Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/22/14


AREA FORECAST DISCUSSION
NWS TUCSON AZ
150 PM MST SUN JUL 20 2014 .SYNOPSIS...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS MOSTLY EAST AND SOUTH OF TUCSON THROUGH THE MIDDLE OF THE UPCOMING WEEK. MUCH HOTTER TEMPERATURES WILL OCCUR TUESDAY THROUGH THURSDAY...WITH NEAR RECORD HIGHS POSSIBLE. AN INCREASE IN THUNDERSTORM ACTIVITY SHOULD OCCUR LATE IN THE WEEK AND INTO THE WEEKEND. && .DISCUSSION...WATER VAPOR IMAGERY AND 20/12Z UPPER-AIR PLOTS SHOW AN UPPER LOW OVER SOUTH CENTRAL CALIFORNIA AND INTO CENTRAL NEVADA AND MOVING NORTH. MEANWHILE...A RIDGE IS PARKED OVER THE GENERAL VICINITY OF NEW MEXICO AND WEST TEXAS. THIS HAS RESULTED IN A STRONG SOUTHERLY FLOW ALOFT IN THE MID TO UPPER LEVELS...WITH STEERING FLOW AROUND 15 KNOTS. THIS MORNINGS KTWC SOUNDING HAD THE LOWEST/DRIEST PRECIPITABLE WATER VALUE THAT WE HAVE SEEN IN A WHILE...ESPECIALLY FOR A MORNING SOUNDING WITH A VALUE OF 1.04 INCHES. CLIMATOLOGICALLY THIS PW VALUE FALLS IN THE 25TH PERCENTILE FOR THIS TIME OF YEAR...WHICH IS PRETTY DRY...RELATIVELY SPEAKING. THAT SAID...ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOP AS EXPECTED OVER THE HIGHER TERRAIN OF NORTHEAST SONORA AND NORTHWEST CHIHUAHUA. A FEW CELLS COULD MOVE INTO SOUTHERN PORTIONS OF COCHISE COUNTY AND PERHAPS PARTS OF SANTA CRUZ COUNTY AS WELL. U OF A 12Z WRF/NAM MODEL AND HRRR SHOW A SIMILAR SCENARIO. THAT SAID...THINK THE POP FORECAST FOR THE REMAINDER OF THIS AFTERNOON AND INTO THE EVENING SEEM TO BE ON TRACK. HOWEVER...WILL BASE MY FORECAST FOR THIS EVENING LARGELY ON SATELLITE AND RADAR TRENDS RIGHT BEFORE ISSUANCE TIME. THE HIGH IS PROGGED TO MEANDER ACROSS THE GENERAL VICINITY THROUGH MIDWEEK WITH A SIMILAR THREAT FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY OVER THE MOUNTAINS...AS WELL AS ALONG THE INTERNATIONAL BORDER EACH AFTERNOON AND EVENING. FROM WEDNESDAY AND BEYOND I DID NOT MAKE ANY ADJUSTMENTS TO THE INHERITED POP FORECAST DUE TO CONTINUED UNCERTAINTIES THIS TIME OF YEAR. I INHERITED AN UPSWING IN THUNDERSTORM ACTIVITY FRIDAY...ESPECIALLY ALONG THE INTERNATIONAL BORDER NEAR NOGALES AND DOUGLAS. HOWEVER...CONFIDENCE ON THIS HAPPENING IS NOT AS HIGH SINCE THE LATEST MODEL RUNS SHOW THE RIDGE BUILDING WEDNESDAY AND NEARLY OVERHEAD FOR THURSDAY AND FRIDAY. PREVIOUS SOLUTIONS WERE SUGGESTING AN INVERTED TROUGH MOVING WESTWARD ACROSS NORTHERN MEXICO...BUT NOW THIS FEATURE IS LESS PRONOUNCED AND FARTHER SOUTH. THAT SAID...THE RAIN CHANCES FOR FRIDAY MAY BE TOO HIGH. OVERNIGHT SHIFT WILL WANT TO TAKE A CLOSER LOOK AT THIS AFTER RECEIPT OF 00Z MODEL RUNS. THE BIG STORY HOWEVER IS THE EXPECTED HOT TEMPERATURES DURING THE MIDDLE TO LATTER PART OF THE WEEK. HIGHS FOR TUCSON EXPECTED TO POTENTIALLY REACH THE 110 DEG MARK...WITH SLIGHTLY HIGHER READINGS FOR THE FAR WESTERN DESERTS. HIGH TEMPERATURES WILL BE ABOVE NORMAL THROUGHOUT THE ENTIRE FORECAST PERIOD...WITH THE WARMEST DAYS OCCURRING WEDNESDAY AND THURSDAY WHEN HIGHS WILL BE 10 TO 12 DEGS ABOVE NORMAL...OTHERWISE HIGHS RUNNING ABOUT 4 TO 7 DEGS ABOVE NORMAL EACH DAY. LOWS GENERALLY 3 TO 5 DEGS ABOVE NORMAL EACH MORNING. && .CLIMATE...NEAR RECORD HEAT EXPECTED TUESDAY THROUGH THURSDAY. THE FORECAST EXCEEDS RECORD LEVELS ON WEDNESDAY AND THURSDAY WITH TEMPERATURES AROUND 110 AT TUCSON INTERNATIONAL. THIS WOULD BE THE FIRST 110 TEMPS OF THE YEAR AND HOTTEST JULY TEMPS SINCE 2011 (110 OR GREATER OCCURRENCES ARE MOST COMMON IN JUNE BEFORE THE MONSOON ARRIVES). && .AVIATION...ISOLD TO SCT -TSRA WILL OCCUR MOSTLY EAST AND SOUTH OF KTUS THIS AFTERNOON AND EVENING. THE BEST CHANCES WILL OCCUR ACROSS THE WHITE MOUNTAINS NE OF KSAD...AND SE OF KTUS ESPECIALLY IN THE VICINITY OF THE KOLS/KDUG TERMINALS. BRIEF MVFR VISIBILITIES AND WIND GUSTS TO 40 KTS MAY OCCUR WITH -TSRA. OTHERWISE SFC WINDS WILL BE LESS THAN 10 KTS EXCEPT FOR THE GILA RIVER VALLEY IN THE VICINITY OF KSAD...WHERE WLY/NWLY SURFACE WIND AROUND 15 KTS THRU EARLY EVENING. THE -TSRA AND WIND FORECAST FOR MONDAY IS SIMILAR TO THAT OF TODAY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...THUNDERSTORMS REMAIN IN THE FORECAST NEAR THE INTERNATIONAL BORDER AND IN THE EASTERN MOUNTAINS ALONG THE NEW MEXICO BORDER EARLY THIS WEEK...BUT STRENGTHENING HIGH PRESSURE ALOFT WILL TEND TO LIMIT OVERALL THUNDERSTORM COVERAGE AND BRING NEAR RECORD HIGH TEMPERATURES BY THE MIDDLE OF THE WORK WEEK. INCREASED MOISTURE AND BETTER CHANCES FOR THUNDERSTORMS ARE FORESEEN AS THE WEEK DRAWS TO A CLOSE. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON PUBLIC...MOLLERE AVIATION/FIRE WEATHER...KD
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1030 PM MST SAT JUL 19 2014 .UPDATE...UPDATED AVIATION DISCUSSION. && .SYNOPSIS... STRONG HIGH PRESSURE WILL BUILD ACROSS THE REGION BEGINNING SUNDAY...RESULTING IN DRIER CONDITIONS AND A STEADY WARMING TREND. THE HOTTEST TEMPERATURES OF THE SUMMER ARE EXPECTED WEDNESDAY AND THURSDAY WITH READINGS IN THE LOWER DESERTS EXCEEDING 110 DEGREES. THUNDERSTORMS WILL GENERALLY REMAIN RELEGATED TO THE HIGHER TERRAIN OF EASTERN ARIZONA THROUGH THE MIDDLE OF THE WEEK. && .DISCUSSION... THE SHORTWAVE...THAT BROUGHT CONSIDERABLE CLOUDINESS AND EVEN A FEW SPRINKLES/SHOWERS TO THE REGION THIS MORNING...HAS NOW MOVED WELL TO OUR NORTH AND WEST...INTO SOUTHERN NV AND SOUTH-CENTRAL CA. BEHIND THIS SHORTWAVE...DRIER AIR HAS BEEN PULLED NORTHWARD INTO THE REGION...WITH SFC DEWPOINTS FALLING BACK DOWN INTO THE 30S AND 40S AT MOST LOWER DESERT LOCATIONS THIS AFTERNOON. THE COMBINATION OF THIS LOW-LEVEL DRYING ALONG WITH A SWITCH IN THE UPPER AIR FLOW TO A MORE SOUTHWESTERLY ONE HAS ENDED THE CONVECTIVE ACTIVITY OVER OUR CWA THIS EVENING...AND HAS ALSO CLEARED SKIES OUT AT MANY LOCATIONS. THIS QUIET WEATHER REGIME IS EXPECTED TO LAST THROUGH SUNDAY...AND BEYOND AS THE ATMOSPHERE CONTINUES TO DRY OUR FURTHER...WITH THE 18Z GFS SHOWING PWATS FALLING WELL BELOW 1 INCH BY SUNDAY NIGHT. THUS...OTHER THAN SOME MINOR ADJUSTMENTS TO TEMPERATURE AND DEWPOINT TRENDS...CURRENT GRIDDED AND ZONE FORECASTS ARE HOLDING UP WELL...AND NO UPDATES ARE PLANNED. && .PREVIOUS DISCUSSION... TWO DISTINCT VORTICITY CENTERS EMANATING FROM THE SUBTROPICAL EAST PACIFIC CONTINUED TO MOVE NORTH THROUGH THE FORECAST AREA EARLY THIS AFTERNOON. THE INITIAL LEAD SHORTWAVE COINCIDENT WITH STRONG UPPER LEVEL DIFLUENCE ON THE LEADING EDGE OF A SEASONABLY ROBUST MERIDIONAL JET HAS PROPAGATED TO NEAR KSAN...WHILE THE SECONDARY TRAILING FEATURE WAS PUSHING TOWARDS THE NORTHERN GULF OF CALIFORNIA. THE LEADING VORTICITY MAX HAS BEEN ABLE TO TAP ENOUGH MOISTURE IN THE STEEPER LAPSE RATE 600-400MB LAYER COMBINING WITH FORCED ASCENT TO KEEP LINES OF SHOWERS PERCOLATING THROUGH PARTS OF WRN ARIZONA/SERN CALIFORNIA. HOWEVER...A SUBSTANTIAL SYNOPTIC SCALE DRYSLOT HAS DEVELOPED IN THE WAKE OF THIS LEAD WAVE...SUCH THAT SUBSIDENCE WAS OVERWHELMING ANY INFLUENCE FROM THE SECONDARY WAVE. WHILE A FEW ISOLD SHRA/TSRA MAY MATERIALIZE WITH THIS TRIALING WAVE...THE BETTER PERFORMING RECENT HRRR OUTPUT SUGGESTS LITTLE ADDITIONAL ACTIVITY WITHIN THE FORECAST AREA THROUGH THIS EVENING. A DRIER SOUTHWESTERLY FLOW WILL DEVELOP SUNDAY BETWEEN THE MONSOON HIGH ACROSS NM AND AN UPPER LOW OFF THE CA COAST. SLIGHTLY ABOVE NORMAL TEMPERATURES ARE EXPECTED SUNDAY AND MONDAY...WITH A STEADY WARMING TREND THROUGH MIDWEEK IN RESPONSE TO HIGH PRESSURE ALOFT CENTERED NEAR THE FOUR CORNERS INTENSIFYING TO OVER 600 DAM. WITH VERY LOW SPREAD BETWEEN MODELS AND ENSEMBLE MEMBERS WITH RESPECT TO HEIGHT CENTERS AND THERMAL PROFILES...CONFIDENCE IS HIGH THAT TEMPERATURES WILL RANGE A FEW DEGREES ABOVE CLIMATOLOGY AND ISOLATED STORMS REMAINING OVER HIGH TERRAIN OF FAR EASTERN ARIZONA (AND THE MORE ORGANIZED CONVECTION WELL TO THE SOUTH IN SONORA AND CHIHUAHUA). THE AFOREMENTIONED HIGH PRESSURE SYSTEM WILL GRADUALLY EXPAND AND SHIFT WESTWARD DURING THE LATTER HALF OF THE WEEK...PORTENDING ADDITIONAL WARMING AND THE HOTTEST WEATHER OF THE SUMMER THUS FAR. ONE VERY CRITICAL CONCERN IS THE VERY GOOD POTENTIAL FOR DEBRIS CLOUDS AND PRESENCE OF MOISTURE AND OUTFLOWS WILL TEMPER THE HEAT SOMEWHAT. IN PARTICULAR WITH LIGHT E/SE FLOW ALOFT...THE 12Z GFS DEPICTS THICK ANVIL DEBRIS FROM NRN MEXICO SPREADING ACROSS THE CWA TUESDAY...AND HAVE CUT FORECAST HIGHS DESPITE MARKED INCREASES IN TEMPERATURES AND THICKNESSES. FURTHER EXPANSION OF THE HIGHEST HEIGHTS ALOFT WEDNESDAY AND THURSDAY WILL PROBABLY LEAD TO EXCESSIVE HEAT ACROSS PORTIONS OF THE AREA...AND HAVE TAILORED THE FORECAST TOWARDS THE WARMEST AVAILABLE GUIDANCE. MEANWHILE...THUNDERSTORM ACTIVITY IN THE LOWER DESERTS WILL LIKELY BE DORMANT UNTIL AT LEAST NEXT WEEKEND...RELEGATED TO HIGHER TERRAIN OF SRN GILA COUNTY (THOUGH OUTFLOW WINDS AND BLOWING DUST EVENTS CANNOT BE DISCOUNTED). SEVERAL GFS RUNS SUGGESTS THAT A PV DISTURBANCE MAY ROTATE AROUND THE RIDGE TO A FAVORABLE POSITION FOR CONVECTION AND COOLER TEMPERATURES BY NEXT FRIDAY/SATURDAY...WITH THE ECMWF ONLY SOMEWHAT SLOWER IN PUNCHING QUALITY MOISTURE NORTHWARD. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL AND SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA KBLH AND KIPL... DRIER AIR MOVING NORTHWARD INTO THE REGION BEHIND A WEAK WEATHER DISTURBANCE THAT BROUGHT BKN-OVC CIGS...AND EVEN A FEW SHOWERS TO THE TERMINALS EARLIER ON SAT IS EXPECTED TO KEEP THE CLOUD COVERAGE DOWN INTO THE FEW-SCT RANGE THROUGH THE TAF PERIOD. WINDS WILL ONCE AGAIN BE MOSTLY ON THE LIGHT SIDE...AOB 10 KTS...EXCEPT AT KBLH...WHICH WILL LIKELY SEE ANOTHER PERIOD OF GUSTY SOUTHERLY WINDS DURING THE DAY ON SUNDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... DRY AND VERY WARM WEATHER WILL PERSIST THROUGH THE FORECAST PERIOD. AFTERNOON AND EVENING THUNDERSTORMS ARE POSSIBLE BUT CHANCES WILL BE MAINLY CONFINED TO THE HIGHER TERRAIN OF SOUTH-CENTRAL ARIZONA. WEDNESDAY AND THURSDAY WILL SEE HIGH TEMPERATURES IN THE LOWER DESERTS APPROACHING OR EXCEEDING 115 DEGREES. AFTERNOON MINIMUM HUMIDITIES DURING THIS TIME WILL DROP INTO THE LOW TO MID TEENS...THOUGH GOOD OVERNIGHT RECOVERY IS EXPECTED EACH DAY. WINDS WILL BE GENERALLY LIGHT AND FAVOR TYPICAL DIURNAL PATTERNS. SOME OCCASIONAL AFTERNOON AND EVENING GUSTINESS IS POSSIBLE. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA/MO/HIRSCH AVIATION....PERCHA FIRE WEATHER...MCLANE
AREA FORECAST DISCUSSION
NWS TUCSON AZ
905 PM MST SAT JUL 19 2014 .SYNOPSIS...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS MOSTLY EAST AND SOUTH OF TUCSON THROUGH THE MIDDLE OF THE UPCOMING WEEK. MUCH HOTTER TEMPERATURES WILL OCCUR TUESDAY THROUGH THURSDAY...WITH NEAR RECORD HIGHS POSSIBLE. A PRONOUNCED INCREASE IN THUNDERSTORM ACTIVITY SHOULD THEN PREVAIL BY THE END OF THE UPCOMING WEEK. && .DISCUSSION...IR SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATED MOSTLY CLEAR SKIES TO PARTLY CLOUDY SKIES ACROSS MUCH OF SE AZ AT THIS TIME. SOMEWHAT THICKER CLOUDINESS WAS NOTED OVER FAR ERN SECTIONS. DEWPOINTS AT LOWER ELEVATIONS VALID 20/04Z RANGED FROM THE MID 40S-MID 50S F...AND THESE TEMPS WERE GENERALLY 2-6 DEGS F HIGHER VERSUS 24 HOURS AGO. 20/00Z KTWC SOUNDING TOTAL PRECIP WATER VALUE WAS ABOUT 1.10 INCHES...OR NEARLY 0.30 INCH LOWER VERSUS FRI EVENING. AXIS OF COLDER CLOUD TOPS WITH EMBEDDED SHOWERS/TSTMS EXTENDED FROM FAR ERN SONORA/WRN CHIHUAHUA NWD INTO SWRN NEW MEXICO. CONVECTIVE ACTIVITY SHOULD CONTINUE DURING THE NEXT SEVERAL HOURS JUST EAST TO SOUTHEAST OF THIS FORECAST AREA UNDER DIFFLUENT FLOW ALOFT. CANNOT COMPLETELY RULE OUT THE POSSIBILITY OF SHOWER/TSTM DEVELOPMENT ASSOCIATED WITH OUTFLOW THAT MAY ENCROACH UPON FAR SERN SECTIONS LATER TONIGHT. HOWEVER...20/00Z NAM AND 20/01Z RUC HRRR DEPICT DRY CONDITIONS TO OCCUR LATE TONIGHT...AND AM INCLINED TO BELIEVE THESE SOLUTIONS. THUS...HAVE OPTED FOR DRY CONDITIONS AREA-WIDE THE REST OF TONIGHT. EXPECT ISOLATED TO SCATTERED SHOWERS/TSTMS MOSTLY EAST AND SOUTH OF TUCSON SUNDAY AFTERNOON AND SUNDAY EVENING. HIGH TEMPS SUN ARE FORECAST TO BE QUITE SIMILAR TO TEMPS ACHIEVED THIS AFTERNOON. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL. && .AVIATION...VALID THRU 21/06Z. ISOLATED -TSRA/-SHRA NEAR THE FAR SERN AZ/SWRN NEW MEXICO BORDER EAST OF KDUG ENDING AROUND 20/06Z. OTHERWISE...DRY CONDITIONS WILL PREVAIL THE REST OF TONIGHT INTO EARLY SUNDAY MORNING. ISOLATED TO SCATTERED -TSRA/-SHRA WILL THEN OCCUR MOSTLY EAST AND SOUTH OF KTUS SUNDAY AFTERNOON AND SUNDAY EVENING. BRIEF MVFR VISIBILITIES AND WIND GUSTS TO NEAR 35 KTS MAY OCCUR WITH THIS ACTIVITY. CLOUD DECKS INTO SUNDAY EVENING WILL GENERALLY BE AT 8-12K FT AGL. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...ISOLATED TO SCATTERED THUNDERSTORMS WILL OCCUR MOSTLY EAST AND SOUTH OF TUCSON THROUGH THE MIDDLE OF THE UPCOMING WEEK. STRENGTHENING HIGH PRESSURE ALOFT WILL ALSO BRING HOTTER TEMPERATURES TUESDAY THROUGH THURSDAY. THEREAFTER...INCREASED THUNDERSTORM ACTIVITY SHOULD OCCUR DURING THE LATTER PART OF THE UPCOMING WEEK AND INTO NEXT WEEKEND. && .CLIMATE...NEAR RECORD HEAT EXPECTED TUESDAY THROUGH THURSDAY. THE FORECAST EXCEEDS RECORD LEVELS ON WEDNESDAY AND THURSDAY WITH TEMPERATURES AROUND 110 AT TUCSON INTERNATIONAL. THIS WOULD BE THE FIRST 110 TEMPS OF THE YEAR AND HOTTEST JULY TEMPS SINCE 2011 (110 OR GREATER OCCURRENCES ARE MOST COMMON IN JUNE BEFORE THE MONSOON ARRIVES). && .PREV DISCUSSION...SUNDAY DOESN`T LOOK MUCH BETTER AND EVEN STARTS TO PICK UP A BIT OF A SOUTHWESTERLY FLOW IN WESTERN AREAS AS THE RIDGE STARTS TO BUILD IN ERNEST THROUGH WEST TEXAS AND SOUTHERN NEW MEXICO. THE MONSOON WILL PROBABLY SPUTTER WITH BELOW AVERAGE DAYS MUCH OF THE COMING WEEK. STRONG RIDGE BUILDING THROUGH THE DESERT SOUTHWEST AND FRONT RANGE THIS COMING WEEK. COMBINED WITH THE MARGINAL MOISTURE SITUATION EXPECT NEAR RECORD HEAT TUESDAY AND ESPECIALLY WEDNESDAY AND THURSDAY. THICKNESS REGRESSION ANALYSIS AND MODEL H8 TEMPS SCREAMING FOR RECORD VALUES WEDNESDAY AND THURSDAY. THE EVENT IS AN OUTLIER SO WE`RE BETTER SERVED WITH SOLID INDIVIDUAL MODEL ANALYSIS PERFORMANCE OVER CONSENSUS SUITES. RAW DATA FROM BOTH GFS AND ECMWF SEEM TO BE HANDLING THE MID WEEK HEAT PRETTY WELL...WITH MOS DATA A LITTLE LOW DUE CLIMO INFLUENCE. WE WILL GO WITH TEMPERATURES NEAR 110 AT TIA BOTH WEDNESDAY AND THURSDAY AS A BASELINE BUT POTENTIAL IS THERE FOR A COUPLE OF DEGREES HOTTER. THE MAIN FACTOR TO INTERFERE WITH THE RECORD HEAT FORECAST AT THIS POINT WOULD BE MOISTURE...AND AS OF NOW IT ISN`T LOOKING TERRIBLY WET BY AT LEAST WEDNESDAY. SURGE...PROBABLY A STRONG SURGE...WOULD BE A GOOD FIRST GUESS AFTER A COUPLE OF DAYS OF RECORD HEAT AS LONG AS LARGER SCALE FEATURES DON`T INTERFERE. WITH THE RIDGE AXIS ORIENTED EAST-WEST AND POSITIONED NORTH OF OUR AREA WE SHOULD BE FINE FOR OUR PART OF THE STATE. THE ECMWF EVEN SETS UP A STRONG MOISTURE FIELD THROUGH SONORA AND INTO SOUTHEAST ARIZONA BY FRIDAY AND SATURDAY. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON FRANCIS PREV DISCUSSION...MEYER
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1054 AM PDT SUN JUL 20 2014 .SYNOPSIS...MONSOONAL MOISTURE WILL CONTINUE TO PRODUCE ISOLATED LIGHT SHOWERS ACROSS THE REGION TODAY. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS AS WELL. MILD TEMPERATURES WILL CONTINUE THROUGH THE MIDDLE OF NEXT WEEK...WITH A WARMING TREND FORECAST FOR INLAND AREAS DURING THE SECOND HALF OF THE WEEK. && .DISCUSSION...AS OF 8:47 AM PDT SUNDAY...SHORT TERM FOCUS WILL BE ON SHOWERS/SPRINKLES THIS MORNING AND ISOLATED T-STORM POTENTIAL THIS AFTERNOON. KMUX-88D CONTINUES TO SHOW SHOWER ACTIVITY ACROSS THE NORTH BAY BUT SIMILAR TO THE LAST 24 HOURS AND PREVIOUS MONSOON EVENTS ITS ONLY DROPPING TRACE AMOUNTS OF RAIN WITH NUMEROUS REPORTS OF VIRGA. NONETHELESS BRIEF SHOWERS WITH BIG DROPS THAT WILL BE JUST ENOUGH TO WET THE GROUND WILL CONTINUE TO BE MOST LIKELY IN THE NORTH AND EAST BAY THIS MORNING. ON WATER VAPOR THERE IS A VERY WELL DEFINED VORTICITY MAXIMA CURRENTLY ROTATING OVER TULARE COUNTY. THIS FEATURE IN COMBINATION WITH THE HIGH SIERRA HAS PRODUCED NUMEROUS LIGHTNING STRIKES THIS MORNING (NOT THE USUAL AFTERNOON STUFF) OVER THE CREST. THE NAM/HRRR AND RUC SHORT TERM MESOSCALE MODELS HAVE BEEN PRETTY CONSISTENT IN DEVELOPING SOME POSSIBLE T-STORMS BY EARLY THIS AFTERNOON OVER SOUTHEASTERN SAN BENITO AND MONTEREY COUNTIES. ROUGHLY IN THE VICINITY OF SANTA RITA MOUNTAIN/PRIEST VALLEY/PARKFIELD/HWY 198. WILL CONTINUE TO MONITOR THIS REGION FOR POSSIBLE T-STORMS THIS AFTERNOON WITH CLEAR SKIES CURRENTLY OVER THE REGION WHICH SHOULD HELP TO DESTABILIZE THINGS. EVEN THOUGH AIRMASS IS VERY MOIST AND WERE NOT SEEING DRY THUNDERSTORMS ANY LIGHTNING STRIKES OVER THE INTERIOR HILLS REMAIN SUSCEPTIBLE TO NEW FIRE IGNITIONS. OUTSIDE OF THE ISOLATED SPRINKLES...ETC IT SHOULD BE A FAIRLY NICE SUNDAY AFTERNOON FOR MOST LOCATIONS WITH BREAKS IN THE CLOUDS AND COMFORTABLE TEMPERATURES IN THE 70S AND 80S MOST LOCATIONS. LOOKING AHEAD TO THE WORK WEEK...A TROUGH OFF THE COAST SHOULD TURN THE MAIN FLOW BACK TO WSW WHICH WILL PUT AN END TO THE MONSOON THREAT LOCALLY (STILL PLENTY OF AFTERNOON STORMS IN THE SIERRA). NEAR OR EVEN SLIGHTLY BELOW NORMAL TEMPERATURES EARLY IN THE WEEK SHOULD TREND UPWARDS...ESPECIALLY INLAND AS THE DOMINATE HIGH OVER THE ROCKIES/FOUR-CORNERS REGION EXPANDS WESTWARD ONCE AGAIN. && .PREV DISCUSSION...AS OF 3:35 AM PDT SUNDAY...SUBTROPICAL MOISTURE CONTINUES TO STREAM ACROSS CALIFORNIA EARLY THIS MORNING. PRECIPITABLE WATER VALUES ARE AS HIGH AS 1.5 INCHES JUST TO THE SOUTH OF OUR CWA. RADAR SHOWS THAT WIDELY SCATTERED LIGHT SHOWER ACTIVITY IS CURRENTLY TRACKING FROM EAST TO WEST ACROSS MONTEREY AND SAN BENITO COUNTIES. EXPECT ISOLATED SHOWER ACTIVITY TO SPREAD NORTHWARD THROUGH TODAY AS A SHORTWAVE TROUGH CURRENTLY OVER SOUTHERN CA LIFTS TO THE NORTHWEST. LIGHTNING STRIKES WERE DETECTED IN WESTERN FRESNO COUNTY A FEW HOURS AGO AND THE NAM CONTINUES TO SHOW A TREND TOWARDS GREATER INSTABILITY. SO WILL CONTINUE TO FORECAST ISOLATED SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS THROUGH THE DAY TODAY. THUNDERSTORM POTENTIAL LOOKS TO BE GREATEST ACROSS THE SOUTHERN HALF OF OUR FORECAST AREA WHERE THE NAM FORECASTS MU CAPE VALUES IN EXCESS OF 200 J/KG. MOST PRECIPITATION TODAY WILL BE LIGHT AND BRIEF AND SO ONLY ISOLATED MEASURABLE RAINFALL IS EXPECTED. THE BEST POTENTIAL FOR WETTING RAIN IS ACROSS SOUTHEAST SAN BENITO COUNTY WHERE THE NAM FORECASTS MORE THAN A QUARTER OF AN INCH OF RAIN. SUBTROPICAL MOISTURE WILL LIFT VERY SLOWLY NORTH THROUGH TONIGHT. RECENT MODEL OUTPUT SUGGEST ONLY GRADUAL SOUTH-TO-NORTH CLEARING OF MID AND HIGH LEVEL CLOUDS TONIGHT. IN FACT...IT NOW LOOKS LIKE MOISTURE MAY BE HUNG UP ACROSS THE NORTH BAY THROUGH AT LEAST MONDAY MORNING AS A DEFORMATION ZONE DEVELOPS BETWEEN SOUTHERLY FLOW ACROSS CENTRAL AND SOUTHERN CA AND AN UPPER TROUGH DROPPING SOUTH OFF THE COAST OF THE PAC NW. IT`S UNLIKELY THERE WILL BE MUCH PRECIP AFTER TODAY...BUT HAVE GONE AHEAD AND MAINTAINED A SLIGHT CHANCE OF SHOWERS ACROSS THE NORTH BAY THROUGH THIS EVENING GIVEN RECENT MODEL TRENDS. MOST SUBTROPICAL MOISTURE WILL EXIT OUR AREA BY LATE MONDAY AS THE FLOW ALOFT TURNS TO THE SOUTHWEST. BUT THEN...THE MODELS BRING ONE MORE BRIEF SHOT OF SUBTROPICAL MOISTURE ACROSS OUR AREA FROM THE SSW ON MONDAY NIGHT AS A TROUGH OFF THE COAST OF SOUTHERN CA LIFTS TO THE NE. IT`S DOUBTFUL WE WILL SEE MORE THAN SOME PASSING MID AND HIGH LEVEL CLOUDS WITH THIS...BUT WILL NEED TO MONITOR FOR THE POTENTIAL FOR ADDITIONAL ISOLATED SHOWERS/THUNDERSTORMS ON MONDAY NIGHT. INCREASED MID/HIGH LEVEL CLOUD COVER TODAY WILL MEAN SLIGHTLY COOLER TEMPERATURES COMPARED TO YESTERDAY. COOLER THAN NORMAL INLAND TEMPS WILL THEN CONTINUE INTO MONDAY AND TUESDAY AS THE UPPER LOW OFF THE SOUTHERN CA COAST LIFTS NORTHEAST...BRINGING IN A SLIGHTLY COOLER AIRMASS AND ENHANCING ONSHORE FLOW. HOWEVER...COASTAL AREAS WILL CONTINUE TO SEE NEAR NORMAL OR EVEN SLIGHTLY ABOVE NORMAL TEMPERATURES DUE TO WARMER THAN AVERAGE SEA SURFACE TEMPS WHICH ARE A BYPRODUCT OF A RECENT LACK OF NORTHWESTERLY FLOW ALONG THE COAST AND THUS A REDUCTION IN UPWELLING. THE MODELS HAVE BEEN CONSISTENT IN BUILDING AN UPPER RIDGE ACROSS CA FROM THE EAST DURING THE SECOND HALF OF THE WEEK. THIS WILL MEAN WARMER TEMPS ACROSS OUR AREA FROM THURSDAY INTO NEXT WEEKEND. MOST WARMING WILL OCCUR ACROSS INLAND AREAS WHERE HIGHS WILL CLIMB INTO THE 90S IN THE WARMEST SF BAY AREA VALLEYS AND BACK OVER 100 IN INTERIOR MONTEREY AND SAN BENITO COUNTIES. PERSISTENT ONSHORE FLOW AND A SHALLOW MARINE LAYER WILL KEEP COASTAL AREAS FROM WARMING MORE THAN A FEW DEGREES. && .AVIATION...AS OF 10:45 AM PDT SUNDAY...VFR CONDITIONS EXPECTED THROUGH MUCH OF THE AFTERNOON AND EARLY EVENING HOURS WITH CONTINUED HIGH CLOUDS STREAMING ACROSS THE REGION. ISOLATED SHOWERS REMAIN POSSIBLE THROUGH THE DAY WITH A POSSIBLE THUNDERSTORM OR TWO THIS AFTERNOON...GENERALLY LOW CONFIDENCE FOR THUNDERSTORMS. LOWERING CIGS EXPECTED LATE TONIGHT INTO EARLY MONDAY MORNING. VICINITY OF KSFO...VFR CONDITIONS WITH WESTERLY WINDS INCREASING TO 10 TO 15 KT THIS AFTERNOON WITH GUSTS TO 22 KT. VICINITY SHOWERS POSSIBLE THROUGHOUT THE DAY...YET LITTLE IMPACT EXPECTED. POSSIBLE RETURN OF MVFR/IFR CIGS EARLY MONDAY MORNING. LOW CONFIDENCE ON STRATUS RETURN OVER TERMINAL. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. HIGHER CONFIDENCE ON STRATUS RETURN OVER APPROACH MONDAY MORNING. MONTEREY BAY AREA TERMINALS...VFR CONDITIONS WITH VICINITY SHOWERS POSSIBLE LATER THIS AFTERNOON AND EVENING. MVFR/IFR CIGS RETURN LATE TONIGHT AND CONTINUE THROUGH MONDAY MORNING. MODERATE CONFIDENCE. && .FIRE WEATHER....AS OF 4:30 AM PDT SUNDAY...WIDELY SCATTERED LIGHT SHOWERS ARE FORECAST ACROSS THE DISTRICT TODAY. A FEW ISOLATED LIGHTNING STRIKES ARE POSSIBLE...ESPECIALLY ACROSS THE SOUTH. HOWEVER...LIGHTNING IS UNLIKELY GIVEN THAT ONLY MARGINALLY UNSTABLE CONDITIONS WILL EXIST. ALSO...IF LIGHTNING DOES OCCUR IT WILL LIKELY BE ACCOMPANIED BY RAINFALL. MONSOONAL MOISTURE WILL GRADUALLY MOVE NORTH AND OUT OF THE AREA BY MIDDAY MONDAY. TEMPERATURES WILL REMAIN NEAR SEASONABLE NORMS THROUGH MIDWEEK AS LIGHT ONSHORE FLOW CONTINUES. HIGH PRESSURE WILL STRENGTHEN ACROSS CALIFORNIA DURING THE SECOND HALF OF THE WEEK...RESULTING IN WARMER AND DRIER WEATHER STARTING ON THURSDAY...ESPECIALLY FOR INLAND AREAS. && .MARINE...AS OF 10:45 AM PDT SUNDAY...A WEAK SURFACE PRESSURE GRADIENT ACROSS THE COASTAL WATERS WILL MAINTAIN LIGHT WINDS AND GENTLE SEAS THROUGH EARLY NEXT WEEK. NORTHWESTERLY WINDS WILL INCREASE BY MIDWEEK AS A THERMAL TROUGH DEVELOPS OVER INTERIOR CALIFORNIA. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 11 AM && $$ PUBLIC FORECAST: RWW AVIATION/MARINE: RGASS VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
1025 AM PDT SUN JUL 20 2014 ...UPDATED AVIATION DISCUSSION... .SYNOPSIS... SCATTERED SHOWERS AND SPRINKLES AND ISOLATED THUNDERSTORMS IN THE MOUNTAINS ARE EXPECTED TO DIMINISH THIS EVENING. WEAK UPPER LEVEL LOW PRESSURE OFF THE COAST AND ONSHORE FLOW WILL KEEP DAYTIME TEMPERATURES BELOW NORMAL THROUGH EARLY IN THE WEEK. HIGH PRESSURE WILL THEN BRING A WARMING TREND THROUGH THE END OF THE WEEK...WITH ABOVE NORMAL TEMPERATURES EXPECTED FOR INTERIOR SECTIONS. && .SHORT TERM (TODAY-TUE)...THE LAST OF THIS LATEST LITTLE SUBTROPICAL SURGE IS MOVING THROUGH THIS MORNING WITH A FEW SPRINKLES AROUND, MAINLY FOR SLO AND NRN SBA COUNTY. A SURPRISINGLY DEEP AND SOLID MARINE LYR HAS FORMED IN IT`S WAKE ACROSS LA COUNTY WITH TOPS AROUND 3500`. BY AFTERNOON SKIES SHOULD BECOME PARTLY CLOUDY EVERYWHERE WITH HIGHS STILL A FEW DEGREES BELOW NORMAL. MODELS INDICATING SOME INSTABILITY ACROSS THE INTERIOR THIS AFTERNOON AND CAN`T ARGUE WITH SLIGHT CHANCES OF THUNDERSTORMS THERE, THOUGH HRRR MODEL SHOWS VIRTUALLY NOTHING DEVELOPING ONCE THIS BAND OF SPRINKLES MOVES THROUGH LATER THIS MORNING. NAM12 CAPE IS FAIRLY IMPRESSIVE THOUGH AT GREATER THAN 1200 J/KG ACROSS VENTURA COUNTY AND JUST SLIGHTLY LESS ACROSS THE SAN GABRIELS. ***FROM PREVIOUS DISCUSSION*** ANY SHOWER/TSTM ACTIVITY SHOULD END BY MID OR LATE EVENING...THEN SKIES WILL BECOME MOSTLY CLEAR. THE WRF INDICATES A FAIRLY SOLID STRATUS PATTERN IN COASTAL AND MOST VALLEY AREAS BY LATE TONIGHT...WHICH SEEMS REASONABLY AS MID LEVEL MOISTURE DECREASES. LOW CLOUDS SHOULD CLEAR BY LATE MORNING MON IN MOST AREAS. SMALL RISES IN HEIGHTS AND THICKNESSES MAY BRING A COUPLE OF DEGREES OF WARMING TO INTERIOR SECTIONS ON MONDAY...BUT MAX TEMPS STILL WILL BE BELOW NORMAL. AN UPPER HIGH OVER THE S CENTRAL U.S. WILL BEGIN TO EXPAND WESTWARD TOWARD THE AREA MON NIGHT AND TUE...AS A WEAK UPPER LOW WELL OFF THE COAST OPENS UP AND LIFT NEWD TOWARD CENTRAL AND NRN CA. HEIGHTS AND THICKNESSES WILL RISE ACROSS THE REGION TUE. THE MARINE LAYER WILL LIKELY SHRINK IN DEPTH...BUT NIGHT/MORNING LOW CLOUDS AND FOG WILL PROBABLY STILL PUSH INTO COASTAL AND AT LEAST THE LOWER VLY LOCATIONS. MAX TEMPS WILL BE UP A FEW DEGREES ON TUESDAY... ESPECIALLY IN THE VLYS...MTNS AND DESERTS...BUT SHOULD STILL BE A BIT BELOW NORMAL. .LONG TERM (WED-SAT)...THE UPPER HIGH WILL CONTINUE TO EXPAND INTO THE REGION FROM THE EAST WED AND THU...AND HEIGHTS/THICKNESSES WILL CONT TO RISE. NIGHT THROUGH MORNING STRATUS WILL BECOME CONFINED TO THE COASTAL PLAIN. THERE WILL BE WARMING BOTH WED AND THU...WITH TEMPS RISING TO ABOVE NORMAL LEVELS IN MOST AREAS. MAX TEMPS SHOULD REACH 100 DEGREES IN THE ANTELOPE VALLEY ON WED...AND IN THE WARMER VALLEY LOCATIONS WEST OF THE MTNS BY THU. EXPECT LITTLE CHANGE FOR FRI AND SAT AS THE UPPER HIGH REMAINS LOCKED IN PLACE NEAR THE FOUR CORNERS REGION. THE UPPER PATTERN WILL BECOME MORE FAVORABLE TO SEND SOME MONSOONAL MOISTURE INTO THE REGION BY SAT...BUT FOR NOW...MODELS KEEP MOST OF THE MOISTURE TO THE E OF THE AREA. && .AVIATION...20/1725Z... LATEST AMDAR SOUNDINGS INDICATE RATHER WEAK INVERSION BASED AROUND 3000 FEET. COASTAL/VALLEY TAFS ALL CURRENTLY HAVE MVFR/VFR CIGS WHICH ARE EXPECTED TO DISSIPATE THIS AFTERNOON. FOR TONIGHT...HIGH CONFIDENCE IN RETURN OF MVFR/IFR CIGS TO ALL COASTAL/VALLEY TAF SITES...BUT LOW CONFIDENCE IN TIMING OF STRATUS RETURN. KLAX...MODERATE CONFIDENCE IN 18Z TAF. HIGH CONFIDENCE IN MVFR CIGS SCATTERING OUT AROUND 20Z. HIGH CONFIDENCE IN RETURN OF MVFR CIGS TONIGHT...ALTHOUGH CONFIDENCE IN TIMING OF STRATUS RETURN IS LOW. RETURN OF MVFR CIGS COULD BE +/- 3 HOURS OF CURRENT 05Z FORECAST. KBUR...MODERATE CONFIDENCE IN 18Z TAF. HIGH CONFIDENCE IN MVFR CIGS DISSIPATING BY 20Z. HIGH CONFIDENCE IN RETURN OF MVFR CIGS TONIGHT ALTHOUGH LOW CONFIDENCE IN TIMING OF STRATUS RETURN. MVFR CIGS COULD RETURN +/- 3 HOURS OF CURRENT 08Z FORECAST. && .MARINE...20/900 AM NO SIGNIFICANT MARINE ISSUES ARE EXPECTED THROUGH MONDAY. ON TUESDAY WINDS ACROSS THE OUTER WATERS WILL BEGIN TO INCREASE...POSSIBLY APPROACHING ADVISORY LEVELS. MODERATE CONFIDENCE IN GUSTY NORTHWEST WINDS CONTINUING ACROSS THE OUTER WATERS WEDNESDAY THROUGH THURSDAY WITH NEAR GALE FORCE GUSTS POSSIBLE AROUND POINT CONCEPTION. && .LOX WATCHES/WARNINGS/ADVISORIES... NONE && $$ PUBLIC...MW/DB AVIATION...RAT MARINE...RAT SYNOPSIS...SWEET WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
925 AM PDT SUN JUL 20 2014 .SYNOPSIS... SCATTERED SHOWERS AND SPRINKLES AND ISOLATED THUNDERSTORMS IN THE MOUNTAINS ARE EXPECTED TO DIMINISH THIS EVENING. WEAK UPPER LEVEL LOW PRESSURE OFF THE COAST AND ONSHORE FLOW WILL KEEP DAYTIME TEMPERATURES BELOW NORMAL THROUGH EARLY IN THE WEEK. HIGH PRESSURE WILL THEN BRING A WARMING TREND THROUGH THE END OF THE WEEK...WITH ABOVE NORMAL TEMPERATURES EXPECTED FOR INTERIOR SECTIONS. && .SHORT TERM (TODAY-TUE)...THE LAST OF THIS LATEST LITTLE SUBTROPICAL SURGE IS MOVING THROUGH THIS MORNING WITH A FEW SPRINKLES AROUND, MAINLY FOR SLO AND NRN SBA COUNTY. A SURPRISINGLY DEEP AND SOLID MARINE LYR HAS FORMED IN IT`S WAKE ACROSS LA COUNTY WITH TOPS AROUND 3500`. BY AFTERNOON SKIES SHOULD BECOME PARTLY CLOUDY EVERYWHERE WITH HIGHS STILL A FEW DEGREES BELOW NORMAL. MODELS INDICATING SOME INSTABILITY ACROSS THE INTERIOR THIS AFTERNOON AND CAN`T ARGUE WITH SLIGHT CHANCES OF THUNDERSTORMS THERE, THOUGH HRRR MODEL SHOWS VIRTUALLY NOTHING DEVELOPING ONCE THIS BAND OF SPRINKLES MOVES THROUGH LATER THIS MORNING. NAM12 CAPE IS FAIRLY IMPRESSIVE THOUGH AT GREATER THAN 1200 J/KG ACROSS VENTURA COUNTY AND JUST SLIGHTLY LESS ACROSS THE SAN GABRIELS. ***FROM PREVIOUS DISCUSSION*** ANY SHOWER/TSTM ACTIVITY SHOULD END BY MID OR LATE EVENING...THEN SKIES WILL BECOME MOSTLY CLEAR. THE WRF INDICATES A FAIRLY SOLID STRATUS PATTERN IN COASTAL AND MOST VALLEY AREAS BY LATE TONIGHT...WHICH SEEMS REASONABLY AS MID LEVEL MOISTURE DECREASES. LOW CLOUDS SHOULD CLEAR BY LATE MORNING MON IN MOST AREAS. SMALL RISES IN HEIGHTS AND THICKNESSES MAY BRING A COUPLE OF DEGREES OF WARMING TO INTERIOR SECTIONS ON MONDAY...BUT MAX TEMPS STILL WILL BE BELOW NORMAL. AN UPPER HIGH OVER THE S CENTRAL U.S. WILL BEGIN TO EXPAND WESTWARD TOWARD THE AREA MON NIGHT AND TUE...AS A WEAK UPPER LOW WELL OFF THE COAST OPENS UP AND LIFT NEWD TOWARD CENTRAL AND NRN CA. HEIGHTS AND THICKNESSES WILL RISE ACROSS THE REGION TUE. THE MARINE LAYER WILL LIKELY SHRINK IN DEPTH...BUT NIGHT/MORNING LOW CLOUDS AND FOG WILL PROBABLY STILL PUSH INTO COASTAL AND AT LEAST THE LOWER VLY LOCATIONS. MAX TEMPS WILL BE UP A FEW DEGREES ON TUESDAY... ESPECIALLY IN THE VLYS...MTNS AND DESERTS...BUT SHOULD STILL BE A BIT BELOW NORMAL. .LONG TERM (WED-SAT)...THE UPPER HIGH WILL CONTINUE TO EXPAND INTO THE REGION FROM THE EAST WED AND THU...AND HEIGHTS/THICKNESSES WILL CONT TO RISE. NIGHT THROUGH MORNING STRATUS WILL BECOME CONFINED TO THE COASTAL PLAIN. THERE WILL BE WARMING BOTH WED AND THU...WITH TEMPS RISING TO ABOVE NORMAL LEVELS IN MOST AREAS. MAX TEMPS SHOULD REACH 100 DEGREES IN THE ANTELOPE VALLEY ON WED...AND IN THE WARMER VALLEY LOCATIONS WEST OF THE MTNS BY THU. EXPECT LITTLE CHANGE FOR FRI AND SAT AS THE UPPER HIGH REMAINS LOCKED IN PLACE NEAR THE FOUR CORNERS REGION. THE UPPER PATTERN WILL BECOME MORE FAVORABLE TO SEND SOME MONSOONAL MOISTURE INTO THE REGION BY SAT...BUT FOR NOW...MODELS KEEP MOST OF THE MOISTURE TO THE E OF THE AREA. && .AVIATION... 20/1140Z VERY CHAOTIC PATTERN TODAY WITH LOW LEVEL AND MID LEVEL MOISTURE WITH SOME SHOWERS MIXED IN. ANY COASTAL STATION COULD SEE MVFR CIGS THROUGH 18Z BUT ONLY THE KLAX AND KLGB HAVE A GREATER THAN 50% CHC. ALL STATIONS HAVE A 30 PERCENT CHC OF A SHOWER THROUGH 20Z. THERE WILL BE A CHANCE OF TSTM OVER THE MTNS THIS AFTERNOON. THE MARINE LAYER STRATUS SHOULD BE MORE EXTENSIVE TONIGHT. .KLAX...FAIRLY LOW CONFIDENCE IN TAF. MVFR CIGS COULD DISSIPATE ANY TIME BETWEEN 14Z AND 18Z. THERE IS A 20 PERCENT CHC OF A SHOWER THROUGH 20Z. GOOD CONFIDENCE IN MVFR CIGS AFTER 05Z. .KBUR...FAIR CONFIDENCE IN TAF. MVFR CIGS COULD LAST TIL 16Z. THERE IS A 20 PERCENT CHC OF A SHOWER THROUGH 20Z. && .MARINE...20/900 AM NO SIGNIFICANT MARINE ISSUES ARE EXPECTED THROUGH MONDAY. ON TUESDAY WINDS ACROSS THE OUTER WATERS WILL BEGIN TO INCREASE...POSSIBLY APPROACHING ADVISORY LEVELS. MODERATE CONFIDENCE IN GUSTY NORTHWEST WINDS CONTINUING ACROSS THE OUTER WATERS WEDNESDAY THROUGH THURSDAY WITH NEAR GALE FORCE GUSTS POSSIBLE AROUND POINT CONCEPTION. && .LOX WATCHES/WARNINGS/ADVISORIES... NONE && $$ PUBLIC...MW/DB AVIATION...RORKE MARINE...RAT SYNOPSIS...SWEET WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
847 AM PDT SUN JUL 20 2014 .SYNOPSIS...MONSOONAL MOISTURE WILL CONTINUE TO PRODUCE ISOLATED LIGHT SHOWERS ACROSS THE REGION TODAY. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS AS WELL. MILD TEMPERATURES WILL CONTINUE THROUGH THE MIDDLE OF NEXT WEEK...WITH A WARMING TREND FORECAST FOR INLAND AREAS DURING THE SECOND HALF OF THE WEEK. && .DISCUSSION...AS OF 8:47 AM PDT SUNDAY...SHORT TERM FOCUS WILL BE ON SHOWERS/SPRINKLES THIS MORNING AND ISOLATED T-STORM POTENTIAL THIS AFTERNOON. KMUX-88D CONTINUES TO SHOW SHOWER ACTIVITY ACROSS THE NORTH BAY BUT SIMILAR TO THE LAST 24 HOURS AND PREVIOUS MONSOON EVENTS ITS ONLY DROPPING TRACE AMOUNTS OF RAIN WITH NUMEROUS REPORTS OF VIRGA. NONETHELESS BRIEF SHOWERS WITH BIG DROPS THAT WILL BE JUST ENOUGH TO WET THE GROUND WILL CONTINUE TO BE MOST LIKELY IN THE NORTH AND EAST BAY THIS MORNING. ON WATER VAPOR THERE IS A VERY WELL DEFINED VORTICITY MAXIMA CURRENTLY ROTATING OVER TULARE COUNTY. THIS FEATURE IN COMBINATION WITH THE HIGH SIERRA HAS PRODUCED NUMEROUS LIGHTNING STRIKES THIS MORNING (NOT THE USUAL AFTERNOON STUFF) OVER THE CREST. THE NAM/HRRR AND RUC SHORT TERM MESOSCALE MODELS HAVE BEEN PRETTY CONSISTENT IN DEVELOPING SOME POSSIBLE T-STORMS BY EARLY THIS AFTERNOON OVER SOUTHEASTERN SAN BENITO AND MONTEREY COUNTIES. ROUGHLY IN THE VICINITY OF SANTA RITA MOUNTAIN/PRIEST VALLEY/PARKFIELD/HWY 198. WILL CONTINUE TO MONITOR THIS REGION FOR POSSIBLE T-STORMS THIS AFTERNOON WITH CLEAR SKIES CURRENTLY OVER THE REGION WHICH SHOULD HELP TO DESTABILIZE THINGS. EVEN THOUGH AIRMASS IS VERY MOIST AND WERE NOT SEEING DRY THUNDERSTORMS ANY LIGHTNING STRIKES OVER THE INTERIOR HILLS REMAIN SUSCEPTIBLE TO NEW FIRE IGNITIONS. OUTSIDE OF THE ISOLATED SPRINKLES...ETC IT SHOULD BE A FAIRLY NICE SUNDAY AFTERNOON FOR MOST LOCATIONS WITH BREAKS IN THE CLOUDS AND COMFORTABLE TEMPERATURES IN THE 70S AND 80S MOST LOCATIONS. LOOKING AHEAD TO THE WORK WEEK...A TROUGH OFF THE COAST SHOULD TURN THE MAIN FLOW BACK TO WSW WHICH WILL PUT AN END TO THE MONSOON THREAT LOCALLY (STILL PLENTY OF AFTERNOON STORMS IN THE SIERRA). NEAR OR EVEN SLIGHTLY BELOW NORMAL TEMPERATURES EARLY IN THE WEEK SHOULD TREND UPWARDS...ESPECIALLY INLAND AS THE DOMINATE HIGH OVER THE ROCKIES/FOUR-CORNERS REGION EXPANDS WESTWARD ONCE AGAIN. && .PREV DISCUSSION...AS OF 3:35 AM PDT SUNDAY...SUBTROPICAL MOISTURE CONTINUES TO STREAM ACROSS CALIFORNIA EARLY THIS MORNING. PRECIPITABLE WATER VALUES ARE AS HIGH AS 1.5 INCHES JUST TO THE SOUTH OF OUR CWA. RADAR SHOWS THAT WIDELY SCATTERED LIGHT SHOWER ACTIVITY IS CURRENTLY TRACKING FROM EAST TO WEST ACROSS MONTEREY AND SAN BENITO COUNTIES. EXPECT ISOLATED SHOWER ACTIVITY TO SPREAD NORTHWARD THROUGH TODAY AS A SHORTWAVE TROUGH CURRENTLY OVER SOUTHERN CA LIFTS TO THE NORTHWEST. LIGHTNING STRIKES WERE DETECTED IN WESTERN FRESNO COUNTY A FEW HOURS AGO AND THE NAM CONTINUES TO SHOW A TREND TOWARDS GREATER INSTABILITY. SO WILL CONTINUE TO FORECAST ISOLATED SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS THROUGH THE DAY TODAY. THUNDERSTORM POTENTIAL LOOKS TO BE GREATEST ACROSS THE SOUTHERN HALF OF OUR FORECAST AREA WHERE THE NAM FORECASTS MU CAPE VALUES IN EXCESS OF 200 J/KG. MOST PRECIPITATION TODAY WILL BE LIGHT AND BRIEF AND SO ONLY ISOLATED MEASURABLE RAINFALL IS EXPECTED. THE BEST POTENTIAL FOR WETTING RAIN IS ACROSS SOUTHEAST SAN BENITO COUNTY WHERE THE NAM FORECASTS MORE THAN A QUARTER OF AN INCH OF RAIN. SUBTROPICAL MOISTURE WILL LIFT VERY SLOWLY NORTH THROUGH TONIGHT. RECENT MODEL OUTPUT SUGGEST ONLY GRADUAL SOUTH-TO-NORTH CLEARING OF MID AND HIGH LEVEL CLOUDS TONIGHT. IN FACT...IT NOW LOOKS LIKE MOISTURE MAY BE HUNG UP ACROSS THE NORTH BAY THROUGH AT LEAST MONDAY MORNING AS A DEFORMATION ZONE DEVELOPS BETWEEN SOUTHERLY FLOW ACROSS CENTRAL AND SOUTHERN CA AND AN UPPER TROUGH DROPPING SOUTH OFF THE COAST OF THE PAC NW. IT`S UNLIKELY THERE WILL BE MUCH PRECIP AFTER TODAY...BUT HAVE GONE AHEAD AND MAINTAINED A SLIGHT CHANCE OF SHOWERS ACROSS THE NORTH BAY THROUGH THIS EVENING GIVEN RECENT MODEL TRENDS. MOST SUBTROPICAL MOISTURE WILL EXIT OUR AREA BY LATE MONDAY AS THE FLOW ALOFT TURNS TO THE SOUTHWEST. BUT THEN...THE MODELS BRING ONE MORE BRIEF SHOT OF SUBTROPICAL MOISTURE ACROSS OUR AREA FROM THE SSW ON MONDAY NIGHT AS A TROUGH OFF THE COAST OF SOUTHERN CA LIFTS TO THE NE. IT`S DOUBTFUL WE WILL SEE MORE THAN SOME PASSING MID AND HIGH LEVEL CLOUDS WITH THIS...BUT WILL NEED TO MONITOR FOR THE POTENTIAL FOR ADDITIONAL ISOLATED SHOWERS/THUNDERSTORMS ON MONDAY NIGHT. INCREASED MID/HIGH LEVEL CLOUD COVER TODAY WILL MEAN SLIGHTLY COOLER TEMPERATURES COMPARED TO YESTERDAY. COOLER THAN NORMAL INLAND TEMPS WILL THEN CONTINUE INTO MONDAY AND TUESDAY AS THE UPPER LOW OFF THE SOUTHERN CA COAST LIFTS NORTHEAST...BRINGING IN A SLIGHTLY COOLER AIRMASS AND ENHANCING ONSHORE FLOW. HOWEVER...COASTAL AREAS WILL CONTINUE TO SEE NEAR NORMAL OR EVEN SLIGHTLY ABOVE NORMAL TEMPERATURES DUE TO WARMER THAN AVERAGE SEA SURFACE TEMPS WHICH ARE A BYPRODUCT OF A RECENT LACK OF NORTHWESTERLY FLOW ALONG THE COAST AND THUS A REDUCTION IN UPWELLING. THE MODELS HAVE BEEN CONSISTENT IN BUILDING AN UPPER RIDGE ACROSS CA FROM THE EAST DURING THE SECOND HALF OF THE WEEK. THIS WILL MEAN WARMER TEMPS ACROSS OUR AREA FROM THURSDAY INTO NEXT WEEKEND. MOST WARMING WILL OCCUR ACROSS INLAND AREAS WHERE HIGHS WILL CLIMB INTO THE 90S IN THE WARMEST SF BAY AREA VALLEYS AND BACK OVER 100 IN INTERIOR MONTEREY AND SAN BENITO COUNTIES. PERSISTENT ONSHORE FLOW AND A SHALLOW MARINE LAYER WILL KEEP COASTAL AREAS FROM WARMING MORE THAN A FEW DEGREES. && .AVIATION...AS OF 4:39 AM PDT SUNDAY...MONSOON MOISTURE IS STREAMING OVER THE FORECAST AREA THIS MORNING WITH SHOWERS POPPING UP OVER MONTEREY AND SAN BENITO COUNTIES AT THIS HOUR. MOISTURE AND INSTABILITY WILL MAINTAIN OCCASIONAL SHOWERS IN THE VICINITY OF THE TERMINALS THROUGHOUT THE DAY TODAY WITH AN ISOLATED THUNDERSTORM POSSIBLE THIS AFTERNOON. VICINITY OF KSFO...SCT008 WILL START THE DAY OFF WITH A PERIOD OF BKN008 POSSIBLE BETWEEN 1200 AND 1400Z THIS MORNING. BKN015 IS EXPECTED AT 1400Z BUT WILL BURN OFF BY 1630Z. WESTERLY WINDS WILL INCREASE TO 10 TO 15 KT THIS AFTERNOON WITH GUSTS TO 22 KT. CONFIDENCE MODERATE. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS BKN-OVC015 ARE EXPECTED TO IMPROVE TO VFR AT KMRY BY 1700Z. OCCASIONAL LIGHT SHOWERS WILL PASS OVER MONTEREY THIS MORNING WITH VICINITY SHOWERS EXPECTED OCCASIONALLY THROUGHOUT THE DAY TODAY. CONFIDENCE MODERATE. && .MARINE...AS OF 4:27 AM PDT SUNDAY...A WEAK SURFACE PRESSURE GRADIENT WILL MAINTAIN LIGHT WINDS AND GENTLE SEAS THROUGH THE WEEKEND ACROSS THE COASTAL WATERS. NORTHWESTERLY WINDS WILL INCREASE BY MID WEEK AS A THERMAL TROUGH SETS UP OVER INTERIOR CALIFORNIA. && .FIRE WEATHER....AS OF 4:30 AM PDT SUNDAY...WIDELY SCATTERED LIGHT SHOWERS ARE FORECAST ACROSS THE DISTRICT TODAY. A FEW ISOLATED LIGHTNING STRIKES ARE POSSIBLE...ESPECIALLY ACROSS THE SOUTH. HOWEVER...LIGHTNING IS UNLIKELY GIVEN THAT ONLY MARGINALLY UNSTABLE CONDITIONS WILL EXIST. ALSO...IF LIGHTNING DOES OCCUR IT WILL LIKELY BE ACCOMPANIED BY RAINFALL. MONSOONAL MOISTURE WILL GRADUALLY MOVE NORTH AND OUT OF THE AREA BY MIDDAY MONDAY. TEMPERATURES WILL REMAIN NEAR SEASONABLE NORMS THROUGH MIDWEEK AS LIGHT ONSHORE FLOW CONTINUES. HIGH PRESSURE WILL STRENGTHEN ACROSS CALIFORNIA DURING THE SECOND HALF OF THE WEEK...RESULTING IN WARMER AND DRIER WEATHER STARTING ON THURSDAY...ESPECIALLY FOR INLAND AREAS. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 11 AM && $$ PUBLIC FORECAST: RWW AVIATION/MARINE: LARRY FIRE WX: DYKEMA VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1031 AM MDT SUN JUL 20 2014 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 308 AM MDT SUN JUL 20 2014 NO MAJOR CHANGES IN FORECAST THINKING AS THE NOSE OF A 60+KT JET STREAK MOVES INTO THE 4 CORNERS REGION TODAY. THIS UPPER LEVEL SUPPORT WILL ALLOW MORE WIDESPREAD CONVECTION TO FIRE WHILE ALSO INCREASING MOISTURE CONTENT. GRAND JUNCTION RAOB SHOWED .46 INCHES OF PWAT YESTERDAY EVENING WHICH THE NAM12 FORECAST FAIRLY WELL. TODAY...THE NAM12 IS SHOWING AN INCREASE TO ABOUT .8 INCHES BY THIS AFTERNOON SO 2 INGREDIENTS...LIFT FROM THE JET AND INCREASING MOISTURE...ARE IN PLACE. LAPSE RATES DO BECOME STEEPER THIS AFTERNOON WITH FORECAST SKEW-TS SHOWING CONDITIONAL INSTABILITY ACROSS THE CWA SO WITH ALL 3 INGREDIENTS IN PLACE...STORMS AND SHOWERS ARE A SOLID BET. SOME SHEAR ALSO EXISTS WHICH WILL ALLOW STORMS TO PERSIST A LITTLE LONGER THAN THE POP AND DROP WE`VE SEEN OVER THE LAST FEW DAYS SO DO EXPECT SOME RAINSHOWERS AND THUNDERSTORMS TO DRIFT INTO VALLEYS LATER IN THE DAY. HRRR REALLY LIGHTING UP THE SAN JUANS WHICH IS ALSO FAVORED BY BOTH THE GFS AND NAM SO HIGH POPS IN PLACE LOOK GOOD. SHOWERS AND THUNDERSTORMS ARE NOT EXPECTED TO INITIATE AFTER SUNSET...BUT WILL MAINTAIN ORGANIZATION THROUGH ABOUT MIDNIGHT WITH THE 60KT JET STREAK AT H3 PLAYING A ROLE. A WEDGE OF DRY AIR WILL MOVE INTO THE REGION ON MONDAY AS THE LOW OFF OF THE COAST OF CALIFORNIA RETREATS WEST AND THE UPPER LEVEL HIGH CAN SHIFT BACK OVER SOUTHERN COLORADO AND NORTHERN NEW MEXICO. AS MENTIONED BY THE PREVIOUS FORECASTER...THIS IS USUALLY A GOOD POSITION TO BE PULLING MONSOON MOISTURE TO THE 4 CORNERS...BUT THE AMPLIFICATION OF THE RIDGE TO THE NORTH WILL BE SUPPRESSED BY A DIP IN THE POLAR JET STREAM ACROSS THE NORTHERN US BORDER. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 235 AM MDT SUN JUL 20 2014 THIS JET RETREATS NORTHWEST ON TUESDAY AFTERNOON. SOUTHWEST FLOW WILL PULL SUBTROPICAL MOISTURE BACK INTO SOUTHERN COLORADO BEGINNING LATE TUESDAY. THE CENTER OF HIGH PRESSURE WILL WOBBLE OVER OUR FORECAST AREA FROM WEDNESDAY THROUGH SATURDAY WITH MOISTURE UNDER THE RIDGE RECYCLING EACH DAY ALLOWING CONVECTION TO FIRE WEDNESDAY INTO THURSDAY. AFTER THAT...A CLOSED LOW WILL MOVE ACROSS THE US/CANADIAN BORDER FLATTENING THE HIGH PRESSURE OVER US. THIS FLATTENING WILL CAUSE WINDS TO BECOME W TO NWLY AND LIMITING THE MEAGER AMTS OF MOISTURE THAT WERE STREAMING UP FROM THE SOUTH. DUE TO THIS...FRIDAY AND SATURDAY LOOK TO BE HOT AND DRY WITH LITTLE...IF ANY...PRECIP EXPECTED. TEMPERATURES WILL CONTINUE TO RUN HOT...ABOUT 5 DEGREES ABOVE NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1031 AM MDT SUN JUL 20 2014 A SURGE OF MONSOON MOISTURE WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH 04Z/MON. THIS ACTIVITY WILL FAVOR THE MOUNTAINS...THOUGH A NUMBER OF CELLS WILL DRIFT OVER ADJACENT VALLEYS TO THE NORTHEAST. EXPECT AREAS OF MOUNTAIN OBSCURATION AND STRONG OUTFLOW WINDS FROM 35 TO 45 MPH. TAF SITES WILL MAINLY EXPERIENCE VFR CONDITIONS...THOUGH THERE IS A 30 TO 40 PERCENT CHANCE STORMS WILL PASS OVERHEAD. STRONGER CELLS COULD RESULT IN MVFR VSBY IN HEAVY RAIN. LATER TONIGHT THUNDERSTORM ACTIVITY DIES OFF WITH DRIER AIR FILTERING OVER THE AREA MONDAY...ESPECIALLY NORTH. AS A RESULT...EXPECT JUST A FEW STORMS OVER THE SOUTHERN MOUNTAINS DURING THE AFTERNOON WITH LITTLE CHANCE THAT TAF SITES WILL BE IMPACTED. && .FIRE WEATHER... ISSUED AT 308 AM MDT SUN JUL 20 2014 AN APPROACHING UPPER LEVEL DISTURBANCE WILL MOVE OVER UT/CO TODAY AND MONDAY WITH THE STRONGEST WINDS MOVING OVER MONDAY...ESPECIALLY FOR NORTHERN PORTIONS OF COLORADO. DEEP MIXING IS FORECAST TO REACH 500MB OR SO ALLOWING SFC WINDS TO REACH 20 KTS WITH OCCASIONAL GUSTS TO 30 KTS. ALONG WITH THE WINDS...SFC RH`S WILL BE BETWEEN 10 TO 15 PERCENT AS DRY AIR REMAINS ACROSS THE AREA. THIS COMBINATION WILL CAUSE CRITICAL FIRE WEATHER CONDITIONS FOR CO FIRE ZONE 200. TO THAT END...WILL ISSUE A FIRE WEATHER WATCH FOR THAT ZONE ON MONDAY FROM NOON TO 8PM. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR COZ200. UT...NONE. && $$ SHORT TERM...TGR/JAM LONG TERM...JAM/TGR AVIATION...NL FIRE WEATHER...TGR
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
315 AM MDT SUN JUL 20 2014 CORRECTED TO INCLUDE FIRE WEATHER WATCH IN GJT WATCHES/WARNINGS SECTION .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 308 AM MDT SUN JUL 20 2014 NO MAJOR CHANGES IN FORECAST THINKING AS THE NOSE OF A 60+KT JET STREAK MOVES INTO THE 4 CORNERS REGION TODAY. THIS UPPER LEVEL SUPPORT WILL ALLOW MORE WIDESPREAD CONVECTION TO FIRE WHILE ALSO INCREASING MOISTURE CONTENT. GRAND JUNCTION RAOB SHOWED .46 INCHES OF PWAT YESTERDAY EVENING WHICH THE NAM12 FORECAST FAIRLY WELL. TODAY...THE NAM12 IS SHOWING AN INCREASE TO ABOUT .8 INCHES BY THIS AFTERNOON SO 2 INGREDIENTS...LIFT FROM THE JET AND INCREASING MOISTURE...ARE IN PLACE. LAPSE RATES DO BECOME STEEPER THIS AFTERNOON WITH FORECAST SKEW-TS SHOWING CONDITIONAL INSTABILITY ACROSS THE CWA SO WITH ALL 3 INGREDIENTS IN PLACE...STORMS AND SHOWERS ARE A SOLID BET. SOME SHEAR ALSO EXISTS WHICH WILL ALLOW STORMS TO PERSIST A LITTLE LONGER THAN THE POP AND DROP WE`VE SEEN OVER THE LAST FEW DAYS SO DO EXPECT SOME RAINSHOWERS AND THUNDERSTORMS TO DRIFT INTO VALLEYS LATER IN THE DAY. HRRR REALLY LIGHTING UP THE SAN JUANS WHICH IS ALSO FAVORED BY BOTH THE GFS AND NAM SO HIGH POPS IN PLACE LOOK GOOD. SHOWERS AND THUNDERSTORMS ARE NOT EXPECTED TO INITIATE AFTER SUNSET...BUT WILL MAINTAIN ORGANIZATION THROUGH ABOUT MIDNIGHT WITH THE 60KT JET STREAK AT H3 PLAYING A ROLE. A WEDGE OF DRY AIR WILL MOVE INTO THE REGION ON MONDAY AS THE LOW OFF OF THE COAST OF CALIFORNIA RETREATS WEST AND THE UPPER LEVEL HIGH CAN SHIFT BACK OVER SOUTHERN COLORADO AND NORTHERN NEW MEXICO. AS MENTIONED BY THE PREVIOUS FORECASTER...THIS IS USUALLY A GOOD POSITION TO BE PULLING MONSOON MOISTURE TO THE 4 CORNERS...BUT THE AMPLIFICATION OF THE RIDGE TO THE NORTH WILL BE SUPPRESSED BY A DIP IN THE POLAR JET STREAM ACROSS THE NORTHERN US BORDER. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 235 AM MDT SUN JUL 20 2014 THIS JET RETREATS NORTHWEST ON TUESDAY AFTERNOON. SOUTHWEST FLOW WILL PULL SUBTROPICAL MOISTURE BACK INTO SOUTHERN COLORADO BEGINNING LATE TUESDAY. THE CENTER OF HIGH PRESSURE WILL WOBBLE OVER OUR FORECAST AREA FROM WEDNESDAY THROUGH SATURDAY WITH MOISTURE UNDER THE RIDGE RECYCLING EACH DAY ALLOWING CONVECTION TO FIRE WEDNESDAY INTO THURSDAY. AFTER THAT...A CLOSED LOW WILL MOVE ACROSS THE US/CANADIAN BORDER FLATTENING THE HIGH PRESSURE OVER US. THIS FLATTENING WILL CAUSE WINDS TO BECOME W TO NWLY AND LIMITING THE MEAGER AMTS OF MOISTURE THAT WERE STREAMING UP FROM THE SOUTH. DUE TO THIS...FRIDAY AND SATURDAY LOOK TO BE HOT AND DRY WITH LITTLE...IF ANY...PRECIP EXPECTED. TEMPERATURES WILL CONTINUE TO RUN HOT...ABOUT 5 DEGREES ABOVE NORMAL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 308 AM MDT SUN JUL 20 2014 TRANQUIL CONDITIONS OVERNIGHT WILL CHANGE FROM ABOUT 17Z WHEN CONVECTION WILL FIRE IN RESPONSE TO AN UPPER LEVEL DISTURBANCE MOVING OVERHEAD. COVERAGE WILL BE GREATER THAN SEEN THE LAST FEW DAYS WITH PLENTY OF CU BUILD UP EXPECTED ALONG WITH THUNDERSTORMS AND RAINSHOWERS. HIGHER TERRAIN WILL BE FAVORED BUT SOME SHEAR WILL ALLOW SOME CONVECTION TO DRIFT INTO VALLEYS. SOME HEAVY RAIN IS ALSO POSSIBLE ALONG WITH GUSTY WINDS REACHING 40 MPH UNDER AND NEAR THE STRONGEST CELLS. PER THE NORM...INCLUDED VCTS FOR KASE...KEGE...AND KTEX LATER IN THE AFTERNOON. SOME CONVECTION MAY LINGER THROUGH 06Z THOUGH NO AERODROMES SHOULD BE AFFECTED AFTER 03Z. && .FIRE WEATHER... ISSUED AT 308 AM MDT SUN JUL 20 2014 AN APPROACHING UPPER LEVEL DISTURBANCE WILL MOVE OVER UT/CO TODAY AND MONDAY WITH THE STRONGEST WINDS MOVING OVER MONDAY...ESPECIALLY FOR NORTHERN PORTIONS OF COLORADO. DEEP MIXING IS FORECAST TO REACH 500MB OR SO ALLOWING SFC WINDS TO REACH 20 KTS WITH OCCASIONAL GUSTS TO 30 KTS. ALONG WITH THE WINDS...SFC RH`S WILL BE BETWEEN 10 TO 15 PERCENT AS DRY AIR REMAINS ACROSS THE AREA. THIS COMBINATION WILL CAUSE CRITICAL FIRE WEATHER CONDITIONS FOR CO FIRE ZONE 200. TO THAT END...WILL ISSUE A FIRE WEATHER WATCH FOR THAT ZONE ON MONDAY FROM NOON TO 8PM. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...FIRE WEATHER WATCH FROM NOON MONDAY THROUGH MONDAY EVENING FOR COZ200. UT...NONE. && $$ SHORT TERM...TGR/JAM LONG TERM...JAM/TGR AVIATION...TGR FIRE WEATHER...TGR
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
309 AM MDT SUN JUL 20 2014 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 308 AM MDT SUN JUL 20 2014 NO MAJOR CHANGES IN FORECAST THINKING AS THE NOSE OF A 60+KT JET STREAK MOVES INTO THE 4 CORNERS REGION TODAY. THIS UPPER LEVEL SUPPORT WILL ALLOW MORE WIDESPREAD CONVECTION TO FIRE WHILE ALSO INCREASING MOISTURE CONTENT. GRAND JUNCTION RAOB SHOWED .46 INCHES OF PWAT YESTERDAY EVENING WHICH THE NAM12 FORECAST FAIRLY WELL. TODAY...THE NAM12 IS SHOWING AN INCREASE TO ABOUT .8 INCHES BY THIS AFTERNOON SO 2 INGREDIENTS...LIFT FROM THE JET AND INCREASING MOISTURE...ARE IN PLACE. LAPSE RATES DO BECOME STEEPER THIS AFTERNOON WITH FORECAST SKEW-TS SHOWING CONDITIONAL INSTABILITY ACROSS THE CWA SO WITH ALL 3 INGREDIENTS IN PLACE...STORMS AND SHOWERS ARE A SOLID BET. SOME SHEAR ALSO EXISTS WHICH WILL ALLOW STORMS TO PERSIST A LITTLE LONGER THAN THE POP AND DROP WE`VE SEEN OVER THE LAST FEW DAYS SO DO EXPECT SOME RAINSHOWERS AND THUNDERSTORMS TO DRIFT INTO VALLEYS LATER IN THE DAY. HRRR REALLY LIGHTING UP THE SAN JUANS WHICH IS ALSO FAVORED BY BOTH THE GFS AND NAM SO HIGH POPS IN PLACE LOOK GOOD. SHOWERS AND THUNDERSTORMS ARE NOT EXPECTED TO INITIATE AFTER SUNSET...BUT WILL MAINTAIN ORGANIZATION THROUGH ABOUT MIDNIGHT WITH THE 60KT JET STREAK AT H3 PLAYING A ROLE. A WEDGE OF DRY AIR WILL MOVE INTO THE REGION ON MONDAY AS THE LOW OFF OF THE COAST OF CALIFORNIA RETREATS WEST AND THE UPPER LEVEL HIGH CAN SHIFT BACK OVER SOUTHERN COLORADO AND NORTHERN NEW MEXICO. AS MENTIONED BY THE PREVIOUS FORECASTER...THIS IS USUALLY A GOOD POSITION TO BE PULLING MONSOON MOISTURE TO THE 4 CORNERS...BUT THE AMPLIFICATION OF THE RIDGE TO THE NORTH WILL BE SUPPRESSED BY A DIP IN THE POLAR JET STREAM ACROSS THE NORTHERN US BORDER. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 235 AM MDT SUN JUL 20 2014 THIS JET RETREATS NORTHWEST ON TUESDAY AFTERNOON. SOUTHWEST FLOW WILL PULL SUBTROPICAL MOISTURE BACK INTO SOUTHERN COLORADO BEGINNING LATE TUESDAY. THE CENTER OF HIGH PRESSURE WILL WOBBLE OVER OUR FORECAST AREA FROM WEDNESDAY THROUGH SATURDAY WITH MOISTURE UNDER THE RIDGE RECYCLING EACH DAY ALLOWING CONVECTION TO FIRE WEDNESDAY INTO THURSDAY. AFTER THAT...A CLOSED LOW WILL MOVE ACROSS THE US/CANADIAN BORDER FLATTENING THE HIGH PRESSURE OVER US. THIS FLATTENING WILL CAUSE WINDS TO BECOME W TO NWLY AND LIMITING THE MEAGER AMTS OF MOISTURE THAT WERE STREAMING UP FROM THE SOUTH. DUE TO THIS...FRIDAY AND SATURDAY LOOK TO BE HOT AND DRY WITH LITTLE...IF ANY...PRECIP EXPECTED. TEMPERATURES WILL CONTINUE TO RUN HOT...ABOUT 5 DEGREES ABOVE NORMAL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 308 AM MDT SUN JUL 20 2014 TRANQUIL CONDITIONS OVERNIGHT WILL CHANGE FROM ABOUT 17Z WHEN CONVECTION WILL FIRE IN RESPONSE TO AN UPPER LEVEL DISTURBANCE MOVING OVERHEAD. COVERAGE WILL BE GREATER THAN SEEN THE LAST FEW DAYS WITH PLENTY OF CU BUILD UP EXPECTED ALONG WITH THUNDERSTORMS AND RAINSHOWERS. HIGHER TERRAIN WILL BE FAVORED BUT SOME SHEAR WILL ALLOW SOME CONVECTION TO DRIFT INTO VALLEYS. SOME HEAVY RAIN IS ALSO POSSIBLE ALONG WITH GUSTY WINDS REACHING 40 MPH UNDER AND NEAR THE STRONGEST CELLS. PER THE NORM...INCLUDED VCTS FOR KASE...KEGE...AND KTEX LATER IN THE AFTERNOON. SOME CONVECTION MAY LINGER THROUGH 06Z THOUGH NO AERODROMES SHOULD BE AFFECTED AFTER 03Z. && .FIRE WEATHER... ISSUED AT 308 AM MDT SUN JUL 20 2014 AN APPROACHING UPPER LEVEL DISTURBANCE WILL MOVE OVER UT/CO TODAY AND MONDAY WITH THE STRONGEST WINDS MOVING OVER MONDAY...ESPECIALLY FOR NORTHERN PORTIONS OF COLORADO. DEEP MIXING IS FORECAST TO REACH 500MB OR SO ALLOWING SFC WINDS TO REACH 20 KTS WITH OCCASIONAL GUSTS TO 30 KTS. ALONG WITH THE WINDS...SFC RH`S WILL BE BETWEEN 10 TO 15 PERCENT AS DRY AIR REMAINS ACROSS THE AREA. THIS COMBINATION WILL CAUSE CRITICAL FIRE WEATHER CONDITIONS FOR CO FIRE ZONE 200. TO THAT END...WILL ISSUE A FIRE WEATHER WATCH FOR THAT ZONE ON MONDAY FROM NOON TO 8PM. && $$ SHORT TERM...TGR/JAM LONG TERM...JAM/TGR AVIATION...TGR FIRE WEATHER...TGR
AREA FORECAST DISCUSSION
NWS ALBANY NY
1246 PM EDT SUN JUL 20 2014 .SYNOPSIS... A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR A FEW RAIN SHOWERS AND MOSTLY CLOUDY SKIES TODAY...MAINLY THIS MORNING. WARMER AND MORE HUMID CONDITIONS ARE EXPECTED DURING THE EARLY PORTION OF THE UPCOMING WEEK...BEFORE A COLD FRONT RETURNS MORE WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE REGION ON WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 638 AM EDT...A WEAK UPPER LEVEL SHORTWAVE IS MOVING ACROSS ONTARIO AND THE EASTERN GREAT LAKES. A VORTICITY MAX SWINGING AROUND THIS SHORTWAVE TROUGH HAS ALLOWED FOR SOME RAIN SHOWERS EARLY THIS MORNING FOR SOUTHERN AND EASTERN PORTIONS OF THE AREA. MOST OF THIS RAINFALL IS FALLING FROM A MID LEVEL CLOUD DECK...AND WITH DRY LOW LEVELS IN PLACE...MUCH OF THE RAINFALL IS EVAPORATING BEFORE REACHING THE GROUND. AS A RESULT...THE RADAR APPEARS MUCH MORE WORSE THAN WHAT IS ACTUALLY OCCURRING. STILL...WE WILL ALLOW FOR SLIGHT TO LOW CHC POPS THROUGH ABOUT 9 AM TO ACCOUNT FOR THIS ACTIVITY. THE 08Z 3KM HRRR SHOWS THIS ACTIVITY EXITING OUR EASTERN AREAS BY ABOUT MID MORNING. OUTSIDE THIS ACTIVITY...THERE COULD BE A BRIEF SHOWER CLOSER TO THE SHORTWAVE OVER THE ADIRONDACKS OR WESTERN MOHAWK VALLEY THIS AFTN...OTHERWISE MOST AREAS LOOK TO REMAIN DRY DURING THE DAY TODAY. IR SATELLITE IMAGERY SHOWS PLENTY OF CLOUDS AROUND THIS MORNING. THERE SHOULD BE SOME BREAKS OF SUN BY AFTERNOON AS THE TROUGH BEGINS TO WEAKEN...AS IT SHEARS OUT AND LIFTS INTO QUEBEC. WITH 850 HPA TEMPS AROUND 10-12 DEGREES C...AND MIXING OCCURRING TO ABOUT 825-850 HPA...MAX TEMPS SHOULD REACH THE UPPER 70S TO NEAR 80 FOR VALLEY AREAS. WITH DEWPOINTS STILL IN THE 50S...IT WON/T FEEL TOO HUMID OUT THERE EITHER...AND PWAT VALUES WILL CONTINUE TO RUN A LITTLE BELOW NORMAL FOR MID JULY...WITH READINGS AROUND 1.00 INCH. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... MAINLY DRY AND QUIET WEATHER WILL CONTINUE THROUGH THE SHORT TERM PERIOD. AS THE WEAK SHORTWAVE DEPARTS...THE UPPER LEVEL FLOW WILL BECOME ZONAL FOR MONDAY...WITH WEAK RIDGING STARTING TO BUILD IN BY TUESDAY. THE LOW LEVEL FLOW WILL BE OUT OF THE SOUTH...SO MOISTURE WILL GRADUALLY RETURN TO THE REGION...WITH HUMIDITY LEVELS STEADILY RISING OVER THE NEXT FEW DAYS. IN ADDITION...850 HPA TEMPS WILL WARM AS WELL...WITH +16 AT 850 HPA IN PLACE BY TUESDAY. AS A RESULT...MAX TEMPS LOOK TO REACH THE LOW 80S FOR VALLEY AREAS ON MONDAY...AND MID TO UPPER 80S ON TUESDAY. OVERNIGHT LOWS WILL BECOME WARMER EACH NIGHT...WITH 50S TONIGHT...LOW 60S FOR MON NIGHT...AND MID 60S FOR TUESDAY NIGHT. DEWPOINTS WILL BE BACK INTO THE UPPER 50S TO LOW 60S FOR MONDAY AND LOW TO MID 60S FOR TUESDAY. IT SHOULD BE FAIRLY DRY FOR MOST LOCATIONS OVER THE NEXT FEW DAYS DUE TO A LACK OF FORCING IN PLACE AND LIMITED MOISTURE. STILL...WE CANNOT TOTALLY RULE OUT A BRIEF SHOWER OR THUNDERSTORM THANKS TO DAYTIME HEATING DURING THE AFTN OR EVENING HOURS ON MON OR TUESDAY...MAINLY OVER THE HIGH TERRAIN. ANY SHOWER OR THUNDERSTORM WOULD BE BRIEF AND FAIRLY SPOTTY IN COVERAGE. && .LONG TERM /TUESDAY THROUGH SATURDAY/... A VERY WARM AND HUMID AIR MASS WILL BE ACROSS THE REGION FOR WEDNESDAY AS H850 TEMPS CLIMB TO NEAR 20C ALONG WITH A STRENGTHENING SOUTHWEST FLOW REGIME. FORECAST SURFACE DEWPOINTS ARE PROGGED TO BE WELL INTO THE 60S AND EVEN SOME LOWER 70S. THE APPARENT TEMPERATURE FORECAST /HEAT INDEX/ CLIMBS INTO THE MID 90S FOR VALLEY LOCATIONS WHICH IS BELOW ADVISORY LEVEL CRITERIA. OF MORE INTEREST WILL BE THE APPROACHING UPSTREAM COLD FRONT. AS MENTIONED IN PREVIOUS AFD/S FOR THIS TIME FRAME...WEDNESDAY INTO WEDNESDAY EVENING COULD PROVE TO BE RATHER ACTIVE WITH STRONG THUNDERSTORMS. BULK SHEAR VALUES CLIMB AT OR ABOVE 40KTS WITH FORECAST SBCAPES IN EXCESS OF 1K J/KG AS PWATS CLIMB AT OR ABOVE 1.75 INCHES. WE WILL RETAIN THE HIGH CHANCE POPS DURING THIS TIME FRAME AS GLOBAL MODELS STILL DIFFER WITH FROPA TIMING. THE NEXT CONCERN WILL THEN BE HOW QUICKLY THE FRONTAL BOUNDARY AND WAVE OF LOW PRESSURE THAT A COUPLE OF GLOBAL MODELS SUGGEST AND A FEW ENSEMBLE MEMBERS SUGGEST THAT SWEEP THROUGH THE REGION. THE GFS/GGEM REMAINS LAGGING THE FRONTAL PASSAGE WELL INTO THURSDAY DUE TO MULTIPLE SURFACES WAVES DEVELOPING ALONG THE FRONT AS IT SAGS SOUTHWARD. HOWEVER...THE ECMWF IS SHOWING MORE OF A PROGRESSIVE SOLUTION WITH HIGH PRESSURE RAPIDLY BUILDING IN FOR THURSDAY. WILL GO WITH A COMPROMISE FOR NOW AND MENTION CHANCE POPS FOR THURSDAY MORNING...BUT WILL DECREASE POPS BY AFTERNOON. TEMPERATURES WILL COOL BUT HUMIDITY LEVELS COULD STILL BE ELEVATED...ESPECIALLY IF THE GFS VERIFIES. MODELS ARE IN BETTER AGREEMENT FOR FRIDAY INTO SATURDAY. SURFACE HIGH PRESSURE IS EXPECTED TO BUILD IN FROM THE GREAT LAKES AND SOUTHEAST CANADA PROVIDING DRY CONDITIONS...HOWEVER...CYCLONIC FLOW ALOFT REMAINS. THIS SHOULD ALLOW FOR SEASONABLY WARM TEMPERATURES AND COMFORTABLE HUMIDITY LEVELS WITH DIURNALLY DRIVEN CLOUDS. THE GFS REMAINS THE MOST AGGRESSIVE WITH A STRONG PV ANOMALY DIVING SOUTHWARD TO BRING A SHOWER OR TWO ACROSS THE TERRAIN BUT ECMWF REMAINS LESS PRONOUNCED AS WE WILL KEEP POPS BELOW SLIGHT CHANCE THRESHOLDS. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... THE BATCH OF RAIN WAS QUICKLY EXITING THE BERKSHIRES LEAVING BEHIND A BKN VFR DECK. THIS WILL BE THE MAIN TREND FOR THE DAY WITH SCT-BKN MID AND HIGH LEVEL CLOUDS. WINDS WILL REMAIN RATHER LIGHT WITH A TENDENCY FROM THE SOUTHERLY DIRECTION. LATER TONIGHT...LIGHT WINDS AND SOME INCREASE IN LOWER LEVEL MOISTURE COULD BRING ABOUT SOME MIST/FOG. OUTLOOK... MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR A FEW RAIN SHOWERS TODAY...BUT COVERAGE WILL BE SPOTTY AND RAINFALL AMOUNTS WILL BE VERY LIGHT. AFTER A CLOUDY START...SOME SUN WILL BREAK OUT BY AFTERNOON WITH RH VALUES DROPPING TO AROUND 40 PERCENT WITH LIGHT S-SE WINDS AROUND 5 MPH. WINDS WILL BECOME NEARLY CALM TONIGHT WITH DEW FORMATION AND RH VALUES RETURNING TO 85-100 PERCENT IN MOST LOCATIONS. AN ISOLATED SHOWER IS POSSIBLE ON MONDAY AND TUESDAY...OTHERWISE A PARTLY CLOUDY SKY WILL BE IN PLACE WITH LIGHT SOUTHERLY WINDS AT 5-10 MPH. RH VALUES WILL DROP TO 40-50 PERCENT DURING THE AFTERNOON HOURS ON MONDAY AND AROUND 50 PERCENT ON TUESDAY AFTERNOON. && .HYDROLOGY... MAINLY DRY WEATHER IS EXPECTED THROUGH THE REMAINDER OF THE WEEKEND WITH JUST A LOW CHANCE FOR A BRIEF LIGHT RAIN SHOWER ACROSS PARTS OF THE AREA TODAY. AN ISOLATED SHOWER OR THUNDERSTORM CANNOT BE RULED OUT ON MONDAY OR TUESDAY EITHER...OTHERWISE DRY WEATHER LOOKS TO CONTINUE INTO FIRST PORTION OF THE UPCOMING WEEK. THERE WILL BE A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ON WEDNESDAY...AS A COLD FRONT APPROACHES THE AREA. WITH LITTLE OR NO RAINFALL...RIVER LEVELS WILL HOLD STEADY OR SLOWLY FALL OVER THE NEXT FEW DAYS. 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...FRUGIS/HWJIV NEAR TERM...FRUGIS/HWJIV/GJM SHORT TERM...FRUGIS LONG TERM...BGM AVIATION...BGM FIRE WEATHER...FRUGIS HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1019 AM EDT SUN JUL 20 2014 .SYNOPSIS... LOW PRESSURE LIFTING NORTHEAST FROM THE MID-ATLANTIC WILL BRING MOSTLY CLOUDY CONDITIONS ACROSS MUCH OF NEW ENGLAND WITH LIGHT SHOWERS FOR THE IMMEDIATE SOUTH AND SOUTHEAST COASTLINE THROUGH LATE TODAY. THEREAFTER...HIGH PRESSURE BUILDS INTO THE REGION BRINGING WITH IT DRY WEATHER ALONG WITH WARM AND HUMID CONDITIONS THROUGH MIDWEEK. A COLD FRONT FROM CANADA TRACKS THROUGH SOUTHERN NEW ENGLAND DURING THURSDAY...WITH HIGH PRESSURE RETURNING ON FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM UPDATE... SHOWERS TO CONTINUE ACROSS S/E PORTIONS OF NEW ENGLAND AS BROADSCALE MOIST FLOW FROM THE SW UNDERGOES ISENTROPIC LIFT AND ASCENT ALONG AND N OF A STALLED FRONTAL BOUNDARY IMMEDIATELY S OF NEW ENGLAND AND BENEATH THE RRQ OF THE UPPER-LEVEL JET. THIS WILL ALSO LEAD TO MOSTLY CLOUDY CONDITIONS OVER MUCH OF THE REGION. RIDGE OF HIGH PRESSURE AND ACCOMPANYING DRIER AIR THROUGH INTERIOR AND E/NE NEW ENGLAND WILL PRESENT CHALLENGES FOR RAIN IN REACHING THE SURFACE. BUT PER 12Z SOUNDING ANALYSIS...THE LOW-LEVEL DRY AIR IS NOT INCREDIBLY DEEP NOR ROBUST. SO SPRINKLES TO A STEADY RAIN IS CERTAINLY PLAUSIBLE BENEATH ANY AREAS OF RAINFALL OBSERVED BY RADAR. SO HAVE LIKELY POPS CLOSEST TO THE STALLED FRONTAL BOUNDARY MAINLY FOR S/SE PORTIONS OF THE FORECAST AREA INCLUDING CAPE COD AND THE ISLANDS /AGREEING WITH THE PREVIOUS FORECASTER OF A FOCUS ALONG THE I-95 CORRIDOR BETWEEN PROVIDENCE AND BOSTON/. CHANCE POPS FOR ADJACENT AREAS ESPECIALLY OVER E NEW ENGLAND. CLOUDY CONDITIONS TO PREVAIL OVER MUCH OF THE REGION WITH THE BEST CHANCE OF SEEING SUNSHINE MAINLY W. THUS HAVE WARMEST TEMPERATURES TODAY OVER THE CT-RIVER VALLEY OF AROUND 80-DEGREES WITH HIGHS AROUND THE LOW- TO MID-70S OVER E/SE NEW ENGLAND AS THE TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE RIDGE EMERGING TOWARDS THE SW FROM THE GULF OF MAINE AND LOW PRESSURE OFF THE MID-ATLANTIC INVOKES AN ISALLOBARIC RESPONSE OF BREEZY E/NE WINDS OFF THE COOLER WATERS. AS FOR NEAR-TERM MESOSCALE GUIDANCE...IT APPEARS THE HRRR IS CATCHING UP. BUT SUGGEST THE USE OF THE ECMWF TO INTERPRET THE BROADSCALE MOTIONS AND INFLUENCING FACTORS TO INTUIATIVELY DISCERN THE BEST CHANCES FOR RAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... TONIGHT...MID-LEVEL TROUGH WITH ACCOMPANYING LOW MOVING NORTHEAST INTO NOVA SCOTIA. SHOULD SEE THE RETURN OF HIGH PRESSURE DESPITE SOME LINGERING INFLUENCE OF THE TROUGH ACROSS THE EASTERN GREAT LAKES DOWN THROUGH THE OHIO RIVER VALLEY. ANTICIPATED LIGHT WINDS AND CLEARING CONDITIONS COULD MAKE FOR A PERIOD OF EFFECTIVE RADIATIONAL COOLING. WILL FORECAST LOWS NEAR TO SLIGHTLY BELOW NORMAL. MONDAY...SURFACE HIGH PRESSURE LOOKS TO BE IN CONTROL ACROSS SOUTHERN NEW ENGLAND. WITH A MID LEVEL CAP IN PLACE...EXPECTING SOME DIURNAL CUMULUS...BUT LOW PROBABILITY FOR SHOWERS. ONSHORE FLOW WILL KEEP MAX TEMPERATURES ON THE COOL SIDE TOWARD THE COASTS. ELSEWHERE...SEASONABLE MAX TEMPERATURES ARE EXPECTED WITH MORE SUNSHINE. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGHLIGHTS... * DRY TO START THE WORK WEEK. * BECOMING WARMER AND MORE HUMID THROUGH MID WEEK. * BEST CHANCE OF SHOWERS AND THUNDERSTORMS IN THE WEDNESDAY TO THURSDAY NIGHT TIMEFRAME WITH THE APPROACH AND PASSAGE OF A COLD FRONT. OVERVIEW AND MODEL PREFERENCES... WITH THE LATEST /20.00Z/ GUIDANCE SUITE...THE DIFFERENCES REGARDING A DIGGING TROF LATE IN THE WEEK ARE DIMINISHING. THE ECMWF...AND SOME ENSEMBLES ARE LESS AMPLIFIED AS THE TROF TRIES TO DIG INTO BUILDING RIDGE BOTH ACROSS THE SW CONUS AND SE ATLANTIC ASSOCIATED WITH THE BERMUDA HIGH. THEREFORE...THE TIMING OF A COLD FRONT FOR WED-THU APPEARS TO BE FASTER WITH HIGH PRES NOW DOMINATING THE LATTER PART OF THE WEEK. GIVEN THIS IDEA FITS THE PATTERN BETTER...FEEL A BLEND OF THIS LATEST ECMWF WITH OTHER OPERATIONAL GUIDANCE IS THE BEST COURSE OF ACTION WITH THIS UPDATE. THEREFORE...THE PERIOD WILL BE DOMINATED BY THESE TWO BUILDING RIDGES...ALLOWING FOR AN INFLUENCE OF THE BERMUDA HIGH THROUGH AT LEAST MID WEEK. THE WARMING/HIGHER HUMIDITY TREND IS FAVORED AS THE FLOW PATTERN WILL ALLOW H85 TEMPS TO REACH ALMOST +19C BY THU. IT IS NOT UNTIL THAT SLOWLY WEAKENING TROF ARRIVES LATE IN THE WEAK THAT A DRIER..ZONAL..AND COOLER AIRMASS IS ALLOWED TO MOVE IN. DETAILS... MON NIGHT INTO WED... GRADUALLY WARMING TEMPERATURES THANKS TO SW FLOW IS EXPECTED...ALONG WITH INCREASING DWPTS...REACHING THE UPPER 60S BY WED. H85 TEMPS OF +16C TUE SUGGEST TEMPS IN THE MID 80S WHERE SUNSHINE ALLOWS FULL MIXING...WHILE +18C SUGGESTS SOME HIGHS AROUND 90F ON WED. THE KEY EACH OF THESE DAYS WILL BE THEIR CONVECTIVE POTENTIAL. EACH DAY THE H7 TEMPS INCREASE...TO ABOUT +8C ON TUE...THEN NEAR +10C BY WED...SUGGESTING A BUILDING CAPPING INVERSION. ALSO...RRQ OF THE UPPER JET AND SLACKENING IN THE MASS FIELDS REMAINS TO THE N AND W EACH DAY. THEREFORE...SUSPECT THAT THE BEST CHANCE FOR ACTIVITY IS TO THE N AND W. ALSO...SHEAR IS MINIMAL AT BEST /GENERALLY BELOW 15 KT/ SO ANY CONVECTIVE ACTIVITY THAT IS ABLE TO OCCUR WILL LIKELY COLLAPSE QUICKLY. IN SUM...WILL GO WITH SOME LOW POPS..MAINLY ACROSS THE W EACH DAY...WITH SLIGHTLY HIGHER POPS ON WED THANKS TO THE FACT THAT ALL OF THESE FEATURES LINE UP SLIGHTLY BETTER. OVERNIGHT...SOME FOG IS POSSIBLE...PARTICULARLY TUE NIGHT AND WED NIGHT. THU... BETTER CHANCE FOR CONVECTIVE ACTIVITY AS UPPER LVL JET STREAK LINES UP IT/S RRQ OVER SRN NEW ENGLAND...WITH SFC BASED CAPE VALUES 1000-1500J/KG. SHEAR MAGNITUDES ARE HIGHER AS WELL...ON THE ORDER OF 40 KT. ALL AS A SFC COLD FRONT PUSHES THROUGH THE AREA. WILL HIGHLIGHT CHANCE POPS WITH THE POSSIBILITY OF CONVECTION. ALTHOUGH A SEVERE THREAT IS THERE...HAVE HIGHEST CONFIDENCE IN HEAVY RAIN AS PWATS APPROACH 2.0 INCHES. WITH THE LATEST RUNS...WILL BEGIN TO BRING IN DRIER AIR BY THU EVENING. FRI INTO THE WEEKEND... WITH THE MORE PROGRESSIVE SOLUTION NOW FAVORED...THE SHORTWAVE TROF IS EXPECTED TO LIFT TO THE NE AS ONCE AGAIN...THE SW RIDGE REGAINS CONTROL. HOWEVER...DO EXPECT THAT SOME DRIER...COOLER AIR WILL MOVE IN WITH HIGH PRES MOVING OVER FROM THE W-NW. THEREFORE...EXPECT A RETURN TO LOWER HUMIDITIES AND NEAR SEASONABLE TEMPERATURES UNTIL SW FLOW RETURNS BY SUN. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY/...HIGH CONFIDENCE. TODAY...HIGH CONFIDENCE. VFR. ALTHOUGH PERIODIC -SHRA ARE POSSIBLE THROUGH THE LATE MORNING AND AFTERNOON MAINLY S AND E OF A PVD-BOS LINE...VFR SHOULD DOMINATE IN THIS AS WELL. WINDS GENERALLY E-NE THROUGH THE DAY EXCEPT MAINLY N IN THE CT VALLEY. TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...ALTHOUGH BETTER CHANCE FOR SOME OVERNIGHT FOG WITH MVFR/IF ESPECIALLY ACK/FMH/HYA/MVY. NOT CONFIDENT ENOUGH TO PUT IN TAF EXCEPT ACK WITH THIS UPDATE. NE FLOW CONTINUES. TOMORROW...HIGH CONFIDENCE. MAINLY VFR AFTER ANY FOG BURNS OFF IN THE MORNING. LIGHT NE FLOW FOR MOST OF THE DAY. SEA BREEZES LIKELY AGAIN ON COASTS. KBOS TAF...HIGH CONFIDENCE IN TAF. KBDL TAF...HIGH CONFIDENCE IN TAF. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY... MON NIGHT INTO WED...MODERATE CONFIDENCE. MAINLY VFR. HOWEVER OVERNIGHT EACH NIGHT...THE THREAT FOR FOG WITH IFR/MVFR CONDITIONS IS POSSIBLE...PARTICULARLY ALONG THE S COAST. ISOLATED SHOWER/T-STORM POSSIBLE WED AFTERNOON MAINLY IN THE W. WED NIGHT INTO THU...MODERATE CONFIDENCE. A COLD FRONT CROSSES THE REGION...WITH A BETTER CHANCE FOR MORE WIDESPREAD SHOWERS OR THUNDERSTORMS AND MVFR/IFR CONDITIONS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY/...HIGH CONFIDENCE. 1030 AM UPDATE... HAVE HOISTED A SMALL-CRAFT ADVISORY FOR THE S/SE WATERS FOR THE PURPOSES OF NOTIFYING BOATERS OF THE THREAT OF GUSTY NORTHEAST WINDS AND POSSIBLE ENHANCEMENT OF SEAS FOR THE REMAINDER OF TODAY INTO THE EARLY EVENING HOURS. PART OF THIS IS DUE TO THE FACT THAT BUOY 44017 UP TO 4.6 FEET AT THIS HOUR AND GUSTS OF AROUND 20-25 KTS HAVE BEEN OBSERVED OVER NANTUCKET SOUND. WINDS WILL RELAX OVERNIGHT AND INTO MONDAY AS LOW PRESSURE SKIRTS OFF TOWARDS THE NORTHERN-ATLANTIC AND HIGH PRESSURE BUILDS BACK INTO THE REGION. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY... MON NIGHT THROUGH TUE...HIGH CONFIDENCE. HIGH PRES OVER THE WATERS SHOULD LEAD TO MAINLY QUIET BOATING WEATHER...WITH SW WINDS AND SEAS GENERALLY BELOW SMALL CRAFT ADVISORY THRESHOLDS. SOME FOG POSSIBLE BOTH MON AND TUE NIGHT WITH REDUCED VSBYS. WED AND THU...MODERATE CONFIDENCE. SW FLOW IS EXPECTED TO INCREASE WED AHEAD OF A COLD FRONT WHICH WILL CROSS THE WATERS EARLY THU. WINDS NEAR THE SE COAST OF MA MAY GUST TO AROUND 25 KT AT TIMES...POTENTIALLY REQUIRING A SMALL CRAFT ADVISORY. SEAS SHOULD REMAIN BELOW 5 FT THROUGH THE PERIOD HOWEVER. SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER THE WATERS PARTICULARLY LATE WED NIGHT AND THU. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ232- 254>256. && $$ SYNOPSIS...BELK/DOODY NEAR TERM...SIPPRELL SHORT TERM...BELK LONG TERM...DOODY AVIATION...DOODY/SIPPRELL MARINE...BELK/DOODY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1000 AM EDT SUN JUL 20 2014 .SYNOPSIS... LOW PRESSURE LIFTING NORTHEAST FROM THE MID-ATLANTIC WILL BRING MOSTLY CLOUDY CONDITIONS ACROSS MUCH OF NEW ENGLAND WITH LIGHT SHOWERS FOR THE IMMEDIATE SOUTH AND SOUTHEAST COASTLINE THROUGH LATE TODAY. THEREAFTER...HIGH PRESSURE BUILDS INTO THE REGION BRINGING WITH IT DRY WEATHER ALONG WITH WARM AND HUMID CONDITIONS THROUGH MIDWEEK. A COLD FRONT FROM CANADA TRACKS THROUGH SOUTHERN NEW ENGLAND DURING THURSDAY...WITH HIGH PRESSURE RETURNING ON FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM UPDATE... SHOWERS TO CONTINUE ACROSS S/E PORTIONS OF NEW ENGLAND AS BROADSCALE MOIST FLOW FROM THE SW UNDERGOES ISENTROPIC LIFT AND ASCENT ALONG AND N OF A STALLED FRONTAL BOUNDARY IMMEDIATELY S OF NEW ENGLAND AND BENEATH THE RRQ OF THE UPPER-LEVEL JET. THIS WILL ALSO LEAD TO MOSTLY CLOUDY CONDITIONS OVER MUCH OF THE REGION. RIDGE OF HIGH PRESSURE AND ACCOMPANYING DRIER AIR THROUGH INTERIOR AND E/NE NEW ENGLAND WILL PRESENT CHALLENGES FOR RAIN IN REACHING THE SURFACE. BUT PER 12Z SOUNDING ANALYSIS...THE LOW-LEVEL DRY AIR IS NOT INCREDIBLY DEEP NOR ROBUST. SO SPRINKLES TO A STEADY RAIN IS CERTAINLY PLAUSIBLE BENEATH ANY AREAS OF RAINFALL OBSERVED BY RADAR. SO HAVE LIKELY POPS CLOSEST TO THE STALLED FRONTAL BOUNDARY MAINLY FOR S/SE PORTIONS OF THE FORECAST AREA INCLUDING CAPE COD AND THE ISLANDS /AGREEING WITH THE PREVIOUS FORECASTER OF A FOCUS ALONG THE I-95 CORRIDOR BETWEEN PROVIDENCE AND BOSTON/. CHANCE POPS FOR ADJACENT AREAS ESPECIALLY OVER E NEW ENGLAND. CLOUDY CONDITIONS TO PREVAIL OVER MUCH OF THE REGION WITH THE BEST CHANCE OF SEEING SUNSHINE MAINLY W. THUS HAVE WARMEST TEMPERATURES TODAY OVER THE CT-RIVER VALLEY OF AROUND 80-DEGREES WITH HIGHS AROUND THE LOW- TO MID-70S OVER E/SE NEW ENGLAND AS THE TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE RIDGE EMERGING TOWARDS THE SW FROM THE GULF OF MAINE AND LOW PRESSURE OFF THE MID-ATLANTIC INVOKES AN ISALLOBARIC RESPONSE OF BREEZY E/NE WINDS OFF THE COOLER WATERS. AS FOR NEAR-TERM MESOSCALE GUIDANCE...IT APPEARS THE HRRR IS CATCHING UP. BUT SUGGEST THE USE OF THE ECMWF TO INTERPRET THE BROADSCALE MOTIONS AND INFLUENCING FACTORS TO INTUIATIVELY DISCERN THE BEST CHANCES FOR RAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... TONIGHT...MID-LEVEL TROUGH WITH ACCOMPANYING LOW MOVING NORTHEAST INTO NOVA SCOTIA. SHOULD SEE THE RETURN OF HIGH PRESSURE DESPITE SOME LINGERING INFLUENCE OF THE TROUGH ACROSS THE EASTERN GREAT LAKES DOWN THROUGH THE OHIO RIVER VALLEY. ANTICIPATED LIGHT WINDS AND CLEARING CONDITIONS COULD MAKE FOR A PERIOD OF EFFECTIVE RADIATIONAL COOLING. WILL FORECAST LOWS NEAR TO SLIGHTLY BELOW NORMAL. MONDAY...SURFACE HIGH PRESSURE LOOKS TO BE IN CONTROL ACROSS SOUTHERN NEW ENGLAND. WITH A MID LEVEL CAP IN PLACE...EXPECTING SOME DIURNAL CUMULUS...BUT LOW PROBABILITY FOR SHOWERS. ONSHORE FLOW WILL KEEP MAX TEMPERATURES ON THE COOL SIDE TOWARD THE COASTS. ELSEWHERE...SEASONABLE MAX TEMPERATURES ARE EXPECTED WITH MORE SUNSHINE. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGHLIGHTS... * DRY TO START THE WORK WEEK. * BECOMING WARMER AND MORE HUMID THROUGH MID WEEK. * BEST CHANCE OF SHOWERS AND THUNDERSTORMS IN THE WEDNESDAY TO THURSDAY NIGHT TIMEFRAME WITH THE APPROACH AND PASSAGE OF A COLD FRONT. OVERVIEW AND MODEL PREFERENCES... WITH THE LATEST /20.00Z/ GUIDANCE SUITE...THE DIFFERENCES REGARDING A DIGGING TROF LATE IN THE WEEK ARE DIMINISHING. THE ECMWF...AND SOME ENSEMBLES ARE LESS AMPLIFIED AS THE TROF TRIES TO DIG INTO BUILDING RIDGE BOTH ACROSS THE SW CONUS AND SE ATLANTIC ASSOCIATED WITH THE BERMUDA HIGH. THEREFORE...THE TIMING OF A COLD FRONT FOR WED-THU APPEARS TO BE FASTER WITH HIGH PRES NOW DOMINATING THE LATTER PART OF THE WEEK. GIVEN THIS IDEA FITS THE PATTERN BETTER...FEEL A BLEND OF THIS LATEST ECMWF WITH OTHER OPERATIONAL GUIDANCE IS THE BEST COURSE OF ACTION WITH THIS UPDATE. THEREFORE...THE PERIOD WILL BE DOMINATED BY THESE TWO BUILDING RIDGES...ALLOWING FOR AN INFLUENCE OF THE BERMUDA HIGH THROUGH AT LEAST MID WEEK. THE WARMING/HIGHER HUMIDITY TREND IS FAVORED AS THE FLOW PATTERN WILL ALLOW H85 TEMPS TO REACH ALMOST +19C BY THU. IT IS NOT UNTIL THAT SLOWLY WEAKENING TROF ARRIVES LATE IN THE WEAK THAT A DRIER..ZONAL..AND COOLER AIRMASS IS ALLOWED TO MOVE IN. DETAILS... MON NIGHT INTO WED... GRADUALLY WARMING TEMPERATURES THANKS TO SW FLOW IS EXPECTED...ALONG WITH INCREASING DWPTS...REACHING THE UPPER 60S BY WED. H85 TEMPS OF +16C TUE SUGGEST TEMPS IN THE MID 80S WHERE SUNSHINE ALLOWS FULL MIXING...WHILE +18C SUGGESTS SOME HIGHS AROUND 90F ON WED. THE KEY EACH OF THESE DAYS WILL BE THEIR CONVECTIVE POTENTIAL. EACH DAY THE H7 TEMPS INCREASE...TO ABOUT +8C ON TUE...THEN NEAR +10C BY WED...SUGGESTING A BUILDING CAPPING INVERSION. ALSO...RRQ OF THE UPPER JET AND SLACKENING IN THE MASS FIELDS REMAINS TO THE N AND W EACH DAY. THEREFORE...SUSPECT THAT THE BEST CHANCE FOR ACTIVITY IS TO THE N AND W. ALSO...SHEAR IS MINIMAL AT BEST /GENERALLY BELOW 15 KT/ SO ANY CONVECTIVE ACTIVITY THAT IS ABLE TO OCCUR WILL LIKELY COLLAPSE QUICKLY. IN SUM...WILL GO WITH SOME LOW POPS..MAINLY ACROSS THE W EACH DAY...WITH SLIGHTLY HIGHER POPS ON WED THANKS TO THE FACT THAT ALL OF THESE FEATURES LINE UP SLIGHTLY BETTER. OVERNIGHT...SOME FOG IS POSSIBLE...PARTICULARLY TUE NIGHT AND WED NIGHT. THU... BETTER CHANCE FOR CONVECTIVE ACTIVITY AS UPPER LVL JET STREAK LINES UP IT/S RRQ OVER SRN NEW ENGLAND...WITH SFC BASED CAPE VALUES 1000-1500J/KG. SHEAR MAGNITUDES ARE HIGHER AS WELL...ON THE ORDER OF 40 KT. ALL AS A SFC COLD FRONT PUSHES THROUGH THE AREA. WILL HIGHLIGHT CHANCE POPS WITH THE POSSIBILITY OF CONVECTION. ALTHOUGH A SEVERE THREAT IS THERE...HAVE HIGHEST CONFIDENCE IN HEAVY RAIN AS PWATS APPROACH 2.0 INCHES. WITH THE LATEST RUNS...WILL BEGIN TO BRING IN DRIER AIR BY THU EVENING. FRI INTO THE WEEKEND... WITH THE MORE PROGRESSIVE SOLUTION NOW FAVORED...THE SHORTWAVE TROF IS EXPECTED TO LIFT TO THE NE AS ONCE AGAIN...THE SW RIDGE REGAINS CONTROL. HOWEVER...DO EXPECT THAT SOME DRIER...COOLER AIR WILL MOVE IN WITH HIGH PRES MOVING OVER FROM THE W-NW. THEREFORE...EXPECT A RETURN TO LOWER HUMIDITIES AND NEAR SEASONABLE TEMPERATURES UNTIL SW FLOW RETURNS BY SUN. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY/...HIGH CONFIDENCE. TODAY...HIGH CONFIDENCE. VFR. ALTHOUGH PERIODIC -SHRA ARE POSSIBLE THROUGH THE LATE MORNING AND AFTERNOON MAINLY S AND E OF A PVD-BOS LINE...VFR SHOULD DOMINATE IN THIS AS WELL. WINDS GENERALLY E-NE THROUGH THE DAY EXCEPT MAINLY N IN THE CT VALLEY. TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...ALTHOUGH BETTER CHANCE FOR SOME OVERNIGHT FOG WITH MVFR/IF ESPECIALLY ACK/FMH/HYA/MVY. NOT CONFIDENT ENOUGH TO PUT IN TAF EXCEPT ACK WITH THIS UPDATE. NE FLOW CONTINUES. TOMORROW...HIGH CONFIDENCE. MAINLY VFR AFTER ANY FOG BURNS OFF IN THE MORNING. LIGHT NE FLOW FOR MOST OF THE DAY. SEA BREEZES LIKELY AGAIN ON COASTS. KBOS TAF...HIGH CONFIDENCE IN TAF. KBDL TAF...HIGH CONFIDENCE IN TAF. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY... MON NIGHT INTO WED...MODERATE CONFIDENCE. MAINLY VFR. HOWEVER OVERNIGHT EACH NIGHT...THE THREAT FOR FOG WITH IFR/MVFR CONDITIONS IS POSSIBLE...PARTICULARLY ALONG THE S COAST. ISOLATED SHOWER/T-STORM POSSIBLE WED AFTERNOON MAINLY IN THE W. WED NIGHT INTO THU...MODERATE CONFIDENCE. A COLD FRONT CROSSES THE REGION...WITH A BETTER CHANCE FOR MORE WIDESPREAD SHOWERS OR THUNDERSTORMS AND MVFR/IFR CONDITIONS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. THROUGH MONDAY...HIGH CONFIDENCE. WAVE MODELS CONTINUE TO OVERFORECAST WAVE HEIGHTS OFF OUR COAST BY ABOUT A FOOT. LOWERED THE WAVE HEIGHT GUIDANCE BY 20 PERCENT THROUGH MONDAY. TRANQUIL BOATING WEATHER CONTINUES WITH EASTERLY WINDS AROUND 5-15 KT. WINDS AND SEAS BELOW SMALL CRAFT ADVISORY LEVELS. WILL SEE A CHANCE OF SHOWERS ACROSS THE S/SE WATERS AND ADJACENT SHOWERS TODAY. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY... MON NIGHT THROUGH TUE...HIGH CONFIDENCE. HIGH PRES OVER THE WATERS SHOULD LEAD TO MAINLY QUIET BOATING WEATHER...WITH SW WINDS AND SEAS GENERALLY BELOW SMALL CRAFT ADVISORY THRESHOLDS. SOME FOG POSSIBLE BOTH MON AND TUE NIGHT WITH REDUCED VSBYS. WED AND THU...MODERATE CONFIDENCE. SW FLOW IS EXPECTED TO INCREASE WED AHEAD OF A COLD FRONT WHICH WILL CROSS THE WATERS EARLY THU. WINDS NEAR THE SE COAST OF MA MAY GUST TO AROUND 25 KT AT TIMES...POTENTIALLY REQUIRING A SMALL CRAFT ADVISORY. SEAS SHOULD REMAIN BELOW 5 FT THROUGH THE PERIOD HOWEVER. SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER THE WATERS PARTICULARLY LATE WED NIGHT AND THU. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...BELK/DOODY NEAR TERM...SIPPRELL SHORT TERM...BELK LONG TERM...DOODY AVIATION...BELK/DOODY MARINE...BELK/DOODY
AREA FORECAST DISCUSSION
NWS ALBANY NY
