM TOP OF INVERSION DID INDICATE SOME VERY WEAK CAPE PRESENT. PRECIP CHANCES THIS MORNING THROUGH THE REST OF THE WEEKEND WILL BE PRIMARY NEAR TERM CONCERNS. TODAY...ONGOING LIGHT PRECIPITATION WILL BE PRIMARY FORECAST CHALLENGE THIS MORNING AND WITH TEMPERATURES DROPPING INTO THE 30S AND WBZ HEIGHTS FALLING TO AROUND 1500FT WOULD NOT RULE OUT A FEW SNOW FLAKES MIXING IN WITH THE PRECIPITATION IN WESTERN CWA THIS MORNING...BUT IF IT DOES OCCUR DO NOT THINK IT WILL AMOUNT TO MUCH WITH SOIL TEMPS WELL ABOVE FREEZING. AREA OF LIGHT PRECIPITATION WILL GRADUALLY SHIFT TO THE EAST THIS MORNING IN AREA OF WEAK ISENTROPIC ASCENT AND H7 FRONTOGENESIS. INITIALLY THOUGHT THIS WOULD BE THE ONLY AREA OF PRECIPITATION...BUT LOOKING UPSTREAM STARTING TO SEE REDEVELOPMENT OF PRECIPITATION IN AREA THAT LOOKS TO BE DIRECTLY AHEAD OF WEAK SHORT WAVE TROUGH AS PER WV IMAGERY AND RUC PV ANALYSIS. TIMING THIS FEATURE PUTS IT OVER NORTHERN CWA BY 15Z...WHICH IS CONSISTENT WITH TIMING OF PRECIP AMONGST VARIOUS MODELS AND SREF DATA AND HAVE MODIFIED FORECAST TO ACCOUNT FOR THIS TIMING. THINK PRECIP THREAT WILL END FAIRLY QUICKLY AS THIS TROUGH PASSES AND THINK WE WILL SEE A PERIOD OF NO PRECIPITATION ACROSS THE CWA AROUND 21Z. FOR ACTUAL PROBABILITY VALUES...GIVEN A LARGE DEGREE OF SPREAD IN ACTUAL PLACEMENT OF PRECIP MAXIMA AND SURPRISINGLY LOW PROBABILITIES OF 0.05 OR GREATER FROM THE GEFS DATA AM A LITTLE HESITANT TO GO TOO HIGH ON POPS...BUT THINK A GENERAL 30-50% CHANCE IS WARRANTED FOR A GOOD PORTION OF THE AREA. THE ACTUAL MAGNITUDE OF POPS WILL DEPEND STRONGLY ON BEHAVIOR OF UPSTREAM PRECIP OVER THE NEXT FEW HOURS. TONIGHT-SUNDAY...BRIEF PERIOD OF SUBSIDENCE WILL OVERSPREAD THE AREA AT THE START OF THE PERIOD AS INITIAL SHORT WAVE TROUGH MOVES TO THE EAST OF THE AREA....BEFORE NEXT TROUGH BEGINS TO DIVE INTO COLORADO THROUGH THE OVERNIGHT HOURS. SUBSIDENCE DOES NOT LOOK ALL THAT STRONG AT THIS POINT BUT DEFINITELY THINK LOWEST CHANCES FOR RAIN WILL BE IN THE EARLY EVENING. MODELS HAVE HAD A BIT OF DIFFICULTY WITH THE HANDLING OF THIS SYSTEM...JUMPING FROM VERY WET TO DRY SOLUTIONS OVER THE PAST SEVERAL RUNS SO OVERALL CONFIDENCE IS NOT THAT HIGH. LARGE SCALE FORCING FOR ASCENT WILL INCREASE THROUGH THE NIGHT WITH STRONGEST VALUES BETWEEN 9Z AND 18Z SUNDAY...WITH SYNOPTIC SCALE FORCING MAXIMIZED OVER COLORADO AND CWA REALLY ON THE FRINGE OF STRONGEST FORCED ASCENT. APPEARS TO BE A WINDOW WITH STRONG H7 TO H5 FRONTOGENESIS DEVELOPING ACROSS THE SOUTHWESTERN CWA...BUT HAVE SOME CONCERNS THAT A LOT OF THIS FORCING IS SOMEWHAT DUE TO CONVECTIVE FEEDBACK ESPECIALLY ON THE GFS WHICH SEEMS TO DEVELOP SMALL LOW CIRCULATION OVERNIGHT SATURDAY WHICH MAXIMIZES FORCING. VERY HIGH QPF FIELDS IN SPITE OF MINIMAL INSTABILITY ALSO MAKE ME THINK THAT THERE IS SOME FEEDBACK ISSUES AT PLAY WITH THE BULLS EYE OF ASCENT. WITH THAT IN MIND...DO NOT WANT TO RAMP UP POPS/QPFS AT THIS TIME DUE TO LOW CONFIDENCE IN THE PREDICTABILITY OF THESE FEATURES...BUT FEEL 30-50% POPS WARRANTED FOR THE TIME BEING. WITH VERY LITTLE IF ANY ELEVATED CAPE HAVE DECIDED TO KEEP WX GROUPS AS JUST RAIN. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 259 AM MDT SAT MAY 12 2012 SUNDAY NIGHT-MONDAY NIGHT...QUIETER WEATHER EXPECTED THROUGH THE PERIOD AS MAJORITY OF OPERATIONAL DATA SUGGEST SHORT WAVE RIDGING BUILDING OVER THE THE AREA THROUGH THE REST OF THE PERIOD BEHIND DEPARTING TROUGH WITH SUBSIDENCE/DRYING QUICKLY BRINGING AN END TO ANY PRECIP THREAT ACROSS THE AREA. MAIN FOCUS WILL BE HOW QUICKLY TEMPERATURES RECOVER THROUGH THE PERIOD. GENERAL WARMING TREND LOOKS TO BE IN ORDER...BUT GIVEN SOME MUCH COLDER DATA IN SREF PLUMES AM A LITTLE HESITANT TO WARM THINGS TOO MUCH AT THIS POINT. THE REGION WILL BE UNDER THE EASTERN PORTION OF AN UPPER LEVEL RIDGE OF HIGH PRESSURE AT THE BEGINNING OF THE PERIOD...WITH DRY CONDITIONS EXPECTED THROUGH DAYTIME WEDNESDAY. A SHORTWAVE TROUGH WILL APPROACH THE REGION ON WEDNESDAY NIGHT AND MOVE OVER THE REGION DURING THE DAYTIME ON THURSDAY. GIVEN THE INSTABILITY EXPECTED DURING THIS PERIOD...HAVE INCLUDED MENTION OF THUNDERSTORMS WITH THE SLIGHT CHANCE OF PRECIPITATION...THOUGH CONVECTIVE INHIBITION IS STILL FAIRLY STRONG OVER MUCH OF THE AREA DURING THIS TIME. THE UPPER LEVEL FLOW WILL BEGIN TO BECOME MORE ZONAL BY THE END OF THE PERIOD AS THE UPPER RIDGE MOVES EASTWARD...AND ANOTHER SHORTWAVE TROUGH BEGINS TO APPROACH THE REGION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 551 AM MDT SAT MAY 12 2012 AREA OF PRECIPITATION DEVELOPING AHEAD OF SHORT WAVE TROUGH WILL BE PRIMARY CONCERN AT BOTH TERMINALS WITH LIGHT RAIN ALREADY OCCURRING AT GLD AND MCK AND WILL LIKELY PERSIST THROUGH 17Z AT GLD AND 20Z AT MCK. MAY SEE A PERIOD OF NEAR MVFR CIGS THROUGH THE MORNING HOURS...BUT BASED OFF OF CURRENT TRENDS DO NOT THINK CIGS WILL GET MUCH LOWER THAN 3000 FT AT THIS TIME. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...LOCKHART SHORT TERM...JRM LONG TERM...JRM/CJS AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
605 AM MDT SAT MAY 12 2012 .UPDATE... ISSUED AT 551 AM MDT SAT MAY 12 2012 AREA OF LIGHT RAIN SHOWERS BECOMING FAIRLY WELL ORGANIZED AHEAD OF SHORT WAVE TROUGH ACROSS THE NORTHERN PART OF CWA...WITH MEASURABLE PRECIPITATION BEING OBSERVED WITH WEAKER ECHOES CONFIDENCE HAS INCREASED IN COVERAGE OF MEASURABLE PRECIP. WHILE THINK GENERAL TIMING OF FORECAST REMAINS OK...DID INCREASE MAGNITUDE OF POPS 20-30 PERCENT MAINLY ACROSS NORTHERN CWA TO ACCOUNT FOR CURRENT ACTIVITY. RADAR ECHOES BECOMING BETTER ORGANIZED TO THE SOUTH AS WELL...BUT SO FAR HAVE NOT SEEN MUCH IN THE WAY OF -RA IN OBS SO WILL CONTINUE WITH SCATTERED POPS IN THIS AREA. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 259 AM MDT SAT MAY 12 2012 230Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED CLOSE LOW CIRCULATION ACROSS THE SOUTHERN PLAINS WITH LARGE TROUGH ACROSS THE NORTHERN PLAINS WITH AN EMBEDDED SHORT WAVE TROUGH MOVING INTO WESTERN COLORADO. AT THE SURFACE 1028MB SFC HIGH WAS BUILDING OVER THE AREA BEHIND FRONTAL ZONE WHICH WAS DRAPED FROM SOUTHEAST COLORADO INTO NW MISSOURI. 00Z RAOBS...ESPECIALLY AT KLBF AND KDNR INDICATED A FAIRLY DEEP FRONT IN PLACE WITH FRONTAL INVERSION ENDING AROUND 725 MB AND 675MB RESPECTIVELY. ALTHOUGH FAIRLY DRY AIR WAS LOCATED BELOW INVERSION AT LBF...PARCELS LIFTED FROM TOP OF INVERSION DID INDICATE SOME VERY WEAK CAPE PRESENT. PRECIP CHANCES THIS MORNING THROUGH THE REST OF THE WEEKEND WILL BE PRIMARY NEAR TERM CONCERNS. TODAY...ONGOING LIGHT PRECIPITATION WILL BE PRIMARY FORECAST CHALLENGE THIS MORNING AND WITH TEMPERATURES DROPPING INTO THE 30S AND WBZ HEIGHTS FALLING TO AROUND 1500FT WOULD NOT RULE OUT A FEW SNOW FLAKES MIXING IN WITH THE PRECIPITATION IN WESTERN CWA THIS MORNING...BUT IF IT DOES OCCUR DO NOT THINK IT WILL AMOUNT TO MUCH WITH SOIL TEMPS WELL ABOVE FREEZING. AREA OF LIGHT PRECIPITATION WILL GRADUALLY SHIFT TO THE EAST THIS MORNING IN AREA OF WEAK ISENTROPIC ASCENT AND H7 FRONTOGENESIS. INITIALLY THOUGHT THIS WOULD BE THE ONLY AREA OF PRECIPITATION...BUT LOOKING UPSTREAM STARTING TO SEE REDEVELOPMENT OF PRECIPITATION IN AREA THAT LOOKS TO BE DIRECTLY AHEAD OF WEAK SHORT WAVE TROUGH AS PER WV IMAGERY AND RUC PV ANALYSIS. TIMING THIS FEATURE PUTS IT OVER NORTHERN CWA BY 15Z...WHICH IS CONSISTENT WITH TIMING OF PRECIP AMONGST VARIOUS MODELS AND SREF DATA AND HAVE MODIFIED FORECAST TO ACCOUNT FOR THIS TIMING. THINK PRECIP THREAT WILL END FAIRLY QUICKLY AS THIS TROUGH PASSES AND THINK WE WILL SEE A PERIOD OF NO PRECIPITATION ACROSS THE CWA AROUND 21Z. FOR ACTUAL PROBABILITY VALUES...GIVEN A LARGE DEGREE OF SPREAD IN ACTUAL PLACEMENT OF PRECIP MAXIMA AND SURPRISINGLY LOW PROBABILITIES OF 0.05 OR GREATER FROM THE GEFS DATA AM A LITTLE HESITANT TO GO TOO HIGH ON POPS...BUT THINK A GENERAL 30-50% CHANCE IS WARRANTED FOR A GOOD PORTION OF THE AREA. THE ACTUAL MAGNITUDE OF POPS WILL DEPEND STRONGLY ON BEHAVIOR OF UPSTREAM PRECIP OVER THE NEXT FEW HOURS. TONIGHT-SUNDAY...BRIEF PERIOD OF SUBSIDENCE WILL OVERSPREAD THE AREA AT THE START OF THE PERIOD AS INITIAL SHORT WAVE TROUGH MOVES TO THE EAST OF THE AREA....BEFORE NEXT TROUGH BEGINS TO DIVE INTO COLORADO THROUGH THE OVERNIGHT HOURS. SUBSIDENCE DOES NOT LOOK ALL THAT STRONG AT THIS POINT BUT DEFINITELY THINK LOWEST CHANCES FOR RAIN WILL BE IN THE EARLY EVENING. MODELS HAVE HAD A BIT OF DIFFICULTY WITH THE HANDLING OF THIS SYSTEM...JUMPING FROM VERY WET TO DRY SOLUTIONS OVER THE PAST SEVERAL RUNS SO OVERALL CONFIDENCE IS NOT THAT HIGH. LARGE SCALE FORCING FOR ASCENT WILL INCREASE THROUGH THE NIGHT WITH STRONGEST VALUES BETWEEN 9Z AND 18Z SUNDAY...WITH SYNOPTIC SCALE FORCING MAXIMIZED OVER COLORADO AND CWA REALLY ON THE FRINGE OF STRONGEST FORCED ASCENT. APPEARS TO BE A WINDOW WITH STRONG H7 TO H5 FRONTOGENESIS DEVELOPING ACROSS THE SOUTHWESTERN CWA...BUT HAVE SOME CONCERNS THAT A LOT OF THIS FORCING IS SOMEWHAT DUE TO CONVECTIVE FEEDBACK ESPECIALLY ON THE GFS WHICH SEEMS TO DEVELOP SMALL LOW CIRCULATION OVERNIGHT SATURDAY WHICH MAXIMIZES FORCING. VERY HIGH QPF FIELDS IN SPITE OF MINIMAL INSTABILITY ALSO MAKE ME THINK THAT THERE IS SOME FEEDBACK ISSUES AT PLAY WITH THE BULLS EYE OF ASCENT. WITH THAT IN MIND...DO NOT WANT TO RAMP UP POPS/QPFS AT THIS TIME DUE TO LOW CONFIDENCE IN THE PREDICTABILITY OF THESE FEATURES...BUT FEEL 30-50% POPS WARRANTED FOR THE TIME BEING. WITH VERY LITTLE IF ANY ELEVATED CAPE HAVE DECIDED TO KEEP WX GROUPS AS JUST RAIN. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 259 AM MDT SAT MAY 12 2012 SUNDAY NIGHT-MONDAY NIGHT...QUIETER WEATHER EXPECTED THROUGH THE PERIOD AS MAJORITY OF OPERATIONAL DATA SUGGEST SHORT WAVE RIDGING BUILDING OVER THE THE AREA THROUGH THE REST OF THE PERIOD BEHIND DEPARTING TROUGH WITH SUBSIDENCE/DRYING QUICKLY BRINGING AN END TO ANY PRECIP THREAT ACROSS THE AREA. MAIN FOCUS WILL BE HOW QUICKLY TEMPERATURES RECOVER THROUGH THE PERIOD. GENERAL WARMING TREND LOOKS TO BE IN ORDER...BUT GIVEN SOME MUCH COLDER DATA IN SREF PLUMES AM A LITTLE HESITANT TO WARM THINGS TOO MUCH AT THIS POINT. THE REGION WILL BE UNDER THE EASTERN PORTION OF AN UPPER LEVEL RIDGE OF HIGH PRESSURE AT THE BEGINNING OF THE PERIOD...WITH DRY CONDITIONS EXPECTED THROUGH DAYTIME WEDNESDAY. A SHORTWAVE TROUGH WILL APPROACH THE REGION ON WEDNESDAY NIGHT AND MOVE OVER THE REGION DURING THE DAYTIME ON THURSDAY. GIVEN THE INSTABILITY EXPECTED DURING THIS PERIOD...HAVE INCLUDED MENTION OF THUNDERSTORMS WITH THE SLIGHT CHANCE OF PRECIPITATION...THOUGH CONVECTIVE INHIBITION IS STILL FAIRLY STRONG OVER MUCH OF THE AREA DURING THIS TIME. THE UPPER LEVEL FLOW WILL BEGIN TO BECOME MORE ZONAL BY THE END OF THE PERIOD AS THE UPPER RIDGE MOVES EASTWARD...AND ANOTHER SHORTWAVE TROUGH BEGINS TO APPROACH THE REGION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 551 AM MDT SAT MAY 12 2012 AREA OF PRECIPITATION DEVELOPING AHEAD OF SHORT WAVE TROUGH WILL BE PRIMARY CONCERN AT BOTH TERMINALS WITH LIGHT RAIN ALREADY OCCURRING AT GLD AND MCK AND WILL LIKELY PERSIST THROUGH 17Z AT GLD AND 20Z AT MCK. MAY SEE A PERIOD OF NEAR MVFR CIGS THROUGH THE MORNING HOURS...BUT BASED OFF OF CURRENT TRENDS DO NOT THINK CIGS WILL GET MUCH LOWER THAN 3000 FT AT THIS TIME. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JRM SHORT TERM...JRM LONG TERM...JRM/CJS AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
302 AM MDT SAT MAY 12 2012 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 259 AM MDT SAT MAY 12 2012 230Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED CLOSE LOW CIRCULATION ACROSS THE SOUTHERN PLAINS WITH LARGE TROUGH ACROSS THE NORTHERN PLAINS WITH AN EMBEDDED SHORT WAVE TROUGH MOVING INTO WESTERN COLORADO. AT THE SURFACE 1028MB SFC HIGH WAS BUILDING OVER THE AREA BEHIND FRONTAL ZONE WHICH WAS DRAPED FROM SOUTHEAST COLORADO INTO NW MISSOURI. 00Z RAOBS...ESPECIALLY AT KLBF AND KDNR INDICATED A FAIRLY DEEP FRONT IN PLACE WITH FRONTAL INVERSION ENDING AROUND 725 MB AND 675MB RESPECTIVELY. ALTHOUGH FAIRLY DRY AIR WAS LOCATED BELOW INVERSION AT LBF...PARCELS LIFTED FROM TOP OF INVERSION DID INDICATE SOME VERY WEAK CAPE PRESENT. PRECIP CHANCES THIS MORNING THROUGH THE REST OF THE WEEKEND WILL BE PRIMARY NEAR TERM CONCERNS. TODAY...ONGOING LIGHT PRECIPITATION WILL BE PRIMARY FORECAST CHALLENGE THIS MORNING AND WITH TEMPERATURES DROPPING INTO THE 30S AND WBZ HEIGHTS FALLING TO AROUND 1500FT WOULD NOT RULE OUT A FEW SNOW FLAKES MIXING IN WITH THE PRECIPITATION IN WESTERN CWA THIS MORNING...BUT IF IT DOES OCCUR DO NOT THINK IT WILL AMOUNT TO MUCH WITH SOIL TEMPS WELL ABOVE FREEZING. AREA OF LIGHT PRECIPITATION WILL GRADUALLY SHIFT TO THE EAST THIS MORNING IN AREA OF WEAK ISENTROPIC ASCENT AND H7 FRONTOGENESIS. INITIALLY THOUGHT THIS WOULD BE THE ONLY AREA OF PRECIPITATION...BUT LOOKING UPSTREAM STARTING TO SEE REDEVELOPMENT OF PRECIPITATION IN AREA THAT LOOKS TO BE DIRECTLY AHEAD OF WEAK SHORT WAVE TROUGH AS PER WV IMAGERY AND RUC PV ANALYSIS. TIMING THIS FEATURE PUTS IT OVER NORTHERN CWA BY 15Z...WHICH IS CONSISTENT WITH TIMING OF PRECIP AMONGST VARIOUS MODELS AND SREF DATA AND HAVE MODIFIED FORECAST TO ACCOUNT FOR THIS TIMING. THINK PRECIP THREAT WILL END FAIRLY QUICKLY AS THIS TROUGH PASSES AND THINK WE WILL SEE A PERIOD OF NO PRECIPITATION ACROSS THE CWA AROUND 21Z. FOR ACTUAL PROBABILITY VALUES...GIVEN A LARGE DEGREE OF SPREAD IN ACTUAL PLACEMENT OF PRECIP MAXIMA AND SURPRISINGLY LOW PROBABILITIES OF 0.05 OR GREATER FROM THE GEFS DATA AM A LITTLE HESITANT TO GO TOO HIGH ON POPS...BUT THINK A GENERAL 30-50% CHANCE IS WARRANTED FOR A GOOD PORTION OF THE AREA. THE ACTUAL MAGNITUDE OF POPS WILL DEPEND STRONGLY ON BEHAVIOR OF UPSTREAM PRECIP OVER THE NEXT FEW HOURS. TONIGHT-SUNDAY...BRIEF PERIOD OF SUBSIDENCE WILL OVERSPREAD THE AREA AT THE START OF THE PERIOD AS INITIAL SHORT WAVE TROUGH MOVES TO THE EAST OF THE AREA....BEFORE NEXT TROUGH BEGINS TO DIVE INTO COLORADO THROUGH THE OVERNIGHT HOURS. SUBSIDENCE DOES NOT LOOK ALL THAT STRONG AT THIS POINT BUT DEFINITELY THINK LOWEST CHANCES FOR RAIN WILL BE IN THE EARLY EVENING. MODELS HAVE HAD A BIT OF DIFFICULTY WITH THE HANDLING OF THIS SYSTEM...JUMPING FROM VERY WET TO DRY SOLUTIONS OVER THE PAST SEVERAL RUNS SO OVERALL CONFIDENCE IS NOT THAT HIGH. LARGE SCALE FORCING FOR ASCENT WILL INCREASE THROUGH THE NIGHT WITH STRONGEST VALUES BETWEEN 9Z AND 18Z SUNDAY...WITH SYNOPTIC SCALE FORCING MAXIMIZED OVER COLORADO AND CWA REALLY ON THE FRINGE OF STRONGEST FORCED ASCENT. APPEARS TO BE A WINDOW WITH STRONG H7 TO H5 FRONTOGENESIS DEVELOPING ACROSS THE SOUTHWESTERN CWA...BUT HAVE SOME CONCERNS THAT A LOT OF THIS FORCING IS SOMEWHAT DUE TO CONVECTIVE FEEDBACK ESPECIALLY ON THE GFS WHICH SEEMS TO DEVELOP SMALL LOW CIRCULATION OVERNIGHT SATURDAY WHICH MAXIMIZES FORCING. VERY HIGH QPF FIELDS IN SPITE OF MINIMAL INSTABILITY ALSO MAKE ME THINK THAT THERE IS SOME FEEDBACK ISSUES AT PLAY WITH THE BULLS EYE OF ASCENT. WITH THAT IN MIND...DO NOT WANT TO RAMP UP POPS/QPFS AT THIS TIME DUE TO LOW CONFIDENCE IN THE PREDICTABILITY OF THESE FEATURES...BUT FEEL 30-50% POPS WARRANTED FOR THE TIME BEING. WITH VERY LITTLE IF ANY ELEVATED CAPE HAVE DECIDED TO KEEP WX GROUPS AS JUST RAIN. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 259 AM MDT SAT MAY 12 2012 SUNDAY NIGHT-MONDAY NIGHT...QUIETER WEATHER EXPECTED THROUGH THE PERIOD AS MAJORITY OF OPERATIONAL DATA SUGGEST SHORT WAVE RIDGING BUILDING OVER THE THE AREA THROUGH THE REST OF THE PERIOD BEHIND DEPARTING TROUGH WITH SUBSIDENCE/DRYING QUICKLY BRINGING AN END TO ANY PRECIP THREAT ACROSS THE AREA. MAIN FOCUS WILL BE HOW QUICKLY TEMPERATURES RECOVER THROUGH THE PERIOD. GENERAL WARMING TREND LOOKS TO BE IN ORDER...BUT GIVEN SOME MUCH COLDER DATA IN SREF PLUMES AM A LITTLE HESITANT TO WARM THINGS TOO MUCH AT THIS POINT. THE REGION WILL BE UNDER THE EASTERN PORTION OF AN UPPER LEVEL RIDGE OF HIGH PRESSURE AT THE BEGINNING OF THE PERIOD...WITH DRY CONDITIONS EXPECTED THROUGH DAYTIME WEDNESDAY. A SHORTWAVE TROUGH WILL APPROACH THE REGION ON WEDNESDAY NIGHT AND MOVE OVER THE REGION DURING THE DAYTIME ON THURSDAY. GIVEN THE INSTABILITY EXPECTED DURING THIS PERIOD...HAVE INCLUDED MENTION OF THUNDERSTORMS WITH THE SLIGHT CHANCE OF PRECIPITATION...THOUGH CONVECTIVE INHIBITION IS STILL FAIRLY STRONG OVER MUCH OF THE AREA DURING THIS TIME. THE UPPER LEVEL FLOW WILL BEGIN TO BECOME MORE ZONAL BY THE END OF THE PERIOD AS THE UPPER RIDGE MOVES EASTWARD...AND ANOTHER SHORTWAVE TROUGH BEGINS TO APPROACH THE REGION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1013 PM MDT FRI MAY 11 2012 PERSISTENT AREA OF RAIN SHOWERS IN NORTHEAST COLORADO WILL GRADUALLY WORK INTO NORTHWEST KANSAS AND SOUTHWEST NEBRASKA OVERNIGHT AND INTO SATURDAY MORNING. CURRENT RADAR TRENDS AND LATEST MODEL GUIDANCE SUGGEST AN INCREASING RISK OF MVFR CEILINGS AND LIGHT RAIN AT KGLD DURING THAT TIME PERIOD. ACTIVITY WILL PROBABLY STAY WEST OF KMCK BUT WILL GET CLOSE THERE AS WELL. BY SATURDAY AFTERNOON SHOWERS EXPECTED TO END AND CEILINGS IMPROVE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JRM LONG TERM...JRM/CJS AVIATION...024
AREA FORECAST DISCUSSION
NWS CARIBOU ME
958 PM EDT SUN MAY 13 2012 .SYNOPSIS... A STALLED FRONTAL BOUNDARY WILL WEAKEN ACROSS DOWNEAST AREAS THROUGH MONDAY. A DISTURBANCE WILL THEN CROSS THE REGION TUESDAY. UNSETTLED CONDITIONS WILL PERSIST ACROSS THE REGION THROUGH MID WEEK. && .NEAR TERM /THROUGH MONDAY/... 930 PM UPDATE: LATEST RADAR IMAGERY SHOWS SHWRS LINGERING ACROSS E CNTRL AND DOWNEAST PTNS OF THE FA OVRNGT WHERE WE HAD TO INCREASE POPS TO HI CHC CATEGORY. ALTHOUGH LGTNG DETECTION SHOWS NO CG STROKES IN OR NEAR OUR FA ATTM...WE ADDED ISOLD TSTMS IN CASE OF A RUMBLE OF IN CLD THUNDER WITH RAIN REFS GREATER THAN 35 DBZ. WE INCREASED QPF FOR THE 00-06Z PD ALG THE MAX POP AXIS TO 0.15 INCHES...WITH LOCALLY HIGHER AMTS POSSIBLE WITH A FEW HEAVIER DOWNPOURS. MOST MODELS INDICATE SHWRS SUPPOSEDLY ALREADY ENDED BY THIS TM...WITH ONLY THE HRRR MODEL CONTG SHWRS TIL ABOUT 04-05Z WITH LESS CVRG ATTM THAN SHOWN IN REAL TM. OTHERWISE...WE LOADED 01Z OBSVD SFC TEMPS WHICH INDICATED SIG COOLING OVR DOWNEAST AREAS THAN INDICATED BY THIS TM BY PRIOR UPDATES...LIKELY A RESULT OF THE FRONT MAKING A LITTLE MORE PROGRESS TOWARD THE COASTLINE. LASTLY...11-3.9 LOW CLD SAT IMAGERY INDICATES THE BACK EDGE OF LOW CLDS CURRENTLY JUST W OF A FRENCHVILLE AIRPORT...CLAYTON LAKE LINE HAS NOT MADE MUCH PROGRESS ACROSS NW ME OVR THE LAST 2 TO 3 HRS...LIKELY DUE TO WEAKENING ADVCN AS LLVL WIND BECOME NEAR CALM. WITH TRAPPED LLVL MOISTURE OVR THE FA FROM EARLIER SHWRS...LOW CLDS MAY REMAIN OVR MUCH OF THE N THRU ERLY MORN HRS. 600 PM UPDATE: RADAR CONTS TO SHOW MOST OF THE SHWR ACTIVITY ACROSS NRN AND CNTRL PTNS OF THE FA SLOWLY EXITING THE FA ERLY THIS EVE. RADAR ALSO SHOWS ISOLD SHWRS WITH OCNL CG LGTNG STROKES FROM WRN ME MOVG TOWARD DOWNEAST AREAS OF OUR FA...BUT WITH NO LGTNG ATTM... SO WE BROUGHT ISOLD SHWRS TO THE COAST FOR THE REMAINDER OF THE EVE. OTHERWISE...ALTHOUGH PARTIAL CLRG IS MOVG INTO NW PTNS OF THE FA...WE ARE A LITTLE UNCERTAIN HOW QUICKLY THIS CLRG WILL GET INTO NE AND CNTRL PTNS OF THE FA OVRNGT WITH LLVL MOISTURE LEFT OVR FROM SHWRS EARLIER TDY...SO WE DELAYED BRINGING THE BACK EDGE OF OVC CONDITIONS THRU THESE PTNS OF THE FA TIL ERLY THIS MORN. LASTLY WE LOWERED OVRNGT LOWS ACROSS MSLY NRN/CNTRL PTNS OF THE BY BLENDING NAM12...REG CANGEM GFS40 AND GMOS GUIDANCE...SINCE SPCLY ACROSS NRN PTNS OF THE FA...CURRENT OBSVD TEMPS ARE NOT TO FAR FROM FCST LOWS... AND WITH SOME PROSPECT OF CLRG LATER TNGT...TEMPS DO HAVE SOME OPPORTUNITY TO FALL SPCLY OV THE NW HLF OF THE FA. ORGNL DISC: SHOWERS IN ASSOCIATION WITH A WEAK WAVE OF LOW PRESSURE WILL DIMINISH THROUGH THE LATE AFTERNOON INTO EARLY THIS EVENING. HOWEVER THE FRONT ASSOCIATED WITH THIS FEATURE WILL STALL OVER SOUTHERN PARTS OF THE ZONE FOR TONIGHT AND MONDAY. AS RESULT EXPECT MAINLY CLOUDY SKIES TONIGHT FOR AREAS DOWNEAST WITH A CLEARING TREND OCCURRING ACROSS THE NORTH. COMBINED WITH LIGHT WINDS AND MOISTURE FROM TODAY`S SHOWERS THIS WILL SET UP FAVORABLE CONDITIONS FOR FOG FORMATION. ADDED IN AREAS OF FOG FOR THE OVERNIGHT ACROSS NORTHERN SECTIONS WITH PATCHY FOG DOWNEAST. MONDAY WILL BEGIN DRY WITH SHOWERS REDEVELOPING FROM SOUTH TO NORTH BY THE AFTERNOON. HIGHS FOR MONDAY WILL RANGE FROM THE MID 60S TO NEAR 70 AND WILL BE WARMEST IN THE NORTH WHERE CLOUDS AND SHOWERS WON`T ARRIVE UNTIL LATER IN THE DAY. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... A RATHER DAMP AND UNSETTLED PTRN IS IN STORE FOR THE SHORT TERM PD... IN THE UPPER LEVELS...BROAD UPPER LONG WAVE TROF ACROSS THE ERN THIRD OF CANADA AND THE ERN US W/ SW FLOW ALOFT ACROSS OUR REGION. AN OLD STNRY BNDRY ACROSS DOWNEAST MAINE WILL INITIALLY ACT AS THE FOCUS FOR SOME PRECIP AS A WEAK UPPER SHORT WAVE LIFTS NE ALONG THIS FRONT IN THE SWRLY FLOW ALOFT. WILL CARRY LIKELY POPS DOWNEAST MON EVE INTO MON NGT W/ POPS TRAILING OFF TO CHC AFTER MIDNIGHT W/ CHC POPS CONTG ALL BUT FAR NRN AREAS INTO TUE AM. DURING THE DAY TUE... MODELS BRING A STRONGER UPPER SHORT WAVE NNEWRD W/ AN ASSOCIATED WEAK SFC LOW WHILE A COLD FRONT DROPS SEWRD ACROSS ERN ONT PROVINCE. MODELS DIVERGE SOMEWHAT ON THE TIMING OF THIS SYSTEM BUT GENERALLY EXPECT ANOTHER SURGE OF MOISTURE TO SPREAD NEWRD INTO OUR SWRN/WRN AREAS LATER TUE AND WILL INCREASE POPS TO LIKELY ALL BUT SERN AREAS BY TUE EVE. IT THEN APPEARS MOISTURE WILL OVERSPREAD THE ENTIRE FA TUE NGT AND WILL CARRY LIKELY POPS ALL AREAS AFTER MIDNIGHT TUE NGT. EXPECT A WET DAY ON WED AS THIS SYSTEM LIFTS NE ACROSS THE AREA...AHEAD OF THE APPROACHING COLD FRONT FROM THE NW. THIS FRONT WILL LIKELY ENHANCE THE RAINFALL RATES ACROSS THE REGION LATER WED. HAVE NOT ADDED MENTION OF THUNDER YET AS MOIST SRLY FLOW OFF THE OCEAN SHOULD LEAD TO RELATIVELY STABLE CONDS BUT CAN NOT RULE OUT SOME ISOLD ELEVATED CONVECTION WED AFTN SPCLY N AND W...&& .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE COLD FRONT WILL SWEEP EAST ACROSS THE REGION WEDNESDAY NIGHT WITH ANY LINGERING SHOWERS ENDING WITH THE PASSAGE OF THE FRONT. HIGH PRESSURE WILL MAKE A BRIEF RETURN THURSDAY WITH FAIR WEATHER CONDITIONS. ANOTHER COLD FRONT WILL ENTER THE REGION FROM THE NORTHWEST THURSDAY NIGHT AND INTO FRIDAY POSSIBLY BRINGING A SLIGHT CHANCE OF SHOWERS TO THE REGION LATER THURSDAY NIGHT AND FRIDAY. HIGH PRESSURE WILL BUILD IN FOR LATE WEEK AND INTO NEXT WEEKEND. && .AVIATION /22Z SUNDAY THROUGH FRIDAY/... NEAR TERM: THERE MAY BE A BRIEF REPRIEVE LATER THIS AFTERNOON INTO THIS EVENING IN THE MVFR/IFR CONDITIONS OCCURRING IN THE NORTH BEFORE FOG FORMATION OVERNIGHT RESULTS IN A RETURN TO AT LEAST MVFR CONDITIONS. AREAS IN THE SOUTH WILL REMAIN VFR THROUGH THIS EVENING WITH MVFR AND EVENTUALLY IFR CONDITIONS DEVELOPING OVERNIGHT DUE TO PATCHY FOG AND LOW CLOUDS. ALL AREAS WILL SEE CONDITIONS IMPROVE THROUGH MONDAY MORNING. SHORT TERM: GENERALLY POOR FLYING CONDS ARE EXPECTED TUE/WED IN MOIST SRLY FLOW AND WEAK SFC LOW PRES LIFTING NEWRD UP ACROSS THE REGION. IMPROVING CONDS AS SOME COOLER AND DRIER AIR MOVES IN BEHIND THIS SYSTEM LATER WED NGT AND REMAINING THRU LATE WEEK. && && .MARINE... NEAR TERM: EXPECT SOME AREAS OF FOG TONIGHT WITH SHOWERS LIKELY MONDAY. HOWEVER CONDITIONS WILL REMAIN BELOW SCA LEVELS THROUGH MONDAY. SHORT TERM: MARGINAL SCA CONDITIONS...MAINLY W/ ELEVATED SEAS...ARE POSSIBLE TUE AND WED IN PERSISTENT SRLY FLOW. VISIBILITIES WILL ALSO BE REDUCED IN FOG AND PDS OF RAIN. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...VJN SHORT TERM...KHW LONG TERM...DUDA AVIATION...VJN MARINE...VJN/KHW
