Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/04/12


AREA FORECAST DISCUSSION
NWS DENVER CO
742 PM MDT FRI AUG 3 2012 .UPDATE...GUSTY WEST WINDS HAVE SPREAD ACROSS THE URBAN CORRIDOR AHEAD OF A COLD FRONT THAT IS JUST ENTERING NORTHEAST COLORADO. THIS FRONT WILL SWEEP SOUTH THROUGH THE EVENING HOURS...PASSING THROUGH THE DENVER AREA AROUND 10 PM. AIRMASS IS QUITE DRY ACROSS THE FORECAST AREA WITH DEW POINTS IN THE 20S AND 30S. THERE IS GOOD QG LIFT OVER THE AREA AT THIS TIME WHICH IS PRODUCING MID AND UPPER LEVEL CLOUDS. A FEW SHORT LIVED SHOWERS AND A THUNDERSTORM HAVE FORMED OVER SOUTHERN WYOMING BEHIND THE FRONT IN THE DRY AIRMASS. BECAUSE OF THE LIFT BEHIND THE FRONT AND MID AND UPPER LEVEL LIFT IN PLACE...ADDED A SLIGHT CHANCE FOR SHOWERS AND STORMS TO THE FORECAST THIS EVENING FOR THE DENVER METRO AREA. IF ANY THING DEVELOPS IT WOULD BE BEHIND THE FRONT AND SHORT LIVED. THE LAST RAP MODEL IS SHOWING WEAK QPF BEHIND THE FRONT...WHICH SUPPORTS THE IDEA OF A FEW SHOWERS OR STORMS BEHIND THE FRONT. THERE IS A BOUNDARY OVER EASTERN COLORADO...EAST OF IT DEW POINTS ARE IN THE 40S AND LOWER 50S. ONCE THE FRONT RUNS INTO THE MORE MOIST AIRMASS...EXPECT SCATTERED THUNDERSTORMS TO FORM. MOST OF THESE WILL BE EAST OF THE FORECAST AREA BUT A FEW MAY CLIP WASHINGTON...LINCOLN...PHILLIPS AND SEDGEWICK COUNTIES. DID INCREASE POPS TO AROUND 50 PERCENT FOR THE FAR EASTERN PARTS OF THE FORECAST AREA. && .AVIATION...GUSTY WEST WINDS WILL TURN NORTH-NORTHEAST BETWEEN 04Z AND 05Z AS A COLD FRONT PUSHES THROUGH THE AREA. THERE IS A SLIGHT CHANCE FOR A THUNDERSTORM BEHIND THE FRONT UNTIL 07Z. MOISTURE WILL INCREASE BEHIND THE FRONT AND PRODUCE LOW CLOUDS FROM ABOUT 09Z TO 15Z. CEILING ARE EXPECTED TO BE IN THE 3000 TO 6000 FEET RANGE. && .PREV DISCUSSION... /ISSUED 244 PM MDT FRI AUG 3 2012/ SHORT TERM...A COLD FRONT ASSOCIATED WITH AN UPPER LEVEL TROUGH MOVING ACROSS MONTANA AND INTO NORTH DAKOTA WILL USHER A BONAFIDE COLD FRONT INTO THE FRONT RANGE FOOTHILLS...URBAN CORRIDOR AND NORTHEAST PLAINS THIS EVENING. ISOLATED THUNDERSTORMS ON THE FRINGE OF AN UPPER LEVEL JET MAX OF 80 KTS OVER SOUTHERN WYOMING WILL PERSIST OVER GRAND...JACKSON AND LARIMER COUNTIES THROUGH EARLY THIS EVENING. THE GOES SOUNDER TOTAL PRECIPITABLE WATER IS MUCH DRIER IN THE LOWER LEVELS OVER THE NORTHERN HALF OF THE CWFA. AS A RESULT...THOSE STORMS WILL BE HIGH BASED WITH GUSTY WINDS AND LIGHTNING THE MAIN THREATS. ELSEWHERE...THERE WILL BE SLIGHTLY BETTER MOISTURE IN THE LOWER LEVELS WITH EITHER AFTERNOON HEATING OR THE INCOMING FRONT PROVIDING ENOUGH LIFT FOR A FEW STORMS MAINLY EAST AND SOUTH OF THE DENVER AREA THIS EVENING. ON SATURDAY...IT WILL BE MUCH COOLER WITH TEMPERATURES 10-15 DEGREES LESS THAN TODAY. THE AIRMASS WILL BE TOO STABLE AS WELL. THE NAM12 SPATIAL CROSS-SECTIONS DO INCREASE THE MOISTURE ALONG THE FRONT RANGE AND PALMER DIVIDE FOLLOWING THE COLD FRONT SO A FEW SPRINKLES POSSIBLE SATURDAY MORNING. THE ONLY AREA WITH ENOUGH MOISTURE AND INSTABILITY IN THE AFTERNOON FOR TSTMS WILL BE IN AND AROUND PARK COUNTY SO WILL KEEP ISOLD TSTMS THERE. LONG TERM...AN UPPER LEVEL RIDGE WILL BEGIN TO BUILD BACK INTO THE AREA ON SUN WITH SUBTROPICAL MOISTURE CONFINED MAINLY TO SRN COLORADO. THUS WILL ONLY MENTION LOW POPS OVER THE HIGHER TERRAIN ALONG AND SOUTH OF I-70. OVER NERN CO THERE IS SOME FAVORABLE CAPE HOWEVER CAP IS RATHER STG WHICH WILL LIKELY INHIBIT CONVECTION. FOR HIGHS WILL KEEP READINGS IN THE UPPER 80S TO LOWER 90S ACROSS THE PLAINS. BY MON AN UPPER LEVEL HIGH WILL BE CENTERED OVER COLORADO WITH WEAK FLOW ALOFT. SOME SUBTROPICAL MOISTURE WILL BEGIN TO ROTATE AROUND THE HIGH WHICH WILL LEAD TO AT LEAST A SLIGHT CHC OF STORMS OVER THE HIGHER TERRAIN. OVER NERN CO CURRENT SOUNDINGS SHOW VERY LITTLE CAPE SO WILL NOT MENTION ANY TSTMS. HIGHS ON MON WILL CONTINUE TO RISE WITH READINGS IN THE MID TO UPPER 90S ACROSS THE PLAINS. ON TUE THE UPPER LEVEL HIGH WILL BEGIN TO SHIFT SLOWLY WESTWARD WITH THE FLOW ALOFT BECOMING MORE WNW AS A WK DISTURBANCE MOVES ACROSS. THUS SHOULD STILL SEE A CHC OF TSTMS IN MTNS WITH A SLIGHT CHC OVER THE PLAINS. HIGHS ON TUE WILL STILL BE IN THE 90S ACROSS NERN CO. FOR WED AND THU THE UPPER LEVEL HIGH WILL BE CENTERED OVER WRN CO WITH A SOMEWHAT DRIER AIRMASS WITH LIMITED CAPE. THUS APPEARS TSTM ACTIVITY MAY BECOME MORE ISOLD TO WDLY SCT OVER THE HIGHER TERRAIN WITH NO ACTIVITY OVER NERN CO. TEMPS BOTH DAYS WILL REMAIN IN THE 90S ACROSS THE PLAINS. AVIATION...OVERALL VFR CONDITIONS WILL PREVAIL. A COLD FRONT EXPECTED TO MOVE INTO THE DENVER AREA IN THE 03-05Z TIME FRAME SO THE TIMING MAY NEED TO BE ADJUSTED FURTHER IN THE UPCOMING TAFS. WINDS HAVE BEEN WAFFLING BETWEEN WEST/NORTHWEST AND SOUTH THIS AFTERNOON AND WILL LIKELY CONTINUE TO DO SO OVER THE NEXT HOUR OR TWO. WINDS WILL BECOME NORTHWESTERLY JUST AHEAD OF THE COLD FRONT THEN NORTHEAST FOLLOWING FROPA. LOWER LEVEL MOISTURE IS EXPECTED TO INCREASE AFTER 06Z WITH BKN CIGS OF 040-060 DEVELOPING IN THE 09Z-15Z TIME FRAME. HYDROLOGY...NO FLOODING CONCERNS FOR THE BURN AREAS TONIGHT OR SATURDAY. THE LOWER LEVEL WILL BE MUCH DRIER SO GUSTY WINDS AND LIGHTNING THE MAIN ISSUES THIS EVENING. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COOPER LONG TERM....RPK UPDATE/AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS PUEBLO CO
328 PM MDT THU AUG 2 2012 .SHORT TERM... (TONIGHT AND FRIDAY) THE MONSOON MOISTURE PLUME REMAINS OVER THE AREA WITH SHOWERS AND THUNDERSTORMS OVER AND NEAR THE MOUNTAINS EARLY THIS AFTERNOON. THE MODELS ARE SHOWING THE CONVECTIVE ACTIVITY SPREADING ACRS THE PLAINS LATE THIS AFTERNOON THROUGH THE EVENING HOURS...IN ASSOCIATION WITH A WEAK DISTURBANCE WORKING ITS WAY EAST ACRS SOUTHERN CO. THE HRRR SHOWS A BAND OF PCPN COMING OFF THE MTS BY 00Z...MOVING EASTWARD ACRS THE PLAINS AND EXITING CO BY 04Z. THE NSSL 4KM WRF IS VERY SIMILAR. BASED ON THESE HIGH RES MODELS WL GO AHEAD AND END PCPN CHANCES IN THE FORECAST BY MIDNIGHT...HOWEVER BOTH THE NAM AND GFS KEEP CHANCES FOR PCPN OVR THE FAR SERN PLAINS THROUGH THE NIGHT AND INTO FRI MORNING. THERE IS THE POTENTIAL FOR HEAVY RAIN TODAY UNDER SOME OF THE STRONGER STORMS...WITH THE WALDO CANYON BURN SCARS BEING THE MOST VULNERABLE IF HEAVY RAIN DEVELOPS OVR THAT AREA. ON FRI THE BULK OF THE MONSOON MOISTURE WILL BE OVR SOUTHERN PORTIONS OF THE FORECAST AREA...AS AN UPR TROF OVR THE NRN ROCKIES FLATTENS THE RIDGE OVR OUR AREA. THUS THE BEST CHANCES FOR CONVECTIVE ACTIVITY SHOULD OCCUR OVR THE SRN HALF OF THE CWA. THE GFS HAS LITTLE IN THE WAY OF PCPN COVERAGE FOR FRI AFTERNOON...WHILE THE NAM HAS A LITTLE MORE COVERAGE OVER THE FAR SOUTHEAST PLAINS...THE SANGRES AND THE EASTERN SAN JUANS. HIGH TEMPS ON FRIDAY SHOULD BE A FEW DEGREES ABOVE NORMAL IN MOST LOCATIONS. .LONG TERM... (FRIDAY NIGHT THROUGH THURSDAY) LONGER TERM METEOROLOGICAL ISSUES CONTINUE TO BE POPS AND TEMPERATURES. LATEST COMPUTER SOLUTIONS INDICATE THAT STRONG UPPER RIDGE CENTERED OVER NORTHWESTERN TEXAS AT 00Z SATURDAY WILL BEGIN TO PUSH WEST INTO NEW MEXICO BY LATER SUNDAY BEFORE BECOMING CENTERED NEAR THE 4-CORNERS REGION BY NEXT TUESDAY. IN ADDITION...HEALTHY NORTHERLY SURGE IS PROJECTED TO PUSH ACROSS EASTERN SECTIONS OF THE FORECAST DISTRICT BY SATURDAY MORNING. ENOUGH ATMOSPHERIC MOISTURE IS EXPECTED TO REMAIN AVAILABLE OVER THE FORECAST DISTRICT AND COMBINE WITH OCCASIONAL UPPER WAVES AND THE DAILY HEATING CYCLE/SURFACE BOUNDARIES TO ALLOW DAILY ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER THE HIGHER TERRAIN REGIONS. SOME OF THE STRONGER THUNDERSTORMS ARE EXPECTED TO PRODUCE PERIODS OF LOCALLY HEAVY RAINFALL CAPABLE OF PRODUCING LOCALIZED FLASH FLOODING ISSUES...ESPECIALLY IF A STORM DIRECTLY IMPACTS BURN SCAR AREAS...SUCH AS THE WALDO BURN SCAR. IN ADDITION...THE STRONGER STORMS WILL ALSO BE CAPABLE OF PRODUCING HAZARDOUS LIGHTNING...HAIL AND GUSTY WINDS. FINALLY...BELOW SEASONAL MAXIMUM TEMPERATURES SHOULD BE NOTED IN THE WAKE OF THE STRONG NORTHERLY SURGE SATURDAY(ESPECIALLY EASTERN SECTIONS) WITH MAXIMUM TEMPERATURES THEN REBOUNDING TO ABOVE EARLY AUGUST SEASONAL AVERAGES NEXT WEEK. && .AVIATION... KALS...KCOS AND KPUB WILL HAVE VFR CONDITIONS MOST OF THE TIME DURING THE NEXT 24 HRS. THERE WILL BE A CHANCE FOR SHOWERS AND THUNDERSTORMS AT OR IN THE VCNTY OF THE TAF SITES THROUGH AROUND 03Z. THUNDERSTORMS COULD BRING BRIEF MVFR CONDITIONS TO THE TAF SITES. OUTFLOW WINDS COULD ALSO BRING WIND GUSTS UP TO 45 KTS. ON FRIDAY AFTERNOON WE COULD SEE SOME THUNDERSTORMS IN THE VCNTY OF THE TAF SITES AFTER 20Z...BUT CONFIDENCE IS LOW. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
155 PM EDT THU AUG 2 2012 .SYNOPSIS... 17Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW THE SOUTHEASTERN CONUS AND EASTERN GULF UNDERNEATH A SUBTLE HEIGHT WEAKNESS BETWEEN A DOMINANT UPPER RIDGE OVER THE SOUTHERN PLAINS AND ANOTHER RIDGE OVER CUBA/BAHAMAS. AT THE SURFACE...SUBTROPICAL RIDGE AXIS EXTENDS ACROSS THE SOUTH-CENTRAL FLORIDA PENINSULA PROVIDING A LIGHT LOW LEVEL FLOW OUT OF THE SW TO THE MAJORITY OF THE FORECAST AREA. && .SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)... TONIGHT...SUBTROPICAL RIDGE AXIS BEGINS TO SHIFT SLOWLY NORTHWARD OVER THE FLORIDA PENINSULA/EASTERN GULF IN RESPONSE TO THE APPROACH OF A WEAK INVERTED TROUGH/WAVE TO THE EAST OF THE BAHAMAS. MAINLY INLAND SCT CONVECTION EARLY THIS EVENING SHOULD DISSIPATE WITHIN A COUPLE HOUR OF SUNSET SETTING UP DRY CONDITIONS FOR MUCH OF THE AREA FROM LATE NIGHT INTO THE EARLY MORNING HOURS. WITH THE UPPER HEIGHT WEAKNESS STILL IN PLACE OVER THE EASTERN GULF...WOULD EXPECT TO SEE AT LEAST SOME DEGREE OF NOCTURNAL CONVECTION REDEVELOP TOWARD DAWN OVER THE COASTAL WATERS. THE RIDGE AXIS LIFTING NORTH WILL ALSO SHIFT THE FAVORED SW FLOW NORTH...SO WOULD ANTICIPATE THE MAJORITY OF THIS ACTIVITY TO DEVELOP OVER THE NORTHERN WATERS/ALONG THE NATURE COAST. FURTHER SOUTH (SOUTH OF TAMPA BAY)...A 1000-700MB FLOW MORE PARALLEL TO THE COAST (OR EVEN SOUTHEASTERLY) SHOULD GENERALLY KEEP ANY ISOLATED CELLS FROM MIGRATING BACK TO THE BEACHES. FRIDAY...TYPICAL EARLY AUGUST CONDITIONS ARE EXPECTED FOR THE FINAL DAY OF THE WORK WEEK. WILL BE CONTINUING TO WATCH THE SLOW APPROACH OF A WEAK SURFACE TROUGH TOWARD THE FLORIDA EAST COAST...HOWEVER MUCH OF THE LOW LEVEL FOCUS ASSOCIATED WITH THIS FEATURE WILL REMAIN TO OUR EAST DURING THE FAVORED DIURNAL CONVECTIVE MAX TIME-FRAME. 1000-700MB FLOW WILL INITIALLY BE QUITE LIGHT AHEAD OF THIS TROUGH ALLOWING THE WEST COAST SEA-BREEZE TO BE THE DOMINANT TRIGGER FOR ISOLATED-SCT CONVECTION NEAR THE COAST IN THE EARLY AFTERNOON. LATER IN THE DAY...AS THE TROUGH GETS A BIT CLOSER...THE FLOW WILL TRANSITION MORE EASTERLY. WITH THIS IN MIND...IT IS LIKELY THAT THE SEA-BREEZE WILL BE SIGNIFICANTLY SLOWED IN ITS INLAND PROPAGATION. THE ENHANCED LOW LEVEL CONVERGENCE MAY ALLOW FOR A FEW STRONGER UPDRAFTS/PRECIPITATION LOADING AND A RESULTING ISOLATED CONVECTIVE WIND THREAT. UNLIKE PREVIOUS DAYS...THIS PATTERN SHOULD PREVENT THE LATE AFTERNOON DROP OFF IN CONVECTIVE COVERAGE CLOSE TO THE COAST. FRIDAY NIGHT/SATURDAY... SURFACE TROUGH OVERSPREADS THE FLORIDA PENINSULA AND BECOMES ESTABLISHED OVER THE WEST COAST DURING SATURDAY AFTERNOON. THE COMBINATION OF INCREASING COLUMN MOISTURE...AND LOW LEVEL FOCUS SHOULD HELP TO PROVIDE A CONVECTIVE ACTIVE PERIOD...ESPECIALLY DURING SATURDAY AFTERNOON/EVENING. 1000-700MB FLOW IS STRAIGHT OUT OF THE EAST AND THEREFORE QUITE FAVORABLE FOR ENHANCED CONVERGENCE ALONG THE WEST-COAST SEA-BREEZE. SIMILAR TO FRIDAY...THIS PATTERN SHOULD SUPPORT A FEW STRONGER UPDRAFTS AND THE POTENTIAL FOR SOME LOCALIZED STRONGER STORMS. && .LONG TERM (SUNDAY - NEXT WEDNESDAY)... U/L RIDGE WILL PERSIST OVER THE ATLANTIC EXTENDING OVER THE SOUTHERN PLAINS SUNDAY. U/L TROUGH WILL DIG OVER THE OHIO RIVER VALLEY MONDAY AND TEMPORARILY WEAKEN THE RIDGE OVER FLORIDA. THE U/L RIDGE WILL BUILD BACK OVER FLORIDA TUESDAY AND WEDNESDAY WITH INCREASING SUBSIDENCE AND WARMER TEMPERATURES ACROSS WEST CENTRAL AND SOUTHWEST FLORIDA. AT THE SURFACE...A TROPICAL WILL WAVE MOVE ACROSS THE PENINSULA SUNDAY INCREASING DEEP LAYER MOISTURE AND INSTABILITY. EASTERLY FLOW WILL ALLOW NUMEROUS SHOWERS AND THUNDERSTORMS TO DEVELOP WITH LOCALLY HEAVY RAIN AND GUSTY WINDS WITH THE STRONGER STORMS BOTH SUNDAY AND MONDAY. SURFACE RIDGE WILL BUILD ACROSS THE CENTRAL PENINSULA TUESDAY AND WEDNESDAY. AS THE U/L RIDGE BUILDS BACK OVER FLORIDA AND DRIER AIR ALOFT ADVECTING OVER THE FORECAST AREA...AREAL COVERAGE OF AFTERNOON SHOWERS AND THUNDERSTORMS WILL DECREASE EACH DAY. && .AVIATION... SOME SHOWERS AND STORMS VICINITY TPA...PIE AND SRQ SHOULD MOVE EAST OF TERMINALS BY 20Z. PGD...FMY AND RSW SHOULD STAY MAINLY VFR. HIGHEST PROBABILITY OF MVFR OR EVEN IFR WOULD BE AT LAL BUT CONFIDENCE NOT HIGH ENOUGH FOR TEMPO GROUPS AT THIS TIME. && .MARINE... THE SUBTROPICAL RIDGE AXIS WILL SLOWLY SHIFT NORTH OVER THE AREA THROUGH FRIDAY AND THEN REMAIN TO THE NORTH OF THE FORECAST WATERS THROUGH THE UPCOMING WEEKEND. THIS MOVEMENT WILL SHIFT SYNOPTIC FLOW FROM THE SOUTH AND SOUTHWEST TO AN EAST AND SOUTHEAST DIRECTION. LOCAL SEA-BREEZE CIRCULATIONS WILL TURN THE FLOW ONSHORE NEAR THE COAST EACH AFTERNOON. && .FIRE WEATHER... BEST RAIN CHANCES WILL BE ACROSS THE INTERIOR NEXT COUPLE OF DAYS AS WESTERLY FLOW CONTINUES. A TROPICAL WAVE WILL BRING HIGHER RAIN CHANCES TO THE GULF COAST OVER THE WEEKEND AND INTO THE FIRST PART OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... TPA 77 92 77 91 / 20 40 20 40 FMY 76 93 75 92 / 20 40 20 60 GIF 75 94 74 94 / 30 40 20 40 SRQ 76 92 75 92 / 10 40 20 40 BKV 69 93 71 92 / 20 30 20 40 SPG 79 91 79 91 / 20 30 20 40 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA AVIATION...JILLSON LONG TERM...OGLESBY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1045 AM EDT THU AUG 2 2012 .UPDATE... 14Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW THE SOUTHEASTERN CONUS AND EASTERN GULF UNDERNEATH A SUBTLE HEIGHT WEAKNESS BETWEEN A DOMINANT UPPER RIDGE OVER THE SOUTHERN PLAINS AND ANOTHER RIDGE OVER CUBA/BAHAMAS. AT THE SURFACE...SUBTROPICAL RIDGE AXIS EXTENDS ACROSS THE SOUTH-CENTRAL FLORIDA PENINSULA PROVIDING A LIGHT LOW LEVEL FLOW OUT OF THE SW TO THE MAJORITY OF THE FORECAST AREA. THE FAVORED SW FLOW FOR NOCTURNAL MARINE SHOWERS COMBINED WITH THE SYNOPTIC SUPPORT ASSOCIATED WITH THE WEAKNESS ALOFT PROVIDED THE FORCING FOR SCT-NMRS CONVECTION OVER THE NORTHERN COASTAL WATERS THIS MORNING. IN THE NEXT FEW HOURS...WILL LIKELY SEE A DECREASE IN THE COVERAGE OF CONVECTION OVER THE COASTAL WATERS AS THE SEA-BREEZE TRANSLATES THE BEST LOW LEVEL CONVERGENCE ONSHORE. ALREADY BEGINNING TO SEE THE FIRST STAGE OF SHOWERS DEVELOPING ALONG THE NATURE COAST AND SHOULD SEE THIS SCT ACTIVITY EXPAND DOWN INTO THE TAMPA BAY AREA AND SOUTHWARD BY NOON. SIMILAR TO WEDNESDAY...THE BEST CHANCES FOR SHOWERS ALONG THE COASTAL ZONES WILL BE THROUGH EARLY AFTERNOON WITH CONVECTION PUSHING FURTHER INLAND WITH THE SEA-BREEZE BY THE LATER AFTERNOON HOURS. WILL NOT COMPLETELY REMOVE POPS CLOSE TO THE COAST LATER TODAY...BUT WILL TRANSLATE WORDING FROM SCATTERED TO ISOLATED. PLENTY OF MORNING INSOLATION HAS ALLOWED TEMPERATURES TO QUICKLY REBOUND INTO THE MIDDLE AND UPPER 80S. SHOULD HAVE LITTLE TROUBLE REACHING THE LOWER 90S INLAND AND UPPER 80S TO AROUND 90 AT THE COAST FOR LOCATIONS WHICH AVOID SIGNIFICANT SHOWER ACTIVITY. CURRENT TEMPERATURE/DEWPOINT GRIDS ARE IN GOOD SHAPE AND WILL NOT BE MAKING ANY SIGNIFICANT CHANGES THROUGH THE EVENING HOURS. && .PREVIOUS (FRIDAY - SATURDAY)... PERSISTENT MID LEVEL TROUGH OVER THE EASTERN U.S EXTENDING SOUTH INTO THE NORTHERN GULF WILL WEAKEN DURING THE SHORT TERM PERIOD AS THE SUBTROPICAL RIDGE FROM THE WESTERN ATLANTIC WEST ACROSS THE SOUTHERN PENINSULA SHIFTS NORTH FRIDAY INTO THE UPCOMING WEEKEND. AS FOR TODAY MODELS DEPICT SLIGHTLY DRIER AIR MOVING INTO WEST CENTRAL AND SOUTHWEST FLORID ASSOCIATED WITH THE RIDGE. THIS DRY AIR SHOULD RESULT IN LOWER STORM COVERAGE WITH POPS IN THE 20 TO 30 PERCENT RANGE FROM THE COAST TO INTERIOR LOCATIONS WHICH IS DEPICTED WELL BY THE MAV AND NAM POP GUIDANCE. THE SURFACE RIDGE AXIS WILL LIFT NORTH TO THE CENTRAL PENINSULA ON FRIDAY. A SLOW INCREASE IN MOISTURE WILL LEAD TO HIGHER COVERAGE OF SCATTERED SHOWERS AND STORMS ALONG THE EAST AND WEST COAST SEA BREEZE BOUNDARIES WITH HIGHEST POPS (40 PERCENT) EXPECTED TO SET UP OVER INLAND LOCATIONS ALONG THE SEA BREEZE MERGER DURING THE AFTERNOON HOURS...WITH 30 PERCENT POPS ALONG THE COAST. DURING FRIDAY NIGHT INTO SATURDAY DEEPER MOISTURE (PW`S INCREASING TOWARD 2 INCHES) WILL OVERSPREAD THE REGION FROM THE SOUTHEAST AHEAD OF A TROPICAL WAVE WHICH IS FORECAST TO MOVE ACROSS THE SOUTH CENTRAL PENINSULA DURING SATURDAY AND SATURDAY NIGHT. THIS MOISTURE WILL LEAD TO EVEN HIGHER CHANCES (POPS 30 TO 50 PERCENT RANGE) FOR SHOWERS AND STORMS ALONG WITH SOME LOCALLY HEAVY RAINFALL AS THE WAVE AFFECTS THE REGION. TEMPERATURES WILL CONTINUE TO RUN A FEW DEGREES ABOVE NORMAL WITH DAYTIME HIGHS CLIMBING INTO THE LOWER AND MID 90S WITH NIGHTTIME LOWS IN THE LOWER 70S NORTH AND MID TO UPPER 70S CENTRAL AND SOUTH. && .AVIATION... SOME SMALL SHOWERS MOVING IN FROM THE GULF COULD BRING BRIEF MVFR CEILINGS AT TPA...PIE AND SRQ THROUGH 14 OR 15Z. MAIN ACTIVITY WILL BE INLAND THIS AFTERNOON WITH LAL THE MOST LIKELY TO SEE IMPACTS. && .MARINE... SURFACE HIGH PRESSURE ACROSS THE SOUTHERN PENINSULA TODAY WILL MAINTAIN A SOUTHWEST TO WEST WIND FLOW AT 10 KNOTS OR LESS ALONG WITH SEAS OF 2 FEET OR LESS. DURING FRIDAY AND INTO THE UPCOMING WEEKEND THE SURFACE RIDGE AXIS WILL SHIFT NORTH TO THE NORTH CENTRAL PENINSULA WITH WINDS BACKING TO THE SOUTHEAST AND EAST...WITH A WEAK PRESSURE PATTERN SUPPORTING AN ENHANCED ONSHORE SEA BREEZE COMPONENT DEVELOPING ALONG THE COAST EACH AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... TPA 92 76 92 78 / 30 20 30 10 FMY 94 76 93 76 / 30 20 30 10 GIF 95 76 95 76 / 30 20 40 20 SRQ 91 76 92 75 / 30 20 30 10 BKV 93 70 93 72 / 30 20 30 10 SPG 91 80 91 79 / 30 20 30 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE...MROCZKA AVIATION...JILLSON PREVIOUS DISCUSSION...MCMICHAEL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1013 PM EDT FRI AUG 3 2012 .UPDATE... SCATTERED TO ISOLATED THUNDERSTORM DEVELOPMENT HAS BEEN PERSISTENT OVER PORTIONS OF CENTRAL AND EASTERN GA WITH LITTLE TO NO ACTIVITY ACROSS THE NW PORTION. THE RECENT HRRR RUNS HAVE BEEN PICKING UP BETTER ON THE CONVECTION AND MAINTAINS THE DEVELOPMENT WELL INTO THE OVERNIGHT. HAVE ADJUSTED TO HAVE CHANCE POPS IN THESE AREAS THROUGH THE OVERNIGHT WHILE DECREASING THE NW AND SE PORTIONS TO SLIGHT CHANCES FROM 06-12Z. ALL ELSE SEEMS TO BE ON TRACK. PREVIOUS DISCUSSION FOLLOWS... 03 && .PREV DISCUSSION... /ISSUED 303 PM EDT FRI AUG 3 2012/ .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... CURRENT RADAR LOOP SHOWS SHOWERS MOVING INTO THE AREA FROM THE NW. ISOLATED THUNDERSTORMS SHOULD START MOVING INTO THE AREA AS SOON AS THINGS DESTABILIZE A BIT MORE THIS AFTERNOON. THE BIGGEST THREAT STILL APPEARS TO BE ISOLATED AREAS OF FLOODING AS PW VALUES ARE IN THE 2 TO 2.20 INCH RANGE THROUGH 00Z SUN. CAPES ARE IN THE 1500 TO 2000 J/KG RANGE WITH LIS NEAR -3 TO -4 THIS AFTERNOON. THE INSTABILITIES DROP OFF VERY QUICKLY AFTER SUNSET BUT THE PWS CONTINUE TO STAY UP. THE SHORTWAVE MOVING SE OUT OF MIDDLE TN WILL PUSH INTO NW GA LATTER TONIGHT AND STALL ACROSS N AND W GA THROUGH 00Z SUN. IT WILL STAY THERE BEFORE BEGINNING TO MAKE ITS WAY BACK NORTHWARD AS THE BERMUDA LIKE RIDGE BEGINS TO BUILD IN FROM THE ATLANTIC SAT/SUN. WILL CONTINUE WITH LIKELY POPS THIS AFTERNOON AND TONIGHT WITH CHANCE POPS SAT/SAT NIGHT. TEMPS WILL STAY NEAR OR SLIGHTLY BELOW SEASONAL NORMS DUE TO THE PRECIP AND CLOUD COVER EXPECTED. 01 && .LONG TERM /SUNDAY THROUGH FRIDAY/... DESPITE SLIGHT TIMING DIFFERENCES...MODELS ARE STILL IN FAIRLY GOOD AGREEMENT WITH A COLD FRONT MOVING INTO NORTH GEORGIA ON MONDAY AND SINKING INTO CENTRAL GEORGIA ON TUESDAY. BASED ON CONSISTENCY OF MODELS WITH AFFECTS FROM FRONT EXPECTED ACROSS THE CWA MONDAY AND TUESDAY...HAVE INCREASED POPS CLOSER TO THE HIGHER END OF CHANCE. DIFFERENCES IN GFS AND ECMWF BECOME MORE APPARENT INTO MIDWEEK. 12Z GFS WANTS TO LINGER THE FRONT ACROSS THE CWA THROUGH THE LONG TERM WHILE THE 00Z ECMWF SLIDES THE BOUNDARY SOUTH OF THE AREA. WITH IT BEING SUMMER HAVE TRENDED TOWARD LOW END CHANCE POPS...CLOSER TO THE GFS SOLUTION. WITH LINGERING BOUNDARY SUGGESTED THOUGH BY THE GFS...POPS MAY BE A LITTLE ON THE LOW SIDE. 11 && .AVIATION... 00Z UPDATE... SCATTERED THUNDERSTORM DEVELOPMENT AND ASSOCIATED OUTFLOW BOUNDARIES WILL CONTINUE TO BRING THE POTENTIAL FOR GUSTY VARIABLE WINDS AND REDUCED VSBYS NEAR KATL AND OTHER SITES THIS EVENING. CIGS WILL GENERALLY STAY VFR THROUGH 06Z TONIGHT THEN LIKELY LOWER TO MVFR OR LOWER AT 1-2 KFT BETWEEN 06Z AND 15Z ALONG WITH SOME BR AND 5-6SM VSBYS. WINDS SHOULD BECOME SSW TO SW STAYING FAIRLY LIGHT OVERNIGHT AND UNDER 10KTS SATURDAY. TSRA IS POSSIBLE AGAIN SATURDAY AFTERNOON SO HAVE INCLUDED PROB30 GROUP FROM 19-23Z. //ATL CONFIDENCE...00Z UPDATE... MEDIUM CONFIDENCE ON TIMING OF CONVECTION AND OVERNIGHT CIGS. HIGH CONFIDENCE ALL ELSE. 03 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 72 89 71 91 / 40 40 30 30 ATLANTA 74 87 72 89 / 30 40 40 30 BLAIRSVILLE 68 83 68 85 / 70 50 30 40 CARTERSVILLE 71 89 70 90 / 60 50 30 40 COLUMBUS 75 91 73 91 / 30 40 40 30 GAINESVILLE 72 87 71 89 / 60 40 30 30 MACON 74 91 72 92 / 30 40 40 30 ROME 72 91 71 91 / 60 50 30 50 PEACHTREE CITY 71 89 70 90 / 30 40 40 30 VIDALIA 73 93 74 93 / 20 30 20 30 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...01/03 LONG TERM....11 AVIATION...03
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
630 AM EDT THU AUG 2 2012 .SYNOPSIS... A WARM HUMID AIRMASS WILL REMAIN ACROSS THE REGION TODAY AND FRIDAY. THERE WILL BE A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL APPROACH SATURDAY AND SUNDAY INCREASING THE CHANCES FOR RAINFALL. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... .THIS MORNING...A SMALL AREA OF SHOWERS WERE AFFECTING THE CSRA. INCLUDED A 30-40 PERCENT CHANCE FOR 3-4 HOURS THIS MORNING. THIS ACTIVITY IS ASSOCIATED WITH A WEAK SHORT WAVE WHICH ACCORDING TO THE RUC13 MODEL SHOULD HAVE MOVED TO THE EAST BY 13Z. ELSEWHERE LESS THAN 10 PERCENT. WILL CONTINUE TO MENTION PATCHY FOG SOUTHEAST PART OF CWA WHERE SURFACE DEWPOINTS ARE A BIT HIGHER. .TODAY...WEAK HIGH PRESSURE REMAINS OVER REGION WITH A WARM HUMID AIRMASS. UPPER TROUGH AXIS IS STILL TO THE EAST AND ANOTHER WEAK IMPULSE IS EXPECTED DROP SOUTHWARD OVER THE AREA LATE THIS AFTERNOON OR EARLY THIS EVENING. NAM BUFR SOUNDING SHOWS A WEAK CAP BUT WITH A LARGE POSITIVE AREA. CAPES AROUND 3000 J/KG WITH MODERATELY STRONG LIS NEAR -6. TOTALS OVER 50 WITH PW VALUES RISING TO OVER 2 INCHES. AFTERNOON TEMPERATURES IN THE UPPER 90S WILL CREATE STRONG LOW LEVEL LAPSE RATES. ALSO...CONVECTIVE TEMPS IN THE LOWER 90S. PREFER A BLEND OF MAV 9 PERCENT AND MET 44 PERCENT. SO WENT 20 PERCENT. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... A FEW LINGERING SHOWERS OR THUNDERSTORMS POSSIBLE. THINK A 20 PERCENT CHANCE WILL COVER IT FOR THIS EVENING. LOWS IN THE 70S. FRIDAY PRETTY MUCH APPEARS TO BE A REPEAT OF THURSDAY. SOME MORE CLOUDS SHOULD KEEP HIGHS FRIDAY 1-2 DEGREES LOWER IN THE MIDDLE 90S. STILL UNSTABLE ENOUGH FRIDAY AFTERNOON FOR ANOTHER 20 PERCENT CHANCE OF SHOWERS OR THUNDERSTORMS DURING THE AFTERNOON AND EVENING. LOWS FRIDAY NIGHT AGAIN IN THE 70S. SATURDAY IS EXPECTED TO BRING AN INCREASE IN THE CHANCES FOR SHOWERS AND THUNDERSTORMS AS A COLD FRONT APPROACHES FROM THE NORTHWEST. WILL INCREASE CHANCES TO 30-40 PERCENT. MORE CLOUDS AND HIGHER RAIN CHANCES SHOULD KEEP HIGHS DOWN A BIT INTO THE LOWER 90S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... MEDIUM RANGE MODELS IN DECENT AGREEMENT WITH UPPER TROUGH POSITION NEAR THE EAST COAST FOR THE PERIOD. SURFACE COLD FRONT EXPECTED TO DROP SOUTHWARD BUT SHOULD MEET CONSIDERABLE RESISTANCE MAKING IT VERY FAR TO THE SOUTH AS PREVIOUS FRONTS HAVE BEEN HELD UP BY THE BERMUDA RIDGE. BUT THE FRONT WILL AT LEAST BE IN THE VICINITY. THIS IS EXPECTED TO GIVE A 20-30 PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS. MOISTURE CONVERGENCE AHEAD OF THE FRONT SHOULD GIVE MORE CLOUDS AND THIS ALONG WITH A BETTER CHANCE OF PRECIP SHOULD HELP TO HOLD HIGH TEMPERATURES BACK TO NORMAL IN THE LOWER 90S. OVERNIGHT LOWS NEAR NORMAL AS WELL IN THE LOWER 70S. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... POTENTIAL FOR MAINLY MVFR VSBYS EARLY THIS MORNING...OTHERWISE VFR CONDITIONS EXPECTED. UPPER SHORT WAVE IS COMING THROUGH THIS MORNING AND WILL PUSH TOWARDS THE COAST THIS AFTERNOON. ISOLATED CONVECTION POSSIBLE THIS MORNING...THEN IT APPEARS THAT MOST CONVECTIVE COVERAGE THIS AFTERNOON WILL BE CONFINED TO THE SE FA AND COASTAL PLAIN. CONFIDENCE/COVERAGE OF TS NOT SUFFICIENT TO INCLUDE IN THE TAFS AT THIS TIME. CONVECTIVE ANALYSIS INDICATES STRONG INSTABILITIES FOR THIS AFTERNOON...SO ANYTHING THAT DOES DEVELOP THIS AFTN/EVE WILL HAVE THE POTENTIAL TO BE STRONG TO SEVERE. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE NIGHT/EARLY MORNING FOG/STRATUS...AS WELL AS SCATTERED AFTERNOON AND EVENING THUNDERSTORMS THROUGH THE PERIOD. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
607 AM EDT THU AUG 2 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THE WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE EVOLUTION OF AFTERNOON CONVECTION WILL MIRROR A TYPICAL MID- LATE SUMMER CONVECTIVE PATTERN TODAY WHERE OUTFLOW BOUNDARIES GENERATED BY ISOLATED SEA BREEZE TSTMS EVENTUALLY INTERSECT OUTFLOWS GENERATED BY UPSTREAM CONVECTION TO SPARK SCATTERED CONVECTIVE CLUSTERS ACROSS INLAND AREAS. THE NAM/S SOLUTION SHOWING SOME SHORT OF MESOSCALE CONVECTIVE SYSTEM /MCS/ PLOWING THROUGH SOUTHEAST GEORGIA LOOKS SOMEWHAT SPURIOUS AND IS NOT SUPPORTED BY ANY OF THE OTHER VARIOUS MESOSCALE OR GLOBAL MODELS ATTM. WILL MAINTAIN A 20-30 PERCENT POPS REGIME WITH THE HIGHEST GRIDDED POPS CENTERED ROUGHLY ALONG AND WEST OF THE I-95 CORRIDOR. HIGHER SHORT-TERM POPS MAY EVENTUALLY BE NEEDED LATER TODAY... ESPECIALLY IF MESOSCALE PROCESSES TAKE HOLD...BUT THIS IS NEARLY IMPOSSIBLE TO PIN DOWN THIS FAR OUT. HIGHS WILL RANGE FROM THE MID 90S INLAND TO THE MID 80S AT THE BEACHES. MODIFIED RAP BUFR SOUNDINGS SHOW DCAPES RISING TO NEAR 1300 J/KG BY EARLY AFTERNOON WITH TOTAL TOTALS NEARING 55 UNITS AND SHOWALTER INDICES DROPPING TO NEAR -3C. THIS COUPLED WITH DELTA EPT/S APPROACHING +30C SUGGEST THERE WILL BE A SLIGHTLY HIGHER RISK FOR DAMAGING WINDS WITH THE STRONGER TSTMS TODAY. THE RISK FOR PULSE SEVERE TSTMS WILL BE HIGHEST NEAR MESOSCALE BOUNDARY INTERACTIONS WITHIN A WEAK 0-6KM BULK SHEAR REGIME. A MENTION FOR ISOLATED SEVERE TSTMS WILL BE PLACED IN THE HAZARDOUS WEATHER OUTLOOK. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... ANY LINGERING CONVECTION WILL DIMINISH BY MID-EVENING AS INSOLATION WANES AND THE SEA BREEZE CLEARS THE WESTERN ZONES. EXPECT A DRY NIGHT TO PREVAIL...ALTHOUGH AN ISOLATED SHOWER/TSTM COULD POPS JUST ABOUT ANYWHERE WITH RESIDUAL OUTFLOWS LIKELY LURKING ABOUT. DEBRIS CLOUDINESS WILL THIN WITH MOSTLY CLEAR SKIES DOMINATING FOR MUCH OF THE OVERNIGHT PERIOD. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO AROUND 80 AT THE BEACHES. THE FORECAST AREA WILL BECOME POSITIONED BETWEEN A SURFACE HIGH PRESSURE TO THE WEST AND A SUBTROPICAL HIGH PRESSURE TO THE EAST. HEIGHTS WILL CONTINUE TO INCREASE THROUGH THE WEEKEND WITH MODEST UPPER LEVEL RIDGING BUILDING ALONG THE EAST COAST. A PERSISTENT SOUTHERLY FLOW WILL ALLOW PLENTY OF DEEP MOISTURE TO CONTINUOUSLY ADVECT OVER THE AREA. MODEL SOUNDINGS VERIFY THIS DEEP MOISTURE WITH PWATS REMAINING STEADY AROUND 2 INCHES THROUGH THE WEEKEND. THUS...EXPECT ISOLATED TO SCATTERED CONVECTION TO DEVELOP FAIRLY EASILY EACH AFTERNOON AS THE SEA BREEZE PROPAGATES INLAND AND CONVECTIVE TEMPERATURES ARE REACHED. WITH HIGH TEMPERATURES EXPECTED TO REACH THE LOW TO MID 90S EACH AFTERNOON...CONVECTIVE TEMPS IN THE UPPER 80S WILL NOT BE DIFFICULT TO EXCEED. STILL...INSTABILITY PARAMETERS ARE LESS THAN IMPRESSIVE WITH SHOWALTER INDICES GENERALLY POSITIVE AND LAPSE RATES BETWEEN 5 AND 6 C/KM. THEREFORE...THE SEVERE POTENTIAL APPEARS LOW...BUT CAN NOT RULE OUT ONE OR TWO ISOLATED STRONG TO SEVERE STORMS. ANY STRONG STORMS WILL LIKELY DEMONSTRATE TRADITIONAL SUMMERTIME PULSE CHARACTERISTICS. ANY LINGERING CONVECTION WILL QUICKLY DIMINISH AFTER SUNSET...WITH OVERNIGHT LOWS EXPECTED TO REMAIN QUITE MILD IN THE MID TO LOW 70S INLAND AND UPPER 70S ALONG THE BEACHES. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... MODELS SHOW SUBTLE HIGH FALLS AT THE BEGINNING OF THE PERIOD AS A LOW PRESSURE SYSTEM MOVES EASTWARD ACROSS THE NEW ENGLAND AREA. ITS ASSOCIATED COLD FRONT WILL LIKELY STALL OUT WELL NORTH OF THE AREA SOMETIME AROUND MID WEEK. MEANWHILE...THE UPPER RIDGE ACROSS CENTRAL UNITED STATES WILL CONTINUE TO STRENGTHEN THROUGH THE PERIOD. AT THE SURFACE...THE FORECAST AREA WILL REMAIN SANDWICHED BETWEEN THE SURFACE HIGH PRESSURE OVER THE MIDDLE OF THE UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. THIS PATTERN COULD ALLOW FOR AN INCREASE IN CONVECTION...ESPECIALLY AS CONVECTION DEVELOPS ALONG THE STALLED FRONT AND INTERACTS WITH OTHER BOUNDARIES...LIKE THE SEA BREEZE. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS WITH LOW TO MID 90S EXPECTED DURING THE AFTERNOON AND DIPPING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... VFR FOR THE NEXT 24 HOURS. LOW PROBABILITIES FOR TSTMS THIS AFTERNOON AT BOTH TERMINALS. EXTENDED AVIATION OUTLOOK...MVFR CIGS/VSBYS POSSIBLE THURSDAY AFTERNOON/EVENING WITH SHOWERS/THUNDERSTORMS. && .MARINE... A BROAD SOUTHERLY FLOW REGIME WILL REMAIN IN TACT ACROSS THE WATERS THROUGH TONIGHT. WINDS WILL REMAIN 10-15 KT WITH SEAS 2-4 FT. ATLANTIC HIGH PRESSURE WILL PREVAIL ACROSS THE MARINE AREA THROUGH EARLY NEXT WEEK. THIS PATTERN WILL CONTINUE TO RESULT IN CONDITIONS BELOW SMALL CRAFT CRITERIA. IN GENERAL...SOUTH/SOUTHWEST WINDS BETWEEN 10 TO 15 KNOTS WILL PERSIST ON THE WESTERN SIDE OF THE ATLANTIC RIDGE WITH BRIEF INCREASES OF 15 TO 20 KNOTS...MAINLY DURING NOCTURNAL SURGING. SEAS WILL ALSO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH THE PERIOD...BUT EXPECT BRIEF INCREASES DURING TIMES OF STRONGER WINDS. GENERALLY...SEAS WILL REMAIN 2 TO 3 FEET WITHIN 20 NM AND NO MORE THAN 5 FEET FURTHER OUT. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE...
AREA FORECAST DISCUSSION...UPDATED
NWS COLUMBIA SC
545 AM EDT THU AUG 2 2012 .SYNOPSIS... A WARM HUMID AIRMASS WILL REMAIN ACROSS THE REGION TODAY AND FRIDAY. THERE WILL BE A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL APPROACH SATURDAY AND SUNDAY INCREASING THE CHANCES FOR RAINFALL. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... .THIS MORNING...A SMALL AREA OF SHOWERS AND THUNDERSTORMS WERE AFFECTING THE CSRA. INCLUDED A 30-40 PERCENT CHANCE FOR 3-4 HOURS` THIS MORNING. THIS ACTIVITY IS ASSOCIATED WITH A WEAK SHORT WAVE WHICH ACCORDING TO THE RUC13 MODEL SHOULD HAVE MOVED TO THE EAST BY 13Z. ELSEWHERE LESS THAN 10 PERCENT. WILL CONTINUE TO MENTION PATCHY FOG SOUTHEAST PART OF CWA WHERE SURFACE DEWPOINTS ARE A BIT HIGHER. .TODAY...WEAK HIGH PRESSURE REMAINS OVER REGION WITH A WARM HUMID AIRMASS. UPPER TROUGH AXIS IS STILL TO THE EAST AND ANOTHER WEAK IMPULSE IS EXPECTED DROP SOUTHWARD OVER THE AREA LATE THIS AFTERNOON OR EARLY THIS EVENING. NAM BUFR SOUNDING SHOWS A WEAK CAP BUT WITH A LARGE POSITIVE AREA. CAPES AROUND 3000 J/KG WITH MODERATELY STRONG LIS NEAR -6. TOTALS OVER 50 WITH PW VALUES RISING TO OVER 2 INCHES. AFTERNOON TEMPERATURES IN THE UPPER 90S WILL CREATE STRONG LOW LEVEL LAPSE RATES. ALSO...CONVECTIVE TEMPS IN THE LOWER 90S. PREFER A BLEND OF MAV 9 PERCENT AND MET 44 PERCENT. SO WENT 20 PERCENT. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... A FEW LINGERING SHOWERS OR THUNDERSTORMS POSSIBLE. THINK A 20 PERCENT CHANCE WILL COVER IT FOR THIS EVENING. LOWS IN THE 70S. FRIDAY PRETTY MUCH APPEARS TO BE A REPEAT OF THURSDAY. SOME MORE CLOUDS SHOULD KEEP HIGHS FRIDAY 1-2 DEGREES LOWER IN THE MIDDLE 90S. STILL UNSTABLE ENOUGH FRIDAY AFTERNOON FOR ANOTHER 20 PERCENT CHANCE OF SHOWERS OR THUNDERSTORMS DURING THE AFTERNOON AND EVENING. LOWS FRIDAY NIGHT AGAIN IN THE 70S. SATURDAY IS EXPECTED TO BRING AN INCREASE IN THE CHANCES FOR SHOWERS AND THUNDERSTORMS AS A COLD FRONT APPROACHES FROM THE NORTHWEST. WILL INCREASE CHANCES TO 30-40 PERCENT. MORE CLOUDS AND HIGHER RAIN CHANCES SHOULD KEEP HIGHS DOWN A BIT INTO THE LOWER 90S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... MEDIUM RANGE MODELS IN DECENT AGREEMENT WITH UPPER TROUGH POSITION NEAR THE EAST COAST FOR THE PERIOD. SURFACE COLD FRONT EXPECTED TO DROP SOUTHWARD BUT SHOULD MEET CONSIDERABLE RESISTANCE MAKING IT VERY FAR TO THE SOUTH AS PREVIOUS FRONTS HAVE BEEN HELD UP BY THE BERMUDA RIDGE. BUT THE FRONT WILL AT LEAST BE IN THE VICINITY. THIS IS EXPECTED TO GIVE A 20-30 PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS. MOISTURE CONVERGENCE AHEAD OF THE FRONT SHOULD GIVE MORE CLOUDS AND THIS ALONG WITH A BETTER CHANCE OF PRECIP SHOULD HELP TO HOLD HIGH TEMPERATURES BACK TO NORMAL IN THE LOWER 90S. OVERNIGHT LOWS NEAR NORMAL AS WELL IN THE LOWER 70S. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... MOSTLY CLEAR SKIES AND LIGHT WINDS AT THE MOMENT. TEMPS AND VSBYS HAVE BEEN SLOW TO FALL SO FAR THIS MORNING. LOW LEVELS NOT AS MOIST AS 24 HOURS AGO...AS DRIER AIR WORKED IN WEDNESDAY. GFS LAMP GUIDANCE HAS BEEN PERFORMING WELL RECENTLY...AND MOST RECENT RUN SUGGESTS NO SIGNIFICANT RESTRICTIONS AT MOST TERMINALS...WITH IFR AT OGB. STRONG UPPER SHORT WAVE IS COMING THROUGH THIS MORNING AND WILL PUSH TOWARDS THE COAST THIS AFTERNOON. ISOLATED CONVECTION POSSIBLE EARLY THIS MORNING. LATEST RADAR INDICATES A FEW SHOWERS AND AN ISOLATED THUNDERSTORM OVER EAST CENTRAL GA MOVING SE TOWARDS THE CSRA. WILL MONITOR FOR POSSIBLE INCLUSION IN THE DNL/AGS TAFS. IT APPEARS THAT MOST CONVECTIVE COVERAGE THIS AFTERNOON WILL BE CONFINED TO THE SE FA AND COASTAL PLAIN. CONFIDENCE/COVERAGE OF TS NOT SUFFICIENT TO INCLUDE IN THE TAFS AT THIS TIME. CONVECTIVE ANALYSIS INDICATES STRONG INSTABILITIES FOR THIS AFTERNOON...SO ANYTHING THAT DOES DEVELOP THIS AFTN/EVE WILL HAVE THE POTENTIAL TO BE STRONG TO SEVERE. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE NIGHT/EARLY MORNING FOG/STRATUS...AS WELL AS SCATTERED AFTERNOON AND EVENING THUNDERSTORMS THROUGH THE PERIOD. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
445 AM EDT THU AUG 2 2012 .SYNOPSIS... A WARM HUMID AIRMASS WILL REMAIN ACROSS THE REGION TODAY AND FRIDAY. THERE WILL BE A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL APPROACH SATURDAY AND SUNDAY INCREASING THE CHANCES FOR RAINFALL. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... .THIS MORNING...SOME WEAKENING SHOWERS AND THUNDERSTORMS MAY AFFECT THE EXTREME NORTHEAST PORTION...LANCASTER AND CHESTERFIELD COUNTIES EARLY BEFORE SUNRISE. THIS ACTIVITY IS ASSOCIATED WITH A WEAK SHORT WAVE WHICH ACCORDING TO THE RUC13 MODEL SHOULD HAVE MOVED TO THE EAST BY 12Z. WILL RUN A 20 PERCENT IN MENTIONED COUNTIES UNTIL 10Z...THEN LESS THAN 10 PERCENT. WILL CONTINUE TO MENTION PATCHY FOG SOUTHEAST PART OF CWA WHERE SURFACE DEWPOINTS ARE A BIT HIGHER. .TODAY...WEAK HIGH PRESSURE REMAINS OVER REGION WITH A WARM HUMID AIRMASS. UPPER TROUGH AXIS IS STILL TO THE EAST AND ANOTHER WEAK IMPULSE IS EXPECTED DROP SOUTHWARD OVER THE AREA LATE THIS AFTERNOON OR EARLY THIS EVENING. NAM BUFR SOUNDING SHOWS A WEAK CAP BUT WITH A LARGE POSITIVE AREA. CAPES AROUND 3000 J/KG WITH MODERATELY STRONG LIS NEAR -6. TOTALS OVER 50 WITH PW VALUES RISING TO OVER 2 INCHES. AFTERNOON TEMPERATURES IN THE UPPER 90S WILL CREATE STRONG LOW LEVEL LAPSE RATES. ALSO...CONVECTIVE TEMPS IN THE LOWER 90S. PREFER A BLEND OF MAV 9 PERCENT AND MET 44 PERCENT. SO WENT 20 PERCENT. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... A FEW LINGERING SHOWERS OR THUNDERSTORMS POSSIBLE. THINK A 20 PERCENT CHANCE WILL COVER IT FOR THIS EVENING. LOWS IN THE 70S. FRIDAY PRETTY MUCH APPEARS TO BE A REPEAT OF THURSDAY. SOME MORE CLOUDS SHOULD KEEP HIGHS FRIDAY 1-2 DEGREES LOWER IN THE MIDDLE 90S. STILL UNSTABLE ENOUGH FRIDAY AFTERNOON FOR ANOTHER 20 PERCENT CHANCE OF SHOWERS OR THUNDERSTORMS DURING THE AFTERNOON AND EVENING. LOWS FRIDAY NIGHT AGAIN IN THE 70S. SATURDAY IS EXPECTED TO BRING AN INCREASE IN THE CHANCES FOR SHOWERS AND THUNDERSTORMS AS A COLD FRONT APPROACHES FROM THE NORTHWEST. WILL INCREASE CHANCES TO 30-40 PERCENT. MORE CLOUDS AND HIGHER RAIN CHANCES SHOULD KEEP HIGHS DOWN A BIT INTO THE LOWER 90S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... MEDIUM RANGE MODELS IN DECENT AGREEMENT WITH UPPER TROUGH POSITION NEAR THE EAST COAST FOR THE PERIOD. SURFACE COLD FRONT EXPECTED TO DROP SOUTHWARD BUT SHOULD MEET CONSIDERABLE RESISTANCE MAKING IT VERY FAR TO THE SOUTH AS PREVIOUS FRONTS HAVE BEEN HELD UP BY THE BERMUDA RIDGE. BUT THE FRONT WILL AT LEAST BE IN THE VICINITY. THIS IS EXPECTED TO GIVE A 20-30 PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS. MOISTURE CONVERGENCE AHEAD OF THE FRONT SHOULD GIVE MORE CLOUDS AND THIS ALONG WITH A BETTER CHANCE OF PRECIP SHOULD HELP TO HOLD HIGH TEMPERATURES BACK TO NORMAL IN THE LOWER 90S. OVERNIGHT LOWS NEAR NORMAL AS WELL IN THE LOWER 70S. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... MOSTLY CLEAR SKIES AND LIGHT WINDS AT THE MOMENT. TEMPS AND VSBYS HAVE BEEN SLOW TO FALL SO FAR THIS MORNING. LOW LEVELS NOT AS MOIST AS 24 HOURS AGO...AS DRIER AIR WORKED IN WEDNESDAY. GFS LAMP GUIDANCE HAS BEEN PERFORMING WELL RECENTLY...AND MOST RECENT RUN SUGGESTS NO SIGNIFICANT RESTRICTIONS AT MOST TERMINALS...WITH IFR AT OGB. STRONG UPPER SHORT WAVE IS COMING THROUGH THIS MORNING AND WILL PUSH TOWARDS THE COAST THIS AFTERNOON. ISOLATED CONVECTION POSSIBLE EARLY THIS MORNING. LATEST RADAR INDICATES A FEW SHOWERS AND AN ISOLATED THUNDERSTORM OVER EAST CENTRAL GA MOVING SE TOWARDS THE CSRA. WILL MONITOR FOR POSSIBLE INCLUSION IN THE DNL/AGS TAFS. IT APPEARS THAT MOST CONVECTIVE COVERAGE THIS AFTERNOON WILL BE CONFINED TO THE SE FA AND COASTAL PLAIN. CONFIDENCE/COVERAGE OF TS NOT SUFFICIENT TO INCLUDE IN THE TAFS AT THIS TIME. CONVECTIVE ANALYSIS INDICATES STRONG INSTABILITIES FOR THIS AFTERNOON...SO ANYTHING THAT DOES DEVELOP THIS AFTN/EVE WILL HAVE THE POTENTIAL TO BE STRONG TO SEVERE. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE NIGHT/EARLY MORNING FOG/STRATUS...AS WELL AS SCATTERED AFTERNOON AND EVENING THUNDERSTORMS THROUGH THE PERIOD. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
323 AM EDT THU AUG 2 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THE WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... THROUGH SUNRISE...EARLY MORNING SURFACE ANALYSIS SHOWED A WEAK SURFACE TROUGH EXTENDING ACROSS CENTRAL GEORGIA INTO THE NORTHERN MIDLANDS. THE LATEST RUNS OF THE RAP AND NSSL WRF MODELS SHOW ISOLATED CONVECTION FIRING ALONG THE TROUGH OVER THE NEXT FEW HOURS AS SHORTWAVE ENERGY MOVING THROUGH EASTERN KENTUCKY MOVES CLOSER. ALREADY SEEING A FEW CLUSTERS OF TSTMS FIRING ACROSS THE NORTH CAROLINA FOOTHILLS...SO IT IS CERTAINLY CONCEIVABLE THAT A TSTMS OR TWO COULD POP ACROSS THE MIDLANDS AND DRIFT INTO THE WESTERN ZONES PRIOR TO SUNRISE. ATTM IT APPEARS THE CHANCES FOR MEASURABLE RAINFALL WILL REMAIN LESS THAN 20 PERCENT SO WILL KEEP MENTIONABLE POPS OUT OF FORECAST FOR NOW AND MONITOR TRENDS CAREFULLY. MORNING LOWS FROM THE LOWER 70S WELL INLAND TO AROUND 80 AT THE BEACHES LOOK ON TRACK. TODAY...THE EVOLUTION OF AFTERNOON CONVECTION WILL MIRROR A TYPICAL MID-LATE SUMMER CONVECTIVE PATTERN TODAY WHERE OUTFLOW BOUNDARIES GENERATED BY ISOLATED SEA BREEZE TSTMS EVENTUALLY INTERSECT OUTFLOWS GENERATED BY UPSTREAM CONVECTION TO SPARK SCATTERED CONVECTIVE CLUSTERS ACROSS INLAND AREAS. THE NAM/S SOLUTION SHOWING SOME SHORT OF MESOSCALE CONVECTIVE SYSTEM /MCS/ PLOWING THROUGH SOUTHEAST GEORGIA LOOKS SOMEWHAT SPURIOUS AND IS NOT SUPPORTED BY ANY OF THE OTHER VARIOUS MESOSCALE OR GLOBAL MODELS ATTM. WILL MAINTAIN A 20-30 PERCENT POPS REGIME WITH THE HIGHEST GRIDDED POPS CENTERED ROUGHLY ALONG AND WEST OF THE I-95 CORRIDOR. HIGHER SHORT-TERM POPS MAY EVENTUALLY BE NEEDED LATER TODAY...ESPECIALLY IF MESOSCALE PROCESSES TAKE HOLD...BUT THIS IS NEARLY IMPOSSIBLE TO PIN DOWN THIS FAR OUT. HIGHS WILL RANGE FROM THE MID 90S INLAND TO THE MID 80S AT THE BEACHES. MODIFIED RAP BUFR SOUNDINGS SHOW DCAPES RISING TO NEAR 1300 J/KG BY EARLY AFTERNOON WITH TOTAL TOTALS NEARING 55 UNITS AND SHOWALTER INDICES DROPPING TO NEAR -3C. THIS COUPLED WITH DELTA EPT/S APPROACHING +30C SUGGEST THERE WILL BE A SLIGHTLY HIGHER RISK FOR DAMAGING WINDS WITH THE STRONGER TSTMS TODAY. THE RISK FOR PULSE SEVERE TSTMS WILL BE HIGHEST NEAR MESOSCALE BOUNDARY INTERACTIONS WITHIN A WEAK 0-6KM BULK SHEAR REGIME. A MENTION FOR ISOLATED SEVERE TSTMS WILL BE PLACED IN THE HAZARDOUS WEATHER OUTLOOK. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/... ANY LINGERING CONVECTION WILL DIMINISH BY MID-EVENING AS INSOLATION WANES AND THE SEA BREEZE CLEARS THE WESTERN ZONES. EXPECT A DRY NIGHT TO PREVAIL...ALTHOUGH AN ISOLATED SHOWER/TSTM COULD POPS JUST ABOUT ANYWHERE WITH RESIDUAL OUTFLOWS LIKELY LURKING ABOUT. DEBRIS CLOUDINESS WILL THIN WITH MOSTLY CLEAR SKIES DOMINATING FOR MUCH OF THE OVERNIGHT PERIOD. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO AROUND 80 AT THE BEACHES. THE FORECAST AREA WILL BECOME POSITIONED BETWEEN A SURFACE HIGH PRESSURE TO THE WEST AND A SUBTROPICAL HIGH PRESSURE TO THE EAST. HEIGHTS WILL CONTINUE TO INCREASE THROUGH THE WEEKEND WITH MODEST UPPER LEVEL RIDGING BUILDING ALONG THE EAST COAST. A PERSISTENT SOUTHERLY FLOW WILL ALLOW PLENTY OF DEEP MOISTURE TO CONTINUOUSLY ADVECT OVER THE AREA. MODEL SOUNDINGS VERIFY THIS DEEP MOISTURE WITH PWATS REMAINING STEADY AROUND 2 INCHES THROUGH THE WEEKEND. THUS...EXPECT ISOLATED TO SCATTERED CONVECTION TO DEVELOP FAIRLY EASILY EACH AFTERNOON AS THE SEA BREEZE PROPAGATES INLAND AND CONVECTIVE TEMPERATURES ARE REACHED. WITH HIGH TEMPERATURES EXPECTED TO REACH THE LOW TO MID 90S EACH AFTERNOON...CONVECTIVE TEMPS IN THE UPPER 80S WILL NOT BE DIFFICULT TO EXCEED. STILL...INSTABILITY PARAMETERS ARE LESS THAN IMPRESSIVE WITH SHOWALTER INDICES GENERALLY POSITIVE AND LAPSE RATES BETWEEN 5 AND 6 C/KM. THEREFORE...THE SEVERE POTENTIAL APPEARS LOW...BUT CAN NOT RULE OUT ONE OR TWO ISOLATED STRONG TO SEVERE STORMS. ANY STRONG STORMS WILL LIKELY DEMONSTRATE TRADITIONAL SUMMERTIME PULSE CHARACTERISTICS. ANY LINGERING CONVECTION WILL QUICKLY DIMINISH AFTER SUNSET...WITH OVERNIGHT LOWS EXPECTED TO REMAIN QUITE MILD IN THE MID TO LOW 70S INLAND AND UPPER 70S ALONG THE BEACHES. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... MODELS SHOW SUBTLE HIGH FALLS AT THE BEGINNING OF THE PERIOD AS A LOW PRESSURE SYSTEM MOVES EASTWARD ACROSS THE NEW ENGLAND AREA. ITS ASSOCIATED COLD FRONT WILL LIKELY STALL OUT WELL NORTH OF THE AREA SOMETIME AROUND MID WEEK. MEANWHILE...THE UPPER RIDGE ACROSS CENTRAL UNITED STATES WILL CONTINUE TO STRENGTHEN THROUGH THE PERIOD. AT THE SURFACE...THE FORECAST AREA WILL REMAIN SANDWICHED BETWEEN THE SURFACE HIGH PRESSURE OVER THE MIDDLE OF THE UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. THIS PATTERN COULD ALLOW FOR AN INCREASE IN CONVECTION...ESPECIALLY AS CONVECTION DEVELOPS ALONG THE STALLED FRONT AND INTERACTS WITH OTHER BOUNDARIES...LIKE THE SEA BREEZE. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS WITH LOW TO MID 90S EXPECTED DURING THE AFTERNOON AND DIPPING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... VFR FOR THE NEXT 24 HOURS. COULD SEE SOME GROUND FOG DEVELOP AT EITHER KCHS/KSAV GIVEN MOIST LOW-LEVEL PROFILES UNDER A LIGHT WIND REGIME. ANY REDUCTIONS WILL GENERALLY BE CONFINED TO AN HOUR OR TWO PRIOR TO SUNRISE. LOW PROBABILITIES FOR TSTMS THIS AFTERNOON AT BOTH TERMINALS. CHANCES TO LOW TO JUSTIFY ANY MENTION THIS FAR OUT. EXTENDED AVIATION OUTLOOK...MVFR CIGS/VSBYS POSSIBLE THURSDAY AFTERNOON/EVENING WITH SHOWERS/THUNDERSTORMS. && .MARINE... A BROAD SOUTHERLY FLOW REGIME WILL REMAIN IN TACT ACROSS THE WATERS THROUGH TONIGHT. WINDS WILL REMAIN 10-15 KT WITH SEAS 2-4 FT. ATLANTIC HIGH PRESSURE WILL PREVAIL ACROSS THE MARINE AREA THROUGH EARLY NEXT WEEK. THIS PATTERN WILL CONTINUE TO RESULT IN CONDITIONS BELOW SMALL CRAFT CRITERIA. IN GENERAL...SOUTH/SOUTHWEST WINDS BETWEEN 10 TO 15 KNOTS WILL PERSIST ON THE WESTERN SIDE OF THE ATLANTIC RIDGE WITH BRIEF INCREASES OF 15 TO 20 KNOTS...MAINLY DURING NOCTURNAL SURGING. SEAS WILL ALSO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH THE PERIOD...BUT EXPECT BRIEF INCREASES DURING TIMES OF STRONGER WINDS. GENERALLY...SEAS WILL REMAIN 2 TO 3 FEET WITHIN 20 NM AND NO MORE THAN 5 FEET FURTHER OUT. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
204 AM EDT THU AUG 2 2012 .PREV DISCUSSION... UPDATE... /ISSUED 956 PM EDT WED AUG 1 2012/ ISOLATED STRONG TO SEVERE STORM POTENTIAL CONTINUES ACROSS THE NORTHERN TIER OF THE FORECAST AREA EARLY TONIGHT. SPC ALSO UPDATED TO INCLUDE PART OF THIS AREA IN A SLIGHT RISK...HOWEVER THE MAJORITY OF THE MORE INTENSE DEVELOPMENT HAS PASSED. SEVERAL CLUSTERS OF CONVECTION NEAR A SFC BOUNDARY HAVE BEEN TRACKING SEWD FROM SOUTHERN TN AND THE HRRR HAS THIS DEVELOPMENT PERSISTING FARTHER SOUTH UNTIL JUST NORTH OF ATLANTA BY NEAR 06Z. PER OBSERVED DEWPOINT DEPRESSIONS AHEAD OF THE STORMS AND RECENT SOUNDING DATA...THE LOW LEVELS ARE QUITE DRY AND STORM DEVELOPMENT IS LIKELY ELEVATED. LARGE HAIL AND DAMAGING WINDS HAVE BEEN THE MAIN CONCERNS...HOWEVER SOME CELLS HAVE SHOWN ROTATION ALBEIT ONLY OBSERVABLE ABOUT 6KFT AGL. ADJUSTED POPS TO LIKELY AND CHANCE IN THE NORTH BEFORE MIDNIGHT AND THEN SLIGHT TO NO CHANCE THE REST OF THE OVERNIGHT. MADE OTHER ADJUSTMENTS TO TEMP AND DEWPOINT TRENDS...BUT DID NOT AFFECT OVERNIGHT MINS. PREVIOUS DISCUSSION FOLLOWS... 03 PREV DISCUSSION... SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... /ISSUED 252 PM EDT WED AUG 1 2012/ CURRENT SATELLITE LOOP SHOW MOSTLY CLEAR SKIES OVER THE AREA. THERE IS SOME CU BEGINNING TO DEVELOP ACROSS WEST AND CENTRAL GA SO THIS LOOKS LIKE IT COULD BE THE BEGINNING OF SOME ISOLATED SHRA/TSRA THIS AFTERNOON/EVENING. THERE IS A WEAK STATIONARY BOUNDARY OVER N GA THAT MAY ACT AS A FOCUSING MECHANISM FOR THUNDERSTORM DEVELOPMENT. THE KEY IS GOING TO BE JUST HOW MUCH DRIER AIR HAS FILTER INTO THE AREA UNDER THE WEAK RIDGE BUILDING IN FROM THE NORTH AND HOW STRONG IS THE INSTABILITY ACROSS THE AREA. LOOKS LIKE WE WILL SEE SOME ISOLATED TO SCATTERED SHRA/TSRA DEVELOP ACROSS NORTH GA BUT IT SHOULD DISSIPATE OUT SHORTLY AFTER SUNSET. MOISTURE INCREASES SOME THURSDAY FROM THE NORTH AS THE RIDGE BREAKS DOWN A BIT MORE THROUGH THE END OF THE WEEK. TEMPS WILL STAY NEAR SEASONAL NORMS THROUGH THE SHORT TERM. 01 LONG TERM /FRIDAY THROUGH WEDNESDAY/... /ISSUED 252 PM EDT WED AUG 1 2012/ UPPER LEVEL HIGH PRESSURE RIDGE REMAINS SITUATED OVER TEXAS INTO THE EXTENDED PERIOD...WITH NORTHWEST FLOW PREVAILING ACROSS THE TENNESSEE VALLEY AND INTO GEORGIA. THIS FLOW WILL CONTINUE TO USHER UPPER LEVEL DISTURBANCES INTO THE REGION INTO THE WEEKEND. THESE FEATURES...COMBINED WITH AMPLE DAYTIME HEATING WILL KEEP SLIGHT CHANCE TO CHANCE THUNDERSTORMS ACROSS THE AREA. INTO EARLY NEXT WEEK...HIGH PRESSURE RIDGE OVER THE ATLANTIC BECOMES MORE DOMINANT ACROSS THE SOUTHEAST AS LOW PRESSURE DEEPENS OVER SOUTH CENTRAL CANADA. THIS LOW WILL DRAG A FRONTAL BOUNDARY THROUGH THE TENNESSEE VALLEY BY MONDAY MORNING...AND PUSH INTO NORTHWEST GEORGIA BY MONDAY AFTERNOON. TIMING OF THIS SYSTEM AS IT PUSHES THROUGH DIFFERS SLIGHTLY BY MODEL...SO HAVE MADE NO MAJOR ADJUSTMENTS TO THE CURRENT FORECAST BASED ON THE UNCERTAINTY. HIGH PRESSURE BUILDS BACK INTO THE REGION BEHIND THE FRONT...AND ANTICIPATE DIURNALLY DRIVEN CONVECTION TO RETURN BY MID WEEK. PREVIOUS FORECAST CONTINUES TO APPEAR ON TRACK...AND HAVE ADDED THE PREVIOUS DISCUSSION BELOW... 31 /ISSUED 438 AM EDT WED AUG 1 2012/ LITTLE CHANGE IN THE PATTERN...HENCE THE SCATTERED AFTERNOON AND EVENING THUNDERSTORMS TO CONTINUE. UPPER LEVEL LOW REMAINS OVER TEXAS AS STORM SYSTEM RIDE OVER THE TOP THROUGH THE PLAINS AND OHIO VALLEY. THE HIGH OFF THE COAST CONTINUES TO HOLD A WARM MOIST AIR MASS OVER THE SOUTHEAST... THOUGH THE GFS MAINTAINS A HIGHER MEAN RH OVER THE AREA THAN DOES THE ECMWF. THE GFS SOLUTION PREFERRED. SUNDAY NIGHT INTO MONDAY THEY BOTH HAVE A COLD FRONT MOVING THROUGH EASTERN TENNESSEE AND INTO NORTHERN GEORGIA MONDAY MORNING. IT SETTLES INTO CENTRAL/SOUTH GEORGIA AND WEAKENS BY TUESDAY...BUT PLENTY OF MOISTURE REMAINS OVER THE AREA TO CONTINUE THE AFTERNOON AND EVENING THUNDERSTORMS. LIKEWISE...SEE NO CHANGE IN THE TEMPERATURES THROUGH THE PERIOD. 37 && .AVIATION... 06Z UPDATE... VFR THROUGH THE PERIOD...EXCEPT FOR MVFR MORNING HAZE/FOG POSSIBLE AT SOME SITES. SOUTHWESTERLY WINDS STRUGGLING TO REACH 10 KTS...WITH LIGHT VARIABILITY AT NIGHT FOR MOST SITES. CONVECTION MENTIONABLE IN THE AFTERNOON AT ALL SITES. //ATL CONFIDENCE...06Z UPDATE... MEDIUM CONFIDENCE FOR CONVECTION THURSDAY... HIGH CONFIDENCE ON ALL OTHER ELEMENTS. PREFERRED GFS SLIGHTLY OVER THE NAM. RAG && .PRELIMINARY POINT TEMPS/POPS... ATHENS 94 73 94 71 / 40 20 20 30 ATLANTA 95 75 91 73 / 30 20 30 30 BLAIRSVILLE 88 67 85 67 / 20 20 30 50 CARTERSVILLE 96 72 92 70 / 30 20 30 40 COLUMBUS 97 76 93 73 / 30 20 20 20 GAINESVILLE 93 75 92 71 / 40 20 30 40 MACON 97 73 93 71 / 30 20 20 20 ROME 96 72 94 71 / 20 20 40 40 PEACHTREE CITY 94 71 90 69 / 30 20 20 20 VIDALIA 97 76 95 73 / 30 20 20 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RAG LONG TERM....37 AVIATION...RAG
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
516 PM CDT THU AUG 2 2012 .DISCUSSION... 308 PM CDT THE MAIN CONCERNS DURING THE FORECAST PERIOD ARE CONVECTIVE CHANCES AND TIMING...ESPECIALLY ON SATURDAY AFTERNOON AND NIGHT...ALONG WITH THE WARM TEMPERATURES FRIDAY AND SATURDAY. A WEAK AND ILL DEFINED COOL FRONTAL BOUNDARY HAS DROPPED ACROSS SOUTHERN WISCONSIN THIS AFTERNOON. THE CONVECTIVE THREAT ACROSS FAR NORTHERN ILLINOIS LATE THIS AFTERNOON CONTINUES TO LOOK VERY LOW. THE CLOUD COVER SHOWN ON REGIONAL SATELLITE IMAGERY ACROSS NORTHERN ILLINOIS DOES NOT HAVE MUCH OF A CONVECTIVE LOOK TO IT. IN ADDITION...AN AMDAR SOUNDING OUT OF MDW INDICATES THAT INSTABILITY IS VERY WEAK. SO IT APPEARS THE AREA WILL LIKELY REMAIN DRY. TONIGHT INTO FRIDAY...THE MODEL GUIDANCE IS INDICATING THAT SEVERAL MID LEVEL SHORT WAVE PERTURBATIONS WILL BE EJECTED EASTWARD ACROSS THE LOWER MISSOURI AND MID MISSISSIPPI VALLEYS WITHIN THE STRONG WESTERLIES ACROSS THE PLAINS AND UPPER MIDWEST. THE STRONGEST OF THESE DISTURBANCES...CURRENTLY ACROSS KANSAS AND NORTHWESTERN MISSOURI...WILL MOVE EAST SOUTHEASTWARD ACROSS DOWNSTATE ILLINOIS AND ACROSS THE SOUTHERN APPELLATIONS TONIGHT INTO FRIDAY. THIS WILL LIKELY FOCUS MOST OF THE CONVECTION SOUTH OF THE AREA DURING THIS PERIOD. HOWEVER...IT APPEARS THAT A SURFACE WARM FRONT/TROUGH...ASSOCIATED WITH A WEAK SURFACE WAVE ACROSS THE PLAINS...WILL BE IN PLACE ACROSS NORTHERN ILLINOIS ON FRIDAY. MODEL BUFFER SOUNDINGS ACROSS THE REGION ON FRIDAY DO INDICATE AN INCREASE IN INSTABILITY AS BETTER BOUNDARY LAYER MOISTURE GETS TRANSPORTED NORTHWARD. OVERALL THIS DOES NOT LOOKS LIKE A GOOD SETUP FOR WIDESPREAD CONVECTION AS MOST OF THE LARGER SCALE SUPPORT WILL BE WELL TO THE SOUTH OF THE AREA. HOWEVER...I CANT RULE OUT SOME ISOLATED STORMS DEVELOPING ACROSS PORTIONS OF THE AREA DURING THE AFTERNOON...ESPECIALLY WITH A LOW LEVEL BOUNDARY/CONVERGENCE ZONE IN PLACE. MOST MODEL GUIDANCE KEEPS THE AREA DRY...BUT SOME OF THE CONVECTIVE ALLOWING MODELS DO ALLOW SOME ISOLATED ACTIVITY TO DEVELOP ACROSS PORTIONS OF THE AREA. WITH THIS IN MIND...I WILL CONTINUE TO MENTION THE SLIGHT CHANCE POPS FOR FRIDAY INTO FRIDAY NIGHT...MAINLY SOUTH OF INTERSTATE 80. FINALLY LATER SATURDAY AND SATURDAY NIGHT THE STRONG SHORT WAVE TROUGH IS EXPECTED TO MOVE ACROSS THE DAKOTAS EASTWARD ACROSS THE UPPER GREAT LAKES. AT THE SURFACE...A POTENT AREA OF LOW PRESSURE WILL LIKELY DRIVE A COLD FRONT ACROSS NORTHERN ILLINOIS SOMETIME SATURDAY EVENING AND ACROSS NORTHWESTERN INDIANA OVERNIGHT. THERE CONTINUES TO BE SOME UNCERTAINTY WITH THE TIMING OF THIS SYSTEM AS THE GFS ENSEMBLES STILL SHOW SOME DECENT SPREAD. IN SPITE OF THESE TIMING DIFFERENCES...THIS STILL PROMISES TO PRODUCE BY FAR THE BEST POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA DURING THE FORECAST PERIOD. IT CURRENTLY APPEARS THE BEST CHANCES FOR THUNDERSTORMS WILL BE SATURDAY NIGHT. THERE IS ALSO A POTENTIAL FOR A SEVERE THREAT AS WELL SATURDAY NIGHT. HOWEVER...THERE REMAINS QUESTIONS AS TO WHETHER OR NOT THE STRONGER MID LEVEL FLOW WILL COINCIDE WITH THE UNSTABLE AIRMASS...OR IF IT WILL LAG BEHIND THE FRONT. TEMPERATURES FRIDAY AND SATURDAY WILL CONTINUE TO BE IN THE 90S. I AM CONCERNED THAT WE WILL BE FLIRTING WITH HEAT ADVISORY CRITERIA ACROSS MUCH OF THE AREA ON SATURDAY. MOISTURE SHOULD INCREASE SUBSTANTIALLY ON SATURDAY AHEAD OF THE APPROACHING COLD FRONT. SURFACE DEW POINTS LOOK TO CLIMB INTO THE LOW 70S DURING THE DAY. THIS COMBINED WITH TEMPERATURES IN THE MID TO PERHAPS UPPER 90S IN A FEW AREAS...LOOKS TO PRODUCE HEAT INDICES AROUND 105 DEGREES. MUCH COOLER AND DRIER WEATHER MOVES ACROSS THE AREA FOR SUNDAY INTO NEXT WEEK. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * WIND DIRECTIONS INTO FRIDAY MORNING. TRS //DISCUSSION...UPDATED 22Z... LAKE BREEZE HAS CONTINUED TO PUSH WELL INLAND TO WRN MCHENRY...NW KANE W CNTRL DUPAGE COUNTIES DURING THE MID-LATE AFTERNOON BUT MORE SLOWLY ACROSS SE DUPAGE AND SRN COOK INTO NRN LAKE COUNTY AS 950HPA VAD WINDS AT KLOT AND TMDW SHOWING ESE AROUND 10KT WHILE TMDW AND TMKE SHOWING E TO ENE 10-15KT. 20Z AND 21Z RUC13 RUNS DEPICTING VERY SHORT TERM WINDS WELL MAINTAINING E-ENE 10-15 KT SFC WINDS AT ORD SO HAVE FOLLOWED THIS OUTPUT. TRS PREVIOUS 18Z DISCUSSION... WIND DIRECTIONS WILL REMAIN PROBLEMATIC INTO FRIDAY MORNING DUE TO A FAIRLY WEAK GRADIENT AND POTENTIAL FOR A LAKE BREEZE THIS AFTERNOON. WEAK HIGH PRESSURE WILL MOVE EAST ACROSS THE OHIO VALLEY THIS AFTERNOON AS WEAK LOW PRESSURE OVER NORTHERN MISSOURI SLOWLY DRIFTS EAST/NORTHEAST TONIGHT INTO FRIDAY MORNING. IN BETWEEN THESE TWO FEATURES...THE WINDS HAVE BECOME LIGHT AND VRB AND EVEN CALM ACROSS THE AREA. LOW LEVEL WINDS ALSO ARE FAIRLY LIGHT AND EXPECT A LAKE BREEZE TO DEVELOP. WHETHER ITS THE LAKE BREEZE ITSELF OR A COMBINATION WITH THE GRADIENT...EXPECT WINDS TO TURN SOUTHEASTERLY EARLY THIS AFTERNOON AND MORE EAST/SOUTHEAST BY MID/LATE AFTERNOON. HAVE KEPT LAKE BREEZE TIMING UNCHANGED BUT WILL NEED TO MONITOR THROUGH THE EARLY AFTERNOON. GRADIENT REMAINS LIGHT OVERNIGHT AND EXPECT PERIODS OF LIGHT AND VARIABLE WINDS THOUGH ANY PREVAILING WINDS LIKELY TO BE EAST/SOUTHEASTERLY... ESPECIALLY TOWARD MORNING. GRADIENT TIGHTENS UP ENOUGH FOR MAINLY EASTERLY WINDS UP TO 10KTS ON FRIDAY...POSSIBLY TURNING A BIT MORE NORTHEASTERLY IN THE AFTERNOON. GUIDANCE CONTINUES TO HINT AT SOME LIGHT FOG/HAZE FRIDAY MORNING. GIVEN THE RELATIVELY DRY GROUND CERTAINLY NOT EXPECTING ANYTHING TOO LOW OR WIDESPREAD BUT GIVEN THE LIGHT WINDS IF TEMPS CAN FALL OFF TO THE DEWPOINTS...COMBINED WITH THE LIGHT WINDS...THERE COULD BE SOME PATCHY/GROUND FOG. WITH THE WEAK LOW EXPECTED TO PASS SOUTH OF THE TERMINALS ON FRIDAY...EXPECT ANY PRECIP/CONVECTION TO ALSO REMAIN SOUTH OF THE TERMINALS BUT SOME ISOLATED ACTIVITY IN THE AFTERNOON IS POSSIBLE BUT CONFIDENCE AND EXPECTED COVERAGE TOO LOW TO INCLUDE IN THIS FORECAST. CMS //ORD AND MDW CONFIDENCE...UPDATED 22Z... * HIGH CONFIDENCE IN WIND TRENDS THROUGH EARLY EVENING. * HIGH CONFIDENCE IN OTHER FORECAST ELEMENTS WITH NO SIG WX TO OCCUR. TRS //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... FRIDAY NIGHT...VFR. SATURDAY...VFR. SLGT CHANCE TSRA/SHRA INCREASING TO CHANCE IN THE AFTERNOON. PERIODS MVFR/IFR PSBL. SUNDAY THROUGH WEDNESDAY...VFR. JEE && .MARINE... 243 PM CDT AN AREA OF LOW PRESSURE CENTERED ACROSS FAR SOUTHWEST QUEBEC CONTINUES TO WEAKEN AND DRIFT NORTHEAST...WITH A TRAILING FRONTAL BOUNDARY STRETCHING WEST/SOUTHWEST THROUGH NORTHERN MICHIGAN INTO NORTHERN WISCONSIN. THIS BOUNDARY IS EXPECTED TO DRIFT SOUTH ACROSS LAKE MICHIGAN THIS EVENING...WITH WINDS TURNING NORTH/NORTHEAST ACROSS NORTHERN LAKE MICHIGAN. MEANWHILE AN AREA OF HIGH PRESSURE OVER WESTERN ONTARIO WILL CONTINUE TO PUSH EAST ACROSS ONTARIO...AS THE FRONTAL BOUNDARY OVER LAKE MICHIGAN SLOWLY ERODES. ANOTHER AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS THE WESTERN DAKOTAS FRIDAY NIGHT...THEN STRENGTHEN AS THIS LOW PRESSURE SLIDES EAST ACROSS THE UPPER MIDWEST AND LAKE SUPERIOR SATURDAY AFTERNOON. THE PRESSURE GRADIENT IS EXPECTED TO TIGHTEN ALONG THIS AREA OF LOW PRESSURE SAT NIGHT FOR CENTRAL/NORTHERN LAKE MICHIGAN AND COULD BE TIGHT ENOUGH TO CREATE OCCASIONAL GALE FORCE GUSTS SUNDAY. THEN THE FRONTAL BOUNDARY PUSHES EAST OF LAKE MICHIGAN SUNDAY AND BROAD HIGH PRESSURE THEN BUILDS IN FOR EARLY NEXT WEEK...WITH SEVERAL PERIODS OF LIGHT FLOW FROM THE NORTH TO NORTHEAST. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
642 PM CDT FRI AUG 3 2012 .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... FOCUS THROUGHOUT THE SHORT/MID RANGE WILL BE ON SYSTEM MOVING THROUGH THE REGION TONIGHT THROUGH SATURDAY NIGHT...AND ASSOCIATED COLD FRONT DROPPING THROUGH THE STATE. INITIALLY LINGERING ACTIVITY FROM EARLIER TODAY TO THE NORTHWEST HAS JUST DIMINISHED IN THE PAST FEW HOURS ACROSS NORTHWEST IOWA ASSOCIATED WITH SOME WEAK ENERGY ALOFT PUSHING OUT AHEAD OF THE MAIN WAVE. HRRR ADVERTISES SOME REDEVELOPMENT ACROSS THE NORTH CENTRAL CWA WITH THIS ENERGY...AND HAVE A FEW WEAK CELLS POPPING JUST TO THE NE OF THE CWA. ALSO HAVE DECENT CU FIELD EXTENDING BACK INTO THE CWA...WITH ANOTHER CU FIELD SITUATED ACROSS THE EXTREME SOUTHERN CWA NORTH OF ONGOING MCS THAT HAS BEEN IN PLACE ACROSS MO ALL DAY. THEREFORE HAVE SOME SLIGHT CHANCE POPS IN THE NORTH AND SOUTH THROUGH THE REMAINDER OF THE AFTERNOON HOURS WITH SPC MESODATA SUGGESTING SUFFICIENT INSTABILITY IN PLACE AND DECENT SHEAR ACROSS THE NORTH. THEREFORE AN ISOLATED SEVERE STORM CANNOT BE RULED EITHER ACROSS THE NORTH WITH ANY ACTIVITY THAT MAY DEVELOP. OTHERWISE GREATER CHANCE FOR PRECIPITATION/CONVECTION LATER TONIGHT AS STORMS CONTINUE TO DEVELOP IN VICINITY OF THE SFC FRONT SITUATED ACROSS CENTRAL SD INTO CENTRAL NE. AS THE MAIN UPPER WAVE PUSHES EAST ACROSS THE DAKOTAS AND INTO MINNESOTA SATURDAY...ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE STATE...WITH SHOWERS AND THUNDERSTORMS EXPECTED TO BE ONGOING ACROSS THE NORTHWESTERN CWA SATURDAY MORNING AND CONTINUING TO TRACK EASTWARD SLOWLY DIMINISHING WITH TIME. FRONT WILL THEN PUSH INTO THE EASTERN CWA IN THE AFTERNOON HOURS...WITH REDEVELOPMENT EXPECTED BY LATE AFTERNOON ALONG THE FRONT...WITH THE FRONT EXITING THE CWA BY EARLY TO LATE EVENING AS THE UPPER SYSTEM TRACKS INTO THE GREAT LAKES REGION. THEREFORE HAVE GREATEST POPS FOR SATURDAY ACROSS THE CWA...WITH BEST CHANCE OF WIDER SPREAD PRECIPITATION AS THE AREA HAS SEEN IN A FEW WEEKS. MUCH COOLER AIR MOVING IN BEHIND THE FRONT...WITH H85 TEMPS DROPPING INTO THE LOWER TEENS TO MID TEENS CELSIUS ALOFT. THEREFORE MAX TEMPS TO BE COOLER IN AREAS BEHIND THE FRONT SATURDAY...WITH MANY SITES NOT MAKING IT OUT OF THE 70S ACROSS NORTHWESTERN IOWA AND MUCH COOLER CONDITIONS ACROSS THE ENTIRE STATE FOR SUNDAY. HIGHS SUNDAY EXPECTED TO TOP OUT IN THE 70S NORTH TO MID 80S SOUTH...WITH A QUICK CHANGE TO RETURN FLOW MONDAY AND MID 80S TO 90S WITH DRY CONDITIONS SUNDAY INTO MONDAY. ANOTHER WEAK SHORTWAVE DROPS DOWN THROUGH THE REGION MONDAY NIGHT IN NORTHWEST FLOW PATTERN ALOFT. THEREFORE COULD SEE A CHANCE FOR SOME NOCTURNAL THUNDERSTORMS MONDAY NIGHT ACROSS MUCH OF THE CWA. .LONG TERM /TUESDAY THROUGH FRIDAY/... BOTH GFS AND EURO NOW INDICATE BROAD NORTHWEST FLOW INTO NEXT WEEK AS UPPER RIDGING RETROGRADES INTO THE ROCKIES. THIS SHOULD DO A COUPLE OF THIS FOR IOWA...FIRST TEMPERATURES WILL LIKELY REMAIN COOLER DURING THE NEXT WEEK THAN WHAT PREVIOUS FORECASTS HAD GOING. READINGS ARE EXPECTED TO BE CLOSE TO NORMAL OR SLIGHTLY ABOVE BUT NOT THE 10 TO 15 DEGREE DEPARTURES WE SAW DURING MUCH OF JULY. SECOND...THE THREAT OF PRECIPITATION SHOULD BE GREATER AS WEAK SHORTWAVES IN THE FLOW DROP INTO THE MIDWEST. THE MAIN PROBLEM WITH THESE IS MORE OF A TIMING ISSUE AS IS OFTEN TYPICAL IN NORTHWEST FLOW. THESE CONDITIONS WILL CERTAINLY PROVIDE SOME RELIEF FROM THE INTENSIFYING DROUGHT WITH BOTH MODELS INDICATING THE NORTHWEST FLOW CONTINUING BEYOND THE FORECAST PERIOD. && .AVIATION...04/00Z CDFNT FROM ERN ND INTO THE SWRN NEBRASKA PNHDL WILL MOVE INTO IA TONIGHT AND PASS SOUTHEAST OF THE TAF SITES BY MID AFTERNOON SAT. STRONG LINE OF TSRA ALONG THE FRONT THIS EVENING WILL MOVE INTO NWRN IA BY 08Z...BECOMING MORE SCATTERED AS THEY APPROACH THE NWRN TAF SITES TOWARD 09Z. A FEW SHOWERS MAY REACH KDSM AFT SUNRISE. ADDITIONAL TSRA DEVELOPMENT LIKE BY EARLY TO MID AFTERNOON OVER THE EASTERN TAF SITES NEAR AND JUST BEHIND CDFNT. STRATO CU DECK IS POSSIBLE OVER THE NWRN HALF OF THE STATE FOR SAT AFTERNOON. AT THIS TIME AM NOT SURE IT ILL BE AS LOW AS MVFR AND HELD IT ABOVE 030. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...MJB LONG TERM...COGIL AVIATION...MS AUG 12
AREA FORECAST DISCUSSION
NWS WICHITA KS
1240 PM CDT THU AUG 2 2012 .AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU WEAK PV ANOMALY WILL CONTINUE MOVING SLOWLY EASTWARD ACROSS SOUTH CENTRAL/SOUTHEAST KS THIS AFTERNOON. THIS SHOULD ALLOW FOR ISOLATED-WIDELY SCATTERED HIGH-BASED -SHRA/-TSRA TO PERSIST THIS AFTERNOON. WILL MENTION VCSH AT HUT/ICT/SLN BASED ON LATEST RADAR TRENDS. THERE WILL BE A SMALL CHANCE OF HIGH-BASED -TSRA TONIGHT INTO FRIDAY MORNING ACROSS THE AREA...WITH HIGH PRECIPITABLE WATER AXIS REMAINING ALONG WITH WEAKNESS AT 700 MB. CHANCES APPEAR TOO LOW TO MENTION AT TAF SITES THIS FAR OUT ESPECIALLY GIVEN COVERAGE CONCERNS. GUSTY WINDS POSSIBLE NEAR ANY STORM ACTIVITY GIVEN TEMPERATURE-DEWPOINT SPREADS. OTHERWISE VFR TO PREVAIL. JMC && .PREV DISCUSSION... /ISSUED 800 AM CDT THU AUG 2 2012/ UPDATE... WITH THE -SHRA & -TSRA HAVING VACATED CNTRL & SE KS HAVE UPDATED ALL AFFECTED PRODUCTS TO REMOVE THE MORNING MENTION OF THIS ACTIVITY. PREV DISCUSSION... /ISSUED 653 AM CDT THU AUG 2 2012/ AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU FOCUS THROUGH ~15Z IS ON OUTFLOW-INDUCED N/NE WINDS RANGING FROM 10 TO 20 KTS SUSTAINED WITH GUSTS TO ~30 KTS IN THE IMMEDIATE WAKE OF THE BOUNDARY. QUIET WEATHER ANTICIPATED FOR REST OF THE DAY WITH A PREDOMINANTLY E/NE WIND <=10KTS IN MOST AREAS. WITH THE SFC FRONT LURKING ABOUT THE PREMISES A FEW TSRA REMAIN POSSIBLE THIS EVENING & ESPECIALLY LATE TONIGHT OVER CNTRL KS. THIS WILL DRAW INCREASED ATTENTION WITH 00Z & 06Z TAF ISSUANCES. PREV DISCUSSION... /ISSUED 333 AM CDT THU AUG 2 2012/ DISCUSSION... TODAY-TONIGHT: ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400. CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH IT. FRI-FRI NIGHT: HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW... COULD BE EVEN WARMER THAN FORECAST. SAT-SUN: GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD. LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT... WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN SECTIONS. MON-WED: CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH. INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED. WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD. -HOWERTON AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU. DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 107 78 104 78 / 20 20 10 10 HUTCHINSON 103 76 103 76 / 20 20 10 10 NEWTON 103 77 102 77 / 20 20 10 10 ELDORADO 104 77 104 77 / 20 20 10 10 WINFIELD-KWLD 111 80 106 80 / 20 20 10 10 RUSSELL 98 73 101 73 / 20 30 10 20 GREAT BEND 100 74 102 74 / 20 20 10 20 SALINA 98 76 102 75 / 20 30 10 20 MCPHERSON 101 75 103 75 / 20 30 10 20 COFFEYVILLE 110 79 106 79 / 20 20 10 10 CHANUTE 105 76 103 78 / 20 20 10 10 IOLA 103 77 102 77 / 20 20 10 10 PARSONS-KPPF 107 77 104 79 / 20 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING UNTIL 9 PM CDT THIS EVENING FOR KSZ069- 082-083-091>096-098>100. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1221 PM CDT THU AUG 2 2012 ...UPDATE TO AVIATION... .DISCUSSION... ANOTHER MCS ROLLING ACROSS THE AREA THIS MORNING. THERE HAVE BEEN WIDESPREAD WIND REPORTS OF 35 TO 50 MPH WITH THESE STORMS...WHICH HAVE LAID DOWN AN IMPRESSIVE OUTFLOW BOUNDARY MOVING TO THE SOUTH. THE LATEST HRRR HI RESOLUTION MODEL SHOWS THESE SHOWERS AND STORMS LINGERING THROUGH THE MORNING HOURS ACROSS NORTHEAST KS. THEREFORE EXPECT A SIMILAR AFFECT TO THE WEATHER THAT WAS SEEN YESTERDAY. NAMELY SLIGHTLY COOLER WEATHER ACROSS NORTHERN COUNTIES DUE TO CLOUD COVER AND THE INITIALLY COOL OUTFLOW. THINK THE AIRMASS WILL RECOVER ENOUGH TO REACH THE MID AND UPPER 90S ACROSS NORTHERN COUNTIES WITH AROUND 100 IN EAST CENTRAL KS. SINCE HIGHS SHOULD BE SLIGHTLY COOLER...THERE IS UNCERTAINTY IN HEAT INDICES GETTING WARM ENOUGH FOR A HEAT ADVISORY...AND WILL OPT TO LET THE DAY SHIFT MONITOR HOW THE AIRMASS RECOVERS AND SEE IF HIGHS WILL GET HOT ENOUGH TO WARRANT AN ADVISORY. FOR TONIGHT THE MODELS SHOW WARM AIR ADVECTION AND ISENTROPIC LIFT REDEVELOPING ACROSS CENTRAL KS AS POTENTIAL IMPULSES ROUND THE RIDGE AND MOVE OFF THE HIGHER TERRAIN. THEREFORE HAVE SOME LOW CHANCE POPS. CONFIDENCE IN LOCATION OF THE PRECIP IS MARGINAL...SO DO NOT FEEL COMFORTABLE WITH HIGHER POPS AT THIS TIME. THERE IS THE POTENTIAL FOR ANY NOCTURNAL CONVECTION TO AGAIN LINGER INTO THE MORNING HOURS FRIDAY...AND THIS IS REFLECTED IN THE FORECAST. MODELS ARE IN GOOD AGREEMENT WITH THE FRONT MOVING INTO THE AREA SATURDAY. THE NAM AND GFS ARE SHOWING BETTER PVA AND FRONTOGENESIS WITH THE BOUNDARY THAN EARLIER MODELS. HOWEVER THE NAM STILL APPEARS TO BE SKITTISH WITH QPF. THINK WITH THE FRONT PROVIDING LIFT IN AN UNCAPPED AIRMASS THAT THERE WILL BE AT LEAST A CHANCE FOR SCATTERED CONVECTION...LASTING INTO SATURDAY NIGHT. THE FRONT WILL BRING A RELATIVELY NICE COOL DOWN FOR THE AREA BY SUNDAY. FOR SUNDAY THROUGH WEDNESDAY...HAVE NOT SPENT MUCH TIME LOOKING AT THIS PERIOD DUE TO THE ONGOING CONVECTION. HOWEVER WITH THE PATTERN INITIALLY AMPLIFYING EXPECT THE EARLY PART OF THE WEEK TO BE DRY ON THE BACK SIDE OF THE DEPARTING SHORTWAVE. THERE IS INCREASING UNCERTAINTY BY THE MIDDLE OF THE WEEK AS MODELS HAVE VARYING TIMING OF ANOTHER FRONT MOVING INTO THE AREA. LEFT THE FORECAST DRY FOR NOW UNTIL THERE IS BETTER CLUSTERING IN THE MODEL SOLUTIONS. WOLTERS && .AVIATION... STILL OUTSIDE CHANCE FOR A SHOWER OR STORM AT ONE OF THE TERMINALS THIS AFTERNOON THEN AGAIN OVERNIGHT...HOWEVER MOST GUIDANCE SUGGEST STORMS TO STAY SOUTH. WITH BOUNDARY TO THE SOUTH HAVE NE WINDS BLO 12KTS AND VFR CIGS...WILL WATCH FOR BR OVERNIGHT BUT THINK RAIN AMOUNTS WERE LOW ENOUGH TO NEGATE THAT THREAT. 67 && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