639 AM EDT SUN JUL 20 2014 .SYNOPSIS... A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR A FEW RAIN SHOWERS AND MOSTLY CLOUDY SKIES TODAY...MAINLY THIS MORNING. WARMER AND MORE HUMID CONDITIONS ARE EXPECTED DURING THE EARLY PORTION OF THE UPCOMING WEEK...BEFORE A COLD FRONT RETURNS MORE WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE REGION ON WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 638 AM EDT...A WEAK UPPER LEVEL SHORTWAVE IS MOVING ACROSS ONTARIO AND THE EASTERN GREAT LAKES. A VORTICITY MAX SWINGING AROUND THIS SHORTWAVE TROUGH HAS ALLOWED FOR SOME RAIN SHOWERS EARLY THIS MORNING FOR SOUTHERN AND EASTERN PORTIONS OF THE AREA. MOST OF THIS RAINFALL IS FALLING FROM A MID LEVEL CLOUD DECK...AND WITH DRY LOW LEVELS IN PLACE...MUCH OF THE RAINFALL IS EVAPORATING BEFORE REACHING THE GROUND. AS A RESULT...THE RADAR APPEARS MUCH MORE WORSE THAN WHAT IS ACTUALLY OCCURRING. STILL...WE WILL ALLOW FOR SLIGHT TO LOW CHC POPS THROUGH ABOUT 9 AM TO ACCOUNT FOR THIS ACTIVITY. THE 08Z 3KM HRRR SHOWS THIS ACTIVITY EXITING OUR EASTERN AREAS BY ABOUT MID MORNING. OUTSIDE THIS ACTIVITY...THERE COULD BE A BRIEF SHOWER CLOSER TO THE SHORTWAVE OVER THE ADIRONDACKS OR WESTERN MOHAWK VALLEY THIS AFTN...OTHERWISE MOST AREAS LOOK TO REMAIN DRY DURING THE DAY TODAY. IR SATELLITE IMAGERY SHOWS PLENTY OF CLOUDS AROUND THIS MORNING. THERE SHOULD BE SOME BREAKS OF SUN BY AFTERNOON AS THE TROUGH BEGINS TO WEAKEN...AS IT SHEARS OUT AND LIFTS INTO QUEBEC. WITH 850 HPA TEMPS AROUND 10-12 DEGREES C...AND MIXING OCCURRING TO ABOUT 825-850 HPA...MAX TEMPS SHOULD REACH THE UPPER 70S TO NEAR 80 FOR VALLEY AREAS. WITH DEWPOINTS STILL IN THE 50S...IT WON/T FEEL TOO HUMID OUT THERE EITHER...AND PWAT VALUES WILL CONTINUE TO RUN A LITTLE BELOW NORMAL FOR MID JULY...WITH READINGS AROUND 1.00 INCH. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... MAINLY DRY AND QUIET WEATHER WILL CONTINUE THROUGH THE SHORT TERM PERIOD. AS THE WEAK SHORTWAVE DEPARTS...THE UPPER LEVEL FLOW WILL BECOME ZONAL FOR MONDAY...WITH WEAK RIDGING STARTING TO BUILD IN BY TUESDAY. THE LOW LEVEL FLOW WILL BE OUT OF THE SOUTH...SO MOISTURE WILL GRADUALLY RETURN TO THE REGION...WITH HUMIDITY LEVELS STEADILY RISING OVER THE NEXT FEW DAYS. IN ADDITION...850 HPA TEMPS WILL WARM AS WELL...WITH +16 AT 850 HPA IN PLACE BY TUESDAY. AS A RESULT...MAX TEMPS LOOK TO REACH THE LOW 80S FOR VALLEY AREAS ON MONDAY...AND MID TO UPPER 80S ON TUESDAY. OVERNIGHT LOWS WILL BECOME WARMER EACH NIGHT...WITH 50S TONIGHT...LOW 60S FOR MON NIGHT...AND MID 60S FOR TUESDAY NIGHT. DEWPOINTS WILL BE BACK INTO THE UPPER 50S TO LOW 60S FOR MONDAY AND LOW TO MID 60S FOR TUESDAY. IT SHOULD BE FAIRLY DRY FOR MOST LOCATIONS OVER THE NEXT FEW DAYS DUE TO A LACK OF FORCING IN PLACE AND LIMITED MOISTURE. STILL...WE CANNOT TOTALLY RULE OUT A BRIEF SHOWER OR THUNDERSTORM THANKS TO DAYTIME HEATING DURING THE AFTN OR EVENING HOURS ON MON OR TUESDAY...MAINLY OVER THE HIGH TERRAIN. ANY SHOWER OR THUNDERSTORM WOULD BE BRIEF AND FAIRLY SPOTTY IN COVERAGE. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... A VERY WARM AND HUMID AIR MASS WILL BE ACROSS THE REGION FOR WEDNESDAY AS H850 TEMPS CLIMB TO NEAR 20C ALONG WITH A STRENGTHENING SOUTHWEST FLOW REGIME. FORECAST SURFACE DEWPOINTS ARE PROGGED TO BE WELL INTO THE 60S AND EVEN SOME LOWER 70S. THE APPARENT TEMPERATURE FORECAST /HEAT INDEX/ CLIMBS INTO THE MID 90S FOR VALLEY LOCATIONS WHICH IS BELOW ADVISORY LEVEL CRITERIA. OF MORE INTEREST WILL BE THE APPROACHING UPSTREAM COLD FRONT. AS MENTIONED IN PREVIOUS AFD/S FOR THIS TIME FRAME...WEDNESDAY INTO WEDNESDAY EVENING COULD PROVE TO BE RATHER ACTIVE WITH STRONG THUNDERSTORMS. BULK SHEAR VALUES CLIMB AT OR ABOVE 40KTS WITH FORECAST SBCAPES IN EXCESS OF 1K J/KG AS PWATS CLIMB AT OR ABOVE 1.75 INCHES. WE WILL RETAIN THE HIGH CHANCE POPS DURING THIS TIME FRAME AS GLOBAL MODELS STILL DIFFER WITH FROPA TIMING. THE NEXT CONCERN WILL THEN BE HOW QUICKLY THE FRONTAL BOUNDARY AND WAVE OF LOW PRESSURE THAT A COUPLE OF GLOBAL MODELS SUGGEST AND A FEW ENSEMBLE MEMBERS SUGGEST THAT SWEEP THROUGH THE REGION. THE GFS/GGEM REMAINS LAGGING THE FRONTAL PASSAGE WELL INTO THURSDAY DUE TO MULTIPLE SURFACES WAVES DEVELOPING ALONG THE FRONT AS IT SAGS SOUTHWARD. HOWEVER...THE ECMWF IS SHOWING MORE OF A PROGRESSIVE SOLUTION WITH HIGH PRESSURE RAPIDLY BUILDING IN FOR THURSDAY. WILL GO WITH A COMPROMISE FOR NOW AND MENTION CHANCE POPS FOR THURSDAY MORNING...BUT WILL DECREASE POPS BY AFTERNOON. TEMPERATURES WILL COOL BUT HUMIDITY LEVELS COULD STILL BE ELEVATED...ESPECIALLY IF THE GFS VERIFIES. MODELS ARE IN BETTER AGREEMENT FOR FRIDAY INTO SATURDAY. SURFACE HIGH PRESSURE IS EXPECTED TO BUILD IN FROM THE GREAT LAKES AND SOUTHEAST CANADA PROVIDING DRY CONDITIONS...HOWEVER...CYCLONIC FLOW ALOFT REMAINS. THIS SHOULD ALLOW FOR SEASONABLY WARM TEMPERATURES AND COMFORTABLE HUMIDITY LEVELS WITH DIURNALLY DRIVEN CLOUDS. THE GFS REMAINS THE MOST AGGRESSIVE WITH A STRONG PV ANOMALY DIVING SOUTHWARD TO BRING A SHOWER OR TWO ACROSS THE TERRAIN BUT ECMWF REMAINS LESS PRONOUNCED AS WE WILL KEEP POPS BELOW SLIGHT CHANCE THRESHOLDS. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... THE BATCH OF RAIN WAS QUICKLY EXITING THE BERKSHIRES LEAVING BEHIND A BKN VFR DECK. THIS WILL BE THE MAIN TREND FOR THE DAY WITH SCT-BKN MID AND HIGH LEVEL CLOUDS. WINDS WILL REMAIN RATHER LIGHT WITH A TENDENCY FROM THE SOUTHERLY DIRECTION. LATER TONIGHT...LIGHT WINDS AND SOME INCREASE IN LOWER LEVEL MOISTURE COULD BRING ABOUT SOME MIST/FOG. OUTLOOK... MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR A FEW RAIN SHOWERS TODAY...BUT COVERAGE WILL BE SPOTTY AND RAINFALL AMOUNTS WILL BE VERY LIGHT. AFTER A CLOUDY START...SOME SUN WILL BREAK OUT BY AFTERNOON WITH RH VALUES DROPPING TO AROUND 40 PERCENT WITH LIGHT S-SE WINDS AROUND 5 MPH. WINDS WILL BECOME NEARLY CALM TONIGHT WITH DEW FORMATION AND RH VALUES RETURNING TO 85-100 PERCENT IN MOST LOCATIONS. AN ISOLATED SHOWER IS POSSIBLE ON MONDAY AND TUESDAY...OTHERWISE A PARTLY CLOUDY SKY WILL BE IN PLACE WITH LIGHT SOUTHERLY WINDS AT 5-10 MPH. RH VALUES WILL DROP TO 40-50 PERCENT DURING THE AFTERNOON HOURS ON MONDAY AND AROUND 50 PERCENT ON TUESDAY AFTERNOON. && .HYDROLOGY... MAINLY DRY WEATHER IS EXPECTED THROUGH THE REMAINDER OF THE WEEKEND WITH JUST A LOW CHANCE FOR A BRIEF LIGHT RAIN SHOWER ACROSS PARTS OF THE AREA TODAY. AN ISOLATED SHOWER OR THUNDERSTORM CANNOT BE RULED OUT ON MONDAY OR TUESDAY EITHER...OTHERWISE DRY WEATHER LOOKS TO CONTINUE INTO FIRST PORTION OF THE UPCOMING WEEK. THERE WILL BE A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ON WEDNESDAY...AS A COLD FRONT APPROACHES THE AREA. WITH LITTLE OR NO RAINFALL...RIVER LEVELS WILL HOLD STEADY OR SLOWLY FALL OVER THE NEXT FEW DAYS. 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...FRUGIS NEAR TERM...FRUGIS SHORT TERM...FRUGIS LONG TERM...BGM/JPV AVIATION...BGM FIRE WEATHER...FRUGIS HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
348 AM EDT SUN JUL 20 2014 .SYNOPSIS... A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR A FEW RAIN SHOWERS AND MOSTLY CLOUDY SKIES TODAY...MAINLY THIS MORNING. WARMER AND MORE HUMID CONDITIONS ARE EXPECTED DURING THE EARLY PORTION OF THE UPCOMING WEEK...BEFORE A COLD FRONT RETURNS MORE WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE REGION ON WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 348 AM EDT...A WEAK UPPER LEVEL SHORTWAVE IS MOVING ACROSS ONTARIO AND THE EASTERN GREAT LAKES. A VORTICITY MAX SWINGING AROUND THIS SHORTWAVE TROUGH HAS ALLOWED FOR SOME RAIN SHOWERS EARLY THIS MORNING ACROSS THE CATSKILLS AND MID HUDSON VALLEY. MOST OF THIS RAINFALL IS FALLING FROM A MID LEVEL CLOUD DECK...AND WITH DRY LOW LEVELS IN PLACE...MUCH OF THE RAINFALL IS EVAPORATING BEFORE REACHING THE GROUND. AS A RESULT...THE RADAR APPEARS MUCH MORE WORSE THAN WHAT IS ACTUALLY OCCURRING. STILL...WE WILL ALLOW FOR SLIGHT TO LOW CHC POPS FOR SOUTHERN/EASTERN AREAS THROUGH ABOUT 9 AM TO ACCOUNT FOR THIS ACTIVITY. THE 05Z 3KM HRRR SHOWS THIS ACTIVITY EXITING OUR EASTERN AREAS BY ABOUT MID MORNING. OUTSIDE THIS ACTIVITY...THERE COULD BE A BRIEF SHOWER CLOSER TO THE SHORTWAVE OVER THE ADIRONDACKS OR WESTERN MOHAWK VALLEY THIS AFTN...OTHERWISE MOST AREAS LOOK TO REMAIN DRY DURING THE DAY TODAY. IR SATELLITE IMAGERY SHOWS PLENTY OF CLOUDS AROUND THIS MORNING. THERE SHOULD BE SOME BREAKS OF SUN BY AFTERNOON AS THE TROUGH BEGINS TO WEAKEN...AS IT SHEARS OUT AND LIFTS INTO QUEBEC. WITH 850 HPA TEMPS AROUND 10-12 DEGREES C...AND MIXING OCCURRING TO ABOUT 825-850 HPA...MAX TEMPS SHOULD REACH THE UPPER 70S TO NEAR 80 FOR VALLEY AREAS. WITH DEWPOINTS STILL IN THE 50S...IT WON/T FEEL TOO HUMID OUT THERE EITHER...AND PWAT VALUES WILL CONTINUE TO RUN A LITTLE BELOW NORMAL FOR MID JULY...WITH READINGS AROUND 1.00 INCH. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... MAINLY DRY AND QUIET WEATHER WILL CONTINUE THROUGH THE SHORT TERM PERIOD. AS THE WEAK SHORTWAVE DEPARTS...THE UPPER LEVEL FLOW WILL BECOME ZONAL FOR MONDAY...WITH WEAK RIDGING STARTING TO BUILD IN BY TUESDAY. THE LOW LEVEL FLOW WILL BE OUT OF THE SOUTH...SO MOISTURE WILL GRADUALLY RETURN TO THE REGION...WITH HUMIDITY LEVELS STEADILY RISING OVER THE NEXT FEW DAYS. IN ADDITION...850 HPA TEMPS WILL WARM AS WELL...WITH +16 AT 850 HPA IN PLACE BY TUESDAY. AS A RESULT...MAX TEMPS LOOK TO REACH THE LOW 80S FOR VALLEY AREAS ON MONDAY...AND MID TO UPPER 80S ON TUESDAY. OVERNIGHT LOWS WILL BECOME WARMER EACH NIGHT...WITH 50S TONIGHT...LOW 60S FOR MON NIGHT...AND MID 60S FOR TUESDAY NIGHT. DEWPOINTS WILL BE BACK INTO THE UPPER 50S TO LOW 60S FOR MONDAY AND LOW TO MID 60S FOR TUESDAY. IT SHOULD BE FAIRLY DRY FOR MOST LOCATIONS OVER THE NEXT FEW DAYS DUE TO A LACK OF FORCING IN PLACE AND LIMITED MOISTURE. STILL...WE CANNOT TOTALLY RULE OUT A BRIEF SHOWER OR THUNDERSTORM THANKS TO DAYTIME HEATING DURING THE AFTN OR EVENING HOURS ON MON OR TUESDAY...MAINLY OVER THE HIGH TERRAIN. ANY SHOWER OR THUNDERSTORM WOULD BE BRIEF AND FAIRLY SPOTTY IN COVERAGE. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... A VERY WARM AND HUMID AIR MASS WILL BE ACROSS THE REGION FOR WEDNESDAY AS H850 TEMPS CLIMB TO NEAR 20C ALONG WITH A STRENGTHENING SOUTHWEST FLOW REGIME. FORECAST SURFACE DEWPOINTS ARE PROGGED TO BE WELL INTO THE 60S AND EVEN SOME LOWER 70S. THE APPARENT TEMPERATURE FORECAST /HEAT INDEX/ CLIMBS INTO THE MID 90S FOR VALLEY LOCATIONS WHICH IS BELOW ADVISORY LEVEL CRITERIA. OF MORE INTEREST WILL BE THE APPROACHING UPSTREAM COLD FRONT. AS MENTIONED IN PREVIOUS AFD/S FOR THIS TIME FRAME...WEDNESDAY INTO WEDNESDAY EVENING COULD PROVE TO BE RATHER ACTIVE WITH STRONG THUNDERSTORMS. BULK SHEAR VALUES CLIMB AT OR ABOVE 40KTS WITH FORECAST SBCAPES IN EXCESS OF 1K J/KG AS PWATS CLIMB AT OR ABOVE 1.75 INCHES. WE WILL RETAIN THE HIGH CHANCE POPS DURING THIS TIME FRAME AS GLOBAL MODELS STILL DIFFER WITH FROPA TIMING. THE NEXT CONCERN WILL THEN BE HOW QUICKLY THE FRONTAL BOUNDARY AND WAVE OF LOW PRESSURE THAT A COUPLE OF GLOBAL MODELS SUGGEST AND A FEW ENSEMBLE MEMBERS SUGGEST THAT SWEEP THROUGH THE REGION. THE GFS/GGEM REMAINS LAGGING THE FRONTAL PASSAGE WELL INTO THURSDAY DUE TO MULTIPLE SURFACES WAVES DEVELOPING ALONG THE FRONT AS IT SAGS SOUTHWARD. HOWEVER...THE ECMWF IS SHOWING MORE OF A PROGRESSIVE SOLUTION WITH HIGH PRESSURE RAPIDLY BUILDING IN FOR THURSDAY. WILL GO WITH A COMPROMISE FOR NOW AND MENTION CHANCE POPS FOR THURSDAY MORNING...BUT WILL DECREASE POPS BY AFTERNOON. TEMPERATURES WILL COOL BUT HUMIDITY LEVELS COULD STILL BE ELEVATED...ESPECIALLY IF THE GFS VERIFIES. MODELS ARE IN BETTER AGREEMENT FOR FRIDAY INTO SATURDAY. SURFACE HIGH PRESSURE IS EXPECTED TO BUILD IN FROM THE GREAT LAKES AND SOUTHEAST CANADA PROVIDING DRY CONDITIONS...HOWEVER...CYCLONIC FLOW ALOFT REMAINS. THIS SHOULD ALLOW FOR SEASONABLY WARM TEMPERATURES AND COMFORTABLE HUMIDITY LEVELS WITH DIURNALLY DRIVEN CLOUDS. THE GFS REMAINS THE MOST AGGRESSIVE WITH A STRONG PV ANOMALY DIVING SOUTHWARD TO BRING A SHOWER OR TWO ACROSS THE TERRAIN BUT ECMWF REMAINS LESS PRONOUNCED AS WE WILL KEEP POPS BELOW SLIGHT CHANCE THRESHOLDS. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... A SOLID MVFR CIG WAS ACROSS THE REGION AS UPSTREAM RADAR MOSAIC REVEALS A BATCH OF RAIN TRACKING NORTHEAST FROM PA. GIVEN THE EXTRAPOLATION OF THIS RAIN...WE WILL PLACE A TEMPO GROUP FOR KPOU-KPSF AND WATCH TRENDS. MEANWHILE...THE CHANCE FOR FOG FORMATION AS KGFL AND KPSF /WITH OR WITHOUT RAIN/ REMAINS IN THE FORECAST AS BRIEF MVFR VIS THRESHOLDS HAVE ALREADY BEEN OBSERVED. IMPROVEMENTS ARE EXPECTED WITH DAYLIGHT TO VFR CONDITIONS FOR THE DAY. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT...BECOMING SOUTHEASTERLY AROUND 5 KT DURING THE DAYLIGHT HOURS SUNDAY. OUTLOOK... MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR A FEW RAIN SHOWERS TODAY...BUT COVERAGE WILL BE SPOTTY AND RAINFALL AMOUNTS WILL BE VERY LIGHT. AFTER A CLOUDY START...SOME SUN WILL BREAK OUT BY AFTERNOON WITH RH VALUES DROPPING TO AROUND 40 PERCENT WITH LIGHT S-SE WINDS AROUND 5 MPH. WINDS WILL BECOME NEARLY CALM TONIGHT WITH DEW FORMATION AND RH VALUES RETURNING TO 85-100 PERCENT IN MOST LOCATIONS. AN ISOLATED SHOWER IS POSSIBLE ON MONDAY AND TUESDAY...OTHERWISE A PARTLY CLOUDY SKY WILL BE IN PLACE WITH LIGHT SOUTHERLY WINDS AT 5-10 MPH. RH VALUES WILL DROP TO 40-50 PERCENT DURING THE AFTERNOON HOURS ON MONDAY AND AROUND 50 PERCENT ON TUESDAY AFTERNOON. && .HYDROLOGY... MAINLY DRY WEATHER IS EXPECTED THROUGH THE REMAINDER OF THE WEEKEND WITH JUST A LOW CHANCE FOR A BRIEF LIGHT RAIN SHOWER ACROSS PARTS OF THE AREA TODAY. AN ISOLATED SHOWER OR THUNDERSTORM CANNOT BE RULED OUT ON MONDAY OR TUESDAY EITHER...OTHERWISE DRY WEATHER LOOKS TO CONTINUE INTO FIRST PORTION OF THE UPCOMING WEEK. THERE WILL BE A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ON WEDNESDAY...AS A COLD FRONT APPROACHES THE AREA. WITH LITTLE OR NO RAINFALL...RIVER LEVELS WILL HOLD STEADY OR SLOWLY FALL OVER THE NEXT FEW DAYS. 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...FRUGIS NEAR TERM...FRUGIS SHORT TERM...FRUGIS LONG TERM...BGM/JPV AVIATION...BGM FIRE WEATHER...FRUGIS HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
159 AM EDT SUN JUL 20 2014 .PREV DISCUSSION... /ISSUED 812 PM EDT SAT JUL 19 2014/ UPDATE... WARM FRONT SITUATED ACROSS CENTRAL GA THIS EVENING. SCATTERED SHOWERS AND ISOLD THUNDERSTORMS CONTINUE ACROSS THE REGION. THE LATEST HRRR AND THE 18Z NAM DO HAVE THE PRECIP COVERAGE DECREASING OVER THE NEXT FEW HOURS AND HAVE UPDATED POPS TO REFLECT THE CURRENT TRENDS. THUNDER HAS BEEN LIMITED...BUT EVEN THE SHOWERS HAVE BEEN PRODUCING LOCALLY HEAVY RAINFALL. HAVE ONLY MADE MINOR CHANGES TO THE HOURLY TEMP/DEWPOINT GRIDS. WINDS HAVE ALREADY SWITCHED AROUND TO THE EAST ACROSS NORTHERN PORTIONS OF THE CWFA...AND THE MODELS HAVENT HANDLED THIS TREND WELL...ESPECIALLY ACROSS THE METRO. THE EAST WINDS WILL CONTINUE ACROSS THE NORTHERN HALF OF THE CWFA...WITH SOUTH WINDS ACROSS THE SOUTHERN CWFA. PREV DISCUSSION... /ISSUED 726 PM EDT SAT JUL 19 2014/ PREV DISCUSSION... /ISSUED 343 PM EDT SAT JUL 19 2014/ SHORT TERM /TODAY THROUGH MONDAY/... MODELS AGREE ON A WET PATTERN CONTINUING THROUGH THE SHORT TERM. A SATELLITE WATER VAPOR LOOP SHOWS A BROAD UPPER TROUGH EXTENDING FROM THE GREAT LAKES REGION SOUTHWARD TO THE NORTH CENTRAL GULF REGION. MODELS CONTINUE SHOW A SERIES OF DISTURBANCES TRAVERSING THE TROUGH AND EVENTUALLY CUTTING OFF AN UPPER LOW OVER THE SOUTHEAST STATES SOMETIME SUNDAY NIGHT. CURRENTLY A DISTURBANCE IS NOTED PUSHING ACROSS CENTRAL GA AND SPARKING WIDESPREAD SHOWERS WITH SCATTERED EMBEDDED THUNDERSTORMS... MAINLY ALONG AND SOUTH OF A LA GRANGE TO ATHENS LINE... WITH MAINLY SPOTTY SHOWERS NORTH OF THAT LINE. SURFACE ANALYSIS SHOWS LOW PRESSURE OVER WEST TN WITH A WARM FRONT NEAR A RMG TO ATL TO AGS LINE... AND A WEAK WEDGE OF HIGH PRESSURE TRYING TO NOSE IN FROM THE NE. AT THIS TIME... IT APPEARS THE WARM SECTOR IS WINNING THE BATTLE AND CREEPING NORTHWARD. BEGINNING TO SEE A FEW BREAKS IN THE LOW CLOUDS ACROSS THE WARM SECTOR... YET STILL EXPECT MOST AREAS TO CONTINUE SHOWING BROKEN MID AND HIGH CLOUDS. CLOUDY CONDITIONS WILL PERSIST AND EVEN LOWER AGAIN TONIGHT ACROSS MUCH OF THE AREA AS THE COOL WEDGE TRIES TO NOSE BACK IN OVERNIGHT. THE COMBINATION OF WEAK DISTURBANCES AND A MOIST TROPICAL AIR MASS WITH 1.8+ PW`S WILL SUPPORT A CHANCE OF SHOWERS OVERNIGHT. THINK THE CURRENT THUNDERSTORM THREAT ACROSS MAINLY CENTRAL GA WILL GREATLY DIMINISH BY 9 PM THIS EVENING WITH LOSS OF DAYTIME HEATING. MODELS SHOW THE SURFACE LOW REMAINING BLOCKED OVER AL ON SUNDAY AS THE UPPER TROUGH DEEPENS TO THE WEST. THIS SUGGESTS EVEN A GREATER CHANCE FOR THUNDERSTORMS FOR SUNDAY AFTERNOON WHILE THE WARM FRONT MEANDERS ACROSS PARTS OF NORTH AND CENTRAL GA DURING MAX HEATING. ALTHOUGH CAPE AND SHEAR VALUES ARE MARGINAL ON SUNDAY... INCREASING UPPER SUPPORT DURING MAX HEATING AND A BOUNDARY IN THE AREA ALL SUGGEST THE POTENTIAL FOR A FEW STRONG STORMS SUNDAY AFTERNOON. HOWEVER... THINK THE MAIN THREAT WILL BE LOCALLY HEAVY RAIN AND THE POTENTIAL FOR ISOLATED BRIEF FLOODING OR PONDING OF WATER ACROSS FLOOD PRONE LOW AREAS. SPC IS SHOWING ONLY A GENERAL THUNDER OUTLOOK FOR THE AREA THROUGH SUNDAY NIGHT. THE THUNDERSTORM THREAT ON SUNDAY SHOULD ALSO DIMINISH BY 9-10 PM SUNDAY EVENING...WITH A CHANCE OF SHOWERS CONTINUING SUNDAY NIGHT. AS FOR TEMPS...AMPLE CLOUDS AND RAIN POTENTIAL HAS WARRANTED LEANING TOWARD THE COOLER SIDE OF GUIDANCE FOR HIGHS... AND WARMER LOWS. A MAV AND MET BLEND WITH SOME TWEAKS LOOKED REASONABLE FOR NOW. 39 LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... NO CHANGES MADE IN THE EXTENDED FORECAST. THE EXTENDED BEGINS WITH THE SHORTWAVE DAMPING AND BEGINNING TO LIFT OUT...BUT WITH MOIST TROPICAL CONNECTION STILL IN PLACE WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE OFF AND ON. THE GENERAL UPPER WEAKNESS REMAINS IN PLACE THROUGH MIDWEEK...WHEN THE UPPER RIDGE OVER THE DESERT SOUTHWEST TRIES TO PUSH EAST. ANOTHER SHORTWAVE DIPPING INTO THE GREAT LAKES IMPEDES THE PROGRESS OF THE HIGH BUT ALSO DRAGS ANOTHER SURFACE FRONT THROUGH THE OHIO VALLEY WEDNESDAY NIGHT INTO THURSDAY. GFS AND ECMWF DIVERGE FROM THERE WITH THE GFS BRINGING THE FRONT ALL THE WAY THROUGH ON FRIDAY WITH A MUCH SHARPER UPPER TROUGH...AND THE ECMWF STALLING THE FRONT ACROSS THE SOUTHEAST AS FLOW ALOFT FLATTENS. HAVE TRIED TO TAKE A GENERAL COMPROMISE BUT DID START TO REDUCE POPS TOWARD THE END OF THE PERIOD. IN THE MEANTIME HOWEVER...HIGH CHANCE TO LIKELY POPS REMAIN ESPECIALLY IN THE AFTERNOON WITH DIURNAL ENHANCEMENT OF CONVECTION. WITH MODERATE CAPE VALUES CANNOT RULE OUT PULSE-LIKE STRONG TO BRIEF SEVERE IN THE AFTERNOONS BUT NOTHING WIDESPREAD. LOCALLY HEAVY RAIN LOOKS TO BE THE LARGER THREAT WITH PRECIPITABLE WATER VALUES AT OR JUST ABOVE 2 INCHES. AT THIS TIME...BECAUSE THE QPF WILL BE FAIRLY SPREAD OUT THROUGH THE EXTENDED...NOT REALLY CONCERNED ABOUT FLOODING ISSUES AT THIS POINT OTHER THAN LOCALIZED AREAS UNDER INDIVIDUAL STORMS. TEMPERATURES THROUGH THE EXTENDED SHOULD GENERALLY BE SLIGHTLY BELOW SEASONAL NORMALS DUE TO THE INCREASED AFTERNOON CLOUD COVER AND CONVECTION. 01 && .AVIATION... 06Z UPDATE... EASTERLY FLOW WILL CONTINUE AND WITH SATURATED GROUNDS FROM YESTERDAY...EXPECT LIFR/IFR TO SPREAD WESTWARD AND CONTINUE THROUGH 12-14Z. ISOLATED SHOWERS THROUGH 16Z WILL INCREASE IN COVERAGE AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON...CONFIDENCE IN THUNDER AT A TAF SITE IS TOO LOW TO INCLUDE MORE THAN A PROB30 AT THIS TIME. //ATL CONFIDENCE...06Z UPDATE... MEDIUM TO HIGH CONFIDENCE ON WINDS. MEDIUM CONFIDENCE ON VISIBILITY/CIGS. LOW CONFIDENCE ON WEATHER. ATWELL && .PRELIMINARY POINT TEMPS/POPS... ATHENS 85 71 87 70 / 50 40 40 40 ATLANTA 83 70 86 71 / 60 30 30 30 BLAIRSVILLE 79 65 81 65 / 50 30 30 30 CARTERSVILLE 84 69 87 70 / 50 20 20 30 COLUMBUS 86 72 90 72 / 60 30 30 30 GAINESVILLE 83 71 85 69 / 50 40 30 30 MACON 85 70 86 72 / 60 40 40 40 ROME 84 70 88 70 / 40 20 20 30 PEACHTREE CITY 84 69 87 71 / 60 30 30 30 VIDALIA 87 72 88 72 / 60 50 50 40 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ATWELL LONG TERM....31 AVIATION...ATWELL
AREA FORECAST DISCUSSION
NWS BOISE ID
255 PM MDT SUN JUL 20 2014 .SHORT TERM...TONIGHT THROUGH TUESDAY...INCREASING CLOUDS THIS AFTERNOON AS THE MONSOONAL MOISTURE HAS REACHED SOUTHERN IDAHO THIS AFTERNOON. PRESENTLY STORMS ARE FIRING ACROSS CENTRAL NEVADA AND NORTHERN CALIFORNIA. SHOWERS AND ISOLATED THUNDERSTORMS WILL INCREASE IN COVERAGE LATER THIS EVENING AS A VIGOROUS SHORTWAVE MOVES NORTHEASTWARD THROUGH THE FORECAST AREA INTO MONDAY. MODEL SOUNDINGS SHOW LARGE DCAPE VALUES AND THE HRRR MODEL IS SHOWING POSSIBILITY FOR GUSTS TO 40KT WITH THUNDERSTORM OUTFLOWS LATE THIS AFTERNOON AND EVENING. PRECIPITABLE WATER VALUES INCREASE TO NEAR ONE INCH BY MONDAY MORNING. EXPECT SHOWERS AND TEMPERATURES AROUND 5 DEGREES BELOW NORMAL FOR MONDAY. WIDESPREAD CLOUDINESS WILL ALSO LIMIT THE CONVECTIVE PARAMETERS AND THUS HAVE ONLY MENTION OF ISOLATED THUNDERSTORMS MONDAY. TUESDAY AFTERNOON LOOKS BETTER FOR THUNDERSTORM DEVELOPMENT AS THERE ARE BETTER DYNAMICS ALOFT WITH BULK SHEAR VALUES APPROACHING 40KT AND LESS CLOUDINESS TO HELP AID SURFACE HEATING. .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...MOIST SOUTHWESTERLY FLOW AHEAD OF AN APPROACHING UPPER LEVEL TROUGH ALONG WITH AN UPPER LEVEL JET MOVING OVER THE REGION WILL BRING SHOWERS AND THUNDERSTORMS OVER THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY. THE BEST CHANCE FOR THESE SHOWERS AND THUNDERSTORMS WILL BE TUESDAY EVENING...THEN DECREASING FROM SOUTHWEST TO NORTHEAST LATE TUESDAY NIGHT THROUGH WEDNESDAY. WEDNESDAY NIGHT THE UPPER LEVEL THROUGH AND ASSOCIATED LOW WILL MOVE EAST ALONG THE CANADIAN BORDER WITH FLOW ALOFT SHIFTING TO THE WEST OVER THE FORECAST AREA. WILL SEE A SLIGHT CHANCE OF PRECIPITATION OVER NORTHERN ZONES WEDNESDAY NIGHT BUT THEN DRY CONDITIONS UNDER THE WESTERLY FLOW THROUGH THE WEEKEND. WEDNESDAY TEMPERATURES WILL BE NEAR NORMAL BUT AS THE UPPER LEVEL TROUGH MOVES TO THE EAST WILL SEE TEMPERATURES ON THURSDAY AROUND 10 DEGREES BELOW NORMAL. TEMPERATURES WILL THEN WARM BACK TO NEAR NORMAL FRIDAY AND WARM TO 5 TO 7 DEGREES ABOVE NORMAL BY SUNDAY. && .AVIATION...HAZY CONDITIONS WITH LOCAL MVFR VISIBILITY DUE TO SMOKE FROM WILDFIRES. MID LEVEL CEILINGS ALONG THE NEVADA BORDER THIS EVENING WILL CONTINUE TO SPREAD TO THE NORTH TONIGHT. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG THE NEVADA BORDER THIS EVENING AND SPREAD NORTH DURING THE NIGHT. SURFACE WINDS WILL BE SOUTHWEST TO WEST AROUND 10 KNOTS THIS EVENING...BECOMING LIGHT AFTER SUNSET. GUSTY WINDS TO NEAR 40 KNOTS NEAR THUNDERSTORMS. WINDS ALOFT WILL BE SOUTHWEST TO WEST AROUND 15 KNOTS UP THROUGH 10K FEET MSL. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING IDZ401. OR...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING ORZ646. && $$ WEATHER.GOV/BOISE SHORT TERM...KA LONG TERM....JA/WH AVIATION.....JA
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1221 PM CDT Sun Jul 20 2014 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 340 AM CDT SUN JUL 20 2014 This morning water vapor satellite shows a weak wave moving across north central Kansas at 08Z. A band of clouds developed across Dickinson, Clay and Washington Counties in area of isentropic lift in the 305K-310K layer and on the nose of moisture advection in the 850mb-700mb layer. Stratus further west across northwest Kansas and south central and western Nebraska low stratus clouds continued to expand, mainly across Nebraska, as the low level jet veers to the southwest. Today and tonight will see a transition from northwest flow aloft as a ridge builds in from the west. The wave is not expected to develop showers as it moves east as atmosphere is dry. Expect the clouds to expand some and spread east through sunrise. Forecast soundings from the RAP indicates that the clouds should breakup/dissipate during the mid to late morning hours. Temperatures will be on the rise today as 850mb temperatures increase into the lower to middle 20s Celsius. Forecast soundings show that these temperatures should mix down from around 850 mb yielding highs in the upper 80s east to the middle 90s north central. South winds today will increase into the 10 to 20 mph range by afternoon with gusts of 20 to 25mph. Tonight, moisture will continue to increase across north central and northeast Kansas. Soundings show that winds should stay up overnight keeping the lower boundary layer mixed. Have maintained mild overnight temperatures in the lower to middle 70s. With the upper ridge building over Kansas this will keep any precipitation to the north of the forecast area. .LONG TERM...(Monday through Saturday) Issued at 340 AM CDT SUN JUL 20 2014 Monday and Tuesday periods still looking quite warm as the upper ridge continues to build north and east into the central portions of the CONUS and south to southwest winds persist ahead of a cold front. Specifics of just how warm and humid surface conditions will be remain somewhat uncertain with models differing on low level thermal profiles in terms of how deep mixing will be and how warm the above-surface airmass will be to mix into. Other complicating factors include well-agreed upon cirrus in Mexico coming northeast and into the area Monday and still small chances for elevated convection to develop ahead of the front in increasingly moist though still not very saturated mid level parcels. Even if precip fails to develop, could at least see some mid cloud into much of Tuesday before the front arrives in the afternoon. At this point, have leaned closer to the GFS soundings with mixing not as deep as the NAM suggests and 850-925mb temp fields warmer than then ECMWF. Dewpoints still support heat index values several degrees above air temps for steadily increasing likelihood of Heat Advisory levels being reached for mainly northern and central sections. Better and more significant thunderstorm chances come with the front`s passage late Tuesday afternoon and evening. CAPE near the boundary likely to be around 2000 J/kg but limited shear and high cloud bases should limit severe potential to mainly multicell-produced downburst winds. Boundary exits Wednesday morning for a somewhat cooler though higher relatively humid airmass as moisture pools behind the front, though Thursday looking a bit more comfortable as northeast winds persist. Still appears to be at least minor convective chances as the front pushes back northeast Thursday night into Friday, with another cold front likely moving south into Kansas around Saturday. Models vary with just how this may happen, but the upper ridge appears to again break down with shortwaves dropping southeast from central Canada. Highs Friday could again near triple digits. && .AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon) Issued at 1219 PM CDT SUN JUL 20 2014 Expect VFR conditions and south winds through the TAF period. Gusts 20-25 kts possible this afternoon and again late Monday morning. Will have a LLJ around 35 kts at 2000 ft AGL tonight, but winds around 10 kts at surface suggest that LLWS group will not be needed. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...53 LONG TERM...65 AVIATION...Barjenbruch
AREA FORECAST DISCUSSION
NWS TOPEKA KS
622 AM CDT Sun Jul 20 2014 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 340 AM CDT SUN JUL 20 2014 This morning water vapor satellite shows a weak wave moving across north central Kansas at 08Z. A band of clouds developed across Dickinson, Clay and Washington Counties in area of isentropic lift in the 305K-310K layer and on the nose of moisture advection in the 850mb-700mb layer. Stratus further west across northwest Kansas and south central and western Nebraska low stratus clouds continued to expand, mainly across Nebraska, as the low level jet veers to the southwest. Today and tonight will see a transition from northwest flow aloft as a ridge builds in from the west. The wave is not expected to develop showers as it moves east as atmosphere is dry. Expect the clouds to expand some and spread east through sunrise. Forecast soundings from the RAP indicates that the clouds should breakup/dissipate during the mid to late morning hours. Temperatures will be on the rise today as 850mb temperatures increase into the lower to middle 20s Celsius. Forecast soundings show that these temperatures should mix down from around 850 mb yielding highs in the upper 80s east to the middle 90s north central. South winds today will increase into the 10 to 20 mph range by afternoon with gusts of 20 to 25mph. Tonight, moisture will continue to increase across north central and northeast Kansas. Soundings show that winds should stay up overnight keeping the lower boundary layer mixed. Have maintained mild overnight temperatures in the lower to middle 70s. With the upper ridge building over Kansas this will keep any precipitation to the north of the forecast area. .LONG TERM...(Monday through Saturday) Issued at 340 AM CDT SUN JUL 20 2014 Monday and Tuesday periods still looking quite warm as the upper ridge continues to build north and east into the central portions of the CONUS and south to southwest winds persist ahead of a cold front. Specifics of just how warm and humid surface conditions will be remain somewhat uncertain with models differing on low level thermal profiles in terms of how deep mixing will be and how warm the above-surface airmass will be to mix into. Other complicating factors include well-agreed upon cirrus in Mexico coming northeast and into the area Monday and still small chances for elevated convection to develop ahead of the front in increasingly moist though still not very saturated mid level parcels. Even if precip fails to develop, could at least see some mid cloud into much of Tuesday before the front arrives in the afternoon. At this point, have leaned closer to the GFS soundings with mixing not as deep as the NAM suggests and 850-925mb temp fields warmer than then ECMWF. Dewpoints still support heat index values several degrees above air temps for steadily increasing likelihood of Heat Advisory levels being reached for mainly northern and central sections. Better and more significant thunderstorm chances come with the front`s passage late Tuesday afternoon and evening. CAPE near the boundary likely to be around 2000 J/kg but limited shear and high cloud bases should limit severe potential to mainly multicell-produced downburst winds. Boundary exits Wednesday morning for a somewhat cooler though higher relatively humid airmass as moisture pools behind the front, though Thursday looking a bit more comfortable as northeast winds persist. Still appears to be at least minor convective chances as the front pushes back northeast Thursday night into Friday, with another cold front likely moving south into Kansas around Saturday. Models vary with just how this may happen, but the upper ridge appears to again break down with shortwaves dropping southeast from central Canada. Highs Friday could again near triple digits. && .AVIATION...(For the 12Z TAFs through 12Z Monday Morning) Issued at 622 AM CDT SUN JUL 20 2014 VFR Conditions are expected through the period. South winds increase to around 13kts with gusts near 22 kts after 15Z. Winds drop off to less than 10 kts after 01Z. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...53 LONG TERM...65 AVIATION...53
AREA FORECAST DISCUSSION
NWS TOPEKA KS
340 AM CDT Sun Jul 20 2014 .SHORT TERM...(Today and Tonight) Issued at 340 AM CDT SUN JUL 20 2014 This morning water vapor satellite shows a weak wave moving across north central Kansas at 08Z. A band of clouds developed across Dickinson, Clay and Washington Counties in area of isentropic lift in the 305K-310K layer and on the nose of moisture advection in the 850mb-700mb layer. Stratus further west across northwest Kansas and south central and western Nebraska low stratus clouds continued to expand, mainly across Nebraska, as the low level jet veers to the southwest. Today and tonight will see a transition from northwest flow aloft as a ridge builds in from the west. The wave is not expected to develop showers as it moves east as atmosphere is dry. Expect the clouds to expand some and spread east through sunrise. Forecast soundings from the RAP indicates that the clouds should breakup/dissipate during the mid to late morning hours. Temperatures will be on the rise today as 850mb temperatures increase into the lower to middle 20s Celsius. Forecast soundings show that these temperatures should mix down from around 850 mb yielding highs in the upper 80s east to the middle 90s north central. South winds today will increase into the 10 to 20 mph range by afternoon with gusts of 20 to 25mph. Tonight, moisture will continue to increase across north central and northeast Kansas. Soundings show that winds should stay up overnight keeping the lower boundary layer mixed. Have maintained mild overnight temperatures in the lower to middle 70s. With the upper ridge building over Kansas this will keep any precipitation to the north of the forecast area. .LONG TERM...(Monday through Saturday) Issued at 340 AM CDT SUN JUL 20 2014 Monday and Tuesday periods still looking quite warm as the upper ridge continues to build north and east into the central portions of the CONUS and south to southwest winds persist ahead of a cold front. Specifics of just how warm and humid surface conditions will be remain somewhat uncertain with models differing on low level thermal profiles in terms of how deep mixing will be and how warm the above-surface airmass will be to mix into. Other complicating factors include well-agreed upon cirrus in Mexico coming northeast and into the area Monday and still small chances for elevated convection to develop ahead of the front in increasingly moist though still not very saturated mid level parcels. Even if precip fails to develop, could at least see some mid cloud into much of Tuesday before the front arrives in the afternoon. At this point, have leaned closer to the GFS soundings with mixing not as deep as the NAM suggests and 850-925mb temp fields warmer than then ECMWF. Dewpoints still support heat index values several degrees above air temps for steadily increasing likelihood of Heat Advisory levels being reached for mainly northern and central sections. Better and more significant thunderstorm chances come with the front`s passage late Tuesday afternoon and evening. CAPE near the boundary likely to be around 2000 J/kg but limited shear and high cloud bases should limit severe potential to mainly multicell-produced downburst winds. Boundary exits Wednesday morning for a somewhat cooler though higher relatively humid airmass as moisture pools behind the front, though Thursday looking a bit more comfortable as northeast winds persist. Still appears to be at least minor convective chances as the front pushes back northeast Thursday night into Friday, with another cold front likely moving south into Kansas around Saturday. Models vary with just how this may happen, but the upper ridge appears to again break down with shortwaves dropping southeast from central Canada. Highs Friday could again near triple digits. && .AVIATION...(For the 06Z TAFs through 06Z Sunday Night) Issued at 1138 PM CDT SAT JUL 19 2014 Vfr conditions will continue through this period as well with good mixing overnight that will keep fog potential very low in the terminal locations. South winds will steadily increase beyond 14z at all sites with gusts 20 to 22 kts through 00z/20 before decreasing to 7-8 kts aft 01z/21. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...53 LONG TERM...65 AVIATION...63
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1147 PM MDT SAT JUL 19 2014 .UPDATE... ISSUED AT 527 PM MDT SAT JUL 19 2014 WILL BE ISSUING UPDATE TO FINE TUNE COVERAGE BASED ON CURRENT CONDITIONS AND LATEST SHORT RANGE GUIDANCE (HRRR/RAP). CIN REMAINS HIGH OVER MOST OF THE CWA...THOUGH THERE APPEARS TO BE WEAKENING OVER EASTERN COLORADO IN PROXIMITY OF THE SURFACE TROUGH AND A DRYLINE OVER SE COLORADO. THESE FEATURES SHOULD SHIFT EAST THROUGH THE EVENING AND ACT AS FOCUS FOR BETTER COVERAGE. LAST FEW RUNS OF THE HRRR SHOW THUNDERSTORMS MOVING OFF CHEYENNE RIDGE AND INCREASING IN COVERAGE ACROSS OUR NORTHERN CWA AS THETA-E ADVECTION INCREASING WITH NOCTURNAL JET AHEAD OF SURFACE TROUGH. THE MOST FAVORABLE SUPPORT TRANSITIONS QUICKLY EASTWARD 03-09Z...AND SO FAR ACTIVITY HAS NOT MADE SIGNIFICANT PROGRESS IN COVERAGE IN NORTHERN COLORADO. I LEFT SLIGHT CHANCE POPS IN PLACE FURTHER NORTH LINGERING THROUGH 08Z...BUT CONFIDENCE IS LOW AND BEST COVERAGE STILL LOOKS LIKE IT WILL BE SOUTH OF INTERSTATE 70. I ALSO ADDED A MENTION OF PATCHY FOG IN THE 10-14Z PERIOD SUNDAY MORNING IN THE NORTHEAST WHERE HIGHER TD VALUES AND LIGHT WINDS MAY SUPPORT FOG DEVELOPMENT IMMEDIATELY AHEAD OF THE SURFACE TROUGH AXIS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 200 PM MDT SAT JUL 19 2014 NORTHWEST FLOW WILL CONTINUE TONIGHT ACROSS THE HIGH PLAINS. THE RIDGE BUILDS EAST OF THE ROCKIES ON SUNDAY. A SURFACE TROUGH WILL RESIDE OVER EASTERN COLORADO DURING THIS TIME. A SHORTWAVE CURRENTLY IN WYOMING WILL MOVE INTO THE FA BY THIS EVENING AND WILL INITIATE CONVECTION NEAR THE SURFACE TROUGH IN EASTERN COLORADO. STEERING WIND AT 10 TO 15KTS WILL BRING THE STORMS FROM EASTERN COLORADO INTO NORTHWEST KANSAS. CAPE VALUES FROM 1000 TO 2000J/KG WILL COMBINE WITH SHEAR OF 30KTS MAKING IT POSSIBLE FOR A FEW STORMS TO BECOME SEVERE WITH LARGE HAIL AND DAMAGING WIND. PRECIPITABLE WATER VALUES UP TO AN INCH WILL BE FAVORABLE FOR LOCALLY HEAVY RAINFALL THIS EVENING. THE HRRR FOCUS THE BEST CHANCES OVER THE SOUTHWEST FA FOR THUNDERSTORMS THIS EVENING. CONVECTIVE INHIBITION VALUES RISE TO AROUND 100 BY 03Z SO WILL RESTRICT STORMS TO THE EVENING WITH DRY CONDITIONS OVERNIGHT. SUBSIDENCE WILL CONTINUE SUNDAY MORNING AND INTO THE AFTERNOON ACROSS THE FA. EXPECT DRY CONDITIONS SUNDAY. SOME FORCING WILL BE AVAILABLE OVER EASTERN COLORADO IN THE AFTERNOON SO WILL INCLUDE A SLIGHT CHANCE THERE. CAPE VALUES ARE EXTREMELY LOW WITH AROUND 200J/KG AND SHEAR VALUES ARE 15 TO 20KTS SO DO NOT EXPECT SEVERE WEATHER SUNDAY AFTERNOON. MIN TEMPERATURES TONIGHT WILL COOL TO THE MID 60S. MAX TEMPERATURES SUNDAY SHOULD WARM UP MORE QUICKLY THAN TODAY WITH A LACK OF STRATUS AROUND. MAX TEMPERATURES SHOULD RISE TO THE UPPER 90S IN EASTERN COLORADO WITH 100 DEGREES ELSEWHERE ACROSS THE FA WITH UP TO 102 AT HLC. HEAT ADVISORY CRITERIA ARE FORECAST TO BE MET SUNDAY AFTERNOON IN THE EASTERN FA. PLAN TO ISSUE A HEAT ADVISORY FOR THOSE ZONES. (SEE DETAILS BELOW). .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 235 PM MDT SAT JUL 19 2014 SUNDAY NIGHT-TUESDAY...UPPER HIGH CENTERED OVER CENTRAL/SOUTHERN NEW MEXICO AT THE BEGINNING OF THE PERIOD IS FORECAST TO SLOWLY STRENGTHEN WHILE DRIFTING INTO CENTRAL COLORADO BY 00Z WEDNESDAY. FOR MONDAY 850MB TEMPERATURES SUPPORT HIGHS IN THE MID 90S TO AROUND 100 IN FAR EASTERN COLORADO WITH 100-105 EAST OF THE CO/KS BORDER. THE COMBINATION OF TEMPERATURE AND HUMIDITY SUPPORTS HEAT INDICES AROUND 105 FOR RED WILLOW...DECATUR...SHERIDAN...GRAHAM AND NORTON COUNTIES FROM 20Z-00Z. ON TUESDAY LITTLE CHANGE FROM MONDAYS TEMPERATURES...COULD SEE SLIGHTLY COOLER OR LESS HOT CONDITIONS ACROSS THE NORTHWEST HALF OF THE AREA BEHIND A SFC TROUGH WHILE SIMILAR READINGS TO MONDAY (100-105) EXPECTED EAST OF THE TROUGH. WE DO REACH HEAT INDEX VALUES AROUND 105 ACROSS THE SAME COUNTIES AS MONDAY BUT FOR NOW WILL HOLD OFF AND TAKE ANOTHER LOOK TOMORROW. LOW TEMPERATURES SUNDAY NIGHT AND MONDAY NIGHT UPPER 50S TO MID 60S IN FAR EASTERN COLORADO...MID 60S TO LOW 70S EAST OF THE STATE LINE. WARMEST READINGS IN GRAHAM AND NORTON COUNTIES. AS FAR AS PRECIPITATION CHANCES...NAM/GFS/ECMWF ARE SHOWING AN AREA OF 700-300MB MOISTURE AIDED BY UPPER JET MAX ROTATING AROUND THE UPPER HIGH AND INTO THE AREA SUNDAY NIGHT THROUGH MONDAY WITH DRIER AIR MOVING IN MONDAY NIGHT. WILL CONTINUE WITH MAINLY AFTERNOON AND EVENING CHANCES FOR THUNDERSTORMS. ON TUESDAY FAVORABLE MOISTURE IS CAUGHT IN BETWEEN NORTHEAST WINDS ACROSS THE NORTHERN HALF OF THE AREA WITH SOUTHERN WINDS ACROSS THE SOUTH. PLENTY OF HEATING TO WORK WITH THE MOISTURE AND LOW LEVEL FORCING TO PROVIDE SOME SHOWERS AND THUNDERSTORMS DESPITE 700MB TEMPERATURES IN THE 16C-18C RANGE. TUESDAY NIGHT-SATURDAY...500MB HEIGHTS CONTINUE TO SLOWLY RISE THROUGH WEDNESDAY AS CENTER OF UPPER RIDGE COVERS THE AREA. FOR THURSDAY THROUGH SATURDAY THE UPPER RIDGE MOVES SOUTH A BIT TOWARD SOUTHERN COLORADO/NORTHERN NEW MEXICO WHILE ALSO DE-AMPLIFYING AS LOW PRESSURE MOVES ALONG THE US/CANADIAN BORDER. HIGH TEMPERATURES WILL REMAIN ABOVE NORMAL WELL INTO THE 90S WITH POSSIBLY A FEW 100S. LOWS GENERALLY IN THE 60S TO LOW 70S. LOOKING AT PRECIPITATION CHANCES...MAY HAVE SOME LINGERING THUNDERSTORMS EARLY TUESDAY NIGHT AS WIND CONVERGENT LINE REMAINS NEARLY STATIONARY. LOW LEVEL JET FEEDS INTO THE CONVERGENT AREA AND ELEVATED INHIBITION IS RATHER LOW. ATMOSPHERE BECOMES RATHER UNSTABLE WEDNESDAY AFTERNOON WITH OVER 3K J/KG CAPE ALONG WIND SHIFT LINE FROM TRENTON TO HILL CITY. AS WAS THE CASE YESTERDAY ECMWF/GFS SHOW A SLUG OF 700-300MB MOISTURE EMERGING OFF THE COLORADO FRONT RANGE NORTH OF THE PALMER DIVIDE AT THE END OF THE DAY ROUNDING THE RIDGE AXIS INTO OUR AREA WEDNESDAY NIGHT. GFS UPPER JET DIVERGENT SIGNATURE SUGGESTING THE POSSIBILITY OF A SMALL CLUSTER OF STORMS MOVING THROUGH. SHOULD SEE A LULL IN PRECIPITATION CHANCES DURING THE DAY THURSDAY AS BETTER MOISTURE/INSTABILITY AND LIFT ARE TO OUR WEST. 700MB TEMPERATURES ARE ALSO 17C-19C PRETTY MUCH CAPPING ANY POTENTIAL. 700-300MB MOISTURE AXIS TO OUR WEST DURING THE DAY MOVES INTO THE AREA THURSDAY NIGHT BUT IT APPEARS ATMOSPHERE LIKELY CAPPED PREVENTING ANY DEVELOPMENT FROM OCCURRING. FRIDAY-SATURDAY...ONCE AGAIN PLUME OF 700-300MB MOISTURE MOVES INTO OR IS IN THE AREA AND WHEN COMBINED WITH AFTERNOON HEATING CREATE A CHANCE FOR AFTERNOON AND EVENING THUNDERSTORMS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1146 PM MDT SAT JUL 19 2014 SURFACE LOW OVER EASTERN COLORADO IS EXPECTED TO SHIFT EAST TONIGHT WITH LOW LEVELS EXPECTED TO DRY OUT FROM THE WEST. DEPENDING ON TIMING/POSITION OF THIS LOW WE COULD SEE ANOTHER NIGHT OF FOG/STRATUS DEVELOPMENT AT EITHER TERMINAL. CURRENT SHORT RANGE GUIDANCE KEEPS BEST FOG/STRATUS CHANCES EAST OF KGLD...SO HAVE LEFT ANY MENTION OUT OF KGLD TAF. KMCK SHOULD REMAIN WITHIN THE VERY MOIST AIR MASS EAST OF THE SURFACE LOW...AND SHORT RANGE GUIDANCE ALONG WITH NAM IS FAVORING LOW STRATUS/FOG AROUND 12Z. I WAS NOT CONFIDENT ENOUGH TO GO AS LOW AS THE NAM (1/4SM) AND COVERAGE STILL SEEMS LIKE IT WILL LIKELY BE PATCHY WITH KMCK RIGHT ON THE EDGE OF BETTER BL MOISTURE. I INTRODUCED A TEMPO IFR GROUP DURING THIS ISSUANCE. WINDS SHOULD GENERALLY REMAIN OUT OF THE SOUTH AROUND 11KT THROUGH MOST OF THE TAF PERIOD (WITH A PERIOD OF VARIABLE WINDS ALONG TROUGH AXIS MORNING AND MIDDAY)...EVENTUALLY SHIFT TO THE WEST/NORTHWEST. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...HEAT ADVISORY FROM 3 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR KSZ003-004-015-016. HEAT ADVISORY FROM 3 PM TO 7 PM CDT MONDAY FOR KSZ003-004-015- 016. CO...NONE. NE...HEAT ADVISORY FROM 3 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR NEZ081. HEAT ADVISORY FROM 3 PM TO 7 PM CDT MONDAY FOR NEZ081. && $$ UPDATE...DR SHORT TERM...FS LONG TERM...99 AVIATION...DR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
322 PM EDT SUN JUL 20 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFF THE CANADIAN MARITIMES THROUGH MONDAY. MEANWHILE...A FRONTAL BOUNDARY REMAINS OFF THE CAROLINA COAST THROUGH EARLY IN THE UPCOMING WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... TYPICALLY HOTTEST TIME OF YR...BUT WX PAST FEW DAYS ANYTHING LIKE THAT. CLDNS RMNS EXTENSIVE OVR THE FA...W/ ISOLD/SCT SHRAS MOVING THROUGH PORTIONS OF SE VA/INTERIOR NE NC. OVERALL PATTERN RMNS UNCHANGED...W/ WK SFC HI PRES INVOF ERN NEW ENG...TROUGH OFF THE MDATLC/SE CST AND WK SFC LO PRES INVOF CNTRL GULF STATES. LO LVL FLO LARGELY HAS E COMPONENT. RUC SHIFTS CURRENT AREA OF SHRAS TO THE E AND OFFSHORE WHILE DISSIPATING THROUGH EARLY THIS EVE. OTRW...CONTD VRB CLDS/MCLDY. POPS WILL MNLY STAY BLO 30% (OUTSIDE OF PORTIONS OF SE VA/NE NC). MODERATELY HUMID OVRNGT...RMNG MCLDY W/ POPS AOB 20% THROUGHOUT. LO TEMPS FM THE M60S TO ARND 70F. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... STUCK IN AN UNSETTLED/MURKY PATTERN SFC-ALOFT THROUGH TUE. ONE PIECE OF UPR TROUGH EXITS CANADIAN MARITIME THROUGH TUE...W/ TRAILING PIECE LINGERING INVOF ERN GULF STATES. MEANWHILE...STRONG RIDGE RMNS ANCHORED FM THE PLAINS THROUGH THE ROCKIES. AT THE SFC...HI PRES TO RMN SITUATED FM NRN MDATLC TO CANADIAN MARITIMES...W/ WK TROUGH FOUND E OF THE CAROLINA CST. DYNAMICS/FORCING FOR PCPN RMNS WK THE NEXT FEW DAYS...AS LO LVL FLO CONTS MNLY FM THE OCN. XPCG VRB CLDS TO PCLDY WX THROUGH THE PD...W/ ONLY MARGINAL INCRS IN DEWPTS WHILE (DAYTIME) TEMPS ARE HELD DOWN TO OR BLO SEASONAL NORMALS. BULK OF POPS WILL RMN AOB 30%...AND MNLY FAVOR AREAS INLAND/SRN PORTIONS EACH DAY. BY WED...NEXT TROUGH ALOFT TRACKS THROUGH THE GREAT LAKES AND GRADUALLY AMPLIFIES INTO THE NE/MDATLC RGNS ON WED...PUSHING THE NEXT SFC CDFNT TWD THE FA (BY LT WED). LO LVL FLO BECOMES MORE SSW ON WED...RESULTING IN BETTER OPPORTUNITY FOR PSNY CONDS AND TEMPS RESPONDING BACK TO OR SLGTLY ABV SEASONAL NORMALS. POPS TO RMN 20-30% ON WED. HI TEMPS IN THE L/M80S MON...M/U80S TUE...U80S TO L90S WED. NIGHTTIME LO TEMPS FM THE U60S TO M70S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A COLD FRONT IS FORECAST TO MOVE INTO THE REGION FROM THE NW LATE THURSDAY...BEFORE DROPPING SOUTH INTO THE CAROLINAS ON FRIDAY. INCREASED TSTM CHANCES ARE EXPECTED THURSDAY (ESPECIALLY AFTN) DUE TO THE APPROACH OF THE FRONT. WILL CARRY SOLID CHC POPS (30-50%)...HIGHEST WEST. ASSUMING THE COLD FRONT IS ABLE TO PUSH SOUTH OF THE AREA ON FRIDAY...BEST PCPN CHANCES WOULD BE LIMITED TO SOUTHERN AREAS CLOSET TO THE FRONT. THERE IS SOME INDICATION FROM THE GFS/ECMWF THAT NORTHERN AREAS COULD BE DRY ON FRIDAY...BUT NOT QUITE READY TO COMPLETELY BITE ON THAT IDEA GIVEN THE TOUGHNESS OF FRONTS TO PUSH SOUTH OF THE LOCAL AREA THIS TIME OF YEAR. WILL MAINTAIN SLIGHT CHC POPS ACROSS THE NORTH...WITH SOLID CHC POPS ACROSS SOUTHERN AREAS. WILL CARRY SOME LOW END 20-30% POPS AREA-WIDE NEXT WEEKEND FOR TYPICAL DIURNAL SUMMERTIME CONVECTION. HIGHS THURS IN THE UPR 80S TO LOW 90S. HIGHS FRI-SUN IN THE 80S. LOWS THRU THE PERIOD IN THE 60S TO LOW 70S. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... LOW PRESSURE A COUPLE HUNDRED MILES EAST OF THE VA EASTERN SHORE IS GRADUALLY PULLING AWAY PER VIS SATLLITE IMAGERY. THIS FEATURE HAS HELPED MAINTAIN SOLID IFR/MVFR CLOUD DECK ACROSS THE DELMARVA. THESE CLOUDS LOOK TO PERSIST THROUGH 00Z. LOW LVL FLOW CONTINUES TO BE FROM THE NE/E THROUGH TAF PERIOD...WITH INCREASING POTENTIAL FOR MVFR/IFR CEILINGS AS SOME TERMINALS. 12Z GUIDANCE ALL POINTING TO A RETURN OF IFR CEILINGS AND POSSIBLE VSBY AT KSBY AFTER 03Z...AND HAVE CHANGED TAF IN THIS DIRECTION. HWVR...HAVE NOT GONE AS PESSIMISTIC AS NAM. GUIDANCE ALSO POINTING TO IFR OVERNIGHT AT KRIC...AND TSECTIONS SUGGEST LO LVL MOISTURE DEEPENS OVERNIGHT. HWVR...FOR NOW WILL KEEP CONDITIONS JUST ABOVE IFR...AS GUIDANCE...ESPECIALLY NAM...CAN BE TO AGGRESSIVE. ELSEWHERE...MVFR FORECAST OVERNIGHT...WITH VFR EXPECTED AFTER 12Z-13Z MONDAY. NOTE: OBSERVATIONS FROM SBY ARE NOT READILY AVAILABLE...TECHNICIANS ARE AWARE OF THE PROBLEM. INCLUDED AMD NOT SKED FOR NOW. && .MARINE... INVERTED TROF/SFC BOUNDARY WILL REMAIN JUST OFF THE COAST INTO EARLY TUES. THIS WILL RESULT IN CONTINUED NE OR E WINDS 15 KT OR LESS ACROSS THE WATERS. LOW PRESSURE MOVING NORTHWARD ALONG THE OFFSHORE BOUNDARY HAS INCREASED THE LOW-LEVEL FLOW JUST ENOUGH OFF THE LOWER MD EASTERN SHORE TO BUILD SEAS ABOVE 5 FT. SEA ARE EXPECTED TO REMAIN ELEVATED THROUGH SUNSET...BEFORE SUBSIDING AS THE LOW-LEVEL FLOW DECREASES. AS SUCH...WILL LEAVE SCA FOR HAZARDOUS SEAS IN PLACE NORTH OF CHINCOTEAGUE THROUGH 7 PM. OTW...SEAS 2 TO 4 FT. THE BOUNDARY WILL WASH OUT EARLY TUE...WITH HIGH PRESSURE BUILDING OFF THE MID ATLC/SE COAST FOR THE REMAINDER OF TUE INTO THU. WINDS WILL TURN FROM THE SE TO THE SW TUES NIGHT. A COLD FRONT WILL PUSH INTO THE WATERS FROM THE NW LATE THURS/THURS NGT...VEERING WINDS TO THE N-NE ON FRIDAY. SCA CONDITIONS ARE NOT EXPECTED ATTM. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 7 PM EDT THIS EVENING FOR ANZ650. && $$ SYNOPSIS...ALB/LKB NEAR TERM...ALB/LKB SHORT TERM...ALB/LKB LONG TERM...JDM AVIATION...WRS MARINE...JDM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
320 PM EDT SUN JUL 20 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFF THE CANADIAN MARITIMES THROUGH MONDAY. MEANWHILE...A FRONTAL BOUNDARY REMAINS OFF THE CAROLINA COAST THROUGH EARLY IN THE UPCOMING WEEK. && .NEAR TERM /THROUGH TONIGHT/... TYPICALLY HOTTEST TIME OF YR...BUT WX PAST FEW DAYS ANYTHING LIKE THAT. CLDNS RMNS EXTENSIVE OVR THE FA...W/ ISOLD/SCT SHRAS MOVING THROUGH PORTIONS OF SE VA/INTERIOR NE NC. OVERALL PATTERN RMNS UNCHANGED...W/ WK SFC HI PRES INVOF ERN NEW ENG...TROUGH OFF THE MDATLC/SE CST AND WK SFC LO PRES INVOF CNTRL GULF STATES. LO LVL FLO LARGELY FM THE NNE. RUC SHIFTS CURRENT AREA OF SHRAS TO THE E AND OFFSHORE WHILE DISSIPATING THROUGH EARLY THIS EVE. OTRW...CONTD VRB CLDS/MCLDY. POPS WILL MNLY STAY BLO 30% (OUTSIDE OF PORTIONS OF SE VA/NE NC). MODERATELY HUMID OVRNGT...RMNG MCLDY W/ POPS AOB 20% THROUGHOUT. LO TEMPS FM THE M60S TO ARND 70F. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... STUCK IN AN UNSETTLED/MURKY PATTERN SFC-ALOFT THROUGH TUE. ONE PIECE OF UPR TROUGH EXITS CANADIAN MARITIME THROUGH TUE...W/ TRAILING PIECE LINGERING INVOF ERN GULF STATES. MEANWHILE...STRONG RIDGE RMNS ANCHORED FM THE PLAINS THROUGH THE ROCKIES. AT THE SFC...HI PRES TO RMN SITUATED FM NRN MDATLC TO CANADIAN MARITIMES...W/ WK TROUGH FOUND E OF THE CAROLINA CST. DYNAMICS/FORCING FOR PCPN RMNS WK THE NEXT FEW DAYS...AS LO LVL FLO CONTS MNLY FM THE OCN. XPCG VRB CLDS TO PCLDY WX THROUGH THE PD...W/ ONLY MARGINAL INCRS IN DEWPTS WHILE (DAYTIME) TEMPS ARE HELD DOWN TO OR BLO SEASONAL NORMALS. BULK OF POPS WILL RMN AOB 30%...AND MNLY FAVOR AREAS INLAND/SRN PORTIONS EACH DAY. BY WED...NEXT TROUGH ALOFT TRACKS THROUGH THE GREAT LAKES AND GRADUALLY AMPLIFIES INTO THE NE/MDATLC RGNS ON WED...PUSHING THE NEXT SFC CDFNT TWD THE FA (BY LT WED). LO LVL FLO BECOMES MORE SSW ON WED...RESULTING IN BETTER OPPORTUNITY FOR PSNY CONDS AND TEMPS RESPONDING BACK TO OR SLGTLY ABV SEASONAL NORMALS. POPS TO RMN 20-30% ON WED. HI TEMPS IN THE L/M80S MON...M/U80S TUE...U80S TO L90S WED. NIGHTTIME LO TEMPS FM THE U60S TO M70S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A COLD FRONT IS FORECAST TO MOVE INTO THE REGION FROM THE NW LATE THURSDAY...BEFORE DROPPING SOUTH INTO THE CAROLINAS ON FRIDAY. INCREASED TSTM CHANCES ARE EXPECTED THURSDAY (ESPECIALLY AFTN) DUE TO THE APPROACH OF THE FRONT. WILL CARRY SOLID CHC POPS (30-50%)...HIGHEST WEST. ASSUMING THE COLD FRONT IS ABLE TO PUSH SOUTH OF THE AREA ON FRIDAY...BEST PCPN CHANCES WOULD BE LIMITED TO SOUTHERN AREAS CLOSET TO THE FRONT. THERE IS SOME INDICATION FROM THE GFS/ECMWF THAT NORTHERN AREAS COULD BE DRY ON FRIDAY...BUT NOT QUITE READY TO COMPLETELY BITE ON THAT IDEA GIVEN THE TOUGHNESS OF FRONTS TO PUSH SOUTH OF THE LOCAL AREA THIS TIME OF YEAR. WILL MAINTAIN SLIGHT CHC POPS ACROSS THE NORTH...WITH SOLID CHC POPS ACROSS SOUTHERN AREAS. WILL CARRY SOME LOW END 20-30% POPS AREA-WIDE NEXT WEEKEND FOR TYPICAL DIURNAL SUMMERTIME CONVECTION. HIGHS THURS IN THE UPR 80S TO LOW 90S. HIGHS FRI-SUN IN THE 80S. LOWS THRU THE PERIOD IN THE 60S TO LOW 70S. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... LOW PRESSURE A COUPLE HUNDRED MILES EAST OF THE VA EASTERN SHORE IS GRADUALLY PULLING AWAY PER VIS SATLLITE IMAGERY. THIS FEATURE HAS HELPED MAINTAIN SOLID IFR/MVFR CLOUD DECK ACROSS THE DELMARVA. THESE CLOUDS LOOK TO PERSIST THROUGH 00Z. LOW LVL FLOW CONTINUES TO BE FROM THE NE/E THROUGH TAF PERIOD...WITH INCREASING POTENTIAL FOR MVFR/IFR CEILINGS AS SOME TERMINALS. 12Z GUIDANCE ALL POINTING TO A RETURN OF IFR CEILINGS AND POSSIBLE VSBY AT KSBY AFTER 03Z...AND HAVE CHANGED TAF IN THIS DIRECTION. HWVR...HAVE NOT GONE AS PESSIMISTIC AS NAM. GUIDANCE ALSO POINTING TO IFR OVERNIGHT AT KRIC...AND TSECTIONS SUGGEST LO LVL MOISTURE DEEPENS OVERNIGHT. HWVR...FOR NOW WILL KEEP CONDITIONS JUST ABOVE IFR...AS GUIDANCE...ESPECIALLY NAM...CAN BE TO AGGRESSIVE. ELSEWHERE...MVFR FORECAST OVERNIGHT...WITH VFR EXPECTED AFTER 12Z-13Z MONDAY. NOTE: OBSERVATIONS FROM SBY ARE NOT READILY AVAILABLE...TECHNICIANS ARE AWARE OF THE PROBLEM. INCLUDED AMD NOT SKED FOR NOW. && .MARINE... INVERTED TROF/SFC BOUNDARY WILL REMAIN JUST OFF THE COAST INTO EARLY TUES. THIS WILL RESULT IN CONTINUED NE OR E WINDS 15 KT OR LESS ACROSS THE WATERS. LOW PRESSURE MOVING NORTHWARD ALONG THE OFFSHORE BOUNDARY HAS INCREASED THE LOW-LEVEL FLOW JUST ENOUGH OFF THE LOWER MD EASTERN SHORE TO BUILD SEAS ABOVE 5 FT. SEA ARE EXPECTED TO REMAIN ELEVATED THROUGH SUNSET...BEFORE SUBSIDING AS THE LOW-LEVEL FLOW DECREASES. AS SUCH...WILL LEAVE SCA FOR HAZARDOUS SEAS IN PLACE NORTH OF CHINCOTEAGUE THROUGH 7 PM. OTW...SEAS 2 TO 4 FT. THE BOUNDARY WILL WASH OUT EARLY TUE...WITH HIGH PRESSURE BUILDING OFF THE MID ATLC/SE COAST FOR THE REMAINDER OF TUE INTO THU. WINDS WILL TURN FROM THE SE TO THE SW TUES NIGHT. A COLD FRONT WILL PUSH INTO THE WATERS FROM THE NW LATE THURS/THURS NGT...VEERING WINDS TO THE N-NE ON FRIDAY. SCA CONDITIONS ARE NOT EXPECTED ATTM. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 7 PM EDT THIS EVENING FOR ANZ650. && $$ SYNOPSIS...ALB/LKB NEAR TERM...ALB/LKB SHORT TERM...ALB/LKB LONG TERM...JDM AVIATION...WRS MARINE...JDM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
135 PM EDT SUN JUL 20 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFF THE CANADIAN MARITIMES THROUGH MONDAY. MEANWHILE...A FRONTAL BOUNDARY REMAINS OFF THE CAROLINA COAST THROUGH EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CLDNS RMNS EXTENSIVE OVR THE FA...W/ SCT SHRAS MOVING THROUGH PORTIONS OF SCNTRL VA/INTERIOR NE NC. OVERALL PATTERN RMNS UNCHANGED...W/ WK SFC HI PRES INVOF ERN NEW ENG...TROUGH OFF THE MDATLC/SE CST AND WK SFC LO PRES INVOF CNTRL GULF STATES. LO LVL FLO FM THE NNE...AND ALG W/ THE CLDS WILL KEEP TEMPS BLO SEASONAL NORMALS ONCE AGN. RUC SHIFTS CURRENT AREA OF SHRAS TO THE E WHILE DISSIPATING NEXT FEW HRS. WILL HAVE VRB CLDS/PCLDY THROUGH THE REST OF THE DAY...W/ LMTD FORCING (AT BEST)...POPS WILL LARGELY STAY BLO 20-30%. HI TEMPS FM THE U70S TO M80S. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... FOR TONIGHT...NAM/GFS IN GOOD AGREEMENT THAT THE BROAD UPPER TROUGH OVER THE ERN CONUS AMPLIFIES FROM THE LOWER OH/TN VALLEY DOWN TO THE GULF COAST. THIS WILL GENLY ALLOW THE SFC LOW ACRS THE TN VALLEY/GULF COAST STATES TO SPREAD INCREASING DEEP MOISTURE EASTWARD AND CLOSER TO THE SE/MID ATLC REGION. SOME INDICATION THAT THE UPPER FLOW BECOMES SPLIT WHICH COULD KEEP MOST OF THE MOISTURE TO OUR SOUTH...SO WILL STILL KEEP POPS IN CHC RANGE OVERNIGHT AND BEYOND. MOSTLY CLOUDY WITH LOWS GENLY IN THE MID- UPPER 60S TO LOWER 70S WITH INCREASING HUMIDITY LEVELS. STUCK IN AN UNSETTLED PATTERN SFC-ALOFT THROUGH EARLY NEXT WK. ONE PIECE OF UPR TROUGH EXITS NEW ENG THROUGH TUE...W/ TRAILING PIECE LINGERING INVOF ERN GULF STATES. MEANWHILE...STRONG RIDGE RMNS ANCHORED FM THE PLAINS THROUGH THE ROCKIES. AT THE SFC...HI PRES TO RMN SITUATED FM NRN MDATLC TO CANADIAN MARITIMES...W/ WK TROUGH FOUND E OF THE CAROLINA CST. DYNAMICS/FORCING FOR PCPN RMNS WK THE NEXT FEW DAYS...AS LO LVL FLO CONTS MNLY FM THE OCN. XPCG VRB CLDS TO PCLDY WX THROUGH THE PD...W/ A CONTD/GRADUAL INCRS IN DEWPTS WHILE (DAYTIME) TEMPS ARE HELD DOWN TO OR BLO SEASONAL NORMALS. BULK OF POPS WILL RMN AOB 30%...AND MNLY FAVOR AREAS INLAND/SRN PORTIONS EACH DAY. HI TEMPS IN THE L/M80S MON...M/U80S TUE. NIGHTTIME LO TEMPS FM THE 60S TO L70S. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... BERMUDA HIGH PRESSURE WILL BECOME THE MORE DOMINANT WX FEATURE AROUND BY THE MIDDLE OF THE COMING WEEK...WITH INCREASING HEAT AND HUMIDITY MORE TYPICAL OF LATE JULY. A COLD FRONT IS FORECAST TO MOVE INTO THE REGION FROM THE NW LATE THURSDAY...BEFORE DROPPING SOUTH INTO THE CAROLINAS LATE IN THE WEEK. TYPICAL DIURNAL TSTM CHANCES ARE EXPECTED WED/THURS WITH INCREASED MOISTURE AND INSTABILITY. TSTM CHANCES SHOULD BE A LITTLE HIGHER THURSDAY DUE TO THE APPROACH OF THE FRONT. ASSUMING THE COLD FRONT IS ABLE TO PUSH SOUTH OF THE AREA ON FRIDAY...ANY PCPN CHANCES WOULD BE LIMITED TO SOUTHERN AREA CLOSET TO THE FRONT WITH HIGH PRESSURE BUILDING IN ACROSS THE NORTH THRU NEXT SATURDAY. HIGHS WED/THURS IN THE UPR 80S TO LOW 90S. HIGHS FRI/SAT IN THE 80S. LOWS THRU THE PERIOD IN THE 60S TO LOW 70S. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... LOW PRESSURE A COUPLE HUNDRED MILES EAST OF THE VA EASTERN SHORE IS GRADUALLY PULLING AWAY PER VIS SATLLITE IMAGERY. THIS FEATURE HAS HELPED MAINTAIN SOLID IFR/MVFR CLOUD DECK ACROSS THE DELMARVA. THESE CLOUDS LOOK TO PERSIST THROUGH 00Z. LOW LVL FLOW CONTINUES TO BE FROM THE NE/E THROUGH TAF PERIOD...WITH INCREASING POTENTIAL FOR MVFR/IFR CEILINGS AS SOME TERMINALS. 12Z GUIDANCE ALL POINTING TO A RETURN OF IFR CEILINGS AND POSSIBLE VSBY AT KSBY AFTER 03Z...AND HAVE CHANGED TAF IN THIS DIRECTION. HWVR...HAVE NOT GONE AS PESSIMISTIC AS NAM. GUIDANCE ALSO POINTING TO IFR OVERNIGHT AT KRIC...AND TSECTIONS SUGGEST LO LVL MOISTURE DEEPENS OVERNIGHT. HWVR...FOR NOW WILL KEEP CONDITIONS JUST ABOVE IFR...AS GUIDANCE...ESPECIALLY NAM...CAN BE TO AGGRESSIVE. ELSEWHERE...MVFR FORECAST OVERNIGHT...WITH VFR EXPECTED AFTER 12Z-13Z MONDAY. NOTE: OBSERVATIONS FROM SBY ARE NOT READILY AVAILABLE...TECHNICIANS ARE AWARE OF THE PROBLEM. INCLUDED AMD NOT SKED FOR NOW. && .MARINE... ...UPDATE...ISSUED SCA UNTIL 00Z FOR HAZARDOUS SEAS...ESPECIALLY BEYOND 10 NM...AS BUOY 44009 HAS BEEN AOA 5 FEET SINCE SUNRISE. EXPECT SEAS TO SUBSIDE THIS EVENING...AS LO LVL FLOW WEAKENS. INVERTED TROF/SFC BOUNDARY WILL REMAIN JUST OFF THE CST TODAY INTO EARLY TUE. THIS WILL RESULT IN A CONTINUED NE OR E WINDS 15 KT OR LESS ACRS THE WTRS. WAVES WILL RANGE FM 1 TO 3 FT OVR THE RIVERS/CHES BAY/CURRITUCK SND...WHILE SEAS WILL BE 2 TO 4 FT. THAT BOUNDARY WILL WASH OUT EARLY TUE...WITH HI PRES BLDNG OFF THE MID ATLC/SE CST FOR THE REMAINDER OF TUE INTO THU. WINDS WILL TURN FM THE SE TO THE SW DURING THIS TIME. A COLD FRONT WILL PUSH INTO THE WTRS FM THE WNW LATE THU/THU NGT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 7 PM EDT THIS EVENING FOR ANZ650. && $$ SYNOPSIS...ALB/LKB NEAR TERM...ALB/LKB SHORT TERM...ALB/LKB LONG TERM...JDM AVIATION...WRS MARINE...TMG
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1110 AM EDT SUN JUL 20 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFF THE CANADIAN MARITIMES THROUGH MONDAY. MEANWHILE...A FRONTAL BOUNDARY REMAINS OFF THE CAROLINA COAST THROUGH EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CLDNS RMNS EXTENSIVE OVR THE FA...W/ SCT SHRAS MOVING THROUGH PORTIONS OF SCNTRL VA/INTERIOR NE NC. OVERALL PATTERN RMNS UNCHANGED...W/ WK SFC HI PRES INVOF ERN NEW ENG...TROUGH OFF THE MDATLC/SE CST AND WK SFC LO PRES INVOF CNTRL GULF STATES. LO LVL FLO FM THE NNE...AND ALG W/ THE CLDS WILL KEEP TEMPS BLO SEASONAL NORMALS ONCE AGN. RUC SHIFTS CURRENT AREA OF SHRAS TO THE E WHILE DISSIPATING NEXT FEW HRS. WILL HAVE VRB CLDS/PCLDY THROUGH THE REST OF THE DAY...W/ LMTD FORCING (AT BEST)...POPS WILL LARGELY STAY BLO 20-30%. HI TEMPS FM THE U70S TO M80S. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... FOR TONIGHT...NAM/GFS IN GOOD AGREEMENT THAT THE BROAD UPPER TROUGH OVER THE ERN CONUS AMPLIFIES FROM THE LOWER OH/TN VALLEY DOWN TO THE GULF COAST. THIS WILL GENLY ALLOW THE SFC LOW ACRS THE TN VALLEY/GULF COAST STATES TO SPREAD INCREASING DEEP MOISTURE EASTWARD AND CLOSER TO THE SE/MID ATLC REGION. SOME INDICATION THAT THE UPPER FLOW BECOMES SPLIT WHICH COULD KEEP MOST OF THE MOISTURE TO OUR SOUTH...SO WILL STILL KEEP POPS IN CHC RANGE OVERNIGHT AND BEYOND. MOSTLY CLOUDY WITH LOWS GENLY IN THE MID- UPPER 60S TO LOWER 70S WITH INCREASING HUMIDITY LEVELS. STUCK IN AN UNSETTLED PATTERN SFC-ALOFT THROUGH EARLY NEXT WK. ONE PIECE OF UPR TROUGH EXITS NEW ENG THROUGH TUE...W/ TRAILING PIECE LINGERING INVOF ERN GULF STATES. MEANWHILE...STRONG RIDGE RMNS ANCHORED FM THE PLAINS THROUGH THE ROCKIES. AT THE SFC...HI PRES TO RMN SITUATED FM NRN MDATLC TO CANADIAN MARITIMES...W/ WK TROUGH FOUND E OF THE CAROLINA CST. DYNAMICS/FORCING FOR PCPN RMNS WK THE NEXT FEW DAYS...AS LO LVL FLO CONTS MNLY FM THE OCN. XPCG VRB CLDS TO PCLDY WX THROUGH THE PD...W/ A CONTD/GRADUAL INCRS IN DEWPTS WHILE (DAYTIME) TEMPS ARE HELD DOWN TO OR BLO SEASONAL NORMALS. BULK OF POPS WILL RMN AOB 30%...AND MNLY FAVOR AREAS INLAND/SRN PORTIONS EACH DAY. HI TEMPS IN THE L/M80S MON...M/U80S TUE. NIGHTTIME LO TEMPS FM THE 60S TO L70S. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... BERMUDA HIGH PRESSURE WILL BECOME THE MORE DOMINANT WX FEATURE AROUND BY THE MIDDLE OF THE COMING WEEK...WITH INCREASING HEAT AND HUMIDITY MORE TYPICAL OF LATE JULY. A COLD FRONT IS FORECAST TO MOVE INTO THE REGION FROM THE NW LATE THURSDAY...BEFORE DROPPING SOUTH INTO THE CAROLINAS LATE IN THE WEEK. TYPICAL DIURNAL TSTM CHANCES ARE EXPECTED WED/THURS WITH INCREASED MOISTURE AND INSTABILITY. TSTM CHANCES SHOULD BE A LITTLE HIGHER THURSDAY DUE TO THE APPROACH OF THE FRONT. ASSUMING THE COLD FRONT IS ABLE TO PUSH SOUTH OF THE AREA ON FRIDAY...ANY PCPN CHANCES WOULD BE LIMITED TO SOUTHERN AREA CLOSET TO THE FRONT WITH HIGH PRESSURE BUILDING IN ACROSS THE NORTH THRU NEXT SATURDAY. HIGHS WED/THURS IN THE UPR 80S TO LOW 90S. HIGHS FRI/SAT IN THE 80S. LOWS THRU THE PERIOD IN THE 60S TO LOW 70S. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... A STALLED FRONTAL BOUNDARY WILL PERSIST OFF THE MID ATLC CST TODAY INTO EARLY TUE...BEFORE WASHING OUT. WEAK HI PRES WILL BE CNTRD JUST OFF THE NEW ENGLAND CST. THIS WILL MAINTAIN A RATHER MOIST NE OR E FLO ACRS THE AREA. MAINLY VFR CONDITIONS SHOULD PREVAIL AT THE TAF SITES...BUT ISLTD MVFR CIGS/VSBYS WILL BE POSSIBLE IN ANY SHOWERS. NOTE: OBSERVATIONS FROM SBY ARE NOT READILY AVAILABLE...TECHNICIANS ARE AWARE OF THE PROBLEM. INCLUDED AMD NOT SKED FOR NOW. && .MARINE... NO HEADLINES IN THE SHORT TERM TODAY THRU MON NGT. INVERTED TROF/SFC BOUNDARY WILL REMAIN JUST OFF THE CST TODAY INTO EARLY TUE. THIS WILL RESULT IN A CONTINUED NE OR E WINDS 15 KT OR LESS ACRS THE WTRS. WAVES WILL RANGE FM 1 TO 3 FT OVR THE RIVERS/CHES BAY/CURRITUCK SND...WHILE SEAS WILL BE 2 TO 4 FT. THAT BOUNDARY WILL WASH OUT EARLY TUE...WITH HI PRES BLDNG OFF THE MID ATLC/SE CST FOR THE REMAINDER OF TUE INTO THU. WINDS WILL TURN FM THE SE TO THE SW DURING THIS TIME. A COLD FRONT WILL PUSH INTO THE WTRS FM THE WNW LATE THU/THU NGT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 7 PM EDT THIS EVENING FOR ANZ650. && $$ SYNOPSIS...ALB/LKB NEAR TERM...ALB/LKB SHORT TERM...ALB/LKB LONG TERM...JDM AVIATION...TMG MARINE...TMG
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
107 PM EDT SUN JUL 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 525 AM EDT SUN JUL 20 2014 PER WATER VAPOR IMAGERY AND RUC ANALYSIS...SHORTWAVE THAT WAS NEAR LAKE WINNIPEG 24HRS AGO IS NOW REACHING SRN HUDSON BAY. ASSOCIATED SFC LOW HAS MOVED OVER HUDSON BAY WITH TRAILING COLD FRONT DISSIPATING OVER NRN ONTARIO. ALTHOUGH SRN PORTION OF FRONT HAS DISSIPATED ON APPROACH TO LAKE SUPERIOR/UPPER MI...CORRIDOR OF WEAK INSTABILITY JUST AHEAD OF WEAK MID LEVEL TROFFING EXTENDING S ACROSS WRN LAKE SUPERIOR/WRN UPPER MI/WRN WI HAS LED TO FAIRLY PERSISTENT SCT -SHRA GENERATION ALONG A NARROW RIBBON FROM A SMALL PORTION OF NW/NCNTRL UPPER MI NNE ACROSS ERN LAKE SUPERIOR OVERNIGHT. HOURLY RUNS OF THE HIGH RES RAPID REFRESH OVERNIGHT HAVE CONTINUED TO GENERATE ISOLD/SCT -SHRA THRU THIS MORNING OVER MAINLY CNTRL UPPER MI ALONG AHEAD OF WEAK MID LEVEL TROF AND WITHIN WEAK INSTABILITY AXIS PER SPC MESOANALYSIS. WITH SOME OF THE OTHER HIGH RES GUIDANCE ALSO SUGGESTING SOME PCPN THIS MORNING...AND SINCE RECENT KMQT RADAR IMAGERY IS STILL SHOWING SPECKLES OF RETURNS OVER WRN UPPER MI...WILL PAINT ISOLD -SHRA OVER PORTIONS OF THE W HALF OF UPPER MI THRU THE MORNING HRS. OTHERWISE...TREND INTO THE AFTN SHOULD BE FOR DRY WEATHER UNDER BUILDING MID LEVEL HEIGHTS AND WITH AN APPARENT LACK OF ANY APPROACHING SHORTWAVES. AS FOR TEMPS... MIXING TO 850-800MB ON NAM/GFS FCST SOUNDINGS SUGGESTS MAX TEMPS TODAY WILL BE A LITTLE HIGHER THAN YESTERDAY...MOSTLY AROUND 80 TO THE MID 80S...BUT LOCALLY WARMER IN THE S WIND DOWNSLOPE AREAS AND OBVIOUSLY COOLER NEAR LAKE MICHIGAN UNDER SOUTHERLY WINDS. NEXT MAIN SHORTWAVE WILL MOVE FROM SASKATCHEWAN THIS MORNING TO HUDSON BAY BY MON AFTN. ASSOCIATED SFC LOW WILL TRACK E WELL N OF THE U.S./CANADA BORDER WITH TRAILING COLD FRONT MOVING INTO NW MN TONIGHT. UNDER AXIS OF VERY UNSTABLE AIR MASS...STRONG/SVR TSTMS SHOULD DEVELOP AHEAD OF COLD FRONT LATE THIS AFTN OR EVENING IN NW AND NRN MN. WITH STRONGER 850MB FLOW THEN BECOMING CONFINED TO NRN ONTARIO TONIGHT...SRN END OF BKN LINE OF STORMS SHOULD TEND TO DISSIPATE WITH NRN PORTION OF STORMS BECOMING MORE ELEVATED AND SHIFTING OVER OR N OF LAKE SUPERIOR LATER TONIGHT. WITH THIS IN MIND...ONLY BRUSHED NW UPPER MI WITH SCHC/LOW CHC POPS OVERNIGHT WITH BETTER PCPN CHANCES OVER NRN LAKE SUPERIOR. WITH SOUTH WINDS STAYING UP TONIGHT AND WITH INCREASING PRECIPITABLE WATER...IT WILL BE A WARMER NIGHT. SOME DOWNSLOPE LOCATIONS ACROSS THE W AND N MAY NOT SEE TEMPS FALL BLO 70F TONIGHT. OTHERWISE...60S WILL MAINLY BE THE RULE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 439 AM EDT SUN JUL 20 2014 MAIN ITEM OF INTEREST ON MON WILL BE ABNORMALLY WARM AND MUGGY CONDITIONS FOR THIS TIME OF YEAR. 850MB TEMPS AROUND 20C AND PARTLY CLOUDY SKIES WILL LEAD TO HIGH TEMPS IN THE 80S TO AROUND 90 INLAND FROM LAKE MICHIGAN WHERE SWLY WINDS WILL KEEP DOWNWIND AREAS COOLER. SFC DEW PTS LOOK TO BE IN THE 60S THROUGHOUT THE DAY. THINK PRECIP CHANCES ARE MINIMAL ON MON DUE TO AN EML BEING OVER THE AREA...RESULTING IN A STRONG CAP. SOME MODELS HAVE SHOWN QPF OVER MAINLY NCENTRAL UPPER MI WHERE THE LAKE SUPERIOR BREEZE WILL BE PINNED NEAR THE SHORELINE WHILE TRYING TO MOVING INLAND AGAINST THE SW WINDS. THINK THAT EVEN A GOOD LAKE BREEZE WILL HAVE TROUBLE LIFTING ANY PARCELS PAST THE LFC...SO LIMITED POPS TO SLIGHT CHANCE. BETTER PRECIP PROBABILITIES ARE FOR MON NIGHT INTO TUE NIGHT AS CONDITIONS WILL FAVOR MCS DEVELOPMENT UPWIND THAT WILL MOVE ACROSS OR NEAR THE CWA DURING THIS TIME. SOME MODELS ALSO INDICATED MORE THAN ONE WAVE OF THUNDERSTORMS THROUGH THIS PERIOD. HAVE LIKELY POPS IN THE FORECAST AS CONFIDENCE OF PRECIP AT SOME POINT DURING THE PERIOD IS HIGH. SEVERE POTENTIAL /AS WITH POPS IN THE GENERAL/ IS HIGHLY CONDITIONAL. INSTABILITY OUT AHEAD OF THE DECAYING MCS WILL BE HIGHLY DEPENDENT ON THE STRENGTH/TRACK/TIMING OF THE CONVECTIVE COMPLEX/ES/. THERE DOES APPEAR TO BE A LIMITED THREAT FOR LARGE HAIL AND DAMAGING WIND...BUT THAT IS HIGHLY UNCERTAIN AND VERY CONDITIONAL ON MANY OTHER FACTORS...SO MANY DETAILS OF THAT ARE IMPOSSIBLE TO ACCURATELY FORECAST AT THIS POINT. A SFC HIGH MOVES INTO THE REGION WED INTO FRI...MAKING FOR A DRY FORECAST AND A COLDER AIRMASS. HIGH TEMPERATURES ARE FORECAST TO BE IN THE 60S AND 70S...COOLEST ON WED WHEN HIGHS WILL BE IN THE 60S TO AROUND 70. UNCERTAINTY INCREASES SUBSTANTIALLY ON SAT DUE TO MODEL DISAGREEMENT...BUT PRECIP CHANCES WILL BE ON THE RISE NEXT WEEKEND DUE TO A MORE UNSETTLED PATTERN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 106 PM EDT SUN JUL 20 2014 VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THIS FCST PERIOD AT ALL SITES. THE REMNANTS OF SHRA/TSRA DEVELOPING IN NRN MN LATE THIS AFTN OR EVENING MAY REACH NW UPPER MI LATE TONIGHT AT CMX. CHANCE IS SO LOW FOR RIGHT NOW...DO NOT HAVE IT IN THE TAF AS CONFIDENCE IS LOW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 525 AM EDT SUN JUL 20 2014 SOUTHERLY WINDS WILL PREVAIL OVER MOST OF LAKE SUPERIOR THRU MON AS HIGH PRES WILL BE LOCATED TO THE E WHILE LOW PRES MOVES ACROSS SRN CANADA. ONE LOW PRES SYSTEM WILL FINALLY CROSS THE UPPER LAKES TUE...BRINGING A WIND SHIFT TO THE N. WINDS THRU THE FCST PERIOD WILL GENERALLY BE UNDER 20 KNOTS. HOWEVER...THERE WILL BE OCNL PERIODS OF STRONGER WINDS (15-30KT) AT THE HIGHER OBS PLATFORMS. THESE STRONGER WINDS WILL AFFECT MAINLY THE E HALF OF LAKE SUPERIOR...PARTICULARLY TONIGHT. FOG SHOULD SLOWLY DEVELOP/EXPAND OVER THE LAKE...ESPECIALLY AFTER ANY PCPN OCCURS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
741 AM EDT SUN JUL 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 525 AM EDT SUN JUL 20 2014 PER WATER VAPOR IMAGERY AND RUC ANALYSIS...SHORTWAVE THAT WAS NEAR LAKE WINNIPEG 24HRS AGO IS NOW REACHING SRN HUDSON BAY. ASSOCIATED SFC LOW HAS MOVED OVER HUDSON BAY WITH TRAILING COLD FRONT DISSIPATING OVER NRN ONTARIO. ALTHOUGH SRN PORTION OF FRONT HAS DISSIPATED ON APPROACH TO LAKE SUPERIOR/UPPER MI...CORRIDOR OF WEAK INSTABILITY JUST AHEAD OF WEAK MID LEVEL TROFFING EXTENDING S ACROSS WRN LAKE SUPERIOR/WRN UPPER MI/WRN WI HAS LED TO FAIRLY PERSISTENT SCT -SHRA GENERATION ALONG A NARROW RIBBON FROM A SMALL PORTION OF NW/NCNTRL UPPER MI NNE ACROSS ERN LAKE SUPERIOR OVERNIGHT. HOURLY RUNS OF THE HIGH RES RAPID REFRESH OVERNIGHT HAVE CONTINUED TO GENERATE ISOLD/SCT -SHRA THRU THIS MORNING OVER MAINLY CNTRL UPPER MI ALONG AHEAD OF WEAK MID LEVEL TROF AND WITHIN WEAK INSTABILITY AXIS PER SPC MESOANALYSIS. WITH SOME OF THE OTHER HIGH RES GUIDANCE ALSO SUGGESTING SOME PCPN THIS MORNING...AND SINCE RECENT KMQT RADAR IMAGERY IS STILL SHOWING SPECKLES OF RETURNS OVER WRN UPPER MI...WILL PAINT ISOLD -SHRA OVER PORTIONS OF THE W HALF OF UPPER MI THRU THE MORNING HRS. OTHERWISE...TREND INTO THE AFTN SHOULD BE FOR DRY WEATHER UNDER BUILDING MID LEVEL HEIGHTS AND WITH AN APPARENT LACK OF ANY APPROACHING SHORTWAVES. AS FOR TEMPS... MIXING TO 850-800MB ON NAM/GFS FCST SOUNDINGS SUGGESTS MAX TEMPS TODAY WILL BE A LITTLE HIGHER THAN YESTERDAY...MOSTLY AROUND 80 TO THE MID 80S...BUT LOCALLY WARMER IN THE S WIND DOWNSLOPE AREAS AND OBVIOUSLY COOLER NEAR LAKE MICHIGAN UNDER SOUTHERLY WINDS. NEXT MAIN SHORTWAVE WILL MOVE FROM SASKATCHEWAN THIS MORNING TO HUDSON BAY BY MON AFTN. ASSOCIATED SFC LOW WILL TRACK E WELL N OF THE U.S./CANADA BORDER WITH TRAILING COLD FRONT MOVING INTO NW MN TONIGHT. UNDER AXIS OF VERY UNSTABLE AIR MASS...STRONG/SVR TSTMS SHOULD DEVELOP AHEAD OF COLD FRONT LATE THIS AFTN OR EVENING IN NW AND NRN MN. WITH STRONGER 850MB FLOW THEN BECOMING CONFINED TO NRN ONTARIO TONIGHT...SRN END OF BKN LINE OF STORMS SHOULD TEND TO DISSIPATE WITH NRN PORTION OF STORMS BECOMING MORE ELEVATED AND SHIFTING OVER OR N OF LAKE SUPERIOR LATER TONIGHT. WITH THIS IN MIND...ONLY BRUSHED NW UPPER MI WITH SCHC/LOW CHC POPS OVERNIGHT WITH BETTER PCPN CHANCES OVER NRN LAKE SUPERIOR. WITH SOUTH WINDS STAYING UP TONIGHT AND WITH INCREASING PRECIPITABLE WATER...IT WILL BE A WARMER NIGHT. SOME DOWNSLOPE LOCATIONS ACROSS THE W AND N MAY NOT SEE TEMPS FALL BLO 70F TONIGHT. OTHERWISE...60S WILL MAINLY BE THE RULE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 439 AM EDT SUN JUL 20 2014 MAIN ITEM OF INTEREST ON MON WILL BE ABNORMALLY WARM AND MUGGY CONDITIONS FOR THIS TIME OF YEAR. 850MB TEMPS AROUND 20C AND PARTLY CLOUDY SKIES WILL LEAD TO HIGH TEMPS IN THE 80S TO AROUND 90 INLAND FROM LAKE MICHIGAN WHERE SWLY WINDS WILL KEEP DOWNWIND AREAS COOLER. SFC DEW PTS LOOK TO BE IN THE 60S THROUGHOUT THE DAY. THINK PRECIP CHANCES ARE MINIMAL ON MON DUE TO AN EML BEING OVER THE AREA...RESULTING IN A STRONG CAP. SOME MODELS HAVE SHOWN QPF OVER MAINLY NCENTRAL UPPER MI WHERE THE LAKE SUPERIOR BREEZE WILL BE PINNED NEAR THE SHORELINE WHILE TRYING TO MOVING INLAND AGAINST THE SW WINDS. THINK THAT EVEN A GOOD LAKE BREEZE WILL HAVE TROUBLE LIFTING ANY PARCELS PAST THE LFC...SO LIMITED POPS TO SLIGHT CHANCE. BETTER PRECIP PROBABILITIES ARE FOR MON NIGHT INTO TUE NIGHT AS CONDITIONS WILL FAVOR MCS DEVELOPMENT UPWIND THAT WILL MOVE ACROSS OR NEAR THE CWA DURING THIS TIME. SOME MODELS ALSO INDICATED MORE THAN ONE WAVE OF THUNDERSTORMS THROUGH THIS PERIOD. HAVE LIKELY POPS IN THE FORECAST AS CONFIDENCE OF PRECIP AT SOME POINT DURING THE PERIOD IS HIGH. SEVERE POTENTIAL /AS WITH POPS IN THE GENERAL/ IS HIGHLY CONDITIONAL. INSTABILITY OUT AHEAD OF THE DECAYING MCS WILL BE HIGHLY DEPENDENT ON THE STRENGTH/TRACK/TIMING OF THE CONVECTIVE COMPLEX/ES/. THERE DOES APPEAR TO BE A LIMITED THREAT FOR LARGE HAIL AND DAMAGING WIND...BUT THAT IS HIGHLY UNCERTAIN AND VERY CONDITIONAL ON MANY OTHER FACTORS...SO MANY DETAILS OF THAT ARE IMPOSSIBLE TO ACCURATELY FORECAST AT THIS POINT. A SFC HIGH MOVES INTO THE REGION WED INTO FRI...MAKING FOR A DRY FORECAST AND A COLDER AIRMASS. HIGH TEMPERATURES ARE FORECAST TO BE IN THE 60S AND 70S...COOLEST ON WED WHEN HIGHS WILL BE IN THE 60S TO AROUND 70. UNCERTAINTY INCREASES SUBSTANTIALLY ON SAT DUE TO MODEL DISAGREEMENT...BUT PRECIP CHANCES WILL BE ON THE RISE NEXT WEEKEND DUE TO A MORE UNSETTLED PATTERN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 741 AM EDT SUN JUL 20 2014 VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THIS FCST PERIOD AT KIWD/KCMX/KSAW. THE REMNANTS OF SHRA/TSRA DEVELOPING IN NRN MN LATE THIS AFTN OR EVENING MAY REACH NW UPPER MI LATE TONIGHT. FOR NOW... INCLUDED A VCSH MENTION AT KCMX. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 525 AM EDT SUN JUL 20 2014 SOUTHERLY WINDS WILL PREVAIL OVER MOST OF LAKE SUPERIOR THRU MON AS HIGH PRES WILL BE LOCATED TO THE E WHILE LOW PRES MOVES ACROSS SRN CANADA. ONE LOW PRES SYSTEM WILL FINALLY CROSS THE UPPER LAKES TUE...BRINGING A WIND SHIFT TO THE N. WINDS THRU THE FCST PERIOD WILL GENERALLY BE UNDER 20 KNOTS. HOWEVER...THERE WILL BE OCNL PERIODS OF STRONGER WINDS (15-30KT) AT THE HIGHER OBS PLATFORMS. THESE STRONGER WINDS WILL AFFECT MAINLY THE E HALF OF LAKE SUPERIOR...PARTICULARLY TONIGHT. FOG SHOULD SLOWLY DEVELOP/EXPAND OVER THE LAKE...ESPECIALLY AFTER ANY PCPN OCCURS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