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 PM EDT SAT MAY 12 2012 .SYNOPSIS... ISSUED AT 514 AM EDT SAT MAY 12 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM N CNTRL CANADA THROUGH MANITOBA AND NW ONTARIO INTO THE NRN PLAINS. A PROMINENT SHORTWAVE TROUGH WAS MOVING THROUGH NRN ONTARIO TOWARD JAMES BAY WHILE A WEAKER TRAILING SHRTWV WAS SLIDING THROUGH NRN MN. AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES NEAR JAMES BAY THROUGH NRN LOWER MI. -SHRA SUPPORTED BY 850-700 MB FGEN BEHIND THE FRONT OVER CNTRL UPPER MI WERE QUICKLY DIMINISHING AND MOVING OUT OF THE CWA. IR LOOP SHOWED CONSIDERABLE MID CLOUDS OVER THE REGION WITH CLEARING WEST OF LAKE SUPERIOR. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 514 AM EDT SAT MAY 12 2012 TODAY...EXPECT ANY LINGERING LIGHT SHOWERS OR SPRINKLES TO EXIT THE CWA BY DAYBREAK. SATELLITE TRENDS AND MODELS MID LEVEL RH FCST SUGGEST THAT SKIES SHOULD CLEAR OVER THE WEST THIS MORNING AND OVER THE SOUTHEAST EARLY THIS AFTERNOON AS THE SFC RIDGE BUILDS INTO THE REGION. A VERY DRY AIRMASS WILL SPREAD THROUGH UPPER MI WITH PWAT VALUES DROPPING TO NEAR 0.20 INCHES (30-35 PERCENT OF NORMAL). PLENTY OF SUNSHINE AND STRONG MIXING DURING THE AFTERNOON PUSHING INLAND TEMPS INTO THE MID 60S...WILL DROP RH VALUES TO AROUND 20 PERCENT. HOWEVER...NW WINDS ONLY TO AROUND 10 MPH WILL MITIGATE FIRE WX CONCERNS. TONIGHT...EVEN THOUGH THE HIGH AND DRIEST AIR WILL SAG TO THE SOUTH...FAVORABLE RADIATIONAL COOLING CONDITION SHOULD ALLOW TEMPS TO DROP TOWARD THE LOWER END OF GUIDANCE VALUES WITH INLAND READINGS INTO THE LOWER 30S. SUNDAY...WAA WITH INCREASING WRLY FLOW WILL PUSH TEMPS BACK ABOVE NORMAL WITH HIGHS IN TO THE LOWER 70S AND COOLER READINGS IN THE 60S ONLY NEAR LAKE MICHIGAN. EVEN WITH A SLIGHT INCREASE IN LOW LEVEL MOISTURE...RH VALUES ARE EXPECTED TO FALL INTO THE 20-25 PERCENT RANGE...LEADING TO CONTINUED ELEVATED FIRE DANGER. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 514 AM EDT SAT MAY 12 2012 THE PERIOD STARTS 00Z MON WITH AN AMPLIFIED 500MB RIDGE OVER THE WRN CONUS...AND A TROUGH FROM A CLOSED UPPER LOW OVER HUDSON BAY TO THE LOWER MISSISSIPPI VALLEY. LOW LEVEL FLOW WILL BE FROM THE WSW AS THE CWA WILL BE BETWEEN A SFC LOW OVER HUDSON BAY AND SFC RIDGING FROM THE CENTRAL PLAIN STATES TO LAKE HURON. WARM AIR WILL BE SPILLING IN FROM THE W...WITH 850MB TEMPS AROUND 7C OVER ERN UPPER MI...AND AROUND 11C OVER WRN LAKE SUPERIOR. A SHORTWAVE TROUGH MOVING OVER WILL HAVE LITTLE MOISTURE TO WORK WITH...AND WILL JUST INCREASE CLOUD COVER. MONDAY...LOOK FOR WARM TEMPERATURES AS 850MB TEMPS INCREASE TO A CWA AVG TEMP OF AROUND 11C. MODELS FORECAST SOUNDINGS INDICATE POTENTIAL FOR MIXING UP TO 700MB...PRODUCING HIGH TEMPS IN THE 70S. THIS WILL ALSO LEAD TO LOW DEW PTS...BUT WINDS WILL BE FAIRLY LIGHT WHICH WILL HELP REDUCE FIRE WX CONCERNS. TUESDAY LOOKS A BIT COOLER...ESPECIALLY NEAR LAKE SUPERIOR...AS MODELS SHOW A COLD FRONT MOVING ACROSS THE AREA. 850MB TEMPS ONLY DROP DOWN TO A CWA AVG OF 9C...BUT THE NWLY WIND WILL KEEP LOCATIONS NEAR LAKE SUPERIOR COOLER. 12Z/11 ECMWF AND 12Z/11 GEM SHOW LIGHT PRECIP ACCUMULATIONS OF A COUPLE TENTHS OF A INCH /AT MOST/...WHILE THE 00Z/12 GFS KEEPS MOST OF THE AREA DRY WITH THE FRONTAL PASSAGE. THE AIRMASS LOOKS DRY ENOUGH TO KEEP WIDESPREAD PRECIP AT BAY...BUT SOME CONVECTION COULD BREAK OUT INLAND AS THE FRONT PASSES. NOT CONFIDENT ENOUGH WITH PRECIP CHANCES TO GO WITH ANY POPS ABOVE LOW CHANCE. A SHORTWAVE TROUGH LOOKS TO DIVE OVER OR E OF THE CWA WED...BUT MODELS VARY ON THE TRACK...AND THEREFOR THE LOCATION OF ANY PRECIPITATION FROM THE SYSTEM. MODELS ARE IN BETTER AGREEMENT ON WED BEING A GOOD DEAL COLDER THAN TUE...AS 850MB TEMPS ARE 5-8 DEGREES COLDER. WITH UNCERTAINTY ON THE TRACK OF THE SHORTWAVE...WILL USE A CONSENSUS OF GUIDANCE. FOR THURSDAY AND FRIDAY...MODELS ARE IN GENERAL AGREEMENT IN BRINGING THE RIDGE ORIGINALLY OVER THE WRN CONUS OVER THE CWA THU INTO FRI. LOW LEVEL FLOW SHOULD GENERALLY BE FROM THE S...WITH SFC TEMPS ABOVE NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 130 PM EDT SAT MAY 12 2012 VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH THIS TAF PERIOD. CONFIDENCE IS NOT HIGH ON WHEN...HOW LONG...OR EVEN IF IWD AND CMX WILL DECOUPLE ENOUGH TO BRING WINDS LESS THAN 12KTS...SO TRENDED TOWARD DECREASING WINDS IN THE EVENING BEFORE PRESSURE GRADIENT INCREASES IN THE EARLY MORNING HOURS AND SHALLOW STABLE LAYER POTENTIALLY MIXES OUT IN THE HIGHER TERRAIN. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 514 AM EDT SAT MAY 12 2012 EXPECT NORTHWEST WINDS LATE TONIGHT INTO EARLY THIS MORNING TO REMAIN AT OR BLO 20 KTS...WITH GUSTS UP TO 25 KTS. WINDS BECOME SOUTHWESTERLY AND DIMINISH SATURDAY AFTN AND EVENING AND SHOULD GENERALLY STAY BLO 25 KTS INTO SUNDAY NIGHT WITH THE STRONGEST WINDS OCCURRING OVER WESTERN LK SUPERIOR IN A SW WIND REGIME. WINDS BECOME QUITE LIGHT...LESS THAN 15 KTS FOR MOST OF NEXT WEEK AS HIGH PRESSURE STAYS IN THE AREA. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...JLB SHORT TERM...JLB LONG TERM...TITUS AVIATION...TK MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
822 AM EDT SAT MAY 12 2012 .SYNOPSIS... ISSUED AT 514 AM EDT SAT MAY 12 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM N CNTRL CANADA THROUGH MANITOBA AND NW ONTARIO INTO THE NRN PLAINS. A PROMINENT SHORTWAVE TROUGH WAS MOVING THROUGH NRN ONTARIO TOWARD JAMES BAY WHILE A WEAKER TRAILING SHRTWV WAS SLIDING THROUGH NRN MN. AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES NEAR JAMES BAY THROUGH NRN LOWER MI. -SHRA SUPPORTED BY 850-700 MB FGEN BEHIND THE FRONT OVER CNTRL UPPER MI WERE QUICKLY DIMINISHING AND MOVING OUT OF THE CWA. IR LOOP SHOWED CONSIDERABLE MID CLOUDS OVER THE REGION WITH CLEARING WEST OF LAKE SUPERIOR. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 514 AM EDT SAT MAY 12 2012 TODAY...EXPECT ANY LINGERING LIGHT SHOWERS OR SPRINKLES TO EXIT THE CWA BY DAYBREAK. SATELLITE TRENDS AND MODELS MID LEVEL RH FCST SUGGEST THAT SKIES SHOULD CLEAR OVER THE WEST THIS MORNING AND OVER THE SOUTHEAST EARLY THIS AFTERNOON AS THE SFC RIDGE BUILDS INTO THE REGION. A VERY DRY AIRMASS WILL SPREAD THROUGH UPPER MI WITH PWAT VALUES DROPPING TO NEAR 0.20 INCHES (30-35 PERCENT OF NORMAL). PLENTY OF SUNSHINE AND STRONG MIXING DURING THE AFTERNOON PUSHING INLAND TEMPS INTO THE MID 60S...WILL DROP RH VALUES TO AROUND 20 PERCENT. HOWEVER...NW WINDS ONLY TO AROUND 10 MPH WILL MITIGATE FIRE WX CONCERNS. TONIGHT...EVEN THOUGH THE HIGH AND DRIEST AIR WILL SAG TO THE SOUTH...FAVORABLE RADIATIONAL COOLING CONDITION SHOULD ALLOW TEMPS TO DROP TOWARD THE LOWER END OF GUIDANCE VALUES WITH INLAND READINGS INTO THE LOWER 30S. SUNDAY...WAA WITH INCREASING WRLY FLOW WILL PUSH TEMPS BACK ABOVE NORMAL WITH HIGHS IN TO THE LOWER 70S AND COOLER READINGS IN THE 60S ONLY NEAR LAKE MICHIGAN. EVEN WITH A SLIGHT INCREASE IN LOW LEVEL MOISTURE...RH VALUES ARE EXPECTED TO FALL INTO THE 20-25 PERCENT RANGE...LEADING TO CONTINUED ELEVATED FIRE DANGER. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 514 AM EDT SAT MAY 12 2012 THE PERIOD STARTS 00Z MON WITH AN AMPLIFIED 500MB RIDGE OVER THE WRN CONUS...AND A TROUGH FROM A CLOSED UPPER LOW OVER HUDSON BAY TO THE LOWER MISSISSIPPI VALLEY. LOW LEVEL FLOW WILL BE FROM THE WSW AS THE CWA WILL BE BETWEEN A SFC LOW OVER HUDSON BAY AND SFC RIDGING FROM THE CENTRAL PLAIN STATES TO LAKE HURON. WARM AIR WILL BE SPILLING IN FROM THE W...WITH 850MB TEMPS AROUND 7C OVER ERN UPPER MI...AND AROUND 11C OVER WRN LAKE SUPERIOR. A SHORTWAVE TROUGH MOVING OVER WILL HAVE LITTLE MOISTURE TO WORK WITH...AND WILL JUST INCREASE CLOUD COVER. MONDAY...LOOK FOR WARM TEMPERATURES AS 850MB TEMPS INCREASE TO A CWA AVG TEMP OF AROUND 11C. MODELS FORECAST SOUNDINGS INDICATE POTENTIAL FOR MIXING UP TO 700MB...PRODUCING HIGH TEMPS IN THE 70S. THIS WILL ALSO LEAD TO LOW DEW PTS...BUT WINDS WILL BE FAIRLY LIGHT WHICH WILL HELP REDUCE FIRE WX CONCERNS. TUESDAY LOOKS A BIT COOLER...ESPECIALLY NEAR LAKE SUPERIOR...AS MODELS SHOW A COLD FRONT MOVING ACORSS THE AREA. 850MB TEMPS ONLY DROP DOWN TO A CWA AVG OF 9C...BUT THE NWLY WIND WILL KEEP LOCATIONS NEAR LAKE SUPERIOR COOLER. 12Z/11 ECMWF AND 12Z/11 GEM SHOW LIGHT PRECIP ACCUMULATIONS OF A COUPLE TENTHS OF A INCH /AT MOST/...WHILE THE 00Z/12 GFS KEEPS MOST OF THE AREA DRY WITH THE FRONTAL PASSAGE. THE AIRMASS LOOKS DRY ENOUGH TO KEEP WIDESPREAD PRECIP AT BAY...BUT SOME CONVECTION COULD BREAK OUT INLAND AS THE FRONT PASSES. NOT CONFIDENT ENOUGH WITH PRECIP CHANCES TO GO WITH ANY POPS ABOVE LOW CHANCE. A SHORTWAVE TROUGH LOOKS TO DIVE OVER OR E OF THE CWA WED...BUT MODELS VARY ON THE TRACK...AND THEREFOR THE LOCATION OF ANY PRECIPITATION FROM THE SYSTEM. MODELS ARE IN BETTER AGREEMENT ON WED BEING A GOOD DEAL COLDER THAN TUE...AS 850MB TEMPS ARE 5-8 DEGREES COLDER. WITH UNCERTAINTY ON THE TRACK OF THE SHORTWAVE...WILL USE A CONSENSUS OF GUIDANCE. FOR THURSDAY AND FRIDAY...MODELS ARE IN GENERAL AGREEMENT IN BRINGING THE RIDGE ORIGINALLY OVER THE WRN CONUS OVER THE CWA THU INTO FRI. LOW LEVEL FLOW SHOULD GENERALLY BE FROM THE S...WITH SFC TEMPS ABOVE NORMAL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 821 AM EDT SAT MAY 12 2012 VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH THIS TAF PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 514 AM EDT SAT MAY 12 2012 EXPECT NORTHWEST WINDS LATE TONIGHT INTO EARLY THIS MORNING TO REMAIN AT OR BLO 20 KTS...WITH GUSTS UP TO 25 KTS. WINDS BECOME SOUTHWESTERLY AND DIMINISH SATURDAY AFTN AND EVENING AND SHOULD GENERALLY STAY BLO 25 KTS INTO SUNDAY NIGHT WITH THE STRONGEST WINDS OCCURRING OVER WESTERN LK SUPERIOR IN A SW WIND REGIME. WINDS BECOME QUITE LIGHT...LESS THAN 15 KTS FOR MOST OF NEXT WEEK AS HIGH PRESSURE STAYS IN THE AREA. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...JLB SHORT TERM...JLB LONG TERM...TITUS AVIATION...TITUS MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 AM EDT SAT MAY 12 2012 .SYNOPSIS... ISSUED AT 514 AM EDT SAT MAY 12 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM N CNTRL CANADA THROUGH MANITOBA AND NW ONTARIO INTO THE NRN PLAINS. A PROMINENT SHORTWAVE TROUGH WAS MOVING THROUGH NRN ONTARIO TOWARD JAMES BAY WHILE A WEAKER TRAILING SHRTWV WAS SLIDING THROUGH NRN MN. AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES NEAR JAMES BAY THROUGH NRN LOWER MI. -SHRA SUPPORTED BY 850-700 MB FGEN BEHIND THE FRONT OVER CNTRL UPPER MI WERE QUICKLY DIMINISHING AND MOVING OUT OF THE CWA. IR LOOP SHOWED CONSIDERABLE MID CLOUDS OVER THE REGION WITH CLEARING WEST OF LAKE SUPERIOR. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 514 AM EDT SAT MAY 12 2012 TODAY...EXPECT ANY LINGERING LIGHT SHOWERS OR SPRINKLES TO EXIT THE CWA BY DAYBREAK. SATELLITE TRENDS AND MODELS MID LEVEL RH FCST SUGGEST THAT SKIES SHOULD CLEAR OVER THE WEST THIS MORNING AND OVER THE SOUTHEAST EARLY THIS AFTERNOON AS THE SFC RIDGE BUILDS INTO THE REGION. A VERY DRY AIRMASS WILL SPREAD THROUGH UPPER MI WITH PWAT VALUES DROPPING TO NEAR 0.20 INCHES (30-35 PERCENT OF NORMAL). PLENTY OF SUNSHINE AND STRONG MIXING DURING THE AFTERNOON PUSHING INLAND TEMPS INTO THE MID 60S...WILL DROP RH VALUES TO AROUND 20 PERCENT. HOWEVER...NW WINDS ONLY TO AROUND 10 MPH WILL MITIGATE FIRE WX CONCERNS. TONIGHT...EVEN THOUGH THE HIGH AND DRIEST AIR WILL SAG TO THE SOUTH...FAVORABLE RADIATIONAL COOLING CONDITION SHOULD ALLOW TEMPS TO DROP TOWARD THE LOWER END OF GUIDANCE VALUES WITH INLAND READINGS INTO THE LOWER 30S. SUNDAY...WAA WITH INCREASING WRLY FLOW WILL PUSH TEMPS BACK ABOVE NORMAL WITH HIGHS IN TO THE LOWER 70S AND COOLER READINGS IN THE 60S ONLY NEAR LAKE MICHIGAN. EVEN WITH A SLIGHT INCREASE IN LOW LEVEL MOISTURE...RH VALUES ARE EXPECTED TO FALL INTO THE 20-25 PERCENT RANGE...LEADING TO CONTINUED ELEVATED FIRE DANGER. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 514 AM EDT SAT MAY 12 2012 THE PERIOD STARTS 00Z MON WITH AN AMPLIFIED 500MB RIDGE OVER THE WRN CONUS...AND A TROUGH FROM A CLOSED UPPER LOW OVER HUDSON BAY TO THE LOWER MISSISSIPPI VALLEY. LOW LEVEL FLOW WILL BE FROM THE WSW AS THE CWA WILL BE BETWEEN A SFC LOW OVER HUDSON BAY AND SFC RIDGING FROM THE CENTRAL PLAIN STATES TO LAKE HURON. WARM AIR WILL BE SPILLING IN FROM THE W...WITH 850MB TEMPS AROUND 7C OVER ERN UPPER MI...AND AROUND 11C OVER WRN LAKE SUPERIOR. A SHORTWAVE TROUGH MOVING OVER WILL HAVE LITTLE MOISTURE TO WORK WITH...AND WILL JUST INCREASE CLOUD COVER. MONDAY...LOOK FOR WARM TEMPERATURES AS 850MB TEMPS INCREASE TO A CWA AVG TEMP OF AROUND 11C. MODELS FORECAST SOUNDINGS INDICATE POTENTIAL FOR MIXING UP TO 700MB...PRODUCING HIGH TEMPS IN THE 70S. THIS WILL ALSO LEAD TO LOW DEW PTS...BUT WINDS WILL BE FAIRLY LIGHT WHICH WILL HELP REDUCE FIRE WX CONCERNS. TUESDAY LOOKS A BIT COOLER...ESPECIALLY NEAR LAKE SUPERIOR...AS MODELS SHOW A COLD FRONT MOVING ACORSS THE AREA. 850MB TEMPS ONLY DROP DOWN TO A CWA AVG OF 9C...BUT THE NWLY WIND WILL KEEP LOCATIONS NEAR LAKE SUPERIOR COOLER. 12Z/11 ECMWF AND 12Z/11 GEM SHOW LIGHT PRECIP ACCUMULATIONS OF A COUPLE TENTHS OF A INCH /AT MOST/...WHILE THE 00Z/12 GFS KEEPS MOST OF THE AREA DRY WITH THE FRONTAL PASSAGE. THE AIRMASS LOOKS DRY ENOUGH TO KEEP WIDESPREAD PRECIP AT BAY...BUT SOME CONVECTION COULD BREAK OUT INLAND AS THE FRONT PASSES. NOT CONFIDENT ENOUGH WITH PRECIP CHANCES TO GO WITH ANY POPS ABOVE LOW CHANCE. A SHORTWAVE TROUGH LOOKS TO DIVE OVER OR E OF THE CWA WED...BUT MODELS VARY ON THE TRACK...AND THEREFOR THE LOCATION OF ANY PRECIPITATION FROM THE SYSTEM. MODELS ARE IN BETTER AGREEMENT ON WED BEING A GOOD DEAL COLDER THAN TUE...AS 850MB TEMPS ARE 5-8 DEGREES COLDER. WITH UNCERTAINTY ON THE TRACK OF THE SHORTWAVE...WILL USE A CONSENSUS OF GUIDANCE. FOR THURSDAY AND FRIDAY...MODELS ARE IN GENERAL AGREEMENT IN BRINGING THE RIDGE ORIGINALLY OVER THE WRN CONUS OVER THE CWA THU INTO FRI. LOW LEVEL FLOW SHOULD GENERALLY BE FROM THE S...WITH SFC TEMPS ABOVE NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 121 AM EDT SAT MAY 12 2012 EXPECT ANY LINGERING -SHRA AT SAW TO END SHORTLY AFTER TAF ISSUANCE WITH THE ARRIVAL OF DRIER AIR ASSOCIATED WITH HI PRES MOVING EWD FROM THE PLAINS. THIS HI WL BRING VFR CONDITIONS TO THE AREA TODAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 514 AM EDT SAT MAY 12 2012 EXPECT NORTHWEST WINDS LATE TONIGHT INTO EARLY THIS MORNING TO REMAIN AT OR BLO 20 KTS...WITH GUSTS UP TO 25 KTS. WINDS BECOME SOUTHWESTERLY AND DIMINISH SATURDAY AFTN AND EVENING AND SHOULD GENERALLY STAY BLO 25 KTS INTO SUNDAY NIGHT WITH THE STRONGEST WINDS OCCURRING OVER WESTERN LK SUPERIOR IN A SW WIND REGIME. WINDS BECOME QUITE LIGHT...LESS THAN 15 KTS FOR MOST OF NEXT WEEK AS HIGH PRESSURE STAYS IN THE AREA. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...JLB SHORT TERM...JLB LONG TERM...TITUS AVIATION...KC MARINE...TITUS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
242 PM EDT SAT MAY 12 2012 .SYNOPSIS... HIGH PRESSURE WILL DRIFT TO THE CAROLINA COAST TODAY WHILE A WEAK COLD FRONT PUSHES INTO THE CENTRAL GREAT LAKES. THIS COLD FRONT WILL GRADUALLY SAG ACROSS THE REGION LATE TONIGHT AND SUNDAY WITH AN INCREASE IN CLOUD COVER AND A CHANCE OF A FEW LIGHT SHOWERS. THE FRONT WILL STALL OVER OR JUST SOUTHEAST OF THE AREA SUNDAY NIGHT AND MONDAY AND BRING MORE CLOUD COVER AND A FEW SHOWERS. THIS FRONT WILL ONLY PUSH VERY SLOWLY EAST THROUGH THE MIDDLE OF NEXT WEEK WITH A CHANCE OF SHOWERS LINGERING ACROSS CENTRAL NEW YORK WHILE WESTERN NY MAY REMAIN MAINLY DRY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE CENTERED OVER THE PIEDMONT WITH A WEAK COLD FRONT WELL UPSTREAM ACROSS LAKE HURON. SHOWERS ALONG THE BOUNDARY ARE FAIRLY WELL CAPTURED BY THE HRRR AND 12Z RUNS OF THE NAM/GFS/RGEM. THIS BOUNDARY WILL BE VERY SLOW TO DRIFT SOUTH...WITH SHOWERS EXPECTED TO BE VERY SLOW TO APPROACH WESTERN NEW YORK FOR THE REMAINDER OF TODAY. ABOUT THE ONLY IMPACT FROM THIS BOUNDARY WILL BE INCREASING MID AND HIGH CLOUDS THIS AFTERNOON. OTHERWISE...THIS A QUITE WARM AIR MASS...WITH THE 12Z BUF SOUNDING SHOWING 850 MB TEMPS TO +9C. EXPECT INTERIOR SECTIONS TO RISE INTO THE UPPER 70S...WITH PORTIONS OF THE FINGER LAKES LIKELY TO REACH 80 TODAY. THE LAKE BREEZE WILL KEEP THE IMMEDIATE LAKESHORES COOLER...WITH BUFFALO METRO LIKELY TO TOP OUT IN THE UPPER 60S TO LOWER 70S DEPENDING ON PROXIMITY TO THE LAKESHORE. SPEAKING OF WINDS...THOSE SOUTHWEST WINDS WILL CONTINUE TO BE GUSTY THROUGH THIS AFTERNOON AS A BELT OF 25-35 KNOT WINDS AT 925 MB CROSSES THE LOWER LAKES DURING PEAK DAYTIME MIXING. THIS WILL ALLOW GUSTS TO REACH 30-35 MPH AT THE SURFACE FROM THE NIAGARA FRONTIER NORTHEAST TO KROC...WHICH IS THE FAVORED AREA FOR STRONGER SOUTHWEST WINDS. THE STRONGEST WINDS WILL LIKELY BE FROM NEAR THE BUF AIRPORT INTO THE EAST AND NORTHEAST SUBURBS AS THE FLOW FOLLOWS ISENTROPIC SURFACES AND ESSENTIALLY DOWNSLOPES OFF THE DOME OF COOLER/STABLE AIR OVER LAKE ERIE. THAT SAME DOME OF COOLER MORE STABLE AIR WILL KEEP WINDS SOMEWHAT LIGHTER OVER LAKE ERIE AND IN DOWNTOWN BUFFALO. FOR TONIGHT...THE WINDS WILL DIMINISH QUICKLY THIS EVENING AS THE BELT OF STRONGER 925MB WINDS WEAKENS AND DAYTIME MIXING ENDS. CLOUDS WILL CONTINUE TO THICKEN AND INCREASE FROM NORTHWEST TO SOUTHEAST IN ADVANCE OF THE WEAK FRONTAL BOUNDARY...WHICH WILL SAG SOUTH INTO THE REGION AFTER 06Z SUNDAY. MODEST MID LEVEL HEIGHT FALLS AND PVA WILL SUPPORT WEAK LARGE SCALE ASCENT...AND WEAK FRONTOGENESIS IN THE 850-700MB LAYER WILL SUPPORT SOME CONVERGENCE ALONG AND BEHIND THE SURFACE COLD FRONT. ALL OF THIS WEAK FORCING MAY BE JUST ENOUGH TO PRODUCE A FEW SCATTERED LIGHT SHOWERS LATE TONIGHT...MAINLY FROM THE NIAGARA FRONTIER EAST TO ROCHESTER AND THE NORTH COUNTRY. AMOUNTS WILL BE MINUSCULE GIVEN WEAK FORCING IN PLAY...WITH A FEW HUNDREDTHS OF AN INCH IN SPOTTY LIGHT SHOWERS. THE INCREASE IN CLOUD COVER AND SOME MIXING OVERNIGHT WILL KEEP LOWS IN THE LOWER 50S ON THE LAKE PLAINS. SOME OF THE SHELTERED SOUTHERN TIER VALLEYS WILL STILL DECOUPLE...AND CLOUDS WILL BE SLOWER TO INCREASE THERE WHICH WILL ALLOW A FEW SPOTS TO RADIATE INTO THE MID 40S. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... DURING THE COURSE OF SUNDAY...A WEAK COOL FRONT DRAPED ACROSS LAKES ERIE AND ONTARIO AT THE START OF THE DAY WILL EVER SO SLOWLY SAG SOUTH ACROSS THE CWA...WITH ITS SLOW PROGRESS DUE BOTH TO ITS NEAR PARALLEL NATURE TO THE UPPER LEVEL FLOW...AND THE DEVELOPMENT OF A WEAK WAVE OF LOW PRESSURE OVER THE TENNESSEE AND OHIO VALLEYS. THIS FRONT WILL BE RELATIVELY STARVED FOR BOTH MOISTURE AND LIFT...SO FOR MOST AREAS IT WILL ONLY BRING AN INCREASE IN CLOUD COVER AND A LOW-END CHANCE FOR SOME LIGHT SHOWERS AND/OR SPRINKLES. THE EXCEPTION TO THIS WILL COME LATER IN THE AFTERNOON ACROSS THE SOUTHERN TIER AND INTERIOR SECTIONS OF THE FINGER LAKES...WHERE THE FRONT WILL BEGIN TO INTERCEPT INCREASING AMOUNTS OF MOISTURE LIFTING NORTHEAST FROM THE OHIO VALLEY...AND MAY ALSO ENCOUNTER SOME LIMITED SURFACE-BASED INSTABILITY. THIS WILL RESULT IN A SOMEWHAT HIGHER SHOWER POTENTIAL...AND ALSO THE POSSIBILITY OF A THUNDERSTORM OR TWO. FOR THIS REASON...HAVE RAISED POPS TO HIGH CHANCE FOR THIS LATTER AREA AND TIME FRAME...AND HAVE ALSO INSERTED A LOW CHANCE OF SOME THUNDER. BY SUNDAY EVENING...A CONSENSUS OF THE 00Z NAM/GFS/GEM/ECMWF HAS THE SURFACE FRONTAL BOUNDARY TO BE DRAPED FROM WEST-CENTRAL PA NORTHEASTWARD INTO CENTRAL AND EASTERN NEW YORK...WHERE IT WILL LIKELY REMAIN IN PLACE THROUGH THE NIGHT AND MUCH OF MONDAY AS THE AFOREMENTIONED WEAK WAVE OF LOW PRESSURE LIFTS NORTHEAST ALONG THE BOUNDARY. INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE PASSING WAVE WILL RESULT IN AN INCREASING LIKELIHOOD OF SHOWERS ALONG THE BOUNDARY...THOUGH THE BEST POTENTIAL FOR THESE STILL LOOKS TO LIE JUST A LITTLE TO OUR EAST ACROSS CENTRAL AND EASTERN NY. FOR OUR CWA...WILL INDICATE A GRADIENT IN POPS...WITH PRECIP CHANCES RANGING FROM HIGH CHANCE ALONG OUR EASTERN PERIPHERY...TO LOW CHANCE OR EVEN SLIGHT CHANCE ACROSS EXTREME FAR WESTERN NEW YORK AND THE SAINT LAWRENCE VALLEY. WITH THIS INITIAL SURFACE WAVE STILL LOOKING TO LARGELY PASS OFF TO OUR EAST BY LATER MONDAY AFTERNOON OR EARLY MONDAY EVENING...HAVE CONTINUED TO INDICATE A DOWNWARD TREND IN PRECIP CHANCES MONDAY AFTERNOON...WITH JUST SOME LOW-END CHANCE POPS LINGERING ACROSS FAR EASTERN SECTIONS BY EARLY MONDAY EVENING. AFTER THAT...HAVE PRETTY MUCH HELD THESE PRECIP CHANCES IN PLACE RIGHT THROUGH MONDAY NIGHT AS THE GFS/GEM/ECMWF ALL RIDGE A NARROW WEDGE OF HIGH PRESSURE INTO FAR WESTERN NEW YORK...WHILE LIFTING A SECONDARY WAVE OF LOW PRESSURE INTO CENTRAL AND EASTERN PA/NY. DESPITE THE AFOREMENTIONED PRECIP CHANCES AND WHAT SHOULD BE RELATIVELY CLOUDY CONDITIONS...TEMPS THROUGH THIS PERIOD WILL AVERAGE CLOSE TO OR A LITTLE ABOVE AVERAGE AS A SEASONABLY MILD AIR MASS REMAINS IN PLACE ACROSS THE LOWER GREAT LAKES. 850 MB TEMPS WILL GENERALLY RANGE FROM +7C TO +8C WHICH WILL SUPPORTIVE OF HIGHS IN THE UPPER 60S/LOWER 70S BOTH DAYS...WHILE NIGHTTIME LOWS FALL INTO THE MID 40S TO LOWER 50S. && .LONG TERM /TUESDAY THROUGH FRIDAY/... ON TUESDAY...THE GFS/ECMWF ARE IN DECENT AGREEMENT THAT THE SECONDARY LOW PRESSURE WAVE WILL PASS ACROSS CENTRAL AND EASTERN NEW YORK...GENERALLY ALONG A PATH SIMILAR OR A LITTLE TO THE EAST OF ITS PREDECESSOR SUNDAY NIGHT AND MONDAY. THIS SHOULD ONCE AGAIN KEEP THE BULK OF ITS MORE WIDESPREAD SHOWER ACTIVITY TO THE EAST OF OUR CWA...THOUGH WILL KEEP SOME LOW CHANCE POPS IN PLACE AS FAR WEST AS THE GENESEE VALLEY TO COVER ITS PASSAGE. FURTHER TO THE WEST...FAR WESTERN NEW YORK WILL LIKELY REMAIN DRY AS IT WILL BE SITUATED UNDER NARROW SURFACE RIDGING BETWEEN THE AFOREMENTIONED COASTAL SYSTEM...AND THE NEXT UPPER LEVEL TROUGH/SURFACE WAVE THAT WILL BE IN THE PROCESS OF DIGGING INTO THE UPPER GREAT LAKES. THE SECONDARY COASTAL WAVE WILL THEN LIFT OUT ACROSS NEW ENGLAND DURING THE COURSE OF TUESDAY NIGHT...WITH LINGERING SHOWER CHANCES DIMINISHING ACROSS CENTRAL AND EASTERN SECTIONS IN ITS WAKE. THEREAFTER...THE MEDIUM RANGE GUIDANCE AGREES ON DIGGING THE APPROACHING UPPER TROUGH/ASSOCIATED SURFACE REFLECTION ACROSS THE LOWER LAKES REGION ON WEDNESDAY...WITH EXPANSIVE SURFACE-BASED RIDGING THEN BUILDING ACROSS THE AREA IN ITS WAKE THURSDAY AND FRIDAY ALONG WITH SLOWLY BUILDING HEIGHTS ALOFT. THIS WILL RESULT IN THE CHANCE FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY...FOLLOWED BY A RETURN TO DRY WEATHER FOR BOTH THURSDAY AND FRIDAY. AS FOR TEMPERATURES...EXPECT SEASONABLE TO SLIGHTLY ABOVE AVERAGE TEMPERATURES TO CONTINUE THROUGH TUESDAY AND WEDNESDAY WITH LITTLE IN THE WAY OF AN AIR MASS CHANGE EXPECTED THROUGH THAT TIME. SOMEWHAT COOLER TEMPS MAY THEN BRIEFLY RETURN FOR WEDNESDAY NIGHT AND THURSDAY WITH THE PASSAGE OF THE UPPER TROUGH...BEFORE READINGS RECOVER BACK TO SEASONABLE LEVELS ON FRIDAY UNDER THE BUILDING RIDGING. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... WINDS WILL BE GUSTY THROUGH THE REMAINDER OF THE AFTERNOON... ESPECIALLY AT BUF/IAG/ROC. OTHERWISE...ANY CLOUDS WILL BE HIGH...WITH VFR CONDITIONS HIGHLY LIKELY. A WEAK COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST TONIGHT. AT NIGHT...THIS BOUNDARY SHOULD NOT BE VERY ACTIVE...WITH SHOWERS EXPECTED TO BE SCATTERED IN NATURE. TIMING IS ALSO PROBLEMATIC GIVEN THE SLOW MOTION OF THE FRONT. BECAUSE THE FRONT IS WEAK...IT WILL HAVE MINIMAL IMPACT ON OPERATIONS...WITH ONLY LIGHT WINDS WITH THE BOUNDARY. ALSO...MARGINAL LOW LEVEL MOISTURE SUGGESTS THERE WILL LIKELY BE VFR CONDITIONS WITH THE FRONT...THOUGH MVFR CANNOT COMPLETELY RULED OUT. EXPECT SHOWERS TO LINGER ON SUNDAY...PERHAPS ENHANCING A BIT DURING THE AFTERNOON DUE TO DAYTIME HEATING. THE BEST CHANCE FOR SHOWERS IS AT JHW...CLOSEST TO THE BOUNDARY. OUTLOOK... SUNDAY NIGHT AND MONDAY...VFR/MVFR WITH A CHANCE OF SHOWERS. TUESDAY AND WEDNESDAY...MAINLY VFR WITH A CHANE OF A FEW SHOWERS. THURSDAY...VFR. && .MARINE... WINDS WILL VARY DUE TO LAKE INFLUENCES...WITH THE RELATIVELY COOLER WATERS ON THE LAKES ACTING AS A STABILIZING INFLUENCE. THE RESULT WILL BE GENERALLY CALMER WINDS CLOSER TO THE CENTER OF THE LAKES...WITH STRONGER WINDS ON THE IMMEDIATE SHORELINE. SOUTHWEST WINDS IN THE 10 TO 20 KNOT RANGE ON LAKE ERIE SHOULD QUICKLY DIMINISH THIS EVENING. BECAUSE OF LESSER WINDS FURTHER OFFSHORE...EXPECT WAVES TO REMAIN IN THE 2 TO 3 FOOT RANGE...BELOW SMALL CRAFT CRITERIA. OTHERWISE...A WEAK COLD FRONT WILL DROP ACROSS THE WATERS TONIGHT...FOLLOWED BY WEAK HIGH PRESSURE EARLY NEXT WEEK. THIS SHOULD RESULT IN A RELATIVELY LIGHT WINDS ON THE WATERS WHICH SHOULD LAST WELL INTO NEXT WEEK. WIND DIRECTION WILL VARY DUE TO LAKE BREEZE INFLUENCES. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...HITCHCOCK NEAR TERM...APFFEL/HITCHCOCK SHORT TERM...JJR LONG TERM...JJR AVIATION...APFFEL MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
