Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/08/14


AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
926 PM CDT MON JUL 7 2014 .UPDATE... QUICK UPDATE TO THE CURRENT FORECAST BASED ON THE CONVECTIVE ACTIVITY CURRENTLY ONGOING ACROSS PORTIONS OF NE KANSAS AND N MISSOURI. THIS ACTIVITY IS EXPECTED TO TRACK SE DURING THE OVERNIGHT HOURS AND WILL APPROACH NE PARTS OF THE FORECAST AREA...ALTHOUGH IN QUITE A WEAKER STATE THAN WHAT IS BEING SEEN ATTM. HAVE ADDED POPS TO NORTHERN/NORTHEASTERN PARTS OF THE CWA FROM 06Z-18Z AS THE COMPLEX WILL LIKELY APPROACH THE AR/MO BORDER BETWEEN 08Z-12Z. && .PREV DISCUSSION... /ISSUED 635 PM CDT MON JUL 7 2014/ AVIATION... CONVECTION HAS DIED OUT IN NWRN AND SERN PARTS OF AR...AND SHRA/TSRA IN ERN MO WILL PASS OFF TO THE EAST OF AR TAF SITES. THUS...NO CONVECTION INCLUDED IN TAFS THIS EVENING. CONVECTION DEVELOPING LATER TONIGHT IN MO STANDS A CHANCE OF MAKING IT TO KHRO AND KBPK AROUND SUNRISE...SO INCLUDED VCTS AT THESE TWO SITES FOR THIS POSSIBILITY. SCT CU FORMING AROUND MIDMORNING TUE. BELIEVE TS ON TUE WILL REMAIN N OF CENTRAL AR DURING THIS FORECAST PERIOD...BUT NAM DOES SUGGEST THAT SOME TS COULD MAKE IT TO CENTRAL AR SOON AFTER THE END OF THE FORECAST PERIOD. PREV DISCUSSION... /ISSUED 227 PM CDT MON JUL 7 2014/ SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT SHOWERS CONTINUE OVER THE NORTHEAST AND CENTRAL SECTIONS AT THIS TIME AS A WEAK IMPULSE IS MOVING THROUGH. DO NOT SEE THE NEED TO CARRY ANY ADDITIONAL POPS WITH THIS FEATURE THIS EVENING OR OVERNIGHT AS THE HRRR MODEL WHICH REALLY HANDLED THIS DISTURBANCE WELL SHOWS NO ADDITIONAL DEVELOPMENT. OTHERWISE...THE RELATIVELY DRY AIR MASS THAT WAS ENJOYED OVER THE WEEKEND IS JUST A MEMORY AS GULF MOISTURE SURGES BACK INTO THE AREA COURTESY OF SOUTHERLY WINDS. MODELS REMAIN GENERALLY CONSISTENT IN THEIR HANDLING OF A LONG WAVE TROUGH...CLEARLY VISIBLE ON MOISTURE CHANNEL IMAGERY OVER THE UPPER GREAT LAKES AT THIS TIME AND ITS ASSOCIATED FRONT. IF ANYTHING THE ECMWF HAS BEEN SLIGHTLY MORE CONSISTENT VERSUS OTHER SHORT TERM MODELS AND WILL LEAN IN THAT MODELS DIRECTION THIS AFTERNOON. LATEST SURFACE ANALYSIS PLACES SURFACE LOW PRESSURE OVER SOUTHERN QUEBEC WITH A TRAILING COLD FRONT EXTENDING THROUGH THE CENTRAL PART OF MISSOURI. AS THE PARENT LOW AND TROUGH LIFT TO THE EAST AND NORTHEAST...FRONT WILL SINK TOWARDS THE STATE. BEST GUESS ON THE TIMING WOULD TAKE THE BOUNDARY ALONG THE MISSOURI BORDER LATE TUESDAY AND THEN INTO CENTRAL ARKANSAS BY EARLY WEDNESDAY. SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE BOUNDARY BUT RAINFALL AMOUNTS DO NOT APPEAR TO BE EXCESSIVE. FORECAST GETS A TOUCH MORE MUDDLED AFTER THAT AS THERE IS SOME DISAGREEMENT WHERE THIS BOUNDARY ENDS UP STALLING. THE GENERAL CONSENSUS IS IT WILL BE SOMEWHERE OVER THE SOUTH AND THIS IS HOW THE FORECAST WILL TREND FOR THE REMAINDER OF THE PERIOD. WITH INCREASED CLOUD COVER AND AT LEAST SOME PRECIPITATION IN THE AREA...TEMPERATURES WILL LIKELY BE JUST A BIT BELOW GUIDANCE BUT STILL CLOSE TO WHERE THEY SHOULD BE FOR THIS TIME OF THE YEAR. LONG TERM...FRIDAY THROUGH MONDAY... MUCH OF THE NATURAL STATE WILL BE UNDER INFLUENCE OF AN UPPER RIDGE AT THE START OF THE LONG TERM PERIOD...WHICH WILL ALLOW TEMPS TO BE JUST ABOVE NORMAL...AND RAIN CHANCES FAIRLY LOW EARLY IN THE PERIOD. WHILE THE CENTER OF THE UPPER RIDGE WILL BE WEST OF THE REGION...WILL SEE SEE SIGNIFICANT ENOUGH INFLUENCE TO HAVE TEMPS FRI THROUGH SUN IN THE 90S FOR MOST LOCATIONS. THERE COULD EVEN BE A FEW SPOTS ACROSS THE WRN COUNTIES GETTING CLOSE TO THE TRIPLE DIGITS ON SAT. HOWEVER...HEAT INDEX VALUES WILL LIKELY CREST THE TRIP DIGIT MARK BY THE WEEKEND...ESPECIALLY ACROSS WRN AND SWRN SECTIONS OF THE AREA. RAIN CHANCES WILL INITIALLY BE LIMITED TO DIURNALLY DRIVEN ISOLATED CONVECTION FRI INTO SAT. BY LATE SUN AND INTO MON...THE UPPER FLOW WILL TRANSITION TO A MORE NW FLOW OVER THE STATE...WITH A COLD FRONT DROPPING SOUTH TOWARDS THE STATE. THIS FRONT WILL BRING BETTER CHANCES FOR PRECIP BY THE END OF THE FORECAST...AS WELL AS RESULTING LOWER TEMPS TO AROUND OR EVEN BELOW NORMAL BY EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... BATESVILLE AR 73 91 71 86 / 20 40 40 30 CAMDEN AR 71 95 73 93 / 0 10 20 40 HARRISON AR 72 90 69 85 / 10 30 50 20 HOT SPRINGS AR 72 94 73 91 / 10 10 40 40 LITTLE ROCK AR 72 94 73 89 / 10 10 40 40 MONTICELLO AR 71 95 73 92 / 0 10 30 40 MOUNT IDA AR 72 94 73 90 / 10 10 40 40 MOUNTAIN HOME AR 72 90 70 85 / 20 40 50 20 NEWPORT AR 73 92 72 86 / 10 40 50 30 PINE BLUFF AR 72 94 73 91 / 10 10 30 40 RUSSELLVILLE AR 72 93 72 88 / 10 20 50 40 SEARCY AR 73 93 72 87 / 10 20 50 40 STUTTGART AR 73 94 73 88 / 10 20 40 40 && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 226
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
635 PM CDT MON JUL 7 2014 .AVIATION... CONVECTION HAS DIED OUT IN NWRN AND SERN PARTS OF AR...AND SHRA/TSRA IN ERN MO WILL PASS OFF TO THE EAST OF AR TAF SITES. THUS...NO CONVECTION INCLUDED IN TAFS THIS EVENING. CONVECTION DEVELOPING LATER TONIGHT IN MO STANDS A CHANCE OF MAKING IT TO KHRO AND KBPK AROUND SUNRISE...SO INCLUDED VCTS AT THESE TWO SITES FOR THIS POSSIBILITY. SCT CU FORMING AROUND MIDMORNING TUE. BELIEVE TS ON TUE WILL REMAIN N OF CENTRAL AR DURING THIS FORECAST PERIOD...BUT NAM DOES SUGGEST THAT SOME TS COULD MAKE IT TO CENTRAL AR SOON AFTER THE END OF THE FORECAST PERIOD. && .PREV DISCUSSION... /ISSUED 227 PM CDT MON JUL 7 2014/ SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT SHOWERS CONTINUE OVER THE NORTHEAST AND CENTRAL SECTIONS AT THIS TIME AS A WEAK IMPULSE IS MOVING THROUGH. DO NOT SEE THE NEED TO CARRY ANY ADDITIONAL POPS WITH THIS FEATURE THIS EVENING OR OVERNIGHT AS THE HRRR MODEL WHICH REALLY HANDLED THIS DISTURBANCE WELL SHOWS NO ADDITIONAL DEVELOPMENT. OTHERWISE...THE RELATIVELY DRY AIR MASS THAT WAS ENJOYED OVER THE WEEKEND IS JUST A MEMORY AS GULF MOISTURE SURGES BACK INTO THE AREA COURTESY OF SOUTHERLY WINDS. MODELS REMAIN GENERALLY CONSISTENT IN THEIR HANDLING OF A LONG WAVE TROUGH...CLEARLY VISIBLE ON MOISTURE CHANNEL IMAGERY OVER THE UPPER GREAT LAKES AT THIS TIME AND ITS ASSOCIATED FRONT. IF ANYTHING THE ECMWF HAS BEEN SLIGHTLY MORE CONSISTENT VERSUS OTHER SHORT TERM MODELS AND WILL LEAN IN THAT MODELS DIRECTION THIS AFTERNOON. LATEST SURFACE ANALYSIS PLACES SURFACE LOW PRESSURE OVER SOUTHERN QUEBEC WITH A TRAILING COLD FRONT EXTENDING THROUGH THE CENTRAL PART OF MISSOURI. AS THE PARENT LOW AND TROUGH LIFT TO THE EAST AND NORTHEAST...FRONT WILL SINK TOWARDS THE STATE. BEST GUESS ON THE TIMING WOULD TAKE THE BOUNDARY ALONG THE MISSOURI BORDER LATE TUESDAY AND THEN INTO CENTRAL ARKANSAS BY EARLY WEDNESDAY. SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE BOUNDARY BUT RAINFALL AMOUNTS DO NOT APPEAR TO BE EXCESSIVE. FORECAST GETS A TOUCH MORE MUDDLED AFTER THAT AS THERE IS SOME DISAGREEMENT WHERE THIS BOUNDARY ENDS UP STALLING. THE GENERAL CONSENSUS IS IT WILL BE SOMEWHERE OVER THE SOUTH AND THIS IS HOW THE FORECAST WILL TREND FOR THE REMAINDER OF THE PERIOD. WITH INCREASED CLOUD COVER AND AT LEAST SOME PRECIPITATION IN THE AREA...TEMPERATURES WILL LIKELY BE JUST A BIT BELOW GUIDANCE BUT STILL CLOSE TO WHERE THEY SHOULD BE FOR THIS TIME OF THE YEAR. LONG TERM...FRIDAY THROUGH MONDAY... MUCH OF THE NATURAL STATE WILL BE UNDER INFLUENCE OF AN UPPER RIDGE AT THE START OF THE LONG TERM PERIOD...WHICH WILL ALLOW TEMPS TO BE JUST ABOVE NORMAL...AND RAIN CHANCES FAIRLY LOW EARLY IN THE PERIOD. WHILE THE CENTER OF THE UPPER RIDGE WILL BE WEST OF THE REGION...WILL SEE SEE SIGNIFICANT ENOUGH INFLUENCE TO HAVE TEMPS FRI THROUGH SUN IN THE 90S FOR MOST LOCATIONS. THERE COULD EVEN BE A FEW SPOTS ACROSS THE WRN COUNTIES GETTING CLOSE TO THE TRIPLE DIGITS ON SAT. HOWEVER...HEAT INDEX VALUES WILL LIKELY CREST THE TRIP DIGIT MARK BY THE WEEKEND...ESPECIALLY ACROSS WRN AND SWRN SECTIONS OF THE AREA. RAIN CHANCES WILL INITIALLY BE LIMITED TO DIURNALLY DRIVEN ISOLATED CONVECTION FRI INTO SAT. BY LATE SUN AND INTO MON...THE UPPER FLOW WILL TRANSITION TO A MORE NW FLOW OVER THE STATE...WITH A COLD FRONT DROPPING SOUTH TOWARDS THE STATE. THIS FRONT WILL BRING BETTER CHANCES FOR PRECIP BY THE END OF THE FORECAST...AS WELL AS RESULTING LOWER TEMPS TO AROUND OR EVEN BELOW NORMAL BY EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... BATESVILLE AR 73 91 71 86 / 20 40 40 30 CAMDEN AR 71 95 73 93 / 0 10 20 40 HARRISON AR 72 90 69 85 / 10 30 50 20 HOT SPRINGS AR 72 94 73 91 / 10 10 40 40 LITTLE ROCK AR 72 94 73 89 / 10 10 40 40 MONTICELLO AR 71 95 73 92 / 0 10 30 40 MOUNT IDA AR 72 94 73 90 / 10 10 40 40 MOUNTAIN HOME AR 72 90 70 85 / 20 40 50 20 NEWPORT AR 73 92 72 86 / 10 40 50 30 PINE BLUFF AR 72 94 73 91 / 10 10 30 40 RUSSELLVILLE AR 72 93 72 88 / 10 20 50 40 SEARCY AR 73 93 72 87 / 10 20 50 40 STUTTGART AR 73 94 73 88 / 10 20 40 40 && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...28
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
245 PM CDT SUN JUL 6 2014 .SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT SFC HIGH PRES WAS SITUATED TO THE E OF AR THIS AFTN...ALLOWING SLY WINDS TO RETURN TO THE REGION. LOW LVL MOISTURE HAS RETURNED IN EARNEST OVR THE LAST 24 HOURS AS NOTED WITH LATEST DEWPOINT READINGS IN THE MID 60S TO LOWER 70S ACRS THE FA. CONVECTIVE COMPLEX THAT WAS NOTED ACRS SWRN MO EARLIER IN THE DAY HAS CONTD TO WEAKEN. THE RESULTING MCV IS EXPECTED TO DRIFT SLOLY TO THE SE INTO THE EVENING. THE HRRR CONTS TO HAVE A GOOD HANDLE ON THIS FEATURE AND DOES INDC SOME ADDITIONAL CONVECTION FORMING ACRS PARTS OF NRN AR THRU THE LATE AFTN. WL CONT TO MONITOR RADAR TRENDS AND DECIDE BEFORE ISSUANCE TIME WHETHER TO INCLUDE SOME POPS THIS EVENING IN THE N. THE WX PATTERN WL BCM MORE UNSETTLED HEADING INTO THE MIDDLE OF THE NEW WORK WEEK. HIGH PRES ALOFT WL SHIFT FURTHER WWD AND SET UP OVR THE WRN PART OF THE NATION. THE RESULTING NWLY FLOW ALOFT WL BRING A FNTL BNDRY SWD INTO AR STARTING LATE TUE/TUE NGT...WITH THE BNDRY TO MEANDER OVR THE FA THRU THE REST OF THE SHORT TERM. AS A RESULT...CONVECTIVE CHCS WL BE ON THE UPSWING FM N TO S...ESP LATE TUE THRU WED. WHILE WIDESPREAD SVR WX IS NOT ANTICIPATED...A FEW STRONG/SVR STORMS WL BE POSSIBLE TUE NGT AND WED. SHLD THE BNDRY HOLD UP LONGER OVR A GIVEN AREA...LOCALLY HEAVY RAINFALL WL BE A CONCERN. DID NOT STRAY TOO FAR FM MOS TEMPS THRU THE PD. && .LONG TERM...THURSDAY THROUGH SUNDAY A STALLED FRONTAL BOUNDARY WILL BE PRESENT ACROSS ARKANSAS AS THE PERIOD BEGINS ON THURSDAY. BROAD-BRUSHED CHANCE POPS ARE IN THE FORECAST TO ACCOUNT FOR EXPECTED SCATTERED SHOWERS AND THUNDERSTORMS ON THURSDAY...POSSIBLY LINGERING INTO FRIDAY IN THE EAST. UPPER LEVEL HIGH PRESSURE WILL BEGIN STRENGTHENING TO THE WEST OF ARKANSAS ON FRIDAY...PUSHING THE REMNANT BOUNDARY OFF TO THE NORTHEAST AND LIKELY BRINGING RAIN CHANCES TO AN END FOR THE FORECAST AREA HEADING INTO NEXT WEEKEND. TEMPERATURES WILL BE AROUND OR POSSIBLY SLIGHTLY BELOW NORMAL ON THURSDAY DUE TO CLOUDS AND RAINFALL. HOWEVER...WITH A NOTABLE STRENGTHENING OF THE UPPER RIDGE AND SOUTHWEST WINDS IN PLACE IN THE LOWEST SEVERAL THOUSAND FEET OF THE ATMOSPHERE...A WARMING TREND WILL BEGIN THAT WILL CARRY THROUGH NEXT WEEKEND. SOME MODEL GUIDANCE IS EVEN HINTING AT THE POSSIBILITY OF TRIPLE DIGIT HIGHS NEXT SATURDAY AND SUNDAY. HOWEVER...WILL JUST ADVERTISE WIDESPREAD MID 90S FOR THE TIME BEING. RECENT RAINS AS WELL AS THOSE EXPECTED THIS WEEK SHOULD LIMIT THE POTENTIAL TO GET TO 100 DEGREES...MUCH LESS BEYOND. NEVERTHELESS...IT DOES SEEM LIKE NEXT WEEKEND MAY FEATURE OPPRESSIVE HEAT. TO END ON A POSITIVE NOTE THOUGH...LOOKING JUST BEYOND THE 7 DAY FORECAST THERE ARE INDICATIONS THAT ANY OPPRESSIVE HEAT MAY BE SHORT LIVED AND A RETURN TO NORMAL OR POSSIBLY BELOW NORMAL TEMPERATURES COULD OCCUR. TIME WILL TELL. && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...44 / LONG TERM...64
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
107 PM PDT SUN JUL 6 2014 .SYNOPSIS... HIGH PRESSURE ANCHORED OVER THE FOUR CORNERS REGION WILL KEEP ABOVE NORMAL TEMPERATURES ACROSS THE CENTRAL CALIFORNIA INTERIOR THROUGH MUCH OF NEXT WEEK. SHOWERS AND THUNDERSTORMS WILL FORM OVER THE SIERRA NEVADA AS TROPICAL MOISTURE FLOWS OVER THE AREA. && .DISCUSSION...UPPER LEVEL HIGH PRESSURE OVER THE FOUR CORNERS REGION CONTINUES TO BRING ABUNDANT MONSOONAL MOISTURE INTO AZ AND NV...AND EVEN INTO SOUTHERN AND CENTRAL CA. THUNDERSTORMS HAVE FORMED OVER THE SIERRA CREST IN TULARE COUNTY...BUT HAVE BEEN VERY ISOLATED IN NATURE. THE SHORT TERM MODELS INCLUDING THE HRRR AND THE NAM INDICATE THAT THESE STORMS WILL CONTINUE INTO THE EARLY EVENING HOURS AND PEAK AROUND THE 22Z...THE WARMEST PART OF THE DAY. INSTABILITY IS MARGINAL AT BEST...SO THUNDERSTORM ACTIVITY WILL LIKELY REMAIN ISOLATED...AND MAY NOT EVEN IMPACT THE KERN COUNTY MOUNTAINS AND DESERT AS CURRENTLY FORECAST. FORECASTER CONFIDENCE IS MEDIUM TO LOW WITH TIMING AND LOCATION OF THUNDERSTORMS. OTHERWISE...THE VALLEY IS ON ITS WAY TO ANOTHER TRIPLE DIGIT DAY...WITH MOST LOCATIONS IN THE MID TO UPPER 90S. TEMPERATURES WILL WARM INTO THE 100 TO 105 DEGREE MARK FOR MANY VALLEY LOCATIONS...NEARLY IDENTICAL TO THOSE OBSERVED YESTERDAY AND BETWEEN 5 AND 10 DEGREES ABOVE NORMAL FOR THE BEGINNING OF JULY. LITTLE CHANGE IN THE OVERALL SYNOPTIC PATTERN WITH THE FOUR CORNERS UPPER HIGH REMAINING FIRMLY IN PLACE INTO AT LEAST THURSDAY. THIS WILL BRING THE SLIGHT CHANCE OF THUNDERSTORMS TO THE SIERRA CREST EACH AFTERNOON/EVENING AND TRIPLE DIGIT TEMPERATURES TO THE VALLEY AND DESERT LOCATIONS. THE UPPER RIDGE SHIFTS SLOWLY EAST THURSDAY INTO FRIDAY...SHIFTING THE THUNDERSTORM MOISTURE SOURCE TO THE EAST AS WELL. ALTHOUGH WE DO HAVE A SLIGHT CHANCE FOR THUNDERSTORMS OVER THE CREST ON FRIDAY...CONFIDENCE IS LOW. ANOTHER RESULT OF THE UPPER HIGH SHIFTING EAST WILL BE A VERY SUBTLE COOLING TREND THROUGH THE AREA. ON FRIDAY...TEMPERATURES WILL STRUGGLE TO REACH THE 100 DEGREE MARK...BUT WILL LIKELY WARM INTO THE UPPER 90S. REGARDLESS...IT WILL HARDLY BE NOTICEABLE...AND STILL SLIGHTLY ABOVE NORMAL FOR THE MIDDLE OF JULY. && .AVIATION... SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED OVER THE KERN COUNTY DESERTS...TEHACHAPI MOUNTAINS AND THE HIGH COUNTRY OF THE SOUTHERN SIERRA NEVADA THRU 06Z MON AND OVER THE HIGH COUNTRY OF THE SOUTHERN SIERRA NEVADA AFTER 20Z MON. LOCAL IFR CONDITIONS WILL BE POSSIBLE NEAR ANY THUNDERSTORMS THAT DEVELOP. OTHERWISE VFR CONDITIONS WILL PREVAIL OVER THE REGION DURING THE NEXT 24 HOURS. && .AIR QUALITY ISSUES... NONE. && .CERTAINTY... THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM. THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM. CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL INFORMATION AND/OR TO PROVIDE FEEDBACK. && .CLIMATE... RECORDS SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR KFAT 07-06 111:2007 83:1903 78:2007 50:1955 KFAT 07-07 111:1905 84:1891 76:1936 53:1903 KFAT 07-08 115:1905 84:1983 81:1896 51:1891 KBFL 07-06 116:1913 85:1955 81:2011 52:1915 KBFL 07-07 114:1905 85:1983 81:1968 46:1903 KBFL 07-08 114:1905 85:1983 79:1907 50:1899 && .HNX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ PUBLIC...RILEY AVN/FW...DS SYNOPSIS...BSO WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
825 PM MDT MON JUL 7 2014 .UPDATE... ISSUED AT 825 PM MDT MON JUL 7 2014 UPDATED TO INCREASE POPS ACROSS THE PALMER DIVIDE AND THE FAR SE PLAINS THIS EVENING AND OVERNIGHT. LATEST NAM IS PEGGING THE POTENTIAL FOR LOCALLY HEAVY RAINFALL ACROSS THE PIKES PEAK REGION AND LOWER EASTERN SLOPES OF THE WET MTS AND SOUTHERN SANGRE DE CRISTO MTS LATER TONIGHT...AS SFC-H7 WINDS BECOME WEAK EAST TO NORTHEAST BEHIND PASSING COLD FRONT SLIDING ACROSS NORTHEASTERN COLORADO AT THIS TIME. LATEST HIGHER RESOLUTION RAP AND HRRR ARE KEEPING SFC-H7 FLOW MORE NORTHERLY THROUGH THE OVERNIGHT AND WHICH WOULD TEND TO FAVOR THE RATON MESA REGION FOR LOCALLY HEAVY RAINFALL. WITH DEW PTS IN THE 50S TO LOWER 60S ACROSS NORTHEASTERN COLORADO...AND THE POTENTIAL FOR REDEVELOPING AND TRAINING OF STORMS ACROSS THE EASTERN MTS...THERE WILL BE AN INCREASED CONCERN FOR FLASH FLOODING ON AREA BURN SCARS THROUGH THE OVERNIGHT HOURS. UPDATE ISSUED AT 451 PM MDT MON JUL 7 2014 QUICK UPDATE TO SPREAD POPS FURTHER SOUTH ACROSS THE PLAINS WITH STORMS FIRING ON OUTFLOWS. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 239 PM MDT MON JUL 7 2014 SLIGHTLY MORE CONVECTION OCCURRING THIS AFTERNOON OVER THE AREA...AS AIR MASS HAS MOISTENED SOMEWHAT OVER THE PAST 24 HRS. SOUNDINGS STILL SUGGEST DRY LOW LEVELS AND RATHER HIGH CLOUD BASES...SO SUSPECT MOST STORMS AREN`T PRODUCING MUCH RAINFALL...EVEN OVER THE HIGHER TERRAIN. SURFACE COLD FRONT ALONG/JUST SOUTH OF THE PALMER DIVIDE SHOWS UP NICELY IN RADAR/SATELLITE IMAGERY AS OF 21Z...THOUGH COOLER AIR AND STRONGER PRESSURE GRADIENT ARE STILL FAIRLY FAR TO THE NORTH...WITH WON`T ARRIVE UNTIL LATER THIS EVENING. FOR THE REMAINDER OF THE AFTERNOON INTO THE EVENING...EXPECTED ISOLATED TO SCATTERED STORMS TO CONTINUE OVER THE MOUNTAINS AND HIGH VALLEYS WITH MOST ACTIVITY ENDING BY SUNSET. OVER THE I-25 CORRIDOR AND ACROSS THE EASTERN PLAINS...COLD FRONT WILL CONTINUE TO SINK SOUTH THROUGH THE EVENING...WITH GUSTY (30-40KT) NORTH WINDS ARRIVING AROUND SUNSET AT KCOS...AND SHORTLY THERE-AFTER ALONG THE LOWER ARKANSAS VALLEY. WITH CONVERGENCE ALONG THE FRONT AND SLIGHTLY DEEPER MOISTURE PUSHING WESTWARD ONCE THE BOUNDARY PASSES...SUSPECT AT LEAST ISOLATED TSRA WILL BE POSSIBLE THROUGH 06Z-09Z ALONG AND EAST OF THE MOUNTAINS. PORTIONS OF THE PLAINS WILL LIKELY SEE SOME LOWER CLOUDS AND A FEW SPRINKLES/LIGHT SHOWERS TOWARD SUNRISE AS DEEPER MOISTURE CONTINUES TO PUSH WESTWARD BEHIND THE FRONT. ON TUESDAY...MUCH COOLER CONDITIONS OVER THE EASTERN MOUNTAINS AND PLAINS WITH HIGH TEMPS AROUND 20F LOWER THAN MON. MOUNTAINS AND HIGH VALLEYS WILL COOL SLIGHTLY WITH MORE MOISTURE...THOUGH TEMPERATURE FALLS WILL BE LESS THAN THE DRAMATIC COOLING OVER THE PLAINS. AIR MASS OVER THE MOUNTAINS AND ALONG THE I-25 CORRIDOR WILL BE CONSIDERABLY MOISTER ON TUES...WITH SCT TO NUMEROUS TSRA LIKELY DEVELOPING BY EARLY AFTERNOON. DESPITE LACK OF ANY OBVIOUS UPPER SUPPORT....SUSPECT MODELS...ESPECIALLY NAM ARE UNDER ESTIMATING AMOUNT OF INSTABILITY OVER AREA AND WILL GO WITH HIGHER POPS THAN MODEL OUTPUT SUGGESTS. WILL HAVE TO WATCH AREA BURN SCARS AS STORMS WILL BE RATHER SLOW MOVING AND COULD PRODUCE HEAVY RAIN. MAIN QUESTION FOR THE DAY IS HOW FAR EAST WILL STORMS MOVE ON TO THE PLAINS...AS AIR MASS MAY TAKE A LONG TIME TO DESTABILIZE EAST OF I- 25. WILL KEEP AT LEAST ISOLATED POPS OVER ALL THE EASTERN PLAINS...AS LIFTED INDICES WILL EVENTUALLY DROP BELOW ZERO WITH AT LEAST A FEW HUNDRED JOULES OF CAPE AVAILABLE BY LATE AFTERNOON. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 239 PM MDT MON JUL 7 2014 MODELS CONTINUE TO BE IN AGREEMENT THROUGH THE EXTENDED PERIOD WITH HIGH PRESSURE OVER THE WEST AND A TROUGH OVER THE EASTERN STATES. ACTIVE WEATHER WILL PERSIST THROUGH THE EXTENDED PERIOD WITH GENERALLY DIURNALLY DRIVEN THUNDERSTORMS. EXPECT ONGOING SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE MOUNTAINS TUESDAY EVENING...SPREADING EAST ACROSS THE PLAINS THROUGH THE OVERNIGHT HOURS. LOCALLY HEAVY RAINFALL IS POSSIBLE...ESPECIALLY OVER THE EASTERN MOUNTAINS TUESDAY EVENING. BY WEDNESDAY...HIGH PRESSURE OVER THE GREAT BASIN WILL BUILD EASTWARD INTO THE ROCKIES. LOW LEVEL FLOW IS FORECAST TO TURN MORE SOUTHWESTERLY. MODELS ARE STILL TRYING TO DEVELOP A DRYLINE TYPE FEATURE ACROSS THE FAR EASTERN PLAINS WEDNESDAY AFTERNOON. THE GFS CONTINUES TO BE THE FURTHEST EAST...WITH CONVECTION FIRING OFF ACROSS WESTERN KANSAS. THE NAM KEEP THE MOISTURE FURTHER WEST ACROSS EASTERN COLORADO...WITH WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY WEDNESDAY AFTERNOON. SHEAR IS WEAK WITH THE HIGH PRESSURE OVERHEAD...AND IF THE MOISTURE STAYS IN PLACE...ONE OR TWO STRONG STORMS ARE POSSIBLE OVER THE PLAINS WEDNESDAY AFTERNOON TO EVENING. IT WILL ALL DEPEND IF AND WHERE THE DRYLINE SETS UP. EXPECT THUNDERSTORMS TO TRACK EAST OVERNIGHT AND CLEAR THE PLAINS BY THURSDAY MORNING. THE HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS COLORADO ON THURSDAY AND PERSIST THROUGH EARLY NEXT WEEK. THE MOUNTAIN AREAS OF SOUTHERN COLORADO WILL SEE DAILY AFTERNOON AND EVENING THUNDERSTORMS. ELSEWHERE...PRECIPITATION WILL DEPEND ON INDIVIDUAL DISTURBANCES MOVING NORTH OUT OF THE DESERT SOUTHWEST. MODELS SEEM TO BE IN GOOD AGREEMENT WITH DECENT WAVE MOVING NORTH SATURDAY INTO SUNDAY. BOTH DAYS WILL LIKELY SEE THE BEST POTENTIAL IN THE EXTENDED PERIOD OF SEEING WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY. MOISTURE WILL BE ADEQUATE FOR LOCALLY HEAVY RAINFALL ACROSS THE MOUNTAINS...WHICH COULD PRODUCE FLASH FLOODING ON AREA BURN SCARS. MOZLEY && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 239 PM MDT MON JUL 7 2014 HIGH BASED THUNDERSTORMS WILL CONTINUE OVER THE MOUNTAINS AND ALONG THE I-25 CORRIDOR LATE THIS AFTERNOON INTO THE EVENING...WITH ERRATIC AND GUSTY OUT FLOW WINDS UP TO 40 KTS POSSIBLE. A FRONT WILL DROP THROUGH THE SOUTHEAST PLAINS THIS EVENING...AFFECTING KCOS AND KPUB BETWEEN 03Z AND 06Z. GUSTY NORTH WINDS TO 30 TO 40 KTS WILL BE POSSIBLE WITH FRONTAL PASSAGE. ISOLATED THUNDERSTORMS MAY DEVELOP ALONG THIS BOUNDARY AS IT ROLLS THROUGH...THOUGH CIGS WILL LIKELY REMAIN VFR. STRATUS WILL DEVELOP ACROSS PORTIONS OF THE SOUTHEAST PLAINS TOWARDS TUESDAY MORNING...WITH CIGS MOST LIKELY REMAINING IN THE VFR TO MVFR CATEGORY. KALS WILL REMAIN VFR THROUGH TONIGHT. ON TUESDAY...EXPECT NUMEROUS TSRA OVER THE MOUNTAINS AFTER 18Z...WITH MVFR TO IFR CIGS POSSIBLE. AT THE TAF SITES...EXPECT A CHANCE OF TSRA AFTER 19Z. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...PETERSEN LONG TERM...MOZLEY AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1003 PM EDT MON JUL 7 2014 .SYNOPSIS... VERY WARM/HOT AND HUMID WEATHER WILL PERSIST THROUGH MID WEEK. WHILE MUCH OF THE TIME WILL BE DRY...A FEW STRONG HIT AND MISS THUNDERSTORMS WILL BE POSSIBLE AT TIMES ESPECIALLY ACROSS THE INTERIOR. A FEW ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE DURING THURSDAY IF THE COLD FRONT MOVES SLOWER. DRY WEATHER WITH LOWER HUMIDITY WILL ARRIVE BY THE END OF THE WEEK INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 10 PM UPDATE... OVERALL TREND IN THE FORECAST REMAINS ON TRACK FOR TONIGHT. AN AREA OF SHOWERS AND THUNDERSTORMS OVER THE HILLSBOROUGH AND ESSEX COUNTIES WILL CONTINUE TO MOVE OFFSHORE OVER THE NEXT HOUR. OTHERWISE THE FOCUS THEN TURNS TO THE ISOLATED SHOWERS BLOSSOMING ACROSS THE BERKSHIRES AND IN THE MOHAWK VALLEY IN NY. BELIEVE THESE SHOWERS AND ISO THUNDER WILL CONTINUE TO DEVELOP AND MOVE INTO SOUTHERN NEW ENGLAND DURING THE OVERNIGHT HOURS...ESPECIALLY WITH SHOWALTERS STILL FORECASTED TO STAY BELOW 0 AND RAP GUIDANCE CONTINUES TO SHOW ELEVATED INSTABILITY LASTING THROUGH AT LEAST 6Z. THE POSSIBILITY FOR STRONG TO SEVERE THUNDERSTORMS ARE LOW BUT CANT RULE OUT A VERY GUST NEAR 40 MPH. AS THERE IS STILL ELEVATED INSTABILITY AND LLJ. THESE SHOWERS SHOULD DISSIPATE VERY LATE TONIGHT AS SHORTWAVE MOVES EAST OF THE REGION...ALLOWING US TO LOSE THE LIFT FOR THUNDERSTORM DEVELOPMENT. PREVIOUS DISCUSSION... SHORTWAVE COMBINING WITH MODEST INSTABILITY ALONG WITH 30 TO 40 KNOTS OF SHEAR HAS ALLOWED SCATTERED STRONG TO SEVERE THUNDERSTORMS TO WORK INTO SOUTHWEST NH/NORTHWEST LATE THIS AFTERNOON. GIVEN CAPES ON THE ORDER OF 1000 TO 1500 J/KG INTO THIS EVENING...FEEL THE THREAT FOR SCATTERED STRONG TO SEVERE THUNDERSTORMS MAY EXPAND TO AFFECT PORTIONS OF NORTHERN CT...WESTERN/NORTH CENTRAL MA AND INTO SOUTHERN NH INTO THE EVENING HOURS. THE PRIMARY THREAT WILL BE STRONG TO DAMAGING STRAIGHT LINE WIND GUSTS ALONG WITH TORRENTIAL RAINFALL. HAIL WILL BE A SECONDARY CONCERN IF ANY DISCRETE CORES CAN DEVELOP. THERE IS UNCERTAINTY IF THIS ACTIVITY WILL HOLD TOGETHER AS IT TRIES TO ENTER EASTERN MA/RHODE ISLAND. WE SHOULD SEE A WEAKENING TREND...BUT STILL AT LEAST SOME CONVECTIVE POTENTIAL GIVEN 30+ KNOTS OF SHEAR ALONG WITH SOME INSTABILITY. WILL HAVE TO MONITOR THIS CLOSELY THIS EVENING. SHOULD SEE THE ACTIVITY WIND DOWN NEAR OR SHORTLY AFTER MIDNIGHT AS THE SHORTWAVE DEPARTS. OTHERWISE...CAN/T RULE OUT A SPOT SHOWER OR THUNDERSTORM GIVEN LOW LEVEL JET AND LEFT OVER INSTABILITY...BUT THE VAST MAJORITY OF THE NIGHT SHOULD BE DRY. LOW TEMPS WILL ONLY FALL BACK TO THE LOWER 70S IN MOST LOCALES...WITH PERHAPS A FEW UPPER 60S IN NORTHWEST MA/SOUTHWEST NH. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... TUESDAY AND TUESDAY NIGHT... ANOTHER VERY WARM/HOT AND HUMID DAY ACROSS THE REGION. HIGHS SHOULD TOP OUT AROUND 90 TO THE LOWER 90S IN MANY LOCATIONS...ALTHOUGH A FEW DEGREES COOLER ON THE SOUTH COAST/CAPE ISLANDS WITH SOUTHWEST WINDS. IT WILL ONCE AGAIN BE BREEZY IN THE AFTERNOON WITH SOUTHWEST WIND GUSTS OF 20 TO 30 MPH. WHILE MUCH OF THE DAY WILL BE DRY...THE ATMOSPHERE WILL BECOME MODERATELY UNSTABLE DURING THE AFTERNOON. EXPECT 1000 TO 2000 J/KG OF CAPE TO DEVELOP ALONG WITH 30 TO 40 KNOTS OF SHEAR. THE MAIN UNCERTAINTY IS THAT WE DON/T HAVE AS STRONG A SHORTWAVE APPROACHING AS THE ONE THIS AFTERNOON/EVENING. HOWEVER...GIVEN VERY GOOD INSTABILITY/SHEAR WE PROBABLY WILL SEE ISOLATED TO SCATTERED THUNDERSTORMS DEVELOP DURING THE LATE AFTERNOON/EVENING HOURS. WHILE AREAL COVERAGE REMAINS UNCERTAIN AND COULD BE LIMITED...ANY STORM OR STORM/S THAT ARE ABLE TO DEVELOP IN THIS ENVIRONMENT COULD BECOME STRONG TO SEVERE. THE MAIN THREAT WOULD BE STRONG TO DAMAGING STRAIGHT LINE WIND GUSTS...BUT LARGE HAIL CAN/T BE RULED OUT WITH ANY DISCRETE CELLS. HEAVY RAINFALL AND DANGEROUS CLOUD TO GROUND LIGHTNING WILL BE THE MAIN THREATS WITH THIS ACTIVITY. BEST SHOT FOR A FEW STRONG TO SEVERE THUNDERSTORMS WILL BE NORTHWEST OF A BOSTON TO PROVIDENCE LINE...ALTHOUGH CAN/T REALLY RULE ONE OUT ANYWHERE. SHOULD SEE ACTIVITY WIND DOWN AFTER MIDNIGHT...BUT CAN/T RULE OUT A FEW SPOT SHOWERS/THUNDERSTORMS RIGHT THROUGH DAYBREAK WEDNESDAY GIVEN GOOD JET DYNAMICS/INSTABILITY. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HIGHLIGHTS... * VERY WARM/HOT AND HUMID ON WED * A FEW THUNDERSTORMS POSSIBLE WED INTO THU * DRIER AND LESS HUMID AIR RETURNS BY THE END OF THE WEEK OVERVIEW AND MODEL PREFERENCES... MEDIUM RANGE MODEL SUITE ARE IN GOOD AGREEMENT IN CONTINUING TO DIG A LONG WAVE UPPER TROUGH/CUTOFF LOW FROM HUDSON BAY THROUGH THE GREAT LAKES TO THE OHIO VALLEY WHILE RIDGING BUILDS ACROSS WESTERN CANADA INTO THE NORTHERN ROCKIES INTO THURSDAY. WITH THE TROUGH AXIS CUTTING THROUGH THE LAKES...WILL SEE SLOW PROGRESSION OF COLD FRONT TRYING TO SLICE THROUGH THE REGION. ONCE THIS TROUGH LIFTS NE LATER THU/THU NIGHT...CONDITIONS LOOK TO IMPROVE WITH DRIER AIR MOVING IN. TIMING OF NEXT SYSTEM WORKING ACROSS THE NORTHERN TIER STATES IS IN QUESTION WITH LACK OF MODEL CONTINUITY...THOUGH LOOKS LIKE ANOTHER H5 CUTOFF LOW DIGS OUT OF NORTHERN CANADA ACROSS HUDSON BAY INTO EARLY NEXT WEEK...SO ANOTHER TROUGH MAY START TO DIG SERD. MODELS ARE DIVIDED ON HOW FAR THIS WILL DIG S AND HOW SURFACE SYSTEMS RIDING ALONG IN THIS FLOW WILL MOVE...SO LOWER CONFIDENCE IN FORECAST BEYOND SATURDAY. WITH THE GOOD AGREEMENT WITH THE MODELS EARLY IN THIS CYCLE...USED A BLEND OF AVAILABLE GUIDANCE THEN LEANED TOWARD THE ENSEMBLES BEYOND FRIDAY WITH THE TIMING ISSUES NOTED. DETAILS... WEDNESDAY/WEDNESDAY NIGHT... WITH THE COLD FRONT RUNNING NEARLY PARALLEL TO THE UPPER LEVEL TROUGH...WILL BE SLOW TO EXIT THE REGION. STILL QUITE A BIT OF INSTABILITY ACROSS THE REGION WITH CAPES IN THE 500-1000 J/KG RANGE AND LIFTED INDICES BELOW ZERO. SO...KEPT CHANCE OF SHOWERS/TSTMS GOING IN THE FORECAST. ALSO...PWATS ARE 1.8 TO 1.9 INCHES...SO WILL SEE HEAVY RAINERS WITH ANY TSTMS. KEPT HEAVY RAINFALL WORDING GOING IN THE FORECAST INTO EARLY WED NIGHT. WILL ALSO NEED TO MONITOR WIND SHEAR ON ORDER OF AROUND 40 KT WHICH COULD HELP VENT ANY CONVECTION ALONG WITH THE CAPES AND LI/S. EXPECTING WARM AND HUMID CONDITIONS WITH HIGHS IN THE 80S...HIGHEST ACROSS E MA/RI/N CT. FOR NOW...LOOKS LIKE THE FRONT WILL CLEAR THE COAST OVERNIGHT WED BUT MAY HUG THE COAST INTO THU MORNING. BRINGING BACK EDGE OF PRECIP SLOWLY SEWD AND HAVE KEPT MENTION OF THUNDER IN GENERALLY ACROSS AREAS S OF THE MASS PIKE. THURSDAY... HAVE KEPT SLIGHT CHANCE MENTION OF SHOWERS/TSTMS...MAINLY ACROSS E MA/RI/NE CT THU MORNING...THEN SHOULD SHIFT OFFSHORE DURING THE AFTERNOON. THIS WILL BE DEPENDENT UPON TIMING OF THE UPPER TROUGH TO THE N AND W. MODELS DO SHOW PRETTY GOOD AGREEMENT THOUGH. WILL STILL NEED TO MONITOR THE TIMING AND WHETHER MORE INSTABILITY THAN CURRENTLY INDICATED WILL HANG BACK. DEWPTS IN THE LOWER-MID 60S DO HANG BACK ACROSS THE AREA...SO MAY HAVE SOME PROBLEMS EARLY. FRIDAY AND SATURDAY... HIGH PRES WILL PUSH E FROM THE GREAT LAKES...BRINGING COOLER AND DRIER CONDITIONS. SEA BREEZES WILL BE LIKELY BOTH DAYS WITH THE LIGHT WIND FLOW IN PLACE THANKS TO THE HIGH. DAYTIME HIGHS WILL BE IN THE LOWER 80S...CLOSE TO SEASONAL NORMALS. CLOUDS LOOK TO INCREASE FROM THE W SATURDAY NIGHT. SUNDAY AND MONDAY... AS LONG WAVE TROUGHING LOOKS TO RETURN TO THE W OF THE REGION... MAY SEE ANOTHER FRONT BEGIN TO APPROACH. HOWEVER...DUE TO TIMING ISSUES...NOT A LOT OF CONFIDENCE BUT DOES LOOK LIKE ANOTHER ROUND OF SCT SHOWERS/TSTMS RETURN. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY NIGHT/... TONIGHT...MODERATE CONFIDENCE. SCT SHOWERS/THUNDERSTORMS ARE EXPECTED TO MOVE INTO INTERIOR SOUTHERN NEW ENGLAND THROUGH ABOUT MIDNIGHT. A FEW OF THE STORMS MAY RESULT IN STRONG WIND GUSTS AND BRIEF TORRENTIAL RAIN. THE ACTIVITY WILL BE HIT AND MISS...BUT WILL RESULT IN LOCALIZED MVFR-IFR CONDITIONS. SOUTHWEST WIND GUSTS OF 25 TO 30 KNOTS SHOULD DIMINISH BY 03Z. OTHERWISE...VFR CONDITIONS DOMINATE THROUGH TONIGHT OTHER THAN SOME LOCALIZED PATCHY GROUND FOG LATE. LOW PROBABILITY THAT LOW CLOUDS/FOG DEVELOP ACROSS SOUTHEAST NEW ENGLAND BUT DIDN/T HAVE ENOUGH CONFIDENCE TO INSERT INTO THE TAF. LATER SHIFTS WILL HAVE TO MONITOR. TUESDAY AND TUESDAY NIGHT...MODERATE CONFIDENCE. VFR CONDITIONS WILL DOMINATE...BUT PERHAPS A BETTER CHANCE OF LOW CLOUDS AND FOG DEVELOPING ALONG THE SOUTHEAST NEW ENGLAND COAST TUE NIGHT. IN ADDITION...A FEW AFTERNOON AND EVENING STRONG THUNDERSTORMS ARE POSSIBLE WITH THE BEST SHOT NORTHWEST OF A BOS TO PVD LINE. KBOS TAF...MODERATE CONFIDENCE IN TAF. LOW PROBABILITY FOR A THUNDERSTORM IN THE VICINITY BETWEEN 00Z AND 04Z. KBDL TAF...MODERATE CONFIDENCE IN TAF. LOW TO MODERATE PROBABILITY FOR A FEW STRONG THUNDERSTORMS IN THE VICINITY BETWEEN 21Z AND 03Z. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WEDNESDAY...MODERATE CONFIDENCE. MAINLY VFR AWAY FROM THE COAST. AREAS OF IFR CIGS/VSBYS ACROSS COASTAL AREAS IN LOW CLOUDS/FOG WHICH SHOULD IMPROVE BY AROUND MID MORNING...BUT WILL REDEVELOP AFTER MIDNIGHT WED NIGHT. WILL SEE LOCAL BRIEF MVFR-IFR CIGS/VSBYS IN SCT SHOWERS/TSTMS. THURSDAY...MODERATE CONFIDENCE. SHOULD BE MAINLY VFR. WIDELY SCT SHOWERS LINGER WITH LOCAL MVFR VSBYS. ISOLD THUNDER POSSIBLE ALONG S COAST. FRIDAY...HIGH CONFIDENCE. VFR CONDITIONS. SATURDAY...MODERATE CONFIDENCE. VFR INTO EARLY SATURDAY NIGHT. MAY SEE MVFR CIGS/VSBYS AFTER MIDNIGHT IN SCT SHOWERS/ISOLD TSTMS ACROSS WESTERN AREAS AS ANOTHER SYSTEM APPROACHES. LOWER CONFIDENCE DUE TO TIMING ISSUES. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY NIGHT/...HIGH CONFIDENCE. 8 PM UPDATE...HAVE ALLOWED NEAR SHORE SMALL CRAFTS TO EXPIRE...BUT DID KEEP THE SOUTHERN BAYS AND SOUNDS TO REMAIN UP UNTIL MIDNIGHT. PERSISTENT SOUTHWEST FLOW WILL CONTINUE RIGHT THROUGH TUESDAY NIGHT AHEAD OF A SLOW MOVING COLD FRONT. WINDS MAY BE A TOUCH LESS GUSTY ON TUESDAY...BUT STILL THE RISK FOR 25 KNOT WIND GUSTS SO MORE NEAR SHORE SCA HEADLINES MAY BE NEEDED. AS FOR THE OUTER WATERS...WILL CONTINUE TO NEED SCA HEADLINES WITH LONG SOUTHWEST FETCH RESULTING IN 4 TO 7 FOOT SEAS. OTHERWISE...MAY SEE AREAS OF FOG DEVELOP MAINLY TUE NIGHT WHICH COULD BE LOCALLY DENSE ACROSS THE SOUTHERN WATERS. IN ADDITION...LOW TO MODERATE PROBABILITY FOR A FEW STRONG THUNDERSTORMS TO MOVE ACROSS THE NEAR SHORE WATERS THIS EVENING AND AGAIN LATE TUE. OUTLOOK...WEDNESDAY THROUGH SATURDAY. WEDNESDAY...MODERATE CONFIDENCE. S-SW WINDS CONTINUE AT 10-15 KT. A FEW GUSTS TO 20 KT POSSIBLE THROUGH THE DAYLIGHT HOURS. S SWELLS WILL CONTINUE AT 5-7 FT ON THE OUTER WATERS. REDUCED VSBYS IN FOG WILL CONTINUE. SCT SHOWERS/TSTMS WITH HEAVY RAINFALL THROUGH WED EVENING. THURSDAY...MODERATE CONFIDENCE. S-SW WINDS BELOW 15 KT DURING THE DAY WILL SLOWLY SHIFT TO W-NW THURSDAY NIGHT. MAY SEE 5 FOOT SEAS ACROSS THE SOUTHERN OUTER WATERS EARLY...THEN SHOULD SUBSIDE. FRIDAY-SATURDAY...HIGH CONFIDENCE. WINDS AND SEAS BELOW SMALL CRAFT CRITERIA. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ231>234. SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR ANZ235-237- 254>256. SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ250. && $$ SYNOPSIS...FRANK/EVT NEAR TERM...FRANK/DUNTEN SHORT TERM...FRANK LONG TERM...EVT AVIATION...FRANK/EVT MARINE...FRANK/EVT
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1006 PM CDT MON JUL 7 2014 .DISCUSSION... 825 PM CDT A COLD FRONTAL BOUNDARY CONTINUES TO MOVE SOUTHEAST ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL IOWA WHILE A STATIONARY BOUNDARY IS STRETCHED FROM WEST TO EAST ACROSS THE FAR SOUTHERN CWA. WATER VAPOR SHOWS AN UPPER TROUGH SWINGING SOUTHEASTWARD INTO MINNESOTA WITH SEVERAL EMBEDDED WAVES HELPING TO KICK OFF CONVECTION...WITH ONE COMPLEX OVER WEST CENTRAL MINNESOTA AND ANOTHER ALONG THE IA/MO BORDER. THE CWA IS EXPECTED TO REMAIN BETWEEN THE TWO CURRENT AREAS OF CONVECTION BUT ADDITIONAL DEVELOPMENT IS EXPECTED JUST WEST OR OVER THE AREA LATER TONIGHT AS THE FRONT AND AN UPPER WAVE PASS. LATEST GUIDANCE SUGGESTS THAT THE MID LEVEL WAVE WILL AMPLIFY BRINGING AN ATTENDANT SPEED MAX ACROSS THE AREA INTO THE OVERNIGHT HOURS. ACTIVITY ALONG THE FRONT NEAR THE IA/MN BORDER HAS BEEN FESTERING BUT RAP ANALYSIS INDICATES THAT THERE IS STRONGER AXIS OF INSTABILITY ACROSS NORTHEAST IA THAT IS UNCAPPED SO SOME ENHANCEMENT IS POSSIBLE GOING FORWARD. EVENING DVN SOUNDING SHOWS A CAP IN PLACE WITH LOCAL AIRCRAFT SOUNDINGS SHOWING A MINIMAL CAP. WOULD THINK THIS CAP WOULD ERODE WITH THE INCREASE IN MID/UPPER ASCENT INTO THE OVERNIGHT. WITH MOISTURE FLUX AND PRIMARY LOW LEVEL JET WELL SOUTH OF THE AREA HIGHLY ORGANIZED CONVECTION IS UNLIKELY ACROSS THE AREA BUT DO SEE SOME OPPORTUNITY FOR SOME LOOSELY ORGANIZED ACTIVITY OVERNIGHT...WITH EXPANSION LATE THIS EVENING BUT PROBABLY STARTING TO WANE DURING THE LATE OVERNIGHT HOURS. WILL MAINTAIN THE LIKELY POPS AFTER 06Z...WITH LOWER CHANCES JUST BEFORE 06Z IN THE NORTHWEST BASED ON LATEST TRENDS. SOME GUIDANCE CONTINUES TO SUPPORT AN NORTHWARD EXPANSION OF THE MAIN AREA OF CONVECTION TO THE SOUTH OVERNIGHT IN RESPONSE TO THE INCREASE IN THE MAIN LOW LEVEL JET SO BETTER ORGANIZED ACTIVITY IS POSSIBLE IN THE FAR SOUTH SO WILL CONTINUE TO THE HIGHEST QPF IN THAT AREA. HEAVY DOWNPOURS ARE STILL THE PRIMARY THREAT WITH SOME STRONGER WIND GUSTS POSSIBLE AS WELL...ESPECIALLY ACROSS WESTERN AND SOUTHERN AREAS. MDB //PREV DISCUSSION... 142 PM CDT TONIGHT THROUGH TUESDAY... THIS AFTERNOON SKIES HAVE BECOME P-CLOUDY ACROSS THE REGION...WITH SLIGHTLY MORE AGITATED CU FIELD OVER EASTERN COOK COUNTY STRETCHING EAST INTO NORTHWEST IN...WHERE A LAKE BREEZE HAS DEVELOPED AND CONTINUES TO DRIFT INLAND. A FEW SHOWERS/THUNDERSTORMS WERE ALSO ABLE TO DEVELOP ALONG THE LAKE BREEZE IN NORTHWEST INDIANA. GREATER INSTABILITY WAS FOCUSED FURTHER SOUTH ASSOCIATED WITH THE FRONTAL BOUNDARY THAT BROUGHT PRECIP EARLY THIS MORNING TO NORTHERN IL/NORTHWEST IN. THIS AFTN THE FRONTAL BOUNDARY WAS ORIENTED FROM NORTH CENTRAL IN STRETCHING SOUTHWEST THROUGH CENTRAL IL THEN BENDING WEST/NORTHWEST INTO EASTERN NEBRASKA. DEW POINTS BEHIND THIS FEATURE IN NORTHERN IL HAVE BEEN ABLE TO FALL OFF INTO THE LOW/MID 60S...MEANWHILE ALONG AND SOUTH OF THE BOUNDARY ABUNDANT MOISTURE REMAINS WITH DEW PTS STILL IN THE LOW/MID 70S. AFTN TEMPS WILL CONTINUE TO WARM INTO THE MID/UPR 80S. THEN THE FOCUS OVERNIGHT WILL TURN TOWARDS THE WAVE CURRENTLY LOCATED OVER NEBRASKA/SOUTH DAKOTA/SOUTHWEST MINNESOTA. GUIDANCE HAS BEEN STEADILY CONSOLIDATING TOWARDS SLIGHTLY MORE UNIFORM SOLUTION...DEVELOPING A COMPLEX AND BRINGING THE ACTIVITY EAST THEN TURNING SOUTHEAST INTO SOUTHEAST IOWA/NORTHEAST MO...THEN CLIPPING THE SOUTHERN CWFA ARND MIDNIGHT THRU DAYBREAK TUE. THE PLACEMENT OF THE LLVL JET OVERNIGHT WOULD SUGGEST THAT SOME OF THE MOISTURE COULD STILL LIFT NORTH...REACHING THE NORTHERN CWFA ARND 6Z TUE AND CONTINUE THRU ARND DAYBREAK TUE BEFORE DRYING OUT FROM WEST TO EAST TUE MORNING. MID/UPR 60S DEW-PTS WILL LIKELY ADVECT BACK NORTH...WITH THE POTENTIAL FOR SOME OF THE STORMS EASILY PRODUCING BRIEF HEAVY DOWNPOURS. IN REGARDS TO ANY STORMS REACHING SEVERE CRITERIA OVERNIGHT...THIS STILL FAVORS OUR FAR WEST/SOUTHWEST. ALTHOUGH CONFIDENCE HAS DIMINISHED MARGINALLY...GIVEN THE BETTER FOCUS APPEARING TO BE FURTHER SOUTHWEST OF THE AREA. AT THIS TIME IT APPEARS A COMPLEX OF THUNDERSTORMS WILL BE ARRIVING IN THE WEST LATE TONIGHT...THEN BEGINNING TO DECAY DURING THE MORNING HOURS FOCUSED SOUTH OF I-80. THE LOBE OF VORTICITY PROGGED BY MOST GUIDANCE HAS BEEN FOCUSED ALONG THE FRONTAL BOUNDARY...WHICH IS WHY THE CONFIDENCE IN STRONGEST ACTIVITY BEING FURTHER SOUTH REMAINS. OVERNIGHT LOWS WILL REMAIN MILD IN THE MID/UPR 60S...POSSIBLY ARND 70 CLOSER TO DOWNTOWN CHICAGO. MID-LVL TROUGH AXIS STEADILY PIVOTS SOUTHEAST FROM THE UPPER MIDWEST...ARRIVING MID-MORNING TUE. THIS WILL PUSH A COLD FRONT THRU THE FORECAST AREA...WITH FLOW TURNING WEST/NORTHWEST. 850MB THERMAL RIDGE RELAXES WITH TEMPS ARND 12-14 DEG C ARRIVING MIDDAY WITH AFTN HIGHS GENERALLY IN THE UPR 70S TO ARND 80. WITH THE COOLER AIR ALOFT...AND MID-LVL LAPSE RATES STEEPENING...SOME ISOLATED DIURNALLY DRIVEN LOW TOPPED CONVECTION IS POSSIBLE MAINLY ALONG AND EAST OF ROCKFORD TO KANKAKEE. SFC RIDGE WILL SLOWLY BUILD IN TUE NGT...WITH AN ADDTL PUSH OF DRIER AIR AND THINNING CLOUD COVER. TEMPS SHUD BE ABLE TO COOL FURTHER INTO THE 50S TO NEAR 60. CONFIDENCE...HIGH. WEDNESDAY THROUGH THURSDAY... 500MB TROUGH WILL BE OVERHEAD BY EARLY WED...AND LOOKS TO REMAIN IN PLACE THRU THUR BEFORE SLOWLY EJECTING TO THE EAST LATE THUR. SFC RIDGING CONTINUES TO BE PROGGED TO BUILD IN FROM THE WEST...AND BRING MUCH DRIER AND COOLER AIR BACK TO THE FORECAST AREA FOR MID-WEEK. TEMPS ALOFT WILL HOVER ARND 10-13 DEG C...WITH HIGHS GENERALLY IN THE UPR 70S EACH DAY. OVERNIGHT LOWS WILL BE PLEASANT...IN THE UPR 50S TO LOW 60S. FRIDAY THROUGH THE WEEKEND... MINIMAL CHANGES TO THE GOING FORECAST...WITH THE TROUGH EXITING TO THE EAST AND MID-LVL FLOW BECOMING FLAT. AS THE SFC RIDGE PUSHES EAST...LLVL FLOW TURNS SOUTHERLY AND WARM/MOIST AIR BEGINS TO ADVECT BACK ACROSS THE REGION. A WEAK WAVE PUSHES OVERHEAD FRI...WITH A QUASI-STATIONARY BOUNDARY SETTING UP FOR THE WEEKEND AND ALLOWING A SEMI ACTIVE PATTERN. TEMPS WILL RETURN TO THE LOW/MID 80S. BEYOND THE CURRENT EXTENDED PERIODS...ENSEMBLES ARE ADVERTISING A HIGH CONFIDENCE RIDGE DEVELOPING ACROSS WESTERN CANADA AND DIGGING A TROUGH INTO THE GREAT LAKES/HUDSON BAY AREA EARLY NEXT WEEK. IF THIS SCENARIO VERIFIES...TEMPS WILL COOL BACK INTO THE UPR 70S TO KICK-OFF NEXT WEEK. CONFIDENCE...HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * POTENTIAL FOR CONVECTION OVERNIGHT. * LAKE BREEZE AFFECTING EITHER TERMINAL TUESDAY AFTERNOON. * POSSIBLE SHRAS NEAR LAKESHORE TUESDAY AFTERNOON. 2% //DISCUSSION...UPDATED 03Z... TREND FROM PREVIOUS PACKAGE STILL LOOKS ON TRACK. AREA REMAINS BETWEEN TWO CONVECTIVE SYSTEMS...ONE ALONG A COLD FRONT ACROSS WI AND FAR NE IA AND THE OTHER PUSHING ESE ACROSS MO. THERE REMAINS SOME QUESTION AS TO WHETHER ANY SIGNIFICANT CONVECTION WILL AFFECT THE TERMINALS TONIGHT. GUIDANCE IS PROVIDING CONFLICTING SCENARIOS FROM NO PRECIP TO WIDESPREAD COVERAGE. WILL HOLD OFF ON MAKING CHANGES TO THE VCTS GROUP UNTIL CONVECTIVE TRENDS BECOME MORE CLEAR. SOME LIGHT SHRAS HAVE DVLPD ACROSS NW IL RECENTLY AND WILL REMAIN NORTH OF I88 OVER THE NEXT HOUR OR TWO. INTRODUCED AN HOUR OF VFR SHRA AT RFD WITH VCSH FOR THE OTHER METRO TERMINALS. WINDS HAVE ALSO TURNED TO THE SOUTH ACROSS NW IL SO HAVE A FEW HOURS OF SRLY WINDS BETWEEN THE VC GROUPS. PREVIOUS DISCUSSION FROM 00Z LAKE BREEZE RETREATING TOWARDS THE LAKE LATE THIS AFTN...SO IT IS NO LONGER A CONCERN. ATTENTION THEN TURNS TOWARDS CONVECTION ACROSS MN/WI ASSOC WITH A COLD FRONT AND AN UPPER LEVEL DISTURBANCE. THIS ACTIVITY IS FCST TO WORK ESE THRU THE EVENING AND OVERNIGHT REACHING THE AREA AFTER MIDNIGHT. FEEL PRETTY SURE THAT CONVECTION WILL PASS THRU THE AREA...BUT NOT SO SURE ON THE COVERAGE ONCE IT GETS HERE...HENCE MAINTAINING THE ONGOING VCTS GROUP LATE TONIGHT INTO EARLY TUESDAY MORNING WITH THE ACTIVITY CLEARING EAST BY MID MORNING. LOOKS LIKE THE LAKE BREEZE WILL ONCE AGAIN DEVELOP BY TUESDAY AFTN. BIG QUESTION IS WHETHER IT WILL IMPACT EITHER ORD OR MDW. THINK A SIMILAR SCENARIO WILL UNFOLD AS WHAT HAPPENED TODAY WHERE IT WILL HAVE TROUBLE MAKING IT TO EITHER TERMINAL GIVEN THE DECENT NW FLOW NEAR 10KTS. OBVIOUSLY MDW HAS THE BIGGEST CHANCE OF BEING AFFECTED. THERE IS ALSO A CHANCE THAT THERE COULD BE A FEW LIGHT SHRAS OR SPRINKLES THAT DVLP NEAR THE LAKESHORE/LAKE BREEZE TUESDAY AFTN. THINK THE UNCERTAINTIES IN PLACEMENT...COVERAGE AND THE TIMING SO LATE IN THE TAF PERIOD PRECLUDE INCLUDING A MENTION IN THE TAFS ATTM. WILL ALLOW LATER SHIFTS TO RE-EVALUATE THE THREAT. WOULD EXPECT IF THEY DID DVLP AND AFFECT A TERMINAL THAT CONDITIONS WOULD REMAIN VFR. 2% //ORD AND MDW CONFIDENCE...UPDATED 03Z... * MEDIUM-HIGH CONFIDENCE THAT CONVECTION WILL MOVE INTO THE AREA...LOW-MEDIUM THAT IT WILL IMPACT EITHER TERMINAL. * HIGH CONFIDENCE THAT A LAKE BREEZE WILL DEVLOP BY TUESDAY AFTERNOON...MEDIUM CONFIDENCE THAT IT WILL NOT AFFECT ORD...LOW CONFIDENCE THAT IT WILL NOT AFFECT MDW. * LOW CONFIDENCE THAT SHRAS WILL DEVELOP NEAR THE LAKESHORE TUESDAY AFTERNOON...AND IF THEY DO WHETHER THEY WILL AFFECT EITHER TERMINAL. 2% //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY AND THURSDAY...VFR FRIDAY THROUGH SUNDAY...GENERALLY VFR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE PERIOD. 2% && .MARINE... 152 PM CDT NO MAJOR CONCERNS THROUGH THE PERIOD FOR THE MARINE FORECAST...WITH FOCUS MAINLY ON A SERIES OF RELATIVELY WEAK COLD FRONTAL PASSAGES THROUGH TUESDAY BEFORE HIGH PRESSURE SPREADS ACROSS THE WESTERN LAKES LATER WEDNESDAY NIGHT AND THURSDAY. IN THE NEAR TERM...LOW PRESSURE WAS PASSING NORTH OF THE LAKES FROM NORTHEASTERN ONTARIO INTO QUEBEC EARLY THIS AFTERNOON WITH A COLD FRONT TRAILING SOUTHWEST INTO FAR NORTHWEST INDIANA JUST SOUTH OF THE LAKE MICHIGAN SHORE AT 18Z. WINDS HAD BECOME VARIABLE ON THE SOUTHERN PORTION OF THE LAKE IN THE BAGGY GRADIENT BEHIND THE COLD FRONT...ALLOWING WEAK LAKE BREEZE DEVELOPMENT AROUND THE SOUTH END OF THE LAKE. FARTHER NORTH...WINDS HAVE BACKED TO THE SOUTHWEST WITH THE GRADIENT TIGHTENING A BIT IN ADVANCE OF THE NEXT MID-LEVEL DISTURBANCE TRACKING ACROSS THE UPPER MIDWEST. THIS MID-LEVEL WAVE WILL MOVE ACROSS THE REGION LATER TONIGHT...ALLOWING ANOTHER WEAK COLD FRONT TO SAG ACROSS THE NORTHERN PART OF THE LAKE LATE TONIGHT. YET ANOTHER MORE AMPLIFIED DISTURBANCE WILL SPREAD OVER THE WESTERN LAKES TUESDAY...WITH A DEVELOPING WEAK AREA OF SURFACE LOW PRESSURE MOVING EAST OF THE LAKE BY THE AFTERNOON AND NORTHWEST WINDS DEVELOPING. SPEEDS LOOK TO REMAIN FAIRLY MODEST...GENERALLY IN THE 15-20 KT RANGE DURING HIGHEST PERIODS. A THIRD DISTURBANCE SWINGS ACROSS THE NORTHERN LAKES...WI/MI LATE TUESDAY NIGHT...RESULTING IN SOME BACKING OF THE WINDS ON NORTHERN LAKE MICHIGAN...BUT THESE TOO TURN NORTHWEST AGAIN BY WEDNESDAY AFTERNOON. HIGH PRESSURE THEN PRESSES EASTWARD INTO THE MISSISSIPPI RIVER VALLEY BY WEDNESDAY EVENING...AND ACROSS LAKE MICHIGAN WEDNESDAY NIGHT AND THURSDAY. WINDS WILL THEN BECOME SOUTH-SOUTHEAST THURSDAY NIGHT AS THE RIDGE MOVES OFF TO THE EAST. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ 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
828 PM CDT MON JUL 7 2014 .DISCUSSION... 825 PM CDT A COLD FRONTAL BOUNDARY CONTINUES TO MOVE SOUTHEAST ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL IOWA WHILE A STATIONARY BOUNDARY IS STRETCHED FROM WEST TO EAST ACROSS THE FAR SOUTHERN CWA. WATER VAPOR SHOWS AN UPPER TROUGH SWINGING SOUTHEASTWARD INTO MINNESOTA WITH SEVERAL EMBEDDED WAVES HELPING TO KICK OFF CONVECTION...WITH ONE COMPLEX OVER WEST CENTRAL MINNESOTA AND ANOTHER ALONG THE IA/MO BORDER. THE CWA IS EXPECTED TO REMAIN BETWEEN THE TWO CURRENT AREAS OF CONVECTION BUT ADDITIONAL DEVELOPMENT IS EXPECTED JUST WEST OR OVER THE AREA LATER TONIGHT AS THE FRONT AND AN UPPER WAVE PASS. LATEST GUIDANCE SUGGESTS THAT THE MID LEVEL WAVE WILL AMPLIFY BRINGING AN ATTENDANT SPEED MAX ACROSS THE AREA INTO THE OVERNIGHT HOURS. ACTIVITY ALONG THE FRONT NEAR THE IA/MN BORDER HAS BEEN FESTERING BUT RAP ANALYSIS INDICATES THAT THERE IS STRONGER AXIS OF INSTABILITY ACROSS NORTHEAST IA THAT IS UNCAPPED SO SOME ENHANCEMENT IS POSSIBLE GOING FORWARD. EVENING DVN SOUNDING SHOWS A CAP IN PLACE WITH LOCAL AIRCRAFT SOUNDINGS SHOWING A MINIMAL CAP. WOULD THINK THIS CAP WOULD ERODE WITH THE INCREASE IN MID/UPPER ASCENT INTO THE OVERNIGHT. WITH MOISTURE FLUX AND PRIMARY LOW LEVEL JET WELL SOUTH OF THE AREA HIGHLY ORGANIZED CONVECTION IS UNLIKELY ACROSS THE AREA BUT DO SEE SOME OPPORTUNITY FOR SOME LOOSELY ORGANIZED ACTIVITY OVERNIGHT...WITH EXPANSION LATE THIS EVENING BUT PROBABLY STARTING TO WANE DURING THE LATE OVERNIGHT HOURS. WILL MAINTAIN THE LIKELY POPS AFTER 06Z...WITH LOWER CHANCES JUST BEFORE 06Z IN THE NORTHWEST BASED ON LATEST TRENDS. SOME GUIDANCE CONTINUES TO SUPPORT AN NORTHWARD EXPANSION OF THE MAIN AREA OF CONVECTION TO THE SOUTH OVERNIGHT IN RESPONSE TO THE INCREASE IN THE MAIN LOW LEVEL JET SO BETTER ORGANIZED ACTIVITY IS POSSIBLE IN THE FAR SOUTH SO WILL CONTINUE TO THE HIGHEST QPF IN THAT AREA. HEAVY DOWNPOURS ARE STILL THE PRIMARY THREAT WITH SOME STRONGER WIND GUSTS POSSIBLE AS WELL...ESPECIALLY ACROSS WESTERN AND SOUTHERN AREAS. MDB && .PREV DISCUSSION... 142 PM CDT TONIGHT THROUGH TUESDAY... THIS AFTERNOON SKIES HAVE BECOME P-CLOUDY ACROSS THE REGION...WITH SLIGHTLY MORE AGITATED CU FIELD OVER EASTERN COOK COUNTY STRETCHING EAST INTO NORTHWEST IN...WHERE A LAKE BREEZE HAS DEVELOPED AND CONTINUES TO DRIFT INLAND. A FEW SHOWERS/THUNDERSTORMS WERE ALSO ABLE TO DEVELOP ALONG THE LAKE BREEZE IN NORTHWEST INDIANA. GREATER INSTABILITY WAS FOCUSED FURTHER SOUTH ASSOCIATED WITH THE FRONTAL BOUNDARY THAT BROUGHT PRECIP EARLY THIS MORNING TO NORTHERN IL/NORTHWEST IN. THIS AFTN THE FRONTAL BOUNDARY WAS ORIENTED FROM NORTH CENTRAL IN STRETCHING SOUTHWEST THROUGH CENTRAL IL THEN BENDING WEST/NORTHWEST INTO EASTERN NEBRASKA. DEW POINTS BEHIND THIS FEATURE IN NORTHERN IL HAVE BEEN ABLE TO FALL OFF INTO THE LOW/MID 60S...MEANWHILE ALONG AND SOUTH OF THE BOUNDARY ABUNDANT MOISTURE REMAINS WITH DEW PTS STILL IN THE LOW/MID 70S. AFTN TEMPS WILL CONTINUE TO WARM INTO THE MID/UPR 80S. THEN THE FOCUS OVERNIGHT WILL TURN TOWARDS THE WAVE CURRENTLY LOCATED OVER NEBRASKA/SOUTH DAKOTA/SOUTHWEST MINNESOTA. GUIDANCE HAS BEEN STEADILY CONSOLIDATING TOWARDS SLIGHTLY MORE UNIFORM SOLUTION...DEVELOPING A COMPLEX AND BRINGING THE ACTIVITY EAST THEN TURNING SOUTHEAST INTO SOUTHEAST IOWA/NORTHEAST MO...THEN CLIPPING THE SOUTHERN CWFA ARND MIDNIGHT THRU DAYBREAK TUE. THE PLACEMENT OF THE LLVL JET OVERNIGHT WOULD SUGGEST THAT SOME OF THE MOISTURE COULD STILL LIFT NORTH...REACHING THE NORTHERN CWFA ARND 6Z TUE AND CONTINUE THRU ARND DAYBREAK TUE BEFORE DRYING OUT FROM WEST TO EAST TUE MORNING. MID/UPR 60S DEW-PTS WILL LIKELY ADVECT BACK NORTH...WITH THE POTENTIAL FOR SOME OF THE STORMS EASILY PRODUCING BRIEF HEAVY DOWNPOURS. IN REGARDS TO ANY STORMS REACHING SEVERE CRITERIA OVERNIGHT...THIS STILL FAVORS OUR FAR WEST/SOUTHWEST. ALTHOUGH CONFIDENCE HAS DIMINISHED MARGINALLY...GIVEN THE BETTER FOCUS APPEARING TO BE FURTHER SOUTHWEST OF THE AREA. AT THIS TIME IT APPEARS A COMPLEX OF THUNDERSTORMS WILL BE ARRIVING IN THE WEST LATE TONIGHT...THEN BEGINNING TO DECAY DURING THE MORNING HOURS FOCUSED SOUTH OF I-80. THE LOBE OF VORTICITY PROGGED BY MOST GUIDANCE HAS BEEN FOCUSED ALONG THE FRONTAL BOUNDARY...WHICH IS WHY THE CONFIDENCE IN STRONGEST ACTIVITY BEING FURTHER SOUTH REMAINS. OVERNIGHT LOWS WILL REMAIN MILD IN THE MID/UPR 60S...POSSIBLY ARND 70 CLOSER TO DOWNTOWN CHICAGO. MID-LVL TROUGH AXIS STEADILY PIVOTS SOUTHEAST FROM THE UPPER MIDWEST...ARRIVING MID-MORNING TUE. THIS WILL PUSH A COLD FRONT THRU THE FORECAST AREA...WITH FLOW TURNING WEST/NORTHWEST. 850MB THERMAL RIDGE RELAXES WITH TEMPS ARND 12-14 DEG C ARRIVING MIDDAY WITH AFTN HIGHS GENERALLY IN THE UPR 70S TO ARND 80. WITH THE COOLER AIR ALOFT...AND MID-LVL LAPSE RATES STEEPENING...SOME ISOLATED DIURNALLY DRIVEN LOW TOPPED CONVECTION IS POSSIBLE MAINLY ALONG AND EAST OF ROCKFORD TO KANKAKEE. SFC RIDGE WILL SLOWLY BUILD IN TUE NGT...WITH AN ADDTL PUSH OF DRIER AIR AND THINNING CLOUD COVER. TEMPS SHUD BE ABLE TO COOL FURTHER INTO THE 50S TO NEAR 60. CONFIDENCE...HIGH. WEDNESDAY THROUGH THURSDAY... 500MB TROUGH WILL BE OVERHEAD BY EARLY WED...AND LOOKS TO REMAIN IN PLACE THRU THUR BEFORE SLOWLY EJECTING TO THE EAST LATE THUR. SFC RIDGING CONTINUES TO BE PROGGED TO BUILD IN FROM THE WEST...AND BRING MUCH DRIER AND COOLER AIR BACK TO THE FORECAST AREA FOR MID-WEEK. TEMPS ALOFT WILL HOVER ARND 10-13 DEG C...WITH HIGHS GENERALLY IN THE UPR 70S EACH DAY. OVERNIGHT LOWS WILL BE PLEASANT...IN THE UPR 50S TO LOW 60S. FRIDAY THROUGH THE WEEKEND... MINIMAL CHANGES TO THE GOING FORECAST...WITH THE TROUGH EXITING TO THE EAST AND MID-LVL FLOW BECOMING FLAT. AS THE SFC RIDGE PUSHES EAST...LLVL FLOW TURNS SOUTHERLY AND WARM/MOIST AIR BEGINS TO ADVECT BACK ACROSS THE REGION. A WEAK WAVE PUSHES OVERHEAD FRI...WITH A QUASI-STATIONARY BOUNDARY SETTING UP FOR THE WEEKEND AND ALLOWING A SEMI ACTIVE PATTERN. TEMPS WILL RETURN TO THE LOW/MID 80S. BEYOND THE CURRENT EXTENDED PERIODS...ENSEMBLES ARE ADVERTISING A HIGH CONFIDENCE RIDGE DEVELOPING ACROSS WESTERN CANADA AND DIGGING A TROUGH INTO THE GREAT LAKES/HUDSON BAY AREA EARLY NEXT WEEK. IF THIS SCENARIO VERIFIES...TEMPS WILL COOL BACK INTO THE UPR 70S TO KICK-OFF NEXT WEEK. CONFIDENCE...HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * POTENTIAL FOR CONVECTION OVERNIGHT. * LAKE BREEZE AFFECTING EITHER TERMINAL TUESDAY AFTERNOON. * POSSIBLE SHRAS NEAR LAKESHORE TUESDAY AFTERNOON. 2% //DISCUSSION...UPDATED 00Z... LAKE BREEZE RETREATING TOWARDS THE LAKE LATE THIS AFTN...SO IT IS NO LONGER A CONCERN. ATTENTION THEN TURNS TOWARDS CONVECTION ACROSS MN/WI ASSOC WITH A COLD FRONT AND AN UPPER LEVEL DISTURBANCE. THIS ACTIVITY IS FCST TO WORK ESE THRU THE EVENING AND OVERNIGHT REACHING THE AREA AFTER MIDNIGHT. FEEL PRETTY SURE THAT CONVECTION WILL PASS THRU THE AREA...BUT NOT SO SURE ON THE COVERAGE ONCE IT GETS HERE...HENCE MAINTAINING THE ONGOING VCTS GROUP LATE TONIGHT INTO EARLY TUESDAY MORNING WITH THE ACTIVITY CLEARING EAST BY MID MORNING. LOOKS LIKE THE LAKE BREEZE WILL ONCE AGAIN DEVELOP BY TUESDAY AFTN. BIG QUESTION IS WHETHER IT WILL IMPACT EITHER ORD OR MDW. THINK A SIMILAR SCENARIO WILL UNFOLD AS WHAT HAPPENED TODAY WHERE IT WILL HAVE TROUBLE MAKING IT TO EITHER TERMINAL GIVEN THE DECENT NW FLOW NEAR 10KTS. OBVIOUSLY MDW HAS THE BIGGEST CHANCE OF BEING AFFECTED. THERE IS ALSO A CHANCE THAT THERE COULD BE A FEW LIGHT SHRAS OR SPRINKLES THAT DVLP NEAR THE LAKESHORE/LAKE BREEZE TUESDAY AFTN. THINK THE UNCERTAINTIES IN PLACEMENT...COVERAGE AND THE TIMING SO LATE IN THE TAF PERIOD PRECLUDE INCLUDING A MENTION IN THE TAFS ATTM. WILL ALLOW LATER SHIFTS TO RE-EVALUATE THE THREAT. WOULD EXPECT IF THEY DID DVLP AND AFFECT A TERMINAL THAT CONDITIONS WOULD REMAIN VFR. 2% //ORD AND MDW CONFIDENCE...UPDATED 00Z... * MEDIUM CONFIDENCE THAT CONVECTION WILL DEVELOP...LOW THAT IT WILL IMPACT EITHER TERMINAL. * HIGH CONFIDENCE THAT A LAKE BREEZE WILL DEVLOP BY TUESDAY AFTERNOON...MEDIUM CONFIDENCE THAT IT WILL NOT AFFECT ORD...LOW CONFIDENCE THAT IT WILL AFFECT MDW. * LOW CONFIDENCE THAT SHRAS WILL DEVELOP NEAR THE LAKESHORE TUESDAY AFTERNOON...AND IF THEY DO WHETHER THEY WILL AFFECT EITHER TERMINAL. 2% //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY AND THURSDAY...VFR FRIDAY THROUGH SUNDAY...GENERALLY VFR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE PERIOD. 2% && .MARINE... 152 PM CDT NO MAJOR CONCERNS THROUGH THE PERIOD FOR THE MARINE FORECAST...WITH FOCUS MAINLY ON A SERIES OF RELATIVELY WEAK COLD FRONTAL PASSAGES THROUGH TUESDAY BEFORE HIGH PRESSURE SPREADS ACROSS THE WESTERN LAKES LATER WEDNESDAY NIGHT AND THURSDAY. IN THE NEAR TERM...LOW PRESSURE WAS PASSING NORTH OF THE LAKES FROM NORTHEASTERN ONTARIO INTO QUEBEC EARLY THIS AFTERNOON WITH A COLD FRONT TRAILING SOUTHWEST INTO FAR NORTHWEST INDIANA JUST SOUTH OF THE LAKE MICHIGAN SHORE AT 18Z. WINDS HAD BECOME VARIABLE ON THE SOUTHERN PORTION OF THE LAKE IN THE BAGGY GRADIENT BEHIND THE COLD FRONT...ALLOWING WEAK LAKE BREEZE DEVELOPMENT AROUND THE SOUTH END OF THE LAKE. FARTHER NORTH...WINDS HAVE BACKED TO THE SOUTHWEST WITH THE GRADIENT TIGHTENING A BIT IN ADVANCE OF THE NEXT MID-LEVEL DISTURBANCE TRACKING ACROSS THE UPPER MIDWEST. THIS MID-LEVEL WAVE WILL MOVE ACROSS THE REGION LATER TONIGHT...ALLOWING ANOTHER WEAK COLD FRONT TO SAG ACROSS THE NORTHERN PART OF THE LAKE LATE TONIGHT. YET ANOTHER MORE AMPLIFIED DISTURBANCE WILL SPREAD OVER THE WESTERN LAKES TUESDAY...WITH A DEVELOPING WEAK AREA OF SURFACE LOW PRESSURE MOVING EAST OF THE LAKE BY THE AFTERNOON AND NORTHWEST WINDS DEVELOPING. SPEEDS LOOK TO REMAIN FAIRLY MODEST...GENERALLY IN THE 15-20 KT RANGE DURING HIGHEST PERIODS. A THIRD DISTURBANCE SWINGS ACROSS THE NORTHERN LAKES...WI/MI LATE TUESDAY NIGHT...RESULTING IN SOME BACKING OF THE WINDS ON NORTHERN LAKE MICHIGAN...BUT THESE TOO TURN NORTHWEST AGAIN BY WEDNESDAY AFTERNOON. HIGH PRESSURE THEN PRESSES EASTWARD INTO THE MISSISSIPPI RIVER VALLEY BY WEDNESDAY EVENING...AND ACROSS LAKE MICHIGAN WEDNESDAY NIGHT AND THURSDAY. WINDS WILL THEN BECOME SOUTH-SOUTHEAST THURSDAY NIGHT AS THE RIDGE MOVES OFF TO THE EAST. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ 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
412 AM CDT SUN JUL 6 2014 .DISCUSSION... 320 AM CDT THE MAIN WEATHER CONCERNS THIS MORNING CONTINUE TO CENTER ON THE THREAT FOR STRONG TO SEVERE CONVECTION THIS EVENING. THINGS WILL BECOME NOTICEABLY MORE HUMID ACROSS THE AREA THIS AFTERNOON. ARE VWP AND PROFILER DATA INDICATES THE THE FLOW AT 850 MB IS NEARLY DUE WEST...AND AS A CONSEQUENCE OF THIS...WE ARE NOW BEGINNING TO SET UP SOME DECENT LOW LEVEL THETA E ADVECTION INTO NORTHERN ILLINOIS. REGIONAL RADAR IMAGERY HAS EVEN INDICATED A FEW SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS SOUTHEASTERN IOWA AND INTO MISSOURI EARLY THIS MORNING ALONG THE LEADING EDGE OF THE DEEPER MOISTURE. IT IS POSSIBLE THAT A FEW SHOWERS OR STORMS COULD DEVELOP ACROSS PORTIONS OF THE AREA LATER THIS MORNING/AFTERNOON AS THIS DEEPER MOISTURE BEGINS TO STREAM ACROSS THE AREA. HOWEVER...IT APPEARS THIS WOULD BE A LOW PROBABILITY. CLOUD COVER FROM THUNDERSTORM CLOUD DEBRIS TO THE NORTH SHOULD KEEP SKIES MOSTLY CLOUDY FOR AT LEAST MUCH OF THE MORNING TODAY...WHICH COULD LIMIT INSOLATION...MAKING THE THREAT FOR SURFACE BASED CONVECTION AHEAD OF THE COLD FRONT LESS LIKELY. THEREFORE...IT APPEARS THE HI RES CONVECTIVE ALLOWING MODELS MAY BE OVERDONE WITH THERE SUGGESTION OF ACTIVITY DEVELOPING ACROSS THE AREA DURING THE AFTERNOON AHEAD OF THE MAIN AREA OF ACTIVITY SET TO ARRIVE ACROSS FAR NORTHERN ILLINOIS BY EARLY THIS EVENING. NEVERTHELESS...I HAVE LEFT SLIGHT CHANCE POPS IN ACROSS THE AREA THIS AFTERNOON TO ACCOUNT FOR THE SMALL POTENTIAL OF ISOLATED ACTIVITY FIRING THIS AFTERNOON. THE MAIN FOCUS FOR SEVERE CONVECTION WILL BE ASSOCIATED WITH A COLD FRONT...CURRENTLY SHIFTING SOUTHEASTWARD ACROSS THE DAKOTAS. WITH A VERY WARM AND MOIST AIRMASS SHIFTING OVER THE AREA TODAY AHEAD OF THIS APPROACHING FRONTAL BOUNDARY...AT LEAST A MODERATELY UNSTABLE ATMOSPHERE IS EXPECTED...DESPITE THE POSSIBILITY OF LIMITED INSOLATION TODAY. MLCAPE VALUES IN EXCESS OF 2000 J/KG ARE EXPECTED BY EARLY THIS EVENING...THANKS IN PART TO THE ARRIVAL OF A CORRIDOR OF STEEPER MID LEVEL LAPSE RATES (700-500 MB ~7C/KM)...SAMPLED BY THE 00 UTC RAOBS RUNNING FROM THE PLAINS NORTHEASTWARD ACROSS THE PREFRONTAL AIRMASS OF THE UPPER MIDWEST. IF THE AREA DOES REMAINED CAPPED TO SURFACE BASED ACTIVITY THROUGH THE AFTERNOON...THE MAIN ACTIVITY WILL ARRIVE ACROSS NORTHERN ILLINOIS BY EARLY THIS EVENING. STRONG TO SEVERE CONVECTION IS EXPECTED TO DEVELOP BY LATE AFTERNOON TO OUR NORTH ACROSS SOUTHERN WISCONSIN IN RESPONSE TO THE APPROACHING COLD FRONT...WHICH WILL BE COMPLEMENTED BY MODEST MID/UPPER LEVEL HIGH FALLS...AND HENCE COOLING...ASSOCIATED WITH A DIGGING TROUGH ACROSS THE GREAT LAKES REGION. DEEP LAYER SHEAR WILL NOT BE OVERLY IMPRESSIVE ACROSS THE AREA THIS EVENING. HOWEVER...A MODEST 30 TO 35 KT WEST-NORTHWESTERLY FLOW IS EXPECTED TO SET UP AT 500 MB ACROSS THE AREA AND THIS SHOULD YIELD AT LEAST 30 TO 35 KT OF DEEP LAYER SHEAR...CAPABLE OF SUPPORTING SUPER CELLS AND BOWING LINE SEGMENTS ACROSS NORTHERN ILLINOIS. IT APPEARS THE THREAT FOR BOWING LINE SEGMENTS WITH STRONG WIND GUSTS WILL BECOME THE PRIMARY MODE OF CONVECTION DURING THE EVENING AS STORMS WILL LIKELY ORGANIZE A COLD POOL. THERE ALSO APPEARS TO BE A LOW END THREAT OF A TORNADO EARLY THIS EVENING...MAINLY ACROSS FAR NORTHERN ILLINOIS AND INTO WISCONSIN. LOW LEVEL WIND SHEAR OF 20-25 KT IS EXPECTED AS THE FLOW AROUND 2-3000 FT BEGINS TO INCREASE THIS EVENING. THE COMBINATION OF THIS AND LOW LCL HEIGHTS AND LOW LEVEL CAPE COULD SUPPORT AT LEAST A SHORT WINDOW OF A TORNADO THREAT. THE LINE OF CONVECTION SHOULD BEGIN TO AFFECT MOST AREAS NORTH OF INTERSTATE 80 BETWEEN 00 AND 04 UTC. GIVEN THE HIGH MOISTURE CONTENT OF THE ATMOSPHERE...THE STORMS COULD PRODUCE A BRIEF PERIOD OF VERY HEAVY RAINFALL...BUT THE FAIRLY PROGRESSIVE NATURE OF THE STORMS SHOULD LIMIT THE OVERALL TOTALS IN ANY GIVEN AREA. THE CONVECTIVE ACTIVITY MAY BEGIN TO WEAKEN LATER IN THE EVENING AND OVERNIGHT AS IT PROGRESSES TOWARDS MY SOUTHERN CWA. SO THE EXTENT OF THE SEVERE THREAT ACROSS MY SOUTHERN COUNTIES IS A BIT UNCERTAIN. IT APPEARS THINGS WILL QUIET DOWN FOR A SHORT PERIOD ON MONDAY...AS WE AWAIT THE NEXT SYSTEM. HOWEVER...CONDITIONS WILL LIKELY REMAIN VERY WARM AND HUMID ACROSS THE AREA...IN SPITE OF THE PASSAGE OF THE SURFACE BOUNDARY. UNDER WESTERLY SURFACE FLOW...TEMPERATURES COULD AGAIN END UP IN THE UPPER 80S TO NEAR 90. THERE IS A SMALL CHANCE OF AN AFTERNOON LAKE BREEZE ALONG THE IMMEDIATE SHORES OF INDIANA AND COOK COUNTY...GIVEN THE WEAKENING SYNOPTIC WIND FIELD IN THE AFTERNOON. THIS COULD RESULT IN SOME SLIGHTLY COOLER CONDITIONS THERE IN THE AFTERNOON. THE NEXT DECENT THREAT FOR CONVECTION APPEARS TO BE LATE MONDAY NIGHT INTO TUESDAY. ANOTHER...MORE ENERGETIC UPPER LEVEL DISTURBANCE IS FORECAST DIG SOUTHEASTWARD ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION BY TUESDAY. THIS COULD SET UP ANOTHER PERIOD OF STRONG CONVECTION AND HEAVY RAINFALL MONDAY NIGHT INTO TUESDAY GIVEN SOME STRONG DEEP LAYER SHEER. HOWEVER...AT THIS TIME IT APPEARS THE BIGGER SEVERE THREAT MAY REMAIN TO THE SOUTH AND WEST OF THE AREA...IN CLOSER PROXIMITY TO THE REMNANT FRONTAL BOUNDARY AND BETTER INSTABILITY EXPECTED TO RESIDE ACROSS THE CENTRAL PORTION OF THE STATE. THE THREAT FOR VERY HEAVY RAINFALL WITH THIS SYSTEM WILL NEED TO BE WATCHED THOUGH...AS THE POTENTIAL EXISTS FOR A PERIOD OF VERY HEAVY RAINFALL...ESPECIALLY ACROSS CENTRAL ILLINOIS INTO TUESDAY MORNING. ONCE THIS SYSTEM PASSES THE AREA ON TUESDAY...IT STILL APPEARS THINGS WILL QUIET DOWN FOR A COUPLE DAYS FOR THE SECOND HALF OF THE WEEK. COOL HIGH PRESSURE SHOULD SHIFT SOUTHEASTWARD ACROSS THE AREA...SETTING UP A FEW COOLER AND DRIER DAYS. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * CHANCE OF SHRA/TSRA LATE MORNING AND AFTERNOON SUNDAY * PERIOD OF SHRA/TSRA LIKELY LATER SUNDAY EVENING IZZI //DISCUSSION...UPDATED 06Z... VFR OVC WILL OVERSPREAD THE AREA OVERNIGHT AS MOISTURE BEGINS TO SPILL EAST INTO THE AREA. THE INCREASING MOISTURE WILL RESULT IN INCREASING INSTABILITY SUNDAY WHICH SEVERAL MODELS KEY IN ON TO KICK OFF SHOWERS AND THUNDERSTORMS DURING THE DAY SUNDAY. SEVERAL OTHER MODELS SUGGEST A CAP WILL PREVENT SHRA/TSRA DURING THE DAY WITH THREAT CONFINED TO THE FRONTAL PASSAGE SUNDAY EVENING. GIVEN THE STRONGLY CONFLICTING MODEL GUIDANCE REGARDING THE THREAT OF TSRA DURING THE DAY...HAVE OPTED TO JUST INCLUDE VCTS IN THE TAFS FOR NOW WHILE CONTINUING THE TEMPO DURING THE EVENING WHEN THE HIGHER THREAT SHOULD EXIST WITH THE FRONT. SOUTHWEST WINDS WILL INCREASE LATER SUNDAY MORNING AND CONTINUE INTO THE AFTERNOON WITH THE STRENGTH OF THE GUSTINESS LIKELY TO HINGE ON THE EXTENT OF CLOUD COVER AND SHRA/TSRA. IZZI //ORD AND MDW CONFIDENCE...UPDATED 09Z... * HIGH CONFIDENCE IN ALL ELEMENTS TONIGHT. * LOW CONFIDENCE ON TSRA THREAT DURING THE DAY SUNDAY * MEDIUM CONFIDENCE IN WIND/GUST SPEEDS SUNDAY * MEDIUM CONFIDENCE IN TSRA SUNDAY EVENING IZZI //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...CHANCE OF TSTMS MONDAY NIGHT. TUESDAY...CHANCE OF TSTMS CONTINUES INTO TUESDAY. WEDNESDAY...SLIGHT CHANCE OF TSTMS. THURSDAY...NONE. FRIDAY...CHANCE OF TSTMS. 2% && .MARINE... 325 AM CDT MODERATE SOUTHERLY WINDS LIKELY THROUGH THIS EVENING UNTIL A WEAK COLD FRONT MOVES ACROSS THE LAKE TONIGHT. WILL CONTINUE SMALL CRAFT ADVISORY FOR NEARSHORE WATERS THIS AFTERNOON INTO TONIGHT...THOUGH GUIDANCE HAS BACKED OFF A BIT ON SPEEDS WHICH COULD BE REASONABLE GIVEN POTENTIAL FOR CLOUD COVER LIMITING HEATING A BIT. CONFIDENCE IS PRETTY LOW IN WINDS THIS AFTERNOON AND EVENING...SO NOT PLANNING ANY CHANGES TO GOING HEADLINES. GENERALLY LOOKING FOR WESTERLY WINDS BEHIND THE FIRST FRONT MONDAY INTO TUESDAY BEFORE HIGH PRESSURE MOVES IN WED/THUR RESULTING IN LAND/LAKE BREEZE CIRCULATIONS DOMINATING WIND FLOW. IZZI && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...2 PM SUNDAY TO 4 AM MONDAY. SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...2 PM SUNDAY TO 10 PM SUNDAY. && $$ 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 National Weather Service Lincoln IL 331 AM CDT Sun Jul 6 2014 .DISCUSSION... ISSUED 320 AM CDT Sun Jul 6 2014 SHORT TERM...Today through Tuesday night 00Z models continue an unsettled weather pattern through Tuesday but differ with their qpf fields and with MCS activity. Models continue to trend faster with cold frontal passage getting south of central IL Tue night. Daily chances of showers and thunderstorms through Tue in tropical airmass with dewpoints in the upper 60s and lower 70s and highs in the upper 80s today and Monday. SPC has slight risk of severe storms this evening along and nw of a Springfield to Rantoul line with highest chances of severe storms later this afternoon into the evening over northern IL, eastern IA and southern WI where stronger shear is. Most of central and southeast IL is in a slight risk of severe storms on Monday night with another MCS moving se into IL and this one should have more widespread heavier rain. Cold front to pass se through central IL Tue and continue good chances of showers and thunderstorms and highest chances shifting into southeast IL Tue afternoon/evening. SPC has slight risk of severe storms se of central/se IL Tuesday where airmass is more unstable. Highs Tue in the low to mid 80s with muggy dewpoints in the upper 60s and lower 70s still. LONG TERM...Wednesday through Saturday night. Quieter weather returns to IL Wed/Thu as weak high pressure settles into the Midwest with somewhat less humid air and highs 80 to 85F. High pressure shifts into the eastern Great Lakes region during Friday and New England Sat with return southerly flow setting back up over IL. This to bring increase warmth and humidity along with isolated showers and thunderstorms from Friday into Sat night. 07 && .AVIATION... ISSUED 1159 PM CDT Sat Jul 5 2014 The MCV will trigger showers and isolated thunderstorms mainly east of a line from Champaign to Taylorville through 08z-09z tonight. However, additional shower development behind the wave will extend across our northern terminals of PIA and BMI the rest of the night. Radar returns are already showing up behind the wave all the way to Galesburg. Thunder will be isolated, and may not get within 5 miles of any terminal site overnight. Better chances of thunder will come later Sunday afternoon and evening with the next shortwave, which will be able to tap better instability. The latest HRRR and 4km NCEP WRF continue to indicate spotty showers/storms across the northern half of our forecast area the rest of tonight. Will keep VCSH for PIA and BMI through morning. Have continued to include VCTS for Sunday afternoon and evening for all terminal sites. Kept VFR throughout the forecast, but MVFR will be possible in heavier rains. Winds will remain southerly overnight, then shift to the S-SW Sunday morning as speeds increase to 12G20kt. Winds will diminish below 10kt with sunset Sun eve, remaining SW. Shimon && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1256 AM CDT SUN JUL 6 2014 .DISCUSSION... 852 PM CDT LOW CIRCULATION CONTINUES TO MOVE ACROSS THE FORECAST AREA GENERATING LIGHT RAIN WITH A FEW POCKETS OF MODERATE RAIN BASED ON RECENT OBS. EVEN THE LIGHTEST RADAR RETURNS ARE PRODUCING ENOUGH RAIN TO WET THE GROUND ACROSS MOST OF THE CHICAGO METRO AREA WITH THE STEADIER LIGHT RAIN ALONG AND SOUTH OF INTERSTATE 80. MOVEMENT CONTINUES TO BE SWIFT SO ACTIVITY WILL BE WINDING DOWN THROUGH LATE EVENING. NO MAJOR CHANGES EXPECTED TO THE OVERNIGHT FORECAST AT THIS POINT WITH SUBSIDENCE BUILDING IN BEHIND THE CURRENT WAVE AND THE LOW LEVEL JET FOCUSING ACROSS MISSOURI AND SOUTH- CENTRAL/SOUTHEAST IOWA OVERNIGHT. HOWEVER...INCREASING MOIST ADVECTION OVERNIGHT MAY BE ENOUGH TO TRIGGER ISOLATED TO SCATTERED SHOWERS AND STORMS SO WILL MAINTAIN SLIGHT AND LOW CHANCE POPS...WITH NOTHING COHERENT TO SUPPORT AN INCREASE AT THIS TIME. MDB //PREV DISCUSSION... 228 PM CDT MAIN FORECAST CHALLENGES TODAY ARE DEALING WITH CONVECTIVE CHANCES THROUGH MIDWEEK...INCLUDING THE POTENTIAL FOR SEVERE WEATHER SUNDAY EVENING/NIGHT. REST OF TODAY AND TONIGHT... AREA OF RAIN ASSOCIATED WITH A REMNANT MCV CURRENTLY MOVING ACROSS THE RIVER CONTINUES TO SLOWLY ERODE TO OUR WEST THIS AFTERNOON AS IT OUTRUNS THE INSTABILITY TO THE WEST AND ENCOUNTERS DRIER AIR. HAVE DROPPED POPS TO SLIGHT CHANCE MAINLY IN OUR WEST/SOUTHWEST COUNTIES THIS EVENING TO ACCOUNT FOR THIS AREA POSSIBLY FESTERING...BUT QPF VALUES SHOULD BE LOW. MORE ROBUST CONVECTION IS EXPECTED ACROSS PORTIONS OF MISSOURI AND CENTRAL/DOWNSTATE ILLINOIS TODAY. LATE THIS EVENING AND ESPECIALLY OVERNIGHT...VERY MODEST INSTABILITY STARTS TO OVERSPREAD THE AREA. GFS INDICATES MUCAPE VALUES INCREASING TO AROUND 500 J/KG BY DAYBREAK TOMORROW OVER THE CHICAGO AREA WITH SLIGHTLY BETTER VALUES TO THE WEST. THERE DOES NOT APPEAR TO BE A WELL DEFINED LOW LEVEL JET TONIGHT HOWEVER THERE IS AN AREA OF MODERATE LOW/MID LEVEL THETA-E ADVECTION THAT PUSHES ACROSS THE AREA WHICH MAY BE SUFFICIENT TO KICK OFF SHOWERS AND THUNDERSTORMS GIVEN THE INCREASING INSTABILITY. THERE IS NO CONCERN FOR SEVERE WEATHER OVERNIGHT. SUNDAY... UPPER PATTERN BEGINS TO AMPLIFY SUNDAY AS A SHORTWAVE TROUGH DIGS ACROSS THE CANADIAN PRAIRIES WITH SURFACE CYCLOGENESIS OCCURRING NEAR LAKE SUPERIOR. THIS WILL DRIVE A COLD FRONT TOWARDS THE AREA WITH H85 THERMAL RIDGE AHEAD LAYING OUT ACROSS THE AREA AS TEMPERATURES PUSH 20C SUNDAY AFTERNOON/EVENING. THIS SHOULD SUPPORT SURFACE TEMPS PUSHING THE 90 MARK DEPENDING ON CLOUD COVER AND ANY LINGERING MORNING CONVECTIVE DEBRIS. PERSISTENT SOUTHWEST FLOW WILL ALSO ADVECT DEWPOINTS TO AROUND 70 INTO THE AREA. MODELS CONTINUE TO TRY TO GENERATE CONVECTION EARLY IN THE DAY SUNDAY WITH MLCAPE VALUES GROWING TO IN EXCESS OF 3000 J/KG...HOWEVER SYNOPTICALLY WE SEEM TO BE IN A FAVORABLE AREA FOR THE CAP TO HOLD MUCH OF THE DAY WITH LITTLE IN THE WAY OF FORCING WITH MID LEVEL HEIGHT TENDENCIES FAIRLY NEUTRAL. AS THE SURFACE FRONT AND BETTER MID LEVEL HEIGHT FALLS START TO APPROACH THE AREA IN THE EVENING...CHANCES FOR THUNDERSTORMS WILL INCREASE. DEEP LAYER SHEAR OF 30-40KT WILL BE SUFFICIENT TO SUSTAIN AN ORGANIZED SEVERE THREAT DESPITE FALLING A LITTLE BEYOND THE MOST FAVORABLE DIURNAL TIMING. IN ADDITION...PWATS OF AROUND 2 INCHES POOLING ALONG THE FRONT WILL RESULT IN EFFICIENT RAIN PRODUCERS SO WILL LIKELY HAVE TO MONITOR HYDRO CONDITIONS CLOSELY OVERNIGHT TOO. MONDAY THROUGH TUESDAY... THE UPPER LEVELS CONTINUE TO AMPLIFY EARLY NEXT WEEK WITH THE MIDLEVEL BAROCLINIC ZONE SETTLING TO OUR SOUTH BY TUESDAY. CHANCES FOR PRECIP WILL BE BEST SOUTHEAST OF I-57 MONDAY WHERE THE FRONTAL BOUNDARY IS PROGGED TO SLOWLY CONTINUE TO SAG SOUTH...THEN BY TUESDAY THERE WILL BE CHANCES FOR THUNDERSTORMS AREA WIDE AS COOLER MID LEVEL AIR OVERSPREADS THE REGION WITH STEEP LOW/MID LEVEL LAPSE RATES DEVELOPING AND MOST MODELS INDICATING A SHEARED VORT MAX DIGGING ACROSS THE REGION. WITH THE JET STREAM SAGGING SOUTH ACROSS THE AREA...FOR NOW AT LEAST IT APPEARS THAT DEEP LAYER SHEAR VALUES WILL BE STRONG ENOUGH THAT THERE IS SOME CONCERN FOR SEVERE WEATHER EACH DAY. WEDNESDAY THROUGH FRIDAY... LONG WAVE TROUGH IN PLACE ACROSS THE MIDWEST/GREAT LAKES MIDWEEK WILL GRADUALLY SLIDE TOWARDS THE ATLANTIC COAST BY FRIDAY WITH THE OVERALL PATTERN FLATTENING OUT AGAIN. SURFACE HIGH BUILDS OVERHEAD AND SHOULD PROVIDE QUIET CONDITIONS FOR THE LATTER HALF OF THE WEEK WITH RETURN FLOW BACK INTO THE AREA STARTING AS EARLY AS FRIDAY. TEMPERATURES WILL BE NEAR OR POSSIBLY SLIGHTLY BELOW NORMAL WEDNESDAY AND THURSDAY. WARMER TEMPERATURES ARE POSSIBLE BY FRIDAY BUT GFS IS MUCH QUICKER BRINGING THE THERMAL RIDGE BACK OVER THE AREA AS COMPARED TO THE ECMWF...SO GIVEN THE MODEL DIFFERENCES OPTED TO MAINTAIN GENERAL MODEL CONSENSUS FOR NOW. DEUBELBEISS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * CHANCE OF SHRA/TSRA LATE MORNING AND AFTERNOON SUNDAY * PERIOD OF SHRA/TSRA LIKELY LATER SUNDAY EVENING IZZI //DISCUSSION...UPDATED 06Z... VFR OVC WILL OVERSPREAD THE AREA OVERNIGHT AS MOISTURE BEGINS TO SPILL EAST INTO THE AREA. THE INCREASING MOISTURE WILL RESULT IN INCREASING INSTABILITY SUNDAY WHICH SEVERAL MODELS KEY IN ON TO KICK OFF SHOWERS AND THUNDERSTORMS DURING THE DAY SUNDAY. SEVERAL OTHER MODELS SUGGEST A CAP WILL PREVENT SHRA/TSRA DURING THE DAY WITH THREAT CONFINED TO THE FRONTAL PASSAGE SUNDAY EVENING. GIVEN THE STRONGLY CONFLICTING MODEL GUIDANCE REGARDING THE THREAT OF TSRA DURING THE DAY...HAVE OPTED TO JUST INCLUDE VCTS IN THE TAFS FOR NOW WHILE CONTINUING THE TEMPO DURING THE EVENING WHEN THE HIGHER THREAT SHOULD EXIST WITH THE FRONT. SOUTHWEST WINDS WILL INCREASE LATER SUNDAY MORNING AND CONTINUE INTO THE AFTERNOON WITH THE STRENGTH OF THE GUSTINESS LIKELY TO HINGE ON THE EXTENT OF CLOUD COVER AND SHRA/TSRA. IZZI //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN ALL ELEMENTS TONIGHT. * LOW CONFIDENCE ON TSRA THREAT DURING THE DAY SUNDAY * MEDIUM CONFIDENCE IN WIND/GUST SPEEDS SUNDAY * MEDIUM CONFIDENCE IN TSRA SUNDAY EVENING IZZI //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...CHANCE OF TSTMS MONDAY NIGHT. TUESDAY...CHANCE OF TSTMS CONTINUES INTO TUESDAY. WEDNESDAY...SLIGHT CHANCE OF TSTMS. THURSDAY...NONE. FRIDAY...CHANCE OF TSTMS. 2% && .MARINE... 206 PM CDT HIGH PRESSURE IS SLOWLY SHIFTING EAST WITH SOUTH WINDS ACROSS THE LAKE. WINDS WILL INCREASE TO 15-25 KT ACROSS ALL OF THE OPEN WATERS TONIGHT AS THE GRADIENT TIGHTENS AHEAD OF THE NEXT LOW. MAY SEE WINDS GET TO CLOSE TO 30 KT OVER THE NORTHERN HALF OF THE LAKE...BUT THINKING THE MARINE LAYER WILL BE STABLE ENOUGH TO KEEP HIGHER WINDS FROM REACHING THE SURFACE. WINDS SHOULD BECOME HAZARDOUS TO SMALL CRAFT TOMORROW AFTERNOON AND EVENING SO ISSUED A SMALL CRAFT ADVISORY FOR ALL OF THE NEARSHORE WATERS. HAVE THE SMALL CRAFT ADVSY LASTING 6 HOURS LONGER OVER NW INDIANA AS SW WINDS 20-25 KT SHOULD PERSIST THROUGH THE EVENING THERE. THE LOW PASSES OVER SOUTHERN ONTARIO TOMORROW AND TOMORROW NIGHT WITH ITS COLD FRONT SWEEPING THROUGH LATE TOMORROW NIGHT. WINDS DIMINISH AND BECOME W TO NW BEHIND THE FRONT. A WEAK COLD FRONT MOVES SOUTH THROUGH AT LEAST MID LAKE MONDAY NIGHT INTO TUESDAY WITH WINDS BECOMING N TO NE BEHIND IT. ANOTHER WEAK LOW SWINGS THROUGH TUESDAY AND WINDS BECOME NW. GUIDANCE THEN DIFFERS GREATLY ON THE PATTERN FROM WEDNESDAY ONWARD. IN GENERAL LOOKING AT LIGHT WESTERLY FLOW WITH HIGH PRESSURE LATE NEXT WEEK LEADING TO PERIODS OF ONSHORE FLOW. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...2 PM SUNDAY TO 4 AM MONDAY. SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...2 PM SUNDAY TO 10 PM SUNDAY. && $$ 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 National Weather Service Lincoln IL 1159 PM CDT Sat Jul 5 2014 .DISCUSSION... ISSUED 900 PM CDT Sat Jul 5 2014 A well-defined MCV continues to make progress across IL, with showers expanding farther south and east with time. The back edge of the precip is about to reach the IL river, while the leading edge has reached a line from just north of Springfield to near Champaign. Have increased PoPs to likely the rest of the evening following the projected path of the wave. After midnight, the HRRR and 4km WRF still indicate some redevelopment of showers and possibly a thunderstorm along a line from W-E across central IL. That convection timing is a bit uncertain, even at this late hour, so we will continue with chance PoPs after midnight north of I-72. Clouds will likely prevail overnight, which will help to keep low temps slightly warmer than under clear conditions. The low temp forecast appears reasonable, so will continue with low to mid 60s. Showers and storms are expected to redevelop late Sunday afternoon or evening as the next significant shortwave moves across IL. Instability params look favorable for a few strong to severe storms Sunday night. Main updates tonight were in the weather and PoP grids to match expected trends. Shimon && .AVIATION... ISSUED 1159 PM CDT Sat Jul 5 2014 The MCV will trigger showers and isolated thunderstorms mainly east of a line from Champaign to Taylorville through 08z-09z tonight. However, additional shower development behind the wave will extend across our northern terminals of PIA and BMI the rest of the night. Radar returns are already showing up behind the wave all the way to Galesburg. Thunder will be isolated, and may not get within 5 miles of any terminal site overnight. Better chances of thunder will come later Sunday afternoon and evening with the next shortwave, which will be able to tap better instability. The latest HRRR and 4km NCEP WRF continue to indicate spotty showers/storms across the northern half of our forecast area the rest of tonight. Will keep VCSH for PIA and BMI through morning. Have continued to include VCTS for Sunday afternoon and evening for all terminal sites. Kept VFR throughout the forecast, but MVFR will be possible in heavier rains. Winds will remain southerly overnight, then shift to the S-SW Sunday morning as speeds increase to 12G20kt. Winds will diminish below 10kt with sunset Sun eve, remaining SW. Shimon && .PREV DISCUSSION... ISSUED 300 PM CDT Sat Jul 5 2014 Models continue to look similar with overall upper level pattern and surface features. However, they still differ on the smaller/mesoscale features, which affect where and when pcpn will occur. So took a blend and tried to make adjustments with location and timing of pops in the short term, based on general synoptic feature forecast; and to stay in sync with surrounding offices. Main concerns will be chance pops through the forecast period, along with temps next couple of days. SHORT TERM...Tonight through Tuesday night Remnants of last night`s MCS is finally diminishing, as the HRRR model forecasted earlier this morning. Associated MCV will continue to move east over northern IL this evening, but will likely not do much as it will be moving into drier air. However, will be keeping chance pops in the area this evening and overnight as any leftover outflow boundaries could still produce some showers and thunderstorms. Area covered will be in the north and central, leaving the southeast dry. Another MCS is expected to develop late tonight back west where the boundary and best moisture is located at. This MCS is expected to move toward the area late tonight and into the area tomorrow. So will be keeping chc pops in the north and central parts of the cwa tomorrow. The outflow boundary from this MCS should have higher dewpoint air to work with in the area, so will have little higher pops for tomorrow night in the area, covering all the cwa. The chance of pcpn will continue Mon and Mon night as boundaries and moisture will still remain around the area. The front will also be getting closer to the cwa Mon night, but really get into the area for Tue and Tue night. This will bring likely pops into the cwa for the whole area sometime between Tue and Tue night. As the front moves through the area Tue night, pcpn chances will diminish to the northwest. Temps will be quite warm the next two days as the cwa will remain in the warm sector. Moisture will also be on the increase, so conditions will be humid/muggy at times; typical for July summer in central Illinois. LONG TERM...Wednesday through Saturday After the front passes Tue night, conditions will be dry the remainder of the week. Long term models show some pcpn coming back into the area from the west late in the week and into the weekend, but not confident with that forecast at the moment. So will opt to keep what the consensus models show for now. Later adjustments are likely with this type of pattern in the summer. Auten && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
554 PM CDT SUN JUL 6 2014 .SHORT TERM /TONIGHT/... ISSUED AT 319 PM CDT SUN JUL 6 2014 CLOUDS TODAY CONTINUE TO COMPLICATE THIS EVENINGS CONVECTION CHANCES. LOW LEVEL STRATUS WHICH FORMED IN THE SOUTHERLY MOISTURE FEED ACROSS THE AREA HAVE KEPT TEMPERATURES ABOUT 5 TO 7 DEGREES COOLER THAN FORECAST. ALOFT WE ARE ALSO DEALING WITH A SUFFICIENT MID LEVEL CAP AT H700 WITH TEMPS FROM 10 TO 12C IN THE WARM SECTOR THAT HAS TENDED TO KEEP CONVECTION EAST OF THE AREA. COMBINED WITH RELATIVELY WEAK CONVERGENCE ALONG THE APPROACHING COOL FRONT... AFTERNOON CONVECTION HAS BEEN SLOW TO TAKE OFF ALONG THE BOUNDARY IN MN/WESTERN WI. BUFR SOUNDINGS SHOW THAT CAP SHOULD REMAIN IN PLACE ALONG AND WEST OF I35 THIS EVENING...WHILE ERODING EAST OF THAT LINE WITH THE HELP OF THE DEVELOPING CONVECTION WHICH SHOULD BUILD BACK WEST SOUTHWEST WITH TIME THROUGH 06Z. GENERALLY SCATTERED CONVECTION IS EXPECTED ACROSS THE AREA SINCE THE CAP ALOFT WILL BE STRONGER AS THE STORMS MOVE BACK WEST INTO IOWA. NEARLY ALL THE MODELS INCLUDING THE HRRR FAVOR THIS SCENARIO. SO...HAVE TRIMMED POP/THUNDERSTORM CHANCES FROM I35 WEST WITH THE EXCEPTION OF AREAS ALONG THE IA/MO BORDER WHERE LATE MID EVENING SOME RESIDUAL CONVECTION MAY LINGER ALONG THE BOUNDARY. AIRMASS OVER EASTERN AND NORTHERN IA STILL RATHER UNSTABLE AND ANY STORMS THAT BUILD BACK TO THE WEST WILL STILL HAVE A CHANCE TO PRODUCE SVR WIND GUSTS AND LARGE HAIL. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 319 PM CDT SUN JUL 6 2014 INITIALLY CONDITIONS ARE EXPECTED TO BE QUIET MONDAY MORNING WITH SURFACE BOUNDARY STALLED IN MO/KS. SHORTWAVE WILL BE RAPIDLY ADVANCING SOUTHEAST THROUGH THE NORTHERN PLAINS. MODELS ALL INDICATE SURFACE MOISTURE RETURNING WITH DEWPOINTS INTO THE U60S/L70S BY AFTERNOON. HOWEVER...BEST LOW LEVEL CONVERGENCE APPEARS TO REMAIN JUST SOUTH OF IOWA AND THIS WILL LIKELY BE THE FOCUS OF THE MOST INTENSE CONVECTION BY LATE AFTERNOON INTO MONDAY NIGHT. THIS CONVECTION WILL LIKELY IMPACT SOUTHWEST THIRD OR SO OF THE STATE WITH THE POTENTIAL FOR SEVERE WINDS AND LARGE HAIL. HEAVY RAINS WILL ALSO BE POSSIBLE ALTHOUGH THE FOCUS AGAIN MAY BE JUST SOUTH AND WEST OF THE STATE WHERE BEST LOW LEVEL CONVERGENCE IS EXPECTED TO OCCUR. OTHERWISE...STRONG MID LEVEL FORCING WILL PRODUCE CONVECTION FARTHER NORTHEAST THROUGH MUCH OF THE REMAINDER OF CENTRAL IOWA LATE MONDAY AFTERNOON/EVENING BUT WITH LESS COVERAGE. DRIER AIR WILL FITLER INTO THE STATE IN THE WAKE OF THE SYSTEM ON TUESDAY WITH RELATIVELY QUIET WEATHER INTO THE MIDDLE OF THE WEEK WITH TEMPERATURES AT OR BELOW SEASONAL NORMS. BOTH GFS AND EURO CONTINUE NORTHWEST FLOW INTO THE LATER PORTION OF THE FORECAST WITH NEXT SYSTEM ARRIVING THURSDAY NIGHT INTO FRIDAY. THIS WILL BE THE NEXT APPRECIABLE THREAT OF CONVECTION WITH GFS TRYING TO LINGER ADDITIONAL STORMS INTO THE WEEKEND AS IT LEAVES THE FRONT IN VICINITY OF IA. EURO PUSHES THE BOUNDARY FARTHER SOUTH WITH RELATIVELY TRANQUIL WEATHER FOR NEXT WEEKEND. && .AVIATION...06/00Z ISSUED AT 549 PM CDT SUN JUL 6 2014 COLD FRONT ACROSS IA FROM NERN CORNER TO THE SWRN CORNER WILL MOVE SOUTHEAST AND BE SOUTHEAST OF THE TAF SITES BY 06Z. SCATTERED LINE OF THUNDERSTORMS ALONG THE FRONT WILL BE AROUND THE ERN TAF SITES EARLY THIS EVENING. WITH LIGHT WINDS OVERNIGHT...EXPECT TO SEE SOME MVFR FOG CONDITIONS DEVELOP AROUND SUNRISE. LIGHT WINDS AND VFR CONDITIONS ON MONDAY. OUTLOOK...SECOND COLD FRONT WILL MOVE INTO THE STATE MONDAY NIGHT INTO EARLY TUE. EXPECT TO SEE WIDESPREAD THUNDERSTORM DEVELOPMENT...ESPECIALLY OVER THE SRN THIRD OF THE STATE MONDAY NIGHT WITH ACTIVITY MOVING OUT TUE. HIGH PRESSURE WILL BRING VFR CONDITIONS WED THROUGH THU. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...REV LONG TERM...COGIL AVIATION...MS JUL 14