528 AM EDT SUN JUL 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 525 AM EDT SUN JUL 20 2014 PER WATER VAPOR IMAGERY AND RUC ANALYSIS...SHORTWAVE THAT WAS NEAR LAKE WINNIPEG 24HRS AGO IS NOW REACHING SRN HUDSON BAY. ASSOCIATED SFC LOW HAS MOVED OVER HUDSON BAY WITH TRAILING COLD FRONT DISSIPATING OVER NRN ONTARIO. ALTHOUGH SRN PORTION OF FRONT HAS DISSIPATED ON APPROACH TO LAKE SUPERIOR/UPPER MI...CORRIDOR OF WEAK INSTABILITY JUST AHEAD OF WEAK MID LEVEL TROFFING EXTENDING S ACROSS WRN LAKE SUPERIOR/WRN UPPER MI/WRN WI HAS LED TO FAIRLY PERSISTENT SCT -SHRA GENERATION ALONG A NARROW RIBBON FROM A SMALL PORTION OF NW/NCNTRL UPPER MI NNE ACROSS ERN LAKE SUPERIOR OVERNIGHT. HOURLY RUNS OF THE HIGH RES RAPID REFRESH OVERNIGHT HAVE CONTINUED TO GENERATE ISOLD/SCT -SHRA THRU THIS MORNING OVER MAINLY CNTRL UPPER MI ALONG AHEAD OF WEAK MID LEVEL TROF AND WITHIN WEAK INSTABILITY AXIS PER SPC MESOANALYSIS. WITH SOME OF THE OTHER HIGH RES GUIDANCE ALSO SUGGESTING SOME PCPN THIS MORNING...AND SINCE RECENT KMQT RADAR IMAGERY IS STILL SHOWING SPECKLES OF RETURNS OVER WRN UPPER MI...WILL PAINT ISOLD -SHRA OVER PORTIONS OF THE W HALF OF UPPER MI THRU THE MORNING HRS. OTHERWISE...TREND INTO THE AFTN SHOULD BE FOR DRY WEATHER UNDER BUILDING MID LEVEL HEIGHTS AND WITH AN APPARENT LACK OF ANY APPROACHING SHORTWAVES. AS FOR TEMPS... MIXING TO 850-800MB ON NAM/GFS FCST SOUNDINGS SUGGESTS MAX TEMPS TODAY WILL BE A LITTLE HIGHER THAN YESTERDAY...MOSTLY AROUND 80 TO THE MID 80S...BUT LOCALLY WARMER IN THE S WIND DOWNSLOPE AREAS AND OBVIOUSLY COOLER NEAR LAKE MICHIGAN UNDER SOUTHERLY WINDS. NEXT MAIN SHORTWAVE WILL MOVE FROM SASKATCHEWAN THIS MORNING TO HUDSON BAY BY MON AFTN. ASSOCIATED SFC LOW WILL TRACK E WELL N OF THE U.S./CANADA BORDER WITH TRAILING COLD FRONT MOVING INTO NW MN TONIGHT. UNDER AXIS OF VERY UNSTABLE AIR MASS...STRONG/SVR TSTMS SHOULD DEVELOP AHEAD OF COLD FRONT LATE THIS AFTN OR EVENING IN NW AND NRN MN. WITH STRONGER 850MB FLOW THEN BECOMING CONFINED TO NRN ONTARIO TONIGHT...SRN END OF BKN LINE OF STORMS SHOULD TEND TO DISSIPATE WITH NRN PORTION OF STORMS BECOMING MORE ELEVATED AND SHIFTING OVER OR N OF LAKE SUPERIOR LATER TONIGHT. WITH THIS IN MIND...ONLY BRUSHED NW UPPER MI WITH SCHC/LOW CHC POPS OVERNIGHT WITH BETTER PCPN CHANCES OVER NRN LAKE SUPERIOR. WITH SOUTH WINDS STAYING UP TONIGHT AND WITH INCREASING PRECIPITABLE WATER...IT WILL BE A WARMER NIGHT. SOME DOWNSLOPE LOCATIONS ACROSS THE W AND N MAY NOT SEE TEMPS FALL BLO 70F TONIGHT. OTHERWISE...60S WILL MAINLY BE THE RULE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 439 AM EDT SUN JUL 20 2014 MAIN ITEM OF INTEREST ON MON WILL BE ABNORMALLY WARM AND MUGGY CONDITIONS FOR THIS TIME OF YEAR. 850MB TEMPS AROUND 20C AND PARTLY CLOUDY SKIES WILL LEAD TO HIGH TEMPS IN THE 80S TO AROUND 90 INLAND FROM LAKE MICHIGAN WHERE SWLY WINDS WILL KEEP DOWNWIND AREAS COOLER. SFC DEW PTS LOOK TO BE IN THE 60S THROUGHOUT THE DAY. THINK PRECIP CHANCES ARE MINIMAL ON MON DUE TO AN EML BEING OVER THE AREA...RESULTING IN A STRONG CAP. SOME MODELS HAVE SHOWN QPF OVER MAINLY NCENTRAL UPPER MI WHERE THE LAKE SUPERIOR BREEZE WILL BE PINNED NEAR THE SHORELINE WHILE TRYING TO MOVING INLAND AGAINST THE SW WINDS. THINK THAT EVEN A GOOD LAKE BREEZE WILL HAVE TROUBLE LIFTING ANY PARCELS PAST THE LFC...SO LIMITED POPS TO SLIGHT CHANCE. BETTER PRECIP PROBABILITIES ARE FOR MON NIGHT INTO TUE NIGHT AS CONDITIONS WILL FAVOR MCS DEVELOPMENT UPWIND THAT WILL MOVE ACROSS OR NEAR THE CWA DURING THIS TIME. SOME MODELS ALSO INDICATED MORE THAN ONE WAVE OF THUNDERSTORMS THROUGH THIS PERIOD. HAVE LIKELY POPS IN THE FORECAST AS CONFIDENCE OF PRECIP AT SOME POINT DURING THE PERIOD IS HIGH. SEVERE POTENTIAL /AS WITH POPS IN THE GENERAL/ IS HIGHLY CONDITIONAL. INSTABILITY OUT AHEAD OF THE DECAYING MCS WILL BE HIGHLY DEPENDENT ON THE STRENGTH/TRACK/TIMING OF THE CONVECTIVE COMPLEX/ES/. THERE DOES APPEAR TO BE A LIMITED THREAT FOR LARGE HAIL AND DAMAGING WIND...BUT THAT IS HIGHLY UNCERTAIN AND VERY CONDITIONAL ON MANY OTHER FACTORS...SO MANY DETAILS OF THAT ARE IMPOSSIBLE TO ACCURATELY FORECAST AT THIS POINT. A SFC HIGH MOVES INTO THE REGION WED INTO FRI...MAKING FOR A DRY FORECAST AND A COLDER AIRMASS. HIGH TEMPERATURES ARE FORECAST TO BE IN THE 60S AND 70S...COOLEST ON WED WHEN HIGHS WILL BE IN THE 60S TO AROUND 70. UNCERTAINTY INCREASES SUBSTANTIALLY ON SAT DUE TO MODEL DISAGREEMENT...BUT PRECIP CHANCES WILL BE ON THE RISE NEXT WEEKEND DUE TO A MORE UNSETTLED PATTERN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 123 AM EDT SUN JUL 20 2014 VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE FCST PERIOD AT KIWD/KCMX/KSAW. AN APPROACHING WEAKENING COLD FRONT AND DISTURBANCE MAY BRING A FEW SHRA/TSRA INTO WRN UPPER MI OVERNIGHT. HOWEVER...CONFIDENCE IS TOO LOW TO INCLUDE ANY MENTION OF SHRA DUE TO EXPECTED LIMITED COVERAGE/INTENSITY OF ANY PCPN. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 525 AM EDT SUN JUL 20 2014 SOUTHERLY WINDS WILL PREVAIL OVER MOST OF LAKE SUPERIOR THRU MON AS HIGH PRES WILL BE LOCATED TO THE E WHILE LOW PRES MOVES ACROSS SRN CANADA. ONE LOW PRES SYSTEM WILL FINALLY CROSS THE UPPER LAKES TUE...BRINGING A WIND SHIFT TO THE N. WINDS THRU THE FCST PERIOD WILL GENERALLY BE UNDER 20 KNOTS. HOWEVER...THERE WILL BE OCNL PERIODS OF STRONGER WINDS (15-30KT) AT THE HIGHER OBS PLATFORMS. THESE STRONGER WINDS WILL AFFECT MAINLY THE E HALF OF LAKE SUPERIOR...PARTICULARLY TONIGHT. FOG SHOULD SLOWLY DEVELOP/EXPAND OVER THE LAKE...ESPECIALLY AFTER ANY PCPN OCCURS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...JLB MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
934 PM CDT Mon Jul 21 2014 .UPDATE: Issued at 920 PM CDT Mon Jul 21 2014 The going forecast remains on track this evening, with only minor changes to account for near-term trends. The HRRR has continued to indicate some showers developing over northeastern MO and west central IL around daybreak, but recent runs have gotten more conservative. Therefore, have maintained the dry forecast given low confidence. JP && .SHORT TERM: (Tonight through Tuesday) Issued at 322 PM CDT Mon Jul 21 2014 The forecast is evolving pretty much as expected today and the trends anticipated through tomorrow still look on track. Temperatures tonight will be milder than last night with a gradual increase in some mid/high clouds from the northwest late tonight. Still wondering if we might see a few high based showers with this mid level moisture and steep lapse rates near and just after dawn across north central/northeast Missouri, but at this point my confidence is not high enough to add pops and later shifts will need to keep a close eye. Otherwise the hotest day of the week is still on tap for Tuesday with a strong low-level thermal ridge focused across the northern half of the CWA with H85 temps above +22 degC, favoring widespread highs in the 90s. The northwest 1/3-1/2 of the CWA should have peak heat index values above 100 degrees. If the dew points top the mid 70s across northeast Missouri, then some locations might see heat indices hit advisory criteria of 105+. At this point my forecast is just below that value. Warm mid level temperatures of +12 to +14 degC should sufficiently cap surface based convection. Glass .LONG TERM: (Tuesday Night through Next Monday) Issued at 322 PM CDT Mon Jul 21 2014 A short wave will dig across the upper-mid MS valley and into the Great Lakes Tuesday night into Wednesday, and this will send a formidable cold front across the region. The air mass ahead of the front will be moist and unstable and height falls/cooling aloft associated with the upper wave should be sufficient for scattered thunderstorms/multicell clusters with the progressing front. The front and precipitation threat should be south of the CWA by early Wednesday evening. Deepening of the eastern trof and and an expansive surface high in the wake of the cold front will bring another nice couple of days with below average temperatures for Thursday/Friday. However by late Friday and especially Friday night into Saturday we will be looking at increasing precipitation chances again - first in association with several northwest flow disturbances and the retreating front, and then with another cold front passage. Glass && .AVIATION: (For the 00z TAFs through 00z Tuesday Evening) Issued at 609 PM CDT Mon Jul 21 2014 Dry thru the TAF period with sly to sswly winds aob 10 kts. VFR at all terminals except FG potential at KSUS overnight. Tilly && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
249 PM MDT SUN JUL 20 2014 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY... UPPER FLOW WILL GRADUALLY SHIFT TO THE SOUTHWEST TONIGHT AND ON MONDAY AS A TROUGH DIGS INTO THE PACIFIC NORTHWEST. THIS WILL PROVIDE ENOUGH MOISTURE TO PRODUCE A FEW WIDELY SCATTERED SHOWERS AND THUNDERSTORMS STARTING TONIGHT. THIS HAS SUPPORT FROM THE LATEST ECMWF/GFS/NAM/SREF AS WELL AS RECENT HRRR RUNS...ALTHOUGH THERE ARE TIMING/PLACEMENT DIFFERENCES IN THE MODEL SOLUTIONS. VORTICITY STREAMING ACROSS THE FLOW ALOFT MAY ENHANCE CHANCES IN SOME PLACES ON MONDAY AFTERNOON AND EVENING AND AGAIN ON TUESDAY AFTERNOON AND EVENING AHEAD OF APPROACHING EMBEDDED SHORTWAVES. PEAK HEATING ALONG WITH LIMITED MOISTURE MAY ALLOW FOR CONVECTION INITIATION DURING THESE TIME PERIODS IN PARTICULAR. WHILE PRECISE TIMING/PLACEMENT ARE STILL IN QUESTION DID TREND POPS IN ACCORDANCE WITH THE LATEST GUIDANCE WHERE BEST CONSENSUS EXISTS. THE SHIFT IN THE UPPER FLOW COMBINED WITH PRECIPITATION CHANCES WILL ALSO SQUASH THE RECENT HAZE/SMOKE CONDITIONS THAT HAVE BEEN EXPERIENCED ACROSS THE CWA AS OF LATE. MALIAWCO .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY... AFTERNOON UPDATE...THE UPDATE FOCUSED ON WEDNESDAY AND THURSDAY AS A STRONG LOW PRESSURE SYSTEM MOVES ACROSS THE AREA. STRONG SOUTHEAST WINDS AHEAD OF THE SYSTEM WITH STRONGER WEST/NORTHWEST WINDS BEHIND IT. COULD ALSO SEE SOME POTENTIAL SEVERE WEATHER WITH THE FRONTAL SYSTEM AS IT MOVES THROUGH BUT THERE ISN`T A HUGE SOURCE OF MOISTURE TO DRAW FROM. FRANSEN SYNOPTIC SET UP... A LARGE HIGH PRESSURE HEAT DOME EXISTS OVER THE FOUR CORNERS REGION WITH A RIDGE JUTTING OUT OVER WYOMING... MONTANA AND INTO NORTHERN ALBERTA. A TROUGH EXTEND THROUGH THE UPPER MISSISSIPPI VALLEY THROUGH THE HUDSON BAY. WHILE A CLOSED LOW SETS OVER THE COASTS OF THE PACIFIC NORTHWEST AND BRITISH COLUMBIA. TUESDAY NIGHT THROUGH WEDNESDAY... RIDGE OVER MONTANA WILL INTENSIFY DURING THESE PERIODS ALLOWING MONSOONAL MOISTURE TO SNEAK INTO THE AREA DURING THE OVERNIGHT HOURS. RH RECOVERIES TUESDAY NIGHT WILL ALLOWS SOME OF THIS TO REACH THE SURFACE HOWEVER... IMPACT WILL BE MINIMAL WEDNESDAY AS SURFACE LAYER IS EXPECTED TO BE DRY AND EVAPORATE ANY RAIN BEFORE IT HITS THE SURFACE. ON WEDNESDAY THE RIDGE WILL INTENSIFY AS THE CLOSED LOW TRANSVERSES THE PACIFIC NORTHWEST INTO WESTERN MONTANA. WARMEST TEMPERATURES WILL BE DURING THIS DAY AS NORTHEAST MONTANA ENTERS THE WARM SECTOR OF THE APPROACHING LOW WITH HIGHS IN THE 90S... UPPER 90S TO 100S ARE NOT OUT OF THE QUESTION... ESPECIALLY ALONG THE MISSOURI BREAKS. WEDNESDAY NIGHT THROUGH THURSDAY... THIS RIDGE WILL BEGIN EXITING TO THE EAST AS MULTIPLE SHORTWAVE ENTER THE AREA... THE BREAKDOWN OF THIS RIDGE OVERNIGHT MAY NEED SOME WATCHING AS STORMS COULD DEVELOP PACIFIC MOISTURE AND HIGH ENERGY POTENTIAL ADDING TO JET LIFT IN THE MID TO HIGH LEVELS. CHANCE FOR SHOWERS AND THUNDERSTORMS DURING THESE PERIODS ARE STEADILY GROWING AND SEVERE WEATHER IS NOT OUT OF THE QUESTION. THURSDAY NIGHT THROUGH FRIDAY NIGHT...CLOSED LOW WILL TRANSVERSE THE ROCKIES AND REPRESS THE RIDGE OVER THE AREA. WEAK SHORTWAVES ALONG WITH THE INITIAL COLD FRONT WILL BRING SOME TEMPERATURES DROPS AND ISOLATED SHOWERS TO THE AREA. SATURDAY ONWARD... HEAT DOME OVER THE INTERMOUNTAIN WEST WILL EXPAND INTO THE PACIFIC NORTHWEST AS A LARGE RIDGE AGAIN. THIS WILL PLACE NORTHEAST MONTANA IN A DRIER STABILIZED NORTHWEST FLOW THROUGH THE WEEKEND. GAH && .AVIATION... FLIGHT CATEGORY: VFR TO MVFR. HAZE: IMPROVING AS MID LEVEL FLOW TRANSITIONS FROM WESTERLY TO SOUTHWESTERLY. AREA WINDS: WINDS IN THE 12 TO 22 KNOT RANGE AND DECREASING BY SUNSET. WEATHER: A WEAK FRONT IS MOVING THROUGH AND THERE COULD BE SOME SHOWERS AND ISOLATED THUNDERSTORMS. AT THIS TIME KSDY AND KGDV LOOK TO HAVE THE BEST CHANCE FOR THEM BETWEEN 03 AND 06Z. FRANSEN && .FIRE WEATHER... KEEPING AN EYE ON THE AREA FOR WEDNESDAY INTO THURSDAY AS A LOW PRESSURE SYSTEM AND COLD FRONT MOVE THROUGH THE AREA. STRONG SOUTHEAST WINDS OF 10 TO 20 MPH GUSTING TO 25 MPH ARE EXPECTED AHEAD OF THE FRONT. THE FRONTAL PASSAGE COMES THROUGH WEDNESDAY NIGHT INTO THURSDAY MORNING. WINDS WILL SWITCH TO THE WEST/WEST- NORTHWEST AT 15 TO 25 MPH WITH GUSTS TO 30 MPH POSSIBLE. IT LOOKS LIKE HUMIDITIES WILL BOTTOM OUT WEDNESDAY AFTERNOON WITH READINGS IN THE MID TEENS IN ZONES 135 136 AND 137. TO ADD TO THE CONCERN...COULD ALSO SEE THUNDERSTORMS WITH THE FRONTAL PASSAGE SPARKING LIGHTNING CONCERNS. THERE ISN`T A TON OF MOISTURE TO WORK WITH EITHER SO THAT ADDS TO THE CONCERN AS WELL. WILL NEED TO KEEP AN EYE ON THIS TIME PERIOD FOR A POSSIBLE FIRE WEATHER WATCH. && .GLASGOW WATCHES/WARNINGS/ADVISORIES... LAKE WIND ADVISORY UNTIL 7 PM MDT THIS EVENING FOR FORT PECK LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...GARFIELD...MCCONE...PETROLEUM. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1237 PM CDT SUN JUL 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 450 AM CDT SUN JUL 20 2014 THE MAIN CONCERN FOR THE SHORT TERM PERIODS IS TO WHAT EXTENT STRATUS WILL HAVE TEMPERATURES TODAY. THE PATTERN ALOFT FEATURED NORTHWEST FLOW ACROSS THE INTERIOR CONUS...WITH AN UPPER RIDGE AXIS BUILDING NORTH FM THE FOUR CORNERS REGION. FARTHER NORTH ACROSS THE SOUTHERN CANADIAN PROVINCES AND THE NORTHERN CONUS THE FLOW WAS MORE ZONAL. AT THE SURFACE...LOW PRESSURE EXTENDED ALONG THE HIGH PLAINS WITH SOUTHERLY LLVL FLOW IN PLACE ACROSS OUR REGION. MOISTURE HAS MADE A RETURN WITH SFC DPS AVERAGING LOW/MID 60S. SIMILAR TO THE LAST COUPLE OF NIGHTS...WE ARE LOOKING THE DEVELOPMENT OF STRATUS AGAIN THIS MORNING. THE STRATUS CLOUDS INITIATED ALONG OUR WESTERN CWA BORDER AND THE AREA OF STRATUS WAS EXPANDING ACROSS WESTERN AND CENTRAL NEBRASKA. THE HRRR SUGGESTS THE MAIN AREA OF STRATUS WILL SPREAD EASTWARD FOR A FEW HOURS AND THEN RAPIDLY ERODE AFTER DAYBREAK WHEREAS RAP/NAM SUGGEST THE AREAS WILL EXPAND EASTWARD AND ERODE W/E TODAY. WILL CONTINUE TO MONITOR TRENDS OF STRATUS DEVELOPMENT AND ANY POTENTIAL FOR VSBY RESTRICTIONS OR DRIZZLE. GIVEN MODEL PERFORMANCE THE LAST COUPLE OF DAYS...FORECAST MODELS HAVE BEEN TOO QUICK IN ERODING THE LOW CLOUDS AND THE CLOUD COVER HAS KEPT HIGH TEMPS SEVERAL DEGREES COOLER THAN FORECAST. WITH THIS IN MIND...THE TEMPERATURE FORECAST TODAY WILL BE DEPENDENT UPON CLOUD COVER. THE UPPER RIDGE AXIS WILL BUILD NORTH AND EASTWARD ACROSS THE CENTRAL PLAINS TODAY AND THE AIRMASS HEATS UP. H85 TEMPS ARE PROGGED TO REACH THE LOW 20S CELSIUS ACROSS OUR EASTERN ZONES AND WILL BE NEAR 30 CELSIUS IN THE WEST. FULLY MIXED THIS WILL LEAD TO HIGHS FROM THE UPPER 80S TO WELL INTO THE 90S...BUT WITH THE DEVELOPING LOW CLOUD COVER AND UNCERTAINTY IN HOW LONG CLOUDS WILL LINGER AND WITH HIGHER DPS IN PLACE...OPTED TO STAY RELATIVELY CONSERVATIVE WITH TEMPS THIS AFTERNOON. HAVE RANGED HIGHS FROM THE UPPER 80S IN OUR EAST...TO NEAR 100F IN THE WEST. BELIEVE THERE WILL BE A DECENT GRADIENT IN TEMPS DUE TO HIGHER DPS IN OUR NE AND WHERE THERE IS THE POTENTIAL FOR CLOUDS TO LINGER LONGER TODAY. FARTHER WEST...MODELS INDICATE DRIER AIR ADVECTING IN WITH DPS IN THE UPPER 50S TO NEAR 60 PUSHING EAST WITH SFC BOUNDARY WHICH WILL AID IN WARMING TEMPS...AND STRATUS DOES LOOK TO ERODE QUICKER FOR OUR SW COUNTIES. CONVECTIVE TEMPS ARE NEAR 100F AND COULD SEE SOME CU TRY TO FORM IN THE AFTN AGAIN IN OUR SW CWA. WITH THE MORE CONSERVATIVE HIGH TEMP FORECAST TODAY...HEAT INDEX VALUES NEAR 100F ARE MORE FAVORABLE FOR OUR SOUTHWEST ZONES WHERE HIGHER TEMPS ARE EXPECTED. AT SOME POINT IN THIS PATTERN THE HEAT WILL TURN ON...BUT WE NEED TO BE FREE FROM THE LOW CLOUDS. FOR TONIGHT...OVERALL DRY CONDITIONS ARE EXPECTED. THERE IS A SUBTLE SHORTWAVE THAT IS PROGGED TO MOVE THRU BUT CHCS LOOK RATHER SLIM FOR CONVECTIVE DEVELOPMENT WITH WARM MID LEVEL TEMPS/CAPPING. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 450 AM CDT SUN JUL 20 2014 AS HAS ALREADY BEEN WIDELY-ADVERTISED FOR A FEW DAYS NOW...THE MOST IMMEDIATE AND CURRENTLY-PRIMARY FOCUS OF THIS 6-DAY PERIOD REVOLVES AROUND CONSECUTIVE AFTERNOONS OF FORECASTED 100+ DEGREE HEAT INDEX VALUES ON MONDAY-TUESDAY...WITH A DECENT CHUNK OF MAINLY THE EASTERN 1/2 OF THE CWA CURRENTLY ADVERTISED TO OBSERVE AT LEAST BRIEF PERIODS OF ADVISORY-CRITERIA HEAT INDEX READINGS OF 105-109 DEGREES. BEYOND TUESDAY...IT IS EXPECTED TO REMAIN SEASONABLY WARM/HOT THE REMAINDER OF THE WEEK...BUT NOTHING THAT APPEARS TO SUPPORT HEAT ADVISORY CONDITIONS...ALTHOUGH IF CURRENT TRENDS HOLD WILL HAVE TO KEEP AN EYE ON MAINLY KS ZONES FOR A POSSIBLE BRUSH WITH NEAR-ADVISORY HEAT INDEX AROUND 100 DEGREES ON FRIDAY. ALTHOUGH THE OFFICIAL FORECAST FAIRLY-STRONGLY SUPPORTS HEAT ADVISORY ISSUANCE FOR MUCH OF THE CWA ON BOTH MONDAY AND TUESDAY...WANT TO MAKE IT CLEAR HERE THAT THE TEMPERATURE TRENDS OF THE PAST FEW DAYS (FALLING SEVERAL DEGREES SHORT OF FORECAST HIGHS IN MANY AREAS) LENDS SOME UNCERTAINTY REGARDING WHETHER MODELS AND THE CURRENT FORECAST MAY IN FACT BE OVER-DOING THE HEAT SITUATION SLIGHTLY. IN OTHER WORDS...WHILE ITS A FOREGONE CONCLUSION THAT IT WILL IN FACT BE QUITE HOT ESPECIALLY COMPARED TO THE RECENT COOL STRETCH...THERE ARE STILL SOME QUESTIONS REGARDING WHETHER MAX HEAT INDEX VALUES WILL AVERAGE CLOSER TO 100 DEGREES WHICH IS NOT ALL THAT UNCOMMON BY LATE-JULY STANDARDS...OR MORE SO INTO THE MORE HAZARDOUS 105+ TERRITORY. AS A RESULT OF THESE UNCERTAINTIES...HAVE COORDINATED WITH MOST SURROUNDING WFOS TO HOLD OFF ON ANY ADVISORIES FOR MONDAY AFTERNOON FOR NOW (LET ALONE TUESDAY)...AND THUS ALLOW THE NEXT 1-2 SHIFTS TO HOPEFULLY GAIN A BIT MORE CONFIDENCE IN THE MAGNITUDE OF THIS HEAT BLAST. AS FOR SHOWER/THUNDERSTORM CHANCES THROUGH THIS 6-DAY PERIOD...THE NUMBER OF 12-HOUR PERIODS WITH SLIGHT CHANCES HAS INCREASED A BIT VERSUS 24 HOURS AGO...BUT THE KEY WORD THERE IS SLIGHT CHANCES...AND CURRENTLY HAVE NO POPS ABOVE 20 PERCENT TERRITORY GIVEN CONSIDERABLE UNCERTAINTY IN MODEL DIFFERENCES AND ALSO WHETHER OR NOT FAIRLY STRONG CAPPING THROUGH MUCH OF THIS TIME FRAME CAN BE OVERCOME. ALTHOUGH THE DEGREE OF INSTABILITY ALONE MAKES IT ALMOST IMPOSSIBLE TO RULE OUT AT LEAST ON ISOLATED STRONG-SEVERE STORM DURING SEVERAL PERIODS...THE PREDOMINANTLY SUBTLE FORCING AND GENERALLY WEAKER DEEP-LAYER SHEAR REGIME THROUGH MOST OF THE WEEK (GENERALLY LESS THAN 30KT) LENDS ITSELF TO CONSIDERABLE UNCERTAINTY REGARDING WHICH (IF ANY) PERIODS ARE WORTHY OF A FORMAL SEVERE MENTION IN THE HAZARDOUS WEATHER OUTLOOK (HWOGID). AT LEAST FOR ONE MORE FORECAST CYCLE...WILL KEEP OUT A FORMAL SEVERE MENTION DESPITE THE FACT THAT THE STORM PREDICTION CENTER BARELY CLIPS SMALL PORTIONS OF THE CWA WITH LOW-END 5 PERCENT SEVERE PROBS ON BOTH THE DAY 2-3 OUTLOOKS. ALTHOUGH NOT GUARANTEED TO STAY THIS WAY BY ANY MEANS...ONLY 3 OF THE 11 LONG TERM FORECAST PERIODS ARE COMPLETELY VOID OF SLIGHT POPS: WEDNESDAY DAYTIME...FRIDAY DAYTIME AND SATURDAY DAYTIME. GETTING INTO SOME MORE METEOROLOGICAL DETAIL AND TAKING IT IN MAINLY 24-HOUR BLOCKS... MONDAY DAYTIME-MONDAY NIGHT...THE BIG STORY IN THE MID-UPPER LEVELS INVOLVES HEIGHT RISES ASSOCIATED WITH THE INCREASING-LOCAL INFLUENCE OF AN EXPANSIVE HIGH PRESSURE RIDGE ENCOMPASSING MUCH OF THE SOUTHERN HALF OF THE CONUS BUT GENERALLY REMAINING CENTERED OVER NEW MEXICO. UNDER THIS RIDGE AXIS...WARM MID LEVEL TEMPS OF GENERALLY 14-16C EVIDENT AT 700 MILLIBARS SHOULD LARGELY CAP THE ATMOSPHERE TO NEAR-SURFACE BASED STORM DEVELOPMENT...BUT NOT NECESSARILY TO ELEVATED ACTIVITY MAINLY MONDAY NIGHT. GIVEN THE PREDOMINANTLY DRY DEPICTION OF THE DAYTIME HOURS BY MODELS SUCH AS THE GFS...ECMWF AND 4KM WRF-NMM SIMULATED REFLECTIVITY...AM LARGELY DISCOUNTING THE 00Z/06 NAM RUNS WHICH SHOW A FAIR AMOUNT OF CONVECTIVE QPF DURING THE DAY. THIS MODEL HAS BEEN NOTORIOUSLY OVERDONE IN RECENT WEEKS ON SEVERAL OCCASIONS. THAT BEING SAID...PREVIOUS FORECAST INSERTED A SLIGHT CHANCE INTO FAR WESTERN/NORTHERN ZONES LATE IN THE AFTERNOON AND HAVE LET THAT RIDE FOR NOW IN CASE SOMETHING DOES MANAGE TO POP ALONG A SURFACE TROUGH AXIS CENTERED OVER WESTERN NEB. OTHERWISE...WILL CONTINUE TO MAINTAIN A SMATTERING OF SLIGHT POPS FOR THE MONDAY EVENING/NIGHT HOURS AS HAS BEEN IN THE FORECAST FOR DAYS NOW...ALTHOUGH CONFIDENCE IS NOT HIGH AS THE ECMWF IS DRY ALTHOUGH THE GFS HAS A DECENT SIGNAL FOR SLIGHT STORM POTENTIAL WITHIN A LOW LEVEL JET AXIS. AT THE SURFACE MONDAY...SOUTHERLY BREEZES OF GENERALLY 10-20 MPH TO THE EAST OF THE TROUGH AXIS WILL PREVAIL ACROSS MOST OF THE CWA...HELPING USHER IN HOTTER AIR BUT POTENTIALLY ALSO ALLOWING DEWPOINTS TO FALL A BIT LOWER THAN CURRENTLY FORECAST ESPECIALLY IN SOUTHERN ZONES. THE HEAT INDEX SITUATION WAS LARGELY DISCUSSED ABOVE...BUT AS FOR ACTUAL HIGHS MADE LITTLE CHANGE WITH MOST NEB ZONES INTO THE UPPER 90 AND MORE SO 100-102 IN KS ZONES. TUESDAY DAYTIME-TUESDAY NIGHT...THE EXPANSIVE RIDGE BUILDS NORTH MORE OVER COLORADO...WHICH ACTUALLY TURNS THE FLOW ALOFT OVER THE CWA TO MUCH MORE NORTHERLY VERSUS WESTERLY...AND BRINGS THE LOCAL AREA PRONE TO SOME FORCING FROM SHORTWAVE DISTURBANCES RIDING AROUND THE PERIPHERY OF THE RIDGE MAINLY ACROSS THE NORTHERN PLAINS INTO THE MIDWEST. MEANWHILE AT THE SURFACE...THESE DISTURBANCES WILL DRIVE A MODEST COLD FRONT SOUTHWARD ACROSS THE CWA DURING THE DAY...WHICH IS GENERALLY EXPECTED TO BISECT THE AREA DURING THE AFTERNOON WITH NORTHERLY BREEZES TO THE NORTH OF IT. DESPITE THIS FRONT MOVING IN...ANOTHER VERY HOT DAY IS CURRENTLY EXPECTED...AND HAVE ACTUAL HIGH TEMPS RANGING FROM MID 90S NORTH TO 100-102 AGAIN IN KS ZONES. THIS FRONT MAY ACTUALLY RESULT IN OVERALL-HIGHER DEWPOINTS AND THUS HEAT INDEX VALUES THAN MONDAY IN SOME AREAS. AS FOR POPS...LEFT SLIGHT CHANCES IN FAR EASTERN ZONES DURING THE AFTERNOON AND THEN FOR MUCH OF THE SOUTHEAST 1/2 OF THE CWA FOR TUESDAY NIGHT AS FORCING FROM THE AFOREMENTIONED SHORTWAVE AND LOW-LEVEL CONVERGENCE NEAR THE FRONT PASS THROUGH. WEDNESDAY DAYTIME-WEDNESDAY NIGHT...LITTLE CHANGE IN THE BIG PICTURE AS NORTH-NORTHWEST FLOW REMAINS IN PLACE OVER THE CWA TO THE EAST OF THE EXPANSIVE RIDGE THAT MIGHT RETROGRADE BACK SOUTHWEST A BIT TOWARD THE 4-CORNERS REGION. KEPT THE DAY VOID OF POPS...BUT KEPT WED NIGHT SLIGHT CHANCES ACROSS MUCH OF THE NEB CWA AS INTRODUCED BY THE PREVIOUS FORECAST...ALTHOUGH THE LATEST ECMWF BRINGS THESE POPS SOMEWHAT INTO QUESTION. AT THE SURFACE...FLOW TRANSITIONS FROM MORE EASTERLY TO SOUTHERLY...BUT SHOULD BE SEVERAL DEGREES COOLER THAN TUESDAY AND HAVE HIGHS RANGING FROM UPPER 80S NORTHEAST TO LOW-MID 90S SOUTHWEST. THURSDAY DAYTIME-THURSDAY NIGHT...ALTHOUGH THE RIDGE AXIS REMAINS CENTERED NEAR THE 4-CORNERS...IT FLATTENS SLIGHTLY ACROSS THE LOCAL AREA IN RESPONSE TO A SHORTWAVE TROUGH MOVING ALONG/NEAR THE CANADIAN BORDER. KEPT PREVIOUS SLIGHT POPS IN NORTHEAST ZONES DURING THE DAY...AND EXTENDED/EXPANDED THEM INTO THE NIGHT HOURS TO INCLUDE MUCH OF THE NORTHEAST HALF OF THE CWA. TEMP-WISE LOOKING SIMILAR TO WEDNESDAY RANGING FROM UPPER 80S NORTHEAST TO MID-90S SOUTHWEST. FRIDAY DAYTIME-FRIDAY NIGHT...SUBTLE HEIGHT FALLS CONTINUE ALOFT OVER THE LOCAL AREA AS THE RIDGE FLATTENS A BIT MORE/RETROGRADES SLIGHTLY WEST. WITH POTENTIALLY WEAKER CAPPING AND SOMEWHAT STRONGER WIND SHEAR AT LEAST THE POSSIBILITY OF SEVERE STORMS WOULD SEEM TO INCREASE A BIT...IF IN FACT ANY STORMS AFFECT THE AREA IN THE FIRST PLACE. KEPT THE DAY DRY FOR NOW PER PREVIOUS FORECAST AND ONLY SLIGHT POPS IN EASTERN ZONES FRI NIGHT. TEMPS PRELIMINARILY AIMED LOW 90S NORTHEAST TO UPPER 90S SOUTHWEST. SATURDAY DAYTIME...LITTLE CHANGE ALTHOUGH MODELS HINT AT A DECENT SHORTWAVE TROUGH POSSIBLY STARTING TO HEAD SOUTHEAST OUT OF THE DAKOTAS/CANADA BORDER AREA...BUT WITH FORCING IN THE LOCAL AREA QUESTIONABLE. WITH MODELS SHOWING DIFFERENT QPF SOLUTIONS...OPTED TO KEEP THIS VERY LAST PERIOD OF THE 7-DAY FORECAST DRY FOR NOW. TEMPS VERY PRELIMINARY AIMED UPPER 80S MOST NEB ZONES AND LOW-MID 90S KS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1229 PM CDT SUN JUL 20 2014 QUIET WEATHER FORECAST FOR THIS TAF PERIOD. LITTLE CHANGE EXPECTED WITH WINDS AS THE AREA REMAINS BETWEEN A TROUGH OF LOW PRESSURE OVER THE HIGH PLAINS AND HIGH PRESSURE OVER THE E/SERN CONUS. SOME GUSTS OVER 20 MPH WILL BE POSSIBLE THIS AFTERNOON...BUT SHOULD DIMINISH A BIT THIS EVENING/OVERNIGHT. LOW LEVEL STRATUS/MVFR CIGS WHICH DEVELOPED OVERNIGHT IS NOW PRIMARILY AFFECTING LOCATIONS JUST TO THE N/NE OF THE TERMINALS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...FAY LONG TERM...PFANNKUCH AVIATION...ADO
AREA FORECAST DISCUSSION
NWS HASTINGS NE
541 AM CDT SUN JUL 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 450 AM CDT SUN JUL 20 2014 THE MAIN CONCERN FOR THE SHORT TERM PERIODS IS TO WHAT EXTENT STRATUS WILL HAVE TEMPERATURES TODAY. THE PATTERN ALOFT FEATURED NORTHWEST FLOW ACROSS THE INTERIOR CONUS...WITH AN UPPER RIDGE AXIS BUILDING NORTH FM THE FOUR CORNERS REGION. FARTHER NORTH ACROSS THE SOUTHERN CANADIAN PROVINCES AND THE NORTHERN CONUS THE FLOW WAS MORE ZONAL. AT THE SURFACE...LOW PRESSURE EXTENDED ALONG THE HIGH PLAINS WITH SOUTHERLY LLVL FLOW IN PLACE ACROSS OUR REGION. MOISTURE HAS MADE A RETURN WITH SFC DPS AVERAGING LOW/MID 60S. SIMILAR TO THE LAST COUPLE OF NIGHTS...WE ARE LOOKING THE DEVELOPMENT OF STRATUS AGAIN THIS MORNING. THE STRATUS CLOUDS INITIATED ALONG OUR WESTERN CWA BORDER AND THE AREA OF STRATUS WAS EXPANDING ACROSS WESTERN AND CENTRAL NEBRASKA. THE HRRR SUGGESTS THE MAIN AREA OF STRATUS WILL SPREAD EASTWARD FOR A FEW HOURS AND THEN RAPIDLY ERODE AFTER DAYBREAK WHEREAS RAP/NAM SUGGEST THE AREAS WILL EXPAND EASTWARD AND ERODE W/E TODAY. WILL CONTINUE TO MONITOR TRENDS OF STRATUS DEVELOPMENT AND ANY POTENTIAL FOR VSBY RESTRICTIONS OR DRIZZLE. GIVEN MODEL PERFORMANCE THE LAST COUPLE OF DAYS...FORECAST MODELS HAVE BEEN TOO QUICK IN ERODING THE LOW CLOUDS AND THE CLOUD COVER HAS KEPT HIGH TEMPS SEVERAL DEGREES COOLER THAN FORECAST. WITH THIS IN MIND...THE TEMPERATURE FORECAST TODAY WILL BE DEPENDENT UPON CLOUD COVER. THE UPPER RIDGE AXIS WILL BUILD NORTH AND EASTWARD ACROSS THE CENTRAL PLAINS TODAY AND THE AIRMASS HEATS UP. H85 TEMPS ARE PROGGED TO REACH THE LOW 20S CELSIUS ACROSS OUR EASTERN ZONES AND WILL BE NEAR 30 CELSIUS IN THE WEST. FULLY MIXED THIS WILL LEAD TO HIGHS FROM THE UPPER 80S TO WELL INTO THE 90S...BUT WITH THE DEVELOPING LOW CLOUD COVER AND UNCERTAINTY IN HOW LONG CLOUDS WILL LINGER AND WITH HIGHER DPS IN PLACE...OPTED TO STAY RELATIVELY CONSERVATIVE WITH TEMPS THIS AFTERNOON. HAVE RANGED HIGHS FROM THE UPPER 80S IN OUR EAST...TO NEAR 100F IN THE WEST. BELIEVE THERE WILL BE A DECENT GRADIENT IN TEMPS DUE TO HIGHER DPS IN OUR NE AND WHERE THERE IS THE POTENTIAL FOR CLOUDS TO LINGER LONGER TODAY. FARTHER WEST...MODELS INDICATE DRIER AIR ADVECTING IN WITH DPS IN THE UPPER 50S TO NEAR 60 PUSHING EAST WITH SFC BOUNDARY WHICH WILL AID IN WARMING TEMPS...AND STRATUS DOES LOOK TO ERODE QUICKER FOR OUR SW COUNTIES. CONVECTIVE TEMPS ARE NEAR 100F AND COULD SEE SOME CU TRY TO FORM IN THE AFTN AGAIN IN OUR SW CWA. WITH THE MORE CONSERVATIVE HIGH TEMP FORECAST TODAY...HEAT INDEX VALUES NEAR 100F ARE MORE FAVORABLE FOR OUR SOUTHWEST ZONES WHERE HIGHER TEMPS ARE EXPECTED. AT SOME POINT IN THIS PATTERN THE HEAT WILL TURN ON...BUT WE NEED TO BE FREE FROM THE LOW CLOUDS. FOR TONIGHT...OVERALL DRY CONDITIONS ARE EXPECTED. THERE IS A SUBTLE SHORTWAVE THAT IS PROGGED TO MOVE THRU BUT CHCS LOOK RATHER SLIM FOR CONVECTIVE DEVELOPMENT WITH WARM MID LEVEL TEMPS/CAPPING. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 450 AM CDT SUN JUL 20 2014 AS HAS ALREADY BEEN WIDELY-ADVERTISED FOR A FEW DAYS NOW...THE MOST IMMEDIATE AND CURRENTLY-PRIMARY FOCUS OF THIS 6-DAY PERIOD REVOLVES AROUND CONSECUTIVE AFTERNOONS OF FORECASTED 100+ DEGREE HEAT INDEX VALUES ON MONDAY-TUESDAY...WITH A DECENT CHUNK OF MAINLY THE EASTERN 1/2 OF THE CWA CURRENTLY ADVERTISED TO OBSERVE AT LEAST BRIEF PERIODS OF ADVISORY-CRITERIA HEAT INDEX READINGS OF 105-109 DEGREES. BEYOND TUESDAY...IT IS EXPECTED TO REMAIN SEASONABLY WARM/HOT THE REMAINDER OF THE WEEK...BUT NOTHING THAT APPEARS TO SUPPORT HEAT ADVISORY CONDITIONS...ALTHOUGH IF CURRENT TRENDS HOLD WILL HAVE TO KEEP AN EYE ON MAINLY KS ZONES FOR A POSSIBLE BRUSH WITH NEAR-ADVISORY HEAT INDEX AROUND 100 DEGREES ON FRIDAY. ALTHOUGH THE OFFICIAL FORECAST FAIRLY-STRONGLY SUPPORTS HEAT ADVISORY ISSUANCE FOR MUCH OF THE CWA ON BOTH MONDAY AND TUESDAY...WANT TO MAKE IT CLEAR HERE THAT THE TEMPERATURE TRENDS OF THE PAST FEW DAYS (FALLING SEVERAL DEGREES SHORT OF FORECAST HIGHS IN MANY AREAS) LENDS SOME UNCERTAINTY REGARDING WHETHER MODELS AND THE CURRENT FORECAST MAY IN FACT BE OVER-DOING THE HEAT SITUATION SLIGHTLY. IN OTHER WORDS...WHILE ITS A FOREGONE CONCLUSION THAT IT WILL IN FACT BE QUITE HOT ESPECIALLY COMPARED TO THE RECENT COOL STRETCH...THERE ARE STILL SOME QUESTIONS REGARDING WHETHER MAX HEAT INDEX VALUES WILL AVERAGE CLOSER TO 100 DEGREES WHICH IS NOT ALL THAT UNCOMMON BY LATE-JULY STANDARDS...OR MORE SO INTO THE MORE HAZARDOUS 105+ TERRITORY. AS A RESULT OF THESE UNCERTAINTIES...HAVE COORDINATED WITH MOST SURROUNDING WFOS TO HOLD OFF ON ANY ADVISORIES FOR MONDAY AFTERNOON FOR NOW (LET ALONE TUESDAY)...AND THUS ALLOW THE NEXT 1-2 SHIFTS TO HOPEFULLY GAIN A BIT MORE CONFIDENCE IN THE MAGNITUDE OF THIS HEAT BLAST. AS FOR SHOWER/THUNDERSTORM CHANCES THROUGH THIS 6-DAY PERIOD...THE NUMBER OF 12-HOUR PERIODS WITH SLIGHT CHANCES HAS INCREASED A BIT VERSUS 24 HOURS AGO...BUT THE KEY WORD THERE IS SLIGHT CHANCES...AND CURRENTLY HAVE NO POPS ABOVE 20 PERCENT TERRITORY GIVEN CONSIDERABLE UNCERTAINTY IN MODEL DIFFERENCES AND ALSO WHETHER OR NOT FAIRLY STRONG CAPPING THROUGH MUCH OF THIS TIME FRAME CAN BE OVERCOME. ALTHOUGH THE DEGREE OF INSTABILITY ALONE MAKES IT ALMOST IMPOSSIBLE TO RULE OUT AT LEAST ON ISOLATED STRONG-SEVERE STORM DURING SEVERAL PERIODS...THE PREDOMINANTLY SUBTLE FORCING AND GENERALLY WEAKER DEEP-LAYER SHEAR REGIME THROUGH MOST OF THE WEEK (GENERALLY LESS THAN 30KT) LENDS ITSELF TO CONSIDERABLE UNCERTAINTY REGARDING WHICH (IF ANY) PERIODS ARE WORTHY OF A FORMAL SEVERE MENTION IN THE HAZARDOUS WEATHER OUTLOOK (HWOGID). AT LEAST FOR ONE MORE FORECAST CYCLE...WILL KEEP OUT A FORMAL SEVERE MENTION DESPITE THE FACT THAT THE STORM PREDICTION CENTER BARELY CLIPS SMALL PORTIONS OF THE CWA WITH LOW-END 5 PERCENT SEVERE PROBS ON BOTH THE DAY 2-3 OUTLOOKS. ALTHOUGH NOT GUARANTEED TO STAY THIS WAY BY ANY MEANS...ONLY 3 OF THE 11 LONG TERM FORECAST PERIODS ARE COMPLETELY VOID OF SLIGHT POPS: WEDNESDAY DAYTIME...FRIDAY DAYTIME AND SATURDAY DAYTIME. GETTING INTO SOME MORE METEOROLOGICAL DETAIL AND TAKING IT IN MAINLY 24-HOUR BLOCKS... MONDAY DAYTIME-MONDAY NIGHT...THE BIG STORY IN THE MID-UPPER LEVELS INVOLVES HEIGHT RISES ASSOCIATED WITH THE INCREASING-LOCAL INFLUENCE OF AN EXPANSIVE HIGH PRESSURE RIDGE ENCOMPASSING MUCH OF THE SOUTHERN HALF OF THE CONUS BUT GENERALLY REMAINING CENTERED OVER NEW MEXICO. UNDER THIS RIDGE AXIS...WARM MID LEVEL TEMPS OF GENERALLY 14-16C EVIDENT AT 700 MILLIBARS SHOULD LARGELY CAP THE ATMOSPHERE TO NEAR-SURFACE BASED STORM DEVELOPMENT...BUT NOT NECESSARILY TO ELEVATED ACTIVITY MAINLY MONDAY NIGHT. GIVEN THE PREDOMINANTLY DRY DEPICTION OF THE DAYTIME HOURS BY MODELS SUCH AS THE GFS...ECMWF AND 4KM WRF-NMM SIMULATED REFLECTIVITY...AM LARGELY DISCOUNTING THE 00Z/06 NAM RUNS WHICH SHOW A FAIR AMOUNT OF CONVECTIVE QPF DURING THE DAY. THIS MODEL HAS BEEN NOTORIOUSLY OVERDONE IN RECENT WEEKS ON SEVERAL OCCASIONS. THAT BEING SAID...PREVIOUS FORECAST INSERTED A SLIGHT CHANCE INTO FAR WESTERN/NORTHERN ZONES LATE IN THE AFTERNOON AND HAVE LET THAT RIDE FOR NOW IN CASE SOMETHING DOES MANAGE TO POP ALONG A SURFACE TROUGH AXIS CENTERED OVER WESTERN NEB. OTHERWISE...WILL CONTINUE TO MAINTAIN A SMATTERING OF SLIGHT POPS FOR THE MONDAY EVENING/NIGHT HOURS AS HAS BEEN IN THE FORECAST FOR DAYS NOW...ALTHOUGH CONFIDENCE IS NOT HIGH AS THE ECMWF IS DRY ALTHOUGH THE GFS HAS A DECENT SIGNAL FOR SLIGHT STORM POTENTIAL WITHIN A LOW LEVEL JET AXIS. AT THE SURFACE MONDAY...SOUTHERLY BREEZES OF GENERALLY 10-20 MPH TO THE EAST OF THE TROUGH AXIS WILL PREVAIL ACROSS MOST OF THE CWA...HELPING USHER IN HOTTER AIR BUT POTENTIALLY ALSO ALLOWING DEWPOINTS TO FALL A BIT LOWER THAN CURRENTLY FORECAST ESPECIALLY IN SOUTHERN ZONES. THE HEAT INDEX SITUATION WAS LARGELY DISCUSSED ABOVE...BUT AS FOR ACTUAL HIGHS MADE LITTLE CHANGE WITH MOST NEB ZONES INTO THE UPPER 90 AND MORE SO 100-102 IN KS ZONES. TUESDAY DAYTIME-TUESDAY NIGHT...THE EXPANSIVE RIDGE BUILDS NORTH MORE OVER COLORADO...WHICH ACTUALLY TURNS THE FLOW ALOFT OVER THE CWA TO MUCH MORE NORTHERLY VERSUS WESTERLY...AND BRINGS THE LOCAL AREA PRONE TO SOME FORCING FROM SHORTWAVE DISTURBANCES RIDING AROUND THE PERIPHERY OF THE RIDGE MAINLY ACROSS THE NORTHERN PLAINS INTO THE MIDWEST. MEANWHILE AT THE SURFACE...THESE DISTURBANCES WILL DRIVE A MODEST COLD FRONT SOUTHWARD ACROSS THE CWA DURING THE DAY...WHICH IS GENERALLY EXPECTED TO BISECT THE AREA DURING THE AFTERNOON WITH NORTHERLY BREEZES TO THE NORTH OF IT. DESPITE THIS FRONT MOVING IN...ANOTHER VERY HOT DAY IS CURRENTLY EXPECTED...AND HAVE ACTUAL HIGH TEMPS RANGING FROM MID 90S NORTH TO 100-102 AGAIN IN KS ZONES. THIS FRONT MAY ACTUALLY RESULT IN OVERALL-HIGHER DEWPOINTS AND THUS HEAT INDEX VALUES THAN MONDAY IN SOME AREAS. AS FOR POPS...LEFT SLIGHT CHANCES IN FAR EASTERN ZONES DURING THE AFTERNOON AND THEN FOR MUCH OF THE SOUTHEAST 1/2 OF THE CWA FOR TUESDAY NIGHT AS FORCING FROM THE AFOREMENTIONED SHORTWAVE AND LOW-LEVEL CONVERGENCE NEAR THE FRONT PASS THROUGH. WEDNESDAY DAYTIME-WEDNESDAY NIGHT...LITTLE CHANGE IN THE BIG PICTURE AS NORTH-NORTHWEST FLOW REMAINS IN PLACE OVER THE CWA TO THE EAST OF THE EXPANSIVE RIDGE THAT MIGHT RETROGRADE BACK SOUTHWEST A BIT TOWARD THE 4-CORNERS REGION. KEPT THE DAY VOID OF POPS...BUT KEPT WED NIGHT SLIGHT CHANCES ACROSS MUCH OF THE NEB CWA AS INTRODUCED BY THE PREVIOUS FORECAST...ALTHOUGH THE LATEST ECMWF BRINGS THESE POPS SOMEWHAT INTO QUESTION. AT THE SURFACE...FLOW TRANSITIONS FROM MORE EASTERLY TO SOUTHERLY...BUT SHOULD BE SEVERAL DEGREES COOLER THAN TUESDAY AND HAVE HIGHS RANGING FROM UPPER 80S NORTHEAST TO LOW-MID 90S SOUTHWEST. THURSDAY DAYTIME-THURSDAY NIGHT...ALTHOUGH THE RIDGE AXIS REMAINS CENTERED NEAR THE 4-CORNERS...IT FLATTENS SLIGHTLY ACROSS THE LOCAL AREA IN RESPONSE TO A SHORTWAVE TROUGH MOVING ALONG/NEAR THE CANADIAN BORDER. KEPT PREVIOUS SLIGHT POPS IN NORTHEAST ZONES DURING THE DAY...AND EXTENDED/EXPANDED THEM INTO THE NIGHT HOURS TO INCLUDE MUCH OF THE NORTHEAST HALF OF THE CWA. TEMP-WISE LOOKING SIMILAR TO WEDNESDAY RANGING FROM UPPER 80S NORTHEAST TO MID-90S SOUTHWEST. FRIDAY DAYTIME-FRIDAY NIGHT...SUBTLE HEIGHT FALLS CONTINUE ALOFT OVER THE LOCAL AREA AS THE RIDGE FLATTENS A BIT MORE/RETROGRADES SLIGHTLY WEST. WITH POTENTIALLY WEAKER CAPPING AND SOMEWHAT STRONGER WIND SHEAR AT LEAST THE POSSIBILITY OF SEVERE STORMS WOULD SEEM TO INCREASE A BIT...IF IN FACT ANY STORMS AFFECT THE AREA IN THE FIRST PLACE. KEPT THE DAY DRY FOR NOW PER PREVIOUS FORECAST AND ONLY SLIGHT POPS IN EASTERN ZONES FRI NIGHT. TEMPS PRELIMINARILY AIMED LOW 90S NORTHEAST TO UPPER 90S SOUTHWEST. SATURDAY DAYTIME...LITTLE CHANGE ALTHOUGH MODELS HINT AT A DECENT SHORTWAVE TROUGH POSSIBLY STARTING TO HEAD SOUTHEAST OUT OF THE DAKOTAS/CANADA BORDER AREA...BUT WITH FORCING IN THE LOCAL AREA QUESTIONABLE. WITH MODELS SHOWING DIFFERENT QPF SOLUTIONS...OPTED TO KEEP THIS VERY LAST PERIOD OF THE 7-DAY FORECAST DRY FOR NOW. TEMPS VERY PRELIMINARY AIMED UPPER 80S MOST NEB ZONES AND LOW-MID 90S KS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 532 AM CDT SUN JUL 20 2014 STRATUS CONTINUES TO BE THE MAIN CONCERN FOR THE TAFS THIS MORNING. AN AREA OF STRATUS DEVELOPED OVERNIGHT AND WAS EXPANDING TO THE EAST EARLY THIS MORNING. THE LOW CLOUDS HAVE REACHED KEAR AND WERE HEADING TOWARD KGRI. CIGS WITHIN THE STRATUS RANGE FROM LIFR TO MVFR. KEAR SHOULD SEE LOWER CIGS THAN KGRI. THERE IS AN OUTSIDE CHC FOR A VSBY RESTRICTION BUT IN GENERAL THE LOWER VSBYS IN BR SHOULD REMAIN WEST OF THE TERMINALS. MODELS ARE CONSISTENT IN RAPIDLY ERODING THE STRATUS THIS MORNING BUT CONFIDENCE IS NOT HIGH AS MODELS HAVE BEEN TOO QUICK WITH THIS THE LAST COUPLE OF DAYS. BUT IF TRENDS HOLD...LOOK FOR CLOUDS TO SCATTER THIS MORNING. WINDS WILL REMAIN FROM A SOUTHERLY DIRECTION WITH AN INCREASE IN WIND SPEEDS TO AROUND 15KTS WITH HIGHER GUSTS POSSIBLE IN THE AFTN. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...FAY LONG TERM...PFANNKUCH AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
451 AM CDT SUN JUL 20 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 450 AM CDT SUN JUL 20 2014 THE MAIN CONCERN FOR THE SHORT TERM PERIODS IS TO WHAT EXTENT STRATUS WILL HAVE TEMPERATURES TODAY. THE PATTERN ALOFT FEATURED NORTHWEST FLOW ACROSS THE INTERIOR CONUS...WITH AN UPPER RIDGE AXIS BUILDING NORTH FM THE FOUR CORNERS REGION. FARTHER NORTH ACROSS THE SOUTHERN CANADIAN PROVINCES AND THE NORTHERN CONUS THE FLOW WAS MORE ZONAL. AT THE SURFACE...LOW PRESSURE EXTENDED ALONG THE HIGH PLAINS WITH SOUTHERLY LLVL FLOW IN PLACE ACROSS OUR REGION. MOISTURE HAS MADE A RETURN WITH SFC DPS AVERAGING LOW/MID 60S. SIMILAR TO THE LAST COUPLE OF NIGHTS...WE ARE LOOKING THE DEVELOPMENT OF STRATUS AGAIN THIS MORNING. THE STRATUS CLOUDS INITIATED ALONG OUR WESTERN CWA BORDER AND THE AREA OF STRATUS WAS EXPANDING ACROSS WESTERN AND CENTRAL NEBRASKA. THE HRRR SUGGESTS THE MAIN AREA OF STRATUS WILL SPREAD EASTWARD FOR A FEW HOURS AND THEN RAPIDLY ERODE AFTER DAYBREAK WHEREAS RAP/NAM SUGGEST THE AREAS WILL EXPAND EASTWARD AND ERODE W/E TODAY. WILL CONTINUE TO MONITOR TRENDS OF STRATUS DEVELOPMENT AND ANY POTENTIAL FOR VSBY RESTRICTIONS OR DRIZZLE. GIVEN MODEL PERFORMANCE THE LAST COUPLE OF DAYS...FORECAST MODELS HAVE BEEN TOO QUICK IN ERODING THE LOW CLOUDS AND THE CLOUD COVER HAS KEPT HIGH TEMPS SEVERAL DEGREES COOLER THAN FORECAST. WITH THIS IN MIND...THE TEMPERATURE FORECAST TODAY WILL BE DEPENDENT UPON CLOUD COVER. THE UPPER RIDGE AXIS WILL BUILD NORTH AND EASTWARD ACROSS THE CENTRAL PLAINS TODAY AND THE AIRMASS HEATS UP. H85 TEMPS ARE PROGGED TO REACH THE LOW 20S CELSIUS ACROSS OUR EASTERN ZONES AND WILL BE NEAR 30 CELSIUS IN THE WEST. FULLY MIXED THIS WILL LEAD TO HIGHS FROM THE UPPER 80S TO WELL INTO THE 90S...BUT WITH THE DEVELOPING LOW CLOUD COVER AND UNCERTAINTY IN HOW LONG CLOUDS WILL LINGER AND WITH HIGHER DPS IN PLACE...OPTED TO STAY RELATIVELY CONSERVATIVE WITH TEMPS THIS AFTERNOON. HAVE RANGED HIGHS FROM THE UPPER 80S IN OUR EAST...TO NEAR 100F IN THE WEST. BELIEVE THERE WILL BE A DECENT GRADIENT IN TEMPS DUE TO HIGHER DPS IN OUR NE AND WHERE THERE IS THE POTENTIAL FOR CLOUDS TO LINGER LONGER TODAY. FARTHER WEST...MODELS INDICATE DRIER AIR ADVECTING IN WITH DPS IN THE UPPER 50S TO NEAR 60 PUSHING EAST WITH SFC BOUNDARY WHICH WILL AID IN WARMING TEMPS...AND STRATUS DOES LOOK TO ERODE QUICKER FOR OUR SW COUNTIES. CONVECTIVE TEMPS ARE NEAR 100F AND COULD SEE SOME CU TRY TO FORM IN THE AFTN AGAIN IN OUR SW CWA. WITH THE MORE CONSERVATIVE HIGH TEMP FORECAST TODAY...HEAT INDEX VALUES NEAR 100F ARE MORE FAVORABLE FOR OUR SOUTHWEST ZONES WHERE HIGHER TEMPS ARE EXPECTED. AT SOME POINT IN THIS PATTERN THE HEAT WILL TURN ON...BUT WE NEED TO BE FREE FROM THE LOW CLOUDS. FOR TONIGHT...OVERALL DRY CONDITIONS ARE EXPECTED. THERE IS A SUBTLE SHORTWAVE THAT IS PROGGED TO MOVE THRU BUT CHCS LOOK RATHER SLIM FOR CONVECTIVE DEVELOPMENT WITH WARM MID LEVEL TEMPS/CAPPING. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 450 AM CDT SUN JUL 20 2014 AS HAS ALREADY BEEN WIDELY-ADVERTISED FOR A FEW DAYS NOW...THE MOST IMMEDIATE AND CURRENTLY-PRIMARY FOCUS OF THIS 6-DAY PERIOD REVOLVES AROUND CONSECUTIVE AFTERNOONS OF FORECASTED 100+ DEGREE HEAT INDEX VALUES ON MONDAY-TUESDAY...WITH A DECENT CHUNK OF MAINLY THE EASTERN 1/2 OF THE CWA CURRENTLY ADVERTISED TO OBSERVE AT LEAST BRIEF PERIODS OF ADVISORY-CRITERIA HEAT INDEX READINGS OF 105-109 DEGREES. BEYOND TUESDAY...IT IS EXPECTED TO REMAIN SEASONABLY WARM/HOT THE REMAINDER OF THE WEEK...BUT NOTHING THAT APPEARS TO SUPPORT HEAT ADVISORY CONDITIONS...ALTHOUGH IF CURRENT TRENDS HOLD WILL HAVE TO KEEP AN EYE ON MAINLY KS ZONES FOR A POSSIBLE BRUSH WITH NEAR-ADVISORY HEAT INDEX AROUND 100 DEGREES ON FRIDAY. ALTHOUGH THE OFFICIAL FORECAST FAIRLY-STRONGLY SUPPORTS HEAT ADVISORY ISSUANCE FOR MUCH OF THE CWA ON BOTH MONDAY AND TUESDAY...WANT TO MAKE IT CLEAR HERE THAT THE TEMPERATURE TRENDS OF THE PAST FEW DAYS (FALLING SEVERAL DEGREES SHORT OF FORECAST HIGHS IN MANY AREAS) LENDS SOME UNCERTAINTY REGARDING WHETHER MODELS AND THE CURRENT FORECAST MAY IN FACT BE OVER-DOING THE HEAT SITUATION SLIGHTLY. IN OTHER WORDS...WHILE ITS A FOREGONE CONCLUSION THAT IT WILL IN FACT BE QUITE HOT ESPECIALLY COMPARED TO THE RECENT COOL STRETCH...THERE ARE STILL SOME QUESTIONS REGARDING WHETHER MAX HEAT INDEX VALUES WILL AVERAGE CLOSER TO 100 DEGREES WHICH IS NOT ALL THAT UNCOMMON BY LATE-JULY STANDARDS...OR MORE SO INTO THE MORE HAZARDOUS 105+ TERRITORY. AS A RESULT OF THESE UNCERTAINTIES...HAVE COORDINATED WITH MOST SURROUNDING WFOS TO HOLD OFF ON ANY ADVISORIES FOR MONDAY AFTERNOON FOR NOW (LET ALONE TUESDAY)...AND THUS ALLOW THE NEXT 1-2 SHIFTS TO HOPEFULLY GAIN A BIT MORE CONFIDENCE IN THE MAGNITUDE OF THIS HEAT BLAST. AS FOR SHOWER/THUNDERSTORM CHANCES THROUGH THIS 6-DAY PERIOD...THE NUMBER OF 12-HOUR PERIODS WITH SLIGHT CHANCES HAS INCREASED A BIT VERSUS 24 HOURS AGO...BUT THE KEY WORD THERE IS SLIGHT CHANCES...AND CURRENTLY HAVE NO POPS ABOVE 20 PERCENT TERRITORY GIVEN CONSIDERABLE UNCERTAINTY IN MODEL DIFFERENCES AND ALSO WHETHER OR NOT FAIRLY STRONG CAPPING THROUGH MUCH OF THIS TIME FRAME CAN BE OVERCOME. ALTHOUGH THE DEGREE OF INSTABILITY ALONE MAKES IT ALMOST IMPOSSIBLE TO RULE OUT AT LEAST ON ISOLATED STRONG-SEVERE STORM DURING SEVERAL PERIODS...THE PREDOMINANTLY SUBTLE FORCING AND GENERALLY WEAKER DEEP-LAYER SHEAR REGIME THROUGH MOST OF THE WEEK (GENERALLY LESS THAN 30KT) LENDS ITSELF TO CONSIDERABLE UNCERTAINTY REGARDING WHICH (IF ANY) PERIODS ARE WORTHY OF A FORMAL SEVERE MENTION IN THE HAZARDOUS WEATHER OUTLOOK (HWOGID). AT LEAST FOR ONE MORE FORECAST CYCLE...WILL KEEP OUT A FORMAL SEVERE MENTION DESPITE THE FACT THAT THE STORM PREDICTION CENTER BARELY CLIPS SMALL PORTIONS OF THE CWA WITH LOW-END 5 PERCENT SEVERE PROBS ON BOTH THE DAY 2-3 OUTLOOKS. ALTHOUGH NOT GUARANTEED TO STAY THIS WAY BY ANY MEANS...ONLY 3 OF THE 11 LONG TERM FORECAST PERIODS ARE COMPLETELY VOID OF SLIGHT POPS: WEDNESDAY DAYTIME...FRIDAY DAYTIME AND SATURDAY DAYTIME. GETTING INTO SOME MORE METEOROLOGICAL DETAIL AND TAKING IT IN MAINLY 24-HOUR BLOCKS... MONDAY DAYTIME-MONDAY NIGHT...THE BIG STORY IN THE MID-UPPER LEVELS INVOLVES HEIGHT RISES ASSOCIATED WITH THE INCREASING-LOCAL INFLUENCE OF AN EXPANSIVE HIGH PRESSURE RIDGE ENCOMPASSING MUCH OF THE SOUTHERN HALF OF THE CONUS BUT GENERALLY REMAINING CENTERED OVER NEW MEXICO. UNDER THIS RIDGE AXIS...WARM MID LEVEL TEMPS OF GENERALLY 14-16C EVIDENT AT 700 MILLIBARS SHOULD LARGELY CAP THE ATMOSPHERE TO NEAR-SURFACE BASED STORM DEVELOPMENT...BUT NOT NECESSARILY TO ELEVATED ACTIVITY MAINLY MONDAY NIGHT. GIVEN THE PREDOMINANTLY DRY DEPICTION OF THE DAYTIME HOURS BY MODELS SUCH AS THE GFS...ECMWF AND 4KM WRF-NMM SIMULATED REFLECTIVITY...AM LARGELY DISCOUNTING THE 00Z/06 NAM RUNS WHICH SHOW A FAIR AMOUNT OF CONVECTIVE QPF DURING THE DAY. THIS MODEL HAS BEEN NOTORIOUSLY OVERDONE IN RECENT WEEKS ON SEVERAL OCCASIONS. THAT BEING SAID...PREVIOUS FORECAST INSERTED A SLIGHT CHANCE INTO FAR WESTERN/NORTHERN ZONES LATE IN THE AFTERNOON AND HAVE LET THAT RIDE FOR NOW IN CASE SOMETHING DOES MANAGE TO POP ALONG A SURFACE TROUGH AXIS CENTERED OVER WESTERN NEB. OTHERWISE...WILL CONTINUE TO MAINTAIN A SMATTERING OF SLIGHT POPS FOR THE MONDAY EVENING/NIGHT HOURS AS HAS BEEN IN THE FORECAST FOR DAYS NOW...ALTHOUGH CONFIDENCE IS NOT HIGH AS THE ECMWF IS DRY ALTHOUGH THE GFS HAS A DECENT SIGNAL FOR SLIGHT STORM POTENTIAL WITHIN A LOW LEVEL JET AXIS. AT THE SURFACE MONDAY...SOUTHERLY BREEZES OF GENERALLY 10-20 MPH TO THE EAST OF THE TROUGH AXIS WILL PREVAIL ACROSS MOST OF THE CWA...HELPING USHER IN HOTTER AIR BUT POTENTIALLY ALSO ALLOWING DEWPOINTS TO FALL A BIT LOWER THAN CURRENTLY FORECAST ESPECIALLY IN SOUTHERN ZONES. THE HEAT INDEX SITUATION WAS LARGELY DISCUSSED ABOVE...BUT AS FOR ACTUAL HIGHS MADE LITTLE CHANGE WITH MOST NEB ZONES INTO THE UPPER 90 AND MORE SO 100-102 IN KS ZONES. TUESDAY DAYTIME-TUESDAY NIGHT...THE EXPANSIVE RIDGE BUILDS NORTH MORE OVER COLORADO...WHICH ACTUALLY TURNS THE FLOW ALOFT OVER THE CWA TO MUCH MORE NORTHERLY VERSUS WESTERLY...AND BRINGS THE LOCAL AREA PRONE TO SOME FORCING FROM SHORTWAVE DISTURBANCES RIDING AROUND THE PERIPHERY OF THE RIDGE MAINLY ACROSS THE NORTHERN PLAINS INTO THE MIDWEST. MEANWHILE AT THE SURFACE...THESE DISTURBANCES WILL DRIVE A MODEST COLD FRONT SOUTHWARD ACROSS THE CWA DURING THE DAY...WHICH IS GENERALLY EXPECTED TO BISECT THE AREA DURING THE AFTERNOON WITH NORTHERLY BREEZES TO THE NORTH OF IT. DESPITE THIS FRONT MOVING IN...ANOTHER VERY HOT DAY IS CURRENTLY EXPECTED...AND HAVE ACTUAL HIGH TEMPS RANGING FROM MID 90S NORTH TO 100-102 AGAIN IN KS ZONES. THIS FRONT MAY ACTUALLY RESULT IN OVERALL-HIGHER DEWPOINTS AND THUS HEAT INDEX VALUES THAN MONDAY IN SOME AREAS. AS FOR POPS...LEFT SLIGHT CHANCES IN FAR EASTERN ZONES DURING THE AFTERNOON AND THEN FOR MUCH OF THE SOUTHEAST 1/2 OF THE CWA FOR TUESDAY NIGHT AS FORCING FROM THE AFOREMENTIONED SHORTWAVE AND LOW-LEVEL CONVERGENCE NEAR THE FRONT PASS THROUGH. WEDNESDAY DAYTIME-WEDNESDAY NIGHT...LITTLE CHANGE IN THE BIG PICTURE AS NORTH-NORTHWEST FLOW REMAINS IN PLACE OVER THE CWA TO THE EAST OF THE EXPANSIVE RIDGE THAT MIGHT RETROGRADE BACK SOUTHWEST A BIT TOWARD THE 4-CORNERS REGION. KEPT THE DAY VOID OF POPS...BUT KEPT WED NIGHT SLIGHT CHANCES ACROSS MUCH OF THE NEB CWA AS INTRODUCED BY THE PREVIOUS FORECAST...ALTHOUGH THE LATEST ECMWF BRINGS THESE POPS SOMEWHAT INTO QUESTION. AT THE SURFACE...FLOW TRANSITIONS FROM MORE EASTERLY TO SOUTHERLY...BUT SHOULD BE SEVERAL DEGREES COOLER THAN TUESDAY AND HAVE HIGHS RANGING FROM UPPER 80S NORTHEAST TO LOW-MID 90S SOUTHWEST. THURSDAY DAYTIME-THURSDAY NIGHT...ALTHOUGH THE RIDGE AXIS REMAINS CENTERED NEAR THE 4-CORNERS...IT FLATTENS SLIGHTLY ACROSS THE LOCAL AREA IN RESPONSE TO A SHORTWAVE TROUGH MOVING ALONG/NEAR THE CANADIAN BORDER. KEPT PREVIOUS SLIGHT POPS IN NORTHEAST ZONES DURING THE DAY...AND EXTENDED/EXPANDED THEM INTO THE NIGHT HOURS TO INCLUDE MUCH OF THE NORTHEAST HALF OF THE CWA. TEMP-WISE LOOKING SIMILAR TO WEDNESDAY RANGING FROM UPPER 80S NORTHEAST TO MID-90S SOUTHWEST. FRIDAY DAYTIME-FRIDAY NIGHT...SUBTLE HEIGHT FALLS CONTINUE ALOFT OVER THE LOCAL AREA AS THE RIDGE FLATTENS A BIT MORE/RETROGRADES SLIGHTLY WEST. WITH POTENTIALLY WEAKER CAPPING AND SOMEWHAT STRONGER WIND SHEAR AT LEAST THE POSSIBILITY OF SEVERE STORMS WOULD SEEM TO INCREASE A BIT...IF IN FACT ANY STORMS AFFECT THE AREA IN THE FIRST PLACE. KEPT THE DAY DRY FOR NOW PER PREVIOUS FORECAST AND ONLY SLIGHT POPS IN EASTERN ZONES FRI NIGHT. TEMPS PRELIMINARILY AIMED LOW 90S NORTHEAST TO UPPER 90S SOUTHWEST. SATURDAY DAYTIME...LITTLE CHANGE ALTHOUGH MODELS HINT AT A DECENT SHORTWAVE TROUGH POSSIBLY STARTING TO HEAD SOUTHEAST OUT OF THE DAKOTAS/CANADA BORDER AREA...BUT WITH FORCING IN THE LOCAL AREA QUESTIONABLE. WITH MODELS SHOWING DIFFERENT QPF SOLUTIONS...OPTED TO KEEP THIS VERY LAST PERIOD OF THE 7-DAY FORECAST DRY FOR NOW. TEMPS VERY PRELIMINARY AIMED UPPER 80S MOST NEB ZONES AND LOW-MID 90S KS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1151 PM CDT SAT JUL 19 2014 MAIN CONCERN FOR THE TAF PERIOD IS WHETHER OR NOT STRATUS WILL REDEVELOP TOWARD DAYBREAK. MODELS HAVE NOT HAVE THE BEST HANDLE ON THE STRATUS THE PAST COUPLE OF NIGHTS/MORNINGS ESPECIALLY WITH HOW LONG THE LOW CLOUDS WILL PERSIST. THE HRRR AGAIN DEVELOPS STRATUS TOWARDS MORNING...WITH THE LOW CLOUDS DEVELOPING ACROSS OUR WESTERN CWA WHEREAS THE NAM LLVL RH PROGS INDICATE THE BETTER POTENTIAL TO THE EAST. HAVE FOLLOWED CLOSER TO THE HRRR AND INCLUDED SOME IFR CIGS TOWARD MORNING WITH CLOUDS BREAKING AROUND MID DAY. WILL MONITOR TRENDS TO SEE HOW THIS GOES. WINDS WILL REMAIN FROM A SOUTHERLY DIRECTION. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...FAY LONG TERM...PFANNKUCH AVIATION...FAY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1215 AM CDT SUN JUL 20 2014 .SYNOPSIS... ISSUED AT 300 PM CDT SAT JUL 19 2014 A STRONG UPPER LEVEL RIDGE OF SUBTROPICAL HIGH PRESSURE CENTERED OVER THE SOUTHWEST WILL MODULATE THE WEATHER FOR THE NEXT 7 DAYS AS IT MOVES EAST AND WEST ACROSS THE SOUTH. RAIN CHANCES ARE ISOLATED AT BEST AND COLD FRONTS WILL BE WEAK PRESENTING MOSTLY ABOVE NORMAL TEMPERATURES FOR THE NEXT 7 DAYS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 300 PM CDT SAT JUL 19 2014 FORECAST CONCERNS THROUGH SUNDAY INCLUDE THUNDERSTORM CHANCES TONIGHT AS WELL AS HIGH TEMPERATURES AND HEAT INDICES ON SUNDAY AFTERNOON. AT 19Z WATER VAPOR IMAGERY SHOWED TROUGHING OVER THE EASTERN CONUS WITH A BROAD RIDGE CENTERED OVER THE DESERT SOUTHWEST. SEVERAL SHORTWAVES WERE EMBEDDED IN THE FLOW MOVING OVER THE RIDGE FROM THE PACIFIC NORTHWEST INTO THE CENTRAL PLAINS. AT THE SURFACE...HIGH PRESSURE REMAINED OVER MUCH OF THE EASTERN PART OF THE COUNTRY AND WITH A TROUGH OF LOW PRESSURE FROM THE IDAHO INTO THE SOUTHERN PLAINS...SOUTHERLY FLOW PERSISTS INTO THE CENTRAL PLAINS. ASIDE FROM CLOUDS ASSOCIATED WITH THE NORTH CENTRAL NEBRASKA CONVECTION...SKIES OVER THE LOCAL AREA WERE MOSTLY SUNNY AS LAPS SOUNDINGS SHOWED THE ENTIRE AREA STILL CAPPED. FOR TONIGHT...IF CONVECTION DEVELOPS OVER THE PANHANDLE AND WESTERN SANDHILLS YET THIS AFTERNOON COULD GET SOME ACTIVITY TO SLIDE EASTWARD THIS EVENING AS THERE WILL BE SUFFICIENT INSTABILITY ACROSS THE FORECAST AREA FOR STORMS TO WORK WITH. THE CONCERN WITH HOW LONG ANY ACTIVITY WILL CONTINUE IS THAT THERE LOOKS TO BE A LACK IN FORCING AS THERE ISN/T A STRONG SHORTWAVE MOVING THROUGH AND THE LOW LEVEL JET WILL STRENGTHEN THIS EVENING BUT PRIMARY FOCUS WILL BE TO THE NORTH OVER SOUTH DAKOTA SO NOT EXPECTED MUCH FOR ENHANCED LIFT ASSOCIATED WITH THAT FORCING. ALSO...MOISTURE IS LACKING ACROSS THE AREA SO THINKING THAT ANY ACTIVITY WILL BE MORE ISOLATED IN NATURE. THE NAM AND THE RAP BOTH INDICATE A VERY WEAK SHORTWAVE TROUGH MOVING ACROSS NEBRASKA TONIGHT...BUT NEITHER PRODUCE ANY CONVECTION. THE GFS ON THE OTHER HAND AFTER BEING DRY THROUGH THE EVENING...SHOWS SOME CONVECTION OVER EASTERN NEBRASKA AFTER 06Z. BIAS WOULD BE TO KEEP THE FORECAST DRY FOR LATE EVENING AND BEYOND...HOWEVER MODELS DID POORLY WITH THE CURRENT CONVECTION OVER NORTHERN NEBRASKA. SO...WITH THE INSTABILITY IN PLACE AND VERY STEEP LAPSE RATES IN THE MID LEVELS WILL PUT AN ISOLATED MENTION IN THE FORECAST FOR LATE TONIGHT. FOR SUNDAY...THE UPPER LEVEL RIDGE BUILDS EAST BRINGING WARMER AIR ALOFT INTO THE CENTRAL PLAINS. AT 700MB...TEMPERATURES ACROSS THE FORECAST AREA INCREASE TO 15-17C BY 00Z MONDAY WHEREAS RAOB DATA FROM THIS MORNING /19.12Z/ SHOWED TEMPERATURES AT 700MB AT 10-12C. WITH DRY AIR ACROSS THE AREA SHOULD HAVE PLENTIFUL SUNSHINE SO EXPECTING TEMPERATURES TO WARM EFFICIENTLY. STATISTICAL GUIDANCE GIVES HIGHS FOR PORTIONS OF THE AREA AT OR ABOVE 100 DEGREES ACROSS MUCH OF THE FORECAST AREA. THE CONCERN WITH REACHING THESE LEVELS OF HEAT WILL BE THE MOISTURE IN THE LOW LEVELS. MODELS ARE CONTINUING TO KEEP DEWPOINTS IN THE 50S AND 60S MOST AREAS WHICH WON/T HELP THE TEMPERATURES TO REACH THOSE LEVELS. BUT...SOUNDINGS ARE INDICATING FULL MIXING WOULD BRING HIGHS TO 105 IN PLACES. THINK THIS IS TOO HIGH AND WHEN LOOKING AT SREF PLUMES THE MAJORITY OF THE MODEL SOLUTIONS ARE BELOW THE CENTURY MARK. KEPT THE FORECAST VERY SIMILAR TO THE PREVIOUS SO KEPT HIGHS FOR MOST AREAS FROM THE MID 90S TO AROUND 100 DEGREES. HEAT INDEX VALUES WILL BE A CONCERN AS WELL...MAINLY IN AREAS EAST OF A KIML TO KLBF TO KANW LINE. THESE ARE THE LOCATIONS THAT WILL SEE THE COMBINATION OF THE HIGHER TEMPERATURES AND HIGHER DEWPOINTS. TO THE WEST OF THIS LINE DRIER AIR IS EXPECTED TO MIX DOWN WHICH COULD ACTUALLY BRING RELATIVE HUMIDITY DOWN NEAR 15 PERCENT. HELD OFF ON ANY MENTION OF HEAT ADVISORY DUE TO VALUES BEING RIGHT AT THE THRESHOLD OF 100 DEGREES ALONG WITH SOME UNCERTAINTY IN REACHING THESE VALUES. AS MENTIONED SOME PLACES MAY SEE RELATIVE HUMIDITY DROP NEAR 15 PERCENT OVER PORTIONS OF THE PANHANDLE AND WESTERN SANDHILLS. DESPITE THE HOT AND DRY CONDITIONS...DON/T ANTICIPATE FIRE DANGER GETTING TO A CRITICAL LEVEL AS WINDS ARE NOT EXPECTED TO BE STRONG IN THE AFTERNOON. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 300 PM CDT SAT JUL 19 2014 SUNDAY NIGHT THROUGH TUESDAY...THE DRYLINE SURGE SUNDAY CONTINUES MONDAY. A SLIGHT RETREAT IS EXPECTED SUNDAY NIGHT BUT LOW PRESSURE DEEPENING ACROSS SD MONDAY SHOULD MOVE IT BACK EAST OF HIGHWAY 83. AT THE SAME TIME...A SUBTROPICAL DISTURBANCE ACROSS SRN CA THIS AFTN WILL LIFT NORTHEAST THROUGH THE FCST AREA MONDAY SETTING UP THE POTENTIAL FOR ISOLATED HIGH BASED TSTMS IN THE AFTN OR AT NIGHT AFFECTING AREAS EAST OF HIGHWAY 83. MOISTURE WITH THE STORMS WILL BE LIMITED AND OPERATE ABOVE 700 MB. HEAT AND MOISTURE AHEAD OF THE DRYLINE MAY PRODUCE HEAT ADVISORY CONDITIONS MONDAY ALONG AND EAST OF HIGHWAY 183 WITH HIGHS 95 TO 100 AND HEAT INDICES 100 TO 105. THE UPPER LEVEL DISTURBANCE DEEPENS ACROSS THE MIDWEST MONDAY NIGHT AND SENDS A WEAK COLD FRONT THROUGH THE FCST AREA TUESDAY FOR HIGHS 90 TO 95. THE FRONT UNDERCUTS THE UPPER LEVEL RIDGE AND THE ATMOSPHERE REMAINS CAPPED AND DRY TUESDAY. TUESDAY NIGHT THROUGH SATURDAY...CANADIAN HIGH PRESSURE BACKS IN AND THE SUBTROPICAL HIGH RETREATS WEST. THIS SHOULD SET UP A STATIONARY FRONT ACROSS WRN NEB WITH LOW PRESSURE ACROSS THE NRN HIGH PLAINS. A DEEP UPPER LEVEL LOW WILL MOVE ASHORE ACROSS THE PACIFIC NORTHWEST AND THIS ANCHORS THE LOW ACROSS THE HIGH PLAINS AND DRAWS COOLER AIR WEST THROUGH THE FCST AREA. IN TIME A PACIFIC COLD FRONT WILL SWEEP THE FCST AREA ALONG ABOUT FRIDAY AS THE UPPER LOW MOVES INTO CNTL CANADA. THERE ARE SOME ISOLATED POPS IN THE FORECAST BUT THE SIGNAL THE MODELS GIVE IS DRY OWING TO WARM AIR ALOFT EFFECTIVELY CAPPING CONVECTION ACROSS THE FCST AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1214 AM CDT SUN JUL 20 2014 MID AND HIGH CLOUDS ACROSS WESTERN NEBRASKA TONIGHT WITH LIGHT SOUTHERLY WINDS. THROUGH THE EARLY MORNING HOURS SUNDAY STRATUS WILL REFORM THROUGH THE NORTH PLATTE AREA AND THEN STREAM NORTH THOUGH THE NEBRASKA SANDHILLS TOWARDS VALENTINE AS IT HAS DONE THE LAST 4 MORNINGS. NOT REAL CONFIDENT WITH STRATUS FORMATION EARLY THIS MORNING. SKIES WILL CLEAR THROUGH LATE MORNING. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CDC SHORT TERM...BROOKS LONG TERM...CDC AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1155 PM CDT SAT JUL 19 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 400 PM CDT SAT JUL 19 2014 THE REGION REMAINS UNDER NORTHWESTERLY FLOW IN THE UPPER LEVELS...THANKS AN AREA OF LOW PRESSURE SLIDING EAST ACROSS THE GREAT LAKES/MIDWEST REGION...AND RIDGING EXTENDING INTO THE ROCKIES. AN SMALL AREA OF PRECIPITATION ASSOCIATED WITH A WEAK WAVE MOVING OUT OF WRN SD CONTINUES TO SLIDE SE...THOUGH IT HAS BEEN DIMINISHING WITH TIME. COULD CLIP THE NRN PORTIONS OF THE CWA OVER THE NEXT FEW HOURS...SO HAVE A SMALL SLIGHT CHANCE POP GOING FOR LATE THIS AFTERNOON. AT THE SURFACE...CONTINUING TO SEE SRLY WINDS ACROSS THE AREA...SET UP BETWEEN LOW PRESSURE EXTENDING ALONG THE HIGH PLAINS...WITH A LARGE AREA OF HIGH PRESSURE STRETCHING FROM TX INTO THE GREAT LAKES REGION. LOW LEVEL STRATUS HAS BEEN STUBBORN OVER THE SWRN PORTIONS OF THE CWA...KEEPING TEMPS AT 3 PM IN THE LOWER/MID 70S...WITH TEMPS CLOSER TO 80 IN AREAS WITH MORE SUN. ANOTHER BOUT OF THUNDERSTORM ACTIVITY IS EXPECTED TO DEVELOP ALONG THE HIGH PLAINS LATE THIS AFTERNOON...AND MAIN QUESTION LATE THIS EVENING/OVERNIGHT WILL BE WHETHER ANY OF THAT ACTIVITY CAN DRIFT FAR ENOUGH EAST TO AFFECT THE CWA. MOST MODELS SAY ITS NOT LIKELY...BUT THE 12Z 4KM IS SHOWING THAT POTENTIAL. INHERITED A FORECAST WITH SLIGHT CHANCE POPS ACROSS NEB...AND NOT CONFIDENT ENOUGH THAT NOTHING WILL HAPPEN TO TAKE THOSE POPS OUT. LOOKING AHEAD TO SUNDAY...THE MAIN STORY LIES WITH THE INCREASE IN TEMPERATURES. MODELS IN GOOD AGREEMENT SHOWING THE MAIN UPPER LEVEL RIDGE AXIS BUILDING FURTHER EAST...BECOMING MORE ORIENTATED N/S THROUGH THE ROCKIES. EXPECTING DRY CONDITIONS WITH ANY DISTURBANCES REMAINING OUTSIDE OF THE CWA. MODELS SHOWING 850MB TEMPS INCREASING FROM THE MID TEEN TO LOWER 20C RANGE THIS MORNING TO THE MID 20/NEAR 30C RANGE BY THE END OF THE DAY TOMORROW. NO SIGNIFICANT CHANGES WERE MADE TO HIGHS FOR TOMORROW...WHICH WILL BE INFLUENCED BY WHAT DEWPOINTS END UP BEING. AT THIS POINT EXPECTING THE NERN CORNER OF THE CWA TO HAVE DEWPOINTS CLIMB TO NEAR 70/LOWER 70S...SO EXPECT THAT TEMPS WILL HAVE A HARD TIME REACHING MUCH ABOVE THE MID 90S. FURTHER SW...MODELS IN OK AGREEMENT SHOWING DEWPOINTS CLOSER TO THE LOWER 60S...AND EXPECTING TEMPS TO CLIMB TO NEAR 100. BOTH COMBINATIONS RESULT IN PEAK AFTERNOON HEAT INDEX VALUES OVER 100 DEGREES. HELD OFF ON ANY HEADLINES AT THIS POINT...WAS NOT GETTING WIDESPREAD VALUES OF 105+ DEGREES...BUT WILL BE SOMETHING FOR THE MIDNIGHT CREW TO TAKE ANOTHER LOOK AT. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 400 PM CDT SAT JUL 19 2014 AN UPPER LEVEL RIDGE ACROSS THE DESERT SOUTHWEST WILL EXTEND NORTHEASTWARD INTO THE PLAINS FOR MUCH OF THE UPCOMING WORKWEEK...WITH THIS RIDGE EVENTUALLY FLATTENING OUT LATE IN THE WEEK AS AN AREA OF LOW PRESSURE TRACKS ALONG THE US/CANADIAN BORDER. WHILE THERE ARE SEVERAL SMALL CHANCES FOR THUNDERSTORMS IN THE EXTENDED PERIODS OF THE FORECAST...CONFIDENCE IS FAIRLY LOW...AND DO NOT EXPECT WIDESPREAD THUNDERSTORM COVERAGE ANY PARTICULAR DAY FOR THE TIME BEING. STARTING MONDAY...EXPECT THE UPPER LEVEL RIDGE TO BE EXTENDED INTO SOUTH CENTRAL NEBRASKA...AND REMAIN FIRMLY ENTRENCHED THROUGH AT LEAST TUESDAY AFTERNOON. AS A RESULT...EXPECT A PAIR OF VERY HOT DAYS ACROSS THE REGION...AND CORRESPONDINGLY INCREASED AFTERNOON TEMPS A COUPLE OF DEGREES TO BETTER MATCH WITH LATEST GUIDANCE. OTHERWISE...COULD SEE A FEW THUNDERSTORMS FIRE UP DURING THE LATE AFTERNOON AND EVENING HOURS MONDAY...AS A WEAK UPPER LEVEL DISTURBANCE TRANSITIONS OVER THE TOP OF THE RIDGE AND THE AXIS OF A WEAK LLJ IS FOCUSED ACROSS THE LOCAL AREA OVERNIGHT. WITH GOOD DIURNAL HEATING...EXPECT THE CAP TO BE MOSTLY ERODED BY LATE AFTERNOON...AND WHILE WIDESPREAD ACTIVITY IS NOT EXPECTED...WAS ABLE TO JUSTIFY SLIGHT CHANCES FOR THUNDERSTORMS IN THE FORECAST DESPITE THE LACK OF SIGNIFICANT FORCING. FOR LATE TUESDAY AFTERNOON/NIGHT...EXPECT A SLIGHT MODIFICATION IN THE LOCAL AIRMASS AS A COOL FRONT TRACKS ACROSS THE LOCAL AREA ...WHICH SHOULD ALSO PROVIDE MINIMAL CHANCES FOR THUNDERSTORMS. AS A RESULT...EXPECT A MODEST COOLING FOR MID WEEK...AS 850 MB TEMPS ARE EXPECTED TO FALL ABOUT 5C IN WAKE OF THE FRONTAL PASSAGE...LIKELY DROPPING TEMPERATURES FOR WEDNESDAY AND THURSDAY CLOSER TO CLIMATOLOGY FOR LATE JULY. WHILE CONFIDENCE AGAIN IS LOW...THE GFS IS INDICATING A MCS MAY DEVELOP FROM AN UPPER LEVEL DISTURBANCE ORIGINATING IN THE SOUTHWEST AND TRACKING ACROSS THE LOCAL AREA WEDNESDAY NIGHT...AND ALTHOUGH THIS DISTURBANCE TRACKS MUCH FURTHER NORTHWARD IN THE EC...DECIDED TO INTRODUCE SMALL CHANCES FOR THUNDERSTORMS INTO THE FORECAST FOR WEDNESDAY NIGHT INTO THURSDAY. OTHERWISE...TEMPERATURES WILL SLOWLY CREEP UP LATE WEEK...WITH YET ANOTHER COOL FRONT TRANSITIONING ACROSS THE LOCAL AREA FRIDAY NIGHT AS AN UPPER LEVEL LOW TRACKS NEAR THE CANADIAN BORDER. THIS FRONT MAY PROVIDE A FOCUS FOR SMALL THUNDERSTORM CHANCES FRIDAY NIGHT...BUT ONCE AGAIN...MORE WIDESPREAD COVERAGE IS NOT ANTICIPATED AT THIS TIME...WITH THE MAIN EFFECT BEING POTENTIALLY SLIGHTLY COOLER WEATHER NEXT WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1151 PM CDT SAT JUL 19 2014 MAIN CONCERN FOR THE TAF PERIOD IS WHETHER OR NOT STRATUS WILL REDEVELOP TOWARD DAYBREAK. MODELS HAVE NOT HAVE THE BEST HANDLE ON THE STRATUS THE PAST COUPLE OF NIGHTS/MORNINGS ESPECIALLY WITH HOW LONG THE LOW CLOUDS WILL PERSIST. THE HRRR AGAIN DEVELOPS STRATUS TOWARDS MORNING...WITH THE LOW CLOUDS DEVELOPING ACROSS OUR WESTERN CWA WHEREAS THE NAM LLVL RH PROGS INDICATE THE BETTER POTENTIAL TO THE EAST. HAVE FOLLOWED CLOSER TO THE HRRR AND INCLUDED SOME IFR CIGS TOWARD MORNING WITH CLOUDS BREAKING AROUND MID DAY. WILL MONITOR TRENDS TO SEE HOW THIS GOES. WINDS WILL REMAIN FROM A SOUTHERLY DIRECTION. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...ADO LONG TERM...ROSSI AVIATION...FAY
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
311 PM MDT SUN JUL 20 2014 .SYNOPSIS... SLOW MOVING SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL WILL CONTINUE THROUGH TUESDAY FOR PORTIONS OF CENTRAL AND EASTERN NEW MEXICO. THE COVERAGE OF THIS ACTIVITY WILL BE MORE ISOLATED IN NATURE THAN RECENT WEEKS. A STRONG AREA OF HIGH PRESSURE WILL THEN SHIFT OVER THE STATE WEDNESDAY AND BRING THE HOTTEST TEMPERATURES IN QUITE A WHILE FOR CENTRAL AND WESTERN NEW MEXICO. MANY LOWER ELEVATION AREAS WILL TOP OUT IN THE MID 90S TO LOW 100S. THE HIGH WILL THEN SHIFT WEST AND ALLOW SEVERAL MOIST BACK DOOR FRONTS TO SHIFT WESTWARD INTO THE STATE. THIS WILL TAPER OFF THE HEAT AND INTRODUCE ANOTHER ROUND OF MORE SCATTERED THUNDERSTORMS FRIDAY INTO THE WEEKEND. && .DISCUSSION... FORECAST CONFIDENCE FOR THIS EVENING IS VERY LOW BUT WITH MODERATE POTENTIAL IMPACT. SHORT-TERM MODEL GUIDANCE IS ALL OVER THE PLACE WITH RESPECT TO PLACEMENT OF CONVECTIVE FEATURES THIS EVENING. THE 20Z SURFACE DEWPOINT VALUES ARE CRATERING OVER MUCH OF THE REGION DESPITE ABUNDANT MID AND UPPER LEVEL MOISTURE. THE BEST MOISTURE IS POOLING AROUND THE MIDDLE RIO GRANDE VALLEY AND OVER THE SE PLAINS. THE LATEST HRRR AND 12Z GFS ARE PICKING UP ON A CONVECTIVE COMPLEX MOVING FROM THE DIVIDE TO NEAR THE ABQ METRO THIS EVENING. THE 06Z WRF AND NAM GUIDANCE SHOWED THIS EARLIER BUT BACKED OFF ON IT FOR THE 12Z RUN. QPF VALUES COULD BE HIGH BENEATH A SLOW MOVING SOUTH TO NORTH COMPLEX BUT PLACEMENT AND DURATION IS VERY QUESTIONABLE. PLACED CHANCE POPS OVER A LARGE AREA OF CENTRAL NM AS A RESULT. THE OTHER WRINKLE IS THE HRRR SHOWS A LARGE AREA OF PRECIP SHIFTING NORTH AFTER 06Z UP THE LOWER RIO GRANDE VALLEY. WOULD NOT BE SURPRISED TO SEE THIS OCCUR AS THE LATEST IR SHOWS SOME VIGOROUS CONVECTION ERUPTING OVER NORTH CENTRAL MEXICO. THE GFS ENSEMBLE AND SREF SHOW WITH VERY GOOD AGREEMENT THE CURRENT 594DM H5 HIGH CENTERED OVER SOUTHEAST NM SHIFTING NORTH MONDAY AND TUESDAY AND BUILDING TO 599DM OVER SOUTHERN COLORADO. THIS INTRODUCES ANOTHER TOSS UP AS HEIGHTS RISE WELL ABOVE NORMAL BUT AN AXIS OF MID LEVEL MOISTURE ROTATES WEST FROM WEST/CENTRAL TX. SEVERAL DAYS AGO MODELS WERE CONSERVATIVE WITH CONVECTIVE DEVELOPMENT BUT TRENDS HAVE BEEN FOR MORE COVERAGE...PARTICULARLY TUESDAY. MADE ONLY SUBTLE POP CHANGES TO INCREASE VALUES OVER THE PLAINS. OTHERWISE...EXPECT AT LEAST HOT TEMPS. BEYOND WEDNESDAY THE UPPER HIGH WILL TREND TOWARD THE WEST WHILE YET ANOTHER VERY STRONG SUMMER UPPER LOW SLIDES INTO THE GREAT LAKES. THE TRANSITION PERIOD FOR THURSDAY/FRIDAY IS ALSO LOW CONFIDENCE DEPENDING ON HOW THE HIGH WARPS AND DRIFTS WESTWARD. A STRONG BACK DOOR FRONT IS THEN DEPICTED SATURDAY THROUGH EARLY NEXT WEEK AS A FOCUS MECHANISM FOR MORE CONVECTION OVER NM. THIS IS MOST CERTAINLY NOT ANYWHERE NEAR THE TYPE OF PATTERN THAT ONE WOULD EXPECT TO SEE OVER THE CONUS DURING LATE JULY. GUYER && .FIRE WEATHER... WHILE TODAYS SHOWER AND STORM CROP HAS BEEN A SLOW STARTER...IT MAY END UP TO BE NEARLY AS GOOD OR BETTER COVERAGE IN CENTRAL AND SOUTHERN PORTIONS OF THE FORECAST AREA BY LATE AFTN OR EVE. THE BULK OF THE BURN SCAR AREAS WILL CONTINUE TO HAVE SOME RISK OF HEAVY RUNOFF OR WORSE THROUGH THE EVE. THE AMOUNT AND LOCATION OF THE MAXIMUM SHOWER AND THUNDERSTORM ACTIVITY WILL VARY A FAIR DEGREE FROM DAY TO DAY ACROSS THE NEXT 5 TO 7 DAYS...PROBABLY SHIFTING A LITTLE WAYS TO THE EAST AND SOUTH MON AND THEN BACK TO THE WEST AND NORTH TUE AND WED. IT BECOMES A LITTLE LESS CERTAIN THEREAFTER...AS TO LOCATION AND DEGREE OF COVERAGE...BUT LONGER RANGE FORECAST MODEL DATA SEEMS TO AGREE PRETTY WELL THAT A MODERATE TO STRONG BACK DOOR COLD FRONT FOR THIS TIME OF YEAR WILL PUSH INTO AND ACROSS AT LEAST EAST AND CENTRAL NM AND PERHAPS EVEN FARTHER WEST SAT NIGHT INTO SUN. THIS SHOULD GENERATE A MODERATE TO ROBUST INCREASE IN SHOWERS AND STORMS NEAR AND BEHIND ITS PASSAGE BETWEEN LATE SAT AND MON. UNTIL THEN HOWEVER...ABOVE NORMAL TEMPERATURES AND AT LEAST SLIGHTLY BELOW NORMAL THUNDERSTORM ACTIVITY FOR MID TO LATE JULY CAN BE EXPECTED DUE TO A DOMINANT UPPER HIGH OVER THE REGION. NO CRITICAL WIND SPEEDS ARE EXPECTED OVER THE NEXT 5 TO 7 DAYS AT LEAST...COMMON FOR THIS TIME OF YEAR...BUT MINIMUM RHS HAVE REACHED MARGINALLY CRITICAL LEVELS ACROSS A FEW SITES ACROSS NORTH NM AND EVEN THE LOWER RIO GRANDE VALLEY. THIS MAY EXPAND SOMEWHAT BETWEEN MON AND WED...BUT SUBSIDE SOME AGAIN BY LATE WEEK OR THE WEEKEND HAINES INDICES ARE FORECAST TO TREND UP SOME MON AND PERHAPS TUE...THEN DROP SOME WED AND THU BEFORE TRENDING BACK UP NEAR END OF WEEK. OVERNIGHT RH RECOVERIES WILL VARY FROM FAIR TO VERY GOOD...DEPENDING IN LARGE PART ON WHERE THE MORE SIGNIFICANT RAINFALL HAS FALLEN ON A PARTICULAR DAY. 43 && .AVIATION... 18Z TAF CYCLE VFR CONDITIONS AND LIGHT TO LOCALLY MODERATE WINDS LIKELY TO PERSIST THROUGH 18Z MONDAY OUTSIDE OF ISOLATED TO SCATTERED SHRA AND TSRA WHICH SHOULD OCCUR MAINLY BETWEEN 20Z TODAY AND 05Z MONDAY. THE STRONGER STORMS WILL BE CAPABLE OF GENERATING BRIEF MVFR CIGS AND VSBYS AS WELL AS MT OBSCURATIONS. TAF SITES MOST LIKELY TO EXPERIENCE THE CONVECTION ARE LVS...TCC AND SAF AND TO A LESSER DEGREE GUP AND ROW. 43 && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 63 96 58 99 / 5 5 0 5 DULCE........................... 51 90 49 93 / 20 10 10 20 CUBA............................ 57 89 54 91 / 40 10 10 20 GALLUP.......................... 59 92 54 93 / 10 5 5 20 EL MORRO........................ 53 82 53 86 / 20 10 10 30 GRANTS.......................... 53 88 52 92 / 30 10 10 10 QUEMADO......................... 56 84 56 87 / 20 10 10 20 GLENWOOD........................ 58 93 58 95 / 10 5 10 20 CHAMA........................... 47 83 47 86 / 20 30 10 30 LOS ALAMOS...................... 61 85 60 87 / 40 20 10 20 PECOS........................... 58 84 57 84 / 30 30 20 30 CERRO/QUESTA.................... 54 81 52 82 / 30 30 20 30 RED RIVER....................... 48 74 49 75 / 30 50 20 40 ANGEL FIRE...................... 44 78 44 80 / 30 60 20 30 TAOS............................ 53 85 52 88 / 30 20 20 20 MORA............................ 54 83 53 83 / 30 60 20 30 ESPANOLA........................ 60 91 60 94 / 30 20 10 10 SANTA FE........................ 61 87 59 88 / 40 20 20 20 SANTA FE AIRPORT................ 61 93 59 92 / 30 20 20 20 ALBUQUERQUE FOOTHILLS........... 66 93 65 94 / 30 10 10 10 ALBUQUERQUE HEIGHTS............. 68 96 69 96 / 30 10 10 10 ALBUQUERQUE VALLEY.............. 65 97 66 97 / 30 5 10 5 ALBUQUERQUE WEST MESA........... 67 97 68 98 / 30 10 10 5 LOS LUNAS....................... 63 96 64 97 / 30 5 10 5 RIO RANCHO...................... 67 98 68 98 / 30 10 10 10 SOCORRO......................... 70 99 70 99 / 40 5 10 10 SANDIA PARK/CEDAR CREST......... 62 91 61 91 / 30 20 10 20 TIJERAS......................... 62 93 60 93 / 30 10 10 20 MORIARTY/ESTANCIA............... 59 88 57 88 / 30 30 20 20 CLINES CORNERS.................. 60 88 60 87 / 30 50 20 30 GRAN QUIVIRA.................... 63 90 62 90 / 30 30 20 20 CARRIZOZO....................... 67 91 67 90 / 20 10 20 20 RUIDOSO......................... 59 86 59 84 / 20 40 20 30 CAPULIN......................... 62 85 61 85 / 20 40 20 20 RATON........................... 61 89 59 89 / 30 30 20 20 SPRINGER........................ 61 91 60 91 / 30 30 20 20 LAS VEGAS....................... 59 86 57 85 / 30 60 20 30 CLAYTON......................... 67 94 67 95 / 20 20 30 20 ROY............................. 65 89 63 89 / 20 30 30 20 CONCHAS......................... 70 97 69 95 / 20 20 30 20 SANTA ROSA...................... 68 94 69 93 / 20 20 30 20 TUCUMCARI....................... 71 97 70 96 / 20 20 30 20 CLOVIS.......................... 67 92 67 92 / 20 20 20 10 PORTALES........................ 69 96 69 96 / 20 20 20 10 FORT SUMNER..................... 70 96 69 94 / 20 20 20 20 ROSWELL......................... 70 98 70 96 / 20 20 20 10 PICACHO......................... 66 90 66 89 / 20 20 20 20 ELK............................. 64 84 63 84 / 20 20 30 40 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1150 PM MDT SAT JUL 19 2014 .AVIATION... 06Z TAF CYCLE THUNDERSTORMS HAVE FINALLY DISSIPATED MOST AREAS WITH A CLUSTER IN SOUTHERN CHAVES COUNTY SOUTH OF KROW MOVING TO THE SOUTH. SPOTTY SHOWERS WILL PERSIST MAINLY ACROSS PORTIONS OF THE WEST AND EASTERN PLAINS BUT VFR CONDITIONS ARE EXPECTED. ANOTHER ROUND OF LOW CLOUDS IS POSSIBLE BUT BEST CHANCES ARE LIMITED TO THE TEXAS BORDER INCLUDING KCVS THUS LOW CIGS NOT INCLUDED AT KTCC AND KROW AS CONFIDENCE IS LOW. FOR MONDAY...THUNDERSTORMS TO DEVELOP BY LATE MORNING OVER THE HIGH TERRAIN THEN MOVE TO THE EAST WITH SHOWERS AND THUNDERSTORMS POSSIBLE NEARLY ALL AREAS WITH FEWEST STORMS NORTHWEST AND BEST CHANCES CENTRAL HIGH TERRAIN AND ADJACENT HIGHLANDS. 05 && .PREV DISCUSSION...315 PM MDT SAT JUL 19 2014... .SYNOPSIS... SCATTERED SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL WILL CONTINUE THROUGH MONDAY FOR MUCH OF CENTRAL AND EASTERN NEW MEXICO. THE CENTER OF A STRONG AREA OF HIGH PRESSURE WILL SHIFT OVER THE STATE TUESDAY AND WEDNESDAY AND BRING THE HOTTEST TEMPERATURES IN QUITE A WHILE. MANY LOWER ELEVATION AREAS WILL TOP OUT IN THE MID 90S TO LOWER 100S. THE HEAT WILL TAPER OFF BY LATE NEXT WEEK AS A SHOT OF SLIGHTLY COOLER TEMPERATURES AND SCATTERED STORMS RETURN TO THE AREA. && .DISCUSSION... NOT MUCH CHANGE INTRODUCED BY GUIDANCE THIS MORNING. CURRENT RADAR AND SATELLITE ANALYSIS VERIFY THE FOCUS OF THE THETA-E RIDGE AXIS OVER CENTRAL NEW MEXICO. STEERING FLOW WILL GUIDE ACTIVITY INTO THE EASTERN PLAINS LATE THIS AFTERNOON AND EVENING. A SEVERE STORM TO THE SOUTH OF LAS VEGAS WILL SERVE AS A SIGN OF THE AMOUNT OF INSTABILITY INDICATED BY 20Z LAPS DATA. POTENTIAL FOR QUARTER HAIL AND STRONG WINDS IS THERE WITH THE STRONGER CONVECTION AS IT MOVES EAST TOWARD THE EAST CENTRAL PLAINS. THE LATEST HRRR DOES SHOW BOUNDARY INTERACTIONS WITHIN THE RIO GRANDE VALLEY SO SOME CHANCE FOR SHOWERS/STORMS IS ON TAP FOR THE ABQ METRO. THE OVERALL PATTERN WILL NOT CHANGE MUCH INTO MONDAY. THE LATEST WATER VAPOR LOOP SHOWS A SHEARED UPPER WAVE OVER THE BAJA WITH A DEEP TAP OF SUB-TROPICAL MOISTURE MOVING NORTH ACROSS WESTERN MEXICO TOWARD SW NEW MEXICO. GFS/NAM THETA-E RIDGE AXIS FOCUSES THE BEST INSTABILITY OVER CENTRAL AND EASTERN NM INTO MONDAY. THE H5 HIGH WILL BUILD SLIGHTLY MORE TO 596DM BY MONDAY SO COVERAGE WILL APPEAR MORE SUPPRESSED COMPARED TO THE WEEKEND. VERY HOT TEMPS ARE THEN IN STORE FOR TUESDAY AND WEDNESDAY AS THE H5 HIGH BUILDS TO NEAR 600DM AND 700MB TEMPS APPROACH +21C. MANY AREAS IN THE LOW ELEVATIONS WILL AVERAGE MID 90S TO LOW 100S...ESPECIALLY FROM ABQ SOUTH INTO THE EASTERN PLAINS. COVERAGE OF STORMS WILL BE LIMITED TO HIGH TERRAIN AREAS. DESPITE FEWER STORMS STEERING FLOW WILL BE VERY WEAK SO LOCALLY HEAVY RAINFALL IS LIKELY WHERE EVER A STORM FIRES UP. BEYOND WEDNESDAY MODELS ARE CHANGING THEIR TUNE AGAIN ON WHERE THE UPPER HIGH WILL MIGRATE TO ACROSS THE SOUTHWEST. THE LATEST SHOWS THE HIGH STAYING MORE FIRMLY IN PLACE OVER NM WITH ONLY SLIGHT WOBBLES TO THE WEST. THIS STILL ALLOWS SOME BACK DOOR COLD FRONTS TO SLIDE THROUGH THE PLAINS BUT THE COVERAGE OF PRECIP ACTIVITY COULD REMAIN LIMITED TO THE NORTHEAST. GUYER && .FIRE WEATHER... A FORMER EASTERLY WAVE TRACKING NORTHWARD ACROSS S CA THIS AFTERNOON WILL CIRCUMAMBULATE AN UPPER HIGH OVER NM TONIGHT AND SUNDAY BEFORE EJECTING EASTWARD INTO THE GREAT PLAINS FROM THE CENTRAL ROCKIES EARLY MONDAY. THE MOIST NORTHERLY RETURN FLOW ON THE EAST SIDE OF THIS WAVE WILL CONTINUE TO SEEP UNDER THE 500 MB HIGH OVER NM WITH ANOTHER DAY OF GOOD WETTING STORM COVERAGE ON SUNDAY. LOCALLY HEAVY RAIN WILL BE POSSIBLE THIS EVENING AND AGAIN SUNDAY WITH THE POTENTIAL FOR BURN SCAR FLASH FLOODING. IN THE WAKE OF THE WAVE ON MONDAY THE 500 MB HIGH WILL STRENGTHEN OVER THE STATE...AND DRIER LOW LEVEL AIR WILL MOVE IN FROM THE WEST AND NORTHWEST...CAUSING A DOWNTICK IN THUNDERSTORM COVERAGE OVER CENTRAL AND NW AREAS. THUNDERSTORM COVERAGE SHOULD INCREASE AGAIN BEGINNING TUESDAY AS THE CENTER OF THE 500 MB HIGH TRAVELS NORTHWARD OVER S CO ALLOWING BETTER MOISTURE TO MOVE INTO EASTERN AND SOUTHERN AREAS FROM THE S AND SE. AN UPPER LOW PASSING SLOWLY EASTWARD ALONG THE NW US BORDER WITH CANADA IS FORECAST TO DRAW THIS MOISTURE OVER CENTRAL...WESTERN AND NORTHERN NM WEDNESDAY THROUGH THE END OF THE WORK WEEK IN THE FORM OF A MODEST MONSOON MOISTURE PLUME WITH DAILY ROUNDS OF SHOWERS AND THUNDERSTORMS IN THE CLIMATOLOGICALLY FAVORED AREAS FOR THIS TIME OF YEAR. TEMPERATURE-WISE...HIGHS SHOULD WARM SLIGHTLY IN MOST LOCATIONS DAILY THROUGH MONDAY AS THE UPPER HIGH BUILDS OVERHEAD. READINGS SHOULD TREND DOWNWARD AS BETTER MOISTURE ARRIVES BEGINNING TUESDAY IN THE EAST...BUT NOT UNTIL WEDNESDAY ELSEWHERE. HAINES INDICES OF 5 SHOULD BE COMMON EACH DAY ACROSS NORTHERN...WESTERN AND CENTRAL AREAS...EXCEPT FOR VALUES OF 6 FROM CENTRAL TO NORTHWEST AREAS MONDAY AND TUESDAY. 44 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
330 PM EDT SUN JUL 20 2014 .SYNOPSIS... HIGH PRESSURE WILL BRING MOSTLY DRY WEATHER TO THE AREA THROUGH TUESDAY WITH NOTHING MORE THAN A FEW ISOLATED AFTERNOON SHOWERS OR THUNDERSTORMS. TEMPERATURES WILL GRADUALLY WARM... WITH READINGS WELL INTO THE 80S TO NEAR 90 BY TUESDAY AFTERNOON. A COLD FRONT WILL BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS ON WEDNESDAY FOLLOWED BY DRYER AND COOLER WEATHER THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH MONDAY/... ISLD SHRA WERE RAPIDLY HEADING INTO NRN NY AS SHRT WAVE MOVES INTO NRN NEW ENGLAND. WATER VAPOR IMAGERY AND LATEST RAP FIELDS SHOW ANOTHER SHORT WAVE WILL MOVE FROM LWR MI TO THE ERN LAKES OVERNIGHT. THIS WAVE WAS SUPPORTING SOME ISLD SHRA IN SRN ONTARIO AND EVEN INTO WRN PA WHERE UPSLOPING WAS ENHANCING LIFT. THIS WAVE WILL SPREAD SOME ISLD SHRA INTO THE FINGER LAKES REGION OVERNIGHT BUT DRIER AIR FARTHER E WILL IMPEDE THE PROGRESS OF THESE SHRA FARTHER E. FOR MONDAY...THE ABOVE MENTIONED WAVE WILL PASS EAST AND SUPPORT THE DEVELOPMENT OF ISLD TO SCT SHRA AND TSRA BY LATE MORNING/EARLY AFTERNOON AND THEN OUTRUN THE LL MOISTURE AND INSTABILITY AXIS AS THE LARGE HIGH PRESSURE OFF THE E COAST REMAINS INTACT. SO WE HAVE 20-30 POPS FOR ISLD SHRA AND TSRA MAINLY IN THE AFTERNOON. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... MAINLY QUIET WEATHER CONTINUES ON TUESDAY AS WEAK UPPER LEVEL RIDGING GRADUALLY BUILDS IN FROM THE SOUTHWEST. MEANWHILE SURFACE HIGH PRESSURE WILL BE SETTING UP OVER BERMUDA. THE RESULT WILL BE QUITE WARM AND HUMID WEATHER FOR TUESDAY WITH NOTHING MORE THAN A FEW ISOLATED AFTERNOON SHOWERS OR THUNDERSTORMS. HAVE GONE WITH POPS IN THE 20 PERCENT RANGE TO ACCOUNT FOR THIS SCENARIO ON TUESDAY AFTERNOON. TEMPERATURES MAY APPROACH 90 IN SOME LOWER ELEVATION AND URBANIZED LOCATIONS ON TUESDAY... WITH MID TO UPPER 80S IN MOST PLACES. THE MAIN WEATHER FEATURE TO WATCH DURING THIS PERIOD WILL BE A COLD FRONT APPROACHING THE AREA ON WEDNESDAY. THE NAM/GFS AND ECMWF ARE ALL IN PRETTY GOOD AGREEMENT WITH THE TIMING OF THIS FEATURE FOR LATE WEDNESDAY. WITH FALLING HEIGHTS AND VERY WARM HUMID AIR AT THE SURFACE THERE IS LIKELY TO BE THE DEVELOPMENT OF MODERATE INSTABILITY AHEAD OF THIS FRONTAL SYSTEM. WIND FIELDS SHOULD ALSO BE INCREASING AS THE FRONT AND UPPER TROUGH APPROACH FROM THE WEST. THIS WILL SET THE STAGE FOR A BETTER CHANCE OF THUNDERSTORMS ON WEDNESDAY. DUE TO LONG LEAD TIME HAVE NOT YET MENTIONED SEVERE POTENTIAL IN THE HWO WITH THIS SYSTEM BUT IF THE MODELS REMAIN CONSISTENT THIS POTENTIAL WILL HAVE TO BE ADDRESSED SOON. && .LONG TERM /THURSDAY THROUGH SUNDAY/... COLD FRONT WILL MOVE EAST OF THE AREA ON WEDNESDAY NIGHT FOLLOWED BY COOLER AND DRYER WEATHER THURSDAY AND FRIDAY. AT THIS POINT IT APPEARS THAT THE DRY WEATHER MAY HOLD WELL INTO THE WEEKEND BEFORE THE NEXT SYSTEM DEVELOPS AND HEADS OUR WAY EARLY NEXT WEEK. THE GFS/ECMWF ARE IN GOOD AGREEMENT WITH THIS SCENARIO AND CONFIDENCE IS ABOVE AVERAGE. TEMPERATURES DURING THE LATE WEEK WILL BE IN THE 70S DURING THE DAY AND 50S AT NIGHT... THEN SLOWLY WARMING OVER THE WEEKEND. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... VFR CONDITIONS WILL PREVAIL UNDER AN EVOLVING CUMULUS LAYER BETWEEN 4 AND 6 KFT UNDER SOME THINNER HIGHER CLDS THIS AFTERNOON/ERLY EVE. THE FLOW WAS DIRECTING MOST OF THE LL MOISTURE AND OVC LAYER TO WRN NY AND WRN PA AT THIS TIME LEADING TO MORE SUNSHINE THAN EXPECTED. THUS WE WILL SEE MORE VFR DIURNALLY DRIVEN CUMULUS THAT WILL FALL APART ARND SUNSET. THEN THE LL FLOW REMAIN SRLY OVERNIGHT WHICH WILL ADVECT A LITTLE COOLER AND DRIER AIR BELOW A MOIST LAYER ALOFT. THIS CUD LEAD TO A LOWER CLD DECK ADVECTING NORTHWESTARD OVERNIGHT. MODEL SOUNDINGS HINT AT THIS. ALL GUIDC ALSO HINTS THAT AT LEAST AN MVFR CIG AND/OR VSBY LAYER WILL WORK NORTHWESTARD REACHING KAVP...KBGM...KELM AND KITH 8-9Z OR SO. CONFIDENCE IS NOT VERY HIGH THAT IFR WILL OCCUR IN THIS LL MOISTURE BUT DO HAVE 2SM BR AT KELM 9-13Z. GUIDC WAS DROPPING KELM TO VLIFR WHICH AT THIS TIME IS NOT SUPPORTED BY OUR LOCAL ELMIRA FOG CHECKLIST OR THE SYNOPTIC PATTERN. FOR KRME AND KSYR I SEE MAYBE A BKN 5000 FOOT DECK LATE. AFTER SUNRISE THERE WILL LIKELY BE SOME SHRA FORMING BUT COVERAGE DOES NOT WARRANT MENTION IN TAFS THIS FAR OUT ESPECIALLY SINCE RESTRICTIONS ARE TOO UNCERTAIN THIS FAR OUT. SO FOR NOW I JUST PUT A 5000 FOOT CUMULUS LAYER IN TAFS LATE MON AM. WINDS LIGHT OUT OF THE S/SE AT 5-8 KNOTS THIS AFTERNOON DIMINISHING AFTER SUNSET WITH MORE WSW UNDER 10 KNOTS SUN AM. OUTLOOK... MONDAY NIGHT THROUGH TUESDAY NIGHT...MAINLY VFR...BUT BRIEF RESTRICTIONS POSSIBLE IN ISOLATED SHRA/TSRA MAINLY LATE AFTN/EVNG. WED/THURSDAY...RESTRICTIONS LIKELY IN SHOWERS/THUNDERSTORMS. FRIDAY...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MSE NEAR TERM...DJN SHORT TERM...MSE LONG TERM...MSE AVIATION...DJN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