142 PM EDT SAT MAY 12 2012 .SYNOPSIS... HIGH PRESSURE WILL DRIFT TO THE CAROLINA COAST TODAY WHILE A WEAK COLD FRONT PUSHES INTO THE CENTRAL GREAT LAKES. THIS COLD FRONT WILL GRADUALLY SAG ACROSS THE REGION LATE TONIGHT AND SUNDAY WITH AN INCREASE IN CLOUD COVER AND A CHANCE OF A FEW LIGHT SHOWERS. THE FRONT WILL STALL OVER OR JUST SOUTHEAST OF THE AREA SUNDAY NIGHT AND MONDAY AND BRING MORE CLOUD COVER AND A FEW SHOWERS. THIS FRONT WILL ONLY PUSH VERY SLOWLY EAST THROUGH THE MIDDLE OF NEXT WEEK WITH A CHANCE OF SHOWERS LINGERING ACROSS CENTRAL NEW YORK WHILE WESTERN NY MAY REMAIN MAINLY DRY. && .NEAR TERM /THROUGH TONIGHT/... SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE CENTERED OVER THE PIEDMONT WITH A WEAK COLD FRONT WELL UPSTREAM ACROSS LAKE HURON. SHOWERS ALONG THE BOUNDARY ARE FAIRLY WELL CAPTURED BY THE HRRR AND 12Z RUNS OF THE NAM/GFS/RGEM. THIS BOUNDARY WILL BE VERY SLOW TO DRIFT SOUTH...WITH SHOWERS EXPECTED TO BE VERY SLOW TO APPROACH WESTERN NEW YORK FOR THE REMAINDER OF TODAY. ABOUT THE ONLY IMPACT FROM THIS BOUNDARY WILL BE INCREASING MID AND HIGH CLOUDS THIS AFTERNOON. OTHERWISE...THIS A QUITE WARM AIR MASS...WITH THE 12Z BUF SOUNDING SHOWING 850 MB TEMPS TO +9C. EXPECT INTERIOR SECTIONS TO RISE INTO THE UPPER 70S...WITH PORTIONS OF THE FINGER LAKES LIKELY TO REACH 80 TODAY. THE LAKE BREEZE WILL KEEP THE IMMEDIATE LAKESHORES COOLER...WITH BUFFALO METRO LIKELY TO TOP OUT IN THE UPPER 60S TO LOWER 70S DEPENDING ON PROXIMITY TO THE LAKESHORE. SPEAKING OF WINDS...THOSE SOUTHWEST WINDS WILL CONTINUE TO BE GUSTY THROUGH THIS AFTERNOON AS A BELT OF 25-35 KNOT WINDS AT 925 MB CROSSES THE LOWER LAKES DURING PEAK DAYTIME MIXING. THIS WILL ALLOW GUSTS TO REACH 30-35 MPH AT THE SURFACE FROM THE NIAGARA FRONTIER NORTHEAST TO KROC...WHICH IS THE FAVORED AREA FOR STRONGER SOUTHWEST WINDS. THE STRONGEST WINDS WILL LIKELY BE FROM NEAR THE BUF AIRPORT INTO THE EAST AND NORTHEAST SUBURBS AS THE FLOW FOLLOWS ISENTROPIC SURFACES AND ESSENTIALLY DOWNSLOPES OFF THE DOME OF COOLER/STABLE AIR OVER LAKE ERIE. THAT SAME DOME OF COOLER MORE STABLE AIR WILL KEEP WINDS SOMEWHAT LIGHTER OVER LAKE ERIE AND IN DOWNTOWN BUFFALO. FOR TONIGHT...THE WINDS WILL DIMINISH QUICKLY THIS EVENING AS THE BELT OF STRONGER 925MB WINDS WEAKENS AND DAYTIME MIXING ENDS. CLOUDS WILL CONTINUE TO THICKEN AND INCREASE FROM NORTHWEST TO SOUTHEAST IN ADVANCE OF THE WEAK FRONTAL BOUNDARY...WHICH WILL SAG SOUTH INTO THE REGION AFTER 06Z SUNDAY. MODEST MID LEVEL HEIGHT FALLS AND PVA WILL SUPPORT WEAK LARGE SCALE ASCENT...AND WEAK FRONTOGENESIS IN THE 850-700MB LAYER WILL SUPPORT SOME CONVERGENCE ALONG AND BEHIND THE SURFACE COLD FRONT. ALL OF THIS WEAK FORCING MAY BE JUST ENOUGH TO PRODUCE A FEW SCATTERED LIGHT SHOWERS LATE TONIGHT...MAINLY FROM THE NIAGARA FRONTIER EAST TO ROCHESTER AND THE NORTH COUNTRY. AMOUNTS WILL BE MINUSCULE GIVEN WEAK FORCING IN PLAY...WITH A FEW HUNDREDTHS OF AN INCH IN SPOTTY LIGHT SHOWERS. THE INCREASE IN CLOUD COVER AND SOME MIXING OVERNIGHT WILL KEEP LOWS IN THE LOWER 50S ON THE LAKE PLAINS. SOME OF THE SHELTERED SOUTHERN TIER VALLEYS WILL STILL DECOUPLE...AND CLOUDS WILL BE SLOWER TO INCREASE THERE WHICH WILL ALLOW A FEW SPOTS TO RADIATE INTO THE MID 40S. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... DURING THE COURSE OF SUNDAY...A WEAK COOL FRONT DRAPED ACROSS LAKES ERIE AND ONTARIO AT THE START OF THE DAY WILL EVER SO SLOWLY SAG SOUTH ACROSS THE CWA...WITH ITS SLOW PROGRESS DUE BOTH TO ITS NEAR PARALLEL NATURE TO THE UPPER LEVEL FLOW...AND THE DEVELOPMENT OF A WEAK WAVE OF LOW PRESSURE OVER THE TENNESSEE AND OHIO VALLEYS. THIS FRONT WILL BE RELATIVELY STARVED FOR BOTH MOISTURE AND LIFT...SO FOR MOST AREAS IT WILL ONLY BRING AN INCREASE IN CLOUD COVER AND A LOW-END CHANCE FOR SOME LIGHT SHOWERS AND/OR SPRINKLES. THE EXCEPTION TO THIS WILL COME LATER IN THE AFTERNOON ACROSS THE SOUTHERN TIER AND INTERIOR SECTIONS OF THE FINGER LAKES...WHERE THE FRONT WILL BEGIN TO INTERCEPT INCREASING AMOUNTS OF MOISTURE LIFTING NORTHEAST FROM THE OHIO VALLEY...AND MAY ALSO ENCOUNTER SOME LIMITED SURFACE-BASED INSTABILITY. THIS WILL RESULT IN A SOMEWHAT HIGHER SHOWER POTENTIAL...AND ALSO THE POSSIBILITY OF A THUNDERSTORM OR TWO. FOR THIS REASON...HAVE RAISED POPS TO HIGH CHANCE FOR THIS LATTER AREA AND TIME FRAME...AND HAVE ALSO INSERTED A LOW CHANCE OF SOME THUNDER. BY SUNDAY EVENING...A CONSENSUS OF THE 00Z NAM/GFS/GEM/ECMWF HAS THE SURFACE FRONTAL BOUNDARY TO BE DRAPED FROM WEST-CENTRAL PA NORTHEASTWARD INTO CENTRAL AND EASTERN NEW YORK...WHERE IT WILL LIKELY REMAIN IN PLACE THROUGH THE NIGHT AND MUCH OF MONDAY AS THE AFOREMENTIONED WEAK WAVE OF LOW PRESSURE LIFTS NORTHEAST ALONG THE BOUNDARY. INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE PASSING WAVE WILL RESULT IN AN INCREASING LIKELIHOOD OF SHOWERS ALONG THE BOUNDARY...THOUGH THE BEST POTENTIAL FOR THESE STILL LOOKS TO LIE JUST A LITTLE TO OUR EAST ACROSS CENTRAL AND EASTERN NY. FOR OUR CWA...WILL INDICATE A GRADIENT IN POPS...WITH PRECIP CHANCES RANGING FROM HIGH CHANCE ALONG OUR EASTERN PERIPHERY...TO LOW CHANCE OR EVEN SLIGHT CHANCE ACROSS EXTREME FAR WESTERN NEW YORK AND THE SAINT LAWRENCE VALLEY. WITH THIS INITIAL SURFACE WAVE STILL LOOKING TO LARGELY PASS OFF TO OUR EAST BY LATER MONDAY AFTERNOON OR EARLY MONDAY EVENING...HAVE CONTINUED TO INDICATE A DOWNWARD TREND IN PRECIP CHANCES MONDAY AFTERNOON...WITH JUST SOME LOW-END CHANCE POPS LINGERING ACROSS FAR EASTERN SECTIONS BY EARLY MONDAY EVENING. AFTER THAT...HAVE PRETTY MUCH HELD THESE PRECIP CHANCES IN PLACE RIGHT THROUGH MONDAY NIGHT AS THE GFS/GEM/ECMWF ALL RIDGE A NARROW WEDGE OF HIGH PRESSURE INTO FAR WESTERN NEW YORK...WHILE LIFTING A SECONDARY WAVE OF LOW PRESSURE INTO CENTRAL AND EASTERN PA/NY. DESPITE THE AFOREMENTIONED PRECIP CHANCES AND WHAT SHOULD BE RELATIVELY CLOUDY CONDITIONS...TEMPS THROUGH THIS PERIOD WILL AVERAGE CLOSE TO OR A LITTLE ABOVE AVERAGE AS A SEASONABLY MILD AIR MASS REMAINS IN PLACE ACROSS THE LOWER GREAT LAKES. 850 MB TEMPS WILL GENERALLY RANGE FROM +7C TO +8C WHICH WILL SUPPORTIVE OF HIGHS IN THE UPPER 60S/LOWER 70S BOTH DAYS...WHILE NIGHTTIME LOWS FALL INTO THE MID 40S TO LOWER 50S. && .LONG TERM /TUESDAY THROUGH FRIDAY/... ON TUESDAY...THE GFS/ECMWF ARE IN DECENT AGREEMENT THAT THE SECONDARY LOW PRESSURE WAVE WILL PASS ACROSS CENTRAL AND EASTERN NEW YORK...GENERALLY ALONG A PATH SIMILAR OR A LITTLE TO THE EAST OF ITS PREDECESSOR SUNDAY NIGHT AND MONDAY. THIS SHOULD ONCE AGAIN KEEP THE BULK OF ITS MORE WIDESPREAD SHOWER ACTIVITY TO THE EAST OF OUR CWA...THOUGH WILL KEEP SOME LOW CHANCE POPS IN PLACE AS FAR WEST AS THE GENESEE VALLEY TO COVER ITS PASSAGE. FURTHER TO THE WEST...FAR WESTERN NEW YORK WILL LIKELY REMAIN DRY AS IT WILL BE SITUATED UNDER NARROW SURFACE RIDGING BETWEEN THE AFOREMENTIONED COASTAL SYSTEM...AND THE NEXT UPPER LEVEL TROUGH/SURFACE WAVE THAT WILL BE IN THE PROCESS OF DIGGING INTO THE UPPER GREAT LAKES. THE SECONDARY COASTAL WAVE WILL THEN LIFT OUT ACROSS NEW ENGLAND DURING THE COURSE OF TUESDAY NIGHT...WITH LINGERING SHOWER CHANCES DIMINISHING ACROSS CENTRAL AND EASTERN SECTIONS IN ITS WAKE. THEREAFTER...THE MEDIUM RANGE GUIDANCE AGREES ON DIGGING THE APPROACHING UPPER TROUGH/ASSOCIATED SURFACE REFLECTION ACROSS THE LOWER LAKES REGION ON WEDNESDAY...WITH EXPANSIVE SURFACE-BASED RIDGING THEN BUILDING ACROSS THE AREA IN ITS WAKE THURSDAY AND FRIDAY ALONG WITH SLOWLY BUILDING HEIGHTS ALOFT. THIS WILL RESULT IN THE CHANCE FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY...FOLLOWED BY A RETURN TO DRY WEATHER FOR BOTH THURSDAY AND FRIDAY. AS FOR TEMPERATURES...EXPECT SEASONABLE TO SLIGHTLY ABOVE AVERAGE TEMPERATURES TO CONTINUE THROUGH TUESDAY AND WEDNESDAY WITH LITTLE IN THE WAY OF AN AIR MASS CHANGE EXPECTED THROUGH THAT TIME. SOMEWHAT COOLER TEMPS MAY THEN BRIEFLY RETURN FOR WEDNESDAY NIGHT AND THURSDAY WITH THE PASSAGE OF THE UPPER TROUGH...BEFORE READINGS RECOVER BACK TO SEASONABLE LEVELS ON FRIDAY UNDER THE BUILDING RIDGING. && .AVIATION /17Z SATURDAY THROUGH WEDNESDAY/... WINDS WILL BE GUSTY THROUGH THE REMAINDER OF THIS AFTERNOON...ESPECIALLY AT BUF AND IAG. OTHERWISE...ANY CLOUDS WILL BE HIGH...WITH VFR CONDITIONS HIGHLY LIKELY. A WEAK COLD FRONT WILL SLOWLY APPROACH FROM THE NORTH TONIGHT. AT NIGHT...THIS BOUNDARY SHOULD NOT BE VERY ACTIVE...WITH SHOWERS EXPECTED TO BE SCATTERED IN NATURE. TIMING IS ALSO PROBLEMATIC GIVEN THE SLOW MOTION OF THE FRONT. BECAUSE THE FRONT IS WEAK...IT WILL HAVE MINIMAL IMPACT ON OPERATIONS...WITH ONLY LIGHT POST-FRONTAL WINDS. ALSO...MARGINAL LOW LEVEL MOISTURE SUGGESTS THERE WILL LIKELY BE VFR CONDITIONS WITH THE FRONT...THOUGH MVFR CANNOT COMPLETELY RULED OUT. EXPECT SHOWERS TO LINGER ON SUNDAY...PERHAPS ENHANCING A BIT DURING THE AFTERNOON DUE TO DAYTIME HEATING. THE BEST CHANCE FOR SHOWERS IS AT JHW...CLOSEST TO THE BOUNDARY. OUTLOOK... SUNDAY NIGHT AND MONDAY...VFR/MVFR WITH A CHANCE OF SHOWERS. TUESDAY...VFR WEST WITH VFR/MVFR EAST OF THE GENESEE VALLEY WITH A CHANCE OF SHOWERS. WEDNESDAY...MAINLY VFR WITH A CHANCE OF A FEW SHOWERS AND THUNDERSTORMS. && .MARINE... SOUTHWEST WINDS WILL INCREASE INTO THE 10-15 KNOT RANGE TODAY AS THE PRESSURE GRADIENT TIGHTENS BETWEEN DEPARTING HIGH PRESSURE OVER THE CAROLINAS AND A WEAK COLD FRONT OVER THE UPPER GREAT LAKES. WINDS MAY BRIEFLY EXCEED 15 KNOTS ON LAKE ERIE AND WESTERN LAKE ONTARIO DURING THE MID TO LATE MORNING...BUT THE WARMER AIR MASS MOVING INTO THE REGION TODAY SHOULD PROMOTE THE DEVELOPMENT OF A STABLE DOME OF LAKE COOLED AIR OVER LAKES ERIE AND ONTARIO...WHICH TYPICALLY KEEPS WINDS LIGHTER OVER THE LAKES THIS TIME OF YEAR. WITH THIS IN MIND... WILL KEEP CONDITIONS BELOW SMALL CRAFT ADVISORY CRITERIA WITH WINDS PEAKING AT A LITTLE OVER 15 KNOTS AND WAVES 2-3 FEET. WINDS WILL BE VERY LIGHT ON SUNDAY AS A WEAK COLD FRONT SLOWLY SAGS SOUTH ACROSS THE REGION AND WEAKENS THE PRESSURE GRADIENT. LIGHT WINDS AND FLAT WAVE ACTION WILL CONTINUE THROUGH THE FIRST HALF OF NEXT WEEK. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...HITCHCOCK NEAR TERM...APFFEL/HITCHCOCK SHORT TERM...JJR LONG TERM...JJR AVIATION...APFFEL MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1047 AM EDT SAT MAY 12 2012 .SYNOPSIS... HIGH PRESSURE WILL DRIFT TO THE CAROLINA COAST TODAY WHILE A WEAK COLD FRONT PUSHES INTO THE CENTRAL GREAT LAKES. THIS COLD FRONT WILL GRADUALLY SAG ACROSS THE REGION LATE TONIGHT AND SUNDAY WITH AN INCREASE IN CLOUD COVER AND A CHANCE OF A FEW LIGHT SHOWERS. THE FRONT WILL STALL OVER OR JUST SOUTHEAST OF THE AREA SUNDAY NIGHT AND MONDAY AND BRING MORE CLOUD COVER AND A FEW SHOWERS. THIS FRONT WILL ONLY PUSH VERY SLOWLY EAST THROUGH THE MIDDLE OF NEXT WEEK WITH A CHANCE OF SHOWERS LINGERING ACROSS CENTRAL NEW YORK WHILE WESTERN NY MAY REMAIN MAINLY DRY. && .NEAR TERM /THROUGH TONIGHT/... SURFACE ANALYSIS LATE THIS MORNING SHOWS HIGH PRESSURE CENTERED OVER THE PIEDMONT WITH A WEAK COLD FRONT WELL UPSTREAM ACROSS THE WESTERN GREAT LAKES. SHOWERS ALONG THE BOUNDARY ARE FAIRLY WELL CAPTURED BY THE HRRR AND 18Z RUNS OF THE NAM/GFS. THIS BOUNDARY SHOULD BE VERY SLOW TO DRIFT SOUTH...WITH ALL MODEL GUIDANCE KEEPING WESTERN NEW YORK DRY THROUGH THIS EVENING. ABOUT THE ONLY IMPACT FROM THIS BOUNDARY WILL BE INCREASING MID AND HIGH CLOUDS THIS AFTERNOON. OTHERWISE...THIS A QUITE WARM AIRMASS...WITH THE 12Z BUF SOUNDING SHOWING 850 MB TEMPS TO +9C. THIS SOUNDING SUGGESTS HIGHS MAY EVEN PUSH 80 DEGREES IN INTERIOR LOCATIONS AWAY FOR THE LAKE BREEZE...WITH HIGHS COOLER ALONG THE IMMEDIATE LAKESHORE. SPEAKING OF WINDS...THOSE SOUTHWEST WINDS WILL BECOME QUITE GUSTY TODAY AS A BELT OF 25-35 KNOT WINDS AT 925MB CROSSES THE LOWER LAKES DURING PEAK DAYTIME MIXING. THIS WILL ALLOW GUSTS TO REACH 30-35 MPH AT THE SURFACE FROM THE NIAGARA FRONTIER NORTHEAST TO KROC...WHICH IS THE FAVORED AREA FOR STRONGER SOUTHWEST WINDS. THE STRONGEST WINDS WILL LIKELY BE FROM NEAR THE BUF AIRPORT INTO THE EAST AND NORTHEAST SUBURBS AS THE FLOW FOLLOWS ISENTROPIC SURFACES AND ESSENTIALLY DOWNSLOPES OFF THE DOME OF COOLER/STABLE AIR OVER LAKE ERIE. THAT SAME DOME OF COOLER MORE STABLE AIR WILL KEEP WINDS SOMEWHAT LIGHTER OVER LAKE ERIE AND IN DOWNTOWN BUFFALO. FOR TONIGHT...THE WINDS WILL DIMINISH QUICKLY THIS EVENING AS THE BELT OF STRONGER 925MB WINDS WEAKENS AND DAYTIME MIXING ENDS. CLOUDS WILL CONTINUE TO THICKEN AND INCREASE FROM NORTHWEST TO SOUTHEAST IN ADVANCE OF THE WEAK FRONTAL BOUNDARY...WHICH WILL SAG SOUTH INTO THE REGION AFTER 06Z SUNDAY. MODEST MID LEVEL HEIGHT FALLS AND PVA WILL SUPPORT WEAK LARGE SCALE ASCENT...AND WEAK FRONTOGENESIS IN THE 850-700MB LAYER WILL SUPPORT SOME CONVERGENCE ALONG AND BEHIND THE SURFACE COLD FRONT. ALL OF THIS WEAK FORCING MAY BE JUST ENOUGH TO PRODUCE A FEW SCATTERED LIGHT SHOWERS LATE TONIGHT...MAINLY FROM THE NIAGARA FRONTIER EAST TO ROCHESTER AND THE NORTH COUNTRY. AMOUNTS WILL BE MINUSCULE GIVEN WEAK FORCING IN PLAY...WITH A FEW HUNDREDTHS OF AN INCH IN SPOTTY LIGHT SHOWERS. THE INCREASE IN CLOUD COVER AND SOME MIXING OVERNIGHT WILL KEEP LOWS IN THE LOWER 50S ON THE LAKE PLAINS. SOME OF THE SHELTERED SOUTHERN TIER VALLEYS WILL STILL DECOUPLE...AND CLOUDS WILL BE SLOWER TO INCREASE THERE WHICH WILL ALLOW A FEW SPOTS TO RADIATE INTO THE MID 40S. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... DURING THE COURSE OF SUNDAY...A WEAK COOL FRONT DRAPED ACROSS LAKES ERIE AND ONTARIO AT THE START OF THE DAY WILL EVER SO SLOWLY SAG SOUTH ACROSS THE CWA...WITH ITS SLOW PROGRESS DUE BOTH TO ITS NEAR PARALLEL NATURE TO THE UPPER LEVEL FLOW...AND THE DEVELOPMENT OF A WEAK WAVE OF LOW PRESSURE OVER THE TENNESSEE AND OHIO VALLEYS. THIS FRONT WILL BE RELATIVELY STARVED FOR BOTH MOISTURE AND LIFT...SO FOR MOST AREAS IT WILL ONLY BRING AN INCREASE IN CLOUD COVER AND A LOW-END CHANCE FOR SOME LIGHT SHOWERS AND/OR SPRINKLES. THE EXCEPTION TO THIS WILL COME LATER IN THE AFTERNOON ACROSS THE SOUTHERN TIER AND INTERIOR SECTIONS OF THE FINGER LAKES...WHERE THE FRONT WILL BEGIN TO INTERCEPT INCREASING AMOUNTS OF MOISTURE LIFTING NORTHEAST FROM THE OHIO VALLEY...AND MAY ALSO ENCOUNTER SOME LIMITED SURFACE-BASED INSTABILITY. THIS WILL RESULT IN A SOMEWHAT HIGHER SHOWER POTENTIAL...AND ALSO THE POSSIBILITY OF A THUNDERSTORM OR TWO. FOR THIS REASON...HAVE RAISED POPS TO HIGH CHANCE FOR THIS LATTER AREA AND TIME FRAME...AND HAVE ALSO INSERTED A LOW CHANCE OF SOME THUNDER. BY SUNDAY EVENING...A CONSENSUS OF THE 00Z NAM/GFS/GEM/ECMWF HAS THE SURFACE FRONTAL BOUNDARY TO BE DRAPED FROM WEST-CENTRAL PA NORTHEASTWARD INTO CENTRAL AND EASTERN NEW YORK...WHERE IT WILL LIKELY REMAIN IN PLACE THROUGH THE NIGHT AND MUCH OF MONDAY AS THE AFOREMENTIONED WEAK WAVE OF LOW PRESSURE LIFTS NORTHEAST ALONG THE BOUNDARY. INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE PASSING WAVE WILL RESULT IN AN INCREASING LIKELIHOOD OF SHOWERS ALONG THE BOUNDARY...THOUGH THE BEST POTENTIAL FOR THESE STILL LOOKS TO LIE JUST A LITTLE TO OUR EAST ACROSS CENTRAL AND EASTERN NY. FOR OUR CWA...WILL INDICATE A GRADIENT IN POPS...WITH PRECIP CHANCES RANGING FROM HIGH CHANCE ALONG OUR EASTERN PERIPHERY...TO LOW CHANCE OR EVEN SLIGHT CHANCE ACROSS EXTREME FAR WESTERN NEW YORK AND THE SAINT LAWRENCE VALLEY. WITH THIS INITIAL SURFACE WAVE STILL LOOKING TO LARGELY PASS OFF TO OUR EAST BY LATER MONDAY AFTERNOON OR EARLY MONDAY EVENING...HAVE CONTINUED TO INDICATE A DOWNWARD TREND IN PRECIP CHANCES MONDAY AFTERNOON...WITH JUST SOME LOW-END CHANCE POPS LINGERING ACROSS FAR EASTERN SECTIONS BY EARLY MONDAY EVENING. AFTER THAT...HAVE PRETTY MUCH HELD THESE PRECIP CHANCES IN PLACE RIGHT THROUGH MONDAY NIGHT AS THE GFS/GEM/ECMWF ALL RIDGE A NARROW WEDGE OF HIGH PRESSURE INTO FAR WESTERN NEW YORK...WHILE LIFTING A SECONDARY WAVE OF LOW PRESSURE INTO CENTRAL AND EASTERN PA/NY. DESPITE THE AFOREMENTIONED PRECIP CHANCES AND WHAT SHOULD BE RELATIVELY CLOUDY CONDITIONS...TEMPS THROUGH THIS PERIOD WILL AVERAGE CLOSE TO OR A LITTLE ABOVE AVERAGE AS A SEASONABLY MILD AIRMASS REMAINS IN PLACE ACROSS THE LOWER GREAT LAKES. 850 MB TEMPS WILL GENERALLY RANGE FROM +7C TO +8C WHICH WILL SUPPORTIVE OF HIGHS IN THE UPPER 60S/LOWER 70S BOTH DAYS...WHILE NIGHTTIME LOWS FALL INTO THE MID 40S TO LOWER 50S. && .LONG TERM /TUESDAY THROUGH FRIDAY/... ON TUESDAY...THE GFS/ECMWF ARE IN DECENT AGREEMENT THAT THE SECONDARY LOW PRESSURE WAVE WILL PASS ACROSS CENTRAL AND EASTERN NEW YORK...GENERALLY ALONG A PATH SIMILAR OR A LITTLE TO THE EAST OF ITS PREDECESSOR SUNDAY NIGHT AND MONDAY. THIS SHOULD ONCE AGAIN KEEP THE BULK OF ITS MORE WIDESPREAD SHOWER ACTIVITY TO THE EAST OF OUR CWA...THOUGH WILL KEEP SOME LOW CHANCE POPS IN PLACE AS FAR WEST AS THE GENESEE VALLEY TO COVER ITS PASSAGE. FURTHER TO THE WEST...FAR WESTERN NEW YORK WILL LIKELY REMAIN DRY AS IT WILL BE SITUATED UNDER NARROW SURFACE RIDGING BETWEEN THE AFOREMENTIONED COASTAL SYSTEM...AND THE NEXT UPPER LEVEL TROUGH/SURFACE WAVE THAT WILL BE IN THE PROCESS OF DIGGING INTO THE UPPER GREAT LAKES. THE SECONDARY COASTAL WAVE WILL THEN LIFT OUT ACROSS NEW ENGLAND DURING THE COURSE OF TUESDAY NIGHT...WITH LINGERING SHOWER CHANCES DIMINISHING ACROSS CENTRAL AND EASTERN SECTIONS IN ITS WAKE. THEREAFTER...THE MEDIUM RANGE GUIDANCE AGREES ON DIGGING THE APPROACHING UPPER TROUGH/ASSOCIATED SURFACE REFLECTION ACROSS THE LOWER LAKES REGION ON WEDNESDAY...WITH EXPANSIVE SURFACE-BASED RIDGING THEN BUILDING ACROSS THE AREA IN ITS WAKE THURSDAY AND FRIDAY ALONG WITH SLOWLY BUILDING HEIGHTS ALOFT. THIS WILL RESULT IN THE CHANCE FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY...FOLLOWED BY A RETURN TO DRY WEATHER FOR BOTH THURSDAY AND FRIDAY. AS FOR TEMPERATURES...EXPECT SEASONABLE TO SLIGHTLY ABOVE AVERAGE TEMPERATURES TO CONTINUE THROUGH TUESDAY AND WEDNESDAY WITH LITTLE IN THE WAY OF AN AIRMASS CHANGE EXPECTED THROUGH THAT TIME. SOMEWHAT COOLER TEMPS MAY THEN BRIEFLY RETURN FOR WEDNESDAY NIGHT AND THURSDAY WITH THE PASSAGE OF THE UPPER TROUGH...BEFORE READINGS RECOVER BACK TO SEASONABLE LEVELS ON FRIDAY UNDER THE BUILDING RIDGING. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS WILL PREVAIL FOR THE 15Z TAF CYCLE. HIGH PRESSURE WILL DRIFT TO THE CAROLINA COAST TODAY AND PROVIDE CLEAR SKIES THROUGH THE FIRST HALF OF THE DAY. MEANWHILE A WEAK COLD FRONT OVER THE UPPER MIDWEST WILL MOVE INTO THE CENTRAL GREAT LAKES AND BRING AN INCREASE IN MID/HIGH CLOUD FROM NORTHWEST TO SOUTHEAST LATER THIS AFTERNOON AND EVENING. IT WILL BECOME WINDY TODAY AS A BELT OF 30 KNOT WINDS JUST OFF THE DECK CROSSES THE LOWER LAKES REGION...WITH MUCH OF THAT MIXING DOWN THIS AFTERNOON WITH DAYTIME HEATING. THIS WILL BRING GUSTS IN THE 20-30 KNOT RANGE AT THE SURFACE...WITH THE STRONGEST WINDS EXPECTED FROM KBUF-KIAG AREA OVER TO KROC. WINDS WILL QUICKLY DIMINISH THIS EVENING AS WINDS ALOFT RELAX AND DAYTIME MIXING ENDS. THE COLD FRONT WILL APPROACH LATE TONIGHT AND EARLY SUNDAY WITH MID LEVEL CLOUDS THICKENING AND LOWERING. A FEW SCATTERED SHOWERS WILL DEVELOP ALONG AND BEHIND THE SURFACE FRONT...AND A FEW OF THESE MAY PUSH INTO KIAG-KBUF AND KART LATE TONIGHT...AND THE REMAINDER OF THE AREA ON SUNDAY. OUTLOOK... SUNDAY...MAINLY VFR WITH A CHANCE OF SHOWERS. CHANCE OF A THUNDERSTORM IN THE SOUTHERN TIER. MONDAY...VFR/MVFR WITH A CHANCE OF SHOWERS. TUESDAY...VFR WEST WITH VFR/MVFR EAST OF THE GENESEE VALLEY WITH A CHANCE OF SHOWERS. WEDNESDAY...MAINLY VFR WITH A CHANCE OF A FEW SHOWERS AND THUNDERSTORMS. && .MARINE... SOUTHWEST WINDS WILL INCREASE INTO THE 10-15 KNOT RANGE TODAY AS THE PRESSURE GRADIENT TIGHTENS BETWEEN DEPARTING HIGH PRESSURE OVER THE CAROLINAS AND A WEAK COLD FRONT OVER THE UPPER GREAT LAKES. WINDS MAY BRIEFLY EXCEED 15 KNOTS ON LAKE ERIE AND WESTERN LAKE ONTARIO DURING THE MID TO LATE MORNING...BUT THE WARMER AIRMASS MOVING INTO THE REGION TODAY SHOULD PROMOTE THE DEVELOPMENT OF A STABLE DOME OF LAKE COOLED AIR OVER LAKES ERIE AND ONTARIO...WHICH TYPICALLY KEEPS WINDS LIGHTER OVER THE LAKES THIS TIME OF YEAR. WITH THIS IN MIND... WILL KEEP CONDITIONS BELOW SMALL CRAFT ADVISORY CRITERIA WITH WINDS PEAKING AT A LITTLE OVER 15 KNOTS AND WAVES 2-3 FEET. WINDS WILL BE VERY LIGHT ON SUNDAY AS A WEAK COLD FRONT SLOWLY SAGS SOUTH ACROSS THE REGION AND WEAKENS THE PRESSURE GRADIENT. LIGHT WINDS AND FLAT WAVE ACTION WILL CONTINUE THROUGH THE FIRST HALF OF NEXT WEEK. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...HITCHCOCK NEAR TERM...APFFEL/HITCHCOCK SHORT TERM...JJR LONG TERM...JJR AVIATION...APFFEL/HITCHCOCK MARINE...APFFEL/HITCHCOCK EQUIPMENT...HITCHCOCK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
930 PM EDT SUN MAY 13 2012 .SYNOPSIS... A SURFACE LOW PRESSURE SYSTEM OVER THE GULF STATES WILL MOVE SLOWLY ALONG THE APPALACHIANS THROUGH MIDWEEK. THE ASSOCIATED COLD FRONT WILL MOVE VERY SLOWLY EASTWARD OVER THE CAROLINAS LATE MONDAY THROUGH WEDNESDAY... RESULTING IN AN EXTENDED PERIOD OF UNSETTLED WEATHER. && .NEAR TERM /THROUGH TONIGHT/... AS OF 925 PM SUNDAY... FOR THE REST OF TONIGHT: THE MID LEVEL TROUGH AXIS EXTENDS FROM LAKE HURON THROUGH INDIANA TO THE LOWER OH VALLEY AND MS THIS EVENING... AND NUMEROUS MINOR PERTURBATIONS CONTINUE TO TRACK UP THE EAST SIDE OF THE TROUGH THROUGH WRN/CENTRAL NC. THIS WEAK BUT PERSISTENT DPVA AND A SUBTLE DISSIPATING POCKET OF UPPER DIVERGENCE AS WELL AS DEEPENING AND STRENGTHENING ISENTROPIC UPGLIDE THROUGH 295K-310K ACTING ON COPIOUS MOISTURE (PRECIPITABLE WATER HAS RISEN FROM JUST BELOW NORMAL TO NEARLY 150% OF NORMAL SINCE THIS MORNING) HAS PRODUCED WIDESPREAD LIGHT RAIN AND DRIZZLE OVER CENTRAL NC SINCE LATE AFTERNOON... PARTICULARLY ON THE WESTERN PIEDMONT. THIS LIGHT RAIN/DRIZZLE AREA... COINCIDENT WITH ONE PARTICULAR BETTER-DEFINED MID LEVEL WAVE... WILL CONTINUE TO MOVE TOWARD THE NNE OVER THE NEXT SEVERAL HOURS... AND WILL LIKELY BE FOLLOWED BY A BREAK IN STEADY PRECIP FROM SSW TO NNE OVERNIGHT... AS NOTED ON THE HRRR MODEL WHICH IS HANDLING THE CURRENT PRECIP WELL. BUT WITH STEADY ADVECTION IN THE LOWEST 3 KM OF WARM AND VERY MOIST AIR... AND CONVERGENT FLOW AT 850 MB THROUGH THE CENTRAL CAROLINAS EVIDENT ON 00Z UPPER AIR ANALYSES... THE CHANCES FOR MORE PRECIP OVERNIGHT ARE QUITE HIGH... ESPECIALLY OVER THE WESTERN PIEDMONT GIVEN MODEL INDICATIONS OF SUBSTANTIAL LOW LEVEL MOISTURE TRANSPORT CONTINUING IN THIS AREA THROUGH DAYBREAK. NOT OVERLY CONCERNED ABOUT MUCH THUNDER TONIGHT CONSIDERING THE LACK OF MID LEVEL HEIGHT FALLS AND WEAKENING UPPER LEVEL WIND FIELD... PLUS THE DEEP LAYER SHEAR IS VERY WEAK AS ARE THE LOW- AND MID-LEVEL LAPSE RATES. BUT CONSIDERING THE INCOMING PUNCH OF MID LEVEL DRY AIR NOTED ON WATER VAPOR IMAGERY AND 00Z SOUNDINGS FROM THE DEEP SOUTH AND WESTERN GULF COAST... POCKETS OF BETTER (YET STILL VERY MODEST) DESTABILIZATION REMAIN POSSIBLE AND THE RISK OF ISOLATED THUNDER WILL BE RETAINED OVERNIGHT. WITH THE LIGHT NATURE OF THE PRECIP SO FAR AND EXPECTED SPOTTY NATURE OF ADDITIONAL SHOWERS AND ISOLATED STORMS OVERNIGHT... HAVE CUT BACK FORECAST PRECIP AMOUNTS THROUGH DAWN TO NO MORE THAN A THIRD OF AN INCH WEST TO JUST A FEW HUNDREDTHS EAST... ALTHOUGH THE THREAT OF HEAVIER RAIN ON MONDAY STILL APPEARS ON TRACK. EXPECT NEARLY STEADY TEMPS IN THE 60-65 RANGE OVER MUCH OF THE AREA FOR THE REST OF THE NIGHT. -GIH && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 235 PM SUNDAY... MONDAY AND MONDAY NIGHT: BROAD UPPER-LEVEL TROUGH IN PLACE FROM THE GREAT LAKES TO THE LOWER MS VALLEY WILL GET REINFORCED BY SHORTWAVE TROUGH DIVING SOUTHEAST ALONG THE SOUTHERN ROCKIES AND INTO THE SOUTHERN PLAINS ON MONDAY. MEANWHILE...WEAK FRONTAL ZONE AND ASSOCIATED WAVE OF LOW PRESSURE OVER THE SOUTHERN APPALACHIANS WILL INCH SLOWLY EASTWARD INTO THE WESTERN CAROLINAS THROUGH MONDAY NIGHT. SHORTWAVE ENERGY IS EXPECTED TO EJECT EAST-NORTHEASTWARD ACROSS THE AREA IN THE SWLY FLOW ALOFT DOWNSTREAM OF THE BROAD TROUGH AND WITHIN THE ANOMALOUSLY HIGH (2 STD ABOVE NORMAL)PWAT AIRMASS LYING ALONG AND EAST OF THE WEAK FRONTAL ZONE ACROSS WESTERN NC. DAYTIME HEATING OF THE MOIST BOUNDARY LAYER WILL SUPPORT NUMEROUS TO WIDESPREAD SHOWERS/TSTMS MONDAY AFTERNOON/EVENING...WITH AN AXIS OF MODERATE TO HEAVY RAINFALL NOT BUDGING VERY MUCH...CENTERED ALONG AND ON THE EASTERN SLOPES OF THE APPALACHIANS AND POTENTIALLY EXTENDING EAST INTO THE WESTERN PIEDMONTS OF NC AND VIRGINIA. WHILE THERE REMAINS SOME UNCERTAINTY WRT TO THE TIMING OF THE EMBEDDED SHORTWAVE IMPULSES...MODEL CONSENSUS INDICATES THAT THE HEAVY RAINFALL AXIS AND HIGHEST WILL SHIFT EASTWARD MONDAY NIGHT...REACHING THE COASTAL SECTIONS BY DAYBREAK TUESDAY. SEVERE WEATHER THREAT: WHILE MOIST ADIABATIC PROFILES WILL SUPPORT WEAK MID-LEVEL LAPSE RATES AND INSOLATION SHOULD BE GREATLY IMPEDED BY WIDESPREAD CLOUDS...MODELS STILL SUGGEST THE POTENTIAL FOR WEAK TO MODERATE DESTABILIZATION COULD DEVELOP MONDAY AFTERNOON. UNIDIRECTIONAL SWLY FLOW OF 25-30 KT COULD SUPPORT A CLUSTER OR TWO OF STRONG TO SEVERE THUNDERSTORMS THAT COULD PRODUCE DAMAGING WET MICROBURSTS. WITH LOSS OF DAYTIME HEATING ...THE THREAT OF SEVERE WEATHER SHOULD BE ON THE WANE MONDAY NIGHT AS THE AIRMASS COOLS/STABILIZES. HEAVY RAIN THREAT: WHILE IT WILL GREATLY DEPEND ON HOW MUCH RAINFALL WE SEE THIS AFTERNOON AND TONIGHT...THE WESTERN PIEDMONT/TRIAD AREA COULD POTENTIALLY ADD ANOTHER 1 TO 2 INCHES MONDAY AND MONDAY NIGHT TO WHATEVER WE SEE TONIGHT. 