800 AM CDT THU AUG 2 2012 .UPDATE... WITH THE -SHRA & -TSRA HAVING VACATED CNTRL & SE KS HAVE UPDATED ALL AFFECTED PRODUCTS TO REMOVE THE MORNING MENTION OF THIS ACTIVITY. && .PREV DISCUSSION... /ISSUED 653 AM CDT THU AUG 2 2012/ AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU FOCUS THROUGH ~15Z IS ON OUTFLOW-INDUCED N/NE WINDS RANGING FROM 10 TO 20 KTS SUSTAINED WITH GUSTS TO ~30 KTS IN THE IMMEDIATE WAKE OF THE BOUNDARY. QUIET WEATHER ANTICIPATED FOR REST OF THE DAY WITH A PREDOMINANTLY E/NE WIND <=10KTS IN MOST AREAS. WITH THE SFC FRONT LURKING ABOUT THE PREMISES A FEW TSRA REMAIN POSSIBLE THIS EVENING & ESPECIALLY LATE TONIGHT OVER CNTRL KS. THIS WILL DRAW INCREASED ATTENTION WITH 00Z & 06Z TAF ISSUANCES. PREV DISCUSSION... /ISSUED 333 AM CDT THU AUG 2 2012/ DISCUSSION... TODAY-TONIGHT: ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400. CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH IT. FRI-FRI NIGHT: HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW... COULD BE EVEN WARMER THAN FORECAST. SAT-SUN: GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD. LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT... WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN SECTIONS. MON-WED: CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH. INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED. WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD. -HOWERTON AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU. DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 107 78 104 78 / 20 20 10 10 HUTCHINSON 104 76 103 76 / 20 20 10 10 NEWTON 103 77 102 77 / 20 20 10 10 ELDORADO 104 77 104 77 / 20 20 10 10 WINFIELD-KWLD 111 80 106 80 / 20 20 10 10 RUSSELL 99 73 101 73 / 20 30 10 20 GREAT BEND 101 74 102 74 / 20 20 10 20 SALINA 99 76 102 75 / 20 30 10 20 MCPHERSON 102 75 103 75 / 20 30 10 20 COFFEYVILLE 110 79 106 79 / 20 20 10 10 CHANUTE 105 76 103 78 / 20 20 10 10 IOLA 103 77 102 77 / 20 20 10 10 PARSONS-KPPF 107 77 104 79 / 20 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING FROM NOON TODAY TO 9 PM CDT THIS EVENING FOR KSZ069-082-083-091>094-098>100. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
654 AM CDT THU AUG 2 2012 ...UPDATE TO AVIATION... .DISCUSSION... ANOTHER MCS ROLLING ACROSS THE AREA THIS MORNING. THERE HAVE BEEN WIDESPREAD WIND REPORTS OF 35 TO 50 MPH WITH THESE STORMS...WHICH HAVE LAID DOWN AN IMPRESSIVE OUTFLOW BOUNDARY MOVING TO THE SOUTH. THE LATEST HRRR HI RESOLUTION MODEL SHOWS THESE SHOWERS AND STORMS LINGERING THROUGH THE MORNING HOURS ACROSS NORTHEAST KS. THEREFORE EXPECT A SIMILAR AFFECT TO THE WEATHER THAT WAS SEEN YESTERDAY. NAMELY SLIGHTLY COOLER WEATHER ACROSS NORTHERN COUNTIES DUE TO CLOUD COVER AND THE INITIALLY COOL OUTFLOW. THINK THE AIRMASS WILL RECOVER ENOUGH TO REACH THE MID AND UPPER 90S ACROSS NORTHERN COUNTIES WITH AROUND 100 IN EAST CENTRAL KS. SINCE HIGHS SHOULD BE SLIGHTLY COOLER...THERE IS UNCERTAINTY IN HEAT INDICES GETTING WARM ENOUGH FOR A HEAT ADVISORY...AND WILL OPT TO LET THE DAY SHIFT MONITOR HOW THE AIRMASS RECOVERS AND SEE IF HIGHS WILL GET HOT ENOUGH TO WARRANT AN ADVISORY. FOR TONIGHT THE MODELS SHOW WARM AIR ADVECTION AND ISENTROPIC LIFT REDEVELOPING ACROSS CENTRAL KS AS POTENTIAL IMPULSES ROUND THE RIDGE AND MOVE OFF THE HIGHER TERRAIN. THEREFORE HAVE SOME LOW CHANCE POPS. CONFIDENCE IN LOCATION OF THE PRECIP IS MARGINAL...SO DO NOT FEEL COMFORTABLE WITH HIGHER POPS AT THIS TIME. THERE IS THE POTENTIAL FOR ANY NOCTURNAL CONVECTION TO AGAIN LINGER INTO THE MORNING HOURS FRIDAY...AND THIS IS REFLECTED IN THE FORECAST. MODELS ARE IN GOOD AGREEMENT WITH THE FRONT MOVING INTO THE AREA SATURDAY. THE NAM AND GFS ARE SHOWING BETTER PVA AND FRONTOGENESIS WITH THE BOUNDARY THAN EARLIER MODELS. HOWEVER THE NAM STILL APPEARS TO BE SKITTISH WITH QPF. THINK WITH THE FRONT PROVIDING LIFT IN AN UNCAPPED AIRMASS THAT THERE WILL BE AT LEAST A CHANCE FOR SCATTERED CONVECTION...LASTING INTO SATURDAY NIGHT. THE FRONT WILL BRING A RELATIVELY NICE COOL DOWN FOR THE AREA BY SUNDAY. FOR SUNDAY THROUGH WEDNESDAY...HAVE NOT SPENT MUCH TIME LOOKING AT THIS PERIOD DUE TO THE ONGOING CONVECTION. HOWEVER WITH THE PATTERN INITIALLY AMPLIFYING EXPECT THE EARLY PART OF THE WEEK TO BE DRY ON THE BACK SIDE OF THE DEPARTING SHORTWAVE. THERE IS INCREASING UNCERTAINTY BY THE MIDDLE OF THE WEEK AS MODELS HAVE VARYING TIMING OF ANOTHER FRONT MOVING INTO THE AREA. LEFT THE FORECAST DRY FOR NOW UNTIL THERE IS BETTER CLUSTERING IN THE MODEL SOLUTIONS. WOLTERS && .AVIATION... LINGERING CONVECTION ON THE SOUTH SIDE OF MCV OVER THE NORTHERN CWA WILL KEEP BKN AREA OF CONVECTION IN THE KTOP/KFOE SITES THROUGH 13Z...THEN GRADUALLY ENDING....ALTHOUGH GUSTY NORTH WINDS WILL PERSIST UNTIL 14Z-16Z TIME FRAME. MAIN AREA OF CONVECTION SHOULD BE EAST OF THE KMHK SITE BY 12Z BUT SHOWERS LINGERING THROUGH 13Z BEFORE ENDING. MVFR/BRIEF IFR VSBYS POSSIBLE IN ANY THUNDERSTORMS UNTIL 13Z...BUT CIGS SHOULD GENERALLY BE VFR. FOLLOWING CONVECTION THIS MORNING...REMAINDER OF THE TAFS WILL BE VFR AND DRY...ALTHOUGH MORE CONVECTION CANNOT BE RULED OUT AFTER 06Z TONIGHT...BUT CONFIDENCE IS TOO LOW TO INCLUDE IN THE TAFS AT THIS POINT. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
653 AM CDT THU AUG 2 2012 .AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU FOCUS THROUGH ~15Z IS ON OUTFLOW-INDUCED N/NE WINDS RANGING FROM 10 TO 20 KTS SUSTAINED WITH GUSTS TO ~30 KTS IN THE IMMEDIATE WAKE OF THE BOUNDARY. QUIET WEATHER ANTICIPATED FOR REST OF THE DAY WITH A PREDOMINANTLY E/NE WIND <=10KTS IN MOST AREAS. WITH THE SFC FRONT LURKING ABOUT THE PREMISES A FEW TSRA REMAIN POSSIBLE THIS EVENING & ESPECIALLY LATE TONIGHT OVER CNTRL KS. THIS WILL DRAW INCREASED ATTENTION WITH 00Z & 06Z TAF ISSUANCES. && .PREV DISCUSSION... /ISSUED 333 AM CDT THU AUG 2 2012/ DISCUSSION... TODAY-TONIGHT: ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400. CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH IT. FRI-FRI NIGHT: HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW... COULD BE EVEN WARMER THAN FORECAST. SAT-SUN: GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD. LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT... WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN SECTIONS. MON-WED: CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH. INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED. WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD. -HOWERTON AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU. DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 107 78 104 78 / 20 20 10 10 HUTCHINSON 104 76 103 76 / 20 20 10 10 NEWTON 103 77 102 77 / 20 20 10 10 ELDORADO 104 77 104 77 / 20 20 10 10 WINFIELD-KWLD 111 80 106 80 / 20 20 10 10 RUSSELL 99 73 101 73 / 20 30 10 20 GREAT BEND 101 74 102 74 / 20 20 10 20 SALINA 99 76 102 75 / 20 30 10 20 MCPHERSON 102 75 103 75 / 20 30 10 20 COFFEYVILLE 110 79 106 79 / 20 20 10 10 CHANUTE 105 76 103 78 / 20 20 10 10 IOLA 103 77 102 77 / 20 20 10 10 PARSONS-KPPF 107 77 104 79 / 20 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING FROM NOON TODAY TO 9 PM CDT THIS EVENING FOR KSZ069-082-083-091>094-098>100. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
343 AM CDT THU AUG 2 2012 .DISCUSSION... ANOTHER MCS ROLLING ACROSS THE AREA THIS MORNING. THERE HAVE BEEN WIDESPREAD WIND REPORTS OF 35 TO 50 MPH WITH THESE STORMS...WHICH HAVE LAID DOWN AN IMPRESSIVE OUTFLOW BOUNDARY MOVING TO THE SOUTH. THE LATEST HRRR HI RESOLUTION MODEL SHOWS THESE SHOWERS AND STORMS LINGERING THROUGH THE MORNING HOURS ACROSS NORTHEAST KS. THEREFORE EXPECT A SIMILAR AFFECT TO THE WEATHER THAT WAS SEEN YESTERDAY. NAMELY SLIGHTLY COOLER WEATHER ACROSS NORTHERN COUNTIES DUE TO CLOUD COVER AND THE INITIALLY COOL OUTFLOW. THINK THE AIRMASS WILL RECOVER ENOUGH TO REACH THE MID AND UPPER 90S ACROSS NORTHERN COUNTIES WITH AROUND 100 IN EAST CENTRAL KS. SINCE HIGHS SHOULD BE SLIGHTLY COOLER...THERE IS UNCERTAINTY IN HEAT INDICES GETTING WARM ENOUGH FOR A HEAT ADVISORY...AND WILL OPT TO LET THE DAY SHIFT MONITOR HOW THE AIRMASS RECOVERS AND SEE IF HIGHS WILL GET HOT ENOUGH TO WARRANT AN ADVISORY. FOR TONIGHT THE MODELS SHOW WARM AIR ADVECTION AND ISENTROPIC LIFT REDEVELOPING ACROSS CENTRAL KS AS POTENTIAL IMPULSES ROUND THE RIDGE AND MOVE OFF THE HIGHER TERRAIN. THEREFORE HAVE SOME LOW CHANCE POPS. CONFIDENCE IN LOCATION OF THE PRECIP IS MARGINAL...SO DO NOT FEEL COMFORTABLE WITH HIGHER POPS AT THIS TIME. THERE IS THE POTENTIAL FOR ANY NOCTURNAL CONVECTION TO AGAIN LINGER INTO THE MORNING HOURS FRIDAY...AND THIS IS REFLECTED IN THE FORECAST. MODELS ARE IN GOOD AGREEMENT WITH THE FRONT MOVING INTO THE AREA SATURDAY. THE NAM AND GFS ARE SHOWING BETTER PVA AND FRONTOGENESIS WITH THE BOUNDARY THAN EARLIER MODELS. HOWEVER THE NAM STILL APPEARS TO BE SKITTISH WITH QPF. THINK WITH THE FRONT PROVIDING LIFT IN AN UNCAPPED AIRMASS THAT THERE WILL BE AT LEAST A CHANCE FOR SCATTERED CONVECTION...LASTING INTO SATURDAY NIGHT. THE FRONT WILL BRING A RELATIVELY NICE COOL DOWN FOR THE AREA BY SUNDAY. FOR SUNDAY THROUGH WEDNESDAY...HAVE NOT SPENT MUCH TIME LOOKING AT THIS PERIOD DUE TO THE ONGOING CONVECTION. HOWEVER WITH THE PATTERN INITIALLY AMPLIFYING EXPECT THE EARLY PART OF THE WEEK TO BE DRY ON THE BACK SIDE OF THE DEPARTING SHORTWAVE. THERE IS INCREASING UNCERTAINTY BY THE MIDDLE OF THE WEEK AS MODELS HAVE VARYING TIMING OF ANOTHER FRONT MOVING INTO THE AREA. LEFT THE FORECAST DRY FOR NOW UNTIL THERE IS BETTER CLUSTERING IN THE MODEL SOLUTIONS. WOLTERS && .AVIATION... MAIN CONCERN FOR THE TAFS WILL BE THE TIMING AND AREAL COVERAGE OF CONVECTION AS IT MOVES ACROSS NORTHEAST KANSAS. CIGS EXPECTED TO BE VFR THROUGH THE PERIOD BUT MVFR VSBYS ARE POSSIBLE WITH TSRA. CONVECTION SHOULD MOVE EAST OF THE TERMINALS BY 16Z. HAVE MAINTAINED A MENTION OF VCTS ATTM. 53 && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
333 AM CDT THU AUG 2 2012 .DISCUSSION... TODAY-TONIGHT: ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400. CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH IT. FRI-FRI NIGHT: HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW... COULD BE EVEN WARMER THAN FORECAST. SAT-SUN: GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD. LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT... WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN SECTIONS. MON-WED: CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH. INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED. WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD. -HOWERTON && .AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU. DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 107 78 104 78 / 20 20 10 10 HUTCHINSON 104 76 103 76 / 20 20 10 10 NEWTON 103 77 102 77 / 20 20 10 10 ELDORADO 104 77 104 77 / 20 20 10 10 WINFIELD-KWLD 111 80 106 80 / 20 20 10 10 RUSSELL 99 73 101 73 / 20 30 10 20 GREAT BEND 101 74 102 74 / 20 20 10 20 SALINA 99 76 102 75 / 20 30 10 20 MCPHERSON 102 75 103 75 / 20 30 10 20 COFFEYVILLE 110 79 106 79 / 20 20 10 10 CHANUTE 105 76 103 78 / 20 20 10 10 IOLA 103 77 102 77 / 20 20 10 10 PARSONS-KPPF 107 77 104 79 / 20 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING FROM NOON TODAY TO 9 PM CDT THIS EVENING FOR KSZ069-082-083-091>094-098>100. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1155 PM MDT WED AUG 1 2012 .UPDATE... ISSUED AT 808 PM MDT WED AUG 1 2012 MODIFIED THE EVENING AND OVERNIGHT FORECAST SLIGHTLY MAINLY TO ACCOUNT FOR CURRENT CLOUD COVER AND PRECIPITATION COVERAGE AND TO BLEND INTO OVERNIGHT TRENDS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 225 PM MDT WED AUG 1 2012 THROUGH TONIGHT...CONVECTION IS ONCE AGAIN EXPECTED TO DEVELOP ACROSS THE PALMER DIVIDE REGION OF COLORADO WITH A GRADUAL SHIFT EASTWARD WITH TIME. HRRR IS ALSO DEVELOPING CONVECTION ACROSS NORTHWEST KANSAS BUT GIVEN LACK OF CU DEVELOPMENT OVER THIS AREA...CONFIDENCE IS BELOW AVERAGE IN THIS SOLUTION. HAVING SAID THAT...WILL MAINTAIN SLIGHT CHANCE POPS TO COVER THIS POTENTIAL. DID BUMP POPS UP SLIGHTLY FOR THE LATE EVENING TIME FRAME WHEN CONFIDENCE IS HIGHEST. TRENDED OVERNIGHT LOWS UP OVER THE EAST SIMILAR TO WHAT WAS OBSERVED THIS MORNING. OTHERWISE...LIGHT AND VARIABLE WINDS WITH A GRADUALLY CLEARING SKY ARE EXPECTED. THURSDAY...MAX TEMPS WILL BE SLIGHTLY COOLER AS COMPARED WITH TODAY WITH HIGHS IN MOST LOCATIONS REMAINING IN THE MID 90S TO AROUND 100 DEGREES. POTENTIAL EXISTS ONCE AGAIN FOR CONVECTION DEVELOPING DURING THE LATE AFTERNOON HOURS. GIVEN OBSERVED PWAT VALUES AROUND 135 PERCENT OF NORMAL...LOCALLY HEAVY RAINFALL WILL ONCE AGAIN BE A THREAT. GUSTY OUTFLOW WINDS ALSO APPEAR TO BE POSSIBLE BASED ON POINT SOUNDINGS FROM ACROSS THE AREA. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 225 PM MDT WED AUG 1 2012 THURSDAY NIGHT-SATURDAY...FAIRLY ACTIVE WEATHER WILL CONTINUE THROUGH THE PERIOD AS STRONG SHORT WAVE TROUGH DIVES INTO THE NORTHERN PLAINS...FORCING STRONG COLD FRONT INTO THE TRI STATE AREA FRIDAY NIGHT AND SATURDAY...BRINGING SOME RELIEF FROM THE HEAT TO THE AREA BY SATURDAY AFTERNOON. NOT REAL CONFIDENT IN PRECIPITATION CHANCES ON THURSDAY EVENING WITH MAIN STATIONARY FRONT WELL TO THE SOUTH OF THE AREA AND LOW LEVEL FLOW BEING LIGHT AND GENERALLY WESTERLY. HOWEVER...PERIOD OF LARGE SCALE ASCENT WILL MOVE JUST NORTH OF THE CWA AND IF THE MUCH WEAKER CINH PROFILE OF THE NAM VERIFIES...THAT MAY BE ENOUGH TO INITIATE AT LEAST A FEW STORMS ALONG SFC TROUGH THAT EXTENDS INTO WESTERN CWA. GIVEN ABOVE CONCERNS AND SREF DATA REALLY FOCUSING BEST CHANCES NEAR FRONT DO NOT THINK OVERALL PATTERN REALLY WARRANTS MORE THAN 15-20 PERCENT. THINK BEST CHANCES FOR PRECIPITATION WILL BE DURING THE OVERNIGHT HOURS ON FRIDAY AS STRONG COLD FRONT SWEEPS ACROSS THE AREA...WHICH WILL NOT ONLY BRING A PERIOD OF STRONG NEAR SFC ASCENT BUT A PERIOD OF DEEPER ASCENT DEEP DIRECT CIRCULATION EXPECTED TO DEVELOP BEHIND FRONT COLOCATED WITH AREA OF LARGE SCALE ASCENT AS PER Q VECTOR ANALYSIS. WHILE FORCING WILL LIKELY BE THE STRONGEST ITS BEEN OUT OF THE PAST SEVERAL DAYS...STILL A LARGE AMOUNT OF UNCERTAINTY WITH RESPECT TO HOW MUCH INSTABILITY WILL BE AHEAD AND BEHIND FRONTAL ZONE AS EVIDENCED BY LARGE DIFFERENCES BETWEEN GEFS AND SREF PROBABILISTIC OUTPUT...AND THINK FOR THE TIME BEING THINK KEEPING POPS BELOW 50 PERCENT WARRANTED ATTM. IN THE EXTENDED (SAT NIGHT-WEDNESDAY)...WHILE 06Z ROUND OF ENSEMBLES SHOWED LITTLE SPREAD IN OVERALL PATTERN STARTING TO SEE A BIT MORE UNCERTAINTY DEVELOP WITH RESPECT TO STRENGTH OF H5 RIDGE EXPECTED TO DEVELOP OVER THE ROCKIES THROUGH THE MIDDLE OF NEXT WEEK. SOME ENSEMBLES SEEM TO BE CLUSTERING TOWARDS BOTH THE MORE AMPLIFIED GFS WITH THE OTHERS MORE IN THE ECMWF CAMP WHICH CERTAINLY LOWERS CONFIDENCE IN TRYING TO PICK ONE MODEL OVER THE OTHER. FOR THE TIME BEING...THINK CONSENSUS APPROACH THE BEST BET FOR HIGH TEMPS FOR THE TIME BEING. TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD...BUT WITH POSSIBILITY OF CWA BEING ON NORTHEAST SIDE OF A FAIRLY AMPLIFIED RIDGE POTENTIAL FOR COOLER AIR BACKING INTO THE AREA KEEPS CONFIDENCE TOO LOW TO MAKE LARGE DEVIATIONS FOR MAX TEMPS. FOR LOWS...WITH SFC HIGH SETTLING OVER THE AREA ON SAT NIGHT BEHIND STRONG COLD FRONT AND AT LEAST A FEW HOURS OF LIGHT WINDS AND MUCH DRIER AIR COULD SEE FAIRLY CHILLY LOWS ACROSS MUCH OF THE CWA WITH VALUES IN THE MID TO UPPER 50S. PRECIP CHANCES DO NOT LOOK PARTICULARLY GREAT THROUGH THE PERIOD BOTH DUE TO MORE STABLE AIR MOVING IN BEHIND THE FRONT AND THEN WITH STRONG RIDGE DEVELOPING NEAR THE AREA. LEFT A FEW AREAS SMALL CHANCES...ESPECIALLY ON SAT DUE TO FRONTAL TIMING CONCERNS AND AGAIN ON WEDNESDAY AS GEFS DATA BRINGING FAIRLY HIGH PROBABILITIES OF MEASURABLE PRECIP OVERNIGHT TUES INTO WED MORNING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1144 PM MDT WED AUG 1 2012 SCATTERED THUNDERSTORMS ARE MOVING EAST...DECREASING IN COVERAGE...AND BECOMING ISOLATED RAIN SHOWERS ACROSS THE CENTRAL HIGH PLAINS REGION. THISE ISOLATED SHOWERS WILL BE DIMINISHING BY ABOUT 08Z. VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD AT BOTH KMCK AND KGLD WITH ANOTHER ROUND OF ISOLATED SHOWERS ACROSS THE REGION AFTER ABOUT 22Z THURSDAY AFTERNOON AND EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...LOCKHART SHORT TERM...FOLTZ LONG TERM...JRM AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS WICHITA KS
1155 PM CDT WED AUG 1 2012 .AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU. DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT FOR NOW. && ARL .PREV DISCUSSION... /ISSUED 928 PM CDT WED AUG 1 2012/ UPDATE... TRIMMED BACK POPS FOR CENTRAL KANSAS A LITTLE BEFORE 06Z AS THE ACTIVITY HAS BARELY ENTERED EXTREME NORTHWEST KANSAS AT THIS HOUR. AREAL COVERAGE OF POPS THOUGH LOOKS GOOD FROM 9Z ON SO LEFT THAT AS IS. GUSTY DOWNBURST WINDS ARE STILL POSSIBLE WITH STORMS THAT DO MAKE IT INTO THE AREA AS DCAPE VALUES EXTEND AS HIGH AT 2000 J/KG. ARL PREV DISCUSSION... /ISSUED 643 PM CDT WED AUG 1 2012/ AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU NOT MUCH CHANGE TO PREVIOUS FORECAST AS VFR CONDITIONS SHOULD DOMINATE MOST OF THE PERIOD FOR ALL SITES DUE TO 500MB RIDGE CENTERED OVER THE SOUTHERN HIGH PLAINS. MOISTURE FLOWING NORTHWARD AROUND THE WESTERN PERIPHERY OF THIS RIDGE IS CAUSING DIURNAL CONVECTION TO FORM OVER THE HIGH PLAINS AND BEGINNING TO SLOWLY DRIFT EAST/SOUTHEAST. WITH ELEVATED INSTABILITY IN NORTH CENTRAL KANSAS OVERNIGHT THE BEST SHOT AT SHOWERS STILL APPEARS TO BE AT RSL AND SLN AROUND 6 TO 12Z. WASN`T CONFIDENT ENOUGH TO ENTER VCTS AT HUT...ICT OR CNU...BUT WILL HAVE TO REEVALUATE FOR THE 12Z CYCLE. OVERNIGHT MCS COULD PROPAGATE AROUND TO THE SOUTHEAST ALONG A 850MB BAROCLINIC ZONE TOWARDS CNU BY 12Z...BUT DECIDED TO LEAVE THE VCTS OUT FOR THE MOMENT. WIND FORECAST IS ALSO TRICKY DUE TO POSSIBLE OUTFLOW FROM THE MCS AND THE SURFACE TROUGH THAT NOSES INTO SOUTH CENTRAL KANSAS...BUT THE GENERAL THEME IS THAT WINDS SHOULD MOSTLY BE OUT OF THE SOUTHEAST. LAUGEMAN PREV DISCUSSION... /ISSUED 325 PM CDT WED AUG 1 2012/ DISCUSSION... MESO HIGH FROM LAST NIGHTS/THIS MORNINGS CONVECTION HAS RESULTED IN A MUCH COOLER DAY THAN PREVIOUSLY ANTICIPATED OVER PORTIONS OF CENTRAL/EASTERN KS. ASSOCIATED OUTFLOW BOUNDARY EXTENDS EAST/WEST ACROSS NORTHERN OK...SO ANY ISOLATED CONVECTIVE DEVELOPMENT THIS AFTERNOON/EVENING WILL REMAIN SOUTH OF THE KS/OK BORDER. HOWEVER SIMILAR TO LAST NIGHT...WEAK MONSOONAL ENERGY ROUNDING TOP OF RIDGE COULD PROVIDE ANOTHER ROUND OF SHOWERS/THUNDERSTORMS OVER PORTIONS OF CENTRAL/EAST-CENTRAL KS AFTER MIDNIGHT...ALONG NORTHERN FRINGE OF STOUT 850-700MB THERMAL RIDGE. THINKING HIGHEST PROBABILITIES WILL REMAIN NORTH OF WICHITA. LIKE TODAY...ANY POTENTIAL CONVECTIVE OUTFLOW COULD THROW A WRENCH INTO THURSDAY MAX TEMPERATURES...WITH A WIDE RANGE OF TEMPERATURES LIKELY ACROSS THE BOUNDARY. DUE TO GOOD MIXING AND 30-34C 850MB TEMPERATURES...HIGHS SOUTH OF THE BOUNDARY SHOULD SOAR ABOVE 110 DEGREES...HIGHEST PROBABILITIES OVER SOUTHERN/SOUTHEAST KS. HOWEVER...DUE TO CONVECTIVE OUTFLOW UNCERTAINTIES...WILL PUNT HEAT HEADLINES DECISION TO THE NIGHT SHIFT. DUE TO THE VERY HOT TEMPERATURES AND BOUNDARY IN VICINITY...COULD SEE A FEW HIT-AND-MISS LATE AFTERNOON/EVENING THUNDERSTORMS OVER SOUTHERN KS THURSDAY...WITH ANOTHER ROUND OF SHOWERS/THUNDERSTORMS POSSIBLE THURSDAY NIGHT-EARLY FRIDAY OVER MAINLY CENTRAL KS...AS MORE WEAK MONSOONAL ENERGY TOPS RIDGE. ANOTHER VERY HOT FRIDAY IS ANTICIPATED...WITH AFTERNOON HIGHS LIKELY SOARING ABOVE 105 DEGREES FOR MANY AREAS. LIKE THURSDAY...CANNOT RULE OUT A FEW HIT-AND-MISS AFTERNOON/EVENING THUNDERSTORMS DUE TO WEAK BOUNDARY IN VICINITY. SHORT-MEDIUM RANGE GUIDANCE CONTINUES TO SUGGEST A COLD FRONT WILL PASS SOUTHEAST ACROSS THE REGION SATURDAY...ASSOCIATED WITH AN AMPLIFIED SHORTWAVE TROUGH OVER THE UPPER MISSISSIPPI VALLEY. AFTER ANOTHER HOT DAY OVER SOUTHERN/CENTRAL KS SATURDAY AHEAD OF THE FRONT...READINGS BY SUNDAY SHOULD DROP INTO THE 90S FOR MOST LOCATIONS BEHIND THE FRONT...WHICH WILL BE NEAR SEASONAL NORMALS. ADDITIONALLY...AT LEAST ISOLATED TO WIDELY SCATTERED THUNDERSTORMS WILL BE POSSIBLE ALONG THE FRONT LATE FRIDAY NIGHT...AND ESPECIALLY SATURDAY AFTERNOON/EVENING. HOWEVER...OTHER THAN ISOLATED RELIEF...WIDESPREAD APPRECIABLE RAINS APPEAR UNLIKELY. FOR MONDAY AND BEYOND...UNCERTAINTY EXISTS IN THE MODELS WHETHER THE ABNORMALLY WARM SUMMER TEMPERATURES WILL RETURN. ECMWF SUGGESTS RIDGE WILL BUILD BACK IN...RESULTING IN HOT AND DRY WEATHER RETURNING. HOWEVER...GFS AND ASSOCIATED ENSEMBLES KEEP THE RIDGE CENTERED WEST OF THE REGION...WHICH WOULD RESULT IN READINGS CLOSER TO SEASONAL NORMALS...ALONG WITH PERIODIC CHANCES FOR PRECIPITATION. WILL HOPE THAT THE GFS AND ASSOCIATED ENSEMBLES VERIFY. KLEINSASSER AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU VFR CONDITIONS EXPECTED TO PREVAIL THRU THE FORECAST VALID PERIOD. AN IMPRESSIVE CONVECTIVE OUTFLOW BOUNDARY AND THE EAST TO NORTHEAST WIND FLOW BEHIND IT WILL GRADUALLY WEAKEN THROUGH THE AFTERNOON ACROSS THE AREA. HOWEVER ANOTHER COMPLEX OF STORMS IS LIKELY TO DEVELOP ACROSS THE HIGH PLAINS THIS EVENING...WHICH COULD IMPACT CENTRAL KANSAS AGAIN EARLY THURSDAY MORNING. FOR NOW CONFIDENCE WAS ONLY HIGH ENOUGH TO INSERT VCTS AT KRSL AND KSLN. KED && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 106 77 106 77 / 10 10 10 20 HUTCHINSON 104 77 104 77 / 10 20 10 20 NEWTON 103 76 103 76 / 10 20 20 20 ELDORADO 103 77 104 77 / 10 20 20 20 WINFIELD-KWLD 108 78 109 78 / 10 10 10 20 RUSSELL 100 75 101 75 / 10 40 20 20 GREAT BEND 102 76 102 76 / 10 30 10 20 SALINA 100 75 101 75 / 10 40 20 20 MCPHERSON 102 76 102 76 / 10 30 20 20 COFFEYVILLE 108 78 108 78 / 10 10 20 20 CHANUTE 103 76 102 76 / 10 30 30 20 IOLA 102 75 101 75 / 10 30 30 20 PARSONS-KPPF 105 78 105 78 / 10 20 20 20 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
204 PM EDT THU AUG 2 2012 .UPDATE... ISSUED AT 204 PM EDT THU AUG 2 2012 PREVIOUS FORECAST WAS LARGELY ON TRACK...AND ONLY MINOR ADJUSTMENTS WERE MADE. UPDATE ISSUED AT 1057 AM EDT THU AUG 2 2012 HAVE LOWERED CLOUD COVER FOR TODAY TO GIVE A SUNNY FORECAST OVERALL. WHAT CUMULUS THAT DO POP UP SHOULD BE LIMITED AND MAINLY IN THE FAR SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. HAVE ALSO ADDED A BIT OF THE TYPICAL LATE SUMMER VALLEY FOG FOR LATE TONIGHT. THE NAM IS ALSO ADVECTING ELEVATED INSTABILITY INTO OUR SW COUNTIES OVERNIGHT ON ISENTROPIC LIFT. ALTHOUGH IT IS NOT AS PRONOUNCED IN THE GFS...IT IS PERSISTENT NOW IN THE NAM...AND HAVE ADDED A SLIGHT CHANCE POP FOR THIS. UPDATE ISSUED AT 700 AM EDT THU AUG 2 2012 A FEW CALLS TO LOCAL KSP POSTS REVEALED THAT THERE ARE INDEED SOME AREAS OF DENSE FOG THROUGHOUT THE VALLEYS THIS MORNING...MAINLY EAST OF A LINE FROM ABOUT WEST LIBERTY...THROUGH JACKSON...TO AROUND MIDDLESBORO...THOUGH SOME OF THE STATIONS AROUND THE CUMBERLAND ARE ALSO BEGINNING TO REPORT DETERIORATING VISIBILITIES...AND HAVE ISSUED A SPS THROUGH 9 A.M. TO ACCOUNT FOR THIS. LATEST HRRR ALONG WITH ITS FEW PREVIOUS RUNS CONTINUES TO ADVERTISE SOME ISOLATED...ANEMIC...CONVECTION OVER ERN KY THIS AFTERNOON. HOWEVER...ASIDE FROM THE 02.00Z EURO...THERE IS NOT MUCH SUPPORT FROM ANY OF THE REST OF THE MODELS. FEELING IS THAT MODELS HAVE UNDERREPRESENTED A BIT THE LAST COUPLE OF DAYS...AND TODAY MAY BE MORE OF THE SAME IF THE CAP CAN BE BROKEN...BUT WILL SIT ON THE SUB SLIGHT POPS CURRENTLY ADVERTISED AND PASS ALONG CONCERNS TO THE DAY SHIFT. OTW...NO MAJOR CHANGES IN THINKING ATTM BUT WILL FRESHEN UP THE ZONES TO REMOVE THE PRE FIRST PERIOD. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 340 AM EDT THU AUG 2 2012 SFC ANALYSIS EARLY THIS MORNING SHOWS HIGH PRESSURE OVER THE OHIO VALLEY WITH A RATHER ILL DEFINED BOUNDARY ROUGHLY ALONG THE UPPER OHIO VALLEY THROUGH NRN KY AND ACROSS THE MID MS VALLEY. DEW PTS ARE GENERALLY RUNNING IN THE MID TO UPPER 60S SOUTH OF THIS BOUNDARY... INCLUDING ERN KY...WITH SLIGHTLY DRIER AIR TO THE NORTH. CURRENT IR SHOT SHOWS FOG HAS ALREADY DEVELOPED ALONG THE UPPER REGIONS OF THE CUMBERLAND...KENTUCKY...LICKING...AND SANDY BASINS...WHERE THE HEAVIER RAINS FELL YESTERDAY...HOWEVER LOCAL OBS AND WEB CAMS HAVE YET TO INDICATE THAT THE DENSEST FOG HAS BECOME WIDESPREAD ENOUGH TO WARRANT ANY HEADLINES JUST YET. WITH A FEW MORE HOURS OF GOOD RADIATIONAL COOLING LEFT...WILL CONTINUE TO KEEP AN EYE ON THIS IN CASE IT BEGINS TO LOOK LIKE IT WILL AFFECT THE MORNING COMMUTE. OTHERWISE...HIGH PRESSURE LOOKS TO BE IN THE DRIVERS SEAT TODAY PROVIDING FOR GENERALLY CLEAR SKIES THROUGH MUCH OF THE DAY WITH FCST HIGHS TARGETING THE LOWER 90S...AND A FEW LOCALS AROUND THE CUMBERLAND VALLEY POSSIBLY SNEAKING INTO THE MID 90S THIS AFTERNOON. CANNOT RULE OUT SOME INCREASING CU THIS AFTERNOON WITH THE LOWER LEVELS BECOMING RATHER UNSTABLE BUT FCST SOUNDINGS INDICATE A FAIRLY SOLID CAP AROUND H8 AND THIS SHOULD KEEP A LID ON ANY CONVECTION TODAY. GUIDANCE REMAINS IN GOOD AGREEMENT WITH BRINGING A ROBUST SHORT WAVE ACROSS THE MID MS VALLEY INTO THE TN VALLEY LATE TONIGHT AND THROUGH THE DAY ON FRIDAY. MODELS ARE STILL GRAPPLING WITH THE IDEA OF A DECAYING MCS MOVING INTO WRN TN TOWARDS DAWN ON FRIDAY. WITH A STABLE ATMOSPHERE EXPECTED TO BE IN PLACE OVER ERN KY...DO NOT FORESEE ANY POTENTIAL FOR PRECIP OVERNIGHT. HOWEVER...MOISTURE IS PROGGED TO BEGIN INCREASING EARLY ON FRIDAY AND WITH THAT IDEA IN MIND COUPLED WITH THE POTENTIAL FOR OUTFLOWS FROM ACTIVITY TO THE SW PUSHING NORTH INTO THE AREA...HAVE RAISED POPS ACROSS THE BOARD FOR US ON FRIDAY. TEMPS OF COURSE WILL BE LARGELY DEPENDENT ON WHO GETS RAIN...BUT THE CURRENT POPS SCHEME WOULD ALLOW THE BLUEGRASS TO REACH INTO THE MID 90S WITH HIGHS A LITTLE CLOSER TO 90 IN THE SOUTH. THERE IS A GOOD POSSIBILITY THAT THERE WILL BE A RATHER SHARP GRADIENT BETWEEN WHO SEES RAIN AND WHO DOES NOT...BUT ATTM THE BETTER CHANCES STILL LOOK TO BE CLOSER TO THE KY/TN LINE. NAM AND GFS BUFR SOUNDINGS ARE OFFERING DIFFERENT SCENARIOS THIS MORNING...WITH THE GFS LEANING MORE TOWARDS A LOCALLY HEAVY RAIN THREAT WHILE THE NAM WOULD SUGGEST A POTENTIAL FOR DAMAGING WINDS. WILL HEDGE FOR THE MOMENT AND MENTION BOTH IN THE HWO. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 245 AM EDT THU AUG 2 2012 THE WEEKEND STARTS WITH A NEARLY ZONAL PATTERN AT 50H FOR THE ERN HALF OF THE CONUS. AN AREA OF LOW PRESSURE IS TRACKING ACROSS THE NRN US PLAINS BORDER WITH CANADA AND THEN ACROSS THE NRN GREAT LAKES. BY SUNDAY THE 50H LOW AND THE SFC ASPECT OF THIS SYSTEM WILL DRAG A COLD FRONT ACROSS THE COMMONWEALTH. EXPECT LIKELY SHRA/TSRA FOR ERN KY FROM LATE FRI NIGHT THRU MUCH OF THE WEEKEND. EVEN INTO MONDAY AFTERNOON...THE HEATING AND HIGH DEWPOINTS WILL PRODUCE CHANCE POPS FOR THE REGION. RELIEF FROM THE RAIN WILL ARRIVE ON MONDAY NIGHT AS THE SETTING SUN WILL STABILIZE THE AIR MASS AND FINALLY GIVE THE AREA A TWO DAY BREAK FROM THE RAIN. THEN THE NORTHWEST FLOW WILL BEGIN AGAIN AS A TROF BECOMES ESTABLISHED OVER THE ATLANTIC COAST. THIS PATTERN NEARLY ALWAYS BRING RAIN BUT THE DISTURBANCES ARE DIFFICULT TO TIME SO WOULD RATHER BROAD BRUSH THE POPS BEGINNING LATE WEDNESDAY. TEMPERATURES WILL FALL SLIGHTLY WITH THE PASSING FRONT ON SUNDAY AND DROP DAY TIME HIGHS INTO THE MID 80S BEFORE THEY CAN REBOUND BY WED WITH HIGH READING CLIMBING BACK INTO THE UPPER 80S AND LOWER 90S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 204 PM EDT THU AUG 2 2012 MOST VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. THERE WILL BE A COUPLE OF EXCEPTIONS...THOUGH. VALLEY FOG WILL BRING LOCALIZED IFR LATE TONIGHT INTO EARLY FRIDAY MORNING. THUNDERSTORMS MAY DEVELOP FROM SW TO NE OVER THE AREA OVERNIGHT AND ON FRIDAY. AT THIS POINT...THE PROBABILITY LOOKS TOO LOW TO WARRANT ANYTHING MORE THAN VCTS AT TAF SITES. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...MB LONG TERM....DUSTY AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
1057 AM EDT THU AUG 2 2012 .UPDATE... ISSUED AT 1057 AM EDT THU AUG 2 2012 HAVE LOWERED CLOUD COVER FOR TODAY TO GIVE A SUNNY FORECAST OVERALL. WHAT CUMULUS THAT DO POP UP SHOULD BE LIMITED AND MAINLY IN THE FAR SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. HAVE ALSO ADDED A BIT OF THE TYPICAL LATE SUMMER VALLEY FOG FOR LATE TONIGHT. THE NAM IS ALSO ADVECTING ELEVATED INSTABILITY INTO OUR SW COUNTIES OVERNIGHT ON ISENTROPIC LIFT. ALTHOUGH IT IS NOT AS PRONOUNCED IN THE GFS...IT IS PERSISTENT NOW IN THE NAM...AND HAVE ADDED A SLIGHT CHANCE POP FOR THIS. UPDATE ISSUED AT 700 AM EDT THU AUG 2 2012 A FEW CALLS TO LOCAL KSP POSTS REVEALED THAT THERE ARE INDEED SOME AREAS OF DENSE FOG THROUGHOUT THE VALLEYS THIS MORNING...MAINLY EAST OF A LINE FROM ABOUT WEST LIBERTY...THROUGH JACKSON...TO AROUND MIDDLESBORO...THOUGH SOME OF THE STATIONS AROUND THE CUMBERLAND ARE ALSO BEGINNING TO REPORT DETERIORATING VISIBILITIES...AND HAVE ISSUED A SPS THROUGH 9 A.M. TO ACCOUNT FOR THIS. LATEST HRRR ALONG WITH ITS FEW PREVIOUS RUNS CONTINUES TO ADVERTISE SOME ISOLATED...ANEMIC...CONVECTION OVER ERN KY THIS AFTERNOON. HOWEVER...ASIDE FROM THE 02.00Z EURO...THERE IS NOT MUCH SUPPORT FROM ANY OF THE REST OF THE MODELS. FEELING IS THAT MODELS HAVE UNDERREPRESENTED A BIT THE LAST COUPLE OF DAYS...AND TODAY MAY BE MORE OF THE SAME IF THE CAP CAN BE BROKEN...BUT WILL SIT ON THE SUB SLIGHT POPS CURRENTLY ADVERTISED AND PASS ALONG CONCERNS TO THE DAY SHIFT. OTW...NO MAJOR CHANGES IN THINKING ATTM BUT WILL FRESHEN UP THE ZONES TO REMOVE THE PRE FIRST PERIOD. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 340 AM EDT THU AUG 2 2012 SFC ANALYSIS EARLY THIS MORNING SHOWS HIGH PRESSURE OVER THE OHIO VALLEY WITH A RATHER ILL DEFINED BOUNDARY ROUGHLY ALONG THE UPPER OHIO VALLEY THROUGH NRN KY AND ACROSS THE MID MS VALLEY. DEW PTS ARE GENERALLY RUNNING IN THE MID TO UPPER 60S SOUTH OF THIS BOUNDARY... INCLUDING ERN KY...WITH SLIGHTLY DRIER AIR TO THE NORTH. CURRENT IR SHOT SHOWS FOG HAS ALREADY DEVELOPED ALONG THE UPPER REGIONS OF THE CUMBERLAND...KENTUCKY...LICKING...AND SANDY BASINS...WHERE THE HEAVIER RAINS FELL YESTERDAY...HOWEVER LOCAL OBS AND WEB CAMS HAVE YET TO INDICATE THAT THE DENSEST FOG HAS BECOME WIDESPREAD ENOUGH TO WARRANT ANY HEADLINES JUST YET. WITH A FEW MORE HOURS OF GOOD RADIATIONAL COOLING LEFT...WILL CONTINUE TO KEEP AN EYE ON THIS IN CASE IT BEGINS TO LOOK LIKE IT WILL AFFECT THE MORNING COMMUTE. OTHERWISE...HIGH PRESSURE LOOKS TO BE IN THE DRIVERS SEAT TODAY PROVIDING FOR GENERALLY CLEAR SKIES THROUGH MUCH OF THE DAY WITH FCST HIGHS TARGETING THE LOWER 90S...AND A FEW LOCALS AROUND THE CUMBERLAND VALLEY POSSIBLY SNEAKING INTO THE MID 90S THIS AFTERNOON. CANNOT RULE OUT SOME INCREASING CU THIS AFTERNOON WITH THE LOWER LEVELS BECOMING RATHER UNSTABLE BUT FCST SOUNDINGS INDICATE A FAIRLY SOLID CAP AROUND H8 AND THIS SHOULD KEEP A LID ON ANY CONVECTION TODAY. GUIDANCE REMAINS IN GOOD AGREEMENT WITH BRINGING A ROBUST SHORT WAVE ACROSS THE MID MS VALLEY INTO THE TN VALLEY LATE TONIGHT AND THROUGH THE DAY ON FRIDAY. MODELS ARE STILL GRAPPLING WITH THE IDEA OF A DECAYING MCS MOVING INTO WRN TN TOWARDS DAWN ON FRIDAY. WITH A STABLE ATMOSPHERE EXPECTED TO BE IN PLACE OVER ERN KY...DO NOT FORESEE ANY POTENTIAL FOR PRECIP OVERNIGHT. HOWEVER...MOISTURE IS PROGGED TO BEGIN INCREASING EARLY ON FRIDAY AND WITH THAT IDEA IN MIND COUPLED WITH THE POTENTIAL FOR OUTFLOWS FROM ACTIVITY TO THE SW PUSHING NORTH INTO THE AREA...HAVE RAISED POPS ACROSS THE BOARD FOR US ON FRIDAY. TEMPS OF COURSE WILL BE LARGELY DEPENDENT ON WHO GETS RAIN...BUT THE CURRENT POPS SCHEME WOULD ALLOW THE BLUEGRASS TO REACH INTO THE MID 90S WITH HIGHS A LITTLE CLOSER TO 90 IN THE SOUTH. THERE IS A GOOD POSSIBILITY THAT THERE WILL BE A RATHER SHARP GRADIENT BETWEEN WHO SEES RAIN AND WHO DOES NOT...BUT ATTM THE BETTER CHANCES STILL LOOK TO BE CLOSER TO THE KY/TN LINE. NAM AND GFS BUFR SOUNDINGS ARE OFFERING DIFFERENT SCENARIOS THIS MORNING...WITH THE GFS LEANING MORE TOWARDS A LOCALLY HEAVY RAIN THREAT WHILE THE NAM WOULD SUGGEST A POTENTIAL FOR DAMAGING WINDS. WILL HEDGE FOR THE MOMENT AND MENTION BOTH IN THE HWO. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 245 AM EDT THU AUG 2 2012 THE WEEKEND STARTS WITH A NEARLY ZONAL PATTERN AT 50H FOR THE ERN HALF OF THE CONUS. AN AREA OF LOW PRESSURE IS TRACKING ACROSS THE NRN US PLAINS BORDER WITH CANADA AND THEN ACROSS THE NRN GREAT LAKES. BY SUNDAY THE 50H LOW AND THE SFC ASPECT OF THIS SYSTEM WILL DRAG A COLD FRONT ACROSS THE COMMONWEALTH. EXPECT LIKELY SHRA/TSRA FOR ERN KY FROM LATE FRI NIGHT THRU MUCH OF THE WEEKEND. EVEN INTO MONDAY AFTERNOON...THE HEATING AND HIGH DEWPOINTS WILL PRODUCE CHANCE POPS FOR THE REGION. RELIEF FROM THE RAIN WILL ARRIVE ON MONDAY NIGHT AS THE SETTING SUN WILL STABALIZE THE AIR MASS AND FINALLY GIVE THE AREA A TWO DAY BREAK FROM THE RAIN. THEN THE NORTHWEST FLOW WILL BEGIN AGAIN AS A TROF BECOMES ESTABLISHED OVER THE ATLANTIC COAST. THIS PATTERN NEARLY ALWAYS BRING RAIN BUT THE DISTURBANCES ARE DIFFICULT TO TIME SO WOULD RATHER BROAD BRUSH THE POPS BEGINNING LATE WEDNESDAY. TEMPERATURES WILL FALL SLIGHTLY WITH THE PASSING FRONT ON SUNDAY AND DROP DAY TIME HIGHS INTO THE MID 80S BEFORE THEY CAN REBOUND BY WED WITH HIGH READING CLIMBING BACK INTO THE UPPER 80S AND LOWER 90S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 700 AM EDT THU AUG 2 2012 MVFR FOG IS AFFECTING SOME OF THE TERMINALS EARLY THIS MORNING WITH SITES SUCH AS KLOZ...KEKQ...AND K1A6 LIKELY TO SEE IFR BEFORE THE FOG BEGINS TO LIFT AND MIX OUT BY 13Z. CLR SKIES THIS MORNING MAY GIVE WAY TO SCT CU THIS AFTERNOON BEFORE CIGS BEGIN TO INCREASE LATE TONIGHT AS A DISTURBANCE CURRENTLY OVER THE CENTRAL PLAINS APPROACHES THE TN VALLEY. HOWEVER...CIGS ARE EXPECTED TO REMAIN AOA 5KFT AND...ONCE THE FOG LIFTS THIS MORNING...VFR AND LIGHT WINDS SHOULD BE THE RULE THROUGH THE REMAINDER OF THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...MB LONG TERM....DUSTY AVIATION...MB
AREA FORECAST DISCUSSION
NWS JACKSON KY
700 AM EDT THU AUG 2 2012 .UPDATE... ISSUED AT 700 AM EDT THU AUG 2 2012 A FEW CALLS TO LOCAL KSP POSTS REVEALED THAT THERE ARE INDEED SOME AREAS OF DENSE FOG THROUGHOUT THE VALLEYS THIS MORNING...MAINLY EAST OF A LINE FROM ABOUT WEST LIBERTY...THROUGH JACKSON...TO AROUND MIDDLESBORO...THOUGH SOME OF THE STATIONS AROUND THE CUMBERLAND ARE ALSO BEGINNING TO REPORT DETERIORATING VISIBILITIES...AND HAVE ISSUED A SPS THROUGH 9 A.M. TO ACCOUNT FOR THIS. LATEST HRRR ALONG WITH ITS FEW PREVIOUS RUNS CONTINUES TO ADVERTISE SOME ISOLATED...ANEMIC...CONVECTION OVER ERN KY THIS AFTERNOON. HOWEVER...ASIDE FROM THE 02.00Z EURO...THERE IS NOT MUCH SUPPORT FROM ANY OF THE REST OF THE MODELS. FEELING IS THAT MODELS HAVE UNDERREPRESENTED A BIT THE LAST COUPLE OF DAYS...AND TODAY MAY BE MORE OF THE SAME IF THE CAP CAN BE BROKEN...BUT WILL SIT ON THE SUB SLIGHT POPS CURRENTLY ADVERTISED AND PASS ALONG CONCERNS TO THE DAY SHIFT. OTW...NO MAJOR CHANGES IN THINKING ATTM BUT WILL FRESHEN UP THE ZONES TO REMOVE THE PRE FIRST PERIOD. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 340 AM EDT THU AUG 2 2012 SFC ANALYSIS EARLY THIS MORNING SHOWS HIGH PRESSURE OVER THE OHIO VALLEY WITH A RATHER ILL DEFINED BOUNDARY ROUGHLY ALONG THE UPPER OHIO VALLEY THROUGH NRN KY AND ACROSS THE MID MS VALLEY. DEW PTS ARE GENERALLY RUNNING IN THE MID TO UPPER 60S SOUTH OF THIS BOUNDARY... INCLUDING ERN KY...WITH SLIGHTLY DRIER AIR TO THE NORTH. CURRENT IR SHOT SHOWS FOG HAS ALREADY DEVELOPED ALONG THE UPPER REGIONS OF THE CUMBERLAND...KENTUCKY...LICKING...AND SANDY BASINS...WHERE THE HEAVIER RAINS FELL YESTERDAY...HOWEVER LOCAL OBS AND WEB CAMS HAVE YET TO INDICATE THAT THE DENSEST FOG HAS BECOME WIDESPREAD ENOUGH TO WARRANT ANY HEADLINES JUST YET. WITH A FEW MORE HOURS OF GOOD RADIATIONAL COOLING LEFT...WILL CONTINUE TO KEEP AN EYE ON THIS IN CASE IT BEGINS TO LOOK LIKE IT WILL AFFECT THE MORNING COMMUTE. OTHERWISE...HIGH PRESSURE LOOKS TO BE IN THE DRIVERS SEAT TODAY PROVIDING FOR GENERALLY CLEAR SKIES THROUGH MUCH OF THE DAY WITH FCST HIGHS TARGETING THE LOWER 90S...AND A FEW LOCALS AROUND THE CUMBERLAND VALLEY POSSIBLY SNEAKING INTO THE MID 90S THIS AFTERNOON. CANNOT RULE OUT SOME INCREASING CU THIS AFTERNOON WITH THE LOWER LEVELS BECOMING RATHER UNSTABLE BUT FCST SOUNDINGS INDICATE A FAIRLY SOLID CAP AROUND H8 AND THIS SHOULD KEEP A LID ON ANY CONVECTION TODAY. GUIDANCE REMAINS IN GOOD AGREEMENT WITH BRINGING A ROBUST SHORT WAVE ACROSS THE MID MS VALLEY INTO THE TN VALLEY LATE TONIGHT AND THROUGH THE DAY ON FRIDAY. MODELS ARE STILL GRAPPLING WITH THE IDEA OF A DECAYING MCS MOVING INTO WRN TN TOWARDS DAWN ON FRIDAY. WITH A STABLE ATMOSPHERE EXPECTED TO BE IN PLACE OVER ERN KY...DO NOT FORESEE ANY POTENTIAL FOR PRECIP OVERNIGHT. HOWEVER...MOISTURE IS PROGGED TO BEGIN INCREASING EARLY ON FRIDAY AND WITH THAT IDEA IN MIND COUPLED WITH THE POTENTIAL FOR OUTFLOWS FROM ACTIVITY TO THE SW PUSHING NORTH INTO THE AREA...HAVE RAISED POPS ACROSS THE BOARD FOR US ON FRIDAY. TEMPS OF COURSE WILL BE LARGELY DEPENDENT ON WHO GETS RAIN...BUT THE CURRENT POPS SCHEME WOULD ALLOW THE BLUEGRASS TO REACH INTO THE MID 90S WITH HIGHS A LITTLE CLOSER TO 90 IN THE SOUTH. THERE IS A GOOD POSSIBILITY THAT THERE WILL BE A RATHER SHARP GRADIENT BETWEEN WHO SEES RAIN AND WHO DOES NOT...BUT ATTM THE BETTER CHANCES STILL LOOK TO BE CLOSER TO THE KY/TN LINE. NAM AND GFS BUFR SOUNDINGS ARE OFFERING DIFFERENT SCENARIOS THIS MORNING...WITH THE GFS LEANING MORE TOWARDS A LOCALLY HEAVY RAIN THREAT WHILE THE NAM WOULD SUGGEST A POTENTIAL FOR DAMAGING WINDS. WILL HEDGE FOR THE MOMENT AND MENTION BOTH IN THE HWO. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 245 AM EDT THU AUG 2 2012 THE WEEKEND STARTS WITH A NEARLY ZONAL PATTERN AT 50H FOR THE ERN HALF OF THE CONUS. AN AREA OF LOW PRESSURE IS TRACKING ACROSS THE NRN US PLAINS BORDER WITH CANADA AND THEN ACROSS THE NRN GREAT LAKES. BY SUNDAY THE 50H LOW AND THE SFC ASPECT OF THIS SYSTEM WILL DRAG A COLD FRONT ACROSS THE COMMONWEALTH. EXPECT LIKELY SHRA/TSRA FOR ERN KY FROM LATE FRI NIGHT THRU MUCH OF THE WEEKEND. EVEN INTO MONDAY AFTERNOON...THE HEATING AND HIGH DEWPOINTS WILL PRODUCE CHANCE POPS FOR THE REGION. RELIEF FROM THE RAIN WILL ARRIVE ON MONDAY NIGHT AS THE SETTING SUN WILL STABALIZE THE AIR MASS AND FINALLY GIVE THE AREA A TWO DAY BREAK FROM THE RAIN. THEN THE NORTHWEST FLOW WILL BEGIN AGAIN AS A TROF BECOMES ESTABLISHED OVER THE ATLANTIC COAST. THIS PATTERN NEARLY ALWAYS BRING RAIN BUT THE DISTURBANCES ARE DIFFICULT TO TIME SO WOULD RATHER BROAD BRUSH THE POPS BEGINNING LATE WEDNESDAY. TEMPERATURES WILL FALL SLIGHTLY WITH THE PASSING FRONT ON SUNDAY AND DROP DAY TIME HIGHS INTO THE MID 80S BEFORE THEY CAN REBOUND BY WED WITH HIGH READING CLIMBING BACK INTO THE UPPER 80S AND LOWER 90S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 700 AM EDT THU AUG 2 2012 MVFR FOG IS AFFECTING SOME OF THE TERMINALS EARLY THIS MORNING WITH SITES SUCH AS KLOZ...KEKQ...AND K1A6 LIKELY TO SEE IFR BEFORE THE FOG BEGINS TO LIFT AND MIX OUT BY 13Z. CLR SKIES THIS MORNING MAY GIVE WAY TO SCT CU THIS AFTERNOON BEFORE CIGS BEGIN TO INCREASE LATE TONIGHT AS A DISTURBANCE CURRENTLY OVER THE CENTRAL PLAINS APPROACHES THE TN VALLEY. HOWEVER...CIGS ARE EXPECTED TO REMAIN AOA 5KFT AND...ONCE THE FOG LIFTS THIS MORNING...VFR AND LIGHT WINDS SHOULD BE THE RULE THROUGH THE REMAINDER OF THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MB SHORT TERM...MB LONG TERM....DUSTY AVIATION...MB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1025 PM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA THIS EVENING AND MOST OFF THE COAST OVERNIGHT. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR SATURDAY INTO SUNDAY. && .NEAR TERM /THROUGH SATURDAY/... 10PM UPDATE...NO CHANGES. PATCHY FOG STILL EXPECTED THROUGH MUCH OF THE NIGHT. PREV DISCUSSION... CHALLENGES WILL ARE CONVECTION THIS AFTERNOON INTO THE EVENING AND HOW STRONG AND HOW EXTENSIVE WILL THE FOG BE. TSTMS FIRING ACROSS NORTHERN AND CENTRAL AREAS ATTM AHEAD OF THE APCHG COLD FRONT. STILL EXPECTING CONVECTION TO FIRE UP ACROSS PORTIONS OF THE CENTRAL HIGHLANDS AND DOWNEAST REGIONS LATER THIS AFTERNOON AS BEST INSTABILITY SHIFTS SSE. SPC MESO-ANALYSIS INDICATES THIS ATTM. ALSO, THINKING HEAVY RAINFALL AND STRONG WIND GUSTS STILL POSSIBLE. SBCAPES UP AROUND 2000+ JOULES W/LIS DOWN TO AROUND -5. 0-6KM SHEAR FROM THE LATEST RUC WAS AROUND 25KTS WHICH WOULD FAVOR POSSIBLE DOWNBURST WINDS. EXPECTING CONVECTION TO WIND DOWN THIS EVENING AS INSTABILITY AXIS SHIFTS EAST INTO NEW BRUNSWICK. COLD FRONT WILL CLEAR THE COAST TONIGHT W /DRIER-COOLER AIR EXPECTED TO FILTER BEHIND THE FRONT. MIDNIGHT CREW/S OVERNIGHT MINS OF LOW/MID 50S ACROSS THE NORTH W /MID-UPPER 50S CENTRAL AND DOWNEAST LOOKED GOOD. THE OTHER CONCERN IS FOG RETURNING OVERNIGHT INTO SATURDAY MORNING. DECIDED ON AREAS OF FOG RIGHT ALONG THE IMMEDIATE COAST AND OVER THE WATERS. FURTHER INLAND, WENT W/PATCHY FOG FOR NOW GIVEN THE DRYING TREND. THERE COULD BE A BRIEF TIME WHEN VSBYS DROP LOWER AS DEWPOINT ALIGNS W/THE TEMPERATURE. THIS WILL BE ESPECIALLY TRUE IN AREAS FROM EARLIER RAINFALL. HIGH PRES BUILDING INTO THE REGION FROM CANADA ON SATURDAY WILL PROVIDE DRY AND PLEASANT CONDITIONS FOR EARLY AUGUST. MAX TEMPERATURES SHOULD HAVE NO PROBLEM REACHING WELL INTO THE 80S W/AMPLE SUNSHINE. LATEST MOS/NAM MAXES MATCHED CLOSE TO WHAT THE MIDNIGHT CREW HAS AND THEREFORE ONLY TWEAKING WAS DONE FOR THE COAST TO BRING MAXES UP DUE TO OFFSHORE WINDS. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... A WARM FRONT WILL LIFT NORTH THROUGH THE REGION SATURDAY NIGHT INTO SUNDAY USHERING IN VERY WARM AND HUMID CONDITIONS. EXPECT HIGHS SUNDAY GENERALLY IN THE MID 80S WITH DEW POINTS RISING INTO THE MID TO HIGH 60S. WINDS WILL BE GUSTY OUT OF THE SOUTH AND THIS WILL HELP TO KEEP TEMPERATURES COOLER ALONG THE COAST WHERE HIGHS WILL BE IN THE 70S. CLOUDS WILL INCREASE IN THE AFTERNOON AHEAD OF AN APPROACHING COLD FRONT BUT ANY SHOWER/THUNDERSTORM ACTIVITY LOOKS TO REMAIN WEST OF THE REGION THROUGH THE DAY. AS THE COLD FRONT CONTINUES TO ADVANCE SUNDAY NIGHT SHOWERS WITH POSSIBLE THUNDERSTORMS WILL ROLL THROUGH FROM WEST TO EAST AHEAD OF FRONT DURING THE LATE EVENING INTO THE OVERNIGHT. INSTABILITY LOOKS TO BE MARGINAL DUE TO THE TIMING OF THE FRONT BEING AT NIGHT AND AS A RESULT ANY CONVECTION THAT OCCURS DOES NOT LOOK TO BE SEVERE, ALTHOUGH SOME HEAVY DOWNPOURS WILL BE POSSIBLE. BY MONDAY MORNING THE FRONT LOOKS TO BE SITUATED CLOSE TO THE WESTERN EDGE OF THE STATE. SHOWERS AND STORMS WILL CLEAR THE AREA FROM WEST TO EAST THROUGH THE DAY AS THE FRONT ADVANCES EAST. THE BEST CHANCE FOR ANY STRONGER STORMS MONDAY WILL BE DOWNEAST AS THAT AREA WILL BE LAST TO CLEAR DURING THE AFTERNOON. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ZONAL FLOW WILL DEVELOP BEHIND AN EXITING COLD FRONT MONDAY NIGHT. DRY WEATHER IS EXPECTED IN THE WAKE OF THIS FRONT THROUGH TUESDAY NIGHT. THE PERSISTENT SUMMER 2012 UPPER TROUGH RETURNS WEDNESDAY THROUGH FRIDAY. ANTICIPATE A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS DAYS 5 THROUGH 7 WITH DISTURBANCES ROTATING AROUND THE BASE OF THE TROUGH. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE LONG TERM PERIOD. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: VFR W/TEMPO MVFR THIS AFTERNOON INTO THE EVENING W/TSTMS FIRING. LEANED W/MVFR VSBY LATER TONIGHT INTO SATURDAY MORNING FOR THE NORTHERN TERMINALS WHILE KBGR AND KBHB ARE EXPECTED TO DROP TO IFR BY 09Z SATURDAY. AFTER 12Z SATURDAY, LOOKS LIKE VFR. SHORT TERM: LOOKS LIKE VFR SATURDAY NIGHT INTO SUNDAY FOR THE MOST PART. HOWEVER, MVFR AND IFR POSSIBLE ACROSS KBGR AND KBHB COULD BE SEEN EARLY SUNDAY MORNING AS WINDS BECOME SOUTHERLY AHEAD OF AN APPROACHING COLD FRONT. SUNDAY NIGHT INTO MONDAY COULD BE INTERESTING AS THAT STRONGER COLD FRONT MOVES ACROSS THE REGION W/POSSIBLE TSTMS AND WIND AND MVFR/IFR CONDITIONS. && .MARINE... NEAR TERM: NO HEADLINES. MAIN CHALLEGE WILL THE CONTINUING 4-5 FOOT SWELL WHICH IS OUT THERE ATTM. WINDS WILL INCREASE SOME OVERNIGHT W/THE COLD FROPA, BUT WINDS WILL RELAX ON SATURDAY AS HIGH PRES MOVES IN FROM CANADA. AREAS OF FOG WILL BE NUISANCE OVERNIGHT BUT VSBYS SHOULD IMPROVE LATER SATURDAY MORNING. USED THE NAM12 AND GFS FOR THE WINDS WHICH SUPPORT 10-15 KTS TONIGHT AND THEN SPEEDS FROP OFF FOR SATURDAY. BROUGHT THE SWELL DOWN TO 3 FT BY MIDDAY SATURDAY W/AN OFFSHORE FLOW. SHORT TERM: POSSIBLE SCA FOR SUNDAY NIGHT INTO MONDAY AS PRES GRADIENT TIGHTEN AHEAD AND W/THE FRONTAL PASSAGE. WINDS START COMING DOWN LATER MONDAY INTO TUESDAY. BACKED OFF A BIT ON THE WNAWAVE BY DROPPING THEM BACK 1-2 FEET. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT/RUNYAN SHORT TERM...FITZSIMMONS LONG TERM...OKULSKI AVIATION...HEWITT/RUNYAN MARINE...HEWITT/RUNYAN/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
157 PM EDT THU AUG 2 2012 .SYNOPSIS... A WEAKENING COLD FRONT WILL CROSS THE REGION THIS AFTERNOON. ANOTHER COLD FRONT WILL CROSS THE AREA ON FRIDAY. HIGH PRESSURE WILL RETURN FOR SATURDAY WITH PLEASANTLY WARM BUT LESS HUMID AIR. WARMER AND MORE HUMID CONDITIONS RETURN ON SUNDAY AHEAD OF ANOTHER COLD FRONT EXPECTED TO CROSS THE AREA ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE: ADDED HEAVY RAIN WORDING THE WX ELEMENT AS STORM MOTION LESS THAN 10 KTS AND LATEST LAPS SOUNDINGS INDICATE K INDEX OF 35+ WEHRE STORMS ARE FIRING. STORMS ARE SLOW MOVING AND COULD DUMP UP TO 1"RAFL/HR. PREVIOUS DISCUSSION... WIDELY SCATTERED TSTMS EXPECTED THIS AFTERNOON RIGHT ALONG THE FRONT. LATEST HRRR SHOWED A LINE OF BROKEN CONVECTION SETTING UP THIS AFTERNOON BUT NOT SEVERE. IT LOOK LIKE ANY TSTMS WILL HAVE HEAVY RAIN AS WBZS ARE ABOVE 11K FT AND FORCING IN RATHER WEAK. THERE IS SOME LLVL CONVERGENCE SETTING UP AHEAD AND ALONG THE BOUNDARY AS IT MOVES THROUGH THIS AFTERNOON. THEREFORE, ADJUSTED POPS DOWN A BIT DUE TO THIS THINKING. PREVIOUS DISCUSSION... VERY WEAK FRONTAL BNDRY CURRENTLY JUST W AND NW OF THE AREA W/ A MILD AND RATHER HUMID LGT SRLY IN PLACE ACROSS OUR REGION AHEAD OF THIS SYSTEM... A FEW VRY LGT SHOWERS APPEAR TO BE LIFTING NE ACROSS THE FA PER RADAR THO NO RPTG STATIONS HAVE CARRIED ANY PRECIP LAST FEW HRS. EVEN AN ISOLD TSTM NOTED JUST W OF OUR BORDER ATTM - TO THE NW OF DAAQUAM. OTHER FEATURE OF INTEREST ERLY THIS AM IS ANOTHER LOW PRES SYSTEM WELL SW OF THEN AREA - JUST S OF THE CAPE... THE WEAK FRONTAL BNDRY WILL CONT TO SLOWLY CROSS THE AREA TDY W/ A BIT STRONGER FRONT ADVERTISED FOR FRI. LOW PRES WELL SW OF THE AREA SIMILAR TO THE SYSTEM THAT AFFECTED THE REGION YESTERDAY - THO WEAKER W/ THIS ONE EXPECTED TO TRACK A LITTLE FURTHER S AND E OF THE AREA. AS A RESULT...EXPECT PRECIP ASSOCIATED W/ THIS SYSTEM TO NOT BE A FACTOR... WILL CONT W/ PREVIOUS FCST THINKING AND WILL CARRY JUST CHC POPS TDY ACROSS THE FA AS UPPER SUPPORT W/ THIS SYSTEM APPEARS RELATIVELY WEAK. SYSTEM SUPPORTED SOME CONVECTION TO OUR W YESTERDAY AND W/ TDS IN THE 60S TDY...SFC HEATING SHOULD ALLOW FOR A THREAT OF THUNDER OUR AREA TDY AS WELL SPCLY DURING THE AFTN HRS. TEMPS EXPECTED TO WARM A FEW DEGREES OVER YESTERDAY W/ LOWS TNGT AGAIN SIMILAR TO THE LAST FEW NGTS. LATE NGT/ERLY AM LOW CIGS AND FOG A CONTG THREAT...SPCLY ACROSS THE SRN AREAS NEAR THE COAST. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... A COLD FRONT WILL MOVE ACROSS THE REGION ON FRIDAY, BRINGING THE CHANCES FOR SHOWERS AND THUNDERSTORMS TO MUCH OF THE STATE. AHEAD OF THE FRONT, SOUTH FLOW WILL KEEP MUGGY CONDITIONS AROUND AS DEWPOINTS REACH INTO THE LOWER AND MID 60S. HIGHS WILL RANGE FROM AROUND 80 IN THE SAINT JOHN VALLEY TO THE UPPER 80S ACROSS THE INTERIOR DOWNEAST. DRIER AIR WILL WORK INTO THE REGION BEHIND THE FRONT, LEADING TO A PLEASANT NIGHT FRIDAY NIGHT. HOWEVER, HUMIDITY WILL BEGIN TO MAKE ITS RETURN TO MAINE LATE SATURDAY AS THE COLD FRONT SLOWLY MOVES BACK NORTH AS A WARM FRONT. NORTHERN AREAS WILL SEE A NICE SUMMER DAY ON SATURDAY WITH HIGHS AROUND 80 AND LOW HUMIDITY. MEANWHILE, DOWNEAST MAINE WILL SEE A RETURN TO MUCH WARMER AND MUGGIER CONDITIONS; HIGHS WILL BE IN THE MID 80S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE WARM FRONT LIFTS ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY AS LOW PRESSURE MOVES EASTWARD THROUGH THE GREAT LAKES. THIS SYSTEM WILL MOVE NORTH OF THE FORECAST AREA SUNDAY NIGHT INTO MONDAY, DRAGGING ITS ATTENDANT COLD FRONT ACROSS NEW ENGLAND AS IT DOES SO. AS SUCH, THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE LATE SUNDAY, BUT ESPECIALLY LATE SUNDAY NIGHT INTO MONDAY. THIS FRONT WILL BE FOLLOWED BY A BRIEF RIDGE OF HIGH PRESSURE, BRINGING COOLER TEMPERATURES AND DRY WEATHER FOR MONDAY NIGHT AND TUESDAY. PRECIP CHANCES THEN INCREASE AGAIN BY MID WEEK AS ANOTHER FRONT MOVES INTO NORTHERN MAINE. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... NEAR TERM: CURRENTLY KBHB AND KBGR IFR W/ OUR REMAINING TAF SITES VFR... EXPECT SOME LOWER CIGS TO ARRIVE KHUL NEXT HR OR SO BUT AM NOT CONFIDENT THAT THESE CONDS WILL REACH OUR NRN TAF SITES ERLY THIS AM. FOR NOW WILL JUST ADVERTISE SOME MVFR UP N IN BR W/ CONFIDENCE LOW ATTM. MORE OF THE SAME TNGT W/ BEST THREAT OF IFR AT OUR SRN TAF SITES W/ LESSER CHCS N. SHORT TERM: VFR GENERALLY EXPECTED INTO EARLY NEXT WEEK, BUT MVFR CONDITIONS WILL BE POSSIBLE IN MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS FRIDAY AND MONDAY. && .MARINE... NEAR TERM: LGT SE SWELL CURRENTLY RESULTING IN SEAS AROUND 4 FT... SEAS GENERALLY EXPECTED TO REMAIN IN THE 3-5 FT RANGE THRU TNGT IN CONTG LGT SE SWELL W/ MAINLY LGT (<15 KT SRLY WNDS). NO HEADLINES ANTICIPATED THRU TNGT W/ AREAS OF FOG CONTG MAINLY DURING THE ERLY EVE THRU MID AM HRS... SHORT TERM: A COLD FRONT WILL MOVE ACROSS THE WATERS LATE FRIDAY. AHEAD OF THIS FRONT, WAVES WILL APPROACH 5 FT AS SOUTH WINDS INCREASE. RIGHT NOW THINGS LOOK MARGINAL, BUT LATER SHIFTS WILL HAVE TO MONITOR TRENDS AS A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS MAY BE NECESSARY FRIDAY. WAVES WILL SUBSIDE FRIDAY NIGHT AND SATURDAY BEHIND THE FRONT; NO HEADLINES SHOULD BE NECESSARY THROUGH THE WEEKEND. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
941 AM EDT THU AUG 2 2012 .SYNOPSIS... A WEAKENING COLD FRONT WILL CROSS THE REGION THIS AFTERNOON. ANOTHER COLD FRONT WILL CROSS THE AREA ON FRIDAY. HIGH PRESSURE WILL RETURN FOR SATURDAY WITH PLEASANTLY WARM BUT LESS HUMID AIR. WARMER AND MORE HUMID CONDITIONS RETURN ON SUNDAY AHEAD OF ANOTHER COLD FRONT EXPECTED TO CROSS THE AREA ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE: NEEDED TO BOOST DEWPOINTS UP THROUGHOUT THE CWA BRINGING THEM INTO THE MID AND UPPER 60S BY THE AFTERNOON. LATEST SATL VISIBLE IMAGERY SHOWED STRATUS AND FOG BEGINNING TO ERODE THANKS TO DAYTIME HEATING. CLEARING ACROSS THE WEST AND NORTHWEST HAS LED TO TEMPERATURES RISING INTO THE LOWER 70S. THEREFORE, AFTERNOON HIGHS WERE RAISED AS WELL AS THIS CLEARING WILL WORK EAST ALLOWING FOR MORE SUNSHINE. DECIDED TO BRING MAXES UP TO AOA 80F ACROSS THE NORTHERN AND CENTRAL AREAS WHILE DOWNEAST AND THE COAST WILL BE COOLER THANKS IN PART TO THE ONSHORE FLOW(SSE WIND). WIDELY SCATTERED TSTMS EXPECTED THIS AFTERNOON RIGHT ALONG THE FRONT. LATEST HRRR SHOWED A LINE OF BROKEN CONVECTION SETTING UP THIS AFTERNOON BUT NOT SEVERE. IT LOOK LIKE ANY TSTMS WILL HAVE HEAVY RAIN AS WBZS ARE ABOVE 11K FT AND FORCING IN RATHER WEAK. THERE IS SOME LLVL CONVERGENCE SETTING UP AHEAD AND ALONG THE BOUNDARY AS IT MOVES THROUGH THIS AFTERNOON. THEREFORE, ADJUSTED POPS DOWN A BIT DUE TO THIS THINKING. PREVIOUS DISCUSSION... VERY WEAK FRONTAL BNDRY CURRENTLY JUST W AND NW OF THE AREA W/ A MILD AND RATHER HUMID LGT SRLY IN PLACE ACROSS OUR REGION AHEAD OF THIS SYSTEM... A FEW VRY LGT SHOWERS APPEAR TO BE LIFTING NE ACROSS THE FA PER RADAR THO NO RPTG STATIONS HAVE CARRIED ANY PRECIP LAST FEW HRS. EVEN AN ISOLD TSTM NOTED JUST W OF OUR BORDER ATTM - TO THE NW OF DAAQUAM. OTHER FEATURE OF INTEREST ERLY THIS AM IS ANOTHER LOW PRES SYSTEM WELL SW OF THEN AREA - JUST S OF THE CAPE... THE WEAK FRONTAL BNDRY WILL CONT TO SLOWLY CROSS THE AREA TDY W/ A BIT STRONGER FRONT ADVERTISED FOR FRI. LOW PRES WELL SW OF THE AREA SIMILAR TO THE SYSTEM THAT AFFECTED THE REGION YESTERDAY - THO WEAKER W/ THIS ONE EXPECTED TO TRACK A LITTLE FURTHER S AND E OF THE AREA. AS A RESULT...EXPECT PRECIP ASSOCIATED W/ THIS SYSTEM TO NOT BE A FACTOR... WILL CONT W/ PREVIOUS FCST THINKING AND WILL CARRY JUST CHC POPS TDY ACROSS THE FA AS UPPER SUPPORT W/ THIS SYSTEM APPEARS RELATIVELY WEAK. SYSTEM SUPPORTED SOME CONVECTION TO OUR W YESTERDAY AND W/ TDS IN THE 60S TDY...SFC HEATING SHOULD ALLOW FOR A THREAT OF THUNDER OUR AREA TDY AS WELL SPCLY DURING THE AFTN HRS. TEMPS EXPECTED TO WARM A FEW DEGREES OVER YESTERDAY W/ LOWS TNGT AGAIN SIMILAR TO THE LAST FEW NGTS. LATE NGT/ERLY AM LOW CIGS AND FOG A CONTG THREAT...SPCLY ACROSS THE SRN AREAS NEAR THE COAST. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... A COLD FRONT WILL MOVE ACROSS THE REGION ON FRIDAY, BRINGING THE CHANCES FOR SHOWERS AND THUNDERSTORMS TO MUCH OF THE STATE. AHEAD OF THE FRONT, SOUTH FLOW WILL KEEP MUGGY CONDITIONS AROUND AS DEWPOINTS REACH INTO THE LOWER AND MID 60S. HIGHS WILL RANGE FROM AROUND 80 IN THE SAINT JOHN VALLEY TO THE UPPER 80S ACROSS THE INTERIOR DOWNEAST. DRIER AIR WILL WORK INTO THE REGION BEHIND THE FRONT, LEADING TO A PLEASANT NIGHT FRIDAY NIGHT. HOWEVER, HUMIDITY WILL BEGIN TO MAKE ITS RETURN TO MAINE LATE SATURDAY AS THE COLD FRONT SLOWLY MOVES BACK NORTH AS A WARM FRONT. NORTHERN AREAS WILL SEE A NICE SUMMER DAY ON SATURDAY WITH HIGHS AROUND 80 AND LOW HUMIDITY. MEANWHILE, DOWNEAST MAINE WILL SEE A RETURN TO MUCH WARMER AND MUGGIER CONDITIONS; HIGHS WILL BE IN THE MID 80S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE WARM FRONT LIFTS ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY AS LOW PRESSURE MOVES EASTWARD THROUGH THE GREAT LAKES. THIS SYSTEM WILL MOVE NORTH OF THE FORECAST AREA SUNDAY NIGHT INTO MONDAY, DRAGGING ITS ATTENDANT COLD FRONT ACROSS NEW ENGLAND AS IT DOES SO. AS SUCH, THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE LATE SUNDAY, BUT ESPECIALLY LATE SUNDAY NIGHT INTO MONDAY. THIS FRONT WILL BE FOLLOWED BY A BRIEF RIDGE OF HIGH PRESSURE, BRINGING COOLER TEMPERATURES AND DRY WEATHER FOR MONDAY NIGHT AND TUESDAY. PRECIP CHANCES THEN INCREASE AGAIN BY MID WEEK AS ANOTHER FRONT MOVES INTO NORTHERN MAINE. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... NEAR TERM: CURRENTLY KBHB AND KBGR IFR W/ OUR REMAINING TAF SITES VFR... EXPECT SOME LOWER CIGS TO ARRIVE KHUL NEXT HR OR SO BUT AM NOT CONFIDENT THAT THESE CONDS WILL REACH OUR NRN TAF SITES ERLY THIS AM. FOR NOW WILL JUST ADVERTISE SOME MVFR UP N IN BR W/ CONFIDENCE LOW ATTM. MORE OF THE SAME TNGT W/ BEST THREAT OF IFR AT OUR SRN TAF SITES W/ LESSER CHCS N. SHORT TERM: VFR GENERALLY EXPECTED INTO EARLY NEXT WEEK, BUT MVFR CONDITIONS WILL BE POSSIBLE IN MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS FRIDAY AND MONDAY. && .MARINE... NEAR TERM: LGT SE SWELL CURRENTLY RESULTING IN SEAS AROUND 4 FT... SEAS GENERALLY EXPECTED TO REMAIN IN THE 3-5 FT RANGE THRU TNGT IN CONTG LGT SE SWELL W/ MAINLY LGT (<15 KT SRLY WNDS). NO HEADLINES ANTICIPATED THRU TNGT W/ AREAS OF FOG CONTG MAINLY DURING THE ERLY EVE THRU MID AM HRS... SHORT TERM: A COLD FRONT WILL MOVE ACROSS THE WATERS LATE FRIDAY. AHEAD OF THIS FRONT, WAVES WILL APPROACH 5 FT AS SOUTH WINDS INCREASE. RIGHT NOW THINGS LOOK MARGINAL, BUT LATER SHIFTS WILL HAVE TO MONITOR TRENDS AS A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS MAY BE NECESSARY FRIDAY. WAVES WILL SUBSIDE FRIDAY NIGHT AND SATURDAY BEHIND THE FRONT; NO HEADLINES SHOULD BE NECESSARY THROUGH THE WEEKEND. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT/KHW SHORT TERM...HASTINGS LONG TERM...HASTINGS AVIATION...HEWITT/KHW MARINE...HEWITT/KHW/HASTINGS
AREA FORECAST DISCUSSION
NWS GRAY ME
1211 AM EDT THU AUG 2 2012 .SYNOPSIS... LOW PRESSURE WILL TRACK EAST THROUGH THE SAINT LAWRENCE VALLEY TONIGHT... WITH A WEAK FRONT EXTENDING SOUTHWARD THROUGH NORTHERN NEW ENGLAND. ANOTHER LOW WILL TRACK THROUGH QUEBEC ON THURSDAY WITH A COLD FRONT PUSHING INTO THE AREA THURSDAY NIGHT AND FRIDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TODAY/... UPDATE... MINOR ADJUSTMENTS TO POPS AND QPF OVER THE NEXT FEW HRS. ONE CELL OVER N-CNTRL GRAFTON CO CONTS TO MOV E. THIS WILL SLOWLY DISSIPATE WITH TIME. OTRW...PATCHY FOG WILL CONT TO FORM OVERNIGHT AS DEW POINT VALUES REMAIN HIGH. REST OF FCST WILL REMAIN UNCHANGED AT THIS TIME. LATEST HRRR MODEL RUN HAS CONVECTION FIRING OVER THE NRN MTNS TODAY. TIMING APPEARS TO BE AROUND 1 PM AND THEREAFTER. PREVIOUS DISCUSSION... MAINE AND NEW HAMPSHIRE ARE CAUGHT BETWEEN TWO LOW PRESSURE SYSTEMS. THE FIRST MOVED THROUGH THE GULF OF MAINE AND INTO NOVA SCOTIA THIS MORNING... WHILE THE OTHER SPUN THROUGH THE SAINT LAWRENCE VALLEY. A WEAK TROUGH / COLD FRONT EXTENDS SOUTHWARD FROM THIS LOW ACROSS NEW HAMPSHIRE THIS AFTERNOON. THE COMBINATION OF LIFT FROM THE SHORTWAVE TROUGH ALOFT... WEAK CONVERGENCE AT THE SURFACE... AND MOIST AIR IN PLACE GENERATING WEAK INSTABILITY THIS AFTERNOON WILL LEAD TO A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS THROUGH EARLY EVENING. THESE SHOULD DISSIPATE IN LARGE PART AFTER SUNSET... BUT FURTHER NORTH CLOSER TO THE SURFACE LOW AND COLD CORE ALOFT... SHOWERS MAY CONTINUE INTO THE NIGHT. WITH A LOT OF MOISTURE AROUND... DEW POINTS IN THE MID 60S... FOG IS POSSIBLE TONIGHT. HOWEVER... EXPECT A LOT OF CLOUD COVER OVERNIGHT AFTER CONVECTION DEVELOPS AND IN ASSOCIATION WITH LIFT FROM THE SHORTWAVE TROUGH. THIS MAY LIMIT THE FOG POTENTIAL SOMEWHAT OVERNIGHT. TEMPERATURES STAY IN THE 60S OVERNIGHT DUE TO ALL THE MOISTURE IN PLACE. && .SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/... INITIAL SHORTWAVE TROUGH AXIS STILL LINGERS ACROSS THE AREA THROUGH THURSDAY. LIFT AHEAD OF THIS FEATURE WILL EXIST ESPECIALLY ACROSS MUCH OF MAINE AND COASTAL AREAS. THIS... IN COMBINATION WITH LOW LEVEL MOISTURE AND INSTABILITY... MAY LEAD TO SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THE COASTAL PLAIN BY LATE MORNING. SURFACE BASED CAPE INDICATED BY THE NAM MODEL EXCEEDS 1200 AND WOULD BE ENOUGH FOR THUNDERSTORMS. SUBSIDENCE BEHIND THE SHORTWAVE TROUGH AXIS OVER NEW HAMPSHIRE SHOULD LIMIT SHOWER AND THUNDERSTORM COVERAGE HERE. FOR NOW HAVE INDICATED A CHANCE OF SHOWERS AND THUNDERSTORMS IN THIS AREA... WITH HIGHS IN THE 80S. ANOTHER SHORTWAVE TROUGH CROSSES THROUGH SOUTHERN CANADA... WITH A COLD FRONT PUSHING SOUTH TOWARD THE INTERNATIONAL BORDER THURSDAY NIGHT. COULD BE MORE SHOWER ACTIVITY PUSHING SOUTHWARD WITH THIS BY EARLY FRIDAY MORNING. MAY BE A BETTER POTENTIAL FOR FOG THURSDAY NIGHT AS MOISTURE LEVELS REMAIN HIGH AND SKY WILL BE MORE CLEAR AS DAYTIME SHOWERS DISSIPATE. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... A WEAK COLD FRONT WILL SLOWLY PUSH ACROSS THE AREA ON FRIDAY...BUT FORCING IS QUITE WEAK...SO ONLY EXPECTING A FEW ISOLATED SHOWERS AND THUNDERSTORMS AS IT MEANDERS TO THE SOUTHEAST. A WEAK HIGH PRESSURE WILL BUILD IN BEHIND THE FOR THE WEEKEND...BUT A MUCH STRONGER COLD FRONT WILL MOVE IN FROM THE GREAT LAKES LATE SUNDAY. THERE IS SOME TIMING DIFFERENCES BETWEEN THE EURO AND GFS...WITH THE GFS DRAGGING THE FRONT ACROSS SUNDAY NIGHT INTO MONDAY MORNING...WHILE THE EURO BRINGS IT THROUGH EARLY MONDAY AFTERNOON. THE EUROS PASSAGE WILL MIRROR PEAK HEATING ON MONDAY. THIS SCENARIO...WITH A DECENT THERMODYNAMIC ENVIRONMENT...WILL GIVE US A GOOD CHANCE FOR THUNDERSTORM DEVELOPMENT BY MIDDAY MONDAY. WITH THE CURRENT UNCERTAINTY...STILL JUST LEAVING THINGS AS A CHANCE OF THUNDERSTORMS. AFTER THE FRONT PASSES...HIGH PRESSURE WILL BUILD IN AND KEEP THINGS QUIET THROUGH WEDNESDAY. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... SHORT TERM...EXPECTING MOSTLY VFR CONDITIONS AND LIGHT SOUTH TO SOUTHWESTERLY WINDS... BUT MVFR IN SHOWERS THIS EVENING IS POSSIBLE. BEST CHANCE OF THUNDER WILL BE OVER NEW HAMPSHIRE... AND IN PARTICULAR NORTHERN NEW HAMPSHIRE CLOSER TO THE SHORTWAVE TROUGH ALOFT. THERE IS THE POTENTIAL FOR NOCTURNAL FOG OVERNIGHT AS LOW LEVEL MOISTURE IS HIGH. HOWEVER... CLOUD COVER MAY BE TOO EXTENSIVE FOR FOG FORMATION AND CONFIDENCE IN FOG CAUSING REDUCED VISIBILITIES TONIGHT IS DECREASING. ON THURSDAY THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL PLAIN... WITH A BETTER CHANCE OF FOG THURSDAY NIGHT. LONG TERM... FRONTAL BOUNDARY COMING THROUGH ON MONDAY COULD DROP CIGS/VIS TO IFR/MVFR. && .MARINE... SHORT TERM...LIGHT SOUTH TO SOUTHWEST FLOW EXPECTED OVER THE WATERS TONIGHT AND TOMORROW. SEAS WILL SLOWLY SUBSIDE. LONG TERM... SCA CRITERIA MAY BE MET LATE SUNDAY INTO MONDAY AS A FRONTAL BOUNDARY APPROACHES THE AREA. && .EQUIPMENT... DUAL POLARIZATION UPGRADE OF THE GYX RADAR HAS BEEN COMPLETED. RADAR DATA IS NOW FLOWING THROUGH NORMAL CHANNELS. COMMUNICATIONS WITH KRKD SEEM TO HAVE BEEN RESTORED AGAIN. ISSUE MAY NOT BE PERMANENTLY RESOLVED. AS OBSERVATIONS CONTINUE TO COME IN THROUGH NORMAL CHANNELS THE TAF WILL BE PRODUCED AS NORMAL. HOWEVER... IF OBSERVATIONS DROP OUT AGAIN THEN THE "AMD NOT SKED" REMARK MAY HAVE TO BE ADDED AGAIN. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ JC
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