252 PM EDT SUN JUL 20 2014 .SYNOPSIS... HIGH PRESSURE CONTINUES TO REMAIN IN CONTROL THROUGH TUESDAY. EACH AFTERNOON AND EVENING THERE WILL BE A CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS WHICH WILL END SHORTLY AFTER SUNSET. WEDNESDAY A STORM SYSTEM WILL APPROACH THE REGION FROM THE WEST BRINGING A BETTER SHOT FOR SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH MONDAY/... ISLD SHRA WERE RAPIDLY HEADING INTO NRN NY AS SHRT WAVE MOVES INTO NRN NEW ENGLAND. WATER VAPOR IMAGERY AND LATEST RAP FIELDS SHOW ANOTHER SHORT WAVE WILL MOVE FROM LWR MI TO THE ERN LAKES OVERNIGHT. THIS WAVE WAS SUPPORTING SOME ISLD SHRA IN SRN ONTARIO AND EVEN INTO WRN PA WHERE UPSLOPING WAS ENHANCING LIFT. THIS WAVE WILL SPREAD SOME ISLD SHRA INTO THE FINGER LAKES REGION OVERNIGHT BUT DRIER AIR FARTHER E WILL IMPEDE THE PROGRESS OF THESE SHRA FARTHER E. FOR MONDAY...THE ABOVE MENTIONED WAVE WILL PASS EAST AND SUPPORT THE DEVELOPMENT OF ISLD TO SCT SHRA AND TSRA BY LATE MORNING/EARLY AFTERNOON AND THEN OUTRUN THE LL MOISTURE AND INSTABILITY AXIS AS THE LARGE HIGH PRESSURE OFF THE E COAST REMAINS INTACT. SO WE HAVE 20-30 POPS FOR ISLD SHRA AND TSRA MAINLY IN THE AFTERNOON. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... 200 AM EDT UPDATE... MONDAY THE SFC RIDGE WILL CONTINUE TO INFLUENCE OUR WEATHER OVER THE NORTHEAST AS THE SECOND WEAK SHORTWAVE TROUGH SLOWLY SLIDES ACROSS THE NORTHEAST. THE SFC RIDGE WILL HELP AID IN SUBSIDENCE OVER THE REGION MAKING WHAT CONVECTION THAT DEVELOPS REMAIN SCATTERED TO ISOLATED. THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE MONDAY AND TUESDAY AS WEAK WAVES MOVE ACROSS THE REGION AND LOW LVL MOISTURE RETURNS TO THE AREA EVEN THOUGH A SFC RIDGE IS IN PLACE. EACH AFTERNOON/EVENING PRIMARILY DUE TO DIURNAL HEATING AND TOPOGRAPHIC RESPONSES SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE. THEY ARE EXPECTED TO DISSIPATE SHORTLY AFTER SUNSET. A WARMING TREND WILL OCCUR IN TEMPS DURING THIS TIME FRAME AS HEIGHT THICKNESSES CONTINUE TO RISE. MONDAY TEMPS WILL RISE INTO THE LOW TO MID 80S... AND BY TUES TEMPS WILL RISE INTO THE MID TO UPPR 80S. TUESDAY MAY FEEL QUITE MUGGY AS DEW PTS WILL RISE INTO THE MID 60S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... 245 AM UPDATE... MED RANGE MODELS CONTINUE TO AGREE ON PROGRESSION OF FRONTAL BNDRY BY MID-WEEK. ONLY DISCREPANCY IS GFS HAS SFC LOPRES RIDING THRU CWA WED NGT LEADING TO POTENTIAL HVY RAIN EVENT WHEREAS EC BRINGS FROPA THRU RAPIDLY. DIFFERENCES SURROUND STRONG S/WV BEING SHOWN BY GFS WHEREAS EC IS JUST A TROF MVG THRU THE NORTHEAST. APPEARS TO BE THAT GFS IS SUFFERING FM CONVECTIVE FEEDBACK WITH REGARD TO THIS FEATURE. EITHER WAY, EXPECT LKLY POPS EITHER SIDE OF 12Z THURSDAY AND HV NOT MADE ANY CHGS AT THIS POINT DUE TO UNCERTAINTY. AFT FROPA OCCURS 1020MB SFC HIGH WL BUILD IN THRU THE END OF THE WEEK RESULTING IN COOLER TEMPS. TWD THE END OF THE LONG TERM LATEST EC IS MUCH WEAKER WITH EVENTUAL UL FEATURE DROPPING INTO THE UPR MIDWEST THAN ITS 12Z RUN WAS. WL AWAIT FOR LATER GUIDANCE BFR CHANGING FCST THIS FAR OUT IN THE DAY 7/8 TIMEFRAME. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... VFR CONDITIONS WILL PREVAIL UNDER AN EVOLVING CUMULUS LAYER BETWEEN 4 AND 6 KFT UNDER SOME THINNER HIGHER CLDS THIS AFTERNOON/ERLY EVE. THE FLOW WAS DIRECTING MOST OF THE LL MOISTURE AND OVC LAYER TO WRN NY AND WRN PA AT THIS TIME LEADING TO MORE SUNSHINE THAN EXPECTED. THUS WE WILL SEE MORE VFR DIURNALLY DRIVEN CUMULUS THAT WILL FALL APART ARND SUNSET. THEN THE LL FLOW REMAIN SRLY OVERNIGHT WHICH WILL ADVECT A LITTLE COOLER AND DRIER AIR BELOW A MOIST LAYER ALOFT. THIS CUD LEAD TO A LOWER CLD DECK ADVECTING NORTHWESTARD OVERNIGHT. MODEL SOUNDINGS HINT AT THIS. ALL GUIDC ALSO HINTS THAT AT LEAST AN MVFR CIG AND/OR VSBY LAYER WILL WORK NORTHWESTARD REACHING KAVP...KBGM...KELM AND KITH 8-9Z OR SO. CONFIDENCE IS NOT VERY HIGH THAT IFR WILL OCCUR IN THIS LL MOISTURE BUT DO HAVE 2SM BR AT KELM 9-13Z. GUIDC WAS DROPPING KELM TO VLIFR WHICH AT THIS TIME IS NOT SUPPORTED BY OUR LOCAL ELMIRA FOG CHECKLIST OR THE SYNOPTIC PATTERN. FOR KRME AND KSYR I SEE MAYBE A BKN 5000 FOOT DECK LATE. AFTER SUNRISE THERE WILL LIKELY BE SOME SHRA FORMING BUT COVERAGE DOES NOT WARRANT MENTION IN TAFS THIS FAR OUT ESPECIALLY SINCE RESTRICTIONS ARE TOO UNCERTAIN THIS FAR OUT. SO FOR NOW I JUST PUT A 5000 FOOT CUMULUS LAYER IN TAFS LATE MON AM. WINDS LIGHT OUT OF THE S/SE AT 5-8 KNOTS THIS AFTERNOON DIMINISHING AFTER SUNSET WITH MORE WSW UNDER 10 KNOTS SUN AM. OUTLOOK... MONDAY NIGHT THROUGH TUESDAY NIGHT...MAINLY VFR...BUT BRIEF RESTRICTIONS POSSIBLE IN ISOLATED SHRA/TSRA MAINLY LATE AFTN/EVNG. WED/THURSDAY...RESTRICTIONS LIKELY IN SHOWERS/THUNDERSTORMS. FRIDAY...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DJN/KAH NEAR TERM...DJN SHORT TERM...KAH LONG TERM...PVN AVIATION...DJN
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1041 AM EDT SUN JUL 20 2014 .SYNOPSIS... A FEW LIGHT SCATTERED RAIN SHOWERS ARE POSSIBLE ACROSS PORTIONS OF NORTHERN NEW YORK THIS AFTERNOON. HIGH TEMPERATURES WILL BE RIGHT AROUND SEASONAL NORMALS ONCE AGAIN. A WARMING TREND WILL BEGIN ON MONDAY AND CONTINUE RIGHT INTO MIDWEEK. OTHER THAN A FEW SHOWERS POSSIBLE OVER NORTHERN NEW YORK MONDAY AFTERNOON...DRY WEATHER IS EXPECTED THROUGH TUESDAY. A COLD FRONT WILL MOVE INTO THE REGION ON WEDNESDAY AND INCREASE THE CHANCES FOR THUNDERSTORMS...SOME OF WHICH COULD BE ON THE STRONG SIDE. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 1040 AM EDT SUNDAY...VISIBLE SATELLITE LOOP SHOWING SUNNY SKIES ACROSS NORTHERN NEW YORK AND NORTHERN VERMONT AT THIS TIME. HOWEVER...CUMULUS CLOUDS ARE DEVELOPING ACROSS THE ADIRONDACKS AT THIS TIME AS WELL AS ALONG THE WESTERN SLOPES OF THE GREEN MOUNTAINS. EXPECTING SKIES TO BECOME PARTLY SUNNY IN THESE AREAS BY EARLY THIS AFTERNOON. HAVE ADJUSTED SKY GRIDS TO ACCOUNT FOR THIS. LIGHT RAIN SHOWERS THAT WERE OVER SOUTHEASTERN VERMONT EARLIER THIS MORNING HAVE MOVED NORTHEAST INTO CENTRAL NEW HAMPSHIRE AND WESTERN MAINE AT THIS TIME. RADAR SHOWING SOME SCATTERED LIGHT RAIN SHOWERS ACROSS CENTRAL AND WESTERN NEW YORK STATE AT THIS TIME. HAVE GONE WITH SLIGHT CHANCE POPS FOR SCATTERED LIGHT RAIN SHOWERS THIS AFTERNOON ACROSS THE SAINT LAWRENCE VALLEY AND THE ADIRONDACKS. PREVIOUS DISCUSSION FROM 732 AM EDT SUNDAY...GOING FORECAST IN GOOD SHAPE WITH JUST SOME MINOR TEMPERATURE CHANGES TO MATCH CURRENT CONDITIONS BETTER. SOME NOTICEABLE HOLES IN THE CLOUD COVER HAVE TEMPERATURES WARMING A BIT QUICKER. OTHERWISE... WELL DEFINED SHORTWAVE TROUGH MOVING INTO SOUTHERN NEW ENGLAND THIS MORNING IS ENHANCING AN AREA OF RAIN SHOWERS. THESE SHOWERS MIGHT CLIP PORTIONS OF SOUTH CENTRAL VERMONT THIS MORNING...THUS HAVE MENTIONED A SLIGHT CHANCE OF SHOWERS SOUTH AND EAST OF THE RUTLAND AREA. ELSEWHERE...WEAK UPPER TROUGH REMAINS OVER WESTERN QUEBEC AND WESTERN NEW YORK EARLY THIS MORNING...WHICH IS HELPING TO PRODUCE A FEW LIGHT RAIN SHOWERS AHEAD OF IT. GOING FORECAST OF A SLIGHT CHANCE OF SHOWERS TODAY FOR NORTHERN NEW YORK MAKES SENSE WITH RAINFALL AMOUNTS OF LESS THAN A TENTH OF AN INCH. BETWEEN THESE TWO AREAS...EXPECTING MID AND HIGH LEVEL CLOUDS TO MOVE ACROSS THE AREA. HIGH TEMPERATURES WILL ONCE AGAIN BE RIGHT AROUND SEASONAL NORMALS. && .SHORT TERM /8 PM THIS EVENING THROUGH TUESDAY/... AS OF 420 AM EDT SUNDAY...ANY LIGHT SHOWERS OVER NORTHERN NEW YORK COME TO AN END DURING THE EVENING HOURS WITH DRY CONDITIONS ELSEWHERE. WARMER 925 MILLIBAR TEMPERATURES WILL MOVE INTO THE AREA ON MONDAY AND WE SHOULD SEE THE DEW POINTS INCREASE A BIT AS WELL. SO NOT ONLY WILL THIS MEAN WARMER TEMPERATURES...HIGHS IN THE UPPER 70S TO MID 80S...BUT INSTABILITY WILL ALSO BE INCREASING...ESPECIALLY OVER NORTHERN NEW YORK. LINGERING WEAK UPPER LEVEL TROUGH MAY PROVIDE JUST ENOUGH FORCING...HIGHER TERRAIN FOR THAT MATTER AS WELL...WHEN COMBINED WITH THE INSTABILITY COULD PRODUCE SOME AFTERNOON SHOWERS OVER NORTHERN NEW YORK. HAVE KEPT THIS IDEA GOING IN THE FORECAST. AGAIN...ANY SHOWERS END BY EVENING WITH DRY WEATHER EXPECTED ELSEWHERE. WEAK RIDGING ALOFT MOVES IN ON TUESDAY AND LOW LEVEL TEMPERATURES WARM EVEN FURTHER. THUS EXPECTING DRY WEATHER ALL AREAS WITH HIGH TEMPERATURES IN THE 80S TO AROUND 90...WITH INCREASING DEW POINTS TO CREATE HIGHER HUMIDITIES. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 400 AM EDT SUNDAY...BEST CHANCE FOR THUNDERSTORMS WILL BE WEDNESDAY AFTERNOON/EVENING...WITH SOME STRONG STORMS POSSIBLE. OVERALL LITTLE CHANGE FROM PREVIOUS COUPLE OF FORECAST AND MODELS CONT TO BE IN GOOD AGREEMENT WITH TIMING OF SYSTEM FOR WEDS...BUT SHOW SOME DIFFERENCE TOWARD THE END OF THIS UPCOMING WEEK. A WARM AND MUGGY NIGHT IS ANTICIPATED ON TUES...WITH SOUTHERLY FLOW AND SURFACE DEW POINTS IN THE 60S. LOWS BY WEDS MORNING WILL RANGE FROM THE U50S MOUNTAINS/NORTHEAST KINGDOM TO NEAR 70F IN THE CHAMPLAIN VALLEY AND SAINT LAWRENCE VALLEY. WEDNESDAY WILL START OUT DRY WITH BREEZY WARM SOUTHERLY WINDS...ADVECTING 85H TEMPS TO 17C...SUPPORTING HIGHS WELL INTO THE 80S TO LOWER 90S WARMER VALLEY REGIONS. THIS HEAT...WILL RESULT IN SURFACE BASED CAPE VALUES BETWEEN 1200 AND 1800 J/KG AND LI VALUES BETWEEN -3 AND -5 BY WEDNESDAY AFTERNOON. AS POTENT 5H VORT APPROACHES OUR FORECAST AREA ASSOCIATED WITH MID/UPPER LEVEL TROF AND SURFACE COLD FRONT...SCATTERED TO NUMEROUS SHOWERS/STORMS WILL DEVELOP AFT 18Z WEDS AND CONTINUE INTO THE EVENING HOURS. HAVE MENTION LIKELY POPS FROM 18Z WEDS TO 06Z THURSDAY...BUT IT SHOULD BE POINTED OUT A PERIOD OF ONLY 1 TO 2 HRS OF RAIN IS EXPECTED DURING THIS 12 HR WINDOW. SOUNDING PROFILES CONT TO SHOW A UNIDIRECTIONAL WIND PROFILE THRU 500MB...WITH MODERATE VELOCITIES RESULTING IN 0 TO 6 KM SHEAR VALUES BETWEEN 30 AND 40 KNOTS. THIS COMBINED WITH THE DYNAMICS/INSTABILITY PARAMETERS SUPPORTS THE POTENTIAL FOR STRONGER STORMS WITH SOME ORGANIZED LINE SEGMENTS POSSIBLE. WILL CONTINUE TO HIGHLIGHT IN CURRENT HWO ON STORM POTENTIAL. IN ADDITION...WITH PWS BETWEEN 1.50 AND 1.80" AND WARM CLOUD DEPTHS NEAR 11,500 FEET...LOCALIZED HEAVY DOWN POURS ARE LIKELY...BUT GIVEN EXPECTED STORM MOTIONS AND RECENT DRY SPELL...MINIMAL HYDRO ISSUES ARE ANTICIPATED. BY 12Z THURS BEST 5H PVA IS LOCATED ACROSS SOUTHERN CANADA...WHILE MID/UPPER LEVEL TROF AXIS IS APPROACHING OUR WESTERN FORECAST AREA. THIS COMBINED WITH ENHANCED 850 TO 500MB MOISTURE ACROSS OUR NORTHERN/EASTERN SECTION WILL CONT TO MENTION CHANCE POPS ON THURSDAY. IF SYSTEM CONTINUES TO SHOW ADDITIONAL MOISTURE LAGGING BEHIND AND FAVORABLE DYNAMICS ALOFT...THESE POPS WILL NEED TO BE ADJUSTED UPWARD TO LIKELY...BUT STILL SOME UNCERTAINTY. DRY AND COOLER AIR ARRIVES BY FRIDAY INTO SATURDAY WITH TROF OVERHEAD AND BUILD SURFACE HIGH PRESSURE. TEMPERATURES WILL DROP BACK TO NEAR NORMAL LEVELS WITH MUCH LESS HUMIDITY BY FRIDAY. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... THROUGH 12Z MONDAY...IR SATL SHOWS MID/UPPER LVL CLOUDS SLOWLY DEVELOPING ACRS OUR TAF SITES THIS MORNING ASSOCIATED WITH A WEAK 5H TROF...UNDER CUTTING HIGH PRES. THIS HAS PRODUCED SOME VERY LIGHT RAIN SHOWERS ACRS WESTERN NY AND PARTS OF SOUTHERN VT/WESTERN MA THIS MORNING...BUT SHOULD PASS BY OUR TAF SITES WITH LITTLE IMPACT. MAYBE A SPRINKLE AT RUTLAND AND MSS BTWN 14Z-18Z TODAY. OTHERWISE...VFR CONDITIONS WL PREVAIL WITH A SCATTERED TO BROKEN MID LVL CLOUD DECK. WINDS WL BE GENERALLY FROM THE SOUTH AT 4 TO 8 KNOTS WITH SOME LOCALIZED LAKE INFLUENCE AT PBG FROM THE SOUTHEAST. TONIGHT WINDS WL BE BECOME LIGHT AND TRRN DRIVEN...WHICH MEANS SE AT RUTLAND AROUND 6 KNOTS. OTHERWISE...HAVE NOTED A LLVL JET OFF THE LATEST RAP OF 15 TO 20 KNOTS ONLY 200 TO 400 FEET AGL...WHICH MAY LIMIT FOG/BR DEVELOPMENT...ALONG WITH THE EXPECTED CLOUD COVER. THIS WL BE TRICKY AS SFC MOISTURE CONTS TO INCREASE WITH DWPT TEMPS CLIMBING INTO THE 50S WITH ISOLATED POCKETS IN THE L60S POSSIBLE. OUTLOOK 12Z MONDAY THROUGH THURSDAY... MAINLY VFR CONDITIONS WITH AN ISOLATED SHOWER POSSIBLE MONDAY AFTERNOON. SOME LOCALIZED PATCHY FOG/BR WILL BE POSSIBLE WITH IFR CONDITIONS AT SLK/MPV MONDAY AND TUESDAY MORNINGS...ESPECIALLY AS LLVL MOISTURE INCREASES. A SURFACE COLD FRNT WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS/STORMS ON WEDS AFTERNOON/EVENING WITH LOCALIZED MVFR IN THE HEAVIER THUNDERSTORM ACTIVITY. SOME LOCALIZED GUSTY WINDS WILL BE POSSIBLE...CREATING AREAS OF TURBULENCE AND WIND SHEAR. SCATTERED SHOWERS WILL CONT INTO THURSDAY WITH MAINLY VFR CONDITIONS WITH EXCEPTION OF OCCASIONAL MVFR CIGS...IN OUR MTN TAF SITES OF MPV/SLK. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...EVENSON NEAR TERM...EVENSON/WGH SHORT TERM...EVENSON LONG TERM...TABER AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
732 AM EDT SUN JUL 20 2014 .SYNOPSIS... A FEW LIGHT RAIN SHOWERS ARE POSSIBLE OVER SOUTH CENTRAL VERMONT THIS MORNING AND ACROSS PORTIONS OF NORTHERN NEW YORK THROUGH LATE AFTERNOON. RAINFALL AMOUNTS WILL BE RELATIVELY LIGHT WITH MAINLY CLOUDS EXPECTED ELSEWHERE. HIGH TEMPERATURES WILL BE RIGHT AROUND SEASONAL NORMALS ONCE AGAIN. A WARMING TREND WILL BEGIN ON MONDAY AND CONTINUE RIGHT INTO MIDWEEK. OTHER THAN A FEW SHOWERS POSSIBLE OVER NORTHERN NEW YORK MONDAY AFTERNOON...DRY WEATHER IS EXPECTED THROUGH TUESDAY. A COLD FRONT WILL MOVE INTO THE REGION ON WEDNESDAY AND INCREASE THE CHANCES FOR THUNDERSTORMS...SOME OF WHICH COULD BE ON THE STRONG SIDE. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 732 AM EDT SUNDAY...GOING FORECAST IN GOOD SHAPE WITH JUST SOME MINOR TEMPERATURE CHANGES TO MATCH CURRENT CONDITIONS BETTER. SOME NOTICEABLE HOLES IN THE CLOUD COVER HAVE TEMPERATURES WARMING A BIT QUICKER. OTHERWISE... WELL DEFINED SHORTWAVE TROUGH MOVING INTO SOUTHERN NEW ENGLAND THIS MORNING IS ENHANCING AN AREA OF RAIN SHOWERS. THESE SHOWERS MIGHT CLIP PORTIONS OF SOUTH CENTRAL VERMONT THIS MORNING...THUS HAVE MENTIONED A SLIGHT CHANCE OF SHOWERS SOUTH AND EAST OF THE RUTLAND AREA. ELSEWHERE...WEAK UPPER TROUGH REMAINS OVER WESTERN QUEBEC AND WESTERN NEW YORK EARLY THIS MORNING...WHICH IS HELPING TO PRODUCE A FEW LIGHT RAIN SHOWERS AHEAD OF IT. GOING FORECAST OF A SLIGHT CHANCE OF SHOWERS TODAY FOR NORTHERN NEW YORK MAKES SENSE WITH RAINFALL AMOUNTS OF LESS THAN A TENTH OF AN INCH. BETWEEN THESE TWO AREAS...EXPECTING MID AND HIGH LEVEL CLOUDS TO MOVE ACROSS THE AREA. HIGH TEMPERATURES WILL ONCE AGAIN BE RIGHT AROUND SEASONAL NORMALS. && .SHORT TERM /8 PM THIS EVENING THROUGH TUESDAY/... AS OF 420 AM EDT SUNDAY...ANY LIGHT SHOWERS OVER NORTHERN NEW YORK COME TO AN END DURING THE EVENING HOURS WITH DRY CONDITIONS ELSEWHERE. WARMER 925 MILLIBAR TEMPERATURES WILL MOVE INTO THE AREA ON MONDAY AND WE SHOULD SEE THE DEW POINTS INCREASE A BIT AS WELL. SO NOT ONLY WILL THIS MEAN WARMER TEMPERATURES...HIGHS IN THE UPPER 70S TO MID 80S...BUT INSTABILITY WILL ALSO BE INCREASING...ESPECIALLY OVER NORTHERN NEW YORK. LINGERING WEAK UPPER LEVEL TROUGH MAY PROVIDE JUST ENOUGH FORCING...HIGHER TERRAIN FOR THAT MATTER AS WELL...WHEN COMBINED WITH THE INSTABILITY COULD PRODUCE SOME AFTERNOON SHOWERS OVER NORTHERN NEW YORK. HAVE KEPT THIS IDEA GOING IN THE FORECAST. AGAIN...ANY SHOWERS END BY EVENING WITH DRY WEATHER EXPECTED ELSEWHERE. WEAK RIDGING ALOFT MOVES IN ON TUESDAY AND LOW LEVEL TEMPERATURES WARM EVEN FURTHER. THUS EXPECTING DRY WEATHER ALL AREAS WITH HIGH TEMPERATURES IN THE 80S TO AROUND 90...WITH INCREASING DEW POINTS TO CREATE HIGHER HUMIDITIES. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 400 AM EDT SUNDAY...BEST CHANCE FOR THUNDERSTORMS WILL BE WEDNESDAY AFTERNOON/EVENING...WITH SOME STRONG STORMS POSSIBLE. OVERALL LITTLE CHANGE FROM PREVIOUS COUPLE OF FORECAST AND MODELS CONT TO BE IN GOOD AGREEMENT WITH TIMING OF SYSTEM FOR WEDS...BUT SHOW SOME DIFFERENCE TOWARD THE END OF THIS UPCOMING WEEK. A WARM AND MUGGY NIGHT IS ANTICIPATED ON TUES...WITH SOUTHERLY FLOW AND SURFACE DEW POINTS IN THE 60S. LOWS BY WEDS MORNING WILL RANGE FROM THE U50S MOUNTAINS/NORTHEAST KINGDOM TO NEAR 70F IN THE CHAMPLAIN VALLEY AND SAINT LAWRENCE VALLEY. WEDNESDAY WILL START OUT DRY WITH BREEZY WARM SOUTHERLY WINDS...ADVECTING 85H TEMPS TO 17C...SUPPORTING HIGHS WELL INTO THE 80S TO LOWER 90S WARMER VALLEY REGIONS. THIS HEAT...WILL RESULT IN SURFACE BASED CAPE VALUES BETWEEN 1200 AND 1800 J/KG AND LI VALUES BETWEEN -3 AND -5 BY WEDNESDAY AFTERNOON. AS POTENT 5H VORT APPROACHES OUR FORECAST AREA ASSOCIATED WITH MID/UPPER LEVEL TROF AND SURFACE COLD FRONT...SCATTERED TO NUMEROUS SHOWERS/STORMS WILL DEVELOP AFT 18Z WEDS AND CONTINUE INTO THE EVENING HOURS. HAVE MENTION LIKELY POPS FROM 18Z WEDS TO 06Z THURSDAY...BUT IT SHOULD BE POINTED OUT A PERIOD OF ONLY 1 TO 2 HRS OF RAIN IS EXPECTED DURING THIS 12 HR WINDOW. SOUNDING PROFILES CONT TO SHOW A UNIDIRECTIONAL WIND PROFILE THRU 500MB...WITH MODERATE VELOCITIES RESULTING IN 0 TO 6 KM SHEAR VALUES BETWEEN 30 AND 40 KNOTS. THIS COMBINED WITH THE DYNAMICS/INSTABILITY PARAMETERS SUPPORTS THE POTENTIAL FOR STRONGER STORMS WITH SOME ORGANIZED LINE SEGMENTS POSSIBLE. WILL CONTINUE TO HIGHLIGHT IN CURRENT HWO ON STORM POTENTIAL. IN ADDITION...WITH PWS BETWEEN 1.50 AND 1.80" AND WARM CLOUD DEPTHS NEAR 11,500 FEET...LOCALIZED HEAVY DOWN POURS ARE LIKELY...BUT GIVEN EXPECTED STORM MOTIONS AND RECENT DRY SPELL...MINIMAL HYDRO ISSUES ARE ANTICIPATED. BY 12Z THURS BEST 5H PVA IS LOCATED ACROSS SOUTHERN CANADA...WHILE MID/UPPER LEVEL TROF AXIS IS APPROACHING OUR WESTERN FORECAST AREA. THIS COMBINED WITH ENHANCED 850 TO 500MB MOISTURE ACROSS OUR NORTHERN/EASTERN SECTION WILL CONT TO MENTION CHANCE POPS ON THURSDAY. IF SYSTEM CONTINUES TO SHOW ADDITIONAL MOISTURE LAGGING BEHIND AND FAVORABLE DYNAMICS ALOFT...THESE POPS WILL NEED TO BE ADJUSTED UPWARD TO LIKELY...BUT STILL SOME UNCERTAINTY. DRY AND COOLER AIR ARRIVES BY FRIDAY INTO SATURDAY WITH TROF OVERHEAD AND BUILD SURFACE HIGH PRESSURE. TEMPERATURES WILL DROP BACK TO NEAR NORMAL LEVELS WITH MUCH LESS HUMIDITY BY FRIDAY. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... THROUGH 12Z MONDAY...IR SATL SHOWS MID/UPPER LVL CLOUDS SLOWLY DEVELOPING ACRS OUR TAF SITES THIS MORNING ASSOCIATED WITH A WEAK 5H TROF...UNDER CUTTING HIGH PRES. THIS HAS PRODUCED SOME VERY LIGHT RAIN SHOWERS ACRS WESTERN NY AND PARTS OF SOUTHERN VT/WESTERN MA THIS MORNING...BUT SHOULD PASS BY OUR TAF SITES WITH LITTLE IMPACT. MAYBE A SPRINKLE AT RUTLAND AND MSS BTWN 14Z-18Z TODAY. OTHERWISE...VFR CONDITIONS WL PREVAIL WITH A SCATTERED TO BROKEN MID LVL CLOUD DECK. WINDS WL BE GENERALLY FROM THE SOUTH AT 4 TO 8 KNOTS WITH SOME LOCALIZED LAKE INFLUENCE AT PBG FROM THE SOUTHEAST. TONIGHT WINDS WL BE BECOME LIGHT AND TRRN DRIVEN...WHICH MEANS SE AT RUTLAND AROUND 6 KNOTS. OTHERWISE...HAVE NOTED A LLVL JET OFF THE LATEST RAP OF 15 TO 20 KNOTS ONLY 200 TO 400 FEET AGL...WHICH MAY LIMIT FOG/BR DEVELOPMENT...ALONG WITH THE EXPECTED CLOUD COVER. THIS WL BE TRICKY AS SFC MOISTURE CONTS TO INCREASE WITH DWPT TEMPS CLIMBING INTO THE 50S WITH ISOLATED POCKETS IN THE L60S POSSIBLE. OUTLOOK 12Z MONDAY THROUGH THURSDAY... MAINLY VFR CONDITIONS WITH AN ISOLATED SHOWER POSSIBLE MONDAY AFTERNOON. SOME LOCALIZED PATCHY FOG/BR WILL BE POSSIBLE WITH IFR CONDITIONS AT SLK/MPV MONDAY AND TUESDAY MORNINGS...ESPECIALLY AS LLVL MOISTURE INCREASES. A SURFACE COLD FRNT WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS/STORMS ON WEDS AFTERNOON/EVENING WITH LOCALIZED MVFR IN THE HEAVIER THUNDERSTORM ACTIVITY. SOME LOCALIZED GUSTY WINDS WILL BE POSSIBLE...CREATING AREAS OF TURBULENCE AND WIND SHEAR. SCATTERED SHOWERS WILL CONT INTO THURSDAY WITH MAINLY VFR CONDITIONS WITH EXCEPTION OF OCCASIONAL MVFR CIGS...IN OUR MTN TAF SITES OF MPV/SLK. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...EVENSON NEAR TERM...EVENSON SHORT TERM...EVENSON LONG TERM...TABER AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
702 AM EDT SUN JUL 20 2014 .SYNOPSIS... A FEW LIGHT RAIN SHOWERS ARE POSSIBLE OVER SOUTH CENTRAL VERMONT THIS MORNING AND ACROSS PORTIONS OF NORTHERN NEW YORK THROUGH LATE AFTERNOON. RAINFALL AMOUNTS WILL BE RELATIVELY LIGHT WITH MAINLY CLOUDS EXPECTED ELSEWHERE. HIGH TEMPERATURES WILL BE RIGHT AROUND SEASONAL NORMALS ONCE AGAIN. A WARMING TREND WILL BEGIN ON MONDAY AND CONTINUE RIGHT INTO MIDWEEK. OTHER THAN A FEW SHOWERS POSSIBLE OVER NORTHERN NEW YORK MONDAY AFTERNOON...DRY WEATHER IS EXPECTED THROUGH TUESDAY. A COLD FRONT WILL MOVE INTO THE REGION ON WEDNESDAY AND INCREASE THE CHANCES FOR THUNDERSTORMS...SOME OF WHICH COULD BE ON THE STRONG SIDE. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 420 AM EDT SUNDAY...WELL DEFINED SHORTWAVE TROUGH MOVING NORTHEAST ACROSS THE MID-ATLANTIC REGION EARLY THIS MORNING IS ENHANCING AN AREA OF RAIN SHOWERS. THESE SHOWERS MIGHT CLIP PORTIONS OF SOUTH CENTRAL VERMONT THIS MORNING...THUS HAVE MENTIONED A SLIGHT CHANCE OF SHOWERS SOUTH AND EAST OF THE RUTLAND AREA. ELSEWHERE...WEAK UPPER TROUGH REMAINS OVER WESTERN QUEBEC AND WESTERN NEW YORK EARLY THIS MORNING...WHICH IS HELPING TO PRODUCE A FEW LIGHT RAIN SHOWERS AHEAD OF IT. GOING FORECAST OF A SLIGHT CHANCE OF SHOWERS TODAY FOR NORTHERN NEW YORK MAKES SENSE WITH RAINFALL AMOUNTS OF LESS THAN A TENTH OF AN INCH. BETWEEN THESE TWO AREAS...EXPECTING MID AND HIGH LEVEL CLOUDS TO MOVE ACROSS THE AREA. HIGH TEMPERATURES WILL ONCE AGAIN BE RIGHT AROUND SEASONAL NORMALS. && .SHORT TERM /8 PM THIS EVENING THROUGH TUESDAY/... AS OF 420 AM EDT SUNDAY...ANY LIGHT SHOWERS OVER NORTHERN NEW YORK COME TO AN END DURING THE EVENING HOURS WITH DRY CONDITIONS ELSEWHERE. WARMER 925 MILLIBAR TEMPERATURES WILL MOVE INTO THE AREA ON MONDAY AND WE SHOULD SEE THE DEW POINTS INCREASE A BIT AS WELL. SO NOT ONLY WILL THIS MEAN WARMER TEMPERATURES...HIGHS IN THE UPPER 70S TO MID 80S...BUT INSTABILITY WILL ALSO BE INCREASING...ESPECIALLY OVER NORTHERN NEW YORK. LINGERING WEAK UPPER LEVEL TROUGH MAY PROVIDE JUST ENOUGH FORCING...HIGHER TERRAIN FOR THAT MATTER AS WELL...WHEN COMBINED WITH THE INSTABILITY COULD PRODUCE SOME AFTERNOON SHOWERS OVER NORTHERN NEW YORK. HAVE KEPT THIS IDEA GOING IN THE FORECAST. AGAIN...ANY SHOWERS END BY EVENING WITH DRY WEATHER EXPECTED ELSEWHERE. WEAK RIDGING ALOFT MOVES IN ON TUESDAY AND LOW LEVEL TEMPERATURES WARM EVEN FURTHER. THUS EXPECTING DRY WEATHER ALL AREAS WITH HIGH TEMPERATURES IN THE 80S TO AROUND 90...WITH INCREASING DEW POINTS TO CREATE HIGHER HUMIDITIES. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 400 AM EDT SUNDAY...BEST CHANCE FOR THUNDERSTORMS WILL BE WEDNESDAY AFTERNOON/EVENING...WITH SOME STRONG STORMS POSSIBLE. OVERALL LITTLE CHANGE FROM PREVIOUS COUPLE OF FORECAST AND MODELS CONT TO BE IN GOOD AGREEMENT WITH TIMING OF SYSTEM FOR WEDS...BUT SHOW SOME DIFFERENCE TOWARD THE END OF THIS UPCOMING WEEK. A WARM AND MUGGY NIGHT IS ANTICIPATED ON TUES...WITH SOUTHERLY FLOW AND SURFACE DEW POINTS IN THE 60S. LOWS BY WEDS MORNING WILL RANGE FROM THE U50S MOUNTAINS/NORTHEAST KINGDOM TO NEAR 70F IN THE CHAMPLAIN VALLEY AND SAINT LAWRENCE VALLEY. WEDNESDAY WILL START OUT DRY WITH BREEZY WARM SOUTHERLY WINDS...ADVECTING 85H TEMPS TO 17C...SUPPORTING HIGHS WELL INTO THE 80S TO LOWER 90S WARMER VALLEY REGIONS. THIS HEAT...WILL RESULT IN SURFACE BASED CAPE VALUES BETWEEN 1200 AND 1800 J/KG AND LI VALUES BETWEEN -3C AND -5C BY WEDS AFTERNOON. AS POTENT 5H VORT APPROACHES OUR FORECAST AREA ASSOCIATED WITH MID/UPPER LEVEL TROF AND SURFACE COLD FRONT...SCATTERED TO NUMEROUS SHOWERS/STORMS WILL DEVELOP AFT 18Z WEDS AND CONTINUE INTO THE EVENING HOURS. HAVE MENTION LIKELY POPS FROM 18Z WEDS TO 06Z THURSDAY...BUT IT SHOULD BE POINTED OUT A PERIOD OF ONLY 1 TO 2 HRS OF RAIN IS EXPECTED DURING THIS 12 HR WINDOW. SOUNDING PROFILES CONT TO SHOW A UNIDIRECTIONAL WIND PROFILE THRU 500MB...WITH MODERATE VELOCITIES RESULTING IN 0 TO 6 KM SHEAR VALUES BETWEEN 30 AND 40 KNOTS. THIS COMBINED WITH THE DYNAMICS/INSTABILITY PARAMETERS SUPPORTS THE POTENTIAL FOR STRONGER STORMS WITH SOME ORGANIZED LINE SEGMENTS POSSIBLE. WILL CONTINUE TO HIGHLIGHT IN CURRENT HWO ON STORM POTENTIAL. IN ADDITION...WITH PWS BETWEEN 1.50 AND 1.80" AND WARM CLOUD DEPTHS NEAR 11,500 FEET...LOCALIZED HEAVY DOWN POURS ARE LIKELY...BUT GIVEN EXPECTED STORM MOTIONS AND RECENT DRY SPELL...MINIMAL HYDRO ISSUES ARE ANTICIPATED. BY 12Z THURS BEST 5H PVA IS LOCATED ACROSS SOUTHERN CANADA...WHILE MID/UPPER LEVEL TROF AXIS IS APPROACHING OUR WESTERN FORECAST AREA. THIS COMBINED WITH ENHANCED 850 TO 500MB MOISTURE ACROSS OUR NORTHERN/EASTERN SECTION WILL CONT TO MENTION CHANCE POPS ON THURSDAY. IF SYSTEM CONTINUES TO SHOW ADDITIONAL MOISTURE LAGGING BEHIND AND FAVORABLE DYNAMICS ALOFT...THESE POPS WILL NEED TO BE ADJUSTED UPWARD TO LIKELY...BUT STILL SOME UNCERTAINTY. DRY AND COOLER AIR ARRIVES BY FRIDAY INTO SATURDAY WITH TROF OVERHEAD AND BUILD SURFACE HIGH PRESSURE. TEMPERATURES WILL DROP BACK TO NEAR NORMAL LEVELS WITH MUCH LESS HUMIDITY BY FRIDAY. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... THROUGH 12Z MONDAY...IR SATL SHOWS MID/UPPER LVL CLOUDS SLOWLY DEVELOPING ACRS OUR TAF SITES THIS MORNING ASSOCIATED WITH A WEAK 5H TROF...UNDER CUTTING HIGH PRES. THIS HAS PRODUCED SOME VERY LIGHT RAIN SHOWERS ACRS WESTERN NY AND PARTS OF SOUTHERN VT/WESTERN MA THIS MORNING...BUT SHOULD PASS BY OUR TAF SITES WITH LITTLE IMPACT. MAYBE A SPRINKLE AT RUTLAND AND MSS BTWN 14Z-18Z TODAY. OTHERWISE...VFR CONDITIONS WL PREVAIL WITH A SCATTERED TO BROKEN MID LVL CLOUD DECK. WINDS WL BE GENERALLY FROM THE SOUTH AT 4 TO 8 KNOTS WITH SOME LOCALIZED LAKE INFLUENCE AT PBG FROM THE SOUTHEAST. TONIGHT WINDS WL BE BECOME LIGHT AND TRRN DRIVEN...WHICH MEANS SE AT RUTLAND AROUND 6 KNOTS. OTHERWISE...HAVE NOTED A LLVL JET OFF THE LATEST RAP OF 15 TO 20 KNOTS ONLY 200 TO 400 FEET AGL...WHICH MAY LIMIT FOG/BR DEVELOPMENT...ALONG WITH THE EXPECTED CLOUD COVER. THIS WL BE TRICKY AS SFC MOISTURE CONTS TO INCREASE WITH DWPT TEMPS CLIMBING INTO THE 50S WITH ISOLATED POCKETS IN THE L60S POSSIBLE. OUTLOOK 12Z MONDAY THROUGH THURSDAY... MAINLY VFR CONDITIONS WITH AN ISOLATED SHOWER POSSIBLE MONDAY AFTERNOON. SOME LOCALIZED PATCHY FOG/BR WILL BE POSSIBLE WITH IFR CONDITIONS AT SLK/MPV MONDAY AND TUESDAY MORNINGS...ESPECIALLY AS LLVL MOISTURE INCREASES. A SURFACE COLD FRNT WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS/STORMS ON WEDS AFTERNOON/EVENING WITH LOCALIZED MVFR IN THE HEAVIER THUNDERSTORM ACTIVITY. SOME LOCALIZED GUSTY WINDS WILL BE POSSIBLE...CREATING AREAS OF TURBULENCE AND WIND SHEAR. SCATTERED SHOWERS WILL CONT INTO THURSDAY WITH MAINLY VFR CONDITIONS WITH EXCEPTION OF OCCASIONAL MVFR CIGS...IN OUR MTN TAF SITES OF MPV/SLK. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...EVENSON NEAR TERM...EVENSON SHORT TERM...EVENSON LONG TERM...TABER AVIATION...TABER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
349 PM EDT SUN JUL 20 2014 .SYNOPSIS... A LINGERING FRONT OFFSHORE WILL SHIFT WEST AND DISSIPATE THROUGH TUESDAY. BERMUDA HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE EAST THROUGH MID WEEK. A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE IN THE WEEK AND STALL NORTH OF THE AREA NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM SUNDAY...WEAK BUT SCATTERED-TO-NUMEROUS SHOWERS AND THUNDERSTORMS CONTINUE THIS AFTN...WITH MORE WIDESPREAD ACTIVITY ANTICIPATED TONIGHT. HIGH PRESSURE OFFSHORE COMBINED WITH A MID-LEVEL TROUGH ALIGNED WEST OF THE AREA ARE WORKING TOGETHER TO INCREASE COLUMN MOISTURE TODAY...AND KEEP A CONVECTIVELY UNSTABLE ENVIRONMENT. AS EXPECTED...THE MAJORITY OF THE SHOWERS/TSTMS HAVE BEEN ACROSS THE WESTERN HALF OF THE CWA...AND THIS WILL CONTINUE INTO TONIGHT. THIS DOES NOT MEAN...HOWEVER...THAT EASTERN ZONES WILL BE DRY. A WEAKENING COASTAL TROUGH/SEA BREEZE FRONT WILL CONTINUE TO SPAWN SHOWERS WITH ISO TSTMS THROUGH EVE BEFORE LOSS OF HEATING CAUSES THIS TO FIZZLE OUT. THE CONVECTION SOUTH AND WEST OF THE AREA WILL CONTINUE AS IT IS BEING DRIVEN BY WEAK IMPULSES ALOFT ROTATING AROUND THE BASE OF THE LONGWAVE TROUGH. AT THE SAME TIME...DEEPENING SHORTWAVE EVIDENT ON WV IMAGERY DROPPING INTO THE ARKLATEX WILL SHARPEN THE OVERALL LONGWAVE PATTERN...CREATING AN OPEN GOM AND HELPING TO FURTHER INCREASE COLUMN MOISTURE. PWATS ARE EXPECTED TO RISE TO WELL ABOVE TWO INCHES BY MONDAY MORNING. THIS MOIST COLUMN WILL LIKELY ALLOW CONVECTION TO CONTINUE MUCH OF THE NIGHT...ESPECIALLY SINCE INSTABILITY WILL PERSIST WITHIN A RESIDUAL LAYER ABOVE THE NOCTURNAL STABLE PBL. WEAK IMPULSES ALOFT WILL BE ABLE TO TAP THIS OTHERWISE FAVORABLE ENVIRONMENT...AND EXPECT SHOWERS TO RE-DEVELOP AFTER A BRIEF LULL TONIGHT...AND BECOME MORE WIDESPREAD FROM SW TO NE TONIGHT. THIS IS ECHOED WELL BY HIGH RES HRRR WHICH HAS BEEN INITIALIZING PRETTY WELL TODAY. COOLING TONIGHT WILL BE LIMITED BY WIDESPREAD CLOUDS...INCREASING PRECIP COVERAGE...AND CONTINUED WAA ON SOUTHERLY WINDS. HAVE FORECAST LOWS ABOVE THE COOLEST GUIDANCE...WITH MID 70S EXPECTED AT THE BEACHES...AND LOWS AROUND 70 FAR WESTERN ZONES. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...IT COULD BE A WET DAY MONDAY...ESPECIALLY INLAND...WITH AN UPPER TROUGH OVER THE AREA AND AN OLD FRONT STALLED NEARBY. ADDITIONALLY...AND A S/W TROUGH WILL MOVE THROUGH DURING MONDAY. EXPECT TO SEE SCT TO NUMEROUS SHOWERS AND STORMS MONDAY INTO MONDAY EVENING...ESPECIALLY ALONG THE INTERSTATE 95 CORRIDOR. MAXES MONDAY SHOULD REACH THE MID 80S MOST AREAS WITH LOWS MONDAY NIGHT AROUND 70. THE INFLUENCE OF THE UPPER TROUGH WILL DIMINISH A LITTLE TUESDAY BUT THE OLD FRONT WILL BE CLOSER TO THE AREA AND THE ASSOCIATED TROUGH MAX BE MORE PRONOUNCED. THE WRF EVEN BRINGS A WEAK LOW PRESSURE WAVE INTO THE AREA TUESDAY. EXPECT SCATTERED SHOWERS AND STORMS AGAIN TUESDAY WITH THE MAXIMUM IN COVERAGE ASSOCIATED WITH DAYTIME HEATING. MAXIMUM SHOULD REACH THE MID TO UPPER 80S WITH MINS AGAIN AROUND 70. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 300 PM SUNDAY...A PIEDMONT TROUGH WILL BE SETUP TO THE WEST AT THE BEGINNING OF THE EXTENDED FORECAST PERIOD. A COLD FRONT WILL SHIFT SOUTHWESTWARD BUT IS EXPECTED TO STALL TO THE NORTH AND WEST ON FRIDAY. THE REGION WILL BE IN THE CLASSICAL SOUTHWEST FLOW WITH PRECIPITABLE WATERS ABOVE THE CLIMATOLOGICAL 75TH PERCENTILE FOR THE PERIOD. SCATTERED DIURNAL THUNDERSTORMS ARE EXPECTED WEDNESDAY INTO THURSDAY WITH AN INCREASE IN COVERAGE ON FRIDAY WITH THE APPROACHING FRONT AND BETTER UPPER LEVEL DYNAMICS. HEAVY RAIN IS POSSIBLE WITH THE STRONGER STORMS. MAXIMUM TEMPERATURES WILL RETURN INTO THE LOWER 90S WITH A FEW MIDDLE 90S INLAND ON WEDNESDAY AND THURSDAY. WITH INCREASED CLOUD COVER AND POSSIBLE CONVECTION EXPECT HIGHS ON FRIDAY TO BE IN THE UPPER 80S. AS THE FRONT REMAINS JUST TO THE NORTH ON SATURDAY AND SUNDAY MAXIMUM TEMPERATURES WILL RETURN INTO THE LOWER 90S. LOW TEMPERATURES ARE EXPECTED TO BE IN THE MIDDLE TO LOWER 70S THROUGH THE EXTENDED PERIOD. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... AS OF 18Z...FAIRLY ACTIVE CONVECTION EXPECTED THIS AFTERNOON WITH STRONG CAPE AND HIGH PRECIPITABLE WATER. SOME BRIEF DOWNPOURS ARE POSSIBLE...HOWEVER MOST SPOTS WILL EXPERIENCE PREDOMINATELY MVFR CONDITIONS IN THE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. SOUTHEAST WINDS ARE EXPECTED THIS AFTERNOON...WITH A FEW HIGHER GUSTS IN CONVECTION. LIGHT TO NEARLY CALM WINDS TONIGHT WITH POSSIBLE FOG/STRATUS AFTER 08Z...BEST CHANCE INLAND...AND ALTHOUGH A LULL IN PRECIP IS EXPECTED EARLY IN THE NIGHT...EXPECT SHOWERS TO RE-DEVELOP LATE...AND INTO MONDAY MORNING. MONDAY...LOOKS LIKE A RAINY DAY WITH POSSIBLE WIDESPREAD CONVECTION...LIKELY ONGOING EARLY IN THE DAY AND CONTINUING THROUGH THE END OF THE VALID PERIOD. EXTENDED OUTLOOK...CHANCE OF SHOWERS/TSTMS THROUGH THE EXTENDED. VFR WILL BE PREDOMINANT...BUT BRIEF PERIODS OF MVFR CIGS/VSBYS ARE POSSIBLE IN STORMS. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM SUNDAY...RATHER NONDESCRIPT PRESSURE PATTERN HAS KEPT WINDS LIGHT THUS FAR TODAY...WITH 10 KTS OR LESS SE WINDS OBSERVED AT THE LOCAL BUOYS. THESE WINDS WILL REMAIN CONSISTENT THROUGH TONIGHT. THE LACK OF SIGNIFICANT WIND HAS ALLOWED A 9 SEC SE SWELL TO BECOME PREDOMINANT IN THE WAVE SPECTRUM...SO ALTHOUGH A WEAK S/SE WIND CHOP EXISTS...SIGNIFICANT SEAS ARE 2-3 FT WITH AN 8 SEC PERIOD. THIS IS EXPECTED TO REMAIN PRETTY UNIFORM INTO MONDAY MORNING. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...EXPECT LIGHT AND VARIABLE ONSHORE WINDS THROUGH MUCH OF THE PERIOD AS A FRONT LINGERS OFFSHORE. WINDS MAY BECOME SW TUESDAY NIGHT AS THE FRONT MOVES ASHORE. SEAS WILL BE 3 FT OR LESS THROUGH THE PERIOD. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 300 PM SUNDAY...AS A PIEDMONT TROUGH DEVELOPS WINDS WILL SHIFT FROM THE SOUTH TO THE SOUTHWEST AND A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY AND FRIDAY BEFORE STALLING OUT TO THE NORTHWEST. THE WINDS SPEEDS ARE EXPECTED TO START OUT AROUND 15 KNOTS BUTS AS A COLD FRONT APPROACH THE PRESSURE GRADIENT WILL TIGHTEN LATE WEDNESDAY AND THE WINDS WILL INCREASE TO 20 KNOTS ESPECIALLY AT 20 MILES OFF THE COAST. SEAS ARE EXPECTED TO START THE PERIOD OUT AROUND 2 TO 3 FEET AND WITH INCREASE WINDS WILL INCREASE TO 3 TO 5 FEET BY THURSDAY AND THURSDAY NIGHT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...HIGH RIP CURRENT RISK UNTIL 10 PM EDT THIS EVENING FOR NCZ106- 108. MARINE...NONE. && $$ SYNOPSIS..31 NEAR TERM...WEISS SHORT TERM...31 LONG TERM...DRH AVIATION...DL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
951 PM CDT MON JUL 21 2014 .UPDATE... ISSUED AT 949 PM CDT MON JUL 21 2014 ADJUSTED POPS TO CURRENT RADAR IMAGERY AND TRIMMED EASTERN ND OUT OF WATCH. UPDATE ISSUED AT 640 PM CDT MON JUL 21 2014 ADJUSTED EARLY EVENING POPS HIGHLIGHTING MAIN CONVECTION OVER THE FAR NW FA. MAIN THREAT WILL BE WIND AND HEAVY RAIN. EXPECT CONVECTION TO GRADUALLY EXPAND AS MAIN COMPLEX MOVES IN FROM THE WEST WITH HEAVY RAIN/DAMAGING WINDS MAIN THREAT. NO OTHER CHANGES. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 315 PM CDT MON JUL 21 2014 CONVECTION TIMING AND SEVERITY WILL BE THE MAIN FORECAST HEADACHE FOR THE SHORT TERM. STORMS HAVE DEVELOPED OVER WESTERN ND A FEW HOURS SOONER THAN ORIGINALLY THOUGHT. A LITTLE BIT OF ACTIVITY HAS FIRED NORTH OF THE BOUNDARY IN THE UPPER DEVILS LAKE BASIN...BUT CONVECTION IN THAT AREA HAS BEEN SUB SEVERE SO FAR. THE STRONGEST ACTIVITY HAS BEEN IN THE WESTERN PART OF THE STATE WITH THE MAIN SHORTWAVE...BUT OUR NORTHWESTERN COUNTIES WILL BE UNDER THE GUN IN THE NEXT FEW HOURS AS THE SHORTWAVE MOVES CLOSER AND THE ATMOSPHERE CONTINUES TO DESTABILIZE WITH ML CAPE ABOVE 3000 J/KG. WITH A SFC BOUNDARY HANGING AROUND IN THE AREA...THERE COULD BE ENOUGH LOW LEVEL HELICITY TO GET STORMS TURNING IF THEY ARE ISOLATED ENOUGH. THUS...TORNADO WATCH FOR OUR NORTHWEST EARLY ON IN THIS EVENT. LATER ON TONIGHT...THE THUNDERSTORMS ARE EXPECTED TO EVOLVE INTO A COMPLEX MOVING ACROSS THE CWA. WITH PLENTY OF MOISTURE FEEDING INTO THE COMPLEX AS DEW POINTS RISE INTO THE 70S...AND THE HIGHLY UNSTABLE AIR MASS...STORMS SHOULD MAINTAIN THEMSELVES AS THEY MOVE INTO THE RED RIVER VALLEY AND THEN INTO MN. BULK SHEAR VALUES ARE AROUND 40 TO 50 KTS ALTHOUGH THE LOW LEVEL SHEAR IS NOT NEARLY AS STRONG AS NEAR THE SFC BOUNDARY. MODEL SOLUTIONS CONTINUE TO POINT TO A BOW ECHO TYPE PATTERN...AND THE HRRR HAS BEEN CONSISTENT ON SHOWING HIGH WIND GUSTS ALONG WITH THE STORMS. SIGNS CONTINUE TO POINT TO A MCS ARRIVING IN THE VALLEY THIS EVENING AND MOVING EASTWARD INTO MN AFTER MIDNIGHT. DERECHO COMPOSITE ON THE SPC MESO PAGE IS IN THE 6 TO 8 RANGE...SO WILL KEEP THE DAMAGING WIND TAGS IN THE GRIDS FOR THIS EVENING. THE OTHER THREAT WILL BE HEAVY RAINFALL. THE MODELS CONTINUE TO CRANK OUT BULLSEYES OF OVER 2 INCHES IN A VERY SHORT TIME PERIOD. WITH PWAT VALUES UP TO 1.5 INCHES AND 850MB MOISTURE TRANSPORT CONTINUING TO PUSH MORE MOISTURE INTO OUR COUNTIES...HEAVY RAINFALL CONTINUES TO SEEM REASONABLE. THE ISSUE WILL BE WHERE IT FALL AND HOW LONG THE PRECIP WILL LAST. MANY OF THE SHORT RANGE MODELS HAVE BEEN TRENDING FURTHER NORTH WITH THE TRACK OF THE CONVECTION...WHICH WOULD TAKE IT ALONG THE NORTHERN EDGE OF THE MOST WARM AND MOIST AIR. THE FLY IN THE OINTMENT WILL BE THE MOVEMENT OF THE STORMS AS THE COMPLEX ACCELERATES ACROSS THE CWA. SINCE THERE HAS BEEN FAIRLY DRY WEATHER THE PAST FEW WEEKS OVER THE VALLEY...WILL HOLD OFF ON ANY FLOOD WATCHES FOR NOW BUT HAVE TO KEEP AN EYE ON THE STORMS AS THEY APPROACH THE MN LAKES COUNTRY LATER TONIGHT. THERE COULD BE SOME LINGERING SHOWERS AND STORMS IN THE EASTERN COUNTIES TOWARDS TOMORROW MORNING...BUT THERE SHOULD BE A DRYING TREND AS A COLD FRONT MOVES IN AND HIGH PRESSURE ARRIVES. TUESDAY WILL BE QUITE A BIT COOLER THAN TODAY...WITH HIGHS IN THE 70S TO LOW 80S AND DEW POINTS BACK DOWN INTO THE 50S. SFC HIGH PRESSURE WILL CONTINUE INTO TUESDAY NIGHT AND KEEP LOWS MUCH COOLER THAN THEY HAVE BEEN THE PAST FEW NIGHTS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 315 PM CDT MON JUL 21 2014 WEDNESDAY TO MONDAY...MODELS IN FAIR AGREEMENT WITH THE EXTENDED TIME FRAME. OVERALL TEMPS REGIME WILL BE NORMAL TO BELOW NORMAL TEMPS WITH DRY WEATHER FEATURED MOST DAYS AS SFC HIGH PRESSURE COMBINED WITH PREDOMINANTLY NW FLOW ALOFT PERSISTS. THE EXCEPTION IS THURSDAY NIGHT INTO FRIDAY AND SUNDAY WITH CHC THUNDERSTORMS AS RIDGING SHUNTS BACK TO THE WEST WITH POTENT SHORT WAVE RIDING OVER THE TOP BRINGING INSTABILITY AND FORCING TO THE NORTHERN PLAINS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 640 PM CDT MON JUL 21 2014 BEST ATTEMPT AT TIMING CONVECTION PROPAGATING EASTWARD ACROSS THE FORECAST AREA. MAIN HAZARD WILL BE DAMAGING WINDS AND VERY HEAVY RAIN. WILL LIKELY SEE MVFR/IFR CIGS/VSBY IN STRONGER CELLS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...VOELKER SHORT TERM...JR LONG TERM...JK AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
645 PM CDT MON JUL 21 2014 .UPDATE... ISSUED AT 640 PM CDT MON JUL 21 2014 ADJUSTED EARLY EVENING POPS HIGHLIGHTING MAIN CONVECTION OVER THE FAR NW FA. MAIN THREAT WILL BE WIND AND HEAVY RAIN. EXPECT CONVECTION TO GRADUALLY EXPAND AS MAIN COMPLEX MOVES IN FROM THE WEST WITH HEAVY RAIN/DAMAGING WINDS MAIN THREAT. NO OTHER CHANGES. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 315 PM CDT MON JUL 21 2014 CONVECTION TIMING AND SEVERITY WILL BE THE MAIN FORECAST HEADACHE FOR THE SHORT TERM. STORMS HAVE DEVELOPED OVER WESTERN ND A FEW HOURS SOONER THAN ORIGINALLY THOUGHT. A LITTLE BIT OF ACTIVITY HAS FIRED NORTH OF THE BOUNDARY IN THE UPPER DEVILS LAKE BASIN...BUT CONVECTION IN THAT AREA HAS BEEN SUB SEVERE SO FAR. THE STRONGEST ACTIVITY HAS BEEN IN THE WESTERN PART OF THE STATE WITH THE MAIN SHORTWAVE...BUT OUR NORTHWESTERN COUNTIES WILL BE UNDER THE GUN IN THE NEXT FEW HOURS AS THE SHORTWAVE MOVES CLOSER AND THE ATMOSPHERE CONTINUES TO DESTABILIZE WITH ML CAPE ABOVE 3000 J/KG. WITH A SFC BOUNDARY HANGING AROUND IN THE AREA...THERE COULD BE ENOUGH LOW LEVEL HELICITY TO GET STORMS TURNING IF THEY ARE ISOLATED ENOUGH. THUS...TORNADO WATCH FOR OUR NORTHWEST EARLY ON IN THIS EVENT. LATER ON TONIGHT...THE THUNDERSTORMS ARE EXPECTED TO EVOLVE INTO A COMPLEX MOVING ACROSS THE CWA. WITH PLENTY OF MOISTURE FEEDING INTO THE COMPLEX AS DEW POINTS RISE INTO THE 70S...AND THE HIGHLY UNSTABLE AIR MASS...STORMS SHOULD MAINTAIN THEMSELVES AS THEY MOVE INTO THE RED RIVER VALLEY AND THEN INTO MN. BULK SHEAR VALUES ARE AROUND 40 TO 50 KTS ALTHOUGH THE LOW LEVEL SHEAR IS NOT NEARLY AS STRONG AS NEAR THE SFC BOUNDARY. MODEL SOLUTIONS CONTINUE TO POINT TO A BOW ECHO TYPE PATTERN...AND THE HRRR HAS BEEN CONSISTENT ON SHOWING HIGH WIND GUSTS ALONG WITH THE STORMS. SIGNS CONTINUE TO POINT TO A MCS ARRIVING IN THE VALLEY THIS EVENING AND MOVING EASTWARD INTO MN AFTER MIDNIGHT. DERECHO COMPOSITE ON THE SPC MESO PAGE IS IN THE 6 TO 8 RANGE...SO WILL KEEP THE DAMAGING WIND TAGS IN THE GRIDS FOR THIS EVENING. THE OTHER THREAT WILL BE HEAVY RAINFALL. THE MODELS CONTINUE TO CRANK OUT BULLSEYES OF OVER 2 INCHES IN A VERY SHORT TIME PERIOD. WITH PWAT VALUES UP TO 1.5 INCHES AND 850MB MOISTURE TRANSPORT CONTINUING TO PUSH MORE MOISTURE INTO OUR COUNTIES...HEAVY RAINFALL CONTINUES TO SEEM REASONABLE. THE ISSUE WILL BE WHERE IT FALL AND HOW LONG THE PRECIP WILL LAST. MANY OF THE SHORT RANGE MODELS HAVE BEEN TRENDING FURTHER NORTH WITH THE TRACK OF THE CONVECTION...WHICH WOULD TAKE IT ALONG THE NORTHERN EDGE OF THE MOST WARM AND MOIST AIR. THE FLY IN THE OINTMENT WILL BE THE MOVEMENT OF THE STORMS AS THE COMPLEX ACCELERATES ACROSS THE CWA. SINCE THERE HAS BEEN FAIRLY DRY WEATHER THE PAST FEW WEEKS OVER THE VALLEY...WILL HOLD OFF ON ANY FLOOD WATCHES FOR NOW BUT HAVE TO KEEP AN EYE ON THE STORMS AS THEY APPROACH THE MN LAKES COUNTRY LATER TONIGHT. THERE COULD BE SOME LINGERING SHOWERS AND STORMS IN THE EASTERN COUNTIES TOWARDS TOMORROW MORNING...BUT THERE SHOULD BE A DRYING TREND AS A COLD FRONT MOVES IN AND HIGH PRESSURE ARRIVES. TUESDAY WILL BE QUITE A BIT COOLER THAN TODAY...WITH HIGHS IN THE 70S TO LOW 80S AND DEW POINTS BACK DOWN INTO THE 50S. SFC HIGH PRESSURE WILL CONTINUE INTO TUESDAY NIGHT AND KEEP LOWS MUCH COOLER THAN THEY HAVE BEEN THE PAST FEW NIGHTS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 315 PM CDT MON JUL 21 2014 WEDNESDAY TO MONDAY...MODELS IN FAIR AGREEMENT WITH THE EXTENDED TIME FRAME. OVERALL TEMPS REGIME WILL BE NORMAL TO BELOW NORMAL TEMPS WITH DRY WEATHER FEATURED MOST DAYS AS SFC HIGH PRESSURE COMBINED WITH PREDOMINANTLY NW FLOW ALOFT PERSISTS. THE EXCEPTION IS THURSDAY NIGHT INTO FRIDAY AND SUNDAY WITH CHC THUNDERSTORMS AS RIDGING SHUNTS BACK TO THE WEST WITH POTENT SHORT WAVE RIDING OVER THE TOP BRINGING INSTABILITY AND FORCING TO THE NORTHERN PLAINS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 640 PM CDT MON JUL 21 2014 BEST ATTEMPT AT TIMING CONVECTION PROPAGATING EASTWARD ACROSS THE FORECAST AREA. MAIN HAZARD WILL BE DAMAGING WINDS AND VERY HEAVY RAIN. WILL LIKELY SEE MVFR/IFR CIGS/VSBY IN STRONGER CELLS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NDZ039-049-052-053. MN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MNZ003-029>032-040. && $$ UPDATE...VOELKER SHORT TERM...JR LONG TERM...JK AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1053 AM EDT SUN JUL 20 2014 .SYNOPSIS... UPPER LEVEL TROUGH CROSSING TODAY. WEAK SLUGGISH FLOW INTO TUESDAY...WITH HOTTER TEMPERATURES AND MAINLY DIURNAL CONVECTION. COLD FRONT INITIALLY TIMED TO PASS ON THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... 1045 AM UPDATE... ANOTHER DAY...ANOTHER S/W DISTURBANCE TO FOLLOW. THIS ONE NOT AS POTENT AS YESTERDAY THOUGH. AREA OF -SHRA MOVING FROM TUG FORK AND TRI STATE AND INTO C LOWLANDS NEXT FEW HRS. BASED ON LAST FEW RUNS OF HRRR HAVE INCREASED POPS GOING DETERMINISTIC TO FOLLOW THIS THRU UP TO ABOUT I64 CORRIDOR WITH LKLY POPS BEFORE IT FADES. WITH SOME HEATING AND INITIAL SUN OVER THE MOUNTAINS...THINK THIS SHOULD REDEVELOP AND BECOME MORE STOUT LATER THIS AFTERNOON AS IT SLIDES INTO THIS AREA WITH SOME INSTABILITY NOTED ON THE MODELS. ANY MID LVL CAP SHOULD BE NIXED AS THIS FEATURE CROSSES. ALSO SOME CONVERGENCE NEAR THE SURFACE FROM SSE FLOW SHOULD HELP AS WELL ACROSS THE HIGH TERRAIN. THUS...HAVE EXPANDED LKLY POPS ACROSS A GOOD PORTIONS OF THE C AND ESPECIALLY THE N MOUNTAINS FOR THIS AFTERNOON WITH MAINLY SCHC ELSEWHERE AND ROLLING WITH COVERAGE WORDING IN THE GRIDS. ALSO HAVE THUNDER IN...GIVEN BUILDING INSTABILITY PER MODELS. PREVIOUS DISCUSSION BELOW... STILL DEALING WITH 500MB TROUGH SLIDING THROUGH. MODELS SHOWING SEVERAL RIPPLES IN THE PATTERN THAT WILL CONTINUE ISOLATED TO SCATTERED SHOWERS TODAY. AN ISOLATED RUMBLE OF THUNDER POSSIBLE THIS AFTERNOON AS WELL. MODELS FAVORING THE COAL FIELDS AND SOUTHERN MOUNTAINS FOR HIGHEST POPS...CORRESPONDING TO MOST PRONOUNCED VORT LOBE. HAVE POPS LINGERING IN THE WV MOUNTAINS INTO TONIGHT. WITH A GOOD DEAL OF CLOUDS STILL AROUND TODAY...AND BASED ON HIGH TEMPS STAYING BELOW GUIDANCE YESTERDAY...LOWERED FORECAST HIGHS FOR TODAY A COUPLE DEGREES. ONLY MINIMAL CHANGES MADE TO OVERNIGHT LOWS BY USING A BIAS-CORRECTED CONSENSUS BLEND. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... FLOW AT 700 MBS AOB 10 KNOTS MONDAY AND TUESDAY. WITH A WEAK 925 MB FLOW STILL FROM THE SOUTHEAST. FORECAST SOUNDINGS STILL SHOW THIN CAPE DEVELOPING DURING THE 18Z TO 00Z TIME FRAME. WILL CONTINUE TO MENTION MOSTLY AFTERNOON AND EVENING CONVECTION OVER THE MOUNTAIN COUNTIES. YET...LATE IN THE DAY...COULD NOT RULE OUT AN ISOLATED STORM COMING OFF THE MOUNTAINS INTO THE WESTERN SLOPES. THE DEEPER MOISTURE OVER THE SOUTHEASTERN STATES MAY ACTUALLY TRY TO CREEP BACK NORTH TOWARD THE WV/VA BORDER AREA OVERNIGHT TUESDAY NIGHT INTO WEDNESDAY MORNING. SO LEFT A 20 POP FOR THE PREDAWN HOURS WEDNESDAY MOSTLY S OF BECKLEY. ON WEDNESDAY...TRIED TO HOLD THE HTS-CRW-CKB AREA POP AOB 14 PCT LONGER. HAVE CHANCE POPS OVER THE SOUTHERN MOUNTAINS WITH THE SYSTEM IN THE SE STATES...AND THEN CHANCE POPS INCREASING ACROSS SOUTHEAST OHIO DURING THE AFTERNOON FROM THE PREFRONTAL MID LEVEL DISTURBANCE IN THE WESTERLIES MOVING THROUGH THE LOWER GREAT LAKES. WARMEST TEMPERATURES TUESDAY AFTERNOON AND WEDNESDAY AFTERNOON. SOME WEAK DOWNSLOPING TUESDAY AFTERNOON FOR THE I-79 CORRIDOR...WHILE WARMEST 850 MB TEMPERATURES LIKELY ON WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... ON WEDNESDAY EVENING AND THURSDAY MORNING...A MORE ROBUST FRONT ARRIVES AS IT TRAILS OFF OF A RATHER DEEP SYNOPTIC LOW THAT SWINGS OFF OF THE GREAT LAKES. THE SYSTEM MAY ARRIVE IN THE FORM OF A DECAYING MCS...BUT WILL HAVE TO KEEP AN EYE ON IT. INSTABILITY IS GOOD IN FRONT OF IT WITH SOME MINOR UPPER LEVEL SUPPORT WITH NW FLOW AND A DECENT VORT MAX. BULK SHEAR IN THE 30 KT RANGE LOOKS GOOD TOO. ACCORDINGLY...BOOSTED POPS AND SPED UP TIMING A TAD. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... MIXED BAG ACROSS FORECAST AREA EARLY THIS MORNING. HAVE DENSE FOG FLOATING AROUND...PLUS SOME SHOWERS ACROSS THE SOUTH AND GRADUALLY DRIFTING NORTH. WITH A COUPLE RIPPLES AT 500MB CANNOT RULE OUT AN ISOLATED SHOWER TODAY...AND POSSIBLY A RUMBLE OF THUNDER THIS AFTERNOON...BUT CONFIDENCE TO LOW IN WHEN AND WHERE TO PUT IN TAF AT THIS POINT. OUTSIDE OF SHOWERS...THINGS SHOULD IMPROVE TO VFR ACROSS THE LOWLANDS THROUGH THE DAY. LOWER CIGS MAY HANG IN THE MOUNTAINS WITH SE FLOW. ANTICIPATE MORE SCATTERED CLOUDS TONIGHT...SO HAVE RIVER VALLEY FOG FORMING AFTER AROUND 06Z TONIGHT IN TYPICAL LOCATIONS. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: AMENDMENTS MAY BE NEEDED AS SHOWERS PROGRESS THROUGH THE DAY. FOG DENSITY AND TIMING MAY VARY TONIGHT. 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 M M M M M M M M M M M H HTS CONSISTENCY M M M M M M M M M H H H BKW CONSISTENCY H H M M H M M H M M M M EKN CONSISTENCY M H M H H H H H H H H H PKB CONSISTENCY H M M M H M M M M M M H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z MONDAY... NO WIDESPREAD IFR CONDITIONS FORECAST. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/MZ NEAR TERM...MZ/30 SHORT TERM...KTB LONG TERM...JW AVIATION...MZ
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1033 AM EDT SUN JUL 20 2014 .SYNOPSIS... A WEAKENING UPPER TROUGH WILL LIFT TO THE NORTHEAST TODAY AD MONDAY. A COLD FRONT WILL LIKELY SAG SOUTHWARD INTO THE REGION BY LATE WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM UPDATE... SATELLITE SHOWS VARIABLE AMOUNTS OF CLOUDINESS OVER THE AREA WITH A FEW VERY LIGHT RETURNS...SPRINKLES...INDICATED ON RADAR. PRETTY MUCH JUST A CLOUDY AND UNSEASONABLY COOL MORNING IN PROGRESS BUT OTHERWISE UNEVENTFUL. UPPER HEIGHTS ARE RISING AS THE TROUGH OVER THE LOWER LAKES CONTINUES TO LIFT OUT INTO SERN CANADA. I GENERALLY DOWNPLAYED THE CHANCES FOR PRECIP TODAY...AND MAY DOWNPLAY FURTHER AS MORE DATA COMES IN. OPERATIONAL GUIDANCE AND ENSEMBLES JUST DO NOT GENERATE ENOUGH INSTABILITY TO GIVE ME MUCH CONFIDENCE THAT SHOWERS/THUNDER WILL EVENTUALLY BECOME VERY WIDESPREAD LATER TODAY. THINKING IS THAT THE BEST CHANCE FOR SOMETHING TO POP UP WILL BE OVER WESTERN AREAS. UNLIKE YESTERDAY WHEN THE HRRR WAS THE LONE HOLD-OUT IN DRAGGING RAIN THROUGH THE LOWERS SUSQ AND PROVED TO BE RIGHT...ALL MODELS AGREE TODAY IN JUST SOME SCATTERED ACTIVITY THIS AFTERNOON...KEEPING IT OVER THE WEST. MORE CLOUDS THAN SUN WILL LIMIT HIGH TEMPS TO SOMEWHERE BETWEEN 75 AND 80...WHICH WILL BE SEVERAL DEGREES COOLER THAN NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... CONDITIONS QUIET DOWN THIS EVENING AS DEEP LAYER STABILITY INCREASES...WITH MID LEVEL TEMPS WARMING SLIGHTLY. A FEW ISOLATED SHOWERS CAN/T BE RULED OUT...ESPECIALLY ACROSS THE CENTRAL MTNS AND ALONG THE ALLEGHENY FRONT. LOW TEMPS TONIGHT WILL ONCE AGAIN VARY FROM THE MID TO UPPER 50S ACROSS THE NRN AND WRN MTNS...TO THE LOWER 60S THROUGHOUT THE SCENT ZONES AND SUSQ VALLEY. RISING HEIGHTS AND MID LEVEL TEMPS /BUT STILL WEAK TROUGHINESS AT THE SFC AND ALOFT ACROSS THE WESTERN HALF OF PENN/ WILL LEAD TO ANOTHER DAY OF MAINLY ISOLATED AFTERNOON SHRA/TSRA. TEMPS MONDAY AFTERNOON WILL REACH THE U70S ACROSS THE MTNS...AROUND 80F IN THE CENTRAL VALLEYS...AND LOWER 80S THROUGHOUT THE SUSQ RIVER VALLEY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... SURFACE HIGH PRESSURE AXIS TO OUR EAST WILL KEEP GENERALLY FAIR WEATHER ACROSS PENNSYLVANIA EARLY IN THE WEEK AS THE UPPER FLOW REMAINS WEAKLY TROFFY TO ZONAL WITH THE STRONGEST FLOW LOCATED NORTH OF U.S. BORDER. LOW LEVEL MOISTURE WILL ATTEMPT TO CREEP BACK INTO THE REGION ON WEAK RETURN FLOW...BUT DEEPEST MOISTURE WILL REMAIN FARTHER WEST OVER OHIO VALLEY. KEPT MENTION OF ISO/SCT TSTMS MON-EARLY WED /MAINLY ACROSS THE WEST/. A WARMING TREND BEGINNING ON MONDAY...WILL CONTINUE RIGHT THROUGH WED...WHEN TEMPS ARE EXPECTED REACH THEIR PEEK FOR THE WEAK IN THE IN THE UPPER 80S TO AROUND 90F IN THE SUSQ VALLEY...AND GENERALLY IN THE MID 80S ELSEWHERE. A LARGE RIDGE BUILDS OVER THE CENTRAL ROCKIES AND FOUR CORNERS REGION BY MIDDLE OF THE WEEK...ALLOWING WEAK WAVES IN THE WESTERLY FLOW ALONG THE CANADIAN/U.S. BORDER TO CARVE OUT A TROUGH OVER THE GREAT LAKES BY MIDWEEK. INCREASING SOUTHERLY FLOW BETWEEN THIS TROUGH AND AN UPPER RIDGE PARKED OFF THE SE COAST WILL DRAW INCREASINGLY WARM AND HUMID AIR INTO THE AREA. TEMPS AND HUMIDITY WILL PEAK WED-THU AHEAD OF A WAVE THAT DROPS INTO OHIO VALLEY MIDWEEK...AND THEN SLIDES THROUGH ON A COOL FRONT LATE WEEK. DAILY PRECIP CHANCES INCREASE WED...AND PEAK ON THU...BEFORE DRIER AND MORE STABLE AIR WORKS IN FOR NEXT WEEKEND. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... A WEAKENING TROUGH ALOFT WILL LIFT POLEWARD ACROSS THE NORTHEAST TODAY. LOCAL MVFR CONDITIONS WILL IMPROVE TO VFR BY MID DAY...WITH VFR PREVAILING THRU THE AFTERNOON. AN ISOLATED SHOWER OR THUNDERSTORM WILL BE POSSIBLE...MAINLY ALONG AND WEST OF THE ALLEGHENY MTNS INTO THE EVENING. LOOK FOR PATCHY FOG AND LOW CLOUDS TO REDEVELOP TONIGHT AS SKIES GRADUALLY CLEAR OUT AND WINDS GO LIGHT AND VARIABLE. OUTLOOK... MON-TUE...MAINLY VFR. PATCHY A.M MVFR FOG/BR. WDLY SCT SHRA/TSRA. WED-THU...COLD FROPA LATER WED-WED NGT SHOULD BRING A GREATER CVRG OF SHRA/TSRA DURING THE MID-WEEK PERIOD. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...LA CORTE/LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/GARTNER AVIATION...LA CORTE/STEINBUGL
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
941 PM CDT MON JUL 21 2014 .UPDATE... THE PREVIOUS FORECAST IS IN GOOD SHAPE. HAVE JUST MADE SOME CHANGES TO THE HOURLY GRIDS FOR ON-GOING TRENDS. 58 && .AVIATION... /ISSUED 704 PM CDT MON JUL 21 2014/ /00Z TAFS/ CONCERNS...STRATUS POTENTIAL. AS THE SUN SETS...THE AFTERNOON CU FIELD WILL GIVE WAY TO CLEAR SKIES...WHICH SHOULD PREVAIL MUCH OF THE NIGHT. FEW OR SCATTERED CLOUDS MAY DEVELOP NEAR THE TOP OF THE NOCTURNAL BOUNDARY LAYER (1000-2000FT AGL) NEAR SUNRISE TUESDAY...LINGERING THROUGH MID- MORNING...BUT MVFR CEILINGS LOOK UNLIKELY. SYNOPTIC-SCALE MOS GUIDANCE WAS CONFOUNDED BY DEW POINTS IN THE MID-70S DURING JULY...BUT THE 00Z NAM SUNDAY EVENING DID KEY ON THE LIKELIHOOD FOR LOW CEILINGS MONDAY MORNING. DESPITE CONSIDERABLE MOISTURE REMAINING IN PLACE...THE CURRENT MOS OUTPUT IS VFR FOR TUESDAY MORNING. THE LATEST RAP PERFECT PROGS SUGGEST THE BEST POTENTIAL FOR A THIN LAYER OF TROPICAL STRATUS WOULD BE EAST OF THE I-35 CORRIDOR. IT IS IMPORTANT TO NOTE THAT THIS POTENTIAL STRATUS SCENARIO DEPENDS ON THE ABILITY OF THE LAYER TO DEVELOP IN THE VICINITY OF OUR TAF SITES...NOT ON THE ADVECTION OF UPSTREAM STRATUS. SURFACE RIDGING OVER THE GULF SHOULD VEER THE LOW-LEVEL WINDS UPSTREAM...EFFECTIVELY CLOSING OFF THE GULF FROM ADDITIONAL MOIST ADVECTION OVERNIGHT. BUT OUR BOUNDARY LAYER MOISTURE IS ALREADY IN PLACE AND...WITH NEGLIGIBLE ADVECTION...IS LIKELY TO REMAIN UNCHANGED BY DAYBREAK TUESDAY. WILL CONTINUE TO MONITOR MESOSCALE OUTPUT THIS EVENING...BUT DO NOT ANTICIPATE NEEDING TO INTRODUCE CEILINGS WITH THE 03Z AMENDMENTS OR 06Z ROUTINE TAFS. 25 && .PREV DISCUSSION... /ISSUED 311 PM CDT MON JUL 21 2014/ SUMMER HEAT HAS QUICKLY RETURNED TO NORTH TEXAS TODAY WITH HOT AND HUMID CONDITIONS AREA-WIDE. TEMPERATURES IN THE 90S COMBINED WITH DEWPOINTS IN THE LOWER TO MIDDLE 70S HAVE CREATED HEAT INDICES IN THE 100-105 RANGE IN MANY LOCATIONS THIS AFTERNOON. ABOVE-NORMAL TEMPERATURES CAN BE EXPECTED FOR THE REST OF THE WEEK DUE MAINLY TO THE STRENGTHENING OF A MID AND UPPER LEVEL RIDGE OVER MUCH OF THE REGION. THE RIDGE AXIS IS CENTERED OVER COLORADO AND NEW MEXICO BUT STRETCHES EASTWARD ACROSS THE SOUTHERN PLAINS AND NORTH TEXAS...WITH LITTLE OVERALL CHANGE IN POSITION EXPECTED THIS WEEK. EAST OF THE RIDGE...A WEAK UPPER LOW CAN BE SEEN ON SATELLITE GENERATING CONVECTION OVER THE SOUTHEASTERN STATES. THIS LOW WILL SLOWLY MOVE WEST OVER THE NEXT COUPLE OF DAYS. NORTH TEXAS WILL RESIDE IN BETWEEN THE RIDGE TO THE WEST AND THE LOW TO THE EAST...WHICH WILL GENERATE NORTHEAST FLOW ALOFT THROUGH THURSDAY. A SUBTLE SHORTWAVE IS STILL PROGGED TO ROTATE SOUTHWEST ACROSS THE ARKLATEX REGION WEDNESDAY NIGHT....BRINGING WITH IT ENOUGH MOISTURE AND LIFT TO PRODUCE SCATTERED CONVECTION OVER NORTHEAST PORTIONS OF NORTH TEXAS. THE BEST CHANCES FOR SHOWERS AND STORMS WILL OCCUR NEAR PARIS...WHERE WE WILL GO AHEAD AND INCLUDE CHANCE POPS WEDNESDAY NIGHT. SLIGHT CHANCE POPS WILL BE INCLUDED IN AREAS SOUTHWEST OF LAMAR COUNTY INCLUDING DALLAS/FORT WORTH AND SURROUNDING LOCALES. THERE IS A CHANCE THAT THUNDERSTORMS WILL BECOME SOMEWHAT ORGANIZED AS THEY APPROACH FROM THE NORTHEAST LATE WEDNESDAY...PERHAPS FORMING INTO A SOUTHWEST MOVING MCS. IF THIS BEGINS TO APPEAR MORE LIKELY IN FUTURE MODEL DATA...HIGHER POPS MAY BE NEEDED FOR THE NORTHEASTERN THIRD OF THE REGION. THE NORTHEAST FLOW REGIME WILL ALLOW A WEAK FRONT TO SAG SOUTH ACROSS THE RED RIVER...BECOMING STATIONARY NORTH OF I-20 ON THURSDAY. THIS BOUNDARY COULD PROVIDE FOCUS FOR ISOLATED STORMS... AND WE WILL CONTINUE WITH 20 POPS OVER THE EASTERN HALF OF THE REGION THURSDAY. WESTERN COUNTIES WILL MOST LIKELY BE TOO HEAVILY IMPACTED BY SUBSIDENCE FROM THE CO/NM RIDGE FOR THE INCLUSION OF POPS. THE HIGH PRESSURE RIDGE WILL EXPAND LONGITUDINALLY LATE THIS WEEK THROUGH THE WEEKEND...REACHING AS FAR EAST AS THE TENNESSEE VALLEY FRIDAY. HOT AND RAIN-FREE WEATHER IS EXPECTED AS A RESULT ACROSS A LARGE PORTION OF TEXAS. THE MAIN WEATHER CONCERN WILL BE THE DAYTIME TEMPERATURES THIS WEEKEND...WITH CURRENT APPARENT TEMPERATURE GRIDS PRODUCING HEAT INDICES IN EXCESS OF 105 DURING THE AFTERNOON HOURS FRIDAY AND SATURDAY. WE WILL MONITOR OUR FORECAST TEMPERATURE/DEWPOINT TRENDS AS THE WEEKEND APPROACHES...AND MAY HAVE TO CONSIDER A HEAT ADVISORY IF IT APPEARS THAT THESE CONDITIONS WILL BECOME FAIRLY WIDESPREAD. THERE MAY BE SOME RELIEF IN SIGHT EARLY NEXT WEEK...AS MID RANGE MODELS CONTINUE TO INDICATE A DEEPENING UPPER TROUGH OVER THE EASTERN HALF OF THE NATION WHILE THE UPPER RIDGE RETROGRADES WEST. THIS MAY BRING SOME COOLER WEATHER ALONG WITH INCREASED RAIN CHANCES AS WE MOVE THROUGH NEXT WEEK. 30 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 77 98 78 99 78 / 0 5 5 10 20 WACO, TX 74 98 74 99 73 / 5 5 5 5 10 PARIS, TX 70 95 72 96 75 / 0 5 5 20 30 DENTON, TX 73 97 74 98 75 / 0 5 5 10 20 MCKINNEY, TX 72 98 73 99 74 / 0 5 5 10 20 DALLAS, TX 78 98 79 99 78 / 0 5 5 10 20 TERRELL, TX 75 98 75 99 75 / 0 5 5 10 20 CORSICANA, TX 75 97 75 98 75 / 5 5 5 10 20 TEMPLE, TX 74 98 73 99 73 / 5 5 5 5 10 MINERAL WELLS, TX 72 99 73 100 73 / 0 5 5 5 20 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 25/58
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
704 PM CDT MON JUL 21 2014 .AVIATION... /00Z TAFS/ CONCERNS...STRATUS POTENTIAL. AS THE SUN SETS...THE AFTERNOON CU FIELD WILL GIVE WAY TO CLEAR SKIES...WHICH SHOULD PREVAIL MUCH OF THE NIGHT. FEW OR SCATTERED CLOUDS MAY DEVELOP NEAR THE TOP OF THE NOCTURNAL BOUNDARY LAYER (1000-2000FT AGL) NEAR SUNRISE TUESDAY...LINGERING THROUGH MID- MORNING...BUT MVFR CEILINGS LOOK UNLIKELY. SYNOPTIC-SCALE MOS GUIDANCE WAS CONFOUNDED BY DEW POINTS IN THE MID-70S DURING JULY...BUT THE 00Z NAM SUNDAY EVENING DID KEY ON THE LIKELIHOOD FOR LOW CEILINGS MONDAY MORNING. DESPITE CONSIDERABLE MOISTURE REMAINING IN PLACE...THE CURRENT MOS OUTPUT IS VFR FOR TUESDAY MORNING. THE LATEST RAP PERFECT PROGS SUGGEST THE BEST POTENTIAL FOR A THIN LAYER OF TROPICAL STRATUS WOULD BE EAST OF THE I-35 CORRIDOR. IT IS IMPORTANT TO NOTE THAT THIS POTENTIAL STRATUS SCENARIO DEPENDS ON THE ABILITY OF THE LAYER TO DEVELOP IN THE VICINITY OF OUR TAF SITES...NOT ON THE ADVECTION OF UPSTREAM STRATUS. SURFACE RIDGING OVER THE GULF SHOULD VEER THE LOW-LEVEL WINDS UPSTREAM...EFFECTIVELY CLOSING OFF THE GULF FROM ADDITIONAL MOIST ADVECTION OVERNIGHT. BUT OUR BOUNDARY LAYER MOISTURE IS ALREADY IN PLACE AND...WITH NEGLIGIBLE ADVECTION...IS LIKELY TO REMAIN UNCHANGED BY DAYBREAK TUESDAY. WILL CONTINUE TO MONITOR MESOSCALE OUTPUT THIS EVENING...BUT DO NOT ANTICIPATE NEEDING TO INTRODUCE CEILINGS WITH THE 03Z AMENDMENTS OR 06Z ROUTINE TAFS. 25 && .PREV DISCUSSION... /ISSUED 311 PM CDT MON JUL 21 2014/ SUMMER HEAT HAS QUICKLY RETURNED TO NORTH TEXAS TODAY WITH HOT AND HUMID CONDITIONS AREA-WIDE. TEMPERATURES IN THE 90S COMBINED WITH DEWPOINTS IN THE LOWER TO MIDDLE 70S HAVE CREATED HEAT INDICES IN THE 100-105 RANGE IN MANY LOCATIONS THIS AFTERNOON. ABOVE-NORMAL TEMPERATURES CAN BE EXPECTED FOR THE REST OF THE WEEK DUE MAINLY TO THE STRENGTHENING OF A MID AND UPPER LEVEL RIDGE OVER MUCH OF THE REGION. THE RIDGE AXIS IS CENTERED OVER COLORADO AND NEW MEXICO BUT STRETCHES EASTWARD ACROSS THE SOUTHERN PLAINS AND NORTH TEXAS...WITH LITTLE OVERALL CHANGE IN POSITION EXPECTED THIS WEEK. EAST OF THE RIDGE...A WEAK UPPER LOW CAN BE SEEN ON SATELLITE GENERATING CONVECTION OVER THE SOUTHEASTERN STATES. THIS LOW WILL SLOWLY MOVE WEST OVER THE NEXT COUPLE OF DAYS. NORTH TEXAS WILL RESIDE IN BETWEEN THE RIDGE TO THE WEST AND THE LOW TO THE EAST...WHICH WILL GENERATE NORTHEAST FLOW ALOFT THROUGH THURSDAY. A SUBTLE SHORTWAVE IS STILL PROGGED TO ROTATE SOUTHWEST ACROSS THE ARKLATEX REGION WEDNESDAY NIGHT....BRINGING WITH IT ENOUGH MOISTURE AND LIFT TO PRODUCE SCATTERED CONVECTION OVER NORTHEAST PORTIONS OF NORTH TEXAS. THE BEST CHANCES FOR SHOWERS AND STORMS WILL OCCUR NEAR PARIS...WHERE WE WILL GO AHEAD AND INCLUDE CHANCE POPS WEDNESDAY NIGHT. SLIGHT CHANCE POPS WILL BE INCLUDED IN AREAS SOUTHWEST OF LAMAR COUNTY INCLUDING DALLAS/FORT WORTH AND SURROUNDING LOCALES. THERE IS A CHANCE THAT THUNDERSTORMS WILL BECOME SOMEWHAT ORGANIZED AS THEY APPROACH FROM THE NORTHEAST LATE WEDNESDAY...PERHAPS FORMING INTO A SOUTHWEST MOVING MCS. IF THIS BEGINS TO APPEAR MORE LIKELY IN FUTURE MODEL DATA...HIGHER POPS MAY BE NEEDED FOR THE NORTHEASTERN THIRD OF THE REGION. THE NORTHEAST FLOW REGIME WILL ALLOW A WEAK FRONT TO SAG SOUTH ACROSS THE RED RIVER...BECOMING STATIONARY NORTH OF I-20 ON THURSDAY. THIS BOUNDARY COULD PROVIDE FOCUS FOR ISOLATED STORMS... AND WE WILL CONTINUE WITH 20 POPS OVER THE EASTERN HALF OF THE REGION THURSDAY. WESTERN COUNTIES WILL MOST LIKELY BE TOO HEAVILY IMPACTED BY SUBSIDENCE FROM THE CO/NM RIDGE FOR THE INCLUSION OF POPS. THE HIGH PRESSURE RIDGE WILL EXPAND LONGITUDINALLY LATE THIS WEEK THROUGH THE WEEKEND...REACHING AS FAR EAST AS THE TENNESSEE VALLEY FRIDAY. HOT AND RAIN-FREE WEATHER IS EXPECTED AS A RESULT ACROSS A LARGE PORTION OF TEXAS. THE MAIN WEATHER CONCERN WILL BE THE DAYTIME TEMPERATURES THIS WEEKEND...WITH CURRENT APPARENT TEMPERATURE GRIDS PRODUCING HEAT INDICES IN EXCESS OF 105 DURING THE AFTERNOON HOURS FRIDAY AND SATURDAY. WE WILL MONITOR OUR FORECAST TEMPERATURE/DEWPOINT TRENDS AS THE WEEKEND APPROACHES...AND MAY HAVE TO CONSIDER A HEAT ADVISORY IF IT APPEARS THAT THESE CONDITIONS WILL BECOME FAIRLY WIDESPREAD. THERE MAY BE SOME RELIEF IN SIGHT EARLY NEXT WEEK...AS MID RANGE MODELS CONTINUE TO INDICATE A DEEPENING UPPER TROUGH OVER THE EASTERN HALF OF THE NATION WHILE THE UPPER RIDGE RETROGRADES WEST. THIS MAY BRING SOME COOLER WEATHER ALONG WITH INCREASED RAIN CHANCES AS WE MOVE THROUGH NEXT WEEK. 30 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 77 98 78 99 78 / 0 5 5 10 20 WACO, TX 74 98 74 99 73 / 5 5 5 5 10 PARIS, TX 70 95 72 96 75 / 0 5 5 20 30 DENTON, TX 73 97 74 98 75 / 0 5 5 10 20 MCKINNEY, TX 72 98 73 99 74 / 0 5 5 10 20 DALLAS, TX 78 98 79 99 78 / 0 5 5 10 20 TERRELL, TX 75 98 75 99 75 / 0 5 5 10 20 CORSICANA, TX 75 97 75 98 75 / 5 5 5 10 20 TEMPLE, TX 74 98 73 99 73 / 5 5 5 5 10 MINERAL WELLS, TX 72 99 73 100 73 / 0 5 5 5 20 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 25/58
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1256 PM EDT SUN JUL 20 2014 .SYNOPSIS... A WEAK WEDGE OF HIGH PRESSURE WILL REMAIN OVER THE AREA THIS AFTERNOON BEFORE SLIDING OFF THE MID ATLANTIC COAST OVERNIGHT. A RESIDUAL WEAK FRONTAL BOUNDARY AND UPPER DISTURBANCE ACROSS THE CAROLINAS WILL LIFT SLOWLY NORTH INTO THE REGION EARLY NEXT WEEK. THIS WILL RESULT IN CONTINUED UNSETTLED WEATHER INTO MID WEEK AHEAD OF A STRONGER COLD FRONT THAT IS EXPECTED TO ARRIVE ON THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM EDT SUNDAY... WEAK WEDGE OF COOL AIR REMAINS IN PLACE EARLY THIS MORNING BUT NOT AS STRONG AS SATURDAY GIVEN LACK OF RE-ENFORCING PRECIP...WITH EVEN SOME BREAKS SHOWING UP JUST WEST OF THE NEW RIVER VALLEY. THIS MAY ALLOW FOR A PERIOD OF SUNSHINE ESPCLY FAR SW VA INTO SE WVA WHERE LACK OF LOW CLOUDS BEFORE THE FAINT SHORTWAVE NOW WEST OF THE MOUNTAINS SLIDES EAST LATER IN THE DAY AND CAUSES CLOUDS/SHRA TO FILL BACK IN. LATEST GUIDANCE ALSO SHOWS SOME WIDELY SCTD SHRA/TSRA DEVELOPMENT MOUNTAINS WITH THIS FEATURE ESPCLY AFTER 18Z WHEN MODELS INDICATE SOME MODEST 1000-1500 J/KG CAPE OVER THE FAR WEST. THEREFORE CUT BACK ON POPS TO INIT BASED ON CURRENT RADAR TRENDS AND ADDED IN A BIT MORE TSRA I-77 CORRIDOR LATER ON PER LATEST HRRR AND NCEP WRF. CANT TOTALLY RULE OUT ISOLATED -TSRA SE PIEDMONT BUT APPEARS LACK OF MUCH INSTABILITY AND BETTER LIFT REMAINING SOUTH CLOSER TO THE OLD FRONT SHOULD PRECLUDE MUCH MORE THAN SHOWERS AT THIS POINT. OTRW KEEPING SLIGHT TO CHANCE POPS WITH HIGHEST ENDING UP FAR WEST LATER ON AND LEAST ACROSS THE NE UNDER THE WEAKENING WEDGE. EVEN WITH SOME SUN...COOLER MET MOS TEMPS STILL LOOK BEST SO KEPT VALUES CLOSE TO THE CURRENT FORECAST WHICH KEEPS MOST IN THE 70S...ALTHOUGH THE NW NC BLUE RIDGE SPOTS MAY STRUGGLE IN THE 60S MOST OF THE DAY. PREVIOUS VALID DISCUSSION... UPPER LEVEL TROUGH OVER THE EASTERN U.S. WILL REMAIN IN PLACE TODAY AND TONIGHT WITH WEAK RIDGING FROM NEW ENGLAND CONTINUING TO MAINTAIN A WEAK EASTERLY LOW-LEVEL WIND COMPONENT INTO THE MID- ATLANTIC AND CENTRAL APPALACHIANS PRODUCING SUBTLE COOL-AIR DAMMING. WITH VERY LITTLE FORCING EXPECTED AT THE SURFACE AND ALOFT THERE SEEMS TO BE LITTLE OBVIOUS TRIGGER FOR SHOWER ACTIVITY BUT THE AIR MASS THE OVERHEAD WILL REMAIN QUITE MOIST WITH PWATS HOLDING NEAR 1.5 INCHES ACROSS MOST OF THE CWA...00Z/20 RAOB FROM KRNK HAD 1.48 INCHES WHICH IS ABOUT THE 75TH PERCENTILE FOR DATE IN JULY...ALSO RIGHT AT THE CLIMATOLOGICAL MAXIMA FOR THE YEAR. THAT SAID THE QUESTION REMAINS WHETHER WE CAN DEVELOP ANY CONVECTION AT ALL TODAY AND THAT MAY DEPEND ON SOME BREAKS IN THE PERSISTENT OVERCAST. BEST CHANCES FOR ANY SHOWERS OR EVEN A THUNDERSTORM TO DEVELOP WILL BE IN FAR WEST WHICH WILL BE LESS UNDER THE INFLUENCE OF THE WEDGE. MODEL CAPES FROM ARW_RNK REACH 1000 J/KG BY LATE AFTERNOON AT BLUEFIELD SO PUT ISOLATED THUNDER CHANCES IN THE WEST ALONG WITH CHANCE POPS GENERALLY FROM BLUE RIDGE WESTWARD AND ONLY SLIGHT CHANCE EAST. BEST SYNOPTIC FORCING FOR PRECIPITATION WILL BE WELL SOUTH OF OUR CWA IN ASSOCIATION WITH SHORT-WAVE AND WEAK LOW DOWN ALONG THE GULF COAST. SOME OF THIS ACTIVITY MAY REACH OUR SOUTHERN COUNTIES BUT AMOUNTS SHOULD BE QUITE MODEST...GENERALLY UNDER 0.25 INCHES ON A MEAN AREAL BASIS. TEMPS TRICKY AS WELL TODAY WITH CLOUDS/JULY SUN GAME IN FULL SWING. USED MODEL BLEND BUT A FEW HOURS OF EXTRA HEATING COULD PLAY HAVOC WITH CURRENT MID-70S WEST TO LOW 80S EAST FORECAST. && .SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/... AS OF 430 AM EDT SUNDAY... FOCUS THROUGH THIS PERIOD WILL EVOLVE AROUND A PERSISTENT TROUGH ALONG THE SOUTHEAST U.S. COAST LEFT BEHIND FROM THE CURRENT UPPER TROUGH AS IT LIFTS OUT. WITH TIME...THIS SYSTEM ASSUMES A PSEUDO TROPICAL CHARACTERISTIC AND DRIFTS SLOWLY NORTHWESTWARD AS A MAMMOTH UPPER RIDGE BUILDS ACROSS THE WESTERN U.S. AND RIDGES EASTWARD TOWARD THE GREAT LAKES WHILE ANOTHER UPPER RIDGE AMPLIFIES IN THE WEST ATLANTIC. THIS WILL FORCE THIS FEATURE TO RETROGRADE FROM THE GA/SC COAST NORTHWESTWARD TOWARD THE SOUTHERN APPALACHIANS THROUGH THE PERIOD. FINALLY...THE LONG RANGE MODELS HAVE COME INTO REASONABLY GOOD AGREEMENT ON THE EVOLUTION AND TRACK OF THIS SYSTEM. AS THIS SYSTEM DRIFTS NORTHWEST TOWARD THE REGION DURING THE FIRST HALF OF THE WEEK...PWS WILL RISE TO NEAR 2.0 INCHES. THIS ALONG WITH INCREASING HEAT AND INSTABILITY SHOULD SUPPORT AN INCREASE IN DIURNAL CONVECTION. THE BEST CHANCES FOR SUCH SHOULD REMAIN FOCUSED ACROSS NW NC/FAR SW VA WHERE MOIST SOUTHEAST UPSLOPE FLOW WILL BE ENHANCED ALONG THE BLUE RIDGE. EXPECT SCATTERED DIURNAL CONVECTION AREA WIDE...WITH NUMEROUS AFTERNOON/EVENING SHRA/TSRA ACROSS NW NC AND FAR SW VA THROUGH THE PERIOD. CONSEQUENTLY...HAVE ADVERTISED HIGH CHC TO LOW LIKELY POPS IN THESE AREAS THROUGH THE PERIOD DURING THE AFTERNOON HOURS. FOR MUCH OF THE AREA THIS WILL RESULT IN INCREASING CHANCES OF BENEFICIAL RAIN...BUT SLOW MOVING/TRAINING THUNDERSTORMS...ESPECIALLY ACROSS THE MOUNTAINS TERRAIN OF NW NC/FAR SW VA COULD BECOME MORE PROBLEMATIC AS THE WEEK PROGRESSES. ALTHOUGH INSTABILITY WILL BE HIGH...DYNAMICS/SHEAR ARE WEAK. HOWEVER...AN ISOLATED PULSE SEVERE WITH STRONG WIND GUSTS COULD NOT BE COMPLETELY RULED OUT THROUGH THE PERIOD ANYWHERE IN THE CWA FOR THAT MATTER. 850MB TEMPS WILL BE ON THE INCREASE AS HEIGHTS ALOFT RISE AS WELL. HOWEVER...INCREASING DEWPOINTS/PWS AND PERSISTENT TROUGHINESS ACROSS THE REGION WILL TEMPER ANY EXCESSIVE HEAT AND SHOULD KEEP MOST AREAS IN THE 80S FOR HIGHS...70S IN THE MOUNTAINS...NEAR 90 ACROSS THE PIEDMONT. WEDNESDAY WILL BE THE WARMEST DAY IN ADVANCE OF THE FRONT/UPPER TROUGH APPROACHING FROM THE NORTHWEST. && .LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 445 PM EDT SATURDAY... UPPER RIDGE IS FORECAST TO REMAIN OVER THE WESTERN CONUS THROUGH THE LONG TERM...WITH A PERSISTENT UPPER TROUGH OVER THE EASTERN CONUS. A STRONG SHORT WAVE TRACKS FROM SOUTH CENTRAL CANADA ATOP THE UPPER RIDGE TOWARD THE GREAT LAKES. THIS DRIVES A FRONTAL SYSTEM INTO THE EASTERN U.S. AND OUR REGION BY THURSDAY. ECMWF/GFS ARE IN REASONABLE AGREEMENT ON THE PROGRESSION AND TIMING OF THESE FEATURES. THE FRONT SHOULD PUSH JUST SOUTH OF THE AREA BY FRI...ALTHOUGH AT THIS TIME OF YEAR THERE IS ALWAYS SOME UNCERTAINTY AS TO HOW FAR SOUTH THE FRONT WILL GO BEFORE STALLING. THE STRENGTH OF THE NORTHWEST FLOW ALOFT IN OUR REGION OWING TO THE STRONG UPPER RIDGE OUT WEST SHOULD SUPPORT THE FRONT PUSHING SOUTH OF THE CWA AT A MINIMUM. THE GREATEST CHANCE FOR SHOWERS/STORMS WILL BE THURSDAY AND THERE IS SOME CHANCE THAT THE LINGERING PSEUDO TROPICAL SYSTEM ACROSS THE CENTRAL/SOUTHERN APPALACHIANS AND ASSOCIATED MOISTURE COULD ENHANCE SHRA/TSRA CHANCES ALONG THE FRONT. FRIDAY STILL LOOKS LIKE A DRY DAY WITH THE FRONTAL BOUNDARY SOUTH OF THE CWA. MOISTURE COULD RETURN TO WESTERN AREAS BY SAT...BUT HAVE KEPT POPS LOW AT THIS POINT WITH TOO MUCH UNCERTAINTY ON ANY UPSTREAM NW FLOW DISTURBANCES. AFTER A VERY WARM DAY WED...THURSDAY WILL BE A TRANSITION DAY WITH THE FRONTAL PASSAGE...FOLLOWED BY A 4 TO 7 DEGREE DOWNWARD TREND IN TEMPERATURES FOR FRIDAY AND SATURDAY. USED A GFS/ECMWF MOS MODEL BLEND THROUGH THE PERIOD. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... AS OF 1235 PM EDT SUNDAY... WEDGE WILL CONTINUE TO KEEP LOWER MVFR CIGS LOCKED IN OVER THE WESTERN LOCATIONS THIS AFTERNOON WITH GRADUAL IMPROVEMENT TO VFR UNDER SOME BREAKS IN THE EAST. EXPECT MOST SHOWERS TO REMAIN CONFINED TO THE KBLF/KLWB AREAS THIS AFTERNOON WITH PERIODS OF MVFR POSSIBLE INCLUDING AN ISOLATED -TSRA AS WEAK INSTABILITY DEVELOPS AND A WEAK WAVE ALOFT CROSSES. OTRW OTHER THAN A VICINITY MENTION...KEEPING SHRA OUT OF THE TAFS THE REST OF THE AFTERNOON UNDER A LIGHT SE WIND. IMPULSE PASSES TO THE NORTH LATER TONIGHT WHICH SHOULD HELP TAPER OFF ANY SIGNIFICANT LEFTOVER SHRA OVER THE WEST OVERNIGHT. HOWEVER CONTINUED SE FLOW COMBINED WITH DEEP MOISTURE BETWEEN THE SFC-7H WILL CAUSE CIGS TO AGAIN LOWER...WITH WIDESPREAD MVFR EXPECTED ESPCLY AFTER MIDNIGHT. COULD ALSO SEE PERIODS OF IFR/LIFR AT KLWB AND ALONG THE BLUE RIDGE WHERE SOME PATCHY -DZ AND FOG POSSIBLE. ISOLATED SHRA MAY TEND TO LIMIT LOWER CLOUD FORMATION ACROSS THE SE AS WELL AS AROUND KBLF WHERE WILL SEE WEAK DOWNSLOPING. WAVE TO THE SOUTH WILL CAUSE THE FLOW TO TURN MORE EASTERLY ON MONDAY ALLOWING THE WEDGE TO ENHANCE A BIT MORE. THIS MAY KEEP AT LEAST MVFR CIGS AROUND ESPCLY BLUE RIDGE WEST INTO THE AFTERNOON BUT EXPECT MOST SHOWERS TO BE CONFINED TO SOUTHERN AREAS MAINLY KTNB-KUKF TO KDAN. MORE BREAKS ALONG WITH VFR EXPECTED A BIT SOONER ACROSS THE NORTH ALONG THE KLWB-KLYH CORRIDOR BY MONDAY AFTERNOON WITH A MIX OF MVFR/VFR AT KBCB/KROA TO KBLF LIKELY. EXTENDED AVIATION DISCUSSION... UPPER SYSTEM IN THE BASE OF THE FADING SE TROUGH WILL WEAKEN AND LIFT NORTH TUESDAY INTO WEDNESDAY IN ADVANCE OF AN APPROACHING COLD FRONT FOR THU. THIS WILL RESULT IN MORE WIDESPREAD DIURNAL CONVECTION EACH DAY WITH EARLY FOG IN SPOTS GIVING WAY TO BRIEF VFR...THEN PERIODIC MVFR IN CLOUDS/SHRA EACH AFTERNOON/EVENING. A COLD FRONT LOOKS TO PUSH THROUGH ON THURSDAY WITH BETTER COVERAGE OF MVFR/IFR PRODUCING SHOWERS AND STORMS. IMPROVED AVIATION CONDITIONS ARE EXPECTED FRIDAY BEHIND THE FRONT WITH CLEARING SKIES AND LITTLE TO NO PRECIPITATION...EXPECT POSSIBLY KDAN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/PC NEAR TERM...JH/PC SHORT TERM...RAB LONG TERM...PM/RAB AVIATION...JH/PC/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1002 AM EDT SUN JUL 20 2014 .SYNOPSIS... A WEAK WEDGE OF HIGH PRESSURE WILL REMAIN OVER THE AREA TODAY BEFORE SLIDING OFF THE MID ATLANTIC COAST OVERNIGHT. A RESIDUAL WEAK FRONTAL BOUNDARY ACROSS THE CAROLINAS WILL LIFT SLOWLY NORTH INTO THE REGION ON MONDAY RESULTING IN CONTINUED UNSETTLED WEATHER INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM EDT SUNDAY... WEAK WEDGE OF COOL AIR REMAINS IN PLACE EARLY THIS MORNING BUT NOT AS STRONG AS SATURDAY GIVEN LACK OF RE-ENFORCING PRECIP...WITH EVEN SOME BREAKS SHOWING UP JUST WEST OF THE NEW RIVER VALLEY. THIS MAY ALLOW FOR A PERIOD OF SUNSHINE ESPCLY FAR SW VA INTO SE WVA WHERE LACK OF LOW CLOUDS BEFORE THE FAINT SHORTWAVE NOW WEST OF THE MOUNTAINS SLIDES EAST LATER IN THE DAY AND CAUSES CLOUDS/SHRA TO FILL BACK IN. LATEST GUIDANCE ALSO SHOWS SOME WIDELY SCTD SHRA/TSRA DEVELOPMENT MOUNTAINS WITH THIS FEATURE ESPCLY AFTER 18Z WHEN MODELS INDICATE SOME MODEST 1000-1500 J/KG CAPE OVER THE FAR WEST. THEREFORE CUT BACK ON POPS TO INIT BASED ON CURRENT RADAR TRENDS AND ADDED IN A BIT MORE TSRA I-77 CORRIDOR LATER ON PER LATEST HRRR AND NCEP WRF. CANT TOTALLY RULE OUT ISOLATED -TSRA SE PIEDMONT BUT APPEARS LACK OF MUCH INSTABILITY AND BETTER LIFT REMAINING SOUTH CLOSER TO THE OLD FRONT SHOULD PRECLUDE MUCH MORE THAN SHOWERS AT THIS POINT. OTRW KEEPING SLIGHT TO CHANCE POPS WITH HIGHEST ENDING UP FAR WEST LATER ON AND LEAST ACROSS THE NE UNDER THE WEAKENING WEDGE. EVEN WITH SOME SUN...COOLER MET MOS TEMPS STILL LOOK BEST SO KEPT VALUES CLOSE TO THE CURRENT FORECAST WHICH KEEPS MOST IN THE 70S...ALTHOUGH THE NW NC BLUE RIDGE SPOTS MAY STRUGGLE IN THE 60S MOST OF THE DAY. PREVIOUS VALID DISCUSSION... UPPER LEVEL TROUGH OVER THE EASTERN U.S. WILL REMAIN IN PLACE TODAY AND TONIGHT WITH WEAK RIDGING FROM NEW ENGLAND CONTINUING TO MAINTAIN A WEAK EASTERLY LOW-LEVEL WIND COMPONENT INTO THE MID- ATLANTIC AND CENTRAL APPALACHIANS PRODUCING SUBTLE COOL-AIR DAMMING. WITH VERY LITTLE FORCING EXPECTED AT THE SURFACE AND ALOFT THERE SEEMS TO BE LITTLE OBVIOUS TRIGGER FOR SHOWER ACTIVITY BUT THE AIR MASS THE OVERHEAD WILL REMAIN QUITE MOIST WITH PWATS HOLDING NEAR 1.5 INCHES ACROSS MOST OF THE CWA...00Z/20 RAOB FROM KRNK HAD 1.48 INCHES WHICH IS ABOUT THE 75TH PERCENTILE FOR DATE IN JULY...ALSO RIGHT AT THE CLIMATOLOGICAL MAXIMA FOR THE YEAR. THAT SAID THE QUESTION REMAINS WHETHER WE CAN DEVELOP ANY CONVECTION AT ALL TODAY AND THAT MAY DEPEND ON SOME BREAKS IN THE PERSISTENT OVERCAST. BEST CHANCES FOR ANY SHOWERS OR EVEN A THUNDERSTORM TO DEVELOP WILL BE IN FAR WEST WHICH WILL BE LESS UNDER THE INFLUENCE OF THE WEDGE. MODEL CAPES FROM ARW_RNK REACH 1000 J/KG BY LATE AFTERNOON AT BLUEFIELD SO PUT ISOLATED THUNDER CHANCES IN THE WEST ALONG WITH CHANCE POPS GENERALLY FROM BLUE RIDGE WESTWARD AND ONLY SLIGHT CHANCE EAST. BEST SYNOPTIC FORCING FOR PRECIPITATION WILL BE WELL SOUTH OF OUR CWA IN ASSOCIATION WITH SHORT-WAVE AND WEAK LOW DOWN ALONG THE GULF COAST. SOME OF THIS ACTIVITY MAY REACH OUR SOUTHERN COUNTIES BUT AMOUNTS SHOULD BE QUITE MODEST...GENERALLY UNDER 0.25 INCHES ON A MEAN AREAL BASIS. TEMPS TRICKY AS WELL TODAY WITH CLOUDS/JULY SUN GAME IN FULL SWING. USED MODEL BLEND BUT A FEW HOURS OF EXTRA HEATING COULD PLAY HAVOC WITH CURRENT MID-70S WEST TO LOW 80S EAST FORECAST. && .SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/... AS OF 430 AM EDT SUNDAY... FOCUS THROUGH THIS PERIOD WILL EVOLVE AROUND A PERSISTENT TROUGH ALONG THE SOUTHEAST U.S. COAST LEFT BEHIND FROM THE CURRENT UPPER TROUGH AS IT LIFTS OUT. WITH TIME...THIS SYSTEM ASSUMES A PSEUDO TROPICAL CHARACTERISTIC AND DRIFTS SLOWLY NORTHWESTWARD AS A MAMMOTH UPPER RIDGE BUILDS ACROSS THE WESTERN U.S. AND RIDGES EASTWARD TOWARD THE GREAT LAKES WHILE ANOTHER UPPER RIDGE AMPLIFIES IN THE WEST ATLANTIC. THIS WILL FORCE THIS FEATURE TO RETROGRADE FROM THE GA/SC COAST NORTHWESTWARD TOWARD THE SOUTHERN APPALACHIANS THROUGH THE PERIOD. FINALLY...THE LONG RANGE MODELS HAVE COME INTO REASONABLY GOOD AGREEMENT ON THE EVOLUTION AND TRACK OF THIS SYSTEM. AS THIS SYSTEM DRIFTS NORTHWEST TOWARD THE REGION DURING THE FIRST HALF OF THE WEEK...PWS WILL RISE TO NEAR 2.0 INCHES. THIS ALONG WITH INCREASING HEAT AND INSTABILITY SHOULD SUPPORT AN INCREASE IN DIURNAL CONVECTION. THE BEST CHANCES FOR SUCH SHOULD REMAIN FOCUSED ACROSS NW NC/FAR SW VA WHERE MOIST SOUTHEAST UPSLOPE FLOW WILL BE ENHANCED ALONG THE BLUE RIDGE. EXPECT SCATTERED DIURNAL CONVECTION AREA WIDE...WITH NUMEROUS AFTERNOON/EVENING SHRA/TSRA ACROSS NW NC AND FAR SW VA THROUGH THE PERIOD. CONSEQUENTLY...HAVE ADVERTISED HIGH CHC TO LOW LIKELY POPS IN THESE AREAS THROUGH THE PERIOD DURING THE AFTERNOON HOURS. FOR MUCH OF THE AREA THIS WILL RESULT IN INCREASING CHANCES OF BENEFICIAL RAIN...BUT SLOW MOVING/TRAINING THUNDERSTORMS...ESPECIALLY ACROSS THE MOUNTAINS TERRAIN OF NW NC/FAR SW VA COULD BECOME MORE PROBLEMATIC AS THE WEEK PROGRESSES. ALTHOUGH INSTABILITY WILL BE HIGH...DYNAMICS/SHEAR ARE WEAK. HOWEVER...AN ISOLATED PULSE SEVERE WITH STRONG WIND GUSTS COULD NOT BE COMPLETELY RULED OUT THROUGH THE PERIOD ANYWHERE IN THE CWA FOR THAT MATTER. 850MB TEMPS WILL BE ON THE INCREASE AS HEIGHTS ALOFT RISE AS WELL. HOWEVER...INCREASING DEWPOINTS/PWS AND PERSISTENT TROUGHINESS ACROSS THE REGION WILL TEMPER ANY EXCESSIVE HEAT AND SHOULD KEEP MOST AREAS IN THE 80S FOR HIGHS...70S IN THE MOUNTAINS...NEAR 90 ACROSS THE PIEDMONT. WEDNESDAY WILL BE THE WARMEST DAY IN ADVANCE OF THE FRONT/UPPER TROUGH APPROACHING FROM THE NORTHWEST. && .LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 445 PM EDT SATURDAY... UPPER RIDGE IS FORECAST TO REMAIN OVER THE WESTERN CONUS THROUGH THE LONG TERM...WITH A PERSISTENT UPPER TROUGH OVER THE EASTERN CONUS. A STRONG SHORT WAVE TRACKS FROM SOUTH CENTRAL CANADA ATOP THE UPPER RIDGE TOWARD THE GREAT LAKES. THIS DRIVES A FRONTAL SYSTEM INTO THE EASTERN U.S. AND OUR REGION BY THURSDAY. ECMWF/GFS ARE IN REASONABLE AGREEMENT ON THE PROGRESSION AND TIMING OF THESE FEATURES. THE FRONT SHOULD PUSH JUST SOUTH OF THE AREA BY FRI...ALTHOUGH AT THIS TIME OF YEAR THERE IS ALWAYS SOME UNCERTAINTY AS TO HOW FAR SOUTH THE FRONT WILL GO BEFORE STALLING. THE STRENGTH OF THE NORTHWEST FLOW ALOFT IN OUR REGION OWING TO THE STRONG UPPER RIDGE OUT WEST SHOULD SUPPORT THE FRONT PUSHING SOUTH OF THE CWA AT A MINIMUM. THE GREATEST CHANCE FOR SHOWERS/STORMS WILL BE THURSDAY AND THERE IS SOME CHANCE THAT THE LINGERING PSEUDO TROPICAL SYSTEM ACROSS THE CENTRAL/SOUTHERN APPALACHIANS AND ASSOCIATED MOISTURE COULD ENHANCE SHRA/TSRA CHANCES ALONG THE FRONT. FRIDAY STILL LOOKS LIKE A DRY DAY WITH THE FRONTAL BOUNDARY SOUTH OF THE CWA. MOISTURE COULD RETURN TO WESTERN AREAS BY SAT...BUT HAVE KEPT POPS LOW AT THIS POINT WITH TOO MUCH UNCERTAINTY ON ANY UPSTREAM NW FLOW DISTURBANCES. AFTER A VERY WARM DAY WED...THURSDAY WILL BE A TRANSITION DAY WITH THE FRONTAL PASSAGE...FOLLOWED BY A 4 TO 7 DEGREE DOWNWARD TREND IN TEMPERATURES FOR FRIDAY AND SATURDAY. USED A GFS/ECMWF MOS MODEL BLEND THROUGH THE PERIOD. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... AS OF 735 AM EDT SUNDAY... GENERALLY POOR AVIATION CONDITIONS EXPECTED TO CONTINUE WEST OF THE BLUE RIDGE...WITH MARGINAL AVIATION CONDITIONS EAST OF THE BLUE RIDGE. UPPER TROUGH WILL LINGER ACROSS THE EASTERN U.S. THROUGH THE PERIOD. A PSUEDO TROPICAL UPPER DISTURBANCE WILL DEVELOP ALONG THE GA/SC COAST TODAY INTO MONDAY...THEN RETROGRADE NW BETWEEN EXPANDING WESTERN ATLANTIC UPPER RIDGE AND WESTERN CONUS UPPER RIDGE. SYSTEM WILL REMAIN TRAPPED ACROSS THE SOUTHERN-CENTRAL APPALACHIANS THROUGH MID-WEEK. LATEST MODEL RUNS SUPPORT -SHRA SKIRTING KDAN THROUGH MID-MORNING WITH LOW END VFR OR HIGH END MVFR CIGS...LIKELY VFR VSBYS. BY AFTERNOON...EXPECT SHRA AND EVEN A FEW TSRA TO DEVELOP ACROSS THE ALLEGHANYS...INCLUDING LWB/BLF/BCB...SPREADING EAST TOWARD ROA AROUND SUNSET. FOR NOW...HAVE CONFINED MENTION OF TSRA TO BLF WHERE BEST INSTABILITY WILL EXIST. OVERNIGHT...THIS ACTIVITY SHOULD GRADUALLY DISSIPATE...BUT EXPECT LOWERING CIGS/VSBYS MOST AREAS AFT 06Z IN STRATUS/FOG TO MVFR...WITH POTENTIAL FOR IFR BCB/BLF/LWB AFT 08Z. DEEPER MOISTURE SPREADING NORTH AND WEAK SE FLOW SHOULD PROMOTE DRIZZLE THROUGH THE NEW RIVER...GREENBRIER...AND POTENTIALLY EVEN THE ROANOKE VALLEYS LATE TONIGHT/EARLY MON. WINDS THROUGH THE PERIOD REMAINING LIGHT SE 5KTS OR LESS. MEDIUM CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID PERIOD. MEDIUM CONFIDENCE IN TSRA POTENTIAL THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND SPD/DIR THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... THE AFOREMENTIONED UPPER DISTURBANCE WILL TRACK TOWARD NW NC MON AND STALL/SHEAR OUT ACROSS THE SOUTHERN-CENTRAL APPALACHIANS TUE-WED IN ADVANCE OF AN APPROACHING COLD FRONT FOR THU. EXPECT SCT-NMRS DIURNAL CONVECTION EACH DAY...WITH THE BEST CHANCE/COVERAGE THROUGH THE ALLEGHANYS AND WEST OF THE BLUE RIDGE. FRONTAL SYSTEM THU WILL BRING MORE WIDESPREAD SHRA/TSRA TO ALL AREAS. PERIODS OF MVFR WITH LOCALIZED IFR CIGS CAN BE EXPECTED THROUGH THU. THE HIGH MOISTURE CONTENT IN THE ATMOSPHERE AND DAILY -SHRA WILL PROMOTE DEVELOPMENT OF LATE NIGHT/EARLY MORNING FOG...ESPECIALLY IN THE USUAL SUCH PRONE LOCATIONS...NAMELY LWB/BCB/LYH. IMPROVED AVIATION CONDITIONS ARE EXPECTED FRIDAY BEHIND THE FRONT WITH CLEARING SKIES AND LITTLE TO NO PRECIPITATION...EXPECT POSSIBLY KDAN. && .CLIMATE... THE PERSISTENT LOW CLOUD COVER...DRIZZLE AND EASTERLY FLOW COMBINED TO PRODUCE THREE NEW RECORD LOW MAXIMA FOR THE DATE YESTERDAY JULY 19 2014. BLACKSBURG...LEWISBURG AND BLUEFIELD ALL SET NEW DATE RECORDS...BY 6 DEGREES F IN THE CASE OF BLACKSBURG. SEE WBCRERRNK FOR DETAILS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/PC NEAR TERM...JH/PC SHORT TERM...RAB LONG TERM...PM/RAB AVIATION...PC/RAB CLIMATE...PC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