AREA FORECAST DISCUSSION
NWS DES MOINES IA
319 PM CDT SUN JUL 6 2014 .SHORT TERM /TONIGHT/... ISSUED AT 319 PM CDT SUN JUL 6 2014 CLOUDS TODAY CONTINUE TO COMPLICATE THIS EVENINGS CONVECTION CHANCES. LOW LEVEL STRATUS WHICH FORMED IN THE SOUTHERLY MOISTURE FEED ACROSS THE AREA HAVE KEPT TEMPERATURES ABOUT 5 TO 7 DEGREES COOLER THAN FORECAST. ALOFT WE ARE ALSO DEALING WITH A SUFFICIENT MID LEVEL CAP AT H700 WITH TEMPS FROM 10 TO 12C IN THE WARM SECTOR THAT HAS TENDED TO KEEP CONVECTION EAST OF THE AREA. COMBINED WITH RELATIVELY WEAK CONVERGENCE ALONG THE APPROACHING COOL FRONT... AFTERNOON CONVECTION HAS BEEN SLOW TO TAKE OFF ALONG THE BOUNDARY IN MN/WESTERN WI. BUFR SOUNDINGS SHOW THAT CAP SHOULD REMAIN IN PLACE ALONG AND WEST OF I35 THIS EVENING...WHILE ERODING EAST OF THAT LINE WITH THE HELP OF THE DEVELOPING CONVECTION WHICH SHOULD BUILD BACK WEST SOUTHWEST WITH TIME THROUGH 06Z. GENERALLY SCATTERED CONVECTION IS EXPECTED ACROSS THE AREA SINCE THE CAP ALOFT WILL BE STRONGER AS THE STORMS MOVE BACK WEST INTO IOWA. NEARLY ALL THE MODELS INCLUDING THE HRRR FAVOR THIS SCENARIO. SO...HAVE TRIMMED POP/THUNDERSTORM CHANCES FROM I35 WEST WITH THE EXCEPTION OF AREAS ALONG THE IA/MO BORDER WHERE LATE MID EVENING SOME RESIDUAL CONVECTION MAY LINGER ALONG THE BOUNDARY. AIRMASS OVER EASTERN AND NORTHERN IA STILL RATHER UNSTABLE AND ANY STORMS THAT BUILD BACK TO THE WEST WILL STILL HAVE A CHANCE TO PRODUCE SVR WIND GUSTS AND LARGE HAIL. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 319 PM CDT SUN JUL 6 2014 INITIALLY CONDITIONS ARE EXPECTED TO BE QUIET MONDAY MORNING WITH SURFACE BOUNDARY STALLED IN MO/KS. SHORTWAVE WILL BE RAPIDLY ADVANCING SOUTHEAST THROUGH THE NORTHERN PLAINS. MODELS ALL INDICATE SURFACE MOISTURE RETURNING WITH DEWPOINTS INTO THE U60S/L70S BY AFTERNOON. HOWEVER...BEST LOW LEVEL CONVERGENCE APPEARS TO REMAIN JUST SOUTH OF IOWA AND THIS WILL LIKELY BE THE FOCUS OF THE MOST INTENSE CONVECTION BY LATE AFTERNOON INTO MONDAY NIGHT. THIS CONVECTION WILL LIKELY IMPACT SOUTHWEST THIRD OR SO OF THE STATE WITH THE POTENTIAL FOR SEVERE WINDS AND LARGE HAIL. HEAVY RAINS WILL ALSO BE POSSIBLE ALTHOUGH THE FOCUS AGAIN MAY BE JUST SOUTH AND WEST OF THE STATE WHERE BEST LOW LEVEL CONVERGENCE IS EXPECTED TO OCCUR. OTHERWISE...STRONG MID LEVEL FORCING WILL PRODUCE CONVECTION FARTHER NORTHEAST THROUGH MUCH OF THE REMAINDER OF CENTRAL IOWA LATE MONDAY AFTERNOON/EVENING BUT WITH LESS COVERAGE. DRIER AIR WILL FITLER INTO THE STATE IN THE WAKE OF THE SYSTEM ON TUESDAY WITH RELATIVELY QUIET WEATHER INTO THE MIDDLE OF THE WEEK WITH TEMPERATURES AT OR BELOW SEASONAL NORMS. BOTH GFS AND EURO CONTINUE NORTHWEST FLOW INTO THE LATER PORTION OF THE FORECAST WITH NEXT SYSTEM ARRIVING THURSDAY NIGHT INTO FRIDAY. THIS WILL BE THE NEXT APPRECIABLE THREAT OF CONVECTION WITH GFS TRYING TO LINGER ADDITIONAL STORMS INTO THE WEEKEND AS IT LEAVES THE FRONT IN VICINITY OF IA. EURO PUSHES THE BOUNDARY FARTHER SOUTH WITH RELATIVELY TRANQUIL WEATHER FOR NEXT WEEKEND. && .AVIATION...06/18Z ISSUED AT 1238 PM CDT SUN JUL 6 2014 MAIN CONCERNS REMAIN THE LOW CLOUDS NORTH AND POTENTIAL FOR CONVECTION THIS AFTERNOON AND EVENING. OVERNIGHT MCS ACROSS MN CREATED A LARGE CI SHIELD WHICH HAS KEPT LOW ST FROM BURNING OFF THROUGH THE MORNING OVER THE NORTH. MVFR ST ALSO FORMED IN AREA OF MODEST LOW LEVEL MOISTURE ADVECTION OVER THE SOUTH CENTRAL. CIGS WILL LIFT MORE RAPIDLY THIS AFTERNOON...WITH INSTABILITY BUILDING WEST. OVER THE NORTHEAST CONVERGENCE ALONG THE BOUNDARY WOULD FAVOR SOME CONVECTION FOR KMCW...KALO THROUGH 00Z. ELSEWHERE...SOME CONCERNS THAT STRONG CAP SHOWING UP IN BUFR SOUNDINGS WILL HOLD FOR KDSM AND KOTM EVEN THIS AFTERNOON AND EVENING. CURRENT CONVECTION REMAINS WELL NORTH OF AREA ALONG BOUNDARY FROM WEST CENTRAL WI TO KMSP. WILL MONITOR FOR ANY EXPANSION INTO CENTRAL IOWA BUT FOR NOW...TRENDS SUGGEST NORTHEAST SECTIONS MOST AT RISK FOR DEVELOPMENT THIS AFTERNOON/EVENING. /REV && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...COGIL AVIATION...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1125 PM CDT SAT JUL 5 2014 .UPDATE... ISSUED AT 1124 PM CDT SAT JUL 5 2014 UPDATE ON ZONES WILL BE OUT SHORTLY FOR DELETION OF THE ISOLATED THUNDERSTORMS OVER THE SOUTHEAST FOR THE REMAINDER OF TONIGHT. UPDATE ISSUED AT 644 PM CDT SAT JUL 5 2014 WILL MAKE A QUICK UPDATED TO ADJUST THE PRECIPITATION THIS EVENING. THUNDERSTORMS NOT FORMING ON THE OUTFLOW AS EXPECTED...SO LOWERED POPS. && .SHORT TERM /TONIGHT/... ISSUED AT 312 PM CDT SAT JUL 5 2014 MCV/MCS CURRENTLY EXITING THE AREA TO THE SOUTHEAST THIS AFTERNOON. TEMPS HAVE BEEN HELD BACK BUT ARE RECOVERING ACROSS THE WEST. WARM FRONT OVER NORTHERN MO THIS MORNING HAS BEEN REINFORCED BY OUTFLOW BOUNDARY FROM MESOSCALE SYSTEM...BUT SHOULD BEGIN TO LIFT NORTH DURING THE NIGHTTIME HOURS. MODELS AT ODDS ABOUT CONVECTION COVERAGE TONIGHT...BUT HINTING AT SOME DEVELOPMENT ALONG THE EDGE OF THE RETREATING WARM FRONT/OUTFLOW BOUNDARY THROUGH IOWA OVERNIGHT. WEAKEST PORTION OF THE H700 CAP FAVORS THE EASTERN AND SOUTHERN SECTIONS. HRRR REFLECTS SOME DEVELOPMENT WITH A BAND OF STORMS FORMING AFT 04Z NEAR I80 CORRIDOR...VARIOUS OTHER SOLUTIONS ALSO FAVOR SOME DEVELOPMENT OVER THE EAST OR ALONG THE IOWA/MO BORDER BETWEEN 00 AND 06Z AS NOCTURNAL LOW LEVEL JET INCREASES AND IMPINGES ALONG THE WARM FRONT/OUTFLOW BOUNDARY. WILL INCREASE POPS AGAIN BY MID TO LATE EVENING OVER THE EAST AND SOUTH...WEAK STEERING CURRENTS SUGGEST SOME SOUTHEASTERLY DRIFT ALONG THE BOUNDARY OVERNIGHT. ONCE AGAIN...IF CONVECTION GETS A BIT MORE ORGANIZED COULD SEE A QUICK INCH OR TWO TOTAL FROM ANY STRONGER CELLS THAT DEVELOP. WARM CLOUD DEPTHS PUSHING 13-14KFT AND PRECIPITABLE WATER STILL RUNNING 1.5 INCHES OVER THE SOUTHEAST THIRD. FOR NOW WILL NOT ISSUE HEADLINES AS COVERAGE IS EXPECTED TO BE LIMITED. AFTER LAST NIGHTS/THIS MORNING RAINFALL... GRIDDED FLASH FLOOD GUIDANCE HAS LOWERED TO 1 TO 1.5 INCHES OVER A GOOD SHARE OF THE SOUTH WITH 3 HOURLY GUIDANCE NEARING 2 INCHES OVER THE SAME LOCATIONS. THE SOUTHERN TWO TIER COUNTIES CONTINUE HIGHER...WITH 2 INCH VALUES FOR 1 HOUR AND 2 TO 3 INCH VALUES FOR 3 HOUR GUIDANCE. NEEDLESS TO SAY...NOT MUCH CAPACITY LEFT IN SOIL FOR ADDITIONAL RAINFALL OVER THE NEXT FEW DAYS. LOWS WILL CREEP UP TONIGHT. DESPITE THE LACK OF MUCH SUNSHINE THIS AFTERNOON...LOWS WILL REMAIN IN THE MID TO UPPER 60S AS DEW POINTS HAVE RISEN WITH THE RETURN OF MOISTURE TO THE AREA. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 312 PM CDT SAT JUL 5 2014 LONG TERM FORECAST PERIOD WILL FEATURE RATHER ACTIVE WX AND AN OVERALL UPPER AIR PATTERN OF WESTERLIES INVOF OF IOWA...EVOLVING FROM BROAD NORTHWEST FLOW TO BROAD CYCLONIC FLOW. MAIN CHALLENGES EARLY IN THE PERIOD WILL BE TSRA CHANCES SUNDAY AFTN/EVE AS WELL AS LATE MONDAY INTO TUE. FCST PERIOD BEGINS WITH IOWA SOUTH OF THE WESTERLIES. SUNDAY IS EXPECTED TO BE MORE SUMMER-LIKE...WITH THERMAL RIDGING AND MOISTURE TRANSPORT RESULTING IN SEASONALLY HOT AND HUMID CONDITIONS. TEMPS RANGING FROM THE UPPER 80S TO MIDDLE 90S ALONG WITH DEWPOINTS IN THE 70S ARE EXPECTED. AN IMPULSE WILL SWEEP A COOL FRONT INTO THE STATE ON SUNDAY. QUESTION IS HOW FAR WEST ALONG THE FRONT WILL THE TSRA DEVELOP. ALTHOUGH INSTABILITY IS PROGGED TO BE RESPECTABLE...CAPPING WILL INCREASE TOWARD THE WEST ACROSS THE STATE. BEST CHANCES OF TSRA WILL BE IN EASTERN IOWA...WHERE THE CAP WILL BE WEAKER AND UPPER-LEVEL FORCING WILL BE STRONGER. LOW- LEVEL JET WILL INCREASE MOISTURE TRANSPORT BY LATE EVENING...SO HAVE BROUGHT CHANCE POPS ALONG THE SOUTHERN BORDER OF THE STAGE BY THAT TIME. FRONT IS EXPECTED TO BECOME QUASI-STATIONARY INVOF THE IA-MO BORDER BY LATE SUNDAY NIGHT. STRONGER H5 SHORTWAVE WILL BRING ANOTHER CHANCE OF TSRA BY LATE MON. BOTH THERMODYNAMIC AND KINEMATIC FORCING WILL BE STRONGER WITH THIS SYSTEM THAN THE ONE ON LATE SUN. THIS SHORTWAVE WILL PUSH ANOTHER COOL FRONT SOUTH THROUGH IOWA...EVENTUALLY OVERTAKING THE QUASI-STATIONARY BOUNDARY INVOF THE IA-MO BORDER. AMPLE INSTABILITY AHEAD OF THE ADVANCING FRONT IS EXPECTED TO PROMOTE SFC-BASED TSRA DEVELOPMENT. SHEAR PARAMETERS SUGGEST A FEW SUPERCELLS POSSIBLE EARLY WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS...BUT CANNOT RULE OUT AN ISOLATED TORNADO. THE CONVECTION IS EXPECTED TO GROW UPSCALE INTO AN MCS AND PUSH SOUTHEAST INTO THE EVENING. AFTER THE FROPA MONDAY NIGHT/TUE MORNING...CYCLONIC WESTERLIES WILL DOMINATE THE WX INTO LATER IN THE WEEK. NEXT CHANCE OF PCPN WILL ARRIVE THURSDAY INTO THURSDAY NIGHT AS A WEAK IMPULSE PASSES OVER THE REGION. THE 12Z ECMWF IS ADVERTISING A STRONGER SHORTWAVE BRINGING ANOTHER BOUNDARY THROUGH THE CWA ON SATURDAY. THE 12Z RUN WAS CONSISTENT IN THIS REGARD WITH THE 00Z RUN. THIS SOLUTION IS ADMITTEDLY DIFFERENT THAN LAST NIGHT/S LONG TERM PACKAGE WHICH KEPT THE ACTIVITY NORTH OF THE CWA. SHRA/TSRA WILL BE POSSIBLE WITH THIS BOUNDARY AS IT SWEEPS THROUGH THE CWA. THIS BOUNDARY WILL BRING A SLIGHTLY COOLER AIR MASS OVER THE CWA TO END THE WEEKEND. && .AVIATION...06/06Z ISSUED AT 1110 PM CDT SAT JUL 5 2014 COLD FRONT FROM NERN ND INTO CO WILL MOVE SOUTHEAST INTO IA SUN AND PASS SOUTHEAST OF THE STATE BY THE END OF THE FORECAST PERIOD. TWO FORECAST PROBLEMS ARE THE STRATUS TONIGHT AND THUNDERSTORMS TOMORROW. WILL LIKELY SEE WIDESPREAD MVFR AND IFR CONDITIONS IN STRATUS AND FOG OVERNIGHT INTO THE EARLY MORNING WITH CONDITIONS LIFTING BY MID TO LATE MORNING. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT AFTER 18Z AND MOVE SOUTHEAST WITH THE FRONT. TRIED TO TIME THE PASSAGE OF THE FRONT AND THUS THE THUNDERSTORM CHANCES. BEST CHANCE FOR THUNDERSTORMS WILL BE OVER THE NORTHEAST. OUTLOOK...FRONT WILL DROP SOUTHEAST OF THE STATE SUNDAY NIGHT AND BECOME STATIONARY. A SECOND COLD FRONT WILL MOVE THROUGH THE AREAS MONDAY WITH ANOTHER CHANCE FOR THUNDERSTORMS MONDAY NIGHT INTO EARLY TUE. HIGH PRESSURE WILL BRING FAIR CONDITIONS TO THE STATE WED AND THU. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MS JUL 14 SHORT TERM...REV LONG TERM...ZOGG AVIATION...MS JUL 14
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1117 PM CDT SAT JUL 5 2014 .UPDATE... ISSUED AT 644 PM CDT SAT JUL 5 2014 WILL MAKE A QUICK UPDATED TO ADJUST THE PRECIPITATION THIS EVENING. THUNDERSTORMS NOT FORMING ON THE OUTFLOW AS EXPECTED...SO LOWERED POPS. && .SHORT TERM /TONIGHT/... ISSUED AT 312 PM CDT SAT JUL 5 2014 MCV/MCS CURRENTLY EXITING THE AREA TO THE SOUTHEAST THIS AFTERNOON. TEMPS HAVE BEEN HELD BACK BUT ARE RECOVERING ACROSS THE WEST. WARM FRONT OVER NORTHERN MO THIS MORNING HAS BEEN REINFORCED BY OUTFLOW BOUNDARY FROM MESOSCALE SYSTEM...BUT SHOULD BEGIN TO LIFT NORTH DURING THE NIGHTTIME HOURS. MODELS AT ODDS ABOUT CONVECTION COVERAGE TONIGHT...BUT HINTING AT SOME DEVELOPMENT ALONG THE EDGE OF THE RETREATING WARM FRONT/OUTFLOW BOUNDARY THROUGH IOWA OVERNIGHT. WEAKEST PORTION OF THE H700 CAP FAVORS THE EASTERN AND SOUTHERN SECTIONS. HRRR REFLECTS SOME DEVELOPMENT WITH A BAND OF STORMS FORMING AFT 04Z NEAR I80 CORRIDOR...VARIOUS OTHER SOLUTIONS ALSO FAVOR SOME DEVELOPMENT OVER THE EAST OR ALONG THE IOWA/MO BORDER BETWEEN 00 AND 06Z AS NOCTURNAL LOW LEVEL JET INCREASES AND IMPINGES ALONG THE WARM FRONT/OUTFLOW BOUNDARY. WILL INCREASE POPS AGAIN BY MID TO LATE EVENING OVER THE EAST AND SOUTH...WEAK STEERING CURRENTS SUGGEST SOME SOUTHEASTERLY DRIFT ALONG THE BOUNDARY OVERNIGHT. ONCE AGAIN...IF CONVECTION GETS A BIT MORE ORGANIZED COULD SEE A QUICK INCH OR TWO TOTAL FROM ANY STRONGER CELLS THAT DEVELOP. WARM CLOUD DEPTHS PUSHING 13-14KFT AND PRECIPITABLE WATER STILL RUNNING 1.5 INCHES OVER THE SOUTHEAST THIRD. FOR NOW WILL NOT ISSUE HEADLINES AS COVERAGE IS EXPECTED TO BE LIMITED. AFTER LAST NIGHTS/THIS MORNING RAINFALL... GRIDDED FLASH FLOOD GUIDANCE HAS LOWERED TO 1 TO 1.5 INCHES OVER A GOOD SHARE OF THE SOUTH WITH 3 HOURLY GUIDANCE NEARING 2 INCHES OVER THE SAME LOCATIONS. THE SOUTHERN TWO TIER COUNTIES CONTINUE HIGHER...WITH 2 INCH VALUES FOR 1 HOUR AND 2 TO 3 INCH VALUES FOR 3 HOUR GUIDANCE. NEEDLESS TO SAY...NOT MUCH CAPACITY LEFT IN SOIL FOR ADDITIONAL RAINFALL OVER THE NEXT FEW DAYS. LOWS WILL CREEP UP TONIGHT. DESPITE THE LACK OF MUCH SUNSHINE THIS AFTERNOON...LOWS WILL REMAIN IN THE MID TO UPPER 60S AS DEW POINTS HAVE RISEN WITH THE RETURN OF MOISTURE TO THE AREA. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 312 PM CDT SAT JUL 5 2014 LONG TERM FORECAST PERIOD WILL FEATURE RATHER ACTIVE WX AND AN OVERALL UPPER AIR PATTERN OF WESTERLIES INVOF OF IOWA...EVOLVING FROM BROAD NORTHWEST FLOW TO BROAD CYCLONIC FLOW. MAIN CHALLENGES EARLY IN THE PERIOD WILL BE TSRA CHANCES SUNDAY AFTN/EVE AS WELL AS LATE MONDAY INTO TUE. FCST PERIOD BEGINS WITH IOWA SOUTH OF THE WESTERLIES. SUNDAY IS EXPECTED TO BE MORE SUMMER-LIKE...WITH THERMAL RIDGING AND MOISTURE TRANSPORT RESULTING IN SEASONALLY HOT AND HUMID CONDITIONS. TEMPS RANGING FROM THE UPPER 80S TO MIDDLE 90S ALONG WITH DEWPOINTS IN THE 70S ARE EXPECTED. AN IMPULSE WILL SWEEP A COOL FRONT INTO THE STATE ON SUNDAY. QUESTION IS HOW FAR WEST ALONG THE FRONT WILL THE TSRA DEVELOP. ALTHOUGH INSTABILITY IS PROGGED TO BE RESPECTABLE...CAPPING WILL INCREASE TOWARD THE WEST ACROSS THE STATE. BEST CHANCES OF TSRA WILL BE IN EASTERN IOWA...WHERE THE CAP WILL BE WEAKER AND UPPER-LEVEL FORCING WILL BE STRONGER. LOW- LEVEL JET WILL INCREASE MOISTURE TRANSPORT BY LATE EVENING...SO HAVE BROUGHT CHANCE POPS ALONG THE SOUTHERN BORDER OF THE STAGE BY THAT TIME. FRONT IS EXPECTED TO BECOME QUASI-STATIONARY INVOF THE IA-MO BORDER BY LATE SUNDAY NIGHT. STRONGER H5 SHORTWAVE WILL BRING ANOTHER CHANCE OF TSRA BY LATE MON. BOTH THERMODYNAMIC AND KINEMATIC FORCING WILL BE STRONGER WITH THIS SYSTEM THAN THE ONE ON LATE SUN. THIS SHORTWAVE WILL PUSH ANOTHER COOL FRONT SOUTH THROUGH IOWA...EVENTUALLY OVERTAKING THE QUASI-STATIONARY BOUNDARY INVOF THE IA-MO BORDER. AMPLE INSTABILITY AHEAD OF THE ADVANCING FRONT IS EXPECTED TO PROMOTE SFC-BASED TSRA DEVELOPMENT. SHEAR PARAMETERS SUGGEST A FEW SUPERCELLS POSSIBLE EARLY WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS...BUT CANNOT RULE OUT AN ISOLATED TORNADO. THE CONVECTION IS EXPECTED TO GROW UPSCALE INTO AN MCS AND PUSH SOUTHEAST INTO THE EVENING. AFTER THE FROPA MONDAY NIGHT/TUE MORNING...CYCLONIC WESTERLIES WILL DOMINATE THE WX INTO LATER IN THE WEEK. NEXT CHANCE OF PCPN WILL ARRIVE THURSDAY INTO THURSDAY NIGHT AS A WEAK IMPULSE PASSES OVER THE REGION. THE 12Z ECMWF IS ADVERTISING A STRONGER SHORTWAVE BRINGING ANOTHER BOUNDARY THROUGH THE CWA ON SATURDAY. THE 12Z RUN WAS CONSISTENT IN THIS REGARD WITH THE 00Z RUN. THIS SOLUTION IS ADMITTEDLY DIFFERENT THAN LAST NIGHT/S LONG TERM PACKAGE WHICH KEPT THE ACTIVITY NORTH OF THE CWA. SHRA/TSRA WILL BE POSSIBLE WITH THIS BOUNDARY AS IT SWEEPS THROUGH THE CWA. THIS BOUNDARY WILL BRING A SLIGHTLY COOLER AIR MASS OVER THE CWA TO END THE WEEKEND. && .AVIATION...06/06Z ISSUED AT 1110 PM CDT SAT JUL 5 2014 COLD FRONT FROM NERN ND INTO CO WILL MOVE SOUTHEAST INTO IA SUN AND PASS SOUTHEAST OF THE STATE BY THE END OF THE FORECAST PERIOD. TWO FORECAST PROBLEMS ARE THE STRATUS TONIGHT AND THUNDERSTORMS TOMORROW. WILL LIKELY SEE WIDESPREAD MVFR AND IFR CONDITIONS IN STRATUS AND FOG OVERNIGHT INTO THE EARLY MORNING WITH CONDITIONS LIFTING BY MID TO LATE MORNING. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT AFTER 18Z AND MOVE SOUTHEAST WITH THE FRONT. TRIED TO TIME THE PASSAGE OF THE FRONT AND THUS THE THUNDERSTORM CHANCES. BEST CHANCE FOR THUNDERSTORMS WILL BE OVER THE NORTHEAST. OUTLOOK...FRONT WILL DROP SOUTHEAST OF THE STATE SUNDAY NIGHT AND BECOME STATIONARY. A SECOND COLD FRONT WILL MOVE THROUGH THE AREAS MONDAY WITH ANOTHER CHANCE FOR THUNDERSTORMS MONDAY NIGHT INTO EARLY TUE. HIGH PRESSURE WILL BRING FAIR CONDITIONS TO THE STATE WED AND THU. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MS JUL 14 SHORT TERM...REV LONG TERM...ZOGG AVIATION...MS JUL 14
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
708 PM CDT Mon Jul 7 2014 ...Updated for aviation discussion... .SHORT TERM...(This evening through Tuesday) ISSUED AT 227 PM CDT MON JUL 7 2014 Tonight: The main focus for tonight is where convection will be located and how severe. Right now, visible satellite imagery shows some developing cumulus across the Plains of east-central Colorado. Expect further development of cumulus into northwest Kansas through the afternoon. This activity is along a frontal boundary. Convective allowing models break out thunderstorms this evening with the best chances along the I-70 corridor. Storms may extend all the way down to Highway 96, though, later tonight. As far as severity, some of the models want to mix out current dewpoints, which, so far, is not happening as much as the models indicate. Running the thermodynamic and wind-related parameters through the Large Hail Parameter (LHP) comes up with a value of 6. This basically suggests that hail could potentially be up to the size of golf balls. Not really sure if we will get a sustained weakly rotating updraft or not, so hail could be smaller. There is not a threat of tornadoes. There could be 60+ mph outflow winds, as an inverted-v thermodynamic profile is expected. Have the highest pops for Trego and Ellis counties and then taper values quickly southward as thunderstorms are not expected along and south of a line from Coolidge to St. John. The most recent HRRR has storms south of this line, however, this model tends to overdo cold pools and resultant upscale growth. Overnight lows will be in the 60s/70s. Tomorrow: Much cooler temperatures are expected for tomorrow as the aforementioned front sinks south of the region. Have lowered maximums as the majority of the models are now cooler with "cold" air advection in the wake of the front. Expecting maximums mostly in the mid 80s along with 10-20 mph N/NE winds. There could be some storms along and south of the Arkansas river...have slight pops in after 21Z, but most of the precipitation will be during the long term period. .LONG TERM...(Tuesday night through Monday) ISSUED AT 308 PM CDT MON JUL 7 2014 The cold front which will come down Tuesday will slow its southward push and weaken Tuesday Night. The frontal zone, around 800mb will be across the northern Panhandles northeastward along the KS-OK border, which will be a focus for at least isolated or widely scattered thunderstorms. It is still unclear whether a small mesoscale convective system (MCS) will develop along the frontal zone or not (and if so, whether it will be this far north into southwest Kansas or not). For now, we will keep Chance POPs (25+) across far southwest Kansas from roughly Elkhart to Meade with Slight Chance (15-24) from roughly Scott City to Stafford. The front will dissolve by Wednesday, however temperatures will still be mild by early/mid July standards with highs in the upper 80s to lower 90s. Any thunderstorms Wednesday through early/mid evening should be confined to the higher terrain west of the southwest Kansas region. Warm frontogenesis will increase in the 06-12Z time frame early Thursday morning in the 850-700mb layer, and we will continue to carry Chance POPs across central and south-central Kansas. The updated forecast does reduce the POPs along/west of Highway 283, though. The summer ridge will build in the mid-upper troposphere with lower troposphere responding with quite a bit warmer temperatures in the +27 to +29C range at 850mb. Even slightly warmer temperatures Friday will support afternoon surface temperatures in the 99 to 101F territory. We will carry some Slight Chance POPs in the western/northwester zones for mainly diurnal lee trough/higher terrain storms which may drift into western Kansas. As we head into the upcoming weekend, we will start to see some amplification occurring in the jet stream pattern cross northwestern North America, with a pronounced ridge developing along the Pacific Coast of British Columbia. This would lead to downstream troughing throughout much of the rest of Canada into the Upper Midwest region of the CONUS. What this would mean for southwestern Kansas is the eventual frontal passage, perhaps as early as late Saturday (ECMWF) or Sunday (Canadian GEM). During the 14-17 July time frame, there is a large degree of uncertainty in how the upper tropospheric pattern will play out, but the ECMWF does suggest a much cooler and wetter scenario during this 8-10 Day time frame. To a lesser degree, the GFS does hint at this, but is also quite a bit delayed in longwave troughing across the northern CONUS. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 705 PM CDT MON JUL 7 2014 A cold front will sweep across western Kansas tonight, resulting in a wind shift from the south to the north at 15kts. A line of thunderstorms preceding the front may affect KHYS, KDDC and KGCK between 01z and 05Z, with wind gusts as high as 45kts, brief heavy rain and small hail. Outside of the thunderstorms, VFR conditions will prevail. && .PRELIMINARY POINT TEMPS/POPS... DDC 67 86 64 88 / 30 20 20 20 GCK 66 85 63 89 / 30 20 20 20 EHA 67 85 64 91 / 10 30 30 20 LBL 69 87 65 92 / 10 30 30 20 HYS 66 85 63 88 / 40 10 10 10 P28 72 89 67 89 / 10 20 20 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Sugden LONG TERM...Umscheid AVIATION...Finch
AREA FORECAST DISCUSSION
NWS TOPEKA KS
637 PM CDT Mon Jul 7 2014 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Tuesday) Issued at 259 PM CDT MON JUL 7 2014 Currently monitoring visible satellite this afternoon where multiple boundaries are positioned across the region. A weak boundary was tracking southeast through the CWA while a stronger area of outflow winds was pushing southward into southern NE and far northern KS. A weak warm front resided near the KS/NE border while the stronger cold front was located over southern SD. Remnant cloud cover from this morning`s showers were finally exiting east central KS, allowing temps to quickly rise into the 90s, as heat indices approach the low 100s. Dewpoints continue to mix down into the low and middle 60s. On the water vapor in the mid levels, two vorticity maxima were noted over northern NE and a stronger wave dropping southeast from North Dakota. Late this afternoon, surface CAPE near 3000 J/KG while effective shear increases between 30 and 50 kts is supportive of strong to severe convection. Main limiting factor for surface based convection is the capping inversion holding across much of the area as seen on the 19Z KTOP RAOB. Latest 4-KM WRF, HRRR, and RUC keep convection at bay until after 00Z but could not entirely rule out a few updrafts developing along the leading outflow boundary or warm front in vicinity of KS/NE border. If a storm develops, it will be capable of large hail and damaging winds. Highest chances for severe convection reside after 00Z as scattered storms along the reinforcing cold front and upper trough shift south and east across Nebraska, northeast Kansas, and northern Missouri. the progressive nature of the system, in addition to stout forward propagating Corfidi vectors approaching 55 to 60 kts signal damaging winds to be the primary hazards with this evening`s storms. Large hail is also possible. Locally heavy rainfall will depend on the speed of the line and any training convection that occurs towards central KS along the boundary. Tornado potential is low in far northern KS where the frontal boundary and weak low level shear maximizes near 15 kts. Likely precip chances were focused over northern, northeast, and east central areas based on the position of the upper trough axis as the main line of storms quickly shifts southeast overnight. Guidance is on track to clear precip through by Tuesday mid morning as skies become mostly sunny during the afternoon. A cooler and stable airmass in the system`s wake will only bring temps to the 80s for highs. Northerly winds increase between 10 and 15 mph sustained. .LONG TERM...(Tuesday Night through Monday) Issued at 259 PM CDT MON JUL 7 2014 Wed/Thurs...Should have a cool night Tuesday night as skies clear and cooler airmass with lower dewpoints slides southward into the forecast area. Strong sunshine and deeper mixing on Wednesday should return high temperatures back into the middle 80s east to upper 80s west. Still some consensus that front retreats back northeast overnight Wednesday night into Thursday and brings a chance for storms as it does so, although coverage may be shut down quickly as warm temps and cap return aloft by the late afternoon Thursday. Eastern counties may be able to stay a few degrees cooler depending on how fast clouds and precip chances diminish. As upper flow becomes slightly northwest into Thursday night, passing wave still progged to generate an MCS mainly north of our area then sliding east. Kept slight chances as some models slide this boundary into our forecast area. Some discrepancies in the extended as EC lays this boundary over the area through the weekend while GFS is farther north and a warmer drier solution. The GFS ensembles favor the warmer pattern and have left the extended as such. && .AVIATION...(For the 00Z TAFs through 00Z Tuesday Evening) Issued at 637 PM CDT MON JUL 7 2014 VFR conditions are expected outside of convective activity. Line of TSRA expected to move through the terminals in the 04Z-07Z time period. Wind gusts to 45kts or higher are possible and have included in a tempo group for now. VSBYS in TSRA to become mvfr to briefly ifr with stronger storms. Expect vsbys to improve after 09Z and convective activity to be moving south of the terminals by 10Z. Winds will shift to the north and northeast behind the front. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Bowen LONG TERM...67 AVIATION...53
AREA FORECAST DISCUSSION
NWS GOODLAND KS
208 PM MDT SUN JUL 6 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 203 PM MDT SUN JUL 6 2014 NORTHERLY FLOW ON THE EAST SIDE OF A RIDGE OVER THE ROCKIES WILL CONTINUE ACROSS THE HIGH PLAINS TONIGHT AND MONDAY. A SURFACE TROUGH WILL BE ACROSS NORTHWEST KANSAS TONIGHT WITH A COLD FRONT POISED TO MOVE SOUTH INTO THE REGION MONDAY AFTERNOON. A SURFACE TROUGH DIVIDING GENERALLY THE NORTHWEST HALF OF THE FA FROM THE SOUTHEAST HALF WILL SERVE AS A FOCUS POINT FOR SOME ISOLATED CONVECTION THIS EVENING. CAPE IS AROUND 2000 J/KG ACROSS THE SOUTHEAST FA WITH INCREASING CIN ACROSS THE NORTHWEST. VERY WARM H7 TEMPERATURES WILL HAVE TO BE OVERCOME. FOR THIS REASON WILL KEEP POPS AT SLIGHT CHANCE FOR THIS EVENING. THERE ARE SOME TIMING DIFFERENCES FOR THE FRONT BETWEEN THE GFS AND NAM ON MONDAY. THE GFS IS LATER WITH PRECIPITATION ASSOCIATED WITH THE FRONT. FOR THIS REASON PLAN TO KEEP POPS LOWER MONDAY AFTERNOON. FORCING IS INDICATED BY BOTH MODELS BUT MOISTURE IS LESS THAN IDEAL DURING THE AFTERNOON. PLAN TO CONTINUE SLIGHT CHANCE AND CHANCE POPS MONDAY AFTERNOON. MIN TEMPERATURES TONIGHT WILL COOL TO THE MID AND UPPER 60S. MAX TEMPERATURES MONDAY WILL RISE TO THE MID AND UPPER 90S. COOLER LOWER 90S WILL BE FOUND ACROSS NORTHERN AREAS WHERE CLOUD COVER HAS INCREASED. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 203 PM MDT SUN JUL 6 2014 MONDAY NIGHT THROUGH TUESDAY NIGHT CHANCES FOR RAINFALL RETURN TO THE AREA. THE BEST CHANCE FOR RAINFALL WILL BE MONDAY EVENING AS A COLD FRONT MOVES SOUTH INTO THE AREA. BEHIND THE FRONT NORTHERLY WINDS WILL BECOME BREEZY AS A LOW LEVEL JET DEVELOPS AND FOLLOWS THE FRONT THROUGH THE AREA. SOUNDINGS SHOW A FAIRLY DRY ENVIRONMENT BELOW 600MB AS THE FRONT MOVES THROUGH...BUT SATURATE ABOVE THIS LAYER. IN ADDITION THETA-E LAPSE RATES ABOVE 600MB CONTINUE TO SUGGEST CONVECTIVE INSTABILITY AS THE FRONT MOVES THROUGH. DO NOT ANTICIPATE STRONG THUNDERSTORMS FORMING AS THE FRONT MOVES THROUGH DUE TO THE LACK OF CAPE. STORM MOTION WILL BE TO THE EAST SO LOCATIONS EAST OF HIGHWAY 25 WILL HAVE A BETTER SHOT AT RECEIVING RAINFALL. AFTER MIDNIGHT STORMS SHOULD MOVE OUT OF THE AREA AS THE LIFT DECLINES WITH THE FRONT SOUTH OF THE AREA. TUESDAY A HIGH PRESSURE AT 850MB MOVES ACROSS THE AREA. BEHIND THE RIDGE THE FRONT WILL MOVE BACK ACROSS THE AREA FROM THE WEST AS A WARM FRONT DURING THE AFTERNOON. SOUNDINGS SHOW SOME SURFACE CAPE TO WORK WITH BUT BASED ON THE SOUNDING PROFILES...DOUBT MORE THAN ISOLATED STORMS WILL DEVELOP ALONG THE FRONT OVER KIT CARSON/CHEYENNE COUNTIES. BY TUESDAY EVENING STORM COVERAGE MAY INCREASE OVER THE SOUTHWEST PART OF THE AREA ALONG THE STALLED FRONT. HOWEVER NOT TOO OPTIMISTIC OF STORM DEVELOP SINCE THE BEST SURFACE MOISTURE WILL BE SOUTHWEST OF THE AREA. STORM MOTION WILL BE TO THE EAST...SO THERE IS A POSSIBILITY STORMS MAY MOVE INTO KIT CARSON/CHEYENNE COUNTIES FROM THE WEST. STORMS SHOULD DIMINISH DURING THE LATE EVENING AS THE ENVIRONMENT STABILIZES. WEDNESDAY THROUGH SUNDAY NORTHWEST UPPER LEVEL FLOW WILL CONTINUE OVER THE AREA UNTIL FRIDAY WHEN THE UPPER LEVEL RIDGE OVER THE ROCKIES MOVES ONTO THE PLAINS. AN UPPER LEVEL TROUGH WILL FOLLOW THE RIDGE ACROSS THE PLAINS FRIDAY SO WILL CONTINUE WITH THE RAINFALL CHANCES FOR FRIDAY. OVERALL NOT VERY IMPRESSED WITH THE RAINFALL CHANCES FOR THIS TIME FRAME DUE TO THE RATHER BROAD NATURE OF THE TROUGHS MOVING THROUGH THE NORTHWEST FLOW DUE TO THE CLOSE PROXIMITY OF THE RIDGE. RAINFALL CHANCES LOOK BETTER SUNDAY WHEN A STRONG UPPER LEVEL SHORT WAVE TROUGH MOVES ACROSS THE AREA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1116 AM MDT SUN JUL 6 2014 VFR CONDITIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24 HOURS. HOWEVER, THERE IS A SLIGHT CHANCE OF THUNDERSTORMS AT KGLD AND KMCK AROUND 00Z MONDAY. THE HRRR MODEL INDICATES A FEW STORMS NEAR BOTH SITES AND THIS SEEMS REASONABLE WITH A TROUGH AND COLD FRONT NEAR KMCK FOR STORMS TO INITIATE ON. ALSO UP SLOPE FLOW INTO THE HIGHER TERRAIN OF COLORADO MAY PRODUCE A FEW STORMS THAT WILL MOVE EAST ACROSS THE KANSAS BORDER INTO THE KGLD AREA. STORMS WILL BE BRIEF WITH CLEARING OVERNIGHT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...FS LONG TERM...JTL AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1120 AM MDT SUN JUL 6 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 355 AM MDT SUN JUL 6 2014 HOT TEMPERATURES WILL CONTINUE TODAY WITH A BROAD AREA OF HIGH PRESSURE IN PLACE ACROSS THE WESTERN UNITED STATES. CONDITIONS WILL BE MOSTLY DRY...ALTHOUGH WITH TEMPERATURES IN THE EAST AROUND 100 DEGREES WITH DEWPOINTS AROUND 60 DEGREES...THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS DEVELOPING IN THE SURFACE CONVERGENT AREA NEAR THE SURFACE THROUGH EXPECTED TO BE POSITIONED ACROSS THE FORECAST AREA LATE TODAY AND THIS EVENING. THE APEX OF THE UPPER RIDGE SHARPENS OVER THE PACIFIC NORTHWEST TONIGHT AS A SHORT WAVE TROUGH SLIDES DOWN THE EAST SIDE OF THE NORTHWEST FLOW OF THE INCREASING AMPLITUDE PATTERN. THIS SHORT WAVE TROUGH IS EXPECTED CLIP THE CENTRAL HIGH PLAINS REGION MONDAY NIGHT AND HELP PUSH A COLD FRONT THROUGH THE FORECAST AREA. SKY COVER WILL INCREASE ACROSS THE REGION...KEEPING THE NORTHERN SECTIONS OF THE FORECAST AREA A FEW DEGREES COOLER THAN ON SUNDAY. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED ACROSS THE FORECAST AREA LATE MONDAY AFTERNOON THROUGH MONDAY EVENING WITH A GREATER COVERAGE OF STORMS ACROSS THE NORTHEAST IN CLOSER PROXIMITY TO THE UPPER SHORT WAVE TROUGH. THERE IS A SLIGHT RISK OF SEVERE STORMS WITH LARGE HAIL BEING THE MAIN THREAT. COOLER TEMPERATURES CLOSER TO THE AVERAGE OF THIS TIME OF YEAR ARE EXPECTED ON TUESDAY IN THE WAKE OF THE COLD FRONT AS HIGH PRESSURE MOVES IN AT THE SURFACE. THE COLD FRONT MAY GET HUNG UP ALONG THE FRONT RANGE OF COLORADO AND EXTEND INTO THE VICINITY OF THE PANHANDLE REGION...SO THERE IS A POSSIBILITY OF ANOTHER ROUND OF THUNDERSTORMS ACROSS MAINLY THE SOUTHWEST PORTIONS OF THE FORECAST AREA LATE TUESDAY AFTERNOON AND EVENING AS ADDITIONAL IMPULSES MOVE THROUGH THE NORTHWEST FLOW ALOFT. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 355 AM MDT SUN JUL 6 2014 A FAIRLY SEASONABLE PATTERN THROUGH LATE NEXT WEEK INTO THE WEEKEND. AN UPPER HIGH/RIDGE WILL EVOLVE OVER THE GREAT BASIN REGION DURING THIS PERIOD PROVIDING GENERALLY NORTHWEST FLOW AT UPPER LEVELS. SOME MODEL DISAGREEMENT ON THE EVOLUTION OF THIS RIDGE OVER THE WEEKEND...WITH THE ECMWF QUICK TO BUILD ANOTHER RIDGE TO THE WEST WHILE THE GFS/GEFS KEEP A NEARLY-FLAT RIDGE OVER THE CENTRAL PLAINS DURING THE WEEKEND. AT LOW LEVELS FLOW WILL BE OUT OF THE SOUTH...BRINGING WARM AND MOIST GULF AIR INTO THE REGION. AT THE SURFACE MAY HAVE A WEAK WARM FRONT MOVE UP ACROSS THE AREA THURSDAY AFTERNOON...AND IT LOOKS LIKELY A COLD FRONT WILL BE APPROACHING FROM THE NORTH LATE SATURDAY. OTHERWISE WILL RELY ON TERRAIN AND SMALLER-SCALE OUTFLOW FEATURES TO SERVE AS A FOCUS FOR STORMS EACH DAY. THIS PERIOD IS APPROACHING THE HOTTEST TIME OF THE YEAR /JULY 13-15 BASED ON 1982-2010 NORMALS/ AND AT THIS POINT IT DOES NOT APPEAR WE WILL BE TOO FAR OFF FROM NORMAL /90.3 TO 90.5 ACROSS THE EXTENDED FORECAST PERIOD/. TEMPS EACH DAY WILL BE IN THIS RANGE...WITH THE HOTTEST DAY LOOKING LIKE THURSDAY OR FRIDAY WHEN 850MB TEMPS WILL BE IN THE LOW 30S C...INDICATIVE OF HIGHS IN THE MID 90S WITH THE POSSIBILITY OF A FEW SPOTS REACHING TRIPLE DIGITS. LOWS WILL IN THE MID TO UPPER 60S...EXCEPT ALONG/EAST OF HIGHWAY 83 WHERE LOWS ARE MORE LIKE THE LOW 70S. AM NOT PARTICULARLY EXCITED ABOUT PRECIP CHANCES DURING THE PERIOD DUE TO THE INHIBITION PROVIDED BY THE VERY WARM LOW/MID LEVELS /700MB TEMPS OVER 14C MOST OF THE TIME/. BEST CHANCE FOR STORMS LOOKS TO BE WEDNESDAY AFTERNOON/EVENING. WILL HAVE OVER 1500 J/KG MUCAPE AVAILABLE WITH AROUND 40 KTS OF EFFECTIVE SHEAR. T-TD SPREAD AT THE SURFACE WILL BE AROUND 25 DEG F...WHICH COULD LEAD TO SOME GUSTY THUNDERSTORMS. STORM MOTIONS WILL BE 5 TO 10KTS...NOT PARTICULARLY FAST...BUT PWATS HAVE TRENDED LOW IN RECENT MODEL RUNS /NOW IN THE 1.2 TO 1.4 INCH RANGE INSTEAD OF THE 1.5-PLUS RANGE/ SO HEAVY RAINFALL MAY NOT BE AS BIG OF A CONCERN AS FIRST THOUGHT. UPPER FORCING WILL BE PROVIDED BY WAY OF MID-LEVEL SHORTWAVE TROUGH THAT MOVES ACROSS CENTRAL ROCKIES...AND FOCUS FOR CONVECTION WILL BE MOSTLY TERRAIN-BASED WITH PERHAPS A FEW CELLS FORMING ALONG A WEAK SURFACE TROUGH ACROSS THE COLORADO PLAINS. FOR THE REST OF THE WEEK...PRECIP CHANCES ARE MARGINAL THURS/FRI DUE TO CAPPING AND RELATIVELY WEAK DISTURBANCES THAT MOVE ACROSS THE REGION...THOUGH THUNDERSTORM ACTIVITY FROM WEDNESDAY MAY MODIFY THE ENVIRONMENT TO BETTER SUPPORT STORMS DURING THESE DAYS. WIND SHEAR WILL BE MUCH LESS SUPPORTIVE OF ORGANIZED STORMS...AND THUS EXPECT MORE WEAK TERRAIN-BASED AND PULSE STORMS. SATURDAY DO EXPECT STORMS ASSOCIATED WITH THE APPROACHING COLD FRONT...THOUGH LAPSE RATES ARE NOT VERY STEEP...SO STRONG THUNDERSTORM DEVELOPMENT DOES NOT APPEAR LIKELY AT THIS POINT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1116 AM MDT SUN JUL 6 2014 VFR CONDITIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24 HOURS. HOWEVER, THERE IS A SLIGHT CHANCE OF THUNDERSTORMS AT KGLD AND KMCK AROUND 00Z MONDAY. THE HRRR MODEL INDICATES A FEW STORMS NEAR BOTH SITES AND THIS SEEMS REASONABLE WITH A TROUGH AND COLD FRONT NEAR KMCK FOR STORMS TO INITIATE ON. ALSO UPSLOPE FLOW INTO THE HIGHER TERRAIN OF COLORADO MAY PRODUCE A FEW STORMS THAT WILL MOVE EAST ACROSS THE KANSAS BORDER INTO THE KGLD AREA. STORMS WILL BE BRIEF WITH CLEARING OVERNIGHT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...LOCKHART LONG TERM...JJM AVIATION...FS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1152 PM CDT Sat Jul 5 2014 ...Updated for 06Z Aviation Forecast... .UPDATE... Issued at 950 PM CDT SAT JUL 5 2014 Short term models (HRRR, RAP13) continue to try to develop convection over eastern Kansas this evening, and it continues to not develop to this point. New NAM not as aggressive as previous two runs, but still has spotty precip and more persistent precip in east central KS through tonight. Water vapor imagery showing one mid- level shortwave trough move southeastward across central and eastern KS, and weak subsidence behind it may be helping to suppress evening convection in KS. Models do have postive theta-e advection in the 850 to 700 mb layer for later this evening through 1 AM, so have not removed POPs from eastern KS, but have dropped them for north central KS for tonight. Any thunderstorms that do form will obviously have the potential for heavy rain with precipitable water values near 2" and decent moisture transport evident at 850 mb. && .SHORT TERM...(This Evening through Sunday) Issued at 244 PM CDT SAT JUL 5 2014 Forecast today quickly challenged with mesoscale conditions as convective complex moved across eastern Nebraska in the early morning hours. An outflow boundary then moved southwest into northeast Kansas, through about Topeka to just east of Marysville. As southwesterly surface winds have strengthened through the day, they have worked to counter slightly reinforced outflow and push this boundary back to the north. Little progress was made on the east end, and appears as though the incoming upper shortwave evident on WV imagery will move across this boundary for the remainder of the afternoon and evening hours. While shear is not ideal, and high surface dewpoints not conducive for a high end wind threat, there is enough instability (2000-3000J/kg range) to consider hail and possibly locally heavy rainfall a threat if these storms develop and move through. Forecast is certainly probabilistic - GFS confines convection more east, as does the EC, although the EC is slower with its exit through the morning on Sunday. The HRRR and NAM extend area of convection farther westward from NE KS and drop cluster of precip south southeast across the area through the evening hours. Have played the forecast toward the latter, although kept coverage isolated in nature as it passes through. Can`t rule out a bust with precip, especially as you go west, but do think the far eastern counties will see hit and miss showers and thunderstorms as the evening goes on. Heat returns on Sunday as mid level temperatures climb under the shortwave ridge behind the departing shortwave trof. Have highs in the 90s with heat indices coming out in the 99-103 range as the dewpoints hold around 70 east to the 60s west...however western counties are hotter so in the end heat index differences are subtle at best. .LONG TERM...(Sunday Night through Saturday) Issued at 244 PM CDT SAT JUL 5 2014 By Sunday evening the cold front dips southward from central NE, straddling the KS and NE border near 00Z. The main upper trough positioned to our north and east at this time has given guidance lower confidence in precip developing near the weakly convergent frontal boundary until after midnight. Northern areas of the CWA have a slight chance for thunderstorms while most of the CWA remains dry. Monday afternoon will be another hot and humid day as the surface trough over western KS deepens, increasing southwesterly flow and mixing of warmer air aloft. Highs once again in the mid to upper 90s are likely with heat indices between 100 and 103 degrees. A more potent shortwave trough digs southward through the plains on Monday evening, shunting the cold front through the CWA by 18Z Tuesday. Showers and thunderstorms are likely across the Nebraska and northwest MO border, decreasing to a chance further south as the heavier precip bands follow the upper trough axis centered over central/northern MO. Wind shear through 6 KM increases overnight with the passing wave between 30 and 40 kts while MLCAPE is around 1500 J/KG. A few stronger storms cannot be ruled out, especially if they redevelop or are able to become sfc based in the afternoon. Winds shift back towards the south with another incoming upper wave expected Wednesday evening. Trends show the heavier precip bands to impact mainly north central and portions of central KS where highest pops were placed. Precipitation will wane as it lifts northeast through Thursday, replaced by temporary ridging on Friday. Saturday begins the unsettled pattern once again as northwest flow begins to bring another series of weak disturbances through the region. Highs behind the boundary Tuesday through Thursday will cool back to the 80s with lows in the upper 60s. Increased warm advection Friday and Saturday, raise temps once again to the 90s accompanied by lows in the 70s. && .AVIATION...(For the 06Z TAFs through 06Z Sunday Night) Issued at 1148 PM CDT SAT JUL 5 2014 Expect VFR conditions through Sunday. With high pressure over Gulf Coast and low pressure over western KS, expect southerly flow to continue. Winds on Sunday should be weaker/less gusty than those on Saturday. Cannot completely rule out an isolated thunderstorm in eastern KS the rest of tonight, but confidence is low and chances of occurring at FOE or TOP also low. Thus, have not added to TAF. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GDP SHORT TERM...67 LONG TERM...Bowen AVIATION...GDP
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1103 PM EDT Mon Jul 7 2014 ...Forecast Update... Issued at 1100 PM EDT Mom Jul 7 2014 The HRRR short range model has initialized the current convection across the area quite well. For the rest of this evening and the early morning hours expect mostly dry conditions once light rain across south central Kentucky dissipates by midnight. No new convection is expected until a fast moving storm complex now over northern Missouri moves into west central Kentucky and southern Indiana during the pre-dawn hours. Precipitation chances will, therefore ramp up again around dawn, especially for locations south of Interstate 64 and west of I - 65 .SHORT TERM (Now through Tuesday Night)... Issued at 308 PM EDT Mon Jul 7 2014 This afternoon a cold front extended from the Great Lakes through Illinois and Missouri to the Great Plains. Storms have fired ahead of this front, especially between Indianapolis and St Louis in an area of maximized deep moisture convergence and CAPE. These storms will slide to the ESE and will provide southern Indiana and northern sections of central Kentucky with scattered storms this evening. By the time the storms reach here they will likely begin to weaken, so any severe weather that might occur will be isolated. Locally heavy downpours and gusty winds will be the main threats. Tonight an MCS will advance from Kansas/Nebraska this evening into IL/IN/OH early Tuesday morning. The LMK CWA will be on the southern edge of this feature, with showers and a few thunderstorms possible in southern Indiana and northern Kentucky as we`re waking up Tuesday morning. Those showers/storms are not expected to be severe. By Tuesday afternoon a line of storms is expected to erupt in the vicinity of the Ohio River. The synoptic cold front, an outflow boundary from the morning MCS, and differential heating will all be possible triggers to get the storms going. We`ll also have an upper trof entering the picture from the northwest. Though instability is always in question when we have morning clouds and showers, we should become unstable enough by afternoon such that severe weather will be a threat. Soundings are increasingly showing dry air aloft and bowing echoes are possible, so strong gusty winds will be the main threat. Precipitable water amounts around 2 inches will lead to locally torrential downpours. Tuesday evening the line of strong/severe storms will proceed through central and southern Kentucky. The strongest storms will weakening and move out of the area overnight. Tonight will be muggy, though southwest breezes will keep up around 10 mph through the night to help it feel a little better outside. Lows will be around 70. High temperatures Tuesday will be highly dependent on cloud cover...will go with middle and upper 80s. Tuesday night we`ll see rain-cooled lows in the middle and upper 60s. .LONG TERM (Wednesday through Monday)... Issued at 245 PM EDT Mon Jul 7 2014 The synoptic pattern at the start of the long term period will feature rather amplified flow for mid July, with an amplified ridge across the western CONUS and an eastern trough centered over the Great Lakes region. This pattern will slowly deamplify through the long term period, allowing the heat and humidity to return this upcoming weekend after a brief reprieve this week. Wednesday will begin with a cold front pushing southeast of the region. The overall trend in numerical guidance with this front has continued to be quicker, thus think most will remain dry Wednesday as cooler/drier air filters into the region. The only exception may be across southern KY where their proximity to the front may allow for a few lingering showers/storms, mostly during the first part of the day. It will feel quite pleasant, as highs will only top out in the low to mid 80s with reduced humidity values. The pleasant conditions will continue Thursday into Friday as another 1020+ mb surface ridge settles over the region. This ridge will allow for highs in the low to mid 80s Thursday, pushing into the mid and upper 80s Friday. However, both days will still be seasonably pleasant as dewpoints will only be in the upper 50s to lower 60s. The forecast becomes a bit more murky this weekend, as guidance begins to diverge. The GFS is the most aggressive with building an upper-level ridge into the region, which would limit convective activity due to capping aloft. However, the GEM/Euro/GFS Ensemble are in better agreement that this ridge will remain more to the southwest, placing the region in the better northwesterly flow aloft making for a more active period. Will lean towards the more active solution, which brings chances for showers/storms beginning Friday night and lasting at least through the end of the long term period. Temperatures this weekend will be tough given the convective potential, but it will be muggier with highs in the upper 80s to lower 90s. && .AVIATION (00Z TAF Update)... Issued at 635 PM EDT Mon Jul 7 2014 Well...Ongoing convection over EVV to BMG pushing ese and pose a threat to the 3 terminal sites. Bow echo over EVV is heading towards BWG, that is if it holds together. DCAPE values of 1200 will keep the wind threat alive. EVV just measured 57 mph from line. For now have typed up draft WRKTAF will storms moving into SDF by 1z, BWG by 2z and LEX by 3z, but that is highly dependent on if the storms maintain their intensity and characteristics. Tuesday pre-dawn and into the morning daylight hours a large complex of thunderstorms will be advancing from the NE/IA/MO towards IL/IN/OH. SDF, and maybe LEX, will be positioned along the southern edge of this complex. Better storm chances will arrive at SDF Tuesday afternoon, when strong to severe storms will be possible. Winds will once again be gusty from the southwest. Tuesday afternoon event looks probable with high instability airmass with frontal boundary moving into it. The only negative is if too much cloud cover from morning convection persists, that would inhibit the deep convection. For now, have predominate showers around 18z and prob30 for tsra. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........JSD Short Term.....13 Long Term......KJD Aviation.......JDG
AREA FORECAST DISCUSSION
NWS CARIBOU ME
639 PM EDT SUN JUL 6 2014 .SYNOPSIS... A WEAK DISTURBANCE WILL MOVE ACROSS THE REGION TONIGHT. UNSETTLED CONDITIONS ARE THEN EXPECTED MONDAY THROUGH MID WEEK. && .NEAR TERM /THROUGH MONDAY/... 640 PM UPDATE...INCREASED THE RAIN CHANCES TO 60% FOR THE NORTHERN AREAS AS THE LATEST RADAR LOOP SHOWED AN AREA OF SHOWERS EXTENDING FROM WESTERN MAINE ESE INTO NE MAINE. THIS AREAS OF SHOWERS WAS DUE TO A DISTURBANCE MOVING ACROSS NORTH-CENTRAL MAINE AS SEEN ON THE LATEST WV SATELLITE LOOP. TEMPERATURES HAVE COOLED BACK INTO THE LOW TO MID 60S DUE TO THE CLOUDS AND SHOWERS WHILE S OF THE FRONT, READINGS WERE WELL INTO THE 70S. THE LATEST HRRR AND RUC BOTH MATCHED UP CLOSE W/THIS SETUP AND SHOWED SOME LIGHT SHOWER ACTIVITY EXTENDING FURTHER S INTO PORTIONS AND CENTRAL AND EASTERN AREAS. THEREFORE, ADDED A MENTION FOR A SHOWERS IN THESE AREAS THROUGH THE EVENING. THE FRONT IS FORECAST TO LIFT N OF THE AREA OVERNIGHT W/SHOWERS PULLING OUT OF THE AREA. PREVIOUS DISCUSSION... A WEAK DISTURBANCE MOVING ACROSS NORTHERN MAINE HAS BROUGHT MOSTLY CLOUDY SKIES TO THE NORTH. THIS WEAKER SYSTEM HAS ALSO BROUGHT SOME SHOWERS MAINLY ACROSS FAR NORTH AND NORTHWEST PORTIONS OF THE FORECAST AREA. THESE SHOWERS WILL SLOWLY DRIFT EAST TO SOUTHEAST ACROSS THE CENTRAL AND NORTHERN PARTS OF THE FORECAST AREA THIS AFTERNOON INTO TONIGHT. THIS HAS SUPPRESSED TEMPERATURES ACROSS THE NORTH WHILE THOSE ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA HAVE ENJOYED MORE SUNSHINE WITH PARTLY TO MOSTLY SUNNY SKIES AND WARMER TEMPERATURES. THIS DISTURBANCE WILL KEEP INCREASED SHOWER CHANCES ACROSS THE FAR NORTH TONIGHT WHILE SOUTHERN PORTIONS OF THE REGION ARE EXPECTED TO STAY DRY. A FRONTAL BOUNDARY WILL APPROACH THE REGION AS WE GO INTO MONDAY. THIS WILL BRING A INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS TO THE REGION AS WE GO INTO MONDAY AFTERNOON. BEST CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE ACROSS THE NORTHERN AND NORTHWESTERN PORTIONS OF THE FORECAST AREA. LOW TEMPERATURES ACROSS THE REGION TONIGHT ARE EXPECTED TO BE IN THE UPPER 50S TO LOWER 60S WITH HIGH TEMPERATURES MONDAY GENERALLY IN THE UPPER 70S TO LOWER 80S. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... A WEAKENING COLD FRONT/TROF WILL BEGIN TO CROSS THE REGION MONDAY NIGHT. EXPECT A WEAKENING AREA OF SHOWERS/THUNDERSTORMS TO MOVE SOUTH ACROSS THE FORECAST AREA MONDAY NIGHT. THE REMNANTS OF THIS BOUNDARY AND DIURNAL HEATING COULD PRODUCE A CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY. ANOTHER COLD FRONT WILL BEGIN TO CROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY...THOUGH THE EXACT TIMING OF THE FRONT IS STILL UNCERTAIN. EXPECT A CHANCE OF SHOWERS/THUNDERSTORMS WITH THIS FRONT...THOUGH THE EXTENT OF COVERAGE IS ALSO STILL UNCERTAIN DEPENDENT ON THE EVENTUAL TIMING OF THE FRONT. TEMPERATURES WILL BE AT SLIGHTLY ABOVE NORMAL LEVELS TUESDAY/WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A COLD FRONT EXITS MAINE WEDNESDAY NIGHT WITH SHOWERS COMING TO AN END. AN UPPER LEVEL TROUGH FILLS ON THURSDAY AND FRIDAY THEN GIVES WAY TO RIDGING FOR THE WEEKEND. DRY AND SLIGHTLY ABOVE NORMAL TEMPERATURES CAN BE EXPECTED. A SHORTWAVE TROUGH MOVES INTO THE NORTHEAST U.S. ON SUNDAY WITH A COLD FRONT SWEEPING ACROSS MAINE. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE WITH THE FRONTAL PASSAGE. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... NEAR TERM: SITES WILL STAY MOSTLY VFR WITH NORTHERN SITES GOING MVFR WITH DISTURBANCE AND SHOWERS MOVING ACROSS THE REGION TONIGHT. SOME SITES COULD BE REDUCED ONCE AGAIN ACROSS THE NORTH IN HEAVIER SHOWERS AND THUNDERSTORMS MONDAY. SHORT TERM: OCCASIONAL MVFR/IFR CONDITIONS WILL OCCUR ACROSS THE REGION MONDAY NIGHT WITH SHOWERS AND THUNDERSTORMS. GENERALLY VFR CONDITIONS ARE EXPECTED ACROSS THE REGION TUESDAY INTO THURSDAY AWAY FROM ANY SHOWERS OR THUNDERSTORMS...WITH VARIABLE CONDITIONS IN THE VICINITY OF SHOWERS OR THUNDERSTORMS. VFR CONDITIONS ARE EXPECTED FRIDAY. && .MARINE... NEAR TERM: NO HEADLINES HAVE BEEN ISSUED AT THIS POINT. HOWEVER SEAS ARE EXPECTED TO BUILD FROM 3 TO 5 FT TO 4 TO 6 FT LATER MONDAY DUE TO INCREASED SW FLOW. SHORT TERM: SMALL CRAFT ADVISORY LEVEL SEAS ARE POSSIBLE MONDAY NIGHT INTO WEDNESDAY NIGHT. VISIBILITIES COULD BE REDUCED AT TIMES IN SHOWERS MONDAY NIGHT INTO WEDNESDAY NIGHT. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT/JORDAN SHORT TERM...NORCROSS LONG TERM...OKULSKI AVIATION...HEWITT/JORDAN/NORCROSS MARINE...HEWITT/JORDAN/NORCROSS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
856 PM EDT MON JUL 7 2014 .SYNOPSIS... HIGH PRESSURE BECOMES ANCHORED OFF THE SOUTHEAST COAST TONIGHT THROUGH WEDNESDAY. A WEAK FRONTAL BOUNDARY APPROACHES FROM THE NORTHWEST LATER WEDNESDAY AND LINGERS OVER THE MID ATLANTIC REGION INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... LATEST WX ANALYSIS FEATURES SFC HIGH PRESSURE CENTERED WELL OFFSHORE...RIDGING BACK TOWARDS THE SOUTHEAST COAST. TO THE NW, LOW PRESSURE WAS ANALYZED OVER ONTARIO, WITH THE SFC COLD FRONT SNAKING SWWD BACK INTO THE MID MO VLY AND CENTRAL PLAINS. ALOFT, EARLY EVENING GOES WV IMAGERY SHOWS A STRONG SHORTWAVE EMBEDDED IN BROAD UPPER LEVEL TROUGH OVER AND N OF THE GREAT LAKES/UPPER MIDWEST. MEANWHILE, UPPER RIDGING PERSISTS IN THE SUBTROPICAL WESTERN ATLANTIC. NO MAJOR CHANGES NEEDED THIS EVENING. SCT TO BKN CU OF LATE THIS AFTN HAS LARGELY DISSIPATED AS EXPECTED EARLY THIS EVENING. GENERALLY CLEAR/MOSTLY CLEAR AND MILD OVERNIGHT WITH EARLY MORNING LOW TEMPERATURES TO AVERAGE IN THE LOW/MID 70S. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... THE UPPER RIDGE/SURFACE HIGH PRESSURE HOLD STRONG OFF THE COAST TUESDAY...WITH THE FRONT REMAINING WELL NW OF THE LOCAL AREA. THIS WILL RESULT IN DEEP LAYERED SSW FLOW AND HOT TEMPERATURES. HIGHS ARE EXPECTED TO AVERAGE IN THE MID/UPPER 90S...WITH ONLY FEW-SCT AFTERNOON CU. HUMIDITY VALUES WILL REMAIN MODEST AS AFTERNOON DEWPOINTS MIX DOWN INTO THE MID 60S. THIS WILL KEEP HEAT INDICES AOB 100. THERE IS NOT MUCH OF A TRIGGER FOR CONVECTION AND FORECAST SOUNDINGS INDICATE A RATHER PROMINENT SUBSIDENCE INVERSION THROUGH THE DAY. AN ISO TSTM COULD DRIFT OFF THE HIGHER TERRAIN INTO FAR N/NW PORTIONS OF THE AREA TUESDAY EVENING. OTHERWISE...EXPECT ANOTHER WARM NIGHT UNDER A MOSTLY CLEAR TO PARTLY CLOUDY SKY. LOWS SHOULD AVERAGE IN THE LOW/MID 70S. THE COLD FRONT CROSSES THE MOUNTAINS AND SLUMPS INTO THE AREA FROM THE WNW WEDNESDAY. THIS WILL INTERACT WITH THE HOT AND MODERATELY HUMID AIRMASS OVER THE PIEDMONT/COASTAL PLAIN BRINGING A 30-40% CHC OF SHOWERS/TSTMS MAINLY DURING THE AFTERNOON AND EVENING HOURS. AN FEW STRONG WIND GUSTS ARE POSSIBLE AS CONVECTION DEVELOPS OVER A DEEP WELL MIXED BOUNDARY LAYER. HOWEVER...WIDESPREAD SEVERE WEATHER IS NOT EXPECTED. HIGHS SHOULD BE IN THE LOW/MID 90S...AND ONCE AGAIN HUMIDITY LEVELS WILL BE LOW ENOUGH TO KEEP HEAT INDICES AOB 100. THE BOUNDARY LINGERS OVER THE REGION THURSDAY...WITH A 30-40% CHC OF MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS CONTINUING. HIGHS SHOULD DROP BACK INTO THE UPPER 80S TO AROUND 90...AFTER MORNING LOWS IN THE LOW/MID 70S. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... VERY WARM AND RATHER HUMID CONDITIONS WILL DOMINATE THE EXTENDED PERIOD. UPR TROF WILL APPROACH AND PUSH ACRS THE AREA THU NGT INTO SAT...NUDGING ONE FRNTL BOUNDARY EVENTUALLY OFF THE CST. ANOTHER FRONT WILL THEN PUSH INTO THE REGION MON AND MON NGT. WILL HAVE 40 POPS MAINLY OVR ERN/SE AREAS THU NGT INTO FRI...THEN DIMINISHING TO 30 OR 20 POPS FRI AFTN INTO SAT. INCREASE POPS TO 30 PERCENT EVERYWHERE FOR SUN AFTN/EVENG...DUE TO HIGHER TEMPS AND A LEE TROF SETTING UP OVR THE REGION. WILL HAVE 30 POPS AGAIN FOR MON AFTN THRU MON NGT...AS FRNTL BOUNDARY PUSHES INTO THE AREA. MIN TEMPS WILL RANGE FM THE MID 60S TO LWR 70S THRU THE PERIOD...WITH MAX TEMPS RANGING FM THE MID 80S TO LWR 90S. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... A RESPECTABLE PRESSURE GRADIENT FOR JULY WILL RESULT IN S-SW WINDS REMAINING BREEZY OVERNIGHT. GUSTY SW WINDS (18-23 KTS) DEVELOP ONCE AGAIN DURING THE DAY TUESDAY. ISOLATED CONVECTION MAINLY NORTHERN PORTIONS ARE PSBL TUESDAY AFTN AND EVENING. AS A COLD FRONT APPROACHES FROM THE NW WEDNESDAY AND SETTLES OVER THE REGION THURSDAY AND FRIDAY...THERE WILL BE A CHANCE FOR AFTN AND EVENING TSTMS WEDNESDAY THROUGH FRIDAY. A BIT DRIER PATTERN IS INDICATED SATURDAY. && .MARINE... 7 PM UPDATE... A SCA IS IN EFFECT THROUGH 10 AM TUESDAY FOR THE BAY AND THE LOWER JAMES RIVER. SW WINDS WILL OCCASIONALLY GUST TO AROUND 20 KNOTS OVER THESE WATERS. THE RAP AND HRRR AGAIN HOLD ONTO SUSTAINED WINDS OF NEAR 20 KNOTS THROUGH 12Z THEN DROP THEM OFF. THIS IS VERY SIMILAR TO MONDAY MORNING BUT NOT NECESSARILY A SIMILAR PATTERN. WINDS OVER LAND WERE GUSTY EARLY MONDAY EVENING AND SOME OF THESE GUSTS HAVE SPREAD INTO THE WRN PORTIONS OF THE WATERS. WITH THE HI RES MODELS INDICATING SCA CONDITIONS ONCE AGAIN...IT SEEMED PRUDENT TO ISSUE THE SCA. WILL ASSESS THE NEED FOR SCA IN CURRITUCK SOUND LATER THIS EVENING. FROM PREVIOUS DISCUSSION... SSW WINDS 10 TO 20 KT WILL CONTINUE TO DOMINATE THE WTRS TNGT THRU WED WITH SEAS 2 TO 4 FT OVR THE CSTL WTRS...ALTHO SEAS COULD REACH 5 OR 6 FT OVR THE NRN CSTL WTRS TUE NGT INTO WED. WAVES WILL RANGE FM 1 TO 3 FT. A COLD FRNT WILL SLOWLY DROP SE ACRS THE WTRS WED EVENG THRU FRI. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT TUESDAY FOR ANZ630>632- 634-638. && $$ SYNOPSIS...AJZ/ALB NEAR TERM...AJZ/MAM SHORT TERM...AJZ/ALB LONG TERM...TMG AVIATION...LSA MARINE...TMG/LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
745 PM EDT MON JUL 7 2014 .SYNOPSIS... HIGH PRESSURE BECOMES ANCHORED OFF THE SOUTHEAST COAST TONIGHT THROUGH WEDNESDAY. A WEAK FRONTAL BOUNDARY APPROACHES FROM THE NORTHWEST LATER WEDNESDAY AND LINGERS OVER THE MID ATLANTIC REGION INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... THE LATEST GOES WV IMAGERY SHOWS A BROAD TROUGH OVER AND N OF THE GREAT LAKES WITH A COLD FRONT TRAILING BACK THROUGH THE OHIO VALLEY. MEANWHILE...AN UPPER RIDGE IS ANCHORED OVER THE SUBTROPICAL WRN ATLANTIC. THIS PATTERN HAS CREATED SSW FLOW ACROSS THE MID ATLANTIC REGION RESULTING IS WARMING TEMPERATURES...BUT ONLY A MODEST RECOVERY OF DEWPOINTS AS UPSTREAM MOISTURE HAS BEEN SOMEWHAT LIMITED. AFTERNOON TEMPERATURES AVERAGE IN THE LOW/MID 90S...WITH DEWPOINTS IN THE LOW/MID 60S. AFTERNOON CU SHOULD DISSIPATE THIS EVENING FOLLOWED BY A CLEAR AND WARM NIGHT. LOW TEMPERATURES SHOULD AVERAGE IN THE LOW/MID 70S. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... THE UPPER RIDGE/SURFACE HIGH PRESSURE HOLD STRONG OFF THE COAST TUESDAY...WITH THE FRONT REMAINING WELL NW OF THE LOCAL AREA. THIS WILL RESULT IN DEEP LAYERED SSW FLOW AND HOT TEMPERATURES. HIGHS ARE EXPECTED TO AVERAGE IN THE MID/UPPER 90S...WITH ONLY FEW-SCT AFTERNOON CU. HUMIDITY VALUES WILL REMAIN MODEST AS AFTERNOON DEWPOINTS MIX DOWN INTO THE MID 60S. THIS WILL KEEP HEAT INDICES AOB 100. THERE IS NOT MUCH OF A TRIGGER FOR CONVECTION AND FORECAST SOUNDINGS INDICATE A RATHER PROMINENT SUBSIDENCE INVERSION THROUGH THE DAY. AN ISO TSTM COULD DRIFT OFF THE HIGHER TERRAIN INTO FAR N/NW PORTIONS OF THE AREA TUESDAY EVENING. OTHERWISE...EXPECT ANOTHER WARM NIGHT UNDER A MOSTLY CLEAR TO PARTLY CLOUDY SKY. LOWS SHOULD AVERAGE IN THE LOW/MID 70S. THE COLD FRONT CROSSES THE MOUNTAINS AND SLUMPS INTO THE AREA FROM THE WNW WEDNESDAY. THIS WILL INTERACT WITH THE HOT AND MODERATELY HUMID AIRMASS OVER THE PIEDMONT/COASTAL PLAIN BRINGING A 30-40% CHC OF SHOWERS/TSTMS MAINLY DURING THE AFTERNOON AND EVENING HOURS. AN FEW STRONG WIND GUSTS ARE POSSIBLE AS CONVECTION DEVELOPS OVER A DEEP WELL MIXED BOUNDARY LAYER. HOWEVER...WIDESPREAD SEVERE WEATHER IS NOT EXPECTED. HIGHS SHOULD BE IN THE LOW/MID 90S...AND ONCE AGAIN HUMIDITY LEVELS WILL BE LOW ENOUGH TO KEEP HEAT INDICES AOB 100. THE BOUNDARY LINGERS OVER THE REGION THURSDAY...WITH A 30-40% CHC OF MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS CONTINUING. HIGHS SHOULD DROP BACK INTO THE UPPER 80S TO AROUND 90...AFTER MORNING LOWS IN THE LOW/MID 70S. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... VERY WARM AND RATHER HUMID CONDITIONS WILL DOMINATE THE EXTENDED PERIOD. UPR TROF WILL APPROACH AND PUSH ACRS THE AREA THU NGT INTO SAT...NUDGING ONE FRNTL BOUNDARY EVENTUALLY OFF THE CST. ANOTHER FRONT WILL THEN PUSH INTO THE REGION MON AND MON NGT. WILL HAVE 40 POPS MAINLY OVR ERN/SE AREAS THU NGT INTO FRI...THEN DIMINISHING TO 30 OR 20 POPS FRI AFTN INTO SAT. INCREASE POPS TO 30 PERCENT EVERYWHERE FOR SUN AFTN/EVENG...DUE TO HIGHER TEMPS AND A LEE TROF SETTING UP OVR THE REGION. WILL HAVE 30 POPS AGAIN FOR MON AFTN THRU MON NGT...AS FRNTL BOUNDARY PUSHES INTO THE AREA. MIN TEMPS WILL RANGE FM THE MID 60S TO LWR 70S THRU THE PERIOD...WITH MAX TEMPS RANGING FM THE MID 80S TO LWR 90S. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... A RESPECTABLE PRESSURE GRADIENT FOR JULY WILL RESULT IN S-SW WINDS REMAINING BREEZY OVERNIGHT. GUSTY SW WINDS (18-23 KTS) DEVELOP ONCE AGAIN DURING THE DAY TUESDAY. ISOLATED CONVECTION MAINLY NORTHERN PORTIONS ARE PSBL TUESDAY AFTN AND EVENING. AS A COLD FRONT APPROACHES FROM THE NW WEDNESDAY AND SETTLES OVER THE REGION THURSDAY AND FRIDAY...THERE WILL BE A CHANCE FOR AFTN AND EVENING TSTMS WEDNESDAY THROUGH FRIDAY. A BIT DRIER PATTERN IS INDICATED SATURDAY. && .MARINE... 7 PM UPDATE... A SCA IS IN EFFECT THROUGH 10 AM TUESDAY FOR THE BAY AND THE LOWER JAMES RIVER. SW WINDS WILL OCCASIONALLY GUST TO AROUND 20 KNOTS OVER THESE WATERS. THE RAP AND HRRR AGAIN HOLD ONTO SUSTAINED WINDS OF NEAR 20 KNOTS THROUGH 12Z THEN DROP THEM OFF. THIS IS VERY SIMILAR TO MONDAY MORNING BUT NOT NECESSARILY A SIMILAR PATTERN. WINDS OVER LAND WERE GUSTY EARLY MONDAY EVENING AND SOME OF THESE GUSTS HAVE SPREAD INTO THE WRN PORTIONS OF THE WATERS. WITH THE HI RES MODELS INDICATING SCA CONDITIONS ONCE AGAIN...IT SEEMED PRUDENT TO ISSUE THE SCA. WILL ASSESS THE NEED FOR SCA IN CURRITUCK SOUND LATER THIS EVENING. FROM PREVIOUS DISCUSSION... SSW WINDS 10 TO 20 KT WILL CONTINUE TO DOMINATE THE WTRS TNGT THRU WED WITH SEAS 2 TO 4 FT OVR THE CSTL WTRS...ALTHO SEAS COULD REACH 5 OR 6 FT OVR THE NRN CSTL WTRS TUE NGT INTO WED. WAVES WILL RANGE FM 1 TO 3 FT. A COLD FRNT WILL SLOWLY DROP SE ACRS THE WTRS WED EVENG THRU FRI. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT TUESDAY FOR ANZ630>632- 634-638. && $$ SYNOPSIS...AJZ/ALB NEAR TERM...AJZ/ALB SHORT TERM...AJZ/ALB LONG TERM...TMG AVIATION...LSA MARINE...TMG/LSA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
703 PM EDT MON JUL 7 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 413 PM EDT MON JUL 7 2014 WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW BETWEEN A RIDGE OVER THE WRN CONUS AND SRN PLAINS AND A TROUGH THROUGH NRN MANITOBA INTO NRN ONTARIO. ONE WEAK SHRTWV IN CNTRL MN SUPORTED SCT SHRA/TSRA FROM ERN MN INTO CNTRL WI...WHILE A MORE PROMINENT SHRTWV WAS LOCATED OVER WRN NORTH DAKOTA. AT THE SFC...GUSTY WNW WINDS PREVAILED WITH A 995 MB LOW PRES OVER NRN ONTARIO(NEAR CYTS). TONIGHT...THE HIGHER RES MODELS HAVE TRENDED FARTHER SOUTH WITH THE THE HEAVIER PCPN AND ASSOCIATED PCPN CHANCES WHERE THE GREATER FORCING(700-300 MB QVECTOR CONV AND UPPER LEVEL DIV) AND INSTABILITY IS LOCATED AS THE ND SHRTWV MOVES TOWARD THE AREA. NEVERTHELESS...NMS SHRA ARE EXPECTED TO CLOSER TO THE WI BORDER BY LATE EVENING AND OVERNIGHT WITH CHANCE POPS FARTHER NORTH TOWARD LAKE SUPERIOR EAST OF THE KEWEENAW. THUNDER WAS ALSO ONLY INDCLUDED ACROSS THE FAR SOUTH. TUESDAY...EXPECT THAT HIGHER PCPN CHANCES IN THE MORNING TO DIMINISH BY AFTERNOON AS THE SHRTWV MOVES OFF TO THE EAST. ADDITIONAL PCPN AMOUNTS SHOULD AGAIN BE GREATEST OVER SRN CWA. THE COMBINATION OF THICKER CLOUDS AND NRLY LOW LEVEL FLOW WILL KEEP TEMPS WELL BELOW NORMAL WITH UPPER 50S TO MID 60S NORTH TO THE MID 60S SOUTH. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 416 PM EDT MON JUL 7 2014 AN UPPER TROUGH CURRENTLY OVER THE UPPER GREAT LAKES REGION WILL BE REINFORCED TONIGHT AND TOMORROW BY A SHORTWAVE (CURRENTLY NEAR LAKE WINNIPEG) THAT WILL DROP SOUTHEAST THROUGH THE AREA. THIS FIRST WAVE WILL SHIFT OUT OF THE AREA ON TUESDAY...BUT ANOTHER WAVE WILL BE DROPPING SOUTHEAST FROM LAKE WINNIPEG AT 00Z WEDNESDAY AND ACROSS THE CWA LATE TUESDAY EVENING THROUGH WEDNESDAY MORNING. THERE ARE SOME DIFFERENCES IN THE MODELS WITH THE TRACK OF THE SHORTWAVE...WITH THE GENERAL CONSENSUS OF IT MOVING ACROSS THE SOUTHWEST HALF OF THE CWA. WILL TRANSITION CHANCE POPS ACROSS THE WESTERN TWO THIRDS OF THE AREA FROM NORTHWEST TO SOUTHEAST DURING THAT TIME. THERE IS LIMITED CAPE...BUT THE STRENGTH OF THE SHORTWAVE AND POCKET OF STEEPER LAPSE RATES (700-500MB AT 6-6.5C/KM) THOUGHT THERE COULD BE AN ISOLATED RUMBLE OF THUNDER AND HAVE SHOWN SLIGHT CHANCE OVER THE SOUTHWEST HALF OF THE CWA AS IT SWEEPS THROUGH. BEHIND THIS WAVE...HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES REGION FOR WEDNESDAY AFTERNOON AND REMAIN THROUGH THURSDAY NIGHT. 850MB TEMPS ARE COOLING TO 6-7C ON WEDNESDAY...AND COMBINED WITH MORNING CLOUDS/RAIN AND NORTHERLY WINDS OFF LAKE SUPERIOR...IT WILL LEAD TO A BELOW NORMAL DAY ACROSS THE U.P. EXPECT MOST LOCATIONS TO SEE HIGHS IN THE 60S...WITH COOLER VALUES EAST NEAR LAKE SUPERIOR AND MAYBE REACHING 70 NEAR THE WISCONSIN BORDER WITH SOME AFTERNOON SUNSHINE. CLEAR SKIES...LIGHT WINDS...AND PWATS AROUND 45 PERCENT OF NORMAL UNDER THE HIGH MOVING THROUGH SHOULD LEAD TO A COOL NIGHT OVER SOME OF THE INTERIOR COLD SPOTS WEDNESDAY NIGHT. HAVE LOWERED INTERIOR TEMPERATURES TOWARDS THE LOW END OF GUIDANCE AND HAVE A FEW LOCATIONS RIGHT AROUND 40. EXPECT TEMPERATURES TO TREND BACK TOWARDS NORMAL ON THURSDAY WITH ABUNDANT SUNSHINE AND INTO THE LOW-MID 70S OVER INTERIOR LOCATIONS. WITH LAKE BREEZES EXPECTED ON THURSDAY...WILL SEE COOLER TEMPERATURES OVER THE EAST NEAR LAKE SUPERIOR/MICHIGAN. THE NORTHWEST FLOW ALOFT WILL GIVE WAY DURING THIS PERIOD...AS THE NEXT WAVE ROUNDING THE UPPER RIDGE OVER THE PACIFIC NORTHWEST AND AFFECTS THE AREA FOR FRIDAY AND FRIDAY NIGHT. THAT NEXT WAVE WILL PUSH A LOW EAST ACROSS NORTHERN MANITOBA...WITH A COLD FRONT STRETCHING SOUTH INTO THE UPPER MISSISSIPPI VALLEY FRIDAY MORNING. A SHORTWAVE SLIDING EAST OUT OF THE DAKOTAS FRIDAY MORNING WILL LEAD TO SHOWERS/THUNDERSTORMS DEVELOPING AHEAD OF THE COLD FRONT AND MOVING FROM WEST TO EAST THROUGH THE CWA FRIDAY INTO FRIDAY NIGHT. WILL SHOW INCREASING CHANCES DURING THAT PERIOD AND THEN DIMINISHING LATE IN THE NIGHT AND INTO THE NEXT MORNING. DIURNAL HEATING OUT AHEAD OF THE FRONT ON FRIDAY AFTERNOON SHOULD LEAD TO SOME THUNDERSTORMS OVER THE AREA FRIDAY AFTERNOON/EVENING. DETERMINISTIC MODELS VARY BEHIND THIS WAVE/FRONT WITH THE HANDLING OF THE UPPER TROUGH...BUT THE LASTEST TREND IS FOR IT TO AMPLIFY OVER THE UPPER GREAT LAKES FOR THE SECOND HALF OF THE WEEKEND AND INTO NEXT WEEK. THIS WOULD LEAD TO A COOLER THAN NORMAL PERIOD THROUGH AT LEAST THE FIRST HALF OF NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 703 PM EDT MON JUL 7 2014 VFR CONDITIONS WILL CONTINUE AT ALL SITES THROUGH THIS EVENING. THE NEXT DISTURBANCE AND LOW PRESSURE TROUGH WILL MOVE INTO THE REGION AND BRING INCREASING MID CLOUDS AND A CHANCE OF SHOWERS AT IWD THIS EVENING AND OVERNIGHT AT KCMX AND KSAW. AS WINDS SHIFT NE LATE TONIGHT LOOK FOR MVFR CLOUDS TO DEVELOP AT KIWD DROPPING TO IFR TUE MORNING BEFORE DRIER AIR MOVES IN AND VFR CONDITIONS RETURN BY MID TUE AFTERNOON. MVFR CONDITIONS ARE ALSO EXPECTED AT KSAW AND CMX BY TUE MORNING. THERE IS LOWER CONFIDENCE WITH THE RAIN COVERAGE AND INTENSITY THAT COULD HELP DROP CIGS TO IFR AT BOTH SITES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 413 PM EDT MON JUL 7 2014 WINDS ARE EXPECTED TO BE BELOW 25KTS THROUGH THE PERIOD OUTSIDE OF ANY STRONG SHOWERS OR THUNDERSTORMS. LOW PRESSURE NE OF LAKE SUPERIOR WILL LIFT TOWARD JAMES BAY THIS EVENING AS A WEAK LOW PRESSURE TROUGH MOVES ACROSS LAKE SUPERIOR AND UPPER MI TONIGHT. ANOTHER WEAK LOW PRESSURE TROUGH ACROSS ONTARIO TUESDAY WILL SINK ACROSS LAKE SUPERIOR TUESDAY NIGHT INTO EARLY WEDNESDAY...BEFORE STRONGER HIGH PRESSURE SETTLES ACROSS THE UPPER GREAT LAKES WEDNESDAY NIGHT THROUGH AT LEAST THURSDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
427 PM EDT SUN JUL 6 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 426 PM EDT SUN JUL 6 2014 WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW DOWNSTREAM FROM A RIDGE OVER THE ROCKIES AND WRN PLAINS. A PROMINENT SHORTWAVE TROUGH EXTENDED FROM NW ONTARIO TO WRN LAKE SUPERIOR. A COLD FRONT EXTENDED INTO NE MN FROM LOW PRESSURE NEAR CYPL. EXTENSIVE CLOUDS COVER OVER THE REGION HAS INHIBITED DIABATIC HEATING AND KEPT MLCAPE VALUES IN THE 500-1000 J/KG RANGE OVER MAINLY THE WRN THIRD OF UPPER MI. AN AREA OF SHRA/TSRA OVER NE WI NEAR TO IMT AND NEAR MNM WAS SUPPORTED BY WEAK TO MODERATE 700-300 MB QVECTOR CONV AND 30 KNOT WSW 850-750 INFLOW PUSHING MUCAPE VALUES TO 1K J/KG. ADDITIONAL STRONG TSRA WERE LOCATED OVER NE MN WERE LOCATED NEAR THE COLD FRONT. LATE THIS AFTERNOON INTO TONIGHT...WITH SOME LATE AFTERNOON CLEARING OVER WRN UPPER MI...ADDITIONAL HEATING MAY BOOST MLCAPE VALUES INTO THE 1000-1500 J/KG RANGE. AS THE COLD FRONT SWEEPS INTO THE AREA BTWN 21Z-24Z...SCT/NMRS TSRA ARE EXPECTED TO DEVELOP THAT COULD BE STRONG TO SEVERE...SUPPORTED BY 0-6KM SHEAR VALUES IN THE 35-40 KNOT RANGE. THE SHRA/TSRA WILL THEN SHIFT INTO THE ERN CWA BTWN 00Z-03Z AND END OVER THE CNTRL CWA...AS THE COLD FRONT ADVANCES. EXPECT CLEARING OVERNIGHT AS SUBSIDENCE AND DRIER AIR MOVE IN FROM THE WEST. MONDAY...EXPECT DRY AND BREEZY CONDITIONS WITH TEMPERATURES CLIMBING TO NEAR SEASONAL NORMALS IN THE MID 70S TO AROUND 80. A SLIGHT CHANCE FOR SHRA/TSRA WAS INCLUDED OVER THE FAR SW CWA AS A WEAK SHRTWV NEAR THE AREA IN CYCLONIC MID LEVEL FLOW AROUND THE TROUGH OVER NRN MANITOBA AND NRN ONTARIO. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 337 PM EDT SUN JUL 6 2014 A SHORTWAVE TROUGH WILL MOVE NEAR OR OVER THE CWA MON NIGHT INTO TUE MORNING...WITH TYPICAL MODEL DISAGREEMENT ON MAGNITUDE AND PATH OF THE SHORTWAVE AND ASSOCIATED CONVECTION. THERE IS SOME MODEL CONSENSUS THAT THE SHORTWAVE WILL BE ALONG OR S/SW OF THE WRN AND SRN PORTIONS OF THE CWA...SO HAVE CONTINUED TO FAVOR THESE LOCATIONS FOR THE BEST POPS MON NIGHT INTO TUE MORNING. CONTINUED TO ONLY HAVE CHANCE POPS DUE TO LIMITED MOISTURE. ANOTHER SHORTWAVE DIVES ACROSS OR NEAR THE CWA TUE AFTERNOON/EVENING...BUT MOISTURE WILL BE EVEN MORE LIMITED THAN WITH THE PREVIOUS SHORTWAVE...SO CONTINUED THE FORECAST OF EVEN LOWER POPS /SLIGHT CHANCE TO LOW END CHANCE/ DURING THIS TIME. YET ANOTHER SHORTWAVE LOOKS TO MOVE THROUGH LATE TUE NIGHT INTO WED. MOISTURE CONTINUES TO BE MORE LIMITED WITH TIME...SO ONLY HAVE SLIGHT CHANCE POPS DURING THIS PERIOD. NO PRECIPITATION EXPECTED FROM WED NIGHT THROUGH MUCH OF FRI AS UPPER RIDGING BUILDS OVER THE REGION. AFTER RELATIVELY COOL WEATHER TUE AND WED WITH HIGHS IN THE 60S TO LOW 70S...THE RIDGE WILL BRING A WARMING TREND AS HIGH TEMPS CLIMB INTO THE UPPER 70S /OR EVEN THE LOW 80S/ INLAND ON FRI. MODELS SHOW A TROUGH MOVING THROUGH THE REGION LATE FRI THROUGH SAT...WHICH WOULD LEAD TO SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA. SUN COULD SEE SOME PRECIP IF THE ECMWF FORECAST VERIFIES IN BRINGING A SHORTWAVE NEAR THE CWA...BUT THE GFS HAS A DRY FORECAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 154 PM EDT SUN JUL 6 2014 SOME EARLY AFTERNOON LOW CLOUDS AT SAW WILL GIVE WAY TO MVFR CIGS WITH MID CLOUDS THIS AFTERNOON. THE APPROACH OF A COLD FRONT AND DISTURBANCE IS EXPECTED TO PRODUCE SCT/NMRS SHRA/TSRA BY MID AFTERNOON OVER WRN UPPER MI AND LATE THIS AFTERNOON INTO CNTRL UPPER MI. SOME STRONGER STORMS WITH GUSTY WINDS AND HAIL MAY BE POSSIBLE. HOWEVER...WITH UNCERTAINTY WITH THE COVERAGE/POSITION...ONLY VCTS WAS MENTIONED. BEHIND THE FRONT...DRY ADVECTION WILL BRING IMPROVEMENT TO VFR CONDITIONS THIS EVENING. GUSTY WNW WINDS WILL DEVELOP LATE TONIGHT AT CMX AND MON MORNING AT IWD/SAW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 406 AM EDT SUN JUL 6 2014 FOG WILL CONTINUE ACROSS LAKE SUPERIOR INTO MONDAY. WINDS ARE EXPECTED TO BE BELOW 25KTS THROUGH THE PERIOD /OUTSIDE OF ANY STRONG SHOWERS OR THUNDERSTORMS/. LOW PRESSURE ACROSS N MINNESOTA AND W ONTARIO WILL DEEPEN SLIGHTLY OVER CENTRAL ONTARIO AND N LAKE SUPERIOR THIS EVENING...BEFORE MOVING ACROSS QUEBEC ON MONDAY. BRIEF HIGH PRESSURE WILL SLIDE ACROSS LAKE SUPERIOR MONDAY NIGHT...AS WEAK LOW PRESSURE PUSHES ACROSS LAKE MICHIGAN AND LAKE HURON ON TUESDAY. ANOTHER WEAK LOW ACROSS ONTARIO TUESDAY NIGHT IS EXPECTED TO SINK ACROSS LAKE SUPERIOR ON WEDNESDAY...BEFORE STRONGER HIGH PRESSURE SETTLES ACROSS THE UPPER GREAT LAKES WEDNESDAY NIGHT THROUGH AT LEAST THURSDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TITUS AVIATION...JLB MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
409 AM EDT SUN JUL 6 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 424 PM EDT SAT JUL 5 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE FROM THE SW CONUS INTO THE NRN PLAINS AND A DOWNSTREAM WNW FLOW THROUGH THE NRN GREAT LAKES. A WEAK SHORTWAVE TROUGH OVER NW ONTARIO(NW OF LAKE SUPERIOR) COMBINED WITH 25-30 KNOT 850-750 MB INFLOW OF MODERATELY UNSTABLE AIR (MUCAPE VALUES OF 1000-1500 J/KG) AND 40 KNOT 0-6KM SHEAR SUPPORTED STRONG CONVECTION OVER NE MN AND ADJOINING PORTION OF ONTARIO. SOME SHRA/TSRA WERE ALSO SLIDING INTO LAKE SUPERIOR BUT WERE WEAKENING AS THE CONVECTION MOVED AWAY FROM THE MORE UNSTABLE AIR. OTHERWISE...SUNSHINE AND SSW FLOW WAA PUSHED TEMPS INTO THE UPPER 70S AND LOWER 80S. TONIGHT...EXPECT THAT THE ONGOING SHRA/TSRA INTO WRN LAKE SUPERIOR WILL CONTINUE TO WEAKEN AS THEY SLIDE TO THE EAST THROUGH THE NRN HALF OF LAKE SUPERIOR...PER RADAR TRENDS AND SHORT RANG HIGH RES MODELS. ADDITIONAL CONVECTION IS LIKELY TO DEVELOP UPSTREAM LATE THIS EVENING AS ANOTHER WEAK SHRTWV OVER SRN MANITOBA MOVES TOWARD THE AREA. HOWEVER...UNCERTAINTY IS MUCH HIGHER WITH THE POSSIBILITY OF MCS DEVELOPMENT AND ITS EVENTUAL TRACK. EXPECT THAT THE HIGHER SHRA/TSRA WILL REMAIN TO THE NORTH AND WEST OF UPPER MI BUT THAT SOME MAY MOVE INTO UPPER MI...ESPECIALLY AFTER 06Z. WITH ONLY LIMITED MUCAPE INTO THE 500-1000 J/KG RANGE...ANY TSTORMS SHOULD REMAIN BELOW SEVERE LIMITS. SUNDAY...THE BEST CHANCE FOR SHRA/TSRA IS EXPECTED DURING THE AFTERNOON AS A STRONGER SHRTWV AND COLD FRONT MOVE TOWARD THE AREA. THERE WILL BE A CONDITIONAL RISK FOR STRONG/SEVERE STORMS THAT DEPENDS ON THE AMOUNT OF THICKER CLOUDS THAT LINGER INTO THE AFTERNOON. IF ENOUGH CLEARING DEVELOPS FOR A FEW HOURS TO ALLOW TEMPS TO REBOUND INTO THE LOWER 80S(DEWPOINTS IN THE MID TO UPPER 60S)...MLCAPE VALUES INTO THE 1K-2K RANGE COMBINED WITH 0-6KM SHEAR OF 35-40 KNOTS WILL SUPPORT STRONG/SEVERE ORGANIZED STORMS. 0-1KM HELICITY/SHAPE IS ALSO FAVORABLE FOR SOME ROTATING STORMS/SUPERCELLS. IF MORE PROMINENT CLOUDS REMAIN INTO THE AFTERNOON...THE GREATER INSTABILITY AND SEVERE POTENTIAL WOULD BE MAINLY OVER WI AND POSSIBLY INTO THE FAR SRN CWA. NMRS SHRA/TSRA OVER CNTRL UPPER MI DURING THE AFTERNOON WILL SHIFT TOWARD THE S AND ERN CWA BY LATE AFTERNOON AND EVENING. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 406 AM EDT SUN JUL 6 2014 COOLER AND DRIER AIR WILL SLOWLY TAKE OVER ON MONDAY. A SECONDARY COLD FRONT INITIALLY STRETCHING FROM THE LOW NEARING THE ONTARIO/QUEBEC BORDER THROUGH THE N MN BORDER AT 12Z MONDAY WILL SLOWLY EDGE E...AS HIGH PRESSURE WEAK HIGH PRESSURE BUILDS IN. DESPITE HIGH PRESSURE SETTLING ACROSS UPPER MICHIGAN MONDAY NIGHT...THE 500MB TROUGH WILL LINGER...AND CONTINUE TO BRING ABOUT SEVERAL SMALL DISTURBANCES. UNSETTLED WEATHER...WITH OFF AND ON LIGHT SHOWERS WILL REMAIN POSSIBLE OVER MAINLY WESTERN UPPER MICHIGAN FOR THE FIRST HALF OF THE WORK WEEK. TEMPS IN THE 60S TO MID 70S WILL BE COMMON...WHICH IS BELOW NORMAL. MONDAY NIGHT INTO EARLY TUESDAY LOOKS TO BE THE BEST CHANCE OF SEEING PRECIPITATION.... CURRENTLY HAVE AROUND A QUARTER OF AN INCH GOING...BUT SOME GUIDANCE WAS INDICATING THE POTENTIAL FOR QUITE A BIT MORE OVER THE S HALF OF UPPER MI /CLOSER TO THE SFC LOW BRUSHING THE CWA/. ONLY EXPECTING A SLIGHT CHANCE OF THUNDERSTORMS...WITH A BETTER CHANCE WELL TO OUR S. ANOTHER LOW PRESSURE SYSTEM OVER FAR N ONTARIO TUESDAY AFTERNOON WILL SINK OVER N LAKE SUPERIOR TUESDAY NIGHT INTO WEDNESDAY...ALTHOUGH THE 06/00Z GFS IS AN OUTLIER AND DOESN/T REALLY HAVE THIS FEATURE AT THE SFC IT STILL HAS THE MAIN 500MB TROUGH DIVING IN ALOFT. DUE TO LIMITED MOISTURE...POPS WHERE KEPT IN THE CHANCE OR BELOW RANGE. AT THIS TIME...DRY HIGH PRESSURE IS EXPECTED TO SETTLE ACROSS THE UPPER GREAT LAKES REGION AT THE SFC AND ALOFT WEDNESDAY NIGHT THROUGH FRIDAY. THERE ARE SOME DISCREPANCIES TO THE 500MB TROUGH...AND HOW QUICKLY IT EXITS E. THE ECMWF IS THE QUICKEST TO BRING BACK RIDGING AT 500MB...WITH THE CANADIAN SOLUTION KEEPING A TROUGH ACROSS THE E HALF OF THE CWA INTO FRIDAY. A BLENDED SOLUTION LOOKS REASONABLE FOR THURSDAY AFTERNOON ON. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 130 AM EDT SUN JUL 6 2014 VFR CONDITIONS WILL CONTINUE FOR MOST OF THIS PERIOD. SOME SHOWERS ARE ALSO EXPECTED TO DEVELOP AND MOVE INTO THE CWA ON SUNDAY AND WHEN THEY DO...MVFR CONDITIONS ARE POSSIBLE WITH THE SHOWERS STARTING FIRST AT IWD AND LAST AT SAW. CONDITIONS SHOULD IMPROVE BACK TO VFR BY LATE SUN AFTERNOON AS A COLD FRONT MOVES THROUGH THE AREA. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 406 AM EDT SUN JUL 6 2014 FOG WILL CONTINUE ACROSS LAKE SUPERIOR INTO MONDAY. WINDS ARE EXPECTED TO BE BELOW 25KTS THROUGH THE PERIOD /OUTSIDE OF ANY STRONG SHOWERS OR THUNDERSTORMS/. LOW PRESSURE ACROSS N MINNESOTA AND W ONTARIO WILL DEEPEN SLIGHTLY OVER CENTRAL ONTARIO AND N LAKE SUPERIOR THIS EVENING...BEFORE MOVING ACROSS QUEBEC ON MONDAY. BRIEF HIGH PRESSURE WILL SLIDE ACROSS LAKE SUPERIOR MONDAY NIGHT...AS WEAK LOW PRESSURE PUSHES ACROSS LAKE MICHIGAN AND LAKE HURON ON TUESDAY. ANOTHER WEAK LOW ACROSS ONTARIO TUESDAY NIGHT IS EXPECTED TO SINK ACROSS LAKE SUPERIOR ON WEDNESDAY...BEFORE STRONGER HIGH PRESSURE SETTLES ACROSS THE UPPER GREAT LAKES WEDNESDAY NIGHT THROUGH AT LEAST THURSDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...KF AVIATION...07 MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