923 PM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL CROSS THE GREAT LAKES SUNDAY...BEFORE MOVING THROUGH SUNDAY NIGHT. WEAK HIGH PRESSURE WILL MOVE OVER THE MID-ATLANTIC REGION FOR THE FIRST PART OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... SIMILAR TO LAST EVENING...MOST OF THE SHOWERS AND THUNDERSTORMS HAVE DISSIPATED WITH THE SETTING OF THE SUN BUT A COUPLE OF ISOLATED CELLS REMAIN AT 01Z. THESE WILL LIKELY ALSO DISSIPATE WITHIN THE NEXT COUPLE OF HOURS ALTHOUGH THE HRRR SUGGESTS THAT AN ISOLATED SHOWER STILL CAN/T BE RULED OUT TOWARD THE HIGHLANDS/SHENANDOAH VALLEY AREA OVERNIGHT. MID-CLOUDS MAY THIN OUT/SCATTER OVERNIGHT...SO PATCHY FOG MAY ALSO FORM LATER TONIGHT. TMRW WL BE A TYPICAL ERLY AUG DAY..IN FACT QUITE A BIT LK TDA. LGT FOG WL BECOME HZ...HZ WL BECOME AFTN CU. ONCE AGN THE MTNS WL BE THE BEST PLACE FOR AFTN CNVCTN TO FORM. HIGH TEMPS AGN XPCTD TO RANGE FM THE U80S TO THE M90S. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... DIURNAL CONVECTION ON SAT WILL WANE DURING THE EVE WITH THE LOSS OF DAYTIME HEATING. SAT NGT WILL BE MUGGY...WITH MIN TEMPS RANGING FROM THE MID 60S IN THE HIGHLANDS TO MID 70S ALONG AND EAST OF I-95. SHORTWAVE TROUGH OVER THE UPPER MIDWEST ERY SUN IS FCST TO LIFT NEWD ACROSS THE GREAT LAKES DURING THE DAY. THIS SHORTWAVE ENERGY WILL BE WEAKENING DURING THIS TIME AS THE UPPER-JET STREAK AHEAD OF THE TROUGH LIFTS NEWD INTO ERN CANADA. THE MID- ATLANTIC REGION WILL BE SITUATED IN THE PRE- FRONTAL WARM- MOIST SECTOR ON SUN AS A SFC COLD FRONT MOVES INTO THE OH VLY. AFTN TEMPS IN THE LOWER 90S AND DEWPOINTS IN LOWER 70S ON SUN WILL YIELD A MODERATE AMT OF INSTABILITY...AROUND 1.5-2 KJ/KG...BY THE AFTN. COVERAGE AND ORGANIZATION OF CONVECTION SHOULD BE BETTER NORTH AND WEST OF THE REGION...WHERE THE BEST SYNOPTIC LIFT ASSOCIATED WITH THE TROUGH/COLD FRONT RESIDE. GIVEN THE STEEP LLVL LAPSE RATES AND APPROACH OF A 30-KT LLVL JET BY EVE...A FEW STORMS MAY BECOME SEVERE DURING THE PEAK HEATING HRS. COLD FRONT WILL MOVE THRU SUN NGT. IF FRONT MOVES THRU EARLIER THAN 12Z MODELS INDICATE...THEN ORGANIZED CONVECTION AND A DAMAGING WIND THREAT MAY EXTEND EWD TOWARD THE WRN TERRAIN AND NRN MD DURING THE EVE. HOWEVER...ATMOSPHERE WILL BE LESS CONDUCIVE FOR SEVERE WEATHER FARTHER SOUTH AND EAST WHEN FRONT MOVES THRU SEVERAL HRS AFTER SUNSET. && .LONG TERM /MONDAY THROUGH FRIDAY/... AN UPPER-LEVEL TROUGH MOVES OVER THE REGION NEXT WEEK WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPS EXPECTED FOR EARLY AUGUST. THE SURFACE COLD FRONT THAT IS EXPECTED TO MOVE THROUGH THE REGION MONDAY SHOULD STALL TO THE SOUTH AS A BERMUDA HIGH PERSISTS IN THE ATLANTIC. LIFT ASSOCIATED WITH THE FRONT MAY PRODUCE SHOWERS AND THUNDERSTORMS BUT ACTIVITY SHOULD TO THE SOUTH THROUGH THE PERIOD. GFS AND ECMWF BRING FRONT NORTHWARD ON WEDNESDAY WHICH MAY PRODUCE SHOWERS AND THUNDERSTORMS ESPECIALLY FOR THE SOUTHERN HALF OF THE CWA. TROUGH WILL EVENUTALLY FLATTEN AND MOVE EASTWARD TOWARD THE END OF NEXT WEEK BEFORE THE NEXT WAVE ARRIVES NEXT FRIDAY. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... EXCEPT FOR A STRAY SHOWER...AREA SHOULD BE DRY OVERNIGHT. LIKE LAST NIGHT...SOME FOG MAY FORM AT MRB/CHO/IAD. MRB WENT DOWN TO IFR LAST NIGHT...AND LEANED TOWARD PERSISTENCE. CHO RECEIVED RAIN THIS EVENING...SO IFR MAY BE MORE LIKELY LATE TONIGHT. KEPT IAD IN MVFR TOWARD SUNRISE. VFR WILL PREVAIL FOR SATURDAY...BUT WILL HAVE TO WATCH SCATTERED THUNDERSTORMS POPPING UP IN THE AFTERNOON. A COLD FRONT WILL APPROACH FROM THE NW SUN. SCT STORMS AHEAD OF THE FRONT SUN AFTN WILL INCREASE IN COVERAGE LATE IN THE DAY AND AT NGT AS THE COLD FRONT MOVES THRU. TEMPORARY RESTRICTIONS EXPECTED IN STORMS. VSBY RESTRICTIONS POSSIBLE IN FOG LATE SUN NGT...ESPECIALLY AT TERMINALS THAT WERE IMPACTED BY EARLIER STORMS. AS FRONT LINGERS TO THE SOUTH...VFR CONDITION EXPECTED MOST OF THE TIME. SHOWERS AND THUNDERSTORMS MAY CAUSE BRIEF PERIODS OF REDUCED VISBYS MAINLY FOR CHO TOWARDS THE END OF NEXT WEEK. LIGHT S-SW FLOW EXPECTED THROUGH THE PERIOD. && .MARINE... RISK OF THUNDERSTORMS HAS DIMINISHED OVER THE WATERS OVERNIGHT. SOUTHERLY FLOW WILL CHANNEL UP THE BAY...PRODUCING UP TO 15 KT AT TIMES WITHIN THE MAIN CHANNEL. SCATTERED THUNDERSTORMS MAY PRODUCE GUSTY WINDS SATURDAY AFTERNOON. SCA HAS BEEN ISSUED FOR SAT NGT FOR THE MOUTH OF THE TIDAL POTOMAC RVR AND SRN ZONES OF THE MD CHSPK BAY...WHERE SLY CHANNELING WILL PRODUCE 20-KT GUSTS. SCA CONDITIONS POSSIBLE FOR MOST MARINE ZONES AS SLY WINDS INCREASE AHEAD OF A COLD FRONT. A FEW STORMS AHEAD OF THE FRONT COULD PRODUCE GUSTY WINDS LATE SUN. AS FRONT LINGERS SOUTH OF THE WATERS NEXT WEEK...LIGHT SOUTHWESTERLY FLOW EXPECTED. && .TIDES/COASTAL FLOODING... WILL HAVE TO WATCH SENSITIVE AREAS SUCH AS ALEXANDRIA AND ANNAPOLIS AGAIN DURING HIGH TIDE SATURDAY MORNING. IT WOULD TAKE AN ANOMALY OF AROUND 0.8 TO HIT MINOR TIDAL FLOODING THRESHOLDS AT ANNAPOLIS. ANOMALY IS AROUND 0.6. THIS HAS BEEN FAIRLY STEADY THUS FAR. WITH SOUTHERLY WINDS...THERE IS THE CHANCE THIS COULD CREEP UP A LITTLE MORE...BUT DON/T HAVE THE CONFIDENCE IN HITTING CRITERIA ATTM. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 PM SATURDAY TO 6 AM EDT SUNDAY FOR ANZ533-534-537-541-543. && $$ BPP/WOODY!/KLEIN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 AM EDT THU AUG 2 2012 .UPDATE... ISSUED AT 934 PM EDT WED AUG 1 2012 CONVECTIVE TRENDS MAIN ISSUE FOR THE LATE EVENING AND OVERNIGHT. LOW PRESSURE OVR NORTH END OF LK SUPERIOR WHILE COLD FRONT IS CLOSING IN ON FAR WESTERN UPR MICHIGAN. THERE ARE TWO MAIN SHORTWAVE TROUGHS OVR THE REGION. FIRST WAVE IS PUSHING ACROSS EASTERN LK SUPERIOR AND COMBINED WITH H85 THETA-E ADVECTION HAS DRIVEN SHRA/TSRA THAT HAVE BEEN ROAMING OVER EASTERN LK SUPERIOR AND FAR EASTERN CWA THIS EVENING. SECOND WAVE IS PUSHING INTO WESTERN MINNESOTA AND HAS KICKED OFF COMPLEX OF STRONG TSRA OVER SW MINNESOTA. ANOTHER WAVE IS UPSTREAM OVR SOUTHERN MANITOBA AND MAY HAVE AFFECT ON WX LATER TONIGHT. CONVECTION OVR WEST HALF OF UPR MICHIGAN PRETTY MUCH NIL THIS EVENING DESPITE HIGHER INSTABILITY /MLCAPES UPWARDS OF 2000 J/KG AND APPROACHING COLD FRONT. MAIN REASON FOR MINIMAL CONVECTION IS PROBABLY LARGE AREA OF MINIMUM H7 DWPNT...WHICH IS LIKELY EXTENDING LOWER INTO THE LOWER LAYERS OF THE ATMOSPHERE. RUC INDICATES INCREASE OF H7 MOISTURE AFT MIDNIGHT AS THE COLD FRONT PUSHES INTO CNTRL UPR MICHIGAN. THE INCREASED MOISTURE H85-H7 MOISTURE ADVECTION INTO THE FRONT IN PRESENSE OF THE UPSTREAM SHORTWAVE OVR MANITOBA COULD BE ENOUGH TO TRIGGER SHRA/TSRA OVERNIGHT MAINLY OVER THE SOUTH INTO THE EASTERN CWA. STILL A RISK OF ISOLD STRONGER STORMS AS INSTIBILITY AND SHEAR REMAIN MORE THAN SUFFICIENT. AFTER LATE TONIGHT...GOING FLAVOR OF PREVIOUS FCST STILL THERE WITH COLD FRONT STALLING OUT OVR SOUTH CENTRAL CWA ON THURSDAY. POPS REMAIN SLIGHT CHANCE FOR NOW FOR THIS...BUT MAY NEED INCREASING LATER TONIGHT ONCE NEXT UPSTREAM WAVE IS SORTED OUT. ONLY CHANGE OF NOTE FOR FCST WAS TO RESTRUCTURE POPS THROUGH THE OVERNIGHT BASED ON LATEST MESOANALYSIS/RADAR TRENDS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 327 PM EDT WED AUG 1 2012 A 1002MB SFC LOW IS CENTERED JUST NW OF LAKE SUPERIOR WITH AN ASSOCIATED MID/UPPER LEVEL SHORTWAVE OVERHEAD. A SFC COLD FRONT IS CURRENTLY STRETCHED FROM THE SFC LOW SW TO FAR NRN MN. ANOTHER SHORTWAVE RIDING OVER THE UPPER RIDGE OVER THE WRN CONUS WAS LOCATED JUST N OF LAKE SUPERIOR AT 14Z TODAY...CAUSING THUNDERSTORMS TO MOVE N OF LAKE SUPERIOR. ANOTHER CLUSTER OF THUNDERSTORMS WAS OVER ERN MN LATE THIS MORNING...WHERE MORE MOISTURE WAS PRESENT. BY AROUND 17Z TODAY...THE STORMS MADE THEIR WAY INTO FAR WRN UPPER MI NEAR IWD...AND ARE NOW /19Z/ LOCATED OVER WRN IRON/SRN HOUGHTON COUNTIES. A COUPLE OF THE STORMS WERE STRONGER NEAR IWD...AND A COUPLE WERE SEVERE JUST S OF GOGEBIC COUNTY. CLEARING BEHIND THESE STORMS...ALONG WITH ALREADY HIGH SFC DEW PTS...MAY LEAD TO INCREASED INSTABILITY OVER FAR WRN UPPER MI LATE THIS AFTERNOON. THERE IS A RISK FOR SOME STRONGER THUNDERSTORMS OVER THE FAR W INTO THIS EVENING. DRY AIR OVER THE AREA HAS LEAD TO LARGE DCAPES...SO STRONG WINDS WOULD BE A THREAT WITH ANY SIGNIFICANT CONVECTION. MLCAPES UP TO 2000J/KG WILL BE POSSIBLE WITH 0-6KM SHEAR OF 30-40KTS...ALSO LEADING TO A HAIL THREAT. MODEL QPF VARIES WIDELY FROM MODEL TO MODEL...FURTHER LIMITING CONFIDENCE IN COVERAGE THIS EVENING THROUGH TONIGHT. OVERALL...BEST CHANCES FOR CONVECTION WILL BE THIS AFTERNOON INTO THIS EVENING ALONG THE WI BORDER OVER THE W. 850MB TEMPS TODAY WERE AROUND 20C...BUT NW WINDS BEHIND THE COLD FRONT TOMORROW WILL KEEP 850MB TEMPS AROUND 15C S TO 11C N...SO TEMPS WILL QUITE A BIT COOLER /ESPECIALLY NEAR LAKE SUPERIOR/. THIS WILL LEAD TO HIGHS IN THE 70S N TO 80S S. SINCE THE COLD FRONT LOOKS TO BE S OF THE CWA BY 12Z THU...WILL CUT BACK POPS FROM PREVIOUS SHIFT. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 327 PM EDT WED AUG 1 2012 HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES...BEHIND THE COLD FRONT WHICH WILL BE MOVING ACROSS THE LOWER GREAT LAKES AND NEW ENGLAND STATES. WHILE THE CENTER OF THE SFC LOW WILL REMAIN TO OUR NE...LIGHT WINDS WILL PREVAIL...WITH SOME RETURN FLOW OVER THE W HALF CLOSER TO THE NEARING SFC LOW OVER THE PLAINS STATES THROUGH MANITOBA. NORTHWEST FLOW WILL CONTINUE ALOFT THURSDAY NIGHT...WITH THE MAIN 500MB LOW STILL SPINNING OVER NE HUDSON BAY/N QUEBEC...AND THE NEXT LOW PUSHING ACROSS THE PACIFIC NW/SW CANADA. SLIGHT RIDGING TO ZONAL FLOW FRIDAY...OUT AS THE WESTERN 500MB LOW DIGS ACROSS THE DAKOTAS. THE LOW WILL CONTINUE TO DEEPEN AS IT SHIFTS ACROSS N MN/W ONTARIO BY 18Z SATURDAY. THE GFS/CANADIAN ARE MORE PROGRESSIVE WITH THE 500MB LOW /NEAR JAMES BAY/...WHILE THE ECMWF IS STILL OVER N LS AND CENTRAL ONTARIO. WINDS JUST ABOVE THE SFC FRIDAY NIGHT COULD BE QUITE STRONG...WITH NEARLY UNIDIRECTIONAL SW WINDS OF 30-40KTS AT AND ABOVE 925MB. SOME DRY AIR AT THE SFC INITIALLY SHOULD PRECLUDE STRONG TS DEVELOPMENT...BUT COULD DEPEND ON THE LOCATION OF THE WARM FRONT. MLCAPE VALUES JUMP TO 500-1100J/KG OVER THE W LAND AWAY FROM THE KEWEENAW PENINUSLA BY 12Z SATURDAY...WITH 45-55KT LLJ OVER THE ENTIRE W HALF. THIS STRONG WAA SHOULD KEEP TEMPS FROM FALLING MUCH BELOW 65F...PARTICULARLY OVER THE W HALF DOWNSLOPE LOCATIONS NEAR LS. 850MB TEMPS JUMP TO AROUND 18C SATURDAY AFTERNOON CWA WIDE UNTIL THE PASSAGE OF THE COLD FRONT BY MID/LATE AFTERNOON W. NO MATTER WHICH SOLUTION PANS OUT ALOFT...NW FLOW WILL RETURN BY SUNDAY NIGHT THROUGH MID DAY TUESDAY. LINGERING CLOUDS ON FAVORABLE NW WINDS AND 850MB TEMPS OF 7-8C SHOULD KEEP A FEW CLOUDS SET UP N CENTRAL AND E SUNDAY MORNING. A FEW DIFFICULT TO PREDICT SHORTWAVES LOOK TO SWING THROUGH OR TO OUR N IN THE FAST NW FLOW. THE LARGE SCALE TROUGH SET UP FROM CENTRAL CANADA THROUGH THE MID ATLANTIC WILL BRING MORE ZONAL FLOW TO THE UPPER GREAT LAKES ON WEDNESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 134 AM EDT THU AUG 2 2012 A LOW PRESSURE SYSTEM CROSSING NORTHERN PORTIONS OF LAKE SUPERIOR WILL PUSH A COLD FRONT ACROSS UPR MICHIGAN BY DAYBREAK THIS MORNING. STILL SOME CONCERN THAT ISOLD SHRA/TSRA COULD AFFECT TAF SITES EARLY THIS MORNING. AT THIS POINT...BEST CHANCE WOULD PROBABLY BE AT SAW BEFORE SUNRISE AS COLD FRONT APPROACHES AND ADDITIONAL SUPPORT IS PROVIDED BY UPPER LEVEL DISTURBANCE. ANY RISK OF SHRA/TSRA WILL BE OUT OF THE TAF SITES BY MID MORNING AT THE LATEST. ATTN REST OF THE DAY WILL BE ON POST-FRONTAL LOWER CLOUDS. BASED ON UPSTREAM CIGS IN MANITOBA AND ONTARIO LAST EVENING AND EARLY THIS MORNING...SCT-BKN STRATOCU CLOUDS ARE EXPECTED...ESPECIALLY GIVEN DEVELOPING NORTHERLY WINDS OFF LK SUPERIOR. AFTER A PERIOD OF LOWER CIGS IN THE MVFR RANGE...EXPECT SKIES TO SCATTER OUT MID-LATE AFTERNOON AS HIGH PRESSURE BUILDS INTO THE AREA. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 327 PM EDT WED AUG 1 2012 A LOW PRESSURE SYSTEM MOVING THROUGH SOUTHERN CANADA TODAY AND TONIGHT WILL SWEEP A COLD FRONT ACROSS LAKE SUPERIOR. EXPECT SW WINDS AHEAD OF THIS FRONT TO GUST TO 20KTS BEFORE SHIFTING TO THE NW TO 20KTS OVERNIGHT. A HIGH PRESSURE RIDGE WILL THEN SETTLE BACK OVER LAKE SUPERIOR THURS INTO FRI. A STRONGER LOW PRESSURE SYSTEM DEVELOPING NEAR LAKE WINNIPEG ON FRIDAY WILL SHIFT ENE TO JAMES BAY BY SUNDAY MORNING AND SWEEP A COLD FRONT ACROSS LAKE SUPERIOR ON SATURDAY. WINDS COULD GUST TO 25KTS THIS WEEKEND AS THE SYSTEM MOVES THROUGH. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...JLA SHORT TERM...TITUS LONG TERM...KF AVIATION...JLA MARINE...TITUS
AREA FORECAST DISCUSSION
NWS DULUTH MN
1222 AM CDT THU AUG 2 2012 .AVIATION.../06Z TAF ISSUANCE/ SHOWERS OVER THE SOUTHERN TERMINALS WILL MOVE OUT OF BRD BY 07Z AND 09Z AT HYR. SHOWERS NORTH OF INL WILL MOVE AWAY BY 07Z. SKIES WILL PARTIALLY CLEAR BY DAYBREAK WHICH MAY LEAD TO A FEW FOG PATCHES. HAVE TEMPO GROUPS FOR VISIBILITIES BETWEEN 3SM AND 5SM TO ACCOUNT FOR THIS. VFR CONDITIONS WILL PREVAIL THROUGH THE DAYLIGHT HOURS ON WEDNESDAY WITH NORTHWESTERLY WINDS UNDER 10 KNOTS. && .PREV DISCUSSION... /ISSUED 740 PM CDT WED AUG 1 2012/ SHORT TERM... CURRENTLY...NO THUNDERSTORMS WERE OCCURRING OVER THE CWA. WE HAD A BRIEF STORM DEVELOP OVER SOUTHERN PINE COUNTY AROUND 2330Z IN AN AREA OF ENHANCED CU THAT HAS BEEN MOVING EAST OVER THE PAST COUPLE HOURS. STABILITY IS IMPRESSIVE THIS EVENING...WITH MUCAPE AROUND 3000J/KG OVER NORTHWEST WISCONSIN...TO A 1000 J/KG OVER THE INTERNATIONAL BORDER REGION. HOWEVER...LIFT IS QUITE MARGINAL WITH MID LEVEL ENERGY FURTHER NORTH AND WEST PASSING THROUGH SOUTHERN MANITOBA...AND STRONGER LOW LEVEL FGEN FORCING FURTHER SOUTH OVER SOUTHERN MINNESOTA INTO SOUTH DAKOTA. THERE IS SOME WEAK LOW LEVEL CONVERGENCE...SEEN IN THE SURFACE OBS...WITH W-NW FLOW AT KRZN/KDLH/K04W AND LIGHT SW FLOW AT KPBH AND KASX. THE RAP SHOWS LITTLE 925MB CONVERGENCE. WE CAN`T RULE OUT A THUNDERSTORM OVER THE NEXT FEW HOURS OVER NORTHWEST WISCONSIN AS THE WEAK LOW LEVEL CONVERGENCE MOVES THROUGH. WE ALSO COULD GET BRUSHED WITH THE COMPLEX OF STORMS THAT WERE AFFECTING SOUTHERN/CENTRAL MN AND SOUTH DAKOTA AS IT CONTINUES E-SE. HOWEVER...CHANCES OF THAT ARE LOW. FURTHER NORTH...A SHORTWAVE SEEN ON SATELLITE AND IN THE RAP`S 1.5 PV SURFACE...WILL AFFECT FAR NORTHERN MINNESOTA AND COULD BRING A FEW SHOWER OR STORMS TO THAT AREA LATER THIS EVENING. WE MAY HAVE TO EXTEND AND EVEN INCREASE POPS A BIT AFTER 03Z IN THE FAR NORTH. PREV DISCUSSION... /ISSUED 626 PM CDT WED AUG 1 2012/ AVIATION.../0Z TAF ISSUANCE/ COLD FRONT HAS MOVED THROUGH THE TERMINALS WITH NORTHWESTERLY WINDS. MAIN AREA OF SHOWER AND THUNDERSTORM ACTIVITY WILL STAY TO OUR SOUTH. HAVE INCLUDED SOME TEMPO GROUPS TO ACCOUNT FOR THE DEVELOPMENT OF PATCHY FOG BEFORE DAWN. VISIBILITIES MAY FALL TO 1SM AT HIB...DLH...AND HYR. WINDS WILL STAY LIGHT NORTHWESTERLY THROUGH THE TAF FORECAST PERIOD. PREV DISCUSSION... /ISSUED ISSUED BY NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN/ DISCUSSION... PRIMARY FORECAST CONCERNS ARE CHANCES FOR TSRA THIS LATE THIS AFTERNOON INTO THIS EVENING AS THE COLD FRONT MOVES THROUGH THE REMAINDER OF THE AREA... THEN CHANCES FOR MORE WIDESPREAD SHRA/TSRA FRIDAY NIGHT INTO SATURDAY MORNING AS THE NEXT SHORTWAVE AND COLD FRONT MOVE THROUGH THE AREA. LATEST WATER VAPOR IMAGERY SHOWS THE SAME BASIC UPPER AIR PATTERN WE/VE SEEN FOR MUCH OF THE SUMMER... WITH A BROAD UPPER RIDGE ENCOMPASSING MOST OF THE CENTRAL CONUS. THE SHORTWAVE CURRENTLY RIDING ALONG THE US/CANADIAN BORDER NEAR THE MONTANA/NORTH DAKOTA BORDER WILL CONTINUE TO DRIVE EAST TONIGHT... HELPING TO FINALLY PUSH THE COLD FRONT CURRENTLY OVER MINNESOTA EAST THROUGH THE REMAINDER OF THE AREA. SPC MESOANALYSIS SHOWS GOOD INSTABILITY ALONG AHEAD OF THE FRONT... WITH MLCAPE AOA 2500 J/KG. SOME INSTABILITY LAGS THE SURFACE BOUNDARY AS WELL... WHICH IS HELPING TO KEEP ACTIVITY GOING TO THE WEST... AND NECESSITATES LEAVING POPS IN THE FORECAST ACROSS THE AREA THROUGH AT LEAST EARLY EVENING AS THE UPPER WAVE MOVES TOWARD THE FORECAST AREA. WE SHOULD MANAGE TO CLEAR THE PCPN OUT OF ALL BUT PERHAPS THE SOUTHEAST PORTION OF THE AREA OVERNIGHT AS THE FRONT CONTINUES EAST AND A WEAK SURFACE RIDGE TRIES TO WORK INTO THE AREA. THERE COULD BE SOME AREAS OF FOG LATE TONIGHT WITH WINDS DYING AND CLOUD COVER DECREASING... BUT THAT WILL LIKELY DEPEND ON ANY RE-WETTING OF THE GROUND WHICH CAN OCCUR WITH PCPN THROUGH EARLY THIS EVENING... SO OPTED TO LEAVE IT OUT OF THE FORECAST FOR NOW. IT SHOULD BE PARTLY CLOUDY AND DRY OVER MOST OF THE AREA ON THURSDAY AS THE SURFACE HIGH DRIFTS ACROSS THE AREA. HOWEVER... THE ARROWHEAD COULD SEE SOME AFTERNOON PCPN DEVELOP GIVEN BETTER PROXIMITY TO THE MID-LEVEL COLD POOL MOVING NORTH AND NORTHEAST OF THE AREA DURING THE DAY. AFTER TOMORROW ATTENTION WILL TURN TOWARD THE SHORTWAVE CURRENTLY DROPPING THROUGH BRITISH COLUMBIA. THIS WAVE IS EXPECTED TO CONTINUE EAST-SOUTHEAST THROUGH THE NEXT FEW DAYS... WORKING INTO THE HIGH PLAINS BY FRIDAY... THEN CONTINUING EAST ACROSS THE FORECAST AREA SATURDAY INTO SUNDAY. DECENT RETURN FLOW AND WARM ADVECTION IS EXPECTED AHEAD OF THIS FEATURE... AND THE NAM... GFS... AND ECMWF ARE ARE IN REASONABLY AGREEMENT ON THE DEGREE OF INSTABILITY AND FORCING ASSOCIATED WITH ITS PASSAGE. THERE ARE STILL SOME TIMING DIFFERENCES... WHICH RESULT IN HAVING A LONGER PERIOD BLANKETED WITH POPS THAN WILL LIKELY OCCUR... BUT AS THINGS GET CLOSER IN TIME THOSE WILL BE REFINED AND LIKELY INCREASED FOR THE FROPA AND SHORTWAVE ARRIVAL WHICH CURRENTLY LOOKS TO OCCUR FRIDAY NIGHT INTO SATURDAY MORNING. INCLUDED CHANCE-LIKELY POPS WITH THIS SYSTEM FRIDAY NIGHT INTO SATURDAY... THEN TAPERED THING BACK SATURDAY NIGHT AS THE FRONT MOVES WELL TO THE EAST BUT CYCLONIC BOUNDARY LAYER FLOW AND AND MID-UPPER COLD POOL LINGER OVER THE AREA. IMPRESSIVE RIDGING LOOKS TO ARRIVE AND KEEP THINGS BENIGN SUNDAY THROUGH MONDAY... WITH A SMALL CHANCE FOR SOME PCPN MONDAY NIGHT AS A WEAK FRONTAL BOUNDARY DROPS SOUTH THROUGH THE AREA. THE MAIN CHANCES LOOK TO BE OVER THE SOUTHERN PORTION OF THE AREA WITH THAT FEATURE... SINCE IT APPEARS IT WILL TAKE A WHILE FOR THINGS TO SATURATE IF THEY DO AT ALL GIVEN THE DRYNESS OF THE ANTECEDENT AIRMASS. PCPN CHANCES SHOULD RETURN BY THE MIDDLE OF THE WEEK AS WE GET ONTO THE BACKSIDE OF THE SURFACE HIGH AND A FEW SHORTWAVES DROP SOUTHEAST INTO THE AREA ON THE PREVAILING NORTHWEST FLOW. && .POINT TEMPS/POPS... DLH 64 79 60 77 / 20 10 10 30 INL 60 79 60 78 / 30 10 20 50 BRD 63 84 62 84 / 30 10 10 50 HYR 65 82 60 82 / 30 10 10 20 ASX 68 77 61 78 / 20 10 0 20 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ AVIATION...KK
AREA FORECAST DISCUSSION
NWS GLASGOW MT
945 PM MDT FRI AUG 3 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY... PREVIOUS DISCUSSION...GOING FORECAST IN OVERALL GOOD SHAPE. SHOWERS CONTINUE TO STREAM INTO THE NORTHERN ZONES...DRIVEN BY A LARGE UPPER LOW. HRRR MODEL SEEMS TO BE DOING A GOOD JOB WITH THE CURRENT PATTERN...THUS FAVORED IT FOR THE UPDATE. BIGGEST CHANGES WERE TO DECREASE POPS ACROSS THE SOUTH AND TO INCREASE SHOWER COVERAGE ACROSS THE NORTHEAST. WINDS HAVE ALSO DECREASED REGION WIDE...THUS THE LAKE WIND ADVISORY WAS CANCELLED EARLY. GILCHRIST A LARGE MIDLEVEL LOW IS CURRENTLY SPINNING OVER NORTHEAST MONTANA. THIS SYSTEM PULLED A COLD FRONT THROUGH YESTERDAY AND BROUGHT WIDESPREAD SHOWERS AND CLOUD COVER TO THE REGION. WITH CLOUD COVER AND RAIN ACTIVITY...HIGH TEMPERATURES HAVE NOT BEEN REACHING FORECAST VALUES...EXCEPT IN THOSE AREAS WHICH SAW BREAKS IN THE OVERCAST. SOME THUNDERSHOWER ACTIVITY HAS ALSO BEEN NOTED OVER PHILLIPS COUNTY WHICH SAW SOME BREAKS IN CLOUDS AND SURFACE WARMING. RADAR TRENDS AND RAP GUIDANCE CONTINUES SHOWER ACTIVITY WITH SOME ISOLATED THUNDER THROUGH MIDNIGHT WITH SHOWERS ENDING GRADUALLY FROM WEST TO EAST AS THE SYSTEM PROGRESSES EASTWARD. WINDS HAVE BEEN BARELY STRONG ENOUGH TO JUSTIFY CONTINUING THE LAKE WIND ADVISORY...HOWEVER...THEY HAVE BEEN CONSISTENTLY OVER 20MPH AT A NUMBER OF STATIONS AROUND THE LAKE. WINDS WILL DECLINE BY OR SHORTLY AFTER NIGHTFALL AS SURFACE MIXING DECLINES AND SURFACE PRESSURE RELAXES WITH THE PASSAGE OF THE WEATHER SYSTEM. IN THE WAKE OF THIS SYSTEM...THE NEXT RIDGE MOVES IN FAIRLY QUICKLY AND WILL BEGIN TO WARM THE REGION BY SUNDAY. MARTIN .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY... A FEW CHANGES IN THE EXTENDED FORECAST DROPPED POPS ACROSS THE WESTERN ZONES TUESDAY NIGHT. DECIDED TO STAND PAT WITH THE POPS THAT WERE IN THE FORECAST FOR WEDNESDAY THROUGH FRIDAY EVEN THOUGH MODELS ARE HINTING AT A RATHER LARGE RIDGE ACROSS CENTRAL AND EASTERN MONTANA STARTING ON TUESDAY THROUGH THURSDAY WITH A SHORTWAVE MOVING ACROSS ALBERTA AND SOUTHERN SASKATCHEWAN THURSDAY NIGHT THROUGH FRIDAY. MODELS ALL SHOW THIS SHORTWAVE BUT DIFFER ON WHETHER IT WILL PRODUCE ANY RAINFALL. THE PRIMARY DIFFERENCE IS THAT THE MODELS ARE STRENGTHENING THE MID WEEK UPPER RIDGE SO THAT IS WHY I DECIDE TO LOWER POPS TUESDAY NIGHT THROUGH THURSDAY. THE 12Z MODEL RUNS ARE IN BETTER AGREEMENT WITH THIS FEATURE THEN THEY WERE WITH THE 00Z MODELS RUNS. RSMITH PREVIOUS DISCUSSION...THE EXTENDED FORECAST SHOWS LITTLE CHANGE AGAIN TONIGHT FROM THE LAST FEW MODEL RUNS. THE BEGINNING OF THE PERIOD SUNDAY NIGHT/MONDAY MORNING HAS RIDGING BUILDING INTO NORTHEAST MONTANA. THIS WILL HOLD OVER THE REGION THROUGH TUESDAY. THEN THE RIDGE MOVES A TOUCH SOUTH ALLOWING SOME RIPPLES IN THE UPPER FLOW TO COME INTO PLAY. STILL NO MAJOR EVENT TO POINT TOWARDS A BETTER CHANCE OF CONVECTION OVER ANOTHER SHORTWAVE. THEREFORE KEPT THE POPS LOW MID WEEK THROUGH THE END OF THE EXTENDED. TEMPERATURES WILL CONTINUE WITH AN ABOVE NORMAL TREND FOR THE REGION THROUGH THE ENTIRE PERIOD. PROTON && .AVIATION... PRIMARILY VFR CEILINGS BUT COULD HAVE TEMPORARY MVFR CEILING ACROSS THE TERMINALS DURING THE EVENING WITH CEILING DROPPING BELOW 3000 FT AGL NEAR ANY RAIN SHOWERS. EXPECT ISOLATED TO SCATTERED VICINITY SHOWERS TO CONTINUE ACROSS THE TERMINALS THROUGH TONIGHT. NORTHWEST WINDS WILL DROP TO NEAR 10 KNOTS THIS EVENING INCREASING SLIGHTLY TO 10 TO 20 KTS TOMORROW AFTERNOON. GAH/RAS && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
333 PM CDT THU AUG 2 2012 .SHORT TERM...TONIGHT THROUGH FRIDAY AFTERNOON. CONCERN IN THE NEXT 24 HRS WILL BE SLIGHT CHANCES FOR TSTMS EARLY ON ALONG WITH HIGH TEMPERATURES FOR FRIDAY. CURRENT WATER VAPOR IMAGERY ALONG WITH UPPER AIR AND WIND PROFILER DATA SHOW UPPER RIDGE NOW ANCHORED OVER TEXAS...AN UPPER LOW DROPPING SSE AND INTO THE WESTERN PART OF ALBERTA...PUTTING THE PLAINS IN WESTERLY FLOW. ONE CAN ALSO SEE THE SUBTROPICAL MOISTURE TAP STREAMING NORTH ACROSS WESTERN MEXICO...INTO THE FOUR CORNERS REGION AND THEN SWINGING EAST AROUND THE HIGH ACROSS OUR REGION. AT THE SURFACE...PRESSURE GRADIENT VERY WEAK ACROSS NEB/KS WITH ONE WEAK SURFACE LOW OVER OKLAHOMA AND ANOTHER ONE SITUATED ACROSS EASTERN MT/WY. SURFACE DEWPOINTS REMAIN FAIRLY HIGH OVER THE CWA RANGING FROM THE MID TO UPPER 60S AT LUNCHTIME. WEAK CONVECTIVE ACTIVITY HAS NEVER QUITE FADED AWAY IN OUR KS CWA ALTHOUGH DOUBT ANYTHING IS REACHING THE GROUND. CLOUD COVER ACROSS OUR SOUTHERN CWA HAS BEEN HOLDING IN A LITTLE LONGER THAN ANTICIPATED AND WITH SOME RE-DEVELOPMENT TO THE WEST...MAY NOT SEE HIGHS QUITE AS WARM AS EXPECT. ALSO WEAK CELLS MOVING ACROSS NORTHERN NEBRASKA HAVE ALSO HUNG IN DURING THE DAY. SOME OF THE HOURLY HRRR MODEL RUNS HAVE SHOWN THIS HANGING TOGETHER AND MOVING INTO THE WESTERN PART OF THE CWA LATER THIS AFTERNOON. WILL NEED TO MONITOR THIS OVER THE NEXT FEW HOURS. BELIEVE OUR BETTER...ALTHOUGH NOT GREAT...CHANCES FOR RAIN WILL BE LATER THIS EVENING AND OVERNIGHT. CHECKING OUT THE NEEDED INGREDIENTS...WE HAVE ADEQUATE INSTABILITY...MOISTURE AND SHEAR AT PRESENT BUT SEEM TO BE LACKING A FORCING MECHANISM. BELIEVE THE SURFACE TROUGH ALONG THE FRONT RANGE MAY FIT THE BILL AND WILL MONITOR CONVECTIVE DEVELOPMENT OUT WEST LATER THIS AFTERNOON. QUESTION THEN BECOMES WILL THIS ACTIVITY MAKE IT FAR ENOUGH EAST TO AFFECT OUR CWA. EARLY LOOK AT HRRR SHOWS THIS IS POSSIBLE AND WILL CHECK OUT THE 4KM WRF WHEN IT ARRIVES. SEEMS LIKE BETTER LOW LEVEL JET REMAINS WEST OVERNIGHT. ON FRIDAY AFTERNOON...THE UPPER LOW NOTED ABOVE WILL SHOULD BE CENTERED SOMEWHERE NEAR THE MT/NDAK/CANADA BORDER. THIS IS A DECENT WAVE AND SHOULD PROVIDE GOOD HEIGHT FALLS AND COOLER TEMPS ALOFT TO THE NORTHERN PLAINS. IT WILL ALSO PUSH A COLD FRONT INTO OUR NW CWA BY LATE AFTN OR EARLY EVENING. EXPECT SOME COMPRESSIONAL HEATING AHEAD OF THE FRONT AND WITH SURFACE WINDS BECOMING SOUTH TO SSW ANOTHER HOT DAY WILL BE IN STORE. DO NOT PLAN ON ISSUING ANY HEAT HEADLINES AS APPARENT TEMPERATURE VALUES FORECAST TO BE BETWEEN 98 AND 102 DEGREES IN THE SOUTHERN CWA. NOT SURE IF CONVECTION WILL BREAK OUT LATE FRIDAY AFTERNOON OR HOLD OFF UNTIL THE EVENING AS MOST MODELS SHOWING THE BULK OF THE PRECIPITATION BEING POST FRONTAL. IF I DO PUT IN AFTERNOON POPS...IT WILL MAINLY BE IN THE NORTHWEST AND WEST PART OF THE CWA. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY. CONCERNS FOR THE MID AND LONG TERM PERIOD WILL AGAIN FOCUS ON CHANCES FOR THUNDERSTORMS AS WELL AS COOLER TEMPERATURES FOR THE WEEKEND. BEGINNING THE MID TERM PERIOD...THE MODELS REMAIN IN FAIRLY CONSISTENT AGREEMENT AS THE UPPER LEVEL LOW CONTINUES TO SHIFT EASTWARD ACROSS PORTIONS OF MONTANA AND NORTH DAKOTA. AT THE SURFACE...A LARGE AREA OF LOW PRESSURE ALSO CONTINUES TO PUSH EASTWARD...WITH AN ASSOCIATED COLD FRONTAL BOUNDARY KNOCKING ON OUR DOORSTEP BY FRIDAY EVENING. THUNDERSTORM CHANCES CONTINUE INTO THE OVERNIGHT HOURS...WITH THE POSSIBILITY OF A FEW STRONG STORMS IN THE EARLY EVENING. BY LATE SATURDAY MORNING...THE FRONTAL BOUNDARY SHOULD BEGIN TO SAG SOUTHEAST OUT OF THE REGION WITH LINGERING SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS ALONG THE ELEVATED BOUNDARY. WITH FRONTAL PASSAGE OVERNIGHT FRIDAY...HIGH PRESSURE AND COOLER TEMPERATURES WILL SINK INTO THE REGION ALONG WITH NORTH WINDS. MUCH COOLER 850 TEMPERATURES ON THE ORDER OF 10 DEGREES COOLER THAN PREVIOUS DAYS WILL HELP DRASTICALLY REDUCE HIGH TEMPERATURES. A VERY NICE WEEKEND IS IN STORE WITH HIGHS IN THE MID TO UPPER 80S. BY THE BEGINNING OF THE WORKWEEK...THE UPPER LEVEL RIDGE WILL BEGIN TO BUILD BACK IN ACROSS THE ROCKIES...RESULTING IN NORTHWEST FLOW THROUGH THE EXTENDED PERIOD. A DRY FORECAST IS EXPECTED THROUGH THE BEGINNING OF THE WORKWEEK AS THE CENTRAL PLAINS REMAIN UNDER SURFACE HIGH PRESSURE. HOWEVER...TOWARDS THE END OF THE PERIOD...A FEW SHORT WAVE PERTURBATIONS ROUND THE EASTERN EDGE OF THE UPPER LEVEL RIDGE...AND COMBINED WITH A SURFACE TROUGH AXIS ALONG THE FRONT RANGE WILL HELP GENERATE SOME CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. CONTINUED SLIGHT CHANCES THROUGH THE PERIOD...MONDAY AND AGAIN TUESDAY NIGHT THROUGH WEDNESDAY. AS FOR TEMPERATURES...ALTHOUGH MUCH OF THE WARMER 850 TEMPERATURES REMAIN FARTHER WEST ACROSS THE ROCKIES...EXPECT A RISE IN TEMPERATURES THROUGH THE WORKWEEK. CONTINUED WITH HIGHS IN THE MID TO UPPER 90S. && .PREV DISCUSSION... /ISSUED 1213 PM CDT THU AUG 2 2012/ AVIATION...EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE FORECAST PERIOD. THERE IS JUST A SLIGHT CHANCE FOR THUNDERSTORMS LATER THIS AFTERNOON AND INTO THE OVERNIGHT HOURS BUT LOOKS TO BE 20 PERCENT SO WILL LEAVE OUT OF TAF. OTHERWISE WINDS WILL REMAIN LIGHT FOR MOST OF THE PERIOD ALTHOUGH THEY SHOULD BEGIN TO PICK UP OUT OF THE SOUTH A BIT BY MID MORNING FRIDAY AS THE PRESSURE GRADIENT TIGHTENS UP WITH APPROACHING COLD FRONT MOVING IN FROM THE NORTHWEST. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM/AVIATION...EWALD LONG TERM...SALTZMAN
AREA FORECAST DISCUSSION...UPDATED
NWS OMAHA/VALLEY NE
1228 PM CDT THU AUG 2 2012 .UPDATE... && .AVIATION... 12Z TAFS FOR KOFK...KLNK AND KOMA. VFR CONDITIONS WILL PREVAIL THRU THE 24HR FCST PD. DEE PREV DISCUSSION... /ISSUED 348 AM CDT THU AUG 2 2012/ DISCUSSION... SCATTERED SHOWERS CONTINUE TO MOVE EAST/SOUTHEAST THROUGH SOUTHEAST NEBRASKA ASSOCIATED WITH A PASSING SFC TROF AND UPPER LEVEL VORT MAX. DO EXPECT THIS ACTIVITY TO PUSH OUT OF THE CWA LATER THIS MORNING AS LATEST HRRR SUGGESTS. 06Z NAM LINGERS ACTIVITY ACROSS OUR EAST INTO THE AFTERNOON BUT BASED ON RADAR TRENDS...FEEL ACTIVITY WILL WANE THIS MORNING. ANOTHER WARM DAY IS EXPECTED WITH HIGHS TOPPING OUT IN THE MID TO UPPER 90S. WITH UNFAVORABLE MIXING IN EASTERLY LOW LEVEL FLOW...WE SHOULD REMAIN BELOW THE 100 DEGREE MARK. A WEAK SHORTWAVE IS FORECAST TO SLIDE THRU NEARLY ZONAL MID/UPPER LEVEL FLOW AND CONVECTION IS POSSIBLE IN UPSLOPE FLOW ACROSS WESTERN NEBRASKA LATE THIS AFTERNOON/EARLY THIS EVENING. THIS COULD SPREAD AS FAR EAST AS OUR WESTERN COUNTIES THIS EVENING. HAVE ADDED A SMALL POP TO ACCOUNT FOR THIS. OTHERWISE...MUCH OF THE OVERNIGHT SHOULD BE FAIRLY QUIET WITH STRONG WARM AIR ADVECTION UNDERWAY INTO FRIDAY. DESPITE LACK OF STRONG MIXING WINDS...AMPLE HEATING SHOULD PUSH FRIDAY HIGHS INTO THE UPPER 90S IF NOT LOWER 100S. A VIGOROUS SHORTWAVE WILL DROP OVER THE NORTHERN PLAINS FRIDAY NIGHT PUSHING A COLD FRONT INTO THE CENTRAL PLAINS. LATEST MODEL DATA SHOWS THAT THIS FRONT SHOULD ENTER INTO THE NORTHERN CWA BY 00-03Z SATURDAY AND MOVE SOUTH OF THE CWA BY 12-15Z SATURDAY. SHOWERS/TSTMS ARE EXPECTED TO DEVELOP TO OUR NORTH ALONG THE COLD FRONT FRIDAY AFTERNOON AND SPREAD INTO THE NRN CWA FRIDAY EVENING. CONVECTION SHOULD CONTINUE ALONG AND BEHIND THE BOUNDARY INTO SATURDAY MORNING. COOLER TEMPERATURES TO FOLLOW WITH HIGHS ON SATURDAY ONLY IN THE 80S AS SURFACE HIGH PRESSURE BUILDS SOUTH. NORTHWEST UPPER LEVEL FLOW IS EXPECTED THRU THE REMAINDER OF THE FORECAST AS UPPER RIDGE BUILDS TO OUR WEST. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
626 AM CDT THU AUG 2 2012 .AVIATION... 12Z TAFS FOR KOFK...KLNK AND KOMA. VFR CONDITIONS ARE FORECAST THROUGH FRIDAY MORNING. THINNING MID AND HIGH CLOUDINESS CAN BE EXPECTED THROUGH THE AFTERNOON WITH GENERALLY LIGHT NORTHEAST WINDS UNDER 10KTS. DERGAN && .PREV DISCUSSION... /ISSUED 348 AM CDT THU AUG 2 2012/ DISCUSSION... SCATTERED SHOWERS CONTINUE TO MOVE EAST/SOUTHEAST THROUGH SOUTHEAST NEBRASKA ASSOCIATED WITH A PASSING SFC TROF AND UPPER LEVEL VORT MAX. DO EXPECT THIS ACTIVITY TO PUSH OUT OF THE CWA LATER THIS MORNING AS LATEST HRRR SUGGESTS. 06Z NAM LINGERS ACTIVITY ACROSS OUR EAST INTO THE AFTERNOON BUT BASED ON RADAR TRENDS...FEEL ACTIVITY WILL WANE THIS MORNING. ANOTHER WARM DAY IS EXPECTED WITH HIGHS TOPPING OUT IN THE MID TO UPPER 90S. WITH UNFAVORABLE MIXING IN EASTERLY LOW LEVEL FLOW...WE SHOULD REMAIN BELOW THE 100 DEGREE MARK. A WEAK SHORTWAVE IS FORECAST TO SLIDE THRU NEARLY ZONAL MID/UPPER LEVEL FLOW AND CONVECTION IS POSSIBLE IN UPSLOPE FLOW ACROSS WESTERN NEBRASKA LATE THIS AFTERNOON/EARLY THIS EVENING. THIS COULD SPREAD AS FAR EAST AS OUR WESTERN COUNTIES THIS EVENING. HAVE ADDED A SMALL POP TO ACCOUNT FOR THIS. OTHERWISE...MUCH OF THE OVERNIGHT SHOULD BE FAIRLY QUIET WITH STRONG WARM AIR ADVECTION UNDERWAY INTO FRIDAY. DESPITE LACK OF STRONG MIXING WINDS...AMPLE HEATING SHOULD PUSH FRIDAY HIGHS INTO THE UPPER 90S IF NOT LOWER 100S. A VIGOROUS SHORTWAVE WILL DROP OVER THE NORTHERN PLAINS FRIDAY NIGHT PUSHING A COLD FRONT INTO THE CENTRAL PLAINS. LATEST MODEL DATA SHOWS THAT THIS FRONT SHOULD ENTER INTO THE NORTHERN CWA BY 00-03Z SATURDAY AND MOVE SOUTH OF THE CWA BY 12-15Z SATURDAY. SHOWERS/TSTMS ARE EXPECTED TO DEVELOP TO OUR NORTH ALONG THE COLD FRONT FRIDAY AFTERNOON AND SPREAD INTO THE NRN CWA FRIDAY EVENING. CONVECTION SHOULD CONTINUE ALONG AND BEHIND THE BOUNDARY INTO SATURDAY MORNING. COOLER TEMPERATURES TO FOLLOW WITH HIGHS ON SATURDAY ONLY IN THE 80S AS SURFACE HIGH PRESSURE BUILDS SOUTH. NORTHWEST UPPER LEVEL FLOW IS EXPECTED THRU THE REMAINDER OF THE FORECAST AS UPPER RIDGE BUILDS TO OUR WEST. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
348 AM CDT THU AUG 2 2012 .DISCUSSION... SCATTERED SHOWERS CONTINUE TO MOVE EAST/SOUTHEAST THROUGH SOUTHEAST NEBRASKA ASSOCIATED WITH A PASSING SFC TROF AND UPPER LEVEL VORT MAX. DO EXPECT THIS ACTIVITY TO PUSH OUT OF THE CWA LATER THIS MORNING AS LATEST HRRR SUGGESTS. 06Z NAM LINGERS ACTIVITY ACROSS OUR EAST INTO THE AFTERNOON BUT BASED ON RADAR TRENDS...FEEL ACTIVITY WILL WANE THIS MORNING. ANOTHER WARM DAY IS EXPECTED WITH HIGHS TOPPING OUT IN THE MID TO UPPER 90S. WITH UNFAVORABLE MIXING IN EASTERLY LOW LEVEL FLOW...WE SHOULD REMAIN BELOW THE 100 DEGREE MARK. A WEAK SHORTWAVE IS FORECAST TO SLIDE THRU NEARLY ZONAL MID/UPPER LEVEL FLOW AND CONVECTION IS POSSIBLE IN UPSLOPE FLOW ACROSS WESTERN NEBRASKA LATE THIS AFTERNOON/EARLY THIS EVENING. THIS COULD SPREAD AS FAR EAST AS OUR WESTERN COUNTIES THIS EVENING. HAVE ADDED A SMALL POP TO ACCOUNT FOR THIS. OTHERWISE...MUCH OF THE OVERNIGHT SHOULD BE FAIRLY QUIET WITH STRONG WARM AIR ADVECTION UNDERWAY INTO FRIDAY. DESPITE LACK OF STRONG MIXING WINDS...AMPLE HEATING SHOULD PUSH FRIDAY HIGHS INTO THE UPPER 90S IF NOT LOWER 100S. A VIGOROUS SHORTWAVE WILL DROP OVER THE NORTHERN PLAINS FRIDAY NIGHT PUSHING A COLD FRONT INTO THE CENTRAL PLAINS. LATEST MODEL DATA SHOWS THAT THIS FRONT SHOULD ENTER INTO THE NORTHERN CWA BY 00-03Z SATURDAY AND MOVE SOUTH OF THE CWA BY 12-15Z SATURDAY. SHOWERS/TSTMS ARE EXPECTED TO DEVELOP TO OUR NORTH ALONG THE COLD FRONT FRIDAY AFTERNOON AND SPREAD INTO THE NRN CWA FRIDAY EVENING. CONVECTION SHOULD CONTINUE ALONG AND BEHIND THE BOUNDARY INTO SATURDAY MORNING. COOLER TEMPERATURES TO FOLLOW WITH HIGHS ON SATURDAY ONLY IN THE 80S AS SURFACE HIGH PRESSURE BUILDS SOUTH. NORTHWEST UPPER LEVEL FLOW IS EXPECTED THRU THE REMAINDER OF THE FORECAST AS UPPER RIDGE BUILDS TO OUR WEST. && .AVIATION... 06Z TAFS FOR KOMA...KLNK...AND KOFK. SHRA/TSRA CURRENTLY IN THE KOFK AREA. OUTFLOW FROM THE STORMS MAY GENERATE SOME NORTHWEST WINDS 10 TO 20KTS AS IT GETS TO KOMA AND KLNK. INCLUDED THIS IN THE TAF AS WELL AS SHRA AND ISOLATED TSRA THROUGH 11Z. CONTINUED VFR CONDITIONS...HOWEVER MVFR CONDITIONS MAY DEVELOP WITH SOME OF THE STORMS. STORMS MAY TRY TO HANG ON INTO THE MORNING HOURS...HOWEVER CONFIDENCE LOW ENOUGH NOT TO INCLUDE PAST 12Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1154 PM CDT WED AUG 1 2012 .AVIATION... 06Z TAFS FOR KOMA...KLNK...AND KOFK. SHRA/TSRA CURRENTLY IN THE KOFK AREA. OUTFLOW FROM THE STORMS MAY GENERATE SOME NORTHWEST WINDS 10 TO 20KTS AS IT GETS TO KOMA AND KLNK. INCLUDED THIS IN THE TAF AS WELL AS SHRA AND ISOLATED TSRA THROUGH 11Z. CONTINUED VFR CONDITIONS...HOWEVER MVFR CONDITIONS MAY DEVELOP WITH SOME OF THE STORMS. STORMS MAY TRY TO HANG ON INTO THE MORNING HOURS...HOWEVER CONFIDENCE LOW ENOUGH NOT TO INCLUDE PAST 12Z. && .PREV DISCUSSION... /ISSUED 1004 PM CDT WED AUG 1 2012/ UPDATE... DID AN EVENING UPDATE A LITTLE EARLIER TO ACCOUNT FOR HIGHER POPS IN THE NORTHEAST AND CONTINUED SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FARTHER SOUTHEAST OVERNIGHT. DISCUSSION... THE EVENING OAX SOUNDING WAS ON THE DRY SIDE WITH LESS THAN ONE INCH PRECIP WATER...LBF HOWEVER HAD A MUCH MORE FAVORABLE SOUNDING WITH AROUND 3200 J/KG FOR CAPE AND LITTLE CINH AND 1.34 FOR PRECIP WATER. THE MOISTURE TRANSPORT VECTORS CONTINUE TO BRING THE MOISTURE EASTWARD AND SOUTHWARD...SO SCATTERED POPS STILL SEEM ON TRACK. GUSTY WINDS ARE POSSIBLE WITH DOWNDRAFT CAPE OF 1800 J/KG. SO FAR HAVE HAD REPORTS OF 40 TO 50 MPH NEAR NELIGH. THE NEW NAM TRIES TO HOLD ON TO THE PRECIPITATION THURSDAY MORNING FARTHER NORTH SO THIS WILL NEED TO BE ASSESSED. && PREV DISCUSSION... /ISSUED 501 PM CDT WED AUG 1 2012/ DISCUSSION... IT APPEARS THAT A SHORT REPRIEVE FROM THE OPPRESSIVE DRY CONDITIONS THAT HAVE PLAGUED US AS OF LATE IS ON THE HORIZON AS A COUPLE OF COLD FRONTS APPROACH THE PLAINS. RADAR LOOP WAS SHOWING PCPN ACTIVITY OVER WESTERN NEBRASKA AND PARTS OF SOUTH DAKOTA WHILE LATEST OBS WERE DEPICTING A BNDRY EXTENDING ALONG THE ND/SD BORDER WITH CAA SLOWLY SPREADING SWD OVER NRN SD. THE BIG QUESTION IS WILL THIS RESULT IN PCPN OVER THE CWA LATER TONIGHT. IT SEEMS THE MODELS ARE TRYING TO STALL THE FRONT IN THE VICINITY OF THE NRN CWA...BUT GOOD CHUNK OF DPVA DOES CROSS THE CWA...AND WITH STOUT 315K UPGLIDE NOT UNREASONABLE AT THIS POINT TO EXPECT SOME HIGH BASED ACTIVITY DEVELOPING. LATEST HRRR SEEMS TO HAVE A DECENT HANDLE ON THINGS... WHICH SUGGEST ACTIVITY COULD GET INTO EASTERN NEBRASKA BEFORE MIDNIGHT. CHANCES FOR ANOTHER ROUND PCPN ARE ON TAP HEADING INTO THE WEEKEND. MODELS ARE IN VERY GOOD AGREEMENT THAT UPSTREAM SHORTWAVE TROF OVER BRITISH COLUMBIA WILL SLIGHTLY BREAK DOWN THE CONUS UPPER RIDGE AS IT DROPS INTO THE LOWER 48. THE THERMAL GRADIENT WITH THE ATTENDANT COLD FRONT WILL BE MORE STOUT IN NATURE. WITH DECENT ENVIRONMENTAL MOISTURE ON HAND... PRECIP WATER VALUES AROUND 2"/KI OF 40...IS REASONABLE TO MAINTAIN POPS FRIDAY NIGHT. POSSIBLE LINGERING ACTIVITY THEN SATURDAY MORNING OVER THE SRN CWA. RELATIVELY COOLER AFTN HIGHS IN THE MID 80S THEN SUNDAY AFTERNOON. HEADING INTO NEXT WEEK...THE SITUATION LOOKS RATHER BLEAK WITH DRY CONDITIONS AND HIGH TEMPS PUSHING BACK TO THE MID/UPPER 90S AS AN UPPER RIDGE RETURNS OVER THE CONUS. DEE/BCM && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ ZAPOTOCNY
AREA FORECAST DISCUSSION UPDATE
NWS LAS VEGAS NV
1054 PM PDT WED AUG 1 2012 .SYNOPSIS...A DISTURBANCE IN THE ATMOSPHERE COMBINED WITH ABUNDANT MOISTURE AND INSTABILITY WILL RESULT IN SHOWERS AND THUNDERSTORMS AROUND AT TIMES THROUGH THIS WEEKEND. ALTHOUGH HEAVY RAIN WILL BE THE PRIMARY THREAT WITH HEAVIER STORMS...GUSTY WINDS AND HAIL MAY ALSO OCCUR. BY EARLY NEXT WEEK DRIER AIR LOOKS TO SLOWLY SPREAD EAST ACROSS THE AREA WHICH SHOULD DECREASE THE CHANCES FOR THUNDERSTORMS AND ALSO RESULT IN A WARMING TREND. && .UPDATE... THE OUTFLOW BOUNDARY ASSOCIATED WITH THE LINE OF THUNDERSTORMS PREVIOUSLY EXPECTED TO PASS ACROSS THE LAS VEGAS VALLEY AND FURTHER SOUTH HAVE DISSIPATED AS THE OUTFLOW BOUNDARY ASSOCIATED WITH THE STORMS HAD MOVED OUT TOO FAR AHEAD OF THE LINE OF STORMS...AND CUT OFF FAVORABLE INFLOW TO STORMS DESPITE LIS BETWEEN -3 AND -5 AND CAPE VALUES FROM 1000 TO 2000 J/KG. THE FLASH FLOOD WATCH HAS BEEN CANCELLED...AND ANY MENTION OF SHOWERS OR THUNDERSTORMS HAVE BEEN REMOVED FROM THE OVERNIGHT FORECAST. STILL EXPECT SUFFICIENT MOISTURE TO BE IN PLACE FOR A CHANCE OF CONVECTION TOMORROW...BUT NEED TO FURTHER ASSESS HOW MUCH ANY EXPECTED WARMING AND DRY AIR MOVING IN ALOFT WILL MITIGATE DEVELOPMENT. -KENNEDY- && .AVIATION...FOR MCCARRAN...NO SIGNIFICANT WEATHER IS EXPECTED THE REMAINDER OF THE NIGHT. THERE WILL BE A CHANCE OF THUNDERSTORMS ONCE AGAIN ON THURSDAY...AS SUFFICIENT MOISTURE REMAINS IN PLACE FOR THUNDERSTORM DEVELOPMENT. THUNDERSTORMS WILL DEVELOP INITIALLY OVER HIGHER TERRAIN. OUTSIDE OF ANY THUNDERSTORM OUTFLOWS...WINDS WILL BE RELATIVELY LIGHT. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...NO SIGNIFICANT WEATHER IS EXPECTED THE REMAINDER OF THE NIGHT AS THUNDERSTORMS HAVE DISSIPATED ACROSS THE FORECAST AREA. THERE WILL BE A CHANCE OF THUNDERSTORMS ACROSS THE REGION AGAIN TOMORROW...AS SUFFICIENT MOISTURE REMAINS IN PLACE. THUNDERSTORMS WILL DEVELOP INITIALLY OVER HIGHER TERRAIN. OUTSIDE OF ANY THUNDERSTORM OUTFLOWS...WINDS WILL BE RELATIVELY LIGHT. -KENNEDY- && .PREV DISCUSSION... 331 PM PDT WED AUG 1 2012 .SHORT TERM...SO FAR THINGS HAVE NOT BEEN AS ACTIVE THIS AFTERNOON AS THEY WERE AT THIS POINT YESTERDAY DESPITE AN EXTREMELY MOIST ATMOSPHERE...PLENTY OF INSTABILITY AND MUCH MORE SUNSHINE. WATER VAPOR IMAGERY SHOWS THE CENTER OF THE MID/UPPER LEVEL LOW WAS OVER SOUTHERN CLARK COUNTY AND MOVING SLOWLY NORTHEASTWARD. RADAR SHOWS AT THE PRESENT MOST OF THE ACTIVITY WAS ABOUT 100 MILES AWAY FROM THE CENTER OF THE LOW. THE ATMOSPHERE REMAINS EXCEPTIONALLY MOIST WITH THE 12Z SOUNDING THIS MORNING FROM OUR OFFICE HAVING A PWAT OF 1.82 INCHES. THIS TIED FOR THE SECOND HIGHEST PWAT EVER RECORDED IN THE SOUNDING CLIMATOLOGY FOR SOUTHERN NEVADA WITH A VALUE BACK IN AUGUST OF 1984 (THE HIGHEST EVER WAS 1.86 INCHES IN JULY 1966). WITH SO MUCH MOISTURE PRESENT ANY SHOWER OR THUNDERSTORM THAT GETS GOING WILL HAVE THE POTENTIAL TO PRODUCE EXTREMELY HEAVY RAIN IN A SHORT PERIOD OF TIME. THUS THE FLASH FLOOD WATCH OUT WILL REMAIN IN EFFECT. THE MAIN CHALLENGE FOR THIS EVENING AND THE REST OF TONIGHT WILL BE JUST HOW ACTIVE THINGS WILL GET. WITH THE MID/UPPER LEVEL LOW PROGGED TO BE AROUND THROUGH TONIGHT IT WILL BE HARD TO COMPLETELY SHUT DOWN ALL CONVECTION EXCEPT IN ANY AREAS WHERE THE AIR MASS GETS WORKED OVER ENOUGH THAT IT BECOMES MUCH MORE STABLE. IF YOU BELIEVE THE WRF...GFS AND ECMWF CONVECTION SHOULD WIND DOWN AROUND 03Z OR SO THIS EVENING. ON THE OTHER HAND...THE LOCAL ARW AND NMM MODELS AS WELL AS THE HRRR MODEL SHOW THE REVERSE WITH THINGS BECOMING MUCH MORE ACTIVE LATER THIS EVENING. 700 MB STEERING FLOW IS FROM THE NORTHEAST AND RADAR PRESENTLY SHOWS SHOWERS AND THUNDERSTORMS IN AN ARCH FROM AROUND ELY TO KANAB. TYPICALLY THIS PATTERN WOULD FAVOR THIS CONVECTION EVENTUALLY WORKING IN DURING THE LATE EVENING INTO CLARK COUNTY. IN THE PAST STORMS IN LAS VEGAS ORIGINATING FROM A NORTHEAST FLOW HAVE USUALLY BEEN RATHER POTENT. THUS...BASED ON A BLEND OF MODELS WE HAVE KEPT POPS IN THROUGH THE NIGHT FOR MUCH OF LINCOLN...CLARK...MOHAVE....EASTERN SAN BERNARDINO AND SOUTHERN NYE COUNTIES. ALTHOUGH FLASH FLOODING REMAINS A THREAT...WE CANNOT RULE OUT GUSTY WINDS OR HAIL WITH SOME STORMS ESPECIALLY IF THINGS DRY OUT A LITTLE. VERY LITTLE CHANGE IN THE OVERALL PATTERN IS EXPECTED FOR THURSDAY AND FRIDAY. THE MID/UPPER LEVEL LOW IS FORECAST TO GET TRAPPED NEAR THE TRIPLE POINT OF CALIFORNIA...NEVADA AND ARIZONA AND EVENTUALLY WEAKEN TO A MORE ILL-DEFINED VORTICITY FEATURE. MEANWHILE HIGH PRESSURE IN THE MID AND UPPER LEVELS IS FORECAST TO BECOME CENTERED OVER CENTRAL NEVADA. THIS HIGH WILL KEEP AN EASTERLY MID-LEVEL FLOW OVER OUR AREA WHICH BY FRIDAY WILL HELP TO PUSH THE VORTICITY FEATURE TO THE SOUTHWEST AND BY FRIDAY NIGHT PUSH IT OFFSHORE OF SOCAL. OVER THE NEXT 2 DAYS THE FARTHER NORTHWEST ONE GOES IN THE CWFA THE LESS OF CHANCE FOR CONVECTION AS THE HIGH ALOFT WILL KEEP THE ATMOSPHERE MUCH MORE STABLE. FURTHER SOUTH THE COMBINATION OF THE VORTICITY FEATURE...INSTABILITY AND SUFFICIENT MOISTURE WILL KEEP THE POTENTIAL FOR THUNDERSTORMS AROUND. WHILE PWATS ARE FORECAST TO REMAIN OVER AN INCH OVER THE MOJAVE DESERT WHICH WILL SUPPORT HEAVY RAIN PRODUCING STORMS...WE WILL NOT ISSUE ANY FLASH FLOOD WATCHES FOR THURSDAY OR FRIDAY AT THIS TIME DUE TO UNCERTAINTIES IN JUST HOW ACTIVE IT WILL GET. TEMPS SHOULD BE A FEW DEGREES ABOVE NORMAL BUT MUCH WARMER THAN WHAT WE HAVE SEEN THE PAST FEW DAYS OVER THE MOJAVE DESERT. WELL ABOVE NORMAL TEMPS WILL CONTINUE OVER INYO AND ESMERALDA COUNTY. .LONG TERM...THE OLD VORTICITY FEATURE OFF OF SOCAL GETS CAUGHT UP IN A BROAD MID/UPPER LEVEL TROUGH OFF THE WEST COAST ON SATURDAY. IT APPEARS ENOUGH MOISTURE AND INSTABILITY REMAIN AROUND ON SATURDAY THAT THE POTENTIAL FOR THUNDERSTORMS WILL CONTINUE ESPECIALLY ACROSS THE NORTHERN HALF OF THE CWFA WHERE THE BEST INSTABILITY LOOKS TO SET UP. BY SATURDAY NIGHT INTO SUNDAY DRIER AND MORE STABLE AIR IS SHOWN TO WORK IN FROM THE SOUTH AS THE OFFSHORE TROUGH EDGES CLOSER TO THE COAST AND MOST OF THE EMBEDDED ENERGY WITHIN THE TROUGH STARTS TO LIFT ON NORTH. THUS SUNDAY MAY NOT BE QUITE AS ACTIVE FOR CONVECTION AND POPS SHOW A SLIGHT TREND DOWN THEN. BY MONDAY INTO NEXT WEDNESDAY THE TROUGH OFFSHORE STILL EXISTS AND RIDGING ALOFT SITS OVER THE FOUR CORNERS. THIS WOULD FAVOR A SOUTHWEST FLOW ALOFT ACROSS OUR AREA WHICH WOULD SPREAD DRIER AND STABLE AIR FURTHER EAST WITH TIME. I DID LOWER POPS AND DEWPOINTS IN THE WESTERN HALF OF THE AREA TO ACCOUNT FOR THIS HOWEVER MOIST AND UNSTABLE AIR IS SHOWN TO LINGER OVER MOHAVE COUNTY AND THIS PART OF THE AREA MAY NEVER REALLY DRY OUT. TEMPS SHOULD RISE BACK CLOSER TO NORMAL IN MOST AREAS AND MAY EVEN BE A FEW DEGREES ABOVE NORMAL ON MONDAY AND TUESDAY AS THINGS REALLY DRY OUT. I LEANED CLOSELY TO THE ECMWF MOS AND BIAS CORRECTED NUMBERS FOR HIGHS. && .VEF WATCHES/WARNINGS/ADVISORIES... NV...NONE. AZ...NONE. CA...NONE. && $$ STACHELSKI HTTP://WEATHER.GOV/LASVEGAS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1021 PM EDT FRI AUG 3 2012 .SYNOPSIS... A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY FORECAST. && .NEAR TERM /UNTIL 8 AM SATURDAY MORNING/... AS OF 1012 PM EDT FRIDAY...ANOTHER ROUND OF MINOR ADJUSTMENTS PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN. MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN. OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR 50 DEGREES. && .SHORT TERM /8 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8 AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS. CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER THE HIGHER TERRAIN. STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON. DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 344 PM EDT FRIDAY...ECMWF AND GFS INDICATE A CHANCE OF SHOWERS EARLY MONDAY...MAINLY ACROSS VERMONT...AS COLD FRONT AND UPPER TROUGH PUSH EAST OF THE REGION. MID LEVEL DRY SLOT THEN BUILDS IN BY MIDDAY...SO EXPECT CLEARING SKIES ACROSS THE REGION BY MONDAY AFTERNOON. IT WILL TURN LESS HUMID AND BE A LITTLE COOLER...WITH HIGHS GENERALLY IN THE UPPER 70S AND LOWER 80S. ECMWF AND GFS REMAIN IN GOOD AGREEMENT IN SHOWING A WEAK RIDGE OF HIGH PRESSURE OVER THE NORTH COUNTRY FROM MONDAY NIGHT THROUGH EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. A SERIES OF WEAK UPPER SHORTWAVES WILL THEN MOVE ACROSS THE REGION WEDNESDAY AFTERNOON THROUGH THURSDAY...BRINGING A LOW CHANCE FOR SHOWERS AND STORMS TO THE REGION...ESPECIALLY TO THE HIGHER TERRAIN AND ACROSS THE NORTHERN ZONES. LATEST ECMWF INDICATING A MORE PRONOUNCED TROUGH MOVING INTO THE NORTHEAST FRIDAY...SO HAVE GONE WITH CHANCE POPS ACROSS THE ENTIRE AREA FRIDAY INTO FRIDAY NIGHT. TEMPERATURES WILL BE A BIT ABOVE NORMAL TUESDAY THROUGH THURSDAY...THEN LOWER TO SEASONAL LEVELS FRIDAY DUE MORE CLOUD COVER. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTED AT MOST LOCATIONS THROUGH THE PERIOD. THE ONLY EXCEPTION TO THIS WILL BE SOME VLIFR CONDITIONS AT KSLK AND KMPV BETWEEN 07Z AND 13Z DUE TO LOW CLOUDS AND FOG. SCATTERED CUMULUS CLOUDS SHOULD FORM SATURDAY AFTERNOON AND ISOLATED STORMS WILL DEVELOP AFTER 20Z. WINDS WILL GENERALLY BE LIGHT AND VARIABLE TONIGHT...THEN TREND TOWARD A MORE SOUTHERLY DIRECTION LATE SATURDAY MORNING INTO AFTERNOON. OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY SUNDAY. THERE WILL BE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON/EVENING WITH BRIEF MVFR POSSIBLE. MVFR/IFR IN BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z SUNDAY. APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL. COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. && .MARINE... RELATIVELY LIGHT WINDS EXPECTED FROM THIS EVENING THROUGH THE DAY SATURDAY. WINDS WILL TURN NORTHERLY FROM 5 TO 15 KNOTS THIS EVENING...BECOMING LIGHT AND VARIABLE OVERNIGHT...AND THEN 5 TO 15 KNOTS OUT OF THE SOUTH ON SATURDAY. HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED. WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4 FEET BY SUNDAY. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...NEILES NEAR TERM...BOYD SHORT TERM...NEILES LONG TERM...RJS AVIATION...EVENSON/RJS MARINE...MUCCILLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
934 PM EDT FRI AUG 3 2012 .SYNOPSIS... A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY... FOLLOWED BY COOLER DRY WEATHER ON MONDAY. && .NEAR TERM /THROUGH SATURDAY/... 930 AM UPDATE...NO CHGS TO CRNT FCST WITH A QUIET OVRNGT PD XPCTD. PREV BLO... 730 PM UPDATE...WELL IT TOOK SOME OF THE HIGHEST TRRN IN THE CWA TO HELP TRIGGER AN ISOLD TSRA OVER CNTRL DELAWARE CNTY. STORM BCM ANCHORED NEAR MT PISGAH AND BACK-BUILT/TRAINED FOR NEARLY 2 HRS. RR AMTS UP 3-3.5 INCHES. THIS STORM HAS SINCE DSPTD AND SEE LTL POTNL FOR ADDNL DVLPMNT ACRS THE FCST AREA...SO WILL REMOVE POPS AND GO WITH MAINLY CLEAR TO SKC TNGT. FOG POTNL ALSO LIMITED AND DON`T XPCT IT TO BE DENSE ENUF TO INCLUDE IN THE WX GRIDS. PREV BLO... 4 PM UPDATE...MAINLY SKC ACRS THE BGM FCST AREA WITH XCPTN OF SOME MID/HI CLD ACRS THE FINGER LAKES AND FAR SE ZONES. WSR-88D SHOWS A WEAK E-W BNDRY BNDRY FROM SRN SCHUYLER/TOMPKINS ACRS NRN BROOME INTO SRN CHENANGO CNTY. HOWEVER...TD`S ARE LOWEST ACRS THE SRN TIER AND ANY LOW LVL CONVERGENCE WILL BE WEAK DUE TO THE LGT WINDS VCNTY OF THE BNDRY. LACK OF UPR DYNAMICS AND LOW LVL CIN CONTINUE TO IMPEDE DVLPMNT. GIVEN THESE TRENDS...WE LOWERED POPS TO SLGT CHC FOR LATE THIS AFTN/EVNG AND LOWERED SKY CVR. PREV BLO... 2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS (DOWN BURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS EVENING WILL DIMINISH QUICKLY THIS EVENING. WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE 1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING. THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z. ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND 0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN. HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW. HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND 12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION. CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY. IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE 90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED. COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND WILL LEAN WITH THEIR GENTLER APPROACH. ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS... THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS UNDER WEAK HIGH PRESSURE WILL CONTINUE THROUGH TOMORROW AFTERNOON. ONCE AGAIN THERE WILL BE A SMALL CHANCE FOR AN ISOLATED SHOWER OR THUNDERSTORM, BUT NOT CURRENTLY EXPECTING ANY TO AFFECT THE TAF SITES. THERE IS ALSO THE CHANCE OF SOME LIGHT FOG AT KELM, BUT LIKE LAST NIGHT, NOT EXPECTING ANY SIGNIFICANT REDUCTION IN VISIBILITY. WINDS WILL BE LIGHT AND VARIABLE INTO TOMORROW MORNING. THEY ARE EXPECTED TO PICK UP OUT OF THE SOUTH AT AROUND 10KTS. OUTLOOK... SAT AFTERNOON THROUGH SUN MORNING...VFR MUCH OF THE TIME. ISOLD- SCTD LATE AFTN/EARLY EVE TSRA PSBL...WITH BRIEF RESTRICTIONS. ALSO MVFR VSBYS POSSIBLE SUN AM DUE TO HAZE. SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS WITH MVFR/IFR RESTRICTIONS IN STORMS. MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...JAB NEAR TERM... SHORT TERM...JAB LONG TERM...JAB AVIATION...SLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
733 PM EDT FRI AUG 3 2012 .SYNOPSIS... A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY... FOLLOWED BY COOLER DRY WEATHER ON MONDAY. && .NEAR TERM /THROUGH SATURDAY/... 730 AM UPDATE...WELL IT TOOK SOME OF THE HIGHEST TRRN IN THE CWA TO HELP TRIGGER AN ISOLD TSRA OVER CNTRL DELAWARE CNTY. STORM BCM ANCHORED NEAR MT PISGAH AND BACK-BUILT/TRAINED FOR NEARLY 2 HRS. RR AMTS UP 3-3.5 INCHES. THIS STORM HAS SINCE DSPTD AND SEE LTL POTNL FOR ADDNL DVLPMNT ACRS THE FCST AREA...SO WILL REMOVE POPS AND GO WITH MAINLY CLEAR TO SKC TNGT. FOG POTNL ALSO LIMITED AND DON`T XPCT IT TO BE DENSE ENUF TO INCLUDE IN THE WX GRIDS. PREV BLO... 4 PM UPDATE...MAINLY SKC ACRS THE BGM FCST AREA WITH XCPTN OF SOME MID/HI CLD ACRS THE FINGER LAKES AND FAR SE ZONES. WSR-88D SHOWS A WEAK E-W BNDRY BNDRY FROM SRN SCHUYLER/TOMPKINS ACRS NRN BROOME INTO SRN CHENANGO CNTY. HOWEVER...TD`S ARE LOWEST ACRS THE SRN TIER AND ANY LOW LVL CONVERGENCE WILL BE WEAK DUE TO THE LGT WINDS VCNTY OF THE BNDRY. LACK OF UPR DYNAMICS AND LOW LVL CIN CONTINUE TO IMPEDE DVLPMNT. GIVEN THESE TRENDS...WE LOWERED POPS TO SLGT CHC FOR LATE THIS AFTN/EVNG AND LOWERED SKY CVR. PREV BLO... 2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS (DOWN BURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS EVENING WILL DIMINISH QUICKLY THIS EVENING. WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE 1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING. THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z. ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND 0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN. HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW. HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND 12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION. CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY. IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE 90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED. COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND WILL LEAN WITH THEIR GENTLER APPROACH. ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS... THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS UNDER WEAK HIGH PRESSURE WILL CONTINUE THROUGH TOMORROW AFTERNOON. ONCE AGAIN THERE WILL BE A SMALL CHANCE FOR AN ISOLATED SHOWER OR THUNDERSTORM, BUT NOT CURRENTLY EXPECTING ANY TO AFFECT THE TAF SITES. THERE IS ALSO THE CHANCE OF SOME LIGHT FOG AT KELM, BUT LIKE LAST NIGHT, NOT EXPECTING ANY SIGNIFICANT REDUCTION IN VISIBILITY. WINDS WILL BE LIGHT AND VARIABLE INTO TOMORROW MORNING. THEY ARE EXPECTED TO PICK UP OUT OF THE SOUTH AT AROUND 10KTS. OUTLOOK... SAT AFTERNOON THROUGH SUN MORNING...VFR MUCH OF THE TIME. ISOLD- SCTD LATE AFTN/EARLY EVE TSRA PSBL...WITH BRIEF RESTRICTIONS. ALSO MVFR VSBYS POSSIBLE SUN AM DUE TO HAZE. SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS WITH MVFR/IFR RESTRICTIONS IN STORMS. MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...JAB NEAR TERM... SHORT TERM...JAB LONG TERM...JAB AVIATION...SLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
725 PM EDT FRI AUG 3 2012 .SYNOPSIS... A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY... FOLLOWED BY COOLER DRY WEATHER ON MONDAY. && .NEAR TERM /THROUGH SATURDAY/... 4 PM UPDATE...MAINLY SKC ACRS THE BGM FCST AREA WITH XCPTN OF SOME MID/HI CLD ACRS THE FINGER LAKES AND FAR SE ZONES. WSR-88D SHOWS A WEAK E-W BNDRY BNDRY FROM SRN SCHUYLER/TOMPKINS ACRS NRN BROOME INTO SRN CHENANGO CNTY. HOWEVER...TD`S ARE LOWEST ACRS THE SRN TIER AND ANY LOW LVL CONVERGENCE WILL BE WEAK DUE TO THE LGT WINDS VCNTY OF THE BNDRY. LACK OF UPR DYNAMICS AND LOW LVL CIN CONTINUE TO IMPEDE DVLPMNT. GIVEN THESE TRENDS...WE LOWERED POPS TO SLGT CHC FOR LATE THIS AFTN/EVNG AND LOWERED SKY CVR. PREV BLO... 2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS (DOWN BURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS EVENING WILL DIMINISH QUICKLY THIS EVENING. WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE 1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING. THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z. ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND 0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN. HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW. HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND 12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION. CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY. IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE 90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED. COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND WILL LEAN WITH THEIR GENTLER APPROACH. ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS... THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL. && .AVIATION /23Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS UNDER WEAK HIGH PRESSURE WILL CONTINUE THROUGH TOMORROW AFTERNOON. ONCE AGAIN THERE WILL BE A SMALL CHANCE FOR AN ISOLATED SHOWER OR THUNDERSTORM, BUT NOT CURRENTLY EXPECTING ANY TO AFFECT THE TAF SITES. THERE IS ALSO THE CHANCE OF SOME LIGHT FOG AT KELM, BUT LIKE LAST NIGHT, NOT EXPECTING ANY SIGNIFICANT REDUCTION IN VISIBILITY. WINDS WILL BE LIGHT AND VARIABLE INTO TOMORROW MORNING. THEY ARE EXPECTED TO PICK UP OUT OF THE SOUTH AT AROUND 10KTS. OUTLOOK... SAT AFTERNOON THROUGH SUN MORNING...VFR MUCH OF THE TIME. ISOLD- SCTD LATE AFTN/EARLY EVE TSRA PSBL...WITH BRIEF RESTRICTIONS. ALSO MVFR VSBYS POSSIBLE SUN AM DUE TO HAZE. SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS WITH MVFR/IFR RESTRICTIONS IN STORMS. MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...JAB NEAR TERM...HEDEN SHORT TERM...JAB LONG TERM...JAB AVIATION...SLI
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
345 AM EDT THU AUG 2 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THURSDAY THROUGH THE WEEKEND...ACCOMPANIED BY ISOLATED THUNDERSTORMS EACH DAY. A WEAK COLD FRONT WILL REACH THE AREA MONDAY AND MAY LINGER AS IT WEAKENS SLOWLY THROUGH MID WEEK AS HIGH PRESSURE BUILDS IN BEHIND IT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 315 AM THURSDAY...MID-LEVEL S/W TROFS OR IMPULSES ACROSS CENTRAL NC AND UPSTATE GEORGIA...WILL BOTH MAKE A BEE-LINE TO THE SE U.S. COAST THIS AFTERNOON AND NIGHT. THESE IMPULSES ARE CURRENTLY RESPONSIBLE FOR THE SMALL CLUSTER OF TSTMS AT THE MOMENT VIA LATEST AND ADJACENT 88-DS. MAY HAVE TO ADD CONVECTION FOR THIS MORNING ACROSS THE ILM NC SECTION OF THE CWA GIVEN LATEST EXTRAPOLATION AND HRRR MODEL OUTPUT. MODELS TAKE THE MID-LEVEL S/W TROF OFF THE SE NC COAST EARLY THIS EVENING...RESULTING WITH NVA AND SUBSIDENCE IN ITS WAKE FOR THE REMAINDER OF THU NIGHT. FOR THE TIME BEING WILL GO WITH 20 TO POSSIBLY 30 POPS TODAY...MAINLY IN THE VICINITY OF THE MID-LEVEL S/W TROF. FOR THE PAST SEVERAL DAYS IT HAS BEEN A TUG-OF-WAR BETWEEN NAM MOS AND GFS MOS GUIDANCE FOR THE ILM CWA. WILL LEAN TOWARD THE NAM MOS GUIDANCE FOR THE TIME BEING. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM THURSDAY...MID TO UPPER TROUGH LIFTS OFF AND WEAKENS AS IT GETS SQUEEZED OUT BY RIDGE BUILDING IN OVER THE SOUTHEAST FROM THE EAST AND WEST. HEIGHTS WILL BE RISING FROM NEAR 588 DM FRI MORNING UP TO 594 DM BY SAT EVENING WITH INCREASED SUBSIDENCE AND PLENTY OF DRYING THROUGH THE MID LEVELS OF THE ATMOSPHERE. LOOKS LIKE A VERY TYPICAL SUMMER TIME MOISTURE PROFILE WITH MOISTURE LOCKED IN BELOW H85 AND RH VALUES DROPPING OFF TO 40 PERCENT OR LESS FROM H7 UP THROUGH H3. PCP WATER VALUES WILL BE DOWN LESS THAN A HALF INCH AND WILL CREEP UP TO 1.75 BY END OF PERIOD. MORE OF A W-SW FLOW ON FRI WILL BACK AROUND TO THE S THROUGH THE LOWER LEVELS AS BERMUDA HIGH BUILDS BACK INTO AREA FROM THE EAST THROUGH SAT. THIS WILL ALLOW A DEEPER MOISTURE RETURN BY THE LATTER HALF OF THE WEEKEND. LIGHT SOUTHERLY RETURN FLOW WILL BE ENHANCED EACH AFTERNOON BY THE SEA BREEZE AS TEMPS RISE INTO THE 90S WITH PLENTY OF SUNSHINE. THIS SHOULD ALLOW FOR SOME LOW LEVEL INSTABILITY AND CONVERGENCE ENOUGH TO PRODUCE SOME CU WITH ONLY SLIGHT CHC OF CONVECTIVE DEVELOPMENT. OVERNIGHT LOWS WILL FALL INTO THE 70S. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 300 AM THURSDAY...MID TO UPPER RIDGE WILL BUILD OVER THE CENTRAL CONUS AS TROUGH PUSHES SYSTEM EAST THROUGH EARLY NEXT WEEK. A COLD FRONT WILL MAKE IT INTO THE MOUNTAINS BY SUNDAY NIGHT AND WILL GET PUSHED EAST AS H5 TROUGH DIGS DOWN THROUGH THE SOUTHEAST ON MONDAY. THEREFORE WILL SEE INCREASED COVERAGE OF SHWRS/TSTMS ON MONDAY. THIS FRONT MAY GET STALLED AND MAKE SLOW PROGRESS EAST THROUGH MID WEEK AS IT COMES UP AGAINST STRONG ATLANTIC RIDGE. IT LOOKS LIKE IT WILL WEAKEN OVER THE AREA MAKING LITTLE PROGRESS EAST AS WEAK HIGH PRESSURE BUILDS INTO THE CAROLINAS BEHIND IT. SHOULD KEEP MORE UNSETTLED WEATHER ESPECIALLY ALONG THE COAST TUES AND WED. OVERALL SUNDAY SHOULD SEE ONE LAST DAY OF WARMER TEMPS AND SUNSHINE ON SUNDAY WITH PCP CHC INCREASING SLIGHTLY BUT EXPECT MUCH MORE IN THE WAY OF CLOUDS AND PCP HEADING INTO MON AND TUES AND THEREFORE TEMPS SHOULD BE A FEW DEGREES LOWER. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 06Z...PROB OF VCSH AT FLO/LBT BY 08-10Z IS LOW BUT WILL CONT TO MENTION IN TAFS. BEST CHANCE SHOULD BE AT LBT. VFR CONDITIONS EXPECTED TO GIVE WAY TO MVFR VSBYS IN BR 08-12Z. LOW CONFIDENCE OF IFR...BUT IF IFR OCCURS IT MOST LIKELY WOULD OCCUR AT THE COASTAL TERMINALS. LGT/VRBL WINDS WILL BECOME LIGHT SW AFT SUNRISE. VCSH VCTS EXPECTED 14-19Z AT THE COASTAL TERMINALS AND AFT 18Z AT FLO/LBT. WINDS BECOME SOUTHEAST TO SOUTH BY EARLY AFTERNOON. EXPECT CONVECTION TO DIURNALLY DISSIPATE DURING THE EVENING. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 330 AM THURSDAY...BERMUDA HIGH PRESSURE SFC AND ALOFT WILL RIDGING WESTWARD TO THE SE U.S. COAST THROUGHOUT THE NEAR TERM. A COUPLE OF MID-LEVEL S/W TROFS WILL MOVE OFF THE MAINLAND THIS NEAR TERM AND RESULT IN A SOMEWHAT PINCHED SFC PG. WILL BE ADVERTISING SW WINDS AROUND 15 KT...OR JUST 10-15 KT. AS FOR SIG SEAS...A LOCALLY PRODUCED 2+ FOOT WIND WAVE COMBINED WITH A 1-2 FT ESE GROUND SWELL...WILL COMBINE TO PRODUCE SIG SEAS IN THE 2 TO 4 FT RANGE. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM THURSDAY...SOUTHERLY RETURN FLOW AROUND BERMUDA HIGH WILL CONTINUE THROUGH THE PERIOD. WINDS OVERALL WILL BE 10 KTS OR LESS BUT WILL SEE SOME GUSTINESS WITH SLIGHTLY HIGHER WINDS EACH AFTERNOON IN SEA BREEZE CLOSER TO SHORE. SEAS WILL REMAIN 2 TO 3 FT WITH A SLIGHTLY LONGER PERIOD EASTERLY SWELL MIXING IN WITH THE LOCALLY GENERATED WIND WAVE. LONG TERM /SUNDAY THROUGH MONDAY/... AS OF 300 AM THURSDAY...SOUTHERLY RETURN FLOW AROUND BERMUDA HIGH WILL INCREASE SLIGHTLY AS GRADIENT TIGHTENS LATE SUNDAY INTO MONDAY AS WEAK COLD FRONT MAKES ITS WAY INTO THE CAROLINAS. THEREFORE EXPECT WINDS TO PICK UP FROM AROUND 10 KTS ON SUNDAY TO A MORE SOLID 15 KTS THROUGH MONDAY AS FRONT NEARS THE WATERS. WNA ALSO SHOWING A LONGER PERIOD SE SWELL UP TO 12 SECONDS REACHING THE WATERS ON MONDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DCH SHORT TERM...RGZ LONG TERM...RGZ AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
958 AM EDT THU AUG 2 2012 .SYNOPSIS... HIGH PRESSURE WILL GRADUALLY WEAKEN AS IT SHIFTS TO THE ATLANTIC COAST. A WEAK COLD FRONT WILL APPROACH THE AREA ON FRIDAY AND BECOME STATIONARY ACROSS THE LOWER GREAT LAKES. A STRONGER COLD FRONT WILL SWEEP ACROSS THE REGION BY SUNDAY EVENING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CURRENT FORECAST IS ON TRACK SO ONLY MINOR CHANGES PLANNED. 12Z SOUNDINGS SHOW RATHER WARM AIR IN LOW LEVELS WITH 850 MB TEMPERATURES IN THE RANGE OF +17 TO +19C. ADDITIONAL WARMING IS EXPECTED TODAY. SO WILL RAISE MAX TEMPERATURES A LITTLE IN THE TOL TO FDY AREA. THERE STILL IS A QUESTION OF WHETHER OR NOT SOME CONVECTION MAY DROP SOUTH FROM MICHIGAN AND ONTARIO LATE THIS AFTERNOON. THE HRRR EVEN DEVELOPS CONVECTION OVER NW PA AND SW NY BUT FOR NOW WILL KEEP THE FORECAST DRY. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... PLENTY OF UNCERTAINTY FOR CONVECTIVE DEVELOPMENT FOR THE SHORT TERM PERIOD AS WE WATCH FOR OUTFLOW BOUNDARIES TO PUSH A WEAK COLD FRONT TOWARD LAKE ERIE TONIGHT INTO FRIDAY. IF THESE BOUNDARIES REMAIN NORTH OF LAKE ERIE IT WILL REMAIN HOT WITH A DECENT CAP ACROSS THE REGION EVEN AS LOW LEVEL MOISTURE INCREASES. THE UNCERTAINTY FOR THE WEEKEND WILL BE HOW MUCH CONVECTIVE DEBRIS WILL OCCUR. THIS MAY HAVE AN IMPACT ON HIGH TEMPERATURES AND THE AMOUNT OF CAPE AVAILABLE FOR THUNDERSTORMS. THE BEST CHANCES OF THUNDER WILL BE SATURDAY AFTERNOON INTO SUNDAY. SUNDAY S A BIT UNCERTAIN WITH BECAUSE OF THE TIMING OF A STRONGER COLD FRONT INTO NORTHERN OHIO. THE TIMING OF THIS FRONT WILL HAVE SIGNIFICANT IMPACTS ON SEVERE THUNDERSTORM CHANCES FOR THE COUNTY WARNING AREA. IT WILL REMAIN HOT INTO THE WEEKEND. AS STATED ABOVE CLOUD COVER WILL LIKELY BE AN ISSUE FOR HIGHS SATURDAY INTO SUNDAY AND COULD KEEP THE AREA SLIGHTLY COOLER THAN CURRENT THINKING. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... BEGINNING MONDAY A COLD FRONT WILL PUSH EAST OF THE AREA WITH HIGH PRESSURE BRINGING DRY WEATHER AND NEAR SEASONABLE TEMPERATURES TO THE AREA. GFS AND 00Z ECMWF QUIET A BIT DIFFERENT BY LATE IN THE PERIOD WITH ECMWF QUICKER IN BRINGING NEXT COLD FRONT THROUGH THE AREA ON WEDNESDAY. GFS SLOWER AND BRINGING FRONT ACROSS LATE NEXT WEEK. GIVEN RECENT CONDITIONS AND PREVIOUS FORECAST WILL LEAN TOWARD THE GFS WITH WARMING TEMPS AND THE FRONT NOT PUSHING THROUGH THE AREA UNTIL LATE WEEK. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... HIGH PRESSURE WILL ALLOW FOR VFR CONDITIONS TO CONTINUE TODAY. SOME MID AND HIGH CLOUDS WILL SPREAD ACROSS MAINLY NORTHERN SITES FROM TOL-CLE-ERI TODAY BUT EXPECTING ALL PRECIP TO REMAIN NORTH OF THE AREA. THE LIGHT GRADIENT WILL ALLOW FOR A LAKE BREEZE AT ERI AND EVEN CLE LATER IN AFTERNOON. THE WEAK COLD FRONT WILL MOVE OVER LAKE ERIE TONIGHT BUT WITH THE EXCEPTION OF ERI WHICH IT WILL BE IN PROXIMITY THE REMAINDER OF SITES SHOULD REMAIN SOUTH OF THE FRONT. MODELS TRYING AGAIN TO SHOW SOME WIDESPREAD MVFR VIS DEVELOPING LATE TONIGHT...BUT GIVEN PAST TRENDS WITH MODELS WILL HOLD OFF ON MENTIONING MVFR FOR NOW. .OUTLOOK...NON VFR PROBABLE IN SCATTERED THUNDERSTORMS MAINLY SATURDAY THROUGH SUNDAY. && .MARINE... HIGH PRESSURE WILL KEEP CONDITIONS ON THE LAKE QUIET TODAY. A COLD FRONT WILL MOVE SOUTH TOWARD THE LAKE LATE TODAY AND TONIGHT...AND THE BOUNDARY WILL BECOME STATIONARY NEAR THE LAKE THROUGH FRIDAY AND PERHAPS EVEN THROUGH SATURDAY WITH SOUTHEAST FLOW. THE FRONT WILL MOVE BACK NORTH LATER IN THE WEEKEND ALLOW FOR MAINLY SOUTH TO SOUTHWEST WINDS. LOW PRESSURE IS EXPECTED TO TRACK OVER THE NORTHERN GREAT LAKES SUNDAY NIGHT AND EARLY MONDAY...AND THE COLD FRONT WITH THE LOW WILL CROSS THE LAKE. SUNDAY NIGHT THROUGH MONDAY WILL BE THE NEXT OPPORTUNITY FOR SMALL CRAFT ADVISORY HEADLINES WITH WINDS SHIFTING NW AND INCREASING TOWARD 20 KNOTS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...MULLEN NEAR TERM...REL SHORT TERM...MULLEN LONG TERM...ABE AVIATION...ABE MARINE...ABE
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
840 PM CDT FRI AUG 3 2012 .UPDATE... SEVERAL LARGE WILDFIRES CONTINUE ACROSS PARTS OF THE CWA THIS EVENING. WINDS EXPECTED TO REMAIN SOUTH AT 10 TO 15 MPH OVERNIGHT ACROSS MUCH OF THE AREA. AN OUTFLOW BOUNDARY THAT WAS EXTENDED ACROSS PORTIONS OF NORTHERN OK CONTINUES TO SLOWLY LIFT NORTH. SHOWERS AND THUNDERSTORMS MOVING ACROSS THE PANHANDLES ARE MOVING INTO NW PORTIONS OF THE FA THIS EVENING. SHOWERS/STORMS WILL REMAIN POSSIBLE IN THIS AREA THROUGH THIS EVENING. INCREASED POPS TO ACCOUNT FOR THE CURRENT ACTIVITY. WILL SEND UPDATES SHORTLY. MAXWELL && .PREV DISCUSSION... /ISSUED 322 PM CDT FRI AUG 3 2012/ DISCUSSION... ONGOING CRITICAL FIRE WEATHER CONDITIONS AND RECORD BREAKING HEAT ARE THE MAIN CONCERNS. HEAT ADVISORY IS IN GREAT SHAPE AND WILL NOT ALTER. THROUGH TONIGHT...WINDS WILL STAY UP IN THE 10 TO 15 MPH OVER MUCH OF THE AREA...THOUGH THE STRONGEST GUSTS SHOULD DIMINISH BETWEEN 6 AND 9 PM CDT. KEPT 20 PERCENT FOR SHOWERS AND STORMS OVER NORTHERN OKLAHOMA...MAINLY NORTH OF AN ARNETT TO STILLWATER LINE WHERE CAP IS WEAKEST. LATEST HRRR INDICATED NEW DEVELOPMENT THIS EVENING IN FAR NORTHWEST OKLAHOMA. GUSTY WINDS IS THE MAIN HAZARD WITH ANY STORM DUE TO HIGH CLOUD BASES. SATURDAY WILL BE ANOTHER VERY HOT DAY...THOUGH MAY BE SLIGHTLY COOLER DUE TO SLIGHTLY COOLER LOW LEVEL TEMPERATURES. A WEAK FRONT WILL PUSH INTO NORTHERN OKLAHOMA DURING THE AFTERNOON AND EVENING HOURS WHICH MAY ALLOW FOR ISOLATED STORM DEVELOPMENT...SO KEPT 20 PERCENT CHANCES IN THESE AREAS. SUNDAY THROUGH NEXT FRIDAY...DRY AND HOT CONDITIONS WILL LIKELY CONTINUE. TEMPERATURES WILL BE COOLER DURING THIS TIME FRAME...ESPECIALLY ON SUNDAY AS SOME LOCATIONS MAY NOT REACH 100 DEGREES. CANNOT COMPLETELY RULE OUT A FEW STORMS SUNDAY AND MONDAY...BUT KEPT A DRY FORECAST DUE TO LOW CONFIDENCE OF OCCURRENCE. MBS FIRE WEATHER... CURRENT RED FLAG WARNING IS IN GOOD SHAPE AND CONTINUES UNTIL 10 PM CDT. GUSTY SOUTH TO SOUTHWEST WINDS WILL DIMINISH SLIGHTLY BETWEEN 6 AND 9 PM CDT AND SHIFT MAINLY TO THE SOUTH. LOCATIONS NORTH OF A WEAK OUTFLOW BOUNDARY FROM PUTNAM TO CHANDLER HAVE A LOWER CHANCE FOR FIRE IGNITIONS. UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG WARNING FOR THE SAME AREAS ON SATURDAY DUE TO VERY SIMILAR FORECAST CONDITIONS. WINDS MAY BE A NUDGE STRONGER ON SATURDAY COMPARED TO TODAY. LIGHTER WINDS AND COOLER TEMPERATURES WILL ALLOW FOR SLIGHTLY LOWER WILDFIRE POTENTIAL SUNDAY INTO NEXT WEEK. CLIMATE... OKLAHOMA CITY HAS ALREADY REACHED 112 DEGREES TODAY SETTING A NEW DAILY RECORD. THE ALL TIME RECORD OF 113 DEGREES MAY BE TIED OR EXCEEDED IN THE NEXT FEW HOURS. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 83 109 74 99 / 0 10 10 10 HOBART OK 79 109 75 99 / 0 0 10 10 WICHITA FALLS TX 79 110 77 105 / 0 0 0 10 GAGE OK 74 100 66 95 / 40 20 30 10 PONCA CITY OK 78 110 69 98 / 10 20 30 10 DURANT OK 78 107 77 102 / 0 0 0 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING UNTIL 10 PM CDT THIS EVENING FOR OKZ008-012-013- 016>047-050-051. RED FLAG WARNING FROM 10 AM TO 10 PM CDT SATURDAY FOR OKZ008-012- 013-016>047-050-051. HEAT ADVISORY UNTIL 11 PM CDT SATURDAY FOR OKZ004>048-050>052. TX...RED FLAG WARNING UNTIL 10 PM CDT THIS EVENING FOR TXZ083>090. RED FLAG WARNING FROM 10 AM TO 10 PM CDT SATURDAY FOR TXZ083>090. HEAT ADVISORY UNTIL 11 PM CDT SATURDAY FOR TXZ083>090. && $$ 25/30