918 PM CDT MON JUL 21 2014 .UPDATE...OVERNIGHT ISSUED AT 918 PM CDT MON JUL 21 2014 THE MCS CURRENTLY DEVELOPING ACROSS EASTERN NORTH DAKOTA INTO NORTHWEST MINNESOTA IS THE FORECAST CONCERN FOR THE LOCAL AREA. LATEST GUIDANCE SUGGESTS THAT THE 700-800 MB CAP WILL REMAIN STRONG ENOUGH TO KEEP THE COMPLEX FROM DROPPING TOO MUCH SOUTHEAST. CORFIDI VECTORS AND MCS MOTION WOULD SUGGEST A PATH MORE ACROSS NORTHERN MINNESOTA INTO NORTHERN WISCONSIN...WITH A SLIGHT POSSIBILITY OF CLIPPING THE FAR NORTHERN CWA. THUS...THE THREAT FOR A DAMAGING WIND EVENT FOR THE AREA CONTINUES TO DROP. THERE ARE SUGGESTIONS THAT THERE WILL BE AN INCREASE IN 850-700 MB MOISTURE TRANSPORT OVERNIGHT...AND THAT THE CAP WILL WEAKEN ENOUGH TO ALLOW SHOWERS/STORMS TO DEVELOP TOWARD 10-12Z...MAINLY ACROSS WESTERN INTO CENTRAL WISCONSIN. THIS WOULD BE IN CONJUNCTION WITH THE PASSING MCS TO THE NORTH. THE LATEST RUNS OF THE RAP/HRRR SUGGEST THIS IDEA COULD OCCUR AS WELL...SO HAVE ADJUSTED PRECIPITATION CHANCES TO MAINLY AFTER 08Z FOR WESTERN INTO CENTRAL WISCONSIN. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 331 PM CDT MON JUL 21 2014 MAIN FORECAST CONCERNS ARE SEVERE THUNDERSTORM POTENTIAL LATE TONIGHT OVER NORTH CENTRAL WISCONSIN AND HEAT INDEX VALUES LATE TUESDAY MORNING INTO TUESDAY AFTERNOON OVER PORTIONS OF NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN. LATEST RADAR IMAGERY SHOWS THUNDERSTORMS DEVELOPING OVER PORTIONS OF CENTRAL NORTH DAKOTA. THESE SHOULD BE THE BIRTH OF A THUNDERSTORM COMPLEX THAT WILL RACE EAST TONIGHT ACROSS NORTHERN MINNESOTA INTO PORTIONS OF NORTHERN WISCONSIN AND UPPER MICHIGAN. MOST OF THE MESOSCALE MODEL GUIDANCE KEEPS THIS COMPLEX NORTH OF THE INTERSTATE 94 CORRIDOR. HOWEVER...THE NAM...WHICH IS A MAJOR OUTLIER AT THIS TIME...SHOWS CONVECTION FIRING OVER WEST CENTRAL MINNESOTA LATE THIS AFTERNOON INTO THIS EVENING THEN THIS CONVECTION RACES SOUTHEAST INTO THE FORECAST AREA. LOOKING AT FORECAST SOUNDINGS OVER MUCH OF THE FORECAST AREA THERE IS AN IMPRESSIVE ELEVATED MIXED LAYER WHICH IS RESULTING IN A STRONG CAP IN PLACE. THE CONVECTION WILL HAVE TO OVERCOME THIS CAP AND WITHOUT A STRONG LOW LEVEL JET THIS WILL BE DIFFICULT TO DO. THE 17Z HRRR SHOWS A FEW CELLS MAKING IN INTO WEST CENTRAL WISCONSIN AFTER MIDNIGHT SO WILL HAVE TO SEE IF THIS PANS OUT. HAVE DECIDED TO REDUCE POPS ACROSS MUCH OF THE FORECAST AREA TONIGHT WITH THE EXCEPTION OF CLARK AND TAYLOR COUNTY WHERE THE MCS COULD IMPACT THESE AREAS WITH DAMAGING WINDS THE MAY CONCERN. A COLD FRONT THEN SAGS SOUTH ACROSS THE AREA ON TUESDAY. SOME OF THE WARMEST AIR AT 925 MB MAKES IT INTO NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN WHERE 925 MB TEMPERATURES CLIMB TO AROUND 27 C. TEMPERATURES COULD CLIMB TO THE UPPER 80S TO AROUND 90 OVER PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THESE TEMPERATURES COMBINED WITH DEWPOINTS IN THE MID TO UPPER 70S WILL PRODUCE HEAT INDEX VALUES AROUND 100. THIS HEAT LOOKS TO BE VERY SHORT LIVED WITH THE COLD FRONT SWEEPING THROUGH LATE TOMORROW AFTERNOON SO HAVE HAVE NOT ISSUED A HEAT ADVISORY AT THIS TIME. SHOWERS AND STORMS WILL BE POSSIBLE ALONG THE FRONT TUESDAY AFTERNOON INTO EARLY TUESDAY EVENING BUT AGAIN THE CAP WILL BE A MAJOR LIMITING FACTOR. MOST OF THE FORECAST MODELS KEEP THE AREA DRY. GIVEN THE AMOUNT OF SURFACE BASED CAPE THAT DEVELOPS AHEAD OF THE FRONT OVER NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN...COULD SEE A STORM OR TWO DEVELOP ALONG THE FRONT LATE IN THE AFTERNOON SO WILL KEEP CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE LATE AFTERNOON INTO THE EARLY EVENING. VERY COMFORTABLE TEMPERATURES RETURN IN THE WAKE OF THE FRONT TUESDAY NIGHT WITH TEMPERATURES FALLING INTO THE UPPER 50S TO LOWER 60S. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 331 PM CDT MON JUL 21 2014 HIGH PRESSURE BUILDS INTO THE REGION TUESDAY NIGHT AND REMAINS OVER THE REGION THROUGH THURSDAY PROVIDING QUIET AND COMFORTABLE CONDITIONS. PLAN ON HIGHS IN THE 70S WITH LOWS IN THE 50S TO AROUND 60. WITH THE HIGH OVERHEAD WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR SOME PATCHY VALLEY FOG DURING THE LATE NIGHT AND EARLY MORNING HOURS THURSDAY MORNING...BUT CLOUD COVER COULD PREVENT THIS FROM FORMING. CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN THURSDAY NIGHT INTO THE WEEKEND AS ACTIVE NORTHWEST FLOW SETS UP ACROSS THE REGION. A TROUGH DIVES INTO THE UPPER MISSISSIPPI RIVER VALLEY ON SUNDAY AND DEEPENS A LARGER SCALE TROUGH OVER THE ENTIRE GREAT LAKES REGION EARLY NEXT WEEK. THIS WOULD SET THE STAGE FOR WELL BELOW NORMAL TEMPERATURES OVER THE AREA GOING INTO EARLY NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 627 PM CDT MON JUL 21 2014 FOCUS IS ON THUNDERSTORM POTENTIAL OVERNIGHT...WITH STORMS ALREADY DEVELOPING ACROSS THE DAKOTAS. THIS COULD FORM A LONG-LIVED COMPLEX...BUT CONFIDENCE IS GROWING THAT THIS FEATURE WILL MISS KRST/KLSE WELL TO THE NORTH. HOWEVER...SOME INCREASING MOISTURE TRANSPORT AND WARM ADVECTION COULD GENERATE ELEVATED STORMS OVERNIGHT...POSSIBLY IMPACTING KRST/KLSE AFTER MIDNIGHT. HAVE ADDED A VICINITY THUNDERSTORM GROUP FOR THIS POTENTIAL. OTHERWISE...PLAN ON SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES THROUGH IN THE LATE MORNING THROUGH AFTERNOON HOURS. WIND SHIFT TO THE NORTHWEST LOOKS TO TAKE PLACE BETWEEN 18-21Z...AND ANY STORMS WILL LIKELY DEVELOP SOUTH/EAST OF THE TAF SITES TOMORROW AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE.......ZT SHORT TERM...WETENKAMP LONG TERM....WETENKAMP AVIATION.....ZT
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
848 PM CDT MON JUL 21 2014 .UPDATE... THE MAIN QUESTION FOR TONIGHT IS WHETHER WE/LL SEE CONVECTION FIRE WEST OF MADISON LATE TONIGHT...ALONG A NORTH/SOUTH LINE AHEAD OF THE APPROACHING COLD FRONT AND WITHIN A ZONE OF STRONG H8-H7 WARM AIR ADVECTION. THE HRRR HAS BEEN GENERATING A VERY ACTIVE LINE OF CONVECTION BY 11-13Z OVER SOUTH CENTRAL AREAS...BUT IT APPEARS WITH THE NEW UPPER AIR OBS BEING INGESTED...IT IS STARTING TO BACK OFF...AND WITH GOOD REASON. THERE IS A VERY DEEP CAP FROM THE WARM AIR MASS ALREADY IN PLACE...EVEN BEFORE THE MAIN SURGE OF WARM AIR ARRIVES. THE HRRR/NAM AND THE GFS ARE THE ONLY MODELS TRYING TO FIRE OFF SOME CONVECTION WITH THE 18Z NAM THE MOST AGGRESSIVE. THE ECMWF AND THE TWO CANADIAN MODELS ARE COMPLETELY DRY TONIGHT. I PREFER THE DRIER LOOK BUT WILL KEEP SMALL CHANCES OUT WEST JUST IN CASE. THE CAP FOR TOMORROW LOOKS VERY TOUGH TO BREAK AND I/M NOT SURE WE/LL SEE MUCH THUNDERSTORM ACTION TOMORROW. THE ECMWF/GFS AND THE GEM-NH HAVE A VERY DRY LOOK...WHILE THE NAM GEM-REG AND THE HIGH RES ARW/NMM CORE MODELS FIRE OFF A NARROW LINE OF STORMS WITH THE FRONT DURING THE LATE AFTERNOON AND EVENING. THERE IS LOTS OF CAPE...BUT THE APPROACHING FRONT WILL REALLY HAVE TO DO SOME WORK TO PUNCH THROUGH THE CAP. A LOT OF CAPE MAY GO TO WASTE IF IT CAN/T INITIATE THE CONVECTION. STAY TUNED. && .AVIATION/06Z TAFS/... GENERALLY VFR THROUGH THE PERIOD...BUT WE MAY SEE SOME MVFR FOG DEVELOP TOWARD SUNRISE TUESDAY MORNING AND PERSIST FOR A FEW HOURS. LOOK FOR SOUTHWEST WINDS TO INCREASE TO 15 TO 25KTS AHEAD OF AN APPROACHING COLD FRONT. THE FRONT MAY FIRE OFF A LINE OF THUNDERSTORMS AFTER ABOUT 21-22Z TUESDAY...MOVING EAST AND EXITING THE SOUTHEAST PART OF THE STATE BY 00-02Z WEDNESDAY. THE COVERAGE IS UNCERTAIN GIVEN STRONG CAPPING IN THE ATMOSPHERE. IT/S POSSIBLE THE CAPPING WILL BE STRONG ENOUGH TO KEEP THE FRONTAL PASSAGE GENERALLY A DRY ONE AS IT MOVES ACROSS SOUTHERN WISCONSIN LATER TUESDAY AFTERNOON. && .PREV DISCUSSION... /ISSUED 400 PM CDT THU JUL 17 2014/ TONIGHT AND TUESDAY...FORECAST CONFIDENCE - MEDIUM. QUIET WEATHER IS EXPECTED FOR THIS EVENING ACROSS THE AREA...AS WARM AIR ADVECTION CONTINUES TO BRING A VERY WARM AND HUMID AIRMASS INTO THE REGION. NAM AND 4KM WRF/NMM MODELS BRINGING A SWATH OF QPF ACROSS WESTERN PORTIONS OF THE AREA LATER TONIGHT INTO EARLY TUESDAY MORNING...ASSOCIATED WITH 850 MB LOW LEVEL JET AXIS. GFS/00Z ECMWF WERE MORE SPOTTY DURING THIS TIME. THIS WILL HAVE TO BATTLE STRONG CAP THAT WILL DEVELOP DURING THIS TIME PER GFS FORECAST SOUNDINGS. NAM SOUNDINGS ARE MORE MOIST AND DOES NOT SHOW IT...THOUGH LIKELY INFLUENCED BY SOME FEEDBACK ISSUES. LEANING TOWARD THE DRIER SOLUTION...AS MAIN CONVECTION REMAINS WELL NORTHWEST AND NORTH OF THE AREA. KEPT LOWER END POPS GOING IN THE NORTHWEST HALF OF THE AREA. LOWS SHOULD REMAIN IN THE UPPER 60S TO LOWER 70S WITH RISING DEW POINTS. WINDS SHOULD BE UP ENOUGH TO LIMIT ANY FOG TO LOW LYING AREAS AT WORST. 925 MB TEMPERATURE FIELDS SUGGEST UPPER 80S TO AROUND 90 FOR HIGHS ON TUESDAY...LOWER 90S IN THE WISCONSIN RIVER VALLEY. DEW POINTS RISING INTO THE LOWER TO MID 70S WILL RESULT IN HEAT INDEX VALUES OF 95 TO 100 ACROSS MOST OF THE AREA. AFTER COORDINATION WITH NEIGHBORING OFFICES...WILL HOLD OFF ON A HEAT ADVISORY. CONDITIONS WILL BE CLOSE AND NEEDS FURTHER ANALYSIS BY NEXT SHIFTS. A SPECIAL WEATHER STATEMENT WILL HIGHLIGHT THIS FOR NOW. MODELS BRING COLD FRONT SOUTHEAST INTO THE AREA LATE TUESDAY AFTERNOON. THEY ALL HAVE SOME QPF WITH THE FRONT. HOWEVER...CAP WILL BE STRONG UNTIL LATE IN THE AFTERNOON...SO SOME UNCERTAINTY WITH HOW WIDESPREAD ANY CONVECTION WILL BE. WENT WITH CHANCE/SCATTERED POPS FOR NOW ON TUESDAY. SLIGHT RISK FOR SEVERE STORMS IN SPC DAY 2 OUTLOOK LOOKS GOOD. LARGE MEAN LAYER CAPES OF 3000 TO 4000 J/KG AND 25 TO 30 KNOTS OF DEEP LAYER SHEAR SHOULD SUPPORT MULTICELL DEVELOPMENT...WITH DAMAGING WINDS AND LARGE HAIL THE MAIN HAZARDS. TUESDAY NIGHT...FORECAST CONFIDENCE - MEDIUM. PULLED BACK POPS SLIGHTLY TO HIGH CHANCE IN THE EARLY EVENING...MOSTLY DUE TO SLIGHTLY FASTER MOVEMENT OF COLD FRONT AND SOUTHWEST LOW LEVEL WINDS. FORCING FROM LOW LEVEL JET WILLBE FARTHER EAST OVER THE CENTRAL GTLAKES BY 00Z. HENCE EXPECT LESS OVERALL COVERAGE OF CONVECTION. NEVER THE LESS...SLIGHT RISK STILL VALID AS BULK SHEAR OF 35 TO 40KTS LIKELY WITH HIGH CAPE VALUES EXCEEDING 3000 J/KG. SLIGHT COOLING OF MID-LEVEL HEIGHTS WILL ERODE CAPPING INVERSION IN THE LATE AFTN WHICH WILL HELP REALIZE STRONG INSTABILITY ALONG FRONT. HENCE EXPECT SCT CONVECTION WITH THE POTENTIAL FOR LARGE HAIL AND DAMAGING WINDS. CDFNT MOVES THROUGH DURING THE EVENING ENDING THUNDERSTORMS BY LATE EVENING WITH COOLER AND DRIER AIR SETTLING IN LATE IN THE NIGHT. WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDENCE - HIGH. A QUIET PERIOD AS NORTHWEST LOW LEVEL WINDS AND UPSTREAM RIDGING HOLD SWAY THROUGH THE PERIOD. MAY BE SOME PATCHY FOG LATER WEDNESDAY NIGHT. THURSDAY NIGHT THROUGH MONDAY - FORECAST CONFIDENCE - MEDIUM TRENDING TOWARD LOW. LARGE UPSTREAM HIGH PRESSURE RIDGE CONTINUES TO PINCH OFF DEEPER MOISTURE WELL TO THE SOUTH AND WEST OF THE AREA THROUGH THURSDAY NIGHT. UPSTREAM RIDGE BEGINS TO FLATTEN ON FRIDAY AS LOW PRESSURE MOVES ACROSS SOUTHERN CANADA WITH WEAKER TROF EXTENDING SWD. INCREASING SOUTHERLY WINDS THEN USHER WARMER...MORE HUMID AIR INTO THE REGION FRIDAY NIGHT AND SATURDAY AHEAD OF APPROACHING TROUGH. HOWEVER BOTH GFS AND ECMWF SHOW STRONGEST LOW LEVEL FORCING AND ADVECTION REMAINING SOUTH OF WI DURING THIS PERIOD VCNTY OF SFC WMFNT. FOR NOW WL CONTINUE CHANCE POPS FRI NGT AND SAT. CONFIDENCE FOR LATER PERIODS TRENDS DOWNWARD. GFS CARRIES UPPER LOW OVER SRN CANADA SLOWLY SOUTHEAST ACROSS WRN GTLAKES LATER IN THE WEEKEND AS IT PHASES WITH LONG WAVE TROUGH NEAR HUDSON BAY. ECMWF HAD BEEN SHOWING THIS SCENARIO WITH EARLIER RUNS BUT HAS NOW TRENDED TOWARD FLATTER NW STEERING FLOW SETTING UP OVER WI INTO EARLY NEXT WEEK WITH MUCH WEAKER LOW PRESSURE TROUGH LINGERING OVER CENTRAL GTLAKES. MAY NEED TO CARRY SOME LOW POPS IN ERN CWA IN LATER PERIODS DUE TO PROXIMITY OF THIS TROUGH. AFTER TUESDAY...THE HEAT AND HUMIDITY SHOULD REMAIN WELL SOUTH OF THE AREA WITH TEMPERATURES AVERAGING NEAR OR SLIGHTLY BELOW NORMAL FOR LATE JULY. AVIATION/00Z TAFS/... VFR CONDITIONS ARE EXPECTED FOR MOST OF TONIGHT AND TUESDAY. SOUTH TO SOUTHWEST WINDS WILL CONTINUE TO BRING WARM AND HUMID CONDITIONS INTO THE AREA DURING THIS TIME. MOST LINGERING DIURNAL CUMULUS SHOULD LINGER UNTIL AROUND SUNSET. SOUTH WINDS MAY WEAKEN ENOUGH BETWEEN 09Z AND 13Z TUESDAY TO ALLOW FOR MVFR FOG TO DEVELOP AT KENOSHA AND PERHAPS MADISON AND WAUKESHA. UNCERTAIN WITH THIS...SO ONLY KEPT VFR FOG IN KENOSHA TAF FOR NOW. GUSTY SOUTH TO SOUTHWEST WINDS SHOULD DEVELOP TUESDAY...WITH GUSTS TO AROUND 20 KNOTS AT TIMES. OUTSIDE CHANCE FOR SHOWERS OR STORMS LATE TONIGHT INTO EARLY TUESDAY MORNING AT MADISON...BUT LEFT OUT OF TAFS DUE TO LOW CONFIDENCE IN IT HAPPENING. COLD FRONT WITH SCATTERED THUNDERSTORMS SHOULD MOVE SOUTHEAST THROUGH TAF SITES BETWEEN 22Z TUESDAY AND 06Z WEDNESDAY. MAY SEE GUSTY WINDS AND HAIL WITH ANY STORMS...ALONG WITH IFR VISIBILITIES. USED VICINITY THUNDER WORDING IN MILWAUKEE TAF FOR NOW. MARINE... SOUTH WINDS OF 15 TO 20 KNOTS ARE EXPECTED THIS AFTERNOON NORTH OF PORT WASHINGTON. A FEW GUSTS TO 22 KNOTS ARE EXPECTED...BUT NOT FREQUENT ENOUGH FOR A SMALL CRAFT ADVISORY. WAVES SHOULD BUILD TO 2 TO 4 FEET BY LATE AFTERNOON...THEN SUBSIDE TONIGHT WITH WEAKENING WINDS. MAY SEE FOG DEVELOP TONIGHT AND LINGER TUESDAY...WITH DEW POINTS INCREASING ACROSS THE AREA. DENSE FOG MAY AN ISSUE...THOUGH NOT CONVINCED YET GIVEN THE WINDS REMAINING AT LEAST IN THE 5 TO 10 KNOT RANGE OVERNIGHT...MAINLY HIGHER. WILL CONTINUE TO MENTION IN HAZARDOUS WEATHER OUTLOOK. SMALL CRAFT ADVISORY IN EFFECT FOR TUESDAY INTO EARLY TUESDAY EVENING FOR GUSTY SOUTH TO SOUTHWEST WINDS AND SOME HIGH WAVES. TIGHT PRESSURE GRADIENT AHEAD OF COLD FRONT WILL LEAD TO THE GUSTY WINDS. ANOTHER SMALL CRAFT ADVISORY WILL BE NEEDED FOR LATER TUESDAY NIGHT INTO WEDNESDAY NIGHT...AS A TIGHT PRESSURE GRADIENT DEVELOPS OVER THE AREA. HIGH WAVES WILL OCCUR AS WELL DURING THIS TIME. BEACHES... MODERATE SWIM RISK WILL CONTINUE UNTIL EARLY EVENING AT SHEBOYGAN COUNTY BEACHES DUE TO GUSTY WINDS AND WAVES. SHOULD SEE HIGH SWIM RISK WEDNESDAY INTO WEDNESDAY NIGHT WITH GUSTY NORTH TO NORTHEAST WINDS AND HIGH WAVES. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 10 AM TO 9 PM CDT TUESDAY FOR LMZ643>646. && $$ UPDATE...DAVIS TONIGHT/TUESDAY AND AVIATION/MARINE...WOOD TUESDAY NIGHT THROUGH MONDAY...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
627 PM CDT MON JUL 21 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 331 PM CDT MON JUL 21 2014 MAIN FORECAST CONCERNS ARE SEVERE THUNDERSTORM POTENTIAL LATE TONIGHT OVER NORTH CENTRAL WISCONSIN AND HEAT INDEX VALUES LATE TUESDAY MORNING INTO TUESDAY AFTERNOON OVER PORTIONS OF NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN. LATEST RADAR IMAGERY SHOWS THUNDERSTORMS DEVELOPING OVER PORTIONS OF CENTRAL NORTH DAKOTA. THESE SHOULD BE THE BIRTH OF A THUNDERSTORM COMPLEX THAT WILL RACE EAST TONIGHT ACROSS NORTHERN MINNESOTA INTO PORTIONS OF NORTHERN WISCONSIN AND UPPER MICHIGAN. MOST OF THE MESOSCALE MODEL GUIDANCE KEEPS THIS COMPLEX NORTH OF THE INTERSTATE 94 CORRIDOR. HOWEVER...THE NAM...WHICH IS A MAJOR OUTLIER AT THIS TIME...SHOWS CONVECTION FIRING OVER WEST CENTRAL MINNESOTA LATE THIS AFTERNOON INTO THIS EVENING THEN THIS CONVECTION RACES SOUTHEAST INTO THE FORECAST AREA. LOOKING AT FORECAST SOUNDINGS OVER MUCH OF THE FORECAST AREA THERE IS AN IMPRESSIVE ELEVATED MIXED LAYER WHICH IS RESULTING IN A STRONG CAP IN PLACE. THE CONVECTION WILL HAVE TO OVERCOME THIS CAP AND WITHOUT A STRONG LOW LEVEL JET THIS WILL BE DIFFICULT TO DO. THE 17Z HRRR SHOWS A FEW CELLS MAKING IN INTO WEST CENTRAL WISCONSIN AFTER MIDNIGHT SO WILL HAVE TO SEE IF THIS PANS OUT. HAVE DECIDED TO REDUCE POPS ACROSS MUCH OF THE FORECAST AREA TONIGHT WITH THE EXCEPTION OF CLARK AND TAYLOR COUNTY WHERE THE MCS COULD IMPACT THESE AREAS WITH DAMAGING WINDS THE MAY CONCERN. A COLD FRONT THEN SAGS SOUTH ACROSS THE AREA ON TUESDAY. SOME OF THE WARMEST AIR AT 925 MB MAKES IT INTO NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN WHERE 925 MB TEMPERATURES CLIMB TO AROUND 27 C. TEMPERATURES COULD CLIMB TO THE UPPER 80S TO AROUND 90 OVER PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THESE TEMPERATURES COMBINED WITH DEWPOINTS IN THE MID TO UPPER 70S WILL PRODUCE HEAT INDEX VALUES AROUND 100. THIS HEAT LOOKS TO BE VERY SHORT LIVED WITH THE COLD FRONT SWEEPING THROUGH LATE TOMORROW AFTERNOON SO HAVE HAVE NOT ISSUED A HEAT ADVISORY AT THIS TIME. SHOWERS AND STORMS WILL BE POSSIBLE ALONG THE FRONT TUESDAY AFTERNOON INTO EARLY TUESDAY EVENING BUT AGAIN THE CAP WILL BE A MAJOR LIMITING FACTOR. MOST OF THE FORECAST MODELS KEEP THE AREA DRY. GIVEN THE AMOUNT OF SURFACE BASED CAPE THAT DEVELOPS AHEAD OF THE FRONT OVER NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN...COULD SEE A STORM OR TWO DEVELOP ALONG THE FRONT LATE IN THE AFTERNOON SO WILL KEEP CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE LATE AFTERNOON INTO THE EARLY EVENING. VERY COMFORTABLE TEMPERATURES RETURN IN THE WAKE OF THE FRONT TUESDAY NIGHT WITH TEMPERATURES FALLING INTO THE UPPER 50S TO LOWER 60S. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 331 PM CDT MON JUL 21 2014 HIGH PRESSURE BUILDS INTO THE REGION TUESDAY NIGHT AND REMAINS OVER THE REGION THROUGH THURSDAY PROVIDING QUIET AND COMFORTABLE CONDITIONS. PLAN ON HIGHS IN THE 70S WITH LOWS IN THE 50S TO AROUND 60. WITH THE HIGH OVERHEAD WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR SOME PATCHY VALLEY FOG DURING THE LATE NIGHT AND EARLY MORNING HOURS THURSDAY MORNING...BUT CLOUD COVER COULD PREVENT THIS FROM FORMING. CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN THURSDAY NIGHT INTO THE WEEKEND AS ACTIVE NORTHWEST FLOW SETS UP ACROSS THE REGION. A TROUGH DIVES INTO THE UPPER MISSISSIPPI RIVER VALLEY ON SUNDAY AND DEEPENS A LARGER SCALE TROUGH OVER THE ENTIRE GREAT LAKES REGION EARLY NEXT WEEK. THIS WOULD SET THE STAGE FOR WELL BELOW NORMAL TEMPERATURES OVER THE AREA GOING INTO EARLY NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 627 PM CDT MON JUL 21 2014 FOCUS IS ON THUNDERSTORM POTENTIAL OVERNIGHT...WITH STORMS ALREADY DEVELOPING ACROSS THE DAKOTAS. THIS COULD FORM A LONG-LIVED COMPLEX...BUT CONFIDENCE IS GROWING THAT THIS FEATURE WILL MISS KRST/KLSE WELL TO THE NORTH. HOWEVER...SOME INCREASING MOISTURE TRANSPORT AND WARM ADVECTION COULD GENERATE ELEVATED STORMS OVERNIGHT...POSSIBLY IMPACTING KRST/KLSE AFTER MIDNIGHT. HAVE ADDED A VICINITY THUNDERSTORM GROUP FOR THIS POTENTIAL. OTHERWISE...PLAN ON SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES THROUGH IN THE LATE MORNING THROUGH AFTERNOON HOURS. WIND SHIFT TO THE NORTHWEST LOOKS TO TAKE PLACE BETWEEN 18-21Z...AND ANY STORMS WILL LIKELY DEVELOP SOUTH/EAST OF THE TAF SITES TOMORROW AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR MNZ079-086-087-094- 095. IA...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR IAZ008-009-018-019. && $$ SHORT TERM...WETENKAMP LONG TERM....WETENKAMP AVIATION.....ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1143 PM CDT SAT JUL 19 2014 .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 307 PM CDT SAT JUL 19 2014 CURRENTLY WATCHING A MID-LEVEL SHORTWAVE TROUGH MOVING ACROSS NW WI THROUGH SCNTL MN. THERE WAS A SCATTERED LINE OF SHOWER/THUNDERSTORMS AHEAD OF THE WAVE THROUGH THE MORNING BUT THESE HAVE BEEN DIMINISHING THROUGH EARLY THIS AFTERNOON AS 850MB MOISTURE TRANSPORT WANES... PER THE RAP ANALYSIS. OTHERWISE...SCATTERED TO BROKEN CUMULUS AND ALTOCUMULUS CLOUD WAS PRESENT ACROSS THE AREA WITH TEMPERATURES GENERALLY IN THE 75 TO 80 DEGREE RANGE. FOR TONIGHT...A SHORTWAVE RIDGE MOVES ACROSS THE REGION BEHIND THE DEPARTING TROUGH FOR PARTLY CLOUDY SKIES AND OVERNIGHT LOW READINGS IN THE LOWER/MIDDLE 60S. FOR SUNDAY...WILL SEE SURFACE CYCLOGENESIS OVER THE HIGH PLAINS WITH A WARM FRONT LIFTING NORTHWARD TOWARD THE AREA FROM THE PLAINS. STRENGTHENING SOUTHERLY FLOW TAKES BETTER AXIS OF 850MB MOISTURE TRANSPORT ACROSS/OVER THE WARM FRONT INTO WESTERN/NORTHERN MN...SO THINKING ANY SHOWER THUNDERSTORM CHANCES SHOULD BE CONFINED ACROSS THAT AREA LEAVING US PRECIPITATION FREE WITH TEMPERATURES AGAIN TOPPING OFF IN THE 80-85 DEGREE RANGE. WILL FEEL A TAD MORE HUMID THOUGH AS DEW POINTS CREEP UPWARD THROUGH THE 60S. THUNDERSTORM CHANCES LOOK TO BE ON THE INCREASE ACROSS OUR AREA SUNDAY NIGHT AS THE SURFACE WARM FRONT LIFTS INTO SOUTHERN MN/CENTRAL WI. ECMWF HAS SHOWN BEST RUN-TO-RUN CONSISTENT MCS SIGNAL AS 850MB MOISTURE TRANSPORT TAKES AIM INTO OUR AREA. QUESTION REMAINS ON WHERE EXACTLY THIS MCS WILL TRACK. LATEST 19.12Z RUN TAKES THE MCS FROM NORTHERN MN INTO NORTHERN WISCONSIN IN THE 06-12Z TIME FRAME. NAM/GFS SHOWING SOME RESPONSE/QPF-WISE...BUT NOT AS INTENSE. ECMWF SHOWS 0-3KM MUCAPE 1000-2000J/KG...MAINLY ABOVE 850MB WITH WEAK EFFECTIVE BULK SHEAR. AT THE SAME TIME... PRECIPITABLE WATER VALUES INCREASE TO NEAR 1.8 INCHES. SO...COULD SEE THE POTENTIAL FOR SOME HEAVY RAINFALL OUT OF THIS SYSTEM. WILL HAVE TO WATCH HOW THIS EVOLVES GIVEN FORWARD MOVING CORFIDI VECTORS WOULD TAKE THE MCS MORE INTO OUR AREA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 307 PM CDT SAT JUL 19 2014 A FEW LINGER SHOWERS AND THUNDERSTORMS MAY BE SEEN MONDAY MORNING...BUT THE ATTENTION TURNS TO INCREASING HEAT AS THE WARM FRONT LIFTS NORTH OF THE AREA AND UPPER RIDGE BUILDS. LOOKING FOR HIGH TEMPERATURE READINGS IN THE 85-90 DEGREE RANGE WITH DEW POINTS RISING INTO THE 70S. THIS WILL PRODUCE HEAT INDICES IN THE 95-100 DEGREE RANGE...ESPECIALLY ACROSS PORTIONS OF SOUTHEAST MN/WEST CENTRAL WI. WILL HAVE TO KEEP AN EYE ON THIS FOR POSSIBLE HEAT HEADLINES. LATE MONDAY NIGHT INTO TUESDAY SHOWING THE POTENTIAL FOR SOME SEVERE WEATHER AS AN AREA OF LOW PRESSURE AND A COLD FRONT TRACK ACROSS THE AREA. ECMWF SHOWS 0-3KM MUCAPE INCREASING INTO THE 1500-3000J/KG RANGE WITH 0-3KM BULK SHEAR IN THE 25-35KT RANGE. WILL HAVE TO KEEP A CLOSE WATCH ON THIS SCENARIO FOR SEVERE POTENTIAL. SHOWER AND THUNDERSTORM CHANCES WILL LINGER INTO TUESDAY NIGHT/MAINLY EVENING AS THE COLD FRONT PUSHES OUT OF THE AREA. CANADIAN HIGH PRESSURE BUILDS INTO THE AREA ON WEDNESDAY THROUGH THURSDAY FOR COOLER/DRIER CONDITIONS. LOOK FOR HIGHS LOWERING INTO THE MID/UPPER 70S. SHOWER AND THUNDERSTORM CHANCES SPREAD BACK INTO THE REGION FRIDAY INTO THE WEEKEND AS BOTH THE ECMWF/GFS SHOW A CLOSED LOW MOVING INTO THE UPPER MISSISSIPPI REGION. LOOKS LIKE COOLER THAN NORMAL TEMPERATURE WILL ALSO RESULT WITH HIGHS IN THE 70S TO NEAR 80. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1143 PM CDT SAT JUL 19 2014 VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THROUGH SUNDAY EVENING AS THE AREA REMAINS IN SOUTH-SOUTHWESTERLY FLOW IN THE LOW LEVELS. SOME MID LEVEL CLOUD COVER HAS DEVELOPED ACROSS NORTHERN IOWA THROUGH SOUTHEAST MINNESOTA AND WESTERN WISCONSIN AND SHOULD LINGER INTO THE MORNING HOURS. CLOUD BASES ARE MAINLY IN THE 3500-7000FT RANGE AND SHOULD STAY THERE THROUGH THE EARLY MORNING HOURS. SCT-BKN VFR CEILINGS SHOULD PERSIST THROUGH MUCH OF THE DAY WITH WINDS PICKING UP OUT OF THE SOUTH AND BECOMING GUSTY BY LATE MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM....DAS AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS TUCSON AZ
910 PM MST MON JUL 21 2014 .SYNOPSIS...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS MOSTLY EAST AND SOUTH OF TUCSON THROUGH THE MIDDLE OF THIS WEEK. MUCH HOTTER TEMPERATURES WILL OCCUR TUESDAY THROUGH THURSDAY...WITH NEAR RECORD HIGHS POSSIBLE. AN INCREASE IN THUNDERSTORM ACTIVITY SHOULD OCCUR LATE IN THE WEEK AND INTO THE WEEKEND. && .DISCUSSION...AFTER A VERY QUIET JULY DAY...04Z IR IMAGERY WAS SHOWING SCT-BKN SKIES OVER MUCH OF COCHISE...GREENLEE...GRAHAM...AND SANTA CRUZ COUNTIES THIS EVENING. THE COOLEST CLOUD TOPS WERE IN EXTREME SERN COCHISE COUNTY IN THE VICINITY OF KDUG IN THE FORM OF SOME REMNANT DEBRIS CLOUDS FROM EARLIER THUNDERSTORM ACTIVITY IN NRN SONORA MEXICO. AREA TEMPS GENERALLY RANGED FROM THE UPPER 70S IN SOME OF THE HIGHER ELEVATIONS TO THE MID 90S IN THE WESTERN DESERTS OF PIMA COUNTY...WITH SFC DEWPOINTS MAINLY IN THE 30S AND 40S EXCEPT NEAR THE INTERNATIONAL BORDER WHERE A FEW SPOTS WERE A BIT MORE MOIST. LATEST RUN OF THE HRRR WAS TRYING FOR SOME LIGHT PRECIP OVER SERN COCHISE CNTY BETWEEN 05Z AND 09Z TONIGHT...LIKELY HITTING ON THE THICKER CLOUD COVER AND HIGHER DEWPOINTS. THE TWO LOCAL WRF MODELS REMAINED DRY FOR THAT PERIOD. AS SUCH...HAVE CHOSEN TO LEAVE IN ONLY SINGLE DIGIT POPS FOR THAT AREA...AS WE ARE LIKELY TOO STABLE FOR ANY PRECIP TO OCCUR. FOLLOWING LATEST SATELLITE TRENDS...AREAS TO THE SOUTH AND EAST OF TUCSON WILL LIKELY SEE THE GREATEST PERCENTAGE OF CLOUD COVER OVERNIGHT TONIGHT...WITH WRN PORTIONS FILLING IN WITH SOME MID AND HIGH LVL CLOUDS AS WE CLOSE IN ON DAYBREAK. THE REST OF THE FORECAST IS ON TRACK...SO NO FURTHER UPDATES ARE NEEDED. FOR MORE INFORMATION...PLEASE SEE THE PREVIOUS DISCUSSION BELOW. && .AVIATION...VALID THRU 23/06Z. ISOLATED -TSRA/-SHRA WILL OCCUR MOSTLY EAST AND SOUTH OF KTUS TUESDAY AFTERNOON AND TUESDAY EVENING. BRIEF WIND GUSTS TO NEAR 35 KTS MAY OCCUR WITH THIS ACTIVITY. OTHERWISE...EXPECT MOSTLY CLEAR SKIES WEST OF KTUS AND A FEW TO BROKEN CLOUDS MAINLY ABOVE 10K FT AGL EAST TO SOUTH OF KTUS THROUGH TUESDAY EVENING. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...THUNDERSTORM ACTIVITY WILL INCREASE ACROSS SOUTHEAST ARIZONA STARTING TUESDAY...THEN SCATTERED MOSTLY AFTERNOON AND EVENING THUNDERSTORMS WILL PREVAIL BY THIS WEEKEND. EXPECT STRONG... GUSTY AND ERRATIC WINDS WITH THE STRONGER THUNDERSTORMS. HOTTER TEMPERATURES WILL ALSO OCCUR TUESDAY THROUGH THURSDAY FOLLOWED BY A COOLING TREND BY THE WEEKEND. && .PREV DISCUSSION...TUESDAY SHOULD SEE A SLIGHT UPTICK IN THUNDERSTORM CHANCES AS THE HIGH SHIFTS TO A POSITION OVER WESTERN COLORADO AND PWATS ARE EXPECTED TO INCREASE TO AROUND 1.3 - 1.4 INCHES. BY WEDNESDAY THE HIGH WILL BE OVER EASTERN COLORADO AND WESTERN KANSAS WITH THE RIDGE AXIS NOSING INTO THE DESERT SOUTHWEST...RESULTING IN SIGNIFICANTLY WARMER TEMPERATURES. PWATS WILL CONTINUE IN THE 1.2 - 1.6 INCH RANGE FROM TUCSON TOWARD AJO...WITH LOWER VALUES ALONG THE NEW MEXICO BORDER. GIVEN THAT...EXPECT AN EVEN BETTER CHANCE WEDNESDAY AFTERNOON FOR MOST AREAS...EXCEPT FOR AREAS ALONG THE IMMEDIATE BORDER WITH NEW MEXICO. BY THURSDAY ANOTHER DOWN SWING IN ACTIVITY IS EXPECTED AS THE HIGH BECOMES CENTERED OVER EASTERN ARIZONA AND MUCH OF NEW MEXICO...AND DRIER PWATS MOVE IN FROM THE EAST...WITH READINGS BELOW THE 1 INCH MARK FROM TUCSON EASTWARD. BY FRIDAY...BUT ESPECIALLY THIS WEEKEND...WE SHOULD SEE A FAIRLY SIGNIFICANT INCREASE IN THUNDERSTORM ACTIVITY AS AN UPPER LEVEL DISTURBANCE OVER NORTHERN MEXICO MOVES NORTHWEST ACROSS PARTS OF SONORA...SOUTHERN ARIZONA AND NORTHERN BAJA...AND THE HIGH BECOMES ORIENTED FROM SRN UTAH ACROSS NORTHEAST ARIZONA AND INTO NORTHERN NEW MEXICO. THIS SETUP WILL GIVE ARIZONA A FAIRLY LONG EAST TO SOUTHEASTERLY FETCH FOR ADDITIONAL MOISTURE TO SPILL INTO THE REGION. THE HIGH TRANSITIONS OVER THE AZ/NM BORDER MONDAY FOR A DECREASE IN ACTIVITY. HIGH TEMPERATURES ABOVE NORMAL THROUGHOUT THE FORECAST PERIOD...BUT THE WARMEST DAYS WILL OCCUR WEDNESDAY THROUGH FRIDAY...WHEN READINGS WILL BE 8 TO 12 DEGS ABOVE NORMAL. OTHERWISE...EXPECT HIGHS TO BE 3 TO 6 DEGS ABOVE NORMAL. LOWS GENERALLY 4 TO 6 DEGS ABOVE NORMAL EACH DAY...BUT THE WARMEST MORNINGS SHOULD OCCUR WEDNESDAY THROUGH FRIDAY. .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON DISCUSSION...FRENCH PREV DISCUSSION...MOLLERE AVIATION/FIRE WEATHER...FRANCIS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1132 PM MDT MON JUL 21 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 328 PM MDT MON JUL 21 2014 REMNANT MONSOON MOISTURE PLUME EXTENDS ACROSS CENTRAL AND SOUTHEAST COLORADO WITH WEAK SHORTWAVE ACROSS SOUTHEAST CO EXPECTED TO LIFT TO THE NORTHEAST THIS AFTERNOON WITHIN THE UPPER HIGH. SO FAR...CLOUDS HAVE BEEN HOLDING DOWN THE HEATING...WHICH HAS KEPT TEMPERATURES FROM HITTING 100 ALONG THE I-25 CORRIDOR AND ADJACENT PLAINS. FARTHER EAST A BIT MORE SUN WILL LIKELY ALLOW TEMPERATURES TO HIT LOWER 100S OUT TOWARDS LAA. INSTABILITY STILL LOOKS BEST THIS AFTERNOON TO THE EAST OF A LINE FROM EADS TO LAS ANIMAS TO KIM. IF DEW POINTS CAN STAY IN THE LOWER 50S...THEN 1500 J/KG (OR A LITTLE BETTER) OF CAPE WILL REMAIN IN PLACE ACROSS THE FAR SOUTHEAST PLAINS. WEAK FLOW WITHIN THE UPPER RIDGE WILL KEEP DEEP LAYER SHEARS ON THE WEAK SIDE FOR MOST OF THE AREA...WHICH SHOULD LIMIT STORM ORGANIZATION. BUT WITH DOWNDRAFT CAPES OF 1500+ J/KG...GUSTY OUT FLOW WINDS TO AROUND 60 MPH...AND HAIL NEAR 1 INCH IN DIAMETER WILL BE POSSIBLE WITH STORMS IN THIS AREA. ELSEWHERE...GUSTY WINDS AND LIGHTNING LOOK TO BE THE MAIN THREAT. ATMOSPHERE DOES NOT LOOK VERY CONDUCIVE FOR FLASH FLOODING ON AREA BURN SCARS TODAY...BUT FOR THE WALDO IT DOESN`T TAKE MUCH TO CAUSE PROBLEMS...SO THIS AREA WILL BE MONITORED CLOSELY. LATEST HRRR SUGGESTS WALDO WILL BE MISSED TODAY. FRONT DROPS THROUGH THE PLAINS EARLY TUESDAY MORNING AND MONSOON PLUME APPEARS TO GET SHUNTED OFF TO THE SOUTH...THOUGH AT LEAST SOME RESIDUAL MOISTURE WILL REMAIN IN PLACE. MOISTURE RETURN BEHIND THE FRONT LOOKS MEAGER...SO OVERALL...IT LOOKS LIKE ANOTHER DAY OF MAINLY ISOLATED THUNDERSTORMS. IF DEW POINTS CAN INCREASE INTO THE LOWER TO MID 50S AS NAM12 SUGGESTS...WE COULD SEE ANOTHER STRONG TO MARGINALLY SEVERE THUNDERSTORM DAY ACROSS THE FAR SOUTHEAST PLAINS AGAIN. HAVING A HARD TIME BUYING THE 100+ TEMPERATURES ADVERTISED BY GUIDANCE FOR PUB. SOME LOWER 100S OUT ON THE FAR SOUTHEAST PLAINS LOOK REASONABLE...BUT KEPT TEMPERATURES A TAD LOWER FOR PUB AS GUIDANCE HAS BEEN RUNNING TOO HOT LATELY AND EASTERLY WINDS DON`T USUALLY BODE FOR SUCH WARM TEMPERATURES. AS FOR FLASH FLOOD THREAT ON THE BURN SCARS...THIS STILL LOOKS RATHER LOW AT THIS POINT. -KT .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 328 PM MDT MON JUL 21 2014 TUESDAY NIGHT-WEDNESDAY NIGHT...A BROAD...HOT (600DM) UPPER HIGH CONTINUES TO BUILD ACROSS THE STATE WITH THE MAIN MONSOONAL MOISTURE PLUME BEING SHUNTED INTO THE DESERT SW THROUGH THE GREAT BASIN AND WESTERN COLORADO...AS FLOW ALOFT BECOMES MORE SOUTH TO SOUTHEAST ACROSS THE AREA. CONVECTION TO BE ON THE WANE TUESDAY EVENING WITH GFS LIKELY OVERDONE IN ITS QPF FIELD...THOUGH HAVE KEPT SOME ISOLATED POPS ACROSS THE SW AND CENTRAL MTS THROUGH THE OVERNIGHT HOURS. A WEAK BACKDOOR COLD FRONT MOVES ACROSS EASTERN COLORADO EARLY WEDNESDAY MORNING WITH BREEZY EAST TO SOUTHEAST LOW LEVEL UPSLOPE STRENGTHENING THROUGH THE AFTERNOON ACROSS THE PLAINS. WITH ENOUGH MOISTURE UNDERNEATH THE HIGH...ALONG WITH A POSSIBLE WEAK DISTURBANCE MOVING THROUGH THE SOUTHERLY FLOW ALOFT ACROSS THE EASTERN GREAT BASIN...SHOULD SEE SCATTERED AFTERNOON AND EVENING STORMS OVER AND NEAR THE HIGHER TERRAIN...WITH THE BEST COVERAGE ACROSS THE SW AND CENTRAL MTS. LOCALLY HEAVY RAINFALL REMAINS POSSIBLE...ESPECIALLY ACROSS WESTERN COLORADO...WITH MODEL SOUNDINGS INDICATING CAP TO HOLD ACROSS THE PLAINS THROUGH THE AFTERNOON THOUGH HAVE KEPT SLIGHT POPS IN PLACE INTO THE EVENING HOURS. WITH MORE CONVECTIVE CLOUD COVER AND DEVELOPING UPSLOPE FLOW...HIGH TEMPERATURES TO BE A TAD COOLER ON WEDNESDAY ACROSS THE AREA DESPITE THE UPPER RIDGING IN PLACE. THURSDAY-FRIDAY...UPPER HIGH PROGGED TO SLOWLY RETROGRADE SOUTH AND WEST INTO THE FOUR CORNERS REGION WITH SOME RESIDUAL MOISTURE REMAINING WITHIN THE DEVELOPING WESTERLY FLOW ALOFT ACROSS THE STATE. SHOULD CONTINUE TO SEE SCATTERED DIURNAL CONVECTION ACROSS THE HIGH TERRAIN ON THURSDAY WITH A FEW STORMS MOVING ACROSS THE PLAINS THROUGH THE EVENING HOURS...WITH ANOTHER WEAK BACKDOOR FRONT MOVING ACROSS THE AREA. MUCH OF THE SAME EXPECTED ON FRIDAY...WITH SLIGHTLY BETTER COVERAGE ACROSS THE EASTERN PLAINS WITH LOW LEVEL UPSLOPE FLOW. TEMPERATURES TO BE AT OR ABOVE NORMAL THROUGH THE PERIOD. SATURDAY-MONDAY...UPPER HIGH CONTINUES TO BUILD NORTH AND WEST ACROSS THE GREAT BASIN WITH BROAD NORTHWEST DEVELOPING ACROSS THE STATE AS AN UPPER TROUGH CARVES OUT ACROSS THE CENTRAL CONUS. THIS PATTERN LOOKS TO DRY OUT THE UPPER LEVELS OF THE ATMOSPHERE WITH OCCASIONAL SHORT WAVES AND ASSOCIATED FRONTS MOVING ACROSS THE NORTHERN AND CENTRAL HIGH PLAINS KEEPING AMPLE LOW LEVEL MOISTURE IN PLACE ACROSS EASTERN COLORADO. WITH THAT SAID...SHOULD CONTINUE TO SEE DAILY CHANCES OF SHOWERS AND THUNDERSTORMS...WITH INCREASING CONCERNS FOR SEVERE WEATHER AND LOCALLY HEAVY RAINFALL ACROSS EASTERN COLORADO. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1125 PM MDT MON JUL 21 2014 VFR CONDITIONS ALL TERMINALS TONIGHT AND THROUGH 18Z TUE WITH LIGHT WINDS. TUE AFTERNOON...TSRA WILL AGAIN DEVELOP OVER THE MOUNTAINS AND SPREAD ACROSS THE LOWER ELEVATIONS LATE IN THE DAY. INCLUDED A VCTS MENTION AT KALS FOR A FEW HRS LATE AFTERNOON INTO THE EVENING...WITH GUSTY WINDS THE MAIN THREAT NEAR ANY STORMS. FOR KCOS...WEAK SURFACE BOUNDARY WILL PUSH THROUGH THE AREA DURING THE LATE AFTERNOON...POSSIBLY SERVING AS THE FOCUS FOR A FEW STORMS AWAY FROM THE MOUNTAINS LATE...MAINLY 22Z-03Z PERIOD...SO INCLUDED A VCTS MENTION HERE AS WELL. AGAIN...GUSTY WINDS THE MAIN STORM THREAT. LEFT VCTS OUT OF KPUB ANS BEST LIFT MAY STAY NORTH OF THE AIRPORT...THOUGH CONVECTION ALONG PLAINS SURFACE BOUNDARY WILL NEED TO BE WATCHED AS OUTFLOW WINDS COULD HELP DEVELOP AN ISOLATED TSRA FARTHER SOUTH AFTER 00Z. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KT LONG TERM...MW AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
216 AM EDT Tue Jul 22 2014 .Near Term [Through Tonight]... The 11 pm EDT regional surface analysis showed a decaying, wavy, quasi-stationary, front from SC, through central GA, extending southwestward to a broad, 1015 mb low centered over southern MS. There was an east-west trough along I-10 in the FL Panhandle. Vapor imagery and upper air data showed a cutoff low centered over southwest GA, with a well-defined dry slot wrapping around the west and southwest flank of the low, over the FL Panhandle and adjacent coastal waters. The GFS and ECMWF forecast the upper low to translate slowly westward, providing weak Q-G forcing across GA & AL today. It also appears that there will be slightly more deep layer moisture in this region as well. Although they differ somewhat in magnitude, the consensus of MOS and the Convection Allowing Models (ECAM) PoPs generally range from 40 to 60% across our forecast area today. The most concentrated area of deep moist convection will initially be across Apalachee Bay and the FL Big Bend/North FL this morning. This activity will gradually move inland and diminish later this morning, but scattered storms will develop across GA and AL this afternoon in association with the forcing from the upper low and any mesoscale boundary interactions that occur. Given the very weak wind field aloft and lackluster forecast SBCAPE values (1500 J/kg or less), we`re expecting a less than 5% chance of severe storms (within 25 miles of a point) today. We expect high temperatures to be a little warmer today than in recent days- around 90. .Short Term [Wednesday Through Thursday Night]... A mid-upper level low will continue to retrograde westward along the Gulf coast and eventually get sheared out near coastal Louisiana or Texas by Thursday. For Wednesday, this will allow for a ridge to build into the area with negative vorticity advection in those same layers. Computer models are in good agreement in showing suppressed convective activity on Wednesday despite PWATs very close to seasonal normals (around 1.9"). While this may be the case, we think that the approx 20% PoPs the models are advertising for the afternoon hours are too low without any substantial drying - either at the surface or aloft. By Thursday, another trough begins to dig into the region from the northwest and could provide some additional large scale forcing for storms. Therefore, we indicated scattered thunderstorms both afternoons with PoPs around 30-40% in most areas. Temperatures should be warmer than in recent days, with highs in the mid 90s likely. .Long Term [Friday Through Tuesday]... The large scale pattern commences rather amplified with ridging over west, troughing over east and ridge over extreme Wrn Atlc. At surface, ridge from Wrn Atlc to over local region with cold front draped over mid-south. During the rest of the period, Wrn ridge shifts Ewd with downstream trough pivoting and deepening Ewd over local region on Fri before lifting Newd and flattening Sat into Sun. Front inches swd shunting Gulf ridge further Swd allowing for a return to a more WLY flow and normal summer time sea breeze dominated regime. Will go with generally 30-40% aftn/eve POPs thru the period. Expect highs generally in the low to mid 90s, lows low to mid 70s. && .Aviation... [Through 06Z Wednesday] The latest HRRR runs and GFS MOS suggest a good chance of low-end MVFR/IFR CIGS through mid morning at every site but KTLH. Conditions will improve to VFR by late morning, outside of scattered TSRA. Initially the TSRA will be concentrated near KTLH, but will spread to KVLD, KABY, and KDHN by afternoon. The probability of TSRA at each terminal is 40-50% today, except 30% at KECP. Of course gusty winds and brief period of poor VIS/CIGS are expected with the stronger storms, but we were not yet confident enough to explicitly forecast these conditions at any site on the 06 UTC TAF package. && .Marine... Winds and seas should be relatively calm during the period - winds generally 10 knots or less and seas generally 2 feet or less. && .Fire Weather... Red flag conditions are not expected this week. && .Hydrology... The Shoal River at Mossy Head briefly approached flood stage early yesterday morning, but the river levels are now falling. There will likely be some heavy rain rates today, and the storm motion will be unusually slow (around 5 kt). This would suggest at least some potential for flooding. However, there appears to be one negative factor that will keep the risk of flooding rather low- the influx of dry air aloft from the south and west. This should help dampen deep moist convection somewhat, preventing updrafts from persisting over any one location for too long. We think the probability of exceeding local flash flood guidance today is about 5% (within 25mi of a point), which is not high enough for a watch. && .Preliminary Point Temps/PoPs... Tallahassee 90 72 95 73 95 / 50 30 50 20 50 Panama City 87 75 90 76 90 / 30 20 30 20 30 Dothan 89 72 93 73 93 / 40 20 40 20 40 Albany 90 72 94 73 94 / 40 40 30 20 30 Valdosta 90 70 96 72 96 / 40 40 40 20 40 Cross City 90 71 94 73 92 / 60 30 40 20 40 Apalachicola 87 74 88 76 88 / 50 20 30 20 30 && .TAE Watches/Warnings/Advisories... FL...None. GA...None. AL...None. GM...None. && $$ NEAR TERM...FOURNIER SHORT TERM...LAMERS LONG TERM...BLOCK AVIATION...FOURNIER MARINE...LAMERS FIRE WEATHER...FOURNIER HYDROLOGY...LAMERS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
307 AM CDT Tue Jul 22 2014 ...Updated long term section... .SHORT TERM...(Today and tonight) ISSUED AT 145 AM CDT TUE JUL 22 2014 Today temperatures will climb to around 100 degrees based the mean mixing depth forecast by the NAM and GFS along with the temperatures at 00z Wednesday in the 850mb to 700mb level. All models, and even guidance, continues to indicated lower dew points today compared to yesterday, however based on verification of dew points from yesterday afternoon it appears that the models are too low by 3-6 degrees. Taking this discrepancies into account and given the expected highs will go ahead an issue a heat advisory for portions of north central Kansas. will need to monitor the Medicine lodge area given several hours of Heat index readings at 104 which is just below advisory criteria. A weak cold front/surface boundary will stall out in northern Kansas by early evening and a surface trough of low pressure will extend south/southwest of this boundary into the panhandle of Oklahoma. Both areas will be the main focusing mechanism for evening convection as CAPE values by 00z climb to greater than 2000 j/kg. Better forcing currently appears to be along and north of the cold front. Also appear the cap will be weaker in this location as well. Will therefore focus main chances for evening and overnight convection along and north of this weak cold front while keeping convection more widely scattered further south. 0-6km shear is forecast to be around 30knots across northern Kansas so strong to marginally severe thunderstorms can not be ruled out. Strong gusty winds currently appears to be the main hazard should any storm develop along the surface lee trough extending south of this cold front early this evening based on model soundings. .LONG TERM...(Wednesday through Monday) ISSUED AT 306 AM CDT TUE JUL 22 2014 A dry pattern is expected Wednesday through Friday as an upper level ridge builds across the Southern and Central Rockies. Weak shortwaves will move around the periphery of this ridge, but they look to move well north of the area and not affect southwest Kansas. In addition, warm mid level temperatures should also cap most convection from initialing across the higher terrain in eastern Colorado. Skies should be partly cloudy through this period. Towards the surface, a trough of low pressure will be located across the KS/CO border Wednesday through Friday morning allowing southerly winds to be felt across western Kansas. As for temperatures, highs Wednesday look to reach into the mid to upper 90s with around 100 degrees expected Thursday and Friday. Lows through sunrise Saturday are expected to be in the lower 70s. A slight cool down is expected this weekend as winds shift to more of an easterly direction and storm chances increase. The upper level ridge slides westward during this time frame as an upper level low moves down through Central Canada and the Northern Plains Saturday then into the Great Lakes region Sunday. This low then stalls across eastern Canada and the Northeast United States for the first part of next week. This feature will help push a cold front through the area Saturday and be the focal point of where convection could initiate. Upslope flow is then expected Sunday into Monday which will help with increased low level moisture and continued chances of thunderstorms. Highs this weekend into Monday look to be in the 90s with close to 100 degrees across the KS/OK border on Saturday. Lows will be in the low 70s Sunday morning decreasing to the mid to upper 60s by Tuesday morning. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1206 AM CDT TUE JUL 22 2014 Ongoing light precipitation will gradually taper off from northwest to southeast early this morning with 05z surface observations, 00z NAM BUFR soundings, and latest HRRR indicating ceilings will be above the 6000ft AGL level with this precipitation. Winds will be variable at 10knots or less around the ongoing precipitation but after 09z become southwest. Wind speeds will increase to near 15knots by late morning and persist through the remainder of the day. VFR conditions are also expected through the day on Tuesday. A weak cold front will approach the Hays area by early evening allowing for the southerly winds to shift to the east/northeast between 00z Tuesday and 03z Tuesday. && .PRELIMINARY POINT TEMPS/POPS... DDC 100 72 95 70 / 10 10 10 10 GCK 100 72 96 70 / 10 10 10 10 EHA 98 70 97 70 / 20 20 10 10 LBL 100 70 97 70 / 0 10 10 10 HYS 102 72 93 70 / 10 20 10 10 P28 101 74 97 72 / 10 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY from Noon today to 8 PM CDT this evening FOR KSZ030-031-046-065-066-081-089-090. && $$ SHORT TERM...Burgert LONG TERM...Hovorka_42 AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
148 AM CDT Tue Jul 22 2014 ...Updated short term discussion... .SHORT TERM...(Today and tonight) ISSUED AT 145 AM CDT TUE JUL 22 2014 Today temperatures will climb to around 100 degrees based the mean mixing depth forecast by the NAM and GFS along with the temperatures at 00z Wednesday in the 850mb to 700mb level. All models, and even guidance, continues to indicated lower dew points today compared to yesterday, however based on verification of dew points from yesterday afternoon it appears that the models are too low by 3-6 degrees. Taking this discrepancies into account and given the expected highs will go ahead an issue a heat advisory for portions of north central Kansas. will need to monitor the Medicine lodge area given several hours of Heat index readings at 104 which is just below advisory criteria. A weak cold front/surface boundary will stall out in northern Kansas by early evening and a surface trough of low pressure will extend south/southwest of this boundary into the panhandle of Oklahoma. Both areas will be the main focusing mechanism for evening convection as CAPE values by 00z climb to greater than 2000 j/kg. Better forcing currently appears to be along and north of the cold front. Also appear the cap will be weaker in this location as well. Will therefore focus main chances for evening and overnight convection along and north of this weak cold front while keeping convection more widely scattered further south. 0-6km shear is forecast to be around 30knots across northern Kansas so strong to marginally severe thunderstorms can not be ruled out. Strong gusty winds currently appears to be the main hazard should any storm develop along the surface lee trough extending south of this cold front early this evening based on model soundings. .LONG TERM...(Tuesday night through Monday) ISSUED AT 150 PM CDT MON JUL 21 2014 A shortwave trough riding over the top of the upper level ridge will progress from the northern plains today into the Great Lakes by Tuesday and then into the Middle Atlantic region by Wednesday. This will help push a cold front into central Kansas by Tuesday evening and northern Oklahoma by Wednesday morning. There is only a slight chance of thunderstorms Tuesday evening along a weak surface trough in far western Kansas and then along the cold front Tuesday night. Aside from some wind and small hail from these high based storms in the evening, high-end severe weather is not expected. It will be humid Wednesday behind the cold front, especially near the Oklahoma state line, but with no upper level support or surface convergence, thunderstorms are not expected. Temperatures should be several degrees cooler, with highs from 93F near interstate 70 to around 97F near the Oklahoma state line. By Thursday, a strong upper level system will move into the northwestern United States, with ridging extending from the Desert Southwest into western Kansas. With renewed lee troughing, high temperatures ought to warm back to the mid and high 90s, with possibly some readings near or over 100F. Little in the way of thunderstorm activity is expected. The next cold front is expected to pass through western Kansas by Saturday or Sunday as the upper level system over the northwestern United States passes over the upper level ridge into the Great Lakes, with the associated cold front moving through western Kansas. There is some disagreement from model to model and model run to model run with the strength of this cold front. Keep in mind that if the front is stronger, then high temperatures could drop lower than currently forecast. Regardless of the solution, high temperatures ought to drop at least several degrees by Sunday. There will be small chances for thunderstorms as the front passes. A more significant cool down is possible by mid next week as an even stronger upper level system moves over the ridge and amplifies over the upper Midwest and Great Lakes regions. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1206 AM CDT TUE JUL 22 2014 Ongoing light precipitation will gradually taper off from northwest to southeast early this morning with 05z surface observations, 00z NAM BUFR soundings, and latest HRRR indicating ceilings will be above the 6000ft AGL level with this precipitation. Winds will be variable at 10knots or less around the ongoing precipitation but after 09z become southwest. Wind speeds will increase to near 15knots by late morning and persist through the remainder of the day. VFR conditions are also expected through the day on Tuesday. A weak cold front will approach the Hays area by early evening allowing for the southerly winds to shift to the east/northeast between 00z Tuesday and 03z Tuesday. && .PRELIMINARY POINT TEMPS/POPS... DDC 100 72 95 70 / 10 10 10 10 GCK 100 72 96 70 / 10 10 10 10 EHA 98 70 97 70 / 10 20 10 10 LBL 100 70 97 70 / 0 10 10 10 HYS 102 72 93 70 / 20 20 10 10 P28 101 74 97 72 / 10 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY from Noon today to 8 PM CDT this evening FOR KSZ030-031-046-065-066-081-089-090. && $$ SHORT TERM...Burgert LONG TERM...Finch AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1209 AM CDT Tue Jul 22 2014 ...Updated synopsis and aviation... .SYNOPSIS... ISSUED AT 1206 AM CDT TUE JUL 22 2014 At 00z Tuesday a 500mb high was located over northeast New Mexico with an upper level ridge axis extending northeast of this high into Illinois. One upper level trough was evident at over northwest Kansas with another, more subtle, upper wave appearing over Nevada near the nose/left exit region of a 250mb jet. Anticyclonic flow was present at the 700mb level with temperatures of +15c at Dodge City and +16c at Amarillo and North Platte at 00z Tuesday. A area of higher 850mb temperatures, +28c to +31c, were located from northwest Colorado into eastern South Dakota. This was also located just ahead of a cold front which extended from eastern Wyoming to eastern North Dakota. 850mb temperature at Dodge City at 00z Tuesday was +27c. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 116 PM CDT MON JUL 21 2014 High pressure aloft will remain centered over southern Colorado and northern New Mexico through the next 48 hours. This will ensure very hot surface temperatures will continue, with most of southwest Kansas rising into the triple digits today and Tuesday. At the same time, a lee side surface trough will be advancing into far western Kansas late this afternoon and evening. This trough will be the focus axis for some convection, and that trough could push some of those thunderstorms a bit farther east late this evening. There could be a slight chance for thunderstorms after midnight in our north and northeast zones, with the surface trough moving through central Kansas. In any case, I will not put very much QPF amounts with these storms. After the hot afternoon, the overnight temperatures will be elevated, and generally in the the lower to mid 70s tonight. Winds will be southwest early in the 15-20 MPH range, and then become more southerly as that surface trough advances farther east and reduce to the 10 to 12 MPH range. On Tuesday, the upper high pressure system will still be in control. However, at the surface, a weak cold front will drop south from the northern plains and essentially drop into that surface trough. This could trigger a few thunderstorms along and near the front/trough, across our north and western zones late in the afternoon. Maximum temperatures will likely occur prior to the front moving south, and thus even the Hays area will likely see 101F readings. Dew points will again be in the mid 50s in our west to the mid to upper 60s in our east, which only gives a max heat index of 103F, just shy of Heat Advisory criteria. This will need to be watched, and updated if needed. Winds on Tuesday should be south at 10 to 12 mph, but shifting to the east in our far eastern counties, on the other side of the trough. .LONG TERM...(Tuesday night through Monday) ISSUED AT 150 PM CDT MON JUL 21 2014 A shortwave trough riding over the top of the upper level ridge will progress from the northern plains today into the Great Lakes by Tuesday and then into the Middle Atlantic region by Wednesday. This will help push a cold front into central Kansas by Tuesday evening and northern Oklahoma by Wednesday morning. There is only a slight chance of thunderstorms Tuesday evening along a weak surface trough in far western Kansas and then along the cold front Tuesday night. Aside from some wind and small hail from these high based storms in the evening, high-end severe weather is not expected. It will be humid Wednesday behind the cold front, especially near the Oklahoma state line, but with no upper level support or surface convergence, thunderstorms are not expected. Temperatures should be several degrees cooler, with highs from 93F near interstate 70 to around 97F near the Oklahoma state line. By Thursday, a strong upper level system will move into the northwestern United States, with ridging extending from the Desert Southwest into western Kansas. With renewed lee troughing, high temperatures ought to warm back to the mid and high 90s, with possibly some readings near or over 100F. Little in the way of thunderstorm activity is expected. The next cold front is expected to pass through western Kansas by Saturday or Sunday as the upper level system over the northwestern United States passes over the upper level ridge into the Great Lakes, with the associated cold front moving through western Kansas. There is some disagreement from model to model and model run to model run with the strength of this cold front. Keep in mind that if the front is stronger, then high temperatures could drop lower than currently forecasted. Regardless of the solution, high temperatures ought to drop at least several degrees by Sunday. There will be small chances for thunderstorms as the front passes. A more significant cooldown is possible by mid next week as an even stronger upper level system moves over the ridge and amplifies over the upper Midwest and Great Lakes regions. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1206 AM CDT TUE JUL 22 2014 Ongoing light precipitation will gradually taper off from northwest to southeast early this morning with 05z surface observations, 00z NAM BUFR soundings, and latest HRRR indicating ceilings will be above the 6000ft AGL level with this precipitation. Winds will be variable at 10knots or less around the ongoing precipitation but after 09z become southwest. Wind speeds will increase to near 15knots by late morning and persist through the remainder of the day. VFR conditions are also expected through the day on Tuesday. A weak cold front will approach the Hays area by early evening allowing for the southerly winds to shift to the east/northeast between 00z Tuesday and 03z Tuesday. && .PRELIMINARY POINT TEMPS/POPS... DDC 72 95 70 98 / 10 10 10 10 GCK 72 96 70 99 / 10 10 10 10 EHA 70 97 70 101 / 20 10 10 10 LBL 70 97 70 101 / 10 10 10 10 HYS 72 93 69 94 / 20 10 10 10 P28 74 97 72 94 / 10 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Burgert SHORT TERM...Burke LONG TERM...Finch AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS CARIBOU ME
327 AM EDT TUE JUL 22 2014 .SYNOPSIS... HIGH PRESSURE WILL SETTLE SOUTHEAST OF THE REGION INTO TONIGHT. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON WEDNESDAY AND CROSS THE REGION FROM NORTHWEST TO SOUTHEAST LATER WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... A WARM SUMMER DAY COMING UP! SOME PATCHY VALLEY FOG POSSIBLE THIS MORNING AND ALONG THE IMMEDIATE COAST AS SEEN ON THE LATEST GOES E SATELLITE IMAGERY. MOST OF THE STRATUS AND FOG HANGING ALONG ROCKLAND AND OFFSHORE ATTM. THE LATEST HRRR SHOWS THE STRATUS AND FOG TO CREEP INTO THE COASTAL REGIONS THIS MORNING AND HANG ON INTO MID MORNING. THE LATEST OBS AND SATELLITE SHOWED THAT THE HRRR IS TOO FAST. THEREFORE BACKED OFF ON KEEPING THE STRATUS AND FOG BEYOND 12Z. THIS WILL NEED TO BE MONITORED THIS MORNING. OTHER THAN THAT, HIGH PRES WILL RIDGE ACROSS THE REGION TODAY W/TEMPERATURES WARMING THROUGH THE COLUMN RIGHT UP THROUGH 500MBS. THIS WILL TRANSLATE DOWN TO THE BLYR FOR A VERY WARM DAY W/A GOOD DEAL OF SUNSHINE. TEMPERATURES ARE EXPECTED TO BE AT LEAST 3 TO 5 DEGREES WARMER THAN THEY WERE ON MONDAY. WE ARE TALKING MID TO POSSIBLY UPPER 80S AWAY FROM THE COAST AS A SW BREEZE KICKS IN. THE COASTAL AREAS WILL BE COOLER AS THE SSW BREEZE WILL KEEP THINGS COOLER, BUT STILL ABLE TO HIT AROUND 80F. HUMIDITY WILL BE ON THE INCREASE THIS AFTERNOON INTO TONIGHT. SKIES FOR THE MOST PART WILL STAY CLEAR W/SOME STRATUS AND FOG FORMING AGAIN AND PUSHING A BIT FURTHER INLAND INTO THE INTERIOR DOWNEAST. STAYED CLOSE TO THE DAYCREW`S ASSESSMENT OF FOG DEVELOPMENT FOR THE BANGOR AND COASTAL REGION. OVERNIGHT LOWS WILL BE VERY MILD RUNNING IN THE MID TO UPPER 60S. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... A VIGOROUS COLD FRONT WILL SWEEP ACROSS NORTHERN AND EASTERN MAINE WEDNESDAY AFTERNOON. SBCAPE VALUES ARE FORECAST TO BE IN THE 1500-2000 J/KG RANGE WITH 90 DCM HEIGHT FALLS IN A 15 HOUR TIME FRAME. EXPECT A QCLS IN THE MID AFTERNOON THROUGH EVENING WITH DISCRETE CELLS POSSIBLE AHEAD OF THE LINE. WILL CONTINUE THE ENHANCED SEVERE WEATHER WORDING IN THE FORECAST. MUCH COOLER AND DRIER AIR USHERS INTO THE REGION ON THURSDAY BEHIND THE COLD FRONT. TEMPERATURES WILL BE 10 TO 12 DEGREES COOLER ON THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A BROAD UPPER LEVEL TROUGH WILL BE OVER EASTERN CANADA AND THE NORTHEAST U.S. BY THE END OF THE WEEK. A BRIEF ZONAL FLOW TO START NEXT WEEK IS REPLACED BY STRONGLY SOUTHWEST FLOW BY MONDAY AS AN UNSEASONABLY STRONG UPPER TROUGH SETS UP OVER THE GREAT LAKES. THIS RESULTS IN AN UNSETTLED PATTERN. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... NEAR TERM: GENERALLY VFR W/THE THREAT FOR IFR FOR KBHB THIS MORNING. THIS WILL BE MONITORED THROUGH THIS MORNING. THERE IS POTENTIAL FOR MVFR/IFR FOR BOTH KBGR AND KBHB LATER TONIGHT AS A SSW FLOW BRINGING LLVL MOISTURE NORTHWARD. SHORT TERM: MVFR CIGS AND VSBYS ARE LIKELY WED AFTN AND EVE AT ALL TAF SITES IN THUNDERSTORMS AS A COLD FRONT SWEEPS ACROSS MAINE. VFR CONDITIONS RETURN FOR WED NGT AND THU. && .MARINE... NEAR TERM: NO HEADLINES. DECIDED TO MENTION A SOUTHERLY SWELL TODAY INTO THIS EVENING AS IS EVIDENT ON THE OBS THIS MORNING. WAVE HEIGHTS WILL BE AROUND 3 FT CREEPING TO 4 FT TONIGHT MAINLY FOR THE OUTER WATERS. THE WAVE GUIDANCE INCLUDING THE SWAN GUIDANCE HAS BEEN OVERDOING THE HEIGHTS BY A FOOT. BASED ON THIS, DECIDED TO CUT BACK THE HEIGHTS BY A FOOT INTO TONIGHT. WINDS WILL GRADUALLY PICK UP LATER TODAY INTO TONIGHT BUT STILL WELL BELOW 20 KT. SHORT TERM: SCA MAY BE NEEDED WEDNESDAY AFTERNOON AND EVENING WITH WAVE HEIGHTS 4-6 FEET AND WIND GUSTS AROUND 25 KNOTS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT SHORT TERM...OKULSKI LONG TERM...OKULSKI AVIATION...HEWITT/OKULSKI MARINE...HEWITT/OKULSKI
AREA FORECAST DISCUSSION
NWS CARIBOU ME
102 AM EDT TUE JUL 22 2014 .SYNOPSIS... HIGH PRESSURE SETTLES SOUTHEAST OF THE REGION OVERNIGHT. A COLD FRONT WILL APPROACH FROM THE NORTH TUESDAY NIGHT...THEN CROSS THE REGION NORTHWEST TO SOUTHEAST WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT. && .NEAR TERM /THROUGH TODAY/... 1255 AM UPDATE...BROUGHT STRATUS THAT IS RESIDING OVER THE GULF OF MAINE IN ALONG THE HANCOCK AND WASHINGTON COUNTY COAST. THE LATEST RUN OF THE HRRR 3KM HAD THIS HANDLED OK BUT A BIT QUICK. THEREFORE, BACKED THE TIMING BACK BY ABOUT 2 HRS. BROUGHT HR LY TEMPERATURES IN LINE W/THE CURRENT READINGS. PREVIOUS DISCUSSION... LATEST SAT IMAGERY DOES SHOW THE DEEPEST CU OVR WRN PTNS OF THE FA AS OF MID THIS AFTN...SO WE WILL LEAVE A MENTION OF ISOLD SHWRS OVR THIS PTN OF THE FA INTO ERLY EVE...BUT SHWRS AND DEEP CU CLDS SHOULD MSLY DISSIPATE AFT SUNSET...LEAVING MCLR SKIES ACROSS ALL OF THE FA OVRNGT. WITH FCST LOWS XPCTD TO REACH OR EVEN FALL BLO CURRENT OBSVD DWPTS OVR VLY LCTNS LATE TNGT/ERLY TUE MORN...WE CANNOT RULE OUT PATCHY VLY FOG DURG THESE HRS..WHICH WE MENTIONED. OTHERWISE...TUE LOOKS TO BE MSLY AND WARMER AS 500 MB HTS CONT TO RISE WITH A BUILDING S/WV RIDGE OVR NEW ENG. WITH A WSW SFC WIND THIS SHOULD RESULT IN ABOUT A 3 DEG C WRMG OF 925MB TEMPS AND A CORRESPONDING 5 DEG F INCREASE IN HI TEMPS TUE AFTN OVR THIS AFTN. LCTNS ALG THE IMMEDIATE COAST WILL BE A LITTLE COOLER TUE AFTN... WITH WINDS BCMG MORE SRLY WITH A SHALLOW AND LMTD INLAND SEA BREEZE BY MID TO LATE AFTN. && .SHORT TERM /TONIGHT THROUGH THURSDAY/... THE MAIN CONCERN FOR THE SHORT TERM WILL BE THE SEVERE WEATHER THREAT FOR WEDNESDAY IN ASSOCIATION WITH A COLD FRONT. AHEAD OF THIS FRONT, A SW FLOW WILL RESULT IN A WARM AND MUGGY NIGHT FOR TUESDAY NIGHT WITH LOWS NOT GETTING BELOW THE MID TO UPPER 60S ACROSS MUCH OF THE FORECAST AREA. LOCALS RIGHT ALONG WITH COAST AND ACROSS THE FAR NORTHWEST WILL BE JUST A BIT COOLER. ALSO EXPECT SOME FOG DOWNEAST FOR TUESDAY NIGHT AS A RESULT OF THE WARM, MUGGY AIRMASS BEING ADVECTED OVER THE COOLER WATER THEN INTO THE COASTAL ZONES. WEDNESDAY WILL BEGIN FAIR WITH HIGHS FOR MOST AREAS CLIMBING WELL INTO THE 80S TO NEAR 90 BY EARLY AFTERNOON ALONG WITH HIGH HUMIDITY. HOWEVER A COLD FRONT MOVING IN FROM THE NORTHWEST WILL TRIGGER THUNDERSTORMS BEGINNING BY EARLY AFTERNOON ACROSS THE CROWN OF MAINE WITH SHOWERS/THUNDERSTORMS PROGRESSING SOUTH AND EAST THROUGH THE REMAINDER OF THE DAY AND REACHING THE COAST BY EVENING. FORECAST CONFIDENCE IS GROWING THAT AT LEAST SOME OF THESE STORMS ARE LIKELY TO BE STRONG TO SEVERE AS FORECAST GUIDANCE DEPICTS SB CAPES IN THE 1000-2000+ J/KG RANGE WITH 0-6 KM SHEAR VALUES OF 30-35 KNOTS...CLOSE TO THE THRESHOLD FOR SOME OF THESE STORMS TO CONTAIN ROTATION. SOME LOW LEVEL DIRECTIONAL SHEAR CAN ALSO BE NOTED IN THE FORECAST PROFILES AS WELL. FINALLY, DEPENDING HOW QUICKLY THE UPPER LEVEL TROUGH IN ASSOCIATION WITH THIS SYSTEM DEEPENS AND COLDER AIR ALOFT WRAPS IN, MID LEVEL LAPSE RATES ALSO HAVE THE POTENTIAL TO BE FAIRLY STEEP. THUS, ORGANIZED MULTICELL CONVECTION EXPECTED FOR WEDNESDAY AFTERNOON INTO THE EARLY EVENING WITH STRONG AND POTENTIALLY DAMAGING WINDS THE BIGGEST THREAT ALTHOUGH CAN`T RULE OUT LARGE HAIL IN ADDITION TO HEAVY RAIN DUE TO HIGH CAPES AND PWATS. HOWEVER THE PROGRESSIVE NATURE OF THE SYSTEM SHOULD HELP LIMIT ANY HYDRO ISSUES. SHOWERS AND STORMS WILL DIMINISH ACROSS MOST OF THE AREA THROUGH THE EVENING AS THE FRONT PUSHES SOUTH AND ALSO DUE TO THE LOSS OF DAYTIME HEATING. HOWEVER DO EXPECT THE FRONT TO SLOW DOWN AS IT REACHES THE COAST AND THIS COULD KEEP SHOWERS GOING A BIT LONGER ALONG THE COAST. ANY LINGERING COASTAL SHOWERS DIMINISH THURSDAY MORNING WITH OTHERWISE FAIR AND MUCH COOLER AND DRIER WEATHER EXPECTED FOR THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... EXPECT A TREND TOWARD COOLER AND OVERALL MORE UNSETTLED CONDITIONS IN THE LONG RANGE AS AN UPPER TROUGH SETS UP IN THE EAST. FAIR AND COMFORTABLE CONDITIONS THURSDAY NIGHT WILL GIVE WAY TO THE CHANCE FOR SOME SHOWERS DEVELOPING BY FRIDAY AFTERNOON IN THE NORTH AS AN OCCLUDED FRONT MOVES SOUTH. ANY SHOWERS DIMINISH FRIDAY NIGHT WITH MORE SCATTERED SHOWERS POTENTIALLY DEVELOPING BY SATURDAY AFTERNOON DUE TO THE UPPER LEVEL TROUGH AND DAYTIME HEATING. ANY SHOWERS AGAIN DIMINISH SATURDAY NIGHT WITH THE POTENTIAL FOR MORE WIDESPREAD SHOWERS BY LATER SUNDAY INTO MONDAY AS GUIDANCE INDICATES SURFACE LOW DEVELOPMENT IN THE VICINITY OF THE EASTERN GREAT LAKES INTO THE NORTHEAST IN ASSOCIATION WITH THE PERSISTING TROUGH ALOFT. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... NEAR TERM: VFR THROUGH TUE...EXCEPT PERHAPS A BRIEF PD OF MVFR OR IFR VSBYS LATE TNGT IN PATCHY VLY FOG SPCLY KPQI...KHUL AND KBGR. OFFSHORE STRATUS MAY PRODUCE A PERIOD OF IFR CEILINGS AT KBHB VERY LATE TONIGHT INTO EARLY TUE MORNING. SHORT TERM: MVFR/IFR WILL BE A CONCERN FOR THE SOUTHERN SITES TUESDAY NIGHT DUE TO COASTAL FOG WITH THE NORTHERN SITES REMAINING VFR.WEDNESDAY LOOKS TO BE AN ACTIVE DAY W/THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS AND LLWS. MVFR AND BRIEF IFR CONDITIONS LIKELY IN THE AFTERNOON INTO THE EVENING WITH THESE SHOWER/STORMS. MVFR/IFR MAY LINGER INTO WEDNESDAY NIGHT FOR THE SOUTHERN SITES WITH ALL SITES BECOMING VFR FOR THURSDAY AND FRIDAY. && .MARINE... NEAR TERM: NO HDLNS XPCTD THRU THE NEAR TERM...WITH WVS SLOWLY BUILDING TOWARD 4 FT OVR OUTERMOST WATERS WITH AN INCREASING SSW WIND FETCH BY LATE TUE AFTN. SHORT TERM: EXPECT SOME FOG TUESDAY NIGHT INTO EARLY WEDNESDAY AS WARM, MOIST AIR MOVES IN OVER THE COOLER WATER. OTHERWISE WINDS/SEAS WILL INCREASE TUESDAY NIGHT INTO WEDNESDAY AHEAD OF A COLD FRONT WITH SEAS HITTING 4-6 FT AND WINDS GUSTING TO AROUND 25 KNOTS. THESE CONDITIONS DIMINISH LATER WEDNESDAY NIGHT INTO THURSDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
325 AM EDT TUE JUL 22 2014 LATEST UPDATE... SYNOPSIS/SHORT TERM/LONG TERM/MARINE .SYNOPSIS... ISSUED AT 325 AM EDT TUE JUL 22 2014 IT WILL BE VERY WARM AND QUITE HUMID TODAY. A COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND TONIGHT. A SIGNIFICANTLY COOLER AND DRIER AIR MASS WILL MOVE IN BEHIND THAT FRONT FOR MID TO LATE WEEK. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 325 AM EDT TUE JUL 22 2014 OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE CONVECTIVE/SEVERE WX POTENTIAL THIS AFTERNOON THROUGH TONIGHT. IT WILL BE HOT AND HUMID TODAY WITH SOME SUN AND STRONG SSW FLOW WAA HELPING TO BOOST MAX TEMPS INTO THE 85 TO 90 DEGREE RANGE THIS AFTERNOON WITH DEW POINTS REACHING THE MID TO UPPER 60S. WE EXPECT SEVERE CONVECTION OVER MN AND EXTREME NW WI EARLY THIS MORNING TO TRACK ACROSS FAR NORTHERN WI AND THE U.P. THIS MORNING. HOWEVER THAT ACTIVITY WILL STAY WELL TO THE NW OF OUR FCST AREA. HOWEVER WE EXPECT A FEW SHOWERS AND TSTORMS TO DEVELOP OVER OUR FAR NW FCST AREA BY LATE AFTN AS THE COLD FRONT MOVES INTO THAT AREA. THE COLD FRONT WILL THEN MOVE QUICKLY ACROSS THE REST OF OUR FCST AREA DURING THE MID TO LATE EVENING HOURS BRINGING SCATTERED SHOWERS AND STORMS. ISOLATED STRONG TO MARGINALLY SEVERE STORMS ARE POSSIBLE MAINLY EARLY TO MID EVENING COINCIDENT WITH PEAK OR NEAR PEAK INSTABILITY WITH POTENTIAL FOR SB/ML CAPE VALUES TO BRIEFLY REACH UP TO AS HIGH AS 2000 J/KG FOR A SMALL PORTION OF OUR SOUTHWESTERN FCST AREA. SHORT RANGE GUIDANCE HAS ALSO TRENDED FASTER WITH FRONTAL TIMING THE PAST 24 HRS WHICH IS ALSO POTENTIALLY MORE FAVORABLE FOR A FEW STRONGER STORMS. THE MOST LIKELY TIME FRAME FOR CONVECTION IS FROM AROUND 23Z THIS EVENING THROUGH 05Z WEDNESDAY AS SUGGESTED BY 00Z 4KM NSSL WRF AND LATEST HRRR SIM Z GUIDANCE. HOWEVER IT IS NOTED THAT 0-6 KM BULK SHEAR IS WEAK AND MAINLY ONLY AROUND 20-25 KTS OFF LATEST SREF GUIDANCE... ALTHOUGH VERY BRIEFLY HIGHER VALUES ARE NOTED OVER OUR FAR NW FCST AERA. UPPER LEVEL SUPPORT FOR MORE ORGANIZED CONVECTIVE DEVELOPMENT PASSES BY WELL NORTH OF OUR FCST AREA. INSTABILITY IS FCST TO DIMINISH RATHER QUICKLY FROM MID TO LATE EVENING. SO THE OVERALL THREAT FOR SEVERE WX LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS IS RATHER LOW/MARGINAL. IT WILL BE BREEZY AND MUCH COOLER/DRIER WEDNESDAY WITH MAX TEMPS ONLY REACHING THE 70S. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM THE NW. HIGH PRESSURE WILL PRODUCE MOSTLY SUNNY SKIES THURSDAY WITH MAX TEMPS IN THE MID TO UPPER 70S. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 325 AM EDT TUE JUL 22 2014 THE MAIN CHALLENGE WITH THE LONG TERM FORECAST IS THE SHOWER AND TSTM POTENTIAL OVER THE COMING WEEKEND. GUIDANCE CONTINUES TO SUGGEST THAT THE PRIMARY CORRIDOR OF HEAVIER MCS ACTIVITY WILL BE SOUTHWEST/SOUTH OF MICHIGAN FRIDAY THROUGH SUNDAY... FROM ERN IOWA TO INDIANA. HOWEVER WE MAY STILL BE IMPACTED BY THE NRN PERIPHERY OF THESE CONVECTIVE COMPLEXES WITH PERIODS OF SHOWERS AND SCATTERED TSTMS...AIDED BY WEAK SHORTWAVES IN THE FAST W/NW FLOW ALOFT. A RATHER POTENT LOOKING SHORTWAVE IS PROGGED TO DROP DOWN FROM THE NORTHWEST SUNDAY NIGHT AND MONDAY... AND THE GFS/ECMWF ARE IN GOOD AGREEMENT ON THIS FEATURE. BEST POPS WILL EXIST DURING THIS PERIOD... FOLLOWED BY HIGH CONFIDENCE BELOW NORMAL TEMPERATURES BEHIND THIS SYSTEM FOR MOST OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1125 PM EDT MON JUL 21 2014 HAZE WILL BE ON THE INCREASE AS A HUMID AIRMASS SPREADS IN FROM THE WEST TONGHT AND TUESDAY. WHILE THE UPSTREAM THUNDERSTORMS ARE FORECASTED TO WEAKEN AS THE TRACK THROUGH WI TONIGHT...THE CHANCE OF THEM MAKING IT TO MI IS NOT ZERO. THEY WILL HAVE TO BE MONITORED OVERNIGHT. A BETTER RISK FOR STORMS AND IMPACTS EXISTS GENERALLY AFTER 22Z ON TUESDAY. A COLD FRONT WILL BE NEARING FROM THE NORTHWEST THEN. && .MARINE... ISSUED AT 325 AM EDT TUE JUL 22 2014 A SMALL CRAFT ADVISORY AND BEACH HAZARDS STATEMENT CONTINUES IN EFFECT FROM GRAND HAVEN NORTHWARD TODAY. WAVE HEIGHTS SHOULD REACH 3 TO 5 FEET WITH HIGHEST WAVES WITHIN THAT RANGE ANTICIPATED NORTH OF KMKG UP TOWARD THE POINTS. STRONGEST WINDS/HIGHEST WAVES WILL OCCUR FROM MID MORNING THROUGH MID EVENING. ANOTHER SMALL CRAFT AND BEACH HAZARDS STATEMENT WILL EVENTUALLY BE NEEDED FOR WEDNESDAY FOR STRONG NORTHERLY FLOW BEHIND THE COLD FRONT. THE HIGHEST WAVES WEDNESDAY WILL OCCUR SOUTH OF GRAND HAVEN. && .HYDROLOGY... ISSUED AT 334 PM EDT MON JUL 21 2014 WIDESPREAD SIGNIFICANT RAINFALL LOOKS UNLIKELY TUESDAY NIGHT AND WEDNESDAY. GENERALLY WE ARE EXPECTING A QUARTER TO THREE QUARTERS OF AN INCH OF RAINFALL WITH HIGHER AMOUNTS POSSIBLE IN HEAVIER THUNDERSTORMS. NOT ALL LOCATIONS ARE EXPECTED TO RECEIVE RAINFALL WITH THIS COLD FRONT. WITH A FAIRLY QUICK MOVING LINE OF CONVECTION ALONG THE FRONT...FLOODING IS A GREATLY MITIGATED THREAT. RIVERS HAVE BEEN FALLING STEADILY AND ASIDE FROM A TEMPORARY BUMP IN SOME LEVELS ON WEDNESDAY THIS TREND SHOULD CONTINUE FOR THE REST OF THE WEEK. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT FROM 10 AM EDT THIS MORNING THROUGH THIS EVENING FOR MIZ037-043-050. LM...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR LMZ847>849. && $$ SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...MEADE AVIATION...MJS HYDROLOGY...HOVING MARINE...LAURENS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1153 PM CDT Mon Jul 21 2014 .UPDATE: Issued at 920 PM CDT Mon Jul 21 2014 The going forecast remains on track this evening, with only minor changes to account for near-term trends. The HRRR has continued to indicate some showers developing over northeastern MO and west central IL around daybreak, but recent runs have gotten more conservative. Therefore, have maintained the dry forecast given low confidence. JP && .SHORT TERM: (Tonight through Tuesday) Issued at 322 PM CDT Mon Jul 21 2014 The forecast is evolving pretty much as expected today and the trends anticipated through tomorrow still look on track. Temperatures tonight will be milder than last night with a gradual increase in some mid/high clouds from the northwest late tonight. Still wondering if we might see a few high based showers with this mid level moisture and steep lapse rates near and just after dawn across north central/northeast Missouri, but at this point my confidence is not high enough to add pops and later shifts will need to keep a close eye. Otherwise the hotest day of the week is still on tap for Tuesday with a strong low-level thermal ridge focused across the northern half of the CWA with H85 temps above +22 degC, favoring widespread highs in the 90s. The northwest 1/3-1/2 of the CWA should have peak heat index values above 100 degrees. If the dew points top the mid 70s across northeast Missouri, then some locations might see heat indices hit advisory criteria of 105+. At this point my forecast is just below that value. Warm mid level temperatures of +12 to +14 degC should sufficiently cap surface based convection. Glass .LONG TERM: (Tuesday Night through Next Monday) Issued at 322 PM CDT Mon Jul 21 2014 A short wave will dig across the upper-mid MS valley and into the Great Lakes Tuesday night into Wednesday, and this will send a formidable cold front across the region. The air mass ahead of the front will be moist and unstable and height falls/cooling aloft associated with the upper wave should be sufficient for scattered thunderstorms/multicell clusters with the progressing front. The front and precipitation threat should be south of the CWA by early Wednesday evening. Deepening of the eastern trof and and an expansive surface high in the wake of the cold front will bring another nice couple of days with below average temperatures for Thursday/Friday. However by late Friday and especially Friday night into Saturday we will be looking at increasing precipitation chances again - first in association with several northwest flow disturbances and the retreating front, and then with another cold front passage. Glass && .AVIATION: (For the 06z TAFs through 06z Tuesday Night) Issued at 1144 PM CDT Mon Jul 21 2014 VFR with sly to swly winds aob 10kts is expected thru Tues afternoon. SUS may see some FG a couple of hours before sunrise Tues morning, however, confidence in this event is decreasing due to greater dewpoint spread and ssely flow. There is some indication that TSRA may form during the pre-dawn hours Tues morning across the srn half of IA. If these TSRA do form, believe they will remain N of UIN, but this remains uncertain. A cdfnt is expected to approach the region Tues evening. This fnt may bring isod to sct TSRA along and just ahead of the fnt with winds becoming nly behind the fnt. Due to less and somewhat uncertain coverage of TSRA, have only added VCTS for now. Specifics for KSTL: VFR and dry thru the TAF period with sly to swly winds ahead of an approaching cdfnt. This fnt is expected to push thru the terminal late Tues night. This fnt may be accompanied by TSRA. However, there is too much uncertainty regarding coverage and occurrence and have kept out of TAF for now. Tilly && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
