Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/24/13


AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
736 PM MDT SUN JUN 23 2013 .UPDATE...SHORT WAVE TROUGH MOVING ACROSS THE REGION IS TRIGGERING THUNDERSTORMS OVER CENTRAL AND EASTERN COLORADO. BEST INSTABILITY REMAINS OVER FAR EASTERN COLORADO WHERE CAPES ARE AROUND 1000 J/KG. APPEARS THE BEST CHANCE FOR SEVERE STORMS WILL BE ACROSS SOUTHERN WASHINGTON...ELBERT AND LINCOLN COUNTIES. THE HRRR SHOWS CONVECTION OVER FAR NORTHEAST COLORADO THROUGH 09Z. FARTHER WEST...ISOLATED TO SCATTERED STORMS CONTINUE TO MOVE ACROSS THE MOUNTAINS AND FRONT RANGE. THESE STORMS ARE WEAKER AND ARE ONLY EXPECTED TO PRODUCE MODERATE TO BRIEF HEAVY RAIN...SMALL HAIL AND GUSTY WINDS. THE HRRR SHOWS ACTIVITY LINGERING UNTIL 09Z OVER WELD COUNTY. WILL ADJUST POPS TO LAST THROUGH 09Z...THOUGH EXPECT MOST OF THE ACTIVITY TO END BY 06Z. && .AVIATION...THUNDERSTORM ACTIVITY WILL CONTINUE IN THE DENVER AREA THROUGH AT LEAST 03Z. ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH 09Z...THOUGH MOST OF THE ACTIVITY WILL END MUCH SOONER AND CLOSER TO 03Z. WINDS WILL REMAIN ERRATIC THROUGH 03Z DUE TO OUTFLOW WINDS FROM THUNDERSTORMS. EVENTUALLY EXPECT WINDS TO BE SOUTHEAST AND THEN TURN SOUTH-SOUTHWEST AFTER 06Z. MONDAY WILL BE MUCH DRIER WITH SOUTHWEST WINDS PREVAILING. && .PREV DISCUSSION... /ISSUED 305 PM MDT SUN JUN 23 2013/ SHORT TERM...SHORT WAVE DISTURBANCE CONTINUES TO PROGRESS NORTHEASTWARD OVER UTAH AND SOUTHWEST COLORADO AT THIS HOUR. AT ITS CURRENT SPEED SHOULD SEE ITS AXIS PASSING OVER THE NORTH CENTRAL MTNS BY 00Z TODAY AND OVER THE FAR NERN PLAINS OF COLORADO BY 06Z TONIGHT. STRONG MID-LEVEL DESTABLIZATION IN WARM SECTOR OUT AHEAD OF THE S/W WILL COUPLE WITH SURFACE DEW POINTS IN THE 25-35 DEG RANGE TO PRODUCE WEAK PULSE-TYPE T-STORMS ALONG THE CONTINENTAL DIVIDE AND OVER THE FOOTHILLS DURING THE NEXT FEW HOURS. ONCE ON THE PLAINS...STORM DEVELOPMENT SHOULD BECOME MORE ORGANIZED...WITH STORMS FORMING IN THE VICINITY OF THE DENVER CYCLONE AND ALONG THE CONVERGENCE ZONE SOUTH OF THE LOW. SOUTHEASTERLY LOW-LEVEL FLOW ON THE PLAINS HAS SUPPRESSED DEW POINTS SOME IN THE PAST FEW HOURS...HOWEVER INTEGRATED PRECIPITABLE WATER VALUES HAVE CONTINUED TO CREEP UP THRU THE DAY TO AROUND 0.65 INCH AT DEN. FIRST WAVE OF LOW-TOP CONVECTION MOVING OFF THE FOOTHILLS AT THIS TIME WILL LIKELY PRODUCE OUTFLOW BOUNDARIES THAT STRONGER STORMS WILL LIKELY FORM ALONG LATER THIS AFTERNOON. SFC DEW POINTS IN THE 45-55 DEG F RANGE COMBINED WITH TEMPERATURES IN THE LOW/MID 80S AND VERY STEEP MID-LEVEL LAPSE RATES...AOA 8C/KM IN THE 700-500MB LAYER...WILL SUPPORT MEAN LAYER CAPE VALUES FROM 1300-2200 J/KG ON THE PLAINS BY 00Z/MONDAY. 15-20KT E-SELY LOW- LEVEL WINDS OVERLAYED BY 30KT MID-LEVEL W-SWLYS WILL ALSO GENERATE SUFFICIENT MEAN LAYER SHEAR FOR ISOLATED SUPERCELLS ON THE PLAINS...CAPABLE OF LARGE HAIL...DAMAGING WIND GUSTS AND PERHAPS A TORNADO OR TWO. AREAS TO THE EAST AND NORTHEAST OF DENVER IN THE BEST POSITION TO SEE THIS OCCURRING. STORMS IN THE DEEPER MOISTURE ACROSS THE NORTHEAST CORNER COULD POTENTIALLY PRODUCE 1 TO 1.5 INCHES OF RAIN IN A SHORT PERIOD OF TIME THIS EVENING. THE STORM PREDICTION CENTER CURRENTLY HAS NORTHEAST COLORADO IN A SLIGHT RISK FOR SEVERE HAIL AND WIND...WITH A BULLSEYE NEAR THE NORTHEAST CORNER. STORMS THIS EVENING MOVE EAST-NORTHEAST WITH THE PASSING SHORTWAVE TROUGH WITH THE BULK OF THIS ACTIVITY EXITING THE STATE BY AROUND 06Z/MIDNIGHT. TEMPERATURES TONIGHT ABOUT THE SAME AS LAST NIGHT UNDER CLEARING SKIES AFTER MIDNIGHT. ON MONDAY...THE FORECAST AREA COMES UNDER THE INFLUENCE OF STRONG MID-LEVEL SUBSIDENCE AND A MUCH DRIER AIRMASS WITH A VERY WARM SOUTHWEST FLOW ALOFT. STRONG SOLAR HEATING WILL IN TURN PRODUCE STEEP BOUNDARY LAYER LAPSE RATES BY AFTERNOON. SOUTH-SOUTHWEST SFC FLOW WILL PRETTY MUCH SCOUR OUT MUCH OF THE LOW-LEVEL MOISTURE NOW COVERING THE PLAINS. SO THE CHANCE FOR ANY CONVECTION/ T-STORMS APPEARS MINIMAL AT THIS TIME. CONCERNS TURN TO WILDLAND FIRE...AND ITS POTENTIAL FOR GROWTH. WILL BE ISSUING A FIREWEATHER WATCH FOR SOUTH PARK ZONE 214...MIDDLE PARK ZONE 213 AND THE PALMER DIVIDE ZONE 241 BASED ON LOW RH VALUES AND GUSTY SOUTHWEST WINDS. THIS WATCH WILL RUN FROM 1 PM MDT TO 8 PM MDT MONDAY. FINALLY TEMPERATURES ON MONDAY AS MUCH AS 10-12F WARMER THAN TODAY. LONG TERM...MODELS SHOW THE SOUTHWESTERLY FLOW ALOFT MONDAY NIGHT TO BECOME ZONAL BY TUESDAY AS A FLAT UPPER RIDGE SOUTH OF COLORADO MOVES THIS WAY. THE UPPER RIDGE AXIS BUILDS NORTHWARD TO THE WEST OF THE CWA TUESDAY NIGHT THROUGH WEDNESDAY NIGHT BRINGING NORTHWESTERLY FLOW ALOFT TO THE FORECAST AREA. THE SYNOPTIC SCALE ENERGY IS PROGGED TO BE BENIGN MONDAY NIGHT...THEN WEAK DOWNWARD QG VERTICAL VELOCITY IS PROGGED TUESDAY THROUGH WEDNESDAY. THE BOUNDARY LAYER FLOW IS DOMINATED BY DOWNSLOPING TUESDAY...THEN SOUTHEASTERLIES WEDNESDAY. FOR MOISTURE...MOST OF THE MODELS SHOW SOME IN THE MID AND UPPER LEVELS MOST OF THE PERIOD...HOWEVER BOUNDARY LAYER DEW POINTS ARE MAINLY IN THE LOWER 20S TO UPPER 30S F RANGE ALL FIVE PERIODS. THE ONE EXCEPTION BEING THE FAR NORTHEAST CORNER MONDAY EVENING...WHERE PROGGED VALUES GET INTO THE 40S F. ALSO...LATER ON WEDNESDAY THEY COME UP A BIT WITH THE SOUTHEASTERLY FLOW. THERE IS PRACTICALLY NO CAPE PROGGED OVER THE CWA ALL FIVE PERIODS...JUST A TAD OVER THE MOUNTAINS AND FOOTHILLS LATE DAY WEDNESDAY ON THE NAM ONLY. THERE IS NO MEASURABLE RAINFALL ON ANY OF THE MODEL`S QPF FIELDS ALL FIVE PERIODS. THERE IS AN OVERWHELMING MID LEVEL CAP OVER THE CWA ACCORDING TO THE LAPSE RATES FIELDS ALL THE PERIODS. NO POPS ANYWHERE. CONCERNING FIRE WEATHER ISSUES...WIND SPEEDS ARE RELATIVELY LOW MONDAY NIGHT INTO WEDNESDAY MORNING. WEDNESDAY AFTERNOON...THE SOUTHEASTERLIES OVER THE EASTERN HALF OF THE PLAINS COME UP TO NEAR 20 KNOTS. SOMETHING TO WATCH. FOR TEMPERATURES...TUESDAY`S HIGHS LOOK CLOSE TO MONDAY`S. WEDNESDAY`S ARE PROGGED UP 1-2 C FROM TUESDAY`S. FOR THE LATER DAYS...THURSDAY THROUGH SUNDAY...MODELS CONTINUE TO SHOW AN UPPER RIDGE RIGHT OVER OR PARTIALLY OVER COLORADO ALL FOUR DAYS. THE RIDGE AXIS IS STILL INDICATED WEST OF THE CWA WITH WEAK NORTHWESTERLY FLOW ALOFT FOR US. YESTERDAY`S 12Z MODEL RUNS INDICATED SOME COOLER AIR OVER THE PLAINS FOR FRIDAY AND SATURDAY. TODAY`S 12Z RUNS INDICATE ONLY A SLIGHTLY COOLER AIR MASS JUST ON FRIDAY NOW. MOISTURE LOOKS A LITTLE BETTER WITH THE LATEST RUNS...SO WILL GO WITH "SLIGHT CHANCE"S MOST LATE DAY PERIODS...MORE SO FOR THE MOUNTAINS AND FOOTHILLS. TEMPERATURES STAY ABOVE ALL FOUR DAYS. AVIATION...LOW-TOP CONVECTION NOW MOVING OVER THE DENVER METRO AREA. COULD SEE WIND GUSTS TO 40 MPH PRODUCED THIS FIRST WAVE OF MOSTLY DRY CLOUD CELLS. MEANWHILE A DENVER CYCLONE WILL CONTINUE TO FORM JUST TO THE NORTHEAST OF DENVER. WINDS ACROSS SOUTHERN PORTIONS OF THE DENVER METRO AREA SHOULD REMAIN SOUTHEASTERLY FOR THE NEXT FEW HOURS. WHILE WINDS OVER NORTHERN PORTIONS OF THE METRO AREA WILL TURN NORTH-NORTHEASTERLY. A CONVERGENCE BOUNDARY SETTING UP OVER THE SOUTH METRO AREA WILL ACT AS A FOCUS FOR STORM FORMATION IN THE NEXT 1-2 HOURS. STORMS IN THE DENVER METRO AREA...ESPLY SOUTHERN AND EASTERN PORTIONS...MAY GO SEVERE BETWEEN 4 PM AND 7 PM MDT. HAIL AND DAMAGING WIND MAIN THREAT. TERMINAL FORECASTS ALREADY HAVE A TEMPO FOR -TSRA AND STG WIND GUSTS AFTER 22Z TODAY. OVERNIGHT...SKIES CLEAR WITH DRIER AIR MOVING DOWN OFF THE FRONT RANGE AND PALMER DIVIDE. ON MONDAY...VFR CONDITIONS WILL PREVAIL WITH SOUTH-SOUTHWEST WINDS OF 5-12 KTS FOR MOST OF THE DAY. FIRE WEATHER...FIRE WEATHER WATCH 1 PM TO 8 PM MDT ON MONDAY FOR COZ213-214-241. LOW RELATIVE HUMIDITIES AND GUSTY SOUTHWEST WINDS TO 30 MPH WILL BE POSSIBLE IN THE AFTERNOON AND EARLY EVENING. HYDROLOGY...STRONG SLOW MOVING T-STORMS OVER THE NORTHEAST PLAINS THIS EVENING COULD DEPOSIT 1 TO 1.5 INCHES OF RAIN IN A SHORT PERIOD OF TIME. STORMS ELSEWHERE LATE THIS AFTERNOON AND EVENING ARE EXPECTED TO PRODUCE NOT MUCH MORE THAN A QUARTER OF RAIN. DRY WASHES AND ARROYOS ON THE PLAINS MAY PARTIALLY FILL WITH FAST MOVING RUNOFF FORM THESE HEAVY SHOWERS. && .BOU WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR COZ213-214-241. && $$ SHORT TERM...BAKER LONG TERM....RJK AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
323 PM MDT SAT JUN 22 2013 .SHORT TERM...UPPER LEVEL SHORTWAVE TROUGH NOW PASSING OVER THE NORTHERN ROCKIES WITH SOUTHWEST FLOW ALOFT OVER COLORADO. FURTHERMORE A SURFACE TROUGH EXTENDS NORTHWARD ALONG THE FRONT RANGE FROM A SURFACE LOW IN SOUTHEAST COLORADO. EAST OF THE TROUGH SFC DEWPOINTS IN THE MID TO UPPER 50S. WESTERN PORTIONS OF THE DENVER METRO AREA AND FOOTHILLS WEST OF THIS SFC TROUGH DEWPOINTS IN THE UPPER 30S AND 40S. ON THE PLAINS EVEN WITH THE HIGHER DEWPOINTS...BOUNDARY LAYER GENERALLY REMAINS CAPPED WITH LOW CIN VALUES BASED ON LAPS AND RAP MODEL...PARTICULARLY IN THE FAR NORTHEAST CORNER WHERE LOW CLOUDS FROM EARLIER TODAY HAVE BEEN RELUCTANT TO BURN AWAY. ISOLATED CONVECTION DEVELOPING OVER NORTHERN AND CENTRAL PORTIONS OF THE FRONT RANGE NOT PRODUCING MUCH PRECIP YET AS PER RADAR...BUT WITH THE DRY SUB-CLOUD ENVIRONMENT...POTENTIAL FOR STRONG/GUSTY MICROBURST WINDS PRETTY HIGH. IT NOW APPEARS THAT STORM DEVELOPMENT ON THE PLAINS WILL BEGIN ALONG THE PALMER DIVIDE AND ALONG A CONVERGENCE BOUNDARY STRADDLING THE DENVER METRO AREA WHERE THE CAP AND BROKEN. THESE STORMS SHOULD THEN TRACK NORTHEAST INTO DEEPER MOISTURE/GREATER CAPES WHERE A FEW MAY BECOME SEVERE. AT THIS TIME SHEAR PROFILE LOOKS MARGINAL FOR TORNADOES. BIGGEST THREAT FROM ISOLATED/WIDELY SCATTERED MESOS WILL BE LARGE HAIL AND DAMAGING OUTFLOW WINDS... AND PROBABLY NOT UNTIL AFTER 23Z THIS AFTERNOON. BELIEVE THE CHANCE FOR SEVERE WEATHER WILL INCREASE OVER THE FAR NORTHEAST CORNER OF THE STATE EARLY THIS EVENING WITH THE PASSAGE OF A WEAK UPPER AIR DISTURBANCE VISIBLE ON WATER VAPOR IMAGERY NOW OVER WRN WY/EXTREME NWRN CO. HAIL AT LEAST UP TO 2 INCHES AND WIND GUSTS TO AT LEAST 60 MPH A POSSIBILITY. OVERNIGHT...STORMS IN THE NORTHEAST SHOULD EITHER DISSIPATE OR MOVE EAST OF THE STATE...LEAVING BEHIND AMPLE LOW LEVEL MOISTURE IN THE FORM OF A THICK BLANKET OF STRATUS/STRATO-CUMULUS SIMILAR TO WHAT WE SAW THIS MORNING. DURING THE DAY TOMORROW SOUTHWEST FLOW ALOFT RESUMES BUT WITH A PRETTY VIGOROUS PERTABATION EMBEDDED IN THIS FLOW. MODELS SHOW THIS FEATURE LIFTING NORTHEAST ACROSS THE FORECAST AREA DURING THE AFTERNOON. MEANWHILE COUPLED CIRCULATION AROUND A SFC LOW IN SE COLORADO AND A STRONG SFC HIGH IN THE BLACK HILLS AREA WILL HELP TO FUNNEL LOW LEVEL MOISTURE INTO NORTHEAST COLORADO ON EAST-SOUTHEASTERLY WINDS. SUCH A BNDRY LAYER FLOW OFTEN GENERATES A DENVER CYCLE AS THE NAM INDICATES. THIS WOULD POTENTIALLY INCREASE THE RISK OF T-STORMS ALONG AND EAST OF THE FRONT RANGE AND PERHAPS A THREAT OF HAIL. WITH PW AND THETA-E VALUES ON THE RISE TOMORROW...LOCALLY HEAVY RAINFALL ALSO POSSIBLE SOMEWHERE ON THE PLAINS. COOLING ALOFT COUPLED WITH INCREASED MOISTURE/IE...CLOUD COVER/MEANS LOWER TEMPERATURES. MAX TEMPERATURES TOMORROW NEAR AVERAGE FOR THE DATE. FOR ALL OF THE SAME REASONS...RED FLAG WATCH/WARNING NOT NECESSARY. .LONG TERM...SOUTHWESTERLY FLOW ALOFT IS PROGGED FOR SUNDAY NIGHT...THEN ZONAL FLOW MOVES IN AND CONTINUES THROUGH TUESDAY NIGHT. SPEEDS ARE IN THE 30 TO 45 KNOT RANGE AT JET LEVEL ALL FIVE PERIODS. BENIGN SYNOPTIC SCALE ENERGY IS PROGGED THROUGH THE PERIODS. THE BOUNDARY LAYER FLOW IS PROGGED TO BE EASTERLY UP INTO THE FOOTHILLS SUNDAY EVENING. BY MONDAY AFTERNOON...SOUTHWESTERLY LOW LEVEL WINDS RETURN WITH PROGGED SPEEDS OVER THE SOUTH-CENTRAL AND EASTERN CWA GETTING AROUND 20 KNOTS. FOR MOISTURE...THERE IS SOME OVER THE EASTERN THREE-QUARTERS OF THE CWA SUNDAY EVENING. MODELS ALSO SHOW A STRATUS DECK OVER MUCH OF THE PLAINS LATER SUNDAY NIGHT INTO MONDAY MORNING. THERE IS LESS MOISTURE AROUND LATE DAY MONDAY...THEN EVEN LESS LATE DAY TUESDAY. SUNDAY NIGHT`S DEW POINT READINGS ARE PROGGED IN THE MID 40S TO UPPER 50S F FOR MOST OF THE PLAINS. BY MONDAY LATE DAY...ONLY THE FAR NORTHEASTERN BORDER HANGS ON TO 40S TO LOWER 50S F...THE REST OF THE PLAINS ARE IN THE DRY TEENS TO LOWER 30S F. ALL OF THE CWA IS PROGGED TO HAVE 20S TO MID 30S F ON TUESDAY. THERE IS CAPE OVER THE PLAINS AND MOST OF THE FOOTHILLS SUNDAY EVENING...WITH VALUES IN THE 1000-2000 J/KG RANGE OVER THE EASTERN HALF OF THE PLAINS. THE CAPE IS PUSHED TO THE FAR NORTHEAST CORNER FOR LATE DAY MONDAY...THEN NOTHING FOR LATE DAY TUESDAY. THE QPF FIELDS HAVE QUITE A BIT OF MEASURABLE RAINFALL OVER THE EASTERN HALF OF THE PLAINS SUNDAY EVENING. THEN THERE IS A TAD PROGGED OVER THE EASTERN BORDER LATE MONDAY ON THE GFS...THEN NOTHING ANY WHERE ON TUESDAY. FOR POPS...WILL GO WITH 10-30%S SUNDAY EVENING FROM THE DIVIDE THROUGH THE EASTERN BORDER. HIGHEST OVER THE EAST. FOR LATE DAY MONDAY ...JUST MINIMAL POPS OVER THE NORTHEAST CORNER. CONCERNING FIRE DANGER...THE WINDS GET MARGINALLY STRONG ENOUGH FOR RED FLAG CRITERIA FOR SOME OF THE CWA LATE DAY MONDAY. THE RELATIVE HUMIDITIES ARE MARGINAL AS WELL. NO HIGHLIGHTS JUST YET. FOR TEMPERATURES...MONDAY`S HIGHS CLIMB BACK UP 2-3.5 C ABOVE SUNDAY`S. TUESDAY`S ARE QUITE SIMILAR TO MONDAY`S. FOR THE LATER DAYS...WEDNESDAY THROUGH SATURDAY...MODELS SHOW AN UPPER RIDGE TO THE IMMEDIATE SOUTH OF COLORADO TO BUILD NORTHWARD UP INTO THE STATE WEDNESDAY AND THURSDAY. BY FRIDAY...THE CENTER IS OVER THE FOUR CORNERS AND IT`S AXIS IS NORTHWARD ACROSS EASTERN UTAH. BY SATURDAY...THE CENTER MIGRATES A BIT FURTHER WEST INTO THE EASTERN GREAT BASIN. THE CWA IS MOSTLY IN WEAK NORTHWESTERLY FLOW ALOFT ALL FOUR DAYS. THIS ALLOWS FOR A COOLER AIRMASS TO GET INTO THE CWA FRIDAY AND SATURDAY...WE`LL SEE. THERE IS ALSO A LITTLE BIT OF MOISTURE HERE AND THERE...BUT NOTHING SIGNIFICANT. TEMPERATURES ARE PRETTY HOT WEDNESDAY AND THURSDAY...THEN COOL OFF FRIDAY AND SATURDAY. && .AVIATION...ISOLATED STORMS MOVING OFF THE FOOTHILLS AND PALMER DIVIDE WILL MOST LIKELY BE HIGH BASED. THAT SAID...THESE CELL WILL HAVE THE POTENTIAL TO PRODUCE A LIGHT RAIN SHOWER...WIND GUSTS TO AT LEAST 40 MPH AND DANGEROUS CLOUD-TO-GROUND LIGHTNING. THIS STORM ACTIVITY IS LIKELY TO MOVE EAST OF THE DENVER METRO BY MID- EVENING. OVERNIGHT SKIES CLEAR...BUT COULD SEE LOW CLOUDS MOVING CLOSE TO DIA AROUND MORNING LIGHT. TOMORROW THERE IS A BETTER CHANCE FOR THUNDERSTORMS CERTAINLY BY AFTERNOON WITH PASSAGE OF AN UPPER LEVEL WEATHER DISTURBANCE. HAIL...STRONG GUSTY WINDS AND BRIEF HEAVY RAIN WILL BE POSSIBLE. COULD BRIEFLY SEE MVFR CONDITIONS WITH THIS AFTERNOON CONVECTION. && .FIRE WEATHER...RED FLAG WARNING WILL REMAIN IN EFFECT UNTIL 8 PM MDT THIS EVENING FOR COLORADO FIREWEATHER ZONES 211-213-214-216 AND 241. GUSTY WINDS...LOW RELATIVE HUMIDITIES AND DRY FUELS MAIN REASONS FOR THE WARNING. && .HYDROLOGY...STRONG SLOW MOVING T-STORMS OVER THE FAR NORTHEAST PLAINS THIS EVENING COULD DEPOSIT 1 TO 2 INCHES OF RAIN IN A SHORT PERIOD OF TIME. STORMS ELSEWHERE THIS AFTERNOON AND EVENING ARE NOT EXPECTED TO PRODUCE MUCH MORE THAN A QUARTER OF RAIN. && .BOU WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ211-213-214- 216-241. && $$ SHORT TERM...BAKER LONG TERM....RJK AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1135 AM MDT SAT JUN 22 2013 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 415 AM MDT SAT JUN 22 2013 WEAK OR SHALLOW FRONT IS LOCATED ACROSS MOFFAT/RIO BLANCO COUNTIES OF NW COLORADO AND NE UTAH. THERE IS SOME (NOT PLENTIFUL) MID LEVEL MOISTURE STREAMING ACROSS THIS BOUNDARY AS THE RADAR PICKS UP LOW DBZ RETURNS. VERNAL ASOS HAS STAYED CLR ALL NIGHT...INDICATING THAT CLOUD BASES ARE ABOVE 12K FEET. TROUGH AXIS OVER THE NRN INTERMOUNTAIN REGION LIFTS NORTHEAST TOWARD ERN MONTANA/NERN WYOMING THIS AFTERNOON. SHORT TERM RAP MODEL SHOWS DRIER AIR SPREADING INTO NE UTAH/NW COLORADO THIS AFTERNOON BEHIND THE TROUGH AXIS. WHILE THIS IS A REASONABLE SOLUTION...NOT UNUSUAL FOR AN ISOLATED THUNDERSTORM TO POP OVER THE ERN UINTAS ALONG THE TRAILING COLD FRONT. GFS40/NAM12 SHOW LOW END CONVECTIVE POTENTIAL ACROSS THE NRN MOUNTAINS. WILL MAKE A MINOR ADDITION TO THE FORECAST AND ADD ISOLATED THUNDERSTORMS OVER THE ERN UINTA MOUNTAINS. OTHERWISE NO CHANGES WITH SOUTHWEST FLOW AND DEEP MIXED LAYER WILL GENERATE AFTERNOON BREEZES IN THE 20-30 KT RANGE...ESPECIALLY PARTS OF NW COLORADO. TONIGHT AND SUNDAY... THE PERSISTENT SOUTHWEST FLOW THAT HAS BEEN IN PLACE WILL BE TEMPORARILY DISRUPTED TONIGHT AS A STRONGER PIECE OF ENERGY LIFTS ACROSS THE NORTHERN ROCKIES INTO THE NORTHERN PLAINS. THIS WILL TURN THE UPPER FLOW MORE WESTERLY AND HELP PUSH A FRONT INTO THE WESTERN AND NORTHERN 1/3 OF THE CWA BY MIDNIGHT. WE WILL BE IN THE SUBSIDENCE PORTION OF THE WAVE OVERNIGHT WHICH SHOULD HELP CLEAR THINGS OUT AND BRING SLIGHTLY STRONGER INVERSIONS AND COOLER TEMPERATURES TO MANY PLACES. THE FRONT WILL BE STALLING AND BECOMING ILL DEFINE BY SUNRISE ON SUNDAY. ALOFT THE SOUTHWESTERLY FLOW WILL BEGIN TO RE-ESTABLISH ITSELF AS UPSTREAM TROUGHING ONCE AGAIN MOVES ALONG THE WEST COAST. THERE WILL BE SOME MOISTURE TRAPPED IN THIS SOUTHWEST FLOW WITH AN ORIGIN ASSOCIATED WITH THE DEEP STREAM OF HIGH PWATS IN THE NORTHEAST PACIFIC. PWAT PLOTS OVER GJT SHOW THE NAM MUCH MORE GENEROUS NEAR A HALF OF AN INCH BY PEAK HEATING SUNDAY...WHILE THE GFS LAGS BELOW A THIRD OF AN INCH. BOTH MODELS INDICATE SOME WEAK BROAD SCALE ASCENT ASSOCIATED WITH EMBEDDED ENERGY IN THE FLOW AND THE SUB TROP JET ACROSS THE DESERT SOUTHWEST. WITH DRY LOW LAYERS THE FOCUS WILL REMAIN ACROSS THE RIDGETOPS WHERE MOST OF THE ACTION WILL JUST BE BUILDING CU. BETTER MOISTURE GETS PUSHED UP THE EASTERN DIVIDE IN THE WAKE OF AN FRONT RANGE FRONT. SO THE BEST CHANCES SEEM TO BE ALONG THE CENTRAL DIVIDE MOUNTAINS WHERE SMALL POPS WILL BE IN PLACE. TEMPERATURES REMAIN NEAR TO ABOVE NORMAL. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 415 AM MDT SAT JUN 22 2013 .SUNDAY NIGHT AND MONDAY... FORCING QUICKLY WANES SUNDAY NIGHT LEAVING DRY CONDITIONS GOING INTO MONDAY. THETA SURFACES BEGIN TO SHOW STRONG MOISTURE ADVECTION INTO THE WEST COAST WHICH WILL GRADUALLY BE PICKED UP BY THE SOUTHWEST FLOW AND DIRECTED TOWARD OUR CWA. HOWEVER THIS WILL NOT BE UNTIL THE MID WEEK PERIOD SO MONDAY LOOKS TO AGAIN REMAIN MAINLY PRECIPITATION FREE. WARM TEMPERATURES AND A BATCH OF MID LEVEL COOLING LOOKS TO BRING SOME GOOD AFTERNOON MIXING IN THIS WARM AIRMASS. OVERALL THE GRADIENT NOT QUITE AS STRONG AS THE PAST FEW DAYS BUT AFTERNOON GUSTY WINDS OVER 25 MPH MAY WIDESPREAD AND BRING ANOTHER ROUND OF CRITICAL FIRE WEATHER CONDITIONS. TUESDAY THROUGH FRIDAY... THE WESTERLIES RETREAT NORTHWARD ON TUESDAY...GUSTY AFTERNOON WINDS MAY STILL EXIST ACROSS THE NORTH. BUT LESS WIND CAN BE EXPECTED ACROSS THE SOUTH. FOR WEDENESDAY AND BEYOND...STRONG HIGH PRESSURE BECOMES ANCHORED OVER THE FOUR CORNER STATES. LESS WIND BUT TURNING HOTTER ACROSS THE ENTIRE AREA. ISOLATED HIGH BASED THUNDERSTORMS MAY POP OVER THE COLORADO HIGH COUNTRY...BUT THIS WILL BE DEPENDENT ON HOW MOISTURE WILL TRAPPED BENEATH THE SUBTROPICAL HIGH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1134 AM MDT SAT JUN 22 2013 AFTERNOON GUSTS OF 25-30KTS ARE EXPECTED OTHERWISE VFR PREVAILS. THERE IS A 20 PERCENT CHANCE OF -TSRA NORTH OF KVEL TIL 03Z THIS EVENING. && .FIRE WEATHER... ISSUED AT 415 AM SAT JUN 22 2013 FIRE ZONE 201 FUELS HAVE BEEN UPGRADED TO CRITICAL...HOWEVER HUMIDITY VALUES STAY ABOVE RED FLAG CRITERIA. WILL NOT HOIST A RED FLAG WARNING FOR ZONE 201. FOR THE REMAINDER OF THE AREA...DEEP MIXED LAYER AND A STRONG JUNE SUN MEANS ANOTHER DAY OF GUSTY WINDS AT MANY SPOTS. GUSTY WINDS AND LOW HUMIDITY WILL CONTINUE THROUGH THE REMAINDER OF THE WEEKEND...THE QUESTION BEING WHETHER THE WINDS WILL SURPASS CRITICAL CRITERIA ON SUNDAY. WINDS AT THIS POINT LOOK TO DECREASE UNDER HEADLINE THRESHOLDS THOUGH LOCAL GUSTS ARE EXPECTED IN THE AFTERNOON. ON MONDAY...NEGATIVELY TILTED TROUGH SWIPES NORTHERN REGION OF CWA AND MAY INCREASE WINDS DURING THE DAY. WILL BE MONITORING THIS THROUGH THE WEEKEND. TEMPERATURES LATE NEXT WEEK ASSOCIATED WITH THE BUILDING RIDGE WILL INCREASE WELL ABOVE NORMAL. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ200-202-203- 207-290>293. UT...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR UTZ486-487. && $$ SHORT TERM...PF/15 LONG TERM...15/PF AVIATION...JDC FIRE WEATHER...CC
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1120 AM MDT SAT JUN 22 2013 .UPDATE... && .SHORT TERM...TEMPERATURES ON THE PLAINS RUNNING BEHIND YESTERDAY AT THIS TIME BY 5-10 DEG F...AND 2-6 DEG F BEHIND IN THE HIGH COUNTRY. THEREFORE THE COOLER MAX TEMPERATURES ALREADY IN THE FCST LOOK GOOD. LOW CLOUDS BLANKETING MUCH OF NORTHEAST COLORADO EARLIER THIS MORNING AND STILL OUT NEAR THE NORTHEAST CORNER PARTLY TO BLAME FOR THE COOLER START TO THE DAY...EVEN WITH A VERY WARM SOUTHWEST FLOW ALOFT. THIS SWLY FLOW WILL LIKELY MIX DOWN TO THE SFC PRODUCING GUSTY SWLY WINDS IN THE MTN VALLEYS AND ALONG THE SRN FOOTHILLS OVER THE NEXT 1-3 HOURS. DEWPTS ALREADY QUITE LOW IN THESE AREAS...SO RED FLAG WARNING FOR THE MTN VALLEYS AND SRN FOOTHILLS LOOKS JUSTIFIED. WARNING BEGINS AT NOON MDT. MEANWHILE HAVE REACHED CONVECTIVE TEMPERATURES IN THE NORTHERN FOOTHILLS AND ALONG THE SPINE OF THE CONTINENTAL DIVIDE WHERE CU AND TCU ARE BEGINNING TO FORM. SHOULD SEE THIS PROGRESS CONTINUE THROUGH THE AFTERNOON AS MID-LEVEL MOISTURE FILTERS IN FROM UTAH AROUND THE BOTTOM SIDE OF AN UPPER TROUGH APPROACHING WRN WYOMING. HAVE INCREASED AFTERNOON POPS SLIGHTLY FOR THE NRN MTN RANGES AND NRN FOOTHILLS...HOWEVER STORMS IN THIS AREA LIKELY TO PRODUCE MORE GUSTY WIND THAN WETTING RAINFALL THRU EARLY THIS EVENING. ON THE PLAINS...PLENTY OF CIN OUT THERE NOW...EVEN WITH SFC DEWPOINTS IN THE MID/UPPER 50S EAST OF A FORT COLLINS-TO-LIMON LINE. MOISTURE LOOKS SHALLOW ON LAPS AND RUC SOUNDINGS AND CROSS SECTIONS. THROUGH THE AFTERNOON THE WEST SIDE OF THIS MOISTURE IS PROGGED TO MIGRATE EAST WITH DRIER SOUTHWESTERLY WINDS COMING OFF THE FOOTHILLS AND PALMER DIVIDE. BUT ITS OUT ACROSS THE NORTHEAST CORNER OF THE STATE WHERE LOW-LEVEL MOISTURE WILL HANG TIGHT WITH SFC BASED CAPES UP AROUND 2500 J/KG BY AROUND 00Z/SUN. SPC HAS THIS AREA UNDER A SLIGHT RISK FOR SVR T-STORMS. MAY TAKE MOST OF THE AFTERNOON FOR IT TO DEVELOP OUT THERE WITH ALL OF THE CIN...PROBABLY NOT UNTIL AFTER 21Z OR 22Z. DAMAGING T-STORM WINDS AND LARGE HAIL MAIN THREATS. SHOULD SEE MOST OF THIS CONVECTION WRAPPING UP BY 06Z TONIGHT. .AVIATION...VFR CONDITIONS ANTICIPATED AT DENVER AREA AIRPORTS TODAY AND TONIGHT. ISOLATED HIGH BASED AND MOSTLY DRY T-STORMS DRIFTING OFF THE FOOTHILLS LATE THIS AFTERNOON MAY PRODUCE SOME GUSTY WINDS...GENERALLY LESS THAN 30 KTS. LITTLE OR NO CHANCE OF WETTING RAINFALL. SKIES CLEAR OVERNIGHT. LIGHT AND VARIABLE WINDS AT THIS HOURS EXPECTED TO BECOME SOUTH-SOUTHWEST LATTER THIS AFTERNOON AT 7-14KTS...THEN DRAINAGE FLOW OVERNIGHT AT LIGHTER SPEEDS. && .FIRE WEATHER...RED FLAG WARNING GOES INTO EFFECT AT 12 PM MDT AND RUNS UNTIL 8 PM MDT THIS EVENING FOR COLORADO FIREWEATHER ZONES 211-213-214-216 AND 241. GUSTY WINDS...LOW RELATIVE HUMIDITIES AND DRY FUELS MAIN REASONS FOR THE WARNING. && .HYDROLOGY...STRONG STORMS OVER THE FAR NORTHEAST PLAINS THIS EVENING COULD DROP 1-2 INCHES OF RAIN IN A SHORT PERIOD OF TIME. OTHERWISE HEAVY RAIN OR FLOODING NOT EXPECTED ELSEWHERE. && .PREV DISCUSSION... /ISSUED 339 AM MDT SAT JUN 22 2013/ SHORT TERM...MAIN CONCERN AGAIN TODAY WILL BE THE SEVERE POTENTIAL OVER THE PLAINS AND FIRE WEATHER CONCERNS OVER THE SOUTHERN PORTION OF CWA. LITTLE CHANGE IN THE SYNOPTIC PATTERN WITH UPPER TROF OVER IDAHO AND MODEST SOUTHWEST FLOW OVER COLORADO. AT THE SURFACE...LOW PRESSURE OVER FAR EAST CENTRAL COLORADO WHILE SEVERAL SURGES FROM LAST NIGHT CONVECTION HAS REPLENISHED THE LOW LEVEL MOISTURE. SURFACE DEWPOINTS HAVE INCREASED INTO THE MID 40S TO MID 50S WHILE INTEGRATED PW VALUES ARE AROUND 6 TENTHS OF AN INCH OVER THE FRONT RANGE WHICH IS JUST SLIGHTLY DOWNWARD FROM 24 HOURS AGO. THIS MOISTURE WILL AGAIN FLUSH OUT AS THE DRIER AIR MIXES DOWN. THE QUESTION WILL BE WHERE WILL THE BOUNDARY END UP WITH THE DRIER AIR TO THE SOUTHWEST AND MORE MOIST AIR TO THE NORTHEAST. APPEARS STORMS MAY FIRE A BIT MORE TO THE SOUTHWEST THIS AFTERNOON VS. FRIDAY AND BEST GUESS WOULD BE ALONG A LINE FROM LIMON TO GREELEY AND POINTS NORTH AND EAST. LATEST WRF SIMULATED IMAGERY SHOWING SOMETHING SIMILAR TO ABOVE SCENARIO. STORMS THAT DO DEVELOP WILL PROBABLY BECOME SEVERE WITH SURFACE BASED CAPES FROM 2000-3000J/KG AND MODEST MID LEVEL FLOW. FURTHER WEST...WITH THE DRIER AIR MIXING DOWN THERE MAY BE SOME HIGH BASED SHOWERS WITH GUSTY WINDS THE MAIN THREAT. AS LIKE THIS NIGHT...EXPECT OUTFLOW BOUNDARIES TO USHER IN HIGHER LOW LEVEL MOISTURE BY SUNDAY MORNING. LONG TERM...SW FLOW ALOFT WILL REMAIN OVER THE AREA SUN AND MON. APPEARS ANOTHER WEAK COOL FNT WILL AFFECT NERN CO ON SUN WITH ESE LOW LVL FLOW WHICH SHOULD ALLOW DEEPER MOISTURE TO STAY IN PLACE ACROSS THE PLAINS AND POSSIBLY THE NRN FOOTHILLS. EXPECT THERE WILL BE A DENVER CYCLONE BY AFTN WITH A CONVERGENCE ZONE SETTING ALONG OR JUST EAST OF THE FRONT RANGE URBAN CORRIDOR. WITH A FAVORABLE SHEAR PROFILE IN PLACE AND CAPES BY AFTN RANGING FM 1500-2500 J/KG COULD SEE AN ACTIVE AFTN AND EVENING OVER THE NERN PLAINS. IN THE MTNS AND HIGHER VALLEYS DRIER AIR WILL REMAIN PLACE ALTHOUGH COULD SEE A FEW HIGH BASED STORMS EAST OF THE DIVIDE. FIRE DANGER WILL CONTINUE CRITICAL IN THE HIGHER VALLEYS AND OVER PARK COUNTY. AS FOR HIGHS TEMPS SHOULD BE A FEW DEGREES COOLER OVER NERN CO WITH READINGS MAINLY IN THE 80S. BY MON THE LOW LEVEL FLOW WILL BECOME MORE SLY ON MON OVER NERN CO WHICH WILL SCOUR OUT LOW LEVEL MOISTURE EXCEPT OVER THE FAR NERN PLAINS. THERE WILL BE SOME SFC CONVERGENCE AND HIGHER CAPES NORTHEAST OF A NEW RAYMER TO FORT MORGAN TO LIMON LINE SO MAY SEE A SLIGHT CHC OF TSTMS BY MID TO LATE AFTN. ELSEWHERE APPEARS A DRY AIRMASS WILL BE IN PLACE SO WILL KEEP THE REST OF THE AREA DRY. ONCE AGAIN FIRE DANGER WILL REMAIN VERY HIGH OVER THE HIGHER VALLEYS AND PARK COUNTY MON AFTN. HIGHS ON MON OVER NERN CO WILL RISE BACK INTO THE LOWER TO MID 90S. FOR TUE THE FLOW ALOFT WILL BECOME MORE WLY AS AN UPPER LEVEL RIDGE BEGINS TO BUILD OVER THE SRN ROCKIES WITH A VERY DRY AIRMASS IN PLACE. FIRE DANGER WILL REMAIN VERY HIGH ALTHOUGH LOW LEVEL WINDS MAY NOT BE QUITE AS GUSTY. HIGHS ON TUE WILL RISE INTO THE 90S ACROSS NERN CO. BY WED AND THU AN UPPER LEVEL HIGH WILL BE CENTERED OVER SWRN CO WITH WLY FLOW ALOFT ACROSS NRN CO. MOISTURE BOTH DAYS STILL LOOKS MEAGER SO WILL KEEP FCST DRY. HIGHS BOTH DAYS OVER NERN CO LOOK TO BE IN THE 95 TO 100 DEGREE RANGE. BY FRI BOTH THE ECMWF AND GFS MOVE THE UPPER LEVEL HIGH A LITTLE FURTHER WEST WHICH ALLOWS FOR THE FLOW ALOFT TO BECOME MORE NWLY. BOTH MODELS TRY TO ENTRAIN SOME SUB TROPICAL MOISTURE INTO THE FLOW AS A WEAK COOL FNT MOVES INTO NERN CO. THUS THIS MAY LEAD TO A SLIGHT CHC OF AFTN AND EVENING TSTMS OVER THE HIGHER TERRAIN AND THE PLAINS. AVIATION...NORTHWEST SURFACE WINDS TO GRADUALLY TURN NORTHEAST AND EAST BY EARLY AFTERNOON. THEN SOUTHWEST WINDS WILL BEGIN TO MIX DOWN BY LATE AFTERNOON. THUNDERSTORMS MAY GET A LITTLE CLOSER TODAY BUT STILL THINK MOST OF THE ACTIVITY WILL BE EAST AND NORTHEAST OF THE TERMINALS AND WON`T MENTION FOR NOW. FIRE WEATHER...A REPEAT PERFORMANCE THIS AFTERNOON WITH RED FLAG CONDITIONS AGAIN ACROSS MTN VALLEYS...PARK COUNTY AND PALMER DIVIDE. ZONE 216 IS BORDERLINE FOR THE GUSTY WINDS BUT LOOKS LIKE SHOULD BE A LITTLE STRONGER THAN FRIDAY AND WILL ADD TO THE RED FLAG WARNINGS. HYDROLOGY...STRONG STORMS OVER THE FAR NORTHEAST PLAINS COULD DROP 1-2 INCHES OF RAIN IN A SHORT PERIOD OF TIME. FURTHER WEST...VERY LITTLE RAINFALL EXPECTED OVER THE FRONT RANGE. && .BOU WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ211-213-214- 216-241. && $$ SHORT TERM...BAKER/ENTREKIN LONG TERM....RPK AVIATION...BAKER/ENTREKIN
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
415 AM MDT SAT JUN 22 2013 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 415 AM MDT SAT JUN 22 2013 WEAK OR SHALLOW FRONT IS LOCATED ACROSS MOFFAT/RIO BLANCO COUNTIES OF NW COLORADO AND NE UTAH. THERE IS SOME (NOT PLENTIFUL) MID LEVEL MOISTURE STREAMING ACROSS THIS BOUNDARY AS THE RADAR PICKS UP LOW DBZ RETURNS. VERNAL ASOS HAS STAYED CLR ALL NIGHT...INDICATING THAT CLOUD BASES ARE ABOVE 12K FEET. TROUGH AXIS OVER THE NRN INTERMOUNTAIN REGION LIFTS NORTHEAST TOWARD ERN MONTANA/NERN WYOMING THIS AFTERNOON. SHORT TERM RAP MODEL SHOWS DRIER AIR SPREADING INTO NE UTAH/NW COLORADO THIS AFTERNOON BEHIND THE TROUGH AXIS. WHILE THIS IS A REASONABLE SOLUTION...NOT UNUSUAL FOR AN ISOLATED THUNDERSTORM TO POP OVER THE ERN UINTAS ALONG THE TRAILING COLD FRONT. GFS40/NAM12 SHOW LOW END CONVECTIVE POTENTIAL ACROSS THE NRN MOUNTAINS. WILL MAKE A MINOR ADDITION TO THE FORECAST AND ADD ISOLATED THUNDERSTORMS OVER THE ERN UINTA MOUNTAINS. OTHERWISE NO CHANGES WITH SOUTHWEST FLOW AND DEEP MIXED LAYER WILL GENERATE AFTERNOON BREEZES IN THE 20-30 KT RANGE...ESPECIALLY PARTS OF NW COLORADO. TONIGHT AND SUNDAY... THE PERSISTENT SOUTHWEST FLOW THAT HAS BEEN IN PLACE WILL BE TEMPORARILY DISRUPTED TONIGHT AS A STRONGER PIECE OF ENERGY LIFTS ACROSS THE NORTHERN ROCKIES INTO THE NORTHERN PLAINS. THIS WILL TURN THE UPPER FLOW MORE WESTERLY AND HELP PUSH A FRONT INTO THE WESTERN AND NORTHERN 1/3 OF THE CWA BY MIDNIGHT. WE WILL BE IN THE SUBSIDENCE PORTION OF THE WAVE OVERNIGHT WHICH SHOULD HELP CLEAR THINGS OUT AND BRING SLIGHTLY STRONGER INVERSIONS AND COOLER TEMPERATURES TO MANY PLACES. THE FRONT WILL BE STALLING AND BECOMING ILL DEFINE BY SUNRISE ON SUNDAY. ALOFT THE SOUTHWESTERLY FLOW WILL BEGIN TO RE-ESTABLISH ITSELF AS UPSTREAM TROUGHING ONCE AGAIN MOVES ALONG THE WEST COAST. THERE WILL BE SOME MOISTURE TRAPPED IN THIS SOUTHWEST FLOW WITH AN ORIGIN ASSOCIATED WITH THE DEEP STREAM OF HIGH PWATS IN THE NORTHEAST PACIFIC. PWAT PLOTS OVER GJT SHOW THE NAM MUCH MORE GENEROUS NEAR A HALF OF AN INCH BY PEAK HEATING SUNDAY...WHILE THE GFS LAGS BELOW A THIRD OF AN INCH. BOTH MODELS INDICATE SOME WEAK BROAD SCALE ASCENT ASSOCIATED WITH EMBEDDED ENERGY IN THE FLOW AND THE SUB TROP JET ACROSS THE DESERT SOUTHWEST. WITH DRY LOW LAYERS THE FOCUS WILL REMAIN ACROSS THE RIDGETOPS WHERE MOST OF THE ACTION WILL JUST BE BUILDING CU. BETTER MOISTURE GETS PUSHED UP THE EASTERN DIVIDE IN THE WAKE OF AN FRONT RANGE FRONT. SO THE BEST CHANCES SEEM TO BE ALONG THE CENTRAL DIVIDE MOUNTAINS WHERE SMALL POPS WILL BE IN PLACE. TEMPERATURES REMAIN NEAR TO ABOVE NORMAL. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 415 AM MDT SAT JUN 22 2013 .SUNDAY NIGHT AND MONDAY... FORCING QUICKLY WANES SUNDAY NIGHT LEAVING DRY CONDITIONS GOING INTO MONDAY. THETA SURFACES BEGIN TO SHOW STRONG MOISTURE ADVECTION INTO THE WEST COAST WHICH WILL GRADUALLY BE PICKED UP BY THE SOUTHWEST FLOW AND DIRECTED TOWARD OUR CWA. HOWEVER THIS WILL NOT BE UNTIL THE MID WEEK PERIOD SO MONDAY LOOKS TO AGAIN REMAIN MAINLY PRECIPITATION FREE. WARM TEMPERATURES AND A BATCH OF MID LEVEL COOLING LOOKS TO BRING SOME GOOD AFTERNOON MIXING IN THIS WARM AIRMASS. OVERALL THE GRADIENT NOT QUITE AS STRONG AS THE PAST FEW DAYS BUT AFTERNOON GUSTY WINDS OVER 25 MPH MAY WIDESPREAD AND BRING ANOTHER ROUND OF CRITICAL FIRE WEATHER CONDITIONS. TUESDAY THROUGH FRIDAY... THE WESTERLIES RETREAT NORTHWARD ON TUESDAY...GUSTY AFTERNOON WINDS MAY STILL EXIST ACROSS THE NORTH. BUT LESS WIND CAN BE EXPECTED ACROSS THE SOUTH. FOR WEDENESDAY AND BEYOND...STRONG HIGH PRESSURE BECOMES ANCHORED OVER THE FOUR CORNER STATES. LESS WIND BUT TURNING HOTTER ACROSS THE ENTIRE AREA. ISOLATED HIGH BASED THUNDERSTORMS MAY POP OVER THE COLORADO HIGH COUNTRY...BUT THIS WILL BE DEPENDENT ON HOW MOISTURE WILL TRAPPED BENEATH THE SUBTROPICAL HIGH. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 415 AM MDT SAT JUN 22 2013 AFTERNOON GUSTS OF 25-30KTS ARE EXPECTED OTHERWISE VFR PREVAILS. THERE IS A 20 PERCENT CHANCE OF AN AFTERNOON -TSRA NORTH OF KVEL. && .FIRE WEATHER... ISSUED AT 415 AM SAT JUN 22 2013 FIRE ZONE 201 FUELS HAVE BEEN UPGRADED TO CRITICAL...HOWEVER HUMIDITY VALUES STAY ABOVE RED FLAG CRITERIA. WILL NOT HOIST A RED FLAG WARNING FOR ZONE 201. FOR THE REMAINDER OF THE AREA...DEEP MIXED LAYER AND A STRONG JUNE SUN MEANS ANOTHER DAY OF GUSTY WINDS AT MANY SPOTS. GUSTY WINDS AND LOW HUMIDITY WILL CONTINUE THROUGH THE REMAINDER OF THE WEEKEND...THE QUESTION BEING WHETHER THE WINDS WILL SURPASS CRITICAL CRITERIA ON SUNDAY. WINDS AT THIS POINT LOOK TO DECREASE UNDER HEADLINE THRESHOLDS THOUGH LOCAL GUSTS ARE EXPECTED IN THE AFTERNOON. ON MONDAY...NEGATIVELY TILTED TROUGH SWIPES NORTHERN REGION OF CWA AND MAY INCREASE WINDS DURING THE DAY. WILL BE MONITORING THIS THROUGH THE WEEKEND. TEMPERATURES LATE NEXT WEEK ASSOCIATED WITH THE BUILDING RIDGE WILL INCREASE WELL ABOVE NORMAL. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR COZ200-202-203-207-290>293. UT...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR UTZ486-487. && $$ SHORT TERM...PF/15 LONG TERM...15/PF AVIATION...PF FIRE WEATHER...CC
AREA FORECAST DISCUSSION
NWS ALBANY NY
659 PM EDT SAT JUN 22 2013 .SYNOPSIS... WARM AND HUMID CONDITIONS WILL CONTINUE THROUGH THE REMAINDER OF THE WEEKEND AND INTO THE START OF THE NEW WORK WEEK. THERE WILL BE THE CHANCE FOR MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS UNDER VARIABLE CLOUDS. && .NEAR TERM /THROUGH SUNDAY/... AS OF 645 PM EDT...THE TREND DURING THE PAST HOUR OR SO IS THAT SCATTERED SHOWERS HAVE BECOME LESS SCATTERED. A WEAK DISTURBANCE HAS SET THEM OFF...BUT THE RUC ANALYSIS ASSOCIATED WITH THIS SHORT WAVE APPEARS TO BE WEAKENING. THE HRRR AND 18Z NAM INDICATE THIS WILL INDEED BE THE CASE. HOWEVER...THE WFOWRF HAS INDICATED OTHERWISE...THAT THESE SHOWERS WILL BECOME ENHANCED AND PROBABLY CONTAIN THUNDER AS WELL. HOWEVER...LOOKING AT SPC PARAMETERS IT APPEARS THAT THERE WILL NOT BE AN INCREASE IN MOISTURE OR INSTABILITY (ACTUALLY SHOULD BE LOWERING WITH LOSS OF HEATING). FORCING APPEARS RATHER MINIMAL AT THIS TIME WITH THE BEST LOW LEVEL JET CORE ACROSS THE ST LAWRENCE VALLEY. BELIEVE THE WFOWRF IS PROBABLY NOT CORRECT BUT IT IS CERTAINLY POSSIBLE. FOR THIS UPDATE FOLLOWED THE PREVIOUS FORECASTER`S THINKING ALTHOUGH I TRIMMED DOWN POPS A LITTLE AND ONLY INCLUDE A CHANCE OF THUNDER SINCE THERE HAVE BEEN VIRTUALLY NO CGS OVER OUR REGION SO FAR. CLOUDS WILL CONTINUE TO INCREASE FOR AWHILE AND ISOLATED SHOWERS SHOULD MAKE IT INTO THE CAPITAL REGION AND EVEN SOUTH...BUT AGAIN NOT EVERYONE WILL HAVE SEE A SHOWER. FOR THE REST OF THE DAYLIGHT HOURS...LOOK FOR MOST OF US TO REMAIN RAIN FREE BUT SHOWER IS POSSIBLE FROM THE CAPITAL DISTRICT NORTHWARD. IT WILL REMAIN SOMEWHAT HUMID AND WARM WITH TEMPERATURES ONLY VERY SLOW TO FALL BACK INTO THE MID AND UPPER 70S. A SOUTH WIND WILL AVERAGE 5 TO 10 MPH. CLOUD COVER FORECAST TONIGHT WILL BE PROBLEMATIC AS CONVECTIVE DEBRIS ALONG WITH A INCREASE IN LOW LEVEL MOISTURE COULD RESULT IN TWO CLOUD LAYERS /THE BEST POTENTIAL ALONG AND NORTH OF I90/. SO FOR NOW...WE WILL CALL IT PT-MOCLOUDY AND KEEP OVERNIGHT LOW TEMPS A BIT MILD AND CLOSER THE MET MOS VALUES WHICH IS IN AGREEMENT WITH THE HOURLY LAV/LAMP. LOWS FOR LOWS IN THE 60S...UPPER 60S LOCALLY IN THE TRI-CITY REGION. ALL INDICATIONS THOUGH POINT TO AN INCREASE IN CLOUD COVER THIS EVENING...DECREASING OVERNIGHT. DID TWEAK THE CLOUD COVER A BIT AS WELL ESPECIALLY DURING THE OVERNIGHT. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... WITH A LACK OF STRONG FORCING MECHANISMS IN THE SHORT TERM COMBINING WITH INCREASE WARMTH AND HUMID CONDITIONS AROUND THE PERIPHERY OF BERMUDA HIGH...THE CHANCE FOR MAINLY AFTERNOON AND EARLY EVENING SHOWERS/THUNDERSTORMS. LAPSE RATES ARE MARGINAL WITH VALUES LESS THAN 6/KM IN THE H850-500 LAYER...HOWEVER...SBCAPES ARE EXPECTED TO RANGE BETWEEN 1K-2K J/KG DURING THE PEAK HEATING AS TEMPERATURES CLIMB WELL INTO THE 80S FOR MANY LOCATIONS. OVERNIGHT LOWS WILL GENERALLY RANGE IN THE 60S...BUT WOULD NOT BE RULE OUT OUR FIRST 70 DEGREE OVERNIGHT LOW DURING THE NEXT COUPLE OF NIGHTS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THE WEATHER PATTERN LOOKS UNSETTLED THROUGHOUT THE EXTENDED PERIOD. THE WEAK RIDGE TO OUR SOUTH LOOKS TO SLOWLY RETROGRADE WESTWARD...STRENGTHENING AS IT SETS UP SHOP OVER THE WESTERN CONUS BY LATE IN THE WEEK. IN RESPONSE...IT LOOKS AS IF A LONG WAVE TROUGH WILL SLOWLY DIG INTO THE EASTERN CONUS. THE DEVIL IN THE DETAILS ARE HARD TO PINPOINT AT THIS TIME. WHAT WE DO KNOW IS THAT TEMPERATURES WILL SLOWLY COOL DOWN...AND BY NEXT WEEKEND...SHOULD BE RUNNING SLIGHTLY BELOW NORMAL. THE TRICKIER PART IS TIMING SPECIFIC DISTURBANCES THAT WILL PROVIDE A FOCUS FOR SHOWER AND THUNDERSTORMS. IT LOOKS AS IF TUESDAY WE WILL STILL BE IN A SOUPY AIR MASS WITH STILL NO GOOD TRIGGER OTHER THAN DIURNAL HEATING TO SPARK SHOWERS AND THUNDERSTORMS. SO ON THAT DAY...WENT WITH SLIGHT CHANCES OF SHOWERS EARLY...LOW POPS (30 PERCENT CHANCES) OF SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON AND EVENING HOURS. TEMPERATURES WILL CLIMB WELL INTO THE 80S...POSSIBLY TOUCHING 90 IN THE VALLEY AREAS SOUTH OF ALBANY. IT WILL BE RATHER HUMID AS WELL. WEDNESDAY...A WEAK COLD FRONTS LOOKS TO CROSS THE REGION SOMETIME DURING THE DAY...TRIGGERING AGAIN MAINLY LATE AFTERNOON AND EVENING THUNDERSTORMS. TEMPERATURES LOOK SLIGHTLY COOLER BUT STILL WARM...WELL INTO THE 80S MOST PLACES AND STILL A BIT HUMID. A VERY WEAK HIGH PRESSURE MIGHT BRIEFLY BUILD IN WEDNESDAY NIGHT INTO EARLY THURSDAY SO WHILE WE CANNOT ENTIRELY RULE OUT SHOWERS (20 POPS) WE BELIEVE THIS COULD BE A BRIEF "DRIER" PERIOD WITH SLIGHTLY LOWER HUMIDITY. LATER THURSDAY...ALL MODELS INDICATE SURFACE LOW PRESSURE AT THE SURFACE AND ALOFT WILL HEAD FROM THE GREAT LAKES TOWARD OUR REGION. THIS SYSTEM LOOKS TO BE THE ONE THAT REALLY BEGINS TO BUCKLE THE RIDGE IN THE EAST. THIS SYSTEM COULD BRING AN ORGANIZED AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS (POSSIBLY EVEN A MULTIPLE CONVECTIVE SYSTEM - MCS) OUR WAY LATE THURSDAY INTO FRIDAY. HIGHS BOTH THURSDAY AND FRIDAY LOOK TO BE IN THE MID TO UPPER 70S ACROSS THE HIGHER TERRAIN...AROUND 80 IN THE VALLEYS. IF EITHER DAY TURNS OUT TO BE A WASHOUT (A POSSIBILITY)...TEMPERATURES WOULD BE A LITTLE LOWER. THEN...YET ANOTHER LOW PRESSURE AREA AT THE SURFACE AND ALOFT COULD BRING YET ANOTHER ROUND OF DISTURBED WEATHER ON FRIDAY INTO EARLY SATURDAY. WHILE THE 12Z EUROPEAN HAS A SURFACE LOW MOVING ON BY SATURDAY...LOW PRESSURE ALOFT LINGERS ACROSS THE GREAT LAKES WHICH WOULD COOL THE MID AND UPPER LEVELS OF THE ATMOSPHERE TO KEEP THE THREAT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AROUND...ESPECIALLY SATURDAY AFTERNOON. HIGHS SATURDAY MIGHT BE MAINLY IN THE 70S...EXCEPT LOWER 80S ACROSS THE MID HUDSON VALLEY. OVERNIGHT LOWS THROUGHOUT THE PERIOD WILL GENERALLY BE IN THE 60S...EXCEPT SOME 50S ACROSS THE HIGHER TERRAIN BY FRIDAY NIGHT. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... A NEARLY STATIONARY FRONTAL BOUNDARY WILL REMAIN LOCATED JUST NORTH OF THE UNITED STATES/CANADIAN BORDER. A WEAK DISTURBANCE WILL PASS ALONG THIS BOUNDARY LATER TODAY. FLYING CONDITIONS ARE CURRENTLY VFR WITH MAINLY JUST SOME SCT HIGH CLOUDS OVER THE AREA. VFR CONDITIONS LOOK TO CONTINUE THROUGH THE AFTERNOON AND INTO THE EVENING...AS LOWER TO MID LEVEL CLOUDS START TO INCREASE AS THE WEAK DISTURBANCE MOVES ALONG THE BOUNDARY TO OUR NORTH. A FEW PASSING SHOWERS AND AN ISOLD THUNDERSTORM ARE POSSIBLE BY THIS EVENING INTO TONIGHT...ALTHOUGH SINCE COVERAGE WILL BE FAIRLY LIMITED...WE WILL LIMIT MENTION TO JUST VCSH FOR THE NORTHERN TERMINALS OF KGFL/KALB/KPSF. DUE TO THE CLOUDS AND A LIGHT SOUTHERLY BREEZE OVERNIGHT...NO FOG IS ANTICIPATED AT KGFL/KALB. CLOUDS MAY BE THINNER AT KPSF/KPOU AND IF WINDS LIGHTEN UP ENOUGH AFTER MIDNIGHT...THEN SOME BR/FG MAY BE POSSIBLE. FOR NOW...WILL LIMIT TO JUST MVFR DUE TO THE UNCERTAINTY ON TIMING/EXTENT AFTER ABOUT 07Z. AFTER SUNRISE...ANY FOG SHOULD DISSIPATE AND VFR CONDITIONS WILL BE IN PLACE FOR ALL TERMINALS. CLOUDS SHOULD SCT OUT FOR THE REMAINDER OF THE MORNING AND EARLY AFTN...ALTHOUGH ADDITIONAL SHOWERS ARE POSSIBLE LATER ON SUNDAY. OUTLOOK... SUN PM-THU...MAINLY VFR. CHC -TSRA/-SHRA MAINLY DURING THE AFTN INTO THE EVNG. && .FIRE WEATHER... AS HIGHER LOWER LEVEL MOISTURE CONTINUES TO ADVECT INTO THE REGION...OVERNIGHT DEW FORMATION ALONG WITH THE CHANCE FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL KEEP THE LOW LEVELS RATHER MOIST THE NEXT FEW DAYS. && .HYDROLOGY... OVERALL...FLOWS WILL CONTINUE TO GRADUALLY LOWER CLOSER TO SEASONAL NORMAL LEVELS OVER THE NEXT 5 DAYS. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK...HOWEVER WIDESPREAD RAINFALL IS NOT ANTICIPATED AT THIS TIME...AND NOT ALL LOCATIONS WILL RECEIVE THE RAINFALL. AS THE AIR MASS GETS MORE HUMID...SLOW MOVING THUNDERSTORMS COULD PRODUCE A QUICK INCH OR SO OF RAINFALL WITH HIGHER THAN NORMAL PWAT VALUES OVER THE HSA. SOME POOR DRAINAGE FLOODING OF LOW LYING AREAS...AND PONDING OF WATER ON ROADWAYS WILL BE POSSIBLE ANY DAY. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...BGM NEAR TERM...HWJIV/BGM SHORT TERM...BGM LONG TERM...HWJIV AVIATION...FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
355 PM EDT SAT JUN 22 2013 .SYNOPSIS... WARM AND HUMID CONDITIONS WILL CONTINUE THROUGH THE REMAINDER OF THE WEEKEND AND INTO THE START OF THE NEW WORK WEEK. THERE WILL BE THE CHANCE FOR MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS UNDER VARIABLE CLOUDS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... REGIONAL RADARS THIS AFTERNOON SHOW A WEAK COMPLEX OF CONVECTION ACROSS LAKE ONTARIO WITH MINIMAL CG/S PER THE NLDN. THIS APPEARS...PER THE H2O VAPOR LOOP...TO BE ASSOCIATED WITH A WEAK SHORT WAVE THAT THE LATEST RAP MODEL SUGGESTS WILL MOVE ACROSS THE NORTHERN 2/3RDS OF THE REGION THROUGH THIS EVENING. WE WILL PLACE POPS AOA 20-30% AS THE LEADING EDGE WOULD APPROACH AT THE TIME WHEN THE SUN IS CLOSE TO SETTING FURTHER REDUCING INSTABILITY. IN FACT...LATEST RUN OF THE HRRR AND 4KM SPC WRF REFLECTIVITIES SUGGEST THIS INITIAL BATCH WOULD WEAKEN AND ATTEMPT TO REDEVELOP NORTH OF I90 OVERNIGHT. THIS SECOND SURGE WOULD BE ON THE LEADING EDGE OF ADDITIONAL WARMTH AND HUMIDITY AS SEEN IN THE THETA-E FIELDS. HOWEVER...FORCING APPEARS RATHER MINIMAL AT THIS TIME WITH THE BEST LOW LEVEL JET CORE ACROSS THE ST LAWRENCE VALLEY. CLOUD COVER FORECAST WILL BE PROBLEMATIC AS CONVECTIVE DEBRIS ALONG WITH A INCREASE IN LOW LEVEL MOISTURE COULD RESULT IN TWO CLOUD LAYERS /THE BEST POTENTIAL ALONG AND NORTH OF I90/. SO FOR NOW...WE WILL CALL IT PT-MOCLOUDY AND KEEP OVERNIGHT LOW TEMPS A BIT MILD AND CLOSER THE MET MOS VALUES WHICH IS IN AGREEMENT WITH THE HOURLY LAV/LAMP. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... WITH A LACK OF STRONG FORCING MECHANISMS IN THE SHORT TERM COMBINING WITH INCREASE WARMTH AND HUMID CONDITIONS AROUND THE PERIPHERY OF BERMUDA HIGH...THE CHANCE FOR MAINLY AFTERNOON AND EARLY EVENING SHOWERS/THUNDERSTORMS. LAPSE RATES ARE MARGINAL WITH VALUES LESS THAN 6/KM IN THE H850-500 LAYER...HOWEVER...SBCAPES ARE EXPECTED TO RANGE BETWEEN 1K-2K J/KG DURING THE PEAK HEATING AS TEMPERATURES CLIMB WELL INTO THE 80S FOR MANY LOCATIONS. OVERNIGHT LOWS WILL GENERALLY RANGE IN THE 60S...BUT WOULD NOT BE RULE OUT OUR FIRST 70 DEGREE OVERNIGHT LOW DURING THE NEXT COUPLE OF NIGHTS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THE WEATHER PATTERN LOOKS UNSETTLED THROUGHOUT THE EXTENDED PERIOD. THE WEAK RIDGE TO OUR SOUTH LOOKS TO SLOWLY RETROGRADE WESTWARD...STRENGTHENING AS IT SETS UP SHOP OVER THE WESTERN CONUS BY LATE IN THE WEEK. IN RESPONSE...IT LOOKS AS IF A LONG WAVE TROUGH WILL SLOWLY DIG INTO THE EASTERN CONUS. THE DEVIL IN THE DETAILS ARE HARD TO PINPOINT AT THIS TIME. WHAT WE DO KNOW IS THAT TEMPERATURES WILL SLOWLY COOL DOWN...AND BY NEXT WEEKEND...SHOULD BE RUNNING SLIGHTLY BELOW NORMAL. THE TRICKIER PART IS TIMING SPECIFIC DISTURBANCES THAT WILL PROVIDE A FOCUS FOR SHOWER AND THUNDERSTORMS. IT LOOKS AS IF TUESDAY WE WILL STILL BE IN A SOUPY AIR MASS WITH STILL NO GOOD TRIGGER OTHER THAN DIURNAL HEATING TO SPARK SHOWERS AND THUNDERSTORMS. SO ON THAT DAY...WENT WITH SLIGHT CHANCES OF SHOWERS EARLY...LOW POPS (30 PERCENT CHANCES) OF SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON AND EVENING HOURS. TEMPERATURES WILL CLIMB WELL INTO THE 80S...POSSIBLY TOUCHING 90 IN THE VALLEY AREAS SOUTH OF ALBANY. IT WILL BE RATHER HUMID AS WELL. WEDNESDAY...A WEAK COLD FRONTS LOOKS TO CROSS THE REGION SOMETIME DURING THE DAY...TRIGGERING AGAIN MAINLY LATE AFTERNOON AND EVENING THUNDERSTORMS. TEMPERATURES LOOK SLIGHTLY COOLER BUT STILL WARM...WELL INTO THE 80S MOST PLACES AND STILL A BIT HUMID. A VERY WEAK HIGH PRESSURE MIGHT BRIEFLY BUILD IN WEDNESDAY NIGHT INTO EARLY THURSDAY SO WHILE WE CANNOT ENTIRELY RULE OUT SHOWERS (20 POPS) WE BELIEVE THIS COULD BE A BRIEF "DRIER" PERIOD WITH SLIGHTLY LOWER HUMIDITY. LATER THURSDAY...ALL MODELS INDICATE SURFACE LOW PRESSURE AT THE SURFACE AND ALOFT WILL HEAD FROM THE GREAT LAKES TOWARD OUR REGION. THIS SYSTEM LOOKS TO BE THE ONE THAT REALLY BEGINS TO BUCKLE THE RIDGE IN THE EAST. THIS SYSTEM COULD BRING AN ORGANIZED AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS (POSSIBLY EVEN A MULTIPLE CONVECTIVE SYSTEM - MCS) OUR WAY LATE THURSDAY INTO FRIDAY. HIGHS BOTH THURSDAY AND FRIDAY LOOK TO BE IN THE MID TO UPPER 70S ACROSS THE HIGHER TERRAIN...AROUND 80 IN THE VALLEYS. IF EITHER DAY TURNS OUT TO BE A WASHOUT (A POSSIBILITY)...TEMPERATURES WOULD BE A LITTLE LOWER. THEN...YET ANOTHER LOW PRESSURE AREA AT THE SURFACE AND ALOFT COULD BRING YET ANOTHER ROUND OF DISTURBED WEATHER ON FRIDAY INTO EARLY SATURDAY. WHILE THE 12Z EUROPEAN HAS A SURFACE LOW MOVING ON BY SATURDAY...LOW PRESSURE ALOFT LINGERS ACROSS THE GREAT LAKES WHICH WOULD COOL THE MID AND UPPER LEVELS OF THE ATMOSPHERE TO KEEP THE THREAT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AROUND...ESPECIALLY SATURDAY AFTERNOON. HIGHS SATURDAY MIGHT BE MAINLY IN THE 70S...EXCEPT LOWER 80S ACROSS THE MID HUDSON VALLEY. OVERNIGHT LOWS THROUGHOUT THE PERIOD WILL GENERALLY BE IN THE 60S...EXCEPT SOME 50S ACROSS THE HIGHER TERRAIN BY FRIDAY NIGHT. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... A NEARLY STATIONARY FRONTAL BOUNDARY WILL REMAIN LOCATED JUST NORTH OF THE UNITED STATES/CANADIAN BORDER. A WEAK DISTURBANCE WILL PASS ALONG THIS BOUNDARY LATER TODAY. FLYING CONDITIONS ARE CURRENTLY VFR WITH MAINLY JUST SOME SCT HIGH CLOUDS OVER THE AREA. VFR CONDITIONS LOOK TO CONTINUE THROUGH THE AFTERNOON AND INTO THE EVENING...AS LOWER TO MID LEVEL CLOUDS START TO INCREASE AS THE WEAK DISTURBANCE MOVES ALONG THE BOUNDARY TO OUR NORTH. A FEW PASSING SHOWERS AND AN ISOLD THUNDERSTORM ARE POSSIBLE BY THIS EVENING INTO TONIGHT...ALTHOUGH SINCE COVERAGE WILL BE FAIRLY LIMITED...WE WILL LIMIT MENTION TO JUST VCSH FOR THE NORTHERN TERMINALS OF KGFL/KALB/KPSF. DUE TO THE CLOUDS AND A LIGHT SOUTHERLY BREEZE OVERNIGHT...NO FOG IS ANTICIPATED AT KGFL/KALB. CLOUDS MAY BE THINNER AT KPSF/KPOU AND IF WINDS LIGHTEN UP ENOUGH AFTER MIDNIGHT...THEN SOME BR/FG MAY BE POSSIBLE. FOR NOW...WILL LIMIT TO JUST MVFR DUE TO THE UNCERTAINTY ON TIMING/EXTENT AFTER ABOUT 07Z. AFTER SUNRISE...ANY FOG SHOULD DISSIPATE AND VFR CONDITIONS WILL BE IN PLACE FOR ALL TERMINALS. CLOUDS SHOULD SCT OUT FOR THE REMAINDER OF THE MORNING AND EARLY AFTN...ALTHOUGH ADDITIONAL SHOWERS ARE POSSIBLE LATER ON SUNDAY. OUTLOOK... SUN PM-THU...MAINLY VFR. CHC -TSRA/-SHRA MAINLY DURING THE AFTN INTO THE EVNG. && .FIRE WEATHER... AS HIGHER LOWER LEVEL MOISTURE CONTINUES TO ADVECT INTO THE REGION...OVERNIGHT DEW FORMATION ALONG WITH THE CHANCE FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL KEEP THE LOW LEVELS RATHER MOIST THE NEXT FEW DAYS. && .HYDROLOGY... OVERALL...FLOWS WILL CONTINUE TO GRADUALLY LOWER CLOSER TO SEASONAL NORMAL LEVELS OVER THE NEXT 5 DAYS. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH EARLY NEXT WEEK...HOWEVER WIDESPREAD RAINFALL IS NOT ANTICIPATED AT THIS TIME...AND NOT ALL LOCATIONS WILL RECEIVE THE RAINFALL. AS THE AIR MASS GETS MORE HUMID...SLOW MOVING THUNDERSTORMS COULD PRODUCE A QUICK INCH OR SO OF RAINFALL WITH HIGHER THAN NORMAL PWAT VALUES OVER THE HSA. SOME POOR DRAINAGE FLOODING OF LOW LYING AREAS...AND PONDING OF WATER ON ROADWAYS WILL BE POSSIBLE ANY DAY. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...BGM NEAR TERM...BGM SHORT TERM...BGM LONG TERM...HWJIV AVIATION...FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS MIAMI FL
137 PM EDT SAT JUN 22 2013 .AVIATION...RADAR SHOWS QUITE A BIT OF SHOWER ACTIVITY OVER THE NW BAHAMAS AT THIS TIME. THERE HAS BEEN A FEW TSTORMS AS WELL. AS THE TROUGH ASSOCIATED WITH THIS ACTIVITY MOVES WEST, WE EXPECT SHOWERS TO MOVE INTO SE FLORIDA TONIGHT, ESPECIALLY AFTER MIDNIGHT. A FEW THUNDERSTORMS WILL BE POSSIBLE AS WELL AS IT WILL BE SUFFICIENTLY UNSTABLE ALONG WITH PWATS INCREASING TO AROUND 2 INCHES. GIVEN THESE FORECASTED TRENDS, HAVE ADDED VCTS TO ALL EAST COAST TAF SITES BEGINNING AFTER MIDNIGHT AND CONTINUING THROUGH SUNDAY. FOR KAPF, ACTIVITY IS EXPECTED TO REMAIN EAST OF THE TERMINAL UNTIL AFTER ABOUT NOON ON SUNDAY, SO HELD OFF VCTS THERE UNTIL 16Z SUNDAY. BRIEF IFR WILL BE POSSIBLE WHERE HEAVIER SHRA/TSRA OCCURS, THOUGH PREVAILING CONDITIONS ARE EXPECTED TO REMAIN VFR. THANKS FOR COLLABORATION CWSU MIAMI. /GREGORIA && .PREV DISCUSSION... /ISSUED 1044 AM EDT SAT JUN 22 2013/ UPDATE... FORECAST WAS UPDATED FOR THE SHORT TERM AND THE REMAINDER OF THE WEEKEND. LATEST GUIDANCE SUGGESTS THAT FOR TODAY MAINLY ISOLATED SHOWERS OR ISOLATED THUNDERSTORMS EXPECTED ACROSS THE ATLANTIC WATERS AND EASTERN HALF OF THE PENINSULA WHILE FOR THE WESTERN HALF THIS AFTERNOON MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED. THE FORECAST WAS ALSO UPDATED TO REFLECT A CHANCE OF CONVECTION TONIGHT ACROSS THE ATLANTIC WATERS AND THE EASTERN THIRD OF THE PENINSULA AS A LOW LEVEL TROUGH CONTINUES TO MOVE WESTWARD ACROSS THE NORTHWEST BAHAMAS AND INTO THE LOCAL ATLANTIC WATERS. THE LOW LEVEL TROUGH IS FORECAST TO REMAIN MOVING WESTWARD ACROSS THE REGION TONIGHT THROUGH SUNDAY WITH A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THAT PERIOD. 60 PREV DISCUSSION... /ISSUED 648 AM EDT SAT JUN 22 2013/ AVIATION... QUIET WEATHER IS EXPECTED FOR THE TAF PERIOD WITH VFR CONDITIONS PREVAILING. THERE IS SOME TROPICAL MOISTURE TRYING TO MAKE ITS WAY INTO SOUTH FLORIDA, BUT IS HAVING TROUBLE DUE TO THE DRY AIR IN PLACE IN THE UPPER LEVELS. THERE IS STILL A SLIGHT CHANCE OF A SHOWER OR A THUNDERSTORM TODAY, BUT TOO UNCERTAIN TO MAKE ANY REFERENCE IN THE TAFS AT THIS TIME. PREV DISCUSSION... /ISSUED 256 AM EDT SAT JUN 22 2013/ SHORT TERM (TODAY THROUGH MONDAY)... DEEP LAYER RIDGE IS BEGINNING TO SHIFT NORTH AND THE 00Z MFL SOUNDING WAS SHOWING A DEEP EASTERLY FLOW AT 5 TO 10 KNOTS. THE TROPICAL WAVE THAT WAS PRODUCING NUMEROUS SHOWERS AND SOME THUNDERSTORMS A FEW DAYS AGO HAS BEEN FIGHTING SOME DRY AIR THAT SURROUNDS IT AND HAS NOW MOVED INTO THE CENTRAL CARIBBEAN LOSING MOST OF ITS CONVECTION. THE NORTHERN PORTION OF THE WAVE HAS BECOME A TROUGH OVER THE CENTRAL BAHAMAS AND HAS SCATTERED SHOWERS AND FEW THUNDERSTORMS ASSOCIATED WITH IT. THE TROUGH HAS SLOWED ITS FORWARD MOVEMENT AND MUCH DRIER AIR ALOFT IS AHEAD OF IT ACROSS THE WESTERN BAHAMAS AND SOUTH FLORIDA. IN FACT, THE SOUNDING LAST EVENING SHOWED THE PWAT HAD LOWERED TO 1.13 INCHES WHICH IS BELOW THE 25TH PERCENTILE FOR MID-LATE JUNE AND THERE WERE ONLY A FEW STORMS LATE YESTERDAY AS A RESULT OF THIS DRY AIR INTRUSION. DUE TO THE FACT THE ACTUAL WAVE WILL NOW REMAIN WELL TO OUR SOUTH AND THE TROUGH AXIS HAS SLOWED, THE HRRR IS SHOWING VIRTUALLY NO ACTION ALONG THE EAST COAST TODAY AND WITH THE DEEP EAST TO WEST STEERING FLOW DEPICTS SHOWERS AND STORMS DEVELOPING WELL INLAND AFTER 18Z AND THEN INCREASING AS THEY MOVE TOWARDS THE COLLIER COUNTY COAST AND THE LAKE REGION. THEREFORE, WILL LOWER THE POPS TO A SILENT 10 PERCENT OVER THE EAST METRO REGION AND TREND UP TO LOW END SCATTERED FARTHER INLAND. ALL OF THE GLOBAL MODELS ARE IN GOOD AGREEMENT WITH THIS SCENARIO AND ALSO INCREASE MOISTURE ON SUNDAY AS THE TROUGH AXIS APPROACHES. THE MOISTURE WILL STILL BE AROUND ON MONDAY BUT MODEL FORECAST SOUNDINGS ONLY SHOW AN INCREASE IN PWAT TO NEAR AVERAGE FOR THIS TIME OF YEAR SO SIGNIFICANT RAINFALL IS NOT ANTICIPATED. LONG TERM (MONDAY NIGHT THROUGH FRIDAY)... THE DEEP LAYER RIDGE WILL BECOME NEARLY STATIONARY ACROSS NORTH FLORIDA FOR MUCH OF THE UPCOMING WEEK SO THE BEST CHANCES FOR RAIN WILL BE DURING THE LATE NIGHT AND EARLY MORNING ALONG THE EAST COAST AND IN THE AFTERNOON TO EARLY EVENING FOR THE INTERIOR AND SOUTHWEST COAST. MOISTURE INCREASE WILL AGAIN NOT BE PLENTIFUL SO ONLY ISOLATED AREAS OF HEAVIER RAIN CAN BE EXPECTED MAINLY WHERE THE AFTERNOON THUNDERSTORMS CAN DEVELOP. MARINE... WIND SPEEDS WILL FLUCTUATE THROUGH THE PERIOD BUT REMAIN IN AN EAST TO SOUTHEAST DIRECTION SO SEAS WILL BE AT 4 FEET OR LESS. FIRE WEATHER... NO PROBLEMS OR CONCERNS WITH AMPLE LOW LEVEL MOISTURE REMAINING IN PLACE. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 89 78 88 78 / 20 30 40 20 FORT LAUDERDALE 88 79 88 80 / 20 30 40 20 MIAMI 89 78 88 79 / 20 30 40 20 NAPLES 92 74 92 75 / 40 30 50 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MIAMI FL
1044 AM EDT SAT JUN 22 2013 .UPDATE... FORECAST WAS UPDATED FOR THE SHORT TERM AND THE REMAINDER OF THE WEEKEND. LATEST GUIDANCE SUGGESTS THAT FOR TODAY MAINLY ISOLATED SHOWERS OR ISOLATED THUNDERSTORMS EXPECTED ACROSS THE ATLANTIC WATERS AND EASTERN HALF OF THE PENINSULA WHILE FOR THE WESTERN HALF THIS AFTERNOON MORE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED. THE FORECAST WAS ALSO UPDATED TO REFLECT A CHANCE OF CONVECTION TONIGHT ACROSS THE ATLANTIC WATERS AND THE EASTERN THIRD OF THE PENINSULA AS A LOW LEVEL TROUGH CONTINUES TO MOVE WESTWARD ACROSS THE NORTHWEST BAHAMAS AND INTO THE LOCAL ATLANTIC WATERS. THE LOW LEVEL TROUGH IS FORECAST TO REMAIN MOVING WESTWARD ACROSS THE REGION TONIGHT THROUGH SUNDAY WITH A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THAT PERIOD. 60 && .PREV DISCUSSION... /ISSUED 648 AM EDT SAT JUN 22 2013/ AVIATION... QUIET WEATHER IS EXPECTED FOR THE TAF PERIOD WITH VFR CONDITIONS PREVAILING. THERE IS SOME TROPICAL MOISTURE TRYING TO MAKE ITS WAY INTO SOUTH FLORIDA, BUT IS HAVING TROUBLE DUE TO THE DRY AIR IN PLACE IN THE UPPER LEVELS. THERE IS STILL A SLIGHT CHANCE OF A SHOWER OR A THUNDERSTORM TODAY, BUT TOO UNCERTAIN TO MAKE ANY REFERENCE IN THE TAFS AT THIS TIME. PREV DISCUSSION... /ISSUED 256 AM EDT SAT JUN 22 2013/ SHORT TERM (TODAY THROUGH MONDAY)... DEEP LAYER RIDGE IS BEGINNING TO SHIFT NORTH AND THE 00Z MFL SOUNDING WAS SHOWING A DEEP EASTERLY FLOW AT 5 TO 10 KNOTS. THE TROPICAL WAVE THAT WAS PRODUCING NUMEROUS SHOWERS AND SOME THUNDERSTORMS A FEW DAYS AGO HAS BEEN FIGHTING SOME DRY AIR THAT SURROUNDS IT AND HAS NOW MOVED INTO THE CENTRAL CARIBBEAN LOSING MOST OF ITS CONVECTION. THE NORTHERN PORTION OF THE WAVE HAS BECOME A TROUGH OVER THE CENTRAL BAHAMAS AND HAS SCATTERED SHOWERS AND FEW THUNDERSTORMS ASSOCIATED WITH IT. THE TROUGH HAS SLOWED ITS FORWARD MOVEMENT AND MUCH DRIER AIR ALOFT IS AHEAD OF IT ACROSS THE WESTERN BAHAMAS AND SOUTH FLORIDA. IN FACT, THE SOUNDING LAST EVENING SHOWED THE PWAT HAD LOWERED TO 1.13 INCHES WHICH IS BELOW THE 25TH PERCENTILE FOR MID-LATE JUNE AND THERE WERE ONLY A FEW STORMS LATE YESTERDAY AS A RESULT OF THIS DRY AIR INTRUSION. DUE TO THE FACT THE ACTUAL WAVE WILL NOW REMAIN WELL TO OUR SOUTH AND THE TROUGH AXIS HAS SLOWED, THE HRRR IS SHOWING VIRTUALLY NO ACTION ALONG THE EAST COAST TODAY AND WITH THE DEEP EAST TO WEST STEERING FLOW DEPICTS SHOWERS AND STORMS DEVELOPING WELL INLAND AFTER 18Z AND THEN INCREASING AS THEY MOVE TOWARDS THE COLLIER COUNTY COAST AND THE LAKE REGION. THEREFORE, WILL LOWER THE POPS TO A SILENT 10 PERCENT OVER THE EAST METRO REGION AND TREND UP TO LOW END SCATTERED FARTHER INLAND. ALL OF THE GLOBAL MODELS ARE IN GOOD AGREEMENT WITH THIS SCENARIO AND ALSO INCREASE MOISTURE ON SUNDAY AS THE TROUGH AXIS APPROACHES. THE MOISTURE WILL STILL BE AROUND ON MONDAY BUT MODEL FORECAST SOUNDINGS ONLY SHOW AN INCREASE IN PWAT TO NEAR AVERAGE FOR THIS TIME OF YEAR SO SIGNIFICANT RAINFALL IS NOT ANTICIPATED. LONG TERM (MONDAY NIGHT THROUGH FRIDAY)... THE DEEP LAYER RIDGE WILL BECOME NEARLY STATIONARY ACROSS NORTH FLORIDA FOR MUCH OF THE UPCOMING WEEK SO THE BEST CHANCES FOR RAIN WILL BE DURING THE LATE NIGHT AND EARLY MORNING ALONG THE EAST COAST AND IN THE AFTERNOON TO EARLY EVENING FOR THE INTERIOR AND SOUTHWEST COAST. MOISTURE INCREASE WILL AGAIN NOT BE PLENTIFUL SO ONLY ISOLATED AREAS OF HEAVIER RAIN CAN BE EXPECTED MAINLY WHERE THE AFTERNOON THUNDERSTORMS CAN DEVELOP. MARINE... WIND SPEEDS WILL FLUCTUATE THROUGH THE PERIOD BUT REMAIN IN AN EAST TO SOUTHEAST DIRECTION SO SEAS WILL BE AT 4 FEET OR LESS. FIRE WEATHER... NO PROBLEMS OR CONCERNS WITH AMPLE LOW LEVEL MOISTURE REMAINING IN PLACE. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 78 88 78 88 / 30 40 20 30 FORT LAUDERDALE 79 88 80 88 / 30 40 20 20 MIAMI 78 88 79 89 / 30 40 20 20 NAPLES 74 92 75 92 / 30 50 20 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...60/BD AVIATION/RADAR...57/DG
AREA FORECAST DISCUSSION
NWS MIAMI FL
648 AM EDT SAT JUN 22 2013 .AVIATION... QUIET WEATHER IS EXPECTED FOR THE TAF PERIOD WITH VFR CONDITIONS PREVAILING. THERE IS SOME TROPICAL MOISTURE TRYING TO MAKE ITS WAY INTO SOUTH FLORIDA, BUT IS HAVING TROUBLE DUE TO THE DRY AIR IN PLACE IN THE UPPER LEVELS. THERE IS STILL A SLIGHT CHANCE OF A SHOWER OR A THUNDERSTORM TODAY, BUT TOO UNCERTAIN TO MAKE ANY REFERENCE IN THE TAFS AT THIS TIME. && .PREV DISCUSSION... /ISSUED 256 AM EDT SAT JUN 22 2013/ SHORT TERM (TODAY THROUGH MONDAY)... DEEP LAYER RIDGE IS BEGINNING TO SHIFT NORTH AND THE 00Z MFL SOUNDING WAS SHOWING A DEEP EASTERLY FLOW AT 5 TO 10 KNOTS. THE TROPICAL WAVE THAT WAS PRODUCING NUMEROUS SHOWERS AND SOME THUNDERSTORMS A FEW DAYS AGO HAS BEEN FIGHTING SOME DRY AIR THAT SURROUNDS IT AND HAS NOW MOVED INTO THE CENTRAL CARIBBEAN LOSING MOST OF ITS CONVECTION. THE NORTHERN PORTION OF THE WAVE HAS BECOME A TROUGH OVER THE CENTRAL BAHAMAS AND HAS SCATTERED SHOWERS AND FEW THUNDERSTORMS ASSOCIATED WITH IT. THE TROUGH HAS SLOWED ITS FORWARD MOVEMENT AND MUCH DRIER AIR ALOFT IS AHEAD OF IT ACROSS THE WESTERN BAHAMAS AND SOUTH FLORIDA. IN FACT, THE SOUNDING LAST EVENING SHOWED THE PWAT HAD LOWERED TO 1.13 INCHES WHICH IS BELOW THE 25TH PERCENTILE FOR MID-LATE JUNE AND THERE WERE ONLY A FEW STORMS LATE YESTERDAY AS A RESULT OF THIS DRY AIR INTRUSION. DUE TO THE FACT THE ACTUAL WAVE WILL NOW REMAIN WELL TO OUR SOUTH AND THE TROUGH AXIS HAS SLOWED, THE HRRR IS SHOWING VIRTUALLY NO ACTION ALONG THE EAST COAST TODAY AND WITH THE DEEP EAST TO WEST STEERING FLOW DEPICTS SHOWERS AND STORMS DEVELOPING WELL INLAND AFTER 18Z AND THEN INCREASING AS THEY MOVE TOWARDS THE COLLIER COUNTY COAST AND THE LAKE REGION. THEREFORE, WILL LOWER THE POPS TO A SILENT 10 PERCENT OVER THE EAST METRO REGION AND TREND UP TO LOW END SCATTERED FARTHER INLAND. ALL OF THE GLOBAL MODELS ARE IN GOOD AGREEMENT WITH THIS SCENARIO AND ALSO INCREASE MOISTURE ON SUNDAY AS THE TROUGH AXIS APPROACHES. THE MOISTURE WILL STILL BE AROUND ON MONDAY BUT MODEL FORECAST SOUNDINGS ONLY SHOW AN INCREASE IN PWAT TO NEAR AVERAGE FOR THIS TIME OF YEAR SO SIGNIFICANT RAINFALL IS NOT ANTICIPATED. LONG TERM (MONDAY NIGHT THROUGH FRIDAY)... THE DEEP LAYER RIDGE WILL BECOME NEARLY STATIONARY ACROSS NORTH FLORIDA FOR MUCH OF THE UPCOMING WEEK SO THE BEST CHANCES FOR RAIN WILL BE DURING THE LATE NIGHT AND EARLY MORNING ALONG THE EAST COAST AND IN THE AFTERNOON TO EARLY EVENING FOR THE INTERIOR AND SOUTHWEST COAST. MOISTURE INCREASE WILL AGAIN NOT BE PLENTIFUL SO ONLY ISOLATED AREAS OF HEAVIER RAIN CAN BE EXPECTED MAINLY WHERE THE AFTERNOON THUNDERSTORMS CAN DEVELOP. MARINE... WIND SPEEDS WILL FLUCTUATE THROUGH THE PERIOD BUT REMAIN IN AN EAST TO SOUTHEAST DIRECTION SO SEAS WILL BE AT 4 FEET OR LESS. FIRE WEATHER... NO PROBLEMS OR CONCERNS WITH AMPLE LOW LEVEL MOISTURE REMAINING IN PLACE. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 89 78 88 78 / 10 20 20 20 FORT LAUDERDALE 88 79 88 80 / 10 20 20 20 MIAMI 89 78 88 79 / 10 20 20 20 NAPLES 92 74 92 75 / 30 20 20 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS MIAMI FL
256 AM EDT SAT JUN 22 2013 .SHORT TERM (TODAY THROUGH MONDAY)... DEEP LAYER RIDGE IS BEGINNING TO SHIFT NORTH AND THE 00Z MFL SOUNDING WAS SHOWING A DEEP EASTERLY FLOW AT 5 TO 10 KNOTS. THE TROPICAL WAVE THAT WAS PRODUCING NUMEROUS SHOWERS AND SOME THUNDERSTORMS A FEW DAYS AGO HAS BEEN FIGHTING SOME DRY AIR THAT SURROUNDS IT AND HAS NOW MOVED INTO THE CENTRAL CARIBBEAN LOSING MOST OF ITS CONVECTION. THE NORTHERN PORTION OF THE WAVE HAS BECOME A TROUGH OVER THE CENTRAL BAHAMAS AND HAS SCATTERED SHOWERS AND FEW THUNDERSTORMS ASSOCIATED WITH IT. THE TROUGH HAS SLOWED ITS FORWARD MOVEMENT AND MUCH DRIER AIR ALOFT IS AHEAD OF IT ACROSS THE WESTERN BAHAMAS AND SOUTH FLORIDA. IN FACT, THE SOUNDING LAST EVENING SHOWED THE PWAT HAD LOWERED TO 1.13 INCHES WHICH IS BELOW THE 25TH PERCENTILE FOR MID-LATE JUNE AND THERE WERE ONLY A FEW STORMS LATE YESTERDAY AS A RESULT OF THIS DRY AIR INTRUSION. DUE TO THE FACT THE ACTUAL WAVE WILL NOW REMAIN WELL TO OUR SOUTH AND THE TROUGH AXIS HAS SLOWED, THE HRRR IS SHOWING VIRTUALLY NO ACTION ALONG THE EAST COAST TODAY AND WITH THE DEEP EAST TO WEST STEERING FLOW DEPICTS SHOWERS AND STORMS DEVELOPING WELL INLAND AFTER 18Z AND THEN INCREASING AS THEY MOVE TOWARDS THE COLLIER COUNTY COAST AND THE LAKE REGION. THEREFORE, WILL LOWER THE POPS TO A SILENT 10 PERCENT OVER THE EAST METRO REGION AND TREND UP TO LOW END SCATTERED FARTHER INLAND. ALL OF THE GLOBAL MODELS ARE IN GOOD AGREEMENT WITH THIS SCENARIO AND ALSO INCREASE MOISTURE ON SUNDAY AS THE TROUGH AXIS APPROACHES. THE MOISTURE WILL STILL BE AROUND ON MONDAY BUT MODEL FORECAST SOUNDINGS ONLY SHOW AN INCREASE IN PWAT TO NEAR AVERAGE FOR THIS TIME OF YEAR SO SIGNIFICANT RAINFALL IS NOT ANTICIPATED. .LONG TERM (MONDAY NIGHT THROUGH FRIDAY)... THE DEEP LAYER RIDGE WILL BECOME NEARLY STATIONARY ACROSS NORTH FLORIDA FOR MUCH OF THE UPCOMING WEEK SO THE BEST CHANCES FOR RAIN WILL BE DURING THE LATE NIGHT AND EARLY MORNING ALONG THE EAST COAST AND IN THE AFTERNOON TO EARLY EVENING FOR THE INTERIOR AND SOUTHWEST COAST. MOISTURE INCREASE WILL AGAIN NOT BE PLENTIFUL SO ONLY ISOLATED AREAS OF HEAVIER RAIN CAN BE EXPECTED MAINLY WHERE THE AFTERNOON THUNDERSTORMS CAN DEVELOP. && .AVIATION... QUIET WEATHER IS EXPECTED FOR THE TAF PERIOD WITH VFR CONDITIONS PREVAILING. THERE IS SOME TROPICAL MOISTURE TRYING TO MAKE ITS WAY INTO SOUTH FLORIDA, BUT IS HAVING TROUBLE DUE TO THE DRY AIR IN PLACE IN THE UPPER LEVELS. THERE IS STILL A VERY SLIGHT CHANCE OF A SHOWER OR A THUNDERSTORM TODAY, BUT TOO UNCERTAIN TO MAKE ANY REFERENCE IN THE TAFS AT THIS TIME. && .MARINE... WIND SPEEDS WILL FLUCTUATE THROUGH THE PERIOD BUT REMAIN IN AN EAST TO SOUTHEAST DIRECTION SO SEAS WILL BE AT 4 FEET OR LESS. && .FIRE WEATHER... NO PROBLEMS OR CONCERNS WITH AMPLE LOW LEVEL MOISTURE REMAINING IN PLACE. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 89 78 88 78 / 10 20 20 20 FORT LAUDERDALE 88 79 88 80 / 10 20 20 20 MIAMI 89 78 88 79 / 10 20 20 20 NAPLES 92 74 92 75 / 30 20 20 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1024 PM CDT SUN JUN 23 2013 .DISCUSSION... 723 PM CDT MADE MINOR TWEAKS TO THE GOING FORECAST. CONVECTION HAS SUBSIDED WITH SHOWERS FROM CHICAGO THROUGH STREATOR. EXPECTING THE SHOWERS TO SLOWLY WEAKEN AND MOVE EASTWARD...PRODUCING UP TO AN ADDITIONAL TENTH OF AN INCH OF PRECIP. THE CONVECTIVE OUTFLOW COOLED AREAS BUT MOST PLACES HAVE REBOUNDED...SO ADJUSTED TEMPS TRENDS BUT DID NOT MAKE MAJOR CHANGES TO LOW TEMPS TONIGHT. AS FAR AS PRECIP CHANCES THROUGH THE REST OF THE NIGHT...MADE MINOR ADJUSTMENTS BUT THE OVERALL PICTURE REMAINS THE SAME. EXPECTING CONVECTION TO REFIRE IN THE FOUR CORNERS AREA OF NE/IA/MO/KS AND SPREAD ACROSS IA OVERNIGHT. STEERING FLOW WOULD DIRECT THE STORMS TO THE EAST WITH STORMS ENTERING AREAS ALONG AND WEST OF THE I-39 CORRIDOR AROUND/AFTER 09Z. HOWEVER CONFIDENCE IS LOW TO MEDIUM IN HOW CONVECTION WILL EVOLVE AND LOW IN TIMING. HEAVY RAIN IS A DEFINITE CONCERN...BUT DUE TO LOW CONFIDENCE IN THE CONVECTIVE EVOLUTION I WILL HOLD OFF ISSUING A FLASH FLOOD WATCH. LIGHTNING...GUSTY WINDS...AND SMALL HAIL ARE ALSO POSSIBLE...BUT THINKING SEVERE WEATHER WILL BE ISOLATED AT BEST DUE TO THE ELEVATED NATURE OF THE STORMS. JEE //PREV DISCUSSION... 304 PM CDT SHOWER/THUNDER CHANCES REMAIN THE BIGGEST FORECAST CHALLENGE FOLLOWED BY TEMPS WHICH MAY BE AFFECTED BY THE CONVECTION. AFTERNOON WATER VAPOR IMAGERY SHOWS ONE UPPER LEVEL LOW SPINNING OVER THE CENTRAL APPALACHIANS WHICH IS LOSING DEFINITION AS IS MOVES SLOWLY NORTHWARD. THE NEXT UPPER LOW IS SPINNING OVER THE SOUTHERN CANADIAN PRAIRIES WITH A TROUGH AXIS EXTENDING INTO THE DAKOTAS AND LIFTING NORTHEAST. THE UPPER FLOW IS LESS AMPLIFIED FURTHER SOUTH OF THE LOW ACROSS THE CENTRAL PLAINS BUT THERE ARE SEVERAL EMBEDDED WAVES THAT ARE TRANSLATING NORTHEAST AS WELL. THE NEXT UPPER LOW OF NOTE IS COMING ONSHORE OVER THE WEST COAST AND HELPING TO AMPLIFY A RIDGE OVER OREGON/WASHINGTON. ENERGY EMANATING FROM THIS TROUGH WILL BECOME A PLAYER IN OUR WEATHER LATER THIS WEEK. AT THE SURFACE...LOW PRESSURE IS POSITIONED OVER NORTHWEST MINNESOTA WITH WEAKER LOW PRESSURE SPREAD ACROSS THE PLAINS. A COOL FRONTAL BOUNDARY IS STRETCHED FROM THE MN LOW BUT HAS BECOME DIFFICULT TO IDENTIFY THANKS TO COLD POOLS FROM MORNING CONVECTION. THROUGH THIS EVENING...TOUGH FORECAST ONCE AGAIN IN TERMS OF CONVECTIVE POTENTIAL AND EVOLUTION THROUGH THE PERIOD. OUTFLOW BOUNDARY FROM EARLIER IOWA CONVECTION IS NOW PUSHING INTO THE WESTERN CWA TRIGGERING THUNDERSTORMS ALONG IT. A BETTER ORGANIZED COMPLEX OF STORMS HAS DEVELOPED FROM THE EARLIER CONVECTION BUT IS MOVING SOUTHEAST ACROSS NORTHERN MISSOURI INTO THE AXIS OF MUCH BETTER INSTABILITY AS WELL AS BETTER MID LEVEL MOISTURE ADVECTION. ADDITIONAL SCATTERED STORMS HAVE DEVELOPED OVER THE SOUTHERN CWA LIKELY IN BETTER CONJUNCTION WITH THE WEAKENING UPPER LOW OVER APPALACHIA. IN THE NEAR TERM...EXPECT THE OUTFLOW TO CONTINUE EASTWARD ACROSS THE CWA TRIGGERING SCATTERED STORMS THROUGH LATE AFTERNOON/EARLY EVENING. MESOANALYSIS SHOWS 2000+ J/KG OF MIXED LAYER CAPE OVER THE AREA SUPPORTING STRONG UPDRAFTS BUT DEEP LAYER SHEAR IS WEAK SO CORES SHOULD BE PRETTY PULSEY. LARGE HAIL AND LOCALLY HEAVY DOWNPOURS ARE THE MAIN CONCERN. GUSTY WINDS ARE ALSO POSSIBLE BUT RECENT AIRCRAFT SOUNDINGS FROM MDW DO NOT SHOW A TON OF DRY LOW LEVEL AIR AND RAP ANALYSIS OF DCAPE IS LOW AS WELL. WOULD EXPECT THAT THIS ACTIVITY WOULD WANE WITH SUNSET. REST OF TONIGHT AND MONDAY...ATTENTION TURNS TO ADDITIONAL CONVECTIVE POTENTIAL OVERNIGHT. WATER VAPOR SHOWS A WAVE OVER NE KS/NW MO WHICH APPEARS TO BE TURNING MORE EASTWARD IN THE LAST FEW SCANS. THIS IS LIKELY HELPING THE COMPLEX TAKING SHAPE OVER MO. SHORT TERM/HIGH RES GUIDANCE HAS BEEN ALL OVER THE PLACE WITH HOW CONVECTION EVOLVES THROUGH TONIGHT. THE MOIST SOUTHWESTERLY FLOW WILL CONTINUE ACROSS THE REGION TONIGHT AND THE EARLIER COLD FRONTAL BOUNDARY SEEMS TO BE DEVELOPING ONCE AGAIN ACROSS IOWA AS THE FLOW HAS SETTLED FROM EARLIER CONVECTION. THIS IS SUPPORTIVE OF NEW DEVELOPMENT TO THE WEST TONIGHT. THE OUTFLOW CURRENTLY WORKING INTO THE LOCAL AREA EXTENDS INTO WEST-CENTRAL ILLINOIS AND THERE ARE HINTS THAT THE SOUTHERN EXTENT OF IT AND LIKELY A BOUNDARY SET UP BY THE CURRENT COMPLEX MAY STALL OUT SOMEWHERE NOT FAR FROM THE SOUTHWESTERN CWA. IN ADDITION...THE KS/MO WAVE IS EXPECTED TO CROSS THIS SAME AREA TONIGHT WHICH IS ALSO EXPECTED TO BE IN AN AREA OF MID LEVEL WARM ADVECTION. THEREFORE IT IS POSSIBLE ROUNDS OF CONVECTION COULD DEVELOP TO THE SOUTHWEST OF THE AREA AND ROLL EASTWARD INTO THE SOUTHERN CWA OVERNIGHT. HAVE NOT MADE MUCH CHANGE TO OVERNIGHT POPS BUT DID INCREASE THEM SOMEWHAT OVER THE FAR SOUTH. AS FOR MONDAY...GUIDANCE REMAINS IN POOR AGREEMENT WITH TRACK OF POTENTIAL UPPER WAVES BUT WATER VAPOR DOES SHOW SOME SIGNS OF A WAVE COMING ACROSS THE FOUR CORNERS THIS AFTERNOON. THIS WOULD COME ACROSS THE REGION LATER MONDAY BUT IT IS NOT CLEAR IF IT WILL BE MORE FOCUSED TO THE NORTH OF THE AREA. WILL CONTINUE WITH MID CHANCE POPS WITH LATER IN THE DAY MORE FAVORED. PROVIDED THE LATER TIMING WORKS OUT THEN WE WILL HAVE A BETTER CHANCE TO WARM BUT THERE MAY BE CONVECTIVE DEBRIS AROUND SO WILL HOLD TEMPS INTO THE MID 80S FOR MOST AREAS. TUESDAY THROUGH SUNDAY...THE UPPER FLOW BECOMES LESS AMPLIFIED TUESDAY BUT WILL LIKELY STILL BE LITTERED WITH WAVES TRAVERSING IT. HOT AND HUMID AIR WILL STILL BE IN PLACE WITH PRECIPITABLE WATER VALUES HOVERING AROUND 1.75 INCHES. THESE FACTORS PROVIDE CONTINUED SUPPORT FOR THUNDERSTORM DEVELOPMENT BUT THERE IS NOT MUCH TO KEY IN ON FOR A COHERENT FORCING MECHANISM GIVEN THE LOW AMPLITUDE PATTERN. BY WEDNESDAY...THERE IS SOME AGREEMENT ON SURFACE LOW PRESSURE HAVING DEVELOPED ACROSS THE CANADIAN PRAIRIES WITH A TROUGH AXIS/FRONT EXTENDING INTO MINNESOTA AND IOWA...WITH A SECONDARY LOW POSSIBLY DEVELOPING ACROSS MINNESOTA. THE FRONT LOOKS TO CROSS THE AREA LATER WEDNESDAY BRINGING SHOWER AND STORM CHANCES WITH IT. UPPER RIDGING WILL BE BUILDING ACROSS THE WESTERN U.S. AND HIGH PLAINS WITH A WAVE ORIGINATING FROM THE TROUGH OFF THE WEST COAST OVERTOPPING THE RIDGE ACROSS THE CANADIAN ROCKIES AND DROPPING SOUTHEASTWARD INTO THE GREAT LAKES WHILE AMPLIFYING LATE IN THE WEEK. GFS AND ECMWF DIFFER ON HOW QUICKLY THIS OCCURS BUT THE SIGNAL HAS BEEN CONSISTENT OVERALL. THIS WILL BRING A SHIFT TO NORTHWESTERLY AT THE SURFACE AND ALOFT LATE IN THE WEEK AND NOTICEABLY COOLER TEMPERATURES BY SATURDAY OR SO. LOW POPS WILL CONTINUE WITH THE FLOW CONTINUING TO FAVOR WEAK SHORTWAVE PASSAGES. HIGH TEMPS WILL LIKELY HOVER AROUND 90 TUESDAY AND WEDNESDAY ASSUMING CONVECTION OR CONVECTIVE DEBRIS IS NOT AN ISSUE...WHICH WOULD SIGNIFICANTLY LOWER HIGHS IF IT IS. WITH THE PASSAGE OF THE SYSTEM LATER WEDNESDAY COOLER MID LEVEL AIR WILL FILTER IN KEEPING HIGHS BACK IN THE 80S WITH UPPER 70S POSSIBLE FRIDAY AND SATURDAY. MDB && .HYDROLOGY... 745 PM CDT THE CONVECTIVE ACTIVITY THIS EVENING PRODUCED ISOLATED AREAS OF 2+ INCHES OF RAIN AND A BAND OF 1+ INCHES OF RAIN ACROSS LA SALLE COUNTY. STILL CONSIDERED A FLASH FLOOD WATCH FOR THE WEST AND FAR SOUTHWEST CWA GIVEN THE RAINFALL OF THE PAST FEW DAYS. CONFIDENCE REMAINS LOW IN WHERE ORGANIZED CONVECTION WILL SET UP TONIGHT AND MONDAY SO WILL HOLD OFF UNTIL AREAS AND TIMING CAN BE BETTER DEFINED. JEE/MDB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * CHANCE OF SHRA/TSRA MONDAY MORNING AND AGAIN MONDAY AFTERNOON. * POSSIBLE GUSTY SOUTHWESTERLY WINDS MONDAY. CMS //DISCUSSION...UPDATED 00Z... THUNDERSTORMS HAVE HAVE SHOWN A RAPID DIMINISHING TREND OVER THE LAST HOUR AND EXPECT THIS TO CONTINUE WITH ONLY SHOWERS EXPECTED. AFTER THESE SHOWERS DIMINISH...DO EXPECT A DRY PERIOD FOR THE REMAINDER OF THE EVENING BEFORE CHANCES FOR SHOWERS/THUNDERSTORMS BEGIN TO INCREASE ONCE AGAIN EARLY MONDAY MORNING. SEVERAL CHANCES FOR SHOWERS AND THUNDERSTORMS DO APPEAR POSSIBLE THROUGHOUT THE DAY ON MONDAY...BUT WITH CONFIDENCE LOWER ON EXACT TIMING. ALTHOUGH...MONDAY AFTERNOON APPEARS AS IF IT COULD BE AN ACTIVE PERIOD. OUTSIDE OF THE THE PRECIP CHANCES THIS FORECAST PERIOD AND MAYBE SOME PATCHY FOG EARLY MONDAY MORNING...EXPECT VFR CONDITIONS WITH SOUTH/SOUTHWEST WINDS IN PLACE. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 03Z... * LOW REGARDING PRECIP POTENTIAL MONDAY MORNING...MEDIUM FOR MONDAY AFTERNOON. * MEDIUM FOR WIND SPEEDS/GUSTS THROUGH THE PERIOD. CMS //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH FRIDAY...PERIODIC CHANCES OF TSRA. SATURDAY...CHANCE OF SHRA. RODRIGUEZ && .MARINE... 420 PM CDT A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE WESTERN ATLANTIC SOUTHWESTWARD ACROSS THE SOUTHEASTERN U.S. AND THE NORTHERN GULF OF MEXICO. THIS HIGH WILL BE MOVING ONLY VERY SLOWLY SOUTHEASTWARD TONIGHT THROUGH THURSDAY. LOW PRESSURE NEAR LAKE WINNIPEG WILL BE MOVING SLOWLY EASTWARD ACROSS ONTARIO...REACHING NEAR SOUTHERN JAMES BAY BY TUESDAY MORNING. THEN...AN AREA OF LOW PRESSURE STRETCHING FROM THE SOUTHERN CANADIAN PRAIRIE SOUTH ACROSS THE PLAINS WILL MOVE NORTHEAST DURING TUESDAY AND WEDNESDAY. WITH HIGH PRESSURE SITUATED FAR TO THE SOUTH THROUGH SOUTHEAST OF THE LAKE AND LOW PRESSURE FROM FAR WEST THROUGH NORTHWEST TONIGHT INTO THURSDAY...MODERATE TO FRESH WINDS WILL PERSIST OUT OF THE SOUTH TO SOUTHWEST. THIS PERSISTENT FLOW WILL KEEP VERY MOIST AIR ACROSS THE WESTERN GREAT LAKES REGION. WHILE MOST OF THE FOG HAD DISSIPATED ON NORTHERN LAKE MICHIGAN...WITH THE MOIST AIR AND COOL LAKE WATER FOG IS EXPECTED TO REDEVELOP TONIGHT AND BECOME DENSE IN AREAS. THE CURRENT DENSE FOG ADVISORY FOR NORTHERN LAKE MICHIGAN WILL LIKELY NEED TO BE EXTENDED INTO TUESDAY AND POSSIBLY WEDNESDAY AS THERE WILL BE NO CHANGE IN AIRMASS UNTIL A COLD FRONT PUSHES ACROSS THE LAKE DURING LATER WEDNESDAY AND WEDNESDAY NIGHT...SHIFTING WINDS TO OUT OF THE WEST. A SECONDARY COLD FRONT WILL MOVE ACROSS THE LAKE AND SHIFT WINDS TO OUT OF THE NORTHWEST DURING LATER THURSDAY AND THURSDAY NIGHT. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 7 AM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
753 PM CDT SUN JUN 23 2013 .DISCUSSION... ISSUED 747 PM CDT SUN JUN 23 2013 DROPPED THE OVERNIGHT LOWS A COUPLE DEGREES FROM TODAYS PRECIP...WITH NOT TOO FAR TO GO FOR SOME LOCATIONS THANKS TO ONGOING PRECIP. SOME MINOR TWEAKS TO THE FORECAST IN REGARDS TO POPS BEFORE MIDNIGHT...REFLECTING THE EVOLUTION OF THE DYING PRECIP THAT IS OUT THERE NOW. HOWEVER...MODELS IN THE SHORT TERM STILL QUITE POLARIZED. WITH THAT IN MIND...AND A COUPLE OF DISCRETE CELLS IN NRN MO...KEEPING THE LIKELY POPS FOR AFTER MIDNIGHT IN THE NW. REMAIN IN ACTIVE AND ERRATIC PATTERN THROUGH THE OVERNIGHT. MANY OUTFLOW BOUNDARIES AND INTERACTIONS IN A RELATIVELY STABLE AIRMASS...ANY CONCERN FOR SEVERE WEATHER AT THIS POINT IS FOCUSED MAINLY ON FLOODING POTENTIAL IN THE SOUTHEAST. UPDATE OUT MOMENTARILY. HJS && .AVIATION... ISSUED 658 PM CDT SUN JUN 23 2013 ADJUSTING FORECAST IN THE SHORT TERM TO HANDLE THE SLOWLY DWINDLING CONVECTION. PRECIP FALLING APART A BIT QUICKER THAN PREV MODEL RUNS ANTICIPATED...AND AS A RESULT HAVE LEFT TOO MUCH MENTION OF PRECIP IN MOST OF THE TAFS. CONCERN FOR PRECIP CONTINUES THROUGH TOMORROW THOUGH MODELS ARE ALL OVER THE PLACE. MOST FAITH IN HRRR FOR NOW...WHICH HAS A MORE SCT SIGNATURE. WILL AWAIT NEXT RUN BEFORE CALLING PRECIP AND TIMING FOR TOMORROW. HJS && .PREV DISCUSSION... ISSUED 300 PM CDT SUN JUN 23 2013 TWO ONGOING COMPLEXES OF STORMS WILL HIGHLIGHT THE SHORT TERM...A LINE OF STORMS IN THE NW AND A CLUSTER OF HEAVY RAIN IN THE SE. HEAT AND PERIODIC STORM CHANCES WILL CONTINUE FOR MUCH OF THE WEEK UNTIL A MORE SIGNIFICANT UPPER WAVE MAKES PROGRESS FROM CANADA ACROSS THE GREAT LAKES AND CHANGES OUR UPPER FLOW OUT OF THE NORTHWEST...AS A TROUGH DEVELOPS IN THE EAST AND A RIDGE TO OUR WEST. SHORT TERM...TONIGHT THROUGH THURSDAY. THE HEAVY RAIN COMPLEX IN THE SOUTHEAST ASSOCIATED WITH A MESO- VORTEX APPEARS TO BE WEAKENING...ALBEIT WITH STEADY RAINS CONTINUING ACROSS A WATER-LOGGED AREA. SEVERAL FLASH FLOOD WARNINGS REMAIN IN EFFECT INTO THIS EVENING FOR THAT AREA...WHERE 3-5 INCHES OF RAIN HAS FALLEN. SPC MESO-ANALYSIS GRAPHICS SHOW INSTABILITY PARAMETERS IN THE SE AREA APPEAR TO BE STABILIZING...WHILE BETTER SUPPORT FOR STRONG STORMS EXISTS AHEAD OF THE LINE OF STORMS ENTERING OUR NW COUNTIES. ML-CAPE VALUES OF 3000-3500 J/KG SHOULD BE ENOUGH TO KEEP THEM ADVANCING INTO OUR AREA. PRECIPITABLE WATER VALUES AROUND 1.7" AND VERY WEAK WINDS IN THE MID-UPPER LEVELS LEND SUPPORT FOR HEAVY RAIN FROM THOSE STORMS INTO THIS EVENING. THEY SHOULD MAINTAIN BETTER FORWARD PROGRESS BASED ON THE MOVEMENT OF THE UPPER SHORTWAVE ON WATER VAPOR SATELLITE. THE TRACK OF THE LINE OF STORMS SHOULD EVENTUALLY BEGIN TO CURL TO THE SOUTHEAST. WE TRIED TO MATCH POPS TO CURRENT CONDITIONS AND PROGRESS THEM THROUGH THE EVENING AND OVERNIGHT UTILIZING SATELLITE AND RADAR TRENDS. MODELS HAVE GENERALLY BEEN ALL OVER THE PLACE WITH CONVECTIVE SOLUTIONS...SO THEY HAVE NOT BEEN MUCH HELP TO FORECAST DETAILS IN THE NEAR TERM. WE USED GENERAL MODEL TRENDS WITH THE PROGRESS OF THE OVERALL PATTERN THROUGH MID WEEK. WE EXPECT TO REMAIN IN THE WARM SECTOR THROUGH THURSDAY...A GRADUAL BUILDING OF THE UPPER LEVEL RIDGE INTO CENTRAL IL FOR TUESDAY AND TUESDAY NIGHT...WHICH MAY HELP SUPPRESS STORMS FOR AROUND 24 HOURS. WE KEPT SLIGHT CHANCE POPS TUE-TUE NIGHT AS A RESULT. UPPER TROUGHING REDEVELOPS FOR WEDNESDAY AS A SURFACE TROUGH PROGRESSES ACROSS IL WED NIGHT INTO THURSDAY. THAT WILL INITIALLY ESTABLISH NORTHWEST FLOW ALOFT...AND BEGIN OUR AIRMASS CHANGE THAT IS PROJECTED TO FINALLY BECOME ESTABLISHED NEXT WEEKEND. IN THE MEAN TIME...TUESDAY AND WEDNESDAY LOOK TO BE OUR HOTTEST DAYS OF THIS WEEK...AS HEAT INDEX READINGS CLIMB INTO THE 100-105 RANGE EACH AFTERNOON AND EARLY EVENING...OUTSIDE OF ANY STORM COMPLEXES. WE INCREASED POPS INTO THE CHANCE CATEGORY FOR WED AFTERNOON AND CONTINUED CHANCE POPS WED NIGHT...CONFINING THEM TO THE EASTERN AREAS ON THURSDAY AS THE TROUGH PUSHES EAST INTO INDIANA. WE MAY SEE ANOTHER ROUND OF STRONG STORMS WITH HEAVY RAIN ALONG THAT FRONT...AS PLENTY OF MOISTURE POOLING IS PROJECTED TO OCCUR AHEAD OF THE SYSTEM. LONG TERM...FRIDAY THROUGH SUNDAY. A COOLING TREND SHOULD ALREADY BE NOTICEABLE ON FRIDAY AS SURFACE WINDS TURN OUT OF THE NORTHWEST AND DEWPOINTS BEGIN TO DROP FROM THE 70S INTO THE 60S. WE HELD ONTO A SLIGHT CHANCE OF SHOWERS AND STORMS ON FRIDAY...AS THE UPPER TROUGH AXIS DEPARTS EASTWARD AND A 500MB SHORTWAVE ROTATES THROUGH THE BACK SIDE OF THE TROUGH. THE DAY SHOULD BE DOMINATED BY CLOUDS HELPING TO KEEP HIGHS IN THE MID 80S. DRY CONDITIONS SHOULD RETURN FRI NIGHT...WITH A FEW INSTABILITY SHOWERS POSSIBLE IN THE EAST ON SATURDAY AS THE COLD POOL ALOFT PASSES OVER THE AREA. HIGHS ON SATURDAY AND SUNDAY SHOULD TOP OUT IN THE LOWER 80S WITH OVERNIGHT LOWS IN THE LOW 60S...WITH MUCH LESS HUMIDITY IN THE AIR. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
746 PM CDT SUN JUN 23 2013 .DISCUSSION... 723 PM CDT MADE MINOR TWEAKS TO THE GOING FORECAST. CONVECTION HAS SUBSIDED WITH SHOWERS FROM CHICAGO THROUGH STREATOR. EXPECTING THE SHOWERS TO SLOWLY WEAKEN AND MOVE EASTWARD...PRODUCING UP TO AN ADDITIONAL TENTH OF AN INCH OF PRECIP. THE CONVECTIVE OUTFLOW COOLED AREAS BUT MOST PLACES HAVE REBOUNDED...SO ADJUSTED TEMPS TRENDS BUT DID NOT MAKE MAJOR CHANGES TO LOW TEMPS TONIGHT. AS FAR AS PRECIP CHANCES THROUGH THE REST OF THE NIGHT...MADE MINOR ADJUSTMENTS BUT THE OVERALL PICTURE REMAINS THE SAME. EXPECTING CONVECTION TO REFIRE IN THE FOUR CORNERS AREA OF NE/IA/MO/KS AND SPREAD ACROSS IA OVERNIGHT. STEERING FLOW WOULD DIRECT THE STORMS TO THE EAST WITH STORMS ENTERING AREAS ALONG AND WEST OF THE I-39 CORRIDOR AROUND/AFTER 09Z. HOWEVER CONFIDENCE IS LOW TO MEDIUM IN HOW CONVECTION WILL EVOLVE AND LOW IN TIMING. HEAVY RAIN IS A DEFINITE CONCERN...BUT DUE TO LOW CONFIDENCE IN THE CONVECTIVE EVOLUTION I WILL HOLD OFF ISSUING A FLASH FLOOD WATCH. LIGHTNING...GUSTY WINDS...AND SMALL HAIL ARE ALSO POSSIBLE...BUT THINKING SEVERE WEATHER WILL BE ISOLATED AT BEST DUE TO THE ELEVATED NATURE OF THE STORMS. JEE && .PREV DISCUSSION... 304 PM CDT SHOWER/THUNDER CHANCES REMAIN THE BIGGEST FORECAST CHALLENGE FOLLOWED BY TEMPS WHICH MAY BE AFFECTED BY THE CONVECTION. AFTERNOON WATER VAPOR IMAGERY SHOWS ONE UPPER LEVEL LOW SPINNING OVER THE CENTRAL APPALACHIANS WHICH IS LOSING DEFINITION AS IS MOVES SLOWLY NORTHWARD. THE NEXT UPPER LOW IS SPINNING OVER THE SOUTHERN CANADIAN PRAIRIES WITH A TROUGH AXIS EXTENDING INTO THE DAKOTAS AND LIFTING NORTHEAST. THE UPPER FLOW IS LESS AMPLIFIED FURTHER SOUTH OF THE LOW ACROSS THE CENTRAL PLAINS BUT THERE ARE SEVERAL EMBEDDED WAVES THAT ARE TRANSLATING NORTHEAST AS WELL. THE NEXT UPPER LOW OF NOTE IS COMING ONSHORE OVER THE WEST COAST AND HELPING TO AMPLIFY A RIDGE OVER OREGON/WASHINGTON. ENERGY EMANATING FROM THIS TROUGH WILL BECOME A PLAYER IN OUR WEATHER LATER THIS WEEK. AT THE SURFACE...LOW PRESSURE IS POSITIONED OVER NORTHWEST MINNESOTA WITH WEAKER LOW PRESSURE SPREAD ACROSS THE PLAINS. A COOL FRONTAL BOUNDARY IS STRETCHED FROM THE MN LOW BUT HAS BECOME DIFFICULT TO IDENTIFY THANKS TO COLD POOLS FROM MORNING CONVECTION. THROUGH THIS EVENING...TOUGH FORECAST ONCE AGAIN IN TERMS OF CONVECTIVE POTENTIAL AND EVOLUTION THROUGH THE PERIOD. OUTFLOW BOUNDARY FROM EARLIER IOWA CONVECTION IS NOW PUSHING INTO THE WESTERN CWA TRIGGERING THUNDERSTORMS ALONG IT. A BETTER ORGANIZED COMPLEX OF STORMS HAS DEVELOPED FROM THE EARLIER CONVECTION BUT IS MOVING SOUTHEAST ACROSS NORTHERN MISSOURI INTO THE AXIS OF MUCH BETTER INSTABILITY AS WELL AS BETTER MID LEVEL MOISTURE ADVECTION. ADDITIONAL SCATTERED STORMS HAVE DEVELOPED OVER THE SOUTHERN CWA LIKELY IN BETTER CONJUNCTION WITH THE WEAKENING UPPER LOW OVER APPALACHIA. IN THE NEAR TERM...EXPECT THE OUTFLOW TO CONTINUE EASTWARD ACROSS THE CWA TRIGGERING SCATTERED STORMS THROUGH LATE AFTERNOON/EARLY EVENING. MESOANALYSIS SHOWS 2000+ J/KG OF MIXED LAYER CAPE OVER THE AREA SUPPORTING STRONG UPDRAFTS BUT DEEP LAYER SHEAR IS WEAK SO CORES SHOULD BE PRETTY PULSEY. LARGE HAIL AND LOCALLY HEAVY DOWNPOURS ARE THE MAIN CONCERN. GUSTY WINDS ARE ALSO POSSIBLE BUT RECENT AIRCRAFT SOUNDINGS FROM MDW DO NOT SHOW A TON OF DRY LOW LEVEL AIR AND RAP ANALYSIS OF DCAPE IS LOW AS WELL. WOULD EXPECT THAT THIS ACTIVITY WOULD WANE WITH SUNSET. REST OF TONIGHT AND MONDAY...ATTENTION TURNS TO ADDITIONAL CONVECTIVE POTENTIAL OVERNIGHT. WATER VAPOR SHOWS A WAVE OVER NE KS/NW MO WHICH APPEARS TO BE TURNING MORE EASTWARD IN THE LAST FEW SCANS. THIS IS LIKELY HELPING THE COMPLEX TAKING SHAPE OVER MO. SHORT TERM/HIGH RES GUIDANCE HAS BEEN ALL OVER THE PLACE WITH HOW CONVECTION EVOLVES THROUGH TONIGHT. THE MOIST SOUTHWESTERLY FLOW WILL CONTINUE ACROSS THE REGION TONIGHT AND THE EARLIER COLD FRONTAL BOUNDARY SEEMS TO BE DEVELOPING ONCE AGAIN ACROSS IOWA AS THE FLOW HAS SETTLED FROM EARLIER CONVECTION. THIS IS SUPPORTIVE OF NEW DEVELOPMENT TO THE WEST TONIGHT. THE OUTFLOW CURRENTLY WORKING INTO THE LOCAL AREA EXTENDS INTO WEST-CENTRAL ILLINOIS AND THERE ARE HINTS THAT THE SOUTHERN EXTENT OF IT AND LIKELY A BOUNDARY SET UP BY THE CURRENT COMPLEX MAY STALL OUT SOMEWHERE NOT FAR FROM THE SOUTHWESTERN CWA. IN ADDITION...THE KS/MO WAVE IS EXPECTED TO CROSS THIS SAME AREA TONIGHT WHICH IS ALSO EXPECTED TO BE IN AN AREA OF MID LEVEL WARM ADVECTION. THEREFORE IT IS POSSIBLE ROUNDS OF CONVECTION COULD DEVELOP TO THE SOUTHWEST OF THE AREA AND ROLL EASTWARD INTO THE SOUTHERN CWA OVERNIGHT. HAVE NOT MADE MUCH CHANGE TO OVERNIGHT POPS BUT DID INCREASE THEM SOMEWHAT OVER THE FAR SOUTH. AS FOR MONDAY...GUIDANCE REMAINS IN POOR AGREEMENT WITH TRACK OF POTENTIAL UPPER WAVES BUT WATER VAPOR DOES SHOW SOME SIGNS OF A WAVE COMING ACROSS THE FOUR CORNERS THIS AFTERNOON. THIS WOULD COME ACROSS THE REGION LATER MONDAY BUT IT IS NOT CLEAR IF IT WILL BE MORE FOCUSED TO THE NORTH OF THE AREA. WILL CONTINUE WITH MID CHANCE POPS WITH LATER IN THE DAY MORE FAVORED. PROVIDED THE LATER TIMING WORKS OUT THEN WE WILL HAVE A BETTER CHANCE TO WARM BUT THERE MAY BE CONVECTIVE DEBRIS AROUND SO WILL HOLD TEMPS INTO THE MID 80S FOR MOST AREAS. TUESDAY THROUGH SUNDAY...THE UPPER FLOW BECOMES LESS AMPLIFIED TUESDAY BUT WILL LIKELY STILL BE LITTERED WITH WAVES TRAVERSING IT. HOT AND HUMID AIR WILL STILL BE IN PLACE WITH PRECIPITABLE WATER VALUES HOVERING AROUND 1.75 INCHES. THESE FACTORS PROVIDE CONTINUED SUPPORT FOR THUNDERSTORM DEVELOPMENT BUT THERE IS NOT MUCH TO KEY IN ON FOR A COHERENT FORCING MECHANISM GIVEN THE LOW AMPLITUDE PATTERN. BY WEDNESDAY...THERE IS SOME AGREEMENT ON SURFACE LOW PRESSURE HAVING DEVELOPED ACROSS THE CANADIAN PRAIRIES WITH A TROUGH AXIS/FRONT EXTENDING INTO MINNESOTA AND IOWA...WITH A SECONDARY LOW POSSIBLY DEVELOPING ACROSS MINNESOTA. THE FRONT LOOKS TO CROSS THE AREA LATER WEDNESDAY BRINGING SHOWER AND STORM CHANCES WITH IT. UPPER RIDGING WILL BE BUILDING ACROSS THE WESTERN U.S. AND HIGH PLAINS WITH A WAVE ORIGINATING FROM THE TROUGH OFF THE WEST COAST OVERTOPPING THE RIDGE ACROSS THE CANADIAN ROCKIES AND DROPPING SOUTHEASTWARD INTO THE GREAT LAKES WHILE AMPLIFYING LATE IN THE WEEK. GFS AND ECMWF DIFFER ON HOW QUICKLY THIS OCCURS BUT THE SIGNAL HAS BEEN CONSISTENT OVERALL. THIS WILL BRING A SHIFT TO NORTHWESTERLY AT THE SURFACE AND ALOFT LATE IN THE WEEK AND NOTICEABLY COOLER TEMPERATURES BY SATURDAY OR SO. LOW POPS WILL CONTINUE WITH THE FLOW CONTINUING TO FAVOR WEAK SHORTWAVE PASSAGES. HIGH TEMPS WILL LIKELY HOVER AROUND 90 TUESDAY AND WEDNESDAY ASSUMING CONVECTION OR CONVECTIVE DEBRIS IS NOT AN ISSUE...WHICH WOULD SIGNIFICANTLY LOWER HIGHS IF IT IS. WITH THE PASSAGE OF THE SYSTEM LATER WEDNESDAY COOLER MID LEVEL AIR WILL FILTER IN KEEPING HIGHS BACK IN THE 80S WITH UPPER 70S POSSIBLE FRIDAY AND SATURDAY. MDB && .HYDROLOGY...745 PM CDT THE CONVECTIVE ACTIVITY THIS EVENING PRODUCED ISOLATED AREAS OF 2+ INCHES OF RAIN AND A BAND OF 1+ INCHES OF RAIN ACROSS LA SALLE COUNTY. STILL CONSIDERED A FLASH FLOOD WATCH FOR THE WEST AND FAR SOUTHWEST CWA GIVEN THE RAINFALL OF THE PAST FEW DAYS. CONFIDENCE REMAINS LOW IN WHERE ORGANIZED CONVECTION WILL SET UP TONIGHT AND MONDAY SO WILL HOLD OFF UNTIL AREAS AND TIMING CAN BE BETTER DEFINED. JEE/MDB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * SHOWERS WILL LINGER ACROSS THE TERMINALS OVER THE NEXT COUPLE OF HOURS BEFORE DRIER CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE EVENING. * POSSIBILITY FOR A CONTINUED ACTIVE PERIOD WITH SEVERAL CHANCES FOR SHOWERS/THUNDERSTORMS TO MOVE ACROSS THE TERMINALS EARLY MONDAY MORNING THROUGH MONDAY EVENING. * SOUTHERLY WINDS AROUND 10KT EXPECTED THIS EVENING. RODRIGUEZ //DISCUSSION...UPDATED 00Z... THUNDERSTORMS HAVE HAVE SHOWN A RAPID DIMINISHING TREND OVER THE LAST HOUR AND EXPECT THIS TO CONTINUE WITH ONLY SHOWERS EXPECTED. AFTER THESE SHOWERS DIMINISH...DO EXPECT A DRY PERIOD FOR THE REMAINDER OF THE EVENING BEFORE CHANCES FOR SHOWERS/THUNDERSTORMS BEGIN TO INCREASE ONCE AGAIN EARLY MONDAY MORNING. SEVERAL CHANCES FOR SHOWERS AND THUNDERSTORMS DO APPEAR POSSIBLE THROUGHOUT THE DAY ON MONDAY...BUT WITH CONFIDENCE LOWER ON EXACT TIMING. ALTHOUGH...MONDAY AFTERNOON APPEARS AS IF IT COULD BE AN ACTIVE PERIOD. OUTSIDE OF THE THE PRECIP CHANCES THIS FORECAST PERIOD AND MAYBE SOME PATCHY FOG EARLY MONDAY MORNING...EXPECT VFR CONDITIONS WITH SOUTH/SOUTHWEST WINDS IN PLACE. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 00Z... * HIGH CONFIDENCE WITH SHOWER TRENDS OVER THE NEXT COUPLE OF HOURS. * LOW MEDIUM CONFIDENCE WITH PRECIP TRENDS EARLY MONDAY MORNING THROUGH MONDAY EVENING. * MEDIUM CONFIDENCE WITH WIND SPEED AND DIRECTION THIS EVENING. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH FRIDAY...PERIODIC CHANCES OF TSRA. SATURDAY...CHANCE OF SHRA. RODRIGUEZ && .MARINE... 420 PM CDT A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE WESTERN ATLANTIC SOUTHWESTWARD ACROSS THE SOUTHEASTERN U.S. AND THE NORTHERN GULF OF MEXICO. THIS HIGH WILL BE MOVING ONLY VERY SLOWLY SOUTHEASTWARD TONIGHT THROUGH THURSDAY. LOW PRESSURE NEAR LAKE WINNIPEG WILL BE MOVING SLOWLY EASTWARD ACROSS ONTARIO...REACHING NEAR SOUTHERN JAMES BAY BY TUESDAY MORNING. THEN...AN AREA OF LOW PRESSURE STRETCHING FROM THE SOUTHERN CANADIAN PRAIRIE SOUTH ACROSS THE PLAINS WILL MOVE NORTHEAST DURING TUESDAY AND WEDNESDAY. WITH HIGH PRESSURE SITUATED FAR TO THE SOUTH THROUGH SOUTHEAST OF THE LAKE AND LOW PRESSURE FROM FAR WEST THROUGH NORTHWEST TONIGHT INTO THURSDAY...MODERATE TO FRESH WINDS WILL PERSIST OUT OF THE SOUTH TO SOUTHWEST. THIS PERSISTENT FLOW WILL KEEP VERY MOIST AIR ACROSS THE WESTERN GREAT LAKES REGION. WHILE MOST OF THE FOG HAD DISSIPATED ON NORTHERN LAKE MICHIGAN...WITH THE MOIST AIR AND COOL LAKE WATER FOG IS EXPECTED TO REDEVELOP TONIGHT AND BECOME DENSE IN AREAS. THE CURRENT DENSE FOG ADVISORY FOR NORTHERN LAKE MICHIGAN WILL LIKELY NEED TO BE EXTENDED INTO TUESDAY AND POSSIBLY WEDNESDAY AS THERE WILL BE NO CHANGE IN AIRMASS UNTIL A COLD FRONT PUSHES ACROSS THE LAKE DURING LATER WEDNESDAY AND WEDNESDAY NIGHT...SHIFTING WINDS TO OUT OF THE WEST. A SECONDARY COLD FRONT WILL MOVE ACROSS THE LAKE AND SHIFT WINDS TO OUT OF THE NORTHWEST DURING LATER THURSDAY AND THURSDAY NIGHT. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 7 AM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
703 PM CDT SUN JUN 23 2013 .DISCUSSION... ISSUED 300 PM CDT SUN JUN 23 2013 TWO ONGOING COMPLEXES OF STORMS WILL HIGHLIGHT THE SHORT TERM...A LINE OF STORMS IN THE NW AND A CLUSTER OF HEAVY RAIN IN THE SE. HEAT AND PERIODIC STORM CHANCES WILL CONTINUE FOR MUCH OF THE WEEK UNTIL A MORE SIGNIFICANT UPPER WAVE MAKES PROGRESS FROM CANADA ACROSS THE GREAT LAKES AND CHANGES OUR UPPER FLOW OUT OF THE NORTHWEST...AS A TROUGH DEVELOPS IN THE EAST AND A RIDGE TO OUR WEST. SHORT TERM...TONIGHT THROUGH THURSDAY. THE HEAVY RAIN COMPLEX IN THE SOUTHEAST ASSOCIATED WITH A MESO- VORTEX APPEARS TO BE WEAKENING...ALBEIT WITH STEADY RAINS CONTINUING ACROSS A WATER-LOGGED AREA. SEVERAL FLASH FLOOD WARNINGS REMAIN IN EFFECT INTO THIS EVENING FOR THAT AREA...WHERE 3-5 INCHES OF RAIN HAS FALLEN. SPC MESO-ANALYSIS GRAPHICS SHOW INSTABILITY PARAMETERS IN THE SE AREA APPEAR TO BE STABILIZING...WHILE BETTER SUPPORT FOR STRONG STORMS EXISTS AHEAD OF THE LINE OF STORMS ENTERING OUR NW COUNTIES. ML-CAPE VALUES OF 3000-3500 J/KG SHOULD BE ENOUGH TO KEEP THEM ADVANCING INTO OUR AREA. PRECIPITABLE WATER VALUES AROUND 1.7" AND VERY WEAK WINDS IN THE MID-UPPER LEVELS LEND SUPPORT FOR HEAVY RAIN FROM THOSE STORMS INTO THIS EVENING. THEY SHOULD MAINTAIN BETTER FORWARD PROGRESS BASED ON THE MOVEMENT OF THE UPPER SHORTWAVE ON WATER VAPOR SATELLITE. THE TRACK OF THE LINE OF STORMS SHOULD EVENTUALLY BEGIN TO CURL TO THE SOUTHEAST. WE TRIED TO MATCH POPS TO CURRENT CONDITIONS AND PROGRESS THEM THROUGH THE EVENING AND OVERNIGHT UTILIZING SATELLITE AND RADAR TRENDS. MODELS HAVE GENERALLY BEEN ALL OVER THE PLACE WITH CONVECTIVE SOLUTIONS...SO THEY HAVE NOT BEEN MUCH HELP TO FORECAST DETAILS IN THE NEAR TERM. WE USED GENERAL MODEL TRENDS WITH THE PROGRESS OF THE OVERALL PATTERN THROUGH MID WEEK. WE EXPECT TO REMAIN IN THE WARM SECTOR THROUGH THURSDAY...A GRADUAL BUILDING OF THE UPPER LEVEL RIDGE INTO CENTRAL IL FOR TUESDAY AND TUESDAY NIGHT...WHICH MAY HELP SUPPRESS STORMS FOR AROUND 24 HOURS. WE KEPT SLIGHT CHANCE POPS TUE-TUE NIGHT AS A RESULT. UPPER TROUGHING REDEVELOPS FOR WEDNESDAY AS A SURFACE TROUGH PROGRESSES ACROSS IL WED NIGHT INTO THURSDAY. THAT WILL INITIALLY ESTABLISH NORTHWEST FLOW ALOFT...AND BEGIN OUR AIRMASS CHANGE THAT IS PROJECTED TO FINALLY BECOME ESTABLISHED NEXT WEEKEND. IN THE MEAN TIME...TUESDAY AND WEDNESDAY LOOK TO BE OUR HOTTEST DAYS OF THIS WEEK...AS HEAT INDEX READINGS CLIMB INTO THE 100-105 RANGE EACH AFTERNOON AND EARLY EVENING...OUTSIDE OF ANY STORM COMPLEXES. WE INCREASED POPS INTO THE CHANCE CATEGORY FOR WED AFTERNOON AND CONTINUED CHANCE POPS WED NIGHT...CONFINING THEM TO THE EASTERN AREAS ON THURSDAY AS THE TROUGH PUSHES EAST INTO INDIANA. WE MAY SEE ANOTHER ROUND OF STRONG STORMS WITH HEAVY RAIN ALONG THAT FRONT...AS PLENTY OF MOISTURE POOLING IS PROJECTED TO OCCUR AHEAD OF THE SYSTEM. LONG TERM...FRIDAY THROUGH SUNDAY. A COOLING TREND SHOULD ALREADY BE NOTICEABLE ON FRIDAY AS SURFACE WINDS TURN OUT OF THE NORTHWEST AND DEWPOINTS BEGIN TO DROP FROM THE 70S INTO THE 60S. WE HELD ONTO A SLIGHT CHANCE OF SHOWERS AND STORMS ON FRIDAY...AS THE UPPER TROUGH AXIS DEPARTS EASTWARD AND A 500MB SHORTWAVE ROTATES THROUGH THE BACK SIDE OF THE TROUGH. THE DAY SHOULD BE DOMINATED BY CLOUDS HELPING TO KEEP HIGHS IN THE MID 80S. DRY CONDITIONS SHOULD RETURN FRI NIGHT...WITH A FEW INSTABILITY SHOWERS POSSIBLE IN THE EAST ON SATURDAY AS THE COLD POOL ALOFT PASSES OVER THE AREA. HIGHS ON SATURDAY AND SUNDAY SHOULD TOP OUT IN THE LOWER 80S WITH OVERNIGHT LOWS IN THE LOW 60S...WITH MUCH LESS HUMIDITY IN THE AIR. && .AVIATION... ISSUED 658 PM CDT SUN JUN 23 2013 ADJUSTING FORECAST IN THE SHORT TERM TO HANDLE THE SLOWLY DWINDLING CONVECTION. PRECIP FALLING APART A BIT QUICKER THAN PREV MODEL RUNS ANTICIPATED...AND AS A RESULT HAVE LEFT TOO MUCH MENTION OF PRECIP IN MOST OF THE TAFS. CONCERN FOR PRECIP CONTINUES THROUGH TOMORROW THOUGH MODELS ARE ALL OVER THE PLACE. MOST FAITH IN HRRR FOR NOW...WHICH HAS A MORE SCT SIGNATURE. WILL AWAIT NEXT RUN BEFORE CALLING PRECIP AND TIMING FOR TOMORROW. HJS && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
657 PM CDT SUN JUN 23 2013 .DISCUSSION... 304 PM CDT SHOWER/THUNDER CHANCES REMAIN THE BIGGEST FORECAST CHALLENGE FOLLOWED BY TEMPS WHICH MAY BE AFFECTED BY THE CONVECTION. AFTERNOON WATER VAPOR IMAGERY SHOWS ONE UPPER LEVEL LOW SPINNING OVER THE CENTRAL APPALACHIANS WHICH IS LOSING DEFINITION AS IS MOVES SLOWLY NORTHWARD. THE NEXT UPPER LOW IS SPINNING OVER THE SOUTHERN CANADIAN PRAIRIES WITH A TROUGH AXIS EXTENDING INTO THE DAKOTAS AND LIFTING NORTHEAST. THE UPPER FLOW IS LESS AMPLIFIED FURTHER SOUTH OF THE LOW ACROSS THE CENTRAL PLAINS BUT THERE ARE SEVERAL EMBEDDED WAVES THAT ARE TRANSLATING NORTHEAST AS WELL. THE NEXT UPPER LOW OF NOTE IS COMING ONSHORE OVER THE WEST COAST AND HELPING TO AMPLIFY A RIDGE OVER OREGON/WASHINGTON. ENERGY EMANATING FROM THIS TROUGH WILL BECOME A PLAYER IN OUR WEATHER LATER THIS WEEK. AT THE SURFACE...LOW PRESSURE IS POSITIONED OVER NORTHWEST MINNESOTA WITH WEAKER LOW PRESSURE SPREAD ACROSS THE PLAINS. A COOL FRONTAL BOUNDARY IS STRETCHED FROM THE MN LOW BUT HAS BECOME DIFFICULT TO IDENTIFY THANKS TO COLD POOLS FROM MORNING CONVECTION. THROUGH THIS EVENING...TOUGH FORECAST ONCE AGAIN IN TERMS OF CONVECTIVE POTENTIAL AND EVOLUTION THROUGH THE PERIOD. OUTFLOW BOUNDARY FROM EARLIER IOWA CONVECTION IS NOW PUSHING INTO THE WESTERN CWA TRIGGERING THUNDERSTORMS ALONG IT. A BETTER ORGANIZED COMPLEX OF STORMS HAS DEVELOPED FROM THE EARLIER CONVECTION BUT IS MOVING SOUTHEAST ACROSS NORTHERN MISSOURI INTO THE AXIS OF MUCH BETTER INSTABILITY AS WELL AS BETTER MID LEVEL MOISTURE ADVECTION. ADDITIONAL SCATTERED STORMS HAVE DEVELOPED OVER THE SOUTHERN CWA LIKELY IN BETTER CONJUNCTION WITH THE WEAKENING UPPER LOW OVER APPALACHIA. IN THE NEAR TERM...EXPECT THE OUTFLOW TO CONTINUE EASTWARD ACROSS THE CWA TRIGGERING SCATTERED STORMS THROUGH LATE AFTERNOON/EARLY EVENING. MESOANALYSIS SHOWS 2000+ J/KG OF MIXED LAYER CAPE OVER THE AREA SUPPORTING STRONG UPDRAFTS BUT DEEP LAYER SHEAR IS WEAK SO CORES SHOULD BE PRETTY PULSEY. LARGE HAIL AND LOCALLY HEAVY DOWNPOURS ARE THE MAIN CONCERN. GUSTY WINDS ARE ALSO POSSIBLE BUT RECENT AIRCRAFT SOUNDINGS FROM MDW DO NOT SHOW A TON OF DRY LOW LEVEL AIR AND RAP ANALYSIS OF DCAPE IS LOW AS WELL. WOULD EXPECT THAT THIS ACTIVITY WOULD WANE WITH SUNSET. REST OF TONIGHT AND MONDAY...ATTENTION TURNS TO ADDITIONAL CONVECTIVE POTENTIAL OVERNIGHT. WATER VAPOR SHOWS A WAVE OVER NE KS/NW MO WHICH APPEARS TO BE TURNING MORE EASTWARD IN THE LAST FEW SCANS. THIS IS LIKELY HELPING THE COMPLEX TAKING SHAPE OVER MO. SHORT TERM/HIGH RES GUIDANCE HAS BEEN ALL OVER THE PLACE WITH HOW CONVECTION EVOLVES THROUGH TONIGHT. THE MOIST SOUTHWESTERLY FLOW WILL CONTINUE ACROSS THE REGION TONIGHT AND THE EARLIER COLD FRONTAL BOUNDARY SEEMS TO BE DEVELOPING ONCE AGAIN ACROSS IOWA AS THE FLOW HAS SETTLED FROM EARLIER CONVECTION. THIS IS SUPPORTIVE OF NEW DEVELOPMENT TO THE WEST TONIGHT. THE OUTFLOW CURRENTLY WORKING INTO THE LOCAL AREA EXTENDS INTO WEST-CENTRAL ILLINOIS AND THERE ARE HINTS THAT THE SOUTHERN EXTENT OF IT AND LIKELY A BOUNDARY SET UP BY THE CURRENT COMPLEX MAY STALL OUT SOMEWHERE NOT FAR FROM THE SOUTHWESTERN CWA. IN ADDITION...THE KS/MO WAVE IS EXPECTED TO CROSS THIS SAME AREA TONIGHT WHICH IS ALSO EXPECTED TO BE IN AN AREA OF MID LEVEL WARM ADVECTION. THEREFORE IT IS POSSIBLE ROUNDS OF CONVECTION COULD DEVELOP TO THE SOUTHWEST OF THE AREA AND ROLL EASTWARD INTO THE SOUTHERN CWA OVERNIGHT. HAVE NOT MADE MUCH CHANGE TO OVERNIGHT POPS BUT DID INCREASE THEM SOMEWHAT OVER THE FAR SOUTH. AS FOR MONDAY...GUIDANCE REMAINS IN POOR AGREEMENT WITH TRACK OF POTENTIAL UPPER WAVES BUT WATER VAPOR DOES SHOW SOME SIGNS OF A WAVE COMING ACROSS THE FOUR CORNERS THIS AFTERNOON. THIS WOULD COME ACROSS THE REGION LATER MONDAY BUT IT IS NOT CLEAR IF IT WILL BE MORE FOCUSED TO THE NORTH OF THE AREA. WILL CONTINUE WITH MID CHANCE POPS WITH LATER IN THE DAY MORE FAVORED. PROVIDED THE LATER TIMING WORKS OUT THEN WE WILL HAVE A BETTER CHANCE TO WARM BUT THERE MAY BE CONVECTIVE DEBRIS AROUND SO WILL HOLD TEMPS INTO THE MID 80S FOR MOST AREAS. TUESDAY THROUGH SUNDAY...THE UPPER FLOW BECOMES LESS AMPLIFIED TUESDAY BUT WILL LIKELY STILL BE LITTERED WITH WAVES TRAVERSING IT. HOT AND HUMID AIR WILL STILL BE IN PLACE WITH PRECIPITABLE WATER VALUES HOVERING AROUND 1.75 INCHES. THESE FACTORS PROVIDE CONTINUED SUPPORT FOR THUNDERSTORM DEVELOPMENT BUT THERE IS NOT MUCH TO KEY IN ON FOR A COHERENT FORCING MECHANISM GIVEN THE LOW AMPLITUDE PATTERN. BY WEDNESDAY...THERE IS SOME AGREEMENT ON SURFACE LOW PRESSURE HAVING DEVELOPED ACROSS THE CANADIAN PRAIRIES WITH A TROUGH AXIS/FRONT EXTENDING INTO MINNESOTA AND IOWA...WITH A SECONDARY LOW POSSIBLY DEVELOPING ACROSS MINNESOTA. THE FRONT LOOKS TO CROSS THE AREA LATER WEDNESDAY BRINGING SHOWER AND STORM CHANCES WITH IT. UPPER RIDGING WILL BE BUILDING ACROSS THE WESTERN U.S. AND HIGH PLAINS WITH A WAVE ORIGINATING FROM THE TROUGH OFF THE WEST COAST OVERTOPPING THE RIDGE ACROSS THE CANADIAN ROCKIES AND DROPPING SOUTHEASTWARD INTO THE GREAT LAKES WHILE AMPLIFYING LATE IN THE WEEK. GFS AND ECMWF DIFFER ON HOW QUICKLY THIS OCCURS BUT THE SIGNAL HAS BEEN CONSISTENT OVERALL. THIS WILL BRING A SHIFT TO NORTHWESTERLY AT THE SURFACE AND ALOFT LATE IN THE WEEK AND NOTICEABLY COOLER TEMPERATURES BY SATURDAY OR SO. LOW POPS WILL CONTINUE WITH THE FLOW CONTINUING TO FAVOR WEAK SHORTWAVE PASSAGES. HIGH TEMPS WILL LIKELY HOVER AROUND 90 TUESDAY AND WEDNESDAY ASSUMING CONVECTION OR CONVECTIVE DEBRIS IS NOT AN ISSUE...WHICH WOULD SIGNIFICANTLY LOWER HIGHS IF IT IS. WITH THE PASSAGE OF THE SYSTEM LATER WEDNESDAY COOLER MID LEVEL AIR WILL FILTER IN KEEPING HIGHS BACK IN THE 80S WITH UPPER 70S POSSIBLE FRIDAY AND SATURDAY. MDB && .HYDROLOGY... 304 PM CDT GAVE CONSIDERATION TO A FLASH FLOOD WATCH FOR THE WEST AND FAR SOUTHWEST CWA GIVEN THE RAINFALL OF THE PAST FEW DAYS. GIVEN FAIRLY LOW CONFIDENCE IN WHERE ORGANIZED CONVECTION WILL SET UP TONIGHT AND MONDAY WILL HOLD OFF UNTIL AREAS AND TIMING CAN BE BETTER DEFINED. CURRENT ACTIVITY IS STILL MOVING FAIRLY STEADILY BUT 1-1.5 INCHES OF RAIN PER HOUR ARE POSSIBLE LOCALLY. WILL PASS THE CONCERN ABOUT A WATCH TO THE EVENING SHIFT. MDB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * SHOWERS WILL LINGER ACROSS THE TERMINALS OVER THE NEXT COUPLE OF HOURS BEFORE DRIER CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE EVENING. * POSSIBILITY FOR A CONTINUED ACTIVE PERIOD WITH SEVERAL CHANCES FOR SHOWERS/THUNDERSTORMS TO MOVE ACROSS THE TERMINALS EARLY MONDAY MORNING THROUGH MONDAY EVENING. * SOUTHERLY WINDS AROUND 10KT EXPECTED THIS EVENING. RODRIGUEZ //DISCUSSION...UPDATED 00Z... THUNDERSTORMS HAVE HAVE SHOWN A RAPID DIMINISHING TREND OVER THE LAST HOUR AND EXPECT THIS TO CONTINUE WITH ONLY SHOWERS EXPECTED. AFTER THESE SHOWERS DIMINISH...DO EXPECT A DRY PERIOD FOR THE REMAINDER OF THE EVENING BEFORE CHANCES FOR SHOWERS/THUNDERSTORMS BEGIN TO INCREASE ONCE AGAIN EARLY MONDAY MORNING. SEVERAL CHANCES FOR SHOWERS AND THUNDERSTORMS DO APPEAR POSSIBLE THROUGHOUT THE DAY ON MONDAY...BUT WITH CONFIDENCE LOWER ON EXACT TIMING. ALTHOUGH...MONDAY AFTERNOON APPEARS AS IF IT COULD BE AN ACTIVE PERIOD. OUTSIDE OF THE THE PRECIP CHANCES THIS FORECAST PERIOD AND MAYBE SOME PATCHY FOG EARLY MONDAY MORNING...EXPECT VFR CONDITIONS WITH SOUTH/SOUTHWEST WINDS IN PLACE. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 00Z... * HIGH CONFIDENCE WITH SHOWER TRENDS OVER THE NEXT COUPLE OF HOURS. * LOW MEDIUM CONFIDENCE WITH PRECIP TRENDS EARLY MONDAY MORNING THROUGH MONDAY EVENING. * MEDIUM CONFIDENCE WITH WIND SPEED AND DIRECTION THIS EVENING. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH FRIDAY...PERIODIC CHANCES OF TSRA. SATURDAY...CHANCE OF SHRA. RODRIGUEZ && .MARINE... 420 PM CDT A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE WESTERN ATLANTIC SOUTHWESTWARD ACROSS THE SOUTHEASTERN U.S. AND THE NORTHERN GULF OF MEXICO. THIS HIGH WILL BE MOVING ONLY VERY SLOWLY SOUTHEASTWARD TONIGHT THROUGH THURSDAY. LOW PRESSURE NEAR LAKE WINNIPEG WILL BE MOVING SLOWLY EASTWARD ACROSS ONTARIO...REACHING NEAR SOUTHERN JAMES BAY BY TUESDAY MORNING. THEN...AN AREA OF LOW PRESSURE STRETCHING FROM THE SOUTHERN CANADIAN PRAIRIE SOUTH ACROSS THE PLAINS WILL MOVE NORTHEAST DURING TUESDAY AND WEDNESDAY. WITH HIGH PRESSURE SITUATED FAR TO THE SOUTH THROUGH SOUTHEAST OF THE LAKE AND LOW PRESSURE FROM FAR WEST THROUGH NORTHWEST TONIGHT INTO THURSDAY...MODERATE TO FRESH WINDS WILL PERSIST OUT OF THE SOUTH TO SOUTHWEST. THIS PERSISTENT FLOW WILL KEEP VERY MOIST AIR ACROSS THE WESTERN GREAT LAKES REGION. WHILE MOST OF THE FOG HAD DISSIPATED ON NORTHERN LAKE MICHIGAN...WITH THE MOIST AIR AND COOL LAKE WATER FOG IS EXPECTED TO REDEVELOP TONIGHT AND BECOME DENSE IN AREAS. THE CURRENT DENSE FOG ADVISORY FOR NORTHERN LAKE MICHIGAN WILL LIKELY NEED TO BE EXTENDED INTO TUESDAY AND POSSIBLY WEDNESDAY AS THERE WILL BE NO CHANGE IN AIRMASS UNTIL A COLD FRONT PUSHES ACROSS THE LAKE DURING LATER WEDNESDAY AND WEDNESDAY NIGHT...SHIFTING WINDS TO OUT OF THE WEST. A SECONDARY COLD FRONT WILL MOVE ACROSS THE LAKE AND SHIFT WINDS TO OUT OF THE NORTHWEST DURING LATER THURSDAY AND THURSDAY NIGHT. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 7 AM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1258 PM CDT SAT JUN 22 2013 .DISCUSSION... ISSUED 1044 AM CDT SAT JUN 22 2013 CONVECTIVE CHANCES REMAIN MAIN CONCERN TODAY. PRIMARY OUTFLOW BOUNDARY IS CURRENTLY PUSHING SOUTH INTO THE NORTHEAST CWA WITH SCATTERED THUNDERSTORMS DEVELOPING BEHIND THIS FEATURE. THIS SHOULD CONTINUE INTO EARLY AFTERNOON AS THE BOUNDARY SLIPS SOUTH...HOWEVER IT SHOULD EVENTUALLY SLOW AND STALL /UNLESS MORE VIGOROUS CONVECTION KEEPS COLD POOL GOING/ AS IT ENCOUNTERS 10-20 KT SOUTHWEST SYNOPTIC FLOW. SCATTERED SHOWERS AND SPRINKLES AFFECTING PARTS OF THE WESTERN CWA OUT OF A MID LEVEL DECK AND FEEL THIS AREA COULD FILL IN WITH SCATTERED TSTMS WITH DAYTIME HEATING. 12Z ILX SOUNDING SHOWED HIGH CAPES AND VERY WEAK WINDS ALOFT...WHICH COMBINED WITH A 2 INCH P/W MAKES HEAVY RAIN RATES AND FREQUENT LIGHTNING MAIN THREATS WITH STORMS TODAY. ISOLATED PULSE TYPE NEAR SVR POSSIBLE DUE TO PRECIP LOADING BUT LOW BULK SHEAR MAKES MORE ORGANIZED SVR UNLIKELY. HAVE INCREASED POPS TO LOW CHANCE OVER MOST OF THE CWA WITH LIKELY POPS IN THE NE CWA WHERE MORE SIGNIFICANT OUTFLOW BOUNDARY SHIFTS THROUGH NEXT FEW HOURS. SUNNIER LOCATIONS SHOULD GET INTO THE LOWER 90S AND WITH DEWPOINTS IN THE LOWER 70S PEAK HEAT INDICES NEAR 100 POSSIBLE. && .AVIATION... ISSUED 1258 PM CDT SAT JUN 22 2013 OUTFLOW BOUNDARY PUSHING THROUGH THE EASTERN TERMINAL WILL PRODUCE HIGHEST COVERAGE TSRA EARLY THIS AFTERNOON AFFECTING CMI AND POSSIBLY DEC. VERY HEAVY RAIN RATES BRINGING VSBYS DOWN BELOW 1SM IN HEAVIER STORMS. OTHERWISE ONLY ISOLATED ACTIVITY EXPECTED FARTHER WEST AND HAVE CARRIED VCTS THROUGH AFTERNOON. AFTER THIS SYSTEM PUSHES SOUTH NOT MUCH FOCUS FOR ADDITIONAL STORMS INTO SUNDAY MORNING AND MAINLY VFR SKIES EXPECTED. LATER FORECASTS WILL ADDRESS POSSIBLE MVFR FOG THAT COULD DEVELOP LATE TONIGHT IN LIGHTER WIND REGIME. SOUTHWEST WINDS WILL PICK UP OVER 10 KTS AFTER 14Z/SUN. 25 && .PREV DISCUSSION... ISSUED 250 AM CDT SAT JUN 22 2013 2 AM SATELLITE IMAGERY AND RADAR DATA SHOWING A PAIR OF MCS SYSTEMS MERGING FROM SOUTH DAKOTA EASTWARD INTO SOUTHERN WISCONSIN. EASTERN END OF THE LINE OF STORMS HAS MADE A SOUTHWARD PUSH INTO NORTHEAST ILLINOIS...WITH THIS PART OF THE MCS BECOMING THE DOMINANT ONE AS LIGHTNING DIMINISHES OVER SOUTHERN MINNESOTA. LINGERING BOUNDARY FROM THE STORMS IN OUR AREA YESTERDAY WRAPS AROUND THE SOUTHWEST AND SOUTHEAST PARTS OF THE FORECAST AREA. STILL SEEING A FEW SPRINKLES IN THE FAR SOUTHEAST CWA WITH THIS BOUNDARY. FORECAST CHALLENGES FOR THIS PACKAGE GENERALLY REVOLVE AROUND TIMING OF THUNDERSTORM CHANCES...AS WELL AS THE ONGOING HEAT AND HUMIDITY. SHORT TERM...TODAY THROUGH MONDAY... MODELS ARE STRUGGLING TO GET A HANDLE ON THE CURRENT SITUATION... WITH THE HRRR AND THE REGIONAL CANADIAN MODEL CLOSEST TO REALITY. NEITHER OF THESE MODELS SHOW THE STORMS MAKING IT AS FAR SOUTH AS OUR FORECAST AREA...BUT AS THE MCS FROM YESTERDAY SHOWED...THAT OUTCOME IS DEFINITELY NOT GUARANTEED. WILL INCLUDE SOME ISOLATED THUNDERSTORM MENTION IN THE NORTHEAST THIRD OF THE CWA THIS MORNING...BETWEEN THIS LINE AND POTENTIALLY SOME DEVELOPMENT ALONG THE OUTFLOW BOUNDARY...WITH AROUND 30 PERCENT CHANCES ACROSS THE NORTHEAST DURING THE AFTERNOON. HAVE MENTIONED ISOLATED STORMS ELSEWHERE THIS AFTERNOON AND EARLY EVENING. FOCUS CONTINUES TO BE WITH TIMING OF VARIOUS MCS FEATURES THIS WEEKEND. DEVELOPMENT ACROSS IOWA/MINNESOTA ON SUNDAY EXPECTED TO EXTEND SOUTHWEST INTO MISSOURI...BUT ONLY THE NAM BRINGS ANY OF IT THIS FAR EAST BY MONDAY MORNING. HAVE LIMITED ANY 30 PERCENT OR HIGHER POPS TO THE FAR NORTHWEST LATE SUNDAY NIGHT... WITH MORE WIDESPREAD CHANCES MONDAY. THE ECMWF AND CANADIAN MODELS SHOW THE MCS SPREADING OVER THE FORECAST AREA... WHILE THE NAM AND GFS SHUNT IT MORE TO THE NORTHEAST. SEVERE WEATHER POTENTIAL APPEARS TO INCREASE BY MONDAY...MAINLY IN THE NORTHWEST CWA. HAVE KEPT HIGH TEMPERATURES RIGHT AROUND 90 DEGREES FOR THE NEXT FEW DAYS...WITH HEAT INDEX VALUES IN THE MID TO UPPER 90S. WILL HAVE TO KEEP AN EYE ON HIGHS FOR MONDAY THOUGH...AS THEY COULD BE LOWER IF THIS MCS DOES PAN OUT. LONG TERM...TUESDAY THROUGH FRIDAY... BROAD EAST-WEST RIDGE EXPECTED TO COVER THE SOUTH HALF OF THE CONUS MUCH OF THE WEEK...WITH THE MAIN STORM TRACK ACROSS THE NORTHERN STATES. MCS TRACKS REMAINS THE CONCERN AND ALTHOUGH MANY OF THEM ARE FURTHER NORTH...LEFTOVER OUTFLOWS MAKE IT DIFFICULT TO PIN DOWN ANY DRY PERIODS WITH ANY CERTAINTY. HIGHEST POPS FROM WEDNESDAY NIGHT TO FRIDAY ARE TIED INTO PASSAGE OF A COLD FRONT... WHICH MAY TAKE UNTIL EARLY FRIDAY TO FULLY PASS THE REGION AS THE UPPER RIDGING BUILDS ACROSS THE ROCKIES AND PUTS THE MIDWEST MORE OF A TROUGH. THIS PARTICULAR PATTERN WOULD SHOW THE HEAT FINALLY BREAKING ON FRIDAY...WITH COOLER CONDITIONS NEXT WEEKEND. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1044 AM CDT SAT JUN 22 2013 .DISCUSSION... ISSUED 1044 AM CDT SAT JUN 22 2013 CONVECTIVE CHANCES REMAIN MAIN CONCERN TODAY. PRIMARY OUTFLOW BOUNDARY IS CURRENTLY PUSHING SOUTH INTO THE NORTHEAST CWA WITH SCATTERED THUNDERSTORMS DEVELOPING BEHIND THIS FEATURE. THIS SHOULD CONTINUE INTO EARLY AFTERNOON AS THE BOUNDARY SLIPS SOUTH...HOWEVER IT SHOULD EVENTUALLY SLOW AND STALL /UNLESS MORE VIGOROUS CONVECTION KEEPS COLD POOL GOING/ AS IT ENCOUNTERS 10-20 KT SOUTHWEST SYNOPTIC FLOW. SCATTERED SHOWERS AND SPRINKLES AFFECTING PARTS OF THE WESTERN CWA OUT OF A MID LEVEL DECK AND FEEL THIS AREA COULD FILL IN WITH SCATTERED TSTMS WITH DAYTIME HEATING. 12Z ILX SOUNDING SHOWED HIGH CAPES AND VERY WEAK WINDS ALOFT...WHICH COMBINED WITH A 2 INCH P/W MAKES HEAVY RAIN RATES AND FREQUENT LIGHTNING MAIN THREATS WITH STORMS TODAY. ISOLATED PULSE TYPE NEAR SVR POSSIBLE DUE TO PRECIP LOADING BUT LOW BULK SHEAR MAKES MORE ORGANIZED SVR UNLIKELY. HAVE INCREASED POPS TO LOW CHANCE OVER MOST OF THE CWA WITH LIKELY POPS IN THE NE CWA WHERE MORE SIGNIFICANT OUTFLOW BOUNDARY SHIFTS THROUGH NEXT FEW HOURS. SUNNIER LOCATIONS SHOULD GET INTO THE LOWER 90S AND WITH DEWPOINTS IN THE LOWER 70S PEAK HEAT INDICES NEAR 100 POSSIBLE. 25 && .AVIATION... ISSUED 520 AM CDT SAT JUN 22 2013 COVERAGE OF TSRA AND THE AFFECTS ON CIGS/VSBYS THIS FORECAST PERIOD. MID LEVEL MOISTURE HAS RAPIDLY DEVELOPED ACRS THE AREA THIS MORNING IN ADVANCE OF A WEAK UPPER LEVEL DISTURBANCE COUPLED WITH SOME ELEVATED INSTABILITY. JUST HOW MUCH SHOWER DEVELOPMENT TAKES PLACE IS STILL IN QUESTION AHEAD OF THIS SYSTEM...BUT WILL COVER FOR NOW WITH VCTS AND CONTINUE TO TRY TO PIN DOWN SOME BETTER TIMING OF STORMS IN THE AFTN HOURS. STILL APPEARS THE COVERAGE SHOULD QUICKLY DIMINISH JUST AFTR SUNSET THIS EVENING WITH MAIN MID AND HIGH LEVEL MOISTURE REMAINING TONIGHT. IF SKIES SHOULD CLEAR OUT LATER TONIGHT WE MAY HAVE TO DEAL WITH SOME PATCHY GROUND FOG...BUT FOR NOW WILL LEAVE OUT OF TAFS. SFC WINDS WILL REMAIN OUT OF A SSW (180-210) DIRECTION THRU THIS FORECAST PERIOD. SPEEDS WILL RANGE FROM 10 TO 15 KTS TODAY WITH A FEW GUSTS IN THE 15 TO 20 KT RANGE AND THEN DIMINISH TO AROUND 10 KTS THIS EVENING. SMITH && .PREV DISCUSSION... ISSUED 250 AM CDT SAT JUN 22 2013 2 AM SATELLITE IMAGERY AND RADAR DATA SHOWING A PAIR OF MCS SYSTEMS MERGING FROM SOUTH DAKOTA EASTWARD INTO SOUTHERN WISCONSIN. EASTERN END OF THE LINE OF STORMS HAS MADE A SOUTHWARD PUSH INTO NORTHEAST ILLINOIS...WITH THIS PART OF THE MCS BECOMING THE DOMINANT ONE AS LIGHTNING DIMINISHES OVER SOUTHERN MINNESOTA. LINGERING BOUNDARY FROM THE STORMS IN OUR AREA YESTERDAY WRAPS AROUND THE SOUTHWEST AND SOUTHEAST PARTS OF THE FORECAST AREA. STILL SEEING A FEW SPRINKLES IN THE FAR SOUTHEAST CWA WITH THIS BOUNDARY. FORECAST CHALLENGES FOR THIS PACKAGE GENERALLY REVOLVE AROUND TIMING OF THUNDERSTORM CHANCES...AS WELL AS THE ONGOING HEAT AND HUMIDITY. SHORT TERM...TODAY THROUGH MONDAY... MODELS ARE STRUGGLING TO GET A HANDLE ON THE CURRENT SITUATION... WITH THE HRRR AND THE REGIONAL CANADIAN MODEL CLOSEST TO REALITY. NEITHER OF THESE MODELS SHOW THE STORMS MAKING IT AS FAR SOUTH AS OUR FORECAST AREA...BUT AS THE MCS FROM YESTERDAY SHOWED...THAT OUTCOME IS DEFINITELY NOT GUARANTEED. WILL INCLUDE SOME ISOLATED THUNDERSTORM MENTION IN THE NORTHEAST THIRD OF THE CWA THIS MORNING...BETWEEN THIS LINE AND POTENTIALLY SOME DEVELOPMENT ALONG THE OUTFLOW BOUNDARY...WITH AROUND 30 PERCENT CHANCES ACROSS THE NORTHEAST DURING THE AFTERNOON. HAVE MENTIONED ISOLATED STORMS ELSEWHERE THIS AFTERNOON AND EARLY EVENING. FOCUS CONTINUES TO BE WITH TIMING OF VARIOUS MCS FEATURES THIS WEEKEND. DEVELOPMENT ACROSS IOWA/MINNESOTA ON SUNDAY EXPECTED TO EXTEND SOUTHWEST INTO MISSOURI...BUT ONLY THE NAM BRINGS ANY OF IT THIS FAR EAST BY MONDAY MORNING. HAVE LIMITED ANY 30 PERCENT OR HIGHER POPS TO THE FAR NORTHWEST LATE SUNDAY NIGHT... WITH MORE WIDESPREAD CHANCES MONDAY. THE ECMWF AND CANADIAN MODELS SHOW THE MCS SPREADING OVER THE FORECAST AREA... WHILE THE NAM AND GFS SHUNT IT MORE TO THE NORTHEAST. SEVERE WEATHER POTENTIAL APPEARS TO INCREASE BY MONDAY...MAINLY IN THE NORTHWEST CWA. HAVE KEPT HIGH TEMPERATURES RIGHT AROUND 90 DEGREES FOR THE NEXT FEW DAYS...WITH HEAT INDEX VALUES IN THE MID TO UPPER 90S. WILL HAVE TO KEEP AN EYE ON HIGHS FOR MONDAY THOUGH...AS THEY COULD BE LOWER IF THIS MCS DOES PAN OUT. LONG TERM...TUESDAY THROUGH FRIDAY... BROAD EAST-WEST RIDGE EXPECTED TO COVER THE SOUTH HALF OF THE CONUS MUCH OF THE WEEK...WITH THE MAIN STORM TRACK ACROSS THE NORTHERN STATES. MCS TRACKS REMAINS THE CONCERN AND ALTHOUGH MANY OF THEM ARE FURTHER NORTH...LEFTOVER OUTFLOWS MAKE IT DIFFICULT TO PIN DOWN ANY DRY PERIODS WITH ANY CERTAINTY. HIGHEST POPS FROM WEDNESDAY NIGHT TO FRIDAY ARE TIED INTO PASSAGE OF A COLD FRONT... WHICH MAY TAKE UNTIL EARLY FRIDAY TO FULLY PASS THE REGION AS THE UPPER RIDGING BUILDS ACROSS THE ROCKIES AND PUTS THE MIDWEST MORE OF A TROUGH. THIS PARTICULAR PATTERN WOULD SHOW THE HEAT FINALLY BREAKING ON FRIDAY...WITH COOLER CONDITIONS NEXT WEEKEND. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