AREA FORECAST DISCUSSION
NWS TULSA OK
344 PM CDT THU AUG 2 2012 .DISCUSSION... ANOTHER OUTFLOW BOUNDARY STRIKES AGAIN. CONVECTION OVER KANSAS ONCE AGAIN SENT AN OUTFLOW BOUNDARY DOWN INTO OKLAHOMA EARLY THIS MORNING...AND IT HAS HAD SOME AFFECT ON TEMPS TODAY. BECAUSE OF THIS...IT DOES NOT APPEAR THAT THE ALL-TIME TEMP RECORD WILL BE REACHED AT TULSA. THE LATEST RUNS OF THE HRRR SUGGEST SOME ISOLATED TO WIDELY SCATTERED STORMS COULD DEVELOP ALONG THE EAST- WEST ORIENTED LOW LVL TROUGH/CONVERGENT ZONE LATE THIS AFTERNOON AND THIS EVENING. OTHER ELEVATED STORMS COULD DEVELOP ON THE EDGE OF THE CAP LATE TONIGHT TO OUR EAST. NAM MODEL 850MB DATA SUGGESTS THAT FRIDAY WILL BE ANOTHER SCORCHER...WITH HIGHS NEAR 110...ALTHOUGH CONVECTIVE OUTFLOW COULD AFFECT THIS LIKE IT HAS THE PAST COUPLE OF DAYS. SATURDAY IS SHAPING UP TO BE HOTTER DUE TO SOME COMPRESSIONAL WARMING AHEAD OF AN APPROACHING FRONT. SW WINDS WILL BE STRONGER AS WELL...AND THIS WILL REALLY INCREASE FIRE WEATHER CONCERNS. THE HEAT HEADLINES WILL CONTINUE ON THROUGH FRIDAY...HOWEVER THIS MAY NEED TO BE EXTENDED INTO SATURDAY IN LATER FORECASTS. STORMS THAT FORM ALONG THE FRONT IN KANSAS SATURDAY MAY MAKE THEIR WAY DOWN INTO OKLAHOMA AND ARKANSAS LATE SATURDAY AND SATURDAY NIGHT. MUCH COOLER...RELATIVELY SPEAKING...850MB TEMPS...MORE CLOUDS...AND HIGHER HUMIDITY WILL YIELD HIGHS BELOW 100 DEGREES ON SUNDAY. TEMPS WARM BACK UP NEXT WEEK INTO THE 100S...HOWEVER IT DOES APPEAR THAT THE REBUILDING RIDGE AND RESULTING HEAT WILL NOT BE AS INTENSE THIS GO AROUND. THERE MAY BE ANOTHER WEAK BOUNDARY BY NEXT THURSDAY OR SO...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INSERT POPS JUST YET. LACY && .PRELIMINARY POINT TEMPS/POPS... TUL 85 110 86 108 / 10 20 10 20 FSM 79 105 79 102 / 20 20 10 20 MLC 79 107 81 105 / 10 10 10 10 BVO 74 108 76 108 / 20 20 20 30 FYV 76 104 77 100 / 30 20 10 20 BYV 75 101 76 101 / 30 30 20 20 MKO 80 109 80 107 / 10 20 10 20 MIO 77 104 79 104 / 30 20 20 30 F10 80 112 79 107 / 10 10 10 10 HHW 78 104 78 99 / 10 10 10 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR OKZ054-OKZ055- OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-OKZ063- OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-OKZ071- OKZ072-OKZ073-OKZ074. HEAT ADVISORY UNTIL 7 PM FRIDAY FOR OKZ049-OKZ053-OKZ075-OKZ076. AR...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR ARZ001-ARZ010- ARZ019-ARZ029. HEAT ADVISORY UNTIL 7 PM FRIDAY FOR ARZ002-ARZ011-ARZ020. && $$ LONG TERM....30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
352 PM EDT THU AUG 2 2012 .SYNOPSIS... WEAK HIGH PRESSURE WILL DOMINATE THE WEATHER THROUGH FRIDAY. A SOUTHWEST FLOW OF MORE HUMID AIR WILL DEVELOP FOR THE UPCOMING WEEKEND. A COLD FRONT WILL MOVE IN LATE SUNDAY OR EARLY MONDAY. THERE WILL BE A CHANCE OF SHOWERS OR STORMS...MAINLY THE LATER PART OF SUNDAY INTO EARLY MONDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... LOW CLOUDS BURNED OFF NICELY ALLOWING US TO HEAT RAPIDLY TO OUR CONVECTIVE TEMP. AT THIS HOUR WE EVEN HAVE A FEW ISOLATED STORMS POPPING OFF OVER MY SERN ZONES WHERE RAP CAPES ARE ANALYZED OVER 3000J AND DEWPOINTS REMAIN NEAR 70 DEG. THE STORMS ARE FORMING ON THE BACK EDGE OF THE DEEPEST MOISTURE AND MOVING EAST...SO NOT EXPECTED TO AFFECT MORE THAN A FEW COUNTIES WITH LOCALIZED DOWNPOUR. AFTER THE SPOTTY CONVECTION DIES WITH THE LOSS OF HEATING...THE OVERNIGHT TONIGHT WILL ONCE AGAIN BE FAIR WITH SOME PATCHY FOG FORMING AROUND OR AFTER MIDNIGHT. LOWS IN THE 50S AND 60S WILL AVERAGE SEVERAL DEG ABOVE NORMAL. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... DRY WEATHER AND GENERALLY PTLY CLOUDY SKIES WITH LIGHT WIND WILL PERSIST THROUGH MOST OR ALL OF THIS PERIOD. THE NEARLY EAST/WEST AXIS OF STEEP MID LEVEL LAPSE RATES WILL STRETCH ACROSS THE NRN MTNS OF PENN FRIDAY AFTERNOON/EVENING. WEAK LLVL CONVERGENCE/OROGRAPHIC LIFT COULD SPARK A FEW TSRA AFTER 18Z...BUT AREAL COVERAGE IS ANTICIPATED TO BE QUITE LOW. HIGHS FRIDAY WILL TOP 90 OVER A GOOD DEAL OF THE AREA. AT THIS STAGE THE DEWPOINTS ARE JUST LOW ENOUGH TO NOT ALLOW HEAT INDICES TO TOP 100...BUT IT WILL BE CLOSE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... NOT A LOT OF CHANGE FROM RECENT DAYS. MAIN THING WAS TO UP TEMPS SOME ON MANY OF THE PERIODS...EVEN WITH THE RAINFALL...MAX TEMPS LIKELY TO BE WARMER THAN FCST. GFS HAS CLOSE TO A 579 THICKNESS ACROSS SE PA SUNDAY AFT. ALSO GUIDANCE MIN TEMPS BEEN TOO COLD LATELY...BFD LAST NIGHT WAS AN EXAMPLE OF THIS. SOME CHC FOR A SHOWER OR TSRA ACROSS THE AREA FRIDAY NIGHT... AND AGAIN LATER SATURDAY NIGHT AS THE BOUNDARY TO OUR SOUTH GRADUALLY RETURNS NORTH AS A WARM FRONT...AND THE FAVORABLE LEFT EXIT REGION OF AN UPPER JET HEADS SE FROM THE GLAKES REGION. BEST CHC FOR SEVERE SUNDAY WILL BE NORTH CENTRAL PA AND THE SUSQUEHANNA VLY. NORTHERN PA WILL BE NEAR THE SOUTHERN EDGE OF THE BETTER DYANMICS. ACROSS EASTERN PA...THE LEE TROUGH WILL LIKELY TO FORM IN EASTERN PA...AIDING THE FORMATION OF STORMS SUNDAY AFTERNOON AND EVENING. I DID SLOW TIMING OF FRONT DOWN SOME...THUS A LITTLE MORE CLDS AND THREAT OF SHOWERS AND STORMS INTO MONDAY ACROSS S PA. NOT SEEING MUCH OF A COOL DOWN FOR NEXT WEEK...TEMPS NEAR OR JUST ABOVE NORMAL. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... ALL SITES HAVE IMPROVED TO VFR AND WILL REMAIN THAT WAY INTO THE OVERNIGHT. ONLY POSSIBLE COMPLICATION IS IF A STRAY STORM POPS UP NEAR OUR SERN TERMINALS FOR THE NEXT FEW HOURS. THE ACTIVITY IS VERY ISOLATED SO PROBABILITIES WILL BE LOW. OVERNIGHT WILL ONCE AGAIN FEATURE PATCHY FOG AND LOW CLOUDS WITH SOME MVFR/IFR POSSIBLE...ESPECIALLY AROUND SUNRISE. EXPECT RAPID IMPROVEMENT TO VFR BY MID MORNING FRIDAY UNDER THE STRONG SUMMER SUN. ONLY CONCERN FOR FRIDAY WILL BE THE POTENTIAL FOR MORE ISOLATED POP UP DIURNAL CONVECTION. NO REAL WEATHER FEATURE PASSING THROUGH SO IT WILL BE BASICALLY DAY TIME HEATING AS A TRIGGER. OUTLOOK... .FRI-SUN...MAINLY VFR...BUT WITH DIURNAL CONVECTION POSSIBLY CAUSING LOCALIZED REDUCED CONDITIONS...MAINLY THE LATER HALF OF SUNDAY .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
203 PM EDT THU AUG 2 2012 .SYNOPSIS... WEAK HIGH PRESSURE WILL DOMINATE THE WEATHER THROUGH FRIDAY. A SOUTHWEST FLOW OF MORE HUMID AIR WILL DEVELOP FOR THE UPCOMING WEEKEND. A COLD FRONT WILL MOVE IN LATE SUNDAY OR EARLY MONDAY. THERE WILL BE A CHANCE OF SHOWERS OR STORMS...MAINLY THE LATER PART OF SUNDAY INTO EARLY MONDAY. && .NEAR TERM /THROUGH TONIGHT/... LOW CLOUDS BURNED OFF NICELY ALLOWING US TO HEAT RAPIDLY TO OUR CONVECTIVE TEMP. AT THIS HOUR WE EVEN HAVE A FEW ISOLATED STORMS POPPING OFF OVER MY SERN ZONES WHERE RAP CAPES ARE ANALYZED OVER 3000J AND DEWPOINTS REMAIN NEAR 70 DEG. THE STORMS ARE FORMING ON THE BACK EDGE OF THE DEEPEST MOISTURE AND MOVING EAST...SO NOT EXPECTED TO AFFECT MORE THAN A FEW COUNTIES WITH LOCALIZED DOWNPOUR. AFTER THE SPOTTY CONVECTION DIES WITH THE LOSS OF HEATING...THE OVERNIGHT TONIGHT WILL ONCE AGAIN BE FAIR WITH SOME PATCHY FOG FORMING AROUND OR AFTER MIDNIGHT. LOWS IN THE 50S AND 60S WILL AVERAGE SEVERAL DEG ABOVE NORMAL. && .SHORT TERM /FRIDAY/... DRY WEATHER AND GENERALLY PTLY CLOUDY SKIES WITH LIGHT WIND WILL PERSIST THROUGH MOST OR ALL OF THIS PERIOD. THE NEARLY EAST/WEST AXIS OF STEEP MID LEVEL LAPSE RATES WILL STRETCH ACROSS THE NRN MTNS OF PENN FRIDAY AFTERNOON/EVENING. WEAK LLVL CONVERGENCE/OROGRAPHIC LIFT COULD SPARK A FEW TSRA AFTER 18Z...BUT AREAL COVERAGE IS ANTICIPATED TO BE QUITE LOW. HIGHS FRIDAY WILL TOP 90 OVER A GOOD DEAL OF THE AREA. AT THIS STAGE THE DEWPOINTS ARE JUST LOW ENOUGH TO NOT ALLOW HEAT INDICES TO TOP 100...BUT IT WILL BE CLOSE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... SOME CHC FOR A SHOWER OR TSRA ACROSS THE ENTIRE AREA FRIDAY NIGHT INTO SATURDAY NIGHT AS THE BOUNDARY TO OUR SOUTH GRADUALLY RETURNS NORTH AS A WARM FRONT...AND THE FAVORABLE LEFT EXIT REGION OF AN UPPER JET HEADS SE FROM THE GLAKES REGION. THERE/S A BETTER CHC FOR MORE WIDESPREAD AND STRONGER CONVECTION SATURDAY AFTERNOON AND EVENING...ESPECIALLY ACROSS THE WRN HALF OF PENN WHERE THE LATEST SREF PAINTS SFC-BASED CAPES OF 1500-1800 J/KG COINCIDING WITH A BELT OF ANOMALOUSLY STG SOUTHERLY 850 MB WINDS OF PLUS 2-3 ST DEVIATIONS. THIS SRLY LL JET PEAKS AROUND 30 KTS AT 03Z SUNDAY BEFORE LIFTING NORTH INTO NEW YORK STATE LATER SUNDAY MORNING. A SHARP INCREASE IN LLVL MOISTURE/PRECIPITABLE WATER WILL OCCUR LATE FRIDAY NIGHT THROUGH SATURDAY. PWATS WILL AVERAGE 1.5-2 INCHES ACROSS THE STATE SATURDAY AFTERNOON AND EVENING. THE ASSOCIATED 850 MB MOISTURE FLUX WILL ALSO DISPLAY A STRONG SIGNAL FOR POTENTIALLY SEVERE TSRA AS IT REACHES 2-3 ST DEVIATIONS ABOVE NORMAL ACROSS ALL OF THE FCST AREA AT 00Z SUNDAY. SUNDAY AFTERNOON AND EVENING WILL LIKELY BRING ANOTHER BOUT OF SCTD-NUMEROUS SHOWERS/TSRA...SOME POTENTIALLY SVR AS A STRONG COLD FRONT PLOWS EAST FROM THE OHIO VALLEY. THE CORE OF STRONGER AND SLIGHTLY LESS ANOMALOUS...925-850 MB WINDS SHIFTS TO OUR FAR EASTERN ZONES AND TURNS MORE TO A SWRLY DIRECTION DURING THE DAY SUNDAY . SFC TEMP/DEWPOINT SPREADS ARE PROGGED TO BE APPRECIABLY LOWER SUNDAY...POSSIBLY DUE TO SOME EARLY MORNING CONVECTION/MCS REMNANTS AND LINGERING MORNING/MIDDAY CLOUD COVER. IN ANY CASE...THE TARGET AREA FOR THE GREATEST CONCENTRATION OF TSRA WILL SHIFT TO THE CENTRAL MTNS AND SUSQ VALLEY SUNDAY AFTERNOON AND EVENING...WHERE THE 0-1KM ENERGY/HELICITY INDEX WILL CLIMB TO AROUND 2-2.5 M2/S2. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... ALL SITES HAVE IMPROVED TO VFR AND WILL REMAIN THAT WAY INTO THE OVERNIGHT. ONLY POSSIBLE COMPLICATION IS IF A STRAY STORM POPS UP NEAR OUR SERN TERMINALS FOR THE NEXT FEW HOURS. THE ACTIVITY IS VERY ISOLATED SO PROBABILITIES WILL BE LOW. OVERNIGHT WILL ONCE AGAIN FEATURE PATCHY FOG AND LOW CLOUDS WITH SOME MVFR/IFR POSSIBLE...ESPECIALLY AROUND SUNRISE. EXPECT RAPID IMPROVEMENT TO VFR BY MID MORNING FRIDAY UNDER THE STRONG SUMMER SUN. ONLY CONCERN FOR FRIDAY WILL BE THE POTENTIAL FOR MORE ISOLATED POP UP DIURNAL CONVECTION. NO REAL WEATHER FEATURE PASSING THROUGH SO IT WILL BE BASICALLY DAY TIME HEATING AS A TRIGGER. OUTLOOK... .FRI-SUN...MAINLY VFR...BUT WITH DIURNAL CONVECTION POSSIBLY CAUSING LOCALIZED REDUCED CONDITIONS...MAINLY THE LATER HALF OF SUNDAY .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
803 PM EDT FRI AUG 3 2012 .SYNOPSIS... CIRCULATION AROUND HIGH PRESSURE CENTERED OVER THE WESTERN ATLANTIC WILL KEEP THE SOUTHERN APPALACHIAN REGION WARM AND HUMID THROUGH THE WEEKEND. A COLD FRONT IS EXPECTED TO SLOWLY SWEEP ACROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA EARLY NEXT WEEK...POSSIBLY BECOMING STATIONARY AND LINGERING INTO LATE IN THE WORK WEEK. && .NEAR TERM /THROUGH SATURDAY/... 0000 UTC UPDATE...POPS WERE LOWERED IN THE CENTRAL NC MOUNTAINS WHERE A GAP ION COVERAGE HAS APPEARED. QPF WAS LOWERED IN THE SC FOOTHILLS...AND RAISED IN THE CHARLOTTE AREA. PREVIOUS DISCUSSION...CONVECTION HAS BEGUN TO DEVELOP OVER THE SOUTHWEST AND CENTRAL NC MTNS. LAYER RH VALUES ARE THE HIGHEST IN THIS PART OF THE FORECAST AREA...AND IT/S CLOSET TO THE APPROACHING SHORTWAVE TROUGH WHICH CURRENTLY EXTENDS FROM CENTRAL KY TO ERN TN. THE FEATURE ITSELF IS QUITE WEAK AND THE EFFECTIVE BULK SHEAR ACROSS THE REGION IS WELL UNDER 20 KTS. THEREFORE DIFFERENTIAL HEATING AND LLVL MASS CONVERGENCE SHOULD BE THE MAIN DRIVERS FOR CONVECTION THIS EVENING. THE LATEST HI-RES NUMERICAL MODEL RUNS ARE MORE VARIED THAN WHAT I SAW THIS MORNING. THE WRF-ARW AND THE HRRR BOTH DEVELOP CONVECTION OVER PARTS OF THE FA...BUT IT/S NOT LOOKING AS ORGANIZED AS EARLIER. THE 12 UTC 4KM SPC WRF ON THE OTHER HAND HAS A LARGE AREA OF CONVECTION OVER THE WESTERN UPSTATE AND NE GA THIS EVENING. THE 12 UTC NAM HAS STRONG LLVL CONVERGENCE THIS EVENING AND ALSO DEVELOPS INTENSE SLOW MOVING CONVECTION OVER THE UPSTATE. OVERALL...THE IDEA OF LIKELY POPS SLOWLY SPREADING FROM WEST TO EAST ACROSS THE FA THE REST OF THE AFN AND EVENING STILL LOOKS GOOD. DCAPE VALUES ARE WELL OVER 1000 J/KG ACROSS THE UPSTATE AND NE GA...AND PULSE SEVERE STORMS ARE A GOOD BET AGAIN THIS EVENING. PULSE SEVERE WON/T BE LIKELY OVER THE NC MTNS AND FOOTHILLS...BUT EVEN THOUGH CURRENT DCAPE VALUES AREN/T THAT GREAT...I STILL SUSPECT WE/LL SEE A FEW SEVERE STORMS ALONG THE I-77 URBAN CORRIDOR. VERY HEAVY RAIN IS ALSO POSSIBLE IS SPOTS AND ISOLATED FLASH FLOODING IS POSSIBLE. LATER TONIGHT WIDESPREAD LOW CLOUDS SHOULD DEVELOP ACROSS MOST OF THE FA. ON SATURDAY THE UPPER TROUGH WEAKENS QUICKLY AS THE ATLANTIC RIDGE STARTS TO BUILD BACK INTO THE REGION. THE WEAKENING OF THE TROUGH IS A LITTLE FASTER THAN WHAT WE/D BEEN EXPECTING. LAYER RH/S WILL REMAIN HIGH AND EVEN WITH VERY WEAK FORCING...THERE SHOULD BE PLENTY OF CONVECTION OVER THE HIGH TERRAIN AND A LITTLE LESS OUT ACROSS THE FOOTHILLS AND PIEDMONT. THE SEVERE AND FLOODING RISK DON/T LOOK AS GREAT TOMORROW. INTERESTINGLY...THE STRONGEST FORCING OF THE DAY COULD COME IN THE FORM OF THE SEA-BREEZE FRONT WHICH THE NAM BRINGS INTO THE SE ZONES EARLY IN THE EVENING. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 145 PM EDT...EXPECT SOME ONGOING SCATTERED CONVECTION SATURDAY EVENING TO WANE RATHER QUICKLY AS SUBTROPICAL RIDGE BUILDS WESTWARD INTO THE AREA SAT NIGHT. HENCE...THE SAT OVERNIGHT THROUGH SUNDAY MORNING IS EXPECTED TO BE TRANQUIL. ON SUNDAY AFTERNOON...UPSLOPE FLOW AND THE APPROACH OF A WEAK COLD FRONT FROM THE NW SHOULD TRIGGER SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS ACROSS THE MOUNTAINS. ONLY ISOLATED TO WIDELY SCATTERED ACTIVITY IS EXPECTED ELSEWHERE. THE MODELS BRING THE FRONTAL BOUNDARY INTO THE MOUNTAINS SUNDAY NIGHT WHICH NECESSITATES MAINTAINING AT LEAST SCATTERED POPS THERE. ON MONDAY...THE FRONT IS FORECAST TO LAY OUT ACROSS THE WESTERN CAROLINAS INTO NE GA WHICH SHOULD BE A FOCAL POINT FOR SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. MAXIMUM TEMPERATURES ARE EXPECTED TO BE NEAR CLIMO WITH MIN TEMPERATURES ABOUT A CATEGORY ABOVE AVERAGE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 1 PM EDT FRIDAY...THE MEDIUM RANGE IS EXPECTED TO FEATURE SOME DEGREE OF BROAD UPPER TROFFING OVER THE EASTERN U.S. WITH PERHAPS SOME AMPLIFICATION IN THE TROUGH TOWARD THE END OF THE PERIOD. THE PERSISTENT TROUGH AND THE PRESENCE OF THE FRONT WILL CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS THROUGH TUE...WITH AN UPTICK DURING THE FAVORED AFTERNOON AND EVENING TIME PERIOD. THERE IS SOME DIVERGENCE IN THE GUIDANCE IN REGARD TO HOW FAR SOUTH THE AFOREMENTIONED FRONT GOES. THE ECM CAMP TAKES THE FRONTAL BOUNDARY JUST SOUTH OF THE AREA ON WED AND BRINGS SOMEWHAT DRYER INTO THE REGION FOR WED INTO THU. THIS WOULD PRODUCE A DECREASE IN SHOWER/THUNDERSTORM ACTIVITY FOR WED INTO THU. ON THE OTHER HAND... THE GFS HANGS UP THE BOUNDARY OVER THE AREA THROUGH THE PERIOD WITH A CONTINUATION OF ENHANCED SHOWER AND THUDNERSTORM ACTIVITY THROUGH THE END OF THE WEEK. HPC SIDED WITH THE ECM FRONTAL POSITION. WE GENERALLY STAYED CLOSE TO HPC GUIDANCE WITH HIGHER THAN CLIMO POPS FOR TUE AND THEN SOMEWHAT LOWER THAN CLIMO...ESPECIALLY ACROSS THE MOUNTAINS FOR WED. BASICALLY CLIMO POPS RETURN FOR THE END OF THE WEEK. USED A BLEND OF HPC/GMOS FOR TEMPS WHICH ESSENTIALLY IS CLOSE TO CLIMO. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... AT KCLT...CONVECTIVE ACTIVITY IS EXPECTED TO CONTINUE NEAR THE FIELD FOR SEVERAL HOURS THIS EVENING AS A MID LEVEL SYSTEM CROSSES THE EAST COAST...POSSIBLY ACCOMPANIED BY MVFR CIG AND VSBY. OTHERWISE... LOW VFR CIGS ARE EXPECTED UNTIL EARLY MORNING...WHEN GUIDANCE SUGGEST IFR CIGS IN A MOIST BOUNDARY LAYER. GUIDANCE CIG HEIGHTS WERE RAISED ABOUT 500 FEET FOR CONTINUITY WITH CIGS FROM THIS MORNING...AS CONFIDENCE IS LIMITED IN THE LOW END IFR MODEL CIG. THIS LEAVES KCLT WITH A LOW END MVFR CIG AROUND DAYBREAK. MODEL VSBY WAS MVFR...BUT THE MODELS HAVE BEEN TOO LOW WITH VSBY...AND VFR WILL BE CARRIED FOR NOW. CONVECTIVE CHANCES FOR SATURDAY AFTERNOON ARE HIGH ENOUGH TO CARRY A PROB30. SOUTHERLY WINDS WILL PREVAIL. ELSEWHERE...MOUNTAIN CONVECTION IS EXPECTED TO DEVELOP ACROSS THE MOUNTAINS AND INTO THE FOOTHILLS THIS EVENING...AND MVFR CIG AND VSBY RESTRICTIONS WILL BE POSSIBLE. AFTERWORDS...LOW VFR CIGS CAN BE EXPECTED INTERMITTENTLY UNTIL SEVERAL HOURS BEFORE DAWN. AT THAT POINT MODEL GUIDANCE IS QUITE DIRE WITH CIG HEIGHTS...BUT WITH LOW CONFIDENCE IS SUCH LOW CIGS...A GENERAL IFR WILL BE CARRIED...EXCEPT VFR AT KAND. GUIDANCE FAVORS MVFR VSBY EAST OF THE MOUNTAINS...AND LIFR IN THE MOUNTAIN. BASED ON TRENDS FROM YESTERDAY AND LIMITED CONFIDENCE...IFR WILL BE CARRIED IN THE MOUNTAINS...MVFR ALONG INTERSTATE 40...AND VFR TO THE SOUTH. SATURDAY AFTERNOON CONVECTIVE CHANCES WARRANT PROB30 AT ALL LOCATIONS. WINDS WILL GENERALLY BE FROM THE S OR SE. OUTLOOK...ISO/SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG. AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)... WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...NED NEAR TERM...JAT/MCAVOY SHORT TERM...LG LONG TERM...LG AVIATION...JAT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
718 PM EDT FRI AUG 3 2012 .SYNOPSIS... CIRCULATION AROUND HIGH PRESSURE CENTERED OVER THE WESTERN ATLANTIC WILL KEEP THE SOUTHERN APPALACHIAN REGION WARM AND HUMID THROUGH THE WEEKEND. A COLD FRONT IS EXPECTED TO SLOWLY SWEEP ACROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA EARLY NEXT WEEK...POSSIBLY BECOMING STATIONARY AND LINGERING INTO LATE IN THE WORK WEEK. && .NEAR TERM /THROUGH SATURDAY/... 2330 UTC UPDATE...POPS WERE RAISED ALONG INTERSTATE 85 IN NC PER RADAR TRENDS. QPF WAS LOWERED IN THE FOOTHILLS. SKY COVER WAS UPDATED FORM THE LATEST VISIBLE IMAGERY. WINDS WERE UPDATED WITH A BLEND OF THE 18Z ADJMAV AND 18Z NAM. PREVIOUS DISCUSSION...CONVECTION HAS BEGUN TO DEVELOP OVER THE SOUTHWEST AND CENTRAL NC MTNS. LAYER RH VALUES ARE THE HIGHEST IN THIS PART OF THE FORECAST AREA...AND IT/S CLOSET TO THE APPROACHING SHORTWAVE TROUGH WHICH CURRENTLY EXTENDS FROM CENTRAL KY TO ERN TN. THE FEATURE ITSELF IS QUITE WEAK AND THE EFFECTIVE BULK SHEAR ACROSS THE REGION IS WELL UNDER 20 KTS. THEREFORE DIFFERENTIAL HEATING AND LLVL MASS CONVERGENCE SHOULD BE THE MAIN DRIVERS FOR CONVECTION THIS EVENING. THE LATEST HI-RES NUMERICAL MODEL RUNS ARE MORE VARIED THAN WHAT I SAW THIS MORNING. THE WRF-ARW AND THE HRRR BOTH DEVELOP CONVECTION OVER PARTS OF THE FA...BUT IT/S NOT LOOKING AS ORGANIZED AS EARLIER. THE 12 UTC 4KM SPC WRF ON THE OTHER HAND HAS A LARGE AREA OF CONVECTION OVER THE WESTERN UPSTATE AND NE GA THIS EVENING. THE 12 UTC NAM HAS STRONG LLVL CONVERGENCE THIS EVENING AND ALSO DEVELOPS INTENSE SLOW MOVING CONVECTION OVER THE UPSTATE. OVERALL...THE IDEA OF LIKELY POPS SLOWLY SPREADING FROM WEST TO EAST ACROSS THE FA THE REST OF THE AFN AND EVENING STILL LOOKS GOOD. DCAPE VALUES ARE WELL OVER 1000 J/KG ACROSS THE UPSTATE AND NE GA...AND PULSE SEVERE STORMS ARE A GOOD BET AGAIN THIS EVENING. PULSE SEVERE WON/T BE LIKELY OVER THE NC MTNS AND FOOTHILLS...BUT EVEN THOUGH CURRENT DCAPE VALUES AREN/T THAT GREAT...I STILL SUSPECT WE/LL SEE A FEW SEVERE STORMS ALONG THE I-77 URBAN CORRIDOR. VERY HEAVY RAIN IS ALSO POSSIBLE IS SPOTS AND ISOLATED FLASH FLOODING IS POSSIBLE. LATER TONIGHT WIDESPREAD LOW CLOUDS SHOULD DEVELOP ACROSS MOST OF THE FA. ON SATURDAY THE UPPER TROUGH WEAKENS QUICKLY AS THE ATLANTIC RIDGE STARTS TO BUILD BACK INTO THE REGION. THE WEAKENING OF THE TROUGH IS A LITTLE FASTER THAN WHAT WE/D BEEN EXPECTING. LAYER RH/S WILL REMAIN HIGH AND EVEN WITH VERY WEAK FORCING...THERE SHOULD BE PLENTY OF CONVECTION OVER THE HIGH TERRAIN AND A LITTLE LESS OUT ACROSS THE FOOTHILLS AND PIEDMONT. THE SEVERE AND FLOODING RISK DON/T LOOK AS GREAT TOMORROW. INTERESTINGLY...THE STRONGEST FORCING OF THE DAY COULD COME IN THE FORM OF THE SEA-BREEZE FRONT WHICH THE NAM BRINGS INTO THE SE ZONES EARLY IN THE EVENING. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 145 PM EDT...EXPECT SOME ONGOING SCATTERED CONVECTION SATURDAY EVENING TO WANE RATHER QUICKLY AS SUBTROPICAL RIDGE BUILDS WESTWARD INTO THE AREA SAT NIGHT. HENCE...THE SAT OVERNIGHT THROUGH SUNDAY MORNING IS EXPECTED TO BE TRANQUIL. ON SUNDAY AFTERNOON...UPSLOPE FLOW AND THE APPROACH OF A WEAK COLD FRONT FROM THE NW SHOULD TRIGGER SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS ACROSS THE MOUNTAINS. ONLY ISOLATED TO WIDELY SCATTERED ACTIVITY IS EXPECTED ELSEWHERE. THE MODELS BRING THE FRONTAL BOUNDARY INTO THE MOUNTAINS SUNDAY NIGHT WHICH NECESSITATES MAINTAINING AT LEAST SCATTERED POPS THERE. ON MONDAY...THE FRONT IS FORECAST TO LAY OUT ACROSS THE WESTERN CAROLINAS INTO NE GA WHICH SHOULD BE A FOCAL POINT FOR SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. MAXIMUM TEMPERATURES ARE EXPECTED TO BE NEAR CLIMO WITH MIN TEMPERATURES ABOUT A CATEGORY ABOVE AVERAGE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 1 PM EDT FRIDAY...THE MEDIUM RANGE IS EXPECTED TO FEATURE SOME DEGREE OF BROAD UPPER TROFFING OVER THE EASTERN U.S. WITH PERHAPS SOME AMPLIFICATION IN THE TROUGH TOWARD THE END OF THE PERIOD. THE PERSISTENT TROUGH AND THE PRESENCE OF THE FRONT WILL CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS THROUGH TUE...WITH AN UPTICK DURING THE FAVORED AFTERNOON AND EVENING TIME PERIOD. THERE IS SOME DIVERGENCE IN THE GUIDANCE IN REGARD TO HOW FAR SOUTH THE AFOREMENTIONED FRONT GOES. THE ECM CAMP TAKES THE FRONTAL BOUNDARY JUST SOUTH OF THE AREA ON WED AND BRINGS SOMEWHAT DRYER INTO THE REGION FOR WED INTO THU. THIS WOULD PRODUCE A DECREASE IN SHOWER/THUNDERSTORM ACTIVITY FOR WED INTO THU. ON THE OTHER HAND... THE GFS HANGS UP THE BOUNDARY OVER THE AREA THROUGH THE PERIOD WITH A CONTINUATION OF ENHANCED SHOWER AND THUDNERSTORM ACTIVITY THROUGH THE END OF THE WEEK. HPC SIDED WITH THE ECM FRONTAL POSITION. WE GENERALLY STAYED CLOSE TO HPC GUIDANCE WITH HIGHER THAN CLIMO POPS FOR TUE AND THEN SOMEWHAT LOWER THAN CLIMO...ESPECIALLY ACROSS THE MOUNTAINS FOR WED. BASICALLY CLIMO POPS RETURN FOR THE END OF THE WEEK. USED A BLEND OF HPC/GMOS FOR TEMPS WHICH ESSENTIALLY IS CLOSE TO CLIMO. && .AVIATION /23Z FRIDAY THROUGH WEDNESDAY/... AT KCLT...CONVECTIVE ACTIVITY IS EXPECTED TO CONTINUE NEAR THE FIELD FOR SEVERAL HOURS THIS EVENING AS A MID LEVEL SYSTEM CROSSES THE EAST COAST...POSSIBLY ACCOMPANIED BY MVFR CIG AND VSBY. OTHERWISE... LOW VFR CIGS ARE EXPECTED UNTIL EARLY MORNING...WHEN GUIDANCE SUGGEST IFR CIGS IN A MOIST BOUNDARY LAYER. GUIDANCE CIG HEIGHTS WERE RAISED ABOUT 500 FEET FOR CONTINUITY WITH CIGS FROM THIS MORNING...AS CONFIDENCE IS LIMITED IN THE LOW END IFR MODEL CIG. THIS LEAVES KCLT WITH A LOW END MVFR CIG AROUND DAYBREAK. MODEL VSBY WAS MVFR...BUT THE MODELS HAVE BEEN TOO LOW WITH VSBY...AND VFR WILL BE CARRIED FOR NOW. CONVECTIVE CHANCES FOR SATURDAY AFTERNOON ARE HIGH ENOUGH TO CARRY A PROB30. SOUTHERLY WINDS WILL PREVAIL. ELSEWHERE...MOUNTAIN CONVECTION IS EXPECTED TO DEVELOP ACROSS THE MOUNTAINS AND INTO THE FOOTHILLS THIS EVENING...AND MVFR CIG AND VSBY RESTRICTIONS WILL BE POSSIBLE. AFTERWORDS...LOW VFR CIGS CAN BE EXPECTED INTERMITTENTLY UNTIL SEVERAL HOURS BEFORE DAWN. AT THAT POINT MODEL GUIDANCE IS QUITE DIRE WITH CIG HEIGHTS...BUT WITH LOW CONFIDENCE IS SUCH LOW CIGS...A GENERAL IFR WILL BE CARRIED...EXCEPT VFR AT KAND. GUIDANCE FAVORS MVFR VSBY EAST OF THE MOUNTAINS...AND LIFR IN THE MOUNTAIN. BASED ON TRENDS FROM YESTERDAY AND LIMITED CONFIDENCE...IFR WILL BE CARRIED IN THE MOUNTAINS...MVFR ALONG INTERSTATE 40...AND VFR TO THE SOUTH. SATURDAY AFTERNOON CONVECTIVE CHANCES WARRANT PROB30 AT ALL LOCATIONS. WINDS WILL GENERALLY BE FROM THE S OR SE. OUTLOOK...ISO/SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG. AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)... WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...NED NEAR TERM...JAT/MCAVOY SHORT TERM...LG LONG TERM...LG AVIATION...JAT
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
819 PM MDT FRI AUG 3 2012 .UPDATE...THE SHOWERS MOVING THROUGH NORTHEAST WYOMING HAVE BECOME SLIGHTLY MORE INTENSE DURING THE PAST COUPLE OF HOURS...BUT LIGHTNING IS STILL VERY SPARSE. MEANWHILE THE POSSIBILITY OF CONVECTION DEVELOPING NORTH OF THE FRONT IN NORTH CENTRAL NEBRASKA MENTIONED IN THE PREVIOUS UPDATE HAS NOT OCCURRED. THE 00Z KUNR SOUNDING SHOWS A VERY STRONG POST FRONTAL SUBSIDENCE INVERSION WHICH WOULD PRECLUDE ANY SIGNIFICANT DEVELOPMENT. && .PREV DISCUSSION... /ISSUED 536 PM MDT FRI AUG 3 2012/ UPDATE...KEEPING AN EYE ON THE CONVECTIONS ALONG THE COLD FRONT IN NORTH CENTRAL NEBRASKA THIS AFTERNOON. THE HRRR SHOWS SOME OF THIS DEVELOPING NORTHWARD ACROSS THE SOUTH DAKOTA BORDER LATER THIS EVENING WHEN A STRONG VORTICITY LOBE ROTATES AROUND THE MAIN UPPER LOW THROUGH SOUTH CENTRAL SOUTH DAKOTA. AVIATION...00Z TAFS AN AREA OF SCT SHRA IS MOVING INTO NORTHEASTERN WYOMING THIS AFTERNOON. CIGS AND VSBYS HAVE NOT BEEN BELOW MVFR IN THE PRECIP...BUT SOMEWHAT LOWER CONDITIONS COULD DEVELOP AS IT MOVES INTO NORTHERN CAMPBELL COUNTY WITH THE UPSLOPE SURFACE FLOW. ELSEWHERE THE STRONGEST AFTERNOON CONVECTION IS CONFINED TO EASTERN PARTS OF SOUTH DAKOTA AND NROTH CENTRAL NEBRASKA. MVFR CONDITIONS POSSIBLE IN HEAVIER STORMS. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THE EVENING. GUSTY NORTHWEST WINDS TO 35 KTS WILL CONTINUE TO GRADUALLY SUBSIDE DURING THE EVENING HOURS. GUSTY NORTHWEST WINDS ARE EXPECTED AGAIN SATURDAY. PREV DISCUSSION... /ISSUED 253 PM MDT FRI AUG 3 2012/ DISCUSSION...UPPER LEVEL ANALYSIS HAS LOW PRESSURE OVER FAR SOUTHWESTERN SK MOVING SLOWLY EASTWARD...WITH SOUTHWESTERLY FLOW AHEAD OF IT ACROSS THE NORTHERN PLAINS. CURRENT SURFACE ANALYSIS SHOWS COLD FRONT STRETCHING FROM NORTHEASTERN ND THROUGH CENTRAL SD AND INTO THE NEBRASKA PANHANDLE. TIGHTENING PRESSURE GRADIENT BEHIND THE FRONT IS PRODUCING GUSTY NORTH TO NORTHWEST WINDS ACROSS MUCH OF THE WESTERN SD PLAINS. THE STRONGEST WINDS ARE IN THE RAPID CITY AREA...WHERE A FEW GUSTS TO AROUND 50 MPH HAVE BEEN NOTED. SKIES RANGE FROM MOSTLY CLOUDY ACROSS FAR NORTHEASTERN WY AND NORTHWESTERN SD TO MOSTLY SUNNY ACROSS SOUTHERN SD. MAIN BAND OF SHOWERS AND THUNDERSTORMS IS STAYING NORTH OF THE CWA SO FAR...CLOSER TO THE UPPER LOW. THUNDERSTORMS HAVE ALSO DEVELOPED ALONG THE FRONT FROM CENTRAL ND INTO NORTH CENTRAL SD. TEMPS CURRENTLY RANGE FROM THE UPPER 60S ACROSS PORTIONS OF NORTHEASTERN WY AND NORTHWESTERN SD...TO THE 90S OVER SOUTH CENTRAL SD. COLD FRONT WILL MOVE SLOWLY EAST ACROSS CENTRAL SD LATE THIS AFTERNOON AND INTO EASTERN SD THIS EVENING. UPPER LOW WILL TRACK EAST ACROSS FAR SOUTHERN SK THROUGH TONIGHT. GUSTY WINDS WILL CONTINUE THROUGH THE LATE AFTERNOON AND THEN GRADUALLY DECREASE THIS EVENING. THE BEST CHANCES FOR SHOWERS AND STORMS WILL BE ALONG THE FRONT ACROSS CENTRAL SD LATE THIS AFTERNOON INTO TONIGHT. SUFFICIENT INSTABILITY AND SHEAR REMAINS ALONG AND AHEAD OF THE FRONT ACROSS FAR SOUTH CENTRAL SD TO ALLOW FOR A THREAT OF A SEVERE THUNDERSTORM OR TWO OVER THE NEXT HOUR OR TWO. HOWEVER...THE BETTER THREAT FOR SEVERE STORMS WILL CLEARLY BE ACROSS EASTERN SD THROUGH THIS EVENING. STRONG WIND GUSTS WOULD BE THE MAIN THREAT FROM ANY SEVERE STORMS...BUT LARGE HAIL IS ALSO A POSSIBILITY. A FEW SHOWERS AND STORMS ARE ALSO POSSIBLE OVER NORTHEASTERN WY AND SOUTHWESTERN SD LATE THIS AFTERNOON INTO THIS EVENING AS WEAK SHORTWAVE ENERGY CROSSES ON THE SOUTHERN SIDE OF THE TROF AND INTERACTS WITH WEAK INSTABILITY REMAINING OVER THE AREA. THE POSSIBILITY FOR SHOWER COULD LINGER ACROSS SOUTH CENTRAL SD OVERNIGHT AS THE BACK END OF THE WAVE CROSSES. TEMPS WILL BE PLEASANTLY COOL IN MOST AREAS OVERNIGHT...WITH LOWS MOSTLY IN THE 50S...SOME 40S OVER THE BLACK HILLS AND NORTHEASTERN WY. THE WEEKEND LOOKS TO BE VERY NICE WITH MOSTLY CLEAR SKIES EXPECTED. TEMPS WILL BE PLEASANTLY COOL ON SATURDAY...WITH HIGHS IN THE 70S AND LOWER 80S AS CANADIAN HIGH PRESSURE MOVES INTO THE AREA LATE IN THE DAY. BREEZY NORTHWESTERLY WINDS CAN BE EXPECTED DURING THE LATE MORNING AND EARLY AFTERNOON HOURS ACROSS THE PLAINS BEFORE THE HIGH BUILDS IN. LIGHT WINDS...CLEAR SKIES...AND DRY AIR WILL ALLOW FOR GOOD RADIATIONAL COOLING SATURDAY NIGHT...WITH LOWS IN THE MID 40S TO MID 50S AT MOST LOCATIONS. AS THE HIGH MOVES EAST OF THE REGION LATE SATURDAY NIGHT/EARLY SUNDAY AND RIDGING BUILDS OVER THE ROCKIES...WARMER AIR WILL BEGIN TO ADVECT BACK INTO THE AREA. SOUTH TO SOUTHEAST WINDS WILL DEVELOP ON SUNDAY WITH TEMPS RISING TO THE UPPER 80S TO MID 90S ON THE PLAINS...80S ACROSS THE BLACK HILLS. EXTENDED...RESURGENCE OF THE CENTRAL/WESTERN NOAM RIDGE EXPECTED IN THE PERIOD...WITH THE REGION REMAINING ON THE EDGE OF FAST DISTURBED UPPER LEVEL FLOW. SEMI-PERMANENT NE PAC UPPER TROUGH WILL TEND TO SUPPORT FAST FLOW ALOFT NEARBY WITH PERIODIC SUBTLE SHORTWAVE IMPULSES EXPECTED IN THE FLOW SUPPORTING SOME TS CHANCES IN THE PERIOD...PRIMARILY TUES THROUGH THUR ATTM. OVERALL RAIN CHANCES DO REMAIN BLEAK GIVEN LACK OF DEEP MOISTURE...WITH VERY LIMITED COVERAGE OF ANY STORMS THAT DO MATERIALIZE. WAVE TIMING STILL TO BE RESOLVED TO FURTHER DELINEATE AREAL/TIMING DETAIL. THUS RETAINED POP VALUES VERY CLOSE TO PREVIOUS FORECAST NUMBERS...RETAINING CONSISTENCY. H7 GEFS TEMP ANOMALIES SUGGEST 1-2 STD DEVIATIONS ABOVE CLIMO THROUGH MUCH OF THE PERIOD...ESP TUE ON...THUS A TREND TO THE HIGH SIDE OF GUIDANCE WAS WARRANTED PER HIGHS. REMOVAL OF DEEP MOISTURE WITH OVERALL LIGHT OVERNIGHT FLOW IN MANY PERIODS SUGGEST DECENT RADIATIONAL COOLING...WITH PREFERENCE TOWARD MID GUIDANCE NUMBERS PER LOWS. OVERALL...EXPECT ABOVE NORMAL TEMPS TO CONTINUE IN THE PERIOD...WITH NORMAL TO BELOW NORMAL CHANCES FOR PRECIP. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...CARPENTER LONG TERM....WFO UNR AVIATION...CARPENTER
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
536 PM MDT FRI AUG 3 2012 .UPDATE...KEEPING AN EYE ON THE CONVECTIONS ALONG THE COLD FRONT IN NORTH CENTRAL NEBRASKA THIS AFTERNOON. THE HRRR SHOWS SOME OF THIS DEVELOPING NORTHWARD ACROSS THE SOUTH DAKOTA BORDER LATER THIS EVENING WHEN A STRONG VORTICITY LOBE ROTATES AROUND THE MAIN UPPER LOW THROUGH SOUTH CENTRAL SOUTH DAKOTA. && AVIATION...00Z TAFS AN AREA OF SCT SHRA IS MOVING INTO NORTHEASTERN WYOMING THIS AFTERNOON. CIGS AND VSBYS HAVE NOT BEEN BELOW MVFR IN THE PRECIP...BUT SOMEWHAT LOWER CONDITIONS COULD DEVELOP AS IT MOVES INTO NORTHERN CAMPBELL COUNTY WITH THE UPSLOPE SURFACE FLOW. ELSEWHERE THE STRONGEST AFTERNOON CONVECTION IS CONFINED TO EASTERN PARTS OF SOUTH DAKOTA AND NROTH CENTRAL NEBRASKA. MVFR CONDITIONS POSSIBLE IN HEAVIER STORMS. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THE EVENING. GUSTY NORTHWEST WINDS TO 35 KTS WILL CONTINUE TO GRADUALLY SUBSIDE DURING THE EVENING HOURS. GUSTY NORTHWEST WINDS ARE EXPECTED AGAIN SATURDAY. && .PREV DISCUSSION... /ISSUED 253 PM MDT FRI AUG 3 2012/ DISCUSSION...UPPER LEVEL ANALYSIS HAS LOW PRESSURE OVER FAR SOUTHWESTERN SK MOVING SLOWLY EASTWARD...WITH SOUTHWESTERLY FLOW AHEAD OF IT ACROSS THE NORTHERN PLAINS. CURRENT SURFACE ANALYSIS SHOWS COLD FRONT STRETCHING FROM NORTHEASTERN ND THROUGH CENTRAL SD AND INTO THE NEBRASKA PANHANDLE. TIGHTENING PRESSURE GRADIENT BEHIND THE FRONT IS PRODUCING GUSTY NORTH TO NORTHWEST WINDS ACROSS MUCH OF THE WESTERN SD PLAINS. THE STRONGEST WINDS ARE IN THE RAPID CITY AREA...WHERE A FEW GUSTS TO AROUND 50 MPH HAVE BEEN NOTED. SKIES RANGE FROM MOSTLY CLOUDY ACROSS FAR NORTHEASTERN WY AND NORTHWESTERN SD TO MOSTLY SUNNY ACROSS SOUTHERN SD. MAIN BAND OF SHOWERS AND THUNDERSTORMS IS STAYING NORTH OF THE CWA SO FAR...CLOSER TO THE UPPER LOW. THUNDERSTORMS HAVE ALSO DEVELOPED ALONG THE FRONT FROM CENTRAL ND INTO NORTH CENTRAL SD. TEMPS CURRENTLY RANGE FROM THE UPPER 60S ACROSS PORTIONS OF NORTHEASTERN WY AND NORTHWESTERN SD...TO THE 90S OVER SOUTH CENTRAL SD. COLD FRONT WILL MOVE SLOWLY EAST ACROSS CENTRAL SD LATE THIS AFTERNOON AND INTO EASTERN SD THIS EVENING. UPPER LOW WILL TRACK EAST ACROSS FAR SOUTHERN SK THROUGH TONIGHT. GUSTY WINDS WILL CONTINUE THROUGH THE LATE AFTERNOON AND THEN GRADUALLY DECREASE THIS EVENING. THE BEST CHANCES FOR SHOWERS AND STORMS WILL BE ALONG THE FRONT ACROSS CENTRAL SD LATE THIS AFTERNOON INTO TONIGHT. SUFFICIENT INSTABILITY AND SHEAR REMAINS ALONG AND AHEAD OF THE FRONT ACROSS FAR SOUTH CENTRAL SD TO ALLOW FOR A THREAT OF A SEVERE THUNDERSTORM OR TWO OVER THE NEXT HOUR OR TWO. HOWEVER...THE BETTER THREAT FOR SEVERE STORMS WILL CLEARLY BE ACROSS EASTERN SD THROUGH THIS EVENING. STRONG WIND GUSTS WOULD BE THE MAIN THREAT FROM ANY SEVERE STORMS...BUT LARGE HAIL IS ALSO A POSSIBILITY. A FEW SHOWERS AND STORMS ARE ALSO POSSIBLE OVER NORTHEASTERN WY AND SOUTHWESTERN SD LATE THIS AFTERNOON INTO THIS EVENING AS WEAK SHORTWAVE ENERGY CROSSES ON THE SOUTHERN SIDE OF THE TROF AND INTERACTS WITH WEAK INSTABILITY REMAINING OVER THE AREA. THE POSSIBILITY FOR SHOWER COULD LINGER ACROSS SOUTH CENTRAL SD OVERNIGHT AS THE BACK END OF THE WAVE CROSSES. TEMPS WILL BE PLEASANTLY COOL IN MOST AREAS OVERNIGHT...WITH LOWS MOSTLY IN THE 50S...SOME 40S OVER THE BLACK HILLS AND NORTHEASTERN WY. THE WEEKEND LOOKS TO BE VERY NICE WITH MOSTLY CLEAR SKIES EXPECTED. TEMPS WILL BE PLEASANTLY COOL ON SATURDAY...WITH HIGHS IN THE 70S AND LOWER 80S AS CANADIAN HIGH PRESSURE MOVES INTO THE AREA LATE IN THE DAY. BREEZY NORTHWESTERLY WINDS CAN BE EXPECTED DURING THE LATE MORNING AND EARLY AFTERNOON HOURS ACROSS THE PLAINS BEFORE THE HIGH BUILDS IN. LIGHT WINDS...CLEAR SKIES...AND DRY AIR WILL ALLOW FOR GOOD RADIATIONAL COOLING SATURDAY NIGHT...WITH LOWS IN THE MID 40S TO MID 50S AT MOST LOCATIONS. AS THE HIGH MOVES EAST OF THE REGION LATE SATURDAY NIGHT/EARLY SUNDAY AND RIDGING BUILDS OVER THE ROCKIES...WARMER AIR WILL BEGIN TO ADVECT BACK INTO THE AREA. SOUTH TO SOUTHEAST WINDS WILL DEVELOP ON SUNDAY WITH TEMPS RISING TO THE UPPER 80S TO MID 90S ON THE PLAINS...80S ACROSS THE BLACK HILLS. EXTENDED...RESURGENCE OF THE CENTRAL/WESTERN NOAM RIDGE EXPECTED IN THE PERIOD...WITH THE REGION REMAINING ON THE EDGE OF FAST DISTURBED UPPER LEVEL FLOW. SEMI-PERMANENT NE PAC UPPER TROUGH WILL TEND TO SUPPORT FAST FLOW ALOFT NEARBY WITH PERIODIC SUBTLE SHORTWAVE IMPULSES EXPECTED IN THE FLOW SUPPORTING SOME TS CHANCES IN THE PERIOD...PRIMARILY TUES THROUGH THUR ATTM. OVERALL RAIN CHANCES DO REMAIN BLEAK GIVEN LACK OF DEEP MOISTURE...WITH VERY LIMITED COVERAGE OF ANY STORMS THAT DO MATERIALIZE. WAVE TIMING STILL TO BE RESOLVED TO FURTHER DELINEATE AREAL/TIMING DETAIL. THUS RETAINED POP VALUES VERY CLOSE TO PREVIOUS FORECAST NUMBERS...RETAINING CONSISTENCY. H7 GEFS TEMP ANOMALIES SUGGEST 1-2 STD DEVIATIONS ABOVE CLIMO THROUGH MUCH OF THE PERIOD...ESP TUE ON...THUS A TREND TO THE HIGH SIDE OF GUIDANCE WAS WARRANTED PER HIGHS. REMOVAL OF DEEP MOISTURE WITH OVERALL LIGHT OVERNIGHT FLOW IN MANY PERIODS SUGGEST DECENT RADIATIONAL COOLING...WITH PREFERENCE TOWARD MID GUIDANCE NUMBERS PER LOWS. OVERALL...EXPECT ABOVE NORMAL TEMPS TO CONTINUE IN THE PERIOD...WITH NORMAL TO BELOW NORMAL CHANCES FOR PRECIP. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...CARPENTER LONG TERM....WFO UNR AVIATION...CARPENTER
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
126 PM CDT THU AUG 2 2012 .DISCUSSION... UPDATED FOR 18Z AVIATION DISCUSSION && .PREV DISCUSSION... /ISSUED 1136 AM CDT THU AUG 2 2012/ UPDATE... WENT AHEAD AND BUMPED UP POPS ACROSS THE NORTHEAST HALF OF CWA DUE TO THE THUNDERSTORM ACTIVITY BEGINNING TO POP UP NEAR POPLAR BLUFF MISSOURI INTO CLAY COUNTY ARKANSAS. KRM PREV DISCUSSION... /ISSUED 1030 AM CDT THU AUG 2 2012/ REMNANTS FROM A MCS CONTINUE TO SKIRT EASTERN ARKANSAS THIS MORNING. THE LATEST HRRR RUN SHOWS THE AREA OF RAIN TO CONTINUE TO DISSIPATE AS THE AREA OF PRECIPITATION PUSHES SOUTH. CLOUDS HAVE KEPT TEMPERATURES DOWN FROM NORTHEAST ARKANSAS...TO MEMPHIS TO NORTHWEST MISSISSIPPI. CURRENT TEMPERATURES ARE RUNNING IN THE UPPER 70S TO LOWER 80S. MEANWHILE...ACROSS THE REST OF THE CWA TEMPERATURES ARE IN MID 80S. RELUCTANT TO LOWER HIGHS AT MEMPHIS AND JONESBORO AS LATEST SATELLITE IMAGES SHOW CLOUDS PUSHING TO THE SOUTH AND WEST. THUS EXPECT THE SUN TO PEAK THROUGH BY AFTERNOON. CURRENT FORECAST HAS A GOOD HANDLE...WILL UPDATE AROUND NOON TO REMOVE MORNING WORDING. KRM DISCUSSION... /ISSUED 352 AM CDT THU AUG 2 2012/ FOR TODAY AND TONIGHT...NORTHWESTERLY FLOW AROUND THE UPPER RIDGE WILL CONTINUE FOR THE MIDSOUTH OVER THE NEXT 24 HOURS. TWO DISTINCT DISTURBANCES ARE EXPECTED TO AFFECT THE REGION. THE FIRST HAS BEEN GENERATING CONVECTION OVER CENTRAL ARKANSAS ALL NIGHT WITH AN EVER SO TENDENCY TO SLIDE EASTWARD. THIS WILL AFFECT MAINLY THE COUNTIES ALONG AND WEST OF THE MISSISSIPPI RIVER THIS MORNING. HAVE LIFTED THE CURRENT HEAT ADVISORY FOR THE SOUTHWEST DELTA COUNTIES AS THIS AREA WILL SEE THE LONGEST STRETCH OF CLOUD COVER THROUGHOUT THE DAY KEEPING TEMPERATURE HIGHS IN THE LOW 90S. ELSEWHERE...EXPECT DECREASING CLOUD COVER TOWARDS THE NORTH AND EAST...WITH TEMPERATURES CLIMBING INTO THE MID 90S. THIS WILL ALLOW FOR HEAT INDICES TO REACH 105 DEGREES DESPITE THE THREAT FOR AN AFTERNOON SHOWER OR STORM. THE SECOND DISTURBANCE IS MORE POTENT AND IS GENERATING CONVECTION ACROSS NORTHEAST KANSAS. MODELS ARE IN VERY GOOD AGREEMENT THAT THIS SHORTWAVE WILL SLIDE INTO EASTERN MISSOURI THIS AFTERNOON AND DOWN TO THE TENNESSEE RIVER VALLEY TONIGHT. THE EASTERN HALF OF THE MIDSOUTH WILL HAVE A BETTER CHANCE TO SEE CONVECTION WITH THIS FEATURE...ALONG WITH A THE POSSIBILITY OF A FEW SEVERE STORMS. NOT MUCH CHANGE IS ANTICIPATED FOR FRIDAY AND SATURDAY WITH CONTINUED RAIN CHANCES AND TEMPERATURES IN THE LOW TO MID 90S. HEAT INDICES FOR NOW APPEAR TO BE JUST BELOW THE 105F ADVISORY CRITERIA AS MORE EXTENSIVE CLOUD COVER IS EXPECTED. SUNDAY...TIMING OF MODELS IS STILL ON TRACK WITH A POTENT SHORTWAVE CROSSING THE NORTHERN PLAINS AND WESTERN GREAT LAKES. THIS ENERGY WILL FLATTEN THE RIDGE AND SWING A COLD FRONT SOUTHEAST INTO OUR AREA. THUS RAIN CHANCES REMAIN FAVORABLE SATURDAY NIGHT THROUGH MONDAY MORNING WITH A CONTINUED THREAT FOR A FEW SEVERE STORMS. TEMPERATURES THIS PERIOD WILL REMAIN IN THE LOW TO MID 90S. BEHIND THE FRONT SLIGHTLY DRIER AIR...MAINLY 60 DEGREE DEWPOINTS WILL MOVE INTO THE NORTHERN COUNTIES ON MONDAY AND MAKE THEIR WAY AS FAR SOUTH AS THE TENNESSEE/MISSISSIPPI BORDER BY MONDAY EVENING. TEMPERATURES BEHIND THE FRONT AREN`T EXPECTED TO CHANGE MUCH AS THE SLIGHTLY COOLER AIR WILL ONLY BE OFFSET BY SUNNIER SKIES. EXTENDED PERIOD HAS THE MIDSOUTH BACK INTO THE PESKY NORTHWEST FLOW. HOWEVER THE BRUNT OF DISTURBANCES APPEAR TO STAY NORTH INTO THE SOUTHERN LAKES AND OHIO VALLEY...SO FOR NOW HAVE KEPT THE FORECAST DRY WITH HIGH TEMPERATURES REMAINING CONSISTENT IN THE LOW TO MID 90S. JAB && .AVIATION... EARLIER SHOWERS AND THUNDERSTORMS HAVE WORKED OVER THE AIRMASS ACROSS AT LEAST THE WESTERN HALF OF THE MID SOUTH. RECENT RADAR TRENDS HAVE BEEN UNIMPRESSIVE AND THE CU FIELD IS STRUGGLING TO DEVELOP. LOOKS LIKE THE BEST CHANCE FOR TSRAS THIS AFTN WILL BE AT KTUP. ELSW CHANCES ARE LOW ENOUGH TO REMOVE THE VCTS FOR THE REST OF THE AFTN. THE NEXT UPPER LEVEL DISTURBANCE...LOCATED OVER NRN MO ATTM...WILL TRIGGER ANOTHER ROUND OF TSRAS THIS AFTERNOON THAT WILL MOVE INTO THE MIDSOUTH THIS EVENING AND OVERNIGHT. ADJUSTED VCTS TIMING TO REFLECT THIS THINKING. WINDS WILL GENERALLY BE S/SW AT 8-12 KTS THIS AFTERNOON...DIMINISHING THIS EVENING. SJM && .PRELIMINARY POINT TEMPS/POPS... MEM 96 79 93 77 / 30 40 40 20 MKL 96 73 88 74 / 40 60 50 20 JBR 96 74 95 75 / 40 50 40 30 TUP 95 76 90 74 / 30 20 50 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT- RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL- MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TISHOMINGO- TUNICA-UNION-YALOBUSHA. TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CARROLL-CHESTER- CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN- HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY- OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1136 AM CDT THU AUG 2 2012 .UPDATE... WENT AHEAD AND BUMPED UP POPS ACROSS THE NORTHEAST HALF OF CWA DUE TO THE THUNDERSTORM ACTIVITY BEGINNING TO POP UP NEAR POPLAR BLUFF MISSOURI INTO CLAY COUNTY ARKANSAS. KRM && .PREV DISCUSSION... /ISSUED 1030 AM CDT THU AUG 2 2012/ REMNANTS FROM A MCS CONTINUE TO SKIRT EASTERN ARKANSAS THIS MORNING. THE LATEST HRRR RUN SHOWS THE AREA OF RAIN TO CONTINUE TO DISSIPATE AS THE AREA OF PRECIPITATION PUSHES SOUTH. CLOUDS HAVE KEPT TEMPERATURES DOWN FROM NORTHEAST ARKANSAS...TO MEMPHIS TO NORTHWEST MISSISSIPPI. CURRENT TEMPERATURES ARE RUNNING IN THE UPPER 70S TO LOWER 80S. MEANWHILE...ACROSS THE REST OF THE CWA TEMPERATURES ARE IN MID 80S. RELUCTANT TO LOWER HIGHS AT MEMPHIS AND JONESBORO AS LATEST SATELLITE IMAGES SHOW CLOUDS PUSHING TO THE SOUTH AND WEST. THUS EXPECT THE SUN TO PEAK THROUGH BY AFTERNOON. CURRENT FORECAST HAS A GOOD HANDLE...WILL UPDATE AROUND NOON TO REMOVE MORNING WORDING. KRM && .DISCUSSION... /ISSUED 352 AM CDT THU AUG 2 2012/ FOR TODAY AND TONIGHT...NORTHWESTERLY FLOW AROUND THE UPPER RIDGE WILL CONTINUE FOR THE MIDSOUTH OVER THE NEXT 24 HOURS. TWO DISTINCT DISTURBANCES ARE EXPECTED TO AFFECT THE REGION. THE FIRST HAS BEEN GENERATING CONVECTION OVER CENTRAL ARKANSAS ALL NIGHT WITH AN EVER SO TENDENCY TO SLIDE EASTWARD. THIS WILL AFFECT MAINLY THE COUNTIES ALONG AND WEST OF THE MISSISSIPPI RIVER THIS MORNING. HAVE LIFTED THE CURRENT HEAT ADVISORY FOR THE SOUTHWEST DELTA COUNTIES AS THIS AREA WILL SEE THE LONGEST STRETCH OF CLOUD COVER THROUGHOUT THE DAY KEEPING TEMPERATURE HIGHS IN THE LOW 90S. ELSEWHERE...EXPECT DECREASING CLOUD COVER TOWARDS THE NORTH AND EAST...WITH TEMPERATURES CLIMBING INTO THE MID 90S. THIS WILL ALLOW FOR HEAT INDICES TO REACH 105 DEGREES DESPITE THE THREAT FOR AN AFTERNOON SHOWER OR STORM. THE SECOND DISTURBANCE IS MORE POTENT AND IS GENERATING CONVECTION ACROSS NORTHEAST KANSAS. MODELS ARE IN VERY GOOD AGREEMENT THAT THIS SHORTWAVE WILL SLIDE INTO EASTERN MISSOURI THIS AFTERNOON AND DOWN TO THE TENNESSEE RIVER VALLEY TONIGHT. THE EASTERN HALF OF THE MIDSOUTH WILL HAVE A BETTER CHANCE TO SEE CONVECTION WITH THIS FEATURE...ALONG WITH A THE POSSIBILITY OF A FEW SEVERE STORMS. NOT MUCH CHANGE IS ANTICIPATED FOR FRIDAY AND SATURDAY WITH CONTINUED RAIN CHANCES AND TEMPERATURES IN THE LOW TO MID 90S. HEAT INDICES FOR NOW APPEAR TO BE JUST BELOW THE 105F ADVISORY CRITERIA AS MORE EXTENSIVE CLOUD COVER IS EXPECTED. SUNDAY...TIMING OF MODELS IS STILL ON TRACK WITH A POTENT SHORTWAVE CROSSING THE NORTHERN PLAINS AND WESTERN GREAT LAKES. THIS ENERGY WILL FLATTEN THE RIDGE AND SWING A COLD FRONT SOUTHEAST INTO OUR AREA. THUS RAIN CHANCES REMAIN FAVORABLE SATURDAY NIGHT THROUGH MONDAY MORNING WITH A CONTINUED THREAT FOR A FEW SEVERE STORMS. TEMPERATURES THIS PERIOD WILL REMAIN IN THE LOW TO MID 90S. BEHIND THE FRONT SLIGHTLY DRIER AIR...MAINLY 60 DEGREE DEWPOINTS WILL MOVE INTO THE NORTHERN COUNTIES ON MONDAY AND MAKE THEIR WAY AS FAR SOUTH AS THE TENNESSEE/MISSISSIPPI BORDER BY MONDAY EVENING. TEMPERATURES BEHIND THE FRONT AREN`T EXPECTED TO CHANGE MUCH AS THE SLIGHTLY COOLER AIR WILL ONLY BE OFFSET BY SUNNIER SKIES. EXTENDED PERIOD HAS THE MIDSOUTH BACK INTO THE PESKY NORTHWEST FLOW. HOWEVER THE BRUNT OF DISTURBANCES APPEAR TO STAY NORTH INTO THE SOUTHERN LAKES AND OHIO VALLEY...SO FOR NOW HAVE KEPT THE FORECAST DRY WITH HIGH TEMPERATURES REMAINING CONSISTENT IN THE LOW TO MID 90S. JAB && .AVIATION... 12Z TAF CYCLE (02/12Z-03/12Z) SHOWERS AND THUNDERSTORMS IN A BAND ACROSS PORTIONS OF EASTERN AR HAVE BEEN MOVING MAINLY NORTH TO SOUTH EARLIER THIS MORNING...REMAINING WEST OF KJBR. DID MENTION VCSH AT KJBR UNTIL 15Z AND WILL MONITOR FOR AMENDING TO ADD VCTS IF THE ACTIVITY DOES CREEP FURTHER EASTWARD. OTHERWISE VFR CONDITIONS ARE EXPECTED TO PREVAIL MOST OF THE PERIOD AT THE TAF SITES. CONTINUED MENTION OF VCTS AT ALL THE TAF SITES THIS AFTERNOON AND EARLY EVENING WITH DAYTIME HEATING. MODELS INDICATE A MESOSCALE CONVECTION SYSTEM MAY MOVE INTO THE REGION FROM THE NORTH LATE TONIGHT...FOR NOW INCLUDED VCTS AT KJBR AND KMKL AFTER 03/06Z AND AT KMEM AFTER 03/09Z. WINDS MAINLY S TO SW BECOMING 8-12 KTS TODAY...WINDS TONIGHT SOUTHERLY 4-8 KTS. JCL && && .PRELIMINARY POINT TEMPS/POPS... MEM 96 76 94 77 / 30 20 40 20 MKL 96 73 90 74 / 40 40 50 20 JBR 96 75 93 75 / 40 20 40 10 TUP 95 74 91 73 / 30 40 50 20 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT- RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL- MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TISHOMINGO- TUNICA-UNION-YALOBUSHA. TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CARROLL-CHESTER- CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN- HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY- OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1030 AM CDT THU AUG 2 2012 .UPDATE... REMNANTS FROM A MCS CONTINUE TO SKIRT EASTERN ARKANSAS THIS MORNING. THE LATEST HRRR RUN SHOWS THE AREA OF RAIN TO CONTINUE TO DISSIPATE AS THE AREA OF PRECIPITATION PUSHES SOUTH. CLOUDS HAVE KEPT TEMPERATURES DOWN FROM NORTHEAST ARKANSAS...TO MEMPHIS TO NORTHWEST MISSISSIPPI. CURRENT TEMPERATURES ARE RUNNING IN THE UPPER 70S TO LOWER 80S. MEANWHILE...ACROSS THE REST OF THE CWA TEMPERATURES ARE IN MID 80S. RELUCTANT TO LOWER HIGHS AT MEMPHIS AND JONESBORO AS LATEST SATELLITE IMAGES SHOW CLOUDS PUSHING TO THE SOUTH AND WEST. THUS EXPECT THE SUN TO PEAK THROUGH BY AFTERNOON. CURRENT FORECAST HAS A GOOD HANDLE...WILL UPDATE AROUND NOON TO REMOVE MORNING WORDING. KRM && .DISCUSSION... /ISSUED 352 AM CDT THU AUG 2 2012/ FOR TODAY AND TONIGHT...NORTHWESTERLY FLOW AROUND THE UPPER RIDGE WILL CONTINUE FOR THE MIDSOUTH OVER THE NEXT 24 HOURS. TWO DISTINCT DISTURBANCES ARE EXPECTED TO AFFECT THE REGION. THE FIRST HAS BEEN GENERATING CONVECTION OVER CENTRAL ARKANSAS ALL NIGHT WITH AN EVER SO TENDENCY TO SLIDE EASTWARD. THIS WILL AFFECT MAINLY THE COUNTIES ALONG AND WEST OF THE MISSISSIPPI RIVER THIS MORNING. HAVE LIFTED THE CURRENT HEAT ADVISORY FOR THE SOUTHWEST DELTA COUNTIES AS THIS AREA WILL SEE THE LONGEST STRETCH OF CLOUD COVER THROUGHOUT THE DAY KEEPING TEMPERATURE HIGHS IN THE LOW 90S. ELSEWHERE...EXPECT DECREASING CLOUD COVER TOWARDS THE NORTH AND EAST...WITH TEMPERATURES CLIMBING INTO THE MID 90S. THIS WILL ALLOW FOR HEAT INDICES TO REACH 105 DEGREES DESPITE THE THREAT FOR AN AFTERNOON SHOWER OR STORM. THE SECOND DISTURBANCE IS MORE POTENT AND IS GENERATING CONVECTION ACROSS NORTHEAST KANSAS. MODELS ARE IN VERY GOOD AGREEMENT THAT THIS SHORTWAVE WILL SLIDE INTO EASTERN MISSOURI THIS AFTERNOON AND DOWN TO THE TENNESSEE RIVER VALLEY TONIGHT. THE EASTERN HALF OF THE MIDSOUTH WILL HAVE A BETTER CHANCE TO SEE CONVECTION WITH THIS FEATURE...ALONG WITH A THE POSSIBILITY OF A FEW SEVERE STORMS. NOT MUCH CHANGE IS ANTICIPATED FOR FRIDAY AND SATURDAY WITH CONTINUED RAIN CHANCES AND TEMPERATURES IN THE LOW TO MID 90S. HEAT INDICES FOR NOW APPEAR TO BE JUST BELOW THE 105F ADVISORY CRITERIA AS MORE EXTENSIVE CLOUD COVER IS EXPECTED. SUNDAY...TIMING OF MODELS IS STILL ON TRACK WITH A POTENT SHORTWAVE CROSSING THE NORTHERN PLAINS AND WESTERN GREAT LAKES. THIS ENERGY WILL FLATTEN THE RIDGE AND SWING A COLD FRONT SOUTHEAST INTO OUR AREA. THUS RAIN CHANCES REMAIN FAVORABLE SATURDAY NIGHT THROUGH MONDAY MORNING WITH A CONTINUED THREAT FOR A FEW SEVERE STORMS. TEMPERATURES THIS PERIOD WILL REMAIN IN THE LOW TO MID 90S. BEHIND THE FRONT SLIGHTLY DRIER AIR...MAINLY 60 DEGREE DEWPOINTS WILL MOVE INTO THE NORTHERN COUNTIES ON MONDAY AND MAKE THEIR WAY AS FAR SOUTH AS THE TENNESSEE/MISSISSIPPI BORDER BY MONDAY EVENING. TEMPERATURES BEHIND THE FRONT AREN`T EXPECTED TO CHANGE MUCH AS THE SLIGHTLY COOLER AIR WILL ONLY BE OFFSET BY SUNNIER SKIES. EXTENDED PERIOD HAS THE MIDSOUTH BACK INTO THE PESKY NORTHWEST FLOW. HOWEVER THE BRUNT OF DISTURBANCES APPEAR TO STAY NORTH INTO THE SOUTHERN LAKES AND OHIO VALLEY...SO FOR NOW HAVE KEPT THE FORECAST DRY WITH HIGH TEMPERATURES REMAINING CONSISTENT IN THE LOW TO MID 90S. JAB && .AVIATION... 12Z TAF CYCLE (02/12Z-03/12Z) SHOWERS AND THUNDERSTORMS IN A BAND ACROSS PORTIONS OF EASTERN AR HAVE BEEN MOVING MAINLY NORTH TO SOUTH EARLIER THIS MORNING...REMAINING WEST OF KJBR. DID MENTION VCSH AT KJBR UNTIL 15Z AND WILL MONITOR FOR AMENDING TO ADD VCTS IF THE ACTIVITY DOES CREEP FURTHER EASTWARD. OTHERWISE VFR CONDITIONS ARE EXPECTED TO PREVAIL MOST OF THE PERIOD AT THE TAF SITES. CONTINUED MENTION OF VCTS AT ALL THE TAF SITES THIS AFTERNOON AND EARLY EVENING WITH DAYTIME HEATING. MODELS INDICATE A MESOSCALE CONVECTION SYSTEM MAY MOVE INTO THE REGION FROM THE NORTH LATE TONIGHT...FOR NOW INCLUDED VCTS AT KJBR AND KMKL AFTER 03/06Z AND AT KMEM AFTER 03/09Z. WINDS MAINLY S TO SW BECOMING 8-12 KTS TODAY...WINDS TONIGHT SOUTHERLY 4-8 KTS. JCL && && .PRELIMINARY POINT TEMPS/POPS... MEM 96 76 94 77 / 30 20 40 20 MKL 96 73 90 74 / 30 40 50 20 JBR 96 75 93 75 / 40 20 40 10 TUP 95 74 91 73 / 30 40 50 20 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT- RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL- MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TISHOMINGO- TUNICA-UNION-YALOBUSHA. TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CARROLL-CHESTER- CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN- HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY- OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
747 PM EDT FRI AUG 3 2012 .SYNOPSIS... SEVERAL UPPER LEVEL DISTURBANCES WILL MOVE EAST ACROSS OUR REGION TONIGHT INTO SATURDAY. ALOFT...A LARGE RIDGE OF HIGH PRESSURE COVERED TEXAS...THIS RIDGE FORECAST TO EXPAND OVER THE SOUTHEAST AND THE MIDDLE ATLANTIC THROUGH THE WEEKEND. A COLD FRONT WILL DROP SOUTH FROM THE GREAT LAKES AND THE OHIO VALLEY EARLY NEXT WEEK...THE RESULT OF AN AGGRESSIVE UPPER LEVEL TROUGH WHICH IS FORECAST TO MOVE THROUGH THE GREAT LAKES AND OHIO VALLEY REGION SUNDAY INTO MONDAY. && .NEAR TERM /THROUGH SATURDAY/... AS OF 725 PM EDT FRIDAY... LARGE AREA OF SHOWERS WITH EMBEDDED THUNDERSTORMS ACROSS FAR SW VA INTO NE TN IN ASSOCIATION WITH UPPER SHORTWAVE SHOULD MOVED EWD THROUGH THE EVENING AFFECTING MOST LOCATIONS WEST OF I-77 IN VA/WV. THUNDERSTORMS HAVE BEEN WEAKENING WITH AIRMASS STABILIZING UNDER COOLING RAINS. THE REST OF THE AREA SHOULD STAY IN A ISOLATED TO SCATTERED COVERAGE INTO THE EVENING WITH HEAVY RAIN POSSIBLE AT TIMES. OTHERWISE...NOT MANY OTHER CHANGES TO THE FORECAST. PREVIOUS DISCUSSION AT 400 PM... COMPLICATED FORECAST WITH PLACEMENT OF CONVECTION THIS EVENING INTO TONIGHT. THE LOW CLOUDS WHICH LIFTED NORTH ACROSS THE REGION THIS MORNING ESPECIALLY ALONG THE EASTERN SLOPES OF BLUE RIDGE HAS SLOWED THE DEVELOPMENT OF THE THUNDERSTORMS THIS AFTERNOON AND HINDERED INSTABILITY. KFCX 88D SHOWED ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING AHEAD OF AREAS OF CONVECTION ACROSS EASTERN KENTUCKY. THIS CONVECTION IS ASSOCIATED WITH SHORTWAVE MOVING SLOWLY ESE. OUTFLOW AND LEFTOVER BOUNDARIES FROM THUNDERSTORMS WILL MOVE ACROSS OUR REGION THIS EVENING INTO TONIGHT. CONVECTION WHICH FIRES ALONG THE UPPER LEVEL DISTURBANCE ALONG THE CAROLINA COAST... MAY SEND AXIS OF DEEPER MOISTURE NORTHWARD INTO OUR SE CWA INITIATING LATE AFTERNOON AND EVE SHRA/TSRA. NAM...GFS...WRFARW-RNK AND HRRR PLACE THE HIGHEST POPS ACROSS SOUTHWEST PORTION OF CWA THIS AFTERNOON INTO TONIGHT. OVERALL...DEEP LAYER WINDS ACROSS THE MID ATLANTIC REGION REMAIN WEAK...MEAN WIND LESS THAN 10 KTS. ANY DEEP CONVECTION THAT DEVELOPS WILL BE SLOW MOVING WITH POTENTIAL OF HEAVY RAINS. TAPER OFF POPS WITH THE LOSS OF SOLAR HEATING TONIGHT BUT HOLD ON TO SOME ACTIVITY IN THE SOUTHWEST. LEANED LOW TEMPERATURES TONIGHT TOWARDS THE ADJMET WITH THE IDEA OF MORE CLOUDINESS KEEPING TEMPERATURES ELEVATED. ALSO ADD THE MENTION OF PATCHY FOG OVERNIGHT WHICH CAN BE SHAPED TO WHERE THUNDERSTORMS OCCUR. DEEPER MOISTURE WILL REMAIN IN PLACE ESPECIALLY OVER THE WEST SATURDAY. WEAKENING MID LEVEL WAVE AND OLD BOUNDARIES REMAINS ALONG THE MOUNTAINS SATURDAY AFTERNOON DURING MAX HEATING. THE COMBINATION OF W/NW FLOW ALOFT AND DECENT INSTABILITY WEST APPEARS TO BE A GOOD SETUP FOR MULTICELLULAR BANDS ACROSS THE MOUNTAINS...WITH SOME OF THIS ACTIVITY ABLE TO SPILL EAST OF THE BLUE RIDGE LATE. INCREASED POPS AND EXTENDED CHANCES OUT EAST TO THE PIEDMONT. SHAPED TIMING AND POPS CLOSE TO NAM. PLAYED HIGH CLOSER TO COOL MOS BECAUSE OF CLOUD COVER WITH READINGS FROM THE MID 70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE SOUTHEAST. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 330 PM EDT FRIDAY... SCATTERED LINGERING SHOWERS AND STORMS LATE SATURDAY ARE LIKELY TO QUICKLY DISSIPATE BY LATE EVENING AS LITTLE IN THE WAY OF ORGANIZED FORCING IS EXPECTED IN GENERALLY SOUTHERLY FLOW. THE 12Z GFS PRODUCES SOME CONVECTIVELY INDUCED SHORT WAVES OVER TN/KY AND TRIES TO CONTINUE SOME ACTIVITY MOST OF THE NIGHT ACROSS THE WEST BUT FEEL THIS IS PROBABLY OVERDONE TO LARGE DEGREE...WHEREAS NAM HAS NOTHING ACROSS THE WEST BUT CONTINUES CONVECTION ACROSS THE FAR EAST WELL PAST MIDNIGHT IN ASSOC WITH A VERY WEAK LEE TROUGH. NOT SURE HOW MUCH TO TRUST EITHER SOLUTION...BUT WILL LEAN MORE TOWARD THE GFS NOTION OF KEEPING CHANCES GOING A LITTLE LONGER IN THE WEST...BUT WILL DROP POPS QUICKLY AFTER MIDNIGHT. SUNDAY APPEARS TO HAVE BETTER CHANCES...ESPECIALLY LATER IN THE DAY OUT AHEAD OF APPROACHING FRONTAL BOUNDARY COMING OUT OF OHIO VALLEY. SOME INCREASE IN SHEAR AND SLIGHTLY STEEPER LAPSE RATES SUGGEST A BETTER SEVERE POTENTIAL AS WELL...WITH MORE ORGANIZED CLUSTERS COMING OUT OF OF WV AHEAD OF FRONT. MAIN THREAT DURING THE DAY WOULD MAINLY BE IN THE WEST. EXACT TIMING IS IN QUESTION...INCLUDING WHETHER THERE WILL BE STORMS WELL OUT AHEAD OF FRONT DEVELOPING WITH MAX HEATING AND OVER HIGHER TERRAIN...OR DOES IT WAIT UNTIL FRONTAL BOUNDARY ACTUALLY ARRIVES WHICH WOULD BE MORE EVENING AND EVEN OVERNIGHT IN THE WEST. SEVERE CHANCES MUCH LESS EAST OF THE BLUE RIDGE GIVEN TIMING OF FRONT...BUT IF ANYTHING DEVELOPS WELL OUT AHEAD...A FEW OF THESE STORMS COULD DRIFT INTO THE PIEDMONT LATE IN THE DAY. IN ANY CASE...EXPECT AT LEAST MORE CLOUD COVER FROM UPSTREAM CONVECTION TO KEEP TEMPS DOWN A BIT IN THE WEST...SO WENT CLOSER TO COOLER MET GUIDANCE IN WEST...AND WARMER MAV IN EAST. BOUNDARY SLOWLY DRIFTS ACROSS THE FCST AREA SUNDAY NIGHT INTO MONDAY...AND MUCH BETTER CHANCE FOR LINGERING CONVECTION OR AT LEAST SHOWERS MOST OF THE NIGHT SUNDAY NIGHT...AND ANY REDEVELOPMENT OF DEEPER CONVECTION MONDAY WOULD BE ACROSS THE SOUTHEAST...AND DEPENDENT ON ANY SMALL DEGREE OF SFC HEATING...BUT SEVERE CHANCES SHOULD BE MUCH LOWER DUE TO LACK OF GOOD HEATING MONDAY. MONDAY MORNING LOWS SHOULD BE PRETTY MILD WITH MOSTLY CLOUDY AND EVEN ONGOING SHOWERS...AND MAV NUMBERS LOOK GOOD THERE WITH LOW TO MID 70S FOR MINS IN PIEDMONT AND UPPER 60S TO NEAR 70 WEST. SLIGHTLY COOLER TEMPS FOR MONDAY...ESPECIALLY BEHIND BOUNDARY IN WEST...BUT IN THE EAST WEVMAY NEED TO DROP TEMPS A LITTLE MORE IN THE EAST IF IT LOOKS LIKE CLOUDS AND SHOWERS WILL NOT GIVE WAY TO ANY SUNSHINE AT ALL DURING THE DAY MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 1230 PM EDT FRIDAY... THE WEATHER PATTERN THROUGH MUCH OF NEXT WEEK WILL BE INFLUENCED BY BOTH A STRONG RIDGE OF WARM HIGH PRESSURE OVER MUCH OF THE COUTH CENTRAL PORTIONS OF THE COUNTRY...AS WELL AS A DEVELOPING WEAK TROUGH ACROSS THE NORTHEAST WITH ASSOCIATED SLOW MOVING WEAK FRONTAL BOUNDARYS MOVING IN FROM THE NORTHWEST. THESE FEATURES WILL KEEP TEMPERATURES NEAR SEASONABLE READINGS THROUGH THE WEEK...WITH A CONTINUING CHANCE FOR SHOWERS AND THUNDERSTORMS ON MOST DAYS. MORE SPECIFICALLY...THE FRONTAL BOUNDARY SLOWLY MOVING ACROSS THE APPALACHIAN REGION ON MONDAY WILL LIKELY BE LINGERING ACROSS THE PIEDMONT INTO MONDAY NIGHT AND TUESDAY...BEFORE WASHING OUT ACROSS THE CAROLINAS. THERE ARE SIGNS IN SOME OF THE GUIDANCE OF A WEAK WAVE MOVING UP FROM THE SOUTHWEST...SO WHILE EXPECTING BETTER COVERAGE OF SHOWERS AND STORMS CLOSER TO THE FRONT IN THE EASTERN HALF OF THE FCST AREA TUESDAY...CAN ELIMINATE CHANCES FARTHER WEST GIVEN THIS POSSIBLE WAVE. WITH FAIRLY GOOD CLOUD COVER LIKELY...THIS COULD BE COOLEST DAY OF THE WEEK FOR SOME AREAS. WEDNESDAY WILL HAVE LESS OF A FOCUSING MECHANISM...BUT WITH WEAK TROUGH DEVELOPING OVERHEAD...AND MORE SUNSHINE PROBABLE...COULD RESULT IN STEEPER LAPSE RATES OVERALL...SO WORTH KEEPING CHC FOR SCATTERED AFTERNOON CONVECTION. PROBABLY BETTER CHANCES ACROSS THE SOUTHEAST...IF LINGERING CONVERGENCE WITH OLD BOUNDARY IS STILL PRESENT. BY THURS AND FRIDAY WILL HAVE TO RELY MORE ON DAYTIME HEATING AND LINGERING LOW LEVEL MSTR...BUT WITH WEAK TROUGH ALOFT AND NO PUSH OF DRIER AIR EVIDENT...FEEL ITS WORTH KEEPING LOW CHC POPS. ON FRIDAY THE INFLUENCE OF ANOTHER WEAK FRONT TO THE NORTH MAY BE ENOUGH TO PROVIDE SLIGHTLY BETTER CHANCES...BUT BY THIS TIME THERE IS ENOUGH DIFFERENCE IN MODEL GUIDANCE...WITH SOME HOLDING THIS FRONT OFF UNTIL SAT OR LATER...NOT TO PUT MUCH EMPHASIS ON MUCH OF A CHANGE BETWEEN THURS AND FRIDAY. WITH GENERALLY MORE SUN BY MID TO LATE WEEK ONCE THE FRONT FROM EARLY IN THE WEEK GOES BY AND WEAKENS...EXPECTING A VERY GRADUAL WARMING TREND BY LATE IN THE WEEK...WITH PIEDMONT HIGH TEMPS REACHING BACK INTO THE LOW TO MID 90S BY LATE IN THE WEEK. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... AS OF 730 PM EDT FRIDAY... WATCHING CONVECTION NEAR LYH/DAN AND BLF THIS EVENING BUT THINKING WEAKENING TREND CONTINUES SO NOT ALLOWING ANY THUNDER EXCEPT VCTS AT BLF. WILL HAVE TO SEE HOW THINGS EVOLVE OVERNIGHT WITH SHOWERS IN THE FAR SOUTHWEST VA AREA NUDGING EWD. THINK BLF WILL SEE SHOWERS INTO THE EVENING WITH CIGS/VSBYS STAYING MAINLY VFR BUT COULD SEE VSBYS SINK INTO MVFR WITH HEAVY RAIN. THE REST OF THE AREA WILL BE MUGGY WITH SOME FOG FORMING ESPECIALLY WHERE IT RAINED. AN ISSUE COULD BE CLOUD COVER WHICH COULD IMPEDE HOW LOW VSBYS GO. CONFIDENT ENOUGH ON BCB/LWB DROPPING TO LIFR OVERNIGHT WITH DAN/LYH/ROA STAYING IFR/MVFR WHILE BLF CLEARS OUT ENOUGH LATE TO DROP AROUND 1SM. THE FOG WILL DISSIPATE SLOWLY SAT MORNING AND MODELS SHOWING THE NEXT WAVE OF STORMS MOVING INTO THE MTNS AROUND 15-18Z THEN EAST IN THE AFTN. WILL KEEP VCTS AT ALL SITES EXCEPT DAN WITH VFR CIGS/VSBYS. DEEPER MOISTURE REMAINS INTO EARLY NEXT WEEK WITH GREATER COVERAGE OF SHOWERS AND STORMS...ESPCLY DURING THE AFTERNOON AND EVENING EACH DAY THROUGH MONDAY. LOCAL MVFR/IFR CONDITIONS WILL BE ASSOCIATED WITH THE MORE ORGANIZED STORMS. OUTSIDE OF THIS MAINLY DIURNALLY DRIVEN CONVECTION...THE ONLY OTHER FLIGHT WEATHER HAZARDS WOULD BE FROM OVERNIGHT VALLEY FOG. A COLD FRONT IS EXPECTED TO DROP SOUTHEAST OUT OF THE OHIO VALLEY MONDAY...CROSSING THE MID ATLANTIC REGION. WITH THE PASSAGE OF THIS FRONT...WINDS SHOULD BECOME NORTHERLY...WITH A DAY OR TWO OF DRY WEATHER AND VFR CONDITIONS FOLLOWING THE FRONTAL PASSAGE FOR MID WEEK. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...PM NEAR TERM...KK/WP SHORT TERM...SK LONG TERM...SK AVIATION...KK/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1051 PM CDT FRI AUG 3 2012 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .UPDATE... ISOLATED SHOWERS AND STORMS PERSIST OVER CENTRAL WISCONSIN EARLY THIS EVENING ALONG A SUBTLE BOUNDARY. PREVIOUSLY HANDLED THIS CONVECTION WITH NOWCASTS. BUT WILL NOW UPDATE TO ADD TO THE ZONE FORECASTS DUE TO WATER VAPOR LOOP SHOWS SOME MID LEVEL DRYING WORKING INTO CENTRAL WISCONSIN THIS EVENING. ITS POSSIBLE THIS MAY INTENSIFY THE ONGOING CONVECTION OR INCREASE THE CONVECTION ALONG THE BOUNDARY. TDH && .PREV DISCUSSION...ISSUED AT 651 PM CDT FRI AUG 3 2012... SHORT TERM...TODAY THROUGH SATURDAY. IN THE NEAR-TERM...SC SLOWLY DISSIPATED DURING THE DAY THANKS TO EASTERLY LOW-LEVEL FLOW. AS CONVECTIVE TEMP IS MET...CU FIELD DEVELOPS...AS SEEN ON LATEST VIS SATELLITE IMAGERY. BOTH 03/15Z RUNS OF HRRR AND RAP INDICATE ISOLATED CONVECTION IN NE WI BETWEEN 3 AND 6 PM...NOT UNLIKE YESTERDAY`S EARLY EVENING ISOLATED EVENT. BUT PROBABILITY TOO LOW TO INCLUDE IN GRIDS AT THIS TIME. SHARP UPPER TROUGH WILL PRODUCE GOOD UPPER DIFFLUENCE ACROSS MINNESOTA TONIGHT. THAT COUPLED WITH A MODEST LOW LEVEL JET SHOULD RESULT IN CONVECTION THAT COULD DRIFT INTO OUR WESTERN COUNTIES TOWARD MORNING. BOTH THE 03/12Z NAM AND GFS HINT AT THIS. MINIMUM TEMPERATURES SHOULD BE HELD UP ABOVE NORMAL ONCE AGAIN BY INCREASING CLOUD COVER. THE UPPER TROUGH MOVES INTO WESTERN WISCONSIN LATE SATURDAY. WHILE DEBRIS FROM ANY LEFTOVER CONVECTION WILL HAVE TO BE DEALT WITH...AIRMASS SHOULD DESTABILIZE SUFFICIENTLY WITH PRESENCE OF UPPER TROF TO INCREASE THUNDERSTORM THREAT AFTER 18Z. INCREASING DEEP SHEAR AND INSTABILITY INDICATE THREAT FOR SEVERE STORMS...THOUGH BEST CHANCE WOULD BE ACROSS SE THIRD OF WI...PER SPC DAY 2 OUTLOOK. AS IS USUALLY THE CASE...SEVERE THREAT WILL LARGELY HINGE ON THE TIMING OF THE SYSTEM AND THE DEGREE OF INSTABILITY SATURDAY AFTERNOON. TEMPS ON SATURDAY SHOULD REACH NEAR 90 ACROSS THE FOX VALLEY WITH ANY AMOUNT OF SUNSHINE. TEMPS IN THE LOWER 80S ACROSS THE FAR N WITH MORE CLOUDS AND PRECIP TO START THE DAY. ALL-IN-ALL...PREVIOUS FORECAST WAS IN GOOD SHAPE SO ONLY MINOR TWEAKING WAS NEEDED. LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY. MAIN FORECAST CONCERN WILL BE THE EXITING SYSTEM SUNDAY NIGHT AND CLOUDS/LINGERING PRECIP OVER THE NORTH SUNDAY MIDDAY. ...SATURDAY NIGHT AND SUNDAY... COLD FRONT SHOULD BE IN THE VICINITY OF THE FOX VALLEY AROUND 00Z SUNDAY. MODEL CONSENSUS HAS TRENDED TOWARDS THIS SLOWER SOLUTION...SO KEPT PRECIP IN THE CWA LONGER THAN THE PREVIOUS FORECAST. THE COLD FRONT SHOULD MOVE OUT WITH THE UPPER LEVEL SYSTEM AND CLEAR THE AREA BETWEEN 09-12Z SUNDAY. GFS/ECMWF HAVE BEEN THE SLOWEST AND KEEP PRECIP AROUND THE LONGEST...THEREFORE HAVE SHOWERS CONTINUING ON THE LAKESHORE UNTIL SUNDAY MORNING. AFTER THAT...MUCH OF THE AREA IS EXPECTED TO REMAIN DRY FOR SUNDAY. THE ONLY EXCEPTION BEING MODELS TRENDING TOWARDS AN AREA OF CLOUDS AND SHOWERS OVER NORTHERN WISCONSIN AROUND MIDDAY SUNDAY AS A WEAK JET STREAK SWINGS THROUGH ON THE BACK SIDE OF THE 500MB TROUGH. WITH MODERATELY UNSTABLE MIDLEVEL LAPSE RATES AROUND 7C AND THE GFS/GEM PUTTING PRECIP OVER THE NORTH SUNDAY MORNING THROUGH THE EARLY AFTERNOON...ADDED SLIGHT CHANCES OF SHOWERS OVER THIS AREA UNTIL MIDDAY PER MODEL TRENDS. SKIES WILL CLEAR OUT BY SUNDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE AREA. GUIDANCE HAS TRENDED COOLER SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH TEMPERATURES...SO BROUGHT MAX/MIN TEMPS DOWN A FEW DEGREES. WITH CLEARING SKIES AND CAA IN PLACE...MIN TEMPS COULD GET RELATIVELY COLD SUNDAY NIGHT. ...MONDAY THROUGH FRIDAY... HIGH PRESSURE HOLDS OVER WISCONSIN THROUGH MUCH OF THE PERIOD WITH WEAK IMPULSES MOVING THROUGH THE MEAN ZONAL FLOW. A COUPLE OF CHANCES FOR PRECIP IN THE EXTENDED...BEGINNING WITH MONDAY NIGHT INTO TUESDAY AS A WEAK COLD FRONT PUSHES SOUTHEAST THROUGH THE STATE. BETTER CHANCE LOOKS TO BE THURSDAY INTO FRIDAY AS A STRONGER SHORTWAVE SWINGS THROUGH NORTHERN WISCONSIN. TEMPERATURES SHOULD RETURN TO NEAR NORMAL OR SLIGHTLY ABOVE NORMAL LEVELS THROUGH NEXT WEEK. && .AVIATION...LINE OF STORMS JUST WEST OF THE WISCONSIN/MINNESOTA BORDER LATE EVENING WILL BE MARCHING ACROSS WESTERN WISCONSIN BY MIDNIGHT BEFORE WORKING TOWARD CENTRAL AND NORTH CENTRAL WISCONSIN EARLY THIS MORNING. SEVERE WEATHER WAS OBSERVED WITH THIS LINE OVER WESTERN MINNESOTA BUT HAS DIMINISHED. ALONG WITH THE CONVECTION DEBRIS CLOUDS WITH AREAS OF MVFR CIGS AND VSBYS CAN BE EXPECTED. MAIN DYNAMICS WITH DEEP SHORT WAVE TROUGH AND COLD FRONT WILL PASS OVER THE STATE ON SATURDAY FOR A FEW ROUNDS OF SHOWERS AND STORMS. IFR CONDITIONS CAN BE EXPECTED WITH THE STRONGER STORMS. A FEW STORMS MAY BE SEVERE OVER CENTRAL AND NORTH CENTRAL WISCONSIN EARLY TO MID AFTERNOON AND THEN LATER AFTERNOON AND EVENING OVER EASTERN WISCONSIN. TDH && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