234 AM MDT TUE JUL 22 2014 .SHORT TERM...VALID FOR TDY AND WED... WEAK SHORTWAVE ENERGY CONTINUES TO LIFT THRU A RELATIVELY MOIST AND UNSTABLE WSW FLOW ALOFT...AND PER LATEST RAP H5 ANALYSIS OUR HEIGHTS HAVE NOT YET BEGUN TO RISE. AT 2 AM THERE EXISTS A FEW LIGHT SHOWERS IN OUR CWA BUT THERE IS MORE UPSTREAM FROM SOUTH CENTRAL MT TO NORTHERN NV. HEIGHT RISES WILL COMMENCE LATER TODAY BUT IN THE MEANTIME AREAS OF PV INTERACTING WITH PWATS ON THE ORDER OF AN INCH SHOULD BE ENOUGH FOR ISOLD SHOWERS/TSTMS ACROSS MUCH OF THE AREA TODAY...AND CANNOT DISCOUNT SOME AFTN DEVELOPMENT AS MID LEVEL CAP WILL BE SLOW TO DEVELOP. FEEL THAT BY LATE AFTN OR EARLY EVENING THE PV WILL HAVE LIFTED NORTH AND MOST SHOWER ACTIVITY WILL END. TEMPS TODAY WILL BE CLOSE TO NORMAL WITH HIGHS IN THE MID 80S TO LOWER 90S. MOST IMPORTANT ISSUE TO ADDRESS TODAY EXISTS IN OUR EAST. SLOWER ONSET OF HEIGHT RISES WILL RESULT IN A SLIGHT RISK OF SEVERE STORMS FROM MILES CITY TO BROADUS EAST. ASCENT WILL COME IN THE FORM OF WEAK SHORTWAVE ENERGY ALONG A MID LEVEL WARM FRONT...AND A LOW LEVEL JET BY EVENING...WITH 1000+ J/KG OF CAPE AND 0-6KM BULK SHEAR ON THE ORDER OF 50 KTS. HAIL AND TO A LESSER DEGREE WIND WILL BE THE PRIMARY THREATS. LOW LEVEL SOUTHEASTERLY FLOW WILL KEEP THE HIGH PWAT AIR IN PLACE...SO HEAVY RAIN IS ALSO A POSSIBILITY. WILL HIGHLIGHT THE RISK FOR SEVERE WEATHER FOR THIS AFTN AND EARLY EVENING IN OUR EAST IN THE HWO/GRAPHIC. RIDGE WILL STRENGTHEN TONIGHT AND WEDNESDAY WITH HEIGHTS EXPECTED TO CLIMB INTO THE 590S...CORRESPONDING WITH 700MB TEMPS TO NEAR +16C. THIS TONGUE OF VERY WARM MID LEVEL AIR AND LACK OF SIGNIFICANT FORCING WILL LIMIT OUR CONVECTIVE POTENTIAL CONSIDERABLY. INSTABILITY AND SHEAR PROFILES WILL BE IMPRESSIVE CLOSE TO THE DAKOTAS BORDER ON WEDNESDAY WITH STRONG SELY SFC FLOW DEVELOPING...SO IF A STORM IS ABLE TO DEVELOP IT WILL HAVE A VERY FAVORABLE ENVIRONMENT TO WORK WITH. WILL KEEP WITH ISOLD TSTMS MENTIONED IN OUR EAST. OUR CENTRAL AND WEST PARTS WILL BE MUCH DRIER WITH DEEPER MIXING. HAVE REMOVED MENTION OF TSTMS FOR MOST OF THIS AREA BUT KEPT ISOLD POPS IN OUR NW...CLOSER TO COOLER MID LEVEL TEMPS AND SHORTWAVE ENERGY IN WESTERN MT. COULD SEE SOME RIDGE RUNNER CONVECTION ACROSS NORTHERN MT WEDNESDAY NIGHT...BUT FEEL THIS WILL STAY NORTH OF OUR CWA. AS FOR TEMPERATURES...WEDNESDAY SHOULD BE THE WARMEST DAY YET OF 2014 FOR MOST OF OUR CWA. GIVEN THE 700MB TEMPS EXPECTED WE SHOULD SEE SOME AREAS REACH THE 100 DEGREE MARK...PERHAPS BILLINGS. HAVE RAISED TEMPS A FEW DEGREES BOTH WEDNESDAY AND WEDNESDAY NIGHT. THE RECORD HIGH OF 101F MAY BE APPROACHED AT LIVINGSTON... ESPECIALLY IF SW WINDS MIX OUT. RECORDS AT BILLINGS...MILES CITY AND SHERIDAN APPEAR TOO HIGH TO BE REACHED ON WEDNESDAY. OF COURSE...THE HOT WEATHER WILL CONTINUE TO WORK ON OUR DRYING FUELS...SETTING THE STAGE FOR A POTENTIALLY CRITICAL FIRE WEATHER DAY BY THURSDAY. JKL .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... THURSDAY STILL SHAPING UP FOR A POSSIBLE CRITICAL FIRE WEATHER DAY AS A DEEP TROUGH AND ASSOCIATED CLOSED LOW ALOFT CRASH THROUGH THE HIGH PRESSURE RIDGE THAT WILL BE OVER THE AREA. MODELS CONSISTENCY REMAINS VERY GOOD WITH CONFIDENCE CONTINUING TO INCREASE WITH THIS SYSTEM. 850 MB TEMPERATURES ARE EXPECTED TO RANGE FROM +28C TO 30C ACROSS THE FORECAST AREA. STRONG COMPRESSIONAL HEATING WILL TAKE PLACE AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH DURING THE LATE AFTERNOON HOURS. GFS SOUNDINGS CONTINUE TO INDICATE MIXING UP TO NEAR 500 MB. THIS WILL CAUSE TEMPERATURES OVER THE CENTRAL AND EASTERN ZONES TO CLIMB TO NEAR 100 DEGREES AT A FEW LOCATIONS. GUSTY WINDS DEVELOPING WITH THE FRONTAL PASSAGE AND THIS COMBINED WITH HUMIDITIES IN THE TEENS...WILL CREATE DANGEROUS FIRE WEATHER CONDITIONS. ZONAL FLOW SETTING UP FRIDAY FOR DRY AND COOLER WEATHER. DRY WEATHER AND NEAR TO SLIGHTLY ABOVE SEASONAL TEMPERATURES WILL CONTINUE THROUGH EARLY NEXT WEEK AS ANOTHER RIDGE OF HIGH PRESSURE BUILDS OVER THE NORTHERN PLAINS. RICHMOND && .AVIATION... ISOLATED SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE AREA TODAY. MVFR CONDITIONS CAN BE EXPECTED IN OR NEAR ANY STORMS. THERE IS A THREAT OF SEVERE THUNDERSTORMS EAST OF A LINE FROM MILES CITY TO BROADUS THIS AFTERNOON AND EVENING. LARGE HAIL AND STRONG WINDS WILL BE THE PRIMARY THREAT WITH THESE STORMS. RICHMOND && .PRELIMINARY POINT TEMP/POPS... TDY WED THU FRI SAT SUN MON ------------------------------------------------------- BIL 090 063/098 066/098 057/085 057/085 058/087 059/090 2/T 11/U 11/N 11/U 11/U 11/U 11/U LVM 090 055/099 056/091 049/083 049/083 049/088 051/090 2/T 21/B 11/N 10/U 01/U 11/U 11/U HDN 092 059/100 062/101 057/086 056/086 057/088 058/091 2/T 11/U 11/G 11/U 11/U 11/U 11/U MLS 090 065/098 067/097 059/085 058/085 059/086 059/088 3/T 22/T 21/U 11/U 11/N 11/U 11/U 4BQ 090 061/098 064/100 058/085 058/085 058/085 058/088 3/T 22/T 21/U 11/U 11/U 11/U 11/U BHK 086 060/091 062/096 057/083 053/083 054/083 054/084 4/T 32/T 22/T 21/U 11/N 11/U 11/U SHR 090 057/098 059/098 053/084 053/084 053/085 054/087 2/T 11/U 11/U 11/U 11/U 11/U 11/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
437 AM EDT TUE JUL 22 2014 .SYNOPSIS... A FRONTAL BOUNDARY WILL LIFT NORTH ACROSS THE AREA AND DISSIPATE TODAY. A STRONGER FRONT WILL APPROACH FROM THE WEST THURSDAY AND MOVE INTO THE AREA FRIDAY...BECOMING STATIONARY SATURDAY...THEN LIFTING BACK NORTH AS A WARM FRONT SUNDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 330 AM TUESDAY...EASTERN NC REMAINS BETWEEN UPPER RIDGING OVER THE WESTERN ATLANTIC AND A CUT-OFF LOW OVER THE GULF STATES WHICH CONTINUES TO BRING A MOISTURE RICH AIRMASS ACROSS THE AREA TODAY...AS IS EVIDENT IN WV IMAGERY AND 00Z KMHX SOUNDING SHOWING PWATS UP TO 2.25". AT THE SURFACE...A STATIONARY FRONT IS POSITIONED JUST OFF THE COAST...WHICH WILL LIFT NORTH ACROSS THE AREA TODAY AND DISSIPATE. CONVERGENCE ALONG THE BOUNDARY...ALONG WITH LINGERING OUTFLOW BOUNDARIES...WILL PROVIDE THE FOCUS FOR CONVECTIVE DEVELOPMENT THROUGH THE DAY. AS SUCH...EXPECT GREATEST COVERAGE OF SHOWERS ALONG COASTAL AREAS THIS MORNING...THEN TRANSITION INLAND AS THE BOUNDARY LIFTS NORTH. THE AIRMASS REMAINS MODESTLY UNSTABLE WITH MUCAPES AROUND 1000-2000 J/KG AND 0-6KM BULK SHEAR REMAINS WEAK...AROUND 15 KT OR LESS...SIMILAR TO YESTERDAY WITH A VERY LOW THREAT FOR SEVERE STORMS. HOWEVER... BUFKIT SOUNDINGS SHOW MBE VELOCITY WEAK THIS MORNING...LESS THAN 10 KT...SUGGESTING HEAVY PRECIP AND POSSIBLE TRAINING OF CELLS RESULTING IN LOCALLY HEAVY RAINFALL WHICH COULD PRODUCE LOCALIZED FLOODING OF POOR DRAINAGE OR LOW LYING AREAS. MBE VELOCITY INCREASES TO 15-18 KT THIS AFTERNOON ALLOWING THE THREAT TO DIMINISH SOMEWHAT. ABUNDANT CLOUDS AND PRECIP WILL HOLD TEMPS TO THE LOW TO MID 80S AGAIN TODAY. && .SHORT TERM /TONIGHT/... AS OF 330 AM TUESDAY...A SHORTWAVE TROUGH AND ATTENDANT COLD FRONT MOVE ACROSS THE GREAT LAKES/MID WEST TONIGHT BRINGING SLIGHT HEIGHT FALLS ALOFT...WHILE THE BERMUDA HIGH STRENGTHENS OFF THE SOUTHEAST COAST ALLOWING WINDS BECOME S/SW. EXPECT SHOWERS/THUNDERSTORMS TO DIMINISH FAIRLY QUICKLY INLAND THIS EVENING WITH LOSS OF DAYTIME HEATING WITH ACTIVITY SHIFTING TO THE COASTAL WATERS AS IS A TYPICAL NOCTURNAL TREND IN THIS PATTERN. PATCHY/AREAS OF FOG OR STRATUS WILL BE POSSIBLE AGAIN TONIGHT. LOWS EXPECTED IN THE LOW TO MID 70S. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... DEEP MSTR WILL CONTINUE TO STREAM OVER AREA BETWEEN UPR RIDGE AND UPR LOW RETROGRADING ACROSS GULF COAST. SFC PATTERN WILL RETURN TO MORE TYPICAL BERMUDA HIGH/INLAND TROF. SCT CONVECTIVE ACTIVITY PSBL ANY TIME...THUS CONTINUED 20-40 POPS...WITH MORE COVERAGE EXPECTED WED AFTN ACRS INLAND SECTIONS. RIDGE BREAK DOWNS WED NIGHT AND THU WITH APPROACH OF SHORT WV TROF AND SFC FRONT FROM THE NW. HIGHER POPS EXPECTED ON THE COAST WED NIGHT WITH PSBL CONVECTION MOVING IN OFF WATER. KEPT 40-60 POPS FOR THU AFTN WITH HIGHEST POPS INLAND ASSOC WITH THE SHT WV...APPROACHING FRONT AND SEA BREEZE FRONT MOVING INLAND. GOOD CHC POPS ALL AREAS THU NIGHT AND FRIDAY WITH FRONT AND SHT WV TROF MOVING INTO AREA. MODELS INDICATE SFC FRONT STALLS JUST S OF AREA SAT MORNING WITH SCT CONVECTION PSBL ACRS SRN SECTIONS WITH SEA BREEZE INTERACTION. FRONT LIFTS BACK N ON SUNDAY BUT KEPT LOW 20/30 POPS DURING THE LATER PART OF THE EXTDD FCST WITH NEAR NORMAL TEMPS. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... SHORT TERM /THROUGH TUESDAY/... AS OF 2 AM TUESDAY...AREAS OF FOG AND STRATUS ACROSS RTES THIS MORNING...MAINLY ALONG AND SOUTH OF HWY 70 BRINGING IFR/LIFR CONDITIONS...AFFECTING MOST TAF SITES EXCEPT PGV. PGV MAY SEE PERIODS OF SUB VFR CONDITIONS THIS MORNING BUT HRRR MODEL SUGGESTING STRATUS WILL MAINLY BE CONFINED SOUTH OF HWY 70. STRATUS WILL LIFT AROUND 12-13Z WITH SCATTERED TO NUMEROUS SHOWERS AND TSTMS EXPECTED ACROSS RTES AGAIN TODAY WITH A MOIST AND UNSTABLE AIRMASS IN PLACE AND A WEAK BOUNDARY LIFTING ACROSS THE AREA. WEAK SHEAR SHOULD PREVENT THE SEVERITY OF STORMS BUT THEY WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL. SHOWERS DIMINISH THIS EVENING WITH LOSS DAYTIME HEATING AND AREAS OF FOG OR STRATUS WILL BE POSSIBLE AGAIN TONIGHT. LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 300 AM TUESDAY...SCATTERED MAINLY DIURNAL CONVECTION POSSIBLE AT TAF SITES THROUGH PERIOD WITH BEST COVERAGE EXPECTED THU AFTN THROUGH FRIDAY AS A COLD FRONT MOVES INTO THE AREA. LATE NIGHT/EARLY AM FOG POSSIBLE ESPECIALLY IN AREAS THAT RECEIVED RAIN THE PREVIOUS DAY. && .MARINE... SHORT TERM/THROUGH TONIGHT/ AS OF 4 AM TUESDAY...A FRONTAL BOUNDARY IS STALLED ACROSS THE SOUTHERN/CENTRAL WATERS THIS MORNING AND IS EXPECTED TO LIFT NORTH ACROSS THE AREA TODAY ALLOWING E/SE WINDS AROUND 15 KT OR LESS TO GRADUALLY SHIFT TO SLY FROM SOUTH TO NORTH THROUGH THE DAY INTO THE EARLY EVENING HOURS...THEN BECOME SWLY AROUND 10-15 KT OVERNIGHT AS THE BERMUDA HIGH STRENGTHENS OFFSHORE. WAVEWATCH AND LOCAL SWAN/NWPS IN GOOD AGREEMENT WITH SEAS CONTINUING AROUND 2-4 FT. LONG TERM /WEDNESDAY THROUGH SATURDAY/ AS OF 300 AM TUESDAY...SW WINDS 10 TO 15 KT AND SEAS 2-4 FT ON WED THEN PRESSURE GRADIENT TIGHTENS UP AHEAD OF AN APPROACHING COLD FRONT. PSBL SMALL CRAFT CONDS FOR SEAS THURSDAY INTO FRIDAY FOR PORTIONS OF THE COASTAL WATERS SOUTH OF OREGON INLET AS SW WINDS INCR TO 15-20 KT AND SEAS BUILD TO 4 TO 6 FT. WINDS SHIFT TO NLY AND SEAS DIMINISH BEHIND A COLD FRONT FRI NIGHT INTO SAT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SK NEAR TERM...SK SHORT TERM...SK LONG TERM...JAC AVIATION...JAC/SK MARINE...JAC/SK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1131 PM CDT MON JUL 21 2014 .UPDATE... ISSUED AT 1123 PM CDT MON JUL 21 2014 HIGH WIND WARNING CRITERIA NON-THUNDERSTORM WINDS HAVE DEVELOPED ON THE BACKSIDE OF A DEPARTING COMPACT INTENSE SURFACE LOW PRESSURE CENTERED JUST SW OF FSE. AS THE LOW PROPAGATES EASTWARD EXPECT THESE STRONGER WINDS TO SPREAD INTO PARTS OF NW MN EARLY THIS AM. AS A RESULT HAVE ISSUED A HIGH WIND WARNING FOR THE NEXT SEVERAL HOURS. OTHERWISE SEVERE THREAT HAS NEARLY EXITED THE FORECAST AREA TO THE EAST. ADJUSTED POPS AND CONFINED SEVERE MENTION TO OUR EASTERN FA BORDER AREA FOR THE NEXT HOUR OR SO. UPDATE ISSUED AT 949 PM CDT MON JUL 21 2014 ADJUSTED POPS TO CURRENT RADAR IMAGERY AND TRIMMED EASTERN ND OUT OF WATCH. UPDATE ISSUED AT 640 PM CDT MON JUL 21 2014 ADJUSTED EARLY EVENING POPS HIGHLIGHTING MAIN CONVECTION OVER THE FAR NW FA. MAIN THREAT WILL BE WIND AND HEAVY RAIN. EXPECT CONVECTION TO GRADUALLY EXPAND AS MAIN COMPLEX MOVES IN FROM THE WEST WITH HEAVY RAIN/DAMAGING WINDS MAIN THREAT. NO OTHER CHANGES. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 315 PM CDT MON JUL 21 2014 CONVECTION TIMING AND SEVERITY WILL BE THE MAIN FORECAST HEADACHE FOR THE SHORT TERM. STORMS HAVE DEVELOPED OVER WESTERN ND A FEW HOURS SOONER THAN ORIGINALLY THOUGHT. A LITTLE BIT OF ACTIVITY HAS FIRED NORTH OF THE BOUNDARY IN THE UPPER DEVILS LAKE BASIN...BUT CONVECTION IN THAT AREA HAS BEEN SUB SEVERE SO FAR. THE STRONGEST ACTIVITY HAS BEEN IN THE WESTERN PART OF THE STATE WITH THE MAIN SHORTWAVE...BUT OUR NORTHWESTERN COUNTIES WILL BE UNDER THE GUN IN THE NEXT FEW HOURS AS THE SHORTWAVE MOVES CLOSER AND THE ATMOSPHERE CONTINUES TO DESTABILIZE WITH ML CAPE ABOVE 3000 J/KG. WITH A SFC BOUNDARY HANGING AROUND IN THE AREA...THERE COULD BE ENOUGH LOW LEVEL HELICITY TO GET STORMS TURNING IF THEY ARE ISOLATED ENOUGH. THUS...TORNADO WATCH FOR OUR NORTHWEST EARLY ON IN THIS EVENT. LATER ON TONIGHT...THE THUNDERSTORMS ARE EXPECTED TO EVOLVE INTO A COMPLEX MOVING ACROSS THE CWA. WITH PLENTY OF MOISTURE FEEDING INTO THE COMPLEX AS DEW POINTS RISE INTO THE 70S...AND THE HIGHLY UNSTABLE AIR MASS...STORMS SHOULD MAINTAIN THEMSELVES AS THEY MOVE INTO THE RED RIVER VALLEY AND THEN INTO MN. BULK SHEAR VALUES ARE AROUND 40 TO 50 KTS ALTHOUGH THE LOW LEVEL SHEAR IS NOT NEARLY AS STRONG AS NEAR THE SFC BOUNDARY. MODEL SOLUTIONS CONTINUE TO POINT TO A BOW ECHO TYPE PATTERN...AND THE HRRR HAS BEEN CONSISTENT ON SHOWING HIGH WIND GUSTS ALONG WITH THE STORMS. SIGNS CONTINUE TO POINT TO A MCS ARRIVING IN THE VALLEY THIS EVENING AND MOVING EASTWARD INTO MN AFTER MIDNIGHT. DERECHO COMPOSITE ON THE SPC MESO PAGE IS IN THE 6 TO 8 RANGE...SO WILL KEEP THE DAMAGING WIND TAGS IN THE GRIDS FOR THIS EVENING. THE OTHER THREAT WILL BE HEAVY RAINFALL. THE MODELS CONTINUE TO CRANK OUT BULLSEYES OF OVER 2 INCHES IN A VERY SHORT TIME PERIOD. WITH PWAT VALUES UP TO 1.5 INCHES AND 850MB MOISTURE TRANSPORT CONTINUING TO PUSH MORE MOISTURE INTO OUR COUNTIES...HEAVY RAINFALL CONTINUES TO SEEM REASONABLE. THE ISSUE WILL BE WHERE IT FALL AND HOW LONG THE PRECIP WILL LAST. MANY OF THE SHORT RANGE MODELS HAVE BEEN TRENDING FURTHER NORTH WITH THE TRACK OF THE CONVECTION...WHICH WOULD TAKE IT ALONG THE NORTHERN EDGE OF THE MOST WARM AND MOIST AIR. THE FLY IN THE OINTMENT WILL BE THE MOVEMENT OF THE STORMS AS THE COMPLEX ACCELERATES ACROSS THE CWA. SINCE THERE HAS BEEN FAIRLY DRY WEATHER THE PAST FEW WEEKS OVER THE VALLEY...WILL HOLD OFF ON ANY FLOOD WATCHES FOR NOW BUT HAVE TO KEEP AN EYE ON THE STORMS AS THEY APPROACH THE MN LAKES COUNTRY LATER TONIGHT. THERE COULD BE SOME LINGERING SHOWERS AND STORMS IN THE EASTERN COUNTIES TOWARDS TOMORROW MORNING...BUT THERE SHOULD BE A DRYING TREND AS A COLD FRONT MOVES IN AND HIGH PRESSURE ARRIVES. TUESDAY WILL BE QUITE A BIT COOLER THAN TODAY...WITH HIGHS IN THE 70S TO LOW 80S AND DEW POINTS BACK DOWN INTO THE 50S. SFC HIGH PRESSURE WILL CONTINUE INTO TUESDAY NIGHT AND KEEP LOWS MUCH COOLER THAN THEY HAVE BEEN THE PAST FEW NIGHTS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 315 PM CDT MON JUL 21 2014 WEDNESDAY TO MONDAY...MODELS IN FAIR AGREEMENT WITH THE EXTENDED TIME FRAME. OVERALL TEMPS REGIME WILL BE NORMAL TO BELOW NORMAL TEMPS WITH DRY WEATHER FEATURED MOST DAYS AS SFC HIGH PRESSURE COMBINED WITH PREDOMINANTLY NW FLOW ALOFT PERSISTS. THE EXCEPTION IS THURSDAY NIGHT INTO FRIDAY AND SUNDAY WITH CHC THUNDERSTORMS AS RIDGING SHUNTS BACK TO THE WEST WITH POTENT SHORT WAVE RIDING OVER THE TOP BRINGING INSTABILITY AND FORCING TO THE NORTHERN PLAINS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1123 PM CDT MON JUL 21 2014 STRONG NON-THUNDERSTORM WINDS WILL AFFECT THE GFK AREA FOR THE NEXT HOUR OR SO MOVING INTO THE TVF AREA AFT MIDNIGHT. WILL NEED TO MONITOR AS SOME OF THE HIGH RESOLUTION MODELS MOVE THESE WINDS INTO BJI IN THE PRE DAWN HOURS. OTHERWISE WILL SEE SOME ISOLD MVFR CIGS IN STRONGER SHOWERS FOR THE NEXT FEW HOURS. AFTER SUNRISE MOST AREAS WILL BE VFR THROUGH THE REMAINDER OF THE PERIOD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...HIGH WIND WARNING UNTIL 4 AM CDT TUESDAY FOR NDZ027-030. MN...HIGH WIND WARNING UNTIL 4 AM CDT TUESDAY FOR MNZ001-002-013>015- 022. && $$ UPDATE...VOELKER SHORT TERM...JR LONG TERM...JK AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
253 AM CDT TUE JUL 22 2014 .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 253 AM CDT TUE JUL 22 2014 ORGANIZED LINE OF CONVECTION WORKING EAST ACROSS MINNESOTA AND NORTHERN WISCONSIN THIS MORNING. LOCAL AND REGIONAL RADARS SHOWING SOME ECHOES DEVELOPING SOUTH OF THE LINE ON THE EDGE OF THE MOISTURE TRANSPORT AXIS. LOOKING AT THE MESO SCALE MODELS THIS MORNING...THE HRRR AND RAP ARE PRETTY MUCH USELESS AS THEY TURN THE SYSTEM MORE NORTHEAST AND DISSIPATE IT WAY TOO QUICKLY. THE 22.00Z HI-RES ARW AND NMM LOOK MUCH MORE REASONABLE WITH THE CONVECTIVE COMPLEX AND CONTINUE MOVING IT EAST TAKING IT JUST NORTH OF THE FORECAST AREA. LOOKING AT THE 22.00Z NAM BUFKIT SOUNDING FOR LADYSMITH...THIS MAKES SENSE AS THE CAP HOLDS IN PLACE THROUGH THE REMAINDER OF THE NIGHT. AS FOR THE DEVELOPING ECHOES OVER THE FORECAST AREA...THESE ARE JUST STARTING TO GET SOME SPRINKLES TO THE GROUND. THE HI-RES NMM SHOWS THE ECHOES CONTINUING THROUGH THE NIGHT UNTIL THE MOISTURE TRANSPORT STARTS TO BEND MORE OFF TO THE EAST BUT DOES NOT REALLY SHOW THEM EXPANDING AND KEEPS THEM SCATTERED. WITH THE MAIN CONVECTIVE COMPLEX EXPECTED TO MOVE BY TO THE NORTH...HAVE LOWERED THE RAIN CHANCES ACROSS THE NORTH DOWN TO ABOUT 40 PERCENT FOR THIS MORNING. TO HANDLE THE LIGHT ECHOES...WILL SHOW ABOUT A 20 PERCENT AS FAR SOUTH AS I90 UNLESS OBSERVATIONS START INDICATING THAT THIS ACTIVITY IS REACHING THE GROUND. FOR THE REMAINDER OF TODAY...THE MAIN SHORT WAVE TROUGH WILL PASS ACROSS LAKE SUPERIOR INTO ONTARIO. A SECONDARY SHORT WAVE TROUGH WILL DROP ACROSS THE REGION DURING THE AFTERNOON AS THE FLOW BECOMES NORTHWEST ALOFT. IT APPEARS THAT THIS SECONDARY SHORT WAVE TROUGH WILL ONLY PRODUCE SOME WEAK PV ADVECTION IN THE 500-300 MB LAYER AS IT MOVES ACROSS. HOWEVER...THE FORCING FROM THIS WAVE DOES NOT LOOK LIKE IT WILL BE ABLE TO INTERACT WITH THE FRONT UNTIL IT HAS MOVED PAST THE AREA. THE NAM BUFKIT SOUNDING FOR BLUE RIVER INDICATES THE CAP WILL HOLD IN PLACE UNTIL LATE THIS AFTERNOON WHILE THE 22.00Z GFS HOLDS IT INTO THE EVENING. WITH THE CAP REMAINING IN PLACE...ALL THE MODELS SUGGEST FURTHER DEVELOPMENT ALONG THE FRONT DOES NOT TAKE PLACE UNTIL THIS EVENING AND SOUTH OF THE FORECAST AREA. JUST IN CASE THE NAM IS CORRECT AND THE CAP DISSIPATES A LITTLE SOONER...HAVE OPTED TO HOLD ONTO A 20 TO 30 PERCENT RAIN CHANCE ACROSS THE SOUTHEAST SECTIONS FOR THE LATE AFTERNOON INTO THE EARLY EVENING. LOOKS LIKE TEMPERATURES WILL HAVE A GOOD OPPORTUNITY TO WARM THIS AFTERNOON AHEAD OF THE FRONT. HIGH TEMPERATURES IN THE UPPER 80S TO LOWER 90S OVER THE SOUTHEAST HALF OF THE AREA ARE A PRETTY GOOD BET. DEW POINTS ARE EXPECTED TO AGAIN GET INTO THE MIDDLE 70S AHEAD OF THE FRONT...WHICH WILL PUSH THE HEAT INDEX IN THE ADVISORY RANGE ACROSS THE SOUTHERN SECTIONS AND WILL BE ISSUING A HEAT ADVISORY TO HANDLE THIS. THE REST OF THE PERIOD LOOKS TO BE QUIET WITH COOLER AND DRIER CONDITIONS AS A LARGE AREA OF HIGH PRESSURE MOVES ACROSS THE REGION FROM CANADA TOWARD THE OHIO RIVER VALLEY. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 253 AM CDT TUE JUL 22 2014 SOME DIFFERENCES BETWEEN THE MODELS ON HOW FAST THE NEXT SYSTEM MOVES INTO THE REGION. THE UPPER LEVEL RIDGE THAT BUILDS OVER THE WESTERN PART OF THE COUNTRY OVER THE FIRST HALF OF THE WEEK...GETS FLATTENED AS AN UPPER LEVEL LOW MOVES ONSHORE FROM THE PACIFIC AND ACROSS SOUTHERN CANADA. THE DIFFERENCES IN THE MODELS COMES FROM HOW FAST SHORT WAVE TROUGHS WILL CUT THROUGH THE FLOW BETWEEN THE UPPER LEVEL LOW AND THE RIDGE. IT LOOKS LIKE THE 22.00Z ECMWF CONTINUES TO BE FASTER THAN THE GFS AND 22.00Z GEM ON BRINGING THE FIRST SHORT WAVE THROUGH. HOWEVER...ALL OF THEM SHOW THE SAME GENERAL PATTERN WITH THE WAVE AND A SURFACE LOW TRACKING FROM THE DAKOTAS SOUTHEAST TOWARD THE OHIO RIVER VALLEY. WITH THE GFS AND GEM BEING A LITTLE SLOWER...WILL INDICATE THE HIGHEST RAIN CHANCES FRIDAY INTO FRIDAY NIGHT. THE NEXT SHORT WAVE TROUGH AND SURFACE LOW STILL LOOK TO COME THROUGH OVER THE WEEKEND AND TRACK FARTHER NORTHEAST THAN THE FRIDAY SYSTEM. THIS SYSTEM WILL BRING SOME RAIN CHANCES TO THE ENTIRE AREA FOR SUNDAY WITH THE BETTER CHANCES OVER CENTRAL WISCONSIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1146 PM CDT MON JUL 21 2014 THE MAIN FOCUS FOR THE TAF SITES IS WITH THE POTENTIAL FOR CONVECTION TUESDAY MORNING ALONG WITH WHEN A COLD FRONT WILL MOVE THROUGH. SHOWERS AND STORMS LOOK LIKE THEY WILL BE STAYING NORTH OF THE TAF SITES...SO HAVE REMOVED THE THUNDER CHANCES FROM THE TAFS. A BKN BAND OF 3-4KFT CUMULUS APPEARS TO BE SHIFTING OFF TO THE EAST AND SHOULD BE OUT OF LSE OVER THE NEXT HOUR OR SO. HIGH LEVEL CLOUD COVER WILL LINGER THROUGH TUESDAY MORNING BEFORE THE COLD FRONT MOVES THROUGH AND SWINGS WINDS AROUND THE NORTHWEST. WINDS WILL EVENTUALLY BECOME LIGHT IN THE EVENING HOURS ON TUESDAY AS HIGH PRESSURE MOVES IN FROM THE WEST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR WIZ054-055-061. MN...NONE. IA...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR IAZ029-030. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1146 PM CDT MON JUL 21 2014 .UPDATE... ISSUED AT 918 PM CDT MON JUL 21 2014 THE MCS CURRENTLY DEVELOPING ACROSS EASTERN NORTH DAKOTA INTO NORTHWEST MINNESOTA IS THE FORECAST CONCERN FOR THE LOCAL AREA. LATEST GUIDANCE SUGGESTS THAT THE 700-800 MB CAP WILL REMAIN STRONG ENOUGH TO KEEP THE COMPLEX FROM DROPPING TOO MUCH SOUTHEAST. CORFIDI VECTORS AND MCS MOTION WOULD SUGGEST A PATH MORE ACROSS NORTHERN MINNESOTA INTO NORTHERN WISCONSIN...WITH A SLIGHT POSSIBILITY OF CLIPPING THE FAR NORTHERN CWA. THUS...THE THREAT FOR A DAMAGING WIND EVENT FOR THE AREA CONTINUES TO DROP. THERE ARE SUGGESTIONS THAT THERE WILL BE AN INCREASE IN 850-700 MB MOISTURE TRANSPORT OVERNIGHT...AND THAT THE CAP WILL WEAKEN ENOUGH TO ALLOW SHOWERS/STORMS TO DEVELOP TOWARD 10-12Z...MAINLY ACROSS WESTERN INTO CENTRAL WISCONSIN. THIS WOULD BE IN CONJUNCTION WITH THE PASSING MCS TO THE NORTH. THE LATEST RUNS OF THE RAP/HRRR SUGGEST THIS IDEA COULD OCCUR AS WELL...SO HAVE ADJUSTED PRECIPITATION CHANCES TO MAINLY AFTER 08Z FOR WESTERN INTO CENTRAL WISCONSIN. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 331 PM CDT MON JUL 21 2014 MAIN FORECAST CONCERNS ARE SEVERE THUNDERSTORM POTENTIAL LATE TONIGHT OVER NORTH CENTRAL WISCONSIN AND HEAT INDEX VALUES LATE TUESDAY MORNING INTO TUESDAY AFTERNOON OVER PORTIONS OF NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN. LATEST RADAR IMAGERY SHOWS THUNDERSTORMS DEVELOPING OVER PORTIONS OF CENTRAL NORTH DAKOTA. THESE SHOULD BE THE BIRTH OF A THUNDERSTORM COMPLEX THAT WILL RACE EAST TONIGHT ACROSS NORTHERN MINNESOTA INTO PORTIONS OF NORTHERN WISCONSIN AND UPPER MICHIGAN. MOST OF THE MESOSCALE MODEL GUIDANCE KEEPS THIS COMPLEX NORTH OF THE INTERSTATE 94 CORRIDOR. HOWEVER...THE NAM...WHICH IS A MAJOR OUTLIER AT THIS TIME...SHOWS CONVECTION FIRING OVER WEST CENTRAL MINNESOTA LATE THIS AFTERNOON INTO THIS EVENING THEN THIS CONVECTION RACES SOUTHEAST INTO THE FORECAST AREA. LOOKING AT FORECAST SOUNDINGS OVER MUCH OF THE FORECAST AREA THERE IS AN IMPRESSIVE ELEVATED MIXED LAYER WHICH IS RESULTING IN A STRONG CAP IN PLACE. THE CONVECTION WILL HAVE TO OVERCOME THIS CAP AND WITHOUT A STRONG LOW LEVEL JET THIS WILL BE DIFFICULT TO DO. THE 17Z HRRR SHOWS A FEW CELLS MAKING IN INTO WEST CENTRAL WISCONSIN AFTER MIDNIGHT SO WILL HAVE TO SEE IF THIS PANS OUT. HAVE DECIDED TO REDUCE POPS ACROSS MUCH OF THE FORECAST AREA TONIGHT WITH THE EXCEPTION OF CLARK AND TAYLOR COUNTY WHERE THE MCS COULD IMPACT THESE AREAS WITH DAMAGING WINDS THE MAY CONCERN. A COLD FRONT THEN SAGS SOUTH ACROSS THE AREA ON TUESDAY. SOME OF THE WARMEST AIR AT 925 MB MAKES IT INTO NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN WHERE 925 MB TEMPERATURES CLIMB TO AROUND 27 C. TEMPERATURES COULD CLIMB TO THE UPPER 80S TO AROUND 90 OVER PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THESE TEMPERATURES COMBINED WITH DEWPOINTS IN THE MID TO UPPER 70S WILL PRODUCE HEAT INDEX VALUES AROUND 100. THIS HEAT LOOKS TO BE VERY SHORT LIVED WITH THE COLD FRONT SWEEPING THROUGH LATE TOMORROW AFTERNOON SO HAVE HAVE NOT ISSUED A HEAT ADVISORY AT THIS TIME. SHOWERS AND STORMS WILL BE POSSIBLE ALONG THE FRONT TUESDAY AFTERNOON INTO EARLY TUESDAY EVENING BUT AGAIN THE CAP WILL BE A MAJOR LIMITING FACTOR. MOST OF THE FORECAST MODELS KEEP THE AREA DRY. GIVEN THE AMOUNT OF SURFACE BASED CAPE THAT DEVELOPS AHEAD OF THE FRONT OVER NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN...COULD SEE A STORM OR TWO DEVELOP ALONG THE FRONT LATE IN THE AFTERNOON SO WILL KEEP CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE LATE AFTERNOON INTO THE EARLY EVENING. VERY COMFORTABLE TEMPERATURES RETURN IN THE WAKE OF THE FRONT TUESDAY NIGHT WITH TEMPERATURES FALLING INTO THE UPPER 50S TO LOWER 60S. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 331 PM CDT MON JUL 21 2014 HIGH PRESSURE BUILDS INTO THE REGION TUESDAY NIGHT AND REMAINS OVER THE REGION THROUGH THURSDAY PROVIDING QUIET AND COMFORTABLE CONDITIONS. PLAN ON HIGHS IN THE 70S WITH LOWS IN THE 50S TO AROUND 60. WITH THE HIGH OVERHEAD WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR SOME PATCHY VALLEY FOG DURING THE LATE NIGHT AND EARLY MORNING HOURS THURSDAY MORNING...BUT CLOUD COVER COULD PREVENT THIS FROM FORMING. CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN THURSDAY NIGHT INTO THE WEEKEND AS ACTIVE NORTHWEST FLOW SETS UP ACROSS THE REGION. A TROUGH DIVES INTO THE UPPER MISSISSIPPI RIVER VALLEY ON SUNDAY AND DEEPENS A LARGER SCALE TROUGH OVER THE ENTIRE GREAT LAKES REGION EARLY NEXT WEEK. THIS WOULD SET THE STAGE FOR WELL BELOW NORMAL TEMPERATURES OVER THE AREA GOING INTO EARLY NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1146 PM CDT MON JUL 21 2014 THE MAIN FOCUS FOR THE TAF SITES IS WITH THE POTENTIAL FOR CONVECTION TUESDAY MORNING ALONG WITH WHEN A COLD FRONT WILL MOVE THROUGH. SHOWERS AND STORMS LOOK LIKE THEY WILL BE STAYING NORTH OF THE TAF SITES...SO HAVE REMOVED THE THUNDER CHANCES FROM THE TAFS. A BKN BAND OF 3-4KFT CUMULUS APPEARS TO BE SHIFTING OFF TO THE EAST AND SHOULD BE OUT OF LSE OVER THE NEXT HOUR OR SO. HIGH LEVEL CLOUD COVER WILL LINGER THROUGH TUESDAY MORNING BEFORE THE COLD FRONT MOVES THROUGH AND SWINGS WINDS AROUND THE NORTHWEST. WINDS WILL EVENTUALLY BECOME LIGHT IN THE EVENING HOURS ON TUESDAY AS HIGH PRESSURE MOVES IN FROM THE WEST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE.......ZT SHORT TERM...WETENKAMP LONG TERM....WETENKAMP AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
426 AM PDT Tue Jul 22 2014 .Synopsis... An upper wave moves over NorCal today with showers and potential thunderstorms. Then expect a warming trend Wednesday into the weekend. && .Short Term Discussion (Today through Thursday)... An upper level disturbance is lifting northward off the central CA coast this morning. Yesterday, this wave didn`t appear to be too unstable, and we only really had thunderstorm activity over the northern mountains with the max heating of the afternoon. However, looking at HRRR Composite Ref, NAM/GFS ModTT forecast procedures, as well as actual isolated showers/thunderstorms west of Monterey and Half Moon Bays, the instability is a bit more than anticipated this morning. Therefore, we have added isolated showers/thunderstorms this morning for the NW side of our forecast area from Lake/Yolo through Shasta/western Plumas counties. Then we kept the afternoon thunderstorm mention over just the northern mountains to include some of the Sierra. These storms this morning are moving at nearly 40 mph to the NNE. They are making it into San Fran Bay Area as of 410 am and we expect showers to be over Lake/Yolo county area around sunrise. The short wave disturbance moves out of the area tonight and by Wednesday, the atmosphere is more stable under the southwest flow aloft with the main upper level trough just offshore of NW CA. Wind will likely be breezy through the Delta and over the mountains Wednesday with a shot at seeing some marine stratus advect into and develop within the southern Sacramento Valley early in the morning. So we will have to wait until Thursday to really see the max temperatures climb and humidity lower. JClapp .Extended Discussion (Friday through Tuesday) Ridging building in from the Desert SW over NorCal through the extended period resulting in warming temperatures. Some triple digit heat is possible in portions of the Central Valley by Friday becoming more widespread over the weekend. Models showing relatively dry atmosphere into the first half of the weekend but show some monsoonal moisture advecting northward. The GFS/EC have southeast flow aloft with an embedded wave over southern/western NV on Sunday/Monday with a hint of monsoon moisture creeping up the Sierra. The timing of any moisture surge is debatable at this time, but the main theme is the increasing potential for another round of a subtropical surge and resultant thunderstorm development, mainly over the mountains, late in the forecast period. JClapp && .Aviation... General VFR conditions today with scattered mid clouds, though isolated SHRA/TSRA possible over the Coastal and northern mtns, and extending into western and northern portions of the Sacramento Valley. Southerly Valley winds gusting to 20 kt north of I80, 18z- 06z. Delta Breeze gusting to 30 kt. EK && .STO Watches/Warnings/Advisories... None. && $$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
950 AM EDT TUE JUL 22 2014 .DISCUSSION... CURRENT-THIS AFTERNOON... SHOWERS AND STORMS OVER THE GULF STREAM MOVING NORTH AND AWAY FROM LAND. LATEST RUC SURFACE ANALYSIS AND 500MB PLOT SHOWS INVERTED TROUGHING PATTERN OVER FLORIDA AND UNDER THE SOUTH TO SOUTHWEST FLOW AHEAD OF THE UPPER LEVEL LOW OVER SOUTHERN ALABAMA. VERY MOIST ATMOSPHERE WITH PRECIPITABLE WATER VALUES AROUND 2 INCHES WILL CONTINUE TODAY. THE STRONGER MID LEVEL SUPPORT...VORTICITY... IS NORTH OF CENTRAL FLORIDA THUS CONVECTION WILL BE BY SEA BREEZE INITIATION AND BOUNDARIES INTERACTING WITH EACH OTHER IN THE AFTERNOON AND LINGERING ON THROUGH THE EVENING. WEAK STEERING FLOW WILL MEAN THAT STORMS WILL BE CAPABLE OF PRODUCING HEAVY RAIN ALONG WITH GUSTY DOWN BURSTS WINDS AND CLOUD TO GROUND LIGHTNING STRIKES. MID LEVEL TEMPERATURES OVER CENTRAL AND NORTH FLORIDA PER THE 6AM AND 8AM SOUNDINGS WERE AROUND -6C WHILE TO THE NORTH...TALLAHASSEE AND TO THE SOUTH...KEY WEST... THE 500MB TEMPERATURES WERE COOLER AT -8.5C AND -7.1C RESPECTIVELY. YESTERDAY PROVED THAT SMALL HAIL MAY NOT BE RULED OUT EVEN WITH 500MB TEMPERATURES IN THE -6C TO -7C RANGE. NO SIGNIFICANT CHANGES PLANNED FOR THE MORNING ZONE UPDATE. PREVIOUS ZONES DISCUSSION TODAY-TONIGHT...CUT OFF LOW ALOFT ACROSS THE WESTERN FLORIDA PANHANDLE WILL RETROGRADE SLIGHTLY TO THE MISSISSIPPI DELTA REGION. THIS WILL ALLOW ATLANTIC RIDGE TO NUDGE WESTWARD TOWARDS THE FLORIDA PENINSULA. A DEEP LAYER OF SOUTHERLY FLOW WILL DEVELOP AS A RESULT...WHICH SHOULD LIFT A VERY WEAK LOW LEVEL TROUGH OUT TO THE NORTH OR GRADUALLY WASH IT OUT. THIS WEAK TROUGH HAS BEEN FOCUSING MOISTURE CONVERGENCE ALONG THE COAST EARLY THIS MORNING WITH SCATTERED SHOWERS OCCURRING. THIS MAY CONTINUE FROM THE CAPE NORTH INTO LATE MORNING. THE DEEP SOUTHERLY FLOW WILL KEEP HIGH MOISTURE IN PLACE. THE GFS SHOWS PRECIPITABLE WATER 2 INCHES OR GREATER. THIS SHOULD LEAD TO A LITTLE EARLIER THAN NORMAL CONVECTIVE INITIATION ALONG THE EAST COAST SEA BREEZE...DURING THE LATE MORNING OR EARLY AFTERNOON. A LIGHT SOUTHWEST STEERING FLOW IS FORECAST WHICH MIGHT KEEP THE SEA BREEZE CONVECTION NEAR THE COAST WELL INTO THE AFTERNOON. EXPECT THAT OUTFLOW BOUNDARIES WILL PUSH INLAND DURING THE MID TO LATE AFTERNOON AND STRONGER BOUNDARY INTERACTIONS SHOULD OCCUR ACROSS THE INTERIOR COUNTIES. THEREFORE EXPECT BOTH COAST AND INLAND TO GET A RATHER HEALTHY COVERAGE OF SHOWERS AND STORMS. MOS POPS ARE 50-60 PERCENT BUT WILL GO WITH LIKELY RAIN CHANCES AREAWIDE. A FEW SHOWERS/STORMS MAY LINGER A LITTLE PAST SUNSET SO WILL MATCH THE 20-30 PERCENT MOS POPS FOR THIS EVENING. WED-THU...MID-LEVEL TROUGH OVER THE NORTH GOMEX WILL RETROGRADE SLOWLY TOWARD THE SOUTHERN LOUISIANA COAST...THEN EVENTUALLY WILL WEAKEN AND BECOME STRETCHED OUT NORTHEAST-SOUTHWEST FROM THE MID ATLC STATES THROUGH THE TEXAS EAST COAST. MID-LEVEL RIDGING OVER THE BAHAMAS/FLORIDA PENINSULA WILL GRADUALLY WEAKEN AND BECOME SUPPRESSED SOUTHEASTWARD BY THE END OF THE PERIOD. DEEP LAYER MOISTURE VALUES IN THE NEIGHBORHOOD OF TWO INCHES WILL BE COMMON. THE PRESSURE GRADIENT AT THE SURFACE REMAINS WEAK WITH LIGHT WINDS AND DAILY INLAND MOVING SEA BREEZES ON EITHER SIDE OF THE PENINSULA. TEMPERATURES AT 500 MB ARE FORECAST TO BE RELATIVELY WARM FROM -6C TO -7C BUT PARAMETERS WILL STILL BE PRESENT TO CONTINUE SLIGHTLY ABOVE SEASONAL POP CHANCES IN THE 40 TO 50 PERCENT RANGE EACH AFTERNOON/EARLY EVENING. STEERING FLOW FOR STORMS WILL REMAIN LIGHT AND ERRATIC. THE MAIN THREATS FROM STORMS CONTINUE TO BE LOCALLY HEAVY RAINFALL...FREQUENT LIGHTNING AND GUSTY WINDS. AFTERNOON HIGHS IN THE UPPER 80S TO AROUND 90 DEGREES AT THE COAST WITH LOW TO MID 90S INLAND. HEAT INDICES WILL RANGE FROM 98F-103F EACH AFTERNOON. OVERNIGHT LOWS IN THE LOW TO MID 70S. FRI-MON...MID-LEVEL TROUGHING WILL ENCOMPASS THE EASTERN CONUS DURING THIS TIME AS A LARGE RIDGE AMPLIFIES OVER THE WESTERN CONUS. DEEP LAYER SOUTHWEST TO WEST-SOUTHWEST FLOW WILL BE DOMINANT THROUGH THE PERIOD. SUFFICIENT MOISTURE...THE DAILY SEA BREEZE REGIME AND VARIOUS OTHER AFTERNOON BOUNDARY COLLISIONS SHOULD ALLOW FOR A 40 TO 50 PERCENT CHANCE POP THROUGH THIS PERIOD. THE WESTERLY STEERING FLOW...WHILE REMAINING LIGHT...WILL STILL PUSH STORMS TOWARDS THE EAST COAST LATER IN THE DAY AND EVENING. SOME OF THESE STORMS WILL MOVE OFF THE EAST COAST PRESENTING ISSUES FOR MARINERS. AFTERNOON HIGHS AND OVERNIGHT LOWS IN LINE WITH NEAR SEASONAL CONDITIONS THROUGH THE PERIOD. && .AVIATION... BRIEF...TOO SHORT EVEN FOR TEMPO...LOW CEILINGS IN THE LIGHT SOUTHERLY FLOW UNTIL THE SLIGHTLY STRONGER WINDS ABOVE THE SURFACE WORK THEIR WAY DOWN WITH DAYTIME HEATING. LOCAL WRF_ARW3 MODEL RUN SUGGESTING MID TO LATE AFTERNOON...19Z-22Z...STORMS OVER THE INTERIOR AND LITTLE EARLY AT THE COAST. PREVIOUS AVIATION DISCUSSION SCATTERED SHOWERS WITH IFR WILL AFFECT THE COAST EARLY THIS MORNING BUT OTHERWISE VFR WILL OCCUR UNTIL SHOWERS/STORMS GET GOING DURING THE LATE MORNING OR EARLY AFTERNOON ALONG THE EAST COAST SEA BREEZE. THIS ACTIVITY MAY TEND TO LINGER NEAR THE COAST WELL INTO THE AFTERNOON. THE STRONGEST BOUNDARY INTERACTIONS ARE EXPECTED ACROSS THE INTERIOR DURING THE LATE AFTERNOON TO EARLY EVENING. IN ADDITION TO ABOUT AN HOUR OF IFR IN HEAVY RAIN...A FEW STORMS WILL AGAIN PRODUCE FREQUENT LIGHTNING STRIKES. && .MARINE... CURRENT-THIS AFTERNOON... THE TWO NOAA BUOYS AT 20 AND 120NM OFFSHORE WERE RECORDING EAST TO SOUTHEAST WINDS AROUND 5 KNOTS AND AROUND 15 KNOTS AND LONG PERIOD 3 TO 4 FOOT SEAS RESPECTIVELY. THE TWO SCRIPPS BUOYS AT 4 AND 6NM OFF THE COAST WERE RECORDING 2 FOOT LONG PERIOD SEAS. SEA BREEZE MAY BACK THE NEARSHORE WINDS MORE TO THE EAST DURING THE AFTERNOON. MORNING UPDATE HAS NO SIGNIFICANT CHANGES. PREVIOUS MARINE DISCUSSION TODAY-TONIGHT...A SOUTHEAST BREEZE EARLY THIS MORNING IS FORECAST TO VEER TO SOUTHERLY THROUGH THE DAY AND INTO TONIGHT. SPEEDS LOOK TO BE 10 KNOTS OR LESS BUT REACHING 10-15 KNOTS OFFSHORE TONIGHT. HIGH MOISTURE WILL RESULT IN SCATTERED NORTHWARD MOVING SHOWERS AND STORMS THROUGH THE PERIOD. WED-SAT...THE FAIRLY WEAK SURFACE PRESSURE GRADIENT CONTINUES EACH DAY WITH FORECAST SEA BREEZE FORMATION AND MARCH INLAND EACH AFTERNOON. WINDS AOB 10 KTS DURING THE DAYLIGHT PERIOD...EXCEPT NEAR 10-12 KTS NEAR THE COAST EACH AFTERNOON FOLLOWING SEA BREEZE FORMATION. NOCTURNAL WINDS WILL KICK UP FOR A PERIOD OF NEAR 15 KTS EACH EVENING AWAY FROM THE COAST. WIND DIRECTION WILL VARY FROM SSE TO SSW. SEAS AOB 3 FT. THE MAIN MARINE CONCERN WILL CONTINUE TO BE STORMS NEAR THE COAST/NEAR SHORE WATERS EACH AFTERNOON/EVENING AS OVERALL MOISTURE REMAINS ELEVATED. WINDS/SEAS LOCALLY HIGHER INVOF STORMS. && .PRELIMINARY POINT TEMPS/POPS... DAB 89 75 91 75 / 60 20 40 30 MCO 92 75 93 75 / 60 20 50 30 MLB 90 76 90 76 / 60 20 40 30 VRB 89 75 89 75 / 60 30 40 20 LEE 92 76 94 77 / 60 20 50 30 SFB 93 77 94 77 / 60 20 50 30 ORL 92 77 94 77 / 60 20 50 30 FPR 88 74 88 75 / 60 30 40 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ IMPACT WX...BRAGAW PUBLIC SERVICE...CARTWRIGHT FORECASTS...WIMMER
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1145 AM EDT TUE JUL 22 2014 LATEST UPDATE... MARINE .SYNOPSIS... ISSUED AT 325 AM EDT TUE JUL 22 2014 IT WILL BE VERY WARM AND QUITE HUMID TODAY. A COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND TONIGHT. A SIGNIFICANTLY COOLER AND DRIER AIR MASS WILL MOVE IN BEHIND THAT FRONT FOR MID TO LATE WEEK. && .UPDATE... ISSUED AT 1115 AM EDT TUE JUL 22 2014 NO MAJOR CHANGES TO THE GOING FCST FOR TODAY AND TONIGHT. OUR MAIN FOCUS IS ON CONVECTIVE POTENTIAL AND SEVERE THREAT FOR LATE THIS AFTERNOON INTO THE EARLY OVERNIGHT HOURS. QUIET WEATHER ACROSS THE ENTIRE CWFA THIS MORNING...AND THIS IS EXPECTED TO CONTINUE INTO MID AFTERNOON. BAND OF CLOUDS LEFT OVER FROM CONVECTION OUT WEST LAST NIGHT IS MOVING INTO THE NW CORNER OF THE CWFA. THIS IS MAINLY MID LEVEL CLOUD COVER PER THE RADAR AND SFC OBS. NOT MUCH INSTABILITY HAS DEVELOPED YET OVERHEAD. WE CONTINUE TO EXPECT THAT THE NW CORNER OF THE CWFA WILL SEE A DECENT CHC OF CONVECTION AFTER AROUND 21Z OR SO...AND THEN SPREAD SOUTH AND EAST THROUGH THE AREA THEREAFTER. THE MAIN INSTABILITY AXIS IS IMMEDIATELY AHEAD OF THE SFC FRONT LOCATED FROM THE WRN U.P. TO NE IA AS OF 15Z THIS MORNING. THIS WILL SHIFT INTO OUR AREA AS THE LLJ/MAIN MOISTURE TRANSPORT SLIDES IN LATER THIS AFTERNOON AND THIS EVENING. WE WILL SEE SOME DIURNAL INSTABILITY DEVELOP OVERHEAD BEFORE THAT TIME...HOWEVER IT WILL REMAIN GREATLY CAPPED THROUGH MID AFTERNOON. MODEL CONSENSUS SHOWS THAT THE WRN AREAS OF THE CWFA SHOULD SEE 1500-2000 J/KG OF ML AND MU CAPE NOSE INTO THE AREA BY 00Z AND SHIFT SOUTH OF THE AREA BY 06Z VIA AN ELEVATED MIXED LAYER. THE BETTER INSTABILITY IS DEFINITELY WEST OF THE AREA...AND THE BETTER DYNAMICS REMAIN NORTH OF THE AREA. WE DO SEE A SHORT WAVE ACROSS SD THAT APPROACHES THIS EVENING AND WILL LIKELY HELP TO SUPPORT CONVECTION OVER THE AREA. WE BELIEVE THAT THE SEVERE THREAT REMAINS POSSIBLE ACROSS THE AREA...ESPECIALLY ACROSS THE WRN HALF OF THE CWFA SIMILAR TO THE THINKING OF SPC PER THE SWODY1 OUTLOOK. DEEP LAYER SHEAR HAS TRENDED MORE FAVORABLE DURING THE EXPECTED TIME OF CONVECTION PEAKING AT AROUND 30-35 KNOTS...HIGHEST WEST WHERE THE BEST INSTABILITY WILL BE OVER THE AREA. LOW LEVEL INVERSION HEIGHTS ARE NOT EXPECTED TO BE ALL THAT HIGH...SO A WIND THREAT WILL BE POSSIBLE WITH 40 KNOTS IN THE MID LEVELS AND A 30+ KNOT LLJ PRESENT DURING THE TIME OF CONVECTION. LARGE HAIL WILL BE POSSIBLE WITH FAIRLY THICK CAPE IN THE -10C TO -30C LAYER. WE ALSO AGREE WITH SPC ABOUT THE POSSIBILITY OF A TORNADO WITH 0-1KM SHEAR OF 20-25 KNOTS AND 0-1KM HELICITY VALUES 150+ M2/S2. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 325 AM EDT TUE JUL 22 2014 OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE CONVECTIVE/SEVERE WX POTENTIAL THIS AFTERNOON THROUGH TONIGHT. IT WILL BE HOT AND HUMID TODAY WITH SOME SUN AND STRONG SSW FLOW WAA HELPING TO BOOST MAX TEMPS INTO THE 85 TO 90 DEGREE RANGE THIS AFTERNOON WITH DEW POINTS REACHING THE MID TO UPPER 60S. WE EXPECT SEVERE CONVECTION OVER MN AND EXTREME NW WI EARLY THIS MORNING TO TRACK ACROSS FAR NORTHERN WI AND THE U.P. THIS MORNING. HOWEVER THAT ACTIVITY WILL STAY WELL TO THE NW OF OUR FCST AREA. HOWEVER WE EXPECT A FEW SHOWERS AND TSTORMS TO DEVELOP OVER OUR FAR NW FCST AREA BY LATE AFTN AS THE COLD FRONT MOVES INTO THAT AREA. THE COLD FRONT WILL THEN MOVE QUICKLY ACROSS THE REST OF OUR FCST AREA DURING THE MID TO LATE EVENING HOURS BRINGING SCATTERED SHOWERS AND STORMS. ISOLATED STRONG TO MARGINALLY SEVERE STORMS ARE POSSIBLE MAINLY EARLY TO MID EVENING COINCIDENT WITH PEAK OR NEAR PEAK INSTABILITY WITH POTENTIAL FOR SB/ML CAPE VALUES TO BRIEFLY REACH UP TO AS HIGH AS 2000 J/KG FOR A SMALL PORTION OF OUR SOUTHWESTERN FCST AREA. SHORT RANGE GUIDANCE HAS ALSO TRENDED FASTER WITH FRONTAL TIMING THE PAST 24 HRS WHICH IS ALSO POTENTIALLY MORE FAVORABLE FOR A FEW STRONGER STORMS. THE MOST LIKELY TIME FRAME FOR CONVECTION IS FROM AROUND 23Z THIS EVENING THROUGH 05Z WEDNESDAY AS SUGGESTED BY 00Z 4KM NSSL WRF AND LATEST HRRR SIM Z GUIDANCE. HOWEVER IT IS NOTED THAT 0-6 KM BULK SHEAR IS WEAK AND MAINLY ONLY AROUND 20-25 KTS OFF LATEST SREF GUIDANCE... ALTHOUGH VERY BRIEFLY HIGHER VALUES ARE NOTED OVER OUR FAR NW FCST AREA. UPPER LEVEL SUPPORT FOR MORE ORGANIZED CONVECTIVE DEVELOPMENT PASSES BY WELL NORTH OF OUR FCST AREA. INSTABILITY IS FCST TO DIMINISH RATHER QUICKLY FROM MID TO LATE EVENING. SO THE OVERALL THREAT FOR SEVERE WX LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS IS RATHER LOW/MARGINAL. IT WILL BE BREEZY AND MUCH COOLER/DRIER WEDNESDAY WITH MAX TEMPS ONLY REACHING THE 70S. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM THE NW. HIGH PRESSURE WILL PRODUCE MOSTLY SUNNY SKIES THURSDAY WITH MAX TEMPS IN THE MID TO UPPER 70S. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 325 AM EDT TUE JUL 22 2014 THE MAIN CHALLENGE WITH THE LONG TERM FORECAST IS THE SHOWER AND TSTM POTENTIAL OVER THE COMING WEEKEND. GUIDANCE CONTINUES TO SUGGEST THAT THE PRIMARY CORRIDOR OF HEAVIER MCS ACTIVITY WILL BE SOUTHWEST/SOUTH OF MICHIGAN FRIDAY THROUGH SUNDAY... FROM ERN IOWA TO INDIANA. HOWEVER WE MAY STILL BE IMPACTED BY THE NRN PERIPHERY OF THESE CONVECTIVE COMPLEXES WITH PERIODS OF SHOWERS AND SCATTERED TSTMS...AIDED BY WEAK SHORTWAVES IN THE FAST W/NW FLOW ALOFT. A RATHER POTENT LOOKING SHORTWAVE IS PROGGED TO DROP DOWN FROM THE NORTHWEST SUNDAY NIGHT AND MONDAY... AND THE GFS/ECMWF ARE IN GOOD AGREEMENT ON THIS FEATURE. BEST POPS WILL EXIST DURING THIS PERIOD... FOLLOWED BY HIGH CONFIDENCE BELOW NORMAL TEMPERATURES BEHIND THIS SYSTEM FOR MOST OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 750 AM EDT TUE JUL 22 2014 THE PRIMARY AVIATION CONCERN FOR TODAY WILL BE THE INCREASING SOUTHWEST SFC WINDS WHICH WILL BE GUSTING TO 20-25 KNOTS AT MOST LOCATIONS BY NOON. STRONGEST GUSTS SHOULD BE AT MKG. THE FOCUS THIS EVENING FOR THE TERMINALS WILL BE THE LINE OF SCTD TSTMS WHICH MOVES SOUTHEAST THROUGH SRN LWR MI FROM 23Z-06Z. THE STORMS WILL IMPACT MKG FIRST AND JXN LAST... BUT ANY ONE LOCATION SHOULD ONLY SEE ABOUT A 2-4 HOUR WINDOW OF TSTMS IN THE VICINITY. A BRIEF PERIOD OF IFR IS POSSIBLE WITH ANY TSTM OTHERWISE LIGHT MVFR FOG/HAZE EXPECTED THIS EVENING DUE TO THE HIGH DEW POINTS NEAR 70 AHEAD OF THE APCHG COLD FRONT. STORMS WILL EXIT BY 06Z... BUT THE POTENTIAL FOR SOME MVFR CIGS WILL DEVELOP AFTER 09Z. SFC WINDS WILL SHIFT TO THE NORTH TONIGHT BEHIND THE COLD FRONT AND WILL PROBABLY REMAIN GUSTY AT TIMES... ESPECIALLY AT MKG. && .MARINE... ISSUED AT 1145 AM EDT TUE JUL 22 2014 BEACH HAZARDS EVENT UNDERWAY AND GOING DOWN AS EXPECTED THUS FAR. THE LUDINGTON BUOY IS CURRENTLY SHOWING 4.6 FOOT WAVES AND THE WEBCAM THERE IS SHOWING SOME PRETTY BIG WAVES AT TIMES SMACKING THE SOUTH BREAKWALL. HOFFMASTER STATE PARK HAD 4 FOOTERS IN THEIR MORNING BEACH OB. IN LOOKING AT THE GRAND HAVEN WEBCAM FEELING OK WHERE WE HAVE THE BREAK IN THE SMALL CRAFT ADVISORY AND BEACH HAZARDS STATEMENT...WHICH IS JUST NORTH OF GRAND HAVEN. THE NORTHERN PORTIONS OF THE OTTAWA ZONE (GRAND HAVEN) WILL BE BORDERLINE THIS AFTERNOON WITH WAVES HOVERING AROUND THE 2-4 FOOT RANGE. HAVE OPTED TO JUMP INTO THE NORTH FLOW PORTION OF THE EVENT NOW AS WELL. HAVE EXTENDED THE NORTHERN HALF OF THE MARINE PRODUCTS SCA/BHS THROUGH TOMORROW EVENING. IN THE SOUTH HALF HAVE THEM STARTING UP AT 06Z TONIGHT AND LASTING THROUGH WEDNESDAY NIGHT AS THE FLOW COMES AROUND TO THE NORTH. IN TERMS OF BEACH IMPACT TODAY/S EVENT IN THE NORTH HALF OF THE MARINE AREA MAY BE THE HIGHER THREAT GIVEN THE WARM TEMPS...AND THEREFORE A LARGER BEACH POPULATION. TOMORROW/S WAVES WILL BE BIGGER BUT THE IMPACT MAY BE MITIGATED BY COOLER BEACH TEMPERATURES...RESULTING IN LESS FOLKS ON THE BEACH AND IN THE WATER. && .HYDROLOGY... ISSUED AT 334 PM EDT MON JUL 21 2014 WIDESPREAD SIGNIFICANT RAINFALL LOOKS UNLIKELY TUESDAY NIGHT AND WEDNESDAY. GENERALLY WE ARE EXPECTING A QUARTER TO THREE QUARTERS OF AN INCH OF RAINFALL WITH HIGHER AMOUNTS POSSIBLE IN HEAVIER THUNDERSTORMS. NOT ALL LOCATIONS ARE EXPECTED TO RECEIVE RAINFALL WITH THIS COLD FRONT. WITH A FAIRLY QUICK MOVING LINE OF CONVECTION ALONG THE FRONT...FLOODING IS A GREATLY MITIGATED THREAT. RIVERS HAVE BEEN FALLING STEADILY AND ASIDE FROM A TEMPORARY BUMP IN SOME LEVELS ON WEDNESDAY THIS TREND SHOULD CONTINUE FOR THE REST OF THE WEEK. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR MIZ056-064-071. BEACH HAZARDS STATEMENT THROUGH LATE WEDNESDAY NIGHT FOR MIZ037- 043-050. LM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR LMZ847>849. SMALL CRAFT ADVISORY FROM 2 AM WEDNESDAY TO 8 AM EDT THURSDAY FOR LMZ844>846. && $$ UPDATE...NJJ SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...MEADE AVIATION...MEADE HYDROLOGY...HOVING MARINE...DUKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1115 AM EDT TUE JUL 22 2014 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 325 AM EDT TUE JUL 22 2014 IT WILL BE VERY WARM AND QUITE HUMID TODAY. A COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND TONIGHT. A SIGNIFICANTLY COOLER AND DRIER AIR MASS WILL MOVE IN BEHIND THAT FRONT FOR MID TO LATE WEEK. && .UPDATE... ISSUED AT 1115 AM EDT TUE JUL 22 2014 NO MAJOR CHANGES TO THE GOING FCST FOR TODAY AND TONIGHT. OUR MAIN FOCUS IS ON CONVECTIVE POTENTIAL AND SEVERE THREAT FOR LATE THIS AFTERNOON INTO THE EARLY OVERNIGHT HOURS. QUIET WEATHER ACROSS THE ENTIRE CWFA THIS MORNING...AND THIS IS EXPECTED TO CONTINUE INTO MID AFTERNOON. BAND OF CLOUDS LEFT OVER FROM CONVECTION OUT WEST LAST NIGHT IS MOVING INTO THE NW CORNER OF THE CWFA. THIS IS MAINLY MID LEVEL CLOUD COVER PER THE RADAR AND SFC OBS. NOT MUCH INSTABILITY HAS DEVELOPED YET OVERHEAD. WE CONTINUE TO EXPECT THAT THE NW CORNER OF THE CWFA WILL SEE A DECENT CHC OF CONVECTION AFTER AROUND 21Z OR SO...AND THEN SPREAD SOUTH AND EAST THROUGH THE AREA THEREAFTER. THE MAIN INSTABILITY AXIS IS IMMEDIATELY AHEAD OF THE SFC FRONT LOCATED FROM THE WRN U.P. TO NE IA AS OF 15Z THIS MORNING. THIS WILL SHIFT INTO OUR AREA AS THE LLJ/MAIN MOISTURE TRANSPORT SLIDES IN LATER THIS AFTERNOON AND THIS EVENING. WE WILL SEE SOME DIURNAL INSTABILITY DEVELOP OVERHEAD BEFORE THAT TIME...HOWEVER IT WILL REMAIN GREATLY CAPPED THROUGH MID AFTERNOON. MODEL CONSENSUS SHOWS THAT THE WRN AREAS OF THE CWFA SHOULD SEE 1500-2000 J/KG OF ML AND MU CAPE NOSE INTO THE AREA BY 00Z AND SHIFT SOUTH OF THE AREA BY 06Z VIA AN ELEVATED MIXED LAYER. THE BETTER INSTABILITY IS DEFINITELY WEST OF THE AREA...AND THE BETTER DYNAMICS REMAIN NORTH OF THE AREA. WE DO SEE A SHORT WAVE ACROSS SD THAT APPROACHES THIS EVENING AND WILL LIKELY HELP TO SUPPORT CONVECTION OVER THE AREA. WE BELIEVE THAT THE SEVERE THREAT REMAINS POSSIBLE ACROSS THE AREA...ESPECIALLY ACROSS THE WRN HALF OF THE CWFA SIMILAR TO THE THINKING OF SPC PER THE SWODY1 OUTLOOK. DEEP LAYER SHEAR HAS TRENDED MORE FAVORABLE DURING THE EXPECTED TIME OF CONVECTION PEAKING AT AROUND 30-35 KNOTS...HIGHEST WEST WHERE THE BEST INSTABILITY WILL BE OVER THE AREA. LOW LEVEL INVERSION HEIGHTS ARE NOT EXPECTED TO BE ALL THAT HIGH...SO A WIND THREAT WILL BE POSSIBLE WITH 40 KNOTS IN THE MID LEVELS AND A 30+ KNOT LLJ PRESENT DURING THE TIME OF CONVECTION. LARGE HAIL WILL BE POSSIBLE WITH FAIRLY THICK CAPE IN THE -10C TO -30C LAYER. WE ALSO AGREE WITH SPC ABOUT THE POSSIBILITY OF A TORNADO WITH 0-1KM SHEAR OF 20-25 KNOTS AND 0-1KM HELICITY VALUES 150+ M2/S2. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 325 AM EDT TUE JUL 22 2014 OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE CONVECTIVE/SEVERE WX POTENTIAL THIS AFTERNOON THROUGH TONIGHT. IT WILL BE HOT AND HUMID TODAY WITH SOME SUN AND STRONG SSW FLOW WAA HELPING TO BOOST MAX TEMPS INTO THE 85 TO 90 DEGREE RANGE THIS AFTERNOON WITH DEW POINTS REACHING THE MID TO UPPER 60S. WE EXPECT SEVERE CONVECTION OVER MN AND EXTREME NW WI EARLY THIS MORNING TO TRACK ACROSS FAR NORTHERN WI AND THE U.P. THIS MORNING. HOWEVER THAT ACTIVITY WILL STAY WELL TO THE NW OF OUR FCST AREA. HOWEVER WE EXPECT A FEW SHOWERS AND TSTORMS TO DEVELOP OVER OUR FAR NW FCST AREA BY LATE AFTN AS THE COLD FRONT MOVES INTO THAT AREA. THE COLD FRONT WILL THEN MOVE QUICKLY ACROSS THE REST OF OUR FCST AREA DURING THE MID TO LATE EVENING HOURS BRINGING SCATTERED SHOWERS AND STORMS. ISOLATED STRONG TO MARGINALLY SEVERE STORMS ARE POSSIBLE MAINLY EARLY TO MID EVENING COINCIDENT WITH PEAK OR NEAR PEAK INSTABILITY WITH POTENTIAL FOR SB/ML CAPE VALUES TO BRIEFLY REACH UP TO AS HIGH AS 2000 J/KG FOR A SMALL PORTION OF OUR SOUTHWESTERN FCST AREA. SHORT RANGE GUIDANCE HAS ALSO TRENDED FASTER WITH FRONTAL TIMING THE PAST 24 HRS WHICH IS ALSO POTENTIALLY MORE FAVORABLE FOR A FEW STRONGER STORMS. THE MOST LIKELY TIME FRAME FOR CONVECTION IS FROM AROUND 23Z THIS EVENING THROUGH 05Z WEDNESDAY AS SUGGESTED BY 00Z 4KM NSSL WRF AND LATEST HRRR SIM Z GUIDANCE. HOWEVER IT IS NOTED THAT 0-6 KM BULK SHEAR IS WEAK AND MAINLY ONLY AROUND 20-25 KTS OFF LATEST SREF GUIDANCE... ALTHOUGH VERY BRIEFLY HIGHER VALUES ARE NOTED OVER OUR FAR NW FCST AREA. UPPER LEVEL SUPPORT FOR MORE ORGANIZED CONVECTIVE DEVELOPMENT PASSES BY WELL NORTH OF OUR FCST AREA. INSTABILITY IS FCST TO DIMINISH RATHER QUICKLY FROM MID TO LATE EVENING. SO THE OVERALL THREAT FOR SEVERE WX LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS IS RATHER LOW/MARGINAL. IT WILL BE BREEZY AND MUCH COOLER/DRIER WEDNESDAY WITH MAX TEMPS ONLY REACHING THE 70S. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM THE NW. HIGH PRESSURE WILL PRODUCE MOSTLY SUNNY SKIES THURSDAY WITH MAX TEMPS IN THE MID TO UPPER 70S. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 325 AM EDT TUE JUL 22 2014 THE MAIN CHALLENGE WITH THE LONG TERM FORECAST IS THE SHOWER AND TSTM POTENTIAL OVER THE COMING WEEKEND. GUIDANCE CONTINUES TO SUGGEST THAT THE PRIMARY CORRIDOR OF HEAVIER MCS ACTIVITY WILL BE SOUTHWEST/SOUTH OF MICHIGAN FRIDAY THROUGH SUNDAY... FROM ERN IOWA TO INDIANA. HOWEVER WE MAY STILL BE IMPACTED BY THE NRN PERIPHERY OF THESE CONVECTIVE COMPLEXES WITH PERIODS OF SHOWERS AND SCATTERED TSTMS...AIDED BY WEAK SHORTWAVES IN THE FAST W/NW FLOW ALOFT. A RATHER POTENT LOOKING SHORTWAVE IS PROGGED TO DROP DOWN FROM THE NORTHWEST SUNDAY NIGHT AND MONDAY... AND THE GFS/ECMWF ARE IN GOOD AGREEMENT ON THIS FEATURE. BEST POPS WILL EXIST DURING THIS PERIOD... FOLLOWED BY HIGH CONFIDENCE BELOW NORMAL TEMPERATURES BEHIND THIS SYSTEM FOR MOST OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 750 AM EDT TUE JUL 22 2014 THE PRIMARY AVIATION CONCERN FOR TODAY WILL BE THE INCREASING SOUTHWEST SFC WINDS WHICH WILL BE GUSTING TO 20-25 KNOTS AT MOST LOCATIONS BY NOON. STRONGEST GUSTS SHOULD BE AT MKG. THE FOCUS THIS EVENING FOR THE TERMINALS WILL BE THE LINE OF SCTD TSTMS WHICH MOVES SOUTHEAST THROUGH SRN LWR MI FROM 23Z-06Z. THE STORMS WILL IMPACT MKG FIRST AND JXN LAST... BUT ANY ONE LOCATION SHOULD ONLY SEE ABOUT A 2-4 HOUR WINDOW OF TSTMS IN THE VICINITY. A BRIEF PERIOD OF IFR IS POSSIBLE WITH ANY TSTM OTHERWISE LIGHT MVFR FOG/HAZE EXPECTED THIS EVENING DUE TO THE HIGH DEW POINTS NEAR 70 AHEAD OF THE APCHG COLD FRONT. STORMS WILL EXIT BY 06Z... BUT THE POTENTIAL FOR SOME MVFR CIGS WILL DEVELOP AFTER 09Z. SFC WINDS WILL SHIFT TO THE NORTH TONIGHT BEHIND THE COLD FRONT AND WILL PROBABLY REMAIN GUSTY AT TIMES... ESPECIALLY AT MKG. && .MARINE... ISSUED AT 325 AM EDT TUE JUL 22 2014 A SMALL CRAFT ADVISORY AND BEACH HAZARDS STATEMENT CONTINUES IN EFFECT FROM GRAND HAVEN NORTHWARD TODAY. WAVE HEIGHTS SHOULD REACH 3 TO 5 FEET WITH HIGHEST WAVES WITHIN THAT RANGE ANTICIPATED NORTH OF KMKG UP TOWARD THE POINTS. STRONGEST WINDS/HIGHEST WAVES WILL OCCUR FROM MID MORNING THROUGH MID EVENING. ANOTHER SMALL CRAFT AND BEACH HAZARDS STATEMENT WILL EVENTUALLY BE NEEDED FOR WEDNESDAY FOR STRONG NORTHERLY FLOW BEHIND THE COLD FRONT. THE HIGHEST WAVES WEDNESDAY WILL OCCUR SOUTH OF GRAND HAVEN. && .HYDROLOGY... ISSUED AT 334 PM EDT MON JUL 21 2014 WIDESPREAD SIGNIFICANT RAINFALL LOOKS UNLIKELY TUESDAY NIGHT AND WEDNESDAY. GENERALLY WE ARE EXPECTING A QUARTER TO THREE QUARTERS OF AN INCH OF RAINFALL WITH HIGHER AMOUNTS POSSIBLE IN HEAVIER THUNDERSTORMS. NOT ALL LOCATIONS ARE EXPECTED TO RECEIVE RAINFALL WITH THIS COLD FRONT. WITH A FAIRLY QUICK MOVING LINE OF CONVECTION ALONG THE FRONT...FLOODING IS A GREATLY MITIGATED THREAT. RIVERS HAVE BEEN FALLING STEADILY AND ASIDE FROM A TEMPORARY BUMP IN SOME LEVELS ON WEDNESDAY THIS TREND SHOULD CONTINUE FOR THE REST OF THE WEEK. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR MIZ037-043-050. LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ847>849. && $$ UPDATE...NJJ SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...MEADE AVIATION...MEADE HYDROLOGY...HOVING MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
751 AM EDT TUE JUL 22 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 325 AM EDT TUE JUL 22 2014 IT WILL BE VERY WARM AND QUITE HUMID TODAY. A COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND TONIGHT. A SIGNIFICANTLY COOLER AND DRIER AIR MASS WILL MOVE IN BEHIND THAT FRONT FOR MID TO LATE WEEK. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 325 AM EDT TUE JUL 22 2014 OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE CONVECTIVE/SEVERE WX POTENTIAL THIS AFTERNOON THROUGH TONIGHT. IT WILL BE HOT AND HUMID TODAY WITH SOME SUN AND STRONG SSW FLOW WAA HELPING TO BOOST MAX TEMPS INTO THE 85 TO 90 DEGREE RANGE THIS AFTERNOON WITH DEW POINTS REACHING THE MID TO UPPER 60S. WE EXPECT SEVERE CONVECTION OVER MN AND EXTREME NW WI EARLY THIS MORNING TO TRACK ACROSS FAR NORTHERN WI AND THE U.P. THIS MORNING. HOWEVER THAT ACTIVITY WILL STAY WELL TO THE NW OF OUR FCST AREA. HOWEVER WE EXPECT A FEW SHOWERS AND TSTORMS TO DEVELOP OVER OUR FAR NW FCST AREA BY LATE AFTN AS THE COLD FRONT MOVES INTO THAT AREA. THE COLD FRONT WILL THEN MOVE QUICKLY ACROSS THE REST OF OUR FCST AREA DURING THE MID TO LATE EVENING HOURS BRINGING SCATTERED SHOWERS AND STORMS. ISOLATED STRONG TO MARGINALLY SEVERE STORMS ARE POSSIBLE MAINLY EARLY TO MID EVENING COINCIDENT WITH PEAK OR NEAR PEAK INSTABILITY WITH POTENTIAL FOR SB/ML CAPE VALUES TO BRIEFLY REACH UP TO AS HIGH AS 2000 J/KG FOR A SMALL PORTION OF OUR SOUTHWESTERN FCST AREA. SHORT RANGE GUIDANCE HAS ALSO TRENDED FASTER WITH FRONTAL TIMING THE PAST 24 HRS WHICH IS ALSO POTENTIALLY MORE FAVORABLE FOR A FEW STRONGER STORMS. THE MOST LIKELY TIME FRAME FOR CONVECTION IS FROM AROUND 23Z THIS EVENING THROUGH 05Z WEDNESDAY AS SUGGESTED BY 00Z 4KM NSSL WRF AND LATEST HRRR SIM Z GUIDANCE. HOWEVER IT IS NOTED THAT 0-6 KM BULK SHEAR IS WEAK AND MAINLY ONLY AROUND 20-25 KTS OFF LATEST SREF GUIDANCE... ALTHOUGH VERY BRIEFLY HIGHER VALUES ARE NOTED OVER OUR FAR NW FCST AERA. UPPER LEVEL SUPPORT FOR MORE ORGANIZED CONVECTIVE DEVELOPMENT PASSES BY WELL NORTH OF OUR FCST AREA. INSTABILITY IS FCST TO DIMINISH RATHER QUICKLY FROM MID TO LATE EVENING. SO THE OVERALL THREAT FOR SEVERE WX LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS IS RATHER LOW/MARGINAL. IT WILL BE BREEZY AND MUCH COOLER/DRIER WEDNESDAY WITH MAX TEMPS ONLY REACHING THE 70S. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM THE NW. HIGH PRESSURE WILL PRODUCE MOSTLY SUNNY SKIES THURSDAY WITH MAX TEMPS IN THE MID TO UPPER 70S. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 325 AM EDT TUE JUL 22 2014 THE MAIN CHALLENGE WITH THE LONG TERM FORECAST IS THE SHOWER AND TSTM POTENTIAL OVER THE COMING WEEKEND. GUIDANCE CONTINUES TO SUGGEST THAT THE PRIMARY CORRIDOR OF HEAVIER MCS ACTIVITY WILL BE SOUTHWEST/SOUTH OF MICHIGAN FRIDAY THROUGH SUNDAY... FROM ERN IOWA TO INDIANA. HOWEVER WE MAY STILL BE IMPACTED BY THE NRN PERIPHERY OF THESE CONVECTIVE COMPLEXES WITH PERIODS OF SHOWERS AND SCATTERED TSTMS...AIDED BY WEAK SHORTWAVES IN THE FAST W/NW FLOW ALOFT. A RATHER POTENT LOOKING SHORTWAVE IS PROGGED TO DROP DOWN FROM THE NORTHWEST SUNDAY NIGHT AND MONDAY... AND THE GFS/ECMWF ARE IN GOOD AGREEMENT ON THIS FEATURE. BEST POPS WILL EXIST DURING THIS PERIOD... FOLLOWED BY HIGH CONFIDENCE BELOW NORMAL TEMPERATURES BEHIND THIS SYSTEM FOR MOST OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 750 AM EDT TUE JUL 22 2014 THE PRIMARY AVIATION CONCERN FOR TODAY WILL BE THE INCREASING SOUTHWEST SFC WINDS WHICH WILL BE GUSTING TO 20-25 KNOTS AT MOST LOCATIONS BY NOON. STRONGEST GUSTS SHOULD BE AT MKG. THE FOCUS THIS EVENING FOR THE TERMINALS WILL BE THE LINE OF SCTD TSTMS WHICH MOVES SOUTHEAST THROUGH SRN LWR MI FROM 23Z-06Z. THE STORMS WILL IMPACT MKG FIRST AND JXN LAST... BUT ANY ONE LOCATION SHOULD ONLY SEE ABOUT A 2-4 HOUR WINDOW OF TSTMS IN THE VICINITY. A BRIEF PERIOD OF IFR IS POSSIBLE WITH ANY TSTM OTHERWISE LIGHT MVFR FOG/HAZE EXPECTED THIS EVENING DUE TO THE HIGH DEW POINTS NEAR 70 AHEAD OF THE APCHG COLD FRONT. STORMS WILL EXIT BY 06Z... BUT THE POTENTIAL FOR SOME MVFR CIGS WILL DEVELOP AFTER 09Z. SFC WINDS WILL SHIFT TO THE NORTH TONIGHT BEHIND THE COLD FRONT AND WILL PROBABLY REMAIN GUSTY AT TIMES... ESPECIALLY AT MKG. && .MARINE... ISSUED AT 325 AM EDT TUE JUL 22 2014 A SMALL CRAFT ADVISORY AND BEACH HAZARDS STATEMENT CONTINUES IN EFFECT FROM GRAND HAVEN NORTHWARD TODAY. WAVE HEIGHTS SHOULD REACH 3 TO 5 FEET WITH HIGHEST WAVES WITHIN THAT RANGE ANTICIPATED NORTH OF KMKG UP TOWARD THE POINTS. STRONGEST WINDS/HIGHEST WAVES WILL OCCUR FROM MID MORNING THROUGH MID EVENING. ANOTHER SMALL CRAFT AND BEACH HAZARDS STATEMENT WILL EVENTUALLY BE NEEDED FOR WEDNESDAY FOR STRONG NORTHERLY FLOW BEHIND THE COLD FRONT. THE HIGHEST WAVES WEDNESDAY WILL OCCUR SOUTH OF GRAND HAVEN. && .HYDROLOGY... ISSUED AT 334 PM EDT MON JUL 21 2014 WIDESPREAD SIGNIFICANT RAINFALL LOOKS UNLIKELY TUESDAY NIGHT AND WEDNESDAY. GENERALLY WE ARE EXPECTING A QUARTER TO THREE QUARTERS OF AN INCH OF RAINFALL WITH HIGHER AMOUNTS POSSIBLE IN HEAVIER THUNDERSTORMS. NOT ALL LOCATIONS ARE EXPECTED TO RECEIVE RAINFALL WITH THIS COLD FRONT. WITH A FAIRLY QUICK MOVING LINE OF CONVECTION ALONG THE FRONT...FLOODING IS A GREATLY MITIGATED THREAT. RIVERS HAVE BEEN FALLING STEADILY AND ASIDE FROM A TEMPORARY BUMP IN SOME LEVELS ON WEDNESDAY THIS TREND SHOULD CONTINUE FOR THE REST OF THE WEEK. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR MIZ037-043-050. LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ847>849. && $$ SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...MEADE AVIATION...MEADE HYDROLOGY...HOVING MARINE...LAURENS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1038 AM CDT TUE JUL 22 2014 .DISCUSSION...COLD CORE LOW WILL CONTINUE TO RETROGRADE INTO THE ARKLAMISS FROM THE EAST THROUGH THE COURSE OF THE DAY. DEEPER MOISTURE FILTERING IN FROM THE EAST COMBINED WITH DAYTIME HEATING LOOKS TO YIELD CAPE VALUES AROUND 2000 J/KG THIS AFTERNOON WHICH IS ADEQUATE TO SUPPORT A DECENT COVERAGE OF CONVECTION THROUGH THE AFTERNOON HOURS...PARTICULARLY OVER AREAS ALONG AND EAST OF THE NATCHEZ TRACE PARKWAY WERE AN AXIS OF BETTER LOW LEVEL MOISTURE CONVERGENCE LOOKS TO EXIST. PRECIPITABLE H2O VALUES CLIMBING BACK UP TO THE 1.75-2.00 INCH RANGE WILL SUPPORT THE POTENTIAL FOR SOME LOCALIZED HEAVY RAINFALL. MODEST MID-LEVEL FLOW ON THE ORDER OF 30-35 KNOTS AND ADVERTISED 30 KNOTS 0-6KM BULK SHEAR COULD AID IN SOME HEALTHY CORES THIS AFTERNOON THAT`LL BE CAPABLE OF PRODUCING SOME GUSTY WINDS. THE LASTEST BATCH OF HIGH-RES MODELS SEEM TO BE PICKING UP ON THIS TREND AS THEIR CONVECTIVE OUTPUT IS A BIT MORE ROBUST THAN PREVIOUS RUNS. THIS ACTIVITY IS EXPECTED TO GRADUALLY SUBSIDE IN BOTH INTENSITY AND COVERAGE AS DAYTIME HEATING IS LOST THIS EVENING. THE ONLY NOTABLE CHANGES TO THE FORECAST FOR TODAY...ASIDE FROM THE TYPICAL HOURLY TRENDS...IS TO INCREASE POPS IN AREAS MAINLY ALONG AND EAST OF THE NATCHEZ TRACE PARKWAY. OTHERWISE...REMAINING ELEMENTS OF THE CURRENT FORECAST LOOK GOOD FOR TODAY. /19/ && .AVIATION...CONVECTION WILL INCREASE FROM THE EAST THIS AFTERNOOON... BUT NO MORE THAN VICINITY EXPECTED AT TAF SITES. SOME MVFR CEILINGS WILL BE POSSIBLE BETWEEN GTR AND MEI EARLY THIS AFTERNOON...OTHERWISE VFR CONDITIONS WILL PREVAIL INTO THE EVENING AS CONVECTION WINDS DOWN. THEREAFTER...MVFR CEILINGS IN THE EAST AND MVFR VISIBILITIES EVERYWHERE WILL BE THE RULE UNTIL AROUND 14Z. /26/ && .PREV DISCUSSION... /ISSUED 529 AM CDT TUE JUL 22 2014/ SHORT TERM...THE PRIMARY WEATHER FEATURE AFFECTING THE ARKLAMISS WILL BE A CLOSED COLD CORE LOW MIGRATING WESTWARD FROM AL INTO MS. THERE IS A WEAK SURFACE REFLECTION THAT WILL AID IN LOW LEVEL MOISTURE CONVERGENCE OVER EASTERN MS LATER THIS MORNING AND AFTERNOON AS DEEPER MOISTURE SURGES WESTWARD TOWARD THE INTERSTATE 55 CORRIDOR AND COMBINES WITH DAYTIME HEATING. HRRR GUIDANCE INDICATES CAPE VALUES PEAKING IN THE 2000-3000 J/KG RANGE AND PRECIPITABLE WATER APPROACHING TWO INCHES - AND THIS WILL SUPPORT THUNDERSTORM INITIATION ALONG THE LL MOISTURE CONVERGENCE AXIS STRETCHING NORTH OF THE LOW CENTER. HIGH-RES MODEL OUTPUT VARIES IN COVERAGE BUT THERE MAY BE SUFFICIENT EASTERLY MID LEVEL FLOW TO SUPPORT MULTI-CELL STORM CLUSTERS ALONG ANY BOUNDARIES WITH STORMS CAPABLE OF PRODUCING SOME STRONG WIND GUSTS. THE MOVEMENT OF STORMS IN THIS FLOW PATTERN WOULD INCREASE RAINFALL COVERAGE AND HAVE RAISED POPS SOME FOR TODAY. EXPECT CONVECTIVE ACTIVITY TO WANE AFTER SUNSET THIS EVENING. THE CLOSED LOW WILL CONTINUE ITS WESTWARD MIGRATION OVERNIGHT AND BETTER MOISTURE CONVERGENCE SHOULD SET UP FARTHER WEST WEDNESDAY...AND HAVE SHIFTED POPS SLIGHTLY IN THAT DIRECTION - A LITTLE MORE THAN MOS GUIDANCE SUGGESTS. THE THERMODYNAMIC AND WIND PROFILES SHOULD BE SIMILAR WEDNESDAY AND A FEW STRONG STORMS WOULD BE A POSSIBILITY ONCE AGAIN. IT LOOKS LIKE NORTHERN STREAM SHORTWAVE ENERGY APPROACHING THE AREA LATE WEDNESDAY NIGHT IS A LITTLE SLOWER IN THE MODEL GUIDANCE...AND THE GREATER INFLUENCE ON ARKLAMISS WEATHER MAY HOLD OFF UNTIL THURSDAY. HAVE RAISED POPS ABOVE GUIDANCE TO MAINTAIN SOME CONTINUITY...ESPECIALLY WITH THE POSSIBILITY OF CONVECTIVE COLD POOLS THAT COULD HELP TO SEND SHOWER/TSTM ACTIVITY A LITTLE FARTHER SOUTH THAN EXPECTED INTO NRN PORTIONS OF THE AREA. /EC/ LONG TERM...THURSDAY TO TUESDAY. SO FAR...NO BIG PATTERN CHANGE FOR THE REGION. WITH THE LARGE AREA OF HIGH PRESSURE PLANTED OVER THE ROCKIES...THE ARKLAMISS WILL CONTINUE TO GET FRONTS AND WEAK DISTURBANCES EVERY FEW DAYS. THE MOS CONTINUES TO BOUNCE AROUND WITH THE TEMPERATURES. PERHAPS LEANING MORE TOWARD CLIMATOLOGY FOR THIS TIME OF YEAR...THE TEMPS IN THE EXTENDED ARE BACK INTO THE UPPER 90S/MID 70S EARLY NEXT WEEK WHICH WOULD SUGGEST POSSIBLE INCREASE IN HEAT STRESS. HOWEVER...WITH THE CURRENT PATTERN TEMPERATURES ARE LIKELY TO BE AT OR BELOW NORMAL THROUGH THE EXTENDED. STUCK WITH GUIDANCE GENERALLY FOR POPS AND TEMPS. BY THURSDAY...IT LOOKS LIKE THE LATEST STALLED FRONT WILL BE REPLACED WITH AN APPROACHING COLD FRONT. THIS BOUNDARY IS LIKELY TO STALL ALONG THE COAST OVER THE WEEKEND...BEFORE THE NEXT FRONT MOVES INTO THE REGION AROUND MONDAY. EACH SYSTEM SEEMS TO BE LACKING MUCH UPPER LEVEL SUPPORT AND THE MAIN SURFACE LOW WITH EACH SYSTEM IS ALSO DISTANT. HOWEVER...THE MODELS ARE BRINGING IN PLENTY OF VERY MOIST AND UNSTABLE AIR FROM THE GULF. THERE IS A CHANCE OF RAIN ACROSS THE AREA NEARLY EVERY DAY. WITH THE BEST DYNAMICS ASSOCIATED WITH THE SYSTEMS STAYING TO THE NORTH AND THE WESTERN RIDGE WAVERING FURTHER EAST SOME DAYS...MUCH OF THE THUNDERSTORM ACTIVITY WILL MISS THE WESTERN ZONES...BASICALLY AREAS EAST OF INTERSTATE 55 THROUGH THE PERIOD. OF COURSE THERE COULD BE SOME ISOLATED TO SCATTERED THUNDERSTORMS...BUT POPS RIGHT NOW ARE LOW. BETWEEN EACH FRONT WILL BE A DAY OR TWO OF MOSTLY CLEAR SKIES AND MILD CONDITIONS. NOT ANTICIPATING A PATTERN SHIFT THIS FORECAST PERIOD. && .PRELIMINARY POINT TEMPS/POPS... JACKSON 90 71 91 71 / 46 32 34 22 MERIDIAN 88 69 91 69 / 60 39 28 23 VICKSBURG 90 70 92 71 / 20 20 34 22 HATTIESBURG 90 70 92 71 / 60 25 26 21 NATCHEZ 89 70 90 71 / 21 15 38 20 GREENVILLE 92 72 93 73 / 16 12 24 27 GREENWOOD 91 71 91 72 / 25 21 29 27 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 19/26
AREA FORECAST DISCUSSION
NWS JACKSON MS
529 AM CDT TUE JUL 22 2014 .SHORT TERM...THE PRIMARY WEATHER FEATURE AFFECTING THE ARKLAMISS WILL BE A CLOSED COLD CORE LOW MIGRATING WESTWARD FROM AL INTO MS. THERE IS A WEAK SURFACE REFLECTION THAT WILL AID IN LOW LEVEL MOISTURE CONVERGENCE OVER EASTERN MS LATER THIS MORNING AND AFTERNOON AS DEEPER MOISTURE SURGES WESTWARD TOWARD THE INTERSTATE 55 CORRIDOR AND COMBINES WITH DAYTIME HEATING. HRRR GUIDANCE INDICATES CAPE VALUES PEAKING IN THE 2000-3000 J/KG RANGE AND PRECIPITABLE WATER APPROACHING TWO INCHES - AND THIS WILL SUPPORT THUNDERSTORM INITIATION ALONG THE LL MOISTURE CONVERGENCE AXIS STRETCHING NORTH OF THE LOW CENTER. HIGH-RES MODEL OUTPUT VARIES IN COVERAGE BUT THERE MAY BE SUFFICIENT EASTERLY MID LEVEL FLOW TO SUPPORT MULTI-CELL STORM CLUSTERS ALONG ANY BOUNDARIES WITH STORMS CAPABLE OF PRODUCING SOME STRONG WIND GUSTS. THE MOVEMENT OF STORMS IN THIS FLOW PATTERN WOULD INCREASE RAINFALL COVERAGE AND HAVE RAISED POPS SOME FOR TODAY. EXPECT CONVECTIVE ACTIVITY TO WANE AFTER SUNSET THIS EVENING. THE CLOSED LOW WILL CONTINUE ITS WESTWARD MIGRATION OVERNIGHT AND BETTER MOISTURE CONVERGENCE SHOULD SET UP FARTHER WEST WEDNESDAY...AND HAVE SHIFTED POPS SLIGHTLY IN THAT DIRECTION - A LITTLE MORE THAN MOS GUIDANCE SUGGESTS. THE THERMODYNAMIC AND WIND PROFILES SHOULD BE SIMILAR WEDNESDAY AND A FEW STRONG STORMS WOULD BE A POSSIBILITY ONCE AGAIN. IT LOOKS LIKE NORTHERN STREAM SHORTWAVE ENERGY APPROACHING THE AREA LATE WEDNESDAY NIGHT IS A LITTLE SLOWER IN THE MODEL GUIDANCE...AND THE GREATER INFLUENCE ON ARKLAMISS WEATHER MAY HOLD OFF UNTIL THURSDAY. HAVE RAISED POPS ABOVE GUIDANCE TO MAINTAIN SOME CONTINUITY...ESPECIALLY WITH THE POSSIBILITY OF CONVECTIVE COLD POOLS THAT COULD HELP TO SEND SHOWER/TSTM ACTIVITY A LITTLE FARTHER SOUTH THAN EXPECTED INTO NRN PORTIONS OF THE AREA. /EC/ .LONG TERM...THURSDAY TO TUESDAY. SO FAR...NO BIG PATTERN CHANGE FOR THE REGION. WITH THE LARGE AREA OF HIGH PRESSURE PLANTED OVER THE ROCKIES...THE ARKLAMISS WILL CONTINUE TO GET FRONTS AND WEAK DISTURBANCES EVERY FEW DAYS. THE MOS CONTINUES TO BOUNCE AROUND WITH THE TEMPERATURES. PERHAPS LEANING MORE TOWARD CLIMATOLOGY FOR THIS TIME OF YEAR...THE TEMPS IN THE EXTENDED ARE BACK INTO THE UPPER 90S/MID 70S EARLY NEXT WEEK WHICH WOULD SUGGEST POSSIBLE INCREASE IN HEAT STRESS. HOWEVER...WITH THE CURRENT PATTERN TEMPERATURES ARE LIKELY TO BE AT OR BELOW NORMAL THROUGH THE EXTENDED. STUCK WITH GUIDANCE GENERALLY FOR POPS AND TEMPS. BY THURSDAY...IT LOOKS LIKE THE LATEST STALLED FRONT WILL BE REPLACED WITH AN APPROACHING COLD FRONT. THIS BOUNDARY IS LIKELY TO STALL ALONG THE COAST OVER THE WEEKEND...BEFORE THE NEXT FRONT MOVES INTO THE REGION AROUND MONDAY. EACH SYSTEM SEEMS TO BE LACKING MUCH UPPER LEVEL SUPPORT AND THE MAIN SURFACE LOW WITH EACH SYSTEM IS ALSO DISTANT. HOWEVER...THE MODELS ARE BRINGING IN PLENTY OF VERY MOIST AND UNSTABLE AIR FROM THE GULF. THERE IS A CHANCE OF RAIN ACROSS THE AREA NEARLY EVERY DAY. WITH THE BEST DYNAMICS ASSOCIATED WITH THE SYSTEMS STAYING TO THE NORTH AND THE WESTERN RIDGE WAVERING FURTHER EAST SOME DAYS...MUCH OF THE THUNDERSTORM ACTIVITY WILL MISS THE WESTERN ZONES...BASICALLY AREAS EAST OF INTERSTATE 55 THROUGH THE PERIOD. OF COURSE THERE COULD BE SOME ISOLATED TO SCATTERED THUNDERSTORMS...BUT POPS RIGHT NOW ARE LOW. BETWEEN EACH FRONT WILL BE A DAY OR TWO OF MOSTLY CLEAR SKIES AND MILD CONDITIONS. NOT ANTICIPATING A PATTERN SHIFT THIS FORECAST PERIOD. && .AVIATION...PATCHY AREAS OF FOG WILL MIX OUT QUICKLY AFTER SUNRISE THIS MORNING AND VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH TONIGHT. INCREASINGLY MOIST AND UNSTABLE AIR WILL SUPPORT BETTER AFTERNOON SHRA/TSRA COVERAGE...ESPECIALLY ALONG AND EAST OF THE GWO/JAN/MCB CORRIDOR. /EC/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 90 71 91 71 / 34 32 34 22 MERIDIAN 89 69 91 69 / 52 39 28 23 VICKSBURG 90 70 92 71 / 20 20 34 22 HATTIESBURG 90 70 92 71 / 41 25 26 21 NATCHEZ 89 70 90 71 / 21 15 38 20 GREENVILLE 92 72 93 73 / 15 12 24 27 GREENWOOD 91 71 91 72 / 25 21 29 27 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ EC/07/
AREA FORECAST DISCUSSION
NWS HASTINGS NE
653 AM CDT TUE JUL 22 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 501 AM CDT TUE JUL 22 2014 IN SHORT...THERE ARE TWO MAIN CONCERNS THROUGH THE NEXT 24 HOURS...ONE BEING ANOTHER DAY OF AT LEAST MARGINALLY-ADVISORY LEVEL HEAT INDEX VALUES ACROSS ROUGHLY THE SOUTHEAST 1/2 OF THE CWA...AND THE OTHER BEING WHETHER OR NOT A FEW ISOLATED STORM/POSSIBLY A BROKEN LINE OF STORMS CAN FLARE UP AND BECOME STRONG TO SEVERE GENERALLY NEAR/SOUTH OF THE STATE LINE LATE THIS AFTERNOON INTO THIS EVENING ALONG A SURFACE COLD FRONT. BOTH BEFORE AND AFTER THIS MAIN TIME FRAME OF CONCERN FOR POSSIBLE STRONG CONVECTION...AT LEAST ISOLATED CONVECTION CANNOT BE COMPLETELY RULED OUT. STARTING WITH THIS MORNING...SUPPOSE A FEW ROGUE SHOWERS/POSSIBLY A WEAK ELEVATED STORM SLIPPING INTO MAINLY NORTHERN PORTIONS OF THE CWA IS NOT OUT OF THE QUESTION...BUT CONFIDENCE IN THIS OCCURRING IS NOT HIGH ENOUGH TO INTRODUCE A FORMAL MENTION INTO A PREVIOUSLY-DRY FORECAST. THEN LATE TONIGHT...GENERALLY AFTER MIDNIGHT...CONFIDENCE IS VERY LOW ON WHAT WILL TRANSPIRE...AS SOME MODELS SHOW POTENTIALLY WIDESPREAD CONVECTION DEVELOPING OVER OR MOVING INTO PRIMARILY THE SOUTHWEST 1/2 OF THE CWA...WHILE OTHERS ARE BONE DRY. STARTING WITH THE HERE AND NOW AS OF 09Z/4 AM...DRY CONDITIONS ARE IN PLACE OVER THE CWA...WHILE AT LEAST A FEW COUNTIES OUTSIDE THE LOCAL AREA A SMATTERING OF WEAK ELEVATED THUNDERSTORMS ARE ROAMING PARTS OF WESTERN/NORTH CENTRAL NEB AND ALSO A SMALL PORTION OF WEST CENTRAL IA. THE ACTIVITY TO THE NORTH AND WEST APPEARS TO BE TIED MAINLY TO AN EAST-WEST ORIENTED ZONE OF FRONTOGENESIS IN THE 850-700MB LAYER. IN THE BIGGER PICTURE...WATER VAPOR SATELLITE IMAGERY ALONG WITH SHORT TERM MODEL DATA HIGHLIGHT THE EXPANSIVE HIGH/ANTICYCLONE EXTENDING EASTWARD INTO THE CENTRAL PLAINS FROM ITS CENTRAL CORE OVER THE NM/CO BORDER AREA. IN THE STRONGER FLOW TO THE THE NORTH...A VIGOROUS SHORTWAVE TROUGH WAS TRACKING EASTWARD ACROSS NORTHERN MN. ESSENTIALLY...THE LOCAL AREA LIES ALONG THE INTERFACE BETWEEN VERY WEAK MID/UPPER FLOW TO THE SOUTH AND SOMEWHAT STRONGER WESTERLY FLOW JUST TO THE NORTH ALONG THE FRINGES OF THE RIDGE AXIS. AT THE SURFACE...HIGH PRESSURE CENTERED OFF TO THE NORTH IN THE WAKE OF THE NORTHERN MN SHORTWAVE TROUGH HAS PUSHED A MODEST COLD FRONT SOUTHWARD INTO NEBRASKA OVERNIGHT...WITH ITS LEADING EDGE ALREADY WORKING INTO NORTHERN PORTIONS OF THE CWA AS EVIDENCED BY A SHIFT TO SOME NORTHERLY WIND COMPONENT...WHILE THE MAJORITY OF THE CWA HAS OBSERVED SOME VARIATION OF SOUTHERLY TO WESTERLY BREEZES IN THE 5-15 MPH RANGE OVERNIGHT. ALTHOUGH SOME DRIER LOW- 60S DEWPOINTS HAVE ADVECTED INTO WESTERN ZONES OVERNIGHT...MUCH OF THE EASTERN CWA CONTINUES HOLDING ONTO UPPER 60S-LOW 70S DEWPOINTS...MAKING FOR ANOTHER SEASONABLY WARM MORNING. LOW TEMPS WILL LIKELY EXHIBIT A RANGE FROM UPPER 60S/NEAR-70 WEST TO UPPER 70S-NEAR 80 EAST GIVEN THIS DEWPOINT GRADIENT. HEADING INTO THE DAYTIME HOURS...THE BIG PICTURE ALOFT INVOLVES A TRANSITION FROM MORE WESTERLY TO MORE NORTHERLY MID-UPPER LEVEL FLOW...IN RESPONSE TO THE EXPANSIVE RIDGE EDGING SLIGHTLY NORTH MORE OVER CO...AND THE NORTHEAST EDGE OF THIS RIDGE AXIS CLOSER TO THE LOCAL AREA BEING FLATTENED SOMEWHAT IN THE WAKE OF THE DEPARTING GREAT LAKES AREA TROUGH. MEANWHILE AT THE SURFACE...THE COLD FRONT WILL CONTINUE SINKING SOUTHWARD ACROSS THE AREA AS HIGH PRESSURE SHIFTS EASTWARD ACROSS THE DAKOTAS/MN AREA. ALTHOUGH THE SOUTHWARD PUSH OF THIS FRONT SHOULD EASE WITH TIME...MOST OF SOUTH CENTRAL NEBRASKA SHOULD OBSERVE PREVAILING NORTHEAST BREEZES UP TO AROUND 10-15 MPH THROUGH MOST OF THE DAY...WHILE LOCATIONS NEAR THE STALLING SOUTHERN EDGE OF THIS BOUNDARY NEAR AND SOUTH OF THE STATE LINE WILL OBSERVE A LIGHT/VARIABLE TO LIGHT SOUTHERLY BREEZE AS THE FRONT IS REINFORCED NEAR THE STATE LINE IN RESPONSE TO WEAK LOW PRESSURE CENTERED NEAR THE CO/KS BORDER. ALTHOUGH VERY WARM MID LEVEL TEMPS ON THE ORDER OF 13-15C AT 700MB SHOULD CONTINUE TO FIRMLY CAP LOW-LEVEL BASED CONVECTION THROUGH AT LEAST THE MAJORITY OF THE DAY...THERE ARE HINTS THAT A FEW ELEVATED SPRINKLES OR EVEN WEAK STORMS COULD PERCOLATE ABOVE THE CAP ALONG THE ELEVATED FRONTAL ZONE MAINLY THIS MORNING...AND WILL HAVE TO KEEP AN EYE OUT IN CASE SOME LOW POPS MIGHT NEED ADDED TO MAINLY THE NORTHERN CWA. OTHERWISE...THE MAIN FOCUS FOR POTENTIALLY MORE NOTEWORTHY AND LOWER-BASED CONVECTION SHOULD HOLD OFF UNTIL LATE AFTERNOON/EARLY EVENING NEARER THE SURFACE FRONT NEAR THE STATE LINE. ALTHOUGH THIS DEVELOPMENT IS CERTAINLY NO GUARANTEE GIVEN THE STRONG CAP...THE HOT/DEEPLY MIXED AIRMASS SOUTH OF THE FRONT MAY BE ENOUGH TO TRIGGER AT LEAST ISOLATED CONVECTION IN AN ENVIRONMENT CHARACTERIZED BY AROUND 2000-3000 J/KG MIXED LAYER CAPE BUT ONLY AROUND 25KT AT MOST OF DEEP LAYER SHEAR. SOME MODELS ARE MORE AGGRESSIVE WITH OTHERS IN THIS STORM DEVELOPMENT...AS FOR EXAMPLE THE 00Z 4KM NSSL WRF STRONGLY SUGGESTS IT WHILE THE LATEST 08Z RAP KEEPS STORMS AT BY LOCALLY THROUGH AT LEAST 02Z/9PM. AT ANY RATE...MAINTAINED THE SLIGHT POPS FOR LATE THIS AFTERNOON/THIS EVENING TO COVER AT LEAST THE POSSIBILITY OF THIS DEVELOPMENT ALONG THE EAST-WEST FRONTAL ZONE. DESPITE THE VERY CONDITIONAL NATURE OF THIS STORM DEVELOPMENT...THE STORM PREDICTION CENTER UPGRADED MUCH OF THE SOUTHERN CWA TO A SLIGHT RISK ON THE DAY 1 OUTLOOK...WITH THE MAIN THREATS LIKELY BEING STRONG OUTFLOW WINDS/DOWNBURST ACTIVITY...AND LESS-SO LARGE HAIL GIVEN SUCH WARM THERMAL PROFILES. SPEAKING OF THERMAL...TEMPERATURES AND DEWPOINTS HAVE BEEN A BIT OF A CHALLENGE FOR TODAY...AS MUCH OF THIS DEPENDS ON HOW FAST THE SLIGHTLY COOLER AIR CAN FILTER IN FROM THE NORTH TODAY...AND WHETHER DEWPOINTS AGAIN SPIKE BACK UP BEHIND THIS BOUNDARY AFTER FALLING OFF SOMEWHAT OVERNIGHT. TOOK A BEST STAB AT HIGHS USING A BLEND OF VARIOUS MODELS...YIELDING A RANGE FROM LOW 90S FAR NORTH...MID 90S CENTRAL AND GENERALLY 100-102 IN KS ZONES. WOULD NOT BE SURPRISED THOUGH TO SEE PARTS OF THE NORTH STAY A FEW DEGREES COOLER AND PARTS OF THE SOUTH RISE A FEW DEGREES HIGHER. THE NET RESULT FOR HEAT INDEX VALUES IS THAT AREAS MAINLY SOUTH OF A YORK-MINDEN LINE (INCLUDING KS) APPEAR MOST FAVORED TO REACH/SLIGHTLY EXCEED 105...AND THUS HAVE GONE WITH AN ADVISORY FOR THESE LOCATIONS ALTHOUGH DO NOT EXPECT AS MUCH OF THE HIGHER- THAN-EXPECTED COVERAGE OF 110+ HEAT INDEX READINGS THAT MATERIALIZED YESTERDAY IN EASTERN ZONES. OUTSIDE THE ADVISORY AREA TO THE NORTH AND WEST...IT WILL OBVIOUSLY STILL BE HOT...BUT LOOKING FOR SUB-ADVISORY LEVEL HEAT INDEX VALUES MORE INTO THE 95-102 RANGE. FOR THIS EVENING/TONIGHT...OBVIOUSLY HEAT INDEX/ADVISORY ISSUES WILL QUICKLY ABATE...LEAVING THE ULTIMATE QUESTION AS TO HOW MUCH IF ANY CONVECTION AND POSSIBLE STRONG-SEVERE STORM POTENTIAL REMAINS THROUGH THE NIGHT. AS FOR THE BIG PICTURE OF THE MID-UPPER LEVELS...FLOW WILL TURN EVEN MORE NORTHERLY AS THE STRONG HIGH PRESSURE CENTER PARKS ITSELF FIRMLY OVER CENTRAL CO...WHICH ACTUALLY ALLOWS MID LEVEL TEMPS TO COOL VERY SLIGHTLY OVER THE LOCAL AREA AS A LOW-AMPLITUDE SHORTWAVE TROUGH BRUSHES BY ALONG A TRACK FROM THE DAKOTAS INTO IA OVERNIGHT. AT THE SURFACE...GENERALLY EAST- NORTHEAST BREEZES AROUND 10 MPH WILL PREVAIL OVERNIGHT AS HIGH PRESSURE REMAINS CENTERED WELL OFF TO THE NORTHEAST OF THE LOCAL AREA. AS MENTIONED ABOVE...THERE IS TREMENDOUS UNCERTAINTY IN THE CONVECTIVE POTENTIAL OVERNIGHT. ONE SCENARIO IS THAT ONCE ANY EVENING ACTIVITY DIES OUT OR MOVES OUT OF THE AREA IN THE SOUTHERN CWA ALONG THE FRONTAL ZONE THAT NOTHING ELSE OCCURS THE REST OF THE NIGHT (PER THE ECMWF AND ALSO THE NSSL 4KM-WRF). MEANWHILE...OTHER MODELS SUCH AS THE NAM/GFS AND ALSO THE 4KM WRF-NMM SIMULATED REFLECTIVITY SHOW POTENTIALLY A FAIR AMOUNT OF CONVECTION AFFECTING MAINLY THE SOUTHWEST HALF OF THE CWA AFTER MIDNIGHT...POSSIBLY AS A RESULT OF A STORM COMPLEX RIDING SOUTHEASTWARD INTO THE AREA OUT OF THE BLACK HILLS/NORTHWEST NEB AREA. GIVEN THE TREMENDOUS UNCERTAINTY HERE...OPTED NOT TO GET CUTE WITH THE FORECAST AND JUST BLANKETED MUCH OF THE CENTRAL/SOUTHERN CWA WITH A GENERIC SLIGHT 20 PERCENT POP FOR THE LATER NIGHT HOURS. BESIDES CONVECTIVE POTENTIAL...SUPPOSE AT LEAST SOME LIGHT FOG CANNOT BE RULED OUT LATE TONIGHT MAINLY IN WESTERN ZONES...BUT CURRENT MODELS/GUIDANCE DO NOT SUPPORT VISIBILITY RESTRICTIONS BAD ENOUGH/WIDESPREAD ENOUGH FOR A FORMAL FORECAST INCLUSION AT THIS TIME. AS FOR LOW TEMPS...ONLY MADE MINOR TWEAKS AIMING FOR A RANGE FROM MID 60S NORTH TO AROUND 70 SOUTH. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 501 AM CDT TUE JUL 22 2014 TEMPS WILL BE UP AND DOWN DURING THE EXTENDED PERIODS AND ALTHOUGH THERE ARE HIT OR MISS CHCS FOR TSTMS...NOTHING IS LOOKING WIDESPREAD OR SIGNIFICANT AT THIS POINT IN TIME. FOLLOWING THE REALLY HOT TEMPERATURES MONDAY AND TUESDAY...READINGS WILL TREND COOLER ON WEDNESDAY AS THE UPPER RIDGE AXIS RETROGRADES ALONG THE HIGH PLAINS AND A TROUGH DEEPENS FM THE GREAT LAKES THRU THE OHIO VALLEY REGION. THE HOT AIR RETREATS AND COOLER AIR BACKS IN FROM THE EAST AND H85 TEMPS COOL SEVERAL DEGREES AND WE ARE LOOKING FOR AFTERNOON HIGHS TO RANGE FROM THE MID 80S IN OUR EASTERN ZONES TO AROUND 90F IN THE SW. A 1020MB SFC HIGH PRESSURE SYSTEM BUILDS SOUTH FROM THE UPPER MIDWEST WHICH WILL RESULT IN EASTERLY LLVL FLOW AND BRING THE COOLEST CONDITIONS TO OUR EASTERN ZONES. HAVE KEPT THE FORECAST DRY BUT THERE IS AN OUTSIDE CHC FOR REMNANT CONVECTION TO LINGER FOR A TIME WEDNESDAY MORNING IN THE VCNTY OF THE FRONTAL BOUNDARY IN OUR SOUTH. TEMPERATURES WILL BE ON THE INCREASE AGAIN THURSDAY FRIDAY AS THE UPPER RIDGE AXIS BUILDS EAST AGAIN AHEAD OF AN UPPER LOW TRANSLATING EAST FROM THE PACIFIC NORTHWEST. THE RIDGE AXIS DEAMPLIFIES BY THE END OF THE WEEK BUT THE AIRMASS REMAINS QUITE WARM THRU FRIDAY AND HIGH TEMPERATURES SHOULD AGAIN AVERAGE IN THE 90S. A PROGRESSING MID LEVEL SHORTWAVE TROUGH AND WAA AHEAD OF THE SYSTEM WILL BRING THE POTENTIAL FOR TSTMS THURSDAY AND THURSDAY NIGHT. THEN...A COLD FRONT ASSOCIATED WITH THE NORTHERN CONUS SYSTEM PUSHES SOUTHEAST DURING THE DAY ON FRIDAY BUT CHCS FOR STORMS LOOK NEGLIGIBLE WITH THE BOUNDARY. OVER THE WEEKEND AND EARLY NEXT WEEK THE UPPER RIDGE RETROGRADES AND BUILDS OVER THE ROCKIES WHILE AN UPPER TROUGH DEEPENS FM THE GREAT LAKES THROUGH THE OHIO VALLEY. COOLER AIR WILL RETURN IN THE MORE MERIDIONAL FLOW AND TEMPERATURES WILL DROP BACK CLOSER TO SEASONAL READINGS OR BELOW. CANNOT COMPLETELY RULE OUT PCPN CHCS IN THE OUTER PERIODS AS TEMPERATURES COOL ALOFT AND BOUNDARIES MOVE THRU. THIS BEING SAID NOTHING SAID THERE IS NO REAL CONCLUSIVE PERIOD FOR CONVECTION EITHER AND HAVE ONLY CARRIED LOW POPS IN OUR SOUTH FOR SUNDAY NIGHT. && .AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z WEDNESDAY) ISSUED AT 653 AM CDT TUE JUL 22 2014 CONFIDENCE IS FAIRLY HIGH IN VFR CEILING/VISIBILITY PERSISTING THROUGH THE PERIOD UNDER FAIRLY LIMITED COVERAGE OF MID-HIGH CLOUDS. ALTHOUGH NOT ZERO...THE CHANCES OF ANY SHOWERS/THUNDERSTORMS AFFECTING THE TERMINALS SEEMS TO BE NO HIGHER THAN 10-20 PERCENT...AND THUS CANNOT EVEN JUSTIFY A VICINITY THUNDERSTORM (VCTS) MENTION AT THIS TIME. IF ANY STORMS WERE HAPPEN TO BECOME AN ISSUE...IT WOULD LIKELY BE LATE TONIGHT DURING THE LATTER 6 HOURS OF THE PERIOD. SUSTAINED SURFACE BREEZES ARE EXPECTED TO AVERAGE AT/UNDER 12KT THROUGH THE MAJORITY OF THE PERIOD...ALTHOUGH SOME BRIEF PERIODS OF ENHANCED GUSTINESS UP TO AROUND 20KT CANNOT BE RULED OUT MAINLY THIS MORNING. ALTHOUGH A WEST-NORTHWEST WIND DIRECTION MAY HOLD ON FOR A FEW HOURS INITIALLY THIS MORNING...A PASSING COLD FRONT SHOULD SOON RESULT IN PREVAILING NORTHEAST BREEZES THAT ARE EXPECTED TO PERSIST THROUGH THE REMAINDER OF THE PERIOD. && .GID WATCHES/WARNINGS/ADVISORIES... NE...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR NEZ064-074>077-083>087. KS...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR KSZ005>007-017>019. && $$ SHORT TERM...PFANNKUCH LONG TERM...FAY AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