3 HOUR FLASH FLOOD GUIDANCE TODAY FOR THOSE AREAS ARE AROUND 3.0"...BUT IF WE RECEIVE AN INCH OF RAIN TONIGHT...IT SHOULD LOWER THE GUIDANCE SIGNIFICANTLY...CLOSE TO THE TWO INCH THRESHOLD. LATER SHIFTS MAY NEED TO CONSIDER A FLASH FLOOD WATCH FOR THE WESTERN PIEDMONT MONDAY AFTERNOON/MONDAY NIGHT. EAST OF THE TRIAD...EXPECT AVERAGE RAINFALL AMOUNTS OF 0.50-1.0"... WITH ONLY LOCALIZED/URBAN FLOODING EXPECTED. TEMPERATURES: HIGHS MONDAY WILL DEPEND ON SHOWER/STORM COVERAGE AND WHETHER WE WILL MANAGE TO SEE ANY BREAKS IN THE EAST. AFTERNOON HIGHS RANGING FROM AROUND 70 WEST TO AROUND 80 EAST. LOWS MONDAY NIGHT AGAIN IN THE 60S. -CBL TUESDAY AND TUESDAY NIGHT: ONGOING SHOWERS AND STORMS TUESDAY MORNING SHOULD BE MOVING INTO THE COASTAL PLAIN AS THE AXIS OF DEEPEST MOISTURE FINALLY SHIFTS TOWARD THE COAST. HOWEVER...THE WEAK SURFACE FRONT IS FORECAST LINGER BACK TO THE WEST ALONG THE MOUNTAINS WHILE THE UPPER TROUGH ENERGY CONTINUES TO EVOLVE WEST OF THE MOUNTAINS....EVENTUALLY PUSHING INTO THE AREA TUESDAY EVENING. WITH SLIGHTLY DRIER AIR FORECAST TO OVERSPREAD CENTRAL NC...SOME BREAKS IN CLOUD COVER AND STRONGER DESTABILIZATION ARE EXPECTED. AHEAD OF THE UPPER TROUGH... THE MAY CONTINUE TO BE SUBTLE DISTURBANCES ALOFT MOVING ACROSS THE PERSISTENT WARM AND MOIST AIRMASS...LEADING TO A SCATTERED SHOWERS AND STORMS BY TUESDAY AFTERNOON. THE NAM IS STRONGEST AND SHOWING A STOUT VORT MAX LIFTING ACROSS THE AREA DURING PEAK HEATING. A TIGHTER HEIGHT FIELD ASSOCIATED WITH THIS FEATURE LEADS TO STRONGER DEEP LAYER SHEAR FORECAST BY THE NAM...BUT THE NAM SEEMS TO BE OVERDONE. THE GFS AND ECMWF SHOW MORE A MORE DIFFUSE WAVE AND ONLY 20-25KT OF 0-6KM BULK SHEAR...WHICH IS SUPPORTED BY MOST SREF MEMBERS. THERE IS CONSIDERABLE SPREAD AMONG SREF MEMBERS REGARDING INSTABILITY...BUT MODIFIED GFS SOUNDINGS FOR TEMPS IN THE UPPER 70S TO LOWER 80S AND DEWPOINTS IN THE LOWER 60S SHOW 500-1000 J/KG OF MLCAPE. A FEW ISOLATED SEVERE STORMS MAY BE POSSIBLE...BUT IF THE UPPER WAVE IS STRONGER...AS THE NAM FORECASTS...THEN THE SEVERE POTENTIAL WILL BE GREATER. HIGHS 77-82. AS THE SURFACE FRONT AND MAIN LOW LEVEL CONVERGENCE ZONE PUSHES INTO THE CWA TUESDAY EVENING...ISOLATED SHOWERS AND STORMS MAY CONTINUE INTO THE OVERNIGHT HOURS. THE FRONT WILL CONTINUE TO BE RATHER SLOW MOVING...AND LOWS SHOULD BE FAIRLY PERSISTENT IN THE UPPER 50S TO LOWER 60S. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 310 PM SUNDAY... A SLOW MOVING...WEAK COLD FRONT IS FORECAST TO FINALLY MOVE INTO CENTRAL NC BY WEDNESDAY MORNING...AS A POSITIVELY TITLED UPPER TROUGH EXTENDING FROM THE GREAT LAKES INTO THE DEEP SOUTH BEGINS TO DRIFT EAST ACROSS THE APPALACHIANS MOUNTAINS. DEEP MOISTURE WILL BEGIN TO TREND DOWNWARD FROM WEST TO EAST AS THE TROUGH MOVES INTO THE AREA...AND THUS POPS WILL BE INCREASINGLY FOCUSED OVER THE EASTERN CWA WEDNESDAY AND THURSDAY. TEMPS SHOULD GENERALLY RUN RIGHT AROUND NORMAL (HIGHS AROUND 80 AND LOWS IN THE MID TO UPPER 50S) IF NOT A SLIGHTLY BELOW NORMAL WITH WEAK TROUGHING ALONG THE EAST COAST. THEN...AS ENERGY SWINGING ACROSS THE GREAT LAKES LEAVES THE SOUTHERN END OF THE UPPER TROUGH BEHIND...MODELS DIVERGE REGARDING HOW THE TROUGH WILL EVOLVE AS IT DRIFTS EAST TOWARD THE GA/SC COAST. THE 12Z GFS NEVER QUITE CLOSES OFF AN UPPER LOW AND ALLOWS THE TROUGH TO BE SWEPT OFF TO THE NORTHEAST AS NORTHERN STREAM ENERGY SWINGS ACROSS NEW ENGLAND. THE 00Z ECMWF HAD SHOWN A VERY INTERESTING SOLUTION WITH THE UPPER LOW DEVELOPING ALONG THE SOUTHEAST COAST AND A POSSIBLE SUBTROPICAL-LIKE LOW THAT DRIFTED NORTHWEST INTO NC/SC OVER THE WEEKEND. THE 12Z ECMWF RUN SHOWS THE UPPER LOW FURTHER OFFSHORE AND LITTLE IMPACT OVER NC. THERE IS A LOT OF SPREAD AMONG GFS AND ECWMF ENSEMBLE MEMBERS...SO CONFIDENCE IN SENSIBLE WEATHER IMPACTS NEXT WEEKEND IS LOW AT THE MOMENT....BUT WE WILL KEEP THE FORECAST DRY FOR THIS PACKAGE. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... AS OF 745 PM SUNDAY... ADVERSE AVIATION CONDITIONS ARE EXPECTED TO PERSIST THROUGHOUT THE CURRENT TAF PERIOD. A WEAK FRONT...WITH A WAVE OF LOW PRESSURE ALONG IT...WILL CONTINUE TO PROGRESS EASTWARD TOWARDS THE REGION DURING THE NEXT 24 HOURS. SEVERAL WEAK UPPER LEVEL DISTURBANCES IN THE SOUTHWESTERLY FLOW ALOFT WILL COMBINE WITH WARM...MOIST FLOW AHEAD OF THE AFOREMENTIONED FRONTAL SYSTEM TO PRODUCE PERIODS OF PRECIP THROUGH THE PERIOD. THROUGH THE OVERNIGHT HOURS...THE BEST CHANCE OF PRECIP WILL BE ACROSS THE WESTERN PORTION OF THE FORECAST AREA (KINT/KGSO)...WITH ONLY SLIGHT CHANCES FURTHER EAST. MOST MODELS DO INDICATE A LULL IN THE PRECIP AFTER 06Z...BEFORE PICKING UP AGAIN ON MONDAY. NEVERTHELESS...CIGS WILL LOWER FROM WEST TO EAST OVER THE NEST SEVERAL HOURS...WITH AN EXTENDED PERIOD OF SUB-VFR CONDITIONS LIKELY FOR ALL TAF SITES. THEN...NUMEROUS TO WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS ALL OF CENTRAL NC MONDAY WITH MVFR/IFR CONDITIONS IN HEAVY RAIN. OUTLOOK...THE SHOWERS AND THUNDERSTORMS ARE EXPECTED TO PERSIST INTO MONDAY NIGHT ACROSS THE REGION AS THE WEAK FRONT AND WAVE OF LOW PRESSURE SLOWLY MOVES INTO WESTERN NC. THE FRONT WILL BE SLOW TO MOVE EAST ACROSS CENTRAL NC TUESDAY AND INTO WEDNESDAY AND AS A RESULT AM EXPECTING PERIODS OF IFR TO MVFR CONDITIONS WITH SCATTERED SHOWERS AND THUNDERSTORMS. DRIER AIR SHOULD GRADUALLY FILTER INTO THE AREA FROM THE WEST ON THURSDAY...LEADING TO DRIER CONDITIONS FOR THE REMAINDER OF THE WEEK. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SEC/GIH NEAR TERM...HARTFIELD SHORT TERM...CBL/BLS LONG TERM...BLS AVIATION...KRR/CBL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
757 PM EDT SUN MAY 13 2012 .SYNOPSIS... A LOW PRESSURE SYSTEM APPROACHING FROM THE SOUTHWEST WILL BRING INCREASING RAIN CHANCES THIS AFTERNOON AND TONIGHT. A COLD FRONT WILL STALL NEAR THE AREA THROUGH MID WEEK BRINGING CONTINUED CHANCES FOR SHOWERS AND THUNDERSTORMS...WITH SIGNIFICANT RAINFALL POSSIBLE MONDAY INTO TUESDAY. COLD FRONT PUSHES OFFSHORE THURSDAY BRINGING DRIER CONDITIONS FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... AS OF 2 PM SUNDAY...SHOWERS REMAIN SCATTERED MAINLY OVER SOUTH CAROLINA THIS AFTERNOON WHERE RICHER DEWPOINT AIR EXISTS WITH READINGS IN THE MID 60S. DRIER AIR STILL EXISTS FROM CAPE FEAR NORTH CLOSER TO THE COAST WHERE DEWPOINT TEMPS WERE IN THE MID 50S. HIGHER HRRR CAPE VALUES ALIGNING NICELY WITH SHWR DEVELOPMENT OVER SC AND INLAND NC ZONES. CLOUD COVER MODERATING TEMPS OVERALL...ESPECIALLY WHERE PCP OCCURRED THROUGH THE DAY. MODELS STILL SHOWING SHWR DEVELOPMENT AREA SHIFTING FARTHER INLAND OVER SC MAINLY THROUGH LATE AFTERNOON WHILE COASTAL NC BECOMES SLIGHTLY DRIER. MAIN AREA OF PCP MOVING UP THROUGH GA AND SC AHEAD OF LOW TRACKING NORTH THROUGH TENNESSEE THROUGH TONIGHT. DEEPEST LAYER MOISTURE WILL REMAIN OVER INLAND SOUTH CAROLINA TRACKING INTO NC. PCP WATER VALUES WILL REACH UP AROUND 1.5 INCHES INLAND WHILE STILL REMAINING QUITE DRY FROM CAPE FEAR NORTHWARD WHERE PCP WATER VALUES REMAIN LESS THAN AN INCH CLOSER TO THE COAST. EXPECT MOST OF THE SHWR ACTIVITY TO REMAIN SOUTH AND WEST OF CWA WITH LESS IN THE WAY OF PCP ACROSS COASTAL NC THROUGH MUCH OF TONIGHT. MOISTURE PROFILES OVER LOCAL AREA SHOWING MOISTURE THINNING OUT THROUGH THE COLUMN IN THE MID LAYERS THROUGH THIS EVENING. CAN NOT RULE OUT SOME SHWRS AS SHORTWAVE ROTATES AROUND PROVIDING SOME MINOR PERTURBATIONS TO SUPPORT SOME CONVECTIVE DEVELOPMENT BUT OVERALL EXPECT MORE ISOLATED THROUGH THIS EVENING WITH BETTER CONVECTIVE DEVELOPMENT POSSIBLE LATER TONIGHT ACROSS THE PEE DEE REGION IN SOUTH CAROLINA AND ALSO ACROSS THE COASTAL WATERS. TEMPS WILL ONLY DROP INTO THE LOWER 60S MOST PLACES OVERNIGHT WITH PLENTY OF MOISTURE PRESENT AND CONSIDERABLE CLOUD COVER. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... AS OF 340 PM SUNDAY...SFC HIGH PRESSURE TO RETREAT FARTHER OFFSHORE MONDAY. THIS WILL ALLOW A SFC COLD FRONT ALBEIT WEAK...TO TRACK TO THE WESTERN CAROLINAS FROM THE GULF COAST STATES BY TUESDAY. THIS WILL OPEN UP BOTH THE GULF OF MEXICO AND ATLANTIC MOISTURE FEEDS ACROSS THE FA BY MIDDAY MONDAY...AND CONTINUE THROUGH TUESDAY NIGHT. THE BEST SHOT FOR POPS FROM CONVECTION WILL RUN FROM MONDAY AFTERNOON THROUGH DAYBREAK TUESDAY. MID-LEVEL IMPULSES ARE PROGGED TO WEAKEN AS THEY REACH AND TRACK ACROSS THE FA...NEVERTHELESS THIS WILL CONTINUE TO BE A FOCUS FOR CONVECTION DEVELOPMENT. PROGGED NAMBUFR SOUNDINGS INDICATE A NEARLY SATURATED ATM COLUMN ACROSS THE FA WITH 1.5 TO 1.9 PWS MONDAY NIGHT. COULD OBSERVE WIDESPREAD 3/4 TO 1 1/4 INCHES OF RAINFALL ACROSS THE REGION THROUGH TUESDAY DAYBREAK. THE DRY GROUNDS AND VEGETATION ACROSS THE REGION WILL ACT LIKE SPONGES. HOWEVER WILL STILL CONTINUE TO INDICATE IN THE HWO ABOUT THE POSSIBILITY OF FLOODING RAINS ACROSS ISOLATED LOCALES THAT COULD EXPERIENCE UP TO 2 INCHES OF RAINFALL. FOR TUESDAY...DIURNALLY DRIVEN CONVECTION WILL TAKE OVER WITH THE AID OF THE NEARLY STALLED SFC COLD FRONT AS A TRIGGER. UPPER LEVEL IMPULSES NOT AS PRONOUNCED THAT WILL AFFECT THE FA LATE MONDAY INTO MONDAY NIGHT. MAX/MIN TEMPS WILL HOVER WITHIN 3 DEGREES ON EITHER SIDE OF THE CLIMO NORMS. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 340 PM SUNDAY...EARLY PORTION OF THE FORECAST IS FAIRLY STRAIGHT FORWARD. BROAD TROUGHING ALOFT...WITH THE AXIS WEST OF THE AREA...RESULTS IN DEEP SOUTHWEST FLOW PARALLEL TO SURFACE BOUNDARIES STALLED IN THE AREA. TYPICALLY THIS YIELDS UNSETTLED...THOUGH NOT VERY WIDESPREAD...WEATHER. WILL BUMP POP A BIT HIGHER WED BUT STILL IN THE CHC RANGE AT THIS POINT. TIMING ANY POTENTIAL SHORTWAVES THAT COULD ENHANCE STORMS AND CREATE MORE COVERAGE AT THIS POINT IS DIFFICULT AT BEST SO FURTHER POPS REFINEMENTS...BOTH SPATIAL AND TEMPORAL...WILL BE NEEDED. POTENT SHORTWAVE OUT OF THE WEST HELPS PUSH THE UPPER TROUGH AND THE STALLED FRONT OFFSHORE WED NIGHT INTO THU. MOISTURE AND THE THREAT OF PRECIP LINGERS INTO THU WITH TROUGH AXIS/UPPER LOW OVER HEAD AND SLOW TO MOVE EAST. AT THIS POINT THE ECMWF/HPC SOLUTION DIFFERS FROM THE GFS/CANADIAN SOLUTION. 00Z ECMWF AND HPC SOLUTIONS DIG THE UPPER TROUGH A BIT DEEPER OVER THE NORTHERN GOMEX WHICH RESULTS IN A SEMI-CUTOFF UPPER LOW OVER OVER GA/NORTHERN FL. THIS INDUCES A SURFACE LOW WHICH STARTS OUT COLD CORE BUT COULD BECOME A HYBRID SYSTEM AS IT MOVES NORTH ALONG THE COAST. THE 12Z GFS/CANADIAN SOLUTIONS AND A NUMBER OF THE GFS ENSEMBLE MEMBERS SUPPORT LESS AMPLIFICATION OF THE 5H TROUGH OVER THE NORTHERN GOMEX...WHICH RESULTS IN THE SYSTEM DEVELOPING MUCH FARTHER OFF THE COAST. GIVEN BOTH SOLUTIONS SHOW A SYSTEM DEVELOPING HAVE HIGH CONFIDENCE SOMETHING WILL EXIST OFF THE COAST LATE IN THE PERIOD...BUT DETAILS REMAIN FUZZY. LOW CONFIDENCE AND THE POTENTIAL FOR FORECAST FLIP-FLOPPING WILL NOT MAKE MUCH IN THE WAY OF CHANGES BEYOND THU...KEEPING INHERITED SLIGHT CHC POP. TEMPERATURES WILL BE WITHIN A DEGREE OR TWO OF CLIMO THROUGH THE PERIOD. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... AS OF 00Z...PERIODS OF MVFR WILL CONTINUE THROUGH THE OVERNIGHT HOURS DUE TO CIGS/BRIEF FOG/ISOLATED RAINFALL...WITH MVFR BECOMING MORE CONSISTENT AFTER DAYBREAK AS LOWERED CIGS AND SHOWERS MOVE IN...WITH TSRA POSSIBLE. CANNOT RULE OUT BRIEF PERIODS OF IFR WITH HEAVIER SHOWERS AND/OR THUNDERSTORMS. OTHERWISE EXPECT VFR. CURRENT RADAR AND 11-3.9U SATELLITE IMAGERY SHOW ABUNDANT CLOUD COVER ACROSS THE AREA WITH ISOLATED LIGHT SHOWERS INLAND...ALL AHEAD OF A LOW PRESSURE SYSTEM TO THE SOUTHWEST. ANTICIPATE ANY LINGERING LIGHT RAIN TO TAPER OFF WITHIN THE NEXT HOUR OR TWO...WITH PERIODS OF MVFR EXPECTED. HAVE INTRODUCED MVFR FOG AT KFLO FOR POSSIBLE ADVECTION FOG. WINDS OVERNIGHT WILL BE LIGHT AND VARIABLE. AFTER SUNRISE...LOW LEVEL CLOUDS WILL INCREASE IN OPACITY AND RAIN WILL FILL IN ACROSS THE AREA. AS AFOREMENTIONED...CANNOT RULE OUT BRIEF PERIODS OF IFR WITH HEAVIER SHOWERS AND/OR THUNDERSTORMS THROUGHOUT THE DAY. SOUTH-SOUTHEAST WINDS AOB 10 KTS THROUGHOUT THE MORNING WILL INCREASE THROUGHOUT THE AFTERNOON...WITH GUSTS NEAR 20 KTS POSSIBLE. CHANCES FOR TSRA WILL INCREASE INTO EARLY AFTERNOON...THOUGH CONFIDENCE IS LOWERED GIVEN WEAK ANTICIPATED INSTABILITY. EXTENDED OUTLOOK...UNSETTLED WEATHER THROUGH THE PERIOD WITH A GOOD CHANCE FOR SHOWERS/ISOLATED THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 2 PM SUNDAY...LATEST BUOY OBS SHOWING SEAS 2 TO 3 FT THIS MORNING BUT UP TO 4 FT JUST SOUTH AND EAST OF LOCAL WATERS. SOUTHEAST WINDS UP AROUND 15 KTS WILL CONTINUE AS GRADIENT TIGHTENS BETWEEN DEVELOPING LOW PRESSURE OVER TENNESSEE AND HIGH PRESSURE WELL OFF THE NORTH CAROLINA COAST. WINDS WILL VEER SLIGHTLY THROUGH TONIGHT BECOMING MORE NORTHERLY AS LOW TRACKS FARTHER NORTH AND EAST. THIS PERSISTENT ON SHORE FLOW THROUGH TONIGHT WILL BUILD SEAS UP TO 3 TO 4 FT WITH SOME 5 FTERS IN OUTER WATERS. THE BEST CHANCE OF SHOWER ACTIVITY WILL REMAIN ACROSS THE SC WATERS...REMAINING ISOLATED THROUGH MOST OF THE NIGHT WITH POSSIBLE REDEVELOPMENT LATER TONIGHT. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 350 PM SUNDAY...HIGH PRESSURE TO RETREAT FURTHER OFFSHORE AND THE HIGH SEAS THROUGH THE PERIOD. SFC COLD FRONT TO SLOWLY PUSH TO THE WATERS BY THE END OF THE PERIOD. THIS OPENS UP A SSE TO SSW WIND DIRECTION MONDAY INTO TUESDAY. THE TIGHTENED SFC PG WILL OCCUR MONDAY INTO EARLY TUESDAY...BEFORE RELAXING AS THE FRONTAL BOUNDARY TURTLES ITS WAY EASTWARD BEFORE STALLING JUST INLAND FROM THE COAST BY EARLY WEDNESDAY. WINDS WILL BE AT THEIR PEAK LATE MONDAY INTO MONDAY NIGHT...WITH SPEEDS 15 TO 20 KT. AN ESE GROUND SWELL AT 7-8 SECOND PERIODS WILL COMBINE WITH LOCALLY PRODUCED 3 TO 5 SECOND PERIOD WIND WAVES...TO PRODUCE 3 TO 5 FT SEAS. A FEW 6 FOOTERS REMAIN POSSIBLE ESPECIALLY THE OUTER WATERS OFF CAPE FEAR AND CAPE ROMAIN. THE TIME FRAME FOR THIS OCCURRENCE...MONDAY AFTERNOON INTO TUESDAY NIGHT. NOT ALL THAT CONVINCED THAT SCA CRITERIA WILL BE MET FOR ANY LENGTH OF TIME. HOWEVER SCEC THRESHOLDS WILL BE MET AND LIKELY RAISED TONIGHT OR MONDAY UNLESS FUTURE MODEL RUNS INDICATE INCREASED OCCURRENCE FOR SCA CRITERIA. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 340 PM SUNDAY...SOUTHWEST FLOW OVER THE WATERS WED WITH FRONT STALLED VERY CLOSE TO THE COAST. PROXIMITY TO THE BOUNDARY WILL KEEP SOUTHWEST FLOW 10 KT OR LESS ALL DAY. FRONT IS PUSHED OFF THE COAST LATE WED NIGHT INTO THU WITH WINDS VEERING FROM NORTHWEST IMMEDIATELY BEHIND THE FRONT TO NORTHEAST BY MID TO LATE MORNING THU. OFFSHORE FLOW STARTS OUT AROUND 10 KT BUT COLD SURGE LATE THU NIGHT WILL PUSH SPEEDS CLOSE TO 15 KT AWAY FROM SHORE. FRI COULD BE QUITE INTERESTING IF THE 00Z ECMWF/HPC SOLUTION VERIFIES. THESE SOLUTIONS BRING LOW PRESSURE...POTENTIALLY A TROPICAL HYBRID...INTO THE COASTAL WATERS LATE FRI AND KEEPS IT IN THE AREA SAT. AT THIS POINT THE EVENT LOOKS LIKE IT WOULD BE A SOLID SCA EVENT...AGAIN IN THE 00Z ECMWF/HPC SOLUTION VERIFIES. THE 12Z GFS/CANADIAN HAS THE LOW MUCH FARTHER OFF THE COAST WITH CONTINUED SOLID 15 KT NORTHEAST FLOW SAT AND SUN. FOR NOW HAVE CONTINUED NORTHEAST FLOW THROUGH THE END OF THE PERIOD WITH FURTHER ADJUSTMENTS EXPECTED AS THE CORRECT SOLUTION BECOMES MORE DEFINED. SEAS 2 TO 4 FT WITH SOME SWAN SUGGESTING A BIT OF SOUTHERLY SWELL STARTING TO DEVELOP WED. PASSAGE OF COLD FRONT AND RESULTING NORTHERLY FLOW WILL CREATE CHAOTIC 2 TO 4 FT SEAS WED NIGHT AND THU. COLD SURGE THU NIGHT WILL INCREASE SEAS FRI...3 TO 4 FT EXCEPT FOR AREAS BLOCKED TO NORTHEAST FLOW WHERE SEAS WILL BE 1 TO 2 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...DCH LONG TERM...III AVIATION...SGL
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
655 PM CDT SUN MAY 13 2012 .AVIATION... FOR THE 00Z TAFS...ONGOING SHOWERS AND THUNDERSTORMS CONTINUE TO IMPACT THE KAMA TERMINAL WHERE MODERATE TO HEAVY RAIN HAS REDUCED VISBYS DOWN TO BELOW 2 MILES BRIEFLY. CURRENT RADAR IMAGERY SHOWS STORMS SLOWLY MOVING EAST...SO EXPECT TSRA TO IMPACT KAMA THROUGH 01Z. HAVE INSERTED A TEMPO GROUP WITH MVFR VISBYS AT 2SM THROUGH THEN AS ADDITIONAL HEAVY RAINFALL CAN ACCOMPANY THESE STORMS. KDHT IS CURRENTLY REPORTING MVFR VISBYS IN LIGHT FOG WHICH SHOULD CONTINUE THIS EVENING. STORMS CONTINUE TO DEVELOP ACROSS THE EASTERN PLAINS 0F CO/NM AS UPPER LIFT PROVIDED BY AN UPPER SHORTWAVE TROUGH IN THE FOUR CORNERS AREA COMBINES WITH MOIST LOW-LEVEL UPSLOPE FLOW. HAVE CARRIED -SHRA TONIGHT AT THE TERMINALS AS THESE SHOWERS WILL CONTINUE TO MOVE TO THE EAST. OUTSIDE OF ANY STRONGER SHOWER THAT MAY PRODUCE MODERATE OR HEAVY RAINFALL THAT CAN REDUCE BRIEFLY REDUCE VISBYS...EXPECT VFR CONDITIONS THROUGH THE TAF FORECAST PERIOD. THE UPPER SHORTWAVE TROUGH IS EXPECTED TO CONTINUE TO DROP SOUTH AND MOVE INTO WEST TX BY MONDAY AFTERNOON. THUS EXPECT -SHRA MONDAY MORNING AND AFTERNOON WITH SKIES THINNING TOWARD THE END OF THE FORECAST PERIOD...PARTICULARLY AT KGUY/KDHT. CLK && .PREV DISCUSSION... /ISSUED 332 PM CDT SUN MAY 13 2012/ DISCUSSION... PRIMARY FOCUS IS ON PRECIPITATION CHANCES THROUGH MONDAY. AFTERNOON WATER VAPOR IMAGERY SHOWED A MID/UPPER-LEVEL SHORTWAVE TROUGH SINKING SOUTHEAST ACROSS EASTERN UT TOWARDS THE FOUR CORNERS REGION. MID TO UPPER-LEVEL FORCING AHEAD OF THIS SHORTWAVE HAS COMBINED WITH DAYTIME HEATING/DESTABILIZATION AND LOW-LEVEL UPSLOPE FLOW OVER EASTERN CO AND NM TO GENERATE SHOWERS AND THUNDERSTORMS. THE GREATEST CONVECTIVE COVERAGE IS CURRENTLY ACROSS NORTHEAST NM WORKING INTO THE SOUTHWEST TX PANHANDLE...BUT ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED FARTHER EAST ACROSS THE PANHANDLES DUE TO THE COMBINATION OF AFTERNOON DESTABILIZATION AND BROADER SCALE LIFT AHEAD OF THE SHORTWAVE. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO IMPACT THE AREA THIS EVENING AND OVERNIGHT. THE MID/UPPER-LEVEL SHORTWAVE TROUGH WILL CONTINUE TO DIVE SOUTHEAST...REACHING NORTHERN/CENTRAL NM BY EARLY MONDAY MORNING. DIFFLUENT/DIVERGENT FLOW ALOFT AHEAD OF THIS WAVE WILL CONTINUE TO SUPPORT CONVECTION PROPAGATING EAST/SOUTHEAST OUT OF NM AND CO THIS EVENING AND OVERNIGHT. BEST DYNAMICS WILL BE FOCUSED ACROSS THE SOUTHWEST HALF OF THE AREA AND HAVE ALIGNED POPS ACCORDINGLY. ALSO SOME WEAK ISENTROPIC LIFT EVIDENT ON THE 305K THETA SURFACE ACROSS THE SOUTHWEST TX PANHANDLE THIS EVENING TO FURTHER AID CONVECTION. LATEST LAPS AND RUC ANALYSIS DATA SHOW MLCAPES IN THE 500-1000 J/KG RANGE ACROSS THE WESTERN PANHANDLES WITH LESSER VALUES TO THE EAST AND DEEP LAYER SHEAR AROUND 30-35 KTS IN THE SOUTHWEST TX PANHANDLE...DECREASING TO THE NORTHEAST. THUS COULD SEE A FEW STRONG STORMS THROUGH THIS EVENING CAPABLE OF PRODUCING SMALL HAIL AND GUSTY WINDS...BUT NOT REALLY ANTICIPATING ANY SEVERE WEATHER /ALTHOUGH AN ISOLATED MARGINALLY SEVERE STORM ACROSS THE SOUTHWEST CAN/T BE RULED OUT/. COULD ALSO SEE SOME LOCALLY HEAVY RAIN GIVEN PWATS IN THE THREE QUARTERS OF AN INCH TO ONE INCH RANGE AND SOME TRAINING OF STORMS POSSIBLE. BETTER RAIN CHANCES LOOK TO GRADUALLY SHIFT SOUTH/SOUTHWEST OF THE AREA LATE TONIGHT IN ASSOCIATION WITH STRONGER DIVERGENCE ALOFT...AND ALSO AS THE LLJ AND LOW-LEVEL ISENTROPIC LIFT FOCUS TO OUR SOUTHWEST. RAIN CHANCES LINGER INTO MONDAY...BUT WILL GRADUALLY END FROM NORTH TO SOUTH THROUGH THE DAY AS THE SHORTWAVE CONTINUES TO DIVE SOUTHEAST TO SOUTHEAST NM/SOUTHWEST TX BY EARLY MONDAY EVENING. BETTER RAIN CHANCES WILL BE FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA ON MONDAY. WEAKER INSTABILITY AND SHEAR SHOULD PRECLUDE ANY STRONG OR SEVERE STORMS. WILL ALSO SEE THE COOLEST TEMPS IN THE SOUTH ON MONDAY DUE TO LINGERING CLOUDS/PRECIP...WITH HIGHS FORECAST TO RANGE FROM THE UPPER 60S SOUTHWEST TO MID/UPPER 70S NORTH. DRY CONDITIONS ARE THEN FORECAST BEGINNING MONDAY NIGHT AS SHORTWAVE UPPER RIDGING BUILDS EAST ACROSS THE SOUTHERN AND CENTRAL ROCKIES. TEMPS WILL BEGIN TO REBOUND ON TUESDAY DUE TO RISING HEIGHTS...A RETURN OF WEAK SOUTHERLY WINDS...AND INCREASED SUNSHINE...WITH HIGHS CLIMBING BACK INTO THE UPPER 70S TO LOWER 80S. A DAMPENING MID-LEVEL SHORTWAVE WILL WORK ACROSS THE CENTRAL ROCKIES AND PLAINS WEDNESDAY AND WEDNESDAY NIGHT. THIS COULD POTENTIALLY SPAWN A FEW SHOWERS/THUNDERSTORMS ACROSS THE NORTHERN PANHANDLES WEDNESDAY NIGHT. HOWEVER...CHANCES LOOK LOW AT THIS TIME AS BETTER DYNAMICS WILL STAY TO OUR NORTH AND COME ACROSS AT NIGHT...BY WHICH TIME ELEVATED INSTABILITY LOOKS MINIMAL. THUS KEPT A DRY FORECAST FOR NOW. THE LEE TROUGH WILL DEEPEN ON WEDNESDAY...WITH RESULTANT BREEZY SOUTHWEST WINDS FURTHER CONTRIBUTING TO THE WARM UP. A ZONAL FLOW/BROAD FLAT RIDGING LATE THIS WEAK WILL TRANSITION TO SOUTHWESTERLY OVER THE WEEKEND AS AN UPPER TROUGH WORKS ACROSS THE INTERMOUNTAIN WEST AND ROCKIES EVENTUALLY INTO THE NORTHERN PLAINS. THIS FLOW ALOFT WILL PROMOTE SURFACE LEE TROUGHING AND SOME SHARPENING OF THE DRYLINE BY FRIDAY AND SATURDAY. HOWEVER IT CURRENTLY LOOKS LIKE WARM TEMPS ALOFT AND A LACK OF UPPER FORCING /AS THE TROUGH IS DEFLECTED WELL TO OUR NORTHWEST/ WILL MAKE IT TOUGH FOR CONVECTION TO INITIATE. THUS WILL MAINTAIN A DRY FORECAST. ABOVE NORMAL TEMPERATURES EXPECTED LATE WEEK INTO THE WEEKEND WITH HIGHS IN THE MID 80S TO LOWER 90S. WILL HAVE TO KEEP AN EYE ON A POTENTIAL COLD FRONT THAT MAY MOVE IN SUNDAY OR SUNDAY NIGHT. KB FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE CURRENTLY EXPECTED THROUGH THE WEEK. SOUTH/SOUTHWEST WINDS WILL INCREASE TO 15 TO 20 MPH ON WEDNESDAY AND RELATIVE HUMIDITIES MAY FALL TO 15 TO 20 PERCENT ACROSS THE FAR WESTERN PANHANDLES...BUT RECENT RAINFALL AND RESULTANT GREEN-UP SHOULD MITIGATE ANY FIRE WEATHER CONCERNS. WARMER TEMPERATURES WILL CONTINUE LATE WEEK INTO THE WEEKEND AND MINIMUM RELATIVE HUMIDITIES WILL FALL TO 15 TO 20 PERCENT ACROSS WESTERN AREAS. SOUTH/SOUTHWEST WINDS WILL BE BREEZY AT TIMES AND ELEVATED FIRE WEATHER CONDITIONS COULD DEVELOP...BUT AGAIN RECENT RAINFALL AND GREEN-UP WILL HELP MINIMIZE FIRE WEATHER CONCERNS. KB && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 05/15
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