523 AM CDT SAT JUN 22 2013 .DISCUSSION... ISSUED 250 AM CDT SAT JUN 22 2013 2 AM SATELLITE IMAGERY AND RADAR DATA SHOWING A PAIR OF MCS SYSTEMS MERGING FROM SOUTH DAKOTA EASTWARD INTO SOUTHERN WISCONSIN. EASTERN END OF THE LINE OF STORMS HAS MADE A SOUTHWARD PUSH INTO NORTHEAST ILLINOIS...WITH THIS PART OF THE MCS BECOMING THE DOMINANT ONE AS LIGHTNING DIMINISHES OVER SOUTHERN MINNESOTA. LINGERING BOUNDARY FROM THE STORMS IN OUR AREA YESTERDAY WRAPS AROUND THE SOUTHWEST AND SOUTHEAST PARTS OF THE FORECAST AREA. STILL SEEING A FEW SPRINKLES IN THE FAR SOUTHEAST CWA WITH THIS BOUNDARY. FORECAST CHALLENGES FOR THIS PACKAGE GENERALLY REVOLVE AROUND TIMING OF THUNDERSTORM CHANCES...AS WELL AS THE ONGOING HEAT AND HUMIDITY. SHORT TERM...TODAY THROUGH MONDAY... MODELS ARE STRUGGLING TO GET A HANDLE ON THE CURRENT SITUATION... WITH THE HRRR AND THE REGIONAL CANADIAN MODEL CLOSEST TO REALITY. NEITHER OF THESE MODELS SHOW THE STORMS MAKING IT AS FAR SOUTH AS OUR FORECAST AREA...BUT AS THE MCS FROM YESTERDAY SHOWED...THAT OUTCOME IS DEFINITELY NOT GUARANTEED. WILL INCLUDE SOME ISOLATED THUNDERSTORM MENTION IN THE NORTHEAST THIRD OF THE CWA THIS MORNING...BETWEEN THIS LINE AND POTENTIALLY SOME DEVELOPMENT ALONG THE OUTFLOW BOUNDARY...WITH AROUND 30 PERCENT CHANCES ACROSS THE NORTHEAST DURING THE AFTERNOON. HAVE MENTIONED ISOLATED STORMS ELSEWHERE THIS AFTERNOON AND EARLY EVENING. FOCUS CONTINUES TO BE WITH TIMING OF VARIOUS MCS FEATURES THIS WEEKEND. DEVELOPMENT ACROSS IOWA/MINNESOTA ON SUNDAY EXPECTED TO EXTEND SOUTHWEST INTO MISSOURI...BUT ONLY THE NAM BRINGS ANY OF IT THIS FAR EAST BY MONDAY MORNING. HAVE LIMITED ANY 30 PERCENT OR HIGHER POPS TO THE FAR NORTHWEST LATE SUNDAY NIGHT... WITH MORE WIDESPREAD CHANCES MONDAY. THE ECMWF AND CANADIAN MODELS SHOW THE MCS SPREADING OVER THE FORECAST AREA... WHILE THE NAM AND GFS SHUNT IT MORE TO THE NORTHEAST. SEVERE WEATHER POTENTIAL APPEARS TO INCREASE BY MONDAY...MAINLY IN THE NORTHWEST CWA. HAVE KEPT HIGH TEMPERATURES RIGHT AROUND 90 DEGREES FOR THE NEXT FEW DAYS...WITH HEAT INDEX VALUES IN THE MID TO UPPER 90S. WILL HAVE TO KEEP AN EYE ON HIGHS FOR MONDAY THOUGH...AS THEY COULD BE LOWER IF THIS MCS DOES PAN OUT. LONG TERM...TUESDAY THROUGH FRIDAY... BROAD EAST-WEST RIDGE EXPECTED TO COVER THE SOUTH HALF OF THE CONUS MUCH OF THE WEEK...WITH THE MAIN STORM TRACK ACROSS THE NORTHERN STATES. MCS TRACKS REMAINS THE CONCERN AND ALTHOUGH MANY OF THEM ARE FURTHER NORTH...LEFTOVER OUTFLOWS MAKE IT DIFFICULT TO PIN DOWN ANY DRY PERIODS WITH ANY CERTAINTY. HIGHEST POPS FROM WEDNESDAY NIGHT TO FRIDAY ARE TIED INTO PASSAGE OF A COLD FRONT... WHICH MAY TAKE UNTIL EARLY FRIDAY TO FULLY PASS THE REGION AS THE UPPER RIDGING BUILDS ACROSS THE ROCKIES AND PUTS THE MIDWEST MORE OF A TROUGH. THIS PARTICULAR PATTERN WOULD SHOW THE HEAT FINALLY BREAKING ON FRIDAY...WITH COOLER CONDITIONS NEXT WEEKEND. GEELHART && .AVIATION... ISSUED 520 AM CDT SAT JUN 22 2013 COVERAGE OF TSRA AND THE AFFECTS ON CIGS/VSBYS THIS FORECAST PERIOD. MID LEVEL MOISTURE HAS RAPIDLY DEVELOPED ACRS THE AREA THIS MORNING IN ADVANCE OF A WEAK UPPER LEVEL DISTURBANCE COUPLED WITH SOME ELEVATED INSTABILITY. JUST HOW MUCH SHOWER DEVELOPMENT TAKES PLACE IS STILL IN QUESTION AHEAD OF THIS SYSTEM...BUT WILL COVER FOR NOW WITH VCTS AND CONTINUE TO TRY TO PIN DOWN SOME BETTER TIMING OF STORMS IN THE AFTN HOURS. STILL APPEARS THE COVERAGE SHOULD QUICKLY DIMINISH JUST AFTR SUNSET THIS EVENING WITH MAIN MID AND HIGH LEVEL MOISTURE REMAINING TONIGHT. IF SKIES SHOULD CLEAR OUT LATER TONIGHT WE MAY HAVE TO DEAL WITH SOME PATCHY GROUND FOG...BUT FOR NOW WILL LEAVE OUT OF TAFS. SFC WINDS WILL REMAIN OUT OF A SSW (180-210) DIRECTION THRU THIS FORECAST PERIOD. SPEEDS WILL RANGE FROM 10 TO 15 KTS TODAY WITH A FEW GUSTS IN THE 15 TO 20 KT RANGE AND THEN DIMINISH TO AROUND 10 KTS THIS EVENING. SMITH && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
252 AM CDT SAT JUN 22 2013 .DISCUSSION... ISSUED 250 AM CDT SAT JUN 22 2013 2 AM SATELLITE IMAGERY AND RADAR DATA SHOWING A PAIR OF MCS SYSTEMS MERGING FROM SOUTH DAKOTA EASTWARD INTO SOUTHERN WISCONSIN. EASTERN END OF THE LINE OF STORMS HAS MADE A SOUTHWARD PUSH INTO NORTHEAST ILLINOIS...WITH THIS PART OF THE MCS BECOMING THE DOMINANT ONE AS LIGHTNING DIMINISHES OVER SOUTHERN MINNESOTA. LINGERING BOUNDARY FROM THE STORMS IN OUR AREA YESTERDAY WRAPS AROUND THE SOUTHWEST AND SOUTHEAST PARTS OF THE FORECAST AREA. STILL SEEING A FEW SPRINKLES IN THE FAR SOUTHEAST CWA WITH THIS BOUNDARY. FORECAST CHALLENGES FOR THIS PACKAGE GENERALLY REVOLVE AROUND TIMING OF THUNDERSTORM CHANCES...AS WELL AS THE ONGOING HEAT AND HUMIDITY. SHORT TERM...TODAY THROUGH MONDAY... MODELS ARE STRUGGLING TO GET A HANDLE ON THE CURRENT SITUATION... WITH THE HRRR AND THE REGIONAL CANADIAN MODEL CLOSEST TO REALITY. NEITHER OF THESE MODELS SHOW THE STORMS MAKING IT AS FAR SOUTH AS OUR FORECAST AREA...BUT AS THE MCS FROM YESTERDAY SHOWED...THAT OUTCOME IS DEFINITELY NOT GUARANTEED. WILL INCLUDE SOME ISOLATED THUNDERSTORM MENTION IN THE NORTHEAST THIRD OF THE CWA THIS MORNING...BETWEEN THIS LINE AND POTENTIALLY SOME DEVELOPMENT ALONG THE OUTFLOW BOUNDARY...WITH AROUND 30 PERCENT CHANCES ACROSS THE NORTHEAST DURING THE AFTERNOON. HAVE MENTIONED ISOLATED STORMS ELSEWHERE THIS AFTERNOON AND EARLY EVENING. FOCUS CONTINUES TO BE WITH TIMING OF VARIOUS MCS FEATURES THIS WEEKEND. DEVELOPMENT ACROSS IOWA/MINNESOTA ON SUNDAY EXPECTED TO EXTEND SOUTHWEST INTO MISSOURI...BUT ONLY THE NAM BRINGS ANY OF IT THIS FAR EAST BY MONDAY MORNING. HAVE LIMITED ANY 30 PERCENT OR HIGHER POPS TO THE FAR NORTHWEST LATE SUNDAY NIGHT... WITH MORE WIDESPREAD CHANCES MONDAY. THE ECMWF AND CANADIAN MODELS SHOW THE MCS SPREADING OVER THE FORECAST AREA... WHILE THE NAM AND GFS SHUNT IT MORE TO THE NORTHEAST. SEVERE WEATHER POTENTIAL APPEARS TO INCREASE BY MONDAY...MAINLY IN THE NORTHWEST CWA. HAVE KEPT HIGH TEMPERATURES RIGHT AROUND 90 DEGREES FOR THE NEXT FEW DAYS...WITH HEAT INDEX VALUES IN THE MID TO UPPER 90S. WILL HAVE TO KEEP AN EYE ON HIGHS FOR MONDAY THOUGH...AS THEY COULD BE LOWER IF THIS MCS DOES PAN OUT. LONG TERM...TUESDAY THROUGH FRIDAY... BROAD EAST-WEST RIDGE EXPECTED TO COVER THE SOUTH HALF OF THE CONUS MUCH OF THE WEEK...WITH THE MAIN STORM TRACK ACROSS THE NORTHERN STATES. MCS TRACKS REMAINS THE CONCERN AND ALTHOUGH MANY OF THEM ARE FURTHER NORTH...LEFTOVER OUTFLOWS MAKE IT DIFFICULT TO PIN DOWN ANY DRY PERIODS WITH ANY CERTAINTY. HIGHEST POPS FROM WEDNESDAY NIGHT TO FRIDAY ARE TIED INTO PASSAGE OF A COLD FRONT... WHICH MAY TAKE UNTIL EARLY FRIDAY TO FULLY PASS THE REGION AS THE UPPER RIDGING BUILDS ACROSS THE ROCKIES AND PUTS THE MIDWEST MORE OF A TROUGH. THIS PARTICULAR PATTERN WOULD SHOW THE HEAT FINALLY BREAKING ON FRIDAY...WITH COOLER CONDITIONS NEXT WEEKEND. GEELHART && .AVIATION... ISSUED 1154 PM CDT FRI JUN 21 2013 MAIN ISSUE FOR THE TAFS REMAINS THE NEXT ROUND OF CONVECTION AND THAT LACK OF CONFIDENCE IN ANY MODEL OUTPUT HELPING WITH THE CALL. GFS REMAINS STORMY IN THE SHORT TERM...AND DRY TOMORROW AFTERNOON. WHILE THE NAM/WRF IS MORE FOCUSED ON SHOWERS AND THUNDERSTORMS FROM MID MORNING ON THROUGH THE AFTERNOON. HAVE TRIED TO SPLIT THE DIFFERENCE IN THE CURRENT FORECAST WITH A NOD TO PERSISTENCE AND YESTERDAYS MCS. BEST CHANCES FOR TSRA IN THE AFTERNOON. SOUTHERLY WINDS DOMINATE...AS WELL AS VFR...THOUGH OBVIOUSLY A DROP IN TS ACTIVITY. TIMING AND COVERAGE CONFIDENCE LOWER THAN NORMAL. HJS && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1158 PM CDT FRI JUN 21 2013 .DISCUSSION... ISSUED 915 PM CDT FRI JUN 21 2013 WITH THE REMAINS OF THE DYING MCS MOVING OUT OF THE STATE TO THE EAST/SE...PULLING POPS IN THE OVERNIGHT FOR THE AREA. KEEPING SOME SLIGHTS IN THE EAST FOR ANY REDEVELOPMENT...BUT THE SYSTEM IS PULLING TOO FAR TO THE EAST AND THE CURRENT RUC/RAPP RUN IS MOSTLY DRY IN THE OVERNIGHT. ONLY CONCERN FOR THE OVERNIGHT IS THE POTENTIAL FOR PATCHY FOG WITH THE MOISTURE IN THE BOUNDARY LAYER DUE TO THE STORMS. BUT THE DWPTS ARE ACTUALLY LOWER IN THE AREAS THAT SAW RAIN...AND WELL BELOW THE EXPECTED LOWS. WILL CONTINUE TO MONITOR...UPDATES OUT MOMENTARILY. && .AVIATION... ISSUED 1154 PM CDT FRI JUN 21 2013 MAIN ISSUE FOR THE TAFS REMAINS THE NEXT ROUND OF CONVECTION AND THAT LACK OF CONFIDENCE IN ANY MODEL OUTPUT HELPING WITH THE CALL. GFS REMAINS STORMY IN THE SHORT TERM...AND DRY TOMORROW AFTERNOON. WHILE THE NAM/WRF IS MORE FOCUSED ON SHOWERS AND THUNDERSTORMS FROM MIDMORNING ON THROUGH THE AFTERNOON. HAVE TRIED TO SPLIT THE DIFFERENCE IN THE CURRENT FORECAST WITH A NOD TO PERSISTENCE AND YESTERDAYS MCS. BEST CHANCES FOR TSRA IN THE AFTERNOON. SOUTHERLY WINDS DOMINATE...AS WELL AS VFR...THOUGH OBVIOUSLY A DROP IN TS ACTIVITY. TIMING AND COVERAGE CONFIDENCE LOWER THAN NORMAL. HJS && .PREV DISCUSSION... ISSUED 300 PM CDT FRI JUN 21 2013 INITIAL CONCERNS WILL FOCUS ON THE SEVERE POTENTIAL WITH THE LINE OF STORMS MOVING ACROSS OUR NORTHERN COUNTIES. THEN ATTENTION TURNS TO THE HEAT AND HUMIDITY WITH PERIODIC STORM CHANCES IN THIS SUMMER PATTERN. THE EXTENDED FORECAST STILL CALLS FOR OUR NEXT COLD FRONT TO ARRIVE AROUND THURSDAY. SHORT TERM...TONIGHT THROUGH MONDAY. A 30-40 MPH SOUTHWARD MOVING GUST FRONT IS GENERALLY OUTRUNNING THE LINE OF STORMS BY 5 TO 10 MILES IN MOST AREAS...EXCEPT FOR IN THE MID-PORTION OF THE LINE FROM DELAVAN TO BLOOMINGTON. STORM INITIATION REMAINS CLOSER TO THE GUST FRONT IN THAT AREA. THOSE STORMS ARE THE STRONGEST AT 230 PM...BUT STILL APPEAR TO BE SUB- SEVERE. HAIL AND WIND REPORTS HAVE BEEN SPARSE, BUT A FEW TREE LIMBS MAY HAVE BEEN KNOCKED DOWN NEAR DUNLAP AND THE LARGEST HAIL REPORT WAS DIME SIZED 1N OF MOSSVILLE EARLIER. STORM INTENSITY HAS GENERALLY WEAKENED SINCE THOSE REPORTS...SO WE CONTINUE TO MONITOR FOR ANY INTENSIFICATION. SPC MESO-ANALYSIS PAGE SHOWS MORE STABLE AIR AHEAD OF THE STORMS...WITH WEAKER 0-6KM BULK SHEAR. THERE IS STILL 1500 J/KG MUCAPE AVAILABLE...SO THE STORMS MAY LINGER AT LEAST UNTIL THE INDIANA BORDER EARLY THIS EVENING. INTO EARLY EVENING...A COUPLE 4KM MODELS ARE SHOWING ADDITIONAL STORM DEVELOPMENT FARTHER WEST IN EASTERN IOWA/NE MO WHERE INSTABILITY AND SHEAR PARAMS ARE MORE FAVORABLE FOR STORMS. HOWEVER...THE 18Z HRRR RUN DOES NOT HAVE ANY INDICATION OF THOSE STORMS. TAKING EVERYTHING INTO CONSIDERATION...WE TRIED TO MAKE THE POPS/WEATHER GRIDS CONFORM CLOSELY TO THE NEXT 3-5 HOURS OF CONVECTION...THEN WENT MORE GENERAL BASED ON SATELLITE, RADAR AND OBSERVATION TRENDS. WE LINGERED SOME HIGHER POPS THROUGH 03Z THIS EVENING IN THE EAST TO TREND THE CURRENT STORMS EASTWARD...WITH SLIGHT CHANCE IN OUR WESTERN COUNTIES TO COVER THE NEXT LINE THAT MAY ARRIVE. THE REST OF THE NIGHT SHOULD BE MUGGY AND MILD...AS CLOUDS CLEAR OUT AND LINGERING NORTH WINDS BEHIND THIS LINE OF STORMS RETURNS TO SOUTHERLY. SATURDAY WILL BRING ANOTHER ROUND OF AFTERNOON SHOWERS AND STORMS AS HIGHS CLIMB INTO THE LOWER 90S AND HEAT INDICES REACH AROUND 100. SEVERE CHANCES SHOULD REMAIN LOW IN OUR COUNTIES...WITH THE SLIGHT RISK FOR DAY 2 NW OF ILLINOIS. THE TRIGGERS FOR STORMS MAY BE TIED TO THE RESIDUAL OUTFLOW BOUNDARIES FROM TODAY`S CONVECTION...AND THE PASSAGE OF A WEAK 500 MB SHORTWAVE. PRECIPITABLE WATER VALUES AROUND 1.75" WILL ALLOW SOME OF THE STRONGER STORMS TO BE VERY HEAVY RAIN PRODUCERS...WITH RAINFALL RATES OF 1-2" PER HOUR. LOCALIZED FLASH FLOODING WILL BE POSSIBLE...DESPITE THE RELATIVELY DRY CONDITIONS OVER THE PAST COUPLE OF WEEKS IN MOST AREAS. STORMS SHOULD COME TO AN END BY SATURDAY EVENING...WITH CLEARING SKIES OVERNIGHT. SUNDAY WILL SEE LESS FAVORABLE INSTABILITY PARAMS...AS MID LEVEL WARMING PROVIDES A BETTER CAP ON STORM DEVELOPMENT. WE KEPT A DRY FORECAST FOR SUNDAY...BUT KEPT THE HEAT AND HUMIDITY HIGH. HEAT INDEX READING SHOULD REMAIN BELOW SATURDAYS READINGS...BUT STILL IN THE MID TO UPPER 90S. MONDAY WILL SEE THE RETURN OF STORM CHANCES AS THE NEXT 500MB SHORTWAVE CREATES SOME FALLING HEIGHTS AND DESTABILIZES THE LOWER TROPOSPHERE. STORM DEVELOPMENT SHOULD OCCUR IN THE AFTERNOON...AS SURFACE HEATING HELPS TO ERODE THE CAP. WE WENT WITH CHANCE POPS IN THE NW HALF OF OUR FORECAST AREA...WITH SLIGHTS DOWN TO I-70. LONG TERM...TUESDAY THROUGH FRIDAY. ANOTHER LULL IN THE STORMS IS EXPECTED MONDAY NIGHT THRU TUESDAY NIGHT...AS THE UPPER TROUGH IN THE N PLAINS BEGINS TO BECOME PROGRESSIVE. AS THE UPPER TROUGH REACHES THE GREAT LAKES...A SURFACE COLD FRONT IS FORECAST TO MOVE ACROSS ILLINOIS ON THURSDAY OR THURSDAY NIGHT. SHOWERS AND STORMS WILL LIKELY DEVELOP ALONG THAT FEATURE...DESPITE THE WEAKER APPEARANCE OF THE FRONT IN THE EXTENDED MODELS. THE NORTHWEST FLOW BEHIND THAT COLD FRONT WILL HELP DROP HIGHS FROM THE LOW 90S ON TUESDAY AND WED...BACK INTO THE UPPER 80S THURSDAY AND LOWER 80S ON FRIDAY. DEWPOINTS WILL DROP INTO THE LOWER 60S ON FRIDAY AS WELL...PROVIDING SOME RELIEF FROM THE HEAT AND HUMIDITY. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
553 AM EDT SAT JUN 22 2013 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 307 AM EDT SAT JUN 22 2013 POTENTIAL EXISTS FOR OCCASIONAL UPPER DISTURBANCES...RIDING ALONG THE EDGE OF AN UPPER RIDGE...TO AFFECT CENTRAL INDIANA INTO THE MIDDLE OF NEXT WEEK. BY NEXT THURSDAY AND FRIDAY...A COLD FRONT MAY MOVE INTO THE AREA. && .NEAR TERM /TODAY/... ISSUED AT 307 AM EDT SAT JUN 22 2013 CONFIDENCE IS LOW IN THE THUNDERSTORM FORECAST FOR THIS WEEKEND. NONE OF THE MODELS APPEAR TO HAVE A HANDLE ON THE MCS CURRENTLY OVER MN AND WI. THE HRRR MAY BE THE ONLY MODEL TO PROVIDE SOME TRUTH TO WHAT WILL PREVAIL FOR LATER TODAY...AND THAT IS THE POTENTIAL FOR REMNANT MCS ACTIVITY TO EVENTUALLY WORK IT/S WAY SOUTH TO CENTRAL INDIANA BY THIS AFTERNOON AND EARLY EVENING. INCREASED POP COVERAGE TO INCLUDE THE ENTIRE CWA...WITH SLIGHTLY HIGHER CHANCE POPS ACROSS THE NORTHERN TIER WHERE ANY REMNANT ACTIVITY IS MOSTLY LIKELY TO REACH. IF THIS ACTIVITY DOES REACH CENTRAL INDIANA BY THIS AFTERNOON THEN TEMPERATURES WILL BE AFFECTED. SINCE CONFIDENCE IS LOW AT THIS JUNCTURE WILL CONTINUE WITH PERSISTENCE AND WARM HIGHS IN THE UPPER 80S TO AROUND 90. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... ISSUED AT 307 AM EDT SAT JUN 22 2013 SLIGHT CHANCE TO LOW CHANCE POPS WILL CONTINUE THIS EVENING AND THEN BY 06Z BE DRY. LOWS AROUND 70. SUNDAY AND MONDAY WILL BRING WITH IT SIMILAR CHALLENGES TO THE THUNDERSTORM FORECAST AS A FEW UPPER LEVEL DISTURBANCES ARE FORECAST TO MOVE THROUGH. INTRODUCED AT LEAST A SLIGHT CHANCE POP FOR SUNDAY AFTERNOON...AND AGAIN MONDAY AND MONDAY NIGHT. THE OTHER STORY THROUGH AT LEAST MID WEEK WILL BE THE SEASONABLY WARM TEMPERATURES WITH HIGHS REACHING AROUND THE 90 MARK. DID NOT STRAY FAR FROM MOS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... ISSUED AT 315 AM EDT SAT JUN 22 2013 A FAIRLY TYPICAL SUMMERTIME PATTERN WILL SET UP DURING THE EARLY TO MIDDLE PORTION OF THE WORK WEEK WITH ZONAL FLOW TO WEAK RIDGING ALOFT AND BROAD SOUTH TO SOUTHWEST FLOW NEAR THE SURFACE. CANNOT RULE OUT ISOLATED AFTERNOON THUNDERSTORMS UNDER THIS REGIME TUESDAY AND WEDNESDAY...ALTHOUGH CAPPING MAY BE A HINDRANCE...OTHERWISE EXPECT MAINLY DRY CONDITIONS EARLY WEEK. THINGS DO TRANSITION LATE WEEK WITH A MORE POTENT UPPER WAVE AND SURFACE SYSTEM MOVING THROUGH THE AREA WEDNESDAY NIGHT INTO EARLY FRIDAY. HIGHER POPS WILL BE NECESSARY HERE. ON TEMPS...ALLBLEND INITIALIZATION WAS REASONABLE...ALTHOUGH DID BUMP HIGHS UP A DEGREE IN SOME PERIODS TO ACCOUNT FOR POTENTIAL IMPACT OF OVERDONE PRECIP IN MODELS. MAXES/MINS WILL BE NEAR TO A BIT ABOVE CLIMO UNTIL VERY LATE IN THE PERIOD POST COLD FRONT...AS THE ZONAL TO WEAKLY ANTICYCLONIC PATTERN WOULD DICTATE. && .AVIATION /DISCUSSION FOR THE 22/12Z TAFS/... ISSUED AT 553 AM EDT SAT JUN 22 2013 VFR THROUGH THE PERIOD. SCT TO BKN MID TO HIGH LEVEL CLOUD ACROSS THE AREA THIS MORNING...DEBRIS FROM YESTERDAYS STORMS AND FROM UPSTREAM CONVECTION OVER NORTHERN ILLINOIS. EXPECT DEVELOPMENT OF BKN VFR CUMULUS TODAY...AND THUNDERSTORMS WILL BE POSSIBLE...BUT TOO LOW PROBABILITY AND TOO UNCERTAIN TO INCLUDE IN TAF AT THIS TIME. BEST TIME WOULD ONCE AGAIN BE AFTERNOON INTO EVENING HOURS. WINDS WILL BE 10KT OR LESS THROUGHOUT THE PERIOD...GENERALLY FROM 180-220 DEGREES. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...SMF NEAR TERM...SMF SHORT TERM...SMF LONG TERM....NIELD AVIATION...NIELD VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
429 AM EDT SAT JUN 22 2013 .UPDATE... THE LONG TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 307 AM EDT SAT JUN 22 2013 POTENTIAL EXISTS FOR OCCASIONAL UPPER DISTURBANCES...RIDING ALONG THE EDGE OF AN UPPER RIDGE...TO AFFECT CENTRAL INDIANA INTO THE MIDDLE OF NEXT WEEK. BY NEXT THURSDAY AND FRIDAY...A COLD FRONT MAY MOVE INTO THE AREA. && .NEAR TERM /TODAY/... ISSUED AT 307 AM EDT SAT JUN 22 2013 CONFIDENCE IS LOW IN THE THUNDERSTORM FORECAST FOR THIS WEEKEND. NONE OF THE MODELS APPEAR TO HAVE A HANDLE ON THE MCS CURRENTLY OVER MN AND WI. THE HRRR MAY BE THE ONLY MODEL TO PROVIDE SOME TRUTH TO WHAT WILL PREVAIL FOR LATER TODAY...AND THAT IS THE POTENTIAL FOR REMNANT MCS ACTIVITY TO EVENTUALLY WORK IT/S WAY SOUTH TO CENTRAL INDIANA BY THIS AFTERNOON AND EARLY EVENING. INCREASED POP COVERAGE TO INCLUDE THE ENTIRE CWA...WITH SLIGHTLY HIGHER CHANCE POPS ACROSS THE NORTHERN TIER WHERE ANY REMNANT ACTIVITY IS MOSTLY LIKELY TO REACH. IF THIS ACTIVITY DOES REACH CENTRAL INDIANA BY THIS AFTERNOON THEN TEMPERATURES WILL BE AFFECTED. SINCE CONFIDENCE IS LOW AT THIS JUNCTURE WILL CONTINUE WITH PERSISTENCE AND WARM HIGHS IN THE UPPER 80S TO AROUND 90. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... ISSUED AT 307 AM EDT SAT JUN 22 2013 SLIGHT CHANCE TO LOW CHANCE POPS WILL CONTINUE THIS EVENING AND THEN BY 06Z BE DRY. LOWS AROUND 70. SUNDAY AND MONDAY WILL BRING WITH IT SIMILAR CHALLENGES TO THE THUNDERSTORM FORECAST AS A FEW UPPER LEVEL DISTURBANCES ARE FORECAST TO MOVE THROUGH. INTRODUCED AT LEAST A SLIGHT CHANCE POP FOR SUNDAY AFTERNOON...AND AGAIN MONDAY AND MONDAY NIGHT. THE OTHER STORY THROUGH AT LEAST MID WEEK WILL BE THE SEASONABLY WARM TEMPERATURES WITH HIGHS REACHING AROUND THE 90 MARK. DID NOT STRAY FAR FROM MOS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... ISSUED AT 315 AM EDT SAT JUN 22 2013 A FAIRLY TYPICAL SUMMERTIME PATTERN WILL SET UP DURING THE EARLY TO MIDDLE PORTION OF THE WORK WEEK WITH ZONAL FLOW TO WEAK RIDGING ALOFT AND BROAD SOUTH TO SOUTHWEST FLOW NEAR THE SURFACE. CANNOT RULE OUT ISOLATED AFTERNOON THUNDERSTORMS UNDER THIS REGIME TUESDAY AND WEDNESDAY...ALTHOUGH CAPPING MAY BE A HINDRANCE...OTHERWISE EXPECT MAINLY DRY CONDITIONS EARLY WEEK. THINGS DO TRANSITION LATE WEEK WITH A MORE POTENT UPPER WAVE AND SURFACE SYSTEM MOVING THROUGH THE AREA WEDNESDAY NIGHT INTO EARLY FRIDAY. HIGHER POPS WILL BE NECESSARY HERE. ON TEMPS...ALLBLEND INITIALIZATION WAS REASONABLE...ALTHOUGH DID BUMP HIGHS UP A DEGREE IN SOME PERIODS TO ACCOUNT FOR POTENTIAL IMPACT OF OVERDONE PRECIP IN MODELS. MAXES/MINS WILL BE NEAR TO A BIT ABOVE CLIMO UNTIL VERY LATE IN THE PERIOD POST COLD FRONT...AS THE ZONAL TO WEAKLY ANTICYCLONIC PATTERN WOULD DICTATE. && .AVIATION /DISCUSSION FOR THE 22/09Z TAF UPDATE/... ISSUED AT 429 AM EDT SAT JUN 22 2013 NO SIGNIFICANT CHANGES NECESSARY. PREVIOUS DISCUSSION FOLLOWS. ISSUED AT 1213 AM EDT SAT JUN 22 2013 EXPECT MOSTLY VFR CONDITIONS EXCEPT PERHAPS SOME BRIEF OVERNIGHT FOG TONIGHT AT LAF AND MORESO AT HUF WHERE OVER AN INCH OF RAIN FELL LAST EVENING. HOWEVER...THINK THERE IS A BETTER CHANCE THAT CONVECTIVE DEBRIS CLOUDS WILL BE SUFFICIENT TO KEEP THE VISIBILITY P6SM ESPECIALLY AT LAF. COULD SEE A FEW MORE AFTERNOON STORMS MAINLY AFTER 16Z...BUT CHANCES TOO SMALL TO MENTION. DID GO WITH A BROKEN VFR CU DECK THOUGH TO STRESS CONVECTIVE POSSIBILITY. SOUTH AND SOUTHWEST 7 KNOTS OR LESS TONIGHT WILL INCREASE TO AROUND 10 KNOTS FROM THE SOUTHWEST AFTER 16Z SATURDAY AND BECOME LIGHT TO CALM AFTER 02Z SUNDAY. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...SMF NEAR TERM...SMF SHORT TERM...SMF LONG TERM....NIELD AVIATION...MK/NIELD VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
315 AM EDT SAT JUN 22 2013 .UPDATE... THE LONG TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 307 AM EDT SAT JUN 22 2013 POTENTIAL EXISTS FOR OCCASIONAL UPPER DISTURBANCES...RIDING ALONG THE EDGE OF AN UPPER RIDGE...TO AFFECT CENTRAL INDIANA INTO THE MIDDLE OF NEXT WEEK. BY NEXT THURSDAY AND FRIDAY...A COLD FRONT MAY MOVE INTO THE AREA. && .NEAR TERM /TODAY/... ISSUED AT 307 AM EDT SAT JUN 22 2013 CONFIDENCE IS LOW IN THE THUNDERSTORM FORECAST FOR THIS WEEKEND. NONE OF THE MODELS APPEAR TO HAVE A HANDLE ON THE MCS CURRENTLY OVER MN AND WI. THE HRRR MAY BE THE ONLY MODEL TO PROVIDE SOME TRUTH TO WHAT WILL PREVAIL FOR LATER TODAY...AND THAT IS THE POTENTIAL FOR REMNANT MCS ACTIVITY TO EVENTUALLY WORK IT/S WAY SOUTH TO CENTRAL INDIANA BY THIS AFTERNOON AND EARLY EVENING. INCREASED POP COVERAGE TO INCLUDE THE ENTIRE CWA...WITH SLIGHTLY HIGHER CHANCE POPS ACROSS THE NORTHERN TIER WHERE ANY REMNANT ACTIVITY IS MOSTLY LIKELY TO REACH. IF THIS ACTIVITY DOES REACH CENTRAL INDIANA BY THIS AFTERNOON THEN TEMPERATURES WILL BE AFFECTED. SINCE CONFIDENCE IS LOW AT THIS JUNCTURE WILL CONTINUE WITH PERSISTENCE AND WARM HIGHS IN THE UPPER 80S TO AROUND 90. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... ISSUED AT 307 AM EDT SAT JUN 22 2013 SLIGHT CHANCE TO LOW CHANCE POPS WILL CONTINUE THIS EVENING AND THEN BY 06Z BE DRY. LOWS AROUND 70. SUNDAY AND MONDAY WILL BRING WITH IT SIMILAR CHALLENGES TO THE THUNDERSTORM FORECAST AS A FEW UPPER LEVEL DISTURBANCES ARE FORECAST TO MOVE THROUGH. INTRODUCED AT LEAST A SLIGHT CHANCE POP FOR SUNDAY AFTERNOON...AND AGAIN MONDAY AND MONDAY NIGHT. THE OTHER STORY THROUGH AT LEAST MID WEEK WILL BE THE SEASONABLY WARM TEMPERATURES WITH HIGHS REACHING AROUND THE 90 MARK. DID NOT STRAY FAR FROM MOS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... ISSUED AT 315 AM EDT SAT JUN 22 2013 A FAIRLY TYPICAL SUMMERTIME PATTERN WILL SET UP DURING THE EARLY TO MIDDLE PORTION OF THE WORK WEEK WITH ZONAL FLOW TO WEAK RIDGING ALOFT AND BROAD SOUTH TO SOUTHWEST FLOW NEAR THE SURFACE. CANNOT RULE OUT ISOLATED AFTERNOON THUNDERSTORMS UNDER THIS REGIME TUESDAY AND WEDNESDAY...ALTHOUGH CAPPING MAY BE A HINDRANCE...OTHERWISE EXPECT MAINLY DRY CONDITIONS EARLY WEEK. THINGS DO TRANSITION LATE WEEK WITH A MORE POTENT UPPER WAVE AND SURFACE SYSTEM MOVING THROUGH THE AREA WEDNESDAY NIGHT INTO EARLY FRIDAY. HIGHER POPS WILL BE NECESSARY HERE. ON TEMPS...ALLBLEND INITIALIZATION WAS REASONABLE...ALTHOUGH DID BUMP HIGHS UP A DEGREE IN SOME PERIODS TO ACCOUNT FOR POTENTIAL IMPACT OF OVERDONE PRECIP IN MODELS. MAXES/MINS WILL BE NEAR TO A BIT ABOVE CLIMO UNTIL VERY LATE IN THE PERIOD POST COLD FRONT...AS THE ZONAL TO WEAKLY ANTICYCLONIC PATTERN WOULD DICTATE. && .AVIATION /DISCUSSION FOR THE 22/06Z TAFS/... ISSUED AT 1213 AM EDT SAT JUN 22 2013 EXPECT MOSTLY VFR CONDITIONS EXCEPT PERHAPS SOME BRIEF OVERNIGHT FOG TONIGHT AT LAF AND MORESO AT HUF WHERE OVER AN INCH OF RAIN FELL LAST EVENING. HOWEVER...THINK THERE IS A BETTER CHANCE THAT CONVECTIVE DEBRIS CLOUDS WILL BE SUFFICIENT TO KEEP THE VISIBILITY P6SM ESPECIALLY AT LAF. COULD SEE A FEW MORE AFTERNOON STORMS MAINLY AFTER 16Z...BUT CHANCES TOO SMALL TO MENTION. DID GO WITH A BROKEN VFR CU DECK THOUGH TO STRESS CONVECTIVE POSSIBILITY. SOUTH AND SOUTHWEST 7 KNOTS OR LESS TONIGHT WILL INCREASE TO AROUND 10 KNOTS FROM THE SOUTHWEST AFTER 16Z SATURDAY AND BECOME LIGHT TO CALM AFTER 02Z SUNDAY. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...SMF NEAR TERM...SMF SHORT TERM...SMF LONG TERM....NIELD AVIATION...MK VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
310 AM EDT SAT JUN 22 2013 .UPDATE... THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 307 AM EDT SAT JUN 22 2013 POTENTIAL EXISTS FOR OCCASIONAL UPPER DISTURBANCES...RIDING ALONG THE EDGE OF AN UPPER RIDGE...TO AFFECT CENTRAL INDIANA INTO THE MIDDLE OF NEXT WEEK. BY NEXT THURSDAY AND FRIDAY...A COLD FRONT MAY MOVE INTO THE AREA. && .NEAR TERM /TODAY/... ISSUED AT 307 AM EDT SAT JUN 22 2013 CONFIDENCE IS LOW IN THE THUNDERSTORM FORECAST FOR THIS WEEKEND. NONE OF THE MODELS APPEAR TO HAVE A HANDLE ON THE MCS CURRENTLY OVER MN AND WI. THE HRRR MAY BE THE ONLY MODEL TO PROVIDE SOME TRUTH TO WHAT WILL PREVAIL FOR LATER TODAY...AND THAT IS THE POTENTIAL FOR REMNANT MCS ACTIVITY TO EVENTUALLY WORK IT/S WAY SOUTH TO CENTRAL INDIANA BY THIS AFTERNOON AND EARLY EVENING. INCREASED POP COVERAGE TO INCLUDE THE ENTIRE CWA...WITH SLIGHTLY HIGHER CHANCE POPS ACROSS THE NORTHERN TIER WHERE ANY REMNANT ACTIVITY IS MOSTLY LIKELY TO REACH. IF THIS ACTIVITY DOES REACH CENTRAL INDIANA BY THIS AFTERNOON THEN TEMPERATURES WILL BE AFFECTED. SINCE CONFIDENCE IS LOW AT THIS JUNCTURE WILL CONTINUE WITH PERSISTENCE AND WARM HIGHS IN THE UPPER 80S TO AROUND 90. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... ISSUED AT 307 AM EDT SAT JUN 22 2013 SLIGHT CHANCE TO LOW CHANCE POPS WILL CONTINUE THIS EVENING AND THEN BY 06Z BE DRY. LOWS AROUND 70. SUNDAY AND MONDAY WILL BRING WITH IT SIMILAR CHALLENGES TO THE THUNDERSTORM FORECAST AS A FEW UPPER LEVEL DISTURBANCES ARE FORECAST TO MOVE THROUGH. INTRODUCED AT LEAST A SLIGHT CHANCE POP FOR SUNDAY AFTERNOON...AND AGAIN MONDAY AND MONDAY NIGHT. THE OTHER STORY THROUGH AT LEAST MID WEEK WILL BE THE SEASONABLY WARM TEMPERATURES WITH HIGHS REACHING AROUND THE 90 MARK. DID NOT STRAY FAR FROM MOS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ISSUED AT 242 PM EDT FRI JUN 21 2013 SUMMER TIME PATTERN WILL BE IN PLACE FOR THE BEGINNING OF LONG TERM PERIOD. WEAK RIDGING ALOFT AND SOUTH/SOUTHWEST FLOW AT THE SURFACE WILL BE CONDUCIVE TO PERIODS OF DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS. HOWEVER...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE LATER IN THE WEEK /MAINLY THURSDAY/ AS AN UPPER LEVEL LOW TRAVERSES ONTARIO...AND ITS TRAILING COLD FRONT SWEEPS ACROSS CENTRAL INDIANA. TEMPS...FELT THAT LATEST INITIALIZATION WAS ON THE COOL SIDE FOR WARM SOUTHWEST FLOW AT THE SURFACE ON TUESDAY AND WEDNESDAY. AS A RESULT...TRENDED 1 TO 3 DEGREES ABOVE GUIDANCE FOR DAYTIME HIGHS ON THOSE DAYS. OTHERWISE...WAS ABLE TO STICK CLOSE TO ALLBLEND INITIALIZATION NUMBERS FOR THE REMAINDER OF THE EXTENDED PERIOD. && .AVIATION /DISCUSSION FOR THE 22/06Z TAFS/... ISSUED AT 1213 AM EDT SAT JUN 22 2013 EXPECT MOSTLY VFR CONDITIONS EXCEPT PERHAPS SOME BRIEF OVERNIGHT FOG TONIGHT AT LAF AND MORESO AT HUF WHERE OVER AN INCH OF RAIN FELL LAST EVENING. HOWEVER...THINK THERE IS A BETTER CHANCE THAT CONVECTIVE DEBRIS CLOUDS WILL BE SUFFICIENT TO KEEP THE VISIBILITY P6SM ESPECIALLY AT LAF. COULD SEE A FEW MORE AFTERNOON STORMS MAINLY AFTER 16Z...BUT CHANCES TOO SMALL TO MENTION. DID GO WITH A BROKEN VFR CU DECK THOUGH TO STRESS CONVECTIVE POSSIBILITY. SOUTH AND SOUTHWEST 7 KNOTS OR LESS TONIGHT WILL INCREASE TO AROUND 10 KNOTS FROM THE SOUTHWEST AFTER 16Z SATURDAY AND BECOME LIGHT TO CALM AFTER 02Z SUNDAY. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SMF NEAR TERM...SMF SHORT TERM...SMF LONG TERM....TDUD AVIATION...MK VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS WICHITA KS
306 PM CDT SAT JUN 22 2013 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 306 PM CDT SAT JUN 22 2013 FORECAST HIGHLIGHTS FOCUS AROUND HOT AND WINDY WEATHER CONTINUING THROUGH MID WEEK...THUNDERSTORM CHANCES LATE SUN AFTERNOON-NIGHT OVER CENTRAL KS AND AGAIN THU-THU NIGHT AREAWIDE...AND A COOLING TREND BY LATE WEEK/NEXT WEEKEND. APPROACHING SHORTWAVE ENERGY SHOULD INITIATE A FEW THUNDERSTORMS OVER WESTERN KS LATE THIS AFTERNOON ALONG A SHARPENING DRYLINE. LAST 3 RUNS OF THE HRRR HAVE ALLUDED TO THIS. NOT OUT OF THE REALM OF POSSIBILITY THAT SOME OF THIS ACTIVITY COULD GET INTO RUSSELL AND BARTON COUNTIES BETWEEN 8 PM AND MIDNIGHT. HOWEVER...SUSPECT WEAK FORCING IN CONCERT WITH WARM MID-LEVEL TEMPERATURES/INCREASING CINH WILL LIKELY DISSIPATE THIS ACTIVITY BEFORE REACHING WESTERN CORRIDOR. ADDITIONAL ACTIVITY WILL LIKELY AFFECT NEBRASKA AND POSSIBLY FAR NORTHERN KS OVERNIGHT...BUT WILL LIKELY REMAIN NORTH OF THE FORECAST AREA. OTHERWISE...SHORTWAVE ENERGY PROGRESSING ACROSS THE NORTHERN PLAINS WILL ALLOW A COLD FRONT TO APPROACH CENTRAL KS SUNDAY. THE INCREASED CONVERGENCE AT PEAK HEATING COULD ALLOW A FEW ISOLATED STORMS TO FIRE ALONG THE FRONT SUNDAY LATE AFTERNOON...POSSIBLY AFFECTING LOCATIONS NORTH OF A GREAT BEND-SALINA LINE. HOWEVER...GIVEN WEAK FORCING AT PEAK HEATING...THINKING THE MORE PROBABLE SCENARIO IS CLUSTER OF THUNDERSTORMS DEVELOPING OVER NORTHWEST KS/SOUTHWEST NE AND PROPAGATING EAST/SOUTHEAST INTO CENTRAL KS AFTER DARK. GIVEN NAM`S PLACEMENT OF FRONT...THINKING LOCATIONS NORTH OF GREAT BEND-SALINA HAVE A DECENT CHANCE OF SEEING MOISTURE...ALONG WITH POTENTIAL FOR A STRONG/SEVERE FORWARD PROPAGATING MCS CARRYING AN ISOLATED DAMAGING WIND THREAT. FRONT LIFTS NORTH FOR MON-TUE...EFFECTIVELY SHUTTING DOWN PRECIPITATION CHANCES AND CONTINUING THE WINDY AND HOT WEATHER. WINDS WILL LIKELY FLIRT WITH WIND ADVISORY CRITERIA ONCE AGAIN SUN AND MON...AND POSSIBLY TUE AS WELL. FURTHERMORE...PER THE GFS...CANNOT COMPLETELY RULE OUT A STRAY THUNDERSTORMS GETTING INTO RUSSELL/BARTON COUNTIES TUE EVENING...BUT ONCE AGAIN SUSPECT BETTER CHANCES WILL REMAIN WEST/NORTHWEST. ADK && .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 306 PM CDT SAT JUN 22 2013 THE UPPER RIDGE IS PROGGED TO BUILD IN EARNEST ACROSS THE WESTERN CONUS LATE NEXT WEEK. THE HIGHER AMPLITUDE FLOW REGIME WILL EVENTUALLY ALLOW A SIGNIFICANT UPPER TROF TO DROP SOUTHEAST ACROSS THE GREAT LAKES WHICH WILL DEVELOP INTO AN EASTERN CONUS LONGWAVE BY NEXT WEEKEND. THE RESULT FOR KANSAS WILL BE A CONTINUATION OF THE BREEZY AND HOT WEATHER THROUGH MID-WEEK WITH A COLD FRONTAL PASSAGE AND SOMEWHAT COOLER OR LESS HOT CONDITIONS BY FRIDAY/SATURDAY. LATEST PROGGED LOW LEVEL THICKNESS VALUES/THERMAL FIELDS WOULD SUPPORT HOTTER MAXS AHEAD OF THE FRONTAL PASSAGE FOR WEDNESDAY AND THURSDAY...WITH MAXS AT OR ABOVE THE CENTURY MARK FOR LOCATIONS ALONG/WEST OF I-135. THE GFS LATEST FRONTAL TIMING COULD ALLOW FOR A VERY HOT BUBBLE OF COMPRESSED AIR ON THE WESTERLY COMPONENT FLOW ACROSS MUCH OF SOUTHERN KANSAS ON THURSDAY AFTERNOON. SO FOR NOW HAVE MADE A SLIGHT UP-TWEAK TO THE LOADED INITIALIZATION WHICH IS ALSO ABOVE GMOS VALUES. WILL CONTINUE TO CARRY SLIGHT CHANCE POPS THURSDAY INTO EARLY FRIDAY...THOUGH FORCING REMAINS RATHER WEAK AND LIKELY TIED TO FRONTAL CONVERGENCE AND MAINLY DIURNALLY DRIVEN CONVECTION WITH CARRYOVER INTO THURSDAY NIGHT EARLY FRIDAY MORNING. DARMOFAL && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1213 PM CDT SAT JUN 22 2013 VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. ONLY AVIATION CONCERN WILL BE GUSTY WINDS THIS AFTERNOON AND INTO THE EVENING. WINDS FROM A SOUTHERLY DIRECTION AT SPEEDS IN A 30 TO 35 MPH RANGE CAN BE EXPECTED WITH GUSTS TO NEAR 40 MPH AT RSL...GBD...HUT...SLN...ICT...AND AAO. CHANCE && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 75 96 74 95 / 10 10 10 10 HUTCHINSON 75 98 74 97 / 10 10 20 10 NEWTON 74 96 74 95 / 10 10 10 10 ELDORADO 74 93 74 93 / 0 0 10 10 WINFIELD-KWLD 75 94 74 94 / 0 0 10 10 RUSSELL 75 99 70 98 / 10 20 40 10 GREAT BEND 75 100 71 98 / 10 10 30 10 SALINA 75 98 72 97 / 10 10 40 10 MCPHERSON 75 98 74 96 / 10 10 20 10 COFFEYVILLE 75 92 74 92 / 10 0 10 10 CHANUTE 74 92 74 91 / 10 0 10 10 IOLA 74 92 74 91 / 10 0 10 10 PARSONS-KPPF 75 92 74 91 / 10 0 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ032-033-047-048- 050-067-082-091. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
1241 PM CDT SAT JUN 22 2013 .UPDATE... ISSUED AT 1233 PM CDT SAT JUN 22 2013 UPDATED THE AFTERNOON GRIDS TO REMOVE THUNDER AND EVENTUALLY END ALL PRECIP BY AROUND 19Z. TEMPERATURES...WINDS AND HEAT INDICES NORTH CENTRAL ALTHOUGH DELAYED...STILL EXPECTED TO RECOVER THROUGH THE MIDDLE AND LATE AFTERNOON HOURS. WILL LIKELY NEED ANOTHER UPDATE IN THE NEXT ONE TO TWO HOURS TO REMOVE ALL MENTION OF PRECIP. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 343 AM CDT SAT JUN 22 2013 LARGE COMPLEX OF RAIN AND THUNDERSTORMS CONTINUES TO MARCH EASTWARD ACROSS MUCH OF NORTH AND EAST NEBRASKA AND POINTS NE. SOUTHERN PROGRESS OF THE OUTFLOW HAS SLOWED SOMEWHAT THE PAST HOUR OR SO. SHORTWAVE TROF NOTED IN WV IMAGERY OVER EASTERN KS ATTM...BUT IS PRODUCING ONLY CLOUDS SO FAR AS IT PASSES. EVENING SOUNDING AT TOP SHOWED STEEP LAPSE RATES IN THE 750 TO 550 MB LAYER...HOWEVER CAP IS STRONG BELOW 700MB AND COLUMN IS DRY THROUGH ABOUT 400MB. ONLY GUIDANCE THAT SUGGESTS PRECIP THIS MORNING HAS BEEN OUT WEST WITH THE HRRR FOR SEVERAL RUNS...ALL OTHERS REMAIN DRY. WILL CARRY A SILENT POP WEST OF MANHATTAN FOR A FEW HOURS THIS MORNING. COULD GET A BRIEF BREAK NORTH FROM SOME OF THE OUTFLOW FROM THE NORTH...BUT EXPECT THAT WOULD BE SHORT LIVED. HIGHS STILL EXPECTED INTO THE LOWER TO MIDDLE 90S WITH HEAT INDICES RUNNING AROUND 100 ALONG THE KS RIVER VALLEY. WINDS BECOME QUITE BREEZY OUT OF THE SOUTH AS YOU GO WESTWARD...WITH SUSTAINED AFTERNOON WINDS AROUND 30 WITH GUSTS 35-40 POSSIBLE. WILL MONITOR TRENDS FOR WIND ADVISORY BUT IS BORDERLINE AT THIS TIME. OVERNIGHT LOWS EXPECTED ON THE WARM SIDE AGAIN IN THE MIDDLE 70S. 67 .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 343 AM CDT SAT JUN 22 2013 MID RANGE AND EXTENDED FORECAST (SUNDAY THROUGH FRIDAY)... VERY LITTLE CHANGE IN THIS FORECAST PACKAGE AS MODELS ARE STILL CONSISTENT IN SHOWING A LARGE SCALE RIDGING PATTERN ACROSS THE SOUTHEASTERN PORTION OF THE CONUS THROUGH THE WEEKEND...WITH A PACIFIC TROUGH OVER THE WEST COAST. LIGHT SOUTHWEST FLOW WILL BE PRESENT OVER THE ROCKY MOUNTAINS UP THROUGH THE NORTHERN PLAINS...WITH THE CENTRAL PLAINS BEING ON THE EASTERN FRINGE OF THE BETTER FLOW. EXPECT WARM TEMPERATURES TO CONTINUE FOR SUNDAY...WITH A PRETTY DECENT CHANCE FOR RAIN SUNDAY NIGHT AS A DISTURBANCE WITHIN THE SOUTHWESTERLY FLOW ALOFT WILL TRIGGER A ROUND OF THUNDERSTORMS ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS. THE BEST CHANCE FOR RAIN WILL BE ALONG THE KS/NE BORDER...WITH DECREASING CHANCES FURTHER SOUTH ALONG INTERSTATE 70. EXPECT LITTLE IN THE WAY OF CONVECTIVE CHANCES AFTER THE SUNDAY NIGHT ROUND OF THUNDERSTORMS. ECMWF HAS BEEN CONSISTENT IN PREDICTING THE FOUR CORNERS MID LEVEL RIDGE TO SET UP BY MID WEEK...WHICH WILL KEEP TEMPERATURES IN THE AREA WARM THROUGH THE EXTENDED PERIOD. TEMPERATURES GENERALLY WILL REMAIN IN THE LOWER TO MID 90S ACROSS EASTERN KANSAS THROUGH THE EXTENDED PERIOD...WITH TEMPS REACHING THE MID TO UPPER 90S IN WESTERN KANSAS. THE NEXT CHANCES FOR RAIN WILL BE RATHER MINIMAL AS A BOUNDARY LOOKS TO SLIDE INTO THE AREA IN THE THURSDAY/FRIDAY TIME FRAME. THIS BOUNDARY WOULD BE THE FOCUS FOR ANY POTENTIAL CONVECTION DURING THAT TIME PERIOD. MADE VIRTUALLY NO CHANGE TO THE FORECAST FOR THE LATE PART OF THE WEEK FOR THESE POTENTIAL SHOWERS. JL && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1233 PM CDT SAT JUN 22 2013 VFR CONDITIONS WILL PERSIST THROUGH THE PERIOD AS THIS AFTERNOONS CONVECTION/SHOWERS TO THE WEST OF THE TERMINALS DISSIPATES AND TONIGHTS CONVECTION REMAINS NORTH AND WEST OF THE TERMINALS AS WELL THROUGH THE PERIOD. GUSTY SOUTH WINDS THIS AFTERNOON WILL DECREASE TO 11-14KTS AFT 02Z...BEFORE INCREASING AGAIN AFT 14Z. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...63 SHORT TERM...CRAVEN LONG TERM...LEIGHTON AVIATION...63
AREA FORECAST DISCUSSION
NWS TOPEKA KS
618 AM CDT SAT JUN 22 2013 UPDATED FOR AVIATION. .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 343 AM CDT SAT JUN 22 2013 LARGE COMPLEX OF RAIN AND THUNDERSTORMS CONTINUES TO MARCH EASTWARD ACROSS MUCH OF NORTH AND EAST NEBRASKA AND POINTS NE. SOUTHERN PROGRESS OF THE OUTFLOW HAS SLOWED SOMEWHAT THE PAST HOUR OR SO. SHORTWAVE TROF NOTED IN WV IMAGERY OVER EASTERN KS ATTM...BUT IS PRODUCING ONLY CLOUDS SO FAR AS IT PASSES. EVENING SOUNDING AT TOP SHOWED STEEP LAPSE RATES IN THE 750 TO 550 MB LAYER...HOWEVER CAP IS STRONG BELOW 700MB AND COLUMN IS DRY THROUGH ABOUT 400MB. ONLY GUIDANCE THAT SUGGESTS PRECIP THIS MORNING HAS BEEN OUT WEST WITH THE HRRR FOR SEVERAL RUNS...ALL OTHERS REMAIN DRY. WILL CARRY A SILENT POP WEST OF MANHATTAN FOR A FEW HOURS THIS MORNING. COULD GET A BRIEF BREAK NORTH FROM SOME OF THE OUTFLOW FROM THE NORTH...BUT EXPECT THAT WOULD BE SHORT LIVED. HIGHS STILL EXPECTED INTO THE LOWER TO MIDDLE 90S WITH HEAT INDICES RUNNING AROUND 100 ALONG THE KS RIVER VALLEY. WINDS BECOME QUITE BREEZY OUT OF THE SOUTH AS YOU GO WESTWARD...WITH SUSTAINED AFTERNOON WINDS AROUND 30 WITH GUSTS 35-40 POSSIBLE. WILL MONITOR TRENDS FOR WIND ADVISORY BUT IS BORDERLINE AT THIS TIME. OVERNIGHT LOWS EXPECTED ON THE WARM SIDE AGAIN IN THE MIDDLE 70S. 67 .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 343 AM CDT SAT JUN 22 2013 MID RANGE AND EXTENDED FORECAST (SUNDAY THROUGH FRIDAY)... VERY LITTLE CHANGE IN THIS FORECAST PACKAGE AS MODELS ARE STILL CONSISTENT IN SHOWING A LARGE SCALE RIDGING PATTERN ACROSS THE SOUTHEASTERN PORTION OF THE CONUS THROUGH THE WEEKEND...WITH A PACIFIC TROUGH OVER THE WEST COAST. LIGHT SOUTHWEST FLOW WILL BE PRESENT OVER THE ROCKY MOUNTAINS UP THROUGH THE NORTHERN PLAINS...WITH THE CENTRAL PLAINS BEING ON THE EASTERN FRINGE OF THE BETTER FLOW. EXPECT WARM TEMPERATURES TO CONTINUE FOR SUNDAY...WITH A PRETTY DECENT CHANCE FOR RAIN SUNDAY NIGHT AS A DISTURBANCE WITHIN THE SOUTHWESTERLY FLOW ALOFT WILL TRIGGER A ROUND OF THUNDERSTORMS ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS. THE BEST CHANCE FOR RAIN WILL BE ALONG THE KS/NE BORDER...WITH DECREASING CHANCES FURTHER SOUTH ALONG INTERSTATE 70. EXPECT LITTLE IN THE WAY OF CONVECTIVE CHANCES AFTER THE SUNDAY NIGHT ROUND OF THUNDERSTORMS. ECMWF HAS BEEN CONSISTENT IN PREDICTING THE FOUR CORNERS MID LEVEL RIDGE TO SET UP BY MID WEEK...WHICH WILL KEEP TEMPERATURES IN THE AREA WARM THROUGH THE EXTENDED PERIOD. TEMPERATURES GENERALLY WILL REMAIN IN THE LOWER TO MID 90S ACROSS EASTERN KANSAS THROUGH THE EXTENDED PERIOD...WITH TEMPS REACHING THE MID TO UPPER 90S IN WESTERN KANSAS. THE NEXT CHANCES FOR RAIN WILL BE RATHER MINIMAL AS A BOUNDARY LOOKS TO SLIDE INTO THE AREA IN THE THURSDAY/FRIDAY TIME FRAME. THIS BOUNDARY WOULD BE THE FOCUS FOR ANY POTENTIAL CONVECTION DURING THAT TIME PERIOD. MADE VIRTUALLY NO CHANGE TO THE FORECAST FOR THE LATE PART OF THE WEEK FOR THESE POTENTIAL SHOWERS. JL && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 616 AM CDT SAT JUN 22 2013 VFR CONDITIONS EXPECTED FOR THE PERIOD. SOUTHERLY WINDS INCREASE THROUGHOUT THE DAY. CLOUDS GENERALLY AOA 15KFT...WITH NEXT CHANCE FOR THUNDERSTORMS TOWARD THE NEBRASKA BORDER LATE IN THE PERIOD. 67 && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CRAVEN LONG TERM...LEIGHTON AVIATION...67
AREA FORECAST DISCUSSION
NWS TOPEKA KS
355 AM CDT SAT JUN 22 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 343 AM CDT SAT JUN 22 2013 LARGE COMPLEX OF RAIN AND THUNDERSTORMS CONTINUES TO MARCH EASTWARD ACROSS MUCH OF NORTH AND EAST NEBRASKA AND POINTS NE. SOUTHERN PROGRESS OF THE OUTFLOW HAS SLOWED SOMEWHAT THE PAST HOUR OR SO. SHORTWAVE TROF NOTED IN WV IMAGERY OVER EASTERN KS ATTM...BUT IS PRODUCING ONLY CLOUDS SO FAR AS IT PASSES. EVENING SOUNDING AT TOP SHOWED STEEP LAPSE RATES IN THE 750 TO 550 MB LAYER...HOWEVER CAP IS STRONG BELOW 700MB AND COLUMN IS DRY THROUGH ABOUT 400MB. ONLY GUIDANCE THAT SUGGESTS PRECIP THIS MORNING HAS BEEN OUT WEST WITH THE HRRR FOR SEVERAL RUNS...ALL OTHERS REMAIN DRY. WILL CARRY A SILENT POP WEST OF MANHATTAN FOR A FEW HOURS THIS MORNING. COULD GET A BRIEF BREAK NORTH FROM SOME OF THE OUTFLOW FROM THE NORTH...BUT EXPECT THAT WOULD BE SHORT LIVED. HIGHS STILL EXPECTED INTO THE LOWER TO MIDDLE 90S WITH HEAT INDICES RUNNING AROUND 100 ALONG THE KS RIVER VALLEY. WINDS BECOME QUITE BREEZY OUT OF THE SOUTH AS YOU GO WESTWARD...WITH SUSTAINED AFTERNOON WINDS AROUND 30 WITH GUSTS 35-40 POSSIBLE. WILL MONITOR TRENDS FOR WIND ADVISORY BUT IS BORDERLINE AT THIS TIME. OVERNIGHT LOWS EXPECTED ON THE WARM SIDE AGAIN IN THE MIDDLE 70S. 67 .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 343 AM CDT SAT JUN 22 2013 MID RANGE AND EXTENDED FORECAST (SUNDAY THROUGH FRIDAY)... VERY LITTLE CHANGE IN THIS FORECAST PACKAGE AS MODELS ARE STILL CONSISTENT IN SHOWING A LARGE SCALE RIDGING PATTERN ACROSS THE SOUTHEASTERN PORTION OF THE CONUS THROUGH THE WEEKEND...WITH A PACIFIC TROUGH OVER THE WEST COAST. LIGHT SOUTHWEST FLOW WILL BE PRESENT OVER THE ROCKY MOUNTAINS UP THROUGH THE NORTHERN PLAINS...WITH THE CENTRAL PLAINS BEING ON THE EASTERN FRINGE OF THE BETTER FLOW. EXPECT WARM TEMPERATURES TO CONTINUE FOR SUNDAY...WITH A PRETTY DECENT CHANCE FOR RAIN SUNDAY NIGHT AS A DISTURBANCE WITHIN THE SOUTHWESTERLY FLOW ALOFT WILL TRIGGER A ROUND OF THUNDERSTORMS ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS. THE BEST CHANCE FOR RAIN WILL BE ALONG THE KS/NE BORDER...WITH DECREASING CHANCES FURTHER SOUTH ALONG INTERSTATE 70. EXPECT LITTLE IN THE WAY OF CONVECTIVE CHANCES AFTER THE SUNDAY NIGHT ROUND OF THUNDERSTORMS. ECMWF HAS BEEN CONSISTENT IN PREDICTING THE FOUR CORNERS MID LEVEL RIDGE TO SET UP BY MID WEEK...WHICH WILL KEEP TEMPERATURES IN THE AREA WARM THROUGH THE EXTENDED PERIOD. TEMPERATURES GENERALLY WILL REMAIN IN THE LOWER TO MID 90S ACROSS EASTERN KANSAS THROUGH THE EXTENDED PERIOD...WITH TEMPS REACHING THE MID TO UPPER 90S IN WESTERN KANSAS. THE NEXT CHANCES FOR RAIN WILL BE RATHER MINIMAL AS A BOUNDARY LOOKS TO SLIDE INTO THE AREA IN THE THURSDAY/FRIDAY TIME FRAME. THIS BOUNDARY WOULD BE THE FOCUS FOR ANY POTENTIAL CONVECTION DURING THAT TIME PERIOD. MADE VIRTUALLY NO CHANGE TO THE FORECAST FOR THE LATE PART OF THE WEEK FOR THESE POTENTIAL SHOWERS. JL && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1128 PM CDT FRI JUN 21 2013 VFR CONDITIONS AS SCT TO BKN CIRRUS CLOUDS SKIRT ACROSS KTOP/KFOE/KMHK. EXPECT GRADIENT TO RELAX SLIGHTLY WITH OVERNIGHT SOUTH WINDS AROUND 10 KTS AT KTOP/KFOE. KMHK SHOULD STAY UP NEAR 12 KTS. WIND DIRECTION BACKS SLIGHTLY TO THE SOUTH AT SITES...INCREASING BETWEEN 15-20 KTS WITH GUSTS 25-30 KTS AFT 14Z. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CRAVEN LONG TERM...LEIGHTON AVIATION...BOWEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1154 PM MDT FRI JUN 21 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 216 PM MDT FRI JUN 21 2013 AS OF 3 PM CDT...2 PM MDT...SKIES ACROSS THE TRI-STATE WERE CLEAR ALBEIT A LITTLE HAZY FROM SMOKE THAT CONTINUES TO STREAM IN FROM FIRES IN SOUTH CENTRAL COLORADO. SOME CUMULUS AND TOWERING CUMULUS COULD BE SEEN ON VISIBLE SATELLITE IMAGERY JUST NORTH OF AKRON...COLORADO. SOUTH WINDS HAVE PICKED UP MAINLY EAST OF A LINE FROM TRENTON...NEBRASKA TO COLBY AND LEOTI KANSAS AS A SURFACE LOW PRESSURE SYSTEM DEEPENS TO THE WEST. TEMPERATURES RANGED FROM THE LOW 90S IN EAST COLORADO TO NEAR 100 ACROSS SOME PARTS OF KANSAS AND SOUTHWEST NEBRASKA. VERY DRY AIR WAS ALSO STARTING TO MOVE IN FROM THE SOUTHWEST. SIMILAR TO YESTERDAY...ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG A DRYLINE. SURFACE CONVERGENCE IS BEGINNING TO APPEAR IN THE SURFACE WIND FIELD ALONG THE DRYLINE WHICH WILL BE THE FOCUS OF STORM DEVELOPMENT. THE HRRR AND NAM MODELS SUGGEST STORM INITIATION WILL OCCUR IN FAR WESTERN KANSAS. STORMS SHOULD BE CONFINED MAINLY ALONG AND EAST OF A LINE FROM YUMA COLORADO TO GOODLAND KANSAS TO TRIBUNE KANSAS AND WEST OF A LINE FROM MCCOOK NEBRASKA TO RUSSELL SPRINGS KANSAS. ANY STORM THAT IS ABLE TO DEVELOP WILL BE STRONG TO SEVERE WITH LARGE HAIL AND DAMAGING WINDS AS THE MAIN THREATS. FOR TONIGHT...GUSTY WINDS WILL CONTINUE A LOW LEVEL JET DEVELOPS OVER THE EASTERN HALF. WINDS SHOULD BE BELOW WIND ADVISORY CRITERIA WITH THE STRONGEST WINDS REMAINING TO THE SOUTH OVER SOUTHWEST AND SOUTH CENTRAL KANSAS. LOWS WILL STRUGGLE TO FALL TONIGHT WITH THE ATMOSPHERE IN A MIXED STATE SO HAVE GONE ABOVE GUIDANCE FOR LOWS. TONIGHTS TEMPERATURE FORECAST IS VERY SIMILAR TO WHAT ACTUALLY OCCURRED LAST NIGHT. FOR TOMORROW...A REPEAT OF TODAY IS EXPECTED FOR THE MOST PART. TEMPERATURES ARE NOT EXPECTED TO BE AS HOT AS TODAY WITH HIGHS ONLY REACHING THE MID TO UPPER 90S WITH A FEW SPOTS REACHING 100. A WEAK FRONT WILL MOVE INTO THE AREA FROM THE NORTH...RESULTING IN MAINLY A WIND SHIFT WITH EVER SO SLIGHTLY COOLER TEMPERATURES. WITH A DRYLINE STILL IN PLACE...ISOLATED THUNDERSTORMS ARE POSSIBLE AGAIN FOR TOMORROW. ANY STORMS THAT ARE ABLE TO DEVELOP WOULD LIKELY BECOME SEVERE. THERE IS A SLIGHT RISK FOR SEVERE WEATHER ACROSS SOUTHWEST NEBRASKA TOMORROW AND THAT SEEMS REASONABLE GIVEN THE LOCATION OF THE FRONT TOMORROW. THE FRONT SHOULD PROVIDE A BETTER FOCUS FOR THUNDERSTORM DEVELOPMENT OVER THE NORTHERN THIRD OF THE FORECAST AREA. GUSTY SOUTH WINDS ARE EXPECTED AGAIN WITH A LOW PRESSURE DEEPENING TO THE WEST. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 215 PM MDT FRI JUN 21 2013 A SIGNIFICANT CHANGE IN THE UPPER PATTERN WILL TAKE PLACE DURING THIS EXTENDED PERIOD. THE CURRENT SOUTHWEST FLOW ALOFT ACCOMPANIED BY NUMEROUS MINOR DISTURBANCES WILL TRANSITION TO A BUILDING UPPER RIDGE...STARTING OVER NM/AZ TUESDAY AND ULTIMATELY ENCOMPASSING ALL OF THE CENTRAL ROCKIES BY THE END OF THE WEEK. THERE STILL LOOKS TO BE A COUPLE OF OPPORTUNITIES FOR STORMS COMING OUT OF COLORADO AND MOVING ACROSS THE CWA SATURDAY AND SUNDAY EVENING AS WEAK SHORT WAVE TROUGHS MOVE THROUGH THE FLOW. AFTER THAT...PRECIP POTENTIAL WILL DIMINISH AS THE UPPER RIDGE AND WARMING MID-LEVEL TEMPS BEGIN TO DOMINATE. TEMPERATURES ARE EXPECTED TO REMAIN WELL ABOVE NORMAL DURING THE PERIOD WITH HIGHS MOSTLY IN THE MIDDLE 90S TO NEAR 100 AND LOWS IN THE 60S TO NEAR 70. CURRENT EXTENDED GUIDANCE BEYOND THIS PERIOD SUGGESTS THE UPPER RIDGE WILL CONTINUE TO BUILD NORTH TOWARD IDAHO BY NEXT WEEKEND. IF THAT PANS OUT...THE UPPER FLOW WILL BECOME NORTHWEST OVER THE CWA POSSIBLY INCREASING THE CHANCE FOR LATE DAY STORMS MOVING SOUTHEAST OFF THE CHEYENNE RIDGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1148 PM MDT FRI JUN 21 2013 CONDITIONS AT MCK AND GLD WILL CONTINUE TO BE VFR THROUGH THE TAF PERIOD. OUTFLOW FROM THUNDERSTORMS OVER CENTRAL SOUTHERN NEBRASKA REINFORCING THE COLDFRONTAL BOUNDARY WILL CONTINUE TO AFFECT THE WINDS AT MCK...KEEPING THEM GENERALLY LIGHT OUT OF THE NORTHEAST TO EAST OVERNIGHT. WINDS AT MCK WILL TURN SOUTH AND BECOME GUSTY DURING THE AFTERNOON AS THE FRONT MOVES NORTHWARD. GUSTY SOUTH WINDS AT GLD WILL SLACKEN SOMEWHAT TOWARDS SUNRISE...BUT WILL RETURN BY AFTERNOON. THERE IS A POSSIBILITY OF ISOLATED THUNDERSTORMS DEVELOPING ACROSS THE CENTRAL HIGH PLAINS REGION DURING THE AFTERNOON AND EVENING...BUT THE CHANCE OF ANY STORM MOVING OVER EITHER TAF SITE IS SLIM ENOUGH THAT ANY MENTION OF STORMS HAS BEEN LEFT OUT. && .FIRE WEATHER... ISSUED AT 216 PM MDT FRI JUN 21 2013 CRITICAL FIRE WEATHER CONDITIONS ARE DEVELOPING TO THE SOUTHWEST...MAINLY OVER GREELEY AND WALLACE COUNTIES KANSAS AND CHEYENNE AND KIT CARSON COUNTIES IN COLORADO. EVEN THOUGH RED FLAG CRITERIA WILL BE MET FOR THESE LOCATIONS TODAY FOR WIND AND RELATIVE HUMIDITY...RECENT RAINFALL AND HIGHER FUEL MOISTURE CONTENT ARE PREVENTING EXPLOSIVE FIRE WEATHER CONDITIONS FROM BECOMING A PROBLEM. THEREFORE...HAVE OPTED NOT TO ISSUE A RED FLAG WARNING. THE SAME STORY WILL REPEAT ITSELF AGAIN TOMORROW WITH LOW RELATIVE HUMIDITIES FILTERING IN FROM THE SOUTHWEST AND WINDS INCREASING BEHIND THE DRYLINE IN THE AFTERNOON. FUELS COULD BE MORE RIPE FOR FIRE POTENTIAL TOMORROW AFTER A COUPLE HOT DAYS WITH LITTLE RAINFALL BUT THINKING THAT FUEL MOISTURE WILL STILL BE HIGH ENOUGH THAT A RED FLAG WARNING WILL NOT BE WARRANTED. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...RRH LONG TERM...DLF AVIATION...LOCKHART FIRE WEATHER...RRH
AREA FORECAST DISCUSSION
NWS JACKSON KY
120 AM EDT SAT JUN 22 2013 .UPDATE... ISSUED AT 120 AM EDT SAT JUN 22 2013 CLUSTER OF SHOWERS/STORMS WHICH DROPPED SOME SMALL HAIL IN THE TRI- CITIES AREA OF NORTHEAST TENNESSEE EARLIER CONTINUES TO PINWHEEL WESTWARD. THESE SHOWERS/STORMS APPEAR DESTINED TO VISIT HARLAN AND BELL COUNTIES IN SOME SHAPE OR FORM AND WILL HOLD ONTO A 20 POP THROUGH THE REST OF THE NIGHT FOR THOSE AREAS. OTHERWISE...SHOWERS IN THE BLUEGRASS HAVE DIED OUT SO REMOVED ANY MENTION OF RAIN THERE. REST OF THE FORECAST IS ON TRACK... UPDATE ISSUED AT 900 PM EDT FRI JUN 21 2013 THUNDERSTORMS HAVE DIED DOWN IN OUR FORECAST AREA...BUT ISOLATED STORMS CONTINUE TO FIRE AROUND US. INHERITED FORECAST DROPPED ALL MENTION OF POPS AFTER 00Z EXCEPT DOWN SOUTH ALONG THE TN AND VA BORDERS AND KEPT WITH THIS THINKING. WILL NEED TO MONITOR THE STORMS FIRING OVER THE BLUEGRASS THOUGH TO MAKE SURE ADDITIONAL ACTIVITY DOESN/T FIRE ON OUTFLOWS INTO OUR BLUEGRASS COUNTIES. OTHERWISE... SHOULD BE A QUIET NIGHT WITH REPEAT VALLEY FOG DEVELOPMENT. FORECAST LOWS IN THE LOW TO MID 60S LOOK GOOD. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 314 PM EDT FRI JUN 21 2013 BEEN WATCHING THE MCS ENTERING NORTHERN ILL TO SEE HOW FAR SOUTH IT WILL KEEP GOING AND WHERE THE OUTFLOW BOUNDARIES END UP. CURRENT THINKING IS THAT IF IT DOES NOT FALL APART BEFORE IT REACHES THE AREA...IT SHOULD STAY WEST OF THE AREA. THE HRRR IS SHOWING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING DURING THE AFTERNOON AND EVENING HOURS. THE INSTABILITY IS THERE TO SUPPORT THUNDERSTORM DEVELOPMENT. ONE CONCERN IS THE DRY AIR IN THE MID LAYERS WHICH COULD HELP TO PRODUCE SOME STRONG OUTFLOW WINDS. THE OTHER CONCERN IS THAT THE WINDS ALOFT ARE SO LIGHT...THE STORMS WILL BE MOVING VERY SLOWLY. THIS MAY ALLOW A LOT OF PRECIPITATION TO FALL OVER A SMALL AREA AND COULD RESULT IN DITCHES AND LOW WATER CROSSINGS TO RUN FULL. THERE HAS ALREADY BEEN ONE STRONG STORM DEVELOP OVER LESLIE COUNTY THIS AFTERNOON. NO REPORTS OF ANY DAMAGE OR FLOODING WERE RECEIVED. A REPEAT OF THIS DIURNALLY BASED PULSE THUNDERSTORM ACTIVITY IS ANTICIPATED ON SATURDAY. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 314 PM EDT FRI JUN 21 2013 FAIRLY BUSY PATTERN FOR THE OFFICIAL START OF SUMMER. OVERALL MODELS ARE IN GOOD AGREEMENT THROUGH THE EXTENDED. IN FAIRLY HIGH AMPLITUDE FLOW...CORE WESTERLIES REMAINS NORTH OF OUR AREA UNTIL THE END OF THE FORECAST WINDOW. EASTERN CONUS RIDGING ALOFT RETREATS WESTWARD WITH TIME THROUGH THE PERIOD. EMBEDDED WITHIN THIS RIDGE EARLY ON IS AN AREA OF TROUGH-I-NE SS OR A CENTER OF RELATIVE LOWER HEIGHTS. THIS LOCALIZED AREA OF LOWER HEIGHTS WILL OPEN UP AND DRIFT NORTHEAST THROUGH THE LATTER PART OF THE WEEKEND AND EARLY NEXT WEEK...SPREADING ITS LIMITED INFLUENCE THROUGH THE SOUTHERN APPALACHIANS. FOR SUCH A WEAK FEATURE...CONSISTENT WITH THIS TIME OF YEAR...THE MODELS DO RATHER WELL IN DEPICTING SIMILAR EVOLUTIONS... THOUGH THE ECMWF MAINTAINS THE DISTINCT UPPER LOW LONGER THAN THE GFS. THIS RIDGING ACROSS THE REGION IS SUPPRESSED SOUTHWARD AS THIS AREA OF LOWER HEIGHTS GRADUALLY LIFTS NORTHWARD ACROSS EASTERN KENTUCKY SUNDAY. THEREAFTER THE RIDGE SHIFTS WESTWARD AND THE PATTERN AMPLIFIES...RESULTING IN ENERGY ALONG THE NORTHERN TIER SETTLING SOUTHWARD ALONG THE EASTERN SIDE OF THE RIDGE...EFFECTIVELY CARVING OUT A TROUGH OVER THE EASTERN CONUS TO FINISH OUT THE WEEK. SENSIBLE WEATHER WILL BE DOMINATED BY THE DIURNAL CYCLE THROUGH THE BULK OF THE EXTENDED AS SFC HIGH PRESSURE OVER THE AREA WILL BE TOO WEAK TO SUPPRESS ALL CONVECTION ONCE DAYTIME HEATING KICKS IN. THERE IS REALLY NO FEATURE TO KEY IN ON FOR MORE ORGANIZED...WIDESPREAD ACTIVITY THROUGH THE START OF THE UPCOMING WORK WEEK. THAT CHANGES TOWARDS WEEKS END AS A STORM SYSTEM DROPPING SOUTHWARD OUT OF CANADA HELPS TO GENERATE A BETTER CHANCE FOR RAIN ACROSS OUR AREA...THOUGH TIMING AND SPECIFICS REMAIN IN DOUBT. WARM AND SEASONABLE WEATHER IS THUS ON TAP FOR THE REST OF THE WEEKEND AND THROUGH THE START OF THE NEW WORK WEEK. DURING THE FIRST FEW DAYS OF THE EXTENDED...OUR BEST OPPORTUNITY FOR SOME GARDEN VARIETY...HIT AND MISS THUNDERSTORMS APPEARS TO BE SUNDAY AS HEIGHTS DROP SLIGHTLY DUE TO THE PASSING FEATURE...DISTURBANCE FROM THE SOUTH. ADDITIONAL CLOUD COVER...AND A BETTER POTENTIAL OF CONVECTION AFTER MID WEEK ON SHOULD HELP TEMPER THE WARMTH A BIT. FOR TEMPS GENERALLY STAYED CLOSE TO A BLEND OF MODEL GUIDANCE WHILE MAINTAINING EFFECTS OF RELATIVE ELEVATION AL DIFFERENCES...WHERE APPLICABLE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 120 AM EDT SAT JUN 22 2013 SURFACE HIGH PRESSURE WILL PROVIDE FOR MAINLY VFR CONDITIONS AND LIGHT WINDS ACROSS THE AREA THROUGH THE PERIOD. PATCHY VALLEY FOG WILL CONTINUE TO DEVELOP THROUGH DAWN...WITH SOME VSBY REDUCTIONS EXPECTED AT LOZ AND SME. ISOLATED THUNDERSTORMS WILL THEN REFIRE AFTER ABOUT 17Z TOMORROW...ALTHOUGH THE PROBABILITY THAT ONE WILL IMPACT A TAF SITE IS ONLY AROUND 20 PERCENT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ABE SHORT TERM...JJ LONG TERM...GREIF/RAY AVIATION...ABE
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
710 PM EDT SUN JUN 23 2013 .SYNOPSIS... WARM AND MOIST AIR CONTINUES TO POOL SOUTH OF A STATIONARY FRONT TO OUR NORTH. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH DAY THROUGH THE WEEK AS SEVERAL DISTURBANCES CROSS THE REGION. A LARGE UPPER LEVEL TROUGH WILL APPROACH FROM THE WEST LATE IN THE WEEK. THIS WILL ALLOW FOR COOLER TEMPERATURES...BUT INCREASE THE CHANCE FOR SHOWERS ACROSS THE REGION. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... .UPDATE... HAVE CANCELLED THE SEVERE THUNDERSTORM WATCH FOR COOS...OXFORD... ANDROSCOGGIN...AND GRAFTON COUNTIES. LARGE AREA OF CIN HAS DEVELOPED OVER THESE AREAS IN THE WAKE OF A COLD POOL. ANY THUNDERSTORMS THAT DO DEVELOP OVER THESE AREAS MAY STILL HAVE HEAVY RAIN...SMALL HAIL...AND GUSTY WINDS...BUT SHOULD STAY NON SEVERE. THE WATCH CONTINUES FOR SOUTHERN NH AND SW MAINE AS WELL AS ADJACENT COASTAL AREAS. SO FAR REPORTS OF SEVERE WEATHER HAVE BEEN SPOTTY WITH A FEW REPORTS OF WIND DAMAGE AND LARGE HAIL RECEIVED. TEMPERATURES AND DEW POINTS ARE DROPPING BEHIND THE COLD POOL AND THESE ELEMENTS HAVE BEEN ADJUSTED IN THE LATEST FORECAST UPDATE. && PREVIOUS DISCUSSION... MESOSCALE MODELS LIKE THE HRRR HAVE A GOOD HANDLE ON ONGOING CONVECTION TO OUR WEST. SHOWERS AND THUNDERSTORMS WHICH HAVE FORMED IN THE HIGHER TERRAIN WILL COALESCE AND SPREAD DOWNSTREAM IN THE NEXT FEW HOURS AS A COLD POOL DEVELOPS. SHOWERS AND THUNDERSTORMS SHOULD FORM A LOOSE MULTICELL LINE OVER CENTRAL/SOUTHERN NEW HAMPSHIRE AND INTO SW MAINE...MOVING OFFSHORE THIS EVENING. THE SEVERE WEATHER THREAT LOOKS HIGHEST OVER SOUTHERN AND CENTRAL NEW HAMPSHIRE WHERE MORE INSOLATION HAS OCCURRED AND SURFACE-BASED CAPES OF 1200-1500 J/KG RESIDE. THE BIGGEST SEVERE WEATHER THREAT WILL BE DAMAGING WINDS. TRAINING...AMPLE UNIDIRECTIONAL SHEAR...AND PRECIPITATION LOADING WILL SUPPORT THE THREAT OF WET DOWN BURSTS. FACTORS LIMITING SEVERE WEATHER INCLUDE THE LACK OF ANY REAL FOCUSING MECHANISM OR UPPER LEVEL SUPPORT...AS WELL AS A RELATIVELY HIGH FREEZING LEVEL. NEW STORMS WILL LIKELY DEVELOP ALONG OUTFLOW MERGERS AND IN AREAS OF DIFFERENTIAL HEATING. GYX SOUNDING FROM THIS MORNING HAS 1.72 INCHES OF PRECIPITABLE WATER...WHICH IS CLOSE TO 2 STANDARD DEVIATIONS ABOVE NORMAL FOR THE END OF JUNE. SATURATED AND WARM CLOUDS WILL CONTINUE TO SUPPORT VERY HEAVY RAIN AND WARM RAIN PROCESSES. QPF AMOUNTS FOR THIS EVENING WILL VARY WIDELY DEPENDING ON WHERE CONVECTION DEVELOPS. TRAINING CELLS AND ANY UPSLOPE COMPONENT WILL HELP TO LOCALLY BOOST RAINFALL TOTALS OVER ISOLATED AREAS...PERHAPS 1-2 INCHES. OTHER LOCATIONS MAY SEE LESS THAN A TENTH OF AN INCH. MUCH OF THE ACTIVITY WILL DIMINISH WITH THE LOSS OF DIURNAL HEATING...AND AS A WEAK SURFACE TROUGH SHIFTS OFFSHORE. OVERNIGHT LOWS WILL BE IN THE LOWER TO MID 60S AS THE LOWER LEVELS OF THE ATMOSPHERE REMAIN SATURATED...LEADING TO PATCHY DENSE FOG DEVELOPMENT. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... ANOTHER WEAK TROUGH CROSSES THE AREA TOMORROW WITH NEARLY ZONAL FLOW ALOFT. SKIES WILL BE PARTLY CLOUDY ACROSS THE SOUTH INITIALLY...AND THIS ALONG WITH WESTERLY WINDS WILL HELP BOOST TEMPERATURES INTO THE 80S AND 90S. DEW POINTS REMAIN IN THE UPPER 60S MAKING FOR AN UNPLEASANTLY MUGGY DAY. HEAT INDEX VALUES REACH THE LOWER 90S...STAYING SHORT OF ADVISORY CRITERIA. MOISTURE WILL BE WRUNG OUT ONCE AGAIN IN THE FORM OF AFTERNOON AND EVENING THUNDERSTORMS. HIGHER INSTABILITY WILL BE LOCATED OVER NORTHERN AREAS...BUT A THUNDERSTORM COULD POP UP ANYWHERE WITH BROAD WEAK FORCING. && .LONG TERM /TUESDAY THROUGH SUNDAY/... WARM AND HUMID WEATHER WILL CONTINUE THROUGH TUESDAY AND INTO WEDNESDAY. WARM 850 MB TEMPERATURES OF +18C COULD LEAD TO HIGHS REACHING THE 90 DEGREE MARK ACROSS SOUTHERN AND EASTERN NEW HAMPSHIRE AND SOUTHWEST MAINE. WITH DEW POINTS IN THE UPPER 60S TO LOW 70S... IT WILL BE HUMID. HEAT INDEX READINGS WILL TOP 90 DEGREES ACROSS THE COASTAL PLAIN OF MAINE AND NEW HAMPSHIRE... WITH SOME READINGS APPROACHING 95. ALTHOUGH THIS IS SHORT OF ADVISORY LEVELS... IT WILL STILL BE NOTICEABLY HOT AND HUMID. WITH HOT AND HUMID WEATHER COMES THE THREAT OF THUNDERSTORMS. A SHORTWAVE TROUGH WILL BE CROSSING SOUTHERN CANADA AND INTO NORTHERN NEW ENGLAND ON TUESDAY... ADDING UPPER LEVEL SUPPORT TO AN UNSTABLE AIR MASS TO PRODUCE THUNDERSTORMS ACROSS THE REGION. NAM IS SHOWING STRONGER MID AND UPPER LEVEL FLOW THAN THE GFS... AND IF THIS IS THE CASE THEN THERE WILL BE AMPLE DEEP LAYER SHEAR TO SUPPORT SUPERCELLS AND MULTICELL CLUSTERS AS DESCRIBED BY THE STORM PREDICTION CENTER IN THEIR MORNING OUTLOOK INDICATING A SLIGHT RISK ACROSS NORTHERN NEW ENGLAND. THE UNIDIRECTIONAL SHEAR INDICATES THAT THERE WILL BE PRIMARILY A DAMAGING WINDS AND HAIL THREAT RATHER THAN A TORNADO THREAT. IN ADDITION... THE HUMID AIR WILL ALLOW THUNDERSTORMS TO DROP VERY HEAVY RAINFALL. ANY TRAINING THUNDERSTORMS COULD LEAD TO FLASH FLOODING. WITH HIGH DEW POINTS EXPECTED... DO NOT EXPECT TEMPERATURES TO COOL OFF MUCH TUESDAY NIGHT. AFTER HIGHS IN THE 90S AND DEW POINTS IN THE UPPER 60S TO LOW 70S... IT WILL BE DIFFICULT FOR TEMPERATURES TO FALL MUCH BELOW 70 FOR MOST AREAS IN THE FEW HOURS OF NIGHT THAT EXIST THIS TIME OF YEAR. AS A RESULT... RAISED LOW TEMPERATURES FROM GUIDANCE VALUES AS MAV/MET TEND TO BE TOO COLD ON HUMID NIGHTS SUCH AS THIS. ANOTHER SHORTWAVE TROUGH CROSSES THE AREA TUESDAY NIGHT OR WEDNESDAY AND WILL PROVIDE ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS. TIMING DIFFERENCES IN THE MODELS MAKES IT DIFFICULT TO PROVIDE MORE CONFIDENCE VIA HIGHER POP VALUES. GFS AND CMC BOTH SEEM TO BE SUFFERING FROM FEEDBACK RESULTING FROM CONVECTION. GFS DEVELOPS A CLOSED 999 MB SURFACE LOW CROSSING THE AREA TUESDAY NIGHT WHILE THE CMC IS SIMILAR BUT NOT AS STRONG. THIS SOLUTION SEEMS UNLIKELY AND WAS DISCOUNTED IN FAVOR OF THE ECMWF WHICH SHOWS A MORE PROGRESSIVE SHORTWAVE CROSSING THE REGION. A COLD FRONT DROPS SOUTH ACROSS THE AREA ON WEDNESDAY... BRINGING COOLER AIR DOWN FROM THE GULF OF SAINT LAWRENCE AND EASTERN CANADA. 850 TEMPERATURES DROP ABOUT 4C WEDNESDAY AS COMPARED TO TUESDAY AND MAX TEMPERATURES SHOULD REFLECT THIS. HOWEVER... DOWNSLOPING NORTHWEST WINDS WILL PROVIDE FOR DEEP MIXING ALONG THE COASTAL PLAIN OF NEW HAMPSHIRE AND SOUTHWEST MAINE... ALLOWING TEMPERATURES TO CLIMB INTO THE MID TO UPPER 80S FOR ONE MORE DAY. HIGH PRESSURE BUILDING SOUTH OUT OF EASTERN CANADA WILL BRING AN EASTERLY TO SOUTHEASTERLY FLOW ON THURSDAY. ECMWF SHOWS A PRONOUNCED EASTERLY FLOW ACROSS THE AREA WHICH WOULD KEEP A COOL MARINE AIR MASS IN PLACE. WATER TEMPERATURES OFF THE NEW HAMPSHIRE COAST AREA IN THE LOW 60S... WHILE WATER TEMPERATURES OFF THE MIDCOAST OF MAINE ARE IN THE LOW 50S. EVEN THE GFS SHOWS A SOUTH TO SOUTHEAST FLOW ON THURSDAY WHICH WOULD KEEP MUCH OF MAINE COOL. AS A RESULT... HAVE GONE WITH COLDER TEMPERATURES FOR WEDNESDAY WITH HIGHS IN THE LOW 70S ACROSS MAINE TO THE UPPER 70S FOR NEW HAMPSHIRE. THIS WAS MORE IN LINE WITH THE ECMWF MOS AND HPC. ALL MODELS NOW IN GOOD AGREEMENT THAT A LARGE SCALE TROUGH WILL BE APPROACHING THE AREA BY THURSDAY NIGHT... SPREADING BROAD SCALE LIFT OVER NEW ENGLAND IN COMBINATION WITH AN ONSHORE SOUTHEAST FLOW. AS A RESULT... INCREASED POPS INTO THE 60 TO 70 PERCENT RANGE TO REFLECT THE INCREASED CONFIDENCE IN TIMING. UNFORTUNATELY... THIS BROAD SCALE TROUGH LINGERS TO THE WEST OF NEW ENGLAND THROUGH THE WEEKEND... LEAVING THE FORECAST AREA WITHIN THE FAVORABLE AREA FOR RISING MOTION AND PRECIPITATION. TIMING OF SUBTLE SHORTWAVE TROUGHS WITHIN THE FLOW AND ASSOCIATED SURFACE FEATURES VARIES AMONG THE MODELS AND IS DIFFICULT TO FORECAST THIS FAR OUT. AS A RESULT... HAVE INDICATED A CHANCE OF SHOWERS OR THUNDERSTORMS FROM FRIDAY THROUGH THE WEEKEND. && .AVIATION /23Z SUNDAY THROUGH FRIDAY/... SHORT TERM...VFR SKIES IN VCTS THIS EVENING. SHOWERS AND THUNDERSTORMS DIMINISH OVERNIGHT WITH PATCHY DENSE FOG AND STRATUS DEVELOPING. MOISTURE TRAPPED UNDER AN INVERSION WILL KEEP PERIODS OF LIFR AND VLIFR CEILINGS IN THE TERMINAL FORECASTS. WEST WINDS ON MONDAY MAY GUST INTO THE LOWER 20S. LONG TERM...OVERNIGHT FOG IS POSSIBLE EACH NIGHT IN THE VALLEY LOCATIONS... AS WELL AS AFTERNOON HAZE AND THUNDERSTORMS THROUGH TUESDAY. A COLD FRONT BRINGS COOLER AIR IN FOR WEDNESDAY. AN ONSHORE FLOW ON THURSDAY COULD BRING IFR CONDITIONS PERHAPS WORSENING TO LIFR BY THURSDAY NIGHT AND FRIDAY IN SHOWERS. && .MARINE... SHORT TERM...HELD OFF ON A SMALL CRAFT ADVISORY AS GUIDANCE HAS BEEN OVERDOING WAVE HEIGHTS. THAT SAID A FEW 5-6 FOOTERS MAY DEVELOP ON THE FAR OUTER WATERS. WINDS WILL STAY BELOW 25 KTS WITH A FEW GUSTS INTO THE LOWER 20S. LONG TERM...EXPECT A GENERAL SOUTHWEST FLOW OVER THE WATERS THROUGH WEDNESDAY THOUGH IT SHOULD REMAIN BELOW 25 KT. GFS MODEL IS FORECASTING A STRONGER SURFACE LOW TO CROSS INTO THE GULF OF MAINE FROM THE WEST ON WEDNESDAY BUT THIS IS LIKELY OVERDONE DUE TO CONVECTION WITHIN THE MODEL. AS A RESULT... WAVE HEIGHTS GENERATED BY THE WNA WAVE MODEL WERE TOO HIGH ON THE SOUTHWEST FLOW AHEAD OF THE FRONT. EXPECT WINDS AND WAVES TO STAY BELOW SMALL CRAFT ADVISORY CONDITIONS AHEAD OF AND BEHIND THE FRONT ON WEDNESDAY. HIGH PRESSURE DROPS SOUTH OUT OF CANADA AND INTO THE WESTERN ATLANTIC AND GULF OF MAINE FOR THURSDAY WITH A SOUTHERLY FLOW RETURNING BY FRIDAY. && .TIDES/COASTAL FLOODING... A PORTLAND HIGH TIDE OF 11.8 FT IS EXPECTED TONIGHT AT 11:41 PM. FLOOD STAGE AT PORTLAND IS 12.0 FT. WINDS WILL BECOME WSW TONIGHT AND NEARLY PARALLEL TO THE COAST. THIS IS NOT A FAVORED DIRECTION FOR COASTAL EROSION OR SPLASH OVER. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ UPDATE...HANES
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1008 PM EDT SUN JUN 23 2013 .SYNOPSIS... HIGH PRESSURE BECOMES ANCHORED OFF THE MID ATLANTIC COAST THROUGH FRIDAY...RESULTING IN A CONTINUED PERIOD OF VERY WARM AND HUMID CONDITIONS. THERE WILL BE A CHANCE FOR AFTERNOON AND EVENING THUNDERSTORMS EACH DAY. A COLD FRONT APPROACHES FROM THE WEST SATURDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... WK TROUGH ALOFT LINGERS INVOF FA THIS EVE. MUCH LESS CNVTN THAN SAT EVE...AND WHAT THERE HAS BEEN GENLY DISSIPATED IN THE LAST HR OR TWO. 01Z/24 RUC13 SUGGESTS CONTD (MNLY) SLGT CHC POPS FOR EXTREME SE PORTION OF FA...AND CNVTN NOW NW OF THE FA TO RMN AWAY FM THE RGN. OTRW...VRB CLDS TO PCLDY CONDS...WARM AND HUMID OVRNGT. FG PTNTL IS LO. LO TEMPS FM THE U60S TO L70S. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... BERMUDA HIGH PRS BECOMES THE DOMINATE WX FEATURE ACROSS THE SERN CONUS FOR THE WORKWEEK. ENUF LINGERING MSTR COMBINED WITH DYTME HTNG RESULTS IN SCT DIURNAL CONVECTION BOTH MON AND TUE WITH THE HIGHEST CHCS WEST OF CHES BAY. HIGHS MON 85-90...A BIT COOLER ON THE BEACHS. LOWS MON/TUE NITES U60S-L70S. HIGHS TUE ARND 90...REMAINING IN THE 80S AT THE BEACHES. NOT MUCH OF A TRIGGER SEEN FOR WED AS H5 HGHTS MAX OUT. WILL KEEP ISLTD POPS FOR NOW. HIGHS WED L90S W OF BAY...U80S ALONG THE COAST. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A MORE AMPLIFIED PATTERN IS EXPECTED TO DEVELOP OVER NORTH AMERICA AS WE HEAD INTO LATE IN THE COMING WEEK. A STRONG UPPER RIDGE OF HIGH PRESSURE WILL DEVELOP OVER THE FOUR CORNERS REGION BY THURSDAY...THEN REMAINS IN PLACE THROUGH NEXT WEEKEND. MEANWHILE... A POTENT UPPER LOW DIGGING INTO ONTARIO CANADA ON THURSDAY WILL CONTINUE TO TRACK SE INTO THE EASTERN GREAT LAKES BY SATURDAY/SUNDAY AND WILL CARVE OUT A BROAD TROUGH ACROSS THE EASTERN CONUS. AS FAR AS THE SENSIBLE WX...WARM AND HUMID CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE PERIOD. THURSDAY LOOKS TO BE THE LEAST ACTIVE DAY AS FAR AS CONVECTION (MAINLY SLIGHT CHC POPS)...BEFORE BETTER ORGANIZATION OF SHOWERS AND TSTMS LOOKS PROBABLE FRI/SAT (40-50% POPS) AS THE TROUGH SHARPENS OVER THE MID-ATLANTIC. BY SAT NIGHT/SUNDAY...SFC FRONTAL BOUNDARY LOOKS LIKE IT PUSHES SOUTH OF THE LOCAL AREA AND STALLS ALONG THE CAROLINA COAST. THIS WOULD FOCUS CONVECTION MORE ACROSS OUR SOUTHERN AREAS...AND HAVE TRENDED THE FORECAST IN THAT DIRECTION. HIGHS THROUGH THE PERIOD IN THE UPPER 80S TO LOW 90S AND LOWS MAINLY 70-75. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... A WEAK UPPER LOW PRES SYS OVER WV WILL MOVE NE THRU THE NIGHT AND SLOWLY WEAKEN. WITH HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL KEEP PLENTY OF LOW LEVEL MOISTURE OVER THE AREA AS WINDS CONTINUE FROM THE SOUTH. MOST OF THE SHOWERS HAVE DISSIPATED THIS EVENING BUT AN ISOLATED SHOWER WILL BE POSSIBLE UNTIL MIDNIGHT. THEN SKIES WILL BE PARTLY CLOUDY WITH A MIX OF MID AND HIGH LEVEL CLOUDS LEFT FROM THE EARLIER CONVECTION. IT IS POSSIBLE SOME PATCHY FOG COULD FORM TOWARD MORNING. BEST CHANCES WILL BE AT RIC PHF AND SBY. WITH STRONGER SURFACE WINDS PERSISTING THROUGH THE NIGHT ECG AND ORF SHOULD NOT HAVE ANY FOG TONIGHT. IF THE WIND DOES DIMINISH ECG COULD HAVE SOME PATCHES EARLY IN THE MORNING. ON MONDAY SCATTERED CU WILL DEVELOP ACROSS THE AREA DURING THE DAY. ISOLATED CONVECTION WILL AGAIN DEVELOP DURING THE AFTERNOON. WITH NO STRONG FOCUS FOR THE CONVECTION THESE STORMS WILL BE ISOLATED AND HARD TO PINPOINT WHERE THEY WILL OCCUR. HIGH PRESSURE WILL REMAIN ANCHORED OFF THE MID ATLANTIC AND SE COASTS INTO THE MIDDLE OF NEXT WEEK AND WILL CONTINUE TO STREAM A MOIST SUBTROPICAL AIRMASS INTO THE REGION. THIS WILL KEEP UNSETTLED CONDITIONS ACROSS THE AREA WITH RAIN SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY. && .MARINE... MODELS REMAIN IN GOOD AGREEMENT WITH KEEPING BERMUDA HIGH PRESSURE ANCHORED OFF THE SE COAST THROUGH THE MIDDLE OF THE COMING WEEK. THIS WEATHER PATTERN WILL KEEP SHWR/TSTM CHANCES IN THE FORECAST EACH DAY...BUT WILL ALSO BE RATHER BENIGN IN REGARDS TO WIND SPEEDS. SSW WINDS WILL AVERAGE AOB 15 KT OUTSIDE OF ANY AFTN/EVENING CONVECTIVE ACTIVITY. EXPECT WAVES OF 1-2 FT ON THE BAY/SOUND/RIVERS AND SEAS OF GENERALLY 2-4 FT (HIGHEST IN NRN COASTAL WATERS). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...ALB/MPR NEAR TERM...ALB/MPR SHORT TERM...MPR LONG TERM...JDM AVIATION...JEF/JAB MARINE...JDM
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1002 PM EDT SUN JUN 23 2013 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION MONDAY. THE HEAT AND HUMIDITY WILL BUILD THROUGH MIDWEEK UNDER THE INFLUENCE OF BERMUDA HIGH PRESSURE. AN UPPER TROUGH WILL AMPLIFY OVER THE GREAT LAKES REGION LATE THIS WEEK AND INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... DIURNAL SHRA/TSRA WERE FEW AND FAR BTWN TAFTN...LKLY DUE TO AN ABSENCE OF SYNOPTIC SCALE FORCING AND A LT START TO AMS DSTBLZTN. BUT...AMS DID BECOME UNSTBL BY 21-22Z...AND A FEW TSRA DVLPD ALNG THE APLCHNS. THESE MULTIPLIED AT THE CONFLUENCE OF 1000-2000 J/KG SBCAPE AND 20 KT BULK SHEAR...AIDED BY WK LLVL CNVGNC AND OROGRAPHIC LIFT. BOTH RNK/IAD RAOBS DEPICT HOW THE MTNTOPS WUD BE UNSTBL...AND AREA E OF THE BLURDG CAPPED. HV MADE UPWD TICK IN POPS/WX IN THE W BASED ON RDR TRENDS. WL CONT W/ DRY FCST IN THE E. ONLY QUESTION THAT REMAINS WL BE HOW TO ADDRESS TSRA/SHRA DECAY. HRRR SUGGESTS IT WONT /ALL NGT/... BUT ITS BEEN IN CATCH-UP MODE MUCH OF THE NGT. OTHER MESO GDNC /WRF- ARW4 AND RUC13 IN PARTICULAR/ SUGGESTS A QUICK DEMISE. NEW 00Z NAM KEEPS A SOLN SOMEWHERE IN BTWN. ECHOES HEALTHY ENUF THAT BELIEVE THEY/LL HANG ON FOR AT LEAST A CPL MORE HRS...BUT HV LOW CONFIDENCE BYD THAT. WL HV A MOIST AMS OVNGT /DEWPTS UPR 60S-LWR 70S/ W/ A MOCLR SKY. THAT SUGGESTS THAT OVNGT FOG DVLPMNT STANDS A BETTER CHC THAN PAST CPL NGTS. MOST ZONES WL HV PATCHY WORDING. HV BEEFED UP FOG TO AREAS FOR THOSE LOCATIONS THAT RECEIVED EVNG HRA/TSRA. LAMP APPEARS TO HV A GOOD FEEL FOR TEMPS...AND HV INCRSD MIN-T BASED ON LTST RUN. IN PARTICULAR...DOWNTOWNS WONT RADIATE THAT WELL W/ L70 DEWPTS...WHICH REQD AN INCR OF MIN-T INTO THE 70S. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... 500MB TROUGH WILL MOVE EWD THROUGH THE MID-ATLANTIC REGION MONDAY...AND MODELS INDICATE A POTENTIAL LEE TROUGH DEVELOPING E OF THE BLUE RIDGE. WARM MOIST AIR CONTINUES TO BE ADVECTED INTO THE REGION DUE TO AN OFFSHORE BERMUDA HIGH. HIGH TEMPS WARM INTO THE UPPER 80S/LOW 90S ACROSS THE REGION...WITH MAX HEAT INDICES IN THE LOW TO MID 90S. DAYTIME SHOWER/TSTM POTENTIAL ONCE AGAIN THROUGH COMBINATION OF MOIST/UNSTABLE AIRMASS AND THE PASSAGE OF THE UPPER AND SURFACE TROUGHS. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... HIPRES THAT HAS REMAINED PARKED OFFSHORE WILL SHIFT SOUTHWARD TOWARD BERMUDA ERY IN THE WEEK. THE NORTHWESTERN PERIPHERY OF THE RIDGE WILL BREAK DOWN AS A SERIES OF SHORTWAVE TROUGHS CROSS THE NRN MID-ATLANTIC REGION/NORTHEAST STATES. WAA PATTERN WILL DEVELOP OVER THE REGION DURING THIS TIME AS WINDS VEER IN RESPONSE TO THE RIDGE BREAKING DOWN. ABOVE NORMAL TEMPS ARE IN STORE DURING THE SHORT TERM. FAVORED SLIGHTLY LOWER DEWPOINTS AS DOWNSLOPING W-SWLY FLOW WILL HELP MIX DOWN DRIER AIR EACH AFTN. NONETHELESS... THE COMBINED EXPECTED HEAT AND HUMIDITY YIELDS HEAT INDICES IN THE LOWER TO MID 90S ALONG AND EAST OF I-95 TUE. GUIDANCE INDICATING THE NEXT MID-LVL SHORTWAVE TROUGH APPROACHING FROM THE MIDWEST TUE-TUE NGT ALTHOUGH THERE IS UNCERTAINTY IN TIMING WITH THIS SYSTEM. SHOWERS AND STORMS MAY DEVELOP AGAIN DURING THE PEAK HEATING HRS. RETURN FLOW AROUND THE BERMUDA HIGH WILL CONTINUE TO TURN UP THE HEAT AND HUMIDITY DURING THE MIDDLE OF THE WEEK. THE 00Z GFS PROG H8 TEMPS OF 20-21C WED AND THU WHILE THE 00Z ECMWF FCST IS A DEGREE OR TWO LOWER. A COMPROMISE BETWEEN THE TWO MODELS WOULD YIELD MAX TEMPS IN THE LOW TO MID 90S BOTH DAYS...WHICH WOULD BE THE WARMEST OF THE YEAR THUS FAR. COMBINED WITH THE HUMIDITY...HEAT INDICES ARE FCST TO PEAK IN THE MID TO UPPER 90S ALONG AND EAST OF I-95. CAPPING INVERSION LOOKS STRONGEST ON WED WHILE SYNOPTIC LIFT APPEARS ABSENT. KEPT WED FCST DRY EAST OF THE BLUE RIDGE ACCORDINGLY WHILE MTN SHOWERS AND STORMS MAY DEVELOP DURING THE AFTN. UPPER RIDGE IS FCST TO AMPLIFY OVER THE FOUR CORNERS REGION LATE IN THE WEEK WHILE DOWNSTREAM TROUGHING DEVELOPS OVER THE GREAT LAKES. CHANCES FOR SHOWERS AND STORMS WILL INCREASE DURING THIS TIME AS LIFT AHEAD OF THE TROUGH SPREADS INTO THE MID-ATLANTIC STATES. UNSETTLED CONDITIONS LOOK TO CONTINUE INTO THE WEEKEND WITH THE UPPER TROUGH AMPLIFYING OVER THE ERN CONUS. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... VFR FLGT CONDS AT THE AIRPORTS ATTM...AND SHUD REMAIN SO THRU THE EVNG. DO XPCT MVFR-IFR FOG TO DVLP OVNGT...IMPACTING THE BGNG OF MRNG PUSHES. FOG SHUD ERODE BY MID-MRNG...SETTING UP A FAIRLY TYPICAL SUMMER DAY. XPCT CU DVLPMNT BY ELY AFTN INVOF TROF AXIS...WHICH IN TURN WUD SUPPORT SCT TSRA. HV 040-050 CLD BASES IN GRIDS...BUT THESE DONT TRIGGER A CHG GRP IN TAFS. SIMILARLY...THE CONFIDENCE IN AREAL CVRG AT THIS POINT PRECLUDE A TAF MENTION. PSBL RADIATIONAL FOG DURING THE ELY MRNG HRS...AND SCT AFTN-EVNG SHOWERS AND STORMS WL REMAIN THE CALLING CARD INTO MIDWEEK. CHANCES FOR SHOWER AND STORMS INCREASE LATE IN THE WEEK AS AN UPPER TROUGH AMPLIFIES OVER THE GREAT LAKES. && .MARINE... WNDS DECREASED BLO SCA LVLS TAFTN...AND THAT SCA WAS CANX. HWVR... GDNC SUGGESTING THAT A LLJ WL INDUCE SLY CHANNELING UP THE BAY THIS EVNG. WL BE SETTING LOOSE A NEW SCA FOR THE BAY UP TO POOLES ISLAND INCL ERN INLETS FOR THE EVNG HRS-- 8PM-2AM. WNDS SHUD DECREASE OVNGT-ELY MRNG. SLY RETURN FLOW AROUND HIPRES WILL CONTINUE THRU MUCH OF WORK WEEK. WINDS SHOULD BE LGT THRU MIDWEEK BEFORE INCREASING LATE IN THE WEEK AS A TROUGH APPROACHES FROM THE WEST. WINDS MAY INCREASE TO SCA LVLS BY THU. AN ADDTL CONCERN WL BE ALMOST DAILY TSRA CHCS...SPCLY FOR THE AFTN-EVNG HRS. ALL OF THESE WL POSE LIGHTNING RISKS ALONG W/ LCLY HIER WNDS/WVS. A FEW OF THESE MAY BE STRONG ENUF TO PROMPT ISSUANCE OF SPECIAL MARINE WRNGS. && .TIDES/COASTAL FLOODING... WATER LEVELS HAVE BEEN RUNNING BETWEEN A QUARTER AND A HALF FOOT ABOVE ASTRONOMICAL TIDE TODAY. THE AFTERNOON HIGH TIDE CYCLE IS THE LOWER OF THE TWO DIURNAL CYCLES...AND THE TIDE HAS REACHED THE NORTHER REACHES WITHOUT ANY COASTAL FLOODING CONCERNS. THE MONDAY MORNING HIDE TIDE WILL BE ASTRONOMICALLY SIMILAR TO SUNDAYS. SINCE NO TIDAL FLOODING OCCURRED SUNDAY MORNING...ANOMALIES WILL NEED TO INCREASE IN ORDER TO FLOODING TO OCCUR. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT MONDAY FOR ANZ531>534- 539>541-543. && $$ SYNOPSIS...KCS NEAR TERM...HTS SHORT TERM...KCS LONG TERM...JRK AVIATION...HTS MARINE...HTS TIDES/COASTAL FLOODING...KCS/HTS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
724 AM EDT SAT JUN 22 2013 .SYNOPSIS... A WEAK AREA OF LOW PRESSURE WILL LINGER ALONG THE NORTH CAROLINA COAST THROUGH TODAY. HIGH PRESSURE WILL BE ANCHORED OFF THE MID ATLANTIC COAST SUNDAY THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... INTERESTING FORECAST CHALLENGES TODAY. HAVE CONVECTION DEVELOPING ALONG A COASTAL FRONT OVER NORTH CAROLINA AND SLOWLY MOVING NORTH. THIS IS ASSOCIATED WITH A WEAK PV MAX ALOFT AND CAN BE SEEN ON WATER VAPOR. MEANWHILE HAVE A WEAK RIDGE OF HIGH PRESSURE ALOFT JUST TO THE NORTH OF THIS FEATURE. THIS HIGH IS SLOWLY WEAKENING AND MOVING TO THE EAST. THIS WILL ALLOW THE WEAK TROF TO LIFT NORTH TODAY. CAN SEE WINDS BECOMING MORE SOUTHEAST ALOFT ON VWP OBSERVATIONS AROUND THE AREA. THIS WILL ADVECT PLENTY OF MOISTURE INTO THE SOUTHERN PART OF THE CWA TODAY. WILL FOLLOW THE HRRR IDEA OF MOVING THE PRECIPITATION FROM NORTH CAROLINA INTO SOUTHEAST VIRGINIA DURING THE MORNING. COULD SEE SOME BRIEF HEAVY RAIN WITH SOME OF THE SHOWERS. BY THIS AFTERNOON THE MOISTURE WILL BE PULLED NORTH OVER MOST OF THE CWA. HOWEVER THE UPPER TROF WILL BE WEAKENING AND THIS WILL CAUSE THE PRECIPITATION TO MORE SCATTERED. THIS FOLLOWS THE NAM AND GFS. ALSO THE SREF SHOWS THE BEST CHANCES FOR PRECIP MOVING TO THE WESTERN SECTIONS OF THE CWA DURING THE AFTERNOON AND EVENING. SINCE WESTERN AREAS WILL BE SLOWER TO CLOUD UP WILL HAVE SOME MORE CAPE TO AIDE IN THUNDERSTORM DEVELOPMENT. AGAIN WITH PLENTY OF MOISTURE AROUND COULD SEE SOME BRIEF HEAVY DOWNPOURS. TEMPERATURES WILL BE DEPENDENT ON THE AMOUNT OF CLOUD COVER TODAY. EXPECT TO KEEP MAXES AROUND 80 SOUTHEAST BUT REACH THE MID 80S ACROSS WESTERN SECTIONS. AGAIN THIS IS CLOSE TO MOS GUIDE. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... A SECOND UPPER LOW OVER GEORGIA TODAY WILL SLOWLY LIFT NORTH LATE TONIGHT AND MOVE ACROSS TO THE WEST OF THE AREA ON SUNDAY. THE UPPER LOW AGAIN WILL BE WEAKENING AS IT MERGES WITH THE WESTERLY TO THE NORTH. THIS THIS WILL HELP TO KEEP BEST CHANCES OF SHOWERS AND THUNDERSTORMS IN THE WESTERN AREAS TONIGHT AND SATURDAY. WITH THE HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL HAVE MOISTURE FEED OFF THE WATER COMING INTO THE AREA WITH SOME RISE TO THE EAST WINDS AS THEY APPROACH THE RIDGES TO THE WEST. BY MONDAY THIS FEATURE IS WEAKENING AND MORE NORTHEAST AWAY FROM THE AREA. HOWEVER WILL STILL HAVE PLENTY OF MOISTURE ACROSS THE AREA SO WILL CONTINUE CHANCE TO SLIGHT CHANCE POPS ESPECIALLY ON MONDAY AFTERNOON WITH THE BEST CHANCES IN THE WEST WHERE THE LOW LEVEL EAST WINDS WILL BEGIN TO RISE AS THEY APPROACH THE MOUNTAINS TO THE WEST. WILL GO FAIRLY CLOSE TO MOS GUIDANCE FOR TEMPERATURES WITH THE WARMEST DAY ON MONDAY AS LESS CLOUD COVER THEN. LOWS AT NIGHT WILL MAINLY BE IN THE MID TO UPPER 60S. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... PERIOD BEGINS WITH A BROAD MID/UPPER LEVEL RIDGE CENTERED OVER MUCH THE SOUTHERN TIER OF THE CONUS...GRADUALLY EVOLVING INTO A STRONG RIDGE OVER THE SW STATES WITH A FAIRLY DEEP TROUGH CENTERED JUST NORTH OF THE GREAT LAKES ACRS ONTARIO CANADA. THIS WILL TRANSLATE INTO A W/NW UPPER FLOW PATTERN INTO THE MID ATLC STATES. WHILE A SERIES OF WEAK SHORTWAVES BEGIN TO SHUNT THE RIDGE OFF TO THE S/SW OF THE CWA TUE/WED...TIMING THESE FEATURES IN THE MEDIUM RANGE IS QUITE DIFFICULT SO WILL GENLY HAVE ONLY A 20% CHANCE FOR MAINLY DIURNAL/AFTN/EVENING TSTMS TUE/WED. TEMPERATURES WILL WARM TO A LITTLE ABOVE AVG FOR LATE JUNE...MAINLY IN THE UPPER 80S TO LOWER 90S FOR HIGHS WITH LOWS IN THE UPPER 60S TO LOWER 70S. BY THU/FRI...A MORE DEFINED SFC BOUNDARY SETS UP NOT TOO FAR TO THE NORTH OF THE CWA...AND 500 MB HEIGHTS SLOWLY FALL...SO HAVE POPS HIGHER THAN CLIMO BOTH DAYS (ESPECIALLY FRI). HIGHS IN THE UPPER 80S TO LOWER 90S AND LOWS MAINLY FROM 70-75. && .AVIATION /11Z SATURDAY THROUGH WEDNESDAY/... APART FROM LINGERING IFR/LIFR IVOF KSBY, GENERALLY VFR/MVFR AT AREA TERMINALS THIS MORNING. STILL EXPECTING SCT SHRAS TO PUSH NW FROM COASTAL CAROLINAS TOWARDS COASTAL TERMINALS LATER THIS MORNING, AND HV LEANED ON HRRR IN TAKING THE PARENT LOW AND THE ASSOCIATED PCPN SHIELD N-NW INTO NE NC. GIVEN UNCERTAINTY WITH TIMING OF SHRAS, HV GONE WITH VCSH NOW IN THE TAF AT PHF/ECG/ORF. DO EXPECT TO SEE SOME BREAKS IN STRATUS AT RIC/SBY AFTER 13-15Z, BUT HV GONE WITH VICINITY SHRA WORDING AT RIC AFTER 16Z. LOW PRESSURE WL SLOWLY WEAKEN TO OUR SOUTH,W/ CIGS WL GENERALLY TO RANGE FROM MVFR TO VFR THROUGH THE AFTN. OUTLOOK: MORE LATE NIGHT STRATUS IS EXPECTED LATE TONIGHT/SUN MORNING. OTHERWISE, EXPECT PREDOMINATE VFR CONDITIONS ASIDE FROM SCATTERED MAINLY DIURNALLY DRIVEN SHRAS SUN AND THROUGH MIDWEEK AS BREEZY S-SW FLOW REDEVELOPS MON-TUE. && .MARINE... LATEST OBS CONTINUE TO INDICATE ONSHORE (EAST) FLOW ACRS THE ENTIRE REGION. WINDS ARE GENLY 15 KT OR LESS (LIGHTEST OVER NORTHERN AREAS). SEAS CONTINUE TO SLOWLY SUBSIDE THIS MORNING, NOW AOB 4FT ACROSS THE MID-ATLANTIC WATERS. NO MAJOR CHANGES TO THE GOING FORECAST WITH THIS PACKAGE. MSAS 3-HR PRESSURE FALLS CONTINUES TO SHOW SLOW WEAKENING/SLACKENING OF THE PRESSURE GRADIENT BETWEEN THE INVERTED SFC TROUGH/LOW NEAR KILM AT 08Z AND HIGH PRESSURE OFF NORTHERN MID-ATLANTIC COAST. ACCORDINGLY, CONTINUE TO EXPECT CONDITIONS TO REMAIN SUB-SCA TODAY. STILL RATHER UNFAVORABLE BOATING CONDITIONS TODAY, WITH PREDOMINATE LLVL FLOW OUT OF THE E/NE FLOW AGAIN TODAY WITH SEAS 4 FT AND WAVES 2-3 FT AT THE MOUTH OF THE BAY. AS COASTAL FRONT PUSHES BACK WEST THIS AFTN/EVENING, EXPECT WINDS TO GRADUALLY VEER AROUND TO THE ESE, THEN THE SSE BY 06Z/2A SAT NIGHT/SUN MORNING WITH SPEEDS AOB 10 KT. THEREAFTER, GOOD MODEL AGREEMENT IN SETTING UP A RATHER STAGNANT, BUT FAIRLY BENIGN PATTERN FROM LATE SUN THROUGH THE MIDDLE OF NEXT WEEK. SSW WINDS WL AVERAGE AOB 15KT OUTSIDE OF ANY DEVELOPING AFTN/EVENING CONVECTION. WAVES 1-2 FT ON THE BAY/SND/RVRS...SEAS GENERALLY 2-4 FT (HIGHEST NORTHERN COASTAL WATERS). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR VAZ098>100. MARINE...NONE. && $$ SYNOPSIS...JAB NEAR TERM...JAB SHORT TERM...JAB LONG TERM...LKB AVIATION...MAM MARINE...MAM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
402 AM EDT SAT JUN 22 2013 .SYNOPSIS... A WEAK AREA OF LOW PRESSURE WILL LINGER ALONG THE NORTH CAROLINA COAST THROUGH TODAY. HIGH PRESSURE WILL BE ANCHORED OFF THE MID ATLANTIC COAST SUNDAY THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... INTERESTING FORECAST CHALLENGES TODAY. HAVE CONVECTION DEVELOPING ALONG A COASTAL FRONT OVER NORTH CAROLINA AND SLOWLY MOVING NORTH. THIS IS ASSOCIATED WITH A WEAK PV MAX ALOFT AND CAN BE SEEN ON WATER VAPOR. MEANWHILE HAVE A WEAK RIDGE OF HIGH PRESSURE ALOFT JUST TO THE NORTH OF THIS FEATURE. THIS HIGH IS SLOWLY WEAKENING AND MOVING TO THE EAST. THIS WILL ALLOW THE WEAK TROF TO LIFT NORTH TODAY. CAN SEE WINDS BECOMING MORE SOUTHEAST ALOFT ON VWP OBSERVATIONS AROUND THE AREA. THIS WILL ADVECT PLENTY OF MOISTURE INTO THE SOUTHERN PART OF THE CWA TODAY. WILL FOLLOW THE HRRR IDEA OF MOVING THE PRECIPITATION FROM NORTH CAROLINA INTO SOUTHEAST VIRGINIA DURING THE MORNING. COULD SEE SOME BRIEF HEAVY RAIN WITH SOME OF THE SHOWERS. BY THIS AFTERNOON THE MOISTURE WILL BE PULLED NORTH OVER MOST OF THE CWA. HOWEVER THE UPPER TROF WILL BE WEAKENING AND THIS WILL CAUSE THE PRECIPITATION TO MORE SCATTERED. THIS FOLLOWS THE NAM AND GFS. ALSO THE SREF SHOWS THE BEST CHANCES FOR PRECIP MOVING TO THE WESTERN SECTIONS OF THE CWA DURING THE AFTERNOON AND EVENING. SINCE WESTERN AREAS WILL BE SLOWER TO CLOUD UP WILL HAVE SOME MORE CAPE TO AIDE IN THUNDERSTORM DEVELOPMENT. AGAIN WITH PLENTY OF MOISTURE AROUND COULD SEE SOME BRIEF HEAVY DOWNPOURS. TEMPERATURES WILL BE DEPENDENT ON THE AMOUNT OF CLOUD COVER TODAY. EXPECT TO KEEP MAXES AROUND 80 SOUTHEAST BUT REACH THE MID 80S ACROSS WESTERN SECTIONS. AGAIN THIS IS CLOSE TO MOS GUIDE. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... A SECOND UPPER LOW OVER GEORGIA TODAY WILL SLOWLY LIFT NORTH LATE TONIGHT AND MOVE ACROSS TO THE WEST OF THE AREA ON SUNDAY. THE UPPER LOW AGAIN WILL BE WEAKENING AS IT MERGES WITH THE WESTERLY TO THE NORTH. THIS THIS WILL HELP TO KEEP BEST CHANCES OF SHOWERS AND THUNDERSTORMS IN THE WESTERN AREAS TONIGHT AND SATURDAY. WITH THE HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL HAVE MOISTURE FEED OFF THE WATER COMING INTO THE AREA WITH SOME RISE TO THE EAST WINDS AS THEY APPROACH THE RIDGES TO THE WEST. BY MONDAY THIS FEATURE IS WEAKENING AND MORE NORTHEAST AWAY FROM THE AREA. HOWEVER WILL STILL HAVE PLENTY OF MOISTURE ACROSS THE AREA SO WILL CONTINUE CHANCE TO SLIGHT CHANCE POPS ESPECIALLY ON MONDAY AFTERNOON WITH THE BEST CHANCES IN THE WEST WHERE THE LOW LEVEL EAST WINDS WILL BEGIN TO RISE AS THEY APPROACH THE MOUNTAINS TO THE WEST. WILL GO FAIRLY CLOSE TO MOS GUIDANCE FOR TEMPERATURES WITH THE WARMEST DAY ON MONDAY AS LESS CLOUD COVER THEN. LOWS AT NIGHT WILL MAINLY BE IN THE MID TO UPPER 60S. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... PERIOD BEGINS WITH A BROAD MID/UPPER LEVEL RIDGE CENTERED OVER MUCH THE SOUTHERN TIER OF THE CONUS...GRADUALLY EVOLVING INTO A STRONG RIDGE OVER THE SW STATES WITH A FAIRLY DEEP TROUGH CENTERED JUST NORTH OF THE GREAT LAKES ACRS ONTARIO CANADA. THIS WILL TRANSLATE INTO A W/NW UPPER FLOW PATTERN INTO THE MID ATLC STATES. WHILE A SERIES OF WEAK SHORTWAVES BEGIN TO SHUNT THE RIDGE OFF TO THE S/SW OF THE CWA TUE/WED...TIMING THESE FEATURES IN THE MEDIUM RANGE IS QUITE DIFFICULT SO WILL GENLY HAVE ONLY A 20% CHANCE FOR MAINLY DIURNAL/AFTN/EVENING TSTMS TUE/WED. TEMPERATURES WILL WARM TO A LITTLE ABOVE AVG FOR LATE JUNE...MAINLY IN THE UPPER 80S TO LOWER 90S FOR HIGHS WITH LOWS IN THE UPPER 60S TO LOWER 70S. BY THU/FRI...A MORE DEFINED SFC BOUNDARY SETS UP NOT TOO FAR TO THE NORTH OF THE CWA...AND 500 MB HEIGHTS SLOWLY FALL...SO HAVE POPS HIGHER THAN CLIMO BOTH DAYS (ESPECIALLY FRI). HIGHS IN THE UPPER 80S TO LOWER 90S AND LOWS MAINLY FROM 70-75. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... MODELS CONT TO SHOW A PERSISTENT NE FLOW AHEAD OF APPROACHING SYSTEM FROM THE SOUTH. ANOTHER STRATUS LAYER DEVELOPING IN ASSOCIATION WITH REMNANT LLVL MOISTURE TRAPPED BELOW NOCTURNAL INVERSION. THIS WL LIKELY BRING ANOTHER NIGHT OF IFR VSBYS W/PATCHY FOG. AS LLVL MOISTURE CONTINUES TO INCREASE, EXPECT IFR TO BE A BIT MORE WIDESPREAD THIS MORNING THAN THE PREVIOUS TWO. ASIDE FROM THE FOG, EXPECT SHRAS TO PUSH NW FROM COASTAL CAROLINAS TOWARDS COASTAL TERMINALS, AND HV LEANED ON HRRR IN TAKING THE PARENT LOW AND THE ASSOCIATED PCPN SHIELD N-NW INTO NE NC AFTER 12Z THIS MORNING. PREDOMINATE -RA/SHRA NOW IN THE TAF AT PHF/ECG/ORF AFTER 13Z, EVENTUALLY REACHING RIC AFTER 15Z. DO EXPECT TO SEE SOME BREAKS IN STRATUS AT RIC/SBY AFTER 13-15Z, BUT HV GONE WITH VICINITY SHRA WORDING FOR SCT SHRAS THAT ARE EXPECTED TO DEVELOP BY ERY SAT AFTN IVOF RIC AS LOW PRESSURE SLOWLY WEAKENS TO OUR SOUTH. CIGS WL GENERALLY RANGE FROM MVFR TO VFR THROUGH THE AFTN OUTLOOK: MORE LATE NIGHT STRATUS IS EXPECTED LATE TONIGHT/SUN MORNING. OTHERWISE, EXPECT PREDOMINATE VFR CONDITIONS ASIDE FROM SCATTERED MAINLY DIURNALLY DRIVEN SHRAS SUN AND THROUGH MIDWEEK AS BREEZY S-SW FLOW REDEVELOPS MON-TUE. && .MARINE... LATEST OBS CONTINUE TO INDICATE ONSHORE (EAST) FLOW ACRS THE ENTIRE REGION. WINDS ARE GENLY 15 KT OR LESS (LIGHTEST OVER NORTHERN AREAS). SEAS CONTINUE TO SLOWLY SUBSIDE THIS MORNING, NOW AOB 4FT ACROSS THE MID-ATLANTIC WATERS. NO MAJOR CHANGES TO THE GOING FORECAST WITH THIS PACKAGE. MSAS 3-HR PRESSURE FALLS CONTINUES TO SHOW SLOW WEAKENING/SLACKENING OF THE PRESSURE GRADIENT BETWEEN THE INVERTED SFC TROUGH/LOW NEAR KILM AT 08Z AND HIGH PRESSURE OFF NORTHERN MID-ATLANTIC COAST. ACCORDINGLY, CONTINUE TO EXPECT CONDITIONS TO REMAIN SUB-SCA TODAY. STILL RATHER UNFAVORABLE BOATING CONDITIONS TODAY, WITH PREDOMINATE LLVL FLOW OUT OF THE E/NE FLOW AGAIN TODAY WITH SEAS 4 FT AND WAVES 2-3 FT AT THE MOUTH OF THE BAY. AS COASTAL FRONT PUSHES BACK WEST THIS AFTN/EVENING, EXPECT WINDS TO GRADUALLY VEER AROUND TO THE ESE, THEN THE SSE BY 06Z/2A SAT NIGHT/SUN MORNING WITH SPEEDS AOB 10 KT. THEREAFTER, GOOD MODEL AGREEMENT IN SETTING UP A RATHER STAGNANT, BUT FAIRLY BENIGN PATTERN FROM LATE SUN THROUGH THE MIDDLE OF NEXT WEEK. SSW WINDS WL AVERAGE AOB 15KT OUTSIDE OF ANY DEVELOPING AFTN/EVENING CONVECTION. WAVES 1-2 FT ON THE BAY/SND/RVRS...SEAS GENERALLY 2-4 FT (HIGHEST NORTHERN COASTAL WATERS). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR VAZ098>100. MARINE...NONE. && $$ SYNOPSIS...JAB NEAR TERM...JAB SHORT TERM...JAB LONG TERM...LKB AVIATION...MAM MARINE...MAM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
344 AM EDT SAT JUN 22 2013 .SYNOPSIS... A WEAK AREA OF LOW PRESSURE WILL LINGER ALONG THE NORTH CAROLINA COAST THROUGH TODAY. HIGH PRESSURE WILL BE ANCHORED OFF THE MID ATLANTIC COAST SUNDAY THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... INTERESTING FORECAST CHALLENGES TODAY. HAVE CONVECTION DEVELOPING ALONG A COASTAL FRONT OVER NORTH CAROLINA AND SLOWLY MOVING NORTH. THIS IS ASSOCIATED WITH A WEAK PV MAX ALOFT AND CAN BE SEEN ON WATER VAPOR. MEANWHILE HAVE A WEAK RIDGE OF HIGH PRESSURE ALOFT JUST TO THE NORTH OF THIS FEATURE. THIS HIGH IS SLOWLY WEAKENING AND MOVING TO THE EAST. THIS WILL ALLOW THE WEAK TROF TO LIFT NORTH TODAY. CAN SEE WINDS BECOMING MORE SOUTHEAST ALOFT ON VWP OBSERVATIONS AROUND THE AREA. THIS WILL ADVECT PLENTY OF MOISTURE INTO THE SOUTHERN PART OF THE CWA TODAY. WILL FOLLOW THE HRRR IDEA OF MOVING THE PRECIPITATION FROM NORTH CAROLINA INTO SOUTHEAST VIRGINIA DURING THE MORNING. COULD SEE SOME BRIEF HEAVY RAIN WITH SOME OF THE SHOWERS. BY THIS AFTERNOON THE MOISTURE WILL BE PULLED NORTH OVER MOST OF THE CWA. HOWEVER THE UPPER TROF WILL BE WEAKENING AND THIS WILL CAUSE THE PRECIPITATION TO MORE SCATTERED. THIS FOLLOWS THE NAM AND GFS. ALSO THE SREF SHOWS THE BEST CHANCES FOR PRECIP MOVING TO THE WESTERN SECTIONS OF THE CWA DURING THE AFTERNOON AND EVENING. SINCE WESTERN AREAS WILL BE SLOWER TO CLOUD UP WILL HAVE SOME MORE CAPE TO AIDE IN THUNDERSTORM DEVELOPMENT. AGAIN WITH PLENTY OF MOISTURE AROUND COULD SEE SOME BRIEF HEAVY DOWNPOURS. TEMPERATURES WILL BE DEPENDENT ON THE AMOUNT OF CLOUD COVER TODAY. EXPECT TO KEEP MAXES AROUND 80 SOUTHEAST BUT REACH THE MID 80S ACROSS WESTERN SECTIONS. AGAIN THIS IS CLOSE TO MOS GUIDE. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... A SECOND UPPER LOW OVER GEORGIA TODAY WILL SLOWLY LIFT NORTH LATE TONIGHT AND MOVE ACROSS TO THE WEST OF THE AREA ON SUNDAY. THE UPPER LOW AGAIN WILL BE WEAKENING AS IT MERGES WITH THE WESTERLY TO THE NORTH. THIS THIS WILL HELP TO KEEP BEST CHANCES OF SHOWERS AND THUNDERSTORMS IN THE WESTERN AREAS TONIGHT AND SATURDAY. WITH THE HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL HAVE MOISTURE FEED OFF THE WATER COMING INTO THE AREA WITH SOME RISE TO THE EAST WINDS AS THEY APPROACH THE RIDGES TO THE WEST. BY MONDAY THIS FEATURE IS WEAKENING AND MORE NORTHEAST AWAY FROM THE AREA. HOWEVER WILL STILL HAVE PLENTY OF MOISTURE ACROSS THE AREA SO WILL CONTINUE CHANCE TO SLIGHT CHANCE POPS ESPECIALLY ON MONDAY AFTERNOON WITH THE BEST CHANCES IN THE WEST WHERE THE LOW LEVEL EAST WINDS WILL BEGIN TO RISE AS THEY APPROACH THE MOUNTAINS TO THE WEST. WILL GO FAIRLY CLOSE TO MOS GUIDANCE FOR TEMPERATURES WITH THE WARMEST DAY ON MONDAY AS LESS CLOUD COVER THEN. LOWS AT NIGHT WILL MAINLY BE IN THE MID TO UPPER 60S. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... PERIOD BEGINS WITH A BROAD MID/UPPER LEVEL RIDGE CENTERED OVER MUCH THE SOUTHERN TIER OF THE CONUS...GRADUALLY EVOLVING INTO A STRONG RIDGE OVER THE SW STATES WITH A FAIRLY DEEP TROUGH CENTERED JUST NORTH OF THE GREAT LAKES ACRS ONTARIO CANADA. THIS WILL TRANSLATE INTO A W/NW UPPER FLOW PATTERN INTO THE MID ATLC STATES. WHILE A SERIES OF WEAK SHORTWAVES BEGIN TO SHUNT THE RIDGE OFF TO THE S/SW OF THE CWA TUE/WED...TIMING THESE FEATURES IN THE MEDIUM RANGE IS QUITE DIFFICULT SO WILL GENLY HAVE ONLY A 20% CHANCE FOR MAINLY DIURNAL/AFTN/EVENING TSTMS TUE/WED. TEMPERATURES WILL WARM TO A LITTLE ABOVE AVG FOR LATE JUNE...MAINLY IN THE UPPER 80S TO LOWER 90S FOR HIGHS WITH LOWS IN THE UPPER 60S TO LOWER 70S. BY THU/FRI...A MORE DEFINED SFC BOUNDARY SETS UP NOT TOO FAR TO THE NORTH OF THE CWA...AND 500 MB HEIGHTS SLOWLY FALL...SO HAVE POPS HIGHER THAN CLIMO BOTH DAYS (ESPECIALLY FRI). HIGHS IN THE UPPER 80S TO LOWER 90S AND LOWS MAINLY FROM 70-75. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... MODELS CONT TO SHOW A PERSISTENT NE FLOW AHEAD OF APPRCHG SYSTM FROM THE SOUTH. ANOTHER STRATUS LAYER DVLPNG IN ASSOCIATION WITH REMNANT LLVL MOISTURE TRAPPED BELOW NOCTURNAL INVERSION. THIS WL LIKELY BRING ANOTHER NIGHT OF IFR VSBYS W/PATCHY FOG. AS LLVL MOISTURE CONTINUES TO INCREASE, EXPECT IFR TO BE A BIT MORE WIDESPREAD THIS MORNING THAN THE PREVIOUS TWO. ASIDE FROM THE FOG, EXPECT SHRAS TO PUSH NW FROM COASTAL CAROLINAS TOWARDS COASTAL TERMINALS, AND HV LEANED ON HRRR IN TAKING THE PARENT LOW AND THE ASSOCIATED PCPN SHIELD N-NW INTO NE NC AFTR 12Z THIS MORNING. PREDOMINATE -RA/SHRA NOW IN THE TAF AT PHF/ECG/ORF AFTER 13Z, EVENTUALLY REACHING RIC AFTER 15Z. DO EXPECT TO SEE SOME BREAKS IN STRATUS AT RIC/SBY AFTER 13-15Z, BUT HV GONE WITH VICINITY SHRA WORDING FOR SCT SHWRS THAT ARE EXPECTED TO DEVELOP BY ERY SAT AFTN IVOF RIC AS LOW PRESSURE SLOWLY WEAKENS TO OUR SOUTH. CIGS WL GENERALLY RANGE FROM MVFR TO VFR THROUGH THE AFTN OUTLOOK: MORE LATE NIGHT STRATUS IS EXPECTED LATE TONIGHT/SUN MORNING. OTHERWISE, EXPECT PREDOMINATE VFR CONDITIONS ASIDE FROM SCATTERED MAINLY DIURNALLY DRIVEN SHRAS SUN AND THROUGH MIDWEEK AS BREEZY S-SW FLOW REDEVELOPS MON-TUE. && .MARINE... LATEST OBS CONTINUE TO INDICATE E/NE FLOW ACRS THE ENTIRE REGION. WINDS ARE GENLY 15 KT OR LESS (LIGHTEST OVER NORTHERN AREAS). SEAS CONTINUE TO SLOWLY SUBSIDE THIS MORNING, NOW AOB 4FT ACROSS THE MID-ATLANTIC WATERS. NO MAJOR CHANGES TO THE GOING FORECAST WITH THIS PACKAGE. MSAS 3-HR PRESSURE FALLS CONTINUES TO SHOW SLOW WEAKENING/SLACKENING OF THE PRESSURE GRADIENT BETWEEN THE INVERTED SFC TROUGH/LOW NEAR KILM AT 08Z AND HIGH PRESSURE OFF NORTHERN MID-ATLANTIC COAST. ACCORDINGLY, CONTINUE TO EXPECT CONDITIONS TO REMAIN SUB-SCA TODAY. STILL RATHER UNFAVORABLE BOATING CONDITIONS TODAY, WITH PREDOMINATE LLVL FLOW OUT OF THE E/NE FLOW AGAIN TODAY WITH SEAS 4 FT AND WAVES 2-3 FT AT THE MOUTH OF THE BAY. AS COASTAL FRONT, PUSHES BACK WEST, EXPECT WINDS TO GRADUALLY SHIFT TO THE ESE THEN THE SSE BY SAT NIGHT/SUN (AND SPEEDS WILL AVG AROUND 10 KT). GOOD MODEL AGREEMENT IN SETTING UP A RATHER STAGNANT, BUT FAIRLY BENIGN PATTERN FROM LATE SUN THROUGH THE MIDDLE OF NEXT WEEK WITH SSW WINDS AVERAGING 10-15 KT OUTSIDE OF ANY CONVECTION. 1-2 FT ON THE BAY/SND/RVRS...SEAS GENERALLY 2-4 FT (HIGHEST NORTHERN COASTAL WATERS). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR VAZ098>100. MARINE...NONE. && $$ SYNOPSIS...JAB NEAR TERM...JAB SHORT TERM...JAB LONG TERM...LKB AVIATION...MAM MARINE...MAM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
327 AM EDT SAT JUN 22 2013 .SYNOPSIS... A WEAK AREA OF LOW PRESSURE WILL LINGER ALONG THE NORTH CAROLINA COAST THROUGH SATURDAY. HIGH PRESSURE WILL BECOME ANCHORED OFF THE MID ATLANTIC COAST SUNDAY THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... SFC HIGH PRESSURE EXTENDS OVER THE REGION FROM THE NORTHEAST TONIGHT. MEANWHILE...AN INVERTED TROUGH/COASTAL FRONT REMAINS OFF THE CAROLINA COAST. NOT EXPECTING MORE THAN MAINLY ISOLD SHWRS ACROSS SERN AREAS OVRNGT WITH THE INVERTED TROUGH LINGERING OFF THE COAST. WE WILL HOWEVER SEE CLOUDS START TO INCREASE FATHER WEST INTO THE PIEDMONT AS EASTERLY FLOW DEEPENS. NUISANCE LOW STRATUS/PATCHY FOG WILL ALSO DEVELOP ACROSS THE SOUTHEAST. LOWS TONIGHT IN THE UPR 50S NW TO THE UPR 60S SERN COASTAL AREAS. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/... INVERTED TROUGH/COASTAL FRONT WILL LIFT NW AND WEAKEN ALONG THE NC COAST SATURDAY. BEST LOW-LEVEL MOISTURE STARTS TO SHIFT INLAND ACROSS SOUTH-CENTRAL VA AND NE NC...AND WE`LL ACTUALLY CARRY CHC POPS (40-45%) ACROSS THESE AREAS. DESPITE LIMITED FORCING...PWAT`S AROUND 2 INCHES AND MODEST INSTABILITY (CAPE 1000-1500 J/KG)WILL HELP GENERATE SOME AFTN THUNDERSTORMS WITH POTENTIAL FOR HEAVY DOWNPOURS. BECOMING MORE HUMID WITH HIGHS IN THE 80S...EXCEPT COOLER 70S IMMEDIATE COAST. PCPN WILL WANE WITH THE LOSS OF DAYTIME HEATING SATURDAY EVENING. LOWS SATURDAY NIGHT IN THE 60S. A RETURN TO A MORE TYPICAL SUMMERTIME PATTERN IS EXPECTED SUNDAY INTO MONDAY AS THE COASTAL BOUNDARY IS REPLACED BY BERMUDA HIGH PRESSURE. THERE WILL BE ENOUGH LINGERING MOISTURE FOR SCT AFTN CONVECTION BOTH DAYS...ESPECIALLY INLAND...AND WILL COVER THIS WITH 30% POPS. SEASONABLY WARM AND HUMID WITH HIGHS IN THE 80S TO AROUND 90...EXCEPT COOLER AT THE BEACHES. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... PERIOD BEGINS WITH A BROAD MID/UPPER LEVEL RIDGE CENTERED OVER MUCH THE SOUTHERN TIER OF THE CONUS...GRADUALLY EVOLVING INTO A STRONG RIDGE OVER THE SW STATES WITH A FAIRLY DEEP TROUGH CENTERED JUST NORTH OF THE GREAT LAKES ACRS ONTARIO CANADA. THIS WILL TRANSLATE INTO A W/NW UPPER FLOW PATTERN INTO THE MID ATLC STATES. WHILE A SERIES OF WEAK SHORTWAVES BEGIN TO SHUNT THE RIDGE OFF TO THE S/SW OF THE CWA TUE/WED...TIMING THESE FEATURES IN THE MEDIUM RANGE IS QUITE DIFFICULT SO WILL GENLY HAVE ONLY A 20% CHANCE FOR MAINLY DIURNAL/AFTN/EVENING TSTMS TUE/WED. TEMPERATURES WILL WARM TO A LITTLE ABOVE AVG FOR LATE JUNE...MAINLY IN THE UPPER 80S TO LOWER 90S FOR HIGHS WITH LOWS IN THE UPPER 60S TO LOWER 70S. BY THU/FRI...A MORE DEFINED SFC BOUNDARY SETS UP NOT TOO FAR TO THE NORTH OF THE CWA...AND 500 MB HEIGHTS SLOWLY FALL...SO HAVE POPS HIGHER THAN CLIMO BOTH DAYS (ESPECIALLY FRI). HIGHS IN THE UPPER 80S TO LOWER 90S AND LOWS MAINLY FROM 70-75. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... MODELS CONT TO SHOW A PERSISTENT NE FLOW AHEAD OF APPRCHG SYSTM FROM THE SOUTH. ANOTHER STRATUS LAYER DVLPNG IN ASSOCIATION WITH REMNANT LLVL MOISTURE TRAPPED BELOW NOCTURNAL INVERSION. THIS WL LIKELY RESULT IN ANOTHER NIGHT OF IFR VSBYS W/PATCHY FOG. AS LLVL MOISTURE CONTINUES TO INCREASE, EXPECT IFR TO BE A BIT MORE WIDESPREAD TONIGHT THAN THE PREVIOUS TWO. ASIDE FROM THE FOG, EXPECT SHRAS TO PUSH NW TOWARDS COASTAL ZONES, AND HV LEANED ON HRRR IN TAKING THE PARENT LOW AND THE ASSOCIATED PCPN SHIELD N-NW INTO NE NC AFTR 12Z. PREDOMINATE -RA/SHRA NOW IN THE TAF AT PHF/ECG/ORF AFTER 13Z. EXPECT SOME BREAKS IN STRATUS AT RIC/SBY AFTER 13-15Z, BUT HV GONE WITH VICINITY SHRA WORDING FOR SCT SHWRS THAT ARE EXPECTED TO DEVELOP BY ERY SAT AFTN IVOF RIC AS LOW PRESSURE SLOWLY WEAKENS TO OUR SOUTH. CIGS WL GENERALLY RANGE FROM MVFR TO VFR THROUGH THE AFTN OUTLOOK: MORE LATE NIGHT STRATUS IS EXPECTED LATE TONIGHT/SUN MORNING. OTHERWISE, EXPECT PREDOMINATE VFR CONDITIONS ASIDE FROM SCATTERED MAINLY DIURNALLY DRIVEN SHRAS SUN AND THROUGH MIDWEEK AS BREEZY S-SW FLOW REDEVELOPS MON-TUE. && .MARINE... LATEST OBS INDICATE E/NE FLOW PREVAILS ACRS THE ENTIRE REGION. WINDS ARE GENLY 15 KT OR LESS (LIGHTEST OVER NORTHERN AREAS). HAVE DECIDED TO KEEP SCA IN EFFECT THROUGH 7 PM OVER THE NC COASTAL WATERS FOR 4-5 FT SEAS (ALTHOUGH FOR THE MOST PART SEAS HAVE AVERAGED JUST BELOW 5 FT). ELSEWHERE...SEAS ARE 3-4 FT ON THE COASTAL WATERS, 1-2 FT ON THE BAY/SND/RVRS. MODELS GENLY FORECAST A SLOW WEAKENING OF THE PRESSURE GRADIENT BETWEEN THE INVERTED SFC TROUGH/LOW OFF THE NC/SC COAST AND HIGH PRESSURE OFF THE NJ COAST LATER TONIGHT INTO SAT...SO CONDITIONS SHOULD NE SUB-SCA THROUGHOUT. THE E/NE FLOW WITH SEAS 4 FT AND WAVES 2-3 FT AT THE MOUTH OF THE BAY WILL STILL TRANSLATE TO LESS THAN IDEAL BOATING CONDITIONS ACROSS THE LOWER BAY AND COASTAL WATERS INTO SAT AFTN HOWEVER. WINDS GRADUALLY SHIFT TO THE ESE THEN THE SSE BY SAT NIGHT/SUN (AND SPEEDS WILL AVG AROUND 10 KT). A RATHER STAGNANT, BUT FAIRLY BENIGN PATTERN IS EXPECTED TO TAKE SHAPE FROM LATE SUN THROUGH THE MIDDLE OF NEXT WEEK WITH SSW WINDS AVERAGING 10-15 KT OUTSIDE OF ANY CONVECTION. 1-2 FT ON THE BAY/SND/RVRS...SEAS GENERALLY 2-4 FT (HIGHEST NORTHERN COASTAL WATERS). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR VAZ098>100. MARINE...NONE. && $$ SYNOPSIS...JDM NEAR TERM...JDM/MAS SHORT TERM...JDM/TMG LONG TERM...LKB AVIATION...MAM MARINE...LKB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