131 AM EDT SUN JUL 6 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 424 PM EDT SAT JUL 5 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE FROM THE SW CONUS INTO THE NRN PLAINS AND A DOWNSTREAM WNW FLOW THROUGH THE NRN GREAT LAKES. A WEAK SHORTWAVE TROUGH OVER NW ONTARIO(NW OF LAKE SUPERIOR) COMBINED WITH 25-30 KNOT 850-750 MB INFLOW OF MODERATELY UNSTABLE AIR (MUCAPE VALUES OF 1000-1500 J/KG) AND 40 KNOT 0-6KM SHEAR SUPPORTED STRONG CONVECTION OVER NE MN AND ADJOINING PORTION OF ONTARIO. SOME SHRA/TSRA WERE ALSO SLIDING INTO LAKE SUPERIOR BUT WERE WEAKENING AS THE CONVECTION MOVED AWAY FROM THE MORE UNSTABLE AIR. OTHERWISE...SUNSHINE AND SSW FLOW WAA PUSHED TEMPS INTO THE UPPER 70S AND LOWER 80S. TONIGHT...EXPECT THAT THE ONGOING SHRA/TSRA INTO WRN LAKE SUPERIOR WILL CONTINUE TO WEAKEN AS THEY SLIDE TO THE EAST THROUGH THE NRN HALF OF LAKE SUPERIOR...PER RADAR TRENDS AND SHORT RANG HIGH RES MODELS. ADDITIONAL CONVECTION IS LIKELY TO DEVELOP UPSTREAM LATE THIS EVENING AS ANOTHER WEAK SHRTWV OVER SRN MANITOBA MOVES TOWARD THE AREA. HOWEVER...UNCERTAINTY IS MUCH HIGHER WITH THE POSSIBILITY OF MCS DEVELOPMENT AND ITS EVENTUAL TRACK. EXPECT THAT THE HIGHER SHRA/TSRA WILL REMAIN TO THE NORTH AND WEST OF UPPER MI BUT THAT SOME MAY MOVE INTO UPPER MI...ESPECIALLY AFTER 06Z. WITH ONLY LIMITED MUCAPE INTO THE 500-1000 J/KG RANGE...ANY TSTORMS SHOULD REMAIN BELOW SEVERE LIMITS. SUNDAY...THE BEST CHANCE FOR SHRA/TSRA IS EXPECTED DURING THE AFTERNOON AS A STRONGER SHRTWV AND COLD FRONT MOVE TOWARD THE AREA. THERE WILL BE A CONDITIONAL RISK FOR STRONG/SEVERE STORMS THAT DEPENDS ON THE AMOUNT OF THICKER CLOUDS THAT LINGER INTO THE AFTERNOON. IF ENOUGH CLEARING DEVELOPS FOR A FEW HOURS TO ALLOW TEMPS TO REBOUND INTO THE LOWER 80S(DEWPOINTS IN THE MID TO UPPER 60S)...MLCAPE VALUES INTO THE 1K-2K RANGE COMBINED WITH 0-6KM SHEAR OF 35-40 KNOTS WILL SUPPORT STRONG/SEVERE ORGANIZED STORMS. 0-1KM HELICITY/SHAPE IS ALSO FAVORABLE FOR SOME ROTATING STORMS/SUPERCELLS. IF MORE PROMINENT CLOUDS REMAIN INTO THE AFTERNOON...THE GREATER INSTABILITY AND SEVERE POTENTIAL WOULD BE MAINLY OVER WI AND POSSIBLY INTO THE FAR SRN CWA. NMRS SHRA/TSRA OVER CNTRL UPPER MI DURING THE AFTERNOON WILL SHIFT TOWARD THE S AND ERN CWA BY LATE AFTERNOON AND EVENING. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 330 PM EDT SAT JUL 5 2014 A SHORTWAVE TROUGH ALOFT AND SFC LOW WILL BE JUST N OF THE CWA WITH A COLD FRONT ACROSS THE CENTRAL CWA AT 00Z MON. CONVECTION...POSSIBLY SEVERE /SEE SHORT TERM DISCUSSION FOR MORE DETAILS ON SEVERE THREAT/...WILL BE ONGOING ALONG AND AHEAD OF THE FRONT OVER MAINLY THE ERN HALF OF THE CWA. BY 06Z MON...THE FRONT WILL HAVE MOVED TO THE ERN CWA...WITH MOST OF THE CONVECTION E OF THE CWA. ADDITIONAL SHORTWAVE ENERGY LOOKS TO MOVE N OF THE CWA DURING THE DAY ON MON...BUT FORCING WILL STAY N KEEPING THE CWA DRY FOR THE MOST PART. THE NAM IS SHOWING A SHORTWAVE MOVING IN MON EVENING...WHICH WOULD RESULT IN PRECIP LATE IN THE DAY OVER THE WRN CWA...BUT MOST OTHER MODELS SHOW THIS COMING IN MON NIGHT OR EVEN EARLY TUE. AS IS USUAL WITH SUBTLE SHORTWAVES AND ASSOCIATED CONVECTIVE COMPLEXES...CONFIDENCE IN EXACT DETAILS IS QUITE LOW THIS FAR OUT. CONFIDENCE CONTINUES TO BE LOW THROUGH THE MIDDLE OF THE WEEK AS MODELS INDICATE ADDITIONAL SHORTWAVE ENERGY MON NIGHT OR TUE...WHICH APPEARS TO STAY S OF THE CWA. YET ANOTHER SHORTWAVE IS MODELED TO MOVE OVER THE NRN CWA TUE NIGHT...BUT WITH LESS MOISTURE TO WORK WITH...PRECIP SHOULD BE CONFINED TO NEAR THE SHORTWAVE. WITH THE GENERAL TROUGHING OVER THE REGION THROUGH MIDWEEK...EXPECT TEMPS TO BE A LITTLE BELOW NORMAL. HOWEVER...UPPER RIDGING BUILDING INTO THE REGION LATER IN THE WEEK AND POSSIBLY INTO NEXT WEEKEND WILL LEAD TO AN ABOVE NORMAL TREND FOR TEMPERATURES. CONFIDENCE IS LOW THAT ANY SIGNIFICANT PRECIP WILL OCCUR THU THROUGH NEXT SAT...BUT THE BEST CHANCES FOR PRECIP WILL BE ON SAT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 130 AM EDT SUN JUL 6 2014 VFR CONDITIONS WILL CONTINUE FOR MOST OF THIS PERIOD. SOME SHOWERS ARE ALSO EXPECTED TO DEVELOP AND MOVE INTO THE CWA ON SUNDAY AND WHEN THEY DO...MVFR CONDITIONS ARE POSSIBLE WITH THE SHOWERS STARTING FIRST AT IWD AND LAST AT SAW. CONDITIONS SHOULD IMPROVE BACK TO VFR BY LATE SUN AFTERNOON AS A COLD FRONT MOVES THROUGH THE AREA. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 424 PM EDT SAT JUL 5 2014 HIGH PRESSURE ACROSS THE OHIO VALLEY WILL CONTINUE TO SLOWLY EXIT EASTWARD THROUGH SUNDAY. LOOK FOR THE RIDGE ACROSS UPPER MICHIGAN TO WEAKEN AS LOW PRESSURE NEAR S MANITOBA SUNDAY MORNING SLIDES ACROSS ONTARIO AND LAKE SUPERIOR SUNDAY AFTERNOON AND EVENING. THIS LOW WILL DEEPEN SW OF JAMES BAY LATE SUNDAY NIGHT AND MONDAY MORNING...WHILE DRAGGING A TROUGH AVERAGING ACROSS LAKE SUPERIOR. A WEAK TROUGH WILL REMAIN DRAPED ACROSS NORTHERN AND SOUTHEAST ONTARIO THROUGH WEDNESDAY A RIDGE BUILDS OVER THE NORTHERN HIGH PLAINS. WINDS SHOULD REMAIN AT OR BELOW 20 KNOTS...EXCEPT IN OR NEAR ANY STRONGER THUNDERSTORMS. FOG...POSSIBLY DENSE...WILL BE POSSIBLE FROM LATE TONIGHT THROUGH EARLY MONDAY MORNING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TITUS AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
352 PM CDT SUN JUL 6 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 328 PM CDT SUN JUL 6 2014 COLD FRONT HAS BEEN MAKING STEADY PROGRESS TO THE EAST AT ABOUT 20 KTS ACROSS MN TODAY...AND AT 3PM WAS IN THE PROCESS OF WORKING ACROSS THE TWIN CITIES. MORNING CLOUDS SLOWED DOWN THE WARMING IN THE TWIN CITIES...BUT THERE IS STILL HOPE FOR OUR FIRST 90 DEGREE TEMP THIS YEAR AS THERE WILL BE ABOUT A 2 HOUR WINDOW WHERE WE CAN STILL WARM BEHIND THE FRONT BEFORE THE CAA KICKS IN. WE HAVE SEEN PLACES LIKE REDWOOD FALLS...GLENCOE...AND NEW ULM HIT 90 IN THIS ZONE AND IT WILL BE HITTING THE TWIN CITIES STILL DURING PEAK HEATING BETWEEN 3 AND 5 PM...SO DON/T GIVE UP HOPE ON THAT FIRST 90 JUST YET! AS FOR STORM POTENTIAL...ACTIVITY OVER WI HAS BEEN ELEVATED...WITH THE ATMO STILL CAPPED WITH RESPECT TO SFC BASED CONVECTION PER THE STABLE CU FIELD /AT 230 PM/ STILL IN PLACE OVER WHAT IS A VERY JUICY WARM SECTOR...WHERE DEWPS HAVE BEEN COMMONLY RISEN UP INTO THE MID 70S. STILL LOTS OF DISAGREEMENT WITH WHETHER OR NOT THIS FRONT WILL EVEN GENERATE CONVECTION...BUT GIVEN THE DEGREE OF INSTABILITY PRESENT...ALONG WITH THE SHORTWAVE MOVING INTO WRN MN AS EVIDENCED BY DRYING ON WATER VAPOR BACK ACROSS THE DAKOTAS...PREFER THE IDEA THE HRRR AND MEMBER1 OF THE 15Z HOPWRF SHOW WITH A SCT LINE OF STORMS DEVELOPING ALONG THE FRONT AROUND 20Z AND QUICKLY SPREADING EAST. THIS WOULD PLACE THE THUNDER THREAT MAINLY ALONG AND EAST OF AN ALBERT LEA TO RICE LAKE LINE. SFC WINDS HAVE VEERED CONSIDERABLY DURING THE DAY...WHICH WILL RESULT IN A MINIMAL TORNADO THREAT...BUT 2K-4K J/KG OF MLCAPE...H7-H5 LAPSE RATES UP OVER 7 DEG C/KM...AND EFFECTIVE SHEAR AROUND 40 KTS WILL BE MORE THAN ENOUGH TO SUPPORT A WIND/HAIL THREAT...ESPECIALLY TOWARD THE IOWA BORDER WHERE INSTABILITY AND LAPSE RATES ARE BETTER. WILL SEE SKIES CLEAR OUT TONIGHT...BUT CONSISTENT NW WINDS WILL BRING IN DEWPS IN THE LOWER/MID 60S...WHICH WILL LIMIT THE FOG POTENTIAL. IN ADDITION...A VERY POTENT SHORTWAVE CURRENTLY OVER NRN SASKATCHEWAN WILL DROP INTO NODAK TONIGHT...WITH ACTIVITY EXPECTED TO DEVELOP OVER CENTRAL NODAK THIS EVENING. THIS WILL LIKELY SEND SHOWERS/STORMS TOWARD CENTRAL MN LATE TONIGHT INTO MONDAY MORNING...THOUGH MORE ROBUST STORM COVERAGE OVER THE MPX CWA IS NOT EXPECTED UNTIL MONDAY AFTERNOON AS THAT STRONG SASKATCHEWAN WAVE MOVES INTO WRN MN. FOR THIS WAVE...PREFERRED A GEM/ECMWF/GFS BLEND FOR ITS TIMING. THE NAM IS ABOUT 6 HOURS FASTER WITH THE WAVE...PLACING IT OVER ERN MN BY THE END OF THE SHORT TERM AS OPPOSED TO WRN MN AS THE OTHER GUIDANCE SHOWS. DETERMINISTIC MODELS SHOW FAIRLY WIDESPREAD CONVECTION DEVELOPING BASED ON THEIR QPF FIELDS...BUT THE CAMS SHOW ACTIVITY BEING NOTICEABLY MORE SCATTERED OVER MN MONDAY AFTERNOON. THIS IS LIKELY DUE TO THE FACT THAT THERE REALLY IS NO STRONG SFC FEATURE TO FOCUS ACTIVITY DURING THE AFTERNOON...SO THE CAMS ARE SIMPLY GENERATING CONVECTION WHERE THEY CAN DEVELOP ENOUGH INSTABILITY. THOUGH NW FLOW IS EXPECTED...1.5-2.5K J/KG OF MLCAPE COMBINED WITH 50-60 KTS OF BULK SHEAR WILL BE MORE THAN ENOUGH TO SUPPORT A SEVERE THREAT. HODOGRAPHS FOR MONDAY ARE MOSTLY LONG STRAIGHT LINES...INDICATING THE MAIN THREAT WOULD BE LARGE HAIL FROM SPLITTING SUPERCELLS. IF ENOUGH STORMS CAN INITIATE...WE WOULD LIKELY END UP WITH A COMPLEX OF STORMS OR TWO THAT WOULD HAVE A WIND TREAT AS WELL. HIGHER LCLS /DUE TO THE DRIER BOUNDARY LAYER AIR EXPECTED/ ALONG WITH THE SHEAR BEING MAINLY OF THE SPEED VARIETY /WITH LITTLE DIRECTION CHANGE/ WILL GREATLY LIMIT ANY TORNADO THREAT. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 328 PM CDT SUN JUL 6 2014 WHILE THE BEST STORM COVERAGE SHOULD GENERALLY BE BETWEEN 21-00Z IN WESTERN MN...EASTERN MN WILL HAVE THE BEST SHOT AT THUNDER BETWEEN 00-03Z...AND SHORTLY THEREAFTER IN WESTERN WI. THE MID- LEVEL DRYING ARRIVES QUICKLY BETWEEN 03-06Z IN THE EASTERN FORECAST AREA...SO THE PRECIP SHOULD GET QUICKLY SHUFFLED OFF TO THE EAST LATE TOMORROW EVENING. DRIER AND SLIGHTLY COOLER AIR ARRIVES BEHIND THE STORM SYSTEM ON TUESDAY WITH SURFACE HIGH PRESSURE EXPANDING INTO THE PLAINS AND UPPER LEVEL NORTHWEST FLOW. NORTHWEST WINDS WILL BE A LITTLE BREEZY...OTHERWISE EXPECT MOSTLY SUNNY SKIES AND MILD TEMPERATURES IN THE 70S TO NEAR 80 DEGREES. UPPER LEVEL RIDGING FLATTENS AS IT SHIFTS INTO THE HIGH PLAINS ON WEDNESDAY...HOWEVER WITH RETURN FLOW DEVELOPING IN WESTERN MN IN THE AFTERNOON HIGH TEMPERATURES WILL IMPROVE A FEW DEGREES. THE EAST WILL REMAIN ON THE FRINGE OF AN 850MN COLD POCKET CENTERED ROUGHLY OVER LAKE SUPERIOR. MID AND HIGH CLOUDS BUILDING INTO THE AREA FROM THE WEST. MODEL CONSISTENCY ISN`T AS GOOD LATER IN THE WEEK WITH WEST TO NORTHWEST UPPER FLOW AND THE POSSIBILITY OF A FEW WEAK WAVES TO TRACK THROUGH THE AREA. THE TIMING OF THESE WAVES REMAIN TOO DIFFICULT TO PINPOINT WITH EACH MODEL SHOWING SLIGHTLY DIFFERENT TIMING AND LATITUDINAL PLACEMENT - DID NOT REALLY ALTER THE POPS MUCH WEDNESDAY NIGHT AND BEYOND. TEMPERATURES ARE EXPECTED TO REMAIN WITHIN A FEW DEGREES OF CLIMATE NORMALS DURING THE PERIOD. AFTER MONDAY...THE NEXT SUBSTANTIAL PROBABILITY FOR PRECIP ARRIVES ON THURSDAY WHEN THE FLOW BECOMES A LITTLE MORE W-SW AND WARM ADVECTION ARRIVES FROM THE DAKOTAS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1243 PM CDT SUN JUL 6 2014 COLD FRONT MAKING STEADY PROGRESS ACROSS MN THIS AFTERNOON AND AT 18Z STRETCHED FROM ABOUT MILLE LACS LAKE DOWN TO WORTHINGTON...SO JUST ABOUT READY TO MOVE INTO THE WRN TWIN CITIES METRO AREA. SCT STORMS OVER WRN WI ARE ELEVATED...WITH SFC BASED STORMS EXPECTED TO DEVELOP ALONG THE COLD FRONT AROUND 20Z. BY THEN THE FRONT WILL LIKELY BE JUST CLEARING MSP AND NEARING RNH...SO STILL LOOKS LIKE FIELD WITH BEST CHANCE FOR TS WITH THE FROPA THIS AFTERNOON IS EAU...WHERE A VCTS WAS MAINTAINED...BUT SHIFTED AN HOUR LATER TO BETWEEN 21Z AND 23Z. TONIGHT IS EXPECTED TO BE QUIET...WITH VFR CONDS AND WNW-NW WINDS PREVAILING. OVERNIGHT...STORMS ARE EXPECTED TO DEVELOP OVER CENTRAL NODAK...WITH REMNANTS OF THAT ACTIVITY LIKELY DRIFTING INTO CENTRAL MN LATE TONIGHT/EARLY MON MORNING. CONFIDENCE ON HOW THIS POTENTIAL ACTIVITY WILL EVOLVE IS LOW...SO STUCK WITH NOTHING MORE THAN A VCSH TOWARD THE END OF THE AXN/STC TAFS. MORE ROBUST TSRA ACTIVITY ACROSS THE MPX AREA IS EXPECTED AFTER 18Z MON AS A STRONG SHORTWAVE COMES OUT OF THE DAKOTAS. KMSP...LOOKS LIKE SFC BASED CONVECTION ALONG THE COLD FRONT WILL START TO DEVELOP JUST AS THE FRONT IS CLEARING MSP...SO ACTIVITY THIS AFTERNOON WILL REMAIN EAST OF THE FIELD. NEXT CHANCE FOR PRECIP WOULD COME BETWEEN 12Z AND 16Z MON MORNING AND THAT WOULD BE ASSOCIATED WITH ANY REMNANTS OF STORMS THAT ARE EXPECTED TO DEVELOP OVER NODAK TONIGHT. AT THIS POINT...SPREAD IN MODELS IS HIGH ENOUGH TO KEEP ANY PRECIP MENTION OUT OF THE TAF MON MORNING. BETTER TSRA CHANCES EXPECTED MON AFTERNOON AS A STRONG SHORTWAVE MOVES INTO WRN MN. FAVORED THE TIMING OF THE GFS/ECMWF/GEM WITH A SLOWER PROGRESSION OF THE WAVE AND RESULTANT SLOWER ARRIVAL OF AFTERNOON ACTIVITY THAN WHAT THE NAM HAS. ONCE THESE PESKY LOW CLOUDS CLEAR OUT TODAY...CONFIDENCE IS HIGH IN REST OF TAF BEING VFR OUTSIDE OF ANY PRECIP. /OUTLOOK FOR KMSP/ TUE...VFR. WIND NW 10 TO 20 KT. WED...VFR. WIND NW 5 TO 15 KT. THU...VFR. CHC TSRA OVERNIGHT. WIND S 10 TO 15 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...CLF AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1215 AM CDT SUN JUL 6 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 105 PM CDT SAT JUL 5 2014 LOOKS LIKE ANOTHER NIGHT WITH SOME POTENTIAL FOR SHRA/TSRA ACROSS THE REGION... BUT ONCE AGAIN THE QUESTION IS WHETHER THAT POTENTIAL WILL BE REALIZED. WE SHOULD SEE STORMS DEVELOP TO OUR WEST ONCE AGAIN THIS AFTERNOON... WHICH WILL LIKELY GROW UP SCALE INTO AN MCS. IF THIS OCCURS OVER NORTH DAKOTA AS MOST OF THE MODELS GUIDANCE SUGGESTS... IT LOOKS LIKE THE BULK OF IT WOULD TRANSLATE EAST ALONG THE THICKNESS CONTOURS AND MISS US TO THE NORTH. THERE ARE SOME HINTS IN THE CAM SOLUTIONS THAT A SECOND COMPLEX COULD DEVELOP FARTHER SOUTH OVER SOUTH DAKOTA... BUT IF THAT WERE TO OCCUR IT WOULD LIKELY TRANSLATE MORE SOUTHEASTWARD AND MISS US TO THE SOUTHWEST/SOUTH. A THIRD POTENTIAL FOR STORMS WOULD ACTUALLY BE SOONER... DURING LATE AFTERNOON/EARLY EVENING OVER OUR NORTH CENTRAL AND NORTHEAST CWFA... IF ANYTHING MANAGES TO DEVELOP IN THE CU FIELD CURRENTLY IN PLACE SOUTH OF THE ONGOING CONVECTION OVER NORTHEAST MINNESOTA. A COUPLE OF HOPWRF MEMBERS HAVE SUGGESTED THAT IS POSSIBLE... BUT THE OTHER MEMBERS AS WELL AS THE HRRR KEEP ANY OF THAT NORTH OF THE AREA. SO... OVERALL THERE REMAINS SOME POTENTIAL FOR ACTIVITY TO DEVELOP AND/OR MOVE INTO PORTIONS OF THE AREA TONIGHT... BUT IT IS BY NO MEANS A SLAM DUNK. WILL ALLOW POPS TO INCREASE ACROSS THE NORTH SOME DURING THE EVENING AND OVERNIGHT HOURS... WITH THAT AREA LOOKING TO HAVE THE BEST POTENTIAL TO SEE SOMETHING. ANYTHING THAT/S OVER THE AREA LATE TONIGHT WOULD SHIFT EAST IN THE MORNING... SO TRANSLATED SOME CHANCE POPS EASTWARD. WE WOULD THEN NEED TO LOOK TOWARD DEVELOPING ALONG/AHEAD OF THE COLD FRONT... WHICH WILL MOVE ACROSS THE AREA DURING THE LATE MORNING AND EARLY AFTERNOON ACCORDING TO THE MAJORITY OF THE GUIDANCE. THAT TIMING IS NOT PARTICULARLY FAVORABLE FOR DEVELOPMENT ACROSS OUR AREA... AND WOULD MAINLY POINT TOWARD AREAS EAST OF I-35 HAVING A CHANCE OF SEEING SOMETHING DURING THE AFTERNOON. SO... PUT THE HIGHEST POPS ON SUNDAY AFTERNOON ACROSS THE EASTERN PORTION OF THE AREA. SHOULD STORMS DEVELOP OVER THE AREA ON SUNDAY... THEY WOULD CERTAINLY HAVE SOME POTENTIAL TO BE SEVERE GIVEN MLCAPE VALUES AOA 2500 J/KG AND 0-6KM SHEAR AOA 35 KT... SO IT CERTAINLY BEARS WATCHING AND WILL BE MORE OF A CONCERN SHOULD THE FRONTAL TIMING WIND UP SLOWER. WE WILL MAKE A RUN AT 90 ON SUNDAY DEPENDING UPON HOW MUCH CLOUD COVER WE SEE OVER THE AREA... WHICH COULD BE HIGHLY VARIABLE DEPENDING ON ANY ISSUES FROM OVERNIGHT CONVECTIVE DEBRIS AND SHRA/TSRA DEVELOPMENT DURING THE DAY. THE FAIRLY EARLY FROPA DOESN/T APPEAR TO HAVE MUCH OF AN IMPACT ON THE HIGH TEMPERATURE POTENTIAL... WITH MIXING ACTUALLY LOOKING TO INCREASE BEHIND THE FRONT WHILE TEMPERATURES ALOFT ARE STILL SUPPORTIVE OF HIGHS NEAR 90. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 105 PM CDT SAT JUL 5 2014 THE THUNDERSTORM AND SEVERE WEATHER POTENTIAL SHOULD BE SOUTH AND EAST OF THE FORECAST AREA BY SUNDAY NIGHT ALONG THE AFOREMENTIONED COLD FRONT. GOOD MID-LEVEL DRYING WILL ACCOMPANY THE COLD ADVECTION SUNDAY NIGHT...BUT THE DRYING SHOULD BE SHORT LIVED WITH A WAVE DROPPING SOUTH OUT OF MANITOBA AND INTO ND/MN BY MONDAY AFTERNOON. A BIT MID DECK OF STRATUS OR STRATO-CU MIGHT ACT TO SUPPRESS SBCAPE...BUT THERE SHOULD BE DECENT RECOVERY IN ELEVATED INSTABILITY BY MONDAY AFTERNOON WITH STEEPENING MID-LEVEL LAPSE RATES. A MID-LEVEL SPEED MAX IS ALSO EXPECTED TO DROP SOUTH OUT OF THE HIGH PLAINS AND SHOULD INCREASE THE DEEP LAYER SHEAR ACROSS AT LEAST THE WESTERN FORECAST AREA. THEREFORE...STORMS EMBEDDED IN THE NORTHWEST FLOW SHOULD POSE A HAIL THREAT. WOULD NOT BE SURPRISED TO SEE THE SPC SLIGHT RISK SHIFTED A LITTLE FARTHER NORTH WITH THE NEXT UPDATE. WE HAVE INCREASED THE POPS TO 30-50% ACROSS MUCH OF THE FORECAST AREA...WITH THE IDEA OF AT LEAST SCATTERED STORM COVERAGE WITH THE ADVANCING SHORTWAVE AS THE TRIGGER. THE BEST TIME FRAME FOR STRONG TO SEVERE STORMS WOULD BE IN THE VERY LATE AFTERNOON AND EVENING. CYCLONICALLY CURVED LONG WAVE PATTERN LINGERS THROUGHOUT AT LEAST MID WEEK. THIS SHOULD CONTINUE TO REINFORCE THE COOL EARLY START TO THIS JULY...WHICH SITS BETWEEN 4 AND 7 DEGREES BELOW NORMAL FOR THE FIRST FEW DAYS IN CENTRAL MN AND WEST CENTRAL WI. HEIGHTS BUILD LATE IN THE WEEK...BUT THE FLOW STILL REMAINS W-NW AND THE THERMAL RIDGE OUT ACROSS THE WESTERN CONUS AND HIGH PLAINS WILL STRUGGLE TO ADVANCE EAST. THIS IS SUPPORTED BY THE CFS...05.12Z GFS/ECMWF AND THEIR CORRESPONDING ENSEMBLE MEMBERS WHICH INDICATES A NEAR NORMAL TEMPERATURE...BUT OVERALL DRY PATTERN FOR AT LEAST THE NEXT COUPLE WEEKS LOCALLY. IT DOES MEAN IF WE DONT REACH 90 TOMORROW...IT MAY BE SOME TIME BEFORE WE GET CLOSE TO THAT AGAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1159 PM CDT SAT JUL 5 2014 LOW CIGS AND VSBYS ARE IN PLACE AT TAF ISSUANCE TIME OVER NRN IA INTO SERN MN AND WRN WI. EAU AND RNH WILL BE MVFR OR IFR THROUGH TONIGHT INTO SUNDAY MORNING...BUT THERE WILL BE SOME BUILDING OF THIS TO THE NORTHWEST AS WELL...SO MSP IS NOT OUT OF THE WOODS EITHER...ALBEIT IT IS MORE UNCERTAIN THERE. TOUGH TO SAY HOW LOW VISIBILITIES MAY GET WITH THE LOW CLOUDS AND PERSISTENT SOUTHERLY FLOW IN PLACE BUT SEVERAL OBS IN NRN IA ARE LESS THAN 3SM AND IN SOME CASES LESS THAN 1SM. CONDITIONS SHOULD IMPROVE AFTER 14-15Z. THUNDERSTORMS TONIGHT HAVE BEEN CONFINED TO NORTHERN MN. A FEW CELLS MAY WORK DOWN TOWARD AXN OR STC DURING THE NEXT FEW HOURS...BUT THEY WOULD BE ENCOUNTERING A LESS FAVORABLE ENVIRONMENT. THUS...REMOVED MENTION OF TS FROM THE TAFS. BETTER CHANCE OF TS WILL COME EARLY SUNDAY AFTERNOON ACROSS WRN WI. KMSP...THERE WAS A BRIEF INSTANCE OF MVFR CIGS LATE THIS EVENING... HOWEVER THE CIGS HAVE RETREATED BACK TOWARD WI. THINKING THEY WILL BUILD NORTHWEST AGAIN OVERNIGHT BUT THE TERMINAL SHOULD BE ON THE NORTHWEST PERIPHERY. THUS...FELT MOST COMFORTABLE WITH TEMPOS AT THIS POINT. /OUTLOOK FOR KMSP/ MONDAY...VFR. WEST WIND 5 TO 15 KT. TUESDAY...VFR. NORTHWEST WIND 10 TO 20 KT. WEDNESDAY...VFR. WEST WIND 5 TO 10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...TRH LONG TERM...CLF AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
304 PM CDT Sun Jul 6 2014 .SHORT TERM: (Through Late Tonight) Issued at 302 PM CDT Sun Jul 6 2014 (Tonight) Still expect thunderstorms to redevelop along the cold front where MLCAPES are 5000+ J/kg across Iowa. These storms should move southeast into the northern half of the CWA during the late evening and overnight hours as both the NAM/GFS are in good agreement that shortwave trough currently over the upper Midwest will move in sync with the cold front across the CWA tonight. Latest runs of HRRR are showing that storms will dissipate before reaching the CWA, but the amount of forcing and instability warrant keeping at least the chance pops already going in the forecast. The simulated reflectivity of the explicit runs of the WRF show a line of storms moving southward across the entire CWA between 02-08Z. Also can`t rule out a few severe thunderstorms later this evening given the amount of instability and deep layer shear forecast to be around 30kts. Britt .LONG TERM: (Monday through Next Sunday) Issued at 302 PM CDT Sun Jul 6 2014 (Monday and Tuesday) Main concern will be the potential for a few severe thunderstorms on Monday afternoon and night. GFS and NAM both show that upper flow will be west northwesterly on Monday with the front becoming stalled by midday across the central part of the CWA. Temperatures in the lower to middle 90s and dewpoints in the 70s will cause the atmosphere to become very unstable under 7+C/km mid level lapse rates. Scattered thunderstorms may develop along the front as the CINH erodes during the day. Couldn`t rule out that any storms that develop Monday afternoon would be severe because of the amount of the instability. Thunderstorms will be more likely on Monday night when a shortwave trough moves southeast through the upper flow. A complex of thunderstorms will likely move southeast through the area along the front. This complex may be severe given deep layer sheer 40+ kts and produce locally heavy rainfall rates given precipitable waters over 2 inches. Damaging winds appear to be the primary threat...though large hail and isolated tornadoes are also possible. By Tuesday the cold front will still be over the south part of the CWA during the early afternoon hours. There may still be some chance for a few severe thunderstorms along the front as they initiate before the it moves south of the CWA by 00Z. (Wednesday through next Sunday) GFS and ECMWF still show that the cold front will extend from the Mid South back into the central Plains Wednesday and Thursday leaving us dry. 850mb temps are progged to be in the 12-16C range with southeasterly winds from the retreating surface high which will bring us below normal temperatures. The front will begin to move north as a warm front Friday into Saturday which will increase temperatures and thunderstorm chances. The GFS and ECMWF both show a cold front dropping southeastward in northwest flow by next Sunday, so will keep the chance of rain going into the latter half of next weekend. Britt && .AVIATION: (For the 18z TAFs through 18z Monday Afternoon) Issued at 1235 PM CDT Sun Jul 6 2014 Another tricky forecast when it comes to convective trends this forecast period. Activity from this morning has all but diminished across the area, however, a disturbance that will move through the region this afternoon could initiate some diurnal showers/thunderstorms that could impact metro area TAF sites. Given uncertainties in timing and the exact location of any storms that develop, have maintained VCTS mention for KSTL, KSUS, and KCPS this afternoon. A front to the north of the area will sag southward overnight tonight, with showers and thunderstorms expected to impact KUIN by 06Z. Uncertainty remains regarding how far south any nocturnal activity will make it, though models indicate at least some light precipitation across central and eastern Missouri by daybreak. Thus, have mentioned VCSH for KCOU and metro TAF sites in the 09-13Z time frame, though this trend will likely need revisited in future TAF issuances. Otherwise, VFR conditions will prevail outside of any storms, with winds gradually veering more southwesterly through the period. Specifics for KSTL: Currently expect VFR conditions to prevail through the forecast period. There is quite a bit of uncertainty regarding convective trends, with the possibility of diurnal shower/thunderstorm development later this afternoon. Have maintained the VCTS mention from 21-00Z, as the timing and exact location of any storms cannot be pinned down at this time. The other concern is that of precipitation that could impact the terminal after roughly 09Z tonight, associated with a cold front that will slowly sag into northern Missouri overnight. While it appears a bulk of the precipitation would remain north of KSTL, models are indicating at least some light precipitation by daybreak, hence have included VCSH mention from 09-13Z. This will likely need refined in future TAF issuances. Otherwise, southwesterly winds will continue to slowly veer, becoming west-southwesterly by the end of the period. JP && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1235 PM CDT Sun Jul 6 2014 .UPDATE... Issued at 1043 AM CDT SUN JUL 6 2014 Appears HRRR had the best handle on the progress of the MCS remnants up to the present as stratiform showers and scattered convection have descended into southwest Missouri. Warming depicted by IR satellite though would suggest a general decrease in lift across the region associated with a dampening shortwave. Forecast update maintains southward moving precipitation through late morning...becoming more scattered in association with remnant MCV this afternoon. High temperatures have been reduced at least a category across all regions due to cloud cover though do anticipate some recovery in the west as sunshine resumes and south winds pick back up this afternoon. && .SHORT TERM...(Today and Monday) Issued at 310 AM CDT SUN JUL 6 2014 Thunderstorms have developed across north central Missouri to the southwest into southeastern Kansas early this morning. This activity has developed on the nose of a low level jet a ahead of a weak upper level disturbance that is tracking south through the region. This activity will continue to develop and track to the south this morning and will mainly affect locations along an northwest of an Anderson to Bolivar to Vichy Missouri line this morning. This activity will weaken and dissipate by the mid morning hours with the strongest activity generally occurring before sunrise this morning. A few strong storms will be possible early this morning with hail to the size of pennies the main risk mainly before 7 AM this morning then storms should generally weaken as the morning moves a long. A warmer and more humid air mass is spreading north into the region and highs will top out in the upper 80s to the lower 90s this afternoon with heat index values in the middle 90s to near the 100 degree mark. Isolated storms could develop mainly east of Highway 65 this afternoon, but some capping is not expected to completely erode and there will not be much in the way of forcing in place. Therefore, this activity will be very isolated, if it can develop at all, and most locations will remain dry. If storms are able to develop this afternoon, instability will increase in excess of 2000J/kg of ML Cape and this instability and theta-E differences greater than 25K would support a localized downburst wind risk with a few of the storms that can develop. Hot and humid conditions will occur again Monday as highs top out in the lower to middle 90s with heat index values in the upper 90s to around 100 degrees. An unstable air mass will once again be over the area, and with the heating of the day the cap should weaken enough for scattered storms to develop Monday afternoon. Theta-E differences greater than 25K combined with the unstably air mass will once again support a risk for localized damaging straight line winds with a few of the stronger storms Monday afternoon. .LONG TERM...(Monday Night through Saturday) Issued at 310 AM CDT SUN JUL 6 2014 An upper level trough will move out of the northern Plains on Monday night and southeast into the region on Tuesday along with a weak cold front. Storms are expected to develop along the front as it pushes south through the area. There will be a risk for strong to severe storms Tuesday afternoon given a moist and unstable air mass along with an increase in deep layer shear with the approach of the upper level trough. Hail to the size of quarters and winds in excess of 60 mph will be the main risks with this activity. Slightly cooler conditions will occur on Wednesday and Thursday behind the front with highs in the middle to upper 80s. An upper level ridge will begin to build towards the region by late in the week sending the front back to the north. A few storms may develop on Thursday and Friday as the front moves north. Warmer conditions are then expected this weekend as highs warm back into the 90s. && .AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon) Issued at 1230 PM CDT SUN JUL 6 2014 Cluster of SHRA with embedded TSRA already impacting KJLN and KSGF to spread into the KBBG region this afternoon. Current activity to diminish in coverage as shortwave weakens and departs region. Ceilings to clear northwest to southeast during the afternoon...with KBBG clearing this evening. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ UPDATE...Runnels SHORT TERM...RUNNELS LONG TERM...Wise AVIATION...RUNNELS
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1044 AM CDT Sun Jul 6 2014 .UPDATE... Issued at 1043 AM CDT SUN JUL 6 2014 Appears HRRR had the best handle on the progress of the MCS remnants up to the present as stratiform showers and scattered convection have descended into southwest Missouri. Warming depicted by IR satellite though would suggest a general decrease in lift across the region associated with a dampening shortwave. Forecast update maintains southward moving precipitation through late morning...becoming more scattered in association with remnant MCV this afternoon. High temperatures have been reduced at least a category across all regions due to cloud cover though do anticipate some recovery in the west as sunshine resumes and south winds pick back up this afternoon. && .SHORT TERM...(Today and Monday) Issued at 310 AM CDT SUN JUL 6 2014 Thunderstorms have developed across north central Missouri to the southwest into southeastern Kansas early this morning. This activity has developed on the nose of a low level jet a ahead of a weak upper level disturbance that is tracking south through the region. This activity will continue to develop and track to the south this morning and will mainly affect locations along an northwest of an Anderson to Bolivar to Vichy Missouri line this morning. This activity will weaken and dissipate by the mid morning hours with the strongest activity generally occurring before sunrise this morning. A few strong storms will be possible early this morning with hail to the size of pennies the main risk mainly before 7 AM this morning then storms should generally weaken as the morning moves a long. A warmer and more humid air mass is spreading north into the region and highs will top out in the upper 80s to the lower 90s this afternoon with heat index values in the middle 90s to near the 100 degree mark. Isolated storms could develop mainly east of Highway 65 this afternoon, but some capping is not expected to completely erode and there will not be much in the way of forcing in place. Therefore, this activity will be very isolated, if it can develop at all, and most locations will remain dry. If storms are able to develop this afternoon, instability will increase in excess of 2000J/kg of ML Cape and this instability and theta-E differences greater than 25K would support a localized downburst wind risk with a few of the storms that can develop. Hot and humid conditions will occur again Monday as highs top out in the lower to middle 90s with heat index values in the upper 90s to around 100 degrees. An unstable air mass will once again be over the area, and with the heating of the day the cap should weaken enough for scattered storms to develop Monday afternoon. Theta-E differences greater than 25K combined with the unstably air mass will once again support a risk for localized damaging straight line winds with a few of the stronger storms Monday afternoon. .LONG TERM...(Monday Night through Saturday) Issued at 310 AM CDT SUN JUL 6 2014 An upper level trough will move out of the northern Plains on Monday night and southeast into the region on Tuesday along with a weak cold front. Storms are expected to develop along the front as it pushes south through the area. There will be a risk for strong to severe storms Tuesday afternoon given a moist and unstable air mass along with an increase in deep layer shear with the approach of the upper level trough. Hail to the size of quarters and winds in excess of 60 mph will be the main risks with this activity. Slightly cooler conditions will occur on Wednesday and Thursday behind the front with highs in the middle to upper 80s. An upper level ridge will begin to build towards the region by late in the week sending the front back to the north. A few storms may develop on Thursday and Friday as the front moves north. Warmer conditions are then expected this weekend as highs warm back into the 90s. && .AVIATION...(For the 12Z TAFS through 12Z Monday Morning) Issued at 647 AM CDT SUN JUL 6 2014 For the KSGF/KJLN/KBBG tafs: An area of scattered showers and thunderstorms will affect the KSGF and KJLN areas early, but in general expect vfr conditions for much of the taf period. The showers are expected to weaken over the next few hours. South winds will continue with sfc troughing remaining out of the Plains. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ UPDATE...Runnels SHORT TERM...Wise LONG TERM...Wise AVIATION...DSA
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
920 AM CDT Sun Jul 6 2014 .UPDATE... Issued at 919 AM CDT SUN JUL 6 2014 Updated POPs this morning to account for MCS descending southward into the western portion of the SGF CWA. HRRR is at odds with the new WRF as the HRRR maintains the MCS into the afternoon...while the 12z WRF follows the 06z WRF in diminishing the activity very rapidly this morning. Radar and IR trends do indicate a downward trend as the leading edge of the precipitation nears I-44...much in line with CIN gradient available from the SPC meso page. Typical MCS diurnal trends are supported by the strongly veered westerly low level jet though there is weak shortwave support. Updated POPs depict a diminishing trend though confidence is modest. && .SHORT TERM...(Today and Monday) Issued at 310 AM CDT SUN JUL 6 2014 Thunderstorms have developed across north central Missouri to the southwest into southeastern Kansas early this morning. This activity has developed on the nose of a low level jet a ahead of a weak upper level disturbance that is tracking south through the region. This activity will continue to develop and track to the south this morning and will mainly affect locations along an northwest of an Anderson to Bolivar to Vichy Missouri line this morning. This activity will weaken and dissipate by the mid morning hours with the strongest activity generally occurring before sunrise this morning. A few strong storms will be possible early this morning with hail to the size of pennies the main risk mainly before 7 AM this morning then storms should generally weaken as the morning moves a long. A warmer and more humid air mass is spreading north into the region and highs will top out in the upper 80s to the lower 90s this afternoon with heat index values in the middle 90s to near the 100 degree mark. Isolated storms could develop mainly east of Highway 65 this afternoon, but some capping is not expected to completely erode and there will not be much in the way of forcing in place. Therefore, this activity will be very isolated, if it can develop at all, and most locations will remain dry. If storms are able to develop this afternoon, instability will increase in excess of 2000J/kg of ML Cape and this instability and theta-E differences greater than 25K would support a localized downburst wind risk with a few of the storms that can develop. Hot and humid conditions will occur again Monday as highs top out in the lower to middle 90s with heat index values in the upper 90s to around 100 degrees. An unstable air mass will once again be over the area, and with the heating of the day the cap should weaken enough for scattered storms to develop Monday afternoon. Theta-E differences greater than 25K combined with the unstably air mass will once again support a risk for localized damaging straight line winds with a few of the stronger storms Monday afternoon. .LONG TERM...(Monday Night through Saturday) Issued at 310 AM CDT SUN JUL 6 2014 An upper level trough will move out of the northern Plains on Monday night and southeast into the region on Tuesday along with a weak cold front. Storms are expected to develop along the front as it pushes south through the area. There will be a risk for strong to severe storms Tuesday afternoon given a moist and unstable air mass along with an increase in deep layer shear with the approach of the upper level trough. Hail to the size of quarters and winds in excess of 60 mph will be the main risks with this activity. Slightly cooler conditions will occur on Wednesday and Thursday behind the front with highs in the middle to upper 80s. An upper level ridge will begin to build towards the region by late in the week sending the front back to the north. A few storms may develop on Thursday and Friday as the front moves north. Warmer conditions are then expected this weekend as highs warm back into the 90s. && .AVIATION...(For the 12Z TAFS through 12Z Monday Morning) Issued at 647 AM CDT SUN JUL 6 2014 For the KSGF/KJLN/KBBG tafs: An area of scattered showers and thunderstorms will affect the KSGF and KJLN areas early, but in general expect vfr conditions for much of the taf period. The showers are expected to weaken over the next few hours. South winds will continue with sfc troughing remaining out of the Plains. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ UPDATE...Runnels SHORT TERM...Wise LONG TERM...Wise AVIATION...DSA
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1203 AM CDT Sun Jul 6 2014 .SHORT TERM...(Tonight into Sunday) Issued at 254 PM CDT SAT JUL 5 2014 Currently, large expanse of high level clouds have enveloped much of the outlook area. This is blow off from a convective complex to our north. Over the past few hours, this area of showers and storms has rapidly decayed, with just a few lingering showers near northern portions of Miller/Maries counties. This activity will dissipate over the next hour or so, with additional development expected later. Temperatures have been affected, somewhat, by the high cloud coverage, with most locations in the upper 70s to lower 80s. The only exception is across extreme southeastern Kansas and western Missouri where mid/upper 80s are a bit more common. Anticipate that scattered TSRA will redevelop to the northwest of the CWA later today in line with the HRRR and NAM12...however models handling how this will propagate inconsistently. Given orientation of the moisture transport/low level Theta E would anticipate activity to build southwestward into the night...then take on an easterly component toward morning as the relatively weak low level jet veers east. Questions for convection then on Sunday more of a question. Should be plenty of instability and even a bit of support from a dampening short wave. However rain may be hard to come by unless the overnight convection is able to generate an outflow boundary. .LONG TERM...(Sunday night through Friday) Issued at 254 PM CDT SAT JUL 5 2014 Warming trend will continue into Monday with areas over the west witnessing the highest heat indices of the season before heights start to fall and a wavy weak front arrives on Tuesday. Models have been consistent with convective development along the front Tuesday into early Wednesday as the front slowly descends into Arkansas. Questions continue as to how far south the front makes it into Arkansas and scattered storms may then continue along the Arkansas border through the end of the work week. && .AVIATION...(For the 06Z TAFS through 06Z Sunday Night) Issued at 1143 PM CDT SAT JUL 5 2014 VFR conditions are expected through Sunday evening. An upper level disturbance will bring an increase in mid and high clouds into Sunday morning. We do expect a few showers and perhaps a thunderstorm or two across portions of western Missouri from late tonight into Sunday morning. We have opted to include vicinity showers at Joplin as thunderstorm coverage is expected to be limited. Otherwise, we are expecting dry conditions to persist with continued south winds at the surface. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SHORT TERM...Gagan/Runnels LONG TERM...Runnels AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
324 PM CDT SUN JUL 6 2014 .SYNOPSIS... ISSUED AT 324 PM CDT SUN JUL 6 2014 H5 ANALYSIS FROM EARLIER THIS MORNING HAS HIGH PRESSURE OVER NEVADA WITH A LOW AMPLITUDE RIDGE EXTENDING INTO SWRN CANADA. A SECONDARY HIGH WAS OVER NERN ALASKA WITH A SHARPER AMPLITUDE RIDGE EXTENDING NORTH INTO THE ARCTIC OCEAN. EAST OF THIS RIDGE...A TANDEM OF DECENT NORTHERN STREAM SHORTWAVES WERE PRESENT FROM NORTHERN ALBERTA INTO NORTHERN MANITOBA. DOWNSTREAM OF THESE SHORTWAVES...50+ METER HT FALLS WERE NOTED OVER NRN MN...SWRN ONTARIO AND SOUTHERN MANITOBA. ANOTHER AREA OF SHORTWAVE ENERGY WAS NOTED OVER THE OZARKS. AT THE SURFACE...A WEAK FRONTAL BOUNDARY HAD PASSED THROUGH WESTERN AND NORTH CENTRAL NEBRASKA AS OF NOONTIME AND WAS ORIENTED ALONG A LINE FROM NEAR FORT MORGAN COLORADO...TO MCCOOK TO SIOUX CITY IA. TEMPERATURES AS OF 3 PM CDT...RANGED FROM 86 AT VALENTINE TO 95 AT IMPERIAL. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 324 PM CDT SUN JUL 6 2014 THE PRIMARY CONCERNS THROUGH MONDAY WILL BE PRECIPITATION CHANCES TONIGHT AND MONDAY...THEN WITH HIGH TEMPERATURES ON MONDAY. THE COLD FRONT OVER NEBRASKA HAS PASSED THROUGH ALL OF THE LOCAL AREA AND ALTHOUGH DEWPOINTS JUST NORTH OF THE FRONT REMAIN IN THE 60S...WITH SB CAPE OF 2K J/KG OR HIGHER FROM ABOUT KOGA TO KBBW AND AREAS TO THE SOUTH...LAPS SOUNDINGS AND SPC/S MESOANALYSIS PAGE SUGGEST A SLIGHT CAP REMAINS IN THESE AREAS THIS AFTERNOON. WITH THE CAP AND A LACK OF FORCING TO HELP GET ANY ACTIVITY GOING DON/T EXPECT ANY STORMS LOCALLY THIS EVENING. SOUTH OF THE FRONT CIN HAS DIMINISHED SO COULD SEE STORMS DEVELOP IN THOSE AREAS. DON/T EXPECT THE FRONT TO LIFT NORTH SO HAVE NOT RE-INTRODUCED ANY CHANCES TO THE AREA THIS EVENING ALONG THE FRONT. LATER TONIGHT A FEW MODELS...INCLUDING THE NAM...GFS AND TO A POINT THE RAP SHOW A VERY WEAK PERTURBATION MOVING THROUGH THE MID LEVELS ACROSS CENTRAL NEBRASKA. THE SAME AREA WILL SEE POOLING OF LOW LEVEL MOISTURE WITH DEWPOINTS REMAINING IN THE 60S AND THERE IS SUGGESTION OF A BIT OF MOISTURE TRANSPORT AND CONVERGENCE ROUGHLY IN THE VICINITY OF A LINE FROM KBBW TO KEAR AND KHGI. CONFIDENCE ISN/T HIGH ON ANY OF THIS CONVECTION OCCURRING...NOR HAVING IT OCCUR IN THE FORECAST AREA BUT FELT THERE WAS ENOUGH SIGNALS TO AT LEAST WARRANT A SLIGHT CHANCE FOR THUNDERSTORMS. THEN...THE SHORTWAVE TROUGH CURRENTLY NORTH OF MONTANA WILL MOVE INTO THE NORTHERN PLAINS AND APPROACH NEBRASKA DURING THE DAY MONDAY. THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER WESTERN SOUTH DAKOTA LATE TONIGHT AND MOVE INTO NORTHERN NEBRASKA IN THE MORNING. WITH THE RECOVERY OF DEWPOINTS OVERNIGHT...WILL BE ABLE TO BUILD 1-2K J/KG OF SB CAPE IN THE MORNING AND WITH DEEP LAYER SHEAR INCREASING WITH THE SHORTWAVE MOVING IN CAN/T DISCOUNT A FEW STORMS GAINING STRENGTH TO BE A STRONGER STORM. AT THIS TIME DON/T FORESEE ANY SEVERE STORMS WITHIN THIS ACTIVITY. BY LATE IN THE AFTERNOON THE MOISTURE TRANSPORT ASSOCIATED WITH THE SHORTWAVE SHIFTS AND THEN FOCUSES ACROSS SOUTHERN NEBRASKA AND NORTHERN KANSAS WHERE THE FRONT FROM TODAY WILL REMAIN. THIS FRONT WILL SERVE AS THE FOCUS FOR ADDITIONAL DEVELOPMENT FOR LATE IN THE AFTERNOON AND EVENING. AT THIS POINT...CAPE AND DEEP LAYER SHEAR WILL HAVE INCREASED A BIT SO THE CHANCES FOR SEVERE STORMS WILL ALSO INCREASE. STILL NOT ANTICIPATING WIDESPREAD SEVERE WEATHER LOCALLY AS THE PRIMARY CONVERGENCE AREA LOOKS TO BE SOUTH OF THE FORECAST AREA AS THE MOISTURE TRANSPORT VECTORS ORIENTED SOUTH OVER THE FRONT. OVER THESE AREAS...PRECIPITABLE WATER VALUES ARE HIGH ONCE AGAIN...AT 120 TO 140 PERCENT OF NORMAL. HIGH WATER CONTENT...ALONG WITH A WEST TO EAST ORIENTED FRONT AND MOISTURE TRANSPORT PERPENDICULAR TO THE FRONT COULD SUGGEST POTENTIAL TRAINING STORMS AND HEAVY RAIN. AGAIN...THINK THE HIGHER THREAT THOUGH WILL BE SOUTH OF THE LOCAL FORECAST AREA. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 324 PM CDT SUN JUL 6 2014 MONDAY NIGHT THROUGH WEDNESDAY NIGHT...THE MAIN FORECAST CHALLENGES IN THE MID RANGE ARE LINGERING CHANCES FOR PCPN MONDAY NIGHT AND TEMPERATURES. FOR MONDAY NIGHT...A SLOW MOVING FRONT WILL PUSH INTO KANSAS LATE MONDAY INTO MONDAY NIGHT. THERE WILL CONTINUE TO BE A THREAT FOR PCPN IN THE EAST AND SOUTH MONDAY EVENING...AS DECENT MID LEVEL LIFT WILL PERSIST NORTH OF THE FRONTAL BOUNDARY. THIS AREA IS MORE PREVALENT IN THE FORECAST AREA PER THE GFS SOLN COMPARED TO THE NAM SOLN AS THE SURFACE FRONT IS FURTHER NORTH COMPARED TO THE NAM SOLN. THIS PROBABLY HAS TO DO WITH THE STRENGTH OF HIGH PRESSURE BEHIND THE FRONT...WHICH THE NAM IS STRONGER WITH COMPARED TO THE GFS SOLN. INHERITED FCST HAD CHANCE POPS LINGERING INTO THE OVERNIGHT IN THE SOUTH AND EAST. POPS WERE LOWERED MONDAY NIGHT GIVEN THE FASTER NAM SOLN...AS WELL AS MID LEVEL LIFT SHIFTING SOUTH OF THE FORECAST AREA OVERNIGHT. AS FOR THE THREAT FOR ANY SEVERE STORMS LINGERING INTO THE EVENING HOURS. AT THIS TIME...THE BEST THREAT OF SEVERE STORMS IS EXPECTED TO BE IN THE EAST AND SERN CWA WHERE SFC DEW POINTS WILL BE IN THE 60S. DEEP LAYER SHEAR WILL BE STRONG ACROSS THE ENTIRE CWA...HOWEVER THE COMBINATION OF THE TWO PREVIOUSLY MENTIONED ELEMENTS WILL BE MOST FAVORABLE IN THE EAST AND SERN CWA. HIGH PRESSURE WILL PUSH INTO THE WESTERN DAKOTAS AND NEBRASKA ON TUESDAY. MUCH DRIER AIR WILL PUSH INTO THE AREA AS WELL...ELIMINATING THE THREAT FOR PCPN TUESDAY. BY TUESDAY NIGHT HIGH PRESSURE WILL DRIFT EAST INTO EASTERN NEBRASKA. SOUTHERLY WINDS WILL INCREASE OVERNIGHT...PARTICULARLY IN THE WEST WHICH WILL GIVE A BOOST TO OVERNIGHT LOWS WEST OF NORTH PLATTE. ANY PCPN ACROSS THE HIGH PLAINS...WILL BE CONFINED TO THE FRONT RANGE OF COLORADO AND WILL QUICKLY SUBSIDE DURING THE EVENING HOURS TUESDAY. RIDGING ACROSS THE INTERMOUNTAIN WEST WILL BEGIN TO PUSH EAST ON WEDNESDAY. TEMPERATURES WILL BEGIN TO CLIMB AND WILL APPROACH THE UPPER 80S TO NEAR 90 IN THE WEST WEDNESDAY. THIS IS ABOUT 5 TO 10 DEGREES WARMER THAN FORECAST HIGHS ON TUESDAY. THE THREAT FOR ISOLATED TSRAS WILL INCREASE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT AS A WEAK UPPER LEVEL DISTURBANCE LIFTS SE FROM THE NRN PERIPHERY OF THE UPPER LEVEL HIGH. BOTH THE NAM AND GFS INITIATE ISOLATED STORMS INVOF THE BLACK HILLS WEDS AFTN. WITH NORTHWESTERLY FLOW ALOFT...ANY STORMS WHICH INITIATE MAY PUSH INTO THE NWRN CWA WEDS AFTN/EVENING. WILL KEEP POPS ISOLATED FOR NOW AS MOISTURE WILL BE FAIRLY LIMITED...ESPECIALLY IN THE WEST AND NWRN CWA. THURSDAY THROUGH SUNDAY...FOR THE END OF THE WEEK INTO NEXT WEEKEND...HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER PATTERN ACROSS THE SOUTHERN ROCKIES AND SOUTHERN PLAINS. THIS USUALLY ALLOWS A PLETHORA OF MID AND UPPER LEVEL DISTURBANCES TO IMPACT THE CENTRAL AND NORTHERN PLAINS ON THE NORTHERN PERIPHERY OF THIS HIGH PRESSURE. TIMING OF THESE DISTURBANCES IS DIFFICULT TO TIME THIS FAR OUT...SO WILL KEEP POPS LOW IN THE EXTENDED PERIODS. MOISTURE WILL BE AVAILABLE FOR THUNDERSTORM DEVELOPMENT...WITH PLENTY OF MONSOONAL MOISTURE LIFTING NORTH ACROSS THE SOUTHERN AND CENTRAL ROCKIES...SO CANNOT TOTALLY RULE OUT THE THE THREAT FOR STORMS. AS FOR TEMPERATURES LATER IN THE WEEK AND NEXT WEEKEND...UNDERCUT THE LATEST MEX GUIDANCE AS IT CONTINUES TO BE TOO WARM COMPARED TO THE ENSEMBLE MEANS...AS WELL AS THE ECMX EURO GUIDANCE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 110 PM CDT SUN JUL 6 2014 SHOWERS AND STORMS WILL BECOME POSSIBLE LATER TONIGHT OVER NORTH CENTRAL INTO CENTRAL NEBRASKA AS AN UPPER LEVEL SYSTEM MOVES INTO THE PLAINS OUT OF MONTANA. DON/T HAVE HIGH CONFIDENCE ON EXACT AREAS THAT WILL GET MOISTURE AS FORECAST MODELS DON/T HAVE A HIGH LEVEL OF AGREEMENT AT THIS POINT STILL. HOWEVER...WITH THE BETTER MOISTURE AND UPWARD MOTION LOOKING TO MOVE INTO THE AREA IN THE MORNING HOURS DID ADD IN A PREVAILING VCTS AT KVTN WHERE THERE IS A BIT HIGHER CONFIDENCE AND WHERE THE BETTER FORCING IS EXPECTED. WINDS WILL DIMINISH TONIGHT AND BE LIGHT AND VARIABLE BEFORE SWITCHING TO THE NORTHWEST BY LATE MORNING OVER PARTS OF NORTHWEST NEBRASKA. WITH THE EXCEPTION OF THE PASSAGE OF RAINFALL WITH ANY THUNDERSTORMS CONDITIONS WILL BE VFR THROUGH THE NEXT 24 HOURS. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...BROOKS LONG TERM...CLB AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
314 PM CDT SUN JUL 6 2014 .SHORT TERM...(TONIGHT THROUGH WEDNESDAY) ISSUED AT 203 PM CDT SUN JUL 6 2014 SURFACE COLD FRONT STRETCHED FROM SOUTHWEST MINNESOTA THROUGH EAST CENTRAL NEBRASKA AND NORTHWEST KANSAS AT 19Z. NOT MUCH IN THE WAY OF CU DEVELOPMENT AHEAD OF THE FRONT SO FAR BUT NOTABLY DRIER AIR BEHIND IT WITH DEWPOINTS IN THE 50S AND 60S. CONVERGENCE RATHER WEAK AS FRONT DRIFTS SLOWLY SOUTH THIS AFTERNOON BEFORE STALLING ALONG THE KANSAS NEBRASKA BORDER THIS EVENING AND WASHING OUT OVERNIGHT. HAVE CARRIED SOME LOW POPS IN THE SOUTH PORTION OF THE AREA FOR TONIGHT WHERE RAP MODEL SHOWS SOME POTENTIAL BUT ONLY ISOLATED COVERAGE EXPECTED IT STORMS DO DEVELOP. A BETTER CHANCE FOR STORMS IN THE AREA MONDAY AFTERNOON AND MONDAY NIGHT AS FAIRLY STRONG MID LEVEL WAVE AND ASSOCIATED JET MAX MOVES ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST HELPING TO PUSH A STRONGER COLD FRONT DOWN ACROSS THE REGION. POTENTIAL FOR HEAVY RAIN EXISTS FOR THE SOUTHERN BORDER AREA MONDAY NIGHT DEPENDING ON ACTUAL LOCATION OF THE FRONT AS STORMS TAKE ON A WEST-EAST ORIENTATION JUST NORTH OF THE BOUNDARY. REMAINDER OF THE PERIOD LOOKS WARM AND DRY FOR TUESDAY AND MOST OF WEDNESDAY WITH LESS HUMIDITY AROUND AS FRONT IS PUSHED FURTHER SOUTH AND HIGH PRESSURE MOVES INTO THE REGION. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 203 PM CDT SUN JUL 6 2014 MOISTURE RETURNS WEDNESDAY NIGHT AS HIGH MOVES TO THE EAST AND SOUTHERLY FLOW INCREASES ACROSS THE REGION. SERIES OF ADDITIONAL SHORT WAVE TROUGHS DURING THE PERIOD INDICATED BY MODELS AS RIDGE BUILDS AGAIN IN THE WEST WILL HAVE POTENTIAL FOR MORE STORMS FOR THE AREA PRIMARILY DURING OVERNIGHT PERIODS AS MID SUMMER PATTERN TAKES SHAPE. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1222 PM CDT SUN JUL 6 2014 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SFC CDFNT IS THROUGH THE KOFK TERMINAL AND WILL BE THRU KOMA/KLNK BETWEEN 19-20Z. THIS WILL SWITCH THE WINDS TO N/NW THRU THE OVERNIGHT HOURS. ANY CONVECTIVE THREAT IS TO MINIMAL TO INCLUDE IN THE TAF...AND IF IT OCCURRED WOULD BE MOST LIKELY AT KLNK AFTER 06Z. ANOTHER FRONT WILL MOVE INTO THE AREA ON MON LEADING TO CHCS FOR TSRA BUT THIS APPEARS TO BE AFTER THIS TAF PERIOD. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...FOBERT LONG TERM...FOBERT AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1225 PM CDT SUN JUL 6 2014 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 311 AM CDT SUN JUL 6 2014 THERE ARE THREE PRIMARY FORECAST CHALLENGES CURRENTLY BEING CONSIDERED: -HEAT INDEX VALUES TODAY -CONVECTION CHANCES THIS AFTERNOON AND EVENING IN THE SOUTH -SEVERE AND HEAVY RAIN POTENTIAL FOR MONDAY AFTERNOON AND NIGHT AT 07Z...SURFACE COLD FRONT WAS ANALYZED FROM NORTH CENTRAL SOUTH DAKOTA INTO FAR NORTHWEST NEBRASKA AND HAD JUST MOVE THROUGH PINE RIDGE. FRONT SHOULD REACH SOUTHEAST NEBRASKA BY LATE AFTERNOON. AIRMASS OVER FORECAST AREA AHEAD OF THE FRONT WILL BE QUITE HUMID WITH DEWPOINTS IN THE LOW TO MID 70S...WITH ONLY SLIGHT COOLING BEHIND THE FRONT. ALOFT...WEAK RIDGING WAS NOTED UPSTREAM WITH MINOR HEIGHT RISES AT 500 MB ACROSS THE DAKOTAS INTO NEBRASKA...WITH FAIRLY WARM MID LEVEL TEMPERATURES. THEREIN LIES THE QUESTION OF THE PAST COUPLE OF DAYS...TRYING TO DETERMINE WHETHER THE FRONT WILL BE ABLE TO TRIGGER CONVECTION TODAY IN A WARM AIRMASS WITH A MODEST CAP AND A LACK OF DEEP VERTICAL MOTION FROM ANY DISTINCT LIFTING MECHANISM OTHER THAN THE FRONT. THE 00Z NAM AND THE 06Z RAP ARE IN GOOD AGREEMENT WITH DEVELOPING CONVECTION ALONG THE FRONT IN THE 22Z-23Z TIME FRAME...AND THE 00Z GFS DEVELOPS IT SLIGHTLY POST FRONTAL BETWEEN 00Z-06Z. NOT SURPRISINGLY...THE NAM AND RAP BOTH ERODE THE CAP FROM ABOUT LINCOLN SOUTH...AND INDICATE VERTICAL MOTION ON THE ORDER OF -4 MICROBARS/SEC THROUGH AROUND 600MB. GIVEN THESE POSSIBLE SCENARIOS...WILL GO WITH A SLIGHT CHANCE IN SOUTHEAST NEBRASKA/SOUTHWEST IOWA FROM 22Z-03Z. REGARDING THE HEAT AND HUMIDITY TODAY...THE COOLING BEHIND THE FRONT IS A CONCERN BUT NEARLY FULL SUN SHOULD KEEP TEMPERATURES FROM DROPPING MUCH. A DEGREE OR TWO DROP IN DEWPOINTS IS EXPECTED IN NORTHERN COUNTIES...BUT NOT IN SOUTHERN COUNTIES UNTIL WELL AFTER THE FRONT PASSES. GENERALLY HAVE NOT MADE CHANGES TO TEMPS TODAY...BUT DID RAISE DEWPOINTS A FEW DEGREES BASED ON READINGS SATURDAY. BOTTOM LINE IS HEAT INDEX VALUES OF 95-100 NORTH AND 100-105 SOUTH. LOOKS LIKE MOST SOUTHERN COUNTIES WILL REMAIN JUST SHY OF HEAT ADVISORY CRITERIA. MODELS IN REASONABLY GOOD AGREEMENT WITH WET PATTERN FOR MONDAY AFTERNOON INTO MONDAY NIGHT. CURRENT FORECAST HAS THIS PERIOD HANDLED WELL. ONLY CHANGES WILL BE TO INCREASE POPS FOR NORTHWEST AREAS MONDAY AFTERNOON...AND ALSO MENTION HEAVY RAIN MONDAY NIGHT ESPECIALLY SOUTH OF I-80 WHERE RECENT RAINS HAVE CAUSED FLOODING IN SOUTHWEST IOWA. HEAVY RAIN OVER THE SOUTHERN COUNTIES LOOKS POSSIBLE GIVEN THE STRONG FRONTAL CONVERGENCE IN THE LOW LEVELS FOR 9-12 HOURS... JET DIVERGENCE AND SHEARED VORTICITY IN NORTHWEST FLOW CAUSING A PROLONGED PERIOD OF LIFT...AND ABUNDANT MOISTURE/INSTABILITY. NAM AND GFS SHOW QUITE STRONG THETA-E ADVECTION FROM 850-700. THIS IS A CONCERN GIVEN THE CURRENT FLOODING IN THE NISHNABOTNA RIVER BASIN IN SOUTHWEST IOWA. WPC DAY 2 EXCESSIVE RAIN GRAPHIC SUPPORTS THIS AS WELL. INGREDIENTS FOR SEVERE CONVECTION MONDAY AFTERNOON AND EVENING APPEAR TO BE LINING UP...PER SPC DAY 2 DISCUSSION. INSTABILITY AND DEEP LAYER SHEAR PARAMETERS MORE THAN SUPPORT A SEVERE WEATHER OUTBREAK WITH UNSEASONABLY FAST UPPER FLOW. BOWING SEGMENTS ALONG THE FRONTAL BOUNDARY IN SOUTHEAST NEBRASKA/SOUTHWEST IOWA SEEM LIKELY. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 311 AM CDT SUN JUL 6 2014 BY LATE TUESDAY THE PRIMARY SYNOPTIC FRONT SHOULD MOVE WELL SOUTH OF THE AREA WITH SURFACE HIGH PRESSURE MOVING INTO THE FORECAST AREA. DRY CONDITIONS ARE EXPECTED TUESDAY NIGHT INTO WEDNESDAY. BY THURSDAY...RETURN FLOW BRINGS MOISTURE BACK INTO THE REGION AND THE UPPER PATTERN MAINTAINS A SOMEWHAT UNSETTLED NORTHWEST FLOW REGIME WITH SOME POTENTIAL FOR MCS ACTIVITY...BUT CONFIDENCE IS LOW THURSDAY INTO SATURDAY. TEMPERATURES SHOULD BE CLOSE TO NORMAL OR A FEW DEGREES BELOW NORMAL. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1222 PM CDT SUN JUL 6 2014 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SFC CDFNT IS THROUGH THE KOFK TERMINAL AND WILL BE THRU KOMA/KLNK BETWEEN 19-20Z. THIS WILL SWITCH THE WINDS TO N/NW THRU THE OVERNIGHT HOURS. ANY CONVECTIVE THREAT IS TO MINIMAL TO INCLUDE IN THE TAF...AND IF IT OCCURRED WOULD BE MOST LIKELY AT KLNK AFTER 06Z. ANOTHER FRONT WILL MOVE INTO THE AREA ON MON LEADING TO CHCS FOR TSRA BUT THIS APPEARS TO BE AFTER THIS TAF PERIOD. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...NIETFELD LONG TERM...NIETFELD AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
734 AM CDT SUN JUL 6 2014 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 311 AM CDT SUN JUL 6 2014 THERE ARE THREE PRIMARY FORECAST CHALLENGES CURRENTLY BEING CONSIDERED: -HEAT INDEX VALUES TODAY -CONVECTION CHANCES THIS AFTERNOON AND EVENING IN THE SOUTH -SEVERE AND HEAVY RAIN POTENTIAL FOR MONDAY AFTERNOON AND NIGHT AT 07Z...SURFACE COLD FRONT WAS ANALYZED FROM NORTH CENTRAL SOUTH DAKOTA INTO FAR NORTHWEST NEBRASKA AND HAD JUST MOVE THROUGH PINE RIDGE. FRONT SHOULD REACH SOUTHEAST NEBRASKA BY LATE AFTERNOON. AIRMASS OVER FORECAST AREA AHEAD OF THE FRONT WILL BE QUITE HUMID WITH DEWPOINTS IN THE LOW TO MID 70S...WITH ONLY SLIGHT COOLING BEHIND THE FRONT. ALOFT...WEAK RIDGING WAS NOTED UPSTREAM WITH MINOR HEIGHT RISES AT 500 MB ACROSS THE DAKOTAS INTO NEBRASKA...WITH FAIRLY WARM MID LEVEL TEMPERATURES. THEREIN LIES THE QUESTION OF THE PAST COUPLE OF DAYS...TRYING TO DETERMINE WHETHER THE FRONT WILL BE ABLE TO TRIGGER CONVECTION TODAY IN A WARM AIRMASS WITH A MODEST CAP AND A LACK OF DEEP VERTICAL MOTION FROM ANY DISTINCT LIFTING MECHANISM OTHER THAN THE FRONT. THE 00Z NAM AND THE 06Z RAP ARE IN GOOD AGREEMENT WITH DEVELOPING CONVECTION ALONG THE FRONT IN THE 22Z-23Z TIME FRAME...AND THE 00Z GFS DEVELOPS IT SLIGHTLY POST FRONTAL BETWEEN 00Z-06Z. NOT SURPRISINGLY...THE NAM AND RAP BOTH ERODE THE CAP FROM ABOUT LINCOLN SOUTH...AND INDICATE VERTICAL MOTION ON THE ORDER OF -4 MICROBARS/SEC THROUGH AROUND 600MB. GIVEN THESE POSSIBLE SCENARIOS...WILL GO WITH A SLIGHT CHANCE IN SOUTHEAST NEBRASKA/SOUTHWEST IOWA FROM 22Z-03Z. REGARDING THE HEAT AND HUMIDITY TODAY...THE COOLING BEHIND THE FRONT IS A CONCERN BUT NEARLY FULL SUN SHOULD KEEP TEMPERATURES FROM DROPPING MUCH. A DEGREE OR TWO DROP IN DEWPOINTS IS EXPECTED IN NORTHERN COUNTIES...BUT NOT IN SOUTHERN COUNTIES UNTIL WELL AFTER THE FRONT PASSES. GENERALLY HAVE NOT MADE CHANGES TO TEMPS TODAY...BUT DID RAISE DEWPOINTS A FEW DEGREES BASED ON READINGS SATURDAY. BOTTOM LINE IS HEAT INDEX VALUES OF 95-100 NORTH AND 100-105 SOUTH. LOOKS LIKE MOST SOUTHERN COUNTIES WILL REMAIN JUST SHY OF HEAT ADVISORY CRITERIA. MODELS IN REASONABLY GOOD AGREEMENT WITH WET PATTERN FOR MONDAY AFTERNOON INTO MONDAY NIGHT. CURRENT FORECAST HAS THIS PERIOD HANDLED WELL. ONLY CHANGES WILL BE TO INCREASE POPS FOR NORTHWEST AREAS MONDAY AFTERNOON...AND ALSO MENTION HEAVY RAIN MONDAY NIGHT ESPECIALLY SOUTH OF I-80 WHERE RECENT RAINS HAVE CAUSED FLOODING IN SOUTHWEST IOWA. HEAVY RAIN OVER THE SOUTHERN COUNTIES LOOKS POSSIBLE GIVEN THE STRONG FRONTAL CONVERGENCE IN THE LOW LEVELS FOR 9-12 HOURS... JET DIVERGENCE AND SHEARED VORTICITY IN NORTHWEST FLOW CAUSING A PROLONGED PERIOD OF LIFT...AND ABUNDANT MOISTURE/INSTABILITY. NAM AND GFS SHOW QUITE STRONG THETA-E ADVECTION FROM 850-700. THIS IS A CONCERN GIVEN THE CURRENT FLOODING IN THE NISHNABOTNA RIVER BASIN IN SOUTHWEST IOWA. WPC DAY 2 EXCESSIVE RAIN GRAPHIC SUPPORTS THIS AS WELL. INGREDIENTS FOR SEVERE CONVECTION MONDAY AFTERNOON AND EVENING APPEAR TO BE LINING UP...PER SPC DAY 2 DISCUSSION. INSTABILITY AND DEEP LAYER SHEAR PARAMETERS MORE THAN SUPPORT A SEVERE WEATHER OUTBREAK WITH UNSEASONABLY FAST UPPER FLOW. BOWING SEGMENTS ALONG THE FRONTAL BOUNDARY IN SOUTHEAST NEBRASKA/SOUTHWEST IOWA SEEM LIKELY. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 311 AM CDT SUN JUL 6 2014 BY LATE TUESDAY THE PRIMARY SYNOPTIC FRONT SHOULD MOVE WELL SOUTH OF THE AREA WITH SURFACE HIGH PRESSURE MOVING INTO THE FORECAST AREA. DRY CONDITIONS ARE EXPECTED TUESDAY NIGHT INTO WEDNESDAY. BY THURSDAY...RETURN FLOW BRINGS MOISTURE BACK INTO THE REGION AND THE UPPER PATTERN MAINTAINS A SOMEWHAT UNSETTLED NORTHWEST FLOW REGIME WITH SOME POTENTIAL FOR MCS ACTIVITY...BUT CONFIDENCE IS LOW THURSDAY INTO SATURDAY. TEMPERATURES SHOULD BE CLOSE TO NORMAL OR A FEW DEGREES BELOW NORMAL. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 734 AM CDT SUN JUL 6 2014 DENSE FOG/LOW CIGS HAVE SET IN AT KOFK...RECENT OBSERVATIONS INDICATE THIS CONDITION WILL SLOWLY IMPROVE TO VFR IN THE NEXT THREE HOURS. LIGHT FOG HAS BEEN REPORTED AT THE OTHER SITES AND BY 15Z ALL THREE SITES SHOULD BE INTO VFR. A SCATTERED TO BROKEN MID DECK WILL PUSH THROUGH THE AREA THIS AFTERNOON...BUT DO NOT ANTICIPATE ANYTHING OTHER THAN VFR. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...NIETFELD LONG TERM...NIETFELD AVIATION...PEARSON
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
311 AM CDT SUN JUL 6 2014 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 311 AM CDT SUN JUL 6 2014 THERE ARE THREE PRIMARY FORECAST CHALLENGES CURRENTLY BEING CONSIDERED: -HEAT INDEX VALUES TODAY -CONVECTION CHANCES THIS AFTERNOON AND EVENING IN THE SOUTH -SEVERE AND HEAVY RAIN POTENTIAL FOR MONDAY AFTERNOON AND NIGHT AT 07Z...SURFACE COLD FRONT WAS ANALYZED FROM NORTH CENTRAL SOUTH DAKOTA INTO FAR NORTHWEST NEBRASKA AND HAD JUST MOVE THROUGH PINE RIDGE. FRONT SHOULD REACH SOUTHEAST NEBRASKA BY LATE AFTERNOON. AIRMASS OVER FORECAST AREA AHEAD OF THE FRONT WILL BE QUITE HUMID WITH DEWPOINTS IN THE LOW TO MID 70S...WITH ONLY SLIGHT COOLING BEHIND THE FRONT. ALOFT...WEAK RIDGING WAS NOTED UPSTREAM WITH MINOR HEIGHT RISES AT 500 MB ACROSS THE DAKOTAS INTO NEBRASKA...WITH FAIRLY WARM MID LEVEL TEMPERATURES. THEREIN LIES THE QUESTION OF THE PAST COUPLE OF DAYS...TRYING TO DETERMINE WHETHER THE FRONT WILL BE ABLE TO TRIGGER CONVECTION TODAY IN A WARM AIRMASS WITH A MODEST CAP AND A LACK OF DEEP VERTICAL MOTION FROM ANY DISTINCT LIFTING MECHANISM OTHER THAN THE FRONT. THE 00Z NAM AND THE 06Z RAP ARE IN GOOD AGREEMENT WITH DEVELOPING CONVECTION ALONG THE FRONT IN THE 22Z-23Z TIME FRAME...AND THE 00Z GFS DEVELOPS IT SLIGHTLY POST FRONTAL BETWEEN 00Z-06Z. NOT SURPRISINGLY...THE NAM AND RAP BOTH ERODE THE CAP FROM ABOUT LINCOLN SOUTH...AND INDICATE VERTICAL MOTION ON THE ORDER OF -4 MICROBARS/SEC THROUGH AROUND 600MB. GIVEN THESE POSSIBLE SCENARIOS...WILL GO WITH A SLIGHT CHANCE IN SOUTHEAST NEBRASKA/SOUTHWEST IOWA FROM 22Z-03Z. REGARDING THE HEAT AND HUMIDITY TODAY...THE COOLING BEHIND THE FRONT IS A CONCERN BUT NEARLY FULL SUN SHOULD KEEP TEMPERATURES FROM DROPPING MUCH. A DEGREE OR TWO DROP IN DEWPOINTS IS EXPECTED IN NORTHERN COUNTIES...BUT NOT IN SOUTHERN COUNTIES UNTIL WELL AFTER THE FRONT PASSES. GENERALLY HAVE NOT MADE CHANGES TO TEMPS TODAY...BUT DID RAISE DEWPOINTS A FEW DEGREES BASED ON READINGS SATURDAY. BOTTOM LINE IS HEAT INDEX VALUES OF 95-100 NORTH AND 100-105 SOUTH. LOOKS LIKE MOST SOUTHERN COUNTIES WILL REMAIN JUST SHY OF HEAT ADVISORY CRITERIA. MODELS IN REASONABLY GOOD AGREEMENT WITH WET PATTERN FOR MONDAY AFTERNOON INTO MONDAY NIGHT. CURRENT FORECAST HAS THIS PERIOD HANDLED WELL. ONLY CHANGES WILL BE TO INCREASE POPS FOR NORTHWEST AREAS MONDAY AFTERNOON...AND ALSO MENTION HEAVY RAIN MONDAY NIGHT ESPECIALLY SOUTH OF I-80 WHERE RECENT RAINS HAVE CAUSED FLOODING IN SOUTHWEST IOWA. HEAVY RAIN OVER THE SOUTHERN COUNTIES LOOKS POSSIBLE GIVEN THE STRONG FRONTAL CONVERGENCE IN THE LOW LEVELS FOR 9-12 HOURS... JET DIVERGENCE AND SHEARED VORTICITY IN NORTHWEST FLOW CAUSING A PROLONGED PERIOD OF LIFT...AND ABUNDANT MOISTURE/INSTABILITY. NAM AND GFS SHOW QUITE STRONG THETA-E ADVECTION FROM 850-700. THIS IS A CONCERN GIVEN THE CURRENT FLOODING IN THE NISHNABOTNA RIVER BASIN IN SOUTHWEST IOWA. WPC DAY 2 EXCESSIVE RAIN GRAPHIC SUPPORTS THIS AS WELL. INGREDIENTS FOR SEVERE CONVECTION MONDAY AFTERNOON AND EVENING APPEAR TO BE LINING UP...PER SPC DAY 2 DISCUSSION. INSTABILITY AND DEEP LAYER SHEAR PARAMETERS MORE THAN SUPPORT A SEVERE WEATHER OUTBREAK WITH UNSEASONABLY FAST UPPER FLOW. BOWING SEGMENTS ALONG THE FRONTAL BOUNDARY IN SOUTHEAST NEBRASKA/SOUTHWEST IOWA SEEM LIKELY. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 311 AM CDT SUN JUL 6 2014 BY LATE TUESDAY THE PRIMARY SYNOPTIC FRONT SHOULD MOVE WELL SOUTH OF THE AREA WITH SURFACE HIGH PRESSURE MOVING INTO THE FORECAST AREA. DRY CONDITIONS ARE EXPECTED TUESDAY NIGHT INTO WEDNESDAY. BY THURSDAY...RETURN FLOW BRINGS MOISTURE BACK INTO THE REGION AND THE UPPER PATTERN MAINTAINS A SOMEWHAT UNSETTLED NORTHWEST FLOW REGIME WITH SOME POTENTIAL FOR MCS ACTIVITY...BUT CONFIDENCE IS LOW THURSDAY INTO SATURDAY. TEMPERATURES SHOULD BE CLOSE TO NORMAL OR A FEW DEGREES BELOW NORMAL. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1055 PM CDT SAT JUL 5 2014 SOME FOG IS POSSIBLE AT ALL THREE SITES LATER TONIGHT AND EARLY SUNDAY WITH RECENT RAINS AND FORECASTED LOW DEWPOINT DEPRESSIONS/LIGHT OR NEARLY CALM WIND. CONVECTIVE DEBRIS WITH INCREASING HIGH CLOUDS SHOULD TEMPER THIS...BUT DID INCLUDE A TEMPO GROUP MAINLY BETWEEN 09-13Z. A COLD FRONT WILL MOVE INTO THE AREA WITH WINDS SHIFTING TO THE NORTHWEST BETWEEN 15-18Z AT KOFK AND CLOSER TO 21Z AT KOMA AND KLNK. VERY WARM MID LEVEL TEMPERATURES ARE IN PLACE...HOWEVER HEATING WELL INTO THE 90S...WEAK LIFT...AND STEEP LAPSE RATES COULD BE ENOUGH TO BREAK THE CAP AND ALLOW THUNDERSTORMS TO DEVELOP. OR...THE CAP MAY HOLD. THINK THERE IS ENOUGH OF A POSSIBILITY TO INCLUDE VCTS AT 21Z/22Z AT KLNK WITH THE FRONT PASSING THROUGH AT PEAK HEATING. MAY HAVE TO INCLUDE AT OMAHA DEPENDING ON HOW THINGS DEVELOP. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...NIETFELD LONG TERM...NIETFELD AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1245 AM CDT SUN JUL 6 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 305 PM CDT SAT JUL 5 2014 MAIN FORECAST CONCERNS WILL BE SHOWERS AND THUNDERSTORMS SOUTHEAST THIS AFTERNOON AND EVENING AND AGAIN LATE SUNDAY AFTERNOON...AND TEMPERATURES. CLOUDS HAVE ABOUT MOVED OUT OF THE FORECAST AREA THIS AFTERNOON BUT A FEW THIS AFTERNOON HAVE DEVELOPED ON THE EASTERN FRINGES OF THE FORECAST AREA AND PRODUCED A FEW SPRINKLES. AN UPPER LEVEL WAVE MOVES THROUGH THE AREA LATE THIS AFTERNOON AND EVENING. MODELS HAVE SOME DIFFERENCES IN THE STRENGTH OF THE WAVE AND WHAT HAPPENS AS IT MOVES THROUGH. THE NAM...THE RAP AND THE HRRR PRODUCE A LITTLE QPF/THUNDERSTORMS JUST TO THE SOUTHEAST OF THE FORECAST AREA FOR A BRIEF PERIOD LATE THIS AFTERNOON AND EARLY THIS EVENING. WITH THE SPRINKLES THAT FORMED EARLIER BELIEVE THAT A 20 PERCENT CHANCE COULD BE A GOOD IDEA IN THE FAR SOUTHEAST. NOT EXPECTING THERE TO BE MUCH BUT A FEW STORMS COULD DEVELOP. A SURFACE LOW AND COOL FRONT HAVE STARTED TO DEVELOP ON THE HIGH PLAINS THIS AFTERNOON. THIS FRONT APPROACHES THE FORECAST AREA TONIGHT AND MOVES INTO THE AREA DURING THE DAY SUNDAY. EVEN WITH THE FRONT MOVING INTO THE AREA THE TEMPERATURES ARE EXPECTED TO RISE WELL INTO THE 90S TO AROUND 100 DEGREES DURING THE DAY. AS THE FRONT MOVES THROUGH THE AREA...THERE IS A WEAK UPPER LEVEL WAVE THAT MOVES THROUGH THE AREA AS WELL. HAVE KEPT THE SMALL POPS IN FOR MUCH OF THE AREA DURING THE LATE AFTERNOON SUNDAY. THE MODELS HAVE DIFFERENCES ON THIS AS WELL. MANY OF THE MODELS ARE DRY...BUT A FEW SHOW SOME THUNDERSTORMS NEAR AND NORTH OF THE FRONT LATE IN THE AFTERNOON. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 305 PM CDT SAT JUL 5 2014 PATTERN: IT IS LOOKING DECIDEDLY MORE SUMMERLIKE. OVERALL THE MEAN LONGWAVE FLOW WILL FEATURE A WRN USA RIDGE/ERN USA TROF WITH SEASONABLE CHANGES IN AMPLITUDE. ONE THING IS CLEAR...WE HAVE TRANSITIONED TO A CONSIDERABLY DRIER PATTERN. THE PATTERN THAT BROUGHT THE VERY WET JUNE IS NO LONGER WITH US...AND ABOVE NORMAL HEIGHTS FCST OVER THE WRN AND CNTRL USA THRU MID-MONTH THREATEN SOME PERSISTENCE TO THIS DRYNESS. THE ONLY DECENT PROSPECT FOR MEANINGFUL RAIN FOR THE NEXT 7 DAYS IS MON NIGHT AND EVEN THEN NOT ALL AREAS WILL GET IT. EXPECT IRRIGATION WILL BE NECESSARY VERY SOON. ONE THING NOTED BY THE WPC /WX PREDICTION CTR AT NWSHQ/ IS TYPHOON NEOGURI FCST TO RECURVE IN THE WRN PACIFIC. ITS EXTRATROPICAL TRANSITION AND ABSORPTION INTO THE WESTERLIES COULD RESULT IN A PATTERN RE-ADJUSTMENT AROUND MID-MONTH. ALOFT: THE SUMMERTIME SUBTROPICAL HIGH HAS FINALLY DEVELOPED AND WILL BE OVER THE SW USA THRU MID-WEEK. STORMINESS OVER THE GULF OF AK WILL FORCE A TEMPORARY AMPLIFICATION OF THE RIDGE INTO WRN CANADA. THIS WILL LOWER HEIGHTS AND SEND A SHOT OF COOLER AIR INTO THE CNTRL/ERN USA THIS WEEK. THE ASSOCIATED TROF WILL SLIDE THRU MON NIGHT FOLLOWED BY CYCLONIC NW FLOW TUE-WED. A SHORTWAVE RIDGE WILL MOVE THRU THU AHEAD OF A TROF MOVING IN OFF THE PACIFIC. WHILE THE ENSEMBLE MEANS KEEP THIS TROF WILL ACTUALLY STAY N OF THE BORDER... ALLOWING HEIGHTS TO RISE AND THE SUBTROPICAL HIGH TO EXPAND ACROSS THE SRN 2/3 OF THE CONUS...AM NOT BUYING IT. THE PAST 2 EC/GEM/GFS CYCLES HAVE AMPLIFY THE PATTERN WITH THE ERN USA TROF BEING CARVED OUT AGAIN. THE 00Z EC ENSEMBLE CONTROL RUN SHOWS THIS VERY NICELY AND THIS IDEA FITS THE PATTERN. SURFACE: THE COOL FRONT THAT IS ADVANCING THRU THE FCST AREA SUN AFTERNOON WILL STALL OVER NRN KS MON...AWAITING A STRONGER SECOND FRONT THAT WILL SLIDE THRU MON NIGHT. THIS SECOND PUSH WILL FORCE THE COMPOSITE FRONT DEEPER INTO THE SRN PLAINS. COMFORTABLE HIGH PRES BUILDS IN TUE-WED WITH RETURN FLOW DEVELOPING THU AS THE HIGH HEADS INTO THE GREAT LAKES. LOW PRES WILL CROSS WRN CANADA DURING THIS TIME FRAME AND BEGIN DRAWING THE FRONT BACK N AS A WARM FRONT THU. FRI IT HEATS BACK UP IN THE WARM SECTOR...THEN A COOL FRONTAL PASSAGE FRI NIGHT OR SAT. HAZARDS: AN ISOLATED PROBABLY NON-SVR TSTM OR TWO IS POSSIBLE SUN NIGHT INTO MON. THE MAIN SHOW WILL BE MON NIGHT WITH LEGIT SVR POTENTIAL. BEYOND THAT...ANY TSTM DEVELOPMENT LOOKS UNORGANIZED AND IS LOW CONFIDENCE. THE DAILY DETAILS... UNCERTAINTY IS WAY ABOVE AVERAGE SUN NIGHT INTO MON. AM NOT IMPRESSED WITH THE TSTM POTENTIAL ALONG THIS FRONT. WHILE DEWPOINTS ARE IMPRESSIVE NOW...TOMORROW`S HEAT WILL MIX OUT THESE HIGH DWPTS WITH NO REPLENISHMENT. 12Z SOUNDINGS AROUND THE REGION THIS AM SHOW THERE ARE REALLY NO GOOD/DEEP BANDS OF MOISTURE. THIS LACK OF MOISTURE WILL MAKE IT MORE DIFFICULT TO BREAK THE CAP. 09Z SREF DOES SUGGEST PORTION OF THE NARROW RIBBON OF 10-12C 850 MB DWPTS ALONG THE FRONT WILL CIRCULATE ANTICYCLONICALLY BACK INTO THE REGION LATE SUN NIGHT INTO MON...WAITING TO INTERCEPT THE NEXT FRONT. BOTTOM LINE...MOST LOCATIONS WILL REMAIN DRY MOST OF THE TIME SUN NIGHT INTO MON. THIS FCST WOULD BETTER BE VIEWED FROM THE STANDPOINT THAT THERE IS AN 80% CHANCE THAT TSTMS WILL NOT FORM. "IF" AN ISOLATED TSTM OR TWO MANAGES TO DEVELOP...DEEP LAYER SHEAR WILL BE WEAK /10-15 KTS/. THIS SUGGESTS AT BEST NICKEL SIZE HAIL. LCL HEIGHTS WILL BE NEAR 10K FT WHICH WOULD THREATEN WIND GUSTS UP TO 50 MPH. MON NIGHT: A COOL FRONTAL PASSAGE WITH A TIGHT PRES GRADIENT BEHIND AND THE LLJ IN ADVANCE. CONSIDERABLE CONVERGENCE SHOULD RESULT IN TSTM DEVELOPMENT. THE PRECONVECTIVE ENVIRONMENT SHOULD HAVE 2000- 2500 J/KG OF MLCAPE WITH 40-45 KTS OF EFFECTIVE SHEAR. WE DO NEED TO WATCH POTENTIAL FOR INITIAL DEVELOPMENT FOR SUPERCELL POTENTIAL... BUT THE STRENGTH OF THE FORCING SHOULD RESULT IN RAPID DEVELOPMENT OF A SQUALL LINE WITH DAMAGING WIND BEING THE PRIMARY THREAT. GIVEN THE STRENGTH OF THE LOW-LEVEL SHEAR...EMBEDDED BOWS AND LEWP`S WILL BE POSSIBLE. WE HAVE NOTED THE SPC SLIGHT RISK FOR SVR WX AND WE ARE IN AGREEMENT. THIS FCSTR CONTS TO SEE TUE-THU COOLER THAN WHAT MEX MOS AND EVEN THE DAYS 4-7 INITIALIZATION HAVE BEEN ADVERTISING. THIS GUIDANCE HAS BEEN VERY RELUCTANT TO LOWER TEMPS. BASED ON ENSEMBLE TEMP ANOMALIES ...HAVE TRENDED THE FCST HIGHS CLOSER TO THE EC/GEM 2M TEMPS WHICH HAVE HAD A SIZABLE COOLDOWN FOR SEVERAL DAYS. TUE: CLEARING AS MON NIGHT`S MCS DEPARTS THE REGION. HIGHS HAVE BEEN LOWERED TO 77-86F...A LITTLE BELOW THE 4 AM GID FCST. THIS IS ROUGHLY 8F COOLER THAN NORMAL. THERE COULD BE A PERIOD OF WINDY CONDITIONS BEFORE NOON. WED: VERY NICE. TEMPS BEGIN CREEPING UP A LITTLE...BUT STILL 4-5F COOLER THAN NORMAL. WED NIGHT: GOOD LLJ DEVELOPMENT WITH A BURST OF THETA-E ADVECTION. COULD SEE A FEW SHWRS/TSTMS FORM WITH THE APPROACHING WARM FRONT. THU: QUESTIONABLE. IT ALL DEPENDS ON HOW QUICKLY WARM FRONTAL CLOUDINESS DEPARTS ALONG WITH ANY LINGERING EFFECTS FROM POSSIBLE MCS DEVELOPMENT WED NIGHT. THERE COULD ACTUALLY BE A SUBSTANTIAL TEMP GRADIENT FROM SW-NE ACROSS THE FCST AREA. WHILE AREAS FROM ORD- GREELEY-FULLERTON MAY BE JAMMED IN THE 70S...AREAS FROM BEAVER CITY- OSBORNE KS MAY BE IN THE UPPER 90S. FRI: ANOTHER THRUST OF BIG TIME HEAT IN THE WARM SECTOR. BELIEVE ODDS FAVOR 95-105F. LOOK FOR THIS TIME FRAME TO TREND HIGHER. FRI NIGHT OR SAT: POSSIBLY A COOL FRONTAL PASSAGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1237 AM CDT SUN JUL 6 2014 VFR CONDITIONS IN THE FORECAST FOR THIS TAF PERIOD...WITH THE MAIN CONCERN LYING WITH THE PASSAGE OF A SURFACE COLD FRONT. WEAK SFC PATTERN CURRENTLY IN PLACE WILL KEEP WINDS LIGHT AND VARIABLE AS WE GET PAST SUNRISE...WITH WINDS THEN STARTING TO SWITCH TO THE NW THEN N WITH TIME. EVEN WITH THE BOUNDARY PASSING THROUGH...SPEEDS ARE NOT EXPECTED TO TOP 10 TO 15 MPH. MODELS SUGGEST THE POTENTIAL FOR THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON/EVENING...BUT CONFIDENCE IN ITS IMPACT ON THE TERMINAL AREAS LOW ENOUGH NOT TO INSERT ANY MENTION AT THIS POINT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...JCB LONG TERM...HALBLAUB AVIATION...ADO
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
538 PM EDT SUN JUL 6 2014 .SYNOPSIS... AFTER WARM SUNNY CONDITIONS TODAY THE WEATHER WILL BECOME MORE UNSETTLED DURING THE EARLY PART OF THE NEXT WEEK. A SERIES OF WEAK FRONTAL BOUNDARIES WILL PASS ACROSS THE AREA STARTING MONDAY AFTERNOON BRINGING A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY FROM MONDAY INTO WEDNESDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 530 PM UPDATE... AMPED SKY GRIDS UP TO ACCOUNT FOR THICKER-THAN-EXPECTED WING OF CLOUDS EXTENDING ACROSS THE CENTRAL TWIN TIERS AT THIS TIME. INITIAL NORTHEASTERN PORTION SHOWS UP IN RUC13 RH FIELDS AROUND 500MB. THEN REMAINDER OF THICKER CLOUD SHIELD NOW SPREADING FROM WESTERN TO CENTRAL PA...SHOULD MOVE ACROSS NEPA AND PERHAPS SOME OF THE NY/PA BORDER ZONES LATER THIS EVENING AS PER 700MB RH FIELD OF THE RUC13. VIRGA IS ALSO SHOWING UP ON OUR RADAR CURRENTLY...YET LOW LEVELS ARE MUCH TOO DRY FOR IT TO REACH THE GROUND...AT LEAST INITIALLY. WITH THE WEAK SHORTWAVE INBOUND...THERE HAVE BEEN SOME SCATTERED SPRINKLES INCLUDING BRADFORD PA...THE CITY NOT THE COUNTY. I DO NOT SEE THAT GETTING MUCH PAST THE ALLEGHENY PLATEAU INCLUDING THE WIND FARMS OF BRADFORD PA...THE COUNTY NOT THE CITY...AND PERHAPS NEAR RICKETTS GLEN...AS IT ENCOUNTERS MINOR DOWNSLOPING ANYWHERE BEYOND THAT AS WELL AS CONSIDERABLE LOW LEVEL DRY AIR AND LOSS OF DAYTIME HEATING. MENTION OF SPRINKLES HAS BEEN ADDED TO THE FORECAST THIS EVENING AROUND THOSE AREAS...OTHERWISE LOOKING TOTALLY DRY /AND EVEN FOR THOSE LOCATIONS GETTING A SPRINKLE...OF LITTLE CONSEQUENCE/. PREVIOUS DISCUSSION... A WEAK SHORT WAVE WILL TRACK FROM OHIO ACROSS PENNSYLVANIA THIS EVENING. SOME CLOUDS ASSOCIATED WITH THE WAVE WILL MOVE ACROSS THE AREA... ESPECIALLY NORTHERN PA... BUT THE LOW LEVELS WILL BE TOO DRY FOR ANY PRECIPITATION. PARTLY CLOUDY SKIES WILL CONTINUE OVERNIGHT THEN CLOUDS WILL INCREASE ACROSS THE WEST TOWARD DAYBREAK MONDAY AS THE NEXT WEATHER SYSTEM APPROACHES FROM THE WEST. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... UNSETTLED WEATHER IS EXPECTED FROM MONDAY THROUGH WEDNESDAY AS A PRONOUNCED UPPER LEVEL TROUGH DEVELOPS OVER THE NORTHEAST U.S. AND EASTERN CANADA. A SERIES OF SHORT WAVES WILL SWING EAST ACROSS THE AREA DURING THIS TIME AND LOW-LEVEL MOISTURE WILL INCREASE RAPIDLY... SETTING THE STAGE FOR SHOWERS AND THUNDERSTORMS STARTING MONDAY AFTERNOON. THE FIRST SHORT WAVE TROUGH SWINGS EAST ACROSS THE AREA MONDAY AFTERNOON. THIS UPPER WAVE WILL BE ACCOMPANIED BY A RAPID INCREASE IN LOW-LEVEL MOISTURE WITH MID 60S DEW POINTS BY AFTERNOON. THE AMOUNT OF SUNSHINE MONDAY WILL PLAY A BIG ROLE IN THE INTENSITY AND COVERAGE OF CONVECTION ACROSS OUR AREA DURING THE AFTERNOON AND THERE DOES APPEAR TO BE A GOOD DEAL OF CLOUDINESS CURRENTLY UPSTREAM OVER WISCONSIN... HOWEVER AT THIS POINT WE ARE EXPECTING AT LEAST SOME SUNSHINE WHICH WOULD ALLOW CAPE VALUES TO RISE TO AROUND 1000 J/KG DURING THE AFTERNOON. 0-3 AND 0-6 KM BULK SHEAR VALUES OF 30-35 KTS WILL BE ENOUGH TO SUPPORT THE DEVELOPMENT OF ORGANIZED LINES OF CONVECTION WITH SOME SEVERE POTENTIAL. BASED ON THIS WILL KEEP THE MENTION OF DAMAGING WINDS OR LARGE HAIL IN THE HWO. PWAT VALUES ARE ALSO FORECAST TO INCREASE TO BETWEEN 1.5 AND 2.0 INCHES SO LOCALIZED HEAVY RAIN WILL ALSO BE A CONCERN MONDAY AFTERNOON INTO THE EVENING. COVERAGE SHOULD BE FAIRLY EXTENSIVE AND WE ARE GOING WITH POPS AROUND 70 PERCENT FROM AFTERNOON THROUGH EARLY EVENING. AFTER A LULL MONDAY NIGHT INTO EARLY TUESDAY ANOTHER SHORT WAVE WILL SWING ACROSS THE AREA LATE TUESDAY INTO TUESDAY NIGHT. WITH THE MOIST AIRMASS IN PLACE EXPECT ONCE AGAIN THAT CAPE VALUES WILL CLIMB TO NEAR OR JUST ABOVE 1000 J/KG TUESDAY AFTERNOON WITH THE APPROACHING SHORT WAVE TROUGH AT THE SURFACE AND ALOFT ONCE AGAIN TRIGGERING SHOWERS AND THUNDERSTORMS. DEEP LAYER SHEAR VALUES APPEAR TO BE AT LEAST AS LARGE ON TUESDAY AS MONDAY AND ONCE AGAIN THERE WILL BE SOME SEVERE AND HEAVY RAIN POTENTIAL WITH THESE STORMS INTO TUESDAY EVENING. THE MAIN SURFACE FRONTAL BOUNDARY SHOULD BE EAST OF THE AREA ON WEDNESDAY WITH LOWERING DEW POINTS. THE UPPER TROUGH WILL BE ONLY SLOWLY PROGRESSING EAST ACROSS THE GREAT LAKES AND A FEW SHOWERS MAY YET DEVELOP WEDNESDAY AFTERNOON... BUT POPS WILL BE LOWER THAN MONDAY OR TUESDAY AND THE SEVERE AND HEAVY RAIN POTENTIAL WILL BE LOWER DUE TO LOWER DEW POINTS AND LESS INSTABILITY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... 230 PM SUN UPDATE... ON THE LARGE-SCALE...WRN CONUS/WRN CANADIAN RIDGING AND A L/WV TROUGH FROM HUDSON`S BAY SWD OVER THE ERN CONUS WILL SET THE PATN THIS PD. HOW AMPLIFIED THIS CONFIGURATION IS...THOUGH WILL VARY OVER TIME. IN GENERAL...THIS TRANSLATES TO AN ABSENCE OF ANY TRULY HOT WX (HIGHS FROM THE 70S-MID 80S)...WITH ROUNDS OF CONVECTION ROLLING THROUGH ABT EVERY 2-3 DAYS. AS FOR THE DAILY SENSIBLE WX...LINGERING SHWRS/TSTMS ARE PSBL AT THE START OF THE PD WED NGT-THU...AS A NRN STREAM S/WV AND SFC COLD FRNT SLOWLY PUSH OFF THE EAST COAST. FRI THROUGH MOST OF SAT LOOK RAIN-FREE AT THIS EARLY VANTAGE PT...WITH THE ERN TROUGH TEMPORARILY RELAXING. FOR THE LATTER PTN OF NEXT WEEKEND...SHWRS AND TSTMS MAY WELL RETURN...AS A RELOADING OF THE L/WV TROUGH AXIS UPSTREAM HERALDS THE APPROACH OF OUR NEXT S/WV...ALG WITH A SFC WARM FRNT. && .AVIATION /22Z SUNDAY THROUGH FRIDAY/... 18Z SUN UPDATE... VFR EXPECTED THROUGH 18Z MON. SOME SHWRS ARE ANTICIPATED MON MRNG...AFTER 12-14Z...BUT THEY SHOULD REMAIN UNRESTRICTED IN NATURE. W TO SW SFC WINDS 5-10 KT THIS AFTN...WILL BECOME SRLY OVERNIGHT...THEN INCREASE AND BECOME GUSTY OUT OF THE SW AFTER 14-15Z MON (GUSTS OF 20-25 KT LIKELY). OUTLOOK... TUE THROUGH THU...ALTHOUGH VFR IS LIKELY THE MAJORITY OF THE TIME...THERE WILL BE SHWRS AND TSTMS IN THE VICINITY...SPCLY DURG THE AFTN AND EVE HRS. BRIEF RESTRICTIONS MAY OCCUR. FRI...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP/MSE NEAR TERM...MDP/MSE SHORT TERM...MSE LONG TERM...MLJ AVIATION...MLJ
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
518 AM EDT SUN JUL 6 2014 .SYNOPSIS... MID AND HIGH LEVEL CLOUDS WILL MOVE ACROSS THE AREA TODAY ALTHOUGH RAIN CHANCES WILL BE MINIMAL. MORE TYPICAL SUMMERTIME WEATHER WILL DEVELOP MONDAY THROUGH WEDNESDAY ALTHOUGH THUNDERSTORM CHANCES WILL REMAIN QUITE LOW. RAIN CHANCES INCREASE INTO LATE WEEK THROUGH NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 345 AM SUNDAY...MODELS IDENTIFY THE WEAK LOW-MID LEVEL S/W TROF OR VORT MAX OFF THE FL-GA COASTS THIS MORNING...AND LIFT IT TO THE N-NE...MORE OR LESS PARALLEL TO THE SE U.S. COASTLINE...TO THE NC ATL WATERS NC BETWEEN CAPE LOOKOUT AND CAPE FEAR AROUND DAYBREAK MONDAY. THE MAIN PROBLEM FOR THIS NEAR TERM PERIOD WILL BE HOW FAR INLAND WILL THE ASSOCIATED MOISTURE...IE. CLOUDS AND PCPN...EXTEND. THE NAM SEEMS MUCH MORE WETTER THAN THE GFS...ALONG WITH A FURTHER EXTENSION INLAND WITH ITS POPS...IE LOOK AT THE LATEST NAM MOS GUIDANCE. HOWEVER...THE CURRENT CLOUD FIELD SHOWS MAINLY A THIN/OPAQUE CI SHIELD ACROSS THE FA WITH POSSIBLE LOW-MID CLOUDS ACROSS THE SOUTHERN PORTIONS OF GEORGETOWN COUNTY VIA LATEST 11-3.9 MICRON SAT IMAGERY. WILL LEAN TOWARD THE GFS MOS POP OUTPUT...WITH A LESS EXTENSION INLAND WITH POPS AND ALSO WITH THE LOW- MID LEVEL CLOUDS. IN ESSENCE...WILL GO WITH A MAX OF 20-40 POPS ACROSS THE IMMEDIATE COAST AS THIS DISTURBANCE FEATURE ALOFT MAKES ITS WAY TO THE N-NE. NOT ONE OF YOUR BETTER BEACH DAYS WITH THIN-OPAQUE HIGH LEVEL CLOUDINESS OCCURRING...AND WITH INCREASING LOW-MID LEVEL CLOUD DECKS DURING THE DAY. MAX TEMPS OF WIDESPREAD 80S TO OCCUR ACROSS THE ENTIRE FA...WITH THE OPAQUE CI/CS AND ADDITIONAL LOW- MID LEVEL CLOUDS KEEPING MAXES NEARLY A CATEGORY LOWER...IE. THE IMMEDIATE COAST. TONIGHTS MIN TEMPS IN THE MID TO UPPER 60S...70-75 ALONG THE IMMEDIATE COAST DUE TO ONSHORE FLOW ACROSS SSTS AROUND 80. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 AM SUNDAY...MID LEVEL SYSTEM THAT WILL PROVIDE CLOUDINESS TODAY WILL MOVE OFF TO THE NORTHEAST MONDAY. NVA IN THE WAKE OF THIS SYSTEM SHOULD PRECLUDE ANY CONVECTION BUT THIS TIME OF YEAR WITH STRONG DAYTIME HEATING ITS TOUGH TO KEEP THE FORECAST ENTIRELY DRY. WE ARE STILL ADVERTISING POPS FOR MONDAY WITH TUESDAY DRY. TEMPERATURE FORECAST REMAINS STABLE WITH A FEW DEGREES TACKED ON TO THE 88-93 RANGE MONDAY FOR TUESDAY. OVERNIGHT LOWS IN THE 60S WILL BE HISTORY WITH LOWER TO MIDDLE 70S AREA WIDE. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 330 AM SUNDAY...OVERALL THE MID LEVEL PATTERN HAS TRENDED SLIGHTLY TOWARD A BIT MORE OF AN ELONGATED RIDGE LATER IN THE PERIOD ALTHOUGH THIS APPEARS TO HAVE LITTLE IMPACT ON THE SENSIBLE WEATHER ELEMENTS FOR OUR LOCAL AREA. THE TROUGH ACROSS THE MIDWEST WEAKENS MORESO INSTEAD OF MOVING EAST AND THIS KEEPS THE ASSOCIATED FRONTS FROM PASSING ACROSS THE AREA. THE LATEST WPC GRAPHICS SHOW A FRONT ACROSS THE AREA EARLY SATURDAY WHICH WILL REMAIN THE CATALYST FOR GOOD CHANCES OF SHOWERS THEN DISSIPATING BY THE NEW DAY SUNDAY. FRIDAY REMAINS ON TRACK FOR GOOD COVERAGE OF CONVECTION AS WELL. WEDNESDAY AND THURSDAY WILL SEE ISOLATED TO CHANCE COVERAGE. NO CHANGES TO THE PREVIOUS TEMPERATURE FORECAST. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... AS OF 06Z...EXPECT VFR CONDITIONS TO PERSIST THROUGH THE TAF PERIOD. SURFACE OBS AND LATEST SAT IMAGERY ACROSS SOUTH CAROLINA SUGGEST SOME 3-4KFT CLOUDS ARE MAKING THEIR WAY ONSHORE KMYR/KCRE...BUT CIGS SHOULD REMAIN VFR OVERNIGHT VIA LATEST MODEL RUNS. HAVE INTRODUCED VCSH FOR KMYR/KCRE LATER TODAY AS AN UPPER DISTURBANCE OFF THE GA/SC COAST LIFTS NORTHWARD. DO NOT EXPECT MORE THAN TEMPO -SHRA/MVFR AT WORST...BUT COVERAGE WILL BE SO ISOLATED THAT THESE TERMS MAY NOT SEE ANY PCPN AT ALL. THE OTHER TAF SITES LOOK TO REMAIN DRY TODAY AS THE BULK OF THE PCPN WILL REMAIN OFFSHORE. EAST WINDS AROUND 5 KTS THIS MORNING WILL BECOME SOUTHEAST 10-15 KT AT THE COAST...5 TO 10 KT INLAND AFTER 17Z AS HIGH PRESSURE MOVES FURTHER OFF THE ATLANTIC COAST. VFR WILL CONTINUE INTO THE EVENING HOURS AS WINDS BECOME LIGHT/VRB. EXTENDED OUTLOOK...VFR WILL PREVAIL THROUGH THE EXTENDED PERIOD. SLIGHT CHANCE OF SHOWERS/TSTMS WEDNESDAY AND THURSDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 PM SATURDAY...THE LIMITED MARINE DATA AVAILABLE CONFIRMS OUR EARLIER FORECAST AND NO SIGNIFICANT CHANGES ARE NEEDED TO WINDS OR SEAS. THE NEW 00Z NAM MODEL PLUS SEVERAL OF THE RECENT RUNS OF THE HRRR MODEL SUGGEST THE POTENTIAL FOR SHOWERS AROUND SUNRISE MAY BE RISING IN THE GEORGETOWN/WINYAH BAY VICINITY AND OFFSHORE. ALSO OF NOTE OUR LOCAL WATERSPOUT THREAT CALCULATOR HAS INCREASED THAT POTENTIAL INTO THE "MODERATE" CATEGORY FOR SUNDAY. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS... 1024 MB HIGH PRESSURE CENTERED OVER WESTERN VIRGINIA IS PRODUCING AN ONSHORE WIND ACROSS MOST OF THE COASTAL SOUTHEAST THIS EVENING. A WEAK AREA OF LOW PRESSURE ASSOCIATED WITH AN ODD MID AND UPPER-LEVEL DISTURBANCE ALONG THE GEORGIA COAST IS HELPING ACCELERATE THE ONSHORE WINDS WITH SUSTAINED SPEEDS AS HIGH AS 20 KNOTS BEING REPORTED NEARSHORE FROM MYRTLE BEACH SOUTHWARD INTO THE CHARLESTON VICINITY. THESE WIND SPEEDS SHOULD GRADUALLY DIMINISH OVERNIGHT...ESPECIALLY ACROSS THE NC WATERS WHERE THE HIGH WILL BUILD DOWN AND SPREAD ITS LESSENED PRESSURE GRADIENT OVERHEAD. A LITTLE TIGHTER PRESSURE GRADIENT SHOULD CONTINUE OVER THE SOUTH CAROLINA WATERS AND THAT IS WHERE MY HIGHEST FORECAST WIND SPEEDS WILL REMAIN. AN EARLIER UPDATE LATE THIS AFTERNOON BROUGHT NEARSHORE SEAS INTO ALIGNMENT WITH THE ONSHORE WINDS...AND NO FURTHER SIGNIFICANT CHANGES ARE NEEDED. THE NEARSHORE WRIGHTSVILLE BEACH BUOY IS REPORTING A 3.4 FT CHOP EVERY 5 SECONDS...WITH NOAA BUOY 41004 40 MILES SOUTHEAST OF CHARLESTON REPORTING A VERY CHOPPY 7 FEET EVERY 5-6 SECONDS. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 330 AM SUNDAY...A FAIRLY BRISK SOUTHWEST FLOW OF 15-20 KNOTS WILL PREVAIL ACROSS THE WATERS THROUGH THE PERIOD. THE FLOW MAY DIP BELOW 15 KNOTS BRIEFLY BUT OVERALL THIS RANGE SHOULD SUFFICE. THE PRIMARY REASON IS THE DEVELOPMENT OF THE PIEDMONT TROUGH. SEAS SHOULD REMAIN CONFINED TO A 2-4 FOOT RANGE. LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 330 AM SUNDAY...SOUTH TO SOUTHWEST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS WITH THE STRONGEST WINDS OCCURRING WEDNESDAY. THESE SPEEDS WILL BE 15-20 KNOTS AS A FRONT SLOWLY APPROACHES FROM THE NORTHWEST THUS INCREASING THE GRADIENT. A GRADUAL WEAKENING OF THE FRONT AND SUBSEQUENT SPEEDS OCCUR THURSDAY. SIGNIFICANT SEAS WILL BE HIGHER WEDNESDAY WITH 2-4 FEET DROPPING OT 2-3 FEET THURSDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...DCH SHORT TERM...SHK LONG TERM...SHK AVIATION...DCH/BJR MARINE...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