120 AM EDT SAT MAY 12 2012 .SYNOPSIS... HIGH PRESSURE WILL SLIDE EAST ACROSS THE REGION TONIGHT BEFORE PASSING OFFSHORE ON SATURDAY. RETURN SOUTHERLY FLOW AROUND THE HIGH WILL BRING INCREASING MOISTURE BACK TO THE AREA LATE SATURDAY THROUGH SUNDAY. A COLD FRONT WILL DRIFT EAST ACROSS THE REGION SUNDAY NIGHT INTO MONDAY...POSSIBLY RESULTING IN MORE WIDESPREAD SIGNIFICANT RAINFALL INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 1115 PM EDT FRIDAY... HIGH CLOUDS FANNING OUT AHEAD OF THE DEEPER MOISTURE AXIS TO THE WEST SHOULD REMAIN QUITE THIN OVERNIGHT GIVEN DRY AIR IN PLACE PER EVENING RAOBS AND SUBSIDENCE UNDER HIGH PRESSURE. THEREFORE ONLY MADE SOME SMALL UPWARD TWEAKS TO SKY COVER MAINLY OVER THE WEST LATE TONIGHT WHEN THE MORE AGGRESSIVE NAM SHOWS A THICKER CANOPY ARRIVING BY DAYBREAK. OTRW GOING CLEAR TO MOSTLY CLEAR FORECAST ON TRACK WITH THE BETTER MOISTURE ADVECTION NOT ARRIVING UNTIL LATER SATURDAY. SHOULD BE ANOTHER RATHER COOL OVERNIGHT PER LOW DEWPOINTS AND LIGHT WINDS UNDER HIGH PRESSURE PROVIDING GOOD RADIATIONAL COOLING DESPITE SOME HIGH CLOUDS. LOOKS LIKE SPOTTY 30S AGAIN VALLEYS WITH SOME PATCHY FROST POSSIBLE MAINLY FAR NW BUT NOT ENOUGH FOR AN ADVISORY GIVEN BRIEF NATURE AT THIS POINT. OTRW APPEARS SHOULD SEE MOST OTHER LOCATIONS IN THE 40S BY MORNING SO BUMPED DOWN LOWS A LITTLE. PREVIOUS DISCUSSION AS OF 250 PM EDT FRIDAY... UPPER RIDGE/SFC HIGH PRESSURE WILL SETTLE OVERHEAD TONIGHT. EXPECT GOOD RADIATIONAL COOLING CONDITIONS UNDER CLEAR SKIES AND LIGHT WINDS. LOWS WILL RANGE FROM THE UPPER 30S IN THE COLDER VALLEY TO THE MID 40S IN THE SOUTH. MOISTURE SLOWLY INCREASES ON SATURDAY AS SURFACE LOW PRESSURE MOVES INTO THE LOWER MISSISSIPPI VALLEY. WITH POOLING OF MOISTURE AND UPSLOPE FLOW...ALLOWED FOR SOME LIGHT SHOWERS IN THE SOUTHWEST MOUNTAINS SATURDAY AFTERNOON. PLAYED HIGH TEMPERATURES SATURDAY AFTERNOON FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID 70S IN THE SOUTHEAST. && .SHORT TERM /TONIGHT THROUGH MONDAY/... AS OF 230 PM EDT FRIDAY... DETERIORATING WEATHER CONDITIONS EXPECTED DURING THE SHORT TERM PERIOD OF THE FORECAST...AS ENERGY FROM SOUTHERN STREAM LOW ACROSS TEXAS TODAY MERGES WITH A NORTHERN STREAM WAVE MOVING THROUGH THE GREAT LAKES. THE FIRST FORECAST CONCERN IS WHEN PRECIP DEVELOPS. THE GFS MOISTENS THE AIR MASS QUICKLY...INCREASING PWATS TO OVER AN INCH OVER MUCH OF THE FORECAST AREA BY SUNDAY MORNING. THE NAM IS MUCH SLOWER...BUT WAS DISREGARDED. WITH THE LOW LEVEL THETA-E RIDGE SNEAKING UP THE FAR WESTERN PORTION OF THE FORECAST AREA...COMBINED WITH ISENTROPIC LIFT...KEPT SMALL POPS ACROSS THE FAR WESTERN PORTION OF THE FORECAST AREA. ON SUNDAY...WEAK SHORT WAVES BEGIN TO INVADE THE AREA FROM THE SOUTHWEST IN A DEEP SOUTHWEST FLOW. MOST OF THE PRECIPITATION SHOULD REMAIN IN THE WESTERN HALF OF THE FORECAST AREA UNDER THE THETA-E RIDGE. PRECIP SHOULD EXPAND EAST OF THE BLUE RIDGE BY LATE SUNDAY NIGHT AND ESPECIALLY MONDAY AS THE SFC COLD FRONT APPROACHES AND LOW LEVEL WINDS BACK...INCREASING LOW LEVEL CONVERGENCE. PLUS A BROAD AREA OF UPPER DIVERGENCE FORMS AS OUR FORECAST AREA FALLS UNDER THE RR QUAD OF NORTHERN STREAM JET. THIS SPELLS THE POTENTIAL FOR A HEAVY RAIN EVENT ON MONDAY..AS PWATS INCREASE TO GREATER THAN 2 STANDARD DEVIATIONS ABOVE NORMAL ON MONDAY...AND WITH GEFS...AND TO LESSER EXTENT...NAEFS HYDROLOGIC ENSEMBLES SHOWING A SMALL CHANCE SOME RIVER GAUGE LOCATIONS EXCEEDING ACTION STAGE. THEREFORE...WILL INTRODUCE A MENTION OF THE THREAT FOR MINOR FLOODING IN THE HWO. WITH EXTENSIVE CLOUD COVER AND PRECIP EXPANDING IN COVERAGE...NARROWED THE DIURNAL RANGE IN TEMPS...INCREASING LOWS AND REDUCING HIGHS...ESPECIALLY MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 230 PM EDT THURSDAY... AN ACTIVE WEATHER PATTERN IS IN STORE FOR THE EARLY PART OF THE LONG TERM PERIOD. BOTH THE GFS AND ECMWF PHASE THE SOUTHERN STREAM LOW CURRENTLY IN TEXAS...WITH A NORTHERN STREAM WAVE MOVING ACROSS THE GREAT LAKES. THE RESULTS IN A PERSISTENT LONG WAVE TROF ACROSS THE EASTERN U.S...WITH WAVES OF LOW PRESSURE AT THE SFC RIDING NORTHEAST ALONG A SLOW MOVING FRONTAL BOUNDARY THROUGH TUESDAY NIGHT AND POTENTIALLY INTO WEDNESDAY. THE 00Z ECMWF IS MOST PROGRESSIVE WITH MOVING THE AXIS OF THIS UPPER TROF TO THE EAST OF OUR AREA WEDNESDAY...WHILE THE 06Z GFS IS MUCH SLOWER AND DEEPER...WHICH APPEARS TO BE AN OUTLIER WHEN COMPARED TO ITS ENSEMBLES. A SOLUTION SOMEWHERE BETWEEN IS PROBABLY THE MOST LIKELY SCENARIO...AS THE ECMWF ENSEMBLE MEAN SUGGESTS. AS A RESULT...KEPT POPS IN THE FORECAST FOR WEDNESDAY. LATER THE LONG TERM PERIOD...THE LONG RANGE MODELS DIVERGENCE CONSIDERABLY ON THE WHAT WILL TRANSPIRE. THE 12Z GFS DEVELOPS A CUT OFF LOW IN EASTERN NC...WHILE 0Z ECMWF LIFTS THE EASTERN U.S. TROF WELL AWAY FROM OUR AREA. THE MAJORITY OF THE INDIVIDUAL GFS ENSEMBLES AGREE WITH THE ECMWF ENSEMBLE MEAN OF KEEPING AN OPEN UPPER LEVEL TROF OVER THE EASTERN U.S. WITH THE RNK FORECAST AREA JUST TO THE WEST OF THE UPPER TROF AXIS FROM THE ENSEMBLE MEANS...WILL KEEP THE FORECAST DRY...BUT CONFIDENCE IS LOW DURING THIS TIME. && .AVIATION /05Z SATURDAY THROUGH WEDNESDAY/... AS OF 115 AM EDT SATURDAY... HIGH CLOUDS SPREAD INTO THE AREA FROM THE WEST TODAY. LOWER LEVELS OF THE ATMOSPHERE WILL TAKE LONGER TO MOISTEN UP BUT WITH SURFACE HIGH PRESSURE OFFSHORE A LOWER CEILING...BUT STILL VFR...WILL DEVELOP THIS EVENING. HIGH CONFIDENCE THAT CONDITIONS WILL REMAIN VFR THROUGH SUNDAY MORNING. CEILINGS AND VISIBILITIES WILL LOWER TO MVFR LEVELS AT KBLF AND KLWB ON SUNDAY THEN ALSO AT ALL OTHER SITES SUNDAY NIGHT THROUGH TUESDAY AS LOW PRESSURE AND THE ASSOCIATED PRECIPITATION MOVE EAST. IFR CONDITIONS WILL ALSO BE POSSIBLE ESPCLY ACROSS THE WESTERN LOCATIONS SUNDAY NIGHT INTO MONDAY IN ASSOCIATION WITH AN AXIS OF HEAVIER RAINFALL ALONG THE FRONT. DRIER AIR SHOULD FINALLY WORK IN TUESDAY NIGHT INTO WEDNESDAY BRINGING A RETURN TO VFR BY MIDWEEK. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH NEAR TERM...JH/KK SHORT TERM...PH LONG TERM...PH AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1112 PM MDT SUN MAY 13 2012 .AVIATION... WEAK OUTFLOW BOUNDARY HEADING WESTWARD TOWARDS KCOS AND KPUB WILL SHIFT WINDS FROM A LIGHT EASTERLY DIRECTION AT THE START OF THE TAF ISSUANCE. WIND SPEEDS WILL REMAIN LESS THAN 10 KTS. OTHERWISE...WITH CLEARING SKIES ALOFT...MOIST LOW LEVELS AND A WEAK EASTERLY WIND...THERE IS STILL THE POTENTIAL FOR SOME FRAGMENTED STRATUS DEVELOPMENT WITH BASES AROUND 010. WILL KEEP THE SCT010 LAYER IN GOING TAFS AFTER 09Z...WITH POTENTIAL FOR GROUND FOG AS NORTHERLY DRAINAGE WIND PICKS UP AT KCOS WHICH SHOULD HELP PREVENT ANY WIDESPREAD PERSIST STRATUS DEVELOPMENT. PERHAPS A LITTLE BETTER CHANCE FOR STRATUS AT KPUB THROUGH THE MORNING HOURS. MON MORNING...CLEARING SKIES AND LIGHT WINDS WILL KEEP CONDITIONS IN THE VFR CATEGORY FOR ALL 3 TAF SITES WITH WIND SPEEDS UNDER 10 KTS. -KT && .PREV DISCUSSION... /ISSUED 956 PM MDT SUN MAY 13 2012/ UPDATE... UPDATED FORECAST TO DECREASE POPS ACROSS WESTERN AND NORTHERN PORTIONS OF THE FORECAST AREA. SCATTERED TO WIDESPREAD SHOWERS WITH EMBEDDED THUNDERSTORMS WILL CONTINUE ACROSS THE SOUTHEAST PLAINS THROUGH 06Z BEFORE DIMINISHING ACROSS MOST OF THE AREA BY 09Z. HRRR SEEMS TO HAVE A FAIR HANDLE ON THE PROGRESSION OF THE PCPN...AND HAVE FOLLOWED IT FOR POPS IN THE LATEST GRID UPDATE. -KT AVIATION... OUTFLOW BOUNDARIES FROM CONVECTION OUT EAST ARE HEADING WESTWARD TOWARDS KCOS AND KPUB...AND MAY BRING A BRIEF WIND SHIFT FROM AN EASTERLY DIRECTION TO BOTH TERMINALS BETWEEN 04 AND 06Z. THIS MAY HELP WITH SOME LOW STRATUS DEVELOPMENT AND WILL CONTINUE TO BE MONITORED TOWARDS THE 06Z TAF ISSUANCE. -KT PREV DISCUSSION... /ISSUED 242 PM MDT SUN MAY 13 2012/ SHORT TERM... (TONIGHT AND MONDAY) .ONE LAST CHANCE AT GETTING SOME RAIN... UPPER LOW CENTER IS DROPPING SOUTH ACROSS WESTERN COLORADO CENTERED NEAR GRAND JUNCTION AT THE PRESENT TIME. LEFT FRONT QUADRANT ACTIVITY ASSOCIATED WITH 70 KNOT JETSTREAM MAXIMA MOVING BY TO THE SOUTH OF THE 4 CORNERS...IS TRIGGERING WIDESPREAD SHOWERS AND THUNDERSTORMS OVER THE SOUTHERN HALF OF THE FORECAST AREA. NORTHERN HALF OF THE FORECAST AREA IS BEING AFFECTED BY LIFT ASSOCIATED WITH UPPER LEVEL DIFFLUENT FLOW AND COLD POOL NEAR UPPER LOW CENTER. THE 2 FEATURES WILL COMBINE TO GIVE MUCH OF SOUTHERN COLORADO ANOTHER SHOT AT SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING... BEFORE EVERYTHING SHIFTS SOUTH INTO NEW MEXICO AFTER MIDNIGHT. SO FAR TODAY...THERE HAVE BEEN PEA TO HALF INCH SIZE HAIL REPORTS IN AN AND AROUND THE AREA. A BRIEFLY INTENSE PULSE STORM THAT DEVELOPED NEAR FLORISSANT EARLIER...HAD A 48 DBZ CORE UP TO ABOUT 34,000 FEET MSL...MINOR ROTATION...AND A VIL HITTING 30. AT THAT ELEVATION...IN THIS ENVIRONMENT...WITH A GOOD AMOUNT OF COLD AIR ALOFT...SOME QUARTER SIZE HAIL WAS CERTAINLY PLAUSIBLE. SAW THIS HAPPEN FROM A STORM 2 MILES EAST OF SOUTH FORK YESTERDAY. FOR THE REMAINDER OF THE EVENING...EXPECT SHOWERS AND THUNDERSTORMS TO SPREAD OFF OF THE MOUNTAINS ONTO THE PLAINS AND CONTINUE EASTWARD...PROBABLY WITH BETTER SUCCESS THAN LAST NIGHT. ATMOSPHERE IS A BIT LESS STABLE TODAY AND DEWPOINTS ARE NOW WIDESPREAD LOWER TO UPPER 40S ACROSS THE PLAINS. THIS SHOULD HELP THE SUCCESS OF THE EVENING CONVECTION ACROSS THE PLAINS. MOST ACTIVITY SHOULD SHIFT SOUTH INTO NEW MEXICO BY MIDNIGHT...WITH JUST SOME LINGERING ACTIVITY SOUTHERN AREAS PAST MIDNIGHT. COULD SEE SOME PATCHY GROUND FOG IN A LOT OF AREAS TOWARD MORNING AS SKIES START TO CLEAR. ONCE THE FOG GETS OUT OF HERE IN THE MORNING...WE SHOULD BE LOOKING AT A MOSTLY SUNNY DAY WITH VERY PLEASANT SEASONAL SPRING TEMPERATURES. STILL AN ISOLATED STORM CHANCE SOUTHERN MOUNTAIN AREAS...BUT LIKELY THE EXCEPTION...NOT THE RULE. THIS JUST IN...JUST HEARD FROM ONE OF OUR HAM RADIO COOPERATORS. APPARENTLY...THE CELL THAT WAS WARNED ON OVER TELLER COUNTY EARLIER DROPPED PEA SIZE HAIL...TO A 1 INCH DEPTH...IN A SWATH FROM THE LAKE GEORGE AREA EASTWARD THROUGH THE FLORISSANT CANYON...TO WITHIN 5 MILES OR SO WEST OF WOODLAND PARK. ALSO GOT A REPORT FROM ANOTHER SPOTTER 2 MILES NORTH OF WOODLAND PARK OF 1/2 DIAMETER HAIL IN THE PAST HOUR. SPRINGTIME IS FUN TIME IN THE ROCKIES. LW LONG TERM... (MONDAY NIGHT THROUGH NEXT SUNDAY) REST OF THE WEEK INTO NEXT WEEKEND LOOKS RELATIVELY BENIGN WITH GENERALLY ABOVE AVERAGE TEMPERATURES AND NO SIGNIFICANT STORMS ON THE HORIZON. TUESDAY...SHOULD BE WARM AND DRY AS AN UPPER RIDGE MOVES SEWD THROUGH CO. TEMPS SHOULD CLIMB INTO THE 80S OVR THE PLAINS...AND 50S-60S FOR THE MTN AREAS. BY WED...FIRST OF A COUPLE SHORT WAVES MOVES THROUGH FROM THE W. THE TROUGH AXIS LOOKS TO BE MOSTLY EA OF OUR AREA BY 00Z THU...AND BEST MID LEVEL WINDS AND FORCING LOOK TO BE FARTHER N...SO STRONGEST AFTERNOON OR EVE CONVECTION AT THIS POINT LOOKS TO BE MAINLY NE OF OUR CWA. HAVE INTRODUCED LOW POPS HOWEVER FOR THE ERN PLAINS IN THE LATE AFTERNOON AND EVENING HOURS. THERE IS JUST ENOUGH BULK SHEAR AND INSTABILITY THAT A COUPLE STRONG STORMS CANNOT BE RULED OUT. THE RIDGE REBUILDS THU INTO FRI...AND AGAIN IT SHOULD BE MOSTLY DRY BOTH DAYS FOR THE ENTIRE AREA...WITH TEMPS IN THE UPPR 80S TO POSSIBLY NR 90 DEGREES OVR THE PLAINS. NEXT DISTURBANCE MOVES IN LATE FRI INTO SAT...AND A COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL PUSH INTO ERN CO SOMETIME ON SAT. SOME POTENTIAL FOR STRONGER CONVECTION WITH THIS SYSTEM...AS DEEPER MOISTURE WITH HIGHER DEWPOINTS BEGINS TO SURGE WWD OVR THE PLAINS BY LATE IN THE DAY OR INTO SUN. NOT VERY CONFIDENT WITH THE MODEL SOLUTIONS FOR THE LATTER PART OF THE WEEKEND...AS THE GFS AND ECMWF CONTINUE TO BE OUT OF PHASE BEYOND SAT. 44 AVIATION... CATTERED THUNDERSTORMS HAVE DEVELOPED OVER THE HIGHER TERRAIN AND WILL SPREAD ONTO THE PLAINS THROUGH THE REMAINDER OF THE AFTERNOON INTO THE EVENING. WILL CONTINUE AT LEAST VCTS MENTION ALL TAF SITES THROUGH 02Z TIME PERIOD...WITH POTENTIAL FOR AT LEAST BRIEF MVFR CONDITIONS UNDER A FEW OF THE STRONGER STORMS. MAINLY VFR CONDITIONS SPREADING FROM NORTH TO SOUTH 03Z-06Z TIME FRAME AS TSRA MOVE INTO NM...THOUGH DUE TO RECENT PRECIPITATION AND LIGHT WINDS...WILL HAVE TO WATCH FOR PATCHY GROUND FOG DEVELOPMENT AROUND SUNRISE MONDAY... ESPECIALLY AT KALS AND KPUB. LW && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31/13
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1125 PM MDT SUN MAY 13 2012 .UPDATE... ISSUED AT 837 PM MDT SUN MAY 13 2012 JUST ISSUED ANOTHER UPDATE. CURRENT PRECIPITATION FORECAST IS TRENDING AND MADE NO CHANGES. THERE WAS LITTLE WIND/MIXING THROUGH THE DAY WITH DEWPOINTS NEARLY THE SAME TODAY AS YESTERDAY. AREA SOUNDINGS SHOW THAT THE LOW LEVEL MOISTURE HAS ALSO CHANGED LITTLE ALTHOUGH THE AIR MASS HAS WARMED. WITH A SIMILAR AIR MASS YESTERDAY THERE WAS SOME MORNING FOG. ALSO CLUSTER OF THUNDERSTORMS DROPPED A DECENT AMOUNT OF RAINFALL OVER A RATHER LARGE AREA OVER WESTERN KIT CARSON AND CHEYENNE COUNTIES. WINDS WILL BE LIGHT AND THEN WILL SHIFT TO THE WEST TO BRING THIS MOISTURE IN FROM THE WEST. CONSIDERING THE RUC THAT HAS A GOOD HANDLE ON THE WIND FIELD...DRIER AIR WORKS ITS WAY INTO THE NORTHEAST HALF OF THE AREA. RUC AND TO A LESSER DEGREE THE ECMWF INCREASE LOW LEVEL MOISTURE OVER THE SOUTHWEST HALF ALTHOUGH THE RUC WOULD SAY IT WILL BE STRATUS. AS A RESULT...ADDED PATCHY TO AREAS OF FOG FOR LATER TONIGHT INTO TOMORROW MORNING. LATEST MAV WAS DOING WELL WITH THE DEWPOINTS AND AS STATED ABOVE USED THE RUC FOR THE WINDS AND BLENDED THEM WITH REALITY. OVERNIGHT LOWS LOOK FINE AT THIS TIME. UPDATE ISSUED AT 623 PM MDT SUN MAY 13 2012 PERSISTENT AND SLOW MOVING CLUSTER OF STORMS LOCATED OVER/NEAR WESTERN KIT CARSON AT THIS TIME. THIS AREA LOOKS TO BE IN AN AREA OF SURFACE/MOISTURE CONVERGENCE COMBINED WITH WEAK SHORTWAVE TROUGH AND DEEPEST MOISTURE. RAISED POPS MUCH HIGHER OUT WEST...EXPANDED AREA OF THUNDERSTORMS AND PER CONVERGENCE AND QPF FORECASTS...EXTENDED THUNDERSTORMS UNTIL 06Z. ALSO INCREASED CLOUD COVER OVER THE WEST AND SOUTHWEST PORTIONS OF THE AREA WHERE CONVECTION IS OCCURRING. OTHERWISE JUST MADE MINOR ADJUSTMENTS WITH THE REMAINING ELEMENTS. && .SHORT TERM...(THIS AFTERNOON THROUGH MONDAY EVENING) ISSUED AT 1157 AM MDT SUN MAY 13 2012 SCATTERED TO BROKEN SKY COVER THIS AFTERNOON WILL PERSIST WITH THE DAYTIME HEATING PRODUCING A WIDESPREAD CU FIELD. EXPECT THIS TO DISSIPATE RAPIDLY FOLLOWING SUNSET WITH DRYER AIR MOVING IN MONDAY AND MONDAY NIGHT AS THE RIDGE OF HIGHER PRESSURE MOVES OVER THE ROCKIES AND HIGH PLAINS REGION. THERE IS SOME CONVECTIVE ACTIVITY DEVELOPING OVER THE HIGH TERRAIN OF COLORADO THIS AFTERNOON...SO THERE IS THE POSSIBILITY OF A FEW SHOWERS MAKING THEIR WAY OVER THE FAR SOUTHWESTERN PORTION OF THE FORECAST AREA LATE THIS AFTERNOON AND EARLY EVENING. ANY SHOWERS THAT DO MAKE IT THIS FAR EAST SHOULD DISSIPATE RAPIDLY AFTER 03Z. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 236 PM MDT SUN MAY 13 2012 TUESDAY-TUESDAY NIGHT...SHORTWAVE RIDGE WILL REMAIN IN PLACE THROUGH TUESDAY NIGHT...WITH LARGE SCALE SUBSIDENCE SUPPORTING DRY CONDITIONS. MUCH WARMER TEMPERATURES ARE EXPECTED WITH GUIDANCE CONTINUING TO SUPPORT TEMPS IN THE MID TO UPPER 80S OVER MUCH OF THE CWA...WITH TEMPS AROUND 90F IN THE EAST. WEDNESDAY-THURSDAY NIGHT...VERY WARM TEMPERATURES CONTINUE WITH SOUTHERLY FLOW IN PLACE AND H85 TEMPS AROUND 25C. HIGHS ON WEDNESDAY AND THURSDAY WILL BE VERY SIMILAR TO TUESDAY...WITH HIGHS OVER MUCH OF THE CWA IN THE UPPER 80S. H5 RIDGE BEGINS TO BREAK DOWN WEDNESDAY AS A SHORTWAVE TROUGH MOVES TOWARDS THE INTER-MOUNTAIN WEST/HIGH PLAINS. STILL SOME RUN-RUN SPREAD BETWEEN GUIDANCE ON TIMING/POSITION OF THIS FEATURE...WITH 12Z ECMWF SLOWER AND DRIER. GFS AND NAM STILL SUPPORT TIMING/COVERAGE FROM PREVIOUS FORECAST WITH THUNDERSTORMS BEGINNING IN EASTERN COLORADO WEDNESDAY AFTERNOON AND SPREADING EAST ACROSS THE CWA THROUGH THURSDAY. COVERAGE IS STILL A QUESTION EVEN WITH THE GFS/NAM SOLUTIONS...WITH LIMITED MOISTURE ADVECTION AND INSTABILITY WEDNESDAY/WEDNESDAY NIGHT. I KEPT POPS LIMITED TO SLIGHT CHANCE CATEGORY...AND MADE ONLY MINOR ADJUSTMENTS TO LOCATION OF POPS IN CWA. IF GFS/NAM IS CORRECT THEN BEST CHANCE FOR PRECIP WITH THIS FEATURE MAY END UP BEING THURSDAY OVER OUR EASTERN CWA. FRIDAY-SUNDAY...SUBSIDENCE ASSOCIATED WITH SHORTWAVE RIDGE SHOULD KEEP FRIDAY WARM AND DRY. PRECIP CHANCES RETURN BY SATURDAY AS SW FLOW SET UP ACROSS CWA...AND COLD FRONT DROPS SOUTH ACROSS CWA SUNDAY. THERE IS STILL CONSIDERABLE SPREAD IN UPPER LEVEL PATTERN BETWEEN OPERATIONAL GUIDANCE...HOWEVER BOTH GFS AND ECMWF SUPPORT PRECIP CHANCES SATURDAY THROUGH SUNDAY NIGHT. I CONSIDERED RAISING POPS...HOWEVER WITH SPREAD ON UPPER LEVEL AND SURFACE FEATURES...ITS DIFFICULT TO PIN DOWN FAVORED LOCATIONS AT THIS TIME. RATHER THAN STRAY TOO FAR FROM PREVIOUS TRENDS...I KEPT POPS IN SLIGHT CHANCE/CHANCE CATEGORIES DURING THESE PERIODS TO ACCOUNT FOR MODEL SPREAD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1121 PM MDT SUN MAY 13 2012 VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED THROUGH THE PERIOD. SOME FOG IS EXPECTED AROUND KGLD BUT AT THIS TIME DO NOT EXPECT CREATE BELOW VFR CONDITIONS. && .FIRE WEATHER... ISSUED AT 236 PM MDT SUN MAY 13 2012 RED FLAG CONDITIONS WILL BE POSSIBLE WEDNESDAY THROUGH FRIDAY WITH RH VALUES AND WINDS APPROACHING CRITERIA. BEST CHANCE FOR RED FLAG CRITERIA TO BE MET LOOKS TO BE ON WEDNESDAY AFTERNOON WHEN WINDS GUSTING OVER 25 MPH WILL BE COMMON ACROSS THE CWA. THERE ARE STILL QUESTIONS ON HOW LOW RH VALUES WILL BE WEDNESDAY WITH SHORTWAVE TROUGH MOVING IN FROM THE WEST. IF PROFILES REMAIN DRY ADIABATIC THROUGH THE AFTERNOON...CURRENT TD/RH FORECAST COULD BE TOO HIGH. THIS WILL NEED TO BE MONITORED. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...BULLER SHORT TERM...LOCKHART LONG TERM...DR AVIATION...BULLER FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
210 AM EDT MON MAY 14 2012 .SYNOPSIS... AN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL SLOWLY PROGRESS EAST TOWARD THE SOUTHEAST COAST THROUGH MID WEEK...RESULTING IN AN EXTENDED PERIOD OF UNSETTLED WEATHER. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 925 PM SUNDAY... FOR THE REST OF TONIGHT: THE MID LEVEL TROUGH AXIS EXTENDS FROM LAKE HURON THROUGH INDIANA TO THE LOWER OH VALLEY AND MS THIS EVENING... AND NUMEROUS MINOR PERTURBATIONS CONTINUE TO TRACK UP THE EAST SIDE OF THE TROUGH THROUGH WESTERN/CENTRAL NC. THIS WEAK BUT PERSISTENT DPVA AND A SUBTLE DISSIPATING POCKET OF UPPER DIVERGENCE AS WELL AS DEEPENING AND STRENGTHENING ISENTROPIC UPGLIDE THROUGH 295K- 310K ACTING ON COPIOUS MOISTURE (PRECIPITABLE WATER HAS RISEN FROM JUST BELOW NORMAL TO NEARLY 150% OF NORMAL SINCE THIS MORNING) HAS PRODUCED WIDESPREAD LIGHT RAIN AND DRIZZLE OVER CENTRAL NC SINCE LATE AFTERNOON... PARTICULARLY ON THE WESTERN PIEDMONT. THIS LIGHT RAIN/DRIZZLE AREA... COINCIDENT WITH ONE PARTICULAR BETTER-DEFINED MID LEVEL WAVE... WILL CONTINUE TO MOVE TOWARD THE NORTH NORTHEAST OVER THE NEXT SEVERAL HOURS... AND WILL LIKELY BE FOLLOWED BY A BREAK IN STEADY PRECIPITATION FROM SSW TO NORTH NORTHEAST OVERNIGHT... AS NOTED ON THE HRRR MODEL WHICH IS HANDLING THE CURRENT PRECIPITATION WELL. BUT WITH STEADY ADVECTION IN THE LOWEST 3 KM OF WARM AND VERY MOIST AIR... AND CONVERGENT FLOW AT 850 MB THROUGH THE CENTRAL CAROLINAS EVIDENT ON 00Z UPPER AIR ANALYSES... THE CHANCES FOR MORE PRECIPITATION OVERNIGHT ARE QUITE HIGH... ESPECIALLY OVER THE WESTERN PIEDMONT GIVEN MODEL INDICATIONS OF SUBSTANTIAL LOW LEVEL MOISTURE TRANSPORT CONTINUING IN THIS AREA THROUGH DAYBREAK. NOT OVERLY CONCERNED ABOUT MUCH THUNDER TONIGHT CONSIDERING THE LACK OF MID LEVEL HEIGHT FALLS AND WEAKENING UPPER LEVEL WIND FIELD... PLUS THE DEEP LAYER SHEAR IS VERY WEAK AS ARE THE LOW- AND MID-LEVEL LAPSE RATES. BUT CONSIDERING THE INCOMING PUNCH OF MID LEVEL DRY AIR NOTED ON WATER VAPOR IMAGERY AND 00Z SOUNDINGS FROM THE DEEP SOUTH AND WESTERN GULF COAST... POCKETS OF BETTER (YET STILL VERY MODEST) DESTABILIZATION REMAIN POSSIBLE AND THE RISK OF ISOLATED THUNDER WILL BE RETAINED OVERNIGHT. WITH THE LIGHT NATURE OF THE PRECIPITATION SO FAR AND EXPECTED SPOTTY NATURE OF ADDITIONAL SHOWERS AND ISOLATED STORMS OVERNIGHT... HAVE CUT BACK FORECAST PRECIPITATION AMOUNTS THROUGH DAWN TO NO MORE THAN A THIRD OF AN INCH WEST TO JUST A FEW HUNDREDTHS EAST... ALTHOUGH THE THREAT OF HEAVIER RAIN ON MONDAY STILL APPEARS ON TRACK. EXPECT NEARLY STEADY TEMPS IN THE 60-65 RANGE OVER MUCH OF THE AREA FOR THE REST OF THE NIGHT. -GIH && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/... AS OF 235 PM SUNDAY... MONDAY AND MONDAY NIGHT: BROAD UPPER-LEVEL TROUGH IN PLACE FROM THE GREAT LAKES TO THE LOWER MS VALLEY WILL GET REINFORCED BY SHORTWAVE TROUGH DIVING SOUTHEAST ALONG THE SOUTHERN ROCKIES AND INTO THE SOUTHERN PLAINS ON MONDAY. MEANWHILE...WEAK FRONTAL ZONE AND ASSOCIATED WAVE OF LOW PRESSURE OVER THE SOUTHERN APPALACHIANS WILL INCH SLOWLY EASTWARD INTO THE WESTERN CAROLINAS THROUGH MONDAY NIGHT. SHORTWAVE ENERGY IS EXPECTED TO EJECT EAST-NORTHEASTWARD ACROSS THE AREA IN THE SOUTHWEST FLOW ALOFT DOWNSTREAM OF THE BROAD TROUGH AND WITHIN THE ANOMALOUSLY HIGH (2 STD ABOVE NORMAL)PRECIPITABLE WATER AIR MASS LYING ALONG AND EAST OF THE WEAK FRONTAL ZONE ACROSS WESTERN NC. DAYTIME HEATING OF THE MOIST BOUNDARY LAYER WILL SUPPORT NUMEROUS TO WIDESPREAD SHOWERS/THUNDERSTORMS MONDAY AFTERNOON/EVENING...WITH AN AXIS OF MODERATE TO HEAVY RAINFALL NOT BUDGING VERY MUCH...CENTERED ALONG AND ON THE EASTERN SLOPES OF THE APPALACHIANS AND POTENTIALLY EXTENDING EAST INTO THE WESTERN PIEDMONTS OF NC AND VIRGINIA. WHILE THERE REMAINS SOME UNCERTAINTY WITH REGARD TO TO THE TIMING OF THE EMBEDDED SHORTWAVE IMPULSES...MODEL CONSENSUS INDICATES THAT THE HEAVY RAINFALL AXIS AND HIGHEST WILL SHIFT EASTWARD MONDAY NIGHT...REACHING THE COASTAL SECTIONS BY DAYBREAK TUESDAY. SEVERE WEATHER THREAT: WHILE MOIST ADIABATIC PROFILES WILL SUPPORT WEAK MID-LEVEL LAPSE RATES AND INSOLATION SHOULD BE GREATLY IMPEDED BY WIDESPREAD CLOUDS...MODELS STILL SUGGEST THE POTENTIAL FOR WEAK TO MODERATE DESTABILIZATION COULD DEVELOP MONDAY AFTERNOON. UNIDIRECTIONAL SOUTHWEST FLOW OF 25-30 KT COULD SUPPORT A CLUSTER OR TWO OF STRONG TO SEVERE THUNDERSTORMS THAT COULD PRODUCE DAMAGING WET MICROBURSTS. WITH LOSS OF DAYTIME HEATING ...THE THREAT OF SEVERE WEATHER SHOULD BE ON THE WANE MONDAY NIGHT AS THE AIR MASS COOLS/STABILIZES. HEAVY RAIN THREAT: WHILE IT WILL GREATLY DEPEND ON HOW MUCH RAINFALL WE SEE THIS AFTERNOON AND TONIGHT...THE WESTERN PIEDMONT/TRIAD AREA COULD POTENTIALLY ADD ANOTHER 1 TO 2 INCHES MONDAY AND MONDAY NIGHT TO WHATEVER WE SEE TONIGHT. 3 HOUR FLASH FLOOD GUIDANCE TODAY FOR THOSE AREAS ARE AROUND 3.0"...BUT IF WE RECEIVE AN INCH OF RAIN TONIGHT...IT SHOULD LOWER THE GUIDANCE SIGNIFICANTLY...CLOSE TO THE TWO INCH THRESHOLD. LATER SHIFTS MAY NEED TO CONSIDER A FLASH FLOOD WATCH FOR THE WESTERN PIEDMONT MONDAY AFTERNOON/MONDAY NIGHT. EAST OF THE TRIAD...EXPECT AVERAGE RAINFALL AMOUNTS OF 0.50-1.0"... WITH ONLY LOCALIZED/URBAN FLOODING EXPECTED. TEMPERATURES: HIGHS MONDAY WILL DEPEND ON SHOWER/STORM COVERAGE AND WHETHER WE WILL MANAGE TO SEE ANY BREAKS IN THE EAST. AFTERNOON HIGHS RANGING FROM AROUND 70 WEST TO AROUND 80 EAST. LOWS MONDAY NIGHT AGAIN IN THE 60S. -CBL TUESDAY AND TUESDAY NIGHT: ONGOING SHOWERS AND STORMS TUESDAY MORNING SHOULD BE MOVING INTO THE COASTAL PLAIN AS THE AXIS OF DEEPEST MOISTURE FINALLY SHIFTS TOWARD THE COAST. HOWEVER...THE WEAK SURFACE FRONT IS FORECAST LINGER BACK TO THE WEST ALONG THE MOUNTAINS WHILE THE UPPER TROUGH ENERGY CONTINUES TO EVOLVE WEST OF THE MOUNTAINS....EVENTUALLY PUSHING INTO THE AREA TUESDAY EVENING. WITH SLIGHTLY DRIER AIR FORECAST TO OVERSPREAD CENTRAL NC...SOME BREAKS IN CLOUD COVER AND STRONGER DESTABILIZATION ARE EXPECTED. AHEAD OF THE UPPER TROUGH... THE MAY CONTINUE TO BE SUBTLE DISTURBANCES ALOFT MOVING ACROSS THE PERSISTENT WARM AND MOIST AIR MASS...LEADING TO A SCATTERED SHOWERS AND STORMS BY TUESDAY AFTERNOON. THE NAM IS STRONGEST AND SHOWING A STOUT VORTICITY MAX LIFTING ACROSS THE AREA DURING PEAK HEATING. A TIGHTER HEIGHT FIELD ASSOCIATED WITH THIS FEATURE LEADS TO STRONGER DEEP LAYER SHEAR FORECAST BY THE NAM...BUT THE NAM SEEMS TO BE OVERDONE. THE GFS AND ECMWF SHOW MORE A MORE DIFFUSE WAVE AND ONLY 20-25KT OF 0-6KM BULK SHEAR...WHICH IS SUPPORTED BY MOST SREF MEMBERS. THERE IS CONSIDERABLE SPREAD AMONG SREF MEMBERS REGARDING INSTABILITY...BUT MODIFIED GFS SOUNDINGS FOR TEMPS IN THE UPPER 70S TO LOWER 80S AND DEWPOINTS IN THE LOWER 60S SHOW 500-1000 J/KG OF MLCAPE. A FEW ISOLATED SEVERE STORMS MAY BE POSSIBLE...BUT IF THE UPPER WAVE IS STRONGER...AS THE NAM FORECASTS...THEN THE SEVERE POTENTIAL WILL BE GREATER. HIGHS 77-82. AS THE SURFACE FRONT AND MAIN LOW LEVEL CONVERGENCE ZONE PUSHES INTO THE CWA TUESDAY EVENING...ISOLATED SHOWERS AND STORMS MAY CONTINUE INTO THE OVERNIGHT HOURS. THE FRONT WILL CONTINUE TO BE RATHER SLOW MOVING...AND LOWS SHOULD BE FAIRLY PERSISTENT IN THE UPPER 50S TO LOWER 60S. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 205 AM... A BAGGY UPPER TROUGH IS FORECAST TO BE DROPPING OFF THE MOUNTAINS INTO THE FOOTHILLS AT SUNRISE WEDNESDAY. PROGRESS IS SLOW WITH THE TROUGH AXIS NO FURTHER EAST THAN HIGHWAY ONE AT SUNSET. THE GFS CONTINUES TO BE SHARPEST AND MOST PROGRESSIVE WITH UPPER LEVEL RIDGING IN THE MIDWEST...SLOWING THE EASTWARD PROGRESS OF THE EAST COAST TROUGH. THE MAJORITY OF MODELS ARE FLATTER AND FURTHER WEST WITH MIDWEST RIDGING... WITH THE 850 MILLIBAR TROUGH WELL EAST OF CENTRAL NORTH CAROLINA BY SUNSET. WILL FAVOR THE CONSENSUS WITH SLIGHT CHANCES FOR SHOWERS WEDNESDAY MORNING... AND SMALL AFTERNOON CHANCES FOR THUNDERSTORMS IN THE EAST EXITING DURING THE EVENING. WEAK HIGH PRESSURE ADVANCES TOWARD THE MID ATLANTIC STATES WEDNESDAY NIGHT AND THURSDAY. MID LEVEL FLOW OVER THE CAROLINAS IS WEAK AND GENERALLY FROM THE WEST TO NORTHWEST. MEASURABLE RAIN CHANCES APPEAR MINIMAL IN THIS PATTERN AND WILL PLACE CHANCES AT LESS THAN SLIGHT. 1000 TO 850 MILLIBAR THICKNESSES FORECAST TO BE NEAR CLIMATOLOGY. EXPECT ENOUGH SUNSHINE BOTH DAYS FOR AFTERNOON HIGH TEMPERATURES SETTLE NEAR CLIMATOLOGY AS WELL... WITH HIGHS IN THE UPPER 70S TO LOWER 80S. LOW TEMPERATURES WEDNESDAY AND THURSDAY NIGHTS IN THE MID TO UPPER 50S. MID LEVEL HIGH PRESSURE OVER TENNESSEE FRIDAY WILL EXPAND TOWARD NEW ENGLAND DURING THE WEEKEND. A BROAD AREA OF LOW PRESSURE IS EXPECTED TO BE CENTERED FAR ENOUGH OFF THE CAROLINA COAST TO LEAVE CENTRAL NORTH CAROLINA DRY FRIDAY INTO SUNDAY. WITH THE WEATHER PATTERN OVER THE SOUTHEAST SOMEWHAT STATIC AND LOW LEVEL THICKNESSES NEAR CLIMATOLOGY... TEMPERATURES WILL FOLLOW SUIT. AFTERNOON HIGH TEMPERATURES IN THE UPPER 80S TO LOWER 80S AND LOWS IN THE UPPER 50S TO LOWER 60S. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 1205 AM MONDAY... 24-HR TAF PERIOD: DETERIORATING CONDITIONS ARE EXPECTED THIS MORNING...WITH LITTLE (IF ANY) IMPROVEMENT THROUGH THE REMAINDER OF THE TAF PERIOD. AN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL CONTINUE TO SLOWLY APPROACH THE CAROLINAS FROM THE WEST TODAY AND TONIGHT. PERIODS OF SHOWERS ARE EXPECTED THIS MORNING...WITH CEILINGS LOWERING TO IFR/LIFR AT THE INT/GSO TERMINALS AND MVFR/IFR AT THE RDU/FAY/RWI TERMINALS. PERIODS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON...WITH ONLY A MARGINAL IMPROVEMENT IN CEILINGS DURING PEAK HEATING. EXPECT CEILINGS AND VISBYS TO DECREASE INTO THE IFR/LIFR RANGE EVERYWHERE BETWEEN SUNSET THIS EVENING AND SUNRISE TUESDAY MORNING. SE/SSE WINDS AT ~5 KT WILL PERSIST THROUGH SUNRISE...WITH SE/SSE WINDS INCREASING TO ~10 KT BY THIS AFTERNOON. LOOKING AHEAD: LINGERING LOW LEVEL MOISTURE COMBINED WITH ANOTHER UPPER LEVEL TROUGH APPROACHING THE AREA FROM THE NORTHWEST WILL ALLOW ADVERSE AVIATION CONDITIONS TO PERSIST TUESDAY/TUESDAY NIGHT...WITH SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE AT ALL TERMINALS. IMPROVING CONDITIONS ARE EXPECTED WEDNESDAY/WEDNESDAY NIGHT AS THE UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW PROGRESS CLOSER TOWARD THE SOUTHEAST COAST... THOUGH MVFR CONDITIONS APPEAR LIKELY IN MANY LOCATIONS. UNCERTAINTY INCREASES TOWARD THE LATTER PORTION OF THE WEEK. AT THIS TIME... VFR/MVFR CEILINGS (2500-4500 FT AGL) ARE EXPECTED THURSDAY/FRIDAY. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...GIH SHORT TERM...SMITH/CBL AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1213 AM EDT MON MAY 14 2012 .SYNOPSIS... AN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL SLOWLY PROGRESS EAST TOWARD THE SOUTHEAST COAST THROUGH MID WEEK...RESULTING IN AN EXTENDED PERIOD OF UNSETTLED WEATHER. && .NEAR TERM /THROUGH TONIGHT/... AS OF 925 PM SUNDAY... FOR THE REST OF TONIGHT: THE MID LEVEL TROUGH AXIS EXTENDS FROM LAKE HURON THROUGH INDIANA TO THE LOWER OH VALLEY AND MS THIS EVENING... AND NUMEROUS MINOR PERTURBATIONS CONTINUE TO TRACK UP THE EAST SIDE OF THE TROUGH THROUGH WRN/CENTRAL NC. THIS WEAK BUT PERSISTENT DPVA AND A SUBTLE DISSIPATING POCKET OF UPPER DIVERGENCE AS WELL AS DEEPENING AND STRENGTHENING ISENTROPIC UPGLIDE THROUGH 295K-310K ACTING ON COPIOUS MOISTURE (PRECIPITABLE WATER HAS RISEN FROM JUST BELOW NORMAL TO NEARLY 150% OF NORMAL SINCE THIS MORNING) HAS PRODUCED WIDESPREAD LIGHT RAIN AND DRIZZLE OVER CENTRAL NC SINCE LATE AFTERNOON... PARTICULARLY ON THE WESTERN PIEDMONT. THIS LIGHT RAIN/DRIZZLE AREA... COINCIDENT WITH ONE PARTICULAR BETTER-DEFINED MID LEVEL WAVE... WILL CONTINUE TO MOVE TOWARD THE NNE OVER THE NEXT SEVERAL HOURS... AND WILL LIKELY BE FOLLOWED BY A BREAK IN STEADY PRECIP FROM SSW TO NNE OVERNIGHT... AS NOTED ON THE HRRR MODEL WHICH IS HANDLING THE CURRENT PRECIP WELL. BUT WITH STEADY ADVECTION IN THE LOWEST 3 KM OF WARM AND VERY MOIST AIR... AND CONVERGENT FLOW AT 850 MB THROUGH THE CENTRAL CAROLINAS EVIDENT ON 00Z UPPER AIR ANALYSES... THE CHANCES FOR MORE PRECIP OVERNIGHT ARE QUITE HIGH... ESPECIALLY OVER THE WESTERN PIEDMONT GIVEN MODEL INDICATIONS OF SUBSTANTIAL LOW LEVEL MOISTURE TRANSPORT CONTINUING IN THIS AREA THROUGH DAYBREAK. NOT OVERLY CONCERNED ABOUT MUCH THUNDER TONIGHT CONSIDERING THE LACK OF MID LEVEL HEIGHT FALLS AND WEAKENING UPPER LEVEL WIND FIELD... PLUS THE DEEP LAYER SHEAR IS VERY WEAK AS ARE THE LOW- AND MID-LEVEL LAPSE RATES. BUT CONSIDERING THE INCOMING PUNCH OF MID LEVEL DRY AIR NOTED ON WATER VAPOR IMAGERY AND 00Z SOUNDINGS FROM THE DEEP SOUTH AND WESTERN GULF COAST... POCKETS OF BETTER (YET STILL VERY MODEST) DESTABILIZATION REMAIN POSSIBLE AND THE RISK OF ISOLATED THUNDER WILL BE RETAINED OVERNIGHT. WITH THE LIGHT NATURE OF THE PRECIP SO FAR AND EXPECTED SPOTTY NATURE OF ADDITIONAL SHOWERS AND ISOLATED STORMS OVERNIGHT... HAVE CUT BACK FORECAST PRECIP AMOUNTS THROUGH DAWN TO NO MORE THAN A THIRD OF AN INCH WEST TO JUST A FEW HUNDREDTHS EAST... ALTHOUGH THE THREAT OF HEAVIER RAIN ON MONDAY STILL APPEARS ON TRACK. EXPECT NEARLY STEADY TEMPS IN THE 60-65 RANGE OVER MUCH OF THE AREA FOR THE REST OF THE NIGHT. -GIH && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 235 PM SUNDAY... MONDAY AND MONDAY NIGHT: BROAD UPPER-LEVEL TROUGH IN PLACE FROM THE GREAT LAKES TO THE LOWER MS VALLEY WILL GET REINFORCED BY SHORTWAVE TROUGH DIVING SOUTHEAST ALONG THE SOUTHERN ROCKIES AND INTO THE SOUTHERN PLAINS ON MONDAY. MEANWHILE...WEAK FRONTAL ZONE AND ASSOCIATED WAVE OF LOW PRESSURE OVER THE SOUTHERN APPALACHIANS WILL INCH SLOWLY EASTWARD INTO THE WESTERN CAROLINAS THROUGH MONDAY NIGHT. SHORTWAVE ENERGY IS EXPECTED TO EJECT EAST-NORTHEASTWARD ACROSS THE AREA IN THE SWLY FLOW ALOFT DOWNSTREAM OF THE BROAD TROUGH AND WITHIN THE ANOMALOUSLY HIGH (2 STD ABOVE NORMAL)PWAT AIRMASS LYING ALONG AND EAST OF THE WEAK FRONTAL ZONE ACROSS WESTERN NC. DAYTIME HEATING OF THE MOIST BOUNDARY LAYER WILL SUPPORT NUMEROUS TO WIDESPREAD SHOWERS/TSTMS MONDAY AFTERNOON/EVENING...WITH AN AXIS OF MODERATE TO HEAVY RAINFALL NOT BUDGING VERY MUCH...CENTERED ALONG AND ON THE EASTERN SLOPES OF THE APPALACHIANS AND POTENTIALLY EXTENDING EAST INTO THE WESTERN PIEDMONTS OF NC AND VIRGINIA. WHILE THERE REMAINS SOME UNCERTAINTY WRT TO THE TIMING OF THE EMBEDDED SHORTWAVE IMPULSES...MODEL CONSENSUS INDICATES THAT THE HEAVY RAINFALL AXIS AND HIGHEST WILL SHIFT EASTWARD MONDAY NIGHT...REACHING THE COASTAL SECTIONS BY DAYBREAK TUESDAY. SEVERE WEATHER THREAT: WHILE MOIST ADIABATIC PROFILES WILL SUPPORT WEAK MID-LEVEL LAPSE RATES AND INSOLATION SHOULD BE GREATLY IMPEDED BY WIDESPREAD CLOUDS...MODELS STILL SUGGEST THE POTENTIAL FOR WEAK TO MODERATE DESTABILIZATION COULD DEVELOP MONDAY AFTERNOON. UNIDIRECTIONAL SWLY FLOW OF 25-30 KT COULD SUPPORT A CLUSTER OR TWO OF STRONG TO SEVERE THUNDERSTORMS THAT COULD PRODUCE DAMAGING WET MICROBURSTS. WITH LOSS OF DAYTIME HEATING ...THE THREAT OF SEVERE WEATHER SHOULD BE ON THE WANE MONDAY NIGHT AS THE AIRMASS COOLS/STABILIZES. HEAVY RAIN THREAT: WHILE IT WILL GREATLY DEPEND ON HOW MUCH RAINFALL WE SEE THIS AFTERNOON AND TONIGHT...THE WESTERN PIEDMONT/TRIAD AREA COULD POTENTIALLY ADD ANOTHER 1 TO 2 INCHES MONDAY AND MONDAY NIGHT TO WHATEVER WE SEE TONIGHT. 3 HOUR FLASH FLOOD GUIDANCE TODAY FOR THOSE AREAS ARE AROUND 3.0"...BUT IF WE RECEIVE AN INCH OF RAIN TONIGHT...IT SHOULD LOWER THE GUIDANCE SIGNIFICANTLY...CLOSE TO THE TWO INCH THRESHOLD. LATER SHIFTS MAY NEED TO CONSIDER A FLASH FLOOD WATCH FOR THE WESTERN PIEDMONT MONDAY AFTERNOON/MONDAY NIGHT. EAST OF THE TRIAD...EXPECT AVERAGE RAINFALL AMOUNTS OF 0.50-1.0"... WITH ONLY LOCALIZED/URBAN FLOODING EXPECTED. TEMPERATURES: HIGHS MONDAY WILL DEPEND ON SHOWER/STORM COVERAGE AND WHETHER WE WILL MANAGE TO SEE ANY BREAKS IN THE EAST. AFTERNOON HIGHS RANGING FROM AROUND 70 WEST TO AROUND 80 EAST. LOWS MONDAY NIGHT AGAIN IN THE 60S. -CBL TUESDAY AND TUESDAY NIGHT: ONGOING SHOWERS AND STORMS TUESDAY MORNING SHOULD BE MOVING INTO THE COASTAL PLAIN AS THE AXIS OF DEEPEST MOISTURE FINALLY SHIFTS TOWARD THE COAST. HOWEVER...THE WEAK SURFACE FRONT IS FORECAST LINGER BACK TO THE WEST ALONG THE MOUNTAINS WHILE THE UPPER TROUGH ENERGY CONTINUES TO EVOLVE WEST OF THE MOUNTAINS....EVENTUALLY PUSHING INTO THE AREA TUESDAY EVENING. WITH SLIGHTLY DRIER AIR FORECAST TO OVERSPREAD CENTRAL NC...SOME BREAKS IN CLOUD COVER AND STRONGER DESTABILIZATION ARE EXPECTED. AHEAD OF THE UPPER TROUGH... THE MAY CONTINUE TO BE SUBTLE DISTURBANCES ALOFT MOVING ACROSS THE PERSISTENT WARM AND MOIST AIRMASS...LEADING TO A SCATTERED SHOWERS AND STORMS BY TUESDAY AFTERNOON. THE NAM IS STRONGEST AND SHOWING A STOUT VORT MAX LIFTING ACROSS THE AREA DURING PEAK HEATING. A TIGHTER HEIGHT FIELD ASSOCIATED WITH THIS FEATURE LEADS TO STRONGER DEEP LAYER SHEAR FORECAST BY THE NAM...BUT THE NAM SEEMS TO BE OVERDONE. THE GFS AND ECMWF SHOW MORE A MORE DIFFUSE WAVE AND ONLY 20-25KT OF 0-6KM BULK SHEAR...WHICH IS SUPPORTED BY MOST SREF MEMBERS. THERE IS CONSIDERABLE SPREAD AMONG SREF MEMBERS REGARDING INSTABILITY...BUT MODIFIED GFS SOUNDINGS FOR TEMPS IN THE UPPER 70S TO LOWER 80S AND DEWPOINTS IN THE LOWER 60S SHOW 500-1000 J/KG OF MLCAPE. A FEW ISOLATED SEVERE STORMS MAY BE POSSIBLE...BUT IF THE UPPER WAVE IS STRONGER...AS THE NAM FORECASTS...THEN THE SEVERE POTENTIAL WILL BE GREATER. HIGHS 77-82. AS THE SURFACE FRONT AND MAIN LOW LEVEL CONVERGENCE ZONE PUSHES INTO THE CWA TUESDAY EVENING...ISOLATED SHOWERS AND STORMS MAY CONTINUE INTO THE OVERNIGHT HOURS. THE FRONT WILL CONTINUE TO BE RATHER SLOW MOVING...AND LOWS SHOULD BE FAIRLY PERSISTENT IN THE UPPER 50S TO LOWER 60S. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 310 PM SUNDAY... A SLOW MOVING...WEAK COLD FRONT IS FORECAST TO FINALLY MOVE INTO CENTRAL NC BY WEDNESDAY MORNING...AS A POSITIVELY TITLED UPPER TROUGH EXTENDING FROM THE GREAT LAKES INTO THE DEEP SOUTH BEGINS TO DRIFT EAST ACROSS THE APPALACHIANS MOUNTAINS. DEEP MOISTURE WILL BEGIN TO TREND DOWNWARD FROM WEST TO EAST AS THE TROUGH MOVES INTO THE AREA...AND THUS POPS WILL BE INCREASINGLY FOCUSED OVER THE EASTERN CWA WEDNESDAY AND THURSDAY. TEMPS SHOULD GENERALLY RUN RIGHT AROUND NORMAL (HIGHS AROUND 80 AND LOWS IN THE MID TO UPPER 50S) IF NOT A SLIGHTLY BELOW NORMAL WITH WEAK TROUGHING ALONG THE EAST COAST. THEN...AS ENERGY SWINGING ACROSS THE GREAT LAKES LEAVES THE SOUTHERN END OF THE UPPER TROUGH BEHIND...MODELS DIVERGE REGARDING HOW THE TROUGH WILL EVOLVE AS IT DRIFTS EAST TOWARD THE GA/SC COAST. THE 12Z GFS NEVER QUITE CLOSES OFF AN UPPER LOW AND ALLOWS THE TROUGH TO BE SWEPT OFF TO THE NORTHEAST AS NORTHERN STREAM ENERGY SWINGS ACROSS NEW ENGLAND. THE 00Z ECMWF HAD SHOWN A VERY INTERESTING SOLUTION WITH THE UPPER LOW DEVELOPING ALONG THE SOUTHEAST COAST AND A POSSIBLE SUBTROPICAL-LIKE LOW THAT DRIFTED NORTHWEST INTO NC/SC OVER THE WEEKEND. THE 12Z ECMWF RUN SHOWS THE UPPER LOW FURTHER OFFSHORE AND LITTLE IMPACT OVER NC. THERE IS A LOT OF SPREAD AMONG GFS AND ECWMF ENSEMBLE MEMBERS...SO CONFIDENCE IN SENSIBLE WEATHER IMPACTS NEXT WEEKEND IS LOW AT THE MOMENT....BUT WE WILL KEEP THE FORECAST DRY FOR THIS PACKAGE. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 1205 AM MONDAY... 24-HR TAF PERIOD: DETERIORATING CONDITIONS ARE EXPECTED THIS MORNING...WITH LITTLE (IF ANY) IMPROVEMENT THROUGH THE REMAINDER OF THE TAF PERIOD. AN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL CONTINUE TO SLOWLY APPROACH THE CAROLINAS FROM THE WEST TODAY AND TONIGHT. PERIODS OF SHOWERS ARE EXPECTED THIS MORNING...WITH CEILINGS LOWERING TO IFR/LIFR AT THE INT/GSO TERMINALS AND MVFR/IFR AT THE RDU/FAY/RWI TERMINALS. PERIODS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON...WITH ONLY A MARGINAL IMPROVEMENT IN CEILINGS DURING PEAK HEATING. EXPECT CEILINGS AND VISBYS TO DECREASE INTO THE IFR/LIFR RANGE EVERYWHERE BETWEEN SUNSET THIS EVENING AND SUNRISE TUE MORNING. SE/SSE WINDS AT ~5 KT WILL PERSIST THROUGH SUNRISE...WITH SE/SSE WINDS INCREASING TO ~10 KT BY THIS AFTERNOON. LOOKING AHEAD: LINGERING LOW-LEVEL MOISTURE COMBINED WITH ANOTHER UPPER LEVEL TROUGH APPROACHING THE AREA FROM THE NORTHWEST WILL ALLOW ADVERSE AVIATION CONDITIONS TO PERSIST TUE/TUE NIGHT...WITH SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE AT ALL TERMINALS. IMPROVING CONDITIONS ARE EXPECTED WED/WED NIGHT AS THE UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW PROGRESS CLOSER TOWARD THE SOUTHEAST COAST... THOUGH MVFR CONDITIONS APPEAR LIKELY IN MANY LOCATIONS. UNCERTAINTY INCREASES TOWARD THE LATTER PORTION OF THE WEEK. AT THIS TIME... VFR/MVFR CEILINGS (2500-4500 FT AGL) ARE EXPECTED THU/FRI. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...HARTFIELD SHORT TERM...CBL/BLS LONG TERM...BLS AVIATION...VINCENT
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1155 PM CDT SUN MAY 13 2012 .AVIATION... FOR THE 06Z TAFS...ONGOING SHOWERS AND THUNDERSTORMS WERE NORTH AND WEST OF THE TERMINALS AND ARE EXPECTED TO STAY OUTSIDE OF THE VICINITY OF THE TERMINALS OVERNIGHT. HOWEVER ANOTHER ROUND OF SHOWERS CAN IMPACT THE KAMA/KDHT TERMINALS BY 11-12Z WHILE THINK SHOWERS WILL NOT AFFECT THE KGUY TERMINAL. HAVE KEPT CONDITIONS VFR THROUGH THE FORECAST PERIOD ALTHOUGH MODERATE TO HEAVY RAINFALL CAN BRIEFLY REDUCE VISBYS TO MVFR. AS THE UPPER-LEVEL TROUGH MOVES INTO WEST TX ON MONDAY...SKIES SHOULD BEGIN TO DIMINISH WITH ONLY FEW TO SCT MID CLOUDS BY 20-00Z. CLK && .PREV DISCUSSION... /ISSUED 655 PM CDT SUN MAY 13 2012/ AVIATION... FOR THE 00Z TAFS...ONGOING SHOWERS AND THUNDERSTORMS CONTINUE TO IMPACT THE KAMA TERMINAL WHERE MODERATE TO HEAVY RAIN HAS REDUCED VISBYS DOWN TO BELOW 2 MILES BRIEFLY. CURRENT RADAR IMAGERY SHOWS STORMS SLOWLY MOVING EAST...SO EXPECT TSRA TO IMPACT KAMA THROUGH 01Z. HAVE INSERTED A TEMPO GROUP WITH MVFR VISBYS AT 2SM THROUGH THEN AS ADDITIONAL HEAVY RAINFALL CAN ACCOMPANY THESE STORMS. KDHT IS CURRENTLY REPORTING MVFR VISBYS IN LIGHT FOG WHICH SHOULD CONTINUE THIS EVENING. STORMS CONTINUE TO DEVELOP ACROSS THE EASTERN PLAINS 0F CO/NM AS UPPER LIFT PROVIDED BY AN UPPER SHORTWAVE TROUGH IN THE FOUR CORNERS AREA COMBINES WITH MOIST LOW-LEVEL UPSLOPE FLOW. HAVE CARRIED -SHRA TONIGHT AT THE TERMINALS AS THESE SHOWERS WILL CONTINUE TO MOVE TO THE EAST. OUTSIDE OF ANY STRONGER SHOWER THAT MAY PRODUCE MODERATE OR HEAVY RAINFALL THAT CAN REDUCE BRIEFLY REDUCE VISBYS...EXPECT VFR CONDITIONS THROUGH THE TAF FORECAST PERIOD. THE UPPER SHORTWAVE TROUGH IS EXPECTED TO CONTINUE TO DROP SOUTH AND MOVE INTO WEST TX BY MONDAY AFTERNOON. THUS EXPECT -SHRA MONDAY MORNING AND AFTERNOON WITH SKIES THINNING TOWARD THE END OF THE FORECAST PERIOD...PARTICULARLY AT KGUY/KDHT. CLK PREV DISCUSSION... /ISSUED 332 PM CDT SUN MAY 13 2012/ DISCUSSION... PRIMARY FOCUS IS ON PRECIPITATION CHANCES THROUGH MONDAY. AFTERNOON WATER VAPOR IMAGERY SHOWED A MID/UPPER-LEVEL SHORTWAVE TROUGH SINKING SOUTHEAST ACROSS EASTERN UT TOWARDS THE FOUR CORNERS REGION. MID TO UPPER-LEVEL FORCING AHEAD OF THIS SHORTWAVE HAS COMBINED WITH DAYTIME HEATING/DESTABILIZATION AND LOW-LEVEL UPSLOPE FLOW OVER EASTERN CO AND NM TO GENERATE SHOWERS AND THUNDERSTORMS. THE GREATEST CONVECTIVE COVERAGE IS CURRENTLY ACROSS NORTHEAST NM WORKING INTO THE SOUTHWEST TX PANHANDLE...BUT ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED FARTHER EAST ACROSS THE PANHANDLES DUE TO THE COMBINATION OF AFTERNOON DESTABILIZATION AND BROADER SCALE LIFT AHEAD OF THE SHORTWAVE. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO IMPACT THE AREA THIS EVENING AND OVERNIGHT. THE MID/UPPER-LEVEL SHORTWAVE TROUGH WILL CONTINUE TO DIVE SOUTHEAST...REACHING NORTHERN/CENTRAL NM BY EARLY MONDAY MORNING. DIFFLUENT/DIVERGENT FLOW ALOFT AHEAD OF THIS WAVE WILL CONTINUE TO SUPPORT CONVECTION PROPAGATING EAST/SOUTHEAST OUT OF NM AND CO THIS EVENING AND OVERNIGHT. BEST DYNAMICS WILL BE FOCUSED ACROSS THE SOUTHWEST HALF OF THE AREA AND HAVE ALIGNED POPS ACCORDINGLY. ALSO SOME WEAK ISENTROPIC LIFT EVIDENT ON THE 305K THETA SURFACE ACROSS THE SOUTHWEST TX PANHANDLE THIS EVENING TO FURTHER AID CONVECTION. LATEST LAPS AND RUC ANALYSIS DATA SHOW MLCAPES IN THE 500-1000 J/KG RANGE ACROSS THE WESTERN PANHANDLES WITH LESSER VALUES TO THE EAST AND DEEP LAYER SHEAR AROUND 30-35 KTS IN THE SOUTHWEST TX PANHANDLE...DECREASING TO THE NORTHEAST. THUS COULD SEE A FEW STRONG STORMS THROUGH THIS EVENING CAPABLE OF PRODUCING SMALL HAIL AND GUSTY WINDS...BUT NOT REALLY ANTICIPATING ANY SEVERE WEATHER /ALTHOUGH AN ISOLATED MARGINALLY SEVERE STORM ACROSS THE SOUTHWEST CAN/T BE RULED OUT/. COULD ALSO SEE SOME LOCALLY HEAVY RAIN GIVEN PWATS IN THE THREE QUARTERS OF AN INCH TO ONE INCH RANGE AND SOME TRAINING OF STORMS POSSIBLE. BETTER RAIN CHANCES LOOK TO GRADUALLY SHIFT SOUTH/SOUTHWEST OF THE AREA LATE TONIGHT IN ASSOCIATION WITH STRONGER DIVERGENCE ALOFT...AND ALSO AS THE LLJ AND LOW-LEVEL ISENTROPIC LIFT FOCUS TO OUR SOUTHWEST. RAIN CHANCES LINGER INTO MONDAY...BUT WILL GRADUALLY END FROM NORTH TO SOUTH THROUGH THE DAY AS THE SHORTWAVE CONTINUES TO DIVE SOUTHEAST TO SOUTHEAST NM/SOUTHWEST TX BY EARLY MONDAY EVENING. BETTER RAIN CHANCES WILL BE FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA ON MONDAY. WEAKER INSTABILITY AND SHEAR SHOULD PRECLUDE ANY STRONG OR SEVERE STORMS. WILL ALSO SEE THE COOLEST TEMPS IN THE SOUTH ON MONDAY DUE TO LINGERING CLOUDS/PRECIP...WITH HIGHS FORECAST TO RANGE FROM THE UPPER 60S SOUTHWEST TO MID/UPPER 70S NORTH. DRY CONDITIONS ARE THEN FORECAST BEGINNING MONDAY NIGHT AS SHORTWAVE UPPER RIDGING BUILDS EAST ACROSS THE SOUTHERN AND CENTRAL ROCKIES. TEMPS WILL BEGIN TO REBOUND ON TUESDAY DUE TO RISING HEIGHTS...A RETURN OF WEAK SOUTHERLY WINDS...AND INCREASED SUNSHINE...WITH HIGHS CLIMBING BACK INTO THE UPPER 70S TO LOWER 80S. A DAMPENING MID-LEVEL SHORTWAVE WILL WORK ACROSS THE CENTRAL ROCKIES AND PLAINS WEDNESDAY AND WEDNESDAY NIGHT. THIS COULD POTENTIALLY SPAWN A FEW SHOWERS/THUNDERSTORMS ACROSS THE NORTHERN PANHANDLES WEDNESDAY NIGHT. HOWEVER...CHANCES LOOK LOW AT THIS TIME AS BETTER DYNAMICS WILL STAY TO OUR NORTH AND COME ACROSS AT NIGHT...BY WHICH TIME ELEVATED INSTABILITY LOOKS MINIMAL. THUS KEPT A DRY FORECAST FOR NOW. THE LEE TROUGH WILL DEEPEN ON WEDNESDAY...WITH RESULTANT BREEZY SOUTHWEST WINDS FURTHER CONTRIBUTING TO THE WARM UP. A ZONAL FLOW/BROAD FLAT RIDGING LATE THIS WEAK WILL TRANSITION TO SOUTHWESTERLY OVER THE WEEKEND AS AN UPPER TROUGH WORKS ACROSS THE INTERMOUNTAIN WEST AND ROCKIES EVENTUALLY INTO THE NORTHERN PLAINS. THIS FLOW ALOFT WILL PROMOTE SURFACE LEE TROUGHING AND SOME SHARPENING OF THE DRYLINE BY FRIDAY AND SATURDAY. HOWEVER IT CURRENTLY LOOKS LIKE WARM TEMPS ALOFT AND A LACK OF UPPER FORCING /AS THE TROUGH IS DEFLECTED WELL TO OUR NORTHWEST/ WILL MAKE IT TOUGH FOR CONVECTION TO INITIATE. THUS WILL MAINTAIN A DRY FORECAST. ABOVE NORMAL TEMPERATURES EXPECTED LATE WEEK INTO THE WEEKEND WITH HIGHS IN THE MID 80S TO LOWER 90S. WILL HAVE TO KEEP AN EYE ON A POTENTIAL COLD FRONT THAT MAY MOVE IN SUNDAY OR SUNDAY NIGHT. KB FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE CURRENTLY EXPECTED THROUGH THE WEEK. SOUTH/SOUTHWEST WINDS WILL INCREASE TO 15 TO 20 MPH ON WEDNESDAY AND RELATIVE HUMIDITIES MAY FALL TO 15 TO 20 PERCENT ACROSS THE FAR WESTERN PANHANDLES...BUT RECENT RAINFALL AND RESULTANT GREEN-UP SHOULD MITIGATE ANY FIRE WEATHER CONCERNS. WARMER TEMPERATURES WILL CONTINUE LATE WEEK INTO THE WEEKEND AND MINIMUM RELATIVE HUMIDITIES WILL FALL TO 15 TO 20 PERCENT ACROSS WESTERN AREAS. SOUTH/SOUTHWEST WINDS WILL BE BREEZY AT TIMES AND ELEVATED FIRE WEATHER CONDITIONS COULD DEVELOP...BUT AGAIN RECENT RAINFALL AND GREEN-UP WILL HELP MINIMIZE FIRE WEATHER CONCERNS. KB && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 05/15
AREA FORECAST DISCUSSION
NWS ALBANY NY
649 AM EDT MON MAY 14 2012 .SYNOPSIS... A STATIONARY FRONT WILL SERVE AS PATHWAY FOR SEVERAL DISTURBANCES TO MOVE ALONG IT...STARTING TODAY...THROUGH TUESDAY NIGHT. TODAY DISTURBANCES LOOK FAIRLY WEAK BRAINING SCATTERED TO NUMEROUS SHOWERS. HOWEVER...A STRONGER DISTURBANCE TONIGHT WILL LIKELY BRING A SOAKING POTENTIALLY HEAVY RAINFALL...TO MAINLY CENTRAL AND SOUTHERN PORTIONS OF OUR REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 630 AM...BASED ON REGIONAL RADARS AND THE HRRR EXPERIMENTAL MODEL...HAVE DECIDED TO GO BACK TO THE IDEA OF A MORE STEADIER RAIN (ALBEIT LIGHT) THIS MORNING THEN A BREAK IN THE RAIN (SCATTERED SHOWERS)DURING MUCH OF THE AFTERNOON. ACTUALLY...THE 00Z NAM SUPPORTED THIS IDEA. THE 06Z GFS STILL BRINGS HEAVIER RAIN IN THIS AFTERNOON...BUT AGAIN REGIONAL RADAR DOES NOT SUPPORT THIS IDEA. TINKERED WITH THE QPF BUT NOT MUCH TO REFLECT THIS MODIFICATION IN THINKING. EITHER WAY...IT WILL REMAIN DAMP AND PROBABLY WILL SEE SCATTERED SHOWERS OR PATCHY DRIZZLE THIS AFTERNOON ALONG WITH LOTS OF CLOUDS. NO OTHER CHANGES OTHER THEN TO RE-TOOL THE HOURLY GRIDS...WHICH WERE IN PRETTY GOOD SHAPE. RAINFALL AMOUNTS LOOK TO BE A QUARTER TO MAYBE HALF AN INCH...LIGHTER AMOUNTS UNDER QUARTER OF AN INCH TO THE NORTHWEST. THE CLOUDS AND SHOWERS SHOULD KEEP TEMPERATURES DOWN TODAY...GENERALLY HELD TO THE 60S. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... CONFIDENCE IS NOW HIGHER THAT THE AXIS OF HEAVY RAIN TONIGHT THROUGH TUESDAY NIGHT WILL GENERALLY RUN FROM THE CATSKILLS...NORTHEAST ACROSS THE GREATER CAPITAL DISTRICT INTO THE SOUTHERN VERMONT. THE SYNOPTIC SETUP DOES NOT REALLY LOOK LIKE A CLASSICAL HEAVY RAINFALL EVENT...BUT CERTAINLY A MODERATE ONE. THE UPPER AIR TROUGH IS SOMEWHAT WEAK. THERE WILL BE A LOW LEVEL JET...POSSIBLY INCREASING TO 40KTS TRANSPORTING PWAT VALUES APPROACHING AN INCH AND HALF FROM ALBANY SOUTHWARD. THE FLOW LOOKS TO BE SSE TO SOUTHERLY...THROUGHOUT THE COLUMN. A STRONGER DISTURBANCE...STILL DEVELOPING DOWN IN THE TENNESSEE VALLEY...WILL BE THE ONE TO BRING MORE SIGNIFICANT RAINFALL TONIGHT THROUGH TUESDAY NIGHT AS OUR CENTRAL AND EVENTUALLY SOUTHEAST AREAS COME UNDERNEATH MID LEVEL FRONTOGENESIS AND ASSISTANCE FROM DIVERGENCE ALOFT UNDERNEATH THE LEFT ENTRANCE OF AN UPPER LEVEL JET. THE TOTAL QPF AMOUNT IS STILL SOMEWHAT UNCERTAIN AS THERE IS SOME DISPARITY WITH THE CANADIAN AND EUROPEAN MODELS GENERALLY GIVING A TOTAL RAINFALL IN THE 1-2 INCH RANGE...WHILE THE GFS AND NAM WERE MORE IN THE 2-3+ INCH RANGE. FOR NOW...PER HPC...HAVE LEANED WITH THE AMERICAN MODELS. MORE ABOUT THE QPF AND WHAT IT COULD FOR OUR HYDROLOGICAL SERVICE AREAS (HSA) CAN BE FOUND IN OUR HYDROLOGY SECTION. SHOWALTER INDICES REMAINED POSITIVE WITH VERY LITTLE IF ANY SURFACE INSTABILITY THROUGH TONIGHT. ON TUESDAY SHOWALTER VALUES LOOK TO APPROACH ZERO SO WE WILL INCLUDE A SLIGHT CHANCE OF THUNDER. THE UPPER LEVEL TROUGH LOOKS TO BEGIN TO SLOWLY SHIFT EASTWARD TUESDAY TAKING THE SURFACE FRONT WITH IT AS IT GETS A KICK FROM ANOTHER UPSTREAM DISTURBANCE. THE MODERATE TO HEAVY RAIN WILL SHIFT EASTWARD AS WELL...AND FINALLY END. HOWEVER...THE "KICKER"...ANOTHER COLD FRONT...COULD PRODUCE A ROUND OF SHOWERS AND EVEN THUNDERSTORMS OF ITS OWN WEDNESDAY. THIS LOOKS TO BE A MUCH FASTER MOVING SYSTEM SO ANY PRECIPITATION WITH IT SHOULD NOT BE NEARLY AS HEAVY OR PROLONGED. WITH CLOUDS AND RAIN...THERE WILL BE VERY LITTLE RANGE IN DIURNAL TEMPERATURES THROUGH TUESDAY NIGHT. OVERNIGHT LOWS WILL BE IN THE 50S TO AROUND 60 AND DAYTIME HIGHS IN THE 60S. BY WEDNESDAY...WE EXPECT BREAKS OF SUNSHINE MIDDAY AND AFTERNOON ALONG WITH CONTINUE H850 TEMPERATURES NOT FAR FROM +10C. THEREFORE...LOOK FOR A BOUNCE IN TEMPERATURES AS THEY RISE BACK THROUGH THE 70S...POSSIBLY TOUCHING 80 IN SOME OF THE WARMEST SPOTS MAINLY SOUTH OF ALBANY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A LARGE HIGH PRESSURE SYSTEM WILL BEGIN BUILDING EAST FROM THE GREAT LAKES REGION WEDNESDAY NIGHT...AND BE OVER THE REGION THURSDAY NIGHT AND FRIDAY. DURING THE WEEKEND THE HIGH WILL BECOME A STATIONARY ELONGATED RIDGE THAT WILL STRETCH ALONG THE COAST FROM NEW ENGLAND TO THE MID ATLANTIC STATES. THIS SHOULD KEEP FAIR AND DRY WEATHER OVER THE FORECAST AREA FOR THE ENTIRE LONG TERM PERIOD. AT TIMES... VARIOUS RUNS OF THE GFS/ECMWF HAVE INDICATED THE POSSIBILITY OF SCT CONVECTION FRIDAY OR SATURDAY DUE TO SOME WEAK DISTURBANCES MOVING INTO/THROUGH THE HIGH...BUT THEY HAVE NOT BEEN CONSISTENT WITH THIS SO WILL CONTINUE TO IGNORE THE THREAT AND FORECAST DRY CONDITIONS FOR NOW. TEMPS WILL START THE LONG TERM PERIOD ON THE COOL SIDE...ESPECIALLY AT NIGHT...BUT THEN WARM TO ABOVE NORMAL READINGS BY FRIDAY AND THE WEEKEND. LOWS WEDNESDAY NIGHT WILL BE IN THE UPPER 30S AND 40S. HIGHS THURSDAY IN THE 60S TO LOWER 70S. LOWS THURSDAY NIGHT IN THE MID 30S TO MID 40S. HIGHS FRIDAY IN THE MID 60S TO MID 70S. LOWS FRIDAY NIGHT IN THE UPPER 30S AND 40S. HIGHS SATURDAY IN THE UPPER 60S AND 70S. LOWS SATURDAY NIGHT IN THE 40S AND LOWER 50S...AND HIGHS SUNDAY IN THE 70S. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... A FRONTAL BOUNDARY WILL BE NEARLY STATIONARY SOMEWHERE ACROSS SOUTHEAST NEW YORK AS LOW PRESSURE COMES SLOWLY UP THE APPALACHIAN CHAIN TODAY THROUGH TUESDAY. INITIALLY WIDESPREAD LIGHT RAIN WILL BE OVER THE REGION THIS MORNING WITH A BREAK IN THE PCPN FOR PART OF THIS AFTERNOON POSSIBLE AS RADAR IMAGERY AT 630 AM SHOWS A LARGE AREA OF LITTLE OR NO RAIN OVER ERN PA AND NJ. AS A RESULT...MAINLY VFR CONDITIONS EXPECTED AT THE KGFL/KALB/KPOU TAF SITES FOR MOST OF TODAY...WHILE MVFR/IFR VSBY CONDITIONS WILL OCCUR AT KPSF WHERE THE LOWER VSBYS ARE PRIMARILY DUE TO FOG (CIGS WILL BE MAINLY VFR). DURING THE EARLY AND MIDDLE PART OF THE AFTERNOON...AS NOTED ABOVE... RAINFALL MAY END FOR A TIME OR BECOME SCATTERED. CONDITIONS LIKELY TO BE MAINLY VFR AT ALL FOUR TAF SITES. HOWEVER...AS THE HEAVIER RAIN ARRIVES LATER THIS AFTERNOON...CONDITIONS WILL LOWER TO MVFR AT ALL THE TAF SITES INTO THE VENING...THEN ALL SITES WILL HAVE WIDESPREAD IFR CONDITIONS BY MIDNIGHT...WITHTHE WIDESPREAD IFR CONDITIONS CONTINUING THROUGH THE END OF THE TAF PERIOD AT 12Z TUESDAY. SURFACE WINDS WILL BE CALM OR LIGHT NORTHERLY (5 KTS OR LESS) TO START THE TAF PERIOD...THEN SWITCH TO SOUTHERLY LATER THIS MORNING AND PICK UP TO 5 TO 10 KTS DURING THE AFTERNOON. WINDS WILL REMAIN SOUTHERLY TONIGHT...BUT DECREASE TO 5 KTS OR LESS. .OUTLOOK... TUE-TUE NGT...MVFR/IFR RA LIKELY. WED...MAINLY VFR...SCT SHRA. WED NGT-FRI...VFR...NO WX. && .FIRE WEATHER... DAMP CONDITIONS WILL PREVAIL TODAY IN MOST SECTIONS WITH SCATTERED TO NUMEROUS SHOWERS. AREAS ACROSS THE ADIRONDACKS...MOHAWK VALLEY AND LITCHFIELD COUNTY WILL LIKELY SEE RAINFALL AMOUNTS UNDER A QUARTER OF AN INCH TODAY...WHILE OTHER REGIONS WILL HAVE A QUARTER TO UPWARDS OF NEARLY HALF AN INCH. RH VALUES WILL REMAIN ELEVATED TODAY...GENERALLY NO LOWER THAN 60-75 PERCENT. A SOAKING RAIN IS IN THE OFFING LATER TONIGHT THROUGH TUESDAY NIGHT WITH RAINFALL AMOUNTS RANGING FROM AROUND THREE QUARTERS OF INCH ACROSS THE ADIRONDACKS...TO 1-3 INCHES ACROSS THE REMAINDER OF THE REGION. SOME DRYING IS EXPECTED WEDNESDAY...HOWEVER ADDITIONAL SHOWERS ARE POSSIBLE. MUCH DRIER WEATHER LOOKS LIKELY THURSDAY INTO NEXT WEEKEND. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH TODAY. IT STILL LOOKS AS IF TODAY/S RAINFALL WILL GENERALLY RANGE FROM A QUARTER TO HALF AN INCH...WITH LIGHTER AMOUNTS UNDER A QUARTER OF AN INCH ACROSS THE ADIRONDACKS...MOHAWK VALLEY AND LITCHFIELD COUNTY. THIS RAIN WILL PRODUCE MINOR RISES ON STREAMS AND RIVERS AT THE MOST. THEN...IT LOOKS OF AS IF A MORE STEADY AND POTENTIALLY HEAVIER RAIN WILL ENSUE TONIGHT INTO EARLY TUESDAY NIGHT. RAINFALL AMOUNTS STILL LOOK TO BE IN ONE TO THREE INCH RANGE...EXCEPT A LITTLE LESS ACROSS PORTIONS OF OUR ADIRONDACKS. ASSUMING THIS RAINFALL AMOUNT WORKS OUT...THE ADIRONDACKS SHOULD ONLY SEE ONLY ADDITIONAL MINOR RISES ON STREAMS AND RIVERS. OTHER REGIONS WILL SEE MORE SIGNIFICANT WITHIN BANK RISES ON RIVERS AND STREAMS...WITH MANY OF THEM POSSIBLY REACHING ACTION STAGE. AGAIN...ASSUMING WE HAVE A GOOD HANDLE OF THE QPF AMOUNTS...FLOODING IS NOT LIKELY AND THEREFORE NO FLOOD WATCHES WERE ISSUED WITH THIS RAINFALL EVENT AT THIS TIME. IT WOULD BE A GOOD IDEA TO CHECK BACK ON THE HYDROLOGY STATUS DURING THE NEXT COUPLE OF DAYS. NEVERTHELESS...PONDING OF WATER IS A GOOD BET...MAINLY IN AREAS OF POOR DRAINAGE AS RAINFALL RATES COULD REACH UP TO A QUARTER OF AN INCH AN HOUR AT TIMES LATE TONIGHT INTO EARLY TUESDAY NIGHT. SOME ADDITIONAL RAINFALL IS POSSIBLE ON WEDNESDAY WITH ANOTHER FASTER MOVING COLD FRONT...BUT AT THIS POINT RIVER BASIN QPF WITH THIS SYSTEM LOOKS TO BE UNDER A QUARTER OF AN INCH. DRIER WEATHER IS THEN FORECAST LATE IN THE WEEK AND WEEKEND WHICH WOULD ALLOW RIVERS AND STREAMS TO RECEDE BACK TO MORE SEASONAL LEVELS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...HWJIV NEAR TERM...HWJIV SHORT TERM...HWJIV LONG TERM...HWJIV AVIATION...GJM FIRE WEATHER...HWJIV HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS ALBANY NY