747 PM EDT SUN JUN 23 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 418 PM EDT SUN JUN 23 2013 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER SE SASK INTO SRN MANITOBA WITH A SHORTWAVE TROUGH EXTENDING INTO ERN ND AND NW MN. AT THE SFC...A 999MB SFC LOW WAS LOCATED OVER THE NW CORNER OF MN WITH A WARM FRONT EXTENDING INTO SRN LAKE SUPERIOR. CLEARING AND AFTERNOON HEATING HAS PUSHED TEMPS INTO THE LOWER 80S OVER WRN UPPER MI RESULTING IN MLCAPE VALUES TO AROUND 1500 J/KG. SCT SHRA/TSRA WERE DEVELOPING OVER WRN LAKE SUPERIOR INTO NW UPPER MI CLOSEST TO THE FORCING ASSOCIATED WITH THE ND/MN SHRTWV. EXPECT THAT SCT SHRA/SHRA WILL CONTINUE TO DEVELOP BACK THROUGH WRN UPPER MI LATE THIS AFTERNOON AS A WEAK TROUGH MOVES INTO THE AREA...PER HIGH RES MODELS. INSTABILITY ALONG WITH 30-35 KT 0-6KM SHEAR AND 20-25 KT 0-1KM SHEAR COULD SUPPORT AT LEAST ISOLD STRONG/SEVERE STORMS...WITH STRONG WIND GUSTS AS THE MAIN HAZARD GIVEN DCAPE VALUES INTO THE 500-1000 J/KG RANGE. EXPECT THAT THE SHRA/TSRA WILL SPREAD INTO CNTRL UPPER MI BY 21Z-23Z AND THEN DISSIPATE AND WEAKEN BY LATE EVENING AS THE SHRA/TSRA MOVE TOWARD THE ERN CWA...AWAY FROM THE THE STRONGER INSTABILITY AND THE SHRTWV FORCING. AS THE SHORTWAVE AND LOW MOVE INTO NRN ONTARIO THE DRY SLOT AND STRONG MID LEVEL DRYING WILL SPREAD ACROSS THE REGION LATE TONIGHT INTO MONDAY. THIS WILL HELP MINIMIZE CHANCES FOR ADDITIONAL CONVECTION. WITH SUNSHINE AND 850 MB TEMPS STILL AROUND 15C...TEMPS WILL AGAIN CLIMB INTO THE LOWER 80S. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 418 PM EDT SUN JUN 23 2013 GENERAL AGREEMENT IN OVERALL LOOK OF LARGER SCALE PATTERN INTO NEXT WEEKEND THOUGH DETAILS AND SPECIFICS REMAIN UNCERTAIN. TO START ON MONDAY EVENING...FAIRLY STRONG SHORTWAVE TROUGH WILL BE HEADING EAST ACROSS NORTHERN ONTARIO LEAVING RIDGING IN ITS WAKE OVER NORTHERN PLAINS. SFC FRONT AND POOL OF SFC-H85 MOISTURE ALONG THE BOUNDARY DRIVES SOUTH OF CWA BY LATE MONDAY EVENING RESULTING IN GENERALLY QUIET AND LESS HUMID WEATHER INTO MUCH OF TUESDAY. GFS AND ECMWF AGREE HERE...WHILE THE GEM-NH AND THE UKMET DO NOT PUSH WARM FRONT FAR ENOUGH SOUTH TO KEEP CHANCES OF SHRA/TSRA OUT OF CWA. WILL LEAN ON THE MORE CONSISTENT ECMWF IDEA WHICH IS SUPPORTED BY WPC HAND DRAWN SFC MAP. WITH WARM FRONT AND EDGE OF SFC BASED-MUCAPE MOST LIKELY STILL SOUTH BY TUESDAY AFTN...WONDER IF MOST AREAS STAY DRY THROUGH TUESDAY. ANY SHRA/TSRA THAT FORM MONDAY NIGHT INTO TUESDAY MORNING SHOULD STAY SOUTH OF CWA PER H85-H3 THICKNESSES AND FORWARD PROPAGATING CORFIDI VECTORS AND EVEN THE MEAN LAYER WIND. INTO TUESDAY NIGHT...ECMWF AND GFS STILL HAVE SHORTWAVE CRASHING THROUGH TOP EDGE OF LARGER SCALE RIDGING. WAVE MAY AID IN BRINGING AT LEAST H85 FRONT FAR ENOUGH NORTH THAT SOUTHERN TIER COULD BE AFFECTED BY SHRA/TSRA TUESDAY NIGHT AND MUCH OF THE CWA COULD SEE SHRA/TSRA ON WEDNESDAY. GFS STRONGER WITH THIS WAVE SO MUCH THAT IT PUSHES SFC WARM FRONT INTO CWA ON WEDNESDAY. PV ANAMOLY THAT GFS CARRIES IN HERE ON WEDNESDAY TRACKS BACK TO SOUTH EDGE OF STRONG UPR LOW OVER THE ALLUTIANS THIS MORNING. WAVE LOOKS PRETTY VIGOROUS ON WV LOOP. ECMWF HAS BETTER TRACK RECORD IN THE EXTENDED...BUT WILL BLEND SOME OF THE GFS IDEA IN AS WELL SINCE IT SEEMS TO HAVE SOME MERIT. TROUGH AND HIGHER SFC-H85 DWPNTS PUSH THROUGH AREA WEDNESDAY EVENING AND COOLER AIR ARRIVES LATER ON THURSDAY. GFS QUICKER AND STRONGER AS WELL AS FARTHER SOUTH WITH SHORTWAVE TROUGH DIGGING ACROSS UPR LAKES ON THURSDAY WHILE THE ECMWF SHOWS MORE SEPARATION BTWN THE WAVE ON WEDNESDAY AND THAT STRONGER TROUGHING. GFS HAS TENDENCY TO BRING SYSTEMS IN TOO QUICKLY AND ITS SOLUTION VERIFYING AT 12Z THURSDAY HAS SHOWN TOO MUCH INCONSISTENCY TO PUT MUCH STOCK IN IT AT THIS POINT. ECMWF HAS TRENDED A BIT SHAPRER WITH TROUGH BUT OVERALL HAS BEEN MUCH MORE CONSISTENT THAN GFS. WILL PREFER THAT IDEA FOR NOW. RESULT WILL BE SCT SHRA/TSRA...MAYBE EVEN NMRS FOR A TIME WEDNESDAY OR WEDNESDAY EVENING...THEN DIMINISHING WITH LOSS OF INSTABILITY AXIS LATER WEDNESDAY NIGHT. POTENTIAL FOR ANOTHER ROUND OF SCT SHRA/TSRA DURING PEAK HEATING ON THURSDAY AS AIRMASS OVER THE REGION IS STILL A BIT UNSTABLE /MLCAPES UP TO 1000 J/KG/ WHILE WNW FLOW ALOFT INCREASES ON SOUTH EDGE OF UPPER TROUGH. LIGHT AND VARIABLE SFC WINDS COULD RESULT IN LAKE BREEZE CONVERGENCE AS WELL. ALWAYS HAVE TO WATCH OUT FOR WNW-NW FLOW ALOFT AS THAT PATTERN WITH SUFFICIENT INSTABILITY IS ONE THAT CAN RESULT IN AT LEAST SOME CHANCE OF SEVERE WEATHER. UPPER TROUGH DOMINATES ON FRIDAY WITH A BIT COOLER AND UNSETTLED WEATHER. NO TSRA EXPECTED ON FRIDAY AS COOLER TEMPS ALOFT/STEEPER LAPSE RATES SETUP FROM NORTHERN ONTARIO INTO THE LOWER GREAT LAKES. COULD BE SHRA AT TIMES THOUGH AS SMALLER SCALE SHORTWAVES ROTATE AROUND PRIMARY UPPER TROUGH. FRIDAY NIGHT INTO SATURDAY MAY BE KIND OF BLUSTERY ALONG LK SUPERIOR AND WITH ONSHORE WINDS SWIM RISK MAY BE HIGHER TO START THE WEEKEND. SMALL CHANCES OF SHRA MAY LINGER INTO SATURDAY AS WELL. TEMPS SOME AREAS FRIDAY INTO SATURDAY MAY END UP MORE THAN 10 DEGREES BELOW NORMAL. HIGH PRESSURE BUILDS IN FOR LATER IN THE WEEKEND...RESULTING IN TEMPS BOUNCING UP AT LEAST TOWARD NORMAL. NEXT SHORTWAVE IN WNW FLOW APPEARS LATE IN THE WEEKEND SO HAVE POPS MOVING BACK IN FOR LATE SUNDAY. NO REAL WARM TEMPERATURES SEEN NEXT WEEKEND OR EVEN INTO EARLY NEXT WEEK AS TROUGHING ALOFT OVER EASTERN CANADA AND GREAT LAKES KEEPS WARM AIR RESTRICTED TO WESTERN AND SOUTHERN PORTIONS OF CONUS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 747 PM EDT SUN JUN 23 2013 SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE NEAR KSAW THROUGH EARLY EVENING. OTHERWISE...EXPECT PRIMARILY VFR CONDITIONS THROUGH THE NIGHT. LATER THIS EVENING WITH ABUNDANT MOISTURE IN PLACE EXPECT SOME PATCHY FOG TO DEVELOP TOWARDS MORNING AT BOTH KCMX/KSAW AS HAS BEEN SEEN AT BOTH SITES THROUGH THE WEEK. DO NOT EXPECT EITHER SITE TO DROP BELOW MVFR IN TERMS OF VISIBILITY. OTHERWISE...EXPECT FAIRLY QUIET CONDITIONS THROUGH THE TAF PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 418 PM EDT SUN JUN 23 2013 WINDS SHOULD REMAIN 25 KTS OR LESS THROUGH THE UPCOMING WEEK. MAIN HAZARD WILL BE SCT THUNDERSTORMS TONIGHT AND FOG. DENSE FOG ADVISORIES HAVE BEEN EXTENDED THROUGH TONIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... DENSE FOG ADVISORY UNTIL 5 AM EDT /4 AM CDT/ MONDAY FOR LSZ162- 263>267. LAKE MICHIGAN... DENSE FOG ADVISORY UNTIL 8 AM EDT MONDAY FOR LMZ248-250. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...MCD MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 PM EDT SAT JUN 22 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 423 PM EDT SAT JUN 22 2013 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM ALBERTA INTO THE NRN ROCKIES AND A RIDGE OVER THE CNTRL GREAT LAKES RESULTING IN SW FLOW FROM THE PLAINS THROUGH THE UPPER MS VALLEY. THE MOST PROMINENT UPSTREAM SHORTWAVE TROUGH WAS MOVING THROUGH WRN WYOMING. WIDESPREAD LOW LEVEL MOISTURE AND CLOUDS PREVAILED NORTH OF A WARM FRONT EXTENDING FROM SE MN THROUGH CNTRL WI. TO THE SOUTH OF THE FRONT...TEMPS OVER ERN IA HAD CLIMBED INTO THE MID AND UPPER 80S WITH DEWPOINTS INTO THE LOWER 70S. TONIGHT...AS THE MID LEVEL RIDGE BUILDS TO THE EAST...THE SW FLOW PATTERN WILL ALLOW THE SFC-850 MB WARM FRONT TO PUSH TO THE NORTH. ALTHOUGH CONVECTION IS EXPECTED TO REDEVELOP ALONG OR AHEAD OF THE WARM FRONT THIS EVENING.....UNCERTAINTY WITH THE TIMING/POSITION OF ANY UPSTREAM SHRTWVS AND THE EVOLUTION OF CONVECTION IS HIGH. WITH THE FOCUS FOR MOISTURE/LOW LEVEL THETA-E ADVECTION SHIFTING FROM THE UPPER MS VALLEY TOWARD THE CWA...POPS INCREASE INTO THE WRN CWA AND ACROSS UPPER MICHIGAN BUT ARE STILL LIMITED TO CHANCE CATEGORY. SINCE MUCAPE VALUES ARE ONLY EXPECTED IN THE 400-800 J/KG RANGE...ONLY ISOLD TSRA WERE MENTIONED. POTENTIAL FOR STRONG OR SEVERE STORMS SHOULD REMAIN FARTHER SOUTH NEAR THE GREATER INSTABILITY. SUNDAY...AS THE WY SHRTWV LIFTS INTO THE NRN PLAINS A STRENGTHENING SFC LOW OVER THE ERN DAKOTAS WILL BRING INCREASING SRLY FLOW INTO THE WRN LAKES AND SHOULD FINALLY PUSH THE WARM FRONT NORTH OF UPPER MI. HOWEVER...CINH WILL ALSO INCREASE WITH 700 MB TEMPS INTO THE 10C-12C RANGE. SO...TEMPS WILL CLIMB WELL ABOVE NORMAL INTO THE MID/UPPER 80S AND CONVECTION POTENTIAL WILL BE LIMITED OVER THE CNTRL AND EAST. HOWEVER...SHRA/TSRA WILL INCREASE AGAIN BY MIDDAY SUN INTO SUN AFTERNOON AS MODELS CONTINUE TO SUGGEST A WEAK SHRTWV/IMPULSE COULD BRUSH MAINLY THE WRN CWA. MLCAPE VALUES INTO THE 1500-2000 J/KG RANGE COMBINED WITH 0-6KM SHEAR VALUES IN THE 30-40 KT RANGE COULD SUPPORT SOME STRONGER AND POSSIBLY SEVERE STORMS. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 423 PM EDT SAT JUN 22 2013 UPPER AIR PATTERN SUNDAY NIGHT INDICATES A DEEPER TROUGH LIFTING INTO SCNTRL CANADA WITH RIDGING CENTERED OVER OHIO VALLEY. SFC WARM FRONT SHOULD BE VCNTY OF UPR MICHIGAN/LK SUPERIOR. H85 FRONT ALSO SHOULD BE MAINLY NORTH OF CWA. FORECAST WILL ASSUME THAT IS GOING TO BE THE CASE AS LAST COUPLE DAYS...SFC WARM FRONT HAS REMAINED FARTHER SOUTH THAN FORECAST THANKS TO TSRA AND ASSOCIATED RAIN COOLED OUTFLOW. DO THINK FRONT WILL HAVE BETTER SHOT OF MAKING IT NORTH OF UPR MICHIGAN BY SUNDAY NIGHT DUE TO SW FLOW AHEAD OF STRONGER SHORTWAVE ALOFT. BASED ON INITIAL FOCUS REGION FOR SHRA/TSRA AND H7 WINDS/FORWARD PROPAGATING CORFIDI VECTORS AND 850-300MB THICKNESS...EXPECT CHANCES OF SHRA/TSRA SUNDAY NIGHT TO MAINLY BE OVER WESTERN THIRD OF UPR MICHIGAN AND ACROSS LK SUPERIOR ON EDGE OF H7 CAPPING TIED TO ELEVATED MIXED LAYER /EML/. AS MENTIONED IN SHORT TERM DISCUSSION...BASED ON AVAILABLE INSTABILITY AND DEEP LAYER SHEAR...THERE WILL BE POTENTIAL FOR STRONG OR SEVERE STORMS SUNDAY EVENING OVER THE WEST. NAM/ECMWF FITS THIS EXPECTATION THE BEST WHILE THE GEM-NH AND GFS SEEM TO SHOW QPF TOO FAR EAST INTO THE CAPPED AREA. THOSE IDEAS WOULD HAVE BETTER CHANCE OF VERIFYING IF THE SFC-H85 FRONTS END UP FARTHER SOUTH THAN FORECAST. CHANCES FOR SHRA/TSRA ON MONDAY LIKELY HIGHEST DURING THE MORNING AND HIGHEST OVER THE EASTERN CWA ON EDGE OF CAPPING THAT WILL BE BEING SHUNTED TO THE EAST AND SOUTH AT THAT TIME AS H85 WINDS VEER MORE WESTERLY. WILD CARD FOR MONDAY IS IF TAIL OF SHORTWAVE AND ASSOCIATED HEIGHT FALLS MOVING ACROSS NORTHERN LK SUPERIOR ARE SUFFICIENT ENOUGH TO TRIGGER OTHER SHRA/TSRA ON EDGE OF CAPPING AND MUCAPE GRADIENT JUST UPSTREAM AND/OR JUST SOUTH OF UPR MICHIGAN. A PRETTY LOW CHANCE OF THIS...BUT IF IT WOULD HAPPEN THEN THERE IS POSSIBILITY OF SHRA/TSRA COMPLEX IMPACTING PARTS OF CWA ON MONDAY MORNING. INTO MONDAY AFTN...WIND FIELD BECOMES GENERALLY LIGHT AND VARIABLE WHICH OPENS DOOR FOR LK BREEZE SHRA/TSRA OVER MAINLY CNTRL UPR MICHIGAN /MQT-ESC-P53/. KEPT A SMALL POP IN THERE. WOULD BE VERY LOW CHANCE IF THERE IS MORE FORMIDABLE CONVECTION AROUND MONDAY MORNING AS SUBSIDENCE LATER IN THE DAY WOULD LIKELY PUT CAP ON ANY ADDITIONAL SHRA/TSRA. HIGHS ON MONDAY COULD SURGE INTO THE LOW-MID 80S OVER SCNTRL BUT SHOULD STAY IN THE MID-UPR 70S ELSEWHERE. WILL BECOME INCREASINGLY LESS HUMID LATER MONDAY AFTN OVER WESTERN UPR MICHIGAN. DEVELOPING ONSHORE FLOW IN AFTN MAY RESULT IN SOME FOG IN IMMEDIATE LK SUPERIOR SHORELINE AREAS EAST OF MQT. GOING TO GO FOR PERIOD OF QUIET WEATHER MONDAY NIGHT AND FOR MOST OF TUESDAY AS WELL. SFC-H85 FRONTAL BOUNDARIES AND ASSOCIATED SHRA/TSRA LOOK TO SETTLE WELL TO SOUTH OF CWA MONDAY EVENING. OTHER THAN WEAKER SHORTWAVES TRAVELLING THROUGH GENERAL FLAT RIDGING ALOFT...THERE REALLY IS NOT A STRONG ENOUGH FEATURE TO BRING THE FRONTS BACK TO THE NORTH. EXPECT SHRA/TSRA TO STAY OVER SOUTHERN HALF OF MN AND WI MONDAY NIGHT INTO TUESDAY MORNING. PERHAPS ISOLD SHRA/TSRA MAKE INTO TO THE WI BORDER LATE TUESDAY AFTN/EVENING AS SFC-H85 FRONTS TRY TO LIFT BACK TO THE NORTH OUT AHEAD OF LARGER SCALE TROUGHING MOVING ACROSS SCNTRL CANADA. ON THE OTHER HAND...MAYBE THIS NEXT ROUND OF SHRA/TSRA REMAINS MAINLY TO THE SOUTH OF UPR MICHIGAN SINCE SFC FRONT/MORE ABUNDANT INSTABILITY STAYS TO THE SOUTH. TOUGH TO SAY REALLY AS AT THE SAME TIME...H7 TEMPS PROGGED TO SURGE UPWARD AS CAPPING BUILDS JUST TO THE SOUTH OF UPR MICHIGAN. KEPT POPS CHANCE ALL AREAS...WITH HIGHEST CHANCES CONFINED TO SOUTH CENTRAL UPR MICHIGAN. KEPT SIMILAR IDEA GOING WEDNESDAY AS WELL WITH HIGHEST POPS ALONG WI BORDER INTO SCNTRL UPR MICHIGAN. WENT WITH MORE BROADBRUSHED APPROACH TO POPS WEDNESDAY NIGHT INTO THURSDAY AS COLD FRONT PRESSES IN FROM MANITOBA/ONTARIO AHEAD OF DEEPER UPR LEVEL TROUGH THAT DIGS INTO UPR LAKES REGION THURSDAY NIGHT INTO FRIDAY. WARM AND HUMID AIRMASS EXITS TO THE EAST BY THURSDAY NIGHT. HIGH TEMPS FOR FRIDAY AND NEXT SATURDAY SHOULD END UP BLO NORMAL ALL AREAS. COULD SEE CHANCES OF MAINLY RAIN SHOWERS /NO TSRA/ AS UPR TROUGH SETTLES ACROSS THE AREA. GUSTY NORTHWEST WINDS LIKELY AS WELL ALONG LK SUPERIOR ON FRIDAY AS THE COOLER AIR ARRIVES. PATTERN WILL FAVOR POTENTIAL FOR INCREASED SWIM RISK ON THE LAKE SUPERIOR BEACHES FOR FRIDAY. ARRIVAL OF THE COOLER AND DRIER AIRMASS SHOULD FINALLY SCOUR OUT THE FOG ON LK SUPERIOR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 155 PM EDT SAT JUN 22 2013 WITH ABUNDANT LOW-LEVEL MOISTURE LINGERING OVER THE REGION NORTH OF A WARM FRONT...EXPECT LOWER CIGS TO PEVAIL THIS AFTERNOON. UPSLOPE ENE FLOW INTO SAW WILL KEEP LIFR/IFR CONDITIONS IN PLACE TIL LATE THIS AFTERNOON WHEN DAYTIME HEATING/MIXING HELPS BRING IMPROVEMENT INTO THE MVFR RANGE. LOSS OF DAYTIME HEATING AND CONTINUED COOL EASTERLY UPSLOPE FLOW SHOULD BRING A RETURN OF FOG/LIFR CONDITIONS TO KCMX IN THE EVENING. DOWNSLOPE SE FLOW SHOULD MAY KEEP MVFR CONDITIONS AT KIWD INTO THE EVENING. AS FOR PCPN...SHRA/TSRA POTENTIAL IS VERY UNCERTAIN AND IS EXPECTED TO BE MORE SCT OR ISOLD IF ANY DEVELOPS LATE THIS AFTERNOON OR EVENING. CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE MENTION IN THE TAF AT THIS ISSUANCE. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 423 PM EDT SAT JUN 22 2013 WINDS SHOULD REMAIN 25 KTS OR LESS THROUGH THE UPCOMING WEEK. MAIN HAZARDS FOR MOST OF THE TIME WILL CONTINUE TO BE THUNDERSTORMS AND FOG. DENSE FOG ADVISORIES HAVE BEEN EXTENDED INTO SUNDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... DENSE FOG ADVISORY UNTIL 10 AM EDT /9 AM CDT/ SUNDAY FOR LSZ162- 240>250-263>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...JLB MARINE...JLA
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
201 AM EDT SAT JUN 22 2013 .AVIATION... //DISCUSSION... THE QUESTION ON WHAT WILL BECOME OF THE CONVECTION OVER SOUTHERN WISCONSIN IS THE MAIN FOCUS FOR THE TAFS THIS MORNING. THE UPSTREAM THUNDERSTORM ACTIVITY SEEMS TO BE FOCUSING ON EDGE OF CAP (SEE 00Z KDVN RAOB) FORCED BY LOCALIZED CVA. THE SHORTWAVE ENERGY IS A RECYCLED CONVECTIVE VORT MAX THAT HAS EMERGED FROM THE SOUTH. COLUMN MEAN FLOW OVER SOUTHERN WISCONSIN IS ACTUALLY QUITE WEAK AS THE LOW LEVEL JET IS WEAK WITHIN THE UPPER LEVEL RIDGE. CORFIDI VECTORS THROUGH MUCH OF THE MORNING ARE FROM THE EAST WHICH CORRESPONDS WELL TO THE BACKBUILDING BEHAVIOR SEEN RECENTLY. THIS LEAVES SERIOUS DOUBT IN POTENTIAL FOR THUNDERSTORMS TO MIGRATE EASTWARD INTO SOUTHEASTERN MICHIGAN. NEVERTHELESS..00Z KDTX RAOB SUGGESTS THAT EFFERVESCING WEAK CONVECTION MAY BE POSSIBLE THIS MORNING OVER THE NORTHERN CWA WITH NOTHING MORE THAN A MODEST INCREASE IN MOISTURE AND ASSOCIATED CLOUD TOP COOLING. FOR NOW WILL MAINTAIN FORECAST CONTINUITY AND CONVERT PROB30 TO TEMPO. AT KDTW...QUIET WEATHER IS EXPECTED THROUGH THE MORNING HOURS. ANY SHOWER OR THUNDERSTORM ACTIVITY THAT DEVELOPS IS EXPECTED TO REMAIN NORTH OF THE DETROIT METRO AREA CLOSER TO THE MOISTURE GRADIENTS. //DTW THRESHOLD THREATS... * LOW CONFIDENCE FOR A BRIEF PERIOD OF CEILINGS AT 5KFT SATURDAY MORNING. * LOW CONFIDENCE IN THUNDERSTORMS SATURDAY AFTERNOON. && .PREV DISCUSSION...ISSUED 958 PM EDT FRI JUN 21 2013 UPDATE... CLOUD SHIELD FROM THE LONG-LIVED MCS...NOW POSITIONED OVER SW INDIANA WHITTLING INTO THE DEEP INSTABILITY RESERVOIR...HAS QUICKLY DISSIPATED OVER SOUTHEAST MICHIGAN IN THE BROAD UPPER- LEVEL ANTI-CYCLONIC FLOW. RETURN DEEP THETA-E ADVECTION IS ALREADY EVIDENT...IN THE FORM OF FRESH SHOWER DEVELOPMENT...NEAR LAKE MICHIGAN. THIS INITIAL FEATURE IS EXPECTED TO SLIDE EAST AND SLOWLY WASH OUT IN THE POST-MIDNIGHT HOURS. WHILE THIS OCCURS GREATER THETA-E ADVECTION IN THE 925-850MB LAYER...OWING FROM AN INCREASING NOCTURNAL LOW-LEVEL JET...WILL FILTER INTO THE LOWER PENINSULA LATE TONIGHT. LATEST RAP SOLUTIONS INDICATE 0-1KM MLCAPE VALUES CLIMBING TO NEAR 1KJ/KG BY DAYBREAK AND INCREASE FROM THERE THROUGH THE MORNING HOURS. THE SHARP INSTABILITY GRADIENT WILL QUICKLY TAKE RESIDENCE ACROSS AREAS ALONG AND NORTH OF I-69. EXPECT NEW CONVECTION TO CONTINUE TO CYCLE ALONG THE SURGE OF INSTABILITY ACROSS WISCONSIN AND WESTERN LOWER MICHIGAN AS WARM FRONTAL DYNAMICS WILL AID IN FORCING ASCENT. FARTHER UPSTREAM ORGANIZED CONVECTION SHOULD CONTINUE ALONG THE SHARP INSTABILITY GRADIENT OVER SOUTHEAST MINNESOTA AND CENTRAL WISCONSIN. EXPECT SOME OF THIS ACTIVITY TO CHURN EAST ALONG THE WELL DEFINED INSTABILITY GRADIENT THROUGHOUT THE NIGHT AND INTO SATURDAY MORNING. PREV DISCUSSION...ISSUED 347 PM EDT FRI JUN 21 2013 SHORT TERM...TONIGHT SOUTHEAST MICHIGAN REMAINS ON THE OUTER FRINGE OF THE UPPER LEVEL RIDGE CENTERED OVER MISSOURI (SECOND RIDGE CENTER OVER MID ATLANTIC)...WHICH MAKES FOR A DIFFICULT FORECAST AS 500 MB HEIGHT HOVERS AROUND THE NORMALLY CRITICAL VALUE OF 588 DAM. NONE-THE-LESS...700 MB TEMPS REMAIN BELOW 10 C THROUGH TONIGHT...WHICH SUGGEST ACTIVITY IS POSSIBLE/NOT FULLY CAPPED. THE MASSIVE AND LONG LIVED MCS WHICH DEVELOPED OVER THE WESTERN GREAT LAKES THIS MORNING CONTINUES TO WEAKEN...WITH REMNANT 500 MB LOW/TROUGH TRACKING THROUGH NORTHERN LOWER MICHIGAN EARLY THIS EVENING. LATEST RADAR TRENDS SUGGEST A FEW SHOWERS AND POSSIBLE THUNDERSTORMS MAY SURVIVE THE TRIP ACROSS THE STATE...AS THERE IS SOME MODEST CAPES (SB CAPES OF 1000 J/KG)/INSTABILITY THE RAIN COOLED AIRMASS WILL BE MOVING INTO. ON THE FLIP SIDE...DEW PTS ARE MIXING DOWN INTO THE 50S ACROSS NORTHERN INDIANA/NW OHIO AND INTO PARTS OF SOUTHERN LOWER MICHIGAN...INDICATIVE OF THE 850-700 MB THETA-E TROUGH ASSOCIATED WITH THE RIDGE CENTER OVER THE MID ATLANTIC STATES...AND THUS THE DIRECTION THE FORECAST IS SKEWED WITH JUST SLIGHT CHANCE POPS SOUTH TO CHANCE POPS NORTH. THE QUESTION THEN BECOMES WHAT TO DO WITH TONIGHT...AS WISCONSIN LOW TRACKS NORTHEAST...ALLOWING FOR A DECENT 850 MB JET OF 40+ KNOT TO SET UP OVER NORTHERN LOWER MICHIGAN THIS EVENING. GOOD DESTABILIZATION TO REDEVELOP OVER THE WESTERN GREAT LAKES...WITH ANOTHER MCS DEVELOPING OVER THE EASTERN DAKOTAS THIS AFTERNOON...AND IT CERTAINLY IS POSSIBLE THIS COMPLEX WILL ARRIVE IN A WEAKENED STATE OVER LOWER MICHIGAN LATER TONIGHT...DESPITE THE 12Z NAM INDICATING DISSIPATION OVER WISCONSIN THIS EVENING. EVEN IF THIS DOES NOT OCCUR...STILL A CHANCE THE LOW LEVEL JET WILL TRIGGER A FEW SHOWERS/THUNDERSTORMS WITH MOISTURE AXIS MOVING OVERHEAD...ESPECIALLY AS ONE HEADS NORTH TOWARD SAGINAW BAY...CLOSER TO THE REMNANT WEAK FRONTAL BOUNDARY AND BETTER MOISTURE TRANSPORT. WITH INCREASING LOW LEVEL MOISTURE...MINS IN THE 60S ARE EXPECTED. LONG TERM... SATURDAY THROUGH FRIDAY EVOLUTION OF CONVECTION OVER THE MIDWEST AND GREAT LAKES REMAINS THE PRIMARY FORECAST CHALLENGE THROUGH THE WEEKEND AS A MID SUMMER AIR MASS SPREADS OVER THE REGION. SATELLITE IMAGERY AND MODEL ANALYSIS FIELDS INDICATE THE CONVECTIVE COMPLEX FROM THIS MORNING YIELDED A SUBSTANTIAL MCV NOW OVER THE NORTHERN GREAT LAKES BUT WHICH WILL MOVE EAST IN TIME FOR EITHER THE ONGOING NORTHERN PLAINS CONVECTION TO MOVE EASTWARD OR FOR A NEW ROUND OF NOCTURNAL DEVELOPMENT OVER THE UPPER MIDWEST TONIGHT. THE GENESIS REGION WILL BE FARTHER EAST COMPARED TO LAST NIGHT, MIGRATING WITH THE LARGE SCALE SURFACE TROUGH FROM THE NORTHERN PLAINS/DAKOTAS INTO MINNESOTA/NORTHERN WISCONSIN. EXPECT A RESURGENT LOW LEVEL JET TO FORCE NEW CONVECTION BY LATE THIS EVENING, OR SUPPORT THE ONGOING STORMS MOVING IN FROM THE DAKOTAS, EITHER OF WHICH WILL HAVE A CHANCE TO REACH CENTRAL/SE MICHIGAN DURING SATURDAY MORNING. INITIATION/PERSISTENCE OF EVENING CONVECTION WILL BE FAVORED ALONG EDGE OF THE MID LEVEL CAP, SUPPORTED BY OBSERVATIONS TO BE ROUGHLY IN THE 8-10C RANGE AT 700 MB AND AROUND 18C AT 850 MB. THIS, ALONG WITH A WESTERLY MEAN FLOW WILL SET UP A GENERAL WEST TO EAST DEVELOPMENT OF STORMS INTO SATURDAY MORNING. LOWER MICHIGAN WILL BE MORE RECEPTIVE TO MCS PERSISTENCE BY THEN DUE TO INCREASED POTENTIAL INSTABILITY IN THE WARM SECTOR OVER THE REGION, AT LEAST COMPARED TO THIS MORNING, BUT WITH THE INSTABILITY AXIS GENERALLY WEAKENING FROM WEST TO EAST OVER THE GREAT LAKES. THE KEY TO COVERAGE IN SE MICHIGAN MIGHT BE TIED TO THE INSTABILITY GRADIENT/CAP TAKING ON MORE OF WEST TO EAST CONFIGURATION AS THE WARM FRONT MOVES INTO THE NORTHERN GREAT LAKES, WHICH FAVORS THE TRI CITIES AND NORTHERN THUMB WITH THE GREATEST CHANCE OF STORMS. SEVERE WEATHER POTENTIAL REMAINS ON THE LOW SIDE AS A MATURE COMPLEX WILL BE POSSIBLE BUT, AS MENTIONED ABOVE, EXPECTED TO BE MOVING INTO WEAKER ENVIRONMENT OF INSTABILITY AND MID LEVEL LAPSE RATES. BULK SHEAR IN THE 0-6 KM LAYER IS ALSO UNFAVORABLE AT GENERALLY LESS THAN 20 KNOTS AS THE LARGER SCALE RIDGE BUILDS OVER THE REGION. CONDITIONS WILL BECOME INCREASINGLY CAPPED FOR THUNDERSTORM ACTIVITY DURING SATURDAY AFTERNOON THROUGH SUNDAY. AFTER NOCTURNAL CONVECTION EXITS/DISSIPATES SATURDAY MORNING, MODERATE SOUTHWEST LOW LEVEL FLOW WILL DISSIPATE ANY LINGERING OUTFLOW BOUNDARIES AND WORK AGAINST LAKE BREEZE FORMATION/INLAND PENETRATION. ALL OF THIS WILL OCCUR AS THE UPPER LEVEL RIDGE BUILDS OVER LOWER MICHIGAN AND REINFORCES WARM AIR THROUGH THE MID LEVELS. THE NEW 12Z RUNS ARE IN GOOD GENERAL AGREEMENT ON THE CHARACTER OF THE RIDGE WITH 500 MB HEIGHT BUILDING INTO THE 588-591 RANGE BY SATURDAY NIGHT INTO SUNDAY. THIS WILL SUPPORT THE RECENTLY ADVERTISED HEAT AND HUMIDITY FOR THE REST OF THE WEEKEND. SURFACE DEWPOINT PUSHING 70F WILL BOOST HEAT INDEX INTO THE LOWER 90S SATURDAY AFTERNOON AND TOWARD THE MID 90S SUNDAY WITH GREATER CONFIDENCE THAT CLOUD COVER WILL HAVE MINIMAL IMPACT ON AFTERNOON MAX TEMPS. THE LARGE SCALE PATTERN WILL SUPPORT PERSISTENCE OF WARM AND HUMID CONDITIONS INTO NEXT WEEK. THE MAIN SOURCE OF FORECAST UNCERTAINTY DURING MONDAY AND TUESDAY WILL BE WITH THE EVOLUTION OF A WEAK UPPER LEVEL CIRCULATION NOW OVER THE SOUTHEAST STATES. GLOBAL MODELS INDICATE THIS FEATURE SLOWLY DRIFTING INTO THE WESTERLIES AS A NEW SHORT WAVE SLIDES INTO NORTHERN ONTARIO. THE ABSORPTION OF THE UPPER CIRCULATION OVER THE EASTERN GREAT LAKES WILL COMBINE WITH THE POTENTIAL FOR A DECAYING FRONTAL BOUNDARY TO SETTLE OVER THE REGION AND REQUIRE A CONTINUED CHANCE MENTION OF SHOWERS AND STORMS. THERE REALLY IS NO CONVINCING MODEL SOLUTION THAT OFFERS A SIGNIFICANT CHANGE OF AIR MASS DURING THE SECOND HALF OF NEXT WEEK UNTIL PERHAPS FRIDAY. THE LONG WAVE PATTERN IS SHOWN TO RETROGRADE ENOUGH BY THEN AND OPEN THE DOOR ON A CANADIAN AIR MASS HEADING INTO NEXT WEEKEND. MARINE... GENERALLY LIGHT SOUTHERLY WINDS WILL CONTINUE THROUGH THE WEEKEND...LEADING TO UNSTABLE ATMOSPHERIC CONDITIONS WHICH COULD TRIGGER THUNDERSTORMS FROM TIME TO TIME. OUTSIDE OF THUNDERSTORM ACTIVITY, HIGHLY STABLE CONDITIONS CREATED BY THE WARM AIR OVER THE COOL LAKE WATER WILL MAINTAIN A MUTED RESPONSE TO THE WAVE GROWTH. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....CB UPDATE.......MANN SHORT TERM...SF LONG TERM....BT MARINE.......SF YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DULUTH MN
917 AM CDT SAT JUN 22 2013 .UPDATE... WE UPDATED GRIDS FOR THE SHORT TERM TO ACCOUNT FOR LATEST RADAR TRENDS. WE REDUCED POPS OVER THE NEXT COUPLE HOURS...BUT DO EXPECT INCREASING COVERAGE AS THE DAY PROGRESSES. LATEST SPC OUTLOOK REDUCED THE NORTHWARD EXTENT OF THE SLIGHT RISK AREA FOR SEVERE STORMS. GIVEN HOW FAR SOUTH THE WARM FRONT IS ATTM...WE AGREE WITH THAT MOVE. ALTHOUGH SOME STRONGER STORMS MAY STILL OCCUR OVER THE CWA THIS AFTERNOON. WE ALSO HAVE CONCERNS THAT SOME STRONGER STORMS MAY ARRIVE TONIGHT AS THE FRONT TRIES TO MOVE NORTH AGAIN AND WITH AN INCREASING LLJ. A QUICK LOOK AT THE LATEST NAM REVEALS INCREASING INSTABILITY AND DEEP LAYER SHEAR OVERNIGHT...SO STRONG TO POSSIBLY SEVERE STORMS MAY ALSO BE POSSIBLE LATE TONIGHT...MAINLY OVER THE SOUTHERN HALF OF THE CWA. THE VISIBILITY HAS RISEN IN SILVER BAY...GRAND MARAIS...ASHLAND AND IRONWOOD THIS MORNING. IF THESE TRENDS HOLD...WE MAY BE ABLE TO DROP THE DENSE FOG ADVISORY FOR PORTIONS OF THE NORTH AND SOUTH SHORES. THE ONSHORE FLOW IS STRONGER IN THE TWIN PORTS AREA...SO FOG SHOULD REMAIN HERE THE LONGEST. && .PREV DISCUSSION... /ISSUED 701 AM CDT SAT JUN 22 2013/ AVIATION...12Z TAF ISSUANCE... LOW PRESSURE SYSTEM OVER SWRN MN AND ERN NEB WILL CONTINUE TO SPREAD SHOWERS AND STORMS THROUGH THE REGION TODAY AND TONIGHT. THE EXACT TIMING AND PLACEMENT OF PRECIP WILL BE DIFFICULT TO NAIL DOWN...SO KEPT WITH VCSH LATE MORNING AND AFTERNOON...AND ANOTHER ROUND OF SHOWERS LATE TONIGHT. HAVE FOG THIS MORNING AT DLH LIFTING BY 15/17Z...BUT KEEPING LOW CLOUDS IN THROUGH MOST OF THE DAY AND FOG RETURNING TONIGHT. E/NE WINDS WILL BECOME GUSTY THIS AFTERNOON. PREV DISCUSSION... /ISSUED 409 AM CDT SAT JUN 22 2013/ SHORT TERM...TODAY THROUGH SUNDAY. THE FOCUS FOR TODAY THROUGH SUNDAY WILL CONTINUE TO BE PCPN POTENTIAL...AS WELL AS THE CONTINUED POTENTIAL FOR FOG AND DRIZZLE. PORTIONS OF THE CWA ARE ALSO IN THE SLIGHT RISK FOR SEVERE WEATHER TODAY AND TONIGHT. AT 330 AM...IT WAS ESSENTIALLY DRY ACROSS THE NORTHLAND. THERE WERE A FEW LIGHT SHOWERS NORTH OF THE IRON RANGE...AND ALSO IN NW WI. WIDESPREAD SHOWERS AND THUNDERSTORMS CONTINUED FROM EASTERN SOUTH DAKOTA...THROUGH CENTRAL AND SOUTHERN MN AND SOUTHERN WI WITH WIDESPREAD MCS ACTIVITY IN THOSE AREAS. DENSE FOG CONTINUED NEAR LAKE SUPERIOR AND HAVE ISSUED A DENSE FOG ADVISORY FOR LAND AND WATER AREAS. THE BIG QUESTION IS THE EVOLUTION OF THE WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE SOUTH OF THE AREA. AS EXPECTED WITH THIS TYPE OF PATTERN...THE MODELS REALLY DO NOT HAVE A HANDLE ON THE CURRENT PRECIPITATION. THERE ARE A FEW EXCEPTIONS...INCLUDING THE 4 KM WRF AND THE 06Z HRRR RAPID REFRESH. BOTH HAVE A RELATIVELY DECENT HANDLE ON THE CURRENT PRECIPITATION TRENDS...AND BOTH BRING THE PRECIPITATION NORTH AND EASTWARD INTO OUR CWA. HAVE DONE SOME DRAMATIC MODIFICATIONS TO POPS AND WEATHER FOR TODAY. THE TWO HIGH RESOLUTION MODELS ACTUALLY LIFT IT INTO THE CWA BUT DECREASE THE PRECIPITATION GRADUALLY. WILL KEEP THIS TREND GOING. HAVE ALSO ADDED AREAS OF DRIZZLE AND DENSE FOG NEAR LAKE SUPERIOR...WHICH WILL LIKELY CONTINUE THROUGHOUT THE DAY IN SOME FORM. FOR LATER TODAY AND TONIGHT...MOST OF THE MODEL SOLUTIONS DO BRING A DRAMATIC INCREASE IN PRECIPITATION...AS A FRONTAL BOUNDARY STRETCHES FROM SW TO NE ACROSS THE AREA. WILL INCREASE POPS LATER TODAY AND TONIGHT. COULD STILL SEE SOME STRONG TO SEVERE STORMS IF WE ARE ABLE TO SEE ENOUGH DAYTIME HEATING FOR SURFACE BASED CONVECTION. THE FAIRLY HIGH CHANCE OF SHOWERS AND THUNDERSTORMS WILL ALSO CONTINUE ON SUNDAY...AS THE FRONT REMAINS IN THE AREA. WILL DEFINITELY NEED TO CONTINUE TO MONITOR THE THREAT OF FLOODING ACROSS THE AREA. PRECIPITABLE WATER VALUES ARE ON THE ORDER OF 1.8 INCHES TODAY INTO SUNDAY...SO THERE IS ABUNDANT AVAILABLE MOISTURE. TEMPS WILL BE TROUBLESOME TODAY BASED ON CLOUDS AND PCPN TRENDS. OVERALL WE SHOULD SEE 70S FOR MOST AREAS TODAY AND SOME 80S SUNDAY. IT WILL BE DRAMATICALLY COOLER NEAR LAKE SUPERIOR WITH SOME FAIRLY STRONG NORTHEAST WINDS. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY NIGHT... UPPER LOW AND CO-LOCATED SFC LOW WILL MOVE FROM SRN MANITOBA AND WRN ONTARIO TO THE E/NE ACROSS NRN/CENTRAL ONTARIO SUNDAY NIGHT AND MONDAY MORNING. A TRAILING COLD FRONT WILL SWEEP ACROSS THE UPPER MIDWEST AND BRING RAIN SHOWERS AND THUNDERSTORMS TO MUCH OF THE NORTHLAND THROUGH MON MORNING. HIGH PRESSURE IS EXPECTED TO BUILD IN ACROSS NRN MN LATE MON AFTERNOON AND INTO MONDAY NIGHT. THIS WILL ALLOW CONDITIONS TO REMAIN QUIET...AT LEAST UNTIL TUE MORNING WHEN THE NEXT FRONT IS EXPECTED TO LIFT NWD THROUGH THE REGION AND SPREAD ANOTHER ROUND OF SHOWERS AND STORMS THROUGH WED EVENING. AN AREA OF LOW PRESSURE WILL DEVELOP OVER S-CENTRAL CANADA...ON THE NWRN FLANK OF THE SFC TROUGH/WARM FRONT...AND MOVE EWD INTO NRN ONTARIO ON THURSDAY. THIS LOW PRESSURE WILL DRAW IN SLIGHTLY COOLER AIR FROM NRN CANADA AND MODIFY LOW LEVEL THERMAL PROFILES ACROSS NRN MN ENOUGH TO TRIGGER SHOWERS AND STORMS ACROSS THE REGION THROUGH FRIDAY. TEMPERATURES MONDAY THROUGH THURSDAY WILL BE WARM WITH HIGHS IN THE 70S AND 80S...AND 60S AROUND THE PERIPHERY OF LAKE SUPERIOR. OVERNIGHT LOWS WILL BE MILD WITH TEMPS DROPPING INTO THE UPPER 50S AND 60S. AVIATION.../06Z TAF ISSUANCE/ NEXT FEW HOURS A CLUSTER OF THUNDERSTORMS MAY AFFECT KHYR WITH IFR CIGS AND MVFR VSBYS. OTHERWISE...LAKE EFFECTS ARE PRODUCING STRATUS OVER MOST OF THE REGION WITH MVFR CIGS...WITH LIFR AT KDLH. STRATUS HAS LOTS OF HOLES STILL AT KBRD AND KHYR...AND KINL HAS NOT BEEN AFFECTED AT ALL. THIS STRATUS LAYER SHOULD CONTINUE OVERNIGHT WITH SOME MVFR FOG ALSO EXPECTED. KDLH TO REMAIN LIFR IN FOG AND STRATUS WITH THE LIGHT EAST WINDS CONTINUING. WINDS TO TURN MORE SOUTHERLY SATURDAY IN THE 15Z-18Z TIME RANGE AND EXPECT CIGS TO IMPROVE DURING THE DAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED DURING THE AFTERNOON FOR AT LEAST A SHORT TIME...BUT TIMING AND LOCATION STILL UNCERTAIN SO HAVE LEFT AS VCTS FOR NOW. && .POINT TEMPS/POPS... DLH 62 57 77 60 / 60 70 60 60 INL 75 62 77 58 / 50 50 60 60 BRD 76 67 82 61 / 60 70 50 50 HYR 78 69 86 63 / 60 70 60 60 ASX 73 61 83 61 / 70 70 60 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR MNZ020-021- 037. WI...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR WIZ001>004. LS...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121- 140>148. SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ143>146. && $$ SHORT TERM...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
701 AM CDT SAT JUN 22 2013 .AVIATION...12Z TAF ISSUANCE... LOW PRESSURE SYSTEM OVER SWRN MN AND ERN NEB WILL CONTINUE TO SPREAD SHOWERS AND STORMS THROUGH THE REGION TODAY AND TONIGHT. THE EXACT TIMING AND PLACEMENT OF PRECIP WILL BE DIFFICULT TO NAIL DOWN...SO KEPT WITH VCSH LATE MORNING AND AFTERNOON...AND ANOTHER ROUND OF SHOWERS LATE TONIGHT. HAVE FOG THIS MORNING AT DLH LIFTING BY 15/17Z...BUT KEEPING LOW CLOUDS IN THROUGH MOST OF THE DAY AND FOG RETURNING TONIGHT. E/NE WINDS WILL BECOME GUSTY THIS AFTERNOON. && .PREV DISCUSSION... /ISSUED 409 AM CDT SAT JUN 22 2013/ SHORT TERM...TODAY THROUGH SUNDAY. THE FOCUS FOR TODAY THROUGH SUNDAY WILL CONTINUE TO BE PCPN POTENTIAL...AS WELL AS THE CONTINUED POTENTIAL FOR FOG AND DRIZZLE. PORTIONS OF THE CWA ARE ALSO IN THE SLIGHT RISK FOR SEVERE WEATHER TODAY AND TONIGHT. AT 330 AM...IT WAS ESSENTIALLY DRY ACROSS THE NORTHLAND. THERE WERE A FEW LIGHT SHOWERS NORTH OF THE IRON RANGE...AND ALSO IN NW WI. WIDESPREAD SHOWERS AND THUNDERSTORMS CONTINUED FROM EASTERN SOUTH DAKOTA...THROUGH CENTRAL AND SOUTHERN MN AND SOUTHERN WI WITH WIDESPREAD MCS ACTIVITY IN THOSE AREAS. DENSE FOG CONTINUED NEAR LAKE SUPERIOR AND HAVE ISSUED A DENSE FOG ADVISORY FOR LAND AND WATER AREAS. THE BIG QUESTION IS THE EVOLUTION OF THE WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE SOUTH OF THE AREA. AS EXPECTED WITH THIS TYPE OF PATTERN...THE MODELS REALLY DO NOT HAVE A HANDLE ON THE CURRENT PRECIPITATION. THERE ARE A FEW EXCEPTIONS...INCLUDING THE 4 KM WRF AND THE 06Z HRRR RAPID REFRESH. BOTH HAVE A RELATIVELY DECENT HANDLE ON THE CURRENT PRECIPITATION TRENDS...AND BOTH BRING THE PRECIPITATION NORTH AND EASTWARD INTO OUR CWA. HAVE DONE SOME DRAMATIC MODIFICATIONS TO POPS AND WEATHER FOR TODAY. THE TWO HIGH RESOLUTION MODELS ACTUALLY LIFT IT INTO THE CWA BUT DECREASE THE PRECIPITATION GRADUALLY. WILL KEEP THIS TREND GOING. HAVE ALSO ADDED AREAS OF DRIZZLE AND DENSE FOG NEAR LAKE SUPERIOR...WHICH WILL LIKELY CONTINUE THROUGHOUT THE DAY IN SOME FORM. FOR LATER TODAY AND TONIGHT...MOST OF THE MODEL SOLUTIONS DO BRING A DRAMATIC INCREASE IN PRECIPITATION...AS A FRONTAL BOUNDARY STRETCHES FROM SW TO NE ACROSS THE AREA. WILL INCREASE POPS LATER TODAY AND TONIGHT. COULD STILL SEE SOME STRONG TO SEVERE STORMS IF WE ARE ABLE TO SEE ENOUGH DAYTIME HEATING FOR SURFACE BASED CONVECTION. THE FAIRLY HIGH CHANCE OF SHOWERS AND THUNDERSTORMS WILL ALSO CONTINUE ON SUNDAY...AS THE FRONT REMAINS IN THE AREA. WILL DEFINITELY NEED TO CONTINUE TO MONITOR THE THREAT OF FLOODING ACROSS THE AREA. PRECIPITABLE WATER VALUES ARE ON THE ORDER OF 1.8 INCHES TODAY INTO SUNDAY...SO THERE IS ABUNDANT AVAILABLE MOISTURE. TEMPS WILL BE TROUBLESOME TODAY BASED ON CLOUDS AND PCPN TRENDS. OVERALL WE SHOULD SEE 70S FOR MOST AREAS TODAY AND SOME 80S SUNDAY. IT WILL BE DRAMATICALLY COOLER NEAR LAKE SUPERIOR WITH SOME FAIRLY STRONG NORTHEAST WINDS. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY NIGHT... UPPER LOW AND CO-LOCATED SFC LOW WILL MOVE FROM SRN MANITOBA AND WRN ONTARIO TO THE E/NE ACROSS NRN/CENTRAL ONTARIO SUNDAY NIGHT AND MONDAY MORNING. A TRAILING COLD FRONT WILL SWEEP ACROSS THE UPPER MIDWEST AND BRING RAIN SHOWERS AND THUNDERSTORMS TO MUCH OF THE NORTHLAND THROUGH MON MORNING. HIGH PRESSURE IS EXPECTED TO BUILD IN ACROSS NRN MN LATE MON AFTERNOON AND INTO MONDAY NIGHT. THIS WILL ALLOW CONDITIONS TO REMAIN QUIET...AT LEAST UNTIL TUE MORNING WHEN THE NEXT FRONT IS EXPECTED TO LIFT NWD THROUGH THE REGION AND SPREAD ANOTHER ROUND OF SHOWERS AND STORMS THROUGH WED EVENING. AN AREA OF LOW PRESSURE WILL DEVELOP OVER S-CENTRAL CANADA...ON THE NWRN FLANK OF THE SFC TROUGH/WARM FRONT...AND MOVE EWD INTO NRN ONTARIO ON THURSDAY. THIS LOW PRESSURE WILL DRAW IN SLIGHTLY COOLER AIR FROM NRN CANADA AND MODIFY LOW LEVEL THERMAL PROFILES ACROSS NRN MN ENOUGH TO TRIGGER SHOWERS AND STORMS ACROSS THE REGION THROUGH FRIDAY. TEMPERATURES MONDAY THROUGH THURSDAY WILL BE WARM WITH HIGHS IN THE 70S AND 80S...AND 60S AROUND THE PERIPHERY OF LAKE SUPERIOR. OVERNIGHT LOWS WILL BE MILD WITH TEMPS DROPPING INTO THE UPPER 50S AND 60S. AVIATION.../06Z TAF ISSUANCE/ NEXT FEW HOURS A CLUSTER OF THUNDERSTORMS MAY AFFECT KHYR WITH IFR CIGS AND MVFR VSBYS. OTHERWISE...LAKE EFFECTS ARE PRODUCING STRATUS OVER MOST OF THE REGION WITH MVFR CIGS...WITH LIFR AT KDLH. STRATUS HAS LOTS OF HOLES STILL AT KBRD AND KHYR...AND KINL HAS NOT BEEN AFFECTED AT ALL. THIS STRATUS LAYER SHOULD CONTINUE OVERNIGHT WITH SOME MVFR FOG ALSO EXPECTED. KDLH TO REMAIN LIFR IN FOG AND STRATUS WITH THE LIGHT EAST WINDS CONTINUING. WINDS TO TURN MORE SOUTHERLY SATURDAY IN THE 15Z-18Z TIME RANGE AND EXPECT CIGS TO IMPROVE DURING THE DAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED DURING THE AFTERNOON FOR AT LEAST A SHORT TIME...BUT TIMING AND LOCATION STILL UNCERTAIN SO HAVE LEFT AS VCTS FOR NOW. && .POINT TEMPS/POPS... DLH 66 57 77 60 / 60 70 60 60 INL 75 62 77 58 / 50 50 60 60 BRD 76 67 82 61 / 70 70 50 50 HYR 78 69 86 63 / 60 70 60 60 ASX 73 61 83 61 / 60 70 60 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR MNZ020-021- 037. WI...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR WIZ001>004. LS...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121- 140>148. SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ143>146. && $$ SHORT TERM...DAP LONG TERM....TENTINGER AVIATION...TENTINGER
AREA FORECAST DISCUSSION
NWS DULUTH MN
409 AM CDT SAT JUN 22 2013 .SHORT TERM...TODAY THROUGH SUNDAY. THE FOCUS FOR TODAY THROUGH SUNDAY WILL CONTINUE TO BE PCPN POTENTIAL...AS WELL AS THE CONTINUED POTENTIAL FOR FOG AND DRIZZLE. PORTIONS OF THE CWA ARE ALSO IN THE SLIGHT RISK FOR SEVERE WEATHER TODAY AND TONIGHT. AT 330 AM...IT WAS ESSENTIALLY DRY ACROSS THE NORTHLAND. THERE WERE A FEW LIGHT SHOWERS NORTH OF THE IRON RANGE...AND ALSO IN NW WI. WIDESPREAD SHOWERS AND THUNDERSTORMS CONTINUED FROM EASTERN SOUTH DAKOTA...THROUGH CENTRAL AND SOUTHERN MN AND SOUTHERN WI WITH WIDESPREAD MCS ACTIVITY IN THOSE AREAS. DENSE FOG CONTINUED NEAR LAKE SUPERIOR AND HAVE ISSUED A DENSE FOG ADVISORY FOR LAND AND WATER AREAS. THE BIG QUESTION IS THE EVOLUTION OF THE WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE SOUTH OF THE AREA. AS EXPECTED WITH THIS TYPE OF PATTERN...THE MODELS REALLY DO NOT HAVE A HANDLE ON THE CURRENT PRECIPITATION. THERE ARE A FEW EXCEPTIONS...INCLUDING THE 4 KM WRF AND THE 06Z HRRR RAPID REFRESH. BOTH HAVE A RELATIVELY DECENT HANDLE ON THE CURRENT PRECIPITATION TRENDS...AND BOTH BRING THE PRECIPITATION NORTH AND EASTWARD INTO OUR CWA. HAVE DONE SOME DRAMATIC MODIFICATIONS TO POPS AND WEATHER FOR TODAY. THE TWO HIGH RESOLUTION MODELS ACTUALLY LIFT IT INTO THE CWA BUT DECREASE THE PRECIPITATION GRADUALLY. WILL KEEP THIS TREND GOING. HAVE ALSO ADDED AREAS OF DRIZZLE AND DENSE FOG NEAR LAKE SUPERIOR...WHICH WILL LIKELY CONTINUE THROUGHOUT THE DAY IN SOME FORM. FOR LATER TODAY AND TONIGHT...MOST OF THE MODEL SOLUTIONS DO BRING A DRAMATIC INCREASE IN PRECIPITATION...AS A FRONTAL BOUNDARY STRETCHES FROM SW TO NE ACROSS THE AREA. WILL INCREASE POPS LATER TODAY AND TONIGHT. COULD STILL SEE SOME STRONG TO SEVERE STORMS IF WE ARE ABLE TO SEE ENOUGH DAYTIME HEATING FOR SURFACE BASED CONVECTION. THE FAIRLY HIGH CHANCE OF SHOWERS AND THUNDERSTORMS WILL ALSO CONTINUE ON SUNDAY...AS THE FRONT REMAINS IN THE AREA. WILL DEFINITELY NEED TO CONTINUE TO MONITOR THE THREAT OF FLOODING ACROSS THE AREA. PRECIPITABLE WATER VALUES ARE ON THE ORDER OF 1.8 INCHES TODAY INTO SUNDAY...SO THERE IS ABUNDANT AVAILABLE MOISTURE. TEMPS WILL BE TROUBLESOME TODAY BASED ON CLOUDS AND PCPN TRENDS. OVERALL WE SHOULD SEE 70S FOR MOST AREAS TODAY AND SOME 80S SUNDAY. IT WILL BE DRAMATICALLY COOLER NEAR LAKE SUPERIOR WITH SOME FAIRLY STRONG NORTHEAST WINDS. .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY NIGHT... UPPER LOW AND CO-LOCATED SFC LOW WILL MOVE FROM SRN MANITOBA AND WRN ONTARIO TO THE E/NE ACROSS NRN/CENTRAL ONTARIO SUNDAY NIGHT AND MONDAY MORNING. A TRAILING COLD FRONT WILL SWEEP ACROSS THE UPPER MIDWEST AND BRING RAIN SHOWERS AND THUNDERSTORMS TO MUCH OF THE NORTHLAND THROUGH MON MORNING. HIGH PRESSURE IS EXPECTED TO BUILD IN ACROSS NRN MN LATE MON AFTERNOON AND INTO MONDAY NIGHT. THIS WILL ALLOW CONDITIONS TO REMAIN QUIET...AT LEAST UNTIL TUE MORNING WHEN THE NEXT FRONT IS EXPECTED TO LIFT NWD THROUGH THE REGION AND SPREAD ANOTHER ROUND OF SHOWERS AND STORMS THROUGH WED EVENING. AN AREA OF LOW PRESSURE WILL DEVELOP OVER S-CENTRAL CANADA...ON THE NWRN FLANK OF THE SFC TROUGH/WARM FRONT...AND MOVE EWD INTO NRN ONTARIO ON THURSDAY. THIS LOW PRESSURE WILL DRAW IN SLIGHTLY COOLER AIR FROM NRN CANADA AND MODIFY LOW LEVEL THERMAL PROFILES ACROSS NRN MN ENOUGH TO TRIGGER SHOWERS AND STORMS ACROSS THE REGION THROUGH FRIDAY. TEMPERATURES MONDAY THROUGH THURSDAY WILL BE WARM WITH HIGHS IN THE 70S AND 80S...AND 60S AROUND THE PERIPHERY OF LAKE SUPERIOR. OVERNIGHT LOWS WILL BE MILD WITH TEMPS DROPPING INTO THE UPPER 50S AND 60S. && .AVIATION.../06Z TAF ISSUANCE/ NEXT FEW HOURS A CLUSTER OF THUNDERSTORMS MAY AFFECT KHYR WITH IFR CIGS AND MVFR VSBYS. OTHERWISE...LAKE EFFECTS ARE PRODUCING STRATUS OVER MOST OF THE REGION WITH MVFR CIGS...WITH LIFR AT KDLH. STRATUS HAS LOTS OF HOLES STILL AT KBRD AND KHYR...AND KINL HAS NOT BEEN AFFECTED AT ALL. THIS STRATUS LAYER SHOULD CONTINUE OVERNIGHT WITH SOME MVFR FOG ALSO EXPECTED. KDLH TO REMAIN LIFR IN FOG AND STRATUS WITH THE LIGHT EAST WINDS CONTINUING. WINDS TO TURN MORE SOUTHERLY SATURDAY IN THE 15Z-18Z TIME RANGE AND EXPECT CIGS TO IMPROVE DURING THE DAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED DURING THE AFTERNOON FOR AT LEAST A SHORT TIME...BUT TIMING AND LOCATION STILL UNCERTAIN SO HAVE LEFT AS VCTS FOR NOW. && .POINT TEMPS/POPS... DLH 70 57 77 60 / 60 70 60 60 INL 75 62 77 58 / 50 50 60 60 BRD 81 67 82 61 / 70 70 50 50 HYR 83 69 86 63 / 60 70 60 60 ASX 76 61 83 61 / 60 70 60 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR MNZ020-021- 037. WI...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR WIZ001>004. LS...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121- 140>148. SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 10 PM CDT THIS EVENING FOR LSZ143>146. && $$ SHORT TERM...DAP LONG TERM....TENTINGER AVIATION...TENTINGER
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
112 AM CDT SAT JUN 22 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 345 PM CDT FRI JUN 21 2013 ANOTHER ACTIVE SHORT TERM IS EXPECTED...WITH POTENTIAL FOR BOTH ANOTHER SEVERE WEATHER EVENT AND A SIGNIFICANT FLASH FLOOD EVENT OVER SRN MN BEING CLOSELY MONITORED TONIGHT. WARM FRONTAL BOUNDARY AT 3PM STRETCHES FROM ROUGHLY MARSHALL OVER TOWARD RED WING. VERY UNSTABLE AIRMASS COMBINED WITH A WAVE THAT CAME OUT OF THE BLACK HILLS THIS MORNING HAS SEVER CLUSTER OF STORMS OVER SODAK THAT IS RAPIDLY APPROACHING SW MN. THE SYSTEM IS STARTING TO BOW...WITH HURON REPORTING A WIND GUST OF 87 MPH. HAVE BEEN LEANING ON THE HRRR HEAVILY ALL DAY TO TRACK THIS SYSTEM ACROSS THE AREA. EXPECT THESE STORMS TO BASICALLY FOLLOW THE WARM FRONT AND 850-300 THICKNESS LINES TO THE ESE ACROSS SRN MN. TORNADO/LARGE HAIL TREAT WILL BE HIGHEST ALONG THE SODAK BORDER...WITH THE THREAT TRANSITIONING OVER TO MORE OF A WIND THREAT AS YOU HEAD EAST. WOULD NOT BE SURPRISED IF BY 5 OR 6 PM WE ARE COORDINATING WITH THE SPC FOR A SVR THUNDERSTORM WATCH TO THE EAST OF THE CURRENT TOR WATCH. FOR TONIGHT THOUGH...THE REAL BIG CONCERN IS THE POTENTIAL FOR A SIGNIFICANT RAINFALL/FLASH FLOODING EVENT ACROSS SRN MN. THE RAP HAS THE NOSE OF A PERSISTENT 40-50 KT LLJ COMING UP OUT OF THE PLAINS AND REMAINING MORE OR LESS STATIONARY INTO SW MN. AS THE HRRR SHOWS...WITH 3000-5000 J/KG OF MUCAPE REMAINING IN PLACE WITH THE LLJ...THE PROBABILITY FOR ADDITIONAL TSRA DEVELOPMENT BACK INTO THE SD/NEB/IA AREA THROUGH THE NIGHT WILL BE HIGH. THIS WILL LEAD TO A THREAT FOR TRAINING OF STORMS TONIGHT...WITH THE POTENTIAL FOR SOME RATHER SIGNIFICANT RAINFALL TOTALS IN EXCESS OF 6 INCHES POSSIBLE FOR TONIGHT. GIVEN THE POTENTIAL...HAVE ISSUED A FLASH FLOOD WATCH FOR AREAS ALONG AND SOUTH OF AN APPLETON TO CHIPPEWA FALLS LINE...WITH THE POTENTIAL FOR SEEING MULTIPLE ROUNDS OF STORMS IS HIGHEST. GIVEN THE SOUTHERN POSITION OF THE WARM FRONT...LESSER AMOUNTS OF RAINFALL ARE CURRENTLY ANTICIPATED OVER CENTRAL MINNESOTA INTO NW WISCONSIN. LIKE TODAY...EXPECT ACTIVITY TO WIND DOWN THROUGH THE MORNING ACROSS THE MPX AREA...WITH MUCH OF THE LATE MORNING INTO THE EARLY AFTERNOON REMAINING DRY. THE BIG DIFFERENCE THOUGH ON SATURDAY TO THE PAST TWO DAYS...IS THE SYNOPTIC COLD/STATIONARY FRONT AND LOW PRESSURE SYSTEM WILL BE FARTHER EAST. BY THE AFTERNOON...MODELS SHOW A LEE SIDE LOW DEVELOPING OVER ERN COLORADO...WITH A STATIONARY FRONT/PRESSURE TROUGH EXTENDING TO THE NORTHEAST TOWARD WRN MN. WITH THE SYNOPTIC FEATURES FARTHER EAST TOMORROW...THIS SHOULD INCREASE THE CHANCES FOR THUNDERSTORMS DEVELOPING IN THE AFTERNOON ACROSS THE MPX AREA...WHICH WILL LEAD TO A HIGHER PROBABILITY FOR SEEING TORNADOES OR HAIL DURING THE AFTERNOON...BEFORE ANOTHER POTENTIAL ROUND OF STORMS GOING INTO SATURDAY NIGHT. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 345 PM CDT FRI JUN 21 2013 NO SIGNIFICANT CHANGES FROM THE PREVIOUS FORECAST...WITH SEVERE AND HYDRO CONCERNS CONTINUING THROUGH EARLY NEXT WEEK. THE UPPER LEVEL LOW WILL LINGER JUST TO THE WEST...WITH THE SURFACE TROUGH INCHING EVER CLOSER TO WESTERN MINNESOTA BY THE WEEKEND...AND THE FRONTAL BOUNDARY STALLED OUT EAST/WEST ACROSS THE FORECAST AREA ONLY TO OSCILLATE NORTH/SOUTH WITH EACH CONVECTIVE OUTFLOW BOUNDARY. THE TROPICAL AIRMASS WILL REMAIN IN PLACE THROUGH EARLY NEXT WEEK...WITH PWAT VALUES IN THE 1.75 TO 2.00 INCH RANGE. SREF 21.09 MLCAPE PLUMES CONTINUE TO SHOW 2500 TO 4000J/KG DURING THE AFTERNOON...AND THIS SEEMS REASONABLE CONSIDERING WHAT IS CURRENTLY GOING ON ACROSS SOUTHWEST MINNESOTA. DEEP LAYER SHEAR WILL ONLY BE IN THE 25KT RANGE...BUT THE SEVERE WEATHER REMAINS A CONCERN SINCE THE STORMS MAY BE ABLE TO MODIFY THEIR OWN ENVIRONMENT AS IS THE CASE THIS AFTERNOON ACROSS EASTERN SOUTH DAKOTA. AS THE SURFACE TROUGH SLOWLY PROGRESSES EASTWARD...THE POTENTIAL FOR AFTERNOON CONVECTION WILL INCREASE AS WELL. THEREFORE THE MISSISSIPPI RIVER VALLEY MAY TRANSITION FROM A PURELY NOCTURNAL EVENT AS WAS THE CASE LAST NIGHT...TO MORE OF A AFTERNOON AND EVENING FOCUS. FORECAST MODELS CONTINUE TO SHOW A SHORTWAVE MOVING ACROSS NORTHERN MINNESOTA SATURDAY NIGHT...SO IF STORMS DO NOT DEVELOP TOMORROW AFTERNOON THEY WILL CERTAINLY FORM AHEAD OF THAT WAVE. ANOTHER WAVE FOLLOWS FOR SUNDAY EVENING...SO COULD SEE SOME QUICK REDEVELOPMENT DURING THE DAY ON SUNDAY. LOOKING AHEAD...BOTH THE GFS AND ECMWF TRANSITION TO A MORE ZONAL PATTERN WITH THE H250 JET STRADDLING THE INTERNATIONAL BORDER...AND CONTINUED CHANCES FOR POPS THROUGH THE MIDDLE OF THE WEEK. THE UPPER LEVEL RIDGE TRIES TO BUILD ACROSS THE ROCKIES BY LATE NEXT WEEK...BUT CONFIDENCE IS LOW IN THE DEVELOPMENT OF THIS FEATURE GIVEN THE CONTINUED DELAYED ONSET WITH EACH MODEL RUN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1249 AM CDT SAT JUN 22 2013 ANOTHER POTENTIALLY ACTIVE 24 HOUR PERIOD EXPECTED...MAINLY IN THE FIRST 6 HOURS AND THEN IN THE LAST 6 HOURS. CDFNT WOBBLING OVER THE IA/MN BORDER WILL SLOWLY LIFT N DURG THIS TAF PERIOD. RAIN/TSTMS ALONG IT OVER MAINLY FAR SRN MN INTO SW WI WILL SLOWLY SHIFT N THIS MRNG...RESULTING IN DEGRADED CONDS FOR KRWF-KMSP- KEAU-KRNH. AM THINKING KAXN-KSTC SHOULD STAY OUT OF THE ACTION THIS MRNG. ONCE THE PRECIP ENDS...WHICH SHOULD BE BY 12Z THIS MRNG...WILL HAVE A REPRIEVE FROM THE PRECIP AND THERE MAY EVEN BE A FEW BREAKS IN THE OVC. ONCE THE ATMOS RELOADS ITS INSTABILITY...LIFT FROM THE NWW-MOVNIG CDFNT AND A CONTINUED MOIST ATMOS WILL ALLOW FOR RE-DEVELOPMENT OF CONVECTION LATE THIS AFTN THRU THIS EVE. STILL SOME TIMING ISSUES BUT HAVE GENERALLY HIGHLIGHTED THE BEST TIMING FOR EACH TAF SITE BASED ON GRIDDED FORECASTS AND RAP/HRRR MODELS. THESE TEMPO GROUPS AT THE END OF THE TAFS MAY WELL NEED TO BE ADJUSTED BUT FELT CONFIDENT ENOUGH ATTM TO AT LEAST HIGHLIGHT THE LIKELY CHC OF TSTMS LATER TDA. KMSP...GENERALLY LIGHT SHOWERS WITH A SOME IC/CC/CG LIGHTNING OVER THE FIRST FEW HRS OF THE 06Z TAF THEN PRECIP ACTIVITY WILL WANE GOING INTO DAYBREAK. PRECIPITATION WILL RESUME LATER THIS EVENING AND POTENTIALLY INTO THE OVERNIGHT HOURS. STILL SOME TIMING ISSUES AS TO WHEN BUT HAVE HIGHLIGHTED THE BEST TIMING GIVEN CURRENT SHORT-TERM MODEL RUNS AND GRIDDED FCSTS. STILL ALSO THE POTENTIAL FOR WINDS IN EXCESS OF 35 KT LET ALONE THE SLGT RISK FOR SEVERE TSTMS THIS EVENING AND TNGT. /OUTLOOK FOR KMSP/ SUN...TSRA LIKELY. VFR OUTSIDE OF TSRA. WINDS SSW 10-15 KTS. MON...CHC TSRA. VFR OUTSIDE OF TSRA. WINDS S 5-10 KTS. TUE...CHC TSRA. VFR OUTSIDE OF TSRA. WINDS SSE 10-15 KTS. && .HYDROLOGY... ISSUED AT 345 PM CDT FRI JUN 21 2013 AS ALLUDED TO EARLIER PWATS WILL BE IN THE 90TH PERCENTILE THOUGH EARLY NEXT WEEK. THE AREA IS INCREASINGLY VULNERABLE TO BOTH FLASH FLOODING...AND RIVER FLOODING GIVEN THE WIDESPREAD RAINFALL AMOUNTS OF 2-4 INCHES FALLING LAST NIGHT. THE EAST/WEST FRONTAL BOUNDARY SUPPORTS TRAINING THUNDERSTORMS...AND THE H925 MOISTURE TRANSPORT SURGES NORTHWARD OVERNIGHT AS THE LOW LEVEL JET DECOUPLES FROM THE BOUNDARY LAYER. CONTINGENCY FORECAST BASED OFF DIFFERENT QPF SCENARIOS SHOW THE POTENTIAL FOR SIGIFICANT FLOODING BY EARLY NEXT WEEK ALONG THE QUICKER RESPONSE RIVERS...AND EVENTUALLY THE LARGER MAIN STEMS OF THE MINNESOTA AND MISSISSIPPI RIVER. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR MNZ041>045-047>070- 073>078-082>085-091>093. WI...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR WIZ014>016-023>028. && $$ SHORT TERM...MPG LONG TERM...JRB AVIATION...JPC HYDROLOGY...JRB
AREA FORECAST DISCUSSION
NWS JACKSON MS
1217 PM CDT SAT JUN 22 2013 .UPDATE... WILL UPDATE TO INCREASE POPS A BIT FOR THE AFTERNOON...BUT STILL EXPECT COVERAGE TO REMAIN FAIRLY ISOLATED. A FEW SHOWERS/THUNDERSHOWERS HAVE DEVELOPED ALONG/WEST OF THE I-55 CORRIDOR IN REGION OF SUBTLE LOW LEVEL MOISTURE CONVERGENCE INDUCED BY WEAK UPPER LEVEL DIVERGENCE ALONG THE MS RIVER. MORNING RUNS OF THE HRRR HAD SEEMED A LITTLE OVERDONE BUT LOOK PRETTY GOOD RIGHT NOW. /EC/ && .PREV DISCUSSION... /ISSUED 1059 AM CDT SAT JUN 22 2013/ UPDATE... THE FORECAST IS ON TRACK AND ONLY MINOR ADJUSTMENTS WERE MADE TO TEMPERATURES AND AFTERNOON WEATHER. DID NOT ADJUST LOW POPS...BUT VARIOUS HIGH-RES GUIDANCE SUGGEST ISOLATED SHOWERS/THUNDERSHOWERS ARE A GOOD POSSIBILITY OVER WESTERN/SOUTHERN PORTIONS OF THE FORECAST AREA AND HAVE ADDED EXPLICIT MENTION. /EC/ && .AVIATION... VFR CONDS TO PERSIST THRU THE REMAINDER OF THE DAY. ISOLD SHRA MAY DEVELOP ACROSS SRN MS THRU THE AFTN BEFORE QUIET CONDS RETURN THIS EVE. MVFR/IFR CIG AND VSBY MAY DEVELOP AT HBG/PIB TOMORROW MORNING 10-14Z. SFC WINDS WL REMAIN LGT AND ELY/SELY OVR THE NEXT 24 HRS. /BK/ PREV DISCUSSION... /ISSUED 334 AM CDT SAT JUN 22 2013/ SHORT TERM...TODAY THROUGH SUNDAY NIGHT...WEAK E/SELY ANTICYCLONIC FLOW AT LOWER LEVELS ALONG WITH BACKING FLOW ALOFT WILL KEEP CONVECTION GENERALLY QUIET TODAY. ONE OR TWO VERY ISOLATED CELLS MAY POP UP DURING THE LATE AFTERNOON AND EARLY EVENING BUT CONDITIONS WILL GENERALLY REMAIN DRY ACROSS THE REGION. RAIN CHANCES WILL INCREASE SOMEWHAT FOR SUNDAY AFTERNOON AND EVENING...MAINLY IN THE SOUTH. WEAK LOW LEVEL CONVERGENCE AND THE DEVELOPMENT OF FLAT UPPER TROUGHING SUNDAY WILL PRODUCE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS GENERALLY I-20 SWD IN THE AFTERNOON AND EVENING SUNDAY. OTHER THAN A FEW SMALL TWEAKS MAV MOS GUIDANCE WAS FOLLOWED... TEMPERATURES PRIMARILY CONTINUING CLOSE TO SEASONAL NORMS. LONG TERM...MONDAY INTO NEXT WEEKEND...THIS PORTION OF THE FORECAST LOOKING RATHER TYPICAL...ALTHOUGH PERHAPS A BIT ON THE DRYISH SIDE...THROUGH AT LEAST NEXT THURSDAY. THROUGH THE WEEK THE CENTER OF SUPPRESSIVE SUBTROPICAL RIDGING ALOFT WILL SHIFT FARTHER AND FARTHER WEST OF OUR REGION ALTHOUGH TRUE TROUGHING SHOULD NOT DIG DOWN THIS WAY UNTIL AROUND FRIDAY. FLOW AT THE SURFACE WILL GENERALLY BE WEAK AND SOUTHERLY...BUT EXHIBITING SOME ANTICYCLONIC TENDENCIES DUE TO AT LEAST WEAK SUBSIDENCE IN THE VICINITY FOR MUCH OF THE WEEK. BECAUSE OF THIS LATTER FACT...AND THE IDEA THAT SURFACE COMBINATIONS OF HEAT AND HUMIDITY WILL NOT BE OVERLY HIGH...EXPECT AFTERNOON CONVECTION TO BE GENERALLY ISOLATED AT BEST THROUGH THE WORK WEEK. EXCEPTIONS TO THIS COULD COME IN SOUTHERN ZONES BY THURSDAY AND FRIDAY WHEN ACTIVE SEABREEZE-RELATED BOUNDARIES HAVE A BETTER CHANCE OF GETTING SUFFICIENTLY NORTH FROM THE COAST. BY FRIDAY AND DEFINITELY INTO NEXT WEEKEND NUMERICAL MODEL CONSENSUS IS FAIRLY GOOD THAT A SOMEWHAT SIGNIFICANT SUMMER UPPER LEVEL TROUGH WILL DIG DOWN INTO THE EASTERN HALF OF THE CONUS. THIS SHOULD DRIVE A COLD FRONT SOUTH INTO OUR REGION BY SATURDAY...WITH THIS BOUNDARY REACTING WITH MOISTURE AND INSTABILITY TO INCREASE THUNDERSTORM PRODUCTION A GOOD DEAL. AT THIS POINT IT IS HARD TO SAY WHETHER THIS TROUGH WILL BE A BIG ENOUGH DEAL TO TRULY PUSH THE FRONT SOUTH OF OUR REGION...WHICH IS SOMETHING HARD TO DO AT THE START OF JULY. AS FOR TEMPERATURES...GFS-BASED MEX GUIDANCE LOOKED GOOD ADVERTISING TEMPS PERHAPS SLIGHTLY ABOVE AVERAGE FOR HIGHS BUT NEAR AVERAGE FOR LOWS. I MADE ONLY A FEW SLIGHT TWEAKS THROUGH THE PERIOD BASED ON TRENDS THUS FAR THIS SUMMER. OF COURSE SOME DEGREE OF COOL DOWN ANTICIPATED BY NEXT WEEKEND WITH THE FRONT COMING IN...BUT UNTIL THEN HEAT SHOULD NOT BE OPPRESSIVE ENOUGH TO WARRANT HEAT ADVISORIES. FINALLY...MONDAY THROUGH AT LEAST THURSDAY THERE ARE NO SIGNALS FOR MUCH ROBUST TSTORM ACTIVITY. STRONGER STORMS POSSIBLE WITH THE FRONT AT THE END OF THE WEEK BUT IT IS STILL WAY TOO EARLY TO ADVERTISE THAT IN THE HWO. /BB/ && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1149 PM CDT FRI JUN 21 2013 .UPDATE... ISSUED AT 933 PM CDT FRI JUN 21 2013 SCANT CONVECTION THAT DOTTED OUR S IL COUNTIES EARLY THIS EVENING HAS DISSIPATED...AND AM EXTREMELY HARD-PRESSED TO DISCERN ANY MECHANISM FOR REDEVELOPMENT OVERNIGHT. STRONGEST 850MB WAA WILL BE FOCUSED WELL TO OUR N THROUGHOUT THE NIGHT...AND THE MID LEVEL WAA THAT WAS RESPONSIBLE FOR LAST NIGHTS CONVECTION IS MUCH...MUCH WEAKER OVER OUR AREA THAN IT WAS LAST NIGHT. SO...WILL GO WITH A DRY FORECAST FOR REMAINDER OF THE NIGHT WITH SOME OCCASIONAL MID AND HIGH LEVEL CLOUDINESS. TEMPERATURE TRENDS STILL LOOKING GOOD. ZONES WILL BE OUT IN A SECOND. TRUETT && .SHORT TERM...(THROUGH LATE TONIGHT) ISSUED AT 323 PM CDT FRI JUN 21 2013 THE MAIN SHORT-TERM CONCERN IS THE MCS GENERATED OUTFLOW BOUNDARY CURRENTLY DROPPING S/SEWD THROUGH CENTRAL IL. WHILE THE MCS ITSELF IS MOVING SEWD...THE RUC 0-3 KM AND 0-6 KM SHEAR VECTORS SUGGEST THAT AS LONG AS THIS BOUNDARY MAINTAINS ITS IDENTITY IT SHOULD CONTINUE TO DROP S/SEWD AND AT LEAST IMPACT AREAS EAST OF THE MS RIVER LATE THIS AFTERNOON INTO EARLY THIS EVENING. THE AIR MASS AHEAD OF THIS BOUNDARY IS WEAKLY CAPPED WITH SBCAPE INCREASING FROM 2000 J/KG IN CENTRAL IL TO NEAR 4000 J/KG ALONG THE RIVER. THIS COMBINATION OF INSTABILITY/CAPPING AND CONVERGENCE WITH THE BOUNDARY SUPPORTS A GREATER CHANCE OF MORE ORGANIZED CONVECTION ACROSS SOUTH CENTRAL IL WHERE SCATTERED THUNDERSTORMS ARE POSSIBLE. ELSEWHERE THROUGH SUNSET ANY THREAT OF SHOWERS/THUNDERSTORMS WILL BE ISOLATED PULSE TYPE ACTIVITY ASSOCIATED WITH DIURNAL HEATING. I THINK THERE WILL THEN BE A LULL FROM SAY AROUND 02-03Z TIL 08Z OR SO...THEN ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS...PRIMARILY ACROSS ERN MO INTO SW/SC IL... ASSOCIATED WITH LOW-MID LEVEL WAA VIA THE SWLY LLJ AND STEEP MID LEVEL LAPSE RATES. OVERNIGHT LOWS WILL BE QUITE MILD AND ABOVE SEASONABLE NORMS. GLASS .LONG TERM...(SATURDAY THROUGH NEXT FRIDAY) ISSUED AT 323 PM CDT FRI JUN 21 2013 (SATURDAY THROUGH MONDAY) BROKEN RECORD FOR WEATHER PATTERN AS WE REMAIN IN WARM SECTOR ON SATURDAY WITH SOME WEAK INSTABILITY AND PLENTY OF MOISTURE. SO ANY OLD OUTFLOW BOUNDARY...ETC COULD TRIGGER ISOLATED THUNDERSTORM DEVELOPMENT...SO KEPT SLIGHT CHANCE POPS FOR SATURDAY AFTERNOON. OTHERWISE...HIGHS WILL BE IN THE UPPER 80S TO LOW 90S...POSSIBLY IN THE MID 90S IN THE STL METRO AREA. LOWS SATURDAY NIGHT WILL BE IN THE LOW 70S. UPPER RIDGE BUILDS IN A BIT STRONGER ON SUNDAY...SO THUNDERSTORM CHANCES DIMINISH. BUT HOT AND HUMID CONDITIONS TO PERSIST WITH HIGHS IN THE UPPER 80S TO LOW 90S. ON SUNDAY NIGHT AND MONDAY...UPPER RIDGE BEGINS TO WEAKEN AGAIN AS NEXT WEATHER SYSTEM APPROACHES THE REGION. MCS EXPECTED TO DEVELOP ALONG BOUNDARY OVER IOWA...WITH SOUTHERN FRINGES SLIDING THROUGH NORTHERN MO/WEST CENTRAL IL ON MONDAY. LOWS SUNDAY NIGHT WILL BE IN THE LOW TO MID 70S WITH HIGHS ON MONDAY IN THE UPPER 80S TO LOW 90S. (MONDAY NIGHT THROUGH FRIDAY) EXTENDED MODELS CONTINUE TO SLOW DOWN PASSAGE OF THIS COLD FRONT...SO HOT AND HUMID CONDITIONS TO PERSIST THROUGH THURSDAY WITH HIGHS EACH DAY IN THE UPPER 80S TO MID 90S. BY WEDNESDAY NIGHT...COLD FRONT MOVES CLOSER TO AREA WITH CHANCES OF SHOWERS AND THUNDERSTORMS FOR PORTIONS OF THE AREA WEDNESDAY NIGHT AND THURSDAY. CONFIDENCE ON TIMING OF FRONTAL PASSAGE LOW...SO FOR NOW HAVE SILENT SLIGHT CHANCE POPS IN FOR AREA THURSDAY NIGHT AND PORTIONS OF THE AREA FRIDAY UNTIL FRONT FINALLY MOVES THROUGH. BY FRIDAY HIGHS WILL BE IN THE MID TO UPPER 80S. BYRD && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1140 PM CDT FRI JUN 21 2013 NOT MUCH CHANGE FROM PREVIOUS TAF PACKAGE. MIDLEVEL ANTICYCLONE REMAINS OVERHEAD STEERING ANY ORGANIZED CONVECTION WELL AWAY FROM THE CWFA. LATEST NAM/GFS DOES TRY AND PAINT OUT SOME LIGHT PRECIPITATION OVERNIGHT TONIGHT. HOWEVER...MODELS DID NOT SEEM TO INITIALIZE CURRENT CONVECTION WELL. GIVEN THAT NOTE AND POSITION BENEATH SYNOPTIC RIDGE...HAVE CONTINUED TO LEAVE OUT ANY MENTION OF TS/SHRA. SCT HIGH-LEVEL CLOUDINESS WILL GIVE WAY TO MORE DIURNAL CU WITH VFR BASES. AS FOR WINDS...SOUTHERLY WINDS WILL CONTINUE THROUGH THE VALID TAF PERIOD AND PICK UP JUST A BIT DURING THE DAY TOMORROW AROUND 10 KTS. BUFKIT SOUNDINGS DO NOT SHOW MUCH IN THE WAY OF WINDS TO MIX DOWN TO SFC AT TOP OF BOUNDARY LAYER UNLIKE THIS AFTERNOON...SO DO NOT HAVE ANY GUSTS MENTIONED. SPECIFICS FOR KSTL... NOT MUCH CHANGE FROM PREVIOUS TAF PACKAGE. MIDLEVEL ANTICYCLONE REMAINS OVERHEAD STEERING ANY ORGANIZED CONVECTION WELL AWAY FROM LAMBERT FIELD. LATEST NAM/GFS DOES TRY AND PAINT OUT SOME LIGHT PRECIPITATION OVERNIGHT TONIGHT. HOWEVER...MODELS DID NOT SEEM TO INITIALIZE CURRENT CONVECTION WELL. GIVEN THAT NOTE AND POSITION BENEATH SYNOPTIC RIDGE...HAVE CONTINUED TO LEAVE OUT ANY MENTION OF TS/SHRA. SCT HIGH-LEVEL CLOUDINESS WILL GIVE WAY TO MORE DIURNAL CU WITH VFR BASES DURING THE DAY ON SATURDAY. AS FOR WINDS...SOUTHERLY FLOW WILL CONTINUE THROUGH THE VALID TAF PERIOD AND PICK UP JUST A BIT DURING THE DAY TOMORROW AROUND 10 KTS. BUFKIT SOUNDINGS DO NOT SHOW MUCH IN THE WAY OF WINDS TO MIX DOWN TO SFC AT TOP OF BOUNDARY LAYER UNLIKE THIS AFTERNOON...SO DID NOT DENOTE ANY GUSTS. GOSSELIN && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
250 PM MDT Sat Jun 22 2013 .DISCUSSION... Tonight through Monday...Upper trof presently over the state. Associated cold pool aloft contributing to the instability and the resulting scattered thunderstorms. Thunderstorm activity has decreased the past couple of hours but HRRR analysis and the latest RUC indicate isolated storms remain a possibility during the evening hours. The upper trof moves east and away from the area Sunday. Rising heights will bring drier conditions with the exception of the area along the international boundary. Cyclonic flow from the departing upper low over central Saskatchewan will lead to an area of convergence along the border and the possibility of isolated convection during the afternoon. By Monday, an increasing southwest flow aloft will bring another round of moisture and instability to the area with scattered thunderstorms developing again during the afternoon. Temperatures will climb to near or slightly above seasonal averages to start the week. Emanuel Monday night through Saturday...Expect two different weather patterns during the period. Early in the week models indicate a moist southwest flow aloft. A weather disturbance aloft is expected to move northeast through the area Monday night and Tuesday with the GFS model faster with this feature than the ECMWF and GEM models. Models differ with details of their precipitation forecasts so have not fiddled much with the inherited forecast of a chance of showers/thunderstorms. At this time it does not look like thunderstorms will be severe. Then later in the week models are on the same page in developing a strong upper ridge over the western U.S. with forecast temperatures rising to well above normal. Will continue to forecast high temperatures above most forecast guidance from the models. Thus expect highs in the upper 80s to lower 90s for the lower elevations Friday and Saturday. The intensifying upper ridge should also result in dry weather Wednesday night through Friday. Friday night through Saturday could see an increase in moisture mainly over the northern zones. Will follow the lead of the Glasgow weather office and mention a slight chance of showers/thunderstorms in the north. Blank && .AVIATION... Updated 1720Z. An unstable airmass remains over the area today. The greatest instability will be over southwest and central Montana, along and south of a KHLN to KLWT line. Some of the heavier showers and storms will produce gusty winds...small hail...and could result in brief MVFR conditions. Expect most of the showers and storms to diminish this evening with VFR conditions prevailing through noon Sunday. Winds will remain light today except near showers and storms. Langlieb && .PRELIMINARY POINT TEMPS/POPS... GTF 45 75 51 78 / 20 10 10 30 CTB 44 73 49 73 / 10 20 20 40 HLN 45 77 52 78 / 20 10 10 30 BZN 40 76 46 80 / 20 10 10 30 WEY 31 68 36 70 / 20 10 10 30 DLN 39 74 47 74 / 20 10 10 30 HVR 48 77 53 81 / 20 20 10 30 LWT 43 72 48 78 / 40 10 10 30 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM... LONG TERM... AVIATION... weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1120 AM MDT Sat Jun 22 2013 UPDATED AVIATION SECTION .DISCUSSION... Update forthcoming. Upper trof over the area today will bring scattered showers and thunderstorms. Radar continues to indicate a line of showers along the Belts that is very slowly moving to the north. HRRR analysis indicates this line will become an area of scattered showers later this afternoon. Have made minor adjustments to the pop grids. Temperatures look good. Emanuel && .AVIATION... Updated 1720Z. An unstable airmass remains over the area today. The greatest instability will be over southwest and central Montana, along and south of a KHLN to KLWT line. Some of the heavier showers and storms will produce gusty winds...small hail...and could result in brief MVFR conditions. Expect most of the showers and storms to diminish this evening with VFR conditions prevailing through noon Sunday. Winds will remain light today except near showers and storms. Langlieb && .PREV DISCUSSION...Issued 416 AM MDT Sat Jun 22 2013 Today through Monday...Another cool and unsettled weather day is expected across much of Southwest and Central MT today. With the main upper level low expected to move eastward across southern Idaho today...combined with some fairly cold air aloft...another day of small hail will be possible across portions of Central MT from any of the stronger storms. Severe storms are not expected...as the instability is not expected to be very high. Additionally...light snow will fall this morning across the higher elevations of Southwest MT...mainly above 7000 feet. New snow accumulations should generally be less than inch. Afternoon temperatures will remain a bit below normal...with highs mostly in the 60s at lower elevations. For Sunday...expect the area to mainly be in-between storm system...with the flow aloft becoming a bit more southwesterly. This will result in warmer air returning to the region...and the best chance for any precipitation to occur will be over the front range of the Rockies and near the US/Canadian border. For Monday...the next upper level trof begins to approach the region. However...forecast models differ on how far east the trof will be by late Monday afternoon. Therefore...have continued the slight chance for thunderstorms east of Great Falls...with higher chances west of Great Falls. Afternoon temperatures will be on the warm side...especially east of Great Falls. Brusda Monday night through Saturday...Expect two different weather patterns during the period. Early in the week models indicate a moist southwest flow aloft. A weather disturbance aloft is expected to move northeast through the area Monday night and Tuesday with the GFS model faster with this feature than the ECMWF and GEM models. Models differ with details of their precipitation forecasts so have not fiddled much with the inherited forecast of a chance of showers/thunderstorms. At this time it does not look like thunderstorms will be severe. Then later in the week models are on the same page in developing a strong upper ridge over the western U.S. with forecast temperatures rising to well above normal. Will continue to forecast high temperatures above most forecast guidance from the models. Thus expect highs in the upper 80s to lower 90s for the lower elevations Friday and Saturday. The intensifying upper ridge should also result in dry weather Wednesday night through Friday. Friday night through Saturday could see an increase in moisture mainly over the northern zones. Will follow the lead of the Glasgow weather office and mention a slight chance of showers/thunderstorms in the north. Blank && .PRELIMINARY POINT TEMPS/POPS... GTF 68 44 78 50 / 50 20 10 10 CTB 67 44 75 48 / 20 10 20 10 HLN 67 45 79 51 / 60 20 10 10 BZN 67 40 80 45 / 80 20 10 10 WEY 59 31 67 35 / 70 20 10 10 DLN 65 39 75 46 / 40 20 10 10 HVR 72 47 79 52 / 20 20 20 10 LWT 62 43 74 47 / 80 30 10 10 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
10 AM MDT Sat Jun 22 2013 .DISCUSSION... Update forthcoming. Upper trof over the area today will bring scattered showers and thunderstorms. Radar continues to indicate a line of showers along the Belts that is very slowly moving to the north. HRRR analysis indicates this line will become an area of scattered showers later this afternoon. Have made minor adjustments to the pop grids. Temperatures look good. Emanuel && .AVIATION... Updated 1130Z. An upper trough will move over the area today and bring occasional showers and a few thunderstorms to central and southwest Montana. Towards the Canadian border expect just a few showers and isolated thunderstorms. With the showers and thunderstorms expect local MVFR ceilings and possibly visibilities. Also early this morning there will be local IFR ceilings/visibilities in fog over central Montana. Do not expect any taf sites to be affected by fog except possibly KLWT. Other than local lower conditions with fog and thunderstorms expect VFR conditions today. With the thunderstorms there will also be the threat of small hail and gusty winds to possibly as high as 35 knots. Other than gusty winds with some of the thunderstorms winds should be generally light through the period and confidence in forecast winds is low to moderate. Showers and thunderstorms will diminish this evening. Blank && .PREV DISCUSSION...Issued 416 AM MDT Sat Jun 22 2013 Today through Monday...Another cool and unsettled weather day is expected across much of Southwest and Central MT today. With the main upper level low expected to move eastward across southern Idaho today...combined with some fairly cold air aloft...another day of small hail will be possible across portions of Central MT from any of the stronger storms. Severe storms are not expected...as the instability is not expected to be very high. Additionally...light snow will fall this morning across the higher elevations of Southwest MT...mainly above 7000 feet. New snow accumulations should generally be less than inch. Afternoon temperatures will remain a bit below normal...with highs mostly in the 60s at lower elevations. For Sunday...expect the area to mainly be in-between storm system...with the flow aloft becoming a bit more southwesterly. This will result in warmer air returning to the region...and the best chance for any precipitation to occur will be over the front range of the Rockies and near the US/Canadian border. For Monday...the next upper level trof begins to approach the region. However...forecast models differ on how far east the trof will be by late Monday afternoon. Therefore...have continued the slight chance for thunderstorms east of Great Falls...with higher chances west of Great Falls. Afternoon temperatures will be on the warm side...especially east of Great Falls. Brusda Monday night through Saturday...Expect two different weather patterns during the period. Early in the week models indicate a moist southwest flow aloft. A weather disturbance aloft is expected to move northeast through the area Monday night and Tuesday with the GFS model faster with this feature than the ECMWF and GEM models. Models differ with details of their precipitation forecasts so have not fiddled much with the inherited forecast of a chance of showers/thunderstorms. At this time it does not look like thunderstorms will be severe. Then later in the week models are on the same page in developing a strong upper ridge over the western U.S. with forecast temperatures rising to well above normal. Will continue to forecast high temperatures above most forecast guidance from the models. Thus expect highs in the upper 80s to lower 90s for the lower elevations Friday and Saturday. The intensifying upper ridge should also result in dry weather Wednesday night through Friday. Friday night through Saturday could see an increase in moisture mainly over the northern zones. Will follow the lead of the Glasgow weather office and mention a slight chance of showers/thunderstorms in the north. Blank && .PRELIMINARY POINT TEMPS/POPS... GTF 68 44 78 50 / 50 20 10 10 CTB 67 44 75 48 / 20 10 20 10 HLN 67 45 79 51 / 60 20 10 10 BZN 67 40 80 45 / 80 20 10 10 WEY 59 31 67 35 / 70 20 10 10 DLN 65 39 75 46 / 40 20 10 10 HVR 72 47 79 52 / 20 20 20 10 LWT 62 43 74 47 / 80 30 10 10 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS BILLINGS MT
947 AM MDT SAT JUN 22 2013 .UPDATE... SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS ARE CONTINUING FROM BILLINGS EASTWARD THIS MORNING AS A JET MAX IS DRIVING THIS PRECIPITATION. UPPER TROUGH OVER WESTERN MONTANA THIS MORNING IS PUSHING SLOWLY EASTWARD AND WILL MOVE ACROSS SC/SE MT THIS AFTERNOON. ONLY MAJOR ADJUSTMENT TO THE CURRENT FORECAST WAS TO ADD A CHANCE OF SEVERE THUNDERSTORMS FROM SHERIDAN EAST THROUGH BROADUS TO EKALAKA FROM 21Z AFTERNOON THROUGH 03Z THIS EVENING. CONVECTIVE PARAMETERS ARE HIGHLIGHTING THIS AREA FOR THE POTENTIAL OF LARGE HAIL AND STRONG WINDS. THE UPPER TROUGH WILL BRING IN STRONG Q VECTOR FORCING ALONG WITH JET DYNAMICS. THE ONLY DRAW BACK ON THE SEVERE POTENTIAL THIS AFTERNOON/EVENING WILL BE THE AMOUNT OF SURFACE HEATING THAT WILL TAKE PLACE TODAY. CURRENTLY LOW LEVEL STRATUS HAS BEEN OVER THIS AREA BUT DUE EXPECT SOME BREAKS IN CLOUD COVERE THIS AFTERNOON FOR THE BOUNDARY LAYER TO DESTABILIZE AND STORMS TAPING INTO LOW LEVEL DEW POINTS IN THE LOW TO MID 50S. NO CHANGES MADE TO HIGH TEMPERATURES FOR TODAY. RICHMOND && .SHORT TERM...VALID FOR TDY AND SUN... WIDESPREAD SHOWERS AND STORMS ARE STILL EXPECTED ACROSS THE REGION THIS AFTERNOON AND EVENING AS THE 500-HPA LOW NEAR BOISE AT 09 UTC OPENS UP AND SWINGS ACROSS MT. LOCALLY HEAVY RAINFALL IS LIKELY. FIRST OF ALL...WE WILL INCLUDE SOME PATCHY FOG IN THE FORECAST FOR PLACES LIKE BAKER AND MILES CITY UNTIL 15 UTC. LOW TEMPERATURE-DEW POINT SPREADS AS OF 09 UTC AND HRRR FORECASTS BOTH SUPPORT THAT. TODAY...THE SCATTERED STORMS WHICH HAVE BEEN DEVELOPING OVER SOUTH CENTRAL MT OVERNIGHT SHOULD LARGELY EXIT THE AREA BY 12 UTC AS THE RIGHT ENTRANCE REGION OF THE 75+ KT 300-HPA JET STREAK WHICH SEEMS RESPONSIBLE FOR THIS ACTIVITY HEADS NORTHEAST. MEANWHILE...FORCING TIED TO THE 500-HPA TROUGH MAY BE A BIT DELAYED WHEN COMPARED WITH EARLIER EXPECTATIONS. MOST 00 UTC GUIDANCE PICKED UP ON A BIT OF A SLOW-DOWN WITH THIS SYSTEM...AND THAT LOOKS LIKE A GOOD SIMULATION SINCE WE STILL HAVE A CLOSED LOW INSTEAD OF AN OPEN WAVE ACROSS ID EARLY THIS MORNING. BASED ON THIS...WE DECIDED TO ADVERTISE MAINLY CHANCE POPS ACROSS MUCH OF THE AREA FROM 12 TO 18 UTC...EXCEPT OUT AROUND LIVINGSTON WHERE FORCING MAY ARRIVE BY LATE MORNING. THE 00 UTC MULTI-MODEL CONSENSUS STILL SUPPORTS CATEGORICAL POPS FOR MOST OF THE AREA THIS AFTERNOON WHEN STRONGER VERTICAL MOTION SHOWS UP. PRECIPITABLE WATER VALUES OF 0.75 INCHES OR MORE CERTAINLY SUGGEST LOCALLY HEAVY RAINFALL IS LIKELY. WHILE MID-LEVEL LAPSE RATES WILL BE STEEP ENOUGH TO SUPPORT SOME THUNDER...SEVERE RISK WILL BE KEPT IN CHECK BY A RELATIVELY COOL BOUNDARY LAYER AND RESULTANT LACK OF CAPE. WE WILL BE WATCHING BURN SCAR AREAS CLOSELY...BUT THE THREAT OF FLASH FLOODING WAS NOT SIGNIFICANT ENOUGH FOR A WATCH HEADLINE. FINALLY...NOTE THAT SOME HIGH-ELEVATION SNOW IS LIKELY TODAY BASED ON WET-BULB ZERO HEIGHTS WHICH SUGGEST A SNOW LEVEL PERHAPS AS LOW AS 8700 FT MSL. THE BEARTOOTH HIGHWAY IS A GOOD CANDIDATE FOR SOME SNOW. TONIGHT...BASED ON THE MULTI-MODEL CONSENSUS...WE KEPT CATEGORICAL POPS IN THE FORECAST UNTIL 06 UTC FROM HYSHAM AND SHERIDAN EAST TO BAKER AND EKALAKA. LIKELY POPS ARE EVEN IN PLAY AT BILLINGS DURING THE EVENING. BY THIS POINT IN TIME...DEEP MOIST CONVECTION WILL BE ESTABLISHED OVER PARTS OF THE DAKOTAS AND NEBRASKA...AND THAT DOES POSE THE RISK OF DISRUPTING MOISTURE ADVECTION INTO OUR AREA. EVEN SO...THE EXPECTED QG-FORCING SHOULD STILL YIELD PRECIPITATION EAST OF THE 500-HPA TROUGH AXIS. A DRYING TREND WILL BEGIN ACROSS SOUTH CENTRAL MT OVERNIGHT AS THAT AXIS HEADS EASTWARD. SUN...WE LINGERED SOME CHANCE POPS FROM MILES CITY TO BAKER DURING THE MORNING IN RESPECT TO THE BIT SLOWER DEPARTURE OF THE MID- AND UPPER-LEVEL TROUGH ADVERTISED BY MOST 00 UTC GUIDANCE. WE ACTUALLY EVEN LEFT LOW POPS IN BAKER AFTER 18 UTC. HOWEVER...IN GENERAL THE WHOLE AREA WILL HAVE A DRYING AND WARMING TREND AS FLOW ALOFT WILL BECOME WESTERLY BY AFTERNOON. MIXING TO 700 HPA OR DEEPER BASED ON FORECAST SOUNDINGS SUPPORTS HIGHS WELL INTO THE 70S F. SCHULTZ .LONG TERM...VALID FOR MON...TUE...WED...THU...FRI... EXTENDED FORECAST STARTS MONDAY AS THE FLOW OPENS UP TO THE SOUTHWEST AGAIN. WEAK SHORTWAVES GET PULLED ACROSS THE AREA MONDAY AFTERNOON BUT THE ATMOSPHERE IS PROGGED TO BE FAIRLY DRY SO WILL KEEP POPS LOW. A STRONG SHORTWAVE IS PROGGED BY THE GFS TO SWING ACROSS WESTERN ZONES MONDAY EVENING AND THIS SHOULD GENERATE SCATTERED THUNDERSTORMS AS MOISTURE GETS PULLED IN WITH THIS SYSTEM. THE BEST CHANCE OF PRECIPITATION DURING THE EXTENDED PERIOD LOOKS TO BE ON TUESDAY. HEIGHTS LOWER AS SEVERAL SHORTWAVES DRIFT ACROSS WITH A STRONG WAVE EARLY IN THE DAY. TIMING OF THIS WAVE MAY BE PROBLEMATIC AS IT MAY BE TOO EARLY TO TAP INTO THE STRONGEST INSTABILITY. THAT BEING SAID...PRECIPITABLE WATERS RISE TO OVER THREE QUARTERS OF AN INCH. LOW LEVEL FLOW DOES TURN WESTERLY AND THIS MAY DRY OUT THE LOW LEVELS AND LIMIT PRECIP POTENTIAL. THAT WILL NEED TO BE WATCHED. WILL KEEP SCATTERED POPS IN FOR NOW BUT MAY NEED TO BE LOWERED IN THE FUTURE. A STRONG UPPER RIDGE IS FORECAST TO BUILD WEDNESDAY THROUGH NEXT WEEKEND. SUBTLE DIFFERENCES STARTING TO SHOW UP THOUGH AS THE MODELS JUST NOW STARTED TO BUILD THE RIDGE A LITTLE FARTHER WEST AND SET UP WEAK NORTHWEST FLOW OVER THE AREA. HEIGHTS WERE NOT QUITE AS HIGH AS PREVIOUS RUNS EITHER. THIS WILL BE A TREND TO BE WATCHED AS THE ECMWF HINTED AT THE SAME THING. DID RAISE FORECAST HIGHS THROUGH THE END OF THE WEEK AS 700MB TEMPERATURES WERE A LITTLE TO WARM FOR INHERITED FORECAST HIGHS. TWH && .AVIATION... SHOWERS AND THUNDERSTORMS WILL IMPACT THE FORECAST AREA TODAY. THE MOST WIDESPREAD HEAVY RAINFALL WILL BE EAST OF KBIL TO KSHR. NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED WEST OF THIS LINE AS WELL. MVFR FLIGHT CONDITIONS CAN BE EXPECTED WITH THE HEAVY RAIN. CONDITIONS WILL IMPROVE THIS EVENING IN THE WEST...OVERNIGHT IN CENTRAL ZONES AND EARLY SUNDAY OUT EAST. CHURCH && .PRELIMINARY POINT TEMP/POPS... TDY SUN MON TUE WED THU FRI ------------------------------------------------------- BIL 068 051/078 054/086 062/086 058/085 059/087 058/089 9/T 61/B 11/B 23/T 31/B 10/U 00/U LVM 065 041/079 046/083 054/081 053/083 052/085 053/085 8/T 51/B 13/T 34/T 31/B 11/U 11/U HDN 070 049/078 052/087 059/088 057/087 059/088 059/090 9/T 61/B 11/B 22/T 21/B 11/U 10/U MLS 073 055/079 056/088 062/088 060/087 059/087 060/087 9/T 83/T 11/B 22/T 21/B 10/U 01/U 4BQ 071 049/079 054/087 059/089 058/089 059/089 059/088 9/T 82/T 11/B 22/T 21/B 11/U 11/U BHK 070 053/075 054/086 059/086 058/086 059/083 058/084 8/T 83/T 13/T 32/T 21/U 11/U 11/U SHR 069 045/076 049/085 055/086 053/086 054/086 053/087 +/T 81/U 11/B 22/T 21/B 11/U 11/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
321 AM MDT SAT JUN 22 2013 .SHORT TERM...VALID FOR TDY AND SUN... WIDESPREAD SHOWERS AND STORMS ARE STILL EXPECTED ACROSS THE REGION THIS AFTERNOON AND EVENING AS THE 500-HPA LOW NEAR BOISE AT 09 UTC OPENS UP AND SWINGS ACROSS MT. LOCALLY HEAVY RAINFALL IS LIKELY. FIRST OF ALL...WE WILL INCLUDE SOME PATCHY FOG IN THE FORECAST FOR PLACES LIKE BAKER AND MILES CITY UNTIL 15 UTC. LOW TEMPERATURE-DEW POINT SPREADS AS OF 09 UTC AND HRRR FORECASTS BOTH SUPPORT THAT. TODAY...THE SCATTERED STORMS WHICH HAVE BEEN DEVELOPING OVER SOUTH CENTRAL MT OVERNIGHT SHOULD LARGELY EXIT THE AREA BY 12 UTC AS THE RIGHT ENTRANCE REGION OF THE 75+ KT 300-HPA JET STREAK WHICH SEEMS RESPONSIBLE FOR THIS ACTIVITY HEADS NORTHEAST. MEANWHILE...FORCING TIED TO THE 500-HPA TROUGH MAY BE A BIT DELAYED WHEN COMPARED WITH EARLIER EXPECTATIONS. MOST 00 UTC GUIDANCE PICKED UP ON A BIT OF A SLOW-DOWN WITH THIS SYSTEM...AND THAT LOOKS LIKE A GOOD SIMULATION SINCE WE STILL HAVE A CLOSED LOW INSTEAD OF AN OPEN WAVE ACROSS ID EARLY THIS MORNING. BASED ON THIS...WE DECIDED TO ADVERTISE MAINLY CHANCE POPS ACROSS MUCH OF THE AREA FROM 12 TO 18 UTC...EXPECT OUT AROUND LIVINGSTON WHERE FORCING MAY ARRIVE BY LATE MORNING. THE 00 UTC MULTI-MODEL CONSENSUS STILL SUPPORTS CATEGORICAL POPS FOR MOST OF THE AREA THIS AFTERNOON WHEN STRONGER VERTICAL MOTION SHOWS UP. PRECIPITABLE WATER VALUES OF 0.75 INCHES OR MORE CERTAINLY SUGGEST LOCALLY HEAVY RAINFALL IS LIKELY. WHILE MID-LEVEL LAPSE RATES WILL BE STEEP ENOUGH TO SUPPORT SOME THUNDER...SEVERE RISK WILL BE KEPT IN CHECK BY A RELATIVELY COOL BOUNDARY LAYER AND RESULTANT LACK OF CAPE. WE WILL BE WATCHING BURN SCAR AREAS CLOSELY...BUT THE THREAT OF FLASH FLOODING WAS NOT SIGNIFICANT ENOUGH FOR A WATCH HEADLINE. FINALLY...NOTE THAT SOME HIGH-ELEVATION SNOW IS LIKELY TODAY BASED ON WET-BULB ZERO HEIGHTS WHICH SUGGEST A SNOW LEVEL PERHAPS AS LOW AS 8700 FT MSL. THE BEARTOOTH HIGHWAY IS A GOOD CANDIDATE FOR SOME SNOW. TONIGHT...BASED ON THE MULTI-MODEL CONSENSUS...WE KEPT CATEGORICAL POPS IN THE FORECAST UNTIL 06 UTC FROM HYSHAM AND SHERIDAN EAST TO BAKER AND EKALAKA. LIKELY POPS ARE EVEN IN PLAY AT BILLINGS DURING THE EVENING. BY THIS POINT IN TIME...DEEP MOIST CONVECTION WILL BE ESTABLISHED OVER PARTS OF THE DAKOTAS AND NEBRASKA...AND THAT DOES POSE THE RISK OF DISRUPTING MOISTURE ADVECTION INTO OUR AREA. EVEN SO...THE EXPECTED QG-FORCING SHOULD STILL YIELD PRECIPITATION EAST OF THE 500-HPA TROUGH AXIS. A DRYING TREND WILL BEGIN ACROSS SOUTH CENTRAL MT OVERNIGHT AS THAT AXIS HEADS EASTWARD. SUN...WE LINGERED SOME CHANCE POPS FROM MILES CITY TO BAKER DURING THE MORNING IN RESPECT TO THE BIT SLOWER DEPARTURE OF THE MID- AND UPPER-LEVEL TROUGH ADVERTISED BY MOST 00 UTC GUIDANCE. WE ACTUALLY EVEN LEFT LOW POPS IN BAKER AFTER 18 UTC. HOWEVER...IN GENERAL THE WHOLE AREA WILL HAVE A DRYING AND WARMING TREND AS FLOW ALOFT WILL BECOME WESTERLY BY AFTERNOON. MIXING TO 700 HPA OR DEEPER BASED ON FORECAST SOUNDINGS SUPPORTS HIGHS WELL INTO THE 70S F. SCHULTZ .LONG TERM...VALID FOR MON...TUE...WED...THU...FRI... EXTENDED FORECAST STARTS MONDAY AS THE FLOW OPENS UP TO THE SOUTHWEST AGAIN. WEAK SHORTWAVES GET PULLED ACROSS THE AREA MONDAY AFTERNOON BUT THE ATMOSPHERE IS PROGGED TO BE FAIRLY DRY SO WILL KEEP POPS LOW. A STRONG SHORTWAVE IS PROGGED BY THE GFS TO SWING ACROSS WESTERN ZONES MONDAY EVENING AND THIS SHOULD GENERATE SCATTERED THUNDERSTORMS AS MOISTURE GETS PULLED IN WITH THIS SYSTEM. THE BEST CHANCE OF PRECIPITATION DURING THE EXTENDED PERIOD LOOKS TO BE ON TUESDAY. HEIGHTS LOWER AS SEVERAL SHORTWAVES DRIFT ACROSS WITH A STRONG WAVE EARLY IN THE DAY. TIMING OF THIS WAVE MAY BE PROBLEMATIC AS IT MAY BE TOO EARLY TO TAP INTO THE STRONGEST INSTABILITY. THAT BEING SAID...PRECIPITABLE WATERS RISE TO OVER THREE QUARTERS OF AN INCH. LOW LEVEL FLOW DOES TURN WESTERLY AND THIS MAY DRY OUT THE LOW LEVELS AND LIMIT PRECIP POTENTIAL. THAT WILL NEED TO BE WATCHED. WILL KEEP SCATTERED POPS IN FOR NOW BUT MAY NEED TO BE LOWERED IN THE FUTURE. A STRONG UPPER RIDGE IS FORECAST TO BUILD WEDNESDAY THROUGH NEXT WEEKEND. SUBTLE DIFFERENCES STARTING TO SHOW UP THOUGH AS THE MODELS JUST NOW STARTED TO BUILD THE RIDGE A LITTLE FARTHER WEST AND SET UP WEAK NORTHWEST FLOW OVER THE AREA. HEIGHTS WERE NOT QUITE AS HIGH AS PREVIOUS RUNS EITHER. THIS WILL BE A TREND TO BE WATCHED AS THE ECMWF HINTED AT THE SAME THING. DID RAISE FORECAST HIGHS THROUGH THE END OF THE WEEK AS 700MB TEMPERATURES WERE A LITTLE TOO WARM FOR INHERITED FORECAST HIGHS. TWH && .AVIATION... SHOWERS AND THUNDERSTORMS WILL DRIFT NORTH OF BILLINGS EARLY THIS MORNING. THESE STORMS WILL HAVE HEAVY RAIN PRODUCING LOCAL MVFR FLYING CONDITIONS. MORE SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER SOUTHERN SECTIONS BY LATE MORNING AND DRIFT NORTH TO NORTHEAST THROUGH THE DAY. LOCAL MVFR CONDITIONS CAN BE EXPECTED WITH HEAVY RAIN. THE MOSTLY LIKELY LOCATION FOR THE HEAVIEST RAIN LOOKS TO BE EAST OF A BILLINGS TO SHERIDAN LINE...BUT CERTAINLY SCATTERED STORMS WEST OF THIS LINE WILL CONTAIN HEAVY RAIN TOO. THE SHOWERS WILL SHIFT OUT OF THE WEST THIS EVENING...CENTRAL ZONES OVERNIGHT AND THE EAST EARLY SUNDAY. TWH && .PRELIMINARY POINT TEMP/POPS... TDY SUN MON TUE WED THU FRI ------------------------------------------------------- BIL 068 051/078 054/086 062/086 058/085 059/087 058/089 9/T 61/B 11/B 23/T 31/B 10/U 00/U LVM 065 041/079 046/083 054/081 053/083 052/085 053/085 8/T 51/B 13/T 34/T 31/B 11/U 11/U HDN 070 049/078 052/087 059/088 057/087 059/088 059/090 9/T 61/B 11/B 22/T 21/B 11/U 10/U MLS 073 055/079 056/088 062/088 060/087 059/087 060/087 8/T 83/T 11/B 22/T 21/B 10/U 01/U 4BQ 071 049/079 054/087 059/089 058/089 059/089 059/088 9/T 82/T 11/B 22/T 21/B 11/U 11/U BHK 070 053/075 054/086 059/086 058/086 059/083 058/084 8/T 83/T 13/T 32/T 21/U 11/U 11/U SHR 069 045/076 049/085 055/086 053/086 054/086 053/087 +/T 81/U 11/B 22/T 21/B 11/U 11/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
634 PM CDT SUN JUN 23 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 317 PM CDT SUN JUN 23 2013 MORNING MAP ANALYSIS INDICATES QUASI ZONAL TO SOUTHWESTERLY MID TO UPPER LEVEL FLOW OVER THE WESTERN HALF OF THE CONUS...WITH A LONGWAVE RIDGE OVER THE EAST. A COUPLE OF MID LEVEL SHORT WAVES ARE ALSO NOTED...WITH ONE EXTENDING FROM THE UPPER MISSISSIPPI VALLEY INTO THE NORTHERN PLAINS...AND THE OTHER OVER THE SOUTHWESTERN CONUS. MID TO UPPER LEVEL JET ENERGY EXTENDS FROM THE WEST/SOUTHWESTERN CONUS...EAST/NORTHEAST INTO THE CENTRAL PLAINS...AND THEN NORTH INTO SOUTH CENTRAL CANADA BEFORE FLOWING EAST INTO SOUTHEASTERN CANADA AND PORTIONS OF THE NORTHEASTERN CONUS. MID TO UPPER LEVEL FLOW OVER OUR AREA MAXES OUT AT AROUND 60KTS BETWEEN 300MB AND 200MB PER 12Z SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR IMAGERY ALSO SHOWS THE AFOREMENTIONED MID LEVEL SHORT WAVES...ALONG WITH A PAIR OF CLOSED MID LEVEL LOWS. ONE SUCH LOW IS LOCATED OVER EASTERN ALBERTA AND WESTERN SASKATCHEWAN...AND THE OTHER IS OVER THE PACIFIC JUST OFF THE COAST OF THE NORTHWESTERN CONUS. AT THE SURFACE AN AREA OF LOW BAROMETRIC PRESSURE EXISTS OVER SOUTHWESTERN KANSAS...WITH A FRONTAL BOUNDARY EXTENDING NORTHEAST FROM THE LOW INTO NORTH CENTRAL KANSAS AND SOUTHEASTERN NEBRASKA. THE LOW LEVEL WIND FIELD ACROSS MUCH OF OUR CWA REMAINS FROM THE NORTHEAST FOR THE MOST PART...BUT LOCATIONS ACROSS OUR SOUTHEAST SUCH AS KK82...KK61...AND KHJH ARE ALL OBSERVING A SURFACE WIND FROM THE SOUTHEAST. GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN SUGGESTS THE LOW LEVEL BAROCLINIC ZONE WILL PERSIST OVER SOUTHEASTERN PORTIONS OF OUR CWA THIS EVENING INTO TONIGHT BEFORE SURGING NORTH DURING THE DAY MONDAY. THERE ARE INDICATIONS...ESPECIALLY FROM HIGHER RESOLUTION MODELS SUCH AS THE NAM12...OF VERY SUBTLE MID LEVEL PERTURBATIONS MOVING OVERHEAD WITHIN THE MEAN FLOW THIS AFTERNOON AND THIS EVENING. CONFIDENCE ON SUCH A FEATURE PROMOTING PRECIPITATION PRODUCTION ACROSS OUR AREA THIS AFTERNOON AND EVENING REMAINS VERY LOW HOWEVER AND AS A RESULT...WILL CONTINUE RELEGATING ANY AFTERNOON AND EVENING POPS TO OUR SOUTH/SOUTHEASTERN CWA...IN CLOSEST PROXIMITY TO THE AFOREMENTIONED LOW LEVEL BAROCLINIC ZONE AND RESULTANT AXIS OF ENHANCED LOW LEVEL CONVERGENCE AND LIFT. AS FOR THE TIMING OF CONVECTIVE INITIATION THIS AFTERNOON AND EVENING...FORECAST PROXIMITY SOUNDINGS FROM THE NAM...OPERATIONAL GFS...AND RAP ALL SUGGEST A HEALTHY CAP PERSISTING THROUGH AT LEAST 00Z. GIVEN THIS...ITS HARD TO BUY INTO QPF FIELDS FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN...WHICH ALL SUGGEST WIDESPREAD PRECIPITATION WILL BE REALIZED ACROSS PORTIONS OF OUR SOUTHEAST BEFORE 00Z THIS EVENING. HRRR SIMULATED REFLECTIVITY LOOKS MUCH MORE REASONABLE...SUGGESTING VERY ISOLATED CONVECTION OCCURRING ACROSS OUR SOUTHEAST TOWARDS 00Z. GIVEN ALL THIS...CONFIDENCE IS VERY LOW THAT MUCH PRECIPITATION WILL BE REALIZED ACROSS OUR AREA PRIOR TO 00Z...BUT CANNOT COMPLETELY RULE OUT SUCH A SOLUTION AND WILL MAINTAIN ~20% POPS ACROSS OUR SOUTHEAST 23-00Z. 00Z AND BEYOND...FORECAST PROXIMITY SOUNDINGS SUGGEST THE CAPPING INVERSION WILL WEAKEN SOMEWHAT THUS MAKING CONVECTION SOMEWHAT MORE LIKELY...A SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN...AS WELL AS SIMULATED REFLECTIVITY FROM THE HRRR. GIVEN THIS...WILL GO AHEAD WITH SLIGHTLY HIGHER POPS...~%30...00-06Z ACROSS OUR SOUTHEAST. SHOULD SURFACE-BASED CONVECTION BE REALIZED THIS AFTERNOON AND/OR EVENING...THEN SEVERE WEATHER WILL LIKELY RESULT WITH DEEP LAYER MUCAPE VALUES IN THE 2000-4000J/KG WAITING FOR UPDRAFT PRODUCTION AND 30-35KTS OF DEEP LAYER BULK SHEAR FOR UPDRAFT ENHANCEMENT. CERTAINLY LARGE HAIL AND MICROBURST-RELATED WIND GUSTS WILL BE A THREAT...BUT ENHANCED HORIZONTAL VORTICITY IN THE VICINITY OF THE LOW LEVEL BAROCLINIC ZONE COULD ALSO PROMOTE ISOLATED TORNADIC ACTIVITY. WILL CONTINUE SUCH WORDING IN THE HWO AS A RESULT. HEADING INTO THE OVERNIGHT HOURS TONIGHT...THE AXIS OF A ~45KT 850MB JET STREAK IS EXPECTED TO DEVELOP ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS...WITH THE NOSE OF THIS LOW LEVEL JET MOVING INTO SOUTHERN PORTIONS OF OUR CWA BETWEEN 06Z AND 12Z. SHOULD DEEP CONVECTION BE ONGOING ALONG THE LOW LEVEL BAROCLINIC ZONE...THEN INCREASING LOW LEVEL THERMAL ADVECTION ALONG THE AXIS OF THE LOW LEVEL JET COULD CERTAINLY HELP INCREASE SPATIAL COVERAGE OF SAID CONVECTIVE ACTIVITY. ALSO...IN ADDITION TO POSSIBLE THUNDERSTORM ACTIVITY OVER PORTIONS OF OUR CWA THIS AFTERNOON AND EVENING...THUNDERSTORMS ALSO REMAIN POSSIBLE OVER THE CENTRAL HIGH PLAINS. SHOULD HIGH PLAINS CONVECTION DEVELOP THIS AFTERNOON/EVENING AND MOVE EAST TOWARDS OUR AREA TONIGHT...ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY COULD BE REALIZED OVER OUR AREA TONIGHT...ESPECIALLY OUR WEST. THIS IS A SOLUTION SUPPORTED BY THE NAM...OPERATIONAL GFS...SREF-MEAN...AND HRRR. GIVEN ALL THIS...WENT AHEAD WITH RELATIVELY HIGHER POPS ACROSS MUCH OF THE CWA STARTING AROUND 06Z. SEVERE WEATHER COULD CERTAINLY BE POSSIBLE DURING THE EARLY PART OF THE OVERNIGHT HOURS AS THE MORE ROBUST CONVECTION FROM EARLIER IN THE EVENING...SHOULD IT DEVELOP...MAINTAINS ITSELF. THAT BEING SAID...BARRING THE DEVELOPMENT OF AN MCS ACROSS THE REGION...CONVECTIVE ACTIVITY SHOULD WANE IN INTENSITY AS POTENTIAL INSTABILITY DECREASES 06Z ONWARD. THERE COULD SOME LINGERING SHOWER AND THUNDERSTORM ACTIVITY ACROSS OUR AREA AROUND SUNRISE MONDAY...BUT OTHERWISE MONDAY DURING THE DAY IS EXPECTED TO REMAIN DRY FOR THE MOST PART AS THE WARM FRONT SURGES NORTH AND AN OVERALL LACK IN KINEMATIC FORCING OVERTAKES THE AREA. AT THIS TIME THE ONLY REAL THREAT FOR PRECIPITATION DURING THE DAY MONDAY APPEARS AS THOUGH IT WILL RESIDE OVER OUR SOUTHWESTERN CWA DURING THE LATE AFTERNOON AND EVENING HOURS...WHICH IS WHERE AND WHEN GUIDANCE SUGGESTS AN ADVANCING LOW LEVEL DRY LINE WILL BULGE EAST. AN AREA OF LOCALLY ENHANCED CONVERGENCE AND LIFT IN THE VICINITY OF THIS DRY LINE BULGE...WORKING IN CONCERT WITH DIABATIC HEATING...MAY BE ENOUGH TO INITIALIZE ISOLATED SHOWER AND THUNDERSTORM DEVELOPMENT AND AS A RESULT...~20% POPS ARE FORECAST 21Z MONDAY THROUGH 00Z TUESDAY ACROSS OUR SOUTHWEST. SHOULD THUNDERSTORM ACTIVITY BE REALIZED LATE MONDAY AFTERNOON AND/OR EVENING...THEN DEEP LAYER MUCAPE VALUES OF 2000-3000J/KG...ALONG WITH DEEP LAYER BULK SHEAR VALUES OF ~30KTS...WILL BE AVAILABLE FOR UPDRAFT PRODUCTION AND ENHANCEMENT. GIVEN THIS...WILL GO AHEAD AND HIGHLIGHT THE THREAT FOR ISOLATED SEVERE WEATHER ACROSS OUR SOUTHWEST MONDAY AFTERNOON AND EVENING. FINALLY...INCREASING SOUTHERLY FLOW WILL LIKELY BE OBSERVED MONDAY AFTERNOON ONCE THE SURFACE WARM FRONT SURGES NORTH. GUIDANCE SUGGESTS A SUSTAINED WIND OF ~24KTS...WITH HIGHER GUSTS APPROACHING 35KTS...WILL BE REALIZED PRIMARILY ACROSS NORTH CENTRAL KANSAS. AS A RESULT...WILL CONTINUE MENTIONING SUCH CONDITIONS IN THE HWO. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 317 PM CDT SUN JUN 23 2013 MONDAY NIGHT...A VORT MAX LOCATED OVER THE HIGH PLAINS WILL TRACK EAST ACROSS THE FORECAST AREA. THUNDERSTORMS THAT INITIALLY FORM ACROSS THE HIGH PLAINS DURING THE MONDAY AFTERNOON HOURS WILL SLIDE EAST DURING THE EVENING AND OVERNIGHT HOURS...AND IF THEY HOLD TOGETHER MAY BRING RAIN TO PORTIONS OF THE FORECAST AREA. IN ADDITION TO RAIN...SOME OF THESE THUNDERSTORMS MAY BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS POSSIBLE DURING THE EVENING HOURS. INSTABILITY IS HIGH AND DEEP LAYER SHEAR IS MORE MODEST BUT SUFFICIENT FOR SEVERE STORMS. THE LIMITING FACTOR WILL BE THE WARM MID LEVEL CAP AND THUS CONFIDENCE IN THUNDERSTORM DEVELOPMENT AND COVERAGE IS STILL FAIRLY LOW WITH SLIGHT POPS. THE 12Z ECMWF AND 12Z NAM FAVOR OUR WEST AND NORTH FOR STORMS...WHILE THE 12Z GFS HIGHLIGHTS OUR SOUTHEASTERN ZONES. THE ECMWF AND NAM MAKE MORE SENSE WITH FAVORING NORTH AND WEST ZONES BASED ON THE EXPECTED UPPER WAVE LOCATION AND THE INCREASING STRENGTH OF THE CAP AS YOU HEAD SOUTH. TUESDAY AND WEDNESDAY...THE PATTERN WILL BE FAIRLY ZONAL WITH ALL OF THE BETTER UPPER FLOW AND SHORT WAVES TRACKING ACROSS THE NORTHERN TIER STATES. AN UPPER RIDGE WILL SLOWLY BEGIN TO BUILD ACROSS THE SOUTHWEST CONUS STARTING ON WEDNESDAY. A SFC TROUGH AXIS WILL TRACK EAST THROUGH OUR FORECAST AREA LATE ON TUESDAY AND TURN THE WINDS TO NORTHERLY BY WEDNESDAY. HOWEVER...A STRONG CAP SHOULD RESULT IN DRY CONDITIONS FOR MOST AREAS AND WILL CONTINUE TO CALL FOR A DRY FORECAST...BUT CAN NOT COMPLETELY RULE OUT AN ISOLATED THUNDERSTORM...HENCE THE 10 PERCENT POPS. TUESDAY WILL BE SCORCHER WITH HIGHS WELL INTO THE 90S ACROSS NEBRASKA TO OVER 100 ACROSS MUCH OF NORTHERN KANSAS. TEMPERATURES WILL FALL A FEW DEGREES WITH THE NORTH WINDS ON WEDNESDAY...BUT CONTINUE TO EXPECT 90S FOR HIGHS. THURSDAY THROUGH SUNDAY...THERE IS A SHIFT IN THE UPPER PATTERN AS AN UPPER RIDGE STRENGTHENS ACROSS THE ROCKIES AND AN UPPER TROUGH PERSISTS ACROSS THE EASTERN CONUS. THIS WILL RESULT IN NORTHWESTERLY FLOW ALOFT FOR OUR FORECAST AREA. MOST AREAS WILL BE DRY THROUGHOUT THIS PERIOD GIVEN A LACK OF FORCING. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS ON THURSDAY INTO THURSDAY NIGHT...BUT MOST RESENT MODEL RUNS ARE STARTING TO BACK OFF OF THIS ALREADY RATHER SLIGHT CHANCE OF PRECIPITATION. ANOTHER WEAK COOL FRONT WILL TRY TO WORK ITS WAY THROUGH AT SOME POINT THURSDAY NIGHT OR FRIDAY...BUT THURSDAY SHOULD STILL BE A HOT DAY WITH 90S ACROSS NEBRASKA TO NEAR 100 IN KANSAS. THE COOLER WEATHER WILL SETTLE IN ON FRIDAY AND SATURDAY WITH EASTERLY TO NORTHEASTERLY SFC WINDS. THIS COOLER FETCH SHOULD DROP HIGHS BACK INTO THE LOWER AND MID 90S ON FRIDAY...AND THEN 80S ACROSS NEBRASKA TO LOWER 90S OVER KANSAS ON SATURDAY. TEMPERATURES BEGIN TO WARM BACK UP ON SUNDAY WITH EVERYONE BACK IN THE 90S. OVERALL...TEMPERATURES WILL NOT VARY THAT MUCH AND REMAIN RATHER TOASTY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 622 PM CDT SUN JUN 23 2013 CIGS AT KGRI HAVE INTERMITTENTLY DROPPED TO MVFR...BUT LOOK FOR OVERALL SCATTERED MVFR TO VFR CLOUDS THIS EVENING. WINDS WILL BE LIGHT AND VARIABLE AS A WARM FRONTAL BOUNDARY RESIDES JUST SOUTH OF THE TERMINAL. AN OUTSIDE OF THUNDERSTORMS EXIST DURING THE OVERNIGHT HOURS AS CONVECTION ALONG THE HIGH PLAINS ROLLS EASTWARD. AS THE WARM FRONT LIFTS NORTH...SOUTHERLY WINDS WILL INCREASE ON MONDAY WITH GUSTS NEAR 25KTS POSSIBLE. CLOUDS SHLD REMAIN AT VFR LEVELS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...BRYANT LONG TERM...WESELY AVIATION...FAY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
343 PM CDT SAT JUN 22 2013 .DISCUSSION... THUNDERSTORM CHANCES THROUGH SUNDAY OR MONDAY...THEN WARMING NEXT WEEK...REMAIN THE PRIMARY FORECAST CONCERNS. THUNDERSTORMS THAT DEVELOPED IN WESTERN NEBRASKA FRIDAY AFTERNOON/EVENING HELD TOGETHER OVERNIGHT FUELED BY THETA-E ADVECTION ON NOSE OF LOW LEVEL JET. STORMS SWEPT ACROSS MUCH OF EASTERN NEBRASKA AND WEST CENTRAL IOWA DURING THE MORNING BUT HAD DECREASED MARKEDLY BY LATE MORNING. ATTENDANT CLOUD SHIELD HELD TEMPERATURES DOWN MUCH OF THE MORNING...BUT RETURNING SOUTH WINDS AND MORE SUNSHINE THIS AFTERNOON PUSHED TEMPERATURES TOWARD OR ABOVE 90 IN ALL BUT NORTHEAST NEBRASKA WHERE TEMPS LAGGED IN THE UPPER 70S OR LOWER 80S. DEW POINTS WERE BETWEEN 65 AND 70. LOOKS LIKE MORNING CONVECTION HAS STABILIZED ATMOSPHERE FOR LATE AFTERNOON ACTIVITY FOR THE MOST PART. RAP MESOANALYSIS SHOWS MUCAPE VALUES WELL OVER 2000 J/KG IN THE SOUTHERN HALF OF THE CWA...BUT LOW LEVEL CONVERGENCE IS NEGLIGIBLE. MEANWHILE IN THE NORTHEAST WHERE SOME SURFACE CONVERGENCE IS NOTED...COOLER SURFACE TEMPS BEHIND EXITING CONVECTION HAS KEPT MUCAPE LOW. EXPECT THAT TO ERODE LATER THIS EVENING AS A MID LEVEL IMPULSE MOVING OUT OF EASTERN COLORADO/WYOMING COOLS MID LEVEL ATMOSPHERE AS SURFACE TEMPERATURES REBOUND SOMEWHAT. BETTER CHANCES FOR EVENING CONVECTION LIES TO OUR WEST WHERE CAPES ARE INCREASING AND CAP DIMINISHING...AND LATEST MESO DISCUSSIONS FROM SPC SUGGEST WATCH IS LIKELY FOR PARTS OF WESTERN AND CENTRAL NEBRASKA. THESE STORMS WILL MOVE NORTHEAST TOWARD NORTHEAST NEBRASKA...THEN PROPAGATE SOUTHEAST WITH TIME AS LOW LEVEL JET KICKS IN OVERNIGHT...PROBABLY REACHING THE I-80 CORRIDOR LATE TONIGHT. SEVERE THREAT SHOULD WANE AFTER MIDNIGHT...BUT ANY OF THE STRONGER STORMS COULD PRODUCE WIND AND POSSIBLY HAIL AS FREEZING LEVELS HAVE COME DOWN SOME FROM YESTERDAY. WOULD EXPECT A DECREASING TREND AGAIN SUNDAY MORNING...THEN REDEVELOPMENT IN THE AFTERNOON ALONG COLD FRONT THAT WILL BE DRIFTING INTO THE NORTHWEST CWA IN THE MORNING. WHERE THAT FRONT WILL SET UP WILL BE AFFECTED BY MORNING CONVECTION...BUT MOST LIKELY WILL LIE SOMEWHERE CLOSE TO I-80 CORRIDOR IN THE AFTERNOON. SUNSHINE AND POOLING DEW POINTS ALONG FRONT WILL YIELD CAPES CLOSE TO 3000 J/KG ALONG WITH 30KT 0-6KM SHEAR. FRONTAL CONVERGENCE UNDER STEEP LAPSE RATES NEAR 8 C/KM SUGGEST STORMS WILL FIRE LATE IN THE DAY AS CAP WEAKENS. ALL MODES OF SEVERE ARE POSSIBLE...AS SHEAR/INSTABILITY AND LOWERING FREEZING LEVELS POINT TO WIND AND HAIL. AND LOW LEVEL VORTICITY/HELICITY/EHI SUPPORT AN ISOLATED TORNADO THREAT. EXPECT STORMS TO CONTINUE THROUGH THE EVENING WITH SEVERE THREAT GRADUALLY DIMINISHING LATE IN THE EVENING. AGAIN ANOTHER ROUND OF STORMS FROM THE HIGH PLAINS MAY ROLL ACROSS NORTHERN CWA AFTER MIDNIGHT. AFTER MORNING CONVECTION MONDAY...MUCH OF NEXT WEEK LOOKS DRY AS HEIGHTS BUILD FROM THE SOUTHWEST AND SOUTH INTO THE CENTRAL PLAINS. HOWEVER ANOTHER ROUND OF STORMS MONDAY AFTERNOON...BUT WOULD FAVOR AREAS NORTH OF NEBRASKA. BY LATE IN THE WEEK...A MID LEVEL TROUGH DEEPENING NEAR AND NORTH OF THE GREAT LAKES COULD DRIVE A BACKDOOR COLD FRONT INTO OUR AREA. MODELS REMAIN BEARISH WITH PRECIP CHANCES THEN...BUT SLIGHTLY COOLER AIR WILL FOLLOW. LOOKS LIKE HIGHS IN THE 90S WILL BE COMMON THROUGH MUCH OF THE WEEK...WITH 80S FRIDAY AND SATURDAY. DERGAN && .AVIATION...18Z TAFS FOR KOMA...KLNK...AND KOFK. SOUTHEAST WINDS WILL REMAIN STRONG 14 TO 22KTS SUSTAINED WITH GUSTS 20 TO 30KTS...DECREASING TONIGHT...HOWEVER LLWS DEVELOPS BY 06Z. VFR CONDITIONS FOR NOW WITH BREAK IN THE PRECIPITATION. THUNDERSTORMS MAY DEVELOP IN THE KOFK AREA LATER THIS AFTERNOON OR EVENING...HOWEVER FOR NOW INCLUDED MVFR VSBYS WITH THE PRECIPITATION LATER THIS EVENING AND OVERNIGHT AT ALL THREE SITES. ZAPOTOCNY && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
251 PM EDT SAT JUN 22 2013 .SYNOPSIS... HIGH PRESSURE BUILDING INTO THE NORTHEAST WILL BRING WARM TEMPERATURES TO THE REGION. INCREASING HUMIDITY LEVELS MAY PROVIDE THE SPARK FOR A FEW AFTERNOON THUNDERSTORMS THROUGH THE PERIOD. AN UPPER LEVEL TROUGH WILL SKIRT THROUGH BY MID-WEEK WITH A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... 250 PM UPDATE... SHOWERS HV DVLPD ACRS SRN ONTARIO THIS AFTN IN CONJUNCTION WITH S/WV. APPEARS AS THO THE BULK OF THESE SHOWERS/TSTMS WL GO ACRS NRN ZONES GNRLY NORTH OF THE THRUWAY. ANOTHER LINE OF STORMS IS DVLPNG ACRS WRN OH AND SLOWLY TRYING TO FILL IN IN CONVERGENCE ZONE AND POOLING DWPTS. THE LATEST HRRR MODEL DATA THIS WL FILL IN ACRS WRN PA AND THEN BREAK UP AS IT HEADS FURTHER EAST AWAY FM CONVERGENT AXIS THEREFORE EXPECT CH THUNDER AFT 00Z OVR FAR NRN ZONES AND ISOLD AT BEST ACRS REMAINDER OF NY CNTYS WITH LOSS OF DAYTIME HTG. FCST FOR TONIGHT WL BE COMPLICATED BY TWO POTENTIAL ISSUES. ANY MCS THAT MAY DVLP ACRS THE NRN PLAINS SPREADING HIGH CIRRUS INTO AREA. A CLOSED H5 LOW WL DRIFT NORTHWARD FM THE SERN U.S. IN AREA OF STRONGEST HEIGHT FALLS PER 12Z RAOBS. QUESTION WL BE HOW QUICKLY THESE CLDS WL IMPACT AREA AND THE RESULT ON FOG DVLPMNT. FOR NOW HV GONE WITH MOCLDY ACRS NRN ZONES DUE TO BEING CLOSER IN PROXIMITY TO MAIN STORM TRACK AND STATIONARY BNDRY IN WHICH ANY SUBTLE S/WVS MAY RIDE ALONG. FURTHER TO THE SOUTH, AT LEAST INITIALLY TONIGHT SKIES WL BE MOCLR AS UL RIDGE BUILDS IN AHD OF H5 LOW EJECTING NORTH. AFT 06Z FCST WL BE TOTALLY DEPENDENT ON HOW FAST SYSTEM CAN MV NWRD. LATEST CMC CLD FCST INDICATING CLR SKIES ALL THE WAY THRU 12Z. 12Z NAM AND GFS INDICATE RIDGE FLATTENING SLIGHTLY TONIGHT AND ALLOWING CLDS TO SPILL DOWN INTO NEPA THEN PUMPING BACK UP TWD 12Z. FOR NOW, HV CALLED IT PCLDY AFT 06Z THO THIS MAY NEED TO BE TWEAKED BY LATER SHIFTS. AS FOR FOG POTENTIAL BL IS CERTAINLY MOIST ENUF AND WITH RVR VLYS DROPPING DOWN THIS MRNG, SEE A REPEAT OF THIS, IF CLRNG CAN DEVELOP ACRS SRN TIER AND POINTS SOUTH. THEREFORE WL KEEP PATCHY FOG IN GRIDS STARTING AT 09Z AND THEN SCATTERING OUT BY 13Z. EXPECT OVRNGT MINS TO RMN IN THE 60S AREAWIDE DUE TO CLD CVR AND H8 TEMPS INCRSG DUE TO CONTD WAA. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... 250 PM UPDATE... SHORT TERM WL RMN AS IS WITH A CHC OF DIURNAL CONVECTION EACH AFTN AND POTENTIAL FOR RVR VLY FOG OVRNGT. HIGHS WL TOP OUT IN THE M/U 80S EACH DAY WITH MINS DIPPING INTO THE 60S. H5 LOW WL EJECT THRU OH VLY SUNDAY NGT WITH CHC FOR RENEGADE STORMS AT ANYTIME ACRS THE CWA. THUS, WL KEEP MENTION OF ISOLD POPS IN FOR MOST OF THE AREA THRU 12Z MONDAY. MAIN TROF WL ZIP THRU AREA ON MONDAY WITH BETTER CHC FOR CONVECTION DRG THE AFTN. WV AFT WV WL PERSIST THRU THE END OF THE SHORT TERM WITH CHC POPS EACH DAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MOST OPERATIONAL MODELS AND ENSEMBLES SUGGEST THAT THE PATTERN WILL BECOME INCREASINGLY CYCLONIC ACROSS THE NORTHEASTERN US DURING THE UPCOMING WEEK. THIS WILL TEND TO INCREASE THE CHANCES FOR UNSETTLED CONDITIONS...ESPECIALLY HEADING THROUGH THURSDAY AND FRIDAY WITH THE WPC ANALYSTS INDICATING THE PASSAGE OF WARM AND COLD FRONTS EACH DAY. WITH ONLY BROAD FORCING NOTED IN THE MODELS... NOTHING REALLY SUGGESTS THAT WE WILL BE FACING A PROLONGED SOAKING EVENT...UNTIL POSSIBLY A SHOT WITH THE FRONTS ON FRIDAY...IF IT OCCURS. WPC GUIDANCE SUGGESTED 60-70 POPS ON THURS-FRI BUT THIS IS SUMMER TIME AND CONFIDENCE IS USUALLY NOT HIGH ENOUGH TO GO SO FAR ABOVE CLIMO AT DAYS 6-7 SO HAVE GONE BELOW THE GUIDANCE AND EVEN A TAD LOWER THAN OUR PREV FORECAST ACROSS THE BOARD GIVEN SUCH UNCERTAINTY. HAVE ALSO NUDGED MAX TEMPERATURES UP HIGHER THAN RECOMMENDED GUIDANCE GIVEN LITTLE BUDGE IN THE ECMWF/GFS THERMAL FIELDS WHICH SUGGEST ABOVE NORMAL TEMPERATURES BY 1-2 STANDARD DEVIATIONS FOR MUCH OF THE WEEK UNTIL THE TROF REALLY KICKS IN GOING INTO NEXT WEEKEND. SHOULD EASILY SEE UPPER 80S-AROUND 90 WEDNESDAY FOLLOWED BY TEMPS REMAINING IN THE LOW-MID 80S ONLY TEMPERED BY CLOUDS AND SHOWERS. MUGGY LOW-MID 60S WILL BE COMMON FOR LOWS. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... MINOR DISTURBANCE MOVING ACROSS LOWER ONTARIO WILL ENTER N CNTRL NY EARLY THIS AFTERNOON WITH A PERIOD OF SHRA/TSRA AFFECTING KSYR-KRME. DIFFICULT TO ASSESS SOUTHERN EXTENT OF CONVECTIVE DEVELOPMENT GIVEN BALANCE BETWEEN DESTABILIZATION AND MID-LEVEL THERMAL CAPPING. FOR NOW...HAVE NOT INCLUDED ANY TSRA SOUTH OF KSYR-KRME ALTHOUGH SOME MODEL FORECASTS SUGGEST THAT KITH-KBGM AREAS WILL NEED TO BE MONITORED FOR CB DEVELOPMENT. BEYOND 00Z TONIGHT...THE CONFIDENCE FOR CONVECTIVE DEVELOPMENT WANES PRETTY QUICKLY AND HAVE NOT INCLUDED IN THIS UPDATE...ALTHOUGH MODELS HAVE POTENTIAL ACTIVITY THROUGH 06Z...BUT WILL PLAY TYPICAL DIURNAL TRENDS ATTM. THE MORE TROUBLESOME CONSIDERATIONS ARE FOR IFR AND ALTERNATE VSBY RESTRICTIONS DUE TO FOG AND HAZE AS LOW LEVEL MOISTURE WILL BE INCREASING WITH TIME. I SEE ENOUGH EVIDENCE AT THIS TIME TO INCLUDE SOME OVERNIGHT MVFR EXTENDING ACROSS MOST TERMINALS WITH IFR LIKELY DEVELOPING AT KELM. LOW LEVEL STRATOCU CIGS ARE ALSO IN THE REALM OF POSSIBILITY AND HAVE TAGGED A SCT 010-020 FOOT LAYER ONTO THE VSBY RESTRICTIONS AT SVRL LOCATIONS TO AT LEAST HINT AT THAT POTENTIAL. WINDS GENERALLY 5-10 KTS FROM THE SOUTHWEST THIS AFTERNOON AND SUNDAY WITH LIGHT LOCAL DRAINAGE FLOW TONIGHT. OUTLOOK...SUN THRU WED...VFR MOST OF THE TIME. MVFR VSBY AND CIG RESTRICTIONS POSSIBLE WITH PASSING SHRA OR TSRA. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...PVN NEAR TERM...PVN SHORT TERM...PVN LONG TERM...JAB AVIATION...JAB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
333 AM EDT SAT JUN 22 2013 .SYNOPSIS... HIGH PRESSURE ANCHORED OFF THE ATLANTIC COAST WILL KEEP THE NORTH COUNTRY DRY TODAY WITH PARTLY TO MOSTLY SUNNY SKIES THIS AFTERNOON AND TEMPERATURES IN THE MID 70S TO LOWER 80S. A WARM FRONT WILL MOVE SLOWLY THROUGH THE AREA ON SATURDAY WITH SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM WITH TEMPERATURES AGAIN RANGING THROUGH THE 70S NORTHEAST TO THE LOWER 80S SOUTHWEST. EVEN WARMER AND MORE HUMID CONDITIONS ARE EXPECTED SUNDAY INTO NEXT WEEK...WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND EVENING HOURS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1250 AM EDT SATURDAY...INHERITED FORECAST IN GOOD SHAPE WITH ONLY UPDATE NEEDED TO INCREASE SKY COVER AS CONVECTIVE DEBRIS CLOUDS ARE FILLING INTO THE REGION. WITH INCREASED CLOUD COVER TEMPS SHOULD HOLD FAIRLY STEADY FOR THE REMAINDER OF THE NIGHT IN THE 50S. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/... AS OF 323 PM EDT FRIDAY...SATURDAY...MODERATE CONFIDENCE CONTINUES THAT WE`LL SEE SOME SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM AS THE DECAYING MCV AND SHORT WAVE TROF MOVES ACROSS THE REGION DURING MIDDAY INTO THE EARLY EVENING. MODEL GUIDANCE HAS BEEN STRUGGLING WITH THE PLACEMENT OF THIS FEATURE WITH THE GFS MORE WIDESPREAD AND FURTHER SOUTH AND THE NAM FURTHER NORTH. HAVE PLAYED IT MORE TOWARD THE GFS/MAV SOLUTION AS RAP ANALYSIS SHOWS SIGNIFICANT MCV HAS FORMED. SO HIGHER POPS THAN WHAT THE NAM MOS SUGGESTS AND SLIGHT COOLER TEMPERATURES. HAVE STAYED MAINLY NEAR 80 WITH COOLER TEMPS NORTHEAST AND WARMER SOUTHWEST. WHERE CLOUDS/SHOWERS HANG ON IT COULD BE 5 DEGREES COOLER AND WHERE THEY DISSIPATE 5 DEGREES WARMER. IN THE ABSENCE OF ANY LARGE SCALE FORCING...ANY CONVECTIVE ACTIVITY WILL DISSIPATE GOING INTO THE EVENING AND OVERNIGHT HOURS SAT NIGHT WITH LOWS MAINLY IN THE 60S. ON SUNDAY...MORE TYPICAL ISOLATED TO SCATTERED AIRMASS TYPE PULSE SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN ON SUNDAY MAINLY IN THE MID TO LATE AFTERNOON/EVENING WITH ACTIVITY SETTLING DOWN OVERNIGHT SUNDAY NIGHT. CAPE VALUES NOT ALL THAT IMPRESSIVE (BELOW 100 J/KG) WITH GFS SUGGESTING A CAPPING SUBSIDENCE INVERSION MAY BE IN PLACE SO KEPT A MINIMAL CHANCE POPS IN THE FORECAST. IT SHOULD BE CONSIDERABLY WARMER AND MORE HUMID AIR PUSHES IN AS THE WARM FRONT LIFTS NORTHEAST SUNDAY WITH HIGHS IN THE 80S. SUNDAY NIGHT SHOULD BE VERY MILD WITH READINGS IN THE 60S PERHAPS NEAR 70 AT BTV WITH WARM AND HUMID AIR FIRMLY ENTRENCHED. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 333 AM EDT SATURDAY...FOR THE EXTENDED PERIOD...BROAD UPPER RIDGE ACROSS THE SOUTHERN HALF OF THE COUNTRY COMBINED WITH STRONG SFC RIDGE OFFSHORE WILL ALLOW FOR WARM TEMPS ACROSS THE AREA THRU THE PERIOD. ACCOMPANYING THESE EXPECTED TEMPS WILL ALSO BE THE CHANCE FOR RW/TRW. MDLS CONTINUE TO SHOW ZONAL FLOW OVER THE NORTHERN PORTION OF THE COUNTRY AS A RESULT OF UPPER RIDGE TO THE SOUTH. 850/925 TEMPS RANGING FROM +16C TO +20C WILL BRING DAYTIME HIGHS WELL INTO THE 80S W/ SOME LOCAL 90F...ESPECIALLY FOR FIRST HALF OF EXTENDED. THE LATTER PORTION WILL TAPER DOWN TO NEAR 80F AS BROAD TROUGH WORKING OUT OF THE GREAT LKS REGION BREAKS DOWN UPPER RIDGE...ALLOWING FOR INCR CHANCES FOR CLDS/MOISTURE W/ BROAD SW FLOW SETTING UP. OVERNGT LOWS IN THE 50S TO M60S. OVERALL FOR PRECIP...STILL EXPECTING SCT RW/TRW THRU WEDNESDAY AS WK SHORTWAVES WORK ALONG NORTHERN FRINGE OF UPPER RIDGE...FOLLOWED BY MORE AREAL COVERAGE IN TRW/RW AS LOW FROM GREAT LKS APPROACHES. SOME MDL DIFFERENCES FOR TIMING/PLACEMENT OF TROUGH FOR THURS/FRI...SO WILL KEEP OVERALL CHANCE POPS IN ATTM. W/ AIRMASS ON THE HUMID SIDE THRU PERIOD...HIGH PW CONTENT OF NEAR 1.50" WILL CREATE THE POTENTIAL FOR SOME HEAVY DOWNPOURS IN ANY TRW THAT DOES DEVELOP...ESPECIALLY THURS/FRI. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... THROUGH 06Z SUNDAY...VFR COND THRU MUCH OF FORECAST PERIOD. EXPECTING MID CLD COVER AROUND BKN100-150 TO TRANSLATE DOWN TO BKN035-080 THIS AFTNOON AS WX SYSTEM APPROACHES. MSS/SLK WILL SEE MVFR COND WITH CEILINGS DOWN NEAR BKN030 AND -RW DRIVING DOWN TO 5-6SM AT TIMES BY 00Z SUN. AFT MIDDAY...VCSH/-SHRA POSSIBLE FOR ALL AREAS. WINDS GENERALLY RANGING FROM SE TO SW 5-10KTS. OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY... MAINLY VFR CONDITIONS WL PREVAIL THRU THE TIME PERIOD WITH THE EXCEPTION OF BRIEF MVFR/IFR IN THE HEAVIER SHOWERS/STORMS. BEST CHCS FOR STORMS WL BE DURING THE AFTERNOON AND EARLY EVENING HRS THRU TUESDAY. IN ADDITION...SOME PATCHY EARLY MORNING FOG/BR WITH MVFR/IFR WL BE POSSIBLE IF ANY TAF SITE RECIEVES HEAVY RAINFALL FROM CONVECTION DURING THE DAYTIME. EXPECT MAINLY SOUTHERLY WINDS THRU THE PERIOD. && .EQUIPMENT... OBSERVATIONS FROM RUTLAND-SOUTHERN VERMONT REGIONAL AIRPORT (KRUT) REMAIN UNAVAILABLE DUE TO A TELEPHONE COMMS LINE ISSUE. THE FAA AOCC IS AWARE OF THE ISSUE...BUT THERE IS NO ESTIMATE AVAILABLE AT THIS TIME AS TO WHEN THIS COMMS OUTAGE WILL BE FIXED. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...LAHIFF SHORT TERM...SISSON LONG TERM...JN AVIATION...JN/LOCONTO EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