502 AM CDT TUE JUL 22 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 501 AM CDT TUE JUL 22 2014 IN SHORT...THERE ARE TWO MAIN CONCERNS THROUGH THE NEXT 24 HOURS...ONE BEING ANOTHER DAY OF AT LEAST MARGINALLY-ADVISORY LEVEL HEAT INDEX VALUES ACROSS ROUGHLY THE SOUTHEAST 1/2 OF THE CWA...AND THE OTHER BEING WHETHER OR NOT A FEW ISOLATED STORM/POSSIBLY A BROKEN LINE OF STORMS CAN FLARE UP AND BECOME STRONG TO SEVERE GENERALLY NEAR/SOUTH OF THE STATE LINE LATE THIS AFTERNOON INTO THIS EVENING ALONG A SURFACE COLD FRONT. BOTH BEFORE AND AFTER THIS MAIN TIME FRAME OF CONCERN FOR POSSIBLE STRONG CONVECTION...AT LEAST ISOLATED CONVECTION CANNOT BE COMPLETELY RULED OUT. STARTING WITH THIS MORNING...SUPPOSE A FEW ROGUE SHOWERS/POSSIBLY A WEAK ELEVATED STORM SLIPPING INTO MAINLY NORTHERN PORTIONS OF THE CWA IS NOT OUT OF THE QUESTION...BUT CONFIDENCE IN THIS OCCURRING IS NOT HIGH ENOUGH TO INTRODUCE A FORMAL MENTION INTO A PREVIOUSLY-DRY FORECAST. THEN LATE TONIGHT...GENERALLY AFTER MIDNIGHT...CONFIDENCE IS VERY LOW ON WHAT WILL TRANSPIRE...AS SOME MODELS SHOW POTENTIALLY WIDESPREAD CONVECTION DEVELOPING OVER OR MOVING INTO PRIMARILY THE SOUTHWEST 1/2 OF THE CWA...WHILE OTHERS ARE BONE DRY. STARTING WITH THE HERE AND NOW AS OF 09Z/4 AM...DRY CONDITIONS ARE IN PLACE OVER THE CWA...WHILE AT LEAST A FEW COUNTIES OUTSIDE THE LOCAL AREA A SMATTERING OF WEAK ELEVATED THUNDERSTORMS ARE ROAMING PARTS OF WESTERN/NORTH CENTRAL NEB AND ALSO A SMALL PORTION OF WEST CENTRAL IA. THE ACTIVITY TO THE NORTH AND WEST APPEARS TO BE TIED MAINLY TO AN EAST-WEST ORIENTED ZONE OF FRONTOGENESIS IN THE 850-700MB LAYER. IN THE BIGGER PICTURE...WATER VAPOR SATELLITE IMAGERY ALONG WITH SHORT TERM MODEL DATA HIGHLIGHT THE EXPANSIVE HIGH/ANTICYCLONE EXTENDING EASTWARD INTO THE CENTRAL PLAINS FROM ITS CENTRAL CORE OVER THE NM/CO BORDER AREA. IN THE STRONGER FLOW TO THE THE NORTH...A VIGOROUS SHORTWAVE TROUGH WAS TRACKING EASTWARD ACROSS NORTHERN MN. ESSENTIALLY...THE LOCAL AREA LIES ALONG THE INTERFACE BETWEEN VERY WEAK MID/UPPER FLOW TO THE SOUTH AND SOMEWHAT STRONGER WESTERLY FLOW JUST TO THE NORTH ALONG THE FRINGES OF THE RIDGE AXIS. AT THE SURFACE...HIGH PRESSURE CENTERED OFF TO THE NORTH IN THE WAKE OF THE NORTHERN MN SHORTWAVE TROUGH HAS PUSHED A MODEST COLD FRONT SOUTHWARD INTO NEBRASKA OVERNIGHT...WITH ITS LEADING EDGE ALREADY WORKING INTO NORTHERN PORTIONS OF THE CWA AS EVIDENCED BY A SHIFT TO SOME NORTHERLY WIND COMPONENT...WHILE THE MAJORITY OF THE CWA HAS OBSERVED SOME VARIATION OF SOUTHERLY TO WESTERLY BREEZES IN THE 5-15 MPH RANGE OVERNIGHT. ALTHOUGH SOME DRIER LOW- 60S DEWPOINTS HAVE ADVECTED INTO WESTERN ZONES OVERNIGHT...MUCH OF THE EASTERN CWA CONTINUES HOLDING ONTO UPPER 60S-LOW 70S DEWPOINTS...MAKING FOR ANOTHER SEASONABLY WARM MORNING. LOW TEMPS WILL LIKELY EXHIBIT A RANGE FROM UPPER 60S/NEAR-70 WEST TO UPPER 70S-NEAR 80 EAST GIVEN THIS DEWPOINT GRADIENT. HEADING INTO THE DAYTIME HOURS...THE BIG PICTURE ALOFT INVOLVES A TRANSITION FROM MORE WESTERLY TO MORE NORTHERLY MID-UPPER LEVEL FLOW...IN RESPONSE TO THE EXPANSIVE RIDGE EDGING SLIGHTLY NORTH MORE OVER CO...AND THE NORTHEAST EDGE OF THIS RIDGE AXIS CLOSER TO THE LOCAL AREA BEING FLATTENED SOMEWHAT IN THE WAKE OF THE DEPARTING GREAT LAKES AREA TROUGH. MEANWHILE AT THE SURFACE...THE COLD FRONT WILL CONTINUE SINKING SOUTHWARD ACROSS THE AREA AS HIGH PRESSURE SHIFTS EASTWARD ACROSS THE DAKOTAS/MN AREA. ALTHOUGH THE SOUTHWARD PUSH OF THIS FRONT SHOULD EASE WITH TIME...MOST OF SOUTH CENTRAL NEBRASKA SHOULD OBSERVE PREVAILING NORTHEAST BREEZES UP TO AROUND 10-15 MPH THROUGH MOST OF THE DAY...WHILE LOCATIONS NEAR THE STALLING SOUTHERN EDGE OF THIS BOUNDARY NEAR AND SOUTH OF THE STATE LINE WILL OBSERVE A LIGHT/VARIABLE TO LIGHT SOUTHERLY BREEZE AS THE FRONT IS REINFORCED NEAR THE STATE LINE IN RESPONSE TO WEAK LOW PRESSURE CENTERED NEAR THE CO/KS BORDER. ALTHOUGH VERY WARM MID LEVEL TEMPS ON THE ORDER OF 13-15C AT 700MB SHOULD CONTINUE TO FIRMLY CAP LOW-LEVEL BASED CONVECTION THROUGH AT LEAST THE MAJORITY OF THE DAY...THERE ARE HINTS THAT A FEW ELEVATED SPRINKLES OR EVEN WEAK STORMS COULD PERCOLATE ABOVE THE CAP ALONG THE ELEVATED FRONTAL ZONE MAINLY THIS MORNING...AND WILL HAVE TO KEEP AN EYE OUT IN CASE SOME LOW POPS MIGHT NEED ADDED TO MAINLY THE NORTHERN CWA. OTHERWISE...THE MAIN FOCUS FOR POTENTIALLY MORE NOTEWORTHY AND LOWER-BASED CONVECTION SHOULD HOLD OFF UNTIL LATE AFTERNOON/EARLY EVENING NEARER THE SURFACE FRONT NEAR THE STATE LINE. ALTHOUGH THIS DEVELOPMENT IS CERTAINLY NO GUARANTEE GIVEN THE STRONG CAP...THE HOT/DEEPLY MIXED AIRMASS SOUTH OF THE FRONT MAY BE ENOUGH TO TRIGGER AT LEAST ISOLATED CONVECTION IN AN ENVIRONMENT CHARACTERIZED BY AROUND 2000-3000 J/KG MIXED LAYER CAPE BUT ONLY AROUND 25KT AT MOST OF DEEP LAYER SHEAR. SOME MODELS ARE MORE AGGRESSIVE WITH OTHERS IN THIS STORM DEVELOPMENT...AS FOR EXAMPLE THE 00Z 4KM NSSL WRF STRONGLY SUGGESTS IT WHILE THE LATEST 08Z RAP KEEPS STORMS AT BY LOCALLY THROUGH AT LEAST 02Z/9PM. AT ANY RATE...MAINTAINED THE SLIGHT POPS FOR LATE THIS AFTERNOON/THIS EVENING TO COVER AT LEAST THE POSSIBILITY OF THIS DEVELOPMENT ALONG THE EAST-WEST FRONTAL ZONE. DESPITE THE VERY CONDITIONAL NATURE OF THIS STORM DEVELOPMENT...THE STORM PREDICTION CENTER UPGRADED MUCH OF THE SOUTHERN CWA TO A SLIGHT RISK ON THE DAY 1 OUTLOOK...WITH THE MAIN THREATS LIKELY BEING STRONG OUTFLOW WINDS/DOWNBURST ACTIVITY...AND LESS-SO LARGE HAIL GIVEN SUCH WARM THERMAL PROFILES. SPEAKING OF THERMAL...TEMPERATURES AND DEWPOINTS HAVE BEEN A BIT OF A CHALLENGE FOR TODAY...AS MUCH OF THIS DEPENDS ON HOW FAST THE SLIGHTLY COOLER AIR CAN FILTER IN FROM THE NORTH TODAY...AND WHETHER DEWPOINTS AGAIN SPIKE BACK UP BEHIND THIS BOUNDARY AFTER FALLING OFF SOMEWHAT OVERNIGHT. TOOK A BEST STAB AT HIGHS USING A BLEND OF VARIOUS MODELS...YIELDING A RANGE FROM LOW 90S FAR NORTH...MID 90S CENTRAL AND GENERALLY 100-102 IN KS ZONES. WOULD NOT BE SURPRISED THOUGH TO SEE PARTS OF THE NORTH STAY A FEW DEGREES COOLER AND PARTS OF THE SOUTH RISE A FEW DEGREES HIGHER. THE NET RESULT FOR HEAT INDEX VALUES IS THAT AREAS MAINLY SOUTH OF A YORK-MINDEN LINE (INCLUDING KS) APPEAR MOST FAVORED TO REACH/SLIGHTLY EXCEED 105...AND THUS HAVE GONE WITH AN ADVISORY FOR THESE LOCATIONS ALTHOUGH DO NOT EXPECT AS MUCH OF THE HIGHER- THAN-EXPECTED COVERAGE OF 110+ HEAT INDEX READINGS THAT MATERIALIZED YESTERDAY IN EASTERN ZONES. OUTSIDE THE ADVISORY AREA TO THE NORTH AND WEST...IT WILL OBVIOUSLY STILL BE HOT...BUT LOOKING FOR SUB-ADVISORY LEVEL HEAT INDEX VALUES MORE INTO THE 95-102 RANGE. FOR THIS EVENING/TONIGHT...OBVIOUSLY HEAT INDEX/ADVISORY ISSUES WILL QUICKLY ABATE...LEAVING THE ULTIMATE QUESTION AS TO HOW MUCH IF ANY CONVECTION AND POSSIBLE STRONG-SEVERE STORM POTENTIAL REMAINS THROUGH THE NIGHT. AS FOR THE BIG PICTURE OF THE MID-UPPER LEVELS...FLOW WILL TURN EVEN MORE NORTHERLY AS THE STRONG HIGH PRESSURE CENTER PARKS ITSELF FIRMLY OVER CENTRAL CO...WHICH ACTUALLY ALLOWS MID LEVEL TEMPS TO COOL VERY SLIGHTLY OVER THE LOCAL AREA AS A LOW-AMPLITUDE SHORTWAVE TROUGH BRUSHES BY ALONG A TRACK FROM THE DAKOTAS INTO IA OVERNIGHT. AT THE SURFACE...GENERALLY EAST- NORTHEAST BREEZES AROUND 10 MPH WILL PREVAIL OVERNIGHT AS HIGH PRESSURE REMAINS CENTERED WELL OFF TO THE NORTHEAST OF THE LOCAL AREA. AS MENTIONED ABOVE...THERE IS TREMENDOUS UNCERTAINTY IN THE CONVECTIVE POTENTIAL OVERNIGHT. ONE SCENARIO IS THAT ONCE ANY EVENING ACTIVITY DIES OUT OR MOVES OUT OF THE AREA IN THE SOUTHERN CWA ALONG THE FRONTAL ZONE THAT NOTHING ELSE OCCURS THE REST OF THE NIGHT (PER THE ECMWF AND ALSO THE NSSL 4KM-WRF). MEANWHILE...OTHER MODELS SUCH AS THE NAM/GFS AND ALSO THE 4KM WRF-NMM SIMULATED REFLECTIVITY SHOW POTENTIALLY A FAIR AMOUNT OF CONVECTION AFFECTING MAINLY THE SOUTHWEST HALF OF THE CWA AFTER MIDNIGHT...POSSIBLY AS A RESULT OF A STORM COMPLEX RIDING SOUTHEASTWARD INTO THE AREA OUT OF THE BLACK HILLS/NORTHWEST NEB AREA. GIVEN THE TREMENDOUS UNCERTAINTY HERE...OPTED NOT TO GET CUTE WITH THE FORECAST AND JUST BLANKETED MUCH OF THE CENTRAL/SOUTHERN CWA WITH A GENERIC SLIGHT 20 PERCENT POP FOR THE LATER NIGHT HOURS. BESIDES CONVECTIVE POTENTIAL...SUPPOSE AT LEAST SOME LIGHT FOG CANNOT BE RULED OUT LATE TONIGHT MAINLY IN WESTERN ZONES...BUT CURRENT MODELS/GUIDANCE DO NOT SUPPORT VISIBILITY RESTRICTIONS BAD ENOUGH/WIDESPREAD ENOUGH FOR A FORMAL FORECAST INCLUSION AT THIS TIME. AS FOR LOW TEMPS...ONLY MADE MINOR TWEAKS AIMING FOR A RANGE FROM MID 60S NORTH TO AROUND 70 SOUTH. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 501 AM CDT TUE JUL 22 2014 TEMPS WILL BE UP AND DOWN DURING THE EXTENDED PERIODS AND ALTHOUGH THERE ARE HIT OR MISS CHCS FOR TSTMS...NOTHING IS LOOKING WIDESPREAD OR SIGNIFICANT AT THIS POINT IN TIME. FOLLOWING THE REALLY HOT TEMPERATURES MONDAY AND TUESDAY...READINGS WILL TREND COOLER ON WEDNESDAY AS THE UPPER RIDGE AXIS RETROGRADES ALONG THE HIGH PLAINS AND A TROUGH DEEPENS FM THE GREAT LAKES THRU THE OHIO VALLEY REGION. THE HOT AIR RETREATS AND COOLER AIR BACKS IN FROM THE EAST AND H85 TEMPS COOL SEVERAL DEGREES AND WE ARE LOOKING FOR AFTERNOON HIGHS TO RANGE FROM THE MID 80S IN OUR EASTERN ZONES TO AROUND 90F IN THE SW. A 1020MB SFC HIGH PRESSURE SYSTEM BUILDS SOUTH FROM THE UPPER MIDWEST WHICH WILL RESULT IN EASTERLY LLVL FLOW AND BRING THE COOLEST CONDITIONS TO OUR EASTERN ZONES. HAVE KEPT THE FORECAST DRY BUT THERE IS AN OUTSIDE CHC FOR REMNANT CONVECTION TO LINGER FOR A TIME WEDNESDAY MORNING IN THE VCNTY OF THE FRONTAL BOUNDARY IN OUR SOUTH. TEMPERATURES WILL BE ON THE INCREASE AGAIN THURSDAY FRIDAY AS THE UPPER RIDGE AXIS BUILDS EAST AGAIN AHEAD OF AN UPPER LOW TRANSLATING EAST FROM THE PACIFIC NORTHWEST. THE RIDGE AXIS DEAMPLIFIES BY THE END OF THE WEEK BUT THE AIRMASS REMAINS QUITE WARM THRU FRIDAY AND HIGH TEMPERATURES SHOULD AGAIN AVERAGE IN THE 90S. A PROGRESSING MID LEVEL SHORTWAVE TROUGH AND WAA AHEAD OF THE SYSTEM WILL BRING THE POTENTIAL FOR TSTMS THURSDAY AND THURSDAY NIGHT. THEN...A COLD FRONT ASSOCIATED WITH THE NORTHERN CONUS SYSTEM PUSHES SOUTHEAST DURING THE DAY ON FRIDAY BUT CHCS FOR STORMS LOOK NEGLIGIBLE WITH THE BOUNDARY. OVER THE WEEKEND AND EARLY NEXT WEEK THE UPPER RIDGE RETROGRADES AND BUILDS OVER THE ROCKIES WHILE AN UPPER TROUGH DEEPENS FM THE GREAT LAKES THROUGH THE OHIO VALLEY. COOLER AIR WILL RETURN IN THE MORE MERIDIONAL FLOW AND TEMPERATURES WILL DROP BACK CLOSER TO SEASONAL READINGS OR BELOW. CANNOT COMPLETELY RULE OUT PCPN CHCS IN THE OUTER PERIODS AS TEMPERATURES COOL ALOFT AND BOUNDARIES MOVE THRU. THIS BEING SAID NOTHING SAID THERE IS NO REAL CONCLUSIVE PERIOD FOR CONVECTION EITHER AND HAVE ONLY CARRIED LOW POPS IN OUR SOUTH FOR SUNDAY NIGHT. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUESDAY) ISSUED AT 1252 AM CDT TUE JUL 22 2014 CONFIDENCE IS FAIRLY HIGH IN VFR CEILING/VISIBILITY PERSISTING THROUGH THE PERIOD UNDER VARIABLE COVERAGE OF HIGH CLOUDS...AND WITH THE CHANCE OF ANY SHOWERS/THUNDERSTORMS IN THE AREA LIKELY AVERAGING ONLY AROUND 10 PERCENT (MAINLY FOR THE TUESDAY EVENING HOURS)...CANNOT EVEN JUSTIFY A VICINITY THUNDERSTORM (VCTS) MENTION AT THIS TIME. ALTHOUGH THERE COULD BE SOME MARGINAL LOW LEVEL WIND SHEAR RIGHT AWAY DURING THE FIRST FEW HOURS THIS MORNING...THE OVERALL BULK SHEAR DIFFERENCE WITHIN THE LOWEST 2000 FT APPEARS TO ONLY TOP OUT AROUND 25-30KT AT BEST...AND SLOWLY DECREASING WITH TIME. AS A RESULT...HAVE REFRAINED FROM ANY FORMAL LLWS MENTION IN THE TAFS. SUSTAINED SURFACE BREEZES ARE EXPECTED TO AVERAGE AT/UNDER 12KT THROUGH THE MAJORITY OF THE PERIOD...WITH THE MAIN FEATURE BEING A WIND SHIFT ASSOCIATED WITH A WEAK COLD FRONT THAT WILL SWITCH DIRECTION FROM SOUTH-SOUTHWESTERLY EARLY THIS MORNING TO PREVAILING NORTHEASTERLY FROM MID-LATE MORNING ONWARD. && .GID WATCHES/WARNINGS/ADVISORIES... NE...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR NEZ064-074>077-083>087. KS...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR KSZ005>007-017>019. && $$ SHORT TERM...PFANNKUCH LONG TERM...FAY AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
930 AM CDT TUE JUL 22 2014 .UPDATE... FORECAST LOOKS TO BE ON TRACK AND NO CHANGES WERE MADE. TEMPERATURES ALREADY WARMING THROUGH THE 80S PER LATEST OBS WITH DEWPOINTS IN THE UPPER 60S AND 70S...AND A HOT AND HUMID DAY IS ON TAP WITH AFTERNOON HEAT INDICES TOPPING OUT WELL INTO THE 90S UP TO NEAR 100 DEGREES. POPS MAY BE A TAD ON THE HIGH SIDE OVER SOUTH AND EAST ZONES BASED ON LATEST HRRR RUNS BUT WILL LEAVE AS IS FOR NOW. SHAMBURGER && .PREV DISCUSSION... /ISSUED 606 AM CDT TUE JUL 22 2014/ AVIATION UPDATE...FOR 12Z TAF PACKAGE... SIMILAR TO YESTERDAY...BEST CHANCE FOR TSRA IMPACTS WILL BE AT KCSV. INCLUDED VCTS AGAIN AS LOCATION OF STORM DEVELOPMENT IS UNCLEAR. CLOUD COVER SHOULD PERSIST OVER THE EASTERN HALF OF THE MID STATE BUT SHOULD STAY AT VFR THROUGHOUT THE PERIOD. ONLY OBSTRUCTIONS WOULD BE LIGHT TO MODERATE FOG TOWARD THE MORNING HOURS TOMORROW. PREV DISCUSSION... /ISSUED 328 AM CDT TUE JUL 22 2014/ DISCUSSION... UPPER LOW CONTINUING TO SPIN ACROSS THE DEEP SOUTH NEAR THE FL PANHANDLE THIS MORNING. PERSISTENT UPPER DIVERGENCE HAS HELPED TO PROLONG THE NOCTURNAL SHOWER ACTIVITY TO THE EAST OF THE LOW. ACROSS MIDDLE TN...BROKEN CLOUDINESS STILL PERSISTS ACROSS OUR SOUTHEASTERN COUNTIES WITH PCLDY SKIES ELSEWHERE. OVER THE NEXT FEW DAYS...UPPER TROUGHING TO EXPAND ACROSS THE GREAT LAKES REGION WITH UPPER LEVEL HIGH EXPANSION ACROSS THE SOUTHWESTERN U.S.. THE PATTERN OVER THE MID STATE WILL THEN MORPH INTO MORE OF A ROBUST NORTHWESTERLY FLOW ALOFT. IN FACT...A COLD FRONT WILL SLIDE ACROSS THE AREA WEDNESDAY NIGHT AND BRING A CHANCE OF SHOWERS AND TSTMS. THE BOUNDARY LOOKS AS THOUGH IT WILL MAKE IT JUST SOUTH OF TN BY THURSDAY. SO FOR THE FCST...LOW CONVECTION CHANCES FOR TODAY AS THE WEAKENING UPPER LOW CONTINUES TO EXERT SOME INFLUENCE ACROSS THE AREA. POPS WILL INCREASE WED AFTERNOON AND NIGHT. FOR THE NEAR TERM TEMPS...QUITE WARM TODAY AND AGAIN ON WEDNESDAY AS HEIGHTS INCREASE...COMPLIMENTS OF THE STRENGTHENING UPPER RIDGE TO OUR WEST. WE`LL COOL THINGS OFF BY THURSDAY BEHIND THE AFOREMENTIONED FRONTAL PASSAGE. IN THE EXT FCST...NORTHWESTERLY FLOW TO CONTINUE THROUGH THE EXTENDED PERIOD. ANOTHER FRONTAL BOUNDARY WILL IMPACT THE AREA ON SUNDAY WITH WHAT LOOKS LIKE A DESCENT SHOT OF RAIN. FRONTAL BOUNDARY WILL PUSH SOUTH OF THE MID STATE ON MONDAY WITH A DEEPENING UPPER TROUGH INDICATED ACROSS THE EASTERN U.S.. FOR THE EXT TEMPS...WARM AGAIN THIS WEEKEND IN ADVANCE OF THE NEXT COLD FRONT. SLIGHTLY BELOW NORMAL TEMPS WILL RETURN BY EARLY NEXT WEEK. DEWPOINTS ARE LOOKING VERY PLEASANT FOR LATE JULY. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 55
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 AM CDT TUE JUL 22 2014 .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 253 AM CDT TUE JUL 22 2014 ORGANIZED LINE OF CONVECTION WORKING EAST ACROSS MINNESOTA AND NORTHERN WISCONSIN THIS MORNING. LOCAL AND REGIONAL RADARS SHOWING SOME ECHOES DEVELOPING SOUTH OF THE LINE ON THE EDGE OF THE MOISTURE TRANSPORT AXIS. LOOKING AT THE MESO SCALE MODELS THIS MORNING...THE HRRR AND RAP ARE PRETTY MUCH USELESS AS THEY TURN THE SYSTEM MORE NORTHEAST AND DISSIPATE IT WAY TOO QUICKLY. THE 22.00Z HI-RES ARW AND NMM LOOK MUCH MORE REASONABLE WITH THE CONVECTIVE COMPLEX AND CONTINUE MOVING IT EAST TAKING IT JUST NORTH OF THE FORECAST AREA. LOOKING AT THE 22.00Z NAM BUFKIT SOUNDING FOR LADYSMITH...THIS MAKES SENSE AS THE CAP HOLDS IN PLACE THROUGH THE REMAINDER OF THE NIGHT. AS FOR THE DEVELOPING ECHOES OVER THE FORECAST AREA...THESE ARE JUST STARTING TO GET SOME SPRINKLES TO THE GROUND. THE HI-RES NMM SHOWS THE ECHOES CONTINUING THROUGH THE NIGHT UNTIL THE MOISTURE TRANSPORT STARTS TO BEND MORE OFF TO THE EAST BUT DOES NOT REALLY SHOW THEM EXPANDING AND KEEPS THEM SCATTERED. WITH THE MAIN CONVECTIVE COMPLEX EXPECTED TO MOVE BY TO THE NORTH...HAVE LOWERED THE RAIN CHANCES ACROSS THE NORTH DOWN TO ABOUT 40 PERCENT FOR THIS MORNING. TO HANDLE THE LIGHT ECHOES...WILL SHOW ABOUT A 20 PERCENT AS FAR SOUTH AS I90 UNLESS OBSERVATIONS START INDICATING THAT THIS ACTIVITY IS REACHING THE GROUND. FOR THE REMAINDER OF TODAY...THE MAIN SHORT WAVE TROUGH WILL PASS ACROSS LAKE SUPERIOR INTO ONTARIO. A SECONDARY SHORT WAVE TROUGH WILL DROP ACROSS THE REGION DURING THE AFTERNOON AS THE FLOW BECOMES NORTHWEST ALOFT. IT APPEARS THAT THIS SECONDARY SHORT WAVE TROUGH WILL ONLY PRODUCE SOME WEAK PV ADVECTION IN THE 500-300 MB LAYER AS IT MOVES ACROSS. HOWEVER...THE FORCING FROM THIS WAVE DOES NOT LOOK LIKE IT WILL BE ABLE TO INTERACT WITH THE FRONT UNTIL IT HAS MOVED PAST THE AREA. THE NAM BUFKIT SOUNDING FOR BLUE RIVER INDICATES THE CAP WILL HOLD IN PLACE UNTIL LATE THIS AFTERNOON WHILE THE 22.00Z GFS HOLDS IT INTO THE EVENING. WITH THE CAP REMAINING IN PLACE...ALL THE MODELS SUGGEST FURTHER DEVELOPMENT ALONG THE FRONT DOES NOT TAKE PLACE UNTIL THIS EVENING AND SOUTH OF THE FORECAST AREA. JUST IN CASE THE NAM IS CORRECT AND THE CAP DISSIPATES A LITTLE SOONER...HAVE OPTED TO HOLD ONTO A 20 TO 30 PERCENT RAIN CHANCE ACROSS THE SOUTHEAST SECTIONS FOR THE LATE AFTERNOON INTO THE EARLY EVENING. LOOKS LIKE TEMPERATURES WILL HAVE A GOOD OPPORTUNITY TO WARM THIS AFTERNOON AHEAD OF THE FRONT. HIGH TEMPERATURES IN THE UPPER 80S TO LOWER 90S OVER THE SOUTHEAST HALF OF THE AREA ARE A PRETTY GOOD BET. DEW POINTS ARE EXPECTED TO AGAIN GET INTO THE MIDDLE 70S AHEAD OF THE FRONT...WHICH WILL PUSH THE HEAT INDEX IN THE ADVISORY RANGE ACROSS THE SOUTHERN SECTIONS AND WILL BE ISSUING A HEAT ADVISORY TO HANDLE THIS. THE REST OF THE PERIOD LOOKS TO BE QUIET WITH COOLER AND DRIER CONDITIONS AS A LARGE AREA OF HIGH PRESSURE MOVES ACROSS THE REGION FROM CANADA TOWARD THE OHIO RIVER VALLEY. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 253 AM CDT TUE JUL 22 2014 SOME DIFFERENCES BETWEEN THE MODELS ON HOW FAST THE NEXT SYSTEM MOVES INTO THE REGION. THE UPPER LEVEL RIDGE THAT BUILDS OVER THE WESTERN PART OF THE COUNTRY OVER THE FIRST HALF OF THE WEEK...GETS FLATTENED AS AN UPPER LEVEL LOW MOVES ONSHORE FROM THE PACIFIC AND ACROSS SOUTHERN CANADA. THE DIFFERENCES IN THE MODELS COMES FROM HOW FAST SHORT WAVE TROUGHS WILL CUT THROUGH THE FLOW BETWEEN THE UPPER LEVEL LOW AND THE RIDGE. IT LOOKS LIKE THE 22.00Z ECMWF CONTINUES TO BE FASTER THAN THE GFS AND 22.00Z GEM ON BRINGING THE FIRST SHORT WAVE THROUGH. HOWEVER...ALL OF THEM SHOW THE SAME GENERAL PATTERN WITH THE WAVE AND A SURFACE LOW TRACKING FROM THE DAKOTAS SOUTHEAST TOWARD THE OHIO RIVER VALLEY. WITH THE GFS AND GEM BEING A LITTLE SLOWER...WILL INDICATE THE HIGHEST RAIN CHANCES FRIDAY INTO FRIDAY NIGHT. THE NEXT SHORT WAVE TROUGH AND SURFACE LOW STILL LOOK TO COME THROUGH OVER THE WEEKEND AND TRACK FARTHER NORTHEAST THAN THE FRIDAY SYSTEM. THIS SYSTEM WILL BRING SOME RAIN CHANCES TO THE ENTIRE AREA FOR SUNDAY WITH THE BETTER CHANCES OVER CENTRAL WISCONSIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 600 AM CDT TUE JUL 22 2014 IMMEDIATE CONCERNS FOR EARLY THIS MORNING IS THE POTENTIAL FOR A FEW HOUR PERIOD OF MVFR CIGS/VSBYS. SATELLITE IMAGERY AND SFC OBS INDICATING A DROP IN VSBYS IN A CLEAR SLOT AHEAD OF AN APPROACHING COLD FRONT. SOME STRATUS ALSO STARTING TO DEVELOP-EXTEND INTO THIS REGION. BOTH COULD IMPACT KRST/KLSE...WITH A HIGHER LIKELIHOOD AT KRST. BUFKIT SOUNDINGS WOULD SUGGEST THAT ANY CIG THAT DID MOVE IN WOULD QUICKLY MIX OUT BETWEEN 14-16Z. WILL ADD CIG MENTION INTO A TEMPO GROUP FOR KRST FOR NOW...AND LEAVE OUT AT KLSE WERE CONFIDENCE IS A BIT LESS. SOME FUZZ WILL LINGER AT KRST UNTIL MID MORNING. VFR CONDITIONS SHOULD THEN BE THE RULE INTO TONIGHT. FOR WED MORNING...SOME SUGGESTIONS IN THE NAM KLSE SOUNDING OF VALLEY FOG POTENTIAL. DECOUPLING WILL RESULT IN A LIGHT WIND THIS EVENING...BUT DIRECTION COULD BE NORTHWEST. IF SO...LOCALE RESEARCH SUGGESTS DENSE FOG IS NOT LIKELY. ALSO...WINDS JUST OFF THE GROUND ARE EXPECTED TO BE 10+ KTS. ALSO NOT FAVORABLE. SO...WILL LEAVE ANY MENTION OUT OF THE FORECAST FOR NOW...BUT POTENTIAL SHOULD BE MONITORED. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR WIZ054-055-061. MN...NONE. IA...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR IAZ029-030. && $$ SHORT TERM...04 LONG TERM....04 AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
200 PM PDT Tue Jul 22 2014 .Synopsis... An upper wave moves over NorCal today with showers and potential thunderstorms. Then expect a warming trend Wednesday into the weekend. && .Short Term Discussion (Today through Thursday)... An upper level disturbance continues to lift northeastward through Northern California this afternoon. This system is interacting with the remaning monsoonal moisture aloft and has spread sprinkles to light rain across portions of the Northern San Joaquin and Sacramento valley so far today. A few stray lightning strikes were detected near Auburn and Chico as well. Short term guidance initially underestimated the instability/precipitation generated from this event however the HRRR caught up to observations by 18Z. Radar imagery has consistently shown southwest to northeast oriented band of precipitation of light precipitation stretching across Northern California this morning. This line is forming along an air mass boundary formed by the aforementioned upper level disturbance and should continue to push north-northeastward this afternoon into evening. A secondary line developed just south of the main band of precipitation. Precipitation so far has been fairly light in this band, with most stations recording a trace to around a tenth of an inch. The upper disturbance moves out of the area overnight. Winds become breezy through the Delta and over the mounatins tonight into Wednesday as the pattern shifts. The atmosphere dries out by midweek and leaves behind a more stable atmosphere under southwest flow aloft. Temperatures warm to above average for Thursday and Friday after skies clear and high pressure backbuilds from the desert southwest. Triple digit temperatures are possible in the latter half of the week. .Extended Discussion (Saturday through Tuesday) High pressure ridge building in from the Desert Southwest will result in above normal temperatures through the weekend and into early next week. Portions of the Central Valley will likely be reaching 100+ temperatures during this timeframe. There may be enough onshore flow through the Delta to keep Delta Breeze- influenced areas just below the triple-digit threshold. Medium-range models continue to suggest monsoonal moisture advecting northward. At this stage, a slight chance of thunderstorms will be possible south of Tahoe on Sunday, with perhaps a more widespread chance over the Sierra on Monday. Dang && .Aviation... Mainly VFR conditions expected the next 24 hours, with scattered mid to high clouds over the area. Isolated SHRA with a slight chance of TS will be possible generally north of KCIC through about 04z. Across the Valley, south to west winds 5 to 15 kt will continue through Wednesday. Near the Delta, southwest winds 15 to 30 kt will be possible through Wed. Dang && .STO Watches/Warnings/Advisories... None. && $$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
339 PM MDT TUE JUL 22 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 338 PM MDT TUE JUL 22 2014 TOWERING CUMULUS HAS BEEN CONFINED TO THE FRONT RANGE MOUNTAINS AND FOOTHILLS...AND PARK COUNTY SO FAR...WITH ANY PRECIPITATION JUST SOUTH OF THE FORECAST AREA TOWARD THE PIKES PEAK REGION. STILL EXPECT ISOLATED SHOWERS/STORMS TO DEVELOP IN THE FRONT RANGE MOUNTAINS AND FOOTHILLS LATE THIS AFTERNOON. IN THE LOWER ELEVATIONS...THE CAP IS WEAKENING AS WE HAVE HAD FULL SUNSHINE THROUGH THE DAY. LATEST ACARS SOUNDINGS SHOW IF WE REACH 95 NEAR DENVER WE COULD BREAK THE CAP. AT THIS TIME...IT WOULD STILL BE MORE LIKELY FOR THIS TO OCCUR ALONG THE ELEVATED TERRAIN OF THE PALMER DIVIDE OR CHEYENNE RIDGE. THE LATEST HRRR AND RAP13 HINT AT THIS...SO WILL CONTINUE THE LOW POPS IN/NEAR THOSE AREAS. ONLY CHANGE TO WEATHER WAS TO ADD SOME LOW POPS OVER THE NORTHEAST PLAINS LATE THIS EVENING AND OVERNIGHT AS LOW LEVEL JET AND MOISTURE CONVERGENCE INCREASE. HOWEVER...THIS OCCURS UNDER A LARGE DOMINATING RIDGE SO ONLY A SLIGHT CHANCE OF BREAKING THROUGH THE CAP AT THIS POINT. AREAS OF STRATUS MAY DEVELOP OVER THE EASTERN PLAINS AS WELL WITH CONTINUED ADVECTION OF LOW LEVEL MOISTURE IN UPSLOPE EAST/SOUTHEAST FLOW. ON WEDNESDAY...LOW LEVEL FLOW TURNS FROM SOUTHEAST TO MORE SOUTHERLY AS LEE TROUGH STRENGTHENS. LOOKS LIKE DENVER CONVERGENCE ZONE WILL GET ERODED AS LEE TROUGH DEVELOPS AND STRONGER MIXING OCCURS. AS A RESULT...BEST MOISTURE WILL LIKELY SHIFT NORTHWARD TO NEAR THE WYOMING BORDER AREA BY AFTERNOON. CAPES THERE MAY REACH 1000-1500 J/KG WITH A STRONGER STORM POSSIBLE. ELSEWHERE...LOOKS LIKE CONVECTION WILL BE HIGHER BASED WITH STRONG GUSTY OUTFLOW WINDS AND BRIEF MODERATE RAIN. STORM COVERAGE WILL BE HIGHEST IN MOUNTAINS WHERE A MID LEVEL MOISTURE PLUME IS EXPECTED TO ARRIVE BY MID/LATE AFTERNOON. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 338 PM MDT TUE JUL 22 2014 SOME THUNDERSTORMS WILL CONTINUE WEDNESDAY EVENING...MAINLY ACROSS THE MOUNTAINS. MAIN THREAT TO BE GUSTY OUTFLOW WINDS AS LOW LEVEL MOISTURE WILL BE LIMITED. STORMS SHOULD END AROUND MIDNIGHT AS AIRMASS STABILIZES. ON THURSDAY...UPPER RIDGE WILL BE OVER THE AREA WITH THE CENTER OF HIGH OVER CENTRAL NEW MEXICO. RIDGE GETS FLATTENED A BIT AS MID LEVEL SHORTWAVE MOVES ACROSS NORTHERN COLORADO WITH FLOW ALOFT BECOMING A BIT MORE WESTERLY. THERE IS SOME INCREASE IN MONSOON TYPE MOISTURE INTO COLORADO...MAINLY ACROSS THE MOUNTAINS. THIS WILL PROVIDE FOR A CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS...WITH THE BEST CHANCE OVER THE MOUNTAINS. STORMS TO PRODUCE GUSTY WINDS WITH BRIEF MODERATE RAIN. FOR FRIDAY...UPPER RIDGE REMAINS OVER THE AREA WITH WESTERLY FLOW ALOFT. MODELS INDICATE ANOTHER INFLUX OF MONSOONAL MOISTURE FLOW INTO THE AREA...MAINLY ACROSS THE MOUNTAINS. DAYTIME HEATING TO GENERATE SOME THUNDERSTORMS DURING THE AFTERNOON AND EVENING. A WEAK SURFACE FRONT LOOKS TO MOVE ACROSS THE NORTHEAST PLAINS WITH SOME SLIGHT LOW LEVEL COOLING. THIS MAY LIMIT THE THUNDERSTORM CHANCES ACROSS THE PLAINS AND WILL KEEP THE BEST CHANCE FOR THUNDERSTORMS OVER THE MOUNTAINS. HIGHS TO BE A FEW DEGREES COOLER ACROSS NORTHEAST COLORADO...BUT SHOULD STILL BE IN THE LOWER AND MIDDLE 90S. ON SATURDAY...MODELS SHOW THE UPPER RIDGE RETROGRADING A BIT WITH THE FLOW ALOFT OVER COLORADO BECOMING WEST NORTHWEST. MODELS SHOW SOME DECREASE IN THE MONSOON MOISTURE WITH MOST OF THE MOISTURE BEING DISPLACED OVER SOUTHERN COLORADO. GFS STILL DRIER THAT THE ECMWF...ESPECIALLY AT LOW LEVELS. WILL CONTINUE WITH A SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS. THERE APPEARS TO BE A MID LEVEL SHORTWAVE WHICH MOVES ACROSS ACROSS NORTHEAST COLORADO DURING THE AFTERNOON...PUSHING ANOTHER WEAK FRONT INTO THE AREA. LIFT WITH THIS WAVE MAY HELP INCREASE THE THUNDERSTORM CHANCES. FOR NOW WILL KEEP THE BEST CHANCE OVER THE HIGH COUNTRY. HIGHS TO BE IN THE LOW AND MID 90S ACROSS THE PLAINS. FOR THE LATER DAYS...SUNDAY THROUGH TUESDAY. FLOW ALOFT TO BECOME NORTHWEST SUNDAY. BOTH ECMWF AND GFS SHOW A SURFACE HIGH MOVING INTO NORTHEAST PLAINS WITH LOW LEVEL FLOW BECOME SOUTHEAST. THIS WILL HELP BRING SOME LOW LEVEL MOISTURE INTO THE AREA. FOR NOW WILL KEEP THE BEST CHANCE OF THUNDERSTORMS OVER THE MOUNTAINS. COOLER AIRMASS WITH HIGHS IN THE MID 80S ACROSS THE PLAINS. NORTHWEST FLOW ALOFT CONTINUES MONDAY AND TUESDAY WITH HIGHS SLIGHTLY BELOW AVERAGE ACROSS NORTHEAST COLORADO. ENOUGH MOISTURE FOR A SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS EACH DAY...MAINLY OVER THE MOUNTAINS. && .AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON) ISSUED AT 338 PM MDT TUE JUL 22 2014 VFR CONDITIONS ARE EXPECTED TO PERSIST. ONLY A SLIGHT 10 PERCENT CHANCE OF A STORM PASSING MAINLY TO THE SOUTH OF THE FRONT RANGE AIRPORTS WHICH COULD PRODUCE BRIEF GUSTY OUTFLOW WINDS TO 25-30 KTS. OTHERWISE EAST/SOUTHEAST WINDS WILL TURN MORE SOUTHERLY BY 05Z-08Z...AND THEN LIGHT/VARIABLE BY 10Z-14Z AS WEAK DENVER CYCLONE DEVELOPS. SOME STRATUS BELOW 1000 FT AGL POSSIBLE BUT AT THIS TIME THREAT WOULD BE WELL EAST AND NORTH OF KDEN AND KBJC. ON WEDNESDAY...SOUTHERLY WINDS WILL DEVELOP AND INCREASE TO 12G20KTS BY 18Z-21Z. ONLY A SLIGHT 20 PERCENT CHANCE OF STORMS AFTER 21Z. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARJENBRUCH LONG TERM...D-L AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS NEW YORK NY
428 PM EDT TUE JUL 22 2014 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO MOVE OFFSHORE AS A COLD FRONT APPROACHES FROM THE WEST. THE FRONT WILL MOVE ACROSS FROM WEDNESDAY NIGHT INTO THURSDAY...FOLLOWED BY BUILDING HIGH PRESSURE ON FRIDAY. THE HIGH WILL WEAKEN ON SATURDAY...THEN LOW PRESSURE PASSING TO THE SOUTHEAST WILL IMPACT THE AREA SUNDAY INTO MONDAY. AN ASSOCIATED COLD FRONT WILL APPROACH LATE DAY MONDAY...AND MOVE ACROSS MONDAY NIGHT INTO TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... SOME WEAK UPPER LEVEL ENERGY WILL SPILL OVER THE TOP OF THE RIDGE ALONG THE NORTHEAST THIS EVENING. SOME WIDELY ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS MAY DEVELOP EARLY IN THE EVENING HOURS... MAINLY NORTH AND WEST OF NYC. WILL CAP POPS AT 20 PERCENT...AS NOT EXPECTING MANY...IF ANY...STORMS. LATEST HRRR GUIDANCE CONTINUES TO INDICATE SOME SHOWERS...MAINLY WEST OF THE HUDSON RIVER AND INTO INTERIOR PORTIONS OF SW CT. ANY SHOWERS THAT DEVELOP WILL END BETWEEN 9-10 PM. WARM AND HUMID NIGHT ON TAP WITH LOWS IN THE 60S TO LOW 70S. THE WARMEST TEMPS WILL OCCUR IN/AROUND NYC DUE TO THE URBAN HEAT ISLAND EFFECT. SFC DEW POINTS WILL CLIMB THROUGH THE MID 60S AND INTO THE UPPER 60S. CAN EXPECT PATCHY FOG TO DEVELOP AWAY FROM THE CITY. THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING WITH ENHANCED SEA BREEZE DEVELOPMENT AND LONG PERIOD SE SWELLS. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... HOT AND INCREASINGLY HUMID AIR MASS REMAINS OVER THE AREA WEDNESDAY. WITH HIGH PRES DEPARTING AND COLD FRONT APPROACHING FROM THE WEST...SW FLOW INCREASES THROUGHOUT THE DAY...AND SFC DEWPOINTS WILL RISE THROUGH THE 60S AND INTO THE LOWER 70S. MAX TEMPS ON WEDNESDAY WILL TOP OFF IN THE LOWER 90S ACROSS NYC AND NE NJ...AND WILL BE IN THE UPPER 80S TO NEAR 90 ELSEWHERE. TEMPS WILL BE SIGHTLY COOLER NEAR THE COASTS. THE HEAT INDEX ON WEDNESDAY WILL GENERALLY TOP OFF IN THE LOW TO MID 90S...EXPECT FOR NYC/NE NJ...WHERE THE HEAT INDEX WILL BE IN THE MID TO UPPER 90S. SINCE THE HEAT INDEX IN NYC WILL NOT REACH 95 FOR 2 CONSECUTIVE DAYS...AND SINCE THE HEAT INDEX WILL REMAIN BELOW 100 ACROSS THE CWA...WILL NOT ISSUE A HEAT ADVISORY. AS COLD FRONT APPROACHES...SHOWERS AND THUNDERSTORMS WILL DEVELOP NORTH AND WEST OF NYC IN THE AFTERNOON ALONG A PRE-FRONTAL TROUGH. SHOWERS AND THUNDERSTORMS SPREAD EAST WEDNESDAY EVENING AND WEDNESDAY NIGHT...AND THE BULK OF THE ACTIVITY SHOULD HOLD OFF UNTIL WEDNESDAY NIGHT AS THE COLD FRONT PASSES THROUGH THE REGION. WITH THE HEAT AND HUMIDITY...ML MUCAPE VALUES WILL RANGE FROM 1000-1500 J/KG DURING THE DAY...AND THEN WILL DROP TO AROUND 400 J/KG AT NIGHT WITH THE LOSS OF THE HEATING. 0-6 KM BULK SHEAR WILL BE WEAK DURING THE DAY...AND THEN WILL RISE TO 25-35 KT AFTER 00Z THURSDAY. CANNOT RULE OUT STRONG WINDS WITH ANY THUNDERSTORMS... BUT PRIMARY THREAT WILL BE HEAVY RAIN DUE TO PWATS AROUND 2". FLASH FLOODING OF LOW LYING AND POOR DRAINAGE AREAS IS POSSIBLE. WILL NOT ISSUE A HAZARDOUS WEATHER OUTLOOK AS THE THREAT WILL NOT BE WIDESPREAD. SHOWERS AND THUNDERSTORMS TAPER OFF FROM WEST TO EAST WEDNESDAY NIGHT AS THE COLD FRONT WORKS ITS WAY ACROSS THE REGION. && .LONG TERM /THURSDAY THROUGH TUESDAY/... THE SFC COLD FRONT SHOULD BE TO THE EAST THU MORNING...BUT WITH THE H8 FRONT STILL YET TO MOVE ACROSS...A MID LEVEL TROUGH STILL WELL TO THE WEST AND POTENTIAL FOR A WEAK SFC WAVE ALONG THE FRONT TO SLOW ITS PROGRESS EVEN FURTHER...WILL HAVE LIKELY POP TO START ACROSS SE CT AND ERN LONG ISLAND AND CHANCE ELSEWHERE...WITH CHANCES GRADUALLY RAMPING DOWN DURING THE AFTERNOON AND EARLY EVENING. CONDS LOOK MAINLY DRY FOR LATER THU NIGHT AND MORE SO INTO FRI AS HIGH PRESSURE BUILDS FROM THE WEST. THE HIGH SHOULD WEAKEN ON SAT AS FLOW ALOFT BECOMES MORE ZONAL. AS LOW TO MID LEVEL MOISTURE RETURN COMMENCES...WITH PRECIP EFFICIENCY INCREASING BACK TO OVER 1 INCH BY LATE DAY...AND AS MID LEVEL SHORTWAVES APPROACH IN ZONAL FLOW...SHOULD START TO SEE INCREASING CHANCES FOR SHOWERS/TSTMS BEGINNING LATE DAY SAT INTO SAT NIGHT. THE FLOW ALOFT SHOULD UNDERGO SIGNIFICANT AMPLIFICATION EARLY NEXT WEEK AS AN UPPER RIDGE BUILDS IN THE WESTERN STATES AND A POTENT SHORTWAVE TROUGH DIVING OUT OF CENTRAL CANADA MERGES WITH AN UPPER LOW OVER QUEBEC...CARVING OUT A DEEP LONGWAVE TROUGH OVER THE EASTERN STATES. THERE WILL BE GOOD CHANCES FOR SHOWERS/TSTMS... ESPECIALLY SUNDAY NIGHT INTO MON MORNING AS AN ASSOCIATED WAVE OF LOW PRESSURE PASSES JUST OFF TO THE SE...THEN LATE DAY MON INTO MON NIGHT WITH THE APPROACH OF A COLD FRONT FROM THE WEST. COULD SEE SOME LEFTOVER SHOWERS/TSTMS ON TUE MAINLY IN THE MORNING AS THE COLD FRONT MOVES TO THE EAST...THEN DRIER AND SLIGHTLY COOLER AIR ARRIVING THROUGH THE REST OF TUE INTO TUE NIGHT. && .AVIATION /21Z TUESDAY THROUGH SUNDAY/... HIGH PRESSURE CONTINUES TO SLOWLY MOVE OFFSHORE. VFR THROUGH MUCH OF THE TAF PERIOD. SEA BREEZE HAVE MOVED ACROSS MOST TERMINALS. KEWR IS THE EXCEPTION LATE THIS AFTERNOON. WINDS DIMINISH TONIGHT...WITH MOST SPOTS BECOMING LIGHT AND VARIABLE. SPEEDS INCREASE ONCE AGAIN ON WEDNESDAY. THERE IS A CHANCE OF PATCHY FOG TONIGHT. HAVE INCLUDED SOME TEMPOS FOR REDUCED VSBYS AFTER 08Z. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: STRONG SOUTH SEA BREEZE LIGHTENS AFTER SUNSET. KLGA FCSTER COMMENTS: GUSTS BECOME LESS FREQUENT AS WINDS LIGHTEN AFTER SUNSET. KEWR FCSTER COMMENTS: SEA BREEZE SHOULD REMAIN JUST TO THE EAST OF THE AIRPORT. LOW CONFIDENCE IN SEABREEZE MOVING THROUGH RESULTING IN A WIND SHIFT. KTEB FCSTER COMMENTS: SOUTH WINDS LIGHTEN AS THEY TURN TO THE SOUTHWEST. KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. PLEASE SEE TERMINAL FORECAST FOR DETAILS. KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. PLEASE SEE TERMINAL FORECAST FOR DETAILS. .OUTLOOK FOR 18Z WED THROUGH SUN... .WED AFTERNOON...PRIMARILY VFR. ISOLATED SHRA/TSTM LATE. .WED NIGHT-THU...SLOW MOVING COLD FROPA. MVFR OR LOWER CONDS IN SCT-NUMEROUS SHOWERS/TSTMS. .THU NIGHT-SAT...VFR. .SUN...CHANCE OF SHOWERS OR THUNDERSTORMS. SUB-VFR POSSIBLE. && .MARINE... THE LOCAL ENHANCED SEA BREEZE IS RESULTING IN 15-20 KT WINDS ACROSS NY HARBOR AND THE WESTERN OCEAN WATERS. NOT EXPECTING 25 KT GUSTS...SO WILL NOT HOIST A BRIEF SMALL CRAFT ADVISORY. OTHERWISE...SUB-SCA CONDS EXPECTED THROUGH TONIGHT. PATCHY FOG WILL DEVELOP ON THE WATERS TONIGHT...REDUCING VSBY TO AS LOW AS 1 NM. WINDS WILL INCREASE TO 15-20 KT ONCE AGAIN ON THE OCEAN WATERS WEDNESDAY AFTERNOON AND TO 10-15 KT WITH 15-20 KT GUSTS ON THE REST OF THE WATERS AHEAD OF AN APPROACHING COLD FRONT. CONVECTION LIKELY WEDNESDAY NIGHT. SEAS WILL AVERAGE 2-4 FT ON THE OCEAN AND AROUND 1 FT ELSEWHERE. OUTSIDE OF TSTMS THU AND LATE DAY SAT HAVE HIGH CONFIDENCE IN QUIET CONDS THU THROUGH SAT...THEN FCST UNCERTAINTY CREEPS IN BEGINNING ON SUNDAY. HAVE FCST CONTINUED QUIET CONDS...BUT IF AN APPROACHING WAVE OF LOW PRESSURE AND/OR FRONTAL SYSTEM ARE STRONGER THAN FCST...HAZARDOUS OCEAN SEAS COULD DEVELOP IF CORRESPONDING S-SW FLOW IS STRONGER THAN FCST. && .HYDROLOGY... THERE IS THE POTENTIAL FOR AROUND 1/2 INCH OF RAINFALL FROM LATE WEDNESDAY THROUGH THURSDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE. PRECIPITABLE WATERS ARE FORECAST TO BE AROUND 2 INCHES ON WEDNESDAY NIGHT...SO LOCALLY HEAVY RAINFALL IS POSSIBLE IN ANY STRONGER CONVECTION. AREAS EXPERIENCING LOCALLY HEAVY RAINFALL COULD EXPERIENCE AT LEAST MINOR FLOODING OF URBAN/POOR DRAINAGE AREA...AND POSSIBLY LOCALIZED FLASH FLOODING. THE CONFIDENCE IN THE LATTER IS CURRENTLY LESS THAN 30 PERCENT SO WILL NOT HIGHLIGHT IN THE HAZARDOUS WEATHER OUTLOOK. LOW PRESSURE PASSING JUST OFF TO THE SE SUNDAY NIGHT INTO MON MORNING...FOLLOWED BY A COLD FRONTAL PASSAGE LATER MON...HAVE SOME POTENTIAL TO PRODUCE HEAVY RAIN...AS PRECIP EFFICIENCY INCREASES TO OVER 1.5 INCHES. THIS WILL DEPEND FIRST ON THE LOW TRACK...THEN ON POTENTIAL FOR TRAINING OF CELLS AHEAD OF THE COLD FRONT...AS WELL AS OTHER MESOSCALE/THERMODYNAMIC FACTORS. GIVEN THESE UNCERTAINTIES IT IS TOO EARLY TO OUTLOOK THIS IN THE HWO. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...GOODMAN/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...GOODMAN AVIATION...BC/PW MARINE...GOODMAN/MPS HYDROLOGY...GOODMAN/MPS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
345 PM EDT TUE JUL 22 2014 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO MOVE OFFSHORE AS A COLD FRONT APPROACHES FROM THE WEST. THE FRONT WILL MOVE ACROSS FROM WEDNESDAY NIGHT INTO THURSDAY...FOLLOWED BY BUILDING HIGH PRESSURE ON FRIDAY. THE HIGH WILL WEAKEN ON SATURDAY...THEN LOW PRESSURE PASSING TO THE SOUTHEAST WILL IMPACT THE AREA SUNDAY INTO MONDAY. AN ASSOCIATED COLD FRONT WILL APPROACH LATE DAY MONDAY...AND MOVE ACROSS MONDAY NIGHT INTO TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... SOME WEAK UPPER LEVEL ENERGY WILL SPILL OVER THE TOP OF THE RIDGE ALONG THE NORTHEAST THIS EVENING. SOME WIDELY ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS MAY DEVELOP EARLY IN THE EVENING HOURS... MAINLY NORTH AND WEST OF NYC. WILL CAP POPS AT 20 PERCENT...AS NOT EXPECTING MANY...IF ANY...STORMS. LATEST HRRR GUIDANCE CONTINUES TO INDICATE SOME SHOWERS...MAINLY WEST OF THE HUDSON RIVER AND INTO INTERIOR PORTIONS OF SW CT. ANY SHOWERS THAT DEVELOP WILL END BETWEEN 9-10 PM. WARM AND HUMID NIGHT ON TAP WITH LOWS IN THE 60S TO LOW 70S. THE WARMEST TEMPS WILL OCCUR IN/AROUND NYC DUE TO THE URBAN HEAT ISLAND EFFECT. SFC DEW POINTS WILL CLIMB THROUGH THE MID 60S AND INTO THE UPPER 60S. CAN EXPECT PATCHY FOG TO DEVELOP AWAY FROM THE CITY. THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING WITH ENHANCED SEA BREEZE DEVELOPMENT AND LONG PERIOD SE SWELLS. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... HOT AND INCREASINGLY HUMID AIR MASS REMAINS OVER THE AREA WEDNESDAY. WITH HIGH PRES DEPARTING AND COLD FRONT APPROACHING FROM THE WEST...SW FLOW INCREASES THROUGHOUT THE DAY...AND SFC DEWPOINTS WILL RISE THROUGH THE 60S AND INTO THE LOWER 70S. MAX TEMPS ON WEDNESDAY WILL TOP OFF IN THE LOWER 90S ACROSS NYC AND NE NJ...AND WILL BE IN THE UPPER 80S TO NEAR 90 ELSEWHERE. TEMPS WILL BE SIGHTLY COOLER NEAR THE COASTS. THE HEAT INDEX ON WEDNESDAY WILL GENERALLY TOP OFF IN THE LOW TO MID 90S...EXPECT FOR NYC/NE NJ...WHERE THE HEAT INDEX WILL BE IN THE MID TO UPPER 90S. SINCE THE HEAT INDEX IN NYC WILL NOT REACH 95 FOR 2 CONSECUTIVE DAYS...AND SINCE THE HEAT INDEX WILL REMAIN BELOW 100 ACROSS THE CWA...WILL NOT ISSUE A HEAT ADVISORY. AS COLD FRONT APPROACHES...SHOWERS AND THUNDERSTORMS WILL DEVELOP NORTH AND WEST OF NYC IN THE AFTERNOON ALONG A PRE-FRONTAL TROUGH. SHOWERS AND THUNDERSTORMS SPREAD EAST WEDNESDAY EVENING AND WEDNESDAY NIGHT...AND THE BULK OF THE ACTIVITY SHOULD HOLD OFF UNTIL WEDNESDAY NIGHT AS THE COLD FRONT PASSES THROUGH THE REGION. WITH THE HEAT AND HUMIDITY...ML MUCAPE VALUES WILL RANGE FROM 1000-1500 J/KG DURING THE DAY...AND THEN WILL DROP TO AROUND 400 J/KG AT NIGHT WITH THE LOSS OF THE HEATING. 0-6 KM BULK SHEAR WILL BE WEAK DURING THE DAY...AND THEN WILL RISE TO 25-35 KT AFTER 00Z THURSDAY. CANNOT RULE OUT STRONG WINDS WITH ANY THUNDERSTORMS... BUT PRIMARY THREAT WILL BE HEAVY RAIN DUE TO PWATS AROUND 2". FLASH FLOODING OF LOW LYING AND POOR DRAINAGE AREAS IS POSSIBLE. WILL NOT ISSUE A HAZARDOUS WEATHER OUTLOOK AS THE THREAT WILL NOT BE WIDESPREAD. SHOWERS AND THUNDERSTORMS TAPER OFF FROM WEST TO EAST WEDNESDAY NIGHT AS THE COLD FRONT WORKS ITS WAY ACROSS THE REGION. && .LONG TERM /THURSDAY THROUGH TUESDAY/... THE SFC COLD FRONT SHOULD BE TO THE EAST THU MORNING...BUT WITH THE H8 FRONT STILL YET TO MOVE ACROSS...A MID LEVEL TROUGH STILL WELL TO THE WEST AND POTENTIAL FOR A WEAK SFC WAVE ALONG THE FRONT TO SLOW ITS PROGRESS EVEN FURTHER...WILL HAVE LIKELY POP TO START ACROSS SE CT AND ERN LONG ISLAND AND CHANCE ELSEWHERE...WITH CHANCES GRADUALLY RAMPING DOWN DURING THE AFTERNOON AND EARLY EVENING. CONDS LOOK MAINLY DRY FOR LATER THU NIGHT AND MORE SO INTO FRI AS HIGH PRESSURE BUILDS FROM THE WEST. THE HIGH SHOULD WEAKEN ON SAT AS FLOW ALOFT BECOMES MORE ZONAL. AS LOW TO MID LEVEL MOISTURE RETURN COMMENCES...WITH PRECIP EFFICIENCY INCREASING BACK TO OVER 1 INCH BY LATE DAY...AND AS MID LEVEL SHORTWAVES APPROACH IN ZONAL FLOW...SHOULD START TO SEE INCREASING CHANCES FOR SHOWERS/TSTMS BEGINNING LATE DAY SAT INTO SAT NIGHT. THE FLOW ALOFT SHOULD UNDERGO SIGNIFICANT AMPLIFICATION EARLY NEXT WEEK AS AN UPPER RIDGE BUILDS IN THE WESTERN STATES AND A POTENT SHORTWAVE TROUGH DIVING OUT OF CENTRAL CANADA MERGES WITH AN UPPER LOW OVER QUEBEC...CARVING OUT A DEEP LONGWAVE TROUGH OVER THE EASTERN STATES. THERE WILL BE GOOD CHANCES FOR SHOWERS/TSTMS... ESPECIALLY SUNDAY NIGHT INTO MON MORNING AS AN ASSOCIATED WAVE OF LOW PRESSURE PASSES JUST OFF TO THE SE...THEN LATE DAY MON INTO MON NIGHT WITH THE APPROACH OF A COLD FRONT FROM THE WEST. COULD SEE SOME LEFTOVER SHOWERS/TSTMS ON TUE MAINLY IN THE MORNING AS THE COLD FRONT MOVES TO THE EAST...THEN DRIER AND SLIGHTLY COOLER AIR ARRIVING THROUGH THE REST OF TUE INTO TUE NIGHT. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... HIGH PRESSURE CONTINUES TO SLOWLY MOVE OFFSHORE. VFR THROUGH MUCH OF THE TAF PERIOD. SEA BREEZE HAVE DEVELOPED THIS AFTERNOON AT KJFK/LGA. THE SEA BREEZE SHOULD REACH KEWR BY 21Z. THIS WILL RESULT IN WIND DIRECTION AROUND 170-180 TRUE BY LATE AFTERNOON. WINDS DIMINISH TONIGHT...WITH MOST SPOTS BECOMING LIGHT AND VARIABLE. SPEEDS INCREASE ONCE AGAIN ON WEDNESDAY. THERE IS A CHANCE OF SOME PATCHY FOG TONIGHT. HAVE INCLUDED SOME TEMPOS FOR REDUCE VSBYS AFTER 08Z. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR. KLGA FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS. GUSTS MAY BE OCCASIONAL THIS AFTERNOON. KEWR FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY CLOSER TO 220 TRUE. KTEB FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY CLOSER TO 220 TRUE. KHPN FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS. KISP FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR. GUSTS MAY BE OCCASIONAL. .OUTLOOK FOR 18Z WED THROUGH SUN... .WED AFTERNOON...PRIMARILY VFR. ISOLATED SHRA/TSTM LATE. .WED NIGHT-THU...SLOW MOVING COLD FROPA. MVFR OR LOWER CONDS IN SCT-NUMEROUS SHOWERS/TSTMS. .THU NIGHT-SAT...VFR. .SUN...CHANCE OF SHOWERS OR THUNDERSTORMS. SUB-VFR POSSIBLE. && .MARINE... THE LOCAL ENHANCED SEA BREEZE IS RESULTING IN 15-20 KT WINDS ACROSS NY HARBOR AND THE WESTERN OCEAN WATERS. NOT EXPECTING 25 KT GUSTS...SO WILL NOT HOIST A BRIEF SMALL CRAFT ADVISORY. OTHERWISE...SUB-SCA CONDS EXPECTED THROUGH TONIGHT. PATCHY FOG WILL DEVELOP ON THE WATERS TONIGHT...REDUCING VSBY TO AS LOW AS 1 NM. WINDS WILL INCREASE TO 15-20 KT ONCE AGAIN ON THE OCEAN WATERS WEDNESDAY AFTERNOON AND TO 10-15 KT WITH 15-20 KT GUSTS ON THE REST OF THE WATERS AHEAD OF AN APPROACHING COLD FRONT. CONVECTION LIKELY WEDNESDAY NIGHT. SEAS WILL AVERAGE 2-4 FT ON THE OCEAN AND AROUND 1 FT ELSEWHERE. OUTSIDE OF TSTMS THU AND LATE DAY SAT HAVE HIGH CONFIDENCE IN QUIET CONDS THU THROUGH SAT...THEN FCST UNCERTAINTY CREEPS IN BEGINNING ON SUNDAY. HAVE FCST CONTINUED QUIET CONDS...BUT IF AN APPROACHING WAVE OF LOW PRESSURE AND/OR FRONTAL SYSTEM ARE STRONGER THAN FCST...HAZARDOUS OCEAN SEAS COULD DEVELOP IF CORRESPONDING S-SW FLOW IS STRONGER THAN FCST. && .HYDROLOGY... THERE IS THE POTENTIAL FOR AROUND 1/2 INCH OF RAINFALL FROM LATE WEDNESDAY THROUGH THURSDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE. PRECIPITABLE WATERS ARE FORECAST TO BE AROUND 2 INCHES ON WEDNESDAY NIGHT...SO LOCALLY HEAVY RAINFALL IS POSSIBLE IN ANY STRONGER CONVECTION. AREAS EXPERIENCING LOCALLY HEAVY RAINFALL COULD EXPERIENCE AT LEAST MINOR FLOODING OF URBAN/POOR DRAINAGE AREA...AND POSSIBLY LOCALIZED FLASH FLOODING. THE CONFIDENCE IN THE LATTER IS CURRENTLY LESS THAN 30 PERCENT SO WILL NOT HIGHLIGHT IN THE HAZARDOUS WEATHER OUTLOOK. LOW PRESSURE PASSING JUST OFF TO THE SE SUNDAY NIGHT INTO MON MORNING...FOLLOWED BY A COLD FRONTAL PASSAGE LATER MON...HAVE SOME POTENTIAL TO PRODUCE HEAVY RAIN...AS PRECIP EFFICIENCY INCREASES TO OVER 1.5 INCHES. THIS WILL DEPEND FIRST ON THE LOW TRACK...THEN ON POTENTIAL FOR TRAINING OF CELLS AHEAD OF THE COLD FRONT...AS WELL AS OTHER MESOSCALE/THERMODYNAMIC FACTORS. GIVEN THESE UNCERTAINTIES IT IS TOO EARLY TO OUTLOOK THIS IN THE HWO. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...GOODMAN/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...GOODMAN AVIATION...BC MARINE...GOODMAN/MPS HYDROLOGY...GOODMAN/MPS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
135 PM EDT TUE JUL 22 2014 .SYNOPSIS... AS A HIGH PRESSURE SYSTEM MOVES SLOWLY EAST OF THE AREA TODAY...A COLD FRONT WILL APPROACH FROM THE WEST ON WEDNESDAY. THE COLD FRONT CROSSES THE AREA FROM WEDNESDAY NIGHT INTO THURSDAY MORNING...FOLLOWED BY HIGH PRESSURE BUILDING TO THE SOUTH OF LONG ISLAND INTO SATURDAY. A STORM SYSTEM THEN IMPACTS THE AREA INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WILL CUT AFTERNOON POPS DOWN FROM LOW CHANCE TO SLIGHT CHANCE AND CAP POPS AT 20 PERCENT. LATEST HRRR INDICATING ONLY SPOTTY SHOWERS...AND 12Z NAM DOES NOT HAVE MORE THAN ISOLATED COVERAGE AT BEST. SEA BREEZES CONTINUE TO WORK THEIR WAY NORTH THROUGH THE REGION. WIND SPEEDS WILL BE 10 KT OR LESS. TEMPS ACROSS LONG ISLAND AND COASTAL CT WILL EITHER HOLD STEADY OR ONLY SLOWLY WARM THROUGH THE REST OF THE AFTERNOON. OTHERWISE...SKIES WILL BE SUNNY WITH TEMPS A FEW DEGREES ABOVE NORMAL...TOPPING OFF IN THE MID TO UPPER 80S...POSSIBLY AROUND 90 WEST OF THE HUDSON RIVER. THERE IS A MODERATE RISK OF RIP CURRENTS...MAINLY THIS AFTERNOON THROUGH EVENING WITH ENHANCED SEA BREEZE DEVELOPMENT AND LONG PERIOD SE SWELLS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... TONIGHT...SW WINDS WILL CONTINUE TRANSPORTING HIGHER DEW POINTS ACROSS THE REGION MAKING IT FEEL UNCOMFORTABLE. WEDNESDAY...SUMMER HEAT AND HUMIDITY RETURNS WITH DAY TIME HIGH TEMPS REACHING AROUND 90 ACROSS NYC AND URBAN NORTHEAST NJ AND WITH HEAT INDEX VALUES RISING INTO THE MID AND UPPER 90S. NO EXTENDED HEAT WAVE IS FORECAST AS THE NEXT COLD FRONT APPROACHES. A WARM MOIST UNSTABLE MARITIME TROPICAL AIR MASS WILL SET THE STAGE FOR THE DEVELOPMENT OF MORE NUMEROUS SHOWERS AND TSTMS BY WED AFTERNOON MAINLY WEST AND NORTH OF NYC. INCREASED POPS TO LIKELY CATEGORY BY 6 PM. PRIMARY POTENTIAL HAZARD IS HEAVY RAIN WHICH COULD CAUSE ISOLATED FLASH FLOODING MAINLY OF LOW LYING POOR DRAINAGE AREAS. CAN NOT RULE OUT THE POTENTIAL FOR A STRONG TO POSSIBLY SEVERE TSTM WITH DAMAGING WINDS BEING THE PRIMARY THREAT. BECAUSE MORE WIDESPREAD FLASH FLOODING OR SEVERE STORMS ARE NOT FORECAST...A HAZARDOUS WEATHER OUTLOOK WILL NOT BE ISSUED AT THIS TIME FOR THESE POTENTIAL HAZARDS. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... HAVE THE POTENTIAL FOR SIGNIFICANT CONVECTION WEDNESDAY NIGHT...WITH THE PASSAGE OF A SURFACE COLD FRONT THROUGH A RATHER WARM AND HUMID AIR MASS. THERE ARE SOME INDICATIONS THAT CAPES OF 1000-1500 J/KG COULD PERSIST AT LEAST THROUGH WEDNESDAY EVENING...AND SHOWALTER INDICES OF 0 TO -2 PERSIST THROUGH THE NIGHT...ESPECIALLY OVER EASTERN PORTIONS. THIS COUPLED WITH THE REGION AT THE MINIMUM INT HE RIGHT REAR QUADRANT OF A 80+ KT UPPER LEVEL JET...AND POSSIBLY IN A COUPLED UPPER JET REGION - DEPENDING ON THE EXACT LOCATION OF THE SUBTROPICAL JET. MODELS DUE VARY ON THE LOCATION/STRENGTH OF THE LATTER. 0-6 KM BULK SHEAR IS FORECAST TO INCREASE TO 25-35 KT DURING THE EVENING SO THERE COULD BE SUFFICIENT SHEAR/CAPE FOR ISOLATED SUPER CELLS DURING THE EVENING MAINLY ACROSS NYC/NE NJ/S CT/LOWER HUDSON VALLEY ZONES. AS SUCH THERE IS THE POTENTIAL FOR STRONG TO POSSIBLY SEVERE STORMS WEDNESDAY NIGHT...MAINLY PRIOR TO 6Z. MODELS DO DIFFER ON AMOUNT/EXTENT OF PRECIPITATION ON THURSDAY DUE TO DIFFERENCES IN TIMING OF 850 HPA COLD FRONT. NAM/SREF ARE THE SLOWEST WITH THIS FEATURE. GIVEN THE PROPENSITY FOR COLD FRONTS TO HANG UP CROSSING THE MOUNTAINS...SLOWER PROGRESSION OF THE 850 COLD FRONT MAKES SOME SENSE...SO DID WEIGH POPS AND CONVECTIVE PROBABILITIES MORE TOWARDS THIS LINE OF THINKING. HOWEVER...THERE SHOULD NOT BE ENOUGH INSTABILITY FOR ANY STRONG OR SEVERE STORMS ON THURSDAY. HAVE LINGERED SLIGHT CHANCE POPS INTO THURSDAY EVENING ACROSS FAR SE ZONES...THIS MIGHT BE A TAD TOO LONG ULTIMATELY...BUT WITH OVERALL TREND WITH FRONTAL TIMING A TAD SLOWER THAN PREVIOUS FORECAST...CANNOT RULE OUT PRECIPITATION LASTING A TAD LONGER THAN CURRENTLY EXPECTED. SEE THE HYDROLOGY SECTION OF THE AFD FOR RAINFALL AMOUNTS AND POTENTIAL IMPACTS FROM TONIGHT INTO THURSDAY. FOR LOWS WEDNESDAY NIGHT USED A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER TEMPERATURES THEN ADDED A DEGREE TO WEIGH TOWARDS WARMER SOLUTIONS - WITH VALUES FORECAST TO BE A FEW DEGREES ABOVE NORMAL. FOR HIGHS THURSDAY USED A BLEND OF MIXING DOWN FROM 950-875 HPA PER BUFKIT SOUNDINGS...WITH NAM 2-METER TEMPERATURES AND A BLEND OF MAV/MET GUIDANCE...THEN ADDED 2 DEGREES TO WEIGH TOWARDS WARMER SOLUTIONS. EXPECT HIGHS TO BE AROUND A FEW DEGREES BELOW NORMAL. FOR LOWS THURSDAY NIGHT USED A BLEND OF MEX/EKD/ECE/ECM/WPC GUIDANCE WITH NAM 2-METER TEMPERATURES - WITH VALUES A FEW DEGREES BELOW NORMAL. THE REGIONS WEATHER FRIDAY-MONDAY WILL LARGELY BE DETERMINED BY THE EXACT POSITION/STRENGTH OF A RATHER LARGE CUTOFF LOW OVER EASTERN CANADA...AND WHEN SPOKES OF ENERGY ROTATING AROUND ITS BASE PASS THROUGH THE REGION. FOR NOW...IT APPEARS THE REGION SHOULD BE BETWEEN SPOKES FRIDAY AND FRIDAY NIGHT AND POSSIBLY INTO SATURDAY. SO FOR NOW HAVE GONE WITH A DRY FORECAST FROM FRIDAY-SATURDAY NIGHT. HOWEVER...THERE ARE SOME INDICATIONS THAT A SMALL SHORTWAVE COULD PASS THE AREA ON SATURDAY...POSSIBLY TRIGGERING SOME -SHRA ON SATURDAY. CONFIDENCE IN THIS IS TOO LOW TO REFLECT IN THE FORECAST AT THIS TIME. BASED ON MODEL CONSENSUS...AM MORE CONFIDENT IN A PERIOD OF UNSETTLED WEATHER SUNDAY...SUNDAY NIGHT AND MONDAY. IT WILL NOT RAIN THE ENTIRE TIME...IN FACT MOST AREAS WILL BE DRY FOR MORE TIME DURING THIS TIME FRAME THAN IT WILL RAIN AT ANY GIVEN LOCATION. GIVEN DIFFICULTY IN TIMING OF SHORTWAVE ROTATING AROUND A CUTOFF LOW THIS FAR OUT...YET ALONE INHERENT UNCERTAINTY IN MODELS HANDLING OF A CUTOFF LOW THIS FAR OUT...DO NOT WANT TO EVEN ATTEMPT ANY SORT OF TIMING - SO HAVE CHANCE POPS SUNDAY-MONDAY. FOR TEMPERATURES FRIDAY-MONDAY USED A BLEND OF MEX/EKD/ECE/ECM/WPC GUIDANCE WITH HIGHS RUNNING BELOW NORMAL...AND LOWS STARTING OUT BELOW NORMAL AND TRENDING TO NEAR NORMAL. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... HIGH PRESSURE CONTINUES TO SLOWLY MOVE OFFSHORE. VFR THROUGH MUCH OF THE TAF PERIOD. SEA BREEZE EXPECTED TO DEVELOP THIS AFTERNOON. TIMING COULD BE OFF +/- 1-2 HOURS FROM TAF. MEDIUM CONFIDENCE SEA BREEZE MAKES IT TO KEWR/KTEB...RESULTING IN WIND DIR AROUND 170-180 TRUE BY LATE AFTERNOON. A SHRA POSSIBLE ACROSS INTERIOR THIS AFTERNOON INTO EARLY EVENING. CONFIDENCE FAIRLY LOW THOUGH...SO ONLY VCSH AT KSWF. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR. KLGA FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS. KEWR FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY CLOSER TO 220 TRUE. KTEB FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY CLOSER TO 220 TRUE. KHPN FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS. KISP FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR. .OUTLOOK FOR 18Z WED THROUGH SUN... .WED AFTERNOON...PRIMARILY VFR. ISOLATED SHRA/TSTM LATE. .WED NIGHT-THU...SLOW MOVING COLD FROPA. MVFR OR LOWER CONDS IN SCT-NUMEROUS SHOWERS/TSTMS. .THU NIGHT-SAT...VFR. .SUN...CHANCE OF SHOWERS OR THUNDERSTORMS. SUB-VFR POSSIBLE. && .MARINE... MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK. WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS OF 25 KT AND 5 FT THROUGH WEDNESDAY MORNING. OCCASIONAL GUSTS TO 25 KT ARE POSSIBLE ON MAINLY THE OCEAN WATERS WEDNESDAY AFTERNOON. SUSTAINED WINDS UP TO 15 KT ARE LIKELY WEDNESDAY NIGHT AHEAD OF A COLD FRONT. FOR NOW APPEARS GUSTS AND SEAS SHOULD STAY BELOW SMALL CRAFT THRESHOLDS. THE PRESSURE GRADIENT THEN RELAXES OVER THE REGION THURSDAY AND REMAINS LIGHT INTO SATURDAY. AS A RESULT EXPECT WINDS OF 10 KT OR LESS FROM THURSDAY THROUGH SATURDAY...WITH SEAS 4 FT OR LESS ON THE COASTAL OCEAN WATERS AND 1 FT OR LESS ELSEWHERE. && .HYDROLOGY... MAINLY DRY THROUGH WEDNESDAY MORNING...THOUGH A BRIEF LOCALLY HEAVY DOWNPOUR IS POSSIBLE IN ANY STRONGER CONVECTION THIS AFTERNOON. THIS BEST CHANCE FOR THIS IS TO THE N/W OF NYC. THERE IS THE POTENTIAL FOR AROUND 1/2 INCH OF RAINFALL FROM LATE WEDNESDAY THROUGH THURSDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE. PRECIPITABLE WATERS ARE FORECAST TO BE AROUND 2 INCHES ON WEDNESDAY NIGHT...SO LOCALLY HEAVY RAINFALL IS POSSIBLE IN ANY STRONGER CONVECTION. AREAS EXPERIENCING LOCALLY HEAVY RAINFALL COULD EXPERIENCE AT LEAST MINOR FLOODING OF URBAN/POOR DRAINAGE AREA...AND POSSIBLY LOCALIZED FLASH FLOODING. THE CONFIDENCE IN THE LATTER IS CURRENTLY LESS THAN 30 PERCENT SO WILL NOT HIGHLIGHT IN THE HAZARDOUS WEATHER OUTLOOK. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...GC/MALOIT NEAR TERM...GC/MALOIT/MPS SHORT TERM...GC LONG TERM...MALOIT AVIATION...BC MARINE...GC/MALOIT HYDROLOGY...GC/MALOIT
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1228 PM EDT TUE JUL 22 2014 .SYNOPSIS... AS A HIGH PRESSURE SYSTEM MOVES SLOWLY EAST OF THE AREA TODAY...A COLD FRONT WILL APPROACH FROM THE WEST ON WEDNESDAY. THE COLD FRONT CROSSES THE AREA FROM WEDNESDAY NIGHT INTO THURSDAY MORNING...FOLLOWED BY HIGH PRESSURE BUILDING TO THE SOUTH OF LONG ISLAND INTO SATURDAY. A STORM SYSTEM THEN IMPACTS THE AREA INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WILL CUT AFTERNOON POPS DOWN FROM LOW CHANCE TO SLIGHT CHANCE AND CAP POPS AT 20 PERCENT. LATEST HRRR INDICATING ONLY SPOTTY SHOWERS...AND 12Z NAM DOES NOT HAVE MORE THAN ISOLATED COVERAGE AT BEST. SEA BREEZES CONTINUE TO WORK THEIR WAY NORTH THROUGH THE REGION. WIND SPEEDS WILL BE 10 KT OR LESS. TEMPS ACROSS LONG ISLAND AND COASTAL CT WILL EITHER HOLD STEADY OR ONLY SLOWLY WARM THROUGH THE REST OF THE AFTERNOON. OTHERWISE...SKIES WILL BE SUNNY WITH TEMPS A FEW DEGREES ABOVE NORMAL...TOPPING OFF IN THE MID TO UPPER 80S...POSSIBLY AROUND 90 WEST OF THE HUDSON RIVER. THERE IS A MODERATE RISK OF RIP CURRENTS...MAINLY THIS AFTERNOON THROUGH EVENING WITH ENHANCED SEA BREEZE DEVELOPMENT AND LONG PERIOD SE SWELLS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... TONIGHT...SW WINDS WILL CONTINUE TRANSPORTING HIGHER DEW POINTS ACROSS THE REGION MAKING IT FEEL UNCOMFORTABLE. WEDNESDAY...SUMMER HEAT AND HUMIDITY RETURNS WITH DAY TIME HIGH TEMPS REACHING AROUND 90 ACROSS NYC AND URBAN NORTHEAST NJ AND WITH HEAT INDEX VALUES RISING INTO THE MID AND UPPER 90S. NO EXTENDED HEAT WAVE IS FORECAST AS THE NEXT COLD FRONT APPROACHES. A WARM MOIST UNSTABLE MARITIME TROPICAL AIR MASS WILL SET THE STAGE FOR THE DEVELOPMENT OF MORE NUMEROUS SHOWERS AND TSTMS BY WED AFTERNOON MAINLY WEST AND NORTH OF NYC. INCREASED POPS TO LIKELY CATEGORY BY 6 PM. PRIMARY POTENTIAL HAZARD IS HEAVY RAIN WHICH COULD CAUSE ISOLATED FLASH FLOODING MAINLY OF LOW LYING POOR DRAINAGE AREAS. CAN NOT RULE OUT THE POTENTIAL FOR A STRONG TO POSSIBLY SEVERE TSTM WITH DAMAGING WINDS BEING THE PRIMARY THREAT. BECAUSE MORE WIDESPREAD FLASH FLOODING OR SEVERE STORMS ARE NOT FORECAST...A HAZARDOUS WEATHER OUTLOOK WILL NOT BE ISSUED AT THIS TIME FOR THESE POTENTIAL HAZARDS. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... HAVE THE POTENTIAL FOR SIGNIFICANT CONVECTION WEDNESDAY NIGHT...WITH THE PASSAGE OF A SURFACE COLD FRONT THROUGH A RATHER WARM AND HUMID AIR MASS. THERE ARE SOME INDICATIONS THAT CAPES OF 1000-1500 J/KG COULD PERSIST AT LEAST THROUGH WEDNESDAY EVENING...AND SHOWALTER INDICES OF 0 TO -2 PERSIST THROUGH THE NIGHT...ESPECIALLY OVER EASTERN PORTIONS. THIS COUPLED WITH THE REGION AT THE MINIMUM INT HE RIGHT REAR QUADRANT OF A 80+ KT UPPER LEVEL JET...AND POSSIBLY IN A COUPLED UPPER JET REGION - DEPENDING ON THE EXACT LOCATION OF THE SUBTROPICAL JET. MODELS DUE VARY ON THE LOCATION/STRENGTH OF THE LATTER. 0-6 KM BULK SHEAR IS FORECAST TO INCREASE TO 25-35 KT DURING THE EVENING SO THERE COULD BE SUFFICIENT SHEAR/CAPE FOR ISOLATED SUPER CELLS DURING THE EVENING MAINLY ACROSS NYC/NE NJ/S CT/LOWER HUDSON VALLEY ZONES. AS SUCH THERE IS THE POTENTIAL FOR STRONG TO POSSIBLY SEVERE STORMS WEDNESDAY NIGHT...MAINLY PRIOR TO 6Z. MODELS DO DIFFER ON AMOUNT/EXTENT OF PRECIPITATION ON THURSDAY DUE TO DIFFERENCES IN TIMING OF 850 HPA COLD FRONT. NAM/SREF ARE THE SLOWEST WITH THIS FEATURE. GIVEN THE PROPENSITY FOR COLD FRONTS TO HANG UP CROSSING THE MOUNTAINS...SLOWER PROGRESSION OF THE 850 COLD FRONT MAKES SOME SENSE...SO DID WEIGH POPS AND CONVECTIVE PROBABILITIES MORE TOWARDS THIS LINE OF THINKING. HOWEVER...THERE SHOULD NOT BE ENOUGH INSTABILITY FOR ANY STRONG OR SEVERE STORMS ON THURSDAY. HAVE LINGERED SLIGHT CHANCE POPS INTO THURSDAY EVENING ACROSS FAR SE ZONES...THIS MIGHT BE A TAD TOO LONG ULTIMATELY...BUT WITH OVERALL TREND WITH FRONTAL TIMING A TAD SLOWER THAN PREVIOUS FORECAST...CANNOT RULE OUT PRECIPITATION LASTING A TAD LONGER THAN CURRENTLY EXPECTED. SEE THE HYDROLOGY SECTION OF THE AFD FOR RAINFALL AMOUNTS AND POTENTIAL IMPACTS FROM TONIGHT INTO THURSDAY. FOR LOWS WEDNESDAY NIGHT USED A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER TEMPERATURES THEN ADDED A DEGREE TO WEIGH TOWARDS WARMER SOLUTIONS - WITH VALUES FORECAST TO BE A FEW DEGREES ABOVE NORMAL. FOR HIGHS THURSDAY USED A BLEND OF MIXING DOWN FROM 950-875 HPA PER BUFKIT SOUNDINGS...WITH NAM 2-METER TEMPERATURES AND A BLEND OF MAV/MET GUIDANCE...THEN ADDED 2 DEGREES TO WEIGH TOWARDS WARMER SOLUTIONS. EXPECT HIGHS TO BE AROUND A FEW DEGREES BELOW NORMAL. FOR LOWS THURSDAY NIGHT USED A BLEND OF MEX/EKD/ECE/ECM/WPC GUIDANCE WITH NAM 2-METER TEMPERATURES - WITH VALUES A FEW DEGREES BELOW NORMAL. THE REGIONS WEATHER FRIDAY-MONDAY WILL LARGELY BE DETERMINED BY THE EXACT POSITION/STRENGTH OF A RATHER LARGE CUTOFF LOW OVER EASTERN CANADA...AND WHEN SPOKES OF ENERGY ROTATING AROUND ITS BASE PASS THROUGH THE REGION. FOR NOW...IT APPEARS THE REGION SHOULD BE BETWEEN SPOKES FRIDAY AND FRIDAY NIGHT AND POSSIBLY INTO SATURDAY. SO FOR NOW HAVE GONE WITH A DRY FORECAST FROM FRIDAY-SATURDAY NIGHT. HOWEVER...THERE ARE SOME INDICATIONS THAT A SMALL SHORTWAVE COULD PASS THE AREA ON SATURDAY...POSSIBLY TRIGGERING SOME -SHRA ON SATURDAY. CONFIDENCE IN THIS IS TOO LOW TO REFLECT IN THE FORECAST AT THIS TIME. BASED ON MODEL CONSENSUS...AM MORE CONFIDENT IN A PERIOD OF UNSETTLED WEATHER SUNDAY...SUNDAY NIGHT AND MONDAY. IT WILL NOT RAIN THE ENTIRE TIME...IN FACT MOST AREAS WILL BE DRY FOR MORE TIME DURING THIS TIME FRAME THAN IT WILL RAIN AT ANY GIVEN LOCATION. GIVEN DIFFICULTY IN TIMING OF SHORTWAVE ROTATING AROUND A CUTOFF LOW THIS FAR OUT...YET ALONE INHERENT UNCERTAINTY IN MODELS HANDLING OF A CUTOFF LOW THIS FAR OUT...DO NOT WANT TO EVEN ATTEMPT ANY SORT OF TIMING - SO HAVE CHANCE POPS SUNDAY-MONDAY. FOR TEMPERATURES FRIDAY-MONDAY USED A BLEND OF MEX/EKD/ECE/ECM/WPC GUIDANCE WITH HIGHS RUNNING BELOW NORMAL...AND LOWS STARTING OUT BELOW NORMAL AND TRENDING TO NEAR NORMAL. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... HIGH PRESSURE WILL SLOWLY MOVE OFFSHORE TODAY. VFR WITH LIGHT W/SW FLOW THIS MORNING. SEA BREEZE LATE THIS MORNING INTO AFTERNOON. TIMING COULD BE OFF +/- 1-2 HOURS FROM TAF. MEDIUM CONFIDENCE SEA BREEZE MAKES IT TO KEWR/KTEB...RESULTING IN WIND DIR AROUND 170-180 TRUE BY LATE AFTERNOON. A SHRA POSSIBLE ACROSS INTERIOR LATE AFTERNOON INTO EARLY EVENING. CONFIDENCE FAIRLY LOW THOUGH...SO ONLY VCSH AT KSWF. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR. KLGA FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS. GUSTS INDICATED IN TAF MAY BE MORE OCCASIONAL IN FREQUENCY. KEWR FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY CLOSER TO 220 TRUE. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY CLOSER TO 220 TRUE. KHPN FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS. KISP FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR. .OUTLOOK FOR 12Z WED THROUGH SAT... .WED...PRIMARILY VFR. BRIEF MVFR VSBY POSSIBLE EARLY WED...ESP INTERIOR AND EASTERN TERMINALS. ISOLATED SHRA/TSTM NW OF THE NY METRO LATE. .WED NIGHT-THU...SLOW MOVING COLD FROPA. MVFR OR LOWER CONDS IN SCT-NUMEROUS SHOWERS/TSTMS. .THU NIGHT-SAT...VFR. && .MARINE... MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK. WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS OF 25 KT AND 5 FT THROUGH WEDNESDAY MORNING. OCCASIONAL GUSTS TO 25 KT ARE POSSIBLE ON MAINLY THE OCEAN WATERS WEDNESDAY AFTERNOON. SUSTAINED WINDS UP TO 15 KT ARE LIKELY WEDNESDAY NIGHT AHEAD OF A COLD FRONT. FOR NOW APPEARS GUSTS AND SEAS SHOULD STAY BELOW SMALL CRAFT THRESHOLDS. THE PRESSURE GRADIENT THEN RELAXES OVER THE REGION THURSDAY AND REMAINS LIGHT INTO SATURDAY. AS A RESULT EXPECT WINDS OF 10 KT OR LESS FROM THURSDAY THROUGH SATURDAY...WITH SEAS 4 FT OR LESS ON THE COASTAL OCEAN WATERS AND 1 FT OR LESS ELSEWHERE. && .HYDROLOGY... MAINLY DRY THROUGH WEDNESDAY MORNING...THOUGH A BRIEF LOCALLY HEAVY DOWNPOUR IS POSSIBLE IN ANY STRONGER CONVECTION THIS AFTERNOON. THIS BEST CHANCE FOR THIS IS TO THE N/W OF NYC. THERE IS THE POTENTIAL FOR AROUND 1/2 INCH OF RAINFALL FROM LATE WEDNESDAY THROUGH THURSDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE. PRECIPITABLE WATERS ARE FORECAST TO BE AROUND 2 INCHES ON WEDNESDAY NIGHT...SO LOCALLY HEAVY RAINFALL IS POSSIBLE IN ANY STRONGER CONVECTION. AREAS EXPERIENCING LOCALLY HEAVY RAINFALL COULD EXPERIENCE AT LEAST MINOR FLOODING OF URBAN/POOR DRAINAGE AREA...AND POSSIBLY LOCALIZED FLASH FLOODING. THE CONFIDENCE IN THE LATTER IS CURRENTLY LESS THAN 30 PERCENT SO WILL NOT HIGHLIGHT IN THE HAZARDOUS WEATHER OUTLOOK. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...GC/MALOIT NEAR TERM...GC/MALOIT/MPS SHORT TERM...GC LONG TERM...MALOIT AVIATION...BC/PICCA MARINE...GC/MALOIT HYDROLOGY...GC/MALOIT
AREA FORECAST DISCUSSION
NWS POCATELLO ID
149 PM MDT TUE JUL 22 2014 .DISCUSSION...EAST IDAHO REMAINS UNDER INFLUENCE OF SOUTHWEST FLOW TODAY AND TONIGHT. SHORTWAVE PUSHING NORTHEAST FROM CALIFORNIA WORKING WITH DEEP LOW OFF BC CANADA COAST TO MAINTAIN MOIST FLOW INTO WESTERN PORTIONS OF STATE INCLUDING CENTRAL MOUNTAINS. ALREADY SEEING BROAD CUMULUS FIELD ACROSS CENTRAL MOUNTAINS ALONG WITH CIRRUS SHIELD EXTENDING SOUTHWEST TOWARD CALIFORNIA FEATURE. RADAR PICKING UP WEAK RETURNS OVER PAHSIMEROI AND LEMHI REGIONS EARLY THIS AFTERNOON. NAM AND GFS CONTINUE TO PRODUCE SCATTERED CONVECTIVE DEVELOPMENT WITHIN THIS ZONE THOUGH RECENT HRRR RUNS LESS FAVORABLE FOR CONVECTION ACROSS THE REGION. MODELS MAINTAIN RELATIVELY THIN BAND OF ACTIVITY OVERNIGHT JUST ALONG WESTERN EDGE OF FORECAST AREA BOUNDARIES SO WILL KEEP LOWER POPS THROUGH THE CENTRAL MTNS OVERNIGHT AND INTO WEDNESDAY MORNING. ELSEWHERE MUCH DRIER FLOW IN PLACE WITH PWAT VALUES DROPPING SIGNIFICANTLY OVERNIGHT THROUGH THE SNAKE PLAIN AND SOUTHERN/EASTERN HIGHLANDS. STRENGTHENING SURFACE LOW EJECTS NORTH INTO SOUTHERN IDAHO OVERNIGHT WITH GOOD SOUTHERLY FLOW ACROSS THE REGION HELPING TO ENHANCE DRYING. FLOW TURNS SOUTHWEST DURING THE DAY WEDNESDAY AS NORTHERN LOW CENTER REACHES PACNW COAST AND DRY PUNCH EXTENDS ACROSS MOST OF EASTERN IDAHO. HAVE KEPT WEAK POPS ACROSS CENTRAL MOUNTAINS BUT CONFIDENCE IS LOW FOR PRECIP CHANCES WITH DRY UPSTREAM FLOW ON WV SAT IMAGERY. BREEZY CONDITIONS EXPECTED BUT MARGINAL AT THIS TIME FOR EVEN LAKE WIND CONCERNS. UPPER LOW EJECTS EAST ALONG CANADIAN BORDER THROUGH THURSDAY...PUSHING DRY COLD FRONT THROUGH THE REGION EARLY IN THE DAY. COOLER BUT WINDIER DAY ON THURSDAY WITH SOME CONCERNS FOR FIRE /SEE DISCUSSION BELOW/. GUIDANCE SHOWING WIDE SPREAD IN WIND VALUES SO WILL LEAVE CURRENT GRIDS JUST BELOW ADVISORY CONDITIONS AT THIS TIME. FRIDAY THROUGH SUNDAY RIDGE REBOUNDS THROUGH THE INTERMOUNTAIN WEST. WARMER TEMPS AND DRY CONDITIONS WILL CONTINUE. MODELS STILL HINTING AT SOME HINT OF A RETURN TO MONSOONAL TYPE FLOW BY MONDAY. GFS AND ECMWF DIFFER SLIGHTLY IN AMOUNT OF CONVECTION AND SPREAD MONDAY INTO TUESDAY. BELIEVE ISOLATED POPS OVER HIGHER ELEVATIONS WILL SUFFICE FOR NOW UNTIL CLEARER PICTURE DEVELOPS. DMH && .AVIATION...VFR CONDITIONS EXPECTED THROUGH THE PERIOD AT ALL TAF SITES. THUNDERSTORMS ARE EXPECTED ONCE AGAIN IN THE CENTRAL MOUNTAINS BUT WILL LIKELY BE NORTH OF KSUN SO KEPT IN A MENTION OF VCTS. OTHERWISE...WINDY CONDITIONS ARE EXPECTED TO SET UP WEDNESDAY AFTERNOON AND ESPECIALLY THURSDAY AFTERNOON. EP && .FIRE WEATHER...LINGERING THUNDERSTORMS CAN BE EXPECTED TODAY IN THE CENTRAL MOUNTAINS AS AN UPPER LOW BEGINS TO MOVE INLAND IN WASHINGTON STATE. THE REST OF THE AREA WILL BE UNDER DRIER AIR MOVING IN FROM THE SOUTH. A DRYING TREND IS EXPECTED TO BEGIN FOR THE ENTIRE AREA WEDNESDAY AS THAT UPPER LOW MOVES ALONG THE CANADIAN BORDER...AND LAST THROUGH AT LEAST SATURDAY. AS THE LOW MOVES PAST THE AREA...A DRY COLD FRONT WILL PASS THROUGH SE ID LATE WEDNESDAY NIGHT INTO THURSDAY MORNING WHICH WILL DECREASE RH VALUES AND INCREASE WINDS SIGNIFICANTLY IN THE AFTERNOON. CURRENTLY HAVE A FIRE WEATHER WATCH OUT FOR ALL CRITICAL ZONES FOR THURSDAY AFTERNOON FOR THE POTENTIAL OF A RED FLAG DAY OCCURRING AS A RESULT OF LOW RH AND HIGH WINDS. EP && .PIH WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING IDZ410-425. FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING IDZ422-427. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
306 PM EDT TUE JUL 22 2014 .SYNOPSIS... ISSUED AT 306 PM EDT TUE JUL 22 2014 HOT AND HUMID WEATHER WILL PERSIST LATE THIS AFTERNOON INTO EARLY THIS EVENING IN ADVANCE OF A COLD FRONT. THIS COLD FRONT WILL SWING THROUGH TONIGHT INTO WEDNESDAY MORNING WITH SHOWERS AND THUNDERSTORMS POSSIBLE ALONG IT. COOLER AND DRIER AIR WILL FILTER IN LATER WEDNESDAY THROUGH THE END OF THE WEEK...WITH STORM CHANCES AND WARMER TEMPERATURES RETURNING THIS WEEKEND. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 306 PM EDT TUE JUL 22 2014 REGIONAL RADARS SHOWING ONGOING CONVECTION CONTINUES TO MOVE ACROSS FAR NORTHERN GREAT LAKES/SOUTHERN CANADA WITH SURFACE LOW WHILE EARLIER MCS DISSIPATING OVER THE MID MISSISSIPPI VALLEY WITH NEW CELLS STARTING TO FORM OVER IOWA THIS AFTERNOON. WATER VAPOR IMAGERY AND LATEST RUC ANALYSIS SHOWS SHORT WAVE TROF MOVING ACROSS LAKE SUPERIOR WITH UPPER JET WELL TO THE NORTH OVER THE HUDSON BAY. THIS DETACHMENT OF UPPER FORCING WILL BE PROBLEMATIC FOR CONVECTION MAINTAINING ALONG THE COLD FRONT AS IT MOVES THROUGH OVERNIGHT. BEST CHANCES APPEAR TO BE IN THE NW CWA AS DECENT MASS CONVERGENCE ALONG COLD FRONT WILL COMBINE WITH MODEST ELEVATED INSTABILITY...CAPES AROUND 1500J/KG...SO IF CONVECTION IN IOWA IS ABLE TO BECOME MORE ORGANIZED IT MAY HAVE ENOUGH SUPPORT TO MAINTAIN CONVECTIVE COMPLEX...HOWEVER FORMING RIGHT ALONG THICKNESS RIDGE WILL HAVE SOME UNCERTAINTY IN ITS FORWARD PROPAGATION. FRONT EXPECTED TO PUSH THROUGH MUCH OF THE CWA BY WEDNESDAY MORNING WITH JUST LINGERING CHANCES IN THE FAR SE CWA...TRENDING TOWARD A DRY FORECAST FOR THE ENTIRE AREA BY AFTERNOON. WARM AND MUGGY CONDITIONS EXPECTED TONIGHT FOR THE SE HALF WITH LOWS AROUND 70 WHILE FRONTAL PASSAGE WILL ALLOW TEMPS TO DROP INTO THE MID 60S NW. COOLER AND LESS HUMID FOR WEDNESDAY WITH HIGHS 75-80. && .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 306 PM EDT TUE JUL 22 2014 COMFORTABLE/FAIR WX WILL PREVAIL WEDNESDAY NIGHT THROUGH FRIDAY MORNING AS STABLE CANADIAN HIGH PRESSURE DROPS THROUGH. MID-UPPER LEVEL FLOW WILL BRIEFLY TRANSITION TO A FLATTER/SEMI-ZONAL WNW REGIME BY LATE FRIDAY INTO SATURDAY...WHILE IN THE LOW LEVELS WINDS VEER MORE SOUTHERLY ALLOWING AN ACTIVE WARM FRONT TO WORK ENE INTO THE REGION. LEAD/WEAK SHORTWAVE IN ADVANCE OF PRIMARY SHORTWAVE TROUGH AND INCREASING MASS/MOISTURE CONVERGENCE ALONG THE DEVELOPING FRONT SUPPORT INHERITED CHANCE POPS FOR SHOWERS/STORMS DURING THIS TIME...MAINLY LATER FRIDAY NIGHT INTO SATURDAY. RE-AMPLIFICATION OF EASTERN CONUS TROUGH REMAINS A CONSISTENT SIGNAL IN MODEL GUIDANCE SUNDAY INTO EARLY NEXT WEEK. COLD FRONT ON LEADING EDGE OF HEIGHT FALLS MAY SUPPORT ANOTHER ROUND OF CONVECTION LATER SATURDAY NIGHT-SUNDAY DEPENDING ON TIMING. UNSEASONABLY COOL AND MAINLY DRY WX LIKELY RETURNS EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 123 PM EDT TUE JUL 22 2014 DAYTIME MIXING HAS WINDS STARTING TO GUST THIS AFTERNOON...WITH BETTER GRADIENT APPROACHING FROM THE NORTHWEST WILL CARRY A G22 AT KSBN THIS AFTERNOON BUT NOT MENTION AT KFWA. COLD FRONT APPROACHING THIS EVENING AND MOVING THROUGH OVERNIGHT WILL A SMALL CHANCE FOR SH/TSRA INTO THE AREA...BETTER INSTABILITY TO ACCOMPANY FRONT IN NW CWA SO WILL HAVE A TEMPO AT KSBN BUT LEAVE OUT ANY MENTION OF THUNDER FOR NOW. AMPLE LOW LEVEL MOISTURE BEHIND FRONT COULD MAKE FOR MVFR CIGS EARLY MORNING ON WEDNESDAY...STRONG GRADIENT AS WELL WITH NW WINDS AROUND 15KTS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR INZ003. MI...BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR MIZ077. OH...NONE. LM...SMALL CRAFT ADVISORY FROM 4 AM WEDNESDAY TO 8 AM EDT THURSDAY FOR LMZ043-046. && $$ SYNOPSIS...STEINWEDEL SHORT TERM...JAL LONG TERM...STEINWEDEL AVIATION...JAL VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
234 PM MDT TUE JUL 22 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 1255 PM MDT TUE JUL 22 2014 18Z WATER VAPOR IMAGERY INDICATED LARGE UPPER LEVEL RIDGE CENTERED OVER NEW MEXICO WITH RUC ANALYSIS INDICATING A 600 DM RIDGE IN PLACE AT H5. AT THE SFC...OUTFLOW BOUNDARY HAS STALLED ACROSS THE EXTREME SOUTHERN CWA...BETWEEN TRIBUNE AND LEOTI EXTENDING NORTHEAST TOWARDS HILL CITY. MAIN CONCERNS FOR THE SHORT TERM WILL BE TEMPS AND PRECIP CHANCES THIS EVENING AND TOMORROW AFTERNOON. LACK OF ANY MEANINGFUL CU FIELD AT 19Z LOWERS OVERALL CONFIDENCE IN LATE AFTERNOON THUNDERSTORM FORECAST AND WHILE AN ISOLATED STORM IS STILL POSSIBLE...HAVE DOUBTS THAT ANYTHING WILL FIRE ALONG REMAINING OUTFLOW BOUNDARY. WITH H85-H7 WAA INCREASING TONIGHT...IT WILL BE POSSIBLE FOR STORMS COMING OUT OF THE NORTHWEST TO MAINTAIN THEMSELVES BUT WITH WEAK WINDS THROUGHOUT THE COLUMN STORM MOTION WOULD BE SLOW. A FEW MODELS SUGGEST ELEVATED CONVECTION DEVELOPING AFTER 06Z AND WHILE THE FORCING WILL BE THERE...CONDENSATION PRESSURE DEFICITS AND PRESSURE ADVECTION VALUES ON 310 AND 315K SURFACES WOULD SUGGEST SATURATION UNLIKELY. IF STORMS/CLOUDS CANNOT DEVELOP...BACKED EASTERLY FLOW WITH A 100MB POCKET OF LOW LEVEL MOISTURE WOULD SUPPORT AT LEAST PATCHY FOG PRIOR TO 15Z. GENERAL CONSENSUS OF MODELS SUGGESTS TEMPERATURES AROUND 5 DEGREES COOLER ON WEDNESDAY THAN TODAY...GIVEN EXPECTED SFC PATTERN THAT APPEARS REASONABLE. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 231 PM MDT TUE JUL 22 2014 A RIDGE OVER THE ROCKIES/PLAINS WILL SHIFT TO THE DESERT SOUTHWEST BY FRIDAY. A SURFACE TROUGH WILL BE IN EASTERN COLORADO FROM WEDNESDAY NIGHT UNTIL IT SHIFTS INTO SOUTHWEST KANSAS FRIDAY. THE SURFACE TROUGH WILL FOCUS THUNDERSTORM DEVELOPMENT WEDNESDAY EVENING. A SHORTWAVE MOVES INTO THE AREA WILL PROVIDE FORCING. CAPE WILL RANGE FROM 1000 TO 2000J/KG AND SHEAR WILL BE 20KTS. FORECAST SOUNDINGS INDICATE AN OVERALL LACK OF MID LEVEL MOISTURE SO WILL CONTINUE SLIGHT CHANCE POPS. FOR THURSDAY AFTERNOON AND EVENING, THE SURFACE TROUGH WILL BE ORIENTED ACROSS NORTHWEST KANSAS BUT ONCE AGAIN FORECAST SOUNDINGS SHOW HIGH BASED MOISTURE AROUND 600MB. CAPE RANGES FROM 200J/KG IN EASTERN COLORADO TO 800J/KG IN THE EAST. DUE TO THESE MARGINAL PARAMETERS WILL STAY WITH SLIGHT CHANCE POPS WITH COVERAGE OVER THE ENTIRE FA AS THE TROUGH SHIFTS SOUTH DURING THE EVENING. SURFACE CONVERGENCE AND HEATING WILL BE THE MAIN FORCING FRIDAY AFTERNOON WITH THE TROUGH WELL TO THE SOUTH OF THE FA. STORMS SHOULD INITIATE ON THE HIGHER TERRAIN IN EASTERN COLORADO WHERE LIFT WILL BE MAXIMIZED. SLIGHT CHANCE POPS WILL CONTINUE FOR FRIDAY AFTERNOON. MAX TEMPERATURES WILL REACH THE UPPER 90S THURSDAY AND FRIDAY. MIN TEMPERATURES WILL COOL TO THE UPPER 60S WITH AROUND 70 IN THE EAST. IN THE EXTENDED...(FRIDAY NIGHT THROUGH TUESDAY)... THE RIDGE OVER THE SOUTHERN ROCKIES WITH SHIFT TO THE DESERT SOUTHWEST BY SATURDAY AND CONTINUE THROUGH TUESDAY. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS FRIDAY/SATURDAY WITH STORMS DEVELOPING DUE TO UPSLOPE WIND/SURFACE CONVERGENCE OVER THE HIGHER TERRAIN IN EASTERN COLORADO. THESE STORMS WILL MOVE SLOWLY EAST INTO NORTHWEST KANSAS. NUMEROUS WEAK DISTURBANCES IN NORTHWEST FLOW WILL PROVIDE FORCING FOR AT LEAST A SLIGHT CHANCE/CHANCE OF THUNDERSTORMS EACH DAY FROM SUNDAY THROUGH TUESDAY. MIN TEMPERATURES WILL RANGE FROM 65 TO 70 FRIDAY AND SATURDAY NIGHTS COOLING TO THE MID 60S SUNDAY AND MONDAY NIGHTS. MAX TEMPERATURES WILL REACH THE MID 90S SATURDAY COOLING TO THE UPPER 80S FROM SUNDAY THROUGH TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1137 AM MDT TUE JUL 22 2014 THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON AND INTO THE EVENING...BUT OVERALL PROBABILITIES TOO LOW AT THIS POINT IN TIME TO INCLUDE IN TAFS. SMALL THREAT FOR FOG DEVELOPMENT AFTER 09Z ACROSS NORTHERN HALF OF AREA. STILL A FAIR BIT OF DISCREPANCY WITH RESPECT TO EXPECTED MOISTURE PROFILES...SO HAVE LIMITED IMPACT ON AVIATION CATEGORIES. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ003-004-015-016- 029. CO...NONE. NE...NONE. && $$ SHORT TERM...JRM LONG TERM...FS AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