329 AM EDT SUN JUL 6 2014 .SYNOPSIS... MID AND HIGH LEVEL CLOUDS WILL MOVE ACROSS THE AREA TODAY ALTHOUGH RAIN CHANCES WILL BE MINIMAL. MORE TYPICAL SUMMERTIME WEATHER WILL DEVELOP MONDAY THROUGH WEDNESDAY ALTHOUGH THUNDERSTORM CHANCES WILL REMAIN QUITE LOW. RAIN CHANCES INCREASE INTO LATE WEEK THROUGH NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1030 PM SATURDAY...MAINLY THIN CIRRUS IS STREAMING OVERHEAD THIS EVENING...BUT THE INFRARED SATELLITE PRESENTATION IS QUITE A BIT WORSE THAN IT LOOKS FROM THE OFFICE PARKING LOT. THE ONLY LOCATION IN OUR FORECAST AREA WITH LOWER CLOUDS BENEATH THE CIRRUS IS GEORGETOWN WHERE CLOUDS WITH BASES JUST ABOVE 3000 FEET (PRESUMABLY MARITIME CUMULUS) ARE BEING REPORTED ON THE GGE AWOS. THE NEW 00Z NAM CONCURS WITH RECENT HRRR RUNS THAT MARINE SHOWERS MAY ATTEMPT TO SPREAD ONSHORE IN THE GEORGETOWN VICINITY AROUND SUNRISE...SO I HAVE UPPED POPS SLIGHTLY IN THE 11-15Z TIME FRAME THERE. OTHERWISE NO SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS... HIGH PRESSURE OVER WESTERN VIRGINIA WILL BUILD SOUTHEASTWARD OVERNIGHT...SETTLING ACROSS EASTERN NORTH CAROLINA BEFORE DAYBREAK. TO THE SOUTH A SEEMINGLY OUT-OF-PLACE UPPER LEVEL DISTURBANCE OFF THE GEORGIA COAST IS IGNITING QUITE A BIT OF THUNDERSTORM ACTIVITY FROM SOUTHERN SOUTH CAROLINA TO THE FLORIDA EAST COAST. CONVECTIVE BLOWOFF CLOUDINESS STREAMING NORTHWARD HAS PROVIDED A BIT MORE CLOUD COVER THAN EARLIER ANTICIPATED ACROSS NORTHEASTERN SOUTH CAROLINA INCLUDING GEORGETOWN AND MYRTLE BEACH. WHILE MUCH OF THE LOWER CUMULUS CLOUD COVER THAT DEVELOPED DURING THE HEAT OF THE AFTERNOON WILL DISSIPATE THIS EVENING...THIS HIGHER CONVECTIVE BLOWOFF MAY PERSIST. AS THE WEAK UPPER DISTURBANCE DRIFTS NORTHWARD...ATLANTIC MOISTURE WILL INCREASE ALONG THE BASE OF A SIGNIFICANT SUBSIDENCE INVERSION BETWEEN 775-700 MB...APPROXIMATELY 7500-10500 FEET ABOVE GROUND LEVEL. THIS MAY SPELL INCREASING CLOUD COVER AFTER MIDNIGHT ESPECIALLY ACROSS NORTHEASTERN SOUTH CAROLINA WHERE CONDITIONS MAY TEMPORARILY CLEAR OUT LATER THIS EVENING. WITH FAIRLY STEEP LAPSE RATES BENEATH THE SUBSIDENCE INVERSION IT IS EVEN POSSIBLE NOCTURNAL MARINE CONVECTION DEVELOPING OVER THE SHALLOW INSTABILITY OFFSHORE WILL ADVECT WESTWARD...WITH SHOWER CHANCES DEVELOPING ALONG THE SC COAST SOUTH OF MYRTLE BEACH. LOW TEMPERATURES WILL HAVE A PRONOUNCED NORTH-SOUTH GRADIENT TONIGHT. ACROSS INTERIOR SE NORTH CAROLINA GOOD RADIATIONAL COOLING AND A PREEXISTING COOL/DRY AIRMASS SHOULD ALLOW TEMPERATURES TO FALL INTO 61-65 RANGE...IN PLACES ALMOST 10 DEGREES BELOW NORMAL. ACROSS NE SOUTH CAROLINA MORE CLOUDS AND A HEALTHIER ONSHORE WIND WILL PRECLUDE EFFICIENT RADIATIONAL COOLING WITH LOWS GENERALLY IN THE UPPER 60S TO AROUND 70...WARMEST NEAR THE COAST. && .SHORT TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM SUNDAY...MID LEVEL SYSTEM THAT WILL PROVIDE CLOUDINESS TODAY WILL MOVE OFF TO THE NORTHEAST MONDAY. NVA IN THE WAKE OF THIS SYSTEM SHOULD PRECLUDE ANY CONVECTION BUT THIS TIME OF YEAR WITH STRONG DAYTIME HEATING ITS TOUGH TO KEEP THE FORECAST ENTIRELY DRY. WE ARE STILL ADVERTISING POPS FOR MONDAY WITH TUESDAY DRY. TEMPERATURE FORECAST REMAINS STABLE WITH A FEW DEGREES TACKED ON TO THE 88-93 RANGE MONDAY FOR TUESDAY. OVERNIGHT LOWS IN THE 60S WILL BE HISTORY WITH LOWER TO MIDDLE 70S AREA WIDE. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 330 AM SUNDAY...OVERALL THE MID LEVEL PATTERN HAS TRENDED SLIGHTLY TOWARD A BIT MORE OF AN ELONGATED RIDGE LATER IN THE PERIOD ALTHOUGH THIS APPEARS TO HAVE LITTLE IMPACT ON THE SENSIBLE WEATHER ELEMENTS FOR OUR LOCAL AREA. THE TROUGH ACROSS THE MIDWEST WEAKENS MORESO INSTEAD OF MOVING EAST AND THIS KEEPS THE ASSOCIATED FRONTS FROM PASSING ACROSS THE AREA. THE LATEST WPC GRAPHICS SHOW A FRONT ACROSS THE AREA EARLY SATURDAY WHICH WILL REMAIN THE CATALYST FOR GOOD CHANCES OF SHOWERS THEN DISSIPATING BY THE NEW DAY SUNDAY. FRIDAY REMAINS ON TRACK FOR GOOD COVERAGE OF CONVECTION AS WELL. WEDNESDAY AND THURSDAY WILL SEE ISOLATED TO CHANCE COVERAGE. NO CHANGES TO THE PREVIOUS TEMPERATURE FORECAST. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... AS OF 06Z...EXPECT VFR CONDITIONS TO PERSIST THROUGH THE TAF PERIOD. SURFACE OBS AND LATEST SAT IMAGERY ACROSS SOUTH CAROLINA SUGGEST SOME 3-4KFT CLOUDS ARE MAKING THEIR WAY ONSHORE KMYR/KCRE...BUT CIGS SHOULD REMAIN VFR OVERNIGHT VIA LATEST MODEL RUNS. HAVE INTRODUCED VCSH FOR KMYR/KCRE LATER TODAY AS AN UPPER DISTURBANCE OFF THE GA/SC COAST LIFTS NORTHWARD. DO NOT EXPECT MORE THAN TEMPO -SHRA/MVFR AT WORST...BUT COVERAGE WILL BE SO ISOLATED THAT THESE TERMS MAY NOT SEE ANY PCPN AT ALL. THE OTHER TAF SITES LOOK TO REMAIN DRY TODAY AS THE BULK OF THE PCPN WILL REMAIN OFFSHORE. EAST WINDS AROUND 5 KTS THIS MORNING WILL BECOME SOUTHEAST 10-15 KT AT THE COAST...5 TO 10 KT INLAND AFTER 17Z AS HIGH PRESSURE MOVES FURTHER OFF THE ATLANTIC COAST. VFR WILL CONTINUE INTO THE EVENING HOURS AS WINDS BECOME LIGHT/VRB. EXTENDED OUTLOOK...VFR WILL PREVAIL THROUGH THE EXTENDED PERIOD. SLIGHT CHANCE OF SHOWERS/TSTMS WEDNESDAY AND THURSDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 PM SATURDAY...THE LIMITED MARINE DATA AVAILABLE CONFIRMS OUR EARLIER FORECAST AND NO SIGNIFICANT CHANGES ARE NEEDED TO WINDS OR SEAS. THE NEW 00Z NAM MODEL PLUS SEVERAL OF THE RECENT RUNS OF THE HRRR MODEL SUGGEST THE POTENTIAL FOR SHOWERS AROUND SUNRISE MAY BE RISING IN THE GEORGETOWN/WINYAH BAY VICINITY AND OFFSHORE. ALSO OF NOTE OUR LOCAL WATERSPOUT THREAT CALCULATOR HAS INCREASED THAT POTENTIAL INTO THE "MODERATE" CATEGORY FOR SUNDAY. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS... 1024 MB HIGH PRESSURE CENTERED OVER WESTERN VIRGINIA IS PRODUCING AN ONSHORE WIND ACROSS MOST OF THE COASTAL SOUTHEAST THIS EVENING. A WEAK AREA OF LOW PRESSURE ASSOCIATED WITH AN ODD MID AND UPPER-LEVEL DISTURBANCE ALONG THE GEORGIA COAST IS HELPING ACCELERATE THE ONSHORE WINDS WITH SUSTAINED SPEEDS AS HIGH AS 20 KNOTS BEING REPORTED NEARSHORE FROM MYRTLE BEACH SOUTHWARD INTO THE CHARLESTON VICINITY. THESE WIND SPEEDS SHOULD GRADUALLY DIMINISH OVERNIGHT...ESPECIALLY ACROSS THE NC WATERS WHERE THE HIGH WILL BUILD DOWN AND SPREAD ITS LESSENED PRESSURE GRADIENT OVERHEAD. A LITTLE TIGHTER PRESSURE GRADIENT SHOULD CONTINUE OVER THE SOUTH CAROLINA WATERS AND THAT IS WHERE MY HIGHEST FORECAST WIND SPEEDS WILL REMAIN. AN EARLIER UPDATE LATE THIS AFTERNOON BROUGHT NEARSHORE SEAS INTO ALIGNMENT WITH THE ONSHORE WINDS...AND NO FURTHER SIGNIFICANT CHANGES ARE NEEDED. THE NEARSHORE WRIGHTSVILLE BEACH BUOY IS REPORTING A 3.4 FT CHOP EVERY 5 SECONDS...WITH NOAA BUOY 41004 40 MILES SOUTHEAST OF CHARLESTON REPORTING A VERY CHOPPY 7 FEET EVERY 5-6 SECONDS. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 330 AM SUNDAY...A FAIRLY BRISK SOUTHWEST FLOW OF 15-20 KNOTS WILL PREVAIL ACROSS THE WATERS THROUGH THE PERIOD. THE FLOW MAY DIP BELOW 15 KNOTS BRIEFLY BUT OVERALL THIS RANGE SHOULD SUFFICE. THE PRIMARY REASON IS THE DEVELOPMENT OF THE PIEDMONT TROUGH. SEAS SHOULD REMAIN CONFINED TO A 2-4 FOOT RANGE. LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 330 AM SUNDAY...SOUTH TO SOUTHWEST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS WITH THE STRONGEST WINDS OCCURRING WEDNESDAY. THESE SPEEDS WILL BE 15-20 KNOTS AS A FRONT SLOWLY APPROACHES FROM THE NORTHWEST THUS INCREASING THE GRADIENT. A GRADUAL WEAKENING OF THE FRONT AND SUBSEQUENT SPEEDS OCCUR THURSDAY. SIGNIFICANT SEAS WILL BE HIGHER WEDNESDAY WITH 2-4 FEET DROPPING OT 2-3 FEET THURSDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...TRA SHORT TERM...SHK LONG TERM...SHK AVIATION...DCH/BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
143 AM EDT SUN JUL 6 2014 .SYNOPSIS... DRIER THAN NORMAL CONDITIONS AND FAIR WEATHER CAN BE EXPECTED THROUGH SUNDAY AS CANADIAN HIGH PRESSURE SETTLES OVER THE AREA. THE HIGH WILL MOVE OFFSHORE AND ANCHOR OVER THE WESTERN ATLANTIC ALLOWING HEAT AND HUMIDITY TO RETURN MUCH OF THE UPCOMING WEEK. GRADUALLY DEEPENING LOW PRESSURE ALONG THE PIEDMONT AND SANDHILLS OF THE CAROLINAS...WILL LED TO AN INCREASE IN THUNDERSTORMS THROUGH THE WEEK...MAINLY DURING THE AFTERNOONS AND EVENINGS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1030 PM SATURDAY...MAINLY THIN CIRRUS IS STREAMING OVERHEAD THIS EVENING...BUT THE INFRARED SATELLITE PRESENTATION IS QUITE A BIT WORSE THAN IT LOOKS FROM THE OFFICE PARKING LOT. THE ONLY LOCATION IN OUR FORECAST AREA WITH LOWER CLOUDS BENEATH THE CIRRUS IS GEORGETOWN WHERE CLOUDS WITH BASES JUST ABOVE 3000 FEET (PRESUMABLY MARITIME CUMULUS) ARE BEING REPORTED ON THE GGE AWOS. THE NEW 00Z NAM CONCURS WITH RECENT HRRR RUNS THAT MARINE SHOWERS MAY ATTEMPT TO SPREAD ONSHORE IN THE GEORGETOWN VICINITY AROUND SUNRISE...SO I HAVE UPPED POPS SLIGHTLY IN THE 11-15Z TIME FRAME THERE. OTHERWISE NO SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS... HIGH PRESSURE OVER WESTERN VIRGINIA WILL BUILD SOUTHEASTWARD OVERNIGHT...SETTLING ACROSS EASTERN NORTH CAROLINA BEFORE DAYBREAK. TO THE SOUTH A SEEMINGLY OUT-OF-PLACE UPPER LEVEL DISTURBANCE OFF THE GEORGIA COAST IS IGNITING QUITE A BIT OF THUNDERSTORM ACTIVITY FROM SOUTHERN SOUTH CAROLINA TO THE FLORIDA EAST COAST. CONVECTIVE BLOWOFF CLOUDINESS STREAMING NORTHWARD HAS PROVIDED A BIT MORE CLOUD COVER THAN EARLIER ANTICIPATED ACROSS NORTHEASTERN SOUTH CAROLINA INCLUDING GEORGETOWN AND MYRTLE BEACH. WHILE MUCH OF THE LOWER CUMULUS CLOUD COVER THAT DEVELOPED DURING THE HEAT OF THE AFTERNOON WILL DISSIPATE THIS EVENING...THIS HIGHER CONVECTIVE BLOWOFF MAY PERSIST. AS THE WEAK UPPER DISTURBANCE DRIFTS NORTHWARD...ATLANTIC MOISTURE WILL INCREASE ALONG THE BASE OF A SIGNIFICANT SUBSIDENCE INVERSION BETWEEN 775-700 MB...APPROXIMATELY 7500-10500 FEET ABOVE GROUND LEVEL. THIS MAY SPELL INCREASING CLOUD COVER AFTER MIDNIGHT ESPECIALLY ACROSS NORTHEASTERN SOUTH CAROLINA WHERE CONDITIONS MAY TEMPORARILY CLEAR OUT LATER THIS EVENING. WITH FAIRLY STEEP LAPSE RATES BENEATH THE SUBSIDENCE INVERSION IT IS EVEN POSSIBLE NOCTURNAL MARINE CONVECTION DEVELOPING OVER THE SHALLOW INSTABILITY OFFSHORE WILL ADVECT WESTWARD...WITH SHOWER CHANCES DEVELOPING ALONG THE SC COAST SOUTH OF MYRTLE BEACH. LOW TEMPERATURES WILL HAVE A PRONOUNCED NORTH-SOUTH GRADIENT TONIGHT. ACROSS INTERIOR SE NORTH CAROLINA GOOD RADIATIONAL COOLING AND A PREEXISTING COOL/DRY AIRMASS SHOULD ALLOW TEMPERATURES TO FALL INTO 61-65 RANGE...IN PLACES ALMOST 10 DEGREES BELOW NORMAL. ACROSS NE SOUTH CAROLINA MORE CLOUDS AND A HEALTHIER ONSHORE WIND WILL PRECLUDE EFFICIENT RADIATIONAL COOLING WITH LOWS GENERALLY IN THE UPPER 60S TO AROUND 70...WARMEST NEAR THE COAST. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/... AS OF 320 PM SATURDAY...ANOTHER DAY WITH RELATIVELY LOW HUMIDITY WILL PREVAIL SUNDAY BEFORE THE CANADIAN HIGH MIGRATES OFFSHORE SUNDAY NIGHT AND INCREASING SOUTHERLY FLOW BEGINS TO DEVELOP INTO MONDAY. MONDAY WILL BE A WARMER AND MORE HUMID DAY THAN SUNDAY DUE TO VEERING WINDS AND THE USHERING OF A MORE TYPICAL SUMMER TIME AIR-MASS INTO THE CAROLINAS. ON AVERAGE MAXIMUM TEMPS MONDAY LOOKS TO PAN OUT 4-7 DEGREES WARMER THAN SUNDAY. AN UPPER DISTURBANCE IN VICINITY OF A STALLED FRONTAL BOUNDARY OVER GA/SC MAY PRODUCE A FEW SHOWERS OVER OUR VERY SOUTHERN COAST AND COASTAL INTERIOR TO NEAR CAPE FEAR SUNDAY. DRY AIR ALOFT OVER THE REGION WILL SIGNIFICANTLY LIMIT THE EXTENT OF EXPECTED PCPN AND CELL COVERAGE...AND ONLY ISOLATED POP VALUES WILL BE ADVERTISED FOR THE SC ZONES. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... AS OF 320 PM SATURDAY...ANTICIPATE A FAIRLY DRY AND QUIET START TO THE PERIOD AS A WEAK UPPER LEVEL PATTERN REMAINS IN PLACE FOR TUESDAY INTO EARLY WEDNESDAY...WITH HIGHS ON BOTH DAYS IN THE MID TO UPPER 90S INLAND/LOWER 90S ALONG THE COAST WITH THE AFTERNOON SEA BREEZE...AND OVERNIGHT LOWS IN THE LOW TO MID 70S. PATTERN BEGINS TO CHANGE WEDNESDAY INTO THURSDAY AS AN UPPER LEVEL TROUGH BEGINS TO DIG SOUTH ACROSS THE EASTERN US WITH AN ASSOCIATED COLD FRONT SLOWLY PROGRESSING TOWARDS THE CAROLINAS WITH THE AID OF A HIGH PRESSURE WELL TO THE NORTHWEST . TRICKY PART OF THE FORECAST WILL BE THE PROGRESSION OF THE FRONT AND WHETHER IT STALLS AND FIZZLES WEST OF THE FORECAST AREA...OR IF IT REACHES THE FORECAST AREA AND STALLS. OVERALL...HAVE DECIDED TO KEEP WITH A NON-FRONTAL PASSAGE EVENT...BUT RATHER HAVING IT STALL/FALL JUST SHORT TO OUR WEST. WITH THAT SAID...HAVE SLIGHTLY INCREASED CLOUD COVER/POPS AND KEPT INCREASING CHANCES FOR ISOLATED TO SCATTERED THUNDERSTORMS THROUGH THE REST OF THE WEEK ACROSS THE ENTIRE FORECAST AREA AS MOISTURE INCREASES...WITH PRECIPITABLE WATER VALUES NEARING 2 INCHES OR SLIGHTLY MORE. AS FOR TEMPS WE WILL COOL DOWN SLIGHTLY ON FRIDAY AND SATURDAY WITH HIGHS IN THE UPPER 80S/LOWER 90S AND OVERNIGHT LOWS IN THE LOWER 70S. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 06Z...EXPECT VFR CONDITIONS TO PERSIST THROUGH THE TAF PERIOD. SURFACE OBS AND LATEST SAT IMAGERY ACROSS SOUTH CAROLINA SUGGEST SOME 3-4KFT CLOUDS ARE MAKING THEIR WAY ONSHORE KMYR/KCRE...BUT CIGS SHOULD REMAIN VFR OVERNIGHT VIA LATEST MODEL RUNS. HAVE INTRODUCED VCSH FOR KMYR/KCRE LATER TODAY AS AN UPPER DISTURBANCE OFF THE GA/SC COAST LIFTS NORTHWARD. DO NOT EXPECT MORE THAN TEMPO -SHRA/MVFR AT WORST...BUT COVERAGE WILL BE SO ISOLATED THAT THESE TERMS MAY NOT SEE ANY PCPN AT ALL. THE OTHER TAF SITES LOOK TO REMAIN DRY TODAY AS THE BULK OF THE PCPN WILL REMAIN OFFSHORE. EAST WINDS AROUND 5 KTS THIS MORNING WILL BECOME SOUTHEAST 10-15 KT AT THE COAST...5 TO 10 KT INLAND AFTER 17Z AS HIGH PRESSURE MOVES FURTHER OFF THE ATLANTIC COAST. VFR WILL CONTINUE INTO THE EVENING HOURS AS WINDS BECOME LIGHT/VRB. EXTENDED OUTLOOK...VFR WILL PREVAIL THROUGH THE EXTENDED PERIOD. SLIGHT CHANCE OF SHOWERS/TSTMS WEDNESDAY AND THURSDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 PM SATURDAY...THE LIMITED MARINE DATA AVAILABLE CONFIRMS OUR EARLIER FORECAST AND NO SIGNIFICANT CHANGES ARE NEEDED TO WINDS OR SEAS. THE NEW 00Z NAM MODEL PLUS SEVERAL OF THE RECENT RUNS OF THE HRRR MODEL SUGGEST THE POTENTIAL FOR SHOWERS AROUND SUNRISE MAY BE RISING IN THE GEORGETOWN/WINYAH BAY VICINITY AND OFFSHORE. ALSO OF NOTE OUR LOCAL WATERSPOUT THREAT CALCULATOR HAS INCREASED THAT POTENTIAL INTO THE "MODERATE" CATEGORY FOR SUNDAY. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS... 1024 MB HIGH PRESSURE CENTERED OVER WESTERN VIRGINIA IS PRODUCING AN ONSHORE WIND ACROSS MOST OF THE COASTAL SOUTHEAST THIS EVENING. A WEAK AREA OF LOW PRESSURE ASSOCIATED WITH AN ODD MID AND UPPER-LEVEL DISTURBANCE ALONG THE GEORGIA COAST IS HELPING ACCELERATE THE ONSHORE WINDS WITH SUSTAINED SPEEDS AS HIGH AS 20 KNOTS BEING REPORTED NEARSHORE FROM MYRTLE BEACH SOUTHWARD INTO THE CHARLESTON VICINITY. THESE WIND SPEEDS SHOULD GRADUALLY DIMINISH OVERNIGHT...ESPECIALLY ACROSS THE NC WATERS WHERE THE HIGH WILL BUILD DOWN AND SPREAD ITS LESSENED PRESSURE GRADIENT OVERHEAD. A LITTLE TIGHTER PRESSURE GRADIENT SHOULD CONTINUE OVER THE SOUTH CAROLINA WATERS AND THAT IS WHERE MY HIGHEST FORECAST WIND SPEEDS WILL REMAIN. AN EARLIER UPDATE LATE THIS AFTERNOON BROUGHT NEARSHORE SEAS INTO ALIGNMENT WITH THE ONSHORE WINDS...AND NO FURTHER SIGNIFICANT CHANGES ARE NEEDED. THE NEARSHORE WRIGHTSVILLE BEACH BUOY IS REPORTING A 3.4 FT CHOP EVERY 5 SECONDS...WITH NOAA BUOY 41004 40 MILES SOUTHEAST OF CHARLESTON REPORTING A VERY CHOPPY 7 FEET EVERY 5-6 SECONDS. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 320 PM SATURDAY...ONSHORE ENE-E WINDS SUNDAY MORNING WILL RESULT IN BUMPY 3-4 FOOT SEAS FOR THE MOST PART...BUT AS WINDS GO SE AND S INTO AFTERNOON AND EVENING...SEAS WILL LIKELY DROP ANOTHER FOOT OR SO. SO WHILE NOT IDEAL CONDITIONS...NO ADVISORIES OR EXERCISE CAUTION STATEMENTS WILL BE NEEDED. NO TSTMS EXPECTED ON THE 0-20NM WATERS BUT A FEW SHOWERS MAY DOT AREAS AROUND WINYAH BAY. THE MAJORITY OF WAVE ENERGY WILL BE ARRIVING FROM E AND SE AND A MODERATE CHOP FROM THE S-SW IS EXPECTED MONDAY NIGHT AS WINDS NEAR 20 KT. AN EXERCISE CAUTION STATEMENT IS POSSIBLE MONDAY NIGHT INTO EARLY TUESDAY. LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 320 PM SATURDAY...PERSISTENT SOUTHWEST FLOW WILL CONTINUE THROUGH THE PERIOD WITH SUSTAINED WINDS OF 10 TO 15 KTS AND GUSTS TO NEAR 20 KTS DURING THE AFTERNOON HOURS EACH AFTERNOON. WITH MAINLY WIND DRIVEN WIND WAVES...TUESDAY AND WEDNESDAY SEAS WILL BE 2 TO 4 FT WITH 5 FTERS POSSIBLE IN THE EXTREME OUTER WATERS...ESPECIALLY IN AMZ-252 AND AMZ-250. INTO THURSDAY...SEAS WILL BEGIN TO SUBSIDE TO 2 TO 3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MJC NEAR TERM...TRA SHORT TERM...MJC LONG TERM...SGL AVIATION...DCH/BJR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1155 PM CDT SAT JUL 5 2014 .UPDATE... ISSUED AT 1155 PM CDT SAT JUL 5 2014 IN COORDINATION WITH SPC...EXPANDED THE SEVERE THUNDERSTORM WATCH TO THE EAST. STORMS ALREADY GETTING TO THE END OF THE BOX AND ENVIRONMENTAL CONDITIONS ARE SIMILAR ACROSS THE EASTERN FA. UPDATE ISSUED AT 1145 PM CDT SAT JUL 5 2014 SEVERE THUNDERSTORMS ARE INCREASING IN COVERAGE AS EXPECTED...AND A SEVERE THUNDERSTORM WATCH WAS ISSUED AS A RESULT. MAY NEED TO EXTEND THE SEVERE THUNDERSTORM WATCH EASTWARD IF TREND CONTINUE. UPDATE ISSUED AT 942 PM CDT SAT JUL 5 2014 THE FIRST SEVERE THREAT IS NOW EAST OF THE FA. ATTENTION NOW TURNS TO THE WEST WITH STORMS APPROACHING FROM CANADA AND FROM SOUTHERN NORTH DAKOTA. THE HRRR/RAP MAY BE TOO WIDESPREAD WITH COVERAGE IN THEIR FORECASTS...BUT BOTH INDICATE THE POTENTIAL FOR STORMS TO FILL IN BETWEEN THESE TWO SEVERE AREAS...AND INDICATE THAT THESE STORMS HAVE THE POTENTIAL FOR BOWING SEGMENTS (STRONG WIND GUSTS). INSTABILITY REMAINS STRONG...AND DEEP LAYER SHEAR IS INCREASING...ALONG WITH A 40-50 KNOT MID-LEVEL SPEED MAX...AND WITH A STRONG UPPER WAVE (DECENT SYNOPTIC FORCING). SO...THE HI- RES MODELS MAY BE ONTO SOMETHING. THIS LOOKS TO BE A BUSY NIGHT. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 320 PM CDT SAT JUL 5 2014 CHALLENGES INCLUDE THUNDERSTORM CHANCES AND SEVERE POTENTIAL THIS EVENING AND OVERNIGHT. HRRR IS ONCE AGAIN PERFORMING MORE FAVORABLY THAN RAP AS IT RELATES TO CURRENT CONVECTION...SO WILL FOLLOW ITS GUIDANCE FOR THE FIRST 12 TO 18 HOURS AND THEN TRANSITION TO A GLOBAL MODEL ENSEMBLE. SFC TROUGH REFUSES TO BUDGE WITH A DEFINED CLOSED CIRCULATION NEAR THE ND/MN/MB BORDER. WINDS HAVE SHIFTED TO A MORE WESTERLY DIRECTION FROM DEVILS LAKE INTO THE JAMES RIVER VALLEY RESULTING IN A DRIER OVERALL AIR MASS...ALTHOUGH SFC BASED CAPE IS STILL ABOVE 2000 J/KG. BEST CHANCE FOR THUNDERSTORMS LATE THIS AFTERNOON IS ALONG THE INTERNATIONAL BORDER AREA OF NORTHWEST MN IN UNCAPPED MORE MOIST/UNSTABLE ENVIRONMENT NEAREST THE SFC LOW. FORCING IS STILL RATHER WEAK...BUT ONE SEVERE STORM HAS DEVELOPED OVER WINNIPEG AND IS SLOWLY MOVING TO THE EAST. A COUPLE OTHER SMALL CELLS HAVE POPPED UP ALONG THE SFC WIND SHIFT JUST NORTH OF THE BORDER AND IN KITTSON COUNTY. ISOLATED SEVERE IS POSSIBLE GIVEN HIGH INSTABILITY. REST OF THE FORECAST AREA WILL REMAIN DRY THIS EVENING WITH TEMPS GRADUALLY FALLING INTO THE UPPER 60S. FOR LATE TONIGHT INTO EARLY SUNDAY MORNING...ATTENTION TURNS TO THE SHORT-WAVE CURRENTLY ACROSS SOUTHERN ALBERTA. INCREASING SHEAR WILL BEGIN TO INTERACT WITH MUCAPES UP TO 1500 J/KG...POSSIBLY RESULTING IN A NORTH TO SOUTH LINE OF CONVECTION MOVING ACROSS THE DAKOTAS AND INTO NORTHWEST MN. HRRR PLACES THIS LINE ALONG THE VALLEY FLOOR BY 06 UTC. LARGE HAIL AND DAMAGING WIND WILL BE THE PRIMARY THREATS. SCATTERED SHOWERS AND STORMS ARE POSSIBLE MAINLY ACROSS NORTHWEST AND WEST CENTRAL MN ON SUNDAY...BUT TEMPS/DEW POINTS WILL BE LOWER RESULTING IN LESS MUGGY CONDITIONS. WINDS WILL ALSO BE BREEZY AT TIMES FROM THE NORTHWEST WITH GUSTS TO 25 MPH. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 320 PM CDT SAT JUL 5 2014 FLOW ALOFT SHIFTS TO THE NORTHWEST MON/TUES WITH THE NEXT PRIMARY WAVE DROPPING ACROSS THE NORTHERN PLAINS MONDAY/MONDAY NIGHT. SEVERE WEATHER NOT EXPECTED...BUT SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE THROUGH THE DAY ON MONDAY WITH DRYING CONDITIONS FROM WEST TO EAST ON TUESDAY. FOR TUESDAY NIGHT THROUGH SATURDAY...SOME DISAGREEMENT IN HOW DEEP NEXT 500 MB TROUGH WILL BE OVER ONTARIO AND GREAT LAKES REGION. EITHER WAY FCST REGION WILL BE IN NORTHWEST FLOW ALOFT WITH EXITING SHORT WAVE TUESDAY NIGHT THEN GENERAL HIGH PRESSURE FOR WED-EARLY THU. NEXT SIGNIFICANT SHORT WAVE TO IMPACT US LATE THU-FRI. DIDNT STRAY FROM ALL BLEND TEMPS NOR POPS MUCH. OVERALL TEMP REGIME AFTER THIS WEEKEND FAVORS A RETURN TO JUST A FEW DEGREES BELOW AVERAGE FOR HIGH TEMPS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1145 PM CDT SAT JUL 5 2014 THUNDERSTORM CHANCES WILL BE THE MAIN CONCERN THROUGH THIS PERIOD...ESPECIALLY BEFORE SUNRISE. THERE SHOULD BE A BROKEN LINE OF STORMS THAT MOVE FROM WEST TO EAST THROUGH THE REGION. NOT SURE HOW WIDESPREAD THESE STORMS WILL BE...BUT DID TEMPO FOR THE MOST LIKELY PERIODS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...TG SHORT TERM...ROGERS LONG TERM...ROGERS/RIDDLE AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1145 PM CDT SAT JUL 5 2014 .UPDATE... ISSUED AT 1145 PM CDT SAT JUL 5 2014 SEVERE THUNDERSTORMS ARE INCREASING IN COVERAGE AS EXPECTED...AND A SEVERE THUNDERSTORM WATCH WAS ISSUED AS A RESULT. MAY NEED TO EXTEND THE SEVERE THUNDERSTORM WATCH EASTWARD IF TREND CONTINUE. UPDATE ISSUED AT 942 PM CDT SAT JUL 5 2014 THE FIRST SEVERE THREAT IS NOW EAST OF THE FA. ATTENTION NOW TURNS TO THE WEST WITH STORMS APPROACHING FROM CANADA AND FROM SOUTHERN NORTH DAKOTA. THE HRRR/RAP MAY BE TOO WIDESPREAD WITH COVERAGE IN THEIR FORECASTS...BUT BOTH INDICATE THE POTENTIAL FOR STORMS TO FILL IN BETWEEN THESE TWO SEVERE AREAS...AND INDICATE THAT THESE STORMS HAVE THE POTENTIAL FOR BOWING SEGMENTS (STRONG WIND GUSTS). INSTABILITY REMAINS STRONG...AND DEEP LAYER SHEAR IS INCREASING...ALONG WITH A 40-50 KNOT MID-LEVEL SPEED MAX...AND WITH A STRONG UPPER WAVE (DECENT SYNOPTIC FORCING). SO...THE HI- RES MODELS MAY BE ONTO SOMETHING. THIS LOOKS TO BE A BUSY NIGHT. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 320 PM CDT SAT JUL 5 2014 CHALLENGES INCLUDE THUNDERSTORM CHANCES AND SEVERE POTENTIAL THIS EVENING AND OVERNIGHT. HRRR IS ONCE AGAIN PERFORMING MORE FAVORABLY THAN RAP AS IT RELATES TO CURRENT CONVECTION...SO WILL FOLLOW ITS GUIDANCE FOR THE FIRST 12 TO 18 HOURS AND THEN TRANSITION TO A GLOBAL MODEL ENSEMBLE. SFC TROUGH REFUSES TO BUDGE WITH A DEFINED CLOSED CIRCULATION NEAR THE ND/MN/MB BORDER. WINDS HAVE SHIFTED TO A MORE WESTERLY DIRECTION FROM DEVILS LAKE INTO THE JAMES RIVER VALLEY RESULTING IN A DRIER OVERALL AIR MASS...ALTHOUGH SFC BASED CAPE IS STILL ABOVE 2000 J/KG. BEST CHANCE FOR THUNDERSTORMS LATE THIS AFTERNOON IS ALONG THE INTERNATIONAL BORDER AREA OF NORTHWEST MN IN UNCAPPED MORE MOIST/UNSTABLE ENVIRONMENT NEAREST THE SFC LOW. FORCING IS STILL RATHER WEAK...BUT ONE SEVERE STORM HAS DEVELOPED OVER WINNIPEG AND IS SLOWLY MOVING TO THE EAST. A COUPLE OTHER SMALL CELLS HAVE POPPED UP ALONG THE SFC WIND SHIFT JUST NORTH OF THE BORDER AND IN KITTSON COUNTY. ISOLATED SEVERE IS POSSIBLE GIVEN HIGH INSTABILITY. REST OF THE FORECAST AREA WILL REMAIN DRY THIS EVENING WITH TEMPS GRADUALLY FALLING INTO THE UPPER 60S. FOR LATE TONIGHT INTO EARLY SUNDAY MORNING...ATTENTION TURNS TO THE SHORT-WAVE CURRENTLY ACROSS SOUTHERN ALBERTA. INCREASING SHEAR WILL BEGIN TO INTERACT WITH MUCAPES UP TO 1500 J/KG...POSSIBLY RESULTING IN A NORTH TO SOUTH LINE OF CONVECTION MOVING ACROSS THE DAKOTAS AND INTO NORTHWEST MN. HRRR PLACES THIS LINE ALONG THE VALLEY FLOOR BY 06 UTC. LARGE HAIL AND DAMAGING WIND WILL BE THE PRIMARY THREATS. SCATTERED SHOWERS AND STORMS ARE POSSIBLE MAINLY ACROSS NORTHWEST AND WEST CENTRAL MN ON SUNDAY...BUT TEMPS/DEW POINTS WILL BE LOWER RESULTING IN LESS MUGGY CONDITIONS. WINDS WILL ALSO BE BREEZY AT TIMES FROM THE NORTHWEST WITH GUSTS TO 25 MPH. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 320 PM CDT SAT JUL 5 2014 FLOW ALOFT SHIFTS TO THE NORTHWEST MON/TUES WITH THE NEXT PRIMARY WAVE DROPPING ACROSS THE NORTHERN PLAINS MONDAY/MONDAY NIGHT. SEVERE WEATHER NOT EXPECTED...BUT SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE THROUGH THE DAY ON MONDAY WITH DRYING CONDITIONS FROM WEST TO EAST ON TUESDAY. FOR TUESDAY NIGHT THROUGH SATURDAY...SOME DISAGREEMENT IN HOW DEEP NEXT 500 MB TROUGH WILL BE OVER ONTARIO AND GREAT LAKES REGION. EITHER WAY FCST REGION WILL BE IN NORTHWEST FLOW ALOFT WITH EXITING SHORT WAVE TUESDAY NIGHT THEN GENERAL HIGH PRESSURE FOR WED-EARLY THU. NEXT SIGNIFICANT SHORT WAVE TO IMPACT US LATE THU-FRI. DIDNT STRAY FROM ALL BLEND TEMPS NOR POPS MUCH. OVERALL TEMP REGIME AFTER THIS WEEKEND FAVORS A RETURN TO JUST A FEW DEGREES BELOW AVERAGE FOR HIGH TEMPS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1145 PM CDT SAT JUL 5 2014 THUNDERSTORM CHANCES WILL BE THE MAIN CONCERN THROUGH THIS PERIOD...ESPECIALLY BEFORE SUNRISE. THERE SHOULD BE A BROKEN LINE OF STORMS THAT MOVE FROM WEST TO EAST THROUGH THE REGION. NOT SURE HOW WIDESPREAD THESE STORMS WILL BE...BUT DID TEMPO FOR THE MOST LIKELY PERIODS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...TG SHORT TERM...ROGERS LONG TERM...ROGERS/RIDDLE AVIATION...TG
AREA FORECAST DISCUSSION
NWS TULSA OK
1240 PM CDT SUN JUL 6 2014 .DISCUSSION... THE 18Z TAF DISCUSSION IS INCLUDED BELOW. && .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. VFR CONDITIONS WILL PREVAIL THIS PERIOD. A WEAK UPPER DISTURBANCE OVER MO WILL MOVE SOUTHEAST ACROSS NW AR...SO THERE IS SOME CHANCE FOR AN AFTERNOON STORM AT THE KXNA AND KFYV TAFS. HAVE INSERTED A VCTS MENTION TO COVER. SOUTH TO SOUTHWEST WINDS WILL BE GUSTY ACROSS NE OK...BUT WILL BACK OFF BY SUNSET THIS EVENING. LACY && .PREV DISCUSSION... /ISSUED 1037 AM CDT SUN JUL 6 2014/ DISCUSSION... LATEST RUNS OF THE HRRR SUGGEST AT LEAST SOME CHANCE OF SHOWERS AND ISOLATED STORMS WILL LINGER INTO THE AFTERNOON OVER NORTHWEST AR IN ASSOCIATION WITH A DISTURBANCE...POSSIBLY EVEN AN MCV...TRACKING SOUTHEAST ACROSS MO ATTM. THE FORECAST HAS BEEN ADJUSTED AND WILL CONTINUE TO MONITOR THE TRENDS. LACY PREV DISCUSSION... /ISSUED 837 AM CDT SUN JUL 6 2014/ DISCUSSION... A LOOSELY ORGANIZED MCS IS TRACKING ACROSS SOUTHWEST MO AND FAR NORTHEAST OK ATTM...IN ASSOCIATION WITH A WAVE (CONVECTIVELY ENHANCED MOST LIKELY) WRAPPING AROUND THE MID LVL RIDGE CENTERED OVER THE CENTRAL ROCKIES. THE SOUTHWEST FLANK IS WEAKENING AS IT TRACKS SOUTHEAST...WITH THE NORTHEAST FLANK REMAINS MORE INTENSE. HAVE THEREFORE INCREASED POPS OVER IN NORTHWEST AR WHERE THE STRONGER ACTIVITY IS HEADED. WILL INCREASE POPS MORE IF NEEDED. LACY PREV DISCUSSION... /ISSUED 631 AM CDT SUN JUL 6 2014/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS PARTS OF NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS THIS MORNING. BVO LOOKS TO HAVE THE GREATEST CHANCE OF SEEING PRECIP AND WILL CARRY -RA/VCTS...WHILE KEEPING THE REST OF THE TAF SITES DRY DUE TO LIMITED COVERAGE. OTHERWISE...SCATTERED TO BROKEN MID/HIGH CLOUD DECKS AND BREEZY SOUTHERLY WINDS WILL BE COMMON ACROSS THE REGION TODAY. SOUTHERLY WINDS DECREASE TONIGHT WITH SCATTERED HIGH CLOUDS PERSISTING. VFR CONDITIONS SHOULD CONTINUE THROUGH THE PERIOD. PREV DISCUSSION... /ISSUED 406 AM CDT SUN JUL 6 2014/ DISCUSSION... A FEW SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS THIS MORNING AS THE TAIL END OF A SHORTWAVE BRUSHES ACROSS THIS AREA. OTHERWISE THE HEAT WILL BE BUILDING TODAY AND MONDAY AS AN UPPER RIDGE BUILDS OVER THE AREA. SOME MODELS BRING TRIPLE DIGIT HEAT INTO THE WESTERN PART OF THE FORECAST AREA ESPECIALLY MONDAY BUT WILL NOT GO QUITE THAT HOT. A WEAK COLD FRONT WILL MOVE SOUTH INTO THE AREA TUESDAY AFTERNOON AND PROVIDE A FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS. THE FRONT WILL STALL WEDNESDAY AND THEN LIFT BACK NORTH AS A WARM FRONT THURSDAY WHICH WILL CONTINUE THE CHANCES FOR SHOWERS AND THUNDERSTORMS. THE UPPER RIDGE BUILDS BACK OVER THE AREA BY NEXT WEEKEND AND BEYOND BRINGING TEMPERATURES AS HOT OR HOTTER THAN WHAT WE WILL SEE THE NEXT COUPLE DAYS. STAYED CLOSE TO GUIDANCE TEMPERATURES THE NEXT COUPLE DAYS. && .PRELIMINARY POINT TEMPS/POPS... TUL 75 97 77 95 / 10 0 10 20 FSM 73 96 74 94 / 0 10 10 10 MLC 74 94 75 94 / 0 0 0 10 BVO 72 97 74 92 / 10 0 10 20 FYV 69 91 70 89 / 0 10 10 30 BYV 69 92 71 88 / 10 10 10 30 MKO 72 95 74 94 / 0 0 0 20 MIO 72 95 74 90 / 10 10 10 30 F10 73 95 74 94 / 0 0 0 10 HHW 72 93 73 92 / 0 10 0 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...30
AREA FORECAST DISCUSSION
NWS TULSA OK
1037 AM CDT SUN JUL 6 2014 .DISCUSSION... LATEST RUNS OF THE HRRR SUGGEST AT LEAST SOME CHANCE OF SHOWERS AND ISOLATED STORMS WILL LINGER INTO THE AFTERNOON OVER NORTHWEST AR IN ASSOCIATION WITH A DISTURBANCE...POSSIBLY EVEN AN MCV...TRACKING SOUTHEAST ACROSS MO ATTM. THE FORECAST HAS BEEN ADJUSTED AND WILL CONTINUE TO MONITOR THE TRENDS. LACY && .PREV DISCUSSION... /ISSUED 837 AM CDT SUN JUL 6 2014/ DISCUSSION... A LOOSELY ORGANIZED MCS IS TRACKING ACROSS SOUTHWEST MO AND FAR NORTHEAST OK ATTM...IN ASSOCIATION WITH A WAVE (CONVECTIVELY ENHANCED MOST LIKELY) WRAPPING AROUND THE MID LVL RIDGE CENTERED OVER THE CENTRAL ROCKIES. THE SOUTHWEST FLANK IS WEAKENING AS IT TRACKS SOUTHEAST...WITH THE NORTHEAST FLANK REMAINS MORE INTENSE. HAVE THEREFORE INCREASED POPS OVER IN NORTHWEST AR WHERE THE STRONGER ACTIVITY IS HEADED. WILL INCREASE POPS MORE IF NEEDED. LACY PREV DISCUSSION... /ISSUED 631 AM CDT SUN JUL 6 2014/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS PARTS OF NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS THIS MORNING. BVO LOOKS TO HAVE THE GREATEST CHANCE OF SEEING PRECIP AND WILL CARRY -RA/VCTS...WHILE KEEPING THE REST OF THE TAF SITES DRY DUE TO LIMITED COVERAGE. OTHERWISE...SCATTERED TO BROKEN MID/HIGH CLOUD DECKS AND BREEZY SOUTHERLY WINDS WILL BE COMMON ACROSS THE REGION TODAY. SOUTHERLY WINDS DECREASE TONIGHT WITH SCATTERED HIGH CLOUDS PERSISTING. VFR CONDITIONS SHOULD CONTINUE THROUGH THE PERIOD. PREV DISCUSSION... /ISSUED 406 AM CDT SUN JUL 6 2014/ DISCUSSION... A FEW SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS THIS MORNING AS THE TAIL END OF A SHORTWAVE BRUSHES ACROSS THIS AREA. OTHERWISE THE HEAT WILL BE BUILDING TODAY AND MONDAY AS AN UPPER RIDGE BUILDS OVER THE AREA. SOME MODELS BRING TRIPLE DIGIT HEAT INTO THE WESTERN PART OF THE FORECAST AREA ESPECIALLY MONDAY BUT WILL NOT GO QUITE THAT HOT. A WEAK COLD FRONT WILL MOVE SOUTH INTO THE AREA TUESDAY AFTERNOON AND PROVIDE A FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS. THE FRONT WILL STALL WEDNESDAY AND THEN LIFT BACK NORTH AS A WARM FRONT THURSDAY WHICH WILL CONTINUE THE CHANCES FOR SHOWERS AND THUNDERSTORMS. THE UPPER RIDGE BUILDS BACK OVER THE AREA BY NEXT WEEKEND AND BEYOND BRINGING TEMPERATURES AS HOT OR HOTTER THAN WHAT WE WILL SEE THE NEXT COUPLE DAYS. STAYED CLOSE TO GUIDANCE TEMPERATURES THE NEXT COUPLE DAYS. && .PRELIMINARY POINT TEMPS/POPS... TUL 95 75 97 77 / 20 10 0 10 FSM 93 73 96 74 / 10 0 10 10 MLC 93 74 94 75 / 0 0 0 0 BVO 94 72 97 74 / 20 10 0 10 FYV 88 69 91 70 / 30 0 10 10 BYV 88 69 92 71 / 30 10 10 10 MKO 93 72 95 74 / 20 0 0 0 MIO 90 72 95 74 / 20 10 10 10 F10 93 73 95 74 / 20 0 0 0 HHW 92 72 93 73 / 0 0 10 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...30
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
732 PM CDT MON JUL 7 2014 .UPDATE...FOR 00Z TAFS. && .AVIATION... CHANGES IN THE WORKS THIS PERIOD AS UPPER TROUGH AND WEAK FRONTAL BOUNDARY GET INTO THE PICTURE. DEVELOPMENT UPSTREAM EXPECTED TO DECREASE TONIGHT BUT SAG DOWN INTO THE AREA LATER. SHWRS/STMS THEN EXPECTED TO INCREASE EARLY TUE AND REMAIN FAIRLY WIDESPREAD WELL INTO TUE EVE. ALL SITES HAVE GOOD CHANCE OF BEING AFFECTED... WHICH WILL REDUCE CIGS/VSBYS. BEST CHANCE LARGELY AFTER 15Z TUE. WINDS ALSO EXPECTED TO GUST 20+KTS BY 15Z. && .PREV DISCUSSION... /ISSUED 627 PM CDT MON JUL 7 2014/ DISCUSSION... MCS CURRENTLY NOT TOO FAR OFF TO THE NORTH WITH THE CONVECTION AS FAR SOUTH AS HOPKINS AND MUHLENBERG COUNTIES. HRRR AND MODEL DATA SUGGESTS THAT THIS CONVECTION WILL WEAKEN QUICKLY AS IT APPROACHES. HOWEVER...THOUGH SOME WEAKENING IS EXPECTED...I FEEL AS IF POPS ACROSS THE NORTH MAY NEED TO BE INCREASED SLIGHTLY. SOME WIND DAMAGE HAS ALREADY OCCURRED WITH A FEW OF THESE STORMS EARLIER THIS AFTERNOON. LATEST MID LEVEL FLOW PATTERN SUGGESTS THAT THE STORMS WILL ENCOUNTER LESS FAVORABLE SHEAR AS THEY MOVE SOUTHWARD...SO BOTH THE INTENSITY AND COVERAGE SHOULD BE ON THE DECREASE. OTW...TOWARD 12Z...WE`LL SEE AN INCREASE IN ATMOSPHERIC MOISTURE WITH SOME ADDITIONAL DEVELOPMENT CONTINUING TO MOVE SOUTHWARD. FOR THE FCST...WILL LEAN TOWARD INCREASING POPS SOME OVERNIGHT. WHEN COMBINING THE CURRENT ACTIVITY WITH ADDITIONAL FAVORABLE CONVECTIVE CONDITIONS TOWARD 12Z...WILL NEED TO GO A LITTLE HIGHER THAN JUST A SLIGHT CHANCE. REMAINDER OF THE FCST APPEARS TO BE OK. WILL ADD A FEW EXTRA CLOUDS ACROSS THE NORTH. OVERNIGHT LOWS SHOULD BE WARMER TONIGHT AS DEWPOINT VALUES WERE HIGHER TODAY. UPDATE OUT SHORTLY. PREV DISCUSSION... /ISSUED 327 PM CDT MON JUL 7 2014/ DISCUSSION... HEAT AND MOISTURE HAVE RETURNED IN EARNEST TODAY WITH TEMPERATURES CURRENTLY RANGING FROM THE LOW 80S ON THE PLATEAU TO UPPER 80S/LOW 90S ELSEWHERE...ALONG WITH DEWPOINTS UP INTO THE 60S AND LOW 70S. WEAK SHORTWAVE TROUGH ALOFT NOTED ON WATER VAPOR IMAGERY HAS PROVIDED ENOUGH LIFT TO SPAWN SOME ISOLATED SHOWERS AND THUNDERSTORMS OVER SOUTHWEST ZONES THIS AFTERNOON. HAVE INCLUDED A PRE FIRST PERIOD FOR WESTERN ZONES ON ACCOUNT OF THIS DIURNALLY DRIVEN ACTIVITY. OTHERWISE...ATTENTION TURNS TO THE NORTH AS CONVECTION IS BLOSSOMING ALONG A WEAK COLD FRONT ADVANCING SOUTHWARD THROUGH THE MIDWEST. 12Z MODELS INDICATE THIS ACTIVITY...ALONG WITH AN EXPECTED MCS DEVELOPING NEAR KANSAS CITY...WILL MAKE A RUN AT OUR NORTHWEST ZONES LATE TONIGHT. CONSIDERABLE UNCERTAINTY ON HOW FAR THIS ACTIVITY WILL SURVIVE AND AT WHAT INTENSITY...BUT WARRANTS LOW CHANCE POPS OVER NORTHERN ZONES ESPECIALLY TOWARDS SUNRISE TUESDAY MORNING. CANNOT COMPLETELY RULE OUT A STRONG OR POSSIBLY EVEN SEVERE STORM IF CONVECTION CAN SURVIVE THIS FAR SOUTH AS SPC HAS INDICATED IN THEIR DAY 1 OUTLOOK...BUT FAR BETTER CHANCE FOR STRONG TO SEVERE STORMS WILL BE WELL OFF TO OUR NORTH. ON TUESDAY...REMNANTS OF MCS SHOULD WEAKEN/DISSIPATE WITH ALL GUIDANCE INDICATING RENEWED CONVECTIVE DEVELOPMENT ALONG FRONTAL BOUNDARY SITUATED NEAR THE OHIO RIVER TUESDAY AFTERNOON. 12Z GUIDANCE HAS SPED UP ARRIVAL OF THIS ACTIVITY WITH STORMS LIKELY REACHING THE KY BORDER BY LATE AFTERNOON...THEN MOVING ACROSS THE MID STATE THROUGH THE EVENING BEFORE WEAKENING LATE TUESDAY NIGHT. HAVE KEPT POPS ABOVE GUIDANCE IN THE LIKELY TO CATEGORICAL RANGE DUE TO CONFIDENCE IN THIS SCENARIO. 12Z GFS/NAM FORECAST SOUNDINGS ARE MORE ROBUST WITH INSTABILITY VS THIS TIME YESTERDAY SHOWING LI VALUES AS LOW AS -7 TO -8 ALONG WITH SBCAPE AS HIGH AS 3000 J/KG. THESE PARAMETERS ALONG WITH DEEP LAYER SHEAR AROUND 40 KNOTS AND PWAT VALUES UP TO 2 INCHES SUGGESTS STRONG TO SEVERE STORMS WILL BE POSSIBLE WITH DAMAGING WINDS AND LOCALLY HEAVY RAINFALL THE MAIN THREATS...WITH HIGHEST RISK ALONG AND NORTH OF I-40 LATE TUESDAY AFTERNOON INTO TUESDAY EVENING. HOWEVER...SPC HAS HIGHLIGHTED THE ENTIRE MID STATE IN A SLIGHT RISK FOR SEVERE STORMS ON THEIR DAY 2 OUTLOOK. WEAK COLD FRONT WILL SHIFT SLOWLY SOUTHWARD THROUGH THE MID STATE DURING THE DAY ON WEDNESDAY...WITH ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT POSSIBLE ALONG THE BOUNDARY OVER SOUTHERN ZONES. FRONT PROGGED TO SHIFT SOUTH OF THE AL BORDER BY WEDNESDAY NIGHT WITH SLIGHTLY COOLER AND DRY WEATHER ANTICIPATED THURSDAY AND FRIDAY. STAYED VERY CLOSE TO PREVIOUS FORECAST TEMPS DURING THIS TIMEFRAME...WHICH ARE ALSO VERY CLOSE TO 12Z MEX GUIDANCE. BY NEXT WEEKEND...MODELS BUILD A STRONG RIDGE OVER THE SOUTHERN PLAINS EASTWARD INTO THE TENNESSEE VALLEY...SUGGESTING A SHARP WARMUP FOR SATURDAY AND SUNDAY WITH HIGHS BACK INTO THE MID 90S FOR MUCH OF MIDDLE TENNESSEE. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
627 PM CDT MON JUL 7 2014 .DISCUSSION... MCS CURRENTLY NOT TOO FAR OFF TO THE NORTH WITH THE CONVECTION AS FAR SOUTH AS HOPKINS AND MUHLENBERG COUNTIES. HRRR AND MODEL DATA SUGGESTS THAT THIS CONVECTION WILL WEAKEN QUICKLY AS IT APPROACHES. HOWEVER...THOUGH SOME WEAKENING IS EXPECTED...I FEEL AS IF POPS ACROSS THE NORTH MAY NEED TO BE INCREASED SLIGHTLY. SOME WIND DAMAGE HAS ALREADY OCCURRED WITH A FEW OF THESE STORMS EARLIER THIS AFTERNOON. LATEST MID LEVEL FLOW PATTERN SUGGESTS THAT THE STORMS WILL ENCOUNTER LESS FAVORABLE SHEAR AS THEY MOVE SOUTHWARD...SO BOTH THE INTENSITY AND COVERAGE SHOULD BE ON THE DECREASE. OTW...TOWARD 12Z...WE`LL SEE AN INCREASE IN ATMOSPHERIC MOISTURE WITH SOME ADDITIONAL DEVELOPMENT CONTINUING TO MOVE SOUTHWARD. FOR THE FCST...WILL LEAN TOWARD INCREASING POPS SOME OVERNIGHT. WHEN COMBINING THE CURRENT ACTIVITY WITH ADDITIONAL FAVORABLE CONVECTIVE CONDITIONS TOWARD 12Z...WILL NEED TO GO A LITTLE HIGHER THAN JUST A SLIGHT CHANCE. REMAINDER OF THE FCST APPEARS TO BE OK. WILL ADD A FEW EXTRA CLOUDS ACROSS THE NORTH. OVERNIGHT LOWS SHOULD BE WARMER TONIGHT AS DEWPOINT VALUES WERE HIGHER TODAY. UPDATE OUT SHORTLY. && .PREV DISCUSSION... /ISSUED 327 PM CDT MON JUL 7 2014/ DISCUSSION... HEAT AND MOISTURE HAVE RETURNED IN EARNEST TODAY WITH TEMPERATURES CURRENTLY RANGING FROM THE LOW 80S ON THE PLATEAU TO UPPER 80S/LOW 90S ELSEWHERE...ALONG WITH DEWPOINTS UP INTO THE 60S AND LOW 70S. WEAK SHORTWAVE TROUGH ALOFT NOTED ON WATER VAPOR IMAGERY HAS PROVIDED ENOUGH LIFT TO SPAWN SOME ISOLATED SHOWERS AND THUNDERSTORMS OVER SOUTHWEST ZONES THIS AFTERNOON. HAVE INCLUDED A PRE FIRST PERIOD FOR WESTERN ZONES ON ACCOUNT OF THIS DIURNALLY DRIVEN ACTIVITY. OTHERWISE...ATTENTION TURNS TO THE NORTH AS CONVECTION IS BLOSSOMING ALONG A WEAK COLD FRONT ADVANCING SOUTHWARD THROUGH THE MIDWEST. 12Z MODELS INDICATE THIS ACTIVITY...ALONG WITH AN EXPECTED MCS DEVELOPING NEAR KANSAS CITY...WILL MAKE A RUN AT OUR NORTHWEST ZONES LATE TONIGHT. CONSIDERABLE UNCERTAINTY ON HOW FAR THIS ACTIVITY WILL SURVIVE AND AT WHAT INTENSITY...BUT WARRANTS LOW CHANCE POPS OVER NORTHERN ZONES ESPECIALLY TOWARDS SUNRISE TUESDAY MORNING. CANNOT COMPLETELY RULE OUT A STRONG OR POSSIBLY EVEN SEVERE STORM IF CONVECTION CAN SURVIVE THIS FAR SOUTH AS SPC HAS INDICATED IN THEIR DAY 1 OUTLOOK...BUT FAR BETTER CHANCE FOR STRONG TO SEVERE STORMS WILL BE WELL OFF TO OUR NORTH. ON TUESDAY...REMNANTS OF MCS SHOULD WEAKEN/DISSIPATE WITH ALL GUIDANCE INDICATING RENEWED CONVECTIVE DEVELOPMENT ALONG FRONTAL BOUNDARY SITUATED NEAR THE OHIO RIVER TUESDAY AFTERNOON. 12Z GUIDANCE HAS SPED UP ARRIVAL OF THIS ACTIVITY WITH STORMS LIKELY REACHING THE KY BORDER BY LATE AFTERNOON...THEN MOVING ACROSS THE MID STATE THROUGH THE EVENING BEFORE WEAKENING LATE TUESDAY NIGHT. HAVE KEPT POPS ABOVE GUIDANCE IN THE LIKELY TO CATEGORICAL RANGE DUE TO CONFIDENCE IN THIS SCENARIO. 12Z GFS/NAM FORECAST SOUNDINGS ARE MORE ROBUST WITH INSTABILITY VS THIS TIME YESTERDAY SHOWING LI VALUES AS LOW AS -7 TO -8 ALONG WITH SBCAPE AS HIGH AS 3000 J/KG. THESE PARAMETERS ALONG WITH DEEP LAYER SHEAR AROUND 40 KNOTS AND PWAT VALUES UP TO 2 INCHES SUGGESTS STRONG TO SEVERE STORMS WILL BE POSSIBLE WITH DAMAGING WINDS AND LOCALLY HEAVY RAINFALL THE MAIN THREATS...WITH HIGHEST RISK ALONG AND NORTH OF I-40 LATE TUESDAY AFTERNOON INTO TUESDAY EVENING. HOWEVER...SPC HAS HIGHLIGHTED THE ENTIRE MID STATE IN A SLIGHT RISK FOR SEVERE STORMS ON THEIR DAY 2 OUTLOOK. WEAK COLD FRONT WILL SHIFT SLOWLY SOUTHWARD THROUGH THE MID STATE DURING THE DAY ON WEDNESDAY...WITH ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT POSSIBLE ALONG THE BOUNDARY OVER SOUTHERN ZONES. FRONT PROGGED TO SHIFT SOUTH OF THE AL BORDER BY WEDNESDAY NIGHT WITH SLIGHTLY COOLER AND DRY WEATHER ANTICIPATED THURSDAY AND FRIDAY. STAYED VERY CLOSE TO PREVIOUS FORECAST TEMPS DURING THIS TIMEFRAME...WHICH ARE ALSO VERY CLOSE TO 12Z MEX GUIDANCE. BY NEXT WEEKEND...MODELS BUILD A STRONG RIDGE OVER THE SOUTHERN PLAINS EASTWARD INTO THE TENNESSEE VALLEY...SUGGESTING A SHARP WARMUP FOR SATURDAY AND SUNDAY WITH HIGHS BACK INTO THE MID 90S FOR MUCH OF MIDDLE TENNESSEE. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION...CORRECTED
NWS AMARILLO TX
553 PM CDT SUN JUL 6 2014 .AVIATION... 00Z TAF CYCLE ISOLATED CONVECTION OVER THE NORTHWEST TEXAS AND THE OKLAHOMA PANHANDLES SHOULD DISSIPATE AFTER SUNSET AROUND 02Z TO 03Z MONDAY. THE CONVECTION IS EXPECTED TO BE CLOSE TO THE GUYMON TAF SITE BUT ONLY VCTS NEEDED AT THIS POINT. THE CONVECTION MAY AFFECT THE DALHART TAF SITE UNTIL AROUND 02Z TO 03Z MONDAY AND THEREFORE WILL INCLUDE A TEMPO GROUP. OTHERWISE...VFR CONDITIONS LIKELY THROUGH 00Z TUESDAY. SOUTH AND SOUTHWEST WINDS 5 TO 15 KNOTS AT ALL THREE TAF SITES THROUGH THE TAF FORECAST PERIOD. SCHNEIDER && .PREV DISCUSSION... /ISSUED 405 PM CDT SUN JUL 6 2014/ UPDATE... ISOLATED CONVECTION DEVELOPING THIS AFTERNOON ACROSS THE NORTH CENTRAL AND NORTHWEST TEXAS PANHANDLE. UPDATED PREVIOUS FORECAST TO EXPAND THE LOW END SLIGHT CHANCE POPS THIS EVENING FURTHER NORTH AND WEST AND CALL FOR AREAL QUALIFIERS RATHER THAN CATEGORICAL PRECIP. ALSO INCREASED SKY COVER MORE THIS EVENING. SCHNEIDER PREV DISCUSSION... /ISSUED 238 PM CDT SUN JUL 6 2014/ DISCUSSION... SURFACE LOW OVER EASTERN COLORADO WITH SURFACE TROUGH EXTENDING BACK ACROSS EASTERN NEW MEXICO AND THE NORTHWEST PORTIONS OF THE FORECAST AREA. UPPER HIGH SITUATED OVER THE CENTRAL ROCKIES AND GREAT BASION REGION MAINTAINING A NORTHERLY TO NORTHEASTERLY UPPER FLOW ACROSS THE PANHANDLES. EMBEDDED SHORTWAVE TROUGH ON THE EASTERN PERIPHERY OF THE UPPER HIGH FORECAST TO DROP SOUTH ACROSS THE TEXAS PANHANDLE AROUND 00Z TO 03Z MONDAY. EXPECT GENERALLY ISOLATED CONVECTION TO DEVELOP ACROSS THE NORTHERN TEXAS PANHANDLE BY MID TO LATE AFTERNOON AND THEN TRACKING SOUTH ACROSS THE REMAINDER OF THE TEXAS PANHANDLE BY 03Z MONDAY. FEEL THAT ANY CONVECTION WILL LIKELY DISSIPATE WITH LOSS OF DAYTIME HEATING AND DECIDED TO INSERT LOW END SLIGHT CHANCE POPS ACROSS PORTIONS OF THE TEXAS PANHANDLE THROUGH 03Z MONDAY. THE LATEST TTU-WRF AND...TO SOME EXTENT...THE HRRR ALONG WITH THE NAM...RUC AND ECMWF SUPPORT THIS SCENARIO. ELONGATED UPPER RIDGE BUILDS IN OVER THE PANHANDLES EARLY THIS WEEK AS A COLD FRONT PUSHES SLOWLY SOUTH INTO THE OKLAHOMA AND NORTHERN TEXAS PANHANDLES LATE MONDAY NIGHT OR EARLY TUESDAY MORNING...06Z TO 12Z TUESDAY. FRONTAL BOUNDARY TO BECOME STATIONARY ACROSS THE TEXAS PANHANDLE TUESDAY WITH LITTLE OR NO UPPER SUPPORT AS THE UPPER RIDGE CONTINUES TO BUILD FROM THE GREAT BASION REGION BACK DOWN INTO THE PANHANDLES AND THE SOUTHERN PLAINS STATES. WEAKNESS ON THE EASTERN PERIPHERY OF THE UPPER RIDGE WILL LEAD TO SHORTWAVE TROUGHS AFFECTING THE FORECAST AREA IN COMBINATION WITH THE STALLED OUT FRONTAL BOUNDARY. WEAK STEERING FLOW WILL RESULT IN CONVECTION...DEVELOPING OVER THE FORECAST AREA...TO MOVE LITTLE AND CAUSING LOCALLY HEAVY RAINFALL AND POSSIBLE FLOODING/FLASH FLOODING CONCERNS BY TUESDAY EVENING THROUGH WEDNESDAY OR WEDNESDAY NIGHT. STALLED FRONTAL BOUNDARY FORECAST TO LIFT NORTHEAST AS A WARM FRONT BY THURSDAY AND FRIDAY AS UPPER RIDGE AND SUBSIDENCE PREVAIL ACROSS THE PANHANDLES. DRY CONDITIONS BY LATE THIS WEEK INTO NEXT WEEKEND. SCHNEIDER FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED ACROSS THE PANHANDLES THROUGH AT LEAST THE MIDDLE AND END OF NEXT WEEK. SCHNEIDER && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 11/01
AREA FORECAST DISCUSSION
NWS AMARILLO TX
541 PM CDT SUN JUL 6 2014 .AVIATION... 00Z TAF CYCLE ISOLATED CONVECTION OVER THE NORTHWEST TEXAS AND THE OKLAHOMA PANHANDLES SHOULD DISSIPATE AFTER SUNSET AROUND 02Z TO 03Z MONDAY. THE CONVECTION IS EXPECTED TO BE CLOSE TO THE GUYMON TAF SITE BUT ONLY VCTS NEEDED AT THIS POINT. THE CONVECTION MAY AFFECT THE DALHART TAF SITE UNTIL AROUND 02Z TO 03Z MONDAY AND THEREFORE WILL INCLUDE A PROB30 GROUP. OTHERWISE...VFR CONDITIONS LIKELY THROUGH 00Z TUESDAY. SOUTH AND SOUTHWEST WINDS 5 TO 15 KNOTS AT ALL THREE TAF SITES THROUGH THE TAF FORECAST PERIOD. SCHNEIDER && .PREV DISCUSSION... /ISSUED 405 PM CDT SUN JUL 6 2014/ UPDATE... ISOLATED CONVECTION DEVELOPING THIS AFTERNOON ACROSS THE NORTH CENTRAL AND NORTHWEST TEXAS PANHANDLE. UPDATED PREVIOUS FORECAST TO EXPAND THE LOW END SLIGHT CHANCE POPS THIS EVENING FURTHER NORTH AND WEST AND CALL FOR AREAL QUALIFIERS RATHER THAN CATEGORICAL PRECIP. ALSO INCREASED SKY COVER MORE THIS EVENING. SCHNEIDER PREV DISCUSSION... /ISSUED 238 PM CDT SUN JUL 6 2014/ DISCUSSION... SURFACE LOW OVER EASTERN COLORADO WITH SURFACE TROUGH EXTENDING BACK ACROSS EASTERN NEW MEXICO AND THE NORTHWEST PORTIONS OF THE FORECAST AREA. UPPER HIGH SITUATED OVER THE CENTRAL ROCKIES AND GREAT BASION REGION MAINTAINING A NORTHERLY TO NORTHEASTERLY UPPER FLOW ACROSS THE PANHANDLES. EMBEDDED SHORTWAVE TROUGH ON THE EASTERN PERIPHERY OF THE UPPER HIGH FORECAST TO DROP SOUTH ACROSS THE TEXAS PANHANDLE AROUND 00Z TO 03Z MONDAY. EXPECT GENERALLY ISOLATED CONVECTION TO DEVELOP ACROSS THE NORTHERN TEXAS PANHANDLE BY MID TO LATE AFTERNOON AND THEN TRACKING SOUTH ACROSS THE REMAINDER OF THE TEXAS PANHANDLE BY 03Z MONDAY. FEEL THAT ANY CONVECTION WILL LIKELY DISSIPATE WITH LOSS OF DAYTIME HEATING AND DECIDED TO INSERT LOW END SLIGHT CHANCE POPS ACROSS PORTIONS OF THE TEXAS PANHANDLE THROUGH 03Z MONDAY. THE LATEST TTU-WRF AND...TO SOME EXTENT...THE HRRR ALONG WITH THE NAM...RUC AND ECMWF SUPPORT THIS SCENARIO. ELONGATED UPPER RIDGE BUILDS IN OVER THE PANHANDLES EARLY THIS WEEK AS A COLD FRONT PUSHES SLOWLY SOUTH INTO THE OKLAHOMA AND NORTHERN TEXAS PANHANDLES LATE MONDAY NIGHT OR EARLY TUESDAY MORNING...06Z TO 12Z TUESDAY. FRONTAL BOUNDARY TO BECOME STATIONARY ACROSS THE TEXAS PANHANDLE TUESDAY WITH LITTLE OR NO UPPER SUPPORT AS THE UPPER RIDGE CONTINUES TO BUILD FROM THE GREAT BASION REGION BACK DOWN INTO THE PANHANDLES AND THE SOUTHERN PLAINS STATES. WEAKNESS ON THE EASTERN PERIPHERY OF THE UPPER RIDGE WILL LEAD TO SHORTWAVE TROUGHS AFFECTING THE FORECAST AREA IN COMBINATION WITH THE STALLED OUT FRONTAL BOUNDARY. WEAK STEERING FLOW WILL RESULT IN CONVECTION...DEVELOPING OVER THE FORECAST AREA...TO MOVE LITTLE AND CAUSING LOCALLY HEAVY RAINFALL AND POSSIBLE FLOODING/FLASH FLOODING CONCERNS BY TUESDAY EVENING THROUGH WEDNESDAY OR WEDNESDAY NIGHT. STALLED FRONTAL BOUNDARY FORECAST TO LIFT NORTHEAST AS A WARM FRONT BY THURSDAY AND FRIDAY AS UPPER RIDGE AND SUBSIDENCE PREVAIL ACROSS THE PANHANDLES. DRY CONDITIONS BY LATE THIS WEEK INTO NEXT WEEKEND. SCHNEIDER FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED ACROSS THE PANHANDLES THROUGH AT LEAST THE MIDDLE AND END OF NEXT WEEK. SCHNEIDER && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 11/01
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
405 PM CDT SUN JUL 6 2014 .UPDATE... ISOLATED CONVECTION DEVELOPING THIS AFTERNOON ACROSS THE NORTH CENTRAL AND NORTHWEST TEXAS PANHANDLE. UPDATED PREVIOUS FORECAST TO EXPAND THE LOW END SLIGHT CHANCE POPS THIS EVENING FURTHER NORTH AND WEST AND CALL FOR AREAL QUALIFIERS RATHER THAN CATEGORICAL PRECIP. ALSO INCREASED SKY COVER MORE THIS EVENING. SCHNEIDER && .PREV DISCUSSION... /ISSUED 238 PM CDT SUN JUL 6 2014/ DISCUSSION... SURFACE LOW OVER EASTERN COLORADO WITH SURFACE TROUGH EXTENDING BACK ACROSS EASTERN NEW MEXICO AND THE NORTHWEST PORTIONS OF THE FORECAST AREA. UPPER HIGH SITUATED OVER THE CENTRAL ROCKIES AND GREAT BASION REGION MAINTAINING A NORTHERLY TO NORTHEASTERLY UPPER FLOW ACROSS THE PANHANDLES. EMBEDDED SHORTWAVE TROUGH ON THE EASTERN PERIPHERY OF THE UPPER HIGH FORECAST TO DROP SOUTH ACROSS THE TEXAS PANHANDLE AROUND 00Z TO 03Z MONDAY. EXPECT GENERALLY ISOLATED CONVECTION TO DEVELOP ACROSS THE NORTHERN TEXAS PANHANDLE BY MID TO LATE AFTERNOON AND THEN TRACKING SOUTH ACROSS THE REMAINDER OF THE TEXAS PANHANDLE BY 03Z MONDAY. FEEL THAT ANY CONVECTION WILL LIKELY DISSIPATE WITH LOSS OF DAYTIME HEATING AND DECIDED TO INSERT LOW END SLIGHT CHANCE POPS ACROSS PORTIONS OF THE TEXAS PANHANDLE THROUGH 03Z MONDAY. THE LATEST TTU-WRF AND...TO SOME EXTENT...THE HRRR ALONG WITH THE NAM...RUC AND ECMWF SUPPORT THIS SCENARIO. ELONGATED UPPER RIDGE BUILDS IN OVER THE PANHANDLES EARLY THIS WEEK AS A COLD FRONT PUSHES SLOWLY SOUTH INTO THE OKLAHOMA AND NORTHERN TEXAS PANHANDLES LATE MONDAY NIGHT OR EARLY TUESDAY MORNING...06Z TO 12Z TUESDAY. FRONTAL BOUNDARY TO BECOME STATIONARY ACROSS THE TEXAS PANHANDLE TUESDAY WITH LITTLE OR NO UPPER SUPPORT AS THE UPPER RIDGE CONTINUES TO BUILD FROM THE GREAT BASION REGION BACK DOWN INTO THE PANHANDLES AND THE SOUTHERN PLAINS STATES. WEAKNESS ON THE EASTERN PERIPHERY OF THE UPPER RIDGE WILL LEAD TO SHORTWAVE TROUGHS AFFECTING THE FORECAST AREA IN COMBINATION WITH THE STALLED OUT FRONTAL BOUNDARY. WEAK STEERING FLOW WILL RESULT IN CONVECTION...DEVELOPING OVER THE FORECAST AREA...TO MOVE LITTLE AND CAUSING LOCALLY HEAVY RAINFALL AND POSSIBLE FLOODING/FLASH FLOODING CONCERNS BY TUESDAY EVENING THROUGH WEDNESDAY OR WEDNESDAY NIGHT. STALLED FRONTAL BOUNDARY FORECAST TO LIFT NORTHEAST AS A WARM FRONT BY THURSDAY AND FRIDAY AS UPPER RIDGE AND SUBSIDENCE PREVAIL ACROSS THE PANHANDLES. DRY CONDITIONS BY LATE THIS WEEK INTO NEXT WEEKEND. SCHNEIDER FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED ACROSS THE PANHANDLES THROUGH AT LEAST THE MIDDLE AND END OF NEXT WEEK. SCHNEIDER && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 19/11
AREA FORECAST DISCUSSION
NWS AMARILLO TX
238 PM CDT SUN JUL 6 2014 .DISCUSSION... SURFACE LOW OVER EASTERN COLORADO WITH SURFACE TROUGH EXTENDING BACK ACROSS EASTERN NEW MEXICO AND THE NORTHWEST PORTIONS OF THE FORECAST AREA. UPPER HIGH SITUATED OVER THE CENTRAL ROCKIES AND GREAT BASION REGION MAINTAINING A NORTHERLY TO NORTHEASTERLY UPPER FLOW ACROSS THE PANHANDLES. EMBEDDED SHORTWAVE TROUGH ON THE EASTERN PERIPHERY OF THE UPPER HIGH FORECAST TO DROP SOUTH ACROSS THE TEXAS PANHANDLE AROUND 00Z TO 03Z MONDAY. EXPECT GENERALLY ISOLATED CONVECTION TO DEVELOP ACROSS THE NORTHERN TEXAS PANHANDLE BY MID TO LATE AFTERNOON AND THEN TRACKING SOUTH ACROSS THE REMAINDER OF THE TEXAS PANHANDLE BY 03Z MONDAY. FEEL THAT ANY CONVECTION WILL LIKELY DISSIPATE WITH LOSS OF DAYTIME HEATING AND DECIDED TO INSERT LOW END SLIGHT CHANCE POPS ACROSS PORTIONS OF THE TEXAS PANHANDLE THROUGH 03Z MONDAY. THE LATEST TTU-WRF AND...TO SOME EXTENT...THE HRRR ALONG WITH THE NAM...RUC AND ECMWF SUPPORT THIS SCENARIO. ELONGATED UPPER RIDGE BUILDS IN OVER THE PANHANDLES EARLY THIS WEEK AS A COLD FRONT PUSHES SLOWLY SOUTH INTO THE OKLAHOMA AND NORTHERN TEXAS PANHANDLES LATE MONDAY NIGHT OR EARLY TUESDAY MORNING...06Z TO 12Z TUESDAY. FRONTAL BOUNDARY TO BECOME STATIONARY ACROSS THE TEXAS PANHANDLE TUESDAY WITH LITTLE OR NO UPPER SUPPORT AS THE UPPER RIDGE CONTINUES TO BUILD FROM THE GREAT BASION REGION BACK DOWN INTO THE PANHANDLES AND THE SOUTHERN PLAINS STATES. WEAKNESS ON THE EASTERN PERIPHERY OF THE UPPER RIDGE WILL LEAD TO SHORTWAVE TROUGHS AFFECTING THE FORECAST AREA IN COMBINATION WITH THE STALLED OUT FRONTAL BOUNDARY. WEAK STEERING FLOW WILL RESULT IN CONVECTION...DEVELOPING OVER THE FORECAST AREA...TO MOVE LITTLE AND CAUSING LOCALLY HEAVY RAINFALL AND POSSIBLE FLOODING/FLASH FLOODING CONCERNS BY TUESDAY EVENING THROUGH WEDNESDAY OR WEDNESDAY NIGHT. STALLED FRONTAL BOUNDARY FORECAST TO LIFT NORTHEAST AS A WARM FRONT BY THURSDAY AND FRIDAY AS UPPER RIDGE AND SUBSIDENCE PREVAIL ACROSS THE PANHANDLES. DRY CONDITIONS BY LATE THIS WEEK INTO NEXT WEEKEND. SCHNEIDER && .FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED ACROSS THE PANHANDLES THROUGH AT LEAST THE MIDDLE AND END OF NEXT WEEK. SCHNEIDER && .PRELIMINARY POINT TEMPS/POPS... AMARILLO TX 67 95 67 91 69 / 20 5 5 20 40 BEAVER OK 72 103 72 92 68 / 5 5 5 20 30 BOISE CITY OK 66 100 70 89 65 / 10 5 5 30 30 BORGER TX 68 101 69 94 71 / 20 5 5 20 40 BOYS RANCH TX 67 100 68 95 71 / 20 5 5 20 40 CANYON TX 66 95 65 92 68 / 20 5 5 10 40 CLARENDON TX 69 96 69 94 70 / 20 5 5 10 30 DALHART TX 67 99 67 91 66 / 20 5 5 30 40 GUYMON OK 70 102 70 91 68 / 5 5 5 30 40 HEREFORD TX 64 94 63 92 67 / 20 5 5 10 30 LIPSCOMB TX 71 100 72 92 67 / 20 5 5 20 30 PAMPA TX 69 97 70 92 69 / 20 5 5 20 40 SHAMROCK TX 70 97 70 94 68 / 20 5 5 10 30 WELLINGTON TX 72 99 71 97 70 / 20 5 5 5 30 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 13/11
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1228 PM CDT SUN JUL 6 2014 .AVIATION... HAVE AFTERNOON VCSH/VCTS IN THE 18Z TAFS AS DAYTIME HEATING HELPS TO INITIATE MORE SHRA/TSRA. EXPECT WEAKENING AND DISSIPATION THIS EVENING...THEN POSSIBLE MVFR FOG DEVELOPMENT OVERNIGHT WHERE GROUNDS ARE WET. FOR TOMORROW...CARRIED VCSH NEAR THE COAST AROUND SUNRISE AND THEN A LITTLE FURTHER INLAND DURING THE MORNING HOURS. EXPECT TO SEE MORE SHRA/TSRA DEVELOPMENT ON MONDAY. 42 && .PREV DISCUSSION... /ISSUED 919 AM CDT SUN JUL 6 2014/ UPDATE... SEE DISCUSSION FOR MORNING UPDATE. DISCUSSION... NOT MUCH CHANGE IN PATTERN FROM YESTERDAY. SCATTERED SHOWERS AND THUNDERSTORMS HAVE FORMED OVER THE WATERS THIS MORNING AND HAVE STARTED TO MOVE INLAND. GFS AND NAM FORECAST SOUNDINGS SHOWING PWATS AROUND 1.7" THIS AFTERNOON WITH K INDICES IN THE LOWER TO MID 30S. EXPECTING COVERAGE TO INCREASE OVER INLAND AREAS THIS AFTERNOON THANKS TO DAY TIME HEATING. HIGH RES HRRR AND TEXAS TECH WRF AGAIN SHOWING GREATEST CHANCES TOWARDS THE SOUTHWEST. GRANTED THEY HAVE NOT INITIALIZED GREAT. COVERAGE MIGHT AGAIN BE MORE THAN 40 PERCENT IN SOME AREAS BUT GIVEN MESOSCALE NATURE OF STORMS HARD TO PIN POINT EXACT LOCATION. CURRENT FORECAST HAS TAKEN THE ABOVE INTO ACCOUNT. NO UPDATE REQUIRED AT THIS TIME. 23 PREV DISCUSSION... /ISSUED 355 AM CDT SUN JUL 6 2014/ DISCUSSION... CURRENT FCST LOOKS GOOD AND MADE VERY FEW CHANGES TO IT. EXPECT GENERAL PATTERN OF ISO/SCT PRECIP TO DEVELOP OFFSHORE LATE NIGHT & EARLY MORNING THEN TRANSITION INLAND DURING THE DAY COMPLIMENTS OF DAYTIME HEATING AND THE SEABREEZE. OVERALL COVERAGE DEPENDS ON SLIGHT VARIATIONS OF MOISTURE AVAILABILITY & LOCATION EACH DAY. SFC HIGH PRES SHOULD REMAIN CENTERED OFF TO THE EAST ALLOWING WEAK ONSHORE FLOW TO PERSIST. FURTHER ALOFT...LOOKS LIKE WE`LL REMAIN IN A SLIGHT WEAKNESS BETWEEN RIDGES. SOME OF THE MEDIUM RANGE SOLNS DO SUGGEST UPPER RIDGE BUILDING FURTHER OVERHEAD TOWARD NEXT WEEKEND WHICH WOULD BRING RAIN CHANCES DOWN AND TEMPS UP. JUST SOMETHING TO KEEP AN EYE ON - BUT PERSISTENCE FCST WILL DO FOR NOW. 47 MARINE... AS HIGH PRESSURE EDGES OFF TO THE EAST THE ONSHORE FLOW SHOULD BE IN- CREASING SLIGHTLY THE NEXT DAY OR SO. THESE LIGHT/MODERATE WINDS ARE FCST TO PERSIST FOR MUCH OF THE WEEK AS THE WX PATTERN REMAINS GENER- ALLY QUIET. NO ADVISORIES/CAUTION FLAGS ARE ANTICIPATED EXPECTED THE NEXT SEVERAL DAYS. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 93 73 93 74 93 / 20 20 30 10 20 HOUSTON (IAH) 92 74 92 75 92 / 30 20 30 10 30 GALVESTON (GLS) 89 79 89 80 90 / 30 20 20 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...23 AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
919 AM CDT SUN JUL 6 2014 .UPDATE... SEE DISCUSSION FOR MORNING UPDATE. && .DISCUSSION... NOT MUCH CHANGE IN PATTERN FROM YESTERDAY. SCATTERED SHOWERS AND THUNDERSTORMS HAVE FORMED OVER THE WATERS THIS MORNING AND HAVE STARTED TO MOVE INLAND. GFS AND NAM FORECAST SOUNDINGS SHOWING PWATS AROUND 1.7" THIS AFTERNOON WITH K INDICES IN THE LOWER TO MID 30S. EXPECTING COVERAGE TO INCREASE OVER INLAND AREAS THIS AFTERNOON THANKS TO DAY TIME HEATING. HIGH RES HRRR AND TEXAS TECH WRF AGAIN SHOWING GREATEST CHANCES TOWARDS THE SOUTHWEST. GRANTED THEY HAVE NOT INITIALIZED GREAT. COVERAGE MIGHT AGAIN BE MORE THAN 40 PERCENT IN SOME AREAS BUT GIVEN MESOSCALE NATURE OF STORMS HARD TO PIN POINT EXACT LOCATION. CURRENT FORECAST HAS TAKEN THE ABOVE INTO ACCOUNT. NO UPDATE REQUIRED AT THIS TIME. 23 && .PREV DISCUSSION... /ISSUED 355 AM CDT SUN JUL 6 2014/ DISCUSSION... CURRENT FCST LOOKS GOOD AND MADE VERY FEW CHANGES TO IT. EXPECT GENERAL PATTERN OF ISO/SCT PRECIP TO DEVELOP OFFSHORE LATE NIGHT & EARLY MORNING THEN TRANSITION INLAND DURING THE DAY COMPLIMENTS OF DAYTIME HEATING AND THE SEABREEZE. OVERALL COVERAGE DEPENDS ON SLIGHT VARIATIONS OF MOISTURE AVAILABILITY & LOCATION EACH DAY. SFC HIGH PRES SHOULD REMAIN CENTERED OFF TO THE EAST ALLOWING WEAK ONSHORE FLOW TO PERSIST. FURTHER ALOFT...LOOKS LIKE WE`LL REMAIN IN A SLIGHT WEAKNESS BETWEEN RIDGES. SOME OF THE MEDIUM RANGE SOLNS DO SUGGEST UPPER RIDGE BUILDING FURTHER OVERHEAD TOWARD NEXT WEEKEND WHICH WOULD BRING RAIN CHANCES DOWN AND TEMPS UP. JUST SOMETHING TO KEEP AN EYE ON - BUT PERSISTENCE FCST WILL DO FOR NOW. 47 MARINE... AS HIGH PRESSURE EDGES OFF TO THE EAST THE ONSHORE FLOW SHOULD BE IN- CREASING SLIGHTLY THE NEXT DAY OR SO. THESE LIGHT/MODERATE WINDS ARE FCST TO PERSIST FOR MUCH OF THE WEEK AS THE WX PATTERN REMAINS GENER- ALLY QUIET. NO ADVISORIES/CAUTION FLAGS ARE ANTICIPATED EXPECTED THE NEXT SEVERAL DAYS. 41 AVIATION... CALM WINDS/WET GROUNDS HELPING TO PRODUCE SOME PATCHY/SHALLOW GROUND FOG THIS MORNING. NOT EXPECTING ANY SIGNIFICANT VIS/CIG RESTRICTIONS THROUGH MID MORNING AS ALL OF THIS SHOULD MIX OUT BY THEN. OTHERWISE SHORT TERM GUIDANCE INDICATING THAT THE BEST CHCS FOR PCPN WILL BE A BIT FURTHER W/SW THIS AFTN BUT ISO ACTIVITY ALONG/NEAR THE SEABREEZE CANNOT BE TOTALLY RULED OUT (GIVEN THE TRENDS THESE LAST FEW DAYS). AS SUCH MAY ADD VCSH FOR SOME OF THE CENTRALLY LOCATED TAFS (SGR/HOU AND LBX) FOR THIS AFTN. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 93 73 93 74 93 / 20 20 30 10 20 HOUSTON (IAH) 92 74 92 75 92 / 30 20 30 10 30 GALVESTON (GLS) 89 79 89 80 90 / 30 20 20 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...23
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1127 PM CDT SAT JUL 5 2014 .AVIATION... /06Z TAFS/ VFR expected for the next 24 hours with no significant aviation concerns. May see a few stratus near JCT around sunrise...but confidence too low to add MVFR ceiling. Will also see a few afternoon cumulus...but expecting a bit less than yesterday with drier air in place. Winds should increase out of the south at 10 to 15 kt by mid-morning. && .PREV DISCUSSION... /ISSUED 624 PM CDT Sat Jul 5 2014/ AVIATION... /00Z TAFS/ VFR expected for the next 24 hours. May see just a few stratus make it into the Northwest Hill Country and JCT area...but clouds should be brief. Left a scattered group of low clouds in for a few hours around sunrise. Otherwise...light southeast winds overnight will pick up to 10 to 15 kts tomorrow more out of the south. No significant aviation weather expected. PREV DISCUSSION... /ISSUED 347 PM CDT SAT JUL 5 2014/ SHORT TERM... (Tonight and Sunday) Cumulus development was more extensive over West Central Texas than yesterday. While the 17Z HRRR model reflectivity did indicated isolated shower and thunderstorm activity this afternoon, cumulus at 3 PM had limited vertical extent, and expect dry conditions this evening. Dry conditions continue Sunday as upper ridging holds over the region. Will maintain a persistence forecast, with lows in the lower 70s and highs in the mid 90s. LONG TERM... (Sunday night through next Saturday) Warm and dry conditions will continue across West Central Texas through next week. The center of the upper high will remain over the four corners region through midweek, then flatten and expand east across the Southern Plains through next Saturday. Models still show a weak TUTT moving into extreme south Texas and far northeastern Mexico by Wednesday. This feature will remain nearly stationary across this area through Thursday, then drift slowly west across Northern Mexico by early next weekend. About the only noticeable effect from the TUTT will be an increase in some diurnal cumulus by mid to late week. Temperatures through the extended period will remain at or slightly above seasonal normals for this time of year. && .PRELIMINARY POINT TEMPS/POPS... Abilene 72 94 71 96 72 / 5 5 5 5 5 San Angelo 72 95 69 96 72 / 5 5 5 5 5 Junction 69 94 70 95 70 / 5 5 5 5 5 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 08
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
732 PM EDT MON JUL 7 2014 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY AND SPILL SLOWLY SOUTHEAST INTO THE AREA ON WEDNESDAY. THIS COMBINED WITH DAYTIME HEATING AND INCREASING MOISTURE...WILL BRING AN INCREASING THREAT FOR SCATTERED SHOWERS AND THUNDERSTORMS...FIRST IN THE FAR WEST TUESDAY...AND THEN FOR MUCH OF THE AREA BY WEDNESDAY. THE FRONT WILL STRUGGLE TO CLEAR THE PIEDMONT AREAS ON THURSDAY. && .NEAR TERM /THROUGH TUESDAY/... AS OF 350 PM EDT MONDAY... INCREASING MOISTURE IN SW FLOW THIS AFTERNOON WITH EXPANSICE CU FIELD ACROSS MOST AREAS...BUT AT 330 PM EDT RADAR SHOWING NO ECHOES IN BLACKSBURG CWA...CLOSEST IN FAR SOUTHERN NC. WILL KEEP A SLIGHT CHC POP FOR LATE AFTERNOON THROUGH SOME OF EVENING AND EXPAND A LITTLE FARTHER NORTH MAINLY ALONG BLUE RIDGE AND ALSO HIGHER ELEVATIONS OF GREENBRIER AND ALLEGHANY HIGHLANDS GIVEN WHERE MAX SBCAPES ARE THIS AFTERNOON AND LATEST HRRR SUGGESTING ANY ISOLD POP UPS NOW MORE ACROSS CENTRAL PART OF FCST AREA. LOW CONFIDENCE THAT ANYTHING WILL ACTUALLY POP UP...AND ANY CELLS MAY NOT EVEN BE ABLE TO PRODUCE THUNDER...BUT DO NOT FEEL COMFORTABLE WITH NOTHING MENTIONED IN THESE AREAS THROUGH THIS EVENING. OTHERWISE ANY CONVECTION WILL DIE QUICKLY WITH LOSS OF HEATING AND LOOKING AT TRENDS IN CONVECTION UPSTREAM VIA SATELLITE AND RADAR...THINKING THAT MOST MODELS OVERDOING AMOUNT OF CONVECTION AND THUS DEBRIS CLOUDINESS THAT COULD REACH INTO FAR WESTERN PORTIONS LATER TONIGHT. ONLY MODELS THAT SUGGESTION SOME LINGERING ACTIVITY SNEAKING INTO FAR WEST ARE THE ONES THAT TEND TO OVERDUE IT...AND INSTABILITY AFTER MIDNIGHT IS NON-EXISTANT...SO MAINTAINING ONLY A VERY SLIGHT CHC POP FAR NW LATE TONIGHT AND TRENDED DOWN ON CLOUD COVER A BIT MOST OF THE OVERNIGHT ACROSS THE WEST...WITH MOSTLY CLEAR ALL FAR BUT FAR WESTERN FRINGES. WENT WITH COOLER GUIDANCE AGAIN FOR LOWS...BUT STILL A BIT MILDER THAN PREVIOUS NIGHT...ESPECIALLY WEST WHERE THERE WILL BE A LITTLE CLOUD COVER MOVING IN LATE. TUESDAY CONVECTIVE CHANCES AND TIMING IS TOUGH WITH FRONT APPROACHING FROM WEST LATE BUT EFFECTIVE DAYTIME HEATING EARLY WITH LITTLE CAP TO HOLD CONVECTION BACK. THINKING THAT SOME ISOLATED CONVECTION COULD FIRE OVER HIGHER TERRAIN FROM BLUE RIDGE WEST RATHER EARLY...PERHAPS BY NOON...BUT MID LEVEL DRY AIR INITIALLY WILL KEEP THIS LIMITED. THEN WITH INCREASING SHEAR AND FORCING BACK ALONG FRONT TO THE WEST...MORE ORGANIZZED CONVECTION EXPECTED TO MOVE IN LATE. SOME HIGH RES MODELS AS WELL AS NAM SUGGEST TWO SEPARATE WAVES...WITH ONE BROKEN LINE OR CLUSTERS MOVING IN TO SE WV BY LATE AFTERNOON BUT WEAKENING QUICKLY ON WESTERN SLOPES...WITH ANOTHER PERHAPS MORE SIGNIFICANT LINE OF STORMS MOVING THROUGH KENTUCKY BY EVENING AND APPROACHING FAR SW VA AND NW NC LATER IN THE EVENING...BUT ALSO WEAKENING QUICKLY DUE LARGELY TO LOSS OF INSTABILITY. OVERALL LOW CONFIDENCE IN THESE DETAILS...BUT TRENDED TOWARD SLOWER ARRIVAL OF MID CHC TO LIKELY POPS UNTIL VERY LATE IN THE DAY...WITH OTHERWISE SLIGHT CHC FROM FOOTHILLS WEST FROM MIDDAY ON. GIVEN LATE TIMING AND WEAKENING NATURE OF STORMS...THINK SEVERE POTENTIAL IS LOW...BUT NOT ZERO. SPC SLIGHT RISK INTO WESTERN THIRD OF AREA WOULD BE MAINLY FOR EVENING...AND THINK THIS WOULD MAINLY BE FOR DAMAGING WINDS AS MOST DEEPER CORES WILL BE COLLAPSING AS THEY MOVE INTO OUR AREA...AND LINE CLUSTERS AND BOWING SEGMENTS ARE MOST LIKELY STORM MODE. ANY ISOLD CONVECTION AHEAD OF THIS EARLIER IN UNCAPPED ENVIRONMENT IS NOT LIKELY TO REACH SEVERE LIMITS. ANOTHER HOT DAY IN THE EAST WITH HIGHS AGAIN IN THE 90S AIDED BY SOME DOWNSLOPE AND LITTLE CHANCE FOR PRECIP AND MUCH IN THE WAY OF CLOUD COVER...AND LOW TO MID 80S IN WEST WITH LESS CONFIDENCE IN SOME OF THESE HIGHS SINCE IT WILL DEPEND ON CLOUD COVER AND CONVECTIVE COVERAGE AND TIMING. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... AS OF 330 EDT MONDAY... ALTHOUGH A BULK OF THE BEST VORTICITY ADVECTION REMAINS NORTHWEST OF THE FORECAST AREA...UPPER TROF AXIS CROSSES THE REGION ON WEDNESDAY AND MODELS STILL SHOWED FORECAST AREA IN THE RIGHT REAR QUADRANT OF THE UPPER JET TUESDAY NIGHT AND WEDNESDAY. WILL KEEP THESE TWO PERIODS AS THE TIME WITH THE HIGHEST PROBABILITY OF PRECIPITATION. CLOUDS WILL LIMIT TEMPERATURE DROP TUESDAY NIGHT AND AMOUNT OF INSTABILITY ON WEDNESDAY. WHILE THE SYNOPTIC FORCING IS GOOD...THE LACK OF HEATING WEDNESDAY MORNING AND DOWNSLOPING FROM A WEST WIND MAY SUPPRESS THE COVERAGE OF THUNDERSTORMS IN ALL BUT THE FAR SOUTHEAST COUNTY WARNING AREA...DEPENDING ON WHERE OUTFLOW FROM THUNDERSTORMS ON TUESDAY END UP. HAVE LOWERED CHANCE IN THE NORTHWEST. BY WEDNESDAY NIGHT THE COLD FRONT WILL BE THROUGH THE FORECAST AREA ENOUGH TO CONFINE PROBABILITY OF PRECIPITATION TO THE FAR SOUTHEAST BUT DURING THE DAY THURSDAY WEAK EAST FLOW MAY BE ENOUGH TO TRIGGER SHOWERS AND THUNDERSTORMS ALONG THE FOOTHILLS AND INTO THE PIEDMONT. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 300 PM EDT MONDAY... UPPER PATTERN IS AGAIN BECOMING ZONAL THURSDAY NIGHT AND FRIDAY BUT MODELS WERE BRINGING A SHORT WAVE THROUGH THE BASE OF THE EASTERN TROF AND ACROSS THE MID ATLANTIC REGION THURSDAY NIGHT. THE 500 MB TROF DEEPENS AGAIN ON SUNDAY AND MONDAY. SURFACE FRONT IS WELL TO THE SOUTHEAST OF THE FORECAST AREA THURSDAY NIGHT AND FRIDAY BUT ANY WAVE ALONG THE FRONT MAY BRING DEEPER MOISTURE AND A HIGHER PROBABILITY OF PRECIPITATION BACK TOWARD THE SOUTHERN COUNTY WARNING AREA. FORECAST AREA WILL RETURN TO WARM...HUMID...UNSTABLE AIR...AND THE ASSOCIATED CHANCE OF THUNDERSTORMS...SUNDAY AND MONDAY AHEAD OF THE NEXT COLD FRONT. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 732 PM EDT MONDAY... MEDIUM TO HIGH CONFIDENCE FORECAST THIS TAF PERIOD. COMMS ISSUES REMAIN AT KDAN DESPITE AN INTERMITTENT RETURN OF OBSERVATION DATA. AMD NOT SKED CONTINUED IN THE TAF...ALTHOUGH VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. VFR CONDITIONS WILL PREVAIL THIS EVENING INTO TONIGHT. LOW LEVEL THTE FIELDS SHOW A SEPARATION BETWEEN SOME MOISTURE RUNNING UP THROUGH THE PIEDMONT TONIGHT AND MOISTURE ASSOCIATED WITH APPROACHING FRONT FROM THE NW. KDAN MAY SEE A PERIOD OF BKN VFR CIGS OVERNIGHT WITH THE PIEDMONT MOISTURE AND BELIEVE SCT CLOUDS WILL HOLD ELSEWHERE...BUT KLWB AND KBLF MAY SEE BORDERLINE VFR CIGS TUESDAY MORNING. ANTICIPATING LOW/MID LEVEL CLOUDS MOVING IN FROM THE WEST AND THIS MAY HELP KEEP FOG FORMATION IN CHECK TONIGHT AT KLWB AND KBCB...BUT IF CLOUDS DO NOT MATERIALIZE FOG MAY BE MORE AGGRESIVE THAN INDICATED. CU COULD DEVELOP INTO A BORDERLINE VFR CIG BY LATE MORNING AT KBCB/KBLF/KLWB. BELIEVE BETTER CHANCES FOR CONVECTIVE WILL BE AFTER 18Z AS THE COLD FRONT APPROACHES FROM THE WEST. ADDED THE MENTION OF VCTS IN THE WESTERN MOUNTAINS TUESDAY AFTERNOON INTO THUESDAY EVENING. IN GENERAL...SOUTHWEST WINDS WILL CONTINUE TO WEAKEN THIS EVENING INTO TONIGHT. WINDS MAY KEEP UP AT THE HIGHER ELEVATIONS LIKE BLF OVERNIGHT. BETTER CHANCES OF MORE ORGANIZED CONVECTION POSSIBLE LATE TUESDAY AFTERNOON INTO TUESDAY EVENING. EXTENDED AVIATION... BEST CHANCE FOR THUNDERSTORMS LOOKS TO BE ON WEDNESDAY WITH THE BEST PUSH OF UPPER DYNAMICS TO NUDGE THE SFC BOUNDARY THROUGH THE AREA. BUT THE FRONT WILL LINGER IN OUR VICINITY THROUGH THE END OF THE WEEK WITH IMPULSES RIDING ALONG IT. THIS WILL KEEP UNSETTLED CONDITIONS AT TAF SITES THROUGH THE END OF THE WEEK. EXPECT DIURNAL TRENDS FOR AFTERNOON CONVECTIVE PRECIPITATION WITH ASSOCIATED MVFR OR LOWER CONDITIONS... ESPECIALLY FOR KDAN/KLYH...AND POSSIBLE IFR FOG LATE NIGHTS...MAINLY KBCB AND KLWB. && .EQUIPMENT... COMMS ISSUES WITH KDAN ASOS TRANSMITTING OUT. THE FAA IS AWARE OF THE OUTAGE AND WILL BE WORKING ON IT...BUT NO ESTIMATED TIME OF WHEN IT WILL BE WORKING AGAIN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/SK NEAR TERM...SK SHORT TERM...AMS LONG TERM...AMS AVIATION...JH/KK/MBS EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
905 PM CDT MON JUL 7 2014 .UPDATE...TRUNCATED DISCUSSION DUE TO NEAR SEVERE/SEVERE IN AREA. WILL CONTINUE MID TO HIGH RANGE POPS FOR CONVECTION THROUGH THE LATE NIGHT AS UPSTREAM COLD FRONT APPROACHING SOUTHERN WI. BULK SHEAR HAS BEEN INCREASING WITH APPROACHING MID-LEVEL SHORT WAVE AND MUCAPE REMAINS BETWEEN 1000 AND 3000 J/KG. HENCE SEVERE WX THREAT CONTINUES IN WEST. && .AVIATION/06Z TAFS/...STILL EXPECT A PERIOD OF CONVECTION TO AFFECT TAF SITES LATE IN THE EVENING THROUGH THE OVERNIGHT. && .PREV DISCUSSION... /ISSUED 319 PM CDT MON JUL 7 2014/ SHORT TERM... TONIGHT...FORECAST CONFIDENCE MEDIUM. MAIN FOCUS WILL BE ON CONVECTIVE TRENDS. DRIER AIR HAS ARRIVED IN THE WAKE OF THE FRONT THAT SHIFTED SOUTHEAST OF WI LATE LAST NIGHT. AXIS OF HIGHER MLCAPE HAS TAKEN SHAPE ACRS PARTS OF NRN WI AHEAD OF A SURFACE TROUGH AND ALSO FROM IA INTO SRN MN WITH BETTER RETURN FLOW THERE. STORMS FIRING FROM NW WI INTO EC MN. THESE ARE TRENDING ESE THOUGH AIRMASS MORE STABLE IN SRN WI. LATEST HRRR SHOWS AXIS OF ONGOING ACTIVITY DROPPING INTO SW WI AS THE EVENING GOES ON WITH STRONGER CELLS STAYING JUST NW OR W OF CWA WITH WEAKER SHOWERS/ISOLD TSRA SPREADING INTO SRN WI. HOWEVER VERY IMPRESSIVE JET PATTERN TAKES SHAPE AS THE EVENING AND OVERNIGHT PROGRESS. 12Z NAM SHOWS A NEARLY COUPLED JET STRUCTURE EVOLVING WITH MASSIVE DIVERGENCE. SO FAVORABLE UPPER JET STREAM WILL CERTAINLY BE A FACTOR. 500 MILLIBAR SHORTWAVE WILL BE APPROACHING WITH DIFFERENTIAL CYCLONIC VORTICITY ADVECTION. THERE WILL BE SOME RECOVERY IN MOISTURE WITH RENEWED 25 TO 35 KNOT SOUTHWEST 850 JET ARRIVING TOWARDS 06Z. BETTER CONVECTIVE POTENTIAL PROGGD TO AFFECT SRN WI IN THE 02-11Z TIME FRAME. GFS SHOWS 0-6 KM SHEAR 50 KNOTS PLUS BY 06Z. SSEO SHOWS BETTER UPDRAFT HELICITY FURTHER WEST THEN DECREASING INTO THE CWA. BUFKIT SOUNDINGS NOT SHOWING A MASSIVE AMOUNT OF CAPE COMING INTO PLAY BUT THERE WILL BE A RETURN FLOW AHEAD OF THIS SYSTEM SO EXPECT THE BEST OVERLAP OF FORCING/THERMODYNAMICS TO BE IN SC WI CLOSER TO SWODY1 AREA OF CONCERN. THE LATEST HRRR IS CERTAINLY A WEAKER SOLUTION THAN THE 12Z NMM AND 12Z ARW. ALL OF THE SHRA/TSRA WILL LIKELY EXIT SE WI AROUND 12Z PLUS OR MINUS AN HOUR. TUESDAY...FORECAST CONFIDENCE MEDIUM. STRONGLY CYCLONIC FLOW WILL PERSIST. SO THIS WILL LIKELY SET UP SOME PRETTY DECENT LAPSE RATES RESULTING IN MORE SHRA/TSRA ACTIVITY. HIGHEST POPS WILL BE PLACED IN THE NE CWA. 925 TEMPS DROP INTO THE TEENS IN THE WAKE OF THIS LATEST FRONT. SO HIGHS WILL DROP BACK INTO THE 70S. TUESDAY NIGHT THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE HIGH. AN UPPER TROUGH WILL SWING ACROSS THE NRN GREAT LAKES FOR TUE NT AND WED AM. THIS MAY ALLOW ISOLD TO SCT INSTABILITY SHOWERS TO CONTINUE FROM TUE AFTERNOON INTO TUE NT OVER EAST CENTRAL WI. THE UPPER TROUGH WILL BE MOVING AWAY FOR WED WITH HEIGHT RISES. THERE WILL REMAIN ENOUGH COLD AIR ALOFT FOR SCT-BKN CUMULUS WITH POSSIBLY SOME SPRINKLES OVER EAST CENTRAL WI. HIGH PRESSURE TO THEN PREVAIL WED NT INTO THU AM. SLY WINDS TO THEN DEVELOP THU AFTERNOON AS SHORTWAVE RIDGING OCCURS AHEAD OF AN APPROACHING SHORTWAVE TROUGH FROM THE NRN PLAINS. TEMPS WILL BE BELOW NORMAL BUT PLEASANT. PWS TO REMAIN BELOW ONE INCH WITH VERY COMFORTABLE HUMIDITY. LONG TERM...FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM. THERE WILL BE GOOD CHANCES OF SHOWERS AND TSTORMS FRIDAY AFTERNOON AND NIGHT AS A SLOW MOVING SHORTWAVE TROUGH MOVES ESEWD ACROSS THE STATE WITH SLY WINDS AND MOISTURE TRANSPORT AHEAD OF IT. MUCH UNCERTAINTY FOR THE WEEKEND WITH QUASI-ZONAL FLOW AND THE POTENTIAL FOR A W-E STATIONARY FRONT OVER SRN WI OR NEARBY ON SOME OF THE MODELS. THE UNCERTAINTY WILL CONTINUE INTO EARLY NEXT WEEK ON THE DEGREE OF SOUTHWARD DIGGING OF A CANADIAN POLAR TROUGH. WENT WITH CHANCES OF SHOWERS/TSTORMS THROUGH THE WEEKEND AND MONDAY WITH TEMPS AT OR SLIGHTLY BELOW NORMAL. AVIATION/00Z TAFS/...VFR INTO THIS EVENING WITH JUST A FEW CU AND SOME INCREASE IN HIGH CLOUDS FROM MN/IA. LOOKING AT A 02-11Z AS THE GENERAL WINDOW FOR STORMS...STARTING IN THE WEST AT 02-04Z AND WRAPPING UP AT THE 11Z TIME IN THE FAR SOUTHEAST. UPPER JET WILL BE A FACTOR SO STORMS EXPECTED TO SURVIVE TO THE EAST DESPITE GETTING INTO THE DIURNALLY LESS FAVORABLE TIMEFRAME. ANY LOWER CIGS AND VSBYS EXPECTED TO BE BRIEF AS STORMS WILL BE MOVING ALONG WITH THE STRONGER FLOW UPSTAIRS. SLIGHT RISK WAS EXPANDED A BIT FURTHER EAST INTO SC WI SO KMSN MORE VULNERABLE TO A SVR STORM THAN THE EASTERN TAF SITES. UPPER FLOW REMAINS CYCLONIC ON TUESDAY SO CHCY POPS FOR SHRA/TSRA. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
610 PM CDT MON JUL 7 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 203 PM CDT MON JUL 7 2014 MAIN SHORT TERM CONCERN IS ON SEVERE POTENTIAL THROUGH THE EVENING. CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA WHILE TROUGHING PRESIDED OVER EASTERN CANADA. THE MAIN FEATURE OF INTEREST WAS A FAIRLY POTENT SHORTWAVE AT THE SOUTHWEST END OF THIS TROUGHING OVER NORTH DAKOTA. A CLUSTER OF SHOWERS AND THUNDERSTORMS CONTINUES TO ROLL AHEAD OF THE SHORTWAVE IN THE DPVA REGION...BEING ENHANCED NOW BY DAYTIME HEATING. THERE IS ALSO AN UPPER JET STREAK GOING FROM MONTANA INTO SOUTH DAKOTA...PROVIDING UPPER DIVERGENCE FOR THOSE STORMS. CLOSER TO THE FORECAST AREA...SHOWERS AND THUNDERSTORMS HAVE BEEN DEVELOPING FROM CENTRAL MN INTO THE NORTH HALF OF WI. A WEAK SHORTWAVE TRAVERSING THROUGH THE FLOW...COMBINED WITH WEAK MID LEVEL FRONTOGENESIS AND 1000 J/KG OF UNCAPPED MLCAPE PER RAP ARE CONTRIBUTING TO THEIR DEVELOPMENT. HAVE HAD A FEW ISOLATED SEVERE SUPERCELLS DEVELOP TOO. ANOTHER PLUME OF LITTLE HIGHER INSTABILITY...1000-2000 J/KG PER RAP...WAS EVIDENT ACROSS NORTH CENTRAL IOWA STREAMING NORTHEASTWARD ASSOCIATED WITH CORN EVAPOTRANSPORATION. TEMPERATURES HAVE CLIMBED NICELY DUE TO CLEAR SKIES THIS MORNING AND HAVING 850MB TEMPS OF 15-18C. MAIN SURFACE COLD FRONT EXTENDED FROM NORTHERN MN INTO EASTERN SOUTH DAKOTA. THE POTENT SHORTWAVE OVER NORTH DAKOTA IS FORECAST TO MOVE SOUTHEAST ACROSS THE FORECAST AREA OVERNIGHT TONIGHT. IN RESPONSE...THERE ARE SOME VERY IMPRESSIVE 500MB HEIGHT FALLS FOR EARLY JULY...ON THE ORDER OF 60-80 METERS IN 12 HOURS. NEEDLESS TO SAY...THERE IS PLENTY OF DYNAMIC FORCING COMING ACROSS THIS EVENING. ADDITIONALLY...THAT UPPER JET STREAK GOING ACROSS SOUTH DAKOTA NOW SHOULD SLIDE JUST TO OUR SOUTH IN IOWA...PROVIDING UPPER DIVERGENCE SUPPORT. THROW IN LINGERING AFTERNOON INSTABILITY AND THIS PROVIDES A GREAT RECIPE FOR CONVECTION THIS EVENING. MAJORITY OF DETERMINISTIC AND HIGH RESOLUTION MODELS AGREE AS WELL...WITH A MAX PRECIPITATION COVERAGE TIME LIKELY CENTERED NEAR 03Z. THE GREATEST SEVERE POTENTIAL WILL EXIST MOSTLY BETWEEN 23-03Z... WHEN THE DYNAMICS ARE JUXTAPOSED ON TOP OF THE THERMODYNAMICS...AND STORMS CAN MAINTAIN SOME ISOLATION OF INFLOW. STILL COULD HAVE SOME ISOLATED SEVERE BEFORE THEN LIKE WE ARE OBSERVING NOW. 0-3KM AND 0-6 KM SHEAR STILL REMAIN FAVORABLE FOR ORGANIZED SEVERE CONVECTION...30- 35 KT AND 40-55 KT RESPECTIVELY. HODOGRAPHS ARE MAINLY STRAIGHT LINE...SUGGESTING SPLITTING SUPERCELLS...WHILE THE SHEAR ALSO FAVORS BOWING LINE SEGMENTS. GIVEN A MAINLY UNIDIRECTIONAL FLOW FROM SURFACE TO THE MID LEVELS...BELIEVE DAMAGING WINDS AND LARGE HAIL ARE THE MAIN CONCERNS. STRONG SUBSIDENCE IN THE WAKE OF THE POTENT SHORTWAVE OVERNIGHT SHOULD HELP TO CLEAR THE PRECIPITATION WEST TO EAST. THE FORECAST AREA COULD BE COMPLETELY DRY BY 09Z. ATTENTION THEN TURNS TO THE UPPER TROUGH SET UP FROM NORTHERN ONTARIO SOUTHWARD THROUGH THE WESTERN GREAT LAKES REGION ON TUESDAY. THE COLD POOL ASSOCIATED WITH THIS TROUGH...REFLECTED BY 500MB TEMPS OF -13 TO -15C...COULD BE ENOUGH TO INSTIGATE SOME SHOWERS AND THUNDERSTORMS WITH DAYTIME HEATING. HOWEVER...THERE ARE SOME ISSUES THAT WOULD FAVOR A DRIER FORECAST. FIRST...MODELS AGAIN ARE LIKELY OVERDOING SURFACE DEWPOINTS AND INSTABILITY...ESPECIALLY GIVEN A NORTHWEST FLOW WOULD FAVOR A GOOD DRYING/MIXING SCENARIO. SECOND...SHORTWAVES ROTATING THROUGH THE UPPER TROUGH APPEAR TO TRACK NORTH OF THE FORECAST AREA. THUS...HAVE ONLY KEPT PRECIPITATION CHANCES IN THE 20-30 RANGE. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 203 PM CDT MON JUL 7 2014 A NICE DRY PERIOD IS EXPECTED FOR THE FORECAST AREA TUESDAY NIGHT THROUGH THURSDAY...RESULTING FROM THE UPPER TROUGH GRADUALLY SHIFTING EAST...UPPER RIDGING EVENTUALLY BUILDING INTO THE AREA BY 00Z FRIDAY...AND SURFACE RIDGING BUILDING IN. PRECIPITABLE WATER IS ALSO FORECAST BETWEEN 0.5-1 INCH...OR ANYWHERE FROM 50-100 PERCENT OF NORMAL...SUPPORTING A DRY FORECAST AND ALSO ALLOWING FOR LARGER DIURNAL SWINGS. NIGHTTIME LOWS COULD GET RELATIVELY CHILLY WEDNESDAY NIGHT IN CENTRAL WISCONSIN WITH THE SURFACE RIDGE OVERHEAD. THEREFORE IT ALSO SEEMS TO BE THE BEST NIGHT TO HAVE TRIBUTARY VALLEY FOG. THE WEATHER THEN STARTS TO POSSIBLY TURN MORE ACTIVE AGAIN LATE THURSDAY NIGHT AND RIGHT INTO THE WEEKEND. THIS IS A RESULT OF VERY GOOD MOISTURE RETURN...CHARACTERIZED BY PRECIPITABLE WATER UPWARDS OF 1.5-1.8 INCHES...FLOWING BACK INTO THE AREA ON THE BACK SIDE OF THE SURFACE HIGH. MEANWHILE...IN THE SYNOPTIC SCALE...AN UPPER TROUGH IS PROGGED TO DROP SOUTH OUT OF CANADA INTO OUR REGION. SOME OF THE DETAILS ARE HARD TO PIN DOWN RIGHT NOW...BUT CERTAINLY FROM LATE THURSDAY NIGHT THROUGH SUNDAY THERE COULD BE OFF AND ON SHOWERS AND THUNDERSTORMS AROUND. THIS CREATES SOME UNCERTAINTY ON TEMPERATURES...ESPECIALLY GIVEN THAT AT LEAST FRIDAY 850MB TEMPS ARE 15-18C AND COULD BE SIMILAR ON SATURDAY. NOTE THAT A GENERAL COOLING IS EXPECTED HEADING INTO EARLY NEXT WEEK...ESPECIALLY IF THE 07.00Z/12Z ECMWF RUNS ARE RIGHT WHERE THEY SHOW 850MB TEMPS FALLING TO 6C ON MONDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 610 PM CDT MON JUL 7 2014 SHRA/TS GOING TO ROLL SOUTHEAST ACROSS THE AREA THROUGH 03Z. SOME WILL BRING STRONG NORTHWESTLY WINDS...GUSTS COULD EXCEED 40 MPH...MORE IF THE LINE BECOMES SEVERE. COULD SEE A BRIEF DIP INTO IFR/MVFR CONDITIONS WITH THE STORMS. VFR CONDITIONS EXPECTED AFTER THE STORMS EXITS AND THE RESPONSIBLE UPPER LEVEL SHORTWAVE SHIFTS EAST. SOME HINTS VIA THE NAM THAT THERE COULD BE A PERIOD OF MVFR CIGS...ALTHOUGH CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE AT THIS TIME. WILL HAVE TO MONITOR AND MAKE UPDATES TO THE FORECAST AS NEEDED. && .HYDROLOGY... ISSUED AT 203 PM CDT MON JUL 7 2014 THE MISSISSIPPI RIVER CONTINUES TO FALL. IN FACT...WE ARE EXPECTING ALL THE RIVER FORECAST POINTS WITHIN THE ARX FORECAST AREA TO FALL BELOW FLOOD STAGE BY THURSDAY FROM NORTH TO SOUTH. FLOOD WARNINGS HAVE BEEN CANCELLED AT WINONA AND LA CROSSE AND WILL SOON BE AT WABASHA. PERIODIC RAIN IS FORECAST OVER THE NEXT FEW DAYS...BUT IT APPEARS THIS RAINFALL WILL NOT BE ENOUGH TO HAVE A SIGNIFICANT IMPACT ON THE MISSISSIPPI...OR ITS TRIBUTARIES FOR THAT MATTER. FOR THE CURRENT AND FORECAST RIVER LEVELS...SEE OUR INTERNET PAGE AT WWW.WEATHER.GOV/LACROSSE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM....AJ AVIATION.....RIECK HYDROLOGY....AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