135 AM EDT SAT JUN 22 2013 .SYNOPSIS... HIGH PRESSURE ANCHORED OFF THE ATLANTIC COAST WILL KEEP THE NORTH COUNTRY DRY TODAY WITH PARTLY TO MOSTLY SUNNY SKIES THIS AFTERNOON AND TEMPERATURES IN THE MID 70S TO LOWER 80S. A WARM FRONT WILL MOVE SLOWLY THROUGH THE AREA ON SATURDAY WITH SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM WITH TEMPERATURES AGAIN RANGING THROUGH THE 70S NORTHEAST TO THE LOWER 80S SOUTHWEST. EVEN WARMER AND MORE HUMID CONDITIONS ARE EXPECTED SUNDAY INTO NEXT WEEK...WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND EVENING HOURS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1250 AM EDT SATURDAY...INHERITED FORECAST IN GOOD SHAPE WITH ONLY UPDATE NEEDED TO INCREASE SKY COVER AS CONVECTIVE DEBRIS CLOUDS ARE FILLING INTO THE REGION. WITH INCREASED CLOUD COVER TEMPS SHOULD HOLD FAIRLY STEADY FOR THE REMAINDER OF THE NIGHT IN THE 50S. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/... AS OF 323 PM EDT FRIDAY...SATURDAY...MODERATE CONFIDENCE CONTINUES THAT WE`LL SEE SOME SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM AS THE DECAYING MCV AND SHORT WAVE TROF MOVES ACROSS THE REGION DURING MIDDAY INTO THE EARLY EVENING. MODEL GUIDANCE HAS BEEN STRUGGLING WITH THE PLACEMENT OF THIS FEATURE WITH THE GFS MORE WIDESPREAD AND FURTHER SOUTH AND THE NAM FURTHER NORTH. HAVE PLAYED IT MORE TOWARD THE GFS/MAV SOLUTION AS RAP ANALYSIS SHOWS SIGNIFICANT MCV HAS FORMED. SO HIGHER POPS THAN WHAT THE NAM MOS SUGGESTS AND SLIGHT COOLER TEMPERATURES. HAVE STAYED MAINLY NEAR 80 WITH COOLER TEMPS NORTHEAST AND WARMER SOUTHWEST. WHERE CLOUDS/SHOWERS HANG ON IT COULD BE 5 DEGREES COOLER AND WHERE THEY DISSIPATE 5 DEGREES WARMER. IN THE ABSENCE OF ANY LARGE SCALE FORCING...ANY CONVECTIVE ACTIVITY WILL DISSIPATE GOING INTO THE EVENING AND OVERNIGHT HOURS SAT NIGHT WITH LOWS MAINLY IN THE 60S. ON SUNDAY...MORE TYPICAL ISOLATED TO SCATTERED AIRMASS TYPE PULSE SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN ON SUNDAY MAINLY IN THE MID TO LATE AFTERNOON/EVENING WITH ACTIVITY SETTLING DOWN OVERNIGHT SUNDAY NIGHT. CAPE VALUES NOT ALL THAT IMPRESSIVE (BELOW 100 J/KG) WITH GFS SUGGESTING A CAPPING SUBSIDENCE INVERSION MAY BE IN PLACE SO KEPT A MINIMAL CHANCE POPS IN THE FORECAST. IT SHOULD BE CONSIDERABLY WARMER AND MORE HUMID AIR PUSHES IN AS THE WARM FRONT LIFTS NORTHEAST SUNDAY WITH HIGHS IN THE 80S. SUNDAY NIGHT SHOULD BE VERY MILD WITH READINGS IN THE 60S PERHAPS NEAR 70 AT BTV WITH WARM AND HUMID AIR FIRMLY ENTRENCHED. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 350 PM EDT FRIDAY...LARGE SCALE PATTERN WL CONTINUE TO SUPPORT MID/UPPER LVL RIDGE ACRS THE SE CONUS WITH FAST WESTERLY FLW ALOFT NEAR THE INTERNATIONAL BORDER THRU EARLY NEXT WEEK. BY MID TO LATE NEXT WEEK ALL GUIDANCE SUGGESTS A PATTERN CHANGE WITH DEVELOPMENT OF FULL LATITUDE TROF ACRS THE GREAT LAKES/EASTERN CONUS AND LARGE RIDGE OVER THE INTER-MOUNTAIN WEST. THIS WL RESULT IN MUCH ABOVE NORMAL TEMPS FOR MONDAY/TUESDAY WITH CHCS FOR AFTN/EVENING SHOWERS/STORMS...WITH A TREND TWD COOLER AND WETTER CONDITIONS BY LATE NEXT WEEK...AS TROF DEVELOPS AND SFC LOW PRES IMPACTS OUR FA. PROGGED 85H TEMPS NEAR 16C AND 925MB TEMPS BTWN 20-22C ON MONDAY/TUESDAY...SUPPORTS HIGHS WELL INTO THE 80S WITH EVEN A FEW LOWER 90S POSSIBLE IN THE WARMER VALLEY LOCATIONS. IN ADDITION...PROGGED SFC DWPTS ARE EXPECTED TO BE IN THE MID/UPPER 60S...CREATING VERY MUGGY CONDITIONS...ESPECIALLY ON MONDAY. THIS HEAT/HUMIDITY WL HELP TO PRODUCE SOME MODEST CAPE VALUES...COMBINED WITH EMBEDDED 5H VORTS WL HELP IN THE DEVELOPMENT OF AFTN/EVENING SHOWERS/STORMS. WL CONT TO MENTION CHC POPS ATTM...WITH MAIN FOCUS DURING THE PEAK HEATING HRS. ANY STORMS THAT DUE DEVELOP WL HAVE THE POTENTIAL TO PRODUCE LOCALIZED HEAVY DOWNPOURS WITH PW VALUES BTWN 1.50 AND 1.75". BETTER DYNAMICS AND MOISTURE ARRIVES BY LATE NEXT WK...AS MID/UPPER LVL TROF DEVELOPS OVER THE GREAT LAKES. STILL SOME UNCERTAINTY OF MAGNITUDE AND POSITION OF SYSTEM ALONG WITH AVAILABLE MOISTURE...THEREFORE WL MENTION CHC POPS ATTM...WITH TEMPS DROPPING BACK TO NEAR NORMAL. EXPECT ABOVE NORMAL LOW TEMPS THRU THE PERIOD...GIVEN AMOUNT OF BL MOISTURE AND POTENTIAL FOR CLOUDS/PRECIP...MAINLY IN THE U50S MTNS TO NEAR 70F CPV/SLV. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... THROUGH 06Z SUNDAY...VFR COND THRU MUCH OF FORECAST PERIOD. EXPECTING MID CLD COVER AROUND BKN100-150 TO TRANSLATE DOWN TO BKN035-080 THIS AFTNOON AS WX SYSTEM APPROACHES. MSS/SLK WILL SEE MVFR COND WITH CEILINGS DOWN NEAR BKN030 AND -RW DRIVING DOWN TO 5-6SM AT TIMES BY 00Z SUN. AFT MIDDAY...VCSH/-SHRA POSSIBLE FOR ALL AREAS. WINDS GENERALLY RANGING FROM SE TO SW 5-10KTS. OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY... MAINLY VFR CONDITIONS WL PREVAIL THRU THE TIME PERIOD WITH THE EXCEPTION OF BRIEF MVFR/IFR IN THE HEAVIER SHOWERS/STORMS. BEST CHCS FOR STORMS WL BE DURING THE AFTERNOON AND EARLY EVENING HRS THRU TUESDAY. IN ADDITION...SOME PATCHY EARLY MORNING FOG/BR WITH MVFR/IFR WL BE POSSIBLE IF ANY TAF SITE RECIEVES HEAVY RAINFALL FROM CONVECTION DURING THE DAYTIME. EXPECT MAINLY SOUTHERLY WINDS THRU THE PERIOD. && .EQUIPMENT... OBSERVATIONS FROM RUTLAND-SOUTHERN VERMONT REGIONAL AIRPORT (KRUT) REMAIN UNAVAILABLE DUE TO A TELEPHONE COMMS LINE ISSUE. THE FAA AOCC IS AWARE OF THE ISSUE...BUT THERE IS NO ESTIMATE AVAILABLE AT THIS TIME AS TO WHEN THIS COMMS OUTAGE WILL BE FIXED. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...LAHIFF SHORT TERM...SISSON LONG TERM...TABER AVIATION...JN/LOCONTO EQUIPMENT...BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1252 AM EDT SAT JUN 22 2013 .SYNOPSIS... HIGH PRESSURE ANCHORED OFF THE ATLANTIC COAST WILL KEEP THE NORTH COUNTRY DRY TODAY WITH PARTLY TO MOSTLY SUNNY SKIES THIS AFTERNOON AND TEMPERATURES IN THE MID 70S TO LOWER 80S. A WARM FRONT WILL MOVE SLOWLY THROUGH THE AREA ON SATURDAY WITH SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM WITH TEMPERATURES AGAIN RANGING THROUGH THE 70S NORTHEAST TO THE LOWER 80S SOUTHWEST. EVEN WARMER AND MORE HUMID CONDITIONS ARE EXPECTED SUNDAY INTO NEXT WEEK...WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND EVENING HOURS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1250 AM EDT SATURDAY...INHERITED FORECAST IN GOOD SHAPE WITH ONLY UPDATE NEEDED TO INCREASE SKY COVER AS CONVECTIVE DEBRIS CLOUDS ARE FILLING INTO THE REGION. WITH INCREASED CLOUD COVER TEMPS SHOULD HOLD FAIRLY STEADY FOR THE REMAINDER OF THE NIGHT IN THE 50S. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/... AS OF 323 PM EDT FRIDAY...SATURDAY...MODERATE CONFIDENCE CONTINUES THAT WE`LL SEE SOME SOME SHOWERS AND A SLIGHT CHANCE OF A THUNDERSTORM AS THE DECAYING MCV AND SHORT WAVE TROF MOVES ACROSS THE REGION DURING MIDDAY INTO THE EARLY EVENING. MODEL GUIDANCE HAS BEEN STRUGGLING WITH THE PLACEMENT OF THIS FEATURE WITH THE GFS MORE WIDESPREAD AND FURTHER SOUTH AND THE NAM FURTHER NORTH. HAVE PLAYED IT MORE TOWARD THE GFS/MAV SOLUTION AS RAP ANALYSIS SHOWS SIGNIFICANT MCV HAS FORMED. SO HIGHER POPS THAN WHAT THE NAM MOS SUGGESTS AND SLIGHT COOLER TEMPERATURES. HAVE STAYED MAINLY NEAR 80 WITH COOLER TEMPS NORTHEAST AND WARMER SOUTHWEST. WHERE CLOUDS/SHOWERS HANG ON IT COULD BE 5 DEGREES COOLER AND WHERE THEY DISSIPATE 5 DEGREES WARMER. IN THE ABSENCE OF ANY LARGE SCALE FORCING...ANY CONVECTIVE ACTIVITY WILL DISSIPATE GOING INTO THE EVENING AND OVERNIGHT HOURS SAT NIGHT WITH LOWS MAINLY IN THE 60S. ON SUNDAY...MORE TYPICAL ISOLATED TO SCATTERED AIRMASS TYPE PULSE SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN ON SUNDAY MAINLY IN THE MID TO LATE AFTERNOON/EVENING WITH ACTIVITY SETTLING DOWN OVERNIGHT SUNDAY NIGHT. CAPE VALUES NOT ALL THAT IMPRESSIVE (BELOW 100 J/KG) WITH GFS SUGGESTING A CAPPING SUBSIDENCE INVERSION MAY BE IN PLACE SO KEPT A MINIMAL CHANCE POPS IN THE FORECAST. IT SHOULD BE CONSIDERABLY WARMER AND MORE HUMID AIR PUSHES IN AS THE WARM FRONT LIFTS NORTHEAST SUNDAY WITH HIGHS IN THE 80S. SUNDAY NIGHT SHOULD BE VERY MILD WITH READINGS IN THE 60S PERHAPS NEAR 70 AT BTV WITH WARM AND HUMID AIR FIRMLY ENTRENCHED. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 350 PM EDT FRIDAY...LARGE SCALE PATTERN WL CONTINUE TO SUPPORT MID/UPPER LVL RIDGE ACRS THE SE CONUS WITH FAST WESTERLY FLW ALOFT NEAR THE INTERNATIONAL BORDER THRU EARLY NEXT WEEK. BY MID TO LATE NEXT WEEK ALL GUIDANCE SUGGESTS A PATTERN CHANGE WITH DEVELOPMENT OF FULL LATITUDE TROF ACRS THE GREAT LAKES/EASTERN CONUS AND LARGE RIDGE OVER THE INTER-MOUNTAIN WEST. THIS WL RESULT IN MUCH ABOVE NORMAL TEMPS FOR MONDAY/TUESDAY WITH CHCS FOR AFTN/EVENING SHOWERS/STORMS...WITH A TREND TWD COOLER AND WETTER CONDITIONS BY LATE NEXT WEEK...AS TROF DEVELOPS AND SFC LOW PRES IMPACTS OUR FA. PROGGED 85H TEMPS NEAR 16C AND 925MB TEMPS BTWN 20-22C ON MONDAY/TUESDAY...SUPPORTS HIGHS WELL INTO THE 80S WITH EVEN A FEW LOWER 90S POSSIBLE IN THE WARMER VALLEY LOCATIONS. IN ADDITION...PROGGED SFC DWPTS ARE EXPECTED TO BE IN THE MID/UPPER 60S...CREATING VERY MUGGY CONDITIONS...ESPECIALLY ON MONDAY. THIS HEAT/HUMIDITY WL HELP TO PRODUCE SOME MODEST CAPE VALUES...COMBINED WITH EMBEDDED 5H VORTS WL HELP IN THE DEVELOPMENT OF AFTN/EVENING SHOWERS/STORMS. WL CONT TO MENTION CHC POPS ATTM...WITH MAIN FOCUS DURING THE PEAK HEATING HRS. ANY STORMS THAT DUE DEVELOP WL HAVE THE POTENTIAL TO PRODUCE LOCALIZED HEAVY DOWNPOURS WITH PW VALUES BTWN 1.50 AND 1.75". BETTER DYNAMICS AND MOISTURE ARRIVES BY LATE NEXT WK...AS MID/UPPER LVL TROF DEVELOPS OVER THE GREAT LAKES. STILL SOME UNCERTAINTY OF MAGNITUDE AND POSITION OF SYSTEM ALONG WITH AVAILABLE MOISTURE...THEREFORE WL MENTION CHC POPS ATTM...WITH TEMPS DROPPING BACK TO NEAR NORMAL. EXPECT ABOVE NORMAL LOW TEMPS THRU THE PERIOD...GIVEN AMOUNT OF BL MOISTURE AND POTENTIAL FOR CLOUDS/PRECIP...MAINLY IN THE U50S MTNS TO NEAR 70F CPV/SLV. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... THROUGH 00Z SUNDAY...MAINLY VFR THROUGH THE OVERNIGHT HOURS THOUGH MID TO HIGH-LEVEL CLOUDINESS WILL BE ON THE INCREASE PARTICULARLY AFTER MIDNIGHT. WINDS WILL BE LIGHT AND VARIABLE UNDER BROAD SFC RIDGING. FOR SATURDAY...EXPECTING SHOWERS AND THUNDERSTORMS AND DEVELOPING SOUTHEASTWARD WITH TIME. EXACT TIMING ON THE ONSET OF PRECIPITATION IS DIFFICULT IT IS DEPENDENT ON WHAT EVOLVES WITH THE ONGOING CONVECTION ACROSS THE NORTHERN PLAINS/GREAT LAKES REGION TONIGHT. HOWEVER BASED ON PRESENT INDICATIONS THIS APPEARS TO BE IN THE 13-18Z TIMEFRAME. FOR NOW HAVE TREATED WITH VCSH DURING THAT PERIOD OF TIME. POTENTIAL FOR MVFR VISIBILITIES (BRIEF IFR VISIBILITIES POSSIBLE IN STEADIER/HEAVIER RAIN). WINDS WILL BE SOUTH/SOUTHWEST UNDER 10KTS...EXCEPT LIGHT/VARIABLE AT MSS. OUTLOOK 00Z SUNDAY THROUGH TUESDAY... MAINLY VFR CONDITIONS WL PREVAIL THRU THE TIME PERIOD WITH THE EXCEPTION OF BRIEF MVFR/IFR IN THE HEAVIER SHOWERS/STORMS. BEST CHCS FOR STORMS WL BE DURING THE AFTERNOON AND EARLY EVENING HRS THRU TUESDAY. IN ADDITION...SOME PATCHY EARLY MORNING FOG/BR WITH MVFR/IFR WL BE POSSIBLE IF ANY TAF SITE RECIEVES HEAVY RAINFALL FROM CONVECTION DURING THE DAYTIME. EXPECT MAINLY SOUTHERLY WINDS THRU THE PERIOD. && .EQUIPMENT... OBSERVATIONS FROM RUTLAND-SOUTHERN VERMONT REGIONAL AIRPORT (KRUT) REMAIN UNAVAILABLE DUE TO A TELEPHONE COMMS LINE ISSUE. THE FAA AOCC IS AWARE OF THE ISSUE...BUT THERE IS NO ESTIMATE AVAILABLE AT THIS TIME AS TO WHEN THIS COMMS OUTAGE WILL BE FIXED. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...LAHIFF SHORT TERM...SISSON LONG TERM...TABER AVIATION...TABER/LOCONTO EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
145 AM EDT SAT JUN 22 2013 .SYNOPSIS... A SLOW-MOVING FRONT JUST OFFSHORE...WILL DRIFT WEST AND ONSHORE LATE TONIGHT AND SATURDAY...INCREASING THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS. TYPICAL SUMMERTIME WEATHER IS EXPECTED TO RETURN NEXT WEEK WITH BERMUDA HIGH PRESSURE...THE PIEDMONT TROUGH AND THE DAILY SEA BREEZE...BECOMING THE DOMINANT SURFACE FEATURES. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 1045 PM FRIDAY...AS WE MOVE FURTHER INTO THE PRE-DAWN SATURDAY HOURS...CONVECTION ALONG AND AHEAD OF THE COASTAL FRONT JUST OFFSHORE...WILL OVERSPREAD THE COASTAL AREAS OF THE ILM CWA. AS SEEN WITH LOCAL AND ADJACENT 88DS...THE CONVECTION FALLS APART THE FURTHER INLAND IT TRACKS DUE TO THE DRIER AIR MASS IT ENCOUNTERS. WITH TIME AND AFTER THIS PERIOD...THE AIRMASS OVER INLAND LOCATIONS WILL BECOME SATURATED AND PRIMED FOR EXTENDED CONVECTION. TIMING ISSUES CONTINUE FOR THE SPREADING INLAND OF THE 50-70 POPS OVERNIGHT INTO SATURDAY. LATEST SREF PROBS FOR MEASURE-ABLE PCPN ILLUSTRATES DRAMATICALLY INCREASING POPS TOWARD DAYBREAK ACROSS THE MAJORITY OF THE ILM CWA. MIN TEMP GUIDANCE EARLIER TWEAKED WILL REMAIN AS IS. THE KLTX VWP AND 00Z SOUNDINGS FROM CHS AND MHX INDICATE AN ONSHORE FLOW SFC THRU AT LEAST 20K FEET...INDICATIVE OF A SUBTROPICAL/TROPICAL AIR MASS BEING ADVECTED ACROSS THE FA. 00Z PWS HAVE ALSO INCREASED...UP TO 1.87 INCHES AT MHX AND 1.68 INCHES AT CHS. PWS WILL LIKELY FURTHER RISE OVERNIGHT...AND THUS WILL CONTINUE TO HIGHLIGHT PONDING OF WATER POSSIBLE FROM HEAVY DOWNPOURS TONIGHT INTO SATURDAY IN THE HWO. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...THE MAIN FORECAST CHALLENGE WILL BE CENTERED AROUND POPS MAINLY FOR SATURDAY AS A SEEMINGLY EVER PRESENT FRONT FINALLY MAKES A MOVE INLAND. I HAVE TRENDED TOWARD THE MORE AGGRESSIVE MET/NAM GUIDANCE FOR POPS WHICH WARRANT AN INCREASE FOR SATURDAY`S VALUES. THIS CALLS FOR AN INCREASE IN CLOUD COVER AS WELL WHILE LEANING TOWARD THE LOWER NUMBERS ALONG THE COAST FOR HIGHS. AS FOR SATURDAY NIGHT AND SUNDAY THE FRONT WILL BECOME ABSORBED INTO THE SOUTHERLY SYNOPTIC FLOW AND POPS WILL BE ADDRESSED ON A MORE TYPICAL FASHION OF HIGHER VALUES BEING IN THE AFTERNOON AND EARLY EVENING HOURS. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 3 PM FRIDAY...UPPER LEVEL HIGH PRESSURE JUST OFF THE CAROLINA COAST MONDAY AND TUESDAY. THERE MAY BE A WEAKNESS ON ITS WESTERN PERIPHERY DUE TO LEFTOVER REMNANTS OF THE UPPER LOW OVER THE WRN PART OF THE CAROLINAS CURRENTLY. AT THE SURFACE HIGH PRESSURE TO COVER A BROAD EXPANSE OF THE WEST ATLANTIC. THE ORIENTATION OF THE HIGH WILL BE WEST TO EAST ELONGATED...WHICH IS NOT OPTIMAL FOR MOISTURE ADVECTION INTO THE REGION. EVEN SO A FAIRLY SEASONABLE AND DIURNAL COVERAGE OF CONVECTION SEEMS LIKELY. WED AND THURS TRANSITIONAL DAYS ALOFT WITH RIDGING BECOMING BROAD ACROSS THE NATIONS MIDSECTION EARLY ON FOLLOWED BY LARGE INCREASE IN AMPLITUDE OVER WRN STATES ON THURSDAY. THE TROUGHINESS DOWNSTREAM OVER THE EAST WILL BE CLOSED OFF QUICKLY PREVENTING MUCH AMPLITUDE INCREASE/LOCAL EFFECTS. INSTEAD A BROAD AND WEAK NORTHWESTERLY FLOW DEVELOPS. SURFACE PIEDMONT TROUGHINESS DEVELOPS AS WELL. IN THE END THE FORMER MAY ACT TO SLIGHTLY INHIBIT CONVECTION WHILE THE LATTER TRIES TO INCREASE IT. END RESULT MAY MEAN LITTLE SIGNIFICANT CHANGES IN RAIN CHANCES THROUGH MOST OF THE PERIOD. ON FRIDAY TROUGHINESS APPEARS TO INCREASE IN AMPLITUDE OVER THE EASTERN U.S. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...PERIODS OF MVFR/IFR EXPECTED DUE TO ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS...PERIODS OF LOWERED CIGS AND PATCHY FOG THROUGH THE VALID PERIOD. OTHERWISE VFR. TRICKY FORECAST CONTINUES FOR THE TAF PERIOD AS A NEARLY STALLED FRONT OFFSHORE CONTINUES TO SLOWLY MOVE WEST TOWARD THE AREA. LATEST RADAR IMAGERY DEPICTS SHOWERS AFFECTING MAINLY THE COASTAL SITES. ANTICIPATE TREND WILL CONTINUE THROUGH THE VALID PERIOD... WITH HEAVIER RAINFALL EXPECTED TO PUSH TO THE INLAND SITES BY THE MORNING HOURS. PERIODS OF HEAVY RAINFALL...ALONG WITH INTERMITTENT PERIODS OF LOWERED CIGS...ARE EXPECTED TO REDUCE CONDITIONS TO MVFR/IFR THROUGHOUT THE VALID PERIOD. THUNDERSTORM CHANCES WILL INCREASE ON SATURDAY AS WELL...THOUGH GIVEN UNCERTAINTY HAVE OPTED TO KEEP VCTS ATTM. AS FOR WINDS...NORTHEAST WINDS 5 TO 8 KTS THROUGH LATE MORNING ON SATURDAY WILL GRADUALLY BECOME EAST-SOUTHEAST ALONG THE COAST BY AFTERNOON WITH SUSTAINED WINDS AOB 8 KTS. INTO THE EVENING HOURS...TSRA CHANCES WILL DIMINISH WITH ISOLATED TO SCATTERED SHOWERS CONTINUING AND LIGHT EAST-SOUTHEAST WINDS. EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHOWERS THROUGH WEDNESDAY AS A STALLED FRONT LINGERS NEAR THE COAST. BETTER CHANCE OF PRECIPITATION WILL BE IN THE AFTERNOON HOURS WITH LOCALIZED PERIODS OF MVFR/IFR POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM FRIDAY...THE APPROACH AND EVENTUAL PASSAGE OF THE COASTAL FRONT ONSHORE WILL GOVERN THE WINDS ACROSS THE ILM WATERS. LOOKING AT A NE-E WIND AHEAD OF THE FRONT...SE-S WIND AFTER ITS PASSAGE. SFC PG HAVING SOMEWHAT RELAXED AHEAD OF THE FRONT... RESULTING WITH WIND SPEEDS AROUND 10 KT. HRRR AND NAM INDICATE A TIGHTENING OF THE GRADIENT AFTER ITS PASSAGE...WITH WIND SPEEDS AROUND 15 KT...POSSIBLY WITH GUSTS UP TO 20 KT. SIGNIFICANT SEAS EARLY ON WILL INITIALLY DROP TO 2 TO 3 FT THRUOUT THE ILM WATERS...THEN INCREASE TO 3 TO 4 FT ALONG AND AFTER THE COASTAL FRONT PUSHES ONSHORE. THE NAM AND HRRR INDICATE THE FRONT TO PUSH ONSHORE FROM CAPE FEAR NORTH AROUND DAYBREAK...AND THE REMAINING WATERS SOUTH OF THE CAPE DURING DAYLIGHT SATURDAY. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...MAIN FORECAST CHALLENGE FOR THE MARINE COMMUNITY WILL OCCUR EARLY IN THE PERIOD AS A FRONT THAT HAS BEEN LINGERING OFF THE COAST MAKES A MOVE INLAND. WIND DIRECTION WILL BE A LOW CONFIDENCE EVENT FOR SATURDAY UNTIL THE SYNOPTIC SOUTHEASTERLY FLOW BECOMES THE DOMINANT FEATURE LATE SATURDAY. FOR NOW THE COASTAL AREAS WILL SEE A WEST TO NORTHWEST FLOW EARLY WITH A SOUTHEASTERLY FLOW ACROSS THE OUTER WATERS. ALL AREAS SHOULD SEE SOUTHEASTERLY WINDS LATE SATURDAY. FOR SUNDAY A TYPICAL SUMMERTIME PATTERN OF SOUTHERLY WINDS WILL PREVAIL. FOR THE MOST PART WIND SPEEDS WILL REMAIN MORE REPRESENTATIVE OF SUMMER WITH 10-15 KNOTS PROBABLY LEANING MORE TOWARD THE LOWER END OF THE RANGE. WAVEWATCH SEAS REMAIN IN A 2-4 FOOT RANGE THROUGH THE PERIOD. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 3 PM FRIDAY...HIGH PRESSURE ACROSS THE WEST ALTAIC THE ENTIRE TIME. THIS HIGH WILL EXTEND A RIDGE AXIS INTO THE CAROLINAS THROUGH THE PERIOD THAT MAY VACILLATE IN BOTH STRENGTH AND LOCATION AT TIMES. END RESULT WILL BE SMALL VARIATIONS IN WIND DIRECTION BETWEEN SOUTH AND SOUTHWEST. WIND SPEED WILL SHOW LITTLE ENOUGH CHANGE THAT A FORECAST OF ABOUT 10 KTS WILL HOLD FOR MOST OF THE TIME. WNA GUIDANCE SHOWS A MINOR EASTERLY SWELL COMBINING WITH THE WIND WAVES ON TUESDAY. OVERALL SEAS FORECAST HOWEVER TO REMAIN FAIRLY UNCHANGING AT A GENERAL 2 TO 4 FT...HIGHEST OFFSHORE. && .TIDES/COASTAL FLOODING... AS OF 11 PM FRIDAY...HIGH TIDE AND ASSOCIATED HIGHEST GAGE READINGS HAVE COME AND BY NOW ACROSS THE BEACHES AND NOW ACROSS ALONG THE CAPE FEAR RIVER. MYRTLE BEACH SPRINGMAID PIER ECLIPSED 7.05 FT MLLW...WRIGHTSVILLE BEACH JOHNNY MERCER PIER AT 5.7 FT MLLW...AND THE WILMINGTON GAGE IN THE CAPE FEAR RIVER AROUND 5.8 FT MLLW. THE NEXT HIGH TIDE CYCLES SUSCEPTIBLE TO MINOR COASTAL FLOODING WILL OCCUR ON SATURDAY...SUNDAY AND MONDAY DURING THE MID TO LATE EVENING HOURS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...SHK LONG TERM...MBB AVIATION...SGL/RJD TIDES/COASTAL FLOODING...DCH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
953 PM CDT SUN JUN 23 2013 .UPDATE... ISSUED AT 952 PM CDT SUN JUN 23 2013 WANING CONVECTION OVER NORTHERN FOSTER COUNTY SHOULD QUICKLY DIMINISH IN THE NEXT HOUR. WILL KEEP A CHANCE POP HERE FOR THE NEXT HOUR. OTHERWISE...ISOLATED SHOWERS FROM SOUTHERN SASKATCHEWAN INTO NORTHWEST NORTH DAKOTA CONTINUE TO QUICKLY DIMINISH. WILL NOT MENTION POPS HERE TONIGHT. OTHERWISE...CURRENT FORECAST IS IN GOOD SHAPE. DID ADJUST CLOUD COVER LOWER FOR MOST AREAS THIS EVENING AND WAS A LITTLE SLOWER TO INCREASE CLOUD COVER AFTER MIDNIGHT IN THE WEST. LATEST 01Z HRRR IS BRINGING SOME LIGHT QPF INTO THE FAR SOUTHWEST BETWEEN 11Z-12Z MONDAY...SO WILL KEEP A SLIGHT CHANCE OF CONVECTION IN THE FAR SOUTHWEST TOWARD MORNING. UPDATE ISSUED AT 703 PM CDT SUN JUN 23 2013 MAIN ISSUE WITH THE EARLY EVENING UPDATE IS CURRENT SHOWER AND THUNDERSTORM ACTIVITY. CURRENTLY SHOWER AND THUNDERSTORMS WERE LOCATED FROM JUST NORTH OF GARRISON...TO MINOT...AND THEN NORTHEAST TO ROLETTE COUNTY. WITH A FEW STRAY SHOWERS EXTENDING BACK TO NEAR CROSBY. ACTIVITY HAS SHOWN A DECREASE IN INTENSITY IN THE PAST TWO HOURS. HAVE ADJUSTED POPS A BIT LOWER AND DECREASED AREAL COVERAGE. EXPECT ACTIVITY TO CONTINUE TO DECREASE OVER THE NEXT FEW HOURS...AND DISSIPATE COMPLETELY BY AROUND 10 PM. OTHERWISE NO SIGNIFICANT CHANGES TO THE CURRENT FORECAST. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 345 PM CDT SUN JUN 23 2013 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE SCATTERED STRONG THUNDERSTORMS NORTH THIS AFTERNOON/EARLY EVENING...FOLLOWED BY ANOTHER CHANCE OF POSSIBLY STRONG TO SEVERE STORMS MONDAY AFTERNOON. CURRENTLY...UPPER LOW OVER CENTRAL SASKATCHEWAN WITH A STRONG EMBEDDED IMPULSE ROTATING NORTHEAST THROUGH THE DEVILS LAKE BASIN INTO NORTHEAST NORTH DAKOTA. STEEP LAPSE RATES WITH COLD AIR ALOFT HAS TRIGGERED A FEW STRONGER STORMS NEAR THE INTERNATIONAL BORDER. A FEW STRONGER STORMS ARE POSSIBLE AND PERHAPS PULSE SEVERE WITH MUCAPE 1-2K J/KG. LACK OF SUPPORTIVE 0-6KM SHEAR WILL LIMIT UPDRAFT LONGEVITY. STORMS ARE DIURNAL IN NATURE AND SHOULD QUICKLY DISSIPATE INTO EARLY THIS EVENING AS THE NOCTURNAL INVERSION DEVELOPS. BEFORE THIS HAPPENS...WILL NEED TO MONITOR FOR POSSIBLE FUNNELS/LAND SPOUTS WITH THE NON-SUPERCELL TOR PARAMETER ELEVATED OVER NORTHWEST NORTH DAKOTA. MOSTLY CLEAR THE REMAINDER OF THIS EVENING IN THE WAKE OF THE CURRENT CONVECTION. MODELS DEVELOP A LOW LEVEL JET LATER THIS EVENING INTO THE OVERNIGHT ACROSS WESTERN SOUTH DAKOTA NOSING INTO SOUTHWEST NORTH DAKOTA LATE AROUND OR AFTER 09Z. WILL INTRODUCE SLIGHT CHANCES FOR THUNDER FAR SOUTHWEST 9-12Z GIVEN THIS FORCING ALONG WITH INCREASING BOUNDARY LAYER MOISTURE. KEPT SLIGHT CHANCE POPS GOING THROUGH THE MORNING HOURS WEST. BOUNDARY LAYER MOISTURE CONTINUES TO ADVECT INTO THE REGION THROUGHOUT THE DAY MONDAY THANKS TO STRONG MID LEVEL FLOW/MOISTURE FETCH FROM THE SOUTHERN PLAINS INTO THE DAKOTAS WITH SFC DEWPOINT TEMPS RISING INTO THE 60S AREA WIDE. THIS WILL CONTRIBUTE TO INCREASING INSTABILITY WITH MUCAPES PROJECTED TO INCREASING TO AROUND 2500 J/KG IN THE AFTERNOON AS SFC TEMPS WARM INTO THE LOW/MID 80S. WHILE A CAPPING INVERSION LOOKS TO BE IN PLACE...A POTENTIAL TRIGGER VIA A LEAD SHORT WAVE IMPULSE IS FORECAST TO APPROACH THE DAKOTAS MONDAY AFTERNOON LEADING TO CONVECTIVE INITIALIZATION. WILL MAINTAIN POPS AS IS FOR NOW DUE TO THE UNCERTAINTY DURING THE AFTERNOON WHERE AND IF STORMS WILL DEVELOP. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 345 PM CDT SUN JUN 23 2013 POTENTIAL FOR SEVERE THUNDERSTORMS CONTINUE MONDAY NIGHT AND TUESDAY. SOUTHWEST FLOW ALOFT TRANSITIONS TO A WESTERLY FLOW WEDNESDAY...THEN NORTHWEST AS RIDGING DEVELOPS OVER THE FOUR CORNERS. HOWEVER THE RIDGE FLATTENS SATURDAY AS A SHORTWAVE ROLLS THROUGH. THIS SHOULD BE TEMPORARY AS THE LONG TERM MODEL SUITE THEN SHOWS A STRONGER AMPLIFICATION OF THE RIDGE TO COMMENCE ACROSS THE INTERMOUNTAIN WEST JUST BEYOND THIS EXTENDED PERIOD. FOR MONDAY NIGHT...WITH STRONG WARM/MOIST AIR ADVECTION IN THE LOWER LEVELS COMBINED WITH A COUPLE OF SHORTWAVES TRANSVERSING THROUGH VIA A SOUTHWEST FLOW ALOFT...THIS SHOULD BE ENOUGH TO PROMOTE CONVECTION THROUGH THE NIGHT. SURFACE DEWPOINTS IN THE UPPER 60S TO AROUND 70 WILL YIELD MUGGY CONDITIONS AND VERY WARM OVERNIGHT LOWS MONDAY NIGHT. THE STRONGEST SHORTWAVE SHIFTS THROUGH ON TUESDAY AS A SURFACE COLD FRONT MOVES FROM WEST TO EAST. EXPECTING THUNDERSTORMS LIKELY ALONG AND AHEAD OF THE FRONT. THE SCENARIO THAT APPEARS MOST LIKELY IS THUNDERSTORMS WILL BE ONGOING FROM MONDAY NIGHT AND CONTINUE FOR MOST OF TUESDAY INTO TUESDAY EVENING. THE COLD FRONT SHOULD CLEAR THE JAMES RIVER VALLEY BY 06Z WEDNESDAY. WEDNESDAY LOOKS MOSTLY DRY WITH THE EXCEPTION OF NORTH CENTRAL NORTH DAKOTA WHERE A SHORTWAVE WILL MOVE THROUGH PRODUCING A SLIGHT CHC OF SHOWERS/THUNDERSTORMS. RIDGING WEST OF NORTH DAKOTA AS MENTIONED ABOVE WILL PROMOTE DRY WEATHER FOR THURSDAY/FRIDAY...THEN A CHANCE FOR THUNDERSTORMS SATURDAY THROUGH SUNDAY WITH A SHORTWAVE MOVING THROUGH. WARMEST HIGH TEMPERATURES WILL BE TUESDAY WITH MID TO UPPER 80S ALONG WITH HUMID CONDITIONS. DRIER AIR/LOWER DEWPOINTS CAN BE EXPECTED FOR THE REST OF THE WEEK WITH HIGHS COOLING TO THE UPPER 70S NORTH AND LOWER 80S SOUTH THURSDAY THROUGH SATURDAY. OVERNIGHT LOWS IN THE 60S TO NEAR 70 TUESDAY MORNING...THEN UPPER 50S FOR THE REST OF THE LONG TERM PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 952 PM CDT SUN JUN 23 2013 VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES THROUGH THE FORECAST PERIOD. MAINLY CLEAR SKIES TONIGHT AND INCREASING MID AND HIGH LEVEL CLOUDINESS ON MONDAY. LIGHT SOUTHWEST WINDS THIS EVENING WILL SHIFT SOUTH...THEN INCREASE OUT OF THE SOUTHEAST ON MONDAY. CONVECTION POSSIBLE IN THE WEST MONDAY 18Z-00Z BUT WILL HOLD OFF ON BRINGING IT TO ANY SINGLE TAF SITE AT THIS TIME. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...NH LONG TERM...KS AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
935 PM CDT SUN JUN 23 2013 .UPDATE... ISSUED AT 934 PM CDT SUN JUN 23 2013 THE LAST OF THE SHOWERS DISSIPATING NOW MOVING INTO THE LANGDON- DEVILS LAKE TO NEW ROCKORD AREAS. RE-DID THE POP GRIDDS TO ACCOUNT FOR CURRENT AREA AND REMOVED ANY POPS FROM NW MN. NO OTHER CHANGES. UPDATE ISSUED AT 628 PM CDT SUN JUN 23 2013 WATER VAPOR SHOWS SMALL IMPULSE MOVING INTO FAR SW MANITOBA FROM SE SASK ATTM....THIS LEADING TO THE BIT MORE COVERAGE OF SHRA/TSRA IN THAT REGION. SOME OF THIS WILL MOVE INTO DVL REGION AND ALONG THE NRN BORDER REGION NEXT 1-3 HOURS BEFORE DARK. EXPECT ACTIVITY TO WEAKEN AND DIMINISH BY 04-05Z AND UPDATED HOURLY POP GRIDDS TO ACCOUNT FOR THAT. OTHERWISE NOTHING ELSE GOING ON IN MINNESOTA SO TRIMMED POPS THERE TO ONLY THE FAR NORTH. WINDS WILL DIMINISH BY 02Z AND CU WILL CONTINUE TO DIMINISH LEADING TO A CLEAR SKY IN MOST AREAS OVERNIGHT. LOWS LOOKED REASONABLE. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 313 PM CDT SUN JUN 23 2013 CONVECTION CHANCES CONTINUE TO BE THE PRIMARY FORECAST PROBLEM FOR THE PERIOD. WV LOOP SHOWS THE MAIN SHORTWAVE IS CURRENTLY IN THE PROCESS OF LIFTING THROUGH THE CWA ON ITS WAY INTO CANADA. THE MAIN SFC LOW IS ALREADY IN SOUTHERN MANITOBA...WITH ALL BUT THE FAR NORTHEASTERN CWA SEEING WESTERLY WINDS ON THE SOUTH SIDE OF THE LOW. THE RAIN BAND FROM THIS MORNING HAS LIFTING NORTH INTO CANADA...AND SOME CLEARING HAS BEEN GOING ON ALTHOUGH WITH PRETTY LOW CONVECTIVE TEMPS CU HAS REDEVELOPED RAPIDLY. THERE HAS BEEN A DECREASE IN MOISTURE AS THE WEST WINDS BRING IN DRIER AIR...BUT THERE IS STILL A DECENT AMOUNT OF HUMIDITY AND WITH SOME CLEARING CAPE HAS REACHED AROUND 1000 J/KG ACROSS THE CENTRAL CWA. WHILE THE BEST LIFT WILL BE QUICKLY MOVING OFF TO THE NORTH THIS EVENING...THERE IS ENOUGH INSTABILITY HANGING AROUND THAT CANNOT COMPLETELY RULE OUT THUNDERSTORM REDEVELOPMENT...AND THE RAP AND HRRR SHOW SIGNS OF THIS ALTHOUGH STRENGTH DOES NOT SEEM IMPRESSIVE AT THIS POINT. WILL KEEP SOME 30-60 POPS GOING MAINLY NORTH OF THE HIGHWAY 2 CORRIDOR THROUGH EARLY EVENING BEFORE WE GO DRY AFTER MIDNIGHT. MONDAY SHOULD BE FAIRLY QUIET WITH WEAK UPPER RIDGING BETWEEN SYSTEMS. WINDS WILL SHIFT BACK TO THE SOUTH AS A SFC TROUGH BEGINS TO DEEPEN OVER THE ROCKIES/WESTERN PLAINS. 850MB TEMPS CLIMB BACK UP TOWARDS THE UPPER TEENS C AND WITH PLENTY OF SUN WE SHOULD BE ABLE TO CLIMB INTO THE MID 80S ACROSS MOST OF THE AREA. THE QUIET CONDITIONS WILL BE SHORT LIVED AS MODELS SHOW SOME INDICATION OF A WEAK SHORTWAVE MOVING IN MONDAY NIGHT. THINK THERE COULD BE SOME STORMS MOVING IN FROM THE WEST MONDAY NIGHT...WITH THE MODELS SHOWING SOME ELEVATED INSTABILITY LIFTING INTO THE CWA OVERNIGHT. KEPT SOME POPS AROUND 30 PERCENT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 313 PM CDT SUN JUN 23 2013 THINK THAT THE BETTER CHANCES FOR MORE SIGNIFICANT STORMS WILL BE TUESDAY WHEN A FAIRLY STRONG SHORTWAVE TROUGH MOVES INTO THE DAKOTAS. THE SFC TROUGH AXIS WILL MOVE INTO CENTRAL ND...WITH SOUTHEASTERLY WINDS AHEAD OF IT AND GOOD LOW LEVEL CONVERGENCE. INSTABILITY WILL DEPEND ON EXACTLY ANYTHING OVERNIGHT EVOLVES...BUT THERE IS THE POSSIBILITY OF MORE THAN 2000 J/KG OF CAPE. CONTINUED TO KEEP FAIRLY HIGH POPS FOR THUNDERSTORMS TUESDAY INTO TUESDAY NIGHT...BUT IS A BIT EARLY FOR ANY SEVERE MENTION AT THIS TIME. SOME PRECIP MAY LINGER INTO WEDNESDAY MORNING...BUT OVERALL THERE SHOULD BE A DRYING TREND AS THE UPPER SHORTWAVE PULLS OFF TOWARDS THE GREAT LAKES. TEMPS SHOULD BE FAIRLY SEASONABLE IN THE LOW 80S. WEDNESDAY NIGHT TO SATURDAY NIGHT...MODELS IN GOOD AGREEMENT WITH RETROGRADING AND AMPLIFYING WESTERN CONUS RIDGE AND GREAT LAKES TROUGH AT 500MB. AS A RESULT NW FLOW ACROSS THE NORTHERN PLAINS WILL DEVELOP. THIS WILL MAKE FOR SEASONAL END OF JUNE TEMPERATURES AND NEARLY CLIMO POPS AS THE TIMING OF ANY WEAK SHORT WAVES FEATURE WILL NEED TO COINCIDE WITH PEAK HEATING TO INITIATE ANY DIURNALLY DRIVEN CONVECTION AND OVERALL COVERAGE IS EXPECTED TO BE LOW...THUS THE LOW POPS IN THE EXTENDED. .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1252 PM CDT SUN JUN 23 2013 LOW PRESSURE TRACKING ALMOST DUE NORTH ALONG RED RIVER NEAR HCO WITH TROUGH AND EDGE OF RAIN NOW THRU TVF. EXPECT MVFR CIGS TO CONTINUE TO IMPROVE WITH DRIER AIR MIXING IN ON WESTERLY GUSTS 20 TO 30KTS...SOME ISOLATED SHOWERS THIS AFTERNOON POSSIBLE...WITH VFR CONDITIONS EXPECTED THIS EVENING AND OVERNIGHT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1252 PM CDT SUN JUN 23 2013 LOW PRESSURE TRACKING ALMOST DUE NORTH ALONG RED RIVER NEAR HCO WITH TROUGH AND EDGE OF RAIN NOW THRU TVF. EXPECT MVFR CIGS TO CONTINUE TO IMPROVE WITH DRIER AIR MIXING IN ON WESTERLY GUSTS 20 TO 30KTS...SOME ISOLATED SHOWERS THIS AFTERNOON POSSIBLE...WITH VFR CONDITIONS EXPECTED THIS EVENING AND OVERNIGHT. && .HYDROLOGY... ISSUED AT 628 PM CDT SUN JUN 23 2013 NEW WARNINGS WERE DONE FOR THE BUFFALO RIVER AT SABIN AND DILWORTH FOR MINOR FLOODING. NEW WARNINGS ACROSS THE SOUTHERN VALLEY AT HARWOOD...WEST FARGO... KINDRED...ABERCROMBIE WITH AN INCREASE OF FLOODING TO MODERATE NOW EXPECTED AT WAHPETON AND FARGO AS THE AREA RIVERS RESPOND TO LAST NIGHTS RAINFALL OF ONE TO TWO INCHES ON ALREADY SATURATED SOILS. ALSO...MAPLETON WARNING WAS CANCELLED AS THE RIVER FELL BELOW FLOOD STAGE EARLIER TODAY. .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...JR LONG TERM...JR/JK AVIATION...RIDDLE HYDROLOGY...WJB/JK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
123 AM CDT SAT JUN 22 2013 .UPDATE... ISSUED AT 122 AM CDT SAT JUN 22 2013 IN REGARDS TO CONVECTION THROUGH 12 UTC...WILL FOLLOW CLOSELY TO THE 04 UTC HRRR AND RAP WHICH CONTINUE TO REGENERATE CONVECTION ACROSS THE NORTHWEST AND NORTH CENTRAL IN THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET STREAK...WHICH MATCHES WELL WITH THE LATEST RADAR TRENDS. OTHERWISE...THERE IS A SLIGHT CHANCE OF THUNDERSTORMS ACROSS THE REMAINDER OF THE AREA AS THE AFOREMENTIONED JET STREAK PROPAGATES SOUTHEAST THROUGH THE NIGHT. DO BELIEVE THAT THE SEVERE THREAT IS QUICKLY DIMINISHING AS -10 TO -30 HAIL CAPE VALUES HAVE FALLEN BELOW 200 J/KG AND DOWNDRAFT CAPE VALUES BELOW 500 J/KG. UPDATE ISSUED AT 952 PM CDT FRI JUN 21 2013 CLOUDS AND CONVECTION FARTHER SOUTH APPEARED TO BE A LIMITING FACTOR FOR CONVECTION THIS EVENING. CURRENTLY THE NORTHWEST AND FAR NORTH CENTRAL APPEAR TO BE THE MAIN AREAS OF FOCUS LATE THIS EVENING ASSOCIATED WITH A WAVE LIFTING THROUGH NORTHEAST MONTANA. HAVE ADJUSTED POPS ACCORDINGLY WITH HIGHEST POPS IN THESE AREAS AND LOWER POPS ELSEWHERE. BUT WITH UNSTABLE AIRMASS REMAINING ALOFT CANNOT PULL POPS COMPLETELY. CLOUD COVER MAY LIMIT FOG DEVELOPMENT AS WELL...BUT WITH ABUNDANT MOISTURE AROUND AND NEAR ZERO TEMP/DEWPOINT SPREADS ALREADY...WILL KEEP AREAS OF FOG IN THE FORECAST ACROSS THE AREA TONIGHT INTO SATURDAY MORNING. NO CHANGES TO TEMPERATURES...OTHER THAN POPULATE WITH LATEST SIGNIFICANT WEATHER GRIDS. UPDATE ISSUED AT 721 PM CDT FRI JUN 21 2013 QUICK UPDATE FOR EVENING POPS. NORTH A LOT OF CONVECTION OVER WESTERN AND CENTRAL NORTH DAKOTA THIS EVENING. ONE AREA OF CONVECTION FIRED IN NORTHERN BURLEIGH COUNTY...BUT HAS RECENTLY DISSIPATED QUICKLY AS IT MOVED INTO A MORE STABLE ATMOSPHERE FROM WELLS COUNTY NORTHWARD. WILL TONE DOWN POPS THIS EVENING TO MAINLY SLIGHT CHANCE...EXCEPT ALONG THE FAR WEST WHERE CONVECTION HAS DEVELOPED OVER EASTERN MONTANA. FOR NOW WILL LEAVE POP CHANCES ALONE FOR THE OVERNIGHT PERIOD BUT WILL TAKE A CLOSER LOOK LATER THIS EVENING. DID HAVE SOME STRONG WINDS OVER THE FAR SOUTHEAST CWA DUE TO WAKE LOW FORMED FROM CONVECTION EARLIER OVER EASTERN SOUTH DAKOTA. WINDS HERE HAVE ALSO DIMINISHED. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 254 PM CDT FRI JUN 21 2013 FORECAST HIGHLIGHTS WILL BE POSSIBLE SEVERE CONVECTION AND HEAVY RAIN THROUGH SATURDAY. CURRENTLY...UPPER LEVEL TROUGH OVER THE WESTERN CONUS AND A RIDGE OVER THE MISSISSIPPI VALLEY RESULTS IN STRONG SOUTHWEST FLOW ALOFT ACROSS THE DAKOTAS. STRONGEST CONVECTION RIGHT NOW IS OVER SOUTH DAKOTA NEAR A STATIONARY FRONT/SFC TROUGH. EARLIER SEVERE STORMS OVER NORTH DAKOTA QUICKLY WEAKENED AFTER 18Z AS FORCING ALOFT DIMINISHED. ADDITIONAL ENERGY MOVING THROUGH THE REGION IN SOUTHWEST FLOW ALOFT STILL EXPECTED AND WILL MAINTAIN CURRENT THUNDERSTORM PROBABILITIES AS IS FOR NOW. BEST CHANCE FOR SEVERE WEATHER WILL CONTINUE TO BE FROM SOUTHWEST ND NORTHEAST INTO THE SOUTHERN DEVILS LAKE BASIN WHERE THE BEST 0-6KM WIND SHEAR AND INSTABILITY WILL BE CO LOCATED. STORMS WILL EVENTUALLY DISSIPATE SOUTH TO NORTH TONIGHT AS FORCING MOVES NORTH INTO CANADA. EXPECT REDEVELOPMENT OF LOW STRATUS AND FOG WEST AND CENTRAL TONIGHT. REDEVELOPMENT OF CONVECTION ON SATURDAY AS ADDITIONAL WAVES ADVECT THROUGH THE NORTHERN PLAINS. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 254 PM CDT FRI JUN 21 2013 UPPER TROUGH WILL TRAVERSE ACROSS NORTH DAKOTA SUNDAY WITH MORE SHOWERS AND THUNDERSTORMS. A BIT OF A BREAK SUNDAY NIGHT...BUT WITH A PROGRESSIVE SOUTHWEST FLOW PERSISTING INTO TUESDAY NIGHT...EXPECT A COUPLE MORE SHORTWAVES TO SHIFT THROUGH WITH ADDITIONAL CHANCES OF FOR SHOWERS/THUNDERSTORMS. WEDNESDAY THROUGH FRIDAY...STILL EXPECTING AN UPPER RIDGE TO DEVELOP OVER THE FOUR CORNERS DURING THE PERIOD WITH THE RIDGE AXIS AMPLIFYING INTO SOUTHERN CANADA. A COMPENSATORY NORTHWEST FLOW DEVELOPS INTO WESTERN AND CENTRAL NORTH DAKOTA THURSDAY AND FRIDAY. THERE COULD BE A COUPLE OF RIDGE TOPPERS SLIDING THROUGH RESULTING IN A CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY IN EAST CENTRAL NORTH DAKOTA...WITH THE WEST REMAINING MORE STABLE AND DRIER. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY EVENING) ISSUED AT 122 AM CDT SAT JUN 22 2013 MVFR TO IFR STRATUS AND FOG IS EXPECTED TO DEVELOP OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA TONIGHT AND CONTINUE THROUGH APPROXIMATELY 14-15 UTC SATURDAY. THE BEST CHANCES FOR THUNDERSTORMS ON SATURDAY WILL BE ACROSS WESTERN AND NORTH CENTRAL NORTH DAKOTA...INCLUDING KISN...KMOT AND KDIK WHERE THUNDERSTORMS MAY CONTINUE TO REGENERATE MUCH OF THE DAY. OTHERWISE...BELIEVE THE THREAT FOR STORMS WILL HOLD OFF UNTIL APPROXIMATELY 20-22 UTC FOR KBIS AND AFTER 05 UTC AT KJMS SATURDAY NIGHT. && .HYDROLOGY... ISSUED AT 254 PM CDT FRI JUN 21 2013 WILL MAINTAIN THE FLASH FLOOD WATCH AS IS WITH CONTINUED CHANCES FOR STRONG TO SEVERE THUNDERSTORMS NOW THROUGH SUNDAY...WITH ADDITIONAL HEAVY RAINFALL POSSIBLE FOR THOSE LOCATIONS THAT HAVE SEEN SIGNIFICANT RAINFALL AMOUNTS WEDNESDAY NIGHT AND THURSDAY EVENING ACROSS SOUTH CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY. SOILS HAVE LITTLE TO NO CAPACITY TO HOLD ADDITIONAL WATER...ENHANCING RUNOFF AND THE POTENTIAL TO AGGRAVATE THE ONGOING OVERLAND FLOODING ACROSS THE AREA. A COMPLEX OF THUNDERSTORMS WITH HEAVY RAINFALL IS POSSIBLE AGAIN SATURDAY NIGHT INTO SUNDAY. ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE WITH LOCALLY HIGHER AMOUNTS. && .BIS WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH SUNDAY EVENING FOR NDZ023-025-036-037- 046>048-050-051. && $$ UPDATE...AYD SHORT TERM...NH LONG TERM...KS AVIATION...TWH HYDROLOGY...NH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
933 PM CDT SUN JUN 23 2013 .UPDATE... ISSUED AT 930 PM CDT SUN JUN 23 2013 LOW LEVEL JET STARTING TO HELP GENERATE SHOWERS AND THUNDERSTORMS FROM SOUTHEAST NEBRASKA INTO SOUTHERN IOWA. THESE WILL LIKELY CONTINUE TO DEVELOP NORTHWARD THROUGH THE EVENING. ALTHOUGH THE LOW LEVEL JET ORIENTATION WOULD SUGGEST THAT THE BEST COVERAGE WILL REMAIN SOUTHEAST OF OUR CWA. THIS IS SUPPORTED BY THE LATEST HRRR. HOWEVER DID GO AHEAD AND ADD IN CHANCE POPS ACROSS OUR FAR SOUTH...AS CANNOT COMPLETELY RULE OUT A STORM MAKING IT UP THERE AFTER ABOUT 08Z. ATTENTION THEN TURNS TO A WAVE COMING OUT OF THE ROCKIES. CONVECTION ACROSS NORTHEAST COLORADO SHOULD MOVE EAST THROUGH NEBRASKA OVERNIGHT. LIFT AND MOISTURE TRANSPORT AHEAD OF THIS WAVE SHOULD ALLOW CONVECTION TO MAINTAIN ITSELF. PREFER THE FASTER TIMING OF THE HRRR AS COMPARED TO THE NEW SLOWER 4KM NAM. THIS WOULD BRING THE THREAT INTO OUR SOUTHWEST AROUND 12Z...PUSHING NORTHEAST THROUGH THE MORNING HOURS. THIS FITS PRETTY WELL WITH THE GOING FORECAST...SO DID NOT MAKE ANY CHANGES TO POPS TOMORROW. AS MENTIONED BELOW...SEVERE THREAT SHOULD BE LOW WITH THIS MORNING CONVECTION...ALTHOUGH MUCAPE APPROACHING 2000 J/KG MAY BE ENOUGH FOR A FEW MARGINAL HAIL PRODUCING STORMS. TIMING OF THIS WAVE IS STILL UNCERTAIN. IF IT ENDS UP SLOWER AND WE ARE ABLE TO GET MORE DAYTIME HEATING AHEAD OF IT...THE SEVERE POTENTIAL WOULD PROBABLY INCREASE. STILL TOUGH TO SAY WHAT HAPPENS TOMORROW NIGHT UNTIL WE SEE WHAT THE FIRST WAVE DOES. SEEMS LIKELY STORMS FIRE IN THE WESTERN PLAINS DURING THE AFTERNOON WITH A SECOND WAVE. WHETHER THESE SURVIVE INTO OUR CWA IS STILL UP IN THE AIR...WITH MOST CONVECTION ALLOWING MODELS SAYING NO...AND THE LOWER RESOLUTION NAM...GFS AND EC SUGGESTING YES. PROBABLY DEPENDENT ON EXTENT OF DRYING...SUBSIDENCE AND CAPPING BEHIND THE FIRST WAVE. WILL JUST HAVE TO CONTINUE TO MONITOR TRENDS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 341 PM CDT SUN JUN 23 2013 A FRONTAL BOUNDARY CONTINUES TO PUSH THROUGH THE EASTERN PORTION OF THE CWA THIS AFTERNOON AND IS EXPECTED TO EXIT THE AREA LATE THIS AFTERNOON. CONVECTION WHICH WE EARLIER THOUGHT MIGHT DEVELOP IN OUR SOUTHEAST LATE THIS AFTERNOON NOW LOOKS TO HOLD OFF UNTIL LATER IN THE EVENING...WHEN THE BOUNDARY IS OUT OF OUR AREA...SO DO NOT ANTICIPATE ANY DEVELOPMENT OVER OUR AREA. OTHERWISE...THE REMAINDER OF THE NIGHT SHOULD BE QUIET AS WEAK HIGH PRESSURE BUILDS INTO THE REGION. THIS WILL ALLOW FOR WINDS TO DIE OFF...AND CANNOT RULE OUT SOME PATCHY FOG DEVELOPMENT WITH RECENT RAINS...THOUGH DID NOT INCLUDE IN FORECAST AT THIS POINT WITH LOW CONFIDENCE. THE FORECAST BECOMES MORE CHALLENGING LATER TONIGHT INTO MONDAY...WITH MODELS DIFFERING ON THE TIMING AND STRENGTH OF ANOTHER SHORT WAVE LIFTING UP OVER THE AREA DURING THE DAY ON MONDAY. MONDAYS SHORT WAVE IS CURRENTLY VISIBLE ON THE WATER VAPOR IMAGERY NEAR LAS VEGAS NV. THE GFS/GEM/4KM NAM AND SREF OFFER THE WETTER SOLUTIONS AS THEY ARE STRONGER IN THE MID LEVELS...WHILE THE ECMWF AND NAM KEEP IT DRY DURING THE DAYTIME HOURS...ALTHOUGH THE NAM DOES SHOW SOME WEAK PV ON THE 1.5 SURFACE. ELECTED TO GO WITH THE WETTER SOLUTIONS WITH 850 MB THETA E ADVECTION INCREASING OVER THE AREA AS THE LOW LEVEL JET CRANKS UP OUT OF EASTERN NEBRASKA. IN ADDITION THERE WILL BE INSTABILITY AND SOME SHEAR...THOUGH IN THE ABSENCE OF CAPPING WOULD EXPECT NO REAL UPDRAFT ENERGY TO BE STORED UP. SO OTHER THAN SOME POSSIBLE SMALL HAIL WOULD NOT EXPECT SEVERE STORMS DURING THE DAY. THIS OF COURSE WILL IMPACT HIGH TEMPERATURES...SO WENT WITH COOLER GUIDANCES WITH HIGHS INTO THE LOWER 80S NORTHEAST TO THE UPPER 80S ALONG THE MISSOURI RIVER CORRIDOR. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 341 PM CDT SUN JUN 23 2013 MONDAY NIGHT IS THE MOST ACTIVE PERIOD IN THE LONGER TERM. ANOTHER STRONGER SHORT WAVE FOLLOWS MONDAY WAVE...WHICH WATER VAPOR SHOWS CURRENTLY OFF OF THE CA COAST. INTERESTINGLY...THE HI RES MODELS WHICH ARE SO ACTIVE ON MONDAY LEAVE MONDAY NIGHT DRY. HOWEVER THE NAM AND ECMWF ARE WET...ESPECIALLY ALONG AND NORTH OF I 90. THE ECMWF HAS BEEN VERY CONSISTENT WITH THIS FEATURE FOR 4 OR 5 DAYS NOW. SO IT IS VERY HARD TO IGNORE. THE NAM IS STRONG WITH THE PV 1.5...AND ABUNDANT INSTABILITY AND WIND SHEAR CONTINUES. MOST OF THE RAINFALL WILL OCCUR IN THE EVENING HOURS...AGAIN WITH THE HIGHEST CHANCES FOR HEAVIER RAINFALL ALONG AND NORTH OF I 90. NAM PWATS IN THOSE AREAS AVERAGE 1.5 TO 2.0 INCHES AND SOME SEVERE WEATHER IS POSSIBLE GIVEN THE INSTABILITY PARAMETERS. THE WAVE QUICKLY EXITS AFTER MIDNIGHT...WHICH WILL LEAVE TUESDAY DRY AND VERY WARM AND HUMID. UPPER RIDGING THEN BUILDS AS ADVERTISED AND RETROGRADES WESTWARD BY LATE WEEK AND NEXT WEEKEND. A SURFACE BOUNDARY MOVES THROUGH OUR AREA LATE TUESDAY NIGHT SHIFTING OUR WINDS TO THE NORTHWEST FOR WEDNESDAY. WITH BETTER MIXING...TEMPERATURES WILL STILL BE QUITE WARM...WITH LESS HUMID CONDITIONS WEST OF I 29. AS THE UPPER RIDGE RETROGRADES TO THE WEST CREATING A HIGHLY AMPLIFIED PATTERN... IT STILL LOOKS AS THOUGH TEMPERATURES WILL START A COOLING TREND ON THURSDAY...LASTING THROUGH THE WEEKEND. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 630 PM CDT SUN JUN 23 2013 CONVECTIVE CURIOSITIES AGAIN PART OF THE FORECAST PROCESS FOR 00Z TAF COLLECTIVE. ONE WAVE WHICH RECENTLY PUSHED PAST THE FOUR CORNERS WILL MOVE INTO THE AREA MONDAY MORNING. GIVEN THE LOW LEVEL JET...AND APPARENT BOUNDARY ACROSS SOUTHEAST NEBRASKA...EXPECT A FEW STORMS TO DEVELOP ALONG WARM ADVECTIVE WING AND IMPACT KSUX AREA AFTER 09Z...AND THEN A BETTER COVERAGE OF SHOWERS/STORMS BY MORNING HOURS FOR KFSD AND KSUX...BUT EXITING NORTHEAST FAIRLY QUICKLY. UPSTREAM AND STRONGER WAVE UPSTREAM AROUND RENO NV WILL FOLLOW...AND WILL LIKELY RESULT IN ADDITIONAL CONVECTION ACROSS THE AREA...BUT FOR NOW HELD OFF MENTION UNTIL AFTER 00Z. PROBABILITY OF MVFR FOG IS FAIRLY LOW...LIKELY HIGHEST AROUND KSUX...BUT WILL ALSO HAVE INITIAL INCREASE IN CLOUDS FROM CONVECTION TO SOUTH...AND WILL NOT MENTION ON THIS FORECAST SET. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE...CHENARD SHORT TERM...JM LONG TERM...MJ AVIATION...CHAPMAN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
925 PM CDT SUN JUN 23 2013 .UPDATE... WINDS HAVE GONE LIGHT LATE THIS EVENING UNDER CLEAR SKIES AND SURFACE HIGH PRESSURE RIDGING. THE WINDS WILL TURN SOUTH BEHIND THIS RETREATING HIGH PRESSURE AREA TONIGHT. ALREADY HAVE MID LEVEL WAA CLOUDS/ACCAS AND COOLING TOPS IN WY/SE MT LATE THIS EVENING MOVING QUICKLY EAST. THESE WILL CONTINUE TO MOVE EAST AND MAY BECOME HIGH BASED SHOWERS/THUNDER AS THEY MOVE INTO WESTERN SD AND INTO OUR WESTERN CWA LATER TONIGHT. THE LATEST HRRR MODEL SHOWS SOME SPOTTY QPF LATER TONIGHT. ALREADY HAVE IN SLIGHT CHANCES WEST IN THE CWA AFTER MIDNIGHT. && .PREVIOUS DISCUSSION... .SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT THE ACTIVE SUMMER PATTERN CONTINUES EARLY THIS WEEK AS RETURN FLOW MOISTURE AND INSTABILITY MAKE A QUICK RETURN TO THE WESTERN ZONES OVERNIGHT AND SPREADS EAST MONDAY AND MONDAY EVENING. MODELS ARE AGAIN OFFERING A CHALLENGING FORECAST WITH TIMING AND STRENGTH OF SHORTWAVES AND CONVECTION...BUT THUNDERSTORMS LOOK LIKE A GOOD BET MONDAY NIGHT MOST LOCATIONS AND AGAIN TUESDAY NIGHT IN THE EAST. SPC HAS AREA IN SLIGHT RISK FOR MONDAY NIGHT AND THE EASTERN PORTION FOR TUESDAY. DESPITE RISING HEIGHTS...DEEP SOUTHWEST FLOW ALOFT WILL CONTINUE TO EJECT SHORTWAVES INTO THE UPPER PLAINS. WITH INSTABILITY RETURN IN THE WEST LATE TONIGHT HAVE ADDED SMALL POPS TO THE FORECAST FOR AREAS ALONG AND WEST OF THE MISSOURI RIVER. HEAT...MOISTURE AND INSTABILITY WILL INCREASE THE NEXT FEW DAYS WITH TEMPS CLIMBING INTO THE UPPER 80S AND MID 90S BY TUESDAY. THE HEAT INDEX WILL CLIMB INTO THE MID TO UPPER 90S ON TUESDAY. AS MENTIONED ABOVE...MODELS IN ARE NOT IN VERY GOOD AGREEMENT WITH TIMING OF CONVECTION...BUT OVERALL FEEL CONFIDENT FOR THUNDERSTORMS FOR BOTH MONDAY AND TUESDAY EVENINGS...POSSIBLY SEVERE AS INSTABILITY INCREASES. .LONG TERM...WEDNESDAY THROUGH SUNDAY IT APPEARS THE THEMES RUNNING THROUGHOUT THE EXTENDED ARE WARM AND MOSTLY DRY. AT THIS POINT...POPS/WX MENTION DO NOT SHOW UP IN THE OUT PERIODS BASICALLY UNTIL SATURDAY LATE AFTERNOON/EARLY EVENING. UNTIL THEN...REBOUNDING MID/UPPER LEVEL HEIGHTS ARE FORECAST TO DEVELOP ACROSS THE WESTERN TWO-THIRDS OF THE CONUS STARTING WEDNESDAY AND PERSIST THROUGH THE END OF THE PERIOD. A LOW PRESSURE SYSTEM IS PROGGED TO TRY WORKING THROUGH THE TOP OF THE RIDGE...IN EFFECT...FLATTENING IT SOMEWHAT OVER THE WEEKEND AND BRINGING A SMALL CHANCE AT CONVECTION ACROSS THE CWA BY SATURDAY EVENING. AT THIS TIME...700HPA THERMAL PROGS ARE AT OR ABOVE +14C ON SATURDAY...SO IT WILL TAKE QUITE A BIT OF MOISTURE/INSTABILITY AND STRONG FORCING AROUND TO GET STORMS TO DEVELOP IN THAT WARM OF A MID-LEVEL ENVIRONMENT. SPEAKING OF WARM...WITH HEIGHTS RISING IN THE ATMOSPHERE...A GOOD CHUNK OF THE EXTENDED SHOULD BE LOOKING AT NEAR TO ABOVE NORMAL HIGH TEMPERATURES IN THE 80S AND 90S DURING THE MID TO LATE PORTIONS OF THE WEEK. && .AVIATION... 00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH TONIGHT AND MONDAY. AN UPPER LEVEL LOW PRESSURE TROUGH ALONG WITH RETURNING WAA WILL SPREAD MID LEVEL CLOUDS ACROSS THE REGION THROUGH MONDAY. WITH INSTABILITY ALSO RETURNING/INCREASING...SOME SHOWERS/THUNDERSTORMS SHOULD ALSO DEVELOP MAINLY LATE TONIGHT AND MONDAY. LEFT ANY MENTION OUT OF THE TERMINALS AT THIS TIME WITH THE UNCERTAINTY OF LOCATION AND TIMING INVOLVED. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...MOHR SHORT TERM...SCARLETT LONG TERM...DORN AVIATION...MOHR WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
952 PM CDT SUN JUN 23 2013 .UPDATE... SHORTWAVE OVER SOUTHEASTERN AND EASTERN NEW MEXICO IN THE SOUTHWESTERLY UPPER FLOW ACROSS THE PANHANDLES ALLOWING FOR ADDITIONAL CONVECTION TO DEVELOP IN THE FAR EASTERN PLAINS OF NEW MEXICO MOVING NORTHEAST INTO THE SOUTHWESTERN TEXAS PANHANDLE. EXPANDED THE POPS THROUGH 06Z MONDAY A LITTLE FURTHER WESTWARD TO ACCOUNT FOR THIS ROUND OF CONVECTION. SHORT RANGE MODELS IN GOOD AGREEMENT SHOWING CONVECTION DEVELOPING ACROSS THE NORTHEAST TEXAS AND EASTERN OKLAHOMA PANHANDLES TOWARD 09Z MONDAY. INTRODUCED THE 10 POP RULE OVER THE EASTERN SECTIONS OF THE PANHANDLES TO ACCOUNT FOR THIS POSSIBILITY. DID NOTICE A LONE THUNDERSTORM ACROSS THE SOUTHEASTERN TEXAS PANHANDLE LAST NIGHT AROUND 09Z SUNDAY OR SO...AND CANNOT RULE OUT A SIMILAR SCENARIO ACROSS THE NORTHEASTERN OR EASTERN SECTIONS OF THE FORECAST AREA LATER TONIGHT. LOW LEVEL JET ACROSS THE EASTERN PANHANDLES LATE TONIGHT MAY ALSO HELP ADDITIONAL CONVECTION TO DEVELOP LATE TONIGHT. ADJUSTED WIND AND SKY GRIDS TONIGHT...AND ALSO POPULATED THE SMOKE MANAGEMENT GRIDS WITH THE LATEST NAM DATA AND UPDATED THE LAL AND 20 FOOT WIND GRIDS. OTHERWISE...NO OTHER CHANGES MADE TO PREVIOUS FORECAST AND GRIDS. ALL PUBLIC AND FIRE WEATHER PRODUCTS HAVE BEEN UPDATED AND SENT. SCHNEIDER && .PREV DISCUSSION... /ISSUED 636 PM CDT SUN JUN 23 2013/ AVIATION... 00Z TAF CYCLE A SOUTHWESTERLY UPPER FLOW ALONG WITH AN UPPER TROUGH OVER THE PANHANDLES THIS EVENING AND A DRYLINE LOCATED ACROSS THE WESTERN PANHANDLES WILL ALLOW FOR ISOLATED CONVECTION ACROSS THE OKLAHOMA PANHANDLE AND THE SOUTH CENTRAL AND SOUTHEASTERN TEXAS PANHANDLE THROUGH 05Z MONDAY. CONFIDENCE IN THE CONVECTION MOVING OVER EITHER THE GUYMON OR AMARILLO TAF SITES IS LOW...HOWEVER WILL INCLUDE VCTS REMARK IN PREVAILING GROUP AT BOTH TAF SITES THIS EVENING AND WILL CONTINUE TO MONITOR. OTHERWISE...VFR CONDITIONS WITH MAINLY SCATTERED TO BROKEN HIGH LEVEL CLOUDS AND SOME SCATTERED HIGH BASED LOW CLOUDS DURING THE AFTERNOON HOURS UNTIL AROUND SUNSET OR AROUND 02Z TO 04Z MONDAY WILL PREVAIL. SOUTHEASTERLY TO SOUTHERLY WINDS OF AROUND 10 TO 15 KNOTS OR LESS AT THE DALHART AND GUYMON TAF SITES UNTIL AROUND 04Z TO 06Z MONDAY...THEN INCREASING TO AROUND 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 04Z TO 06Z MONDAY. SOUTHEASTERLY TO SOUTHERLY WINDS OF 15 TO 25 KNOTS WITH HIGHER GUSTS WILL PREVAIL AT THE AMARILLO TAF SITE THROUGH THE TAF FORECAST PERIOD. NOTE TO USERS OF SURFACE OBSERVATION FROM RICK HUSBAND INTERNATIONAL AIRPORT KAMA...COMMUNICATIONS PROBLEM WITH DATA LINE HAS PREVENTED LONG-LINE DISSEMINATION OF SURFACE OBS. DATA COLLECTION PLATFORM AT KAMA ASOS IS FUNCTIONING PROPERLY WITH CONTINUOUS MONITORING OF ALL ELEMENTS BY AMARILLO NATIONAL WEATHER SERVICE FORECAST STAFF. SCHNEIDER PREV DISCUSSION... /ISSUED 319 PM CDT SUN JUN 23 2013/ DISCUSSION... JUST ONE MORE DAY OF THIS ACTIVE WEATHER PATTERN THAT THE REGION HAS BEEN UNDER FOR OVER A WEEK NOW. TONIGHT INTO TOMORROW...PRECIP CHANCES...THOUGH MENTIONABLE...CONTINUE TO DECLINE AS DRY AIR ADVECTION CONTINUES. PRECIPITABLE WATER VALUES ON THIS MORNINGS SOUNDING SHOW 0.79 INCHES...WHICH IS 92 PERCENT OF NORMAL...BUT A FAR CRY FROM THE 1 PLUS INCH VALUES WE/VE SEEN LATELY. IN ADDITION...IN THE WAKE OF THE UPPER LEVEL TROUGH THAT MOVE THROUGH EARLY THIS MORNING...THERE IS SOME UPPER LEVEL SHORT WAVE RIDGING OVER THE REGION. THIS SHOULD KEEP COVERAGE OF STORMS VERY LIMITED. HOWEVER...IT IS INTERESTING TO NOTE THAT THE RAP HIGH RESOLUTION MODEL SHOWS MORE COVERAGE THAN YESTERDAY. IF ANY STORMS DEVELOP EITHER THIS AFTERNOON OR TOMORROW...THE POTENTIAL REMAINS FOR MARGINALLY SEVERE HAIL AND DRY AND HYBRID DOWNBURSTS LEADING TO STRONG WINDS. TUESDAY THROUGH THURSDAY...INCREASING CONFIDENCE WITH VERY GOOD MODEL AGREEMENT AND CONSISTENCY THAT THE RIDGE WILL BUILD OVER THE SOUTHWEST THROUGH THIS PERIOD BRINGING A DRY AND HOT WEATHER PATTERN THROUGH THE WEEK. STAYED CLOSE TO THE PREVIOUS FORECAST STILL FAVORING HIGHER MAX TEMPS IN THE NORTHWESTERN PANHANDLES...WHICH HAVE SEEN VERY LITTLE RAIN...WHILE KEEPING THE SOUTHEASTERN TX PANHANDLE A FEW DEGREES LOWER DUE TO THE WET SOIL CONDITIONS. HOWEVER...BY THE END OF THE WEEK...THESE DIFFERENCES MAY BE NEGLIGIBLE AS THE SOILS DRY. FRIDAY THROUGH SUNDAY...MODELS CONTINUED THE TREND OF SHOWING A PERSISTENT RIDGE CONTINUING THROUGH THIS PERIOD. THE COLD FRONT WHICH WAS SHOWN IN THE GFS TO ARRIVE ON FRIDAY...HAS ALL BUT DISAPPEARED IN THE 12Z RUN. THUS...STAYED CLOSE TO THE PREVIOUS FORECAST WITH HOT AND DRY WEATHER CONTINUING THROUGH THE WEEK. JOHNSON AVIATION... FOR THE 18Z TAFS...ANY ISOLATED LATE AFTERNOON AND EARLY EVENING THUNDERSTORMS ARE EXPECTED TO REMAIN EAST OF TERMINALS. SCATTERED HIGH-BASED CUMULUS OR ALTOCUMULUS WILL BE THE ONLY CLOUDS OTHER THAN CIRRUS FOR THIS FORECAST. WIND SHIFT LINE WHICH IS MOVING ACROSS NORTHWESTERN PART OF FORECAST AREA WILL CAUSE VARIABILITY IN SURFACE WIND DIRECTION AT NORTHERN TERMINALS UNTIL AROUND 22 OR 23Z TODAY...WHEN SOUTHERLY SURFACE WINDS RESUME AND COMMENCE GUSTING TO AROUND 25 KT. FOR KAMA...SOUTHERLY SURFACE WINDS EXPECTED TO PREVAIL...WITH GUSTS ABOVE 25 KT OCCURRING BETWEEN 21Z TODAY AND 06Z MONDAY. VFR FORECAST CONTINUES NEXT 24 HOURS. NOTE TO USERS OF SURFACE OBSERVATION FROM RICK HUSBAND INTERNATIONAL AIRPORT KAMA...COMMUNICATIONS PROBLEM WITH DATA LINE HAS PREVENTED LONG-LINE DISSEMINATION OF SURFACE OBS. DATA COLLECTION PLATFORM AT KAMA ASOS IS FUNCTIONING PROPERLY WITH CONTINUOUS MONITORING OF ALL ELEMENTS BY AMARILLO NATIONAL WEATHER SERVICE FORECAST STAFF. COCKRELL FIRE WEATHER... ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS MAY OCCUR TOMORROW IN THE WESTERN OKLAHOMA AND FAR NORTHWESTERN TEXAS PANHANDLES...THOUGH UNCERTAINTY REMAINS. MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE BELOW 15 PERCENT. HOWEVER...THOUGH WINDS ARE EXPECTED TO BE NEAR 20 MPH...IT IS UNCERTAIN IF THE SURFACE TROUGH WHICH RESULTED IN LIGHTER WINDS TODAY WILL BE A FACTOR TOMORROW AS WELL. THOUGH MINIMUM RELATIVE HUMIDITY VALUES WILL DROP BELOW 20 THROUGH THE REMAINDER OF THE WEEK...AS WE SEE A DRIER PATTERN...NO ADDITIONAL ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED AT THIS TIME AS WINDS SHOULD BE LIGHT. JOHNSON && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 08/11
AREA FORECAST DISCUSSION
NWS AMARILLO TX
636 PM CDT SUN JUN 23 2013 .AVIATION... 00Z TAF CYCLE A SOUTHWESTERLY UPPER FLOW ALONG WITH AN UPPER TROUGH OVER THE PANHANDLES THIS EVENING AND A DRYLINE LOCATED ACROSS THE WESTERN PANHANDLES WILL ALLOW FOR ISOLATED CONVECTION ACROSS THE OKLAHOMA PANHANDLE AND THE SOUTH CENTRAL AND SOUTHEASTERN TEXAS PANHANDLE THROUGH 05Z MONDAY. CONFIDENCE IN THE CONVECTION MOVING OVER EITHER THE GUYMON OR AMARILLO TAF SITES IS LOW...HOWEVER WILL INCLUDE VCTS REMARK IN PREVAILING GROUP AT BOTH TAF SITES THIS EVENING AND WILL CONTINUE TO MONITOR. OTHERWISE...VFR CONDITIONS WITH MAINLY SCATTERED TO BROKEN HIGH LEVEL CLOUDS AND SOME SCATTERED HIGH BASED LOW CLOUDS DURING THE AFTERNOON HOURS UNTIL AROUND SUNSET OR AROUND 02Z TO 04Z MONDAY WILL PREVAIL. SOUTHEASTERLY TO SOUTHERLY WINDS OF AROUND 10 TO 15 KNOTS OR LESS AT THE DALHART AND GUYMON TAF SITES UNTIL AROUND 04Z TO 06Z MONDAY...THEN INCREASING TO AROUND 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 04Z TO 06Z MONDAY. SOUTHEASTERLY TO SOUTHERLY WINDS OF 15 TO 25 KNOTS WITH HIGHER GUSTS WILL PREVAIL AT THE AMARILLO TAF SITE THROUGH THE TAF FORECAST PERIOD. NOTE TO USERS OF SURFACE OBSERVATION FROM RICK HUSBAND INTERNATIONAL AIRPORT KAMA...COMMUNICATIONS PROBLEM WITH DATA LINE HAS PREVENTED LONG-LINE DISSEMINATION OF SURFACE OBS. DATA COLLECTION PLATFORM AT KAMA ASOS IS FUNCTIONING PROPERLY WITH CONTINUOUS MONITORING OF ALL ELEMENTS BY AMARILLO NATIONAL WEATHER SERVICE FORECAST STAFF. SCHNEIDER && .PREV DISCUSSION... /ISSUED 319 PM CDT SUN JUN 23 2013/ DISCUSSION... JUST ONE MORE DAY OF THIS ACTIVE WEATHER PATTERN THAT THE REGION HAS BEEN UNDER FOR OVER A WEEK NOW. TONIGHT INTO TOMORROW...PRECIP CHANCES...THOUGH MENTIONABLE...CONTINUE TO DECLINE AS DRY AIR ADVECTION CONTINUES. PRECIPITABLE WATER VALUES ON THIS MORNINGS SOUNDING SHOW 0.79 INCHES...WHICH IS 92 PERCENT OF NORMAL...BUT A FAR CRY FROM THE 1 PLUS INCH VALUES WE/VE SEEN LATELY. IN ADDITION...IN THE WAKE OF THE UPPER LEVEL TROUGH THAT MOVE THROUGH EARLY THIS MORNING...THERE IS SOME UPPER LEVEL SHORT WAVE RIDGING OVER THE REGION. THIS SHOULD KEEP COVERAGE OF STORMS VERY LIMITED. HOWEVER...IT IS INTERESTING TO NOTE THAT THE RAP HIGH RESOLUTION MODEL SHOWS MORE COVERAGE THAN YESTERDAY. IF ANY STORMS DEVELOP EITHER THIS AFTERNOON OR TOMORROW...THE POTENTIAL REMAINS FOR MARGINALLY SEVERE HAIL AND DRY AND HYBRID DOWNBURSTS LEADING TO STRONG WINDS. TUESDAY THROUGH THURSDAY...INCREASING CONFIDENCE WITH VERY GOOD MODEL AGREEMENT AND CONSISTENCY THAT THE RIDGE WILL BUILD OVER THE SOUTHWEST THROUGH THIS PERIOD BRINGING A DRY AND HOT WEATHER PATTERN THROUGH THE WEEK. STAYED CLOSE TO THE PREVIOUS FORECAST STILL FAVORING HIGHER MAX TEMPS IN THE NORTHWESTERN PANHANDLES...WHICH HAVE SEEN VERY LITTLE RAIN...WHILE KEEPING THE SOUTHEASTERN TX PANHANDLE A FEW DEGREES LOWER DUE TO THE WET SOIL CONDITIONS. HOWEVER...BY THE END OF THE WEEK...THESE DIFFERENCES MAY BE NEGLIGIBLE AS THE SOILS DRY. FRIDAY THROUGH SUNDAY...MODELS CONTINUED THE TREND OF SHOWING A PERSISTENT RIDGE CONTINUING THROUGH THIS PERIOD. THE COLD FRONT WHICH WAS SHOWN IN THE GFS TO ARRIVE ON FRIDAY...HAS ALL BUT DISAPPEARED IN THE 12Z RUN. THUS...STAYED CLOSE TO THE PREVIOUS FORECAST WITH HOT AND DRY WEATHER CONTINUING THROUGH THE WEEK. JOHNSON AVIATION... FOR THE 18Z TAFS...ANY ISOLATED LATE AFTERNOON AND EARLY EVENING THUNDERSTORMS ARE EXPECTED TO REMAIN EAST OF TERMINALS. SCATTERED HIGH-BASED CUMULUS OR ALTOCUMULUS WILL BE THE ONLY CLOUDS OTHER THAN CIRRUS FOR THIS FORECAST. WIND SHIFT LINE WHICH IS MOVING ACROSS NORTHWESTERN PART OF FORECAST AREA WILL CAUSE VARIABILITY IN SURFACE WIND DIRECTION AT NORTHERN TERMINALS UNTIL AROUND 22 OR 23Z TODAY...WHEN SOUTHERLY SURFACE WINDS RESUME AND COMMENCE GUSTING TO AROUND 25 KT. FOR KAMA...SOUTHERLY SURFACE WINDS EXPECTED TO PREVAIL...WITH GUSTS ABOVE 25 KT OCCURRING BETWEEN 21Z TODAY AND 06Z MONDAY. VFR FORECAST CONTINUES NEXT 24 HOURS. NOTE TO USERS OF SURFACE OBSERVATION FROM RICK HUSBAND INTERNATIONAL AIRPORT KAMA...COMMUNICATIONS PROBLEM WITH DATA LINE HAS PREVENTED LONG-LINE DISSEMINATION OF SURFACE OBS. DATA COLLECTION PLATFORM AT KAMA ASOS IS FUNCTIONING PROPERLY WITH CONTINUOUS MONITORING OF ALL ELEMENTS BY AMARILLO NATIONAL WEATHER SERVICE FORECAST STAFF. COCKRELL FIRE WEATHER... ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS MAY OCCUR TOMORROW IN THE WESTERN OKLAHOMA AND FAR NORTHWESTERN TEXAS PANHANDLES...THOUGH UNCERTAINTY REMAINS. MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE BELOW 15 PERCENT. HOWEVER...THOUGH WINDS ARE EXPECTED TO BE NEAR 20 MPH...IT IS UNCERTAIN IF THE SURFACE TROUGH WHICH RESULTED IN LIGHTER WINDS TODAY WILL BE A FACTOR TOMORROW AS WELL. THOUGH MINIMUM RELATIVE HUMIDITY VALUES WILL DROP BELOW 20 THROUGH THE REMAINDER OF THE WEEK...AS WE SEE A DRIER PATTERN...NO ADDITIONAL ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED AT THIS TIME AS WINDS SHOULD BE LIGHT. JOHNSON && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 08/11
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1143 PM CDT FRI JUN 21 2013 .UPDATE... CONVECTION WAS WINDING DOWN AT THIS HOUR. LIGHT SHOWERS AND A FEW ISOLATED THUNDERSTORMS WERE THE ONLY ACTIVITY THAT REMAINED. THEREFORE THE SEVERE THUNDERSTORM WATCH WAS CANCELLED. && .AVIATION... A FEW LIGHT SHOWERS REMAINED THIS EVENING BUT ARE NOT EXPECTED TO AFFECT EITHER TAF SITE. A WEAK OUTFLOW BOUNDARY MAY BRIEFLY SHIFT WINDS TO THE NORTH AT KLBB WITHIN THE NEXT ONE TO TWO HOURS BUT WIND SPEEDS ARE ANTICIPATED TO BE LIGHT. SOUTHERLY WINDS WILL INCREASE AGAIN ON SATURDAY AFTERNOON AND MAY LEAD TO LIGHT VISIBILITY RESTRICTIONS DUE TO BLOWING DUST. ANOTHER CHANCE OF THUNDERSTORMS WILL ALSO EXIST SATURDAY EVENING BUT CONFIDENCE IS NOT HIGH ENOUGH TO PLACE IN THE TAF AT THE MOMENT. && .PREV DISCUSSION... /ISSUED 652 PM CDT FRI JUN 21 2013/ UPDATE... DISTURBANCE EDGING INTO WESTERN NEW MEXICO EXPECTED TO LEAD TO INCREASING THUNDERSTORMS THROUGH THE EVENING...SHOULD PERSIST LATER THAN LAST NIGHT. INITIAL ACTIVITY NEAR THE NEW MEXICO BORDER FAIRLY ISOLATED AND STILL UNCERTAIN HOW MUCH ADDITIONAL DEVELOPMENT WILL OCCUR...MIXED SIGNALS FROM SHORT-TERM SOLUTIONS. HAIL AND HIGH WIND THREAT SHOULD TRANSITION TO OUTFLOW DRIVEN STORMS WITH WIND AND DUST AS PROBABLE ISSUES. SEVERE THUNDERSTORM WATCH VALID UNTIL 2 AM CDT TONIGHT. RMCQUEEN AVIATION... A FEW ISOLATED THUNDERSTORMS HAVE DEVELOPED NEAR THE TEXAS/NEW MEXICO STATE LINE AND WILL CONTINUE TO MOVE EAST THIS EVENING. HOWEVER...CONFIDENCE IS LOW ON WHETHER ANY STORMS WILL AFFECT EITHER TAF SITE. WINDS WILL PICK UP TOMORROW AFTERNOON AGAIN AND LEAD TO LIGHT VISIBILITY RESTRICTIONS DUE TO BLOWING DUST. PREV DISCUSSION... /ISSUED 316 PM CDT FRI JUN 21 2013/ SHORT TERM... FORECAST REVOLVES AROUND THUNDER CHANCES LATE THIS AFTERNOON INTO TONIGHT. THE REGION REMAINS UNDER SOUTHWEST FLOW ALOFT...WITH ONE NOTABLE SHORTWAVE TROUGH ACROSS THE PANHANDLES EXITING TO THE NORTHEAST AND ANOTHER AREA OF LIFT SEEN ON WATER VAPOR IMAGERY APPROACHING THROUGH AZ. WAS CONCERNED THE FIRST WAVE COULD SPARK A FEW STORMS ACROSS THE EASTERN ZONES THIS AFTERNOON...AS EARLIER RAP AND HRRR SOLUTIONS SUGGESTED...BUT THEY HAVE NOW BACKED OFF ON THIS AND WITH WAVE EXITING PROSPECTS FOR THIS ARE LOW. ALTHOUGH WE WILL BE POSITIONED BETWEEN THE TWO SYNOPTIC AREAS OF FORCING FOR ASCENT THIS EVENING...STRONG HEATING AND GOOD MOISTURE LEVELS WERE RESULTING IN STRONG INSTABILITY AND MINIMAL INHIBITION OVER MUCH OF THE REGION...WITH 19Z MLCAPE VALUES ANALYZED AOA 2500 J/KG FOR MOST OF THE FA. IN ADDITION...AN AREA OF LOW-LEVEL MOISTURE CONVERGENCE WAS NOTED FROM THE CENTRAL TEXAS PANHANDLE SOUTHWESTWARD INTO THE LEE TROUGH ACROSS SOUTHEASTERN NEW MEXICO. UP TO THIS POINT...STORMS HAVE BEEN CONFINED TO LOCATIONS IMMEDIATELY ALONG AND EAST OF THE SACRAMENTO MOUNTAINS...BUT EXPECT ADDITIONAL DEVELOPMENT NORTHEASTWARD FROM THERE UP INTO THE WESTERN/CENTRAL PANHANDLE THROUGH LATE THIS AFTERNOON. THE ACTIVITY MAY TRY AND CONGEAL SOMEWHAT AS IT MOVES EASTWARD ACROSS THE CAPROCK THIS EVENING...PERHAPS MAKING IT INTO THE ROLLING PLAINS LATER TONIGHT...THOUGH IT SHOULD BE WANING IN INTENSITY BY LATE EVENING. EARLY ON...STRONG INSTABILITY AND WEAK TO MODEST WIND SHEAR WILL SUPPORT A SEVERE THREAT WITH LARGE HAIL...DAMAGING WINDS...LOCALLY HEAVY RAIN AND THE PROSPECTS FOR BLOWING DUST. HAVE EXPANDED CHANCE POPS TO ENCOMPASS NEARLY THE ENTIRE SOUTHERN PANHANDLE AND SOUTH PLAINS THROUGH 06Z BEFORE DROPPING POPS BELOW 15 PERCENT AFTER 06Z. TEMPERATURES TONIGHT WILL BE MILD AS MOIST SOUTHERLY LOW-LEVEL FLOW CONTINUES AND HAVE GONE WITH TEMPERATURES SIMILAR TO WHAT WE SAW THIS MORNING. TOMORROW WILL BRING ANOTHER HOT DAY WITH LITTLE CHANGE IN THE OVERALL PATTERN. STRONG DAYTIME HEATING...WITH HIGHS IN THE MIDDLE 90S AND SUFFICIENT MOISTURE...COMBINED WITH CONVERGENCE ALONG A SFC TROUGH/DRYLINE WILL BRING ANOTHER THREAT OF STRONG/SEVERE STORMS...FAVORING THE WESTERN ZONES INITIALLY IN THE LATE AFTERNOON HOURS...THEN EXPANDING EAST. LONG TERM... MAIN ISSUE TODAY IS TIMING TRANSITION FROM AFTN THUNDERSTORM REGIME ACROSS THE WRN ZONES TO HOT AND DRY AREAWIDE. 12Z MODEL RUNS NOW A BIT SLOWER IN REPLACING THE WRN CONUS UPPER TROUGH WITH AN AMPLIFYING RIDGE. IT NOW LOOKS LIKE THE LEE SFC TROUGH COULD REMAIN ACTIVE INTO MONDAY WITH SWLY FLOW ALOFT BEFORE THAT RIDGE AMPLIFICATION BEGINS OVER THE SRN ROCKIES. THAT SHOULD FINALLY SHUT PRECIPITATION DOWN OVER THE AREA. AS A RESULT HAVE EXTENDED SLIGHT CHANCE MENTION INTO MONDAY AFTN AND EVENING. TEMPS WILL THEN WARM AS THE RIDGE BUILDS OVER THE ROCKIES AND LOW LEVELS DRY OUT A BIT...WITH HIGH TEMPS LIKELY APPROACHING 10F WARMER THAN NORMAL BY WEDNESDAY AND THURSDAY. WILL END WITH MENTION OF AN OUTSIDE SHOT OF PRECIP REENTERING THE PICTURE TOWARD FRIDAY AS NORTHERLY MID TO UPPER FLOW OVER THE PLAINS COULD SEND A COLD FRONT AND/OR UPPER DISTURBANCE TOWARD THE FCST AREA. FOR NOW THAT POSSIBILITY TOO REMOTE TO ADD TO FCST. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 64 93 63 94 63 / 30 20 20 20 20 TULIA 66 94 66 96 67 / 30 20 20 20 20 PLAINVIEW 68 93 68 95 68 / 30 20 20 20 20 LEVELLAND 69 93 68 93 69 / 30 20 20 20 20 LUBBOCK 73 93 70 96 69 / 30 10 20 20 20 DENVER CITY 67 95 68 96 69 / 30 20 20 20 20 BROWNFIELD 70 94 68 95 70 / 30 20 20 20 20 CHILDRESS 72 97 70 97 70 / 20 10 10 10 10 SPUR 72 95 71 95 70 / 20 10 10 10 10 ASPERMONT 73 97 72 97 71 / 20 10 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 01
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
829 PM EDT SUN JUN 23 2013 .SYNOPSIS... A TYPICAL SUMMER PATTERN CONTINUES WITH HIGH PRESSURE SITUATED ACROSS THE SOUTHEAST AND SOUTHWEST FLOW KEEPING US WARM AND HUMID WITH A DAILY THREAT OF SHOWERS AND STORMS THROUGH AT LEAST MIDWEEK. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST LATE IN THE WEEK WITH MORE WIDESPREAD SHOWERS AND THUNDERSTORMS LIKELY. && .NEAR TERM /THROUGH MONDAY/... AS OF 310 PM EDT SUNDAY... THE OVERALL WEATHER PATTERN HAS AN UPPER LEVEL TROUGH TRACKING NORTHEAST FROM THE SOUTHERN OHIO VALLEY THIS AFTERNOON TO THE NORTHERN MID ATLANTIC TOMORROW. WHILE THIS TROUGH IS MOVING NORTHEAST...AN UPPER LEVEL RIDGE WILL TRACK SOUTHWEST FROM BERMUDA TOWARDS FLORIDA. EVENTUALLY THIS RIDGE WILL RESIDE OVER THE GULF STATES BY THE MIDDLE OF THE WEEK. FOR THE IMMEDIATE AREA...THERE WILL BE VERY LITTLE CHANGE IN THE WEATHER PATTERN OVER THE NEXT 24 HOURS. CONVECTION THIS AFTERNOON HAS BEEN SLOW TO DEVELOP BY SOME MID LEVEL DRY AIR. THERE ARE A FEW CELLS LIVING OFF OF MOISTURE AND MODEST INSTABILITIES THAT COULD GENERATE MORE ACTIVITY FROM GUST FRONTS AS THEY COLLAPSE. CONFIDENCE IS LOW ON AREAL COVERAGE...THEREFORE HAVE PLACED 20-30 POP ACROSS MOST OF THE AREA. THE BETTER COVERAGE OF STORMS ARE SOUTH OF THE AREA AND WILL MAKE A RUN AT RNK SOUTHERN TIER COUNTIES LATER THIS AFTERNOON INTO THIS EVENING. THIS AFTERNOON AND EVENING THUNDERSTORMS WILL FADE WITH THE SETTING OF THE SUN. OVERNIGHT...MUGGY CONDITIONS WITH PATCHY VALLEY FOG DEVELOPING DURING THE EARLY MORNING HOURS. ON MONDAY...CONTINUED HUMID CONDITIONS WITH HIT AND MISS DIURNAL CONVECTION. IF SHOWERS AND THUNDERSTORMS ARE HELD DOWN TOMORROW...THE AREA WILL SEE SLIGHTLY WARMER TEMPERATURES THAN TODAY. TEMPERATURES TOMORROW WILL RANGE FROM THE UPPER 70S TO MID 80S ACROSS THE MOUNTAINS TO THE UPPER 80S IN THE EAST. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... AS OF 215 PM EDT SUNDAY... HEIGHTS SHOULD CONTINUE TO SLOWLY BUILD INTO MID WEEK AS SURFACE RIDGING REMAINS OFFSHORE WITH A DEEP WEST TO SW FLOW IN PLACE. THIS WILL RESULT IN A PERSISTENT PATTERN OF DIURNAL CONVECTION DURING HEATING...AND MAINLY CLEAR/PC AT NIGHT ONCE ANY EVENING SHRA/TSRA FADE. HOWEVER APPEARS BEST COVERAGE OF SHOWERS/STORMS MAY COME ON TUESDAY AS A WEAK MID LEVEL WAVE RIDES THROUGH THE ZONAL FLOW AROUND THE RIDGE AND PERHAPS COINCIDES WITH MAX HEATING. THIS SUPPORTED BY THE LASTEST SREF AND FORECAST LOBE OF HIGHER 85H THETA-E THAT LOOKS TO ROTATE IN FROM THE WEST TUESDAY AFTERNOON. LACK OF BACKING LOW LEVEL FLOW COULD INHIBIT COVERAGE A BIT SO STAYING WITH OVERALL CHANCE POPS TUESDAY INTO TUESDAY EVENING. PASSAGE OR SPLIT OF THIS FEATURE SHOULD ACT TO ENHANCE THE WESTERLY FLOW ON WEDNESDAY AS THE CWA SLIDES IN BETWEEN THE TUESDAY FEATURE AND THE NEXT STRONGER UPSTREAM VORT. THIS MAY ALLOW FOR A BIT MORE CONVERGENCE WESTERN SLOPES WHILE LIMITING COVERAGE EAST OF THE MOUNTAINS DESPITE DECENT CAPES. THEREFORE TRIMMED BACK POPS IN ALL EXCEPT THE WESTERN AREAS WHERE WILL RUN WITH HIGHER CHANCES...RANGING TO ONLY OVERALL SLIGHT POPS OUT EAST. INCREASED RIDGING ALOFT ALONG WITH WARMING 85H TEMPS TO AROUND +20C AND WEST WINDS WILL PUSH HIGHS ABOVE 90 IN THE PIEDMONT/FOOTHILLS WITH 80S ELSW BOTH TUE/WED. LOWS SHOULD BE QUITE MUGGY AND MOSTLY IN THE 60S GIVEN MOST DEWPOINTS WHICH MAY HOLD SOME SPOTS OVER THE SE ABOVE 70. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 1210 PM EDT SUNDAY... FLAT UPPER RIDGE OVER THE EASTERN U.S. WILL AGAIN BREAK DOWN THROUGH THE PERIOD WITH PERIODIC S/W ENERGY SPILLING SE AHEAD OF YET ANOTHER COLD FRONT THAT WILL LEAD TO MORE ERN 5H TROFFINESS BY THE WEEKEND. TIMING OF FEATURES OFF MODELS WITHIN THIS TRANSITIONAL PERIOD FROM ZONAL FLOW TO AN EVOLVING BAGGY TROUGH REGIME WILL REMAIN TRICKY BUT GIVEN HIGH PWATS/HEATING AND UPPER ENERGY APPEARS THINGS WILL STAY UNSETTLED AHEAD OF THE BOUNDARY. THIS WOULD BRING DAILY CONVECTIVE CHANCES TO MOST SECTIONS THU/FRI...WITH FOCUS OVER THE WEST THU AFTERNOON PER AN INIT WAVE...AND THEN ACROSS THE AREA FRIDAY AHEAD OF THE FRONT WHERE WILL BE AIDED IN THE EAST BY LEE TROFFINESS. FRONT SHOULD CROSS THE AREA ON SATURDAY BUT MAY SLOW OVER THE PIEDMONT INTO SATURDAY NIGHT UNTIL THE 5H TROF SHARPENS/DIGS MORE AND HELPS PUSH IT EAST. THIS MAY LEAD TO ANOTHER ROUND OF SHOWERS SAT AFTERNOON ESPCLY EAST WITH DRIER AIR ARRIVING MOST SPOTS BEHIND THE BOUNDARY ON SUNDAY. VERY WARM TEMPS WITH HIGHS IN THE 80S WEST...TO LOW/MID 90S AHEAD OF THE FRONT THU WILL GET CLIPPED BACK TO 70S/ARND 80 MOUNTAINS...AND LOW/MID 80S EAST BY SUNDAY. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... AS OF 800 PM EDT SUNDAY NOT MUCH CHANGE FROM THE PREVIOUS TAF DISCUSSION. VISIBLE SATELLITE SHOWS A CLEARING TREND ACROSS THE REGION. THE HRRR MODEL SHOWS LITTLE CLOUD COVER THROUGH THE EVENING. LWB IS THE ONLY LOCATION EXPECTED TO DROP DOWN TO IFR CIG/VISBYS MONDAY MORNING DUE TO FOG. PATCHY FOG WILL AFFECT OTHER LOCATIONS AS WELL...HOWEVER AT THIS POINT ONLY EXPECT MVFR VISBYS AT THE OTHER TAF LOCATIONS. BY 12Z DAYTIME HEATING WILL ERODE WHATEVER FOG IS LEFT. BACKED OFF ON THE MENTION OF ANY SHOWERS OR THUNDERSTORMS IN THE TAFS FOR MONDAY. SOME SHORT WAVE ENERGY SWINGING THROUGH THE REGION...ALONG WITH A CONTINUED SOUTHERLY FLOW WILL KEEP THE REGION WARM AND HUMID SO AFTERNOON AND EVENING POP UP SHOWERS AND THUNDERSTORMS ARE EXPECTED... BUT AT THIS POINT THE ACTIVITY APPEARS TO BE SCATTERED ENOUGH TO LEAVE ANY MENTION OUT OF ALL LOCATIONS. .AVIATION EXTENDED... WE WILL BE TRANSITIONING FROM A FLAT UPPER RIDGE TO A BLOCKY PATTERN WITH AN EASTERN TROF/WESTERN RIDGE THROUGH THE EXTENDED PERIOD. SFC HIGH OFF THE EAST COAST WILL KEEP WARM AND MOIST AIR OVER THE REGION WITH A SERIES OF WAVES RIPPLING THROUGH THE FLOW. THIS WILL PRIMARILY LEAVE US WITH AN UNSTABLE AIRMASS IN A WEAKLY FORCED CONVECTIVE ENVIRONMENT THROUGH MIDWEEK. EXPECT A DIURNAL PATTERN OF CONVECTION WITH VFR IN THE MORNING...THEN MVFR WITH SHRA/TSRA IN THE AFTERNOON AND EVES...THEN POSSIBLE IFR WITH NOCTURNAL FOG/STRATUS. WASH...RINSE...REPEAT. LOOKING LIKE LATTER PORTION OF THE WEEK WILL BE MORE ACTIVE. AS THE PATTERN FINALLY BECOMES MORE AMPLIFIED AND THE ERN TROF SINKS DOWN INTO THE REGION...IT SHOULD PUSH A COLD FRONT THROUGH SATURDAY INTO SUNDAY WITH BETTER AVIATION CONDITIONS THEREAFTER. EXPECT WINDS TO REMAIN ON THE LIGHT SIDE UNTIL THURSDAY WHEN LOW LEVEL WIND FIELD BEGINS TO INCREASE AS TROF BUILDS DOWN. && .EQUIPMENT... AS OF 1225 PM EDT SUNDAY... DANVILLE ASOS VISIBILITY SENSOR REMAINS INOP AND EXPECTED TO BE FIXED EARLY THIS WEEK. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/WP NEAR TERM...RCS SHORT TERM...JH LONG TERM...JH AVIATION...CF/MBS EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS SPOKANE WA
815 AM PDT Sat Jun 22 2013 .SYNOPSIS... Lingering showers from the recent storm system will taper off today. Temperatures will warm to near normal on Sunday. More wet and cool weather will arrive on late Sunday and persist through mid week followed by another warming, dry period to close out the work-week. Temperatures by the end of the week could be the hottest of the year so far. && .DISCUSSION... Updates to the forecast this morning concern the coverage of showers and thunderstorms this afternoon. Instability this afternoon is decent, with some guidance showing up to 500 J/kg CAPE across the northern/eastern mountains (GFS has much less instability). In addition, satellite imagery shows minor waves moving down from central BC which could aid the lift. Low level moisture is plentiful with dew points around 50, so no problem there. With all this in mind, I`ve increased our chances of rain for this afternoon/evening across the northern/eastern mountains. Trajectory of the showers could bring a few of them across the Spokane/CdA metro area but I`m not confident of thunder there. The HRRR and 4km WRF show some organized convection moving down from BC and clipping the WA/BC border this afternoon, which is where my highest PoPs are. They both show some decent storms, but keep them north of the border. So this will need to be monitored. Right now I`m not expecting any strong thunderstorms. RJ && .AVIATION... 12Z TAFS: A weak weather disturbance moving south out of BC will continue to generate mid level clouds across much of the western basin into the northern mountains of eastern WA. Farther east across extreme eastern WA and into the ID Panhandle, early morning clearing has allowed fog and low stratus to develop in many of the valleys. This fog (or low stratus) may affect the KGEG, KSFF, KCOE, KPUW and KLWS TAF sites. Late June sunshine should mix this out by around 16Z. Scattered showers and isolated thunderstorms will develop over the mountains of NE WA and N ID this afternoon and evening but chances are low that this will affect any TAF sites. /EK && .PRELIMINARY POINT TEMPS/POPS... Spokane 70 51 77 55 70 53 / 20 10 0 40 60 70 Coeur d`Alene 69 48 76 55 69 53 / 20 10 10 20 60 70 Pullman 70 47 77 53 69 53 / 10 0 0 40 60 60 Lewiston 78 54 83 57 75 56 / 0 0 0 40 50 60 Colville 75 48 79 56 72 56 / 60 50 10 20 60 70 Sandpoint 69 45 76 54 69 54 / 30 30 10 20 70 80 Kellogg 66 48 74 54 67 53 / 20 20 10 20 70 70 Moses Lake 80 53 82 58 75 55 / 0 0 10 40 50 40 Wenatchee 80 57 80 58 74 54 / 0 0 10 50 60 40 Omak 79 54 80 57 73 56 / 10 10 10 40 60 60 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
955 PM CDT SUN JUN 23 2013 NEW INFORMATION ADDED TO UPDATE SECTION .UPDATE... ISSUED AT 943 PM CDT SUN JUN 23 2013 HAVE REMOVED PCPN CHANCES FOR THE REST OF TONIGHT. DAYTIME INSTABILITY HAS WANED AND CONVERGENCE ALONG THE BOUNDARY THAT BISECTS THE CWA FROM NE TO SW (SEE DEW POINT GRADIENT) HAS WEAKENED. 850 MB FLOW IS EXPECTED TO CONTINUE TO VEER WEST OVERNIGHT...WHICH WILL BRING DRIER AIR INTO THE REGION. PRECIPITABLE WATER ON THE MPX RAOB DROPPED FROM 1.72 INCH AT 12Z TO 0.77 INCH AT 00Z. DISTURBANCE OVER NORTHEAST COLORADO IS EXPECTED TO LIFT NE TOWARD WI BY MONDAY EVENING. THE LLJ IS ALSO EXPECTED TO BACK SW AND INCREASE UPSTREAM OF THE REGION...SO PCPN CHANCES SHOULD INCREASE AGAIN TOMORROW NIGHT. && .SHORT TERM...TONIGHT AND MONDAY ISSUED AT 252 PM CDT SUN JUN 23 2013 THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE WARM FRONT HAS MOVED THROUGH MOST OF WISCONSIN EXCEPT FOR FAR NORTHEAST WISCONSIN EARLY THIS AFTERNOON. SOME REMNANT STORMS FROM AN EARLIER LINE OF CONVECTION ARE MOVING ACROSS SOUTHERN WISCONSIN...BUT STARTING TO SEE SIGNS OF BEEFY CU DEVELOPING FARTHER NORTH FROM WAUSHARA COUNTY TO THE WESTERN UPPER PENINSULA. THIS IS IN A REGION OF BUILDING ML CAPES FROM 1000-1400 J/KG. STILL PLENTY OF TIME FOR FURTHER DESTABILIZATION TO OCCUR...WITH LIFT VIA SHORTWAVE OVER NORTHWEST WISCONSIN. AM STILL EXPECTING STORMS TO FIRE THOUGH IT MAY STILL HAVE A COUPLE HOURS TO GO. ACTUAL FRONT LIES ACROSS EASTERN MINNESOTA AND CLEARING SKIES ARE MOVING INTO SOUTHWEST MINNESOTA. IMPACTS FROM CONVECTION ARE THE MAIN FORECAST CONCERN IN THE SHORT TERM. TONIGHT..SHORTWAVE OVER NORTHWEST WISCONSIN WILL LIFT NORTHEAST AND CLEAR NORTHEAST WISCONSIN IN THE EVENING. FORCING ALONG THE TAIL OF THIS VORT AND FURTHER DESTABILIZATION SHOULD ALLOW SCT STORMS TO MOVE ACROSS NORTHEAST WISCONSIN IN THE EVENING. WINDS AT 700MB ARE PRETTY STRONG AT 45 TO 50 KTS...SO ANY STORMS WILL HAVE POTENTIAL AT CREATING DAMAGING WIND GUSTS AND SMALL HAIL. LOSS OF HEATING AND EXITING OF THE TAIL OF THE VORT SHOULD LET THE CONVECTION DIMINISH AND/OR EXIT BY MID TO LATE EVENING. ACTUAL SURFACE FRONT WILL DROP INTO NORTH-CENTRAL WISCONSIN AFTER MIDNIGHT. CONVERGENCE ALONG THE FRONT IS VERY WEAK AND THERE IS NO SUPPORT ALOFT...SO COULD SEE SOME LOW CLOUDS ALONG THE FRONT...MUCH NOT MUCH ELSE. WILL END POPS FROM NW TO SE AFTER MIDNIGHT. MUGGY LOWS IN THE MID TO UPPER 60S. MONDAY...SURFACE FRONT WILL STALL ACROSS NORTHERN WISCONSIN IN THE MORNING. PROGGED SOUNDINGS AND UPSTREAM SATELLITE IMAGERY SHOW PLENTY OF DRY AIR THROUGH THE COLUMN AND PARTLY TO MOSTLY CLEAR SKIES. NO CLEAR TRIGGERS UPSTREAM EITHER SO WILL GO WITH A DRY BUT PARTLY CLOUDY START TO THE DAY. COME AFTERNOON...AN 86/69 PARCEL OVER THE FOX VALLEY WILL RESULT IN 3000 J/KG OF ML CAPE AND VERY LITTLE CIN. CONVECTIVE TEMPS ARE IN THE LOW 90S AND DO NOT SEE A TRIGGER...BUT PERHAPS THE LAKE BREEZE CAN CREATE THE NECESSARY CONVERGENCE FOR A STORM OR TWO TO POP. WILL KEEP A SLIGHT CHANCE OF A STORM OVER CENTRAL AND NORTHEAST WISCONSIN WHERE INSTABILITY IS MAXIMIZED. HIGHS MAINLY IN THE MID 80S. .LONG TERM...MONDAY NIGHT THROUGH SUNDAY ISSUED AT 252 PM CDT SUN JUN 23 2013 MEDIUM RANGE MODELS ARE IN GREATER DISAGREEMENT THAN THE LAST FEW DAYS...ESPECIALLY WITH A POSSIBLE CONVECTIVE COMPLEX LATE MONDAY NIGHT OR TUESDAY AND AGAIN WEDNESDAY NIGHT WITH THE POSSIBLE FORMATION OF A CLOSED LOW OVER WISCONSIN OR UPPER MICHIGAN. AS FAR AS LATE MONDAY NIGHT AND TUESDAY GOES IT LOOKS LIKE THE GFS IS EXHIBITING SOME SORT OF CONVECTIVE FEEDBACK PRODUCING A CLOSED UPPER LOW THAT MOVES ACROSS MINNESOTA AND WISCONSIN PRODUCING CONSIDERABLE CONVECTION. THIS IS LIKELY OVERDONE AND PREFER THE FLATTER AND SLOWER UPPER SYSTEM THAT SHOULD BRING SHOWERS AND THUNDERSTORMS TUESDAY AFTERNOON AND EVENING. THE GFS ALSO FORECASTS A CLOSED UPPER LOW WEDNESDAY NIGHT AND THURSDAY OVER THE WESTERN GREAT LAKES WHICH SEEMS OVERDONE CONSIDERING THE CURRENT PATTERN. CANNOT TOTALLY DISCOUNT THE GFS AS IT HAS SOME SUPPORT FROM THE NAM BUT THE ECMWF IS MUCH FASTER AND WEAKER. WARM AND HUMID WEATHER EXPECTED THROUGH THURSDAY. AFTER THURSDAY THE MODELS DO AGREE THAT AN UPPER RIDGE WILL DEVELOP OVER THE WESTERN UNITED STATES WITH CYCLONIC NORTHWEST FLOW OVER WISCONSIN. THIS SHOULD BRING COOLER AND DRIER AIR TO THE REGION BY FRIDAY AND SATURDAY. WHILE IT SHOULD BE GENERALLY DRY FRIDAY AND SATURDAY THERE COULD BE SCATTERED DIURNAL SHOWERS WITH COLD TEMPERATURES ALOFT. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 617 PM CDT SUN JUN 23 2013 HARD TO UNDERSTAND WHY STORMS HAVE NOT DEVELOPED THIS AFTERNOON...WITH PLENTY OF MOISTURE/INSTABILITY AND CONVERGENCE OVER NE/EC WI. GIVEN THE CURRENT TRENDS...WILL ONLY CARRY A VCTS AT THE GRB TAF SITE FOR AN HOUR...OTHERWISE DRY. GIVEN THAT THE LOW-LEVEL JET IS EXPECTED TO WEAKEN AND VEER TO A WESTERLY DIRECTION...CONFIDENCE IN TSTMS IS TOO LOW TO MENTION FOR THE REST OF THE TAF PERIOD. BEST ESTIMATE RIGHT NOW IS THAT SOME CONVECTION WILL FIRE MONDAY NIGHT...AS A WEAK UPPER DISTURBANCE TRACKS THROUGH THE AREA AND A SOUTHWESTERLY LOW-LEVEL JET REDEVELOPS. MAIN AVIATION CONCERN FOR THIS TAF PERIOD WOULD APPEAR TO BE FOG POTENTIAL LATE TONIGHT...ALTHOUGH WILL ONLY MENTION MVFR VSBYS...EXPECT AT RHI WHERE SOME IFR CONDITIONS MAY OCCUR. HAVE REMOVED THE MENTION OF LLWS THIS EVENING...AS EARLY DATA FROM THE GRB RAOB ONLY SHOWED WINDS AROUND 25 KTS JUST OFF THE SURFACE. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE.........KIECKBUSCH SHORT TERM.....MPC LONG TERM......RDM AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
904 PM CDT SUN JUN 23 2013 .UPDATE... THE TRENDS OF THE HRRR ARE ENCOURAGING FOR THE OVERNIGHT HOURS. THE EARLIER CONVECTION TO THE SOUTH AND ITS EXTENSIVE CLOUD COVER HAVE HELPED STABILIZE THINGS FOR THE TIME BEING. ALSO...DEEP SHEAR VALUES REMAIN VERY LOW. CURRENTLY NOT SEEING ANY TRIGGERS TO SUPPORT ANY WIDESPREAD ELEVATED CONVECTION THROUGH THE OVERNIGHT HOURS. HOWEVER...JUST CAN/T RULE IT OUT COMPLETELY. OUR NEXT ROUND OF RAIN SHOULD ARRIVE BY AROUND SUNRISE ON MONDAY. THIS ACTIVITY IS STARTING TO GET ORGANIZED OVER SOUTHERN IOWA WHERE THE BEST LOW LEVEL JET INTERACTION IS OCCURRING. THAT/S EXPECTED TO LIFT NORTHEAST INTO SOUTHERN WISCONSIN DURING THE MORNING. GIVEN THE HIGH PRECIPITABLE WATER VALUES...WILL KEEP THE FLASH FLOOD WARNING GOING. ANY STORMS WILL PRODUCE COPIOUS RAINFALL AMOUNTS THAT COULD CAUSE PROBLEMS ACROSS THE WESTERN FORECAST AREA. && .AVIATION/06Z TAFS/... GENERALLY EXPECT VFR CONDITIONS THROUGH THE PERIOD. ONLY EXCEPTIONS ARE THE POTENTIAL FOR SOME MVFR VSBYS DUE TO FOG LATE TONIGHT INTO MONDAY MORNING. THE OTHER IS THE POTENTIAL FOR BRIEF MVFR CONDITIONS IN AND AROUND THUNDERSTORMS. BELIEVE ANY THUNDERSTORM CHANCES WILL HOLD OFF UNTIL AFTER 15Z AT ALL THE TAF SITES...THEN WE COULD SEE STORMS ON AND OFF DURING THE DAY ON MONDAY...DIMINISHING BY EVENING. && .PREV DISCUSSION... /ISSUED 341 PM CDT SUN JUN 23 2013/ VERY SHORT TERM...TONIGHT AND MONDAY. TONIGHT - CONFIDENCE...LOW SURFACE/UPPER LOW LIFTING NORTH FROM NORTH DAKOTA. ONGOING CONVECTION DRIVEN BY OUTFLOW AHEAD OF DECAYING IOWA COMPLEX. NICE LINE MAINLY SOUTH OF THE BORDER WILL SHIFT EAST LATE THIS AFTERNOON SETTING UP A DRY EVENING FOR A WHILE. TRENDS IN HRRR SUGGEST ACTIVITY WILL RE-FIRE LATER TONIGHT WITH ARRIVAL OF A RENEWED 850 MILLIBAR JET LET. HOWEVER NOW LATCHING ONTO THE MISSOURI COMPLEX THIS RENEWED DEVELOPMENT SKEWED FURTHER SOUTHWEST INTO IOWA. THE 12Z SPC 4KM WRF ALSO SHOWS POTENTIAL FOR REDEVELOPMENT WITH THE 850 JET...AND WOULD FAVOR A MORE NORTHERN SOLUTION. IN ADDITION MODELS SHOW SOME DIVERGENCE WITH RIGHT REAR QUADRANT OF 250-300 MILLIBAR JET MAX TRAVERSING THE NORTHERN LAKES. REALLY CONCERNED THAT MISSOURI COMPLEX MAY STEAL OUR THUNDER BY DISRUPTING RETURN OOMPH OF LLJ THIS FAR NORTH. WILL HAVE TO WAIT AND SEE ON THIS. AFTER COLLABORATING WITH NEIGHBORS CONSENSUS IS TO HOLD ON TO THE WATCH. MODEL TRENDS NOT SUGGESTING TRAINING TYPE REDEVELOPMENT SHOULD IT OCCUR...BUT RATHER SCATTERED TYPE SHRA/TSRA...AND IT MAY ARRIVE VERY LATE. GIVEN THE HEAVY AMOUNT OF RAIN THAT HAS ALREADY FALLEN IN THE WATCH AREA WE WON/T NEED A TEXTBOOK FLASH FLOOD SETUP TO LEAD TO POSSIBLE ISSUES WITH FLOODING. SO WILL HANG ONTO THE WATCH FOR NOW...BUT GIVEN MODEL VARIATION WITH WHERE LATER DEVELOPMENT OCCURS CONFIDENCE IN CONVECTIVE TRENDS NOT THE GREATEST. MONDAY - CONFIDENCE...LOW TO MEDIUM SOME SUGGESTION THAT THE MORNING 850 JET PEELS OFF AND SETS UP A LULL IN CONVECTION WITH WEAK RIDGING. GFS AND ECMWF SHOW REDEVELOPMENT ACROSS THE CWA DURING THE AFTERNOON WHILE THE NAM AND GEM SHOW A DRIER LOOK. THE GFS IS SHOWING A FAIRLY SIGNIFICANT SURGE IN THE 850 JET DURING THE AFTERNOON WHILE OTHER MODELS SUGGEST FOCUS WILL BE FURTHER WEST. PLENTY OF MOISTURE AVAILABLE SO KEEPING THE FLASH FLOOD WATCH IN PLACE SEEMS THE BEST WAY TO GO AT THIS POINT. SHORT TERM...MONDAY NIGHT THROUGH WEDNESDAY. FORECAST CONFIDENCE LOW TO MEDIUM. WEAK RIDGING BETWEEN ONTARIO SHORT WAVE PUSHING TO THE EAST AND AHEAD OF NEXT SHORT WAVE CROSSING THE NORTHERN INTERMOUNTAIN REGION INTO THE NORTHERN PLAINS THAT REACHES WESTERN GREAT LAKES BY WEDNESDAY MORNING. COULD BE ONGOING CONVECTION MONDAY EVENING WITH 850 MB WAA/MOISTURE ADVECTION AND WEAK PERTURBATIONS/MCVS THAT ALL MODELS SHOW AT DIFFERING TIMES/STRENGTHS FROM MONDAY NIGHT INTO TUESDAY. GFS LOOKS OVERDONE WITH DEEP LAYER MESOLOW CROSSING CENTRAL WI DURING THE OVERNIGHT AND WILL BE IGNORED. BEST CHANCES FOR SEEING AN MCS IS WESTERN CWA AS IT MAY TRACK WITH LOW-LEVEL JET AS IT FOCUSES ON SW WI AS IT VEERS FROM SOUTH TO SOUTHWEST AROUND 06Z. LIKELY POPS IN THE WEST TAPERING TO CHANCE IN THE EAST. WHILE PW/S NOT AS ROBUST AS THE PAST FEW DAYS...STILL 1.3 INCHES TO 1.5 INCHES OR AROUND 135% OF NORMAL. WILL HAVE TO CONTINUE TO WATCH SATURATED WESTERN CWA FOR FLASH FLOODING POTENTIAL. WITH LEE SURFACE CYCLOGENESIS OVER THE PLAINS AHEAD OF SHORT WAVE TROUGH AND BROAD AREA OF HIGH PRESSURE OVER THE SE U.S. REGION REMAINS IN THE WARM SECTOR ON SOUTHEASTERN SIDE OF FAIRLY STATIONARY SURFACE TROUGH WITH A STEADY SSW FEED OF MOIST UNSTABLE AIR INTO THE REGION. NEXT LOW-LEVEL JET MAX APPROACHES TUE EVENING...WITH 12Z NAM TAKING DEAD AIM AT SRN WI WHILE GFS MORE SRLY AND FOCUSED ON MN/IA THEN VEERING TOWARD WI OVERNIGHT AND WEAKENING. WILL HAVE LIKELY POPS EVERYWHERE TUESDAY NIGHT...WITH CHANCE POPS WEDNESDAY AS TROUGH MOVES THROUGH. LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY. FORECAST CONFIDENCE MEDIUM. EVOLUTION FROM NEAR-ZONAL FLOW TO A MORE AMPLIFIED PATTERN BEGINS AS WEDNESDAY SHORT WAVE TROUGH IS FOLLOWED BY A DIGGING TROUGH THAT DROPS INTO THE UPPER GREAT LAKES. GFS MUCH DEEPER AND COLDER THAN ECMWF. STREAM OF VORTICITY MAXIMA THROUGH THE REGION KEEPS CHANCE POPS IN THE FORECAST DURING THIS TRANSITION. UPPER GREAT LAKES WILL BE IN NW FLOW BETWEEN THE DEEPENING ERN U.S. TROUGH AND A BROAD AMPLIFYING RIDGE OVER THE WEST BRINGING COOLER TEMPERATURES CLOSER TO NORMAL FOR THE END OF THE WEEK INTO THE WEEKEND. AVIATION/00Z TAFS/...LINE OF CONVECTION FROM EXTREME SRN WI INTO IL WILL SHIFT EAST OF THE TAF SITES LATE THIS AFTN. EXPECTING LATE NIGHT REDEVELOPMENT WITH 850 MILLIBAR JET BEING THE PRIMARY FOCUS. THIS ACTIVITY PROGGD TO AFFECT THE AREA INTO MONDAY MORNING WITH PERHAPS A LULL DEVELOPING LATE MORNING INTO EARLY AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR WIZ046-047-056-057- 062-063-067>069. LM...NONE. && $$ UPDATE...DAVIS TONIGHT/MONDAY AND AVIATION/MARINE...COLLAR MONDAY NIGHT THROUGH SUNDAY...REM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
627 PM CDT SUN JUN 23 2013 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND MONDAY ISSUED AT 252 PM CDT SUN JUN 23 2013 THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE WARM FRONT HAS MOVED THROUGH MOST OF WISCONSIN EXCEPT FOR FAR NORTHEAST WISCONSIN EARLY THIS AFTERNOON. SOME REMNANT STORMS FROM AN EARLIER LINE OF CONVECTION ARE MOVING ACROSS SOUTHERN WISCONSIN...BUT STARTING TO SEE SIGNS OF BEEFY CU DEVELOPING FARTHER NORTH FROM WAUSHARA COUNTY TO THE WESTERN UPPER PENINSULA. THIS IS IN A REGION OF BUILDING ML CAPES FROM 1000-1400 J/KG. STILL PLENTY OF TIME FOR FURTHER DESTABILIZATION TO OCCUR...WITH LIFT VIA SHORTWAVE OVER NORTHWEST WISCONSIN. AM STILL EXPECTING STORMS TO FIRE THOUGH IT MAY STILL HAVE A COUPLE HOURS TO GO. ACTUAL FRONT LIES ACROSS EASTERN MINNESOTA AND CLEARING SKIES ARE MOVING INTO SOUTHWEST MINNESOTA. IMPACTS FROM CONVECTION ARE THE MAIN FORECAST CONCERN IN THE SHORT TERM. TONIGHT..SHORTWAVE OVER NORTHWEST WISCONSIN WILL LIFT NORTHEAST AND CLEAR NORTHEAST WISCONSIN IN THE EVENING. FORCING ALONG THE TAIL OF THIS VORT AND FURTHER DESTABILIZATION SHOULD ALLOW SCT STORMS TO MOVE ACROSS NORTHEAST WISCONSIN IN THE EVENING. WINDS AT 700MB ARE PRETTY STRONG AT 45 TO 50 KTS...SO ANY STORMS WILL HAVE POTENTIAL AT CREATING DAMAGING WIND GUSTS AND SMALL HAIL. LOSS OF HEATING AND EXITING OF THE TAIL OF THE VORT SHOULD LET THE CONVECTION DIMINISH AND/OR EXIT BY MID TO LATE EVENING. ACTUAL SURFACE FRONT WILL DROP INTO NORTH-CENTRAL WISCONSIN AFTER MIDNIGHT. CONVERGENCE ALONG THE FRONT IS VERY WEAK AND THERE IS NO SUPPORT ALOFT...SO COULD SEE SOME LOW CLOUDS ALONG THE FRONT...MUCH NOT MUCH ELSE. WILL END POPS FROM NW TO SE AFTER MIDNIGHT. MUGGY LOWS IN THE MID TO UPPER 60S. MONDAY...SURFACE FRONT WILL STALL ACROSS NORTHERN WISCONSIN IN THE MORNING. PROGGED SOUNDINGS AND UPSTREAM SATELLITE IMAGERY SHOW PLENTY OF DRY AIR THROUGH THE COLUMN AND PARTLY TO MOSTLY CLEAR SKIES. NO CLEAR TRIGGERS UPSTREAM EITHER SO WILL GO WITH A DRY BUT PARTLY CLOUDY START TO THE DAY. COME AFTERNOON...AN 86/69 PARCEL OVER THE FOX VALLEY WILL RESULT IN 3000 J/KG OF ML CAPE AND VERY LITTLE CIN. CONVECTIVE TEMPS ARE IN THE LOW 90S AND DO NOT SEE A TRIGGER...BUT PERHAPS THE LAKE BREEZE CAN CREATE THE NECESSARY CONVERGENCE FOR A STORM OR TWO TO POP. WILL KEEP A SLIGHT CHANCE OF A STORM OVER CENTRAL AND NORTHEAST WISCONSIN WHERE INSTABILITY IS MAXIMIZED. HIGHS MAINLY IN THE MID 80S. .LONG TERM...MONDAY NIGHT THROUGH SUNDAY ISSUED AT 252 PM CDT SUN JUN 23 2013 MEDIUM RANGE MODELS ARE IN GREATER DISAGREEMENT THAN THE LAST FEW DAYS...ESPECIALLY WITH A POSSIBLE CONVECTIVE COMPLEX LATE MONDAY NIGHT OR TUESDAY AND AGAIN WEDNESDAY NIGHT WITH THE POSSIBLE FORMATION OF A CLOSED LOW OVER WISCONSIN OR UPPER MICHIGAN. AS FAR AS LATE MONDAY NIGHT AND TUESDAY GOES IT LOOKS LIKE THE GFS IS EXHIBITING SOME SORT OF CONVECTIVE FEEDBACK PRODUCING A CLOSED UPPER LOW THAT MOVES ACROSS MINNESOTA AND WISCONSIN PRODUCING CONSIDERABLE CONVECTION. THIS IS LIKELY OVERDONE AND PREFER THE FLATTER AND SLOWER UPPER SYSTEM THAT SHOULD BRING SHOWERS AND THUNDERSTORMS TUESDAY AFTERNOON AND EVENING. THE GFS ALSO FORECASTS A CLOSED UPPER LOW WEDNESDAY NIGHT AND THURSDAY OVER THE WESTERN GREAT LAKES WHICH SEEMS OVERDONE CONSIDERING THE CURRENT PATTERN. CANNOT TOTALLY DISCOUNT THE GFS AS IT HAS SOME SUPPORT FROM THE NAM BUT THE ECMWF IS MUCH FASTER AND WEAKER. WARM AND HUMID WEATHER EXPECTED THROUGH THURSDAY. AFTER THURSDAY THE MODELS DO AGREE THAT AN UPPER RIDGE WILL DEVELOP OVER THE WESTERN UNITED STATES WITH CYCLONIC NORTHWEST FLOW OVER WISCONSIN. THIS SHOULD BRING COOLER AND DRIER AIR TO THE REGION BY FRIDAY AND SATURDAY. WHILE IT SHOULD BE GENERALLY DRY FRIDAY AND SATURDAY THERE COULD BE SCATTERED DIURNAL SHOWERS WITH COLD TEMPERATURES ALOFT. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 617 PM CDT SUN JUN 23 2013 HARD TO UNDERSTAND WHY STORMS HAVE NOT DEVELOPED THIS AFTERNOON...WITH PLENTY OF MOISTURE/INSTABILITY AND CONVERGENCE OVER NE/EC WI. GIVEN THE CURRENT TRENDS...WILL ONLY CARRY A VCTS AT THE GRB TAF SITE FOR AN HOUR...OTHERWISE DRY. GIVEN THAT THE LOW-LEVEL JET IS EXPECTED TO WEAKEN AND VEER TO A WESTERLY DIRECTION...CONFIDENCE IN TSTMS IS TOO LOW TO MENTION FOR THE REST OF THE TAF PERIOD. BEST ESTIMATE RIGHT NOW IS THAT SOME CONVECTION WILL FIRE MONDAY NIGHT...AS A WEAK UPPER DISTURBANCE TRACKS THROUGH THE AREA AND A SOUTHWESTERLY LOW-LEVEL JET REDEVELOPS. MAIN AVIATION CONCERN FOR THIS TAF PERIOD WOULD APPEAR TO BE FOG POTENTIAL LATE TONIGHT...ALTHOUGH WILL ONLY MENTION MVFR VSBYS...EXPECT AT RHI WHERE SOME IFR CONDITIONS MAY OCCUR. HAVE REMOVED THE MENTION OF LLWS THIS EVENING...AS EARLY DATA FROM THE GRB RAOB ONLY SHOWED WINDS AROUND 25 KTS JUST OFF THE SURFACE. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......RDM AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
358 PM CDT SAT JUN 22 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 253 PM CDT SAT JUN 22 2013 AT 3 PM...A WARM FRONT WAS LOCATED NEAR THE INTERSTATE 94 CORRIDOR AND AN OUTFLOW BOUNDARY OVER NORTHERN IOWA. AS THE TEMPERATURES RISE ABOVE THE CONVECTIVE TEMPERATURES /LOWER 80S/ LATE THIS AFTERNOON...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP ALONG AND SOUTH OF THE INTERSTATE 94 CORRIDOR. IN ADDITION... EXPECT THE SYSTEM MOVING OUT OF NORTHWEST IOWA TO GRADUALLY UPSCALE AS IT MOVES INTO BETTER CAPES AND MOISTURE TRANSPORT. WITH 0-3 KM SHEAR GREATER THAN 40 KNOTS...THINKING THAT THE STORMS BECOME MORE COLD POOL DOMINATED THAT THERE WILL ONCE AGAIN BE THE POTENTIAL FOR SOME BOW ECHOS TO DEVELOP LATE THIS AFTERNOON AND EVENING. IN ADDITION...WITH 1000 TO 1200 J/KG DCAPES THERE WILL BE THE POTENTIAL FOR DAMAGING WET MICROBURSTS. WITH PRECIPITABLE WATER VALUES RUNNING BETWEEN 1.8 AND 2.0 INCHES AND WARM CLOUDS DEPTHS BETWEEN 4 AND 4.5 KM...EXPECT THE THUNDERSTORMS TO BE VERY EFFECTIVE RAIN PRODUCERS. HOWEVER IT LOOKS LIKE THEY WILL BE PROGRESSIVELY MOVING WHICH WILL LIMIT THE THREAT FOR WIDESPREAD FLASH FLOODING. HOWEVER WITH THIS SAID...WILL STILL HAVE TO WATCH URBANIZED AREAS WHERE JUST AN INCH OF RAIN AN HOUR CAN RESULT IN SOME LOCALIZED FLASH FLOODING. FOR OVERNIGHT...THE 23.12Z DETERMINISTIC MODELS CONTINUE TO SHOW THAT MUCH OF THE PRECIPITATION FOR THIS TIME PERIOD WILL BE MAINLY NORTH OF THE INTERSTATE 90 CORRIDOR. THEY HAVE SHOWED THIS FOR THE PAST 6 MODEL CYCLES. THIS IS IN RESPONSE TO THE TROUGH CURRENTLY OVER NEBRASKA MOVING NORTHEAST AWAY FROM THE FORECAST AREA. AS THIS OCCURS...THE NOSE OF THE 850 MB MOISTURE TRANSPORT WILL PUSH NORTH INTO NORTHERN WISCONSIN. IN THE WAKE OF THIS TROUGH...THE PRECIPITABLE WATER VALUES DROP TO 1.2 TO 1.4 INCHES...AND THE WARM CLOUD LAYER DEPTHS FALL INTO THE 3.5 TO 4 KM RANGE. THIS IS IDEA THAT THE PRECIPITATION COULD BEGIN WANING OVERNIGHT IS SUPPORTED BY THE LAST 2 RUNS OF THE HRRR WHICH SHOWS A BAND OF SHOWERS AND THUNDERSTORMS PROGRESSIVELY MOVING NORTHEAST THROUGH CLARK AND TAYLOR COUNTIES IN NORTH CENTRAL WISCONSIN BETWEEN 23.07Z AND 23.09Z. FOR SUNDAY AFTERNOON...EXPECT THE UPPER LEVEL TROUGH WHICH HAS BEEN POSITIONED TO OUR WEST OVER THE LAST SEVERAL DAYS TO MOVE INTO THE WESTERN PORTIONS OF THE FORECAST AREA. WHILE THE 850 MB MOISTURE TRANSPORT IS NOT THAT IMPRESSIVE. PRECIPITABLE WATER VALUES DO CLIMB TO AROUND 1.8 INCHES...WARM CLOUD LAYER DEPTHS CLIMB ABOVE 4 KM...AND CORFIDI VECTORS SUGGEST TRAINING ALONG AND AHEAD OF THE COLD FRONT. AS A RESULT...WILL HAVE TO WATCH FOR THE POTENTIAL FOR SOME FLOODING. CERTAINTY ON THE SPEED AND LOCATION OF THIS FRONT WAS NOT HIGH ENOUGH TO GO WITH A FLASH FLOOD WATCH AT THIS TIME. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 253 PM CDT SAT JUN 22 2013 ON SUNDAY NIGHT AND MONDAY...THE MODELS CONTINUE TO SHOW THAT A SHORT WAVE TROUGH WILL MOVE ACROSS WESTERN AND NORTHERN MINNESOTA. AS THIS OCCURS...EXPECT A COLD FRONT TO MOVE THROUGH THE REGION. THIS FRONT WILL BE THE FOCUS FOR ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY. IT MAY MOVE FAR ENOUGH EAST TO ALLOW SOME DRYING ON MONDAY AFTERNOON. FROM MONDAY NIGHT THROUGH WEDNESDAY...THE MODELS CONTINUE TO SHOW THAT A STATIONARY FRONT WILL LINGER ACROSS THE AREA. WHILE THE MODELS HAVE CONSISTENTLY SHOWED THIS...THEY CONTINUE TO STRUGGLE ON THE LOCATION AND TIMING OF THUNDERSTORM COMPLEXES WHICH MOVE THROUGH THE REGION...SO JUST WENT WITH THE ALL BLEND TEMPERATURES AND PRECIPITATION CHANCES. FOR THE REMAINDER OF THIS TIME PERIOD...IT CONTINUES TO LOOK LIKE THE UPPER LEVEL RIDGE WILL RETROGRADE WEST INTO THE WESTERN UNITED STATES. THIS WOULD PLACE THE AREA UNDER NORTHWEST FLOW ALOFT. AS A RESULT...EXPECT NEAR TO SLIGHTLY BELOW-NORMAL TEMPERATURES. PRECIPITATION CHANCES ARE NOT CLEAR AS THERE WILL THE POTENTIAL FOR SHORT WAVE TROUGHS TO MOVE SOUTHEAST THROUGH THE AREA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1248 PM CDT SAT JUN 22 2013 EXPECTING SCATTERED THUNDERSTORMS TO FIRE THIS AFTERNOON ALONG A WARM FRONT SITUATED ALONG THE IA/MN BORDER. PLAN ON THE BULK OF THIS THUNDERSTORM ACTIVITY TO EXTEND FROM KFSD THROUGH SOUTH-CENTRAL MN...WITH EASTERN FRINGES OF THIS CONVECTION REACHING TOWARD THE MISSISSIPPI RIVER INCLUDING KRST/KLSE TAF SITES. THE WARM FRONT IS EXPECTED TO PUSH NORTH OF THE AREA AFTER MIDNIGHT...TAKING THE THUNDERSTORM ACTIVITY WITH IT. BOTTOM LINE...INCLUDED VCTS BKN030-035CB IN THE KRST/KLSE TAFS FROM 21Z THROUGH 06Z. OTHER THAN SOME 6SM BR IN THE 08-13Z TIME FRAME...EXPECTING VFR CONDITIONS THEN TO PREVAIL THROUGH 18Z SUNDAY. SHRA/TS LOOKING LIKELY AGAIN SUNDAY AFTERNOON/EVENING AS A COLD FRONT PUSHES EAST OUT OF THE NORTHERN PLAINS TOWARD THE AREA. && .HYDROLOGY... ISSUED AT 253 PM CDT SAT JUN 22 2013 HYDRO CONCERNS LINGER ACROSS TURKEY...UPPER IOWA...SOUTHERN HALF OF THE KICKAPOO...BLACK...AND TURTLE CREEK. IN ADDITION...THE SMALL STREAMS ACROSS ALLAMAKEE AND CLAYTON COUNTIES IN NORTHEAST IOWA... AND CRAWFORD AND GRANT COUNTIES IN SOUTHWEST WISCONSIN. FORTUNATELY IT LOOKS LIKE THE HEAVIEST RAIN POTENTIAL FOR TONIGHT WILL BE MAINLY NORTH OF MOST OF THESE BASINS. HOWEVER THERE IS CONCERN ON SUNDAY THAT THERE COULD BE ANOTHER ROUND OF HEAVY RAIN THAT COULD AFFECT THE AREA ON SUNDAY AFTERNOON AND NIGHT. HOWEVER DUE TO THE UNCERTAINTY ON THE SPEED OF THIS SYSTEM...RAINFALL AMOUNTS ARE NOT CLEAR. IN ADDITION TO THE SHORT TERM WATER CONCERNS...THERE IS A RIVER FLOOD WATCH FOR THE MISSISSIPPI AT WABASHA...WINONA...AND LA CROSSE. THESE RIVERS ARE EXPECTED TO GO ABOVE FLOOD STAGE UNTIL AFTER JULY 1ST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...DAS HYDROLOGY...BOYNE
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND SUNDAY ISSUED AT 246 PM CDT SAT JUN 22 2013 THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COMPLICATED WEATHER MAP THIS AFTERNOON ACROSS THE REGION. OUTFLOW BOUNDARY FROM LAST NIGHTS STORMS REACHED INTO CENTRAL ILLINOIS AND CENTRAL IOWA...BUT IS NOW RETURNING NORTHWARD INTO SOUTHERN MINNESOTA. MEANWHILE...HIGH PRESSURE OVER ONTARIO IS PUSHING A WEAK CANADIAN FRONT INTO CENTRAL WISCONSIN AND CENTRAL MINNESOTA. LOOKING ALOFT...VARIOUS SHORTWAVE TROUGHS ARE PROGRESSING NORTHEAST OVER THE NORTHERN MISSISSIPPI VALLEY AND THE UPPER PENINSULA. RADAR IS PRETTY QUIET ACROSS THE REGION SO FAR THIS AFTERNOON...BUT THE ATMOSPHERE IS STILL RECOVERING FROM LAST NIGHTS CONVECTION. INSTABILITY IS BEGINNING TO BUILD OVER SOUTHERN MINNESOTA IN CLOSE PROXIMITY TO THE RETURNING OUTFLOW BOUNDARY. LOW LEVEL CONVERGENCE IS MAXIMIZED HERE...SO THIS BOUNDARY LOOKS TO BE THE FOCUS FOR THE REST OF THE AFTERNOON AND HEADING INTO THE EVENING. OBVIOUSLY...IMPACTS FROM POSSIBLE CONVECTION IS THE MAIN FORECAST CONCERN IN THE SHORT TERM. TONIGHT...THE LLJ WILL DEVELOP AGAIN AHEAD OF SHORTWAVE TROUGHS EXTENDING FROM THE CENTRAL GREAT PLAINS TO LAKE SUPERIOR. NAM/RUC/GFS SUGGEST MASS CONVERGENCE ALONG THE NOSE OF THE LLJ WILL TAKE PLACE ACROSS CENTRAL OR SOUTHERN MINNESOTA...AND INTO WESTERN WISCONSIN WHERE THE RETURNING OUTFLOW BOUNDARY/WARM FRONT WILL RESIDE. AS INCREASING FLOW LIFTS OVER THIS BOUNDARY IN CONJUNCTION WITH ELEVATED INSTABILITY OF 1000-2000 J/KG...ANTICIPATE ANOTHER MCS TO DEVELOP OVER CENTRAL OR SOUTHERN MINNESOTA THIS EVENING BEFORE TRACKING EAST ALONG THE BOUNDARY. THINK INSTABILITY WILL HAVE RECOVERED ENOUGH BY THIS EVENING FOR ANY CONVECTION TO REACH CENTRAL WISCONSIN OR EVEN THE FOX VALLEY BEFORE IT TURNS TO THE SOUTHEAST LATE TONIGHT. LATEST MODELS ARE GENERALLY ALL OVER THE PLACE WITH PRECIP TRENDS...SO CONFIDENCE IS RATHER LOW. BUT THE FRONT HAS BEEN ACTIVE WITH MCS/S THE PAST SEVERAL NIGHTS...SO AS LONG AS INSTABILITY DEVELOPS ALONG THE BOUNDARY THIS AFTERNOON...CANNOT RULE OUT THE POSSIBILITY OF AN MCS DEVELOPING THIS EVENING. BIGGEST THREAT WOULD BE HEAVY RAINFALL/FLOODING...BUT STRONG STRAIGHT LINE WINDS AND SMALL HAIL COULD ALSO OCCUR IF INSTABILITY RECOVERS ENOUGH. LOWS MAINLY IN THE 60S. SUNDAY...MUCH OF THE DETAILS REVOLVE AROUND WHAT HAPPENS TONIGHT...AND IF CONVECTION CAN LAY OUT ANOTHER OUTFLOW BOUNDARY WHICH KEEPS THE REGION STABLE FOR MUCH OF THE DAY. IF THIS OCCURS...MUCH OF THE MORNING INTO EARLY AFTERNOON MAY TURN OUT TO BE DRY. DURING THE AFTERNOON THOUGH...A SHORTWAVE TROUGH MOVING INTO NORTHWEST WISCONSIN WILL HELP SOUTHERLY FLOW STRENGTHEN AND PUSH INSTABILITY NORTHWARD. REALLY TOUGH TO SAY HOW MUCH INSTABILITY WILL BE PRESENT...DUE TO UNCERTAINTIES IN HEATING...AND ALSO PROGGED SOUNDINGS APPEAR TO BE CONVECTIVELY ADJUSTED. BUT WITH WIND FIELDS STRENGTHENING TOMORROW...FAIRLY UNIDIRECTIONAL SHEAR CALLS FOR DAMAGING WINDS AND LARGE HAIL AS THE MAIN THREATS. CENTRAL AND NORTH-CENTRAL WISCONSIN SHOULD HAVE THE BEST CHANCE OF STORMS TOMORROW AFTERNOON AND WILL KEEP THE HIGHEST POPS OVER THERE. WITH SOUTHERLY WINDS...TEMPS SHOULD REACH MOSTLY IN THE MID TO UPPER 80S...PERHAPS A LITTLE LOWER OVER N-C WISCONSIN. .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY ISSUED AT 246 PM CDT SAT JUN 22 2013 SOUTHWEST UPPER FLOW AND SEVERAL WEAK FRONTAL BOUNDARIES WILL KEEP THE THREAT OF PRECIPITATION IN THE FORECAST THROUGH THE MIDDLE OF THE WEEK. A WEAK COLD FRONT WILL MOVE THROUGH SUNDAY NIGHT AND SHOULD BE ACCOMPANIED WITH SHOWERS AND THUNDERSTORMS. THERE COULD BE A BREAK IN THE ACTION MONDAY BEFORE THE FRONT LIFTS SLOWLY NORTH AND PERHAPS STALL OVER THE FORECAST AREA TUESDAY AND WEDNESDAY. A MORE SIGNIFICANT COLD FRONT SHOULD MOVE THROUGH THURSDAY AND BE FOLLOWED BY DRY AND PLEASANT WEATHER FOR THE END OF THE WEEK. THERE ARE THREATS OF SEVERE THUNDERSTORMS MONDAY THROUGH WEDNESDAY AFTERNOONS WITH HIGH CAPES AND MODERATE MID LEVEL WINDS. HIGH PRECIPITABLE WATER VALUES AND SLOW MOVING STORMS ALSO COULD PRODUCE EXCESSIVE RAINS. WILL MENTION IN THE HAZARDOUS WEATHER OUTLOOK. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1236 PM CDT SAT JUN 22 2013 CONFIDENCE HAS NOT IMPROVED ANY IN THE FORECAST DETAILS OVER THE NEXT 24 HOURS. PARTIAL CLEARING OCCURRING IN THE VICINITY OF VARIOUS SHORTWAVE TROUGHS OVER MINNESOTA AND WESTERN WISCONSIN SUGGESTS POTENTIAL FOR STORMS WILL INCREASE LATER THIS AFTERNOON IF THESE TRENDS CONTINUE. IF STORMS DEVELOP...WOULD LIKELY IMPACT CENTRAL AND NORTH-CENTRAL WISCONSIN. NOCTURNAL STORMS COULD ALSO REFIRE ALONG A WARM FRONT AS IT LIFTS NORTH OVER MINNESOTA AND WISCONSIN TONIGHT. IF THIS OCCURS...STORMS WOULD TRACK ALONG THE WARM FRONT EAST-SOUTHEAST INTO NORTH-CENTRAL WISCONSIN AND POSSIBLY NORTHEAST WISCONSIN LATE. UNCERTAINTIES REVOLVING AROUND LOCATION AND TIMING OF STORMS IS TOO HIGH TO INCLUDE TSRA IN TAFS AT THIS TIME. OTHERWISE...CIGS IMPROVING THIS AFTERNOON TO VFR. && .MARINE...DENSE FOG IS THE PRIMARY CONCERN OVER LAKE MICHIGAN AS WARM AND MOOIST AIR FLOWS NORTH OVER THE COLDER WATERS. DENSE FOG WILL PROBABLY FORM TONIGHT ALONG THE LAKESHORE SOUTH OF STURGEON BAY AND WILL LIKELY EXPAND NORTHWARD TONIGHT AND SUNDAY. THERE MAY BE SOME DISSIPATION OF THE FOG SUNDAY AFTERNOON WHEN THE WIND PICKS UP. THERE MAY BE PERIODS OF DENSE FOG THROUGH WEDNESDAY WITH A POSSIBLE BREAK MONDAY AND MONDAY NIGHT. .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......RDM AVIATION.......MPC MARINE.........RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1249 PM CDT SAT JUN 22 2013 .UPDATE... ISSUED AT 1248 PM CDT SAT JUN 22 2013 CURRENTLY WATCHING A WARM FRONT ALONG THE MN/IA WARM FRONT FOR THUNDERSTORM DEVELOPMENT THIS AFTERNOON. RAP PRODUCES 5000-5500J/KG OF 0-1KM ML MUCAPE ALONG THIS WARM FRONT WITH INCREASING MOISTURE TRANSPORT/HEATING. ALSO...SIGNIFICANT 0-6KM BULK SHEAR OF 35-40KT DEPICTED ALONG/NORTH OF THE FRONT. THINKING THAT WITH HEATING AND WARM FRONTAL BOUNDARY MAKING A MOVE NORTH...CONVECTION WILL FIRE ALONG THE FRONT WITH MOST NUMEROUS SHRA/TS ACTIVITY FROM KFSD AND ALONG THE MN/IA BORDER...WITH EASTERN FRINGES OF THIS CONVECTION GETTING INTO NORTHEAST IA/SOUTHEAST MN LATE IN THE AFTERNOON. OF NOTE IS STRONG 0-1 MLCIN IN PLACE RIGHT NOW. FEEL THIS WILL EVENTUALLY ERODE THOUGH AS CIRRUS SHIELD FROM THIS MORNING/S STORMS DISSOLVES AND SURFACE HEATING GETS GOING. GIVEN THE ABOVE SIGNALS...POTENTIAL IS THERE FOR DISCRETE SUPERCELLS WITH LARGE HAIL/WIND/ISOLATED TORNADO THREAT MAINLY FOR PORTIONS OF SOUTHEAST MN/NORTHEAST IA. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 349 AM CDT SAT JUN 22 2013 MAIN FORECAST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES...HEAVY RAIN AND SEVERE THREATS THRU THE PERIOD...TEMPERATURES. DATA ANALYSIS AT 06Z HAD LOW PRESSURE OVER EASTERN CO WITH A TROUGH TO THE NORTHEAST INTO THE UPPER MIDWEST. SEVERAL WEAKER WAVES OF LOW PRESSURE ALONG THIS TROUGH/FRONT INTO WI/MI. TROUGH AND OLD OUTFLOW BOUNDARIES REMAIN THE FOCUS FOR SHRA/TSRA DEVELOPMENT AGAIN EARLY THIS MORNING AS THE LOW LEVEL JET AND MOISTURE TRANSPORT PUSH AN AIRMASS WITH 1.5 TO 2 INCH PW/S NORTH/NORTHEAST INTO IA/MN/WI. RATHER MASSIVE CONVECTIVE COMPLEX EARLY THIS MORNING FROM SOUTHERN LK MI TO SOUTHERN MN AND EASTERN NEB...AROUND THE EDGE OF THE STRONGER MID LEVEL CAPPING. UNDER THE CAPPING...EARLY MORNING TEMPS IN THE MID 70S TO NEAR 80 ACROSS MUCH OF IA. 22.00Z MODELS LOOK TO HAVE INITIALIZED WELL...THOUGH NOT AS SIMILARLY AS ONE WOULD LIKE. AS EXPECTED IN A FORECAST DOMINATED BY MESO-SCALE FORCINGS AND CONVECTION ACROSS THE REGION...SOLUTIONS OFFERING A VARIETY OF SENSIBLE WEATHER OUTCOMES FOR THE NEXT FEW DAYS. DPROG/DT OF 500MB HGTS AT 22.00Z SHOWED THE MODEL RUNS OF 20.00Z AND 21.00Z VERIFIED QUITE WELL WITH THE LARGER SCALE FEATURES OVER NOAM/EASTERN PAC. MOST OF THE EARLIER RUNS WERE A BIT WEAK WITH SHORTWAVE FEATURES OVER THE CENTRAL CONUS TO GREAT LAKES AND WERE A BIT HIGH WITH 500MB HGTS OVER THE UPPER MIDWEST. MODELS TRENDING TOWARD A TIGHTER CONSENSUS TODAY THRU SUN...AT LEAST WITH THE NORTHERN ROCKIES TROUGH AS IT LIFTS INTO THE NORTHERN PLAINS. TREND IS A BIT STRONGER WITH TROUGHING AS IT LIFTS ACROSS THE NORTHERN PLAINS TOWARD NORTHERN MN/WESTERN ONT TONIGHT/SUN. PLENTY OF DETAIL DIFFERENCES WITH SMALLER SCALE FEATURES THRU THE SOUTHWEST FLOW ACROSS THE CENTRAL PLAINS INTO UPPER MIDWEST AHEAD OF THE TROUGH. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED MODELS TO BE REASONABLE WITH THE SFC MASS FIELDS OVER THE CENTRAL CONUS...BUT SFC PRESSURE FIELDS QUITE DISTURBED FROM EASTERN NEB TO WI BY ALL THE ONGOING CONVECTION. PER WV IMAGERY...ECMWF LOOKS BEST WITH THE CENTRAL CONUS SHORTWAVE DETAILS. MOST OF THE OTHERS LOOK TO SUFFER SOME FORM OF CONVECTIVE FEEDBACK WITH COMPACT/STRONG VORTICITY MAXIMA OVER THE NORTHERN PLAINS/UPPER MIDWEST. ECMWF/GEM/SREF LOOKED BETTER WITH THE 00-06Z PRECIP OVER THE UPPER MIDWEST...NAM/GFS WERE TOO FAR SOUTH WITH CONVECTION OVER IA. LOCAL/REGIONAL WRF MODELS CATCHING ONTO CONVECTIVE EVOLUTION EARLY THIS MORNING. FIRST TO CATCH IT WERE THE ARX-WRF AND EAST-ARW. GIVEN THE MODEL DIFFERENCES AND THEIR IMPACTS ON THE SENSIBLE WEATHER THRU THE WEEKEND...SHORT TERM FCST CONFIDENCE IS BELOW AVERAGE. GENERALLY FAVORED A MODEL/ENSEMBLE CONSENSUS...WEIGHTED TOWARD THE NON GFS/NAM MODELS. FAVORING THE SUITE OF LOCAL/REGIONAL HIGH-RES WRF MODELS...CONVECTION WILL BE ONGOING ACROSS AT LEAST PORTIONS OF THE AREA THIS MORNING AS THE LOW LEVEL JET/MOISTURE TRANSPORT/THETA-E CONVERGENCE VEERS ACROSS MN/IA/WI. TRENDED SHRA/TSRA CHANCES TOWARD 70-80 PERCENT ACROSS MUCH OF THE FCST AREA AT 12Z...THEN TRENDING DOWNWARD THRU THE MORNING. ONLY CARRIED 20-40 PERCENT SHRA/TSRA CHANCES ACROSS MAINLY THE NORTHWEST/NORTH PARTS OF THE FCST AREA THIS AFTERNOON...CLOSER TO THE MAIN TROUGH/FRONTAL BOUNDARY AND THE MID LEVEL WARMING/CAPPING BUILDING OVER THE SOUTHEAST HALF OF THE FCST AREA. WITH WHAT LOOKS TO BE A BREAK LATER THIS MORNING/AFTERNOON...WILL NOT EXTEND FLASH FLOOD WATCH BEYOND ITS CURRENT 17Z END TIME. MOISTURE TRANSPORT INCREASES INTO THE AREA AGAIN THIS AFTERNOON WITH 2K-3K J/KG OF CAPE AND SOUNDINGS SHOWING MINIMAL CAPPING...WILL LEAVE A 20-40 PERCENT SHRA/TSRA CHANCE THRU THE AFTERNOON. GIVEN THE /FAT/ CAPES... STORMS THIS AFTERNOON/EARLY THIS EVENING WOULD POSE A THREAT OF LARGE HAIL. APPEARS AREA MAY GET MORE OF A BREAK FROM THE WIDESPREAD CONVECTION TONIGHT/EARLY SUN AS THE MAIN TROUGH/FRONT WITH ITS CONVERGENCE/LIFT MOVE NORTH OF THE AREA. LEFT SHRA/TSRA CHANCES TONIGHT MAINLY IN THE 20-40 PERCENT RANGE. DAY CREW WILL HAVE TO RE- EVALUATE THE HYDRO SITUATION...WATCH TRENDS THRU THE DAY AND SEE WHICH IF ANY OF THE MODELS ARE MORE CORRECT WITH CONVECTIVE EVOLUTION THE NEXT 24-36HRS. BY SUN AFTERNOON THE MAIN MID LEVEL TROUGH LIFTING INTO NORTHWEST MN PUSHES THE SFC-850MB FRONT/TROUGH BACK TO THE SOUTHEAST. FORCING/ LIFT AHEAD OF THIS FEATURE PUSHING INTO THE AIRMASS OVER THE AREA WITH SOME 2K-3K J/KG MU CAPE AND PW VALUES OF 1.5 TO 2 INCHES SHOULD IGNITE ANOTHER ROUND OF SHRA/TSRA WITH HEAVY RAIN AND SEVERE POTENTIAL. GIVEN THE RECENT RAINS APPEARS ANOTHER FLASH FLOOD WATCH MAY BE NEEDED SUN AFTERNOON/EVENING. HIGH TEMPERATURES TODAY/SUN REMAIN TRICKY...BASED ON WHEN CONVECTION WOULD CLEAR THE AREA AND HOW QUICKLY CLOUDS THIN/CLEAR AND ALLOW FOR SOME SUNSHINE. GIVEN THE UNCERTAINTIES...STAYED NEAR THE MODEL/ ENSEMBLE CONSENSUS FOR HIGHS/LOWS TODAY THRU SUN. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 349 AM CDT SAT JUN 22 2013 MODEL CONSENSUS CONTINUES TO IMPROVE FOR SUN NIGHT THRU MON NIGHT AS THE MID LEVEL TROUGH LIFTS INTO ONT AND HGTS RISE OVER THE REGION. HOWEVER THE LOWER LEVEL PATTERN REMAINS ACTIVE/UNSETTLED...WITH PLENTY OF MODEL DETAIL DIFFERENCES. FCST CONFIDENCE IN THIS PERIOD REMAINS BELOW AVERAGE. THE PASSING MID LEVEL TROUGH PUSHES THE WEAK SFC TROUGH/FRONT INTO ACROSS THE AREA SUN NIGHT. SHRA/TSRA CHANCES IN THE 50-70 PERCENT RANGE SUN NIGHT LOOK REASONABLE. GIVEN THE FORCING...STRONG INSTABILITY AND INCREASED WINDS/SHEAR ALOFT...TSRA SUN NIGHT COULD BE SEVERE WITH THREATS OF WINDS AND HAIL. THE TROUGH/FRONT FROM SUN/AFTERNOON/EVENING LIFTS BACK NORTH ALREADY ON ON MON...PROVIDING FOCUS FOR CONVERGENCE/LIFT AND SHRA/TSRA FORMATION...THIS AS MODELS SHOW POTENTIAL FOR ONE OR MORE SHORTWAVES TO BE RIPPLING THRU THE FLOW AND ACROSS THE REGION. CONTINUED 20-40 PERCENT SHRA/TSRA CHANCES MON. LOW LEVEL JET/MOISTURE TRANSPORT/ THETA-E CONVERGENCE INCREASE INTO THE AREA MON NIGHT AS THIS BOUNDARY LIFTS NORTH ACROSS THE AREA. CARRIED 30-50 PERCENT SHRA/TSRA CHANCES MON NIGHT. GIVEN THE LOWER CONFIDENCE ON THE CONVECTIVE DETAILS...USED A MODEL/ENSEMBLE CONSENSUS FOR LOWS/HIGHS SUN NIGHT THRU MON NIGHT. WITH ALL THE SHORT TERM CONCERNS AND UNCERTAINTIES...NOT MUCH TIME SPENT LOOKING AT THE DAY 4-7 PERIOD. MEDIUM RANGE MODEL RUNS OF 22.00Z DO OFFER SOME CONSENSUS FOR A FLAT WEST TO SOUTHWEST FLOW ALOFT OVER THE CENTRAL CONUS TUE/WED...WITH SHORTWAVES TO BE RIPPLING THRU THIS FLOW AND ACROSS THE REGION. LONGER TERM FCST CONFIDENCE AVERAGE. WITH THE MOIST/UNSTABLE AIRMASS IN PLACE AND ONE OR MORE BOUNDARIES FLOATING AROUND THE REGION...SHRA/TSRA CHANCES LOOK TO CONTINUE TUE THRU AT LEAST WED NIGHT. BY THU MODELS POINT TO RIDGING BUILDING OVER THE WESTERN CONUS AND THE FLOW ALOFT OVER THE UPPER MIDWEST BECOMING NORTHWEST FOR THU/FRI. THIS NORTHWEST FLOW WOULD DRIVE SOME DRIER/COOLER AIR FROM SOUTH CENTRAL CAN/NORTHERN PLAINS...AND DECREASING SHRA/TSRA CHANCES...INTO THE AREA FOR THE LATER PARTS OF THE WEEK. MODEL/ENSEMBLE CONSENSUS HIGHS/LOWS FOR TUE THRU FRI LOOK WELL TRENDED FOR NOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1248 PM CDT SAT JUN 22 2013 EXPECTING SCATTERED THUNDERSTORMS TO FIRE THIS AFTERNOON ALONG A WARM FRONT SITUATED ALONG THE IA/MN BORDER. PLAN ON THE BULK OF THIS THUNDERSTORM ACTIVITY TO EXTEND FROM KFSD THROUGH SOUTH-CENTRAL MN...WITH EASTERN FRINGES OF THIS CONVECTION REACHING TOWARD THE MISSISSIPPI RIVER INCLUDING KRST/KLSE TAF SITES. THE WARM FRONT IS EXPECTED TO PUSH NORTH OF THE AREA AFTER MIDNIGHT...TAKING THE THUNDERSTORM ACTIVITY WITH IT. BOTTOM LINE...INCLUDED VCTS BKN030-035CB IN THE KRST/KLSE TAFS FROM 21Z THROUGH 06Z. OTHER THAN SOME 6SM BR IN THE 08-13Z TIME FRAME...EXPECTING VFR CONDITIONS THEN TO PREVAIL THROUGH 18Z SUNDAY. SHRA/TS LOOKING LIKELY AGAIN SUNDAY AFTERNOON/EVENING AS A COLD FRONT PUSHES EAST OUT OF THE NORTHERN PLAINS TOWARD THE AREA. && .HYDROLOGY...TONIGHT INTO SATURDAY ISSUED AT 349 AM CDT SAT JUN 22 2013 A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH NOON TODAY. CONVECTION SHOULD BE WANING/ENDING THRU THE MORNING...WITH PLENTY OF UNCERTAINTY CONCERNING REDEVELOPMENT AND EVOLUTION THIS AFTERNOON AND EVENING. HEAVY RAINS FROM FRI EVENING/EARLY THIS MORNING WERE NOT AS WIDESPREAD AS THE NIGHT BEFORE. CONVECTION THIS AFTERNOON/ EVENING APPEARS AS THOUGH IT MAY BE MORE SCATTERED AND PROGRESSIVE THUS WILL NOT BE EXTENDING THE FLASH FLOOD WATCH AT THIS TIME. MAIN FORCING/LIFT LOOK TO LIFT NORTH OF THE FCST AREA FOR TONIGHT/ SUN MORNING...BUT STRONGER FORCING /IN THE FORM OF A PASSING MID LEVEL TROUGH AND APPROACHING SFC-850MB TROUGH/FRONT/ MOVES BACK INTO THE AREA SUN AFTERNOON/EVENING. MORE WIDESPREAD CONVECTION... CAPABLE OF PRODUCING HEAVY RAINS...LOOKS LIKELY AS THESE FEATURES PASS. APPEARS A FLASH FLOOD WATCH MAY BE NEEDED AGAIN SUN AFTERNOON INTO SUN NIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...DAS SHORT TERM...RRS LONG TERM....RRS AVIATION...DAS HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1237 PM CDT SAT JUN 22 2013 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND SUNDAY ISSUED AT 442 AM CDT SAT JUN 22 2013 CONTINUE WITH ISSUES ON WHERE AND WHEN CONVECTION WILL AFFECT AREA. WATER VAPOR IMAGERY SHOWING NUMBER OF DISTURBANCES MOVING THROUGH SOUTHWEST FLOW ALOFT OVER UPPER MIDWEST. CONVECTION ASSOCIATED WITH THESE DISTURBANCES CURRENTLY EXTENDS OVER SOUTHERN WI THROUGH MN AND NEBRASKA. MAIN ISSUES TONIGHT WITH THE CONVECTION...HEAVY RAIN. IR IMAGERY SHOWING WARMING TOPS ATTM WITH DOWNWARD TREND EXPECTED TO CONTINUE INTO THE MORNING HOURS. OVER NORTHEAST WI...STABLE AIR FILTERED SOUTH BEHIND BOUNDARY DROPPING SOUTH OUT OF LAKE SUPERIOR DURING THE EVENING. MODEL OF CHOICE QUESTIONABLE...WHILE GFS AND TO SOME EXTENT EC APPEARED TO BE DOING WELL AT 6Z WITH CONVECTIVE TRENDS...THEY QUICKLY LOSE REALITY AS MOVE INTO THIS MORNING. HAVE TRENDED TOWARDS CURRENT RADAR TRENDS AND HRRR WHICH BRINGS WAINING CONVECTION NORTH INTO CENTRAL AND NORTH CENTRAL WI THIS MORNING. THUS WILL GO HIGH CHANCE OR LIKELY OVER THESE LOCATIONS FOR FIRST PART OF DAY. REMAINDER OF AREA...LOWER CHANCE POPS THROUGH THE DAY. HRRR SUGGEST LIMITED PCPN THROUGH AFTERNOON. THIS MAKES SENSE AS BEST FORCING/ ISENTROPIC LIFT WEST OVER SOUTHERN MN THIS AFTERNOON...EVENING. MODELS CONTINUE TO TRY AND BRING WARM FRONT NORTH THROUGH THE AREA TONIGHT. WITH UNCERTAINTY...WILL STICK TO CHANCE POPS THROUGH SUN. COLD FRONT APPROACHES STATE LATE IN DAY SUN AS MAIN UPPER WAVE LIFTS NORTHEAST THROUGH HIGH PLAINS. TRENDED POPS HIGHER WEST GIVEN PROXIMITY OF FRONT. AGAIN OVERNIGHT STORMS PRODUCED SIG PCPN AS HAVE PLENTY OF MOISTURE TO WORK WITH WITH PW`S IN 1.5 TO 2.0 INCH RANGE. THIS TO CONTINUE INTO SUNDAY. PLENTY OF INSTABILITY AROUND THROUGH THE PERIOD...THOUGH SHEAR IS LIMITED AT LEAST UNTIL SUN...WHEN MODELS SUGGEST INCREASES TO NR 40 KTS. WILL CONTINUE TO HIGHLIGHT HEAVY RAIN POTENTIAL AS MAIN ISSUE...WITH STRONG DAMAGING WIND THREAT POSSIBLE TODAY AND TONIGHT. GIVEN LOW CLOUDS/CLOUDS EXPECTED FOR FIRST HALF OF DAY AND EASTERLY COMPONENT OF WIND...HAVE DROPPED HIGHS A GOOD 5 DEGS TODAY. HAVE NOT MADE ANY SIG CHANGE TO SUN ATTM DUE TO UNCERTAINTY ON CONVECTION. .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY ISSUED AT 442 AM CDT SAT JUN 22 2013 UPPER RIDGE WILL GRADUALLY RETROGRADE WESTWARD INTO THE WESTERN UNITED STATES. THIS WILL EVENTUALLY CHANGE THE SOUTHWEST FLOW PATTERN TO A NORTHWEST FLOW PATTERN...BRINGING COOLER TEMPERATURES AND LOWER HUMIDITY BY THE END OF THE WEEK. CONSIDERING MODELS ARE HAVING TOUGH TIME OVER THE LAST FEW DAYS IN THE PLACEMENT OF CONVECTION AND LOCALLY HEAVY RAIN...LOWER THAN NORMAL CONFIDENCE IN THE DETAILS OF THE FORECAST AS THE MODELS CONTINUE TO SHOW SEVERAL COMPLEXES MOVING ACROSS THE WESTERN GREAT LAKES EARLY TO MIDDLE OF NEXT WEEK. THEREFORE...WILL CONTINUE CHANCES OF SHOWERS AND THUNDERSTORMS EACH DAY THROUGHOUT THE PERIOD. SOME INDICATIONS BY THE MODELS THAT MONDAY COULD END UP BEING DRIER THAN ADVERTISED...BUT WILL BELIEVE IT WHEN I SEE IT. STILL THE POTENTIAL FOR SEVERE WEATHER AND LOCALLY HEAVY EARLY TO MIDDLE PORTIONS OF NEXT WEEK. HAZARDOUS WEATHER OUTLOOK HAS THIS MENTIONED ALONG WITH THE UNCERTAINTY IN TIMING. ONLY MINOR CHANGES MADE TO THE EXTENDED FORECAST ON A FEW DAYS...MORE COORDINATION PURPOSES. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1236 PM CDT SAT JUN 22 2013 CONFIDENCE HAS NOT IMPROVED ANY IN THE FORECAST DETAILS OVER THE NEXT 24 HOURS. PARTIAL CLEARING OCCURRING IN THE VICINITY OF VARIOUS SHORTWAVE TROUGHS OVER MINNESOTA AND WESTERN WISCONSIN SUGGESTS POTENTIAL FOR STORMS WILL INCREASE LATER THIS AFTERNOON IF THESE TRENDS CONTINUE. IF STORMS DEVELOP...WOULD LIKELY IMPACT CENTRAL AND NORTH-CENTRAL WISCONSIN. NOCTURNAL STORMS COULD ALSO REFIRE ALONG A WARM FRONT AS IT LIFTS NORTH OVER MINNESOTA AND WISCONSIN TONIGHT. IF THIS OCCURS...STORMS WOULD TRACK ALONG THE WARM FRONT EAST-SOUTHEAST INTO NORTH-CENTRAL WISCONSIN AND POSSIBLY NORTHEAST WISCONSIN LATE. UNCERTAINTIES REVOLVING AROUND LOCATION AND TIMING OF STORMS IS TOO HIGH TO INCLUDE TSRA IN TAFS AT THIS TIME. OTHERWISE...CIGS IMPROVING THIS AFTERNOON TO VFR. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....TE LONG TERM......ECKBERG AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1020 AM CDT SAT JUN 22 2013 .UPDATE... N-S CONVECTIVE BAND OVER SOUTHERN WI WILL CONTINUE TO MOVE EAST TO OVER LAKE MICHIGAN BY EARLY AFTERNOON. HAVE UPDATED THE FORECAST TO REFLECT THIS AND INCREASED CHANCES OF RAIN TO CATEGORICAL. HAVE KNOCKED MAX TEMPS DOWN A FEW DEGREES SINCE USUAL DAYTIME HEATING WILL NOT BE THERE. IN FACT...WE WILL PROBABLY KNOCK THEM BACK IN MORE SINCE IT`LL BE MOSTLY CLOUDY WITH CONVECTIVE CLOUD CANOPY OVERHEAD. YESTERDAY WE NEVER RECOVERED PAST 80. THE AFTERNOON HOURS SHOULD BE QUIET AFTER THE CONVECTIVE BAND EXITS....LIKE YESTERDAY. FORECAST MODELS..BOTH THE LARGE SCALE AND MESO TYPES HAVE VARIOUS SOLUTIONS FOR THUNDERSTORM POSSIBILITIES THIS AFTERNOON AND TONIGHT. GIVEN THAT LOW LEVEL BOUNDARY HAS BEEN SHOVED BACK SOUTH INTO NORTHERN ILLINOIS MAKES IT DIFFICULT TO GET REGENERATION OF STORMS OVER SOUTHERN WI UNTIL LATE IN THE AFTERNOON. HRRR MODELS HINTS AT THIS. .AVIATION/18Z TAFS/... JUST PRIOR TO 18Z THERE WERE POCKETS OF IFR CIGS ALONG OR NEAR THE LAKE MICHIGAN SHORELINE FROM MILWAUKEE TO KENOSHA. EXPECT THESE CONDITIONS TO BE REINFORCED BY CONVECTIVE RAIN BAND WHICH WILL MOVE FROM SOUTHCENTRAL INTO SOUTHEAST WISCONSIN AND THEN OVER LAKE MICHIGAN. OTHERWISE...VFR CONDS WITH MULTIPLE LAYERS OF CLOUDS. BRIEF MVFR VSBY CONDITIONS WITH THE HEAVIER SHOWERS/RAIN. CIGS AND VISIBILITIES SHOULD BE UP AND DOWN SATURDAY NIGHT WITH ADDITIONAL CHANCES OF SHOWERS AND STORMS. HOWEVER...GENERALLY VFR CONDS EXPECTED. .PREV DISCUSSION...ISSUED 238 AM CDT SAT JUN 21 2013 .SHORT TERM...TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM. THE 250 MB UPPER RIDGE EXTENDS FROM THE SOUTHEAST U.S. INTO THE LAKE MICHIGAN AREA...WITH A SHORTWAVE OVER THE NORTHERN ROCKIES. AT 500 MB A MODERATE SOUTHWEST FLOW WILL PERSIST ACROSS THE NORTHERN PLAINS TO NORTHWEST WISCONSIN. ACTIVE THUNDERSTORM FORECAST FOR THIS PERIOD ACROSS THE AREA. SHORT TERM MODELS INDICATE THE SURFACE WARM FRONT WILL BE NEAR THE FORECAST AREA AND TENT TO SHIFT NORTHWARD TONIGHT. 850MB THERMAL RIDGE WILL REMAIN POINTED INTO THE REGION TODAY AND TONIGHT. THE NOSE OF THE 850MB LOW LEVEL JET IS ACROSS SOUTHERN WISCONSIN EARLY THIS MORNING...THEN PUSHES EAST TOWARDS THE EASTERN GREAT LAKES WHILE THE MAIN JET ACROSS THE CENTRAL PLAINS INTO IOWA TODAY WITH A 30 KNOT FLOW ACROSS SOUTHERN WISCONSIN AGAIN TONIGHT. PRECIPITABLE WATER VALUES REMAIN HIGH AROUND 1.5 TO 2 INCHES. NONE OF THE MESO MODELS ARE DOING A VERY GOOD JOB WITH THE THUNDERSTORMS. IT APPEARS A WEST TO EAST LINE OF THUNDERSTORMS EXTENDS FROM THE IOWA MINNESOTA BORDER TO SOUTHERN LAKE MICHIGAN JUST NORTH OF THE 850 MOISTURE TRANSPORT VECTORS. THE EAST PART OF THIS LINE WAS SAGGING SOUTH...BUT WEST OF MADISON THERE IS A SLOW NORTH PUSH. THIS WOULD SUPPORT A LARGE MCC WHICH SHOULD AFFECT THE FORECAST AREA THIS MORNING. THEN MORE STORMS COULD FORM THIS AFTERNOON AND TONIGHT. HEAVY RAINFALL IS EXPECTED AND A FLASH FLOOD WATCH MAY BE NEEDED. HOWEVER THE CURRENT SHORT TERM MESO MODELS WOULD NOT INDICATE ENOUGH RAINFALL FOR THIS. TEMPERATURES ARE GOING TO BE TOUGH AS WELL...DEPENDING ON CONVECTION TRENDS AND CLOUDS. M ID 80S MOST LIKELY GIVEN THE EXPECTED CLOUD DEBRIS. HOWEVER WITH THE HIGH DEW POINTS IT WILL BE HUMID. .SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE MEDIUM. MAIN CONCERNS ARE WX/POPS AND HIGH TEMPERATURES. SUNDAYS WEATHER ARE TIED TO WHETHER OR NOT A MESOSCALE LIFTING MECHANISM WILL BE PRESENT AND CAP CAN HOLD. OTHERWISE THE OTHER INGREDIENTS FOR DEEP MOIST CONVECTION WILL BE PRESENT - A MODERATELY UNSTABLE ENVIRONMENT WITH AT LEAST 1500-2000 J/KG MEAN LAYER CAPE AND AMPLE LOW-LEVEL MOISTURE WITH SURFACE DEW POINTS AROUND 70. THOUGH STORM MODE AND ORGANIZATION WILL BE A LIMITING FACTOR IN ALL OF THIS GIVEN THE LOW VALUES OF DEEP LAYER 0-6 KM SHEAR. DRY CONDITIONS MAY BE SEEN IF THE CAP HOLDS AND SUNDAY LACKS A LIFTING MECHANISM. KEPT A SLIGHT CHANCE/CHANCE GIVEN THE UNCERTAINTY. THE BETTER CHANCE FOR PRECIP EXISTS SUNDAY NIGHT INTO MONDAY. WHEREIN...NUMERICAL MODELS ARE IN A GENERAL AGREEMENT OF A SHORT WAVE TROUGH AND AN ASSOCIATED VORT MAX MOVING THROUGH THE AREA OVERNIGHT/EARLY MONDAY. PRECIP CHANCES CONTINUE MONDAY AS PRECIP FROM THE MORNING COULD LINGER AND GIVEN THE SUPPORT OF SYNOPTIC LIFT...SEEN WITH LOW-LEVEL Q-VECTOR DIVG IN PLACE AND LIGHT LOW- LEVEL WAA OCCURRING. THE MODEL CONSENSUS FOR 925 HPA TEMPS SUNDAY ARE AROUND 24-26 C THAT CORRESPOND TO 87-91 F PROVIDED INSOLATION/MIXING IS SUFFICIENT. ANY CONVECTIVE DEBRIS THOUGH WOULD IMPACT THIS. RH FIELDS AND WHAT IS EXPECTED REGARDING WX/POPS GIVE CONFIDENCE TO LEAN TOWARDS THE HIGHER GUIDANCE WITH HIGHS IN THE UPPER 80S-AROUND 90 FORECAST. HEAT INDICES ARE EXPECTED TO BE GENERALLY IN THE MID TO UPPER 90S SUNDAY. .LONG TERM...TUESDAY THROUGH FRIDAY NIGHT...FORECAST CONFIDENCE MEDIUM. SHIFT IN THE PATTERN STILL EXPECTED THIS WEEK WITH A MORE ZONAL 500 HPA PATTERN DEVELOPING MONDAY-TUESDAY ASSOCIATED WITH HT RISES IN THE NORTHERN ROCKIES AND GREAT PLAINS SUNDAY-EARLY MONDAY. CHANCES FOR PRECIP WILL CONTINUE INTO THE NEW WORK WEEK AS SHORT WAVES TROUGHS TRAVERSE THE REGION WITH THE BEST CHANCES TUESDAY AFTERNOON INTO WEDNESDAY. HIGHS ABOVE NORMAL UNTIL FRIDAY WHEN PATTERN BREAKS DOWN AS A LONG WAVE TROUGH DEVELOPS OVER THE GREAT LAKES REGION. NORTHWEST FLOW WILL USHER COOLER AIR FRIDAY AND SATURDAY WITH HIGHS MOVING TOWARDS BELOW/NEAR NORMAL SEASONAL VALUES. && .AVIATION/12Z TAFS/... A BAND OF THUNDERSTORMS WILL EXTEND ACROSS SOUTHERN WISCONSIN DURING THE EARLY MORNING HOURS. MVFR/IFR IN STORMS...WITH VFR TO THE NORTH OF THE BAND. SOME MVFR CLOUDS THIS MORNING...THEN MAINLY VFR. THE CHANCE OF THUNDERSTORMS WILL CONTINUE THIS AFTERNOON AND TONIGHT WITH A WARM FRONT ACROSS/NEAR SOUTHERN WISCONSIN. && .MARINE... DEW POINTS RISING THROUGH THE 60S WILL OVERSPREAD THE COOL LAKE WATERS TODAY AND TONIGHT. SOME FOG FORMATION IS POSSIBLE...AND MAY LINGER ON AND OFF THROUGH THE WEEKEND. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...SH SUNDAY THROUGH FRIDAY...ET