728 PM CDT FRI AUG 3 2012 .UPDATE... ISOLATED SHOWERS AND STORMS PERSIST OVER CENTRAL WISCONSIN EARLY THIS EVENING ALONG A SUBTLE BOUNDARY. PREVIOUSLY HANDLED THIS CONVECTION WITH NOWCASTS. BUT WILL NOW UPDATE TO ADD TO THE ZONE FORECASTS DUE TO WATER VAPOR LOOP SHOWS SOME MID LEVEL DRYING WORKING INTO CENTRAL WISCONSIN THIS EVENING. ITS POSSIBLE THIS MAY INTENSIFY THE ONGOING CONVECTION OR INCREASE THE CONVECTION ALONG THE BOUNDARY. TDH && .PREV DISCUSSION...ISSUED AT 651 PM CDT FRI AUG 3 2012... SHORT TERM...TODAY THROUGH SATURDAY. IN THE NEAR-TERM...SC SLOWLY DISSIPATED DURING THE DAY THANKS TO EASTERLY LOW-LEVEL FLOW. AS CONVECTIVE TEMP IS MET...CU FIELD DEVELOPS...AS SEEN ON LATEST VIS SATELLITE IMAGERY. BOTH 03/15Z RUNS OF HRRR AND RAP INDICATE ISOLATED CONVECTION IN NE WI BETWEEN 3 AND 6 PM...NOT UNLIKE YESTERDAY`S EARLY EVENING ISOLATED EVENT. BUT PROBABILITY TOO LOW TO INCLUDE IN GRIDS AT THIS TIME. SHARP UPPER TROUGH WILL PRODUCE GOOD UPPER DIFFLUENCE ACROSS MINNESOTA TONIGHT. THAT COUPLED WITH A MODEST LOW LEVEL JET SHOULD RESULT IN CONVECTION THAT COULD DRIFT INTO OUR WESTERN COUNTIES TOWARD MORNING. BOTH THE 03/12Z NAM AND GFS HINT AT THIS. MINIMUM TEMPERATURES SHOULD BE HELD UP ABOVE NORMAL ONCE AGAIN BY INCREASING CLOUD COVER. THE UPPER TROUGH MOVES INTO WESTERN WISCONSIN LATE SATURDAY. WHILE DEBRIS FROM ANY LEFTOVER CONVECTION WILL HAVE TO BE DEALT WITH...AIRMASS SHOULD DESTABILIZE SUFFICIENTLY WITH PRESENCE OF UPPER TROF TO INCREASE THUNDERSTORM THREAT AFTER 18Z. INCREASING DEEP SHEAR AND INSTABILITY INDICATE THREAT FOR SEVERE STORMS...THOUGH BEST CHANCE WOULD BE ACROSS SE THIRD OF WI...PER SPC DAY 2 OUTLOOK. AS IS USUALLY THE CASE...SEVERE THREAT WILL LARGELY HINGE ON THE TIMING OF THE SYSTEM AND THE DEGREE OF INSTABILITY SATURDAY AFTERNOON. TEMPS ON SATURDAY SHOULD REACH NEAR 90 ACROSS THE FOX VALLEY WITH ANY AMOUNT OF SUNSHINE. TEMPS IN THE LOWER 80S ACROSS THE FAR N WITH MORE CLOUDS AND PRECIP TO START THE DAY. ALL-IN-ALL...PREVIOUS FORECAST WAS IN GOOD SHAPE SO ONLY MINOR TWEAKING WAS NEEDED. LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY. MAIN FORECAST CONCERN WILL BE THE EXITING SYSTEM SUNDAY NIGHT AND CLOUDS/LINGERING PRECIP OVER THE NORTH SUNDAY MIDDAY. ...SATURDAY NIGHT AND SUNDAY... COLD FRONT SHOULD BE IN THE VICINITY OF THE FOX VALLEY AROUND 00Z SUNDAY. MODEL CONSENSUS HAS TRENDED TOWARDS THIS SLOWER SOLUTION...SO KEPT PRECIP IN THE CWA LONGER THAN THE PREVIOUS FORECAST. THE COLD FRONT SHOULD MOVE OUT WITH THE UPPER LEVEL SYSTEM AND CLEAR THE AREA BETWEEN 09-12Z SUNDAY. GFS/ECMWF HAVE BEEN THE SLOWEST AND KEEP PRECIP AROUND THE LONGEST...THEREFORE HAVE SHOWERS CONTINUING ON THE LAKESHORE UNTIL SUNDAY MORNING. AFTER THAT...MUCH OF THE AREA IS EXPECTED TO REMAIN DRY FOR SUNDAY. THE ONLY EXCEPTION BEING MODELS TRENDING TOWARDS AN AREA OF CLOUDS AND SHOWERS OVER NORTHERN WISCONSIN AROUND MIDDAY SUNDAY AS A WEAK JET STREAK SWINGS THROUGH ON THE BACK SIDE OF THE 500MB TROUGH. WITH MODERATELY UNSTABLE MIDLEVEL LAPSE RATES AROUND 7C AND THE GFS/GEM PUTTING PRECIP OVER THE NORTH SUNDAY MORNING THROUGH THE EARLY AFTERNOON...ADDED SLIGHT CHANCES OF SHOWERS OVER THIS AREA UNTIL MIDDAY PER MODEL TRENDS. SKIES WILL CLEAR OUT BY SUNDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE AREA. GUIDANCE HAS TRENDED COOLER SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH TEMPERATURES...SO BROUGHT MAX/MIN TEMPS DOWN A FEW DEGREES. WITH CLEARING SKIES AND CAA IN PLACE...MIN TEMPS COULD GET RELATIVELY COLD SUNDAY NIGHT. ...MONDAY THROUGH FRIDAY... HIGH PRESSURE HOLDS OVER WISCONSIN THROUGH MUCH OF THE PERIOD WITH WEAK IMPULSES MOVING THROUGH THE MEAN ZONAL FLOW. A COUPLE OF CHANCES FOR PRECIP IN THE EXTENDED...BEGINNING WITH MONDAY NIGHT INTO TUESDAY AS A WEAK COLD FRONT PUSHES SOUTHEAST THROUGH THE STATE. BETTER CHANCE LOOKS TO BE THURSDAY INTO FRIDAY AS A STRONGER SHORTWAVE SWINGS THROUGH NORTHERN WISCONSIN. TEMPERATURES SHOULD RETURN TO NEAR NORMAL OR SLIGHTLY ABOVE NORMAL LEVELS THROUGH NEXT WEEK. && .AVIATION...SUBTLE BOUNDARY LIFTING OVER CENTRAL WISCONSIN THIS EVENING WAS PRODUCING VERY ISOLATED SHOWERS AND STORMS AT TIMES. THE SHOWERS AND STORMS DURATION WERE RELATIVELY SHORT LIVED. OTHERWISE DEBRIS CLOUDS AND CONVECTION FROM A CLUSTER OF SHOWERS AND STORMS OVER THE DAKOTAS MAY WORK INTO THE WESTERN HALF OF THE STATE OVERNIGHT. MVFR CIGS MAY WORK INTO CENTRAL AND NORTH CENTRAL WISCONSIN OVERNIGHT. MAIN DYNAMICS WITH DEEP SHORT WAVE TROUGH AND COLD FRONT WILL PASS OVER THE STATE ON SATURDAY FOR A FEW ROUNDS OF SHOWERS AND STORMS. IFR CONDITIONS CAN BE EXPECTED WITH THE STRONGER STORMS. A FEW STORMS MAY BE SEVERE OVER CENTRAL AND NORTH CENTRAL WISCONSIN EARLY TO MID AFTERNOON AND THEN LATER AFTERNOON AND EVENING OVER EASTERN WISCONSIN. TDH && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
651 PM CDT FRI AUG 3 2012 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TODAY THROUGH SATURDAY. IN THE NEAR-TERM...SC SLOWLY DISSIPATED DURING THE DAY THANKS TO EASTERLY LOW-LEVEL FLOW. AS CONVECTIVE TEMP IS MET...CU FIELD DEVELOPS...AS SEEN ON LATEST VIS SATELLITE IMAGERY. BOTH 03/15Z RUNS OF HRRR AND RAP INDICATE ISOLATED CONVECTION IN NE WI BETWEEN 3 AND 6 PM...NOT UNLIKE YESTERDAY`S EARLY EVENING ISOLATED EVENT. BUT PROBABILITY TOO LOW TO INCLUDE IN GRIDS AT THIS TIME. SHARP UPPER TROUGH WILL PRODUCE GOOD UPPER DIFFLUENCE ACROSS MINNESOTA TONIGHT. THAT COUPLED WITH A MODEST LOW LEVEL JET SHOULD RESULT IN CONVECTION THAT COULD DRIFT INTO OUR WESTERN COUNTIES TOWARD MORNING. BOTH THE 03/12Z NAM AND GFS HINT AT THIS. MINIMUM TEMPERATURES SHOULD BE HELD UP ABOVE NORMAL ONCE AGAIN BY INCREASING CLOUD COVER. THE UPPER TROUGH MOVES INTO WESTERN WISCONSIN LATE SATURDAY. WHILE DEBRIS FROM ANY LEFTOVER CONVECTION WILL HAVE TO BE DEALT WITH...AIRMASS SHOULD DESTABILIZE SUFFICIENTLY WITH PRESENCE OF UPPER TROF TO INCREASE THUNDERSTORM THREAT AFTER 18Z. INCREASING DEEP SHEAR AND INSTABILITY INDICATE THREAT FOR SEVERE STORMS...THOUGH BEST CHANCE WOULD BE ACROSS SE THIRD OF WI...PER SPC DAY 2 OUTLOOK. AS IS USUALLY THE CASE...SEVERE THREAT WILL LARGELY HINGE ON THE TIMING OF THE SYSTEM AND THE DEGREE OF INSTABILITY SATURDAY AFTERNOON. TEMPS ON SATURDAY SHOULD REACH NEAR 90 ACROSS THE FOX VALLEY WITH ANY AMOUNT OF SUNSHINE. TEMPS IN THE LOWER 80S ACROSS THE FAR N WITH MORE CLOUDS AND PRECIP TO START THE DAY. ALL-IN-ALL...PREVIOUS FORECAST WAS IN GOOD SHAPE SO ONLY MINOR TWEAKING WAS NEEDED. .LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY. MAIN FORECAST CONCERN WILL BE THE EXITING SYSTEM SUNDAY NIGHT AND CLOUDS/LINGERING PRECIP OVER THE NORTH SUNDAY MIDDAY. ...SATURDAY NIGHT AND SUNDAY... COLD FRONT SHOULD BE IN THE VICINITY OF THE FOX VALLEY AROUND 00Z SUNDAY. MODEL CONSENSUS HAS TRENDED TOWARDS THIS SLOWER SOLUTION...SO KEPT PRECIP IN THE CWA LONGER THAN THE PREVIOUS FORECAST. THE COLD FRONT SHOULD MOVE OUT WITH THE UPPER LEVEL SYSTEM AND CLEAR THE AREA BETWEEN 09-12Z SUNDAY. GFS/ECMWF HAVE BEEN THE SLOWEST AND KEEP PRECIP AROUND THE LONGEST...THEREFORE HAVE SHOWERS CONTINUING ON THE LAKESHORE UNTIL SUNDAY MORNING. AFTER THAT...MUCH OF THE AREA IS EXPECTED TO REMAIN DRY FOR SUNDAY. THE ONLY EXCEPTION BEING MODELS TRENDING TOWARDS AN AREA OF CLOUDS AND SHOWERS OVER NORTHERN WISCONSIN AROUND MIDDAY SUNDAY AS A WEAK JET STREAK SWINGS THROUGH ON THE BACK SIDE OF THE 500MB TROUGH. WITH MODERATELY UNSTABLE MIDLEVEL LAPSE RATES AROUND 7C AND THE GFS/GEM PUTTING PRECIP OVER THE NORTH SUNDAY MORNING THROUGH THE EARLY AFTERNOON...ADDED SLIGHT CHANCES OF SHOWERS OVER THIS AREA UNTIL MIDDAY PER MODEL TRENDS. SKIES WILL CLEAR OUT BY SUNDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE AREA. GUIDANCE HAS TRENDED COOLER SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH TEMPERATURES...SO BROUGHT MAX/MIN TEMPS DOWN A FEW DEGREES. WITH CLEARING SKIES AND CAA IN PLACE...MIN TEMPS COULD GET RELATIVELY COLD SUNDAY NIGHT. ...MONDAY THROUGH FRIDAY... HIGH PRESSURE HOLDS OVER WISCONSIN THROUGH MUCH OF THE PERIOD WITH WEAK IMPULSES MOVING THROUGH THE MEAN ZONAL FLOW. A COUPLE OF CHANCES FOR PRECIP IN THE EXTENDED...BEGINNING WITH MONDAY NIGHT INTO TUESDAY AS A WEAK COLD FRONT PUSHES SOUTHEAST THROUGH THE STATE. BETTER CHANCE LOOKS TO BE THURSDAY INTO FRIDAY AS A STRONGER SHORTWAVE SWINGS THROUGH NORTHERN WISCONSIN. TEMPERATURES SHOULD RETURN TO NEAR NORMAL OR SLIGHTLY ABOVE NORMAL LEVELS THROUGH NEXT WEEK. && .AVIATION...SUBTLE BOUNDARY LIFTING OVER CENTRAL WISCONSIN THIS EVENING WAS PRODUCING VERY ISOLATED SHOWERS AND STORMS AT TIMES. THE SHOWERS AND STORMS DURATION WERE RELATIVELY SHORT LIVED. OTHERWISE DEBRIS CLOUDS AND CONVECTION FROM A CLUSTER OF SHOWERS AND STORMS OVER THE DAKOTAS MAY WORK INTO THE WESTERN HALF OF THE STATE OVERNIGHT. MVFR CIGS MAY WORK INTO CENTRAL AND NORTH CENTRAL WISCONSIN OVERNIGHT. MAIN DYNAMICS WITH DEEP SHORT WAVE TROUGH AND COLD FRONT WILL PASS OVER THE STATE ON SATURDAY FOR A FEW ROUNDS OF SHOWERS AND STORMS. IFR CONDITIONS CAN BE EXPECTED WITH THE STRONGER STORMS. A FEW STORMS MAY BE SEVERE OVER CENTRAL AND NORTH CENTRAL WISCONSIN EARLY TO MID AFTERNOON AND THEN LATER AFTERNOON AND EVENING OVER EASTERN WISCONSIN. TDH && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT THU AUG 2 2012 .SHORT TERM... 334 PM CDT THU AUG 2 2012 OVERALL NOT MANY CHANGES TO THE ONGOING FORECAST. SIGHTS ARE ON SATURDAY SYSTEM MOVING THROUGH THE REGION WITH SEVERE WEATHER THREAT STILL LOOKING LIKE EASTERN PART OF WI. 02.12Z RAOB DATA SUGGESTS THE TAIL OF TWO AIR MASSES BETWEEN KMPX AND KDVN. KDVN IS REMARKABLY DRY AND THIS IS LEADING TO THE DEW POINT CRASHES INTO THE 50S SEEN NEAR KDBQ AND SOUTH AS MIXING HAS INCREASED THIS AFTERNOON. STILL A WEAKLY CONVERGENCE FLOW IN LOW-LEVELS ALONG AN INVERTED TROUGH FROM NEAR KDLL-KOVS-KMCW. SOME CUMULUS LOOKING MORE ENHANCED...WITH MLCAPE IN THE 1500 J/KG RANGE. MORE SIGNIFICANT TROUGH EXPECTED TO AFFECT THE REGION SATURDAY IS SEEN IN GOES WATER VAPOR OVER BRITISH COLUMBIA AND ALBERTA WITH A TROPOPAUSE LEVEL DOWN TO 500 MB PER THE 02.19Z RAP ANALYSIS. CONVECTION ALREADY BECOMING ACTIVE DOWNSTREAM OVER WY/MT/ND IN THE DIFFLUENT FLOW AND HEIGHT FALL REGION. WITH SUCH WEAK CONVERGENCE AND MID-UPPER LEVEL SUPPORT THIS EVENING ACROSS NE IA AND SWRN WI...HAVE DECIDED TO KEEP IT DRY THIS EVENING ACROSS THE SOUTH. LATEST HRRR RUNS ARE SLIGHTLY LIGHTER WITH CONVECTIVE CELL DEVELOPMENT DOWN THERE...MORE TOWARD AN ENHANCED CUMULUS SOLUTION. HRRR SUGGESTS THE INVERTED TROUGH OVER ERN WI MORE VIGOROUS IN EVENING. THERE COULD BE A STORM OR TWO THAT DEVELOP BUT WE DO NOT SEE IT AS ENOUGH TO ADD IT TO THE FORECAST ACROSS OUR FORECAST AREA. EVENING FORECASTER CAN MONITOR. FRIDAY APPEARS TO BE A NICE DAY WITH THE RIDGE BUILDING IN FROM THE GREAT LAKES AND SE FLOW IN THE LOW-LEVELS. WILL NEED TO BE WATCHING THE SYSTEM TO THE SOUTH WHICH IS CUTOFF FROM THE MAIN FLOW AND HAS SOME CAPE BUILDING ACROSS IL AND MOISTURE TRANSPORT HAS SOME SIGNAL OF CONVERGENCE ACROSS NORTHERN IL. THIS MAY BRING SOME SHRA ACTIVITY NEAR SOUTHERN WI AND THE FORECAST AREA. IDEA IS THAT DEWPOINTS ARE PROBABLY OVERFORECAST IN THE GUIDANCE WITH SUCH A DRY AIR MASS IN PLACE. LARGER SCALE TROUGH MOVING EAST INTO THE NORTHERN PLAINS ON FRIDAY WILL INITIATE CONVECTION IN THE DAKOTAS THAT WILL ROLL EAST OVERNIGHT ON MOISTURE TRANSPORT AND DYNAMICS. STILL HAVE SOME LIMITED CAPE TO THE WEST OVERNIGHT TO SUGGEST A DECAYING TSRA/SHRA ACROSS MN/IA POSSIBLY AFFECTING SERN MN/WRN MN LATE FRIDAY NIGHT. HAVE INCREASED RAIN CHANCES A BIT FOR THOSE AREAS AFTER MIDNIGHT. IN THE BIG PICTURE...THE 02.12Z NAM/GEM/GFS/ECMWF ARE IN AGREEMENT ON THE TIMING OF THE LARGER SCALE TROUGH MOVING ACROSS THE GREAT LAKES SATURDAY AND SATURDAY NIGHT. THE DETAILS ARE DIFFERENT HOWEVER WITH THE 02.12Z NAM SUGGESTING A SIMILAR IDEA AS THE 02.00Z/12Z ECMWF OF A SECONDARY SURFACE LOW MOVING NE ALONG THE FRONT SATURDAY TOWARD KMKE FROM IL. THE EC SOLUTIONS ARENT QUITE AS AGGRESSIVE AS THE NAM WITH THE STRENGTH OF THE SECOND LOW...BUT THEY HAVE SIMILAR SENSIBLE WEATHER OUTCOMES BUT LESS RAINFALL. THIS LOW SHIFTING NE WOULD ELICIT A GREATER CHANCE OF RAIN EAST OF THE MISS RIVER FOR SATURDAY AND SLOW THE EASTWARD MOVING COLD FRONT AND DRYING TO ALLOW MORE RAIN SATURDAY EVENING IN CENTRAL WI. EVEN WITH THESE DIFFERENCE IN THE DEVELOPMENT OF A SECONDARY LOW...THE CONSENSUS CAPE IS MAINLY EAST OF THE FORECAST AREA FOR A SATURDAY SEVERE WEATHER THREAT. THIS AGREES WITH THE SPC DAY 3 SLIGHT RISK FOR EASTERN WI. ANALYSIS OF THE SOUNDINGS OVER THE FORECAST AREA SUGGEST THAT ELEVATED INSTABILITY IS REALLY THE ONLY TSRA THREAT WITH THE LOWEST CIN VALUES AROUND 100 J/KG LATE MORNING IN SWRN WI PER 02.12Z NAM. 02.12Z GFS A BIT SLOWER WITH FRONT ALLOWING A BIT MORE WARMING AND INSTABILITY...WITH ML CAPE IN THE 1800 J/KG AREA AND CIN NEAR 50 J/KG. SO...THE MAIN THREAT DOES APPEAR TO BE EAST. BUT...ANY SLOWING TO THE FRONT WOULD ALLOW SWRN-CENTRAL WI TO GET INTO A WIND AND HAIL THREAT. HAVE INCREASED RAIN CHANCES FOR SATURDAY A BIT MORE AND LOWERED HIGH TEMPERATURES BY 3-5F WITH MORE CLOUD. ALSO HAVE INCREASED RAIN CHANCES A BIT WESTWARD SATURDAY EVENING TO ALLOW FOR A SLOWER SECONDARY LOW DEVELOPMENT ALONG THE FRONT. THE 02.12Z ECMWF HAS TAKEN ABOUT A 4-6 HOUR STEP SLOWER THAN THE PREVIOUS RUN...SO SEVERE WEATHER FOR WESTERN WI IS STILL NOT RULED OUT. .LONG TERM...SUNDAY NIGHT THROUGH THURSDAY 335 PM CDT THU AUG 2 2012 A DRIER PERIOD IS SEEN HERE AS THE LARGE SCALE TROUGH DEEPENS OVER HUDSONS BAY AND IMPACTS THE WESTERN GREAT LAKES WITH LOWER HEIGHTS AND NORTHWEST FLOW. 02.12Z ECMWF IS MORE AGGRESSIVE WITH THE TROUGH DEPTH OVER THE AREA SUGGESTING A BIT COOLER THAN THE 02.12Z GFS. THE 02.12Z GEM WOULD AGREE MORE ON THE GFS SIDE...HOWEVER IT MAY BE OFF IN ITS TIMING AS IT HAS A DEEPER SHORTWAVE TROUGH ROTATING SOUTHWARD ABOUT 24 HOURS AFTER THE 02.12Z ECMWF SOLUTION. IN EITHER CASE...THE SENSIBLE WEATHER IS MAINLY A COOLER FORECAST IN THE ECMWF. THUS...HAVE TAKEN A FEW DEGREES OFF A CONSENSUS FORECAST. THE 02.00Z GFS ENSEMBLE DATA DID SHOW HIGHER SIGNS OF SPREAD IN THE MID-WEEK HIGHS WITH A 78-87F RANGE...AND THE OPERATIONAL GFS MOS WAS ON THE WARM SIDE. STILL THINK THE 02.12Z GFS IS ON THE WARM SIDE AND HAVE UNDERCUT THOSE VALUES. FORECAST TEMPERATURES WILL BE PLEASANT AND NEAR NORMAL. PRECIPITATION CHANCES ARE SMALL THROUGH THE WEEK AND HARD TO TIME OUT AT THIS POINT. && .AVIATION... 600 PM CDT THU AUG 2 2012 HIGH PRESSURE OVER SOUTHEAST CANADA WILL BE THE MAIN WEATHER INFLUENCE FOR THE REGION TONIGHT...RESULTING IN MOSTLY CLEAR SKIES AND LIGHT SFC WINDS. ADD RAINS FROM LAST NIGHT/EARLY THIS MORNING AND THE SETUP WOULD SEEM CONDUCIVE TO AREAS OF FOG. HOWEVER...BUFKIT RAP/NAM12 WIND FIELDS FAVOR AROUND 10 KTS WITHIN THE FIRST COUPLE HUNDRED FEET TONIGHT...AN INHIBITOR TO WIDESPREAD FOG. AFTERNOON SUNSHINE HAS ALSO LED TO A QUICK BUMP UPWARD IN THE TEMPS...AND MIXING RESULTING IN DRYING OF THE SFC TD. LARGER T/TD SPREAD TO OVERCOME TONIGHT AS A RESULT. WILL STAY WITH 5SM BR MENTION IN TAFS FOR NOW AND MONITOR TRENDS THROUGH THE EVENING. THINK THE GREATER THREAT FOR SUB 1SM WOULD LIE IN THE RIVER VALLEYS...AND THUS AT KLSE. VFR CONDITIONS SHOULD ABOUND FOR MOST OF FRIDAY...WITH SOME INCREASING CLOUDS FROM THE WEST IN THE EVENING...AHEAD OF AN APPROACHING COLD FRONT. THIS FRONT WILL BRING SOME SHRA/TS CHANCES...MOSTLY AFTER 12Z SAT. && .ARX WATCHES/WARNINGS/ADVISORIES... 335 PM CDT THU AUG 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM....BAUMGARDT AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
354 PM CDT THU AUG 2 2012 .SHORT TERM... TONIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM. AREA OF RAIN SHOWERS CONTINUES TO SHIFT EAST ACROSS THE NORTHERN COUNTIES OF THE FORECAST AREA. THIS AREA AIDED BY MODEST 850MB/700MB MOISTURE POOLING/CONVERGENCE AND LOW LEVEL FRONTOGENESIS RESPONSE. THIS AREA SHOULD CONTINUE TO SHIFT EASTWARD THROUGH THE REST OF THE AFTERNOON ACROSS THE NORTHEAST COUNTIES...ALONG WITH ASSOCIATED UPWARD VERTICAL MOTION. WEAK COLD FRONT FROM WEST CENTRAL TO NORTHEAST WISCONSIN IS EXPECTED TO SAG SOUTHWARD THROUGH THE AREA THIS EVENING...THEN TO THE SOUTH LATER TONIGHT. AREA OF WEAK TO MODEST 850MB CONFLUENCE ALSO SHIFTS SOUTH INTO THE AREA AND LINGERS THROUGH THE NIGHT. AREA FORECAST SOUNDINGS SHOWING CAP MIXING OUT ACROSS SOUTHERN PORTIONS OF THE AREA WHERE CLOUDS MOVED AWAY...WITH AROUND 500 J/KG MEAN LAYER CAPE. CLOUDIER AREAS WOULD HAVE LESS CAPE AND MORE CAPPING. CAPE BECOMES MORE ELEVATED TONIGHT AND WOULD HAVE TO BE REACHED BY ELEVATED PARCELS. HRRR MODEL SHOWING WIDELY SCATTERED CELLS AT BEST DEVELOPING LATE THIS AFTERNOON INTO THE EARLY EVENING. KEPT POPS FOR LATE THIS AFTERNOON INTO TONIGHT WITH THE ABOVE FORCING MECHANISMS MOVING IN. A GOOD PORTION OF THE AREA LIKELY WILL BE DRY. SCATTERED MID LEVEL CLOUDS EXPECTED TONIGHT INTO FRIDAY. DRIER AIR WORKS INTO THE AREA FRIDAY ON EASTERLY WINDS. KEPT DRY FORECAST GOING FOR FRIDAY WITH DECENT CAP ACROSS THE AREA. LOWS TONIGHT SHOULD FALL TO THE MID TO UPPER 60S...WITH ANOTHER VERY WARM DAY IN THE UPPER 80S TO LOWER 90S AWAY FROM THE LAKE. EAST WINDS KEEPS HIGHS COOLER NEAR LAKESHORE. FRIDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM TO HIGH A FAIRLY SHARP UPPER TROUGH WILL TRACK EWD FROM THE NRN HIGH PLAINS THROUGH THE GREAT LAKES DURING THIS PERIOD WITH AN ORGANIZED LOW PRESSURE AREA MOVING ALONG THE US/CANADIAN BORDER. THETAE ADVECTION WILL BOOST PWS TO NEARLY ONE INCH FOR SAT AFTERNOON AND EVENING AHEAD OF AND ALONG THE COLD FRONT ALONG WITH MODERATE INSTABILITY AND WIND SHEAR. THUNDERSTORMS WILL LIKELY DEVELOP SAT AFTERNOON OVER WRN WI AND THEN MOVE EWD THROUGH SAT EVENING. A SLIGHT RISK OF SEVERE THUNDERSTORMS IS FORECAST BY SPC AND LOOKS GOOD. COLD AND DRY ADVECTION WILL THEN PREVAIL ON SUNDAY WITH A PLEASANT DAY FOLLOWED BY HIGH PRESSURE THROUGH MON NT. .LONG TERM... SRN WI WILL BE ON THE SRN PERIPHERY OF NW FLOW WITH ONLY A WEAK COOL FRONT TO POSSIBLY BE IN THE VICINITY OF SRN WI FROM TUE-WED. THUS ONLY SLIGHT CHANCE OF TSTORMS DURING THAT TIME. TEMPS WILL BE AT LEAST SLIGHTLY ABOVE NORMAL NEXT WEEK. && .AVIATION/00Z TAFS/... VFR CONDITIONS EXPECTED THROUGH FRIDAY ACROSS TAF SITES. CURRENT SHOWER ACTIVITY WILL CONTINUE TO REMAIN NORTH OF TAF SITES. EXPECT SCATTERED TO BROKEN MID LEVEL CLOUDS THROUGH THE LATE AFTERNOON. EAST/SOUTHEAST WINDS ARE EXPECTED TO LINGER AT MILWAUKEE AND REACH WAUKESHA BY 22Z. LIGHT WINDS ARE EXPECTED TO LINGER AT MADISON. WEAK COLD FRONT SLIDING SOUTH TOWARD THE AREA LATE THIS AFTERNOON...AND THROUGH THE AREA THIS EVENING. FRONT WOULD BRING MAINLY SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE EVENING...AND A SHOWER AFTER MIDNIGHT. HOWEVER...TOO MUCH UNCERTAINTY RIGHT NOW TO MENTION IN TAFS. LIGHT EAST TO NORTHEAST WINDS TONIGHT SHOULD REMAIN EASTERLY ON FRIDAY ACROSS TAF SITES...WITH FEW TO SCATTERED MID LEVEL CLOUDS. EASTERLY WINDS BRING DRIER AIR INTO THE AREA LATER TONIGHT AND FRIDAY...WITH QUIET WEATHER EXPECTED. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TONIGHT/FRIDAY AND AVIATION/MARINE...WOOD FRIDAY NIGHT THROUGH THURSDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
335 PM CDT THU AUG 2 2012 .SHORT TERM... 334 PM CDT THU AUG 2 2012 OVERALL NOT MANY CHANGES TO THE ONGOING FORECAST. SIGHTS ARE ON SATURDAY SYSTEM MOVING THROUGH THE REGION WITH SEVERE WEATHER THREAT STILL LOOKING LIKE EASTERN PART OF WI. 02.12Z RAOB DATA SUGGESTS THE TAIL OF TWO AIR MASSES BETWEEN KMPX AND KDVN. KDVN IS REMARKABLY DRY AND THIS IS LEADING TO THE DEW POINT CRASHES INTO THE 50S SEEN NEAR KDBQ AND SOUTH AS MIXING HAS INCREASED THIS AFTERNOON. STILL A WEAKLY CONVERGENCE FLOW IN LOW- LEVELS ALONG AN INVERTED TROUGH FROM NEAR KDLL-KOVS-KMCW. SOME CUMULUS LOOKING MORE ENHANCED...WITH MLCAPE IN THE 1500 J/KG RANGE. MORE SIGNIFICANT TROUGH EXPECTED TO AFFECT THE REGION SATURDAY IS SEEN IN GOES WATER VAPOR OVER BRITISH COLUMBIA AND ALBERTA WITH A TROPOPAUSE LEVEL DOWN TO 500 MB PER THE 02.19Z RAP ANALYSIS. CONVECTION ALREADY BECOMING ACTIVE DOWNSTREAM OVER WY/MT/ND IN THE DIFFLUENT FLOW AND HEIGHT FALL REGION. WITH SUCH WEAK CONVERGENCE AND MID-UPPER LEVEL SUPPORT THIS EVENING ACROSS NE IA AND SWRN WI...HAVE DECIDED TO KEEP IT DRY THIS EVENING ACROSS THE SOUTH. LATEST HRRR RUNS ARE SLIGHTLY LIGHTER WITH CONVECTIVE CELL DEVELOPMENT DOWN THERE...MORE TOWARD AN ENHANCED CUMULUS SOLUTION. HRRR SUGGESTS THE INVERTED TROUGH OVER ERN WI MORE VIGOROUS IN EVENING. THERE COULD BE A STORM OR TWO THAT DEVELOP BUT WE DO NOT SEE IT AS ENOUGH TO ADD IT TO THE FORECAST ACROSS OUR FORECAST AREA. EVENING FORECASTER CAN MONITOR. FRIDAY APPEARS TO BE A NICE DAY WITH THE RIDGE BUILDING IN FROM THE GREAT LAKES AND SE FLOW IN THE LOW-LEVELS. WILL NEED TO BE WATCHING THE SYSTEM TO THE SOUTH WHICH IS CUTOFF FROM THE MAIN FLOW AND HAS SOME CAPE BUILDING ACROSS IL AND MOISTURE TRANSPORT HAS SOME SIGNAL OF CONVERGENCE ACROSS NORTHERN IL. THIS MAY BRING SOME SHRA ACTIVITY NEAR SOUTHERN WI AND THE FORECAST AREA. IDEA IS THAT DEWPOINTS ARE PROBABLY OVERFORECAST IN THE GUIDANCE WITH SUCH A DRY AIR MASS IN PLACE. LARGER SCALE TROUGH MOVING EAST INTO THE NORTHERN PLAINS ON FRIDAY WILL INITIATE CONVECTION IN THE DAKOTAS THAT WILL ROLL EAST OVERNIGHT ON MOISTURE TRANSPORT AND DYNAMICS. STILL HAVE SOME LIMITED CAPE TO THE WEST OVERNIGHT TO SUGGEST A DECAYING TSRA/SHRA ACROSS MN/IA POSSIBLY AFFECTING SERN MN/WRN MN LATE FRIDAY NIGHT. HAVE INCREASED RAIN CHANCES A BIT FOR THOSE AREAS AFTER MIDNIGHT. IN THE BIG PICTURE...THE 02.12Z NAM/GEM/GFS/ECMWF ARE IN AGREEMENT ON THE TIMING OF THE LARGER SCALE TROUGH MOVING ACROSS THE GREAT LAKES SATURDAY AND SATURDAY NIGHT. THE DETAILS ARE DIFFERENT HOWEVER WITH THE 02.12Z NAM SUGGESTING A SIMILAR IDEA AS THE 02.00Z/12Z ECMWF OF A SECONDARY SURFACE LOW MOVING NE ALONG THE FRONT SATURDAY TOWARD KMKE FROM IL. THE EC SOLUTIONS ARENT QUITE AS AGGRESSIVE AS THE NAM WITH THE STRENGTH OF THE SECOND LOW...BUT THEY HAVE SIMILAR SENSIBLE WEATHER OUTCOMES BUT LESS RAINFALL. THIS LOW SHIFTING NE WOULD ELICIT A GREATER CHANCE OF RAIN EAST OF THE MISS RIVER FOR SATURDAY AND SLOW THE EASTWARD MOVING COLD FRONT AND DRYING TO ALLOW MORE RAIN SATURDAY EVENING IN CENTRAL WI. EVEN WITH THESE DIFFERENCE IN THE DEVELOPMENT OF A SECONDARY LOW...THE CONSENSUS CAPE IS MAINLY EAST OF THE FORECAST AREA FOR A SATURDAY SEVERE WEATHER THREAT. THIS AGREES WITH THE SPC DAY 3 SLIGHT RISK FOR EASTERN WI. ANALYSIS OF THE SOUNDINGS OVER THE FORECAST AREA SUGGEST THAT ELEVATED INSTABILITY IS REALLY THE ONLY TSRA THREAT WITH THE LOWEST CIN VALUES AROUND 100 J/KG LATE MORNING IN SWRN WI PER 02.12Z NAM. 02.12Z GFS A BIT SLOWER WITH FRONT ALLOWING A BIT MORE WARMING AND INSTABILITY...WITH ML CAPE IN THE 1800 J/KG AREA AND CIN NEAR 50 J/KG. SO...THE MAIN THREAT DOES APPEAR TO BE EAST. BUT...ANY SLOWING TO THE FRONT WOULD ALLOW SWRN-CENTRAL WI TO GET INTO A WIND AND HAIL THREAT. HAVE INCREASED RAIN CHANCES FOR SATURDAY A BIT MORE AND LOWERED HIGH TEMPERATURES BY 3-5F WITH MORE CLOUD. ALSO HAVE INCREASED RAIN CHANCES A BIT WESTWARD SATURDAY EVENING TO ALLOW FOR A SLOWER SECONDARY LOW DEVELOPMENT ALONG THE FRONT. THE 02.12Z ECMWF HAS TAKEN ABOUT A 4-6 HOUR STEP SLOWER THAN THE PREVIOUS RUN...SO SEVERE WEATHER FOR WESTERN WI IS STILL NOT RULED OUT. .LONG TERM...SUNDAY NIGHT THROUGH THURSDAY 335 PM CDT THU AUG 2 2012 A DRIER PERIOD IS SEEN HERE AS THE LARGE SCALE TROUGH DEEPENS OVER HUDSONS BAY AND IMPACTS THE WESTERN GREAT LAKES WITH LOWER HEIGHTS AND NORTHWEST FLOW. 02.12Z ECMWF IS MORE AGGRESSIVE WITH THE TROUGH DEPTH OVER THE AREA SUGGESTING A BIT COOLER THAN THE 02.12Z GFS. THE 02.12Z GEM WOULD AGREE MORE ON THE GFS SIDE...HOWEVER IT MAY BE OFF IN ITS TIMING AS IT HAS A DEEPER SHORTWAVE TROUGH ROTATING SOUTHWARD ABOUT 24 HOURS AFTER THE 02.12Z ECMWF SOLUTION. IN EITHER CASE...THE SENSIBLE WEATHER IS MAINLY A COOLER FORECAST IN THE ECMWF. THUS...HAVE TAKEN A FEW DEGREES OFF A CONSENSUS FORECAST. THE 02.00Z GFS ENSEMBLE DATA DID SHOW HIGHER SIGNS OF SPREAD IN THE MID-WEEK HIGHS WITH A 78-87F RANGE...AND THE OPERATIONAL GFS MOS WAS ON THE WARM SIDE. STILL THINK THE 02.12Z GFS IS ON THE WARM SIDE AND HAVE UNDERCUT THOSE VALUES. FORECAST TEMPERATURES WILL BE PLEASANT AND NEAR NORMAL. PRECIPITATION CHANCES ARE SMALL THROUGH THE WEEK AND HARD TO TIME OUT AT THIS POINT. && .AVIATION...THROUGH 18Z FRIDAY 1232 PM CDT THU AUG 2 2012 COLD FRONT WILL PUSH THROUGH THE TAF SITES BY 18Z...WITH A LIGHT NORTHWEST WIND IN ITS WAKE. EXTENSIVE LAYER OF MID LEVEL CLOUDS WILL AFFECT BOTH SITES THROUGH MUCH OF THE AFTERNOON...WITH SCATTERED TO BROKEN CONDITIONS. CLOUDS WILL CLEAR OUT THIS EVENING AND REMAIN CLEAR THROUGH 18Z FRIDAY. WITH THE OVERNIGHT RAIN...THERE IS SOME CONCERN FOR FOG TONIGHT. THE BIGGEST NEGATIVE FOR FOG FORMATION WILL BE WINDS. THE 02.12Z NAM SUGGEST WINDS WILL REMAIN IN THE 10 TO 15 KNOT RANGE LATE TONIGHT JUST ABOVE THE SURFACE. WILL HAVE TO MONITOR THIS CLOSE THROUGH THE EVENING HOURS AND IF THE WINDS LOOK TO BE LIGHTER WILL HAVE TO ADD MORE FOG TO THE TAFS. FOR THE 18Z TAFS WILL CONTINUE TO MENTION 5SM BR BETWEEN 07Z-14Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 335 PM CDT THU AUG 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1232 PM CDT THU AUG 2 2012 .SHORT TERM...TODAY THROUGH SATURDAY NIGHT 359 AM CDT THU AUG 2 2012 AT 3 AM...THE CLUSTER OF SHOWERS AND THUNDERSTORMS...THAT MOVED NORTH OF THE INTERSTATE 90 CORRIDOR FROM LAST EVENING INTO THE EARLY OVERNIGHT...WAS LOCATED ACROSS EAST-CENTRAL AND NORTHEAST WISCONSIN. THIS WAS ASSOCIATED WITH A 700 TO 500 MB TROUGH. THE 02.00Z MODELS ARE IN GOOD AGREEMENT THAT THIS SYSTEM WILL CONTINUE TO MOVE EAST AWAY FROM THE REGION THIS MORNING. FURTHER TO THE SOUTHWEST ANOTHER SHORT WAVE TROUGH WAS AIDING IN THE DEVELOPMENT OF A MESOSCALE CONVECTIVE COMPLEX ACROSS EASTERN NEBRASKA AND NORTHERN KANSAS. THIS SYSTEM IS FORECAST TO CONTINUE TO MOVE EAST ACROSS SOUTHERN IOWA AND MISSOURI THIS MORNING...AND SOUTHERN ILLINOIS THIS AFTERNOON. IN BETWEEN THESE TWO WAVES...THERE IS A WEAK COLD FRONT EXTENDING FROM MENOMINEE TO CHARLES CITY IOWA. THE LATEST RAP CONTINUES TO SHOW THAT THE 900 TO 600 MB FRONTOGENESIS WILL SLOWLY WEAKEN THIS MORNING. THIS FRONTOGENESIS ALONG WITH WEAK MOISTURE CONVERGENCE WILL AID IN THE IN THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS MORNING. A 700 MB SPEED MAXIMUM MOVING THROUGH THE REGION EARLY THIS MORNING IS HELPING TO ENHANCE THE 0-3 KM SHEAR INTO THE 35 TO 40 KNOT RANGE. AS A RESULT...THERE IS A POSSIBILITY THAT WE COULD HAVE A FEW THUNDERSTORMS BECOME SEVERE THROUGH 9 AM THIS MORNING. THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. FOR THIS AFTERNOON...THE WINDS ARE GENERALLY PARALLEL WITH THE FRONT. AS A RESULT...THERE IS LITTLE MOISTURE CONVERGENCE ALONG THIS BOUNDARY. AS A RESULT...NOT SOLD ON THE IDEA THAT WE WILL SEE THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THE NMM AND ARW ALSO SUPPORT THIS TOO. FROM FRIDAY NIGHT INTO SATURDAY NIGHT...THE MODELS ARE TRENDING SLOWER WITH THE COLD FRONTAL PASSAGE THROUGH THE FORECAST AREA. THE NAM/WRF IS THE FASTEST AND IT SHOWS THE FRONT THROUGH MUCH OF THE AREA BY NOON SATURDAY. MEANWHILE THE ECMWF AND GFS WOULD SUGGEST THAT THE COLD FRONT WILL MOVE INTO NORTHEAST IOWA AND SOUTHEAST MINNESOTA ON SATURDAY MORNING...AND THEN MOVE EAST THROUGH THE REMAINDER OF THE AREA EARLY SATURDAY AFTERNOON. DUE TO THIS SLOWER FRONTAL MOVEMENT...DELAYED THE PRECIPITATION CHANCES BY ABOUT 12 TO 18 HOURS. THE 0-3 KM ML CAPES AHEAD OF THIS FRONT CLIMB INTO THE 2 TO 3K RANGE. MEANWHILE THE BEST SHEAR IS LOCATED EITHER ON THE FRONT OR POST FRONTAL. AS RESULT...WILL HAVE TO WATCH FOR THE POTENTIAL OF A FEW THUNDERSTORMS BECOMING SUPERCELLS ALONG THE FRONT. AT THIS TIME...THE BEST CHANCE LOOKS TO BE ACROSS SOUTHERN AND EASTERN WISCONSIN. THIS IS DUE TO THESE AREAS HAVING A LONGER TIME TO BUILD UP INSTABILITY PRIOR TO THE FRONTAL PASSAGE. .LONG TERM...SUNDAY THROUGH THURSDAY 359 AM CDT THU AUG 2 2012 ON SUNDAY...A COLD POOL WILL MOVE EAST ACROSS NORTHEAST MINNESOTA AND NORTHERN WISCONSIN. THERE WILL BE LIKELY SOME SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH IT...BUT LIKE THE PAST COUPLE OF DAYS IT LOOKS LIKE THEY WILL BE NORTH OF THE FORECAST AREA. FROM SUNDAY NIGHT INTO TUESDAY...HIGH PRESSURE WILL PROVIDE DRY WEATHER AND SLIGHTLY ABOVE-NORMAL TEMPERATURES. BEYOND THIS TIME FRAME...THE GFS AND ECMWF DIFFER ON WHETHER ANOTHER CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE REGION. WITH THESE DIFFERENCES JUST KEPT THE SLIGHT CHANCES THAT WERE PRODUCED IN THE ALL BLEND. && .AVIATION...THROUGH 18Z FRIDAY 1232 PM CDT THU AUG 2 2012 COLD FRONT WILL PUSH THROUGH THE TAF SITES BY 18Z...WITH A LIGHT NORTHWEST WIND IN ITS WAKE. EXTENSIVE LAYER OF MID LEVEL CLOUDS WILL AFFECT BOTH SITES THROUGH MUCH OF THE AFTERNOON...WITH SCATTERED TO BROKEN CONDITIONS. CLOUDS WILL CLEAR OUT THIS EVENING AND REMAIN CLEAR THROUGH 18Z FRIDAY. WITH THE OVERNIGHT RAIN...THERE IS SOME CONCERN FOR FOG TONIGHT. THE BIGGEST NEGATIVE FOR FOG FORMATION WILL BE WINDS. THE 02.12Z NAM SUGGEST WINDS WILL REMAIN IN THE 10 TO 15 KNOT RANGE LATE TONIGHT JUST ABOVE THE SURFACE. WILL HAVE TO MONITOR THIS CLOSE THROUGH THE EVENING HOURS AND IF THE WINDS LOOK TO BE LIGHTER WILL HAVE TO ADD MORE FOG TO THE TAFS. FOR THE 18Z TAFS WILL CONTINUE TO MENTION 5SM BR BETWEEN 07Z-14Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 359 AM CDT THU AUG 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
628 AM CDT THU AUG 2 2012 .SHORT TERM...TODAY THROUGH SATURDAY NIGHT 359 AM CDT THU AUG 2 2012 AT 3 AM...THE CLUSTER OF SHOWERS AND THUNDERSTORMS...THAT MOVED NORTH OF THE INTERSTATE 90 CORRIDOR FROM LAST EVENING INTO THE EARLY OVERNIGHT...WAS LOCATED ACROSS EAST-CENTRAL AND NORTHEAST WISCONSIN. THIS WAS ASSOCIATED WITH A 700 TO 500 MB TROUGH. THE 02.00Z MODELS ARE IN GOOD AGREEMENT THAT THIS SYSTEM WILL CONTINUE TO MOVE EAST AWAY FROM THE REGION THIS MORNING. FURTHER TO THE SOUTHWEST ANOTHER SHORT WAVE TROUGH WAS AIDING IN THE DEVELOPMENT OF A MESOSCALE CONVECTIVE COMPLEX ACROSS EASTERN NEBRASKA AND NORTHERN KANSAS. THIS SYSTEM IS FORECAST TO CONTINUE TO MOVE EAST ACROSS SOUTHERN IOWA AND MISSOURI THIS MORNING...AND SOUTHERN ILLINOIS THIS AFTERNOON. IN BETWEEN THESE TWO WAVES...THERE IS A WEAK COLD FRONT EXTENDING FROM MENOMINEE TO CHARLES CITY IOWA. THE LATEST RAP CONTINUES TO SHOW THAT THE 900 TO 600 MB FRONTOGENESIS WILL SLOWLY WEAKEN THIS MORNING. THIS FRONTOGENESIS ALONG WITH WEAK MOISTURE CONVERGENCE WILL AID IN THE IN THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS MORNING. A 700 MB SPEED MAXIMUM MOVING THROUGH THE REGION EARLY THIS MORNING IS HELPING TO ENHANCE THE 0-3 KM SHEAR INTO THE 35 TO 40 KNOT RANGE. AS A RESULT...THERE IS A POSSIBILITY THAT WE COULD HAVE A FEW THUNDERSTORMS BECOME SEVERE THROUGH 9 AM THIS MORNING. THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. FOR THIS AFTERNOON...THE WINDS ARE GENERALLY PARALLEL WITH THE FRONT. AS A RESULT...THERE IS LITTLE MOISTURE CONVERGENCE ALONG THIS BOUNDARY. AS A RESULT...NOT SOLD ON THE IDEA THAT WE WILL SEE THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THE NMM AND ARW ALSO SUPPORT THIS TOO. FROM FRIDAY NIGHT INTO SATURDAY NIGHT...THE MODELS ARE TRENDING SLOWER WITH THE COLD FRONTAL PASSAGE THROUGH THE FORECAST AREA. THE NAM/WRF IS THE FASTEST AND IT SHOWS THE FRONT THROUGH MUCH OF THE AREA BY NOON SATURDAY. MEANWHILE THE ECMWF AND GFS WOULD SUGGEST THAT THE COLD FRONT WILL MOVE INTO NORTHEAST IOWA AND SOUTHEAST MINNESOTA ON SATURDAY MORNING...AND THEN MOVE EAST THROUGH THE REMAINDER OF THE AREA EARLY SATURDAY AFTERNOON. DUE TO THIS SLOWER FRONTAL MOVEMENT...DELAYED THE PRECIPITATION CHANCES BY ABOUT 12 TO 18 HOURS. THE 0-3 KM ML CAPES AHEAD OF THIS FRONT CLIMB INTO THE 2 TO 3K RANGE. MEANWHILE THE BEST SHEAR IS LOCATED EITHER ON THE FRONT OR POST FRONTAL. AS RESULT...WILL HAVE TO WATCH FOR THE POTENTIAL OF A FEW THUNDERSTORMS BECOMING SUPERCELLS ALONG THE FRONT. AT THIS TIME...THE BEST CHANCE LOOKS TO BE ACROSS SOUTHERN AND EASTERN WISCONSIN. THIS IS DUE TO THESE AREAS HAVING A LONGER TIME TO BUILD UP INSTABILITY PRIOR TO THE FRONTAL PASSAGE. .LONG TERM...SUNDAY THROUGH THURSDAY 359 AM CDT THU AUG 2 2012 ON SUNDAY...A COLD POOL WILL MOVE EAST ACROSS NORTHEAST MINNESOTA AND NORTHERN WISCONSIN. THERE WILL BE LIKELY SOME SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH IT...BUT LIKE THE PAST COUPLE OF DAYS IT LOOKS LIKE THEY WILL BE NORTH OF THE FORECAST AREA. FROM SUNDAY NIGHT INTO TUESDAY...HIGH PRESSURE WILL PROVIDE DRY WEATHER AND SLIGHTLY ABOVE-NORMAL TEMPERATURES. BEYOND THIS TIME FRAME...THE GFS AND ECMWF DIFFER ON WHETHER ANOTHER CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE REGION. WITH THESE DIFFERENCES JUST KEPT THE SLIGHT CHANCES THAT WERE PRODUCED IN THE ALL BLEND. && .AVIATION...TODAY AND TONIGHT 628 AM CDT THU AUG 2 2012 FORECAST CONCERNS ARE FOCUSED ON NEAR-TERM PRECIPITATION CHANCES...THEN FOG POTENTIAL OVERNIGHT. SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY LINGERING ACROSS SOUTHERN MINNESOTA INTO WESTERN WISCONSIN...WITH A SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS MOVING THROUGH. CONFIDENCE IS HIGH THAT THESE SHOWERS/STORMS WILL WEAKEN AND MOVE SOUTHEAST OF KRST/KLSE BY MID TO LATE MORNING AS FRONT FINALLY PUSHES THROUGH. BROKEN MID LEVEL CLOUDS WILL GRADUALLY ERODE BY LATE AFTERNOON AS HIGH PRESSURE BUILDS ACROSS NORTHERN MINNESOTA/WISCONSIN. NEXT CONCERN IS OVERNIGHT FOG POTENTIAL. GIVEN RECENT RAINFALL ACROSS THE AREA...COOLER AIR TEMPERATURES...AND BUILDING HIGH PRESSURE...WOULD EXPECT AT LEAST SOME PATCHY FOG TO DEVELOP. CONFIDENCE IS NOT HIGH ENOUGH HOWEVER TO INTRODUCE IFR OR LOWER CONDITIONS AS SUGGESTED BY SOME FORECAST MODEL GUIDANCE. WINDS IN THE LOWEST LEVELS COULD BE HIGH ENOUGH TO KEEP BOUNDARY LAYER MIXED SO FOR NOW HAVE INCLUDED A MVFR VISIBILITY AND LATER FORECASTS CAN EVALUATE POTENTIAL. && .ARX WATCHES/WARNINGS/ADVISORIES... 359 AM CDT THU AUG 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
400 AM CDT THU AUG 2 2012 .SHORT TERM...TODAY THROUGH SATURDAY NIGHT 359 AM CDT THU AUG 2 2012 AT 3 AM...THE CLUSTER OF SHOWERS AND THUNDERSTORMS...THAT MOVED NORTH OF THE INTERSTATE 90 CORRIDOR FROM LAST EVENING INTO THE EARLY OVERNIGHT...WAS LOCATED ACROSS EAST-CENTRAL AND NORTHEAST WISCONSIN. THIS WAS ASSOCIATED WITH A 700 TO 500 MB TROUGH. THE 02.00Z MODELS ARE IN GOOD AGREEMENT THAT THIS SYSTEM WILL CONTINUE TO MOVE EAST AWAY FROM THE REGION THIS MORNING. FURTHER TO THE SOUTHWEST ANOTHER SHORT WAVE TROUGH WAS AIDING IN THE DEVELOPMENT OF A MESOSCALE CONVECTIVE COMPLEX ACROSS EASTERN NEBRASKA AND NORTHERN KANSAS. THIS SYSTEM IS FORECAST TO CONTINUE TO MOVE EAST ACROSS SOUTHERN IOWA AND MISSOURI THIS MORNING...AND SOUTHERN ILLINOIS THIS AFTERNOON. IN BETWEEN THESE TWO WAVES...THERE IS A WEAK COLD FRONT EXTENDING FROM MENOMINEE TO CHARLES CITY IOWA. THE LATEST RAP CONTINUES TO SHOW THAT THE 900 TO 600 MB FRONTOGENESIS WILL SLOWLY WEAKEN THIS MORNING. THIS FRONTOGENESIS ALONG WITH WEAK MOISTURE CONVERGENCE WILL AID IN THE IN THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS MORNING. A 700 MB SPEED MAXIMUM MOVING THROUGH THE REGION EARLY THIS MORNING IS HELPING TO ENHANCE THE 0-3 KM SHEAR INTO THE 35 TO 40 KNOT RANGE. AS A RESULT...THERE IS A POSSIBILITY THAT WE COULD HAVE A FEW THUNDERSTORMS BECOME SEVERE THROUGH 9 AM THIS MORNING. THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. FOR THIS AFTERNOON...THE WINDS ARE GENERALLY PARALLEL WITH THE FRONT. AS A RESULT...THERE IS LITTLE MOISTURE CONVERGENCE ALONG THIS BOUNDARY. AS A RESULT...NOT SOLD ON THE IDEA THAT WE WILL SEE THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THE NMM AND ARW ALSO SUPPORT THIS TOO. FROM FRIDAY NIGHT INTO SATURDAY NIGHT...THE MODELS ARE TRENDING SLOWER WITH THE COLD FRONTAL PASSAGE THROUGH THE FORECAST AREA. THE NAM/WRF IS THE FASTEST AND IT SHOWS THE FRONT THROUGH MUCH OF THE AREA BY NOON SATURDAY. MEANWHILE THE ECMWF AND GFS WOULD SUGGEST THAT THE COLD FRONT WILL MOVE INTO NORTHEAST IOWA AND SOUTHEAST MINNESOTA ON SATURDAY MORNING...AND THEN MOVE EAST THROUGH THE REMAINDER OF THE AREA EARLY SATURDAY AFTERNOON. DUE TO THIS SLOWER FRONTAL MOVEMENT...DELAYED THE PRECIPITATION CHANCES BY ABOUT 12 TO 18 HOURS. THE 0-3 KM ML CAPES AHEAD OF THIS FRONT CLIMB INTO THE 2 TO 3K RANGE. MEANWHILE THE BEST SHEAR IS LOCATED EITHER ON THE FRONT OR POST FRONTAL. AS RESULT...WILL HAVE TO WATCH FOR THE POTENTIAL OF A FEW THUNDERSTORMS BECOMING SUPERCELLS ALONG THE FRONT. AT THIS TIME...THE BEST CHANCE LOOKS TO BE ACROSS SOUTHERN AND EASTERN WISCONSIN. THIS IS DUE TO THESE AREAS HAVING A LONGER TIME TO BUILD UP INSTABILITY PRIOR TO THE FRONTAL PASSAGE. .LONG TERM...SUNDAY THROUGH THURSDAY 359 AM CDT THU AUG 2 2012 ON SUNDAY...A COLD POOL WILL MOVE EAST ACROSS NORTHEAST MINNESOTA AND NORTHERN WISCONSIN. THERE WILL BE LIKELY SOME SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH IT...BUT LIKE THE PAST COUPLE OF DAYS IT LOOKS LIKE THEY WILL BE NORTH OF THE FORECAST AREA. FROM SUNDAY NIGHT INTO TUESDAY...HIGH PRESSURE WILL PROVIDE DRY WEATHER AND SLIGHTLY ABOVE-NORMAL TEMPERATURES. BEYOND THIS TIME FRAME...THE GFS AND ECMWF DIFFER ON WHETHER ANOTHER CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE REGION. WITH THESE DIFFERENCES JUST KEPT THE SLIGHT CHANCES THAT WERE PRODUCED IN THE ALL BLEND. && .AVIATION... 1115 PM CDT WED AUG 1 2012 A WEST-EAST RUNNING FRONTAL BOUNDARY WILL CONTINUE TO SERVE AS THE FOCUS FOR SHRA/TS DEVELOPMENT OVERNIGHT...PERSISTING INTO THU MORNING. THERE IS STILL A SMALL THREAT FOR STRONG TO DAMAGING WIND GUSTS IN THE VICINITY OF ANY STORM THROUGH ABOUT 2 AM...BUT MOSTLY THIS POTENTIAL HAS LESSENED AS THE NEAR SFC STABILITY HAS INCREASED. DO EXPECT PERIODS OF SHRA/TS OVERNIGHT. THE SEVERAL HOURS OF RAIN COULD RESULT IN THE LOWERING OF CLOUD BASES...BUT WILL KEEP TAFS VFR FOR NOW. EXPECT THE RAIN TO EXIT EAST BY THE AFTERNOON. SHOULD BREAK OUT OF BKN MID LEVEL CIGS BY MID/LATE AFTERNOON. FOR WINDS... DIRECTION COULD BE HIGHLY VARIABLE AND RELATIVELY LIGHT AS THE FRONT LAYS ACROSS KRST/KLSE. THIS MAKES PINNING DOWN A PREVAILING DIRECTION A BIT DIFFICULT UNTIL THE FRONT SAGS SOUTH LATER THU AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... 359 AM CDT THU AUG 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1150 PM CDT WED AUG 1 2012 .AVIATION/06Z TAFS/... OUTFLOW DRIVEN THUNDERSTORMS NORTH OF LA CROSSE EXPECTED TO WEAKEN AS THEY MOVE EAST...AND WILL REMAIN WELL NORTH OF TAF SITES OVERNIGHT. CHANCE OF THUNDER THURSDAY AFTERNOON ON NOSE OF 850 WARM AIR ADVECTION AND FRONTOGENETIC FORCING WITH WEAK COLD FRONT...BUT VERY DRY BELOW 10K FT SO CONFIDENCE LOW. WILL MENTION VCNTY FOR NOW. BOUNDARY LAYER IS STILL STIRRED SO NO FOG FORECAST BUT NEEDS TO BE WATCHED ESPECIALLY AT KENW. OTHERWISE VFR CONDITIONS EXPECTED THROUGH FORECAST PERIOD. && .PREV DISCUSSION... /ISSUED 325 PM CDT WED AUG 1 2012/ VERY SHORT TERM...TONIGHT AND THURSDAY. CURRENT ELEVATED CONVECTION ACROSS NORTHERN WISCONSIN ASSOCIATED WITH LOW LEVEL WARM AIR ADVECTION AND NOSE OF 30 KNOT PLUS WESTERLY LOW LEVEL JET. THIS CONVECTION SHOULD SHIFT SOUTHEAST TOWARD CENTRAL TO EAST CENTRAL WISCONSIN BUT WEAKEN...AS CAPPED AIRMASS LINGERS IN SOUTHERN WISCONSIN. THIS IS SUPPORTED BY 16Z RUN OF HRRR MODEL. MAY SEE SOME LEFTOVER DEBRIS CLOUDS MOVE THROUGH THE AREA LATER THIS AFTERNOON INTO THE EARLY EVENING. WILL GO DRY FOR NOW IN THE FAR NORTHERN COUNTIES THROUGH THE REST OF THE DAY. SURFACE COLD FRONT SHIFTS SOUTHEAST TOWARD THE AREA TONIGHT...THEN SLOWLY SOUTHWARD THROUGH THE AREA ON THURSDAY. WARM AIR ADVECTION CONTINUES AHEAD OF THE FRONT TONIGHT...WITH THE RIGHT REAR QUADRANT OF A 250MB JET STREAK PUSHING THROUGH LATER TONIGHT INTO THURSDAY MORNING. AREA FORECAST SOUNDINGS FROM NAM AND RAP SHOWING CAP FOR SURFACE BASED PARCELS TONIGHT AND THURSDAY...WITH MODEST ELEVATED CAPES AROUND 500 J/KG. LOW LEVELS REMAIN DRY...WITH SOME MID LEVEL MOISTURE MOVING INTO THE AREA LATER TONIGHT INTO THURSDAY. HRRR MODEL TRIES TO DEVELOP AN AREA OF CONVECTION IN SOUTHERN MINNESOTA ALONG COLD FRONT AND BRING IT TOWARD THE WESTERN COUNTIES AFTER MIDNIGHT TONIGHT. FOR NOW...WILL BRING IN CHANCE POPS FROM NORTHWEST TO SOUTHEAST TONIGHT. LINGERED CHANCE POPS THURSDAY MORNING IN THE NORTHERN COUNTIES...LOWER TO THE SOUTH...WITH LOWER END POPS DURING THE AFTERNOON. TEMPERATURES WILL BE TRICKY DEPENDING ON HOW MUCH MID LEVEL CLOUDINESS DEVELOPS/MOVES THROUGH THE AREA. WENT SOMEWHAT LOWER THAN WARM 925MB TEMPERATURES FROM NAM...UPPER 60S TONIGHT WITH UPPER 80S TO LOWER 90S THURSDAY. LAKE BREEZE IN THE AFTERNOON SHORT TERM...THURSDAY NIGHT THROUGH SATURDAY. WEAK Q-VECTOR CONVERGENCE AND FRONTEGENETICAL FORCING MAY RESULT IN A FEW SHOWERS OR THUNDERSTORMS LINGERING INTO THURSDAY EVENING OVER THE NORTHERN AREAS. BOTH ECMWF AND NAM SHOW THIS WEAK FORCING...BUT WILL BE LIMITED BY DRYING MID LEVELS. SLIGHTLY BETTER FORCING FARTHER NORTH...SO WL ONLY GO WITH SCHC POPS FOR NOW. LOW LEVEL MIXING SHOULD PREVENT SIGNIFICANT FOG LATER THURSDAY NIGHT. SHORT WAVE RIDGING AHEAD OF NEXT WEATHER SYSTEM IS EXPECTED TO BRING A PLEASANT DAY FOR FRIDAY...WITH UNSETTLED CONDITIONS FOCUSED TO THE SOUTH AND WEST OF WI. SHORT TERM GUIDANCE IN SURPRISINGLY GOOD AGREEMENT ON MORE VIGOROUS SHORT WAVE TROF MOVING ACROSS SOUTHERN CANADA AND THE WESTERN GTLAKES FRIDAY NIGHT THROUGH SATURDAY NIGHT. ASSOCIATED LOW PRESSURE WILL DRAG A COLD FRONT ACROSS SOUTHERN WI AND LAKE MICHIGAN DURING PEAK HEATING OF THE AFTN AND EVE. WITH SFC DEWPTS LIKELY TO BE IN THE MID 60S TO LOW 70S...SFC BASED CAPE VALUES MAY CLIMB TO ABV 3000 J/KG. BULK SHEAR WILL BE STRONG ENOUGH...IN THE 25 TO 40KT RANGE. LOW LEVEL JETS REMAIN FOCUSED FARTHER SOUTH ALONG WARM FRONT AND NORTH...CLOSER TO LOW PRESSURE. HENCE WL KEEP POPS IN HIGH CHANCE CATEGORY INTO SAT NGT...AND MENTION POSSIBILITY OF SEVERE IN HAZARDOUS WEATHER OUTLOOK. LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. VIGOROUS SHORT WAVE TROUGH AND COLD FRONT PUSH EAST OF WISCONSIN SATURDAY NIGHT...USHERING COOLER AND DRY CONDITIONS INTO THE REGION FOR SUNDAY AND MONDAY. GFS ENSEMBLES IN FAIRLY GOOD AGREEMENT ON THIS SCENARIO. EXTENDED OUTLOOK TURNS MORE MURKY HEADING INTO MID-WEEK AS BOTH ECMWF AND GFS HAVE BEEN FLIP-FLOPPING ON UPPER LEVEL STEERING FLOW. LATEST SOLUTIONS HAVE TRENDED TOWARD MORE PROGRESSIVE WEST-NORTHWEST STEERING FLOW FOR THE LATER HALF OF THE PERIOD. UKMT...GFS AND ECMWF SOLUTIONS CARRY WEAK FRONTAL BOUNDARY THROUGH WI SOMETIME IN THE MON NGT/TUESDAY TIME FRAME...WITH FRONT POSSIBLY BECOMING STATIONARY ACROSS THE REGION...BUT CONFIDENCE LOW AS EXTENDED GUIDANCE HAVING ISSUES WITH TIMING AND STRENGTH OF SHORT WAVE TROFFING MOVING INTO WESTERN CONUS. AFTER COOLER...MORE SEASONAL PERIOD ON SUNDAY AND MONDAY...85H TEMPS WARM BACK TO AROUND 20C. GFS 5DAY ANOMOLIES SHOW RIDGING AND WARMER TEMPERATURES EXPANDING BACK INTO THE UPPER MIDWEST LATER NEXT WEEK AHEAD OF LONG WAVE TROUGH AMPLIFICATION IN THE EASTERN PAC/NORTHWEST CONUS. AVIATION /00Z TAFS/...VFR CONDITIONS EXPECTED THROUGH THURSDAY ACROSS TAF SITES. FEW TO SCATTERED DIURNAL CUMULUS AT EASTERN TAF SITES SHOULD DISSIPATE BY SUNSET. LIGHT SOUTH TO SOUTHWEST WINDS EXPECTED AT MADISON DURING THIS TIME...WITH LIGHT SOUTHEAST WINDS EVENTUALLY REACHING MILWAUKEE AND KENOSHA BY 22Z TO 23Z WEDNESDAY. SOME MID LEVEL CLOUDS FROM STORMS TO THE NORTH MAY SHIFT THROUGH TAF SITES LATE THIS AFTERNOON AND EARLY THIS EVENING. SCATTERED TO BROKEN MIDDLE TO HIGH CLOUDS SHOULD GRADUALLY MOVE INTO THE AREA LATER TONIGHT AND THURSDAY. COLD FRONT WILL SHIFT SOUTHEAST TOWARD TAF SITES LATE TONIGHT...THEN SLIDES SOUTHWARD THROUGH TAF SITES THURSDAY. MAY SEE SHOWERS AND STORMS APPROACH MADISON BETWEEN 06Z AND 12Z THURSDAY...AND ACROSS ALL SITES THURSDAY. HOWEVER...WILL HOLD OFF MENTION IN TAFS FOR NOW DUE TO LOW CONFIDENCE IN AREAL COVERAGE AND TIMING. LIGHT WINDS WILL SHIFT TO THE NORTHEAST/EAST IN THE WAKE OF THE COLD FRONT IN THE LATE MORNING AND EARLY AFTERNOON THURSDAY. CONFIDENCE... TONIGHT AND THURSDAY...MEDIUM THURSDAY NIGHT...LOW TO MEDIUM. FRIDAY AND FRIDAY NIGHT...MEDIUM. SATURDAY AND SATURDAY NIGHT...MEDIUM. SUNDAY AND MONDAY...MEDIUM TO HIGH. TUESDAY AND WEDNESDAY...LOW. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...REM TONIGHT/THURSDAY AND AVIATION/MARINE...WOOD THURSDAY NIGHT THROUGH WEDNESDAY...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1115 PM CDT WED AUG 1 2012 .SHORT TERM...TONIGHT 615 PM CDT WED AUG 1 2012 WATCHING EVOLUTION OF THUNDERSTORMS ASSOCIATED WITH ELEVATED INSTABILITY AND SFC FRONT/ELEVATED FRONTOGENETIC FORCING ACROSS SOUTHWEST MN. THIS WEST-EAST RUNNING BOUNDARY WILL HOVER ACROSS SOUTHEAST MN-WESTERN WI OVERNIGHT...STAYING A FOCUS FOR SHOWER/STORM DEVELOPMENT. MAIN CONCERN THOUGH IS THE SEVERE POTENTIAL THIS EVENING. STRONG INSTABILITY WITH MLCAPES NEAR 4K J/KG OVER SOUTHERN MN PER RAP ANALYSIS AT 22Z. SHEAR ISN/T TOO IMPRESSIVE...BUT ABOUT 20-25 KTS EFFECTIVE SHEAR. THE INSTABILITY WOULD SUPPORT STRONG UPDRAFTS AND A LARGE HAIL THREAT. PERHAPS MORE SIGNIFICANTLY IS THE DEEP DRY SUB CLOUD LAYER. BUFKIT SOUNDINGS CONTINUE TO INDICATE THIS...WITH DCAPES OVER 1500 J/KG PROGGED FOR THE FORECAST AREA THIS EVENING. THIS ENHANCES THE DAMAGING WIND THREAT. ANY STRONG STORM WOULD BE CAPABLE OF PRODUCING 40 MPH GUSTS...OBVIOUSLY MORE WITH A SEVERE STORM. SEVERE THUNDERSTORM WATCH BUTTING UP AGAINST THE WESTERN FORECAST AREA...AND IF STORMS CONTINUE TO EVOLVE...WOULD EXPECT ANOTHER WATCH FOR SOUTHEAST MN INTO WESTERN WISCONSIN BY MID EVENING. .LONG TERM...SUNDAY THROUGH WEDNESDAY 309 PM CDT WED AUG 1 2012 MEDIUM RANGE MODEL RUNS OF 01.00Z IN RATHER GOOD AGREEMENT WITH THE TROUGH MOVING EAST OF THE REGION AND WEAK SHORTWAVE RIDGING BUILDING INTO THE UPPER MIDWEST. MODELS STAY IN PRETTY GOOD AGREEMENT MON-WED AS THE SHORTWAVE RIDGING QUICKLY MOVES EAST OF THE AREA MON AND THE NEXT AND THE NEXT STRONGER TROUGH MOVES ACROSS SOUTHERN CAN/NORTHERN CONUS...INTO THE UPPER MIDWEST TUE/WED. SOME DIFFERENCE OF TIMING/ STRENGTH DETAILS OF SHORTWAVES IN THE FLOW BY TUE/WED BUT THIS TO BE EXPECTED. BETWEEN MODEL CONSISTENCY GOOD BUT RUN-TO-RUN CONSISTENCY LESS THAN DESIRABLE...ESPECIALLY BY TUE/WED. LONG-TERM FCST CONFIDENCE GOOD SUN THEN AVERAGE MON-WED UNTIL THE DETAIL CONSENSUS IMPROVES. WITH THE TROUGH/LOW EXITING EAST...DRIER/COOLER CAN HIGH PRESSURE SETTLES ACROSS THE REGION FOR SUN/MON. TEMPS LOOKING TO BE BELOW NORMAL SUN...THEN ALREADY MODERATE ON MON AS THE CENTER OF THE HIGH MOVES EAST AND SOUTHERLY FLOW RETURNS. MID LEVEL TROUGH MOVING EAST ALONG THE US/CAN BORDER TUE/WED DRAGS A SFC TROUGH/FRONT INTO/ ACROSS THE AREA TUE. AGAIN TIMING/DETAIL DIFFERENCES ON MOISTURE/ INSTABILITY AND FORCING/LIFT BY TUE. BOUNDARY LOOKS TO STALL IN THE REGION WED WITH STRENGTHENING LOW PRESSURE IN THE CENTRAL/NORTHERN PLAINS AS MORE SHORTWAVE ENERGY COMES THRU THE ROCKIES OR DROPS INTO THE NORTHERN PLAINS. SMALL SHRA/TSRA CHANCES TUE/WED LOOK REASONABLE AT THIS POINT. WITH CONTINUED SOUTHERLY/INCREASING MOISTURE...TEMPS CLIMB BACK TO ABOVE NORMAL FOR TUE/WED. MODEL CONSENSUS DATA SET IN FCST GRIDS FOR DAYS 4-7 HAVE THIS WELL TRENDED. && .AVIATION... 1115 PM CDT WED AUG 1 2012 A WEST-EAST RUNNING FRONTAL BOUNDARY WILL CONTINUE TO SERVE AS THE FOCUS FOR SHRA/TS DEVELOPMENT OVERNIGHT...PERSISTING INTO THU MORNING. THERE IS STILL A SMALL THREAT FOR STRONG TO DAMAGING WIND GUSTS IN THE VICINITY OF ANY STORM THROUGH ABOUT 2 AM...BUT MOSTLY THIS POTENTIAL HAS LESSENED AS THE NEAR SFC STABILITY HAS INCREASED. DO EXPECT PERIODS OF SHRA/TS OVERNIGHT. THE SEVERAL HOURS OF RAIN COULD RESULT IN THE LOWERING OF CLOUD BASES...BUT WILL KEEP TAFS VFR FOR NOW. EXPECT THE RAIN TO EXIT EAST BY THE AFTERNOON. SHOULD BREAK OUT OF BKN MID LEVEL CIGS BY MID/LATE AFTERNOON. FOR WINDS... DIRECTION COULD BE HIGHLY VARIABLE AND RELATIVELY LIGHT AS THE FRONT LAYS ACROSS KRST/KLSE. THIS MAKES PINNING DOWN A PREVAILING DIRECTION A BIT DIFFICULT UNTIL THE FRONT SAGS SOUTH LATER THU AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... 309 PM CDT WED AUG 1 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RIECK LONG TERM....RRS AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MIAMI FL
358 AM EDT SAT AUG 4 2012 ...LOCALLY HEAVY RAINFALL POSSIBLE TODAY... ...MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES... .DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH? A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO 50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS), DURATION AND AMOUNT IS OF HIGH UNCERTAINTY. AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT NIGHT. THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL YESTERDAY. TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI. && .MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE NEEDED AT THIS TIME. && .FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN TYPICALLY HIGH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 78 89 79 / 70 50 60 50 FORT LAUDERDALE 88 80 89 79 / 70 50 60 50 MIAMI 89 78 89 79 / 70 50 60 50 NAPLES 91 76 92 77 / 50 30 50 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...57/GREGORIA AVIATION/RADAR...15/JR
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
143 AM EDT SAT AUG 4 2012 .PREV DISCUSSION... /ISSUED 1013 PM EDT FRI AUG 3 2012/ UPDATE... SCATTERED TO ISOLATED THUNDERSTORM DEVELOPMENT HAS BEEN PERSISTENT OVER PORTIONS OF CENTRAL AND EASTERN GA WITH LITTLE TO NO ACTIVITY ACROSS THE NW PORTION. THE RECENT HRRR RUNS HAVE BEEN PICKING UP BETTER ON THE CONVECTION AND MAINTAINS THE DEVELOPMENT WELL INTO THE OVERNIGHT. HAVE ADJUSTED TO HAVE CHANCE POPS IN THESE AREAS THROUGH THE OVERNIGHT WHILE DECREASING THE NW AND SE PORTIONS TO SLIGHT CHANCES FROM 06-12Z. ALL ELSE SEEMS TO BE ON TRACK. PREVIOUS DISCUSSION FOLLOWS... 03 PREV DISCUSSION... /ISSUED 303 PM EDT FRI AUG 3 2012/ SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... CURRENT RADAR LOOP SHOWS SHOWERS MOVING INTO THE AREA FROM THE NW. ISOLATED THUNDERSTORMS SHOULD START MOVING INTO THE AREA AS SOON AS THINGS DESTABILIZE A BIT MORE THIS AFTERNOON. THE BIGGEST THREAT STILL APPEARS TO BE ISOLATED AREAS OF FLOODING AS PW VALUES ARE IN THE 2 TO 2.20 INCH RANGE THROUGH 00Z SUN. CAPES ARE IN THE 1500 TO 2000 J/KG RANGE WITH LIS NEAR -3 TO -4 THIS AFTERNOON. THE INSTABILITIES DROP OFF VERY QUICKLY AFTER SUNSET BUT THE PWS CONTINUE TO STAY UP. THE SHORTWAVE MOVING SE OUT OF MIDDLE TN WILL PUSH INTO NW GA LATTER TONIGHT AND STALL ACROSS N AND W GA THROUGH 00Z SUN. IT WILL STAY THERE BEFORE BEGINNING TO MAKE ITS WAY BACK NORTHWARD AS THE BERMUDA LIKE RIDGE BEGINS TO BUILD IN FROM THE ATLANTIC SAT/SUN. WILL CONTINUE WITH LIKELY POPS THIS AFTERNOON AND TONIGHT WITH CHANCE POPS SAT/SAT NIGHT. TEMPS WILL STAY NEAR OR SLIGHTLY BELOW SEASONAL NORMS DUE TO THE PRECIP AND CLOUD COVER EXPECTED. 01 LONG TERM /SUNDAY THROUGH FRIDAY/... DESPITE SLIGHT TIMING DIFFERENCES...MODELS ARE STILL IN FAIRLY GOOD AGREEMENT WITH A COLD FRONT MOVING INTO NORTH GEORGIA ON MONDAY AND SINKING INTO CENTRAL GEORGIA ON TUESDAY. BASED ON CONSISTENCY OF MODELS WITH AFFECTS FROM FRONT EXPECTED ACROSS THE CWA MONDAY AND TUESDAY...HAVE INCREASED POPS CLOSER TO THE HIGHER END OF CHANCE. DIFFERENCES IN GFS AND ECMWF BECOME MORE APPARENT INTO MIDWEEK. 12Z GFS WANTS TO LINGER THE FRONT ACROSS THE CWA THROUGH THE LONG TERM WHILE THE 00Z ECMWF SLIDES THE BOUNDARY SOUTH OF THE AREA. WITH IT BEING SUMMER HAVE TRENDED TOWARD LOW END CHANCE POPS...CLOSER TO THE GFS SOLUTION. WITH LINGERING BOUNDARY SUGGESTED THOUGH BY THE GFS...POPS MAY BE A LITTLE ON THE LOW SIDE. 11 && .AVIATION... 06Z UPDATE... CONVECTION IN EASTERN ZONES WILL CONTINUE TO WEAKEN THROUGH THE EARLY MORNING. EXPECT THAT MOST SITES WILL SEE IFR CIGS...POSSIBLY LIFR...AROUND 12Z. CIGS WILL LIFT THROUGH MID-MORNING. EXPECT A SIMILAR CONVECTIVE PATTERN TO FRIDAY...WITH PEAK ACTIVITY AROUND 00Z. WINDS GENERALLY SOUTHEAST THROUGH THE PERIOD...LIGHT OVERNIGHT AND BETWEEN 5-10KT DURING THE DAY EXCEPT IN THUNDERSTORMS. //ATL CONFIDENCE...06Z UPDATE... MEDIUM ON MOST ELEMENTS...INCLUDING TIMING OF CONVECTION AND DEVELOPMENT OF IFR CIGS. LOW ON POTENTIAL LIFR CIG DEVELOPMENT. TDP && .PRELIMINARY POINT TEMPS/POPS... ATHENS 87 70 89 72 / 60 60 30 20 ATLANTA 89 72 91 74 / 60 60 30 20 BLAIRSVILLE 80 69 85 68 / 60 60 40 30 CARTERSVILLE 88 71 90 69 / 60 50 40 30 COLUMBUS 90 72 91 74 / 50 50 40 20 GAINESVILLE 85 71 87 72 / 60 60 30 30 MACON 93 72 91 73 / 40 40 40 20 ROME 88 71 90 71 / 50 50 40 30 PEACHTREE CITY 88 69 89 70 / 60 60 30 20 VIDALIA 93 74 92 75 / 30 30 40 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1208 AM CDT SAT AUG 4 2012 .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... FOCUS THROUGHOUT THE SHORT/MID RANGE WILL BE ON SYSTEM MOVING THROUGH THE REGION TONIGHT THROUGH SATURDAY NIGHT...AND ASSOCIATED COLD FRONT DROPPING THROUGH THE STATE. INITIALLY LINGERING ACTIVITY FROM EARLIER TODAY TO THE NORTHWEST HAS JUST DIMINISHED IN THE PAST FEW HOURS ACROSS NORTHWEST IOWA ASSOCIATED WITH SOME WEAK ENERGY ALOFT PUSHING OUT AHEAD OF THE MAIN WAVE. HRRR ADVERTISES SOME REDEVELOPMENT ACROSS THE NORTH CENTRAL CWA WITH THIS ENERGY...AND HAVE A FEW WEAK CELLS POPPING JUST TO THE NE OF THE CWA. ALSO HAVE DECENT CU FIELD EXTENDING BACK INTO THE CWA...WITH ANOTHER CU FIELD SITUATED ACROSS THE EXTREME SOUTHERN CWA NORTH OF ONGOING MCS THAT HAS BEEN IN PLACE ACROSS MO ALL DAY. THEREFORE HAVE SOME SLIGHT CHANCE POPS IN THE NORTH AND SOUTH THROUGH THE REMAINDER OF THE AFTERNOON HOURS WITH SPC MESODATA SUGGESTING SUFFICIENT INSTABILITY IN PLACE AND DECENT SHEAR ACROSS THE NORTH. THEREFORE AN ISOLATED SEVERE STORM CANNOT BE RULED EITHER ACROSS THE NORTH WITH ANY ACTIVITY THAT MAY DEVELOP. OTHERWISE GREATER CHANCE FOR PRECIPITATION/CONVECTION LATER TONIGHT AS STORMS CONTINUE TO DEVELOP IN VICINITY OF THE SFC FRONT SITUATED ACROSS CENTRAL SD INTO CENTRAL NE. AS THE MAIN UPPER WAVE PUSHES EAST ACROSS THE DAKOTAS AND INTO MINNESOTA SATURDAY...ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE STATE...WITH SHOWERS AND THUNDERSTORMS EXPECTED TO BE ONGOING ACROSS THE NORTHWESTERN CWA SATURDAY MORNING AND CONTINUING TO TRACK EASTWARD SLOWLY DIMINISHING WITH TIME. FRONT WILL THEN PUSH INTO THE EASTERN CWA IN THE AFTERNOON HOURS...WITH REDEVELOPMENT EXPECTED BY LATE AFTERNOON ALONG THE FRONT...WITH THE FRONT EXITING THE CWA BY EARLY TO LATE EVENING AS THE UPPER SYSTEM TRACKS INTO THE GREAT LAKES REGION. THEREFORE HAVE GREATEST POPS FOR SATURDAY ACROSS THE CWA...WITH BEST CHANCE OF WIDER SPREAD PRECIPITATION AS THE AREA HAS SEEN IN A FEW WEEKS. MUCH COOLER AIR MOVING IN BEHIND THE FRONT...WITH H85 TEMPS DROPPING INTO THE LOWER TEENS TO MID TEENS CELSIUS ALOFT. THEREFORE MAX TEMPS TO BE COOLER IN AREAS BEHIND THE FRONT SATURDAY...WITH MANY SITES NOT MAKING IT OUT OF THE 70S ACROSS NORTHWESTERN IOWA AND MUCH COOLER CONDITIONS ACROSS THE ENTIRE STATE FOR SUNDAY. HIGHS SUNDAY EXPECTED TO TOP OUT IN THE 70S NORTH TO MID 80S SOUTH...WITH A QUICK CHANGE TO RETURN FLOW MONDAY AND MID 80S TO 90S WITH DRY CONDITIONS SUNDAY INTO MONDAY. ANOTHER WEAK SHORTWAVE DROPS DOWN THROUGH THE REGION MONDAY NIGHT IN NORTHWEST FLOW PATTERN ALOFT. THEREFORE COULD SEE A CHANCE FOR SOME NOCTURNAL THUNDERSTORMS MONDAY NIGHT ACROSS MUCH OF THE CWA. .LONG TERM /TUESDAY THROUGH FRIDAY/... BOTH GFS AND EURO NOW INDICATE BROAD NORTHWEST FLOW INTO NEXT WEEK AS UPPER RIDGING RETROGRADES INTO THE ROCKIES. THIS SHOULD DO A COUPLE OF THIS FOR IOWA...FIRST TEMPERATURES WILL LIKELY REMAIN COOLER DURING THE NEXT WEEK THAN WHAT PREVIOUS FORECASTS HAD GOING. READINGS ARE EXPECTED TO BE CLOSE TO NORMAL OR SLIGHTLY ABOVE BUT NOT THE 10 TO 15 DEGREE DEPARTURES WE SAW DURING MUCH OF JULY. SECOND...THE THREAT OF PRECIPITATION SHOULD BE GREATER AS WEAK SHORTWAVES IN THE FLOW DROP INTO THE MIDWEST. THE MAIN PROBLEM WITH THESE IS MORE OF A TIMING ISSUE AS IS OFTEN TYPICAL IN NORTHWEST FLOW. THESE CONDITIONS WILL CERTAINLY PROVIDE SOME RELIEF FROM THE INTENSIFYING DROUGHT WITH BOTH MODELS INDICATING THE NORTHWEST FLOW CONTINUING BEYOND THE FORECAST PERIOD. && .AVIATION...04/06Z CDFNT ENTERING NWRN IA WILL MOVE TO NEAR CENTRAL IA BY SHORTLY AFTER SUNRISE...AND PASS SOUTHEAST OF THE TAF SITES BY EARLY SAT AFTERNOON. LOW PRESSURE WAVE WILL TRAVEL NORTHEAST ALONG THE FRONT. SCATTERED TSRA WILL ACCOMPANY THE FRONT AND ALSO WILL DEVELOP NORTH OF THE FRONTAL BOUNDARY AS THE SURFACE WAVE LIFTS NEWD. HAVE CARRIED A FEW HOURS OF TSRA AROUND THE FRONT AND SHOWERS AFTER THE FRONT. THINKING IS THAT CONDITIONS WILL REMAIN VFR. CLEARING WILL SPREAD SOUTH ACROSS THE STATE LATE SAT AFTERNOON AND EVENING WITH LIGHT NWLY WINDS. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...MS AUG 12 LONG TERM...COGIL AVIATION...MS AUG 12
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
354 AM CDT SAT AUG 4 2012 ...LONG TERM SECTION UPDATED AT 355 AM... .SYNOPSIS... ISSUED AT 1035 PM CDT FRI AUG 3 2012 THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF 90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN. COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE. AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA, THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH 9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA (AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA. TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 245 AM CDT SAT AUG 4 2012 THIS MORNING: SHOWERS AND ISOLATED THUNDERSTORMS ACTIVITY LAST NIGHT WILL CONTINUE TO WEAKEN SIGNIFICANTLY OVERNIGHT. WILL GRADUALLY TAPER POPS THROUGH THIS MORNING BUT KEEP ISOLATED IN THE GRIDS AS A COLD FRONT SLOWLY APPROACHES FROM THE NW. TODAY: MUCH COOLER WEATHER IS EXPECTED TODAY AS A COLD FRONT MOVES ACROSS THE REGION. 850 HPA WINDS ARE FORECAST TO BE IN THE 20-30 KT RANGE SO DON`T THINK SURFACE WINDS WILL BE AT WIND ADVISORY CRITERIA FOR A LONG PERIOD OF TIME. THERE COULD BE SOME ISALLOBARIC FORCING IMMEDIATELY ALONG AND BEHIND THE FRONT SO WINDS MAY REACH CRITERIA JUST FOR A SHORT AMOUNT OF TIME. DID USE THE MIXED LAYER WIND TOOL AND WILL HIGHLIGHT SUB WIND ADVISORY CRITERIA IN THE HWO (MAINLY 20 TO 30 MPH). FORECAST SOUNDINGS SHOW QUITE A BIT OF MID TO UPPER LEVEL (500-300 HPA) MOISTURE SO WILL KEEP LINGERING CLOUD COVER IN THE GRIDS (PARTICULARLY FOR THE FIRST HALF OF TODAY). USED MOSGUIDANCEBC AFTER CHECKING BOISE VERIFICATION TO SEE THAT THIS OUTPUT IS PERFORMING BETTER THAN THE NAM. A LARGE TEMPERATURES GRADIENT IS EXPECTED ACROSS THE REGION WITH LOWER 80S DEG F ACROSS WEST CENTRAL KANSAS TO AROUND 100 DEG F ACROSS SOUTH CENTRAL KANSAS. WILL ALSO KEEP SLIGHT POPS GOING TODAY AS THE RIGHT ENTRANCE REGION OF A 250 HPA JET STREAK SAGS SOUTHWARD CLOSER TO SOUTHWEST KANSAS. THIS IN COMBINATION WITH WEAK ISENTROPIC LIFT COULD LEAD TO A FEW SHOWERS AND ISOLATED THUNDERSTORMS TODAY. NOT REALLY IMPRESSED WITH THE THERMODYNAMIC PROFILE IN THE SURFACE TO 700 HPA LAYER AS THIS STRATUM LOOKS FAIRLY DRY SO DON`T THINK WE WILL SEE ANY SIGNIFICANT PRECIPITATION AMOUNTS FOR THE REST OF TODAY. TONIGHT: THE WRF-ARW AND TO A LESSER EXTENT THE NAM ARE INDICATING THE POSSIBILITY OF LATE NIGHT CONVECTION ALONG THE FRONT AFTER 00Z TONIGHT. THE AFOREMENTIONED ENTRANCE REGION WILL BE EVEN CLOSER AND ALSO WITH A STRENGTHENING 850 HPA LOW LEVEL JET MAY PROVIDE ENOUGH DYNAMICS AND LIFT FOR MORE CONVECTION. WILL INCREASE POPS LATE TONIGHT ACROSS SOUTH CENTRAL KANSAS BUT WILL NOT GET CARRIED AWAY AS CONFIDENCE IS FAIRLY LOW AS THE NAM HAS THE FRONT FARTHER SOUTH INTO OKLAHOMA IN WHICH OUR REGION MAY NOT SEE ANY ADDITIONAL PRECIPITATION. LOWS HEADING INTO SUNDAY WILL BE PLEASANT WITH VALUES IN THE 50S AND 60S DEG F. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 353 AM CDT SAT AUG 4 2012 TROPICAL THUNDERSTORMS CONTINUE TO BE VERY ACTIVE NORTH OF THE EQUATOR FROM NEAR 120E TO 170E, AND A TROPICAL CYCLONE IS EVIDENT ON SATELLITE IMAGERY SOUTH OF JAPAN. THE INDIAN OCEAN HAS BEEN FAIRLY QUIET IN RECENT DAYS. IT DOES APPEAR THAT A COHERENT FEATURE IS PROPAGATING RAPIDLY EASTWARD INTO THE WESTERN HEMISPHERE AND WILL REACH THE WESTERN INDIAN OCEAN AGAIN BY MID AUGUST. ATMOSPHERIC RELATIVE ANGULAR MOMENTUM CONTINUES TO BE SLIGHTLY ABOVE CLIMATOLOGICAL VALUES, AND MOUNTAIN TORQUE HAS BECOME POSITIVE RECENTLY. ALTHOUGH THE SIGNAL IS VERY WEAK, THE ATMOSPHERE MAY BE HEADED TOWARD PHASE 5 OF THE WEICKMANN/BERRY GLOBAL WIND OSCILLATION PHASE SPACE DIAGRAM. IF THIS OCCURS, ANTICYCLONIC FLOW WILL BE FAVORED ON THE WESTERN UNITED STATES WITH A TENDENCY TOWARD TROUGHING IN THE EAST BY MID AUGUST. MOST OF THE NUMERICAL MODELS ARE SUGGESTING THIS TREND. THE ECMWF IS MORE AGGRESSIVE IN WEAKENING THE UPPER LEVEL RIDGING IN THE CENTRAL PART OF THE COUNTRY THAN THE GFS, AND MOST OF THE GEM ENSEMBLE MEMBERS MAINTAIN MORE RIDGING THAN THE ECMWF DETERMINISTIC SOLUTION. GIVEN THE HOT, DRY CONDITIONS IN THE CENTRAL AND SOUTHERN PLAINS AND IMPROBABILITY OF WIDESPREAD BENEFICIAL RAINFALL, THE GFS SOLUTION SEEMS MORE REASONABLE. THE UPPER LEVEL ANTICYCLONE CENTERED OVER SOUTHERN OKLAHOMA AND NORTHERN TEXAS WILL WEAKEN AND RETROGRADE TO NEAR 110W BY MONDAY, AND TROUGHING WILL AMPLIFY IN THE EASTERN UNITED STATES. THE PLUME OF SUBTROPICAL MOISTURE EXTENDING FROM WESTERN MEXICO TO THE CENTRAL PLAINS WILL DROP SOUTHWARD TO NEAR THE KANSAS/OKLAHOMA BORDER BY SUNDAY MORNING, AND A FEW HIGH BASED SHOWERS MAY BE IN PROGRESS UNDER THE TROPICAL PLUME SUNDAY MORNING. A WEAK UPPER LEVEL TROUGH EVIDENT ON SATELLITE IMAGERY IN NORTHERN ARIZONA WILL APPROACH THE CENTRAL PLAINS LATE SATURDAY NIGHT AND MAY ENHANCE SHOWER AND THUNDERSTORMS UNDER THE TROPICAL PLUME ALONG AND NORTH OF THE FRONTAL BOUNDARY IN THE SOUTHERN PLAINS. THE PLUME OF SUBTROPICAL MOISTURE WILL CONTINUE TO DROP SOUTHWARD AS FLOW OVER THE CENTRAL PLAINS BECOMES MORE NORTHWEST ON SUNDAY. THERE IS A MARGINAL CHANCE THAT THUNDERSTORMS IN SOUTHEASTERN COLORADO COULD CLIP THE SOUTHWEST CORNER OF KANSAS AS THEY PROPAGATE SOUTHEAST DURING THE EVENING HOURS SUNDAY, BUT CONFIDENCE IS NOT HIGH ENOUGH TO INTRODUCE POPS YET. TEMPERATURES SUNDAY SHOULD BE NEAR SEASONAL AVERAGES. VERY WARM AIR WILL SPREAD BACK INTO WESTERN KANSAS ON MONDAY AS ANOTHER UPPER LEVEL TROUGH DIGS TOWARD THE GREAT LAKES AND LOW LEVEL FLOW BECOMES MORE SOUTHWEST. TEMPERATURES MONDAY SHOULD RETURN TO NEAR 100 DEGREES ACROSS WESTERN KANSAS. A WEAK UPPER LEVEL TROUGH ROTATING AROUND THE WESTERN UNITED STATES ANTICYCLONE WILL APPROACH THE CENTRAL PLAINS BY TUESDAY MORNING. WEAK SYNOPTIC SCALE LIFTING MAY BE SUFFICIENT TO SUPPORT A FEW THUNDERSTORMS IN CENTRAL KANSAS LATE MONDAY NIGHT INTO EARLY TUESDAY, BUT CONFIDENCE IS NOT HIGH. ANOTHER UPPER LEVEL TROUGH ORIGINATING IN THE TROPICAL PACIFIC WILL MOVE OVER THE UPPER LEVEL RIDGE AND APPROACH KANSAS ON WEDNESDAY, AND THUNDERSTORM CHANCES WILL CONTINUE THROUGH THE DAY WEDNESDAY WITH THE BEST OPPORTUNITY IN CENTRAL AND EASTERN KANSAS. UPPER LEVEL HIGH PRESSURE WILL BUILD BACK INTO KANSAS THURSDAY THROUGH SATURDAY, AND MORE TEMPERATURES IN EXCESS OF 100 DEGREES CAN BE EXPECTED. THE NEXT POSSIBILITY OF RAINFALL WILL BE AROUND 12 AUGUST WHEN ANOTHER UPPER LEVEL TROUGH DIGS INTO THE UPPER MIDWEST AND SUPPORTS PROGRESSION OF A COLD FRONT INTO KANSAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1200 AM CDT SAT AUG 4 2012 TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z. NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH GUSTS OF 30-35 KT. && .PRELIMINARY POINT TEMPS/POPS... DDC 86 62 93 64 / 20 10 0 0 GCK 83 62 92 65 / 20 10 0 0 EHA 84 65 88 68 / 20 10 10 10 LBL 87 65 90 66 / 20 10 10 10 HYS 85 58 93 63 / 20 10 0 0 P28 99 67 95 66 / 20 20 10 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SUGDEN SHORT TERM...SUGDEN LONG TERM...RUTHI AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