107 PM MDT TUE JUL 22 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 1255 PM MDT TUE JUL 22 2014 18Z WATER VAPOR IMAGERY INDICATED LARGE UPPER LEVEL RIDGE CENTERED OVER NEW MEXICO WITH RUC ANALYSIS INDICATING A 600 DM RIDGE IN PLACE AT H5. AT THE SFC...OUTFLOW BOUNDARY HAS STALLED ACROSS THE EXTREME SOUTHERN CWA...BETWEEN TRIBUNE AND LEOTI EXTENDING NORTHEAST TOWARDS HILL CITY. MAIN CONCERNS FOR THE SHORT TERM WILL BE TEMPS AND PRECIP CHANCES THIS EVENING AND TOMORROW AFTERNOON. LACK OF ANY MEANINGFUL CU FIELD AT 19Z LOWERS OVERALL CONFIDENCE IN LATE AFTERNOON THUNDERSTORM FORECAST AND WHILE AN ISOLATED STORM IS STILL POSSIBLE...HAVE DOUBTS THAT ANYTHING WILL FIRE ALONG REMAINING OUTFLOW BOUNDARY. WITH H85-H7 WAA INCREASING TONIGHT...IT WILL BE POSSIBLE FOR STORMS COMING OUT OF THE NORTHWEST TO MAINTAIN THEMSELVES BUT WITH WEAK WINDS THROUGHOUT THE COLUMN STORM MOTION WOULD BE SLOW. A FEW MODELS SUGGEST ELEVATED CONVECTION DEVELOPING AFTER 06Z AND WHILE THE FORCING WILL BE THERE...CONDENSATION PRESSURE DEFICITS AND PRESSURE ADVECTION VALUES ON 310 AND 315K SURFACES WOULD SUGGEST SATURATION UNLIKELY. IF STORMS/CLOUDS CANNOT DEVELOP...BACKED EASTERLY FLOW WITH A 100MB POCKET OF LOW LEVEL MOISTURE WOULD SUPPORT AT LEAST PATCHY FOG PRIOR TO 15Z. GENERAL CONSENSUS OF MODELS SUGGESTS TEMPERATURES AROUND 5 DEGREES COOLER ON WEDNESDAY THAN TODAY...GIVEN EXPECTED SFC PATTERN THAT APPEARS REASONABLE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 136 AM MDT TUE JUL 22 2014 FOR THE PERIODS WEDNESDAY THROUGH THURSDAY NIGHT...THE FORECAST AREA WILL CONTINUE TO SEE MAINLY HOT AND DRY CONDITIONS WITH BROAD H5 RIDGE OVER THE CENTRAL PORTION OF THE COUNTRY. THERE WILL BE THE CHANCE FOR LATE AFTERNOON/EARLY EVENING CONVECTION DURING THIS TIME AS CWA WILL SEE FRONTAL BOUNDARY WEDNESDAY AND LEE-SIDE TROUGH AFFECT THE REGION THURSDAY/THURSDAY NIGHT. GOING FOR MAINLY SLIGHT CHANCE POPS FOR CONVECTION DURING THIS TIME. FRONT ON WEDNESDAY WILL MAINLY AFFECT NORTHERN ZONES BASED ON LATEST GUIDANCE BEFORE FALLING APART BY 00Z THURSDAY. WESTERN ZONES THURSDAY WILL SEE TRW CHANCES FIRST BEFORE SYSTEM SHIFTS EAST GIVING EASTERN ZONES BETTER CHANCE FOR PRECIPITATION. 925 MB TEMPS THRU PERIOD WILL RANGE IN THE +30 TO +36C WHICH GIVE 90S TO THE AREA...BUT WILL BE CLOUD DEPENDENT FROM EXPECTED PRECIPITATION. THE LAST WEEKEND OF JULY WILL BE AN ACTIVE ONE WITH CHANCES FOR THUNDERSTORMS AND COOLING TREND TOWARDS NEXT WEEK. ON THE SYNOPTIC SCALE FLOW WILL BE NEAR-ZONAL AT MID AND UPPER LEVELS ACROSS THE CENTRAL HIGH PLAINS. THE UPPER HIGH THAT IS OVER THE REGION TODAY SLOWLY RETROGRADES SOUTHWESTWARD INTO THE FOUR CORNERS REGION. AT THE SAME TIME A LONGWAVE TROUGH WILL BEGIN TO DIG INTO THE EASTERN THIRD OF THE CONUS...RESULTING IN NORTHWESTERLY FLOW AS A RIDGE DEVELOPS OVER THE NORTHERN GREAT BASIN REGION. FRIDAY WILL PROBABLY BE THE LAST DAY IN THE FORECAST PERIOD WITH A CHANCE OF SEEING TRIPLE DIGIT TEMPS. A WEAK COLD FRONT DROPS SOUTH THROUGH THE REGION LATE FRIDAY WHICH IS NOT EXPECTED TO IMPACT TEMPS MUCH INITIALLY...BUT THE BOUNDARY COULD SERVE AS A FOCUS FOR STORMS MAINLY SOUTH OF INTERSTATE 70 LATE IN THE DAY AND INTO THE EVENING AS A MID-LEVEL SHORTWAVE TROUGH MOVES ACROSS EASTERN COLORADO INTO WESTERN KANSAS PROVIDING AMPLE UPWARD MOTION FOR BOTH ISOLATED STORMS ALONG THE FRONT AND TERRAIN-BASED CONVECTION. SOUNDINGS QUICKLY STABILIZE OVERNIGHT...SO ANY STORMS THAT CAN POP UP WILL NOT LAST LONG. SATURDAY WILL BE NOT AS HOT WITH A PRETTY GOOD CHANCE FOR STORMS...WITH THE BEST CHANCE IN EASTERN COLORADO AND ADJACENT COUNTIES IN WESTERN KANSAS AND SOUTHWEST NEBRASKA. MOST OF THE DAY WILL BE DRY...BUT AS INSTABILITY INCREASES TO 1500-2000+ J/JG MUCAPE /UNCAPPED/ WITH STEEP LOW LEVEL LAPSE RATES AND AROUND 40 KTS EFFECTIVE SHEAR...STRONG TO SEVERE THUNDERSTORMS WILL BE A POSSIBILITY. THE 00Z CYCLE GUIDANCE IS A BIT SLOWER ON THE LARGE SCALE LIFT ARRIVAL COMPARED TO PAST RUNS...BUT IN THIS ENVIRONMENT WE WILL NOT NEED MUCH TO GET STORMS GOING. THE COLD FRONT FROM LATE FRIDAY IS EXPECTED TO BE SITTING IN AN EAST-WEST FASHION SOMEWHERE ACROSS WESTERN KANSAS...AND IN THIS VICINITY WOULD BE THE BEST CHANCE FOR INITIAL DEVELOPMENT. AS LONG AS STORMS DEVELOP THEY ARE EXPECTED TO LAST INTO THE OVERNIGHT HOURS...WITH A 25-30KT LOW LEVEL JET AND PLENTY OF ELEVATED CAPE TO KEEP THINGS GOING. STORM MOTIONS TOWARDS THE SOUTHEAST AT 10 TO 15 KTS SHOULD BE ENOUGH TO PRECLUDE A MAJOR FLASH FLOOD THREAT. HIGHS IN THE MID 90S. SUNDAY EXPECT ANY ONGOING OVERNIGHT PRECIP TO END BY SUNRISE AS COOLER...WITH ANOTHER ROUND OF MORE STRATIFORM RAIN WITH ISOLATED THUNDER TO MOVE IN LATE IN THE DAY. GFS DETERMINISTIC IS A DRY OUTLIER IN THIS SCENARIO...BUT GEFS MEMBERS AGREE WELL WITH ECMWF/GEM FOR A SCATTERED SHOWERS/STORMS SCENARIO. INSTABILITY IS NOT EXTREME...SO THIS WILL NOT BE AS INTENSE OF AN EVENT AS SATURDAY/SATURDAY NIGHT...BUT COULD SEE CLOUDS KEEPING THINGS SOCKED IN MUCH OF THE DAY WITH OFF AND ON SHOWERS. HIGHS RELATIVELY COOLER...ESPECIALLY IF CLOUD COVER IS MORE THAN EXPECTED...IN THE LOW 90S. MONDAY WILL BE COOLER WITH THE CHANCE FOR SHOWERS/STORMS CONTINUING DURING THE DAY. AS WITH SUNDAY THE GFS DETERMINISTIC IS VERY DRY...BUT GIVEN CLIMO POPS ARE IN THE LOW 20S FELT POPS IN THE MID 20S WAS JUST FINE GIVEN THE INHERENT UNCERTAINTY FOR A DAY 7 FORECAST. TEMPS COOLER...AGAIN ESPECIALLY SO IF CLOUDS STICK AROUND FOR MOST THE DAY...WITH HIGHS IN THE UPPER 80S TO NEAR 90. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1137 AM MDT TUE JUL 22 2014 THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON AND INTO THE EVENING...BUT OVERALL PROBABILITIES TOO LOW AT THIS POINT IN TIME TO INCLUDE IN TAFS. SMALL THREAT FOR FOG DEVELOPMENT AFTER 09Z ACROSS NORTHERN HALF OF AREA. STILL A FAIR BIT OF DISCREPANCY WITH RESPECT TO EXPECTED MOISTURE PROFILES...SO HAVE LIMITED IMPACT ON AVIATION CATEGORIES. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ003-004-015-016- 029. CO...NONE. NE...NONE. && $$ SHORT TERM...JRM LONG TERM...JJM AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
155 PM EDT TUE JUL 22 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 325 AM EDT TUE JUL 22 2014 IT WILL BE VERY WARM AND QUITE HUMID TODAY. A COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND TONIGHT. A SIGNIFICANTLY COOLER AND DRIER AIR MASS WILL MOVE IN BEHIND THAT FRONT FOR MID TO LATE WEEK. && .UPDATE... ISSUED AT 1115 AM EDT TUE JUL 22 2014 NO MAJOR CHANGES TO THE GOING FCST FOR TODAY AND TONIGHT. OUR MAIN FOCUS IS ON CONVECTIVE POTENTIAL AND SEVERE THREAT FOR LATE THIS AFTERNOON INTO THE EARLY OVERNIGHT HOURS. QUIET WEATHER ACROSS THE ENTIRE CWFA THIS MORNING...AND THIS IS EXPECTED TO CONTINUE INTO MID AFTERNOON. BAND OF CLOUDS LEFT OVER FROM CONVECTION OUT WEST LAST NIGHT IS MOVING INTO THE NW CORNER OF THE CWFA. THIS IS MAINLY MID LEVEL CLOUD COVER PER THE RADAR AND SFC OBS. NOT MUCH INSTABILITY HAS DEVELOPED YET OVERHEAD. WE CONTINUE TO EXPECT THAT THE NW CORNER OF THE CWFA WILL SEE A DECENT CHC OF CONVECTION AFTER AROUND 21Z OR SO...AND THEN SPREAD SOUTH AND EAST THROUGH THE AREA THEREAFTER. THE MAIN INSTABILITY AXIS IS IMMEDIATELY AHEAD OF THE SFC FRONT LOCATED FROM THE WRN U.P. TO NE IA AS OF 15Z THIS MORNING. THIS WILL SHIFT INTO OUR AREA AS THE LLJ/MAIN MOISTURE TRANSPORT SLIDES IN LATER THIS AFTERNOON AND THIS EVENING. WE WILL SEE SOME DIURNAL INSTABILITY DEVELOP OVERHEAD BEFORE THAT TIME...HOWEVER IT WILL REMAIN GREATLY CAPPED THROUGH MID AFTERNOON. MODEL CONSENSUS SHOWS THAT THE WRN AREAS OF THE CWFA SHOULD SEE 1500-2000 J/KG OF ML AND MU CAPE NOSE INTO THE AREA BY 00Z AND SHIFT SOUTH OF THE AREA BY 06Z VIA AN ELEVATED MIXED LAYER. THE BETTER INSTABILITY IS DEFINITELY WEST OF THE AREA...AND THE BETTER DYNAMICS REMAIN NORTH OF THE AREA. WE DO SEE A SHORT WAVE ACROSS SD THAT APPROACHES THIS EVENING AND WILL LIKELY HELP TO SUPPORT CONVECTION OVER THE AREA. WE BELIEVE THAT THE SEVERE THREAT REMAINS POSSIBLE ACROSS THE AREA...ESPECIALLY ACROSS THE WRN HALF OF THE CWFA SIMILAR TO THE THINKING OF SPC PER THE SWODY1 OUTLOOK. DEEP LAYER SHEAR HAS TRENDED MORE FAVORABLE DURING THE EXPECTED TIME OF CONVECTION PEAKING AT AROUND 30-35 KNOTS...HIGHEST WEST WHERE THE BEST INSTABILITY WILL BE OVER THE AREA. LOW LEVEL INVERSION HEIGHTS ARE NOT EXPECTED TO BE ALL THAT HIGH...SO A WIND THREAT WILL BE POSSIBLE WITH 40 KNOTS IN THE MID LEVELS AND A 30+ KNOT LLJ PRESENT DURING THE TIME OF CONVECTION. LARGE HAIL WILL BE POSSIBLE WITH FAIRLY THICK CAPE IN THE -10C TO -30C LAYER. WE ALSO AGREE WITH SPC ABOUT THE POSSIBILITY OF A TORNADO WITH 0-1KM SHEAR OF 20-25 KNOTS AND 0-1KM HELICITY VALUES 150+ M2/S2. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 325 AM EDT TUE JUL 22 2014 OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE CONVECTIVE/SEVERE WX POTENTIAL THIS AFTERNOON THROUGH TONIGHT. IT WILL BE HOT AND HUMID TODAY WITH SOME SUN AND STRONG SSW FLOW WAA HELPING TO BOOST MAX TEMPS INTO THE 85 TO 90 DEGREE RANGE THIS AFTERNOON WITH DEW POINTS REACHING THE MID TO UPPER 60S. WE EXPECT SEVERE CONVECTION OVER MN AND EXTREME NW WI EARLY THIS MORNING TO TRACK ACROSS FAR NORTHERN WI AND THE U.P. THIS MORNING. HOWEVER THAT ACTIVITY WILL STAY WELL TO THE NW OF OUR FCST AREA. HOWEVER WE EXPECT A FEW SHOWERS AND TSTORMS TO DEVELOP OVER OUR FAR NW FCST AREA BY LATE AFTN AS THE COLD FRONT MOVES INTO THAT AREA. THE COLD FRONT WILL THEN MOVE QUICKLY ACROSS THE REST OF OUR FCST AREA DURING THE MID TO LATE EVENING HOURS BRINGING SCATTERED SHOWERS AND STORMS. ISOLATED STRONG TO MARGINALLY SEVERE STORMS ARE POSSIBLE MAINLY EARLY TO MID EVENING COINCIDENT WITH PEAK OR NEAR PEAK INSTABILITY WITH POTENTIAL FOR SB/ML CAPE VALUES TO BRIEFLY REACH UP TO AS HIGH AS 2000 J/KG FOR A SMALL PORTION OF OUR SOUTHWESTERN FCST AREA. SHORT RANGE GUIDANCE HAS ALSO TRENDED FASTER WITH FRONTAL TIMING THE PAST 24 HRS WHICH IS ALSO POTENTIALLY MORE FAVORABLE FOR A FEW STRONGER STORMS. THE MOST LIKELY TIME FRAME FOR CONVECTION IS FROM AROUND 23Z THIS EVENING THROUGH 05Z WEDNESDAY AS SUGGESTED BY 00Z 4KM NSSL WRF AND LATEST HRRR SIM Z GUIDANCE. HOWEVER IT IS NOTED THAT 0-6 KM BULK SHEAR IS WEAK AND MAINLY ONLY AROUND 20-25 KTS OFF LATEST SREF GUIDANCE... ALTHOUGH VERY BRIEFLY HIGHER VALUES ARE NOTED OVER OUR FAR NW FCST AREA. UPPER LEVEL SUPPORT FOR MORE ORGANIZED CONVECTIVE DEVELOPMENT PASSES BY WELL NORTH OF OUR FCST AREA. INSTABILITY IS FCST TO DIMINISH RATHER QUICKLY FROM MID TO LATE EVENING. SO THE OVERALL THREAT FOR SEVERE WX LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS IS RATHER LOW/MARGINAL. IT WILL BE BREEZY AND MUCH COOLER/DRIER WEDNESDAY WITH MAX TEMPS ONLY REACHING THE 70S. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM THE NW. HIGH PRESSURE WILL PRODUCE MOSTLY SUNNY SKIES THURSDAY WITH MAX TEMPS IN THE MID TO UPPER 70S. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 325 AM EDT TUE JUL 22 2014 THE MAIN CHALLENGE WITH THE LONG TERM FORECAST IS THE SHOWER AND TSTM POTENTIAL OVER THE COMING WEEKEND. GUIDANCE CONTINUES TO SUGGEST THAT THE PRIMARY CORRIDOR OF HEAVIER MCS ACTIVITY WILL BE SOUTHWEST/SOUTH OF MICHIGAN FRIDAY THROUGH SUNDAY... FROM ERN IOWA TO INDIANA. HOWEVER WE MAY STILL BE IMPACTED BY THE NRN PERIPHERY OF THESE CONVECTIVE COMPLEXES WITH PERIODS OF SHOWERS AND SCATTERED TSTMS...AIDED BY WEAK SHORTWAVES IN THE FAST W/NW FLOW ALOFT. A RATHER POTENT LOOKING SHORTWAVE IS PROGGED TO DROP DOWN FROM THE NORTHWEST SUNDAY NIGHT AND MONDAY... AND THE GFS/ECMWF ARE IN GOOD AGREEMENT ON THIS FEATURE. BEST POPS WILL EXIST DURING THIS PERIOD... FOLLOWED BY HIGH CONFIDENCE BELOW NORMAL TEMPERATURES BEHIND THIS SYSTEM FOR MOST OF NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 154 PM EDT TUE JUL 22 2014 VFR CONDITIONS IN PLACE AREA WIDE AT 18Z...WHICH WILL CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON. THE FOCUS IS ON THE EXTENT OF THUNDERSTORM DEVELOPMENT THIS EVENING. ESSENTIALLY EXPECTING SCATTERED THUNDERSTORMS TO DEVELOP AND SINK SOUTH THROUGH THE TAF SITES BETWEEN 22Z AND 06Z. BEST CHANCE FOR STORMS WILL BE AT KMKG...KGRR AND KAZO...WITH SLIGHTLY LESSER CHANCES INLAND. AT THIS POINT NOT CONFIDENT ENOUGH TO GO PREVAILING STORMS AT ANY GIVEN LOCATION SO USED VCTS WORDING THROUGH THE EVENING TIME FRAME. SOME STORMS MAY CONTAIN STRONG GUSTY WINDS IN EXCESS OF 35 KNOTS. OVERNIGHT...THE THREAT EXISTS FOR A MVFR CLOUD DECK TO SETTLE INTO THE TAF SITES ON NORTHERLY WINDS BEHIND A COLD FRONT. AT THIS POINT USED SCATTERED WORDING AT 1500FT TO CONVEY THE CHANCE OF THIS DECK DEVELOPING. A CHANCE AT SOME MVFR FOG FOR A TIME OVERNIGHT AS WELL WITH HIGH DEW POINT AIR IN PLACE. SKIES SHOULD GRADUALLY CLEAR/SCATTER OUT ON WEDNESDAY AS DRIER AIR WORKS IN FROM THE NORTH. SOME MODELS INDICATE A MVFR DECK HOLDING ON ACROSS MUCH OF THE AREA THOUGH THROUGH WEDNESDAY MORNING. && .MARINE... ISSUED AT 1145 AM EDT TUE JUL 22 2014 BEACH HAZARDS EVENT UNDERWAY AND GOING DOWN AS EXPECTED THUS FAR. THE LUDINGTON BUOY IS CURRENTLY SHOWING 4.6 FOOT WAVES AND THE WEBCAM THERE IS SHOWING SOME PRETTY BIG WAVES AT TIMES SMACKING THE SOUTH BREAKWALL. HOFFMASTER STATE PARK HAD 4 FOOTERS IN THEIR MORNING BEACH OB. IN LOOKING AT THE GRAND HAVEN WEBCAM FEELING OK WHERE WE HAVE THE BREAK IN THE SMALL CRAFT ADVISORY AND BEACH HAZARDS STATEMENT...WHICH IS JUST NORTH OF GRAND HAVEN. THE NORTHERN PORTIONS OF THE OTTAWA ZONE (GRAND HAVEN) WILL BE BORDERLINE THIS AFTERNOON WITH WAVES HOVERING AROUND THE 2-4 FOOT RANGE. HAVE OPTED TO JUMP INTO THE NORTH FLOW PORTION OF THE EVENT NOW AS WELL. HAVE EXTENDED THE NORTHERN HALF OF THE MARINE PRODUCTS SCA/BHS THROUGH TOMORROW EVENING. IN THE SOUTH HALF HAVE THEM STARTING UP AT 06Z TONIGHT AND LASTING THROUGH WEDNESDAY NIGHT AS THE FLOW COMES AROUND TO THE NORTH. IN TERMS OF BEACH IMPACT TODAY/S EVENT IN THE NORTH HALF OF THE MARINE AREA MAY BE THE HIGHER THREAT GIVEN THE WARM TEMPS...AND THEREFORE A LARGER BEACH POPULATION. TOMORROW/S WAVES WILL BE BIGGER BUT THE IMPACT MAY BE MITIGATED BY COOLER BEACH TEMPERATURES...RESULTING IN LESS FOLKS ON THE BEACH AND IN THE WATER. && .HYDROLOGY... ISSUED AT 334 PM EDT MON JUL 21 2014 WIDESPREAD SIGNIFICANT RAINFALL LOOKS UNLIKELY TUESDAY NIGHT AND WEDNESDAY. GENERALLY WE ARE EXPECTING A QUARTER TO THREE QUARTERS OF AN INCH OF RAINFALL WITH HIGHER AMOUNTS POSSIBLE IN HEAVIER THUNDERSTORMS. NOT ALL LOCATIONS ARE EXPECTED TO RECEIVE RAINFALL WITH THIS COLD FRONT. WITH A FAIRLY QUICK MOVING LINE OF CONVECTION ALONG THE FRONT...FLOODING IS A GREATLY MITIGATED THREAT. RIVERS HAVE BEEN FALLING STEADILY AND ASIDE FROM A TEMPORARY BUMP IN SOME LEVELS ON WEDNESDAY THIS TREND SHOULD CONTINUE FOR THE REST OF THE WEEK. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR MIZ056-064-071. BEACH HAZARDS STATEMENT THROUGH LATE WEDNESDAY NIGHT FOR MIZ037- 043-050. LM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR LMZ847>849. SMALL CRAFT ADVISORY FROM 2 AM WEDNESDAY TO 8 AM EDT THURSDAY FOR LMZ844>846. && $$ UPDATE...NJJ SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...MEADE AVIATION...DUKE HYDROLOGY...HOVING MARINE...DUKE
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
346 PM CDT Tue Jul 22 2014 .SHORT TERM: (Through Late Tonight) Issued at 330 PM CDT Tue Jul 22 2014 There is a considerable amount of uncertainty in the convective evolution and coverage tonight. Dew points in the 70s, strong heating and steep mid level lapse rates are currently contributing to SBCAPE of 3500-6000 j/kg across the northwest 2/3rds of the CWA with the highest values across central and north central MO. There also is a significant cap in place due to warm mid level temperatures. The big question is when and how much of the cap will be reduced as the front moves southward out of Iowa and southeast Nebraska into northern MO this evening. Model solutions including the convection allowing models are quite varied on QPF and implied coverage. Recent runs of the HRRR are quite stingy on coverage with isolated storms at best. I don`t have a great feel for what is going to occur, but the deterministic models suggest that height falls/cooling aloft should be sufficient to weaken the cap and allow for scattered development along front, mainly late this evening and especially overnight. I have attempted to follow this trend with the greatest coverage along/east of the MS river. The severe threat is conditional on development early enough this evening to realize the big CAPE, and the main threat would appear to be damaging winds given the warm air aloft. Glass .LONG TERM: (Wednesday through Next Tuesday) Issued at 330 PM CDT Tue Jul 22 2014 The cold front should lie roughly from south central IL to near St. Louis into southwest MO at 12z and exit the CWA by early afternoon. There will continue to be a threat of scattered showers and storms ahead of the advancing front. Temperatures should be cooler tomorrow with the main thrust of cooling and drying in the afternoon. Unseasonably deep upper troffing in the eastern U.S. will keep a large surface high dominating the area Wednesday night into Friday, with most of this period dominated by lower humidity and below average temperatures. Beginning late Thursday night and into Friday the threat of precipitation will return in association with elevated showers/thundestorms due to strong warm advection/moisture transport via a southwesterly LLJ ahead of the slowly retreating warm front and in association with impulses aloft dropping southeastward along the eastern periphery of the upper high. A cold front will then drop through the area Saturday afternoon-Sunday as a upper trof digs southeastward from the upper MS valley and into the Great Lakes bringing another threat of showers and thunderstorms. This upper wave will be part of large scale amplification of the upper air pattern across NOAM and will feature another deep trof over the eastern U.S. through the first part of next week and send out July with another period of below average temperatures. Glass && .AVIATION: (For the 18z TAFs through 18z Wednesday Afternoon) Issued at 131 PM CDT Tue Jul 22 2014 Upper level high retreating some to the west will allow fairly strong short wave to drop into into the eastern US bringing northwest flow back to the region. Associated surface cold front will move through late tonight and Wednesday morning. Forecast issue is when, where and if thunderstorms develop. Cooling aloft has to occur before the instability disappears. No model is convincing enough toexclusively follow. Have blended and followed previous forecast putting storm at UIN about 00z and gradually moving south, into STL at 06z. Models and soundings suggest some mvfr cielings wednesday am. Specifics for KSTL: Nothing out there has convinced me to change the previous forecast. CWSU concurs to keep the prevailing thunderstorms from 06 - 08z...with a couple of hours of mvfr ceilings Wednesday am. JPK && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
333 PM CDT Tue Jul 22 2014 .DISCUSSION... Issued at 333 PM CDT TUE JUL 22 2014 Mid to upper 90s prevailing across much of the region this afternoon as the warmest airmass of the season continues to grip the area. Latest 850-mb analysis from the SPC meso site showing the 28C temp contour directly over the fcst region this afternoon. This combined with steep low-level lapse rates and dewpoints largely in the lower to middle 70s has resulted in a very hot and oppressive day across the area. Current heat advisory for the entire fcst area needs no adjustments and is set to expire at 7 PM this evening. In addition to the heat...the other main concern remains focused on possible severe convection later this evening as main cold front now found over southwestern IA and eastern NE continues to slowly track south with time. For what its worth...high-res convection allowing models struggled mightily with this mornings convection across our northeastern zones...and very little guidance from these models appears to be in the offering for activity later this evening as well. Not surprisingly...overall confidence for tonight/s fcst is less than desired as some models show developing convection...while others such as the HRRR continue to backtrack towards a drier and drier fcst with each successive run. So here/s what we know so far... Sfc boundary set to arrive towards the IA/MO state line around 00z this evening. Out ahead of this feature...airmass remains capped with a significant amount of inhibition thanks that 700-mb temps ranging in the 12-14C range. Additionally...northerly 925-850-mb winds will provide little if any low-level convergence into the arriving frontal boundary as we continue into the evening hrs. Despite this...quick look at latest water vapor imagery does show an inbound shortwave trough now seen over south-central NE and north-central KS. This feature combined with very modest frontal convergence may be enough to get this going...however concerns for widespread severe remain marginal as of this writing. Latest SPC day 1 outlook has trimmed the SLGT risk mention further to the southeast...which is more in line with where convection may develop as front continues to drop south. That said...main severe threat with any activity that forms will likely be strong wind gusts as nearly dry adiabatic lapse rates will support favorable low-level and boundary layer mixing. High wet-bulb zero heights (>16 kft) will likely negate the threat for very large hail until later on when any lingering activity begins to go elevated with due to loss of daytime heating. Overall concerns for hail though remain the lowest of the two forms of severe outlined above however. In general...severe threat this evening looks to be isolated with the most likely areas to possibly see a rogue storm or two residing in our northeastern zones where better potential exists to break the cap thanks to slightly cooler temps aloft. If activity gets going...severe threat should transition south of the I-70 corridor as front continues to make progress through the area. As mentioned above through...a widespread severe event does not look to be in the offering this evening. Region should largely reside in a post frontal airmass tomorrow...with weak dry air advection allowing for cooler and less humid conditions. In fact...fcst models suggest dewpoints anywhere between 5-10 degrees cooler than today...which should be a welcomed relief following today/s oppressive conditions. High temps should round out in the middle to upper 80s. Large scale pattern shift expected from Thursday into Friday as southern Plains ridge retrograde west as northern stream energy traverses the northern Rockies/Plains. As this occurs...upper flow will become decidedly more northwesterly which will set the stage for unsettled conditions heading into the upcoming weekend. Closer to the surface...fcst models still paint a northward retreating warm front by late week as return flow reestablishes itself across the Great Plains in advance of leeside troughing along the Front Range. Several upper shortwaves embedded in northwest flow will allow for continued chances for showers and storms through at least Saturday...if not Sunday. As is the case with convection this time of year...hard to pin your hat on any one feature of interest as long range models to include both the ECMWF and GFS normally suffer from convective feedback issues to some degree. As a result...have maintained Chc pops through the weekend before high pressure arrives by early next week following the passage of a cold front on Sunday. Temps early next week look to fall below normal with highs possibly only reaching into the lower to middle 80s come Monday and Tuesday. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon) Issued at 1244 PM CDT TUE JUL 22 2014 Main concern heading into the fcst period remains focused on convection as weak cold front sinks south across the area. Latest model trends show the best potential east of all terminal sites but given the amount of uncertainty with the fcst...VCTS mention was maintained for all locations after 00z this evening. After 6z...any convection that does form should be south with weak northeast flow expected through the remainder of the overnight. Some potential for developing VSBY restrictions at STJ after 09z as front fails to scour out abundant low-level moisture. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...HEAT ADVISORY until 7 PM CDT this evening FOR KSZ025-057-060- 102>105. MO...HEAT ADVISORY until 7 PM CDT this evening FOR MOZ001>008-011>017- 020>025-028>033-037>040-043>046-053-054. && $$ DISCUSSION...32 AVIATION...32
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1024 AM MDT TUE JUL 22 2014 .UPDATE... THE MAIN UPDATE TO THE FORECAST THIS MORNING WAS TO SLOW DOWN THE PROGRESSION OF THE SHORTWAVE ACROSS THE FORECAST AREA...TO HOLD POPS IN ACROSS CENTRAL ZONES INTO THIS EVENING. THE BEST THREAT OF SEVERE WEATHER REMAINS OVER FAR SOUTHEAST MONTANA...BASICALLY FROM MILES CITY TO BROADUS AND EAST. LATEST HIGH RESOLUTION MODELS WANT TO KEEP THE MAIN SEVERE THREAT SOUTH INTO NORTH EAST WYOMING AND WESTERN SOUTH DAKOTA...BUT WANT TO CLIP OUR AREA WITH SOME STORMS. FORECAST THINKING IS THAT THESE MODELS ARE DISPLACING THE CONVECTION TOO FAR SOUTH THIS AFTERNOON...AND THAT THE GOING FORECAST REMAINS ON TRACK. FOR LOCATIONS FARTHER WEST...MODELS HAVE TRENDED SLOWER ON THE TIMING OF THE WEAK SHORTWAVE...AND THUS GIVE A BETTER CHANCE FOR AN ISOLATED STRONG STORM SOMEWHERE AROUND BILLINGS TO ROUNDUP AROUND 00Z TO 02Z AND TRACKING EASTWARD FROM THERE. THUS HAVE KEPT AN ISOLATED POP FOR CENTRAL ZONES THROUGH 03Z...TRENDING DOWN THEREAFTER. CHURCH && .SHORT TERM...VALID FOR TDY AND WED... WEAK SHORTWAVE ENERGY CONTINUES TO LIFT THRU A RELATIVELY MOIST AND UNSTABLE WSW FLOW ALOFT...AND PER LATEST RAP H5 ANALYSIS OUR HEIGHTS HAVE NOT YET BEGUN TO RISE. AT 2 AM THERE EXISTS A FEW LIGHT SHOWERS IN OUR CWA BUT THERE IS MORE UPSTREAM FROM SOUTH CENTRAL MT TO NORTHERN NV. HEIGHT RISES WILL COMMENCE LATER TODAY BUT IN THE MEANTIME AREAS OF PV INTERACTING WITH PWATS ON THE ORDER OF AN INCH SHOULD BE ENOUGH FOR ISOLD SHOWERS/TSTMS ACROSS MUCH OF THE AREA TODAY...AND CANNOT DISCOUNT SOME AFTN DEVELOPMENT AS MID LEVEL CAP WILL BE SLOW TO DEVELOP. FEEL THAT BY LATE AFTN OR EARLY EVENING THE PV WILL HAVE LIFTED NORTH AND MOST SHOWER ACTIVITY WILL END. TEMPS TODAY WILL BE CLOSE TO NORMAL WITH HIGHS IN THE MID 80S TO LOWER 90S. MOST IMPORTANT ISSUE TO ADDRESS TODAY EXISTS IN OUR EAST. SLOWER ONSET OF HEIGHT RISES WILL RESULT IN A SLIGHT RISK OF SEVERE STORMS FROM MILES CITY TO BROADUS EAST. ASCENT WILL COME IN THE FORM OF WEAK SHORTWAVE ENERGY ALONG A MID LEVEL WARM FRONT...AND A LOW LEVEL JET BY EVENING...WITH 1000+ J/KG OF CAPE AND 0-6KM BULK SHEAR ON THE ORDER OF 50 KTS. HAIL AND TO A LESSER DEGREE WIND WILL BE THE PRIMARY THREATS. LOW LEVEL SOUTHEASTERLY FLOW WILL KEEP THE HIGH PWAT AIR IN PLACE...SO HEAVY RAIN IS ALSO A POSSIBILITY. WILL HIGHLIGHT THE RISK FOR SEVERE WEATHER FOR THIS AFTN AND EARLY EVENING IN OUR EAST IN THE HWO/GRAPHIC. RIDGE WILL STRENGTHEN CONSIDERABLY TONIGHT AND WEDNESDAY WITH HEIGHTS EXPECTED TO CLIMB INTO THE 590S...CORRESPONDING WITH 700MB TEMPS TO NEAR +16C. THIS TONGUE OF VERY WARM MID LEVEL AIR AND LACK OF SIGNIFICANT FORCING WILL LIMIT OUR CONVECTIVE POTENTIAL CONSIDERABLY. INSTABILITY AND SHEAR PROFILES WILL BE IMPRESSIVE CLOSE TO THE DAKOTAS BORDER ON WEDNESDAY WITH STRONG SELY SFC FLOW DEVELOPING...SO IF A STORM IS ABLE TO DEVELOP IT WILL HAVE A VERY FAVORABLE ENVIRONMENT TO WORK WITH. WILL KEEP WITH ISOLD TSTMS MENTIONED IN OUR EAST. OUR CENTRAL AND WEST PARTS WILL BE MUCH DRIER WITH DEEPER MIXING. HAVE REMOVED MENTION OF TSTMS FOR MOST OF THIS AREA BUT KEPT ISOLD POPS IN OUR NW...CLOSER TO COOLER MID LEVEL TEMPS AND SHORTWAVE ENERGY IN WESTERN MT. COULD SEE SOME RIDGE RUNNER CONVECTION ACROSS NORTHERN MT WEDNESDAY NIGHT...BUT FEEL THIS WILL STAY NORTH OF OUR CWA. AS FOR TEMPERATURES...WEDNESDAY SHOULD BE THE WARMEST DAY YET OF 2014 FOR MOST OF OUR CWA. GIVEN THE 700MB TEMPS EXPECTED WE SHOULD SEE SOME AREAS REACH THE 100 DEGREE MARK...PERHAPS BILLINGS. HAVE RAISED TEMPS A FEW DEGREES BOTH WEDNESDAY AND WEDNESDAY NIGHT. THE RECORD HIGH OF 101F MAY BE APPROACHED AT LIVINGSTON... ESPECIALLY IF SW WINDS MIX OUT. RECORDS AT BILLINGS...MILES CITY AND SHERIDAN APPEAR TOO HIGH TO BE REACHED ON WEDNESDAY. OF COURSE...THE HOT WEATHER WILL CONTINUE TO WORK ON OUR DRYING FUELS...SETTING THE STAGE FOR A POTENTIALLY CRITICAL FIRE WEATHER DAY BY THURSDAY. JKL .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... THURSDAY STILL SHAPING UP FOR A POSSIBLE CRITICAL FIRE WEATHER DAY AS A DEEP TROUGH AND ASSOCIATED CLOSED LOW ALOFT CRASH THROUGH THE HIGH PRESSURE RIDGE THAT WILL BE OVER THE AREA. MODELS CONSISTENCY REMAINS VERY GOOD WITH CONFIDENCE CONTINUING TO INCREASE WITH THIS SYSTEM. 850 MB TEMPERATURES ARE EXPECTED TO RANGE FROM +28C TO 30C ACROSS THE FORECAST AREA. STRONG COMPRESSIONAL HEATING WILL TAKE PLACE AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH DURING THE LATE AFTERNOON HOURS. GFS SOUNDINGS CONTINUE TO INDICATE MIXING UP TO NEAR 500 MB. THIS WILL CAUSE TEMPERATURES OVER THE CENTRAL AND EASTERN ZONES TO CLIMB TO NEAR 100 DEGREES AT A FEW LOCATIONS. GUSTY WINDS DEVELOPING WITH THE FRONTAL PASSAGE AND THIS COMBINED WITH HUMIDITIES IN THE TEENS...WILL CREATE DANGEROUS FIRE WEATHER CONDITIONS. ZONAL FLOW SETTING UP FRIDAY FOR DRY AND COOLER WEATHER. DRY WEATHER AND NEAR TO SLIGHTLY ABOVE SEASONAL TEMPERATURES WILL CONTINUE THROUGH EARLY NEXT WEEK AS ANOTHER RIDGE OF HIGH PRESSURE BUILDS OVER THE NORTHERN PLAINS. RICHMOND && .AVIATION... ISOLATED TO WIDELY SCATTERED THUNDERSTORMS ARE EXPECTED OVER THE AREA TODAY AND THIS EVENING...MAINLY BETWEEN 21 AND 03 UTC. SOME RISK OF MVFR OR LOCAL/BRIEF IFR CONDITIONS EXISTS WITH ANY STORM THAT DOES DEVELOP...AND THERE IS A THREAT OF SEVERE THUNDERSTORM ACTIVITY WITH LARGE HAIL AND DAMAGING WINDS...MAINLY OVER SOUTH- EASTERN MT. SCHULTZ && .PRELIMINARY POINT TEMP/POPS... TDY WED THU FRI SAT SUN MON ------------------------------------------------------- BIL 090 063/098 066/098 057/085 057/085 058/087 059/090 2/T 21/U 11/N 11/U 11/U 11/U 11/U LVM 090 055/099 056/091 049/083 049/083 049/088 051/090 2/T 21/B 11/N 10/U 01/U 11/U 11/U HDN 092 059/100 062/101 057/086 056/086 057/088 058/091 2/T 21/U 11/G 11/U 11/U 11/U 11/U MLS 090 065/098 067/097 059/085 058/085 059/086 059/088 3/T 32/T 21/U 11/U 11/N 11/U 11/U 4BQ 090 061/098 064/100 058/085 058/085 058/085 058/088 3/T 32/T 21/U 11/U 11/U 11/U 11/U BHK 086 060/091 062/096 057/083 053/083 054/083 054/084 4/T 32/T 22/T 21/U 11/N 11/U 11/U SHR 090 057/098 059/098 053/084 053/084 053/085 054/087 2/T 21/U 11/U 11/U 11/U 11/U 11/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1241 PM CDT TUE JUL 22 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 501 AM CDT TUE JUL 22 2014 IN SHORT...THERE ARE TWO MAIN CONCERNS THROUGH THE NEXT 24 HOURS...ONE BEING ANOTHER DAY OF AT LEAST MARGINALLY-ADVISORY LEVEL HEAT INDEX VALUES ACROSS ROUGHLY THE SOUTHEAST 1/2 OF THE CWA...AND THE OTHER BEING WHETHER OR NOT A FEW ISOLATED STORM/POSSIBLY A BROKEN LINE OF STORMS CAN FLARE UP AND BECOME STRONG TO SEVERE GENERALLY NEAR/SOUTH OF THE STATE LINE LATE THIS AFTERNOON INTO THIS EVENING ALONG A SURFACE COLD FRONT. BOTH BEFORE AND AFTER THIS MAIN TIME FRAME OF CONCERN FOR POSSIBLE STRONG CONVECTION...AT LEAST ISOLATED CONVECTION CANNOT BE COMPLETELY RULED OUT. STARTING WITH THIS MORNING...SUPPOSE A FEW ROGUE SHOWERS/POSSIBLY A WEAK ELEVATED STORM SLIPPING INTO MAINLY NORTHERN PORTIONS OF THE CWA IS NOT OUT OF THE QUESTION...BUT CONFIDENCE IN THIS OCCURRING IS NOT HIGH ENOUGH TO INTRODUCE A FORMAL MENTION INTO A PREVIOUSLY-DRY FORECAST. THEN LATE TONIGHT...GENERALLY AFTER MIDNIGHT...CONFIDENCE IS VERY LOW ON WHAT WILL TRANSPIRE...AS SOME MODELS SHOW POTENTIALLY WIDESPREAD CONVECTION DEVELOPING OVER OR MOVING INTO PRIMARILY THE SOUTHWEST 1/2 OF THE CWA...WHILE OTHERS ARE BONE DRY. STARTING WITH THE HERE AND NOW AS OF 09Z/4 AM...DRY CONDITIONS ARE IN PLACE OVER THE CWA...WHILE AT LEAST A FEW COUNTIES OUTSIDE THE LOCAL AREA A SMATTERING OF WEAK ELEVATED THUNDERSTORMS ARE ROAMING PARTS OF WESTERN/NORTH CENTRAL NEB AND ALSO A SMALL PORTION OF WEST CENTRAL IA. THE ACTIVITY TO THE NORTH AND WEST APPEARS TO BE TIED MAINLY TO AN EAST-WEST ORIENTED ZONE OF FRONTOGENESIS IN THE 850-700MB LAYER. IN THE BIGGER PICTURE...WATER VAPOR SATELLITE IMAGERY ALONG WITH SHORT TERM MODEL DATA HIGHLIGHT THE EXPANSIVE HIGH/ANTICYCLONE EXTENDING EASTWARD INTO THE CENTRAL PLAINS FROM ITS CENTRAL CORE OVER THE NM/CO BORDER AREA. IN THE STRONGER FLOW TO THE THE NORTH...A VIGOROUS SHORTWAVE TROUGH WAS TRACKING EASTWARD ACROSS NORTHERN MN. ESSENTIALLY...THE LOCAL AREA LIES ALONG THE INTERFACE BETWEEN VERY WEAK MID/UPPER FLOW TO THE SOUTH AND SOMEWHAT STRONGER WESTERLY FLOW JUST TO THE NORTH ALONG THE FRINGES OF THE RIDGE AXIS. AT THE SURFACE...HIGH PRESSURE CENTERED OFF TO THE NORTH IN THE WAKE OF THE NORTHERN MN SHORTWAVE TROUGH HAS PUSHED A MODEST COLD FRONT SOUTHWARD INTO NEBRASKA OVERNIGHT...WITH ITS LEADING EDGE ALREADY WORKING INTO NORTHERN PORTIONS OF THE CWA AS EVIDENCED BY A SHIFT TO SOME NORTHERLY WIND COMPONENT...WHILE THE MAJORITY OF THE CWA HAS OBSERVED SOME VARIATION OF SOUTHERLY TO WESTERLY BREEZES IN THE 5-15 MPH RANGE OVERNIGHT. ALTHOUGH SOME DRIER LOW- 60S DEWPOINTS HAVE ADVECTED INTO WESTERN ZONES OVERNIGHT...MUCH OF THE EASTERN CWA CONTINUES HOLDING ONTO UPPER 60S-LOW 70S DEWPOINTS...MAKING FOR ANOTHER SEASONABLY WARM MORNING. LOW TEMPS WILL LIKELY EXHIBIT A RANGE FROM UPPER 60S/NEAR-70 WEST TO UPPER 70S-NEAR 80 EAST GIVEN THIS DEWPOINT GRADIENT. HEADING INTO THE DAYTIME HOURS...THE BIG PICTURE ALOFT INVOLVES A TRANSITION FROM MORE WESTERLY TO MORE NORTHERLY MID-UPPER LEVEL FLOW...IN RESPONSE TO THE EXPANSIVE RIDGE EDGING SLIGHTLY NORTH MORE OVER CO...AND THE NORTHEAST EDGE OF THIS RIDGE AXIS CLOSER TO THE LOCAL AREA BEING FLATTENED SOMEWHAT IN THE WAKE OF THE DEPARTING GREAT LAKES AREA TROUGH. MEANWHILE AT THE SURFACE...THE COLD FRONT WILL CONTINUE SINKING SOUTHWARD ACROSS THE AREA AS HIGH PRESSURE SHIFTS EASTWARD ACROSS THE DAKOTAS/MN AREA. ALTHOUGH THE SOUTHWARD PUSH OF THIS FRONT SHOULD EASE WITH TIME...MOST OF SOUTH CENTRAL NEBRASKA SHOULD OBSERVE PREVAILING NORTHEAST BREEZES UP TO AROUND 10-15 MPH THROUGH MOST OF THE DAY...WHILE LOCATIONS NEAR THE STALLING SOUTHERN EDGE OF THIS BOUNDARY NEAR AND SOUTH OF THE STATE LINE WILL OBSERVE A LIGHT/VARIABLE TO LIGHT SOUTHERLY BREEZE AS THE FRONT IS REINFORCED NEAR THE STATE LINE IN RESPONSE TO WEAK LOW PRESSURE CENTERED NEAR THE CO/KS BORDER. ALTHOUGH VERY WARM MID LEVEL TEMPS ON THE ORDER OF 13-15C AT 700MB SHOULD CONTINUE TO FIRMLY CAP LOW-LEVEL BASED CONVECTION THROUGH AT LEAST THE MAJORITY OF THE DAY...THERE ARE HINTS THAT A FEW ELEVATED SPRINKLES OR EVEN WEAK STORMS COULD PERCOLATE ABOVE THE CAP ALONG THE ELEVATED FRONTAL ZONE MAINLY THIS MORNING...AND WILL HAVE TO KEEP AN EYE OUT IN CASE SOME LOW POPS MIGHT NEED ADDED TO MAINLY THE NORTHERN CWA. OTHERWISE...THE MAIN FOCUS FOR POTENTIALLY MORE NOTEWORTHY AND LOWER-BASED CONVECTION SHOULD HOLD OFF UNTIL LATE AFTERNOON/EARLY EVENING NEARER THE SURFACE FRONT NEAR THE STATE LINE. ALTHOUGH THIS DEVELOPMENT IS CERTAINLY NO GUARANTEE GIVEN THE STRONG CAP...THE HOT/DEEPLY MIXED AIRMASS SOUTH OF THE FRONT MAY BE ENOUGH TO TRIGGER AT LEAST ISOLATED CONVECTION IN AN ENVIRONMENT CHARACTERIZED BY AROUND 2000-3000 J/KG MIXED LAYER CAPE BUT ONLY AROUND 25KT AT MOST OF DEEP LAYER SHEAR. SOME MODELS ARE MORE AGGRESSIVE WITH OTHERS IN THIS STORM DEVELOPMENT...AS FOR EXAMPLE THE 00Z 4KM NSSL WRF STRONGLY SUGGESTS IT WHILE THE LATEST 08Z RAP KEEPS STORMS AT BY LOCALLY THROUGH AT LEAST 02Z/9PM. AT ANY RATE...MAINTAINED THE SLIGHT POPS FOR LATE THIS AFTERNOON/THIS EVENING TO COVER AT LEAST THE POSSIBILITY OF THIS DEVELOPMENT ALONG THE EAST-WEST FRONTAL ZONE. DESPITE THE VERY CONDITIONAL NATURE OF THIS STORM DEVELOPMENT...THE STORM PREDICTION CENTER UPGRADED MUCH OF THE SOUTHERN CWA TO A SLIGHT RISK ON THE DAY 1 OUTLOOK...WITH THE MAIN THREATS LIKELY BEING STRONG OUTFLOW WINDS/DOWNBURST ACTIVITY...AND LESS-SO LARGE HAIL GIVEN SUCH WARM THERMAL PROFILES. SPEAKING OF THERMAL...TEMPERATURES AND DEWPOINTS HAVE BEEN A BIT OF A CHALLENGE FOR TODAY...AS MUCH OF THIS DEPENDS ON HOW FAST THE SLIGHTLY COOLER AIR CAN FILTER IN FROM THE NORTH TODAY...AND WHETHER DEWPOINTS AGAIN SPIKE BACK UP BEHIND THIS BOUNDARY AFTER FALLING OFF SOMEWHAT OVERNIGHT. TOOK A BEST STAB AT HIGHS USING A BLEND OF VARIOUS MODELS...YIELDING A RANGE FROM LOW 90S FAR NORTH...MID 90S CENTRAL AND GENERALLY 100-102 IN KS ZONES. WOULD NOT BE SURPRISED THOUGH TO SEE PARTS OF THE NORTH STAY A FEW DEGREES COOLER AND PARTS OF THE SOUTH RISE A FEW DEGREES HIGHER. THE NET RESULT FOR HEAT INDEX VALUES IS THAT AREAS MAINLY SOUTH OF A YORK-MINDEN LINE (INCLUDING KS) APPEAR MOST FAVORED TO REACH/SLIGHTLY EXCEED 105...AND THUS HAVE GONE WITH AN ADVISORY FOR THESE LOCATIONS ALTHOUGH DO NOT EXPECT AS MUCH OF THE HIGHER- THAN-EXPECTED COVERAGE OF 110+ HEAT INDEX READINGS THAT MATERIALIZED YESTERDAY IN EASTERN ZONES. OUTSIDE THE ADVISORY AREA TO THE NORTH AND WEST...IT WILL OBVIOUSLY STILL BE HOT...BUT LOOKING FOR SUB-ADVISORY LEVEL HEAT INDEX VALUES MORE INTO THE 95-102 RANGE. FOR THIS EVENING/TONIGHT...OBVIOUSLY HEAT INDEX/ADVISORY ISSUES WILL QUICKLY ABATE...LEAVING THE ULTIMATE QUESTION AS TO HOW MUCH IF ANY CONVECTION AND POSSIBLE STRONG-SEVERE STORM POTENTIAL REMAINS THROUGH THE NIGHT. AS FOR THE BIG PICTURE OF THE MID-UPPER LEVELS...FLOW WILL TURN EVEN MORE NORTHERLY AS THE STRONG HIGH PRESSURE CENTER PARKS ITSELF FIRMLY OVER CENTRAL CO...WHICH ACTUALLY ALLOWS MID LEVEL TEMPS TO COOL VERY SLIGHTLY OVER THE LOCAL AREA AS A LOW-AMPLITUDE SHORTWAVE TROUGH BRUSHES BY ALONG A TRACK FROM THE DAKOTAS INTO IA OVERNIGHT. AT THE SURFACE...GENERALLY EAST- NORTHEAST BREEZES AROUND 10 MPH WILL PREVAIL OVERNIGHT AS HIGH PRESSURE REMAINS CENTERED WELL OFF TO THE NORTHEAST OF THE LOCAL AREA. AS MENTIONED ABOVE...THERE IS TREMENDOUS UNCERTAINTY IN THE CONVECTIVE POTENTIAL OVERNIGHT. ONE SCENARIO IS THAT ONCE ANY EVENING ACTIVITY DIES OUT OR MOVES OUT OF THE AREA IN THE SOUTHERN CWA ALONG THE FRONTAL ZONE THAT NOTHING ELSE OCCURS THE REST OF THE NIGHT (PER THE ECMWF AND ALSO THE NSSL 4KM-WRF). MEANWHILE...OTHER MODELS SUCH AS THE NAM/GFS AND ALSO THE 4KM WRF-NMM SIMULATED REFLECTIVITY SHOW POTENTIALLY A FAIR AMOUNT OF CONVECTION AFFECTING MAINLY THE SOUTHWEST HALF OF THE CWA AFTER MIDNIGHT...POSSIBLY AS A RESULT OF A STORM COMPLEX RIDING SOUTHEASTWARD INTO THE AREA OUT OF THE BLACK HILLS/NORTHWEST NEB AREA. GIVEN THE TREMENDOUS UNCERTAINTY HERE...OPTED NOT TO GET CUTE WITH THE FORECAST AND JUST BLANKETED MUCH OF THE CENTRAL/SOUTHERN CWA WITH A GENERIC SLIGHT 20 PERCENT POP FOR THE LATER NIGHT HOURS. BESIDES CONVECTIVE POTENTIAL...SUPPOSE AT LEAST SOME LIGHT FOG CANNOT BE RULED OUT LATE TONIGHT MAINLY IN WESTERN ZONES...BUT CURRENT MODELS/GUIDANCE DO NOT SUPPORT VISIBILITY RESTRICTIONS BAD ENOUGH/WIDESPREAD ENOUGH FOR A FORMAL FORECAST INCLUSION AT THIS TIME. AS FOR LOW TEMPS...ONLY MADE MINOR TWEAKS AIMING FOR A RANGE FROM MID 60S NORTH TO AROUND 70 SOUTH. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 501 AM CDT TUE JUL 22 2014 TEMPS WILL BE UP AND DOWN DURING THE EXTENDED PERIODS AND ALTHOUGH THERE ARE HIT OR MISS CHCS FOR TSTMS...NOTHING IS LOOKING WIDESPREAD OR SIGNIFICANT AT THIS POINT IN TIME. FOLLOWING THE REALLY HOT TEMPERATURES MONDAY AND TUESDAY...READINGS WILL TREND COOLER ON WEDNESDAY AS THE UPPER RIDGE AXIS RETROGRADES ALONG THE HIGH PLAINS AND A TROUGH DEEPENS FM THE GREAT LAKES THRU THE OHIO VALLEY REGION. THE HOT AIR RETREATS AND COOLER AIR BACKS IN FROM THE EAST AND H85 TEMPS COOL SEVERAL DEGREES AND WE ARE LOOKING FOR AFTERNOON HIGHS TO RANGE FROM THE MID 80S IN OUR EASTERN ZONES TO AROUND 90F IN THE SW. A 1020MB SFC HIGH PRESSURE SYSTEM BUILDS SOUTH FROM THE UPPER MIDWEST WHICH WILL RESULT IN EASTERLY LLVL FLOW AND BRING THE COOLEST CONDITIONS TO OUR EASTERN ZONES. HAVE KEPT THE FORECAST DRY BUT THERE IS AN OUTSIDE CHC FOR REMNANT CONVECTION TO LINGER FOR A TIME WEDNESDAY MORNING IN THE VCNTY OF THE FRONTAL BOUNDARY IN OUR SOUTH. TEMPERATURES WILL BE ON THE INCREASE AGAIN THURSDAY FRIDAY AS THE UPPER RIDGE AXIS BUILDS EAST AGAIN AHEAD OF AN UPPER LOW TRANSLATING EAST FROM THE PACIFIC NORTHWEST. THE RIDGE AXIS DEAMPLIFIES BY THE END OF THE WEEK BUT THE AIRMASS REMAINS QUITE WARM THRU FRIDAY AND HIGH TEMPERATURES SHOULD AGAIN AVERAGE IN THE 90S. A PROGRESSING MID LEVEL SHORTWAVE TROUGH AND WAA AHEAD OF THE SYSTEM WILL BRING THE POTENTIAL FOR TSTMS THURSDAY AND THURSDAY NIGHT. THEN...A COLD FRONT ASSOCIATED WITH THE NORTHERN CONUS SYSTEM PUSHES SOUTHEAST DURING THE DAY ON FRIDAY BUT CHCS FOR STORMS LOOK NEGLIGIBLE WITH THE BOUNDARY. OVER THE WEEKEND AND EARLY NEXT WEEK THE UPPER RIDGE RETROGRADES AND BUILDS OVER THE ROCKIES WHILE AN UPPER TROUGH DEEPENS FM THE GREAT LAKES THROUGH THE OHIO VALLEY. COOLER AIR WILL RETURN IN THE MORE MERIDIONAL FLOW AND TEMPERATURES WILL DROP BACK CLOSER TO SEASONAL READINGS OR BELOW. CANNOT COMPLETELY RULE OUT PCPN CHCS IN THE OUTER PERIODS AS TEMPERATURES COOL ALOFT AND BOUNDARIES MOVE THRU. THIS BEING SAID NOTHING SAID THERE IS NO REAL CONCLUSIVE PERIOD FOR CONVECTION EITHER AND HAVE ONLY CARRIED LOW POPS IN OUR SOUTH FOR SUNDAY NIGHT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1232 PM CDT TUE JUL 22 2014 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS SHOULD BE EAST TO NORTHEAST. && .GID WATCHES/WARNINGS/ADVISORIES... NE...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR NEZ064-074>077- 083>087. KS...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ005>007-017>019. && $$ SHORT TERM...PFANNKUCH LONG TERM...FAY AVIATION...JCB
AREA FORECAST DISCUSSION
NWS PORTLAND OR
202 PM PDT TUE JUL 22 2014 .SYNOPSIS...A LOW PRESSURE SYSTEM WILL BRING AN INCREASING THREAT OF RAIN SHOWERS AND EVEN A FEW THUNDERSTORMS TO THE AREA TONIGHT AND ESPECIALLY WEDNESDAY. AFTER A CLOUDY AND WET START TO WEDNESDAY...EXPECT A MIX OF SUNSHINE AND SHOWERS IN THE AFTERNOON. DRIER AND MORE SUMMER-LIKE TEMPERATURES ARE EXPECTED TO ARRIVE LATE THURSDAY AND FRIDAY...BEFORE TEMPERATURES PUSH 90F LATE IN THE WEEKEND. && .SHORT TERM...THIS EVENING...A VORT MAX...APPARENT IN WATER VAPOR SATELLITE IMAGERY...NEAR THE BAY AREA WILL LIFT NORTHEASTWARD THIS AFTERNOON AND EVENING INTO SOUTH CENTRAL OREGON. VISIBLE SATELLITE IMAGERY SHOWS FAIRLY EXTENSIVE CLOUD COVER OVER THE EASTERN HALF OF THE FORECAST AREA WITH A FEW BREAKS CREEPING INTO THE CASCADES. A DESTABILIZING LOWER ATMOSPHERE AND LIFT AHEAD OF THE AFOREMENTIONED VORT MAX SHOULD ALLOW THUNDERSTORMS TO DEVELOP ACROSS SOUTH CENTRAL OREGON THIS AFTERNOON. IN FACT...CONVECTION IS BEGINNING TO FIRE EAST OF THE CENTRAL OREGON CASCADES NEAR BEND. WITH ADDITIONAL HEATING THIS AFTERNOON...EXPECT SOME OF THIS CONVECTION TO BEGIN DEVELOPING JUST TO THE WEST OF THE CREST...BUT THERE STILL REMAINS UNCERTAINTY IN HOW MUCH...IF ANY...WILL DEVELOP. THE LATEST RAP GUIDANCE SUGGESTS A FEW THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON OVER THE LANE AND LINN COUNTY CASCADES...BUT IF THE CURRENT MID LEVEL CLOUDS LINGER TOO MUCH LONGER THIS AFTERNOON...SURFACE BASED CONVECTION WILL LIKELY STAY ENTIRELY EAST OF OUR FORECAST AREA. THE LATEST HRRR SUPPORTS THE LATTER IDEA. IT SHOULD BE NOTED THAT IF ANY STORMS DO BREAK THE CAP ON OUR SIDE OF THE CREST...40-45 KT OF 0-6KM BULK SHEAR AND CAPE VALUES BETWEEN 500- 750 J/KG WILL AID STORM ORGANIZATION. FREQUENT LIGHTNING...AND POSSIBLY MARGINALLY SEVERE HAIL AND DAMAGING WINDS WOULD BE THE PRIMARY THREATS OF CONCERN IF STORMS WERE TO MATERIALIZE. AGAIN...THE MOST LIKELY AREA TO EXPERIENCE SUCH STORMS IS PRIMARILY NEAR THE CASCADE CREST...SOUTH OF MOUNT JEFFERSON. FOR TONIGHT...THE LARGE SHORTWAVE TROUGH CURRENTLY NEAR 135W...DUE WEST OF OREGON...WILL ELONGATE FURTHER TONIGHT...TURNING THE MID LEVEL FLOW OVER NORTHWEST OREGON SLIGHTLY MORE SOUTHERLY. THE NAM BRINGS A PIECE OF THE VORT MAX/PV ANOMALY NEAR 130W AND 35N ACROSS THE AREA LATE TONIGHT. WITH NEGATIVE THETAE LAPSE RATES BETWEEN 700-500MB ADVECTING INTO THE REGION...AND REGION BEING IN THE RIGHT ENTRANCE/LEFT EXIT REGION OF TWO UPPER LEVEL JETS...WE MAY SEE SHOWERS AND EVEN A FEW ELEVATED THUNDERSTORMS SPREAD NORTHWARD ACROSS WESTERN OREGON LATE TONIGHT. HOWEVER...CONFIDENCE IS LOW SO THE THUNDER MENTION WAS LIMITED TO A SLIGHT CHANCE. THE LATEST HRRR KEEPS THE BULK OF THE ACTIVITY RIGHT ALONG THE CASCADE CREST AND POINTS EAST...BUT GIVEN THE PATTERN WILL KEEP THE MENTION IN THE FORECAST. THE PREVIOUSLY MENTIONED ELONGATING SHORTWAVE TROUGH NEAR 135W WILL BEGIN TO PUSH EAST-NORTHEASTWARD ACROSS THE AREA WEDNESDAY. STRONG MID LEVEL FRONTOGENESIS SHOULD LEAD TO A FAIRLY ORGANIZED NORTH-SOUTH ORIENTED BAND OF RAIN MOVING EASTWARD INTO THE OREGON COAST WEDNESDAY MORNING. SOME MODEST MID LEVEL INSTABILITY COUPLED WITH THE DYNAMICS MAY LEAD TO A FEW LIGHTNING STRIKES ALONG THE FRONT...PARTICULARLY OVER THE COASTAL WATERS AND NEAR THE COAST LATE TONIGHT INTO WEDNESDAY MORNING. THE BAND OF RAIN SHOULD PUSH EASTWARD ACROSS THE AREA WEDNESDAY MORNING. SUBSIDENCE BEHIND THE MID LEVEL FRONT MAY LEAD TO A RATHER ABRUPT END TO THE RAIN/CLOUDS EARLY TO MID WEDNESDAY AFTERNOON. HOWEVER...ANY CLEARING WILL NOT LAST LONG...AS THE LOWER ATMOSPHERE SHOULD DESTABILIZE QUICKLY...AND A SPRING-LIKE PATTERN OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL LIKELY ENSUE LATE WEDNESDAY AFTERNOON AND EARLY EVENING. THE GREATEST INSTABILITY WILL BE OVER THE NORTHERN HALF OF THE FORECAST AREA SO THE MENTION OF THUNDER WAS INCREASED TO CHANCE WORDING. WITH A SURFACE LOW PRESSURE LINGERING JUST OFF THE SOUTHWEST WASHINGTON COAST WEDNESDAY THERE MAY BE A TENDENCY FOR SURFACE WINDS IN THE WILLAMETTE VALLEY AND ALONG THE LOWER COLUMBIA RIVER TO HAVE A BIT MORE OF A S TO SSE COMPONENT THAN OTHERWISE EXPECTED. COMBINED WITH WSW WINDS OF 25 KT AT 900MB AND 40KT AT 500MB...A RAPIDLY STRENGTHENING UPDRAFT COULD ROTATE BRIEFLY. HOWEVER...CONFIDENCE IS VERY LOW IN THIS ACTUALLY OCCURRING SOMEWHERE WITHIN THE CWA...BUT IT WILL STILL BE WORTH MONITORING. THE MORE EXPECTED HAZARDS... GUSTY WINDS AND SMALL HAIL WERE ADDED TO THE THUNDER WORDING IN THE GRIDS. ON THE FIRE FRONT...MOST LOCATIONS ACROSS THE FORECAST AREA SHOULD SEE WETTING RAINS OF A QUARTER TO HALF INCH WITH A FEW LOCATIONS LIKELY PUSHING AN INCH OF RAIN...PARTICULARLY ACROSS SOUTHWEST WASHINGTON. IT SHOULD BE NOTED WETTING RAINS ARE LESS LIKELY TOWARDS LANE COUNTY...BUT CERTAINLY APPEAR POSSIBLE WEDNESDAY. EXPECT A DRYING TREND WEDNESDAY NIGHT INTO THURSDAY BEFORE MORE SEASONABLE WEATHER RETURNS FRIDAY. /NEUMAN .LONG TERM...HIGH PRESSURE WILL BUILD WESTWARD ACROSS THE CONUS AMPLIFYING AN UPPER-LEVEL RIDGE THAT WILL SET UP OVER THE NORTHWESTERN U.S. THIS WILL INCREASE TEMPERATURES BACK TO ABOVE NORMAL OVER THE WEEKEND. THERE IS A POSSIBLE DISTURBANCE THAT COULD MOVE THROUGH AS EARLY AS SUNDAY NIGHT...BUT MUCH UNCERTAINTY EXISTS IN THE TIMING OF THIS SYSTEM AND LOCATION. -MCCOY && .AVIATION...GENERALLY VFR THIS AFTERNOON WITH MOSTLY CLEAR SKIES N OF A K6S2-KKLS LINE. S OF THIS LINE IS ALSO VFR BUT WITH SCT-BKN CLOUD DECK GENERALLY ABOVE 6000 FT. THE EXCEPTIONS ARE A FEW LOCAL MVFR POCKETS ASSOCIATED WITH SHOWERS...AND ALONG THE IMMEDIATE COAST WHERE LIFR MARINE STRATUS HAS SURGED N FROM K6S2 TO JUST N OF KONP. EXPECT TRENDS TO PERSIST UNTIL TONIGHT WHEN RAIN ASSOCIATED WITH APPROACHING LOW PRESSURE SYSTEM MOVES INTO THE REGION STARTING AROUND 10Z. EXPECT CIGS TO LOWER AFT 12Z...WITH MVFR CIGS AROUND 2000 FT POSSIBLE. LOCAL POCKETS OF IFR POSSIBLE IN HEAVIER RAIN...AND ALONG THE COAST. HIGHER TERRAIN AND MOUNTAINS OBSCURED TONIGHT THROUGH MID MORNING WED. KPDX AND APPROACHES...EXPECT VFR TO CONTINUE THROUGH THIS EVENING WITH SCATTERED CLOUDS AROUND 3000 FT AND AN OVERCAST DECK ABOVE 5000 FT. SOME LIGHT RAIN POSSIBLE...BUT EXPECT RAIN TO INCREASE AFT 12Z WITH CIGS LOWERING TO LOW VFR TO HIGHER MVFR. CANNOT RULE OUT SOME THUNDER DEVELOPMENT OVER ERN APPROACHES THIS EVENING...OR OVER MUCH OF THE OPS AREA TOMORROW AFTERNOON...BUT NOT ENOUGH CONFIDENCE TO INCLUDE IN TAF FOR NOW. CULLEN && .MARINE...RELATIVELY QUIET CONDITIONS OVER THE WATERS CONTINUE TONIGHT AS THE SURFACE GRADIENT REMAINS WEAK IN BETWEEN SYSTEMS...KEEPING WINDS 15 KT OR LESS. SEAS REMAIN 3-4 FT TODAY WITH A CONTINUED SMALL W-NW SWELL. A LOW PRES SYSTEM WILL PASS THROUGH THE WATERS LATE TONIGHT INTO WED. MODELS HAVE TRENDED TO INDICATE THE POTENTIAL FOR MARGINAL SMALL CRAFT WINDS TOMORROW AFTERNOON...BOTH S WINDS ALONG THE COASTAL INNER WATERS AND ALSO OVER MUCH OF THE WATERS AS THE SURFACE LOW PUSHES ACROSS. CONFIDENCE REMAINS SOMEWHAT LOW AT THIS TIME HOWEVER SO WILL LET NEXT SHIFT EVALUATE NEXT MODEL CYCLE BEFORE POTENTIALLY RAISING THE SMALL CRAFT ADVISORY. LATER THIS WEEK...HIGH PRES REDEVELOPS OVER NE PAC AS THERMAL LOW PRES BUILDS OVER N CALIFORNIA. THIS WILL BRING A RETURN TO GUSTY N WINDS AND STEEP WIND DRIVEN SEAS...PARTICULARLY IN THE LATE AFTERNOON AND EVENING HOURS...FRI THROUGH THE WEEKEND. CULLEN && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WA...NONE. PZ...NONE. && $$ 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. COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1225 PM CDT TUE JUL 22 2014 .UPDATE... 18Z TAF DISCUSSION. && .AVIATION... AS NOTED IN MORNING UPDATE...CONVECTION HAS STRUGGLED TO DEVELOP TODAY ON THE PLATEAU LIKELY DUE TO SOME SUBSIDENCE NOTED ON WATER VAPOR IMAGERY. NEVERTHELESS...WILL INCLUDE VCSH MENTION AT CSV FOR POTENTIAL SHOWER DEVELOPMENT. OTHERWISE...VFR CONDITIONS ARE EXPECTED THE REST OF TODAY WITH LIGHT SOUTH TO SOUTHEAST WINDS AT ALL AIRPORTS. MVFR VIS DUE TO PATCHY FOG EXPECTED OVERNIGHT AT CKV/CSV. SHAMBURGER && .PREV DISCUSSION... /ISSUED 930 AM CDT TUE JUL 22 2014/ UPDATE... FORECAST LOOKS TO BE ON TRACK AND NO CHANGES WERE MADE. TEMPERATURES ALREADY WARMING THROUGH THE 80S PER LATEST OBS WITH DEWPOINTS IN THE UPPER 60S AND 70S...AND A HOT AND HUMID DAY IS ON TAP WITH AFTERNOON HEAT INDICES TOPPING OUT WELL INTO THE 90S UP TO NEAR 100 DEGREES. POPS MAY BE A TAD ON THE HIGH SIDE OVER SOUTH AND EAST ZONES BASED ON LATEST HRRR RUNS BUT WILL LEAVE AS IS FOR NOW. SHAMBURGER PREV DISCUSSION... /ISSUED 606 AM CDT TUE JUL 22 2014/ AVIATION UPDATE...FOR 12Z TAF PACKAGE... SIMILAR TO YESTERDAY...BEST CHANCE FOR TSRA IMPACTS WILL BE AT KCSV. INCLUDED VCTS AGAIN AS LOCATION OF STORM DEVELOPMENT IS UNCLEAR. CLOUD COVER SHOULD PERSIST OVER THE EASTERN HALF OF THE MID STATE BUT SHOULD STAY AT VFR THROUGHOUT THE PERIOD. ONLY OBSTRUCTIONS WOULD BE LIGHT TO MODERATE FOG TOWARD THE MORNING HOURS TOMORROW. PREV DISCUSSION... /ISSUED 328 AM CDT TUE JUL 22 2014/ DISCUSSION... UPPER LOW CONTINUING TO SPIN ACROSS THE DEEP SOUTH NEAR THE FL PANHANDLE THIS MORNING. PERSISTENT UPPER DIVERGENCE HAS HELPED TO PROLONG THE NOCTURNAL SHOWER ACTIVITY TO THE EAST OF THE LOW. ACROSS MIDDLE TN...BROKEN CLOUDINESS STILL PERSISTS ACROSS OUR SOUTHEASTERN COUNTIES WITH PCLDY SKIES ELSEWHERE. OVER THE NEXT FEW DAYS...UPPER TROUGHING TO EXPAND ACROSS THE GREAT LAKES REGION WITH UPPER LEVEL HIGH EXPANSION ACROSS THE SOUTHWESTERN U.S.. THE PATTERN OVER THE MID STATE WILL THEN MORPH INTO MORE OF A ROBUST NORTHWESTERLY FLOW ALOFT. IN FACT...A COLD FRONT WILL SLIDE ACROSS THE AREA WEDNESDAY NIGHT AND BRING A CHANCE OF SHOWERS AND TSTMS. THE BOUNDARY LOOKS AS THOUGH IT WILL MAKE IT JUST SOUTH OF TN BY THURSDAY. SO FOR THE FCST...LOW CONVECTION CHANCES FOR TODAY AS THE WEAKENING UPPER LOW CONTINUES TO EXERT SOME INFLUENCE ACROSS THE AREA. POPS WILL INCREASE WED AFTERNOON AND NIGHT. FOR THE NEAR TERM TEMPS...QUITE WARM TODAY AND AGAIN ON WEDNESDAY AS HEIGHTS INCREASE...COMPLIMENTS OF THE STRENGTHENING UPPER RIDGE TO OUR WEST. WE`LL COOL THINGS OFF BY THURSDAY BEHIND THE AFOREMENTIONED FRONTAL PASSAGE. IN THE EXT FCST...NORTHWESTERLY FLOW TO CONTINUE THROUGH THE EXTENDED PERIOD. ANOTHER FRONTAL BOUNDARY WILL IMPACT THE AREA ON SUNDAY WITH WHAT LOOKS LIKE A DESCENT SHOT OF RAIN. FRONTAL BOUNDARY WILL PUSH SOUTH OF THE MID STATE ON MONDAY WITH A DEEPENING UPPER TROUGH INDICATED ACROSS THE EASTERN U.S.. FOR THE EXT TEMPS...WARM AGAIN THIS WEEKEND IN ADVANCE OF THE NEXT COLD FRONT. SLIGHTLY BELOW NORMAL TEMPS WILL RETURN BY EARLY NEXT WEEK. DEWPOINTS ARE LOOKING VERY PLEASANT FOR LATE JULY. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 55
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
330 PM CDT TUE JUL 22 2014 .SHORT TERM... (Tonight and Wednesday) A strong subtropical ridge remains anchored over the southern Rockies this afternoon with 500 mb heights approaching 600 dam at the center of the anticyclone. Isolated thunderstorms have developed over portions of West TX, basically between Lubbock and San Angelo, moving southwest toward the Permian Basin. A few cells have developed within the CWA from near Sweetwater to Sterling City. Surface temperatures approaching 100 degrees have effectively removed the cap, tapping into sufficient instability to support thunderstorms. SPC mesoanalysis from the RAP indicates MLCAPE values on the order of 1500 J/kg. With weak winds aloft, ordinary cells will be the convective mode with a classic microburst profile in place per point soundings. Isolated thunderstorms were carried through 10 PM generally west of a line from Sweetwater to Mertzon. Otherwise, we`ll see light winds overnight with temperatures falling into the low to mid 70s by sunrise. Any thunderstorms lingering into the evening hours should quickly dissipate by sunset. Temperatures will again warm to near 100 degrees Wednesday afternoon with light winds from a generally easterly direction. Johnson .LONG TERM... (Wednesday Night through Tuesday) An upper ridge centered over northern New Mexico and the northern Panhandle and extending north into south-central Canada will continue to minimize our precipitation chances while giving us above normal temperatures through the coming weekend. A developing upper trough over the eastern half of then nation will displace the upper ridge to the west through the by the beginning of next week. As the upper ridge moves west there will be some relief from the unseasonal heat as afternoon highs drop from the upper 90s and triple digits down to the mid and upper 90s beginning next Monday. Models are indicating a frontal boundary moving as far south as the Red River Valley on Monday may provide a focus for some convective activity. At this time the best chances of rainfall would be north of the forecast area with a slight chance of some activity moving south into at least our northern CWA. The models are also showing a TUTT low mowing west over deep south Texas which should keep any associated rainfall south of our area. In any event, given the inherent uncertainty in the models this far out, will keep the forecast dry at this time. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 74 99 74 100 74 / 0 5 5 5 5 San Angelo 73 100 71 101 72 / 5 5 5 10 5 Junction 71 98 71 98 72 / 0 5 5 10 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
355 PM CDT TUE JUL 22 2014 .TONIGHT...FORECAST CONFIDENCE - MEDIUM. HEAT INDEX VALUES ENDED UP EXCEEDING 100 FROM MADISON AND WEST LATE THIS AFTERNOON AFTER THE LOW CLOUDS CLEARED AWAY. MADISON REACHED A HIGH OF 90 OR GREATER FOR THE FIRST TIME THIS YEAR. SPC TRIMMED THE SLIGHT RISK A LITTLE FURTHER SOUTHEAST AGAIN WITH THE 3 PM UPDATE. MESOSCALE MODELS CONTINUE TO KEEP THE AREA CAPPED /NO CONVECTION/ UNTIL THE FRONT GETS INTO FAR SOUTHEAST WI OR EVEN NORTHEAST IL LATE THIS AFTERNOON BETWEEN 22Z AND 00Z. SPC MESOANALYSIS RAP IS SHOWING ERODING CIN ALONG THE FRONT IN CENTRAL WI...SO I WILL CONTINUE THE SLIGHT CHANCE ALONG THE FRONT AS IT MOVES SOUTHEAST THROUGH THE MKX FORECAST AREA. WE CANNOT RULE STORM DEVELOPMENT GIVEN THE HIGH DEWPOINTS...SURFACE FRONT...VERY HIGH CAPE OVER 4000 J/KG AND SIGNS OF SLIGHT UPSTREAM COOLING AT 700- 850MB. THE INHIBITING FACTORS FOR CONVECTION ARE: THE CAP. THE WESTERLY WINDS JUST AHEAD OF THE SURFACE AND 850MB FRONTS ARE LIMITING THE LOW LEVEL CONVERGENCE. WE WILL HAVE TO SIT AND WAIT TO SEE IF THE CAP BREAKS AS THE SURFACE FRONT REACHES SOUTHEAST WI. THERE IS LIMITED BULK SHEAR OF 25 TO 30 KNOTS. ISOLATED SEVERE HAIL AND WINDS WILL BE POSSIBLE. PRECIPITABLE WATER VALUES AROUND 2 WILL LEAD TO VERY HEAVY RAIN WITH ANY THUNDERSTORMS. URBAN FLOODING WILL BE POSSIBLE. PRECIP CHANCES EXIT WITH FRONT LATE THIS EVENING WITH COOLER AND DRIER AIR MOVING IN. TEMPERATURES DOWN INTO THE LOWER 60S AND DEW POINTS IN THE MID TO UPPER 50S BY WEDNESDAY MORNING. WEDNESDAY...FORECAST CONFIDENCE HIGH. HIGH PRESSURE...DRIER AND AND COOLER TEMPERATURES WILL SETTLE INTO THE REGION. LOOK FOR DIURNAL CUMULUS CLOUDS TO DEVELOP BY LATE MORNING AND LINGER THROUGH EARLY AFTERNOON DUE TO STEEP LOW LEVEL LAPSE RATES. STEADY NORTH WINDS WILL GRADUALLY DIMINISH DURING THE AFTERNOON. WINDS WILL BE HIGHEST NEAR THE LAKE. .WEDNESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE - HIGH. THE QUIET AND LESS HUMID WEATHER WILL CONTINUE THROUGH THURSDAY AS A HIGH PRESSURE RIDGE AND DRIER DEWPOINTS HOLD SWAY ACROSS THE WESTERN GTLAKES. EXPECT PATCHY FOG LATER WED NIGHT DUE TO LIGHT BOUNDARY LAYER WINDS AND LINGERING DEWPOINTS IN THE LOW TO MID 50S. EXPECT SOME LOCATIONS TO DIP DOWN INTO THE 40S LATE WED NIGHT. THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE - LOW. CONSIDERABLE DIFFERENCES BETWEEN SHORT TERM GUIDANCE IN HANDLING OF LOW TO MID LEVEL FORCING DURING THIS PERIOD. GFS ONLY GUIDANCE IN BRINGING CONVECTION ASSOCIATED WITH WARM FRONT SOUTHEAST ACROSS SOUTHERN WI ON FRIDAY. MEANWHILE...CANADIAN MAINTAINS WMFNT ORIENTATION FARTHER SOUTH ACROSS MO/SRN IL. LATEST ECMWF A BLEND BETWEEN THE TWO WHICH CLIPS PORTIONS OF SW INTO SOUTH CENTRAL WI WITH CONVECTION GENERATED BY MOISTURE AND WARM AIR ADVECTION RETURN. WL LEAN TOWARD MORE SOUTHERN SOLUTION AND KEEP LOWER POPS IN THE WEST AND SOUTH DURING THIS PERIOD AS LEANING TOWARD DRIER SOLUTION WITH BETTER CHANCE FOR CONVECTION FARTHER WEST AND SOUTH. ECMWF AND NAM SHOW STRONGER W-NW FLOW STEERING FLOW ACROSS SRN WI WHILE GFS STRONGER SW. GFS REMAINS OUTLIER AT THIS POINT. TOO MANY DESCREPANCIES SO CONFIDENCE REMAINS LOW. .FRIDAY NIGHT THROUGH TUESDAY - FORECAST CONFIDENCE - LOW TRENDING TOWARD MEDIUM. LIKE NCEP WPC BLENDED...PREFER ENSEMBLE OF MEDIUM RANGE GUIDANCE FOR THIS FORECAST PERIOD. MOST OF THE MEDIUM RANGE GUIDANCE IS SHOWING SOMEWHAT BETTER AGREEMENT THAN 24 HOURS AGO...AND ARE CONVERGING ON A SOMEWHAT SIMILAR SOLUTION. WEAKENING MID-LEVEL RIDGE OVER NORTHERN PLAINS CONTINUES TO WEAKEN AND FLATTEN EARLY THIS FORECAST PERIOD AS LOW PRESSURE MOVES ACROSS SOUTHERN CANADA. GFS CONTINUES TO PHASE THIS SYSTEM WITH EASTERN CANADA LONG WAVE TROUGH A BIT QUICKER THAN CANADIAN/ECMWF SOLUTIONS. GFS BRINGS SHORT WAVE ACROSS WI SAT NIGHT INTO SUN...WHILE OTHER SOLUTIONS ARE SLOWER...LATER SUNDAY INTO SUNDAY NIGHT. HENCE WL NEED TO KEEP CHANCE POPS GOING OVER THE WEEKEND AS UPPER LEVEL TROUGH MOVES THROUGH REGION. BY MONDAY...NORTHWEST WINDS IN THE LOW TO MID LEVELS WILL HAVE USHERED COOLER AND DRIER AIR INTO SRN WI...HOWEVER WEAK RIPPLES IN FAST NORTHERLY FLOW MAY GENERATE -SHRA. && .AVIATION/00Z TAFS/... A COLD FRONT MOVING SOUTHEAST THROUGH SOUTHERN WI WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS ALONG IT LATE THIS AFTERNOON. THE CHANCE WILL INCREASE AS THE FRONT GETS INTO FAR SOUTHEAST WISCONSIN AROUND 6 PM...ESPECIALLY KENOSHA AND THEN SOUTHWARD INTO NORTHEAST IL. ANY THUNDERSTORMS WILL BRING MVFR CIGS/VSBYS IF THEY DEVELOP. EXPECT VERY HEAVY RAIN. WINDS WILL BECOME NORTHWEST BEHIND THE FRONT... THEN NORTH TO NORTHEAST OVERNIGHT. EXPECT A PERIOD OF BROKEN VFR CUMULUS CLOUDS WED MIDDAY ON STEADY NORTHERLY WINDS. && .MARINE...SMALL CRAFT ADVISORY IN EFFECT UNTIL 9 PM. WINDS AND WAVES WILL RISE ON WEDNESDAY IN THE WAKE OF THE COLD FRONT. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED. && BEACHES...MILWAUKEE...RACINE AND KENOSHA COUNTIES WILL BE IN A HIGH RISK OF SWIMMING HAZARDS LATER TONIGHT AND WEDNESDAY. SHEBOYGAN AND OZAUKEE COUNTY BEACHES WILL BE IN A MODERATE RISK OF SWIMMING HAZARDS TONIGHT AND HIGH RISK WEDNESDAY. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVY LMZ643>646 UNTIL 02Z/23. && $$ TONIGHT/WEDNESDAY AND AVIATION/MARINE/BEACHES...MRC WEDNESDAY NIGHT THROUGH TUESDAY...MBK
CONTINUES WITH THE MODEL. SEE THE PREVIOUS FORECAST DISCUSSION FOR
MORE DETAILS ABOUT THE AFTERNOON CONVECTION.
PREV DISCUSSION... /ISSUED 506 AM CDT TUE JUL 22 2014/ TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM. RADAR RETURNS OVER WEST CENTRAL AND SW WISCONSIN ON LEADING EDGE OF 850 MB WARM ADVECTION...IN REGION OF DECENT CONVERGENCE. HOWEVER NO GROUND TRUTH AS PRECIP IS DEVELOPING ABOVE DRY...WARM LAYER BETWEEN 750MB AND 650 MB RESULTING IN VIRGA ONLY MAKING IT DOWN TO AROUND 5K FT ABOVE THE GROUND. THIS CAPPING INVERSION WILL BE PROBLEMATIC DURING THE DAY AS WARM ADVECTION CONTINUES TO STRENGTHEN THE CAP AHEAD OF THE COLD FRONT. CONSENSUS SFC-BASED CAPE INCREASES TO BETWEEN 2500 AND 3000 J/KG BUT CIN REMAINS IN THE 150 TO 200 J/KG RANGE. NAM DOES SHOW AN ERODING CAP TOWARDS THE 22Z-00Z TIME FRAME...BUT IT HAS DEW POINTS APPROACHING 80F AND SB-CAPE APPROACHING 5000 J/KG. FOLLOWING LOWER CONSENSUS TEMPS/DEW POINTS TRENDS TOWARD THE MORE CAPPED SOLUTION. BULK SHEAR OF 25 TO 30 KTS ACCOMPANIES MEAGER 500 MB HEIGHT FALLS/MID-LEVEL COOLING AS SRN EDGE OF SHORT WAVE TROUGH PASSES THROUGH LEADS TO THE POTENTIAL FOR SOME ISOLATED/SCATTERED SEVERE STORMS IF CAP IS BROKEN AS FRONT PASSES THROUGH. WILL LIMIT POPS TO MID-HIGH CHANCE CATEGORY LATE THIS AFTERNOON AND EVENING. FORECAST TEMPERATURES IN THE UPPER 80S TO LOW 90S WITH LOW-MID 70S DEW POINTS KEEP APPARENT TEMPERATURES BELOW HEAT ADVISORY HEADLINES EXCEPT FOR A SMALL PORTION OF THE WESTERN CWA AROUND LONE ROCK. NOT CONFIDENT IN HIGHS REACHING THE FORECAST IF CLOUDS REMAIN THICKER THAN EXPECTED AND TOO SMALL AN AREA FOR A HEADLINE. WILL CONTINUE ISSUANCE OF SPS HIGHLIGHTING THE NEAR-ADVISORY WARMTH. PRECIP CHANCES EXIT WITH FRONT LATE THIS EVENING WITH COOLER AND DRIER AIR MOVING IN. TEMPERATURES DOWN INTO THE LOWER 60S AND DEW POINTS IN THE MID TO UPPER 50S BY WEDNESDAY MORNING. WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...HIGH HIGH PRESSURE IS EXPECTED TO BRING DRY WEATHER AND AMPLE SUNSHINE WEDNESDAY AND THURSDAY. IT SHOULD BE A COUPLE OF VERY PLEASANT DAYS WITH HIGHS IN THE 70S MOST PLACES. THREW IN SOME LOW POPS SOUTHWEST THURSDAY NIGHT...AS THE HIGH HEADS EAST AND WARM ADVECTION MAY KICK OFF A FEW STORMS. FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM A SERIES OF SHORTWAVES ARE EXPECTED TO BRING SHOWER/STORM CHANCES TO SOUTHERN WISCONSIN AT TIMES FRIDAY THROUGH THE WEEKEND. MODELS STILL HAVE SOME DETAILS TO WORK OUT...SO LEFT CHANCE POPS THROUGH THE WEEKEND. LOOKS LIKE TEMPS WILL BE NEAR NORMAL THROUGH SUNDAY. IT LOOKS LIKE THERE WILL BE LESS AVAILABLE MOISTURE EARLY NEXT WEEK...BUT STILL WENT WITH SOME LOW POPS MONDAY AS MODELS ARE ADVERTISING A WEAK WAVE. TEMPS SHOULD BE A COUPLE DEGREES COOLER AS WELL. AVIATION/12Z TAFS/... EXPECT VFR CONDITIONS THROUGH THE FORECAST. CURRENT BAND OF HIGH- BASED PRECIPITATION ON RADAR OVER SOUTHERN WISCONSIN STRUGGLING TO REACH THE GROUND...THOUGH A FEW SPOTS HAVE REPORTED VERY LIGHT RAIN/SPRINKLES WITH ONLY TRACE AMOUNTS. BEST CHANCE FOR SHOWERS AND STORMS WILL BE ALONG COLD FRONT...BUT WILL HAVE TO BREAK THROUGH WARM MID-LEVEL CAP. WILL KEEP VICINITY THUNDERSTORMS IN TAFS FOR LATE AFTERNOON/EVENING...WHICH WILL BRING MVFR CIGS/VSBYS IF/WHEN THEY DEVELOP. GUSTY SOUTH TO SOUTHWEST WINDS AHEAD OF FRONT WILL LOWER AND TURN NORTH TO NORTHEAST BEHIND FRONT TONIGHT. MARINE...HAVE LEFT SMALL CRAFT ADVISORY HOURS FROM PREVIOUS FORECAST. EXPECT SOUTH TO SOUTHWEST WIND GUSTS TO REACH CRITERIA MID-MORNING AND CONTINUE INTO LATE THIS AFTERNOON BEFORE LOWERING AS COLD FRONT/SURFACE TROUGH MOVES THROUGH. WAVES WILL BE SLOWER TO LOWER...SO 9 PM END TIME IS LOOKING GOOD. WINDS AND WAVES WILL RISE ON WEDNESDAY AS HIGH PRESSURE BUILDS IN BEACHES...SOUTH TO SOUTHWEST WINDS WILL GUST TO BETWEEN 20 AND 25 KNOTS TODAY. WHILE SOUTHERN ZONES WILL ONLY SEE WAVES BUILD TO 1 TO 3 FEET AT MOST ALONG THE BEACHES...THE NORTHERN 2 ZONES MAY SEE 3 TO 5 FOOT WAVES...ESPECIALLY AT SOUTH-FACING BEACHES. THIS PLACES SHEBOYGAN AND OZAUKEE COUNTY BEACHES IN A MODERATE RISK OF SWIMMING HAZARDS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR LMZ643>646. && $$ UPDATE...MRC TODAY/TONIGHT AND AVIATION/MARINE...REM WEDNESDAY THROUGH MONDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1216 PM CDT TUE JUL 22 2014 .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 253 AM CDT TUE JUL 22 2014 ORGANIZED LINE OF CONVECTION WORKING EAST ACROSS MINNESOTA AND NORTHERN WISCONSIN THIS MORNING. LOCAL AND REGIONAL RADARS SHOWING SOME ECHOES DEVELOPING SOUTH OF THE LINE ON THE EDGE OF THE MOISTURE TRANSPORT AXIS. LOOKING AT THE MESO SCALE MODELS THIS MORNING...THE HRRR AND RAP ARE PRETTY MUCH USELESS AS THEY TURN THE SYSTEM MORE NORTHEAST AND DISSIPATE IT WAY TOO QUICKLY. THE 22.00Z HI-RES ARW AND NMM LOOK MUCH MORE REASONABLE WITH THE CONVECTIVE COMPLEX AND CONTINUE MOVING IT EAST TAKING IT JUST NORTH OF THE FORECAST AREA. LOOKING AT THE 22.00Z NAM BUFKIT SOUNDING FOR LADYSMITH...THIS MAKES SENSE AS THE CAP HOLDS IN PLACE THROUGH THE REMAINDER OF THE NIGHT. AS FOR THE DEVELOPING ECHOES OVER THE FORECAST AREA...THESE ARE JUST STARTING TO GET SOME SPRINKLES TO THE GROUND. THE HI-RES NMM SHOWS THE ECHOES CONTINUING THROUGH THE NIGHT UNTIL THE MOISTURE TRANSPORT STARTS TO BEND MORE OFF TO THE EAST BUT DOES NOT REALLY SHOW THEM EXPANDING AND KEEPS THEM SCATTERED. WITH THE MAIN CONVECTIVE COMPLEX EXPECTED TO MOVE BY TO THE NORTH...HAVE LOWERED THE RAIN CHANCES ACROSS THE NORTH DOWN TO ABOUT 40 PERCENT FOR THIS MORNING. TO HANDLE THE LIGHT ECHOES...WILL SHOW ABOUT A 20 PERCENT AS FAR SOUTH AS I90 UNLESS OBSERVATIONS START INDICATING THAT THIS ACTIVITY IS REACHING THE GROUND. FOR THE REMAINDER OF TODAY...THE MAIN SHORT WAVE TROUGH WILL PASS ACROSS LAKE SUPERIOR INTO ONTARIO. A SECONDARY SHORT WAVE TROUGH WILL DROP ACROSS THE REGION DURING THE AFTERNOON AS THE FLOW BECOMES NORTHWEST ALOFT. IT APPEARS THAT THIS SECONDARY SHORT WAVE TROUGH WILL ONLY PRODUCE SOME WEAK PV ADVECTION IN THE 500-300 MB LAYER AS IT MOVES ACROSS. HOWEVER...THE FORCING FROM THIS WAVE DOES NOT LOOK LIKE IT WILL BE ABLE TO INTERACT WITH THE FRONT UNTIL IT HAS MOVED PAST THE AREA. THE NAM BUFKIT SOUNDING FOR BLUE RIVER INDICATES THE CAP WILL HOLD IN PLACE UNTIL LATE THIS AFTERNOON WHILE THE 22.00Z GFS HOLDS IT INTO THE EVENING. WITH THE CAP REMAINING IN PLACE...ALL THE MODELS SUGGEST FURTHER DEVELOPMENT ALONG THE FRONT DOES NOT TAKE PLACE UNTIL THIS EVENING AND SOUTH OF THE FORECAST AREA. JUST IN CASE THE NAM IS CORRECT AND THE CAP DISSIPATES A LITTLE SOONER...HAVE OPTED TO HOLD ONTO A 20 TO 30 PERCENT RAIN CHANCE ACROSS THE SOUTHEAST SECTIONS FOR THE LATE AFTERNOON INTO THE EARLY EVENING. LOOKS LIKE TEMPERATURES WILL HAVE A GOOD OPPORTUNITY TO WARM THIS AFTERNOON AHEAD OF THE FRONT. HIGH TEMPERATURES IN THE UPPER 80S TO LOWER 90S OVER THE SOUTHEAST HALF OF THE AREA ARE A PRETTY GOOD BET. DEW POINTS ARE EXPECTED TO AGAIN GET INTO THE MIDDLE 70S AHEAD OF THE FRONT...WHICH WILL PUSH THE HEAT INDEX IN THE ADVISORY RANGE ACROSS THE SOUTHERN SECTIONS AND WILL BE ISSUING A HEAT ADVISORY TO HANDLE THIS. THE REST OF THE PERIOD LOOKS TO BE QUIET WITH COOLER AND DRIER CONDITIONS AS A LARGE AREA OF HIGH PRESSURE MOVES ACROSS THE REGION FROM CANADA TOWARD THE OHIO RIVER VALLEY. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 253 AM CDT TUE JUL 22 2014 SOME DIFFERENCES BETWEEN THE MODELS ON HOW FAST THE NEXT SYSTEM MOVES INTO THE REGION. THE UPPER LEVEL RIDGE THAT BUILDS OVER THE WESTERN PART OF THE COUNTRY OVER THE FIRST HALF OF THE WEEK...GETS FLATTENED AS AN UPPER LEVEL LOW MOVES ONSHORE FROM THE PACIFIC AND ACROSS SOUTHERN CANADA. THE DIFFERENCES IN THE MODELS COMES FROM HOW FAST SHORT WAVE TROUGHS WILL CUT THROUGH THE FLOW BETWEEN THE UPPER LEVEL LOW AND THE RIDGE. IT LOOKS LIKE THE 22.00Z ECMWF CONTINUES TO BE FASTER THAN THE GFS AND 22.00Z GEM ON BRINGING THE FIRST SHORT WAVE THROUGH. HOWEVER...ALL OF THEM SHOW THE SAME GENERAL PATTERN WITH THE WAVE AND A SURFACE LOW TRACKING FROM THE DAKOTAS SOUTHEAST TOWARD THE OHIO RIVER VALLEY. WITH THE GFS AND GEM BEING A LITTLE SLOWER...WILL INDICATE THE HIGHEST RAIN CHANCES FRIDAY INTO FRIDAY NIGHT. THE NEXT SHORT WAVE TROUGH AND SURFACE LOW STILL LOOK TO COME THROUGH OVER THE WEEKEND AND TRACK FARTHER NORTHEAST THAN THE FRIDAY SYSTEM. THIS SYSTEM WILL BRING SOME RAIN CHANCES TO THE ENTIRE AREA FOR SUNDAY WITH THE BETTER CHANCES OVER CENTRAL WISCONSIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1216 PM CDT TUE JUL 22 2014 DRIER AIR AND NORTHWEST WINDS WERE SPREADING SOUTHEAST ACROSS THE AREA AT MID DAY...WITH WINDS BECOMING NORTHWEST IN THE 10KG G15-20KT RANGE. DEW POINTS WERE DROPPING FROM THE LOW-MID 70S TO THE MID 60S. HOWEVER A BAND OF 2K-3K FT STRATO-CU WAS LOCATED ACROSS NORTHWEST WI TO SOUTHWEST MN...BEHIND THE COLD FRONT BRINGING IN THE DRIER AIR. THIS BAND OF CLOUDS THINNING THE PAST COUPLE HOURS BUT STILL APPEARS THERE WILL BE SOME BKN025 CIGS AT KRST THRU 20Z. WITH CONTINUED THINNING APPEARS LOWER CLOUDS AT KLSE WILL REMAIN SCT AS THE BAND MOVES ACROSS IN THE 19-21Z PERIOD. GOOD VFR CONDITIONS AND DECREASING NORTHWEST TO NORTH WINDS THEN EXPECTED FOR LATER THIS AFTERNOON THRU TONIGHT AND FOR WED AS DRIER CANADIAN HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST. LIGHT NORTH WINDS TONIGHT SHOULD KEEP ANY RADIATIONAL VALLEY BR/FG IN THE 09-13Z TIME-FRAME TO A MINIMUM AND LEFT THIS OUT OF THE KLSE TAF. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR WIZ054-055-061. MN...NONE. IA...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR IAZ029-030. && $$ SHORT TERM...04 LONG TERM....04 AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
359 PM MDT TUE JUL 22 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 306 PM MDT TUE JUL 22 2014 FAR LESS COVERAGE OF CU COMPARED TO THE SAME TIME MONDAY WHICH SURELY IS INDICATIVE OF THE WARMER TEMPS ALOFT. SFC MOISTURE HAS INCREASED BEHIND LAST NIGHTS WEAK BOUNDARY...WITH THE 50F ISODROSOTHERM BANKED UP TO THE FRONT RANGE. AM BEGINNING TO SEE SOME WEAK CONVECTIVE DEVELOPMENT MAINLY IN THE VICINITY OF THE NRN LARAMIE RANGE...AND SOME NR THE SNOWY AND SOUTHERN LARAMIE RANGE TOO. MESOANALYSIS SHOWS A PRETTY HEALTHY CAPPING INVERSION REMAINS IN PLACE...ESPECIALLY OVR THE ERN PLAINS. EXPECT THIS CAP CONTINUE TO ERODE THRU THE AFTERNOON. THE STRONGER CAP WILL MEAN DEEP CONVECTION WILL BE A BIT LATER IN DEVELOPING...WHICH ACCORDING TO THE HRRR WILL BE BETWEEN 3-6 PM. LARAMIE COUNTY AND THE SOUTHERN END OF GOSHEN/PLATTE COUNTIES LOOK TO SEE THE BEST CHANCE INITIALLY. WILL SEE ADDL DEVELOPMENT OVR NORTHEAST WYOMING DIVE SOUTHEAST INTO FAR EAST CENTRAL WYOMING AND THE NRN NEBRASKA PANHANDLE THIS EVENING. IT IS THIS AREA WHERE SEVERE POTENTIAL WILL BE GREATEST WITH SBCAPES OF AROUND 2000 J/KG ONCE THE CAP BREAKS. THIS CONVECTION WILL DISSIPATE BY AROUND SUNSET. ATTENTION THEN TURNS TO A BETTER CHANCE FOR SEVERE THUNDERSTORM DEVELOPMENT WEDNESDAY AFTERNOON. THERMODYNAMIC PROFILES WILL BE MORE CONDUCIVE FOR THUNDERSTORM DEVELOPMENT WEDNESDAY AS MID-LEVEL HEIGHTS/TEMPS FALL WITH THE APPROACH OF SHORTWAVE ENERGY. THIS WILL MEAN LESS OF A CAP AND A LIKELY EARLIER START TO CONVECTIVE INITIATION...WHICH SHOULD OCCUR OVR THE SNOWY/SIERRA MADRE RANGES BY MIDDAY. PROGD SBCAPES OVR THE ERN PLAINS CLIMB ABOVE 3000 J/KG WEDNESDAY AFTERNOON AND WHEN COMBINED WITH DEEP LAYER SHEAR OF 25-30 KNOTS SHOULD BE SUFFICIENT FOR SOME CONVECTIVE ACTIVITY BECOMING SEVERE. STORMS WILL SPREAD ONTO THE SOUTHEAST WYOMING PLAINS WEDNESDAY AFTERNOON AND INTO THE WESTERN NEBRASKA PANHANDLE DURING THE EVENING. AREAS OVR THE SOUTHERN PANHANDLE MAY BE INFLUENCED A BIT TOO MUCH BY THE CAP...WHICH MAY LIMIT CONVECTIVE STRENGTH THERE. CONVECTION AGAIN WILL WANE WITH LOSS OF INSOLATION. FIRST SHORTWAVE PUSHES THRU THURSDAY MORNING WITH A TRAILING SHORTWAVE POISED TO MOVE THRU THURSDAY AFTERNOON. INSTABILITY AXIS WILL BE FLATTENED AND WEAKENED BY THE INITIAL SHORTWAVE. SO EXPECT A LESS FAVORABLE ENVIRONMENT FOR SEVERE THUNDERSTORM POTENTIAL. EVEN SO...WEAK INSTABILITY PARAMETERS WILL BE SUFFICIENT FOR AT LEAST SOME ISOLATED CONVECTIVE POTENTIAL. THURSDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH HIGH TEMPERATURES THAT WILL AGAIN REACH 90S AT MOST LOCATION AND LOW TRIPLE DIGITS OVER LOWER ELEVATIONS OF THE WESTERN NEBRASKA PANHANDLE. .LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 306 PM MDT TUE JUL 22 2014 HIGH PRESSURE CONTINUES TO REMAIN DOMINANT OVER THE FOUR CORNERS REGION BUT BEGINS TO ERODE TO THE SOUTH OVER THE WKND. FAIRLY POTENT TROUGH OF LOW PRESSURE MOVES ACROSS THE SOUTHERN CANADIAN PROVINCES AND BRINGS A SERIES OF ASSOCIATED COOL FRONTS ACROSS THE AREA (THE STRONGEST FRONT WILL BE SAT EVENING). UPSLOPE FLOW LOOKS TO DEVELOP BY FRI AFTN AS DEW POINTS APPROACH THE MID 50S OVER THE PANHANDLE. COULD SEE SOME ISOLATED SHOWERS AND THUNDERSTORMS DURING THIS TIMEFRAME BOTH FRI AND SAT SO HAVE KEPT SOME SLIGHT POPS IN THE FCST. THE ECMWF IS MORE MOIST THAN THE GFS ATTM AND GENERATES A BETTER COVERAGE OF STORMS EACH AFTN AND EVENING. TEMPS BEGIN TO COOL TO MORE SEASONABLE LEVELS IN THE LOW TO MID 80S FOR SUNDAY...BUT THE RIDGE BEGINS TO BUILD BACK INTO THE AREA AND TEMPS SHOULD WARM TO THE MID 80S BY MONDAY FOR SOUTHEASTERN WY AND NEAR 90 FOR AREAS OF THE PANHANDLE AS 700 MB TEMPS WARM TO NEAR 15C. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING) ISSUED AT 1143 AM MDT TUE JUL 22 2014 VFR CONDITIONS THROUGH THE TAF PERIOD. WINDS WILL TURN TO THE SOUTHEAST THIS AFTN BUT GUSTS SHOULD GENERALLY REMAIN BELOW 20 KTS. WHILE MUCH OF THE AREA WILL NOT SEE STORMS THIS AFTN AND EVENING...ISOLATED TSTMS WILL BE POSSIBLE ACROSS THE NORTHERN NEBRASKA PANHANDLE...MAINLY FROM 01-05Z. GUSTY WINDS AND BRIEF HEAVY RAIN WILL BE THE MAIN THREATS FROM THESE STORMS. && .FIRE WEATHER... ISSUED AT 306 PM MDT TUE JUL 22 2014 WINDS HAVE HELD BELOW CRITICAL THRESHOLDS THUS FAR TODAY...DESPITE RELATIVE HUMIDITIES THAT HAVE DROPPED BELOW 15 PERCENT. SOME ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER LARAMIE COUNTY LATE THIS AFTERNOON AND OVER EXTREME EAST CENTRAL WYOMING AND THE NORTHERN NEBRASKA PANHANDLE THIS EVENING. WEDNESDAY WILL PROVIDE A BETTER OPPORTUNITY FOR AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE DISTRICT...SOME OF WHICH COULD POTENTIALLY BECOME SEVERE IN LOCATIONS EAST OF THE LARAMIE RANGE. DRIER AND BREEZIER CONDITIONS WILL EXIST OVER WESTERN CARBON AND CONVERSE COUNTIES ON WEDNESDAY. CONDITIONS WILL LIKELY BECOME NEAR CRITICAL IN THESE AREAS WEDNESDAY. THURSDAY LOOKS POTENTIALLY MORE CRITICAL OVER WESTERN CARBON AND CONVERSE COUNTIES AND WILL LIKELY NEED TO ISSUE A HEADLINE IN TIME. AFTERNOON AND EVENING SHOWER AND THUNDERSTORM CHANCES WILL CONTINUE THURSDAY AND FRIDAY MAINLY FOR AREAS EAST OF THE LARAMIE RANGE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...HAHN LONG TERM...FINCH AVIATION...FINCH FIRE WEATHER...HAHN