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
653 AM CDT SAT JUN 22 2013 UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND SUNDAY ISSUED AT 442 AM CDT SAT JUN 22 2013 CONTINUE WITH ISSUES ON WHERE AND WHEN CONVECTION WILL AFFECT AREA. WATER VAPOR IMAGERY SHOWING NUMBER OF DISTURBANCES MOVING THROUGH SOUTHWEST FLOW ALOFT OVER UPPER MIDWEST. CONVECTION ASSOCIATED WITH THESE DISTURBANCES CURRENTLY EXTENDS OVER SOUTHERN WI THROUGH MN AND NEBRASKA. MAIN ISSUES TONIGHT WITH THE CONVECTION...HEAVY RAIN. IR IMAGERY SHOWING WARMING TOPS ATTM WITH DOWNWARD TREND EXPECTED TO CONTINUE INTO THE MORNING HOURS. OVER NORTHEAST WI...STABLE AIR FILTERED SOUTH BEHIND BOUNDARY DROPPING SOUTH OUT OF LAKE SUPERIOR DURING THE EVENING. MODEL OF CHOICE QUESTIONABLE...WHILE GFS AND TO SOME EXTENT EC APPEARED TO BE DOING WELL AT 6Z WITH CONVECTIVE TRENDS...THEY QUICKLY LOSE REALITY AS MOVE INTO THIS MORNING. HAVE TRENDED TOWARDS CURRENT RADAR TRENDS AND HRRR WHICH BRINGS WAINING CONVECTION NORTH INTO CENTRAL AND NORTH CENTRAL WI THIS MORNING. THUS WILL GO HIGH CHANCE OR LIKELY OVER THESE LOCATIONS FOR FIRST PART OF DAY. REMAINDER OF AREA...LOWER CHANCE POPS THROUGH THE DAY. HRRR SUGGEST LIMITED PCPN THROUGH AFTERNOON. THIS MAKES SENSE AS BEST FORCING/ ISENTROPIC LIFT WEST OVER SOUTHERN MN THIS AFTERNOON...EVENING. MODELS CONTINUE TO TRY AND BRING WARM FRONT NORTH THROUGH THE AREA TONIGHT. WITH UNCERTAINTY...WILL STICK TO CHANCE POPS THROUGH SUN. COLD FRONT APPROACHES STATE LATE IN DAY SUN AS MAIN UPPER WAVE LIFTS NORTHEAST THROUGH HIGH PLAINS. TRENDED POPS HIGHER WEST GIVEN PROXIMITY OF FRONT. AGAIN OVERNIGHT STORMS PRODUCED SIG PCPN AS HAVE PLENTY OF MOISTURE TO WORK WITH WITH PW`S IN 1.5 TO 2.0 INCH RANGE. THIS TO CONTINUE INTO SUNDAY. PLENTY OF INSTABILITY AROUND THROUGH THE PERIOD...THOUGH SHEAR IS LIMITED AT LEAST UNTIL SUN...WHEN MODELS SUGGEST INCREASES TO NR 40 KTS. WILL CONTINUE TO HIGHLIGHT HEAVY RAIN POTENTIAL AS MAIN ISSUE...WITH STRONG DAMAGING WIND THREAT POSSIBLE TODAY AND TONIGHT. GIVEN LOW CLOUDS/CLOUDS EXPECTED FOR FIRST HALF OF DAY AND EASTERLY COMPONENT OF WIND...HAVE DROPPED HIGHS A GOOD 5 DEGS TODAY. HAVE NOT MADE ANY SIG CHANGE TO SUN ATTM DUE TO UNCERTAINTY ON CONVECTION. .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY ISSUED AT 442 AM CDT SAT JUN 22 2013 UPPER RIDGE WILL GRADUALLY RETROGRADE WESTWARD INTO THE WESTERN UNITED STATES. THIS WILL EVENTUALLY CHANGE THE SOUTHWEST FLOW PATTERN TO A NORTHWEST FLOW PATTERN...BRINGING COOLER TEMPERATURES AND LOWER HUMIDITY BY THE END OF THE WEEK. CONSIDERING MODELS ARE HAVING TOUGH TIME OVER THE LAST FEW DAYS IN THE PLACEMENT OF CONVECTION AND LOCALLY HEAVY RAIN...LOWER THAN NORMAL CONFIDENCE IN THE DETAILS OF THE FORECAST AS THE MODELS CONTINUE TO SHOW SEVERAL COMPLEXES MOVING ACROSS THE WESTERN GREAT LAKES EARLY TO MIDDLE OF NEXT WEEK. THEREFORE...WILL CONTINUE CHANCES OF SHOWERS AND THUNDERSTORMS EACH DAY THROUGHOUT THE PERIOD. SOME INDICATIONS BY THE MODELS THAT MONDAY COULD END UP BEING DRIER THAN ADVERTISED...BUT WILL BELIEVE IT WHEN I SEE IT. STILL THE POTENTIAL FOR SEVERE WEATHER AND LOCALLY HEAVY EARLY TO MIDDLE PORTIONS OF NEXT WEEK. HAZARDOUS WEATHER OUTLOOK HAS THIS MENTIONED ALONG WITH THE UNCERTAINTY IN TIMING. ONLY MINOR CHANGES MADE TO THE EXTENDED FORECAST ON A FEW DAYS...MORE COORDINATION PURPOSES. && .AVIATION...FOR 12Z TAF ISSUANCE ISSUED AT 638 AM CDT SAT JUN 22 2013 LOW CIGS OVER FAR NORTH ASSOCIATED WITH STABLE NORTHEAST FLOW OFF LAKE SUPERIOR AND ABUNDANT LOW LEVEL MOISTURE WILL LIFT THIS MORNING AS DECAYING AREA OF CONVECTION MOVES INTO THE REGION. MORNING SHOWERS AND THUNDERSTORMS EXPECTED TO CONTINUE TO WANE WITH QUIET MID DAY PERIOD EXPECTED. SHOWER AND TSTM REDEVELOPMENT POSSIBLE LATER THIS AFTERNOON ESPECIALLY NORTHWEST PORTION OF WI AS NEXT UPPER DISTURBANCE MOVES THROUGH. STRONG INSTABILITY IS EXPECTED...SO STRONG/SEVERE TSTMS WITH TORRENTIAL RAINFALL ARE POSSIBLE. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....TE LONG TERM......ECKBERG AVIATION.......TE
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND SUNDAY ISSUED AT 442 AM CDT SAT JUN 22 2013 CONTINUE WITH ISSUES ON WHERE AND WHEN CONVECTION WILL AFFECT AREA. WATER VAPOR IMAGERY SHOWING NUMBER OF DISTURBANCES MOVING THROUGH SOUTHWEST FLOW ALOFT OVER UPPER MIDWEST. CONVECTION ASSOCIATED WITH THESE DISTURBANCES CURRENTLY EXTENDS OVER SOUTHERN WI THROUGH MN AND NEBRASKA. MAIN ISSUES TONIGHT WITH THE CONVECTION...HEAVY RAIN. IR IMAGERY SHOWING WARMING TOPS ATTM WITH DOWNWARD TREND EXPECTED TO CONTINUE INTO THE MORNING HOURS. OVER NORTHEAST WI...STABLE AIR FILTERED SOUTH BEHIND BOUNDARY DROPPING SOUTH OUT OF LAKE SUPERIOR DURING THE EVENING. MODEL OF CHOICE QUESTIONABLE...WHILE GFS AND TO SOME EXTENT EC APPEARED TO BE DOING WELL AT 6Z WITH CONVECTIVE TRENDS...THEY QUICKLY LOSE REALITY AS MOVE INTO THIS MORNING. HAVE TRENDED TOWARDS CURRENT RADAR TRENDS AND HRRR WHICH BRINGS WAINING CONVECTION NORTH INTO CENTRAL AND NORTH CENTRAL WI THIS MORNING. THUS WILL GO HIGH CHANCE OR LIKELY OVER THESE LOCATIONS FOR FIRST PART OF DAY. REMAINDER OF AREA...LOWER CHANCE POPS THROUGH THE DAY. HRRR SUGGEST LIMITED PCPN THROUGH AFTERNOON. THIS MAKES SENSE AS BEST FORCING/ ISENTROPIC LIFT WEST OVER SOUTHERN MN THIS AFTERNOON...EVENING. MODELS CONTINUE TO TRY AND BRING WARM FRONT NORTH THROUGH THE AREA TONIGHT. WITH UNCERTAINTY...WILL STICK TO CHANCE POPS THROUGH SUN. COLD FRONT APPROACHES STATE LATE IN DAY SUN AS MAIN UPPER WAVE LIFTS NORTHEAST THROUGH HIGH PLAINS. TRENDED POPS HIGHER WEST GIVEN PROXIMITY OF FRONT. AGAIN OVERNIGHT STORMS PRODUCED SIG PCPN AS HAVE PLENTY OF MOISTURE TO WORK WITH WITH PW`S IN 1.5 TO 2.0 INCH RANGE. THIS TO CONTINUE INTO SUNDAY. PLENTY OF INSTABILITY AROUND THROUGH THE PERIOD...THOUGH SHEAR IS LIMITED AT LEAST UNTIL SUN...WHEN MODELS SUGGEST INCREASES TO NR 40 KTS. WILL CONTINUE TO HIGHLIGHT HEAVY RAIN POTENTIAL AS MAIN ISSUE...WITH STRONG DAMAGING WIND THREAT POSSIBLE TODAY AND TONIGHT. GIVEN LOW CLOUDS/CLOUDS EXPECTED FOR FIRST HALF OF DAY AND EASTERLY COMPONENT OF WIND...HAVE DROPPED HIGHS A GOOD 5 DEGS TODAY. HAVE NOT MADE ANY SIG CHANGE TO SUN ATTM DUE TO UNCERTAINTY ON CONVECTION. .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY ISSUED AT 442 AM CDT SAT JUN 22 2013 UPPER RIDGE WILL GRADUALLY RETROGRADE WESTWARD INTO THE WESTERN UNITED STATES. THIS WILL EVENTUALLY CHANGE THE SOUTHWEST FLOW PATTERN TO A NORTHWEST FLOW PATTERN...BRINGING COOLER TEMPERATURES AND LOWER HUMIDITY BY THE END OF THE WEEK. CONSIDERING MODELS ARE HAVING TOUGH TIME OVER THE LAST FEW DAYS IN THE PLACEMENT OF CONVECTION AND LOCALLY HEAVY RAIN...LOWER THAN NORMAL CONFIDENCE IN THE DETAILS OF THE FORECAST AS THE MODELS CONTINUE TO SHOW SEVERAL COMPLEXES MOVING ACROSS THE WESTERN GREAT LAKES EARLY TO MIDDLE OF NEXT WEEK. THEREFORE...WILL CONTINUE CHANCES OF SHOWERS AND THUNDERSTORMS EACH DAY THROUGHOUT THE PERIOD. SOME INDICATIONS BY THE MODELS THAT MONDAY COULD END UP BEING DRIER THAN ADVERTISED...BUT WILL BELIEVE IT WHEN I SEE IT. STILL THE POTENTIAL FOR SEVERE WEATHER AND LOCALLY HEAVY EARLY TO MIDDLE PORTIONS OF NEXT WEEK. HAZARDOUS WEATHER OUTLOOK HAS THIS MENTIONED ALONG WITH THE UNCERTAINTY IN TIMING. ONLY MINOR CHANGES MADE TO THE EXTENDED FORECAST ON A FEW DAYS...MORE COORDINATION PURPOSES. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1048 PM CDT FRI JUN 21 2013 INITIAL CLUSTER OF TSTMS HAS WEKENED AS IT MOVED TOWARD CENTRAL WI LATE THIS EVENING. ALTHOUGH THE FIRST ROUND OF STORMS SHOULD MISS THE TAF SITES...THERE SHOULD STILL BE A CHANCE OF STORMS ACROSS MUCH OF C/EC WI OVERNIGHT. MVFR CONDITIONS MAY ACCOMPANY THE TSTMS. LOW CLOUDS WILL BE FOUND ACROSS NORTHERN WI OVERNIGHT...AND MAY ALSO BE OCCUR ACROSS C/EC WI LATE TONIGHT INTO EARLY SAT. IMPROVING CONDITIONS ARE EXPECTED BY MID TO LATE SAT MORNING...WITH SCT TSTMS REDEVELOPING DURING THE LATE AFTERNOON/EARLY EVENING. STRONG INSTABILITY IS EXPECTED...SO STRONG/SEVERE TSTMS WITH TORRENTIAL RAINFALL ARE POSSIBLE. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....TE LONG TERM......ECKBERG AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1213 AM CDT SAT JUN 22 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 355 PM CDT FRI JUN 21 2013 AT 3 PM...A THUNDERSTORM COMPLEX WAS LOCATED OVER EASTERN SOUTH DAKOTA. THE HRRR SEEMS TO BE HANDLING THIS SYSTEM THE BEST THIS AFTERNOON. IT SHOWS THAT THIS SYSTEM WILL MOVE NORTHEAST INTO NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA LATE THIS AFTERNOON AND EARLY EVENING. THIS SYSTEM IS INITIALLY FOLLOWING THE SHORT WAVE TROUGH. HOWEVER AS THE LOW LEVEL JET STRENGTHENS THIS EVENING AND STRONG 850 MB MOISTURE TRANSPORT WILL MOVE INTO THE FORECAST AREA. EXPECT SOME DEVELOPMENT ALONG THE ADVANCING WARM FRONT ON THE SOUTH OF THIS PERIPHERY OF THIS SYSTEM. MLCAPES ALONG THIS BOUNDARY CLIMB TO AROUND 5000 J/KG LATE THIS AFTERNOON AND THEN CONTINUES INTO THE EARLY EVENING. WHILE THE 0-6 KM SHEAR IS NOT FAVORABLE FOR SUPERCELLS...THE 0-3 KM BULK SHEAR IS OVER 40 KNOTS AND IT WILL BE FAVORABLE FOR DAMAGING WINDS. IN ADDITION WITH DCAPES OVER 1500 J/KG...THIS WOULD ALSO MAKE IT FAVORABLE FOR THE STORMS TO PRODUCE DAMAGING WINDS. CURRENTLY EXPECTING THE CURRENT CONVECTION TO EVOLVE INTO 1 OR MORE BOW ECHOS AS THEY BECOME MORE COLD POOL DOMINANT...AND THESE LINES WOULD LIKELY MOVE ALONG OR NORTH OF THE INTERSTATE 90 CORRIDOR BETWEEN 22.03Z AND 22.09Z. HOWEVER IF THE BOUNDARY DOES NOT LIFT AS FAR NORTH AS THE MESO MODELS INDICATE...THIS CONVECTION COULD POTENTIALLY BE FURTHER SOUTH TONIGHT. FLASH FLOODING IS ALSO A CONCERN TONIGHT AS WARM CLOUD LAYER DEPTHS CLIMB INTO THE 4 TO 4.5 KM RANGE AND PRECIPITABLE WATER VALUES CLIMB INTO THE 1.8 TO 2.0 INCH RANGE. WITH THE LOW LEVEL JET CONTINUING TO IMPINGE ON THE FRONT NEAR THE MINNESOTA AND IOWA BORDER...EXPECT CONVECTION TO CONTINUE TO DEVELOP ACROSS EASTERN NEBRASKA...WESTERN IOWA AND SOUTHWEST MINNESOTA THROUGHOUT THE NIGHT. THIS CONVECTION WOULD THEN TRAIN INTO THE FORECAST AREA WITH THE MEAN WIND. WOULD NOT BE SHOCKED TO SEE 3 TO 5 INCHES OF RAIN FALL ACROSS PARTS OF THE AREA TONIGHT. THERE MAY BE EVEN SOME LOCALLY HIGHER AMOUNTS. THIS LOOKS LIKE A CLASSIC MADDOX WARM FRONTAL FLASH FLOOD EVENT. DUE TO THIS...ISSUED A FLASH FLOOD WATCH FOR TONIGHT AND SATURDAY MORNING. THE SHOWERS AND THUNDERSTORMS WILL GRADUALLY DIMINISH ON SATURDAY MORNING AS THE LOW LEVEL JET WEAKENS. ON SATURDAY AFTERNOON...THE MODELS SHOW THAT THE WARM FRONT WILL MOVE NORTHWARD TOWARD THE INTERSTATE 94 CORRIDOR. WITH THERE NOT MUCH MOISTURE CONVERGENCE ALONG THIS FRONT AND SOME CAPPING ALOFT...THERE IS A POTENTIAL THAT THE COULD BE SOME DRY HOURS. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 355 PM CDT FRI JUN 21 2013 ON SATURDAY NIGHT...MANY OF THE DETERMINISTIC MODELS SUGGEST THAT THE 850 MB MOISTURE TRANSPORT WILL SHIFT NORTHEAST OF THE AREA BY LATE EVENING. AS A RESULT...MANY OF THESE MODELS HAS THE FORECAST AREA DRYING OUT DURING THE 23.06Z TO 23.12Z TIME FRAME. IF THIS TREND CONTINUES...MAY HAVE TO LOWER OR POSSIBLY TAKE THESE PRECIPITATION CHANCES OUT OF THE FORECAST. FROM SUNDAY INTO TUESDAY...THE MODELS CONTINUE TO STRUGGLE WITH THE LOCATION OF THE FRONT AND WHERE MESOSCALE COMPLEXES MAY DEVELOP. AS A RESULT...THE FORECAST CONFIDENCE FOR THE TIMING AND LOCATION OF THE PRECIPITATION IS NOT AS CERTAIN. DUE TO THIS...STAYED WITH THE CONSALL PRECIPITATION CHANCES AND ALSO WITH THEIR MAXIMUM AND MINIMUM TEMPERATURES. ON ANY OF THESE DAYS...TEMPERATURES COULD EASILY CLIMB INTO THE LOWER 90S IF ENOUGH SUNSHINE CAN OCCUR. FROM WEDNESDAY INTO FRIDAY...THE DETERMINISTIC MODELS ARE SHOWING THAT THE UPPER LEVEL RIDGE WILL RETROGRADE INTO THE WESTERN UNITED STATES AND WESTERN CANADA. THIS IS IN RESPONSE TO A MODERATE MADDEN JULIAN OSCILLATION MOVING TOWARD THE INTERNATIONAL DATELINE. WHEN THIS OCCURS IN SUMMER...CLIMATE PREDICTION CENTER COMPOSITES FAVOR ABOVE NORMAL TEMPERATURE ANOMALIES ACROSS THE WESTERN UNITED STATES. AS A RESULT...CONFIDENCE IS HIGH THAT THIS WILL OCCUR...BUT THE EXACT TIME WHEN THIS WILL ULTIMATELY TAKE PLACE IS STILL A BIT UNCERTAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1212 AM CDT SAT JUN 22 2013 CONVECTION HAS BEEN STEADILY INCREASING SOUTH OF THE TAF SITES THIS EVENING AS THE LOW LEVEL JET INTERSECTS THE SURFACE BOUNDARY SITTING ACROSS NORTHEAST IOWA. EXPECT TO SEE THIS AREA FILL IN WITH CONVECTIVE ACTIVITY AND LIFT TO THE NORTH AND THEN MERGE WITH THE ACTIVITY COMING IN FROM SOUTHERN MINNESOTA. THIS ACTIVITY SHOULD THEN PROGRESS EAST ACROSS THE REGION DURING THE LATE NIGHT HOURS INTO EARLY SATURDAY MORNING. CAN NOT RULE OUT SOME GUSTY WINDS UNTIL THE MAIN BAND OF STORMS FROM THE WEST PASSES THROUGH ALONG WITH IFR CONDITIONS IN THE RAIN. ONCE THE MAIN BAND GOES THROUGH SHOULD CONTINUE TO SEE SOME SHOWERS AND OCCASIONAL THUNDERSTORMS FOR A COUPLE OF HOURS WITH MVFR CONDITIONS POSSIBLE. EXPECTING A RETURN TO VFR CONDITIONS ONCE THE RAIN ENDS AND THEN THE QUESTION BECOMES WHEN AND WHERE THE NEXT ROUND OF CONVECTION WILL FORM. THE 21.12Z HI-RES ARW HAS BEEN DOING A DECENT JOB IN THIS PATTERN AND SHOWS THE SURFACE BOUNDARY REMAINING SOUTH OF THE TAF SITES WITH ACTIVITY DEVELOPING IN THE LATE AFTERNOON AND CONTINUING INTO THE EVENING AS THE NEXT SHORT WAVE TROUGH COMES TOWARD THE AREA. CONFIDENCE ON THE TIMING AND PLACEMENT OF THIS IS NOT HIGH ENOUGH TO GO BEYOND A VCTS AT THIS TIME. && .HYDROLOGY...TONIGHT INTO SATURDAY ISSUED AT 355 PM CDT FRI JUN 21 2013 OVERNIGHT 1 TO 2 INCHES OF RAIN FELL ACROSS SOUTHEAST MINNESOTA...AND WEST CENTRAL AND NORTH CENTRAL WISCONSIN...AND 2 TO 4 INCHES FELL ACROSS NORTHEAST IOWA...AND SOUTHWEST AND CENTRAL WISCONSIN. THIS CAUSED RIVER FLOOD WARNINGS TO BE ISSUED ALONG THE BLACK AND KICKAPOO RIVERS IN WESTERN WISCONSIN. AS A STRONG LOW LEVEL JET BRINGS ABUNDANT MOISTURE INTO THE AREA TONIGHT. EXPECT THAT 3 TO 5 INCHES MAY FALL ACROSS PARTS OF THE AREA TONIGHT. A FEW LOCAL SPOTS MAY SEE EVEN HIGHER AMOUNTS. THINKING THAT THE BEST CHANCES ARE ALONG AND NORTH OF THE INTERSTATE 90 CORRIDOR. HOWEVER THERE IS STILL SOME UNCERTAINTY IN THIS. THIS ADDITIONAL RAIN WILL LIKELY RESULT IN SOME FLASH FLOODING TONIGHT. AS A RESULT...WENT WITH A FLASH FLOOD WATCH FOR THE ENTIRE AREA TONIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR WIZ017-029- 032>034-041>044-053>055-061. MN...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR MNZ079-086>088- 094>096. IA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR IAZ008>011-018- 019-029-030. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...04 HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1127 PM MDT FRI JUN 21 2013 .UPDATE... ISSUED AT 1025 PM MDT FRI JUN 21 2013 CONVECTION CONTINUES TO WIND DOWN ACROSS THE CWA AS THE ATMOSPHERE STABILIZES. ALTHOUGH A FEW LIGHT SHOWERS AND EMBEDDED THUNDERSTORMS WILL STILL BE A POSSIBILITY ACROSS EASTERN AND NORTHERN ZONES THROUGH THE REST OF THE NIGHT...NO LONGER EXPECT THE POSSIBILITY OF SEVERE WEATHER. SO...HAVE LET THE SEVERE THUNDERSTORM WATCH EXPIRE AT 10 PM. INITIAL GLANCE AT 00Z MODEL DATA CONTINUES TO POINT TO ANOTHER ACTIVE DAY ON SATURDAY. HAHN && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 300 PM MDT FRI JUN 21 2013 BELIEVE WE ARE PRIMED FOR A SEVERE WEATHER EPISODE THIS AFTERNOON. CONDITIONS ARE SET FOR SEVERE THUNDERSTORMS. CHALLENGES ARE WHERE AND WHEN. CURRENTLY...STRATUS LAYER ON VISIBLE IMAGERY CONTINUES TO ERODE ACROSS DAWES AND SIOUX COUNTIES IN THE PANHANDLE AND NIOBRARA COUNTY IN EAST CENTRAL WYOMING. DEWPOINTS REMAIN EXTREMELY HIGH (FOR OUR NECK OF THE WOODS)...IN THE PANHANDLE. ALLIANCE STILL REPORTING A DEW POINT OF 67 DEGREES...WITH LOW TO MID 60S ELSEWHERE. LATEST STORM PREDICTION CENTER MESOANALYSIS SHOWING CAPE ALREADY IN MOST OF THE PANHANDLE OF 4500 TO 5000 J/KG. ALL THAT IS NEEDED IS A LIFTING MECHANISM AND THAT IS DEVELOPING. A DRY LINE LAYS ACROSS EXTREME SOUTHEASTERN WYOMING...ROUGHLY FROM JUST EAST OF CHEYENNE TO JUST WEST OF TORRINGTON AND THEN NORTHWEST TO DOUGLAS. BEHIND THIS LINE...DEWPOINTS HAVE FALLEN INTO THE 20S. ALONG THIS LINE...SEEING CU DEVELOPING ALONG THE LINE. HAVE A PRETTY GOOD CELL ALREADY DEVELOPING IN NORTHERN LARAMIE COUNTY AND SOUTHERN GOSHEN COUNTY. THIS IS MOST LIKELY THE START OF OUR EVENT. JUST RECEIVED A SWOMCD FROM SPC AT 113 PM STATING A WATCH IS LIKELY...SO ANOTHER HOUR OR SO...CONVECTION SHOULD INITIATE. LATEST HRRR COMPOSITE REFLECTIVITY FORECAST SHOWING THAT CELL IN SOUTHERN GOSHEN COUNTY TAKING OFF AROUND 3 PM. BY THAT TIME...LOW STRATUS SHOULD BE MIXED OUT OVER THE NORTHERN PANHANDLE. SUPER CELL THEN MOVES EAST INTO THE CENTRAL PANHANDLE. WITH SUCH LARGE CAPE...GOING TO SEE SOME VERY LARGE HAIL REPORTS. NAM/WRF FORECAST SOUNDINGS CONTINUE TO SHOW STRONGLY VEERING WINDS WITH NORTHEASTERLY TO EASTERLY SURFACE WINDS AND 35-40KT SOUTHWESTERLY WINDS AT 700MBS. MORE THAN ENOUGH SHEAR TO SUPPORT SUPERCELLS CONTINUING INTO THE PANHANDLE. LATEST NAM HELICITIES FOR LATER THIS AFTERNOON/EVENING SHOWING 150M2/S2...INCREASING TO OVER 300M2/S2 OVER CONVERSE AND NIOBRARA COUNTIES AFTER 00Z...SPREADING INTO THE NORTHERN PANHANDLE AFTERWARDS. LCLS QUITE LOW UP THERE AS WELL...SO THE TORNADO THREAT WILL LIKELY BE FROM 23Z THROUGH MAYBE 02 TO 03Z TIME FRAME. SEVERE THUNDERSTORMS COULD LAST WELL INTO THE EVENING AND OVERNIGHT HOURS IN THE PANHANDLE. FOR SATURDAY...PRETTY MUCH A REPEAT OF TODAY WITH SEVERE THUNDERSTORMS OVER EAST CENTRAL WYOMING AND NEBRASKA PANHANDLE. SHOULD BEGIN TO SEE A DECREASE IN LOW LEVEL MOISTURE SUNDAY AS WINDS SHIFT TO THE SOUTHWEST. COULD STILL SEE SOME SEVERE THUNDERSTORMS IN THE PANHANDLE SUNDAY AFTERNOON. .LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 300 PM MDT FRI JUN 21 2013 DUE TO THE THREAT OF SEVERE WEATHER THIS AFTERNOON...WILL KEEP LONG TERM DISCUSSION BRIEF SINCE NOT MUCH HAS CHANGED SINCE YESTERDAY. MODELS CONTINUING TO SHOW SOUTHWEST FLOW ALOFT AND RELATIVELY QUIET WEATHER FOR NEXT WEEK. THERE APPEARS TO BE LITTLE IN THE WAY OF RAINFALL CHANCES ACROSS SOUTHEAST WYOMING NEXT WEEK...WITH A SLIGHTLY BETTER CHANCE ACROSS WESTERN NEBRASKA ON MONDAY AHEAD OF A WEAK COOL FRONT. MODELS SHOW THIS PACIFIC FRONT SLIDING EASTWARD ACROSS THE NORTHERN ROCKIES MONDAY NIGHT AND INTO TUESDAY. THE GFS AND THE GEM HAVE TRENDED TOWARDS THE ECMWF SOLUTION...SHOWING THE FRONT STALLING FURTHER TO THE NORTH AS THE UPPER LEVEL TROUGH IS FURTHER NORTH AS WELL AND MORE PROGRESSIVE. THE MAIN IMPACT FROM THIS FRONT WILL BE WINDY CONDITIONS...MAINLY WEST OF THE LARAMIE RANGE ON MONDAY AND TUESDAY. TEMPERATURES WILL NOT LOWER MUCH...IF AT ALL...ESPECIALLY FURTHER SOUTH NEAR THE I80 CORRIDOR. THERE APPEARS TO BE A BETTER CHANCE OF TSTORMS AHEAD OF THIS FRONT ON MONDAY...AS A WEAK SHORTWAVE MOVES NORTHEAST ACROSS THE HIGH PLAINS. INCREASED POP MONDAY AND MONDAY EVENING MAINLY ACROSS WESTERN NEBRASKA. AFTER THAT...MODELS ALL INDICATE A STRONG UPPER LEVEL HIGH DEVELOPING AND INTENSIFYING NEAR THE FOUR CORNERS REGION BY WEDNESDAY AND THURSDAY. THIS WILL RESULT IN A PERIOD OF LIGHT WINDS BUT ALSO VERY WARM OR HOT TEMPERATURES THROUGH LATE NEXT WEEK. WITH THE EXCEPTION OF MONDAY...KEPT POP BELOW 10 PERCENT THROUGH THE WEEK. HIGH TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL AND GENERALLY IN THE 80S AND 90S. THIS UPPER LEVEL HIGH WILL BEGIN TO DRIFT WESTWARD BY LATE IN THE WEEK...ALLOWING A CANADIAN COLD FRONT TO PUSH SOUTH. THIS MAY INCREASE PRECIPITATION AND TSTORM CHANCES BY NEXT WEEKEND DUE FAVORABLE EASTERLY FLOW BEHIND THE BOUNDARY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY EVENING) ISSUED AT 1127 PM MDT FRI JUN 21 2013 VFR EXPECTED ACROSS SE WYOMING THROUGH SAT MORNING. SCTD SHOWERS AND A FEW STORMS WILL CONTINUE OVER PARTS OF THE PANHANDLE THROUGH 09Z WITH RESIDUAL MOISTURE POSSIBLY PRODUCING SOME SCTD IFR CIGS AFT 09Z UNTIL ABOUT 15Z. SCTD SHOWERS AND STORMS EXPECTED AGAIN SAT AFTERNOON AND EVENING MAINLY OVER THE PANHANDLE. && .FIRE WEATHER... ISSUED AT 300 PM MDT FRI JUN 21 2013 DRY AND BREEZY CONDITIONS CONTINUE ALONG AND WEST OF THE LARAMIE RANGE THIS AFTERNOON. TO THE EAST IN THE PANHANDLE AND UP OVER NIOBRARA COUNTY...HIGH HUMIDITIES WILL LEAD TO SEVERE THUNDERSTORMS LATER THIS AFTERNOON AND EVENING. HUMIDITIES OUT WEST ONCE AGAIN IN THE SINGLE DIGITS WITH WIND GUSTS FROM THE SOUTHWEST AT 30 TO 35 MPH. WINDS WILL EASE AFTER SUNSET. CONDITIONS LOOK TO REPEAT FOR SATURDAY AND TO A LESSER EXTENT ON SUNDAY AFTERNOON. STRONG WINDS WILL CONTINUE NEXT WEEK...PARTICULARLY MONDAY NIGHT INTO TUESDAY WITH WIND GUSTS EXCEEDING 40 MPH POSSIBLE OUT WEST. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...HAHN SHORT TERM...CLAYCOMB LONG TERM...TJT AVIATION...RE FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1025 PM MDT FRI JUN 21 2013 .UPDATE... ISSUED AT 1025 PM MDT FRI JUN 21 2013 CONVECTION CONTINUES TO WIND DOWN ACROSS THE CWA AS THE ATMOSPHERE STABILIZES. ALTHOUGH A FEW LIGHT SHOWERS AND EMBEDDED THUNDERSTORMS WILL STILL BE A POSSIBILITY ACROSS EASTERN AND NORTHERN ZONES THROUGH THE REST OF THE NIGHT...NO LONGER EXPECT THE POSSIBILITY OF SEVERE WEATHER. SO...HAVE LET THE SEVERE THUNDERSTORM WATCH EXPIRE AT 10 PM. INITIAL GLANCE AT 00Z MODEL DATA CONTINUES TO POINT TO ANOTHER ACTIVE DAY ON SATURDAY. HAHN && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 300 PM MDT FRI JUN 21 2013 BELIEVE WE ARE PRIMED FOR A SEVERE WEATHER EPISODE THIS AFTERNOON. CONDITIONS ARE SET FOR SEVERE THUNDERSTORMS. CHALLENGES ARE WHERE AND WHEN. CURRENTLY...STRATUS LAYER ON VISIBLE IMAGERY CONTINUES TO ERODE ACROSS DAWES AND SIOUX COUNTIES IN THE PANHANDLE AND NIOBRARA COUNTY IN EAST CENTRAL WYOMING. DEWPOINTS REMAIN EXTREMELY HIGH (FOR OUR NECK OF THE WOODS)...IN THE PANHANDLE. ALLIANCE STILL REPORTING A DEW POINT OF 67 DEGREES...WITH LOW TO MID 60S ELSEWHERE. LATEST STORM PREDICTION CENTER MESOANALYSIS SHOWING CAPE ALREADY IN MOST OF THE PANHANDLE OF 4500 TO 5000 J/KG. ALL THAT IS NEEDED IS A LIFTING MECHANISM AND THAT IS DEVELOPING. A DRY LINE LAYS ACROSS EXTREME SOUTHEASTERN WYOMING...ROUGHLY FROM JUST EAST OF CHEYENNE TO JUST WEST OF TORRINGTON AND THEN NORTHWEST TO DOUGLAS. BEHIND THIS LINE...DEWPOINTS HAVE FALLEN INTO THE 20S. ALONG THIS LINE...SEEING CU DEVELOPING ALONG THE LINE. HAVE A PRETTY GOOD CELL ALREADY DEVELOPING IN NORTHERN LARAMIE COUNTY AND SOUTHERN GOSHEN COUNTY. THIS IS MOST LIKELY THE START OF OUR EVENT. JUST RECEIVED A SWOMCD FROM SPC AT 113 PM STATING A WATCH IS LIKELY...SO ANOTHER HOUR OR SO...CONVECTION SHOULD INITIATE. LATEST HRRR COMPOSITE REFLECTIVITY FORECAST SHOWING THAT CELL IN SOUTHERN GOSHEN COUNTY TAKING OFF AROUND 3 PM. BY THAT TIME...LOW STRATUS SHOULD BE MIXED OUT OVER THE NORTHERN PANHANDLE. SUPER CELL THEN MOVES EAST INTO THE CENTRAL PANHANDLE. WITH SUCH LARGE CAPE...GOING TO SEE SOME VERY LARGE HAIL REPORTS. NAM/WRF FORECAST SOUNDINGS CONTINUE TO SHOW STRONGLY VEERING WINDS WITH NORTHEASTERLY TO EASTERLY SURFACE WINDS AND 35-40KT SOUTHWESTERLY WINDS AT 700MBS. MORE THAN ENOUGH SHEAR TO SUPPORT SUPERCELLS CONTINUING INTO THE PANHANDLE. LATEST NAM HELICITIES FOR LATER THIS AFTERNOON/EVENING SHOWING 150M2/S2...INCREASING TO OVER 300M2/S2 OVER CONVERSE AND NIOBRARA COUNTIES AFTER 00Z...SPREADING INTO THE NORTHERN PANHANDLE AFTERWARDS. LCLS QUITE LOW UP THERE AS WELL...SO THE TORNADO THREAT WILL LIKELY BE FROM 23Z THROUGH MAYBE 02 TO 03Z TIME FRAME. SEVERE THUNDERSTORMS COULD LAST WELL INTO THE EVENING AND OVERNIGHT HOURS IN THE PANHANDLE. FOR SATURDAY...PRETTY MUCH A REPEAT OF TODAY WITH SEVERE THUNDERSTORMS OVER EAST CENTRAL WYOMING AND NEBRASKA PANHANDLE. SHOULD BEGIN TO SEE A DECREASE IN LOW LEVEL MOISTURE SUNDAY AS WINDS SHIFT TO THE SOUTHWEST. COULD STILL SEE SOME SEVERE THUNDERSTORMS IN THE PANHANDLE SUNDAY AFTERNOON. .LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 300 PM MDT FRI JUN 21 2013 DUE TO THE THREAT OF SEVERE WEATHER THIS AFTERNOON...WILL KEEP LONG TERM DISCUSSION BRIEF SINCE NOT MUCH HAS CHANGED SINCE YESTERDAY. MODELS CONTINUING TO SHOW SOUTHWEST FLOW ALOFT AND RELATIVELY QUIET WEATHER FOR NEXT WEEK. THERE APPEARS TO BE LITTLE IN THE WAY OF RAINFALL CHANCES ACROSS SOUTHEAST WYOMING NEXT WEEK...WITH A SLIGHTLY BETTER CHANCE ACROSS WESTERN NEBRASKA ON MONDAY AHEAD OF A WEAK COOL FRONT. MODELS SHOW THIS PACIFIC FRONT SLIDING EASTWARD ACROSS THE NORTHERN ROCKIES MONDAY NIGHT AND INTO TUESDAY. THE GFS AND THE GEM HAVE TRENDED TOWARDS THE ECMWF SOLUTION...SHOWING THE FRONT STALLING FURTHER TO THE NORTH AS THE UPPER LEVEL TROUGH IS FURTHER NORTH AS WELL AND MORE PROGRESSIVE. THE MAIN IMPACT FROM THIS FRONT WILL BE WINDY CONDITIONS...MAINLY WEST OF THE LARAMIE RANGE ON MONDAY AND TUESDAY. TEMPERATURES WILL NOT LOWER MUCH...IF AT ALL...ESPECIALLY FURTHER SOUTH NEAR THE I80 CORRIDOR. THERE APPEARS TO BE A BETTER CHANCE OF TSTORMS AHEAD OF THIS FRONT ON MONDAY...AS A WEAK SHORTWAVE MOVES NORTHEAST ACROSS THE HIGH PLAINS. INCREASED POP MONDAY AND MONDAY EVENING MAINLY ACROSS WESTERN NEBRASKA. AFTER THAT...MODELS ALL INDICATE A STRONG UPPER LEVEL HIGH DEVELOPING AND INTENSIFYING NEAR THE FOUR CORNERS REGION BY WEDNESDAY AND THURSDAY. THIS WILL RESULT IN A PERIOD OF LIGHT WINDS BUT ALSO VERY WARM OR HOT TEMPERATURES THROUGH LATE NEXT WEEK. WITH THE EXCEPTION OF MONDAY...KEPT POP BELOW 10 PERCENT THROUGH THE WEEK. HIGH TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL AND GENERALLY IN THE 80S AND 90S. THIS UPPER LEVEL HIGH WILL BEGIN TO DRIFT WESTWARD BY LATE IN THE WEEK...ALLOWING A CANADIAN COLD FRONT TO PUSH SOUTH. THIS MAY INCREASE PRECIPITATION AND TSTORM CHANCES BY NEXT WEEKEND DUE FAVORABLE EASTERLY FLOW BEHIND THE BOUNDARY. && .AVIATION...(FOR THE 00Z TAF ISSUANCE) VFR CONDITIONS EXPECTED ALONG AND WEST OF INTERSTATE 25 THROUGH TONIGHT FOR SOUTHEAST WYOMING...ALTHOUGH SOME LOW CIGS MAY DEVELOP NEAR THE CHEYENNE RIDGE INCLUDING KCYS AFTER 09Z. STRONG TO SEVERE THUNDERSTORMS WILL CONTINUE EARLY THIS EVENING ACROSS WESTERN NEBRASKA AND EXTREME EASTERN WYOMING. ERRATIC GUSTY WINDS UP TO 50 MPH...HAIL...AND IFR CONDITIONS HAVE BEEN REPORTED LATE THIS AFTERNOON...AND MAY CONTINUE WITH THESE THUNDERSTORMS EAST OF A LINE FROM KIMBALL NEBRASKA TO LUSK WYOMING. THUNDERSTORMS WILL LINGER THROUGH LATE TONIGHT BEFORE PUSHING EAST OF THE AREA BY MIDNIGHT. IFR CONDITIONS IN LOW CIGS AND FOG ARE EXPECTED TO RETURN AFTER MIDNIGHT ACROSS THE HIGH PLAINS OF WESTERN NEBRASKA AND PORTIONS OF SOUTHEAST WYOMING. && .FIRE WEATHER... ISSUED AT 300 PM MDT FRI JUN 21 2013 DRY AND BREEZY CONDITIONS CONTINUE ALONG AND WEST OF THE LARAMIE RANGE THIS AFTERNOON. TO THE EAST IN THE PANHANDLE AND UP OVER NIOBRARA COUNTY...HIGH HUMIDITIES WILL LEAD TO SEVERE THUNDERSTORMS LATER THIS AFTERNOON AND EVENING. HUMIDITIES OUT WEST ONCE AGAIN IN THE SINGLE DIGITS WITH WIND GUSTS FROM THE SOUTHWEST AT 30 TO 35 MPH. WINDS WILL EASE AFTER SUNSET. CONDITIONS LOOK TO REPEAT FOR SATURDAY AND TO A LESSER EXTENT ON SUNDAY AFTERNOON. STRONG WINDS WILL CONTINUE NEXT WEEK...PARTICULARLY MONDAY NIGHT INTO TUESDAY WITH WIND GUSTS EXCEEDING 40 MPH POSSIBLE OUT WEST. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...HAHN SHORT TERM...CLAYCOMB LONG TERM...TJT AVIATION...TJT FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1038 PM MDT SUN JUN 23 2013 .UPDATE... ISSUED AT 447 PM MDT SUN JUN 23 2013 UPDATED TO ISSUE A SEVERE THUNDERSTORM WATCH FOR AREAS EAST OF A LINE FROM COLORADO SPRINGS TO SPRINGFIELD. THIS WATCH GOES THROUGH MIDNIGHT. THE MAIN THREATS WILL BE LIGHTNING...DAMAGING OUTFLOW WIND GUSTS AND HAIL TO ONE INCH IN DIAMETER. MOZLEY && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 227 PM MDT SUN JUN 23 2013 ...CONTINUED DANGEROUS FIRE WEATHER CONDITIONS... CURRENTLY...SMOKE FROM THE WEST FORK COMPLEX IS STARTING TO SHIFT EAST ACROSS THE SAN LUIS VALLEY AND SHOULD CONTINUE TO PUSH EAST THROUGH THE EVENING. RADAR HAS BEEN PRETTY QUIET WITH A FEW CELLS BUBBLING NEAR THE SPANISH PEAKS/WALSENBURG AREA. SOUTHEASTERLY SURFACE FLOW HAS KEPT MOISTURE IN PLACE ACROSS THE PLAINS WITH DEW POINTS IN THE 40S TO MID 50S. TEMPERATURES ARE WARM WITH UPPER 80S TO LOWER 90S FOR THE LOWER ELEVATIONS. TONIGHT...MAIN CONCERN FOR THIS EVENING WILL BE THE POTENTIAL FOR SEVERE THUNDERSTORMS ACROSS THE PLAINS. CUMULUS HAVE BEEN PERCOLATING ACROSS THE RAMPART RANGE AND EASTERN MOUNTAINS THIS AFTERNOON AND AS AN UPPER LEVEL DISTURBANCE MOVES THROUGH THE SOUTHWEST FLOW ALOFT...IT WILL LIKELY TRIGGER ISOLATED THUNDERSTORMS. FOLLOWED A BLEND OF THE WRF SOLUTIONS AND HRRR WHICH DEVELOP SPOTTY CONVECTION FROM COLORADO SPRINGS...SOUTHEAST TO SPRINGFIELD AND TRACK THEM EAST ACROSS THE PLAINS THROUGH 05Z. UPDRAFT HELICITY VALUES ARE WEAK BASED ON THE NSSL WRF SOLUTION AND SHEARS ARE ONLY RUNNING AROUND 30 KTS SO CURRENTLY THINKING THE MAIN THREATS WILL BE HAIL TO ONE INCH IN DIAMETER AND STRONG THUNDERSTORM OUTFLOW WINDS. THE TORNADO THREAT LOOKS TO REMAIN NORTH IN NORTHEAST COLORADO. EXPECT ALL ACTIVITY TO SHIFT EAST INTO KANSAS THROUGH 06Z WITH DRY CONDITIONS THE REST OF THE NIGHT. MONDAY...AN UPPER TROUGH WILL MOVE OUT OF THE PACIFIC NORTHWEST WHICH WILL INCREASE SOUTHWESTERLY FLOW ACROSS COLORADO. THIS WILL SET THE STAGE FOR WIDESPREAD EXTREME FIRE WEATHER CONDITIONS WITH WINDS GUSTING TO 30 TO 40 MPH...AND HUMIDITY VALUES WELL UNDER 10 PERCENT. EXTREME CAUTION IS ADVISED ACROSS ALL OF SOUTHERN COLORADO...BUT PARTICULARLY OVER THE MOUNTAIN REGIONS AND AREAS ALONG AND WEST OF I-25. THE STRONG WINDS SHOULD ALSO ALLOW TEMPERATURES TO WARM QUICKLY INTO TO THE UPPER 90S TO LOWER 100S ACROSS THE PLAINS. SMOKE FROM AREA FIRES WILL SPREAD ACROSS MUCH OF THE AREA BY THE AFTERNOON WITH REDUCED VISIBILITIES AND POOR AIR QUALITY. MOZLEY .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 227 PM MDT SUN JUN 23 2013 THERE COULD BE A FEW SHOWERS/TSTMS ALONG THE ERN BORDER EARLY MON EVENING...BUT WL LEAVE THE FORECAST DRY OUT THERE FOR NOW. DRY WESTERLY FLOW IS EXPECTED OVR THE FORECAST AREA ON TUE. IT LOOKS LIKE LOW LEVEL MSTR OVR THE ERN SAN JUAN AND LA GARITA MTNS MAY BE A LITTLE HIGHER ON TUE...KEEPING MIN RH VALUES HIGH ENOUGH THAT A FIRE WX HIGHLIGHT SHOULD NOT BE NEEDED FOR THAT AREA. HOWEVER THERE IS A CHANCE THAT THE WINDS WL BE STRONG ENOUGH...ALONG WITH DRY ENOUGH HUMIDITIES OVER THE SAN LUIS VALLEY (FIRE ZONE 224) AND ALONG THE SANGRE DE CRISTO MTNS (FIRE ZONE 225)...TO WARRANT A FIRE WEATHER WATCH. THE REST OF THE AREA SHOULD NOT HAVE STRONG ENOUGH WINDS TO WARRANT A FIRE HIGHLIGHT. FOR WED AN UPR RIDGE CENTER IS EXPECTED TO BE OVR THE WEST CENTRAL NM...WITH THE FLOW ALOFT OVR THE FORECAST AREA BECOMING MORE NORTHWESTERLY. STILL LOOKS DRY ACRS THE AREA...WITH MAYBE JUST A COUPLE SHOWERS/TSTMS POPPING UP OVR SOME MTN LOCATIONS. THE UPR RIDGE THEN REMAINS OVR THE AREA THU THRU SAT WITH MODELS INDICATING SOME MSTR TRAPPED UNDER THE RIDGE AND THE POTENTIAL FOR JUST A FEW SHOWERS/TSTMS OVR AND NR THE MTNS. THE GFS SHOWS THE POTENTIAL FOR A WEATHER SYSTEM MOVING BY TO THE NORTH SAT NIGHT/SUN FLATTENING THE RIDGE AND SENDING A FRONT INTO THE AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1031 PM MDT SUN JUN 23 2013 THE MAIN AVN CONCERN TOMORROW WILL BE INCREASED SOUTHWEST WINDS OVER THE AREA FROM LATE MORNING THROUGH EARLY EVENING. WINDS COULD GUST IN THE 30-40 MPH RANGE BY LATE AFTERNOON... PARTICULARLY AT KALS AND KCOS. THE SOUTHWEST WINDS ALOFT WILL ALSO LEAD TO INCREASED SMOKE AT ALL TERMINALS IN THE AFTERNOON AND EVENING. DEPENDING ON HOW ACTIVE THE WEST FORK FIRE COMPLEX GETS...VISIBILITY MAY DROP TO MVFR OR LOWER AGAIN BY EARLY EVENING. ROSE && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 11 AM TO 8 PM MDT MONDAY FOR COZ220>230. FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR COZ224-225. && $$ UPDATE...MOZLEY SHORT TERM...MOZLEY LONG TERM...28 AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
319 AM CDT MON JUN 24 2013 .DISCUSSION... 723 PM CDT MADE MINOR TWEAKS TO THE GOING FORECAST. CONVECTION HAS SUBSIDED WITH SHOWERS FROM CHICAGO THROUGH STREATOR. EXPECTING THE SHOWERS TO SLOWLY WEAKEN AND MOVE EASTWARD...PRODUCING UP TO AN ADDITIONAL TENTH OF AN INCH OF PRECIP. THE CONVECTIVE OUTFLOW COOLED AREAS BUT MOST PLACES HAVE REBOUNDED...SO ADJUSTED TEMPS TRENDS BUT DID NOT MAKE MAJOR CHANGES TO LOW TEMPS TONIGHT. AS FAR AS PRECIP CHANCES THROUGH THE REST OF THE NIGHT...MADE MINOR ADJUSTMENTS BUT THE OVERALL PICTURE REMAINS THE SAME. EXPECTING CONVECTION TO REFIRE IN THE FOUR CORNERS AREA OF NE/IA/MO/KS AND SPREAD ACROSS IA OVERNIGHT. STEERING FLOW WOULD DIRECT THE STORMS TO THE EAST WITH STORMS ENTERING AREAS ALONG AND WEST OF THE I-39 CORRIDOR AROUND/AFTER 09Z. HOWEVER CONFIDENCE IS LOW TO MEDIUM IN HOW CONVECTION WILL EVOLVE AND LOW IN TIMING. HEAVY RAIN IS A DEFINITE CONCERN...BUT DUE TO LOW CONFIDENCE IN THE CONVECTIVE EVOLUTION I WILL HOLD OFF ISSUING A FLASH FLOOD WATCH. LIGHTNING...GUSTY WINDS...AND SMALL HAIL ARE ALSO POSSIBLE...BUT THINKING SEVERE WEATHER WILL BE ISOLATED AT BEST DUE TO THE ELEVATED NATURE OF THE STORMS. JEE //PREV DISCUSSION... 304 PM CDT SHOWER/THUNDER CHANCES REMAIN THE BIGGEST FORECAST CHALLENGE FOLLOWED BY TEMPS WHICH MAY BE AFFECTED BY THE CONVECTION. AFTERNOON WATER VAPOR IMAGERY SHOWS ONE UPPER LEVEL LOW SPINNING OVER THE CENTRAL APPALACHIANS WHICH IS LOSING DEFINITION AS IS MOVES SLOWLY NORTHWARD. THE NEXT UPPER LOW IS SPINNING OVER THE SOUTHERN CANADIAN PRAIRIES WITH A TROUGH AXIS EXTENDING INTO THE DAKOTAS AND LIFTING NORTHEAST. THE UPPER FLOW IS LESS AMPLIFIED FURTHER SOUTH OF THE LOW ACROSS THE CENTRAL PLAINS BUT THERE ARE SEVERAL EMBEDDED WAVES THAT ARE TRANSLATING NORTHEAST AS WELL. THE NEXT UPPER LOW OF NOTE IS COMING ONSHORE OVER THE WEST COAST AND HELPING TO AMPLIFY A RIDGE OVER OREGON/WASHINGTON. ENERGY EMANATING FROM THIS TROUGH WILL BECOME A PLAYER IN OUR WEATHER LATER THIS WEEK. AT THE SURFACE...LOW PRESSURE IS POSITIONED OVER NORTHWEST MINNESOTA WITH WEAKER LOW PRESSURE SPREAD ACROSS THE PLAINS. A COOL FRONTAL BOUNDARY IS STRETCHED FROM THE MN LOW BUT HAS BECOME DIFFICULT TO IDENTIFY THANKS TO COLD POOLS FROM MORNING CONVECTION. THROUGH THIS EVENING...TOUGH FORECAST ONCE AGAIN IN TERMS OF CONVECTIVE POTENTIAL AND EVOLUTION THROUGH THE PERIOD. OUTFLOW BOUNDARY FROM EARLIER IOWA CONVECTION IS NOW PUSHING INTO THE WESTERN CWA TRIGGERING THUNDERSTORMS ALONG IT. A BETTER ORGANIZED COMPLEX OF STORMS HAS DEVELOPED FROM THE EARLIER CONVECTION BUT IS MOVING SOUTHEAST ACROSS NORTHERN MISSOURI INTO THE AXIS OF MUCH BETTER INSTABILITY AS WELL AS BETTER MID LEVEL MOISTURE ADVECTION. ADDITIONAL SCATTERED STORMS HAVE DEVELOPED OVER THE SOUTHERN CWA LIKELY IN BETTER CONJUNCTION WITH THE WEAKENING UPPER LOW OVER APPALACHIA. IN THE NEAR TERM...EXPECT THE OUTFLOW TO CONTINUE EASTWARD ACROSS THE CWA TRIGGERING SCATTERED STORMS THROUGH LATE AFTERNOON/EARLY EVENING. MESOANALYSIS SHOWS 2000+ J/KG OF MIXED LAYER CAPE OVER THE AREA SUPPORTING STRONG UPDRAFTS BUT DEEP LAYER SHEAR IS WEAK SO CORES SHOULD BE PRETTY PULSEY. LARGE HAIL AND LOCALLY HEAVY DOWNPOURS ARE THE MAIN CONCERN. GUSTY WINDS ARE ALSO POSSIBLE BUT RECENT AIRCRAFT SOUNDINGS FROM MDW DO NOT SHOW A TON OF DRY LOW LEVEL AIR AND RAP ANALYSIS OF DCAPE IS LOW AS WELL. WOULD EXPECT THAT THIS ACTIVITY WOULD WANE WITH SUNSET. REST OF TONIGHT AND MONDAY...ATTENTION TURNS TO ADDITIONAL CONVECTIVE POTENTIAL OVERNIGHT. WATER VAPOR SHOWS A WAVE OVER NE KS/NW MO WHICH APPEARS TO BE TURNING MORE EASTWARD IN THE LAST FEW SCANS. THIS IS LIKELY HELPING THE COMPLEX TAKING SHAPE OVER MO. SHORT TERM/HIGH RES GUIDANCE HAS BEEN ALL OVER THE PLACE WITH HOW CONVECTION EVOLVES THROUGH TONIGHT. THE MOIST SOUTHWESTERLY FLOW WILL CONTINUE ACROSS THE REGION TONIGHT AND THE EARLIER COLD FRONTAL BOUNDARY SEEMS TO BE DEVELOPING ONCE AGAIN ACROSS IOWA AS THE FLOW HAS SETTLED FROM EARLIER CONVECTION. THIS IS SUPPORTIVE OF NEW DEVELOPMENT TO THE WEST TONIGHT. THE OUTFLOW CURRENTLY WORKING INTO THE LOCAL AREA EXTENDS INTO WEST-CENTRAL ILLINOIS AND THERE ARE HINTS THAT THE SOUTHERN EXTENT OF IT AND LIKELY A BOUNDARY SET UP BY THE CURRENT COMPLEX MAY STALL OUT SOMEWHERE NOT FAR FROM THE SOUTHWESTERN CWA. IN ADDITION...THE KS/MO WAVE IS EXPECTED TO CROSS THIS SAME AREA TONIGHT WHICH IS ALSO EXPECTED TO BE IN AN AREA OF MID LEVEL WARM ADVECTION. THEREFORE IT IS POSSIBLE ROUNDS OF CONVECTION COULD DEVELOP TO THE SOUTHWEST OF THE AREA AND ROLL EASTWARD INTO THE SOUTHERN CWA OVERNIGHT. HAVE NOT MADE MUCH CHANGE TO OVERNIGHT POPS BUT DID INCREASE THEM SOMEWHAT OVER THE FAR SOUTH. AS FOR MONDAY...GUIDANCE REMAINS IN POOR AGREEMENT WITH TRACK OF POTENTIAL UPPER WAVES BUT WATER VAPOR DOES SHOW SOME SIGNS OF A WAVE COMING ACROSS THE FOUR CORNERS THIS AFTERNOON. THIS WOULD COME ACROSS THE REGION LATER MONDAY BUT IT IS NOT CLEAR IF IT WILL BE MORE FOCUSED TO THE NORTH OF THE AREA. WILL CONTINUE WITH MID CHANCE POPS WITH LATER IN THE DAY MORE FAVORED. PROVIDED THE LATER TIMING WORKS OUT THEN WE WILL HAVE A BETTER CHANCE TO WARM BUT THERE MAY BE CONVECTIVE DEBRIS AROUND SO WILL HOLD TEMPS INTO THE MID 80S FOR MOST AREAS. TUESDAY THROUGH SUNDAY...THE UPPER FLOW BECOMES LESS AMPLIFIED TUESDAY BUT WILL LIKELY STILL BE LITTERED WITH WAVES TRAVERSING IT. HOT AND HUMID AIR WILL STILL BE IN PLACE WITH PRECIPITABLE WATER VALUES HOVERING AROUND 1.75 INCHES. THESE FACTORS PROVIDE CONTINUED SUPPORT FOR THUNDERSTORM DEVELOPMENT BUT THERE IS NOT MUCH TO KEY IN ON FOR A COHERENT FORCING MECHANISM GIVEN THE LOW AMPLITUDE PATTERN. BY WEDNESDAY...THERE IS SOME AGREEMENT ON SURFACE LOW PRESSURE HAVING DEVELOPED ACROSS THE CANADIAN PRAIRIES WITH A TROUGH AXIS/FRONT EXTENDING INTO MINNESOTA AND IOWA...WITH A SECONDARY LOW POSSIBLY DEVELOPING ACROSS MINNESOTA. THE FRONT LOOKS TO CROSS THE AREA LATER WEDNESDAY BRINGING SHOWER AND STORM CHANCES WITH IT. UPPER RIDGING WILL BE BUILDING ACROSS THE WESTERN U.S. AND HIGH PLAINS WITH A WAVE ORIGINATING FROM THE TROUGH OFF THE WEST COAST OVERTOPPING THE RIDGE ACROSS THE CANADIAN ROCKIES AND DROPPING SOUTHEASTWARD INTO THE GREAT LAKES WHILE AMPLIFYING LATE IN THE WEEK. GFS AND ECMWF DIFFER ON HOW QUICKLY THIS OCCURS BUT THE SIGNAL HAS BEEN CONSISTENT OVERALL. THIS WILL BRING A SHIFT TO NORTHWESTERLY AT THE SURFACE AND ALOFT LATE IN THE WEEK AND NOTICEABLY COOLER TEMPERATURES BY SATURDAY OR SO. LOW POPS WILL CONTINUE WITH THE FLOW CONTINUING TO FAVOR WEAK SHORTWAVE PASSAGES. HIGH TEMPS WILL LIKELY HOVER AROUND 90 TUESDAY AND WEDNESDAY ASSUMING CONVECTION OR CONVECTIVE DEBRIS IS NOT AN ISSUE...WHICH WOULD SIGNIFICANTLY LOWER HIGHS IF IT IS. WITH THE PASSAGE OF THE SYSTEM LATER WEDNESDAY COOLER MID LEVEL AIR WILL FILTER IN KEEPING HIGHS BACK IN THE 80S WITH UPPER 70S POSSIBLE FRIDAY AND SATURDAY. MDB && .HYDROLOGY... 745 PM CDT THE CONVECTIVE ACTIVITY THIS EVENING PRODUCED ISOLATED AREAS OF 2+ INCHES OF RAIN AND A BAND OF 1+ INCHES OF RAIN ACROSS LA SALLE COUNTY. STILL CONSIDERED A FLASH FLOOD WATCH FOR THE WEST AND FAR SOUTHWEST CWA GIVEN THE RAINFALL OF THE PAST FEW DAYS. CONFIDENCE REMAINS LOW IN WHERE ORGANIZED CONVECTION WILL SET UP TONIGHT AND MONDAY SO WILL HOLD OFF UNTIL AREAS AND TIMING CAN BE BETTER DEFINED. JEE/MDB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * MAINLY SOUTHERLY WINDS ARND 10KT...OCCASIONAL GUSTS LATE MORNING/AFTN TO 20-24KT. IF TSRA DEVELOP WIND DIR COULD BECOME VRB FOR A PERIOD OF TIME. * PRECIP DEVELOPS...LOW COVERAGE EXPECTED LATE THIS MORNING THRU AFTN. BEACHLER //DISCUSSION...UPDATED 06Z... SIMILAR SETUP AGAIN TODAY AS HAS BEEN THE CASE THE PAST FEW DAYS...ISOLATED TSRA DEVELOPING. EXPECT MAINLY SOUTHERLY WINDS ARND 10KT INCREASING WITH GUSTS TO 20-24KT BY LATE MORNING THRU THE AFTN. THE WILDCARD WILL BE CLOUD COVER WHICH COULD LIMIT HOW GUSTY WINDS BECOME. THEN THE FOCUS TURNS TOWARDS TIMING OF PRECIP DEVELOPMENT. EARLY THIS MORNING AN AREA OF SHRA/TSRA WAS PULSING NORTHEAST...HOWEVER IT DOES NOT APPEAR THIS SHOULD HOLD TOGETHER AND IMPACT THE TAF SITES. LATER THIS MORNING A WEAK WAVE DOES TRY TO PUSH OVERHEAD...AND EXPECT SLOW DEVELOPMENT TO THUNDERSTORMS MIDDAY/AFTN. THE COVERAGE SHOULD BE MINIMAL AND MORE OF A PULSE LIKE ENVIRONMENT...WHICH COULD POSE A CHALLENGE FOR A FEW SITES SEEING CHAOTIC WIND DIR/SPEEDS FOR A BRIEF PERIOD OF TIME IN/AROUND THUNDERSTORMS. WINDS THEN BEGIN TO DIMINISH TO ARND 5-7KT OVERNIGHT INTO EARLY TUE...WITH POSSIBLY A REPEAT WITH ISOLATED SHRA/TSRA IN THE AREA AFT 06Z TUE. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA DEVELOPMENT. * HIGH CONFIDENCE IN MAINLY SOUTHERLY WIND SPEEDS/GUSTS. * MEDIUM CONFIDENCE VFR CONDS WILL PREVAIL. BEACHLER //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH FRIDAY...PERIODIC CHANCES OF TSRA. SATURDAY...CHANCE OF SHRA. RODRIGUEZ && .MARINE... 312 AM CDT MAIN MARINE CONCERNS IS ON DENSE FOG FOR THE NORTHERN HALF OF THE LAKE...AND POSSIBLY LINGERING THROUGH MID-WEEK. PERIODIC THUNDERSTORMS CHANCES ARE EXPECTED THROUGH THE NEXT SEVERAL DAYS AS WELL. MINIMAL CHANGES TO PREVIOUS FORECASTS...WITH BROAD RIDGE OF HIGH PRESSURE ANCHORED OVER THE WESTERN ATLANTIC OCEAN...BEGINNING TO DRIFT SOUTH THROUGH THE NEXT FEW DAYS. A LOW PRESSURE NEAR LAKE WINNIPEG WILL DRIFT EAST TOWARDS JAMES BAY TUESDAY MORNING...WHILE ANOTHER AREA OF LOW PRESSURE STRETCHING FROM SOUTHERN CANADA TO THE CENTRAL PLAINS BEGINS TO DRIFT NORTHEAST WEDNESDAY. THE COMBINATION OF THE WESTERN ATLANTIC OCEAN RIDGE AND CENTRAL PLAINS/CANADIAN LOW...WILL MAINTAIN A GENERALLY SOUTHERLY FLOW OF WARM/MOIST AIR ACROSS LAKE MICHIGAN. THIS SHOULD KEEP ANY FOG OUT OF THE SOUTHERN ZONES...HOWEVER AREAS OF DENSE FOG WILL REDEVELOP FOR THE NORTHERN HALF AND COULD EASILY PERSIST THROUGH MID-WEEK. HAVE EXTENDED THE MARINE FOG ADVISORY THROUGH DAYBREAK TUE...BUT COULD EASILY SEE THIS NEEDING TO BE EXTENDED EVEN FURTHER OUT IN TIME. WINDS WILL GENERALLY BE SOUTHERLY TO AT TIMES SOUTHWESTERLY...WITH SPEEDS OVERNIGHT IN A 10-15KT RANGE AND INCREASING TO 15 TO 20 KT DURING THE DAY. WITH ANY THUNDERSTORMS THAT DEVELOP...WINDS AND WAVES WILL EASILY BE HIGHER IN AND AROUND THESE THUNDERSTORMS. A COLD FRONT PUSHES ACROSS THE LAKE DURING WEDNESDAY NIGHT...SHIFTING WINDS TO OUT OF THE WEST. A SECONDARY COLD FRONT WILL MOVE ACROSS THE LAKE AND SHIFT WINDS TO OUT OF THE NORTHWEST DURING LATER THURSDAY AND THURSDAY NIGHT. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-ILZ019 UNTIL 7 PM MONDAY. IN...NONE. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 10 AM TUESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1259 AM CDT MON JUN 24 2013 .DISCUSSION... 723 PM CDT MADE MINOR TWEAKS TO THE GOING FORECAST. CONVECTION HAS SUBSIDED WITH SHOWERS FROM CHICAGO THROUGH STREATOR. EXPECTING THE SHOWERS TO SLOWLY WEAKEN AND MOVE EASTWARD...PRODUCING UP TO AN ADDITIONAL TENTH OF AN INCH OF PRECIP. THE CONVECTIVE OUTFLOW COOLED AREAS BUT MOST PLACES HAVE REBOUNDED...SO ADJUSTED TEMPS TRENDS BUT DID NOT MAKE MAJOR CHANGES TO LOW TEMPS TONIGHT. AS FAR AS PRECIP CHANCES THROUGH THE REST OF THE NIGHT...MADE MINOR ADJUSTMENTS BUT THE OVERALL PICTURE REMAINS THE SAME. EXPECTING CONVECTION TO REFIRE IN THE FOUR CORNERS AREA OF NE/IA/MO/KS AND SPREAD ACROSS IA OVERNIGHT. STEERING FLOW WOULD DIRECT THE STORMS TO THE EAST WITH STORMS ENTERING AREAS ALONG AND WEST OF THE I-39 CORRIDOR AROUND/AFTER 09Z. HOWEVER CONFIDENCE IS LOW TO MEDIUM IN HOW CONVECTION WILL EVOLVE AND LOW IN TIMING. HEAVY RAIN IS A DEFINITE CONCERN...BUT DUE TO LOW CONFIDENCE IN THE CONVECTIVE EVOLUTION I WILL HOLD OFF ISSUING A FLASH FLOOD WATCH. LIGHTNING...GUSTY WINDS...AND SMALL HAIL ARE ALSO POSSIBLE...BUT THINKING SEVERE WEATHER WILL BE ISOLATED AT BEST DUE TO THE ELEVATED NATURE OF THE STORMS. JEE //PREV DISCUSSION... 304 PM CDT SHOWER/THUNDER CHANCES REMAIN THE BIGGEST FORECAST CHALLENGE FOLLOWED BY TEMPS WHICH MAY BE AFFECTED BY THE CONVECTION. AFTERNOON WATER VAPOR IMAGERY SHOWS ONE UPPER LEVEL LOW SPINNING OVER THE CENTRAL APPALACHIANS WHICH IS LOSING DEFINITION AS IS MOVES SLOWLY NORTHWARD. THE NEXT UPPER LOW IS SPINNING OVER THE SOUTHERN CANADIAN PRAIRIES WITH A TROUGH AXIS EXTENDING INTO THE DAKOTAS AND LIFTING NORTHEAST. THE UPPER FLOW IS LESS AMPLIFIED FURTHER SOUTH OF THE LOW ACROSS THE CENTRAL PLAINS BUT THERE ARE SEVERAL EMBEDDED WAVES THAT ARE TRANSLATING NORTHEAST AS WELL. THE NEXT UPPER LOW OF NOTE IS COMING ONSHORE OVER THE WEST COAST AND HELPING TO AMPLIFY A RIDGE OVER OREGON/WASHINGTON. ENERGY EMANATING FROM THIS TROUGH WILL BECOME A PLAYER IN OUR WEATHER LATER THIS WEEK. AT THE SURFACE...LOW PRESSURE IS POSITIONED OVER NORTHWEST MINNESOTA WITH WEAKER LOW PRESSURE SPREAD ACROSS THE PLAINS. A COOL FRONTAL BOUNDARY IS STRETCHED FROM THE MN LOW BUT HAS BECOME DIFFICULT TO IDENTIFY THANKS TO COLD POOLS FROM MORNING CONVECTION. THROUGH THIS EVENING...TOUGH FORECAST ONCE AGAIN IN TERMS OF CONVECTIVE POTENTIAL AND EVOLUTION THROUGH THE PERIOD. OUTFLOW BOUNDARY FROM EARLIER IOWA CONVECTION IS NOW PUSHING INTO THE WESTERN CWA TRIGGERING THUNDERSTORMS ALONG IT. A BETTER ORGANIZED COMPLEX OF STORMS HAS DEVELOPED FROM THE EARLIER CONVECTION BUT IS MOVING SOUTHEAST ACROSS NORTHERN MISSOURI INTO THE AXIS OF MUCH BETTER INSTABILITY AS WELL AS BETTER MID LEVEL MOISTURE ADVECTION. ADDITIONAL SCATTERED STORMS HAVE DEVELOPED OVER THE SOUTHERN CWA LIKELY IN BETTER CONJUNCTION WITH THE WEAKENING UPPER LOW OVER APPALACHIA. IN THE NEAR TERM...EXPECT THE OUTFLOW TO CONTINUE EASTWARD ACROSS THE CWA TRIGGERING SCATTERED STORMS THROUGH LATE AFTERNOON/EARLY EVENING. MESOANALYSIS SHOWS 2000+ J/KG OF MIXED LAYER CAPE OVER THE AREA SUPPORTING STRONG UPDRAFTS BUT DEEP LAYER SHEAR IS WEAK SO CORES SHOULD BE PRETTY PULSEY. LARGE HAIL AND LOCALLY HEAVY DOWNPOURS ARE THE MAIN CONCERN. GUSTY WINDS ARE ALSO POSSIBLE BUT RECENT AIRCRAFT SOUNDINGS FROM MDW DO NOT SHOW A TON OF DRY LOW LEVEL AIR AND RAP ANALYSIS OF DCAPE IS LOW AS WELL. WOULD EXPECT THAT THIS ACTIVITY WOULD WANE WITH SUNSET. REST OF TONIGHT AND MONDAY...ATTENTION TURNS TO ADDITIONAL CONVECTIVE POTENTIAL OVERNIGHT. WATER VAPOR SHOWS A WAVE OVER NE KS/NW MO WHICH APPEARS TO BE TURNING MORE EASTWARD IN THE LAST FEW SCANS. THIS IS LIKELY HELPING THE COMPLEX TAKING SHAPE OVER MO. SHORT TERM/HIGH RES GUIDANCE HAS BEEN ALL OVER THE PLACE WITH HOW CONVECTION EVOLVES THROUGH TONIGHT. THE MOIST SOUTHWESTERLY FLOW WILL CONTINUE ACROSS THE REGION TONIGHT AND THE EARLIER COLD FRONTAL BOUNDARY SEEMS TO BE DEVELOPING ONCE AGAIN ACROSS IOWA AS THE FLOW HAS SETTLED FROM EARLIER CONVECTION. THIS IS SUPPORTIVE OF NEW DEVELOPMENT TO THE WEST TONIGHT. THE OUTFLOW CURRENTLY WORKING INTO THE LOCAL AREA EXTENDS INTO WEST-CENTRAL ILLINOIS AND THERE ARE HINTS THAT THE SOUTHERN EXTENT OF IT AND LIKELY A BOUNDARY SET UP BY THE CURRENT COMPLEX MAY STALL OUT SOMEWHERE NOT FAR FROM THE SOUTHWESTERN CWA. IN ADDITION...THE KS/MO WAVE IS EXPECTED TO CROSS THIS SAME AREA TONIGHT WHICH IS ALSO EXPECTED TO BE IN AN AREA OF MID LEVEL WARM ADVECTION. THEREFORE IT IS POSSIBLE ROUNDS OF CONVECTION COULD DEVELOP TO THE SOUTHWEST OF THE AREA AND ROLL EASTWARD INTO THE SOUTHERN CWA OVERNIGHT. HAVE NOT MADE MUCH CHANGE TO OVERNIGHT POPS BUT DID INCREASE THEM SOMEWHAT OVER THE FAR SOUTH. AS FOR MONDAY...GUIDANCE REMAINS IN POOR AGREEMENT WITH TRACK OF POTENTIAL UPPER WAVES BUT WATER VAPOR DOES SHOW SOME SIGNS OF A WAVE COMING ACROSS THE FOUR CORNERS THIS AFTERNOON. THIS WOULD COME ACROSS THE REGION LATER MONDAY BUT IT IS NOT CLEAR IF IT WILL BE MORE FOCUSED TO THE NORTH OF THE AREA. WILL CONTINUE WITH MID CHANCE POPS WITH LATER IN THE DAY MORE FAVORED. PROVIDED THE LATER TIMING WORKS OUT THEN WE WILL HAVE A BETTER CHANCE TO WARM BUT THERE MAY BE CONVECTIVE DEBRIS AROUND SO WILL HOLD TEMPS INTO THE MID 80S FOR MOST AREAS. TUESDAY THROUGH SUNDAY...THE UPPER FLOW BECOMES LESS AMPLIFIED TUESDAY BUT WILL LIKELY STILL BE LITTERED WITH WAVES TRAVERSING IT. HOT AND HUMID AIR WILL STILL BE IN PLACE WITH PRECIPITABLE WATER VALUES HOVERING AROUND 1.75 INCHES. THESE FACTORS PROVIDE CONTINUED SUPPORT FOR THUNDERSTORM DEVELOPMENT BUT THERE IS NOT MUCH TO KEY IN ON FOR A COHERENT FORCING MECHANISM GIVEN THE LOW AMPLITUDE PATTERN. BY WEDNESDAY...THERE IS SOME AGREEMENT ON SURFACE LOW PRESSURE HAVING DEVELOPED ACROSS THE CANADIAN PRAIRIES WITH A TROUGH AXIS/FRONT EXTENDING INTO MINNESOTA AND IOWA...WITH A SECONDARY LOW POSSIBLY DEVELOPING ACROSS MINNESOTA. THE FRONT LOOKS TO CROSS THE AREA LATER WEDNESDAY BRINGING SHOWER AND STORM CHANCES WITH IT. UPPER RIDGING WILL BE BUILDING ACROSS THE WESTERN U.S. AND HIGH PLAINS WITH A WAVE ORIGINATING FROM THE TROUGH OFF THE WEST COAST OVERTOPPING THE RIDGE ACROSS THE CANADIAN ROCKIES AND DROPPING SOUTHEASTWARD INTO THE GREAT LAKES WHILE AMPLIFYING LATE IN THE WEEK. GFS AND ECMWF DIFFER ON HOW QUICKLY THIS OCCURS BUT THE SIGNAL HAS BEEN CONSISTENT OVERALL. THIS WILL BRING A SHIFT TO NORTHWESTERLY AT THE SURFACE AND ALOFT LATE IN THE WEEK AND NOTICEABLY COOLER TEMPERATURES BY SATURDAY OR SO. LOW POPS WILL CONTINUE WITH THE FLOW CONTINUING TO FAVOR WEAK SHORTWAVE PASSAGES. HIGH TEMPS WILL LIKELY HOVER AROUND 90 TUESDAY AND WEDNESDAY ASSUMING CONVECTION OR CONVECTIVE DEBRIS IS NOT AN ISSUE...WHICH WOULD SIGNIFICANTLY LOWER HIGHS IF IT IS. WITH THE PASSAGE OF THE SYSTEM LATER WEDNESDAY COOLER MID LEVEL AIR WILL FILTER IN KEEPING HIGHS BACK IN THE 80S WITH UPPER 70S POSSIBLE FRIDAY AND SATURDAY. MDB && .HYDROLOGY... 745 PM CDT THE CONVECTIVE ACTIVITY THIS EVENING PRODUCED ISOLATED AREAS OF 2+ INCHES OF RAIN AND A BAND OF 1+ INCHES OF RAIN ACROSS LA SALLE COUNTY. STILL CONSIDERED A FLASH FLOOD WATCH FOR THE WEST AND FAR SOUTHWEST CWA GIVEN THE RAINFALL OF THE PAST FEW DAYS. CONFIDENCE REMAINS LOW IN WHERE ORGANIZED CONVECTION WILL SET UP TONIGHT AND MONDAY SO WILL HOLD OFF UNTIL AREAS AND TIMING CAN BE BETTER DEFINED. JEE/MDB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * MAINLY SOUTHERLY WINDS ARND 10KT...OCCASIONAL GUSTS LATE MORNING/AFTN TO 20-24KT. IF TSRA DEVELOP WIND DIR COULD BECOME VRB FOR A PERIOD OF TIME. * PRECIP DEVELOPS...LOW COVERAGE EXPECTED LATE THIS MORNING THRU AFTN. BEACHLER //DISCUSSION...UPDATED 06Z... SIMILAR SETUP AGAIN TODAY AS HAS BEEN THE CASE THE PAST FEW DAYS...ISOLATED TSRA DEVELOPING. EXPECT MAINLY SOUTHERLY WINDS ARND 10KT INCREASING WITH GUSTS TO 20-24KT BY LATE MORNING THRU THE AFTN. THE WILDCARD WILL BE CLOUD COVER WHICH COULD LIMIT HOW GUSTY WINDS BECOME. THEN THE FOCUS TURNS TOWARDS TIMING OF PRECIP DEVELOPMENT. EARLY THIS MORNING AN AREA OF SHRA/TSRA WAS PULSING NORTHEAST...HOWEVER IT DOES NOT APPEAR THIS SHOULD HOLD TOGETHER AND IMPACT THE TAF SITES. LATER THIS MORNING A WEAK WAVE DOES TRY TO PUSH OVERHEAD...AND EXPECT SLOW DEVELOPMENT TO THUNDERSTORMS MIDDAY/AFTN. THE COVERAGE SHOULD BE MINIMAL AND MORE OF A PULSE LIKE ENVIRONMENT...WHICH COULD POSE A CHALLENGE FOR A FEW SITES SEEING CHAOTIC WIND DIR/SPEEDS FOR A BRIEF PERIOD OF TIME IN/AROUND THUNDERSTORMS. WINDS THEN BEGIN TO DIMINISH TO ARND 5-7KT OVERNIGHT INTO EARLY TUE...WITH POSSIBLY A REPEAT WITH ISOLATED SHRA/TSRA IN THE AREA AFT 06Z TUE. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA DEVELOPMENT. * HIGH CONFIDENCE IN MAINLY SOUTHERLY WIND SPEEDS/GUSTS. * MEDIUM CONFIDENCE VFR CONDS WILL PREVAIL. BEACHLER //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH FRIDAY...PERIODIC CHANCES OF TSRA. SATURDAY...CHANCE OF SHRA. RODRIGUEZ && .MARINE... 420 PM CDT A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE WESTERN ATLANTIC SOUTHWESTWARD ACROSS THE SOUTHEASTERN U.S. AND THE NORTHERN GULF OF MEXICO. THIS HIGH WILL BE MOVING ONLY VERY SLOWLY SOUTHEASTWARD TONIGHT THROUGH THURSDAY. LOW PRESSURE NEAR LAKE WINNIPEG WILL BE MOVING SLOWLY EASTWARD ACROSS ONTARIO...REACHING NEAR SOUTHERN JAMES BAY BY TUESDAY MORNING. THEN...AN AREA OF LOW PRESSURE STRETCHING FROM THE SOUTHERN CANADIAN PRAIRIE SOUTH ACROSS THE PLAINS WILL MOVE NORTHEAST DURING TUESDAY AND WEDNESDAY. WITH HIGH PRESSURE SITUATED FAR TO THE SOUTH THROUGH SOUTHEAST OF THE LAKE AND LOW PRESSURE FROM FAR WEST THROUGH NORTHWEST TONIGHT INTO THURSDAY...MODERATE TO FRESH WINDS WILL PERSIST OUT OF THE SOUTH TO SOUTHWEST. THIS PERSISTENT FLOW WILL KEEP VERY MOIST AIR ACROSS THE WESTERN GREAT LAKES REGION. WHILE MOST OF THE FOG HAD DISSIPATED ON NORTHERN LAKE MICHIGAN...WITH THE MOIST AIR AND COOL LAKE WATER FOG IS EXPECTED TO REDEVELOP TONIGHT AND BECOME DENSE IN AREAS. THE CURRENT DENSE FOG ADVISORY FOR NORTHERN LAKE MICHIGAN WILL LIKELY NEED TO BE EXTENDED INTO TUESDAY AND POSSIBLY WEDNESDAY AS THERE WILL BE NO CHANGE IN AIRMASS UNTIL A COLD FRONT PUSHES ACROSS THE LAKE DURING LATER WEDNESDAY AND WEDNESDAY NIGHT...SHIFTING WINDS TO OUT OF THE WEST. A SECONDARY COLD FRONT WILL MOVE ACROSS THE LAKE AND SHIFT WINDS TO OUT OF THE NORTHWEST DURING LATER THURSDAY AND THURSDAY NIGHT. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 7 AM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS TOPEKA KS
406 AM CDT MON JUN 24 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 352 AM CDT MON JUN 24 2013 ANOTHER DIFFICULT FORECAST AS MESOSCALE FEATURES CONTINUE TO DEFINE CONVECTIVE POTENTIAL...AND ARE DIFFICULT TO FORECAST MORE THAN A FEW HOURS OUT. FOR TODAY...SOUNDINGS SUGGEST WAVE LIFTING OUT OF OK/CTRL KS MAY SATURATE MID LEVELS ENOUGH TO SUPPORT SOME ISOLATED CONVECTION THIS MORNING...AND WILL LEAVE AN ISOLATED POP TO REFLECT THIS. HRRR MODEL...WHICH HAS PERFORMED WELL IN THE MORNING RUNS THIS WEEK...DEPICTS CONVECTIVE COMPLEX OVER SC NEBRASKA SLIDING SLIGHTLY TO THE SE AND BACK-BUILD INTO OUR FORECAST AREA LATER THIS MORNING. FRONTAL BOUNDARY HAS SHIFTED FARTHER NORTHWARD AND SUSPECT COMPLEX WILL STAY NORTH OF THE FA. ALSO SHOULD CONSIDER OUTFLOW MOVING SE OUT OF IOWA CONVECTION AND WHERE THAT MAY END UP ON THE KS/MO BORDER THIS AFTERNOON. AT THIS TIME LESS CINH AND BETTER DYNAMICS COME TOGETHER NORTH OF THE AREA. HAVE STARTED WITH A SILENT POP IN THE NE COUNTIES AND WILL MONITOR FOR DEVELOPMENT. BREEZY SOUTHERLY WINDS WILL BE NEAR BUT GENERALLY BELOW WIND ADVISORY CRITERIA AND WILL HOLD OFF FOR NOW. HIGHS TODAY IN THE 90S FOLLOWED BY WARM OVERNIGHT LOWS IN THE MIDDLE 70S. WITH ANOTHER COMPLEX MOVING NORTH OF THE FORECAST AREA LATE MONDAY INTO EARLY TUESDAY...WILL CARRY A SLIGHT CHANCE POP ACROSS THE FAR NORTHERN COUNTIES AS MAY SEE SOME LATE NIGHT COLD POOL LLJ INTERACTION. 67 .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 352 AM CDT MON JUN 24 2013 MID RANGE AND EXTENDED FORECAST (TUESDAY THROUGH SUNDAY)... WARM...MUGGY...AND DRY CONDITIONS EXPECTED TO PERSIST THROUGH MOST OF THE MID RANGE AND EXTENDED PERIOD. FOR TUESDAY AND WEDNESDAY THE MID LEVEL RIDGE GETS SOMEWHAT FLATTENED OUT AND DEAMPLIFIED AS THE HIGH PRESSURE EXPANDS ACROSS THE SOUTHERN PLAINS. EVENTUALLY...BY MID WEEK THE RIDGE WILL BECOME CENTERED OVER THE FOUR CORNERS REGION OF THE US...AND WILL BECOME MOVE AMPLIFIED AS THE WEEK PROGRESSES. WITH THE EASTERN EDGE OF THE HIGH PRESSURE DOME IN THE VICINITY OF NORTHEAST KANSAS EXPECT SOME MID LEVEL NWLY FLOW TO REMAIN OVER THE FORECAST AREA...WHICH WILL BRING THE POTENTIAL FOR MCS DEVELOPMENT WITHIN THE FLOW. FOR NOW WILL KEEP A MOSTLY DRY FORECAST THROUGH THE EXTENDED PERIOD...WITH THE LONE EXCEPTION OF THURSDAY NIGHT WHERE THE ECMWF AND GFS AGREE ON THUNDERSTORMS DEVELOPING ALONG THE PERIPHERY OF THE RIDGE AND DROPPING SOUTH/SOUTHEASTWARD OUT OF SE NEBRASKA INTO NE KANSAS. GIVEN THE LACK OF ANY STRONG SIGNAL OF OBVIOUS LIFTING MECHANISMS WILL ONLY GO WITH A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS FOR THAT PERIOD. OTHERWISE...EXPECT A RATHER WARM AND MUGGY PERIOD FOR TUES THROUGH THURS AS DAY TIME HIGHS WILL GENERALLY REACH THE MID TO UPPER 90S...WITH HEAT INDEX VALUES RANGING BETWEEN 100 AND 105 ACROSS MOST OF THE FORECAST AREA. TEMPERATURES WILL COOL OFF A BIT FOR THE END OF THE WORK WEEK THROUGH THE WEEKEND...AS A SURFACE HIGH BRINGS COOLER AIR INTO NORTHEAST KANSAS. EXPECT TEMPS FOR FRIDAY THROUGH MONDAY TO BE IN THE UPPER 80S TO PERHAPS THE MID 90S. JL && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1101 PM CDT SUN JUN 23 2013 VFR IS THE PREVAILING CATEGORY AT KTOP/KFOE/KMHK AS SOUTH SOUTHEAST WINDS REMAIN STEADY AROUND 10 KTS. CONVECTION FORMING OVER FAR EASTERN COLORADO MAY ORGANIZE INTO A THUNDERSTORM COMPLEX AND ENTER THE AREA AFT 11Z. INSERTED A VCTS ATTM AS EXACT TIMING OF THE TSRA IS STILL UNCERTAIN. GUSTS INCREASE UP TO 30 KTS AFT 14Z MONDAY. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CRAVEN LONG TERM...LEIGHTON AVIATION...BOWEN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
535 AM EDT MON JUN 24 2013 .SYNOPSIS... UNSETTLED CONDITIONS WITH SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST THROUGH MID WEEK.&& .NEAR TERM /THROUGH TONIGHT/... UPDATE 0530L: DECAYING MCS HAS REACHED OUR FAR WRN ZONES ATTM. THIS A LITTLE FASTER THAN ERLYR EXPECTED SO HAVE ADJUSTED POPS FOR CURRENT AND EXPECTED TRENDS THRU THE AM HRS. REMAINDER OF THE FCST UNCHANGED... DECAYING MCS OVR SRN QUEBEC ATTM ABOUT TO ENTER FAR WRN MAINE... OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ACROSS THE FA ATTM W/ SOME FOG ACROSS THE N. NOT MUCH CHANGE IN THE OVERALL PTRN ACROSS OUR AREA LAST 24 HRS AT LEAST IN THE UPPER LEVELS OF THE ATMOS AS BRISK WNW FLOW ALOFT PERSISTS W/ OCNL DISTURBANCES EMBEDDED IN THIS FLOW. IN THE LOWER LEVELS - A VRY WARM AND HUMID SWRLY FLOW IS NOW IN PLACE ACROSS THE ENTIRE REGION W/ TDS GENERALLY IN THE LOWER TO MID 60S. THE DECAYING MCS IS SHOWN BY THE SHORTER TERM MODELS SUCH AS THE RUC TO CONT TO MV ESEWRD AND HOLD TOGETHER ENUF TO HAVE SOME IMPACT ON OUR WRN ZNS ERLY TDY THEN ACROSS OUR S CENTRAL ZNS THRU THE AM HRS AND POPS ACROSS THESE AREAS WILL REFLECT THIS. OTHERWISE...ANOTHER UPPER DISTURBANCE IS FCST TO SLIDE ESEWRD ACROSS THE FA LATER TDY AND PROVIDE ANOTHER UPTICK IN SHOWERS/TSTMS. UNLIKE SUN...WHERE MOST ACTION WAS S OF THE AREA - APPEARS TDY THAT THINGS HAVE SHIFTED A LITTLE FURTHER N W/ THE INTRUSION OF THE WARMER AND MORE HUMID AIR. AS A RESULT...WILL CARRY MAINLY CHC POPS ACROSS THE REMAINDER OF THE FA TDY INTO THIS EVE W/ ACTIVITY EXPECTED TO AGAIN WEAKEN/DISSIPATE LATER THIS EVE AS THIS UPPER DISTURBANCE MVS AWAY FROM THE REGION. THIS WILL SET THE STAGE FOR MORE PATCHY FOG W/ THE FOG PROBABLY A LITTLE MORE WDSPRD THAN THIS AM W/ THE HUMID AIRMASS PERSISTING. TEMPS TDY WILL BE A LITTLE TRICKY... CLDS AND SHOWERS WILL NO DOUBT HAVE SOME IMPACT AND PROBABLY KEEP MOST AREAS FROM REACHING FULL POTENTIAL TDY. STILL...A LITTLE SUNSHINE FROM TIME TO TIME IS EXPECTED AND WILL GO A LONG WAY IN HEATING THINGS UP SO WILL HANG ONTO HIGHS INTO THE LOWER 80S N W/ MID TO PSBLY UPPER 80S CENTRAL AND INTERIOR DOWNEAST...&& .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... PERIOD WILL BEGIN WITH A SURFACE HIGH SETUP IN THE ATLANTIC AND BOUNDARY DRAPED JUST TO THE NORTH OF THE REGION. THE SURFACE HIGH WILL CONTINUE TO PUMP WARM AND MOIST AIR INTO THE REGION. GUIDANCE IS IN FAIR AGREEMENT WITH THE BOUNDARY AND SURFACE LOW BEGINNING TO DROP SOUTH THROUGH THE DAY ON TUESDAY. THIS COMBINED WITH BETTER UPPER LEVEL DYNAMICS WITH THE REGION LOCATED IN THE FAVORABLE RIGHT ENTRANCE REGION OF UPPER LEVEL JET ENHANCING DIVERGENCE ALOFT. ALSO WITH WARM AND MOIST UNSTABLE AIR IN PLACE CAPE VALUES WILL BE GENERALLY BETWEEN 500 TO 1500 J/KG. THESE DYNAMICS WILL MAKE IT POSSIBLE TO HAVE SOME MORE ENHANCED THUNDERSTORM ACTIVITY TUESDAY AFTERNOON AND EVENING. RIGHT NOW THINKING IS THERE WILL BE THE POTENTIAL FOR SMALL HAIL AND GUSTY WINDS BUT THIS MAY NEED TO BE ENHANCED FURTHER IF DYNAMICS CONTINUE TO COME TOGETHER. BEST CHANCES STILL LOOK TO BE ACROSS THE NORTHERN AND CENTRAL PORTIONS OF THE REGION WHERE BEST SUPPORTING DYNAMICS ARE PRESENT. THERE IS SOME MODEL DIVERGENCE FOR WEDNESDAY WITH THE MOST OF GUIDANCE WANTING TO KEEP THE LOW PRESSURE ACROSS THE REGION WHILE THE 23/12Z ECMWF WANTS TO KEEP IT DRIER. RIGHT NOW WILL KEEP DECENT CONSISTENCY WITH PREVIOUS FORECAST WITH MORE SHOWERY TYPE ACTIVITY. TEMPERATURES FOR WEDNESDAY LOOK TO BE COOLER ALTHOUGH THIS WILL BE HIGHLY DEPENDENT ON CLOUD COVER.&& .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE GUIDANCE IS STILL A BIT DIVERGENT IN THE BEGINNING OF THE LONG TERM PERIOD. THE 24/00Z GFS/GEM WANTS TO HOLD ON TO THE BOUNDARY AND SURFACE LOW A BIT LONGER THAN THE 23/12Z ECMWF FOR WEDNESDAY NIGHT. THEN WE WILL SEE ANOTHER STRONG UPPER LEVEL DISTURBANCE ACROSS THE GREAT LAKES CONTINUE TO PROGRESS EAST. ALL THE LONG RANGE GUIDANCE INDICATES THIS MOVING EAST BUT WITH SLIGHT DIFFERENCES IN TIMING. GENERALLY IT LOOKS LIKE THIS SYSTEM WILL BEGIN PROGRESSING INTO THE REGION THURSDAY AFTERNOON. RIGHT NOW THE GUIDANCE ALSO WANTS INDICATE THIS UPPER LEVEL LOW BECOMING QUASI- STATIONARY GENERALLY ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS WOULD KEEP THE REGION IN A ACTIVE PATTERN THROUGH MUCH OF THE LONG TERM PERIOD. THIS QUASI-STATIONARY TROUGH SETUP IS ALSO GENERALLY SUPPORTED BY THE 23/12Z GFS/ECMWF RESPECTIVE ENSEMBLE MEAN. HIGH AND LOW TEMPERATURES FOR THE PERIOD WILL GENERALLY BE NEAR NORMAL. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... NEAR TERM: VRBL CONDS ACROSS THE AREA THIS AM W/ SOME IFR IN FOG ACROSS THE N TO VFR CONDS ACROSS THE S. EXPECT FOG TO DISSIPATE ERLY THIS AM W/ PREDOM VFR CONDS TDY EXPECT OCNL MVFR TO BRIEF IFR PSBL IN ANY SHOWERS/TSTMS. FOG WILL AGAIN BE A THREAT TNGT ALONG W/ A CONTD CHC OF SHOWERS AND PSBL THUNDER... SHORT TERM: MOST SITES LOOK TO STAY VFR THROUGH THE PERIOD WITH THE EXCEPTION OF THOSE SITES THAT RECEIVE SHOWER AND THUNDERSTORM ACTIVITY. THIS WILL BE MORE LIKELY FOR THE NORTHERN SITES. && .MARINE... NEAR TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THRU TONIGHT. VISIBILITIES COULD BE REDUCED IN PATCHY FOG TODAY AND IN MORE WDSPRD AREAS OF FOG TNGT. SHORT TERM: MARINE: NO HEADLINES EXPECTED AT THIS TIME WITH SEAS GENERALLY STAYING 2 TO 4 FT AND WINDS 10 TO 15 KT. VISIBILITIES COULD BE REDUCED WITH SHOWERS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...KHW SHORT TERM...JORDAN LONG TERM...JORDAN AVIATION...KHW/JORDAN MARINE...KHW/JORDAN
AREA FORECAST DISCUSSION
NWS GRAY ME
534 AM EDT MON JUN 24 2013 .SYNOPSIS... WARM AND MOIST AIR CONTINUES TO POOL ALONG AND SOUTH OF A STATIONARY FRONT SITUATED TO OUR NORTH. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH DAY THROUGH THE WEEK AS SEVERAL DISTURBANCES CROSS THE REGION. A LARGE UPPER LEVEL TROUGH WILL APPROACH FROM THE WEST LATE IN THE WEEK. THIS WILL ALLOW FOR COOLER TEMPERATURES...BUT INCREASE THE CHANCE FOR SHOWERS ACROSS THE REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE... UPDATE EARLY THIS MORNING IF FOR THE CHANCES OF PRECIPTATION BEING LIMITED THIS MORNING...WITH THE EXCEPTION OF THE NORTH AND MOUNTAINS WHERE OLD MCS CONTINUES TO DETEORATE AND MOVE EAST ACROSS MAINE. LATEST HRRR MODEL IS PICKING UP ON THIS SYSTEM WELL THIS MORNING. CONVECTIVE INITIATION THIS AFTERNOON APPEARS TO BE AROUND 18Z-19Z OVER VERMONT. CELLS WILL ENTER NEW HAMPSHIRE BY AROUND 20Z. PREV DISC... THE REMAINS OF AN MCS WILL CROSS NORTHERN SECTIONS EARLY THIS MORNING...AS IT CONTINUES TO WEAKEN AS IT MOVES EAST. A DEVELOPING WESTERLY FLOW ALOFT WILL ALLOW 850 MB TEMPERATURES TO CLIMB TO AOA +16C DURING THE AFTERNOON HOURS. WITH AMPLE MIXING...WE SHOULD EXPECT SOME LOWER 90S OVER SOUTHERN/CENTRAL NH AND ADJACENT SECTIONS OF WESTERN MAINE. THERE WILL BE A SURFACE TROUGH SITUATED NEAR AND ALONG THE COASTLINE...SO ONSHORE WINDS WILL LIKELY KEEP THINGS COOLER OVER THE MIDCOAST REGION. CAPES SOAR THIS AFTERNOON INTO THE 1500 J/KG RANGE OVER SOUTHERN MAINE AND POSSIBLY SOUTHERN NEW HAMPSHIRE DURING THE AFTERNOON HOURS TODAY AS A SHORT WAVE APPROACHES FROM THE WEST. LIS DROP SIGNIFICANTLY AS WELL. WE ARE NOT OUTLOOKED BY SPC TODAY...HOWEVER FEEL COMPELLED TO AT LEAST MENTIONED GUSTY WINDS AND SMALL HAIL IN THIS AREA. PRECIPITABLE WATER VALUES WILL BE VERY HIGH TODAY...CLOSE TO 1.75 INCHES. WESTERLY FLOW SHOULD ALLOW FOR QUICK PROGRESSION OF STORMS. NEVERTHELESS...ANY TRAINING ECHOES WILL NEED TO BE MONITORED CLOSELY FOR THE THREAT OF HEAVY RAINFALL. USED A BLEND OF MAV/MET MOS FOR DAYTIME MAX TEMPERATURES...WHICH PLACES MANY AREAS IN THE LOWER 90S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... PATCHY FOG WILL REDEVELOP TONIGHT...ESPECIALLY IN THE VALLEY LOCATIONS. THEREAFTER...SHOWERS AND THUNDERSTORMS WILL DEVELOP DURING THE EARLY AFTERNOON HOURS ON TUESDAY AS VORT MAX APPROACHES FROM THE NORTH. EXPECT SEVERAL STORMS TO PRODUCE DAMAGING WIND GUSTS AS THE PRIMARY THREAT FOR SEVERE WEATHER AS THE WIND MAX CROSSES THE REGION...BUT WE CAN`T RULE OUT THE POSSIBILITY OF LARGE HAIL AS WELL. WILL HIGHLIGHT THIS IN THE HWO. EXPECT MANY COMMUNITIES TO TOP OUT AT OR ABOVE 90 DEGREES ONCE AGAIN OVER SOUTHER/CENTRAL NEW HAMPSHIRE AND WESTERN MAINE. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... THRU THE OUTLOOK PERIOD THE EVOLUTION OF A LONG WAVE TROF WILL BECOME ESTABLISHED OVER THE ERN GT LAKES AND EXTEND S INTO THE OHIO VALLEY. THIS L/WV TROF WILL BECOME THE MAIN WX PRODUCER FOR THE FCST PERIOD OF WED-SUN. THE DEVELOPING EASTERN L/WV TROF WILL MEAN A CONTINUED MOIST AND UNSTBL SSWLY FLOW AT THE SFC/ALOFT THRU THE WEEK. SHWRS/TSTMS ARE EXPECTED THROUGHOUT THE WEEK AND INTO THE WEEKEND. TEMPS WILL BE COOLER THROUGH THE WEEK DUE TO PLENTY OF CLOUDS AND THE MOIST SLY FLOW. HIGH TEMPS WILL BE MOSTLY IN THE 70S BUT DEWPOINTS WILL REMAIN HIGH SO IT WILL BE MUGGY AS WELL. USED A BLEND OF THE MAV/MET GUID FOR 4TH/5TH PERIODS AND THEN THE ADJUSTED MEX TEMPS FOR DAYS 4-7. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... SHORT TERM... MOISTURE TRAPPED UNDER AN INVERSION WILL KEEP PERIODS OF LIFR AND VLIFR CEILINGS IN THE TERMINAL FORECASTS EARLY THIS MORNING. WEST WINDS TODAY MAY GUST INTO THE LOWER 20S. WINDS AND THE POTENTIAL FOR HAIL IS POSSIBLE OVER SOUTHERN AREAS OF MAINE THIS AFTERNOON AND OVER ALL AREAS ON TUESDAY. LONG TERM... VARIABLE CONDS EXPECTED THRU THE OUTLOOK PERIOD. VFR CONDS ARE EXPECTED AT TIMES BUT WILL LOWER TO MVFR TO IFR IN SCT SHWRS/TSTMS THROUGHOUT THE MIDDLE TO END OF THE WEEK. && .MARINE... SHORT TERM... WINDS MAY BECOME GUSTY OVER THE OUTER WATERS TODAY...BUT MOST LIKELY REMAINING BELOW SCA CRITERIA. SIMILAR CONDITIONS WILL FOLLOW ON TUESDAY. LONG TERM... WINDS/SEAS WILL REMAIN BLO SCA CONDS THRU THURSDAY BUT MAY INCREASE TO SCA CRITERIA ON FRI DUE TO AN INCREASING SLY PRES GRADIENT ALLOWING WINDS AND SEAS TO INCREASE. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
407 AM EDT MON JUN 24 2013 .SYNOPSIS... UNSETTLED CONDITIONS WITH SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST THROUGH MID WEEK.&& .NEAR TERM /THROUGH TONIGHT/... DECAYING MCS OVR SRN QUEBEC ATTM ABOUT TO ENTER FAR WRN MAINE... OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ACROSS THE FA ATTM W/ SOME FOG ACROSS THE N. NOT MUCH CHANGE IN THE OVERALL PTRN ACROSS OUR AREA LAST 24 HRS AT LEAST IN THE UPPER LEVELS OF THE ATMOS AS BRISK WNW FLOW ALOFT PERSISTS W/ OCNL DISTURBANCES EMBEDDED IN THIS FLOW. IN THE LOWER LEVELS - A VRY WARM AND HUMID SWRLY FLOW IS NOW IN PLACE ACROSS THE ENTIRE REGION W/ TDS GENERALLY IN THE LOWER TO MID 60S. THE DECAYING MCS IS SHOWN BY THE SHORTER TERM MODELS SUCH AS THE RUC TO CONT TO MV ESEWRD AND HOLD TOGETHER ENUF TO HAVE SOME IMPACT ON OUR WRN ZNS ERLY TDY THEN ACROSS OUR S CENTRAL ZNS THRU THE AM HRS AND POPS ACROSS THESE AREAS WILL REFLECT THIS. OTHERWISE...ANOTHER UPPER DISTURBANCE IS FCST TO SLIDE ESEWRD ACROSS THE FA LATER TDY AND PROVIDE ANOTHER UPTICK IN SHOWERS/TSTMS. UNLIKE SUN...WHERE MOST ACTION WAS S OF THE AREA - APPEARS TDY THAT THINGS HAVE SHIFTED A LITTLE FURTHER N W/ THE INTRUSION OF THE WARMER AND MORE HUMID AIR. AS A RESULT...WILL CARRY MAINLY CHC POPS ACROSS THE REMAINDER OF THE FA TDY INTO THIS EVE W/ ACTIVITY EXPECTED TO AGAIN WEAKEN/DISSIPATE LATER THIS EVE AS THIS UPPER DISTURBANCE MVS AWAY FROM THE REGION. THIS WILL SET THE STAGE FOR MORE PATCHY FOG W/ THE FOG PROBABLY A LITTLE MORE WDSPRD THAN THIS AM W/ THE HUMID AIRMASS PERSISTING. TEMPS TDY WILL BE A LITTLE TRICKY... CLDS AND SHOWERS WILL NO DOUBT HAVE SOME IMPACT AND PROBABLY KEEP MOST AREAS FROM REACHING FULL POTENTIAL TDY. STILL...A LITTLE SUNSHINE FROM TIME TO TIME IS EXPECTED AND WILL GO A LONG WAY IN HEATING THINGS UP SO WILL HANG ONTO HIGHS INTO THE LOWER 80S N W/ MID TO PSBLY UPPER 80S CENTRAL AND INTERIOR DOWNEAST...&& .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... PERIOD WILL BEGIN WITH A SURFACE HIGH SETUP IN THE ATLANTIC AND BOUNDARY DRAPED JUST TO THE NORTH OF THE REGION. THE SURFACE HIGH WILL CONTINUE TO PUMP WARM AND MOIST AIR INTO THE REGION. GUIDANCE IS IN FAIR AGREEMENT WITH THE BOUNDARY AND SURFACE LOW BEGINNING TO DROP SOUTH THROUGH THE DAY ON TUESDAY. THIS COMBINED WITH BETTER UPPER LEVEL DYNAMICS WITH THE REGION LOCATED IN THE FAVORABLE RIGHT ENTRANCE REGION OF UPPER LEVEL JET ENHANCING DIVERGENCE ALOFT. ALSO WITH WARM AND MOIST UNSTABLE AIR IN PLACE CAPE VALUES WILL BE GENERALLY BETWEEN 500 TO 1500 J/KG. THESE DYNAMICS WILL MAKE IT POSSIBLE TO HAVE SOME MORE ENHANCED THUNDERSTORM ACTIVITY TUESDAY AFTERNOON AND EVENING. RIGHT NOW THINKING IS THERE WILL BE THE POTENTIAL FOR SMALL HAIL AND GUSTY WINDS BUT THIS MAY NEED TO BE ENHANCED FURTHER IF DYNAMICS CONTINUE TO COME TOGETHER. BEST CHANCES STILL LOOK TO BE ACROSS THE NORTHERN AND CENTRAL PORTIONS OF THE REGION WHERE BEST SUPPORTING DYNAMICS ARE PRESENT. THERE IS SOME MODEL DIVERGENCE FOR WEDNESDAY WITH THE MOST OF GUIDANCE WANTING TO KEEP THE LOW PRESSURE ACROSS THE REGION WHILE THE 23/12Z ECMWF WANTS TO KEEP IT DRIER. RIGHT NOW WILL KEEP DECENT CONSISTENCY WITH PREVIOUS FORECAST WITH MORE SHOWERY TYPE ACTIVITY. TEMPERATURES FOR WEDNESDAY LOOK TO BE COOLER ALTHOUGH THIS WILL BE HIGHLY DEPENDENT ON CLOUD COVER. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE GUIDANCE IS STILL A BIT DIVERGENT IN THE BEGINNING OF THE LONG TERM PERIOD. THE 24/00Z GFS/GEM WANTS TO HOLD ON TO THE BOUNDARY AND SURFACE LOW A BIT LONGER THAN THE 23/12Z ECMWF FOR WEDNESDAY NIGHT. THEN WE WILL SEE ANOTHER STRONG UPPER LEVEL DISTURBANCE ACROSS THE GREAT LAKES CONTINUE TO PROGRESS EAST. ALL THE LONG RANGE GUIDANCE INDICATES THIS MOVING EAST BUT WITH SLIGHT DIFFERENCES IN TIMING. GENERALLY IT LOOKS LIKE THIS SYSTEM WILL BEGIN PROGRESSING INTO THE REGION THURSDAY AFTERNOON. RIGHT NOW THE GUIDANCE ALSO WANTS INDICATE THIS UPPER LEVEL LOW BECOMING QUASI- STATIONARY GENERALLY ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS WOULD KEEP THE REGION IN A ACTIVE PATTERN THROUGH MUCH OF THE LONG TERM PERIOD. THIS QUASI-STATIONARY TROUGH SETUP IS ALSO GENERALLY SUPPORTED BY THE 23/12Z GFS/ECMWF RESPECTIVE ENSEMBLE MEAN. HIGH AND LOW TEMPERATURES FOR THE PERIOD WILL GENERALLY BE NEAR NORMAL. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... NEAR TERM: VRBL CONDS ACROSS THE AREA THIS AM W/ SOME IFR IN FOG ACROSS THE N TO VFR CONDS ACROSS THE S. EXPECT FOG TO DISSIPATE ERLY THIS AM W/ PREDOM VFR CONDS TDY EXPECT OCNL MVFR TO BRIEF IFR PSBL IN ANY SHOWERS/TSTMS. FOG WILL AGAIN BE A THREAT TNGT ALONG W/ A CONTD CHC OF SHOWERS AND PSBL THUNDER... SHORT TERM: MOST SITES LOOK TO STAY VFR THROUGH THE PERIOD WITH THE EXCEPTION OF THOSE SITES THAT RECEIVE SHOWER AND THUNDERSTORM ACTIVITY. THIS WILL BE MORE LIKELY FOR THE NORTHERN SITES. && .MARINE... NEAR TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THRU TONIGHT. VISIBILITIES COULD BE REDUCED IN PATCHY FOG TODAY AND IN MORE WDSPRD AREAS OF FOG TNGT. SHORT TERM: MARINE: NO HEADLINES EXPECTED AT THIS TIME WITH SEAS GENERALLY STAYING 2 TO 4 FT AND WINDS 10 TO 15 KT. VISIBILITIES COULD BE REDUCED WITH SHOWERS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...KHW SHORT TERM...JORDAN LONG TERM...JORDAN AVIATION...KHW/JORDAN MARINE...KHW/JORDAN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
120 AM EDT MON JUN 24 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 418 PM EDT SUN JUN 23 2013 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER SE SASK INTO SRN MANITOBA WITH A SHORTWAVE TROUGH EXTENDING INTO ERN ND AND NW MN. AT THE SFC...A 999MB SFC LOW WAS LOCATED OVER THE NW CORNER OF MN WITH A WARM FRONT EXTENDING INTO SRN LAKE SUPERIOR. CLEARING AND AFTERNOON HEATING HAS PUSHED TEMPS INTO THE LOWER 80S OVER WRN UPPER MI RESULTING IN MLCAPE VALUES TO AROUND 1500 J/KG. SCT SHRA/TSRA WERE DEVELOPING OVER WRN LAKE SUPERIOR INTO NW UPPER MI CLOSEST TO THE FORCING ASSOCIATED WITH THE ND/MN SHRTWV. EXPECT THAT SCT SHRA/SHRA WILL CONTINUE TO DEVELOP BACK THROUGH WRN UPPER MI LATE THIS AFTERNOON AS A WEAK TROUGH MOVES INTO THE AREA...PER HIGH RES MODELS. INSTABILITY ALONG WITH 30-35 KT 0-6KM SHEAR AND 20-25 KT 0-1KM SHEAR COULD SUPPORT AT LEAST ISOLD STRONG/SEVERE STORMS...WITH STRONG WIND GUSTS AS THE MAIN HAZARD GIVEN DCAPE VALUES INTO THE 500-1000 J/KG RANGE. EXPECT THAT THE SHRA/TSRA WILL SPREAD INTO CNTRL UPPER MI BY 21Z-23Z AND THEN DISSIPATE AND WEAKEN BY LATE EVENING AS THE SHRA/TSRA MOVE TOWARD THE ERN CWA...AWAY FROM THE THE STRONGER INSTABILITY AND THE SHRTWV FORCING. AS THE SHORTWAVE AND LOW MOVE INTO NRN ONTARIO THE DRY SLOT AND STRONG MID LEVEL DRYING WILL SPREAD ACROSS THE REGION LATE TONIGHT INTO MONDAY. THIS WILL HELP MINIMIZE CHANCES FOR ADDITIONAL CONVECTION. WITH SUNSHINE AND 850 MB TEMPS STILL AROUND 15C...TEMPS WILL AGAIN CLIMB INTO THE LOWER 80S. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 418 PM EDT SUN JUN 23 2013 GENERAL AGREEMENT IN OVERALL LOOK OF LARGER SCALE PATTERN INTO NEXT WEEKEND THOUGH DETAILS AND SPECIFICS REMAIN UNCERTAIN. TO START ON MONDAY EVENING...FAIRLY STRONG SHORTWAVE TROUGH WILL BE HEADING EAST ACROSS NORTHERN ONTARIO LEAVING RIDGING IN ITS WAKE OVER NORTHERN PLAINS. SFC FRONT AND POOL OF SFC-H85 MOISTURE ALONG THE BOUNDARY DRIVES SOUTH OF CWA BY LATE MONDAY EVENING RESULTING IN GENERALLY QUIET AND LESS HUMID WEATHER INTO MUCH OF TUESDAY. GFS AND ECMWF AGREE HERE...WHILE THE GEM-NH AND THE UKMET DO NOT PUSH WARM FRONT FAR ENOUGH SOUTH TO KEEP CHANCES OF SHRA/TSRA OUT OF CWA. WILL LEAN ON THE MORE CONSISTENT ECMWF IDEA WHICH IS SUPPORTED BY WPC HAND DRAWN SFC MAP. WITH WARM FRONT AND EDGE OF SFC BASED-MUCAPE MOST LIKELY STILL SOUTH BY TUESDAY AFTN...WONDER IF MOST AREAS STAY DRY THROUGH TUESDAY. ANY SHRA/TSRA THAT FORM MONDAY NIGHT INTO TUESDAY MORNING SHOULD STAY SOUTH OF CWA PER H85-H3 THICKNESSES AND FORWARD PROPAGATING CORFIDI VECTORS AND EVEN THE MEAN LAYER WIND. INTO TUESDAY NIGHT...ECMWF AND GFS STILL HAVE SHORTWAVE CRASHING THROUGH TOP EDGE OF LARGER SCALE RIDGING. WAVE MAY AID IN BRINGING AT LEAST H85 FRONT FAR ENOUGH NORTH THAT SOUTHERN TIER COULD BE AFFECTED BY SHRA/TSRA TUESDAY NIGHT AND MUCH OF THE CWA COULD SEE SHRA/TSRA ON WEDNESDAY. GFS STRONGER WITH THIS WAVE SO MUCH THAT IT PUSHES SFC WARM FRONT INTO CWA ON WEDNESDAY. PV ANAMOLY THAT GFS CARRIES IN HERE ON WEDNESDAY TRACKS BACK TO SOUTH EDGE OF STRONG UPR LOW OVER THE ALLUTIANS THIS MORNING. WAVE LOOKS PRETTY VIGOROUS ON WV LOOP. ECMWF HAS BETTER TRACK RECORD IN THE EXTENDED...BUT WILL BLEND SOME OF THE GFS IDEA IN AS WELL SINCE IT SEEMS TO HAVE SOME MERIT. TROUGH AND HIGHER SFC-H85 DWPNTS PUSH THROUGH AREA WEDNESDAY EVENING AND COOLER AIR ARRIVES LATER ON THURSDAY. GFS QUICKER AND STRONGER AS WELL AS FARTHER SOUTH WITH SHORTWAVE TROUGH DIGGING ACROSS UPR LAKES ON THURSDAY WHILE THE ECMWF SHOWS MORE SEPARATION BTWN THE WAVE ON WEDNESDAY AND THAT STRONGER TROUGHING. GFS HAS TENDENCY TO BRING SYSTEMS IN TOO QUICKLY AND ITS SOLUTION VERIFYING AT 12Z THURSDAY HAS SHOWN TOO MUCH INCONSISTENCY TO PUT MUCH STOCK IN IT AT THIS POINT. ECMWF HAS TRENDED A BIT SHAPRER WITH TROUGH BUT OVERALL HAS BEEN MUCH MORE CONSISTENT THAN GFS. WILL PREFER THAT IDEA FOR NOW. RESULT WILL BE SCT SHRA/TSRA...MAYBE EVEN NMRS FOR A TIME WEDNESDAY OR WEDNESDAY EVENING...THEN DIMINISHING WITH LOSS OF INSTABILITY AXIS LATER WEDNESDAY NIGHT. POTENTIAL FOR ANOTHER ROUND OF SCT SHRA/TSRA DURING PEAK HEATING ON THURSDAY AS AIRMASS OVER THE REGION IS STILL A BIT UNSTABLE /MLCAPES UP TO 1000 J/KG/ WHILE WNW FLOW ALOFT INCREASES ON SOUTH EDGE OF UPPER TROUGH. LIGHT AND VARIABLE SFC WINDS COULD RESULT IN LAKE BREEZE CONVERGENCE AS WELL. ALWAYS HAVE TO WATCH OUT FOR WNW-NW FLOW ALOFT AS THAT PATTERN WITH SUFFICIENT INSTABILITY IS ONE THAT CAN RESULT IN AT LEAST SOME CHANCE OF SEVERE WEATHER. UPPER TROUGH DOMINATES ON FRIDAY WITH A BIT COOLER AND UNSETTLED WEATHER. NO TSRA EXPECTED ON FRIDAY AS COOLER TEMPS ALOFT/STEEPER LAPSE RATES SETUP FROM NORTHERN ONTARIO INTO THE LOWER GREAT LAKES. COULD BE SHRA AT TIMES THOUGH AS SMALLER SCALE SHORTWAVES ROTATE AROUND PRIMARY UPPER TROUGH. FRIDAY NIGHT INTO SATURDAY MAY BE KIND OF BLUSTERY ALONG LK SUPERIOR AND WITH ONSHORE WINDS SWIM RISK MAY BE HIGHER TO START THE WEEKEND. SMALL CHANCES OF SHRA MAY LINGER INTO SATURDAY AS WELL. TEMPS SOME AREAS FRIDAY INTO SATURDAY MAY END UP MORE THAN 10 DEGREES BELOW NORMAL. HIGH PRESSURE BUILDS IN FOR LATER IN THE WEEKEND...RESULTING IN TEMPS BOUNCING UP AT LEAST TOWARD NORMAL. NEXT SHORTWAVE IN WNW FLOW APPEARS LATE IN THE WEEKEND SO HAVE POPS MOVING BACK IN FOR LATE SUNDAY. NO REAL WARM TEMPERATURES SEEN NEXT WEEKEND OR EVEN INTO EARLY NEXT WEEK AS TROUGHING ALOFT OVER EASTERN CANADA AND GREAT LAKES KEEPS WARM AIR RESTRICTED TO WESTERN AND SOUTHERN PORTIONS OF CONUS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 120 AM EDT MON JUN 24 2013 WITH HUMID AIR MASS IN PLACE AND SOME RAINFALL ACROSS THE AREA YESTERDAY...MAY SEE SOME FOG OVERNIGHT...REDUCING VIS TO MVFR. GIVEN STRONGER WINDS JUST ABOVE NOCTURNAL INVERSION THAT WILL INDUCE SUFFICIENT MECHANICAL MIXING...FOG SHOULDN`T BECOME TOO THICK TO REDUCE VIS BLO MVFR. OTHERWISE...VFR CONDITIONS SHOULD PREVAIL THRU THE PERIOD AT KIWD/KCMX/KSAW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 418 PM EDT SUN JUN 23 2013 WINDS SHOULD REMAIN 25 KTS OR LESS THROUGH THE UPCOMING WEEK. MAIN HAZARD WILL BE SCT THUNDERSTORMS TONIGHT AND FOG. DENSE FOG ADVISORIES HAVE BEEN EXTENDED THROUGH TONIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... DENSE FOG ADVISORY UNTIL 5 AM EDT /4 AM CDT/ EARLY THIS MORNING FOR LSZ162-263>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...ROLFSON MARINE...JLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
ISSUED BY THE NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 115 AM CDT MON JUN 24 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 317 PM CDT SUN JUN 23 2013 MORNING MAP ANALYSIS INDICATES QUASI ZONAL TO SOUTHWESTERLY MID TO UPPER LEVEL FLOW OVER THE WESTERN HALF OF THE CONUS...WITH A LONGWAVE RIDGE OVER THE EAST. A COUPLE OF MID LEVEL SHORT WAVES ARE ALSO NOTED...WITH ONE EXTENDING FROM THE UPPER MISSISSIPPI VALLEY INTO THE NORTHERN PLAINS...AND THE OTHER OVER THE SOUTHWESTERN CONUS. MID TO UPPER LEVEL JET ENERGY EXTENDS FROM THE WEST/SOUTHWESTERN CONUS...EAST/NORTHEAST INTO THE CENTRAL PLAINS...AND THEN NORTH INTO SOUTH CENTRAL CANADA BEFORE FLOWING EAST INTO SOUTHEASTERN CANADA AND PORTIONS OF THE NORTHEASTERN CONUS. MID TO UPPER LEVEL FLOW OVER OUR AREA MAXES OUT AT AROUND 60KTS BETWEEN 300MB AND 200MB PER 12Z SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR IMAGERY ALSO SHOWS THE AFOREMENTIONED MID LEVEL SHORT WAVES...ALONG WITH A PAIR OF CLOSED MID LEVEL LOWS. ONE SUCH LOW IS LOCATED OVER EASTERN ALBERTA AND WESTERN SASKATCHEWAN...AND THE OTHER IS OVER THE PACIFIC JUST OFF THE COAST OF THE NORTHWESTERN CONUS. AT THE SURFACE AN AREA OF LOW BAROMETRIC PRESSURE EXISTS OVER SOUTHWESTERN KANSAS...WITH A FRONTAL BOUNDARY EXTENDING NORTHEAST FROM THE LOW INTO NORTH CENTRAL KANSAS AND SOUTHEASTERN NEBRASKA. THE LOW LEVEL WIND FIELD ACROSS MUCH OF OUR CWA REMAINS FROM THE NORTHEAST FOR THE MOST PART...BUT LOCATIONS ACROSS OUR SOUTHEAST SUCH AS KK82...KK61...AND KHJH ARE ALL OBSERVING A SURFACE WIND FROM THE SOUTHEAST. GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN SUGGESTS THE LOW LEVEL BAROCLINIC ZONE WILL PERSIST OVER SOUTHEASTERN PORTIONS OF OUR CWA THIS EVENING INTO TONIGHT BEFORE SURGING NORTH DURING THE DAY MONDAY. THERE ARE INDICATIONS...ESPECIALLY FROM HIGHER RESOLUTION MODELS SUCH AS THE NAM12...OF VERY SUBTLE MID LEVEL PERTURBATIONS MOVING OVERHEAD WITHIN THE MEAN FLOW THIS AFTERNOON AND THIS EVENING. CONFIDENCE ON SUCH A FEATURE PROMOTING PRECIPITATION PRODUCTION ACROSS OUR AREA THIS AFTERNOON AND EVENING REMAINS VERY LOW HOWEVER AND AS A RESULT...WILL CONTINUE RELEGATING ANY AFTERNOON AND EVENING POPS TO OUR SOUTH/SOUTHEASTERN CWA...IN CLOSEST PROXIMITY TO THE AFOREMENTIONED LOW LEVEL BAROCLINIC ZONE AND RESULTANT AXIS OF ENHANCED LOW LEVEL CONVERGENCE AND LIFT. AS FOR THE TIMING OF CONVECTIVE INITIATION THIS AFTERNOON AND EVENING...FORECAST PROXIMITY SOUNDINGS FROM THE NAM...OPERATIONAL GFS...AND RAP ALL SUGGEST A HEALTHY CAP PERSISTING THROUGH AT LEAST 00Z. GIVEN THIS...ITS HARD TO BUY INTO QPF FIELDS FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN...WHICH ALL SUGGEST WIDESPREAD PRECIPITATION WILL BE REALIZED ACROSS PORTIONS OF OUR SOUTHEAST BEFORE 00Z THIS EVENING. HRRR SIMULATED REFLECTIVITY LOOKS MUCH MORE REASONABLE...SUGGESTING VERY ISOLATED CONVECTION OCCURRING ACROSS OUR SOUTHEAST TOWARDS 00Z. GIVEN ALL THIS...CONFIDENCE IS VERY LOW THAT MUCH PRECIPITATION WILL BE REALIZED ACROSS OUR AREA PRIOR TO 00Z...BUT CANNOT COMPLETELY RULE OUT SUCH A SOLUTION AND WILL MAINTAIN ~20% POPS ACROSS OUR SOUTHEAST 23-00Z. 00Z AND BEYOND...FORECAST PROXIMITY SOUNDINGS SUGGEST THE CAPPING INVERSION WILL WEAKEN SOMEWHAT THUS MAKING CONVECTION SOMEWHAT MORE LIKELY...A SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN...AS WELL AS SIMULATED REFLECTIVITY FROM THE HRRR. GIVEN THIS...WILL GO AHEAD WITH SLIGHTLY HIGHER POPS...~%30...00-06Z ACROSS OUR SOUTHEAST. SHOULD SURFACE-BASED CONVECTION BE REALIZED THIS AFTERNOON AND/OR EVENING...THEN SEVERE WEATHER WILL LIKELY RESULT WITH DEEP LAYER MUCAPE VALUES IN THE 2000-4000J/KG WAITING FOR UPDRAFT PRODUCTION AND 30-35KTS OF DEEP LAYER BULK SHEAR FOR UPDRAFT ENHANCEMENT. CERTAINLY LARGE HAIL AND MICROBURST-RELATED WIND GUSTS WILL BE A THREAT...BUT ENHANCED HORIZONTAL VORTICITY IN THE VICINITY OF THE LOW LEVEL BAROCLINIC ZONE COULD ALSO PROMOTE ISOLATED TORNADIC ACTIVITY. WILL CONTINUE SUCH WORDING IN THE HWO AS A RESULT. HEADING INTO THE OVERNIGHT HOURS TONIGHT...THE AXIS OF A ~45KT 850MB JET STREAK IS EXPECTED TO DEVELOP ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS...WITH THE NOSE OF THIS LOW LEVEL JET MOVING INTO SOUTHERN PORTIONS OF OUR CWA BETWEEN 06Z AND 12Z. SHOULD DEEP CONVECTION BE ONGOING ALONG THE LOW LEVEL BAROCLINIC ZONE...THEN INCREASING LOW LEVEL THERMAL ADVECTION ALONG THE AXIS OF THE LOW LEVEL JET COULD CERTAINLY HELP INCREASE SPATIAL COVERAGE OF SAID CONVECTIVE ACTIVITY. ALSO...IN ADDITION TO POSSIBLE THUNDERSTORM ACTIVITY OVER PORTIONS OF OUR CWA THIS AFTERNOON AND EVENING...THUNDERSTORMS ALSO REMAIN POSSIBLE OVER THE CENTRAL HIGH PLAINS. SHOULD HIGH PLAINS CONVECTION DEVELOP THIS AFTERNOON/EVENING AND MOVE EAST TOWARDS OUR AREA TONIGHT...ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY COULD BE REALIZED OVER OUR AREA TONIGHT...ESPECIALLY OUR WEST. THIS IS A SOLUTION SUPPORTED BY THE NAM...OPERATIONAL GFS...SREF-MEAN...AND HRRR. GIVEN ALL THIS...WENT AHEAD WITH RELATIVELY HIGHER POPS ACROSS MUCH OF THE CWA STARTING AROUND 06Z. SEVERE WEATHER COULD CERTAINLY BE POSSIBLE DURING THE EARLY PART OF THE OVERNIGHT HOURS AS THE MORE ROBUST CONVECTION FROM EARLIER IN THE EVENING...SHOULD IT DEVELOP...MAINTAINS ITSELF. THAT BEING SAID...BARRING THE DEVELOPMENT OF AN MCS ACROSS THE REGION...CONVECTIVE ACTIVITY SHOULD WANE IN INTENSITY AS POTENTIAL INSTABILITY DECREASES 06Z ONWARD. THERE COULD SOME LINGERING SHOWER AND THUNDERSTORM ACTIVITY ACROSS OUR AREA AROUND SUNRISE MONDAY...BUT OTHERWISE MONDAY DURING THE DAY IS EXPECTED TO REMAIN DRY FOR THE MOST PART AS THE WARM FRONT SURGES NORTH AND AN OVERALL LACK IN KINEMATIC FORCING OVERTAKES THE AREA. AT THIS TIME THE ONLY REAL THREAT FOR PRECIPITATION DURING THE DAY MONDAY APPEARS AS THOUGH IT WILL RESIDE OVER OUR SOUTHWESTERN CWA DURING THE LATE AFTERNOON AND EVENING HOURS...WHICH IS WHERE AND WHEN GUIDANCE SUGGESTS AN ADVANCING LOW LEVEL DRY LINE WILL BULGE EAST. AN AREA OF LOCALLY ENHANCED CONVERGENCE AND LIFT IN THE VICINITY OF THIS DRY LINE BULGE...WORKING IN CONCERT WITH DIABATIC HEATING...MAY BE ENOUGH TO INITIALIZE ISOLATED SHOWER AND THUNDERSTORM DEVELOPMENT AND AS A RESULT...~20% POPS ARE FORECAST 21Z MONDAY THROUGH 00Z TUESDAY ACROSS OUR SOUTHWEST. SHOULD THUNDERSTORM ACTIVITY BE REALIZED LATE MONDAY AFTERNOON AND/OR EVENING...THEN DEEP LAYER MUCAPE VALUES OF 2000-3000J/KG...ALONG WITH DEEP LAYER BULK SHEAR VALUES OF ~30KTS...WILL BE AVAILABLE FOR UPDRAFT PRODUCTION AND ENHANCEMENT. GIVEN THIS...WILL GO AHEAD AND HIGHLIGHT THE THREAT FOR ISOLATED SEVERE WEATHER ACROSS OUR SOUTHWEST MONDAY AFTERNOON AND EVENING. FINALLY...INCREASING SOUTHERLY FLOW WILL LIKELY BE OBSERVED MONDAY AFTERNOON ONCE THE SURFACE WARM FRONT SURGES NORTH. GUIDANCE SUGGESTS A SUSTAINED WIND OF ~24KTS...WITH HIGHER GUSTS APPROACHING 35KTS...WILL BE REALIZED PRIMARILY ACROSS NORTH CENTRAL KANSAS. AS A RESULT...WILL CONTINUE MENTIONING SUCH CONDITIONS IN THE HWO. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 317 PM CDT SUN JUN 23 2013 MONDAY NIGHT...A VORT MAX LOCATED OVER THE HIGH PLAINS WILL TRACK EAST ACROSS THE FORECAST AREA. THUNDERSTORMS THAT INITIALLY FORM ACROSS THE HIGH PLAINS DURING THE MONDAY AFTERNOON HOURS WILL SLIDE EAST DURING THE EVENING AND OVERNIGHT HOURS...AND IF THEY HOLD TOGETHER MAY BRING RAIN TO PORTIONS OF THE FORECAST AREA. IN ADDITION TO RAIN...SOME OF THESE THUNDERSTORMS MAY BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS POSSIBLE DURING THE EVENING HOURS. INSTABILITY IS HIGH AND DEEP LAYER SHEAR IS MORE MODEST BUT SUFFICIENT FOR SEVERE STORMS. THE LIMITING FACTOR WILL BE THE WARM MID LEVEL CAP AND THUS CONFIDENCE IN THUNDERSTORM DEVELOPMENT AND COVERAGE IS STILL FAIRLY LOW WITH SLIGHT POPS. THE 12Z ECMWF AND 12Z NAM FAVOR OUR WEST AND NORTH FOR STORMS...WHILE THE 12Z GFS HIGHLIGHTS OUR SOUTHEASTERN ZONES. THE ECMWF AND NAM MAKE MORE SENSE WITH FAVORING NORTH AND WEST ZONES BASED ON THE EXPECTED UPPER WAVE LOCATION AND THE INCREASING STRENGTH OF THE CAP AS YOU HEAD SOUTH. TUESDAY AND WEDNESDAY...THE PATTERN WILL BE FAIRLY ZONAL WITH ALL OF THE BETTER UPPER FLOW AND SHORT WAVES TRACKING ACROSS THE NORTHERN TIER STATES. AN UPPER RIDGE WILL SLOWLY BEGIN TO BUILD ACROSS THE SOUTHWEST CONUS STARTING ON WEDNESDAY. A SFC TROUGH AXIS WILL TRACK EAST THROUGH OUR FORECAST AREA LATE ON TUESDAY AND TURN THE WINDS TO NORTHERLY BY WEDNESDAY. HOWEVER...A STRONG CAP SHOULD RESULT IN DRY CONDITIONS FOR MOST AREAS AND WILL CONTINUE TO CALL FOR A DRY FORECAST...BUT CAN NOT COMPLETELY RULE OUT AN ISOLATED THUNDERSTORM...HENCE THE 10 PERCENT POPS. TUESDAY WILL BE SCORCHER WITH HIGHS WELL INTO THE 90S ACROSS NEBRASKA TO OVER 100 ACROSS MUCH OF NORTHERN KANSAS. TEMPERATURES WILL FALL A FEW DEGREES WITH THE NORTH WINDS ON WEDNESDAY...BUT CONTINUE TO EXPECT 90S FOR HIGHS. THURSDAY THROUGH SUNDAY...THERE IS A SHIFT IN THE UPPER PATTERN AS AN UPPER RIDGE STRENGTHENS ACROSS THE ROCKIES AND AN UPPER TROUGH PERSISTS ACROSS THE EASTERN CONUS. THIS WILL RESULT IN NORTHWESTERLY FLOW ALOFT FOR OUR FORECAST AREA. MOST AREAS WILL BE DRY THROUGHOUT THIS PERIOD GIVEN A LACK OF FORCING. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS ON THURSDAY INTO THURSDAY NIGHT...BUT MOST RESENT MODEL RUNS ARE STARTING TO BACK OFF OF THIS ALREADY RATHER SLIGHT CHANCE OF PRECIPITATION. ANOTHER WEAK COOL FRONT WILL TRY TO WORK ITS WAY THROUGH AT SOME POINT THURSDAY NIGHT OR FRIDAY...BUT THURSDAY SHOULD STILL BE A HOT DAY WITH 90S ACROSS NEBRASKA TO NEAR 100 IN KANSAS. THE COOLER WEATHER WILL SETTLE IN ON FRIDAY AND SATURDAY WITH EASTERLY TO NORTHEASTERLY SFC WINDS. THIS COOLER FETCH SHOULD DROP HIGHS BACK INTO THE LOWER AND MID 90S ON FRIDAY...AND THEN 80S ACROSS NEBRASKA TO LOWER 90S OVER KANSAS ON SATURDAY. TEMPERATURES BEGIN TO WARM BACK UP ON SUNDAY WITH EVERYONE BACK IN THE 90S. OVERALL...TEMPERATURES WILL NOT VARY THAT MUCH AND REMAIN RATHER TOASTY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 115 AM CDT MON JUN 24 2013 GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. CONVECTION DEVELOPING OFF THE HIGHS PLAINS EARLY TONIGHT WILL SHIFT NEWD AND MAY IMPACT THE GRI TERMINAL AROUND 9-11Z AND WILL INCLUDE A TEMPO GROUP FOR THIS. OTHERWISE SOME MVFR CIGS ARE AROUND THE REGION...BUT WE EXPECT MUCH OF THIS TO LIFT NWD OVERNIGHT BUT SOME MVFR CIGS/VISBY ARE POSSIBLE IN THE TSRA. OTHERWISE SOUTHERLY WINDS WILL INCREASE THROUGH THE DAY ON MON. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM... LONG TERM... AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
105 AM CDT MON JUN 24 2013 .UPDATE... ISSUED AT 105 AM CDT MON JUN 24 2013 NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE AS THE INHERITED FORECAST IS WELL ON TRACK. LEFT FOG OUT OF THE FORECAST FOR NOW...HOWEVER...WILL CONTINUE TO MONITOR THROUGH THE NIGHT WITH LOW TEMPERATURE-DEW POINT SPREADS ESPECIALLY ACROSS THE NORTH WITH LIGHT WINDS AND CLEAR SKIES. DID REMOVE THE MENTION OF A SLIGHT CHANCE OF THUNDERSTORMS ACROSS THE FAR SOUTHWEST LATE TONIGHT WITH LARGE SCALE SUBSIDENCE AND ONLY WEAK LOW LEVEL WARM AIR ADVECTION. IN REGARDS TO THE SEVERE THREAT ON MONDAY...SPC IN THEIR DAY ONE OUTLOOK HAS PLACED THE ENTIRE CWA UNDER A SLIGHT RISK. SEE THE SPC DAY 1 OUTLOOK FOR DETAILS. UPDATE ISSUED AT 952 PM CDT SUN JUN 23 2013 WANING CONVECTION OVER NORTHERN FOSTER COUNTY SHOULD QUICKLY DIMINISH IN THE NEXT HOUR. WILL KEEP A CHANCE POP HERE FOR THE NEXT HOUR. OTHERWISE...ISOLATED SHOWERS FROM SOUTHERN SASKATCHEWAN INTO NORTHWEST NORTH DAKOTA CONTINUE TO QUICKLY DIMINISH. WILL NOT MENTION POPS HERE TONIGHT. OTHERWISE...CURRENT FORECAST IS IN GOOD SHAPE. DID ADJUST CLOUD COVER LOWER FOR MOST AREAS THIS EVENING AND WAS A LITTLE SLOWER TO INCREASE CLOUD COVER AFTER MIDNIGHT IN THE WEST. LATEST 01Z HRRR IS BRINGING SOME LIGHT QPF INTO THE FAR SOUTHWEST BETWEEN 11Z-12Z MONDAY...SO WILL KEEP A SLIGHT CHANCE OF CONVECTION IN THE FAR SOUTHWEST TOWARD MORNING. UPDATE ISSUED AT 703 PM CDT SUN JUN 23 2013 MAIN ISSUE WITH THE EARLY EVENING UPDATE IS CURRENT SHOWER AND THUNDERSTORM ACTIVITY. CURRENTLY SHOWER AND THUNDERSTORMS WERE LOCATED FROM JUST NORTH OF GARRISON...TO MINOT...AND THEN NORTHEAST TO ROLETTE COUNTY. WITH A FEW STRAY SHOWERS EXTENDING BACK TO NEAR CROSBY. ACTIVITY HAS SHOWN A DECREASE IN INTENSITY IN THE PAST TWO HOURS. HAVE ADJUSTED POPS A BIT LOWER AND DECREASED AREAL COVERAGE. EXPECT ACTIVITY TO CONTINUE TO DECREASE OVER THE NEXT FEW HOURS...AND DISSIPATE COMPLETELY BY AROUND 10 PM. OTHERWISE NO SIGNIFICANT CHANGES TO THE CURRENT FORECAST. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 345 PM CDT SUN JUN 23 2013 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE SCATTERED STRONG THUNDERSTORMS NORTH THIS AFTERNOON/EARLY EVENING...FOLLOWED BY ANOTHER CHANCE OF POSSIBLY STRONG TO SEVERE STORMS MONDAY AFTERNOON. CURRENTLY...UPPER LOW OVER CENTRAL SASKATCHEWAN WITH A STRONG EMBEDDED IMPULSE ROTATING NORTHEAST THROUGH THE DEVILS LAKE BASIN INTO NORTHEAST NORTH DAKOTA. STEEP LAPSE RATES WITH COLD AIR ALOFT HAS TRIGGERED A FEW STRONGER STORMS NEAR THE INTERNATIONAL BORDER. A FEW STRONGER STORMS ARE POSSIBLE AND PERHAPS PULSE SEVERE WITH MUCAPE 1-2K J/KG. LACK OF SUPPORTIVE 0-6KM SHEAR WILL LIMIT UPDRAFT LONGEVITY. STORMS ARE DIURNAL IN NATURE AND SHOULD QUICKLY DISSIPATE INTO EARLY THIS EVENING AS THE NOCTURNAL INVERSION DEVELOPS. BEFORE THIS HAPPENS...WILL NEED TO MONITOR FOR POSSIBLE FUNNELS/LAND SPOUTS WITH THE NON-SUPERCELL TOR PARAMETER ELEVATED OVER NORTHWEST NORTH DAKOTA. MOSTLY CLEAR THE REMAINDER OF THIS EVENING IN THE WAKE OF THE CURRENT CONVECTION. MODELS DEVELOP A LOW LEVEL JET LATER THIS EVENING INTO THE OVERNIGHT ACROSS WESTERN SOUTH DAKOTA NOSING INTO SOUTHWEST NORTH DAKOTA LATE AROUND OR AFTER 09Z. WILL INTRODUCE SLIGHT CHANCES FOR THUNDER FAR SOUTHWEST 9-12Z GIVEN THIS FORCING ALONG WITH INCREASING BOUNDARY LAYER MOISTURE. KEPT SLIGHT CHANCE POPS GOING THROUGH THE MORNING HOURS WEST. BOUNDARY LAYER MOISTURE CONTINUES TO ADVECT INTO THE REGION THROUGHOUT THE DAY MONDAY THANKS TO STRONG MID LEVEL FLOW/MOISTURE FETCH FROM THE SOUTHERN PLAINS INTO THE DAKOTAS WITH SFC DEWPOINT TEMPS RISING INTO THE 60S AREA WIDE. THIS WILL CONTRIBUTE TO INCREASING INSTABILITY WITH MUCAPES PROJECTED TO INCREASING TO AROUND 2500 J/KG IN THE AFTERNOON AS SFC TEMPS WARM INTO THE LOW/MID 80S. WHILE A CAPPING INVERSION LOOKS TO BE IN PLACE...A POTENTIAL TRIGGER VIA A LEAD SHORT WAVE IMPULSE IS FORECAST TO APPROACH THE DAKOTAS MONDAY AFTERNOON LEADING TO CONVECTIVE INITIALIZATION. WILL MAINTAIN POPS AS IS FOR NOW DUE TO THE UNCERTAINTY DURING THE AFTERNOON WHERE AND IF STORMS WILL DEVELOP. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 345 PM CDT SUN JUN 23 2013 POTENTIAL FOR SEVERE THUNDERSTORMS CONTINUE MONDAY NIGHT AND TUESDAY. SOUTHWEST FLOW ALOFT TRANSITIONS TO A WESTERLY FLOW WEDNESDAY...THEN NORTHWEST AS RIDGING DEVELOPS OVER THE FOUR CORNERS. HOWEVER THE RIDGE FLATTENS SATURDAY AS A SHORTWAVE ROLLS THROUGH. THIS SHOULD BE TEMPORARY AS THE LONG TERM MODEL SUITE THEN SHOWS A STRONGER AMPLIFICATION OF THE RIDGE TO COMMENCE ACROSS THE INTERMOUNTAIN WEST JUST BEYOND THIS EXTENDED PERIOD. FOR MONDAY NIGHT...WITH STRONG WARM/MOIST AIR ADVECTION IN THE LOWER LEVELS COMBINED WITH A COUPLE OF SHORTWAVES TRANSVERSING THROUGH VIA A SOUTHWEST FLOW ALOFT...THIS SHOULD BE ENOUGH TO PROMOTE CONVECTION THROUGH THE NIGHT. SURFACE DEWPOINTS IN THE UPPER 60S TO AROUND 70 WILL YIELD MUGGY CONDITIONS AND VERY WARM OVERNIGHT LOWS MONDAY NIGHT. THE STRONGEST SHORTWAVE SHIFTS THROUGH ON TUESDAY AS A SURFACE COLD FRONT MOVES FROM WEST TO EAST. EXPECTING THUNDERSTORMS LIKELY ALONG AND AHEAD OF THE FRONT. THE SCENARIO THAT APPEARS MOST LIKELY IS THUNDERSTORMS WILL BE ONGOING FROM MONDAY NIGHT AND CONTINUE FOR MOST OF TUESDAY INTO TUESDAY EVENING. THE COLD FRONT SHOULD CLEAR THE JAMES RIVER VALLEY BY 06Z WEDNESDAY. WEDNESDAY LOOKS MOSTLY DRY WITH THE EXCEPTION OF NORTH CENTRAL NORTH DAKOTA WHERE A SHORTWAVE WILL MOVE THROUGH PRODUCING A SLIGHT CHC OF SHOWERS/THUNDERSTORMS. RIDGING WEST OF NORTH DAKOTA AS MENTIONED ABOVE WILL PROMOTE DRY WEATHER FOR THURSDAY/FRIDAY...THEN A CHANCE FOR THUNDERSTORMS SATURDAY THROUGH SUNDAY WITH A SHORTWAVE MOVING THROUGH. WARMEST HIGH TEMPERATURES WILL BE TUESDAY WITH MID TO UPPER 80S ALONG WITH HUMID CONDITIONS. DRIER AIR/LOWER DEWPOINTS CAN BE EXPECTED FOR THE REST OF THE WEEK WITH HIGHS COOLING TO THE UPPER 70S NORTH AND LOWER 80S SOUTH THURSDAY THROUGH SATURDAY. OVERNIGHT LOWS IN THE 60S TO NEAR 70 TUESDAY MORNING...THEN UPPER 50S FOR THE REST OF THE LONG TERM PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 105 AM CDT MON JUN 24 2013 VFR CONDITIONS IN GENERAL ARE EXPECTED ACROSS WESTERN AND CENTRAL NORTH DAKOTA FOR THE 06 UTC TAF CYCLE. CANNOT RULE OUT PATCHY FOG LATE TONIGHT...HOWEVER...DUE TO UNCERTAINTY AND LOW COVERAGE...WILL LEAVE THE MENTION OUT OF THE TAFS FOR NOW. ON MONDAY THE MAIN THREAT WILL BE THE POTENTIAL FOR SEVERE THUNDERSTORMS AREA WIDE LATE MONDAY AFTERNOON AND THROUGH THE EVENING. FOR NOW GIVEN UNCERTAINTY...CODED AS VCTS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...NH LONG TERM...KS AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1149 PM CDT SUN JUN 23 2013 .UPDATE... ISSUED AT 1145 PM CDT SUN JUN 23 2013 THE SHOWERS IN THE DVL BASIN HAVE NOW DISSIPATED. REST OF THE NIGHT WILL BE DRY. KEPT LOWS AS FCST. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 313 PM CDT SUN JUN 23 2013 CONVECTION CHANCES CONTINUE TO BE THE PRIMARY FORECAST PROBLEM FOR THE PERIOD. WV LOOP SHOWS THE MAIN SHORTWAVE IS CURRENTLY IN THE PROCESS OF LIFTING THROUGH THE CWA ON ITS WAY INTO CANADA. THE MAIN SFC LOW IS ALREADY IN SOUTHERN MANITOBA...WITH ALL BUT THE FAR NORTHEASTERN CWA SEEING WESTERLY WINDS ON THE SOUTH SIDE OF THE LOW. THE RAIN BAND FROM THIS MORNING HAS LIFTING NORTH INTO CANADA...AND SOME CLEARING HAS BEEN GOING ON ALTHOUGH WITH PRETTY LOW CONVECTIVE TEMPS CU HAS REDEVELOPED RAPIDLY. THERE HAS BEEN A DECREASE IN MOISTURE AS THE WEST WINDS BRING IN DRIER AIR...BUT THERE IS STILL A DECENT AMOUNT OF HUMIDITY AND WITH SOME CLEARING CAPE HAS REACHED AROUND 1000 J/KG ACROSS THE CENTRAL CWA. WHILE THE BEST LIFT WILL BE QUICKLY MOVING OFF TO THE NORTH THIS EVENING...THERE IS ENOUGH INSTABILITY HANGING AROUND THAT CANNOT COMPLETELY RULE OUT THUNDERSTORM REDEVELOPMENT...AND THE RAP AND HRRR SHOW SIGNS OF THIS ALTHOUGH STRENGTH DOES NOT SEEM IMPRESSIVE AT THIS POINT. WILL KEEP SOME 30-60 POPS GOING MAINLY NORTH OF THE HIGHWAY 2 CORRIDOR THROUGH EARLY EVENING BEFORE WE GO DRY AFTER MIDNIGHT. MONDAY SHOULD BE FAIRLY QUIET WITH WEAK UPPER RIDGING BETWEEN SYSTEMS. WINDS WILL SHIFT BACK TO THE SOUTH AS A SFC TROUGH BEGINS TO DEEPEN OVER THE ROCKIES/WESTERN PLAINS. 850MB TEMPS CLIMB BACK UP TOWARDS THE UPPER TEENS C AND WITH PLENTY OF SUN WE SHOULD BE ABLE TO CLIMB INTO THE MID 80S ACROSS MOST OF THE AREA. THE QUIET CONDITIONS WILL BE SHORT LIVED AS MODELS SHOW SOME INDICATION OF A WEAK SHORTWAVE MOVING IN MONDAY NIGHT. THINK THERE COULD BE SOME STORMS MOVING IN FROM THE WEST MONDAY NIGHT...WITH THE MODELS SHOWING SOME ELEVATED INSTABILITY LIFTING INTO THE CWA OVERNIGHT. KEPT SOME POPS AROUND 30 PERCENT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 313 PM CDT SUN JUN 23 2013 THINK THAT THE BETTER CHANCES FOR MORE SIGNIFICANT STORMS WILL BE TUESDAY WHEN A FAIRLY STRONG SHORTWAVE TROUGH MOVES INTO THE DAKOTAS. THE SFC TROUGH AXIS WILL MOVE INTO CENTRAL ND...WITH SOUTHEASTERLY WINDS AHEAD OF IT AND GOOD LOW LEVEL CONVERGENCE. INSTABILITY WILL DEPEND ON EXACTLY ANYTHING OVERNIGHT EVOLVES...BUT THERE IS THE POSSIBILITY OF MORE THAN 2000 J/KG OF CAPE. CONTINUED TO KEEP FAIRLY HIGH POPS FOR THUNDERSTORMS TUESDAY INTO TUESDAY NIGHT...BUT IS A BIT EARLY FOR ANY SEVERE MENTION AT THIS TIME. SOME PRECIP MAY LINGER INTO WEDNESDAY MORNING...BUT OVERALL THERE SHOULD BE A DRYING TREND AS THE UPPER SHORTWAVE PULLS OFF TOWARDS THE GREAT LAKES. TEMPS SHOULD BE FAIRLY SEASONABLE IN THE LOW 80S. WEDNESDAY NIGHT TO SATURDAY NIGHT...MODELS IN GOOD AGREEMENT WITH RETROGRADING AND AMPLIFYING WESTERN CONUS RIDGE AND GREAT LAKES TROUGH AT 500MB. AS A RESULT NW FLOW ACROSS THE NORTHERN PLAINS WILL DEVELOP. THIS WILL MAKE FOR SEASONAL END OF JUNE TEMPERATURES AND NEARLY CLIMO POPS AS THE TIMING OF ANY WEAK SHORT WAVES FEATURE WILL NEED TO COINCIDE WITH PEAK HEATING TO INITIATE ANY DIURNALLY DRIVEN CONVECTION AND OVERALL COVERAGE IS EXPECTED TO BE LOW...THUS THE LOW POPS IN THE EXTENDED. .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1252 PM CDT SUN JUN 23 2013 LOW PRESSURE TRACKING ALMOST DUE NORTH ALONG RED RIVER NEAR HCO WITH TROUGH AND EDGE OF RAIN NOW THRU TVF. EXPECT MVFR CIGS TO CONTINUE TO IMPROVE WITH DRIER AIR MIXING IN ON WESTERLY GUSTS 20 TO 30KTS...SOME ISOLATED SHOWERS THIS AFTERNOON POSSIBLE...WITH VFR CONDITIONS EXPECTED THIS EVENING AND OVERNIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1145 PM CDT SUN JUN 23 2013 LTITLE CHANGE FROM PREV FCST. WINDS DOWN BACKING MORE SOUTH- SOUTHWEST IN MOST AREAS AND UNDER 10 KTS. IT WILL STAY THIS WAY TIL JUST PAST SUNRISE. BY 16Z EXPECT WINDS TO TURN A BIT MORE SOUTHWEST AND SOUNDINGS INDICATE A PRETTY GOOD MIXED LAYER SO WOULDNT BE SUPRISED TO SEE SOME GUSTS TO 20 KTS OR SO DURING PEAK HEATING MONDAY. VFR ALL DAY MONDAY WITH A FEW CU OR SOME CIRRUS MOVING IN. SOME AC MOVING INTO DVL-FAR REGIONS MON EARLY EVE. COULD BE SOME THUNDER BY 06Z TUE IN DVL-FAR BUT LEFT OUT SINCE VERY UNCERTAIN. && .HYDROLOGY... ISSUED AT 628 PM CDT SUN JUN 23 2013 NEW WARNINGS WERE DONE FOR THE BUFFALO RIVER AT SABIN AND DILWORTH FOR MINOR FLOODING. NEW WARNINGS ACROSS THE SOUTHERN VALLEY AT HARWOOD...WEST FARGO... KINDRED...ABERCROMBIE WITH AN INCREASE OF FLOODING TO MODERATE NOW EXPECTED AT WAHPETON AND FARGO AS THE AREA RIVERS RESPOND TO LAST NIGHTS RAINFALL OF ONE TO TWO INCHES ON ALREADY SATURATED SOILS. ALSO...MAPLETON WARNING WAS CANCELLED AS THE RIVER FELL BELOW FLOOD STAGE EARLIER TODAY. .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...JR LONG TERM...JR/JK AVIATION...RIDDLE HYDROLOGY...WJB/JK