550 PM CDT SUN JUL 6 2014 .MESOSCALE DISCUSSION... ISSUED AT 331 PM CDT SUN JUL 6 2014 NUMEROUS SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP ALONG AND NORTH OF INTERSTATE 90...ESPECIALLY IN WISCONSIN. THESE ARE ON THE NOSE OF 850MB MOISTURE TRANSPORT AND BASICALLY THE FINE LINE BACK EDGE IS THE 850MB FRONT DEPICTED IN RAP ANALYSIS. THE STRONGEST CORE HAS BEEN OVER TREMPEALEAU COUNTY...AND DOES HAVE SOME MID- LEVEL ROTATION...HOWEVER MUCH OF THE CORE APPEARS TO BE RAIN. NOT ANTICIPATING ANY OF THIS ELEVATED DRIVEN CONVECTION TO TURN SEVERE. FARTHER TO THE WEST...STILL MONITORING FOR SHOWERS AND THUNDERSTORMS TO DEVELOP FROM NORTH CENTRAL IOWA TO SOUTH CENTRAL MN AND WEST CENTRAL WI. SEEING A TOWERING CUMULUS LINE ON VISIBLE IMAGERY...BUT OVERALL DEEP- MOISTURE AND EVEN SURFACE CONVERGENCE ALONG THIS TROUGH IS WEAK. LOOKING AT THE SURFACE FLOW...IT GOES SOUTHWEST AT RST TO NEARLY WEST AT I-35 TO NORTHWEST AT NEW ULM...A LONG DISTANCE. RAP ANALYSIS DOES SHOW 2500-3500 J/KG OF MLCAPE WITH LITTLE CIN IN THIS CORRIDOR...THOUGH. THUS...A WAIT AND SEE IF ANYTHING CAN POP. SHOULD A STORM FIRE...IT WILL PROBABLY TURN SEVERE QUICKLY. NEEDLESS TO SAY...THE COMBINATION OF THE LONG PERIOD OF HAVING THE STRATUS AROUND TODAY AND NOT A LOT OF CONVERGENCE ON THE FRONT HAVE BEEN DETRIMENTAL TO SEVERE POTENTIAL. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 201 PM CDT SUN JUL 6 2014 MAIN SHORT TERM CONCERNS ARE ON CONVECTIVE EVOLUTION AND SEVERE POTENTIAL FOR THIS AFTERNOON/EVENING AND AGAIN LATE MONDAY. CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED STRONG RIDGING OVER THE WESTERN U.S. WHILE GENERAL WEAK TROUGHING PRESIDED OVER THE GREAT LAKES. A WEAK SHORTWAVE WAS EVIDENT OVER CENTRAL MN. ACCOMPANYING THIS SHORTWAVE PER THE RAP AT 800MB WERE 30 KT NORTHWEST WINDS AND 14-15C TEMPERATURES. COMPARE THIS TO 25-30 KT SOUTHWEST WINDS AND 18-20C TEMPERATURES OVER THE FORECAST AREA. THAT WARM NOSE COMBINED WITH MORNING STRATUS AND DEBRIS CLOUDS HAS KEPT CONDITIONS CAPPED THUS FAR. EDGE OF CAP REFLECTED NICELY TOO BY SOME ELEVATED SHOWERS AND THUNDERSTORMS GOING ON OVER WEST-CENTRAL WISCONSIN. TEMPERATURES FOR THE MOST PART HAVE BEEN STUCK IN THE 70S WITH A FEW 80S WHERE CLEARING BRIEFLY OCCURRED IN SOUTHEAST MN AND WEST CENTRAL WI. DEWPOINTS HAVE BEEN ON THE RISE...THOUGH...NOW IN THE LOW 70S. BACK IN WESTERN IA... EVAPOTRANSPORATION PUSHING DEWPOINTS THERE IN THE UPPER 70S. THINKING THESE HIGHER DEWPOINTS ADVECTING TOWARDS THE AREA IS NOT HELPING MATTERS TO CLEAR THE STRATUS. THE AFOREMENTIONED TEMPERATURES AND DEWPOINTS HAVE RESULTED IN MLCAPE VALUES OF 1500- 2010 J/KG WHILE MLCIN SITS 50-100 J/KG WHERE IT CLEARED TO 201-300 J/KG WHERE ITS STILL CLOUDY. MEANWHILE...IN SOUTHWEST MN... DEWPOINTS HAVE FALLEN OFF INTO MID LOW 50S BEHIND A TROUGH/DRYLINE THAT STRETCHES FROM NORTHWEST IOWA INTO NORTHWEST WI. ANTICIPATING CONVECTION TO FIRE IN THE NEXT 1-2 HOURS ALONG THE TROUGH/DRYLINE NEAR/WEST OF THE FORECAST AREA AS DAYTIME HEATING CONTINUES TO GET RID OF THE CIN. CONVECTION SHOULD TAKE ON A SCATTERED NATURE GIVEN THE CAP IN PLACE. WHERE CONVECTION DOES FIRE...0-3KM AND 0-6KM SHEAR ARE ON THE ORDER OF 20-25KT... WHICH SHOULD FAVOR MORE MULTI-CELLULAR ACTIVITY. GIVEN THE AMOUNT OF CAPE...CANNOT RULE OUT AN INITIAL SUPERCELL...BUT THINKING MORE INTENSE MULTI-CELLS ARE MORE LIKELY. LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN CONCERNS. GENERAL MODEL CONSENSUS OF BOTH DETERMINISTIC AND HIGH RESOLUTION MODELS SUGGEST MUCH OF THE CONVECTION SHOULD BE SOUTHEAST OF THE FORECAST AREA BY 01-02Z. HOWEVER...THERE IS POTENTIAL THAT THE CONVECTION DOESNT EVEN MAKE IT INTO THE SOUTHEAST END OF THE FORECAST AREA BECAUSE OF THE MASSIVE AMOUNT OF CIN RIGHT NOW IN PLACE. MANY HRRR RUNS TODAY HAVE SHOWN THIS. MUCH OF TONIGHT AND INTO MONDAY MORNING THEN LOOKS DRY AS UNIDIRECTIONAL NORTHWEST FLOW FROM THE SURFACE TO 500MB BRINGS IN SOMEWHAT COOLER AND DRIER AIR IN FROM NORTH DAKOTA. THIS IS REFLECTED WELL IN GOES PRECIPITABLE WATER IMAGERY WHICH SHOWS VALUES OF 1 INCH OR LESS OVER WESTERN MN COMPARED TO 1.5-1.75 INCHES OVER THE FORECAST AREA. HEADING INTO MONDAY AFTERNOON...A LONG WAVE SHORTWAVE TROUGH IS PROGGED TO DROP INTO THE EASTERN DAKOTAS AND WESTERN MN. INCREASING 850MB MOISTURE TRANSPORT AHEAD OF THE TROUGH...COMBINED WITH 1000- 1500 J/KG OF MLCAPE WITH LITTLE CAPPING AND A SURFACE TROUGH MOVING THROUGH...SHOULD RESULT IN A DECENT AMOUNT OF CONVECTION ACROSS MINNESOTA IN THE AFTERNOON HOURS...AS DEPICTED TOO BY DETERMINISTIC AND HIGH RESOLUTION GUIDANCE. THIS CONVECTION COULD SPREAD INTO THE NORTHWEST HALF OF THE FORECAST AREA BY LATE IN THE DAY. GIVEN 0-3KM SHEAR VALUES OF 25-35 KT AND MORE IMPORTANTLY 0-6KM SHEAR VALUES OF 40-55 KT...ORGANIZED SEVERE CONVECTION STILL APPEARS POSSIBLE. COULD END UP SEEING A MIX OF SUPERCELL AND LINE SEGMENTS...THOUGH THE SHEAR BEING UNIDIRECTIONAL MAY FAVOR MORE LINE SEGMENTS AND THUS DAMAGING WINDS. NEED TO WATCH THE LARGE HAIL CONCERN INITIALLY TOO GIVEN LOWER FREEZING LEVELS...DROPPING FROM NEAR 14000 FT THIS AFTERNOON TO 12010 FT LATE MONDAY. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 201 PM CDT SUN JUL 6 2014 MAIN HIGHLIGHTS FOR THE LONG TERM PERIOD ARE SEVERE POTENTIAL MONDAY EVENING FOLLOWED BY COOLER WEATHER FOR MID-WEEK. MONDAY NIGHT...BOTH THE LONG WAVE SHORTWAVE TROUGH AT 500MB AND THE ASSOCIATED SURFACE TROUGH ARE PROGGED TO MOVE SOUTHEAST THROUGH THE REGION. THERE ALSO APPEARS TO BE A POINT IN THE EVENING WHERE WE GET INTO A LEFT EXIT REGION OF AN UPPER JET STREAK. COMBINE THIS DYNAMICAL FORCING WITH AN 850MB MOISTURE TRANSPORT PLUME AND LINGERING INSTABILITY MEANS WE SHOULD BE ABLE TO KEEP SOME SHOWERS AND THUNDERSTORMS GOING THROUGH THE EVENING. UNTIL INSTABILITY WANES...EXPECT A SEVERE THREAT TO EXIST...JUST AS THE 06.12Z HIRES ARW/NMM SUGGEST. MUCH OF THE CONVECTION COULD BE EAST OF THE AREA BY THE OVERNIGHT HOURS...OR AT LEAST OVER THE SOUTHEAST HALF...SO PRECIPITATION DIMINISH NORTHWEST TO SOUTHEAST THROUGH THE NIGHT. PLUS...PRECIPITABLE WATER VALUES TANK AGAIN AFTER BRIEFLY COMING UP MONDAY AFTERNOON. ON TUESDAY...MODEL AGREEMENT IS GOOD ON SETTING UP AN UPPER LEVEL TROUGH FROM NORTHERN ONTARIO SOUTHWARD THROUGH THE WESTERN GREAT LAKES REGION. COOL AIR ALOFT COMBINED WITH A SHORTWAVE DROPPING THROUGH THIS TROUGH IN WISCONSIN...DAYTIME HEATING...AS WELL AS LINGERING LOW LEVEL MOISTURE COULD SPARK SOME DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS. BEST CHANCE FOR THIS WILL BE IN WISCONSIN WITH THE SHORTWAVE DROPPING THROUGH. DRIER WEATHER LOOKS TO PREVAIL TUESDAY NIGHT THROUGH THURSDAY WITH THE FORECAST AREA. THIS IS A RESULT OF A DRIER WESTERN CANADIAN HIGH PRESSURE AREA MOVING THROUGH...AND BEING AROUND THE INFLECTION POINT BEHIND THE WESTERN GREAT LAKES UPPER TROUGH PUSHING OFF TO THE EAST. TEMPERATURES ARE LIKELY TO BE A BIT ON THE COOL SIDE WITH 850MB TEMP ANOMALIES ABOUT 1 STANDARD DEVIATION BELOW NORMAL...OR BETWEEN 9- 13C. LOW PRECIPITABLE WATER AROUND 0.75 INCHES WILL HELP TOO IN RADIATIVE COOLING AT NIGHT...ALONG WITH MIXING OF DEWPOINTS IN THE DAY. COULD SEE SOME VALLEY FOG TUESDAY AND WEDNESDAY NIGHTS. FOR THURSDAY NIGHT INTO THE WEEKEND. WARM ADVECTION BEGINS IN EARNEST THURSDAY NIGHT AS THE HIGH HEADS OFF TO THE EAST. MODEL CONSENSUS IS FOR NUMEROUS SHOWERS AND THUNDERSTORMS TO INITIATE WITH THE MOISTURE RETURN FROM THE UPPER MIDWEST SOUTHWARD INTO THE CENTRAL PLAINS...PERHAPS CREEPING INTO THE FORECAST AREA EITHER LATE THURSDAY NIGHT OR DURING THE DAY FRIDAY. STORM CHANCES THEN LOOK TO CONTINUE THROUGH SATURDAY AS AN UPPER TROUGH DROPS SOUTH FROM MANITOBA INTO THE WESTERN GREAT LAKES REGION. PERHAPS BY SUNDAY ALL THE CONVECTIVE POTENTIAL WILL GET SHOVED TO THE SOUTH AS THE UPPER TROUGH CONTINUES TO DIG SOUTHEASTWARD. HOWEVER...HAVE STILL MAINTAINED CHANCES OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA. TEMPERATURE WISE...850MB TEMPS GENERALLY RANGE 16-18C THROUGH SATURDAY...SUPPORTING HIGHS IN THE 80S. THESE SHOULD COOL BACK SOME ON SUNDAY WITH THE TROUGH DROPPING IN. HUMIDITY WILL BE UP TOO FRIDAY AND SATURDAY WITH THAT RETURN FLOW...EVAPOTRANSPORATION AND POTENTIAL CONVECTION ADDING MOISTURE TO THE BOUNDARY LAYER. && .AVIATION...(FOR THE 00Z TAFS...THROUGH 00Z MONDAY EVENING) ISSUED AT 550 PM CDT SUN JUL 6 2014 SHRA/TS HAVE FIRED ALONG AND AHEAD OF A FRONT/DRY LINE TRACKING EAST ACROSS EASTERN MN/IA EARLY THIS EVENING...AND SHOULD BE EAST OF KRST BY 00Z...BUT COULD LINGER FOR AN HOUR OR TWO NEAR KLSE PAST TAF ISSUANCE. SKIES WILL CLEAR BY MID EVENING...WITH VFR CONDITIONS THEN EXPECTED THROUGH MONDAY MORNING. ANOTHER UPPER LEVEL TROUGH/SFC FRONT COMBO WILL SLIDE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY MONDAY AFTERNOON/EVENING...TRIGGERING MORE SHRA/TS. THREAT TIME APPEARS TO BE IN THE 20-03Z TIME FRAME AT THE MOMENT. AMPLE ATMOSPHERIC SUPPORT FOR A STRONG-SEVERE STORM THREAT. && .HYDROLOGY... ISSUED AT 331 PM CDT SUN JUL 6 2014 RIVER STAGES ARE FALLING ALONG THE MISSISSIPPI RIVER AND IT APPEARS THAT ALL OF THEM WILL BE BELOW FLOOD STAGE BY THURSDAY. THERE IS SOME RAIN FORECAST OVER THE NEXT FEW DAYS...BUT NONE OF IT LOOKS WIDESPREAD HEAVY ENOUGH TO MAKE A SIGNIFICANT IMPACT ON THE MISSISSIPPI...OR EVEN TRIBUTARIES FOR THAT MATTER. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ MESOSCALE...AJ SHORT TERM..AJ LONG TERM...AJ AVIATION....RIECK HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
331 PM CDT SUN JUL 6 2014 .MESOSCALE DISCUSSION... ISSUED AT 331 PM CDT SUN JUL 6 2014 NUMEROUS SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP ALONG AND NORTH OF INTERSTATE 90...ESPECIALLY IN WISCONSIN. THESE ARE ON THE NOSE OF 850MB MOISTURE TRANSPORT AND BASICALLY THE FINE LINE BACK EDGE IS THE 850MB FRONT DEPICTED IN RAP ANALYSIS. THE STRONGEST CORE HAS BEEN OVER TREMPEALEAU COUNTY...AND DOES HAVE SOME MID- LEVEL ROTATION...HOWEVER MUCH OF THE CORE APPEARS TO BE RAIN. NOT ANTICIPATING ANY OF THIS ELEVATED DRIVEN CONVECTION TO TURN SEVERE. FARTHER TO THE WEST...STILL MONITORING FOR SHOWERS AND THUNDERSTORMS TO DEVELOP FROM NORTH CENTRAL IOWA TO SOUTH CENTRAL MN AND WEST CENTRAL WI. SEEING A TOWERING CUMULUS LINE ON VISIBILE IMAGERY...BUT OVERALL DEEP- MOISTURE AND EVEN SURFACE CONVERGENCE ALONG THIS TROUGH IS WEAK. LOOKING AT THE SURFACE FLOW...IT GOES SOUTHWEST AT RST TO NEARLY WEST AT I-35 TO NORTHWEST AT NEW ULM...A LONG DISTANCE. RAP ANALYSIS DOES SHOW 2500-3500 J/KG OF MLCAPE WITH LITTLE CIN IN THIS CORRIDOR...THOUGH. THUS...A WAIT AND SEE IF ANYTHING CAN POP. SHOULD A STORM FIRE...IT WILL PROBABLY TURN SEVERE QUICKLY. NEEDLESS TO SAY...THE COMBINATION OF THE LONG PERIOD OF HAVING THE STRATUS AROUND TODAY AND NOT A LOT OF CONVERGENCE ON THE FRONT HAVE BEEN DETRIMENTAL TO SEVERE POTENTIAL. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 201 PM CDT SUN JUL 6 2014 MAIN SHORT TERM CONCERNS ARE ON CONVECTIVE EVOLUTION AND SEVERE POTENTIAL FOR THIS AFTERNOON/EVENING AND AGAIN LATE MONDAY. CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED STRONG RIDGING OVER THE WESTERN U.S. WHILE GENERAL WEAK TROUGHING PRESIDED OVER THE GREAT LAKES. A WEAK SHORTWAVE WAS EVIDENT OVER CENTRAL MN. ACCOMPANYING THIS SHORTWAVE PER THE RAP AT 800MB WERE 30 KT NORTHWEST WINDS AND 14-15C TEMPERATURES. COMPARE THIS TO 25-30 KT SOUTHWEST WINDS AND 18-20C TEMPERATURES OVER THE FORECAST AREA. THAT WARM NOSE COMBINED WITH MORNING STRATUS AND DEBRIS CLOUDS HAS KEPT CONDITIONS CAPPED THUS FAR. EDGE OF CAP REFLECTED NICELY TOO BY SOME ELEVATED SHOWERS AND THUNDERSTORMS GOING ON OVER WEST-CENTRAL WISCONSIN. TEMPERATURES FOR THE MOST PART HAVE BEEN STUCK IN THE 70S WITH A FEW 80S WHERE CLEARING BRIEFLY OCCURRED IN SOUTHEAST MN AND WEST CENTRAL WI. DEWPOINTS HAVE BEEN ON THE RISE...THOUGH...NOW IN THE LOW 70S. BACK IN WESTERN IA... EVAPOTRANSPORATION PUSHING DEWPOINTS THERE IN THE UPPER 70S. THINKING THESE HIGHER DEWPOINTS ADVECTING TOWARDS THE AREA IS NOT HELPING MATTERS TO CLEAR THE STRATUS. THE AFOREMENTIONED TEMPERATURES AND DEWPOINTS HAVE RESULTED IN MLCAPE VALUES OF 1500- 2010 J/KG WHILE MLCIN SITS 50-100 J/KG WHERE IT CLEARED TO 201-300 J/KG WHERE ITS STILL CLOUDY. MEANWHILE...IN SOUTHWEST MN... DEWPOINTS HAVE FALLEN OFF INTO MID LOW 50S BEHIND A TROUGH/DRYLINE THAT STRETCHES FROM NORTHWEST IOWA INTO NORTHWEST WI. ANTICIPATING CONVECTION TO FIRE IN THE NEXT 1-2 HOURS ALONG THE TROUGH/DRYLINE NEAR/WEST OF THE FORECAST AREA AS DAYTIME HEATING CONTINUES TO GET RID OF THE CIN. CONVECTION SHOULD TAKE ON A SCATTERED NATURE GIVEN THE CAP IN PLACE. WHERE CONVECTION DOES FIRE...0-3KM AND 0-6KM SHEAR ARE ON THE ORDER OF 20-25KT... WHICH SHOULD FAVOR MORE MULTI-CELLULAR ACTIVITY. GIVEN THE AMOUNT OF CAPE...CANNOT RULE OUT AN INITIAL SUPERCELL...BUT THINKING MORE INTENSE MULTI-CELLS ARE MORE LIKELY. LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN CONCERNS. GENERAL MODEL CONSENSUS OF BOTH DETERMINISTIC AND HIGH RESOLUTION MODELS SUGGEST MUCH OF THE CONVECTION SHOULD BE SOUTHEAST OF THE FORECAST AREA BY 01-02Z. HOWEVER...THERE IS POTENTIAL THAT THE CONVECTION DOESNT EVEN MAKE IT INTO THE SOUTHEAST END OF THE FORECAST AREA BECAUSE OF THE MASSIVE AMOUNT OF CIN RIGHT NOW IN PLACE. MANY HRRR RUNS TODAY HAVE SHOWN THIS. MUCH OF TONIGHT AND INTO MONDAY MORNING THEN LOOKS DRY AS UNIDIRECTIONAL NORTHWEST FLOW FROM THE SURFACE TO 500MB BRINGS IN SOMEWHAT COOLER AND DRIER AIR IN FROM NORTH DAKOTA. THIS IS REFLECTED WELL IN GOES PRECIPITABLE WATER IMAGERY WHICH SHOWS VALUES OF 1 INCH OR LESS OVER WESTERN MN COMPARED TO 1.5-1.75 INCHES OVER THE FORECAST AREA. HEADING INTO MONDAY AFTERNOON...A LONG WAVE SHORTWAVE TROUGH IS PROGGED TO DROP INTO THE EASTERN DAKOTAS AND WESTERN MN. INCREASING 850MB MOISTURE TRANSPORT AHEAD OF THE TROUGH...COMBINED WITH 1000- 1500 J/KG OF MLCAPE WITH LITTLE CAPPING AND A SURFACE TROUGH MOVING THROUGH...SHOULD RESULT IN A DECENT AMOUNT OF CONVECTION ACROSS MINNESOTA IN THE AFTERNOON HOURS...AS DEPICTED TOO BY DETERMINISTIC AND HIGH RESOLUTION GUIDANCE. THIS CONVECTION COULD SPREAD INTO THE NORTHWEST HALF OF THE FORECAST AREA BY LATE IN THE DAY. GIVEN 0-3KM SHEAR VALUES OF 25-35 KT AND MORE IMPORTANTLY 0-6KM SHEAR VALUES OF 40-55 KT...ORGANIZED SEVERE CONVECTION STILL APPEARS POSSIBLE. COULD END UP SEEING A MIX OF SUPERCELL AND LINE SEGMENTS...THOUGH THE SHEAR BEING UNIDIRECTIONAL MAY FAVOR MORE LINE SEGMENTS AND THUS DAMAGING WINDS. NEED TO WATCH THE LARGE HAIL CONCERN INITIALLY TOO GIVEN LOWER FREEZING LEVELS...DROPPING FROM NEAR 14000 FT THIS AFTERNOON TO 12010 FT LATE MONDAY. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 201 PM CDT SUN JUL 6 2014 MAIN HIGHLIGHTS FOR THE LONG TERM PERIOD ARE SEVERE POTENTIAL MONDAY EVENING FOLLOWED BY COOLER WEATHER FOR MID-WEEK. MONDAY NIGHT...BOTH THE LONG WAVE SHORTWAVE TROUGH AT 500MB AND THE ASSOCIATED SURFACE TROUGH ARE PROGGED TO MOVE SOUTHEAST THROUGH THE REGION. THERE ALSO APPEARS TO BE A POINT IN THE EVENING WHERE WE GET INTO A LEFT EXIT REGION OF AN UPPER JET STREAK. COMBINE THIS DYNAMICAL FORCING WITH AN 850MB MOISTURE TRANSPORT PLUME AND LINGERING INSTABILITY MEANS WE SHOULD BE ABLE TO KEEP SOME SHOWERS AND THUNDERSTORMS GOING THROUGH THE EVENING. UNTIL INSTABILITY WANES...EXPECT A SEVERE THREAT TO EXIST...JUST AS THE 06.12Z HIRES ARW/NMM SUGGEST. MUCH OF THE CONVECTION COULD BE EAST OF THE AREA BY THE OVERNIGHT HOURS...OR AT LEAST OVER THE SOUTHEAST HALF...SO PRECIPITATION DIMINISH NORTHWEST TO SOUTHEAST THROUGH THE NIGHT. PLUS...PRECIPITABLE WATER VALUES TANK AGAIN AFTER BRIEFLY COMING UP MONDAY AFTERNOON. ON TUESDAY...MODEL AGREEMENT IS GOOD ON SETTING UP AN UPPER LEVEL TROUGH FROM NORTHERN ONTARIO SOUTHWARD THROUGH THE WESTERN GREAT LAKES REGION. COOL AIR ALOFT COMBINED WITH A SHORTWAVE DROPPING THROUGH THIS TROUGH IN WISCONSIN...DAYTIME HEATING...AS WELL AS LINGERING LOW LEVEL MOISTURE COULD SPARK SOME DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS. BEST CHANCE FOR THIS WILL BE IN WISCONSIN WITH THE SHORTWAVE DROPPING THROUGH. DRIER WEATHER LOOKS TO PREVAIL TUESDAY NIGHT THROUGH THURSDAY WITH THE FORECAST AREA. THIS IS A RESULT OF A DRIER WESTERN CANADIAN HIGH PRESSURE AREA MOVING THROUGH...AND BEING AROUND THE INFLECTION POINT BEHIND THE WESTERN GREAT LAKES UPPER TROUGH PUSHING OFF TO THE EAST. TEMPERATURES ARE LIKELY TO BE A BIT ON THE COOL SIDE WITH 850MB TEMP ANOMALIES ABOUT 1 STANDARD DEVIATION BELOW NORMAL...OR BETWEEN 9- 13C. LOW PRECIPITABLE WATER AROUND 0.75 INCHES WILL HELP TOO IN RADIATIVE COOLING AT NIGHT...ALONG WITH MIXING OF DEWPOINTS IN THE DAY. COULD SEE SOME VALLEY FOG TUESDAY AND WEDNESDAY NIGHTS. FOR THURSDAY NIGHT INTO THE WEEKEND. WARM ADVECTION BEGINS IN EARNEST THURSDAY NIGHT AS THE HIGH HEADS OFF TO THE EAST. MODEL CONSENSUS IS FOR NUMEROUS SHOWERS AND THUNDERSTORMS TO INITIATE WITH THE MOISTURE RETURN FROM THE UPPER MIDWEST SOUTHWARD INTO THE CENTRAL PLAINS...PERHAPS CREEPING INTO THE FORECAST AREA EITHER LATE THURSDAY NIGHT OR DURING THE DAY FRIDAY. STORM CHANCES THEN LOOK TO CONTINUE THROUGH SATURDAY AS AN UPPER TROUGH DROPS SOUTH FROM MANITOBA INTO THE WESTERN GREAT LAKES REGION. PERHAPS BY SUNDAY ALL THE CONVECTIVE POTENTIAL WILL GET SHOVED TO THE SOUTH AS THE UPPER TROUGH CONTINUES TO DIG SOUTHEASTWARD. HOWEVER...HAVE STILL MAINTAINED CHANCES OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA. TEMPERATURE WISE...850MB TEMPS GENERALLY RANGE 16-18C THROUGH SATURDAY...SUPPORTING HIGHS IN THE 80S. THESE SHOULD COOL BACK SOME ON SUNDAY WITH THE TROUGH DROPPING IN. HUMIDITY WILL BE UP TOO FRIDAY AND SATURDAY WITH THAT RETURN FLOW...EVAPOTRANSPORATION AND POTENTIAL CONVECTION ADDING MOISTURE TO THE BOUNDARY LAYER. && .AVIATION...(FOR THE 18Z TAFS...THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1220 PM CDT SUN JUL 6 2014 MVFR/IFR STRATUS DECK FINALLY BREAKING/SCATTERING AS OF MID DAY. WITH DIURNAL WARMING AND SOUTHWEST 10-20KT WINDS FOR MIXING...EXPECT THIS TO CONTINUE THRU THE AFTERNOON WITH RISING CLOUD HGTS. A FRONTAL BOUNDARY FROM NEAR KDLH TO KFSD WILL MOVE RATHER QUICKLY SOUTHEAST AND ACROSS THE TAF SITES THIS AFTERNOON/EARLY THIS EVENING. FRONT WILL TRIGGER A SCT-BKN LINE OF SHRA/TSRA AS IT MOVES ACROSS...MAINLY IN THE 20-22Z PERIOD AT KRST AND 22-24Z AT KLSE. MAIN CONVECTION STILL LOOKS TO DEVELOP JUST EAST OF KRST SO LEFT THAT AS PERIOD OF VCTS. CONTINUED WITH 2SM TSRA AT KLSE...BUT IF TSRA END UP MORE SCATTERED IN THE LINE...VCTS MAY BE MORE APPROPRIATE FOR THIS PERIOD AT KLSE. ONCE FRONT GOES THRU...DEW POINTS DROP ABOUT 10F AS DRIER AIR SPREADS IN. WEST-NORTHWEST WINDS OF 5-10KTS THEN KEEP THE BOUNDARY LAYER STIRRED TONIGHT...AND ANY LATE NIGHT/EARLY MORNING BR TO A MINIMUM. GOOD VFR CONDITIONS EXPECTED TONIGHT THRU MON MORNING. ANOTHER ROUND OF SHRA/TSRA WITH MVFR/IFR CIGS/VSBYS IS SLATED TO SPREAD INTO THE TAF SITES LATER MON AFTERNOON/EVENING. && .HYDROLOGY... ISSUED AT 331 PM CDT SUN JUL 6 2014 RIVER STAGES ARE FALLING ALONG THE MISSISSIPPI RIVER AND IT APPEARS THAT ALL OF THEM WILL BE BELOW FLOOD STAGE BY THURSDAY. THERE IS SOME RAIN FORECAST OVER THE NEXT FEW DAYS...BUT NONE OF IT LOOKS WIDESPREAD HEAVY ENOUGH TO MAKE A SIGNIFICANT IMPACT ON THE MISSISSIPPI...OR EVEN TRIBUTARITES FOR THAT MATTER. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ MESOSCALE...AJ SHORT TERM...AJ LONG TERM...AJ AVIATION.....DAS HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
201 PM CDT SUN JUL 6 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 201 PM CDT SUN JUL 6 2014 MAIN SHORT TERM CONCERNS ARE ON CONVECTIVE EVOLUTION AND SEVERE POTENTIAL FOR THIS AFTERNOON/EVENING AND AGAIN LATE MONDAY. CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED STRONG RIDGING OVER THE WESTERN U.S. WHILE GENERAL WEAK TROUGHING PRESIDED OVER THE GREAT LAKES. A WEAK SHORTWAVE WAS EVIDENT OVER CENTRAL MN. ACCOMPANYING THIS SHORTWAVE PER THE RAP AT 800MB WERE 30 KT NORTHWEST WINDS AND 14-15C TEMPERATURES. COMPARE THIS TO 25-30 KT SOUTHWEST WINDS AND 18-20C TEMPERATURES OVER THE FORECAST AREA. THAT WARM NOSE COMBINED WITH MORNING STRATUS AND DEBRIS CLOUDS HAS KEPT CONDITIONS CAPPED THUS FAR. EDGE OF CAP REFLECTED NICELY TOO BY SOME ELEVATED SHOWERS AND THUNDERSTORMS GOING ON OVER WEST-CENTRAL WISCONSIN. TEMPERATURES FOR THE MOST PART HAVE BEEN STUCK IN THE 70S WITH A FEW 80S WHERE CLEARING BRIEFLY OCCURRED IN SOUTHEAST MN AND WEST CENTRAL WI. DEWPOINTS HAVE BEEN ON THE RISE...THOUGH...NOW IN THE LOW 70S. BACK IN WESTERN IA... EVAPOTRANSPORATION PUSHING DEWPOINTS THERE IN THE UPPER 70S. THINKING THESE HIGHER DEWPOINTS ADVECTING TOWARDS THE AREA IS NOT HELPING MATTERS TO CLEAR THE STRATUS. THE AFOREMENTIONED TEMPERATURES AND DEWPOINTS HAVE RESULTED IN MLCAPE VALUES OF 1500- 2010 J/KG WHILE MLCIN SITS 50-100 J/KG WHERE IT CLEARED TO 201-300 J/KG WHERE ITS STILL CLOUDY. MEANWHILE...IN SOUTHWEST MN... DEWPOINTS HAVE FALLEN OFF INTO MID LOW 50S BEHIND A TROUGH/DRYLINE THAT STRETCHES FROM NORTHWEST IOWA INTO NORTHWEST WI. ANTICIPATING CONVECTION TO FIRE IN THE NEXT 1-2 HOURS ALONG THE TROUGH/DRYLINE NEAR/WEST OF THE FORECAST AREA AS DAYTIME HEATING CONTINUES TO GET RID OF THE CIN. CONVECTION SHOULD TAKE ON A SCATTERED NATURE GIVEN THE CAP IN PLACE. WHERE CONVECTION DOES FIRE...0-3KM AND 0-6KM SHEAR ARE ON THE ORDER OF 20-25KT... WHICH SHOULD FAVOR MORE MULTI-CELLULAR ACTIVITY. GIVEN THE AMOUNT OF CAPE...CANNOT RULE OUT AN INITIAL SUPERCELL...BUT THINKING MORE INTENSE MULTI-CELLS ARE MORE LIKELY. LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN CONCERNS. GENERAL MODEL CONSENSUS OF BOTH DETERMINISTIC AND HIGH RESOLUTION MODELS SUGGEST MUCH OF THE CONVECTION SHOULD BE SOUTHEAST OF THE FORECAST AREA BY 01-02Z. HOWEVER...THERE IS POTENTIAL THAT THE CONVECTION DOESNT EVEN MAKE IT INTO THE SOUTHEAST END OF THE FORECAST AREA BECAUSE OF THE MASSIVE AMOUNT OF CIN RIGHT NOW IN PLACE. MANY HRRR RUNS TODAY HAVE SHOWN THIS. MUCH OF TONIGHT AND INTO MONDAY MORNING THEN LOOKS DRY AS UNIDIRECTIONAL NORTHWEST FLOW FROM THE SURFACE TO 500MB BRINGS IN SOMEWHAT COOLER AND DRIER AIR IN FROM NORTH DAKOTA. THIS IS REFLECTED WELL IN GOES PRECIPITABLE WATER IMAGERY WHICH SHOWS VALUES OF 1 INCH OR LESS OVER WESTERN MN COMPARED TO 1.5-1.75 INCHES OVER THE FORECAST AREA. HEADING INTO MONDAY AFTERNOON...A LONG WAVE SHORTWAVE TROUGH IS PROGGED TO DROP INTO THE EASTERN DAKOTAS AND WESTERN MN. INCREASING 850MB MOISTURE TRANSPORT AHEAD OF THE TROUGH...COMBINED WITH 1000- 1500 J/KG OF MLCAPE WITH LITTLE CAPPING AND A SURFACE TROUGH MOVING THROUGH...SHOULD RESULT IN A DECENT AMOUNT OF CONVECTION ACROSS MINNESOTA IN THE AFTERNOON HOURS...AS DEPICTED TOO BY DETERMINISTIC AND HIGH RESOLUTION GUIDANCE. THIS CONVECTION COULD SPREAD INTO THE NORTHWEST HALF OF THE FORECAST AREA BY LATE IN THE DAY. GIVEN 0-3KM SHEAR VALUES OF 25-35 KT AND MORE IMPORTANTLY 0-6KM SHEAR VALUES OF 40-55 KT...ORGANIZED SEVERE CONVECTION STILL APPEARS POSSIBLE. COULD END UP SEEING A MIX OF SUPERCELL AND LINE SEGMENTS...THOUGH THE SHEAR BEING UNIDIRECTIONAL MAY FAVOR MORE LINE SEGMENTS AND THUS DAMAGING WINDS. NEED TO WATCH THE LARGE HAIL CONCERN INITIALLY TOO GIVEN LOWER FREEZING LEVELS...DROPPING FROM NEAR 14000 FT THIS AFTERNOON TO 12010 FT LATE MONDAY. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 201 PM CDT SUN JUL 6 2014 MAIN HIGHLIGHTS FOR THE LONG TERM PERIOD ARE SEVERE POTENTIAL MONDAY EVENING FOLLOWED BY COOLER WEATHER FOR MID-WEEK. MONDAY NIGHT...BOTH THE LONG WAVE SHORTWAVE TROUGH AT 500MB AND THE ASSOCIATED SURFACE TROUGH ARE PROGGED TO MOVE SOUTHEAST THROUGH THE REGION. THERE ALSO APPEARS TO BE A POINT IN THE EVENING WHERE WE GET INTO A LEFT EXIT REGION OF AN UPPER JET STREAK. COMBINE THIS DYNAMICAL FORCING WITH AN 850MB MOISTURE TRANSPORT PLUME AND LINGERING INSTABILITY MEANS WE SHOULD BE ABLE TO KEEP SOME SHOWERS AND THUNDERSTORMS GOING THROUGH THE EVENING. UNTIL INSTABILITY WANES...EXPECT A SEVERE THREAT TO EXIST...JUST AS THE 06.12Z HIRES ARW/NMM SUGGEST. MUCH OF THE CONVECTION COULD BE EAST OF THE AREA BY THE OVERNIGHT HOURS...OR AT LEAST OVER THE SOUTHEAST HALF...SO PRECIPITATION DIMINISH NORTHWEST TO SOUTHEAST THROUGH THE NIGHT. PLUS...PRECIPITABLE WATER VALUES TANK AGAIN AFTER BRIEFLY COMING UP MONDAY AFTERNOON. ON TUESDAY...MODEL AGREEMENT IS GOOD ON SETTING UP AN UPPER LEVEL TROUGH FROM NORTHERN ONTARIO SOUTHWARD THROUGH THE WESTERN GREAT LAKES REGION. COOL AIR ALOFT COMBINED WITH A SHORTWAVE DROPPING THROUGH THIS TROUGH IN WISCONSIN...DAYTIME HEATING...AS WELL AS LINGERING LOW LEVEL MOISTURE COULD SPARK SOME DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS. BEST CHANCE FOR THIS WILL BE IN WISCONSIN WITH THE SHORTWAVE DROPPING THROUGH. DRIER WEATHER LOOKS TO PREVAIL TUESDAY NIGHT THROUGH THURSDAY WITH THE FORECAST AREA. THIS IS A RESULT OF A DRIER WESTERN CANADIAN HIGH PRESSURE AREA MOVING THROUGH...AND BEING AROUND THE INFLECTION POINT BEHIND THE WESTERN GREAT LAKES UPPER TROUGH PUSHING OFF TO THE EAST. TEMPERATURES ARE LIKELY TO BE A BIT ON THE COOL SIDE WITH 850MB TEMP ANOMALIES ABOUT 1 STANDARD DEVIATION BELOW NORMAL...OR BETWEEN 9- 13C. LOW PRECIPITABLE WATER AROUND 0.75 INCHES WILL HELP TOO IN RADIATIVE COOLING AT NIGHT...ALONG WITH MIXING OF DEWPOINTS IN THE DAY. COULD SEE SOME VALLEY FOG TUESDAY AND WEDNESDAY NIGHTS. FOR THURSDAY NIGHT INTO THE WEEKEND. WARM ADVECTION BEGINS IN EARNEST THURSDAY NIGHT AS THE HIGH HEADS OFF TO THE EAST. MODEL CONSENSUS IS FOR NUMEROUS SHOWERS AND THUNDERSTORMS TO INITIATE WITH THE MOISTURE RETURN FROM THE UPPER MIDWEST SOUTHWARD INTO THE CENTRAL PLAINS...PERHAPS CREEPING INTO THE FORECAST AREA EITHER LATE THURSDAY NIGHT OR DURING THE DAY FRIDAY. STORM CHANCES THEN LOOK TO CONTINUE THROUGH SATURDAY AS AN UPPER TROUGH DROPS SOUTH FROM MANITOBA INTO THE WESTERN GREAT LAKES REGION. PERHAPS BY SUNDAY ALL THE CONVECTIVE POTENTIAL WILL GET SHOVED TO THE SOUTH AS THE UPPER TROUGH CONTINUES TO DIG SOUTHEASTWARD. HOWEVER...HAVE STILL MAINTAINED CHANCES OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA. TEMPERATURE WISE...850MB TEMPS GENERALLY RANGE 16-18C THROUGH SATURDAY...SUPPORTING HIGHS IN THE 80S. THESE SHOULD COOL BACK SOME ON SUNDAY WITH THE TROUGH DROPPING IN. HUMIDITY WILL BE UP TOO FRIDAY AND SATURDAY WITH THAT RETURN FLOW...EVAPOTRANSPORATION AND POTENTIAL CONVECTION ADDING MOISTURE TO THE BOUNDARY LAYER. && .AVIATION...(FOR THE 18Z TAFS...THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1220 PM CDT SUN JUL 6 2014 MVFR/IFR STRATUS DECK FINALLY BREAKING/SCATTERING AS OF MID DAY. WITH DIURNAL WARMING AND SOUTHWEST 10-20KT WINDS FOR MIXING...EXPECT THIS TO CONTINUE THRU THE AFTERNOON WITH RISING CLOUD HGTS. A FRONTAL BOUNDARY FROM NEAR KDLH TO KFSD WILL MOVE RATHER QUICKLY SOUTHEAST AND ACROSS THE TAF SITES THIS AFTERNOON/EARLY THIS EVENING. FRONT WILL TRIGGER A SCT-BKN LINE OF SHRA/TSRA AS IT MOVES ACROSS...MAINLY IN THE 20-22Z PERIOD AT KRST AND 22-24Z AT KLSE. MAIN CONVECTION STILL LOOKS TO DEVELOP JUST EAST OF KRST SO LEFT THAT AS PERIOD OF VCTS. CONTINUED WITH 2SM TSRA AT KLSE...BUT IF TSRA END UP MORE SCATTERED IN THE LINE...VCTS MAY BE MORE APPROPRIATE FOR THIS PERIOD AT KLSE. ONCE FRONT GOES THRU...DEW POINTS DROP ABOUT 10F AS DRIER AIR SPREADS IN. WEST-NORTHWEST WINDS OF 5-10KTS THEN KEEP THE BOUNDARY LAYER STIRRED TONIGHT...AND ANY LATE NIGHT/EARLY MORNING BR TO A MINIMUM. GOOD VFR CONDITIONS EXPECTED TONIGHT THRU MON MORNING. ANOTHER ROUND OF SHRA/TSRA WITH MVFR/IFR CIGS/VSBYS IS SLATED TO SPREAD INTO THE TAF SITES LATER MON AFTERNOON/EVENING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION.....DAS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1033 AM CDT SUN JUL 6 2014 .UPDATE...CONSIDERABLE DEBRIS CLOUDINESS UPSTREAM ALONG WITH LOW LEVEL STRATUS FIELD WHICH HAS LEAD TO THE SHAKING OF CONFIDENCE FOR HOW STORMS WILL EVOLVE LATER. THE PLAN IS IT IS TILL EARLY AND THIS TIME OF YEAR THIS LOWER STRATUS SHOULD BURN OFF BURN OFF TO ALLOW FOR THE BUILDUP OF CAPE. MORE SUN ACRS SE WI BUT INITIATION POINT IS EXPECTED FURTHER WEST IN WC WI WHERE THE CLOUD COVER IS. CONCERN ATTM IS THAT WE ARE NOT SEEING ANY DECREASE IN CLOUD COVER EVOLVE. MID LEVEL JET STREAK STILL EXPECTED TO ENCROACH ON THE AREA THIS AFTERNOON WITH TIGHTENING 500 MILLIBAR HEIGHT GRADIENT. WITHIN THIS IS A WEAK SHORTWAVE THAT WILL AID IN VERTICAL MOTION. UPPER JET FURTHER NORTH HOWEVER SOME DIFFLUENCE NOTED ACRS CNTRL/SRN WI MODEL PROGGD DIVERGENCE IN RESPONSE TO THIS. SPC SUGGESTS THIS CLOUDINESS MAY RESULT IN CONVECTION BEING TIED TO THE FRONTAL ZONE BUT MODULATED BY HOW QUICK THESE CLOUDS AHEAD OF IT CAN THIN. 00Z NMM/ARW ARE STILL RATHER ROBUST BUT DO NOT BELIEVE THESE MODELS FROM LAST NIGHT HAVE A HANDLE ON THESE LOW CLOUDS. MEANWHILE THE 13Z HRRR SHOWING SOME STRONGER STORMS BUT NOT NEARLY AS WHAT THE OTHER 00Z MODELS WERE SHOWING. 12Z NAM SHOWS QPF BULLSEYE ACRS ERN CWA BETWEEN 18-00Z...SO FRONT COULD END UP INITIATING CONVECTION INTO A MORE UNSTABLE AIRMASS ACROSS OUR CWA WHERE SOME SUN IS HEATING THINGS UP. SO LOTS OF UNCERTAINTY AT THE MOMENT WITH THE THERMODYNAMICS BEING THE MAIN QUESTION MARK. DYNAMICALLY/FORCING WISE...ALL SYSTEMS ARE STILL GO. PC && .AVIATION/18Z TAFS/...PLENTY OF STRATUS ACRS NW 1/2 OF THE CWA THOUGH EXPECTING SOME BURNOFF AS THE HEATING OF THE DAY INCREASES. MAIN CHALLENGE CENTERS ON CONVECTIVE DEVELOPMENT WITH ALL OF THE UPSTREAM CLOUDINESS HINDERING THE CAPE BUILDUP ATTM. HOWEVER STILL EXPECT SOME THINNING AND SUBSEQUENT DESTABILIZATION TO MAINTAIN A THREAT OF SOME STRONGER OR SEVERE STORMS LATER THIS AFTERNOON INTO THE EVENING HOURS AS MID LEVEL STREAK/SHORTWAVE AND SURFACE COLD FRONT APPROACH THE AREA. BUT THERE IS UNCERTAINTY ATTM. ANY STORMS EXPECTED TO BE SOUTHEAST OF THE AREA BY 6Z WITH WEAK RIDGING TAKING HOLD FOR MUCH OF MONDAY. PC && .PREV DISCUSSION... /ISSUED 348 AM CDT SUN JUL 6 2014/ TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM. AREA OF LOW STRATUS CLOUDS OVER MOST OF THE AREA SHOULD LINGER INTO THE MORNING HOURS...BEFORE DAYTIME HEATING MIXES THIS LAYER OUT. SYNOPTIC AND MESOSCALE MODELS SHOWING COLD FRONT MOVING EASTWARD ACROSS THE AREA LATER THIS AFTERNOON THROUGH THE LATE EVENING HOURS. A 500 MB VORTICITY MAXIMUM ACCOMPANIES THE FRONT. THE FRONT MOVES INTO THE FAR WESTERN COUNTIES DURING PEAK HEATING. WARM AND HUMID CONDITIONS ARE EXPECTED...WITH MID 80S F FOR HIGHS...AND DEW POINTS AROUND 70 F. MEAN LAYER CAPES OF 2000 TO 2500 J/KG ARE EXPECTED. 0 TO 6 KM SHEAR VALUES OF 20 TO 30 KNOTS ARE EXPECTED AS WELL...WITH PRECIPITABLE WATER VALUES OF AROUND 1.75 INCHES...2 STANDARD DEVIATIONS ABOVE NORMAL. AREA FORECAST SOUNDINGS DO SHOW A CAP TO BE OVERCOME...WHICH SHOULD OCCUR BETWEEN 21Z SUNDAY AND 00Z MONDAY. CONVECTION IS LIKELY TO OCCUR FROM WEST TO EAST WITH THE FRONT...BEGINNING AS DISCRETE CELLS BEFORE BECOMING MORE LINEAR IN NATURE. SPC HAS AREA IN SLIGHT RISK FOR SEVERE STORMS IN DAY 1 OUTLOOK LATER THIS AFTERNOON AND THIS EVENING. LARGE HAIL AND DAMAGING WINDS ARE CERTAINLY POSSIBLE. 0 TO 1 KM SHEAR VALUES OF 10 TO 20 KNOTS DOES SUPPORT AN ISOLATED TORNADO RISK AS WELL...WITH LOW LCLS EXPECTED. CONVECTION SHOULD DIMINISH BY 06Z MONDAY...ONCE UPWARD VERTICAL MOTION SHIFTS TO THE EAST. TEMPERATURES SHOULD ONLY FALL INTO THE UPPER 60S TO AROUND 70 FOR LOWS TONIGHT. MONDAY...FORECAST CONFIDENCE...MEDIUM ANOTHER ROUND OF STORMS EXPECTED MONDAY EVENING INTO THE NIGHT AS A SHORTWAVE PUSHES THROUGH. INCREASED POPS GIVEN DECENT WARM ADVECTION IN THE LOW AND MID LEVELS...ALONG WITH SOME UPPER LEVEL DIVERGENCE. LOOKS LIKE A BIT LESS OF A SEVERE CHANCE THAN TODAY DUE THE LATER TIMING AND LESS INSTABILITY...THOUGH 0-6 KM BULK SHEAR OF 40-50 KNOTS WILL PROBABLY KEEP THINGS INTERESTING. SPC DOES HAVE THE DAY 2 SLIGHT RISK INTO THE FAR WEST FORECAST AREA. TEMPS MONDAY ARE EXPECTED TO BE ON THE WARM SIDE AGAIN...WITH 925 MB TEMPS GENERALLY IN THE 22-24C RANGE. SHOULD SEE A GOOD AMOUNT OF SUN...SO WENT MID 80S MOST PLACES. TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM A COUPLE OF WEAK WAVES MAY BRING A FEW SHOWERS AND STORMS TUESDAY AND WEDNESDAY. THERE WILL BE MUCH LESS MOISTURE TO WORK WITH...AS PRECIPITABLE WATER VALUES WILL BE AROUND AN INCH TUE...AND EVEN LESS THAN THAT WED. FORCING IS ON THE WEAK SIDE TOO...SO KEPT POPS ON THE LOW END. THURSDAY THROUGH SATURDAY...FORECAST CONFIDENCE...MEDIUM INCREASING WARM ADVECTION FROM THE SOUTHWEST MAY KICK OF A FEW SHOWERS/STORMS LATER FRIDAY...BUT OTHERWISE IT LOOKS LIKE A DRY END TO THE WORK WEEK. SHOWER/STORM CHANCES ARE THEN EXPECTED TO INCREASE FRIDAY NIGHT INTO SATURDAY AS A SHORTWAVE MOVES THROUGH. SHOULD SEE HIGH TEMPS WITHIN A COUPLE DEGREES OF NORMAL THU-SAT. AVIATION/12Z TAFS/... MVFR CEILINGS WITH LOW STRATUS CLOUDS SHOULD LINGER INTO THE MORNING HOURS ACROSS MADISON...WITH THE EASTERN SITES IN AND OUT OF IT. THESE CLOUDS SHOULD DISSIPATE BY AROUND 18Z SUNDAY. SOUTH SOUTHWEST WINDS SHOULD BECOME GUSTY AT TIMES BY THE AFTERNOON...GUSTING TO AROUND 22 KNOTS BY LATER IN THE AFTERNOON. DIURNAL CUMULUS SHOULD DEVELOP AS WELL. COLD FRONT WITH THUNDERSTORMS SHOULD AFFECT MADISON BETWEEN 22Z SUNDAY AND 02Z MONDAY...AND THE EASTERN SITES BETWEEN 00Z AND 04Z SUNDAY. STRONG GUSTY WINDS AND LARGE HAIL ARE POSSIBLE WITH ANY SEVERE STORMS...ALONG WITH VISIBILITIES DOWN TO ALTERNATE MINIMUMS. WINDS WEAKEN AND SHIFT TO THE WEST AFTER 06Z MONDAY...WITH CLOUDS GRADUALLY THINNING OUT FROM WEST TO EAST. MARINE... SMALL CRAFT ADVISORY CONTINUES FROM 18Z SUNDAY TO 03Z MONDAY ACROSS THE NEARSHORE WATERS. FREQUENT SOUTH SOUTHWEST WIND GUSTS TO 22 TO 25 KNOTS SHOULD OCCUR DURING THIS TIME...WITH GOOD MIXING OF THE LOW LEVEL WINDS. WAVES SHOULD BUILD TO 3 TO 4 FEET NEAR SHEBOYGAN...WITH 2 TO 4 FOOT WAVES TO THE SOUTH. WINDS AND WAVES WILL SUBSIDE TONIGHT AFTER COLD FRONT MOVES INTO THE AREA. BEACHES... A MODERATE SWIM RISK IS EXPECTED FOR SHEBOYGAN AND OZAUKEE COUNTY BEACHES ALONG LAKE MICHIGAN LATER THIS MORNING INTO EARLY THIS EVENING. THE WINDS WILL BE SOUTH TO SOUTH SOUTHWEST AND GUSTY...GENERATING WAVES OF UP TO 3 TO 4 FEET. THIS WILL POSE SOME RISK TO SWIMMERS IN THESE AREAS. WILL NOT ISSUE A BEACH HAZARDS STATEMENT AT THIS TIME. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM CDT THIS EVENING FOR LMZ643>646. && $$ TODAY/TONIGHT AND AVIATION/MARINE...WOOD MONDAY THROUGH SATURDAY...DDV
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
912 PM PDT MON JUL 7 2014 .UPDATE...REMOVED THUNDERSTORMS FROM THE FORECAST FOR THE REST OF TONIGHT. && .SYNOPSIS... HIGH PRESSURE ANCHORED OVER THE FOUR CORNERS REGION WILL KEEP ABOVE NORMAL TEMPERATURES ACROSS THE CENTRAL CALIFORNIA INTERIOR THROUGH MUCH OF THIS WEEK. AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE OVER THE SIERRA NEVADA THROUGH FRIDAY AS MONSOONAL MOISTURE CONTINUES OVER THE AREA. && .DISCUSSION... MONSOONAL MOISTURE BROUGHT PLENTY OF CLOUD COVER ACROSS THE CENTRAL SAN JOAQUIN VALLEY TODAY HELPING TO KEEP TEMPERATURES A FEW DEGREES COOLER. FRESNO REACHED A LATE HIGH OF 99 DEGREES... BREAKING THE 8 DAY STRING OF 100+ DEGREE DAYS. MOST VALLEY CITIES FROM HANFORD AND VISALIA NORTHWARD ALSO SAW HIGHS BELOW 100. HOWEVER...IN THE SOUTH VALLEY THERE WAS MUCH MORE SUNSHINE IT REMAINED HOT WITH BAKERSFIELD REACHING 105...MAKING IT 8 CONSECUTIVE DAYS OF 100+ THERE. AT THIS TIME IT DOES NOT APPEAR THAT WE WILL SEE AS MUCH CLOUD COVER MOVING OVER THE AREA TUESDAY. THIS WILL ALLOW TEMPERATURES TO WARM ABOVE 100 DEGREES IN MOST OF THE SAN JOAQUIN VALLEY ONCE AGAIN. ALTHOUGH A FEW LIGHT SHOWERS MAY STILL OCCUR OVER THE SIERRA TONIGHT...THUNDERSTORM ACTIVITY HAS REMAINED WELL TO OUR SOUTH AND EAST IN NEVADA. THUNDERSTORMS ARE NOT EXPECTED IN THE SIERRA FOR THE REMAINDER OF TONIGHT. WITH THE MONSOONAL MOISTURE STILL SURGING NORTHWARD...WITH LEAVE THE THREAT OF THUNDERSTORMS FOR TUESDAY BUT FEEL THE GREATER THREAT IS ONCE AGAIN TO OUR EAST WHERE THERE IS BETTER INSTABILITY. && .AVIATION... SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED OVER THE HIGH COUNTRY OF THE SOUTHERN SIERRA NEVADA FROM 20Z MON THRU 06Z TUE. LOCAL IFR CONDITIONS WILL BE POSSIBLE NEAR ANY THUNDERSTORMS THAT DEVELOP. OTHERWISE VFR CONDITIONS WILL PREVAIL OVER THE REGION DURING THE NEXT 24 HOURS. && .PREV DISC... /ISSUED 230 PM PDT MON JUL 7 2014/ ABUNDANT MONSOONAL MOISTURE CONTINUES TO STREAM NORTHWEST OVER THE REGION...BRINGING SIGNIFICANT CLOUD COVER...COOLER TEMPERATURES... VALLEY SHOWERS...AND SIERRA THUNDERSTORMS. LIGHT RAIN SHOWERS CONTINUE MAINLY NORTH OF VISALIA...WITH TRACE AMOUNTS AS FAR SOUTH AS HANFORD AND AS FAR NORTH AS ATWATER...VIA FACEBOOK AND TWITTER REPORTS. THE HRRR INDICATES THAT THESE SHOWERS WILL SHIFT NORTH INTO THE 00Z HOUR. WITH THE ADDITION OF SIGNIFICANT CLOUD COVER...DAYTIME HIGH TEMPERATURES GENERALLY FROM VISALIA NORTHWARD HAVE STRUGGLED TO WARM INTO THE 90S. THERE WERE TWO SEPARATE FORECAST UPDATES TO ACCOUNT FOR THE MUCH COOLER TEMPERATURES TODAY COMPARED TO YESTERDAY...WITH THE SECOND UPDATED LOWERING FORECAST HIGH TEMPERATURES TO JUST BELOW THE CENTURY MARK FOR THE REGION IMPACTED BY CLOUDS. SIERRA THUNDERSTORMS HAVE BEGUN TO DEVELOP NEAR THE TULARE/KERN COUNTY LINE. THESE THUNDERSTORMS ARE FORECAST TO BECOME MORE NUMEROUS INTO THE LATER AFTERNOON/EARLY EVENING HOURS AND SPREAD NORTH INTO NEAR YOSEMITE. THERE IS A SIGNIFICANT AMOUNT OF MOISTURE FOR THUNDERSTORM DEVELOPMENT...HOWEVER THERE IS LIMITED INSTABILITY. MU CAPE VALUES OVER THE CREST WILL STRUGGLE TO REACH 500 J/KG...SO AT BEST...ISOLATED THUNDERSTORMS CAN BE EXPECTED. MORE LIKELY THE REGION WILL SEE A DECENT AMOUNT OF RAIN OVER THE HIGHER ELEVATIONS. AS OF 1:30 PM...BLACKROCK IN TULARE CO HAD PICKED UP 0.09" IN THE PAST HOUR. OTHERWISE...UPPER LEVEL HIGH PRESSURE IS FORECAST TO DOMINATE THE FOUR CORNERS REGION THROUGH AT LEAST THE END OF THE WEEK...BRINGING TRIPLE DIGIT TEMPERATURES...ABOVE NORMAL FOR THE MIDDLE OF JULY. SIERRA THUNDERSTORMS WILL ALSO BE POSSIBLE THROUGH AT LEAST THE END OF THE WORK WEEK. THE MOISTURE SOURCE FOR THESE THUNDERSTORMS SHIFTS SLIGHTLY EAST THURSDAY INTO FRIDAY...RESULTING IN A LOW CONFIDENCE THUNDERSTORM FORECAST BOTH ON THURSDAY AND FRIDAY. && .AIR QUALITY ISSUES... ON TUESDAY JULY 8 2014... UNHEALTHY FOR SENSITIVE GROUPS IN FRESNO AND KERN COUNTIES AND SEQUOIA NATIONAL PARK AND FOREST. FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG && .CERTAINTY... THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM. THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM. CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL INFORMATION AND/OR TO PROVIDE FEEDBACK. && .CLIMATE... RECORDS SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR KFAT 07-07 111:1905 84:1891 76:1936 53:1903 KFAT 07-08 115:1905 84:1983 81:1896 51:1891 KFAT 07-09 113:1905 78:1936 81:2008 55:1983 KBFL 07-07 114:1905 85:1983 81:1968 46:1903 KBFL 07-08 114:1905 85:1983 79:1907 50:1899 KBFL 07-09 113:1905 83:1980 84:2008 52:1923 && .HNX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ PUBLIC...BEAN AVN/FW...DUDLEY PREV DISCUSSION...RILEY SYNOPSIS...ANDERSEN WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1126 PM MDT MON JUL 7 2014 .UPDATE... ISSUED AT 825 PM MDT MON JUL 7 2014 UPDATED TO INCREASE POPS ACROSS THE PALMER DIVIDE AND THE FAR SE PLAINS THIS EVENING AND OVERNIGHT. LATEST NAM IS PEGGING THE POTENTIAL FOR LOCALLY HEAVY RAINFALL ACROSS THE PIKES PEAK REGION AND LOWER EASTERN SLOPES OF THE WET MTS AND SOUTHERN SANGRE DE CRISTO MTS LATER TONIGHT...AS SFC-H7 WINDS BECOME WEAK EAST TO NORTHEAST BEHIND PASSING COLD FRONT SLIDING ACROSS NORTHEASTERN COLORADO AT THIS TIME. LATEST HIGHER RESOLUTION RAP AND HRRR ARE KEEPING SFC-H7 FLOW MORE NORTHERLY THROUGH THE OVERNIGHT AND WHICH WOULD TEND TO FAVOR THE RATON MESA REGION FOR LOCALLY HEAVY RAINFALL. WITH DEW PTS IN THE 50S TO LOWER 60S ACROSS NORTHEASTERN COLORADO...AND THE POTENTIAL FOR REDEVELOPING AND TRAINING OF STORMS ACROSS THE EASTERN MTS...THERE WILL BE AN INCREASED CONCERN FOR FLASH FLOODING ON AREA BURN SCARS THROUGH THE OVERNIGHT HOURS. UPDATE ISSUED AT 451 PM MDT MON JUL 7 2014 QUICK UPDATE TO SPREAD POPS FURTHER SOUTH ACROSS THE PLAINS WITH STORMS FIRING ON OUTFLOWS. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 239 PM MDT MON JUL 7 2014 SLIGHTLY MORE CONVECTION OCCURRING THIS AFTERNOON OVER THE AREA...AS AIR MASS HAS MOISTENED SOMEWHAT OVER THE PAST 24 HRS. SOUNDINGS STILL SUGGEST DRY LOW LEVELS AND RATHER HIGH CLOUD BASES...SO SUSPECT MOST STORMS AREN`T PRODUCING MUCH RAINFALL...EVEN OVER THE HIGHER TERRAIN. SURFACE COLD FRONT ALONG/JUST SOUTH OF THE PALMER DIVIDE SHOWS UP NICELY IN RADAR/SATELLITE IMAGERY AS OF 21Z...THOUGH COOLER AIR AND STRONGER PRESSURE GRADIENT ARE STILL FAIRLY FAR TO THE NORTH...WITH WON`T ARRIVE UNTIL LATER THIS EVENING. FOR THE REMAINDER OF THE AFTERNOON INTO THE EVENING...EXPECTED ISOLATED TO SCATTERED STORMS TO CONTINUE OVER THE MOUNTAINS AND HIGH VALLEYS WITH MOST ACTIVITY ENDING BY SUNSET. OVER THE I-25 CORRIDOR AND ACROSS THE EASTERN PLAINS...COLD FRONT WILL CONTINUE TO SINK SOUTH THROUGH THE EVENING...WITH GUSTY (30-40KT) NORTH WINDS ARRIVING AROUND SUNSET AT KCOS...AND SHORTLY THERE-AFTER ALONG THE LOWER ARKANSAS VALLEY. WITH CONVERGENCE ALONG THE FRONT AND SLIGHTLY DEEPER MOISTURE PUSHING WESTWARD ONCE THE BOUNDARY PASSES...SUSPECT AT LEAST ISOLATED TSRA WILL BE POSSIBLE THROUGH 06Z-09Z ALONG AND EAST OF THE MOUNTAINS. PORTIONS OF THE PLAINS WILL LIKELY SEE SOME LOWER CLOUDS AND A FEW SPRINKLES/LIGHT SHOWERS TOWARD SUNRISE AS DEEPER MOISTURE CONTINUES TO PUSH WESTWARD BEHIND THE FRONT. ON TUESDAY...MUCH COOLER CONDITIONS OVER THE EASTERN MOUNTAINS AND PLAINS WITH HIGH TEMPS AROUND 20F LOWER THAN MON. MOUNTAINS AND HIGH VALLEYS WILL COOL SLIGHTLY WITH MORE MOISTURE...THOUGH TEMPERATURE FALLS WILL BE LESS THAN THE DRAMATIC COOLING OVER THE PLAINS. AIR MASS OVER THE MOUNTAINS AND ALONG THE I-25 CORRIDOR WILL BE CONSIDERABLY MOISTER ON TUES...WITH SCT TO NUMEROUS TSRA LIKELY DEVELOPING BY EARLY AFTERNOON. DESPITE LACK OF ANY OBVIOUS UPPER SUPPORT....SUSPECT MODELS...ESPECIALLY NAM ARE UNDER ESTIMATING AMOUNT OF INSTABILITY OVER AREA AND WILL GO WITH HIGHER POPS THAN MODEL OUTPUT SUGGESTS. WILL HAVE TO WATCH AREA BURN SCARS AS STORMS WILL BE RATHER SLOW MOVING AND COULD PRODUCE HEAVY RAIN. MAIN QUESTION FOR THE DAY IS HOW FAR EAST WILL STORMS MOVE ON TO THE PLAINS...AS AIR MASS MAY TAKE A LONG TIME TO DESTABILIZE EAST OF I- 25. WILL KEEP AT LEAST ISOLATED POPS OVER ALL THE EASTERN PLAINS...AS LIFTED INDICES WILL EVENTUALLY DROP BELOW ZERO WITH AT LEAST A FEW HUNDRED JOULES OF CAPE AVAILABLE BY LATE AFTERNOON. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 239 PM MDT MON JUL 7 2014 MODELS CONTINUE TO BE IN AGREEMENT THROUGH THE EXTENDED PERIOD WITH HIGH PRESSURE OVER THE WEST AND A TROUGH OVER THE EASTERN STATES. ACTIVE WEATHER WILL PERSIST THROUGH THE EXTENDED PERIOD WITH GENERALLY DIURNALLY DRIVEN THUNDERSTORMS. EXPECT ONGOING SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE MOUNTAINS TUESDAY EVENING...SPREADING EAST ACROSS THE PLAINS THROUGH THE OVERNIGHT HOURS. LOCALLY HEAVY RAINFALL IS POSSIBLE...ESPECIALLY OVER THE EASTERN MOUNTAINS TUESDAY EVENING. BY WEDNESDAY...HIGH PRESSURE OVER THE GREAT BASIN WILL BUILD EASTWARD INTO THE ROCKIES. LOW LEVEL FLOW IS FORECAST TO TURN MORE SOUTHWESTERLY. MODELS ARE STILL TRYING TO DEVELOP A DRYLINE TYPE FEATURE ACROSS THE FAR EASTERN PLAINS WEDNESDAY AFTERNOON. THE GFS CONTINUES TO BE THE FURTHEST EAST...WITH CONVECTION FIRING OFF ACROSS WESTERN KANSAS. THE NAM KEEP THE MOISTURE FURTHER WEST ACROSS EASTERN COLORADO...WITH WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY WEDNESDAY AFTERNOON. SHEAR IS WEAK WITH THE HIGH PRESSURE OVERHEAD...AND IF THE MOISTURE STAYS IN PLACE...ONE OR TWO STRONG STORMS ARE POSSIBLE OVER THE PLAINS WEDNESDAY AFTERNOON TO EVENING. IT WILL ALL DEPEND IF AND WHERE THE DRYLINE SETS UP. EXPECT THUNDERSTORMS TO TRACK EAST OVERNIGHT AND CLEAR THE PLAINS BY THURSDAY MORNING. THE HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS COLORADO ON THURSDAY AND PERSIST THROUGH EARLY NEXT WEEK. THE MOUNTAIN AREAS OF SOUTHERN COLORADO WILL SEE DAILY AFTERNOON AND EVENING THUNDERSTORMS. ELSEWHERE...PRECIPITATION WILL DEPEND ON INDIVIDUAL DISTURBANCES MOVING NORTH OUT OF THE DESERT SOUTHWEST. MODELS SEEM TO BE IN GOOD AGREEMENT WITH DECENT WAVE MOVING NORTH SATURDAY INTO SUNDAY. BOTH DAYS WILL LIKELY SEE THE BEST POTENTIAL IN THE EXTENDED PERIOD OF SEEING WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY. MOISTURE WILL BE ADEQUATE FOR LOCALLY HEAVY RAINFALL ACROSS THE MOUNTAINS...WHICH COULD PRODUCE FLASH FLOODING ON AREA BURN SCARS. MOZLEY && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1126 PM MDT MON JUL 7 2014 COLD FRONT MOVING THROUGH PUB ATTM WILL CONTINUE TO DROP THROUGH THE SOUTHEAST PLAINS OVERNIGHT...WITH GUSTY NORTH TO NORTHEAST WINDS OF 20-30KTS AT COS AND PUB TO PERSIST THROUGH 10Z. SCATTERED SHOWERS AND THUNDSTORMS DEVELOPING BEHIND PASSING FRONT WITH BEST CHANCES OF SEEING WETTING RAIN AND MVFR CIGS AT COS THROUGH THE OVERNIGHT HOURS. MOIST UPSLOPE FLOW DEVELOPS AFT 12Z WITH MVFR CIGS DEVELOPING AT COS AND PUB AND PERSISTING THROUGH THE LATE MORNING. SCATTERED TO NUMEROUS TSRA OVER THE MOUNTAINS AFTER 18Z...POSSIBLY SPREADING OUT ACROSS A MORE STABLE ATMOSPHERE ACROSS THE I-25 CORRIDOR (COS AND PUB) AFT 20Z. MAINLY VFR CONDITIONS EXPECTED AT ALS THROUGH THE PERIOD...WITH BREEZY EASTERLY WINDS POSSIBLE AFT 10Z AS COLD FRONT BANKS UP ACROSS THE EASTERN MTS. SCATTTERED TSRA ACROSS THE MTS AFT 18Z BUT NOT ENOUGH CONFIDENCE FOR MORE THAN VCTS AT THE TERMINAL ATTM. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...PETERSEN LONG TERM...MOZLEY AVIATION...MW
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
215 AM CDT TUE JUL 8 2014 .DISCUSSION... 825 PM CDT A COLD FRONTAL BOUNDARY CONTINUES TO MOVE SOUTHEAST ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL IOWA WHILE A STATIONARY BOUNDARY IS STRETCHED FROM WEST TO EAST ACROSS THE FAR SOUTHERN CWA. WATER VAPOR SHOWS AN UPPER TROUGH SWINGING SOUTHEASTWARD INTO MINNESOTA WITH SEVERAL EMBEDDED WAVES HELPING TO KICK OFF CONVECTION...WITH ONE COMPLEX OVER WEST CENTRAL MINNESOTA AND ANOTHER ALONG THE IA/MO BORDER. THE CWA IS EXPECTED TO REMAIN BETWEEN THE TWO CURRENT AREAS OF CONVECTION BUT ADDITIONAL DEVELOPMENT IS EXPECTED JUST WEST OR OVER THE AREA LATER TONIGHT AS THE FRONT AND AN UPPER WAVE PASS. LATEST GUIDANCE SUGGESTS THAT THE MID LEVEL WAVE WILL AMPLIFY BRINGING AN ATTENDANT SPEED MAX ACROSS THE AREA INTO THE OVERNIGHT HOURS. ACTIVITY ALONG THE FRONT NEAR THE IA/MN BORDER HAS BEEN FESTERING BUT RAP ANALYSIS INDICATES THAT THERE IS STRONGER AXIS OF INSTABILITY ACROSS NORTHEAST IA THAT IS UNCAPPED SO SOME ENHANCEMENT IS POSSIBLE GOING FORWARD. EVENING DVN SOUNDING SHOWS A CAP IN PLACE WITH LOCAL AIRCRAFT SOUNDINGS SHOWING A MINIMAL CAP. WOULD THINK THIS CAP WOULD ERODE WITH THE INCREASE IN MID/UPPER ASCENT INTO THE OVERNIGHT. WITH MOISTURE FLUX AND PRIMARY LOW LEVEL JET WELL SOUTH OF THE AREA HIGHLY ORGANIZED CONVECTION IS UNLIKELY ACROSS THE AREA BUT DO SEE SOME OPPORTUNITY FOR SOME LOOSELY ORGANIZED ACTIVITY OVERNIGHT...WITH EXPANSION LATE THIS EVENING BUT PROBABLY STARTING TO WANE DURING THE LATE OVERNIGHT HOURS. WILL MAINTAIN THE LIKELY POPS AFTER 06Z...WITH LOWER CHANCES JUST BEFORE 06Z IN THE NORTHWEST BASED ON LATEST TRENDS. SOME GUIDANCE CONTINUES TO SUPPORT AN NORTHWARD EXPANSION OF THE MAIN AREA OF CONVECTION TO THE SOUTH OVERNIGHT IN RESPONSE TO THE INCREASE IN THE MAIN LOW LEVEL JET SO BETTER ORGANIZED ACTIVITY IS POSSIBLE IN THE FAR SOUTH SO WILL CONTINUE TO THE HIGHEST QPF IN THAT AREA. HEAVY DOWNPOURS ARE STILL THE PRIMARY THREAT WITH SOME STRONGER WIND GUSTS POSSIBLE AS WELL...ESPECIALLY ACROSS WESTERN AND SOUTHERN AREAS. MDB //PREV DISCUSSION... 142 PM CDT TONIGHT THROUGH TUESDAY... THIS AFTERNOON SKIES HAVE BECOME P-CLOUDY ACROSS THE REGION...WITH SLIGHTLY MORE AGITATED CU FIELD OVER EASTERN COOK COUNTY STRETCHING EAST INTO NORTHWEST IN...WHERE A LAKE BREEZE HAS DEVELOPED AND CONTINUES TO DRIFT INLAND. A FEW SHOWERS/THUNDERSTORMS WERE ALSO ABLE TO DEVELOP ALONG THE LAKE BREEZE IN NORTHWEST INDIANA. GREATER INSTABILITY WAS FOCUSED FURTHER SOUTH ASSOCIATED WITH THE FRONTAL BOUNDARY THAT BROUGHT PRECIP EARLY THIS MORNING TO NORTHERN IL/NORTHWEST IN. THIS AFTN THE FRONTAL BOUNDARY WAS ORIENTED FROM NORTH CENTRAL IN STRETCHING SOUTHWEST THROUGH CENTRAL IL THEN BENDING WEST/NORTHWEST INTO EASTERN NEBRASKA. DEW POINTS BEHIND THIS FEATURE IN NORTHERN IL HAVE BEEN ABLE TO FALL OFF INTO THE LOW/MID 60S...MEANWHILE ALONG AND SOUTH OF THE BOUNDARY ABUNDANT MOISTURE REMAINS WITH DEW PTS STILL IN THE LOW/MID 70S. AFTN TEMPS WILL CONTINUE TO WARM INTO THE MID/UPR 80S. THEN THE FOCUS OVERNIGHT WILL TURN TOWARDS THE WAVE CURRENTLY LOCATED OVER NEBRASKA/SOUTH DAKOTA/SOUTHWEST MINNESOTA. GUIDANCE HAS BEEN STEADILY CONSOLIDATING TOWARDS SLIGHTLY MORE UNIFORM SOLUTION...DEVELOPING A COMPLEX AND BRINGING THE ACTIVITY EAST THEN TURNING SOUTHEAST INTO SOUTHEAST IOWA/NORTHEAST MO...THEN CLIPPING THE SOUTHERN CWFA ARND MIDNIGHT THRU DAYBREAK TUE. THE PLACEMENT OF THE LLVL JET OVERNIGHT WOULD SUGGEST THAT SOME OF THE MOISTURE COULD STILL LIFT NORTH...REACHING THE NORTHERN CWFA ARND 6Z TUE AND CONTINUE THRU ARND DAYBREAK TUE BEFORE DRYING OUT FROM WEST TO EAST TUE MORNING. MID/UPR 60S DEW-PTS WILL LIKELY ADVECT BACK NORTH...WITH THE POTENTIAL FOR SOME OF THE STORMS EASILY PRODUCING BRIEF HEAVY DOWNPOURS. IN REGARDS TO ANY STORMS REACHING SEVERE CRITERIA OVERNIGHT...THIS STILL FAVORS OUR FAR WEST/SOUTHWEST. ALTHOUGH CONFIDENCE HAS DIMINISHED MARGINALLY...GIVEN THE BETTER FOCUS APPEARING TO BE FURTHER SOUTHWEST OF THE AREA. AT THIS TIME IT APPEARS A COMPLEX OF THUNDERSTORMS WILL BE ARRIVING IN THE WEST LATE TONIGHT...THEN BEGINNING TO DECAY DURING THE MORNING HOURS FOCUSED SOUTH OF I-80. THE LOBE OF VORTICITY PROGGED BY MOST GUIDANCE HAS BEEN FOCUSED ALONG THE FRONTAL BOUNDARY...WHICH IS WHY THE CONFIDENCE IN STRONGEST ACTIVITY BEING FURTHER SOUTH REMAINS. OVERNIGHT LOWS WILL REMAIN MILD IN THE MID/UPR 60S...POSSIBLY ARND 70 CLOSER TO DOWNTOWN CHICAGO. MID-LVL TROUGH AXIS STEADILY PIVOTS SOUTHEAST FROM THE UPPER MIDWEST...ARRIVING MID-MORNING TUE. THIS WILL PUSH A COLD FRONT THRU THE FORECAST AREA...WITH FLOW TURNING WEST/NORTHWEST. 850MB THERMAL RIDGE RELAXES WITH TEMPS ARND 12-14 DEG C ARRIVING MIDDAY WITH AFTN HIGHS GENERALLY IN THE UPR 70S TO ARND 80. WITH THE COOLER AIR ALOFT...AND MID-LVL LAPSE RATES STEEPENING...SOME ISOLATED DIURNALLY DRIVEN LOW TOPPED CONVECTION IS POSSIBLE MAINLY ALONG AND EAST OF ROCKFORD TO KANKAKEE. SFC RIDGE WILL SLOWLY BUILD IN TUE NGT...WITH AN ADDTL PUSH OF DRIER AIR AND THINNING CLOUD COVER. TEMPS SHUD BE ABLE TO COOL FURTHER INTO THE 50S TO NEAR 60. CONFIDENCE...HIGH. WEDNESDAY THROUGH THURSDAY... 500MB TROUGH WILL BE OVERHEAD BY EARLY WED...AND LOOKS TO REMAIN IN PLACE THRU THUR BEFORE SLOWLY EJECTING TO THE EAST LATE THUR. SFC RIDGING CONTINUES TO BE PROGGED TO BUILD IN FROM THE WEST...AND BRING MUCH DRIER AND COOLER AIR BACK TO THE FORECAST AREA FOR MID-WEEK. TEMPS ALOFT WILL HOVER ARND 10-13 DEG C...WITH HIGHS GENERALLY IN THE UPR 70S EACH DAY. OVERNIGHT LOWS WILL BE PLEASANT...IN THE UPR 50S TO LOW 60S. FRIDAY THROUGH THE WEEKEND... MINIMAL CHANGES TO THE GOING FORECAST...WITH THE TROUGH EXITING TO THE EAST AND MID-LVL FLOW BECOMING FLAT. AS THE SFC RIDGE PUSHES EAST...LLVL FLOW TURNS SOUTHERLY AND WARM/MOIST AIR BEGINS TO ADVECT BACK ACROSS THE REGION. A WEAK WAVE PUSHES OVERHEAD FRI...WITH A QUASI-STATIONARY BOUNDARY SETTING UP FOR THE WEEKEND AND ALLOWING A SEMI ACTIVE PATTERN. TEMPS WILL RETURN TO THE LOW/MID 80S. BEYOND THE CURRENT EXTENDED PERIODS...ENSEMBLES ARE ADVERTISING A HIGH CONFIDENCE RIDGE DEVELOPING ACROSS WESTERN CANADA AND DIGGING A TROUGH INTO THE GREAT LAKES/HUDSON BAY AREA EARLY NEXT WEEK. IF THIS SCENARIO VERIFIES...TEMPS WILL COOL BACK INTO THE UPR 70S TO KICK-OFF NEXT WEEK. CONFIDENCE...HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SHRA AND A FEW EMBEDDED THUNDERSTORMS EXPECTED OVERNIGHT. * VERY SMALL CHANCE OF A LAKE BREEZE IMPACTING THE TERMINALS LATE THIS AFTERNOON. * POSSIBLE -SHRA THIS AFTERNOON. KJB //DISCUSSION...UPDATED 06Z... THE MAIN WEATHER CONCERNS WILL BE OVER THE NEXT FEW HOURS AS SHOWERS AND THUNDERSTORMS MOVE ACROSS PORTIONS OF NORTHERN ILLINOIS AND NORTHWESTERN INDIANA. CURRENTLY RADAR IMAGERY INDICATES TWO MAIN AREAS OF CONVECTIVE ACTIVITY. THE FIRST IS GRADUALLY SLIDING EAST-SOUTHEASTWARD ACROSS SOUTH CENTRAL WISCONSIN...WITH THE SECOND AREA TO THE SOUTHWEST OF THE AREA ACROSS MISSOURI AND WEST CENTRAL ILLINOIS. IT APPEARS THE SHOWER AND THUNDERSTORM ACTIVITY TO THE NORTH MAY BEGIN TO IMPACT THE TERMINALS WITHIN THE NEXT 2 TO 3 HOURS...WITH THE SOUTHWESTERN AREA OF CONVECTION LIKELY TO REMAIN SOUTH OF THE TERMINALS. ALTHOUGH THE CONVECTION ACROSS SOUTH CENTRAL WISCONSIN HAS BEEN FRAILLY STRONG OVER THE PAST COUPLE HOURS...IT WILL LIKELY UNDERGO WEAKENING OVER THE NEXT COUPLE HOURS AS IT MOVES INTO A LESS FAVORABLE THERMODYNAMIC ENVIRONMENT ACROSS NORTHERN ILLINOIS. IT COULD EVEN LOSE MOST OF THE LIGHTNING AND THUNDER. HOWEVER...I WILL CONTINUE THE THE VCTS MENTION AS SOME THUNDER IS CERTAINLY POSSIBLE OVER THE TERMINALS. THE TIMING IN THE GOING FORECAST STILL APPEARS ON TRACK...WITH IT APPROACHING KRFD AROUND 07 UTC...AND THE EASTERN TERMINALS BETWEEN 08 AND 09 UTC. EXPECT THE ACTIVITY TO MOVE OUT OF THE REGION SHORTLY AFTER DAY BREAK. DURING THE DAY TODAY THE WINDS WILL BE A LITTLE GUSTY OUT OF THE WEST-NORTHWEST...AND THIS MAY BE ENOUGH TO PREVENT A LAKE BREEZE FROM PUSHING FAR ENOUGH INLAND TO IMPACT THE TERMINALS THIS AFTERNOON. THERE COULD BE A FEW ISOLATED SHOWERS AND PERHAPS A THUNDERSTORM ACROSS NORTHERN ILLINOIS AGAIN THIS AFTERNOON AS ANOTHER DISTURBANCE MOVES ACROSS THE AREA. HOWEVER...THIS THREAT IS TOO LOW TO INCLUDE IN THE TAF. KJB //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM-HIGH IN SHRA AT THE TERMINALS OVERNIGHT. * LOW-MEDIUM IN THUNDERSTORMS OVER THE TERMINALS OVERNIGHT. * VERY LOW THAT A LAKE BREEZE WILL IMPACT THE TERMINALS LATE THIS AFTERNOON. * LOW THAT ANY ISOLATED SHRA OR TS WILL AFFECT EITHER TERMINAL THIS AFTERNOON. KJB //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY AND THURSDAY...VFR FRIDAY THROUGH SUNDAY...GENERALLY VFR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE PERIOD. 2% && .MARINE... 215 AM CDT SURFACE LOW PRESSURE IS CURRENTLY SHIFTING EASTWARD ACROSS THE NORTHERN FRINGE OF THE LAKE EARLY THIS MORNING. THIS SYSTEM WILL ALSO PUSH AN ASSOCIATED COLD FRONT EASTWARD ACROSS THE LAKE THIS MORNING. THIS WILL RESULT IN PRIMARILY A WESTERLY WIND SHIFT EARLY THIS MORNING...THEN VEERING FARTHER NORTH-NORTHWEST ACROSS THE NORTHERN HALF OF THE LAKE BY THIS AFTERNOON. HIGH PRESSURE IS EXPECTED TO GRADUALLY SHIFT EASTWARD NEAR THE SOUTHERN END OF LAKE MICHIGAN BY WEDNESDAY EVENING. OVERALL THIS WILL RESULT IN A LIGHT AND SOMEWHAT VARIABLE WIND FIELD ACROSS THE LAKE WEDNESDAY INTO THURSDAY. HOWEVER...LAKE BREEZE INFLUENCES WILL LIKELY LEAD TO AN ONSHORE FLOW REGIME ACROSS THE NEAR SHORE WATERS DURING THE DAY TIME HOURS WEDNESDAY AND THURSDAY. THE SURFACE HIGH IS EXPECTED TO SHIFT EASTWARD TOWARDS THE ATLANTIC COAST LATER IN THE WEEK. AS THIS OCCURS...IT SHOULD ALLOW THE FLOW TO SHIFT BACK OUT OF THE SOUTH OVER THE LAKE INTO THE WEEKEND. IN ADDITION...INCREASING MOISTURE AND ADDITIONAL WEATHER DISTURBANCES LOOK TO INCREASE THE CHANCES FOR SHOWERS AND STORMS AGAIN FOR FRIDAY AND INTO THE WEEKEND. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ 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
1233 AM CDT TUE JUL 8 2014 .DISCUSSION... 825 PM CDT A COLD FRONTAL BOUNDARY CONTINUES TO MOVE SOUTHEAST ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL IOWA WHILE A STATIONARY BOUNDARY IS STRETCHED FROM WEST TO EAST ACROSS THE FAR SOUTHERN CWA. WATER VAPOR SHOWS AN UPPER TROUGH SWINGING SOUTHEASTWARD INTO MINNESOTA WITH SEVERAL EMBEDDED WAVES HELPING TO KICK OFF CONVECTION...WITH ONE COMPLEX OVER WEST CENTRAL MINNESOTA AND ANOTHER ALONG THE IA/MO BORDER. THE CWA IS EXPECTED TO REMAIN BETWEEN THE TWO CURRENT AREAS OF CONVECTION BUT ADDITIONAL DEVELOPMENT IS EXPECTED JUST WEST OR OVER THE AREA LATER TONIGHT AS THE FRONT AND AN UPPER WAVE PASS. LATEST GUIDANCE SUGGESTS THAT THE MID LEVEL WAVE WILL AMPLIFY BRINGING AN ATTENDANT SPEED MAX ACROSS THE AREA INTO THE OVERNIGHT HOURS. ACTIVITY ALONG THE FRONT NEAR THE IA/MN BORDER HAS BEEN FESTERING BUT RAP ANALYSIS INDICATES THAT THERE IS STRONGER AXIS OF INSTABILITY ACROSS NORTHEAST IA THAT IS UNCAPPED SO SOME ENHANCEMENT IS POSSIBLE GOING FORWARD. EVENING DVN SOUNDING SHOWS A CAP IN PLACE WITH LOCAL AIRCRAFT SOUNDINGS SHOWING A MINIMAL CAP. WOULD THINK THIS CAP WOULD ERODE WITH THE INCREASE IN MID/UPPER ASCENT INTO THE OVERNIGHT. WITH MOISTURE FLUX AND PRIMARY LOW LEVEL JET WELL SOUTH OF THE AREA HIGHLY ORGANIZED CONVECTION IS UNLIKELY ACROSS THE AREA BUT DO SEE SOME OPPORTUNITY FOR SOME LOOSELY ORGANIZED ACTIVITY OVERNIGHT...WITH EXPANSION LATE THIS EVENING BUT PROBABLY STARTING TO WANE DURING THE LATE OVERNIGHT HOURS. WILL MAINTAIN THE LIKELY POPS AFTER 06Z...WITH LOWER CHANCES JUST BEFORE 06Z IN THE NORTHWEST BASED ON LATEST TRENDS. SOME GUIDANCE CONTINUES TO SUPPORT AN NORTHWARD EXPANSION OF THE MAIN AREA OF CONVECTION TO THE SOUTH OVERNIGHT IN RESPONSE TO THE INCREASE IN THE MAIN LOW LEVEL JET SO BETTER ORGANIZED ACTIVITY IS POSSIBLE IN THE FAR SOUTH SO WILL CONTINUE TO THE HIGHEST QPF IN THAT AREA. HEAVY DOWNPOURS ARE STILL THE PRIMARY THREAT WITH SOME STRONGER WIND GUSTS POSSIBLE AS WELL...ESPECIALLY ACROSS WESTERN AND SOUTHERN AREAS. MDB //PREV DISCUSSION... 142 PM CDT TONIGHT THROUGH TUESDAY... THIS AFTERNOON SKIES HAVE BECOME P-CLOUDY ACROSS THE REGION...WITH SLIGHTLY MORE AGITATED CU FIELD OVER EASTERN COOK COUNTY STRETCHING EAST INTO NORTHWEST IN...WHERE A LAKE BREEZE HAS DEVELOPED AND CONTINUES TO DRIFT INLAND. A FEW SHOWERS/THUNDERSTORMS WERE ALSO ABLE TO DEVELOP ALONG THE LAKE BREEZE IN NORTHWEST INDIANA. GREATER INSTABILITY WAS FOCUSED FURTHER SOUTH ASSOCIATED WITH THE FRONTAL BOUNDARY THAT BROUGHT PRECIP EARLY THIS MORNING TO NORTHERN IL/NORTHWEST IN. THIS AFTN THE FRONTAL BOUNDARY WAS ORIENTED FROM NORTH CENTRAL IN STRETCHING SOUTHWEST THROUGH CENTRAL IL THEN BENDING WEST/NORTHWEST INTO EASTERN NEBRASKA. DEW POINTS BEHIND THIS FEATURE IN NORTHERN IL HAVE BEEN ABLE TO FALL OFF INTO THE LOW/MID 60S...MEANWHILE ALONG AND SOUTH OF THE BOUNDARY ABUNDANT MOISTURE REMAINS WITH DEW PTS STILL IN THE LOW/MID 70S. AFTN TEMPS WILL CONTINUE TO WARM INTO THE MID/UPR 80S. THEN THE FOCUS OVERNIGHT WILL TURN TOWARDS THE WAVE CURRENTLY LOCATED OVER NEBRASKA/SOUTH DAKOTA/SOUTHWEST MINNESOTA. GUIDANCE HAS BEEN STEADILY CONSOLIDATING TOWARDS SLIGHTLY MORE UNIFORM SOLUTION...DEVELOPING A COMPLEX AND BRINGING THE ACTIVITY EAST THEN TURNING SOUTHEAST INTO SOUTHEAST IOWA/NORTHEAST MO...THEN CLIPPING THE SOUTHERN CWFA ARND MIDNIGHT THRU DAYBREAK TUE. THE PLACEMENT OF THE LLVL JET OVERNIGHT WOULD SUGGEST THAT SOME OF THE MOISTURE COULD STILL LIFT NORTH...REACHING THE NORTHERN CWFA ARND 6Z TUE AND CONTINUE THRU ARND DAYBREAK TUE BEFORE DRYING OUT FROM WEST TO EAST TUE MORNING. MID/UPR 60S DEW-PTS WILL LIKELY ADVECT BACK NORTH...WITH THE POTENTIAL FOR SOME OF THE STORMS EASILY PRODUCING BRIEF HEAVY DOWNPOURS. IN REGARDS TO ANY STORMS REACHING SEVERE CRITERIA OVERNIGHT...THIS STILL FAVORS OUR FAR WEST/SOUTHWEST. ALTHOUGH CONFIDENCE HAS DIMINISHED MARGINALLY...GIVEN THE BETTER FOCUS APPEARING TO BE FURTHER SOUTHWEST OF THE AREA. AT THIS TIME IT APPEARS A COMPLEX OF THUNDERSTORMS WILL BE ARRIVING IN THE WEST LATE TONIGHT...THEN BEGINNING TO DECAY DURING THE MORNING HOURS FOCUSED SOUTH OF I-80. THE LOBE OF VORTICITY PROGGED BY MOST GUIDANCE HAS BEEN FOCUSED ALONG THE FRONTAL BOUNDARY...WHICH IS WHY THE CONFIDENCE IN STRONGEST ACTIVITY BEING FURTHER SOUTH REMAINS. OVERNIGHT LOWS WILL REMAIN MILD IN THE MID/UPR 60S...POSSIBLY ARND 70 CLOSER TO DOWNTOWN CHICAGO. MID-LVL TROUGH AXIS STEADILY PIVOTS SOUTHEAST FROM THE UPPER MIDWEST...ARRIVING MID-MORNING TUE. THIS WILL PUSH A COLD FRONT THRU THE FORECAST AREA...WITH FLOW TURNING WEST/NORTHWEST. 850MB THERMAL RIDGE RELAXES WITH TEMPS ARND 12-14 DEG C ARRIVING MIDDAY WITH AFTN HIGHS GENERALLY IN THE UPR 70S TO ARND 80. WITH THE COOLER AIR ALOFT...AND MID-LVL LAPSE RATES STEEPENING...SOME ISOLATED DIURNALLY DRIVEN LOW TOPPED CONVECTION IS POSSIBLE MAINLY ALONG AND EAST OF ROCKFORD TO KANKAKEE. SFC RIDGE WILL SLOWLY BUILD IN TUE NGT...WITH AN ADDTL PUSH OF DRIER AIR AND THINNING CLOUD COVER. TEMPS SHUD BE ABLE TO COOL FURTHER INTO THE 50S TO NEAR 60. CONFIDENCE...HIGH. WEDNESDAY THROUGH THURSDAY... 500MB TROUGH WILL BE OVERHEAD BY EARLY WED...AND LOOKS TO REMAIN IN PLACE THRU THUR BEFORE SLOWLY EJECTING TO THE EAST LATE THUR. SFC RIDGING CONTINUES TO BE PROGGED TO BUILD IN FROM THE WEST...AND BRING MUCH DRIER AND COOLER AIR BACK TO THE FORECAST AREA FOR MID-WEEK. TEMPS ALOFT WILL HOVER ARND 10-13 DEG C...WITH HIGHS GENERALLY IN THE UPR 70S EACH DAY. OVERNIGHT LOWS WILL BE PLEASANT...IN THE UPR 50S TO LOW 60S. FRIDAY THROUGH THE WEEKEND... MINIMAL CHANGES TO THE GOING FORECAST...WITH THE TROUGH EXITING TO THE EAST AND MID-LVL FLOW BECOMING FLAT. AS THE SFC RIDGE PUSHES EAST...LLVL FLOW TURNS SOUTHERLY AND WARM/MOIST AIR BEGINS TO ADVECT BACK ACROSS THE REGION. A WEAK WAVE PUSHES OVERHEAD FRI...WITH A QUASI-STATIONARY BOUNDARY SETTING UP FOR THE WEEKEND AND ALLOWING A SEMI ACTIVE PATTERN. TEMPS WILL RETURN TO THE LOW/MID 80S. BEYOND THE CURRENT EXTENDED PERIODS...ENSEMBLES ARE ADVERTISING A HIGH CONFIDENCE RIDGE DEVELOPING ACROSS WESTERN CANADA AND DIGGING A TROUGH INTO THE GREAT LAKES/HUDSON BAY AREA EARLY NEXT WEEK. IF THIS SCENARIO VERIFIES...TEMPS WILL COOL BACK INTO THE UPR 70S TO KICK-OFF NEXT WEEK. CONFIDENCE...HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SHRA AND A FEW EMBEDDED THUNDERSTORMS EXPECTED OVERNIGHT. * VERY SMALL CHANCE OF A LAKE BREEZE IMPACTING THE TERMINALS LATE THIS AFTERNOON. * POSSIBLE -SHRA THIS AFTERNOON. KJB //DISCUSSION...UPDATED 06Z... THE MAIN WEATHER CONCERNS WILL BE OVER THE NEXT FEW HOURS AS SHOWERS AND THUNDERSTORMS MOVE ACROSS PORTIONS OF NORTHERN ILLINOIS AND NORTHWESTERN INDIANA. CURRENTLY RADAR IMAGERY INDICATES TWO MAIN AREAS OF CONVECTIVE ACTIVITY. THE FIRST IS GRADUALLY SLIDING EAST-SOUTHEASTWARD ACROSS SOUTH CENTRAL WISCONSIN...WITH THE SECOND AREA TO THE SOUTHWEST OF THE AREA ACROSS MISSOURI AND WEST CENTRAL ILLINOIS. IT APPEARS THE SHOWER AND THUNDERSTORM ACTIVITY TO THE NORTH MAY BEGIN TO IMPACT THE TERMINALS WITHIN THE NEXT 2 TO 3 HOURS...WITH THE SOUTHWESTERN AREA OF CONVECTION LIKELY TO REMAIN SOUTH OF THE TERMINALS. ALTHOUGH THE CONVECTION ACROSS SOUTH CENTRAL WISCONSIN HAS BEEN FRAILLY STRONG OVER THE PAST COUPLE HOURS...IT WILL LIKELY UNDERGO WEAKENING OVER THE NEXT COUPLE HOURS AS IT MOVES INTO A LESS FAVORABLE THERMODYNAMIC ENVIRONMENT ACROSS NORTHERN ILLINOIS. IT COULD EVEN LOSE MOST OF THE LIGHTNING AND THUNDER. HOWEVER...I WILL CONTINUE THE THE VCTS MENTION AS SOME THUNDER IS CERTAINLY POSSIBLE OVER THE TERMINALS. THE TIMING IN THE GOING FORECAST STILL APPEARS ON TRACK...WITH IT APPROACHING KRFD AROUND 07 UTC...AND THE EASTERN TERMINALS BETWEEN 08 AND 09 UTC. EXPECT THE ACTIVITY TO MOVE OUT OF THE REGION SHORTLY AFTER DAY BREAK. DURING THE DAY TODAY THE WINDS WILL BE A LITTLE GUSTY OUT OF THE WEST-NORTHWEST...AND THIS MAY BE ENOUGH TO PREVENT A LAKE BREEZE FROM PUSHING FAR ENOUGH INLAND TO IMPACT THE TERMINALS THIS AFTERNOON. THERE COULD BE A FEW ISOLATED SHOWERS AND PERHAPS A THUNDERSTORM ACROSS NORTHERN ILLINOIS AGAIN THIS AFTERNOON AS ANOTHER DISTURBANCE MOVES ACROSS THE AREA. HOWEVER...THIS THREAT IS TOO LOW TO INCLUDE IN THE TAF. KJB //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM-HIGH IN SHRA AT THE TERMINALS OVERNIGHT. * LOW-MEDIUM IN THUNDERSTORMS OVER THE TERMINALS OVERNIGHT. * VERY LOW THAT A LAKE BREEZE WILL IMPACT THE TERMINALS LATE THIS AFTERNOON. * LOW THAT ANY ISOLATED SHRA OR TS WILL AFFECT EITHER TERMINAL THIS AFTERNOON. KJB //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY AND THURSDAY...VFR FRIDAY THROUGH SUNDAY...GENERALLY VFR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE PERIOD. 2% && .MARINE... 152 PM CDT NO MAJOR CONCERNS THROUGH THE PERIOD FOR THE MARINE FORECAST...WITH FOCUS MAINLY ON A SERIES OF RELATIVELY WEAK COLD FRONTAL PASSAGES THROUGH TUESDAY BEFORE HIGH PRESSURE SPREADS ACROSS THE WESTERN LAKES LATER WEDNESDAY NIGHT AND THURSDAY. IN THE NEAR TERM...LOW PRESSURE WAS PASSING NORTH OF THE LAKES FROM NORTHEASTERN ONTARIO INTO QUEBEC EARLY THIS AFTERNOON WITH A COLD FRONT TRAILING SOUTHWEST INTO FAR NORTHWEST INDIANA JUST SOUTH OF THE LAKE MICHIGAN SHORE AT 18Z. WINDS HAD BECOME VARIABLE ON THE SOUTHERN PORTION OF THE LAKE IN THE BAGGY GRADIENT BEHIND THE COLD FRONT...ALLOWING WEAK LAKE BREEZE DEVELOPMENT AROUND THE SOUTH END OF THE LAKE. FARTHER NORTH...WINDS HAVE BACKED TO THE SOUTHWEST WITH THE GRADIENT TIGHTENING A BIT IN ADVANCE OF THE NEXT MID-LEVEL DISTURBANCE TRACKING ACROSS THE UPPER MIDWEST. THIS MID-LEVEL WAVE WILL MOVE ACROSS THE REGION LATER TONIGHT...ALLOWING ANOTHER WEAK COLD FRONT TO SAG ACROSS THE NORTHERN PART OF THE LAKE LATE TONIGHT. YET ANOTHER MORE AMPLIFIED DISTURBANCE WILL SPREAD OVER THE WESTERN LAKES TUESDAY...WITH A DEVELOPING WEAK AREA OF SURFACE LOW PRESSURE MOVING EAST OF THE LAKE BY THE AFTERNOON AND NORTHWEST WINDS DEVELOPING. SPEEDS LOOK TO REMAIN FAIRLY MODEST...GENERALLY IN THE 15-20 KT RANGE DURING HIGHEST PERIODS. A THIRD DISTURBANCE SWINGS ACROSS THE NORTHERN LAKES...WI/MI LATE TUESDAY NIGHT...RESULTING IN SOME BACKING OF THE WINDS ON NORTHERN LAKE MICHIGAN...BUT THESE TOO TURN NORTHWEST AGAIN BY WEDNESDAY AFTERNOON. HIGH PRESSURE THEN PRESSES EASTWARD INTO THE MISSISSIPPI RIVER VALLEY BY WEDNESDAY EVENING...AND ACROSS LAKE MICHIGAN WEDNESDAY NIGHT AND THURSDAY. WINDS WILL THEN BECOME SOUTH-SOUTHEAST THURSDAY NIGHT AS THE RIDGE MOVES OFF TO THE EAST. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ 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 DODGE CITY KS
235 AM CDT Tue Jul 8 2014 ...UPDATE TO LONG TERM... .SHORT TERM...(This evening through Tuesday) ISSUED AT 227 PM CDT MON JUL 7 2014 Tonight: The main focus for tonight is where convection will be located and how severe. Right now, visible satellite imagery shows some developing cumulus across the Plains of east-central Colorado. Expect further development of cumulus into northwest Kansas through the afternoon. This activity is along a frontal boundary. Convective allowing models break out thunderstorms this evening with the best chances along the I-70 corridor. Storms may extend all the way down to Highway 96, though, later tonight. As far as severity, some of the models want to mix out current dewpoints, which, so far, is not happening as much as the models indicate. Running the thermodynamic and wind-related parameters through the Large Hail Parameter (LHP) comes up with a value of 6. This basically suggests that hail could potentially be up to the size of golf balls. Not really sure if we will get a sustained weakly rotating updraft or not, so hail could be smaller. There is not a threat of tornadoes. There could be 60+ mph outflow winds, as an inverted-v thermodynamic profile is expected. Have the highest pops for Trego and Ellis counties and then taper values quickly southward as thunderstorms are not expected along and south of a line from Coolidge to St. John. The most recent HRRR has storms south of this line, however, this model tends to overdo cold pools and resultant upscale growth. Overnight lows will be in the 60s/70s. Tomorrow: Much cooler temperatures are expected for tomorrow as the aforementioned front sinks south of the region. Have lowered maximums as the majority of the models are now cooler with "cold" air advection in the wake of the front. Expecting maximums mostly in the mid 80s along with 10-20 mph N/NE winds. There could be some storms along and south of the Arkansas river...have slight pops in after 21Z, but most of the precipitation will be during the long term period. .LONG TERM...(Wednesday through Monday) ISSUED AT 230 AM CDT TUE JUL 8 2014 Medium range models indicate a northwesterly flow aloft prevailing across the Western High Plains early in the period Wednesday as an upper level ridge axis slowly shifts eastward across the Intermountain West. A series of H5 vort maxima are projected to cycle off the ridge axis and drop southeastward across the high plains of eastern Colorado and western Kansas. Meanwhile, a prevailing southeasterly flow near the surface will continue to draw ample moisture up into central and western Kansas while a lee side trough of low pressure develops across eastern Colorado. As a result, thunderstorms are likely across eastern Colorado Wednesday afternoon as lower/mid level lapse rates steepen across the high plains. These storms will drift eastward, potentially moving into west central and southwest Kansas overnight. Additional thunderstorm development will be possible across central Kansas toward early Thursday morning as the surface trough axis pushes eastward across western Kansas overnight. This and surface high pressure parked across the Great Lakes Region will enhance an area of convergence across central and eastern Kansas, not to mention an axis of higher surface dewpoints being drawn northwest into central Kansas within the upslope flow. Although the flow aloft is expected to be less than favorable, enough forcing/lift near the surface will exist to support thunderstorm development across central Kansas early Thursday with any storms moving off to the east by the afternoon time frame. Drier conditions are expected Friday as the upper level ridge moves further east out of the Rockies into the Western High Plains. Near normal temperatures are likely Wednesday as a lee side trough of low pressure develops across eastern Colorado while surface high pressure drops southeast out of the Northern Plains into the southern Great Lakes Region. This will set up a south to southeasterly flow into western Kansas drawing slightly warmer air north into western Kansas. The GFS/ECMWF show H85 temperatures warming slightly from the day previous with values in the lower 20s(C) across central Kansas to near 30C in extreme southwest Kansas. With GFS/ECMWF model soundings showing steep low level lapse rates developing by Wednesday afternoon, look for highs well up into the mid to upper 80s(F) across central Kansas with lower to mid 90s(F) across much of southwest Kansas. Widespread 90s(F) are expected Thursday and Friday as the warming trend continues through the end of the week. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1209 AM CDT TUE JUL 8 2014 Conditions will continue to be VFR, with mid level cigs in the bkn100 range. There is just a slight chance for thunderstorms at the GCK and DDC TAF sites, but confidence is not high enough to include in TAFS. Winds will generally be from the northeast at 15g25kts tonight, and then becoming north at 7 to 8 knots around 18Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 86 64 89 68 / 10 20 20 30 GCK 85 63 90 67 / 10 20 20 20 EHA 85 64 93 70 / 20 30 20 30 LBL 87 65 94 69 / 20 30 20 20 HYS 85 61 89 67 / 10 10 20 30 P28 89 67 90 69 / 20 20 20 30 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Sugden LONG TERM...JJohnson AVIATION...Burke
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1225 AM CDT Tue Jul 8 2014 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Tuesday) Issued at 259 PM CDT MON JUL 7 2014 Currently monitoring visible satellite this afternoon where multiple boundaries are positioned across the region. A weak boundary was tracking southeast through the CWA while a stronger area of outflow winds was pushing southward into southern NE and far northern KS. A weak warm front resided near the KS/NE border while the stronger cold front was located over southern SD. Remnant cloud cover from this morning`s showers were finally exiting east central KS, allowing temps to quickly rise into the 90s, as heat indices approach the low 100s. Dewpoints continue to mix down into the low and middle 60s. On the water vapor in the mid levels, two vorticity maxima were noted over northern NE and a stronger wave dropping southeast from North Dakota. Late this afternoon, surface CAPE near 3000 J/KG while effective shear increases between 30 and 50 kts is supportive of strong to severe convection. Main limiting factor for surface based convection is the capping inversion holding across much of the area as seen on the 19Z KTOP RAOB. Latest 4-KM WRF, HRRR, and RUC keep convection at bay until after 00Z but could not entirely rule out a few updrafts developing along the leading outflow boundary or warm front in vicinity of KS/NE border. If a storm develops, it will be capable of large hail and damaging winds. Highest chances for severe convection reside after 00Z as scattered storms along the reinforcing cold front and upper trough shift south and east across Nebraska, northeast Kansas, and northern Missouri. the progressive nature of the system, in addition to stout forward propagating Corfidi vectors approaching 55 to 60 kts signal damaging winds to be the primary hazards with this evening`s storms. Large hail is also possible. Locally heavy rainfall will depend on the speed of the line and any training convection that occurs towards central KS along the boundary. Tornado potential is low in far northern KS where the frontal boundary and weak low level shear maximizes near 15 kts. Likely precip chances were focused over northern, northeast, and east central areas based on the position of the upper trough axis as the main line of storms quickly shifts southeast overnight. Guidance is on track to clear precip through by Tuesday mid morning as skies become mostly sunny during the afternoon. A cooler and stable airmass in the system`s wake will only bring temps to the 80s for highs. Northerly winds increase between 10 and 15 mph sustained. .LONG TERM...(Tuesday Night through Monday) Issued at 259 PM CDT MON JUL 7 2014 Wed/Thurs...Should have a cool night Tuesday night as skies clear and cooler airmass with lower dewpoints slides southward into the forecast area. Strong sunshine and deeper mixing on Wednesday should return high temperatures back into the middle 80s east to upper 80s west. Still some consensus that front retreats back northeast overnight Wednesday night into Thursday and brings a chance for storms as it does so, although coverage may be shut down quickly as warm temps and cap return aloft by the late afternoon Thursday. Eastern counties may be able to stay a few degrees cooler depending on how fast clouds and precip chances diminish. As upper flow becomes slightly northwest into Thursday night, passing wave still progged to generate an MCS mainly north of our area then sliding east. Kept slight chances as some models slide this boundary into our forecast area. Some discrepancies in the extended as EC lays this boundary over the area through the weekend while GFS is farther north and a warmer drier solution. The GFS ensembles favor the warmer pattern and have left the extended as such. && .AVIATION...(For the 06Z TAFs through 06Z Tuesday Night) Issued at 1225 AM CDT TUE JUL 8 2014 TSRA still likely to affect the terminals through 09Z. Not expecting strong wind gusts with these storms. Winds will be variable then become north. VFR cigs expected with MVFR vsbys with the TSRA. Clouds scatter out after 12Z and north winds around 10 kts are expected after 14Z, then decrease after 02Z Wednesday. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Bowen LONG TERM...67 AVIATION...53
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1215 AM CDT Tue Jul 8 2014 ...Updated for the aviation discussion... .SHORT TERM...(This evening through Tuesday) ISSUED AT 227 PM CDT MON JUL 7 2014 Tonight: The main focus for tonight is where convection will be located and how severe. Right now, visible satellite imagery shows some developing cumulus across the Plains of east-central Colorado. Expect further development of cumulus into northwest Kansas through the afternoon. This activity is along a frontal boundary. Convective allowing models break out thunderstorms this evening with the best chances along the I-70 corridor. Storms may extend all the way down to Highway 96, though, later tonight. As far as severity, some of the models want to mix out current dewpoints, which, so far, is not happening as much as the models indicate. Running the thermodynamic and wind-related parameters through the Large Hail Parameter (LHP) comes up with a value of 6. This basically suggests that hail could potentially be up to the size of golf balls. Not really sure if we will get a sustained weakly rotating updraft or not, so hail could be smaller. There is not a threat of tornadoes. There could be 60+ mph outflow winds, as an inverted-v thermodynamic profile is expected. Have the highest pops for Trego and Ellis counties and then taper values quickly southward as thunderstorms are not expected along and south of a line from Coolidge to St. John. The most recent HRRR has storms south of this line, however, this model tends to overdo cold pools and resultant upscale growth. Overnight lows will be in the 60s/70s. Tomorrow: Much cooler temperatures are expected for tomorrow as the aforementioned front sinks south of the region. Have lowered maximums as the majority of the models are now cooler with "cold" air advection in the wake of the front. Expecting maximums mostly in the mid 80s along with 10-20 mph N/NE winds. There could be some storms along and south of the Arkansas river...have slight pops in after 21Z, but most of the precipitation will be during the long term period. .LONG TERM...(Tuesday night through Monday) ISSUED AT 308 PM CDT MON JUL 7 2014 The cold front which will come down Tuesday will slow its southward push and weaken Tuesday Night. The frontal zone, around 800mb will be across the northern Panhandles northeastward along the KS-OK border, which will be a focus for at least isolated or widely scattered thunderstorms. It is still unclear whether a small mesoscale convective system (MCS) will develop along the frontal zone or not (and if so, whether it will be this far north into southwest Kansas or not). For now, we will keep Chance POPs (25+) across far southwest Kansas from roughly Elkhart to Meade with Slight Chance (15-24) from roughly Scott City to Stafford. The front will dissolve by Wednesday, however temperatures will still be mild by early/mid July standards with highs in the upper 80s to lower 90s. Any thunderstorms Wednesday through early/mid evening should be confined to the higher terrain west of the southwest Kansas region. Warm frontogenesis will increase in the 06-12Z time frame early Thursday morning in the 850-700mb layer, and we will continue to carry Chance POPs across central and south-central Kansas. The updated forecast does reduce the POPs along/west of Highway 283, though. The summer ridge will build in the mid-upper troposphere with lower troposphere responding with quite a bit warmer temperatures in the +27 to +29C range at 850mb. Even slightly warmer temperatures Friday will support afternoon surface temperatures in the 99 to 101F territory. We will carry some Slight Chance POPs in the western/northwester zones for mainly diurnal lee trough/higher terrain storms which may drift into western Kansas. As we head into the upcoming weekend, we will start to see some amplification occurring in the jet stream pattern cross northwestern North America, with a pronounced ridge developing along the Pacific Coast of British Columbia. This would lead to downstream troughing throughout much of the rest of Canada into the Upper Midwest region of the CONUS. What this would mean for southwestern Kansas is the eventual frontal passage, perhaps as early as late Saturday (ECMWF) or Sunday (Canadian GEM). During the 14-17 July time frame, there is a large degree of uncertainty in how the upper tropospheric pattern will play out, but the ECMWF does suggest a much cooler and wetter scenario during this 8-10 Day time frame. To a lesser degree, the GFS does hint at this, but is also quite a bit delayed in longwave troughing across the northern CONUS. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1209 AM CDT TUE JUL 8 2014 Conditions will continue to be VFR, with mid level cigs in the bkn100 range. There is just a slight chance for thunderstorms at the GCK and DDC TAF sites, but confidence is not high enough to include in TAFS. Winds will generally be from the northeast at 15g25kts tonight, and then becoming north at 7 to 8 knots around 18Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 64 88 68 97 / 20 20 20 20 GCK 63 89 67 98 / 20 20 20 10 EHA 64 91 70 98 / 30 20 20 10 LBL 65 92 69 99 / 30 20 20 10 HYS 63 88 67 95 / 10 10 30 30 P28 67 89 69 96 / 20 20 30 30 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Sugden LONG TERM...Umscheid AVIATION...Burke