245 AM CDT SAT AUG 4 2012 ...UPDATE TO SHORT TERM DISCUSSION... .SYNOPSIS... ISSUED AT 1035 PM CDT FRI AUG 3 2012 THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF 90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN. COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE. AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA, THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH 9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA (AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA. TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 245 AM CDT SAT AUG 4 2012 THIS MORNING: SHOWERS AND ISOLATED THUNDERSTORMS ACTIVITY LAST NIGHT WILL CONTINUE TO WEAKEN SIGNIFICANTLY OVERNIGHT. WILL GRADUALLY TAPER POPS THROUGH THIS MORNING BUT KEEP ISOLATED IN THE GRIDS AS A COLD FRONT SLOWLY APPROACHES FROM THE NW. TODAY: MUCH COOLER WEATHER IS EXPECTED TODAY AS A COLD FRONT MOVES ACROSS THE REGION. 850 HPA WINDS ARE FORECAST TO BE IN THE 20-30 KT RANGE SO DON`T THINK SURFACE WINDS WILL BE AT WIND ADVISORY CRITERIA FOR A LONG PERIOD OF TIME. THERE COULD BE SOME ISALLOBARIC FORCING IMMEDIATELY ALONG AND BEHIND THE FRONT SO WINDS MAY REACH CRITERIA JUST FOR A SHORT AMOUNT OF TIME. DID USE THE MIXED LAYER WIND TOOL AND WILL HIGHLIGHT SUB WIND ADVISORY CRITERIA IN THE HWO (MAINLY 20 TO 30 MPH). FORECAST SOUNDINGS SHOW QUITE A BIT OF MID TO UPPER LEVEL (500-300 HPA) MOISTURE SO WILL KEEP LINGERING CLOUD COVER IN THE GRIDS (PARTICULARLY FOR THE FIRST HALF OF TODAY). USED MOSGUIDANCEBC AFTER CHECKING BOISE VERIFICATION TO SEE THAT THIS OUTPUT IS PERFORMING BETTER THAN THE NAM. A LARGE TEMPERATURES GRADIENT IS EXPECTED ACROSS THE REGION WITH LOWER 80S DEG F ACROSS WEST CENTRAL KANSAS TO AROUND 100 DEG F ACROSS SOUTH CENTRAL KANSAS. WILL ALSO KEEP SLIGHT POPS GOING TODAY AS THE RIGHT ENTRANCE REGION OF A 250 HPA JET STREAK SAGS SOUTHWARD CLOSER TO SOUTHWEST KANSAS. THIS IN COMBINATION WITH WEAK ISENTROPIC LIFT COULD LEAD TO A FEW SHOWERS AND ISOLATED THUNDERSTORMS TODAY. NOT REALLY IMPRESSED WITH THE THERMODYNAMIC PROFILE IN THE SURFACE TO 700 HPA LAYER AS THIS STRATUM LOOKS FAIRLY DRY SO DON`T THINK WE WILL SEE ANY SIGNIFICANT PRECIPITATION AMOUNTS FOR THE REST OF TODAY. TONIGHT: THE WRF-ARW AND TO A LESSER EXTENT THE NAM ARE INDICATING THE POSSIBILITY OF LATE NIGHT CONVECTION ALONG THE FRONT AFTER 00Z TONIGHT. THE AFOREMENTIONED ENTRANCE REGION WILL BE EVEN CLOSER AND ALSO WITH A STRENGTHENING 850 HPA LOW LEVEL JET MAY PROVIDE ENOUGH DYNAMICS AND LIFT FOR MORE CONVECTION. WILL INCREASE POPS LATE TONIGHT ACROSS SOUTH CENTRAL KANSAS BUT WILL NOT GET CARRIED AWAY AS CONFIDENCE IS FAIRLY LOW AS THE NAM HAS THE FRONT FARTHER SOUTH INTO OKLAHOMA IN WHICH OUR REGION MAY NOT SEE ANY ADDITIONAL PRECIPITATION. LOWS HEADING INTO SUNDAY WILL BE PLEASANT WITH VALUES IN THE 50S AND 60S DEG F. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 227 PM CDT FRI AUG 3 2012 ON SATURDAY EVENING THE COLD FRONT IS FORECAST TO EXTEND FROM SOUTH CENTRAL KANSAS INTO THE PANHANDLE OF TEXAS. THIS FRONT WILL MOVE A LITTLE FURTHER SOUTH BEFORE BECOMING STATIONARY BY EARLY SUNDAY MORNING. A WEDGE OF HIGHER DEWPOINTS WILL BE LOCATED JUST NORTH OF THIS FRONT ALONG WITH IMPROVING 850-700MB FRONTOGENESIS. UPPER LEVEL JET DYNAMICS ALONG WITH THE TIMING OF THE 500MB TROUGH SUGGESTS THE BETTER UPPER FORCING WILL BE LOCATED NEAR SOUTH CENTRAL KANSAS. FURTHER WEST WEAKER LIFT WILL BE PRESENT, HOWEVER BETTER LOW LEVEL MOISTURE AND UPSLOPE FLOW IS EXPECTED LATE DAY. GIVEN THE BETTER LIFT AND INSTABILITY ACROSS SOUTH CENTRAL KANSAS EARLY SUNDAY EVENING WILL FOCUS THE HIGHER CHANCES OF PRECIPITATION HERE WHILE LOWER CHANCES FURTHER WEST AND NORTHWEST. ON SUNDAY AN UPPER LEVEL RIDGE WILL BUILD INTO THE ROCKIES AS AN AREA OF HIGH PRESSURE AT THE SURFACE MOVES SOUTHEAST ACROSS THE CENTRAL PLAINS. SKIES ARE EXPECTED TO BE MOSTLY SUNNY WITH 850MB TEMPERATURES AT 00Z MONDAY RANGING FROM THE LOW TO MID 20S. MIXDOWN TEMPERATURES FROM THE NAM, MEAN SREF, AND ECMWF CONTINUE TO SUGGEST HIGHS MAINLY IN THE LOW TO MID 90S SO THE PREVIOUS FORECAST STILL LOOKS ON TRACK. ON SUNDAY NIGHT THE SURFACE HIGH WILL MOVE EAST INTO THE MID MISSISSIPPI VALLEY AND 850MB WARM AIR ADVECTION ALONG WITH I310-I315 ISENTROPIC LIFT STARTS TO IMPROVE ACROSS SOUTHWEST KANSAS. MOISTURE MAY BE SOMEWHAT LIMITED, DEPENDING ON WHICH MODEL YOU PREFER. AT THIS TIME GIVEN IMPROVING LIFT WILL INCREASE CLOUD COVER BUT STILL AM LEANING TOWARD HOLDING OFF MENTIONING PRECIPITATION. INCREASING CLOUDS WILL HOWEVER AID IN KEEPING TEMPERATURES UP A FEW DEGREES COMPARED TO WHAT THE LATEST GUIDANCE SUGGESTS. ON MONDAY AND TUESDAY A TROUGH OF LOW PRESSURE WILL DEEPEN ALONG THE LEE OF THE ROCKIES AS 850-700MB TEMPERATURES BEGIN WARM. A 4-6C 24HOUR 850MB TEMPERATURE WARM UP IS FORECAST BY ALL THE MODELS BETWEEN 00Z MONDAY AND 00Z TUESDAY. TEMPERATURES THEN VARY FROM 1 TO 3C BETWEEN 00Z TUESDAY AND 00Z WEDNESDAY. GIVEN THIS TREND SEE LITTLE REASON TO DISAGREE WITH TEMPERATURES NOT REBOUNDING BACK INTO THE MID 90S TO AROUND 100 DEGREES BOTH DAYS. BY MID WEEK THE UPPER LEVEL RIDGE AXIS WILL EXTEND FROM THE FOUR CORNERS REGION INTO SOUTHWEST CANADA. UPPER LEVEL DISTURBANCES WILL ROTATE AROUND THIS UPPER RIDGE AND DOWN THE NORTHWEST FLOW. A WEAK SURFACE BOUNDARY IS FORECAST TO MOVE INTO WESTERN KANSAS TUESDAY NIGHT/WEDNESDAY AND MAY PROVIDE THE FOCUS FOR SOME LATE DAY/OVERNIGHT THUNDERSTORMS AS ANY ONE OF THESE UPPER WAVES MOVE ALONG THE NORTHWEST FLOW AND ACROSS KANSAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1200 AM CDT SAT AUG 4 2012 TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z. NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH GUSTS OF 30-35 KT. && .PRELIMINARY POINT TEMPS/POPS... DDC 86 62 91 70 / 20 10 10 10 GCK 83 62 90 69 / 20 10 10 10 EHA 84 65 90 69 / 20 10 10 10 LBL 87 65 91 70 / 20 10 10 10 HYS 85 58 91 69 / 20 10 0 10 P28 99 67 94 71 / 20 20 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SUGDEN SHORT TERM...SUGDEN LONG TERM...BURGERT AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 AM CDT SAT AUG 4 2012 ...UPDATE TO AVIATION FOR 06Z TAFS... .SYNOPSIS... ISSUED AT 1035 PM CDT FRI AUG 3 2012 THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF 90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN. COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE. AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA, THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH 9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA (AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA. TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 352 PM CDT FRI AUG 3 2012 A NEARLY STATIONARY FRONT EXTENDED FROM SOUTHEAST KANSAS INTO THE TEXAS PANHANDLE THIS AFTERNOON. LOW LEVEL MOISTURE WAS "POOLING" NORTH OF THE FRONT OVER SOUTHWEST KANSAS WITH DEWPOINTS IN THE UPPER 50S TO LOWER 60S, LEADING TO SURFACE BASED CAPE FROM 1000-1500 J/KG. A SHORTWAVE TROUGH WAS PROGRESSING ACROSS THE NORTHERN ROCKIES TODAY AND WILL MOVE ACROSS THE NORTHERN PLAINS ON SUNDAY. THIS FEATURE WILL HELP DRAG A COLD FRONT THROUGH SOUTHWEST KANSAS SATURDAY MORNING. THE WARM FRONT WILL MOVE NORTHWARD TONIGHT INTO SOUTHWEST KANSAS. A FEW THUNDERSTORMS MAY DEVELOP NEAR AND NORTH OF THE WARM FRONT THIS AFTERNOON AND PROPAGATE NORTHWARD AND EASTWARD THIS EVENING INTO KANSAS. ALSO, SURFACE BASED CONVECTIVE INITIATION COULD OCCUR ACROSS SOUTHEAST COLORADO THIS EVENING AND THEN PROGRESS INTO SOUTHWEST KANSAS PER NAM/HRRR. GIVEN THE AFOREMENTIONED CAPE AND INCREASING HIGH LEVEL WINDS TO 40-45KTS, THESE STORMS ARE CAPABLE OF HAIL AS LARGE AS QUARTERS AND WINDS ARE HIGH AS 60 MPH. DECIDED TO CARRY THE HIGHEST POPS IN FAR SOUTHWEST KANSAS THIS EVENING. ADDITIONAL ELEVATED THUNDERSTORMS COULD DEVELOP LATER TONIGHT FURTHER NORTHEAST AND POSSIBLY INTO THE FIRST HALF OF THE DAY SATURDAY. THE PREVIOUS TEMPERATURE FORECAST WAS IN GOOD SHAPE FOR TONIGHT AND FRIDAY. SOME CLOUD COVER SHOULD KEEP TEMPERATURES FROM FALLING TOO MUCH TONIGHT, ALTHOUGH THE WINDS COULD GO LIGHT AROUND 12Z AHEAD OF THE FRONT WHICH WOULD PROMOTE RADIATIONAL COOLING. WINDS SHOULD BE JUST SHY OF ADVISORY CRITERIA FOR FRIDAY BEHIND THE COLD FRONT. TEMPERATURES WILL RISE INTO THE MID TO UPPER 80S FOR MOST OF SOUTHWEST KANSAS, EXCEPT FOR 95 TO 101 IN SOUTH CENTRAL KANSAS INCLUDING BARBER, PRATT AND COMANCHE COUNTIES WHERE THE FRONT WILL NOT ARRIVE UNTIL 2-3 PM. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 227 PM CDT FRI AUG 3 2012 ON SATURDAY EVENING THE COLD FRONT IS FORECAST TO EXTEND FROM SOUTH CENTRAL KANSAS INTO THE PANHANDLE OF TEXAS. THIS FRONT WILL MOVE A LITTLE FURTHER SOUTH BEFORE BECOMING STATIONARY BY EARLY SUNDAY MORNING. A WEDGE OF HIGHER DEWPOINTS WILL BE LOCATED JUST NORTH OF THIS FRONT ALONG WITH IMPROVING 850-700MB FRONTOGENESIS. UPPER LEVEL JET DYNAMICS ALONG WITH THE TIMING OF THE 500MB TROUGH SUGGESTS THE BETTER UPPER FORCING WILL BE LOCATED NEAR SOUTH CENTRAL KANSAS. FURTHER WEST WEAKER LIFT WILL BE PRESENT, HOWEVER BETTER LOW LEVEL MOISTURE AND UPSLOPE FLOW IS EXPECTED LATE DAY. GIVEN THE BETTER LIFT AND INSTABILITY ACROSS SOUTH CENTRAL KANSAS EARLY SUNDAY EVENING WILL FOCUS THE HIGHER CHANCES OF PRECIPITATION HERE WHILE LOWER CHANCES FURTHER WEST AND NORTHWEST. ON SUNDAY AN UPPER LEVEL RIDGE WILL BUILD INTO THE ROCKIES AS AN AREA OF HIGH PRESSURE AT THE SURFACE MOVES SOUTHEAST ACROSS THE CENTRAL PLAINS. SKIES ARE EXPECTED TO BE MOSTLY SUNNY WITH 850MB TEMPERATURES AT 00Z MONDAY RANGING FROM THE LOW TO MID 20S. MIXDOWN TEMPERATURES FROM THE NAM, MEAN SREF, AND ECMWF CONTINUE TO SUGGEST HIGHS MAINLY IN THE LOW TO MID 90S SO THE PREVIOUS FORECAST STILL LOOKS ON TRACK. ON SUNDAY NIGHT THE SURFACE HIGH WILL MOVE EAST INTO THE MID MISSISSIPPI VALLEY AND 850MB WARM AIR ADVECTION ALONG WITH I310-I315 ISENTROPIC LIFT STARTS TO IMPROVE ACROSS SOUTHWEST KANSAS. MOISTURE MAY BE SOMEWHAT LIMITED, DEPENDING ON WHICH MODEL YOU PREFER. AT THIS TIME GIVEN IMPROVING LIFT WILL INCREASE CLOUD COVER BUT STILL AM LEANING TOWARD HOLDING OFF MENTIONING PRECIPITATION. INCREASING CLOUDS WILL HOWEVER AID IN KEEPING TEMPERATURES UP A FEW DEGREES COMPARED TO WHAT THE LATEST GUIDANCE SUGGESTS. ON MONDAY AND TUESDAY A TROUGH OF LOW PRESSURE WILL DEEPEN ALONG THE LEE OF THE ROCKIES AS 850-700MB TEMPERATURES BEGIN WARM. A 4-6C 24HOUR 850MB TEMPERATURE WARM UP IS FORECAST BY ALL THE MODELS BETWEEN 00Z MONDAY AND 00Z TUESDAY. TEMPERATURES THEN VARY FROM 1 TO 3C BETWEEN 00Z TUESDAY AND 00Z WEDNESDAY. GIVEN THIS TREND SEE LITTLE REASON TO DISAGREE WITH TEMPERATURES NOT REBOUNDING BACK INTO THE MID 90S TO AROUND 100 DEGREES BOTH DAYS. BY MID WEEK THE UPPER LEVEL RIDGE AXIS WILL EXTEND FROM THE FOUR CORNERS REGION INTO SOUTHWEST CANADA. UPPER LEVEL DISTURBANCES WILL ROTATE AROUND THIS UPPER RIDGE AND DOWN THE NORTHWEST FLOW. A WEAK SURFACE BOUNDARY IS FORECAST TO MOVE INTO WESTERN KANSAS TUESDAY NIGHT/WEDNESDAY AND MAY PROVIDE THE FOCUS FOR SOME LATE DAY/OVERNIGHT THUNDERSTORMS AS ANY ONE OF THESE UPPER WAVES MOVE ALONG THE NORTHWEST FLOW AND ACROSS KANSAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1200 AM CDT SAT AUG 4 2012 TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z. NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH GUSTS OF 30-35 KT. && .PRELIMINARY POINT TEMPS/POPS... DDC 69 87 61 91 / 80 20 10 10 GCK 71 86 59 90 / 60 20 10 10 EHA 70 86 61 90 / 80 20 20 10 LBL 71 88 62 91 / 80 20 20 10 HYS 71 86 58 91 / 20 20 0 0 P28 76 99 68 94 / 80 20 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SUGDEN SHORT TERM...FINCH LONG TERM...BURGERT AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1246 AM EDT SAT AUG 4 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA THIS EVENING AND MOST OFF THE COAST OVERNIGHT. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR SATURDAY INTO SUNDAY. && .NEAR TERM /THROUGH TODAY/... 1245 AM UPDATE...NO SIGNIFICANT CHANGES NEEDED FOR THIS UPDATE. ONLY MADE MINOR TWEAKS TO TREND TOWARD CURRENT CONDITIONS. PREV DISCUSSION... CHALLENGES WILL ARE CONVECTION THIS AFTERNOON INTO THE EVENING AND HOW STRONG AND HOW EXTENSIVE WILL THE FOG BE. TSTMS FIRING ACROSS NORTHERN AND CENTRAL AREAS ATTM AHEAD OF THE APCHG COLD FRONT. STILL EXPECTING CONVECTION TO FIRE UP ACROSS PORTIONS OF THE CENTRAL HIGHLANDS AND DOWNEAST REGIONS LATER THIS AFTERNOON AS BEST INSTABILITY SHIFTS SSE. SPC MESO-ANALYSIS INDICATES THIS ATTM. ALSO, THINKING HEAVY RAINFALL AND STRONG WIND GUSTS STILL POSSIBLE. SBCAPES UP AROUND 2000+ JOULES W/LIS DOWN TO AROUND -5. 0-6KM SHEAR FROM THE LATEST RUC WAS AROUND 25KTS WHICH WOULD FAVOR POSSIBLE DOWNBURST WINDS. EXPECTING CONVECTION TO WIND DOWN THIS EVENING AS INSTABILITY AXIS SHIFTS EAST INTO NEW BRUNSWICK. COLD FRONT WILL CLEAR THE COAST TONIGHT W /DRIER-COOLER AIR EXPECTED TO FILTER BEHIND THE FRONT. MIDNIGHT CREW/S OVERNIGHT MINS OF LOW/MID 50S ACROSS THE NORTH W /MID-UPPER 50S CENTRAL AND DOWNEAST LOOKED GOOD. THE OTHER CONCERN IS FOG RETURNING OVERNIGHT INTO SATURDAY MORNING. DECIDED ON AREAS OF FOG RIGHT ALONG THE IMMEDIATE COAST AND OVER THE WATERS. FURTHER INLAND, WENT W/PATCHY FOG FOR NOW GIVEN THE DRYING TREND. THERE COULD BE A BRIEF TIME WHEN VSBYS DROP LOWER AS DEWPOINT ALIGNS W/THE TEMPERATURE. THIS WILL BE ESPECIALLY TRUE IN AREAS FROM EARLIER RAINFALL. HIGH PRES BUILDING INTO THE REGION FROM CANADA ON SATURDAY WILL PROVIDE DRY AND PLEASANT CONDITIONS FOR EARLY AUGUST. MAX TEMPERATURES SHOULD HAVE NO PROBLEM REACHING WELL INTO THE 80S W/AMPLE SUNSHINE. LATEST MOS/NAM MAXES MATCHED CLOSE TO WHAT THE MIDNIGHT CREW HAS AND THEREFORE ONLY TWEAKING WAS DONE FOR THE COAST TO BRING MAXES UP DUE TO OFFSHORE WINDS. && .SHORT TERM /TONIGHT THROUGH MONDAY/... A WARM FRONT WILL LIFT NORTH THROUGH THE REGION SATURDAY NIGHT INTO SUNDAY USHERING IN VERY WARM AND HUMID CONDITIONS. EXPECT HIGHS SUNDAY GENERALLY IN THE MID 80S WITH DEW POINTS RISING INTO THE MID TO HIGH 60S. WINDS WILL BE GUSTY OUT OF THE SOUTH AND THIS WILL HELP TO KEEP TEMPERATURES COOLER ALONG THE COAST WHERE HIGHS WILL BE IN THE 70S. CLOUDS WILL INCREASE IN THE AFTERNOON AHEAD OF AN APPROACHING COLD FRONT BUT ANY SHOWER/THUNDERSTORM ACTIVITY LOOKS TO REMAIN WEST OF THE REGION THROUGH THE DAY. AS THE COLD FRONT CONTINUES TO ADVANCE SUNDAY NIGHT SHOWERS WITH POSSIBLE THUNDERSTORMS WILL ROLL THROUGH FROM WEST TO EAST AHEAD OF FRONT DURING THE LATE EVENING INTO THE OVERNIGHT. INSTABILITY LOOKS TO BE MARGINAL DUE TO THE TIMING OF THE FRONT BEING AT NIGHT AND AS A RESULT ANY CONVECTION THAT OCCURS DOES NOT LOOK TO BE SEVERE, ALTHOUGH SOME HEAVY DOWNPOURS WILL BE POSSIBLE. BY MONDAY MORNING THE FRONT LOOKS TO BE SITUATED CLOSE TO THE WESTERN EDGE OF THE STATE. SHOWERS AND STORMS WILL CLEAR THE AREA FROM WEST TO EAST THROUGH THE DAY AS THE FRONT ADVANCES EAST. THE BEST CHANCE FOR ANY STRONGER STORMS MONDAY WILL BE DOWNEAST AS THAT AREA WILL BE LAST TO CLEAR DURING THE AFTERNOON. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ZONAL FLOW WILL DEVELOP BEHIND AN EXITING COLD FRONT MONDAY NIGHT. DRY WEATHER IS EXPECTED IN THE WAKE OF THIS FRONT THROUGH TUESDAY NIGHT. THE PERSISTENT SUMMER 2012 UPPER TROUGH RETURNS WEDNESDAY THROUGH FRIDAY. ANTICIPATE A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS DAYS 5 THROUGH 7 WITH DISTURBANCES ROTATING AROUND THE BASE OF THE TROUGH. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE LONG TERM PERIOD. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: VFR W/TEMPO MVFR THIS AFTERNOON INTO THE EVENING W/TSTMS FIRING. LEANED W/MVFR VSBY LATER TONIGHT INTO SATURDAY MORNING FOR THE NORTHERN TERMINALS WHILE KBGR AND KBHB ARE EXPECTED TO DROP TO IFR BY 09Z SATURDAY. AFTER 12Z SATURDAY, LOOKS LIKE VFR. SHORT TERM: LOOKS LIKE VFR SATURDAY NIGHT INTO SUNDAY FOR THE MOST PART. HOWEVER, MVFR AND IFR POSSIBLE ACROSS KBGR AND KBHB COULD BE SEEN EARLY SUNDAY MORNING AS WINDS BECOME SOUTHERLY AHEAD OF AN APPROACHING COLD FRONT. SUNDAY NIGHT INTO MONDAY COULD BE INTERESTING AS THAT STRONGER COLD FRONT MOVES ACROSS THE REGION W/POSSIBLE TSTMS AND WIND AND MVFR/IFR CONDITIONS. && .MARINE... NEAR TERM: NO HEADLINES. MAIN CHALLEGE WILL THE CONTINUING 4-5 FOOT SWELL WHICH IS OUT THERE ATTM. WINDS WILL INCREASE SOME OVERNIGHT W/THE COLD FROPA, BUT WINDS WILL RELAX ON SATURDAY AS HIGH PRES MOVES IN FROM CANADA. AREAS OF FOG WILL BE NUISANCE OVERNIGHT BUT VSBYS SHOULD IMPROVE LATER SATURDAY MORNING. USED THE NAM12 AND GFS FOR THE WINDS WHICH SUPPORT 10-15 KTS TONIGHT AND THEN SPEEDS FROP OFF FOR SATURDAY. BROUGHT THE SWELL DOWN TO 3 FT BY MIDDAY SATURDAY W/AN OFFSHORE FLOW. SHORT TERM: POSSIBLE SCA FOR SUNDAY NIGHT INTO MONDAY AS PRES GRADIENT TIGHTEN AHEAD AND W/THE FRONTAL PASSAGE. WINDS START COMING DOWN LATER MONDAY INTO TUESDAY. BACKED OFF A BIT ON THE WNAWAVE BY DROPPING THEM BACK 1-2 FEET. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HASTINGS/HEWITT SHORT TERM...FITZSIMMONS LONG TERM...OKULSKI AVIATION...HASTINGS/HEWITT MARINE...HASTINGS/HEWITT/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS DULUTH MN
323 AM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH SUNDAY. CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3 HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST. THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF HIGHEST MOISTURE/AND NEAREST THE UPPER LOW. IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN. TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE. .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY. && .AVIATION...06Z ISSUANCE WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z. && .POINT TEMPS/POPS... DLH 77 55 75 55 / 20 20 10 0 INL 75 47 76 56 / 60 40 10 0 BRD 76 55 76 55 / 20 10 10 0 HYR 79 54 75 53 / 40 10 10 0 ASX 81 58 76 56 / 40 10 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...MELDE LONG TERM....GSF AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
419 AM EDT SAT AUG 4 2012 .SYNOPSIS... A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY FORECAST. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90 PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE HOURS BEFORE THE SUN STARTS TO RISE. PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN. MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN. OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR 50 DEGREES. && .SHORT TERM /8 AM THIS MORNING THROUGH MONDAY/... AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8 AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS. CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER THE HIGHER TERRAIN. STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON. DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 419 AM EDT SATURDAY...ECMWF AND GFS MODELS SHOW A WEAK RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION MONDAY NIGHT AND WILL REMAIN OVER THE REGION THROUGH EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. ON WEDNESDAY...ECMWF AND GFS MODELS SHOW SOME WEAK SHORTWAVES WILL MOVE THROUGH THE REGION ON WEDNESDAY AND EARLY WEDNESDAY NIGHT. GFS AND ECMWF MODELS BOTH SHOW SOME CONVECTION DEVELOPING ALONG THE INTERNATIONAL BORDER BY WEDNESDAY AFTERNOON AND EARLY WEDNESDAY NIGHT...SO HAVE GONE WITH SLIGHT CHANCE POPS FOR SHOWERS AND THUNDERSTORMS NEAR THE CANADIAN BORDER. ON THURSDAY... MODEL GUIDANCE AGAIN SHOWING SOME MORE WEAK SHORTWAVES MOVING THROUGH THE REGION...SO HAVE GONE WITH SLIGHT CHANCE POPS FOR SHOWERS AND THUNDERSTORMS ON THURSDAY. EXPECTING DRY CONDITIONS THURSDAY NIGHT. ON FRIDAY...ECMWF AND GFS MODELS IN GOOD AGREEMENT IN SHOWING A LOW AT THE SURFACE AND ALOFT MOVING EAST FROM THE WESTERN GREAT LAKES... WITH BOTH MODELS SHOWING SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE REGION ON FRIDAY. ECMWF AND GFS MODELS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. THUS...FORECASTER CONFIDENCE IS HIGH. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... THROUGH 06Z SUNDAY...MAINLY VFR THROUGH THE PERIOD...EXCEPT FOR SOME MORNING VALLEY FOG ACROSS THE SHELTERED VALLEYS OF EASTERN AND NORTHEAST VERMONT...AS WELL AS THE VALLEYS OF THE ADIRONDACKS ...WITH SOME AREAS OF IFR/LIFR IN FOG UNTIL 13Z SATURDAY...ESPECIALLY AT KSLK AND KMPV. LATEST MODEL GUIDANCE INDICATING STEEP LOW LEVEL LAPSE RATES DEVELOPING ACROSS THE REGION TODAY...WITH CONDITIONS DESTABILIZING BY THIS AFTERNOON. MODEL GUIDANCE INDICATING THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS TODAY WILL BE ACROSS THE WESTERN SLOPES OF THE GREEN MOUNTAIN IN VERMONT...AND OVER THE ADIRONDACKS IN NORTHERN NEW YORK. HAVE INCLUDED A MENTION OF THUNDERSTORMS IN THE VICINITY AFTER 18Z SATURDAY IN THE TAFS AT KMPV...KRUT AND KSLK. EXPECTING ANY STORMS THAT DEVELOP TODAY WILL BEGIN TO DISSIPATE AROUND 00Z SUNDAY...WITH THE LOSS OF DAYTIME SURFACE HEATING. OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY SUNDAY. MVFR/IFR IN BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z SUNDAY. APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL. COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. && .MARINE... LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY. HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED. WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4 FEET BY SUNDAY. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...NEILES NEAR TERM...KGM/BOYD SHORT TERM...NEILES LONG TERM...WGH AVIATION...WGH/RJS MARINE...KGM/MUCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
235 AM EDT SAT AUG 4 2012 .SYNOPSIS... A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY FORECAST. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90 PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE HOURS BEFORE THE SUN STARTS TO RISE. PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN. MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN. OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR 50 DEGREES. && .SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/... AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8 AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS. CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER THE HIGHER TERRAIN. STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON. DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 344 PM EDT FRIDAY...ECMWF AND GFS INDICATE A CHANCE OF SHOWERS EARLY MONDAY...MAINLY ACROSS VERMONT...AS COLD FRONT AND UPPER TROUGH PUSH EAST OF THE REGION. MID LEVEL DRY SLOT THEN BUILDS IN BY MIDDAY...SO EXPECT CLEARING SKIES ACROSS THE REGION BY MONDAY AFTERNOON. IT WILL TURN LESS HUMID AND BE A LITTLE COOLER...WITH HIGHS GENERALLY IN THE UPPER 70S AND LOWER 80S. ECMWF AND GFS REMAIN IN GOOD AGREEMENT IN SHOWING A WEAK RIDGE OF HIGH PRESSURE OVER THE NORTH COUNTRY FROM MONDAY NIGHT THROUGH EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. A SERIES OF WEAK UPPER SHORTWAVES WILL THEN MOVE ACROSS THE REGION WEDNESDAY AFTERNOON THROUGH THURSDAY...BRINGING A LOW CHANCE FOR SHOWERS AND STORMS TO THE REGION...ESPECIALLY TO THE HIGHER TERRAIN AND ACROSS THE NORTHERN ZONES. LATEST ECMWF INDICATING A MORE PRONOUNCED TROUGH MOVING INTO THE NORTHEAST FRIDAY...SO HAVE GONE WITH CHANCE POPS ACROSS THE ENTIRE AREA FRIDAY INTO FRIDAY NIGHT. TEMPERATURES WILL BE A BIT ABOVE NORMAL TUESDAY THROUGH THURSDAY...THEN LOWER TO SEASONAL LEVELS FRIDAY DUE MORE CLOUD COVER. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... THROUGH 06Z SUNDAY...MAINLY VFR THROUGH THE PERIOD...EXCEPT FOR SOME MORNING VALLEY FOG ACROSS THE SHELTERED VALLEYS OF EASTERN AND NORTHEAST VERMONT...AS WELL AS THE VALLEYS OF THE ADIRONDACKS ...WITH SOME AREAS OF IFR/LIFR IN FOG UNTIL 13Z SATURDAY...ESPECIALLY AT KSLK AND KMPV. LATEST MODEL GUIDANCE INDICATING STEEP LOW LEVEL LAPSE RATES DEVELOPING ACROSS THE REGION TODAY...WITH CONDITIONS DESTABILIZING BY THIS AFTERNOON. MODEL GUIDANCE INDICATING THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS TODAY WILL BE ACROSS THE WESTERN SLOPES OF THE GREEN MOUNTAIN IN VERMONT...AND OVER THE ADIRONDACKS IN NORTHERN NEW YORK. HAVE INCLUDED A MENTION OF THUNDERSTORMS IN THE VICINITY AFTER 18Z SATURDAY IN THE TAFS AT KMPV...KRUT AND KSLK. EXPECTING ANY STORMS THAT DEVELOP TODAY WILL BEGIN TO DISSIPATE AROUND 00Z SUNDAY...WITH THE LOSS OF DAYTIME SURFACE HEATING. OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY SUNDAY. MVFR/IFR IN BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z SUNDAY. APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL. COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. && .MARINE... LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY. HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED. WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4 FEET BY SUNDAY. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...NEILES NEAR TERM...KGM/BOYD SHORT TERM...NEILES LONG TERM...RJS AVIATION...WGH/RJS MARINE...KGM/MUCCILLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
138 AM EDT SAT AUG 4 2012 .SYNOPSIS... A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY... FOLLOWED BY COOLER DRY WEATHER ON MONDAY. && .NEAR TERM /THROUGH TODAY/... 930 AM UPDATE...NO CHGS TO CRNT FCST WITH A QUIET OVRNGT PD XPCTD. PREV BLO... 730 PM UPDATE...WELL IT TOOK SOME OF THE HIGHEST TRRN IN THE CWA TO HELP TRIGGER AN ISOLD TSRA OVER CNTRL DELAWARE CNTY. STORM BCM ANCHORED NEAR MT PISGAH AND BACK-BUILT/TRAINED FOR NEARLY 2 HRS. RR AMTS UP 3-3.5 INCHES. THIS STORM HAS SINCE DSPTD AND SEE LTL POTNL FOR ADDNL DVLPMNT ACRS THE FCST AREA...SO WILL REMOVE POPS AND GO WITH MAINLY CLEAR TO SKC TNGT. FOG POTNL ALSO LIMITED AND DON`T XPCT IT TO BE DENSE ENUF TO INCLUDE IN THE WX GRIDS. PREV BLO... 4 PM UPDATE...MAINLY SKC ACRS THE BGM FCST AREA WITH XCPTN OF SOME MID/HI CLD ACRS THE FINGER LAKES AND FAR SE ZONES. WSR-88D SHOWS A WEAK E-W BNDRY BNDRY FROM SRN SCHUYLER/TOMPKINS ACRS NRN BROOME INTO SRN CHENANGO CNTY. HOWEVER...TD`S ARE LOWEST ACRS THE SRN TIER AND ANY LOW LVL CONVERGENCE WILL BE WEAK DUE TO THE LGT WINDS VCNTY OF THE BNDRY. LACK OF UPR DYNAMICS AND LOW LVL CIN CONTINUE TO IMPEDE DVLPMNT. GIVEN THESE TRENDS...WE LOWERED POPS TO SLGT CHC FOR LATE THIS AFTN/EVNG AND LOWERED SKY CVR. PREV BLO... 2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS (DOWN BURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS EVENING WILL DIMINISH QUICKLY THIS EVENING. WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE 1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S. && .SHORT TERM /TONIGHT THROUGH MONDAY/... DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING. THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z. ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND 0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN. HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW. HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND 12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION. CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY. IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE 90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED. COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND WILL LEAN WITH THEIR GENTLER APPROACH. ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS... THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... IN GENERAL VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PERIOD. THERE MAY BE MVFR VSBY RESTRICTIONS DUE TO HZ/BR AT KELM/KAVP EARLY THIS MORNING BETWEEN 09Z-12Z. JUST SCATTERED CI THROUGH MID MORNING THEN SCT CU AROUND 5K FT TODAY. ISOLATED CONVECTION IS POSSIBLE THIS AFTERNOON IN THE HIGHER TERRAIN BUT NOT INCLUDED IN TAFS DUE TO VERY LIMITED AREAL COVERAGE. OVERNIGHT AS NEXT SYSTEM APPROACHES REGION SCT MID CLOUDS ARE LIKELY. WINDS WILL BE LIGHT AND VARIABLE INTO MID MORNING THEN SOUTHERLY AROUND 10 KNOTS BECOMING SOUTHEAST TONIGHT AROUND 5 KNOTS. OUTLOOK... SUN MORNING...VFR WITH POSSIBLE MVFR VSBYS RESTRICTIONS EARLY SUN AM DUE TO HAZE. SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS WITH MVFR/IFR RESTRICTIONS IN STORMS. MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...JAB NEAR TERM...HEDEN SHORT TERM...JAB LONG TERM...JAB AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1257 AM EDT SAT AUG 4 2012 .SYNOPSIS... A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY FORECAST. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90 PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE HOURS BEFORE THE SUN STARTS TO RISE. PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN. MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN. OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR 50 DEGREES. && .SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/... AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8 AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS. CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER THE HIGHER TERRAIN. STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON. DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 344 PM EDT FRIDAY...ECMWF AND GFS INDICATE A CHANCE OF SHOWERS EARLY MONDAY...MAINLY ACROSS VERMONT...AS COLD FRONT AND UPPER TROUGH PUSH EAST OF THE REGION. MID LEVEL DRY SLOT THEN BUILDS IN BY MIDDAY...SO EXPECT CLEARING SKIES ACROSS THE REGION BY MONDAY AFTERNOON. IT WILL TURN LESS HUMID AND BE A LITTLE COOLER...WITH HIGHS GENERALLY IN THE UPPER 70S AND LOWER 80S. ECMWF AND GFS REMAIN IN GOOD AGREEMENT IN SHOWING A WEAK RIDGE OF HIGH PRESSURE OVER THE NORTH COUNTRY FROM MONDAY NIGHT THROUGH EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. A SERIES OF WEAK UPPER SHORTWAVES WILL THEN MOVE ACROSS THE REGION WEDNESDAY AFTERNOON THROUGH THURSDAY...BRINGING A LOW CHANCE FOR SHOWERS AND STORMS TO THE REGION...ESPECIALLY TO THE HIGHER TERRAIN AND ACROSS THE NORTHERN ZONES. LATEST ECMWF INDICATING A MORE PRONOUNCED TROUGH MOVING INTO THE NORTHEAST FRIDAY...SO HAVE GONE WITH CHANCE POPS ACROSS THE ENTIRE AREA FRIDAY INTO FRIDAY NIGHT. TEMPERATURES WILL BE A BIT ABOVE NORMAL TUESDAY THROUGH THURSDAY...THEN LOWER TO SEASONAL LEVELS FRIDAY DUE MORE CLOUD COVER. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTED AT MOST LOCATIONS THROUGH THE PERIOD. THE ONLY EXCEPTION TO THIS WILL BE SOME VLIFR CONDITIONS AT KSLK AND KMPV BETWEEN 07Z AND 13Z DUE TO LOW CLOUDS AND FOG. SCATTERED CUMULUS CLOUDS SHOULD FORM SATURDAY AFTERNOON AND ISOLATED STORMS WILL DEVELOP AFTER 20Z. WINDS WILL GENERALLY BE LIGHT AND VARIABLE TONIGHT...THEN TREND TOWARD A MORE SOUTHERLY DIRECTION LATE SATURDAY MORNING INTO AFTERNOON. OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY SUNDAY. THERE WILL BE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON/EVENING WITH BRIEF MVFR POSSIBLE. MVFR/IFR IN BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z SUNDAY. APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL. COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. && .MARINE... LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY. HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED. WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4 FEET BY SUNDAY. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...NEILES NEAR TERM...KGM/BOYD SHORT TERM...NEILES LONG TERM...RJS AVIATION...EVENSON/RJS MARINE...KGM/MUCCILLI
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
340 AM EDT SAT AUG 4 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 330 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW TO EVOLVE THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM. && .SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...EXPECT MVFR AND/OR IFR VSBYS FROM BR/FG DURING THE 08Z-13Z TIME FRAME. FLO AND/OR LBT TERMINALS WILL HAVE THE GREATER POTENTIAL TO OBSERVE PREVAILING BR/FG...WHEREAS THE COASTAL TERMINALS WILL INDICATE TEMPO MVFR VSBYS. COULD OBSERVE A SUB-1000 FT CLOUD DECK ALONG THE COASTAL TERMS WITHIN A 4 HR WINDOW SURROUNDING SUNRISE. BY MID-MORNING...ANY RESIDUAL BR SHOULD DISSIPATE...LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY. THE PROB OF THUNDERSTORMS REMAINS ON THE LOW SIDE...BUT ENOUGH CONFIDENCE TO MENTION VCTS AT ALL TERMINALS FROM MIDDAY THROUGH EARLY THIS EVENING. PREVAILING SE-S WINDS AT 5 TO 10 KT EXPECTED...UP TO 15 KT AT THE COASTAL TERMINALS. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 330 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT... WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE BAHAMAS TO AND ACROSS THE FLORIDA PENINSULA SUNDAY. WIND SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE CLOSER PROXIMITY OF THE EFFECTS FROM THE INVERTED SFC TROF. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE RULED OUT EARLY ACROSS THE OUTER WATERS. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...DCH SHORT TERM...SHK LONG TERM...SHK AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
329 AM EDT SAT AUG 4 2012 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN FROM THE EAST THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND TUESDAY BUT WILL STALL AND WEAKEN WEST OF THE AREA WEDNESDAY THROUGH LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 3 AM SATURDAY...LATEST RAP MODEL ALONG THE NAM12/GFS SHOW A THREAT OF SOME SHOWERS AND POSSIBLE TSTMS WILL AFFECT THE COAST DURING THE EARLY MORNING HOURS AS STRONG MID-LEVEL VORT CENTER TRACKS UP THE CAROLINA COAST IN AN UPPER-LEVEL WEAKNESS. RADAR ALREADY SHOWING SOME SHOWERS DEVELOPING ABOUT 100 MILES DUE SOUTH OF THE CRYSTAL COAST...SO HAVE RAISED POPS TO LOW CHC ALONG THE COAST THROUGH MIDDAY. ADDITIONAL ISOLATED SHOWERS WITH A FEW TSTMS MAY OCCUR ALONG THE SEA BREEZE LATER THIS AFTERNOON AND WILL HAVE A SLIGHT CHC ALONG THE SEA BREEZE ZONE AT THAT TIME. MAX TEMPS SHOULD MAINLY BE IN THE UPPER 80S TO AROUND 90 UNDER PARTLY CLOUDY SKIES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... AS OF 3 AM SATURDAY...THE COMBINATION OF A MOIST ONSHORE FLOW AND SOME WEAK MID-LEVEL VORTICITY MAY LEAD TO A REPEAT OF THIS MORNING WITH A FEW SHOWERS ALONG THE COAST IN THE OVERNIGHT HOURS AND WILL HAVE A SLIGHT CHC POP. OTHERWISE...A PARTLY CLOUDY WARM AND MUGGY NIGHT WITH MIN TEMPS IN THE 73 TO 78 DEGREE RANGE. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 330 AM SATURDAY...LONG TERM MODELS STILL IN GENERALLY GOOD AGREEMENT ON SYNOPTIC REGIME THROUGH THE COMING WEEK. BERMUDA HIGH WILL REMAIN SOUTH AND EAST OF THE REGION...WHILE BROAD TROUGH EXISTS ACROSS EASTERN HALF OF CONUS. FLOW WILL REMAIN SOUTHWESTERLY... SUPPLYING E NC WITH WARM AND HUMID CONDITIONS...WHILE WEAK SHORTWAVES AND STATIONARY FRONT ACROSS CENTRAL NC BRINGS CHANCES FOR CONVECTIVE ACTIVITY EACH DAY. BEST CHANCES FOR THUNDERSTORMS WILL BE IN THE AFTERNOON HOURS...THOUGH RAIN CHANCES MAY LINGER THROUGH THE EVENING HOURS. BEST CHANCES FOR WIDESPREAD RAIN AND STORMS WILL BE AROUND MID TO LATE WEEK TIME FRAME. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... /SHORT TERM TODAY AND TONIGHT/... AS OF 1 AM SAT...SOME MVFR FOG HAS DEVELOPED AT KEWN AND KISO AND GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER EXPECT SOME PATCHY FOG THROUGH THE EARLY MORNING HOURS. SAT WILL SEE CONTINUED S FLOW WITH ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON. /LONG TERM SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM SATURDAY...MAINLY VFR CONDITIONS WILL PREVAIL...THOUGH AS IS THE CASE MOST EVENING...SOME REDUCTIONS TO MVFR/IFR POSSIBLE LATE AS RADIATION FOG/LOW STRATUS DEVELOPS...ESP IN AREAS THAT RECEIVE RAINFALL. SCT MAINLY AFTERNOON THUNDERSTORMS WILL BRING TEMPO REDUCTIONS IN VSBYS THROUGH THE COMING WEEK. && .MARINE... /SHORT TERM TODAY AND TONIGHT/... AS OF 310 AM SATURDAY...WINDS HAVE DROPPED A BIT IN THE PAST COUPLE OF HOURS AND ARE GENERALLY 12 KNOTS OR LESS FROM THE S/SW WITH SEAS AT 1 TO 3 FEET WITH 7 TO 8 SECOND SWELLS. NOT PLANNING ANY MAJOR CHANGES TO MARINE FORECAST AS S/SW WINDS WILL CONTINUE TO CIRCULATE AROUND HIGH PRESSURE TO THE EAST WITH FRONTAL BOUNDARY REMAINING WELL OFF TO THE WEST IN THE OHIO VALLEY. THIS WILL LEAD TO S/SW WINDS 10 TO 15 KNOTS WITH SEAS 2 TO 3 FEET THROUGH TONIGHT. /LONG TERM SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM SATURDAY...SOUTHWEST FLOW WILL CONTINUE THROUGH THE LONG TERM...WITH WINDS GENERALLY 10 TO 15 KNOTS OVER THE WATERS... AND AROUND 10 KT OVER THE SOUNDS. SEAS WILL REMAIN IN THE 3 TO 4 FT RANGE ACROSS OUTER WATERS WITH 2 TO 3 FEET NEARSHORE. THERE WILL BE CHANCES FOR THUNDERSHOWERS THROUGH THE COMING WEEK AS A COOL FRONT AND TROUGH SAGS INTO CENTRAL AND EASTERN NC AND STALLS OUT NEARBY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...CTC NEAR TERM...CTC SHORT TERM...CTC LONG TERM...TL AVIATION...CTC/TL MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
102 AM EDT SAT AUG 4 2012 .SYNOPSIS... WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TONIGHT AS HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1255 AM SATURDAY...SIGNALS IN SEVERAL OF THE SHORT-TERM MODELS INDICATE A DECENT MID-LEVEL SHORTWAVE TO MOVE NORTH ACROSS EASTERN NORTH CAROLINA IN WEAKNESS BETWEEN AREAS OF HIGH PRESSURE WELL TO THE EAST AND OVER THE SOUTHERN PLAINS. THE RAP/GFS AND TO A LESSER EXTENT THE NAM ALL SHOW LIGHT QPF NEAR THE COAST FROM ABOUT 10Z THIS MORNING INTO EARLY AFTERNOON. HAVE FOLLOWED SUIT WITH CHANCE POPS NEAR THE COAST TAPERING TO NIL WEST OF HIGHWAY 17 THROUGH EARLY AFTERNOON. NO OTHER MAJOR CHANGES TO THE FORECAST AT THIS TIME. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... AS OF 340 PM FRI...UPPER LEVEL RIDGE BEGINS TO MIGRATE WEST INTO EASTERN NC ON SAT ALTHOUGH LOW LEVEL THICKNESSES CHANGE LITTLE...RANGING 1415-1420 METERS WHICH WILL YIELD MAX TEMPS IN THE LOWER 90S INLAND TO UPPER 80S ALONG THE COAST. FORECAST SOUNDINGS INDICATE AN UNSTABLE AIRMASS WILL PERSIST SAT WITH PWATS OVER 1.75 INCHES...CAPE VALUES ABOVE 3000 J/KG AND LIFTED INDICES OF -7 TO -9 C. CONTINUED FORECAST FOR DIURNAL CONVECTION INLAND ASSOCIATED WITH SEA BREEZE BOUNDARY PROPAGATION FOR THE AFTERNOON HOURS. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... AS OF 155 PM FRI...MODELS IN GOOD AGREEMENT IN THE LONG TERM. WARM AND HUMID THROUGH THE PERIOD WITH THE BERMUDA HIGH RIDGING ACROSS THE SOUTHEAST MAINTAINING A SOUTHWEST FLOW. A COLD FRONT WILL APPROACH FROM THE NORTHWEST EARLY NEXT WEEK BUT WILL BECOME STATIONARY OVER THE CENTRAL PART OF THE STATE. THE FRONT WILL DISSIPATE BY MIDWEEK LEAVING A WEAK SURFACE THROUGH THROUGH FRIDAY. TYPICAL SUMMERTIME WEATHER WITH SCATTERED MAINLY DIURNAL SHOWERS AND THUNDERSTORMS. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 00Z SUNDAY/... AS OF 1 AM SAT...SOME MVFR FOG HAS DEVELOPED AT KEWN AND KISO AND GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER EXPECT SOME PATCHY FOG THROUGH THE EARLY MORNING HOURS. SAT WILL SEE CONTINUED S FLOW WITH ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON. LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/ AS OF 150 PM FRI...SOUTHWEST SURFACE FLOW WILL PERSIST THROUGH THE PERIOD...GENERALLY 10-15 KNOTS BY DAY AND LESS THAN 10 KNOTS AT NIGHT. SCATTERED MAINLY AFTERNOON/EVENING THUNDERSTORMS WITH LOCALLY LOWER CEILINGS/VISIBILITIES. && .MARINE... SHORT TERM /THROUGH SATURDAY/... AS OF 1 AM SAT...WINDS ARE RUNNING JUST A BIT ABOVE FORECAST VALUES WITH OBSERVED VALUES NEAR 15 KNOTS AT OREGON INLET...DIAMOND BUOY AND CAPE LOOKOUT. HAVE UPPED THE WINDS BASED ON THE LATEST RAP MODEL. SEAS REMAIN IN THE 2 TO 3 FEET RANGE AND NO CHANGES NEEDED TO THE WAVEHEIGHT FORECAST. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/ AS OF 150 PM FRI...LATEST RUNS OF THE ECMWF/GFS/NAM IN VERY CLOSE AGREEMENT THROUGH THE LONG TERM PERIOD SO USED AN OVERALL BLEND. THE BERMUDA HIGH WILL BE THE MAIN FEATURE IN THE WEATHER MAINTAINING A SOUTHWEST FLOW BUT SPEEDS AND SEAS WILL REMAIN BELOW SMALL CRAFT LEVELS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DAG NEAR TERM...CTC SHORT TERM...DAG LONG TERM...HSA AVIATION...CTC/HSA/JBM MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
452 AM EDT SAT AUG 4 2012 .SYNOPSIS... SCATTERED SHOWERS AND A POSSIBLE THUNDERSTORM WILL OCCUR TODAY AS LOW LEVEL MOISTURE INCREASES OVER THE AREA. MORE ACTIVE WEATHER WILL BEGIN WHEN A STRONG COLD FRONT WILL INTERACT WITH AN UPPER LEVEL DISTURBANCE TO BRING SHOWERS AND THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY. THE FRONT WILL PUSH EAST OF THE AREA SUNDAY NIGHT INTO MONDAY...ALLOWING HIGH PRESSURE AND DRIER AIR TO BUILD INTO THE AREA. NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES CAN THEN BE EXPECTED DURING THE FIRST PART OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... INCREASING SHOWER ACTIVITY IN AMPLE LL MOISTURE AND INCREASING INSTABILITY THROUGH TODAY. HRRR SEEMS TO HAVE A HANDLE ON CURRENT ACTIVITY. COVERAGE NOT EXPECTED TO BE WIDESPREAD...SO HAVE OPTED FOR CHANCE SHRA WITH ISOLD THUNDER THIS MORNING...AND SCT TSTMS THIS AFTERNOON. WITH LACK OF ORGANIZED SURFACE OR UPPER AIR FEATURE...EXPECTATION IS STILL THAT OF UNORGANIZED CONVECTION. WITH LOW LEVEL CLOUDS...HAVE BROUGHT HIGH TEMPERATURES DOWN IN ESPECIALLY THE SOUTHERN HALF OF THE AREA. WITH EXPECTANT CLOUD COVER TODAY...NO HEAT ADVISORY CRITERIA MET WITH SLIGHTLY LOWERED TEMPERATURES. WILL STILL KEEP MENTION IN THE HWO AS VALUES DO APPROACH 100 DEGREES. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... SOME TIMING DIFFERENCES WITH THE MAIN EXPECTATION OF CONVECTION AND SUBSEQUENT FRONTAL PASSAGE...WITH THE GFS A LITTLE FASTER THAN BOTH THE NAM AND ECMWF. HAVE OPTED FOR THE TIMING OF THE LATTER TWO MODELS. EARLY PART OF SAT EVENING CONTINUES FAIRLY DISORGANIZED CONVECTION...WITH THE MORE ORGANIZED DYNAMICALLY DRIVEN ACTIVITY TO BEGIN AFTER 00-06Z TIMEFRAME IN THE ILN AREA. AS THE S/WV DIGS INTO THE UPR MS VALLEY AND APPROACHING WESTERN IN...SOUTHERLY LL FLOW CONTINUES TO PUMP VERY MOIST AIR INTO THE REGION. IN ADDITION TO CONCERN FOR SEVERE WITH THE PRE FRONTAL ACTIVITY...THERE STILL IS POTENTIAL FOR MCS AHEAD OF THIS WITH THE DEVELOPMENT OF A 40 KT+ LLJ (SLIGHTLY WEAKER IN THE ECMWF BUT STILL ENHANCED) AND SIGNIFICANT MOISTURE TRANSPORT. WHILE THERE ISNT STRONG EVIDENCE OF BACK BUILDING STORMS...WARM CLOUD DEPTHS OF NEAR 4500M AND PW VALUES BETWEEN 2.25-2.5 INCHES WILL MAKE FOR POTENTIAL OF VERY HIGH RAINFALL RATES. WITH ENHANCED LL JET AND INCREASING DYNAMICS IN ADDITION TO RESPECTIBLE ML CAPE...POTENTIAL FOR DAMAGING WINDS...WTH POSSIBILITY OF LARGE HAIL. FIRST SHOT OF CONVECTION/POTENTIAL MCS TO EXIT THE AREA BEFORE IN THE 15Z TIMEFRAME...AND THEN STILL SEVERE POTENTIAL AHEAD OF THE FRONT IN THE AFTERNOON DEPENDING ON HOW WORKED OVER THE AIRMASS IS AFTER PASSAGE OF MORNING CONVECTION. HAVE SLOWED DOWN THE TIMING OF THIS CONVECTION TO NOT EXIT THE AREA UNTIL AFTER 00Z...WTH PRECIP LINGERING LONGEST IN THE SE. WITH AMPLE CLOUDS HAVE CONTINUED TO KEEP TEMPS BELOW 90 FOR SUNDAY. FOR SUN NIGHT SKIES TO BEGIN CLEARING IN THE WEST WITH TEMPS DROPPING TO UPR 50S HERE RANGING TO UP 60S SOUTHAST. DRY CONDITIONS AND NEAR NORMAL TEMPERATURES FOR MONDAY AND TUE. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... THE COLD FRONT AND ALL ASSOCIATED PRECIPITATION WILL SHIFT OF TO OUR EAST MONDAY MORNING AS LOW LEVEL RIDGING BUILDS ACROSS THE REGION. SKIES WILL BE MOSTLY CLEAR DURING THE DAY WITH CONTINUED COLD ADVECTION KEEPING TEMPERATURES NEAR...TO JUST BELOW SEASONABLE VALUES DURING THE DAY. THE HIGH PRESSURE AREA WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH TUESDAY NIGHT. THIS WILL KEEP US DRY WITH LIGHT WINDS AND ONLY A FEW PASSING CLOUDS. TEMPERATURES MONDAY NIGHT WILL BE THE COOLEST OF THE WEEK...WITH FORECAST LOWS RANGING FROM THE LOW 60S ACROSS THE SOUTH...TO THE MID 50S ACROSS THE NORTHEAST. BY WEDNESDAY...TEMPERATURES ALOFT BEGIN TO WARM AS A SHORTWAVE OVER THE PLAINS PUSHES PART THEIR VERY WARM AIRMASS TOWARD THE OHIO VALLEY. THIS WILL BRING A REBOUND OF TEMPERATURES BACK TO ABOVE SEASONABLE VALUES FOR THE MIDDLE OF THE WEEK. THE SHORTWAVE WILL THEN SLIDE EASTWARD...BRINGING INCREASING CHANCES FOR PRECIPITATION TOWARD THE END OF THE WEEK. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS MAY BE INTERRUPTED BY BR TONIGHT IN A HUMID AIRMASS. SCATTERED CONVECTION TRIGGERED BY WEAK DISTURBANCES IN AN UNSTABLE REGIME WILL AFFECT TAF SITES ON SATURDAY. WINDS WILL BE OUT OF THE SOUTH WITH GUSTS NEAR 20 KNOTS SATURDAY AFTERNOON. .OUTLOOK...SHOWERS AND THUNDERSTORMS ARE LIKELY SATURDAY NIGHT AND SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...JDR NEAR TERM...JDR SHORT TERM...JDR LONG TERM...LATTO AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
330 AM CDT SAT AUG 4 2012 .TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM BIG CONCERN IS IMPACT OF CURRENT LINE OF CONVECTION ON THE EVOLUTION AND TIMING OF THUNDERSTORMS ACROSS FORECAST AREA LATER TODAY. SUB-SEVERE WIND REPORTS SINCE 12 MIDNIGHT HAVE INDICATED A WEAKENING TREND TO THE LINE...SUPPORTED BY REDUCED LIGHTNING ACTIVITY AND A SLIGHT WARMING OF CLOUD TOPS. LINE WILL REACH NW CWA BETWEEN 245 AM AND 3AM ON CURRENT PACE. HRRR AND RAP SUGGEST A RAPID WEAKENING OF CURRENT LINE AS IT MOVES AWAY FROM MAIN LOW-LEVEL JET AXIS AND INSTABILITY...THEN ALL MODELS SHOW A RE-FIRING OF CONVECTION ALONG SURFACE FRONT MID-LATE MORNING FROM WEST CENTRAL WI INTO FAR NE IOWA AS FRONTOGENETIC RESPONSE INCREASES AHEAD OF TROUGH. STILL FEEL BEST OPPORTUNITY FOR STRONG/SEVERE IN CWA DURING THE LATE AFTERNOON INTO THIS EVENING WITH ENHANCED FORCING AND 0 TO 6KM SHEAR INCREASING TO 30 TO 40 KTS AHEAD OF COLD FRONT AND POSITIVE-TILT 500 MB TROUGH AS IT SWINGS TO A MORE NEUTRAL POSITION WHILE CROSSING THE WESTERN GREAT LAKES TONIGHT. FORCING FOR ASCENT WILL BE AIDED BY UPPER LEVEL DIVERGENCE OF RRQ OF 100-110KT 250 MB JET MAX LIFTING ACROSS WRN GREAT LAKES REGION DURING THE LATE AFTERNOON AND EVENING. IF CLOUD DEBRIS DOESN/T OVERLY INHIBIT DAYTIME HEATING...SURFACE BASED CAPE OVER CWA RISES TO AROUND 1600 J/KG...COMPUTED LIFTED INDICES OF -5 TO -7...PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES. FEEL CLOUDS WILL THIN ENOUGH AND WARM ADVECTION AHEAD OF FRONT WILL BRING HIGH TEMPERATURES IN THE LOW 90S INLAND...WITH SOUTHERLY WINDS TURNING INSHORE ENOUGH TO KEEP LAKESHORE AREAS IN THE MID-UPPER 80S. BUFKIT SOUNDINGS SHOW WELL MIXED BOUNDARY LAYER BY LATE AFTERNOON...WITH DRY SUB-CLOUD LAYER ENHANCING POTENTIAL FOR DAMAGING WINDS REFLECTED IN FORECAST DOWNDRAFT CAPE OF 1500 TO 2000 J/KG. PRECIPITATION ENDS IN THE EAST WITH TROUGH PASSAGE AROUND 06Z WITH DRIER AIR POURING IN ON NORTHWEST WINDS AS HIGH BUILDS IN FROM THE WEST. .SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH HIGH PRESSURE TO MOVE IN BEHIND THE COLD FRONT FOR SUNDAY AND MONDAY...BRINGING PLEASANT WEATHER TO SOUTHERN WISCONSIN. MAY SEE A FEW LINGERING CLOUDS NORTH SUNDAY AS THE UPPER TROUGH AXIS SWINGS THROUGH...WITH SUNNY SKIES ACROSS THE FORECAST AREA MONDAY. COOLER AIR BEHIND THE DEPARTING SYSTEM WILL RETURN TEMPERATURES TO NEAR NORMAL SUNDAY...WARMING BACK UP JUST A BIT MONDAY. .TUESDAY AND WEDNESDAY....FORECAST CONFIDENCE...MEDIUM MAY SEE A WEAK WAVE OR TWO SLIDE THROUGH TUESDAY AND WEDNESDAY...BUT OVERALL PRECIP CHANCES TOO LOW FOR POPS AT THIS TIME. WARM ADVECTION IS EXPECTED INTO THE AREA WITH UPPER RIDGE TO THE WEST...SO SHOULD SEE TEMPS RUN A FEW DEGREES ABOVE NORMAL. .THURSDAY AND FRIDAY...FORECAST CONFIDENCE...MEDIUM MODELS ADVERTISING A STRONGER WAVE FOR THURSDAY...SO WENT WITH CHANCE POPS MOST PLACES. LOOKS QUIETER FOR FRIDAY BEHIND THE SYSTEM. NO BIG CHANGE EXPECTED IN TEMPS THROUGH THE END OF THE WORK WEEK...WITH 80S CONTINUING. && .AVIATION/12Z TAFS/... WILL ADJUST TAFS FOR MVFR/IFR FOG IN THE NEAR TERM...THEN VFR UNTIL EXPECTED THUNDERSTORMS BRING MVFR CONDITIONS AND GUSTY WINDS. 000Z AND RAPID REFRESH MODELS SUPPORT KEEPING LATE AFTERNOON/EARLY EVENING TIMING FOR THUNDERSTORMS THAT IS IN CURRENT FORECAST. NORTHWEST WINDS KEEP BOUNDARY LAYER MIXED...WITH DRY AIR MOVING IN BEHIND COLD FRONT KEEPING OUT ANY CHANCE OF POST-FRONTAL LOW CLOUDS/FOG AT THIS TIME. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
246 AM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH MONDAY 246 AM CDT SAT AUG 4 2012 MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY. SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO NORTHERN IOWA. ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI- RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO 40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING. ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA. THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA. WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP. SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL FOR LESS CONVECTION TO OCCUR. ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY 246 AM CDT SAT AUG 4 2012 THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY. && .AVIATION... 1120 PM CDT FRI AUG 3 2012 LINE OF CONVECTION CONTINUES TO TRACK EAST ACROSS MN LATE THIS EVENING...AND THIS WILL IMPACT KRST AND KLSE. AT ITS CURRENT PACE IT WILL REACH KRST BY 0530Z AND KLSE NEAR 07Z. THE STORMS ARE PACKING QUITE A BIT OF WIND...EXPECT NORTHWEST GUSTS UPWARDS OF 40 TO 50 KTS AT KRST...CLOSER TO 40 KTS AT KLSE. THE LINE SHOULD SWEEP EAST OF KRST BY 09Z AND KLSE BY 11Z. MORE SHRA/TS WILL MOVE IN LATER SAT MORNING...CONTINUING INTO THE AFTERNOON...AS A COLD FRONT DRIVES EAST ACROSS THE REGION. NAM12 BRINGS IT ACROSS KRST AROUND 16Z AND KLSE NEAR 18Z. SOME OF THESE STORMS COULD ALSO BECOME STRONG TO SEVERE...WITH WIND AND HAIL THE THREATS. THE GREATER THREAT WILL LIKELY BE AT KLSE WHERE TIMING WILL FAVOR MORE INSTABILITY...AND THUS THE POTENTIAL FOR STRONGER STORMS. EXPECT MOST OF THE ACTIVITY TO EXIT EAST BETWEEN 21-00Z...WITH A CLEARING TREND IN THE EVENING AS HIGH PRESSURE OVER THE PLAINS STARTS TO INFLUENCE THE LOCAL AREA. PRESSURE GRADIENT STAYS RELATIVELY TIGHT THOUGH...SO THERE MIGHT NOT BE A LOT OF DROP OFF IN WINDS SAT NIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... 246 AM CDT SAT AUG 4 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS PUEBLO CO
408 AM MDT SAT AUG 4 2012 .SHORT TERM... (TODAY AND TONIGHT) COLD FRONT CURRENTLY RACING THROUGH SOUTHEAST CO AND SHOULD REACH THE SOUTHERN BORDER BY 12-13Z. WIND GUSTS BEHIND THE FRONT HAVE BEEN IN THE 40-45 KT RANGE SO FAR THIS MORNING ACROSS PORTIONS OF SOUTHERN EL PASO AND PUEBLO COUNTIES. HRRR AND LOCAL 4KM WRF SHOW POTENTIAL FOR SOME ISOLATED SHOWERS TO DEVELOP BEHIND THE FRONT ACROSS THE SOUTHEAST PLAINS EARLY THIS MORNING AS IT ENCOUNTERS HIGHER DEW POINTS ACROSS THE FAR SOUTHEAST PLAINS. WILL MAINTAIN SOME 20 POPS THROUGH 15Z FOR THE FAR SOUTHERN AND EASTERN PORTIONS OF THE AREA. OTHERWISE...REMAINDER OF THE AREA SHOULD REMAIN DRY THROUGH THE EARLY MORNING HOURS. NAM ALSO DEVELOPS SOME MVFR STRATUS EARLY THIS MORNING ALONG THE CREST OF THE PALMER DIVIDE. GUSTY NORTH WINDS WILL CONTINUE THROUGH THE MORNING BEFORE SWINGING AROUND FROM THE EAST TO SOUTHEAST DURING THE AFTERNOON ACROSS THE PLAINS. DEW POINTS BEHIND THE FRONT DROP INTO THE 40S BY AFTERNOON...AND MODEL SOUNDINGS SHOW A STOUT CAPPING INVERSION WHICH SHOULD HINDER AFTERNOON THUNDERSTORM DEVELOPMENT ACROSS THE PLAINS. MEANWHILE...MONSOON PLUME HAS BEEN SHUNTED EVEN FARTHER SOUTH TODAY...WITH PRECIP WATERS ABOVE 100% OF NORMAL NOW PUSHED TO ALONG THE SRN CO BORDER AND INTO NEW MEXICO. STILL ENOUGH MOISTURE PRESENT FOR ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE SOUTHERN MTS TODAY...THOUGH GREATEST COVERAGE SHOULD BE NEAR THE NM BORDER. HAVE DECREASED POPS FARTHER NORTH WHERE SOUNDINGS LOOK QUITE DRY. LATEST MODELS ARE TRENDING PRECIPITATION SOUTHWARD TO ALONG THE FRONTAL BOUNDARY ACROSS NORTHEAST NEW MEXICO...AND HAVE CUT BACK POPS TO ISOLATED ALONG THE NRN SLOPES OF THE RATON RIDGE. GUIDANCE TEMPERATURES TODAY STILL SHOW QUITE A DISCREPANCY...WITH MAV RUNNING AROUND 5 TO 10 DEGREES COOLER THAN MET ACROSS THE PLAINS. HAVE GENERALLY SPLIT THE DIFFERENCE FOR NOW. MTN AREAS SHOULD SEE TEMPS SIMILAR TO A DEGREE OR TWO COOLER THAN THOSE OF YESTERDAY. TONIGHT...CONVECTION SHOULD DIMINISH QUICKLY THIS EVENING WITH LOSS OF HEATING. WILL MAINTAIN SOME ISOLATED POPS ACROSS THE SRN MTS UNTIL 06Z...THEN REMOVE POPS THERE-AFTER. MIN TEMPS TONIGHT SHOULD BE COOLER ACROSS THE PLAINS AND HAVE CUT THEM BACK A COUPLE DEGREES. -KT .LONG TERM... (SUNDAY THROUGH SATURDAY) THE EXTENDED FORECAST WILL BE DOMINATED BY HIGH PRESSURE OVER THE FOUR CORNERS REGION WITH VERY HOT CONDITIONS FOR THE LOWER ELEVATIONS AND MOUNTAIN THUNDERSTORMS. HIGH PRESSURE BEGINS TO BUILD NORTHWARD SUNDAY MORNING AS AN UPPER LEVEL TROUGH MOVES EAST ACROSS THE GREAT LAKES. A WEAK DISTURBANCE CAUGHT UNDER THE BUILDING HIGH WILL DRIFT NEAR THE COLORADO NEW MEXICO BORDER AND HELP GENERATE SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER THE SAN JUAN AND SOUTHERN SANGRE DE CRISTO RANGES. MODELS KEEP THIS ACTIVITY GOING THROUGH SUNDAY NIGHT INTO MONDAY MORNING. HIGH PRESSURE CONTINUES TO BUILD ACROSS THE REGION ON MONDAY WITH AFTERNOON THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS. FLOW ALOFT WILL REMAIN NORTHWESTERLY AROUND THE STRENGTHENING HIGH WHICH WILL HELP PUSH CONVECTION INTO THE I-25 CORRIDOR. THIS ACTIVITY IS FORECAST TO DIMINISH THROUGH THE EVENING HOURS. TEMPERATURES ON SUNDAY WILL START TO WARM WITH UPPER 80S TO LOWER 90S FOR THE PLAINS. BY MONDAY...HIGHS WILL BE PUSHING INTO THE UPPER 90S TO LOWER 100S FOR THE PLAINS. TUESDAY THROUGH SATURDAY...HIGH PRESSURE WILL ANCHOR ITSELF OVER THE FOUR CORNERS AREA AND DOMINATE THE WEATHER. THIS WILL HELP KEEP TEMPERATURES WARM THROUGH THE EXTENDED WITH UPPER 90S TO LOWER 100S EXPECTED FOR THE PLAINS. WITH THE MONSOON MOISTURE TAP WELL TO THE WEST AND DRIER AIR ACROSS COLORADO...THUNDERSTORM COVERAGE IS FORECAST TO BE MINIMAL AND DIURNALLY DRIVEN. WITH WEAK FLOW ALOFT...ANY THUNDERSTORMS THAT DO DEVELOP WILL REMAIN ANCHORED TO THE MOUNTAINS. MOZLEY && .AVIATION... MVFR STRATUS WILL DEVELOP ALONG THE CREST OF THE PALMER DIVIDE AND NORTH SIDE OF THE RATON RIDGE THIS MORNING. NORTH WINDS GUSTING TO 30-40 KTS WILL CONTINUE AT KPUB AND KCOS THROUGH 12-15Z BEFORE WINDS DECREASE AND SWING AROUND FROM THE EAST TO SOUTHEAST BY THE AFTERNOON. STRATUS SHOULD DISSIPATE BY LATE MORNING...AND STAY PREDOMINANTLY TO THE NORTH OF THE KCOS TERMINAL. ISOLATED TO SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS DURING THE AFTERNOON...THOUGH SHOULD DISSIPATE AS THEY MOVE OFF THE MTS AND SHOULD NOT IMPACT KCOS AND KPUB. KALS WILL HAVE A SLIGHTLY BETTER CHANCE OF SEEING A PASSING -TSRA IN THE AFTERNOON...THOUGH ODDS TOO LOW AT THIS POINT TO INCLUDE IN TAF AS LOW LEVEL MOISTURE SHOULD BE LESS TODAY. -TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY AFTER SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH THE NIGHT. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31/88
AREA FORECAST DISCUSSION
NWS MIAMI FL
724 AM EDT SAT AUG 4 2012 .AVIATION... A TROPICAL WAVE BETWEEN THE BAHAMAS AND MAINLAND...WHICH EXTENDS SW OVER N CUBA...WILL SLOWLY MOVE W THROUGH THE PERIOD. THIS FEATURE WILL SLOWLY MOVE OVER THE SE FLA COAST THIS MORNING AND WILL MOVE ACROSS S FLA THROUGH THE DAY. SCATTERED SHRA WITH ISOLD TSRA AT THIS TIME WELL E IN THE ATLC BUT EXPECT SHRA TO DEVELOP BY LATE MORNING AND POSSIBLE TSRA AS EARLY AS 16Z ALONG THE E COAST. WILL HAVE VCSH IN E COAST TERMINALS INITIALLY BUT POSSIBLE TSRA BY 16Z. ANY TSRA THAT DEVELOP WILL MOVE SLOWLY SO HEAVY RA AND POSSIBLE MVFR CIG/VSBY WILL BE POSSIBLE. MODEL GUIDANCE AT THIS TIME DOES NOT INDICATE MVFR CIG/VSBY AND MODELS PROJECT THE BULK OF THE SHRA/TSRA TO THE E OF THE WAVE MOVING N ALONG THE FLA E COAST. HEATING OF THE DAY WILL BE THE MAIN INPUT TO PRECIPITATION. SFC WINDS ENE < 10 KNOTS BECOMING ESE 10 TO 15 KNOTS AS THE WAVE MOVES PAST ANY ONE TERMINAL LATER TODAY. && .PREV DISCUSSION... /ISSUED 358 AM EDT SAT AUG 4 2012/ ..LOCALLY HEAVY RAINFALL POSSIBLE TODAY... ..MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES... DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH? A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO 50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS), DURATION AND AMOUNT IS OF HIGH UNCERTAINTY. AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT NIGHT. THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL YESTERDAY. TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI. MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE NEEDED AT THIS TIME. FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN TYPICALLY HIGH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 78 89 79 / 70 50 60 50 FORT LAUDERDALE 88 80 89 79 / 70 50 60 50 MIAMI 89 78 89 79 / 70 50 60 50 NAPLES 91 76 92 77 / 50 30 50 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
936 AM EDT SAT AUG 04 2012 .Mesoscale Discussion... Issued at 936 AM EDT Sat Aug 4 2012 With the exception of a slight uptick in intensity over the southern Blue Grass, storms in the rest of the LMK CWA are continuing to fall apart this morning. Once the Blue Grass convection heads east/weakens, we should see a relative lull in the precip before scattered storms are able to fire up in the warm unstable air this afternoon. In the grids we have decreased PoPs for the late morning hours before bringing them back up in the afternoon. Have been keeping an eye on the convection south of St Louis this morning. HRRR has had the best handle on this activity, and that model dives the thunderstorms to the SSE through western Kentucky, west Tennessee, and into Alabama. So far this is being borne out on regional radar loops. However, while that path would be to the west of the LMK CWA, model data are hinting at new convection possibly firing up on outflow heading east from the Mississippi Valley storms into central Kentucky and, to a lesser extent, southern Indiana. This further supports chance PoPs for the afternoon hours. We have cut high temps in the southeast where morning clouds and showers will linger the longest. Have left temperatures alone in the rest of the area where more sunshine is occurring or expected. May flirt with Heat Advisory criteria briefly this afternoon in the far west, thanks more to dew points in the lower and middle 70s than the air temperature, but with cirrus shield moving in from the west and the brevity of any indices AOA 105, will stick with the SPS for now. Issued at 810 AM EDT Sat Aug 4 2012 Storms have been on the decrease over the past couple of hours as the NLLJ weakens. However, some strong storms remain, especially INVOF Elizabethtown and Hodgenville. Torrential rainfall is occurring in these low centroid storms thanks to very high precipitation efficiency in a soupy air mass. Have upped PoPs to categorical where it is currently raining as well as downstream to the east. Have also introduced "heavy rain" wording -- the Elizabethtown KY Mesonet site reported 0.31 inches of rain in just 5 minutes. Have also greatly increased QPF numbers, to around an inch and a half INVOF the Hardin/LaRue storms, and 0.50-0.75" downstream into the Blue Grass. && .Short Term (Today through Sunday)... Issued at 325 AM EDT Sat Aug 4 2012 A lot to talk about in the short-term period. To start off with, a weak low-level jet is setting up early this morning across central Kentucky. This is aiding in moisture advection and lift. A few showers and thunderstorms have developed along the KY-TN border and continue to push northeast into central Kentucky. Additional development is possible, but overall areal coverage should be limited. These, mainly isolated, showers and thunderstorms will dissipate as the low-level jet relaxes shortly after sunrise. We should then be mainly dry until the afternoon hours, but an isolated shower/storm cannot be ruled out given the moist air mass. For the rest of today, there is a weak wave across portions of Missouri propagating eastward early this morning. It seems this will initiate convection across eastern Missouri a little later, which will push east into our area later this afternoon. This should act to increase our thunderstorm potential and coverage throughout the day, particularly with diurnal heating. Will have to see if this solution pans out, but either way, convection should fire this afternoon just due to heating, with highs topping out in the lower 90s. Heat indices will top out in mid and upper 90s across the east, with 100 to around 105 expected along and west of I-65. Still expecting convection to decrease as the sun sets this evening. Activity should ramp up again, mainly across southern Indiana and north-central Kentucky as a low-level jet increases ahead of our approaching cold front. Convection associated with this feature appears to dissipate a bit shortly after sunrise as well, with the loss of the low-level jet. However, convection will increase in coverage throughout the day Sunday, mainly across central Kentucky and points south/east, as the cold front pushes southeast through the forecast area during peak heating. Here is a caveat. The latest 4km NAM indicates convection along the cold front should initiate late this afternoon/early evening across portions of northern Illinois and central Missouri. This model generates a good cold pool, which drops the convection quickly southeast and into portions of southern Indiana shortly after midnight. This line appears to be in a weakening stage, but arrives faster than most models are predicting. This solution also continues pushing the outflow boundary southeast where additional storm development occurs across central and south-central Kentucky before sunrise Sunday. If this pans out, most convection will be overnight, with the Sunday afternoon storms having less coverage and being confined to the frontal boundary forcing. Given the uncertainty amongst models and this seeming to be an outlier, will not jump completely on this solution, but this will be key to watch as the day unfolds. This model has shown some positive results over the last few days. Otherwise, models continue to indicate total PWs of almost 2 inches for today, which increases to just over 2 inches for Sunday. High temperatures Sunday should reach the mid and upper 80s, with a few locations perhaps touching 90 degrees. This will yield CAPE values in the 2000-3000 J/kg range, especially across southern and eastern portions of the forecast area during Sunday afternoon. Shear appears to be maximized in the afternoon as well, with 0-6km bulk shear values in the 20-30 knot range. Damaging wind, very heavy rainfall, and some hail will be the main threats. Given the recent rainfall across the area and the increase in total moisture through Sunday, there could be localized flash flooding concerns. .Long Term (Sunday Night through Friday)... Issued at 304 AM EDT Sat Aug 4 2012 The first forecast challenge in the long term will be the timing of Sunday`s cold front pushing through the region Sun night/early Mon. Models vary in exactly when the front and unstable airmass will push south of our area. Because this weather system is on in the stronger side, will go with a more progressive soln closer to the 0Z GFS and GFS ensembles. This would push the front through early Mon morning and stall it out just to our south over TN during the day Mon. So, with this timing in mind, strong to severe storms with damaging winds, torrential rainfall, and cloud to ground lightning may linger east of I-65 early Sun night. After midnight, expect storms to decrease in strength and be more confined to the Lake Cumberland region. For Mon, will keep 20-30% chance POPs in the southeast CWA which may or may not pan out depending on the exact location of the front and left over showers/t-storms. Temps will be tricky to nail down Sun night and Mon depending on the exact front position and clearing of clouds from NW to SE. Will go with a decent gradient of highs/lows for the Sun night/Mon time period. Looks like lows Sun night should bottom out in the mid 60s north to lower 70s south. Highs on Monday should range from the upper 80s to around 90 north to lower 80s southeast. Sfc high pressure will settle in for Tues and most of Wed keeping conditions dry with low humidity. Seasonal temps will prevail in the upper 80s and lower 90s for highs both days. With mostly clear skies, low temps will bottom out in the 60s. By late Wed, the left over boundary from early in the week, will transition to more of an inverted trough forecast to move back north into our region by Thurs. Along with this weak boundary, an upper low will dive south into the Great Lakes region with an upper level shortwave around its periphery making its way into the Ohio Valley. Therefore, will continue 30% POPs for Thurs. For Fri and into the weekend, long range models diverge on how far south the upper low will travel and to what degree of strength it will have. At this point, at least some troughing and a cold front look possible toward Thurs night/Fri time frame. Thus will keep low POPs going with cooler temps (mid 80s) in store for the weekend. && .Aviation (12Z TAF Issuance)... Issued at 648 AM EDT Sat Aug 4 2012 Isolated to scattered showers/storms around BWG and LEX early this morning will continue to push northeast as a weak low-level jet remains overhead. Isolated cells are moving away from BWG, while thunderstorms will be in the vicinity of LEX for a little longer this morning. Could see cigs drop at LEX too if the storms move directly overhead. Storm coverage should decrease as the low-level jet relaxes. Winds will become south-southwesterly and increase between 10 and 15 mph, with gusts 20-25 mph by this afternoon. Diurnal Cu will develop once again, with storm chances increasing during peak heating. A weak wave across Missouri this morning is initiating convection across the mid Mississippi Valley. This activity should push east, which could mean slightly greater areal storm coverage later this afternoon. Will continue VCTS and a CB group in the TAFs for this. Overnight, another low-level jet will strengthen overhead, with borderline LLWS setting up across the area starting around 06Z. At the same time, storms could develop during the pre-dawn hours along the Ohio River. At this time, will not mention LLWS, but will include VCTS at SDF for the early morning storm chance. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. $$ Mesoscale........13 Short Term.......MJP Long Term........AMS Aviation.........MJP
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