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1233 AM CDT MON JUN 24 2013 .UPDATE... ISSUED AT 930 PM CDT SUN JUN 23 2013 LOW LEVEL JET STARTING TO HELP GENERATE SHOWERS AND THUNDERSTORMS FROM SOUTHEAST NEBRASKA INTO SOUTHERN IOWA. THESE WILL LIKELY CONTINUE TO DEVELOP NORTHWARD THROUGH THE EVENING. ALTHOUGH THE LOW LEVEL JET ORIENTATION WOULD SUGGEST THAT THE BEST COVERAGE WILL REMAIN SOUTHEAST OF OUR CWA. THIS IS SUPPORTED BY THE LATEST HRRR. HOWEVER DID GO AHEAD AND ADD IN CHANCE POPS ACROSS OUR FAR SOUTH...AS CANNOT COMPLETELY RULE OUT A STORM MAKING IT UP THERE AFTER ABOUT 08Z. ATTENTION THEN TURNS TO A WAVE COMING OUT OF THE ROCKIES. CONVECTION ACROSS NORTHEAST COLORADO SHOULD MOVE EAST THROUGH NEBRASKA OVERNIGHT. LIFT AND MOISTURE TRANSPORT AHEAD OF THIS WAVE SHOULD ALLOW CONVECTION TO MAINTAIN ITSELF. PREFER THE FASTER TIMING OF THE HRRR AS COMPARED TO THE NEW SLOWER 4KM NAM. THIS WOULD BRING THE THREAT INTO OUR SOUTHWEST AROUND 12Z...PUSHING NORTHEAST THROUGH THE MORNING HOURS. THIS FITS PRETTY WELL WITH THE GOING FORECAST...SO DID NOT MAKE ANY CHANGES TO POPS TOMORROW. AS MENTIONED BELOW...SEVERE THREAT SHOULD BE LOW WITH THIS MORNING CONVECTION...ALTHOUGH MUCAPE APPROACHING 2000 J/KG MAY BE ENOUGH FOR A FEW MARGINAL HAIL PRODUCING STORMS. TIMING OF THIS WAVE IS STILL UNCERTAIN. IF IT ENDS UP SLOWER AND WE ARE ABLE TO GET MORE DAYTIME HEATING AHEAD OF IT...THE SEVERE POTENTIAL WOULD PROBABLY INCREASE. STILL TOUGH TO SAY WHAT HAPPENS TOMORROW NIGHT UNTIL WE SEE WHAT THE FIRST WAVE DOES. SEEMS LIKELY STORMS FIRE IN THE WESTERN PLAINS DURING THE AFTERNOON WITH A SECOND WAVE. WHETHER THESE SURVIVE INTO OUR CWA IS STILL UP IN THE AIR...WITH MOST CONVECTION ALLOWING MODELS SAYING NO...AND THE LOWER RESOLUTION NAM...GFS AND EC SUGGESTING YES. PROBABLY DEPENDENT ON EXTENT OF DRYING...SUBSIDENCE AND CAPPING BEHIND THE FIRST WAVE. WILL JUST HAVE TO CONTINUE TO MONITOR TRENDS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 341 PM CDT SUN JUN 23 2013 A FRONTAL BOUNDARY CONTINUES TO PUSH THROUGH THE EASTERN PORTION OF THE CWA THIS AFTERNOON AND IS EXPECTED TO EXIT THE AREA LATE THIS AFTERNOON. CONVECTION WHICH WE EARLIER THOUGHT MIGHT DEVELOP IN OUR SOUTHEAST LATE THIS AFTERNOON NOW LOOKS TO HOLD OFF UNTIL LATER IN THE EVENING...WHEN THE BOUNDARY IS OUT OF OUR AREA...SO DO NOT ANTICIPATE ANY DEVELOPMENT OVER OUR AREA. OTHERWISE...THE REMAINDER OF THE NIGHT SHOULD BE QUIET AS WEAK HIGH PRESSURE BUILDS INTO THE REGION. THIS WILL ALLOW FOR WINDS TO DIE OFF...AND CANNOT RULE OUT SOME PATCHY FOG DEVELOPMENT WITH RECENT RAINS...THOUGH DID NOT INCLUDE IN FORECAST AT THIS POINT WITH LOW CONFIDENCE. THE FORECAST BECOMES MORE CHALLENGING LATER TONIGHT INTO MONDAY...WITH MODELS DIFFERING ON THE TIMING AND STRENGTH OF ANOTHER SHORT WAVE LIFTING UP OVER THE AREA DURING THE DAY ON MONDAY. MONDAYS SHORT WAVE IS CURRENTLY VISIBLE ON THE WATER VAPOR IMAGERY NEAR LAS VEGAS NV. THE GFS/GEM/4KM NAM AND SREF OFFER THE WETTER SOLUTIONS AS THEY ARE STRONGER IN THE MID LEVELS...WHILE THE ECMWF AND NAM KEEP IT DRY DURING THE DAYTIME HOURS...ALTHOUGH THE NAM DOES SHOW SOME WEAK PV ON THE 1.5 SURFACE. ELECTED TO GO WITH THE WETTER SOLUTIONS WITH 850 MB THETA E ADVECTION INCREASING OVER THE AREA AS THE LOW LEVEL JET CRANKS UP OUT OF EASTERN NEBRASKA. IN ADDITION THERE WILL BE INSTABILITY AND SOME SHEAR...THOUGH IN THE ABSENCE OF CAPPING WOULD EXPECT NO REAL UPDRAFT ENERGY TO BE STORED UP. SO OTHER THAN SOME POSSIBLE SMALL HAIL WOULD NOT EXPECT SEVERE STORMS DURING THE DAY. THIS OF COURSE WILL IMPACT HIGH TEMPERATURES...SO WENT WITH COOLER GUIDANCES WITH HIGHS INTO THE LOWER 80S NORTHEAST TO THE UPPER 80S ALONG THE MISSOURI RIVER CORRIDOR. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 341 PM CDT SUN JUN 23 2013 MONDAY NIGHT IS THE MOST ACTIVE PERIOD IN THE LONGER TERM. ANOTHER STRONGER SHORT WAVE FOLLOWS MONDAY WAVE...WHICH WATER VAPOR SHOWS CURRENTLY OFF OF THE CA COAST. INTERESTINGLY...THE HI RES MODELS WHICH ARE SO ACTIVE ON MONDAY LEAVE MONDAY NIGHT DRY. HOWEVER THE NAM AND ECMWF ARE WET...ESPECIALLY ALONG AND NORTH OF I 90. THE ECMWF HAS BEEN VERY CONSISTENT WITH THIS FEATURE FOR 4 OR 5 DAYS NOW. SO IT IS VERY HARD TO IGNORE. THE NAM IS STRONG WITH THE PV 1.5...AND ABUNDANT INSTABILITY AND WIND SHEAR CONTINUES. MOST OF THE RAINFALL WILL OCCUR IN THE EVENING HOURS...AGAIN WITH THE HIGHEST CHANCES FOR HEAVIER RAINFALL ALONG AND NORTH OF I 90. NAM PWATS IN THOSE AREAS AVERAGE 1.5 TO 2.0 INCHES AND SOME SEVERE WEATHER IS POSSIBLE GIVEN THE INSTABILITY PARAMETERS. THE WAVE QUICKLY EXITS AFTER MIDNIGHT...WHICH WILL LEAVE TUESDAY DRY AND VERY WARM AND HUMID. UPPER RIDGING THEN BUILDS AS ADVERTISED AND RETROGRADES WESTWARD BY LATE WEEK AND NEXT WEEKEND. A SURFACE BOUNDARY MOVES THROUGH OUR AREA LATE TUESDAY NIGHT SHIFTING OUR WINDS TO THE NORTHWEST FOR WEDNESDAY. WITH BETTER MIXING...TEMPERATURES WILL STILL BE QUITE WARM...WITH LESS HUMID CONDITIONS WEST OF I 29. AS THE UPPER RIDGE RETROGRADES TO THE WEST CREATING A HIGHLY AMPLIFIED PATTERN... IT STILL LOOKS AS THOUGH TEMPERATURES WILL START A COOLING TREND ON THURSDAY...LASTING THROUGH THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1231 AM CDT MON JUN 24 2013 ONE WAVE WHICH RECENTLY PUSHED PAST THE FOUR CORNERS WILL MOVE INTO THE AREA EARLY THIS MORNING. GIVEN THE LOW LEVEL JET...AND APPARENT BOUNDARY ACROSS SOUTHEAST/CENTRAL NEBRASKA...EXPECT A FEW STORMS TO DEVELOP ALONG WARM ADVECTIVE WING AND IMPACT KSUX AREA AFTER 09Z...AND THEN A BETTER COVERAGE OF SHOWERS/STORMS BY MORNING HOURS FOR KFSD AND KSUX...BUT EXITING NORTHEAST FAIRLY QUICKLY. UPSTREAM AND STRONGER WAVE UPSTREAM AROUND RENO NV WILL FOLLOW...AND WILL LIKELY RESULT IN ADDITIONAL CONVECTION ACROSS THE AREA...BUT FOR NOW HELD OFF MENTION UNTIL AFTER 00Z. PROBABILITY OF MVFR FOG IS FAIRLY LOW...LIKELY HIGHEST AROUND KSUX...BUT WILL ALSO HAVE INITIAL INCREASE IN CLOUDS FROM CONVECTION TO SOUTH...AND WILL NOT MENTION ON THIS FORECAST SET. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE...CHENARD SHORT TERM...JM LONG TERM...MJ AVIATION...08
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1223 AM CDT MON JUN 24 2013 .UPDATE... SEE UPDATED AVIATION DISCUSSION BELOW. WINDS HAVE GONE LIGHT LATE THIS EVENING UNDER CLEAR SKIES AND SURFACE HIGH PRESSURE RIDGING. THE WINDS WILL TURN SOUTH BEHIND THIS RETREATING HIGH PRESSURE AREA TONIGHT. ALREADY HAVE MID LEVEL WAA CLOUDS/ACCAS AND COOLING TOPS IN WY/SE MT LATE THIS EVENING MOVING QUICKLY EAST. THESE WILL CONTINUE TO MOVE EAST AND MAY BECOME HIGH BASED SHOWERS/THUNDER AS THEY MOVE INTO WESTERN SD AND INTO OUR WESTERN CWA LATER TONIGHT. THE LATEST HRRR MODEL SHOWS SOME SPOTTY QPF LATER TONIGHT. ALREADY HAVE IN SLIGHT CHANCES WEST IN THE CWA AFTER MIDNIGHT. && .PREVIOUS DISCUSSION... .SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT THE ACTIVE SUMMER PATTERN CONTINUES EARLY THIS WEEK AS RETURN FLOW MOISTURE AND INSTABILITY MAKE A QUICK RETURN TO THE WESTERN ZONES OVERNIGHT AND SPREADS EAST MONDAY AND MONDAY EVENING. MODELS ARE AGAIN OFFERING A CHALLENGING FORECAST WITH TIMING AND STRENGTH OF SHORTWAVES AND CONVECTION...BUT THUNDERSTORMS LOOK LIKE A GOOD BET MONDAY NIGHT MOST LOCATIONS AND AGAIN TUESDAY NIGHT IN THE EAST. SPC HAS AREA IN SLIGHT RISK FOR MONDAY NIGHT AND THE EASTERN PORTION FOR TUESDAY. DESPITE RISING HEIGHTS...DEEP SOUTHWEST FLOW ALOFT WILL CONTINUE TO EJECT SHORTWAVES INTO THE UPPER PLAINS. WITH INSTABILITY RETURN IN THE WEST LATE TONIGHT HAVE ADDED SMALL POPS TO THE FORECAST FOR AREAS ALONG AND WEST OF THE MISSOURI RIVER. HEAT...MOISTURE AND INSTABILITY WILL INCREASE THE NEXT FEW DAYS WITH TEMPS CLIMBING INTO THE UPPER 80S AND MID 90S BY TUESDAY. THE HEAT INDEX WILL CLIMB INTO THE MID TO UPPER 90S ON TUESDAY. AS MENTIONED ABOVE...MODELS IN ARE NOT IN VERY GOOD AGREEMENT WITH TIMING OF CONVECTION...BUT OVERALL FEEL CONFIDENT FOR THUNDERSTORMS FOR BOTH MONDAY AND TUESDAY EVENINGS...POSSIBLY SEVERE AS INSTABILITY INCREASES. .LONG TERM...WEDNESDAY THROUGH SUNDAY IT APPEARS THE THEMES RUNNING THROUGHOUT THE EXTENDED ARE WARM AND MOSTLY DRY. AT THIS POINT...POPS/WX MENTION DO NOT SHOW UP IN THE OUT PERIODS BASICALLY UNTIL SATURDAY LATE AFTERNOON/EARLY EVENING. UNTIL THEN...REBOUNDING MID/UPPER LEVEL HEIGHTS ARE FORECAST TO DEVELOP ACROSS THE WESTERN TWO-THIRDS OF THE CONUS STARTING WEDNESDAY AND PERSIST THROUGH THE END OF THE PERIOD. A LOW PRESSURE SYSTEM IS PROGGED TO TRY WORKING THROUGH THE TOP OF THE RIDGE...IN EFFECT...FLATTENING IT SOMEWHAT OVER THE WEEKEND AND BRINGING A SMALL CHANCE AT CONVECTION ACROSS THE CWA BY SATURDAY EVENING. AT THIS TIME...700HPA THERMAL PROGS ARE AT OR ABOVE +14C ON SATURDAY...SO IT WILL TAKE QUITE A BIT OF MOISTURE/INSTABILITY AND STRONG FORCING AROUND TO GET STORMS TO DEVELOP IN THAT WARM OF A MID-LEVEL ENVIRONMENT. SPEAKING OF WARM...WITH HEIGHTS RISING IN THE ATMOSPHERE...A GOOD CHUNK OF THE EXTENDED SHOULD BE LOOKING AT NEAR TO ABOVE NORMAL HIGH TEMPERATURES IN THE 80S AND 90S DURING THE MID TO LATE PORTIONS OF THE WEEK. && .AVIATION... 06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH TONIGHT AND MONDAY. AN UPPER LEVEL LOW PRESSURE TROUGH ALONG WITH RETURNING WAA WILL SPREAD MID LEVEL CLOUDS ACROSS THE REGION THROUGH MONDAY. WITH INSTABILITY ALSO RETURNING/INCREASING...SOME SHOWERS/THUNDERSTORMS SHOULD ALSO DEVELOP MAINLY LATE TONIGHT AND MONDAY. LEFT ANY MENTION OUT OF THE TERMINALS AT THIS TIME WITH THE UNCERTAINTY OF LOCATION AND TIMING INVOLVED. SOUTHEAST WINDS WILL ALSO BECOME BREEZY ON MONDAY AT 15 TO 20 KNOTS WITH HIGHER GUSTS AT MBG AND PIR. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...WISE SHORT TERM...DORN LONG TERM...SCARLETT AVIATION...WISE WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
310 AM EDT MON JUN 24 2013 .SHORT TERM (TODAY AND TONIGHT)... SOME SHOWERS ARE PERSISTING IN THE SOUTHERN HALF OF THE AREA THIS MORNING...AND THE RUC SHOWS AN AREA OF LOW LEVEL MOISTURE CONVERGENCE IN THIS AREA. THE RUC SHOWS THIS WEAKENING BY 12Z...BUT WILL INCLUDE A SLIGHT CHANCE POP IN ALL AREAS THROUGH THE MORNING. IN THE AFTERNOON...WE WILL SEE A REMNANT VORT MAX FROM CONVECTION OVER W KY ENTER THE AREA...AND THE NAM DEVELOPS CONVECTION IN MIDDLE TN AND THE PLATEAU ALONG AN OUTFLOW BOUNDARY. INSTABILITY APPEARS GREATEST IN THAT AREA...SO WILL HAVE HIGHEST POPS WEST TODAY...BUT STILL IN THE CHANCE RANGE EVERYWHERE. WILL CONTINUE WITH PERSISTENCE FOR TEMPERATURES TODAY AND TONIGHT. .LONG TERM (TUESDAY THROUGH SUNDAY)... BERMUDA RIDGE WILL REMAIN OVER THE SOUTHEAST UNITED STATES THROUGH MID-WEEK. GFS AND NAM SHOW PWS AND INSTABILITY INCREASING TO 1.4 TO 1.6 INCHES FOR TUESDAY AND WEDNESDAY..SO COVERAGE AND INTENSITY OF STORMS WILL LIKELY INCREASE TO SCATTERED. FOR THURSDAY INTO NEXT WEEKEND...RIDGING OVER THE SOUTHERN APPALACHIANS WILL WEAKEN ALLOWING A SERIES OF UPPER SHORT- WAVES OVER THE GREAT LAKES INTO THE NORTHEAST TO CARVE OUT A LONG- WAVE TROUGH OVER THE EASTERN UNITED STATES. LOOKING AT INSTABILITY AND UPPER DYNAMICS...BEST CHANCE OF MORE WIDESPREAD STRONG TO SEVERE STORMS STILL POINT TO THURSDAY AND WILL MENTION IN THE HWO. A COLD FRONT MOVING THROUGH SATURDAY WILL BRING IN DRIER DEWPOINTS FOR SUNDAY. AS FOR TEMPERATURES...GENERALLY FOLLOWED GFS NUMBERS CLOSELY..EXCEPT FOR THE LATTER HALF OF THE WEEK. LOWER THICKNESS AND GREATER COVERAGE OF CLOUDS AND CONVECTION DOES NOT WARRANT THE GFS HIGHS..SO UNDER-CUT A DEGREE OR TWO. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 88 68 90 70 90 / 40 30 30 10 30 KNOXVILLE MCGHEE TYSON AIRPORT, TN 87 67 89 69 90 / 40 30 20 10 30 OAK RIDGE, TN 86 67 89 69 90 / 40 20 20 10 30 TRI CITIES AIRPORT, TN 87 64 88 63 89 / 30 20 30 10 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DGS/DH
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1128 PM CDT SUN JUN 23 2013 .AVIATION... VFR EXPECTED TO DOMINATE...THOUGH WRF/NAM AND RAP SOLUTIONS CONTINUE TO INDICATE NEAR-SATURATION OCCURRING BETWEEN 11Z-15Z AT KLBB MONDAY MORNING NEAR H850 MB OR CLOSE TO 2000 FEET ABOVE THE GROUND. SLIGHT UPGRADE IN WORDING TO A TEMPO SCATTERED LOW CLOUD GROUP FOR KLBB DURING THIS PERIOD. FOR MONDAY AFTERNOON...LATEST SOLUTIONS IN-LINE WITH OUR THINKING THAT THE SURFACE DRY-LINE SHOULD NOT MAKE AS MUCH HEADWAY TO THE EAST...REMAINING WEST-NORTHWEST OF KLBB. THUNDER CHANCES TOO LIMITED TO INCLUDE IN THIS TAF EDITION. RMCQUEEN && .PREV DISCUSSION... /ISSUED 924 PM CDT SUN JUN 23 2013/ UPDATE... SHOWER CHANCES HAVE DWINDLED MOST OF THE AREA AS THE DRY-LINE RETREATED RAPIDLY TO THE WEST THIS EVENING. RETAINED ISOLATED MENTION ACROSS THE NORTHWEST...AND REMOVED THUNDER MENTION ELSEWHERE. RMCQUEEN PREV DISCUSSION... /ISSUED 717 PM CDT SUN JUN 23 2013/ UPDATE... HIGH-BASED SHOWERS HAVE BEEN LATE TO DEVELOP...POSSIBLY DEVELOPED AS DRY-LINE RETREATED INTO THE WESTERN SOUTH PLAINS. AS SUCH... SOME DOUBT WHETHER THESE WEAK CELLS WILL BE ABLE TO SURVIVE AS THEY TREK TO THE EAST-NORTHEAST. AND ALREADY WE ARE SEEING WEAKENING TREND. RMCQUEEN AVIATION... ISOLATED HIGH-BASED SHOWERS HAVE DEVELOPED LATE ABOUT 20 MILES WEST OF KLBB...AFTER WE ALREADY ISSUED THE 00Z TAF. WILL STUDY CLOSE THE NEED FOR ADDING SHOWER OR THUNDER MENTION FOR KLBB. VFR CONDITIONS OTHERWISE EXPECTED TO DOMINATE WITH SOUTHWEST FLOW ALOFT AND A SURFACE TROUGH. STILL OUTSIDE RISK OF MVFR CEILINGS AT KLBB EARLY MONDAY MORNING. RMCQUEEN PREV DISCUSSION... /ISSUED 314 PM CDT SUN JUN 23 2013/ SHORT TERM... LITTLE CHANGE IN THE LARGE SCALE PATTERN OR OVERALL THINKING WITH REGARDS TO THE FORECAST TONIGHT INTO MONDAY...WITH BIGGEST CONCERN REVOLVING AROUND STORM CHANCES THIS EVENING AND AGAIN LATE IN THE DAY MONDAY. THE REGION CONTINUES TO RESIDE ON THE THE SOUTHERN FRINGE OF SOUTHWESTERLY FLOW ALOFT WITH SEVERAL SUBTLE WEAKNESSES MOVING THROUGH THE FLOW AND SKIRTING THE AREA PERHAPS PROVIDING WEAK SUPPORT...THOUGH NWP IS MIXED WITH THIS SIGNAL. REGARDLESS..STRONG HEATING IS TAKING PLACE WITH A SFC TROUGH STRETCHING FROM THE CENTRAL TEXAS PANHANDLE INTO SOUTHEAST NEW MEXICO. AS OF 19Z...LIGHT SOUTHWESTERLY WINDS AND DEWPOINTS FALLING INTO THE 40S AND 30S HAVE INVADED THE WESTERN ZONES...SETTING UP A DIFFUSE DRYLINE...WITH DEWPOINTS IN THE 50S ACROSS THE CENTRAL ZONES AND SOME LOWER 60S HOLDING OFF THE CAPROCK. DEEP MIXING AND CONVERGENCE ALONG THE DRYLINE MAY BE ENOUGH TO TRIGGER ISOLATED TO WIDELY SCATTERED CONVECTION THROUGH EARLY THIS EVENING. IN ADDITION...THE TTU-WRF AND HRRR SUGGEST OROGRAPHIC FORCING NEAR CAPROCK CANYONS MAY BE ENOUGH TO INITIATE A STORM THERE. LATEST OBJECTIVE ANALYSIS SHOWS MLCAPES AOA 2000 J/KG EAST OF THE DRYLINE...THOUGH WITH SOME INHIBITION YET TO BE OVERCOME. DEEP LAYER SHEAR IS NOT OVERLY IMPRESSIVE...AROUND 25 KNOTS...PERHAPS PUSHING TOWARD 30 KNOTS BY THIS EVENING. THAT SAID...IF STORMS DO DEVELOP...STRONG INSTABILITY COUPLED WITH THE MODEST SHEAR WOULD SUPPORT A SEVERE THREAT. IN ADDITION...SLOW STORM MOTIONS AND PWATS HOLDING IN EXCESS OF 1 INCH WILL SUPPORT A LOCALLY HEAVY RAIN THREAT. ANY CONVECTION SHOULD FADE BY LATE THIS EVENING AS THE LOWER ATMOSPHERE COOLS. HOWEVER...A SIMILAR SETUP WILL PRESENT ITSELF AGAIN ON MONDAY THOUGH THE MOST RECENT SOLUTIONS DO SUGGEST THE SFC TROUGH/DRYLINE WILL HALT FURTHER TO THE WEST NEAR THE TX/NM LINE DURING THE AFTERNOON...KEEPING THE BEST STORM CHANCES A LITTLE FURTHER WEST AS WELL. BREEZY SOUTHERLY SFC WINDS OVERNIGHT /BENEATH A MODEST LLJ/ WILL YIELD ANOTHER MILD NIGHT WITH LOWS BY MORNING RANGING FROM THE MID-60S NORTHWEST TO MID-70S SOUTHEAST. THESE SOUTHERLY WINDS MAY TRANSPORT SLIGHTLY IMPROVED LOW-LEVEL MOISTURE FROM WHAT WE SAW THIS MORNING AND COULD EVEN RESULT IN A FEW LOW CLOUDS TOWARD MORNING. ANOTHER HOT DAY WILL FOLLOW WITH HIGHS WELL INTO THE 90S. TEMPERATURES MAY ACTUALLY STAY A FEW DEGREES COOLER ACROSS THE WESTERN ZONES WHERE MOISTURE LEVELS SHOULD STAY HIGHER THAN TODAY. ONGOING FORECAST HAD ALL OF THIS WELL IN HAND AND ONLY MINOR ADJUSTMENTS WERE MADE TO THE FORECAST GRIDS. LONG TERM... UPPER RIDGE TO BEGIN BUILDING OVER THE ROCKIES TUESDAY WITH INCREASING HEIGHTS AND MID LEVEL TEMPS LIKELY SHUTTING DOWN DIURNAL PRECIP CHANCES...ALTHOUGH MODELS GIVING SOME INDICATION OF ISOLATED HIGH-BASED STORMS DURING THE LATE AFTERNOON...A POSSIBILITY TOO REMOTE ATTM TO INCREASE POPS TO SLIGHT CHANCE CATEGORY. OTHER ISSUE IS PRECIP CHANCES FRIDAY THROUGH SUNDAY. PREVIOUS MODEL RUNS INDICATED POTENTIAL FOR A COLD FRONT AND/OR UPPER LEVEL DISTURBANCES TO MOVE SWD DOWN THE PLAINS ON THE EAST SIDE OF THE UPPER RIDGE. THIS MORNING RUNS NOW PUSHING A PORTION OF THE RIDGE EWD ALL THE WAY TOWARD THE LOWER MISSISSIPPI VALLEY WHICH WOULD KEEP PRECIP MECHANISMS SHUT DOWN. WITH POPS ALREADY BELOW MENTION DURING THAT PERIOD...WILL KEEP THEM THERE WITH JUST SOME SLIGHT MASSAGING OF THOSE SUB-15 PCT POPS. THE POTENTIAL FOR THE RIDGE TO BUILD EWD ALSO MEANS TEMPS WARMER THAN INDICATED IN LAST SEVERAL FCST CYCLES AND WILL NUDGE UPWARDS BASICALLY KEEPING HIGHS IN THE UPPER 90S ON THE CAPROCK AND NEAR 100 OFF THE CAP THROUGH THE PERIOD WHILE OVERNIGHT LOWS GENERALLY MID 60S TO NEAR 70 ON THE CAP TO LOWER 70S OFF. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 66 95 65 99 66 / 20 20 20 10 10 TULIA 68 94 68 99 67 / 20 20 20 10 10 PLAINVIEW 70 95 69 99 69 / 20 20 20 10 10 LEVELLAND 67 95 68 99 69 / 20 20 20 10 10 LUBBOCK 70 95 71 99 72 / 20 20 20 10 10 DENVER CITY 68 95 69 99 69 / 20 20 20 10 10 BROWNFIELD 66 96 68 99 69 / 20 20 20 10 10 CHILDRESS 73 97 72 100 73 / 20 10 10 10 10 SPUR 71 96 71 99 72 / 10 10 10 10 10 ASPERMONT 75 98 73 99 74 / 10 10 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 05/99/05
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1117 PM CDT SUN JUN 23 2013 .AVIATION... 06Z TAFS...BREEZY SOUTHERLY WINDS WILL BE THE RULE THROUGH THE NEXT 24 HOURS...WITH GUSTS AROUND 30 KTS EXPECTED LATE MONDAY MORNING INTO MONDAY EVENING. A FEW SHOWERS ARE CURRENTLY SLOWLY MOVING TOWARD KAMA. STILL PRETTY LOW CONFIDENCE THAT THEY/LL REACH THE TERMINAL BEFORE DISSIPATING...AND EVEN IF THEY DO...IMPACTS WILL BE MINIMAL. THUNDERSTORMS WILL ONCE AGAIN BE POSSIBLE LATE MONDAY AFTERNOON AND EVENING...BUT CONFIDENCE IN THESE DIRECTLY IMPACTING A TERMINAL IS TOO LOW TO MENTION ATTM. VFR CONDITIONS ANTICIPATED OUTSIDE OF ANY THUNDERSTORMS. NOTE TO USERS OF SURFACE OBSERVATION FROM RICK HUSBAND INTERNATIONAL AIRPORT KAMA...COMMUNICATIONS PROBLEM WITH DATA LINE HAS PREVENTED LONG-LINE DISSEMINATION OF SURFACE OBS. DATA COLLECTION PLATFORM AT KAMA ASOS IS FUNCTIONING PROPERLY WITH CONTINUOUS MONITORING OF ALL ELEMENTS BY AMARILLO NATIONAL WEATHER SERVICE FORECAST STAFF. KB && .PREV DISCUSSION... /ISSUED 952 PM CDT SUN JUN 23 2013/ UPDATE... SHORTWAVE OVER SOUTHEASTERN AND EASTERN NEW MEXICO IN THE SOUTHWESTERLY UPPER FLOW ACROSS THE PANHANDLES ALLOWING FOR ADDITIONAL CONVECTION TO DEVELOP IN THE FAR EASTERN PLAINS OF NEW MEXICO MOVING NORTHEAST INTO THE SOUTHWESTERN TEXAS PANHANDLE. EXPANDED THE POPS THROUGH 06Z MONDAY A LITTLE FURTHER WESTWARD TO ACCOUNT FOR THIS ROUND OF CONVECTION. SHORT RANGE MODELS IN GOOD AGREEMENT SHOWING CONVECTION DEVELOPING ACROSS THE NORTHEAST TEXAS AND EASTERN OKLAHOMA PANHANDLES TOWARD 09Z MONDAY. INTRODUCED THE 10 POP RULE OVER THE EASTERN SECTIONS OF THE PANHANDLES TO ACCOUNT FOR THIS POSSIBILITY. DID NOTICE A LONE THUNDERSTORM ACROSS THE SOUTHEASTERN TEXAS PANHANDLE LAST NIGHT AROUND 09Z SUNDAY OR SO...AND CANNOT RULE OUT A SIMILAR SCENARIO ACROSS THE NORTHEASTERN OR EASTERN SECTIONS OF THE FORECAST AREA LATER TONIGHT. LOW LEVEL JET ACROSS THE EASTERN PANHANDLES LATE TONIGHT MAY ALSO HELP ADDITIONAL CONVECTION TO DEVELOP LATE TONIGHT. ADJUSTED WIND AND SKY GRIDS TONIGHT...AND ALSO POPULATED THE SMOKE MANAGEMENT GRIDS WITH THE LATEST NAM DATA AND UPDATED THE LAL AND 20 FOOT WIND GRIDS. OTHERWISE...NO OTHER CHANGES MADE TO PREVIOUS FORECAST AND GRIDS. ALL PUBLIC AND FIRE WEATHER PRODUCTS HAVE BEEN UPDATED AND SENT. SCHNEIDER PREV DISCUSSION... /ISSUED 319 PM CDT SUN JUN 23 2013/ DISCUSSION... JUST ONE MORE DAY OF THIS ACTIVE WEATHER PATTERN THAT THE REGION HAS BEEN UNDER FOR OVER A WEEK NOW. TONIGHT INTO TOMORROW...PRECIP CHANCES...THOUGH MENTIONABLE...CONTINUE TO DECLINE AS DRY AIR ADVECTION CONTINUES. PRECIPITABLE WATER VALUES ON THIS MORNINGS SOUNDING SHOW 0.79 INCHES...WHICH IS 92 PERCENT OF NORMAL...BUT A FAR CRY FROM THE 1 PLUS INCH VALUES WE/VE SEEN LATELY. IN ADDITION...IN THE WAKE OF THE UPPER LEVEL TROUGH THAT MOVE THROUGH EARLY THIS MORNING...THERE IS SOME UPPER LEVEL SHORT WAVE RIDGING OVER THE REGION. THIS SHOULD KEEP COVERAGE OF STORMS VERY LIMITED. HOWEVER...IT IS INTERESTING TO NOTE THAT THE RAP HIGH RESOLUTION MODEL SHOWS MORE COVERAGE THAN YESTERDAY. IF ANY STORMS DEVELOP EITHER THIS AFTERNOON OR TOMORROW...THE POTENTIAL REMAINS FOR MARGINALLY SEVERE HAIL AND DRY AND HYBRID DOWNBURSTS LEADING TO STRONG WINDS. TUESDAY THROUGH THURSDAY...INCREASING CONFIDENCE WITH VERY GOOD MODEL AGREEMENT AND CONSISTENCY THAT THE RIDGE WILL BUILD OVER THE SOUTHWEST THROUGH THIS PERIOD BRINGING A DRY AND HOT WEATHER PATTERN THROUGH THE WEEK. STAYED CLOSE TO THE PREVIOUS FORECAST STILL FAVORING HIGHER MAX TEMPS IN THE NORTHWESTERN PANHANDLES...WHICH HAVE SEEN VERY LITTLE RAIN...WHILE KEEPING THE SOUTHEASTERN TX PANHANDLE A FEW DEGREES LOWER DUE TO THE WET SOIL CONDITIONS. HOWEVER...BY THE END OF THE WEEK...THESE DIFFERENCES MAY BE NEGLIGIBLE AS THE SOILS DRY. FRIDAY THROUGH SUNDAY...MODELS CONTINUED THE TREND OF SHOWING A PERSISTENT RIDGE CONTINUING THROUGH THIS PERIOD. THE COLD FRONT WHICH WAS SHOWN IN THE GFS TO ARRIVE ON FRIDAY...HAS ALL BUT DISAPPEARED IN THE 12Z RUN. THUS...STAYED CLOSE TO THE PREVIOUS FORECAST WITH HOT AND DRY WEATHER CONTINUING THROUGH THE WEEK. JOHNSON FIRE WEATHER... ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS MAY OCCUR TOMORROW IN THE WESTERN OKLAHOMA AND FAR NORTHWESTERN TEXAS PANHANDLES...THOUGH UNCERTAINTY REMAINS. MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE BELOW 15 PERCENT. HOWEVER...THOUGH WINDS ARE EXPECTED TO BE NEAR 20 MPH...IT IS UNCERTAIN IF THE SURFACE TROUGH WHICH RESULTED IN LIGHTER WINDS TODAY WILL BE A FACTOR TOMORROW AS WELL. THOUGH MINIMUM RELATIVE HUMIDITY VALUES WILL DROP BELOW 20 THROUGH THE REMAINDER OF THE WEEK...AS WE SEE A DRIER PATTERN...NO ADDITIONAL ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED AT THIS TIME AS WINDS SHOULD BE LIGHT. JOHNSON && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 08/11
AREA FORECAST DISCUSSION
NWS SPOKANE WA
224 AM PDT Mon Jun 24 2013 .SYNOPSIS... A wet pattern will continue across the Inland Northwest through mid week...with frequent showers and scattered thunderstorms common. The weather the second half of the week will be dramatically different as a warming and drying trend quickly develops by late week. Summer-like temperatures will be possible by the weekend. && .DISCUSSION... Today and tonight...Offshore low pressure buttressed against interior ridging with an axis positioned over Eastern Montana is allowing a moist and very dynamic southwest flow of moisture and energy to continue to pass through Eastern Washington and Northern Idaho. Negatively tilted shortwaves ejecting up through this flow have enough energy to merit not only high pops and moderate QPF for rain but also the mention of thunderstorms. Recent HRRR model runs hint at once the elevated forced convective showers and thunderstorms pass associated with the largest baroclinic negatively tilted frontal zone passing through right now there will be not so much a break in the activity but a decreasing trend between the time when the elevated convection either exits into Canada or erodes/weakens some along its back trailing edges and the time near 18Z and beyond where surface based convection is expected to start filling in the breaks. Therefore the forecast will remain cluttered with moderate to high pops, QPF, along with some mention of thunderstorms that decreases substantially with loss of daytime heating allowing the surface based convection to subside...especially noted after 6Z tonight. /Pelatti Tues through Fri Nt: This four-day period will be the transition period characterized by wet weather Tue and Wed, then by a rapid warming and drying trend Thurs and Fri. The primary concern will be how much pcpn will fall in the mtn zones of Nrn Wa, the Id Panhandle and the East Slopes of the Cascades. Three-day model guidance QPF is depositing (through about Wed) big ranges anywhere from 0.60-1.50 inches for these zones... with the SREF the least and the GFS the highest amnts. A complicating factor in our pcpn amnt fcst is the number of quick-moving waves that track across the Pac Nw through mid-week. There are at least four subtle features (depending on the model), all of which contain a decent SW moisture tap, with pwat values averaging around one inch. The latest TPW loop shows a nearly SW-to-NE plume of 200% of normal values aimed at Nrn Calif. Our waves should be able to tap into at least 100-150% values. Adding to the complexity of the wide- ranging rainfall amnts is the element of instability, especially late afternoon. This will be the dominating factor that will produce wide-ranging rainfall amnts over very short distances. Streams that will be affected most will be those across NE WA and the N Id Panhandle...especially where the recent heavy pcpn fell the last couple weeks...as well as the Stehekin River near the Cascade crest.bz Saturday through Monday...A ridge of high pressure will build north near the Inland Northwest, bringing with it drying conditions and above normal temperatures. The extended models are consistent in building a ridge into the region, but how amplified the ridge is and its placement are still in question. The difference is forecasting temperatures in the 90s to temperatures a little "cooler" in the 80s. Previous forecasts had lowered temperatures a tad on Saturday and did not see any reason to deviate from this. Until a little better consistency occurs, the forecast will trend to the ridge building into eastern Washington and the Idaho panhandle a little more each day, and thus warming temperatures a few degrees each day. Precipitation chances remain near nil, except for early Saturday where a lingering shower or thunderstorm may occur over Idaho panhandle. ty && .AVIATION... 06Z TAFS: Conditions will continue to deteriorate across the region as a negatively tilted trough interacts with deep moisture over the region to produce thickening and lowering ceilings with widespread rain through about 16Z as the area of moisture moves from southwest to northeast through the interior Pacific Northwest. Expect MVFR ceilings at most TAF sites at times with improving conditions with higher CIGS after 18Z Monday. TC && .PRELIMINARY POINT TEMPS/POPS... Spokane 67 53 66 52 73 54 / 90 80 80 50 20 10 Coeur d`Alene 66 55 66 52 73 53 / 100 80 80 50 20 20 Pullman 66 52 66 51 74 52 / 70 60 70 50 20 10 Lewiston 71 57 74 57 80 58 / 70 60 60 60 30 20 Colville 71 54 70 51 75 52 / 100 70 80 60 20 20 Sandpoint 66 54 67 51 71 52 / 100 80 90 60 30 20 Kellogg 63 52 63 51 69 52 / 80 80 80 50 30 20 Moses Lake 74 58 69 56 80 58 / 50 30 50 20 20 10 Wenatchee 74 57 69 57 79 60 / 50 30 50 20 20 10 Omak 73 56 70 53 77 54 / 70 50 60 30 20 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND TUESDAY ISSUED AT 444 AM CDT MON JUN 24 2013 THE CONTINUING SAGA ON WHERE AND WHEN FOR CONVECTION CONTINUES THIS MORNING. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY HINT AT WEAK BOUNDARY OVER NORTHEAST WI SEEN IN DEW POINTS. AREA OF DISORGANIZED TSTMS MOVING NORTH THROUGH IA AND WESTERN IL. STARTING TO SEE MORE MOVEMENT TO EAST OVER IL IN LATEST SCANS WHICH WOULD GO WITH MODELS PROJECTION OF LLVL JET SHIFTING MORE TO THE WEST AND WEAKENING BY 12Z. HRRR SEEMS TO HAVE BEST HANDLE ON CURRENT TRENDS...SHOWING ONLY SPOTTY CONVECTION OVER CWA TODAY MAINLY OVER THE SOUTH HALF. ALL MODELS STILL SHOWING VARIETY OF SOLUTIONS IN QPF PATTERN THROUGH THIS PERIOD. HAVE TRENDED TOWARD NAM TODAY GIVEN DRIER AIR WORKING IN AS SEEN IN SIG DROP IN PWATS ON MSP SOUNDING LAST EVENING. SFC BASED INSTABILITY STILL SIG 1-2K...THOUGH NOT SEEING ANY REAL TRIGGER/LIFT TODAY. WENT WITH SLIGHTS FOR LATE DAY CONVECTION SOUTH AND EAST ALONG LAKE BREEZE BOUNDARY. FORCING AND MOISTURE WORKS BACK INTO THE AREA THIS EVENING WITH STRENGTHENING LLVL FLOW POINTING INTO SOUTHWEST WI AFTER 06Z. ALSO SEEING SOME SUPPORT FROM RRQ OF JET MAX MOVING THROUGH LAKE SUPERIOR REGION. WILL GO WITH INCREASING CHANCE POPS TONIGHT HIGH CHANCE POPS TUE AS FGEN/ISENTROPIC LIFT MAXIMIZED OVER CWA FROM 12Z TO 18Z TUES. CWA REMAINS IN SLIGHT RISK AREA ON TUE. SHEAR BETTER SOUTH FOR SOME WIND CONCERNS. WBZERO HGTS RATHER HIGH FOR LARGE HAIL. WITH PWATS RETURNING TO 1.5 TO 2 INCHES AGAIN HEAVY RAIN MORE OF CONCERN. .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY ISSUED AT 444 AM CDT MON JUN 24 2013 500MB RIDGE EXPECTED TO BUILD ACROSS THE WESTERN UNITED STATES WHILE UPPER TROUGH DEEPENS AND POSSIBLY CLOSES OFF ACROSS THE WESTERN GREAT LAKES BY THE END OF THE WORK WEEK INTO NEXT WEEKEND. FORECAST ISSUES ALREADY AT THE START OF THE PERIOD TUESDAY NIGHT. HAVE CONCERNS ON THE PLACEMENT OF CONVECTION TUESDAY EVENING ACROSS NORTHERN WISCONSIN. BELIEF IS THAT THE AXIS OF HEAVIER PRECIPITATION TOO FAR NORTH. THINK BAND WILL BE FURTHER SOUTH AS FIRST COMPLEX OF STORMS LATE MONDAY NIGHT AND TUESDAY WILL PUSH AN OUTFLOW BOUNDARY SOUTHWARD THAN WHAT THE MODELS SHOW...SIMILAR TOO WHAT HAPPENED A FEW DAYS AGO. GFS QPF FIELD SEEMS REASONABLE BASED ON MY CURRENT THINKING. THIS COULD AFFECT THE RAIN CHANCES ACROSS THE NORTH TUESDAY EVENING. SOUTHERN SECTIONS OF THE FORECAST AREA WILL BE CLOSE ENOUGH TO STILL WARRANT LIKELY CHANCES. 500MB TROUGH SWINGS INTO THE AREA TOWARDS 12Z WEDNESDAY...WARRANTING LIKELY POPS EVEN ACROSS THE NORTH. UPPER TROUGH WILL SWING ACROSS THE AREA ON WEDNESDAY. RAISED POPS TO 50 TO 55 PERCENT...AND MAY BUMP THEM UP A LITTLE MORE BEFORE FORECAST ISSUANCE. THE UPPER TROUGH SHOULD SWING EAST INTO LOWER MICHIGAN WEDNESDAY NIGHT. THERE WILL STILL BE SOME LINGERING EVENING SHOWERS AND A FEW STORMS. MID LEVEL LAPSE RATES NOT IMPRESSIVE...THEREFORE ONLY EXPECTED ISOLATED NATURE OF ANY THUNDERSTORMS WEDNESDAY EVENING. NORTHWEST FLOW ALOFT WILL CONTINUE THURSDAY AND FRIDAY...ALTHOUGH A DEEPER 500MB TROUGH WILL SWING ACROSS THE AREA FRIDAY AFTERNOON AND FRIDAY NIGHT. WILL CONTINUE THE SMALL CHANCES FOR SHOWERS SATURDAY... BUT NOT TOO OPTIMISTIC WE WOULD SEE THEM AT THIS TIME SINCE UPPER TROUGH WILL WELL EAST OF THE AREA WITH BUILDING HEIGHTS. CANADIAN HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN ON SUNDAY...ALTHOUGH COULD NOT RULE OUT A FEW ISOLATED SHOWERS SUNDAY AFTERNOON. FOR THE MOST PART...VERIFICATION DATA HAS SHOWN WE AND NUMERICAL GUIDANCE HAS BEEN TOO WARM OF LATE. DID NUDGE TEMPERATURES DOWN A DEGREE OR TWO MOST PERIODS. WILL NEED TO WATCH WEDNESDAY...IF IT STAYS CLOUDY AND THERE IS A LOT OF RAIN AROUND DURING THE DAY... TEMPERATURES COULD STAY IN THE 70S. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1122 PM CDT SUN JUN 23 2013 GETTING A HANDLE ON PCPN TRENDS HAS BEEN A TOUGH TASK OVER THE PAST FEW DAYS...SO OVERALL CONFIDENCE REMAINS LOW. REGARDLESS... CURRENT INDICATIONS ARE THAT THE REST OF TONIGHT AND MUCH OF MONDAY SHOULD BE DRY. SOME DRIER AIR WILL CONTINUE TO OVERSPREAD NORTHERN WI TONIGHT...AND REMAIN IN PLACE ON MONDAY. WILL STILL NEED TO MONITOR FOR POSSIBLE CONVECTIVE DEVELOPMENT ALONG ANY WEAK BOUNDARIES DURING THE AFTERNOON...BUT CONFIDENCE IS TOO LOW TO MENTION IN THE TAFS. BEST ESTIMATE RIGHT NOW IS THAT SOME CONVECTION WILL FIRE MONDAY NIGHT...AS A WEAK UPPER DISTURBANCE TRACKS THROUGH THE AREA AND A SOUTHWESTERLY LOW-LEVEL JET REDEVELOPS. THERE IS SOME POTENTIAL FOR FOG LATE TONIGHT...ALTHOUGH WILL ONLY MENTION MVFR VSBYS...EXCEPT AT RHI WHERE SOME IFR CONDITIONS MAY OCCUR. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....TE LONG TERM......ECKBERG AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
415 AM CDT MON JUN 24 2013 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 415 AM CDT MON JUN 24 2013 06Z DATA ANALYSIS HAD LOW PRESSURE OVER LK WINNIPEG AND OVER THE OK/TX PANHANDLE AREA...WITH A WEAK RIDGE OF HIGH PRESSURE IN BETWEEN ACROSS SD TO IA. FRONTAL BOUNDARY/TROUGH FROM THE TX/OK LOW WAS ACROSS KS TO NORTHERN MO. WARM/MOISTURE ADVECTION/THETA-E CONVERGENCE OVER THIS BOUNDARY FOCUSED FROM EASTERN CO TO SOUTHERN IA...WHERE CONVECTION WAS FIRING EARLY THIS MORNING. THE FCST AREA AND REST OF WI/MN GETTING A NEEDED BREAK FROM THE SHRA/TSRA SO FAR SUNDAY THRU THIS MORNING...BEING NORTH/EAST OF THE SFC-700MB RIDGE AXIS. INITIALIZATIONS OF 24.00Z MODELS BETTER THAN THE PAST COUPLE 00Z CYCLES...THIS EXCEPT FOR THE GFS TOO HIGH ON SFC DEW POINTS OVER MUCH OF THE MID/UPPER MS VALLEY. EVEN WITH TIGHTER/BETTER INITIALIZATIONS...SOLUTIONS CONTINUE TO HAVE MESO-SCALE DIFFERENCES WHICH IMPACT THE SENSIBLE WEATHER IN THE SHORT TERM. DPROG/DT OF 500MB HGTS AT 24.00Z SHOWED THE MODEL RUNS OF 22.00Z AND 23.00Z VERIFIED WELL ACROSS NOAM/EASTERN PAC...FAVORING STRONGER OF EARLIER RUNS WITH THE TROUGH/ENERGY NEAR LK WINNIPEG AND THE TROUGHING OVER CA. MODEL CONSENSUS REMAINS GOOD WITH THE LARGER SCALE FEATURES TODAY THRU TUE BUT PLENTY OF DETAIL DIFFERENCES REMAIN WITH THE WEAKER SHORTWAVES THRU THE SOUTHWEST FLOW OVER THE CENTRAL CONUS. GENERAL TREND IS A LITTLE FLATTER WITH THE CENTRAL CONUS RIDGING AND STRONGER WITH UNIDENTIFIABLE SHORTWAVE FEATURES. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED ALL TO BE REASONABLE WITH THE SFC MASS FIELDS OVER THE CENTRAL CONUS. PER WV IMAGERY MODELS LOOKED GOOD WITH THE LARGER SHORTWAVES OVER NOAM...WHILE STRUGGLING WITH WHAT LOOKED TO BE A WEAK SHORTWAVE AIDING THE NEB/CO/KS CONVECTION. AS HAS BEEN THE CASE THE PAST FEW DAYS...MODELS HAVING DIFFICULTIES WITH CONVECTION OVER THE CENTRAL CONUS. CLOSEST WITH THE 00-06Z PRECIP LOOKED TO BE THE GFS AND THE HRRR WRF MODEL. NO ONE CLEAR FAVORITE. WITH ALL THE MODEL SCENARIOS ON HOW CONVECTION PLAYS OUT THE NEXT 48-72HRS AND MOST MODELS CONTINUING TO STRUGGLE WITH THAT EARLY THIS MORNING...SHORT-TERM CONFIDENCE REMAINS BELOW AVERAGE. FORECAST TODAY/TONIGHT HINGES ON WHERE THE KS/NORTHERN MO BOUNDARY ENDS UP. MODEL CONSENSUS LIFTS THIS BOUNDARY...AND ITS FOCUS FOR FORCING/LIFT/CONVECTION INITIATION...SLOWLY NORTH TODAY/TONIGHT... TO SOUTHWEST MN TO EASTERN IA/NORTHWEST IL BY 12Z TUE. MOISTURE TRANSPORT/THETA-E CONVERGENCE ON NOSE OF THE 850MB JET ALREADY FIRING THE CONVECTION OVER IA...WITH THIS TRANSLATING EAST/NORTHEAST TOWARD AND INTO THE SOUTHEAST END OF THE FCST AREA. WILL EXTEND THE FLASH FLOOD WATCH FOR THE SOUTHEAST END OF THE FCST AREA THRU THE MORNING. LOW LEVEL MOISTURE TRANSPORT/THETA-E CONVERGENCE CONTINUES TO INCREASE OVER THE FRONT AND TOWARD THE AREA TODAY AS LOW PRESSURE LIFTS INTO NEB. GENERAL MODEL CONSENSUS FOR CONVECTION TO SLOWLY BUILD WEST/SOUTH OF THE FCST AREA THIS MORNING THE LIFT INTO THE AREA THIS AFTERNOON. PER THE HRRR...PART OF THIS IS THE COMPLEX MOVING ACROSS NEB EARLY THIS MORNING. LEANING TOWARD THE HRRR WHICH HAS BEEN DOING A DECENT JOB WITH THE CO/NEB CONVECTION AND THAT ACROSS IA...THE NEB CONVECTION GROWS ONCE IT REACHES STRONGER/RICHER MOISTURE TRANSPORT OVER EASTERN NEB/WESTERN IA. SOME FORM OF CONVECTIVE COMPLEX THEN HEADS TOWARD THE FCST AREA FOR THE AFTERNOON. LOW LEVEL THERMODYNAMIC FORCING STRENGTHENS INTO THE AREA TONIGHT ALONG WITH THE MOISTURE TRANSPORT AS THE FRONT SLOWLY LIFTS NORTH. RAISED SHRA/TSRA CHANCES INTO THE 60-70 PERCENT RANGE FOR TONIGHT INTO TUE MORNING. ANY TSRA WILL REMAIN EFFICIENT RAIN MAKERS WITH PW VALUES IN THE 1.5 TO 1.75 INCH RANGE...ML CAPES OF 2K-3K J/KG AND WARM CLOUD DEPTHS OF 3.5 TO 4KM. WITH MANY AREAS WATERLOGGED AND HAVING ONGOING FLOODING ISSUES...WILL EXPAND THE FLASH FLOOD WATCH TO COVER ALL BUT CLARK/TAYLOR COUNTIES FOR THIS AFTERNOON THRU MID MORNING TUE. FORCING SIGNALS GET A LITTLE MORE MUDDIED TUE. THIS NOT UNEXPECTED DUE TO POTENTIAL DIFFERENT OUTCOMES WITH CONVECTION OVER THE UPPER MIDWEST TONIGHT. APPEARS THE FRONT WILL REMAIN SOUTH OF THE FCST AREA WITH THE 925-850MB FLOW CONTINUING TO PUSH/LIFT MOISTURE NORTHWARD OVER IT. CONTINUED 40-60 PERCENT SHRA/TSRA CHANCES OVER MUCH OF THE FCST AREA TUE. MAY NEED TO EXTEND THE FLASH FLOOD WATCH THRU TUE INTO TUE NIGHT...BUT WILL DEAL WITH THAT ONCE WE GET PAST TONIGHT. ON TOP OF THE HEAVY RAIN CONCERNS...A FEW OF THE TSRA COULD BE SEVERE THIS AFTERNOON/EVENING AND AGAIN TUE INTO TUE EVENING DUE TO THE STRONG INSTABILITY...INCREASE OF THE 0-6KM SHEAR AND POTENTIAL FOR TSRA TO ORGANIZE INTO COMPLEXES WITH STRONG COLD POOLS. SEE SWODY1 AND SWODY2 FOR MORE DETAILS. USED A BLEND OF THE NUMERICAL TEMP GUIDANCE FOR HIGHS/LOWS FOR TODAY THRU TUE. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 415 AM CDT MON JUN 24 2013 FOR TUE NIGHT THRU WED NIGHT MODELS SHOW THE REMNANTS OF THE TROUGHING NOW OVER CA WILL LIFT INTO AND ACROSS THE UPPER MIDWEST. TREND CONTINUES TO FAVOR STRONGER OF THE EARLIER RUNS. WITH THIS BEING A LARGER SCALE FEATURE AND THE DECENT MODEL CONSISTENCY FCST CONFIDENCE FOR THIS PERIOD IS AVERAGE. AS THE STRONGER MID LEVEL TROUGH MOVES INTO THE UPPER MIDWEST TUE NIGHT THE PLAINS SFC LOW MOVES INTO MN/WI. LOWER LEVEL THERMO DYNAMIC FORCING/LIFT AND MOISTURE TRANSPORT REMAINS STRONG INTO THE AREA AHEAD OF THESE FEATURES. WHERE THE FRONT AHEAD OF THE LOW FROM TODAY/TUE ENDS UP WILL DETERMINE WHERE THE STRONGER LIFT WILL BE. MODEL CONSENSUS HAS IT SOMEWHERE OVER THE FCST AREA TUE NIGHT... THUS CARRIED HIGHEST SHRA/TSRA CHANCES IN THE 60-70 PERCENT RANGE OVER THE NORTHEAST 2/3 OF THE FCST AREA. PW VALUES REMAIN IN THE 1.5 TO 1.75 INCH RANGE WITH ANY STORMS CAPABLE OF PRODUCING HEAVY RAINS. AGAIN...WILL LIKELY NEED MORE FLASH FLOOD WATCHES FOR PORTIONS OF THE AREA INTO TUE NIGHT WITH POTENTIAL FOR ANOTHER 0.5 TO 1.5 INCHES...LOCALLY MORE...OF RAIN. ONCE THIS STRONGER MID LEVEL TROUGH PASSES TUE NIGHT/WED MORNING THE FLOW PATTERN OVER NOAM BEGINS TO CHANGE WITH RIDGING BUILDING OVER THE WESTERN CONUS AND INCREASING NORTHWEST FLOW ALOFT OVER THE UPPER MIDWEST. DRIER AIR AND HIGH PRESSURE WILL SLOWLY SPREAD INTO MN/IA/WI WED/WED NIGHT. SHRA/TSRA CHANCES WILL LINGER WED WITH THE SFC LOW-MID LEVEL TROUGH OVER THE REGION. SHRA/TSRA CHANCES DECREASE WED NIGHT AS HGTS RISE AND THE SFC-MID LEVEL LOW/TROUGH MOVE EAST OF THE AREA. DUE TO THE CONVECTION DETAIL UNCERTAINTIES...CONTINUED TO USE THE MODEL/ENSEMBLE CONSENSUS FOR LOWS/HIGHS IN THE TUE NIGHT TO WED NIGHT PERIOD. ONCE AGAIN NOT A LOT OF TIME SPENT LOOKING AT THE DAY 4-7 PERIOD. 24.00Z MEDIUM RANGE MODELS MAINTAIN A GOOD CONSENSUS FOR THE BUILDING WESTERN NOAM RIDGING AND EASTERN NOAM TROUGHING IN THE THU- SUN PERIOD...WHICH PUTS THE REGION UNDER INCREASING NORTHWEST FLOW ALOFT. THU-SUN SHAPING UP TO BE A DRIER PERIOD WITH TEMPERATURES COOLING TO NEAR OR A BIT BELOW NORMAL. FCST CONFIDENCE FOR THIS PERIOD LOOKS TO BE AVERAGE TO GOOD. DRIER HIGH PRESSURE BUILDS IN FOR THU-SUN...BUT PLENTY OF RESIDUAL LOW LEVEL MOISTURE AND MAXIMUM EVAPO-TRANSPIRATION FROM WELL WATERED VEGETATION AND WET SOILS APPEAR TO REMAIN...ALONG WITH STEEP LOW/ MID LEVEL LAPSE RATES AND SHORTWAVES RIPPLING THRU THE NORTHWEST FLOW ALOFT. THU-SUN TRENDING TO BE DRY DAYS BUT SOME SMALLER MAINLY DIURNAL SHRA/TSRA CHANCES TO PERSIST...AIDED BY THE PASSING SHORTWAVES FROM TIME TO TIME. MODEL/ENSEMBLE CONSENSUS FOR HIGHS/ LOWS IN THE DAY 4-7 PERIOD LOOK WELL TRENDED FOR NOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1141 PM CDT SUN JUN 23 2013 WATCHING A LINE OF CONVECTION ACROSS SOUTHERN IOWA THIS EVENING WITH THE CONCERN OF WHETHER THIS WILL MOVE NORTHEAST INTO THE AREA. THE 24.02Z HRRR AND ITS PREVIOUS RUNS HAVE BEEN DOING A DECENT JOB HANDLING THIS FEATURE AND ATTEMPTS TO BRING IT NORTHEAST BUT WEAKEN IT WITH TIME. RECENT RADAR TRENDS SUGGEST ONLY A VERY SLOW NORTHEAST MOVEMENT WHILE THE CORFIDI VECTORS WOULD SUGGEST A MORE EASTWARD MOVEMENT. FOR NOW...PLAN TO CONTINUE WITH A DRY FORECAST AND ONLY SHOW SOME VFR CLOUDS FROM THIS SYSTEM GETTING INTO THE AREA. VARIOUS SOLUTIONS ON HOW MONDAY PLAYS OUT. WITH THE MAIN BOUNDARY NOW WELL SOUTH OF THE AREA...SEVERAL MODELS INDICATING THE NEXT ROUND OF CONVECTION SHOULD DEVELOP AGAIN OVER SOUTHERN IOWA AND REMAIN TO THE SOUTH OF THE AREA. MODELS ALSO SHOW DIFFERENT IDEAS WITH THE ONGOING CONVECTION OVER COLORADO. THE 23.12Z GEM AND ECMWF BRING THIS NORTHEAST AND EAST INTO THE AREA WITH THE MEAN FLOW WHILE THE HRRR TAKES IT MORE EAST ACROSS NEBRASKA AND KANSAS RIDING THE CAPE GRADIENT WHILE FEEDING OFF THE LOW LEVEL MOISTURE FIELD. WOULD TEND TO THINK THE HRRR IDEA HAS A HIGHER PROBABILITY OF VERIFYING...BUT THERE IS A SHORT WAVE TROUGH DRIVING THIS SYSTEM THAT SHOULD GET INTO THE AREA LATE MONDAY AFTERNOON OR EVENING. WITH THE FORCING FROM THAT...CANNOT TOTALLY RULE OUT SOME CONVECTION DEVELOPING BUT WITH LOW CONFIDENCE HAVE ONLY INCLUDED A VCTS AT THIS TIME. && .HYDROLOGY... ISSUED AT 415 AM CDT MON JUN 24 2013 THE THREAT FOR HEAVY RAINS CONTINUES/RETURNS TODAY AS YET ANOTHER LOW LIFTS INTO THE CENTRAL PLAINS AND MOISTURE TRANSPORT INCREASES INTO THE AREA. A FRONT SLOWLY LIFTING NORTH FROM KS/NORTHERN MO WILL BE THE FOCUS FOR LIFT AND GENERATING TSRA TODAY/TONIGHT/TUE. THIS BOUNDARY EXPECTED TO REMAIN SOUTH OF THE AREA THRU TUE...WITH THE ZONE OF STRONGER LIFT REMAINING CLOSE TO OR OVER THE FCST AREA. THUNDERSTORMS WILL CONTINUE TO BE EFFICIENT RAIN PRODUCERS. RAINFALL AMOUNTS THIS AFTERNOON AND TONIGHT COULD RANGE FROM 0.50 TO 1.50 INCHES...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. SINCE MUCH OF THE AREA HAS SEEN ANYWHERE FROM 2 TO 10 INCHES DURING THE LAST 3 TO 4 DAYS...IT WILL NOT TAKE MUCH RAIN TO PRODUCE MORE FLOODING PROBLEMS. ADDITION FLASH FLOODING IS QUITE POSSIBLE ACROSS PARTS OF THE FORECAST AREA TODAY THRU TUE NIGHT. HOWEVER THERE CONTINUES TO BE MUCH UNCERTAINTY ON WHERE THIS RAIN MAY FALL. CONTINUED THE FLASH FLOOD WATCH FOR THE SOUTHEAST END OF THE FCST AREA THIS MORNING THEN ISSUED A BROADER FLASH FLOOD WATCH FOR ALL BUT CLARK/TAYLOR COUNTIES THIS AFTERNOON THROUGH MID MORNING TUE. APPEARS ANOTHER ROUND OF WIDESPREAD CONVECTION IS POSSIBLE TUE NIGHT/WED MORNING AND ADDITIONAL FLASH FLOOD WATCHES ARE LIKELY FOR THOSE PERIODS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING FOR WIZ032>034-041>044-053. FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ054-055-061. MN...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING FOR MNZ079-086>088-094>096. IA...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING FOR IAZ008>010-018-019. FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR IAZ011-029-030. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION.....04 HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1141 PM CDT SUN JUN 23 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 344 PM CDT SUN JUN 23 2013 AT 3 PM...A LINE OF SHOWERS AND THUNDERSTORMS WAS MOVING ACROSS NORTHERN ILLINOIS. MEANWHILE THERE WAS ANOTHER CONVERGENT BOUNDARY ALONG THE MISSISSIPPI RIVER. BOTH THE 23.12Z ARW AND NMM DEVELOP A LINE OF THE SHOWERS AND THUNDERSTORMS ALONG THE LATTER BOUNDARY BETWEEN 23.21Z AND 24.00Z. HOWEVER THEY ALSO HAVE AROUND 3000 J/KG OF SURFACE BASED CAPE AND THE SPC SURFACE BASED CAPE IS CURRENTLY ONLY AROUND 500 J/KG...SO THINKING THAT THE AREA WILL REMAIN DRY FOR LATE THIS AFTERNOON LIKE THE LAST 3 HOURLY RUNS OF THE HRRR HAVE BEEN SHOWING. FOR THIS EVENING...THE 23.12Z MESO /RAP...NMM...AND ARW/ AND DETERMINISTIC MODELS SUGGEST THAT THE COMBINATION OF MODERATE 850 MB MOISTURE TRANSPORT AND 2 TO 3K MOST UNSTABLE CAPES WILL RESULT IN THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS NORTHEAST IOWA...AND CENTRAL AND SOUTHWEST WISCONSIN. THE HRRR WAS SUGGESTING A SIMILAR SCENARIO EARLIER THIS MORNING AND HAS SINCE BACKED AWAY FROM THIS SOLUTION. WITH THERE BEING SUCH AGREEMENT IN THE MODELS OPTED TO KEEP A 20 TO 60 PERCENT CHANCE GOING FOR THIS AREA TONIGHT. WITH LITTLE OR NO PRECIPITATION EXPECTED ELSEWHERE ACROSS THE FORECAST AREA...WILL DROP THE FLASH FLOOD WATCH ACROSS SOUTHEAST MINNESOTA AND PARTS OF WEST CENTRAL WISCONSIN. FOR OVERNIGHT...BOTH THE ECMWF AND NOW THE HRRR SHOW THAT A SHORT WAVE CURRENTLY OVER THE TEXAS PANHANDLE WILL MOVE NORTHEAST INTO NORTHEAST IOWA AND SOUTHWEST WISCONSIN. THE HRRR SHOWS AN AREA OF SHOWERS AND THUNDERSTORMS SURGING NORTHWARD TOWARD THE FORECAST AREA AFTER 07Z. DUE TO THIS KEPT...THE PRECIPITATION CHANCES IN THE 20 TO 60 PERCENT RANGE. WITH PRECIPITABLE WATER VALUES AROUND 1.8 INCHES AND WARM CLOUD LAYER DEPTHS UP 4.5 KM...THESE THUNDERSTORMS WILL BE VERY EFFICIENT RAIN PRODUCERS...THUS...KEPT THE FLASH FLOOD WATCH UP NORTHEAST IOWA AND SOUTHWEST AND CENTRAL WISCONSIN. THE ONLY QUESTION IN THE FORECAST IS WHETHER WE HAVE THE PRECIPITATION CHANCES DECREASING TOO FAST TOWARD SUNRISE. ON MONDAY...THERE IS UNCERTAINTY ON HOW LONG THE SHORT WAVE WILL LINGER ACROSS SOUTHWEST WISCONSIN AND NORTHEAST IOWA. WITH MANY OF THE MESO MODELS DRY FOR THE MORNING...DECIDED TO TREND THE PRECIPITATION CHANCES TOWARD THE DRY SIDE. DURING THE AFTERNOON...THERE IS UNCERTAINTY ON HOW FAST THE 850 MB MOISTURE TRANSPORT WILL DEVELOP ACROSS THE AREA. THE NAM HAS IT DEVELOPING DURING THE LATE AFTERNOON AND MANY OF THE OTHER MODELS SUGGEST THAT IT MIGHT OCCUR ON MONDAY NIGHT. WITH THERE BEING VERY LITTLE CONSISTENCY IN THE MODELS OVER THE PAST SEVERAL DAYS...DECIDED TO COMPROMISE WITH 30 TO 40 PERCENT PRECIPITATION PROBABILITIES. LIKE OVER THE WEEKEND...THE 0-6 KM SHEAR REMAINS LESS THAN 40 KNOTS. HOWEVER THE 0-3KM CONTINUES ABOVE 30 KNOTS...THUS COULD SEE THE POTENTIAL FOR SOME BOWING SEGMENTS AS THE THUNDERSTORMS BECOME COLD POOL DOMINANT. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 344 PM CDT SUN JUN 23 2013 ON MONDAY NIGHT...THE MODELS CONTINUE TO SHOW THAT A MESOSCALE CONVECTIVE COMPLEX WILL DEVELOP JUST WEST OF THE FORECAST AREA AND THEN MOVE THROUGH THE FORECAST AREA DURING THE NIGHT. WITH STRONG 850 MB MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE REGION... PRECIPITABLE WATER VALUES RUNNING AROUND 2 INCHES...AND WARM CLOUD DEPTHS EXCEEDING 4 KM...EXPECT AN AREA OF HEAVY RAIN /POTENTIALLY 3 TO 5 INCHES/ TO FALL ACROSS PARTS OF THE FORECAST AREA. MANY OF THE MODELS ARE SUGGESTING ALONG AND NORTH OF THE INTERSTATE 90 CORRIDOR. HOWEVER WITH THE MODELS BEING A BIT TOO FAR NORTH LATELY...THERE IS A POSSIBILITY THAT THE HEAVIEST PRECIPITATION MAY FALL ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN. WILL LIKELY HAVE TO ISSUE ANOTHER FLASH FLOOD WATCH FOR THIS TIME PERIOD EITHER LATE TONIGHT OR ON MONDAY. FROM TUESDAY AFTERNOON INTO TUESDAY NIGHT...THE MODELS SHOW YET ANOTHER MESOSCALE CONVECTIVE COMPLEX MOVING THROUGH THE REGION. WITH THE MODELS CONTINUING TO SHOW STRONG 850 MB MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE REGION... PRECIPITABLE WATER VALUES RUNNING AROUND 2 INCHES...AND WARM CLOUD DEPTHS EXCEEDING 4 KM...EXPECT AN AREA OF HEAVY RAIN /POTENTIALLY ANOTHER 3 TO 5 INCHES/ TO FALL ACROSS PARTS OF THE FORECAST AREA. AT THIS TIME... IT LOOKS LIKE THE HEAVIEST RAIN WOULD FALL ALONG AND SOUTH OF THE INTERSTATE 90 CORRIDOR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1141 PM CDT SUN JUN 23 2013 WATCHING A LINE OF CONVECTION ACROSS SOUTHERN IOWA THIS EVENING WITH THE CONCERN OF WHETHER THIS WILL MOVE NORTHEAST INTO THE AREA. THE 24.02Z HRRR AND ITS PREVIOUS RUNS HAVE BEEN DOING A DECENT JOB HANDLING THIS FEATURE AND ATTEMPTS TO BRING IT NORTHEAST BUT WEAKEN IT WITH TIME. RECENT RADAR TRENDS SUGGEST ONLY A VERY SLOW NORTHEAST MOVEMENT WHILE THE CORFIDI VECTORS WOULD SUGGEST A MORE EASTWARD MOVEMENT. FOR NOW...PLAN TO CONTINUE WITH A DRY FORECAST AND ONLY SHOW SOME VFR CLOUDS FROM THIS SYSTEM GETTING INTO THE AREA. VARIOUS SOLUTIONS ON HOW MONDAY PLAYS OUT. WITH THE MAIN BOUNDARY NOW WELL SOUTH OF THE AREA...SEVERAL MODELS INDICATING THE NEXT ROUND OF CONVECTION SHOULD DEVELOP AGAIN OVER SOUTHERN IOWA AND REMAIN TO THE SOUTH OF THE AREA. MODELS ALSO SHOW DIFFERENT IDEAS WITH THE ONGOING CONVECTION OVER COLORADO. THE 23.12Z GEM AND ECMWF BRING THIS NORTHEAST AND EAST INTO THE AREA WITH THE MEAN FLOW WHILE THE HRRR TAKES IT MORE EAST ACROSS NEBRASKA AND KANSAS RIDING THE CAPE GRADIENT WHILE FEEDING OFF THE LOW LEVEL MOISTURE FIELD. WOULD TEND TO THINK THE HRRR IDEA HAS A HIGHER PROBABILITY OF VERIFYING...BUT THERE IS A SHORT WAVE TROUGH DRIVING THIS SYSTEM THAT SHOULD GET INTO THE AREA LATE MONDAY AFTERNOON OR EVENING. WITH THE FORCING FROM THAT...CANNOT TOTALLY RULE OUT SOME CONVECTION DEVELOPING BUT WITH LOW CONFIDENCE HAVE ONLY INCLUDED A VCTS AT THIS TIME. && .HYDROLOGY... ISSUED AT 344 PM CDT SUN JUN 23 2013 WITH SLIGHTLY DRIER AIR MOVING INTO SOUTHEAST MINNESOTA AND WEST- CENTRAL WISCONSIN THIS AFTERNOON...THE THREAT FOR HEAVY RAIN HAS GREATLY DIMINISHED ACROSS MUCH OF SOUTHEAST MINNESOTA AND PARTS OF WEST CENTRAL WISCONSIN. AS A RESULT...DROPPED THE FLASH FLOOD WATCH IN THESE AREAS. MEANWHILE IN SOUTHWEST AND CENTRAL WISCONSIN AND NORTHEAST IOWA...THERE WILL BE THE POTENTIAL FOR THE DEVELOPMENT OF THUNDERSTORMS ACROSS THESE AREAS FROM LATE EVENING INTO THE OVERNIGHT. CONDITIONS CONTINUE TO BE FAVORABLE FOR THE THUNDERSTORMS TO EFFICIENT RAIN PRODUCERS. RAINFALL AMOUNTS TONIGHT COULD RANGE FROM 0.50 TO 1.50 INCHES. SINCE THESE AREAS HAVE SEEN ANYWHERE FROM 6 TO 10 INCHES DURING THE LAST 3 DAYS...IT WILL NOT TAKE MUCH WATER TO PRODUCE FLASH FLOODING. ADDITION FLASH FLOODING LOOKS LIKELY ACROSS PARTS OF THE FORECAST AREA ON MONDAY NIGHT AND FROM TUESDAY AFTERNOON INTO TUESDAY NIGHT. EACH OF THESE EVENTS COULD PRODUCE 3 TO 5 INCHES OF RAIN ACROSS THE AREA. HOWEVER THERE CONTINUES TO BE MUCH UNCERTAINTY ON WHERE THIS RAIN MAY FALL. EXPECT ADDITIONAL FLASH FLOOD WATCHES TO BE ISSUED FOR THESE TIME PERIODS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR WIZ041>044-053>055- 061. MN...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR MNZ096. IA...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR IAZ008>011-018-019- 029-030. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...04 HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1133 PM CDT SUN JUN 23 2013 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .UPDATE... ISSUED AT 943 PM CDT SUN JUN 23 2013 HAVE REMOVED PCPN CHANCES FOR THE REST OF TONIGHT. DAYTIME INSTABILITY HAS WANED AND CONVERGENCE ALONG THE BOUNDARY THAT BISECTS THE CWA FROM NE TO SW (SEE DEW POINT GRADIENT) HAS WEAKENED. 850 MB FLOW IS EXPECTED TO CONTINUE TO VEER WEST OVERNIGHT...WHICH WILL BRING DRIER AIR INTO THE REGION. PRECIPITABLE WATER ON THE MPX RAOB DROPPED FROM 1.72 INCH AT 12Z TO 0.77 INCH AT 00Z. DISTURBANCE OVER NORTHEAST COLORADO IS EXPECTED TO LIFT NE TOWARD WI BY MONDAY EVENING. THE LLJ IS ALSO EXPECTED TO BACK SW AND INCREASE UPSTREAM OF THE REGION...SO PCPN CHANCES SHOULD INCREASE AGAIN TOMORROW NIGHT. && .SHORT TERM...TONIGHT AND MONDAY ISSUED AT 252 PM CDT SUN JUN 23 2013 THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE WARM FRONT HAS MOVED THROUGH MOST OF WISCONSIN EXCEPT FOR FAR NORTHEAST WISCONSIN EARLY THIS AFTERNOON. SOME REMNANT STORMS FROM AN EARLIER LINE OF CONVECTION ARE MOVING ACROSS SOUTHERN WISCONSIN...BUT STARTING TO SEE SIGNS OF BEEFY CU DEVELOPING FARTHER NORTH FROM WAUSHARA COUNTY TO THE WESTERN UPPER PENINSULA. THIS IS IN A REGION OF BUILDING ML CAPES FROM 1000-1400 J/KG. STILL PLENTY OF TIME FOR FURTHER DESTABILIZATION TO OCCUR...WITH LIFT VIA SHORTWAVE OVER NORTHWEST WISCONSIN. AM STILL EXPECTING STORMS TO FIRE THOUGH IT MAY STILL HAVE A COUPLE HOURS TO GO. ACTUAL FRONT LIES ACROSS EASTERN MINNESOTA AND CLEARING SKIES ARE MOVING INTO SOUTHWEST MINNESOTA. IMPACTS FROM CONVECTION ARE THE MAIN FORECAST CONCERN IN THE SHORT TERM. TONIGHT..SHORTWAVE OVER NORTHWEST WISCONSIN WILL LIFT NORTHEAST AND CLEAR NORTHEAST WISCONSIN IN THE EVENING. FORCING ALONG THE TAIL OF THIS VORT AND FURTHER DESTABILIZATION SHOULD ALLOW SCT STORMS TO MOVE ACROSS NORTHEAST WISCONSIN IN THE EVENING. WINDS AT 700MB ARE PRETTY STRONG AT 45 TO 50 KTS...SO ANY STORMS WILL HAVE POTENTIAL AT CREATING DAMAGING WIND GUSTS AND SMALL HAIL. LOSS OF HEATING AND EXITING OF THE TAIL OF THE VORT SHOULD LET THE CONVECTION DIMINISH AND/OR EXIT BY MID TO LATE EVENING. ACTUAL SURFACE FRONT WILL DROP INTO NORTH-CENTRAL WISCONSIN AFTER MIDNIGHT. CONVERGENCE ALONG THE FRONT IS VERY WEAK AND THERE IS NO SUPPORT ALOFT...SO COULD SEE SOME LOW CLOUDS ALONG THE FRONT...MUCH NOT MUCH ELSE. WILL END POPS FROM NW TO SE AFTER MIDNIGHT. MUGGY LOWS IN THE MID TO UPPER 60S. MONDAY...SURFACE FRONT WILL STALL ACROSS NORTHERN WISCONSIN IN THE MORNING. PROGGED SOUNDINGS AND UPSTREAM SATELLITE IMAGERY SHOW PLENTY OF DRY AIR THROUGH THE COLUMN AND PARTLY TO MOSTLY CLEAR SKIES. NO CLEAR TRIGGERS UPSTREAM EITHER SO WILL GO WITH A DRY BUT PARTLY CLOUDY START TO THE DAY. COME AFTERNOON...AN 86/69 PARCEL OVER THE FOX VALLEY WILL RESULT IN 3000 J/KG OF ML CAPE AND VERY LITTLE CIN. CONVECTIVE TEMPS ARE IN THE LOW 90S AND DO NOT SEE A TRIGGER...BUT PERHAPS THE LAKE BREEZE CAN CREATE THE NECESSARY CONVERGENCE FOR A STORM OR TWO TO POP. WILL KEEP A SLIGHT CHANCE OF A STORM OVER CENTRAL AND NORTHEAST WISCONSIN WHERE INSTABILITY IS MAXIMIZED. HIGHS MAINLY IN THE MID 80S. .LONG TERM...MONDAY NIGHT THROUGH SUNDAY ISSUED AT 252 PM CDT SUN JUN 23 2013 MEDIUM RANGE MODELS ARE IN GREATER DISAGREEMENT THAN THE LAST FEW DAYS...ESPECIALLY WITH A POSSIBLE CONVECTIVE COMPLEX LATE MONDAY NIGHT OR TUESDAY AND AGAIN WEDNESDAY NIGHT WITH THE POSSIBLE FORMATION OF A CLOSED LOW OVER WISCONSIN OR UPPER MICHIGAN. AS FAR AS LATE MONDAY NIGHT AND TUESDAY GOES IT LOOKS LIKE THE GFS IS EXHIBITING SOME SORT OF CONVECTIVE FEEDBACK PRODUCING A CLOSED UPPER LOW THAT MOVES ACROSS MINNESOTA AND WISCONSIN PRODUCING CONSIDERABLE CONVECTION. THIS IS LIKELY OVERDONE AND PREFER THE FLATTER AND SLOWER UPPER SYSTEM THAT SHOULD BRING SHOWERS AND THUNDERSTORMS TUESDAY AFTERNOON AND EVENING. THE GFS ALSO FORECASTS A CLOSED UPPER LOW WEDNESDAY NIGHT AND THURSDAY OVER THE WESTERN GREAT LAKES WHICH SEEMS OVERDONE CONSIDERING THE CURRENT PATTERN. CANNOT TOTALLY DISCOUNT THE GFS AS IT HAS SOME SUPPORT FROM THE NAM BUT THE ECMWF IS MUCH FASTER AND WEAKER. WARM AND HUMID WEATHER EXPECTED THROUGH THURSDAY. AFTER THURSDAY THE MODELS DO AGREE THAT AN UPPER RIDGE WILL DEVELOP OVER THE WESTERN UNITED STATES WITH CYCLONIC NORTHWEST FLOW OVER WISCONSIN. THIS SHOULD BRING COOLER AND DRIER AIR TO THE REGION BY FRIDAY AND SATURDAY. WHILE IT SHOULD BE GENERALLY DRY FRIDAY AND SATURDAY THERE COULD BE SCATTERED DIURNAL SHOWERS WITH COLD TEMPERATURES ALOFT. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1122 PM CDT SUN JUN 23 2013 GETTING A HANDLE ON PCPN TRENDS HAS BEEN A TOUGH TASK OVER THE PAST FEW DAYS...SO OVERALL CONFIDENCE REMAINS LOW. REGARDLESS... CURRENT INDICATIONS ARE THAT THE REST OF TONIGHT AND MUCH OF MONDAY SHOULD BE DRY. SOME DRIER AIR WILL CONTINUE TO OVERSPREAD NORTHERN WI TONIGHT...AND REMAIN IN PLACE ON MONDAY. WILL STILL NEED TO MONITOR FOR POSSIBLE CONVECTIVE DEVELOPMENT ALONG ANY WEAK BOUNDARIES DURING THE AFTERNOON...BUT CONFIDENCE IS TOO LOW TO MENTION IN THE TAFS. BEST ESTIMATE RIGHT NOW IS THAT SOME CONVECTION WILL FIRE MONDAY NIGHT...AS A WEAK UPPER DISTURBANCE TRACKS THROUGH THE AREA AND A SOUTHWESTERLY LOW-LEVEL JET REDEVELOPS. THERE IS SOME POTENTIAL FOR FOG LATE TONIGHT...ALTHOUGH WILL ONLY MENTION MVFR VSBYS...EXCEPT AT RHI WHERE SOME IFR CONDITIONS MAY OCCUR. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE.........KIECKBUSCH SHORT TERM.....MPC LONG TERM......RDM AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS ALBANY NY
1003 AM EDT MON JUN 24 2013 .SYNOPSIS... VERY WARM AND HUMID CONDITIONS WILL CONTINUE EARLY THIS WEEK WITH THE THREAT OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EVENING HOURS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL. OUR NIGHTS WILL BE CONTINUE TO BE MUGGY WITH PATCHY FOG. MORE PERSISTENT CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED LATER IN THE WEEK INTO THE WEEKEND AS A SLOW MOVING LOW PRESSURE SYSTEM IMPACTS THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 955 AM...ANOTHER HAZY...HOT AND HUMID DAY SHAPING UP. 12Z ALY SOUNDING SHOWS PLENTY OF ENERGY FOR AFTERNOON THUNDERSTORMS. WATER VAPOR LOOP SHOWS CLOSED LOW SPINNING OVER WESTERN PENNSYLVANIA. THIS UPPER LEVEL LOW IS EXPECTED TO MOVE OVER THE SOUTHERN PART OF THE ALBANY FORECAST AREA OVER THE NEXT 12-18 HOURS AND SHOULD BE A FOCUS FOR STORMS. PWAT ON 12Z ALY SOUNDING WAS 1.77 INCHES SO COPIOUS MOISTURE FOR HEAVY RAINERS. PIT 12Z SOUNDING...UNDER UPPER LEVEL LOW...HAS STEEPER LAPSE RATES. 12Z HRRR SHOWING A MORE WIDESPREAD THREAT OF AFTERNOON STORMS. WILL HAVE TO MONITOR FOR LATER FLASH FLOOD WATCH IF LARGE AREA OF HEAVY RAIN DEVELOPS. COULD BE AN EXCITING DAY... PREVIOUS... THE RIDGE WILL WEAKEN A TAD TODAY AS THE REMNANTS OF THE UPPER LOW FROM OVER THE TENNESSEE VALLEY MOVES EASTWARD. THIS WILL BE THE MAIN FEATURE TRIGGERING CONVECTION ACROSS THE AREA TODAY AND IT WILL ACCOMPANY THE HEATING OF THE DAY. MODEL GUIDANCE SUGGESTS CAPE VALUES OF PEAKING AT 1000-2000 J/KG WITH DEW POINTS IN THE MID TO UPPER 60S. LAPSE RATE OF 6 TO 6.5 C/KM ARE EXPECTED THIS AFTERNOON WITH THE GFS INDICATING 7 C/KM POSSIBLE. MEAN FLOW IS RATHER WEAK AT 15 TO 20 KNOTS SO STORMS WILL MOVE RATHER SLOWLY AND CONVECTION WILL BE LOOSELY ORGANIZED. THE STORM PREDICTION CENTER HAS THE AREA/REGION IN THE GENERAL THUNDERSTORM OUTLOOK FOR TODAY AND TONIGHT. FREEZING LEVEL IS HIGH JUST OVER 14000 FEET ON THE 00Z/MON ALY SOUNDING...SO SOME STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL. THIS ALONG WITH THE RATHER SLOW MOVEMENT HAVE ADDED ENHANCED WORDING OF HEAVY RAINFALL TO THE FORECAST AND WILL KEEP MENTION IN THE HAZARDOUS WEATHER OUTLOOK. CONVECTION IS EXPECTED TO DIMINISH THIS EVENING AS THE WEAKENING UPPER LOW/TROUGH MOVES OFF TO THE EAST AND WITH THE LOSS OF DAYTIME HEATING. LOOKING AT TEMPERATURES IN THE 80S WITH AROUND 90 DEGREES UP THE HUDSON VALLEY INTO CAPITAL DISTRICT. DEW POINTS WILL BE IN THE MID TO UPPER 60S MAKING IT FELL EVEN HOTTER. HEAT INDICES SHOULD REACH THE MID 90S UP THE HUDSON RIVER VALLEY. ANOTHER MUGGY NIGHT WITH LOWS AND DEW POINTS IN THE 60S. WINDS WILL BECOME LIGHT TO CALM WINDS. HAVE ADDED PATCHY FOG MAINLY IN THE RIVER VALLEY LOCATIONS. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... BY TUESDAY MORNING FLOW WILL BECOME NEARLY ZONAL ACROSS THE REGION. A WEAKENING SURFACE LOW AND MID LEVEL SHORT WAVE TROUGH WILL MOVE EASTWARD ACROSS SOUTHERN CANADA PASSING WELL TO OUR NORTH TUESDAY. PLUS GUIDANCE INDICATES SMALL PIECES OF ENERGY SHOULD MOVE THROUGH THE FLOW FARTHER SOUTH ACROSS OUR REGION.ALL THIS LEADS TO ANOTHER ROUND OF CONVECTION MAINLY DURING THE AFTERNOON AND EVENING HOURS TUESDAY WITH THE HEATING OF THE DAY. THE BETTER DYNAMICS AND SHEAR WILL BE ACROSS NORTHERN NEW YORK INTO NORTHERN NEW ENGLAND AND THIS IS WHERE THE STORM PREDICTION CENTER HAS GONE WITH A SLIGHT RISK FOR SEVERE THUNDERSTORMS. FARTHER SOUTH ACROSS OUR FORECAST AREA MEAN FLOW WILL STILL BE RATHER WEAK AROUND 20 KNOTS. IT WILL BE ANOTHER HOT DAY SIMILAR TO MONDAY IN TEMPERATURES AND HEAT INDICES. A WEAK FRONTAL BOUNDARY WILL BE BROUGHT SOUTHWARD INTO THE REGION TUESDAY NIGHT...HOWEVER DUE TO THE FLOW ALOFT THE BOUNDARY WILL STALL ACROSS THE REGION. A MORE VIGOROUS SHORT WAVE WILL MOVE INTO THE LONGWAVE TROUGH OVER THE GREAT LAKES REGION WEDNESDAY AND WEDNESDAY NIGHT AND HEIGHTS WILL BEGIN TO FALL. CHANCES FOR CONVECTION WILL NOT BE LIMITED MAINLY TO THE AFTERNOON AND EVENING HOURS THIS TIME. AS HEIGHTS CONTINUE TO FALL WILL HAVE LARGE SCALE ASCENT THE BOUNDARY WILL BEGIN TO MOVE BACK NORTHWARD AS A WARM FRONT. PRECIPITABLE WATER VALUES WILL STILL BE HIGH SO LOCALLY HEAVY RAINFALL IS EXPECTED WITH SOME STORMS...SO HAVE MENTIONED IN OUR HAZARDOUS WEATHER OUTLOOK. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AN UNSETTLED AND WET EXTENDED FORECAST IS LIKELY ACROSS NY AND NEW ENGLAND WITH PERSISTENT CHANCES OF SHOWERS AND THUNDERSTORMS...AS A MID AND UPPER LEVEL TROUGH WILL INITIALLY IMPACT THE REGION TO CLOSE THE WEEK...AND THEN IT MAY CLOSE OR CUT OFF NEAR THE GREAT LAKES REGION AND SRN ONTARIO FOR THE WEEKEND. THE LATEST GFS/ECMWF/CANADIAN GGEM/ENSEMBLE GUIDANCE AND HPC GRAPHICS ARE IN PRETTY GOOD AGREEMENT FOR AN ACTIVE STRETCH OF WEATHER. THEIR ARE SOME SUBTLE DIFFERENCES FOR THE TIMING OF THE SHORT-WAVE IMPULSE ROTATING THROUGH THE UPPER LEVEL TROUGH...BUT ALL AN ALL...IT IS EXTREMELY DIFFICULT TO FIND A SUSTAINED DRY STRETCH OF WX TO CLOSE JUNE. THU-FRI...A WAVE OF LOW PRESSURE APPROACHES THE FCST AREA FROM THE GREAT LAKES REGION WITH SOME OVER RUNNING SHOWERS AND THUNDERSTORMS AHEAD OF A WARM FRONT. THE WARM FRONT MAY BUST THROUGH PORTIONS OF THE FCST AREA FOR A POTENTIAL OF STRONG THUNDERSTORMS...IF HEATING IS REALIZED. THE DETAILS ARE NEBULOUS AND MURKY...SO WE WILL CALL IT A CHANCE OF SHOWERS AND THUNDERSTORMS...THU INTO THU NIGHT. A S/SW H850 LLJ OF 30-45 KTS WILL TRANSPORT IN SOME GULF MOISTURE...AND PWATS WILL CONTINUE TO RUN ABOVE NORMAL. THE SFC LOW BEGINS TO OCCLUDE AND CLOSE OFF JUST NORTHWEST OF LAKE ONTARIO AND NRN NY ON FRI. THE GFS CONTINUES TO PAINT MODERATE AMOUNTS OF INSTABILITY FOR THE POTENTIAL OF SHOWERS AND THUNDERSTORMS AGAIN. THE SUBTROPICAL HIGH REMAINS ANCHORED DOWNSTREAM CONTINUING A DEEP S/SW FETCH OF MOISTURE. THIS LONG DURATION STRETCH OF WX...BEGINS TO MATERIALIZE INTO POTENTIALLY A CLASSIC GREAT LAKES CSTAR CUTOFF LOW WARM SEASON EVENT. TEMPS LOOK TO RUN SLIGHTLY BELOW TO NEAR NORMAL FOR THE THESE DAYS WITH HIGHS IN THE M70S TO L80S AND LOWS IN THE U50S TO 60S. SAT-MON...THE LONGWAVE TROUGH BEGINS TO AMPLIFY WITH THE EMBEDDED 500 HPA CLOSED CIRCULATIONS OVER THE CNTRL AND ERN GREAT LAKES. A COLD FRONT BEGINS TO STALL OUT NEAR THE ERN CONUS SEABOARD. MULTIPLE SHORT-WAVES LIFT NORTHWARD ON THE EAST SIDE OF TROUGH. PERSISTENT BANDS OF SHOWERS AND THUNDERSTORMS TIMED TO THE DIURNAL HEATING AND THE PROPAGATION OF THE IMPULSES ARE POSSIBLE FOR THE WEEKEND INTO EARLY NEXT WEEK. THEIR IS A SMALL POSSIBILITY THAT DRYING IN THE WAKE OF DISTURBANCES MAY PROMOTE MINI DRY STRETCHES. AGAIN...THIS APPEARS TO FIT A GREAT LAKES WARM SEASON CSTAR CLOSED/CUTOFF SCENARIO FOR AN EXTENDED PERIOD OF SHOWERS AND THUNDERSTORMS. THE WEEKEND IS DOMINATED BY A POSITIVE TILT SCENARIO...PERHAPS SHIFTING NEUTRAL BY EARLY NEXT WEEK. H850 TEMPS CONTINUE TO BE IN THE +14C TO +16C RANGE WITH LIMITED HEATING EACH DAY WITH A RESIDUAL COLD POOL ALOFT...AND THE ACTIVE S/SW FLOW. EXPECT HIGHS TO CONTINUE IN THE 70S TO L80S WITH LOWS IN THE U50S TO 60S. TOO EARLY TO PINPOINT LOCATIONS...BUT SOME HYDRO PROBLEMS COULD MATERIALIZE...IF LOCATIONS GET REPEATEDLY HIT BY BANDS OF SHOWERS AND THUNDERSTORMS. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... HIGH PRESSURE NEAR THE MID ATLANTIC REGION WILL CONTINUE TO FUNNEL NORTHWARD WARM AND HUMID AIR THE NEXT FEW DAYS. A WEAK MID LEVEL DISTURBANCE MAY FOCUS SOME ISOLD-SCT SHOWERS AND THUNDERSTORMS THIS AFTERNOON INTO THE EARLY EVENING. VFR CONDITIONS ARE EXPECTED MOST OF THE DAY. THERE IS THE THREAT OF SOME DIURNALLY TIMED SHOWERS AND THUNDERSTORMS. OUR CONFIDENCE REMAINS AT ABOUT 25 TO 30 PERCENT FOR THUNDERSTORMS...SO A VCSH GROUP HAS BEEN USED IN THE TAFS AT THIS TIME IN THE 18Z-00Z TIME FRAME. IN THE WAKE OF THE DISTURBANCE THE SKIES WILL CLEAR AND SOME PATCHY MIST/FOG MAY FORM AGAIN PRIOR OR JUST AFTER MIDNIGHT AT ALL THE TAF SITES. THE WINDS WILL INCREASE FROM THE SOUTH TO SOUTHWEST AT 5-10 KTS...AND VEER TO THE WEST TO SOUTHWEST AT AROUND 10 KTS WITH SOME GUSTS CLOSE TO 20 KTS AT KPSF AND KALB. EXPECT THE WINDS TO BECOME LIGHT TO CALM IN THE EARLY EVENING. OUTLOOK... TUE...MAINLY VFR. CHC -TSRA/-SHRA MAINLY DURING THE AFTN INTO THE EVNG. MVFR-IFR FOG LATE AT NIGHT INTO EARLY IN THE MORNING. WED...MAINLY VFR. SLIGHT CHC -TSRA/-SHRA. THU-FRI...VFR/MVFR. CHC -TSRAS/-SHRAS. && .FIRE WEATHER... VERY WARM AND HUMID CONDITIONS WILL CONTINUE EARLY THIS WEEK WITH THE THREAT OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EVENING HOURS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL. OUR NIGHTS WILL BE CONTINUE TO BE MUGGY WITH PATCHY FOG. MORE PERSISTENT CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED LATER IN THE WEEK INTO THE WEEKEND AS A SLOW MOVING LOW PRESSURE SYSTEM IMPACTS THE REGION. && .HYDROLOGY... INCREASING UNSETTLED WEATHER THIS WEEK. EARLY IN THE WEEK THE CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE MAINLY DURING THE AFTERNOON AND EVENING HOURS. HOWEVER...PERSISTENT CHANCES OF SHOWERS AND THUNDERSTORMS ARE EXPECTED FOR THE LATER PART OF THE WEEK INTO THE WEEKEND AS A MID/UPPER LEVEL TROUGH IMPACTS THE REGION. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL ALL WEEK WITH HIGH PRECIPITABLE WATER VALUES. EARLY IN THE WEEK FLOW ALOFT WILL BE RATHER LIGHT SO STORMS WILL BE SLOWER MOVERS. FLOW IS EXPECTED TO INCREASE LATER IN THE WEEK. PONDING OF WATER ON ROADWAYS ALONG WITH MINOR FLOODING OF LOW LYING AND POOR DRAINAGE AREAS WILL BE POSSIBLE. PLUS SOME SMALL STREAMS...CREEKS...AND BROOKS MAY REACH BANKFULL OR EVEN FLOODING QUICKLY IN THE HEAVY RAINFALL ASSOCIATED WITH THE THUNDERSTORMS ESPECIALLY IF STORMS MOVE OVER THE SAME AREA REPEATEDLY. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...IAA NEAR TERM...IAA/SND SHORT TERM...IAA LONG TERM...WASULA AVIATION...WASULA FIRE WEATHER...IAA HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
959 AM EDT MON JUN 24 2013 .SYNOPSIS... A BERMUDA HIGH PRESSURE SYSTEM WILL REMAIN OFF THE SOUTHEAST UNITED STATES COAST FOR THIS UPCOMING WEEK. A BACKDOOR COLD FRONT WILL TRY TO SINK SOUTHWARD INTO THE FORECAST AREA ON WEDNESDAY AND THURSDAY BEFORE RETREATING NORTHWARD. A COLD FRONT WILL MOVE THROUGH THE GREAT LAKES THURSDAY AND FRIDAY IS FORECAST TO APPROACH THE FORECAST AREA SATURDAY AND MOVE THROUGH BY SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE UPPER LOW NOTED IN WV IMAGERY IS MOVING SLOWLY EWD THRU PA THIS MORNING RESULTING IN SW FLOW ALOFT AS WELL AS AT THE SFC. 12Z SOUNDINGS FROM IAD/APG SHOW DECENT CAPE IF CNVCTV TEMPS ARE REACHED...AND ABOUT 1.5 IN PWAT WHICH IS SOMEWHAT ABOVE NORMAL FOR THIS TIME OF YEAR. AMS NEAR THE CENTER OF THE UPPER LOW SEEMS TO BE DRIER BUT COOLER ALOFT SO NOT SURE EXACTLY HOW THIS WILL PLAY OUT FOR AFTN CONVECTION. BOTH THE RAP AND THE HRRR SHOW CNVTN DEVELOPING AROUND 17Z. TODAYS TEMPS WERE TWEAKED UP A DEGREE OR TWO BUT OTRW NO CHANGES TO THE CURRENT FCST. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/... THE UPPER LEVEL LOW WILL CONTINUE TO PROGRESS TOWARDS THE EAST TONIGHT AS IT BECOMES LESS AND LESS DEFINED. THE LAST REMNANTS OF THE EVENING CONVECTION SHOULD ALSO BE MOVING OUT OF THE REGION OR AT LEAST OVER OUR NORTHERN ZONES BY LATE EVENING. HI-RES MODELS STILL SHOW A FEW MID-LEVELS RIPPLES PULLING THROUGH IN THE MAINLY ZONAL FLOW ALOFT SO A FEW PASSING SHOWERS LATE TONIGHT IS STILL POSSIBLE ALTHOUGH THEY WILL BE MORE ISOLATED. EXPECT MORE CLEARING TO TAKE PLACE WHEN COMPARED TO SUNDAY NIGHT WHICH SHOULD ALLOW US TO RADIATE A BIT MORE. THE SURFACE FLOW SHOULD BECOME LIGHT FROM THE SOUTHWEST...AGAIN, BUT THIS TIME WE COULD SEE SLIGHTLY COOLER DEWPOINTS ADVECTED INTO THE REGION. ONCE AGAIN NOT QUITE SURE THE EXTENT OF ANY FOG FORMATION AND QUITE FRANKLY THE GUIDANCE IS NOT ALL THAT EXCITED EITHER...WILL KEEP IN PATCHY FOG FOR TONIGHT. TEMPERATURES TONIGHT SHOULD BE A COUPLE DEGREES COOLER THAN SUNDAY NIGHT OUTSIDE THE URBAN HEAT ISLAND. USED A BLEND OF THE MET/MAV WITH HEAVIER WEIGHTING TOWARDS THE COOLER MAV. && .LONG TERM /TUESDAY THROUGH SUNDAY/... SEVERAL ABOVE NORMAL TEMPERATURE DAYS IN STORE FOR THE AREA WITH PLENTY OF HUMIDITY ALSO. THE BERMUDA HIGH PRESSURE AREA WILL SLOWLY LOSE ITS INFLUENCE ON OUR WEATHER AS A DEEPENING TROUGH AND SFC LOW MOVE INTO THE AREA FRI AND INTO THE WEEKEND. WE HAVE MOSTLY USED WPC TEMPS/POPS FOR THE OVERNIGHT EXTENDED PACKAGE. THERE WILL BE DAILY CHCS FOR SHOWERS/TSTMS DURING THE EXTENDED PERIOD. THE ADDED CLOUDINESS AND SHOWERS WILL TEMPER THE MAGNITUDE OF THE ABOVE NORMAL TEMPERATURES. WE ARE FORECASTING HIGH TEMPERATURE READINGS TO REACH THE LOW 90S IN MANY AREAS TUE-THU WITH PERHAPS A FEW MID 90S ON WED. HUMIDITY LEVELS WILL BE MODERATE/HIGH WITH DEW POINTS IN THE MID 60S TO AROUND 70S. THIS WILL PRODUCE APPARENT TEMPERATURES IN THE LOW/MID 90S ACROSS THE AREA. IT MAY BE NECESSARY TO ISSUE SOME HEAT RELATED HEADLINES AS WE MOVE TOWARD THE MID-WEEK PERIOD. OVERNIGHT LOWS WILL MOSTLY BE IN THE MID/UPPER 60S WITH SOME LOW 70S ACROSS METRO PHILADELPHIA. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A PLUME OF LOW CLDS WITH IFR CIGS FORMED EARLIER THIS MORNING OFF THE NRN END OF CHES BAY AND AFFECTED BOTH PHL AND ILG FOR A COUPLE OF HOURS. AS OF 1230Z THESE CLOUDS HAD DISSIPATED AND VFR CONDS PREVAIL. TODAY...VFR WITH SOUTHWEST WINDS. A WEAK SURFACE TROUGH WILL PUSH IN FROM THE WEST THIS AFTERNOON AND COULD PROVIDE ENOUGH LIFT TO SPARK WIDELY SCATTERED SHOWERS. DID NOT PLACE THESE IN THE TAFS AT THIS TIME GIVEN LACK OF SPATIAL COVERAGE AND LOW CONFIDENCE ON INITIATION. TONIGHT...THE SYSTEM THAT HAS BEEN KEEPING THE MID AND HIGH DECK AROUND FOR THE PAST COUPLE OF DAYS IS FORECAST TO MOVE TO OUR NORTHEAST TONIGHT. THIS WOULD ALLOW SKIES TO BECOME CLEARER THAN ON PAST NIGHTS AND FOR BETTER RADIATIONAL COOLING TO TAKE PLACE. ANY ADDED MOISTURE FROM THE SHOWERS WILL HELP FOR ANOTHER ROUND OF GROUND FOG TO FORM. DO NOT HAVE THE CONFIDENCE YET TO PLACE IN THE TAFS BUT WE WILL HAVE A BETTER CHANCE IF SKIES REALLY DO CLEAR OUT. OUTLOOK... TUE-WED...MOSTLY VFR WITH SHORT PERIODS OF SUB-VFR IN MORNING FOG AND/OR SCT SHOWERS/TSTMS. THU-FRI...VFR/MVFR IN MORE NUMEROUS SHOWERS/TSTMS. && .MARINE... ANOTHER TRANQUIL DAY IS EXPECTED ACROSS OUR WATERS WITH SOUTHWEST WINDS AROUND 10-15KTS. STILL COULD SEE SOME GUSTS UPWARDS OF 20KTS SEAS WILL CONTINUE TO BE AROUND 3 FEET TODAY AND THEN GRADUALLY BUILD UPWARDS OF 4 FEET BY TONIGHT. OUTLOOK... SUB-SCA CONDITIONS MUCH OF THE WEEK WITH MOSTLY SW/S WINDS ON THE WATERS. SCA WINDS/SEAS POSSIBLE FRI. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...O`HARA NEAR TERM...AMC SHORT TERM...HEAVENER LONG TERM...O`HARA AVIATION...AMC/HEAVENER/O`HARA MARINE...HEAVENER/O`HARA
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1052 AM EDT MON JUN 24 2013 .UPDATE... 500MB ANALYSIS SHOWS A TROUGH ACROSS WESTERN AL. THIS FEATURE HAS SERVED TO FOCUS MOSTLY SHOWERS THIS MORNING ACROSS NORTH CENTRAL AL...AND NOW NW GA. DO THINK ANY SCT PRECIP LATE THIS MORNING AND EARLY AFTERNOON WILL BE CONCENTRATED CLOSEST TO THE TROUGH. HOWEVER...FOR THE REMAINDER OF THE AFTERNOON...DO THINK PRECIP WILL FOCUS JUST ALONG AND AHEAD OF THE SEA BREEZE ACROSS THE SE CWFA. THE 12Z RUN OF THE HRRR SHOWS THIS FAIRLY WELL. 12Z SOUNDING ANALYSIS SHOWS A MOIST COLUMN UP THROUGH 750MB WITH LIGHT SW FLOW IN THE BOUNDARY LAYER. PWATS ARE AROUND AN INCH AND THREE QUARTERS...SO ANY THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY DOWNPOURS. SURFACE WILL REMAIN PRETTY UNSTABLE THROUGH THE DAY...SO SCT/NRMS TSTMS WILL BE POSSIBLE. A FEW THUNDERSTORMS COULD BECOME STRONG AND PRODUCE PROLIFIC LIGHTNING STRIKES...BUT THE POTENTIAL FOR SEVERE WEATHER IS RATHER LOW. && .PREV DISCUSSION... /ISSUED 734 AM EDT MON JUN 24 2013/ SHORT TERM /TODAY THROUGH TUESDAY/... /ISSUED AT 402 AM EDT MON JUN 24 2013/ CURRENT CONVECTION OVER THE NORTHEAST MOUNTAINS RESPONDING TO A MOIST UPSLOPE FLOW ALOFT. THIS WILL SLOWLY SHIFT INTO NORTH CAROLINA HOWEVER THERE REMAINS ENOUGH OF A RISK TO KEEP LOW POPS GOING INTO THE MID MORNING HOURS. ISOLATED SHOWERS HAVE ALSO DEVELOPED ACROSS PARTS OF SOUTH AND EAST GA RESPONDING TO A WEAK SHORT WAVE IN THE MID LEVELS. THIS KEEPS ENOUGH OF A RISK TO KEEP LOW POPS GOING INTO THE MID MORNING HOURS AS WELL OVER PARTS OF CENTRAL GA. A SHORT WAVE MOVING THROUGH THE MISSISSIPPI VALLEY WILL MOVE INTO THE CWA THIS AFTERNOON. COMBINING THIS WITH AMPLE GULF AND ATLANTIC MOISTURE SHOULD AID IN SCATTERED TO NUMEROUS THUNDERSTORMS THIS AFTERNOON...MOST NUMEROUS ACROSS CENTRAL GA WHERE LIKELY POPS SEEM IN ORDER. CONVECTION SHOULD DIMINISH AFTER SUNSET WITH SOME LINGERING SHOWERS ACROSS THE NORTHEAST MOUNTAINS AND ALSO CENTRAL GA INTO THE MORNING HOURS ON TUESDAY. RISING H5 HEIGHTS WILL INCREASE THICKNESSES TODAY. THIS SHOULD PRODUCE WARMER TEMPS TODAY. THE NAM IS A BIT COOLER AND HAVE OPTED FOR THE WARMER GFS BOTH TODAY AND TUESDAY. 17 LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... /ISSUED AT 402 AM EDT MON JUN 24 2013/ DIURNAL CONVECTION EXPECTED EACH AFTERNOON AND EVENING THROUGH THE WEEK. MODELS IN GOOD AGREEMENT WITH SURFACE RIDGE LOSING ITS GRIP ON THE SOUTHEAST BY WEEKS END...AND UPPER LEVEL RIDGE BUILDING AND REMAINING OVER THE WESTERN US AS LONG WAVE TROUGH SETS UP OVER THE EAST COAST BY FRIDAY. WITH THE EASTERN EXTENT OF THE UPPER LEVEL RIDGE MORE LIMITED THAN PREVIOUSLY EXPECTED...HAVE COOLED EXTENDED HIGH TEMPERATURES A DEGREE OR TWO. STILL LOOKING FOR HIGHS IN THE UPPER 80S AND LOW 90S. HAVE INCREASED POPS SOMEWHAT FOR THE WEEKEND...AND EXPECT THIS UPWARD TREND IN THE FORECAST TO CONTINUE IN THE COMING DAYS. ENHANCED MOISTURE ACROSS THE REGION AS A RESULT OF THE UPPER LEVEL TROUGH AND ASSOCIATED FRONTAL BOUNDARY SHOULD SUPPORT MORE SIGNIFICANT COVERAGE OF PRECIP ACTIVITY. ANTICIPATE FRONTAL PASSAGE BY EARLY NEXT WEEK...WITH DROP IN POPS AND SLIGHTLY COOLER TEMPERATURES IN STORE AS A RESULT. 31 AVIATION... 12Z UPDATE... WIDESPREAD IFR CIGS SHOULD LIFT TO MVFR BY MID MORNING AND VFR BY NOON. EXPECT CONVECTION TO START AROUND NOON AND BECOME SCATTERED ACROSS NORTH GA AND NUMEROUS ACROSS CENTRAL GA. THE CONVECTION SHOULD DISSIPATE AFTER SUNSET. WINDS WILL BE SOUTHWEST THROUGH THE FORECAST BUT WITH SPEEDS LESS THAN 10 KTS. IFR CIGS SHOULD DEVELOP LATE TONIGHT ACROSS THE FORECAST AREA. //ATL CONFIDENCE...12Z UPDATE... MEDIUM ON CIG HGTS EARLY THIS MORNING. HIGH ON OCCURRENCE OF CONVECTION THIS AFTERNOON...LOW ON IMPACTS TO ATL. 17 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 87 69 89 70 / 40 40 30 20 ATLANTA 88 71 88 72 / 30 30 30 20 BLAIRSVILLE 83 63 84 65 / 40 40 30 20 CARTERSVILLE 87 68 88 70 / 30 30 30 20 COLUMBUS 91 73 92 73 / 60 60 30 20 GAINESVILLE 86 69 88 71 / 40 40 30 20 MACON 89 70 91 72 / 60 60 30 20 ROME 89 68 91 70 / 30 30 30 20 PEACHTREE CITY 88 68 90 70 / 40 40 30 20 VIDALIA 91 73 91 74 / 60 60 30 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...LISTEMAA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1029 AM CDT MON JUN 24 2013 .DISCUSSION... ISSUED 1028 AM CDT MON JUN 24 2013 HAVE MADE ONLY MINOR CHANGES TO GRIDS AND ZFP THIS MORNING TO REFLECT THE CONTINUED POTENTIAL FOR THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS NORTH OF I-74. HRRR RUNS CONTINUE TO ALTERNATE BETWEEN LOW POPS FOR THE REMAINDER OF THE DAY AND AN MCS ROLLING ACROSS THE REGION. WITH SHORTWAVE NOW MOVING ACROSS IOWA COMBINING WITH ANTICEDENT BOUNDARIES AND ABUNDANT PRECIP WATER...OVER 2 STANDARD DEVIATIONS ABOVE CLIMATOLOGY...HAVE INCREASED POPS NORTH OF I-74 AND LOWERED HIGHS THERE. HAVE ALSO MADE SOME ADJUSTMENTS TO REFLECT ONLY SCTATERED CLOUDS IN KIJX/KSPI AREA. BARKER && .AVIATION... ISSUED 600 AM CDT MON JUN 24 2013 MAIN CONCERN WILL BE COVERAGE OF STORMS AGAIN TODAY AND THEIR AFFECT ON CIGS AND VSBYS...OTHERWISE...WE EXPECT MAINLY VFR CONDITIONS DURING THIS PERIOD (TIL 12Z TUE). MAIN BAND OF STORMS HAS STAYED ROUGHLY NORTH OF A PIA TO BMI LINE THIS MORNING. PIA EXPERIENCING SOME OCCASIONAL MVFR CIGS WITH SOME OF THE HEAVIER SHOWERS THIS MORNING BUT AS THE AREA OF RAIN GRADUALLY SHIFT TO THE NORTH AND EAST LATER IN THE MORNING...EXPECT MAINLY VFR CONDITIONS TO PREVAIL AT PIA. SCATTERED STORMS ARE AGAIN EXPECTED THIS AFTN INTO EARLY THIS EVENING (ROUGHLY FROM 20Z-02Z) AS ANOTHER WEAK UPPER LEVEL DISTURBANCE BRINGS THE ROUND OF STORMS THRU. COVERAGE AT THIS POINT LOOKS TO SCATTERED TO INCLUDE A TEMPO GROUP FOR ANY ONE SITE SO WILL CONTINUE WITH VCTS. SFC WINDS WILL BE SOUTHERLY 12 TO 17 KTS TODAY AND AROUND 10 KTS TNT. SMITH && .PREV DISCUSSION... ISSUED 240 AM CDT MON JUN 24 2013 ONGOING PARADE OF MCS ACTIVITY AND ASSOCIATED HEAVY RAINFALL WILL CONTINUE TO BE A CONCERN FOR A COUPLE MORE DAYS. LATEST MCS COVERED A GOOD PORTION OF IOWA...ALBEIT A BIT SMALLER THAN RECENT NIGHTS...AND WAS BEING FED BY 40-45 KNOT LOW LEVEL JET. HAVE HAD SOME STRONG THUNDERSTORMS SPREADING INTO THE NORTHWEST CWA OVER THE LAST COUPLE HOURS ALONG A VERY SUBTLE SURFACE BOUNDARY. MESOSCALE VORTEX FROM SUNDAY CONVECTION OVER THE SOUTHEAST CWA STILL EVIDENT ON RADAR IMAGERY JUST EAST OF MOUNT VERNON. SHORT TERM...TODAY THROUGH WEDNESDAY... AS THE CASE HAS BEEN OVER THE LAST FEW DAYS...MODEL SOLUTIONS ARE FAIRLY VARIED WITH MESOSCALE FEATURES NOT HANDLED ESPECIALLY WELL. MCV IS ROTATING SOUTHEAST AND ACTIVITY WITH THIS FEATURE SHOULD BE OUT OF OUR AREA BY SUNRISE...SO AM PLANNING TO KEEP THE FAR SOUTHEAST DRY THIS MORNING. FOCUS DURING THE MORNING WILL MORE BE ACROSS THE NORTHWEST AND ANY INFLUENCES FROM LEFTOVER BOUNDARIES AND NEWER ONES FROM THE CURRENT CONVECTION. WILL HAVE THE HIGHEST POPS DURING THE AFTERNOON AS MORE OF THE DAYTIME HEATING IS A FACTOR. PRECIPITABLE WATER VALUES AROUND 1.7 TO 1.8 INCHES POINT TO SOME HEAVY DOWNPOURS AGAIN...ALTHOUGH CENTRAL PARTS OF THE CWA ARE MORE ABLE TO HANDLE THE HEAVY RAIN THAN THE SOUTHEAST...WHERE 1-HOUR FLASH FLOOD GUIDANCE IS ONLY AROUND A HALF INCH FROM EFFINGHAM TO FLORA. MAIN SEVERE WEATHER RISK WILL BE WEST OF I-55 THIS AFTERNOON WHERE 0-6KM SHEAR EXPECTED TO INCREASE TO AROUND 40 KNOTS...ALTHOUGH A PULSE SEVERE STORM CANNOT BE RULED OUT ELSEWHERE. MAIN THUNDERSTORM FOCUS SHIFTS NORTHWARD LATE TONIGHT THROUGH TUESDAY NIGHT. WITH MORE SUNSHINE...TUESDAY SHOULD BE THE HOTTEST DAY OF THE WEEK WITH HEAT INDEX VALUES AT OR JUST ABOVE 100. HAVE SOME CONCERN FOR SIMILAR VALUES WEDNESDAY...ALTHOUGH THIS WILL DEPEND ON TIMING OF A FRONTAL PASSAGE AND ASSOCIATED THUNDERSTORMS. MORE WIDESPREAD RISK OF SEVERE WEATHER EXPECTED ON WEDNESDAY WHICH WOULD HELP TEMPER THE HIGHS SOMEWHAT. SOME ADDITIONAL HEAVY RAIN LIKELY AGAIN ON WEDNESDAY WITH THE STORMS... AS PWAT VALUES RISE BACK TO AROUND 1.8 INCHES. LONG TERM...THURSDAY THROUGH SUNDAY... UPPER RIDGING STILL PROGGED TO BUILD ACROSS THE WESTERN CONUS DURING THE LATTER PART OF THE WEEK...WITH A SLOW COOLING TREND. CYCLONIC FLOW OVER THE GREAT LAKES JUSTIFIES SOME LOW CHANCE POPS OR SLIGHT CHANCES THURSDAY THROUGH FRIDAY...BUT THIS SHOULD FADE AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST OVER THE WEEKEND. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
629 AM CDT MON JUN 24 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 352 AM CDT MON JUN 24 2013 ANOTHER DIFFICULT FORECAST AS MESOSCALE FEATURES CONTINUE TO DEFINE CONVECTIVE POTENTIAL...AND ARE DIFFICULT TO FORECAST MORE THAN A FEW HOURS OUT. FOR TODAY...SOUNDINGS SUGGEST WAVE LIFTING OUT OF OK/CTRL KS MAY SATURATE MID LEVELS ENOUGH TO SUPPORT SOME ISOLATED CONVECTION THIS MORNING...AND WILL LEAVE AN ISOLATED POP TO REFLECT THIS. HRRR MODEL...WHICH HAS PERFORMED WELL IN THE MORNING RUNS THIS WEEK...DEPICTS CONVECTIVE COMPLEX OVER SC NEBRASKA SLIDING SLIGHTLY TO THE SE AND BACK-BUILD INTO OUR FORECAST AREA LATER THIS MORNING. FRONTAL BOUNDARY HAS SHIFTED FARTHER NORTHWARD AND SUSPECT COMPLEX WILL STAY NORTH OF THE FA. ALSO SHOULD CONSIDER OUTFLOW MOVING SE OUT OF IOWA CONVECTION AND WHERE THAT MAY END UP ON THE KS/MO BORDER THIS AFTERNOON. AT THIS TIME LESS CINH AND BETTER DYNAMICS COME TOGETHER NORTH OF THE AREA. HAVE STARTED WITH A SILENT POP IN THE NE COUNTIES AND WILL MONITOR FOR DEVELOPMENT. BREEZY SOUTHERLY WINDS WILL BE NEAR BUT GENERALLY BELOW WIND ADVISORY CRITERIA AND WILL HOLD OFF FOR NOW. HIGHS TODAY IN THE 90S FOLLOWED BY WARM OVERNIGHT LOWS IN THE MIDDLE 70S. WITH ANOTHER COMPLEX MOVING NORTH OF THE FORECAST AREA LATE MONDAY INTO EARLY TUESDAY...WILL CARRY A SLIGHT CHANCE POP ACROSS THE FAR NORTHERN COUNTIES AS MAY SEE SOME LATE NIGHT COLD POOL LLJ INTERACTION. 67 .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 352 AM CDT MON JUN 24 2013 MID RANGE AND EXTENDED FORECAST (TUESDAY THROUGH SUNDAY)... WARM...MUGGY...AND DRY CONDITIONS EXPECTED TO PERSIST THROUGH MOST OF THE MID RANGE AND EXTENDED PERIOD. FOR TUESDAY AND WEDNESDAY THE MID LEVEL RIDGE GETS SOMEWHAT FLATTENED OUT AND DEAMPLIFIED AS THE HIGH PRESSURE EXPANDS ACROSS THE SOUTHERN PLAINS. EVENTUALLY...BY MID WEEK THE RIDGE WILL BECOME CENTERED OVER THE FOUR CORNERS REGION OF THE US...AND WILL BECOME MOVE AMPLIFIED AS THE WEEK PROGRESSES. WITH THE EASTERN EDGE OF THE HIGH PRESSURE DOME IN THE VICINITY OF NORTHEAST KANSAS EXPECT SOME MID LEVEL NWLY FLOW TO REMAIN OVER THE FORECAST AREA...WHICH WILL BRING THE POTENTIAL FOR MCS DEVELOPMENT WITHIN THE FLOW. FOR NOW WILL KEEP A MOSTLY DRY FORECAST THROUGH THE EXTENDED PERIOD...WITH THE LONE EXCEPTION OF THURSDAY NIGHT WHERE THE ECMWF AND GFS AGREE ON THUNDERSTORMS DEVELOPING ALONG THE PERIPHERY OF THE RIDGE AND DROPPING SOUTH/SOUTHEASTWARD OUT OF SE NEBRASKA INTO NE KANSAS. GIVEN THE LACK OF ANY STRONG SIGNAL OF OBVIOUS LIFTING MECHANISMS WILL ONLY GO WITH A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS FOR THAT PERIOD. OTHERWISE...EXPECT A RATHER WARM AND MUGGY PERIOD FOR TUES THROUGH THURS AS DAY TIME HIGHS WILL GENERALLY REACH THE MID TO UPPER 90S...WITH HEAT INDEX VALUES RANGING BETWEEN 100 AND 105 ACROSS MOST OF THE FORECAST AREA. TEMPERATURES WILL COOL OFF A BIT FOR THE END OF THE WORK WEEK THROUGH THE WEEKEND...AS A SURFACE HIGH BRINGS COOLER AIR INTO NORTHEAST KANSAS. EXPECT TEMPS FOR FRIDAY THROUGH MONDAY TO BE IN THE UPPER 80S TO PERHAPS THE MID 90S. JL && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 626 AM CDT MON JUN 24 2013 EXPECT ANOTHER DAY WITH BREEZY SOUTH WINDS AND VCTS AT TIMES. HAVE CARRIED 14Z AT MHK WITH 15Z AT TOP/FOE THEN ENDING LATER AFTERNOON HOURS. KEPT WIND SPEEDS UP OVERNIGHT BUT WILL LIKELY NEED TO BRING GUSTS OUT FOR A LATER PERIOD NEXT TAF ISSUANCE. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CRAVEN LONG TERM...LEIGHTON AVIATION...67
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1052 AM CDT MON JUN 24 2013 .MESOSCALE DISCUSSION... ISSUED AT 1052 CDT MON JUN 24 2013 IR AND VISIBILE SATELLITE...AS WELL AS KVWX RADAR IMAGERY SUGGEST A SMALL MESOSCALE VORTEX/SMALL SCALE TROUGH OVER SOUTHWEST INDIANA NEAR KEVV BETWEEN 14Z-15Z. THIS FEATURE SHOULD ENGAGE ENOUGH LIFT TO SUPPORT LOCALIZED UPDRAFTS CAPABLE OF PRODUCING SMALL HAIL /POSSIBLY UP TO NICKLE SIZE/ ALONG AND TO THE EAST AND SOUTHEAST OF THE VORTEX...LEADING INTO THE REMAINDER OF SOUTHWEST INDIANA AND THE PENNYRILE REGION OF WEST KENTUCKY THIS MORNING. ALSO...GIVEN THE SLOW MOVEMENT OF THIS FEATURE /LESS THAN 12 KNOTS/...AND PRECIPITABLE WATER VALUES AROUND TWO INCHES...WOULD NOT BE SURPRISED TO SEE MINIMUM HOURLY RAINFALL VALUES BETWEEN 0.80 AND 1.10 INCHES IN THE HEAVIER RAINFALL CORES. WITH THIS IN MIND...ADDED A MENTION OF SMALL HAIL/HEAVY RAIN TO THE HIGHEST POP CATEGORY AREA FOR THE REMAINDER OF THE MORNING AND INTO THE EARLY AFTERNOON MAINLY FOR HEAVY RAIN. FURTHER TO THE WEST...THETA-E CONVERGENCE OVER SOUTHEAST MO SHOULD CONTINUE TO EVOLVE IN THE WEEK CONVERGENT FLOW...JUST EAST OF THE SOUTHEAST MO FOOTHILLS. SURFACE BASED INSTABILITY WILL REMAIN HIGH...SO ANTICIPATE SOME ISOLATED DEVELOPMENT DURING THE AFTERNOON OVER THE SOUTHEAST MISSOURI FOOTHILL INTO SOUTHWEST ILLINOIS...MAINLY WEST OF INTERSTATE 57. AM ALSO CONCERNED WITH DIFFERENTIAL HEATING AND AN INSTABILITY GRADIENT WEST OF THE CURRENT CONVECTION THIS AFTERNOON...WITH WEAK SURFACE CONVERGENCE LEADING TO AT LEAST SOME RENEWED...BUT BRIEF DEVELOPMENT FROM THE LAND BETWEEN THE LAKES NORTHWARD TO THE CONFLUENCE OF THE OHIO/WABASH RIVER...WEST OF THE CURRENT CONVECTIVE ACTIVITY THIS MORNING. THE 3KM HRRR AND 4KM NAM-WRF /NMM VERSION/ SEEM TO PICK UP ON THESE FEATURES AND SO TRIED TO ADJUST ACCORDINGLY. AN URBAN AND SMALL STREAM FLOOD ADVISORY WILL LIKELY BE POSTED FOR THOSE COUNTIES ALONG AND EITHER SIDE OF THE MCV THIS MORNING AND INTO THE EARLY AFTERNOON TO ACCOUNT FOR THE EFFICIENT RAINFALL WITH THE STRONGER THUNDERSTORM CORES. && .UPDATE... ISSUED AT 643 AM CDT MON JUN 24 2013 UPDATED AVIATION DISCUSSION FOR 12Z TAFS. && .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 354 AM CDT MON JUN 24 2013 WEAK FLOW PATTERN WILL PERSIST ACROSS MUCH OF THE SOUTHERN AND EASTERN U.S. THROUGH MID WEEK. AS A RESULT...MUCH OF THE LOCAL WEATHER PATTERN WILL BE DRIVEN BY MESOSCALE INFLUENCES TYPICALLY NOT HANDLED WELL BY OPERATIONAL MODELS. THE MAIN INFLUENCE TODAY APPEARS TO BE AN MCV CURRENTLY DRIVING CONVECTIVE ACTIVITY OVER SOUTHEAST ILLINOIS AND SOUTHWEST INDIANA. THE LATEST NAM AND HRW- WRF RUNS APPEAR TO HAVE THE BEST HANDLE ON THIS FEATURE. FOLLOWING THIS GUIDANCE...THE BEST POTENTIAL FOR SHOWERS AND THUNDERSTORMS TODAY APPEARS TO BE OVER THE EASTERN HALF OF THE AREA...ESPECIALLY SOUTHEAST ILLINOIS...SOUTHWEST INDIANA...AND THE PENNYRILE REGION OF WESTERN KENTUCKY...AS THE MCV SLOWLY WORKS ITS WAY EAST ACROSS THE AREA. WILL MAINTAIN THE POTENTIAL FOR ISOLATED MAINLY DIURNALLY DRIVEN STORMS ELSEWHERE. MOST MODELS ARE IN AGREEMENT THAT THE CHANCE FOR THUNDERSTORMS SHOULD DROP OFF CONSIDERABLY TONIGHT THROUGH TUESDAY NIGHT WITH NO SUBSTANTIAL FOCUSING MECHANISM. BETTER CHANCES FOR ISOLATED ACTIVITY SHOULD BE CONFINED TO EASTERN AREAS AGAIN ON TUESDAY. IT WILL REMAIN VERY WARM AND HUMID THROUGH THE NEAR TERM...WITH LOWS IN THE LOWER 70S AND HIGHS IN THE LOWER 90S. .LONG TERM...(WEDNESDAY THROUGH SUNDAY) ISSUED AT 354 AM CDT MON JUN 24 2013 THE MODELS CONTINUE TO ADVERTISE WHAT HAS BEEN FORECAST FOR A FEW DAYS NOW. A SIGNIFICANT MID LEVEL HIGH CENTER OVER THE INTERMOUNTAIN WEST WILL BECOME ESTABLISHED...WHILE A TROF OVER THE NE/ERN U.S. MORPHS INTO A CLOSED LOW FEATURE AROUND THE GREAT LAKES REGION BY THE WEEKEND ENHANCING THE TROF ALL THE WAY TO THE GULF COAST. THIS WILL PLACE US IN AN UNSETTLED NW FLOW REGIME ALOFT WITH A SOMEWHAT ILL DEFINED SURFACE PRESSURE PATTERN...THAT SHOULD CONTAIN MORE THAN ONE SUBTLE WIND SHIFT UNTIL FRIDAY NIGHT WHEN THE FINAL ONE SHOULD MOVE THROUGH ONCE THE TROF DEEPENS ENOUGH. PRECIP CHANCES NOT REAL CLEAR CUT IN THIS FLOW PATTERN. HARD TO RULE OUT GIVEN THE TIME OF YEAR AND UNSETTLED NATURE TO THE FLOW. GIVEN TIMING ISSUES AND MODEL VARIANCE WHICH IS YIELDING LOW CONFIDENCE...WILL KEEP POPS IN CHECK AND LOW FOR NOW. THERE IS STILL SOME PERSISTENCE WITH RESPECT TO LATE WEDNESDAY INTO WEDNESDAY NIGHT...IN THAT THERE MAY BE A CONVECTIVE SYSTEM THAT WILL AFFECT THE AREA. TEMPS ARE A BLEND OF ECMWF LONG RANGE MOS / GFS MOS AND HPC GUIDANCE. && .AVIATION... ISSUED AT 643 AM CDT MON JUN 24 2013 A MESOSCALE VORTEX WILL CONTINUE TO TOUCH OFF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS AT KEVV AND KOWB THROUGH MID MORNING...WITH DRY CONDITIONS ELSEWHERE. ISOLATED TO WIDELY SCATTERED THUNDERSTORMS MAY DEVELOP IN THE HEAT OF THE DAY JUST ABOUT ANYWHERE...BUT LOW CONFIDENCE PRECLUDES MENTION IN TAFS AT THIS POINT. VFR CONDITIONS WILL OTHERWISE PREVAIL. EXPECT SOUTHERLY WINDS AOB 10 KNOTS. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ MESOSCALE...SMITH SHORT TERM...RJP LONG TERM...CN AVIATION...RJP
AREA FORECAST DISCUSSION
NWS GRAY ME
1205 PM EDT MON JUN 24 2013 .SYNOPSIS... WARM AND MOIST AIR CONTINUES TO POOL ALONG AND SOUTH OF A STATIONARY FRONT SITUATED TO OUR NORTH. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH DAY THROUGH THE WEEK AS SEVERAL DISTURBANCES CROSS THE REGION. A LARGE UPPER LEVEL TROUGH WILL APPROACH FROM THE WEST LATE IN THE WEEK. THIS WILL ALLOW FOR COOLER TEMPERATURES...BUT INCREASE THE CHANCE FOR SHOWERS ACROSS THE REGION. && .NEAR TERM /TODAY/... NOON UPDATE... HAVE MADE CHANGES TO THE POP STRUCTURE THROUGH THE AFTERNOON. CUMULUS FIELD NOTED ON VISIBLE SATELLITE BUT NOTHING THAT IS READY TO DEVELOP DEEP CONVECTION. SOME CONVECTION DEVELOPING OVER THE ADIRONDACKS IN NEW YORK STATE WILL MOVE EAST THROUGH THE AFTERNOON. ADDITIONAL DEVELOPMENT IS MOST LIKELY OVER THE HIGHER TERRAIN OF NEW HAMPSHIRE AND NORTHWEST MAINE BUT COULD ALSO OCCUR ON THE COASTAL PLAIN LATER IN THE AFTERNOON ONCE TEMPERATURES REACH THEIR PEAK AND THE CAP BECOMES SUFFICIENTLY OVERCOME. 845 AM UPDATE... HAVE UPDATED MOST OF THE GRIDDED FORECAST DATABASE THIS MORNING TO BETTER REFLECT CURRENT FORECAST THINKING. LEFT POP STRUCTURE IN PLACE FOR THIS AFTERNOON AS THERE WILL BE PLENTY OF CAPE AVAILABLE WITH THE HEATING AND HUMIDITY THIS AFTERNOON. HOWEVER... UNSURE THAT THERE WILL BE ENOUGH OF A FOCUSING MECHANISM TO HELP US OVERCOME THE CAP. SEEMS LIKE THE BEST CHANCE WOULD BE TO GET SOME STORMS GOING OVER THE MOUNTAINS. IF THIS DOES OCCUR... IT APPEARS THAT HAIL AND WINDS WILL BE THE PRIMARY THREAT. WITH NEW DEW POINT FORECAST... SOME AREAS OF SOUTHWEST MAINE SEE HEAT INDEX VALUES REACH THE UPPER 90S TO NEAR 100 THIS AFTERNOON BUT NOT WIDESPREAD ENOUGH FOR A HEAT ADVISORY. 630AM UPDATE... UPDATE EARLY THIS MORNING TO LOWER THE CHANCES OF PRECIPITATION OVER MUCH OF THE REGION THIS MORNING. THE EXCEPTION CONTINUES TO BE THE NORTH AND MOUNTAINS WHERE OLD MCS CONTINUES TO DETERIORATE AND MOVE EAST ACROSS MAINE. LATEST HRRR MODEL IS PICKING UP ON THIS SYSTEM WELL THIS MORNING. TIMING OF CONVECTIVE INITIATION TODAY APPEARS TO BE AROUND 16Z- 18Z OVER VERMONT. CELLS WILL ENTER NEW HAMPSHIRE BY AROUND 19Z OR 20Z AND SPREAD QUICKLY TO THE EAST. OTHERWISE...HAVE MADE SOME MINOR ADJUSTMENTS TO THE CLOUD...DEW POINT AND MAX TEMPERATURE GRIDS BASED ON CURRENT TRENDS AND OBSERVATIONS. PREVIOUS DISCUSSION... THE REMAINS OF AN MCS WILL CROSS NORTHERN SECTIONS EARLY THIS MORNING...AS IT CONTINUES TO WEAKEN AS IT MOVES EAST. A DEVELOPING WESTERLY FLOW ALOFT WILL ALLOW 850 MB TEMPERATURES TO CLIMB TO AT OR ABOVE +16C DURING THE AFTERNOON HOURS. WITH AMPLE MIXING...WE SHOULD EXPECT SOME LOWER 90S OVER SOUTHERN/CENTRAL NEW HAMPSHIRE AND ADJACENT SECTIONS OF WESTERN MAINE. THERE WILL BE A SURFACE TROUGH SITUATED NEAR AND ALONG THE COASTLINE...SO ONSHORE WINDS WILL LIKELY KEEP THINGS COOLER OVER THE MIDCOAST REGION. CAPES SOAR THIS AFTERNOON INTO THE 1500 J/KG RANGE OVER SOUTHERN MAINE AND POSSIBLY SOUTHERN NEW HAMPSHIRE DURING THE AFTERNOON HOURS TODAY AS A SHORT WAVE APPROACHES FROM THE WEST. LI VALUES DROP SIGNIFICANTLY AS WELL. WE ARE NOT OUTLOOKED BY SPC TODAY...HOWEVER FEEL COMPELLED TO AT LEAST MENTIONED GUSTY WINDS AND SMALL HAIL IN THIS AREA. PRECIPITABLE WATER VALUES WILL BE VERY HIGH TODAY...CLOSE TO 1.75 INCHES. WESTERLY FLOW SHOULD ALLOW FOR QUICK PROGRESSION OF STORMS. NEVERTHELESS...ANY TRAINING ECHOES WILL NEED TO BE MONITORED CLOSELY FOR THE THREAT OF HEAVY RAINFALL. USED A BLEND OF MAV/MET MOS FOR DAYTIME MAX TEMPERATURES...WHICH PLACES MANY AREAS IN THE LOWER 90S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... PATCHY FOG WILL REDEVELOP TONIGHT...ESPECIALLY IN THE VALLEY LOCATIONS. THEREAFTER...SHOWERS AND THUNDERSTORMS WILL DEVELOP DURING THE EARLY AFTERNOON HOURS ON TUESDAY AS VORT MAX APPROACHES FROM THE NORTH. EXPECT SEVERAL STORMS TO PRODUCE DAMAGING WIND GUSTS AS THE PRIMARY THREAT FOR SEVERE WEATHER AS THE WIND MAX CROSSES THE REGION...BUT WE CANNOT RULE OUT THE POSSIBILITY OF LARGE HAIL AS WELL. WILL HIGHLIGHT THIS IN THE HWO. EXPECT MANY COMMUNITIES TO TOP OUT AT OR ABOVE 90 DEGREES ONCE AGAIN OVER SOUTHERN/CENTRAL NEW HAMPSHIRE AND WESTERN MAINE. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... THRU THE OUTLOOK PERIOD THE EVOLUTION OF A LONG WAVE TROUGH WILL BECOME ESTABLISHED OVER THE EASTERN GREAT LAKES AND EXTEND SOUTH INTO THE OHIO VALLEY. THIS LONG WAVE TROUGH WILL BECOME THE MAIN WEATHER PRODUCER FOR THE FORECAST PERIOD OF WEDNESDAY THROUGH SUNDAY. THE DEVELOPING EASTERN LONG WAVE TROUGH WILL MEAN A CONTINUED MOIST AND UNSTABLE SSW FLOW AT THE SURFACE AND ALOFT THRU THE WEEK. SHOWERS/THUNDERSTORMS ARE EXPECTED THROUGHOUT THE WEEK AND INTO THE WEEKEND. TEMPERATURES WILL BE COOLER THROUGH THE WEEK DUE TO PLENTY OF CLOUDS AND THE MOIST SOUTHERLY FLOW. HIGH TEMPERATURES WILL BE MOSTLY IN THE 70S BUT DEW POINTS WILL REMAIN HIGH SO IT WILL BE MUGGY AS WELL. USED A BLEND OF THE MAV/MET GUIDANCE FOR 4TH/5TH PERIODS AND THEN THE ADJUSTED MEX TEMPERATURES FOR DAYS 4-7. && .AVIATION /16Z MONDAY THROUGH FRIDAY/... SHORT TERM...WEST WINDS TODAY MAY GUST INTO THE LOWER 20S. WINDS AND THE POTENTIAL FOR HAIL IS POSSIBLE OVER SOUTHERN AREAS OF MAINE THIS AFTERNOON AND OVER ALL AREAS ON TUESDAY. LONG TERM... VARIABLE CONDITIONS EXPECTED THRU THE OUTLOOK PERIOD. VFR CONDITIONS ARE EXPECTED AT TIMES BUT WILL LOWER TO MVFR TO IFR IN SCATTERED SHOWERS/THUNDERSTORMS THROUGHOUT THE MIDDLE TO END OF THE WEEK. && .MARINE... SHORT TERM... WINDS MAY BECOME GUSTY OVER THE OUTER WATERS TODAY...BUT MOST LIKELY REMAINING BELOW SCA CRITERIA. SIMILAR CONDITIONS WILL FOLLOW ON TUESDAY. LONG TERM... WINDS/SEAS WILL REMAIN BELOW SCA CONDITIONS THRU THURSDAY BUT MAY INCREASE TO SCA CRITERIA ON FRIDAY DUE TO AN INCREASING SOUTHERLY PRESSURE GRADIENT ALLOWING WINDS AND SEAS TO INCREASE. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ NEAR TERM UPDATE...KIMBLE SHORT TERM...CANNON LONG TERM...MARINE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1021 AM EDT MON JUN 24 2013 .SYNOPSIS... UNSETTLED CONDITIONS WITH SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST THROUGH MID WEEK. && .NEAR TERM /THROUGH TONIGHT/... 10AM UPDATE... THE DECAYING MCS IS BRINGING SHOWERS TO HANCOCK AND WASHINGTON COUNTIES AT THIS TIME AND WILL EXIT THE FORECAST AREA IN THE NEXT FEW HOURS. SKIES WILL CLEAR FROM NW TO SE AS THE CLOUDS ASSOCIATED WITH THE OLD MCS LEAVE THE STATE. THIS WILL PRODUCE HIGHS IN THE MID TO UPPER 80S WITH UNCOMFORTABLE HUMIDITY. ADJUSTED HIGHS UP A FEW DEGREES. DAYTIME HEATING WILL CREATE SOME DESTABILIZATION WITH THE BEST CHANCES FOR STRONG STORMS IN THE REMOTE AREAS OF NORTHERN SOMERSET...PISCATAQUIS AND AROOSTOOK COUNTIES THIS EVENING. STRONG WIND GUSTS WOULD APPEAR TO BE THE BIGGEST THREAT. HOWEVER...WITH A STRONG LLJ...HIGH PWATS AND WELL OVER 10K FT OF WARM CLOUD...HEAVY RAIN IS ALSO A CONCERN. UPDATE 0530L: DECAYING MCS HAS REACHED OUR FAR WRN ZONES ATTM. THIS A LITTLE FASTER THAN ERLYR EXPECTED SO HAVE ADJUSTED POPS FOR CURRENT AND EXPECTED TRENDS THRU THE AM HRS. REMAINDER OF THE FCST UNCHANGED... DECAYING MCS OVR SRN QUEBEC ATTM ABOUT TO ENTER FAR WRN MAINE... OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ACROSS THE FA ATTM W/ SOME FOG ACROSS THE N. NOT MUCH CHANGE IN THE OVERALL PTRN ACROSS OUR AREA LAST 24 HRS AT LEAST IN THE UPPER LEVELS OF THE ATMOS AS BRISK WNW FLOW ALOFT PERSISTS W/ OCNL DISTURBANCES EMBEDDED IN THIS FLOW. IN THE LOWER LEVELS - A VRY WARM AND HUMID SWRLY FLOW IS NOW IN PLACE ACROSS THE ENTIRE REGION W/ TDS GENERALLY IN THE LOWER TO MID 60S. THE DECAYING MCS IS SHOWN BY THE SHORTER TERM MODELS SUCH AS THE RUC TO CONT TO MV ESEWRD AND HOLD TOGETHER ENUF TO HAVE SOME IMPACT ON OUR WRN ZNS ERLY TDY THEN ACROSS OUR S CENTRAL ZNS THRU THE AM HRS AND POPS ACROSS THESE AREAS WILL REFLECT THIS. OTHERWISE...ANOTHER UPPER DISTURBANCE IS FCST TO SLIDE ESEWRD ACROSS THE FA LATER TDY AND PROVIDE ANOTHER UPTICK IN SHOWERS/TSTMS. UNLIKE SUN...WHERE MOST ACTION WAS S OF THE AREA - APPEARS TDY THAT THINGS HAVE SHIFTED A LITTLE FURTHER N W/ THE INTRUSION OF THE WARMER AND MORE HUMID AIR. AS A RESULT...WILL CARRY MAINLY CHC POPS ACROSS THE REMAINDER OF THE FA TDY INTO THIS EVE W/ ACTIVITY EXPECTED TO AGAIN WEAKEN/DISSIPATE LATER THIS EVE AS THIS UPPER DISTURBANCE MVS AWAY FROM THE REGION. THIS WILL SET THE STAGE FOR MORE PATCHY FOG W/ THE FOG PROBABLY A LITTLE MORE WDSPRD THAN THIS AM W/ THE HUMID AIRMASS PERSISTING. TEMPS TDY WILL BE A LITTLE TRICKY... CLDS AND SHOWERS WILL NO DOUBT HAVE SOME IMPACT AND PROBABLY KEEP MOST AREAS FROM REACHING FULL POTENTIAL TDY. STILL...A LITTLE SUNSHINE FROM TIME TO TIME IS EXPECTED AND WILL GO A LONG WAY IN HEATING THINGS UP SO WILL HANG ONTO HIGHS INTO THE LOWER 80S N W/ MID TO PSBLY UPPER 80S CENTRAL AND INTERIOR DOWNEAST... && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... PERIOD WILL BEGIN WITH A SURFACE HIGH SETUP IN THE ATLANTIC AND BOUNDARY DRAPED JUST TO THE NORTH OF THE REGION. THE SURFACE HIGH WILL CONTINUE TO PUMP WARM AND MOIST AIR INTO THE REGION. GUIDANCE IS IN FAIR AGREEMENT WITH THE BOUNDARY AND SURFACE LOW BEGINNING TO DROP SOUTH THROUGH THE DAY ON TUESDAY. THIS COMBINED WITH BETTER UPPER LEVEL DYNAMICS WITH THE REGION LOCATED IN THE FAVORABLE RIGHT ENTRANCE REGION OF UPPER LEVEL JET ENHANCING DIVERGENCE ALOFT. ALSO WITH WARM AND MOIST UNSTABLE AIR IN PLACE CAPE VALUES WILL BE GENERALLY BETWEEN 500 TO 1500 J/KG. THESE DYNAMICS WILL MAKE IT POSSIBLE TO HAVE SOME MORE ENHANCED THUNDERSTORM ACTIVITY TUESDAY AFTERNOON AND EVENING. RIGHT NOW THINKING IS THERE WILL BE THE POTENTIAL FOR SMALL HAIL AND GUSTY WINDS BUT THIS MAY NEED TO BE ENHANCED FURTHER IF DYNAMICS CONTINUE TO COME TOGETHER. BEST CHANCES STILL LOOK TO BE ACROSS THE NORTHERN AND CENTRAL PORTIONS OF THE REGION WHERE BEST SUPPORTING DYNAMICS ARE PRESENT. THERE IS SOME MODEL DIVERGENCE FOR WEDNESDAY WITH THE MOST OF GUIDANCE WANTING TO KEEP THE LOW PRESSURE ACROSS THE REGION WHILE THE 23/12Z ECMWF WANTS TO KEEP IT DRIER. RIGHT NOW WILL KEEP DECENT CONSISTENCY WITH PREVIOUS FORECAST WITH MORE SHOWERY TYPE ACTIVITY. TEMPERATURES FOR WEDNESDAY LOOK TO BE COOLER ALTHOUGH THIS WILL BE HIGHLY DEPENDENT ON CLOUD COVER.&& .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE GUIDANCE IS STILL A BIT DIVERGENT IN THE BEGINNING OF THE LONG TERM PERIOD. THE 24/00Z GFS/GEM WANTS TO HOLD ON TO THE BOUNDARY AND SURFACE LOW A BIT LONGER THAN THE 23/12Z ECMWF FOR WEDNESDAY NIGHT. THEN WE WILL SEE ANOTHER STRONG UPPER LEVEL DISTURBANCE ACROSS THE GREAT LAKES CONTINUE TO PROGRESS EAST. ALL THE LONG RANGE GUIDANCE INDICATES THIS MOVING EAST BUT WITH SLIGHT DIFFERENCES IN TIMING. GENERALLY IT LOOKS LIKE THIS SYSTEM WILL BEGIN PROGRESSING INTO THE REGION THURSDAY AFTERNOON. RIGHT NOW THE GUIDANCE ALSO WANTS INDICATE THIS UPPER LEVEL LOW BECOMING QUASI- STATIONARY GENERALLY ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS WOULD KEEP THE REGION IN A ACTIVE PATTERN THROUGH MUCH OF THE LONG TERM PERIOD. THIS QUASI-STATIONARY TROUGH SETUP IS ALSO GENERALLY SUPPORTED BY THE 23/12Z GFS/ECMWF RESPECTIVE ENSEMBLE MEAN. HIGH AND LOW TEMPERATURES FOR THE PERIOD WILL GENERALLY BE NEAR NORMAL. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... NEAR TERM: VRBL CONDS ACROSS THE AREA THIS AM W/ SOME IFR IN FOG ACROSS THE N TO VFR CONDS ACROSS THE S. EXPECT FOG TO DISSIPATE ERLY THIS AM W/ PREDOM VFR CONDS TDY EXPECT OCNL MVFR TO BRIEF IFR PSBL IN ANY SHOWERS/TSTMS. FOG WILL AGAIN BE A THREAT TNGT ALONG W/ A CONTD CHC OF SHOWERS AND PSBL THUNDER... SHORT TERM: MOST SITES LOOK TO STAY VFR THROUGH THE PERIOD WITH THE EXCEPTION OF THOSE SITES THAT RECEIVE SHOWER AND THUNDERSTORM ACTIVITY. THIS WILL BE MORE LIKELY FOR THE NORTHERN SITES. && .MARINE... NEAR TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THRU TONIGHT. VISIBILITIES COULD BE REDUCED IN PATCHY FOG TODAY AND IN MORE WDSPRD AREAS OF FOG TNGT. SHORT TERM: MARINE: NO HEADLINES EXPECTED AT THIS TIME WITH SEAS GENERALLY STAYING 2 TO 4 FT AND WINDS 10 TO 15 KT. VISIBILITIES COULD BE REDUCED WITH SHOWERS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...KHW/MCW SHORT TERM...JORDAN LONG TERM...JORDAN AVIATION...KHW/MCW/JORDAN MARINE...KHW/MCW/JORDAN
AREA FORECAST DISCUSSION
NWS GRAY ME