AREA FORECAST DISCUSSION
NWS PADUCAH KY
259 AM CDT Tue Jul 8 2014 .SHORT TERM...(Today through Thursday) Issued at 258 AM CDT TUE JUL 8 2014 The bulk of the short term period will be dependent on the evolution of the MCS just about to enter southwest Illinois and southeast Missouri. The leading line convection has diminished significantly, as have the winds behind the line. Have not seen any severe wind reports for quite awhile upstream, and really would not expect the system to increase. The RAP indicates that the 0-3km shear is very weak and parallel to the leading line. There appears to be a comma head/MCV feature moving east across central Illinois, and that should continue to push away from our area. Meanwhile, Corfidi Vectors over Missouri indicate a southward propagation. Therefore, we may be in for some sort of split for our area. There is decent surface air, theta-e values in the 345-349 range, throughout southern Illinois and southeast Missouri, so would expect convection to continue to bounce around on the outflow boundary as it moves southeast through southern Illinois and southeast Missouri through daybreak. With disorganized leading convection, figure the stratiform area will also begin to diminish, so there will likely be a significant weakening trend in the coverage of precipitation over the area in the 12z-15Z timeframe. The big question then is where will storms be able to fire up this afternoon and evening? The cold front is located from southeast Iowa to north central Kansas as of 730Z, and it does not have a tremendous push with it. The consensus of 00Z guidance brings into the northwest part of the region this afternoon, and surface dewpoints in the lower 70s are expected ahead of the front. Therefore, much of the area may be under the gun for more convection along and ahead of the cold front this afternoon and evening. The hi-res guidance really seems to be focusing on the southern third of the area for development. Perhaps the MCS will thoroughly stabilize the airmass across the northern half of the area. I really don`t have a good feel for this one. Decided to go with a band of low-end likely PoPs in the north around 18Z, and then push it slowly southeast through the afternoon and into the evening. Feel that it will be out of the area by 06Z tonight, but left a chancy PoP in the southeast overnight just to be safe. Enough dry air should arrive to keep the area dry for Wednesday, despite decent cyclonic flow aloft. A few severe storms will be possible this afternoon, if we can destabilize enough. The wind fields should be strong enough to support a few severe storms with damaging winds the main concern. Temperatures today are a crap shoot with the convection and convective debris expected. Therefore, went close to consensus guidance. Went on the warm side of guidance for tonight with only weak cool, dry advection expected. Consensus should be close again Wednesday with the dry air advecting/mixing across the region. Trended a bit cooler for Wednesday night and warmer Thursday, both due to the dry airmass expected. .LONG TERM...(Thursday Night through Monday) Issued at 258 AM CDT TUE JUL 8 2014 High pressure will continue to bring dry weather Thursday night before moving off to the east on Friday. Temperatures and dewpoints will climb a couple of degrees per day through the weekend on warm and moist low level winds. Thursday night lows in the middle 60s will give way to lows over the weekend in the lower 70s. Highs will nudge up from the upper 80s on Friday into the lower 90s for the weekend. Aloft, the region will stay in northwesterly flow on the fringe of an upper level low. While an isolated chance of a shower or storm will be possible on Saturday, the better chance will come Sunday as an upper level disturbance moves north of the region. Chance pops in the northeastern part of the forecast area will lower to slight pops over the Ozark foothills. Models are highly variable with the weather early next week. The GFS aggressively pushes a front through the Ohio Valley on Monday and stalls it over the Tennessee Valley before lifting back north late Tuesday hinting at a very wet period for our region. The ECMWF on the other hand is much weaker with the front on Monday but does also stall it to our south. It, however, keeps it to our south through the better part of the week with energy producing rain chances up around the Great Lakes and to our south along the stalled boundary. At any rate, have high chance pops on Monday with the passage of a frontal boundary. Temperatures will be tempered somewhat on Monday with cloud cover and precipitation with highs back down into the upper 80s. && .AVIATION... Issued at 1159 PM CDT MON JUL 7 2014 Thunderstorm complex barreling across Missouri will likely impact the region late tonight. Given the trajectory into a better feed of instability, current thinking is that KCGI and KPAH both stand the better chance of impact later tonight versus KEVV and KOWB. While the overnight activity weakens and diminishes through the morning, more outflow focused development is expected to regenerate with peak heating as a cold front drops south across the area. This should largely be south of the area by 00Z Wednesday. VFR conditions will prevail outside of thunderstorm activity. South winds 5 to 10 knots tonight will become southwest at 10 to 15 knots with gusts to 20 knots on Tuesday. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ SHORT TERM...DRS LONG TERM...ML AVIATION...RJP
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
114 AM EDT Tue Jul 8 2014 ...Updated Aviation Discussion... ...Forecast Update... Issued at 1100 PM EDT Mom Jul 7 2014 The HRRR short range model has initialized the current convection across the area quite well. For the rest of this evening and the early morning hours expect mostly dry conditions once light rain across south central Kentucky dissipates by midnight. No new convection is expected until a fast moving storm complex now over northern Missouri moves into west central Kentucky and southern Indiana during the pre-dawn hours. Precipitation chances will, therefore ramp up again around dawn, especially for locations south of Interstate 64 and west of I - 65 .SHORT TERM (Now through Tuesday)... Issued at 308 PM EDT Mon Jul 7 2014 This afternoon a cold front extended from the Great Lakes through Illinois and Missouri to the Great Plains. Storms have fired ahead of this front, especially between Indianapolis and St Louis in an area of maximized deep moisture convergence and CAPE. These storms will slide to the ESE and will provide southern Indiana and northern sections of central Kentucky with scattered storms this evening. By the time the storms reach here they will likely begin to weaken, so any severe weather that might occur will be isolated. Locally heavy downpours and gusty winds will be the main threats. Tonight an MCS will advance from Kansas/Nebraska this evening into IL/IN/OH early Tuesday morning. The LMK CWA will be on the southern edge of this feature, with showers and a few thunderstorms possible in southern Indiana and northern Kentucky as we`re waking up Tuesday morning. Those showers/storms are not expected to be severe. By Tuesday afternoon a line of storms is expected to erupt in the vicinity of the Ohio River. The synoptic cold front, an outflow boundary from the morning MCS, and differential heating will all be possible triggers to get the storms going. We`ll also have an upper trof entering the picture from the northwest. Though instability is always in question when we have morning clouds and showers, we should become unstable enough by afternoon such that severe weather will be a threat. Soundings are increasingly showing dry air aloft and bowing echoes are possible, so strong gusty winds will be the main threat. Precipitable water amounts around 2 inches will lead to locally torrential downpours. Tuesday evening the line of strong/severe storms will proceed through central and southern Kentucky. The strongest storms will weakening and move out of the area overnight. Tonight will be muggy, though southwest breezes will keep up around 10 mph through the night to help it feel a little better outside. Lows will be around 70. High temperatures Tuesday will be highly dependent on cloud cover...will go with middle and upper 80s. Tuesday night we`ll see rain-cooled lows in the middle and upper 60s. .LONG TERM (Tuesday Night through Sunday)... Issued at 245 PM EDT Mon Jul 7 2014 The synoptic pattern at the start of the long term period will feature rather amplified flow for mid July, with an amplified ridge across the western CONUS and an eastern trough centered over the Great Lakes region. This pattern will slowly de-amplify through the long term period, allowing the heat and humidity to return this upcoming weekend after a brief reprieve this week. Wednesday will begin with a cold front pushing southeast of the region. The overall trend in numerical guidance with this front has continued to be quicker, thus think most will remain dry Wednesday as cooler/drier air filters into the region. The only exception may be across southern KY where their proximity to the front may allow for a few lingering showers/storms, mostly during the first part of the day. It will feel quite pleasant, as highs will only top out in the low to mid 80s with reduced humidity values. The pleasant conditions will continue Thursday into Friday as another 1020+ mb surface ridge settles over the region. This ridge will allow for highs in the low to mid 80s Thursday, pushing into the mid and upper 80s Friday. However, both days will still be seasonably pleasant as dewpoints will only be in the upper 50s to lower 60s. The forecast becomes a bit more murky this weekend, as guidance begins to diverge. The GFS is the most aggressive with building an upper-level ridge into the region, which would limit convective activity due to capping aloft. However, the GEM/Euro/GFS Ensemble are in better agreement that this ridge will remain more to the southwest, placing the region in the better northwesterly flow aloft making for a more active period. Will lean towards the more active solution, which brings chances for showers/storms beginning Friday night and lasting at least through the end of the long term period. Temperatures this weekend will be tough given the convective potential, but it will be muggier with highs in the upper 80s to lower 90s. && .AVIATION (06Z TAF Update)... Issued at 100 AM EDT Tue Jul 8 2014 Earlier convection has ended across the area. VFR ceilings and southwest winds of around 5 to 10 mph are expected overnight through the early morning period at all TAF sites. A strong line of thunderstorms now over Missouri and Illinois will weaken some as it approaches southwestern Indiana and western Kentucky during the pre-dawn hours. However, it is expected to still bring a round of thunderstorms to SDF and BWG and probably LEX. This line will bring one or two hours of potentially gust winds, occasionally heavy rain and MVFR ceilings and visibilities. VFR conditions are expected until these storms arrive, which will be around 11z for SDF and BWG. If these storms hold together, they will affect LEX around 12 to 13z. After this first round of morning storms, additional thunderstorms development is likely at some point across central and southern Kentucky during the late morning and afternoon hours. Attempting to time development and movement at this point will be fruitless. Will therefore, add VCTS to TAFs for a somewhat extended time for BWG during the late morning and afternoon hours. West southwest winds will pick up by late morning and reach 12 to 15 mph with some gusts up to 25 mph by early afternoon. West winds will diminish to less than 10kt by 00z Wednesday. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........JSD Short Term.....13 Long Term......KJD Aviation.......JSD
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1204 AM EDT TUE JUL 8 2014 .SYNOPSIS... UNSETTLED CONDITIONS WILL PERSIST ACROSS THE REGION THROUGH THURSDAY. && .NEAR TERM /THROUGH TUESDAY/... MDNGT UPDATE: WE XTNDED THE RISK OF ISOLD TSTMS A LITTLE LATER INTO THE ERLY MORN WED BASED ON PROJECTED FCST SOUNDINGS OF ELEVATED CAPE MOVG EWRD FROM QB PROV BETWEEN 12-30KFT ABV GROUND LVL TIL ABOUT 12-14Z...AT WHICH POINT...THESE ELEVATED CAPES MOVE INTO NB PROV. THIS APPEARS TO BACKED BY THE HRRR MODEL WHICH SHOWS ANOTHER ROUND OF ISOLD TO SCT SHWRS/ISOLD TSTMS VERY LATE TNGT INTO ERLY WED MORN ACROSS THE N. THIS TYPE OF SOUNDING SUPPORTS ACCAS TYPE OF CLDNSS IN SUPPORT OF THIS SHWR ACTIVITY. OTHERWISE...FCST HRLY TEMPS AND OVRNGT LOWS TNGT WERE MODIFIED SLIGHTLY BASED ON TRENDS FROM 11 PM OBS. PREV DISCUSSION: A DISTURBANCE WILL CROSS THE REGION EARLY TONIGHT WITH SHOWERS. SHOWER CHANCES WILL THEN DECREASE OVERNIGHT IN THE WAKE OF THE DISTURBANCE...LEAVING PARTLY/MOSTLY CLOUDY SKIES ACROSS THE FORECAST AREA. GENERALLY EXPECT PARTLY SUNNY SKIES ACROSS THE REGION TUESDAY...WITH AN ISOLATED/SCATTERED AFTERNOON SHOWER OR THUNDERSTORM POSSIBLE. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE LOWER TO MID 60S ACROSS THE FORECAST AREA. HIGH TEMPERATURES TUESDAY WILL GENERALLY RANGE FROM THE LOWER TO MID 80S ACROSS THE FORECAST AREA...WITH COOLER READINGS ALONG THE IMMEDIATE DOWNEAST COAST. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... THE SHORT TERM PERIOD STARTS OUT UNSETTLED WITH AN UPPER LEVEL SHORTWAVE AND SFC COLD FRONT MOVING ACROSS NEW ENGLAND. THESE TWO FEATURES WILL SPAWN SCTD SHOWERS AND TSTMS ACROSS PARTS OF NEW ENGLAND...WITH THE BEST CHANCE OF PRECIP EXPECTED WED NIGHT FROM THE CROWN OF MAINE SWRD ACROSS WRN MAINE INTO NRN NEW HAMPSHIRE AND VERMONT. SUBSIDENCE AND DRIER AIR WILL MOVE OVER MUCH OF MAINE ON THURSDAY...WITH THE MAIN AREA OF PRECIP SHIFTING EWRD ACROSS NB/NS AND THE ATLANTIC OCEAN. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... UPPER TROUGH WILL SWING THROUGH THE REGION AS SYSTEM CONTINUES TO PROGRESS EAST OF THE REGION THURSDAY NIGHT. THIS WILL ALLOW FOR SURFACE HIGH PRESSURE TO BEGIN BUILDING EAST ACROSS THE REGION THURSDAY NIGHT INTO FRIDAY. THIS WILL ALSO BRING MOSTLY SUNNY SKIES FOR FRIDAY AS UPPER LEVEL FLOW FLATTENS. THIS IS EXPECTED TO CONTINUE INTO FRIDAY NIGHT WITH INCREASING CLOUDS LATER SATURDAY INTO SATURDAY NIGHT AS SURFACE HIGH BREAKS DOWN. ONCE THIS HIGH BREAKS DOWN WE WILL INCREASE SW FLOW THEREFORE INCREASING MOISTURE ACROSS THE REGION. CONSEQUENTLY THIS WILL BRING INCREASED CHANCES OF SHOWERS AND AFTERNOON THUNDERSTORMS ACROSS THE REGION WITH GOOD UPPER LEVEL DIFFLUENCE ALOFT GOING INTO SUNDAY. THESE SHOWER AND THUNDERSTORM CHANCES WILL CONTINUE AS FRONTAL BOUNDARY APPROACHES THE REGION AS WE GO INTO MONDAY AFTERNOON. TEMPERATURES THROUGH THE PERIOD ARE EXPECTED TO BE NEAR TO A BIT ABOVE NORMAL. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... NEAR TERM: GENERALLY VFR/MVFR CONDITIONS WILL OCCUR ACROSS THE REGION EARLY THIS EVENING...WITH CONDITIONS LOWERING TO IFR/LIFR LEVELS LATER THIS EVENING. MVFR/IFR CONDITIONS ARE EXPECTED ACROSS THE REGION EARLY TUESDAY...IMPROVING TO VFR LEVELS TUESDAY AFTERNOON. HOWEVER...VARIABLE CONDITIONS COULD OCCUR IN THE VICINITY OF ANY SHOWERS OR THUNDERSTORMS TUESDAY AFTERNOON. SHORT TERM: AREAS OF MVFR CONDITIONS WILL AFFECT NRN AND WRN MAINE WEDNESDAY NIGHT IN ASSOCIATION WITH SHORTWAVE AND FRONT MOVING ACROSS NEW ENGLAND. OTHERWISE...PREVAILING CONDITIONS SHOULD BE VFR. && .MARINE... NEAR TERM: A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IS IN EFFECT FOR MUCH OF THE WATERS...WITH THE EXCEPTION OF THE INTRACOASTAL WATERS...TONIGHT THROUGH TUESDAY AFTERNOON. VISIBILITIES COULD BE REDUCED IN SHOWERS AND PATCHY FOG TONIGHT. SHORT TERM: MADE LITTLE TO NO CHANGES TO GOING FORECAST FOR WINDS AND WAVES OVER THE COASTAL WATER. SRLY WINDS AHEAD OF THE FRONT WILL INCREASE TO 10 TO 15 KTS ON WEDNESDAY...THEN BECOME WEST AFTER THE FRONT MOVES THROUGH ON THURSDAY. DUE TO COLD WATER RESULTING IN A SHALLOW INVERSION...WINDS AND AS A RESULT WAVE HEIGHTS WILL BE LESS THAN THE WAVE MODELS ARE FORECASTING. HOWEVER BORDERLINE WAVE/WIND CONDITIONS DURING THIS TIME FRAME MAY NECESSITATE A SMALL CRAFT ADVISORY FOR OUR COASTAL WATERS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EDT TUESDAY FOR ANZ050-051. && $$ NEAR TERM...VJN SHORT TERM...RB LONG TERM...JORDAN AVIATION...VJN/RB MARINE...VJN/RB
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
122 AM EDT TUE JUL 8 2014 .SYNOPSIS... HIGH PRESSURE BECOMES ANCHORED OFF THE SOUTHEAST COAST TONIGHT THROUGH WEDNESDAY. A WEAK FRONTAL BOUNDARY APPROACHES FROM THE NORTHWEST LATER WEDNESDAY AND LINGERS OVER THE MID ATLANTIC REGION INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... LATEST WX ANALYSIS FEATURES SFC HIGH PRESSURE CENTERED WELL OFFSHORE...RIDGING BACK TOWARDS THE SOUTHEAST COAST. TO THE NW, LOW PRESSURE WAS ANALYZED OVER ONTARIO, WITH THE SFC COLD FRONT SNAKING SWWD BACK INTO THE MID MO VLY AND CENTRAL PLAINS. ALOFT, EARLY EVENING GOES WV IMAGERY SHOWS A STRONG SHORTWAVE EMBEDDED IN BROAD UPPER LEVEL TROUGH OVER AND N OF THE GREAT LAKES/UPPER MIDWEST. MEANWHILE, UPPER RIDGING PERSISTS IN THE SUBTROPICAL WESTERN ATLANTIC. NO MAJOR CHANGES NEEDED THIS EVENING. SCT TO BKN CU OF LATE THIS AFTN HAS LARGELY DISSIPATED AS EXPECTED EARLY THIS EVENING. GENERALLY CLEAR/MOSTLY CLEAR AND MILD OVERNIGHT WITH EARLY MORNING LOW TEMPERATURES TO AVERAGE IN THE LOW/MID 70S. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/... THE UPPER RIDGE/SURFACE HIGH PRESSURE HOLD STRONG OFF THE COAST TUESDAY...WITH THE FRONT REMAINING WELL NW OF THE LOCAL AREA. THIS WILL RESULT IN DEEP LAYERED SSW FLOW AND HOT TEMPERATURES. HIGHS ARE EXPECTED TO AVERAGE IN THE MID/UPPER 90S...WITH ONLY FEW-SCT AFTERNOON CU. HUMIDITY VALUES WILL REMAIN MODEST AS AFTERNOON DEWPOINTS MIX DOWN INTO THE MID 60S. THIS WILL KEEP HEAT INDICES AOB 100. THERE IS NOT MUCH OF A TRIGGER FOR CONVECTION AND FORECAST SOUNDINGS INDICATE A RATHER PROMINENT SUBSIDENCE INVERSION THROUGH THE DAY. AN ISO TSTM COULD DRIFT OFF THE HIGHER TERRAIN INTO FAR N/NW PORTIONS OF THE AREA TUESDAY EVENING. OTHERWISE...EXPECT ANOTHER WARM NIGHT UNDER A MOSTLY CLEAR TO PARTLY CLOUDY SKY. LOWS SHOULD AVERAGE IN THE LOW/MID 70S. THE COLD FRONT CROSSES THE MOUNTAINS AND SLUMPS INTO THE AREA FROM THE WNW WEDNESDAY. THIS WILL INTERACT WITH THE HOT AND MODERATELY HUMID AIRMASS OVER THE PIEDMONT/COASTAL PLAIN BRINGING A 30-40% CHC OF SHOWERS/TSTMS MAINLY DURING THE AFTERNOON AND EVENING HOURS. AN FEW STRONG WIND GUSTS ARE POSSIBLE AS CONVECTION DEVELOPS OVER A DEEP WELL MIXED BOUNDARY LAYER. HOWEVER...WIDESPREAD SEVERE WEATHER IS NOT EXPECTED. HIGHS SHOULD BE IN THE LOW/MID 90S...AND ONCE AGAIN HUMIDITY LEVELS WILL BE LOW ENOUGH TO KEEP HEAT INDICES AOB 100. THE BOUNDARY LINGERS OVER THE REGION THURSDAY...WITH A 30-40% CHC OF MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS CONTINUING. HIGHS SHOULD DROP BACK INTO THE UPPER 80S TO AROUND 90...AFTER MORNING LOWS IN THE LOW/MID 70S. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... VERY WARM AND RATHER HUMID CONDITIONS WILL DOMINATE THE EXTENDED PERIOD. UPR TROF WILL APPROACH AND PUSH ACRS THE AREA THU NGT INTO SAT...NUDGING ONE FRNTL BOUNDARY EVENTUALLY OFF THE CST. ANOTHER FRONT WILL THEN PUSH INTO THE REGION MON AND MON NGT. WILL HAVE 40 POPS MAINLY OVR ERN/SE AREAS THU NGT INTO FRI...THEN DIMINISHING TO 30 OR 20 POPS FRI AFTN INTO SAT. INCREASE POPS TO 30 PERCENT EVERYWHERE FOR SUN AFTN/EVENG...DUE TO HIGHER TEMPS AND A LEE TROF SETTING UP OVR THE REGION. WILL HAVE 30 POPS AGAIN FOR MON AFTN THRU MON NGT...AS FRNTL BOUNDARY PUSHES INTO THE AREA. MIN TEMPS WILL RANGE FM THE MID 60S TO LWR 70S THRU THE PERIOD...WITH MAX TEMPS RANGING FM THE MID 80S TO LWR 90S. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS EXPECTED THROUGH FCST PERIOD. CONCERN TODAY WILL BE THE GUSTY SW WINDS (15-25 KTS) AS A RESPECTABLE PRESSURE GRADIENT FOR JULY PROGGED AS SFC TROF REMAINS NRLY STNRY ACROSS THE PIEDMONT. ISOLATED CONVECTION PSBL MAINLY NW OF A RIC-SBY LINE BUT CHC NOT HIG ENUF TO INCLUDE IN FCST ATTM. OUTLOOK...A COLD FRONT APPROACHES FROM THE NW WEDNESDAY AND SETTLES OVER THE REGION THURSDAY AND FRIDAY. THERE WILL BE A CHANCE FOR AFTN AND EVENING TSTMS WEDNESDAY THROUGH FRIDAY. A BIT DRIER PATTERN IS INDICATED SATURDAY. && .MARINE... 7 PM UPDATE... A SCA IS IN EFFECT THROUGH 10 AM TUESDAY FOR THE BAY AND THE LOWER JAMES RIVER. SW WINDS WILL OCCASIONALLY GUST TO AROUND 20 KNOTS OVER THESE WATERS. THE RAP AND HRRR AGAIN HOLD ONTO SUSTAINED WINDS OF NEAR 20 KNOTS THROUGH 12Z THEN DROP THEM OFF. THIS IS VERY SIMILAR TO MONDAY MORNING BUT NOT NECESSARILY A SIMILAR PATTERN. WINDS OVER LAND WERE GUSTY EARLY MONDAY EVENING AND SOME OF THESE GUSTS HAVE SPREAD INTO THE WRN PORTIONS OF THE WATERS. WITH THE HI RES MODELS INDICATING SCA CONDITIONS ONCE AGAIN...IT SEEMED PRUDENT TO ISSUE THE SCA. WILL ASSESS THE NEED FOR SCA IN CURRITUCK SOUND LATER THIS EVENING. FROM PREVIOUS DISCUSSION... SSW WINDS 10 TO 20 KT WILL CONTINUE TO DOMINATE THE WTRS TNGT THRU WED WITH SEAS 2 TO 4 FT OVR THE CSTL WTRS...ALTHO SEAS COULD REACH 5 OR 6 FT OVR THE NRN CSTL WTRS TUE NGT INTO WED. WAVES WILL RANGE FM 1 TO 3 FT. A COLD FRNT WILL SLOWLY DROP SE ACRS THE WTRS WED EVENG THRU FRI. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK FROM 8 AM EDT THIS MORNING THROUGH THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK FROM 8 AM EDT THIS MORNING THROUGH THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK FROM 8 AM EDT THIS MORNING THROUGH THIS EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ630>632-634-638. && $$ SYNOPSIS...AJZ/ALB NEAR TERM...AJZ/MAM SHORT TERM...AJZ/ALB LONG TERM...TMG AVIATION...MPR MARINE...TMG/LSA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1206 AM EDT TUE JUL 8 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 413 PM EDT MON JUL 7 2014 WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW BETWEEN A RIDGE OVER THE WRN CONUS AND SRN PLAINS AND A TROUGH THROUGH NRN MANITOBA INTO NRN ONTARIO. ONE WEAK SHRTWV IN CNTRL MN SUPORTED SCT SHRA/TSRA FROM ERN MN INTO CNTRL WI...WHILE A MORE PROMINENT SHRTWV WAS LOCATED OVER WRN NORTH DAKOTA. AT THE SFC...GUSTY WNW WINDS PREVAILED WITH A 995 MB LOW PRES OVER NRN ONTARIO(NEAR CYTS). TONIGHT...THE HIGHER RES MODELS HAVE TRENDED FARTHER SOUTH WITH THE THE HEAVIER PCPN AND ASSOCIATED PCPN CHANCES WHERE THE GREATER FORCING(700-300 MB QVECTOR CONV AND UPPER LEVEL DIV) AND INSTABILITY IS LOCATED AS THE ND SHRTWV MOVES TOWARD THE AREA. NEVERTHELESS...NMS SHRA ARE EXPECTED TO CLOSER TO THE WI BORDER BY LATE EVENING AND OVERNIGHT WITH CHANCE POPS FARTHER NORTH TOWARD LAKE SUPERIOR EAST OF THE KEWEENAW. THUNDER WAS ALSO ONLY INDCLUDED ACROSS THE FAR SOUTH. TUESDAY...EXPECT THAT HIGHER PCPN CHANCES IN THE MORNING TO DIMINISH BY AFTERNOON AS THE SHRTWV MOVES OFF TO THE EAST. ADDITIONAL PCPN AMOUNTS SHOULD AGAIN BE GREATEST OVER SRN CWA. THE COMBINATION OF THICKER CLOUDS AND NRLY LOW LEVEL FLOW WILL KEEP TEMPS WELL BELOW NORMAL WITH UPPER 50S TO MID 60S NORTH TO THE MID 60S SOUTH. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 416 PM EDT MON JUL 7 2014 AN UPPER TROUGH CURRENTLY OVER THE UPPER GREAT LAKES REGION WILL BE REINFORCED TONIGHT AND TOMORROW BY A SHORTWAVE (CURRENTLY NEAR LAKE WINNIPEG) THAT WILL DROP SOUTHEAST THROUGH THE AREA. THIS FIRST WAVE WILL SHIFT OUT OF THE AREA ON TUESDAY...BUT ANOTHER WAVE WILL BE DROPPING SOUTHEAST FROM LAKE WINNIPEG AT 00Z WEDNESDAY AND ACROSS THE CWA LATE TUESDAY EVENING THROUGH WEDNESDAY MORNING. THERE ARE SOME DIFFERENCES IN THE MODELS WITH THE TRACK OF THE SHORTWAVE...WITH THE GENERAL CONSENSUS OF IT MOVING ACROSS THE SOUTHWEST HALF OF THE CWA. WILL TRANSITION CHANCE POPS ACROSS THE WESTERN TWO THIRDS OF THE AREA FROM NORTHWEST TO SOUTHEAST DURING THAT TIME. THERE IS LIMITED CAPE...BUT THE STRENGTH OF THE SHORTWAVE AND POCKET OF STEEPER LAPSE RATES (700-500MB AT 6-6.5C/KM) THOUGHT THERE COULD BE AN ISOLATED RUMBLE OF THUNDER AND HAVE SHOWN SLIGHT CHANCE OVER THE SOUTHWEST HALF OF THE CWA AS IT SWEEPS THROUGH. BEHIND THIS WAVE...HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES REGION FOR WEDNESDAY AFTERNOON AND REMAIN THROUGH THURSDAY NIGHT. 850MB TEMPS ARE COOLING TO 6-7C ON WEDNESDAY...AND COMBINED WITH MORNING CLOUDS/RAIN AND NORTHERLY WINDS OFF LAKE SUPERIOR...IT WILL LEAD TO A BELOW NORMAL DAY ACROSS THE U.P. EXPECT MOST LOCATIONS TO SEE HIGHS IN THE 60S...WITH COOLER VALUES EAST NEAR LAKE SUPERIOR AND MAYBE REACHING 70 NEAR THE WISCONSIN BORDER WITH SOME AFTERNOON SUNSHINE. CLEAR SKIES...LIGHT WINDS...AND PWATS AROUND 45 PERCENT OF NORMAL UNDER THE HIGH MOVING THROUGH SHOULD LEAD TO A COOL NIGHT OVER SOME OF THE INTERIOR COLD SPOTS WEDNESDAY NIGHT. HAVE LOWERED INTERIOR TEMPERATURES TOWARDS THE LOW END OF GUIDANCE AND HAVE A FEW LOCATIONS RIGHT AROUND 40. EXPECT TEMPERATURES TO TREND BACK TOWARDS NORMAL ON THURSDAY WITH ABUNDANT SUNSHINE AND INTO THE LOW-MID 70S OVER INTERIOR LOCATIONS. WITH LAKE BREEZES EXPECTED ON THURSDAY...WILL SEE COOLER TEMPERATURES OVER THE EAST NEAR LAKE SUPERIOR/MICHIGAN. THE NORTHWEST FLOW ALOFT WILL GIVE WAY DURING THIS PERIOD...AS THE NEXT WAVE ROUNDING THE UPPER RIDGE OVER THE PACIFIC NORTHWEST AND AFFECTS THE AREA FOR FRIDAY AND FRIDAY NIGHT. THAT NEXT WAVE WILL PUSH A LOW EAST ACROSS NORTHERN MANITOBA...WITH A COLD FRONT STRETCHING SOUTH INTO THE UPPER MISSISSIPPI VALLEY FRIDAY MORNING. A SHORTWAVE SLIDING EAST OUT OF THE DAKOTAS FRIDAY MORNING WILL LEAD TO SHOWERS/THUNDERSTORMS DEVELOPING AHEAD OF THE COLD FRONT AND MOVING FROM WEST TO EAST THROUGH THE CWA FRIDAY INTO FRIDAY NIGHT. WILL SHOW INCREASING CHANCES DURING THAT PERIOD AND THEN DIMINISHING LATE IN THE NIGHT AND INTO THE NEXT MORNING. DIURNAL HEATING OUT AHEAD OF THE FRONT ON FRIDAY AFTERNOON SHOULD LEAD TO SOME THUNDERSTORMS OVER THE AREA FRIDAY AFTERNOON/EVENING. DETERMINISTIC MODELS VARY BEHIND THIS WAVE/FRONT WITH THE HANDLING OF THE UPPER TROUGH...BUT THE LASTEST TREND IS FOR IT TO AMPLIFY OVER THE UPPER GREAT LAKES FOR THE SECOND HALF OF THE WEEKEND AND INTO NEXT WEEK. THIS WOULD LEAD TO A COOLER THAN NORMAL PERIOD THROUGH AT LEAST THE FIRST HALF OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1206 AM EDT TUE JUL 8 2014 VFR CONDITIONS WILL CONTINUE AT ALL SITES INTO EARLY MORNING. THE NEXT DISTURBANCE WILL MOVE INTO THE REGION AND BRING A CHANCE OF SHOWERS OVERNIGHT. AS WINDS SHIFT NE LATE TONIGHT LOOK FOR MVFR CLOUDS TO DEVELOP AT KIWD DROPPING TO IFR TUE MORNING BEFORE DRIER AIR MOVES IN AND VFR CONDITIONS RETURN BY MID TUE AFTERNOON. RAIN WILL AGAIN ARRIVE IN THE EVENING THERE WITH MVFR CONDITIONS EXPECTED TO REDEVELOP AGAIN. CIGS WILL GO TO LIFR IN THE RAIN OVERNIGHT AT SAW WITH UPSLOPE NORTHEAST FLOW OFF OF LAKE SUPERIOR LASTING THROUGH THE MORNING BEFORE DRIER AIR AND IMPROVING CONDITIONS ARRIVE. AT KCMX...MVFR CONDITIONS WILL DEVELOP BY TUE MORNING BEFORE DRIER AIR ARRIVES TUE AFTERNOON FOR VFR CONDITIONS THROUGH THE REST OF THE PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 413 PM EDT MON JUL 7 2014 WINDS ARE EXPECTED TO BE BELOW 25KTS THROUGH THE PERIOD OUTSIDE OF ANY STRONG SHOWERS OR THUNDERSTORMS. LOW PRESSURE NE OF LAKE SUPERIOR WILL LIFT TOWARD JAMES BAY THIS EVENING AS A WEAK LOW PRESSURE TROUGH MOVES ACROSS LAKE SUPERIOR AND UPPER MI TONIGHT. ANOTHER WEAK LOW PRESSURE TROUGH ACROSS ONTARIO TUESDAY WILL SINK ACROSS LAKE SUPERIOR TUESDAY NIGHT INTO EARLY WEDNESDAY...BEFORE STRONGER HIGH PRESSURE SETTLES ACROSS THE UPPER GREAT LAKES WEDNESDAY NIGHT THROUGH AT LEAST THURSDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...KF MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
342 AM CDT TUE JUL 8 2014 .SYNOPSIS... ISSUED AT 301 AM CDT TUE JUL 8 2014 MID LVL LOW OVER HUDSON BAY EARLY THIS MORNING WITH A FAIRLY LARGE AREA OF CYCLONIC CIRCULATION ASSOCIATED WITH ITS PRESENCE. WITHIN THE CIRCULATION MULTIPLE SHORTWAVE TROFS CONTINUE TO MOVE WITHIN THE FLOW. LATEST WV IMAGERY SHOWS AT LEAST 3 SHORTWAVES EVIDENT ACROSS WRN ONTARIO AND MANITOBA. SCTD SHOWERS CONTINUE TO DEVELOP/OCCUR OVER ERN THIRD OF CWA DESPITE LOSS OF EARLIER INSTABILITY. A WELL DEFINED SHEAR AXIS/WIND SHIFT IS INDICATED IN THE 925 FLOW FROM ERN LAKE COUNTY IN THE ARROWHEAD CURVING THROUGH THE APOSTLES. THIS IS RELATED TO A BACKDOOR FRONTAL BDRY REPRESENTED IN THE LOW LVL THERMAL FIELDS. HEAVY PRECIP...RADAR ESTIMATES AND GROUND REPORT OVER 2 INCHES IN IRON COUNTY...HAS MOVED OUT OF THE CWA. CALLS TO LOCAL LAW OFFICIALS IN THE AREA AND CHECK ON A FEW RIVERS INDICATES THREAT APPEARS TO BE OVER. HAVE LET FLS EXPIRE AT 3AM. && .SHORT TERM...(TODAY THROUGH TOMORROW) ISSUED AT 301 AM CDT TUE JUL 8 2014 TODAY...BACK DOOR FRONTAL BDRY WILL MOVE INTO THE TWIN PORTS EARLY IN THE MORNING AND WEAKEN BY MIDDAY. DISTURBING DIFFERENCES BETWEEN MDLS WITH REGARD TO TIME/HEIGHT XSEC OF MOISTURE WITH EC SUGGESTING WHATEVER LOW CLOUD IS EVIDENT IN MORNING WILL LIFT WITH DAYTIME WARMING. NAM12/RAP SUGGEST A LOW OVERCAST MAY DWELL INTO AFTERNOON AROUND LAKE SUPERIOR. WILL GO PESSIMISTIC IN MORNING AND IMPROVING TREND IN AFTN. PESKY UPPER AIR PATTERN MAKES PLACEMENT OF HIGHEST POPS A BIT CHALLENGING TODAY SO ADDITIONAL UPDATES MAY BE NECESSARY. WITH A LACK OF A LOW LVL FOCUS FOR BDRY LYR CONVERGENCE THE POPS ARE BASED ON A GUESSTIMATE OF THE AXIS OF GREATEST INSTABILITY. USING RUC13 THIS APPEARS TO LINE UP FROM THE IRON RANGE TO NW WISC DURING THE MAJORITY OF THE DIURNAL WARMING. HI RES SIM REFL PRODUCTS SHOW NATURE OF SYNOPTIC PATTERN WITH LARGE INCREASE IN INSTABILITY ECHOES LATE MORNING THROUGH EARLY EVENING OVER MOST OF CWA. SIGNIFICANT DECREASE IN 925 TEMPS COMPARED TO YESTERDAY SO MAX TEMPS WILL BE ABOUT 5 TO 10 DEGREES COOLER IN MANY AREAS. TONIGHT/TOMORROW...MID LVL TROF OVER ONTARIO AND THE GT LAKES WILL SLOWLY SHIFT EAST. LOW LVL CYCLONIC CIRCULATION WILL BE REPLACED BY ANTICYCLONIC FLOW AS A WEAK SFC HIGH MOVES ACROSS UPPER MIDWEST WEDNESDAY. HAVE INSERTED VERY LOW POPS OVER SERN PART OF CWA IN THE AFTN WITH AXIS OF FCST INSTABILITY....ALBEIT MEAGER...IN THE VICINITY. OTHERWISE A PLEASANT DAY WITH NEAR TYPICAL TEMPS. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 301 AM CDT TUE JUL 8 2014 THE AREA OF HIGH PRESSURE WILL CONTINUE TO DOMINATE THE FORECAST AREA THROUGH THURSDAY AFTERNOON. THE TEMPERATURES WILL BE AT OR A LITTLE BELOW THEIR NORMAL VALUES. A WEAK SHORTWAVE WILL MOVE THROUGH CENTRAL MINNESOTA THURSDAY AFTERNOON AND MAY BRING A SHOWER OR THUNDERSTORMS TO SOUTHERN CASS AND CROW WING COUNTIES BUT THESE POPS WILL BE LOW. A COLD FRONT WILL APPROACH THE REGION THURSDAY NIGHT AND MOVE THROUGH THE FORECAST AREA ON FRIDAY AND FRIDAY NIGHT. WITH THE INCREASED MOISTURE AHEAD OF THE FRONT...THERE WILL BE A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. THE GFS IS FASTER THAN THE ECMWF WITH HIS FEATURE. BOTH MODELS NOW AGREE THAT SATURDAY WILL BE DRY WITH THE BULK OF THE PRECIP SOUTH OF THE FORECAST AREA. THE GFS HAS A FRONT MOVING THROUGH THE REGION ON SUNDAY WITH THE ECMWF A LITTLE SLOWER WITH THE FEATURE. WILL GO WITH A COMPROMISE AT THE MOMENT BUT WILL REFINE AS THE WEEKEND GETS CLOSER. HIGH PRESSURE BUILDS IN FOR THE BEGINNING OF THE WORK WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 709 PM CDT MON JUL 7 2014 SCATTERED STRONG THUNDERSTORMS WILL CONTINUE TO BE FOUND ACROSS THE NORTHLAND OVERNIGHT...BUT THE TREND WILL BE TOWARD MORE SHOWER ACTIVITY AS THE NIGHT WEARS ON. VFR CONDITIONS WILL BE THE RULE...BUT OCCASIONALLY THERE WILL BE SOME MVFR/IFR CIGS/VSBYS DUE TO THE STRONGER SHOWERS AND THUNDERSTORMS. && .PRELIMINARY POINT TEMPS/POPS... DLH 69 51 72 52 / 40 20 0 0 INL 67 48 72 50 / 40 20 0 0 BRD 74 53 76 55 / 20 10 0 0 HYR 71 49 74 49 / 50 20 10 0 ASX 66 49 70 49 / 40 30 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SYNOPSIS...CANNON SHORT TERM...CANNON LONG TERM...STEWART AVIATION...DAP
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
445 AM CDT Tue Jul 8 2014 .SHORT TERM: (Through Late This Afternoon) Issued at 353 AM CDT Tue Jul 8 2014 The weakening MCS moving southeastward through east central and southeast MO as well as southwest IL should shift southeast of our forecast area later this morning. The cold front now across northwest MO will move southeastward through the forecast area today. Although we could not rule out redevelopment of convection this afternoon along and just ahead of this cold front, it appears that the effective low level boundary will be the outflow from this mornings MCS which will be southeast of our forecast area this afternoon. The latest HRRR develops convection late this afternoon south and southeast of the forecast area. Even the operational models afternoon qpf is confined to the extreme southern or southeastern portion of our forecast area. For now will include chance pops across southeast MO and southwest IL, south and east of STL for this afternoon. High temperatures today will be slightly cooler than yesterday due to at least weak cold air advection behind the cold front and gradually lowering 850 mb temperatures. GKS .LONG TERM: (Tonight through Monday) Issued at 445 AM CDT Tue Jul 8 2014 It appears that the showers/storms will be south or southeast of our forecast area by this evening as a surface ridge builds southeastward into our area behind the cold front. This will bring cooler and less humid air into the region tonight and Wednesday. Will have at least slightly below normal temperatures for tonight through Wednesday night. The next chance of convection will occur over the northern portion of our forecast area late Thursday night and Friday morning due to strong low level warm air advection and moisture convergence on the nose of a southwesterly low level jet ahead of a northwest flow shortwave. The models were also depicting relatively strong upper level divergence ahead of this shortwave. A warming trend will also begin Thursday night and Friday along with increasing humidities due to southerly return flow on the backside of the surface ridge as it shifts east of the region. An upper level ridge will try to build northeastward into southwestern MO Friday night and Saturday. Any potential for convection should be confined to the northern and eastern portion of the forecast area as shortwaves move east southeastward over the upper level ridge. Temperatures should be quite warm this weekend, especially across central and southeast MO. There will be the chance of showers/storms across the entire area as we head into the next work week as the models deepen an upper level trough over the Great Lakes region and send a cold front southeastward through our forecast area Sunday night and Monday. The ECMWF model is stronger or deeper with this upper level trough compared to the GFS model and is also slower moving the front through our forecast area and has more qpf associated with this front. Due to the model inconsistencies will just include chance pops for most of the area on Monday along with cooler high temperatures. GKS && .AVIATION: (For the 06z TAFs through 06z Tuesday Night) Issued at 1241 AM CDT Tue Jul 8 2014 Squall line is marching east-southeast through the area with a large area of stratoform rain behind it. Primary concern will be wind gusts in excess of 50kts as the line moves through, and second brief IFR flight conditions in heavy rain. CIGs/VSBYs improve pretty rapidly to high end MVFR and VFR behind the line in the lighter rain. Expect this light rain and thunder to continue for several hours behind the line. Flight conditions may briefly dip into MVFR in this area, but believe VFR flight conditions will prevail. Expect rain to end from northwest to southeast across the area through 12Z Tuesday morning. Specifics for KSTL: Squall line is marching east-southeast through the area with a large area of stratoform rain behind it. Primary concern will be wind gusts in excess of 50kts as the line moves through, and second brief IFR flight conditions in heavy rain. CIGs/VSBYs improve pretty rapidly to high end MVFR and VFR behind the line in the lighter rain. Expect this light rain and thunder to continue for several hours behind the line. Flight conditions may briefly dip into MVFR in this area, but believe VFR flight conditions will prevail. Expect rain to end from northwest to southeast...probably ending between 10-12Z at Lambert. Carney && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
354 AM CDT Tue Jul 8 2014 .SHORT TERM: (Through Late This Afternoon) Issued at 353 AM CDT Tue Jul 8 2014 The weakening MCS moving southeastward through east central and southeast MO as well as southwest IL should shift southeast of our forecast area later this morning. The cold front now across northwest MO will move southeastward through the forecast area today. Although we could not rule out redevelopment of convection this afternoon along and just ahead of this cold front, it appears that the effective low level boundary will be the outflow from this mornings MCS which will be southeast of our forecast area this afternoon. The latest HRRR develops convection late this afternoon south and southeast of the forecast area. Even the operational models afternoon qpf is confined to the extreme southern or southeastern portion of our forecast area. For now will include chance pops across southeast MO and southwest IL, south and east of STL for this afternoon. High temperatures today will be slightly cooler than yesterday due to at least weak cold air advection behind the cold front and gradually lowering 850 mb temperatures. GKS .LONG TERM: (Tuesday through Next Monday) Issued at 341 PM CDT Mon Jul 7 2014 (Tuesday through Thursday) On Tuesday, the front will be moving south and out of the CWA about the time that thunderstorms will be initiating during the early-mid afternoon hours. There is still some potential that one or two of these storms could become severe before they move out of the CWA during the late afternoon hours. The front will then move well south of the area Wednesday into Thursday as the flow becomes northwesterly aloft. The area will lie under mainly subsidence during this period, so have kept these two days dry. 850 mb temperatures will be between 12-18C promising below normal temperatures. (Friday through next Monday) Warm front is still on track to move through the area on Friday and Saturday causing temperatures to climb back closer to normal. The front will keep scattered thunderstorms in the forecast. 850 mb temperatures of 18-20C call for temperatures at or just above normal. ECMWF sets up northwesterly flow over the area quicker than the GFS on Saturday and Sunday, so consequently it is trying to bring a cold front through the CWA faster. This solution is faster than in previous runs, so went with the slower idea with a cold front entering the northern part of the CWA on Sunday morning and move it south across the area through Monday. Will continue the chance of thunderstorms into early next week. Britt && .AVIATION: (For the 06z TAFs through 06z Tuesday Night) Issued at 1241 AM CDT Tue Jul 8 2014 Squall line is marching east-southeast through the area with a large area of stratoform rain behind it. Primary concern will be wind gusts in excess of 50kts as the line moves through, and second brief IFR flight conditions in heavy rain. CIGs/VSBYs improve pretty rapidly to high end MVFR and VFR behind the line in the lighter rain. Expect this light rain and thunder to continue for several hours behind the line. Flight conditions may briefly dip into MVFR in this area, but believe VFR flight conditions will prevail. Expect rain to end from northwest to southeast across the area through 12Z Tuesday morning. Specifics for KSTL: Squall line is marching east-southeast through the area with a large area of stratoform rain behind it. Primary concern will be wind gusts in excess of 50kts as the line moves through, and second brief IFR flight conditions in heavy rain. CIGs/VSBYs improve pretty rapidly to high end MVFR and VFR behind the line in the lighter rain. Expect this light rain and thunder to continue for several hours behind the line. Flight conditions may briefly dip into MVFR in this area, but believe VFR flight conditions will prevail. Expect rain to end from northwest to southeast...probably ending between 10-12Z at Lambert. Carney && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
415 AM EDT TUE JUL 8 2014 .SYNOPSIS... UNSETTLED WEATHER CONTINUES THROUGH EARLY WEDNESDAY AS A SERIES OF SYSTEMS PUSH EAST. HIGH PRESSURE BRINGS DRIER AIR TO THE REGION FOR THE END OF THE WEEK. ANOTHER SYSTEM OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... CUT BACK POP CHCS FOR THE EARLY MORNING HOURS AS OVERNIGHT CONVECTION DIED OFF RAPIDLY WITH THE LOSS OF DAYTIME HEATING. NEAR TERM HI-RES MODELS RUC13 AND HRRR ARE IN FAIR AGREEMENT IN TRANSITIONING ANOTHER CONVECTIVE BAND ACROSS THE FORECAST AREA THIS AFTERNOON. MAIN FLY IN THE OINTMENT IS TRANSITION OF DYING MCS OVER WESTERN ILLINOIS THAT SLIDING TO THE EAST-NORTHEAST AND SHOULD ARRIVE IN CENTRAL OH BY AROUND 15Z. EXPECT MAINLY RESIDUAL SHOWERS AT THIS TIME AND BOUNCED POPS BACK INTO CHC CATEGORY FOR SE OH TO ACCOUNT FOR THIS FEATURE. AFOREMENTIONED CONVECTIVE BAND MAY HAVE SOME TROUBLE DEVELOPING IN POST MCS ENVIRONMENT THIS AFTERNOON...BUT ONCE IT GETS GOING...IT SHOULD MAKE A LITTLE MORE HEADWAY INTO THE CWA AS COMPARED TO PREVIOUS BAND FROM YESTERDAY. LONGWAVE TROUGH OVER THE EASTERN US UNDERGOING AMPLIFICATION... WITH 5H FALLS OVER RLX AREA..AND MID LEVEL FLOW BECOMING MORE CYCLONIC. EXPECT A BETTER CHANCE FOR SVR STORMS TODAY UNDER A MODERATELY UNSTABLE ATMOSPHERE AND BETTER SHEAR ENVIRONMENT. MAIN THREAT WILL BE GUSTY WINDS WITH LINE OF STORMS...AND SOME BOWING LINE SEGMENTS. STORMS WILL ALSO BE EFFICIENT PRECIP PRODUCERS WITH PWATS RUNNING 1.5 TO 2.0 INCHES LATER THIS AFTERNOON. KEPT MENTION OF LOCALLY HEAVY DOWNPOURS. WITH THE RECENT DRY CONDITIONS DO NOT SEE WIDESPREAD WATER PROBLEMS. HOWEVER...HEAVY DOWNPOURS COULD CAUSE LOCAL WATER PROBLEMS IF ANY REPETITIVE SHOWERS OCCUR. USED A BLEND OF BIAS CORRECTED DATA WITH PREVIOUS OFFICIAL FORECAST FOR TEMPS WHICH YIELDED A MINOR TWEAK TO THE TEMP FIELDS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... NAM/GFS/ECMWF/CMC MODELS IN AGREEMENT IN THEIR QPF FIELDS PUSHING LAST RAIN SHOWERS OR THUNDERSTORMS TO THE EASTERN MOUNTAINS... MAINLY ACROSS THE SOUTH EARLY WEDNESDAY MORNING. THIS PCPN ACTIVITY IS ASSOCIATED WITH A SECOND COLD FRONT ENHANCED BY A H5 VORTICITY MAXIMA SINKING SOUTHEAST ACROSS THE AREA. BUFKIT SOUNDINGS INDICATE VERY DRY AIR ALOFT BEHIND THIS FRONT. YET ANOTHER H5 VORTICITY MAXIMA MOVES FROM THE NORTHWEST REACHING OUR EXTREME SOUTHEAST COUNTIES WEDNESDAY AFTERNOON. THEREFORE...DECIDED TO KEEP CHANCE POPS UNTIL THEN BEFORE ENDING ALL BY 00Z THURSDAY. TEMPERATURES WILL DEPEND ON THE DURATION OF CLOUD COVER ESPECIALLY WEDNESDAY AND THURSDAY. GENERALLY STAYED IN THE MID 80S LOWLANDS FOR WEDNESDAY...AND FEW DEGREES COOLER THURSDAY AS FLOW TURNS NORTHWEST TO NORTH BY THE AFTERNOON AND EVENING HOURS. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... USED A BLEND OF THE GFS AND ECMWF FOR FRIDAY. THIS LEAVES THE AREA UNDER A HIGH PRESSURE SYSTEM...BUT A BIT OF MOISTURE REMAINS IN THE NORTHERN MOUNTAINS....SO CAN NOT RULE OUT A THUNDERSTORM. FOR SATURDAY THROUGH MONDAY...SWITCHED TO A BLEND OF THE GFS/GEFS ENSEMBLE MEAN AND ECMWF ENSEMBLE MEAN. THIS BRINGS A SYSTEM INTO THE CENTRAL APPALACHIANS OVER THE WEEKEND...LINGERING INTO MONDAY. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... CONVECTION DYING OFF ACROSS CENTRAL AND NORTHERN WV...AND LATEST RADAR TRENDS KEEPS MOST OF THE ACTIVITY AWAY FROM TAF SITES. VFR EXPECTED FOR THE REMAINING OVERNIGHT HOURS. CONVECTIVE ACTIVITY INCREASES AGAIN FROM THE WEST AFTER 16Z. EXPECT GUSTY WINDS TO ACCOMPANY CONVECTION...ESPECIALLY AFTER 20Z AS NORTH-SOUTH BAND TRAVERSES ACROSS THE FORECAST AREA. EXPECT AT LEAST MVFR CONDITIONS WITH GUSTY WINDS AS BAND PASSES. LOCAL IFR CONDITIONS CAN BE EXPECTED INVOF HEAVIER PRECIPITATION CORES. STORM COVERAGE SHOULD GRADUALLY DECREASE IN COVERAGE ACROSS THE FAR NORTH...SOUTHEAST OHIO...TOWARDS END OF TAF PERIOD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: MORE WIDESPREAD IFR CONDITIONS DUE TO CONVECTION TUESDAY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE TUE 07/08/14 UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H M M M BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H M H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z WEDNESDAY... LOCAL IFR IN SHOWERS AND THUNDERSTORMS THROUGH EARLY WEDNESDAY... WITH LINGERING IFR CIGS POSSIBLE THROUGH LATE WEDNESDAY MORNING PARTICULARLY ACROSS HIGHER TERRAIN. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KMC/ARJ NEAR TERM...KMC SHORT TERM...ARJ LONG TERM...RPY AVIATION...KMC
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
352 AM EDT TUE JUL 8 2014 .SYNOPSIS... UNSETTLED WEATHER CONTINUES THROUGH EARLY WEDNESDAY AS A SERIES OF SYSTEMS PUSH EAST. HIGH PRESSURE BRINGS DRIER AIR TO THE REGION FOR THE END OF THE WEEK. ANOTHER SYSTEM OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... CUT BACK POP CHCS FOR THE EARLY MORNING HOURS AS OVERNIGHT CONVECTION DIED OFF RAPIDLY WITH THE LOSS OF DAYTIME HEATING. NEAR TERM HI-RES MODELS RUC13 AND HRRR ARE IN FAIR AGREEMENT IN TRANSITIONING ANOTHER CONVECTIVE BAND ACROSS THE FORECAST AREA THIS AFTERNOON. MAIN FLY IN THE OINTMENT IS TRANSITION OF DYING MCS OVER WESTERN ILLINOIS THAT SLIDING TO THE EAST-NORTHEAST AND SHOULD ARRIVE IN CENTRAL OH BY AROUND 15Z. EXPECT MAINLY RESIDUAL SHOWERS AT THIS TIME AND BOUNCED POPS BACK INTO CHC CATEGORY FOR SE OH TO ACCOUNT FOR THIS FEATURE. AFOREMENTIONED CONVECTIVE BAND MAY HAVE SOME TROUBLE DEVELOPING IN POST MCS ENVIRONMENT THIS AFTERNOON...BUT ONCE IT GETS GOING...IT SHOULD MAKE A LITTLE MORE HEADWAY INTO THE CWA AS COMPARED TO PREVIOUS BAND FROM YESTERDAY. LONGWAVE TROUGH OVER THE EASTERN US UNDERGOING AMPLIFICATION... WITH 5H FALLS OVER RLX AREA..AND MID LEVEL FLOW BECOMING MORE CYCLONIC. EXPECT A BETTER CHANCE FOR SVR STORMS TODAY UNDER A MODERATELY UNSTABLE ATMOSPHERE AND BETTER SHEAR ENVIRONMENT. MAIN THREAT WILL BE GUSTY WINDS WITH LINE OF STORMS...AND SOME BOWING LINE SEGMENTS. STORMS WILL ALSO BE EFFICIENT PRECIP PRODUCERS WITH PWATS RUNNING 1.5 TO 2.0 INCHES LATER THIS AFTERNOON. KEPT MENTION OF LOCALLY HEAVY DOWNPOURS. WITH THE RECENT DRY CONDITIONS DO NOT SEE WIDESPREAD WATER PROBLEMS. HOWEVER...HEAVY DOWNPOURS COULD CAUSE LOCAL WATER PROBLEMS IF ANY REPETITIVE SHOWERS OCCUR. USED A BLEND OF BIAS CORRECTED DATA WITH PREVIOUS OFFICIAL FORECAST FOR TEMPS WHICH YIELDED A MINOR TWEAK TO THE TEMP FIELDS. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... MODELS SHOW A COLD FRONT MOVING THROUGH THE REGION TUESDAY NIGHT. WILL INCREASE POPS SOME...ESPECIALLY DURING THE EVENING HOURS. GFS AND ECMWF ARE MUCH FASTER WITH THE COLD FRONT PUSHING THROUGH TUESDAY NIGHT/WEDNESDAY THAN THE NAM. SREF WOULD INDICATE THAT THE NAM IS A SLOW OUTLIER. THEREFORE...WILL LOWER POPS CONSIDERABLY ON WEDNESDAY AS HIGH PRESSURE BRINGS SOME DRIER AIR. GFS INDICATES THAT AN IMPULSE COULD COMBINE WITH SOME WEAK MOISTURE TO FIRE A COUPLE OF STORMS IN THE MOUNTAINS ON THURSDAY. THEREFORE...WILL LEAVE SMALL POPS IN THAT AREA DURING THE AFTERNOON HOURS. && .LONG TERM /FRIDAY THROUGH MONDAY/... USED A BLEND OF THE GFS AND ECMWF FOR FRIDAY. THIS LEAVES THE AREA UNDER A HIGH PRESSURE SYSTEM...BUT A BIT OF MOISTURE REMAINS IN THE NORTHERN MOUNTAINS....SO CAN NOT RULE OUT A THUNDERSTORM. FOR SATURDAY THROUGH MONDAY...SWITCHED TO A BLEND OF THE GFS/GEFS ENSEMBLE MEAN AND ECMWF ENSEMBLE MEAN. THIS BRINGS A SYSTEM INTO THE CENTRAL APPALACHIANS OVER THE WEEKEND...LINGERING INTO MONDAY. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... CONVECTION DYING OFF ACROSS CENTRAL AND NORTHERN WV...AND LATEST RADAR TRENDS KEEPS MOST OF THE ACTIVITY AWAY FROM TAF SITES. VFR EXPECTED FOR THE REMAINING OVERNIGHT HOURS. CONVECTIVE ACTIVITY INCREASES AGAIN FROM THE WEST AFTER 16Z. EXPECT GUSTY WINDS TO ACCOMPANY CONVECTION...ESPECIALLY AFTER 20Z AS NORTH-SOUTH BAND TRAVERSES ACROSS THE FORECAST AREA. EXPECT AT LEAST MVFR CONDITIONS WITH GUSTY WINDS AS BAND PASSES. LOCAL IFR CONDITIONS CAN BE EXPECTED INVOF HEAVIER PRECIPITATION CORES. STORM COVERAGE SHOULD GRADUALLY DECREASE IN COVERAGE ACROSS THE FAR NORTH...SOUTHEAST OHIO...TOWARDS END OF TAF PERIOD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: MORE WIDESPREAD IFR CONDITIONS DUE TO CONVECTION TUESDAY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE TUE 07/08/14 UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H M M M BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H M H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z WEDNESDAY... LOCAL IFR IN SHOWERS AND THUNDERSTORMS THROUGH EARLY WEDNESDAY... WITH LINGERING IFR CIGS POSSIBLE THROUGH LATE WEDNESDAY MORNING PARTICULARLY ACROSS HIGHER TERRAIN. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KMC NEAR TERM...KMC SHORT TERM...RPY LONG TERM...RPY AVIATION...KMC
AREA FORECAST DISCUSSION
NWS TULSA OK
409 AM CDT TUE JUL 8 2014 .DISCUSSION... THE SOUTHWEST PORTION OF A MCS MOVING THROUGH MISSOURI HAD CLIPPED NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS EARLY THIS MORNING. THIS ACTIVITY SHOULD CONTINUE TO PUSH SOUTHEAST AND DISSIPATE OVER THE CWA DURING THE NEXT COUPLE OF HOURS. AN ADDITIONAL LINE OF CONVECTION WAS ACROSS CENTRAL KANSAS...MOVING TO THE SOUTHEAST. WILL LEAVE SLIGHT CHANCE POPS FOR THE MORNING HOURS ACROSS FAR NORTHEAST OKLAHOMA INTO FAR NORTHWEST ARKANSAS. LATEST HRRR AND LOCAL IN-HOUSE MODEL INDICATE THIS LINE TRYING TO FALL APART JUST BEFORE IT GETS INTO THE CWA THIS MORNING. A COLD FRONT CURRENTLY OVER CENTRAL KANSAS WILL MOVE INTO THE CWA TODAY...SHIFTING WINDS OUT OF THE NORTH NORTHEAST. THIS WILL HELP TEMPS ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS BE A LITTLE COOLER COMPARED TO YESTERDAY. CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY FOR THE NORTHERN PART OF THE CWA AS THE FRONT SAGS SOUTHWARD TO NEAR INTERSTATE 40 BY THIS EVENING. AFTERNOON HEATING COULD ALLOW FOR ENOUGH INSTABILITY TO DEVELOP ALONG THE FRONT THAT SOME THUNDERSTORMS COULD BECOME STRONG TO SEVERE WITH LARGE HAIL AND STRONG WINDS BEING THE MAIN HAZARDS. GREATER CHANCES FOR SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS MUCH OF THE CWA TONIGHT INTO WEDNESDAY AS THE FRONT STALLS OUT NEAR THE RED RIVER BY WEDNESDAY MORNING. PERIODS OF HEAVY RAINFALL MAY BE POSSIBLE ALONG WITH A LIMITED SEVERE POTENTIAL. SLIGHTLY COOLER TEMPS WILL AGAIN BE POSSIBLE WEDNESDAY WITH HIGHS IN THE UPPER 80S/LOWER 90S. THE NEARLY STATIONARY FRONTAL BOUNDARY REMAINS OVER THE REGION WEDNESDAY NIGHT INTO THURSDAY AND THEN BEGINS TO LIFT NORTHWARD THURSDAY AS A WARM FRONT. THUS...WILL KEEP AT LEAST SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS GOING THROUGH THURSDAY. A RIDGE OF HIGH PRESSURE BUILDS BACK OVER THE SOUTHERN PLAINS IN THE WAKE OF THE EXITING FRONTAL BOUNDARY AND SHORTWAVE TROF AXIS MOVING ACROSS THE MIDWEST. THIS WILL ALLOW FOR SOUTHERLY WINDS ALONG WITH HOT AND HUMID CONDITIONS TO RETURN TO EASTERN OKLAHOMA AND NORTHWEST ARKANSAS FOR THE WEEKEND. HIGH TEMPS NEAR 100 DEGREES WILL AGAIN BE POSSIBLE FOR PARTS OF EASTERN OKLAHOMA. THESE HOT TEMPS COULD BE SHORT LIVED AS EXTENDED MODEL SOLUTIONS CONTINUE TO SHOW A LOW PRESSURE SYSTEM DROPPING OUT OF CANADA INTO THE GREAT LAKES REGION WITH A COLD FRONT PUSHING ACROSS THE PLAINS FOR THE FIRST PART OF NEXT WEEK. THERE REMAINS TIMING AND STRENGTH DIFFERENCES WITH THIS SYSTEM...THOUGH SOME COOLER TEMPS AND PRECIP CHANCES LOOK POSSIBLE ACROSS THE CWA. && .PRELIMINARY POINT TEMPS/POPS... TUL 93 69 90 71 / 20 30 10 30 FSM 96 72 89 72 / 20 40 30 30 MLC 96 73 91 73 / 10 40 20 30 BVO 90 66 89 69 / 20 20 10 30 FYV 90 66 86 66 / 30 40 10 20 BYV 90 66 86 66 / 30 30 10 20 MKO 95 70 89 71 / 20 30 20 30 MIO 90 65 88 66 / 20 20 10 20 F10 96 71 90 72 / 10 30 20 30 HHW 96 74 93 73 / 10 20 30 30 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...05 LONG TERM....20
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1111 PM CDT MON JUL 7 2014 .UPDATE... MCS WHICH MOVED ACROSS FAR NORTHERN AREAS EARLIER HAS NOW WEAKENED CONSIDERABLY. JUST A FEW SHOWERS IS ALL THAT REMAINS ACROSS OUR PLATEAU. HRRR AND MODEL DATA HANDLED THIS QUITE WELL. A CURRENT LOOK AT THE HRRR DOES SHOW REDEVELOPMENT TOWARD THE 12Z-15Z TIMEFRAME WITH THE ACTIVITY THAT IS CURRENTLY LOCATED OVER MO. WILL GO AHEAD AND LOWER POPS BUT STILL KEEP A 20-30 PERCENT CHANCE GOING ACROSS THE NORTH. DUE TO TIMING...WILL NEED TO KEEP THE POPS ON THE LOW SIDE. TEMPS STILL LOOK TO BE IN GOOD SHAPE BUT WILL ADD A FEW EXTRA CLOUDS ACROSS OUR NORTHERN AREAS. && .PREV DISCUSSION... /ISSUED 732 PM CDT MON JUL 7 2014/ UPDATE...FOR 00Z TAFS. AVIATION... CHANGES IN THE WORKS THIS PERIOD AS UPPER TROUGH AND WEAK FRONTAL BOUNDARY GET INTO THE PICTURE. DEVELOPMENT UPSTREAM EXPECTED TO DECREASE TONIGHT BUT SAG DOWN INTO THE AREA LATER. SHWRS/STMS THEN EXPECTED TO INCREASE EARLY TUE AND REMAIN FAIRLY WIDESPREAD WELL INTO TUE EVE. ALL SITES HAVE GOOD CHANCE OF BEING AFFECTED... WHICH WILL REDUCE CIGS/VSBYS. BEST CHANCE LARGELY AFTER 15Z TUE. WINDS ALSO EXPECTED TO GUST 20+KTS BY 15Z. PREV DISCUSSION... /ISSUED 627 PM CDT MON JUL 7 2014/ DISCUSSION... MCS CURRENTLY NOT TOO FAR OFF TO THE NORTH WITH THE CONVECTION AS FAR SOUTH AS HOPKINS AND MUHLENBERG COUNTIES. HRRR AND MODEL DATA SUGGESTS THAT THIS CONVECTION WILL WEAKEN QUICKLY AS IT APPROACHES. HOWEVER...THOUGH SOME WEAKENING IS EXPECTED...I FEEL AS IF POPS ACROSS THE NORTH MAY NEED TO BE INCREASED SLIGHTLY. SOME WIND DAMAGE HAS ALREADY OCCURRED WITH A FEW OF THESE STORMS EARLIER THIS AFTERNOON. LATEST MID LEVEL FLOW PATTERN SUGGESTS THAT THE STORMS WILL ENCOUNTER LESS FAVORABLE SHEAR AS THEY MOVE SOUTHWARD...SO BOTH THE INTENSITY AND COVERAGE SHOULD BE ON THE DECREASE. OTW...TOWARD 12Z...WE`LL SEE AN INCREASE IN ATMOSPHERIC MOISTURE WITH SOME ADDITIONAL DEVELOPMENT CONTINUING TO MOVE SOUTHWARD. FOR THE FCST...WILL LEAN TOWARD INCREASING POPS SOME OVERNIGHT. WHEN COMBINING THE CURRENT ACTIVITY WITH ADDITIONAL FAVORABLE CONVECTIVE CONDITIONS TOWARD 12Z...WILL NEED TO GO A LITTLE HIGHER THAN JUST A SLIGHT CHANCE. REMAINDER OF THE FCST APPEARS TO BE OK. WILL ADD A FEW EXTRA CLOUDS ACROSS THE NORTH. OVERNIGHT LOWS SHOULD BE WARMER TONIGHT AS DEWPOINT VALUES WERE HIGHER TODAY. UPDATE OUT SHORTLY. PREV DISCUSSION... /ISSUED 327 PM CDT MON JUL 7 2014/ DISCUSSION... HEAT AND MOISTURE HAVE RETURNED IN EARNEST TODAY WITH TEMPERATURES CURRENTLY RANGING FROM THE LOW 80S ON THE PLATEAU TO UPPER 80S/LOW 90S ELSEWHERE...ALONG WITH DEWPOINTS UP INTO THE 60S AND LOW 70S. WEAK SHORTWAVE TROUGH ALOFT NOTED ON WATER VAPOR IMAGERY HAS PROVIDED ENOUGH LIFT TO SPAWN SOME ISOLATED SHOWERS AND THUNDERSTORMS OVER SOUTHWEST ZONES THIS AFTERNOON. HAVE INCLUDED A PRE FIRST PERIOD FOR WESTERN ZONES ON ACCOUNT OF THIS DIURNALLY DRIVEN ACTIVITY. OTHERWISE...ATTENTION TURNS TO THE NORTH AS CONVECTION IS BLOSSOMING ALONG A WEAK COLD FRONT ADVANCING SOUTHWARD THROUGH THE MIDWEST. 12Z MODELS INDICATE THIS ACTIVITY...ALONG WITH AN EXPECTED MCS DEVELOPING NEAR KANSAS CITY...WILL MAKE A RUN AT OUR NORTHWEST ZONES LATE TONIGHT. CONSIDERABLE UNCERTAINTY ON HOW FAR THIS ACTIVITY WILL SURVIVE AND AT WHAT INTENSITY...BUT WARRANTS LOW CHANCE POPS OVER NORTHERN ZONES ESPECIALLY TOWARDS SUNRISE TUESDAY MORNING. CANNOT COMPLETELY RULE OUT A STRONG OR POSSIBLY EVEN SEVERE STORM IF CONVECTION CAN SURVIVE THIS FAR SOUTH AS SPC HAS INDICATED IN THEIR DAY 1 OUTLOOK...BUT FAR BETTER CHANCE FOR STRONG TO SEVERE STORMS WILL BE WELL OFF TO OUR NORTH. ON TUESDAY...REMNANTS OF MCS SHOULD WEAKEN/DISSIPATE WITH ALL GUIDANCE INDICATING RENEWED CONVECTIVE DEVELOPMENT ALONG FRONTAL BOUNDARY SITUATED NEAR THE OHIO RIVER TUESDAY AFTERNOON. 12Z GUIDANCE HAS SPED UP ARRIVAL OF THIS ACTIVITY WITH STORMS LIKELY REACHING THE KY BORDER BY LATE AFTERNOON...THEN MOVING ACROSS THE MID STATE THROUGH THE EVENING BEFORE WEAKENING LATE TUESDAY NIGHT. HAVE KEPT POPS ABOVE GUIDANCE IN THE LIKELY TO CATEGORICAL RANGE DUE TO CONFIDENCE IN THIS SCENARIO. 12Z GFS/NAM FORECAST SOUNDINGS ARE MORE ROBUST WITH INSTABILITY VS THIS TIME YESTERDAY SHOWING LI VALUES AS LOW AS -7 TO -8 ALONG WITH SBCAPE AS HIGH AS 3000 J/KG. THESE PARAMETERS ALONG WITH DEEP LAYER SHEAR AROUND 40 KNOTS AND PWAT VALUES UP TO 2 INCHES SUGGESTS STRONG TO SEVERE STORMS WILL BE POSSIBLE WITH DAMAGING WINDS AND LOCALLY HEAVY RAINFALL THE MAIN THREATS...WITH HIGHEST RISK ALONG AND NORTH OF I-40 LATE TUESDAY AFTERNOON INTO TUESDAY EVENING. HOWEVER...SPC HAS HIGHLIGHTED THE ENTIRE MID STATE IN A SLIGHT RISK FOR SEVERE STORMS ON THEIR DAY 2 OUTLOOK. WEAK COLD FRONT WILL SHIFT SLOWLY SOUTHWARD THROUGH THE MID STATE DURING THE DAY ON WEDNESDAY...WITH ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT POSSIBLE ALONG THE BOUNDARY OVER SOUTHERN ZONES. FRONT PROGGED TO SHIFT SOUTH OF THE AL BORDER BY WEDNESDAY NIGHT WITH SLIGHTLY COOLER AND DRY WEATHER ANTICIPATED THURSDAY AND FRIDAY. STAYED VERY CLOSE TO PREVIOUS FORECAST TEMPS DURING THIS TIMEFRAME...WHICH ARE ALSO VERY CLOSE TO 12Z MEX GUIDANCE. BY NEXT WEEKEND...MODELS BUILD A STRONG RIDGE OVER THE SOUTHERN PLAINS EASTWARD INTO THE TENNESSEE VALLEY...SUGGESTING A SHARP WARMUP FOR SATURDAY AND SUNDAY WITH HIGHS BACK INTO THE MID 90S FOR MUCH OF MIDDLE TENNESSEE. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1130 PM CDT MON JUL 7 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 203 PM CDT MON JUL 7 2014 MAIN SHORT TERM CONCERN IS ON SEVERE POTENTIAL THROUGH THE EVENING. CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA WHILE TROUGHING PRESIDED OVER EASTERN CANADA. THE MAIN FEATURE OF INTEREST WAS A FAIRLY POTENT SHORTWAVE AT THE SOUTHWEST END OF THIS TROUGHING OVER NORTH DAKOTA. A CLUSTER OF SHOWERS AND THUNDERSTORMS CONTINUES TO ROLL AHEAD OF THE SHORTWAVE IN THE DPVA REGION...BEING ENHANCED NOW BY DAYTIME HEATING. THERE IS ALSO AN UPPER JET STREAK GOING FROM MONTANA INTO SOUTH DAKOTA...PROVIDING UPPER DIVERGENCE FOR THOSE STORMS. CLOSER TO THE FORECAST AREA...SHOWERS AND THUNDERSTORMS HAVE BEEN DEVELOPING FROM CENTRAL MN INTO THE NORTH HALF OF WI. A WEAK SHORTWAVE TRAVERSING THROUGH THE FLOW...COMBINED WITH WEAK MID LEVEL FRONTOGENESIS AND 1000 J/KG OF UNCAPPED MLCAPE PER RAP ARE CONTRIBUTING TO THEIR DEVELOPMENT. HAVE HAD A FEW ISOLATED SEVERE SUPERCELLS DEVELOP TOO. ANOTHER PLUME OF LITTLE HIGHER INSTABILITY...1000-2000 J/KG PER RAP...WAS EVIDENT ACROSS NORTH CENTRAL IOWA STREAMING NORTHEASTWARD ASSOCIATED WITH CORN EVAPOTRANSPORATION. TEMPERATURES HAVE CLIMBED NICELY DUE TO CLEAR SKIES THIS MORNING AND HAVING 850MB TEMPS OF 15-18C. MAIN SURFACE COLD FRONT EXTENDED FROM NORTHERN MN INTO EASTERN SOUTH DAKOTA. THE POTENT SHORTWAVE OVER NORTH DAKOTA IS FORECAST TO MOVE SOUTHEAST ACROSS THE FORECAST AREA OVERNIGHT TONIGHT. IN RESPONSE...THERE ARE SOME VERY IMPRESSIVE 500MB HEIGHT FALLS FOR EARLY JULY...ON THE ORDER OF 60-80 METERS IN 12 HOURS. NEEDLESS TO SAY...THERE IS PLENTY OF DYNAMIC FORCING COMING ACROSS THIS EVENING. ADDITIONALLY...THAT UPPER JET STREAK GOING ACROSS SOUTH DAKOTA NOW SHOULD SLIDE JUST TO OUR SOUTH IN IOWA...PROVIDING UPPER DIVERGENCE SUPPORT. THROW IN LINGERING AFTERNOON INSTABILITY AND THIS PROVIDES A GREAT RECIPE FOR CONVECTION THIS EVENING. MAJORITY OF DETERMINISTIC AND HIGH RESOLUTION MODELS AGREE AS WELL...WITH A MAX PRECIPITATION COVERAGE TIME LIKELY CENTERED NEAR 03Z. THE GREATEST SEVERE POTENTIAL WILL EXIST MOSTLY BETWEEN 23-03Z... WHEN THE DYNAMICS ARE JUXTAPOSED ON TOP OF THE THERMODYNAMICS...AND STORMS CAN MAINTAIN SOME ISOLATION OF INFLOW. STILL COULD HAVE SOME ISOLATED SEVERE BEFORE THEN LIKE WE ARE OBSERVING NOW. 0-3KM AND 0-6 KM SHEAR STILL REMAIN FAVORABLE FOR ORGANIZED SEVERE CONVECTION...30- 35 KT AND 40-55 KT RESPECTIVELY. HODOGRAPHS ARE MAINLY STRAIGHT LINE...SUGGESTING SPLITTING SUPERCELLS...WHILE THE SHEAR ALSO FAVORS BOWING LINE SEGMENTS. GIVEN A MAINLY UNIDIRECTIONAL FLOW FROM SURFACE TO THE MID LEVELS...BELIEVE DAMAGING WINDS AND LARGE HAIL ARE THE MAIN CONCERNS. STRONG SUBSIDENCE IN THE WAKE OF THE POTENT SHORTWAVE OVERNIGHT SHOULD HELP TO CLEAR THE PRECIPITATION WEST TO EAST. THE FORECAST AREA COULD BE COMPLETELY DRY BY 09Z. ATTENTION THEN TURNS TO THE UPPER TROUGH SET UP FROM NORTHERN ONTARIO SOUTHWARD THROUGH THE WESTERN GREAT LAKES REGION ON TUESDAY. THE COLD POOL ASSOCIATED WITH THIS TROUGH...REFLECTED BY 500MB TEMPS OF -13 TO -15C...COULD BE ENOUGH TO INSTIGATE SOME SHOWERS AND THUNDERSTORMS WITH DAYTIME HEATING. HOWEVER...THERE ARE SOME ISSUES THAT WOULD FAVOR A DRIER FORECAST. FIRST...MODELS AGAIN ARE LIKELY OVERDOING SURFACE DEWPOINTS AND INSTABILITY...ESPECIALLY GIVEN A NORTHWEST FLOW WOULD FAVOR A GOOD DRYING/MIXING SCENARIO. SECOND...SHORTWAVES ROTATING THROUGH THE UPPER TROUGH APPEAR TO TRACK NORTH OF THE FORECAST AREA. THUS...HAVE ONLY KEPT PRECIPITATION CHANCES IN THE 20-30 RANGE. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 203 PM CDT MON JUL 7 2014 A NICE DRY PERIOD IS EXPECTED FOR THE FORECAST AREA TUESDAY NIGHT THROUGH THURSDAY...RESULTING FROM THE UPPER TROUGH GRADUALLY SHIFTING EAST...UPPER RIDGING EVENTUALLY BUILDING INTO THE AREA BY 00Z FRIDAY...AND SURFACE RIDGING BUILDING IN. PRECIPITABLE WATER IS ALSO FORECAST BETWEEN 0.5-1 INCH...OR ANYWHERE FROM 50-100 PERCENT OF NORMAL...SUPPORTING A DRY FORECAST AND ALSO ALLOWING FOR LARGER DIURNAL SWINGS. NIGHTTIME LOWS COULD GET RELATIVELY CHILLY WEDNESDAY NIGHT IN CENTRAL WISCONSIN WITH THE SURFACE RIDGE OVERHEAD. THEREFORE IT ALSO SEEMS TO BE THE BEST NIGHT TO HAVE TRIBUTARY VALLEY FOG. THE WEATHER THEN STARTS TO POSSIBLY TURN MORE ACTIVE AGAIN LATE THURSDAY NIGHT AND RIGHT INTO THE WEEKEND. THIS IS A RESULT OF VERY GOOD MOISTURE RETURN...CHARACTERIZED BY PRECIPITABLE WATER UPWARDS OF 1.5-1.8 INCHES...FLOWING BACK INTO THE AREA ON THE BACK SIDE OF THE SURFACE HIGH. MEANWHILE...IN THE SYNOPTIC SCALE...AN UPPER TROUGH IS PROGGED TO DROP SOUTH OUT OF CANADA INTO OUR REGION. SOME OF THE DETAILS ARE HARD TO PIN DOWN RIGHT NOW...BUT CERTAINLY FROM LATE THURSDAY NIGHT THROUGH SUNDAY THERE COULD BE OFF AND ON SHOWERS AND THUNDERSTORMS AROUND. THIS CREATES SOME UNCERTAINTY ON TEMPERATURES...ESPECIALLY GIVEN THAT AT LEAST FRIDAY 850MB TEMPS ARE 15-18C AND COULD BE SIMILAR ON SATURDAY. NOTE THAT A GENERAL COOLING IS EXPECTED HEADING INTO EARLY NEXT WEEK...ESPECIALLY IF THE 07.00Z/12Z ECMWF RUNS ARE RIGHT WHERE THEY SHOW 850MB TEMPS FALLING TO 6C ON MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1130 PM CDT MON JUL 7 2014 STORMS HAVE EXITED...LEAVING SKC/SCT SKIES. SEE SOME THREAT FOR FOG IF WINDS WOULD DECOUPLE AT KLSE. SFC PRESSURE GRADIENT WILL STAY TIGHT THROUGH THE NIGHT THOUGH...AND NOT MUCH INDICATION OF DECOUPLING VIA THE BUFKIT SOUNDINGS. SO WILL MONITOR...BUT DON/T THINK VALLEY FOG IS FAVORABLE AT THE MOMENT. FOR TUE...WI WILL BE UNDER CYCLONIC FLOW AS THE UPPER LEVEL LOW EXITS EAST. SHOULD SEE BKN CIGS DEVELOP OVER CENTRAL/EASTERN WI...WITH SOME AFTERNOON -SHRA POSSIBLE. COULD SEE SOME BKN VFR AT KLSE...BUT BELIEVE THE BULK OF THE -SRHA THREAT WILL STAY EAST. && .HYDROLOGY... ISSUED AT 203 PM CDT MON JUL 7 2014 THE MISSISSIPPI RIVER CONTINUES TO FALL. IN FACT...WE ARE EXPECTING ALL THE RIVER FORECAST POINTS WITHIN THE ARX FORECAST AREA TO FALL BELOW FLOOD STAGE BY THURSDAY FROM NORTH TO SOUTH. FLOOD WARNINGS HAVE BEEN CANCELLED AT WINONA AND LA CROSSE AND WILL SOON BE AT WABASHA. PERIODIC RAIN IS FORECAST OVER THE NEXT FEW DAYS...BUT IT APPEARS THIS RAINFALL WILL NOT BE ENOUGH TO HAVE A SIGNIFICANT IMPACT ON THE MISSISSIPPI...OR ITS TRIBUTARIES FOR THAT MATTER. FOR THE CURRENT AND FORECAST RIVER LEVELS...SEE OUR INTERNET PAGE AT WWW.WEATHER.GOV/LACROSSE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM....AJ AVIATION.....RIECK HYDROLOGY....AJ
AREA FORECAST DISCUSSION
NWS PADUCAH KY
658 AM CDT Tue Jul 8 2014 .UPDATE... Issued at 658 AM CDT TUE JUL 8 2014 The AVIATION section has been updated for the 12Z TAF issuance. && .SHORT TERM...(Today through Thursday) Issued at 258 AM CDT TUE JUL 8 2014 The bulk of the short term period will be dependent on the evolution of the MCS just about to enter southwest Illinois and southeast Missouri. The leading line convection has diminished significantly, as have the winds behind the line. Have not seen any severe wind reports for quite awhile upstream, and really would not expect the system to increase. The RAP indicates that the 0-3km shear is very weak and parallel to the leading line. There appears to be a comma head/MCV feature moving east across central Illinois, and that should continue to push away from our area. Meanwhile, Corfidi Vectors over Missouri indicate a southward propagation. Therefore, we may be in for some sort of split for our area. There is decent surface air, theta-e values in the 345-349 range, throughout southern Illinois and southeast Missouri, so would expect convection to continue to bounce around on the outflow boundary as it moves southeast through southern Illinois and southeast Missouri through daybreak. With disorganized leading convection, figure the stratiform area will also begin to diminish, so there will likely be a significant weakening trend in the coverage of precipitation over the area in the 12z-15Z timeframe. The big question then is where will storms be able to fire up this afternoon and evening? The cold front is located from southeast Iowa to north central Kansas as of 730Z, and it does not have a tremendous push with it. The consensus of 00Z guidance brings into the northwest part of the region this afternoon, and surface dewpoints in the lower 70s are expected ahead of the front. Therefore, much of the area may be under the gun for more convection along and ahead of the cold front this afternoon and evening. The hi-res guidance really seems to be focusing on the southern third of the area for development. Perhaps the MCS will thoroughly stabilize the airmass across the northern half of the area. I really don`t have a good feel for this one. Decided to go with a band of low-end likely PoPs in the north around 18Z, and then push it slowly southeast through the afternoon and into the evening. Feel that it will be out of the area by 06Z tonight, but left a chancy PoP in the southeast overnight just to be safe. Enough dry air should arrive to keep the area dry for Wednesday, despite decent cyclonic flow aloft. A few severe storms will be possible this afternoon, if we can destabilize enough. The wind fields should be strong enough to support a few severe storms with damaging winds the main concern. Temperatures today are a crap shoot with the convection and convective debris expected. Therefore, went close to consensus guidance. Went on the warm side of guidance for tonight with only weak cool, dry advection expected. Consensus should be close again Wednesday with the dry air advecting/mixing across the region. Trended a bit cooler for Wednesday night and warmer Thursday, both due to the dry airmass expected. .LONG TERM...(Thursday Night through Monday) Issued at 258 AM CDT TUE JUL 8 2014 High pressure will continue to bring dry weather Thursday night before moving off to the east on Friday. Temperatures and dewpoints will climb a couple of degrees per day through the weekend on warm and moist low level winds. Thursday night lows in the middle 60s will give way to lows over the weekend in the lower 70s. Highs will nudge up from the upper 80s on Friday into the lower 90s for the weekend. Aloft, the region will stay in northwesterly flow on the fringe of an upper level low. While an isolated chance of a shower or storm will be possible on Saturday, the better chance will come Sunday as an upper level disturbance moves north of the region. Chance pops in the northeastern part of the forecast area will lower to slight pops over the Ozark foothills. Models are highly variable with the weather early next week. The GFS aggressively pushes a front through the Ohio Valley on Monday and stalls it over the Tennessee Valley before lifting back north late Tuesday hinting at a very wet period for our region. The ECMWF on the other hand is much weaker with the front on Monday but does also stall it to our south. It, however, keeps it to our south through the better part of the week with energy producing rain chances up around the Great Lakes and to our south along the stalled boundary. At any rate, have high chance pops on Monday with the passage of a frontal boundary. Temperatures will be tempered somewhat on Monday with cloud cover and precipitation with highs back down into the upper 80s. && .AVIATION... Issued at 658 AM CDT TUE JUL 8 2014 Area VAD wind profiles indicate that there is 30kts of west or west northwest winds available to mix down this morning. The latest guidance advertises sustained winds into the teens, and some gusts to 20kts or a bit more through the morning. As a cold front moves through the area, at least scattered thunderstorms are expected to develop and move east southeast across the entire region this afternoon. VCTS seems to be the most reasonable approach at this time, since confidence in the coverage and timing is low. Winds will become northwest by this evening, but they will be light for much of the night. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...DRS SHORT TERM...DRS LONG TERM...ML AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1145 AM EDT TUE JUL 8 2014 .SYNOPSIS... SHOWERS AND THUNDERSTORMS WILL ACCOMPANY A COLD FRONT PASSAGE TODAY AND THIS EVENING. A SECONDARY FRONT WILL PUSH THROUGH WEDNESDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... REMNANTS OF THE MCS WILL CONTINUE TO SHIFT NORTHEASTWARD THROUGH THE REST OF THIS MORNING. HOWEVER...STORMS HAVE ALREADY DEVELOPED ALONG THE SOUTHERN FLANK OF THIS SYSTEM OVER WESTERN OHIO. BASED ON THE MOST RECENT HRRR DATA...THIS LOOKS TO BE WHERE FURTHER DEVELOPMENT WILL OCCUR AS THE SHORTWAVE/FRONT ASSOCIATED WITH THIS SHIFTS TOWARDS THE REGION. THE BEST TIMING FOR CONVECTIVE DEVELOPMENT BASED ON THE HI RES MODELS AND THE NAM SUGGEST AS EARLY AS 1-2PM. WHILE SHEAR WILL BE INCREASING...ESPECIALLY OVER THE NORTHERN HALF OF THE CWA DUE TO STRENGTHENING LOW-MID LEVEL JET DYNAMICS...THERE ARE CONCERNS THAT THE ABUNDANCE OF CLOUD COVER WILL LIMIT HEATING AND DESTABILIZATION. STILL...WITH SUCH STRONG UPPER LEVEL SUPPORT...EVEN MODEST CAPE SHOULD SUPPORT SOME STRONG TO SEVERE STORMS. WILL CONTINUE TO MONITOR THE CONDITIONS AS WE GO INTO THE AFTERNOON AND HIGHLIGHT WIND AS THE PRIMARY THREAT...ALTHOUGH AN ISOLATED TORNADO COULD NOT BE RULED OUT. PWAT VALUES WILL ALSO BE IN THE 1.50-1.75 RANGE THROUGH THIS EVENING...SO HEAVY DOWNPOURS AND SOME LOCALIZED FLOODING COULD BE POSSIBLE. ALL OF THE MODEL GUIDANCE SUGGESTS THAT A SECOND LINE OF SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE LATER THIS EVENING WITH ANOTHER WEAK SHORTWAVE PASSAGE. CONSIDERING ITS LATER TIMING...DO NOT EXPECT THERE TO BE AS MUCH OF A THREAT FOR SEVERE WITH IT...BUT WILL KEEP LIKELY POPS THROUGH THE FIRST HALF OF TONIGHT. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... INSTABILITY WITH COLDER AIR ALOFT WITH TROUGHING OVER THE REGION WILL CONTINUE THE CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE DAY ON WEDNESDAY BEFORE HIGH PRESSURE BEGINS TO REGAIN CONTROL WEDNESDAY NIGHT. SFC HIGH PRESSURE BUILDS IN OVER THE SRN GREAT LAKES WEDS NIGHT INTO THURS WITH DRYING EXPECTED. DAYTIME HIGHS SHOULD TOP OUT NEAR AVERAGE FOR THIS TIME OF YEAR...WHILE NIGHTTIME LOWS THURS AND FRI COULD BE A FEW DEGREES COOLER THAN AVERAGE AS MOSTLY CLEAR SKIES AND CALM WINDS WILL ALLOW ENHANCED RADIATIONAL COOLING. && .LONG TERM /SATURDAY THROUGH MONDAY/... SFC HIGH GETS SQUEEZED OUT OF THE AREA SAT AS A WEAK AND RELATIVELY DRY FRONT SAGS SOUTHWARD THROUGH THE GREAT LAKES AND APPROACHES FOR SUN. MODELS HAVING A DIFFICULT TIME CONVERGING ON A SINGLE SOLN NEXT WEEKEND...BUT THEY DO DEPICT THE FRONT REINFORCING THE BROAD UPPER TROF OVER THE ERN CONUS. COOLER AIR SHOULD BEGIN TO SEEP IN FROM THE NORTHWEST UNDER THIS REGIME...WITH MULTIPLE DISTURBANCES PASSING THROUGH THE TROF. TRENDED TEMPS A BIT LOWER HEADING INTO NEXT WEEKEND...AND CONTINUED WITH LESS DETERMINISTIC POPS...ORIENTING HIGHER CHC POPS ALONG THE FRONT. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... PTCHY MVFR SC WL CONT THIS MRNG BEFORE AN IMPROVEMENT TO VFR. AN MCS ACRS OH SHOULD CONT TO WKN PER RECENT VIL LOOPS AND STLT TRENDS. EXP REDEVELOPMENT OF A BKN LN OF TSTMS LT THIS MRNG INTO THE AFTN AS A CDFNT ADVNS ACRS THE RGN...WITH A PD OF AT LEAST MVFR RSTRNS AND GUSTY WNDS. EXP A LT AFTN/EVE FROPA WITH GENL VFR CONDS TO FOLLOW. .OUTLOOK.../WEDNESDAY THROUGH SATURDAY/... RSTRNS ARE PSBL IN SCT TSTMS WED WITH A CROSSING DISTURBANCE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
916 AM CDT TUE JUL 8 2014 .UPDATE... ISSUED AT 914 AM CDT TUE JUL 8 2014 UPDATED TO INCREASE POPS TODAY WITH THE SCATTERED RAIN SHOWERS AND POSSIBLY A FEW ISOLATED WEAK STORMS ACROSS THE REGION IN THE AFTERNOON. NO OTHER SIGNIFICANT CHANGES MADE TO THE SHORT TERM FORECAST AT THIS TIME. && .SYNOPSIS... ISSUED AT 301 AM CDT TUE JUL 8 2014 MID LVL LOW OVER HUDSON BAY EARLY THIS MORNING WITH A FAIRLY LARGE AREA OF CYCLONIC CIRCULATION ASSOCIATED WITH ITS PRESENCE. WITHIN THE CIRCULATION MULTIPLE SHORTWAVE TROFS CONTINUE TO MOVE WITHIN THE FLOW. LATEST WV IMAGERY SHOWS AT LEAST 3 SHORTWAVES EVIDENT ACROSS WRN ONTARIO AND MANITOBA. SCTD SHOWERS CONTINUE TO DEVELOP/OCCUR OVER ERN THIRD OF CWA DESPITE LOSS OF EARLIER INSTABILITY. A WELL DEFINED SHEAR AXIS/WIND SHIFT IS INDICATED IN THE 925 FLOW FROM ERN LAKE COUNTY IN THE ARROWHEAD CURVING THROUGH THE APOSTLES. THIS IS RELATED TO A BACKDOOR FRONTAL BDRY REPRESENTED IN THE LOW LVL THERMAL FIELDS. HEAVY PRECIP...RADAR ESTIMATES AND GROUND REPORT OVER 2 INCHES IN IRON COUNTY...HAS MOVED OUT OF THE CWA. CALLS TO LOCAL LAW OFFICIALS IN THE AREA AND CHECK ON A FEW RIVERS INDICATES THREAT APPEARS TO BE OVER. HAVE LET FLS EXPIRE AT 3AM. && .SHORT TERM...(TODAY THROUGH TOMORROW) ISSUED AT 301 AM CDT TUE JUL 8 2014 TODAY...BACK DOOR FRONTAL BDRY WILL MOVE INTO THE TWIN PORTS EARLY IN THE MORNING AND WEAKEN BY MIDDAY. DISTURBING DIFFERENCES BETWEEN MDLS WITH REGARD TO TIME/HEIGHT XSEC OF MOISTURE WITH EC SUGGESTING WHATEVER LOW CLOUD IS EVIDENT IN MORNING WILL LIFT WITH DAYTIME WARMING. NAM12/RAP SUGGEST A LOW OVERCAST MAY DWELL INTO AFTERNOON AROUND LAKE SUPERIOR. WILL GO PESSIMISTIC IN MORNING AND IMPROVING TREND IN AFTN. PESKY UPPER AIR PATTERN MAKES PLACEMENT OF HIGHEST POPS A BIT CHALLENGING TODAY SO ADDITIONAL UPDATES MAY BE NECESSARY. WITH A LACK OF A LOW LVL FOCUS FOR BDRY LYR CONVERGENCE THE POPS ARE BASED ON A GUESSTIMATE OF THE AXIS OF GREATEST INSTABILITY. USING RUC13 THIS APPEARS TO LINE UP FROM THE IRON RANGE TO NW WISC DURING THE MAJORITY OF THE DIURNAL WARMING. HI RES SIM REFL PRODUCTS SHOW NATURE OF SYNOPTIC PATTERN WITH LARGE INCREASE IN INSTABILITY ECHOES LATE MORNING THROUGH EARLY EVENING OVER MOST OF CWA. SIGNIFICANT DECREASE IN 925 TEMPS COMPARED TO YESTERDAY SO MAX TEMPS WILL BE ABOUT 5 TO 10 DEGREES COOLER IN MANY AREAS. TONIGHT/TOMORROW...MID LVL TROF OVER ONTARIO AND THE GT LAKES WILL SLOWLY SHIFT EAST. LOW LVL CYCLONIC CIRCULATION WILL BE REPLACED BY ANTICYCLONIC FLOW AS A WEAK SFC HIGH MOVES ACROSS UPPER MIDWEST WEDNESDAY. HAVE INSERTED VERY LOW POPS OVER SERN PART OF CWA IN THE AFTN WITH AXIS OF FCST INSTABILITY....ALBEIT MEAGER...IN THE VICINITY. OTHERWISE A PLEASANT DAY WITH NEAR TYPICAL TEMPS. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 301 AM CDT TUE JUL 8 2014 THE AREA OF HIGH PRESSURE WILL CONTINUE TO DOMINATE THE FORECAST AREA THROUGH THURSDAY AFTERNOON. THE TEMPERATURES WILL BE AT OR A LITTLE BELOW THEIR NORMAL VALUES. A WEAK SHORTWAVE WILL MOVE THROUGH CENTRAL MINNESOTA THURSDAY AFTERNOON AND MAY BRING A SHOWER OR THUNDERSTORMS TO SOUTHERN CASS AND CROW WING COUNTIES BUT THESE POPS WILL BE LOW. A COLD FRONT WILL APPROACH THE REGION THURSDAY NIGHT AND MOVE THROUGH THE FORECAST AREA ON FRIDAY AND FRIDAY NIGHT. WITH THE INCREASED MOISTURE AHEAD OF THE FRONT...THERE WILL BE A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. THE GFS IS FASTER THAN THE ECMWF WITH HIS FEATURE. BOTH MODELS NOW AGREE THAT SATURDAY WILL BE DRY WITH THE BULK OF THE PRECIP SOUTH OF THE FORECAST AREA. THE GFS HAS A FRONT MOVING THROUGH THE REGION ON SUNDAY WITH THE ECMWF A LITTLE SLOWER WITH THE FEATURE. WILL GO WITH A COMPROMISE AT THE MOMENT BUT WILL REFINE AS THE WEEKEND GETS CLOSER. HIGH PRESSURE BUILDS IN FOR THE BEGINNING OF THE WORK WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 645 AM CDT TUE JUL 8 2014 MAINLY MVFR/IFR CIGS ACROSS TAF SITES EXCEPT FOR BRD WHERE VFR CONDITIONS ARE DOMINANT. CONDITIONS SHOULD IMPROVE TO VFR AT ALL SITES BY LATE MORNING. BUT...MVFR CONDITIONS ARE POSSIBLE THIS AFTERNOON WITH SHOWERS AND ISOLATED THUNDERSTORMS DUE TO SOLAR HEATING. CONDITIONS WILL IMPROVE TO VFR AFTER SUNSET AS AN AREA OF HIGH PRESSURE BUILDS INTO THE FORECAST AREA. && .PRELIMINARY POINT TEMPS/POPS... DLH 66 50 72 52 / 50 20 0 0 INL 66 48 72 50 / 60 20 0 0 BRD 75 52 76 55 / 20 10 0 0 HYR 70 49 74 49 / 60 30 10 0 ASX 63 48 70 49 / 20 20 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ UPDATE...BJT SYNOPSIS...CANNON SHORT TERM...CANNON LONG TERM...STEWART AVIATION...STEWART
AREA FORECAST DISCUSSION
NWS DULUTH MN
644 AM CDT TUE JUL 8 2014 .SYNOPSIS... ISSUED AT 301 AM CDT TUE JUL 8 2014 MID LVL LOW OVER HUDSON BAY EARLY THIS MORNING WITH A FAIRLY LARGE AREA OF CYCLONIC CIRCULATION ASSOCIATED WITH ITS PRESENCE. WITHIN THE CIRCULATION MULTIPLE SHORTWAVE TROFS CONTINUE TO MOVE WITHIN THE FLOW. LATEST WV IMAGERY SHOWS AT LEAST 3 SHORTWAVES EVIDENT ACROSS WRN ONTARIO AND MANITOBA. SCTD SHOWERS CONTINUE TO DEVELOP/OCCUR OVER ERN THIRD OF CWA DESPITE LOSS OF EARLIER INSTABILITY. A WELL DEFINED SHEAR AXIS/WIND SHIFT IS INDICATED IN THE 925 FLOW FROM ERN LAKE COUNTY IN THE ARROWHEAD CURVING THROUGH THE APOSTLES. THIS IS RELATED TO A BACKDOOR FRONTAL BDRY REPRESENTED IN THE LOW LVL THERMAL FIELDS. HEAVY PRECIP...RADAR ESTIMATES AND GROUND REPORT OVER 2 INCHES IN IRON COUNTY...HAS MOVED OUT OF THE CWA. CALLS TO LOCAL LAW OFFICIALS IN THE AREA AND CHECK ON A FEW RIVERS INDICATES THREAT APPEARS TO BE OVER. HAVE LET FLS EXPIRE AT 3AM. && .SHORT TERM...(TODAY THROUGH TOMORROW) ISSUED AT 301 AM CDT TUE JUL 8 2014 TODAY...BACK DOOR FRONTAL BDRY WILL MOVE INTO THE TWIN PORTS EARLY IN THE MORNING AND WEAKEN BY MIDDAY. DISTURBING DIFFERENCES BETWEEN MDLS WITH REGARD TO TIME/HEIGHT XSEC OF MOISTURE WITH EC SUGGESTING WHATEVER LOW CLOUD IS EVIDENT IN MORNING WILL LIFT WITH DAYTIME WARMING. NAM12/RAP SUGGEST A LOW OVERCAST MAY DWELL INTO AFTERNOON AROUND LAKE SUPERIOR. WILL GO PESSIMISTIC IN MORNING AND IMPROVING TREND IN AFTN. PESKY UPPER AIR PATTERN MAKES PLACEMENT OF HIGHEST POPS A BIT CHALLENGING TODAY SO ADDITIONAL UPDATES MAY BE NECESSARY. WITH A LACK OF A LOW LVL FOCUS FOR BDRY LYR CONVERGENCE THE POPS ARE BASED ON A GUESSTIMATE OF THE AXIS OF GREATEST INSTABILITY. USING RUC13 THIS APPEARS TO LINE UP FROM THE IRON RANGE TO NW WISC DURING THE MAJORITY OF THE DIURNAL WARMING. HI RES SIM REFL PRODUCTS SHOW NATURE OF SYNOPTIC PATTERN WITH LARGE INCREASE IN INSTABILITY ECHOES LATE MORNING THROUGH EARLY EVENING OVER MOST OF CWA. SIGNIFICANT DECREASE IN 925 TEMPS COMPARED TO YESTERDAY SO MAX TEMPS WILL BE ABOUT 5 TO 10 DEGREES COOLER IN MANY AREAS. TONIGHT/TOMORROW...MID LVL TROF OVER ONTARIO AND THE GT LAKES WILL SLOWLY SHIFT EAST. LOW LVL CYCLONIC CIRCULATION WILL BE REPLACED BY ANTICYCLONIC FLOW AS A WEAK SFC HIGH MOVES ACROSS UPPER MIDWEST WEDNESDAY. HAVE INSERTED VERY LOW POPS OVER SERN PART OF CWA IN THE AFTN WITH AXIS OF FCST INSTABILITY....ALBEIT MEAGER...IN THE VICINITY. OTHERWISE A PLEASANT DAY WITH NEAR TYPICAL TEMPS. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 301 AM CDT TUE JUL 8 2014 THE AREA OF HIGH PRESSURE WILL CONTINUE TO DOMINATE THE FORECAST AREA THROUGH THURSDAY AFTERNOON. THE TEMPERATURES WILL BE AT OR A LITTLE BELOW THEIR NORMAL VALUES. A WEAK SHORTWAVE WILL MOVE THROUGH CENTRAL MINNESOTA THURSDAY AFTERNOON AND MAY BRING A SHOWER OR THUNDERSTORMS TO SOUTHERN CASS AND CROW WING COUNTIES BUT THESE POPS WILL BE LOW. A COLD FRONT WILL APPROACH THE REGION THURSDAY NIGHT AND MOVE THROUGH THE FORECAST AREA ON FRIDAY AND FRIDAY NIGHT. WITH THE INCREASED MOISTURE AHEAD OF THE FRONT...THERE WILL BE A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. THE GFS IS FASTER THAN THE ECMWF WITH HIS FEATURE. BOTH MODELS NOW AGREE THAT SATURDAY WILL BE DRY WITH THE BULK OF THE PRECIP SOUTH OF THE FORECAST AREA. THE GFS HAS A FRONT MOVING THROUGH THE REGION ON SUNDAY WITH THE ECMWF A LITTLE SLOWER WITH THE FEATURE. WILL GO WITH A COMPROMISE AT THE MOMENT BUT WILL REFINE AS THE WEEKEND GETS CLOSER. HIGH PRESSURE BUILDS IN FOR THE BEGINNING OF THE WORK WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 645 AM CDT TUE JUL 8 2014 MAINLY MVFR/IFR CIGS ACROSS TAF SITES EXCEPT FOR BRD WHERE VFR CONDTIONS ARE DOMINANT. CONDITIONS SHOULD IMPROVE TO VFR AT ALL SITES BY LATE MORNING. BUT...MVFR CONDITIONS ARE POSSIBLE THIS AFTERNOON WITH SHOWERS AND ISOLATED THUNDERSTORMS DUE TO SOLAR HEATING. CONDTIONS WILL IMPROVE TO VFR AFTER SUNSET AS AN AREA OF HIGH PRESSURE BUILDS INTO THE FORECAST AREA. && .PRELIMINARY POINT TEMPS/POPS... DLH 69 51 72 52 / 40 20 0 0 INL 67 48 72 50 / 40 20 0 0 BRD 74 53 76 55 / 20 10 0 0 HYR 71 49 74 49 / 50 20 10 0 ASX 66 49 70 49 / 40 30 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SYNOPSIS...CANNON SHORT TERM...CANNON LONG TERM...STEWART AVIATION...STEWART