933 AM CDT SAT AUG 4 2012 .UPDATE... SPREAD SCATTERED SHOWERS FURTHER WEST AND DE-EMPHASIZED THUNDER ACROSS THE AREA THIS MORNING. DECREASED WINDS A LITTLE THIS MORNING. && .SHORT TERM... THE ACTUAL FRONT IS MOVING THROUGH THE DULUTH AREA MID-MORNING THIS MORNING. IT IS BECOMING A STRONG FRONT...WITH THE UPPER FLOW AND THERMAL WIND LINING UP MORE AND MORE PARALLEL TO IT. THIS SLOWS DOWN ITS FORWARD PROGRESS AND INCREASES MOISTURE AND CAUSES PRECIPITATION TO FILL IN BEHIND IT. BRIEF SURFACE RIDGING BEHIND THE FRONT IS FOLLOWED BY THE TROUGH THAT REFLECTS FALLING HEIGHTS ALOFT. WE LEFT IN SHOWERS AND DID NOT DE-EMPHASIZE THUNDERSTORMS THIS AFTERNOON INTO THE EVENING...THUNDERSTORMS WILL BE SHALLOW... BRIEF...AND SPOTTY IN DISTRIBUTION. SOUTHWEST WINDS WILL COME UP A LITTLE LATER...AS THE SECOND TROUGH APPROACHES...AND SLOWLY VEER. .PREV DISCUSSION... /ISSUED 631 AM CDT SAT AUG 4 2012/ AVIATION...12Z TAFS. FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z. PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/ SHORT TERM...THROUGH SUNDAY. CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3 HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST. THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF HIGHEST MOISTURE/AND NEAREST THE UPPER LOW. IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN. TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY. AVIATION...06Z ISSUANCE WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z. && .POINT TEMPS/POPS... DLH 77 55 75 55 / 40 20 10 0 INL 75 47 76 56 / 60 40 10 0 BRD 76 55 76 55 / 20 10 10 0 HYR 79 54 75 53 / 50 10 10 0 ASX 81 58 76 56 / 50 10 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...EOM LONG TERM....GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS DULUTH MN
631 AM CDT SAT AUG 4 2012 .AVIATION...12Z TAFS. FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z. && .PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/ SHORT TERM...THROUGH SUNDAY. CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3 HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST. THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF HIGHEST MOISTURE/AND NEAREST THE UPPER LOW. IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN. TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY. AVIATION...06Z ISSUANCE WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z. && .POINT TEMPS/POPS... DLH 77 55 75 55 / 20 20 10 0 INL 75 47 76 56 / 60 40 10 0 BRD 76 55 76 55 / 20 10 10 0 HYR 79 54 75 53 / 40 10 10 0 ASX 81 58 76 56 / 40 10 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ AVIATION...GSF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1030 AM EDT SAT AUG 4 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 1030 AM SATURDAY...DEEP TROPICAL SOUTHEASTERLY FLOW DEVELOPING ACROSS THE REGION TODAY WHILE MID LEVEL LOW OVER THE REGION BOTH LIFTS OUT TO THE NORTH AND WEAKENS. THIS LEAVES THE COASTAL CAROLINAS WITH LITTLE IN THE WAY OF FORCING FOR PRECIP OTHER THAN FRICTIONAL CONVERGENCE ALONG THE COAST. 12Z WRF SHOWING JUST A FEW TROPICAL SHOWERS MATERIALIZING OVER NC COASTAL ZONES. HRRR RUNS GO BACK AND FORTH BETWEEN SHOWING MINIMAL COVERAGE AND NO COVERAGE AT ALL. AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM. && .SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... AS OF 12Z...ANY LIGHT FOG AROUND WILL QUICKLY DISSIPATE BY 1230Z. FAIRLY TYPICAL SUMMER DAY WITH TCU`S ALREADY LURKING OFFSHORE. LOOK FOR ISOLATED/SCATTERED CONVECTION ALONG THE SEA BREEZE BOUNDARY...BEGINNING NEAR THE COAST AROUND 16Z. LFC`S ARE THE LOWEST IN PENDER COUNTY...SO THAT MAY BE THE INITIATION AREA FOR CONVECTION. SOUTHEAST FLOW THROUGH 500 MB WILL GIVE US A TROPICAL LIKE ENVIRONMENT WITH LOW BASED CU AND GREAT VISIBILITY. ANY ONGOING CONVECTION LATE THIS AFTERNOON WILL LIKELY DISSIPATE BY 22-23Z FOR DIURNAL REASONS. LIGHT WINDS OVERNIGHT WITH POSSIBLE LIGHT FOG A COUPLE OF HOURS BEFORE SUNRISE. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM SATURDAY...SEAS JUST 2.5 FT ALL THE WAY OUT AT BUOY 41013 WITH DOMINANT PERIOD 8-9 SECONDS INDICATIVE OF SWELL ENERGY. JUST A SUBLET CHANGE TO SEAS FORECAST FROM A STRAIGHT 3 FT TO THAT OF 2 TO 3 FT AS A THOUSAND MILE SOUTHEAST FETCH CONTINUES INTO THE CAROLINAS. AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT... WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE CLOSER PROXIMITY OF THE INVERTED SFC TROF. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE RULED OUT EARLY ACROSS THE OUTER WATERS. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...MBB SHORT TERM...SHK LONG TERM...SHK AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
716 AM EDT SAT AUG 4 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM. && .SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... AS OF 12Z...ANY LIGHT FOG AROUND WILL QUICKLY DISSIPATE BY 1230Z. FAIRLY TYPICAL SUMMER DAY WITH TCU`S ALREADY LURKING OFFSHORE. LOOK FOR ISOLATED/SCATTERED CONVECTION ALONG THE SEA BREEZE BOUNDARY...BEGINNING NEAR THE COAST AROUND 16Z. LFC`S ARE THE LOWEST IN PENDER COUNTY...SO THAT MAY BE THE INITIATION AREA FOR CONVECTION. SOUTHEAST FLOW THROUGH 500 MB WILL GIVE US A TROPICAL LIKE ENVIRONMENT WITH LOW BASED CU AND GREAT VISIBILITY. ANY ONGOING CONVECTION LATE THIS AFTERNOON WILL LIKELY DISSIPATE BY 22-23Z FOR DIURNAL REASONS. LIGHT WINDS OVERNIGHT WITH POSSIBLE LIGHT FOG A COUPLE OF HOURS BEFORE SUNRISE. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT... WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE CLOSER PROXIMITY OF THE INVERTED SFC TROF. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE RULED OUT EARLY ACROSS THE OUTER WATERS. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...DCH SHORT TERM...SHK LONG TERM...SHK AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
701 AM EDT SAT AUG 4 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM. && .SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...EXPECT MVFR AND/OR IFR VSBYS FROM BR/FG DURING THE 08Z-13Z TIME FRAME. FLO AND/OR LBT TERMINALS WILL HAVE THE GREATER POTENTIAL TO OBSERVE PREVAILING BR/FG...WHEREAS THE COASTAL TERMINALS WILL INDICATE TEMPO MVFR VSBYS. COULD OBSERVE A SUB-1000 FT CLOUD DECK ALONG THE COASTAL TERMS WITHIN A 4 HR WINDOW SURROUNDING SUNRISE. BY MID-MORNING...ANY RESIDUAL BR SHOULD DISSIPATE...LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY. THE PROB OF THUNDERSTORMS REMAINS ON THE LOW SIDE...BUT ENOUGH CONFIDENCE TO MENTION VCTS AT ALL TERMINALS FROM MIDDAY THROUGH EARLY THIS EVENING. PREVAILING SE-S WINDS AT 5 TO 10 KT EXPECTED...UP TO 15 KT AT THE COASTAL TERMINALS. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT... WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE CLOSER PROXIMITY OF THE INVERTED SFC TROF. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE RULED OUT EARLY ACROSS THE OUTER WATERS. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...DCH SHORT TERM...SHK LONG TERM...SHK AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
656 AM EDT SAT AUG 4 2012 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN FROM THE EAST THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND TUESDAY BUT WILL STALL AND WEAKEN WEST OF THE AREA WEDNESDAY THROUGH LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 650 AM SATURDAY...PER EARLIER RUNS OF THE RAP MODEL AND THE 06Z NAM...SCATTERED SHOWERS AND A FEW TSTMS HAVE DEVELOPED IN AN AREA OF SURFACE MOISTURE CONVERGENCE AND INSTABILITY NEAR THE COAST AND HAVE MOVED INLAND. HAVE RAISED POPS TO CHC OVER ROUGHLY THE EASTERN THIRD OR SO OF THE CWA. RAP INDICATES THESE SHOWERS WILL AROUND FOR ALOT OF MORNING...WITH ADDITIONAL ISOLATED SHOWERS AND TSTMS THIS AFTERNOON WITH THE SEA BREEZE. NO CHANGES TO FORECAST TEMPERATURES MAINLY IN THE UPPER 80S TO AROUND 90 TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... AS OF 3 AM SATURDAY...THE COMBINATION OF A MOIST ONSHORE FLOW AND SOME WEAK MID-LEVEL VORTICITY MAY LEAD TO A REPEAT OF THIS MORNING WITH A FEW SHOWERS ALONG THE COAST IN THE OVERNIGHT HOURS AND WILL HAVE A SLIGHT CHC POP. OTHERWISE...A PARTLY CLOUDY WARM AND MUGGY NIGHT WITH MIN TEMPS IN THE 73 TO 78 DEGREE RANGE. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 330 AM SATURDAY...LONG TERM MODELS STILL IN GENERALLY GOOD AGREEMENT ON SYNOPTIC REGIME THROUGH THE COMING WEEK. BERMUDA HIGH WILL REMAIN SOUTH AND EAST OF THE REGION...WHILE BROAD TROUGH EXISTS ACROSS EASTERN HALF OF CONUS. FLOW WILL REMAIN SOUTHWESTERLY... SUPPLYING E NC WITH WARM AND HUMID CONDITIONS...WHILE WEAK SHORTWAVES AND STATIONARY FRONT ACROSS CENTRAL NC BRINGS CHANCES FOR CONVECTIVE ACTIVITY EACH DAY. BEST CHANCES FOR THUNDERSTORMS WILL BE IN THE AFTERNOON HOURS...THOUGH RAIN CHANCES MAY LINGER THROUGH THE EVENING HOURS. BEST CHANCES FOR WIDESPREAD RAIN AND STORMS WILL BE AROUND MID TO LATE WEEK TIME FRAME. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... /SHORT TERM TODAY AND TONIGHT/... AS OF 7 AM SAT...SOME MVFR FOG HAS DEVELOPED AT ALL OF THE TAF SITES AND VSBY HAS BEEN BOUNCING UP AND DOWN FOR THE PAST COUPLE OF HOURS. THIS FOG SHOULD DISSIPATE BY ABOUT 13Z WITH ANOTHER ROUND OF ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON. SIMILAR PATTERN EXPECTED TONIGHT WITH A FEW SHOWERS DEVELOPING NEAR THE COAST...BUT OVERALL MVFR CONDITIONS EXPECTED WITH SOME PATCHY FOG TOWARD MORNING ON SUNDAY. /LONG TERM SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM SATURDAY...MAINLY VFR CONDITIONS WILL PREVAIL...THOUGH AS IS THE CASE MOST EVENING...SOME REDUCTIONS TO MVFR/IFR POSSIBLE LATE AS RADIATION FOG/LOW STRATUS DEVELOPS...ESP IN AREAS THAT RECEIVE RAINFALL. SCT MAINLY AFTERNOON THUNDERSTORMS WILL BRING TEMPO REDUCTIONS IN VSBYS THROUGH THE COMING WEEK. && .MARINE... /SHORT TERM TODAY AND TONIGHT/... AS OF 7 AM SATURDAY...CURRENT BUOY OBSERVATIONS CONTINUE TO INDICATE S/SW WINDS OF 12 KNOTS OR LESS WITH SEAS 2 TO 3 FEET WITH A 7 TO 8 SECOND SWELL COMPONENT. A FEW SHOWERS MOVING ALONG THE COAST MAY BRIEFLY CAUSE SOME GUSTINESS TO ABOUT 18 KNOTS OR SO. S/SW WINDS WILL CONTINUE TO CIRCULATE AROUND HIGH PRESSURE TO THE EAST TODAY AND TONIGHT WITH FRONTAL BOUNDARY REMAINING WELL OFF TO THE WEST IN THE OHIO VALLEY. THIS WILL LEAD TO S/SW WINDS 10 TO 15 KNOTS WITH SEAS 2 TO 3 FEET THROUGH TONIGHT. /LONG TERM SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM SATURDAY...SOUTHWEST FLOW WILL CONTINUE THROUGH THE LONG TERM...WITH WINDS GENERALLY 10 TO 15 KNOTS OVER THE WATERS... AND AROUND 10 KT OVER THE SOUNDS. SEAS WILL REMAIN IN THE 3 TO 4 FT RANGE ACROSS OUTER WATERS WITH 2 TO 3 FEET NEARSHORE. THERE WILL BE CHANCES FOR THUNDERSHOWERS THROUGH THE COMING WEEK AS A COOL FRONT AND TROUGH SAGS INTO CENTRAL AND EASTERN NC AND STALLS OUT NEARBY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...CTC NEAR TERM...CTC SHORT TERM...CTC LONG TERM...TL AVIATION...CTC/TL MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
637 AM EDT SAT AUG 4 2012 .SYNOPSIS... SCATTERED SHOWERS AND A POSSIBLE THUNDERSTORM WILL OCCUR TODAY AS LOW LEVEL MOISTURE INCREASES OVER THE AREA. MORE ACTIVE WEATHER WILL BEGIN WHEN A STRONG COLD FRONT WILL INTERACT WITH AN UPPER LEVEL DISTURBANCE TO BRING SHOWERS AND THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY. THE FRONT WILL PUSH EAST OF THE AREA SUNDAY NIGHT INTO MONDAY...ALLOWING HIGH PRESSURE AND DRIER AIR TO BUILD INTO THE AREA. NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES CAN THEN BE EXPECTED DURING THE FIRST PART OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... INCREASING SHOWER ACTIVITY IN AMPLE LL MOISTURE AND INCREASING INSTABILITY THROUGH TODAY. HRRR SEEMS TO HAVE A HANDLE ON CURRENT ACTIVITY. COVERAGE NOT EXPECTED TO BE WIDESPREAD...SO HAVE OPTED FOR CHANCE SHRA WITH ISOLD THUNDER THIS MORNING...AND SCT TSTMS THIS AFTERNOON. WITH LACK OF ORGANIZED SURFACE OR UPPER AIR FEATURE...EXPECTATION IS STILL THAT OF UNORGANIZED CONVECTION. WITH LOW LEVEL CLOUDS...HAVE BROUGHT HIGH TEMPERATURES DOWN IN ESPECIALLY THE SOUTHERN HALF OF THE AREA. WITH EXPECTANT CLOUD COVER TODAY...NO HEAT ADVISORY CRITERIA MET WITH SLIGHTLY LOWERED TEMPERATURES. WILL STILL KEEP MENTION IN THE HWO AS VALUES DO APPROACH 100 DEGREES. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... SOME TIMING DIFFERENCES WITH THE MAIN EXPECTATION OF CONVECTION AND SUBSEQUENT FRONTAL PASSAGE...WITH THE GFS A LITTLE FASTER THAN BOTH THE NAM AND ECMWF. HAVE OPTED FOR THE TIMING OF THE LATTER TWO MODELS. EARLY PART OF SAT EVENING CONTINUES FAIRLY DISORGANIZED CONVECTION...WITH THE MORE ORGANIZED DYNAMICALLY DRIVEN ACTIVITY TO BEGIN AFTER 00-06Z TIMEFRAME IN THE ILN AREA. AS THE S/WV DIGS INTO THE UPR MS VALLEY AND APPROACHING WESTERN IN...SOUTHERLY LL FLOW CONTINUES TO PUMP VERY MOIST AIR INTO THE REGION. IN ADDITION TO CONCERN FOR SEVERE WITH THE PRE FRONTAL ACTIVITY...THERE STILL IS POTENTIAL FOR MCS AHEAD OF THIS WITH THE DEVELOPMENT OF A 40 KT+ LLJ (SLIGHTLY WEAKER IN THE ECMWF BUT STILL ENHANCED) AND SIGNIFICANT MOISTURE TRANSPORT. WHILE THERE ISNT STRONG EVIDENCE OF BACK BUILDING STORMS...WARM CLOUD DEPTHS OF NEAR 4500M AND PW VALUES BETWEEN 2.25-2.5 INCHES WILL MAKE FOR POTENTIAL OF VERY HIGH RAINFALL RATES. WITH ENHANCED LL JET AND INCREASING DYNAMICS IN ADDITION TO RESPECTIBLE ML CAPE...POTENTIAL FOR DAMAGING WINDS...WTH POSSIBILITY OF LARGE HAIL. FIRST SHOT OF CONVECTION/POTENTIAL MCS TO EXIT THE AREA BEFORE IN THE 15Z TIMEFRAME...AND THEN STILL SEVERE POTENTIAL AHEAD OF THE FRONT IN THE AFTERNOON DEPENDING ON HOW WORKED OVER THE AIRMASS IS AFTER PASSAGE OF MORNING CONVECTION. HAVE SLOWED DOWN THE TIMING OF THIS CONVECTION TO NOT EXIT THE AREA UNTIL AFTER 00Z...WTH PRECIP LINGERING LONGEST IN THE SE. WITH AMPLE CLOUDS HAVE CONTINUED TO KEEP TEMPS BELOW 90 FOR SUNDAY. FOR SUN NIGHT SKIES TO BEGIN CLEARING IN THE WEST WITH TEMPS DROPPING TO UPR 50S HERE RANGING TO UP 60S SOUTHAST. DRY CONDITIONS AND NEAR NORMAL TEMPERATURES FOR MONDAY AND TUE. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... THE COLD FRONT AND ALL ASSOCIATED PRECIPITATION WILL SHIFT OF TO OUR EAST MONDAY MORNING AS LOW LEVEL RIDGING BUILDS ACROSS THE REGION. SKIES WILL BE MOSTLY CLEAR DURING THE DAY WITH CONTINUED COLD ADVECTION KEEPING TEMPERATURES NEAR...TO JUST BELOW SEASONABLE VALUES DURING THE DAY. THE HIGH PRESSURE AREA WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH TUESDAY NIGHT. THIS WILL KEEP US DRY WITH LIGHT WINDS AND ONLY A FEW PASSING CLOUDS. TEMPERATURES MONDAY NIGHT WILL BE THE COOLEST OF THE WEEK...WITH FORECAST LOWS RANGING FROM THE LOW 60S ACROSS THE SOUTH...TO THE MID 50S ACROSS THE NORTHEAST. BY WEDNESDAY...TEMPERATURES ALOFT BEGIN TO WARM AS A SHORTWAVE OVER THE PLAINS PUSHES PART THEIR VERY WARM AIRMASS TOWARD THE OHIO VALLEY. THIS WILL BRING A REBOUND OF TEMPERATURES BACK TO ABOVE SEASONABLE VALUES FOR THE MIDDLE OF THE WEEK. THE SHORTWAVE WILL THEN SLIDE EASTWARD...BRINGING INCREASING CHANCES FOR PRECIPITATION TOWARD THE END OF THE WEEK. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... SCATTERED CONVECTION WILL BE ONGOING TODAY WITH GENERALLY VFR CONDITIONS OUTSIDE OF THE PASSING SHOWERS. WINDS WILL PICK UP THIS AFTERNOON AND A COLD FRONT WILL CROSS THE REGION AROUND THIS TIME TOMORROW. EXPECT WIND SHIFT AT DAYBREAK TOMORROW WITH MORE PREVALENT THUNDERSTORMS ALONG AND AHEAD OF IT AS THE LOW LEVEL MOISTURE TRANSPORT KICKS IN OVERNIGHT. .OUTLOOK...SHOWERS AND THUNDERSTORMS WILL BECOME MORE LIKELY TONIGHT AND SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...JDR NEAR TERM...JDR SHORT TERM...JDR LONG TERM...LATTO AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1053 AM EDT SAT AUG 4 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR BUILDS IN FOR EARLY NEXT WEEK. OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO 8 DAYS. && .NEAR TERM /THROUGH TONIGHT/... MOIST SOUTHWESTERLY FLOW WILL CONTINUE TO INCREASE AHEAD OF A COLD FRONT ENTERING THE GR LAKES. THIS WILL PROVIDE INCREASING CHANCES FOR SHOWERS/STORMS...ESPECIALLY THIS AFTERNOON AND EVENING. MUCH OF THE MORNING AND POSSIBLY EVEN INTO THE EARLY AFTERNOON HOURS SHOULD STAY PARTLY TO MOSTLY SUNNY AND DRY BEFORE WE REACH CONVECTIVE TEMPS AND START TO COOK UP SCATTERED SHOWERS AND STORMS. SREF POPS FOR LATER THIS AFTERNOON AND EVENING RANGE FROM CHANCE OVER THE NORTH TO CATEGORICAL OVER THE SOUTH...PROBABLY TYPICALLY OVERDONE BY THE SREF. CURRENT HRRR SHOWING PRECIPITATION FORMING OVER THE LAUREL HIGHLANDS BY 18Z. THE SREF AND GEFS HAVE INCREASED PWAT ANOMALIES OVER THE AREA. COUPLE THIS WITH TEMPERATURES IN THE UPPER 80S AND LOWER 90S...AND DECENT SOUTHEASTERLY FLOW...EXPECT DIURNAL CONVECTION THIS AFTERNOON AND THROUGH THE FIRST HALF OF THE EVENING. MODELS SOW IT SPREADING ACROSS CENTRAL PA BEFORE MOVING EASTWARD. HAVE INCREASED POPS ACCORDINGLY. THESE SHOWERS AND STORMS SHOULD BE MORE DIURNALLY DRIVEN THAN LARGER SYNOPTIC FORCING...HOWEVER A 500MB SHORTWAVE COULD ALLOW FOR A STRONG ENOUGH PV ANOMALY TO CONTINUE SHOWERS WELL INTO THE EVENING OVER THE SOUTHEAST. ANY PRECIP SHOULD BE DONE BY 06-09Z TONIGHT. PATCHY FOG AHEAD OF THE FRONT IS AGAIN A POSSIBILITY OVERNIGHT. && .SHORT TERM /SUNDAY/... SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG FOR EARLY AUG. CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE. BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME. MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION. PROBABLY NEED 90S IN THERE! && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID- MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW FALLS BELOW NORMAL STATE WIDE MONDAY. KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL. PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO GUIDANCE. TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A BIT MORE THURSDAY INTO FRIDAY. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... CONDITIONS HAVE IMPROVED TO HIGH MVFR/LOW VFR AS LAST OF THE HAZE CONTINUES TO THIN OUT. LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED LATER TODAY IN AND AROUND AN THUNDERSTORMS THAT ARE EXPECTED TO DEVELOP THIS AFTERNOON AND EARLY EVENING...FROM ABOUT 22Z THROUGH 03Z TONIGHT. OUTLOOK... .SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY SUNDAY PM AS A COLD FRONT MOVES THROUGH. .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES-WED...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/CERU/MARTIN NEAR TERM...LA CORTE/CERU/MARTIN SHORT TERM...LAMBERT/MARTIN LONG TERM...GRUMM/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
852 AM EDT SAT AUG 4 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR BUILDS IN FOR EARLY NEXT WEEK. OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO 8 DAYS. && .NEAR TERM /THROUGH TONIGHT/... STILL SOME PATCHY LOW CLOUDS AND MAINLY THIN FOG THAT WILL BURN OFF SMARTLY NOW THAT THE SUN IS UP. MOIST SOUTHWESTERLY FLOW WILL CONTINUE TO INCREASE AHEAD OF A COLD FRONT ENTERING THE GR LAKES. THIS WILL PROVIDE INCREASING CHANCES FOR SHOWERS/STORMS...ESPECIALLY THIA AFTERNOON AND EVENING. MUCH OF THE MORNING AND POSSIBLY EVEN INTO THE EARLY AFTERNOON HOURS SHOULD STAY PARTLY TO MOSTLY SUNNY AND DRY BEFORE WE REACH CONVECTIVE TEMPS AND START TO COOK UP SCATTERED SHOWERS AND STORMS. SREF POPS FOR LATER THIS AFTERNOON AND EVENING RANGE FROM CHANCE OVER THE NORTH TO CATEGORICAL OVER THE SOUTH...PROBABLY TYPICALLY OVERDONE BY THE SREF. CURRENT HRRR SHOWING PRECIPITATION FORMING OVER THE LAUREL HIGHLANDS BY 18Z. THE SREF AND GEFS HAVE INCREASED PWAT ANOMALIES OVER THE AREA. COUPLE THIS WITH TEMPERATURES IN THE UPPER 80S AND LOWER 90S...AND DECENT SOUTHEASTERLY FLOW...EXPECT DIURNAL CONVECTION THIS AFTERNOON AND THROUGH THE FIRST HALF OF THE EVENING. MODELS SOW IT SPREADING ACROSS CENTRAL PA BEFORE MOVING EASTWARD. HAVE INCREASED POPS ACCORDINGLY. THESE SHOWERS AND STORMS SHOULD BE MORE DIURNALLY DRIVEN THAN LARGER SYNOPTIC FORCING...HOWEVER A 500MB SHORTWAVE COULD ALLOW FOR A STRONG ENOUGH PV ANOMALY TO CONTINUE SHOWERS WELL INTO THE EVENING OVER THE SOUTHEAST. ANY PRECIP SHOULD BE DONE BY 06-09Z TONIGHT. PATCHY FOG AHEAD OF THE FRONT IS AGAIN A POSSIBILITY OVERNIGHT. && .SHORT TERM /SUNDAY/... SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG FOR EARLY AUG. CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE. BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME. MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION. PROBABLY NEED 90S IN THERE! && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID- MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW FALLS BELOW NORMAL STATE WIDE MONDAY. KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL. PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO GUIDANCE. TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A BIT MORE THURSDAY INTO FRIDAY. && .AVIATION /13Z SATURDAY THROUGH WEDNESDAY/... PATCHY IFR AND LOWER CIGS AND VSBYS WILL CONTINUE THROUGH 14Z THIS MORNING. LOW STRATO CU WILL SPREAD ACROSS THE LOWER SUSQ...AND OVER THE NW MTNS. THE CENTRAL PA REGION HAS SEEN THE DEVELOPMENT OF SOME MID LEVEL CLOUDS. LOW STRATOCU COULD STILL SPREAD OUT THROUGH 15Z...BEFORE IT AND THE PATCHY FOG DISSIPATES. IFR IS POSSIBLE IN AND AROUND TSRA THIS AFTERNOON AND EARLY EVENING DUE TO A STRONGER CHANCE FOR CONVECTION...ESPECIALLY JST...AOO AND ALONG THE LOWER SUSQ TAF SITES FROM 22Z THROUGH 03Z TONIGHT. OUTLOOK... .SAT-SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS... ESPECIALLY SUNDAY AS A COLD FRONT MOVES THROUGH. .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/CERU/MARTIN NEAR TERM...LA CORTE/CERU/MARTIN SHORT TERM...LAMBERT/MARTIN LONG TERM...GRUMM/MARTIN AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
1055 AM CDT SAT AUG 4 2012 UPDATED NEAR-TERM AND AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY THROUGH SUNDAY. NEAR-TERM... HAD TO ADJUST TIMING OF CONVECTION INTO AREA PER EXTRAPOLATION OF IA CONVECTION AND 04/12Z RUN OF HRRR AND RAP. BEGAN PRECIP EARLIER THIS AFTERNOON AND ENDING EARLIER IN THE EVENING AS FRONT IS MOVING A BIT FASTER THAN EARLIER ANTICIPATED. BEST SEVERE PARAMETERS POINT TO THE SOUTH OF THE FORECAST AREA...BUT SHORT- TERM MODELS INDICATE SCATTERED CONVECTION AHEAD OF MAIN LINE BEGINNING BY 19Z IN EAST-CENTRAL WI IN CORRIDOR OF INSTABILITY AND DIFFERENTIAL HEATING. OTHERWISE...MAIN LINE /HEAVIEST RAIN/ EXPECTED TO MOVE THROUGH THE FORECAST AREA BY ABOUT 00Z. JKL PREVIOUS SHORT TERM DISCUSSION... REGARDLESS OF THE SEVERITY OF THE THUNDERSTORMS WE SHOULD GET A LINE OF STORMS WITH HEAVY RAIN. PRECIPITABLE WATER VALUES OVER 2 INCHES ARE FORECAST DURING THE LATE AFTERNOON AND EARLY EVENING. THE FRONT SHOULD BE MOVING QUICK ENOUGH TO PREVENT WIDESPREAD FLOODING BUT WOULD NOT BE SURPRISED IF THERE ARE SOME 1 TO 2 INCH PER HOUR RAINFALL RATES AND LOCAL URBAN OR SMALL STREAM FLOODING. AREA SOUTH OF HIGHWAY 29 IS SO DRY THAT THE RAINFALL IS MUCH NEEDED. THE FRONT WILL EXIT TONIGHT AND THE RAIN WILL END BY MIDNIGHT IN MOST PLACES. COOLER AND DRIER AIR WILL ARRIVE OVERNIGHT AND END THE NEED FOR AIR CONDITIONING FOR AWHILE. "REAL WISCONSIN" SUMMER WEATHER SHOULD RETURN SUNDAY WITH HIGHS IN THE 70S...LOW HUMIDITIES AND A NICE BREEZE. IT WILL PROBABLY BE THE NICEST DAY SINCE JUNE 25TH OVER MUCH OF THE AREA. .LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. THE LATEST MEDIUM RANGE MODELS PLACE THE WESTERN GREAT LAKES REGION WITHIN NW FLOW ALOFT FOR MUCH OF THE NEXT WEEK. SEVERAL SHORTWAVES WITHIN THIS NW FLOW COULD IMPACT THE REGION...BUT OUTSIDE OF THE FIRST WAVE ARRIVING MONDAY NIGHT...MODELS DO NOT HAVE A GOOD HANDLE OF THESE IMPULSES. COULD SEE ANOTHER WAVE DROP INTO THE AREA WEDNESDAY INTO WEDNESDAY NIGHT AND ANOTHER LATER IN THE WEEK...BUT MOISTURE WILL BE LACKING WITH EACH SYSTEM. WILL HAVE TO TAKE A GENERAL BLEND MID-WEEK ONWARD. SUNDAY NIGHT INTO MONDAY NIGHT...HIGH PRESSURE WILL MOVE FROM THE CENTRAL GREAT PLAINS TO THE SOUTHERN GREAT LAKES SUNDAY NIGHT. WINDS LOOK LIGHT ENOUGH FOR DECOUPLING AND WILL SEE MOSTLY CLEAR CONDITIONS...SO WILL SIDE ON THE COLD SIDE OF GUIDANCE FOR LOW TEMPS. ON MONDAY...AN AMPLIFYING NORTHERN STREAM SHORTWAVE WILL DROP A COOL FRONT INTO LAKE SUPERIOR IN THE AFTERNOON. BUT HIGH PRESSURE WILL STICK AROUND OUR AREA TO GIVE A MOSTLY SUNNY AND WARM DAY WITH HIGHS IN THE LOW TO MID 80S. THIS FRONT WILL THEN DROP ACROSS NORTHERN WISCONSIN AND INTO CENTRAL WISCONSIN MONDAY NIGHT. HARD TO SAY IF THERE WILL BE ENOUGH MOISTURE FOR PRECIP...BUT POTENTIAL WILL EXIST SO WILL KEEP A SPOTTY MENTION IN THE FORECAST FOR NORTHERN WISCONSIN. REST OF THE FORECAST...THE FRONT WILL FINISH CROSSING CENTRAL AND NORTHEAST WISCONSIN TUESDAY MORNING BEFORE DEPARTING BY THE AFTERNOON. NOT TO THRILLED WITH PRECIP CHANCES IN THE MORNING...AS MID-LEVEL MOISTURE WILL HAVE ALREADY PULLED OUT BY THIS POINT. WILL REMOVE POPS. TEMPS WILL COOL SLIGHTLY BEHIND THE FRONT TO THE UPPER 70S AND LOWER 80S. HIGH PRESSURE WILL DRIFT ACROSS THE REGION TUESDAY NIGHT BUT THEN WILL BE ANTICIPATING THE NEXT WAVE SWINGING ACROSS THE REGION WEDNESDAY INTO WEDNESDAY NIGHT. WILL HAVE SOME SMALL PRECIP CHANCES OVER THIS PERIOD. MAY HAVE ANOTHER WAVE ARRIVE FRIDAY INTO SATURDAY...THOUGH AGAIN PRECIP CHANCES LOOK SMALL. WILL TRY TO REMOVE CHANCES WHERE POSSIBLE UNTIL MODELS GET A BETTER HANDLE ON THE DETAILS. && .AVIATION...LINE OF STORMS FORECAST TO ENTER WESTERN PART OF FORECAST AREA BY 18Z...THEN MOVE EAST THROUGH AREA BY 00Z. IFR CONDITIONS CAN BE EXPECTED WITH STRONGER STORMS. WIND GUSTS OVER 40 KTS POSSIBLE WITH STORMS AT AIRPORTS IN CENTRAL AND EAST- CENTRAL WI. BEST CHANCE FOR SEVERE WILL BE OVER SOUTHERN PART OF STATE. JKL && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1003 AM CDT SAT AUG 4 2012 .UPDATE...MAKING CHANGES ON TIMING AS IOWA CONVECTION LOOKS TO BE OUR SHOW THIS AFTERNOON. HAVE UPPED POPS TO CATEGORICAL AND HAVE ADDED SEVERE TO THE GRIDS AS WELL. AXIS OF 1000 DCAPE INTO SOUTHERN WI...WITH WATER VAPOR/RUC COMBO SHOWING SHORTWAVE NE KS VICINITY SHIFTING NORTHEAST. MID LEVEL LAPSE RATES OF AROUND 7 WITH BUILDING CAPES INTO SRN WI. ONLY THIN CIRRUS TO CONTEND SO PLENTY OF HEATING. 0-8 KM SHEAR AROUND 50 KNOTS...AND SEEING SOME 40 KNOTS 0-6 KM. 0-1 SHEAR MORE SO- SO...TORNADO THREAT MINIMAL BUT NON-ZERO. MAIN CONCERN WILL BE FOR DAMAGING WINDS. PC && .AVIATION/18Z TAFS/...HAVE ADJUSTED TIMING OF CONVECTION BASED ON TRENDS ACROSS IOWA. LOOKS LIKE AROUND 19Z IN KMSN AND AROUND 21Z TOWARDS KMKE. PC && .PREV DISCUSSION... /ISSUED 330 AM CDT SAT AUG 4 2012/ TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM BIG CONCERN IS IMPACT OF CURRENT LINE OF CONVECTION ON THE EVOLUTION AND TIMING OF THUNDERSTORMS ACROSS FORECAST AREA LATER TODAY. SUB-SEVERE WIND REPORTS SINCE 12 MIDNIGHT HAVE INDICATED A WEAKENING TREND TO THE LINE...SUPPORTED BY REDUCED LIGHTNING ACTIVITY AND A SLIGHT WARMING OF CLOUD TOPS. LINE WILL REACH NW CWA BETWEEN 245 AM AND 3AM ON CURRENT PACE. HRRR AND RAP SUGGEST A RAPID WEAKENING OF CURRENT LINE AS IT MOVES AWAY FROM MAIN LOW-LEVEL JET AXIS AND INSTABILITY...THEN ALL MODELS SHOW A RE-FIRING OF CONVECTION ALONG SURFACE FRONT MID-LATE MORNING FROM WEST CENTRAL WI INTO FAR NE IOWA AS FRONTOGENETIC RESPONSE INCREASES AHEAD OF TROUGH. STILL FEEL BEST OPPORTUNITY FOR STRONG/SEVERE IN CWA DURING THE LATE AFTERNOON INTO THIS EVENING WITH ENHANCED FORCING AND 0 TO 6KM SHEAR INCREASING TO 30 TO 40 KTS AHEAD OF COLD FRONT AND POSITIVE-TILT 500 MB TROUGH AS IT SWINGS TO A MORE NEUTRAL POSITION WHILE CROSSING THE WESTERN GREAT LAKES TONIGHT. FORCING FOR ASCENT WILL BE AIDED BY UPPER LEVEL DIVERGENCE OF RRQ OF 100-110KT 250 MB JET MAX LIFTING ACROSS WRN GREAT LAKES REGION DURING THE LATE AFTERNOON AND EVENING. IF CLOUD DEBRIS DOESN/T OVERLY INHIBIT DAYTIME HEATING...SURFACE BASED CAPE OVER CWA RISES TO AROUND 1600 J/KG...COMPUTED LIFTED INDICES OF -5 TO -7...PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES. FEEL CLOUDS WILL THIN ENOUGH AND WARM ADVECTION AHEAD OF FRONT WILL BRING HIGH TEMPERATURES IN THE LOW 90S INLAND...WITH SOUTHERLY WINDS TURNING INSHORE ENOUGH TO KEEP LAKESHORE AREAS IN THE MID-UPPER 80S. BUFKIT SOUNDINGS SHOW WELL MIXED BOUNDARY LAYER BY LATE AFTERNOON...WITH DRY SUB-CLOUD LAYER ENHANCING POTENTIAL FOR DAMAGING WINDS REFLECTED IN FORECAST DOWNDRAFT CAPE OF 1500 TO 2000 J/KG. PRECIPITATION ENDS IN THE EAST WITH TROUGH PASSAGE AROUND 06Z WITH DRIER AIR POURING IN ON NORTHWEST WINDS AS HIGH BUILDS IN FROM THE WEST. SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH HIGH PRESSURE TO MOVE IN BEHIND THE COLD FRONT FOR SUNDAY AND MONDAY...BRINGING PLEASANT WEATHER TO SOUTHERN WISCONSIN. MAY SEE A FEW LINGERING CLOUDS NORTH SUNDAY AS THE UPPER TROUGH AXIS SWINGS THROUGH...WITH SUNNY SKIES ACROSS THE FORECAST AREA MONDAY. COOLER AIR BEHIND THE DEPARTING SYSTEM WILL RETURN TEMPERATURES TO NEAR NORMAL SUNDAY...WARMING BACK UP JUST A BIT MONDAY. TUESDAY AND WEDNESDAY....FORECAST CONFIDENCE...MEDIUM MAY SEE A WEAK WAVE OR TWO SLIDE THROUGH TUESDAY AND WEDNESDAY...BUT OVERALL PRECIP CHANCES TOO LOW FOR POPS AT THIS TIME. WARM ADVECTION IS EXPECTED INTO THE AREA WITH UPPER RIDGE TO THE WEST...SO SHOULD SEE TEMPS RUN A FEW DEGREES ABOVE NORMAL. THURSDAY AND FRIDAY...FORECAST CONFIDENCE...MEDIUM MODELS ADVERTISING A STRONGER WAVE FOR THURSDAY...SO WENT WITH CHANCE POPS MOST PLACES. LOOKS QUIETER FOR FRIDAY BEHIND THE SYSTEM. NO BIG CHANGE EXPECTED IN TEMPS THROUGH THE END OF THE WORK WEEK...WITH 80S CONTINUING. AVIATION/12Z TAFS/... WILL ADJUST TAFS FOR MVFR/IFR FOG IN THE NEAR TERM...THEN VFR UNTIL EXPECTED THUNDERSTORMS BRING MVFR CONDITIONS AND GUSTY WINDS. 000Z AND RAPID REFRESH MODELS SUPPORT KEEPING LATE AFTERNOON/EARLY EVENING TIMING FOR THUNDERSTORMS THAT IS IN CURRENT FORECAST. NORTHWEST WINDS KEEP BOUNDARY LAYER MIXED...WITH DRY AIR MOVING IN BEHIND COLD FRONT KEEPING OUT ANY CHANCE OF POST-FRONTAL LOW CLOUDS/FOG AT THIS TIME. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
640 AM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH MONDAY 246 AM CDT SAT AUG 4 2012 MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY. SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO NORTHERN IOWA. ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI- RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO 40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING. ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA. THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA. WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP. SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL FOR LESS CONVECTION TO OCCUR. ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY 246 AM CDT SAT AUG 4 2012 THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY. && .AVIATION... 640 AM CDT SAT AUG 4 2012 WAVES OF CONVECTION PASSING THROUGH REGION AHEAD OF APPROACHING UPPER LOW HAVE BEEN A BIT PROBLEMATIC EARLY THIS MORNING. GENERALLY VFR CONDITIONS PREVAIL EXCEPT IN AREAS OF STRONGER CONVECTION SO TRIED TO TIME BETTER THUNDERSTORM WINDOWS IN SHORT TERM. OFF AND ON ACTIVITY LIKELY TO CONTINUE THROUGH MOST OF THE MORNING THOUGH AND AS UPPER LOW GETS EVEN CLOSER...ASSOCIATED COLD FRONT WILL BEGIN LIMITING STORM CHANCES...PUSHING THREAT EAST. MESOSCALE MODELS STILL HINT AT STRONGER STORMS REFORMING THIS AFTERNOON MAINLY SOUTH AND SOUTHEAST OF TAF SITES SO EXPECT GENERALLY DRYING TREND BY EVENING AS NORTHWEST WINDS TAKE OVER. SHOULD ALSO SEE CLEARING TONIGHT AS HIGH PRESSURE BUILDS IN BUT NORTHWEST WINDS BEHIND SYSTEM SHOULD KEEP THINGS MIXED AND PREVENT ANY FOG. && .ARX WATCHES/WARNINGS/ADVISORIES... 246 AM CDT SAT AUG 4 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM....04 AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1129 AM MDT SAT AUG 4 2012 .AVIATION...SMALL PATCH OF MVFR STRATUS NEAR KCOS AS OF 17Z WILL DISSIPATE OVER THE NEXT HOUR AND WON`T INCLUDE IN THE NEW 18Z TAF. ISOLATED TO SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS THIS AFTERNOON...THOUGH STORMS SHOULD DISSIPATE AS THEY MOVE OFF THE MTNS AND WILL LIKELY NOT IMPACT KCOS AND KPUB...AS MOISTURE AND INSTABILITY ON THE PLAINS IS LIMITED. SLIGHTLY BETTER ODDS OF A STORM AT KALS...THOUGH CHANCE IS STILL TOO LOW TO MENTION IN THE TAF AT THIS POINT. TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY AFTER SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH THE NIGHT. && .PREV DISCUSSION... /ISSUED 408 AM MDT SAT AUG 4 2012/ SHORT TERM... (TODAY AND TONIGHT) COLD FRONT CURRENTLY RACING THROUGH SOUTHEAST CO AND SHOULD REACH THE SOUTHERN BORDER BY 12-13Z. WIND GUSTS BEHIND THE FRONT HAVE BEEN IN THE 40-45 KT RANGE SO FAR THIS MORNING ACROSS PORTIONS OF SOUTHERN EL PASO AND PUEBLO COUNTIES. HRRR AND LOCAL 4KM WRF SHOW POTENTIAL FOR SOME ISOLATED SHOWERS TO DEVELOP BEHIND THE FRONT ACROSS THE SOUTHEAST PLAINS EARLY THIS MORNING AS IT ENCOUNTERS HIGHER DEW POINTS ACROSS THE FAR SOUTHEAST PLAINS. WILL MAINTAIN SOME 20 POPS THROUGH 15Z FOR THE FAR SOUTHERN AND EASTERN PORTIONS OF THE AREA. OTHERWISE...REMAINDER OF THE AREA SHOULD REMAIN DRY THROUGH THE EARLY MORNING HOURS. NAM ALSO DEVELOPS SOME MVFR STRATUS EARLY THIS MORNING ALONG THE CREST OF THE PALMER DIVIDE. GUSTY NORTH WINDS WILL CONTINUE THROUGH THE MORNING BEFORE SWINGING AROUND FROM THE EAST TO SOUTHEAST DURING THE AFTERNOON ACROSS THE PLAINS. DEW POINTS BEHIND THE FRONT DROP INTO THE 40S BY AFTERNOON...AND MODEL SOUNDINGS SHOW A STOUT CAPPING INVERSION WHICH SHOULD HINDER AFTERNOON THUNDERSTORM DEVELOPMENT ACROSS THE PLAINS. MEANWHILE...MONSOON PLUME HAS BEEN SHUNTED EVEN FARTHER SOUTH TODAY...WITH PRECIP WATERS ABOVE 100% OF NORMAL NOW PUSHED TO ALONG THE SRN CO BORDER AND INTO NEW MEXICO. STILL ENOUGH MOISTURE PRESENT FOR ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE SOUTHERN MTS TODAY...THOUGH GREATEST COVERAGE SHOULD BE NEAR THE NM BORDER. HAVE DECREASED POPS FARTHER NORTH WHERE SOUNDINGS LOOK QUITE DRY. LATEST MODELS ARE TRENDING PRECIPITATION SOUTHWARD TO ALONG THE FRONTAL BOUNDARY ACROSS NORTHEAST NEW MEXICO...AND HAVE CUT BACK POPS TO ISOLATED ALONG THE NRN SLOPES OF THE RATON RIDGE. GUIDANCE TEMPERATURES TODAY STILL SHOW QUITE A DISCREPANCY...WITH MAV RUNNING AROUND 5 TO 10 DEGREES COOLER THAN MET ACROSS THE PLAINS. HAVE GENERALLY SPLIT THE DIFFERENCE FOR NOW. MTN AREAS SHOULD SEE TEMPS SIMILAR TO A DEGREE OR TWO COOLER THAN THOSE OF YESTERDAY. TONIGHT...CONVECTION SHOULD DIMINISH QUICKLY THIS EVENING WITH LOSS OF HEATING. WILL MAINTAIN SOME ISOLATED POPS ACROSS THE SRN MTS UNTIL 06Z...THEN REMOVE POPS THERE-AFTER. MIN TEMPS TONIGHT SHOULD BE COOLER ACROSS THE PLAINS AND HAVE CUT THEM BACK A COUPLE DEGREES. -KT LONG TERM... (SUNDAY THROUGH SATURDAY) THE EXTENDED FORECAST WILL BE DOMINATED BY HIGH PRESSURE OVER THE FOUR CORNERS REGION WITH VERY HOT CONDITIONS FOR THE LOWER ELEVATIONS AND MOUNTAIN THUNDERSTORMS. HIGH PRESSURE BEGINS TO BUILD NORTHWARD SUNDAY MORNING AS AN UPPER LEVEL TROUGH MOVES EAST ACROSS THE GREAT LAKES. A WEAK DISTURBANCE CAUGHT UNDER THE BUILDING HIGH WILL DRIFT NEAR THE COLORADO NEW MEXICO BORDER AND HELP GENERATE SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER THE SAN JUAN AND SOUTHERN SANGRE DE CRISTO RANGES. MODELS KEEP THIS ACTIVITY GOING THROUGH SUNDAY NIGHT INTO MONDAY MORNING. HIGH PRESSURE CONTINUES TO BUILD ACROSS THE REGION ON MONDAY WITH AFTERNOON THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS. FLOW ALOFT WILL REMAIN NORTHWESTERLY AROUND THE STRENGTHENING HIGH WHICH WILL HELP PUSH CONVECTION INTO THE I-25 CORRIDOR. THIS ACTIVITY IS FORECAST TO DIMINISH THROUGH THE EVENING HOURS. TEMPERATURES ON SUNDAY WILL START TO WARM WITH UPPER 80S TO LOWER 90S FOR THE PLAINS. BY MONDAY...HIGHS WILL BE PUSHING INTO THE UPPER 90S TO LOWER 100S FOR THE PLAINS. TUESDAY THROUGH SATURDAY...HIGH PRESSURE WILL ANCHOR ITSELF OVER THE FOUR CORNERS AREA AND DOMINATE THE WEATHER. THIS WILL HELP KEEP TEMPERATURES WARM THROUGH THE EXTENDED WITH UPPER 90S TO LOWER 100S EXPECTED FOR THE PLAINS. WITH THE MONSOON MOISTURE TAP WELL TO THE WEST AND DRIER AIR ACROSS COLORADO...THUNDERSTORM COVERAGE IS FORECAST TO BE MINIMAL AND DIURNALLY DRIVEN. WITH WEAK FLOW ALOFT...ANY THUNDERSTORMS THAT DO DEVELOP WILL REMAIN ANCHORED TO THE MOUNTAINS. 88 AVIATION... MVFR STRATUS WILL DEVELOP ALONG THE CREST OF THE PALMER DIVIDE AND NORTH SIDE OF THE RATON RIDGE THIS MORNING. NORTH WINDS GUSTING TO 30-40 KTS WILL CONTINUE AT KPUB AND KCOS THROUGH 12-15Z BEFORE WINDS DECREASE AND SWING AROUND FROM THE EAST TO SOUTHEAST BY THE AFTERNOON. STRATUS SHOULD DISSIPATE BY LATE MORNING...AND STAY PREDOMINANTLY TO THE NORTH OF THE KCOS TERMINAL. ISOLATED TO SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS DURING THE AFTERNOON...THOUGH SHOULD DISSIPATE AS THEY MOVE OFF THE MTS AND SHOULD NOT IMPACT KCOS AND KPUB. KALS WILL HAVE A SLIGHTLY BETTER CHANCE OF SEEING A PASSING -TSRA IN THE AFTERNOON...THOUGH ODDS TOO LOW AT THIS POINT TO INCLUDE IN TAF AS LOW LEVEL MOISTURE SHOULD BE LESS TODAY. -TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY AFTER SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH THE NIGHT. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 10/27
AREA FORECAST DISCUSSION
NWS MIAMI FL
154 PM EDT SAT AUG 4 2012 .SHORT TERM...(TONIGHT-MONDAY NIGHT) THE LATEST SURFACE ANALYSIS SHOWED A TROUGH EXTENDING SOUTH OF A WEAK LOW PRESSURE AREA CENTERED ALONG IT NORTHWEST OF THE BAHAMAS OR EAST SOUTHEAST OF FT PIERCE. LIGHT WNW FLOW ACROSS THE LOCAL AREA TO ITS SOUTHWEST COMBINED WITH THE ATLANTIC SEA BREEZE HAS ALREADY LED TO A FEW SHOWERS DEVELOPING ALONG IT OVER PALM BEACH COUNTY NEAR THE COAST AND FARTHER SOUTH ALONG THE EAST COAST AREAS. LOCAL WRF AND HRRR MODEL REFLECTIVITIES SEEM TO BE INITIALIZING WELL WITH THIS PATTERN AND GENERALLY INDICATE THIS ACTIVITY INCREASING IN COVERAGE THROUGH THE COURSE OF THE AFTERNOON TODAY AS THE ATL SEA BREEZE CONTINUES TO MAKE ITS PUSH INLAND. THIS COMBINED WITH THE ACTIVITY FROM YESTERDAY COULD GENERATE MORE FLOODING CONCERNS DEPENDING ON WHERE THE HEAVIEST ACTIVITY BECOMES CONCENTRATED AS THE DAY PROGRESSES. THE MORNING UPPER AIR SOUNDING AT MIAMI ALONG WITH THE LATEST SATELLITE DERIVED 500 MB TEMPERATURES INDICATE A MORE STABLE ENVIRONMENT COMPARED TO YESTERDAY AND WITH THE BEST INSTABILITY OR COOLER MID /UPPER-LEVEL AIR NOW TO THE WEST OF THE FL PENINSULA CLOSER TO THE BROAD UPPER LOW CENTER OVER THE GULF OF MEXICO. THEREFORE...THE MAIN IMPACTS FROM ANY STRONG STORMS THAT DO DEVELOP SHOULD REMAIN SUB-SEVERE AND MAINLY ASSOCIATED WITH STRONG WIND GUSTS UP TO 50 MPH. THE LATEST NUMERICAL MODEL GUIDANCE HAS INITIALIZED WELL WITH THIS SURFACE TROUGH AND LOW JUST EAST OF THE LOCAL AREA AND GENERALLY INDICATES THIS FEATURE CONTINUING WESTWARD OVER SOUTH FLORIDA THROUGH TONIGHT...THEN WEST OF THE FL PENINSULA SUNDAY THROUGH MONDAY. IN ITS WAKE...MOIST SOUTHEAST FLOW WILL BE EXPECTED AS THE AFOREMENTIONED SURFACE TROUGH/UPPER LOW CONTINUES WEST AND AWAY FROM THE FL PENINSULA AND ERNESTO CONTINUES ITS WESTWARD TRACK ACROSS THE CARIBBEAN SEA AND PASSES THE LOCAL AREA TO THE SOUTH SUNDAY THROUGH MONDAY NIGHT. MODERATE EAST AND SOUTHEAST FLOW THROUGH THE LOW LEVELS DUE TO A SLIGHTLY ENHANCED GRADIENT BETWEEN ERNESTO TO THE SOUTH AND THE SUBTROPICAL RIDGE TO THE NORTH COMBINED WITH PRECIPITABLE WATER VALUES AROUND THE TWO INCH MARK WILL KEEP THE RAIN CHANCES IN THE FORECAST THROUGH THE PERIOD. .LONG TERM (TUESDAY-FRIDAY)... ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID WEEK. WITH THE EASTERLY FLOW IN PLACE...SHOWERS/TSTMS THAT DEVELOP DURING THIS TIME SHOULD HAVE THE BEST CHANCE OF FORMING OVER THE INLAND AND WESTERN LOCATIONS EACH AFTERNOON. MOISTURE BEGINS TO INCREASE ACROSS THE AREA BY FRI. && .MARINE... A TROUGH EXTENDING SOUTH OF A WEAK LOW PRESSURE AREA CENTERED NORTH OF THE BAHAMAS OR EAST SOUTHEAST OF CAPE CANAVERAL IS FORECAST TO TRACK WEST AND NORTHWEST ACROSS THE FLORIDA PENINSULA THROUGH TONIGHT. SCATTERED SHOWER AND STORMS ASSOCIATED WITH THIS FEATURE WILL LEAD TO PERIODS WITH REDUCED VISIBILITIES ALONG WITH LOCALLY HIGHER WINDS AND SEAS...ESPECIALLY ACROSS THE ATLANTIC WATERS. SUNDAY THROUGH THE MID WEEK PERIOD...MODERATE EASTERLY WINDS AND SEAS WILL BE ANTICIPATED AS TROPICAL STORM ERNESTO PASSES SOUTH OF THE MARINE AREA ACROSS THE CARIBBEAN SEA. FOR THE LATEST INFORMATION REGARDING ERNESTO...REFER TO THE LATEST FORECASTS AND ADVISORIES ISSUED BY THE NATIONAL HURRICANE CENTER. && .FIRE WEATHER... NO CONCERNS THROUGH THE WEEKEND AND INTO THE UPCOMING WEEK AS PLENTY OF MOISTURE AND RAIN CHANCES REMAIN IN THE FORECAST.SOME DRIER AIR WITH MODERATE EASTERLY FLOW APPEARS POSSIBLE THROUGH THE MID-WEEK PERIOD. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 77 88 79 88 / 50 60 40 60 FORT LAUDERDALE 79 90 80 89 / 50 60 40 60 MIAMI 78 89 79 89 / 50 60 40 60 NAPLES 76 92 76 90 / 40 50 40 60 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
147 PM EDT SAT AUG 4 2012 .AVIATION... SATELLITE AND RADAR SHOW AN AREA OF LOW PRESSURE OFF THE COAST OF CENTRAL FLORIDA AND MOVING TO THE NORTHWEST. SHOWERS AND THUNDERSTORMS REMAINED OVER THE LOCAL WATERS AND BAHAMAS. THE SEA BREEZE BOUNDARIES WERE BEGINNING TO MOVE INLAND...WITH ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING ALONG IT. EXPECT ACTIVITY TO BECOME MORE NUMEROUS OVER THE NEXT COUPLE OF HOURS...BUT MOST OF THE ACTIVITY MAY BE JUST TO THE WEST OF THE EAST COAST TAF SITES. SO WILL KEEP VCTS AT THE TAF SITES. KEPT VCSH TONIGHT ACROSS THE REGION AS THE AREA OF LOW PRESSURE MOVES ACROSS FLORIDA TONIGHT THROUGH SUNDAY. AT THIS TIME DID NOT CARRY THUNDERSTORMS OVERNIGHT...BUT THIS WILL NEED TO BE MONITORED. EXPECT NUMEROUS SHOWERS AND THUNDERSTORMS TO REDEVELOP ACROSS THE REGION ON SUNDAY...PUSHING TOWARDS KAPF IN THE AFTERNOON. MOSTLY VFR CONDITIONS WILL CONTINUE...BUT MVFR CIG/VIS ARE POSSIBLE IN AND AROUND SHOWERS AND THUNDERSTORMS. EAST TO SOUTHEAST WINDS AROUND 10 KNOTS ARE EXPECTED AT THE EAST COAST TAF SITES THIS AFTERNOON...WITH A WEST TO NORTHWEST WIND AT NAPLES. LIGHT EASTERLY FLOW IS EXPECTED OVERNIGHT...WITH THE EAST COAST SEA BREEZE PUSHING BY MID/LATE MORNING. && .PREV DISCUSSION... /ISSUED 724 AM EDT SAT AUG 4 2012/ AVIATION... A TROPICAL WAVE BETWEEN THE BAHAMAS AND MAINLAND...WHICH EXTENDS SW OVER N CUBA...WILL SLOWLY MOVE W THROUGH THE PERIOD. THIS FEATURE WILL SLOWLY MOVE OVER THE SE FLA COAST THIS MORNING AND WILL MOVE ACROSS S FLA THROUGH THE DAY. SCATTERED SHRA WITH ISOLD TSRA AT THIS TIME WELL E IN THE ATLC BUT EXPECT SHRA TO DEVELOP BY LATE MORNING AND POSSIBLE TSRA AS EARLY AS 16Z ALONG THE E COAST. WILL HAVE VCSH IN E COAST TERMINALS INITIALLY BUT POSSIBLE TSRA BY 16Z. ANY TSRA THAT DEVELOP WILL MOVE SLOWLY SO HEAVY RA AND POSSIBLE MVFR CIG/VSBY WILL BE POSSIBLE. MODEL GUIDANCE AT THIS TIME DOES NOT INDICATE MVFR CIG/VSBY AND MODELS PROJECT THE BULK OF THE SHRA/TSRA TO THE E OF THE WAVE MOVING N ALONG THE FLA E COAST. HEATING OF THE DAY WILL BE THE MAIN INPUT TO PRECIPITATION. SFC WINDS ENE < 10 KNOTS BECOMING ESE 10 TO 15 KNOTS AS THE WAVE MOVES PAST ANY ONE TERMINAL LATER TODAY. PREV DISCUSSION... /ISSUED 358 AM EDT SAT AUG 4 2012/ .LOCALLY HEAVY RAINFALL POSSIBLE TODAY... .MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES... DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH? A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO 50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS), DURATION AND AMOUNT IS OF HIGH UNCERTAINTY. AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT NIGHT. THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL YESTERDAY. TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI. MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE NEEDED AT THIS TIME. FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN TYPICALLY HIGH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 78 89 79 / 70 50 60 50 FORT LAUDERDALE 88 80 89 79 / 70 50 60 50 MIAMI 89 78 89 79 / 70 50 60 50 NAPLES 91 76 92 77 / 50 30 50 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
341 PM CDT SAT AUG 4 2012 .DISCUSSION... ISSUED 341 PM CDT SAT AUG 4 2012 COLD FRONT HAS BEEN MOVING A BIT QUICKER TOWARD THE CWA...AND WAS LOCATED FROM NEAR THE QUAD CITIES SOUTHWEST TO NEAR KANSAS CITY. WELL-DEFINED MESOSCALE VORTEX FROM CONVECTION IN IOWA HELPED TO DEVELOPED AN MCS WHICH HAS BEEN ROLLING ACROSS THE NORTHERN THIRD OF ILLINOIS THIS AFTERNOON. SOME OF THE SOUTHERN FRINGES CONTINUE TO PUSH ACROSS AREAS FROM CANTON EAST TO EL PASO AT MID AFTERNOON. INSTABILITY OVER THE AREA PEAKED EARLY THIS AFTERNOON WITH CAPES AROUND 4000 J/KG...BUT SPC MESOANALYSIS HAS BEEN SHOWING SOME DECREASE IN CAPES AND INCREASE IN CAPPING ALOFT. HOWEVER...STILL QUITE A BIT OF INSTABILITY AVAILABLE FROM SOUTHERN MISSOURI NORTHEAST INTO EAST CENTRAL ILLINOIS. LATEST NAM AND HRRR SHOW DEVELOPMENT OCCURRING IN THESE AREAS OVER THE NEXT COUPLE HOURS. WILL MAINTAIN LIKELY POPS OVER A LARGE PART OF THE CWA THIS EVENING...THEN LIMIT THEM TO 40-50 PERCENT AFTER MIDNIGHT ACROSS THE EAST CENTRAL AND SOUTHEAST CWA. ANY LINGERING RAIN ACROSS THE FAR SOUTHEAST WILL LIKELY BE ENDING BEFORE SUNRISE. LITTLE CHANGE MADE TO THE REMAINDER OF THE FORECAST. BRIEF COOL DOWN WILL BE NOTED EARLY THIS WEEK AS HIGH PRESSURE DRIFTS EAST ACROSS THE AREA. A SLOW WARMING TREND WILL BRING TEMPERATURES BACK TO NEAR 90 MUCH OF THE REMAINDER OF THE WEEK...WITH HOTTER WEATHER KNOCKING ON THE DOOR AS WE REMAIN ON THE FRINGE OF THE UPPER RIDGING ACROSS THE WESTERN HALF OF THE NATION. MAIN FEATURE OF CONCERN IN THE LONG RANGE IS ON THURSDAY AND FRIDAY...WHEN A PIECE OF ENERGY DROPS SOUTHEAST OUT OF THE CANADIAN PRAIRIES. GFS AND ECMWF NOT TOO FAR APART WITH THE TRACK OF THIS SHORTWAVE OVER THE GREAT LAKES...BUT THE GFS IS MORE AGGRESSIVE WITH BRINGING RAIN CHANCES ALL THE WAY SOUTH ACROSS ILLINOIS. WILL KEEP SOME SLIGHT CHANCES IN THE GRIDS THURSDAY AND THURSDAY NIGHT...BUT WILL LEAN MORE TOWARD THE ECMWF WITH ITS ODDS OF DRY WEATHER. GEELHART && .AVIATION... ISSUED 1233 PM CDT SAT AUG 4 2012 TS ADVANCING ON THE ILLINOIS RIVER VALLEY THIS AFTERNOON RESULTING IN TS ADDED TO PIA TAF. MORE LIKELY CLOSER TO 1830Z...BUT TEMPO GROUP IN. ALSO HAVE ADDED GUSTS FOR THE AFTERNOON MOMENTUM TRANSFER THAT MAY BE SLIGHTLY DELAYED BY THE SLOW IN DIURNAL HEATING WITH THE EXPANSIVE ALTOSTRATUS AND AC OUT THERE NOW. SO FAR...CONVECTIVE DEVELOPMENT REMAINS QUESTIONABLE ELSEWHERE...AND AM KEEPING THE VCSH IN THE BEST TIME FRAME. WILL UPDATE AS BECOMES NECESSARY FOR TS. TOWARDS MORNING...CHANCE FOR BR AND REDUCED VSBYS INTO MVFR/IFR CAT REMAIN FOR TERMINALS WITH RAIN. SO FAR...PIA AND BMI ARE MOST LIKELY AT THIS POINT. AND HAVE PUT IN A BRIEF TEMPO FOR THE EARLY MORNING/DAWN HOURS. HJS && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
434 PM EDT SAT AUG 4 2012 .SHORT TERM...(TONIGHT) ISSUED AT 432 PM EDT SAT AUG 4 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS LOOKING SHORTWAVE TROF ACROSS THE ERN DAKOTAS/MN. AT THE SFC...ASSOCIATED COLD FRONT IS SLICING THRU WRN LAKE SUPERIOR/WRN UPPER MI AND NW WI. DESPITE VIGOROUS LOOK OF SHORTWAVE...CONVECTION HAS BEEN KEPT IN CHECK BY ABUNDANT CLOUD COVER THAT HAS PERSISTED THRU THE DAY ACROSS GOOD PORTIONS OF UPPER MI AND NRN WI. LATEST SPC MESOANALYSIS SHOWS MLCAPE OF MOSTLY UNDER 500J/KG ACROSS THE FCST AREA. HIGHEST VALUES...A LITTLE OVER 500J/KG...ARE OVER THE E WHERE THERE HAS BEEN MORE SUNSHINE WITH SFC DWPTS AROUND 70F. IF MORE INSTABILITY HAD DEVELOPED...A FAIRLY SIGNIFICANT SVR WEATHER OUTBREAK WOULD PROBABLY BE GETTING UNDERWAY ACROSS THE FCST AREA AS DEEP LAYER SHEAR IS STEADILY INCREASING TOWARD THE 40-50KT RANGE DUE TO MIDLEVEL SPEED MAX APPROACHING THE AREA. MAIN SHOW TONIGHT WILL BE S OF THE AREA WITH CONVECTIVELY ENHANCED SHORTWAVE TRACKING TOWARD SRN WI/NRN IL/LWR MI. THE ONGOING ASSOCIATED CLUSTER OF STRONG/SVR STORMS WILL PASS S OF THE AREA. THAT SAID...OVER THE NEXT FEW HRS...SHRA/TSRA SHOULD TEND TO EXPAND NE ACROSS ROUGHLY THE E HALF OF THE FCST AREA AS HEIGHT FALLS AND RIGHT ENTRANCE OF UPPER JET STREAK WORK TO INCREASE UPWARD MOTION. THERE IS STILL THE POTENTIAL OF ISOLD SVR STORMS...BUT WITH CLOUD COVER NOW INCREASING EVEN OVER THE ERN FCST AREA TO PREVENT INSTABILITY FROM BUILDING HIGHER...IT APPEARS RISK OF SVR STORMS IS DIMINISHING. WILL KEEP SLIGHT RISK OF SVR WORDING IN HAZARDOUS WX OUTLOOK FOR THE NEXT FEW HRS OR SO. AFTER ANY SHRA/TSRA WITH COLD FRONT DEPART...ATTENTION TURNS TO VORT MAX AND SECONDARY COLD FRONT THAT WILL SWING INTO THE AREA LATE TONIGHT. THERE HAS BEEN FAIRLY SOLID COVERAGE OF SHRA AND EVEN SCT TSRA ACROSS SE MANITOBA INTO ADJACENT NRN ONTARIO WITH TROF AXIS THOUGH PCPN HAS TAKEN ON MORE OF A DIURNAL SCT COVERAGE THIS AFTN. AS TROF AXIS/VORT MAX DROP INTO THE AREA...THERE SHOULD BE DECENT SHRA COVERAGE LATE TONIGHT INTO SUN MORNING...ESPECIALLY SINCE CAA DROPS 850MB TEMPS TO AROUND 6C BY 12Z SUN. WITH WATER TEMPS AROUND 20C ON LAKE SUPERIOR...THE OVERWATER INSTABILITY WILL BE MORE THAN SUFFICIENT FOR LAKE ENHANCEMENT UNDER CYCLONIC FLOW WITH ARRIVAL OF VORT MAX. THUS...EXPECT SCT/NMRS SHRA TO DEVELOP LATE TONIGHT OVER THE NW HALF OF UPPER MI. AS ALWAYS...UPSLOPE NW WINDS WILL LEAD TO MOST NMRS COVERAGE OVER THE HIGHER TERRAIN DOWNWIND OF THE LAKE. .LONG TERM...(SUNDAY THROUGH SATURDAY) ISSUED AT 432 PM EDT SAT AUG 4 2012 GOOD AGREEMENT FM THE GFS/ECMWF/GEM-NHEM WITH OVERALL UPPER AIR PATTERN THROUGH THIS WEEK. PATTERN STARTS OFF WITH DEEP TROUGH OVER THE UPPER GREAT LAKES AND BROAD WEST-TO-EAST RIDGE ACROSS THE SOUTHERN TIER OF THE CONUS. BY MIDWEEK...RIDGE BECOMES MORE AMPLIFIED OVER INTERMOUNTAIN WEST INTO WESTERN CANADA WHILE TROUGHING REMAINS IN PLACE OVER EASTERN CANADA AND THE GREAT LAKES AND NORTHEAST CONUS. WEATHER WILL STAY ON THE ACTIVE SIDE AS MULTIPLE SYSTEMS IMPACT THE UPPER GREAT LAKES. FIRST WILL BE RIGHT AT BEGINNING OF LONG TERM ON SUNDAY. ANOTHER WEAKER COLD FRONT COMES THROUGH AREA ON TUESDAY. MUCH STRONGER LOW PRESSURE SYSTEM FCST TO PUSH ACROSS GREAT LAKES LATER THURSDAY INTO FRIDAY. IT IS THIS SYSTEM THAT SHOWS THE MOST POTENTIAL TO PRODUCE NOTEABLE PRECIPITATION AMOUNTS IN THE LONG TERM. SINCE THE LARGE TROUGH IS CLOSE BY AND RIDING REMAINS WELL TO THE WEST...EXPECT TEMPERATURES TO GENERALLY BE WITHIN A FEW DEGREES OF NORMAL. ONLY WARM EXCEPTION WILL BE ON MONDAY AHEAD OF ANOTHER COLD FRONT. SOME COOL PERIODS ARE EXPECTED AS WELL. COOLEST OF THE BUNCH LIKELY WILL BE ON SUNDAY...BUT SIMILAR COOLER TEMPERATURES MAY OCCUR AGAIN ON FRIDAY ON IN WAKE OF LOW PRESSURE SYSTEM MOVING THROUGH THE GREAT LAKES. A VERY CHAGEABLE WEATHER DAY IS IN STORE FOR SUNDAY. COLD FRONT THROUGH UPR MICHIGAN BY DAYBREAK WHILE SFC LOW PUSHES ACROSS JAMES BAY. COOL AND MOIST CYCLONIC FLOW SFC THROUGH H7 AFFECTS MOST CWA THROUGH LATE MORNING THEN HEIGHTS RISE QUICKLY WHILE EDGE OF SFC HIGH BUILDS IN MID-LATE AFTN. MOIST CYCLONIC FLOW AND THERMAL TROUGH WITH H85 TEMPS AS LOW AS +5C IN ADDITION TO A SHARP SECONDARY WAVE DROPPING THROUGH MEAN TROUGH SHOULD COMBINE TO BRING A PERIOD OF SHOWERS TO PORTIONS OF CWA THROUGH THE MORNING. WARM LK SUPERIOR TEMPS NEAR +20C ALSO ALLOW LAKE EFFECT PROCESSES TO ENHANCE PCPN AS DELTA T/S ARE AROUND 14-15C/LAKE INDUCED CAPES UP TO 250 J/KG. INCREASED POPS OVER UPSLOPE AREAS FAVORED BY NW BLYR WINDS. HIGHEST POPS IN THE MORNING...THEN RAPIDLY DROPPING OFF IN THE AFTN AS AREA QUICKLY RESIDES IN SUBSIDENCE REGION OF THE STRONG SHORTWAVE. SKIES PROBABLY CLEAR QUICKLY IN THE AFTN DUE TO SUBSIDENCE AND DRY AIR. TEMPS KIND OF TRICKY...BUT FOLLOWED TREND CLOSER TO GEM-REGIONAL SHOWING TEMPS STUCK IN THE MID 50S-LOW 60S INTO EARLY AFTN...THEN RISING TOWARD 70 DEGREES LATER IN THE DAY WITH INCREASING SUNSHINE. GUSTY WINDS OTHER FACTOR ON SUNDAY AS DEEP MIXING EXPECTED THROUGH EARLY AFTN BEFORE H85 WARM ADVECTION INCREASES STABILITY. MIXED LAYER WINDS THROUGH 16Z 35-40KT AND EXPECT GOOD PORTION OF THESE TO MIX TO SFC. STRONGEST WINDS NEAR EXPOSED LK SUPERIOR SHORE OF CNTRL AND EAST. EXPECT WINDS TO DIMINISH BY LATE DAY. HIGH PRESSURE AXIS REMAINS JUST SOUTH OF AREA SUNDAY NIGHT BUT WINDS BECOME LIGHT ENOUGH/PWAT LOW ENOUGH TO SEE SOME RADIATIONAL COOLING TAKE PLACE. LOWEST MINS SEEM LIKELY IN THE INTERIOR CNTRL AND EAST WHERE COLD SPOTS MAY DROP INTO LOWER 40S. MUCH DIFFERENT DAY ON MONDAY COMPARED TO COOLER/WINDY DAY ON SUNDAY. HIGH PRESSURE SLIDES EAST AND A WEAK COLD FRONT IS FCST TO DROP INTO UPR LAKES MONDAY NIGHT. NOT A LOT OF CLOUD COVER AHEAD OF FRONT THOUGH OTHER THAN ON THE KEWEENAW IN THE LATER AFTN. WITH H85 TEMPS 15C-16C EXPECT HIGHS TO REACH WELL INTO THE 80S AWAY FM LK MICHIGAN SHORE. AS UPR JET SLIDES ACROSS ONTARIO MONDAY NIGHT AND MID-LEVEL FGEN INCREASES OVR LK SUPERIOR...EXPECT BAND OF SHRA/TSRA TO DEVELOP ALONG SFC FRONT. FRONT SLIDES THROUGH CWA ON MONDAY NIGHT...WITH BETTER CHANCES OF SHRA/TSRA TIED INTO THE MID-LEVEL FORCING. SOUNDINGS SHOW DRY AIR LINGERING BLO H85-H7 DUE TO LIMITED MOISTURE ADVECTION FM THE GULF INTO THIS SYSTEM. SO...COVERAGE OF PRECIP WILL BE SPOTTY WITH THE FRONT. HIGH PRESSURE BUILDS BACK IN FOR TUESDAY WITH TEMPS IN THE 70S NORTH AND NEARING 80 DEGREES OVR THE SOUTH AND NEAR LK MICHIGAN. EXTENDED...MAIN CHANCES FOR SHRA/TSRA COME IN LATER WEDNESDAY NIGHT INTO THURSDAY AS ANOTHER UPPER LOW AND SFC LOW MOVE ACROSS THE UPR LAKES. CYCLONIC FLOW LINGERING IN THE WAKE OF THE SFC LOW COULD KEEP SOME SHRA GOING OVR THE AREA INTO FRIDAY...KIND OF SIMILAR TO WHAT IS EXPECTED ON SUNDAY. WITH EXPECTED CLOUDS/PCPN...TRIMMED TEMPS THURSDAY AND FRIDAY CLOSER TO LK SUPERIOR WHERE ONSHORE NORTHEAST FLOW SHOULD RESULT IN COOLER CONDITIONS. INCREASED WINDS OVR LK SUPERIOR SOME COMPARED TO GUIDANCE CONSENSUS BUT MAY NEED TO INCREASE FURTHER WITH LATER FCSTS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 139 PM EDT SAT AUG 4 2012 COLD FRONT MOVING ACROSS THE AREA THIS AFTN/EVENING AND FOLLOWED BY SECONDARY COLD FRONT LATE TONIGHT/SUN MORNING WILL BE THE FEATURES OF INTEREST. CLOUD COVER PER SATELLITE IMAGERY SHOULD SUFFICIENTLY HOLD INSTABILITY DOWN TO KEEP TSRA POTENTIAL MINIMAL WITH FIRST COLD FROPA AT KIWD/KCMX. HAVE ONLY INCLUDED VCSH MENTION THRU THE MID TO LATE AFTN HRS AT THOSE SITES. KSAW IS MORE LIKELY TO SEE TSRA LATER THIS AFTN DUE TO BETTER POTENTIAL FOR INSTABILITY TO BUILD PRIOR TO FROPA. IF TSRA OCCUR...IFR/LIFR CONDITIONS POSSIBLE ALONG WITH GUSTY WINDS. A PERIOD OF VFR CONDITIONS EXPECTED AT ALL SITES AFTER FIRST FROPA. SECONDARY COLD FROPA LATER TONIGHT/SUN MORNING WILL BRING GUSTY NW WINDS TO ROUGHLY 25-30KT...STRONGEST AT KCMX DUE TO FAVORABLE WIND DIRECTION AND INCREASING OVERWATER INSTABILITY UNDER INCOMING BRIEF SHOT OF COOL AIR. WITH OVERWATER INSTABILITY BECOMING SUFFICIENT FOR LAKE ENHANCEMENT...CYCLONIC FLOW AND PASSING SHORTWAVE SHOULD RESULT IN A SEVERAL HR PERIOD OF IFR CONDITIONS IN SHRA/BR AT ALL SITES LATER TONIGHT/SUN MORNING. IMPROVEMENT TO VFR EXPECTED AT KIWD/KCMX LATE MORNING/EARLY AFTN AND AT KSAW JUST AFTER THIS FCST PERIOD AS STRONG SUBSIDENCE/DRYING ARRIVE UNDER PROGRESSIVE FLOW PATTERN. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 432 PM EDT SAT AUG 4 2012 COLD FRONT PASSES ACROSS LK SUPERIOR THIS EVENING. PERIOD OF STRONG WINDS AND HIGH WAVES /LIKELY OVR 10 FEET/ EXPECTED LATE TONIGHT THROUGH MUCH OF SUNDAY AFTERNOON. EXPECT 25-30 KT WINDS FM THE NORTHWEST DURING ON SUNDAY WITH FREQUENT GALE GUSTS 35-40 KTS. A GALE WATCH HAS BEEN POSTED FOR THE EAST HALF OF LK SUPERIOR MOST OF SUNDAY. WINDS DIMINISH SUNDAY NIGHT...BUT THEN INCREASE FM THE SOUTHWEST ON MONDAY AHEAD OF A COLD FRONT THAT SLIDES THROUGH ON MONDAY NIGHT. IN WAKE OF THE FRONT...EXPECT WINDS 20 KTS OR LESS TUESDAY INTO WEDNESDAY AS HIGH PRESSURE MOVES ACROSS THE REGION. WINDS MAY END UP STRONGER THAN FCST FOR LATE THIS WEEK AS DETAILS ARE SORTED OUT REGARDING ANOTHER LOW PRESSURE SYSTEM MOVING THROUGH THE UPPER GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LSZ251- 267. GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON FOR LSZ249-250-266. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
154 PM CDT SAT AUG 4 2012 .UPDATE... 18Z AVIATION DISCUSSION ADDED BELOW. && .DISCUSSION... THE POWERFUL UPPER LEVEL SYSTEM WHICH SPARKED THE SQUALL LINE THAT MARCHED ACROSS THE REGION OVERNIGHT WILL BE RESPONSIBLE FOR A FEW MORE STORMS TODAY. IN THE WAKE OF THIS SYSTEM IS MUCH COOLER AND DRIER AIR...WHICH WILL SETTLE IN ACROSS THE UPPER MIDWEST FOR A MAJORITY OF THIS COMING WEEK. TODAY...EARLY MORNING WATER VAPOR IMAGERY WITH 500MB HEIGHTS AND WINDS SHOWED A BEAUTIFUL UPPER LEVEL WAVE SLIDING DOWN ACROSS THE DAKOTAS. THIS WAVE HAD ITS ORIGINS FROM ALBERTA CANADA...BUT THE DIFFERENCE BETWEEN THIS SYSTEM AND A TYPICAL ALBERTA CLIPPER IS THAT THIS STORM WAS ABLE TO TAP INTO THE MONSOONAL MOISTURE ASSOCIATED WITH THE SUBTROPICAL JET OFF THE SOUTHWEST US. THE COMBINATION OF THE STRONG DYNAMICAL FORCING WITH THE CANADIAN WAVE...AND THE FAVORABLE THERMODYNAMICS OF THE SUBTROPICAL AIRMASS LED TO SEVERAL AREAS OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WISCONSIN THROUGH CENTRAL NEBRASKA. THE COMBINATION OF BOTH THE PHASING OF THE SUBTROPICAL AND NORTHERN STREAM JETS...ALONG WITH THE CONTINUED BANGING ON THE TROPOSPHERIC DRUM BY REPEATED ROUNDS OF CONVECTION WILL CAUSE A +110KT JET STREAK TO FORM OVER NORTHERN MINNESOTA BY LATER THIS AFTERNOON. THE AGEOSTROPHIC DIVERGENCE IN THE RIGHT ENTRANCE REGION OF THIS JET...THE DOWNSTREAM POSITIVE VORTICITY ADVECTION ASSOCIATED WITH THE UPPER LEVEL WAVE...AND THE LOW/MID LEVEL FRONTOGENESIS WITH THE APPROACHING COLD FRONT WILL SUPPLY PLENTY OF FORCING FOR CONTINUED PRECIP THROUGH THIS MORNING AND EARLY AFTERNOON ACROSS THE SOUTHERN AND EASTERN CWA. FORECAST SOUNDINGS SHOW DEEP LAYER SPEED SHEAR FAVORABLE FOR ORGANIZED CONVECTION...BUT THE COLD AIR ADVECTION SHOULD LIMIT THE INSTABILITY AND CONFINE SEVERE POTENTIAL TO CENTRAL AND EASTERN WISCONSIN...DESPITE THE STRONG DYNAMICS. NONE THE LESS...COULD SEE A FEW STRONGER STORMS EARLIER TODAY ACROSS FAR SOUTHERN AND EASTERN MINNESOTA...AND WESTERN WISCONSIN. IN THE WAKE OF THIS FRONT...NORTHWEST WINDS WILL INCREASE ACROSS THE ALEXANDRIA/ST CLOUD AREA WITH AFTERNOON MIXING AND COLD AIR ADVECTION. TONIGHT THROUGH FRIDAY...AN UPPER LEVEL RIDGE WILL SET UP ACROSS THE 4-CORNERS REGION AND NORTHWEST FLOW WILL PREVAIL OVER THE UPPER MIDWEST. FOR SUNDAY...COOLER AIR ON THE BACK SIDE OF THE AFOREMENTIONED UPPER LEVEL WAVE WILL WRAP IN AND LIKELY BRING AN END TO THE 80 DEGREE STREAK AT MINNEAPOLIS...WITH HIGHS ONLY EXPECTED TO BE IN THE 70S REGION WIDE. A WEAK WAVE EMBEDDED IN THIS FLOW REGIME WILL TRACK ACROSS THE REGION ON MONDAY...AND COULD SEE SOME PRECIP DEVELOP ACROSS THE SOUTH LATE MONDAY ALONG AN AREA OF H850 THETA_E ADVECTION. A SIMILAR FEATURE WILL TRACK ACROSS THE REGION ON WEDNESDAY...WITH A MORE POTENT WAVE DROPPING DOWN FROM CANADA OVER LAKE SUPERIOR ON THURSDAY. HAVE SOME 20-30 POPS IN THE GRIDS TO ACCOUNT FOR THESE TWO FEATURES. TEMPERATURES WILL BE NEAR THE SEASONAL AVERAGE FOR LATE SUMMER. && .AVIATION.../18Z TAF ISSUANCE/ PRIMARY FRONT HAS JUST CLEARED EAU...WITH A SECONDARY COLD FRONT ASSOCIATED WITH THE UPPER LOW SLIDING SE ACROSS NODAK AND NW MN. BAND OF MVFR CIGS IS WORKING ACROSS WRN WI BEHIND THE FRONT AND WILL LINGER IN EAU THROUGH NO LATER THAN 20Z. COLD AIR ALOFT ASSOCIATED WITH TROUGH LEADING TO THE DEVELOPMENT OF SCT SHOWERS NW OF THE MPX AREA...THOUGH AS THE UPPER WAVE MOVES IN...EXPECT SCT SHOWERS TO REACH DOWN INTO THE AXN/STC AREAS. FEEL HRRR IS A BIT TOO AGGRESSIVE IN BRINGING SCT SHOWERS CLEAR DOWN TO THE IA BORDER. TONIGHT...AS SECONDARY COLD FRONT SWINGS THROUGH...WINDS WILL TURN NW AND WILL LIKELY COME WITH A BOUT OF MVFR CIGS...ESPECIALLY ACROSS CENTRAL MN...THOUGH MSP/RNH/EAU MAY SEE SOME MVFR CONDITIONS AS THE COLD AIR TROUGH MOVES THROUGH. AFTER THAT...WEATHER LOOKS QUITE TRANQUIL FOR SUNDAY. KMSP...ONLY A COUPLE OF MINOR THINGS TO WATCH THIS PERIOD. FIRST...WITH SECONDARY FRONT TO DROP THROUGH THIS EVENING...MAY SEE ENOUGH BACKING IN WINDS TO RESULT IN AN OCCASIONAL 250/260 DIRECTIONAL THROUGH 00Z BEFORE A MORE UNIFORM NW WINDS SETS UP THIS EVENING. THERE WILL ALSO BE THE VERY SMALL THREAT OF AN ISOLATED SHOWER AT THE AIRPORT THIS AFTERNOON...BUT BEST CHANCES SHOULD BE CLOSER TO THE COLD AIR ALOFT NW OF THE FIELD. FINALLY...PER THE RAP/NAM...EXPECT A BAND OF MVFR CIGS TO SWING ACROSS NRN/CENTRAL MN THIS EVENING...WHICH MAY BRING THE THREAT FOR AN MVFR CIG BETWEEN 5 AND 10Z BEFORE SKIES GO SKC. /OUTLOOK/ .MONDAY...VFR. WINDS SW AT 10KT. .TUESDAY...VFR. WINDS NW AT 5KT. .WEDNESDAY...VFR. WINDS SOUTH 5 KNOTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JRB/MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
1236 PM CDT SAT AUG 4 2012 .AVIATION...18Z TAFS MVFR CIGS WILL LINGER ACROSS FAR E MINNESOTA AND NW WISCONSIN THROUGH EARLY THIS AFTERNOON...INCLUDING AT KDLH/KHYR...DUE TO THE LOW STRATUS ASSOCIATED WITH A COLD FRONT THAT MOVED THROUGH THE REGION EARLIER THIS MORNING. THE VFR CONDITIONS THAT HAVE DEVELOPED ACROSS THE REST OF THE NE MINNESOTA SHOULD SPREAD INTO NW WISCONSIN THIS AFTERNOON. VFR CONDITIONS SHOULD PREDOMINATE FOR THE MID TO LATE AFTERNOON...BUT ANOTHER COLD FRONT BEGINNING TO MOVE INTO FAR NW MINNESOTA WILL BEGIN TO MOVE INTO NE MINNESOTA MID TO LATE AFTERNOON. THIS SECOND COLD FRONT WILL PROBABLY RESULT IN SCATTERED RAIN SHOWERS...AND MAYBE SOME WEAK THUNDERSHOWERS. AT THIS POINT...INCLUDED VCSH AND TEMPO OF -RA FOR KINL/KHIB/KBRD...BUT MAY NEED TO INCLUDE VCTS OR TEMPO OF -TSRA ONCE ANY STORMS MOVE INTO OR DEVELOP OVER NE MINNESOTA. ALSO...THE SHOWERS AND STORMS MAY RESULT IN BRIEF PERIODS OF MVFR CIGS AND VSBYS. WESTERLY WINDS OF 10 TO 15 KNOTS WITH GUSTS UP TO 25 KNOTS ARE GENERALLY EXPECTED THROUGH EARLY THIS EVENING AT ALL TERMINALS...WITH WINDS RELAXING AND BECOMING NORTHWESTERLY TONIGHT. MVFR CIGS WILL PROBABLY REAPPEAR THIS THIS EVENING IN THE WAKE OF THE COLD FRONT...BUT CLEAR SKIES SHOULD DEVELOP LATE TONIGHT. && .PREV DISCUSSION... /ISSUED 933 AM CDT SAT AUG 4 2012/ UPDATE... SPREAD SCATTERED SHOWERS FURTHER WEST AND DE-EMPHASIZED THUNDER ACROSS THE AREA THIS MORNING. DECREASED WINDS A LITTLE THIS MORNING. SHORT TERM... THE ACTUAL FRONT IS MOVING THROUGH THE DULUTH AREA MID-MORNING THIS MORNING. IT IS BECOMING A STRONG FRONT...WITH THE UPPER FLOW AND THERMAL WIND LINING UP MORE AND MORE PARALLEL TO IT. THIS SLOWS DOWN ITS FORWARD PROGRESS AND INCREASES MOISTURE AND CAUSES PRECIPITATION TO FILL IN BEHIND IT. BRIEF SURFACE RIDGING BEHIND THE FRONT IS FOLLOWED BY THE TROUGH THAT REFLECTS FALLING HEIGHTS ALOFT. WE LEFT IN SHOWERS AND DID NOT DE-EMPHASIZE THUNDERSTORMS THIS AFTERNOON INTO THE EVENING...THUNDERSTORMS WILL BE SHALLOW... BRIEF...AND SPOTTY IN DISTRIBUTION. SOUTHWEST WINDS WILL COME UP A LITTLE LATER...AS THE SECOND TROUGH APPROACHES...AND SLOWLY VEER. PREV DISCUSSION... /ISSUED 631 AM CDT SAT AUG 4 2012/ AVIATION...12Z TAFS. FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z. PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/ SHORT TERM...THROUGH SUNDAY. CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3 HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST. THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF HIGHEST MOISTURE/AND NEAREST THE UPPER LOW. IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN. TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY. AVIATION...06Z ISSUANCE WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z. && .POINT TEMPS/POPS... DLH 53 76 55 83 / 20 10 0 10 INL 45 77 54 80 / 40 10 0 20 BRD 53 77 53 85 / 10 10 0 10 HYR 54 76 50 84 / 10 10 0 10 ASX 55 77 54 82 / 20 10 0 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...EOM LONG TERM....GROCHOCINSKI AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