852 AM EDT MON JUN 24 2013 .SYNOPSIS... WARM AND MOIST AIR CONTINUES TO POOL ALONG AND SOUTH OF A STATIONARY FRONT SITUATED TO OUR NORTH. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH DAY THROUGH THE WEEK AS SEVERAL DISTURBANCES CROSS THE REGION. A LARGE UPPER LEVEL TROUGH WILL APPROACH FROM THE WEST LATE IN THE WEEK. THIS WILL ALLOW FOR COOLER TEMPERATURES...BUT INCREASE THE CHANCE FOR SHOWERS ACROSS THE REGION. && .NEAR TERM /TODAY/... 845 AM UPDATE... HAVE UPDATED MOST OF THE GRIDDED FORECAST DATABASE THIS MORNING TO BETTER REFLECT CURRENT FORECAST THINKING. LEFT POP STRUCTURE IN PLACE FOR THIS AFTERNOON AS THERE WILL BE PLENTY OF CAPE AVAILABLE WITH THE HEATING AND HUMIDITY THIS AFTERNOON. HOWEVER... UNSURE THAT THERE WILL BE ENOUGH OF A FOCUSING MECHANISM TO HELP US OVERCOME THE CAP. SEEMS LIKE THE BEST CHANCE WOULD BE TO GET SOME STORMS GOING OVER THE MOUNTAINS. IF THIS DOES OCCUR... IT APPEARS THAT HAIL AND WINDS WILL BE THE PRIMARY THREAT. WITH NEW DEW POINT FORECAST... SOME AREAS OF SOUTHWEST MAINE SEE HEAT INDEX VALUES REACH THE UPPER 90S TO NEAR 100 THIS AFTERNOON BUT NOT WIDESPREAD ENOUGH FOR A HEAT ADVISORY. 630AM UPDATE... UPDATE EARLY THIS MORNING TO LOWER THE CHANCES OF PRECIPITATION OVER MUCH OF THE REGION THIS MORNING. THE EXCEPTION CONTINUES TO BE THE NORTH AND MOUNTAINS WHERE OLD MCS CONTINUES TO DETERIORATE AND MOVE EAST ACROSS MAINE. LATEST HRRR MODEL IS PICKING UP ON THIS SYSTEM WELL THIS MORNING. TIMING OF CONVECTIVE INITIATION TODAY APPEARS TO BE AROUND 16Z- 18Z OVER VERMONT. CELLS WILL ENTER NEW HAMPSHIRE BY AROUND 19Z OR 20Z AND SPREAD QUICKLY TO THE EAST. OTHERWISE...HAVE MADE SOME MINOR ADJUSTMENTS TO THE CLOUD...DEW POINT AND MAX TEMPERATURE GRIDS BASED ON CURRENT TRENDS AND OBSERVATIONS. PREVIOUS DISCUSSION... THE REMAINS OF AN MCS WILL CROSS NORTHERN SECTIONS EARLY THIS MORNING...AS IT CONTINUES TO WEAKEN AS IT MOVES EAST. A DEVELOPING WESTERLY FLOW ALOFT WILL ALLOW 850 MB TEMPERATURES TO CLIMB TO AT OR ABOVE +16C DURING THE AFTERNOON HOURS. WITH AMPLE MIXING...WE SHOULD EXPECT SOME LOWER 90S OVER SOUTHERN/CENTRAL NEW HAMPSHIRE AND ADJACENT SECTIONS OF WESTERN MAINE. THERE WILL BE A SURFACE TROUGH SITUATED NEAR AND ALONG THE COASTLINE...SO ONSHORE WINDS WILL LIKELY KEEP THINGS COOLER OVER THE MIDCOAST REGION. CAPES SOAR THIS AFTERNOON INTO THE 1500 J/KG RANGE OVER SOUTHERN MAINE AND POSSIBLY SOUTHERN NEW HAMPSHIRE DURING THE AFTERNOON HOURS TODAY AS A SHORT WAVE APPROACHES FROM THE WEST. LI VALUES DROP SIGNIFICANTLY AS WELL. WE ARE NOT OUTLOOKED BY SPC TODAY...HOWEVER FEEL COMPELLED TO AT LEAST MENTIONED GUSTY WINDS AND SMALL HAIL IN THIS AREA. PRECIPITABLE WATER VALUES WILL BE VERY HIGH TODAY...CLOSE TO 1.75 INCHES. WESTERLY FLOW SHOULD ALLOW FOR QUICK PROGRESSION OF STORMS. NEVERTHELESS...ANY TRAINING ECHOES WILL NEED TO BE MONITORED CLOSELY FOR THE THREAT OF HEAVY RAINFALL. USED A BLEND OF MAV/MET MOS FOR DAYTIME MAX TEMPERATURES...WHICH PLACES MANY AREAS IN THE LOWER 90S. && .SHORT TERM /TONIGHT AND TUESDAY/... PATCHY FOG WILL REDEVELOP TONIGHT...ESPECIALLY IN THE VALLEY LOCATIONS. THEREAFTER...SHOWERS AND THUNDERSTORMS WILL DEVELOP DURING THE EARLY AFTERNOON HOURS ON TUESDAY AS VORT MAX APPROACHES FROM THE NORTH. EXPECT SEVERAL STORMS TO PRODUCE DAMAGING WIND GUSTS AS THE PRIMARY THREAT FOR SEVERE WEATHER AS THE WIND MAX CROSSES THE REGION...BUT WE CANNOT RULE OUT THE POSSIBILITY OF LARGE HAIL AS WELL. WILL HIGHLIGHT THIS IN THE HWO. EXPECT MANY COMMUNITIES TO TOP OUT AT OR ABOVE 90 DEGREES ONCE AGAIN OVER SOUTHERN/CENTRAL NEW HAMPSHIRE AND WESTERN MAINE. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... THRU THE OUTLOOK PERIOD THE EVOLUTION OF A LONG WAVE TROUGH WILL BECOME ESTABLISHED OVER THE EASTERN GREAT LAKES AND EXTEND SOUTH INTO THE OHIO VALLEY. THIS LONG WAVE TROUGH WILL BECOME THE MAIN WEATHER PRODUCER FOR THE FORECAST PERIOD OF WEDNESDAY THROUGH SUNDAY. THE DEVELOPING EASTERN LONG WAVE TROUGH WILL MEAN A CONTINUED MOIST AND UNSTABLE SSW FLOW AT THE SURFACE AND ALOFT THRU THE WEEK. SHOWERS/THUNDERSTORMS ARE EXPECTED THROUGHOUT THE WEEK AND INTO THE WEEKEND. TEMPERATURES WILL BE COOLER THROUGH THE WEEK DUE TO PLENTY OF CLOUDS AND THE MOIST SOUTHERLY FLOW. HIGH TEMPERATURES WILL BE MOSTLY IN THE 70S BUT DEW POINTS WILL REMAIN HIGH SO IT WILL BE MUGGY AS WELL. USED A BLEND OF THE MAV/MET GUIDANCE FOR 4TH/5TH PERIODS AND THEN THE ADJUSTED MEX TEMPERATURES FOR DAYS 4-7. && .AVIATION /13Z MONDAY THROUGH FRIDAY/... SHORT TERM...WEST WINDS TODAY MAY GUST INTO THE LOWER 20S. WINDS AND THE POTENTIAL FOR HAIL IS POSSIBLE OVER SOUTHERN AREAS OF MAINE THIS AFTERNOON AND OVER ALL AREAS ON TUESDAY. LONG TERM... VARIABLE CONDITIONS EXPECTED THRU THE OUTLOOK PERIOD. VFR CONDITIONS ARE EXPECTED AT TIMES BUT WILL LOWER TO MVFR TO IFR IN SCATTERED SHOWERS/THUNDERSTORMS THROUGHOUT THE MIDDLE TO END OF THE WEEK. && .MARINE... SHORT TERM... WINDS MAY BECOME GUSTY OVER THE OUTER WATERS TODAY...BUT MOST LIKELY REMAINING BELOW SCA CRITERIA. SIMILAR CONDITIONS WILL FOLLOW ON TUESDAY. LONG TERM... WINDS/SEAS WILL REMAIN BELOW SCA CONDITIONS THRU THURSDAY BUT MAY INCREASE TO SCA CRITERIA ON FRIDAY DUE TO AN INCREASING SOUTHERLY PRESSURE GRADIENT ALLOWING WINDS AND SEAS TO INCREASE. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ NEAR TERM UPDATE...KIMBLE SHORT TERM...CANNON LONG TERM...MARINE
AREA FORECAST DISCUSSION
NWS GRAY ME
629 AM EDT MON JUN 24 2013 .SYNOPSIS... WARM AND MOIST AIR CONTINUES TO POOL ALONG AND SOUTH OF A STATIONARY FRONT SITUATED TO OUR NORTH. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH DAY THROUGH THE WEEK AS SEVERAL DISTURBANCES CROSS THE REGION. A LARGE UPPER LEVEL TROUGH WILL APPROACH FROM THE WEST LATE IN THE WEEK. THIS WILL ALLOW FOR COOLER TEMPERATURES...BUT INCREASE THE CHANCE FOR SHOWERS ACROSS THE REGION. && .NEAR TERM /THROUGH TONIGHT/... UPDATE... UPDATE EARLY THIS MORNING TO LOWER THE CHANCES OF PRECIPTATION OVER MUCH OF THE REGION THIS MORNING. THE EXCEPTION CONTINUES TO BE THE NORTH AND MOUNTAINS WHERE OLD MCS CONTINUES TO DETEORATE AND MOVE EAST ACROSS MAINE. LATEST HRRR MODEL IS PICKING UP ON THIS SYSTEM WELL THIS MORNING. TIMING OF CONVECTIVE INITIATION TODAY APPEARS TO BE AROUND 16Z- 18Z OVER VERMONT. CELLS WILL ENTER NEW HAMPSHIRE BY AROUND 19Z OR 20Z AND SPREAD QUICKLY TO THE EAST. OTHERWISE...HAVE MADE SOME MINOR ADJUSTMENTS TO THE CLOUD...DEW POINT AND MAX TEMPERATURE GRIDS BASED ON CURRENT TRENDS AND OBSERVATIONS. PREV DISC... THE REMAINS OF AN MCS WILL CROSS NORTHERN SECTIONS EARLY THIS MORNING...AS IT CONTINUES TO WEAKEN AS IT MOVES EAST. A DEVELOPING WESTERLY FLOW ALOFT WILL ALLOW 850 MB TEMPERATURES TO CLIMB TO AOA +16C DURING THE AFTERNOON HOURS. WITH AMPLE MIXING...WE SHOULD EXPECT SOME LOWER 90S OVER SOUTHERN/CENTRAL NH AND ADJACENT SECTIONS OF WESTERN MAINE. THERE WILL BE A SURFACE TROUGH SITUATED NEAR AND ALONG THE COASTLINE...SO ONSHORE WINDS WILL LIKELY KEEP THINGS COOLER OVER THE MIDCOAST REGION. CAPES SOAR THIS AFTERNOON INTO THE 1500 J/KG RANGE OVER SOUTHERN MAINE AND POSSIBLY SOUTHERN NEW HAMPSHIRE DURING THE AFTERNOON HOURS TODAY AS A SHORT WAVE APPROACHES FROM THE WEST. LIS DROP SIGNIFICANTLY AS WELL. WE ARE NOT OUTLOOKED BY SPC TODAY...HOWEVER FEEL COMPELLED TO AT LEAST MENTIONED GUSTY WINDS AND SMALL HAIL IN THIS AREA. PRECIPITABLE WATER VALUES WILL BE VERY HIGH TODAY...CLOSE TO 1.75 INCHES. WESTERLY FLOW SHOULD ALLOW FOR QUICK PROGRESSION OF STORMS. NEVERTHELESS...ANY TRAINING ECHOES WILL NEED TO BE MONITORED CLOSELY FOR THE THREAT OF HEAVY RAINFALL. USED A BLEND OF MAV/MET MOS FOR DAYTIME MAX TEMPERATURES...WHICH PLACES MANY AREAS IN THE LOWER 90S. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... PATCHY FOG WILL REDEVELOP TONIGHT...ESPECIALLY IN THE VALLEY LOCATIONS. THEREAFTER...SHOWERS AND THUNDERSTORMS WILL DEVELOP DURING THE EARLY AFTERNOON HOURS ON TUESDAY AS VORT MAX APPROACHES FROM THE NORTH. EXPECT SEVERAL STORMS TO PRODUCE DAMAGING WIND GUSTS AS THE PRIMARY THREAT FOR SEVERE WEATHER AS THE WIND MAX CROSSES THE REGION...BUT WE CAN`T RULE OUT THE POSSIBILITY OF LARGE HAIL AS WELL. WILL HIGHLIGHT THIS IN THE HWO. EXPECT MANY COMMUNITIES TO TOP OUT AT OR ABOVE 90 DEGREES ONCE AGAIN OVER SOUTHER/CENTRAL NEW HAMPSHIRE AND WESTERN MAINE. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... THRU THE OUTLOOK PERIOD THE EVOLUTION OF A LONG WAVE TROF WILL BECOME ESTABLISHED OVER THE ERN GT LAKES AND EXTEND S INTO THE OHIO VALLEY. THIS L/WV TROF WILL BECOME THE MAIN WX PRODUCER FOR THE FCST PERIOD OF WED-SUN. THE DEVELOPING EASTERN L/WV TROF WILL MEAN A CONTINUED MOIST AND UNSTBL SSWLY FLOW AT THE SFC/ALOFT THRU THE WEEK. SHWRS/TSTMS ARE EXPECTED THROUGHOUT THE WEEK AND INTO THE WEEKEND. TEMPS WILL BE COOLER THROUGH THE WEEK DUE TO PLENTY OF CLOUDS AND THE MOIST SLY FLOW. HIGH TEMPS WILL BE MOSTLY IN THE 70S BUT DEWPOINTS WILL REMAIN HIGH SO IT WILL BE MUGGY AS WELL. USED A BLEND OF THE MAV/MET GUID FOR 4TH/5TH PERIODS AND THEN THE ADJUSTED MEX TEMPS FOR DAYS 4-7. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... SHORT TERM... MOISTURE TRAPPED UNDER AN INVERSION WILL KEEP PERIODS OF LIFR AND VLIFR CEILINGS IN THE TERMINAL FORECASTS EARLY THIS MORNING. WEST WINDS TODAY MAY GUST INTO THE LOWER 20S. WINDS AND THE POTENTIAL FOR HAIL IS POSSIBLE OVER SOUTHERN AREAS OF MAINE THIS AFTERNOON AND OVER ALL AREAS ON TUESDAY. LONG TERM... VARIABLE CONDS EXPECTED THRU THE OUTLOOK PERIOD. VFR CONDS ARE EXPECTED AT TIMES BUT WILL LOWER TO MVFR TO IFR IN SCT SHWRS/TSTMS THROUGHOUT THE MIDDLE TO END OF THE WEEK. && .MARINE... SHORT TERM... WINDS MAY BECOME GUSTY OVER THE OUTER WATERS TODAY...BUT MOST LIKELY REMAINING BELOW SCA CRITERIA. SIMILAR CONDITIONS WILL FOLLOW ON TUESDAY. LONG TERM... WINDS/SEAS WILL REMAIN BLO SCA CONDS THRU THURSDAY BUT MAY INCREASE TO SCA CRITERIA ON FRI DUE TO AN INCREASING SLY PRES GRADIENT ALLOWING WINDS AND SEAS TO INCREASE. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
ISSUED BY NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 527 AM CDT MON JUN 24 2013 .DISCUSSION... SCATTERED THUNDERSTORMS WILL MOVE THROUGH THE FORECAST AREA THIS MORNING. A SEVERE WATCH CONTINUES FOR A FEW OF OUR NEBRASKA COUNTIES UNTIL 6 AM...BUT OVERALL STORMS HAVE WEAKENED AND EXISTING WATCH WILL PROBABLY BE ALLOWED TO EXPIRE ON SCHEDULE. THUNDERSTORMS WILL PROBABLY HAVE ENDED ALTOGETHER BY 18Z AS THE WEAK WAVE CONTINUES TO MOVE NORTHEAST OF THE AREA. ADDITIONAL THUNDERSTORMS COULD DEVELOP IN OUR WESTERN FORECAST AREA LATE THIS AFTERNOON AND COULD CONTINUE THROUGH THE EVENING HOURS WITH A SLIGHT RISK FOR SEVERE STORMS DURING THIS TIME. BEYOND TODAY AND TONIGHT...A PERIOD OF HOT WEATHER WILL CONTINUE THROUGH MOST OF THE REMAINDER OF THE WEEK WITH AFTERNOON TEMPS IN THE MID 90S TO LOWER 100S. THERE IS A WEAK FRONT THAT PUSHES THROUGH THE AREA TUESDAY AFTERNOON...WHICH PROVIDES ONLY VERY SLIGHT RELIEF PRIMARILY TO OUR NORTHERN FORECAST AREA. DID NOT INCLUDE ANY PRECIP CHANCES WITH THE FRONT AS WE MAY BE TOO CAPPED TO GET ANYTHING TO DEVELOP. ALSO LEFT REMAINDER OF FORECAST DRY AS THE REGION REMAINS IN A WEAK RIDGE PATTERN. CONFIDENCE LEVEL IS JUST TOO LOW TO EFFECTIVELY TIME ANY SUBTLE WAVES THIS FAR OUT. && .PREV DISCUSSION... SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 317 PM CDT SUN JUN 23 2013 MORNING MAP ANALYSIS INDICATES QUASI ZONAL TO SOUTHWESTERLY MID TO UPPER LEVEL FLOW OVER THE WESTERN HALF OF THE CONUS...WITH A LONGWAVE RIDGE OVER THE EAST. A COUPLE OF MID LEVEL SHORT WAVES ARE ALSO NOTED...WITH ONE EXTENDING FROM THE UPPER MISSISSIPPI VALLEY INTO THE NORTHERN PLAINS...AND THE OTHER OVER THE SOUTHWESTERN CONUS. MID TO UPPER LEVEL JET ENERGY EXTENDS FROM THE WEST/SOUTHWESTERN CONUS...EAST/NORTHEAST INTO THE CENTRAL PLAINS...AND THEN NORTH INTO SOUTH CENTRAL CANADA BEFORE FLOWING EAST INTO SOUTHEASTERN CANADA AND PORTIONS OF THE NORTHEASTERN CONUS. MID TO UPPER LEVEL FLOW OVER OUR AREA MAXES OUT AT AROUND 60KTS BETWEEN 300MB AND 200MB PER 12Z SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR IMAGERY ALSO SHOWS THE AFOREMENTIONED MID LEVEL SHORT WAVES...ALONG WITH A PAIR OF CLOSED MID LEVEL LOWS. ONE SUCH LOW IS LOCATED OVER EASTERN ALBERTA AND WESTERN SASKATCHEWAN...AND THE OTHER IS OVER THE PACIFIC JUST OFF THE COAST OF THE NORTHWESTERN CONUS. AT THE SURFACE AN AREA OF LOW BAROMETRIC PRESSURE EXISTS OVER SOUTHWESTERN KANSAS...WITH A FRONTAL BOUNDARY EXTENDING NORTHEAST FROM THE LOW INTO NORTH CENTRAL KANSAS AND SOUTHEASTERN NEBRASKA. THE LOW LEVEL WIND FIELD ACROSS MUCH OF OUR CWA REMAINS FROM THE NORTHEAST FOR THE MOST PART...BUT LOCATIONS ACROSS OUR SOUTHEAST SUCH AS KK82...KK61...AND KHJH ARE ALL OBSERVING A SURFACE WIND FROM THE SOUTHEAST. GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN SUGGESTS THE LOW LEVEL BAROCLINIC ZONE WILL PERSIST OVER SOUTHEASTERN PORTIONS OF OUR CWA THIS EVENING INTO TONIGHT BEFORE SURGING NORTH DURING THE DAY MONDAY. THERE ARE INDICATIONS...ESPECIALLY FROM HIGHER RESOLUTION MODELS SUCH AS THE NAM12...OF VERY SUBTLE MID LEVEL PERTURBATIONS MOVING OVERHEAD WITHIN THE MEAN FLOW THIS AFTERNOON AND THIS EVENING. CONFIDENCE ON SUCH A FEATURE PROMOTING PRECIPITATION PRODUCTION ACROSS OUR AREA THIS AFTERNOON AND EVENING REMAINS VERY LOW HOWEVER AND AS A RESULT...WILL CONTINUE RELEGATING ANY AFTERNOON AND EVENING POPS TO OUR SOUTH/SOUTHEASTERN CWA...IN CLOSEST PROXIMITY TO THE AFOREMENTIONED LOW LEVEL BAROCLINIC ZONE AND RESULTANT AXIS OF ENHANCED LOW LEVEL CONVERGENCE AND LIFT. AS FOR THE TIMING OF CONVECTIVE INITIATION THIS AFTERNOON AND EVENING...FORECAST PROXIMITY SOUNDINGS FROM THE NAM...OPERATIONAL GFS...AND RAP ALL SUGGEST A HEALTHY CAP PERSISTING THROUGH AT LEAST 00Z. GIVEN THIS...ITS HARD TO BUY INTO QPF FIELDS FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN...WHICH ALL SUGGEST WIDESPREAD PRECIPITATION WILL BE REALIZED ACROSS PORTIONS OF OUR SOUTHEAST BEFORE 00Z THIS EVENING. HRRR SIMULATED REFLECTIVITY LOOKS MUCH MORE REASONABLE...SUGGESTING VERY ISOLATED CONVECTION OCCURRING ACROSS OUR SOUTHEAST TOWARDS 00Z. GIVEN ALL THIS...CONFIDENCE IS VERY LOW THAT MUCH PRECIPITATION WILL BE REALIZED ACROSS OUR AREA PRIOR TO 00Z...BUT CANNOT COMPLETELY RULE OUT SUCH A SOLUTION AND WILL MAINTAIN ~20% POPS ACROSS OUR SOUTHEAST 23-00Z. 00Z AND BEYOND...FORECAST PROXIMITY SOUNDINGS SUGGEST THE CAPPING INVERSION WILL WEAKEN SOMEWHAT THUS MAKING CONVECTION SOMEWHAT MORE LIKELY...A SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN...AS WELL AS SIMULATED REFLECTIVITY FROM THE HRRR. GIVEN THIS...WILL GO AHEAD WITH SLIGHTLY HIGHER POPS...~%30...00-06Z ACROSS OUR SOUTHEAST. SHOULD SURFACE-BASED CONVECTION BE REALIZED THIS AFTERNOON AND/OR EVENING...THEN SEVERE WEATHER WILL LIKELY RESULT WITH DEEP LAYER MUCAPE VALUES IN THE 2000-4000J/KG WAITING FOR UPDRAFT PRODUCTION AND 30-35KTS OF DEEP LAYER BULK SHEAR FOR UPDRAFT ENHANCEMENT. CERTAINLY LARGE HAIL AND MICROBURST-RELATED WIND GUSTS WILL BE A THREAT...BUT ENHANCED HORIZONTAL VORTICITY IN THE VICINITY OF THE LOW LEVEL BAROCLINIC ZONE COULD ALSO PROMOTE ISOLATED TORNADIC ACTIVITY. WILL CONTINUE SUCH WORDING IN THE HWO AS A RESULT. HEADING INTO THE OVERNIGHT HOURS TONIGHT...THE AXIS OF A ~45KT 850MB JET STREAK IS EXPECTED TO DEVELOP ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS...WITH THE NOSE OF THIS LOW LEVEL JET MOVING INTO SOUTHERN PORTIONS OF OUR CWA BETWEEN 06Z AND 12Z. SHOULD DEEP CONVECTION BE ONGOING ALONG THE LOW LEVEL BAROCLINIC ZONE...THEN INCREASING LOW LEVEL THERMAL ADVECTION ALONG THE AXIS OF THE LOW LEVEL JET COULD CERTAINLY HELP INCREASE SPATIAL COVERAGE OF SAID CONVECTIVE ACTIVITY. ALSO...IN ADDITION TO POSSIBLE THUNDERSTORM ACTIVITY OVER PORTIONS OF OUR CWA THIS AFTERNOON AND EVENING...THUNDERSTORMS ALSO REMAIN POSSIBLE OVER THE CENTRAL HIGH PLAINS. SHOULD HIGH PLAINS CONVECTION DEVELOP THIS AFTERNOON/EVENING AND MOVE EAST TOWARDS OUR AREA TONIGHT...ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY COULD BE REALIZED OVER OUR AREA TONIGHT...ESPECIALLY OUR WEST. THIS IS A SOLUTION SUPPORTED BY THE NAM...OPERATIONAL GFS...SREF-MEAN...AND HRRR. GIVEN ALL THIS...WENT AHEAD WITH RELATIVELY HIGHER POPS ACROSS MUCH OF THE CWA STARTING AROUND 06Z. SEVERE WEATHER COULD CERTAINLY BE POSSIBLE DURING THE EARLY PART OF THE OVERNIGHT HOURS AS THE MORE ROBUST CONVECTION FROM EARLIER IN THE EVENING...SHOULD IT DEVELOP...MAINTAINS ITSELF. THAT BEING SAID...BARRING THE DEVELOPMENT OF AN MCS ACROSS THE REGION...CONVECTIVE ACTIVITY SHOULD WANE IN INTENSITY AS POTENTIAL INSTABILITY DECREASES 06Z ONWARD. THERE COULD SOME LINGERING SHOWER AND THUNDERSTORM ACTIVITY ACROSS OUR AREA AROUND SUNRISE MONDAY...BUT OTHERWISE MONDAY DURING THE DAY IS EXPECTED TO REMAIN DRY FOR THE MOST PART AS THE WARM FRONT SURGES NORTH AND AN OVERALL LACK IN KINEMATIC FORCING OVERTAKES THE AREA. AT THIS TIME THE ONLY REAL THREAT FOR PRECIPITATION DURING THE DAY MONDAY APPEARS AS THOUGH IT WILL RESIDE OVER OUR SOUTHWESTERN CWA DURING THE LATE AFTERNOON AND EVENING HOURS...WHICH IS WHERE AND WHEN GUIDANCE SUGGESTS AN ADVANCING LOW LEVEL DRY LINE WILL BULGE EAST. AN AREA OF LOCALLY ENHANCED CONVERGENCE AND LIFT IN THE VICINITY OF THIS DRY LINE BULGE...WORKING IN CONCERT WITH DIABATIC HEATING...MAY BE ENOUGH TO INITIALIZE ISOLATED SHOWER AND THUNDERSTORM DEVELOPMENT AND AS A RESULT...~20% POPS ARE FORECAST 21Z MONDAY THROUGH 00Z TUESDAY ACROSS OUR SOUTHWEST. SHOULD THUNDERSTORM ACTIVITY BE REALIZED LATE MONDAY AFTERNOON AND/OR EVENING...THEN DEEP LAYER MUCAPE VALUES OF 2000-3000J/KG...ALONG WITH DEEP LAYER BULK SHEAR VALUES OF ~30KTS...WILL BE AVAILABLE FOR UPDRAFT PRODUCTION AND ENHANCEMENT. GIVEN THIS...WILL GO AHEAD AND HIGHLIGHT THE THREAT FOR ISOLATED SEVERE WEATHER ACROSS OUR SOUTHWEST MONDAY AFTERNOON AND EVENING. FINALLY...INCREASING SOUTHERLY FLOW WILL LIKELY BE OBSERVED MONDAY AFTERNOON ONCE THE SURFACE WARM FRONT SURGES NORTH. GUIDANCE SUGGESTS A SUSTAINED WIND OF ~24KTS...WITH HIGHER GUSTS APPROACHING 35KTS...WILL BE REALIZED PRIMARILY ACROSS NORTH CENTRAL KANSAS. AS A RESULT...WILL CONTINUE MENTIONING SUCH CONDITIONS IN THE HWO. LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 317 PM CDT SUN JUN 23 2013 MONDAY NIGHT...A VORT MAX LOCATED OVER THE HIGH PLAINS WILL TRACK EAST ACROSS THE FORECAST AREA. THUNDERSTORMS THAT INITIALLY FORM ACROSS THE HIGH PLAINS DURING THE MONDAY AFTERNOON HOURS WILL SLIDE EAST DURING THE EVENING AND OVERNIGHT HOURS...AND IF THEY HOLD TOGETHER MAY BRING RAIN TO PORTIONS OF THE FORECAST AREA. IN ADDITION TO RAIN...SOME OF THESE THUNDERSTORMS MAY BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS POSSIBLE DURING THE EVENING HOURS. INSTABILITY IS HIGH AND DEEP LAYER SHEAR IS MORE MODEST BUT SUFFICIENT FOR SEVERE STORMS. THE LIMITING FACTOR WILL BE THE WARM MID LEVEL CAP AND THUS CONFIDENCE IN THUNDERSTORM DEVELOPMENT AND COVERAGE IS STILL FAIRLY LOW WITH SLIGHT POPS. THE 12Z ECMWF AND 12Z NAM FAVOR OUR WEST AND NORTH FOR STORMS...WHILE THE 12Z GFS HIGHLIGHTS OUR SOUTHEASTERN ZONES. THE ECMWF AND NAM MAKE MORE SENSE WITH FAVORING NORTH AND WEST ZONES BASED ON THE EXPECTED UPPER WAVE LOCATION AND THE INCREASING STRENGTH OF THE CAP AS YOU HEAD SOUTH. TUESDAY AND WEDNESDAY...THE PATTERN WILL BE FAIRLY ZONAL WITH ALL OF THE BETTER UPPER FLOW AND SHORT WAVES TRACKING ACROSS THE NORTHERN TIER STATES. AN UPPER RIDGE WILL SLOWLY BEGIN TO BUILD ACROSS THE SOUTHWEST CONUS STARTING ON WEDNESDAY. A SFC TROUGH AXIS WILL TRACK EAST THROUGH OUR FORECAST AREA LATE ON TUESDAY AND TURN THE WINDS TO NORTHERLY BY WEDNESDAY. HOWEVER...A STRONG CAP SHOULD RESULT IN DRY CONDITIONS FOR MOST AREAS AND WILL CONTINUE TO CALL FOR A DRY FORECAST...BUT CAN NOT COMPLETELY RULE OUT AN ISOLATED THUNDERSTORM...HENCE THE 10 PERCENT POPS. TUESDAY WILL BE SCORCHER WITH HIGHS WELL INTO THE 90S ACROSS NEBRASKA TO OVER 100 ACROSS MUCH OF NORTHERN KANSAS. TEMPERATURES WILL FALL A FEW DEGREES WITH THE NORTH WINDS ON WEDNESDAY...BUT CONTINUE TO EXPECT 90S FOR HIGHS. THURSDAY THROUGH SUNDAY...THERE IS A SHIFT IN THE UPPER PATTERN AS AN UPPER RIDGE STRENGTHENS ACROSS THE ROCKIES AND AN UPPER TROUGH PERSISTS ACROSS THE EASTERN CONUS. THIS WILL RESULT IN NORTHWESTERLY FLOW ALOFT FOR OUR FORECAST AREA. MOST AREAS WILL BE DRY THROUGHOUT THIS PERIOD GIVEN A LACK OF FORCING. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS ON THURSDAY INTO THURSDAY NIGHT...BUT MOST RESENT MODEL RUNS ARE STARTING TO BACK OFF OF THIS ALREADY RATHER SLIGHT CHANCE OF PRECIPITATION. ANOTHER WEAK COOL FRONT WILL TRY TO WORK ITS WAY THROUGH AT SOME POINT THURSDAY NIGHT OR FRIDAY...BUT THURSDAY SHOULD STILL BE A HOT DAY WITH 90S ACROSS NEBRASKA TO NEAR 100 IN KANSAS. THE COOLER WEATHER WILL SETTLE IN ON FRIDAY AND SATURDAY WITH EASTERLY TO NORTHEASTERLY SFC WINDS. THIS COOLER FETCH SHOULD DROP HIGHS BACK INTO THE LOWER AND MID 90S ON FRIDAY...AND THEN 80S ACROSS NEBRASKA TO LOWER 90S OVER KANSAS ON SATURDAY. TEMPERATURES BEGIN TO WARM BACK UP ON SUNDAY WITH EVERYONE BACK IN THE 90S. OVERALL...TEMPERATURES WILL NOT VARY THAT MUCH AND REMAIN RATHER TOASTY. AVIATION...(FOR THE 06Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 115 AM CDT MON JUN 24 2013 GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. CONVECTION DEVELOPING OFF THE HIGHS PLAINS EARLY TONIGHT WILL SHIFT NEWD AND MAY IMPACT THE GRI TERMINAL AROUND 9-11Z AND WILL INCLUDE A TEMPO GROUP FOR THIS. OTHERWISE SOME MVFR CIGS ARE AROUND THE REGION...BUT WE EXPECT MUCH OF THIS TO LIFT NWD OVERNIGHT BUT SOME MVFR CIGS/VISBY ARE POSSIBLE IN THE TSRA. OTHERWISE SOUTHERLY WINDS WILL INCREASE THROUGH THE DAY ON MON. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1016 AM EDT MON JUN 24 2013 .SYNOPSIS... VERY WARM AND HUMID CONDITIONS WILL REMAIN IN PLACE ACROSS THE REGION FOR THE BULK OF THIS WEEK...BUT UNLIKE THE PAST FEW DAYS WHEN THUNDERSTORMS WERE FEW AND FAR BETWEEN...CONVECTION WILL GRADUALLY BECOME MORE WIDESPREAD. && .NEAR TERM /THROUGH TONIGHT/... 12Z BUF SOUNDING SHOWS MORE INSTABILITY AND PRECIPITABLE WATER COMPARED TO YESTERDAY. IN ADDITION...WILL HAVE TO DEAL WITH UPPER LEVEL TROUGH CLEARLY SEEN IN WATER VAPOR IMAGERY OVER PA MOVING NE. EXPECT CONVECTION TO FIRE ONCE WE CAN GET SOME SURFACE BASED LIFT EARLY THIS AFTERNOON...PROBABLY ALONG A LAKE ERIE BREEZE SIMILAR TO SUNDAY. THIS SHOULD BE ON THE NW OR W SIDE OF THE ABOVE MENTIONED UPPER LEVEL DISTURBANCE. WINDS ALOFT ARE FORECAST TO BE ABOUT 15-20 KTS...ALTHOUGH PRECIPITABLE WATER IS EXPECTED TO BE ON THE DECREASE. THERE WILL BE A THREAT FOR SLOW MOVING STORMS AGAIN TODAY...BUT CONFIDENCE IS NOT HIGH ENOUGH FOR A FLASH FLOOD WATCH. BASED ON MESOSCALE MODEL GUIDANCE /SSEO AND HRRR AND LOCAL MODELS/ THE BIGGEST THREAT APPEARS TO BE WELL INLAND...FINGER LAKES AND/OR CENTRAL NY. WILL KEEP THE WELL THOUGHT OUT LIKELY POPS FROM CONTINUITY FOR THAT REGION. OTHERWISE...EXPECT ANOTHER WARM/HUMID DAY WITH PARTIAL SUNSHINE. WARMING MID LEVELS AND GENERAL SUBSIDENCE WILL BE FOUND IN THE WAKE OF THE EXITING CIRCULATION MONDAY NIGHT. THIS IN COMBINATION WITH THE WEAKENING OF THE DIURNAL INSTABILITY SHOULD LEAD TO ANOTHER FAIR WARM AND HUMID NIGHT...ALTHOUGH CONVECTION IN THE AFOREMENTIONED AREAS WILL STILL BE WANING DURING THE EVENING HOURS. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... ON TUESDAY...YET ANOTHER IN A SERIES OF MID LEVEL SHORTWAVES WILL WORK FROM THE CENTRAL TO LOWER GREAT LAKES IN THE NEARLY ZONAL FLOW ALOFT. WHILE THE 00Z GUIDANCE SUITE CONTINUES TO SHOW SOME DISAGREEMENT IN THE TIMING OF THIS WAVE...A ROUGH MODEL CONSENSUS SUGGESTS THAT THIS FEATURE WILL AT LEAST GET CLOSE ENOUGH TO ACT AS A TRIGGER FOR CONVECTION AT SOME POINT...POTENTIALLY AS EARLY AS TUESDAY MORNING ACROSS FAR WESTERN NEW YORK PER THE MORE CONSISTENT GFS/ECMWF SOLUTIONS. COUPLED WITH DIURNAL HEATING OF OUR VERY WARM AND HUMID AIRMASS AND RESULTANT SBCAPES OF 1000-2000 J/KG...THIS SHOULD RESULT IN ANOTHER ROUND OF AT LEAST SCATTERED CONVECTION AREAWIDE. THE GREATEST AREAL COVERAGE WILL ONCE AGAIN BE MOST LIKELY FROM THE SOUTHERN TIER NORTHEASTWARD ACROSS THE GENESEE VALLEY/ FINGER LAKES TO INTERIOR PORTIONS OF THE NORTH COUNTRY...WHERE LOW LEVEL INSTABILITY WILL BE MAXIMIZED AND LAKE BREEZE BOUNDARIES SHOULD PROVIDE ADDED LOCALIZED LIFT OF THE UNSTABLE AIRMASS. A SLIGHTLY STRONGER MID LEVEL TROPOSPHERIC FLOW COMPARED TO THE PREVIOUS FEW DAYS SHOULD MEAN THAT THERE WILL AT LEAST BE A SOMEWHAT LOWER RISK FOR LOCALIZED HEAVY RAINFALL/FLOODING...HOWEVER THIS MAY ALSO LEAD TO A SOMEWHAT GREATER POTENTIAL FOR A FEW STRONGER STORMS...PARTICULARLY ACROSS THE NORTH COUNTRY AND SAINT LAWRENCE VALLEY WHERE THE OVERALL MID LEVEL FLOW SHOULD BE STRONGEST. DURING THE COURSE OF TUESDAY NIGHT...CONVECTION SHOULD GENERALLY BE ON A DOWNWARD TREND THROUGH MUCH OF THE THE NIGHT...THOUGH THE EXACT SPEED OF THIS DIMINISHING TREND NOW APPEARS TO BE MUCH MORE IN QUESTION COMPARED TO 24 HOURS AGO. OF THE AVAILABLE GUIDANCE...THE ECMWF REMAINS VERY CONSISTENT WITH ITS PREVIOUS RUNS IN ADVECTING A SUBSTANTIAL SURGE OF DRIER AIR ALOFT INTO THE AREA IN THE WAKE OF TUESDAY`S SHORTWAVE AND ITS ATTENDANT WEAK FRONTAL BOUNDARY ...WHICH RESULTS IN CONVECTION QUICKLY DIMINISHING ACROSS THE AREA DURING THE EVENING...FOLLOWED BY MAINLY DRY WEATHER FOR A TIME BEFORE SOME ADDITIONAL UPSTREAM CONVECTION ARRIVES LATER ON IN THE NIGHT. IN CONTRAST...THE GFS/GEM ARE A BIT SLOWER WITH THE DEPARTURE OF SHORTWAVE ENERGY ALOFT...AND CONSEQUENTLY ADVECT ANOTHER ROUND OF UPSTREAM CONVECTION /AND POTENTIALLY AN MCS/ ACROSS THE AREA DURING THE EVENING...FOLLOWED BY DECENT DRYING FROM WEST TO EAST OVERNIGHT. MEANWHILE...THE NAM IS A SUBSTANTIAL OUTLIER IN LINGERING THE AFOREMENTIONED SURFACE FRONT ACROSS THE AREA THROUGH THE NIGHT... WITH ADDITIONAL CONVECTION RIPPLING EAST ALONG AND NORTH OF THIS BOUNDARY RIGHT THROUGH THE NIGHT. THROWING OUT THE 00Z NAM...WHICH IS OUT OF SYNC WITH ALL OF THE OTHER GUIDANCE AND PER EXPERIENCE IS USUALLY NOT AS RELIABLE THIS FAR OUT...WILL AIM MORE CONSERVATIVE AND KEEP AT LEAST A LOW CHANCE OF CONVECTION IN AREAWIDE FOR THE FIRST HALF OF THE NIGHT GIVEN THE AFOREMENTIONED UNCERTAINTIES IN TIMING...FOLLOWED BY A RETURN TO MAINLY DRY CONDITIONS OVERNIGHT FOLLOWING A ECMWF/GFS/GEM CONSENSUS AND OUR PREVIOUS CONTINUITY. ON WEDNESDAY...IT APPEARS TO BE A CASE OF DEJA VU AS THE NEXT AND POTENTIALLY STRONGER SHORTWAVE TROUGH AND ASSOCIATED SURFACE REFLECTION SETTLES ACROSS THE GREAT LAKES...WITH AN ASSOCIATED WARM FRONTAL BOUNDARY DEVELOPING EASTWARD ACROSS THE LOWER GREAT LAKES AND NEW YORK STATE. COUPLED WITH INCREASING DAYTIME INSTABILITY... THIS WILL ONCE AGAIN LEAD TO INCREASING CHANCES OF CONVECTION FROM WEST TO EAST...AGAIN POTENTIALLY BEGINNING EARLY IN THE DAY ACROSS EXTREME FAR WESTERN NEW YORK AS THE LEAD EDGE OF THIS NEXT SYSTEM INTERACTS WITH SOME ELEVATED INSTABILITY. AS SUCH...WILL HAVE BROADBRUSH CHANCE POPS IN PLAY...AND GENERALLY INCREASING FROM WEST TO EAST THROUGH THE COURSE OF THE DAY. WEDNESDAY NIGHT AND THURSDAY...THE AXIS OF THE AFOREMENTIONED SHORTWAVE TROUGH AND MODEST SURFACE WAVE WILL TRANSLATE FURTHER EAST INTO THE LOWER GREAT LAKES AND NEW YORK STATE. THIS WILL LEAD TO A FURTHER UPTICK IN CONVECTIVE CHANCES...PARTICULARLY DURING THE DAY ON THURSDAY WHEN THESE FEATURES WILL MOVE OVERHEAD...AND WILL ONCE AGAIN BE ABLE TO TAKE ADVANTAGE OF INCREASING DIURNAL INSTABILITY. WILL THUS CONTINUE TO INDICATE AN INCREASING TREND IN POPS THROUGH THESE TWO PERIODS...CULMINATING IN A MIX OF HIGH CHANCE TO LOW LIKELY VALUES ON THURSDAY...WITH THE HIGHEST VALUES ACROSS THE NORTH COUNTRY/SAINT LAWRENCE VALLEY...WHICH WILL BE ALONG AND NORTH OF THE TRACK OF THE SURFACE LOW/ATTENDANT WARM FRONT. THURSDAY NIGHT...WILL KEEP BROADBRUSH HIGH CHANCE POPS ACROSS THE REGION AS THE BROAD SURFACE WAVE LINGERS IN PLACE OVERHEAD...AND THE MID LEVEL SHORTWAVE TROUGH BEGINS TO DEEPEN AS IT STARTS TO GET REINFORCED BY ADDITIONAL SHORTWAVE ENERGY DROPPING SOUTHEAST FROM CENTRAL CANADA. AS FOR TEMPERATURES...WARM AND HUMID WEATHER WILL CONTINUE TO BE THE RULE THROUGH THIS PERIOD AS 850 MB TEMPS REMAIN LOCKED IN THE +16C TO +18C RANGE...AND SURFACE DEWPOINTS LINGER IN THE MID TO UPPER 60S. THE WARMEST TEMPS WILL LIKELY OCCUR TUESDAY AND WEDNESDAY WHEN PRECIPITATION/CLOUD COVERAGE WILL BE SOMEWHAT LESS...ALLOWING HIGH TEMPS TO REACH INTO THE MID-UPPER 80S IN MOST PLACES...THOUGH AREAS IMMEDIATELY NORTHEAST OF THE LAKES WILL LIKELY BE SOMEWHAT COOLER DUE TO THE PREVAILING SOUTHWESTERLY LOW LEVEL FLOW. THURSDAY WILL THEN LIKELY BE A LITTLE COOLER AS CONVECTIVE COVERAGE INCREASES... WITH READINGS GENERALLY PEAKING IN THE LOWER TO MID 80S. MEANWHILE...NIGHTTIME PERIODS WILL REMAIN RATHER SULTRY...WITH TEMPS ONLY SETTLING INTO THE 65-70 DEGREE RANGE EACH NIGHT. && .LONG TERM /FRIDAY THROUGH SUNDAY/... DURING THE LONG TERM PERIOD...ROBUST LARGE-SCALE TROUGHING WILL DEVELOP ACROSS OUR REGION AS PLENTIFUL SHORTWAVE ENERGY OVER CENTRAL CANADA DROPS SOUTHEASTWARD INTO THE EXISTING MODEST MID LEVEL TROUGH OVER THE GREAT LAKES...EVENTUALLY CARVING OUT A SUBSTANTIAL UPPER LEVEL TROUGH IN THE PROCESS. THIS WILL RESULT IN CONTINUED UNSETTLED WEATHER RIGHT THROUGH NEXT WEEKEND AS HEIGHT FALLS/COOLING TEMPS ALOFT OVERSPREAD LINGERING WARM AND HUMID AIR IN THE BOUNDARY LAYER. THIS WILL ESPECIALLY BE THE CASE DURING THE DAYLIGHT HOURS OF FRIDAY AND SATURDAY WHEN THE BEST COMBINATIONS OF INSTABILITY... AVAILABLE MOISTURE...AND LARGE-SCALE FORCING WILL BE REALIZED... FOR WHICH HIGH CHANCE TO LOW LIKELY POPS WILL BE IN PLAY. BY SUNDAY...CONVECTIVE POTENTIAL AND COVERAGE SHOULD BEGIN TO LOWER SOMEWHAT AS THE AXIS OF DEEPEST MOISTURE ASSOCIATED WITH THE TROUGH SHIFTS A LITTLE TO OUR EAST...THOUGH SCATTERED SHOWERS AND STORMS WILL REMAIN A DISTINCT POSSIBILITY. OVER TIME...THIS EVOLUTION IN THE PATTERN WILL ALSO LEAD TO A GRADUAL AND MODEST REDUCTION IN TEMPERATURE AND HUMIDITY LEVELS AS SOMEWHAT COOLER/DRIER AIR WORKS INTO OUR REGION...WITH READINGS FALLING BACK TO NORMAL EARLY SUMMER LEVELS BY NEXT WEEKEND. MORE SPECIFICALLY...850 MB TEMPS WILL GRADUALLY SETTLE FROM THE MID TEENS BACK TO THE +12C TO +14C RANGE...AND THIS COUPLED WITH INCREASED CLOUD COVER AND PRECIPITATION WILL RESULT IN DAYTIME HIGHS SLIPPING BACK TO THE UPPER 70S/LOWER 80S FOR FRIDAY AND SATURDAY...AND THE MID AND UPPER 70S BY SUNDAY. MEANWHILE...SURFACE DEWPOINTS WILL DROP BACK TO SOMEWHAT MORE COMFORTABLE LEVELS IN THE UPPER 50S/LOWER 60S. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... WHILE VFR CONDITIONS WILL BE FOUND AT ALL OF THE COMMERCIAL AVIATION SITES THIS AFTERNOON...THERE WILL BE AN INCREASED THREAT FOR CONVECTION. THIS WILL MAINLY BE THE CASE OVER THE SRN TIER AND FINGER LAKES REGION... WHERE SLOW MOVING THUNDERSTORMS THIS AFTERNOON AND EVENING COULD PRODUCE HEAVY RAINS AND POSSIBLY SOME SMALL HAIL. ANY SUCH CONVECTION WILL THEN WEAKEN AND DISSIPATE WITHIN A COUPLE HOURS AFTER SUNSET...LEAVING MAINLY VFR CONDITIONS IN PLACE FOR TONIGHT. OUTLOOK... TUESDAY THROUGH THURSDAY...MAINLY VFR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS. && .MARINE... HIGH PRESSURE WELL OFF THE SOUTHEAST COAST WILL KEEP A RELATIVELY WEAK SFC PRESSURE GRADIENT OVER THE LOWER GREAT LAKES INTO THE MIDDLE OF THE COMING WEEK. THIS WILL RESULT IN LIGHT SOUTH TO SOUTHWEST WINDS ON BOTH LAKES ERIE AND ONTARIO...WITH NEGLIGIBLE WAVES. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...RSH NEAR TERM...RSH/ZAFF SHORT TERM...JJR LONG TERM...JJR AVIATION...RSH/ZAFF MARINE...RSH
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
1006 AM EDT MON JUN 24 2013 .DISCUSSION... VORT MAX ASSOCIATED WITH CONVECTION OVER W KY STILL LOOKS TO BE SLOWLY DRIFTING TOWARD OUR AREA. THE APPROACH OF THIS FEATURE WILL BRING AN INCREASE IN MOISTURE AND HELP TO TRIGGER CONVECTION THIS AFTERNOON. LATEST RUC SOUNDINGS SHOW CAPES GENERALLY RANGING FROM 2000 TO 2500 J/KG BY 18Z. SOME AREAS MAY BECOME SLIGHTLY MORE OR LESS UNSTABLE DEPENDING ON CLOUD COVER. IT STILL LOOKS LIKE AREAS TO THE WEST HAVE GREATER CHANCES OF SEEING CONVECTION...AS LATEST NAM AND RUC MODELS DEVELOP CONVECTION OVER MIDDLE TN AND ADVANCE IT TOWARDS THE PLATEAU. CONVECTIVE COVERAGE SHOULD BE A LITTLE MORE WIDESPREAD THAN THE PAST FEW DAYS AND NOT LIMITED TO ONLY THE HIGHER ELEVATIONS. ALSO...CAN`T RULE OUT AN ISOLATED SEVERE STORM TODAY DUE TO INCREASED INSTABILITY AND MOISTURE...WITH THE MAIN THREAT BEING DAMAGING WINDS. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE DUE TO SLOW STORM MOTIONS OF AROUND 9 KTS. OVERALL...CURRENT FORECAST APPEARS TO BE ON TRACK. NO UPDATES PLANNED AT THIS TIME. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 88 68 90 70 90 / 40 30 30 10 30 KNOXVILLE MCGHEE TYSON AIRPORT, TN 87 67 89 69 90 / 40 30 20 10 30 OAK RIDGE, TN 86 67 89 69 90 / 40 20 20 10 30 TRI CITIES AIRPORT, TN 87 64 88 63 89 / 30 20 30 10 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SR
AREA FORECAST DISCUSSION
NWS SPOKANE WA
444 AM PDT Mon Jun 24 2013 .SYNOPSIS... A wet pattern will continue across the Inland Northwest through mid week...with frequent showers and scattered thunderstorms common. The weather the second half of the week will be dramatically different as a warming and drying trend quickly develops by late week. Summer-like temperatures will be possible by the weekend. && .DISCUSSION... Today and tonight...Offshore low pressure buttressed against interior ridging with an axis positioned over Eastern Montana is allowing a moist and very dynamic southwest flow of moisture and energy to continue to pass through Eastern Washington and Northern Idaho. Negatively tilted shortwaves ejecting up through this flow have enough energy to merit not only high pops and moderate QPF for rain but also the mention of thunderstorms. Recent HRRR model runs hint at once the elevated forced convective showers and thunderstorms pass associated with the largest baroclinic negatively tilted frontal zone passing through right now there will be not so much a break in the activity but a decreasing trend between the time when the elevated convection either exits into Canada or erodes/weakens some along its back trailing edges and the time near 18Z and beyond where surface based convection is expected to start filling in the breaks. Therefore the forecast will remain cluttered with moderate to high pops, QPF, along with some mention of thunderstorms that decreases substantially with loss of daytime heating allowing the surface based convection to subside...especially noted after 6Z tonight. /Pelatti Tues through Fri Nt: This four-day period will be the transition period characterized by wet weather Tue and Wed, then by a rapid warming and drying trend Thurs and Fri. The primary concern will be how much pcpn will fall in the mtn zones of Nrn Wa, the Id Panhandle and the East Slopes of the Cascades. Three-day model guidance QPF is depositing (through about Wed) big ranges anywhere from 0.60-1.50 inches for these zones... with the SREF the least and the GFS the highest amnts. A complicating factor in our pcpn amnt fcst is the number of quick-moving waves that track across the Pac Nw through mid-week. There are at least four subtle features (depending on the model), all of which contain a decent SW moisture tap, with pwat values averaging around one inch. The latest TPW loop shows a nearly SW-to-NE plume of 200% of normal values aimed at Nrn Calif. Our waves should be able to tap into at least 100-150% values. Adding to the complexity of the wide- ranging rainfall amnts is the element of instability, especially late afternoon. This will be the dominating factor that will produce wide-ranging rainfall amnts over very short distances. Streams that will be affected most will be those across NE WA and the N Id Panhandle...especially where the recent heavy pcpn fell the last couple weeks...as well as the Stehekin River near the Cascade crest.bz Saturday through Monday...A ridge of high pressure will build north near the Inland Northwest, bringing with it drying conditions and above normal temperatures. The extended models are consistent in building a ridge into the region, but how amplified the ridge is and its placement are still in question. The difference is forecasting temperatures in the 90s to temperatures a little "cooler" in the 80s. Previous forecasts had lowered temperatures a tad on Saturday and did not see any reason to deviate from this. Until a little better consistency occurs, the forecast will trend to the ridge building into eastern Washington and the Idaho panhandle a little more each day, and thus warming temperatures a few degrees each day. Precipitation chances remain near nil, except for early Saturday where a lingering shower or thunderstorm may occur over Idaho panhandle. ty && .AVIATION... 12Z TAFS: Negatively tilted trof passage keeps aviation area wet and unsettled today with MVFR ceilings at most TAF sites. Some improvement as far as decreasing showers and raising of ceilings expected after 03Z Tuesday. /Pelatti && .PRELIMINARY POINT TEMPS/POPS... Spokane 67 53 66 52 73 54 / 90 80 80 50 20 10 Coeur d`Alene 66 55 66 52 73 53 / 100 80 80 50 20 20 Pullman 66 52 66 51 74 52 / 70 60 70 50 20 10 Lewiston 71 57 74 57 80 58 / 70 60 60 60 30 20 Colville 71 54 70 51 75 52 / 100 70 80 60 20 20 Sandpoint 66 54 67 51 71 52 / 100 80 90 60 30 20 Kellogg 63 52 63 51 69 52 / 80 80 80 50 30 20 Moses Lake 74 58 69 56 80 58 / 50 30 50 20 20 10 Wenatchee 74 57 69 57 79 60 / 50 30 50 20 20 10 Omak 73 56 70 53 77 54 / 70 50 60 30 20 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
702 AM CDT MON JUN 24 2013 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 415 AM CDT MON JUN 24 2013 06Z DATA ANALYSIS HAD LOW PRESSURE OVER LK WINNIPEG AND OVER THE OK/TX PANHANDLE AREA...WITH A WEAK RIDGE OF HIGH PRESSURE IN BETWEEN ACROSS SD TO IA. FRONTAL BOUNDARY/TROUGH FROM THE TX/OK LOW WAS ACROSS KS TO NORTHERN MO. WARM/MOISTURE ADVECTION/THETA-E CONVERGENCE OVER THIS BOUNDARY FOCUSED FROM EASTERN CO TO SOUTHERN IA...WHERE CONVECTION WAS FIRING EARLY THIS MORNING. THE FCST AREA AND REST OF WI/MN GETTING A NEEDED BREAK FROM THE SHRA/TSRA SO FAR SUNDAY THRU THIS MORNING...BEING NORTH/EAST OF THE SFC-700MB RIDGE AXIS. INITIALIZATIONS OF 24.00Z MODELS BETTER THAN THE PAST COUPLE 00Z CYCLES...THIS EXCEPT FOR THE GFS TOO HIGH ON SFC DEW POINTS OVER MUCH OF THE MID/UPPER MS VALLEY. EVEN WITH TIGHTER/BETTER INITIALIZATIONS...SOLUTIONS CONTINUE TO HAVE MESO-SCALE DIFFERENCES WHICH IMPACT THE SENSIBLE WEATHER IN THE SHORT TERM. DPROG/DT OF 500MB HGTS AT 24.00Z SHOWED THE MODEL RUNS OF 22.00Z AND 23.00Z VERIFIED WELL ACROSS NOAM/EASTERN PAC...FAVORING STRONGER OF EARLIER RUNS WITH THE TROUGH/ENERGY NEAR LK WINNIPEG AND THE TROUGHING OVER CA. MODEL CONSENSUS REMAINS GOOD WITH THE LARGER SCALE FEATURES TODAY THRU TUE BUT PLENTY OF DETAIL DIFFERENCES REMAIN WITH THE WEAKER SHORTWAVES THRU THE SOUTHWEST FLOW OVER THE CENTRAL CONUS. GENERAL TREND IS A LITTLE FLATTER WITH THE CENTRAL CONUS RIDGING AND STRONGER WITH UNIDENTIFIABLE SHORTWAVE FEATURES. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED ALL TO BE REASONABLE WITH THE SFC MASS FIELDS OVER THE CENTRAL CONUS. PER WV IMAGERY MODELS LOOKED GOOD WITH THE LARGER SHORTWAVES OVER NOAM...WHILE STRUGGLING WITH WHAT LOOKED TO BE A WEAK SHORTWAVE AIDING THE NEB/CO/KS CONVECTION. AS HAS BEEN THE CASE THE PAST FEW DAYS...MODELS HAVING DIFFICULTIES WITH CONVECTION OVER THE CENTRAL CONUS. CLOSEST WITH THE 00-06Z PRECIP LOOKED TO BE THE GFS AND THE HRRR WRF MODEL. NO ONE CLEAR FAVORITE. WITH ALL THE MODEL SCENARIOS ON HOW CONVECTION PLAYS OUT THE NEXT 48-72HRS AND MOST MODELS CONTINUING TO STRUGGLE WITH THAT EARLY THIS MORNING...SHORT-TERM CONFIDENCE REMAINS BELOW AVERAGE. FORECAST TODAY/TONIGHT HINGES ON WHERE THE KS/NORTHERN MO BOUNDARY ENDS UP. MODEL CONSENSUS LIFTS THIS BOUNDARY...AND ITS FOCUS FOR FORCING/LIFT/CONVECTION INITIATION...SLOWLY NORTH TODAY/TONIGHT... TO SOUTHWEST MN TO EASTERN IA/NORTHWEST IL BY 12Z TUE. MOISTURE TRANSPORT/THETA-E CONVERGENCE ON NOSE OF THE 850MB JET ALREADY FIRING THE CONVECTION OVER IA...WITH THIS TRANSLATING EAST/NORTHEAST TOWARD AND INTO THE SOUTHEAST END OF THE FCST AREA. WILL EXTEND THE FLASH FLOOD WATCH FOR THE SOUTHEAST END OF THE FCST AREA THRU THE MORNING. LOW LEVEL MOISTURE TRANSPORT/THETA-E CONVERGENCE CONTINUES TO INCREASE OVER THE FRONT AND TOWARD THE AREA TODAY AS LOW PRESSURE LIFTS INTO NEB. GENERAL MODEL CONSENSUS FOR CONVECTION TO SLOWLY BUILD WEST/SOUTH OF THE FCST AREA THIS MORNING THE LIFT INTO THE AREA THIS AFTERNOON. PER THE HRRR...PART OF THIS IS THE COMPLEX MOVING ACROSS NEB EARLY THIS MORNING. LEANING TOWARD THE HRRR WHICH HAS BEEN DOING A DECENT JOB WITH THE CO/NEB CONVECTION AND THAT ACROSS IA...THE NEB CONVECTION GROWS ONCE IT REACHES STRONGER/RICHER MOISTURE TRANSPORT OVER EASTERN NEB/WESTERN IA. SOME FORM OF CONVECTIVE COMPLEX THEN HEADS TOWARD THE FCST AREA FOR THE AFTERNOON. LOW LEVEL THERMODYNAMIC FORCING STRENGTHENS INTO THE AREA TONIGHT ALONG WITH THE MOISTURE TRANSPORT AS THE FRONT SLOWLY LIFTS NORTH. RAISED SHRA/TSRA CHANCES INTO THE 60-70 PERCENT RANGE FOR TONIGHT INTO TUE MORNING. ANY TSRA WILL REMAIN EFFICIENT RAIN MAKERS WITH PW VALUES IN THE 1.5 TO 1.75 INCH RANGE...ML CAPES OF 2K-3K J/KG AND WARM CLOUD DEPTHS OF 3.5 TO 4KM. WITH MANY AREAS WATERLOGGED AND HAVING ONGOING FLOODING ISSUES...WILL EXPAND THE FLASH FLOOD WATCH TO COVER ALL BUT CLARK/TAYLOR COUNTIES FOR THIS AFTERNOON THRU MID MORNING TUE. FORCING SIGNALS GET A LITTLE MORE MUDDIED TUE. THIS NOT UNEXPECTED DUE TO POTENTIAL DIFFERENT OUTCOMES WITH CONVECTION OVER THE UPPER MIDWEST TONIGHT. APPEARS THE FRONT WILL REMAIN SOUTH OF THE FCST AREA WITH THE 925-850MB FLOW CONTINUING TO PUSH/LIFT MOISTURE NORTHWARD OVER IT. CONTINUED 40-60 PERCENT SHRA/TSRA CHANCES OVER MUCH OF THE FCST AREA TUE. MAY NEED TO EXTEND THE FLASH FLOOD WATCH THRU TUE INTO TUE NIGHT...BUT WILL DEAL WITH THAT ONCE WE GET PAST TONIGHT. ON TOP OF THE HEAVY RAIN CONCERNS...A FEW OF THE TSRA COULD BE SEVERE THIS AFTERNOON/EVENING AND AGAIN TUE INTO TUE EVENING DUE TO THE STRONG INSTABILITY...INCREASE OF THE 0-6KM SHEAR AND POTENTIAL FOR TSRA TO ORGANIZE INTO COMPLEXES WITH STRONG COLD POOLS. SEE SWODY1 AND SWODY2 FOR MORE DETAILS. USED A BLEND OF THE NUMERICAL TEMP GUIDANCE FOR HIGHS/LOWS FOR TODAY THRU TUE. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 415 AM CDT MON JUN 24 2013 FOR TUE NIGHT THRU WED NIGHT MODELS SHOW THE REMNANTS OF THE TROUGHING NOW OVER CA WILL LIFT INTO AND ACROSS THE UPPER MIDWEST. TREND CONTINUES TO FAVOR STRONGER OF THE EARLIER RUNS. WITH THIS BEING A LARGER SCALE FEATURE AND THE DECENT MODEL CONSISTENCY FCST CONFIDENCE FOR THIS PERIOD IS AVERAGE. AS THE STRONGER MID LEVEL TROUGH MOVES INTO THE UPPER MIDWEST TUE NIGHT THE PLAINS SFC LOW MOVES INTO MN/WI. LOWER LEVEL THERMO DYNAMIC FORCING/LIFT AND MOISTURE TRANSPORT REMAINS STRONG INTO THE AREA AHEAD OF THESE FEATURES. WHERE THE FRONT AHEAD OF THE LOW FROM TODAY/TUE ENDS UP WILL DETERMINE WHERE THE STRONGER LIFT WILL BE. MODEL CONSENSUS HAS IT SOMEWHERE OVER THE FCST AREA TUE NIGHT... THUS CARRIED HIGHEST SHRA/TSRA CHANCES IN THE 60-70 PERCENT RANGE OVER THE NORTHEAST 2/3 OF THE FCST AREA. PW VALUES REMAIN IN THE 1.5 TO 1.75 INCH RANGE WITH ANY STORMS CAPABLE OF PRODUCING HEAVY RAINS. AGAIN...WILL LIKELY NEED MORE FLASH FLOOD WATCHES FOR PORTIONS OF THE AREA INTO TUE NIGHT WITH POTENTIAL FOR ANOTHER 0.5 TO 1.5 INCHES...LOCALLY MORE...OF RAIN. ONCE THIS STRONGER MID LEVEL TROUGH PASSES TUE NIGHT/WED MORNING THE FLOW PATTERN OVER NOAM BEGINS TO CHANGE WITH RIDGING BUILDING OVER THE WESTERN CONUS AND INCREASING NORTHWEST FLOW ALOFT OVER THE UPPER MIDWEST. DRIER AIR AND HIGH PRESSURE WILL SLOWLY SPREAD INTO MN/IA/WI WED/WED NIGHT. SHRA/TSRA CHANCES WILL LINGER WED WITH THE SFC LOW-MID LEVEL TROUGH OVER THE REGION. SHRA/TSRA CHANCES DECREASE WED NIGHT AS HGTS RISE AND THE SFC-MID LEVEL LOW/TROUGH MOVE EAST OF THE AREA. DUE TO THE CONVECTION DETAIL UNCERTAINTIES...CONTINUED TO USE THE MODEL/ENSEMBLE CONSENSUS FOR LOWS/HIGHS IN THE TUE NIGHT TO WED NIGHT PERIOD. ONCE AGAIN NOT A LOT OF TIME SPENT LOOKING AT THE DAY 4-7 PERIOD. 24.00Z MEDIUM RANGE MODELS MAINTAIN A GOOD CONSENSUS FOR THE BUILDING WESTERN NOAM RIDGING AND EASTERN NOAM TROUGHING IN THE THU- SUN PERIOD...WHICH PUTS THE REGION UNDER INCREASING NORTHWEST FLOW ALOFT. THU-SUN SHAPING UP TO BE A DRIER PERIOD WITH TEMPERATURES COOLING TO NEAR OR A BIT BELOW NORMAL. FCST CONFIDENCE FOR THIS PERIOD LOOKS TO BE AVERAGE TO GOOD. DRIER HIGH PRESSURE BUILDS IN FOR THU-SUN...BUT PLENTY OF RESIDUAL LOW LEVEL MOISTURE AND MAXIMUM EVAPO-TRANSPIRATION FROM WELL WATERED VEGETATION AND WET SOILS APPEAR TO REMAIN...ALONG WITH STEEP LOW/ MID LEVEL LAPSE RATES AND SHORTWAVES RIPPLING THRU THE NORTHWEST FLOW ALOFT. THU-SUN TRENDING TO BE DRY DAYS BUT SOME SMALLER MAINLY DIURNAL SHRA/TSRA CHANCES TO PERSIST...AIDED BY THE PASSING SHORTWAVES FROM TIME TO TIME. MODEL/ENSEMBLE CONSENSUS FOR HIGHS/ LOWS IN THE DAY 4-7 PERIOD LOOK WELL TRENDED FOR NOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 702 AM CDT MON JUN 24 2013 SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE REGION LATE THIS AFTERNOON AS A WARM FRONT LIFTS INTO NORTHERN IOWA/SOUTHERN WISCONSIN. PLAN ON SHOWERS AND STORMS IMPACTING THE TAF SITES THROUGH THE EVENING HOURS INTO EARLY TUESDAY MORNING. THE RAIN MAY BECOME HEAVY AT TIMES. A FEW THUNDERSTORMS MAY PRODUCE GUSTY WINDS...ESPECIALLY LATE THIS AFTERNOON INTO THE EVENING HOURS. VISIBILITIES WILL BE REDUCED TO 3SM IN THE HEAVIER THUNDERSTORMS. OTHERWISE...PLAN ON VFR/MVFR CONDITIONS BEFORE THE STORMS MOVE IN WITH CLOUD BASES IN THE 3000 TO 4000 FT RANGE. && .HYDROLOGY... ISSUED AT 415 AM CDT MON JUN 24 2013 THE THREAT FOR HEAVY RAINS CONTINUES/RETURNS TODAY AS YET ANOTHER LOW LIFTS INTO THE CENTRAL PLAINS AND MOISTURE TRANSPORT INCREASES INTO THE AREA. A FRONT SLOWLY LIFTING NORTH FROM KS/NORTHERN MO WILL BE THE FOCUS FOR LIFT AND GENERATING TSRA TODAY/TONIGHT/TUE. THIS BOUNDARY EXPECTED TO REMAIN SOUTH OF THE AREA THRU TUE...WITH THE ZONE OF STRONGER LIFT REMAINING CLOSE TO OR OVER THE FCST AREA. THUNDERSTORMS WILL CONTINUE TO BE EFFICIENT RAIN PRODUCERS. RAINFALL AMOUNTS THIS AFTERNOON AND TONIGHT COULD RANGE FROM 0.50 TO 1.50 INCHES...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. SINCE MUCH OF THE AREA HAS SEEN ANYWHERE FROM 2 TO 10 INCHES DURING THE LAST 3 TO 4 DAYS...IT WILL NOT TAKE MUCH RAIN TO PRODUCE MORE FLOODING PROBLEMS. ADDITION FLASH FLOODING IS QUITE POSSIBLE ACROSS PARTS OF THE FORECAST AREA TODAY THRU TUE NIGHT. HOWEVER THERE CONTINUES TO BE MUCH UNCERTAINTY ON WHERE THIS RAIN MAY FALL. CONTINUED THE FLASH FLOOD WATCH FOR THE SOUTHEAST END OF THE FCST AREA THIS MORNING THEN ISSUED A BROADER FLASH FLOOD WATCH FOR ALL BUT CLARK/TAYLOR COUNTIES THIS AFTERNOON THROUGH MID MORNING TUE. APPEARS ANOTHER ROUND OF WIDESPREAD CONVECTION IS POSSIBLE TUE NIGHT/WED MORNING AND ADDITIONAL FLASH FLOOD WATCHES ARE LIKELY FOR THOSE PERIODS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING FOR WIZ032>034-041>044-053. FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ054-055-061. MN...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING FOR MNZ079-086>088-094>096. IA...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING FOR IAZ008>010-018-019. FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR IAZ011-029-030. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION...WETENKAMP HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
649 AM CDT MON JUN 24 2013 UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND TUESDAY ISSUED AT 444 AM CDT MON JUN 24 2013 THE CONTINUING SAGA ON WHERE AND WHEN FOR CONVECTION CONTINUES THIS MORNING. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY HINT AT WEAK BOUNDARY OVER NORTHEAST WI SEEN IN DEW POINTS. AREA OF DISORGANIZED TSTMS MOVING NORTH THROUGH IA AND WESTERN IL. STARTING TO SEE MORE MOVEMENT TO EAST OVER IL IN LATEST SCANS WHICH WOULD GO WITH MODELS PROJECTION OF LLVL JET SHIFTING MORE TO THE WEST AND WEAKENING BY 12Z. HRRR SEEMS TO HAVE BEST HANDLE ON CURRENT TRENDS...SHOWING ONLY SPOTTY CONVECTION OVER CWA TODAY MAINLY OVER THE SOUTH HALF. ALL MODELS STILL SHOWING VARIETY OF SOLUTIONS IN QPF PATTERN THROUGH THIS PERIOD. HAVE TRENDED TOWARD NAM TODAY GIVEN DRIER AIR WORKING IN AS SEEN IN SIG DROP IN PWATS ON MSP SOUNDING LAST EVENING. SFC BASED INSTABILITY STILL SIG 1-2K...THOUGH NOT SEEING ANY REAL TRIGGER/LIFT TODAY. WENT WITH SLIGHTS FOR LATE DAY CONVECTION SOUTH AND EAST ALONG LAKE BREEZE BOUNDARY. FORCING AND MOISTURE WORKS BACK INTO THE AREA THIS EVENING WITH STRENGTHENING LLVL FLOW POINTING INTO SOUTHWEST WI AFTER 06Z. ALSO SEEING SOME SUPPORT FROM RRQ OF JET MAX MOVING THROUGH LAKE SUPERIOR REGION. WILL GO WITH INCREASING CHANCE POPS TONIGHT HIGH CHANCE POPS TUE AS FGEN/ISENTROPIC LIFT MAXIMIZED OVER CWA FROM 12Z TO 18Z TUES. CWA REMAINS IN SLIGHT RISK AREA ON TUE. SHEAR BETTER SOUTH FOR SOME WIND CONCERNS. WBZERO HGTS RATHER HIGH FOR LARGE HAIL. WITH PWATS RETURNING TO 1.5 TO 2 INCHES AGAIN HEAVY RAIN MORE OF CONCERN. .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY ISSUED AT 444 AM CDT MON JUN 24 2013 500MB RIDGE EXPECTED TO BUILD ACROSS THE WESTERN UNITED STATES WHILE UPPER TROUGH DEEPENS AND POSSIBLY CLOSES OFF ACROSS THE WESTERN GREAT LAKES BY THE END OF THE WORK WEEK INTO NEXT WEEKEND. FORECAST ISSUES ALREADY AT THE START OF THE PERIOD TUESDAY NIGHT. HAVE CONCERNS ON THE PLACEMENT OF CONVECTION TUESDAY EVENING ACROSS NORTHERN WISCONSIN. BELIEF IS THAT THE AXIS OF HEAVIER PRECIPITATION TOO FAR NORTH. THINK BAND WILL BE FURTHER SOUTH AS FIRST COMPLEX OF STORMS LATE MONDAY NIGHT AND TUESDAY WILL PUSH AN OUTFLOW BOUNDARY SOUTHWARD THAN WHAT THE MODELS SHOW...SIMILAR TOO WHAT HAPPENED A FEW DAYS AGO. GFS QPF FIELD SEEMS REASONABLE BASED ON MY CURRENT THINKING. THIS COULD AFFECT THE RAIN CHANCES ACROSS THE NORTH TUESDAY EVENING. SOUTHERN SECTIONS OF THE FORECAST AREA WILL BE CLOSE ENOUGH TO STILL WARRANT LIKELY CHANCES. 500MB TROUGH SWINGS INTO THE AREA TOWARDS 12Z WEDNESDAY...WARRANTING LIKELY POPS EVEN ACROSS THE NORTH. UPPER TROUGH WILL SWING ACROSS THE AREA ON WEDNESDAY. RAISED POPS TO 50 TO 55 PERCENT...AND MAY BUMP THEM UP A LITTLE MORE BEFORE FORECAST ISSUANCE. THE UPPER TROUGH SHOULD SWING EAST INTO LOWER MICHIGAN WEDNESDAY NIGHT. THERE WILL STILL BE SOME LINGERING EVENING SHOWERS AND A FEW STORMS. MID LEVEL LAPSE RATES NOT IMPRESSIVE...THEREFORE ONLY EXPECTED ISOLATED NATURE OF ANY THUNDERSTORMS WEDNESDAY EVENING. NORTHWEST FLOW ALOFT WILL CONTINUE THURSDAY AND FRIDAY...ALTHOUGH A DEEPER 500MB TROUGH WILL SWING ACROSS THE AREA FRIDAY AFTERNOON AND FRIDAY NIGHT. WILL CONTINUE THE SMALL CHANCES FOR SHOWERS SATURDAY... BUT NOT TOO OPTIMISTIC WE WOULD SEE THEM AT THIS TIME SINCE UPPER TROUGH WILL WELL EAST OF THE AREA WITH BUILDING HEIGHTS. CANADIAN HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN ON SUNDAY...ALTHOUGH COULD NOT RULE OUT A FEW ISOLATED SHOWERS SUNDAY AFTERNOON. FOR THE MOST PART...VERIFICATION DATA HAS SHOWN WE AND NUMERICAL GUIDANCE HAS BEEN TOO WARM OF LATE. DID NUDGE TEMPERATURES DOWN A DEGREE OR TWO MOST PERIODS. WILL NEED TO WATCH WEDNESDAY...IF IT STAYS CLOUDY AND THERE IS A LOT OF RAIN AROUND DURING THE DAY... TEMPERATURES COULD STAY IN THE 70S. && .AVIATION...FOR 12Z TAF ISSUANCE ISSUED AT 641 AM CDT MON JUN 24 2013 WILL CONTINUE TO DEAL WITH WHEN AND WHERE SHOWERS AND THUNDERSTORMS WILL BREAK OUT. WESTERLY FLOW AND DRIER AIR ALOFT WILL EXPECTED TO LEAD TO MOSTLY DRY DAY...THOUGH STILL RATHER HUMID AND UNSTABLE AT LOW LEVELS SO MAY SEE POSSIBLE CONVECTIVE DEVELOPMENT ALONG ANY WEAK BOUNDARIES DURING THE AFTERNOON LIKE LAKE BREEZE BOUNDARY. BEST ESTIMATE RIGHT NOW IS THAT SOME CONVECTION WILL FIRE MONDAY NIGHT...AS A UPPER DISTURBANCE TRACKS THROUGH THE AREA AND A SOUTHWESTERLY LOW-LEVEL JET REDEVELOPS. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....TE LONG TERM......ECKBERG AVIATION.......TE
AREA FORECAST DISCUSSION
NWS ALBANY NY
450 PM EDT MON JUN 24 2013 .SYNOPSIS... VERY WARM AND HUMID CONDITIONS WILL CONTINUE EARLY THIS WEEK WITH THE THREAT OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EVENING HOURS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL. OUR NIGHTS WILL BE CONTINUE TO BE MUGGY WITH PATCHY FOG. MORE PERSISTENT CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED LATER IN THE WEEK INTO THE WEEKEND AS A SLOW MOVING LOW PRESSURE SYSTEM IMPACTS THE REGION. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 955 AM...ANOTHER HAZY...HOT AND HUMID DAY SHAPING UP. 12Z ALY SOUNDING SHOWS PLENTY OF ENERGY FOR AFTERNOON THUNDERSTORMS. WATER VAPOR LOOP SHOWS CLOSED LOW SPINNING OVER WESTERN PENNSYLVANIA. THIS UPPER LEVEL LOW IS EXPECTED TO MOVE OVER THE SOUTHERN PART OF THE ALBANY FORECAST AREA OVER THE NEXT 12-18 HOURS AND SHOULD BE A FOCUS FOR STORMS. PWAT ON 12Z ALY SOUNDING WAS 1.77 INCHES SO COPIOUS MOISTURE FOR HEAVY RAINERS. PIT 12Z SOUNDING...UNDER UPPER LEVEL LOW...HAS STEEPER LAPSE RATES. 12Z HRRR SHOWING A MORE WIDESPREAD THREAT OF AFTERNOON STORMS. WILL HAVE TO MONITOR FOR LATER FLASH FLOOD WATCH IF LARGE AREA OF HEAVY RAIN DEVELOPS. COULD BE AN EXCITING DAY... PREVIOUS... THE RIDGE WILL WEAKEN A TAD TODAY AS THE REMNANTS OF THE UPPER LOW FROM OVER THE TENNESSEE VALLEY MOVES EASTWARD. THIS WILL BE THE MAIN FEATURE TRIGGERING CONVECTION ACROSS THE AREA TODAY AND IT WILL ACCOMPANY THE HEATING OF THE DAY. MODEL GUIDANCE SUGGESTS CAPE VALUES OF PEAKING AT 1000-2000 J/KG WITH DEW POINTS IN THE MID TO UPPER 60S. LAPSE RATE OF 6 TO 6.5 C/KM ARE EXPECTED THIS AFTERNOON WITH THE GFS INDICATING 7 C/KM POSSIBLE. MEAN FLOW IS RATHER WEAK AT 15 TO 20 KNOTS SO STORMS WILL MOVE RATHER SLOWLY AND CONVECTION WILL BE LOOSELY ORGANIZED. THE STORM PREDICTION CENTER HAS THE AREA/REGION IN THE GENERAL THUNDERSTORM OUTLOOK FOR TODAY AND TONIGHT. FREEZING LEVEL IS HIGH JUST OVER 14000 FEET ON THE 00Z/MON ALY SOUNDING...SO SOME STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL. THIS ALONG WITH THE RATHER SLOW MOVEMENT HAVE ADDED ENHANCED WORDING OF HEAVY RAINFALL TO THE FORECAST AND WILL KEEP MENTION IN THE HAZARDOUS WEATHER OUTLOOK. CONVECTION IS EXPECTED TO DIMINISH THIS EVENING AS THE WEAKENING UPPER LOW/TROUGH MOVES OFF TO THE EAST AND WITH THE LOSS OF DAYTIME HEATING. LOOKING AT TEMPERATURES IN THE 80S WITH AROUND 90 DEGREES UP THE HUDSON VALLEY INTO CAPITAL DISTRICT. DEW POINTS WILL BE IN THE MID TO UPPER 60S MAKING IT FELL EVEN HOTTER. HEAT INDICES SHOULD REACH THE MID 90S UP THE HUDSON RIVER VALLEY. ANOTHER MUGGY NIGHT WITH LOWS AND DEW POINTS IN THE 60S. WINDS WILL BECOME LIGHT TO CALM WINDS. HAVE ADDED PATCHY FOG MAINLY IN THE RIVER VALLEY LOCATIONS. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... BY TUESDAY MORNING FLOW WILL BECOME NEARLY ZONAL ACROSS THE REGION. A WEAKENING SURFACE LOW AND MID LEVEL SHORT WAVE TROUGH WILL MOVE EASTWARD ACROSS SOUTHERN CANADA PASSING WELL TO OUR NORTH TUESDAY. PLUS GUIDANCE INDICATES SMALL PIECES OF ENERGY SHOULD MOVE THROUGH THE FLOW FARTHER SOUTH ACROSS OUR REGION.ALL THIS LEADS TO ANOTHER ROUND OF CONVECTION MAINLY DURING THE AFTERNOON AND EVENING HOURS TUESDAY WITH THE HEATING OF THE DAY. THE BETTER DYNAMICS AND SHEAR WILL BE ACROSS NORTHERN NEW YORK INTO NORTHERN NEW ENGLAND AND THIS IS WHERE THE STORM PREDICTION CENTER HAS GONE WITH A SLIGHT RISK FOR SEVERE THUNDERSTORMS. FARTHER SOUTH ACROSS OUR FORECAST AREA MEAN FLOW WILL STILL BE RATHER WEAK AROUND 20 KNOTS. IT WILL BE ANOTHER HOT DAY SIMILAR TO MONDAY IN TEMPERATURES AND HEAT INDICES. A WEAK FRONTAL BOUNDARY WILL BE BROUGHT SOUTHWARD INTO THE REGION TUESDAY NIGHT...HOWEVER DUE TO THE FLOW ALOFT THE BOUNDARY WILL STALL ACROSS THE REGION. A MORE VIGOROUS SHORT WAVE WILL MOVE INTO THE LONGWAVE TROUGH OVER THE GREAT LAKES REGION WEDNESDAY AND WEDNESDAY NIGHT AND HEIGHTS WILL BEGIN TO FALL. CHANCES FOR CONVECTION WILL NOT BE LIMITED MAINLY TO THE AFTERNOON AND EVENING HOURS THIS TIME. AS HEIGHTS CONTINUE TO FALL WILL HAVE LARGE SCALE ASCENT THE BOUNDARY WILL BEGIN TO MOVE BACK NORTHWARD AS A WARM FRONT. PRECIPITABLE WATER VALUES WILL STILL BE HIGH SO LOCALLY HEAVY RAINFALL IS EXPECTED WITH SOME STORMS...SO HAVE MENTIONED IN OUR HAZARDOUS WEATHER OUTLOOK. && .LONG TERM /THURSDAY THROUGH MONDAY/... AN UNSETTLED AND WET EXTENDED FORECAST IS LIKELY ACROSS NY AND NEW ENGLAND WITH PERSISTENT CHANCES OF SHOWERS AND THUNDERSTORMS...AS A MID AND UPPER LEVEL TROUGH WILL INITIALLY IMPACT THE REGION TO CLOSE THE WEEK...AND THEN IT MAY CLOSE OR CUT OFF NEAR THE GREAT LAKES REGION AND SRN ONTARIO FOR THE WEEKEND. THE LATEST GFS/ECMWF/CANADIAN GGEM/ENSEMBLE GUIDANCE AND HPC GRAPHICS ARE IN PRETTY GOOD AGREEMENT FOR AN ACTIVE STRETCH OF WEATHER. THEIR ARE SOME SUBTLE DIFFERENCES FOR THE TIMING OF THE SHORT-WAVE IMPULSE ROTATING THROUGH THE UPPER LEVEL TROUGH...BUT ALL AN ALL...IT IS EXTREMELY DIFFICULT TO FIND A SUSTAINED DRY STRETCH OF WX TO CLOSE JUNE. THU-FRI...A WAVE OF LOW PRESSURE APPROACHES THE FCST AREA FROM THE GREAT LAKES REGION WITH SOME OVER RUNNING SHOWERS AND THUNDERSTORMS AHEAD OF A WARM FRONT. THE WARM FRONT MAY BUST THROUGH PORTIONS OF THE FCST AREA FOR A POTENTIAL OF STRONG THUNDERSTORMS...IF HEATING IS REALIZED. THE DETAILS ARE NEBULOUS AND MURKY...SO WE WILL CALL IT A CHANCE OF SHOWERS AND THUNDERSTORMS...THU INTO THU NIGHT. A S/SW H850 LLJ OF 30-45 KTS WILL TRANSPORT IN SOME GULF MOISTURE...AND PWATS WILL CONTINUE TO RUN ABOVE NORMAL. THE SFC LOW BEGINS TO OCCLUDE AND CLOSE OFF JUST NORTHWEST OF LAKE ONTARIO AND NRN NY ON FRI. THE GFS CONTINUES TO PAINT MODERATE AMOUNTS OF INSTABILITY FOR THE POTENTIAL OF SHOWERS AND THUNDERSTORMS AGAIN. THE SUBTROPICAL HIGH REMAINS ANCHORED DOWNSTREAM CONTINUING A DEEP S/SW FETCH OF MOISTURE. THIS LONG DURATION STRETCH OF WX...BEGINS TO MATERIALIZE INTO POTENTIALLY A CLASSIC GREAT LAKES CSTAR CUTOFF LOW WARM SEASON EVENT. TEMPS LOOK TO RUN SLIGHTLY BELOW TO NEAR NORMAL FOR THE THESE DAYS WITH HIGHS IN THE M70S TO L80S AND LOWS IN THE U50S TO 60S. SAT-MON...THE LONGWAVE TROUGH BEGINS TO AMPLIFY WITH THE EMBEDDED 500 HPA CLOSED CIRCULATIONS OVER THE CNTRL AND ERN GREAT LAKES. A COLD FRONT BEGINS TO STALL OUT NEAR THE ERN CONUS SEABOARD. MULTIPLE SHORT-WAVES LIFT NORTHWARD ON THE EAST SIDE OF TROUGH. PERSISTENT BANDS OF SHOWERS AND THUNDERSTORMS TIMED TO THE DIURNAL HEATING AND THE PROPAGATION OF THE IMPULSES ARE POSSIBLE FOR THE WEEKEND INTO EARLY NEXT WEEK. THEIR IS A SMALL POSSIBILITY THAT DRYING IN THE WAKE OF DISTURBANCES MAY PROMOTE MINI DRY STRETCHES. AGAIN...THIS APPEARS TO FIT A GREAT LAKES WARM SEASON CSTAR CLOSED/CUTOFF SCENARIO FOR AN EXTENDED PERIOD OF SHOWERS AND THUNDERSTORMS. THE WEEKEND IS DOMINATED BY A POSITIVE TILT SCENARIO...PERHAPS SHIFTING NEUTRAL BY EARLY NEXT WEEK. H850 TEMPS CONTINUE TO BE IN THE +14C TO +16C RANGE WITH LIMITED HEATING EACH DAY WITH A RESIDUAL COLD POOL ALOFT...AND THE ACTIVE S/SW FLOW. EXPECT HIGHS TO CONTINUE IN THE 70S TO L80S WITH LOWS IN THE U50S TO 60S. TOO EARLY TO PINPOINT LOCATIONS...BUT SOME HYDRO PROBLEMS COULD MATERIALIZE...IF LOCATIONS GET REPEATEDLY HIT BY BANDS OF SHOWERS AND THUNDERSTORMS. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... AS OF 445 PM EDT...MOST OF THE THUNDERSTORMS HAVE STAYED AWAY FROM THE TAF SITES. ONCE BRUSHED KALB/KGFL...ONE IS JUST NORTH OF KPOU. IT LOOKS AS IF ONE CELL MIGHT HIT KPSF SO AMENDED TO INCLUDE A TEMPO FOR MVFR THUNDER 21-22Z. STILL MORE THUNDERSTORMS UPSTREAM ALTHOUGH OVERALL THE TREND HAS WEAKENED SLIGHTLY BUT STILL PLENTY OF INSTABILITY TO WORK WITH...NOT OUT OF THE WOODS YET. EXCEPT FOR KPSF WILL CONTINUE WITH GENERAL VCSH BUT THAT COULD CHANGE AT ANY TIME THROUGH 00Z. STAY TUNED AND KEEP CHECKING THE TAFS AND AVIATION DISCUSSION. AFTER WE LOOSE THE CELLS THIS EVENING...CONCERNS FOCUS TO FOG ISSUES...ESPECIALLY AT KGFL WHERE BELIEVE IT WILL HAPPEN. ELSEWHERE WENT WITH MVFR FOG. THE WINDS TODAY WILL BE FROM A WESTERLY DIRECTION AT 5-10 KNOTS WITH OCCASIONAL GUST TO 15 KNOTS. EXPECT THE WINDS TO BECOME LIGHT TO CALM IN THE EARLY EVENING AND REMAIN LIGHT THROUGH TUESDAY. OUTLOOK... TUE...MAINLY VFR. CHC -TSRA/-SHRA MAINLY DURING THE AFTN INTO THE EVNG. MVFR-IFR FOG LATE AT NIGHT INTO EARLY IN THE MORNING. WED...MAINLY VFR. SLIGHT CHC -TSRA/-SHRA. THU-FRI...VFR/MVFR. CHC -TSRAS/-SHRAS. && .FIRE WEATHER... VERY WARM AND HUMID CONDITIONS WILL CONTINUE EARLY THIS WEEK WITH THE THREAT OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EVENING HOURS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL. OUR NIGHTS WILL BE CONTINUE TO BE MUGGY WITH PATCHY FOG. MORE PERSISTENT CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED LATER IN THE WEEK INTO THE WEEKEND AS A SLOW MOVING LOW PRESSURE SYSTEM IMPACTS THE REGION. && .HYDROLOGY... INCREASING UNSETTLED WEATHER THIS WEEK. EARLY IN THE WEEK THE CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE MAINLY DURING THE AFTERNOON AND EVENING HOURS. HOWEVER...PERSISTENT CHANCES OF SHOWERS AND THUNDERSTORMS ARE EXPECTED FOR THE LATER PART OF THE WEEK INTO THE WEEKEND AS A MID/UPPER LEVEL TROUGH IMPACTS THE REGION. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL ALL WEEK WITH HIGH PRECIPITABLE WATER VALUES. EARLY IN THE WEEK FLOW ALOFT WILL BE RATHER LIGHT SO STORMS WILL BE SLOWER MOVERS. FLOW IS EXPECTED TO INCREASE LATER IN THE WEEK. PONDING OF WATER ON ROADWAYS ALONG WITH MINOR FLOODING OF LOW LYING AND POOR DRAINAGE AREAS WILL BE POSSIBLE. PLUS SOME SMALL STREAMS...CREEKS...AND BROOKS MAY REACH BANKFULL OR EVEN FLOODING QUICKLY IN THE HEAVY RAINFALL ASSOCIATED WITH THE THUNDERSTORMS ESPECIALLY IF STORMS MOVE OVER THE SAME AREA REPEATEDLY. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...BGM NEAR TERM...BGM SHORT TERM...BGM LONG TERM...BGM AVIATION...SND/HWJIV FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
148 PM EDT MON JUN 24 2013 .SYNOPSIS... VERY WARM AND HUMID CONDITIONS WILL CONTINUE EARLY THIS WEEK WITH THE THREAT OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EVENING HOURS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL. OUR NIGHTS WILL BE CONTINUE TO BE MUGGY WITH PATCHY FOG. MORE PERSISTENT CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED LATER IN THE WEEK INTO THE WEEKEND AS A SLOW MOVING LOW PRESSURE SYSTEM IMPACTS THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 955 AM...ANOTHER HAZY...HOT AND HUMID DAY SHAPING UP. 12Z ALY SOUNDING SHOWS PLENTY OF ENERGY FOR AFTERNOON THUNDERSTORMS. WATER VAPOR LOOP SHOWS CLOSED LOW SPINNING OVER WESTERN PENNSYLVANIA. THIS UPPER LEVEL LOW IS EXPECTED TO MOVE OVER THE SOUTHERN PART OF THE ALBANY FORECAST AREA OVER THE NEXT 12-18 HOURS AND SHOULD BE A FOCUS FOR STORMS. PWAT ON 12Z ALY SOUNDING WAS 1.77 INCHES SO COPIOUS MOISTURE FOR HEAVY RAINERS. PIT 12Z SOUNDING...UNDER UPPER LEVEL LOW...HAS STEEPER LAPSE RATES. 12Z HRRR SHOWING A MORE WIDESPREAD THREAT OF AFTERNOON STORMS. WILL HAVE TO MONITOR FOR LATER FLASH FLOOD WATCH IF LARGE AREA OF HEAVY RAIN DEVELOPS. COULD BE AN EXCITING DAY... PREVIOUS... THE RIDGE WILL WEAKEN A TAD TODAY AS THE REMNANTS OF THE UPPER LOW FROM OVER THE TENNESSEE VALLEY MOVES EASTWARD. THIS WILL BE THE MAIN FEATURE TRIGGERING CONVECTION ACROSS THE AREA TODAY AND IT WILL ACCOMPANY THE HEATING OF THE DAY. MODEL GUIDANCE SUGGESTS CAPE VALUES OF PEAKING AT 1000-2000 J/KG WITH DEW POINTS IN THE MID TO UPPER 60S. LAPSE RATE OF 6 TO 6.5 C/KM ARE EXPECTED THIS AFTERNOON WITH THE GFS INDICATING 7 C/KM POSSIBLE. MEAN FLOW IS RATHER WEAK AT 15 TO 20 KNOTS SO STORMS WILL MOVE RATHER SLOWLY AND CONVECTION WILL BE LOOSELY ORGANIZED. THE STORM PREDICTION CENTER HAS THE AREA/REGION IN THE GENERAL THUNDERSTORM OUTLOOK FOR TODAY AND TONIGHT. FREEZING LEVEL IS HIGH JUST OVER 14000 FEET ON THE 00Z/MON ALY SOUNDING...SO SOME STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL. THIS ALONG WITH THE RATHER SLOW MOVEMENT HAVE ADDED ENHANCED WORDING OF HEAVY RAINFALL TO THE FORECAST AND WILL KEEP MENTION IN THE HAZARDOUS WEATHER OUTLOOK. CONVECTION IS EXPECTED TO DIMINISH THIS EVENING AS THE WEAKENING UPPER LOW/TROUGH MOVES OFF TO THE EAST AND WITH THE LOSS OF DAYTIME HEATING. LOOKING AT TEMPERATURES IN THE 80S WITH AROUND 90 DEGREES UP THE HUDSON VALLEY INTO CAPITAL DISTRICT. DEW POINTS WILL BE IN THE MID TO UPPER 60S MAKING IT FELL EVEN HOTTER. HEAT INDICES SHOULD REACH THE MID 90S UP THE HUDSON RIVER VALLEY. ANOTHER MUGGY NIGHT WITH LOWS AND DEW POINTS IN THE 60S. WINDS WILL BECOME LIGHT TO CALM WINDS. HAVE ADDED PATCHY FOG MAINLY IN THE RIVER VALLEY LOCATIONS. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... BY TUESDAY MORNING FLOW WILL BECOME NEARLY ZONAL ACROSS THE REGION. A WEAKENING SURFACE LOW AND MID LEVEL SHORT WAVE TROUGH WILL MOVE EASTWARD ACROSS SOUTHERN CANADA PASSING WELL TO OUR NORTH TUESDAY. PLUS GUIDANCE INDICATES SMALL PIECES OF ENERGY SHOULD MOVE THROUGH THE FLOW FARTHER SOUTH ACROSS OUR REGION.ALL THIS LEADS TO ANOTHER ROUND OF CONVECTION MAINLY DURING THE AFTERNOON AND EVENING HOURS TUESDAY WITH THE HEATING OF THE DAY. THE BETTER DYNAMICS AND SHEAR WILL BE ACROSS NORTHERN NEW YORK INTO NORTHERN NEW ENGLAND AND THIS IS WHERE THE STORM PREDICTION CENTER HAS GONE WITH A SLIGHT RISK FOR SEVERE THUNDERSTORMS. FARTHER SOUTH ACROSS OUR FORECAST AREA MEAN FLOW WILL STILL BE RATHER WEAK AROUND 20 KNOTS. IT WILL BE ANOTHER HOT DAY SIMILAR TO MONDAY IN TEMPERATURES AND HEAT INDICES. A WEAK FRONTAL BOUNDARY WILL BE BROUGHT SOUTHWARD INTO THE REGION TUESDAY NIGHT...HOWEVER DUE TO THE FLOW ALOFT THE BOUNDARY WILL STALL ACROSS THE REGION. A MORE VIGOROUS SHORT WAVE WILL MOVE INTO THE LONGWAVE TROUGH OVER THE GREAT LAKES REGION WEDNESDAY AND WEDNESDAY NIGHT AND HEIGHTS WILL BEGIN TO FALL. CHANCES FOR CONVECTION WILL NOT BE LIMITED MAINLY TO THE AFTERNOON AND EVENING HOURS THIS TIME. AS HEIGHTS CONTINUE TO FALL WILL HAVE LARGE SCALE ASCENT THE BOUNDARY WILL BEGIN TO MOVE BACK NORTHWARD AS A WARM FRONT. PRECIPITABLE WATER VALUES WILL STILL BE HIGH SO LOCALLY HEAVY RAINFALL IS EXPECTED WITH SOME STORMS...SO HAVE MENTIONED IN OUR HAZARDOUS WEATHER OUTLOOK. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AN UNSETTLED AND WET EXTENDED FORECAST IS LIKELY ACROSS NY AND NEW ENGLAND WITH PERSISTENT CHANCES OF SHOWERS AND THUNDERSTORMS...AS A MID AND UPPER LEVEL TROUGH WILL INITIALLY IMPACT THE REGION TO CLOSE THE WEEK...AND THEN IT MAY CLOSE OR CUT OFF NEAR THE GREAT LAKES REGION AND SRN ONTARIO FOR THE WEEKEND. THE LATEST GFS/ECMWF/CANADIAN GGEM/ENSEMBLE GUIDANCE AND HPC GRAPHICS ARE IN PRETTY GOOD AGREEMENT FOR AN ACTIVE STRETCH OF WEATHER. THEIR ARE SOME SUBTLE DIFFERENCES FOR THE TIMING OF THE SHORT-WAVE IMPULSE ROTATING THROUGH THE UPPER LEVEL TROUGH...BUT ALL AN ALL...IT IS EXTREMELY DIFFICULT TO FIND A SUSTAINED DRY STRETCH OF WX TO CLOSE JUNE. THU-FRI...A WAVE OF LOW PRESSURE APPROACHES THE FCST AREA FROM THE GREAT LAKES REGION WITH SOME OVER RUNNING SHOWERS AND THUNDERSTORMS AHEAD OF A WARM FRONT. THE WARM FRONT MAY BUST THROUGH PORTIONS OF THE FCST AREA FOR A POTENTIAL OF STRONG THUNDERSTORMS...IF HEATING IS REALIZED. THE DETAILS ARE NEBULOUS AND MURKY...SO WE WILL CALL IT A CHANCE OF SHOWERS AND THUNDERSTORMS...THU INTO THU NIGHT. A S/SW H850 LLJ OF 30-45 KTS WILL TRANSPORT IN SOME GULF MOISTURE...AND PWATS WILL CONTINUE TO RUN ABOVE NORMAL. THE SFC LOW BEGINS TO OCCLUDE AND CLOSE OFF JUST NORTHWEST OF LAKE ONTARIO AND NRN NY ON FRI. THE GFS CONTINUES TO PAINT MODERATE AMOUNTS OF INSTABILITY FOR THE POTENTIAL OF SHOWERS AND THUNDERSTORMS AGAIN. THE SUBTROPICAL HIGH REMAINS ANCHORED DOWNSTREAM CONTINUING A DEEP S/SW FETCH OF MOISTURE. THIS LONG DURATION STRETCH OF WX...BEGINS TO MATERIALIZE INTO POTENTIALLY A CLASSIC GREAT LAKES CSTAR CUTOFF LOW WARM SEASON EVENT. TEMPS LOOK TO RUN SLIGHTLY BELOW TO NEAR NORMAL FOR THE THESE DAYS WITH HIGHS IN THE M70S TO L80S AND LOWS IN THE U50S TO 60S. SAT-MON...THE LONGWAVE TROUGH BEGINS TO AMPLIFY WITH THE EMBEDDED 500 HPA CLOSED CIRCULATIONS OVER THE CNTRL AND ERN GREAT LAKES. A COLD FRONT BEGINS TO STALL OUT NEAR THE ERN CONUS SEABOARD. MULTIPLE SHORT-WAVES LIFT NORTHWARD ON THE EAST SIDE OF TROUGH. PERSISTENT BANDS OF SHOWERS AND THUNDERSTORMS TIMED TO THE DIURNAL HEATING AND THE PROPAGATION OF THE IMPULSES ARE POSSIBLE FOR THE WEEKEND INTO EARLY NEXT WEEK. THEIR IS A SMALL POSSIBILITY THAT DRYING IN THE WAKE OF DISTURBANCES MAY PROMOTE MINI DRY STRETCHES. AGAIN...THIS APPEARS TO FIT A GREAT LAKES WARM SEASON CSTAR CLOSED/CUTOFF SCENARIO FOR AN EXTENDED PERIOD OF SHOWERS AND THUNDERSTORMS. THE WEEKEND IS DOMINATED BY A POSITIVE TILT SCENARIO...PERHAPS SHIFTING NEUTRAL BY EARLY NEXT WEEK. H850 TEMPS CONTINUE TO BE IN THE +14C TO +16C RANGE WITH LIMITED HEATING EACH DAY WITH A RESIDUAL COLD POOL ALOFT...AND THE ACTIVE S/SW FLOW. EXPECT HIGHS TO CONTINUE IN THE 70S TO L80S WITH LOWS IN THE U50S TO 60S. TOO EARLY TO PINPOINT LOCATIONS...BUT SOME HYDRO PROBLEMS COULD MATERIALIZE...IF LOCATIONS GET REPEATEDLY HIT BY BANDS OF SHOWERS AND THUNDERSTORMS. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... POP UP AFTERNOON THUNDERSTORMS DOT THE RADAR SCOPE. PROBABILITY OF ANY ONE STORM HITTING A TAF SITE IS STILL LESS THAN 30 PERCENT. WE`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
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
339 PM EDT MON JUN 24 2013 .SHORT TERM /TONIGHT THROUGH TUESDAY/... 500MB SURFACE ANALYSIS SHOWS A TROUGH SITUATED ACROSS NORTHERN GA...CENTRAL AL AND SOUTHEAST MS. SHOWERS AND THUNDERSTORMS HAVE DEVELOPED IN THE BASE OF THE TROUGH THIS AFTERNOON...AND CONTINUE TO APPROACH WESTERN GA. THE LATEST RUN OF THE HRRR HAS THE ACTIVITY FROM THE WEST CONGEALING WITH THE SE ACTIVITY LATE THIS AFTERNOON. ACTIVITY SHOULD DECREASE IN STRENGTH AND COVERAGE WITH THE LOSS OF HEATING FOR THE EARLY EVENING HOURS. FOR OVERNIGHT...WV LOOP SHOWS A GOOD PIECE OF SHORTWAVE ENERGY DROPPING SE IN THE FLOW ACROSS W KY THIS AFTERNOON. MODELS DO DEVELOP SCT ACTIVITY MAINLY ACROSS NORTHERN GA OVERNIGHT. WITH SOME MARGINAL INSTABILITY PRESENT OVERNIGHT...SCT SHRA/TSRA SEEM VERY REASONABLE. THE 500MB TROUGH AXIS IS PROGGED TO BE ACROSS THE CENTRAL CWFA DURING THE DAY TOMORROW. THIS SHOULD LEAD TO A LITTLE MORE COVERAGE OF STORMS ACROSS THE REGION. PWATS REMAIN THE SAME ACROSS NORTHERN GA...BUT WILL CREEP UP TO AROUND 2 INCHES ACROSS THE CENTRAL AND SOUTHERN CWFA. IN ADDITION...BL WINDS REMAIN VERY LIGHT (AOB 15K)...SO MOVEMENT OF STORMS WILL BE VERY SLOW OR NEARLY STATIONARY. EVEN THOUGH THE ATMOS WILL BE MARGINALLY UNSTABLE AT THE SURFACE...MID LEVEL LAPSE RATES AND SHEAR REMAIN VERY WEAK. THE POTENTIAL FOR SEVERE WEATHER REMAINS LOW...BUT STRONG THUNDERSTORMS ARE POSSIBLE...WITH AN ISOLATED SEVERE STORM NOT OUT OF THE QUESTION. NLISTEMAA .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... DIURNAL CONVECTION EXPECTED TO CONTINUE ACROSS THE AREA EACH AFTERNOON AND EVENING THROUGH DAY 7. MODELS IN GOOD AGREEMENT WITH SURFACE RIDGE LOSING ITS GRIP ON THE SOUTHEAST BY WEEKS END. THEY ARE ALSO IN GOOD AGREEMENT WITH THE UPPER LEVEL RIDGE BUILDING AND REMAINING OVER THE WESTERN US AS LONG WAVE TROUGH SETS UP OVER THE EAST COAST BY FRIDAY. WITH THE EASTERN EXTENT OF THE UPPER LEVEL RIDGE MORE LIMITED THAN PREVIOUSLY EXPECTED...HAVE COOLED EXTENDED HIGH TEMPERATURES A DEGREE OR TWO. STILL LOOKING FOR HIGHS IN THE UPPER 80S AND LOW 90S. HAVE INCREASED POPS SOMEWHAT FOR THE WEEKEND...AND EXPECT THIS UPWARD TREND IN THE FORECAST TO CONTINUE IN THE COMING DAYS. ENHANCED MOISTURE ACROSS THE REGION AS A RESULT OF THE UPPER LEVEL TROUGH AND ASSOCIATED FRONTAL BOUNDARY SHOULD SUPPORT MORE SIGNIFICANT COVERAGE OF PRECIP ACTIVITY. ANTICIPATE FRONTAL PASSAGE BY EARLY NEXT WEEK...WITH DROP IN POPS AND SLIGHTLY COOLER TEMPERATURES IN STORE AS A RESULT. 31/01 && .AVIATION... 18Z UPDATE... NO MAJOR CHANGES TO THE TAFS FOR THIS CYCLE. DIFFERENTIAL HEATING BOUNDARY AND SHEAR AXIS ALOFT CONTINUE TO DEVELOP SCT SHRA/TSRA ACROSS NORTHERN GA THIS AFTERNOON. IN ADDITION...A CONVERGENCE ZONE HAS ALSO DEVELOPED ACROSS THE SE. HAVE GONE VERY CLOSE TO THE 13Z HRRR SOLUTION...WITH THE BEST CHANCE OF TSRA AT ATL BETWEEN 21Z AND 23Z. COVERAGE SHOULD BE HIGHER TOMORROW AS SHEAR AXIX SLIPS EAST OVER THE CWFA TOMROROW. //ATL CONFIDENCE...18Z UPDATE... MEDIUM CONFIDENCE CONVECTIVE TIMING. HIGH CONFIDENCE REMAINING ELEMENTS. NLISTEMAA && .PRELIMINARY POINT TEMPS/POPS... ATHENS 69 87 69 90 / 50 50 20 30 ATLANTA 70 86 71 88 / 50 50 20 30 BLAIRSVILLE 64 81 64 86 / 40 40 20 40 CARTERSVILLE 69 88 69 89 / 50 40 20 30 COLUMBUS 71 91 72 92 / 60 60 20 30 GAINESVILLE 68 85 70 87 / 50 40 20 30 MACON 71 89 71 90 / 60 60 20 30 ROME 68 89 69 91 / 40 40 20 30 PEACHTREE CITY 69 87 69 88 / 50 50 20 30 VIDALIA 72 88 73 92 / 60 60 20 30 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...NLISTEMAA LONG TERM....01 AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
144 PM EDT MON JUN 24 2013 .PREV DISCUSSION... /ISSUED 1052 AM EDT MON JUN 24 2013/ UPDATE... 500MB ANALYSIS SHOWS A TROUGH ACROSS WESTERN AL. THIS FEATURE HAS SERVED TO FOCUS MOSTLY SHOWERS THIS MORNING ACROSS NORTH CENTRAL AL...AND NOW NW GA. DO THINK ANY SCT PRECIP LATE THIS MORNING AND EARLY AFTERNOON WILL BE CONCENTRATED CLOSEST TO THE TROUGH. HOWEVER...FOR THE REMAINDER OF THE AFTERNOON...DO THINK PRECIP WILL FOCUS JUST ALONG AND AHEAD OF THE SEA BREEZE ACROSS THE SE CWFA. THE 12Z RUN OF THE HRRR SHOWS THIS FAIRLY WELL. 12Z SOUNDING ANALYSIS SHOWS A MOIST COLUMN UP THROUGH 750MB WITH LIGHT SW FLOW IN THE BOUNDARY LAYER. PWATS ARE AROUND AN INCH AND THREE QUARTERS...SO ANY THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY DOWNPOURS. SURFACE WILL REMAIN PRETTY UNSTABLE THROUGH THE DAY...SO SCT/NRMS TSTMS WILL BE POSSIBLE. A FEW THUNDERSTORMS COULD BECOME STRONG AND PRODUCE PROLIFIC LIGHTNING STRIKES...BUT THE POTENTIAL FOR SEVERE WEATHER IS RATHER LOW. PREV DISCUSSION... /ISSUED 734 AM EDT MON JUN 24 2013/ SHORT TERM /TODAY THROUGH TUESDAY/... /ISSUED AT 402 AM EDT MON JUN 24 2013/ CURRENT CONVECTION OVER THE NORTHEAST MOUNTAINS RESPONDING TO A MOIST UPSLOPE FLOW ALOFT. THIS WILL SLOWLY SHIFT INTO NORTH CAROLINA HOWEVER THERE REMAINS ENOUGH OF A RISK TO KEEP LOW POPS GOING INTO THE MID MORNING HOURS. ISOLATED SHOWERS HAVE ALSO DEVELOPED ACROSS PARTS OF SOUTH AND EAST GA RESPONDING TO A WEAK SHORT WAVE IN THE MID LEVELS. THIS KEEPS ENOUGH OF A RISK TO KEEP LOW POPS GOING INTO THE MID MORNING HOURS AS WELL OVER PARTS OF CENTRAL GA. A SHORT WAVE MOVING THROUGH THE MISSISSIPPI VALLEY WILL MOVE INTO THE CWA THIS AFTERNOON. COMBINING THIS WITH AMPLE GULF AND ATLANTIC MOISTURE SHOULD AID IN SCATTERED TO NUMEROUS THUNDERSTORMS THIS AFTERNOON...MOST NUMEROUS ACROSS CENTRAL GA WHERE LIKELY POPS SEEM IN ORDER. CONVECTION SHOULD DIMINISH AFTER SUNSET WITH SOME LINGERING SHOWERS ACROSS THE NORTHEAST MOUNTAINS AND ALSO CENTRAL GA INTO THE MORNING HOURS ON TUESDAY. RISING H5 HEIGHTS WILL INCREASE THICKNESSES TODAY. THIS SHOULD PRODUCE WARMER TEMPS TODAY. THE NAM IS A BIT COOLER AND HAVE OPTED FOR THE WARMER GFS BOTH TODAY AND TUESDAY. 17 LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... /ISSUED AT 402 AM EDT MON JUN 24 2013/ DIURNAL CONVECTION EXPECTED EACH AFTERNOON AND EVENING THROUGH THE WEEK. MODELS IN GOOD AGREEMENT WITH SURFACE RIDGE LOSING ITS GRIP ON THE SOUTHEAST BY WEEKS END...AND UPPER LEVEL RIDGE BUILDING AND REMAINING OVER THE WESTERN US AS LONG WAVE TROUGH SETS UP OVER THE EAST COAST BY FRIDAY. WITH THE EASTERN EXTENT OF THE UPPER LEVEL RIDGE MORE LIMITED THAN PREVIOUSLY EXPECTED...HAVE COOLED EXTENDED HIGH TEMPERATURES A DEGREE OR TWO. STILL LOOKING FOR HIGHS IN THE UPPER 80S AND LOW 90S. HAVE INCREASED POPS SOMEWHAT FOR THE WEEKEND...AND EXPECT THIS UPWARD TREND IN THE FORECAST TO CONTINUE IN THE COMING DAYS. ENHANCED MOISTURE ACROSS THE REGION AS A RESULT OF THE UPPER LEVEL TROUGH AND ASSOCIATED FRONTAL BOUNDARY SHOULD SUPPORT MORE SIGNIFICANT COVERAGE OF PRECIP ACTIVITY. ANTICIPATE FRONTAL PASSAGE BY EARLY NEXT WEEK...WITH DROP IN POPS AND SLIGHTLY COOLER TEMPERATURES IN STORE AS A RESULT. 31 && .AVIATION... 18Z UPDATE... NO MAJOR CHANGES TO THE TAFS FOR THIS CYCLE. DIFFERENTIAL HEATING BOUNDARY AND SHEAR AXIS ALOFT CONTINUE TO DEVELOP SCT SHRA/TSRA ACROSS NORTHERN GA THIS AFTERNOON. IN ADDITION...A CONVERGENCE ZONE HAS ALSO DEVELOPED ACROSS THE SE. HAVE GONE VERY CLOSE TO THE 13Z HRRR SOLUTION...WITH THE BEST CHANCE OF TSRA AT ATL BETWEEN 21Z AND 23Z. COVERAGE SHOULD BE HIGHER TOMORROW AS SHEAR AXIX SLIPS EAST OVER THE CWFA TOMROROW. //ATL CONFIDENCE...18Z UPDATE... MEDIUM CONFIDENCE CONVECTIVE TIMING. HIGH CONFIDENCE REMAINING ELEMENTS. NLISTEMAA && .PRELIMINARY POINT TEMPS/POPS... ATHENS 87 69 89 70 / 50 50 50 20 ATLANTA 88 71 88 72 / 50 50 50 20 BLAIRSVILLE 83 63 84 65 / 40 40 40 20 CARTERSVILLE 87 68 88 70 / 50 50 40 20 COLUMBUS 91 73 92 73 / 50 50 60 20 GAINESVILLE 86 69 88 71 / 50 50 40 20 MACON 89 70 91 72 / 60 60 60 20 ROME 89 68 91 70 / 40 40 40 20 PEACHTREE CITY 88 68 90 70 / 50 50 50 20 VIDALIA 91 73 91 74 / 60 60 60 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
516 PM CDT MON JUN 24 2013 .MESOSCALE DISCUSSION... 505 PM CDT THE MOST FOCUS REMAINS ALONG THE I-88 CORRIDOR AND NORTH AND SOUTH OF THAT BY AROUND 30 MILES. THE APEX IS MOVING AT A FORWARD SPEED OF 60+ MPH AND THE MESO-VORTICY NEAR THE DEKALB/LASALLE BORDER HAS A FAIRLY LONG HISTORY...AFTER WEAKENING SOME FROM BUREAU COUNTY AND NOW HAS RE-INTENSIFIED. THIS CONTINUES TO BE VERY CLOSE TO A WEST-TO-EAST BOUNDARY PER EARLIER VISIBLE SATELLITE. 0-3 KM CAPE FROM SPC RAP OBJECTIVE ANALYSIS HAS VALUES AT 150-175 J/KG...SO CERTAINLY FAVORABLE FOR STRETCHING ALONG THIS. STILL...THE PRIMARY WIDESPREAD THREAT REMAINS DAMAGING WINDS PER RADAR AND ENVIRONMENTAL SIGNATURES. ON THE LARGE SCALE RADAR AND SATELLITE THIS FORWARD-PROPAGATING MCS LOOKS VERY WELL-ORGANIZED. THE ENVIRONMENT CONTINUES TO BE FAVORABLE FOR SUSTAINABILITY...WITH DEEP CAPE AT OR IN EXCESS OF 3000 J/KG...STEEP LOW-LEVEL LAPSE RATES AND ASSOCIATED THETA-E DIFFERENCE...AND STRONG 0-1 AND 0-3 KM SHEAR ADVECTING EAST WITHIN THE MCS FOR COLD POOL SUSTAINABILITY. MTF .DISCUSSION... 327 PM CDT SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT... A VERY ACTIVE PERIOD OF WEATHER IS EXPECTED...AT LEAST FOR PORTIONS OF THE AREA...THROUGH WEDNESDAY. THIS INCLUDES A FEW PERIODS OF SEVERE THUNDERSTORMS AND ALSO A GOOD THREAT FOR VERY HEAVY RAINFALL AND POSSIBLE FLASH FLOODING. AS SUCH...THIS WILL BE THE FOCUS OF THE FORECAST. WE HAVE EXTENDED THE FLASH FLOOD WATCH FOR OUR WESTERN COUNTIES THROUGH TONIGHT. TEMPERATURES ACROSS NORTHERN ILLINOIS AND NW INDIANA HAVE JUMPED INTO THE LOW TO MID 80S OVER THE PAST COUPLE HOURS AFTER THE MORNING CLOUD COVER CLEARED. WITH DEW POINTS NEAR 70...THIS IS RESULTING IN MLCAPES AROUND 2,000 J/KG ACROSS THE AREA...PER SPC MESOANALYSIS PAGE. IN ADDITION...IT APPEARS THAT THE 0-6 KM SHEAR MAY END UP A BIT STRONGER THAN PREVIOUSLY THOUGHT. VWP DATA INDICATES THAT A SPEED MAX AROUND 50 KT ...ASSOCIATED WITH A MID LEVEL DISTURBANCE MOVING INTO NORTHWESTERN IOWA...IS PUNCHING EASTWARD ACROSS IOWA. THUS IT APPEARS THAT 40 KT OF DEEP LAYER SHEER MAY OVERSPREAD THIS AREA LATER THIS AFTERNOON AND EVENING AS THIS SPEED MAX SHIFTS EASTWARD. CURRENT THOUGHTS ARE THAT THE LINE OF CONVECTION TO THE WEST WILL POSE A SEVERE THREAT FOR MOST OF THE AREA INTO THE EARLY EVENING HOURS. STRONG DAMAGING WINDS...POSSIBLY IN EXCESS OF 80 MPH...WILL BE THE PRIMARY THREAT ALONG WITH A SMALL POTENTIAL OF SOME MARGINALLY SEVERE HAIL. IT APPEARS THE MAIN FOCUS FOR CONVECTION MAY SHIFT NORTH INTO WISCONSIN LATER TONIGHT AS THE LOW LEVEL JET FOCUSES FARTHER NORTH. HOWEVER...THIS APPEARS TO BE SHORTED LIVED...AS CONVECTIVE CHANCES WILL RETURN ON TUESDAY. IT APPEARS THAT ADDITIONAL PERTURBATIONS IN THE MEAN QUASI-ZONAL MID LEVEL FLOW...WILL INTERACT WITH THE VERY MOIST AND UNSTABLE ATMOSPHERE ACROSS THE AREA. IT APPEARS THE CAP WILL REMAIN FAIRLY WEAK DURING THE DAY...SO IT APPEARS THAT AT LEAST SOME WIDELY SCATTERED CONVECTION MAY OCCUR...MAINLY ACROSS FAR NORTHERN ILLINOIS. THIS ACTIVITY COULD AGAIN POSS A SEVERE RISK ACROSS NORTHERN ILLINOIS WITH STEEP MID LEVEL LAPSE RATES HELPING PRODUCE MLCAPES IN EXCESS OF 3000 J/KG. TUESDAY CONVECTION LOOKS LIKE IT WILL BECOME MORE NUMEROUS TUESDAY EVENING/NIGHT. THE QUASI-ZONAL FLOW PATTERN ACROSS THE CONUS IS EXPECTED TO BEGIN AMPLIFYING...IN RESPONSE TO AN UPPER LOW OVER THE EASTERN PACIFIC. ULTIMATELY THIS WILL SET THE STAGE FROM A BUILDING MID/UPPER LEVEL RIDGE ACROSS THE WESTERN CONUS AND FALLING HEIGHTS ACROSS THE GREAT LAKES REGION. THIS PROCESS SHOULD ALLOW ANOTHER...STRONGER...SHORT WAVE TO MOVE ACROSS THE AREA ON WEDNESDAY. IT APPEARS THIS FEATURE WILL FOCUS THE NOSE OF A 40 KT LOW LEVEL JET RIGHT ACROSS SOUTHERN WISCONSIN AND NORTHERN ILLINOIS TUESDAY NIGHT INTO WEDNESDAY. THIS COULD SET THE STAGE FOR VERY HEAVY RAINFALL ACROSS PORTIONS OF NORTHERN ILLINOIS INTO WEDNESDAY. THIS LOOKS TO BE THE PERIOD TO REALLY WATCH FOR POSSIBLE FLOODING ACROSS THE AREA. PWATS ARE PROGGED TO REACH NEARLY 2.00 INCHES...WHICH IS AROUND THE 99 PERCENTILE. IN ADDITION...THE SOUTHWESTERLY ORIENTATION OF THE LOW LEVEL JET COULD OFFSET THE MEAN CLOUD BEARING FLOW...POSSIBLY RESULTING IN SLOW MOVING OR BACK BUILDING SEGMENTS TUESDAY NIGHT. HOWEVER...CONFIDENCE IN THE EXACT PLACEMENT OF THE HEAVIEST RAIN REMAINS IN QUESTION AT THIS TIME...BUT GUIDANCE IS HINTING THAT NORTHERN ILLINOIS COULD LIE IN THE FAVORED ZONE. THIS WILL HAVE TO BE WATCHED...WITH THE POSSIBLY OF A FLASH FLOOD WATCH NEEDED FOR PORTIONS OF NORTHERN ILLINOIS AND NORTHWESTERN INDIANA DURING THIS PERIOD. THE SEVERE CONVECTIVE THREAT SHOULD BEGIN TO WANE WEDNESDAY EVENING AS THE MID LEVEL DISTURBANCE SHIFT EAST OF THE AREA. TEMPERATURES LOOK TO CONTINUE TO BE PROBLEMATIC FOR THE NEXT COUPLE OF DAYS...WITH ADDITIONAL BUST POTENTIAL WITH CONVECTIVE ACTIVITY. HOWEVER...I ONLY MADE MINOR CHANCES TO THE GOING TEMP FORECAST...MAINLY TO COOL THE NORTHERN AREAS BY A COUPLE DEGREES. KJB EXTENDED FORECAST...THURSDAY THROUGH MONDAY... QUASI ZONAL FLOW IN THE SOUTHERN STREAM EARLY IN THE WEEK WILL TRANSITION BY THE SECOND HALF OF THE WEEK TO AN INCREASINGLY AMPLIFIED BROAD WESTERN CONUS RIDGE AND ITS CORRESPONDING LONGWAVE TROUGH OVER THE EASTERN CONUS. THIS WOULD PUT THE LOCAL AREA IN NORTHWEST UPPER FLOW EARLY IN THE WEEKEND...AND THEN UNDER AN UPPER LOW PUSHING SOUTHWEST ACROSS THE GREAT LAKES BY SUNDAY. THE MOST OBVIOUS RAMIFICATION WILL BE MUCH COOLER HIGHS...ESPECIALLY FOR THE WEEKEND AND EARLY NEXT WEEK. IN ADDITION...GFS/ECMWF ARE SUGGESTING THE POSSIBILITY OF THUNDERSTORMS TRIGGERED BY SHORTWAVE ENERGY DROPPING ACROSS THE AREA INTO THE BASE OF THE EASTERN TROUGH THURSDAY AND FRIDAY...WHEN CONSIDERABLE LOW LEVEL MOISTURE REMAINS IN PLACE OVER THE AREA. DEWPOINTS FALL ALONG WITH THE TEMPERATURES BY THE WEEKEND...BUT THE DEEPENING UPPER LOW ALSO SUPPORTS A CONTINUED CHANCE OF SHOWERS INTO MONDAY. EML && .DISCUSSION... 327 PM CDT SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT... A VERY ACTIVE PERIOD OF WEATHER IS EXPECTED...AT LEAST FOR PORTIONS OF THE AREA...THROUGH WEDNESDAY. THIS INCLUDES A FEW PERIODS OF SEVERE THUNDERSTORMS AND ALSO A GOOD THREAT FOR VERY HEAVY RAINFALL AND POSSIBLE FLASH FLOODING. AS SUCH...THIS WILL BE THE FOCUS OF THE FORECAST. WE HAVE EXTENDED THE FLASH FLOOD WATCH FOR OUR WESTERN COUNTIES THROUGH TONIGHT. TEMPERATURES ACROSS NORTHERN ILLINOIS AND NW INDIANA HAVE JUMPED INTO THE LOW TO MID 80S OVER THE PAST COUPLE HOURS AFTER THE MORNING CLOUD COVER CLEARED. WITH DEW POINTS NEAR 70...THIS IS RESULTING IN MLCAPES AROUND 2,000 J/KG ACROSS THE AREA...PER SPC MESOANALYSIS PAGE. IN ADDITION...IT APPEARS THAT THE 0-6 KM SHEAR MAY END UP A BIT STRONGER THAN PREVIOUSLY THOUGHT. VWP DATA INDICATES THAT A SPEED MAX AROUND 50 KT ...ASSOCIATED WITH A MID LEVEL DISTURBANCE MOVING INTO NORTHWESTERN IOWA...IS PUNCHING EASTWARD ACROSS IOWA. THUS IT APPEARS THAT 40 KT OF DEEP LAYER SHEER MAY OVERSPREAD THIS AREA LATER THIS AFTERNOON AND EVENING AS THIS SPEED MAX SHIFTS EASTWARD. CURRENT THOUGHTS ARE THAT THE LINE OF CONVECTION TO THE WEST WILL POSE A SEVERE THREAT FOR MOST OF THE AREA INTO THE EARLY EVENING HOURS. STRONG DAMAGING WINDS...POSSIBLY IN EXCESS OF 80 MPH...WILL BE THE PRIMARY THREAT ALONG WITH A SMALL POTENTIAL OF SOME MARGINALLY SEVERE HAIL. IT APPEARS THE MAIN FOCUS FOR CONVECTION MAY SHIFT NORTH INTO WISCONSIN LATER TONIGHT AS THE LOW LEVEL JET FOCUSES FARTHER NORTH. HOWEVER...THIS APPEARS TO BE SHORTED LIVED...AS CONVECTIVE CHANCES WILL RETURN ON TUESDAY. IT APPEARS THAT ADDITIONAL PERTURBATIONS IN THE MEAN QUASI-ZONAL MID LEVEL FLOW...WILL INTERACT WITH THE VERY MOIST AND UNSTABLE ATMOSPHERE ACROSS THE AREA. IT APPEARS THE CAP WILL REMAIN FAIRLY WEAK DURING THE DAY...SO IT APPEARS THAT AT LEAST SOME WIDELY SCATTERED CONVECTION MAY OCCUR...MAINLY ACROSS FAR NORTHERN ILLINOIS. THIS ACTIVITY COULD AGAIN POSS A SEVERE RISK ACROSS NORTHERN ILLINOIS WITH STEEP MID LEVEL LAPSE RATES HELPING PRODUCE MLCAPES IN EXCESS OF 3000 J/KG. TUESDAY CONVECTION LOOKS LIKE IT WILL BECOME MORE NUMEROUS TUESDAY EVENING/NIGHT. THE QUASI-ZONAL FLOW PATTERN ACROSS THE CONUS IS EXPECTED TO BEGIN AMPLIFYING...IN RESPONSE TO AN UPPER LOW OVER THE EASTERN PACIFIC. ULTIMATELY THIS WILL SET THE STAGE FROM A BUILDING MID/UPPER LEVEL RIDGE ACROSS THE WESTERN CONUS AND FALLING HEIGHTS ACROSS THE GREAT LAKES REGION. THIS PROCESS SHOULD ALLOW ANOTHER...STRONGER...SHORT WAVE TO MOVE ACROSS THE AREA ON WEDNESDAY. IT APPEARS THIS FEATURE WILL FOCUS THE NOSE OF A 40 KT LOW LEVEL JET RIGHT ACROSS SOUTHERN WISCONSIN AND NORTHERN ILLINOIS TUESDAY NIGHT INTO WEDNESDAY. THIS COULD SET THE STAGE FOR VERY HEAVY RAINFALL ACROSS PORTIONS OF NORTHERN ILLINOIS INTO WEDNESDAY. THIS LOOKS TO BE THE PERIOD TO REALLY WATCH FOR POSSIBLE FLOODING ACROSS THE AREA. PWATS ARE PROGGED TO REACH NEARLY 2.00 INCHES...WHICH IS AROUND THE 99 PERCENTILE. IN ADDITION...THE SOUTHWESTERLY ORIENTATION OF THE LOW LEVEL JET COULD OFFSET THE MEAN CLOUD BEARING FLOW...POSSIBLY RESULTING IN SLOW MOVING OR BACK BUILDING SEGMENTS TUESDAY NIGHT. HOWEVER...CONFIDENCE IN THE EXACT PLACEMENT OF THE HEAVIEST RAIN REMAINS IN QUESTION AT THIS TIME...BUT GUIDANCE IS HINTING THAT NORTHERN ILLINOIS COULD LIE IN THE FAVORED ZONE. THIS WILL HAVE TO BE WATCHED...WITH THE POSSIBLY OF A FLASH FLOOD WATCH NEEDED FOR PORTIONS OF NORTHERN ILLINOIS AND NORTHWESTERN INDIANA DURING THIS PERIOD. THE SEVERE CONVECTIVE THREAT SHOULD BEGIN TO WANE WEDNESDAY EVENING AS THE MID LEVEL DISTURBANCE SHIFT EAST OF THE AREA. TEMPERATURES LOOK TO CONTINUE TO BE PROBLEMATIC FOR THE NEXT COUPLE OF DAYS...WITH ADDITIONAL BUST POTENTIAL WITH CONVECTIVE ACTIVITY. HOWEVER...I ONLY MADE MINOR CHANCES TO THE GOING TEMP FORECAST...MAINLY TO COOL THE NORTHERN AREAS BY A COUPLE DEGREES. KJB EXTENDED FORECAST...THURSDAY THROUGH MONDAY... QUASI ZONAL FLOW IN THE SOUTHERN STREAM EARLY IN THE WEEK WILL TRANSITION BY THE SECOND HALF OF THE WEEK TO AN INCREASINGLY AMPLIFIED BROAD WESTERN CONUS RIDGE AND ITS CORRESPONDING LONGWAVE TROUGH OVER THE EASTERN CONUS. THIS WOULD PUT THE LOCAL AREA IN NORTHWEST UPPER FLOW EARLY IN THE WEEKEND...AND THEN UNDER AN UPPER LOW PUSHING SOUTHWEST ACROSS THE GREAT LAKES BY SUNDAY. THE MOST OBVIOUS RAMIFICATION WILL BE MUCH COOLER HIGHS...ESPECIALLY FOR THE WEEKEND AND EARLY NEXT WEEK. IN ADDITION...GFS/ECMWF ARE SUGGESTING THE POSSIBILITY OF THUNDERSTORMS TRIGGERED BY SHORTWAVE ENERGY DROPPING ACROSS THE AREA INTO THE BASE OF THE EASTERN TROUGH THURSDAY AND FRIDAY...WHEN CONSIDERABLE LOW LEVEL MOISTURE REMAINS IN PLACE OVER THE AREA. DEWPOINTS FALL ALONG WITH THE TEMPERATURES BY THE WEEKEND...BUT THE DEEPENING UPPER LOW ALSO SUPPORTS A CONTINUED CHANCE OF SHOWERS INTO MONDAY. EML && .HYDROLOGY... 433 PM CDT A SHORT PERIOD OF HEAVY RAINFALL WILL ACCOMPANY THE LINE OF STORMS CURRENTLY APPROACHING NORTH CENTRAL ILLINOIS. THIS COULD RESULT IN SOME MINOR FLOODING...ESPECIALLY IN AREAS THAT WERE HIT WITH 1 TO 2 INCHES OF RAINFALL THIS MORNING. HOWEVER...ADDITIONAL PERIODS OF HEAVY RAINFALL ARE EXPECTED LATE TUESDAY INTO WEDNESDAY. DURING THIS PERIOD PRECIPITABLE WATER VALUES COULD BE AROUND 2 INCHES...WHICH IS AROUND THE 99TH PERCENTILE. ANOTHER DECENT MID LEVEL DISTURBANCE IS EXPECTED TO APPROACH THE AREA TUESDAY NIGHT AND INTO WEDNESDAY...AND THIS SYSTEM LOOKS TO INDUCE A SOUTHWESTERLY LOW LEVEL JET...THAT COULD OFFSET THE FORWARD STORM MOTION...RESULTING IN SLOW MOVING OR BACK BUILDING THUNDERSTORMS TUESDAY NIGHT INTO WEDNESDAY. AT THIS TIME...UNCERTAINTY REMAINS AS TO WHERE EXACTLY THE HEAVIEST RAIN WILL FALL...BUT GUIDANCE CONTINUES TO HINT AT NORTHERN ILLINOIS AND NORTHWESTERN INDIANA. THIS WILL HAVE TO BE WATCHED FOR POSSIBILITY OF A FLASH FLOOD WATCH FOR MOST OF THE AREA AS RAINFALL AMOUNTS IN EXCESS OF 2 INCHES IS CERTAINLY POSSIBLE ACROSS PORTIONS OF THE AREA. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * SQUALL LINE/BOW ECHO TO IMPACT ORD/MDW AT 23Z * POTENTIAL FOR DAMAGING WIND GUSTS OF 60-75 KTS * VSBY REDUCED LESS THAN 1 MILE IN TORRENTIAL RAIN LASTING 15-25 MIN * STRONGEST WINDS LASTING 5 TO 10 MIN * PSBL FOG DEVELOPMENT OVERNIGHT INTO EARLY TUE. ED F //DISCUSSION...UPDATED 18Z... WARM AND HUMID CONDITIONS IN PLACE ALONG WITH VARIOUS BOUNDARIES TO KEEP NEXT ROUND OF SHRA/TSRA IN THE FORECAST INTO THIS EVENING. ATMOSPHERE TO CONTINUE TO RECOVER FROM MORNING CONVECTIVE ACTIVITY. THINKING IS A FEW TSRA ARE POSSIBLE BY MID AFTERNOON IN AREAS OF LESSENING/THINNING OF CLOUD COVER AND MAY EXPAND IN COVERAGE BY LATE AFTERNOON IF MORE WIDESPREAD SUNSHINE OCCURS. CIRROSTRATUS SHIELD ASSOCIATED WITH ORGANIZED AREAS OF TSRA/SHRA OVER IA MAY LIMIT AMOUNT/DURATION OF SUN. TSRA CLUSTERS OVER IA EXPECTED TO ORGANIZE FURTHER AND TRACK ACROSS NORTHERN ILLINOIS AND POSSIBLY NORTHWEST INDIANA INTO THE EVENING. SURFACE WARM FRONT EXPECTED TO REMAIN IN THE VICINITY OR JUST SOUTH OF THE TERMINALS. GIVEN HUMID ATMOSPHERE AND ADDITIONAL RAINFALL AREAS OF MAINLY LIGHT FOG ARE LIKELY OVERNIGHT. ZEBIC //ORD AND MDW CONFIDENCE...UPDATED 22Z... * HIGH CONFIDENCE IN SHRA/TSRA...MEDIUM CONFIDENCE IN PRECISE TIMING * LOW CONFIDENNCE IN SPECIFC PEAK WIND GUST VALUE - BEST ESTIMATE 45-50 KTS BUT POTENTIAL FOR GUST TO 75 KTS EXISTS. * LOW CONFIDENCE IN WIND FORECAST ONCE SQUALL LINE MOVES THROUGH... MAY SEE PERIOD OF EAST WINDS. * LOW CONFIDENCE IN OVERNIGHT FOG DEVELOPMENT REDUCING VSBYS. ED F //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH FRIDAY...PERIODIC CHANCES FOR THUNDERSTORMS. OTHERWISE EXPECT VFR CIGS. FRIDAY AND SATURDAY...CHANCE FOR SHOWERS. MAINLY VFR. SUNDAY...VFR. BEACHLER && .MARINE... 411 PM CDT HIGH PRESSURE REMAINS PARKED OFF THE CAROLINA COASTWHILE LOW PRESSURE CONTINUES TO DRIFT NORTHWARD ACROSS CENTRAL MANITOBA AND ONTARIO. ADDITIONAL LOW PRESSURE WILL DEVELOP FROM THE CANADIAN PRAIRIES TO THE NORTHERN PLAINS TUESDAY AND MOVE EASTWARD INTO WEDNESDAY WITH A CLOSED LOW DEVELOPING OVER THE WESTERN GREAT LAKES BY WEDNESDAY NIGHT. A LARGER LOW WILL DEVELOP IVER THE GREAT LAKES LATER FRIDAY AND LIKELY LINGER THROUGH THE WEEKEND BEFORE HIGH PRESSURE BUILDS IN FROM THE WEST EARLY NEXT WEEK. SOUTHERN WINDS WILL BE IN PLACE INTO WEDNESDAY WHEN THE FIRST SFC LOW PASSES WHICH WILL TURN WINDS WEST AND NORTHWEST. SPEEDS WILL FLUCTUATE UP AND DOWN UNTIL THE LOW PASSES SIMILAR TO PREVIOUS DAYS. A STABLE AIR MASS OVER THE WATER WILL KEEP AREAS OF DENSE FOG GOING ACROSS MUCH OF THE NORTHERN PART OF THE LAKE INTO TUESDAY AND PROBABLY INTO WEDNESDAY FOR THAT MATTER SO THE DENSE FOG ADVISORY MAY NEED TO BE EXTENDED. WIND SPEEDS LOOK TO REMAIN ON THE LIGHER SIDE FROM WEDNESDAY THROUGH THE WEEKEND WITH A FAIRLY BAGGY PRESSURE GRADIENT DEVELOPING AND THE DIRECTION WILL LIKELY VARY FROM WEST TO NORTH. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-ILZ019 UNTIL 7 AM TUESDAY. IN...NONE. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 10 AM TUESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
510 PM CDT MON JUN 24 2013 .MESOSCALE DISCUSSION... 505 PM CDT THE MOST FOCUS REMAINS ALONG THE I-88 CORRIDOR AND NORTH AND SOUTH OF THAT BY AROUND 30 MILES. THE APEX IS MOVING AT A FORWARD SPEED OF 60+ MPH AND THE MESO-VORTICY NEAR THE DEKALB/LASALLE BORDER HAS A FAIRLY LONG HISTORY...AFTER WEAKENING SOME FROM BUREAU COUNTY AND NOW HAS RE-INTENSIFIED. THIS CONTINUES TO BE VERY CLOSE TO A WEST-TO-EAST BOUNDARY PER EARLIER VISIBLE SATELLITE. 0-3 KM CAPE FROM SPC RAP OBJECTIVE ANALYSIS HAS VALUES AT 150-175 J/KG...SO CERTAINLY FAVORABLE FOR STRETCHING ALONG THIS. STILL...THE PRIMARY WIDESPREAD THREAT REMAINS DAMAGING WINDS PER RADAR AND ENVIRONMENTAL SIGNATURES. ON THE LARGE SCALE RADAR AND SATELLITE THIS FORWARD-PROPAGATING MCS LOOKS VERY WELL-ORGANIZED. THE ENVIRONMENT CONTINUES TO BE FAVORABLE FOR SUSTAINABILITY...WITH DEEP CAPE AT OR IN EXCESS OF 3000 J/KG...STEEP LOW-LEVEL LAPSE RATES AND ASSOCIATED THETA-E DIFFERENCE...AND STRONG 0-1 AND 0-3 KM SHEAR ADVECTING EAST WITHIN THE MCS FOR COLD POOL SUSTAINABILITY. MTF .DISCUSSION... 327 PM CDT SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT... A VERY ACTIVE PERIOD OF WEATHER IS EXPECTED...AT LEAST FOR PORTIONS OF THE AREA...THROUGH WEDNESDAY. THIS INCLUDES A FEW PERIODS OF SEVERE THUNDERSTORMS AND ALSO A GOOD THREAT FOR VERY HEAVY RAINFALL AND POSSIBLE FLASH FLOODING. AS SUCH...THIS WILL BE THE FOCUS OF THE FORECAST. WE HAVE EXTENDED THE FLASH FLOOD WATCH FOR OUR WESTERN COUNTIES THROUGH TONIGHT. TEMPERATURES ACROSS NORTHERN ILLINOIS AND NW INDIANA HAVE JUMPED INTO THE LOW TO MID 80S OVER THE PAST COUPLE HOURS AFTER THE MORNING CLOUD COVER CLEARED. WITH DEW POINTS NEAR 70...THIS IS RESULTING IN MLCAPES AROUND 2,000 J/KG ACROSS THE AREA...PER SPC MESOANALYSIS PAGE. IN ADDITION...IT APPEARS THAT THE 0-6 KM SHEAR MAY END UP A BIT STRONGER THAN PREVIOUSLY THOUGHT. VWP DATA INDICATES THAT A SPEED MAX AROUND 50 KT ...ASSOCIATED WITH A MID LEVEL DISTURBANCE MOVING INTO NORTHWESTERN IOWA...IS PUNCHING EASTWARD ACROSS IOWA. THUS IT APPEARS THAT 40 KT OF DEEP LAYER SHEER MAY OVERSPREAD THIS AREA LATER THIS AFTERNOON AND EVENING AS THIS SPEED MAX SHIFTS EASTWARD. CURRENT THOUGHTS ARE THAT THE LINE OF CONVECTION TO THE WEST WILL POSE A SEVERE THREAT FOR MOST OF THE AREA INTO THE EARLY EVENING HOURS. STRONG DAMAGING WINDS...POSSIBLY IN EXCESS OF 80 MPH...WILL BE THE PRIMARY THREAT ALONG WITH A SMALL POTENTIAL OF SOME MARGINALLY SEVERE HAIL. IT APPEARS THE MAIN FOCUS FOR CONVECTION MAY SHIFT NORTH INTO WISCONSIN LATER TONIGHT AS THE LOW LEVEL JET FOCUSES FARTHER NORTH. HOWEVER...THIS APPEARS TO BE SHORTED LIVED...AS CONVECTIVE CHANCES WILL RETURN ON TUESDAY. IT APPEARS THAT ADDITIONAL PERTURBATIONS IN THE MEAN QUASI-ZONAL MID LEVEL FLOW...WILL INTERACT WITH THE VERY MOIST AND UNSTABLE ATMOSPHERE ACROSS THE AREA. IT APPEARS THE CAP WILL REMAIN FAIRLY WEAK DURING THE DAY...SO IT APPEARS THAT AT LEAST SOME WIDELY SCATTERED CONVECTION MAY OCCUR...MAINLY ACROSS FAR NORTHERN ILLINOIS. THIS ACTIVITY COULD AGAIN POSS A SEVERE RISK ACROSS NORTHERN ILLINOIS WITH STEEP MID LEVEL LAPSE RATES HELPING PRODUCE MLCAPES IN EXCESS OF 3000 J/KG. TUESDAY CONVECTION LOOKS LIKE IT WILL BECOME MORE NUMEROUS TUESDAY EVENING/NIGHT. THE QUASI-ZONAL FLOW PATTERN ACROSS THE CONUS IS EXPECTED TO BEGIN AMPLIFYING...IN RESPONSE TO AN UPPER LOW OVER THE EASTERN PACIFIC. ULTIMATELY THIS WILL SET THE STAGE FROM A BUILDING MID/UPPER LEVEL RIDGE ACROSS THE WESTERN CONUS AND FALLING HEIGHTS ACROSS THE GREAT LAKES REGION. THIS PROCESS SHOULD ALLOW ANOTHER...STRONGER...SHORT WAVE TO MOVE ACROSS THE AREA ON WEDNESDAY. IT APPEARS THIS FEATURE WILL FOCUS THE NOSE OF A 40 KT LOW LEVEL JET RIGHT ACROSS SOUTHERN WISCONSIN AND NORTHERN ILLINOIS TUESDAY NIGHT INTO WEDNESDAY. THIS COULD SET THE STAGE FOR VERY HEAVY RAINFALL ACROSS PORTIONS OF NORTHERN ILLINOIS INTO WEDNESDAY. THIS LOOKS TO BE THE PERIOD TO REALLY WATCH FOR POSSIBLE FLOODING ACROSS THE AREA. PWATS ARE PROGGED TO REACH NEARLY 2.00 INCHES...WHICH IS AROUND THE 99 PERCENTILE. IN ADDITION...THE SOUTHWESTERLY ORIENTATION OF THE LOW LEVEL JET COULD OFFSET THE MEAN CLOUD BEARING FLOW...POSSIBLY RESULTING IN SLOW MOVING OR BACK BUILDING SEGMENTS TUESDAY NIGHT. HOWEVER...CONFIDENCE IN THE EXACT PLACEMENT OF THE HEAVIEST RAIN REMAINS IN QUESTION AT THIS TIME...BUT GUIDANCE IS HINTING THAT NORTHERN ILLINOIS COULD LIE IN THE FAVORED ZONE. THIS WILL HAVE TO BE WATCHED...WITH THE POSSIBLY OF A FLASH FLOOD WATCH NEEDED FOR PORTIONS OF NORTHERN ILLINOIS AND NORTHWESTERN INDIANA DURING THIS PERIOD. THE SEVERE CONVECTIVE THREAT SHOULD BEGIN TO WANE WEDNESDAY EVENING AS THE MID LEVEL DISTURBANCE SHIFT EAST OF THE AREA. TEMPERATURES LOOK TO CONTINUE TO BE PROBLEMATIC FOR THE NEXT COUPLE OF DAYS...WITH ADDITIONAL BUST POTENTIAL WITH CONVECTIVE ACTIVITY. HOWEVER...I ONLY MADE MINOR CHANCES TO THE GOING TEMP FORECAST...MAINLY TO COOL THE NORTHERN AREAS BY A COUPLE DEGREES. KJB EXTENDED FORECAST...THURSDAY THROUGH MONDAY... QUASI ZONAL FLOW IN THE SOUTHERN STREAM EARLY IN THE WEEK WILL TRANSITION BY THE SECOND HALF OF THE WEEK TO AN INCREASINGLY AMPLIFIED BROAD WESTERN CONUS RIDGE AND ITS CORRESPONDING LONGWAVE TROUGH OVER THE EASTERN CONUS. THIS WOULD PUT THE LOCAL AREA IN NORTHWEST UPPER FLOW EARLY IN THE WEEKEND...AND THEN UNDER AN UPPER LOW PUSHING SOUTHWEST ACROSS THE GREAT LAKES BY SUNDAY. THE MOST OBVIOUS RAMIFICATION WILL BE MUCH COOLER HIGHS...ESPECIALLY FOR THE WEEKEND AND EARLY NEXT WEEK. IN ADDITION...GFS/ECMWF ARE SUGGESTING THE POSSIBILITY OF THUNDERSTORMS TRIGGERED BY SHORTWAVE ENERGY DROPPING ACROSS THE AREA INTO THE BASE OF THE EASTERN TROUGH THURSDAY AND FRIDAY...WHEN CONSIDERABLE LOW LEVEL MOISTURE REMAINS IN PLACE OVER THE AREA. DEWPOINTS FALL ALONG WITH THE TEMPERATURES BY THE WEEKEND...BUT THE DEEPENING UPPER LOW ALSO SUPPORTS A CONTINUED CHANCE OF SHOWERS INTO MONDAY. EML && .HYDROLOGY... 433 PM CDT A SHORT PERIOD OF HEAVY RAINFALL WILL ACCOMPANY THE LINE OF STORMS CURRENTLY APPROACHING NORTH CENTRAL ILLINOIS. THIS COULD RESULT IN SOME MINOR FLOODING...ESPECIALLY IN AREAS THAT WERE HIT WITH 1 TO 2 INCHES OF RAINFALL THIS MORNING. HOWEVER...ADDITIONAL PERIODS OF HEAVY RAINFALL ARE EXPECTED LATE TUESDAY INTO WEDNESDAY. DURING THIS PERIOD PRECIPITABLE WATER VALUES COULD BE AROUND 2 INCHES...WHICH IS AROUND THE 99TH PERCENTILE. ANOTHER DECENT MID LEVEL DISTURBANCE IS EXPECTED TO APPROACH THE AREA TUESDAY NIGHT AND INTO WEDNESDAY...AND THIS SYSTEM LOOKS TO INDUCE A SOUTHWESTERLY LOW LEVEL JET...THAT COULD OFFSET THE FORWARD STORM MOTION...RESULTING IN SLOW MOVING OR BACK BUILDING THUNDERSTORMS TUESDAY NIGHT INTO WEDNESDAY. AT THIS TIME...UNCERTAINTY REMAINS AS TO WHERE EXACTLY THE HEAVIEST RAIN WILL FALL...BUT GUIDANCE CONTINUES TO HINT AT NORTHERN ILLINOIS AND NORTHWESTERN INDIANA. THIS WILL HAVE TO BE WATCHED FOR POSSIBILITY OF A FLASH FLOOD WATCH FOR MOST OF THE AREA AS RAINFALL AMOUNTS IN EXCESS OF 2 INCHES IS CERTAINLY POSSIBLE ACROSS PORTIONS OF THE AREA. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * SHRA/TSRA INTO EVENING AND ASSOCIATED POTENTIALLY ERRATIC WIND. * PSBL FOG DEVELOPMENT OVERNIGHT INTO EARLY TUE. ZEBIC //DISCUSSION...UPDATED 18Z... WARM AND HUMID CONDITIONS IN PLACE ALONG WITH VARIOUS BOUNDARIES TO KEEP NEXT ROUND OF SHRA/TSRA IN THE FORECAST INTO THIS EVENING. ATMOSPHERE TO CONTINUE TO RECOVER FROM MORNING CONVECTIVE ACTIVITY. THINKING IS A FEW TSRA ARE POSSIBLE BY MID AFTERNOON IN AREAS OF LESSENING/THINNING OF CLOUD COVER AND MAY EXPAND IN COVERAGE BY LATE AFTERNOON IF MORE WIDESPREAD SUNSHINE OCCURS. CIRROSTRATUS SHIELD ASSOCIATED WITH ORGANIZED AREAS OF TSRA/SHRA OVER IA MAY LIMIT AMOUNT/DURATION OF SUN. TSRA CLUSTERS OVER IA EXPECTED TO ORGANIZE FURTHER AND TRACK ACROSS NORTHERN ILLINOIS AND POSSIBLY NORTHWEST INDIANA INTO THE EVENING. SURFACE WARM FRONT EXPECTED TO REMAIN IN THE VICINITY OR JUST SOUTH OF THE TERMINALS. GIVEN HUMID ATMOSPHERE AND ADDITIONAL RAINFALL AREAS OF MAINLY LIGHT FOG ARE LIKELY OVERNIGHT. ZEBIC //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH CONFIDENCE IN SHRA/TSRA...MEDIUM CONFIDENCE IN PRECISE TIMING/COVERAGE. * HIGH CONFIDENCE IN WIND FORECAST. * LOW CONFIDENCE IN OVERNIGHT FOG DEVELOPMENT REDUCING VSBYS. ZEBIC //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH FRIDAY...PERIODIC CHANCES FOR THUNDERSTORMS. OTHERWISE EXPECT VFR CIGS. FRIDAY AND SATURDAY...CHANCE FOR SHOWERS. MAINLY VFR. SUNDAY...VFR. BEACHLER && .MARINE... 411 PM CDT HIGH PRESSURE REMAINS PARKED OFF THE CAROLINA COASTWHILE LOW PRESSURE CONTINUES TO DRIFT NORTHWARD ACROSS CENTRAL MANITOBA AND ONTARIO. ADDITIONAL LOW PRESSURE WILL DEVELOP FROM THE CANADIAN PRAIRIES TO THE NORTHERN PLAINS TUESDAY AND MOVE EASTWARD INTO WEDNESDAY WITH A CLOSED LOW DEVELOPING OVER THE WESTERN GREAT LAKES BY WEDNESDAY NIGHT. A LARGER LOW WILL DEVELOP IVER THE GREAT LAKES LATER FRIDAY AND LIKELY LINGER THROUGH THE WEEKEND BEFORE HIGH PRESSURE BUILDS IN FROM THE WEST EARLY NEXT WEEK. SOUTHERN WINDS WILL BE IN PLACE INTO WEDNESDAY WHEN THE FIRST SFC LOW PASSES WHICH WILL TURN WINDS WEST AND NORTHWEST. SPEEDS WILL FLUCTUATE UP AND DOWN UNTIL THE LOW PASSES SIMILAR TO PREVIOUS DAYS. A STABLE AIR MASS OVER THE WATER WILL KEEP AREAS OF DENSE FOG GOING ACROSS MUCH OF THE NORTHERN PART OF THE LAKE INTO TUESDAY AND PROBABLY INTO WEDNESDAY FOR THAT MATTER SO THE DENSE FOG ADVISORY MAY NEED TO BE EXTENDED. WIND SPEEDS LOOK TO REMAIN ON THE LIGHER SIDE FROM WEDNESDAY THROUGH THE WEEKEND WITH A FAIRLY BAGGY PRESSURE GRADIENT DEVELOPING AND THE DIRECTION WILL LIKELY VARY FROM WEST TO NORTH. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-ILZ019 UNTIL 7 AM TUESDAY. IN...NONE. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 10 AM TUESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1201 PM CDT MON JUN 24 2013 .DISCUSSION... ISSUED 1028 AM CDT MON JUN 24 2013 HAVE MADE ONLY MINOR CHANGES TO GRIDS AND ZFP THIS MORNING TO REFLECT THE CONTINUED POTENTIAL FOR THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS NORTH OF I-74. HRRR RUNS CONTINUE TO ALTERNATE BETWEEN LOW POPS FOR THE REMAINDER OF THE DAY AND AN MCS ROLLING ACROSS THE REGION. WITH SHORTWAVE NOW MOVING ACROSS IOWA COMBINING WITH ANTECEDENT BOUNDARIES AND ABUNDANT PRECIP WATER...OVER 2 STANDARD DEVIATIONS ABOVE CLIMATOLOGY...HAVE INCREASED POPS NORTH OF I-74 AND LOWERED HIGHS THERE. HAVE ALSO MADE SOME ADJUSTMENTS TO REFLECT ONLY SCATTERED CLOUDS IN KIJX/KSPI AREA. BARKER && .AVIATION... ISSUED 1201 PM CDT MON JUN 24 2013 DIFFICULT TO DELINEATE DETAILS IN THIS AFTERNOONS FORECAST. LOTS OF PLAYERS IN THE GAME THIS TIME AROUND. SHORTWAVE CROSSING IOWA IS CURRENTLY PRODUCING STRONG TO SEVERE CONVECTION. AS THE FORCING PUSHES EAST IT WILL INTERACT WITH RESIDUAL BOUNDARIES ACROSS ILLINOIS FROM LAST NIGHTS DOWNPOURS. ABUNDANT MOISTURE EVIDENT WITH 2+ STANDARD DEVIATION PRECIP WATER VALUES IN PLACE. HOWEVER...MODELS ARE FORECASTING SOME WARMING AT MID-LEVELS WHICH MAY LIMIT COVERAGE OF CONVECTION BY THE TIME IT REACHES CENTRAL ILLINOIS TAF SITES. FOR NOW WILL ASSUME THAT COLD POOL BEHIND INCOMING CONVECTION WILL BE SUFFICIENT TO COMPENSATE FOR ANY FORECASTED WARMING AND WILL HIT CONVECTION HARD...PARTICULARLY IN THE WESTERN TERMINALS LATE THIS AFTERNOON AND EARLY EVENING. IN SHORT-TERM...A PACKET OF GRAVITY WAVES IS PUSHING SOUTH THROUGH CENTRAL ILLINOIS AT THIS TIME ENABLING SOME LOW CLOUDS TO BRIEFLY IMPACT TERMINALS AND PRODUCING SOME WIND SHIFTS. WILL INCLUDE AS MUCH DETAIL AS POSSIBLE...BUT SOME GENERALIZATIONS WILL BE NECESSARY. BARKER && .PREV DISCUSSION... ISSUED 240 AM CDT MON JUN 24 2013 ONGOING PARADE OF MCS ACTIVITY AND ASSOCIATED HEAVY RAINFALL WILL CONTINUE TO BE A CONCERN FOR A COUPLE MORE DAYS. LATEST MCS COVERED A GOOD PORTION OF IOWA...ALBEIT A BIT SMALLER THAN RECENT NIGHTS...AND WAS BEING FED BY 40-45 KNOT LOW LEVEL JET. HAVE HAD SOME STRONG THUNDERSTORMS SPREADING INTO THE NORTHWEST CWA OVER THE LAST COUPLE HOURS ALONG A VERY SUBTLE SURFACE BOUNDARY. MESOSCALE VORTEX FROM SUNDAY CONVECTION OVER THE SOUTHEAST CWA STILL EVIDENT ON RADAR IMAGERY JUST EAST OF MOUNT VERNON. SHORT TERM...TODAY THROUGH WEDNESDAY... AS THE CASE HAS BEEN OVER THE LAST FEW DAYS...MODEL SOLUTIONS ARE FAIRLY VARIED WITH MESOSCALE FEATURES NOT HANDLED ESPECIALLY WELL. MCV IS ROTATING SOUTHEAST AND ACTIVITY WITH THIS FEATURE SHOULD BE OUT OF OUR AREA BY SUNRISE...SO AM PLANNING TO KEEP THE FAR SOUTHEAST DRY THIS MORNING. FOCUS DURING THE MORNING WILL MORE BE ACROSS THE NORTHWEST AND ANY INFLUENCES FROM LEFTOVER BOUNDARIES AND NEWER ONES FROM THE CURRENT CONVECTION. WILL HAVE THE HIGHEST POPS DURING THE AFTERNOON AS MORE OF THE DAYTIME HEATING IS A FACTOR. PRECIPITABLE WATER VALUES AROUND 1.7 TO 1.8 INCHES POINT TO SOME HEAVY DOWNPOURS AGAIN...ALTHOUGH CENTRAL PARTS OF THE CWA ARE MORE ABLE TO HANDLE THE HEAVY RAIN THAN THE SOUTHEAST...WHERE 1-HOUR FLASH FLOOD GUIDANCE IS ONLY AROUND A HALF INCH FROM EFFINGHAM TO FLORA. MAIN SEVERE WEATHER RISK WILL BE WEST OF I-55 THIS AFTERNOON WHERE 0-6KM SHEAR EXPECTED TO INCREASE TO AROUND 40 KNOTS...ALTHOUGH A PULSE SEVERE STORM CANNOT BE RULED OUT ELSEWHERE. MAIN THUNDERSTORM FOCUS SHIFTS NORTHWARD LATE TONIGHT THROUGH TUESDAY NIGHT. WITH MORE SUNSHINE...TUESDAY SHOULD BE THE HOTTEST DAY OF THE WEEK WITH HEAT INDEX VALUES AT OR JUST ABOVE 100. HAVE SOME CONCERN FOR SIMILAR VALUES WEDNESDAY...ALTHOUGH THIS WILL DEPEND ON TIMING OF A FRONTAL PASSAGE AND ASSOCIATED THUNDERSTORMS. MORE WIDESPREAD RISK OF SEVERE WEATHER EXPECTED ON WEDNESDAY WHICH WOULD HELP TEMPER THE HIGHS SOMEWHAT. SOME ADDITIONAL HEAVY RAIN LIKELY AGAIN ON WEDNESDAY WITH THE STORMS... AS PWAT VALUES RISE BACK TO AROUND 1.8 INCHES. LONG TERM...THURSDAY THROUGH SUNDAY... UPPER RIDGING STILL PROGGED TO BUILD ACROSS THE WESTERN CONUS DURING THE LATTER PART OF THE WEEK...WITH A SLOW COOLING TREND. CYCLONIC FLOW OVER THE GREAT LAKES JUSTIFIES SOME LOW CHANCE POPS OR SLIGHT CHANCES THURSDAY THROUGH FRIDAY...BUT THIS SHOULD FADE AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST OVER THE WEEKEND. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