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
739 AM CDT Tue Jul 8 2014 .UPDATE: Issued at 734 AM CDT Tue Jul 8 2014 Showers and isolated thunderstorms associated with decaying MCS have rapidly diminished early this morning, and based on latest regional radar trends primary threat will be confined to far southern sections of the FA over the next few hours. No changes to the afternoon trends at this time, with primary threat of redevelopment south of a Steelville-KCPS-Vandalia IL line. Zone update out shortly. Truett && .SHORT TERM: (Through Late This Afternoon) Issued at 353 AM CDT Tue Jul 8 2014 The weakening MCS moving southeastward through east central and southeast MO as well as southwest IL should shift southeast of our forecast area later this morning. The cold front now across northwest MO will move southeastward through the forecast area today. Although we could not rule out redevelopment of convection this afternoon along and just ahead of this cold front, it appears that the effective low level boundary will be the outflow from this mornings MCS which will be southeast of our forecast area this afternoon. The latest HRRR develops convection late this afternoon south and southeast of the forecast area. Even the operational models afternoon qpf is confined to the extreme southern or southeastern portion of our forecast area. For now will include chance pops across southeast MO and southwest IL, south and east of STL for this afternoon. High temperatures today will be slightly cooler than yesterday due to at least weak cold air advection behind the cold front and gradually lowering 850 mb temperatures. GKS .LONG TERM: (Tonight through Monday) Issued at 445 AM CDT Tue Jul 8 2014 It appears that the showers/storms will be south or southeast of our forecast area by this evening as a surface ridge builds southeastward into our area behind the cold front. This will bring cooler and less humid air into the region tonight and Wednesday. Will have at least slightly below normal temperatures for tonight through Wednesday night. The next chance of convection will occur over the northern portion of our forecast area late Thursday night and Friday morning due to strong low level warm air advection and moisture convergence on the nose of a southwesterly low level jet ahead of a northwest flow shortwave. The models were also depicting relatively strong upper level divergence ahead of this shortwave. A warming trend will also begin Thursday night and Friday along with increasing humidities due to southerly return flow on the backside of the surface ridge as it shifts east of the region. An upper level ridge will try to build northeastward into southwestern MO Friday night and Saturday. Any potential for convection should be confined to the northern and eastern portion of the forecast area as shortwaves move east southeastward over the upper level ridge. Temperatures should be quite warm this weekend, especially across central and southeast MO. There will be the chance of showers/storms across the entire area as we head into the next work week as the models deepen an upper level trough over the Great Lakes region and send a cold front southeastward through our forecast area Sunday night and Monday. The ECMWF model is stronger or deeper with this upper level trough compared to the GFS model and is also slower moving the front through our forecast area and has more qpf associated with this front. Due to the model inconsistencies will just include chance pops for most of the area on Monday along with cooler high temperatures. GKS && .AVIATION: (For the 12z TAFs through 12z Wednesday Morning) Issued at 633 AM CDT Tue Jul 8 2014 Surface obs have been indicating some very patchy stratus at several locations just before daybreak, so have also mentioned this at most locations as few or scattered deck between 1-2kft for the next 1-2 hours. Soundings then suggest a scattered CU field developing by mid morning with bases aoa 3kft, with these diurnally driven clouds then dissipate by early this evening. Consensus of all of the guidance suggests that any development that does develop this afternoon will be well south of our TAF sites, so forecast remains dry. Specifics for KSTL: Other than a bit of stratus with bases 1-2kft over the next hour or so, expecting scattered clouds with bases aoa 3kft from mid-morning into the afternoon with west-northwest winds in the 10-15 kt range. Clouds will dissipate and early this evening with loss of heating, with winds diminishing to less than 7 kts. Truett && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
646 AM CDT Tue Jul 8 2014 .SHORT TERM: (Through Late This Afternoon) Issued at 353 AM CDT Tue Jul 8 2014 The weakening MCS moving southeastward through east central and southeast MO as well as southwest IL should shift southeast of our forecast area later this morning. The cold front now across northwest MO will move southeastward through the forecast area today. Although we could not rule out redevelopment of convection this afternoon along and just ahead of this cold front, it appears that the effective low level boundary will be the outflow from this mornings MCS which will be southeast of our forecast area this afternoon. The latest HRRR develops convection late this afternoon south and southeast of the forecast area. Even the operational models afternoon qpf is confined to the extreme southern or southeastern portion of our forecast area. For now will include chance pops across southeast MO and southwest IL, south and east of STL for this afternoon. High temperatures today will be slightly cooler than yesterday due to at least weak cold air advection behind the cold front and gradually lowering 850 mb temperatures. GKS .LONG TERM: (Tonight through Monday) Issued at 445 AM CDT Tue Jul 8 2014 It appears that the showers/storms will be south or southeast of our forecast area by this evening as a surface ridge builds southeastward into our area behind the cold front. This will bring cooler and less humid air into the region tonight and Wednesday. Will have at least slightly below normal temperatures for tonight through Wednesday night. The next chance of convection will occur over the northern portion of our forecast area late Thursday night and Friday morning due to strong low level warm air advection and moisture convergence on the nose of a southwesterly low level jet ahead of a northwest flow shortwave. The models were also depicting relatively strong upper level divergence ahead of this shortwave. A warming trend will also begin Thursday night and Friday along with increasing humidities due to southerly return flow on the backside of the surface ridge as it shifts east of the region. An upper level ridge will try to build northeastward into southwestern MO Friday night and Saturday. Any potential for convection should be confined to the northern and eastern portion of the forecast area as shortwaves move east southeastward over the upper level ridge. Temperatures should be quite warm this weekend, especially across central and southeast MO. There will be the chance of showers/storms across the entire area as we head into the next work week as the models deepen an upper level trough over the Great Lakes region and send a cold front southeastward through our forecast area Sunday night and Monday. The ECMWF model is stronger or deeper with this upper level trough compared to the GFS model and is also slower moving the front through our forecast area and has more qpf associated with this front. Due to the model inconsistencies will just include chance pops for most of the area on Monday along with cooler high temperatures. GKS && .AVIATION: (For the 12z TAFs through 12z Wednesday Morning) Issued at 633 AM CDT Tue Jul 8 2014 Surface obs have been indicating some very patchy stratus at several locations just before daybreak, so have also mentioned this at most locations as few or scattered deck between 1-2kft for the next 1-2 hours. Soundings then suggest a scattered CU field developing by mid morning with bases aoa 3kft, with these diurnally driven clouds then dissipate by early this evening. Consensus of all of the guidance suggests that any development that does develop this afternoon will be well south of our TAF sites, so forecast remains dry. Specifics for KSTL: Other than a bit of stratus with bases 1-2kft over the next hour or so, expecting scattered clouds with bases aoa 3kft from mid-morning into the afternoon with west-northwest winds in the 10-15 kt range. Clouds will dissipate and early this evening with loss of heating, with winds diminishing to less than 7 kts. Truett && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
911 AM EDT TUE JUL 8 2014 .SYNOPSIS...A WEAK SURFACE TROUGH WILL LINGER OVER THE PIEDMONT THROUGH WEDNESDAY. A SLOW MOVING COLD FRONT WILL SETTLE INTO THE CAROLINAS FROM THE NORTHWEST WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 910 AM TUESDAY... THE LATEST SURFACE ANALYSIS SHOWED BROAD HIGH PRESSURE MOSTLY OVER THE MID-ATLANTIC AND THE CAROLINAS WITH A WEAK SURFACE TROUGH AMONG THE BROAD RIDGE OVER THE CENTRAL PIEDMONT. THE SPC MESOANALYSIS SHOWED A NOTICEABLE MINIMUM OF PRECIPITABLE WATER VALUES OVER THE WESTERN PART OF THE STATE...SIMILAR TO WHAT WAS FORECAST BY THE MONDAY GUIDANCE. THE RAP FORECASTS THIS MINIMUM TO MOVE ACROSS CENTRAL NORTH CAROLINA DURING THE DAY...AND FOR THE MOST PART RAP SOUNDINGS ARE SIMILAR TO SOUNDINGS FORECAST BY THE GFS MONDAY... QUITE STABLE TO DEEP CONVECTION DURING THE DAY. TWO CAVEATS TO THIS ARE CURRENTLY...AND VERY LATE TODAY. CURRENTLY...PRECIPITABLE WATER VALUES ARE AT OR ABOVE 1.5 INCHES OVER A LARGE PART OF CENTRAL NORTH CAROLINA...AND RAP SOUNDINGS SHOW THE PRESENCE OF MID-LEVEL INSTABILITY THAT WANES BY 18Z AS THE LOWER MOISTURE VALUES MOVE EAST. THE LATEST VISIBLE IMAGERY SHOWED A NARROW BAND OF MID-LEVEL CLOUDS THAT DEVELOPED FROM NEAR ROXBORO TO WADESBORO...AND THE HRRR WRF ACTUALLY FORECASTS A SHOWER OR TWO DEVELOPING FROM THIS. WATER VAPOR IMAGERY WOULD SUGGEST ENOUGH SUBSIDENCE TO PRECLUDE A SHOWER... BUT THE DEVELOPMENT OF THE CLOUDS PLUS THE PRESENCE OF WEAK INSTABILITY MAKES IT WORTHY OF NOTE HERE. LATE TODAY...THE RAP FORECASTS LIFT MOVING INTO THE FAR NORTHWEST PIEDMONT TOWARD KINT BY 23Z. RAP SOUNDINGS ARE STILL FAIRLY STABLE AT THAT POINT...AND QPF ON THE RAP IS NIL THROUGH 00Z WEDNESDAY. PRECIPITABLE WATER VALUES INCREASE QUICKLY ON THE RAP...TO NEAR 1.5 INCHES JUST AFTER 00Z WEDNESDAY...AS K INDICES RISE TO NEAR 40. LIKE THE GFS FORECAST MONDAY...MODEST MID-LEVEL COOLING COUPLED WITH MOISTURE ADVECTION MAY BE ENOUGH FOR A SHOWER OR THUNDERSTORM TO MOVE INTO THE WEST AND NORTHWEST PIEDMONT THIS EVENING. MOS GUIDANCE POPS ARE A FEW PERCENTAGE POINTS LOWER THAN THAT GUIDANCE OF MONDAY...AND WRF ARW GUIDANCE SUGGESTS LITTLE PRECIPITATION INTO THE EVENING. STILL...THE MOISTURE ADVECTION AND SLIGHT COOLING ALOFT... COUPLED WITH A WEAKENING MID-LEVEL SHORTWAVE MOVING INTO THE WESTERN PIEDMONT THIS EVENING...IS ENOUGH TO AT LEAST CONTINUE THE SMALL CHANCES WEST AS CURRENTLY FORECAST THIS EVENING...AND MAY NEED TO EXPAND SLIGHTLY FARTHER EAST. THE 00Z GFS APPEARED TO SUFFER FROM SOME MINOR CONVECTIVE FEEDBACK WHILE THE ECMWF HAS BEEN VERY CONSISTENT IN SUGGESTING THE BEST THREAT FOR OVERNIGHT CONVECTION TO OUR NW. IT SHOULD ALSO BE NOTED THAT THE CONVECTIVE ALLOWING MODELS VERIFIED WAY OVERDONE ACROSS THE OH VALLEY INTO THE MID ATLANTIC AT 06Z. HIGHS TODAY IN THE LOWER TO MID 90S. WARM OVERNIGHT WITH LOWS NEAR 70 TO THE LOWER 70S. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... AS OF 310 AM TUESDAY... MID LEVEL SHEAR AXIS ASSOCIATED WITH THE NORTHERN STREAM S/W AND ITS ATTENDANT SURFACE BOUNDARY WILL DRIFT SEWD INTO CENTRAL NC WEDNESDAY AFTERNOON-WEDNESDAY NIGHT. THIS SYSTEM WILL INTERACT WITH STRONG HEATING AND AVAILABLE MOISTURE (PRECIPITABLE WATER VALUES IN THE NEIGHBORHOOD OF 1.67-1.9 INCHES) TO INITIATE AND SUSTAIN SCATTERED CONVECTION...ESPECIALLY WEDNESDAY AFTERNOON-WEDNESDAY EVENING. SOME CONVECTIVE PARAMETERS SUGGEST SOME POTENTIAL FOR ORGANIZED CONVECTION IN THE FORM OF BROKEN CONVECTIVE SEGMENTS. IF THESE SEGMENTS WERE TO DEVELOP...COULD SEE A DAMAGING WIND THREAT WITH THE STRONGER CELLS. THIS THREAT APPEARS GREATEST ACROSS THE NORTHERN PIEDMONT INTO THE NORTHERN COASTAL PLAIN (GENERALLY NORTH OF I-40) WHERE BULK SHEAR VALUES APPROACH 30 KTS. DUE TO PRESENCE OF SHEAR AXIS AND SFC BOUNDARY...EXPECT SCATTERED CONVECTION TO PERSIST WELL INTO THE NIGHT THOUGH OVERALL COVERAGE AND INTENSITY WILL DIMINISH AS NEAR SURFACE AIR MASS UNDERGOES NOCTURNAL STABILIZATION. HIGH TEMPS WEDNESDAY DEPENDENT UPON AMOUNT OF INSOLATION AND CONVECTIVE COVERAGE. IF SUN LIMITED DUE TO EXTENSIVE CLOUD COVERAGE OR IF THE GFS IS CORRECT AND SCATTERED CONVECTION IS OCCURRING AT THE THE START OF THE DAY...THEN MAX TEMPS ACROSS THE NORTH COULD END UP BEING 5-6 DEGREES COOLER THAN FORECAST. DUE TO ANTICIPATED TIMING...BELIEVE THAT THE SOUTHERN HALF OF THE FORECAST AREA STANDS A GOOD SHOT OF SEEING TEMPS RETURNING TO THE MID 90S. MIN TEMPS WEDNESDAY NIGHT IN THE UPPER 60S TO AROUND 70 NORTH AND LOWER 70S SOUTH. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 310 AM TUESDAY... THURSDAY THROUGH FRIDAY: THURSDAY LOOKS TO BE THE MOST ACTIVE DAY OF THE FORECAST PERIOD AS AN APPROACHING MID LEVEL TROUGH WILL HELP TO SEND A WEAKENING COLD FRONT/SURFACE TROUGH SLOWLY ACROSS THE AREA. MODELS ARE IN GENERAL AGREEMENT IN SHOWING THE FRONT/SURFACE TROUGH LOCATED ACROSS CENTRAL NC DURING DURING PEAK HEATING THURSDAY. THE BEST MLCAPE AND MUCAPE IS EXPECTED TO BE LOCATED ACROSS THE SOUTHEASTERN HALF OF CENTRAL NC.... WHERE 800 TO 1200 J/KG MLCAPE IS EXPECTED... ALONG WITH UPWARDS OF 2000-2500 J/KG OF MUCAPE. THIS COMBINED WITH A MOIST AIR MASS CHARACTERIZED BY PW`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
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1040 AM EDT TUE JUL 8 2014 .SYNOPSIS... UNSETTLED WEATHER CONTINUES THROUGH EARLY WEDNESDAY AS A SERIES OF SYSTEMS PUSH EAST. HIGH PRESSURE BRINGS DRIER AIR TO THE REGION FOR THE END OF THE WEEK. ANOTHER SYSTEM OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... UPDATE... SLOWED THE POPS WITH LIKELIES AFTER 17Z. MAIN PORTION OF THE LEFTOVER MCS DRIFTED NORTHEAST AND MISSED OUR AREA FOR THE MOST PART. WILL BE WAITING FOR CLOUDS TO DISSIPATE...AND THEN EXPECT PERCOLATION THIS AFTERNOON. PREVIOUS DISCUSSION... CUT BACK POP CHCS FOR THE EARLY MORNING HOURS AS OVERNIGHT CONVECTION DIED OFF RAPIDLY WITH THE LOSS OF DAYTIME HEATING. NEAR TERM HI-RES MODELS RUC13 AND HRRR ARE IN FAIR AGREEMENT IN TRANSITIONING ANOTHER CONVECTIVE BAND ACROSS THE FORECAST AREA THIS AFTERNOON. MAIN FLY IN THE OINTMENT IS TRANSITION OF DYING MCS OVER WESTERN ILLINOIS THAT SLIDING TO THE EAST-NORTHEAST AND SHOULD ARRIVE IN CENTRAL OH BY AROUND 15Z. EXPECT MAINLY RESIDUAL SHOWERS AT THIS TIME AND BOUNCED POPS BACK INTO CHC CATEGORY FOR SE OH TO ACCOUNT FOR THIS FEATURE. AFOREMENTIONED CONVECTIVE BAND MAY HAVE SOME TROUBLE DEVELOPING IN POST MCS ENVIRONMENT THIS AFTERNOON...BUT ONCE IT GETS GOING...IT SHOULD MAKE A LITTLE MORE HEADWAY INTO THE CWA AS COMPARED TO PREVIOUS BAND FROM YESTERDAY. LONGWAVE TROUGH OVER THE EASTERN US UNDERGOING AMPLIFICATION... WITH 5H FALLS OVER RLX AREA..AND MID LEVEL FLOW BECOMING MORE CYCLONIC. EXPECT A BETTER CHANCE FOR SVR STORMS TODAY UNDER A MODERATELY UNSTABLE ATMOSPHERE AND BETTER SHEAR ENVIRONMENT. MAIN THREAT WILL BE GUSTY WINDS WITH LINE OF STORMS...AND SOME BOWING LINE SEGMENTS. STORMS WILL ALSO BE EFFICIENT PRECIP PRODUCERS WITH PWATS RUNNING 1.5 TO 2.0 INCHES LATER THIS AFTERNOON. KEPT MENTION OF LOCALLY HEAVY DOWNPOURS. WITH THE RECENT DRY CONDITIONS DO NOT SEE WIDESPREAD WATER PROBLEMS. HOWEVER...HEAVY DOWNPOURS COULD CAUSE LOCAL WATER PROBLEMS IF ANY REPETITIVE SHOWERS OCCUR. USED A BLEND OF BIAS CORRECTED DATA WITH PREVIOUS OFFICIAL FORECAST FOR TEMPS WHICH YIELDED A MINOR TWEAK TO THE TEMP FIELDS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... NAM/GFS/ECMWF/CMC MODELS IN AGREEMENT IN THEIR QPF FIELDS PUSHING LAST RAIN SHOWERS OR THUNDERSTORMS TO THE EASTERN MOUNTAINS... MAINLY ACROSS THE SOUTH EARLY WEDNESDAY MORNING. THIS PCPN ACTIVITY IS ASSOCIATED WITH A SECOND COLD FRONT ENHANCED BY A H5 VORTICITY MAXIMA SINKING SOUTHEAST ACROSS THE AREA. BUFKIT SOUNDINGS INDICATE VERY DRY AIR ALOFT BEHIND THIS FRONT. YET ANOTHER H5 VORTICITY MAXIMA MOVES FROM THE NORTHWEST REACHING OUR EXTREME SOUTHEAST COUNTIES WEDNESDAY AFTERNOON. THEREFORE...DECIDED TO KEEP CHANCE POPS UNTIL THEN BEFORE ENDING ALL BY 00Z THURSDAY. TEMPERATURES WILL DEPEND ON THE DURATION OF CLOUD COVER ESPECIALLY WEDNESDAY AND THURSDAY. GENERALLY STAYED IN THE MID 80S LOWLANDS FOR WEDNESDAY...AND FEW DEGREES COOLER THURSDAY AS FLOW TURNS NORTHWEST TO NORTH BY THE AFTERNOON AND EVENING HOURS. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... USED A BLEND OF THE GFS AND ECMWF FOR FRIDAY. THIS LEAVES THE AREA UNDER A HIGH PRESSURE SYSTEM...BUT A BIT OF MOISTURE REMAINS IN THE NORTHERN MOUNTAINS....SO CAN NOT RULE OUT A THUNDERSTORM. FOR SATURDAY THROUGH MONDAY...SWITCHED TO A BLEND OF THE GFS/GEFS ENSEMBLE MEAN AND ECMWF ENSEMBLE MEAN. THIS BRINGS A SYSTEM INTO THE CENTRAL APPALACHIANS OVER THE WEEKEND...LINGERING INTO MONDAY. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... VFR EXPECTED EARLY THIS MORNING. HOWEVER CLOUDS AND SCATTERED CONVECTION WILL BE ON THE INCREASE FROM THE WEST THROUGH ABOUT 16Z. CONVECTION BECOMES MORE WIDESPREAD AFT 16Z AS LINE OF THUNDERSTORMS ARRIVE FROM THE WEST. EXPECT GUSTY WINDS TO ACCOMPANY CONVECTION...ESPECIALLY AFTER 20Z AS NORTH-SOUTH BAND TRAVERSES ACROSS THE FORECAST AREA. EXPECT AT LEAST MVFR CONDITIONS WITH GUSTY WINDS AS BAND PASSES. LOCAL IFR CONDITIONS CAN BE EXPECTED INVOF HEAVIER PRECIPITATION CORES. STORM COVERAGE SHOULD GRADUALLY DECREASE IN COVERAGE ACROSS THE FAR NORTH...SOUTHEAST OHIO...TOWARDS END OF TAF PERIOD. INTRODUCED SOME FOG DEVELOPMENT IN ELEVATED RIVER VALLEYS LATE WEDNESDAY MORNING AS GRADIENTS SLACKEN. BOUNDARY LAYER SHOULD BE PRETTY MOIST FROM PREVIOUS DAYS CONVECTION TO ALLOW FOR MOSTLY MVFR FOG...WITH IFR CONDITIONS AT KEKN FOR A SHORT TIME PERIOD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: MORE WIDESPREAD IFR CONDITIONS DUE TO CONVECTION T0DAY. TIMING AND DENSITY OF FOG DEVELOPMENT WEDNESDAY MORNING MAY VARY CONSIDERABLY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 CRW CONSISTENCY H H H H H H H M M M M M HTS CONSISTENCY H H H H H H H M M M H M BKW CONSISTENCY H H H H H H H H H H H M EKN CONSISTENCY H H H H H H H H H M M H PKB CONSISTENCY H H H H H H H M M H H H CKB CONSISTENCY H H H H H H H M M M M H AFTER 12Z WEDNESDAY... LOCAL IFR IN SHOWERS AND THUNDERSTORMS THROUGH EARLY WEDNESDAY... WITH LINGERING IFR CIGS POSSIBLE THROUGH LATE WEDNESDAY MORNING PARTICULARLY ACROSS HIGHER TERRAIN. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KMC/ARJ NEAR TERM...KMC/26 SHORT TERM...ARJ LONG TERM...RPY AVIATION...KMC
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
613 AM EDT TUE JUL 8 2014 .SYNOPSIS... UNSETTLED WEATHER CONTINUES THROUGH EARLY WEDNESDAY AS A SERIES OF SYSTEMS PUSH EAST. HIGH PRESSURE BRINGS DRIER AIR TO THE REGION FOR THE END OF THE WEEK. ANOTHER SYSTEM OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... UPDATE... MADE SOME MINOR TWEAKS TO POPS FOR EARLY THIS MORNING. OTHERWISE NO CHANGES. PREVIOUS DISCUSSION... CUT BACK POP CHCS FOR THE EARLY MORNING HOURS AS OVERNIGHT CONVECTION DIED OFF RAPIDLY WITH THE LOSS OF DAYTIME HEATING. NEAR TERM HI-RES MODELS RUC13 AND HRRR ARE IN FAIR AGREEMENT IN TRANSITIONING ANOTHER CONVECTIVE BAND ACROSS THE FORECAST AREA THIS AFTERNOON. MAIN FLY IN THE OINTMENT IS TRANSITION OF DYING MCS OVER WESTERN ILLINOIS THAT SLIDING TO THE EAST-NORTHEAST AND SHOULD ARRIVE IN CENTRAL OH BY AROUND 15Z. EXPECT MAINLY RESIDUAL SHOWERS AT THIS TIME AND BOUNCED POPS BACK INTO CHC CATEGORY FOR SE OH TO ACCOUNT FOR THIS FEATURE. AFOREMENTIONED CONVECTIVE BAND MAY HAVE SOME TROUBLE DEVELOPING IN POST MCS ENVIRONMENT THIS AFTERNOON...BUT ONCE IT GETS GOING...IT SHOULD MAKE A LITTLE MORE HEADWAY INTO THE CWA AS COMPARED TO PREVIOUS BAND FROM YESTERDAY. LONGWAVE TROUGH OVER THE EASTERN US UNDERGOING AMPLIFICATION... WITH 5H FALLS OVER RLX AREA..AND MID LEVEL FLOW BECOMING MORE CYCLONIC. EXPECT A BETTER CHANCE FOR SVR STORMS TODAY UNDER A MODERATELY UNSTABLE ATMOSPHERE AND BETTER SHEAR ENVIRONMENT. MAIN THREAT WILL BE GUSTY WINDS WITH LINE OF STORMS...AND SOME BOWING LINE SEGMENTS. STORMS WILL ALSO BE EFFICIENT PRECIP PRODUCERS WITH PWATS RUNNING 1.5 TO 2.0 INCHES LATER THIS AFTERNOON. KEPT MENTION OF LOCALLY HEAVY DOWNPOURS. WITH THE RECENT DRY CONDITIONS DO NOT SEE WIDESPREAD WATER PROBLEMS. HOWEVER...HEAVY DOWNPOURS COULD CAUSE LOCAL WATER PROBLEMS IF ANY REPETITIVE SHOWERS OCCUR. USED A BLEND OF BIAS CORRECTED DATA WITH PREVIOUS OFFICIAL FORECAST FOR TEMPS WHICH YIELDED A MINOR TWEAK TO THE TEMP FIELDS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... NAM/GFS/ECMWF/CMC MODELS IN AGREEMENT IN THEIR QPF FIELDS PUSHING LAST RAIN SHOWERS OR THUNDERSTORMS TO THE EASTERN MOUNTAINS... MAINLY ACROSS THE SOUTH EARLY WEDNESDAY MORNING. THIS PCPN ACTIVITY IS ASSOCIATED WITH A SECOND COLD FRONT ENHANCED BY A H5 VORTICITY MAXIMA SINKING SOUTHEAST ACROSS THE AREA. BUFKIT SOUNDINGS INDICATE VERY DRY AIR ALOFT BEHIND THIS FRONT. YET ANOTHER H5 VORTICITY MAXIMA MOVES FROM THE NORTHWEST REACHING OUR EXTREME SOUTHEAST COUNTIES WEDNESDAY AFTERNOON. THEREFORE...DECIDED TO KEEP CHANCE POPS UNTIL THEN BEFORE ENDING ALL BY 00Z THURSDAY. TEMPERATURES WILL DEPEND ON THE DURATION OF CLOUD COVER ESPECIALLY WEDNESDAY AND THURSDAY. GENERALLY STAYED IN THE MID 80S LOWLANDS FOR WEDNESDAY...AND FEW DEGREES COOLER THURSDAY AS FLOW TURNS NORTHWEST TO NORTH BY THE AFTERNOON AND EVENING HOURS. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... USED A BLEND OF THE GFS AND ECMWF FOR FRIDAY. THIS LEAVES THE AREA UNDER A HIGH PRESSURE SYSTEM...BUT A BIT OF MOISTURE REMAINS IN THE NORTHERN MOUNTAINS....SO CAN NOT RULE OUT A THUNDERSTORM. FOR SATURDAY THROUGH MONDAY...SWITCHED TO A BLEND OF THE GFS/GEFS ENSEMBLE MEAN AND ECMWF ENSEMBLE MEAN. THIS BRINGS A SYSTEM INTO THE CENTRAL APPALACHIANS OVER THE WEEKEND...LINGERING INTO MONDAY. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... VFR EXPECTED EARLY THIS MORNING. HOWEVER CLOUDS AND SCATTERED CONVECTION WILL BE ON THE INCREASE FROM THE WEST THROUGH ABOUT 16Z. CONVECTION BECOMES MORE WIDESPREAD AFT 16Z AS LINE OF THUNDERSTORMS ARRIVE FROM THE WEST. EXPECT GUSTY WINDS TO ACCOMPANY CONVECTION...ESPECIALLY AFTER 20Z AS NORTH-SOUTH BAND TRAVERSES ACROSS THE FORECAST AREA. EXPECT AT LEAST MVFR CONDITIONS WITH GUSTY WINDS AS BAND PASSES. LOCAL IFR CONDITIONS CAN BE EXPECTED INVOF HEAVIER PRECIPITATION CORES. STORM COVERAGE SHOULD GRADUALLY DECREASE IN COVERAGE ACROSS THE FAR NORTH...SOUTHEAST OHIO...TOWARDS END OF TAF PERIOD. INTRODUCED SOME FOG DEVELOPMENT IN ELEVATED RIVER VALLEYS LATE WEDNESDAY MORNING AS GRADIENTS SLACKEN. BOUNDARY LAYER SHOULD BE PRETTY MOIST FROM PREVIOUS DAYS CONVECTION TO ALLOW FOR MOSTLY MVFR FOG...WITH IFR CONDITIONS AT KEKN FOR A SHORT TIME PERIOD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: MORE WIDESPREAD IFR CONDITIONS DUE TO CONVECTION T0DAY. TIMING AND DENSITY OF FOG DEVELOPMENT WEDNESDAY MORNING MAY VARY CONSIDERABLY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22 EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18 CRW CONSISTENCY H H H H H H H H H H M M HTS CONSISTENCY H H H H H H H H H H M M BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H M M CKB CONSISTENCY H H H H H H H H H H M M AFTER 12Z WEDNESDAY... LOCAL IFR IN SHOWERS AND THUNDERSTORMS THROUGH EARLY WEDNESDAY... WITH LINGERING IFR CIGS POSSIBLE THROUGH LATE WEDNESDAY MORNING PARTICULARLY ACROSS HIGHER TERRAIN. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KMC/ARJ NEAR TERM...KMC SHORT TERM...ARJ LONG TERM...RPY AVIATION...KMC
AREA FORECAST DISCUSSION
NWS TULSA OK
1051 AM CDT TUE JUL 8 2014 .DISCUSSION... FRONTAL BOUNDARY IN THE VICINITY OF I-44 FORECAST TO CONTINUE TO DRIFT SOUTH THIS AFTERNOON/TONIGHT THEN STALL LATE TONIGHT BETWEEN I40 AND RED RIVER. LEFT OVER -SHRA FAR NORTHEAST OK FAR NORTHWEST AR DIMINISHING. IN THE SHORT TERM REMOVED NOON - 4PM POPS WHILE LEAVING LATE AFTERNOON POPS NORTH I-40 FOR POTENTIAL REGENERATION THUNDER NEAR BOUNDARY. GW && .PREV DISCUSSION... /ISSUED 638 AM CDT TUE JUL 8 2014/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. GENERALLY VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AT MOST SITES THIS AFTERNOON AND TONIGHT WHICH MAY BRIEFLY REDUCE CEILINGS AND VISIBILITIES. PREV DISCUSSION... /ISSUED 409 AM CDT TUE JUL 8 2014/ DISCUSSION... THE SOUTHWEST PORTION OF A MCS MOVING THROUGH MISSOURI HAD CLIPPED NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS EARLY THIS MORNING. THIS ACTIVITY SHOULD CONTINUE TO PUSH SOUTHEAST AND DISSIPATE OVER THE CWA DURING THE NEXT COUPLE OF HOURS. AN ADDITIONAL LINE OF CONVECTION WAS ACROSS CENTRAL KANSAS...MOVING TO THE SOUTHEAST. WILL LEAVE SLIGHT CHANCE POPS FOR THE MORNING HOURS ACROSS FAR NORTHEAST OKLAHOMA INTO FAR NORTHWEST ARKANSAS. LATEST HRRR AND LOCAL IN-HOUSE MODEL INDICATE THIS LINE TRYING TO FALL APART JUST BEFORE IT GETS INTO THE CWA THIS MORNING. A COLD FRONT CURRENTLY OVER CENTRAL KANSAS WILL MOVE INTO THE CWA TODAY...SHIFTING WINDS OUT OF THE NORTH NORTHEAST. THIS WILL HELP TEMPS ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS BE A LITTLE COOLER COMPARED TO YESTERDAY. CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY FOR THE NORTHERN PART OF THE CWA AS THE FRONT SAGS SOUTHWARD TO NEAR INTERSTATE 40 BY THIS EVENING. AFTERNOON HEATING COULD ALLOW FOR ENOUGH INSTABILITY TO DEVELOP ALONG THE FRONT THAT SOME THUNDERSTORMS COULD BECOME STRONG TO SEVERE WITH LARGE HAIL AND STRONG WINDS BEING THE MAIN HAZARDS. GREATER CHANCES FOR SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS MUCH OF THE CWA TONIGHT INTO WEDNESDAY AS THE FRONT STALLS OUT NEAR THE RED RIVER BY WEDNESDAY MORNING. PERIODS OF HEAVY RAINFALL MAY BE POSSIBLE ALONG WITH A LIMITED SEVERE POTENTIAL. SLIGHTLY COOLER TEMPS WILL AGAIN BE POSSIBLE WEDNESDAY WITH HIGHS IN THE UPPER 80S/LOWER 90S. THE NEARLY STATIONARY FRONTAL BOUNDARY REMAINS OVER THE REGION WEDNESDAY NIGHT INTO THURSDAY AND THEN BEGINS TO LIFT NORTHWARD THURSDAY AS A WARM FRONT. THUS...WILL KEEP AT LEAST SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS GOING THROUGH THURSDAY. A RIDGE OF HIGH PRESSURE BUILDS BACK OVER THE SOUTHERN PLAINS IN THE WAKE OF THE EXITING FRONTAL BOUNDARY AND SHORTWAVE TROF AXIS MOVING ACROSS THE MIDWEST. THIS WILL ALLOW FOR SOUTHERLY WINDS ALONG WITH HOT AND HUMID CONDITIONS TO RETURN TO EASTERN OKLAHOMA AND NORTHWEST ARKANSAS FOR THE WEEKEND. HIGH TEMPS NEAR 100 DEGREES WILL AGAIN BE POSSIBLE FOR PARTS OF EASTERN OKLAHOMA. THESE HOT TEMPS COULD BE SHORT LIVED AS EXTENDED MODEL SOLUTIONS CONTINUE TO SHOW A LOW PRESSURE SYSTEM DROPPING OUT OF CANADA INTO THE GREAT LAKES REGION WITH A COLD FRONT PUSHING ACROSS THE PLAINS FOR THE FIRST PART OF NEXT WEEK. THERE REMAINS TIMING AND STRENGTH DIFFERENCES WITH THIS SYSTEM...THOUGH SOME COOLER TEMPS AND PRECIP CHANCES LOOK POSSIBLE ACROSS THE CWA. && .PRELIMINARY POINT TEMPS/POPS... TUL 93 69 90 71 / 20 30 10 30 FSM 96 72 89 72 / 20 40 30 30 MLC 96 73 91 73 / 10 40 20 30 BVO 90 66 89 69 / 20 20 10 30 FYV 90 66 86 66 / 30 40 10 20 BYV 90 66 86 66 / 30 30 10 20 MKO 95 70 89 71 / 20 30 20 30 MIO 90 65 88 66 / 20 20 10 20 F10 96 71 90 72 / 10 30 20 30 HHW 96 74 93 73 / 10 20 30 30 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...21 LONG TERM....07
AREA FORECAST DISCUSSION
NWS TULSA OK
638 AM CDT TUE JUL 8 2014 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. GENERALLY VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AT MOST SITES THIS AFTERNOON AND TONIGHT WHICH MAY BRIEFLY REDUCE CEILINGS AND VISIBILITIES. && .PREV DISCUSSION... /ISSUED 409 AM CDT TUE JUL 8 2014/ DISCUSSION... THE SOUTHWEST PORTION OF A MCS MOVING THROUGH MISSOURI HAD CLIPPED NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS EARLY THIS MORNING. THIS ACTIVITY SHOULD CONTINUE TO PUSH SOUTHEAST AND DISSIPATE OVER THE CWA DURING THE NEXT COUPLE OF HOURS. AN ADDITIONAL LINE OF CONVECTION WAS ACROSS CENTRAL KANSAS...MOVING TO THE SOUTHEAST. WILL LEAVE SLIGHT CHANCE POPS FOR THE MORNING HOURS ACROSS FAR NORTHEAST OKLAHOMA INTO FAR NORTHWEST ARKANSAS. LATEST HRRR AND LOCAL IN-HOUSE MODEL INDICATE THIS LINE TRYING TO FALL APART JUST BEFORE IT GETS INTO THE CWA THIS MORNING. A COLD FRONT CURRENTLY OVER CENTRAL KANSAS WILL MOVE INTO THE CWA TODAY...SHIFTING WINDS OUT OF THE NORTH NORTHEAST. THIS WILL HELP TEMPS ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS BE A LITTLE COOLER COMPARED TO YESTERDAY. CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY FOR THE NORTHERN PART OF THE CWA AS THE FRONT SAGS SOUTHWARD TO NEAR INTERSTATE 40 BY THIS EVENING. AFTERNOON HEATING COULD ALLOW FOR ENOUGH INSTABILITY TO DEVELOP ALONG THE FRONT THAT SOME THUNDERSTORMS COULD BECOME STRONG TO SEVERE WITH LARGE HAIL AND STRONG WINDS BEING THE MAIN HAZARDS. GREATER CHANCES FOR SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS MUCH OF THE CWA TONIGHT INTO WEDNESDAY AS THE FRONT STALLS OUT NEAR THE RED RIVER BY WEDNESDAY MORNING. PERIODS OF HEAVY RAINFALL MAY BE POSSIBLE ALONG WITH A LIMITED SEVERE POTENTIAL. SLIGHTLY COOLER TEMPS WILL AGAIN BE POSSIBLE WEDNESDAY WITH HIGHS IN THE UPPER 80S/LOWER 90S. THE NEARLY STATIONARY FRONTAL BOUNDARY REMAINS OVER THE REGION WEDNESDAY NIGHT INTO THURSDAY AND THEN BEGINS TO LIFT NORTHWARD THURSDAY AS A WARM FRONT. THUS...WILL KEEP AT LEAST SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS GOING THROUGH THURSDAY. A RIDGE OF HIGH PRESSURE BUILDS BACK OVER THE SOUTHERN PLAINS IN THE WAKE OF THE EXITING FRONTAL BOUNDARY AND SHORTWAVE TROF AXIS MOVING ACROSS THE MIDWEST. THIS WILL ALLOW FOR SOUTHERLY WINDS ALONG WITH HOT AND HUMID CONDITIONS TO RETURN TO EASTERN OKLAHOMA AND NORTHWEST ARKANSAS FOR THE WEEKEND. HIGH TEMPS NEAR 100 DEGREES WILL AGAIN BE POSSIBLE FOR PARTS OF EASTERN OKLAHOMA. THESE HOT TEMPS COULD BE SHORT LIVED AS EXTENDED MODEL SOLUTIONS CONTINUE TO SHOW A LOW PRESSURE SYSTEM DROPPING OUT OF CANADA INTO THE GREAT LAKES REGION WITH A COLD FRONT PUSHING ACROSS THE PLAINS FOR THE FIRST PART OF NEXT WEEK. THERE REMAINS TIMING AND STRENGTH DIFFERENCES WITH THIS SYSTEM...THOUGH SOME COOLER TEMPS AND PRECIP CHANCES LOOK POSSIBLE ACROSS THE CWA. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...05
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
234 PM CDT TUE JUL 8 2014 .SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT SHOWER AND THUNDERSTORM ACTIVITY OCCURRED ACROSS THE NORTH EARLIER TODAY AS A DECAYING MCS MOVED THROUGH CENTRAL MISSOURI. OTHER THAN A STRAY SHOWER OR TWO THIS AFTERNOON...ALL PRECIPITATION FROM THIS FEATURE IS PRETTY MUCH SAID AND DONE. ATTENTION WILL TURN BACK A WEAK COLD FRONT THAT IS ROUGHLY LOCATED FROM NORTHEAST OKLAHOMA THROUGH CENTRAL MISSOURI AND EXTENDING BACK INTO THE OHIO VALLEY. MODELS REMAIN GENERALLY CONSISTENT IN THEIR HANDLING OF A LONG WAVE TROUGH...CLEARLY VISIBLE ON MOISTURE CHANNEL IMAGERY OVER SOUTHERN QUEBEC AT THIS TIME. A SERIES OF UPPER LEVEL IMPULSES WILL HELP TO MOVE THE AFOREMENTIONED FRONT INTO THE STATE. THE HRRR ONCE AGAIN DID A GOOD JOB IN THE VERY NEAR TERM AND ONCE AGAIN THE ECMWF HAS BEEN SLIGHTLY MORE CONSISTENT VERSUS OTHER SHORT TERM MODELS AND THE FORECAST WILL BE TRENDED THIS WAY. AFOREMENTIONED BOUNDARY IS EXPECTED TO DROP INTO THE NORTHERN PART OF THE STATE THIS EVENING AND SAG TO THE SOUTH...REACHING CENTRAL SECTIONS BY MORNING. THERE ARE SOME DIFFERENCES BETWEEN THE MODELS ON WHERE THIS FRONT EVENTUALLY ENDS UP BUT CURRENT THINKING IS IT WILL REACH THE LOUISIANA BORDER LATE WEDNESDAY. AFTER STALLING BRIEFLY THE BOUNDARY WILL LIFT BACK TO THE NORTH AS A WARM FRONT AS RIDGING BEGINS TO GETS REESTABLISHED OVER THE SOUTHERN HIGH PLAINS. PRECIPITATION WILL ACCOMPANY THE BOUNDARY AS IT ADVANCES THROUGH AND THEN BACK OUT OF THE STATE. A WIDESPREAD HEAVY RAIN EVENT IS NOT EXPECTED IN SPITE OF PWATS IN EXCESS OF 1.75 INCHES POOLING ALONG THE BOUNDARY. STILL WITH THIS MUCH MOISTURE IN PLACE...LOCALIZED AMOUNTS IN EXCESS OF AN INCH CAN NEVER BE RULED OUT. TEMPERATURES CONTINUE TO RUN BELOW GUIDANCE AND WITH EXPECTED RAIN AND CLOUD COVER OVER THE NEXT FEW DAYS...WOULD EXPECT THIS CONTINUE. AS SUCH...GUIDANCE WILL BE UNDERCUT A FEW DEGREES. && .LONG TERM...SATURDAY THROUGH TUESDAY... THE INFLUENCE OF THE UPPER RIDGE WILL BEGIN LESSENING OVER THE WEEKEND ACROSS THE NATURAL STATE AS UPPER FLOW TRANSITIONS TO A MORE NWRLY FLOW OVER THE REGION. BEFORE THIS HAPPENS HOWEVER...TEMPS ON SAT WILL REMAIN WELL INTO THE MID AND UPPER 90S...WITH HEAT INDEX VALUES OVER 100 IN MANY SPOTS. EXPECT PRECIP CHANCES TO REMAIN LOW...WITH MAYBE SOME ISOLATED AFTERNOON CONVECTION ON SAT. SUN WILL ALSO REMAIN WARM...BUT COULD SEE A COUPLE DEGREES COOLER ACROSS THE AREA AS HEIGHTS ALOFT BEGIN TO FALL SOME. KEEP FORECAST DRY FOR SUN AS WELL...THOUGH THERE COULD ALSO BE SOME ISOLATED AFTERNOON CONVECTION. BETTER RAIN CHANCES WILL COME EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTH. ALSO HAVE TEMPS COOLING WITH INCREASED PRECIP CHANCES...AND EVEN FROM NRLY FLOW BEHIND THE FRONT AT THE END OF THE FORECAST IF THE FRONT PUSHES FAR ENOUGH SOUTH BY THAT TIME. && .PRELIMINARY POINT TEMPS/POPS... BATESVILLE AR 69 87 67 89 / 50 20 10 10 CAMDEN AR 73 93 72 91 / 30 50 40 30 HARRISON AR 66 87 66 87 / 50 10 10 20 HOT SPRINGS AR 73 91 72 91 / 50 40 30 30 LITTLE ROCK AR 73 90 70 90 / 50 40 20 20 MONTICELLO AR 73 92 72 89 / 30 50 40 20 MOUNT IDA AR 73 91 71 91 / 50 40 30 30 MOUNTAIN HOME AR 65 87 66 87 / 50 10 10 10 NEWPORT AR 70 86 67 89 / 50 20 10 10 PINE BLUFF AR 73 91 72 90 / 40 50 30 20 RUSSELLVILLE AR 71 88 69 89 / 50 30 20 20 SEARCY AR 71 88 68 89 / 50 30 20 20 STUTTGART AR 73 89 70 90 / 50 40 20 20 && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...56 / LONG TERM...62
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
138 PM PDT TUE JUL 8 2014 .SYNOPSIS... HIGH PRESSURE ANCHORED OVER THE FOUR CORNERS REGION WILL KEEP ABOVE NORMAL TEMPERATURES ACROSS THE CENTRAL CALIFORNIA INTERIOR THROUGH MUCH OF THIS WEEK. THERE WILL BE SLIGHT CHANCES OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS OVER THE SIERRA NEVADA THROUGH THURSDAY AS SOME MONSOONAL MOISTURE MOVES INTO THE AREA. && .DISCUSSION...UPPER LEVEL HIGH PRESSURE OVER THE FOUR CORNERS REGION CONTINUED TO PULL MONSOONAL MOISTURE NORTH...NOW EXTENDING INTO OREGON AND EVEN FAR SOUTHERN WASHINGTON STATE. THIS MOISTURE HELPED INITIATE AFTERNOON THUNDERSTORMS ALONG THE SIERRA CREST...MAINLY ALONG THE TULARE/FRESNO COUNTY LINE JUST EAST OF LODGEPOLE. THE HRRR AND NAM DID INDICATE THAT THE HIGHEST INSTABILITY AND MOISTURE WOULD BE NORTH OF WHERE CONVECTION INITIATED YESTERDAY. HOWEVER...THE WITH THE LACK OF INSTABILITY...MU CAPE VALUES BETWEEN 300 AND 400 J/KG...WE DID NOT EXPECT TO SEE AS MANY LIGHTNING STRIKES AS YESTERDAY. THIS HAS NOT BEEN THE CASE SO FAR...AND WE WILL BE WATCHING THE CREST CLOSELY AS THUNDERSTORMS CONTINUE TO DEVELOP AND MORE NORTH. OTHERWISE...SIGNIFICANT DIFFERENCE IN TEMPERATURES COMPARED TO 24 HOURS AGO WITH MOSTLY CLEAR SKIES OVER THE ENTIRE SJ VALLEY. SOUTH OF VISALIA...TEMPERATURES WERE NEARLY IDENTICAL COMPARED TO YESTERDAY AT THIS TIME. HOWEVER...NORTH OF VISALIA TEMPERATURES WERE RUNNING BETWEEN 5 TO 13 DEGREES WARMER COMPARED TO YESTERDAY...WITH MOST VALLEY LOCATIONS ALREADY AT THE CENTURY MARK. TEMPERATURES ARE FORECAST TO RISE ANOTHER 5 OR SO DEGREES BEFORE SUNSET. A VERY SUBTLE COOLING TREND WILL BEGIN TOMORROW AS THE UPPER LEVEL RIDGE OF HIGH PRESSURE OVER FOUR CORNERS BEGINS TO FLATTEN. THIS TREND WILL CONTINUE INTO FRIDAY...WITH EACH DAY COOLING BETWEEN 2 AND 3 DEGREES. BY FRIDAY AFTERNOON...MOST VALLEY LOCATIONS WILL RANGE FROM THE MID TO UPPER 90S...NEAR NORMAL FOR THE MIDDLE OF JULY. THUNDERSTORMS CHANCES WILL MOVE NORTHWARD WEDNESDAY INTO THURSDAY AS MONSOONAL MOISTURE SHIFTS SLIGHTLY NORTH AND EAST. WE WILL CONTINUE TO SEE AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS OVER THE SIERRA CREST ON WEDNESDAY...BUT THURSDAY WILL ONLY SEE A SLIGHT CHANCE MAINLY OVER YOSEMITE. BY FRIDAY...THE UPPER HIGH SHIFTS EAST...SHIFTING OUR MOISTURE SOURCE EAST...CUTTING OFF THUNDERSTORM CHANCES. FORECASTER CONFIDENCE IS MEDIUM TO LOW WITH THE THUNDERSTORM FORECAST AS THE FORECAST MODELS HAVE NOT DONE WELL WITH THE CONVECTIVE SITUATION THE PAST FEW DAYS. THE UPPER RIDGE WILL BEGIN TO BUILD WEST OVER THE REGION SATURDAY INTO THE FIRST PART OF NEXT WEEK...WITH TRIPLE DIGIT TEMPERATURES POSSIBLE ON SUNDAY...BUT MORE LIKELY ON MONDAY. && .AVIATION... LOCAL MVFR/IFR IN MOUNTAIN THUNDERSTORMS THROUGH 02Z WEDNESDAY. OTHERWISE...VFR CONDITIONS WILL PREVAIL OVER THE REGION DURING THE NEXT 24 HOURS. && .AIR QUALITY ISSUES... ON TUESDAY JULY 8 2014... UNHEALTHY FOR SENSITIVE GROUPS IN FRESNO AND KERN COUNTIES AND SEQUOIA NATIONAL PARK AND FOREST. FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG && .CERTAINTY... THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM. THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM. CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL INFORMATION AND/OR TO PROVIDE FEEDBACK. && .CLIMATE... RECORDS SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR KFAT 07-08 115:1905 84:1983 81:1896 51:1891 KFAT 07-09 113:1905 78:1936 81:2008 55:1983 KFAT 07-10 112:2008 81:1974 82:2008 54:1904 KBFL 07-08 114:1905 85:1983 79:1907 50:1899 KBFL 07-09 113:1905 83:1980 84:2008 52:1923 KBFL 07-10 113:1905 82:1936 85:2008 51:1914 && .HNX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ PUBLIC...RILEY AVN/FW...ANDERSEN SYNOPSIS...ANDERSEN WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
340 PM MDT TUE JUL 8 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 339 PM MDT TUE JUL 8 2014 A HOT UPPER LEVEL HIGH REMAINS ANCHORED OVER THE FOUR CORNERS REGION WITH MONSOON MOISTURE FLOWING NORTHWARD UP OVER THE DESERT SOUTHWEST AND GREAT BASIN. SOME OF THIS MOIST AND UNSTABLE SUBTROPICAL AIR HAS WRAPPED AROUND THE TOP OF THIS NEGATIVELY TILTED RIDGE AND OVER SOUTHERN AND WESTERN PORTIONS OF COLORADO AS EVIDENT ON H20 VAPOR SATELLITE IMAGERY. MEANWHILE MID-LEVEL AIR OVER NORTHEAST SECTIONS OF THE STATE HAS DRIED SOME IN THE PAST 12 HOURS...ALTHOUGH SLIGHT COOLING WAS EVIDENT ON RAP AND ACARS SOUNDINGS OVER DENVER DURING THE PAST COUPLE OF HOURS WITH A WEAK THERMAL/SHORTWAVE TROUGH MOVING ALONG IN NORTHWEST FLOW ALOFT. CONVECTION HAS BEEN SLOW TO ORGANIZE TODAY...DUE IN PART TO WARMING ALOFT AS NOTED ABOVE AND THE STABLE POST-FRONTAL AIRMASS EAST OF THE MTNS. MID-LEVEL SUBSIDENCE ON THE BACK SIDE OF THE PASSING SHORTWAVE WAS ALSO OCCURRING OVER NORTHERN PORTIONS OF THE CWA. WHEREAS WEAKLY ASCENDING AIR WITH CONVECTION INHIBITION NEARLY GONE AHEAD OF THE SHORTWAVE COUPLED WITH STEEPENING LAPSE RATES WAS HELPING TO GENERATE SCATTERED SHOWERS/T-STORMS OVER MTN...FOOTHILL AND HIGH PARK AREAS ROUGHLY SOUTH OF I-70 AT THIS HOUR. ONLY A MATTER OF TIME BEFORE SOME OF THIS CONVECTION DRIFTS SOUTHEAST ACROSS THE SOUTHERN URBAN CORRIDOR AND PALMER DIVIDE. LATEST CAPE PLOTS INDICATE VALUES ALREADY IN THE 500-1500 J/KG RANGE OVER THE SOUTHERN FOOTHILLS...SOUTH PARK AND WESTERN SECTIONS OF THE PALMER DIVIDE. IT IS IN THIS AREA THAT THE CHANCE OF STORMS IS GREATEST...IN THE 40-50 PERCENT RANGE. THESE SAME STORMS ARE ALSO MORE LIKELY TO PRODUCE HAIL...BRIEF INTENSE RAINFALL AND GUSTY OUTFLOW WINDS. IS POSSIBLE WE COULD SEE HAIL STONES UPWARDS OF 3/4 INCH IN DIAMETER. IF IT WERE A BIT WARMER...EVEN LARGER THAN THIS. OUT ACROSS THE PLAINS A RELATIVELY COOL AND STABLE POST-FRONTAL AIRMASS HAS PRETTY MUCH CAPPED ANY CONVECTION THIS AFTERNOON. THERE/S ALWAYS A CHANCE THAT AN OUTFLOW BOUNDARY MOVING OUT FROM A T-STORM NEAR THE FOOTHILLS COULD SPARK A STORM OR TWO ON THE PLAINS...BUT THE HRRR...RUC...NAM AND THE NAM NEST AND ARI SYNTHETIC SATELLITE IMAGERY DO NOT INDICATE THIS HAPPENING. WITH THE SHORTWAVE TROUGH PASSING TO THE SOUTHEAST OF THE FORECAST AREA BY EARLY THIS EVENING...SHOULD SEE A MARKED DECREASED IS SHOWER AND STORM ACTIVITY...FAR FROM WHAT HAPPENED LAST EVENING. OVERNIGHT...SHOULD SEE SKIES CLEAR AS A DRIER AND WARMER DEEP LAYER FLOW SETS UP. ON WEDNESDAY...DAY APPEARS TO START OUT DRY WITH WESTERLY MTN TOP FLOW AND A SOUTH-SOUTHWESTERLY FLOW LOWER DOWN. THROUGH THE DAY...SHOULD SEE MOISTURE LEVELS INCREASING AGAIN AS MONSOONAL MOISTURE FLOWS IN FROM UTAH. THIS TIME...THE WEST SLOPE AND HIGHER AREAS UP ALONG THE CONTINENTAL DIVIDE WILL HAVE THE BETTER CHANCE FOR SHOWERS/T-STORMS...SOME POSSIBLY PRODUCE LOCALLY HEAVY RAINFALL AND SMALL HAIL. EAST SLOPE AREAS MAY GET INTO THE ACT BUT NOT UNTIL MID TO LATE AFTERNOON. COULD SEE A FEW STORMS MOVE OFF THE FOOTHILLS AND AS THEY DO PRODUCE OUTFLOW THAT IGNITES ADDITIONAL STORM DEVELOPMENT ON THE PLAINS. AT THIS TIME...STORM COVERAGE ON THE PLAINS DURING THE DAY DOES NOT LOOK MUCH MORE THAN ISOLATED. FINALLY TEMPERATURES ON THE PLAINS WEDNESDAY ARE PROGGED TO BE AS MUCH AS 10-12 DEGS F WARMER THAN TODAY...WITH ONLY SLIGHTLY WARMER TEMPERATURES IN THE HIGH COUNTRY. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 339 PM MDT TUE JUL 8 2014 SOME STORMS WILL BE POSSIBLE WEDNESDAY EVENING...MAINLY ALONG THE FOOTHILLS AND ACROSS THE PALMER DIVIDE WHERE MODELS SHOW CAPES AROUND 500 J/KG. PRECIPITABLE WATER VALUES RANGE FROM 0.70 INCHES ALONG THE FOOTHILLS TO AROUND TO 0.90 INCHES FAR EASTERN PLAINS... WITH 0.60 INCHES ACROSS THE MOUNTAINS. SO...BRIEF HEAVY RAIN WILL BE POSSIBLE WITH SOME OF THE STORMS. AIRMASS STABILIZES BY MIDNIGHT... SO MOST CONVECTION SHOULD END AT THAT TIME. THERE MAY BE A FEW SHOWERS OR STORMS LINGERING FAR EASTERN CORNER AND ACROSS THE HIGHER MOUNTAINS. ON THURSDAY...UPPER LEVEL RIDGE WILL BE OVER COLORADO WITH WEAKER WEST NORTHWEST FLOW ALOFT. WITH CENTER OF THE UPPER HIGH OVER NORTHERN NEW MEXICO...MAIN FLOW OF SUBTROPICAL MOISTURE TO BE ACROSS WESTERN COLORADO AND EASTERN UTAH. STILL SUFFICIENT MOISTURE ACROSS CENTRAL AND EASTERN COLORADO FOR A CHANCE OF THUNDERSTORMS BY THE AFTERNOON WITH THE BEST CHANCE ACROSS THE MOUNTAINS AND FOOTHILLS. PRECIPITABLE WATER VALUES INCREASE TO AROUND 0.70 ACROSS THE MOUNTAINS WITH READINGS RANGING FROM 0.80 ALONG THE FOOTHILLS TO OVER AN INCH FAR EASTERN PLAINS. POTENTIAL FOR STORMS TO PRODUCE BRIEF HEAVY RAIN. FAIRLY LIGHT STEERING WINDS COULD CREATE SOME LOCALIZED FLOODING PROBLEMS. FAIRLY WARM AIRMASS WITH RIDGE OVERHEAD. HIGHS IN THE LOWER AND MIDDLE 90S EXPECTED ACROSS THE PLAINS. FOR FRIDAY...UPPER RIDGE STILL OVER COLORADO WITH FLOW ALOFT MORE WESTERLY. SUBTROPICAL MOISTURE TO CONTINUE TO SPREAD NORTHWARD ACROSS WESTERN COLORADO WITH A BIT MORE MOISTURE OVER EASTERN COLORADO. THIS NOTED BY AN INCREASE IN PRECIPITABLE WATER VALUES...WITH OVER AN INCH ACROSS THE PLAINS. SUFFICIENT MOISTURE FOR A CHANCE OF THUNDERSTORMS DURING THE AFTERNOON AND EVENING. BEST CHANCE OF THUNDERSTORMS TO BE ACROSS THE MOUNTAINS AND FOOTHILLS. MODELS SHOWING A MID LEVEL DISTURBANCE MOVING ACROSS WYOMING DURING THE AFTERNOON AND EVENING. SOME INCREASE IN MID LEVEL ASCENT ACROSS THE NORTHERN BORDER...WHICH MAY HELP INCREASE THE THUNDERSTORM CHANCES NEAR THE WYOMING BORDER. STORMS TO PRODUCE BRIEF HEAVY RAINFALL...BUT APPEARS THERE WILL BE ENOUGH STORM MOTION TO KEEP ANY FLOOD THREAT MINIMAL. AIRMASS STILL FAIRLY WARM WITH HIGHS IN THE LOW AND MIDDLE 90S ACROSS THE PLAINS. ON SATURDAY: RIDGE RETROGRADES SLIGHTLY WITH NORTHWEST FLOW ALOFT ACROSS COLORADO. MAIN BATCH OF SUBTROPICAL MOISTURE MOVES ACROSS UTAH...RESULTING IN A SLIGHT DECREASE IN PRECIPITABLE WATER ACROSS COLORADO. SHOULD SEE LESS THUNDERSTORM ACTIVITY AS A RESULT...WITH THE BEST CHANCE OVER THE MOUNTAINS. AIRMASS COOLER WITH HIGHS IN THE MID 80S ACROSS THE PLAINS. FOR THE LATER DAYS...SUNDAY THROUGH TUESDAY: UPPER RIDGE ACROSS GREAT BASIN SUNDAY WITH NORTHWEST FLOW ALOFT ACROSS COLORADO. BOTH GFS AND ECMWF SHOW THE RIDGE SHIFTING EAST INTO COLORADO MONDAY AND TUESDAY. SUBTROPICAL MOISTURE TO SHIFT EAST INTO WESTERN COLORADO AS A RESULT....BRINGING A BETTER CHANCE FOR AFTERNOON AND EVENING THUNDERSTORMS ALONG WITH SLIGHTLY WARMER TEMPERATURES. && .AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON) ISSUED AT 339 PM MDT TUE JUL 8 2014 ISOLATED T-STORMS ARE EXPECTED TO TRACK SOUTHEAST ACROSS THE DENVER METRO AREA NOW THROUGH 01Z THIS EVENING. THE MAJORITY OF THESE STORMS WILL PRODUCE LITTLE MORE THAN A BRIEF LIGHT TO MODERATE RAINSHOWER...GUSTY ERRATIC OUTFLOW WINDS AND OCCASIONAL CLOUD-TO-GROUND LIGHTNING. HOWEVER STORMS CROSSING SOUTHERN AND WESTERN SECTIONS OF THE METRO AREA HAVE THE POTENTIAL TO PRODUCE SMALL HAIL AND HEAVIER RAINFALL. OVERALL...EAST- SOUTHEAST SURFACE WINDS WILL PREVAIL AT SPEEDS OF 8-14KT THROUGH EARLY EVENING...THEN THE TYPICAL DRAINAGE WIND PATTERN WILL SET UP FOR THE REMAINDER OF THE NIGHT. ON WEDNESDAY...EXPECT SOUTH- SOUTHWESTERLY WINDS UNDER 11 KTS DURING THE MORNING HRS THEN WEST- NORTHWESTERLY AT 8-14KTS IN THE AFTERNOON. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BAKER LONG TERM...D-L AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS ALBANY NY
545 PM EDT TUE JUL 8 2014 .SYNOPSIS... A LINE OF THUNDERSTORMS WILL CROSS OUR REGION FROM WEST TO EAST THIS EVENING...POSSIBLY BRINGING SOME STRONGER WIND GUSTS...HEAVY RAINFALL...HAIL AND FREQUENT CLOUD TO GROUND LIGHTNING. THE COLD FRONT RESPONSIBLE FOR THIS LINE OF STORMS WILL CROSS OUR REGION OVERNIGHT. IT WILL TURN A LITTLE LESS HUMID WEDNESDAY...BUT A SECONDARY COLD FRONT WORKING THROUGH COULD SPARK ADDITIONAL SCATTERED AFTERNOON THUNDERSTORMS. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 545 PM EDT...CONVECTION HAS DIMINISHED ACROSS OUR REGION AS EXPECTED. HOWEVER...TO THE WEST...A BROKEN LINE OF THUNDERSTORMS CONTINUE TO MARCH ACROSS WESTERN INTO CENTRAL NEW YORK STATE. IF THIS LINE HOLDS TOGETHER...AND IT SHOULD AS IT MOVES INTO 2500 JOULES OF INSTABILITY IN OUR REGION...IT WILL REACH OUR WESTERN AREAS BEFORE 900 PM...THE CAPITAL REGION AROUND 900 PM...AND EASTERN AREAS BEFORE MIDNIGHT. WE HAVE ISSUED A SPECIAL WEATHER STATEMENT DISCUSSING THE THREAT FOR DAMAGING WINDS...HEAVY RAINFALL...FREQUENT CLOUD TO GROUND LIGHTNING AND PERHAPS EVEN HAIL. AN UPSTREAM TROUGH CONTINUES TO DIG...THE UPPER LEVEL JETSTREAM WILL INCREASE TO OVER 100KTS AND THE REGION JUST TO OUR WEST WILL COME UNDERNEATH THE BEST JET ENTRANCE REGION...THE LINE WILL LIKELY BECOME BETTER ORGANIZED WITH SOME BOWING SEGMENTS. THE ONLY MITIGATING FACTOR FOR US IS THAT THIS LINE WILL LIKELY NOT ARRIVE UNTIL NEARLY SUNDOWN...THEREBY WE LOOSE SOME HEATING OF THE DAY. HOWEVER...EVEN WITH 1000 OR A LITTLE HIGHER SURFACE BASED CAPES...THAT SHOULD BE SUFFICIENT TO CONTINUE TO ENHANCE THE STORMS GIVEN A SOMEWHAT STRONG A LOW LEVEL JET (UP TO 50 KTS AT H850) AND STRONG UPPER LEVEL DYNAMICS. THE LATEST HRRR MODEL NOW HAS THE SOLID LINE OF STORMS WORKING INTO THE CAPITAL REGION BETWEEN 9-10 PM. BY MIDNIGHT...THE LINE OF STORMS SHOULD BE TO OUR EAST. IN ITS WAKE A COLD FRONT WILL FOLLOW...BRINGING IN SOME DRIER AIR...FIRST ALOFT...EVENTUALLY AT THE SURFACE. THERE MIGHT BE ANOTHER RENEGADE SHOWER OR THUNDERSTORM OVERNIGHT BUT THE LION SHARE OF ACTION WILL BE DONE WITH OVERNIGHT. WE MIGHT HAVE SOME PATCHES OF FOG ESPECIALLY IN AREAS WHERE THE SOUTHWEST BREEZE DIMINISHES AND GROUND IS ESPECIALLY WET FROM HEAVIER SHOWERS. LOOK FOR LOWS STILL ON THE MUGGY SIDE...GENERALLY IN THE 60S. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... ON WEDNESDAY...OUR AREA WILL STILL BE A BROAD CYCLONIC FLOW ALOFT WITH SOMEWHAT DRIER AIR (PWATS UNDER AN INCH) ACROSS OUR REGION TO START THE DAY. WITH A CYCLONIC FLOW ALOFT...AND ONE MORE COLD FRONT TO WORK THROUGH...WE STILL LOOK TO BECOME UNSETTLED ONCE AGAIN BY WEDNESDAY AFTERNOON. THERE WILL BE JUST ENOUGH INSTABILITY WITH A LITTLE MOISTURE RELOADING THAT COULD TRIGGER ANOTHER ROUND OF SCATTERED AFTERNOON THUNDERSTORMS. INSTABILITY LOOKS TO INCREASE TO ABOUT 1500 J/KG WITH LAPSE RATES UP TO 6.5 C/KM. THERE WILL ALSO BE A BRISK LOW LEVEL WIND OUT OF THE SOUTHWEST AROUND 40KTS. THUNDERSTORMS ON WEDNESDAY COULD AT THE VERY LEAST PRODUCE SOME SMALL HAIL AND GUSTY WINDS. FOR NOW...WE DID NOT INCLUDE ENHANCED WORKING IN THE GRIDS SINCE THE CONFIDENCE OF STORMS IN ONLY IN THE 30 PERCENT RANGE. HIGH TEMPERATURES ON WEDNESDAY WILL BE 80-85 HIGHER TERRAIN...75-80 ACROSS THE HIGHER TERRAIN. THE SURFACE WIND WILL BE SOUTH TO SOUTHWEST 10-15 MPH...SHIFTING TO WEST BY LATE IN THE DAY BEHIND THE COLD FRONT. ANY THUNDERSTORMS SHOULD QUICKLY DIMINISH BY WEDNESDAY EVENING. AFTER THAT IT WILL CLEAR OUT...TURNING A LITTLE COOLER AND DRIER WITH LOWS GENERALLY DIPPING INTO THE 50S. THURSDAY LOOKS LIKE A NICE WITH LOTS OF SUNSHINE...COMFORTABLE HUMIDITY (DEWPOINTS IN THE 50S) AND HIGHS AROUND 80 IN THE VALLEYS...70S HIGHER TERRAIN. THURSDAY NIGHT LOOKS CLEAR AND COOL. LOWS BACK INTO THE 50S ALBANY SOUTHWARD...MID TO UPPER 40S WELL NORTH OF THE CAPITAL REGION. FRIDAY LOOKS LIKE A NICE DAY WITH LOTS OF SUNSHINE AND CONTINUED LOWER HUMIDITY. HIGHS WILL BE 80-85 VALLEYS...75-80 HIGHER TERRAIN. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... TRANQUIL WEATHER IS EXPECTED TO CONTINUE THROUGH SATURDAY AS WARM ADVECTION INCREASES AND TEMPERATURES REACH HIGHS IN THE 80S...SOME UPPER 70S IN HIGHER TERRAIN. LOW LEVEL MOISTURE INCREASES LATER IN THE WEEKEND AND SOME FORCING ASSOCIATED WITH AN ADVANCING WARM FRONT COULD SUPPORT ISOLATED TO SCATTERED THUNDERSTORMS SATURDAY NIGHT THROUGH SUNDAY. HIGHS SUNDAY ARE EXPECTED TO BE IN THE 80S...WITH MID TO UPPER 70S IN HIGHER TERRAIN. BY SUNDAY NIGHT THROUGH TUESDAY...SOME UPPER ENERGY TRACKING SOUTHEAST OUT OF CANADA AND ITS ASSOCIATED COLD FRONT WILL APPROACH WITH INCREASING COVERAGE OF SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD AS PREFRONTAL TROUGH TYPE CONVECTION INCREASES IN THE REGION. HIGHS MONDAY IN THE 80S...WITH MID TO UPPER 70S IN HIGHER TERRAIN. HIGHS TUESDAY IN THE MID 70S TO LOWER 80S. AT THIS TIME...LONG RANGE GUIDANCE SUGGESTS A FRONTAL PASSAGE LATE TUESDAY BUT AS ALWAYS THE TIMING COULD CHANGE AS WE GET CLOSER. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... A LINE OF THUNDERSTORMS WILL LIKELY IMPACT THE TERMINALS BETWEEN 01Z AND 03Z WITH HEAVY RAINFALL...GUSTY WINDS...FREQUENT LIGHTNING AND POSSIBLE HAIL. AS OF 2150Z...DIURNAL CONVECTION HAS DIMINISHED SO WE REMOVED THE VCSH THROUGH 00Z. CONDITIONS WILL REMAIN VFR. THEN...A LINE OF SHOWERS AND THUNDERSTORMS WILL MOVE TOWARD THE TAF SITES AROUND 01Z. WE ARE CONFIDENT ENOUGH TO PLACE VCTS/THUNDER IN THE TAFS BETWEEN 01Z-04Z. FOR NOW WE CAPPED WINDS AT VRB25KT...BUT THEY COULD GUST STRONGER THAN THAT. WE KEPT CONDITIONS AT THE HIGH END OF MVFR...BUT BRIEF IFR CONDITIONS ARE POSSIBLE. THE LINE LOOKS TO MOVE EAST BY 04Z. AFTER THAT...A COLD FRONT WILL PASS...SHIFTING THE WIND AND ALLOWING FOR SLOW DRYING. THE DILEMMA IS HOW FAST THIS DRYING ARRIVES. FOR NOW...WE DID PLACE MVFR CIGS IN ALL THE TAFS (LOW MVFR AT KPSF) AND MVFR MIST AT KGFL/KPSF. VFR CONDITIONS SHOULD PREVAIL AFTER THE MORNING PEAK THROUGH THE END OF THE TAF PERIOD. THE WIND WILL BE SW OR WEST AROUND 10KTS. THERE IS A CHANCE OF ADDITIONAL THUNDERSTORMS WEDNESDAY AFTERNOON...BUT THE CHANCE WAS TOO LOW (JUST UNDER 30 PERCENT) TO PLACE IN THE TAFS AT THIS TIME. OUTLOOK... WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. THURSDAY THROUGH SATURDAY NIGHT: NO OPERATIONAL IMPACT. SUNDAY: MODERATE OPERATIONAL IMPACT. CHC OF SHRA/TSRA. && .FIRE WEATHER... A LINE OF THUNDERSTORMS WILL CROSS OUR REGION THIS EVENING WITH A LEAST A QUARTER INCH OR MORE OF RAINFALL ACROSS THE ENTIRE REGION. HOWEVER...SINCE THE RAIN WILL FALL FOR ONLY A SHORT DURATION AND AT NIGHT...DID NOT ASSIGN A WET FLAG TO OUR NFDRS. DRIER WEATHER ON WEDNESDAY WITH RH VALUES DIPPING INTO THE 40S. HOWEVER...MOSE SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED BUT NOT EVERYONE WILL LIKELY RECEIVE THEM. DRY WEATHER EXPECTED THURSDAY NIGHT THROUGH SATURDAY NIGHT WITH THE USUAL NEARLY FULL RECOVER (AND SOME DEW) AT NIGHT...AND SEASONABLE AFTER RH HUMIDITIES IN THE 30S TO 40 EACH AFTERNOON. THE CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS TO BE SUNDAY PERSISTING INTO EARLY NEXT WEEK. THE SURFACE WIND WILL BE SOUTH TO SOUTHWEST TONIGHT 5-15 MPH WITH HIGHER GUSTS...SOUTHWEST TO WEST AT SIMILAR SPEEDS WEDNESDAY...BECOMING NORTHWESTERLY AT 5-15 MPH ON THURSDAY AND FRIDAY. && .HYDROLOGY... A LINE OF THUNDERSTORMS AND SHOWERS WILL HEAD ACROSS OUR REGION THIS EVENING. WHILE OVER AVERAGE RAINFALL BASINS WILL UNDER AN INCH...LOCALIZED MUCH HIGHER AMOUNTS ARE POSSIBLE...POSSIBLY LOCALLY EXCEEDING TWO INCHES. THERE IS A POTENTIAL FOR LOCALIZED FLASH FLOODING BUT NOT ENOUGH AREA TO CONSIDER A FLASH FLOOD WATCH YET. SOMEWHAT DRIER AIR WILL MOVE INTO TOMORROW...BUT THE AIR MASS LOOKS TO BE REMAIN UNSTABLE FOR ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY AFTERNOON. AT THIS POINT...WE DO NOT EXPECT ANY SIGNIFICANT HYDRO PROBLEMS OTHER THAN THE USUAL LOCALIZED PONDING OF WATER ON SOME ROADS AND AREAS OF POOR DRAINAGE. DRY WEATHER THURSDAY THROUGH SATURDAY. THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE ON SUNDAY AFTERNOON. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...HWJIV NEAR TERM...HWJIV SHORT TERM...HWJIV LONG TERM...NAS AVIATION...HWJIV FIRE WEATHER...HWJIV HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS JACKSON KY
454 PM EDT TUE JUL 8 2014 .MESOSCALE UPDATE... ISSUED AT 454 PM EDT TUE JUL 8 2014 STORMS CONTINUE TO HAVE A HARD TIME ORGANIZING. UPDRAFTS DO NOT APPEAR TO BE ABLE TO MUSTER ENOUGH STRENGTH TO OVERCOME SOME WARM AIR BETWEEN 400 AND 500 MB. MODEL SOUNDINGS DO NOT SHOW THIS WARM LAYER GOING AWAY. AN ISOLATED SEVERE THUNDERSTORM WITH GUSTY WINDS CANNOT BE RULED OUT INTO THE EVENING...BUT SEVERE THREAT APPEARS TO BE DWINDLING. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 258 PM EDT TUE JUL 8 2014 STORMS HAVE BEEN A LITTLE SLOW TO DEVELOP OVER EAST KENTUCKY DUE TO PERSISTENT CLOUD COVER...BUT BREAKS ARE DEVELOPING IN THE CLOUDS AND STORMS SHOULD RESPOND TO THIS AND THE APPROACHING COLD FRONT AND IGNITE OVER THE NEXT COUPLE OF HOURS. HRRR HAS BEEN ADAMANT THAT STORMS WILL BE SCATTERED AT BEST OVER OUR AREA...BUT LATEST RAP MAKES A LITTLE MORE SENSE CONSIDERING THE ENVIRONMENT. IT DEVELOPS CONVECTION OVERHEAD AND THEN TO OUR NORTHWEST AND WEST WITH THE FRONT. THIS CONVECTION THEN MOVES OVER US INTO THE EVENING...WITH THE UPPER CUMBERLAND REGION LOOKING TO TAKE THE BRUNT OF THE ACTIVITY. FORECAST WAS TRENDED IN THIS DIRECTION AND DID LOWER POPS A BIT...ESPECIALLY IN THE NORTH BASED ON MODEL DATA. WILL CONTINUE TO ADVERTISE THE SEVERE THREAT THROUGH THE EVENING. THE FRONT WILL HANG UP OVER SOUTHEAST KENTUCKY ON WEDNESDAY. CLOUD COVER MAY BE SLOW TO ERODE AGAIN...BUT MODELS INDICATE STEEPENING LAPSE RATES DEVELOPING DURING THE DAY WITH ADEQUATE CAPE TO POP OFF AN ISOLATED SHOWER OR STORM JUST ABOUT ANYWHERE AS TEMPS RISE AGAIN INTO THE 80S. THIS THREAT WILL END QUICKLY EARLY IN THE EVENING WITH THE LOSS OF DAYTIME HEATING AND EXPECT DECREASING CLOUDS WEDNESDAY NIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 300 PM EDT TUE JUL 8 2014 THE MODELS WERE IN PRETTY GOOD AGREEMENT IN THE EXTENDED THIS TIME AROUND. THE 12Z RUN OF THE ECMWF WAS COMING MUCH MORE INTO LINE WITH THE GFS MODEL...WITH A DRY START TO THE PERIOD AS HIGH PRESSURE GRADUALLY DRIFTS OFF TO THE SOUTHEAST TOWARD THE END OF THE WEEK. THE CONSENSUS VIEW IS NOW FOR A VIGOROUS AREA OF UPPER LEVEL LOW PRESSURE TO MOVE ACROSS THE UPPER GREAT LAKES SOUTHERN CANADA AREA...PARTICULARLY OVER THE UPCOMING WEEKEND. THE TROUGH LOOKS TO BE AT ITS MOST POTENT FROM SUNDAY ONWARD...AS IT DIPS SOUTH OUT OF CANADA AND INTO THE NORTH CENTRAL CONUS TO BEGIN THE WORK WEEK NEXT WEEK. THE BULK OF THE EXTENDED LOOKS TO BE DRY AT THIS POINT...WITH THE ANTICIPATED PATTERN LENDING ITSELF TO MORE MOIST AND ACTIVE PERIOD AND RAIN CHANCES FROM SUNDAY ONWARD. TEMPERATURES THROUGHOUT THE PERIOD SHOULD BE AT OR SLIGHTLY BELOW NORMAL...WITH THE COOLER DAY TIME HIGHS OCCURRING SUNDAY AND MONDAY AS CLOUD COVER AND PRECIPITATION BEGIN OVERSPREADING THE AREA. THE START OF THE PERIOD LOOKS TO BE MORE WARM AND HUMID. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 145 PM EDT TUE JUL 8 2014 THUNDERSTORMS ARE THE MAIN CONCERN THROUGH THE EVENING AND CONFIDENCE IS LOW ON THE EXACT TIMING AND IMPACTS AT ANY GIVEN LOCATION. GUSTY WINDS WILL ALSO BE A HINDRANCE BUT ARE EXPECTED TO DIE DOWN BY SUNSET. EXPECT STORMS TO DEVELOP OVER EASTERN KENTUCKY THROUGH MID AFTERNOON AND MOVE EASTWARD. TEMPO IFR CONDITIONS WITH GUSTY WINDS ARE LIKELY WHERE STORMS HIT. ADDITIONAL STORMS WILL LIKELY DEVELOP TO OUR WEST AND CONTINUE TO IMPACT AREA TERMINALS...PARTICULARLY FROM JKL SOUTH...INTO THE EVENING HOURS. THIS THREAT WILL DIMINISH FROM NORTH TO SOUTH OVERNIGHT. MODELS INDICATE A POTENTIAL FOR A PERIOD OF LOW CEILINGS TO DEVELOP LATE TONIGHT AND LAST INTO WEDNESDAY MORNING. WILL ADVERTISE AN MVFR CEILING OCCURRING AT TAF SITES AFTER 08Z AND LASTING UNTIL APPROXIMATELY 15Z...WITH VFR CONDITIONS ANTICIPATE THEREAFTER. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE...ABE SHORT TERM...ABE LONG TERM...AR AVIATION...ABE
AREA FORECAST DISCUSSION
NWS JACKSON KY
300 PM EDT TUE JUL 8 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 258 PM EDT TUE JUL 8 2014 STORMS HAVE BEEN A LITTLE SLOW TO DEVELOP OVER EAST KENTUCKY DUE TO PERSISTENT CLOUD COVER...BUT BREAKS ARE DEVELOPING IN THE CLOUDS AND STORMS SHOULD RESPOND TO THIS AND THE APPROACHING COLD FRONT AND IGNITE OVER THE NEXT COUPLE OF HOURS. HRRR HAS BEEN ADAMANT THAT STORMS WILL BE SCATTERED AT BEST OVER OUR AREA...BUT LATEST RAP MAKES A LITTLE MORE SENSE CONSIDERING THE ENVIRONMENT. IT DEVELOPS CONVECTION OVERHEAD AND THEN TO OUR NORTHWEST AND WEST WITH THE FRONT. THIS CONVECTION THEN MOVES OVER US INTO THE EVENING...WITH THE UPPER CUMBERLAND REGION LOOKING TO TAKE THE BRUNT OF THE ACTIVITY. FORECAST WAS TRENDED IN THIS DIRECTION AND DID LOWER POPS A BIT...ESPECIALLY IN THE NORTH BASED ON MODEL DATA. WILL CONTINUE TO ADVERTISE THE SEVERE THREAT THROUGH THE EVENING. THE FRONT WILL HANG UP OVER SOUTHEAST KENTUCKY ON WEDNESDAY. CLOUD COVER MAY BE SLOW TO ERODE AGAIN...BUT MODELS INDICATE STEEPENING LAPSE RATES DEVELOPING DURING THE DAY WITH ADEQUATE CAPE TO POP OFF AN ISOLATED SHOWER OR STORM JUST ABOUT ANYWHERE AS TEMPS RISE AGAIN INTO THE 80S. THIS THREAT WILL END QUICKLY EARLY IN THE EVENING WITH THE LOSS OF DAYTIME HEATING AND EXPECT DECREASING CLOUDS WEDNESDAY NIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 300 PM EDT TUE JUL 8 2014 THE MODELS WERE IN PRETTY GOOD AGREEMENT IN THE EXTENDED THIS TIME AROUND. THE 12Z RUN OF THE ECMWF WAS COMING MUCH MORE INTO LINE WITH THE GFS MODEL...WITH A DRY START TO THE PERIOD AS HIGH PRESSURE GRADUALLY DRIFTS OFF TO THE SOUTHEAST TOWARD THE END OF THE WEEK. THE CONSENSUS VIEW IS NOW FOR A VIGOROUS AREA OF UPPER LEVEL LOW PRESSURE TO MOVE ACROSS THE UPPER GREAT LAKES SOUTHERN CANADA AREA...PARTICULARLY OVER THE UPCOMING WEEKEND. THE TROUGH LOOKS TO BE AT ITS MOST POTENT FROM SUNDAY ONWARD...AS IT DIPS SOUTH OUT OF CANADA AND INTO THE NORTH CENTRAL CONUS TO BEGIN THE WORK WEEK NEXT WEEK. THE BULK OF THE EXTENDED LOOKS TO BE DRY AT THIS POINT...WITH THE ANTICIPATED PATTERN LENDING ITSELF TO MORE MOIST AND ACTIVE PERIOD AND RAIN CHANCES FROM SUNDAY ONWARD. TEMPERATURES THROUGHOUT THE PERIOD SHOULD BE AT OR SLIGHTLY BELOW NORMAL...WITH THE COOLER DAY TIME HIGHS OCCURRING SUNDAY AND MONDAY AS CLOUD COVER AND PRECIPITATION BEGIN OVERSPREADING THE AREA. THE START OF THE PERIOD LOOKS TO BE MORE WARM AND HUMID. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 145 PM EDT TUE JUL 8 2014 THUNDERSTORMS ARE THE MAIN CONCERN THROUGH THE EVENING AND CONFIDENCE IS LOW ON THE EXACT TIMING AND IMPACTS AT ANY GIVEN LOCATION. GUSTY WINDS WILL ALSO BE A HINDRANCE BUT ARE EXPECTED TO DIE DOWN BY SUNSET. EXPECT STORMS TO DEVELOP OVER EASTERN KENTUCKY THROUGH MID AFTERNOON AND MOVE EASTWARD. TEMPO IFR CONDITIONS WITH GUSTY WINDS ARE LIKELY WHERE STORMS HIT. ADDITIONAL STORMS WILL LIKELY DEVELOP TO OUR WEST AND CONTINUE TO IMPACT AREA TERMINALS...PARTICULARLY FROM JKL SOUTH...INTO THE EVENING HOURS. THIS THREAT WILL DIMINISH FROM NORTH TO SOUTH OVERNIGHT. MODELS INDICATE A POTENTIAL FOR A PERIOD OF LOW CEILINGS TO DEVELOP LATE TONIGHT AND LAST INTO WEDNESDAY MORNING. WILL ADVERTISE AN MVFR CEILING OCCURRING AT TAF SITES AFTER 08Z AND LASTING UNTIL APPROXIMATELY 15Z...WITH VFR CONDITIONS ANTICIPATE THEREAFTER. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ABE LONG TERM...AR AVIATION...ABE
AREA FORECAST DISCUSSION
NWS JACKSON KY
258 PM EDT TUE JUL 8 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 258 PM EDT TUE JUL 8 2014 STORMS HAVE BEEN A LITTLE SLOW TO DEVELOP OVER EAST KENTUCKY DUE TO PERSISTENT CLOUD COVER...BUT BREAKS ARE DEVELOPING IN THE CLOUDS AND STORMS SHOULD RESPOND TO THIS AND THE APPROACHING COLD FRONT AND IGNITE OVER THE NEXT COUPLE OF HOURS. HRRR HAS BEEN ADAMANT THAT STORMS WILL BE SCATTERED AT BEST OVER OUR AREA...BUT LATEST RAP MAKES A LITTLE MORE SENSE CONSIDERING THE ENVIRONMENT. IT DEVELOPS CONVECTION OVERHEAD AND THEN TO OUR NORTHWEST AND WEST WITH THE FRONT. THIS CONVECTION THEN MOVES OVER US INTO THE EVENING...WITH THE UPPER CUMBERLAND REGION LOOKING TO TAKE THE BRUNT OF THE ACTIVITY. FORECAST WAS TRENDED IN THIS DIRECTION AND DID LOWER POPS A BIT...ESPECIALLY IN THE NORTH BASED ON MODEL DATA. WILL CONTINUE TO ADVERTISE THE SEVERE THREAT THROUGH THE EVENING. THE FRONT WILL HANG UP OVER SOUTHEAST KENTUCKY ON WEDNESDAY. CLOUD COVER MAY BE SLOW TO ERODE AGAIN...BUT MODELS INDICATE STEEPENING LAPSE RATES DEVELOPING DURING THE DAY WITH ADEQUATE CAPE TO POP OFF AN ISOLATED SHOWER OR STORM JUST ABOUT ANYWHERE AS TEMPS RISE AGAIN INTO THE 80S. THIS THREAT WILL END QUICKLY EARLY IN THE EVENING WITH THE LOSS OF DAYTIME HEATING AND EXPECT DECREASING CLOUDS WEDNESDAY NIGHT. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 400 AM EDT TUE JUL 8 2014 THE MODELS START OUT IN VERY GOOD AGREEMENT WITH AN UPPER TROUGH AXIS JUST TO THE EAST OF THE AREA AND SURFACE HIGH PRESSURE BUILDING INTO THE AREA FROM THE NORTHWEST. THE COLD FRONT WILL BE WELL SOUTH AND EAST OF THE AREA. ON THURSDAY...A SHORT WAVE WILL MOVE ACROSS THE AREA AND MAY KICK UP SOME SHOWERS SOUTH OF THE HAL ROGERS PARKWAY. THE LATEST ECMWF KEPT THINGS DRY...SO THIS MAY BE TAKEN OUT OF THE FORECAST BY DAY SHIFT. FRIDAY SHOULD STAY DRY AND THEN ON SATURDAY...A COLD FRONT WILL BE MOVING INTO THE AREA FROM THE NORTHWEST. EASTERN KENTUCKY WILL BE IN WARM SECTOR OUT AHEAD OF THE FRONT AND THIS WILL BE THE START OF AN UNSETTLED PERIOD THAT WILL CONTINUE THROUGH MONDAY WHEN THE FRONT WILL FINALLY MOVE SOUTH AND EAST OF THE AREA. THE MODELS STAY IN GOOD GENERAL AGREEMENT THROUGH THE END OF THE PERIOD...HOWEVER THERE ARE ENOUGH NUANCES THAT THE CONFIDENCE IN THE TIMING OF THE WEEKEND AND BEYOND STARTS TO TAPER OFF. USED THE MODEL BLEND FOR THE TEMPERATURES AND THEN MADE SOME CORRECTIONS BASED ON ELEVATION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 145 PM EDT TUE JUL 8 2014 THUNDERSTORMS ARE THE MAIN CONCERN THROUGH THE EVENING AND CONFIDENCE IS LOW ON THE EXACT TIMING AND IMPACTS AT ANY GIVEN LOCATION. GUSTY WINDS WILL ALSO BE A HINDRANCE BUT ARE EXPECTED TO DIE DOWN BY SUNSET. EXPECT STORMS TO DEVELOP OVER EASTERN KENTUCKY THROUGH MID AFTERNOON AND MOVE EASTWARD. TEMPO IFR CONDITIONS WITH GUSTY WINDS ARE LIKELY WHERE STORMS HIT. ADDITIONAL STORMS WILL LIKELY DEVELOP TO OUR WEST AND CONTINUE TO IMPACT AREA TERMINALS...PARTICULARLY FROM JKL SOUTH...INTO THE EVENING HOURS. THIS THREAT WILL DIMINISH FROM NORTH TO SOUTH OVERNIGHT. MODELS INDICATE A POTENTIAL FOR A PERIOD OF LOW CIELINGS TO DEVELOP LATE TONIGHT AND LAST INTO WEDNESDAY MORNING. WILL ADVERTISE AN MVFR CEILING OCCURRING AT TAF SITES AFTER 08Z AND LASTING UNTIL APPROXIMATELY 15Z...WITH VFR CONDITIONS ANTICIPATE THEREAFTER. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ABE LONG TERM...JJ AVIATION...ABE
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
331 PM CDT TUE JUL 8 2014 .DISCUSSION... AN UPPER LEVEL TROUGH IS IN THE PROCESS OF DIGGING SOUTHWARD ACROSS THE GREAT LAKES AND OHIO RIVER VALLEY TODAY AND WILL CONTINUE TO PROTRUDE FURTHER SOUTH AS IT PROGRESSES EAST. AT THE SAME TIME... MOISTURE HAS BEEN BACK ON THE INCREASE IN THE MID AND UPPER LEVELS. THIS MORNING/S AT LIX SHOWED A PRECIP WATER VALUE OF NEAR 1.5 INCHES AND MODEL SOUNDINGS INDICATE THAT THIS VALUE COULD BE NEAR 2 INCHES BY THE 00Z FLIGHT. SO ITS NO SURPRISE THAT QUITE A BIT OF CONVECTION HAS DEVELOPED TODAY. THE HRRR HAS DONE A PRETTY DECENT JOB OF INITIALIZING AND KEEPING UP WITH THE CURRENT RADAR TRENDS. ITS DEPICTION OF DIMINISHING ACTIVITY BY SUNSET AGREES WELL WITH TYPICAL EXPECTATIONS OF STORM DISSIPATION WITH LOSS OF DAYTIME HEATING. A WEAK COLD FRONT ASSOCIATED WITH THIS UPPER LEVEL TROUGH WILL GRADUALLY SAG CLOSER AND CLOSER TO THE AREA AS WE APPROACH THE WEEKEND. IT APPEARS THAT THE BOUNDARY WILL EVENTUALLY REACH THE CWA BUT WILL BE IN A NEARLY INDISCERNIBLE STATE. LOCAL WEATHER CONDITIONS FROM TODAY THROUGH THE WEEKEND WILL NOT BE VERY DIFFERENT FROM DAY TO DAY. DAYTIME POPS SHOULD GENERALLY BE AROUND 30-50 PERCENT WITH A PEAK OF 60 PERCENT ON THURSDAY. NOCTURNAL OFFSHORE SHOWERS POSSIBLE AS WELL. TEMPERATURES THROUGH THIS PERIOD WILL BE NEAR NORMAL. MEFFER && .AVIATION... MOISTURE RETURN HAS TRIGGERED SCATTERED CONVECTION THAT CONTINUES TO DEVELOP THIS AFTERNOON. WHILE MOST TERMINALS ARE VFR...CONVECTION WILL PRODUCE BRIEF IFR CONDITIONS AS THEY AFFECT TERMINALS. CARRYING VCTS WITH TEMPO IFR AS APPROPRIATE OVER THE NEXT 3-4 HOURS. CONVECTION SHOULD DIMINISH AS WE APPROACH SUNSET. VFR CONDITIONS WILL BE THE RULE OVERNIGHT...WITH CONVECTIVE DEVELOPMENT AGAIN ANTICIPATED ON WEDNESDAY BY LATE MORNING TO EARLY AFTERNOON. 35 && .MARINE... A BRIEF NOCTURNAL MAX OF 10 TO 15 KNOTS IN THE NEARSHORE WATERS OF LA AND MS ARE EXPECTED TONIGHT AND TOMORROW NIGHT AS A WEAK SURFACE TROUGH TO THE NORTH TIGHTENS THE PRESSURE GRADIENT. OTHERWISE... RELATIVELY LIGHT WIND AND WAVE CONDITIONS ARE EXPECTED TO PREVAIL THROUGH MOST OF THE UPCOMING WEEK DUE TO A RIDGE OF HIGH PRESSURE OVER THE REGION. SCATTERED CONVECTION WILL CONTINUE TO BE A THREAT THROUGH THE FORECAST PERIOD. 35 && .DECISION SUPPORT... DSS CODE...GREEN. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...NONE. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE. && .PRELIMINARY POINT TEMPS/POPS... MCB 71 92 71 92 / 20 40 20 60 BTR 73 92 73 92 / 30 40 10 50 ASD 73 92 74 92 / 20 40 20 60 MSY 76 92 76 91 / 30 40 10 50 GPT 76 91 77 91 / 20 40 20 50 PQL 72 91 73 91 / 20 40 30 50 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 PM EDT TUE JUL 8 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 425 PM EDT TUE JUL 8 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A RIDGE OVER WRN NAMERICA AND A DOWNSTREAM TROF WITH AXIS EXTENDING FROM NCNTRL CANADA INTO THE GREAT LAKES. ONE VIGOROUS SHORTWAVE MOVING THRU THE TROF BROUGHT SHRA AND SOME TSRA TO MUCH OF THE FCST AREA LAST NIGHT INTO THE MORNING HRS. THAT WAVE IS NOW E OF LAKE SUPERIOR. UPSTREAM...THERE ARE A PAIR OF SHORTWAVES...ONE NEAR LAKE WINNIPEG AND THE OTHER JUST TO THE E IN NRN ONTARIO. NEITHER ARE AS STRONG AS THE ONE THAT AFFECTED THE AREA EARLIER TODAY. THE WAVE NEAR LAKE WINNIPEG IS THE STRONGER OF THE TWO AND WILL BE THE MAIN PLAYER IN THE WEATHER HERE TONIGHT. IN THE WAKE OF THE SHORTWAVE THAT PASSED EARLIER TODAY... CLOUDS HAVE HELD TOUGH ACROSS MUCH OF THE AREA...AND THIS HAS RESULTED IN A VERY COOL DAY FOR EARLY JULY STANDARDS. AS OF 19Z... READINGS WERE STILL ONLY HOVERING AROUND 50F NEAR LAKE SUPERIOR AND AROUND 60/LWR 60S ACROSS SCNTRL UPPER MI. SO FAR...TEMP HAS ONLY REACHED 54F HERE AT THE NWS OFFICE. RECORD LOW MAX TEMP FOR TODAY IS 60F. IF LOW STRATUS HANGS AROUND THRU SUNSET...THAT RECORD WILL FALL. WHERE CLOUDS HAVE BROKEN TO ALLOW FOR SUNSHINE FROM NE MN INTO NRN WI...BUILD UP OF A LITTLE INSTABILITY UNDER COOL CYCLONIC NW FLOW COMBINED WITH A SUBTLE SHORTWAVE HAS ALLOWED -SHRA/ISOLD TSRA TO DEVELOP. THOSE SHRA HAVE BEEN BRUSHING MENOMINEE COUNTY. OTHERWISE...ISOLD -SHRA/PATCHY -DZ HAVE BEEN OCCURRING ACROSS THE AREA TODAY. ISOLD -SHRA MAY LINGER NEAR THE WI/MI BORDER INTO THE EARLY EVENING HRS. OTHERWISE...ATTENTION TURNS TO THE NW. ALTHOUGH UPSTREAM SHORTWAVES WILL BE PASSING ACROSS THE UPPER LAKES DURING THE NIGHT WHEN INSTABILITY IS DIMINISHING TOWARD DIURNAL MIN...EXPECT SOME SHRA TO PERSIST NEAR THE TRACK OF THE WAVES...PARTICULARLY NEAR THE AFORMENTIONED STRONGER WRN WAVE. THIS SHOULD PUT BEST POTENTIAL FOR ISOLD/SCT SHRA ROUGHLY OVER THE W HALF OF UPPER MI. SINCE SHORTWAVE IS WEAKER THAN LAST NIGHTS WAVE...MUCAPE IS UNDER 100J/KG... SHOWALTER INDEX IS ABOVE 0 AND NO TSRA HAVE DEVELOPED WITH WAVE SO FAR THIS AFTN...HAVE REMOVED ANY MENTION OF THUNDER TONIGHT. ISOLD -SHRA MAY LINGER THRU WED MORNING WITH WEAK TRAILING SHORTWAVE ENERGY. HOWEVER...WITH SOLID HEIGHT RISES TAKING OVER DURING THE DAY (12HR 500MB HEIGHTS RISE 70-90M) ALONG WITH COLUMN DRYING...EXPECT A DRYING TREND WED. THERE MAY BE A FEW AFTN -SHRA OVER THE SCNTRL AS LAKE MICHIGAN LAKE BREEZE TRIES TO MOVE INLAND...SO ISOLD -SHRA MENTION WAS LINGERED INTO THE AFTN IN THAT AREA. AS OPPOSED TO TODAY...EXPECT MORE SUNSHINE TO DEVELOP WED UNDER DRYING/HEIGHT RISES. THIS WILL HELP BOOST TEMPS TOWARD 70F INLAND. WHERE WINDS ARE ONSHORE THRU THE DAY...TEMPS ALONG LAKE SUPERIOR WILL NOT GET OUT OF THE 50S. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 326 PM EDT TUE JUL 8 2014 LARGE SCALE PATTERN LOOKS SIMILAR TO WHAT WAS OCCURRING THIS TIME LAST WEEK. TROUGHING TO START THE WEEK THEN RELAXING HEIGHTS MORE ZONAL FLOW LATE WEEK INTO THE WEEKEND. SEEMS THIS PATTERN CHANGES BACK TO TROUGHING QUICKER THOUGH WITH ECMWF/GFS/GEM-NH TRENDING BACK TO TROUGHING BY SUNDAY AND PERSISTING INTO EARLY NEXT WEEK. PRIMARY RAIN CHANCES OCCUR AS THE FLOW GOES ZONAL...FRIDAY INTO SATURDAY. DECENT AGREEMENT THAT MAIN COLD FROPA OCCURS LATE FRIDAY NIGHT INTO SATURDAY. DPROG/DT...SEEING HOW THE MODELS ARE CHANGING OVER THEIR RECENT RUNS...INDICATES STRONG CONSISTENCY FM THE MODELS IN MASS FIELDS /MID-LEVEL HEIGHTS AND MSLP/ THROUGH SATURDAY. AHEAD OF THE COLD FROPA ON SATURDAY...HIGH PRESSURE AND MAINLY DRY WEATHER IS OVER THE REGION WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. LOW TEMPS COOLEST ON WED NIGHT WITH PWATS AROUND 50 PCT OF NORMAL BENEATH THE RIDGE AXIS. FAVORED COLD SPOTS INTERIOR MAY SEE LOWS AROUND 40 DEGREES. OTHERWISE...READINGS WILL BE IN THE 40S TO AROUND 50. WARMER NIGHT EXPECTED ON THURSDAY NIGHT AS SOUTHERLY RETURN FLOW DEVELOPS AS RIDGE AXIS SLIDES EAST. MAX TEMPS ON THURSDAY AROUND NORMAL IN THE MID TO UPPER 70S...WITH ONLY LOCAL COOLING NEAR IMMEDIATE GREAT LAKES SHORES. CLOUDS WILL INCREASE LATER THURSDAY NIGHT AS SHORTWAVES BEGIN TO WORK ACROSS NORTHERN PLAINS AND UPPER GREAT LAKES IN A MORE WESTERLY FLOW ALOFT. LEAD SHORTWAVE CURRENTLY OFFSHORE OF OREGON SLIDES ACROSS ON FRIDAY. STRONGER WAVE IS FORECAST TO CROSS MANTIOBA AND NORTHWEST ONTARIO. H85-H7 MOISTURE TRANSPORT LOOKS SPLIT IN TWO AREAS...STRONGEST CLOSER TO THE CANADIAN TROUGH. INSTABILITY AXIS BOTH AT SFC AND ALOFT ELEVATED LAGS BOTH WAVES SO NOT EXPECTING STRONG STORMS LATER THU NIGHT OR FRIDAY. THETA-E ADVECTION RAMPS UP FRIDAY NIGHT INTO SATURDAY MORNING AHEAD OF COLD FRONT WHICH WILL SUPPORT GREATER COVERAGE OF SHRA/TSRA. INSTABILITY REMAINS ONLY MARGINAL WITH 200-400J/KG OF 1-6KM MUCAPE AS GREATEST MLCAPE AND 1-6KM MUCAPE SETTLES MORE SOUTH INTO MIDDLE MISSISSIPPI VALLEY THAN EAST ACROSS THE GREAT LAKES. DEEP LAYER SHEAR VALUES ARE UP TO 30 KTS FRIDAY NIGHT...SO CANNOT COUNT OUT SOME STRONGER STORMS. SEVERE RISK DOES APPEAR PRETTY MARGINAL. DEEP LAYER SHEAR INCREASES TO 40+ KTS BY SATURDAY AFTN. 12Z ECMWF INDICATES MORE MLCAPE THAN EARLIER RUNS...CENTERED OVER CNTRL UPR MICHIGAN IN THE AFTN. LOOKS AS IF THE COLD FRONT MAY BE SLIGHTLY SLOWER. AS LONG AS THE SHRA/TSRA FROM FRIDAY NIGHT AND ASSOCIATED COOLING/STABILIZING AFFECTS ARE OUT OF THE WAY IN TIME...COULD SEE ISOLD STRONG OR SEVERE STORMS OVR CNTRL UPR MICHIGAN SATURDAY AFTN IF THERE IS ENOUGH SUNSHINE. H7 WINDS ARE MORE WESTERLY. ATTM BASED ON EXPECTED POSITION OF COLD FRONT AND A MORE WEST TO EAST MEAN STORM MOTION...LOOKS LIKE GREATEST RISK FOR STRONGER STORMS WOULD BE OVER SCNTRL UPR MICHIGAN. WHATEVER SHRA/TSRA ARE AROUND SATURDAY AFTERNOON...SHOULD DIMINISH/END LATER SATURDAY NIGHT. MODEL CONSISTENCY BECOMES MORE JUMPY SUNDAY/MONDAY...BUT LAST COUPLE RUNS OF EACH MODEL IS HEADING TOWARD MORE TROUGHING/COOLER WEATHER. PRIMARY ISSUE IS POSSIBLE DEVELOPMENT OF STRONGER SFC LOW PRESSURE ON LEADING EDGE OF MID-LEVEL TROUGH SATURDAY NIGHT INTO SUNDAY. RECENT RUNS OF GEM-NH STILL HANGING ON TO THIS IDEA WHILE 06Z GFS WAS THE FIRST GFS RUN SINCE JULY 7/12Z TO SHOW SIMILAR SOLN. 12Z GFS DOES NOT HAVE IT AGAIN. ECMWF SHOWED STRONGER LOW ON THE JULY 6/12Z RUN...BUT HAS SINCE BACKED AWAY. BY EARLY NEXT WEEK...TREND IS CERTAINLY THERE FOR A RETURN TO TROUGHING AND BLO NORMAL TEMPS...LIKELY OVER 20 DEGREES BLO NORMAL FOR DAYTIME HIGHS NEAR LK SUPERIOR. CORE OF COOLEST AIR AT H85 OVER MANITOBA AND ONTARIO BOTTOMS OUT AROUND 0C ON THE ECMWF AND AROUND +2C ON THE GFS ON MONDAY. UPPER LOW CENTER SETTLES ACROSS GREAT LAKES BY NEXT TUESDAY WITH H85 TEMPS STAYING BLO +5C AND PLENTY OF H85-H7 MOISTURE. SFC LOW FORECAST TO BE EAST OF LK SUPERIOR REGION... SO NORTH WINDS WILL KEEP UPPER GREAT LAKES VERY COOL. RECORD LOW MAXES FOR MID JULY ARE IN THE UPPER 50S TO LOWER 60S...BUT SOME VALUES IN JULY ARE EVEN IN THE LOWER 50S. MAY SEE SOME TEMPS EARLY NEXT WEEK COME CLOSE TO THESE LOWER READINGS. IT IS CERTAINLY WITHIN THE REALM OF POSSIBILITY. CHANCES OF SEEING CLOUDS AND SHOWERS IN THE PATTERN PRETTY HIGH...SO THAT WOULD ONLY HELP KEEP TEMPS ON THE COOL SIDE. PROBABLY GOES WITHOUT SAYING...BUT NO REAL STRETCHES OF WELL ABOVE NORMAL TEMPS ARE SEEN ANYTIME IN THE MEDIUM RANGE TIME PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 141 PM EDT TUE JUL 8 2014 DESPITE HIGH SUN ANGLE AT THIS TIME OF YEAR...LOW CLOUDS (IFR/LIFR CONDITIONS) HAVE PERSISTED INTO THE EARLY AFTN AT KIWD/KCMX/KSAW. STILL EXPECT IMPROVEMENT AS DAYTIME HEATING CONTINUES TO WORK AT RAISING CIGS FROM THE CLOUD DECK EDGES. ALL TERMINALS SHOULD BE VFR BY LATE AFTN. BEING FARTHEST FROM CLOUD BREAKS PER VIS SATELLITE IMAGERY AND DUE TO CHILLY UPSLOPE FLOW OFF LAKE SUPERIOR...KSAW WILL SEE SLOWEST IMPROVEMENT THIS AFTN. NOT OUT OF THE QUESTION THAT KSAW WILL IMPROVE SLOWER THAN REFLECTED IN THIS FCST. VFR CONDITIONS SHOULD PREVAIL AT ALL TERMINALS TONIGHT INTO WED. DISTURBANCE DROPPING INTO THE UPPER LAKES MAY BRING SOME -SHRA TO KIWD/KCMX LATE THIS EVENING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 326 PM EDT TUE JUL 8 2014 WINDS ARE EXPECTED TO STAY BELOW 25 KTS THROUGH THE PERIOD OUTSIDE OF ANY STRONGER THUNDERSTORMS. GREATEST CHANCES FOR THUNDERSTORMS WILL BE FRIDAY NIGHT INTO SATURDAY AS A COLD FRONT GRADUALLY CROSSES LAKE SUPERIOR. COULD SEE DENSE FOG AT TIMES FOR THE UPCOMING WEEKEND OVER NORTHERN SECTIONS AS SOUTH WINDS TRANSPORT MORE HUMID AIR ACROSS LK SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
308 PM CDT TUE JUL 8 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 302 PM CDT TUE JUL 8 2014 LOOKS A QUIET SHORT TERM WITH COOL NORTHWEST FLOW AND BELOW NORMAL TEMPERATURES TONIGHT AND TOMORROW. SCATTERED SHOWERS AND WEAK THUNDERSTORMS OVER WI ARE LOCATED IN AN AREA OF STRONGER COLD ADVECTION AND OUT AHEAD OF A SUBTLE SHORTWAVE FEATURE DROPPING SOUTH ACROSS MN AND WI. THERE IS A SECOND PV ANOMALY IN SD WITH TALLER CUMULUS CLOUDS IN EASTERN SD AND WESTERN MN...BUT THE SHOWER ACTIVITY HAS REMAINED MUCH MORE SPARSE UP TO THIS POINT. VISIBLE SATELLITE ALSO SHOWS A HEALTHY AMOUNT OF SMOKE DROPPING SOUTH ACROSS THE DAKOTAS THIS AFTERNOON...WHICH MIGHT MAKE FOR A COLORFUL SUNSET THIS EVENING...ESPECIALLY FOR THOSE IN WESTERN MN WHO ARE CLOSER TO THE EDGE OF THE SMOKE. THE SMOKE IS BEING ADVECTED SOUTH FROM WILDFIRES IN CANADA...MOST LIKELY FROM WHAT IS BURNING IN THE NORTHWEST TERRITORIES. SATELLITE SHOWED A THICK LAYER OF SMOKE IN ALBERTA AND SASKATCHEWAN AT THIS TIME YESTERDAY. THE ATMOSPHERIC COLUMN CONTINUES TO DRY FROM WHAT WAS PRESENT ON SUNDAY/MONDAY...THE LAST COUPLE MPX SOUNDINGS HAVE SHOWN PWATS OF 1.25" AND 0.90" RESPECTIVELY AND THE EARLY AFTERNOON RAP ANALYSES ARE HOVERING RIGHT AROUND 0.75". THERE IS AN OBVIOUS REDUCTION IN SURFACE MOISTURE TODAY...WITH DEWPOINTS COMFORTABLY IN THE 50S. NOT MUCH ELSE GOING ON IN THE SHORT TERM WITH A SURFACE HIGH SETTLING IN FOR TOMORROW. WITH THE HIGH OVERHEAD...MN/WI WILL BE OUT OF THE BEST PRESSURE GRADIENT AND WILL SEE LIGHTER WINDS TOMORROW. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 302 PM CDT TUE JUL 8 2014 THE MAIN THEME THROUGH THE LATTER PORTION OF THE FORECAST WILL BE A RE-AMPLIFICATION OF THE UPPER AIR PATTERN INTO THAT ALL TOO FAMILIAR CONFIGURATION WE/VE SEEN FOR MUCH OF THE PAST 9 MONTHS. FOR US THAT MEANS AFTER SOME BRIEF MODIFICATION OF TEMPERATURES DURING THE SECOND HALF OF THIS WEEK WE/LL SEE THINGS COOL OFF SUBSTANTIALLY AS WE MOVE TOWARD THE START OF NEXT WEEK. IN THE DETAILS... PCPN CHANCES LOOK TO RETURN FROM WEST TO EAST THURSDAY AND THURSDAY NIGHT AS THE SURFACE HIGH SHIFTS EAST AND WARM ADVECTION COMMENCES OVER THE AREA. IT THEN APPEARS WE/LL NEED TO INCLUDE CHANCE POPS FOR MUCH OF THE TIME FRAME THROUGH AT LEAST SATURDAY AS THE BAROCLINIC ZONE LINGERS IN THE AREA AND WE SEE PERIODIC WEAK DISTURBANCES MOVE THROUGH THE FLOW AND ACROSS OUR AREA. MUCH COOLER TEMPERATURES LOOK TO RETURN BY SUNDAY OR MONDAY AS THE EASTERN TROUGH SIGNIFICANTLY AMPLIFIES. THIS SHOULD BRING DRIER AIR INTO THE REGION AS THE UPPER JET IS DISPLACED SOUTHWARD... ALTHOUGH SUNSHINE DURING THIS TIME OF YEAR COULD CERTAINLY LEAD TO SOME DIURNAL PCPN IF WE HAVE SUFFICIENT CYCLONIC FLOW AND EKMAN PUMPING IN THE BOUNDARY LAYER. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1259 PM CDT TUE JUL 8 2014 NO MAJOR AVIATION WEATHER CONCERNS OVER THE NEXT 24-26 HOURS. SCATTERED TO BROKEN CUMULUS CLOUDS WILL DISSIPATE AROUND SUNSET...AS WILL THE WINDS. NO PRECIP IS EXPECTED AND WE HAVE HIGH CONFIDENCE IN VFR AND LITTLE VARIATION IN WIND DIRECTION. SHOWERS WILL GRAZE THE KEAU AIRPORT THIS AIRPORT THIS AFTERNOON...BUT SHOULD ONLY LAST A COUPLE HOURS. KMSP... NO MAJOR AVIATION WEATHER CONCERNS...BUT WE SHOULD KEEP THE BROKEN CUMULUS CLOUDS UNTIL WE BEGIN TO LOSE OUT HEATING LATE THIS AFTERNOON. THEY WILL QUICKLY CLEAR IN THE EARLY EVENING. /OUTLOOK FOR KMSP/ WED...VFR. W-NW WIND LESS THAN 5 KT. THU...VFR. MVFR POSSIBLE IN SHRA/TS LATE. SSE WIND 10 TO 15 KT. FRI...MVFR CONDITIONS POSSIBLE WITH A CHANCE OF SHRA/TSRA. SOUTH WIND 5 TO 10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...CLF LONG TERM... AVIATION...CLF