554 PM CDT Sat Aug 4 2012 ...UPDATED AVIATION DISCUSSION... .DISCUSSION... Well, looks like we have to wait for rain again. At least in many areas this seems to be the appropriate theme for today, as yet another shortwave/MCV race ahead of the surface front this morning effectively shoving stabilizing much of northern Missouri and allowing a weak surface trough to sneak southeast into Missouri and Kansas. Currently the primary surface trough stretches from Ottumwa, IA southwest through Kansas City and further south towards Wichita, KS. A continued stream of mid-level strato-cu has suppressed the warm surface temperatures in the extreme southern CWA with 88D radar composites indicating northward extent of surface warm front is just south of the Pleasant Hill office. For tonight, highest convective potential remains along our southern and southeastern tier of counties and again in areas near Kirksville as mid-level shortwave currently moving through central Kansas reaches the area after 4pm. HRRR and RAP suggest widely scattered convection forming along the differential heating axis in the southern CWA after 4pm with this convection slowly sinking southeast this evening. Instability and shear plots indicate multi-cell clusters would be the preferred storm type with downburst winds the main threat. Elsewhere in areas further north, scattered high based showers or sprinkles may the result of the weak shortwave and 850 trough passing through the area this evening. Dew points will remain elevated through the evening as true front is just arriving into the northwest corner of the CWA. Will linger chc pops across the southern CWA through the overnight hours, as 850 mb front stalls. Weak 850:700 mb frontogenesis tied with the right entrance region of the upr jet may be enough forcing for west to east ling of elevated convection through early Sunday morning in west central into central MO. Sunday-Monday: Surface high pressure will drift southeast into the region by Sunday morning. North to northeast winds will prevail through the daytime hours with temperatures struggling to reach the middle 80s in northern MO and barely hitting 90 towards east central Kansas and central MO. This surface ridge will quickly slide into the Ohio river valley by Monday allowing winds to take a more southerly track. The resultant bump in low-level temperatures will push daytime highs in the lower to middle 90s. Tuesday-Friday: The overall longwave pattern will feature a building ridge over the western CONUS and broad northwesterly flow over the central and eastern US. GFS/EC/GEM indicate a weak disturbance in the NW flow pattern moving through as we reach Tuesday night into Wednesday. Always hard to time these shortwaves and their impact especially considering the lack of boundary layer moisture. However one could justify at least a slight chance for precip. Temperatures will run near or slightly above normal through the end of the week. 31 && .AVIATION... VFR conditions expected for all terminals through the forecast period. Widely scattered showers continue to move across the area this evening but should push east of the TAF sites in a few hours. Otherwise, light north winds are expected to persist through tomorrow. Deroche && .EAX WATCHES/WARNINGS/ADVISORIES... MO...HEAT ADVISORY until 8 PM CDT this evening FOR MOZ040-043>046-053- 054. KS...HEAT ADVISORY until 8 PM CDT this evening FOR KSZ057-060. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
323 PM CDT Sat Aug 4 2012 .DISCUSSION... Well, looks like we have to wait for rain again. At least in many areas this seems to be the appropriate theme for today, as yet another shortwave/MCV race ahead of the surface front this morning effectively shoving stabilizing much of northern Missouri and allowing a weak surface trough to sneak southeast into Missouri and Kansas. Currently the primary surface trough stretches from Ottumwa, IA southwest through Kansas City and further south towards Wichita, KS. A continued stream of mid-level strato-cu has suppressed the warm surface temperatures in the extreme southern CWA with 88D radar composites indicating northward extent of surface warm front is just south of the Pleasant Hill office. For tonight, highest convective potential remains along our southern and southeastern tier of counties and again in areas near Kirksville as mid-level shortwave currently moving through central Kansas reaches the area after 4pm. HRRR and RAP suggest widely scattered convection forming along the differential heating axis in the southern CWA after 4pm with this convection slowly sinking southeast this evening. Instability and shear plots indicate multi-cell clusters would be the preferred storm type with downburst winds the main threat. Elsewhere in areas further north, scattered high based showers or sprinkles may the result of the weak shortwave and 850 trough passing through the area this evening. Dew points will remain elevated through the evening as true front is just arriving into the northwest corner of the CWA. Will linger chc pops across the southern CWA through the overnight hours, as 850 mb front stalls. Weak 850:700 mb frontogenesis tied with the right entrance region of the upr jet may be enough forcing for west to east ling of elevated convection through early Sunday morning in west central into central MO. Sunday-Monday: Surface high pressure will drift southeast into the region by Sunday morning. North to northeast winds will prevail through the daytime hours with temperatures struggling to reach the middle 80s in northern MO and barely hitting 90 towards east central Kansas and central MO. This surface ridge will quickly slide into the Ohio river valley by Monday allowing winds to take a more southerly track. The resultant bump in low-level temperatures will push daytime highs in the lower to middle 90s. Tuesday-Friday: The overall longwave pattern will feature a building ridge over the western CONUS and broad northwesterly flow over the central and eastern US. GFS/EC/GEM indicate a weak disturbance in the NW flow pattern moving through as we reach Tuesday night into Wednesday. Always hard to time these shortwaves and their impact especially considering the lack of boundary layer moisture. However one could justify at least a slight chance for precip. Temperatures will run near or slightly above normal through the end of the week. 31 && .AVIATION... For the 18Z TAFs...Quick progression of a cold front across Missouri has resulted in winds at the terminals turning to the northeast in the wake of some scattered convection this morning. Further thunderstorm development might occur across northern and central Missouri this afternoon, but at this time thoughts are this activity will be east of all the terminals. As a result, only issue to watch for looks to be the slightly gusty north winds this afternoon in the post-frontal environment. Winds should stay from the north overnight, with VFR skies prevailing. Cutter && .EAX WATCHES/WARNINGS/ADVISORIES... MO...HEAT ADVISORY until 8 PM CDT this evening FOR MOZ040-043>046-053- 054. KS...HEAT ADVISORY until 8 PM CDT this evening FOR KSZ057-060. && $$ WFO EAX
AREA FORECAST DISCUSSION...CORRECTED
NWS HASTINGS NE
406 PM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH SUNDAY AFTERNOON. PRIMARY ISSUES THROUGH THE NEXT 24 HOURS INCLUDE TIMING THE THE LAST FEW HOURS OF LINGERING ISOLATED/SCATTERED LIGHT PRECIP THROUGH LATE AFTERNOON...FOLLOWED BY JUST HOW COOL WILL IT GET TONIGHT. 19Z OBJECTIVE SURFACE ANALYSIS CENTERS A 1022MB HIGH OVER MT/WY...WITH THE RIDGE AXIS EXTENDING DOWN INTO WESTERN NEB. THE MUCH-AWAITED STRONGEST COLD FRONT WE HAVE SEEN AWHILE HAS PUSHED WELL OFF TO THE SOUTH AND EAST...NOW ALIGNED ALONG FROM EASTERN IA TO THE TX PANHANDLE. ALTHOUGH MID AFTERNOON WINDS CONTINUE TO GUST OVER 20 MPH IN MANY AREAS FROM THE NORTH/NORTHWEST...THEY ARE STARTING A GRADUAL DECLINE AS THE STRONGEST PRESSURE RISES SLIDE SOUTHEAST WITH THE FRONT. RADAR IMAGERY AND VISIBLE SATELLITE AROUND 1930Z GENERALLY CONFIRM THE EARLIER EXPECTATIONS OF ISOLATED/SCATTERED MAINLY LIGHT HIGH BASED RAIN SHOWERS STARTING TO INCREASE IN COVERAGE A BIT ACROSS THE SOUTHERN 1/2 OF THE CWA...ALTHOUGH NO LIGHTNING STRIKES HAVE YET BEEN DETECTED. WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL A SEASONABLY STRONG MID LEVEL VORT MAX TRACKING EAST NEAR FAR NORTHERN MN...WITH THE 500MB SHORTWAVE AXIS TRAILING SOUTHWEST TO THE LOCAL AREA...WHILE RIDGING DOMINATES THE SOUTH CENTRAL AND WEST CENTRAL CONUS. TEMP WISE THIS AFTERNOON...STILL ANTICIPATING SOME LATE DAY SUNSHINE TO BOOST AT LEAST MUCH OF THE NORTHWEST 1/2 OF THE CWA INTO THE LOW 80S...BUT THE JURY IS STILL OUT ON WHETHER PARTS OF THE SOUTHEAST...MAYBE EVEN HASTINGS...WILL EVEN MAKE IT TO 80 GIVEN THE EXTENSIVE MID CLOUDS LINGERING LONGER. SEASONABLY DRY AIR IN THE FORM OF MID 40S-LOW 50S DEWPOINTS CONTINUE TO INVADE MUCH OF THE CWA FROM THE NORTHWEST...ALTHOUGH SOME UPPER 50S ARE STILL HANGING ON IN THE SOUTHEAST. STARTING OFF WITH THE NEXT FEW HOURS THROUGH 00Z...JUST MADE A LAST MINUTE DECISION TO PULL THUNDER MENTION ALTOGETHER...AS LATEST HOURLY MESOANALYSIS AND RAP INSTABILITY PROGS INDICATE BARELY EVEN 100 J/KG MUCAPE REMAINING IN THE FAR SOUTHEAST COUNTIES...AND ONGOING LIGHT SHOWERS HAVE NOT EXHIBITED DETECTABLE LIGHTNING AT ALL OVER THE PAST FEW HOURS. THESE LINGERING SHOWERS OVER THE NEXT FEW HOURS WILL MAINLY AFFECT LIMITED AREAS SOUTHEAST OF A LINE FROM HEBRON-STOCKTON...AND WILL CARRY ISOLATED/SCATTERED SHOWER WORDING FOR JUST A FEW MORE HOURS TO COVER THEM. THIS LINGERING PRECIP IS CLEARLY TIED TO A QUICKLY DEPARTING MID LEVEL CONVERGENCE/FRONTOGENETIC ZONE EVIDENT AT 700MB. GETTING TO THE OFFICIAL NIGHT PERIOD 00Z-12Z...BY THE START OF THE EVENING ANTICIPATE CONSIDERABLE CLEAR SKIES NEARLY CWA-WIDE...AS THE BACK EDGE OF THE PRIMARY MID DECK AND ASSOCIATED SHOWERS/POSSIBLE WEAK STORMS SHOULD BE JUST OFF TO THE SOUTH/EAST OF THE CWA BY THEN. AS A RESULT...HAVE ESSENTIALLY ZERO POPS THROUGH THE NIGHT AREA- WIDE...AS THE TRAILING SOUTHWEST PORTION OF THE POTENT MID LEVEL WAVE CONTINUES EXITING STAGE RIGHT...REACHING AN AXIS FROM NORTHERN WI TO IL BY 12Z. IN ITS WAKE...A PLEASANT AND EVEN SEASONABLY COOL NIGHT WILL SETTLE INTO THE CENTRAL PLAINS. AT THE SURFACE...NORTH BREEZES WILL REALLY LIGHTEN BY SUNSET...AND BECOME NEARLY CALM THROUGH THE NIGHT IN SOME AREAS AS A 1023MB HIGH PRESSURE AXIS CENTERS ITSELF DIRECTLY OVER THE AREA. THE COMBINATION OF THE INVADING DRY AIR...CLEARING SKIES AND LIGHT BREEZES SHOULD SET THE STAGE FOR A RATHER COOL NIGHT BY EARLY AUG STANDARDS. LEANED TOWARD THE LOWER END OF 12Z MET/MAV GUIDANCE FOR LOWS...WHICH RESULTED IN LOWERING PREVIOUS FORECAST BY 2-4 DEGREES MAINLY IN THE FAR NORTHWEST AND SOUTHERN COUNTIES. THEREFORE...AM NOW ADVERTISING LOW-MID 50S ALL AREAS...WITH TYPICAL COOLER SPOTS SUCH AS ORD AND THE PLATTE VALLEY OF WESTERN DAWSON COUNTY VERY POSSIBLY TAGGING UPPER 40S. FOR THIS TIME OF YEAR...DEFINITELY LIGHT JACKET WEATHER FOR THOSE OUT AND ABOUT LATE TONIGHT/EARLY SUNDAY MORNING. FOR THE SUNDAY DAYTIME 12Z-00Z PERIOD...LITERALLY KEPT POPS ZEROED OUT CWA-WIDE...AS A BANNER DAY WITH VERY LITTLE...IF ANY CLOUDS IS FORECAST. IN THE MID-UPPER LEVELS...THE DEPARTING SHORTWAVE WILL REACH ALL THE WAY TO THE EASTERN GREAT LAKES BY LATE AFTERNOON...WHILE THE SOUTHERN CONUS 500MB RIDGE AXIS EXPANDS NORTH AND WEST IN COVERAGE A BIT...BECOMING CENTERED FROM CO/UT TO OK/NORTHERN TX. THIS WILL LEAVE THE CWA IN FAIRLY LIGHT AND VERY DRY WEST-NORTHWEST MID LEVEL FLOW. AT THE SURFACE...THE AFOREMENTIONED RIDGE AXIS WILL START OUT CENTERED OVER THE AREA...BUT GRADUALLY SLIDE EAST TO NEAR THE MO RIVER BY LATE AFTERNOON. AS THE HIGH EDGES EAST...LIGHT SOUTHERLY BREEZES WILL GRADUALLY OVERTAKE MUCH OF THE CWA FROM WEST TO EAST...EVENTUALLY REACHING INTO THE 10-15 MPH RANGE IN FAR WESTERN COUNTIES...BUT REMAINING VERY LIGHT/NEAR CALM ALL DAY IN THE FAR EAST NEAR HWY 81. ALTHOUGH THE LIGHT BREEZES/LACK OF MIXING WILL WORK AGAINST MUCH OF A WARMUP OVER TODAY...PLENTIFUL SUNSHINE AND RELATIVELY DRY AIR WILL WORK IN FAVOR OF IT. AS HAS BEEN THE CASE FOR SEVERAL WEEKS NOW...NUMERICAL GUIDANCE HAS PROVEN DIFFICULT TO EMPLOY...WITH THE MET AVERAGING TOO WARM AND THE MAV TOO COOL. OVERALL THOUGH...WILL LEAN TOWARD THE WARMER END OF GUIDANCE...AND ESSENTIALLY JUST BUMPED UP THE PREVIOUS FORECAST 1 DEGREE. THIS YIELDS NEAR NORMAL HIGHS OF 86-88 MOST AREAS...AND 90-92 IN KS ZONES AND FURNAS COUNTY AREA. LOWERED DEWPOINTS A BIT FROM PREVIOUS FORECAST AS WELL...WITH ONLY MID-UPPER 40S SOUTHWEST AND LOW-MID 50S SOUTHEAST. ALTHOUGH RELATIVE HUMIDITY VALUES COULD DROP CLOSE TO THE 20 PERCENT CRITICAL FIRE WEATHER THRESHOLD IN A FEW FAR SOUTHWEST COUNTIES...WINDS SPEEDS WILL FALL WELL SHORT OF FIRE WEATHER CRITERIA. .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. MODELS NOT IN TOO BAD OF AGREEMENT TO START OFF THE LONG TERM PERIOD...SHOWING SUNDAY EVENING REMAINING UNDER ZONAL/WEAK NORTHWESTERLY FLOW IN THE UPPER LEVELS...A RESULT OF A BROAD HIGH PRESSURE IN PLACE ACROSS THE SCENTRAL/SWRN CONUS AND A TROUGH SHIFTING TOWARD THE EAST COAST. DURING THE OVERNIGHT HOURS...THE FLOW DOES AMPLIFY SOME AS ANOTHER TROUGH IS MAKING ITS WAY TOWARD THE WEST COAST...BUT NO NOTABLE DISTURBANCES LOOK TO MOVE THROUGH AND DECIDED TO KEEP THE FORECAST DRY. HOWEVER...MODELS DO SHOW THE SFC/LOWER LEVEL WINDS REMAINING S/SWRLY OVERNIGHT...WITH INCREASING VALUES OF ELEVATED INSTABILITY SHIFTING NORTH INTO THE REGION AS A STRONGER /30-35KT OR SO/ LLJ DEVELOPS...MAINLY ACROSS THE HIGH PLAINS REGION. THE EDGE OF THIS LLJ/INSTABILITY AXIS DOES LIE OVER THE WRN PORTIONS OF THE CWA...AND MAY HAVE TO KEEP AN EYE ON THIS AREA FOR THE POTENTIAL FOR PERHAPS SOME LIGHT PRECIP /BUT FORECAST SOUNDINGS ARE PRETTY DRY IN THE LOWER LEVELS/...OR A LITTLE MORE IN THE WAY OF CLOUD COVER. INTO MONDAY/MONDAY NIGHT...THE MAIN STORY LIES WITH THE ARRIVAL OF A MID/UPPER LEVEL WAVE...ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED UP NEAR THE HUDSON BAY. KEPT THE DAYTIME HOURS ON MONDAY DRY...THOUGH A LITTLE MORE UNCERTAINTY ARISES TOWARD THE LATE AFTERNOON HOURS...WITH THE ACCOMPANYING SURFACE FRONTAL BOUNDARY LOOKS TO BE KNOCKING ON THE DOOR OF THE FAR NW CORNER OF THE CWA. DID RAISE POPS A BIT DURING THE EVENING/OVERNIGHT HOURS ACROSS THE N/NWRN PORTIONS OF THE CWA...BUT DIDNT MAKE MUCH CHANGE FURTHER SOUTH. AHEAD OF THE FRONT ON MONDAY...EXPECTING INCREASED SOUTHERLY WINDS...LIKELY A BIT GUSTY DURING THE AFTERNOON...AND WARMER TEMPERATURES WITH HIGHS FORECAST TO REACH INTO THE MID/UPPER 90S FOR MUCH/IF NOT ALL OF THE CWA. CONDITIONS DURING THE AFTERNOON HOURS SHOULD REMAIN BELOW CRITICAL FIRE LEVELS...RHS COULD DROP INTO THE LOWER/MID 20S ACROSS THE SOUTH...BUT SUSTAINED WIND SPEEDS ARE EXPECTED TO REMAIN <20 MPH...THOUGH GUSTS COULD AT TIMES COME CLOSE TO 25 MPH. WILL BE SOMETHING TO KEEP AN EYE ON IF MODELS HAPPEN TO TREND UP WINDS/TREND DOWN DPS. KEPT SOME LINGERING POPS IN DURING THE DAY ON TUESDAY...MAINLY ACROSS THE SRN HALF OF THE CWA...IN CLOSER PROXIMITY TO WHERE THE SFC BOUNDARY IS EXPECTED TO BE /SOMEWHERE NEAR OR SOUTH OF THE NEB AND KS STATE LINE/. CONFIDENCE NOT THE HIGHEST...AS THE PLACEMENT OF THE FRONT WILL BE DEPENDENT ON HOW THINGS PAN OUT MONDAY NIGHT. WITH MOST OF THE CWA LOOKING TO BE ON THE NORTH SIDE OF THAT BOUNDARY...MORE EASTERLY WINDS EXPECTED TO BE IN PLACE...AND FORECAST HIGHS ARE A TOUCH COOLER THAN MONDAY...MORE IN THE LOWER/MID 90S. BY 00Z WEDNESDAY...THE UPPER LEVEL PATTERN ACROSS THE CONUS HAS BECOME MORE AMPLIFIED...WITH MORE SOLIDLY NORTHWESTERLY FLOW IN PLACE ACROSS THE REGION AS THE RIDGE AXIS EXTENDS FROM THE DESERT SW THROUGH THE ROCKIES AND INTO CANADA. THE NOSE OF AN UPPER LEVEL JET STREAK ROUNDING THE TOP OF THE RIDGE AXIS IS EXPECTED TO SHIFT INTO THE REGION FROM THE NW...BRINGING THE POTENTIAL FOR MORE PRECIPITATION TUESDAY EVENING/OVERNIGHT. SIMILAR TO MONDAY/MONDAY NIGHT...WHILE THERE IS INSTABILITY IN PLACE ACROSS THE REGION...OVERALL DEEP LAYER SHEAR IS CERTAINLY NOT OUTSTANDING...GENERALLY TOPPING OUT IN THE 25-30 KTS RANGE...SO WHILE SOME THUNDERSTORMS COULD BE ON THE STRONGER SIDE...NOT EXPECTING SEVERE WEATHER AT THIS POINT. INTO WEDNESDAY...MODELS CONTINUE TO SHOW THE NOSE OF THIS UPPER LEVEL JET IN THE AREA...AND DECIDED TO KEEP SOME LINGERING POPS IN THE AREA...BUT CONFIDENCE IN CHANCES STICKING AROUND LONGER THAN PERHAPS A FEW HOURS IN THE MORNING NOT EXACTLY HIGH. THAT LOWER CONFIDENCE CONTINUES RIGHT ON THROUGH THE REMAINDER OF THE LONG TERM PERIOD. THE UPPER LEVEL PATTERN REMAINS NORTHWESTERLY ACROSS THE REGION WITH THE RIDGE STAYING IN PLACE OVER THE CENTRAL ROCKIES...AND KEPT THE FORECAST DRY AT THIS POINT...WITH MODELS SHOWING SOME DIFFERENCES WITH DISTURBANCES PASSING TO THE EAST OF THE CWA...AND WHETHER WE SEE ANY PRECIP AS RESULT. WITH THE RIDGE/WARMEST AIR REMAINING OFF TO THE WEST OF THE CWA...AND THE POTENTIAL FOR AN ADDITIONAL FRONTAL PASSAGE...NOTABLY HIGHER TEMPERATURES ARE NOT EXPECTED...WITH FORECAST HIGHS RANGING FROM ROUGHLY THE MID 90S WED/THUR TO THE MID 80S TO LOWER 90S FRI/SAT. && .PREV DISCUSSION... /ISSUED 1155 AM CDT SAT AUG 4 2012/ AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY ARE FORECAST THROUGH THE PERIOD. ESSENTIALLY CLEAR SKIES WILL DOMINATE THE AREA THROUGH THE MAJORITY OF THE PERIOD...BUT FOR AT LEAST THE INITIAL 3-5 HOURS QUITE A BIT OF MID LEVEL CLOUD COVER WILL STREAM OVER...ALONG WITH JUST A SLIGHT CHANCE OF BRIEF PASSING SHOWERS...WHICH HAVE BEEN SUGGESTED WITH A VICINITY SHOWER MENTION. SURFACE BREEZES WILL REMAIN NORTHERLY THROUGH TONIGHT IN THE WAKE OF A SEASONABLY STRONG COLD FRONT. THE STRONGEST SPEEDS WITH GUST POTENTIAL TO AROUND 20KT WILL OCCUR DURING THE FIRST FEW HOURS OF THE PERIOD...BEFORE A STEADY SLACKENING OF SPEEDS COMMENCES. FROM SUNSET THROUGH MID-DAY SUNDAY...SPEEDS SHOULD AVERAGE UNDER 6KT AND BECOME A BIT VARIABLE IN DIRECTION WITH TIME. && .CLIMATE...TODAY/TONIGHT WILL LIKELY END UP BEING THE COOLEST DAY/NIGHT AT GRAND ISLAND AND HASTINGS IN 6.5 WEEKS. BASED ON FORECAST PROJECTIONS OVER THE NEXT FEW HOURS...THE CALENDAR DAY HIGH TEMPERATURE AT BOTH GRAND ISLAND AND HASTINGS WILL END UP SOMEWHERE BETWEEN 78-82 DEGREES...BUT IS GUARANTEED TO BE AT LEAST 78 BECAUSE THIS VALUE WAS REACHED SHORTLY AFTER MIDNIGHT BEFORE THE COLD FRONT INVADED. FOR GRAND ISLAND...A HIGH OF 79-82 DEGREES WOULD RESULT IN THE COOLEST DAILY HIGH SINCE JUNE 20TH...WHEN IT TOPPED OUT AT 79. FOR HASTINGS...A HIGH OF 78-79 DEGREES WOULD ALSO RESULT IN THE COOLEST DAY SINCE JUNE 20TH...WHEN IT REACHED 78. TURNING TO LOW TEMPERATURES TONIGHT...THE CURRENT FORECAST FOR BOTH GRAND ISLAND AND HASTINGS CALLS FOR 55. THIS IS ONLY 3 DEGREES ABOVE HASTINGS AUGUST 5TH RECORD LOW OF 52...AND 4 DEGREES ABOVE THE GRAND ISLAND RECORD LOW OF 51...BOTH SET IN 1994. ASSUMING IT DIPS TO AT LEAST 57 DEGREES OVERNIGHT...THIS WILL BE THE COOLEST LOW TEMP IN BOTH CITIES SINCE JUNE 21ST...WHEN GRAND ISLAND BOTTOMED OUT AT 52 AND HASTINGS 51. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM/AVIATION...PFANNKUCH LONG TERM...ADO
AREA FORECAST DISCUSSION
NWS HASTINGS NE
400 PM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH SUNDAY AFTERNOON. PRIMARY ISSUES THROUGH THE NEXT 24 HOURS INCLUDE TIMING THE THE LAST FEW HOURS OF LINGERING ISOLATED/SCATTERED LIGHT PRECIP THROUGH LATE AFTERNOON...FOLLOWED BY JUST HOW COOL WILL IT GET TONIGHT. 19Z OBJECTIVE SURFACE ANALYSIS CENTERS A 1022MB HIGH OVER MT/WY...WITH THE RIDGE AXIS EXTENDING DOWN INTO WESTERN NEB. THE MUCH-AWAITED STRONGEST COLD FRONT WE HAVE SEEN AWHILE HAS PUSHED WELL OFF TO THE SOUTH AND EAST...NOW ALIGNED ALONG FROM EASTERN IA TO THE TX PANHANDLE. ALTHOUGH MID AFTERNOON WINDS CONTINUE TO GUST OVER 20 MPH IN MANY AREAS FROM THE NORTH/NORTHWEST...THEY ARE STARTING A GRADUAL DECLINE AS THE STRONGEST PRESSURE RISES SLIDE SOUTHEAST WITH THE FRONT. RADAR IMAGERY AND VISIBLE SATELLITE AROUND 1930Z GENERALLY CONFIRM THE EARLIER EXPECTATIONS OF ISOLATED/SCATTERED MAINLY LIGHT HIGH BASED RAIN SHOWERS STARTING TO INCREASE IN COVERAGE A BIT ACROSS THE SOUTHERN 1/2 OF THE CWA...ALTHOUGH NO LIGHTNING STRIKES HAVE YET BEEN DETECTED. WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL A SEASONABLY STRONG MID LEVEL VORT MAX TRACKING EAST NEAR FAR NORTHERN MN...WITH THE 500MB SHORTWAVE AXIS TRAILING SOUTHWEST TO THE LOCAL AREA...WHILE RIDGING DOMINATES THE SOUTH CENTRAL AND WEST CENTRAL CONUS. TEMP WISE THIS AFTERNOON...STILL ANTICIPATING SOME LATE DAY SUNSHINE TO BOOST AT LEAST MUCH OF THE NORTHWEST 1/2 OF THE CWA INTO THE LOW 80S...BUT THE JURY IS STILL OUT ON WHETHER PARTS OF THE SOUTHEAST...MAYBE EVEN HASTINGS...WILL EVEN MAKE IT TO 80 GIVEN THE EXTENSIVE MID CLOUDS LINGERING LONGER. SEASONABLY DRY AIR IN THE FORM OF MID 40S-LOW 50S DEWPOINTS CONTINUE TO INVADE MUCH OF THE CWA FROM THE NORTHWEST...ALTHOUGH SOME UPPER 50S ARE STILL HANGING ON IN THE SOUTHEAST. STARTING OFF WITH THE NEXT FEW HOURS THROUGH 00Z...JUST MADE A LAST MINUTE DECISION TO PULL THUNDER MENTION ALTOGETHER...AS LATEST HOURLY MESOANALYSIS AND RAP INSTABILITY PROGS INDICATE BARELY EVEN 100 J/KG MUCAPE REMAINING IN THE FAR SOUTHEAST COUNTIES...AND ONGOING LIGHT SHOWERS HAVE NOT EXHIBITED DETECTABLE LIGHTNING AT ALL OVER THE PAST FEW HOURS. THESE LINGERING SHOWERS OVER THE NEXT FEW HOURS WILL MAINLY AFFECT LIMITED AREAS SOUTHEAST OF A LINE FROM HEBRON-STOCKTON...AND WILL CARRY ISOLATED/SCATTERED SHOWER WORDING FOR JUST A FEW MORE HOURS TO COVER THEM. THIS LINGERING PRECIP IS CLEARLY TIED TO A QUICKLY DEPARTING MID LEVEL CONVERGENCE/FRONTOGENETIC ZONE EVIDENT AT 700MB. GETTING TO THE OFFICIAL NIGHT PERIOD 00Z-12Z...BY THE START OF THE EVENING ANTICIPATE CONSIDERABLE CLEAR SKIES NEARLY CWA-WIDE...AS THE BACK EDGE OF THE PRIMARY MID DECK AND ASSOCIATED SHOWERS/POSSIBLE WEAK STORMS SHOULD BE JUST OFF TO THE SOUTH/EAST OF THE CWA BY THEN. AS A RESULT...HAVE ESSENTIALLY ZERO POPS THROUGH THE NIGHT AREA- WIDE...AS THE TRAILING SOUTHWEST PORTION OF THE POTENT MID LEVEL WAVE CONTINUES EXITING STAGE RIGHT...REACHING AN AXIS FROM NORTHERN WI TO IL BY 12Z. IN ITS WAKE...A PLEASANT AND EVEN SEASONABLY COOL NIGHT WILL SETTLE INTO THE CENTRAL PLAINS. AT THE SURFACE...NORTH BREEZES WILL REALLY LIGHTEN BY SUNSET...AND BECOME NEARLY CALM THROUGH THE NIGHT IN SOME AREAS AS A 1023MB HIGH PRESSURE AXIS CENTERS ITSELF DIRECTLY OVER THE AREA. THE COMBINATION OF THE INVADING DRY AIR...CLEARING SKIES AND LIGHT BREEZES SHOULD SET THE STAGE FOR A RATHER COOL NIGHT BY EARLY AUG STANDARDS. LEANED TOWARD THE LOWER END OF 12Z MET/MAV GUIDANCE FOR LOWS...WHICH RESULTED IN LOWERING PREVIOUS FORECAST BY 2-4 DEGREES MAINLY IN THE FAR NORTHWEST AND SOUTHERN COUNTIES. THEREFORE...AM NOW ADVERTISING LOW-MID 50S ALL AREAS...WITH TYPICAL COOLER SPOTS SUCH AS ORD AND THE PLATTE VALLEY OF WESTERN DAWSON COUNTY VERY POSSIBLY TAGGING UPPER 40S. FOR THIS TIME OF YEAR...DEFINITELY LIGHT JACKET WEATHER FOR THOSE OUT AND ABOUT LATE TONIGHT/EARLY SUNDAY MORNING. FOR THE SUNDAY DAYTIME 12Z-00Z PERIOD...LITERALLY KEPT POPS ZEROED OUT CWA-WIDE...AS A BANNER DAY WITH VERY LITTLE...IF ANY CLOUDS IS FORECAST. IN THE MID-UPPER LEVELS...THE DEPARTING SHORTWAVE WILL REACH ALL THE WAY TO THE EASTERN GREAT LAKES BY LATE AFTERNOON...WHILE THE SOUTHERN CONUS 500MB RIDGE AXIS EXPANDS NORTH AND WEST IN COVERAGE A BIT...BECOMING CENTERED FROM CO/UT TO OK/NORTHERN TX. THIS WILL LEAVE THE CWA IN FAIRLY LIGHT AND VERY DRY WEST-NORTHWEST MID LEVEL FLOW. AT THE SURFACE...THE AFOREMENTIONED RIDGE AXIS WILL START OUT CENTERED OVER THE AREA...BUT GRADUALLY SLIDE EAST TO NEAR THE MO RIVER BY LATE AFTERNOON. AS THE HIGH EDGES EAST...LIGHT SOUTHERLY BREEZES WILL GRADUALLY OVERTAKE MUCH OF THE CWA FROM WEST TO EAST...EVENTUALLY REACHING INTO THE 10-15 MPH RANGE IN FAR WESTERN COUNTIES...BUT REMAINING VERY LIGHT/NEAR CALM ALL DAY IN THE FAR EAST NEAR HWY 81. ALTHOUGH THE LIGHT BREEZES/LACK OF MIXING WILL WORK AGAINST MUCH OF A WARMUP OVER TODAY...PLENTIFUL SUNSHINE AND RELATIVELY DRY AIR WILL WORK IN FAVOR OF IT. AS HAS BEEN THE CASE FOR SEVERAL WEEKS NOW...NUMERICAL GUIDANCE HAS PROVEN DIFFICULT TO EMPLOY...WITH THE MET AVERAGING TOO WARM AND THE MAV TOO COOL. OVERALL THOUGH...WILL LEAN TOWARD THE WARMER END OF GUIDANCE...AND ESSENTIALLY JUST BUMPED UP THE PREVIOUS FORECAST 1 DEGREE. THIS YIELDS NEAR NORMAL HIGHS OF 86-88 MOST AREAS...AND 90-92 IN KS ZONES AND FURNAS COUNTY AREA. LOWERED DEWPOINTS A BIT FROM PREVIOUS FORECAST AS WELL...WITH ONLY MID-UPPER 40S SOUTHWEST AND LOW-MID 50S SOUTHEAST. ALTHOUGH RELATIVE HUMIDITY VALUES COULD DROP CLOSE TO THE 20 PERCENT CRITICAL FIRE WEATHER THRESHOLD IN A FEW FAR SOUTHWEST COUNTIES...WINDS SPEEDS WILL FALL WELL SHORT OF FIRE WEATHER CRITERIA. .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. MODELS NOT IN TOO BAD OF AGREEMENT TO START OFF THE LONG TERM PERIOD...SHOWING SUNDAY EVENING REMAINING UNDER ZONAL/WEAK NORTHWESTERLY FLOW IN THE UPPER LEVELS...A RESULT OF A BROAD HIGH PRESSURE IN PLACE ACROSS THE SCENTRAL/SWRN CONUS AND A TROUGH SHIFTING TOWARD THE EAST COAST. DURING THE OVERNIGHT HOURS...THE FLOW DOES AMPLIFY SOME AS ANOTHER TROUGH IS MAKING ITS WAY TOWARD THE WEST COAST...BUT NO NOTABLE DISTURBANCES LOOK TO MOVE THROUGH AND DECIDED TO KEEP THE FORECAST DRY. HOWEVER...MODELS DO SHOW THE SFC/LOWER LEVEL WINDS REMAINING S/SWRLY OVERNIGHT...WITH INCREASING VALUES OF ELEVATED INSTABILITY SHIFTING NORTH INTO THE REGION AS A STRONGER /30-35KT OR SO/ LLJ DEVELOPS...MAINLY ACROSS THE HIGH PLAINS REGION. THE EDGE OF THIS LLJ/INSTABILITY AXIS DOES LIE OVER THE WRN PORTIONS OF THE CWA...AND MAY HAVE TO KEEP AN EYE ON THIS AREA FOR THE POTENTIAL FOR PERHAPS SOME LIGHT PRECIP /BUT FORECAST SOUNDINGS ARE PRETTY DRY IN THE LOWER LEVELS/...OR A LITTLE MORE IN THE WAY OF CLOUD COVER. INTO MONDAY/MONDAY NIGHT...THE MAIN STORY LIES WITH THE ARRIVAL OF A MID/UPPER LEVEL WAVE...ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED UP NEAR THE HUDSON BAY. KEPT THE DAYTIME HOURS ON MONDAY DRY...THOUGH A LITTLE MORE UNCERTAINTY ARISES TOWARD THE LATE AFTERNOON HOURS...WITH THE ACCOMPANYING SURFACE FRONTAL BOUNDARY LOOKS TO BE KNOCKING ON THE DOOR OF THE FAR NW CORNER OF THE CWA. DID RAISE POPS A BIT DURING THE EVENING/OVERNIGHT HOURS ACROSS THE N/NWRN PORTIONS OF THE CWA...BUT DIDNT MAKE MUCH CHANGE FURTHER SOUTH. AHEAD OF THE FRONT ON MONDAY...EXPECTING INCREASED SOUTHERLY WINDS...LIKELY A BIT GUSTY DURING THE AFTERNOON...AND WARMER TEMPERATURES WITH HIGHS FORECAST TO REACH INTO THE MID/UPPER 90S FOR MUCH/IF NOT ALL OF THE CWA. CONDITIONS DURING THE AFTERNOON HOURS SHOULD REMAIN BELOW CRITICAL FIRE LEVELS...RHS COULD DROP INTO THE LOWER/MID 20S ACROSS THE SOUTH...BUT SUSTAINED WIND SPEEDS ARE EXPECTED TO REMAIN <20 MPH...THOUGH GUSTS COULD AT TIMES COME CLOSE TO 25 MPH. WILL BE SOMETHING TO KEEP AN EYE ON IF MODELS HAPPEN TO TREND UP WINDS/TREND DOWN DPS. KEPT SOME LINGERING POPS IN DURING THE DAY ON TUESDAY...MAINLY ACROSS THE SRN HALF OF THE CWA...IN CLOSER PROXIMITY TO WHERE THE SFC BOUNDARY IS EXPECTED TO BE /SOMEWHERE NEAR OR SOUTH OF THE NEB AND KS STATE LINE/. CONFIDENCE NOT THE HIGHEST...AS THE PLACEMENT OF THE FRONT WILL BE DEPENDENT ON HOW THINGS PAN OUT MONDAY NIGHT. WITH MOST OF THE CWA LOOKING TO BE ON THE NORTH SIDE OF THAT BOUNDARY...MORE EASTERLY WINDS EXPECTED TO BE IN PLACE...AND FORECAST HIGHS ARE A TOUCH COOLER THAN MONDAY...MORE IN THE LOWER/MID 90S. BY 00Z WEDNESDAY...THE UPPER LEVEL PATTERN ACROSS THE CONUS HAS BECOME MORE AMPLIFIED...WITH MORE SOLIDLY NORTHWESTERLY FLOW IN PLACE ACROSS THE REGION AS THE RIDGE AXIS EXTENDS FROM THE DESERT SW THROUGH THE ROCKIES AND INTO CANADA. THE NOSE OF AN UPPER LEVEL JET STREAK ROUNDING THE TOP OF THE RIDGE AXIS IS EXPECTED TO SHIFT INTO THE REGION FROM THE NW...BRINGING THE POTENTIAL FOR MORE PRECIPITATION TUESDAY EVENING/OVERNIGHT. SIMILAR TO MONDAY/MONDAY NIGHT...WHILE THERE IS INSTABILITY IN PLACE ACROSS THE REGION...OVERALL DEEP LAYER SHEAR IS CERTAINLY NOT OUTSTANDING...GENERALLY TOPPING OUT IN THE 25-30 KTS RANGE...SO WHILE SOME THUNDERSTORMS COULD BE ON THE STRONGER SIDE...NOT EXPECTING SEVERE WEATHER AT THIS POINT. INTO WEDNESDAY...MODELS CONTINUE TO SHOW THE NOSE OF THIS UPPER LEVEL JET IN THE AREA...AND DECIDED TO KEEP SOME LINGERING POPS IN THE AREA...BUT CONFIDENCE IN CHANCES STICKING AROUND LONGER THAN PERHAPS A FEW HOURS IN THE MORNING NOT EXACTLY HIGH. THAT LOWER CONFIDENCE CONTINUES RIGHT ON THROUGH THE REMAINDER OF THE LONG TERM PERIOD. THE UPPER LEVEL PATTERN REMAINS NORTHWESTERLY ACROSS THE REGION WITH THE RIDGE STAYING IN PLACE OVER THE CENTRAL ROCKIES...AND KEPT THE FORECAST DRY AT THIS POINT...WITH MODELS SHOWING SOME DIFFERENCES WITH DISTURBANCES PASSING TO THE EAST OF THE CWA...AND WHETHER WE SEE ANY PRECIP AS RESULT. WITH THE RIDGE/WARMEST AIR REMAINING OFF TO THE WEST OF THE CWA...AND THE POTENTIAL FOR AN ADDITIONAL FRONTAL PASSAGE...NOTABLY HIGHER TEMPERATURES ARE NOT EXPECTED...WITH FORECAST HIGHS RANGING FROM ROUGHLY THE MID 90S WED/THUR TO THE MID 80S TO LOWER 90S FRI/SAT. && .PREV DISCUSSION... /ISSUED 1155 AM CDT SAT AUG 4 2012/ UPDATE...THE PRIMARY CHALLENGE FOR THE REST OF TODAY INVOLVES WHETHER THERE IS MUCH RISK AT ALL FOR MEASURABLE RAIN...AND JUST HOW COOL HIGH TEMPS MAY END UP BEING UNDER THE AREAS THAT HOLD ONTO CLOUDS THE LONGEST. 1630Z RADAR IMAGERY AND VISIBLE SATELLITE REVEAL A SCATTERED STREAM OF LIGHT SHOWERS/SPRINKLES LIKELY BASED AROUND 700MB STREAMING INTO SOUTHWEST PORTIONS OF THE CWA FROM THE WEST. THIS HIGH BASED ACTIVITY SEEMS FAIRLY WELL TIED TO A MODEST CORRIDOR OF CONVERGENCE/FRONTOGENESIS EVIDENT AT 700MB AND ALSO ON THE 315K ISENTROPIC SURFACE. THIS FORCING IS ALIGNED ALONG THE SOUTHERN PERIPHERY OF THE MAIN MID LEVEL SHORTWAVE AXIS TRAILING SOUTHWEST FROM THE PARENT STOUT VORT MAX NEAR THE MN/QUEBEC BORDER. EXPECTATION BASED ON SHORT TERM TRENDS FROM THE LATEST HRRR/RAP IS FOR MAINLY LIGHT HIGH BASED SHOWERS TO CONTINUE SPREADING FROM WEST TO EAST TROUGH AT LEAST 21Z OR SO ACROSS AREAS PRIMARILY SOUTH OF INTERSTATE 80...LIKELY AMOUNTING TO LITTLE MORE THAN A BRIEF SPRINKLE MOST SPOTS. HOWEVER...LEFT AN ISOLATED THUNDER AND EVEN A SMALL HAIL MENTION INTACT...JUST IN CASE A FEW STRONGER STORMS ARE ABLE TO FLARE UP AND TAP INTO ELEVATED MUCAPE POSSIBLY AS HIGH AS THE 500-1000 J/KG RANGE...BUT LIKELY LESS THAN THIS. THE MOST FAVORABLE AREA FOR ONE OF THESE STRONGER STORMS...SHOULD THEY EVEN DEVELOP...WOULD BE ACROSS A HANDFUL OF FAR SOUTHEASTERN COUNTIES. OTHERWISE...CURRENT EXPECTATION IS THAT ANY PRECIPITATION RISK FOR THE NEXT FEW DAYS WILL BE OVER WITH BY...OR SHORTLY AFTER 21Z THIS AFTERNOON. TEMP WISE TODAY...HAVE ESSENTIALLY LEFT PREVIOUS HIGH TEMPERATURES UNCHANGED. ANTICIPATE THAT AT LEAST CENTRAL/NORTHWEST PORTIONS OF THE CWA SHOULD SEE A RAPID CLEARING TREND AS THE AFTERNOON WEARS ON...LIKELY ALLOWING TEMPS TO EVENTUALLY JUMP UP TO FORECAST VALUES AROUND 83. HOWEVER...SOUTHEAST PORTIONS OF THE CWA THAT WILL LIKELY REMAIN UNDER THE CLOUDS THE LONGEST COULD STRUGGLE TO REACH THE FORECAST VALUES OF 82-84...AND AGREE WITH OVERNIGHT FORECASTER THAT SOME SPOTS MAY NOT ESCAPE THE UPPER 70S. WILL HAVE A BETTER HANDLE ON THIS BY AFTERNOON FORECAST ISSUANCE TIME. OTHERWISE...INTRUSION OF DRIER AIR BEHIND THE COLD FRONT HAS BEEN FAIRLY IMPRESSIVE WITH ORD DOWN TO 49 DEWPOINT NOW. AS A RESULT...LOWERED AFTERNOON DEWPOINTS 6-8 DEGREES ACROSS MUCH OF THE CWA...WITH COMFORTABLE 40S/LOW 50S DEWS LIKELY INTO MOST COUNTIES BY MID-LATE AFTERNOON. NORTH BREEZES WILL CONTINUE GUSTING AT LEAST 20-25 MPH THROUGH MID AFTERNOON...BEFORE STEADILY DECLINING BEFORE SUNSET. AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY ARE FORECAST THROUGH THE PERIOD. ESSENTIALLY CLEAR SKIES WILL DOMINATE THE AREA THROUGH THE MAJORITY OF THE PERIOD...BUT FOR AT LEAST THE INITIAL 3-5 HOURS QUITE A BIT OF MID LEVEL CLOUD COVER WILL STREAM OVER...ALONG WITH JUST A SLIGHT CHANCE OF BRIEF PASSING SHOWERS...WHICH HAVE BEEN SUGGESTED WITH A VICINITY SHOWER MENTION. SURFACE BREEZES WILL REMAIN NORTHERLY THROUGH TONIGHT IN THE WAKE OF A SEASONABLY STRONG COLD FRONT. THE STRONGEST SPEEDS WITH GUST POTENTIAL TO AROUND 20KT WILL OCCUR DURING THE FIRST FEW HOURS OF THE PERIOD...BEFORE A STEADY SLACKENING OF SPEEDS COMMENCES. FROM SUNSET THROUGH MID-DAY SUNDAY...SPEEDS SHOULD AVERAGE UNDER 6KT AND BECOME A BIT VARIABLE IN DIRECTION WITH TIME. && .CLIMATE...TODAY/TONIGHT WILL LIKELY END UP BEING THE COOLEST DAY/NIGHT AT GRAND ISLAND AND HASTINGS IN 6.5 WEEKS. BASED ON FORECAST PROJECTIONS OVER THE NEXT FEW HOURS...THE CALENDAR DAY HIGH TEMPERATURE AT BOTH GRAND ISLAND AND HASTINGS WILL END UP SOMEWHERE BETWEEN 78-82 DEGREES...BUT IS GUARANTEED TO BE AT LEAST 78 BECAUSE THIS VALUE WAS REACHED SHORTLY AFTER MIDNIGHT BEFORE THE COLD FRONT INVADED. FOR GRAND ISLAND...A HIGH OF 79-82 DEGREES WOULD RESULT IN THE COOLEST DAILY HIGH SINCE JUNE 20TH...WHEN IT TOPPED OUT AT 79. FOR HASTINGS...A HIGH OF 78-79 DEGREES WOULD ALSO RESULT IN THE COOLEST DAY SINCE JUNE 20TH...WHEN IT REACHED 78. TURNING TO LOW TEMPERATURES TONIGHT...THE CURRENT FORECAST FOR BOTH GRAND ISLAND AND HASTINGS CALLS FOR 55. THIS IS ONLY 3 DEGREES ABOVE HASTINGS AUGUST 5TH RECORD LOW OF 52...AND 4 DEGREES ABOVE THE GRAND ISLAND RECORD LOW OF 51...BOTH SET IN 1994. ASSUMING IT DIPS TO AT LEAST 57 DEGREES OVERNIGHT...THIS WILL BE THE COOLEST LOW TEMP IN BOTH CITIES SINCE JUNE 21ST...WHEN GRAND ISLAND BOTTOMED OUT AT 52 AND HASTINGS 51. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM/AVIATION...PFANNKUCH LONG TERM...ADO
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
115 PM EDT SAT AUG 4 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 1030 AM SATURDAY...DEEP TROPICAL SOUTHEASTERLY FLOW DEVELOPING ACROSS THE REGION TODAY WHILE MID LEVEL LOW OVER THE REGION BOTH LIFTS OUT TO THE NORTH AND WEAKENS. THIS LEAVES THE COASTAL CAROLINAS WITH LITTLE IN THE WAY OF FORCING FOR PRECIP OTHER THAN FRICTIONAL CONVERGENCE ALONG THE COAST. 12Z WRF SHOWING JUST A FEW TROPICAL SHOWERS MATERIALIZING OVER NC COASTAL ZONES. HRRR RUNS GO BACK AND FORTH BETWEEN SHOWING MINIMAL COVERAGE AND NO COVERAGE AT ALL. AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM. && .SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY. && .AVIATION /18Z SATURDAY THROUGH WEDNESDAY/... AS OF 18Z...TROPICAL ENVIRONMENT WITH SOUTHEAST FLOW THROUGH 500 MB. THIS REGIME WILL GIVE US SCATTERED CONVECTION ALONG THE RESULTANT THIS AFTERNOON. GIVEN THE UPPER FLOW...SEA BREEZE CONVECTION SHOULD GENERALLY REMAIN INLAND FROM THE COASTAL TERMINALS. MOST OF THE STUFF WILL BE FAIRLY LOW TOPPED...HOWEVER SCATTERED THUNDER IS EXPECTED. SOUTHEAST WINDS WILL CONTINUE INTO THE EVENING HOURS. SUNDAY...SYNOPTICALLY SIMILAR TO TODAY...WITH AFTERNOON THUNDER PERSISTING. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM SATURDAY...SEAS JUST 2.5 FT ALL THE WAY OUT AT BUOY 41013 WITH DOMINANT PERIOD 8-9 SECONDS INDICATIVE OF SWELL ENERGY. JUST A SUBLET CHANGE TO SEAS FORECAST FROM A STRAIGHT 3 FT TO THAT OF 2 TO 3 FT AS A THOUSAND MILE SOUTHEAST FETCH CONTINUES INTO THE CAROLINAS. AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT... WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE CLOSER PROXIMITY OF THE INVERTED SFC TROF. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE RULED OUT EARLY ACROSS THE OUTER WATERS. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...MBB SHORT TERM...SHK LONG TERM...SHK AVIATION...43
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
355 PM EDT SAT AUG 4 2012 .SYNOPSIS... MUGGY AUGUST AIR THROUGH WEEKEND. WITH A LOCAL DOWNPOUR POSSIBLE. MORE WIDESPREAD AND ORGANIZED CONVECTION LIKELY SUNDAY...WELL AHEAD OF COLD FRONT. DRIER AIR TRIES TO CREEP SOUTH MONDAY. && .NEAR TERM /THROUGH SUNDAY/... CONVECTION CURRENTLY DEVELOPING IN ASSOCIATION WITH WEAK VORT MAX SHOWING UP ON RAP MOVING INTO CWA FROM THE WEST. DOWNPOURS WILL BE POSSIBLE WITH THESE STORMS...AND ISOLATED FLASH FLOODING MAY OCCUR. NOT EXPECTING FLASH FLOOD THREAT TO BE WIDESPREAD ENOUGH TO WARRANT A SHORT FLASH FLOOD WATCH THOUGH THIS EVENING. TOMORROW IS ANOTHER STORY...MOISTURE CONTINUES TO INCREASE OVERNIGHT...WITH PWAT VALUES CLIMBING TO OVER 2.25 INCHES BY 18Z SUNDAY ON THE NAM AND GFS. EXPECT WIDESPREAD PRECIPITATION...WITH VERY HEAVY RAINFALL SUNDAY AFTERNOON INTO SUNDAY NIGHT...AND OPTED TO ISSUE A FLASH FLOOD WATCH FOR LINE ROUGHLY HTS TO CKB AND SOUTH. ONE THING TO WATCH WILL BE STORM SPEEDS...WITH 20-30KTS MID LEVEL FLOW...STORMS WILL BE PROGRESSIVE...BUT WITH FLASH FLOOD GUIDANCE BETWEEN 1.5 AND 2 INCHES ACROSS A LOT OF THE WATCH AREA...EVEN STORMS THAT ARE MOVING COULD EASILY REACH THIS THRESHOLD. PLUS...IF ANY TRAINING CELLS OCCUR THREAT WILL INCREASE GREATLY. AS FOR SEVERE THREAT...MODELS HAVE BEEN BACKING OFF ON INSTABILITY A BIT. THINK THIS IS A GOOD TREND...DUE TO MORE CLOUDS LEADING TO LESS HEATING. STILL...1500-2000 J/KG CAPE SHOULD BE ENOUGH TO TAP INTO GOOD MID-LEVEL FLOW AND PRODUCE STRONG TO SEVERE WIND GUSTS IN THE TALLER STORMS. BLENDED IN MET GUIDANCE FOR TEMPS OVERNIGHT...AS IT HAS BEEN PERFORMING QUITE WELL LATELY...WHICH RESULTED IN MINIMAL CHANGES. WITH MORE CLOUDS AROUND...BLENDED IN THE MAV FOR HIGHS TOMORROW LIKING ITS DEPICTION OF COOLER TEMPS IN SE OHIO WHERE PRECIP WILL REACH FIRST. THIS RESULTED OVERALL IN A BIT COOLER DAY THAN PREVIOUS FORECAST. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... WE ARE HOPING THE PREFRONTAL CONVECTION DOES NOT ORIENT MORE EAST TO WEST...BUT THE FLASH FLOOD WATCH WAS POSTED EARLY...FOR THAT POSSIBILITY. AS WE HEAD INTO SUNDAY EVENING...OUR SOUTHERN COUNTIES SEEM TO BE MORE VULNERABLE TO SOME TRAINING...DESPITE THE 25 TO 30 KNOT CELL MOVEMENT THAT WE ARE EXPECTED. WILL BASE FORECAST ON SURFACE FRONT FROM NEAR EKN TO CRW TO SOUTH OF HTS AT 12Z MONDAY. SO HAD TO LEAVE SOME CHANCE POPS ALONG THAT FEATURE. PICTURING LOW CLOUDS ALONG THAT FRONT TOO. PROBABLY MOSTLY JUST LINGERING RAIN SHOWERS RATHER THAN THUNDER. PROBLEM THEN BECOMES...HOW LONG TO LINGER SOME 20/30 POPS IN OUR EXTREME SOUTH INTO TUESDAY. WE ARE TYPICALLY LEARY OF THE DRIER AIR IN THE LOW LEVELS MAKING IT THROUGH THE SOUTHERN MOUNTAINS. SO EVEN THOUGH THE MID LEVELS SHOULD DRY OUT...WILL NOW HOLD ONTO SOME 20/30 POPS IN SW VIRGINIA TO NEAR BECKLEY FOR TUESDAY. THERE COULD BE WIDESPREAD FOG MONDAY NIGHT FROM EKN TO CRW INTO THE COAL FIELDS. YET...BEING THE THIRD NIGHT INTO THE FUTURE...WILL HOLD OFF INCLUDING THOSE SPECIFICS FOR NOW. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... 12Z GFS AND 12Z ECMWF SOLUTIONS CONTINUE TO AGREE THAT THE MID LEVEL RIDGE...BAKING THE PLAINS THIS SUMMER...WILL SLIDE BACK WEST INTO THE GREAT BASIN...WITH A STRONG TROF SWINGING THROUGH OUR VICINITY ON DAY 7...WITH THE SURFACE FRONT LIKELY AHEAD OF IT...ON DAY 6/FRIDAY. PROBLEM FOR WEDNESDAY AND THURSDAY IS THE DEEP MOISTURE LINGERING TO OUR SOUTHEAST. WILL TRY TO HOLD WEDNESDAY DRY MAINLY FOR COUNTIES NORTH OF A HTS-CRW-EKN LINE...WITH SOME 20/30 POPS ALONG OUR SOUTHEASTERN COUNTIES WEDNESDAY. WENT ALONG WITH HPC MEDIUM RANGE CHANCE POPS FOR THURSDAY AND FRIDAY...WITH A COOL DOWN FOR SATURDAY. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... CONVECTION JUST BEGINNING TO FORM ACROSS THE EASTERN MOUNTAINS...AND ALSO IN EASTERN KY. EXPECT ADDITIONAL DEVELOPMENT THROUGH THE AFTERNOON...WITH SCATTERED SHOWERS AND THUNDERSTORMS LINGERING INTO THE EVENING. KEPT EVERYTHING VFR FOR TODAY...HOWEVER BRIEF MVFR IS POSSIBLE IN THE STRONGER CELLS. WITH MORE CLOUDS AND SOME WIND REMAINING OVERNIGHT...DO NOT EXPECT DENSE FOG TO FORM. WILL INCLUDED MVFR FOG TONIGHT IN MOST SHELTERED MOUNTAIN VALLEYS LIKE KEKN. TOWARDS THE END OF THE TAF PERIOD...EXPECT SHOWERS AND THUNDERSTORMS...WITH HEAVY RAIN POSSIBLE...TO BE ON THE INCREASE FROM WEST TO EAST AS COLD FRONT APPROACHES. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY... FORECAST CONFIDENCE: MEDIUM TO HIGH. ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS TODAY MAY VARY...WITH AMENDMENTS POSSIBLE. ADDITIONAL POCKETS OF FOG MAY FORM OVERNIGHT IF CLOUD BREAKS DEVELOP. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H M M H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z SUNDAY... BRIEF IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS INTO SUNDAY NIGHT. IFR IN LOW STRATUS POSSIBLE NEAR SURFACE FRONT MONDAY MORNING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR WVZ005-006-013>020-024>040-046-047. OH...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR OHZ087. KY...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR KYZ101>103-105. VA...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR VAZ003-004. && $$ SYNOPSIS...KTB/MZ NEAR TERM...MZ SHORT TERM...KTB/ARJ LONG TERM...KTB AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
225 PM EDT SAT AUG 4 2012 .SYNOPSIS... WARM AND HUMID...WITH SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON. A COLD FRONT BRINGS WIDESPREAD AND STRONGER STORMS...WITH HEAVY RAIN AND SEVERE WEATHER SUNDAY AND SUNDAY NIGHT. && .NEAR TERM /THROUGH SUNDAY/... CONVECTION CURRENTLY DEVELOPING IN ASSOCIATION WITH WEAK VORT MAX SHOWING UP ON RAP MOVING INTO CWA FROM THE WEST. DOWNPOURS WILL BE POSSIBLE WITH THESE STORMS...AND ISOLATED FLASH FLOODING MAY OCCUR. NOT EXPECTING FLASH FLOOD THREAT TO BE WIDESPREAD ENOUGH TO WARRANT A SHORT FLASH FLOOD WATCH THOUGH THIS EVENING. TOMORROW IS ANOTHER STORY...MOISTURE CONTINUES TO INCREASE OVERNIGHT...WITH PWAT VALUES CLIMBING TO OVER 2.25 INCHES BY 18Z SUNDAY ON THE NAM AND GFS. EXPECT WIDESPREAD PRECIPITATION...WITH VERY HEAVY RAINFALL SUNDAY AFTERNOON INTO SUNDAY NIGHT...AND OPTED TO ISSUE A FLASH FLOOD WATCH FOR LINE ROUGHLY HTS TO CKB AND SOUTH. ONE THING TO WATCH WILL BE STORM SPEEDS...WITH 20-30KTS MID LEVEL FLOW...STORMS WILL BE PROGRESSIVE...BUT WITH FLASH FLOOD GUIDANCE BETWEEN 1.5 AND 2 INCHES ACROSS A LOT OF THE WATCH AREA...EVEN STORMS THAT ARE MOVING COULD EASILY REACH THIS THRESHOLD. PLUS...IF ANY TRAINING CELLS OCCUR THREAT WILL INCREASE GREATLY. AS FOR SEVERE THREAT...MODELS HAVE BEEN BACKING OFF ON INSTABILITY A BIT. THINK THIS IS A GOOD TREND...DUE TO MORE CLOUDS LEADING TO LESS HEATING. STILL...1500-2000 J/KG CAPE SHOULD BE ENOUGH TO TAP INTO GOOD MID-LEVEL FLOW AND PRODUCE STRONG TO SEVERE WIND GUSTS IN THE TALLER STORMS. BLENDED IN MET GUIDANCE FOR TEMPS OVERNIGHT...AS IT HAS BEEN PERFORMING QUITE WELL LATELY...WHICH RESULTED IN MINIMAL CHANGES. WITH MORE CLOUDS AROUND...BLENDED IN THE MAV FOR HIGHS TOMORROW LIKING ITS DEPICTION OF COOLER TEMPS IN SE OHIO WHERE PRECIP WILL REACH FIRST. THIS RESULTED OVERALL IN A BIT COOLER DAY THAN PREVIOUS FORECAST. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... A COLD FRONT APPROACHES TO SOUTHEAST OH SUNDAY. MODELS ARE IN GOOD AGREEMENT TIGHTENING THE PRESSURE GRADIENT AND FLOW AT H850 FROM THE SOUTHWEST...AND BRINGING MOISTURE ADVECTION TO THE AREA EARLY SUNDAY MORNING. THETA-E VALUES REACHING 340K SUGGEST VERY JUICY AIR CAPABLE TO PRODUCE HEAVY RAIN AND STRONG STORMS WILL SPREAD EAST ACROSS WV DURING THE PEAK OF DIURNAL HEATING. THIS MOISTURE IS ALSO NOTED IN PRECIPITABLE WATER VALUES EXCEEDING 2.2 INCHES. ALTHOUGH EQUILIBRIUM LEVEL EXCEEDING 40 KFT...A THIN CAPE SOUNDING AND LOW UNIDIRECTIONAL DEEP LAYERED SHEAR VALUES SUGGEST WATER LOADING EFFECTS WITH TALL STORMS. THESE CONDITIONS COULD REDUCE SEVERE UPDRAFTS...BUT WILL PROMOTE VERY HEAVY DOWNPOURS. STRONG H5 VORTICITY MAXIMUM REACHES SOUTHEAST OH BY MON 00Z...SUGGESTING GOOD DYNAMICS COULD ENHANCE STORMS DURING THE AFTERNOON HOURS. THEREFORE...EXPECT CONVECTION FIRING UP AHEAD OF THE FRONT BY MID DAY SUNDAY...AND SPREAD EAST NORTHEAST...WITH CONTINUING CONVECTION DEVELOPING ACROSS SOUTHEAST OH WITH THE STRONGER UPPER FORCING APPROACHING THROUGH THE EVENING. ALTHOUGH THERE IS A SLIGHT RISK FOR SEVERE STORMS ACROSS THE ENTIRE AREA...WILL ALSO WATCH FOR WATER PROBLEMS WITH THE AFOREMENTIONED SCENARIO. KEPT CAP POPS SUNDAY AFTERNOON ACROSS SOUTHEAST OH...SPREADING EAST THROUGH SUNDAY NIGHT. THE FRONT SEEMS TO SLOW DOWN AS IT ENTERS WV...AND LINGER ACROSS THE SOUTHERN COAL FIELDS AND CENTRAL MOUNTAINS THROUGH TUESDAY MORNING. A FLASH FLOOD WATCH MAY BE REQUIRED FOR SUNDAY. KEPT HIGH TEMPS IN THE 80S SUNDAY AND MONDAY PER ABUNDANT CLOUDS AND RAINFALL EXPECTED. KEPT LOWS IN THE LOWER 70S SUNDAY NIGHT PER ABUNDANT MOISTURE AND LACK OF EXTRA PUSH OF DRIER AIR TO DISPLACE HIGH DEWPOINTS...BUT IN THE MID 60S MONDAY NIGHT PER CLEARING SPREADING FROM THE WEST AND ASSOCIATED RADIATIONAL COOLING. AREAS OF DENSE FOG WILL BE POSSIBLE UNDER CLEAR SKIES AND AREAS THAT RECEIVE RAINFALL TUESDAY MORNING. && .LONG TERM /TUESDAY THROUGH SATURDAY/... GOING WITH HPC. NORTHWEST FLOW ALOFT STRENGTHENS...WITH THE HOT AND HUMID AIR BEING SHUNTED TO THE SOUTH. TRANQUIL PERIOD OF DRY AND NEAR SEASONABLE TEMPERATURES DOMINATE THIS PERIOD AS WEAK HIGH PRESSURE DOMINATES. GOOD MODEL AGREEMENT ON THIS SCENARIO. BY FRIDAY...NEXT SYSTEM APPROACHES AS THE UPPER FLOW BECOMES MORE WESTERLY AND ALLOWS THE HEAT AND MOISTURE TO RETURN. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... CONVECTION JUST BEGINNING TO FORM ACROSS THE EASTERN MOUNTAINS...AND ALSO IN EASTERN KY. EXPECT ADDITIONAL DEVELOPMENT THROUGH THE AFTERNOON...WITH SCATTERED SHOWERS AND THUNDERSTORMS LINGERING INTO THE EVENING. KEPT EVERYTHING VFR FOR TODAY...HOWEVER BRIEF MVFR IS POSSIBLE IN THE STRONGER CELLS. WITH MORE CLOUDS AND SOME WIND REMAINING OVERNIGHT...DO NOT EXPECT DENSE FOG TO FORM. WILL INCLUDED MVFR FOG TONIGHT IN MOST SHELTERED MOUNTAIN VALLEYS LIKE KEKN. TOWARDS THE END OF THE TAF PERIOD...EXPECT SHOWERS AND THUNDERSTORMS...WITH HEAVY RAIN POSSIBLE...TO BE ON THE INCREASE FROM WEST TO EAST AS COLD FRONT APPROACHES. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY... FORECAST CONFIDENCE: MEDIUM TO HIGH. ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS TODAY MAY VARY...WITH AMENDMENTS POSSIBLE. ADDITIONAL POCKETS OF FOG MAY FORM OVERNIGHT IF CLOUD BREAKS DEVELOP. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY M M H H H M M H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z SUNDAY... BRIEF IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS INTO SUNDAY NIGHT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR WVZ005-006-013>020-024>040-046-047. OH...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR OHZ087. KY...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR KYZ101>103-105. VA...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR VAZ003-004. && $$ SYNOPSIS...ARJ/MZ NEAR TERM...MZ SHORT TERM...ARJ LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
420 PM EDT SAT AUG 4 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND THE CHANCE OF SHOWERS AND STORMS...SOME OF WHICH MAY BE STRONG TO SEVERE ON SUNDAY...BEFORE DRIER AIR BUILDS IN FOR EARLY NEXT WEEK. OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO 8 DAYS. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... SHOWERS AND STORMS WILL CONTINUE TO POP UP INTO THE EVENING IN THE MOIST SOUTHWESTERLY FLOW. MESO ANAL SHOWS CAPES TOPPING 4000J WITH INHIBITION DIMINISHING RAPIDLY. HAVE TRIED TO FASHION THE NEAR TERM POPS TO CURRENT RADAR TRENDS AND HRRR OUTPUT OVER THE NEXT SEVERAL HOURS. THESE KEEP SHOWERS AND STORMS INTO THE EVENING BEFORE QUIETING DOWN AFTER 03Z. AIRMASS IS VERY SOUPY WITH PWATS OVER 1.5" FOR MUCH OF THE FCST AREA. CAN EASILY SEE 1-2 INCH PER HOUR RAINFALL RATES IN SOME OF THE MORE ROBUST STORMS...ALONG WITH LOCALLY GUSTY POSSIBLY EVEN DAMAGING WINDS. ACTIVITY SHOULD DIMINISH TOWARD MIDNIGHT WITH PATCHY FOG AHEAD OF THE FRONT IS AGAIN A POSSIBILITY LATER AT NIGHT. IT WILL BE QUITE MUGGY WITH LOWS A FEW DEG EITHER SIDE OF 70 EVERYWHERE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG FOR EARLY AUG. CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE. BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY FROM MID AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE THUNDERSTORMS...FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME. MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG STORMS FROM ABOUT 2 PM SUNDAY UNTIL 10 PM IN EAST. && .LONG TERM /MONDAY THROUGH SATURDAY/... BY MONDAY MORNING...COLD FRONT WILL BE JUST SE OF CWA. WILL TAKE SOME TIME TO CLEAR OUT RESIDUAL MOISTURE IN SOUTHEAST. BUT WITH WESTERLY WINDS...DRIER AIR WILL EVENTUALLY WORK INTO THE BOUNDARY LAYER IN THE SE. PW FALLS BELOW NORMAL STATE WIDE MONDAY. CENTER OF SFC HIGH SETTLES OVER PA MON NIGHT/TUE KEEPING FORECAST DRY. WEAK WAVE OVER SE U.S. SLIDES UP THE COAST FOR WED/THU...NUDGING MOISTURE BACK INTO CWA. SO INTRODUCED SLIGHT CHANCE FOR A TSTM WED/THU AS HUMIDITY BEGINS TO INCREASE. MORE POTENT TROUGH APPROACHES IN NW FLOW FOR THU NIGHT-FRI NIGHT. MODELS HANDLING THIS FEATURE WELL...THOUGH GFS TRIES TO LIFT TROUGH NORTHWARD. EITHER WAY...CHANCE OF SHOWERS/TSTMS FITS THE BILL BEFORE A MAINLY DRY WEEKEND. TEMPERATURES WILL BE NEAR NORMAL TO START THE WEEK...THEN SLOWLY RISE BACK ABOVE NORMAL FOR MIDWEEK. AS HUMIDITY INCREASES LATE WEEK AHEAD OF APPROACHING TROUGH...TEMPS AGAIN GET A BIT MUGGY - EVEN THOUGH THEY REMAIN JUST A FEW DEGREES ABOVE NORMAL. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED INTO THE EVENING AS SHOWERS AND THUNDERSTORMS CONTINUE TO POP UP UNDER DAYTIME HEATING. STORM OVER MDT HAS CAUSED LIFR IN THE HEAVY RAIN...AND OTHER TERMINALS CAN EXPECT SIMILAR CONDITIONS WHERE DIRECT HITS FROM STORMS TAKE PLACE. OUTLOOK... .SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY SUNDAY PM AS A COLD FRONT MOVES THROUGH. .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES-THU...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...RXR LONG TERM...RXR AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
159 PM EDT SAT AUG 4 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR BUILDS IN FOR EARLY NEXT WEEK. OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO 8 DAYS. && .NEAR TERM /THROUGH TONIGHT/... SHOWERS AND STORMS WILL CONTINUE TO POP UP INTO THE EVENING IN THE MOIST SOUTHWESTERLY FLOW. MESO ANAL SHOWS CAPES TOPPING 4000J WITH INHIBITION DIMINISHING RAPIDLY. HAVE TRIED TO FASHION THE NEAR TERM POPS TO CURRENT RADAR TRENDS AND HRRR OUTPUT OVER THE NEXT SEVERAL HOURS. THESE KEEP SHOWERS AND STORMS INTO THE EVENING BEFORE QUIETING DOWN AFTER 03Z. AIRMASS IS VERY SOUPY WITH PWATS OVER 1.5" FOR MUCH OF THE FCST AREA. CAN EASILY SEE 1-2 INCH PER HOUR RAINFALL RATES IN SOME OF THE MORE ROBUST STORMS...ALONG WITH LOCALLY GUSTY POSSIBLY EVEN DAMAGING WINDS. ACTIVITY SHOULD DIMINISH TOWARD MIDNIGHT WITH PATCHY FOG AHEAD OF THE FRONT IS AGAIN A POSSIBILITY LATER AT NIGHT. IT WILL BE QUITE MUGGY WITH LOWS A FEW DEG EITHER SIDE OF 70 EVERYWHERE. && .SHORT TERM /SUNDAY/... SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG FOR EARLY AUG. CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE. BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME. MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION. PROBABLY NEED 90S IN THERE! && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID- MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW FALLS BELOW NORMAL STATE WIDE MONDAY. KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL. PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO GUIDANCE. TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A BIT MORE THURSDAY INTO FRIDAY. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED INTO THE EVENING AS SHOWERS AND THUNDERSTORMS CONTINUE TO POP UP UNDER DAYTIME HEATING. STORM OVER MDT HAS CAUSED LIFR IN THE HEAVY RAIN...AND OTHER TERMINALS CAN EXPECT SIMILAR CONDITIONS WHERE DIRECT HITS FROM STORMS TAKE PLACE. OUTLOOK... .SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY SUNDAY PM AS A COLD FRONT MOVES THROUGH. .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES-THU...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LAMBERT/MARTIN LONG TERM...GRUMM/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
412 PM EDT SAT AUG 4 2012 .SYNOPSIS... A WEAK COLD FRONT WILL APPROACH THE APPALACHIANS LATE ON SUNDAY AND SLOWLY MOVE THROUGH THE REGION ON MONDAY. THIS FRONT WILL PROVIDE THE TRIGGER FOR MORE WIDESPREAD SHOWERS AND THUNDERSTORMS... SOME WITH VERY HEAVY RAINFALL. THE FRONT WILL DRIFT INTO THE CAROLINAS BY TUESDAY AND DISSIPATE...BUT LINGERING MOISTURE BEHIND IT WILL ALLOW SOME SCATTERED SHOWERS AND THUNDERSTORMS TO CONTINUE THROUGH MUCH OF NEXT WEEK. && .NEAR TERM /TONIGHT THROUGH SUNDAY/... AS 0F 205 PM EDT SATURDAY... SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPED IN THE MOIST AND UNSTABLE AIR ACROSS OUR REGION THIS AFTERNOON. VORT LOBE WILL MOVE ACROSS THE APPALACHIANS ENHANCING SHOWERS AND THUNDERSTORMS. THE WRFARW-RNK...HRRR...NAM...RUC AND GFS KEEP SCATTERED STORMS THIS EVENING INTO TONIGHT. ANY SLOW MOVING THUNDERSTORM MAY PRODUCE HEAVY RAIN. FLASH FLOOD GUIDANCE IS RUNNING ABOUT 2 INCHES AN HOUR IN THE MTNS AND 3 INCHES AN HOUR IN THE PIEDMONT. LOCAL FLOODING PROBLEMS MAY BE A PROBLEM WITH TRAINING OF THUNDERSTORMS. WITH THE LOW LEVEL FLOW FROM THE SOUTH...EXPECT THE GREATEST CONVERGENCE ALONG THE BLUE RIDGE MOUNTAINS . SECONDARY AREA OF LOW LEVEL CONVERGENCE LIKELY TO DEVELOP THIS AFTERNOON INTO THIS EVENING OVER THE PIEDMONT. BOTH THE RUC AND NAM SHOWED SOME DEVELOPMENT OVER THE EAST THIS EVENING. LEANED TOWARDS THE NAM FOR TONIGHT POPS WITH ACTIVITY LINGER WELL INTO THE OVERNIGHT AIDED BY CONTINUED MOIST LOW LEVEL MOISTURE TRANSPORT INTO THE AREA UNDERNEATH NEARLY STATIONARY DISTURBANCE ALOFT. WENT WITH LOWS CLOSE TO THE ADJMETBC WITH READINGS FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 70S IN THE SOUTHEAST UNDER A BLANKET OF CLOUDS AND ELEVATED DEWPOINTS. UNSETTLED WEATHER WILL CONTINUE ON SUNDAY AHEAD OF APPROACHING FRONTAL BOUNDARY COMING OUT OF OHIO VALLEY. SOME INCREASE IN SHEAR AND SLIGHTLY STEEPER LAPSE RATES SUGGEST A BETTER SEVERE POTENTIAL AS WELL...WITH MORE ORGANIZED CLUSTERS COMING OUT OF OF WV AHEAD OF FRONT. WITH PWATS INCREASES THERE IS THE POTENTIAL FOR HEAVY RAINS. MAIN THREAT DURING THE DAY WOULD MAINLY BE IN THE WEST. PLAYED HIGH TEMPERATURES NEAR COOLER GUIDANCE WITH HIGHS FROM THE UPPER 70S IN THE MOUNTAINS TO AROUND 90 IN THE SOUTHEAST. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... AS OF 345 PM EDT SATURDAY... COLD FRONT NOT TO ARRIVE UNTIL SUNDAY NIGHT...AND IT MAY BE THAT BEST CHANCE FOR ORGANIZED CONVECTION...INCLUDING SLIGHT CHC OF SEVERE AND HEAVIEST RAINFALL RATES...DO NOT ARRIVE UNTIL THE EVENING. WITH SLOWER TIMING THE SEVERE POTENTIAL MAY BE LIMITED TO EXTREME WESTERN PORTIONS OF AREA IF IT COMES IN LATE ENOUGH IN EVENING...BUT HEAVY RAIN IS LOOKING LIKE A BIGGER CONCERN NOW UP UNTIL AT LEAST MIDNIGHT. CONTEMPLATED FLASH FLOOD WATCH FOR THIS PERIOD BUT WOULD NOT BE FOR MORE THAN ABOUT 6 HRS AS ANY HIGH RAINFALL RATES DISSIPATE THROUGHOUT THE EVENING...AND PROBABLY LIMITED TO FAR WESTERN PORTIONS...WV COUNTIES AND TAZEWELL MAINLY. SOME OF THESE LOCATIONS HAVE HAD SIGNIFICANT RAINFALL RECENTLY BUT IT`S BEEN HIT AND MISS. SO FOR NOW DECIDED TO HOLD OFF TO SEE IF FURTHER GUIDANCE SUGGESTS EITHER AN EARLIER START OR LONGER THREAT TIME INTO THE OVERNIGHT. INCREASES POPS SUNDAY NIGHT TO LIKELY AND CATEGORICAL IN WEST. MILDER OVERNIGHT LOWS MONDAY MORNING WITH EXTENSIVE CLOUD COVER AND LINGERING PRECIP...AND ALSO COOLER HIGHS MONDAY UNDER SIMILAR CONDITIONS AS FRONT SLOWLY MOVES ACROSS AREA. WENT SLIGHTLY COOLER THAN LOWEST GUIDANCE NUMBERS. NOT SURE HOW MUCH INSTABILITY WILL BE REALIZED FOR CONVECTION...SO MAINLY SHOWERS WITH ONLY SLIGHT CHC FIRST HALF OF DAY...AND WITH LIKELY POPS ACROSS THE SOUTH BY LATE IN THE DAY...STILL DOWNPLAYED THUNDER WITH ONLY A CHANCE. BETTER TSTORM COVERAGE MAY BE WELL SOUTH OF OUR AREA. BY TUESDAY SOME DIFFERENCES BETWEEN NAM AND GFS ARE EVIDENT...WITH NAM TAKEING FRONTAL BOUNDARY FARTHER SOUTH...AND GFS WASHING IT OUT ALLOWING BETTER SOUTHERLY FLOW TO RETURN. NAM HAS MID LEVEL DRY AIR AND SUBSIDENCE ACROSS THE NORTHERN HALF OF FCST AREA...SUPRESSING MOST CONVECTIVE THREATS DESPITE MODEST INSTABILITY...WHEREAS GFS REMAINS MOIST AND HINTS AT WEAK UPPER WAVE RIDING FROM SW TO NE HELPING TO SPREAD PRECIP BACK TO THE NORTH AGAIN. COMPROMISED BETWEEN THE TWO BUT WITH A LEAN TOWARD GFS...WITH SLIGHT CHC POPS ACROSS FAR NORTH BUT LIKELY ACROSS THE SOUTH. INCREASED CLOUD COVER AND LOWERED HIGHS A BUT AS WELL GIVEN FAVORED GFS SOLUTION...AGAIN GOING SLIGHTLY COOLER THAN LOWEST GUIDANCE. THIS HAS SOME BUST POTENTIAL IF NAM IS CORRECT AND PRECIP STAYS WELL SOUTH AND SOME CLEARING TAKES PLACE FARTHER NORTH. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 1245 PM EDT SATURDAY... DURING THE MID TO LATE PORTION OF THE WEEK...THE FRONTAL BOUNDARY IS EXPECTED TO STALL ALONG THE SOUTHERN PERIPHERY OF THE FORECAST AREA...IN RESPONSE TO A SLOWLY DIGGING UPPER LEVEL TROUGH OVER THE SOUTHERN GREAT LAKES REGION. THE CONSENSUS OF GUIDANCE IS NOT INDICATING THIS BOUNDARY WILL REMAIN CLOSE ENOUGH TO THE REGION TO CONTINUE TO PROVIDE A FOCUSING MECHANISM FOR DAILY CONVECTION...AIDED BY SOME WEAK UPPER LEVEL WAVES MOVING FROM SOUTHWEST TO NORTHEAST. GENERALLY DURING THE WED/THURS TIME FRAME THE PRECIP CHANCES WILL BE A LITTLE GREATER ACROSS THE SOUTHEAST CLOSER TO THE WEAKENING FRONTAL BOUNDARY...BUT AM CONTINUING WITH LOW TO MID CHANCE POPS FOR ALL LOCATIONS...EXCEPT FOR DIURNAL DROP TO SLIGHT CHC OVERNIGHT. THEN...AS THE UPPER TROUGH DEEPENS TOWARD THE END OF THE WEEK...A SECOND WEAK FRONTAL BOUNDARY WILL APPROACH FROM THE NORTH LATE FRIDAY OR EARLY SATURDAY...INCREASING THE CHANCES AGAIN FROM THE WEST. SOME MODELS ARE DEEPER WITH THIS TROUGH THAN OTHERS...AND SUGGEST A BETTER POSSIBILITY THAT THE FRONT WILL PUSH FARTHER THROUGH THE REGION BY LATE NEXT SATURDAY WITH POTENTIAL FOR SOME DRYING AND SLIGHTLY COOLER TEMPS. ONLY HEDGING SLIGHTLY TOWARD THIS IDEA SINCE THE CONSENSUS IN ENSEMBLES IS FOR A WEAKER TROUGH AND LIFTING NORTHEAST BY NEXT WEEKEND...SO STILL SOME UNCERTAINTY AS TO WHETHER THIS FRONT WILL REALLY PUSH THROUGH ANY FARTHER THAN THE ONE FOR EARLIER IN THE WEEK. WITH FRONTAL BOUNDARY LINGERING THROUGH MID WEEK JUST TO OUR SOUTH...LOOKS LIKE INSTABILITY MAY BE LIMITED WITH PLENTY OF CLOUD COVER EXPECTED...SO SEVERE POTENTIAL NOT ESPECIALLY HIGH...BUT RELATIVELY HIGH MOISTURE CONTENT WITH WEAK CONVERGENCE ALONG OLD BOUNDARY SUGGESTS A BIT MORE OF A FLASH FLOOD POTENTIAL ALTHOUGH THIS STILL MUCH DEPENDENT ON GETTING HIGHER RAINFALL RATES. INCREASED THE CLOUD COVER AND LOWERED HIGH TEMPS SOMEWHAT FROM PREVIOUS FORECAST FOR WED AND THURS...BUT STILL GOING CLOSE TO GFS-BASED GUIDANCE. SLIGHT WARMING BY FRIDAY AHEAD OF NEXT FRONTAL BOUNDARY BUT STILL BORDERLINE IF THERE WILL BE ANY 90S ACROSS THE PIEDMONT. TROPICAL ACTIVITY TO MONITOR WITH ERNESTO MOVING TOWARD YUCATAN AND INTO GULF BY MID WEEK BUT CURRENTLY EXPECTED TO REMAIN WELL SOUTH AND NOT INFLUENCE THE MID ATLANTIC REGION. A TROPICAL WAVE CURRENTLY OVER FLORIDA MAY EVENTUALLY EJECT SOME MOISTURE INTO OLD FRONTAL BOUNDARY TO OUR SOUTH...AND COULD HELP ENHANCE SOME OF THE PRECIP POTENTIAL BY MID WEEK. TROPICAL STORM FLORENCE WELL OUT IN THE ATLANTIC LIKELY TO REMAIN WELL AWAY FROM MAINLAND BEFORE WEAKENING. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... AS OF 1215 PM EDT SATURDAY... LOW CLOUDS AND CONVECTION WILL HINDER AVIATION OPERATIONS THIS AFTERNOON INTO TONIGHT. ATMOSPHERE REMAINS VERY MOIST...WITH UPPER VORT REMAINING ALONG THE APPALACHIANS THIS AFTERNOON. SCATTERED MVFR SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON INTO TONIGHT...KEPT VCTS AT TAF SITES UNTIL SUNSET. BELIEVE THAT BCB AND DAN TAF SITES HAS THE BEST CHANCE OF A THUNDERSTORM. DAN IS LOCATED BY THE RICHEST MOISTURE COMBINED WITH BEST INSTABILITY CREATED BY SOLAR HEATING. ANY THUNDERSTORMS THIS AFTERNOON WILL BE SLOW MOVING AND COULD CONTAIN HEAVY DOWNPOURS. EXPECT AREAS OF FOG TO DEVELOP OVERNIGHT ESPECIALLY WHERE THUNDERSTORMS OCCUR THIS AFTERNOON INTO THIS EVENING. DEEPER MOISTURE REMAINS INTO EARLY NEXT WEEK WITH GREATER COVERAGE OF SHOWERS AND STORMS...ESPCLY DURING THE AFTERNOON AND EVENING EACH DAY THROUGH MONDAY. LOCAL MVFR/IFR CONDITIONS WILL BE ASSOCIATED WITH THE MORE ORGANIZED STORMS. OUTSIDE OF THIS MAINLY DIURNALLY DRIVEN CONVECTION...THE ONLY OTHER FLIGHT WEATHER HAZARDS WOULD BE FROM OVERNIGHT VALLEY FOG. A COLD FRONT IS EXPECTED TO DROP SOUTHEAST OUT OF THE OHIO VALLEY MONDAY...CROSSING THE MID ATLANTIC REGION. WITH THE PASSAGE OF THIS FRONT...WINDS SHOULD BECOME NORTHERLY...WITH A DAY OR TWO OF DRY WEATHER AND VFR CONDITIONS FOLLOWING THE FRONTAL PASSAGE FOR MID WEEK. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...SK NEAR TERM...KK SHORT TERM...SK LONG TERM...SK AVIATION...KK/PM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
258 PM CDT SAT AUG 4 2012 .SHORT TERM...TODAY THROUGH SUNDAY. STORMS FIRED ALONG BOUNDARY IN MANITOWOC AND WAUPACA COUNTIES THIS AFTN...AS THE MORNING RUNS OF THE HRRR MODEL INDICATED. CORRIDOR OF HIGH INSTABILITY FROM S WI INTO THE FAR E PART OF THE STATE AND CONVERGENCE ALONG BOUNDARIES ENOUGH TO INITIATE DEEP CONVECTION. MAIN LINE OF SHOWERS AND STORMS...HOWEVER...MOVING INTO THE WEST PART OF FORECAST AREA. THIS WILL MOVE ACROSS THE AREA LATE THIS AFTERNOON AND EARLY EVENING PER LATEST RUN OF HRRR. BEST CHANCE OF SEVERE WILL BE SOUTH OF FORECAST AREA...BUT STILL A THREAT IN THE EAST-CENTRAL IN UNSTABLE AIRMASS AND INTERACTION OF LOW-LEVEL BOUNDARIES. UPPER TROF WILL QUICKLY SWING THROUGH TONIGHT. SMALL CHANCE FOR LINGERING SHOWERS BEHIND MAIN LINE LATER THIS EVENING. OTHERWISE...CLEARING SKIES ACROSS MUCH OF AREA. EXCEPTION IS IN THE FAR NORTH CLOSER TO THE UPPER LOW AND RESIDUAL MOISTURE. TEMPS TONIGHT AND SUNDAY ARE A BLEND OF MODELS...CLOSE TO PREVIOUS FORECAST. .LONG TERM...SUNDAY NIGHT THROUGH NEXT FRIDAY. MEAN LONGWAVE PATTERN FOR THE EXTENDED FORECAST PERIOD GENERALLY CHARACTERIZED BY A TROUGH OVER THE OHIO VALLEY AND RIDGE OVER THE INTERMOUNTAIN WEST. WESTERN GREAT LAKES REGION WILL RESIDE IN NORTHWESTERLY FLOW REGIME WITH AN OCCASIONAL EMBEDDED SHORTWAVE DISTURBANCES TRAVERSING THE AREA. TIMING AND INTENSITY OF EMBEDDED SHORTWAVE DISTURBANCES WITHIN THIS FLOW REGIME ARE TYPICALLY PROBLEMATIC...THUS FORECAST CONFIDENCE IN THIS REGARD IS LOW TO MEDIUM. EARLY IN THE WORK WEEK... DAYTIME TEMPERATURES WILL START OUT ABOVE NORMAL...THEN SLOWLY FALL BACK TO NEAR...OR PERHAPS SLIGHTLY BELOW NORMAL FOR EARLY AUGUST. SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD EASTWARD ACROSS THE FORECAST AREA SUNDAY NIGHT INTO MONDAY. WENT ON THE COOLER SIDE SIDE OF AVAILABLE GUIDANCE WITH RESPECT TO MIN TEMPERATURES SUNDAY NIGHT GIVEN CLEAR SKIES...LIGHT WINDS AND RATHER DRY DRY AIRMASS. MONDAY LOOKS LIKE A PLEASANT DAY WITH SUNNY SKIES...RELATIVELY LIGHT WINDS WITH DAYTIME HIGHS A FEW DEGREES ABOVE NORMAL. SHORTWAVE DISTURBANCE THEN FORECAST TO HEAD SOUTHEAST ACROSS SOUTHERN HUDSON BAY MONDAY NIGHT INTO EARLY TUESDAY. ASSOCIATED COLD FRONT WILL GET SHOVED SOUTHEAST TOWARD NORTHWEST WISCONSIN BY AROUND 06Z TUESDAY. APPEARS TO BE A PLUME OF HIGHER MID-LEVEL LAPSE RATES AND MODEST 850 WAA OUT AHEAD OF THIS SYSTEM. HOWEVER AVAILABLE MOISTURE IS SOMEWHAT LIMITED. THUS...HAVE MAINLY SMALL CHANCE POPS OVER NORTHWEST COUNTIES OVERNIGHT...THEN CARRY THESE SMALL POPS SOUTHEAST ACROSS THE AREA TUESDAY MORNING. MAJORITY OF GUIDANCE SUGGEST THAT FRONT WILL PASS SOUTHEAST OF THE FORECAST AREA BY ABOUT 18Z TUESDAY WITH CAA TO ENSUE DURING THE AFTERNOON. WEAK HIGH PRESSURE RETURNS TO THE AREA TUESDAY NIGHT INTO EARLY WEDNESDAY...WITH NEXT DISTURBANCE ALREADY APPROACHING THE NORTHERN MISSISSIPPI VALLEY BY WEDNESDAY MORNING. MODEL CONSENSUS SUGGESTS THIS SYSTEM WILL BE A BIT MORE POTENT AS IT TRAVERSES SOUTHEAST ACROSS THE FORECAST AREA THURSDAY. OPERATIONAL GFS AND ECMWF ARE A BIT FURTHER SOUTH WITH STRENGTHENING SURFACE LOW WHILE GEM A BIT FURTHER NORTH. BOTTOM LINE IS THAT IT LOOKS LIKE THERE WILL BE A PRETTY DECENT CHANCE FOR SHOWERS AND THUNDERSTORMS DURING THE DAY ON THURSDAY. BUMPED UP POPS FROM PREVIOUS FORECAST. SOME MODEL DIFFERENCES ON EVOLUTION OF UPPER TROUGH AND ASSOCIATED SURFACE LOW THURSDAY NIGHT INTO FRIDAY. SYSTEM DOES APPEARS TO SLOW DOWN SOMEWHAT AS IT DEEPENS JUST TO THE EAST OF THE FORECAST AREA...THUS PRECIPITATION COULD VERY WELL LINGER INTO FRIDAY ESPECIALLY OVER THE EASTERN HALF OF THE FORECAST AREA. CLOUDS...SCATTERED PRECIPITATION AND NORTHEASTERLY BOUNDARY LAYER FLOW ON FRIDAY WILL LIKELY HOLD TEMPERATURES MAINLY IN THE 70S. && .AVIATION...LINE OF STORMS FORECAST TO ENTER WESTERN PART OF FORECAST AREA BY 18Z...THEN MOVE EAST THROUGH AREA BY 00Z. IFR CONDITIONS CAN BE EXPECTED WITH STRONGER STORMS. WIND GUSTS OVER 40 KTS POSSIBLE WITH STORMS AT AIRPORTS IN CENTRAL AND EAST- CENTRAL WI. BEST CHANCE FOR SEVERE WILL BE OVER SOUTHERN PART OF STATE. JKL && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ JKL/ESB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1225 PM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH MONDAY 246 AM CDT SAT AUG 4 2012 MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY. SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO NORTHERN IOWA. ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI- RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO 40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING. ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA. THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA. WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP. SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL FOR LESS CONVECTION TO OCCUR. ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY 246 AM CDT SAT AUG 4 2012 THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY. && .AVIATION...THIS AFTERNOON THROUGH SUNDAY 1225 PM CDT SAT AUG 4 2012 LINE OF MVFR/IFR SHRA/TSRA WILL BE EXITING EAST OF KLSE BY 19Z WITH ONLY LINGERING -SHRA THRU 20Z. SMALL AREA OF POST-FRONTAL STRATO-CU IN THE 2500 TO 3500 FT RANGE WILL ROTATE ACROSS THE TAF SITES THRU ABOUT 21Z...BUT BE PROGRESSIVE WITH DECREASING CLOUDS/CLEARING SKIES FOR THE LATE AFTERNOON/EVENING HOURS AS A DRIER/COOLER AIRMASS AND SUBSIDENCE SPREAD ACROSS THE AREA. OF CONCERN IS THE MVFR CLOUD SHIELD OVER MUCH OF ND/NORTHERN MN...WRAPPED AROUND/BEHIND THE SFC-850BM LOW. INCREASING NORTHWEST FLOW BEHIND THE DEPARTING LOW/COLD FRONT WILL ADVECT THIS MOISTURE/CLOUDS SOUTHEAST TONIGHT. ADDED A PERIOD OF 2500-3000FT CLOUDS/CIGS TO BOTH KRST/LSE FOR THE LATE EVENING/OVERNIGHT HOURS AS THIS MOISTURE ROTATES ACROSS THE AREA. DRIER HIGH PRESSURE/ANTI-CYCLONIC FLOW BUILDS INTO THE AREA FOR SUN. WITH DIURNAL WARMING/MIXING GOOD VFR EXPECTED SUNDAY WITH ONLY SCT VFR CUMULUS..AND CLOUD BASES RISING THRU THE DAY. && .ARX WATCHES/WARNINGS/ADVISORIES... 246 AM CDT SAT AUG 4 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM....04 AVIATION.....RRS