635 AM EDT MON MAY 14 2012 .SYNOPSIS... A STATIONARY FRONT WILL SERVE AS PATHWAY FOR SEVERAL DISTURBANCES TO MOVE ALONG IT...STARTING TODAY...THROUGH TUESDAY NIGHT. TODAY DISTURBANCES LOOK FAIRLY WEAK BRAINING SCATTERED TO NUMEROUS SHOWERS. HOWEVER...A STRONGER DISTURBANCE TONIGHT WILL LIKELY BRING A SOAKING POTENTIALLY HEAVY RAINFALL...TO MAINLY CENTRAL AND SOUTHERN PORTIONS OF OUR REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 630 AM...BASED ON REGIONAL RADARS AND THE HRRR EXPERIMENTAL MODEL...HAVE DECIDED TO GO BACK TO THE IDEA OF A MORE STEADIER RAIN (ALBEIT LIGHT) THIS MORNING THEN A BREAK IN THE RAIN (SCATTERED SHOWERS)DURING MUCH OF THE AFTERNOON. ACTUALLY...THE 00Z NAM SUPPORTED THIS IDEA. THE 06Z GFS STILL BRINGS HEAVIER RAIN IN THIS AFTERNOON...BUT AGAIN REGIONAL RADAR DOES NOT SUPPORT THIS IDEA. TINKERED WITH THE QPF BUT NOT MUCH TO REFLECT THIS MODIFICATION IN THINKING. EITHER WAY...IT WILL REMAIN DAMP AND PROBABLY WILL SEE SCATTERED SHOWERS OR PATCHY DRIZZLE THIS AFTERNOON ALONG WITH LOTS OF CLOUDS. NO OTHER CHANGES OTHER THEN TO RE-TOOL THE HOURLY GRIDS...WHICH WERE IN PRETTY GOOD SHAPE. RAINFALL AMOUNTS LOOK TO BE A QUARTER TO MAYBE HALF AN INCH...LIGHTER AMOUNTS UNDER QUARTER OF AN INCH TO THE NORTHWEST. THE CLOUDS AND SHOWERS SHOULD KEEP TEMPERATURES DOWN TODAY...GENERALLY HELD TO THE 60S. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... CONFIDENCE IS NOW HIGHER THAT THE AXIS OF HEAVY RAIN TONIGHT THROUGH TUESDAY NIGHT WILL GENERALLY RUN FROM THE CATSKILLS...NORTHEAST ACROSS THE GREATER CAPITAL DISTRICT INTO THE SOUTHERN VERMONT. THE SYNOPTIC SETUP DOES NOT REALLY LOOK LIKE A CLASSICAL HEAVY RAINFALL EVENT...BUT CERTAINLY A MODERATE ONE. THE UPPER AIR TROUGH IS SOMEWHAT WEAK. THERE WILL BE A LOW LEVEL JET...POSSIBLY INCREASING TO 40KTS TRANSPORTING PWAT VALUES APPROACHING AN INCH AND HALF FROM ALBANY SOUTHWARD. THE FLOW LOOKS TO BE SSE TO SOUTHERLY...THROUGHOUT THE COLUMN. A STRONGER DISTURBANCE...STILL DEVELOPING DOWN IN THE TENNESSEE VALLEY...WILL BE THE ONE TO BRING MORE SIGNIFICANT RAINFALL TONIGHT THROUGH TUESDAY NIGHT AS OUR CENTRAL AND EVENTUALLY SOUTHEAST AREAS COME UNDERNEATH MID LEVEL FRONTOGENESIS AND ASSISTANCE FROM DIVERGENCE ALOFT UNDERNEATH THE LEFT ENTRANCE OF AN UPPER LEVEL JET. THE TOTAL QPF AMOUNT IS STILL SOMEWHAT UNCERTAIN AS THERE IS SOME DISPARITY WITH THE CANADIAN AND EUROPEAN MODELS GENERALLY GIVING A TOTAL RAINFALL IN THE 1-2 INCH RANGE...WHILE THE GFS AND NAM WERE MORE IN THE 2-3+ INCH RANGE. FOR NOW...PER HPC...HAVE LEANED WITH THE AMERICAN MODELS. MORE ABOUT THE QPF AND WHAT IT COULD FOR OUR HYDROLOGICAL SERVICE AREAS (HSA) CAN BE FOUND IN OUR HYDROLOGY SECTION. SHOWALTER INDICES REMAINED POSITIVE WITH VERY LITTLE IF ANY SURFACE INSTABILITY THROUGH TONIGHT. ON TUESDAY SHOWALTER VALUES LOOK TO APPROACH ZERO SO WE WILL INCLUDE A SLIGHT CHANCE OF THUNDER. THE UPPER LEVEL TROUGH LOOKS TO BEGIN TO SLOWLY SHIFT EASTWARD TUESDAY TAKING THE SURFACE FRONT WITH IT AS IT GETS A KICK FROM ANOTHER UPSTREAM DISTURBANCE. THE MODERATE TO HEAVY RAIN WILL SHIFT EASTWARD AS WELL...AND FINALLY END. HOWEVER...THE "KICKER"...ANOTHER COLD FRONT...COULD PRODUCE A ROUND OF SHOWERS AND EVEN THUNDERSTORMS OF ITS OWN WEDNESDAY. THIS LOOKS TO BE A MUCH FASTER MOVING SYSTEM SO ANY PRECIPITATION WITH IT SHOULD NOT BE NEARLY AS HEAVY OR PROLONGED. WITH CLOUDS AND RAIN...THERE WILL BE VERY LITTLE RANGE IN DIURNAL TEMPERATURES THROUGH TUESDAY NIGHT. OVERNIGHT LOWS WILL BE IN THE 50S TO AROUND 60 AND DAYTIME HIGHS IN THE 60S. BY WEDNESDAY...WE EXPECT BREAKS OF SUNSHINE MIDDAY AND AFTERNOON ALONG WITH CONTINUE H850 TEMPERATURES NOT FAR FROM +10C. THEREFORE...LOOK FOR A BOUNCE IN TEMPERATURES AS THEY RISE BACK THROUGH THE 70S...POSSIBLY TOUCHING 80 IN SOME OF THE WARMEST SPOTS MAINLY SOUTH OF ALBANY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A LARGE HIGH PRESSURE SYSTEM WILL BEGIN BUILDING EAST FROM THE GREAT LAKES REGION WEDNESDAY NIGHT...AND BE OVER THE REGION THURSDAY NIGHT AND FRIDAY. DURING THE WEEKEND THE HIGH WILL BECOME A STATIONARY ELONGATED RIDGE THAT WILL STRETCH ALONG THE COAST FROM NEW ENGLAND TO THE MID ATLANTIC STATES. THIS SHOULD KEEP FAIR AND DRY WEATHER OVER THE FORECAST AREA FOR THE ENTIRE LONG TERM PERIOD. AT TIMES... VARIOUS RUNS OF THE GFS/ECMWF HAVE INDICATED THE POSSIBILITY OF SCT CONVECTION FRIDAY OR SATURDAY DUE TO SOME WEAK DISTURBANCES MOVING INTO/THROUGH THE HIGH...BUT THEY HAVE NOT BEEN CONSISTENT WITH THIS SO WILL CONTINUE TO IGNORE THE THREAT AND FORECAST DRY CONDITIONS FOR NOW. TEMPS WILL START THE LONG TERM PERIOD ON THE COOL SIDE...ESPECIALLY AT NIGHT...BUT THEN WARM TO ABOVE NORMAL READINGS BY FRIDAY AND THE WEEKEND. LOWS WEDNESDAY NIGHT WILL BE IN THE UPPER 30S AND 40S. HIGHS THURSDAY IN THE 60S TO LOWER 70S. LOWS THURSDAY NIGHT IN THE MID 30S TO MID 40S. HIGHS FRIDAY IN THE MID 60S TO MID 70S. LOWS FRIDAY NIGHT IN THE UPPER 30S AND 40S. HIGHS SATURDAY IN THE UPPER 60S AND 70S. LOWS SATURDAY NIGHT IN THE 40S AND LOWER 50S...AND HIGHS SUNDAY IN THE 70S. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... A FRONTAL BOUNDARY WILL BECOME STATIONARY SOMEWHERE ACROSS SOUTHEAST NEW YORK AS LOW PRESSURE COMES SLOWLY UP THE APPALACHIAN CHAIN TO INITIALLY BRING WIDESPREAD LIGHT RAIN INTO THE REGION BY AROUND DAYBREAK. THE RAIN WILL REMAIN LIGHT THROUGH MOST OF MONDAY WITH CIG/VSBY CONDITIONS REMAINING VFR AT THE KGFL/KALB/KPOU/KPSF TAF SITES THROUGH JUST BEFORE NOON MONDAY. DURING MONDAY AFTERNOON CONDITIONS WILL DETERIORATE TO MAINLY MVFR CIGS BUT VSBY WILL LIKELY REMAIN 6 MILES OR MORE. BETWEEN 22Z AND 02Z PCPN WILL BECOME HEAVIER AND VSBYS WILL LOWER TO AROUND 3 MILES WHILE CIGS DROP TO 1000 FEET OR LESS. THE MVFR/IFR CONDITIONS WILL THEN PERSIST THROUGH THE END OF THE TAF PERIOD AT 06Z TUESDAY. SURFACE WINDS WILL BE CALM OR LIGHT NORTHERLY (5 KTS OR LESS) TO START THE TAF PERIOD...THEN SWITCH TO SOUTHERLY MONDAY MORNING AND PICK UP TO 5 TO 10 KTS DURING THE AFTERNOON. WINDS WILL REMAIN SOUTHERLY MONDAY NIGHT...BUT DECREASE TO 5 KTS OR LESS. .OUTLOOK... LATE MON NGT-TUE NGT...MVFR/IFR RA LIKELY. WED...MAINLY VFR...SCT SHRA. WED NGT-FRI...VFR...NO WX. && .FIRE WEATHER... DAMP CONDITIONS WILL PREVAIL TODAY IN MOST SECTIONS WITH SCATTERED TO NUMEROUS SHOWERS. AREAS ACROSS THE ADIRONDACKS...MOHAWK VALLEY AND LITCHFIELD COUNTY WILL LIKELY SEE RAINFALL AMOUNTS UNDER A QUARTER OF AN INCH TODAY...WHILE OTHER REGIONS WILL HAVE A QUARTER TO UPWARDS OF NEARLY HALF AN INCH. RH VALUES WILL REMAIN ELEVATED TODAY...GENERALLY NO LOWER THAN 60-75 PERCENT. A SOAKING RAIN IS IN THE OFFING LATER TONIGHT THROUGH TUESDAY NIGHT WITH RAINFALL AMOUNTS RANGING FROM AROUND THREE QUARTERS OF INCH ACROSS THE ADIRONDACKS...TO 1-3 INCHES ACROSS THE REMAINDER OF THE REGION. SOME DRYING IS EXPECTED WEDNESDAY...HOWEVER ADDITIONAL SHOWERS ARE POSSIBLE. MUCH DRIER WEATHER LOOKS LIKELY THURSDAY INTO NEXT WEEKEND. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH TODAY. IT STILL LOOKS AS IF TODAY/S RAINFALL WILL GENERALLY RANGE FROM A QUARTER TO HALF AN INCH...WITH LIGHTER AMOUNTS UNDER A QUARTER OF AN INCH ACROSS THE ADIRONDACKS...MOHAWK VALLEY AND LITCHFIELD COUNTY. THIS RAIN WILL PRODUCE MINOR RISES ON STREAMS AND RIVERS AT THE MOST. THEN...IT LOOKS OF AS IF A MORE STEADY AND POTENTIALLY HEAVIER RAIN WILL ENSUE TONIGHT INTO EARLY TUESDAY NIGHT. RAINFALL AMOUNTS STILL LOOK TO BE IN ONE TO THREE INCH RANGE...EXCEPT A LITTLE LESS ACROSS PORTIONS OF OUR ADIRONDACKS. ASSUMING THIS RAINFALL AMOUNT WORKS OUT...THE ADIRONDACKS SHOULD ONLY SEE ONLY ADDITIONAL MINOR RISES ON STREAMS AND RIVERS. OTHER REGIONS WILL SEE MORE SIGNIFICANT WITHIN BANK RISES ON RIVERS AND STREAMS...WITH MANY OF THEM POSSIBLY REACHING ACTION STAGE. AGAIN...ASSUMING WE HAVE A GOOD HANDLE OF THE QPF AMOUNTS...FLOODING IS NOT LIKELY AND THEREFORE NO FLOOD WATCHES WERE ISSUED WITH THIS RAINFALL EVENT AT THIS TIME. IT WOULD BE A GOOD IDEA TO CHECK BACK ON THE HYDROLOGY STATUS DURING THE NEXT COUPLE OF DAYS. NEVERTHELESS...PONDING OF WATER IS A GOOD BET...MAINLY IN AREAS OF POOR DRAINAGE AS RAINFALL RATES COULD REACH UP TO A QUARTER OF AN INCH AN HOUR AT TIMES LATE TONIGHT INTO EARLY TUESDAY NIGHT. SOME ADDITIONAL RAINFALL IS POSSIBLE ON WEDNESDAY WITH ANOTHER FASTER MOVING COLD FRONT...BUT AT THIS POINT RIVER BASIN QPF WITH THIS SYSTEM LOOKS TO BE UNDER A QUARTER OF AN INCH. DRIER WEATHER IS THEN FORECAST LATE IN THE WEEK AND WEEKEND WHICH WOULD ALLOW RIVERS AND STREAMS TO RECEDE BACK TO MORE SEASONAL LEVELS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...HWJIV NEAR TERM...HWJIV SHORT TERM...HWJIV LONG TERM...HWJIV AVIATION...GJM FIRE WEATHER...HWJIV HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS MIAMI FL
924 AM EDT MON MAY 14 2012 .UPDATE... THE MORNING SURFACE ANALYSIS SHOWED A RIDGE AXIS EXTENDING WEST OVER CENTRAL FLORIDA WITH LIGHT SOUTHEAST LOW-LEVEL FLOW STREAMING ACROSS SOUTH FLORIDA. A COLD FRONT WAS ANALYZED OVER THE GULF EXTENDING SOUTH FROM THE FL PANHANDLE TO THE SOUTHWEST GULF OF MEXICO. RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A POSITIVELY- TILTED UPPER TROUGH EXTENDING SOUTHWEST OVER THE PLAINS AND A RIDGE AXIS EXTENDING NORTH OVER THE WESTERN ATLANTIC. THIS PLACES SOUTH FLORIDA UNDER PRIMARILY MOIST SOUTHWEST MID TO UPPER FLOW. A WEAK SHORTWAVE TROUGH EMBEDDED WITHIN THIS SOUTHWEST FLOW APPROACHING FROM THE WEST COMBINED WITH SUFFICIENT DAYTIME HEATING AND INSTABILITY WILL BE ENOUGH TO INITIATE AFTERNOON CONVECTION ACROSS PORTIONS OF THE LOCAL AREA TODAY. THE LATEST HRRR AND WRF SOLUTIONS ARE IN DECENT AGREEMENT AND GENERALLY INDICATE THE AFTERNOON CONVECTION SETTING UP OVER THE INTERIOR LOCATIONS AND FARTHER NORTH AROUND THE LAKE AND PALM BEACH COUNTY AREA THROUGH THE EVENING HOURS BEFORE TRENDING DOWN TONIGHT. THIS LINES UP WELL WITH THE LATEST FORECAST PACKAGE AND ONLY SLIGHT MODIFICATIONS WERE NEEDED IN THE HAZARDOUS WEATHER OUTLOOK THIS MORNING TO INCLUDE THE POTENTIAL FOR STRONG WIND GUSTS AND SMALL HAIL WITH ANY STORMS THAT BECOME STRONG TODAY. OTHERWISE...THE PREVIOUS FORECAST PACKAGE REMAINS ON TRACK AND NO OTHER UPDATES WERE NECESSARY AT THIS TIME. 85/AG && .PREV DISCUSSION... /ISSUED 724 AM EDT MON MAY 14 2012/ AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST 16Z WITH EXTENSIVE CIRRUS FIELD ACROSS S FL. CONVECTION IS EXPECTED TO DEVELOP AFT 16Z ACROSS THE INTERIOR AND STEERING FLOW WILL TAKE IT TO THE NNE SO MOSTLY AFFECT THE KPBI TERMINAL. HOWEVER, CANNOT RULE OUT THE POSSIBILITY OF DEVELOPMENT FARTHER TO THE SOUTH AS THE AFTERNOON PROGRESSES BUT CONFIDENCE NOT HIGH TO PLACE IN THE TAFS. LIGHT SE SFC WIND WILL CONTINUE THROUGH THE PERIOD ALLOWING FOR W CST SEA BREEZE AFT 18Z. PREV DISCUSSION... /ISSUED 315 AM EDT MON MAY 14 2012/ DISCUSSION...BROAD UPPER TROUGH OVER THE EASTERN 2/3RDS OF THE U.S. DEEPENS AS A SHORT WAVE MOVES INTO THE TROUGH FROM THE SOUTHERN ROCKIES. THE TROUGH MOVES SLOWLY EASTWARD AND BY THURSDAY MORNING WILL BE ALIGNED WITH THE E U.S. COAST AND EXTEND SW ACROSS THE FLA PANHANDLE INTO THE N GULF OF MEX. AS THE TROUGH MOVES E AND OFFSHORE INTO THE ATLC...A CLOSED LOW WILL DEVELOP OFF OF THE SE U.S. COAST LATE THURSDAY NIGHT AND PERSIST INTO NEXT WEEKEND. AT THE SURFACE...A SURFACE LOW IN THE SOUTHERN APPALACHIANS ALONG THE SURFACE TROUGH ASSOCIATED WITH THE UPPER TROUGH WILL GET TO THE E U.S. COAST AND THE FLA PANHANDLE BY WEDNESDAY NIGHT AS THE SURFACE LOW MOVES INTO THE MID ATLC STATES. THE TROUGH WILL MOVE SE AND THROUGH S FLA THURSDAY AND WILL BE SE OF THE AREA FRIDAY AND SATURDAY. FINALLY THE ECWMF AND GFS INTO SIMILAR AGREEMENT. FOR THE SHORT TERM...TODAY THROUGH WEDNESDAY...AS THE UPPER TROUGH DEEPENS...WINDS ALOFT BECOME SW PULLING SOME DEEPER MOISTURE OVER S FLA. AT THE LOWER LEVELS WINDS WILL BE SE BUT LIGHT ALLOWING E/W COAST SEA BREEZES. COMBINED WITH HEATING...AN INCREASE IN SHOWERS /MAINLY AFTERNOON THUNDERSTORMS CAN BE EXPECTED. WITH THE STEERING WINDS ALOFT SW...THE CONVECTIVE ACTIVITY WILL AFFECT THE INTERIOR AND NE COASTAL AREAS THOUGH ALL ZONES WILL SEE SOME RAINFALL. THIS PATTERN WILL PERSIST EACH DAY WITH NOCTURNAL ACTIVITY POSSIBLE... MAINLY OFF OF THE E COAST IN THE EVENING AND THE W COAST OVER -NIGHT. EXTENDED FORECAST...THURSDAY THROUGH SUNDAY...LITTLE CHANGE THURSDAY THOUGH STEERING WINDS BECOME A LITTLE MORE NW AFFECTING THE E COAST UNIFORMLY WITH CONVECTION. WITH AN UPPER CLOSED LOW DEVELOPING OFF OF THE SE U.S. COAST FRIDAY AND INTO SATURDAY...AND WITH THE SURFACE TROUGH SE OF THE AREA...DRIER AIR WILL MOVE OVER S FLA WITH POPS DROPPING DRASTICALLY. VERY LITTLE...IF AT ALL... LOWERING OF MAX/MIN TEMPERATURES EXPECTED. MARINE... WINDS 10 KNOTS OR LESS TONIGHT THROUGH FRIDAY THOUGH SHIFTING FROM SOUTHERLY TO NORTHERLY THURSDAY AS THE TROUGH MOVES THROUGH. SEAS 2 FEET OR LESS AS WELL. FIRE WEATHER... RELATIVE HUMIDITY VALUES REMAIN ABOVE 35 PERCENT CRITICAL VALUE THROUGH MID WEEK. NO PROBLEMS EXPECTED. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 84 73 85 72 / 50 40 50 40 FORT LAUDERDALE 84 74 85 75 / 40 30 50 40 MIAMI 85 74 86 74 / 30 30 50 30 NAPLES 86 70 86 71 / 30 20 30 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...57/DG
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
946 AM CDT MON MAY 14 2012 .DISCUSSION...THE REMAINS OF AN MCS IS WEAKENING AS IT MOVES SOUTHEAST ACROSS THE WESTERN CWA. MOST MODELS DID NOT EVEN PICK UP ON THIS PRECIP...HOWEVER THE LATEST RUC13 HAS AND IT SHOWS THE PRECIP DISSIPATING OVER THE NEXT COUPLE OF HOURS...MAINLY DUE TO A SLIGHTLY SUBSIDENT/DRIER AIRMASS IN PLACE ACROSS THE E CWA. ONLY CONCERN IS THAT THIS PRECIP IS HEADING TOWARD AN AREA OF LESS CIN/HIGHER CAPE ACROSS THE E CWA. FOR NOW...WILL LEAVE POPS AS IS FOR TODAY UNLESS THIS SYSTEM RE-INTENSIFIES. REST OF FCST LOOKS ON TRACK. NO MAJOR CHANGES TO THE FCST AT THIS TIME. && .PREV DISCUSSION... /ISSUED 724 AM CDT MON MAY 14 2012/ DISCUSSION...INTRODUCED SLIGHT END POPS UNTIL 18Z ACROSS THE RIO GRANDE PLAINS AS MCS CONTINUES TO MOVE SOUTHEAST THIS MORNING. UPDATED PRODUCTS OUT. PREV DISCUSSION... /ISSUED 659 AM CDT MON MAY 14 2012/ DISCUSSION...UPDATED FOR 12Z AVIATION AVIATION...LINGERING CONVECTION OVER MAVERICK COUNTY SHOULD CONTINUE TO MOVE EAST...BUT SHOULD NOT IMPACTING THE TERMINALS. OTHERWISE...VFR CONDITIONS TO PERSIST THROUGH TODAY. UPPER LEVEL DISTURBANCE AND CHANCES FOR CONVECTION WILL INCREASE TONIGHT FROM THE NORTHWEST. INCLUDED VCTS REMARKS AT LRD IN ANTICIPATION OF MCS DEVELOPING TONIGHT. DID NOT INCLUDE AT THE OTHER TERMINALS ATTM. WINDS GENERALLY REMAIN LESS THAN 12 KNOTS AT ALI/CRP/VCT...BUT MAY BECOME A LITTLE GUSTY IN THE AFTERNOON AT LRD. PREV DISCUSSION... /ISSUED 409 AM CDT MON MAY 14 2012/ SHORT TERM (TODAY THROUGH TUESDAY)...LATEST RADAR TRENDS SHOW WEAKENING MCS OVER THE BIG BEND OF TEXAS. ANTICIPATE THIS CONVECTION WILL NOT MAKE IT INTO LA SALLE AND WEBB COUNTIES SO WILL KEEP POPS SILENT FOR THE MORNING HOURS. UPPER LEVEL TROUGH WILL DROP SOUTHEAST OUT OF NEW MEXICO TODAY AND TONIGHT. MOISTURE FIELDS BEGIN TO INCREASE BY THIS EVENING. HIGH RESOLUTION MODELS DEVELOP ANOTHER MCS OVER THE BIG BEND TONIGHT WITH IT TRACKING FURTHER TO THE SOUTHEAST...APPROACHING THE NORTHWESTERN ZONES BETWEEN 03Z AND 06Z TUESDAY. IF STORMS ARE ABLE TO MAINTAIN THEIR STRENGTH...THEN PERHAPS A DAMAGING WIND GUST THREAT COULD EMERGE...BUT CONFIDENCE OF THIS OCCURRING IS ON THE LOW SIDE. WENT AHEAD AND INCREASED POPS ACROSS LA SALLE AND WEBB COUNTIES TO 60 PERCENT...TAPERING OFF TO 20 PERCENT OVER THE COASTAL WATERS FOR THE TONIGHT PERIOD. HIGHER RAINFALL AMOUNTS SHOULD OCCUR NORTH OF THE AREA. UPPER TROUGH WEAKEN A BIT AS IT CONTINUES TO MOVE TO THE SOUTHEAST ON TUESDAY. NAM/GFS IN DECENT AGREEMENT ON PRECIP CHANCES AND HAVE RAISED THEM A LITTLE. CLOUD COVER AND CHANCES FOR PRECIP WILL KEEPS TEMPS DOWN ON TUESDAY... MAINLY IN THE LOWER 80S. FAVORED THE COOLER METMOS TEMPS. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ANY PRECIP THAT EXISTS AT START OF LONG TERM PERIOD SHOULD END FROM NORTH TO SOUTH AS UPPER LEVEL TROUGH AXIS SWINGS SOUTH OF CWA AND SURFACE HIGH PRESSURE BUILDS INTO AREA. 00Z ECMWF IS ABOUT SIX HRS SLOWER THAN GFS WITH MOVEMENT OF SYSTEM AND A LINGERING CHANCE OF PRECIP MAY BE NEEDED IN LATER FORECAST PKGS IF SYSTEM SLOWS...BUT FOR NOW WILL LEAVE WED DRY. QUIET WX THEN EXPECTED FOR SECOND HALF OF WORK WEEK AS WEAK MID/UPPER LEVEL RIDGING DEVELOPS RESULTING IN WNW FLOW ALOFT AND LIMITED DEEP LAYER MOISTURE. BY NEXT WEEKEND GFS AND ECMWF DIFFER SOMEWHAT WITH MID/UPPER LEVEL PATTERN. GFS HAS MORE ZONAL FLOW WITH ELONGATED MID LEVEL RIDGING WHILE ECMWF HAS MORE PRONOUNCED S/W TROUGHS MOVING ACROSS THE PLAINS. BOTH GUIDANCE SUITES INITIATE SURFACE CYCLOGENESIS ACROSS THE NORTHERN SOUTH HIGH PLAINS AND DIURNAL SFC TROUGHING WHICH IN TURN SHOULD TIGHTEN THE PRESSURE GRADIENT ACROSS S TX AND ALLOW LOW LEVEL MOISTURE ADVECTION TO INCREASE. LOW LEVEL MOISTURE VALUES AND WIND PROFILE MAY BECOME MORE CONDUCIVE FOR ISOLATED STREAMER SHOWERS ACROSS MARINE ZONES AND COASTAL PLAINS BY LATE IN THE EXTENDED PERIOD. TEMPS ARE EXPECTED TO BE AT OR SLIGHTLY ABOVE SEASONABLE VALUES /EXCEPT AROUND MID WEEK WHERE BELOW NORMAL MIN TEMPS MAY OCCUR WHEN HIGH PRESSURE CENTER IS THE CLOSEST/ AND HAVE GENERALLY GONE CLOSE TO A BIAS CORRECTED MOSGUIDE/ECMWF BLEND. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 86 68 82 64 86 / 10 30 50 20 10 VICTORIA 86 64 80 60 86 / 10 30 50 20 10 LAREDO 92 69 86 67 91 / 20 50 50 20 10 ALICE 89 66 84 61 88 / 10 30 50 20 10 ROCKPORT 86 71 80 68 86 / 10 30 50 20 10 COTULLA 88 64 82 60 89 / 20 60 50 10 10 KINGSVILLE 88 68 84 62 87 / 10 30 50 30 10 NAVY CORPUS 84 71 82 68 84 / 10 30 50 30 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ TE/81...SHORT TERM GW/86...LONG TERM
AREA FORECAST DISCUSSION
NWS MIAMI FL
156 PM EDT MON MAY 14 2012 .AVIATION...VFR WILL PREVAIL. SHRA/TSRA WILL CONCENTRATE OVER THE INTERIOR, BUT COULD MOVE TOWARDS KPBI LATER THIS AFTERNOON. TRANQUIL WEATHER IS EXPECTED OVERNIGHT. TSRA IS A BETTER BET FOR THE EAST COAST TERMINALS ON TUE AFTERNOON. ADDED VCTS THERE FOR NOW, BUT TEMPO WILL LIKELY BE NEEDED AT LATER FORECAST ISSUANCES. /GREGORIA && .PREV DISCUSSION... /ISSUED 924 AM EDT MON MAY 14 2012/ UPDATE... THE MORNING SURFACE ANALYSIS SHOWED A RIDGE AXIS EXTENDING WEST OVER CENTRAL FLORIDA WITH LIGHT SOUTHEAST LOW-LEVEL FLOW STREAMING ACROSS SOUTH FLORIDA. A COLD FRONT WAS ANALYZED OVER THE GULF EXTENDING SOUTH FROM THE FL PANHANDLE TO THE SOUTHWEST GULF OF MEXICO. RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A POSITIVELY- TILTED UPPER TROUGH EXTENDING SOUTHWEST OVER THE PLAINS AND A RIDGE AXIS EXTENDING NORTH OVER THE WESTERN ATLANTIC. THIS PLACES SOUTH FLORIDA UNDER PRIMARILY MOIST SOUTHWEST MID TO UPPER FLOW. A WEAK SHORTWAVE TROUGH EMBEDDED WITHIN THIS SOUTHWEST FLOW APPROACHING FROM THE WEST COMBINED WITH SUFFICIENT DAYTIME HEATING AND INSTABILITY WILL BE ENOUGH TO INITIATE AFTERNOON CONVECTION ACROSS PORTIONS OF THE LOCAL AREA TODAY. THE LATEST HRRR AND WRF SOLUTIONS ARE IN DECENT AGREEMENT AND GENERALLY INDICATE THE AFTERNOON CONVECTION SETTING UP OVER THE INTERIOR LOCATIONS AND FARTHER NORTH AROUND THE LAKE AND PALM BEACH COUNTY AREA THROUGH THE EVENING HOURS BEFORE TRENDING DOWN TONIGHT. THIS LINES UP WELL WITH THE LATEST FORECAST PACKAGE AND ONLY SLIGHT MODIFICATIONS WERE NEEDED IN THE HAZARDOUS WEATHER OUTLOOK THIS MORNING TO INCLUDE THE POTENTIAL FOR STRONG WIND GUSTS AND SMALL HAIL WITH ANY STORMS THAT BECOME STRONG TODAY. OTHERWISE...THE PREVIOUS FORECAST PACKAGE REMAINS ON TRACK AND NO OTHER UPDATES WERE NECESSARY AT THIS TIME. 85/AG PREV DISCUSSION... /ISSUED 724 AM EDT MON MAY 14 2012/ AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST 16Z WITH EXTENSIVE CIRRUS FIELD ACROSS S FL. CONVECTION IS EXPECTED TO DEVELOP AFT 16Z ACROSS THE INTERIOR AND STEERING FLOW WILL TAKE IT TO THE NNE SO MOSTLY AFFECT THE KPBI TERMINAL. HOWEVER, CANNOT RULE OUT THE POSSIBILITY OF DEVELOPMENT FARTHER TO THE SOUTH AS THE AFTERNOON PROGRESSES BUT CONFIDENCE NOT HIGH TO PLACE IN THE TAFS. LIGHT SE SFC WIND WILL CONTINUE THROUGH THE PERIOD ALLOWING FOR W CST SEA BREEZE AFT 18Z. PREV DISCUSSION... /ISSUED 315 AM EDT MON MAY 14 2012/ DISCUSSION...BROAD UPPER TROUGH OVER THE EASTERN 2/3RDS OF THE U.S. DEEPENS AS A SHORT WAVE MOVES INTO THE TROUGH FROM THE SOUTHERN ROCKIES. THE TROUGH MOVES SLOWLY EASTWARD AND BY THURSDAY MORNING WILL BE ALIGNED WITH THE E U.S. COAST AND EXTEND SW ACROSS THE FLA PANHANDLE INTO THE N GULF OF MEX. AS THE TROUGH MOVES E AND OFFSHORE INTO THE ATLC...A CLOSED LOW WILL DEVELOP OFF OF THE SE U.S. COAST LATE THURSDAY NIGHT AND PERSIST INTO NEXT WEEKEND. AT THE SURFACE...A SURFACE LOW IN THE SOUTHERN APPALACHIANS ALONG THE SURFACE TROUGH ASSOCIATED WITH THE UPPER TROUGH WILL GET TO THE E U.S. COAST AND THE FLA PANHANDLE BY WEDNESDAY NIGHT AS THE SURFACE LOW MOVES INTO THE MID ATLC STATES. THE TROUGH WILL MOVE SE AND THROUGH S FLA THURSDAY AND WILL BE SE OF THE AREA FRIDAY AND SATURDAY. FINALLY THE ECWMF AND GFS INTO SIMILAR AGREEMENT. FOR THE SHORT TERM...TODAY THROUGH WEDNESDAY...AS THE UPPER TROUGH DEEPENS...WINDS ALOFT BECOME SW PULLING SOME DEEPER MOISTURE OVER S FLA. AT THE LOWER LEVELS WINDS WILL BE SE BUT LIGHT ALLOWING E/W COAST SEA BREEZES. COMBINED WITH HEATING...AN INCREASE IN SHOWERS /MAINLY AFTERNOON THUNDERSTORMS CAN BE EXPECTED. WITH THE STEERING WINDS ALOFT SW...THE CONVECTIVE ACTIVITY WILL AFFECT THE INTERIOR AND NE COASTAL AREAS THOUGH ALL ZONES WILL SEE SOME RAINFALL. THIS PATTERN WILL PERSIST EACH DAY WITH NOCTURNAL ACTIVITY POSSIBLE... MAINLY OFF OF THE E COAST IN THE EVENING AND THE W COAST OVER -NIGHT. EXTENDED FORECAST...THURSDAY THROUGH SUNDAY...LITTLE CHANGE THURSDAY THOUGH STEERING WINDS BECOME A LITTLE MORE NW AFFECTING THE E COAST UNIFORMLY WITH CONVECTION. WITH AN UPPER CLOSED LOW DEVELOPING OFF OF THE SE U.S. COAST FRIDAY AND INTO SATURDAY...AND WITH THE SURFACE TROUGH SE OF THE AREA...DRIER AIR WILL MOVE OVER S FLA WITH POPS DROPPING DRASTICALLY. VERY LITTLE...IF AT ALL... LOWERING OF MAX/MIN TEMPERATURES EXPECTED. MARINE... WINDS 10 KNOTS OR LESS TONIGHT THROUGH FRIDAY THOUGH SHIFTING FROM SOUTHERLY TO NORTHERLY THURSDAY AS THE TROUGH MOVES THROUGH. SEAS 2 FEET OR LESS AS WELL. FIRE WEATHER... RELATIVE HUMIDITY VALUES REMAIN ABOVE 35 PERCENT CRITICAL VALUE THROUGH MID WEEK. NO PROBLEMS EXPECTED. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 84 74 84 72 / 50 40 60 40 FORT LAUDERDALE 84 75 85 74 / 40 30 60 40 MIAMI 85 73 86 72 / 30 30 60 30 NAPLES 86 72 85 72 / 30 20 30 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