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1223 PM CDT TUE JUL 8 2014 .UPDATE... ISSUED AT 1223 PM CDT TUE JUL 8 2014 UPDATED FOR THE 18Z AVIATION DISCUSSION. UPDATE ISSUED AT 914 AM CDT TUE JUL 8 2014 UPDATED TO INCREASE POPS TODAY WITH THE SCATTERED RAIN SHOWERS AND POSSIBLY A FEW ISOLATED WEAK STORMS ACROSS THE REGION IN THE AFTERNOON. NO OTHER SIGNIFICANT CHANGES MADE TO THE SHORT TERM FORECAST AT THIS TIME. && .SYNOPSIS... ISSUED AT 301 AM CDT TUE JUL 8 2014 MID LVL LOW OVER HUDSON BAY EARLY THIS MORNING WITH A FAIRLY LARGE AREA OF CYCLONIC CIRCULATION ASSOCIATED WITH ITS PRESENCE. WITHIN THE CIRCULATION MULTIPLE SHORTWAVE TROFS CONTINUE TO MOVE WITHIN THE FLOW. LATEST WV IMAGERY SHOWS AT LEAST 3 SHORTWAVES EVIDENT ACROSS WRN ONTARIO AND MANITOBA. SCTD SHOWERS CONTINUE TO DEVELOP/OCCUR OVER ERN THIRD OF CWA DESPITE LOSS OF EARLIER INSTABILITY. A WELL DEFINED SHEAR AXIS/WIND SHIFT IS INDICATED IN THE 925 FLOW FROM ERN LAKE COUNTY IN THE ARROWHEAD CURVING THROUGH THE APOSTLES. THIS IS RELATED TO A BACKDOOR FRONTAL BDRY REPRESENTED IN THE LOW LVL THERMAL FIELDS. HEAVY PRECIP...RADAR ESTIMATES AND GROUND REPORT OVER 2 INCHES IN IRON COUNTY...HAS MOVED OUT OF THE CWA. CALLS TO LOCAL LAW OFFICIALS IN THE AREA AND CHECK ON A FEW RIVERS INDICATES THREAT APPEARS TO BE OVER. HAVE LET FLS EXPIRE AT 3AM. && .SHORT TERM...(TODAY THROUGH TOMORROW) ISSUED AT 301 AM CDT TUE JUL 8 2014 TODAY...BACK DOOR FRONTAL BDRY WILL MOVE INTO THE TWIN PORTS EARLY IN THE MORNING AND WEAKEN BY MIDDAY. DISTURBING DIFFERENCES BETWEEN MDLS WITH REGARD TO TIME/HEIGHT XSEC OF MOISTURE WITH EC SUGGESTING WHATEVER LOW CLOUD IS EVIDENT IN MORNING WILL LIFT WITH DAYTIME WARMING. NAM12/RAP SUGGEST A LOW OVERCAST MAY DWELL INTO AFTERNOON AROUND LAKE SUPERIOR. WILL GO PESSIMISTIC IN MORNING AND IMPROVING TREND IN AFTN. PESKY UPPER AIR PATTERN MAKES PLACEMENT OF HIGHEST POPS A BIT CHALLENGING TODAY SO ADDITIONAL UPDATES MAY BE NECESSARY. WITH A LACK OF A LOW LVL FOCUS FOR BDRY LYR CONVERGENCE THE POPS ARE BASED ON A GUESSTIMATE OF THE AXIS OF GREATEST INSTABILITY. USING RUC13 THIS APPEARS TO LINE UP FROM THE IRON RANGE TO NW WISC DURING THE MAJORITY OF THE DIURNAL WARMING. HI RES SIM REFL PRODUCTS SHOW NATURE OF SYNOPTIC PATTERN WITH LARGE INCREASE IN INSTABILITY ECHOES LATE MORNING THROUGH EARLY EVENING OVER MOST OF CWA. SIGNIFICANT DECREASE IN 925 TEMPS COMPARED TO YESTERDAY SO MAX TEMPS WILL BE ABOUT 5 TO 10 DEGREES COOLER IN MANY AREAS. TONIGHT/TOMORROW...MID LVL TROF OVER ONTARIO AND THE GT LAKES WILL SLOWLY SHIFT EAST. LOW LVL CYCLONIC CIRCULATION WILL BE REPLACED BY ANTICYCLONIC FLOW AS A WEAK SFC HIGH MOVES ACROSS UPPER MIDWEST WEDNESDAY. HAVE INSERTED VERY LOW POPS OVER SERN PART OF CWA IN THE AFTN WITH AXIS OF FCST INSTABILITY....ALBEIT MEAGER...IN THE VICINITY. OTHERWISE A PLEASANT DAY WITH NEAR TYPICAL TEMPS. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 301 AM CDT TUE JUL 8 2014 THE AREA OF HIGH PRESSURE WILL CONTINUE TO DOMINATE THE FORECAST AREA THROUGH THURSDAY AFTERNOON. THE TEMPERATURES WILL BE AT OR A LITTLE BELOW THEIR NORMAL VALUES. A WEAK SHORTWAVE WILL MOVE THROUGH CENTRAL MINNESOTA THURSDAY AFTERNOON AND MAY BRING A SHOWER OR THUNDERSTORMS TO SOUTHERN CASS AND CROW WING COUNTIES BUT THESE POPS WILL BE LOW. A COLD FRONT WILL APPROACH THE REGION THURSDAY NIGHT AND MOVE THROUGH THE FORECAST AREA ON FRIDAY AND FRIDAY NIGHT. WITH THE INCREASED MOISTURE AHEAD OF THE FRONT...THERE WILL BE A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. THE GFS IS FASTER THAN THE ECMWF WITH HIS FEATURE. BOTH MODELS NOW AGREE THAT SATURDAY WILL BE DRY WITH THE BULK OF THE PRECIP SOUTH OF THE FORECAST AREA. THE GFS HAS A FRONT MOVING THROUGH THE REGION ON SUNDAY WITH THE ECMWF A LITTLE SLOWER WITH THE FEATURE. WILL GO WITH A COMPROMISE AT THE MOMENT BUT WILL REFINE AS THE WEEKEND GETS CLOSER. HIGH PRESSURE BUILDS IN FOR THE BEGINNING OF THE WORK WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1223 PM CDT TUE JUL 8 2014 MUCH OF NE MINNESOTA AND NW WISCONSIN HAD VFR CONDITIONS WITH CIGS IN THE 3500 TO 5000 FT RANGE...5 TO 15 KNOT WINDS FROM THE WNW TO NW...AND THERE WERE SHOWERS OVER PARTS OF THE REGION. PARTS OF FAR NORTHERN MINNESOTA HAD LINGERING MVFR CIGS. THERE SHOULD BE A GRADUAL TREND TOWARDS VFR THIS AFTERNOON. THE RAIN SHOWERS WILL CONTINUE...WHICH COULD BRING BRIEF MVFR VSBYS FROM THE RAIN. THE WINDS WILL BEGIN TO DISSIPATE THIS EVENING AND THERE WILL GRADUAL CLEARING OVERNIGHT. && .PRELIMINARY POINT TEMPS/POPS... DLH 70 51 72 52 / 50 20 0 0 INL 69 50 72 50 / 60 20 0 0 BRD 76 53 76 55 / 20 10 0 0 HYR 73 49 74 49 / 60 30 10 0 ASX 63 49 70 49 / 20 20 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ UPDATE...BJT SYNOPSIS...CANNON SHORT TERM...CANNON LONG TERM...STEWART AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1231 PM CDT Tue Jul 8 2014 .UPDATE: Issued at 734 AM CDT Tue Jul 8 2014 Showers and isolated thunderstorms associated with decaying MCS have rapidly diminished early this morning, and based on latest regional radar trends primary threat will be confined to far southern sections of the FA over the next few hours. No changes to the afternoon trends at this time, with primary threat of redevelopment south of a Steelville-KCPS-Vandalia IL line. Zone update out shortly. Truett && .SHORT TERM: (Through Late This Afternoon) Issued at 353 AM CDT Tue Jul 8 2014 The weakening MCS moving southeastward through east central and southeast MO as well as southwest IL should shift southeast of our forecast area later this morning. The cold front now across northwest MO will move southeastward through the forecast area today. Although we could not rule out redevelopment of convection this afternoon along and just ahead of this cold front, it appears that the effective low level boundary will be the outflow from this mornings MCS which will be southeast of our forecast area this afternoon. The latest HRRR develops convection late this afternoon south and southeast of the forecast area. Even the operational models afternoon qpf is confined to the extreme southern or southeastern portion of our forecast area. For now will include chance pops across southeast MO and southwest IL, south and east of STL for this afternoon. High temperatures today will be slightly cooler than yesterday due to at least weak cold air advection behind the cold front and gradually lowering 850 mb temperatures. GKS .LONG TERM: (Tonight through Monday) Issued at 445 AM CDT Tue Jul 8 2014 It appears that the showers/storms will be south or southeast of our forecast area by this evening as a surface ridge builds southeastward into our area behind the cold front. This will bring cooler and less humid air into the region tonight and Wednesday. Will have at least slightly below normal temperatures for tonight through Wednesday night. The next chance of convection will occur over the northern portion of our forecast area late Thursday night and Friday morning due to strong low level warm air advection and moisture convergence on the nose of a southwesterly low level jet ahead of a northwest flow shortwave. The models were also depicting relatively strong upper level divergence ahead of this shortwave. A warming trend will also begin Thursday night and Friday along with increasing humidities due to southerly return flow on the backside of the surface ridge as it shifts east of the region. An upper level ridge will try to build northeastward into southwestern MO Friday night and Saturday. Any potential for convection should be confined to the northern and eastern portion of the forecast area as shortwaves move east southeastward over the upper level ridge. Temperatures should be quite warm this weekend, especially across central and southeast MO. There will be the chance of showers/storms across the entire area as we head into the next work week as the models deepen an upper level trough over the Great Lakes region and send a cold front southeastward through our forecast area Sunday night and Monday. The ECMWF model is stronger or deeper with this upper level trough compared to the GFS model and is also slower moving the front through our forecast area and has more qpf associated with this front. Due to the model inconsistencies will just include chance pops for most of the area on Monday along with cooler high temperatures. GKS && .AVIATION: (For the 18z TAFs through 18z Wednesday Afternoon) Issued at 1220 PM CDT Tue Jul 8 2014 Current cigs will break up and become sct this afternoon. Expect the remainder of the TAF period to be VFR. Winds will diminish and back slightly this evening and become nwly again Wed morning. Only expect diurnal CU Wed morning. Some guidance is suggesting that FG may develop and impact UIN/COU late tonight. While the rainfall last night may support this, believe enuf mixing will persist tonight to prevent FG development. Specifics for KSTL: VFR and dry conditions are expected thru the period. Cigs are expected to quickly break up this afternoon with winds remaining nwly this afternoon. Winds will diminish and back slightly this evening and become nwly again Wed morning. Only sct diurnal CU is expected Wed. Tilly && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ELKO NV
252 PM PDT TUE JUL 8 2014 .SYNOPSIS... MOIST AIR MASS WILL KEEP THREAT OF THUNDERSTORMS OVER CENTRAL AND EASTERN NEVADA THROUGH THURSDAY. SOME STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL. DRIER AIR WILL THEN MOVE THROUGH THE REGION FRIDAY AND PUSH THE THUNDERSTORM CHANCES TO AREAS NORTH OF INTERSTATE 80. DRY CONDITIONS ARE EXPECTED SATURDAY THROUGH NEXT TUESDAY. && .SHORT TERM... SHOWERS AND THUNDERSTORMS HAVE DEVELOPED MAINLY SOUTH OF INTERSTATE 80 TO FROM NORTHERN NYE COUNTY SO FAR TODAY. LATEST GUIDANCE INCLUDING HRRR MODEL KEEPS THE CONVECTIVE ACTIVITY GOING ACROSS MOST AREAS THROUGH THIS EVENING, EXCEPT FOR LESS COVERAGE ACROSS ELKO AND FAR NORTHERN HUMBOLDT COUNTIES. DEW POINTS RANGE FROM THE 20S AND 30S FROM I-80 NORTHWARD, TO THE LOWER 50S ACROSS NORTHERN NYE COUNTY. AS CELLS MOVE NORTH INTO THE DRIER AIR MASS, SOME OUTFLOW GUSTS COULD EXCEED 40 MPH THIS EVENING. OTHERWISE, THE MAIN IMPACT WILL BE LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING. ISOLATED CELLS WILL CONTINUE OVERNIGHT DUE TO RESIDUAL MOISTURE AND WEAK SHORTWAVE ENERGY ROTATING INTO CENTRAL NV, WITH ANOTHER ROUND OF SCATTERED TO WIDESPREAD THUNDERSTORM FORMATION REGIONWIDE. HIGHER DEW POINTS IN THE 40S TO LOWER 50S WILL SPREAD NORTH TO THE OREGON AND IDAHO BORDERS. THE ONLY LIMITING FACTOR WOULD BE EXCESSIVE CLOUD COVER LIMITING DAYTIME HEATING, BUT THERE SHOULD BE ENOUGH BREAKS IN CLOUD COVER AND SUFFICIENT FORCING TO PRODUCE THUNDERSTORMS, WITH SLOW CELL MOTIONS AND HIGH PRECIPITABLE WATER VALUES LEADING TO HEAVY RAINFALL AND POSSIBLE LOCAL FLOODING. BY THURSDAY, ANOTHER SHORTWAVE WILL BRING ONE MORE ROUND OF THUNDERSTORMS MAINLY NORTH OF HIGHWAY 50, WITH LOCALLY HEAVY RAINFALL AGAIN POSSIBLE. BY THIS TIME, AREAS THAT BECOME SATURATED FROM RAINFALL TODAY OR WEDNESDAY MAY NEED TO BE WATCHED FOR POSSIBLE FLASH FLOOD WATCH. SOUTH OF HIGHWAY 50, DRIER AIR WILL BEGIN TO SPREAD NORTH, REDUCING THE COVERAGE OF THUNDERSTORMS. IN AREAS NOT COVERED ALL DAY BY CLOUD COVER, DAYTIME HIGHS SHOULD REACH THE 90S IN MOST LOWER ELEVATIONS BELOW 5500 FEET, AND MID TO UPPER 80S ABOVE 5500 FEET. MIN TEMPS WILL BE MUCH HIGHER THAN AVERAGE DUE TO THE MOIST AIR MASS AND CLOUD COVER, WITH LOWS MAINLY IN THE 60S. MJD .LONG TERM...FRIDAY THROUGH TUESDAY... FOR FRIDAY, THE MOISTURE WILL CONTINUE DECREASING FROM SOUTH TO NORTH, RESULTING IN THUNDERSTORMS GENERALLY LIMITED TO NORTH OF INTERSTATE 80 WITH DECREASED COVERAGE COMPARED TO THURSDAY. OTHERWISE FROM SATURDAY THROUGH TUESDAY, HIGH PRESSURE RIDGE REBUILDING OVER THE FOUR CORNERS REGION WILL BRING DRIER AND MORE STABLE AIR MASS TO THE REGION, ENDING THE THREAT OF THUNDERSTORMS. TEMPERATURES WILL REMAIN ABOVE NORMAL WITH HIGHS APPROACHING 100 DEGREES IN SOME OF THE WARMER VALLEYS. MJD && .AVIATION... THUNDERSTORMS WILL PRODUCE THE MAIN AVIATION IMPACTS THROUGH THURSDAY. COVERAGE WILL BE GREATEST DURING THE AFTERNOON AND EVENING, BUT SOME CELLS WILL LINGER THROUGH THE OVERNIGHT AND MORNING HOURS. HEAVY RAIN WILL BE THE MAIN THREAT, ALTHOUGH THIS EVENING SOME OUTFLOW GUSTS COULD EXCEED 35 KT ESPECIALLY NEAR AND NORTH OF I-80 AS INITIAL CELLS ENCOUNTER DRIER AIR MASS. MJD && .FIRE WEATHER... WHILE NUMEROUS LIGHTNING STRIKES (LAL AS HIGH AS 4 IN SOME AREAS) ARE EXPECTED THROUGH THURSDAY, THE SLOW CELL MOVEMENT AND HIGH PRECIPITABLE WATER VALUES WILL RESULT IN MOST STORMS PRODUCING WETTING RAINS. THIS SHOULD LIMIT SPREAD OF ANY LIGHTNING-INDUCED FIRE STARTS, IF ANY OCCUR. MJD && .LKN WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
230 PM EDT TUE JUL 8 2014 .SYNOPSIS...BROAD HIGH PRESSURE WEAKENS AS A COLD FRONT MOVES TOWARD THE REGION FROM THE GREAT LAKES. THIS COLD FRONT SHOULD MOVE INTO THE MID-ATLANTIC WEDNESDAY...WEAKENING AS IT MOVES INTO NORTH CAROLINA THURSDAY. A TROUGH OF LOW PRESSURE THEN PERSISTS OVER THE REGION AT LEAST THROUGH FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 910 AM TUESDAY... THE LATEST SURFACE ANALYSIS SHOWED BROAD HIGH PRESSURE MOSTLY OVER THE MID-ATLANTIC AND THE CAROLINAS WITH A WEAK SURFACE TROUGH AMONG THE BROAD RIDGE OVER THE CENTRAL PIEDMONT. THE SPC MESOANALYSIS SHOWED A NOTICEABLE MINIMUM OF PRECIPITABLE WATER VALUES OVER THE WESTERN PART OF THE STATE...SIMILAR TO WHAT WAS FORECAST BY THE MONDAY GUIDANCE. THE RAP FORECASTS THIS MINIMUM TO MOVE ACROSS CENTRAL NORTH CAROLINA DURING THE DAY...AND FOR THE MOST PART RAP SOUNDINGS ARE SIMILAR TO SOUNDINGS FORECAST BY THE GFS MONDAY... QUITE STABLE TO DEEP CONVECTION DURING THE DAY. TWO CAVEATS TO THIS ARE CURRENTLY...AND VERY LATE TODAY. CURRENTLY...PRECIPITABLE WATER VALUES ARE AT OR ABOVE 1.5 INCHES OVER A LARGE PART OF CENTRAL NORTH CAROLINA...AND RAP SOUNDINGS SHOW THE PRESENCE OF MID-LEVEL INSTABILITY THAT WANES BY 18Z AS THE LOWER MOISTURE VALUES MOVE EAST. THE LATEST VISIBLE IMAGERY SHOWED A NARROW BAND OF MID-LEVEL CLOUDS THAT DEVELOPED FROM NEAR ROXBORO TO WADESBORO...AND THE HRRR WRF ACTUALLY FORECASTS A SHOWER OR TWO DEVELOPING FROM THIS. WATER VAPOR IMAGERY WOULD SUGGEST ENOUGH SUBSIDENCE TO PRECLUDE A SHOWER... BUT THE DEVELOPMENT OF THE CLOUDS PLUS THE PRESENCE OF WEAK INSTABILITY MAKES IT WORTHY OF NOTE HERE. LATE TODAY...THE RAP FORECASTS LIFT MOVING INTO THE FAR NORTHWEST PIEDMONT TOWARD KINT BY 23Z. RAP SOUNDINGS ARE STILL FAIRLY STABLE AT THAT POINT...AND QPF ON THE RAP IS NIL THROUGH 00Z WEDNESDAY. PRECIPITABLE WATER VALUES INCREASE QUICKLY ON THE RAP...TO NEAR 1.5 INCHES JUST AFTER 00Z WEDNESDAY...AS K INDICES RISE TO NEAR 40. LIKE THE GFS FORECAST MONDAY...MODEST MID-LEVEL COOLING COUPLED WITH MOISTURE ADVECTION MAY BE ENOUGH FOR A SHOWER OR THUNDERSTORM TO MOVE INTO THE WEST AND NORTHWEST PIEDMONT THIS EVENING. MOS GUIDANCE POPS ARE A FEW PERCENTAGE POINTS LOWER THAN THAT GUIDANCE OF MONDAY...AND WRF ARW GUIDANCE SUGGESTS LITTLE PRECIPITATION INTO THE EVENING. STILL...THE MOISTURE ADVECTION AND SLIGHT COOLING ALOFT... COUPLED WITH A WEAKENING MID-LEVEL SHORTWAVE MOVING INTO THE WESTERN PIEDMONT THIS EVENING...IS ENOUGH TO AT LEAST CONTINUE THE SMALL CHANCES WEST AS CURRENTLY FORECAST THIS EVENING...AND MAY NEED TO EXPAND SLIGHTLY FARTHER EAST. THE 00Z GFS APPEARED TO SUFFER FROM SOME MINOR CONVECTIVE FEEDBACK WHILE THE ECMWF HAS BEEN VERY CONSISTENT IN SUGGESTING THE BEST THREAT FOR OVERNIGHT CONVECTION TO OUR NW. IT SHOULD ALSO BE NOTED THAT THE CONVECTIVE ALLOWING MODELS VERIFIED WAY OVERDONE ACROSS THE OH VALLEY INTO THE MID ATLANTIC AT 06Z. HIGHS TODAY IN THE LOWER TO MID 90S. WARM OVERNIGHT WITH LOWS NEAR 70 TO THE LOWER 70S. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... AS OF 310 AM TUESDAY... MID LEVEL SHEAR AXIS ASSOCIATED WITH THE NORTHERN STREAM S/W AND ITS ATTENDANT SURFACE BOUNDARY WILL DRIFT SEWD INTO CENTRAL NC WEDNESDAY AFTERNOON-WEDNESDAY NIGHT. THIS SYSTEM WILL INTERACT WITH STRONG HEATING AND AVAILABLE MOISTURE (PRECIPITABLE WATER VALUES IN THE NEIGHBORHOOD OF 1.67-1.9 INCHES) TO INITIATE AND SUSTAIN SCATTERED CONVECTION...ESPECIALLY WEDNESDAY AFTERNOON-WEDNESDAY EVENING. SOME CONVECTIVE PARAMETERS SUGGEST SOME POTENTIAL FOR ORGANIZED CONVECTION IN THE FORM OF BROKEN CONVECTIVE SEGMENTS. IF THESE SEGMENTS WERE TO DEVELOP...COULD SEE A DAMAGING WIND THREAT WITH THE STRONGER CELLS. THIS THREAT APPEARS GREATEST ACROSS THE NORTHERN PIEDMONT INTO THE NORTHERN COASTAL PLAIN (GENERALLY NORTH OF I-40) WHERE BULK SHEAR VALUES APPROACH 30 KTS. DUE TO PRESENCE OF SHEAR AXIS AND SFC BOUNDARY...EXPECT SCATTERED CONVECTION TO PERSIST WELL INTO THE NIGHT THOUGH OVERALL COVERAGE AND INTENSITY WILL DIMINISH AS NEAR SURFACE AIR MASS UNDERGOES NOCTURNAL STABILIZATION. HIGH TEMPS WEDNESDAY DEPENDENT UPON AMOUNT OF INSOLATION AND CONVECTIVE COVERAGE. IF SUN LIMITED DUE TO EXTENSIVE CLOUD COVERAGE OR IF THE GFS IS CORRECT AND SCATTERED CONVECTION IS OCCURRING AT THE THE START OF THE DAY...THEN MAX TEMPS ACROSS THE NORTH COULD END UP BEING 5-6 DEGREES COOLER THAN FORECAST. DUE TO ANTICIPATED TIMING...BELIEVE THAT THE SOUTHERN HALF OF THE FORECAST AREA STANDS A GOOD SHOT OF SEEING TEMPS RETURNING TO THE MID 90S. MIN TEMPS WEDNESDAY NIGHT IN THE UPPER 60S TO AROUND 70 NORTH AND LOWER 70S SOUTH. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 230 PM TUESDAY... FOR THU THROUGH FRI NIGHT: THU STILL APPEARS TO BE THE BUSIEST WEATHER DAY IN TERMS OF STORM COVERAGE. A SURFACE TROUGH WILL HOLD OVER CENTRAL NC THU... WITH ELEVATED LOW LEVEL MOISTURE TRANSPORT MAINLY EAST/SOUTH OF THE TRIAD. ALOFT... BROAD TROUGHING SETTING UP JUST TO OUR WEST WILL DRAW IN NRN STREAM ENERGY AS WELL AS PULL IN PERTURBATIONS FROM AN UPPER LEVEL WEAKNESS OVER THE WRN GULF OF MEXICO. WHILE THE TROUGH ITSELF WILL BE SOMEWHAT WEAK AT THIS LATITUDE WITH MINIMAL HEIGHT FALLS (10 M AT MOST ON THU) AND MLLR VALUES UNDER 6.5 C/KM... THE ADDED DYNAMIC FORCING FOR ASCENT SHOULD SUPPORT AT LEAST SCATTERED CONVECTION (MAXIMIZING IN -- BUT NOT RESTRICTED TO -- THE AFTERNOON/EVENING) DESPITE MARGINAL VALUES OF INSTABILITY DUE TO LAYERS OF A MOIST ADIABATIC PROFILE (NAM MLCAPE TOPPING OUT AT 500-1000 J/KG WITH GFS MUCAPE OF 1000-1500 J/KG IN THE EAST THU). FORECAST DEEP LAYER SHEAR VALUES ARE MORE FAVORABLE THAN YESTERDAY`S MODEL RUNS... NOW AROUND 25-35 KTS OVER NRN/WRN NC... INDICATING THE POTENTIAL FOR MORE ORGANIZED CONVECTION... ALTHOUGH THIS BETTER SHEAR WILL NOT QUITE BE SPATIALLY ALIGNED IN AN IDEAL MANNER WITH THE GREATER INSTABILITY. NEVERTHELESS... PW VALUES WILL REMAIN ABOVE NORMAL (1.7-2.0 IN.)... AND THIS MOISTURE COMBINED WITH LOW MBE TRANSLATIONAL SPEEDS AND A DECENT WARM CLOUD DEPTH NEAR 3.5 KM SUGGESTS THAT SOME SLOW-MOVING CELLS WITH EFFICIENT RAIN PROCESSES MAY GENERATE LOCALLY HEAVY RAINFALL. WILL BUMP UP POPS TO LIKELY... HIGHER EAST THAN WEST... ON THU EXTENDING INTO EARLY THU NIGHT... UNTIL THE MID LEVELS BEGIN TO DRY OUT A BIT. THE MID LEVEL TROUGH AXIS SHIFTS EAST OF THE SRN APPALACHIANS FRI... KEEPING ERN NC IN THE CROSSHAIRS OF SUFFICIENTLY DEEP MOISTURE AND MARGINAL SHEAR AND INSTABILITY... ENOUGH TO SUPPORT PRIMARILY AFTERNOON AND EVENING SHOWERS AND STORMS... WITH THE BEST CHANCES EAST OF I-95... ALONG/EAST OF WHERE THE SURFACE TROUGH SETTLES. EXPECT LOWER COVERAGE OVER THE REST OF CENTRAL NC WITH PW SLIPPING TO NEAR OR JUST BELOW NORMAL AND LOWER DEEP LAYER SHEAR (15-20 KTS)... ALTHOUGH GFS MUCAPE PEAKS ONCE AGAIN AT 1000-1500 J/KG OVER CENTRAL NC... SO CAN`T RULE OUT SCATTERED STORMS. WILL KEEP POPS RANGING FROM 25% NW TO 40-50% SE FRI. AN APPROACHING SHORTWAVE TROUGH... POTENT BUT SLOWLY WEAKENING... WILL DROP ESE THROUGH THE LOWER GREAT LAKES/OH VALLEY LATE FRI NIGHT... LIKELY LEADING TO CONTINUED PARTLY TO MOSTLY CLOUDY SKIES DOWNSTREAM OVER NC OVERNIGHT. THICKNESSES ARE PROJECTED TO BE NEAR NORMAL THU... WHICH WITH CONSIDERATION OF GOOD CONVECTIVE CLOUD COVERAGE WOULD SUPPORT HIGHS OF 86-92. THU NIGHT LOWS NOT FAR FROM NORMAL... 67-72. SLIGHTLY LESS WARMTH ON FRI WITH BELOW-NORMAL THICKNESSES POINTING TO HIGHS OF 86-90. FOR SAT-SUN: THE SURFACE TROUGH OVER ERN NC IS LIKELY TO DISSIPATE SAT AS IT IS OVERTAKEN BY THE ATLANTIC RIDGE BULGING WESTWARD... WITH FORMATION OF A NEW WEAK LEE TROUGH OVER THE PIEDMONT AND SOME ATTENDANT MINOR RECOVERY OF PW. THE AFOREMENTIONED WEAKENING MID LEVEL WAVE WILL CROSS THE MIDATLANTIC REGION SAT... ALTHOUGH MODEL DISPARITY EMERGES AS THE ECMWF IS SLOWER/STRONGER THAN THE GFS AND THEREFORE GENERATES MORE CONVECTION OVER CENTRAL/ERN NC. WILL RETAIN CHANCE POPS SAT... HIGHER EAST THAN WEST... GENERALLY FOLLOWING THE TYPICAL DIURNAL TREND. THE GFS DEPICTS FURTHER RECOVERY OF PW VALUES SUN WITH ANOTHER MINOR WAVE CROSSING THE REGION WITHIN VERY WEAK CYCLONIC FLOW AND A RETENTION OF THE PIEDMONT SURFACE TROUGH... AND WE SHOULD SEE YET ANOTHER ROUND OF MAINLY SCATTERED DIURNALLY-DRIVEN STORMS IN THE MID AFTERNOON INTO EARLY EVENING... WITH COVERAGE AND INTENSITY LIMITED BY THE WEAK DEEP LAYER SHEAR. FOR MON-TUE: THE GFE HAS COME INTO AGREEMENT WITH THE ECMWF`S SOLUTION (CONSISTENT OVER THE LAST FEW RUNS) REGARDING THE DEEPENING MID LEVEL VORTEX WHICH DRIFTS ACROSS THE GREAT LAKES/SE ONTARIO EARLY NEXT WEEK. THE PIEDMONT SURFACE TROUGH WILL SHARPEN AND PUSH A BIT TO THE SOUTHEAST IN RESPONSE TO THE APPROACHING SYNOPTIC COLD FRONT... EXPECTED TO PROGRESS SOUTHEAST TOWARD NW NC BY LATE TUE. PW REMAINS ABOVE NORMAL AREAWIDE MON... THEN THE HIGHER VALUES SHIFT TO OUR EAST TUE WITH THE SHIFTING TROUGH AND STRENGTHENING LOW AND MID LEVEL FLOW FROM THE WSW. WILL RETAIN CLIMATOLOGICALLY TYPICAL POPS MON (SLIGHTLY LOWER IN THE TRIAD AND HIGHER TO THE SOUTH/EAST... FOCUSED ON THE AFTERNOON INTO MID EVENING)... THEN TREND POPS BACK DOWN A TAD IN THE WEST TUE. THICKNESSES REBOUND BACK CLOSER TO NORMAL SO WILL NOT DEPART MUCH FROM SEASONAL NORMALS MON/TUE (WITH NORMAL HIGH/LOW OF 90/70 AT RDU AND 89/69 AT GSO). -GIH && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 155 PM TUESDAY... VFR CONDITIONS ARE EXPECTED THROUGHOUT MUCH OF THE 18Z VALID TAF PERIOD. AS MOISTURE INCREASES AGAIN OVER THE REGION FROM THE WEST...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS SHOULD OCCUR PARTICULARLY TOWARD THE TRIAD VERY LATE THIS AFTERNOON INTO THE EVENING. WITH UNCERTAINTY IN THE LOCATION OF ANY THUNDER ONLY INCLUDED A TEMPO FOR SHOWERS IN THE TAFS FOR KINT AND KGSO FROM ABOUT 23Z TO 04Z. ISOLATED SHOWERS OR SPRINKLES ARE POSSIBLE OVERNIGHT THEN CHANCES FOR SHOWERS INCREASE DURING WEDNESDAY WITH AT LEAST TEMPO CONDITIONS ANTICIPATED AROUND THE TRIAD DURING THE MORNING. SREF MODEL PROBABILITY OF IFR CONDITIONS ARE LOW BUT PROBABILITIES OF MVFR CONDITIONS ESPECIALLY OVER THE NORTHWEST PIEDMONT INCREASE AFTER 12Z WEDNESDAY AND HAVE INCLUDED SUCH CEILINGS IN THE TEMPO CONDITIONS AT KINT AND KGSO WEDNESDAY MORNING. GUSTY SOUTHWEST WINDS SHOULD DIMINISH BUT REMAIN NOTICEABLE OUT OF THE SOUTH TO SOUTHWEST OVERNIGHT...WITH A FEW GUSTS DEVELOPING MAINLY TOWARD KFAY WEDNESDAY MORNING WHERE HEATING TO START THE DAY SHOULD BE A LITTLE BETTER RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA. BEYOND THE 18Z VALID TAF PERIOD...AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS...AND THEIR ASSOCIATED SUB-VFR CONDITIONS...CAN BE EXPECTED OVER CENTRAL NORTH CAROLINA AT LEAST INTO THE END OF THE WORK WEEK. A COLD FRONT WEAKENS AS IT APPROACHES THE STATE THURSDAY...BUT A SURFACE TROUGH THEN LINGERS AT LEAST THROUGH FRIDAY AND LIKELY INTO AT LEAST PART OF THE WEEKEND. COVERAGE OF PRECIPITATION OVER CENTRAL NORTH CAROLINA SHOULD BE GREATER THURSDAY AND FRIDAY AS COMPARED TO THE UPCOMING WEEKEND. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...WSS/DJF SHORT TERM...WSS LONG TERM...HARTFIELD AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
156 PM EDT TUE JUL 8 2014 .SYNOPSIS...BROAD HIGH PRESSURE WEAKENS AS A COLD FRONT MOVES TOWARD THE REGION FROM THE GREAT LAKES. THIS COLD FRONT SHOULD MOVE INTO THE MID-ATLANTIC WEDNESDAY...WEAKENING AS IT MOVES INTO NORTH CAROLINA THURSDAY. A TROUGH OF LOW PRESSURE THEN PERSISTS OVER THE REGION AT LEAST THROUGH FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 910 AM TUESDAY... THE LATEST SURFACE ANALYSIS SHOWED BROAD HIGH PRESSURE MOSTLY OVER THE MID-ATLANTIC AND THE CAROLINAS WITH A WEAK SURFACE TROUGH AMONG THE BROAD RIDGE OVER THE CENTRAL PIEDMONT. THE SPC MESOANALYSIS SHOWED A NOTICEABLE MINIMUM OF PRECIPITABLE WATER VALUES OVER THE WESTERN PART OF THE STATE...SIMILAR TO WHAT WAS FORECAST BY THE MONDAY GUIDANCE. THE RAP FORECASTS THIS MINIMUM TO MOVE ACROSS CENTRAL NORTH CAROLINA DURING THE DAY...AND FOR THE MOST PART RAP SOUNDINGS ARE SIMILAR TO SOUNDINGS FORECAST BY THE GFS MONDAY... QUITE STABLE TO DEEP CONVECTION DURING THE DAY. TWO CAVEATS TO THIS ARE CURRENTLY...AND VERY LATE TODAY. CURRENTLY...PRECIPITABLE WATER VALUES ARE AT OR ABOVE 1.5 INCHES OVER A LARGE PART OF CENTRAL NORTH CAROLINA...AND RAP SOUNDINGS SHOW THE PRESENCE OF MID-LEVEL INSTABILITY THAT WANES BY 18Z AS THE LOWER MOISTURE VALUES MOVE EAST. THE LATEST VISIBLE IMAGERY SHOWED A NARROW BAND OF MID-LEVEL CLOUDS THAT DEVELOPED FROM NEAR ROXBORO TO WADESBORO...AND THE HRRR WRF ACTUALLY FORECASTS A SHOWER OR TWO DEVELOPING FROM THIS. WATER VAPOR IMAGERY WOULD SUGGEST ENOUGH SUBSIDENCE TO PRECLUDE A SHOWER... BUT THE DEVELOPMENT OF THE CLOUDS PLUS THE PRESENCE OF WEAK INSTABILITY MAKES IT WORTHY OF NOTE HERE. LATE TODAY...THE RAP FORECASTS LIFT MOVING INTO THE FAR NORTHWEST PIEDMONT TOWARD KINT BY 23Z. RAP SOUNDINGS ARE STILL FAIRLY STABLE AT THAT POINT...AND QPF ON THE RAP IS NIL THROUGH 00Z WEDNESDAY. PRECIPITABLE WATER VALUES INCREASE QUICKLY ON THE RAP...TO NEAR 1.5 INCHES JUST AFTER 00Z WEDNESDAY...AS K INDICES RISE TO NEAR 40. LIKE THE GFS FORECAST MONDAY...MODEST MID-LEVEL COOLING COUPLED WITH MOISTURE ADVECTION MAY BE ENOUGH FOR A SHOWER OR THUNDERSTORM TO MOVE INTO THE WEST AND NORTHWEST PIEDMONT THIS EVENING. MOS GUIDANCE POPS ARE A FEW PERCENTAGE POINTS LOWER THAN THAT GUIDANCE OF MONDAY...AND WRF ARW GUIDANCE SUGGESTS LITTLE PRECIPITATION INTO THE EVENING. STILL...THE MOISTURE ADVECTION AND SLIGHT COOLING ALOFT... COUPLED WITH A WEAKENING MID-LEVEL SHORTWAVE MOVING INTO THE WESTERN PIEDMONT THIS EVENING...IS ENOUGH TO AT LEAST CONTINUE THE SMALL CHANCES WEST AS CURRENTLY FORECAST THIS EVENING...AND MAY NEED TO EXPAND SLIGHTLY FARTHER EAST. THE 00Z GFS APPEARED TO SUFFER FROM SOME MINOR CONVECTIVE FEEDBACK WHILE THE ECMWF HAS BEEN VERY CONSISTENT IN SUGGESTING THE BEST THREAT FOR OVERNIGHT CONVECTION TO OUR NW. IT SHOULD ALSO BE NOTED THAT THE CONVECTIVE ALLOWING MODELS VERIFIED WAY OVERDONE ACROSS THE OH VALLEY INTO THE MID ATLANTIC AT 06Z. HIGHS TODAY IN THE LOWER TO MID 90S. WARM OVERNIGHT WITH LOWS NEAR 70 TO THE LOWER 70S. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... AS OF 310 AM TUESDAY... MID LEVEL SHEAR AXIS ASSOCIATED WITH THE NORTHERN STREAM S/W AND ITS ATTENDANT SURFACE BOUNDARY WILL DRIFT SEWD INTO CENTRAL NC WEDNESDAY AFTERNOON-WEDNESDAY NIGHT. THIS SYSTEM WILL INTERACT WITH STRONG HEATING AND AVAILABLE MOISTURE (PRECIPITABLE WATER VALUES IN THE NEIGHBORHOOD OF 1.67-1.9 INCHES) TO INITIATE AND SUSTAIN SCATTERED CONVECTION...ESPECIALLY WEDNESDAY AFTERNOON-WEDNESDAY EVENING. SOME CONVECTIVE PARAMETERS SUGGEST SOME POTENTIAL FOR ORGANIZED CONVECTION IN THE FORM OF BROKEN CONVECTIVE SEGMENTS. IF THESE SEGMENTS WERE TO DEVELOP...COULD SEE A DAMAGING WIND THREAT WITH THE STRONGER CELLS. THIS THREAT APPEARS GREATEST ACROSS THE NORTHERN PIEDMONT INTO THE NORTHERN COASTAL PLAIN (GENERALLY NORTH OF I-40) WHERE BULK SHEAR VALUES APPROACH 30 KTS. DUE TO PRESENCE OF SHEAR AXIS AND SFC BOUNDARY...EXPECT SCATTERED CONVECTION TO PERSIST WELL INTO THE NIGHT THOUGH OVERALL COVERAGE AND INTENSITY WILL DIMINISH AS NEAR SURFACE AIR MASS UNDERGOES NOCTURNAL STABILIZATION. HIGH TEMPS WEDNESDAY DEPENDENT UPON AMOUNT OF INSOLATION AND CONVECTIVE COVERAGE. IF SUN LIMITED DUE TO EXTENSIVE CLOUD COVERAGE OR IF THE GFS IS CORRECT AND SCATTERED CONVECTION IS OCCURRING AT THE THE START OF THE DAY...THEN MAX TEMPS ACROSS THE NORTH COULD END UP BEING 5-6 DEGREES COOLER THAN FORECAST. DUE TO ANTICIPATED TIMING...BELIEVE THAT THE SOUTHERN HALF OF THE FORECAST AREA STANDS A GOOD SHOT OF SEEING TEMPS RETURNING TO THE MID 90S. MIN TEMPS WEDNESDAY NIGHT IN THE UPPER 60S TO AROUND 70 NORTH AND LOWER 70S SOUTH. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 310 AM TUESDAY... THURSDAY THROUGH FRIDAY: THURSDAY LOOKS TO BE THE MOST ACTIVE DAY OF THE FORECAST PERIOD AS AN APPROACHING MID LEVEL TROUGH WILL HELP TO SEND A WEAKENING COLD FRONT/SURFACE TROUGH SLOWLY ACROSS THE AREA. MODELS ARE IN GENERAL AGREEMENT IN SHOWING THE FRONT/SURFACE TROUGH LOCATED ACROSS CENTRAL NC DURING DURING PEAK HEATING THURSDAY. THE BEST MLCAPE AND MUCAPE IS EXPECTED TO BE LOCATED ACROSS THE SOUTHEASTERN HALF OF CENTRAL NC.... WHERE 800 TO 1200 J/KG MLCAPE IS EXPECTED... ALONG WITH UPWARDS OF 2000-2500 J/KG OF MUCAPE. THIS COMBINED WITH A MOIST AIR MASS CHARACTERIZED BY PW`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
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
157 PM EDT TUE JUL 8 2014 .SYNOPSIS... UNSETTLED WEATHER CONTINUES THROUGH EARLY WEDNESDAY AS A SERIES OF SYSTEMS PUSH EAST. HIGH PRESSURE BRINGS DRIER AIR TO THE REGION FOR THE END OF THE WEEK. ANOTHER SYSTEM OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... UPDATE... SLOWED THE POPS WITH LIKELIES AFTER 17Z. MAIN PORTION OF THE LEFTOVER MCS DRIFTED NORTHEAST AND MISSED OUR AREA FOR THE MOST PART. WILL BE WAITING FOR CLOUDS TO DISSIPATE...AND THEN EXPECT PERCOLATION THIS AFTERNOON. PREVIOUS DISCUSSION... CUT BACK POP CHCS FOR THE EARLY MORNING HOURS AS OVERNIGHT CONVECTION DIED OFF RAPIDLY WITH THE LOSS OF DAYTIME HEATING. NEAR TERM HI-RES MODELS RUC13 AND HRRR ARE IN FAIR AGREEMENT IN TRANSITIONING ANOTHER CONVECTIVE BAND ACROSS THE FORECAST AREA THIS AFTERNOON. MAIN FLY IN THE OINTMENT IS TRANSITION OF DYING MCS OVER WESTERN ILLINOIS THAT SLIDING TO THE EAST-NORTHEAST AND SHOULD ARRIVE IN CENTRAL OH BY AROUND 15Z. EXPECT MAINLY RESIDUAL SHOWERS AT THIS TIME AND BOUNCED POPS BACK INTO CHC CATEGORY FOR SE OH TO ACCOUNT FOR THIS FEATURE. AFOREMENTIONED CONVECTIVE BAND MAY HAVE SOME TROUBLE DEVELOPING IN POST MCS ENVIRONMENT THIS AFTERNOON...BUT ONCE IT GETS GOING...IT SHOULD MAKE A LITTLE MORE HEADWAY INTO THE CWA AS COMPARED TO PREVIOUS BAND FROM YESTERDAY. LONGWAVE TROUGH OVER THE EASTERN US UNDERGOING AMPLIFICATION... WITH 5H FALLS OVER RLX AREA..AND MID LEVEL FLOW BECOMING MORE CYCLONIC. EXPECT A BETTER CHANCE FOR SVR STORMS TODAY UNDER A MODERATELY UNSTABLE ATMOSPHERE AND BETTER SHEAR ENVIRONMENT. MAIN THREAT WILL BE GUSTY WINDS WITH LINE OF STORMS...AND SOME BOWING LINE SEGMENTS. STORMS WILL ALSO BE EFFICIENT PRECIP PRODUCERS WITH PWATS RUNNING 1.5 TO 2.0 INCHES LATER THIS AFTERNOON. KEPT MENTION OF LOCALLY HEAVY DOWNPOURS. WITH THE RECENT DRY CONDITIONS DO NOT SEE WIDESPREAD WATER PROBLEMS. HOWEVER...HEAVY DOWNPOURS COULD CAUSE LOCAL WATER PROBLEMS IF ANY REPETITIVE SHOWERS OCCUR. USED A BLEND OF BIAS CORRECTED DATA WITH PREVIOUS OFFICIAL FORECAST FOR TEMPS WHICH YIELDED A MINOR TWEAK TO THE TEMP FIELDS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... NAM/GFS/ECMWF/CMC MODELS IN AGREEMENT IN THEIR QPF FIELDS PUSHING LAST RAIN SHOWERS OR THUNDERSTORMS TO THE EASTERN MOUNTAINS... MAINLY ACROSS THE SOUTH EARLY WEDNESDAY MORNING. THIS PCPN ACTIVITY IS ASSOCIATED WITH A SECOND COLD FRONT ENHANCED BY A H5 VORTICITY MAXIMA SINKING SOUTHEAST ACROSS THE AREA. BUFKIT SOUNDINGS INDICATE VERY DRY AIR ALOFT BEHIND THIS FRONT. YET ANOTHER H5 VORTICITY MAXIMA MOVES FROM THE NORTHWEST REACHING OUR EXTREME SOUTHEAST COUNTIES WEDNESDAY AFTERNOON. THEREFORE...DECIDED TO KEEP CHANCE POPS UNTIL THEN BEFORE ENDING ALL BY 00Z THURSDAY. TEMPERATURES WILL DEPEND ON THE DURATION OF CLOUD COVER ESPECIALLY WEDNESDAY AND THURSDAY. GENERALLY STAYED IN THE MID 80S LOWLANDS FOR WEDNESDAY...AND FEW DEGREES COOLER THURSDAY AS FLOW TURNS NORTHWEST TO NORTH BY THE AFTERNOON AND EVENING HOURS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... USED A BLEND OF THE GFS AND ECMWF FOR FRIDAY. THIS LEAVES THE AREA UNDER A HIGH PRESSURE SYSTEM...BUT A BIT OF MOISTURE REMAINS IN THE NORTHERN MOUNTAINS....SO CAN NOT RULE OUT A THUNDERSTORM. FOR SATURDAY THROUGH MONDAY...SWITCHED TO A BLEND OF THE GFS/GEFS ENSEMBLE MEAN AND ECMWF ENSEMBLE MEAN. THIS BRINGS A SYSTEM INTO THE CENTRAL APPALACHIANS OVER THE WEEKEND...LINGERING INTO MONDAY. && .AVIATION /17Z TUESDAY THROUGH SATURDAY/... LINE OF CONVECTION HAS DEVELOPED QUICKLY AND WILL BE CROSSING THE OHIO RIVER SOON. CKB...EKN...AND PKB ARE IN A SEVERE THUNDERSTORM WATCH...PRIMARILY FOR WIND...BUT AS OF RIGHT NOW WITH THE APPROACHING LINE...WINDS ALOFT ARE PARALLEL TO THE LINE AS IT MOVES TO THE EAST. THIS WILL HAMPER THE WIND GUSTS SOMEWHAT...SO WILL KEEP TAF GUSTS BELOW 40KTS. TIMING THE LINE IS USUALLY TRICKY...AND THIS IS NO EXCEPTION. TEMPOS WERE A NECESSITY TODAY BECAUSE OF THIS...BUT WORKED TO KEEP THEM UNDER 2 HOURS. MAY GET SOME REDEVELOPMENT LATER THIS AFTERNOON/EVENING...BUT THE THREAT FOR ISOLATED SHOWERS AND STORMS WILL RETURN. WINDS WILL GUST OUT OF THE SOUTHWEST TO 25KTS. THERE WILL BE A FRONTAL PASSAGE IN THE NEXT TWO HOURS...BUT THE WIND SHIFT WILL BE MINIMAL TO NONE...AND IT SHOULD NOT AFFECT VELOCITIES AS MUCH AS THE LINE OF STORMS. GETTING INTO TONIGHT BECOMES CHALLENGING AS WELL. LOCALES RECEIVING RAIN...AS TYPICAL...WILL HAVE A BETTER SHOT AT FOG...ALTHOUGH IT APPEARS THE WIND MAY TRY TO STAY ABOVE CALM. THIS WILL MAKE FOG/MIST DEVELOPMENT QUESTIONABLE...BUT THE SYNOPTIC WIND MAY BE TRUMPED BY MESO HIGH AIR FROM CONVECTION EARLIER IN THE PERIOD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY... FORECAST CONFIDENCE: LOW TO MEDIUM. ALTERNATE SCENARIOS: CONFIDENCE IS HIGH WITH THE CONVECTIVE OCCURRENCES...JUST NOT THE TIMING AS MUCH. FOG/MIST TONIGHT IS ALSO IN QUESTION. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY H H H H H H H H H H H M HTS CONSISTENCY H H H H H H H H H H H M BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H M PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z WEDNESDAY... LOCAL IFR IN SHOWERS AND THUNDERSTORMS THROUGH EARLY WEDNESDAY... WITH LINGERING IFR CIGS POSSIBLE THROUGH LATE WEDNESDAY MORNING PARTICULARLY ACROSS HIGHER TERRAIN. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KMC/ARJ NEAR TERM...KMC/26 SHORT TERM...ARJ LONG TERM...RPY AVIATION...26
AREA FORECAST DISCUSSION
NWS TULSA OK
1256 PM CDT TUE JUL 8 2014 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. FRONTAL BOUNDARY SOUTHWEST OK THROUGH EASTERN OK INTO SOUTHWEST MO DRIFTING SOUTHEAST WILL BE FOCUS FOR POTENTIAL THUNDERSTORM DEVELOPMENT. MOST LIKELY TIME FRAME 00Z-06Z. AT THIS TIME...TAF SITES KMLC KFSM MOST LIKELY TO SEE AT LEAST VICINITY THUNDER...SITES KBVO KTUL KRVS LEAST LIKELY. OTHER THAN THUNDERSTORM DEVELOPMENT...VFR. && .PREV DISCUSSION... /ISSUED 1051 AM CDT TUE JUL 8 2014/ DISCUSSION... FRONTAL BOUNDARY IN THE VICINITY OF I-44 FORECAST TO CONTINUE TO DRIFT SOUTH THIS AFTERNOON/TONIGHT THEN STALL LATE TONIGHT BETWEEN I40 AND RED RIVER. LEFT OVER -SHRA FAR NORTHEAST OK FAR NORTHWEST AR DIMINISHING. IN THE SHORT TERM REMOVED NOON - 4PM POPS WHILE LEAVING LATE AFTERNOON POPS NORTH I-40 FOR POTENTIAL REGENERATION THUNDER NEAR BOUNDARY. GW PREV DISCUSSION... /ISSUED 638 AM CDT TUE JUL 8 2014/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. GENERALLY VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AT MOST SITES THIS AFTERNOON AND TONIGHT WHICH MAY BRIEFLY REDUCE CEILINGS AND VISIBILITIES. PREV DISCUSSION... /ISSUED 409 AM CDT TUE JUL 8 2014/ DISCUSSION... THE SOUTHWEST PORTION OF A MCS MOVING THROUGH MISSOURI HAD CLIPPED NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS EARLY THIS MORNING. THIS ACTIVITY SHOULD CONTINUE TO PUSH SOUTHEAST AND DISSIPATE OVER THE CWA DURING THE NEXT COUPLE OF HOURS. AN ADDITIONAL LINE OF CONVECTION WAS ACROSS CENTRAL KANSAS...MOVING TO THE SOUTHEAST. WILL LEAVE SLIGHT CHANCE POPS FOR THE MORNING HOURS ACROSS FAR NORTHEAST OKLAHOMA INTO FAR NORTHWEST ARKANSAS. LATEST HRRR AND LOCAL IN-HOUSE MODEL INDICATE THIS LINE TRYING TO FALL APART JUST BEFORE IT GETS INTO THE CWA THIS MORNING. A COLD FRONT CURRENTLY OVER CENTRAL KANSAS WILL MOVE INTO THE CWA TODAY...SHIFTING WINDS OUT OF THE NORTH NORTHEAST. THIS WILL HELP TEMPS ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS BE A LITTLE COOLER COMPARED TO YESTERDAY. CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY FOR THE NORTHERN PART OF THE CWA AS THE FRONT SAGS SOUTHWARD TO NEAR INTERSTATE 40 BY THIS EVENING. AFTERNOON HEATING COULD ALLOW FOR ENOUGH INSTABILITY TO DEVELOP ALONG THE FRONT THAT SOME THUNDERSTORMS COULD BECOME STRONG TO SEVERE WITH LARGE HAIL AND STRONG WINDS BEING THE MAIN HAZARDS. GREATER CHANCES FOR SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS MUCH OF THE CWA TONIGHT INTO WEDNESDAY AS THE FRONT STALLS OUT NEAR THE RED RIVER BY WEDNESDAY MORNING. PERIODS OF HEAVY RAINFALL MAY BE POSSIBLE ALONG WITH A LIMITED SEVERE POTENTIAL. SLIGHTLY COOLER TEMPS WILL AGAIN BE POSSIBLE WEDNESDAY WITH HIGHS IN THE UPPER 80S/LOWER 90S. THE NEARLY STATIONARY FRONTAL BOUNDARY REMAINS OVER THE REGION WEDNESDAY NIGHT INTO THURSDAY AND THEN BEGINS TO LIFT NORTHWARD THURSDAY AS A WARM FRONT. THUS...WILL KEEP AT LEAST SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS GOING THROUGH THURSDAY. A RIDGE OF HIGH PRESSURE BUILDS BACK OVER THE SOUTHERN PLAINS IN THE WAKE OF THE EXITING FRONTAL BOUNDARY AND SHORTWAVE TROF AXIS MOVING ACROSS THE MIDWEST. THIS WILL ALLOW FOR SOUTHERLY WINDS ALONG WITH HOT AND HUMID CONDITIONS TO RETURN TO EASTERN OKLAHOMA AND NORTHWEST ARKANSAS FOR THE WEEKEND. HIGH TEMPS NEAR 100 DEGREES WILL AGAIN BE POSSIBLE FOR PARTS OF EASTERN OKLAHOMA. THESE HOT TEMPS COULD BE SHORT LIVED AS EXTENDED MODEL SOLUTIONS CONTINUE TO SHOW A LOW PRESSURE SYSTEM DROPPING OUT OF CANADA INTO THE GREAT LAKES REGION WITH A COLD FRONT PUSHING ACROSS THE PLAINS FOR THE FIRST PART OF NEXT WEEK. THERE REMAINS TIMING AND STRENGTH DIFFERENCES WITH THIS SYSTEM...THOUGH SOME COOLER TEMPS AND PRECIP CHANCES LOOK POSSIBLE ACROSS THE CWA. && .PRELIMINARY POINT TEMPS/POPS... TUL 93 69 90 71 / 20 30 10 30 FSM 96 72 89 72 / 20 40 30 30 MLC 96 73 91 73 / 10 40 20 30 BVO 90 66 89 69 / 20 20 10 30 FYV 90 66 86 66 / 30 40 10 20 BYV 90 66 86 66 / 30 30 10 20 MKO 95 70 89 71 / 20 30 20 30 MIO 90 65 88 66 / 20 20 10 20 F10 96 71 90 72 / 10 30 20 30 HHW 96 74 93 73 / 10 20 30 30 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...21 LONG TERM....07 AVIATION...21
AREA FORECAST DISCUSSION
NWS PORTLAND OR
219 PM PDT TUE JUL 8 2014 .SYNOPSIS...AN UPPER LEVEL TROUGH MOVING ACROSS BRITISH COLUMBIA TONIGHT AND WEDNESDAY WILL SUPPRESS THE FOUR-CORNERS HIGH AND ALLOW A SLIGHT INCREASE IN ONSHORE LOW-LEVEL FLOW. IT WILL BE A FEW DEGREES COOLER INLAND WEDNESDAY WITH ANY INSTABILITY PUSHED WELL EAST. THE FOUR-CORNERS HIGH EXPANDS NORTH AGAIN LATE IN THE WEEK AND OVER THE WEEKEND. A MOIST SOUTH MID-LEVEL FLOW MAY RETURN FRIDAY AND PERSIST THROUGH THE WEEKEND FOR A THREAT OF THUNDERSTORMS. && .SHORT TERM...THROUGH FRIDAY... WATER VAPOR IMAGERY EARLY THIS AFTERNOON SHOWING A 594 DM HIGH PRES CENTER SQUARELY OVER THE FOUR-CORNERS REGION...WITH A SOUTHEAST TO NORTHWEST ORIENTED RIDGE AXIS EXTENDING THROUGH NORTHWEST OREGON. MID AND HIGH-LEVEL MOISTURE...GENERALLY ABOVE 15000 FT MSL...HAS REACHED THE COLUMBIA RIVER. THERE LOOKS TO BE A SHORT-WAVE DISTURBANCE JUST OFF THE S OREGON COAST...CLOSE TO THE 6-HR GFS FORECAST. AS OF 20Z NO LIGHTNING DETECTED OVER NRN CA...THE NRN SIERRAS...AND MORE IMPORTANTLY OVER THE NRN CA SISKIYOUS CLOSEST TO THE SHORT-WAVE DISTURBANCE. OVERALL PATTERN REMAINS BASICALLY UNCHANGED FROM YESTERDAYS MODEL RUNS. BIGGEST FORECAST CHALLENGE REMAINS POTENTIAL THUNDERSTORM DEVELOPMENT. ANY THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON AND THIS EVENING FAVORS THE LANE COUNTY CASCADES...BUT WILL HAVE TO WATCH FOR ANYTHING WESTWARD. 12Z MODEL SOUNDINGS FOR KEUG AND FOR A POINT IN THE N OREGON CASCADES DO NOT SEEM TOO SUPPORTIVE FOR ANY THUNDERSTORM DEVELOPMENT. BASICALLY TOO MUCH CIN TO OVERCOME AND A STRONG MID-LEVEL INVERSION TO BREAK. 18Z HRRR RUN BRINGS SOME 25-30 DBZ ECHOES INTO SERN LANE COUNTY AROUND 06Z WED...THEN QUICKLY DISSIPATING BY 08Z. 19Z RAP40 RUN NOT VERY IMPRESSIVE EITHER...KEEPING THE HIGHEST SURFACE-BASED CONVECTIVE AVAILABLE POTENTIAL ENERGY (CAPE) VALUES ALONG THE OREGON CASCADE CREST FROM ABOUT MT. JEFFERSON SOUTHWARD BEGINNING LATE THIS AFTERNOON...THEN SHIFTING TO THE EAST CASCADE SLOPES IN THE EARLY EVENING. THE RAP40 700 MB STREAMLINE FORECAST ALSO SHOWS MORE WEST COMPONENT BEGINNING 00Z WED...FURTHER DIMINISHING THUNDERSTORM POTENTIAL. OPTED TO DELAY ANY MENTION OF THUNDERSTORMS TO 00Z WED. NOT 100 PERCENT CONFIDENT ENOUGH TO REMOVE THEM COMPLETELY FROM THE FORECAST. UPPER LEVEL TROUGH MOVES ACROSS BRITISH COLUMBIA LATE TONIGHT AND WEDNESDAY. THIS WILL STRENGTHEN THE WLY FLOW ALOFT OVER THE AREA AND INCREASE THE ONSHORE LOW-LEVEL FLOW. EXPECT GREATER COVERAGE OF MARINE CLOUDS WED MORNING...BUT THE PRIMARY IMPACT WILL BE A FEW DEGREES OF COOLING AND...ACCORDING TO MODEL GUIDANCE...LOWER DEW POINTS. SLIGHTLY WARMER THURSDAY WITH A LITTLE INCREASE IN 500 MB HEIGHTS AND GFS 850 MB TEMPS GOING FROM 16C WED TO 18C THU. GFS AND ECMWF SHOW THE 4-CORNERS HIGH EXPANDING NORTHWEST AGAIN FRI WITH A SHORT-WAVE ALONG THE N CA AND SRN OREGON COAST EMBEDDED WITHIN SOUTH FLOW ALOFT. IN OTHER WORDS...A CLASSICAL THUNDERSTORM PATTERN AND SOMETHING THAT HAS BEEN MENTIONED...ESPECIALLY TO THE FIRE WEATHER CUSTOMERS...FOR THE PAST COUPLE OF DAYS. WEISHAAR .LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...A WEAK UPPER-LEVEL SHORTWAVE IS FORECAST TO ROTATE INTO THE REGION FROM THE SOUTH LATE FRIDAY. THIS MAY BRING ENOUGH FORCING TO TRIGGER A FEW SHOWERS OR THUNDERSHOWERS IN THE NORTH OREGON AND LANE COUNTY CASCADES THROUGH FRIDAY EVENING. ANOTHER MORE SUBSTANTIAL UPPER-LEVEL LOW WILL THEN APPROACH THE COAST LATE SATURDAY INTO SUNDAY. DEPENDING ON THE TIMING AND POSITIONING OF THE TROUGH...THIS MAY PROVIDE AN EVEN BETTER CHANCE FOR THUNDER ON SUNDAY. FORECAST SOUNDINGS INDICATED INCREASING MID-LEVEL MOISTURE AND SUFFICIENT INSTABILITY TO JUSTIFY ADDING A SLIGHT CHANCE OF THUNDER SUNDAY AFTERNOON. A RIDGE BUILDS IN BEHIND THE DEPARTING TROUGH EARLY NEXT WEEK...BRINGING A RETURN TO THE TYPICAL SUMMER-TIME NORTHWESTERLY FLOW REGIME. && .AVIATION...VFR CONDITIONS THIS AFTERNOON...EXCEPT FOR THE CENTRAL OREGON COAST NEAR KONP WHERE MARINE STRATUS IS RESULTING IN IFR CIGS. GUSTY NORTHERLY WINDS ALONG THE COAST THIS AFTERNOON WILL WEAKEN TONIGHT. MARINE STRATUS WILL FILL IN ALONG THE COAST LATE THIS AFTERNOON WITH IFR CIGS. THE STRATUS WILL PUSH IN THROUGH THE COASTAL GAPS THIS EVENING WITH MVFR CIGS REACHING KKLS AROUND 07Z AND KPDX AROUND 13Z. PATCHES OF STATUS WILL FORM AGAIN IN THE WILLAMETTE VALLEY EARLY WED...WITH A GREATER EMPHASIS FOR THE FOOTHILLS AND NORTHERN VALLEY...AND DO NOT EXPECT KSLE OR KEUG TO BE IMPACTED MUCH. KPDX AND APPROACHES...VFR CONDITIONS THIS AFTERNOON AND EVENING. HIGH LEVEL CLOUDS WILL INCREASE IN COVERAGE THIS EVENING. MVFR CIGS FROM STRATUS EXPECTED BETWEEN 12Z AND 17Z ON WED. TJ && .MARINE...HIGH PRESSURE OVER THE NE PACIFIC AND LOW PRESSURE TO THE SOUTH WILL CONTINUE NORTHERLY WINDS FOR THE NEXT 7 DAYS OR SO. THE PRESSURE GRADIENT WILL BE TIGHT ENOUGH TO GENERATE SMALL CRAFT WINDS THROUGH THURSDAY...ESPECIALLY BEYOND 20 NM FROM SHORE. THE GRADIENT WILL BE FAIRLY WEAK FRIDAY THROUGH NEXT MONDAY AND THE WIND DIRECTION WILL OCCASIONALLY HAVE MORE OF A WESTERLY COMPONENT. THE SEAS WILL BE DRIVEN BY THE LOCAL WINDS MAKING WIND WAVES AND FRESH SWELL DIFFICULT TO DISTINGUISH AND HAVE COMBINED THE SEAS THROUGH SATURDAY. THE WINDS WILL BE STEEP AT TIMES AND WARRANT SMALL CRAFT ADVISORIES. TJ && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 2 AM PDT THURSDAY FOR WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR FROM 10 TO 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM NOON WEDNESDAY TO 11 AM PDT THURSDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THIS EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO TO FLORENCE OR OUT 10 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 AM PDT WEDNESDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. && $$ MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
319 PM CDT TUE JUL 8 2014 .DISCUSSION... CURRENTLY...AN OUTFLOW BOUNDARY FROM THE EARLIER MCS KICKED OFF ISOLD TO SCT TSTMS THAT ARE NOW MOVING OFF INTO ALABAMA. OTRW THINGS ARE FAIRLY QUIET WITH CONVECTIVE DEBRIS CLOUDINESS ACROSS THE REGION. THE AIRMASS HAS BEEN SLOWLY RECOVERING ACROSS THE NORTH AS TEMPS CLIMB BACK INTO THE 80S WITH DEWPOINTS IN THE LOWER 70S. THE APPROACHING COLD FRONT IS LOCATED OVER SOUTHERN MISSOURI. TONIGHT...THE COLD FRONT WILL PUSH INTO NORTHERN SECTIONS OF THE MIDSOUTH THIS EVENING. THE AIRMASS WILL CONTINUE TO RECOVER OVER THE NEXT COUPLE OF HOURS AND SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN SECTIONS OF THE MIDSOUTH AS THE FRONT MOVES IN. THE 16Z HRRR DEPICTS THIS SCENARIO WITH CONVECTION PUSHING SOUTHWARD WITH THE FRONT THROUGH THE NIGHT. A FEW STRONG TO SEVERE STORMS WITH LOCALLY HEAVY RAIN ARE POSSIBLE AS THE FRONT PUSHES THROUGH. THE BETTER CHANCE FOR SEVERE STORMS WILL BE NORTH OF THE MS/TN BORDER WHERE MID LEVEL WINDS ARE STRONGER WHICH WILL AID STORM ORGANIZATION. CURRENT HWO HANDLES THIS WELL. RAIN CHANCE WILL SHIFT SOUTH AFTER MIDNIGHT AS THE FRONT MOVES INTO NORTH MISSISSIPPI. WEDNESDAY AND THURSDAY...THE FRONT WILL STALL OVER NORTH MISSISSIPPI OR JUST TO THE SOUTH AND GRADUALLY WEAKEN. THERE WILL BE SCT-NUMEROUS STORMS OVER NORTH MISSISSIPPI BY WED AFTERNOON AND SOME OF THESE STORMS COULD BE STRONG TO SEVERE. HIGH PRESSURE BUILDING INTO NORTHERN SECTIONS OF THE MID SOUTH WILL RESULT IN A PLEASANT DAY WITH HIGHS IN THE 80S. RAIN CHANCES WILL DIMINISH ACROSS NORTH MISSISSIPPI WED NIGHT INTO THURSDAY WITH DRY WEATHER ACROSS NORTHERN SECTIONS. HIGHS IN THE UPPER 80S TO AROUND 90. FRIDAY INTO SUNDAY...UPPER RIDGE STARTS TO BUILD INTO THE AREA WITH WARMING TEMPS. LOW SUMMERTIME POPS. DID NOT GET AS AGGRESSIVE AS THE MEX WITH RESPECT TO HIGH TEMPS. MONDAY AND TUESDAY...UPPER TROF MOVING INTO THE GREAT LAKES WILL PUSH ANOTHER FRONT ACROSS THE MIDSOUTH WITH CHANCE FOR SHOWERS AND THUNDERSTORMS. COOLER BY TUESDAY. SJM && .AVIATION... VFR CONDITIONS SHOULD PERSIST FOR MOST OF THE FORECAST PERIOD. A FEW SHOWERS WERE WEAKENING AS THEY MOVE ACROSS NORTHEAST ARKANSAS. ANOTHER ROUND IF THUNDERSTORMS IS EXPECTED TO START THIS EVENING AND CONTINUE INTO THE OVERNIGHT HOURS. THESE THUNDERSTORMS MAY PRODUCE MVFR VISIBILITIES AT TIMES. WINDS WILL BE MAINLY SOUTHWEST AT 5 TO 10 KNOTS THIS AFTERNOON BEFORE GRADUALLY SHIFTING TO THE WEST THIS EVENING AND TO THE NORTHWEST BY WEDNESDAY MORNING. ARS && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1236 PM CDT TUE JUL 8 2014 .DISCUSSION... UPDATED FOR THE 18Z AVIATION DISCUSSION && .PREV DISCUSSION... /ISSUED 1102 AM CDT TUE JUL 8 2014/ DISCUSSION... THE REMNANTS OF THE MCS THAT MOVED ACROSS THE ENTIRE STATE OF MISSOURI IS NOW EXITING THE FORECAST AREA NEAR THE TN RIVER. ANOTHER MCS THAT FORMED OVER SOUTHERN MISSOURI THIS MORNING IS WEAKENING ACROSS NE ARKANSAS. THESE SYSTEMS HAVE MOVED WELL OUT IN ADVANCE OF THE COLD FRONT AND HAVE STABILIZED THE AIRMASS ACROSS THE NORTHERN HALF OF THE MIDSOUTH. AS A RESULT OF THE MORNING CLOUDS AND PRECIP HAVE KNOCKED DOWN HIGH TEMPS ACROSS THE NORTHERN HALF OF THE FORECAST AREA BY A COUPLE OF DEGREES. WILL HAVE TO SEE HOW THE AIRMASS RECOVERS THIS AFTERNOON AS THE ACTUAL COLD FRONT...CURRENTLY LOCATED OVER SOUTHERN MISSOURI...APPROACHES. THE 13Z HRRR IS NOT VERY BULLISH. WILL CONSIDER REDUCING POPS ACROSS THE NORTH FOR THIS AFTERNOON. SJM PREV DISCUSSION... /ISSUED 533 AM CDT TUE JUL 8 2014/ UPDATE... OUTFLOW FROM A DECAYING MCS OVERNIGHT HAS PUSHED A QUICK MOVING LINE OF NUMEROUS SHOWERS AND THUNDERSTORMS INTO THE FORECAST AREA. HAVE UPPED POPS TO LIKELYS ALONG AND NORTH OF THE I-40 CORRIDOR...WITH CHANCE POPS ACROSS NORTH MISSISSIPPI AND ALSO INCREASED CLOUD COVER. THESE SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DECREASE IN COVERAGE AND INTENSITY BY LATE MORNING BEFORE REDEVELOPMENT LATER THIS AFTERNOON. AC3 PR EV DISCUSSION... /ISSUED 436 AM CDT TUE JUL 8 2014/ DISCUSSION... CURRENTLY... AS OF 4AM...TEMPERATURES ARE QUITE WARM ACROSS THE REGION WITH READINGS IN THE MID TO UPPER 70S AREA WIDE. SOME SHOWERS AND THUNDERSTORMS WERE ALREADY MOVING INTO THE NORTHERN PARTS OF THE FORECAST AREA...SPAWNED FROM A SLOWLY DECAYING MACS LOCATED OVER THE SOUTHERN MISSOURI AND NORTHERN ARKANSAS BORDER. CONVECTION SHOULD BEGIN TO DIMINISH AS WE APPROACH SUNRISE AS THE OUTFLOW OUTPACES THE MAIN CONVECTION. LATEST SURFACE ANALYSIS PLACES A COLD FRONT FROM NORTHERN ILLINOIS...BACK THROUGH SAINT LOUIS...AND INTO NORTHWEST ARKANSAS. SHORT TERM...TODAY THROUGH THURSDAY... THE AFOREMENTIONED COLD FRONT WILL CONTINUE TO MOVE SOUTHEAST INTO THE FORECAST AREA LATER THIS AFTERNOON WITH THE AID OF A SHORTWAVE TROUGH LOCATED NEAR THE IOWA/MISSOURI BORDER. SOME MORNING CONVECTION CANNOT BE RULED OUT...MAINLY NORTH OF THE I-40 CORRIDOR...WHERE A FEW OUTFLOW BOUNDARIES MAY INTERACT WITH A RELATIVELY UNSTABLE AIR MASS. BY THIS AFTERNOON...SB CAPE VALUES ARE EXPECTED TO BE IN EXCESS OF 2500 J/KG...LI`S -8 TO -10...AND MID LEVEL LAPSE RATES AROUND 7 C/KM. 0-6 KM BULK SHEAR WILL BE WEAK AT 20 KNOTS OR SO...HOWEVER THESE PARAMETERS WILL STILL SUPPORT AT LEAST A FEW STRONG TO SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO THE LATE EVENING HOURS. IN ADDITION...PRECIPITATELY WATER VALUES WILL BE AROUND 2.0 INCHES. THE PRIMARY THREATS WILL BE DAMAGING WINDS...LARGE HAIL...AND FLASH FLOODING. THE FRONT IS EXPECTED TO STALL OUT ACROSS NORTH MISSISSIPPI BY WEDNESDAY AFTERNOON. ALONG AND SOUTH OF WHERE THE FRONT ACTUALLY STALLS...ANOTHER POTENTIAL FOR A FEW STRONG TO SEVERE THUNDERSTORMS WILL EXIST IN THE WARM SECTOR DURING THE AFTERNOON HOURS WITH THE SAME PREVIOUSLY MENTIONED THREATS. UNDERCUT GUIDANCE BY A FEW DEGREES FOR WEDNESDAY DUE TO THE ABUNDANT CLOUD COVER AND ONGOING CONVECTION. BY THURSDAY...THE FRONT WILL PUSH A LITTLE FURTHER SOUTH...AND CONTINUE TO SUPPORT AT LEAST AN ISOLATED CHANCE OF SHOWERS AND THUNDERSTORMS IN THE EXTREME SOUTHERN PART OF OUR FORECAST AREA. SURFACE HIGH PRESSURE IS EXPECTED TO BUILD INTO THE NORTHERN PORTIONS OF THE MID-SOUTH BY THURSDAY NIGHT PUTTING AN END TO THE RAIN CHANCES IN THAT AREA. LONG TERM...FRIDAY THROUGH EARLY NEXT WEEK... MODEL GUIDANCE IS IN PRETTY GOOD AGREEMENT THAT THE FRONT WILL LIKELY LIFT NORTH ON FRIDAY AFTERNOON AS A WARM FRONT AS SURFACE HIGH PRESSURE LIFTS OUT TO THE NORTHEAST. SOME SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE DURING THE DAY...BUT SHOULD ONLY WARRANT A MENTION OF SLIGHT POPS ACROSS THE MAJORITY OF THE REGION. BY THIS WEEKEND...MODEL GUIDANCE IS STILL NOT IN VERY GOOD AGREEMENT ABOUT THE UPPER LEVEL PATTERN OVER MID-SOUTH...HOWEVER THEY DO AGREE ON TEMPERATURES REACHING INTO THE LOW TO MID 90S. THE GFS IS OPTIMISTIC ABOUT UPPER LEVEL RIDGING...WHILE THE EURO KEEPS US IN NORTHWEST FLOW ALOFT THROUGH EARLY NEXT WEEK. SINCE THE EURO IS MOST CONSISTENT IN THE MID TERM...WILL CONTINUE TO CARRY AT LEAST THE THREAT OF DAYTIME DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS. BY EARLY NEXT WEEK...ANOTHER COLD FRONT APPEARS TO DROP INTO THE MID-SOUTH ON MONDAY EVENING INTO TUESDAY. FOR NOW...WILL ADVERTISE SLIGHT CHANCE POPS THROUGH THAT TIME FRAME. AC3 && .AVIATION... VFR CONDITIONS SHOULD PERSIST FOR MOST OF THE FORECAST PERIOD. A FEW SHOWERS WERE WEAKENING AS THEY MOVE ACROSS NORTHEAST ARKANSAS. ANOTHER ROUND IF THUNDERSTORMS IS EXPECTED TO START THIS EVENING AND CONTINUE INTO THE OVERNIGHT HOURS. THESE THUNDERSTORMS MAY PRODUCE MVFR VISIBILITIES AT TIMES. WINDS WILL BE MAINLY SOUTHWEST AT 5 TO 10 KNOTS THIS AFTERNOON BEFORE GRADUALLY SHIFTING TO THE WEST THIS EVENING AND TO THE NORTHWEST BY WEDNESDAY MORNING. ARS && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1102 AM CDT TUE JUL 8 2014 .DISCUSSION... THE REMNANTS OF THE MCS THAT MOVED ACROSS THE ENTIRE STATE OF MISSOURI IS NOW EXITING THE FORECAST AREA NEAR THE TN RIVER. ANOTHER MCS THAT FORMED OVER SOUTHERN MISSOURI THIS MORNING IS WEAKENING ACROSS NE ARKANSAS. THESE SYSTEMS HAVE MOVED WELL OUT IN ADVANCE OF THE COLD FRONT AND HAVE STABILIZED THE AIRMASS ACROSS THE NORTHERN HALF OF THE MIDSOUTH. AS A RESULT OF THE MORNING CLOUDS AND PRECIP HAVE KNOCKED DOWN HIGH TEMPS ACROSS THE NORTHERN HALF OF THE FORECAST AREA BY A COUPLE OF DEGREES. WILL HAVE TO SEE HOW THE AIRMASS RECOVERS THIS AFTERNOON AS THE ACTUAL COLD FRONT...CURRENTLY LOCATED OVER SOUTHERN MISSOURI...APPROACHES. THE 13Z HRRR IS NOT VERY BULLISH. WILL CONSIDER REDUCING POPS ACROSS THE NORTH FOR THIS AFTERNOON. SJM && PREV DISCUSSION... /ISSUED 533 AM CDT TUE JUL 8 2014/ UPDATE... OUTFLOW FROM A DECAYING MCS OVERNIGHT HAS PUSHED A QUICK MOVING LINE OF NUMEROUS SHOWERS AND THUNDERSTORMS INTO THE FORECAST AREA. HAVE UPPED POPS TO LIKELYS ALONG AND NORTH OF THE I-40 CORRIDOR...WITH CHANCE POPS ACROSS NORTH MISSISSIPPI AND ALSO INCREASED CLOUD COVER. THESE SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DECREASE IN COVERAGE AND INTENSITY BY LATE MORNING BEFORE REDELOPMENT LATER THIS AFTERNOON. AC3 PREV DISCUSSION... /ISSUED 436 AM CDT TUE JUL 8 2014/ DISCUSSION... CURRENTLY... AS OF 4AM...TEMPERATURES ARE QUITE WARM ACROSS THE REGION WITH READINGS IN THE MID TO UPPER 70S AREA WIDE. SOME SHOWERS AND THUNDERSTORMS WERE ALREADY MOVING INTO THE NORTHERN PARTS OF THE FORECAST AREA...SPAWNED FROM A SLOWLY DECAYING MCS LOCATED OVER THE SOUTHERN MISSOURI AND NORTHERN ARKANSAS BORDER. CONVECTION SHOULD BEGIN TO DIMINISH AS WE APPROACH SUNRISE AS THE OUTFLOW OUTPACES THE MAIN CONVECTION. LATEST SURFACE ANALYSIS PLACES A COLD FRONT FROM NORTHERN ILLINOIS...BACK THROUGH SAINT LOUIS...AND INTO NORTHWEST ARKANSAS. SHORT TERM...TODAY THROUGH THURSDAY... THE AFOREMENTIONED COLD FRONT WILL CONTINUE TO MOVE SOUTHEAST INTO THE FORECAST AREA LATER THIS AFTERNOON WITH THE AID OF A SHORTWAVE TROUGH LOCATED NEAR THE IOWA/MISSOURI BORDER. SOME MORNING CONVECTION CANNOT BE RULED OUT...MAINLY NORTH OF THE I-40 CORRIDOR...WHERE A FEW OUTFLOW BOUNDARIES MAY INTERACT WITH A RELATIVELY UNSTABLE AIRMASS. BY THIS AFTERNOON...SBCAPE VALUES ARE EXPECTED TO BE IN EXCESS OF 2500 J/KG...LI`S -8 TO -10...AND MID LEVEL LAPSE RATES AROUND 7 C/KM. 0-6 KM BULK SHEAR WILL BE WEAK AT 20 KNOTS OR SO...HOWEVER THESE PARAMETERS WILL STILL SUPPORT AT LEAST A FEW STRONG TO SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO THE LATE EVENING HOURS. IN ADDITION...PRECIPITABLE WATER VALUES WILL BE AROUND 2.0 INCHES. THE PRIMARY THREATS WILL BE DAMAGING WINDS...LARGE HAIL...AND FLASH FLOODING. THE FRONT IS EXPECTED TO STALL OUT ACROSS NORTH MISSISSIPPI BY WEDNESDAY AFTERNOON. ALONG AND SOUTH OF WHERE THE FRONT ACTUALLY STALLS...ANOTHER POTENTIAL FOR A FEW STRONG TO SEVERE THUNDERSTORMS WILL EXIST IN THE WARM SECTOR DURING THE AFTERNOON HOURS WITH THE SAME PREVIOUSLY MENTIONED THREATS. UNDERCUT GUIDANCE BY A FEW DEGREES FOR WEDNESDAY DUE TO THE ABUNDANT CLOUD COVER AND ONGOING CONVECTION. BY THURSDAY...THE FRONT WILL PUSH A LITTLE FURTHER SOUTH...AND CONTINUE TO SUPPORT AT LEAST AN ISOLATED CHANCE OF SHOWERS AND THUNDERSTORMS IN THE EXTREME SOUTHERN PART OF OUR FORECAST AREA. SURFACE HIGH PRESSURE IS EXPECTED TO BUILD INTO THE NORTHERN PORTIONS OF THE MID-SOUTH BY THURSDAY NIGHT PUTTING AN END TO THE RAIN CHANCES IN THAT AREA. LONG TERM...FRIDAY THROUGH EARLY NEXT WEEK... MODEL GUIDANCE IS IN PRETTY GOOD AGREEMENT THAT THE FRONT WILL LIKELY LIFT NORTH ON FRIDAY AFTERNOON AS A WARM FRONT AS SURFACE HIGH PRESSURE LIFTS OUT TO THE NORTHEAST. SOME SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE DURING THE DAY...BUT SHOULD ONLY WARRANT A MENTION OF SLIGHT POPS ACROSS THE MAJORITY OF THE REGION. BY THIS WEEKEND...MODEL GUIDANCE IS STILL NOT IN VERY GOOD AGREEMENT ABOUT THE UPPER LEVEL PATTERN OVER MID-SOUTH...HOWEVER THEY DO AGREE ON TEMPERATURES REACHING INTO THE LOW TO MID 90S. THE GFS IS OPTIMISTIC ABOUT UPPER LEVEL RIDGING...WHILE THE EURO KEEPS US IN NORTHWEST FLOW ALOFT THROUGH EARLY NEXT WEEK. SINCE THE EURO IS MOST CONSISTENT IN THE MID TERM...WILL CONTINUE TO CARRY AT LEAST THE THREAT OF DAYTIME DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS. BY EARLY NEXT WEEK...ANOTHER COLD FRONT APPEARS TO DROP INTO THE MID-SOUTH ON MONDAY EVENING INTO TUESDAY. FOR NOW...WILL ADVERTISE SLIGHT CHANCE POPS THROUGH THAT TIME FRAME. AC3 && .AVIATION... 12Z TAF CYCLE A LINE OF THUNDERSTORMS CONTINUES TO MOVE SOUTHEAST AND WILL IMPACT BOTH KMEM AND KMKL THROUGH 13Z. STRONG WIND GUSTS UP TO 35 KTS WILL BE POSSIBLE AS THE LINE MOVES THROUGH. THIS LINE OF STORMS WILL BREAK UP OVER THE NEXT HOUR OR TWO AND UNLIKELY TO REACH KTUP. ADDITIONAL STORMS WILL REDEVELOP LATER THIS AFTERNOON AND EVENING AND SHOULD IMPACT ALL SITES. PREVAILING WINDS SHOULD BE FROM THE SOUTHWEST AROUND 10-12 KTS OUTSIDE OF THUNDERSTORMS. VFR CIGS AND VSBYS SHOULD REMAIN THE PREDOMINATE CONDITION...WITH ONLY BRIEF LOWERING POSSIBLE IN STRONGER THUNDERSTORMS. WINDS SHOULD DROP BELOW 7 KTS TONIGHT AT ALL TERMINALS. CONVECTIVE COVERAGE SHOULD DIMINISH LATER THIS EVENING AND OVERNIGHT...BUT IS SOMEWHAT UNCERTAIN AT THIS TIME AND WILL BE MODULATED BY MESOSCALE PROCESSES. JLH && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
601 PM EDT TUE JUL 8 2014 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT AND WEDNESDAY...BEFORE CROSSING THROUGH THE AREA WEDNESDAY NIGHT. HIGH PRESSURE WILL FOLLOW THE FRONT FOR THURSDAY INTO SATURDAY. A MUCH STRONGER COLD FRONT WILL BE PASSING THROUGH THE REGION NEXT MONDAY AND TUESDAY. && .NEAR TERM /THROUGH WEDNESDAY/... UPDATED POPS FOR LATEST WSR-88D TRENDS FOR THUNDERSTORMS MOVING ACROSS THE MOUNTAINS AT THIS TIME. SOME OF THE THUNDERSTORMS ARE STRONG TO SEVERE WITH GUSTY WINDS THE MAIN THREAT.MODIFIED TEMPERATURES AND DEW POINTS FOR LATEST OBS AND SHAPED THIS EVENING INTO TONIGHT. AS OF 315 PM EDT TUESDAY... WATER VAPOR LOOP SHOWED THE FIRST OF TWO SHORT WAVES THAT WILL DEEPEN THE NORTHEAST TROF. THE SECOND WAVE CROSSES THE GREAT LAKES THEN INTO THE NORTHEAST WEDNESDAY NIGHT. LAST FEW RUNS OF THE LOCAL WRF AND HRRR WERE VERY CONSISTENT WITH THE TIMING OF A BAND OF THUNDERSTORMS MOVING IN FROM THE WEST...WHAT WAS CURRENTLY DEVELOPING FROM AROUND PITTSBURGH TO NORTHWEST OF CHARLESTON WV. STILL EXPECTING THIS TO REACH SOUTHEAST WEST VIRGINIA BETWEEN 20-22Z/4-6PM. GUSTY SOUTHWEST SURFACE WINDS AND LOW LEVEL MIXING HAS BROUGHT SURFACE DEW POINTS DOWN INTO THE UPPER 50S TO LOWER 60S...SO CAPES HAVE PEAKED AROUND 2000 J/KG. HOWEVER...AS INDICATED WITH A CLASSIC INVERTED V SOUNDING...DCAPE WAS A HIGH AS 1300 J/KG IN THE FAR SOUTHEAST COUNTY WARNING AREA. IF STORMS MANAGE TO GET INTO THIS ENVIRONMENT AND OVERCOME THE DOWNSLOPING EAST OF THE BLUE RIDGE THERE IS A POTENTIAL FOR STRONG TO DAMAGING WINDS. WITH THE REMOVAL OF HEATING...INTENSITY AND COVERAGE OF PRECIPITATION WILL DIMINISH...MAINLY AFTER 02Z/10PM. THE SOUTHERN END OF THE LINE OF STORMS...EXTENDING ACROSS THE TENNESSEE VALLEY MAY CONTINUE OVERNIGHT. HAVE KEPT A HIGHER PROBABILITY OF PRECIPITATION IN THE SOUTHWEST COUNTY WARNING AREA THROUGH WEDNESDAY MORNING. EXPECTING LITTLE PROGRESS IN THE EASTWARD MOVEMENT OF THE SURFACE COLD FRONT TONIGHT AND WEDNESDAY WITH BROAD SOUTHWEST FLOW PARALLEL TO THE BOUNDARY AND LIMITED MOVEMENT OF THE UPPER TROF. BEST PROBABILITY OF PRECIPITATION WEDNESDAY WILL BE IN THE AFTERNOON WITH AREAS OF SURFACE BASED IN STABILITY AND CONVERGENCE...PLUS ALONG ANY OUTFLOW PRODUCED BY THE THUNDERSTORMS THAT DEVELOP THIS AFTERNOON. NARROWING DOWN WHERE THIS WILL BE IS THE BIGGEST CHALLENGE. LOOKING FOR MUGGY CONDITIONS WILL DEW POINTS RISING BACK UP THROUGH THE 60S TONIGHT...ESPECIALLY WHERE IT RAINS. AMOUNT OF CLOUDS WILL DETERMINE HOW HOT TEMPERATURES WILL GET ON WEDNESDAY. WILL BE DEPENDENT ON WHERE IT IS RAINING IN THE MORNING. FOR NOW STAYED CLOSED TO THE MET GUIDANCE FOR MAXIMUM TEMPERATURES. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 310 PM EDT TUESDAY... WEAK COOL FRONT EXPECTED TO DRIFT SOUTHEAST THROUGH THE BLACKSBURG FORECAST AREA WEDNESDAY NIGHT. ACTUAL SURFACE REFLECTION WILL LIKELY BE DIFFICULT TO DEFINE CONSIDERING DIFFUSE NATURE OF FRONT...AND CONTAMINATION FROM COOL OUTFLOW BOUNDARIES GENERATED BY CONVECTIVE ACTIVITY PRECEDING IT. HOWEVER...UPPER TROF WILL REMAIN TO THE WEST...AND WITH SUBTLE BACKING OF LOW LEVEL FLOW EXPECTED AHEAD OF UPPER TROF...ALONG WITH GRADUAL COOLING ALOFT...SUPPORT FOR PRE- AND POST-FRONTAL PRECIPITATION MAY PERSIST WELL INTO THE EVENING...AND PERHAPS THOUGH MUCH OF THE NIGHT ACROSS SOUTHERN/SOUTHEASTERN AREAS. NORTHWESTERN AREAS SHOULD REMAIN DRY...OTHER THAN PERHAPS A LINGERING EARLY EVENING SHOWER. ALTHOUGH NORTHWESTERN AREAS EXPECTED TO REMAIN DRY ON THURSDAY...PROXIMITY OF OLD FRONTAL BOUNDARY LYING JUST TO THE SOUTH AND EAST...AND LIMITED ADDITIONAL MOVEMENT EAST OF UPPER TROF WARRANTS CONTINUED AT LEAST LOW THREAT FOR DIURNALLY DRIVEN SHOWERS OR THUNDERSTORMS ACROSS THE SOUTH AND SOUTHEAST PORTION OF THE FORECAST AREA DURING THE AFTERNOON INTO THE EVENING. UPPER TROF FINALLY EXPECTED TO MOVE OVER AND THEN JUST TO THE EAST OF THE FORECAST AREA ON FRIDAY...BUT PLACEMENT SUPPORTS AMPLIFICATION OF SURFACE RIDGE JUST TO OUR NORTHEAST WHICH ALLOWS LOW LEVEL FLOW TO VEER AROUND BY DAYS END INTO THE EAST. COMBINATION OF COOLER AIR ALOFT...PLENTY OF INSOLATION...AND LIGHT UPSLOPING AGAINST THE EASTERN FLANKS OF THE BLUE RIDGE MAY BE SUFFICIENT TO OVERCOME DEVELOPING CAP TO SUPPORT ISOLATED TO WIDELY SCATTERED CONVECTION ALONG AND EAST OF THE BLUE RIDGE BEFORE DIMINISHING WITH LOSS OF DAYTIME HEATING FRIDAY EVENING. POST FRONTAL TEMPERATURES WILL BE SLIGHTLY COOLER THAN THE PAST SEVERAL DAYS...MAINLY 70S TO AROUND 80 ACROSS THE HIGHER ELEVATIONS TO MAINLY 80S PIEDMONT...WITH 50S IN THE MOUNTAIN VALLEYS TO MAINLY 60S ACROSS THE PIEDMONT AT NIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 310 PM EDT TUESDAY... DAILY THREAT OF WIDELY SCATTERED TO SCATTERED DIURNALLY DRIVEN SHOWERS/THUNDERSTORMS APPEARS TO BE IN THE OFFING DURING THE LONG TERM PERIOD AS A SERIES OF WEAK SHORT WAVES IN RELATIVELY ZONAL FLOW FORECAST TO MOVE EAST THROUGH THE BLACKSBURG FORECAST AREA. FIRST WAVE EXPECTED ON SATURDAY...WITH SECOND WAVE ON SUNDAY...TO BE FOLLOWED BY MUCH MORE SUBSTANTIAL WAVE IN MONDAY/TUESDAY TIMEFRAME AS EASTERN CANADIAN UPPER LOW AMPLIFIES AND RETROGRESSES SOUTHWESTWARD INTO THE UPPER GREAT LAKES AREA. DEEPENING VERY BROAD UPPER TROF/CLOSED SYSTEM WILL SUPPORT A GOOD PUSH OF UNUSUALLY COOL AIR INTO THE MID APPALACHIAN AND MID ATLANTIC REGION BY THE END OF THE LONG TERM PERIOD...BUT WITH THE COOLEST PORTION OF THE AIRMASS TO ARRIVE JUST OUTSIDE OF THIS FORECAST PERIOD...ON WEDNESDAY. AT LEAST THROUGH MONDAY...EXPECT RELATIVELY SEASONAL TEMPERATURES WITH NO SIGNIFICANT DAY TO DAY CHANGES IN AIRMASS. HIGHS SHOULD RANGE FROM THE MID 70S TO LOWER 80S ACROSS THE HIGHER ELEVATIONS TO UPPER 80S TO LOWER 90S ACROSS THE PIEDMONT. OVERNIGHT LOWS SHOULD BE GENERALLY IN THE 60S...BUT WITH SOME UPPER 50S POSSIBLE ACROSS THE HIGHEST ELEVATIONS AND IN THE DEEPER MOUNTAIN VALLEYS. TEMPERATURES SHOULD BEGIN TRENDING DOWNWARD ABOUT 5F DAILY BEGINNING TUESDAY AS LEADING EDGE OF SUCCESSIVE WAVES OF COOLER AIR BEGIN TO IMPINGE UPON THE AREA. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... AS OF 145 PM EDT TUESDAY... COMMS ISSUES REMAIN AT KDAN DESPITE AN INTERMITTENT RETURN OF OBSERVATION DATA. AMD NOT SKED CONTINUED IN THE TAF. BAND OF SHOWERS AND THUNDERSTORMS WILL FORM FROM WESTERN PENNSYLVANIA TO EASTERN KENTUCKY AND MOVE EAST DURING THE EVENING. LAST FEW RUNS OF THE HRRR...AS WELL AS THE RUC AND LOCAL WRF HAVE THE STORMS REACHING KBLF AND KBLF FROM 20-21Z/4-5PM. LOWER CONFIDENCE AS TO HOW FAR EAST SHOWERS AND THUNDERSTORMS WILL PROGRESS. HAVE LEFT VCNTY THUNDER IN THE KBCB...KROA AND KLYH TAFS. THE LEAST LIKELY LOCATION TO GET STORMS WILL BE AT KDAN AS LONG AS SCATTERED TO ISOLATED THUNDERSTORMS DO NOT DEVELOP IN THE FOOTHILLS OF THE BLUE RIDE. AS LOWER DEW POINTS MIX DOWN TO THE SURFACE THIS AFTERNOON...THE INSTABILITY WAS BECOMING LESS FAVORABLE FOR THUNDERSTORMS IN THE LEE-TROF. LOSS OF HEATING AND WESTERLY DOWNSLOPE WIND WILL WEAKEN SHOWERS AND THUNDERSTORMS BY 02Z/10PM. MODELS SHOWED LINGERING SHOWERS FROM SOUTHERN WEST VIRGINIA TO EASTERN TENNESSEE OVERNIGHT. DO NOT HAVE ANY IMPACT FROM THIS POTENTIAL RAINFALL IN THE TAFS BUT HAVE ADDED MVFR CEILINGS TO KBLF AFTER MIDNIGHT. ALSO ADDED LIFR FOG AND CEILINGS IN FOR KLWB OVERNIGHT..EXPECTING THERE WILL BE RAIN AT THAT AIRPORT LATE THIS AFTERNOON. EXTENDED AVIATION... BEST CHANCE FOR THUNDERSTORMS ON WEDNESDAY WILL BE IN THE AFTERNOON IN CENTRAL AND EASTERN VIRGINIA AND NORTH CAROLINA WHERE THE INSTABILITY WILL COMBINE WITH OUTFLOW FROM PREVIOUS STORMS. THE COLD FRONT WILL FINALLY PUSH THROUGH THE REGION ON WEDNESDAY NIGHT. THE FRONT WILL LINGER ACROSS SOUTHERN/EASTERN AREAS THROUGH THE END OF THE WEEK WITH IMPULSES RIDING ALONG IT. THIS WILL KEEP UNSETTLED CONDITIONS AT TAF SITES THROUGH THE END OF THE WEEK. EXPECT DIURNAL TRENDS FOR AFTERNOON CONVECTIVE PRECIPITATION WITH ASSOCIATED MVFR OR LOWER CONDITIONS... ESPECIALLY FOR KDAN/KLYH...AND POSSIBLE IFR FOG LATE NIGHTS...MAINLY KBCB AND KLWB. && .CLIMATE... AS OF 315 PM EDT TUESDAY... THIS WAS THE 3RD DRIEST JUNE ON RECORD AT DANVILLE WITH ONLY 1.23 INCHES OF PRECIPITATION. RECORDS GO BACK TO 1948. THE DRIEST JUNE ON RECORD IS 1.06 INCHES IN 2008. && .EQUIPMENT... AS OF 315 PM EDT TUESDAY... COMMUNICATIONS OUTAGE CONTINUES WITH KDAN ASOS NOT TRANSMITTING. THE FAA IS AWARE OF THE OUTAGE AND WILL BE WORKING ON IT...BUT NO ESTIMATED TIME OF WHEN IT WILL BE WORKING AGAIN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...WERT LONG TERM...AMS/WERT AVIATION...AMS/JH CLIMATE...AMS/PC EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
325 PM EDT TUE JUL 8 2014 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT AND WEDNESDAY...BEFORE CROSSING THROUGH THE AREA WEDNESDAY NIGHT. HIGH PRESSURE WILL FOLLOW THE FRONT FOR THURSDAY INTO SATURDAY. A MUCH STRONGER COLD FRONT WILL BE PASSING THROUGH THE REGION NEXT MONDAY AND TUESDAY. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 315 PM EDT TUESDAY... WATER VAPOR LOOP SHOWED THE FIRST OF TWO SHORT WAVES THAT WILL DEEPEN THE NORTHEAST TROF. THE SECOND WAVE CROSSES THE GREAT LAKES THEN INTO THE NORTHEAST WEDNESDAY NIGHT. LAST FEW RUNS OF THE LOCAL WRF AND HRRR WERE VERY CONSISTENT WITH THE TIMING OF A BAND OF THUNDERSTORMS MOVING IN FROM THE WEST...WHAT WAS CURRENTLY DEVELOPING FROM AROUND PITTSBURGH TO NORTHWEST OF CHARLESTON WV. STILL EXPECTING THIS TO REACH SOUTHEAST WEST VIRGINIA BETWEEN 20-22Z/4-6PM. GUSTY SOUTHWEST SURFACE WINDS AND LOW LEVEL MIXING HAS BROUGHT SURFACE DEW POINTS DOWN INTO THE UPPER 50S TO LOWER 60S...SO CAPES HAVE PEAKED AROUND 2000 J/KG. HOWEVER...AS INDICATED WITH A CLASSIC INVERTED V SOUNDING...DCAPE WAS A HIGH AS 1300 J/KG IN THE FAR SOUTHEAST COUNTY WARNING AREA. IF STORMS MANAGE TO GET INTO THIS ENVIRONMENT AND OVERCOME THE DOWNSLOPING EAST OF THE BLUE RIDGE THERE IS A POTENTIAL FOR STRONG TO DAMAGING WINDS. WITH THE REMOVAL OF HEATING...INTENSITY AND COVERAGE OF PRECIPITATION WILL DIMINISH...MAINLY AFTER 02Z/10PM. THE SOUTHERN END OF THE LINE OF STORMS...EXTENDING ACROSS THE TENNESSEE VALLEY MAY CONTINUE OVERNIGHT. HAVE KEPT A HIGHER PROBABILITY OF PRECIPITATION IN THE SOUTHWEST COUNTY WARNING AREA THROUGH WEDNESDAY MORNING. EXPECTING LITTLE PROGRESS IN THE EASTWARD MOVEMENT OF THE SURFACE COLD FRONT TONIGHT AND WEDNESDAY WITH BROAD SOUTHWEST FLOW PARALLEL TO THE BOUNDARY AND LIMITED MOVEMENT OF THE UPPER TROF. BEST PROBABILITY OF PRECIPITATION WEDNESDAY WILL BE IN THE AFTERNOON WITH AREAS OF SURFACE BASED IN STABILITY AND CONVERGENCE...PLUS ALONG ANY OUTFLOW PRODUCED BY THE THUNDERSTORMS THAT DEVELOP THIS AFTERNOON. NARROWING DOWN WHERE THIS WILL BE IS THE BIGGEST CHALLENGE. LOOKING FOR MUGGY CONDITIONS WILL DEW POINTS RISING BACK UP THROUGH THE 60S TONIGHT...ESPECIALLY WHERE IT RAINS. AMOUNT OF CLOUDS WILL DETERMINE HOW HOT TEMPERATURES WILL GET ON WEDNESDAY. WILL BE DEPENDENT ON WHERE IT IS RAINING IN THE MORNING. FOR NOW STAYED CLOSED TO THE MET GUIDANCE FOR MAXIMUM TEMPERATURES. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 310 PM EDT TUESDAY... WEAK COOL FRONT EXPECTED TO DRIFT SOUTHEAST THROUGH THE BLACKSBURG FORECAST AREA WEDNESDAY NIGHT. ACTUAL SURFACE REFLECTION WILL LIKELY BE DIFFICULT TO DEFINE CONSIDERING DIFFUSE NATURE OF FRONT...AND CONTAMINATION FROM COOL OUTFLOW BOUNDARIES GENERATED BY CONVECTIVE ACTIVITY PRECEDING IT. HOWEVER...UPPER TROF WILL REMAIN TO THE WEST...AND WITH SUBTLE BACKING OF LOW LEVEL FLOW EXPECTED AHEAD OF UPPER TROF...ALONG WITH GRADUAL COOLING ALOFT...SUPPORT FOR PRE- AND POST-FRONTAL PRECIPITATION MAY PERSIST WELL INTO THE EVENING...AND PERHAPS THOUGH MUCH OF THE NIGHT ACROSS SOUTHERN/SOUTHEASTERN AREAS. NORTHWESTERN AREAS SHOULD REMAIN DRY...OTHER THAN PERHAPS A LINGERING EARLY EVENING SHOWER. ALTHOUGH NORTHWESTERN AREAS EXPECTED TO REMAIN DRY ON THURSDAY...PROXIMITY OF OLD FRONTAL BOUNDARY LYING JUST TO THE SOUTH AND EAST...AND LIMITED ADDITIONAL MOVEMENT EAST OF UPPER TROF WARRANTS CONTINUED AT LEAST LOW THREAT FOR DIURNALLY DRIVEN SHOWERS OR THUNDERSTORMS ACROSS THE SOUTH AND SOUTHEAST PORTION OF THE FORECAST AREA DURING THE AFTERNOON INTO THE EVENING. UPPER TROF FINALLY EXPECTED TO MOVE OVER AND THEN JUST TO THE EAST OF THE FORECAST AREA ON FRIDAY...BUT PLACEMENT SUPPORTS AMPLIFICATION OF SURFACE RIDGE JUST TO OUR NORTHEAST WHICH ALLOWS LOW LEVEL FLOW TO VEER AROUND BY DAYS END INTO THE EAST. COMBINATION OF COOLER AIR ALOFT...PLENTY OF INSOLATION...AND LIGHT UPSLOPING AGAINST THE EASTERN FLANKS OF THE BLUE RIDGE MAY BE SUFFICIENT TO OVERCOME DEVELOPING CAP TO SUPPORT ISOLATED TO WIDELY SCATTERED CONVECTION ALONG AND EAST OF THE BLUE RIDGE BEFORE DIMINISHING WITH LOSS OF DAYTIME HEATING FRIDAY EVENING. POST FRONTAL TEMPERATURES WILL BE SLIGHTLY COOLER THAN THE PAST SEVERAL DAYS...MAINLY 70S TO AROUND 80 ACROSS THE HIGHER ELEVATIONS TO MAINLY 80S PIEDMONT...WITH 50S IN THE MOUNTAIN VALLEYS TO MAINLY 60S ACROSS THE PIEDMONT AT NIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 310 PM EDT TUESDAY... DAILY THREAT OF WIDELY SCATTERED TO SCATTERED DIURNALLY DRIVEN SHOWERS/THUNDERSTORMS APPEARS TO BE IN THE OFFING DURING THE LONG TERM PERIOD AS A SERIES OF WEAK SHORT WAVES IN RELATIVELY ZONAL FLOW FORECAST TO MOVE EAST THROUGH THE BLACKSBURG FORECAST AREA. FIRST WAVE EXPECTED ON SATURDAY...WITH SECOND WAVE ON SUNDAY...TO BE FOLLOWED BY MUCH MORE SUBSTANTIAL WAVE IN MONDAY/TUESDAY TIMEFRAME AS EASTERN CANADIAN UPPER LOW AMPLIFIES AND RETROGRESSES SOUTHWESTWARD INTO THE UPPER GREAT LAKES AREA. DEEPENING VERY BROAD UPPER TROF/CLOSED SYSTEM WILL SUPPORT A GOOD PUSH OF UNUSUALLY COOL AIR INTO THE MID APPALACHIAN AND MID ATLANTIC REGION BY THE END OF THE LONG TERM PERIOD...BUT WITH THE COOLEST PORTION OF THE AIRMASS TO ARRIVE JUST OUTSIDE OF THIS FORECAST PERIOD...ON WEDNESDAY. AT LEAST THROUGH MONDAY...EXPECT RELATIVELY SEASONAL TEMPERATURES WITH NO SIGNIFICANT DAY TO DAY CHANGES IN AIRMASS. HIGHS SHOULD RANGE FROM THE MID 70S TO LOWER 80S ACROSS THE HIGHER ELEVATIONS TO UPPER 80S TO LOWER 90S ACROSS THE PIEDMONT. OVERNIGHT LOWS SHOULD BE GENERALLY IN THE 60S...BUT WITH SOME UPPER 50S POSSIBLE ACROSS THE HIGHEST ELEVATIONS AND IN THE DEEPER MOUNTAIN VALLEYS. TEMPERATURES SHOULD BEGIN TRENDING DOWNWARD ABOUT 5F DAILY BEGINNING TUESDAY AS LEADING EDGE OF SUCCESSIVE WAVES OF COOLER AIR BEGIN TO IMPINGE UPON THE AREA. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... AS OF 145 PM EDT TUESDAY... COMMS ISSUES REMAIN AT KDAN DESPITE AN INTERMITTENT RETURN OF OBSERVATION DATA. AMD NOT SKED CONTINUED IN THE TAF. BAND OF SHOWERS AND THUNDERSTORMS WILL FORM FROM WESTERN PENNSYLVANIA TO EASTERN KENTUCKY AND MOVE EAST DURING THE EVENING. LAST FEW RUNS OF THE HRRR...AS WELL AS THE RUC AND LOCAL WRF HAVE THE STORMS REACHING KBLF AND KBLF FROM 20-21Z/4-5PM. LOWER CONFIDENCE AS TO HOW FAR EAST SHOWERS AND THUNDERSTORMS WILL PROGRESS. HAVE LEFT VCNTY THUNDER IN THE KBCB...KROA AND KLYH TAFS. THE LEAST LIKELY LOCATION TO GET STORMS WILL BE AT KDAN AS LONG AS SCATTERED TO ISOLATED THUNDERSTORMS DO NOT DEVELOP IN THE FOOTHILLS OF THE BLUE RIDE. AS LOWER DEW POINTS MIX DOWN TO THE SURFACE THIS AFTERNOON...THE INSTABILITY WAS BECOMING LESS FAVORABLE FOR THUNDERSTORMS IN THE LEE-TROF. LOSS OF HEATING AND WESTERLY DOWNSLOPE WIND WILL WEAKEN SHOWERS AND THUNDERSTORMS BY 02Z/10PM. MODELS SHOWED LINGERING SHOWERS FROM SOUTHERN WEST VIRGINIA TO EASTERN TENNESSEE OVERNIGHT. DO NOT HAVE ANY IMPACT FROM THIS POTENTIAL RAINFALL IN THE TAFS BUT HAVE ADDED MVFR CEILINGS TO KBLF AFTER MIDNIGHT. ALSO ADDED LIFR FOG AND CEILINGS IN FOR KLWB OVERNIGHT..EXPECTING THERE WILL BE RAIN AT THAT AIRPORT LATE THIS AFTERNOON. EXTENDED AVIATION... BEST CHANCE FOR THUNDERSTORMS ON WEDNESDAY WILL BE IN THE AFTERNOON IN CENTRAL AND EASTERN VIRGINIA AND NORTH CAROLINA WHERE THE INSTABILITY WILL COMBINE WITH OUTFLOW FROM PREVIOUS STORMS. THE COLD FRONT WILL FINALLY PUSH THROUGH THE REGION ON WEDNESDAY NIGHT. THE FRONT WILL LINGER ACROSS SOUTHERN/EASTERN AREAS THROUGH THE END OF THE WEEK WITH IMPULSES RIDING ALONG IT. THIS WILL KEEP UNSETTLED CONDITIONS AT TAF SITES THROUGH THE END OF THE WEEK. EXPECT DIURNAL TRENDS FOR AFTERNOON CONVECTIVE PRECIPITATION WITH ASSOCIATED MVFR OR LOWER CONDITIONS... ESPECIALLY FOR KDAN/KLYH...AND POSSIBLE IFR FOG LATE NIGHTS...MAINLY KBCB AND KLWB. && .CLIMATE... AS OF 315 PM EDT TUESDAY... THIS WAS THE 3RD DRIEST JUNE ON RECORD AT DANVILLE WITH ONLY 1.23 INCHES OF PRECIPITATION. RECORDS GO BACK TO 1948. THE DRIEST JUNE ON RECORD IS 1.06 INCHES IN 2008. && .EQUIPMENT... AS OF 315 PM EDT TUESDAY... COMMUNICATIONS OUTAGE CONTINUES WITH KDAN ASOS NOT TRANSMITTING. THE FAA IS AWARE OF THE OUTAGE AND WILL BE WORKING ON IT...BUT NO ESTIMATED TIME OF WHEN IT WILL BE WORKING AGAIN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...WERT LONG TERM...AMS/WERT AVIATION...AMS/JH CLIMATE...AMS/PC EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
146 PM EDT TUE JUL 8 2014 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY BEFORE SPILLING SLOWLY SOUTHEAST INTO THE AREA ON WEDNESDAY. THIS COMBINED WITH DAYTIME HEATING AND INCREASING MOISTURE...WILL BRING AN INCREASING THREAT FOR SHOWERS AND THUNDERSTORMS...FIRST IN THE FAR WEST LATER TODAY...AND THEN FOR MUCH OF THE AREA BY WEDNESDAY. THE FRONT WILL STRUGGLE TO CLEAR THE PIEDMONT AREAS ON THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1020 AM EDT TUESDAY... HEAT AND HUMIDITY THIS AFTERNOON AS LOW LEVEL SW FLOW ENHANCES AHEAD OF THE APPROACHING UPSTREAM COLD FRONT THIS AFTERNOON. THIS COMBINED WITH DECENT HEATING ESPCLY EARLY ON AND 85H TEMPS AROUND +21C OUT EAST SHOULD AGAIN PUSH HIGHS INTO THE LOW/MID 90S EAST...AND 80S TO PERHAPS CLOSE TO 90 IN SPOTS NEAR THE BLUE RIDGE. HOWEVER STILL WELL BELOW ANY ADVISORY HEADLINES WITH DEWPOINTS AGAIN MIXING LOWER UNDER THE GUSTY SW BREEZE LATER ON. OTRW MAIN CONCERN REMAINS WITH CONVECTIVE COVERAGE ESPCLY VERY LATE THIS AFTERNOON OVER THE FAR WEST AS MODELS SUGGEST AT LEAST A BROKEN LINE OF STORMS WELL IN ADVANCE OF THE BOUNDARY DROPPING SE INTO THE AREA. THIS LOOKS TO AFFECT MAINLY THE SE WVA COUNTIES DOWN TO JUST WEST OF I-77 AFTER 20-22Z/4-6PM OR SO...WITH QUESTIONS TO JUST HOW FAR EAST OR SE THESE STORMS MAY GO GIVEN BEST SUPPORT TO THE NORTH WITH THE UPPER TROF...AND WINDS BACKING TO THE WEST. IF STORMS REDEVELOP ENOUGH TO HAVE AN ORGANIZED COOL POOL...THERE IS JUST ENOUGH INSTABILITY TO BRING SOME OF THIS COVERAGE EAST TO THE BLUE RIDGE AND PERHAPS EAST OF THE MOUNTAINS IN A WEAKENED STATE MAINLY AFTER SUNSET. THIS SUPPORTED MORESO BY THE LATEST NAM/CMC AND SPC WRF AND LESS BY THE GFS WITH THE ECMWF IN BETWEEN. INCREASING UNIDIRECTIONAL FLOW ALOFT AND HIGH FORECAST DCAPES WOULD SUPPORT MORE OF A WIND THREAT AND SEEN VIA THE CURRENT SWODY1. THUS BUMPED UP LIKELY POPS A BIT MORE WESTERN THIRD AND ADDED GUSTY WIND MENTION...WITH A SHARP CUTOFF TO SLIGHT POPS OR LESS OUT EAST THIS AFTERNOON. ANYTHING AHEAD OF THIS LINE WOULD FEATURE MOSTLY ISOLATED THUNDERSTORMS. FRONT WILL STILL BE WEST OF THE MOUNTAINS OVERNIGHT AS A WEAK WAVE HANGS IT UP AND HELPS FOCUS BEST CONVERGENCE ACROSS THE SW CWA UNDER DEEPENING WESTERLY FLOW. THIS SHOULD PIN THE NEXT ROUND OF HIGHER POPS ACROSS THE MTN EMPIRE AREA INTO NW NC OVERNIGHT WITH AGAIN A QUICK DROPOFF IN COVERAGE HEADING EAST PER DOWNSLOPE LIMITING SHRA EAST OF THE BLUE RIDGE AFTER MIDNIGHT. OTRW MOSTLY CLOUDY WEST TO PC ELSW BUT MUGGY WITH LOWS MOSTLY MID 60S VALLEYS TO LOW/MID 70S EAST. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 310 AM EDT TUESDAY... A BROAD UPPER LEVEL TROUGH WILL ENCOMPASS THE NORTHEAST QUARTER OF THE UNITED STATES...FROM THE NORTH AND CENTRAL PLAINS TO THE CAROLINAS AND MID ATLANTIC REGION...WEDNESDAY AND THURSDAY. A SURFACE FRONT WILL SLIDE ACROSS THE FORECAST AREA WEDNESDAY...STALLING ACROSS THE CAROLINAS WEDNESDAY NIGHT. THIS FRONT WILL BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE AREA WEDNESDAY. 00Z MODEL SOLUTIONS FOR WEDNESDAY ARE QUITE DIFFERENT FROM 24 HOURS AGO. LATEST SOLUTIONS LIMITING STRONG STORMS WITH MORE MORNING RAIN AND CLOUDS OVER THE AREA. BULK OF THE STRONGER DYNAMICS AND STORMS APPEARS TO BE MOVING SOUTH INTO THE TENNESSEE VALLEY. THE FRONT BUCKLES TO THE NORTHWEST ON THURSDAY AS A WEAK REFLECTION TRACKS ALONG THE STALLED BOUNDARY ACROSS THE CAROLINAS. IF THIS BOUNDARY DOES BUCKLE...AREAS EAST OF THE BLUE RIDGE...PARTICULARLY SOUTHSIDE...WILL SEE ANOTHER ROUND OF PASSING SHOWERS AND THUNDERSTORMS THURSDAY AFTERNOON AND NIGHT. MORNING CLOUDS AND RAIN SHOULD KEEP MOUNTAIN TEMPERATURES NEAR NORMAL...WHILE THE PIEDMONT SEES WARMER THAN NORMAL TEMPERATURES WEDNESDAY. WITH MOST AREAS RESIDING BEHIND THE FRONT ON THURSDAY...TEMPERATURES WILL RUN COOLER THAN NORMAL. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 300 PM EDT MONDAY... UPPER PATTERN IS AGAIN BECOMING ZONAL THURSDAY NIGHT AND FRIDAY BUT MODELS WERE BRINGING A SHORT WAVE THROUGH THE BASE OF THE EASTERN TROF AND ACROSS THE MID ATLANTIC REGION THURSDAY NIGHT. THE 500 MB TROF DEEPENS AGAIN ON SUNDAY AND MONDAY. SURFACE FRONT IS WELL TO THE SOUTHEAST OF THE FORECAST AREA THURSDAY NIGHT AND FRIDAY BUT ANY WAVE ALONG THE FRONT MAY BRING DEEPER MOISTURE AND A HIGHER PROBABILITY OF PRECIPITATION BACK TOWARD THE SOUTHERN COUNTY WARNING AREA. FORECAST AREA WILL RETURN TO WARM...HUMID...UNSTABLE AIR...AND THE ASSOCIATED CHANCE OF THUNDERSTORMS...SUNDAY AND MONDAY AHEAD OF THE NEXT COLD FRONT. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 145 PM EDT TUESDAY... COMMS ISSUES REMAIN AT KDAN DESPITE AN INTERMITTENT RETURN OF OBSERVATION DATA. AMD NOT SKED CONTINUED IN THE TAF. BAND OF SHOWERS AND THUNDERSTORMS WILL FORM FROM WESTERN PENNSYLVANIA TO EASTERN KENTUCKY AND MOVE EAST DURING THE EVENING. LAST FEW RUNS OF THE HRRR...AS WELL AS THE RUC AND LOCAL WRF HAVE THE STORMS REACHING KBLF AND KBLF FROM 20-21Z/4-5PM. LOWER CONFIDENCE AS TO HOW FAR EAST SHOWERS AND THUNDERSTORMS WILL PROGRESS. HAVE LEFT VCNTY THUNDER IN THE KBCB...KROA AND KLYH TAFS. THE LEAST LIKELY LOCATION TO GET STORMS WILL BE AT KDAN AS LONG AS SCATTERED TO ISOLATED THUNDERSTORMS DO NOT DEVELOP IN THE FOOTHILLS OF THE BLUE RIDE. AS LOWER DEW POINTS MIX DOWN TO THE SURFACE THIS AFTERNOON...THE INSTABILITY WAS BECOMING LESS FAVORABLE FOR THUNDERSTORMS IN THE LEE-TROF. LOSS OF HEATING AND WESTERLY DOWNSLOPE WIND WILL WEAKEN SHOWERS AND THUNDERSTORMS BY 02Z/10PM. MODELS SHOWED LINGERING SHOWERS FROM SOUTHERN WEST VIRGINIA TO EASTERN TENNESSEE OVERNIGHT. DO NOT HAVE ANY IMPACT FROM THIS POTENTIAL RAINFALL IN THE TAFS BUT HAVE ADDED MVFR CEILINGS TO KBLF AFTER MIDNIGHT. ALSO ADDED LIFR FOG AND CEILINGS IN FOR KLWB OVERNIGHT..EXPECTING THERE WILL BE RAIN AT THAT AIRPORT LATE THIS AFTERNOON. EXTENDED AVIATION... BEST CHANCE FOR THUNDERSTORMS ON WEDNESDAY WILL BE IN THE AFTERNOON IN CENTRAL AND EASTERN VIRGINIA AND NORTH CAROLINA WHERE THE INSTABILITY WILL COMBINE WITH OUTFLOW FROM PREVIOUS STORMS. THE COLD FRONT WILL FINALLY PUSH THROUGH THE REGION ON WEDNESDAY NIGHT. THE FRONT WILL LINGER ACROSS SOUTHERN/EASTERN AREAS THROUGH THE END OF THE WEEK WITH IMPULSES RIDING ALONG IT. THIS WILL KEEP UNSETTLED CONDITIONS AT TAF SITES THROUGH THE END OF THE WEEK. EXPECT DIURNAL TRENDS FOR AFTERNOON CONVECTIVE PRECIPITATION WITH ASSOCIATED MVFR OR LOWER CONDITIONS... ESPECIALLY FOR KDAN/KLYH...AND POSSIBLE IFR FOG LATE NIGHTS...MAINLY KBCB AND KLWB. && .EQUIPMENT... COMMS ISSUES WITH KDAN ASOS NOT TRANSMITTING. THE FAA IS AWARE OF THE OUTAGE AND WILL BE WORKING ON IT...BUT NO ESTIMATED TIME OF WHEN IT WILL BE WORKING AGAIN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/SK NEAR TERM...AMS/JH SHORT TERM...RCS LONG TERM...AMS AVIATION...AMS/JH EQUIPMENT...WP