400 PM CDT MON JUN 24 2013 ...UPDATED FOR SYNOPSIS AND SHORT TERM DISCUSSION... .SYNOPSIS... ISSUED AT 353 PM CDT MON JUN 24 2013 A FAIRLY STRONG SHORTWAVE TROUGH BY LATE JUNE STANDARDS WAS APPROACHING THE SOUTHERN AND CENTRAL HIGH PLAINS THIS AFTERNOON. AHEAD OF THIS FEATURE, STRONG SURFACE TROUGH HAD DEVELOPED OVER THE HIGH PLAINS, WITH STRONG SOUTHERLY WINDS ACROSS SOUTHWEST KANSAS. ELEVATED CONVECTION IN ADVANCE OF THIS SYSTEM DEVELOPED THIS MORNING EAST OF DODGE CITY AND THEN MOVED EAST AND WEAKENED. ANOTHER BATCH OF ELEVATED CONVECTION DEVELOPED WEST OF A SURFACE DRYLINE IN SOUTHEAST COLORADO AND MOVED INTO FAR SOUTHWEST KANSAS THIS AFTERNOON. SURFACE BASED CONVECTION HAD NOT YET DEVELOPED AS OF 3 PM. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 353 PM CDT MON JUN 24 2013 THE SHORT RANGE HRRR DOES INDICATE STORMS DEVELOPING IN THE TEXAS AND OKLAHOMA PANHANDLES THIS AFTERNOON AS UPPER LEVEL FORCING AIDS IN LOW LEVEL CONVERGENCE ALONG THE DRYLINE. GIVEN THE FAIRLY STRONG MID LEVEL FLOW FROM THE SOUTHWEST, THIS CONVECTION SHOULD MOVE NORTHEASTWARD FAIRLY RAPIDLY INTO SOUTHWEST KANSAS THIS EVENING. SURFACE BASED CAPE VALUES WERE APPROACHING 3000 J/KG FROM THE TEXAS PANHANDLE INTO SOUTHWEST KANSAS AHEAD OF THE DRYLINE. 0-6 KM BULK SHEAR WAS APPROACHING 40 KTS IN THIS SAME AREA, BUT LOW LEVEL SHEAR WAS VERY WEAK. GIVEN THE EXPECTED HIGH DEWPOINT DEPRESSIONS AND RESULTANT HIGH CLOUD BASES, THE STORMS MAY DEVELOP QUITE A BIT OF OUTFLOW, AND THIS MAY LIMIT THE SEVERITY AS FAR AS HAIL SIZE IS CONCERNED (SINCE THE STORMS MAY NOT REMAIN AS SUPERCELL STRUCTURES AS LONG). BUT HAIL AS LARGE AS GOLFBALLS IS POSSIBLE WITH THE STRONGEST STORMS. IT IS UNCLEAR HOW ORGANIZED THE STORMS WILL BE AND HOW WIDESPREAD AND HEAVY THE RESULTANT RAINFALL WOULD BE. BUT STORM CHANCES WERE INCREASED TO 30-40% FOR PARTS OF SOUTHWEST KANSAS INCLUDING DODGE CITY, JETMORE AND LARNED GIVEN THE SIGNIFICANT FORCING AND SURFACE BASED CAPE. AFTER THE AFOREMENTIONED SHORTWAVE TROUGH PASSES TONIGHT AND WITH THE LOSS OF DAYTIME HEATING, STORM CHANCES WILL DIMINISH RAPIDLY BY LATE EVENING. THE LOW LEVEL WINDS WILL BEGIN TO VEER AS WELL AND THIS WILL RESULT IN THE AXIS OF DEEP MOISTURE SHIFTING EASTWARD. SOUTHWEST WINDS AT 15 KTS EVEN LATE TONIGHT WILL PREVENT TEMPERATURES FROM DROPPING BELOW THE LOWER 70S AT DODGE CITY, HAYS AND PRATT, WITH ONLY SLIGHTLY COOLER READINGS NEAR THE COLORADO BORDER. BEHIND THE SHORTWAVE TROUGH, A WEAK COLD FRONT WILL PROGRESS INTO CENTRAL KANSAS TUESDAY AFTERNOON, WITH A TRAILING DRYLINE EAST OF DODGE CITY AND INTO THE PANHANDLES. VERY HOT TEMPERATURES FROM 103 TO 106F ARE EXPECTED IMMEDIATELY BEHIND THE DRYLINE WHERE THE LOW LEVEL AIR HAS MOVED DOWNSLOPE AND WARMED ADIABATICALLY. ONLY SLIGHTLY COOLER AIR CAN BE EXPECTED IN FAR WESTERN KANSAS ON THE HIGHER TERRAIN, AND BEHIND THE WEAK COLD FRONT FROM WAKEENEY TO DIGHTON. THUNDERSTORMS ARE NOT EXPECTED TUESDAY AFTERNOON GIVEN THE LACK OF FORCING IN THE WAKE OF THE SHORTWAVE TROUGH AND SINCE THE LOW LEVEL MOIST AXIS WILL HAVE SHIFTED FURTHER EAST BY THE TIME OF PEAK HEATING. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 336 PM CDT MON JUN 24 2013 ZONAL FLOW ALOFT WILL BE IN PLACE OVER THE LOWER 48 STATES AT THE BEGINNING OF THE EXTENDED PERIOD. A SHORTWAVE TROUGH THAT IS NOW MOVING THROUGH THE GREAT BASIN AND DESERT SOUTHWEST WILL BE EXITING THE NORTHERN AND CENTRAL PLAINS TUESDAY EVENING. THIS SYSTEM WILL BRING A WEAK FRONTAL BOUNDARY SOUTH ACROSS WESTERN KANSAS IN ITS WAKE LATE TUESDAY AFTERNOON AND EVENING. PRECIPITATION CHANCES LOOK FAIRLY SMALL GIVEN THE LACK OF UPPER SUPPORT AND A FAIRLY DRY AIRMASS. THROUGH THE MIDDLE PART OF THE WEEK, 500 MILLIBAR HEIGHTS WILL BE BUILDING OVER THE WESTERN AND CENTRAL PART OF THE COUNTRY. WITH INCREASING THICKNESS VALUES OVER WESTERN KANSAS WE SHOULD SEE DAYTIME HIGH TEMPERATURES WARMING BACK UP TO AROUND OR ABOVE 100 DEGREES ESPECIALLY BY THURSDAY. THE UPPER RIDGE BECOMES MORE AMPLIFIED OVER WESTERN NORTH AMERICA TOWARD THE UPCOMING WEEKEND WITH UPPER LEVEL FLOW BECOMING MORE NORTHWESTERLY OVER THE CENTRAL PLAINS. A WEAK FRONTAL BOUNDARY IS FORECAST TO MOVE SOUTH THROUGH THE CENTRAL HIGH PLAINS EARLY FRIDAY WITH EASTERLY UPSLOPE FLOW SETTING UP INTO THE EASTERN SLOPES OF THE ROCKIES. AFTERNOON THUNDERSTORMS SHOULD DEVELOP OFF THE FRONT RANGE. GIVEN THE UPPER LEVEL FLOW, SOME OF THESE COULD MOVE INTO FAR WESTERN KANSAS FRIDAY EVENING. THE UPPER LEVEL FLOW OVER THE CENTRAL PART OF THE COUNTRY BECOMES EVEN MORE MERIDIONAL THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THE MEDIUM RANGE MODELS HAVE ALL BEEN TRENDING IN THIS DIRECTION THROUGH THE PAST FEW RUNS. THINK THAT THE CURRENT WEEK TWO OUTLOOK SHOULD BE TRENDED BACK TO AT LEAST NEAR NORMAL TEMPERATURES FOR NOW BUT BASED ON FORECAST TEMPERATURES, WE COULD BE EVEN COOLER. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1256 PM CDT MON JUN 24 2013 A TROUGH OF LOW PRESSURE IN THE LEE OF THE ROCKIES WILL LEAD TO STRONG SOUTH WINDS THROUGH TONIGHT, WITH 20-25 KTS TODAY AND 15KTS TONIGHT. THE WINDS WILL GRADUALLY WEAKEN AND SHIFT TO THE WEST AFTER 12Z TUESDAY AS THE SURFACE TROUGH PROGRESSES EASTWARD INTO WESTERN KANSAS. THERE IS A SMALL CHANCE OF A THUNDERSTORM NEAR KHYS AND KDDC THIS AFTERNOON AND EVENING. VFR CONDITIONS WILL PERSIST ASIDE FROM THUNDERSTORMS. && .PRELIMINARY POINT TEMPS/POPS... DDC 74 105 69 101 / 40 0 0 0 GCK 72 104 65 101 / 20 0 0 0 EHA 70 103 66 101 / 10 0 0 0 LBL 74 105 68 104 / 20 0 0 0 HYS 74 104 70 101 / 30 0 0 0 P28 74 100 74 101 / 20 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ030-031-043>046- 062>066-075>081-085>090. RED FLAG WARNING UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR KSZ061-062-074. && $$ SYNOPSIS...FINCH SHORT TERM...FINCH LONG TERM...GERARD AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1252 PM CDT MON JUN 24 2013 .UPDATE... ISSUED AT 1251 PM CDT MON JUN 24 2013 UPDATED THE FORECAST TO ADD SCATTERED THUNDERSTORMS FOR MUCH OF THE AREA FOR THE REST OF THE AFTERNOON. A SMALL WAVE WAS MOVING NORTHEAST OUT OF NEW MEXICO AND HAS SUSTAINED CONVECTION FROM SOUTHWEST KANSAS INTO NORTHEAST KANSAS. ATMOSPHERE REMAINS UNSTABLE WITH PLENTY OF MOISTURE. WATER VAPOR SATELLITE SHOWING A MOISTURE STREAMING NORTHEAST FROM MEXICO. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 352 AM CDT MON JUN 24 2013 ANOTHER DIFFICULT FORECAST AS MESOSCALE FEATURES CONTINUE TO DEFINE CONVECTIVE POTENTIAL...AND ARE DIFFICULT TO FORECAST MORE THAN A FEW HOURS OUT. FOR TODAY...SOUNDINGS SUGGEST WAVE LIFTING OUT OF OK/CTRL KS MAY SATURATE MID LEVELS ENOUGH TO SUPPORT SOME ISOLATED CONVECTION THIS MORNING...AND WILL LEAVE AN ISOLATED POP TO REFLECT THIS. HRRR MODEL...WHICH HAS PERFORMED WELL IN THE MORNING RUNS THIS WEEK...DEPICTS CONVECTIVE COMPLEX OVER SC NEBRASKA SLIDING SLIGHTLY TO THE SE AND BACK-BUILD INTO OUR FORECAST AREA LATER THIS MORNING. FRONTAL BOUNDARY HAS SHIFTED FARTHER NORTHWARD AND SUSPECT COMPLEX WILL STAY NORTH OF THE FA. ALSO SHOULD CONSIDER OUTFLOW MOVING SE OUT OF IOWA CONVECTION AND WHERE THAT MAY END UP ON THE KS/MO BORDER THIS AFTERNOON. AT THIS TIME LESS CINH AND BETTER DYNAMICS COME TOGETHER NORTH OF THE AREA. HAVE STARTED WITH A SILENT POP IN THE NE COUNTIES AND WILL MONITOR FOR DEVELOPMENT. BREEZY SOUTHERLY WINDS WILL BE NEAR BUT GENERALLY BELOW WIND ADVISORY CRITERIA AND WILL HOLD OFF FOR NOW. HIGHS TODAY IN THE 90S FOLLOWED BY WARM OVERNIGHT LOWS IN THE MIDDLE 70S. WITH ANOTHER COMPLEX MOVING NORTH OF THE FORECAST AREA LATE MONDAY INTO EARLY TUESDAY...WILL CARRY A SLIGHT CHANCE POP ACROSS THE FAR NORTHERN COUNTIES AS MAY SEE SOME LATE NIGHT COLD POOL LLJ INTERACTION. 67 .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 352 AM CDT MON JUN 24 2013 MID RANGE AND EXTENDED FORECAST (TUESDAY THROUGH SUNDAY)... WARM...MUGGY...AND DRY CONDITIONS EXPECTED TO PERSIST THROUGH MOST OF THE MID RANGE AND EXTENDED PERIOD. FOR TUESDAY AND WEDNESDAY THE MID LEVEL RIDGE GETS SOMEWHAT FLATTENED OUT AND DEAMPLIFIED AS THE HIGH PRESSURE EXPANDS ACROSS THE SOUTHERN PLAINS. EVENTUALLY...BY MID WEEK THE RIDGE WILL BECOME CENTERED OVER THE FOUR CORNERS REGION OF THE US...AND WILL BECOME MOVE AMPLIFIED AS THE WEEK PROGRESSES. WITH THE EASTERN EDGE OF THE HIGH PRESSURE DOME IN THE VICINITY OF NORTHEAST KANSAS EXPECT SOME MID LEVEL NWLY FLOW TO REMAIN OVER THE FORECAST AREA...WHICH WILL BRING THE POTENTIAL FOR MCS DEVELOPMENT WITHIN THE FLOW. FOR NOW WILL KEEP A MOSTLY DRY FORECAST THROUGH THE EXTENDED PERIOD...WITH THE LONE EXCEPTION OF THURSDAY NIGHT WHERE THE ECMWF AND GFS AGREE ON THUNDERSTORMS DEVELOPING ALONG THE PERIPHERY OF THE RIDGE AND DROPPING SOUTH/SOUTHEASTWARD OUT OF SE NEBRASKA INTO NE KANSAS. GIVEN THE LACK OF ANY STRONG SIGNAL OF OBVIOUS LIFTING MECHANISMS WILL ONLY GO WITH A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS FOR THAT PERIOD. OTHERWISE...EXPECT A RATHER WARM AND MUGGY PERIOD FOR TUES THROUGH THURS AS DAY TIME HIGHS WILL GENERALLY REACH THE MID TO UPPER 90S...WITH HEAT INDEX VALUES RANGING BETWEEN 100 AND 105 ACROSS MOST OF THE FORECAST AREA. TEMPERATURES WILL COOL OFF A BIT FOR THE END OF THE WORK WEEK THROUGH THE WEEKEND...AS A SURFACE HIGH BRINGS COOLER AIR INTO NORTHEAST KANSAS. EXPECT TEMPS FOR FRIDAY THROUGH MONDAY TO BE IN THE UPPER 80S TO PERHAPS THE MID 90S. JL && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1251 PM CDT MON JUN 24 2013 VFR CONDITIONS EXPECTED OUTSIDE OF CONVECTIVE ACTIVITY THROUGH THE PERIOD. SOUTH WINDS WILL CONTINUE NEAR 16 KTS WITH HIGHER GUSTS. CONVECTIVE OUTFLOW BOUNDARIES WILL AFFECT THE WIND DIRECTION AND SPEED. ADDED VCTS FOR SCATTERED CONVECTION THAT MAY LAST UNTIL 23Z. WINDS WILL DECREASE SOME TONIGHT THEN INCREASE AGAIN AFTER 14Z TUESDAY. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...53 SHORT TERM...CRAVEN LONG TERM...LEIGHTON AVIATION...53
AREA FORECAST DISCUSSION
NWS CARIBOU ME
123 PM EDT MON JUN 24 2013 .SYNOPSIS... UNSETTLED CONDITIONS WITH SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST THROUGH MID WEEK. && .NEAR TERM /THROUGH TONIGHT/... 1PM UPDATE... ADDED ENHANCED WORDING FOR THUNDERSTORMS THIS EVENING IN NORTHERN ZONES. STRONG THUNDERSTORMS IN QUEBEC WILL ADVECT TOWARDS THE NORTHWESTERN PORTION OF THE STATE THIS EVENING. THE STORMS WILL WEAKEN AS THEY CROSS THE FORECAST AREA THIS EVENING. BEST CHANCE FOR THE STRONGER STORMS WILL BE IN NORTHERN SOMERSET...NORTHERN PISCATAQUIS AND NORTHERN AROOSTOOK COUNTIES. IN A LINE DOES FORM...WILL HAVE TO CONSIDER ADDING POPS TO SOUTHERN PISCATAQUIS AND PENOBSCOT COUNTIES FOR THIS EVENING. 10AM UPDATE... THE DECAYING MCS IS BRINGING SHOWERS TO HANCOCK AND WASHINGTON COUNTIES AT THIS TIME AND WILL EXIT THE FORECAST AREA IN THE NEXT FEW HOURS. SKIES WILL CLEAR FROM NW TO SE AS THE CLOUDS ASSOCIATED WITH THE OLD MCS LEAVE THE STATE. THIS WILL PRODUCE HIGHS IN THE MID TO UPPER 80S WITH UNCOMFORTABLE HUMIDITY. ADJUSTED HIGHS UP A FEW DEGREES. DAYTIME HEATING WILL CREATE SOME DESTABILIZATION WITH THE BEST CHANCES FOR STRONG STORMS IN THE REMOTE AREAS OF NORTHERN SOMERSET...PISCATAQUIS AND AROOSTOOK COUNTIES THIS EVENING. STRONG WIND GUSTS WOULD APPEAR TO BE THE BIGGEST THREAT. HOWEVER...WITH A STRONG LLJ...HIGH PWATS AND WELL OVER 10K FT OF WARM CLOUD...HEAVY RAIN IS ALSO A CONCERN. UPDATE 0530L: DECAYING MCS HAS REACHED OUR FAR WRN ZONES ATTM. THIS A LITTLE FASTER THAN ERLYR EXPECTED SO HAVE ADJUSTED POPS FOR CURRENT AND EXPECTED TRENDS THRU THE AM HRS. REMAINDER OF THE FCST UNCHANGED... DECAYING MCS OVR SRN QUEBEC ATTM ABOUT TO ENTER FAR WRN MAINE... OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ACROSS THE FA ATTM W/ SOME FOG ACROSS THE N. NOT MUCH CHANGE IN THE OVERALL PTRN ACROSS OUR AREA LAST 24 HRS AT LEAST IN THE UPPER LEVELS OF THE ATMOS AS BRISK WNW FLOW ALOFT PERSISTS W/ OCNL DISTURBANCES EMBEDDED IN THIS FLOW. IN THE LOWER LEVELS - A VRY WARM AND HUMID SWRLY FLOW IS NOW IN PLACE ACROSS THE ENTIRE REGION W/ TDS GENERALLY IN THE LOWER TO MID 60S. THE DECAYING MCS IS SHOWN BY THE SHORTER TERM MODELS SUCH AS THE RUC TO CONT TO MV ESEWRD AND HOLD TOGETHER ENUF TO HAVE SOME IMPACT ON OUR WRN ZNS ERLY TDY THEN ACROSS OUR S CENTRAL ZNS THRU THE AM HRS AND POPS ACROSS THESE AREAS WILL REFLECT THIS. OTHERWISE...ANOTHER UPPER DISTURBANCE IS FCST TO SLIDE ESEWRD ACROSS THE FA LATER TDY AND PROVIDE ANOTHER UPTICK IN SHOWERS/TSTMS. UNLIKE SUN...WHERE MOST ACTION WAS S OF THE AREA - APPEARS TDY THAT THINGS HAVE SHIFTED A LITTLE FURTHER N W/ THE INTRUSION OF THE WARMER AND MORE HUMID AIR. AS A RESULT...WILL CARRY MAINLY CHC POPS ACROSS THE REMAINDER OF THE FA TDY INTO THIS EVE W/ ACTIVITY EXPECTED TO AGAIN WEAKEN/DISSIPATE LATER THIS EVE AS THIS UPPER DISTURBANCE MVS AWAY FROM THE REGION. THIS WILL SET THE STAGE FOR MORE PATCHY FOG W/ THE FOG PROBABLY A LITTLE MORE WDSPRD THAN THIS AM W/ THE HUMID AIRMASS PERSISTING. TEMPS TDY WILL BE A LITTLE TRICKY... CLDS AND SHOWERS WILL NO DOUBT HAVE SOME IMPACT AND PROBABLY KEEP MOST AREAS FROM REACHING FULL POTENTIAL TDY. STILL...A LITTLE SUNSHINE FROM TIME TO TIME IS EXPECTED AND WILL GO A LONG WAY IN HEATING THINGS UP SO WILL HANG ONTO HIGHS INTO THE LOWER 80S N W/ MID TO PSBLY UPPER 80S CENTRAL AND INTERIOR DOWN EAST... && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... PERIOD WILL BEGIN WITH A SURFACE HIGH SETUP IN THE ATLANTIC AND BOUNDARY DRAPED JUST TO THE NORTH OF THE REGION. THE SURFACE HIGH WILL CONTINUE TO PUMP WARM AND MOIST AIR INTO THE REGION. GUIDANCE IS IN FAIR AGREEMENT WITH THE BOUNDARY AND SURFACE LOW BEGINNING TO DROP SOUTH THROUGH THE DAY ON TUESDAY. THIS COMBINED WITH BETTER UPPER LEVEL DYNAMICS WITH THE REGION LOCATED IN THE FAVORABLE RIGHT ENTRANCE REGION OF UPPER LEVEL JET ENHANCING DIVERGENCE ALOFT. ALSO WITH WARM AND MOIST UNSTABLE AIR IN PLACE CAPE VALUES WILL BE GENERALLY BETWEEN 500 TO 1500 J/KG. THESE DYNAMICS WILL MAKE IT POSSIBLE TO HAVE SOME MORE ENHANCED THUNDERSTORM ACTIVITY TUESDAY AFTERNOON AND EVENING. RIGHT NOW THINKING IS THERE WILL BE THE POTENTIAL FOR SMALL HAIL AND GUSTY WINDS BUT THIS MAY NEED TO BE ENHANCED FURTHER IF DYNAMICS CONTINUE TO COME TOGETHER. BEST CHANCES STILL LOOK TO BE ACROSS THE NORTHERN AND CENTRAL PORTIONS OF THE REGION WHERE BEST SUPPORTING DYNAMICS ARE PRESENT. THERE IS SOME MODEL DIVERGENCE FOR WEDNESDAY WITH THE MOST OF GUIDANCE WANTING TO KEEP THE LOW PRESSURE ACROSS THE REGION WHILE THE 23/12Z ECMWF WANTS TO KEEP IT DRIER. RIGHT NOW WILL KEEP DECENT CONSISTENCY WITH PREVIOUS FORECAST WITH MORE SHOWERY TYPE ACTIVITY. TEMPERATURES FOR WEDNESDAY LOOK TO BE COOLER ALTHOUGH THIS WILL BE HIGHLY DEPENDENT ON CLOUD COVER. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE GUIDANCE IS STILL A BIT DIVERGENT IN THE BEGINNING OF THE LONG TERM PERIOD. THE 24/00Z GFS/GEM WANTS TO HOLD ON TO THE BOUNDARY AND SURFACE LOW A BIT LONGER THAN THE 23/12Z ECMWF FOR WEDNESDAY NIGHT. THEN WE WILL SEE ANOTHER STRONG UPPER LEVEL DISTURBANCE ACROSS THE GREAT LAKES CONTINUE TO PROGRESS EAST. ALL THE LONG RANGE GUIDANCE INDICATES THIS MOVING EAST BUT WITH SLIGHT DIFFERENCES IN TIMING. GENERALLY IT LOOKS LIKE THIS SYSTEM WILL BEGIN PROGRESSING INTO THE REGION THURSDAY AFTERNOON. RIGHT NOW THE GUIDANCE ALSO WANTS INDICATE THIS UPPER LEVEL LOW BECOMING QUASI- STATIONARY GENERALLY ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS WOULD KEEP THE REGION IN A ACTIVE PATTERN THROUGH MUCH OF THE LONG TERM PERIOD. THIS QUASI-STATIONARY TROUGH SETUP IS ALSO GENERALLY SUPPORTED BY THE 23/12Z GFS/ECMWF RESPECTIVE ENSEMBLE MEAN. HIGH AND LOW TEMPERATURES FOR THE PERIOD WILL GENERALLY BE NEAR NORMAL. && .AVIATION /17Z MONDAY THROUGH FRIDAY/... NEAR TERM: VRBL CONDS ACROSS THE AREA THIS AM W/ SOME IFR IN FOG ACROSS THE N TO VFR CONDS ACROSS THE S. EXPECT FOG TO DISSIPATE ERLY THIS AM W/ PREDOM VFR CONDS TDY EXPECT OCNL MVFR TO BRIEF IFR PSBL IN ANY SHOWERS/TSTMS. FOG WILL AGAIN BE A THREAT TNGT ALONG W/ A CONTD CHC OF SHOWERS AND PSBL THUNDER... SHORT TERM: MOST SITES LOOK TO STAY VFR THROUGH THE PERIOD WITH THE EXCEPTION OF THOSE SITES THAT RECEIVE SHOWER AND THUNDERSTORM ACTIVITY. THIS WILL BE MORE LIKELY FOR THE NORTHERN SITES. && .MARINE... NEAR TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THRU TONIGHT. VISIBILITIES COULD BE REDUCED IN PATCHY FOG TODAY AND IN MORE WDSPRD AREAS OF FOG TNGT. SHORT TERM: MARINE: NO HEADLINES EXPECTED AT THIS TIME WITH SEAS GENERALLY STAYING 2 TO 4 FT AND WINDS 10 TO 15 KT. VISIBILITIES COULD BE REDUCED WITH SHOWERS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...KHW/MCW SHORT TERM...JORDAN LONG TERM...JORDAN AVIATION...KHW/MCW/JORDAN MARINE...KHW/MCW/JORDAN
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
412 PM CDT Mon Jun 24 2013 .SHORT TERM...(This Evening through Tuesday Night) Issued at 355 PM CDT MON JUN 24 2013 Main concern will be with potential for convection again tonight and then increasing heat conditions Tuesday. Latest HRRR model shows shortwave trough in synoptic flow to hold together as it moves into eastern Kansas. Dynamics are fairly weak as this is just a ripple in the nearly zonal flow over the region. However...there is some modest instability and potential for a decent LLJ late tonight....so another nocturnal MCS could move through...especially in northern zones where mid level lapse rates favor better instability. On Tuesday...there still is a chance in the afternoon in the northern zones for some convection to fire as yet another very weak short wave trough moves through. Also of concern is what might be left over in terms of outflow boundaries from any activity tonight. Therefore...will keep a chance in the northern zones for tomorrow. Meanwhile the thermal ridge begins to build to the west with 850mb temperatures into the middle and upper 20s deg C in western and central kansas. As this thermal ridge moves towards the area...we will see heat indices begin to edge up to low 100s. Will not issue advisory for Tuesday but have mentioned it in the hazardous weather outlook. Tuesday night...yet another chance for some nocturnal MCS activity mainly in the northeastern zones as the thermal ridge axis moves over the western areas and should limit convection there. .LONG TERM...(Wednesday through Monday) Issued at 355 PM CDT MON JUN 24 2013 Beginning in the middle of the work week, the flattened zonal flow across the nation will begin to amplify as the prevailing westerlies begin to buckle across the U.S.A./Canadian border. The buckling in the flow will be lead by a weak shortwave Wednesday, with our region quickly finding itself in the the northwest flow as the ridge axis of the amplifying ridge pops up to to our west. However, as the weekend arrives the trough across the Great Lakes will gather some energy, expanding enough to possibly but much of our forecast area on the cool side of the still prevailing northwest flow. The pattern for the week will dictate hot and humid conditions through the middle of the work week, with Wednesday and Thursday being particularly muggy and troublesome. Dew points will be critical mid-week on determining the need for a heat advisory as heat indices will be ranging in the low 100s. Currently, forecast numbers are coming up just shy of criteria, though this currently looks due to the fact that afternoon dew points will likely mix out a little as the hot air advecting in aloft from the southwest will also be a bit dry. By Friday...temperatures are expected to back off a little from the hot and humid readings of the previous few days as the trough over the Great Lakes begins to dominate the eastern CONUS. Readings for Friday will still reach in the 90s, but the humidity wont be as bad; and for the weekend temperatures should range through the 80s. As for precipitation, only true potential for more than isolated storms looks to be focused on Thursday night into Friday morning as the edge of the Great Lakes trough begins pushing back to the southwest. Have kept POPs in the chance category owing to the vagaries of forecast timing in a northwest flow. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon) Issued at 1221 PM CDT MON JUN 24 2013 An outflow boundary has moved through STJ and MCI temporarily shifting winds to the NW however winds should back to the south by 19Z. Thunderstorms will be possible over STJ through 19Z with no cig/vis restrictions. These storms will skirt MCI and there may be a bit of development along the outflow boundary continuing the chance for a thunderstorm at MCI, thusly have left VCTS in the MCI TAF through 19Z. MKC should remain dry. Beyond the 19Z period, conds should remain VFR at the terminals with gusty winds out of the south through tonight. Gusts will diminish overnight but winds will remain out of the south between 10-15kts. Winds will become gusty again by mid morning tomorrow with sustained winds between 15-20kts and gusts 25-30kts. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ SHORT TERM...Adolphson/73 LONG TERM...Cutter AVIATION...73
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
611 PM EDT MON JUN 24 2013 .SYNOPSIS... HIGH PRESSURE OFF THE MIDDLE ATLANTIC COAST WILL CONTINUE TO BRING A SOUTHERLY FLOW OF WARM AND HUMID AIR TO THE AREA THROUGH MID WEEK. A WEAK COLD FRONT WILL STALL TO OUR NORTH ACROSS THE CENTRAL GREAT LAKES TUESDAY. A STRONGER COLD FRONT WILL MOVE ACROSS THE REGION THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... BAND OF AFTERNOON CONVECTION LOST SUPPORT AND DISSIPATED ABOUT HALFWAY ACROSS THE CWA. AIRMASS REMAINS SOMEWHAT UNSTABLE THE REST OF THE NIGHT. HRRR AND RUC SHOW SOME OF THE CONVECTION OVER LWR MI WITH A VERY WEAK S/W WORKING ESE INTO THE LERI AREA THIS EVENING THEN SOME PART OF THE COMPLEX OVER NW IL MAKING IT AROUND THE LERI AREA AROUND MIDNIGHT OR SO. WILL KEEP CHANCE POPS GOING BUT TRY AND DEPICT SOME BETTER TIMING. LOWS WILL BE ABOVE GUIDANCE BY A DEGREE OR TWO. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... NEW DAY...SAME CONCERNS. UPPER FLOW IS NOW FAIRLY ZONAL THANKS TO THE FLATTENING RIDGE. MODELS SHOW AN UPPER TROF DEVELOPING TO OUR WEST BY WEDNESDAY AND THEN MOVING INTO THE REGION THURSDAY. IT THEN GETS TRAPPED IN THE AREA AND THEN REINFORCED FOR THE WEEKEND BUT THAT WILL BE COVERED IN THE SECTION BELOW. FOR TUESDAY MODELS SHOW CONTINUED DEEP MOISTURE ACROSS THE AREA WITH WEAK DISTURBANCES ALOFT MOVING THROUGH THE AREA. EXPECTING MORE COVERAGE THAN TODAY AND WILL HAVE LIKELY TO HIGH CHANCE ACROSS THE NORTHERN TIER OF COUNTIES WITH 30-40% SOUTH. TUESDAY NIGHT INTO WEDNESDAY MODELS SHOW THICKNESS PACKING NORTHWEST TO SOUTHEAST ACROSS THE AREA WITH THE LIKELY GENERATION POINT FOR MCS DEVELOPMENT TO OUR NORTHWEST. CONCERNED THAT WE HAVE CONVECTION MOVE INTO THE AREA TUESDAY NIGHT FROM THE NORTHWEST LASTING INTO WEDNESDAY. WILL HAVE LIKELY POPS NORTHWEST PA AND NERN OHIO AND MID/HIGH CHANCE ELSEWHERE TUESDAY NIGHT AND EARLY WEDNESDAY. LAKE WEDNESDAY WILL HAVE LIKELY POPS MOVING IN FROM THE NORTHWEST WITH APPROACHING UPPER TROF. THURSDAY AN UPPER TROF REMAINS OVER THE AREA WITH DEEP MOISTURE STILL IN PLACE SO WILL CONTINUE LIKELY POPS CENTRAL AND EAST WITH CHANCE POPS WEST. TEMPS WELL ABOVE NORMAL THROUGH MID WEEK AND THEN NEAR NORMAL THURSDAY. && .LONG TERM /FRIDAY THROUGH MONDAY/... UPPER LEVEL TROUGH DIGS INTO THE CENTRAL GREAT LAKES ON FRIDAY THEN AMPLIFIES AS IT SLOWLY PIVOTS EAST OVER THE WEEKEND. THIS WILL CAUSE LOW PRESSURE AT THE SURFACE TO RETROGRADE TO THE WEST WITH A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS WITHIN THE BROAD CYCLONIC FLOW THROUGH AT LEAST SATURDAY. WILL CARRY A 30-50 PERCENT POP FOR FRIDAY AND SATURDAY WITH A DECREASING TREND FOR SUNDAY AS DRIER AIR GETS WRAPPED INTO THE SYSTEM FROM THE WEST. HIGHS WILL BE NEAR NORMAL ON FRIDAY...AROUND 80...BEFORE DROPPING BACK INTO THE 70S OVER THE WEEKEND. ADJUSTED HIGHS DOWN SEVERAL DEGREES FOR SATURDAY/SUNDAY CLOSER TO RAW MODEL VALUES INSTEAD OF MEX GUIDANCE WHICH IS LIKELY RUNNING TOO HIGH AS IT TRENDS TOWARDS CLIMO IN THE LATER PERIODS. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... SCATTERED THUNDERSTORMS HAVE DEVELOPED ALONG A BOUNDARY EXTENDING FROM NEAR DETROIT TO WEST OF MANSFIELD AND COLUMBUS. THESE THUNDERSTORMS ARE MOVING NORTHEAST AT APPROXIMATELY 20 MPH AND HAVE TRIED TO TIME INTO THE TERMINALS BETWEEN 18-00Z EXCEPT FDY/ERI WHERE CHANCES LOOK TO0 LOW. ANY THUNDERSTORM THAT REACHES A TERMINAL MAY PRODUCE BRIEF HEAVY RAIN AND WIND GUSTS UP TO 35 KNOTS. VFR CONDITIONS EXPECTED TO PERSIST OUTSIDE OF THUNDERSTORMS. TRYING TO TIME ANY ADDITIONAL SHOWERS AND THUNDERSTORMS FOR LATER IN THE TAF PERIOD IS DIFFICULT AND WILL DEPEND ON LEFT OVER BOUNDARIES AND EVOLUTION OF UPSTREAM ACTIVITY. MODELS SUGGEST ANOTHER ROUND OF SHOWERS AND SCATTERED THUNDERSTORMS MAY TRY TO MOVE SOUTHEAST OUT OF MICHIGAN EARLY TUESDAY MORNING AND ADDED SHOWERS INTO THE MORE FAVORED LOCATIONS. ALSO INCLUDED MVFR HZ/BR AT A FEW SITES BETWEEN 10-13Z GIVEN THE HIGH HUMIDITY. .OUTLOOK...NON-VFR IN SCATTERED SHOWERS/THUNDERSTORMS AND EARLY MORNING MIST/HAZE THROUGH SATURDAY. && .MARINE... SOUTHWEST FLOW WILL CONTINUE ON THE LAKE AHEAD OF LOW PRESSURE THAT WILL EVENTUALLY APPROACH LATE WEDNESDAY FROM THE PLAINS. SPEEDS WILL INCREASE TO 10-20 KNOTS FOR A PERIOD OF TIME BEFORE SLOWLY VEERING TO THE NORTHWEST THURSDAY AND FRIDAY AS THE LOW SHIFTS TO THE EASTERN GREAT LAKES. TIMING OF THUNDERSTORMS WILL BE DIFFICULT OVER THE NEXT SEVERAL DAYS WITH MULTIPLE ROUNDS OF CONVECTION EXPECTED...ESPECIALLY FROM TUESDAY THROUGH THURSDAY. THUNDERSTORMS HAVE THE POTENTIAL TO BE STRONG GIVEN THE HOT AND HUMID AIRMASS OVER THE REGION. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...TK NEAR TERM...TK/ADAMS SHORT TERM...TK LONG TERM...KEC AVIATION...KEC MARINE...KEC
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
324 PM EDT MON JUN 24 2013 .SYNOPSIS... DISTURBANCES EMBEDDED IN ZONAL FLOW WILL CONTINUE TO INTERACT WITH A WARM AND UNSTABLE AIRMASS TO BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE AREA THROUGH MID WEEK. AN APPROACHING COLD FRONT WILL BRING INCREASING CHANCES FOR PRECIPITATION STARTING WEDNESDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... ZONAL FLOW HAS DEVELOPED ALOFT ACROSS THE OHIO VALLEY TODAY. A WEAKENING COMPLEX OVERNIGHT ASSOCIATED WITH A DISTURBANCE EMBEDDED IN THE ZONAL FLOW BROUGHT A CONVERGENT LOW LEVEL BOUNDARY TO THE AREA LATE THIS MORNING AND HAS BEEN THE FOCUS FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THIS ACTIVITY WILL CONTINUE EASTWARD AND APPEARS THAT IT WILL REACH THE EASTERN EDGE OF THE FORECAST AREA BY THIS EVENING. A LOT OF UNCERTAINTY IS LEFT BEHIND THIS DEPARTING BAND OF CONVECTION...WITH SKIES CLEARING ACROSS THE NORTHWESTERN HALF OF OF THE ILN AREA THIS AFTERNOON. A DECAYING MCV ACROSS NORTHERN INDIANA MAY ACT AS A FOCUS FOR ADDITIONAL CONVECTION ACROSS NORTHERN INDIANA LATE THIS AFTERNOON...AS THE ATMOSPHERE DESTABILIZES IN THE WAKE OF THIS MORNINGS CLOUD COVER. LAPS SOUNDINGS SHOW UP TO 3000 J/KG SFC BASED CAPE JUST TO THE WEST OF OUR NORTHWESTERN ZONES...WITH THE RAP INDICATING THAT DESTABILIZATION WILL CONTINUE INTO THE AFTERNOON AND EARLY EVENING. THE BIG QUESTION BECOMES HOW MUCH FORCING WILL THERE BE FROM THE DECAYING MCV...IF ANY...TO PRODUCE CONVECTION LATE THIS AFTERNOON. WITH THIS UNCERTAINTY IN MIND...AM FORECASTING CHANCE POPS TO MOVE INTO OUR NORTHWESTERN ZONES LATE THIS AFTERNOON AND EVENING...IN CASE THIS CONVECTION DOES INITIATE. ANY CONVECTION THAT DOES DEVELOP WILL LIKELY DIMINISH AROUND SUNSET AS LOW LEVEL FLOW REMAINS WEAK ACROSS OUR AREA...NOT SUPPORTIVE OF NOCTURNAL CONVECTION. SOME CONVECTION WILL PROBABLY REMAIN ONGOING TO OUR NORTH AND NORTHWEST TONIGHT...WHERE LOW TO MID LEVEL FLOW IS STRONGER. TONIGHT WILL BE ANOTHER WARM ONE WITH THE WARM AND HUMID AIRMASS IN PLACE. WENT JUST BELOW GUIDANCE BASED ON BIASES FOR THE PAST COUPLE OF NIGHTS...WITH SOME A WARM BIAS IN THE MODELS BEING NOTICED IN OUR TYPICALLY COOLER VALLEYS. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... ANOTHER DISTURBANCE WILL FOLLOW IN THE WAKE OF TODAYS DISTURBANCE ON TUESDAY. LATEST RAP/NAM/ARW INDICATE THIS DISTURBANCE WILL BE CROSSING SOUTHERN LAKE MICHIGAN EARLY TUESDAY. THE QUESTION IS HOW ARE MODELS HANDLING SOME WARMER AIR ALOFT MOVING INTO THE REGION...AND ITS AFFECT ON A DEVELOPING A CAP ACROSS OUR AREA TUESDAY. MOST MODELS ARE INDICATING A WEAK CAP AROUND 5 KFT AGL BASICALLY SOUTH OF INTERSTATE 70 ON TUESDAY...WHICH WOULD LIMIT AND CONVECTION FROM INITIATING AS THE DISTURBANCE PASSES TO OUR NORTH TUESDAY AFTERNOON. THE NAM/SREF DO NOT BUY INTO THIS SOLUTION...AND HAVE A MUCH WEAKER...AND BREAKABLE CAP IN PLACE. BASED ON THE INHERENT UNCERTAINTIES IN THIS CURRENT CONVECTIVE REGIME...AND THE FACT THAT A GOOD DEAL OF LOW LEVEL MOISTURE IS IN PLACE...CANNOT RULE OUT CONVECTION IN THE SOUTH TUESDAY. WENT WITH CHANCE POPS FOR ALL ZONES WITH 30 POPS IN THE SOUTH AND 40 POPS MAINLY NORTH OF INTERSTATE 70. HIGH TEMPERATURES...BARRING ANY DEBRIS CLOUDS TO START OFF WITH...WILL RISE INTO THE UPPER 80S TO LOWER 90S DURING THE AFTERNOON. UNCERTAINTY INCREASES EVEN FURTHER GOING INTO TUESDAY NIGHT...WITH ADDITIONAL CONVECTION POSSIBLE MAINLY ACROSS THE NORTH AS UPPER LEVEL ENERGY IMPULSES CONTINUE TO MOVE WEST TO EAST IN THE ZONAL FLOW. KEPT POPS IN THE SLIGHT CHANCE TO CHANCE RANGE FOR NOW...IN CASE SOME OF THIS CONVECTION MAKES IT INTO OUR FORECAST AREA DURING THE OVERNIGHT TIME PERIOD. ANOTHER WARM NIGHT WILL RESULT WITH THE CONTINUED WARM AIRMASS. AM ANTICIPATING ENHANCED CLOUD COVER TUESDAY NIGHT WITH SOME CONVECTION TO OUR NORTH...AND POSSIBLE RETURN FLOW CONTINUING INTO THE NIGHT. TEMPERATURES MAY ONLY BOTTOM OUT IN THE LOWER 70S ACROSS MANY OF OUR ZONES...EXCEPT FOR PERHAPS THE RURAL EASTERN ZONES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... THERE ARE SOME MODEL DISCREPANCIES AS TO HOW MUCH IF ANY PCPN WILL BE ONGOING WEDNESDAY MORNING. WILL TREND TOWARD A DRIER FORECAST AT THE ONSET BUT HANG ON TO SOME LOWER POPS JUST TO COVER THE THREAT. ASSUMING THERE ARE NOT TOO MANY LINGERING DEBRIS CLOUDS...WE SHOULD THEN BE ABLE TO DESTABILIZE NICELY THROUGH THE AFTERNOON IF TEMPERATURES CAN PUSH INTO THE UPPER 80S TO NEAR 90. THIS WOULD RESULT IN ML CAPE VALUES IN THE 2000 TO POSSIBLY 3000 J/KG RANGE. THE COMBINATION OF THIS AND SHORT WAVE ENERGY MOVING DOWN ACROSS THE WESTERN GREAT LAKES INTO OUR AREA WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT...SHOULD LEAD TO A DECENT CHANCE OF THUNDERSTORMS PUSHING IN FROM THE NORTHWEST LATE IN THE DAY. WITH INCREASING DYNAMICS ACROSS THE AREA AND FAVORABLE TIMING...THERE IS THE POSSIBILITY OF SOME SEVERE STORMS...ESPECIALLY LATE WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING. PCPN CHANCES WILL THEN CONTINUE INTO THURSDAY AS THE COLD FRONT MOVES THROUGH. HIGHEST POPS FOR THURSDAY WILL BE ACROSS OUR EAST/SOUTHEAST...CLOSER TO THE UPPER LEVEL TROUGH AND WHERE THE COLD FRONT WILL BE LAST TO MOVE THROUGH. BUILDING RIDGE OVER THE WESTERN UNITED STATES WILL CONTINUE TO CARVE OUT A TROUGH ACROSS THE EAST THROUGH THE REMAINDER OF THE LONG TERM PERIOD. THIS WILL KEEP TEMPERATURES FAIRLY SEASONABLE FRIDAY THROUGH MONDAY WITH HIGHS GENERALLY IN THE LOWER 80S. MODELS ARE SHOWING VARIOUS WEAK SHORT WAVES PROGRESSING THROUGH THE TROUGH BUT IT IS TOUGH TO PINPOINT ANY KIND OF TIMING. AS A RESULT...WITH THE UPPER LEVEL TROUGH IN PLACE AND GIVEN THE TIME OF YEAR...THINK THE BEST WAY TO GO IS TO TREND THE POPS DIURNAL BUT KEEP THEM ON THE LOW SIDE THROUGH THE WEEKEND. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... CONVECTION WILL AFFECT TAF SITES THIS AFTERNOON INTO THIS EVENING. IT APPEARS THAT CMH AND LCK WILL SEE A CLUSTER OF THUNDERSTORMS EARLY THIS AFTERNOON. OTHER CONVECTION AIDED BY AN UPPER AIR TROUGH MAY DEVELOP AND IMPACT OTHER TAF SITES...WHICH WILL THEN DIE DOWN WITH LOSS OF DAYTIME HEATING. BR IS EXPECTED LATE TONIGHT AT LUK AND ILN. LACK OF UPPER SUPPORT MAY LIMIT CONVECTIVE FORMATION ON TUESDAY. OUTLOOK...SHOWERS AND THUNDERSTORMS WILL OCCUR FROM WEDNESDAY AFTERNOON THROUGH THURSDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...LATTO NEAR TERM...LATTO SHORT TERM...LATTO LONG TERM...JGL AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
704 PM EDT MON JUN 24 2013 .SYNOPSIS... A BERMUDA HIGH WILL REMAIN IN PLACE OFF THE ATLANTIC COAST THROUGH THE WEEK...DRIVING PERSISTENT MOIST SOUTHERLY FLOW INTO THE REGION. AFTERNOON SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY EACH DAY. A COLD FRONT PASSAGE OVER THE WEEKEND WILL BRING AN INCREASE IN RAIN CHANCES AND SLIGHTLY COOLER TEMPERATURES BEFORE CLEARING THE AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH TUESDAY/... AS OF 700 PM EDT MONDAY...OUTFLOW BNDRYS ARE WORKING INTO THE UPSTATE AND NE GA FROM THE SOUTH...TRIGGERING SOME CONVECTION IN THEIR WAKE. THERE IS ALSO SOME ACTIVITY ALONG THE BLUE RIDGE...ESPECIALLY UP IN NORTH CAROLINA. I TRIMMED POPS BACK ACROSS THE WRN NC PIEDMONT AND THE ERN FOOTHILLS AND THE NE PIEDMONT OF SOUTH CAROLINA. SINCE THESE AREAS WERE WORKED OVER BY CONVECTION THEY SHOULD ENJOY A QUIET EVENING. HOWEVER...LATER TONIGHT WE MAY SEE CONVECTION DEVELOP ONCE AGAIN AS THE SEA BREEZE FRONT PUSHES IN FROM THE SOUTH BETWEEN ABOUT MIDNIGHT AND 2 AM. LAST NIGHT THIS HELPED TO KICK OFF SHOWERS AND STORMS...AND IF SOMETHING DOESN/T WORK OVER THE SRN PART OF THE SC/GA PARTS OF THE FA...I/D EXPECT TO SEE SOMETHING LIKE THAT AGAIN. AS OF 435 PM EDT MONDAY...STRONG TO SEVERE STORMS ARE CONTINUING ALONG THE I-40 CORRIDOR OF NORTH CAROLINA. OVER THE UPSTATE..NE GA AND MOST OF THE NC MTNS ITS GENERALLY QUIET RIGHT NOW. HOWEVER...THE AIRMASS IS QUITE UNSTABLE OVER THIS AREA AND AS OUTFLOW BNDRYS WORK IN FROM THE SOUTH AND WEST WE SHOULD SEE MORE DEVELOPMENT INTO THE EARLY EVENING HOURS. THEREFORE I HAVE POPS RAMPING BACK UP INTO THE THE HIGH CHANCE RANGE IN A COUPLE HOURS. AS OF 225 PM EDT...COVERAGE OF SHOWERS AND THUNDERSTORMS REMAINS FAIRLY HIGH ACROSS THE ERN HALF OF THE CWFA IN THE LOWER 70S DEWPOINT AIR EAST OF THE MOUNTAINS. WITH SFC BASED CAPE VALUES IN THE 2000 TO 3000 J/KG RANGE ACROSS MUCH OF THE REGION...ANTICIPATE ADDITIONAL DEVELOPMENT ON EARLIER OUTFLOWS...AND NEW DEVELOPMENT ACROSS THE MOUNTAINS IN WEAK BL CONVERGENCE AND LIGHT SW UPSLOPE. A FEW SEVERE STORMS REMAIN POSSIBLE GIVEN THE INSTABILITY...BUT DCAPE VALUES ARE GENERALLY 900 J/KG OR LESS AND PROFILES FAIRLY MOIST...SO IT WILL TAKE VERY TALL STORMS. WILL FEATURE MAINLY SOLID CHC TO LOW LIKELY POPS FOR THE LATE AFTN HOURS...EXCEPT CATEGORICAL ON THE ERN FRINGE. UPPER FORCING WILL SLOWLY IMPROVE THROUGH THE PERIOD AS H5 TROUGHINESS CONTINUES ALONG THE SRN APPALACHIANS...WITH WEAK UPPER DIVERGENCE SETTING UP OVER THE MTNS THROUGH TUE. LOW LEVEL SW FLOW SHOULD PROVIDE SOME UPSLOPE ENHANCEMENT IN THE SW MTNS WHERE CHC POPS WILL BE KEPT GOING THE LONGEST TONIGHT. SIGNALS ARE MIXED ON LOW STRATUS DEVELOPMENT TUE MORNING GIVEN A MORE SW TO W DIRECTION IN THE BL FLOW VERSUS THE SRLY WINDS OBSERVED THIS MORNING. EXPECT MIN TEMPS TO BE QUITE WARM. THE UPPER FORCING...PWAT IN PROFILES AROUND 1.75 INCHES...AND A DEVELOPING LEE TROUGH SHOULD GET LIKELY COVERAGE GOING AGAIN EARLY ON TUESDAY...WITH SIMILAR HAZARDS OF LOCALLY HEAVY RAINFALL AND AN ISOLD SEVERE THREAT. THICKNESSES SUPPORT VERY WARM TEMPS NEAR 90 TUE AFTN IN THE PIEDMONT...BUT CLOUD COVER AND PRECIP SHOULD CURB THAT SOMEWHAT. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... AS OF 230 PM MONDAY...THE SHORT TERM PERIOD LOOKS RATHER ACTIVE...HIGHLIGHTED BY A SERIES OF UPPER LEVEL IMPULSES AIDING IN DIURNAL CONVECTION...AND AN UPPER TROF DIVING THROUGH THE OHIO VALLEY THROUGH THE END OF THE PERIOD. TUESDAY EVENING A PERSISTENT BERMUDA HIGH WILL CONTINUE TO PROMOTE SOUTHERLY FLOW. MID TO UPPER 60S DEWPOINTS AND SURFACE TEMPERATURES IN THE 80S WILL CONTINUE TO ALLOW FOR ENOUGH INSTABILITY FOR CONVECTION INTO THE EVENING HOURS. THUS...KEPT SOLID CHANCE POPS THROUGH SUNSET. MEANWHILE...UPPER LEVEL PATTERN BEGINS TO AMPLIFY SOMEWHAT AS TROF DEEPENS ACROSS THE UPPER MIDWEST. AS THE DISTURBANCE MOVES EASTWARD THROUGH THE GREAT LAKES REGION ON WEDNESDAY...HEIGHTS ACROSS NORTHEAST GEORGIA AND THE CAROLINAS WILL BEGIN TO FALL. AS FLOW AT THE SURFACE REMAINS SOUTHERLY...AND HEIGHTS FALL ALOFT...EXPECTING SOME RATHER WIDESPREAD CONVECTION TO OCCUR WEDNESDAY AFTERNOON. BOTH GFS AND NAM FORECAST SOUNDINGS INDICATE SUBSTANTIAL DRYING IN THE MID LEVELS INTO THE AFTERNOON HOURS THUS STEEPENING LAPSE RATES. LIKEWISE...SBCAPE VALUES NEARING 1500-2000J/KG CANNOT BE RULED OUT...ESPECIALLY ACROSS THE HIGHER TERRAIN AND THE UPSTATE OF SC. KEPT HIGH END CHANCE POPS ACROSS THE ENTIRE REGION WITH SLIGHTLY HIGHER POPS OVER THE ABOVE MENTIONED AREAS. WITH ALL THAT SAID...SHEAR PROFILES LOOK RATHER BLEAK AS FLOW THROUGH THE COLUMN IS WEAK. THUS NOT EXPECTING ANY ROTATING STORMS...LEADING TO A MORE DAMAGING WIND...LARGE HAIL...AND HEAVY RAINFALL THREAT. MOST IF NOT ALL CONVECTION SHOULD CEASE BY NEAR OR SLIGHTLY AFTER SUNSET ON WEDNESDAY EVENING AS DIURNAL HEATING IS LOST. TEMPERATURES WILL BE SLIGHTLY ABOVE NORMAL FOR MOST AREAS ON WEDNESDAY. AS THE UPPER TROF DIGS OUT ACROSS THE OHIO AND TENNESSEE RIVER VALLEYS ON THURSDAY...UPPER LEVEL HEIGHTS WILL FALL FURTHER...AND A SURFACE COLD FRONT WILL BE MOVING CLOSER TO THE REGION. EXPECTING MUCH OF THE SAME ON THURSDAY AS SURFACE HEATING AND MODEST DEWPOINTS WILL ALLOW FOR SUBSTANTIAL CAPE. HOWEVER ALTHOUGH NOT THAT HIGH...THURSDAY WILL YIELD MORE SHEAR THAN WEDNESDAY AS THE TROF BASE SWINGS THROUGH...AND THE COLD FRONT APPROACHES. THIS WILL LEAD TO AT LEAST SOME POTENTIAL FOR BETTER CONVECTIVE ORGANIZATION. LOOK FOR THE MAIN THREATS ON THURSDAY TO BE DAMAGING WINDS...LARGE HAIL...AND HEAVY RAINFALL. CONVECTION WILL LIKELY BE MOST INTENSE ALONG AND AHEAD OF THE FRONT DURING THE AFTERNOON HOURS. WENT WITH LIKELY POPS EARLY IN THE DAY ACROSS THE HIGHER TERRAIN AND SOLID CHANCE POPS ELSEWHERE. TEMPERATURES ON THURSDAY WILL BE AT OR SLIGHTLY BELOW NORMAL AS THUNDERSTORM DEVELOPMENT WILL PLAY A MAJOR ROLE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 200 PM MONDAY...THE EXTENDED PERIOD BEGINS WITH THE CWA ON THE FAR WESTERN PERIPHERY OF A BERMUDA HIGH AND AN UPPER LEVEL TROUGH QUICKLY DEVELOPING OVER THE REGION ON THURSDAY. THE TROUGH DEEPENS OVER THE WEEKEND AND TAKES OVER THE MAJORITY OF THE EASTERN CONUS...WHILE A COLD FRONT APPROACHES WITH THE TROUGH AND THEN STALLS OUT OVER THE AREA FOR THE WEEKEND. THE TROUGH REMAINS THE DOMINANT FEATURE FOR MOST OF THE EXTENDED PERIOD...WITH HIGH PRESSURE ONLY BEGINNING TO BUILD BACK IN TO THE WEST OF THE FORECAST AREA BY EARLY NEXT WEEK. CONVECTION WILL BE MAINLY DIURNAL IN NATURE...WITH ISOLATED TO SCATTERED COVERAGE OVER THE FOOTHILLS AND MOUNTAINS EACH AFTERNOON. THE HIGHEST POPS WILL BE FEATURED EARLY IN THE WEEKEND WITH THE FRONTAL PASSAGE. CLOUD COVER AND THE PERSISTENT UPPER TROUGH WILL KEEP HIGH TEMPERATURES SLIGHTLY COOLER THAN AVERAGE OVER THE WEEKEND...BUT NORTHWESTERLY FLOW FOLLOWING THE FRONT WILL DRY OUT THE AIRMASS AND ALLOW A SLIGHT WARMING TREND BY LATE WEEKEND/EARLY NEXT WEEK. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... AT KCLT...THE TRAINING CLUSTER OF THUNDERSTORMS HAS SET UP MAINLY S TO SE OF THE AIRFIELD THIS AFTN...BUT CLOSE ENOUGH TO CARRY WALL TO WALL THUNDER THROUGH 00Z...WITH TEMPO GUSTS AND MVFR RESTRICTIONS IN ANY HEAVIER RAINFALL. WE COULD SEE ADDITIONAL DEVELOPMENT FROM THE FOOTHILLS LATER THIS AFTN/EVENING PER THE LATEST HRRR RUN. CONFIDENCE IS LOWER ON THAT...SO WILL RAMP DOWN TO A VCSH FOR NOW. CIGS AND VSBY ARE A REAL QUESTION MARK OVERNIGHT...WITH SOME STRATUS LIKELY IN THE LOWER PIEDMONT...BUT WITH SW TO W BL FLOW PROVIDING MUCH LESS OF A PUSH INTO THE TERMINAL AREA. WILL HINT THAT WAY WITH SCT010 BUT KEEP CIGS AND VSBY VFR FOR NOW. EXPECT AN EARLY START TO CONVECTION AGAIN ON TUE WITH VERY MOIST PROFILES AND SLIGHTLY IMPROVING UPPER SUPPORT. ELSEWHERE...THUNDERSTORMS ARE LIKELY AT TIMES AT ALL THE MTN AND FOOTHILLS TAF LOCATIONS THIS AFTN AND EVENING. WILL RIDE ON SOME FAIRLY BROAD VCTS GROUPS FOR NOW...BUT TEMPO WILL LIKELY BE NEEDED AT TIMES LATER ON. EXPECT MAINLY VFR CIGS EXCEPT BRIEF MVFR IN ANY TSTMS ALONG WITH BRIEFLY GUSTY WINDS. SCT SHRA OR TSRA COULD CONTINUE INTO THE OVERNIGHT HOURS...BUT WITH THE BEST FOCUS IN SW MTN UPSLOPE AREAS...SO WILL ALLOW COVERAGE TO WANE FOR NOW. MTN VALLEY FOG/CIG PROBLEMS LOOK LIKELY...WITH IFR AT KAVL BY 08Z. EAST OF THE MTNS...CONFIDENCE IS LOWER GIVEN THE SW TO W BL FLOW. SOME STRATUS SEEMS LIKELY TOWARD DAYBREAK...AND POSSIBLY VSBY ISSUES IF THE TERMINALS SEE HEAVY RAINFALL LATE TODAY. EXPECT ANOTHER EARLY START TO CONVECTION ON TUE WITH THE AIRMASS REMAINING VERY MOIST. OUTLOOK...EXPECT UNSETTLED WEATHER AT THE TERMINAL LOCATIONS THROUGH THE WEEK...WITH UPPER TROUGHINESS PERSISTING AND THEN DEEPENING MID TO LATE WEEK. THIS SHOULD LEAD TO MORNING FOG/STRATUS RESTRICTIONS...WITH MAINLY AFTN/EVENING TSRA EACH DAY. CONFIDENCE TABLE... 23-05Z 05-11Z 11-17Z 17-23Z KCLT HIGH 100% HIGH 98% HIGH 86% MED 60% KGSP HIGH 100% HIGH 97% HIGH 100% HIGH 80% KAVL HIGH 100% MED 65% MED 66% MED 75% KHKY HIGH 100% HIGH 98% HIGH 95% HIGH 100% KGMU HIGH 100% HIGH 97% HIGH 98% HIGH 80% KAND HIGH 100% HIGH 100% HIGH 90% HIGH 80% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...VISIN NEAR TERM...HG/MCAVOY SHORT TERM...CDG LONG TERM...VISIN AVIATION...HG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
509 PM EDT MON JUN 24 2013 .SYNOPSIS... A BERMUDA HIGH WILL REMAIN IN PLACE OFF THE ATLANTIC COAST THROUGH THE WEEK...DRIVING PERSISTENT MOIST SOUTHERLY FLOW INTO THE REGION. AFTERNOON SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY EACH DAY. A COLD FRONT PASSAGE OVER THE WEEKEND WILL BRING AN INCREASE IN RAIN CHANCES AND SLIGHTLY COOLER TEMPERATURES BEFORE CLEARING THE AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH TUESDAY/... AS OF 435 PM EDT MONDAY...STRONG TO SEVERE STORMS ARE CONTINUING ALONG THE I-40 CORRIDOR OF NORTH CAROLINA. OVER THE UPSTATE..NE GA AND MOST OF THE NC MTNS ITS GENERALLY QUIET RIGHT NOW. HOWEVER...THE AIRMASS IS QUITE UNSTABLE OVER THIS AREA AND AS OUTFLOW BNDRYS WORK IN FROM THE SOUTH AND WEST WE SHOULD SEE MORE DEVELOPMENT INTO THE EARLY EVENING HOURS. THEREFORE I HAVE POPS RAMPING BACK UP INTO THE THE HIGH CHANCE RANGE IN A COUPLE HOURS. AS OF 225 PM EDT...COVERAGE OF SHOWERS AND THUNDERSTORMS REMAINS FAIRLY HIGH ACROSS THE ERN HALF OF THE CWFA IN THE LOWER 70S DEWPOINT AIR EAST OF THE MOUNTAINS. WITH SFC BASED CAPE VALUES IN THE 2000 TO 3000 J/KG RANGE ACROSS MUCH OF THE REGION...ANTICIPATE ADDITIONAL DEVELOPMENT ON EARLIER OUTFLOWS...AND NEW DEVELOPMENT ACROSS THE MOUNTAINS IN WEAK BL CONVERGENCE AND LIGHT SW UPSLOPE. A FEW SEVERE STORMS REMAIN POSSIBLE GIVEN THE INSTABILITY...BUT DCAPE VALUES ARE GENERALLY 900 J/KG OR LESS AND PROFILES FAIRLY MOIST...SO IT WILL TAKE VERY TALL STORMS. WILL FEATURE MAINLY SOLID CHC TO LOW LIKELY POPS FOR THE LATE AFTN HOURS...EXCEPT CATEGORICAL ON THE ERN FRINGE. UPPER FORCING WILL SLOWLY IMPROVE THROUGH THE PERIOD AS H5 TROUGHINESS CONTINUES ALONG THE SRN APPALACHIANS...WITH WEAK UPPER DIVERGENCE SETTING UP OVER THE MTNS THROUGH TUE. LOW LEVEL SW FLOW SHOULD PROVIDE SOME UPSLOPE ENHANCEMENT IN THE SW MTNS WHERE CHC POPS WILL BE KEPT GOING THE LONGEST TONIGHT. SIGNALS ARE MIXED ON LOW STRATUS DEVELOPMENT TUE MORNING GIVEN A MORE SW TO W DIRECTION IN THE BL FLOW VERSUS THE SRLY WINDS OBSERVED THIS MORNING. EXPECT MIN TEMPS TO BE QUITE WARM. THE UPPER FORCING...PWAT IN PROFILES AROUND 1.75 INCHES...AND A DEVELOPING LEE TROUGH SHOULD GET LIKELY COVERAGE GOING AGAIN EARLY ON TUESDAY...WITH SIMILAR HAZARDS OF LOCALLY HEAVY RAINFALL AND AN ISOLD SEVERE THREAT. THICKNESSES SUPPORT VERY WARM TEMPS NEAR 90 TUE AFTN IN THE PIEDMONT...BUT CLOUD COVER AND PRECIP SHOULD CURB THAT SOMEWHAT. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... AS OF 230 PM MONDAY...THE SHORT TERM PERIOD LOOKS RATHER ACTIVE...HIGHLIGHTED BY A SERIES OF UPPER LEVEL IMPULSES AIDING IN DIURNAL CONVECTION...AND AN UPPER TROF DIVING THROUGH THE OHIO VALLEY THROUGH THE END OF THE PERIOD. TUESDAY EVENING A PERSISTENT BERMUDA HIGH WILL CONTINUE TO PROMOTE SOUTHERLY FLOW. MID TO UPPER 60S DEWPOINTS AND SURFACE TEMPERATURES IN THE 80S WILL CONTINUE TO ALLOW FOR ENOUGH INSTABILITY FOR CONVECTION INTO THE EVENING HOURS. THUS...KEPT SOLID CHANCE POPS THROUGH SUNSET. MEANWHILE...UPPER LEVEL PATTERN BEGINS TO AMPLIFY SOMEWHAT AS TROF DEEPENS ACROSS THE UPPER MIDWEST. AS THE DISTURBANCE MOVES EASTWARD THROUGH THE GREAT LAKES REGION ON WEDNESDAY...HEIGHTS ACROSS NORTHEAST GEORGIA AND THE CAROLINAS WILL BEGIN TO FALL. AS FLOW AT THE SURFACE REMAINS SOUTHERLY...AND HEIGHTS FALL ALOFT...EXPECTING SOME RATHER WIDESPREAD CONVECTION TO OCCUR WEDNESDAY AFTERNOON. BOTH GFS AND NAM FORECAST SOUNDINGS INDICATE SUBSTANTIAL DRYING IN THE MID LEVELS INTO THE AFTERNOON HOURS THUS STEEPENING LAPSE RATES. LIKEWISE...SBCAPE VALUES NEARING 1500-2000J/KG CANNOT BE RULED OUT...ESPECIALLY ACROSS THE HIGHER TERRAIN AND THE UPSTATE OF SC. KEPT HIGH END CHANCE POPS ACROSS THE ENTIRE REGION WITH SLIGHTLY HIGHER POPS OVER THE ABOVE MENTIONED AREAS. WITH ALL THAT SAID...SHEAR PROFILES LOOK RATHER BLEAK AS FLOW THROUGH THE COLUMN IS WEAK. THUS NOT EXPECTING ANY ROTATING STORMS...LEADING TO A MORE DAMAGING WIND...LARGE HAIL...AND HEAVY RAINFALL THREAT. MOST IF NOT ALL CONVECTION SHOULD CEASE BY NEAR OR SLIGHTLY AFTER SUNSET ON WEDNESDAY EVENING AS DIURNAL HEATING IS LOST. TEMPERATURES WILL BE SLIGHTLY ABOVE NORMAL FOR MOST AREAS ON WEDNESDAY. AS THE UPPER TROF DIGS OUT ACROSS THE OHIO AND TENNESSEE RIVER VALLEYS ON THURSDAY...UPPER LEVEL HEIGHTS WILL FALL FURTHER...AND A SURFACE COLD FRONT WILL BE MOVING CLOSER TO THE REGION. EXPECTING MUCH OF THE SAME ON THURSDAY AS SURFACE HEATING AND MODEST DEWPOINTS WILL ALLOW FOR SUBSTANTIAL CAPE. HOWEVER ALTHOUGH NOT THAT HIGH...THURSDAY WILL YIELD MORE SHEAR THAN WEDNESDAY AS THE TROF BASE SWINGS THROUGH...AND THE COLD FRONT APPROACHES. THIS WILL LEAD TO AT LEAST SOME POTENTIAL FOR BETTER CONVECTIVE ORGANIZATION. LOOK FOR THE MAIN THREATS ON THURSDAY TO BE DAMAGING WINDS...LARGE HAIL...AND HEAVY RAINFALL. CONVECTION WILL LIKELY BE MOST INTENSE ALONG AND AHEAD OF THE FRONT DURING THE AFTERNOON HOURS. WENT WITH LIKELY POPS EARLY IN THE DAY ACROSS THE HIGHER TERRAIN AND SOLID CHANCE POPS ELSEWHERE. TEMPERATURES ON THURSDAY WILL BE AT OR SLIGHTLY BELOW NORMAL AS THUNDERSTORM DEVELOPMENT WILL PLAY A MAJOR ROLE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 200 PM MONDAY...THE EXTENDED PERIOD BEGINS WITH THE CWA ON THE FAR WESTERN PERIPHERY OF A BERMUDA HIGH AND AN UPPER LEVEL TROUGH QUICKLY DEVELOPING OVER THE REGION ON THURSDAY. THE TROUGH DEEPENS OVER THE WEEKEND AND TAKES OVER THE MAJORITY OF THE EASTERN CONUS...WHILE A COLD FRONT APPROACHES WITH THE TROUGH AND THEN STALLS OUT OVER THE AREA FOR THE WEEKEND. THE TROUGH REMAINS THE DOMINANT FEATURE FOR MOST OF THE EXTENDED PERIOD...WITH HIGH PRESSURE ONLY BEGINNING TO BUILD BACK IN TO THE WEST OF THE FORECAST AREA BY EARLY NEXT WEEK. CONVECTION WILL BE MAINLY DIURNAL IN NATURE...WITH ISOLATED TO SCATTERED COVERAGE OVER THE FOOTHILLS AND MOUNTAINS EACH AFTERNOON. THE HIGHEST POPS WILL BE FEATURED EARLY IN THE WEEKEND WITH THE FRONTAL PASSAGE. CLOUD COVER AND THE PERSISTENT UPPER TROUGH WILL KEEP HIGH TEMPERATURES SLIGHTLY COOLER THAN AVERAGE OVER THE WEEKEND...BUT NORTHWESTERLY FLOW FOLLOWING THE FRONT WILL DRY OUT THE AIRMASS AND ALLOW A SLIGHT WARMING TREND BY LATE WEEKEND/EARLY NEXT WEEK. && .AVIATION /21Z MONDAY THROUGH SATURDAY/... AT KCLT...THE TRAINING CLUSTER OF THUNDERSTORMS HAS SET UP MAINLY S TO SE OF THE AIRFIELD THIS AFTN...BUT CLOSE ENOUGH TO CARRY WALL TO WALL THUNDER THROUGH 00Z...WITH TEMPO GUSTS AND MVFR RESTRICTIONS IN ANY HEAVIER RAINFALL. WE COULD SEE ADDITIONAL DEVELOPMENT FROM THE FOOTHILLS LATER THIS AFTN/EVENING PER THE LATEST HRRR RUN. CONFIDENCE IS LOWER ON THAT...SO WILL RAMP DOWN TO A VCSH FOR NOW. CIGS AND VSBY ARE A REAL QUESTION MARK OVERNIGHT...WITH SOME STRATUS LIKELY IN THE LOWER PIEDMONT...BUT WITH SW TO W BL FLOW PROVIDING MUCH LESS OF A PUSH INTO THE TERMINAL AREA. WILL HINT THAT WAY WITH SCT010 BUT KEEP CIGS AND VSBY VFR FOR NOW. EXPECT AN EARLY START TO CONVECTION AGAIN ON TUE WITH VERY MOIST PROFILES AND SLIGHTLY IMPROVING UPPER SUPPORT. ELSEWHERE...THUNDERSTORMS ARE LIKELY AT TIMES AT ALL THE MTN AND FOOTHILLS TAF LOCATIONS THIS AFTN AND EVENING. WILL RIDE ON SOME FAIRLY BROAD VCTS GROUPS FOR NOW...BUT TEMPO WILL LIKELY BE NEEDED AT TIMES LATER ON. EXPECT MAINLY VFR CIGS EXCEPT BRIEF MVFR IN ANY TSTMS ALONG WITH BRIEFLY GUSTY WINDS. SCT SHRA OR TSRA COULD CONTINUE INTO THE OVERNIGHT HOURS...BUT WITH THE BEST FOCUS IN SW MTN UPSLOPE AREAS...SO WILL ALLOW COVERAGE TO WANE FOR NOW. MTN VALLEY FOG/CIG PROBLEMS LOOK LIKELY...WITH IFR AT KAVL BY 08Z. EAST OF THE MTNS...CONFIDENCE IS LOWER GIVEN THE SW TO W BL FLOW. SOME STRATUS SEEMS LIKELY TOWARD DAYBREAK...AND POSSIBLY VSBY ISSUES IF THE TERMINALS SEE HEAVY RAINFALL LATE TODAY. EXPECT ANOTHER EARLY START TO CONVECTION ON TUE WITH THE AIRMASS REMAINING VERY MOIST. OUTLOOK...EXPECT UNSETTLED WEATHER AT THE TERMINAL LOCATIONS THROUGH THE WEEK...WITH UPPER TROUGHINESS PERSISTING AND THEN DEEPENING MID TO LATE WEEK. THIS SHOULD LEAD TO MORNING FOG/STRATUS RESTRICTIONS...WITH MAINLY AFTN/EVENING TSRA EACH DAY. CONFIDENCE TABLE... 20-02Z 02-08Z 08-14Z 14-20Z KCLT HIGH 100% HIGH 100% HIGH 100% MED 79% KGSP HIGH 100% HIGH 100% HIGH 99% HIGH 91% KAVL HIGH 100% HIGH 81% MED 66% MED 69% KHKY HIGH 100% HIGH 100% HIGH 85% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 99% HIGH 91% KAND HIGH 100% HIGH 100% HIGH 94% HIGH 93% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...VISIN NEAR TERM...HG/MCAVOY SHORT TERM...CDG LONG TERM...VISIN AVIATION...HG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
237 PM EDT MON JUN 24 2013 .SYNOPSIS... A BERMUDA HIGH WILL REMAIN IN PLACE OFF THE ATLANTIC COAST THROUGH THE WEEK...DRIVING PERSISTENT MOIST SOUTHERLY FLOW INTO THE REGION. AFTERNOON SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY EACH DAY. A COLD FRONT PASSAGE OVER THE WEEKEND WILL BRING AN INCREASE IN RAIN CHANCES AND SLIGHTLY COOLER TEMPERATURES BEFORE CLEARING THE AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH TUESDAY/... AS OF 225 PM EDT...COVERAGE OF SHOWERS AND THUNDERSTORMS REMAINS FAIRLY HIGH ACROSS THE ERN HALF OF THE CWFA IN THE LOWER 70S DEWPOINT AIR EAST OF THE MOUNTAINS. WITH SFC BASED CAPE VALUES IN THE 2000 TO 3000 J/KG RANGE ACROSS MUCH OF THE REGION...ANTICIPATE ADDITIONAL DEVELOPMENT ON EARLIER OUTFLOWS...AND NEW DEVELOPMENT ACROSS THE MOUNTAINS IN WEAK BL CONVERGENCE AND LIGHT SW UPSLOPE. A FEW SEVERE STORMS REMAIN POSSIBLE GIVEN THE INSTABILITY...BUT DCAPE VALUES ARE GENERALLY 900 J/KG OR LESS AND PROFILES FAIRLY MOIST...SO IT WILL TAKE VERY TALL STORMS. WILL FEATURE MAINLY SOLID CHC TO LOW LIKELY POPS FOR THE LATE AFTN HOURS...EXCEPT CATEGORICAL ON THE ERN FRINGE. UPPER FORCING WILL SLOWLY IMPROVE THROUGH THE PERIOD AS H5 TROUGHINESS CONTINUES ALONG THE SRN APPALACHIANS...WITH WEAK UPPER DIVERGENCE SETTING UP OVER THE MTNS THROUGH TUE. LOW LEVEL SW FLOW SHOULD PROVIDE SOME UPSLOPE ENHANCEMENT IN THE SW MTNS WHERE CHC POPS WILL BE KEPT GOING THE LONGEST TONIGHT. SIGNALS ARE MIXED ON LOW STRATUS DEVELOPMENT TUE MORNING GIVEN A MORE SW TO W DIRECTION IN THE BL FLOW VERSUS THE SRLY WINDS OBSERVED THIS MORNING. EXPECT MIN TEMPS TO BE QUITE WARM. THE UPPER FORCING...PWAT IN PROFILES AROUND 1.75 INCHES...AND A DEVELOPING LEE TROUGH SHOULD GET LIKELY COVERAGE GOING AGAIN EARLY ON TUESDAY...WITH SIMILAR HAZARDS OF LOCALLY HEAVY RAINFALL AND AN ISOLD SEVERE THREAT. THICKNESSES SUPPORT VERY WARM TEMPS NEAR 90 TUE AFTN IN THE PIEDMONT...BUT CLOUD COVER AND PRECIP SHOULD CURB THAT SOMEWHAT. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... AS OF 230 PM MONDAY...THE SHORT TERM PERIOD LOOKS RATHER ACTIVE...HIGHLIGHTED BY A SERIES OF UPPER LEVEL IMPULSES AIDING IN DIURNAL CONVECTION...AND AN UPPER TROF DIVING THROUGH THE OHIO VALLEY THROUGH THE END OF THE PERIOD. TUESDAY EVENING A PERSISTENT BERMUDA HIGH WILL CONTINUE TO PROMOTE SOUTHERLY FLOW. MID TO UPPER 60S DEWPOINTS AND SURFACE TEMPERATURES IN THE 80S WILL CONTINUE TO ALLOW FOR ENOUGH INSTABILITY FOR CONVECTION INTO THE EVENING HOURS. THUS...KEPT SOLID CHANCE POPS THROUGH SUNSET. MEANWHILE...UPPER LEVEL PATTERN BEGINS TO AMPLIFY SOMEWHAT AS TROF DEEPENS ACROSS THE UPPER MIDWEST. AS THE DISTURBANCE MOVES EASTWARD THROUGH THE GREAT LAKES REGION ON WEDNESDAY...HEIGHTS ACROSS NORTHEAST GEORGIA AND THE CAROLINAS WILL BEGIN TO FALL. AS FLOW AT THE SURFACE REMAINS SOUTHERLY...AND HEIGHTS FALL ALOFT...EXPECTING SOME RATHER WIDESPREAD CONVECTION TO OCCUR WEDNESDAY AFTERNOON. BOTH GFS AND NAM FORECAST SOUNDINGS INDICATE SUBSTANTIAL DRYING IN THE MID LEVELS INTO THE AFTERNOON HOURS THUS STEEPENING LAPSE RATES. LIKEWISE...SBCAPE VALUES NEARING 1500-2000J/KG CANNOT BE RULED OUT...ESPECIALLY ACROSS THE HIGHER TERRAIN AND THE UPSTATE OF SC. KEPT HIGH END CHANCE POPS ACROSS THE ENTIRE REGION WITH SLIGHTLY HIGHER POPS OVER THE ABOVE MENTIONED AREAS. WITH ALL THAT SAID...SHEAR PROFILES LOOK RATHER BLEAK AS FLOW THROUGH THE COLUMN IS WEAK. THUS NOT EXPECTING ANY ROTATING STORMS...LEADING TO A MORE DAMAGING WIND...LARGE HAIL...AND HEAVY RAINFALL THREAT. MOST IF NOT ALL CONVECTION SHOULD CEASE BY NEAR OR SLIGHTLY AFTER SUNSET ON WEDNESDAY EVENING AS DIURNAL HEATING IS LOST. TEMPERATURES WILL BE SLIGHTLY ABOVE NORMAL FOR MOST AREAS ON WEDNESDAY. AS THE UPPER TROF DIGS OUT ACROSS THE OHIO AND TENNESSEE RIVER VALLEYS ON THURSDAY...UPPER LEVEL HEIGHTS WILL FALL FURTHER...AND A SURFACE COLD FRONT WILL BE MOVING CLOSER TO THE REGION. EXPECTING MUCH OF THE SAME ON THURSDAY AS SURFACE HEATING AND MODEST DEWPOINTS WILL ALLOW FOR SUBSTANTIAL CAPE. HOWEVER ALTHOUGH NOT THAT HIGH...THURSDAY WILL YIELD MORE SHEAR THAN WEDNESDAY AS THE TROF BASE SWINGS THROUGH...AND THE COLD FRONT APPROACHES. THIS WILL LEAD TO AT LEAST SOME POTENTIAL FOR BETTER CONVECTIVE ORGANIZATION. LOOK FOR THE MAIN THREATS ON THURSDAY TO BE DAMAGING WINDS...LARGE HAIL...AND HEAVY RAINFALL. CONVECTION WILL LIKELY BE MOST INTENSE ALONG AND AHEAD OF THE FRONT DURING THE AFTERNOON HOURS. WENT WITH LIKELY POPS EARLY IN THE DAY ACROSS THE HIGHER TERRAIN AND SOLID CHANCE POPS ELSEWHERE. TEMPERATURES ON THURSDAY WILL BE AT OR SLIGHTLY BELOW NORMAL AS THUNDERSTORM DEVELOPMENT WILL PLAY A MAJOR ROLE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 200 PM MONDAY...THE EXTENDED PERIOD BEGINS WITH THE CWA ON THE FAR WESTERN PERIPHERY OF A BERMUDA HIGH AND AN UPPER LEVEL TROUGH QUICKLY DEVELOPING OVER THE REGION ON THURSDAY. THE TROUGH DEEPENS OVER THE WEEKEND AND TAKES OVER THE MAJORITY OF THE EASTERN CONUS...WHILE A COLD FRONT APPROACHES WITH THE TROUGH AND THEN STALLS OUT OVER THE AREA FOR THE WEEKEND. THE TROUGH REMAINS THE DOMINANT FEATURE FOR MOST OF THE EXTENDED PERIOD...WITH HIGH PRESSURE ONLY BEGINNING TO BUILD BACK IN TO THE WEST OF THE FORECAST AREA BY EARLY NEXT WEEK. CONVECTION WILL BE MAINLY DIURNAL IN NATURE...WITH ISOLATED TO SCATTERED COVERAGE OVER THE FOOTHILLS AND MOUNTAINS EACH AFTERNOON. THE HIGHEST POPS WILL BE FEATURED EARLY IN THE WEEKEND WITH THE FRONTAL PASSAGE. CLOUD COVER AND THE PERSISTENT UPPER TROUGH WILL KEEP HIGH TEMPERATURES SLIGHTLY COOLER THAN AVERAGE OVER THE WEEKEND...BUT NORTHWESTERLY FLOW FOLLOWING THE FRONT WILL DRY OUT THE AIRMASS AND ALLOW A SLIGHT WARMING TREND BY LATE WEEKEND/EARLY NEXT WEEK. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... AT KCLT...THE TRAINING CLUSTER OF THUNDERSTORMS HAS SET UP MAINLY S TO SE OF THE AIRFIELD THIS AFTN...BUT CLOSE ENOUGH TO CARRY WALL TO WALL THUNDER THROUGH 00Z...WITH TEMPO GUSTS AND MVFR RESTRICTIONS IN ANY HEAVIER RAINFALL. WE COULD SEE ADDITIONAL DEVELOPMENT FROM THE FOOTHILLS LATER THIS AFTN/EVENING PER THE LATEST HRRR RUN. CONFIDENCE IS LOWER ON THAT...SO WILL RAMP DOWN TO A VCSH FOR NOW. CIGS AND VSBY ARE A REAL QUESTION MARK OVERNIGHT...WITH SOME STRATUS LIKELY IN THE LOWER PIEDMONT...BUT WITH SW TO W BL FLOW PROVIDING MUCH LESS OF A PUSH INTO THE TERMINAL AREA. WILL HINT THAT WAY WITH SCT010 BUT KEEP CIGS AND VSBY VFR FOR NOW. EXPECT AN EARLY START TO CONVECTION AGAIN ON TUE WITH VERY MOIST PROFILES AND SLIGHTLY IMPROVING UPPER SUPPORT. ELSEWHERE...THUNDERSTORMS ARE LIKELY AT TIMES AT ALL THE MTN AND FOOTHILLS TAF LOCATIONS THIS AFTN AND EVENING. WILL RIDE ON SOME FAIRLY BROAD VCTS GROUPS FOR NOW...BUT TEMPO WILL LIKELY BE NEEDED AT TIMES LATER ON. EXPECT MAINLY VFR CIGS EXCEPT BRIEF MVFR IN ANY TSTMS ALONG WITH BRIEFLY GUSTY WINDS. SCT SHRA OR TSRA COULD CONTINUE INTO THE OVERNIGHT HOURS...BUT WITH THE BEST FOCUS IN SW MTN UPSLOPE AREAS...SO WILL ALLOW COVERAGE TO WANE FOR NOW. MTN VALLEY FOG/CIG PROBLEMS LOOK LIKELY...WITH IFR AT KAVL BY 08Z. EAST OF THE MTNS...CONFIDENCE IS LOWER GIVEN THE SW TO W BL FLOW. SOME STRATUS SEEMS LIKELY TOWARD DAYBREAK...AND POSSIBLY VSBY ISSUES IF THE TERMINALS SEE HEAVY RAINFALL LATE TODAY. EXPECT ANOTHER EARLY START TO CONVECTION ON TUE WITH THE AIRMASS REMAINING VERY MOIST. OUTLOOK...EXPECT UNSETTLED WEATHER AT THE TERMINAL LOCATIONS THROUGH THE WEEK...WITH UPPER TROUGHINESS PERSISTING AND THEN DEEPENING MID TO LATE WEEK. THIS SHOULD LEAD TO MORNING FOG/STRATUS RESTRICTIONS...WITH MAINLY AFTN/EVENING TSRA EACH DAY. CONFIDENCE TABLE... 18-24Z 00-06Z 06-12Z 12-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 90% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 94% MED 66% MED 71% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 95% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 95% HIGH 95% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...VISIN NEAR TERM...HG SHORT TERM...CDG LONG TERM...VISIN AVIATION...HG
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
314 PM MDT MON JUN 24 2013 .SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT ISSUED AT 313 PM MDT MON JUN 24 2013 CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER SOUTHEASTERN MT...WITH WARM FRONT STRETCHING EAST-SOUTHEASTWARD ACROSS NORTHERN SD. A DRYLINE HAS DEVELOPED SOUTH OF THE LOW ACROSS EASTERN WY. UPPER LEVEL ANALYSIS SHOWS LOW OVER SOUTHWESTERN ONTARIO...WITH ANOTHER LOW OFF THE PACIFIC NW COAST. SOUTHWEST FLOW ALOFT IS IN PLACE ACROSS THE REGION...WITH IMBEDDED SHORTWAVE ENERGY CROSSING THE REGION. THE NEXT SHORTWAVE UPSTREAM IS MOVING EAST-NORTHEAST ACROSS CENTRAL AND EASTERN PORTIONS OF WY. REGIONAL RADARS SHOWING SOME SHOWERS AND STORMS DEVELOPING ACROSS EASTERN WY INTO FAR WESTERN NEB AND SOUTHWESTERN SD. SKIES ARE PARTLY CLOUDY/MOSTLY SUNNY ACROSS THE AREA WITH TEMPS GENERALLY IN THE 80S. SOUTH TO SOUTHEAST WINDS CONTINUE TO BRING LOW LEVEL MOISTURE INTO THE AREA...WITH DEWPOINTS IN THE UPPER 50S TO MID 60S ACROSS MUCH OF THE PLAINS RIGHT NOW. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED LATE TODAY INTO THIS EVENING AS SHORTWAVE ENERGY CROSSES THE AREA. THE BEST CHANCES FOR PCPN STILL LOOK TO BE ACROSS SOUTHWESTERN INTO CENTRAL SD. WITH INSTABILITY INCREASING THROUGH LATE TODAY THERE WILL BE ISOLATED STRONG TO SEVERE STORMS ACROSS THE AREA WITH LARGE HAIL AND STRONG WIND GUSTS. SHEAR WILL BE ADEQUATE FOR POSSIBLE SUPERCELLS AS WELL. THE ACTIVITY COULD ORGANIZE INTO AN MCS THIS EVENING OVER EASTERN PORTIONS OF THE AREA. SHOWERS AND STORMS WITH THIS WAVE SHOULD GENERALLY END OVER THE CWA BY 06Z. HOWEVER...ISOLATED SHOWERS/STORMS COULD DEVELOP ACROSS NORTHERN PORTIONS OF THE CWA LATE TONIGHT AS SOUTHERLY LOW LEVEL JET INTENSIFIES OVER THE AREA AHEAD OF APPROACHING COLD FRONT. COLD FRONT WILL MOVE THROUGH THE AREA FROM WEST TO EAST LATE TONIGHT AND TUESDAY MORNING. THE FRONT COULD STALL OUT OVER SOUTH CENTRAL SD TUESDAY AFTERNOON. ANY CHANCES FOR SHOWERS AND THUNDERSTORMS SHOULD BE LIMITED TO NORTHERN AND EASTERN PORTIONS OF THE CWA...MAINLY DURING THE LATE MORNING AND EARLY AFTERNOON HOURS. DRIER AIR WILL BUILD IN BEHIND THE FRONT. HOWEVER...NOT MUCH IN THE WAY OF COOLER AIR IS EXPECTED. HIGHS WILL STILL BE IN THE UPPER 70S AND 80S...WITH A FEW LOCATIONS AROUND SOUTH CENTRAL SD REACHING 90 DEGREES. BREEZY TO WINDY NORTHWESTERLY WINDS WILL DEVELOP BEHIND THE FRONT... ESPECIALLY ACROSS THE NORTHWESTERN AND WEST CENTRAL SD PLAINS. SKIES WILL BECOME MAINLY CLEAR LATE IN THE DAY WITH DECREASING WIND DURING THE EVENING. && .LONG TERM...WEDNESDAY THROUGH MONDAY ISSUED AT 313 PM MDT MON JUN 24 2013 WESTERN ATLANTIC BLOCKING WITH A CONTINUED DEEP NEGATIVE HEIGHT ANOMALY OVER THE NORTHERN PAC WILL FAVOR A NEAR OMEGA BLOCK OVER NOAM...WITH A STAUNCH WESTERN NOAM RIDGE EXPECTED. THIS WILL KEEP THE REGION IN MAINLY DRY NW FLOW. HOWEVER...A RIDGE TOPPING DISTURBANCE CANNOT BE RULED OUT TOWARD THIS WEEKEND AS INDICATED IN THE ECMWF. THE QUESTION REMAINS WHETHER THE RIDGE WILL REMAIN OVER WESTERN NOAM OR BEING TO SHIFT EAST AS SIGNALED IN THE MEAN GEFS. EITHER WAY...A DRY FORECAST IS FAVORED ATTM. IN ADDITION...THE REGION WILL REMAIN ON THE EDGE OF THE ASSOCIATED THERMAL RIDGE...WITH TEMPS IN THE 90S POSSIBLE AT TIMES...EVEN WARMER BY EARLY NEXT WEEK IF THE RIDGE DOES SHIFT EAST. OVERALL...VERY LITTLE CHANGE MADE TO THE PREVIOUS FORECAST. WILL SIDE SLIGHTLY BELOW GUIDANCE MOST OF THE PERIOD GIVEN THE CONTINUED WARM MODEL BIAS OF LATE...LIKELY FUELED BY ONGOING GREEN AND MOIST CONDITIONS. RETAINED LOW POPS THIS WEEKEND...WITH DRY CONDITIONS OTHERWISE && .AVIATION...FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING ISSUED AT 313 PM MDT MON JUN 24 2013 A STRONG UPPER LEVEL DISTURBANCE AND ASSOCIATED SFC TROUGH WILL ADVECT THROUGH THE REGION TODAY...SUPPORTING TS DEVELOPMENT THIS AFTERNOON/EVENING...POSSIBLY SEVERE. STRONG CAPPING MAY LIMIT STORMS TO DISCRETE SUPERCELLS. HOWEVER...SOME HIRES MODEL SOLUTIONS FAVOR THE DEVELOPMENT OF A SQUALL LINE ACROSS WESTERN SD...PROPAGATING EAST THROUGH THE SD PLAINS THIS EVENING. WILL RETAIN PREVIOUS VCTS MENTION AT GCC AND WILL ADD TEMPO ON A NEED BE BASIS. DID ADD A TEMPO AT RAP WHERE BETTER CHANCES FOR TS WILL BE FOUND. MVFR TO IFR CIGS/VIS WOULD BE POSSIBLE WITH ANY THUNDERSTORM. COLD FRONT WILL PROPAGATE THROUGH THE AREA TUES MORNING...WITH WINDS SHIFTING NW AND BECOMING BREEZY AT TIMES...ESP OVER THE SD PLAINS. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...26 LONG TERM...JC AVIATION...JC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1132 AM MDT MON JUN 24 2013 .UPDATE... ISSUED AT 941 AM MDT MON JUN 24 2013 CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER FAR SOUTHEASTERN MT...WITH WARM FRONT STRETCHING SOUTHEASTWARD ACROSS WESTERN SD. UPPER LEVEL ANALYSIS SHOWS LOW OVER SOUTHWESTERN ONTARIO...WITH ANOTHER LOW OFF THE PACIFIC NW COAST. SOUTHWEST FLOW ALOFT IS IN PLACE ACROSS THE REGION...WITH IMBEDDED SHORTWAVE ENERGY OVER THE REGION. ONE SHORTWAVE IS MOVING ACROSS EASTERN PORTIONS OF NEB AND SD...WITH SHOWERS EXITING SOUTH CENTRAL SD. ANOTHER SHORTWAVE IS NOTED OVER EASTERN UT AND NORTHWESTERN CO...MOVING NORTHEASTWARD INTO SOUTHERN WY. SKIES ARE MOSTLY SUNNY ACROSS MUCH OF THE AREA...WITH TEMPS IN THE UPPER 60S AND 70S. SOUTH TO SOUTHEAST WINDS CONTINUE TO BRING INCREASING MOISTURE INTO THE AREA...WITH DEWPOINTS IN THE UPPER 50S AND LOWER 60S ACROSS MUCH OF THE PLAINS RIGHT NOW. HAVE MADE MOSTLY MINOR UPDATES TO THE FORECAST FOR THE REST OF TODAY AND INTO TONIGHT. REMOVED POPS FOR LATE THIS MORNING AND ADJUSTED AFTERNOON POPS SLIGHTLY TO GIVE BETTER CHANCES FOR LATE AFTERNOON. SHORTWAVE TO THE SOUTHWEST WILL PUSH INTO SOUTHWESTERN PORTIONS OF THE CWA DURING THE MID AFTERNOON AND TRACK NORTHEAST ACROSS THE AREA DURING THE LATE AFTERNOON AND EVENING. LOW PRESSURE WILL REMAIN OVER NORTHWESTERN PORTIONS OF THE AREA INTO THE AFTERNOON AND THEN SLOWLY MOVE EAST AS THE SHORTWAVE SLIDES THROUGH. A DRY LINE WILL ALSO DEVELOP TO THE SOUTH OF THE LOW ACROSS FAR EASTERN WY DURING THE AFTERNOON...HELPING TO AID IN THUNDERSTORM DEVELOPMENT AS THE SHORTWAVE ARRIVES. THE BEST CHANCES FOR PCPN LOOK TO BE ACROSS SOUTHWESTERN INTO CENTRAL SD LATE THIS AFTERNOON AND EVENING. WITH INSTABILITY PROGGED TO BE VERY HIGH LATE TODAY AND THIS EVENING...ESPECIALLY SOUTH AND EAST OF THE BLACK HILLS...THERE WILL LIKELY BE A FEW STRONG TO SEVERE STORMS ACROSS THE AREA...WITH LARGE HAIL AND STRONG WIND GUSTS. SHEAR WILL BE ADEQUATE FOR ISOLATED SUPERCELLS AS WELL. THE OTHER MAIN ADJUSTMENT TO THE FORECAST WAS TO RAISE HIGH TEMPS A COUPLE OF DEGREES ACROSS AREAS SOUTH AND EAST OF THE BLACK HILLS AS WARM FRONT LIFTS SLOWLY NORTH AND EAST DURING THE DAY. && .SHORT TERM...TODAY THROUGH TUESDAY NIGHT ISSUED AT 358 AM MDT MON JUN 24 2013 UPPER LEVEL ANALYSIS HAS WEAK RIDGING ACROSS THE NORTHERN AND CENTRAL PLAINS WITH LARGE TROF OVER THE PACIFIC NORTHWEST. ONGOING MCS IS PUSHING THROUGH CENTRAL NEBRASKA...AND LOOKS TO CLIP FAR SOUTH CENTRAL SOUTH DAKOTA EARLY THIS MORNING. AT THE SURFACE...HIGH PRESSURE IS LOCATED OVER THE CENTRAL CONUS...WITH LOW PRESSURE DEVELOPING OVER THE NORTHERN ROCKIES. TEMPERATURES ARE MILD THIS MORNING...MAINLY IN THE 60S. WINDS ARE GENERALLY OUT OF THE SOUTH TO SOUTHEAST AT 5 TO 15 MPH. FOR TODAY...OVERNIGHT CONVECTION WILL GRAZE FAR SOUTH CENTRAL SOUTH DAKOTA DURING THE EARLY MORNING HOURS. BY THE AFTERNOON INSTABILITY INCREASES GREATLY ACROSS WESTERN SOUTH DAKOTA WITH SOME MODELS INDICATING CAPE VALUES EASILY OVER 3000 J/KG. SHEAR WILL BE ADEQUATE TO SUPPORT SUPERCELLS...PARTICULARLY OVER THE ERN CWA. STRONG STORMS COULD DEVELOP BY EARLY/MID AFTERNOON AS INITIAL WAVE LIFTS THROUGH SWRLY FLOW. MAIN THREAT WITH THESE STORMS WILL BE LARGE HAIL AND DAMAGING WINDS. CHANCES WILL CONTINUE INTO THE EARLY EVENING WITH STORMS PUSHING TO THE EAST OF THE AREA BY LATE EVENING. ON TUESDAY...UPPER SHORTWAVE TROF WILL SWING THROUGH WESTERN NORTH DAKOTA BY EARLY AFTERNOON...AS SURFACE TROF SLIDES THROUGH EASTERN SOUTH DAKOTA. BEST CHANCE FOR PRECIP WILL BE CONFINED TO NORTH AND WESTERN PORTIONS OF THE FORECAST AREA. REMAINDER OF THE AREA SHOULD SEE PARTLY CLOUDY SKIES AND BREEZY WEST TO NORTHWEST WINDS AS SURFACE TROF MOVES EAST OF THE AREA. HIGH TEMPS WILL BE IN THE 70S AND 80S. && .LONG TERM...WEDNESDAY THROUGH SUNDAY ISSUED AT 358 AM MDT MON JUN 24 2013 UPPER RIDGE BUILDING OVER THE WESTERN CONUS WILL BRING DRY AND WARM WEATHER THROUGH THE END OF THE WORK WEEK. MODELS DIVERGE NEXT WEEKEND AS TO THE STRENGTH OF THE RIDGE. ECMWF KEEPS THE RIDGE AMPLIFIED OVER THE NRN ROCKIES/NRN PLAINS WHILE THE GFS SHOWS A SLIGHT BREAKDOWN IN THE RIDGE WITH WESTERLIES DEVELOPING. WILL FAVOR SLIGHT CHANCES FOR POPS OVER THE WEEKEND...WHILE KEEPING TEMPS ABOVE AVERAGE. && .AVIATION...FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON ISSUED AT 1129 AM MDT MON JUN 24 2013 A STRONG UPPER LEVEL DISTURBANCE AND ASSOCIATED SFC TROUGH WILL ADVECT THROUGH THE REGION TODAY...SUPPORTING TS DEVELOPMENT THIS AFTERNOON/EVENING...POSSIBLY SEVERE. STRONG CAPPING MAY LIMIT STORMS TO DISCRETE SUPERCELLS. HOWEVER...SOME HIRES MODEL SOLUTIONS FAVOR THE DEVELOPMENT OF A SQUALL LINE ACROSS WESTERN SD...PROPAGATING EAST THROUGH THE SD PLAINS THIS EVENING. WILL RETAIN PREVIOUS VCTS MENTION AT GCC AND WILL ADD TEMPO ON A NEED BE BASIS. DID ADD A TEMPO AT RAP WHERE BETTER CHANCES FOR TS WILL BE FOUND. MVFR TO IFR CIGS/VIS WOULD BE POSSIBLE WITH ANY THUNDERSTORM. COLD FRONT WILL PROPAGATE THROUGH THE AREA TUES MORNING...WITH WINDS SHIFTING NW AND BECOMING BREEZY AT TIMES...ESP OVER THE SD PLAINS. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ UPDATE...26 SHORT TERM...15 LONG TERM...JOHNSON AVIATION...JC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
327 PM EDT MON JUN 24 2013 .SYNOPSIS... A TYPICAL SUMMER PATTERN CONTINUES WITH HIGH PRESSURE SITUATED ACROSS THE SOUTHEAST AND SOUTHWEST FLOW KEEPING US WARM AND HUMID WITH A DAILY THREAT OF SHOWERS AND STORMS THROUGH AT LEAST MIDWEEK. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST LATE IN THE WEEK WITH MORE WIDESPREAD SHOWERS AND THUNDERSTORMS LIKELY BY THURSDAY OR FRIDAY. THE FRONT LOOKS TO SLOW DOWN CROSSING THE REGION OVER THE WEEKEND KEEPING SHOWERS AND STORMS AROUND INTO AT LEAST SUNDAY. && .NEAR TERM /THROUGH TUESDAY/... AS OF 230 PM EDT MONDAY... WIDELY SCATTERED CONVECTION LOOKS TO CONTINUE ACROSS THE AREA INTO THIS EVENING WITH PERHAPS A GRADUAL MIGRATION OF STORM DEVELOPMENT OFF INTO THE NE/EASTERN COUNTIES WHERE BETTER HEATING/INSTAB EXISTS AND A WEAK VORT TAIL WILL BE PASSING ACROSS. THIS SIMILAR TO THE LATEST HRRR AND RAP SOLUTIONS WHICH END UP WITH MOST COVERAGE OVER THE EAST OR SE AS THE WEAK CAP ALOFT LOOKS TO GIVE WAY BEFORE LOSS OF HEATING. THINK WESTERN AREAS MAY ACTUALLY SEE LESS GIVEN CLOUDS AND LOWER CAPE DUE TO EARLIER SHRA SO TRIMMING POPS BACK A BIT FAR WEST EARLY ON WHILE GOING WITH CONTINUED SCATTERED COVERAGE EAST. AGAIN WITH LACK OF MUCH UPPER SUPPORT...EXPECT COVERAGE TO BECOME MORE ISOLATED THIS EVENING WITH SOME FOG DEVELOPING VALLEYS AND WHERE DOWNPOURS OCCURRED EARLIER. SOME ADDED SHRA THEN POSSIBLE AGAIN LATER TONIGHT AS THE WEAK UPSTREAM VORT OVER KY SLIDES EAST AND DAMPENS OUT ACROSS THE MOUNTAINS BY MORNING. SINCE GUIDANCE NOT LATCHING ONTO MUCH LIFT WITH THIS FEATURE...WILL ONLY KEEP A TOKEN POP IN FAR WEST FOR NOW AND LEAVE ELSW DRY LATER ON. LOWS A BIT MORE WARM/MUGGY OVERNIGHT WITH TEMPS ONLY DROPPING INTO THE MID 60S TO AROUND 70 WITH LOW 60S ONLY IN THE DEEPEST VALLEYS. 5H WEAKNESS SLOWS ACROSS THE REGION ON TUESDAY WITH LOW LEVEL WESTERLY FLOW TURNING MORE SW DURING THE AFTERNOON AS THE EASTERN LEE TROF SLIDES FARTHER EAST. FCST SOUNDINGS ARE EVEN MORE MOIST THAN TODAY WITH LITTLE CAP ALTHOUGH QUESTIONS WITH THE DEGREE OF ORGANIZATION UNDER SUCH WEAK FLOW ALOFT. THINK ENOUGH THETA-E SUPPORT TO AT LEAST HAVE ANOTHER ROUND OF SCATTERED POPS BUT WITH MORE MULTICELL CLUSTERS POSSIBLE ESPLY MOUNTAINS WHERE WILL BE A BIT COOLER ALOFT. LOOKS LIKE WEAK DOWNSLOPE MAY CAUSE A DELAY IN TSRA EAST WITH MORE OF A LATE AFTERNOON SCENARIO AIDED BY WESTERN COVERAGE MOVING EAST AFTER SOME LOW LEVEL BACKING HAS DEVELOPED. FOR NOW WILL CONTINUE TREND OF HIGH CHANCE POPS BUT MAY NEED TO GO HIGHER LATER PENDING UPDATED MODEL SOLUTIONS. WITH 85H TEMPS A COUPLE DEGREES WARMER AND LIGHT WEST WINDS...WOULD EXPECT HIGHS TO TOP 90 SE...AND HEAD WELL INTO THE 80S OUTSIDE OF THE HIGHER ELEVATIONS...CLOSER TO THE WARMER MAV MOS. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... AS OF 305 PM EDT MONDAY... ZONAL FLOW AND A LEE TROUGH WILL START THE WEATHER PATTERN TUESDAY NIGHT. THIS PATTERN WILL HAVE FADING DIURNAL THUNDERSTORMS IN THE EVENING WITH PATCHY FOG DEVELOPING WHERE IT RAINED DURING THE DAY TUESDAY. THE LEE TROUGH WILL HELP INITIATE SCATTERED CONVECTION AGAIN WEDNESDAY AFTERNOON. PWATS ARE AROUND NORMAL WITH MOISTURE ADVECTION COMING FROM THE SOUTHWEST. WITH MOISTURE AND HEATING...A FEW STORMS COULD BE STRONG TO SEVERE WEDNESDAY AFTERNOON AND EVENING. CORFIDI VECTORS ARE ALSO VERY WEAK TUESDAY AND WEDNESDAY. STORMS WILL BE SLOW MOVING/ANCHORED CREATING A VERY LOCALIZED FLASH FLOOD THREAT. ONCE AGAIN...SHOWERS WILL FADE AFTER SUNSET WITH A FEW HANGING ON UNTIL MIDNIGHT WITH LINGER INSTABILITIES. TEMPERATURES WILL RUN WARMER THAN NORMAL THROUGH THE PERIOD BY 5 DEGREES OR SO. OVERNIGHT LOWS GENERALLY IN THE 60S WITH DAY TIME HIGHS IN THE 80S...LOW 90S IN THE PIEDMONT. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 230 PM EDT MONDAY... AN OCCLUDED LOW WILL WORKS ITS WAY TO THE EAST THURSDAY FROM THE GREAT LAKES TO LAKE ERIE. WITH A LEE TROUGH IN THE EAST AND AN APPROACHING WEAK FRONT/UPPER LEVEL TROUGH FROM THE WEST...MORE AREAL COVERAGE OF CONVECTION IS EXPECTED THURSDAY AFTERNOON. HAIL AND STRAIGHT LINE WINDS WILL BE THE PRIMARY THREAT. PWATS INCREASE TO 2 STANDARD DEVIATION ABOVE NORMAL...MAKING FLASH FLOOD A THREAT AS WELL. THE FRONT AND LEE TROUGH BECOME ONE ON FRIDAY. CONVERGENCE IN THIS SURFACE TROUGH SHOULD GENERATE STRONG CONVECTION...MAINLY OVER THE PIEDMONT. NOT MUCH OF AN AIRMASS CHANGE AS THE FRONT JOINS THE LEE TROUGH...THEREFORE CAN NOT RULE OUT THUNDERSTORMS ACROSS THE MOUNTAINS AND FOOTHILLS FRIDAY. A STRONGER FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY. THIS FRONT WILL BRING ANOTHER ROUND OF AREA-WIDE CHANCES OF STRONG TO SEVERE THUNDERSTORMS. LOW CONFIDENCE ON FRONTAL TIMING WITH A STRONG BLOCKING RIDGE IN THE WESTERN ATLANTIC THROUGH THE PERIOD. EVEN IF THE FRONT TRACKS ACROSS THE AREA SATURDAY...RAIN CHANCES WILL STILL EXIST SUNDAY AND MONDAY. THE BLOCKING RIDGE COULD STALL THE FRONT INLAND OF THE EAST COAST...POSSIBLY INTO THE PIEDMONT. WAVES WILL TRACK ALONG THE FRONT SUNDAY AND MONDAY KEEPING THE CHANCE OF RAIN INTO EARLY NEXT WEEK. TEMPERATURES WILL REMAIN WARMER THAN NORMAL INTO THE WEEKEND. THE MORE AREAL COVERAGE OF SHOWERS DURING A GIVEN DAY WILL KEEP TEMPERATURES CLOSER TO NORMAL. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... AS OF 110 PM EDT MONDAY SCATTERED SHRA/TSRA CLUSTERS HAVE DEVELOPED ACROSS THE MOUNTAINS EARLY THIS AFTERNOON ALONG THE PERIPHERY OF THE EARLIER MID DECK. EXPECT THIS COVERAGE TO SLOWLY INCREASE WHILE PUSHING SLOWLY EAST UNTIL FADING OUT EARLY THIS EVENING. HOWEVER STILL LOW CONFIDENCE IN WHETHER OR NOT ANY TAF LOCATION WILL EXPERIENCE A SHRA DIRECTLY BUT ENOUGH OF A THREAT TO INCLUDE A VCTS MENTION AT MOST SPOTS WITH A PERIOD OF PREVAILING MVFR VSBY AT KBLF THROUGH THE AFTERNOON. ANY MORE ORGANIZED SHOWER OR STORM CLUSTER THAT DOES COME IN THE VICINITY OF THE TAF LOCATIONS MAY RESULT IN A PERIOD OF BRIEF IFR CIGS/VSBY WHICH WILL TEMPO AS NEEDED. MOST OF THE DAYTIME ACTIVITY SHOULD DISSIPATE AFTER SUNSET. HOWEVER...THERE MAY BE SOME LINGERING SHOWER ACTIVITY WEST OF THE MTNS ASSOCIATED WITH A WEAK MID LEVEL WAVE THAT IS MOVING EAST ACROSS KENTUCKY. THIS SHOWER ACTIVITY MAY REACH KBLF AFTER MIDNIGHT TONIGHT...BUT WILL KEEP OUT OF THE TAF FCST ATTM UNTIL CAN BE MORE CERTAIN OF TIMING GIVEN QUICK DISSIPATION OF SHRA OF LATE WITH LOSS OF HEATING. OTRW APPEARS FOG WILL BE A BIT MORE WIDESPREAD OVERNIGHT GIVEN HIGHER DEWPOINTS AND MORE RESIDUAL MOISTURE FROM AFTERNOON CONVECTION. EXPECT A PERIOD OF MVFR AT MOST SITES EXCLUDING KROA...AND PERHAPS KBLF WHILE KLWB/KBCB LOOK TO DROP INTO IFR LEVELS WITH SOME LOW STRATUS AROUND LATE TONIGHT. LOW CONDITIONS SHOULD IMPROVE BY MID MORNING TUE...FOLLOWED BY MORE SCTD/BKN VFR CU AND DEVELOPING SHRA/TSRA AS A WEAK IMPULSE ALOFT PUSHES ACROSS. WEST WIND MAY CAUSE LESS COVERAGE EARLY ON WITH MORE ORGANIZED TSRA POSSIBLE BEYOND THE VALID TAF PERIOD TUE AFTERNOON. .AVIATION EXTENDED... WE WILL BE TRANSITIONING FROM A FLAT UPPER RIDGE TO A BLOCKY PATTERN WITH AN EASTERN CONUS TROF/WESTERN CONUS RIDGE THROUGH THE EXTENDED PERIOD. SFC HIGH OFF THE EAST COAST WILL KEEP WARM AND MOIST AIR OVER THE REGION WITH A SERIES OF WAVES RIPPLING THROUGH THE FLOW. THIS WILL PRIMARILY LEAVE US WITH AN UNSTABLE AIRMASS IN A WEAKLY FORCED CONVECTIVE ENVIRONMENT THROUGH MIDWEEK. EXPECT A DIURNAL PATTERN OF CONVECTION WITH VFR IN THE MORNING...THEN MVFR WITH SHRA/TSRA IN THE AFTERNOON AND EVE...THEN POSSIBLE IFR WITH NOCTURNAL FOG/STRATUS. LOOKING LIKE LATTER PORTION OF THE WEEK WILL BE MORE ACTIVE. AS THE PATTERN FINALLY BECOMES MORE AMPLIFIED AND THE ERN TROF SINKS DOWN INTO THE REGION...IT SHOULD PUSH A COLD FRONT THROUGH TOWARD THE END OF THE WEEK...WITH BETTER AVIATION CONDITIONS THEREAFTER. EXPECT WINDS TO REMAIN ON THE LIGHT SIDE UNTIL THURSDAY WHEN LOW LEVEL WIND FIELD BEGINS TO INCREASE AHEAD OF APPROACHING COLD FRONT. BEST COVERAGE OF STORMS LOOKS TO BE ON THURSDAY AS WELL WITH A POSSIBLE LINE AHEAD OF THE FRONT THRUSDAY AFTERNOON/EVENING. && .EQUIPMENT... AS OF 1225 PM EDT SUNDAY... DANVILLE ASOS VISIBILITY SENSOR REMAINS INOP AND EXPECTED TO BE FIXED TUESDAY OR WEDNESDAY OF THIS WEEK. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/WP NEAR TERM...JH SHORT TERM...RCS LONG TERM...RCS AVIATION...JH/PM EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
405 PM CDT MON JUN 24 2013 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 304 PM CDT MON JUN 24 2013 AT 3 PM...A SQUALL LINE WAS MOVING EAST THROUGH EAST-CENTRAL AND SOUTHEAST IOWA. THIS LINE HAS WIPED OUT MUCH OF THE INSTABILITY THAT MANY OF 24.00Z AND 24.06Z MODELS WERE FORECASTING TO MOVE INTO NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND SOUTHWEST AND CENTRAL WISCONSIN TONIGHT. EVEN SOME OF THE 24.12Z DETERMINISTIC MODELS WERE NOT HANDLING THIS LINE WELL...SO THEY ARE TOO HIGH ON THEIR CAPES ACROSS IOWA. IN ADDITION...THIS LINE ALSO DISRUPTED THE 925 MB AND 850 MB MOISTURE TRANSPORT INTO THE REGION. AS A RESULT...THE HEAVY RAIN THREAT FOR THIS EVENING LOOKS MUCH LESS THAN WHAT IT WAS LOOKING LIKE EARLIER THIS MORNING. FOR OVERNIGHT...THERE IS A LOT OF UNCERTAINTY ON HOW THIS PERIOD IS GOING TO MATERIALIZE. THE 24.12Z NAM WHICH HAD A SLIGHTLY BETTER HANDLE ON THE SQUALL LINE PUSHED AN OUTFLOW BOUNDARY SOUTH TO THE MISSOURI AND IOWA BORDER...THUS ITS BEST MOISTURE TRANSPORT IS FOCUSED MUCH FURTHER SOUTH. THE 925 MB MOISTURE TRANSPORT HAS SHIFTED TOWARD SOUTHERN IOWA. IF THIS VERIFIES... MUCH OF THE PRECIPITATION WOULD REMAIN SOUTH OF THE AREA FOR THIS TIME PERIOD. EVEN THE LATEST RAP IS LEANING TOWARD THIS SCENARIO TOO. MEANWHILE BOTH THE ECMWF AND GEM MODELS SUGGEST THAT AS THE SHORT WAVE IN THE SOUTHERN PLAINS MOVES NORTHEAST INTO THE SOUTHERN PLAINS...THE 850 MB MOISTURE TRANSPORT SHIFTS BACK NORTHWARD TOWARD THE AREA TOWARD SUNRISE. IF THIS SCENARIO VERIFIES...THERE COULD BE A POTENTIAL FOR THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS LATE TONIGHT. WITH ITS PRECIPTABLE WATER VALUE CLOSE TO 2.00 INCHES AND WARM CLOUD LAYER DEPTHS UP TO 4.5 KM...THERE WOULD BE THE POTENTIAL FOR HEAVY RAIN. WITH SO MANY DIVERSE MODEL SOLUTIONS...OPTED TO LOWER THE PRECIPITATION CHANCES SOME AND ALSO SHIFTED THE HIGHER CHANCES TO LATER IN THE NIGHT. HOPEFULLY...THE 24.00Z MODELS WILL BE BETTER AT RESOLVING THE STABLE LAYER THAT WAS LEFT IN THE WAKE OF THE SQUALL LINE. ON TUESDAY...EXPECT THE 925 MB AND 850 MB MOISTURE TRANSPORT TO INCREASE ACROSS IOWA. HOWEVER THERE IS SOME UNCERTAINTY HOW FAR NORTH THIS OCCUR. THE 24.18Z NAM AND 24.12Z GFS WOULD SUGGEST THAT THE HEAVIEST RAIN WOULD FALL ACROSS CENTRAL IOWA. MEANWHILE THE 24.12Z ECMWF AND GEM WOULD SUGGEST THAT THE HEAVIEST RAIN WOULD FALL SOUTH OF INTERSTATE 90. WITH THE INITIAL CONDITIONS SO MUDDLED...CONFIDENCE IS NOT THAT HIGH. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 304 PM CDT MON JUN 24 2013 ON TUESDAY NIGHT...MUCH OF THIS TIME PERIOD REMAINS UNCLEAR DUE TO UNCERTAINTIES ON WHERE THE BOUNDARIES WILL END UP FROM TONIGHT AND WHERE THUNDERSTORMS DEVELOP ON TUESDAY. THE GEM AND ECMWF HAVE THEIR MESOSCALE CONVECTIVE COMPLEXES MOVING ALONG AND SOUTH OF THE INTERSTATE 94 CORRIDOR. MEANWHILE THE GFS AND NAM SUGGEST THAT THE MESOSCALE CONVECTIVE COMPLEX WILL DEVELOP ACROSS IOWA...AND THEN MOVES IT NORTHEAST WITH THE SHORT WAVE INTO THE FORECAST AREA. WITH WARM CLOUD LAYER DEPTHS OVER 4 KM AND PRECIPITABLE WATER VALUES AROUND 2 INCHES. THERE WILL BE THE POTENTIAL FOR SOME FLASH FLOODING. ON WEDNESDAY AND WEDNESDAY EVENING...ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS THE AREA AS THE LOW PRESSURE AREA MOVES EAST ACROSS THE AREA. PRECIPITABLE WATER VALUES SLOWLY DROP TO AROUND 1.60 INCHES AND THE WARM CLOUD LAYER DEPTHS FALL INTO THE 3 TO 3.5 KM RANGE. WHILE THERE WILL BE THE POTENTIAL FOR SOME HEAVY RAIN...THE AMOUNTS LOOK TO BE MUCH LESS THAN WHAT THEY ARE FROM TONIGHT INTO TUESDAY NIGHT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 129 PM CDT MON JUN 24 2013 PERIODS OF TSRA WILL OCCUR THROUGH ABOUT 00Z. THIS MAY NEED TO BE EXTENDED IN THE TAF SITES...WILL MONITOR...AS 18Z TAFS HAVE 2 HOURS OF TEMPO TSRA. MASSIVE CONVECTIVE COMPLEX ACROSS IA HAS REALLY IMPACTED TSRA FORECAST FOR THE OVERNIGHT HOURS. WAS THINKING THAT A MASSIVE RAIN EVENT WAS IN PLACE BUT WITH THE IA CONVECTION...MANY OF THE GOOD SET UP PARAMETERS ARE NOT AS FAVORABLE ANY LONGER OVERNIGHT. LATER FORECASTS MAY REMOVE THE TSRA TO LESSER HOURS OR IMPACT. CEILINGS WILL ALSO BE VERY DIFFICULT WITH MESSY...UNORGANIZED PATTERN THROUGH THE PERIOD. CONFIDENCE IS LOW IN THE TAF BEYOND 4-5 HOURS. && .HYDROLOGY... ISSUED AT 304 PM CDT MON JUN 24 2013 WITH A WIDE VARIETY OF SOLUTIONS IN THE 24.12Z AND 24.18Z MODELS...CONFIDENCE HAS LOWERED ON THE THREAT FOR FLASH FLOODING TONIGHT. HOWEVER WITH MANY RIVERS REMAINING EITHER HIGH OR ARE FLOODING ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN. CONFIDENCE WAS NOT HIGH ENOUGH TO CANCEL THE FLASH FLOOD WATCH. LOOKING AHEAD TO TUESDAY AND TUESDAY NIGHT...SOME MODELS SUGGEST THAT HEAVY RAIN COULD FALL SOUTH OF INTERSTATE 94. MEANWHILE OTHER MODELS HINT THAT THE HEAVIEST PRECIPITATION WILL REMAIN SOUTH OF THE FORECAST AREA. WITH SUCH DIVERSE SPREADS IN THE MODELS...OPTED NOT TO EXTEND THE FLASH FLOOD WATCH INTO TUESDAY NIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ032>034-041>044- 053>055-061. MN...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR MNZ079-086>088- 094>096. IA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR IAZ008>011-018-019- 029-030. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...BAUMGARDT HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
334 PM CDT MON JUN 24 2013 .VERY SHORT TERM...TONIGHT AND TUESDAY. TONIGHT - CONFIDENCE...LOW EXPECTING A WEAKENED VERSION OF IOWA COMPLEX TO TRAVERSE ACROSS THE CWA LATER THIS AFTERNOON AND EARLY EVENING. STRONGEST PORTION OF IOWA COMPLEX WILL LIKELY RIDE THE MLCAPE GRADIENT IN NORTHERN IL PER SPC MESO ANALYSIS...BUT SOME INCREASE INSTABILITY SNEAKING BACK NORTH TOWARDS THE SRN COUNTIES. IN FACT 3 HOURLY MLCAPE CHANGE WHILE GREATEST IN NRN IL...DOES SHOW AN AXIS INTO THE FAR SOUTH. THIS CLOSE ENOUGH CALL IN THE SOUTHERN TIER OF COUNTIES FOR THE SVR WATCH FROM SPC. LIKE LAST NIGHT THE MAIN CHALLENGE IS THE DEGREE AND LOCATION OF REDEVELOPMENT BECOMES THE KEY QUESTION. GETTING MODEL SOLUTIONS ALL OVER THE MAP FROM HEAVY RAINS...TO SCATTERED DEVELOPMENT TO NEXT TO NOTHING. MODELS CONSENSUS OF 850 MILLIBAR JET CORE LOOKS VERY SIMILAR TO WHERE WE NOTICED IT SUNDAY PROGGD FOR 12Z THIS MORNING. AND GIVEN WHERE ONGOING CONVECTION IS LAYING ITSELF OUT HAVE SOME CONCERN THAT IT MAY BE ANOTHER GLANCING SHOT ONCE AGAIN. HRRR DOES SHOW SOME ELEVATED DEVELOPMENT LATER TONIGHT. SO CERTAINLY WORTHY OF KEEPING THE WATCH GOING FOR NOW. TUESDAY - CONFIDENCE...MEDIUM AXIS OF LOW LEVEL JET TRANSLATES EAST A BIT AND IS AIMED MORE TOWARDS SOUTHERN WI. 500 MILLIBAR SHOWS PERIODIC VORTICITY MAXIMA WAVERING THROUGH THE WEAK WESTERLY FLOW. SOME UPPER DIVERGENCE NOTED AS WELL...THOUGH OVERALL JET ACTION LOOKS PRETTY WEAK. CWASP NUMBERS IN THE 60S...A FEW LOW 70S OFF THE NAM. BUT NOTHING EXTREME. WILL KEEP HIGH END CHANCE/LIKELY POPS GOING WITH THE OVERALL PATTERN STILL FAVORING CONVECTION DUE INSTABILITY AND RIPPLES IN THE FLOW. .SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY. TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE LOW TO MEDIUM. EVOLUTION FROM MOIST AND UNSTABLE NEAR-ZONAL WSW FLOW TO COOLER AND DRIER NW FLOW BEGINS WITH APPROACH OF SHORT WAVE TROUGH AND ASSOCIATED SURFACE LOW FROM THE DAKOTAS TUESDAY NIGHT...AND THEN PASSAGE OF THE TROUGH AND LOW THROUGH THE WESTERN GREAT LAKES WEDNESDAY AND WEDNESDAY NIGHT. BETTER FORCING FROM THERMAL ADVECTION PER NAM/GFS 850-700MB Q-VECTOR CONVERGENCE MAXIMA FOLLOWS A FAMILIAR PATTERN OF LATE ACROSS NRN/CENTRAL IA INTO NRN IL...JUST BRUSHING SRN WI...WHICH FOLLOWS ALONG THE NOSE OF THE THERMAL RIDGE AND STRONGEST 850 MB WINDS AS THEY VEER FROM SOUTH TO SOUTHEAST WITH WAVE PASSAGE. HOWEVER CONFIDENT FOR LIKELY POPS EVERYWHERE IN CWA WITH LARGE SALE FORCING FOR ASCENT PROVIDED BY DIFFERENTIAL CVA THAT WORKS ON UNSTABLE AIR MASS...WITH LOW LEVEL FORCING PROVIDED BY LOW TO MID-LAYER FRONTOGENETIC FORCING. FLOODING A CONCERN WITH ANY CONVECTION IN THIS MOISTURE RICH ENVIRONMENT WITH 1.7 TO 1.9 INCH PW/S OR ABOUT 160 PCT OF NORMAL. BEST PERFORMING MODEL QPF FORECASTS BRING AREAL AVERAGE PRECIPITATION OF 1 TO 1.5 INCHES TO THE CWA...BUT ACTUAL AMOUNTS WILL BE MUCH HIGHER WITH ANY MCS THAT MOVES ACROSS CWA. KEPT LIKELY POPS IN THE NORTH WITH BETTER OMEGA AS SFC LOW MOVES THROUGH WEDNESDAY...AND CHANCE POPS EVERYWHERE ELSE...TAPERING OFF WEDNESDAY NIGHT FROM WEST TO EAST BEHIND THE LOW. WITH EXPECTED CONVECTION AND AT LEAST A SIGNIFICANT AMOUNT OF CLOUD DEBRIS WENT WITH BLENDED HIGHS THAT TEND TOWARD THE COOLER SIDE OF GUIDANCE. THURSDAY...FORECAST CONFIDENCE MEDIUM. MODELS DIFFER WITH HOW FAR EAST TO TAKE INITIAL SHORT WAVE TROUGH BY THURSDAY MORNING...BUT ALL SHOW VORTICITY MAXIMA DROPPING THROUGH EASTERN WI AT SOME POINT DURING THE DAY THURSDAY. NAM SOUNDINGS LOOK A BIT TOO GENEROUS WITH SURFACE DEW POINTS...BUT LOW TO MID 80 TEMPS WITH MID-UPPER 60 DEW POINTS STILL YIELD TALL SKINNY SURFACE-BASED CAPE OF AT LEAST 600-800 J/KG...SO WILL HAVE CHANCE THUNDER IN THE EAST...BUT LEAVE WESTERN AREAS DRY. .LONG TERM...THURSDAY NIGHT THROUGH MONDAY. FORECAST CONFIDENCE MEDIUM. MODELS CONTINUE TO DIG EASTERN TROUGH THROUGH THE END OF THE WORK WEEK AND DROP A A REINFORCING SHORT WAVE THROUGH THE REGION THAT AIDS IN CLOSING OFF A 500 MB LOW SOMEWHERE OVER THE CENTRAL/EASTERN GREAT LAKES SATURDAY. INSTABILITY WITH THE 500 COLD POOL OVER THE REGION AND VORT MAXES ROTATING THROUGH THE TROUGH WILL KEEP AT LEAST SLIGHT CHANCE POPS IN THROUGH THE EXTENDED...WITH AT OR SLIGHTLY BELOW NORMAL TEMPERATURES INTO NEXT WEEK. && .AVIATION/00Z TAFS/...CONVECTION ACROSS IOWA TO HAVE GREATEST IMPACT IN FAR SRN WI INTO EARLY EVENING. STRONGEST ACTIVITY LOOKING TO STAY SOUTH OF THE BORDER. THEN SETUP LOOKS SIMILAR TO LAST NIGHT WHERE REDEVELOPMENT BECOMES FOCUSED FURTHER SOUTH. MODEL SOLUTIONS ARE QUITE DIVERGENT ON HOW THE LATE NIGHT CONVECTION PLAYS OUT. BUT IF LAST NIGHT IS ANY INDICATION...SOME TSRA POSSIBLE LATER TONIGHT INTO THE EARLY MORNING HOURS...THEN MORE REDEVELOPMENT DURG TUE AFTN/EVE. OVERALL...VFR WITH POCKETS OF MVFR/ISOLATED IFR IN ANY OF THE HEAVIER STORMS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ046-047-056-057- 062-063-067>069. LM...NONE. && $$ TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR TUESDAY NIGHT THROUGH MONDAY...REM
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND TUESDAY ISSUED AT 226 PM CDT MON JUN 24 2013 THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SHORTWAVE TROUGH MOVING ENE OVER FAR EASTERN SOUTH DAKOTA AND INTO SOUTHWEST MINNESOTA. AREA OF CONVECTION AHEAD OF THIS TROUGH IS DRAWING CLOSER TO THE SW WISCONSIN BORDER. CLOUD COVER OVER CENTRAL AND EAST-CENTRAL WISCONSIN HAS LIMITED HEATING SOMEWHAT TODAY...BUT ML CAPES ARE APPROACHED A 1K J/KG...THOUGH STILL HAVE SOME CIN TO OVERCOME. NOT SURE IF THIS INHIBITION WILL GET OVERCOME...SINCE CLOUDS WILL ONLY THICKEN FROM HERE ON OUT. MOSTLY CLEAR SKIES EXIST BEHIND THIS SHORTWAVE OVER THE CENTRAL PLAINS...AND THE NEXT SHORTWAVE IS MOVING OVER THE CENTRAL ROCKIES. MAIN FORECAST CONCERNS INCLUDE PRECIP CHANCES TONIGHT...AND SEVERE WEATHER CHANCES TOMORROW. TONIGHT...THE SHORTWAVE TROUGH MOVING INTO FAR SOUTHWEST MINNESOTA WILL CONTINUE TO TRACK ENE ACROSS SOUTHERN MINNESOTA AND THE NORTHERN HALF OF WISCONSIN THIS EVENING. CURRENT TRAJECTORY OF PRECIPITATION WILL PLACE THE BEST CHANCES SOUTH OF A TOMAHAWK TO IRON MOUNTAIN LINE. WITH CLOUD COVER KEEPING TEMPERATURES IN THE UPPER 70S TO LOWER 80S OVER CENTRAL AND EAST-CENTRAL WISCONSIN...THE STORMS WILL HAVE SOME CIN TO OVERCOME DESPITE ML CAPES AROUND 1000 J/KG. THINKING SEVERE CHANCES IS RATHER REMOTE SINCE THE NORTHERN END OF THE THUNDERSTORM COMPLEX IS MOSTLY STRATIFORM. PWATS WILL BE INCREASING OVER 1.50 INCHES SO THINKING HEAVY RAINFALL WILL BE THE MAIN THREAT WITH THESE STORMS...BUT EVEN THAT DOES LOOK THAT POSSIBLE. SHOWERS AND STORMS WILL HAVE MOSTLY EXITED THE REGION BY LATE IN THE EVENING...AND THEY SHOULD LAY OUT AN OUTFLOW BOUNDARY OVER SOUTHERN WISCONSIN OR POINTS FURTHER SOUTH. RETURN FLOW WILL REDEVELOP OVER THE NORTHERN PLAINS LATE SO THINKING ANY CONVECTION LATE TONIGHT WILL FALL ALONG THIS OUTFLOW BOUNDARY. HAVE DROPPED POPS SIGNIFICANTLY AFTER MIDNIGHT AND ACROSS NORTHERN WISCONSIN. MUGGY LOWS IN THE MIDDLE 60S. TUESDAY...MUCH OF THE DETAILS IN TOMORROWS WEATHER WILL REVOLVE AROUND WHERE RESULTING OUTFLOW BOUNDARIES END UP AND HOW QUICKLY THE ATMOSPHERE CAN RECOVER. IF THE LAST FEW DAYS ARE ANY INDICATION...IT COULD TAKE UNTIL MID TO LATE AFTERNOON FOR DESTABILIZATION TO OCCUR. BY THIS TIME...RETURN FLOW WILL BE SPREADING NORTHEAST INTO THE REGION AS A SHORTWAVE CURRENTLY OVER COLORADO LIFTS INTO THE NORTHERN MISSISSIPPI VALLEY. DO NOT TRUST MODEL SOUNDINGS MUCH...BUT TEMPS IN THE LOW TO MID 80S AND DEWPOINTS IN THE UPPER 60S SHOULD YIELD AT LEAST 1000 J/KG OF CAPE. 0-6KM BULK SHEAR IS RATHER POOR AROUND 20 KTS...SO WILL BE TOUGH TO GET ANY ORGANIZED CONVECTION. BUT CANNOT RULE OUT AN ISOLATED MENTION IF THE INSTABILITY RECOVERS. HIGHS IN THE LOW TO MID 80S. .LONG TERM...TUESDAY NIGHT THROUGH MONDAY ISSUED AT 226 PM CDT MON JUN 24 2013 BRIEF PERIOD OF ZONAL FLOW WILL BE ACCOMPANIED BY PRIMARY SHORTWAVE FORECAST TO TRAVERSE THE WESTERN GREAT LAKES DURING THE MIDDLE OF THE WORK WEEK. THERAFTER...THE MEDIUM RANGE GUIDANCE CONTINUES TO ADVERTIZE PRONOUNCED RIDGING OVER THE WESTERN CONUS WITH DEEPENING DOWNSTREAM TROUGH ACROSS THE GREAT LAKES AND OHIO VALLEY. LOTS OF UNCERTAINTY WITH RESPECT TO THE DETAILS OF EMBEDDED DISTURBANCES WITHIN THE INCREASING NORTHWESTERLY FLOW OVER THE STATE LATE IN THE WORK WEEK. DAILY AVERAGE TEMPERATURES SHOULD REMAIN ABOVE NORMAL...THEN FALL OFF CLOSER TO NORMAL OR PERHAPS A LITTLE BELOW NORMAL BY THE WEEKEND. TUESDAY NIGHT AND WEDNESDAY... PRIMARY FORECAST CHALLENGE EARLY IN THE EXTENDED WILL BE TRYING TO NARROW DOWN THE TIMING AND LOCATION OF CONVECTIVE ACTIVITY ASSOCIATED WITH THE PRIMARY SHORTWAVE DISTURBANCE TUESDAY NIGHT AND WEDNESDAY. FORECAST CONFIDENCE FOR THIS PERIOD IS LOW. NOT GOING TO BUCK TRENDS PAST FEW DAYS AND WILL BET AGAINST QUASISTATIONARY FRONTAL BOUNDARY NEAR THE ILLINOIS-WISCONSIN MAKING MUCH NORTHWARD PROGRESS INTO THE FORECAST AREA TUESDAY NIGHT DESPITE RATHER ROBUST SOUTHWESTERLY LOW-LEVEL FLOW AHEAD OF THE APPROACHING SHORTWAVE. LATEST MODEL TRENDS SEEM TO SUGGEST THAT BULK OF DEEP CONVECTION WILL FIRE ALONG BOUNDARY TO OUR SOUTHWEST AROUND 00Z WEDNESDAY THEN HEAD MORE EASTERLY MAINLY ACROSS THE SOUTHERN THIRD OF THE STATE TUESDAY NIGHT...AS LLJ VEERS WSW BY 12Z WEDNESDAY. WILL TWEAK POPS SOMEWHAT TUESDAY PLACING HIGHEST PROBABALITIES ACROSS THE SOUTHERN THIRD OF THE FORECAST AREA AND TAPERING TO CHANCE ACROSS THE FAR NORTHEAST. IF THIS SCENARIO PLAYS OUT...FEEL BEST COMBINATION OF SHEAR AND INSTABLITY SUPPORTAIVE OF SEVERE STORMS WILL ALSO BE FOCUSED GENERALLY SOUTH OF HIGHWAY 29 TUESDAY NIGHT. PW VALUES FORECAST TO REMAIN QUITE HIGH...NEARLY 2SD ABOVE NORMAL TUESDAY NIGHT...THUS LOCALLY HEAVY RAINFALL IS ALSO THREAT. AS SHORTWAVE TROUGH AND ASSOCIATED SURFACE LOW MOVE ACROSS THE FORECAQST AREA WEDNESDAY EXPECT MORE WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY OVER THE ENTIRE FORECAST AREA. AT THIS TIME APPEARS WILL BE CONSIDERABLE CLOUDS AROUND DURING THE DAY ON WEDNESDAY THUS FEEL SEVERE THREAT WILL BE MARGINAL. AGAIN SOME POTENTIAL FOR LOCALLY HEAVY RAINFALL ESPECIALLY OVER THE FOX VALLEY. WILL TREND MAX TEMPS A FEW DEGREES LOWER WEDNESDAY ASSUMING MORE WIDESPREAD PRECIPITATION AND CLOUD COVER. /EB/ THURSDAY INTO THE WEEKEND... LONG RANGE MODELS IN AGREEMENT ON DEVELOPMENT OF HUGE UPPER RIDGE OVER 110 W LATITUDE AND TROF OVER GREAT LAKES. THIS SPELLS A SHOWERY PERIOD WITH TEMPS AOB NORMAL ACROSS REGION FRIDAY INTO MONDAY. BOTH ECMWF AND GFS SHOW SIGNS OF ADDITIONAL ENERGY DIGGING INTO TROF NEXT WEEK...KEEPING THE COOLISH WEATHER AROUND. /JKL/. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1228 PM CDT MON JUN 24 2013 A THUNDERSTORM COMPLEX OVER SOUTHERN MINNESOTA AND IOWA IS EXPECTED TO MOVE NORTHEAST THIS AFTERNOON INTO WISCONSIN. CURRENT TRENDS SUPPORT CENTRAL AND NORTHEAST WISCONSIN RECEIVING SHOWERS AND THUNDERSTORMS FROM THIS COMPLEX LATE THIS AFTERNOON AND INTO THE EVENING. CIGS/VSBYS WILL LIKELY FALL INTO THE MVFR RANGE WITHIN ANY THUNDERSTORMS. FOLLOWING THE PASSAGE OF THESE STORMS...WILL LIKELY SEE A BREAK BUT UNCERTAINTY WILL BE HIGH AS TO HOW LONG. ITS QUITE POSSIBLE THAT THE BREAK COULD LAST UNTIL TOMORROW AFTERNOON BEFORE THE NEXT AROUND OF SHOWERS AND STORMS ARRIVE. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......JKL AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
131 PM CDT MON JUN 24 2013 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 129 PM CDT MON JUN 24 2013 THIS IS A TOUGH ONE. CONFIDENCE WAS HIGHER THIS MORNING THAT A SIGNIFICANT FLOODING SET UP WAS IN PLACE TONIGHT. HOWEVER...THE MASSIVE AMOUNT OF CONVECTION OVER IOWA AND INTO NRN MO IS CRASHING CONFIDENCE LEVELS. IT APPEARS THE OVERNIGHT COULD BE ALMOST DRY. THE IDEAL SIGNIFICANT FLOODING SCENARIO IS IOWA BEING PRETTY CLEAN AT THIS POINT AND BUILDING INSTABILITY...VERY HIGH INSTABILITY. THEN...THE LOW-LEVEL JET BECOMING ACTIVE AND CONVERGENT ACROSS MOST OF SRN MN...WITH INDIVIDUAL STORMS TRACKING EAST. THIS HAD BEEN THE SIGNAL IN THE MODEL GUIDANCE SINCE YESTERDAY...BUT THIS IS NOT GOING TO VERIFY WITH THE CURRENT WIDESPREAD CONVECTION FOULING IT UP. THE WARM FRONT AND ISENTROPIC SLOPE IS BEING PUSHED FURTHER SOUTH /GUESS IT IS A COLD FRONT THEN/. THIS IS ACTUALLY GOOD NEWS AS WE WERE PRETTY WORRIED ABOUT A LONG AXIS FROM KFSD- KLSE OF PROLONGED LOW-LEVEL JET UP SLOPE AND CONVERGENCE OF AN UNSTABLE AIR MASS...AND DEEP WARM CLOUD REPEATING THUNDERSTORMS. IN FACT...THE MOST RECENT TWO RAP RUNS OF 16-17Z BOTH HAVE MIGRATED TOWARD THIS DRIER SCENARIO AND EVEN HAVE WESTERLY 850 MB FLOW OVERNIGHT. SO...WE ARE BEGINNING TO BELIEVE A MORE LIKELY OUTCOME MAY BE CONVECTION MOVING THROUGH THIS AFTERNOON AND EARLY EVENING...AND A RECOVERY PERIOD NEEDED BEFORE MORE WEATHER OCCURS. INSTABILITY SHIFTING NORTH INTO THE KFSD AREA LATE OVERNIGHT INITIATING CONVECTION IN NORTHWEST IA TUESDAY...SHIFTING EAST. BUT...IT COULD MEAN NO HIGHER END RAINFALL NUMBERS WE UPGRADED TO THIS MORNING...AND LESSER IMPACT FOR SURE. WE ARE TAKING A CAUTIOUS APPROACH ON THIS...BUT IT APPEARS LESS THREAT MAY BE PRESENTING ITSELF. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 415 AM CDT MON JUN 24 2013 FOR TUE NIGHT THRU WED NIGHT MODELS SHOW THE REMNANTS OF THE TROUGHING NOW OVER CA WILL LIFT INTO AND ACROSS THE UPPER MIDWEST. TREND CONTINUES TO FAVOR STRONGER OF THE EARLIER RUNS. WITH THIS BEING A LARGER SCALE FEATURE AND THE DECENT MODEL CONSISTENCY FCST CONFIDENCE FOR THIS PERIOD IS AVERAGE. AS THE STRONGER MID LEVEL TROUGH MOVES INTO THE UPPER MIDWEST TUE NIGHT THE PLAINS SFC LOW MOVES INTO MN/WI. LOWER LEVEL THERMO DYNAMIC FORCING/LIFT AND MOISTURE TRANSPORT REMAINS STRONG INTO THE AREA AHEAD OF THESE FEATURES. WHERE THE FRONT AHEAD OF THE LOW FROM TODAY/TUE ENDS UP WILL DETERMINE WHERE THE STRONGER LIFT WILL BE. MODEL CONSENSUS HAS IT SOMEWHERE OVER THE FCST AREA TUE NIGHT... THUS CARRIED HIGHEST SHRA/TSRA CHANCES IN THE 60-70 PERCENT RANGE OVER THE NORTHEAST 2/3 OF THE FCST AREA. PW VALUES REMAIN IN THE 1.5 TO 1.75 INCH RANGE WITH ANY STORMS CAPABLE OF PRODUCING HEAVY RAINS. AGAIN...WILL LIKELY NEED MORE FLASH FLOOD WATCHES FOR PORTIONS OF THE AREA INTO TUE NIGHT WITH POTENTIAL FOR ANOTHER 0.5 TO 1.5 INCHES...LOCALLY MORE...OF RAIN. ONCE THIS STRONGER MID LEVEL TROUGH PASSES TUE NIGHT/WED MORNING THE FLOW PATTERN OVER NOAM BEGINS TO CHANGE WITH RIDGING BUILDING OVER THE WESTERN CONUS AND INCREASING NORTHWEST FLOW ALOFT OVER THE UPPER MIDWEST. DRIER AIR AND HIGH PRESSURE WILL SLOWLY SPREAD INTO MN/IA/WI WED/WED NIGHT. SHRA/TSRA CHANCES WILL LINGER WED WITH THE SFC LOW-MID LEVEL TROUGH OVER THE REGION. SHRA/TSRA CHANCES DECREASE WED NIGHT AS HGTS RISE AND THE SFC-MID LEVEL LOW/TROUGH MOVE EAST OF THE AREA. DUE TO THE CONVECTION DETAIL UNCERTAINTIES...CONTINUED TO USE THE MODEL/ENSEMBLE CONSENSUS FOR LOWS/HIGHS IN THE TUE NIGHT TO WED NIGHT PERIOD. ONCE AGAIN NOT A LOT OF TIME SPENT LOOKING AT THE DAY 4-7 PERIOD. 24.00Z MEDIUM RANGE MODELS MAINTAIN A GOOD CONSENSUS FOR THE BUILDING WESTERN NOAM RIDGING AND EASTERN NOAM TROUGHING IN THE THU- SUN PERIOD...WHICH PUTS THE REGION UNDER INCREASING NORTHWEST FLOW ALOFT. THU-SUN SHAPING UP TO BE A DRIER PERIOD WITH TEMPERATURES COOLING TO NEAR OR A BIT BELOW NORMAL. FCST CONFIDENCE FOR THIS PERIOD LOOKS TO BE AVERAGE TO GOOD. DRIER HIGH PRESSURE BUILDS IN FOR THU-SUN...BUT PLENTY OF RESIDUAL LOW LEVEL MOISTURE AND MAXIMUM EVAPO-TRANSPIRATION FROM WELL WATERED VEGETATION AND WET SOILS APPEAR TO REMAIN...ALONG WITH STEEP LOW/ MID LEVEL LAPSE RATES AND SHORTWAVES RIPPLING THRU THE NORTHWEST FLOW ALOFT. THU-SUN TRENDING TO BE DRY DAYS BUT SOME SMALLER MAINLY DIURNAL SHRA/TSRA CHANCES TO PERSIST...AIDED BY THE PASSING SHORTWAVES FROM TIME TO TIME. MODEL/ENSEMBLE CONSENSUS FOR HIGHS/ LOWS IN THE DAY 4-7 PERIOD LOOK WELL TRENDED FOR NOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 129 PM CDT MON JUN 24 2013 PERIODS OF TSRA WILL OCCUR THROUGH ABOUT 00Z. THIS MAY NEED TO BE EXTENDED IN THE TAF SITES...WILL MONITOR...AS 18Z TAFS HAVE 2 HOURS OF TEMPO TSRA. MASSIVE CONVECTIVE COMPLEX ACROSS IA HAS REALLY IMPACTED TSRA FORECAST FOR THE OVERNIGHT HOURS. WAS THINKING THAT A MASSIVE RAIN EVENT WAS IN PLACE BUT WITH THE IA CONVECTION...MANY OF THE GOOD SET UP PARAMETERS ARE NOT AS FAVORABLE ANY LONGER OVERNIGHT. LATER FORECASTS MAY REMOVE THE TSRA TO LESSER HOURS OR IMPACT. CEILINGS WILL ALSO BE VERY DIFFICULT WITH MESSY...UNORGANIZED PATTERN THROUGH THE PERIOD. CONFIDENCE IS LOW IN THE TAF BEYOND 4-5 HOURS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ032>034-041>044- 053>055-061. MN...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR MNZ079-086>088- 094>096. IA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR IAZ008>011-018-019- 029-030. && $$ SHORT TERM...BAUMGARDT LONG TERM....RRS AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1228 PM CDT MON JUN 24 2013 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND TUESDAY ISSUED AT 444 AM CDT MON JUN 24 2013 THE CONTINUING SAGA ON WHERE AND WHEN FOR CONVECTION CONTINUES THIS MORNING. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY HINT AT WEAK BOUNDARY OVER NORTHEAST WI SEEN IN DEW POINTS. AREA OF DISORGANIZED TSTMS MOVING NORTH THROUGH IA AND WESTERN IL. STARTING TO SEE MORE MOVEMENT TO EAST OVER IL IN LATEST SCANS WHICH WOULD GO WITH MODELS PROJECTION OF LLVL JET SHIFTING MORE TO THE WEST AND WEAKENING BY 12Z. HRRR SEEMS TO HAVE BEST HANDLE ON CURRENT TRENDS...SHOWING ONLY SPOTTY CONVECTION OVER CWA TODAY MAINLY OVER THE SOUTH HALF. ALL MODELS STILL SHOWING VARIETY OF SOLUTIONS IN QPF PATTERN THROUGH THIS PERIOD. HAVE TRENDED TOWARD NAM TODAY GIVEN DRIER AIR WORKING IN AS SEEN IN SIG DROP IN PWATS ON MSP SOUNDING LAST EVENING. SFC BASED INSTABILITY STILL SIG 1-2K...THOUGH NOT SEEING ANY REAL TRIGGER/LIFT TODAY. WENT WITH SLIGHTS FOR LATE DAY CONVECTION SOUTH AND EAST ALONG LAKE BREEZE BOUNDARY. FORCING AND MOISTURE WORKS BACK INTO THE AREA THIS EVENING WITH STRENGTHENING LLVL FLOW POINTING INTO SOUTHWEST WI AFTER 06Z. ALSO SEEING SOME SUPPORT FROM RRQ OF JET MAX MOVING THROUGH LAKE SUPERIOR REGION. WILL GO WITH INCREASING CHANCE POPS TONIGHT HIGH CHANCE POPS TUE AS FGEN/ISENTROPIC LIFT MAXIMIZED OVER CWA FROM 12Z TO 18Z TUES. CWA REMAINS IN SLIGHT RISK AREA ON TUE. SHEAR BETTER SOUTH FOR SOME WIND CONCERNS. WBZERO HGTS RATHER HIGH FOR LARGE HAIL. WITH PWATS RETURNING TO 1.5 TO 2 INCHES AGAIN HEAVY RAIN MORE OF CONCERN. .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY ISSUED AT 444 AM CDT MON JUN 24 2013 500MB RIDGE EXPECTED TO BUILD ACROSS THE WESTERN UNITED STATES WHILE UPPER TROUGH DEEPENS AND POSSIBLY CLOSES OFF ACROSS THE WESTERN GREAT LAKES BY THE END OF THE WORK WEEK INTO NEXT WEEKEND. FORECAST ISSUES ALREADY AT THE START OF THE PERIOD TUESDAY NIGHT. HAVE CONCERNS ON THE PLACEMENT OF CONVECTION TUESDAY EVENING ACROSS NORTHERN WISCONSIN. BELIEF IS THAT THE AXIS OF HEAVIER PRECIPITATION TOO FAR NORTH. THINK BAND WILL BE FURTHER SOUTH AS FIRST COMPLEX OF STORMS LATE MONDAY NIGHT AND TUESDAY WILL PUSH AN OUTFLOW BOUNDARY SOUTHWARD THAN WHAT THE MODELS SHOW...SIMILAR TOO WHAT HAPPENED A FEW DAYS AGO. GFS QPF FIELD SEEMS REASONABLE BASED ON MY CURRENT THINKING. THIS COULD AFFECT THE RAIN CHANCES ACROSS THE NORTH TUESDAY EVENING. SOUTHERN SECTIONS OF THE FORECAST AREA WILL BE CLOSE ENOUGH TO STILL WARRANT LIKELY CHANCES. 500MB TROUGH SWINGS INTO THE AREA TOWARDS 12Z WEDNESDAY...WARRANTING LIKELY POPS EVEN ACROSS THE NORTH. UPPER TROUGH WILL SWING ACROSS THE AREA ON WEDNESDAY. RAISED POPS TO 50 TO 55 PERCENT...AND MAY BUMP THEM UP A LITTLE MORE BEFORE FORECAST ISSUANCE. THE UPPER TROUGH SHOULD SWING EAST INTO LOWER MICHIGAN WEDNESDAY NIGHT. THERE WILL STILL BE SOME LINGERING EVENING SHOWERS AND A FEW STORMS. MID LEVEL LAPSE RATES NOT IMPRESSIVE...THEREFORE ONLY EXPECTED ISOLATED NATURE OF ANY THUNDERSTORMS WEDNESDAY EVENING. NORTHWEST FLOW ALOFT WILL CONTINUE THURSDAY AND FRIDAY...ALTHOUGH A DEEPER 500MB TROUGH WILL SWING ACROSS THE AREA FRIDAY AFTERNOON AND FRIDAY NIGHT. WILL CONTINUE THE SMALL CHANCES FOR SHOWERS SATURDAY... BUT NOT TOO OPTIMISTIC WE WOULD SEE THEM AT THIS TIME SINCE UPPER TROUGH WILL WELL EAST OF THE AREA WITH BUILDING HEIGHTS. CANADIAN HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN ON SUNDAY...ALTHOUGH COULD NOT RULE OUT A FEW ISOLATED SHOWERS SUNDAY AFTERNOON. FOR THE MOST PART...VERIFICATION DATA HAS SHOWN WE AND NUMERICAL GUIDANCE HAS BEEN TOO WARM OF LATE. DID NUDGE TEMPERATURES DOWN A DEGREE OR TWO MOST PERIODS. WILL NEED TO WATCH WEDNESDAY...IF IT STAYS CLOUDY AND THERE IS A LOT OF RAIN AROUND DURING THE DAY... TEMPERATURES COULD STAY IN THE 70S. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1228 PM CDT MON JUN 24 2013 A THUNDERSTORM COMPLEX OVER SOUTHERN MINNESOTA AND IOWA IS EXPECTED TO MOVE NORTHEAST THIS AFTERNOON INTO WISCONSIN. CURRENT TRENDS SUPPORT CENTRAL AND NORTHEAST WISCONSIN RECEIVING SHOWERS AND THUNDERSTORMS FROM THIS COMPLEX LATE THIS AFTERNOON AND INTO THE EVENING. CIGS/VSBYS WILL LIKELY FALL INTO THE MVFR RANGE WITHIN ANY THUNDERSTORMS. FOLLOWING THE PASSAGE OF THESE STORMS...WILL LIKELY SEE A BREAK BUT UNCERTAINTY WILL BE HIGH AS TO HOW LONG. ITS QUITE POSSIBLE THAT THE BREAK COULD LAST UNTIL TOMORROW AFTERNOON BEFORE THE NEXT AROUND OF SHOWERS AND STORMS ARRIVE. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....TE LONG TERM......ECKBERG AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1110 AM CDT MON JUN 24 2013 .UPDATE...NO CHANGES TO FLASH FLOOD WATCH HEADLINE. MAIN ACTION IN IOWA. AIRMASS RELATIVELY MORE STABLE HERE IN SRN WI DUE TO CLOUD DEBRIS FROM LATE NIGHT/EARLY MRNG MCS. NEW HRRR PUTS ERN IA AND NRN IL MORE IN THE HOT SPOT THIS AFTERNOON AND THIS MAKES SENSE GIVEN THE OUTLAW OF WHERE BETTER AIRMASS RESIDES TO SUPPORT SUSTAINED STRONGER CONVECTION. MODELS ARE ALL SHOWING MORE CONVECTION RE-FIRING TONIGHT ACRS SRN WI WITH ANOTHER 850 JET CORE ARRIVING FROM THE SOUTHWEST...BUT LIKE LAST NIGHT WILL HAVE TO SEE HOW ALL THIS ONGOING CONVECTION AFFECTS EFFECTIVE BOUNDARY POSITION/AIRMASS CHARACTERISTICS AS WE HEAD INTO THE NIGHT. ALL IN ALL FLASH FLOOD WATCH STILL LOOKS OK. PC && .AVIATION/18Z TAFS/...VFR CEILINGS FOR MUCH OF THE PERIOD. CONVECTIVE TRENDS SUGGEST MAIN ACTION IN IOWA WILL MORE THAN LIKELY AFFECT ERN IA AND NRN IL INTO THE EARLY EVENING...POSSIBLY GRAZING THE FAR SOUTH...PER HRRR. POTENTIAL FOR CONVECTION TONIGHT WILL DEPEND ON HOW THE ONGOING STORMS IN IOWA DISTRIBUTES BOUNDARIES AND HOW THESE INTERACT WITH RENEWED 850 JET FOR THE EVENING AND OVERNIGHT. PC && .PREV DISCUSSION... /ISSUED 412 AM CDT MON JUN 24 2013/ SHORT TERM... TODAY AND TONIGHT-FORECAST CONFIDENCE MEDIUM. FIRST CONCERN IS ONGOING MCS IN IOWA ON NOSE OF LOW LEVEL JET. MODELS POINT NOSE OF JET FARTHER NORTH AND EAST DURING THE EARLY MORNING SO THIS WILL COMING INTO MAINLY SOUTHWEST PARTS OF THE AREA THAT WERE POUNDED BY HEAVY RAIN A COUPLE OF DAYS AGO. SEEMS THAT RIGHT ENTRANCE REGION OF 90 KNOT 250 MB WIND MAX IN MN MAY BE AIDING THESE STORMS. OTHERWISE PERSISTENT 850-700 MB WARM ADVECTION WITHIN BROAD 850 MB LOW LEVEL JET AND MOIST AIRMASS SHOULD YIELD SCATTERED TO NUMEROUS THUNDERSTORMS TODAY AND TONIGHT. TIMING AND LOCATION DIFFICULT AS USUAL WITH CONVECTION AND ASSOCIATED MESOSCALE OUTFLOW BOUNDARIES BUT PRECIPITABLE WATER VALUES WILL BE IN 130-160% OF NORMAL RANGE SO POTENTIAL FOR HEAVY RAIN TO CONTINUE. FRANKLY YOU COULD EXTEND THE FLASH FLOOD WATCH UNTIL WEDNESDAY MORNING BUT AFTER DISCUSSING THE MATTER WITH SURROUNDING WFOS SEEMS THAT WE SHOULD FOCUS ON THE NEXT 12-24 HOURS. AFTER MUCH DELIBERATION DECIDED TO MATCH UP WITH ARX AND EXTEND THE WATCH UNTIL 10 AM ON TUESDAY. THESE SITUATIONS ARE ALWAYS DIFFICULT BECAUSE TRYING TO FORECAST QPF FOR THE WHOLE AREA WITHOUT KNOWING WHICH COUPLE OF COUNTIES WILL GET HIT WITH 3-5 INCHES OF RAIN OR MORE IS ALMOST IMPOSSIBLE. SO WE BROAD BRUSH 0.50 TO 1.00" QPF KNOWING THAT SOME AREAS WILL GET VERY LITTLE RAIN AND OTHERS MUCH MORE. MARGINAL HAIL AND WIND THREAT EXISTS BUT SHOULD BE RELATIVELY MINOR IN COMPARISON TO TUESDAY EVENING. TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE MEDIUM. UNSETTLED PERIOD WITH MODELS PUTTING OUT A LOT OF CONVECTIVE DRIVEN PRECIP AS THE WET AND HUMID PATTERN CONTINUES. MODELS ARE IN A GENERAL/BROAD AGREEMENT REGARDING THE NEAR-ZONAL PATTERN AND A FEW SHORT WAVE TROUGHS RIPPLING THROUGH. THE MAIN CONCERN IS TUESDAY INTO WEDNESDAY. A SHORT WAVE TROUGH WILL BEGIN TO MOVE ACROSS THE CWA LATE TUESDAY...WHERE THE BEST CHANCES FOR PRECIP ARE. LIKELY POPS ACROSS MUCH OF THE CWA FROM 0Z TO 12Z WEDNESDAY WHERE DECENT SYNOPTIC ASCENT...WITH Q-VECTOR DIVG AND LOW-LEVEL WAA...WILL COINCIDE WITH A LLJ THAT WILL INITIAL TAKE AIM AT SOUTH CENTRAL WI. THE LLJ THEN BECOMES MORE WSW BY 12Z WED. SFC LOW PRESSURE TROUGH AND BOUNDARY EXPECTED TO BE OVER CENTRAL WI AT THIS TIME TUESDAY AFTERNOON. GIVEN THE SETUP...DO CONCUR WITH PREV FCST DISCUSSION CONCEPTUALLY ON A MCS TRAVERSING THE CWA GIVEN THE LLJS FOCUS. FLASH FLOOD/HEAVY RAIN POTENTIAL THIS PERIOD...WITH HIGH PRECIPITABLE WATER VALUES AROUND 1.7-1.9 AT ITS PEAK IN THE EVENING TUES/EARLY WED. STRONG THUNDERSTORM THREAT AS WELL TUESDAY AND WEDNESDAY GIVEN ENVIRONMENT WITH AMPLE INSTABILITY AND MOISTURE. OF NOTE...DEEP LAYER SHEAR MORE ROBUST THAN WE HAVE SEEN PREVIOUSLY THE LAST FEW DAYS...WITH VALUES AROUND 20-30 KTS. THUS...A DECENT SIGNAL IN SIGSVR ALSO. THE POTENTIAL FOR A WIND AND HAIL THREAT DOES EXIST. A SLIGHT RISK IS PRESENT FOR ALL OF THE CWA IN SPCS DAY 2 CATEGORICAL OUTLOOK THIS MORNING. SPC OUTLOOK ON DAY 3 HAS THE EASTERN TWO THIRDS OF THE CWA IN SLIGHT RISK ALSO. HIGHS WERE LOWERED A BIT TUES AND WED...AND LEANED MORE TOWARDS THE COOLER CONSENSUS GUIDANCE GIVEN THE SKY COVER ANTICIPATED AND MOIST COLUMNS. LONG TERM... THURSDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE MEDIUM. COOLING TREND BEGINS FRIDAY/THIS WEEKEND. MODELS IN AGREEMENT WITH THE FLOW BECOMING MORE AMPLIFIED WITH A LONG WAVE TROUGH DIGGING INTO THE GREAT LAKES REGION. GFS CONTINUES TO DIG NOTABLY STRONGER WITH LARGER HT FALLS COMPARED TO NAM AND ECMWF. NW FLOW THEN TAKES OVER THIS WEEKEND WITH COOLER TEMPS ALOFT BROUGHT TOWARDS WISCONSIN. SFC HIGH PRESSURE BEGINS TO BUILDS IN SUNDAY AND PERSIST THROUGH THE BEGINNING OF MONDAY. AVIATION/12Z TAFS/... AS IS TYPICAL IN CONVECTIVE SITUATIONS...MUCH OF THE TIME WILL BE VFR WITH BRIEF AND DIFFICULT TO TIME PERIODS OF MVFR OR LOWER. PRETTY MUCH A COIN TOSS PROBABILITY NEXT 24 HOURS SO WILL BE CONSERVATIVE. SEEMS THAT MORNING MCS MOVING OUT OF IOWA AND NORTHERN ILLINOIS WILL MAINLY JUST BRUSH THE TAF SITES BUT SEVERAL ROUNDS ARE POSSIBLE BUT ESPECIALLY TONIGHT AS AFTERNOON ACTIVITY MOVES ON NOSE OF LOW LEVEL JET FROM IOWA AND MINNESOTA INTO WISCONSIN. PESKY MVFR FOG IS POSSIBLE THIS MORNING AND AGAIN TONIGHT WITH HIGH DEW POINTS BUT PROBABILITY IS A TAD LOW TO PUT IN TAFS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ046-047-056-057- 062-063-067>069. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...CRAVEN TUESDAY THROUGH SUNDAY...ET