454 PM EDT MON MAY 14 2012 .SYNOPSIS... LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY MOVE EAST ACROSS THE REGION THROUGH TONIGHT. HIGH MOISTURE WILL CONTINUE AHEAD OF THIS SYSTEM. SOME DRYING IS EXPECTED TUESDAY WHICH WILL RESULT IN SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS THROUGH MIDWEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... UPPER TROUGH STILL TO THE WEST PULLING MOISTURE ACROSS THE REGION FROM THE SOUTH. BOTH OBSERVED AND FORECAST SOUNDINGS ARE NEARLY MOIST ADIABATIC WHICH SHOULD ALLOW SHOWERS TO POP UP WITH THE SLIGHTEST TRIGGER. RUC13 SHOWS WEAK TROUGH ACROSS THE REGION LATE THIS AFTERNOON INTO THE EARLY EVENING HOURS. ALSO...STRONG AFTERNOON SURFACE HEATING HAS ALLOW STRONG AND IN SOME CASES NEAR SEVERE THUNDERSTORM ACTIVITY TO DEVELOP MAINLY IN THE SOUTHERN PART OF THE FORECAST AREA. EXPECT RAINFALL AMOUNTS TO REMAIN ONE QUARTER INCH OR LESS IN THE WESTERN MIDLANDS AND TAPER TO LESS THAN A TENTH OF AN INCH OVER THE EASTERN MIDLANDS THROUGH THIS AFTERNOON...MAINLY DUE TO A LACK OF FORCING. TONIGHT...THE UPPER TROUGH WILL BE SLOW MOVING AS IT MOVES INTO THE REGION AND WILL CONTINUE TO PROVIDE UPPER SUPPORT OVERNIGHT...ESPECIALLY DURING THE EVENING HOURS...THEREFORE WILL CONTINUE WITH LIKELY POPS OVERNIGHT. THE PRECIPITABLE WATER AXIS SHIFTS OVER THE FORECAST AREA OVERNIGHT AND EXPECT THE BEST RAINFALL ACCUMULATION TO OCCUR DURING THIS PERIOD. THE WESTERN AND NORTHERN MIDLANDS WILL LIKELY SEE THE HIGHEST AMOUNTS...POSSIBLY UP TO AN INCH...BUT THE ENTIRE FORECAST AREA SHOULD SEE MODERATE MEASURABLE RAINFALL THROUGH EARLY MONDAY MORNING. TEMPERATURES TONIGHT WILL BE LIMITED BY INCREASED DEWPOINTS AND CLOUDS AND PRECIPITATION...GENERALLY IN THE MID 60S. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/... SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH THE PERIOD AND SHOULD PROVIDE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS. AIR MASS APPEARS TO REMAIN MODERATELY MOIST AND INCREASINGLY UNSTABLE THROUGH THE PERIOD. SOME DRYING SUGGESTED BY MODELS ESPECIALLY GFS...HOWEVER EXPECT PRECIPITABLE WATER TO REMAIN RELATIVELY HIGH...NEAR 1.5 INCHES AT TIMES WITH PERSISTENT SOUTHWEST MOIST 850MB FLOW AHEAD OF UPPER LEVEL TROUGH ACROSS THE MISSISSIPPI VALLEY AND MIDWEST. SEVERAL SHORT WAVE TRIGGERS LIKELY TO ROTATE THROUGH THE REGION...WHICH SHOULD AID THUNDERSTORM DEVELOPMENT...HOWEVER TIMING OF WAVES DIFFICULT. FORECAST HIGH CHANCE POPS DURING THE LATE AFTERNOON AND EVENING TUESDAY...POSSIBLY LATE INTO TUESDAY NIGHT ASSOCIATED WITH POSSIBLE STRONGER SHORT WAVE. CHANCE WEDNESDAY ESPECIALLY EAST MIDLANDS WHERE DEEPER MOISTURE IS AND STRONGER UPPER LEVEL FORCING IS LOCATED. TEMPERATURES SHOULD BE WARMER TUESDAY AND WEDNESDAY WITH SOME BREAKS IN THE OVERCAST MID MORNING THROUGH EARLY AFTERNOON. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED. && .AVIATION /21Z MONDAY THROUGH SATURDAY/... UPPER TROUGH STILL TO THE WEST OF THE FORECAST AREA BRINGING PLENTY OF MOISTURE ON LOW LEVEL SOUTH TO SOUTHWEST WIND FLOW. WITH REAL GOOD SURFACE HEATING WHERE CLOUDS HAVE BROKEN UP... THERE IS A POTENTIAL FOR THUNDERSTORMS TO DEVELOP BUT WILL NOT MENTION IN TAF SITES UNLESS ACTIVITY IS MOVING RIGHT AT TAF SITE. RUC13 H5 SHOWS WEAK TROUGHINESS DURING THIS PERIOD...SO DECIDED TO MENTION SHOWERS IN THE VICINITY FOR THE MOST PART. WILL GO MAINLY VFR BUT BRIEF IFR TO MVFR CONDITIONS ARE POSSIBLE IN SHOWERS AND THUNDERSTORMS. CAE 88D SHOWS MORE CONVECTION FIRING UP BETWEEN AGS AND OGB. EXPECT ACTIVITY TO WEAKEN AS SUN GOES DOWN AND SURFACE HEATING ENDS. AFTER MIDNIGHT...MOIST SOUTHWEST WIND FLOW WILL CONTINUE IN THE LOWER LEVELS AND IT SHOULD FAVOR MORE IFR STRATUS CEILING THAN IFR FOG. WILL GO MAINLY MVFR VSBYS WITH FOG MOST LOCATIONS TUESDAY NEAR DAYBREAK BUT WILL HAVE LOWER IFR VSBYS AT AGS AND OGB. AFTER 14Z TUESDAY MORNING...CONDITIONS SHOULD HAVE IMPROVED TO VFR AGAIN BUT WILL KEEP SHOWER IN THE VICINITY REMARKS AS MOISTURE AND UPPER FEATURES STILL SIMILAR TO THOSE TODAY. EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS POSSIBLE AGAIN WEDNESDAY MORNING AS LOW PRESSURE SYSTEM SLOWLY MOVES EAST. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ SYNOPSIS... NEAR TERM...07 SHORT TERM... LONG TERM... AVIATION...07
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
150 PM EDT MON MAY 14 2012 .SYNOPSIS... LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY MOVE EAST ACROSS THE REGION THROUGH TONIGHT. HIGH MOISTURE WILL CONTINUE AHEAD OF THIS SYSTEM. SOME DRYING IS EXPECTED TUESDAY WHICH WILL RESULT IN SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS THROUGH MIDWEEK. && .NEAR TERM /THROUGH TONIGHT/... UPPER TROUGH STILL TO THE WEST PULLING MOISTURE ACROSS THE REGION FROM THE SOUTH. BOTH OBSERVED AND FORECAST SOUNDINGS ARE NEARLY MOIST ADIABATIC WHICH SHOULD ALLOW SHOWERS TO POP UP WITH THE SLIGHTEST TRIGGER. RUC13 SHOWS WEAK TROUGH ACROSS THE REGION LATE THIS AFTERNOON INTO THE EARLY EVENING HOURS. WHILE MOST THE ACTIVITY HAS MOVED EAST...SHOWERS CAN STILL DEVELOP. CANNOT RULE OUT A THUNDERSTORM OR TWO BUT ABUNDANT MOISTURE IS EXPECTED TO LIMIT STRONG CONVECTIVE ACTIVITY FROM DEVELOPING. EXPECT RAINFALL AMOUNTS TO REMAIN ONE QUARTER INCH OR LESS IN THE WESTERN MIDLANDS AND TAPER TO LESS THAN A TENTH OF AN INCH OVER THE EASTERN MIDLANDS THROUGH THIS AFTERNOON...MAINLY DUE TO A LACK OF FORCING. TONIGHT...THE UPPER TROUGH WILL BE SLOW MOVING AS IT MOVES INTO THE REGION AND WILL CONTINUE TO PROVIDE UPPER SUPPORT OVERNIGHT...ESPECIALLY DURING THE EVENING HOURS...THEREFORE WILL CONTINUE WITH LIKELY POPS OVERNIGHT. THE PRECIPITABLE WATER AXIS SHIFTS OVER THE FORECAST AREA OVERNIGHT AND EXPECT THE BEST RAINFALL ACCUMULATION TO OCCUR DURING THIS PERIOD. THE WESTERN AND NORTHERN MIDLANDS WILL LIKELY SEE THE HIGHEST AMOUNTS...POSSIBLY UP TO AN INCH...BUT THE ENTIRE FORECAST AREA SHOULD SEE MODERATE MEASURABLE RAINFALL THROUGH EARLY MONDAY MORNING. TEMPERATURES TONIGHT WILL BE LIMITED BY INCREASED DEWPOINTS AND CLOUDS AND PRECIPITATION...GENERALLY IN THE MID 60S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH THE PERIOD AND SHOULD PROVIDE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS. AIR MASS APPEARS TO REMAIN MODERATELY MOIST AND INCREASINGLY UNSTABLE THROUGH THE PERIOD. SOME DRYING SUGGESTED BY MODELS ESPECIALLY GFS...HOWEVER EXPECT PRECIPITABLE WATER TO REMAIN RELATIVELY HIGH...NEAR 1.5 INCHES AT TIMES WITH PERSISTENT SOUTHWEST MOIST 850MB FLOW AHEAD OF UPPER LEVEL TROUGH ACROSS THE MISSISSIPPI VALLEY AND MIDWEST. SEVERAL SHORT WAVE TRIGGERS LIKELY TO ROTATE THROUGH THE REGION...WHICH SHOULD AID THUNDERSTORM DEVELOPMENT...HOWEVER TIMING OF WAVES DIFFICULT. FORECAST HIGH CHANCE POPS DURING THE LATE AFTERNOON AND EVENING TUESDAY...POSSIBLY LATE INTO TUESDAY NIGHT ASSOCIATED WITH POSSIBLE STRONGER SHORT WAVE. CHANCE WEDNESDAY ESPECIALLY EAST MIDLANDS WHERE DEEPER MOISTURE IS AND STRONGER UPPER LEVEL FORCING IS LOCATED. TEMPERATURES SHOULD BE WARMER TUESDAY AND WEDNESDAY WITH SOME BREAKS IN THE OVERCAST MID MORNING THROUGH EARLY AFTERNOON. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... UPPER TROUGH STILL TO THE WEST OF THE FORECAST AREA BRINGING PLENTY OF MOISTURE ON LOW LEVEL SOUTH TO SOUTHWEST WIND FLOW. AIR MASS NEARLY SATURATED WITH BOTH LAPS AND MODEL SOUNDING MOIST ADIABATIC. THIS SHOULD LIMIT THUNDERSTORM DEVELOPMENT BUT SHOWERS ARE EXPECTED TO DEVELOP ANY TIME THIS AFTERNOON THROUGH THE EARLY EVENING HOURS WITH JUST A MODEST TRIGGER. RUC13 H5 SHOWS WEAK TROUGHINESS DURING THIS PERIOD...SO DECIDED TO MENTION SHOWERS IN THE VICINITY FOR THE MOST PART. WILL GO MAINLY VFR BUT BRIEF IFR TO MVFR CONDITIONS ARE POSSIBLE IN JUST ABOUT ANY SHOWER. THUNDERSTORMS ARE ALSO POSSIBLE BUT NOT CONFIDENT ENOUGH TO PUT IN THE TAF SITES. CAE 88D SHOWS STRONGEST CONVECTIVE ACTIVITY WITH LIGHTNING WELL EAST OF TAF SITES WITH CONVECTIVE LINE WHICH MOVED THROUGH EARLIER THIS MORNING. ALSO...AIRMASS APPEARS MORE UNSTABLE TO THE EAST WITH LAPS CAPES OVER 3000 J/KG AND LAPS LIS -6/-7. MORE MODEST DYNAMICS OVER TAF SITES WITH LAPS CAPES AROUND 2000 J/KG AND LAPS LIS AROUND -5. TREND GOOD THROUGH ABOUT MIDNIGHT TONIGHT...04Z. SHOWERS ARE EXPECTED TO TAPER OFF BEFORE THEN THOUGH AROUND 01-02Z. AFTER MIDNIGHT...MOIST SOUTHWEST WIND FLOW WILL CONTINUE IN THE LOWER LEVELS AND IT SHOULD FAVOR MORE IFR STRATUS CEILING THAN IFR FOG. WILL GO MAINLY MVFR VSBYS WITH FOG MOST LOCATIONS TUESDAY NEAR DAYBREAK BUT WILL HAVE LOWER IFR VSBYS AT AGS AND OGB. AFTER 14Z TUESDAY MORNING...CONDITIONS SHOULD HAVE IMPROVED TO VFR AGAIN BUT WILL KEEP SHOWER IN THE VICINITY REMARKS AS MOISTURE AND UPPER FEATURES STILL SIMILAR TO THOSE TODAY. EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS POSSIBLE AGAIN WEDNESDAY MORNING AS LOW PRESSURE SYSTEM SLOWLY MOVES EAST. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
636 PM EDT MON MAY 14 2012 .SYNOPSIS... LOW PRESSURE WILL MOVE UP THE EAST COAST TONIGHT, AND SPREAD RAIN INTO THE AREA THROUGH TUESDAY, BEFORE ENDING LATE TUESDAY AND TUESDAY NIGHT. SKIES WILL CLEAR BRIEFLY LATE TUESDAY AND EARLY WEDNESDAY AHEAD OF A COLD FRONT. THIS FRONT WILL MOVE THROUGH LATE WEDNESDAY WITH SHOWERS. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND BRING DRY WEATHER FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 625 PM UPDATE... MINOR ADJUSTMENTS...MOSTLY FOR THE SPEED AND COVERAGE OF THE RAIN. IN GENERAL FORECAST ON TRACK. RAINFALL AMOUNTS SO FAR UNDER AN INCH. PREVIOUS DISCUSSION... MODELS STILL RESOLVING THE UPCOMING RAIN EVENT. OPERATIONAL NAM HAS GONE BACK TO IT/S EARLIER SOLN AND BRINGS RAIN BACK TO THE WEST WITHOUT GENERATING THE QPF BULLSEYE OVER THE ERN ZONES. SREF MEAN SOLN IS MORE IN LINE WITH THE OPERATIONAL GFS WHICH HAS A PCPN MAX OVER THE UPSLOPE AREAS IN THE CATSKILLS AND POCONOS. HWVR...GFS MAX ACCUMULATED QPF OF OVER 4.5 INCHES SEEMS TOO HIGH...AND MODEL MAY BE SUFFERING FROM CONV FEEDBACK WITH STRONG STORMS FIRING OVER THE SE. SYSTEM HAS GOOD JET STRUCTURE WITH UPR DIVERGENCE IN THE RR QUAD AND GOOD LL SLY INFLOW. PWATS APRCHS 2" OVER THE EAST CST...A BIT LESS OVER THE FCST AREA. CONSENSUS AVGD QPF PUTS 30 HR AMTS OVER THE WRN CATS APRCHG 2 INCHES...WELL BLO FFG AND HEADWATERS GUID. AREA HAS ACTUALLY BEEN A BIT DRY AND HAS SOME OF THE HIGHEST GUID IN THEN FCST AREA. SO...AFTER XTNSV COORD WITH SURROUNDING OFFICES HAVE DECIDED TO HOLD OFF ON A WATCH ATTM. WILL KEEP HWO GOING WITH A MENTION OF PTNL PRBLMS IF AMTS ARE HIGHER. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... OLD FNT IS SLOW TO MVE AS YET ANOTHER WV RIDES UP ON TUE...SLOWING THE EWRD ADVANCE. LOOKS LIKE SOME HEAVIER RAIN COULD LINGER IN THE EAST THRU ABT 18Z TUE AS THE WV PASSES. STILL...BNDRY REMAINS NEARLY STATIONARY INTO EARLY WED BEFORE A STRONGER SHRT WV AND SFC FNT APRCHS FROM THE WEST AND PUSHES IT ALONG. WED/S FNT DOES NOT HAVE THE MOISTURE CONNECTION THAT TUE/S DOES...SO DESPITE GOOD LL CONVERGENCE AND SUPPORT ALOFT...FNT MAY NOT GENERATE ALL THAT MUCH PCPN. SOME MRGNL INSTABILITY DOES BRING THE CHANCE OF CONV WITH THE FNT...ESP OVER THE NORTH NEAR THE BETTER DYNAMICS AND SOME POOLED LL MOISTURE. MUCH COOLER AND DRIER AIR FOLLOWS THE FNT ON THU AS A SFC HIPRES BLDS INTO THE OH VLY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... IMPRVMNT WITH A WARMING TREND FOR THE MEDIUM RNG AS THE NE U.S. TROF BEGINS TO PULL OUT AND UPR LVL/SFC RIDGING COMMENCES. BY LATER IN THE WEEKEND THE PTRN DOES BCM MORE FVRBL FOR THE DVLPMNT OF SOME ISOLD/WDLY SCT -TSRA MAINLY DUE TO DIURNAL EFFECTS...AND THE PREV 00Z EURO SUGGESTED SOME POTNL FOR MCS ACTIVITY WITH SYSTEMS DROPPING OUT OF CANADA OVER THE WEEKEND. GFS NOT SHOWING THIS...AND INDEED HPC POPS INDICATE A DRY FCST UNTIL MONDAY OF NXT WEEK. WE SEE NO REASON TO TO DISAGREE. WE DID GO MORE OPTIMISTIC WITH THE SKY COVER THAN THE HPC FCST...WITH GNRLY PARTLY SUNNY/PARTLY CLOUDY SKIES THRU THE PD. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... WDSPRD RESTRICTIONS ACRS THE FCST AREA THRU 18Z TUE DUE TO CIGS/RAIN/BR. IT IS A TUFF CALL AT RME/SYR BUT XPCT POTNL FOR MVFR THIS AFTN...SPCLY AT RME...THEN GNRL MVFR OVRNGT WITH THESE SITES ON THE PERIPHERY OF THE STEADIER RAIN SHIELD. OTRW...IFR (PSBL LIFR AT ITH/BGM/AVP) AND SOME MVFR IN RAIN AND MIST. HEAVIER RAINS ARE XPCTD TO PULL OUT ON TUE MRNG...BUT LOW CIGS AND BR XPCTD TO PERSIST THRU 18Z. WINDS THIS AFTN GNRLY S TO SE ARND 5 KTS...THEN SELY 5-10 KTS TNGT INTO MON MRNG. .OUTLOOK... TUE NGT...LINGERING MVFR AT AVP...VFR ELSEWHERE WITH PONTL FOR VLY FOG LATE AFFECTING ELM. WED...MAINLY VFR...WDLY SCT AFTN -TSRA WITH MVFR PSBL. THU/FRI/SAT...VFR...XCPT LATE NGT VLY FOG AFFECTING ELM. && .HYDROLOGY... IN GENERAL FLASH FLOOD AND HEADWATER GUID BLO FCSTD QPF FROM NEARLY ALL SOURCES. OUTLIER IS THE GFS WICH DROPS A 30 HR TTL OF ARND 4.5 INCHES OVER THE UPR DELAWARE BASIN. THAT AMT WLD CAUSE FLOODING ISSUES BUT CONSENSUS IS THAT THE MODEL IS SUFFERING SOME CONV FEEDBACK ISSUES. HWVR...PLACEMENT FROM THE GFS SEEMS CORRECT SO BEST LOCATION FOR THE HIGHEST QPF APPEARS TO BE OVER ERN DELAWARE AND NRN SULLIVAN...IN THE DELAWARE BASIN. HERE THE TOTAL QPF IS 2 TO 2.5 INCHES WHICH COULD CAUSE MINOR FLOODING OF THE FLASHIER CREEKS AND STREAMS SUCH AS THE WEST BRANCH AT WALTON. TO THE WEST OVER THE UPR AND NORTH BRANCH SUSQ BASINS...AVERAGED AMTS WILL BE LESS SO RVRS SHD STAY WELL BLO FLOOD STAGE. FOR THE FINGER LAKES AND CHEMUNG BASINS AMOUNTS AN INCH OR LESS SO NO PROBLEMS EXPECTED. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DGM NEAR TERM...DGM/TAC SHORT TERM...DGM LONG TERM... AVIATION... HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
326 PM EDT MON MAY 14 2012 .SYNOPSIS... LOW PRESSURE WILL MOVE UP THE EAST COAST TONIGHT AND SPREAD RAIN INTO THE AREA THROUGH TUESDAY. SKIES WILL CLEAR BRIEFLY LATE TUESDAY AND EARLY WEDNESDAY AHEAD OF A COLD FRONT. THIS FRONT WILL MOVE THROUGH LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND BRING DRY WEATHER FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... MODELS STILL RESOLVING THE UPCOMING RAIN EVENT. OPERATIONAL NAM HAS GONE BACK TO IT/S EARLIER SOLN AND BRINGS RAIN BACK TO THE WEST WITHOUT GENERATING THE QPF BULLSEYE OVER THE ERN ZONES. SREF MEAN SOLN IS MORE IN LINE WITH THE OPERATIONAL GFS WHICH HAS A PCPN MAX OVER THE UPSLOPE AREAS IN THE CATSKILLS AND POCONOS. HWVR...GFS MAX ACCUMULATED QPF OF OVER 4.5 INCHES SEEMS TOO HIGH...AND MODEL MAY BE SUFFERING FROM CONV FEEDBACK WITH STRONG STORMS FIRING OVER THE SE. SYSTEM HAS GOOD JET STRUCTURE WITH UPR DIVERGENCE IN THE RR QUAD AND GOOD LL SLY INFLOW. PWATS APRCHS 2" OVER THE EAST CST...A BIT LESS OVER THE FCST AREA. CONSENSUS AVGD QPF PUTS 30 HR AMTS OVER THE WRN CATS APRCHG 2 INCHES...WELL BLO FFG AND HEADWATERS GUID. AREA HAS ACTUALLY BEEN A BIT DRY AND HAS SOME OF THE HIGHEST GUID IN THEN FCST AREA. SO...AFTER XTNSV COORD WITH SURROUNDING OFFICES HAVE DECIDED TO HOLD OFF ON A WATCH ATTM. WILL KEEP HWO GOING WITH A MENTION OF PTNL PRBLMS IF AMTS ARE HIGHER. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... OLD FNT IS SLOW TO MVE AS YET ANOTHER WV RIDES UP ON TUE...SLOWING THE EWRD ADVANCE. LOOKS LIKE SOME HEAVIER RAIN COULD LINGER IN THE EAST THRU ABT 18Z TUE AS THE WV PASSES. STILL...BNDRY REMAINS NEARLY STATIONARY INTO EARLY WED BEFORE A STRONGER SHRT WV AND SFC FNT APRCHS FROM THE WEST AND PUSHES IT ALONG. WED/S FNT DOES NOT HAVE THE MOISTURE CONNECTION THAT TUE/S DOES...SO DESPITE GOOD LL CONVERGENCE AND SUPPORT ALOFT...FNT MAY NOT GENERATE ALL THAT MUCH PCPN. SOME MRGNL INSTABILITY DOES BRING THE CHANCE OF CONV WITH THE FNT...ESP OVER THE NORTH NEAR THE BETTER DYNAMICS AND SOME POOLED LL MOISTURE. MUCH COOLER AND DRIER AIR FOLLOWS THE FNT ON THU AS A SFC HIPRES BLDS INTO THE OH VLY. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... IMPRVMNT WITH A WARMING TREND FOR THE MEDIUM RNG AS THE NE U.S. TROF BEGINS TO PULL OUT AND UPR LVL/SFC RIDGING COMMENCES. BY LATER IN THE WEEKEND THE PTRN DOES BCM MORE FVRBL FOR THE DVLPMNT OF SOME ISOLD/WDLY SCT -TSRA MAINLY DUE TO DIURNAL EFFECTS...AND THE PREV 00Z EURO SUGGESTED SOME POTNL FOR MCS ACTIVITY WITH SYSTEMS DROPPING OUT OF CANADA OVER THE WEEKEND. GFS NOT SHOWING THIS...AND INDEED HPC POPS INDICATE A DRY FCST UNTIL MONDAY OF NXT WEEK. WE SEE NO REASON TO TO DISAGREE. WE DID GO MORE OPTIMISTIC WITH THE SKY COVER THAN THE HPC FCST...WITH GNRLY PARTLY SUNNY/PARTLY CLOUDY SKIES THRU THE PD. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... WDSPRD RESTRICTIONS ACRS THE FCST AREA THRU 18Z TUE DUE TO CIGS/RAIN/BR. IT IS A TUFF CALL AT RME/SYR BUT XPCT POTNL FOR MVFR THIS AFTN...SPCLY AT RME...THEN GNRL MVFR OVRNGT WITH THESE SITES ON THE PERIPHERY OF THE STEADIER RAIN SHIELD. OTRW...IFR (PSBL LIFR AT ITH/BGM/AVP) AND SOME MVFR IN RAIN AND MIST. HEAVIER RAINS ARE XPCTD TO PULL OUT ON TUE MRNG...BUT LOW CIGS AND BR XPCTD TO PERSIST THRU 18Z. WINDS THIS AFTN GNRLY S TO SE ARND 5 KTS...THEN SELY 5-10 KTS TNGT INTO MON MRNG. .OUTLOOK... TUE NGT...LINGERING MVFR AT AVP...VFR ELSEWHERE WITH PONTL FOR VLY FOG LATE AFFECTING ELM. WED...MAINLY VFR...WDLY SCT AFTN -TSRA WITH MVFR PSBL. THU/FRI/SAT...VFR...XCPT LATE NGT VLY FOG AFFECTING ELM. && .HYDROLOGY... FFG AND HEADWATER GUID BLO FCSTD QPF FROM NEARLY ALL SOURCES. OUTLIER IS THE GFS WICH DROPS A 30 HR TTL OF ARND 4.5 INCHES OVER THE UPR DELAWARE BASIN. THAT AMT WLD CAUSE FLOODING ISSUES BUT CONSENSUS IS THAT THE MODEL IS SUFFERING SOME CONV FEEDBACK ISSUES. HWVR...PLACEMENT FROM THE GFS SEEMS CORRECT SO BEST LOCATION FOR THE HIGHEST QPF APPEARS TO BE OVER ERN DELAWARE AND NRN SULLIVAN...IN THE DELAWARE BASIN. TO THE WEST OVER THE UPR SUSQ BASIN...AVERAGED AMTS WILL BE CONSIDERABLY LESS SO RVRS SHD STAY WELL BLO FLOOD STAGE. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DGM NEAR TERM...DGM SHORT TERM...DGM LONG TERM... AVIATION... HYDROLOGY...DGM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1229 PM CDT MON MAY 14 2012 .DISCUSSION...SEE AVIATION SECTION BELOW. && .AVIATION...CLOUDS AROUND 15K FT ARE MOVG ACROSS S TX WITH A LOWER DECK DVLPG AROUND 4K FT. EXPECTING VFR CONDITIONS THROUGH THE REMAINDER OF THE DAY AND INTO THE EVENING HOURS. AN UPPER DISTURBANCE WILL BRING SHRA`S/TSRA`S FROM THE BIG BEND AREA DOWN INTO THE RIO GRANDE PLAINS TONIGHT AND ACROSS S TX OVERNIGHT AND INTO TUE. MVFR/IFR CONDITIONS ARE EXPECTED IN AND AROUND THE PRECIP LATE TONIGHT INTO TUE. && .PREV DISCUSSION... /ISSUED 946 AM CDT MON MAY 14 2012/ DISCUSSION...THE REMAINS OF AN MCS IS WEAKENING AS IT MOVES SOUTHEAST ACROSS THE WESTERN CWA. MOST MODELS DID NOT EVEN PICK UP ON THIS PRECIP...HOWEVER THE LATEST RUC13 HAS AND IT SHOWS THE PRECIP DISSIPATING OVER THE NEXT COUPLE OF HOURS...MAINLY DUE TO A SLIGHTLY SUBSIDENT/DRIER AIRMASS IN PLACE ACROSS THE E CWA. ONLY CONCERN IS THAT THIS PRECIP IS HEADING TOWARD AN AREA OF LESS CIN/HIGHER CAPE ACROSS THE E CWA. FOR NOW...WILL LEAVE POPS AS IS FOR TODAY UNLESS THIS SYSTEM RE-INTENSIFIES. REST OF FCST LOOKS ON TRACK. NO MAJOR CHANGES TO THE FCST AT THIS TIME. PREV DISCUSSION... /ISSUED 724 AM CDT MON MAY 14 2012/ DISCUSSION...INTRODUCED SLIGHT END POPS UNTIL 18Z ACROSS THE RIO GRANDE PLAINS AS MCS CONTINUES TO MOVE SOUTHEAST THIS MORNING. UPDATED PRODUCTS OUT. PREV DISCUSSION... /ISSUED 659 AM CDT MON MAY 14 2012/ DISCUSSION...UPDATED FOR 12Z AVIATION AVIATION...LINGERING CONVECTION OVER MAVERICK COUNTY SHOULD CONTINUE TO MOVE EAST...BUT SHOULD NOT IMPACTING THE TERMINALS. OTHERWISE...VFR CONDITIONS TO PERSIST THROUGH TODAY. UPPER LEVEL DISTURBANCE AND CHANCES FOR CONVECTION WILL INCREASE TONIGHT FROM THE NORTHWEST. INCLUDED VCTS REMARKS AT LRD IN ANTICIPATION OF MCS DEVELOPING TONIGHT. DID NOT INCLUDE AT THE OTHER TERMINALS ATTM. WINDS GENERALLY REMAIN LESS THAN 12 KNOTS AT ALI/CRP/VCT...BUT MAY BECOME A LITTLE GUSTY IN THE AFTERNOON AT LRD. PREV DISCUSSION... /ISSUED 409 AM CDT MON MAY 14 2012/ SHORT TERM (TODAY THROUGH TUESDAY)...LATEST RADAR TRENDS SHOW WEAKENING MCS OVER THE BIG BEND OF TEXAS. ANTICIPATE THIS CONVECTION WILL NOT MAKE IT INTO LA SALLE AND WEBB COUNTIES SO WILL KEEP POPS SILENT FOR THE MORNING HOURS. UPPER LEVEL TROUGH WILL DROP SOUTHEAST OUT OF NEW MEXICO TODAY AND TONIGHT. MOISTURE FIELDS BEGIN TO INCREASE BY THIS EVENING. HIGH RESOLUTION MODELS DEVELOP ANOTHER MCS OVER THE BIG BEND TONIGHT WITH IT TRACKING FURTHER TO THE SOUTHEAST...APPROACHING THE NORTHWESTERN ZONES BETWEEN 03Z AND 06Z TUESDAY. IF STORMS ARE ABLE TO MAINTAIN THEIR STRENGTH...THEN PERHAPS A DAMAGING WIND GUST THREAT COULD EMERGE...BUT CONFIDENCE OF THIS OCCURRING IS ON THE LOW SIDE. WENT AHEAD AND INCREASED POPS ACROSS LA SALLE AND WEBB COUNTIES TO 60 PERCENT...TAPERING OFF TO 20 PERCENT OVER THE COASTAL WATERS FOR THE TONIGHT PERIOD. HIGHER RAINFALL AMOUNTS SHOULD OCCUR NORTH OF THE AREA. UPPER TROUGH WEAKEN A BIT AS IT CONTINUES TO MOVE TO THE SOUTHEAST ON TUESDAY. NAM/GFS IN DECENT AGREEMENT ON PRECIP CHANCES AND HAVE RAISED THEM A LITTLE. CLOUD COVER AND CHANCES FOR PRECIP WILL KEEPS TEMPS DOWN ON TUESDAY... MAINLY IN THE LOWER 80S. FAVORED THE COOLER METMOS TEMPS. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ANY PRECIP THAT EXISTS AT START OF LONG TERM PERIOD SHOULD END FROM NORTH TO SOUTH AS UPPER LEVEL TROUGH AXIS SWINGS SOUTH OF CWA AND SURFACE HIGH PRESSURE BUILDS INTO AREA. 00Z ECMWF IS ABOUT SIX HRS SLOWER THAN GFS WITH MOVEMENT OF SYSTEM AND A LINGERING CHANCE OF PRECIP MAY BE NEEDED IN LATER FORECAST PKGS IF SYSTEM SLOWS...BUT FOR NOW WILL LEAVE WED DRY. QUIET WX THEN EXPECTED FOR SECOND HALF OF WORK WEEK AS WEAK MID/UPPER LEVEL RIDGING DEVELOPS RESULTING IN WNW FLOW ALOFT AND LIMITED DEEP LAYER MOISTURE. BY NEXT WEEKEND GFS AND ECMWF DIFFER SOMEWHAT WITH MID/UPPER LEVEL PATTERN. GFS HAS MORE ZONAL FLOW WITH ELONGATED MID LEVEL RIDGING WHILE ECMWF HAS MORE PRONOUNCED S/W TROUGHS MOVING ACROSS THE PLAINS. BOTH GUIDANCE SUITES INITIATE SURFACE CYCLOGENESIS ACROSS THE NORTHERN SOUTH HIGH PLAINS AND DIURNAL SFC TROUGHING WHICH IN TURN SHOULD TIGHTEN THE PRESSURE GRADIENT ACROSS S TX AND ALLOW LOW LEVEL MOISTURE ADVECTION TO INCREASE. LOW LEVEL MOISTURE VALUES AND WIND PROFILE MAY BECOME MORE CONDUCIVE FOR ISOLATED STREAMER SHOWERS ACROSS MARINE ZONES AND COASTAL PLAINS BY LATE IN THE EXTENDED PERIOD. TEMPS ARE EXPECTED TO BE AT OR SLIGHTLY ABOVE SEASONABLE VALUES /EXCEPT AROUND MID WEEK WHERE BELOW NORMAL MIN TEMPS MAY OCCUR WHEN HIGH PRESSURE CENTER IS THE CLOSEST/ AND HAVE GENERALLY GONE CLOSE TO A BIAS CORRECTED MOSGUIDE/ECMWF BLEND. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 86 68 82 64 86 / 10 30 50 20 10 VICTORIA 86 64 80 60 86 / 10 30 50 20 10 LAREDO 92 69 86 67 91 / 20 50 50 20 10 ALICE 89 66 84 61 88 / 10 30 50 20 10 ROCKPORT 86 71 80 68 86 / 10 30 50 20 10 COTULLA 88 64 82 60 89 / 20 60 50 10 10 KINGSVILLE 88 68 84 62 87 / 10 30 50 30 10 NAVY CORPUS 84 71 82 68 84 / 10 30 50 30 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ TE/81...SHORT TERM GW/86...LONG TERM