Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/23/14


AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
305 AM PDT MON APR 21 2014 .SYNOPSIS... FAIR SKIES AND WARM TEMPERATURES WILL CONTINUE THROUGH TODAY AS WEAK HIGH PRESSURE PREVAILS. A FRONTAL SYSTEM ON TUESDAY WILL BRING SIGNIFICANT COOLING AND BLUSTERY CONDITIONS TO THE REGION AND A CHANCE OF LIGHT PRECIPITATION OVER THE NORTHERN PART OF THE FORECAST AREA. TEMPERATURES WILL CONTINUE COOLER THAN AVERAGE ON WEDNESDAY BEFORE REBOUNDING A FEW DEGREES AT THE END OF THE WEEK. && .DISCUSSION... ONE MORE DAY OF ABOVE-NORMAL TEMPERATURES WITH CENTRAL CALIFORNIA UNDER A RIDGE...THEN A SHARP CHANGE IN THE WEATHER BEGINS TONIGHT AND CONTINUES THROUGH WEDNESDAY. THE 00Z MODELS ARE IN GOOD AGREEMENT WITH SLIGHT WARMING TODAY AHEAD OF THE APPROACHING COLD FRONT...WITH 850-MB TEMPERATURES OVER THE CENTRAL SAN JOAQUIN VALLEY WARMING ABOUT 0.5-1.0 C. HIGH TEMPERATURES ACROSS THE CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY SUNDAY WERE MAINLY IN THE LOWER TO MID 80S...AND SHOULD BE IN THE MID 80S TO AROUND 90 TODAY. THE UPPER-LEVEL LOW WAS LOCATED NEAR 51N/142W THIS MORNING...WEST OF THE NORTHERN TIP OF VANCOUVER ISLAND. A NARROW FRONTAL BAND EXTENDED FROM THE WASHINGTON/OREGON COAST SOUTHWEST TO EAST OF HAWAII...WHILE THE UPPER-LEVEL TROUGH AXIS WAS ALONG 140W. PRECIPITATION AHEAD OF THE FRONT WILL REACH THE CENTRAL SIERRA NEVADA THIS EVENING AND SPREAD SOUTH INTO THE FRESNO COUNTY MOUNTAINS OVERNIGHT AS WELL AS INTO MERCED AND MADERA COUNTIES IN THE CENTRAL VALLEY. RAIN AND SNOW SHOWERS ARE FORECAST TO MOVE INTO THE TULARE COUNTY MOUNTAINS TUESDAY...BUT RAIN IS EXPECTED TO REMAIN NORTH OF FRESNO ON THE SAN JOAQUIN VALLEY FLOOR. THE MODELS ARE IN AGREEMENT WITH 850-MB TEMPERATURES OVER THE CENTRAL SAN JOAQUIN VALLEY PLUNGING FROM AROUND 15.5 C THIS AFTERNOON TO AROUND 4 C TUESDAY AFTERNOON. SNOW LEVELS ARE FORECAST TO FALL TO AROUND 5500 FEET BY WEDNESDAY MORNING DOWN THE LENGTH OF THE SOUTHERN SIERRA NEVADA AND THE TEHACHAPI MOUNTAINS. HOWEVER... THIS APPEARS TO BE A RELATIVELY MOISTURE-STARVED SYSTEM...AND QPF FOR THE MOUNTAINS IS EXPECTED TO BE LESS THAN A TENTH OF AN INCH... AND ONLY A FEW HUNDREDTHS ON THE SAN JOAQUIN VALLEY FLOOR. THE MAIN IMPACT OF THIS STORM WILL BE GUSTY WINDS OVER THE WEST SIDE OF THE SAN JOAQUIN VALLEY...OVER THE SOUTHERN SIERRA NEVADA CREST AND ACROSS THE MOUNTAINS AND DESERTS OF KERN COUNTY AS THE COLD FRONT PUSHES THROUGH. DEPENDING ON HOW MUCH RAIN FALLS AHEAD OF THE FRONT...BLOWING DUST ON THE WEST SIDE OF THE SAN JOAQUIN VALLEY COULD BE A CONCERN. BLOWING DUST IS MORE LIKELY IN THE KERN COUNTY DESERT AND THE INDIAN WELLS VALLEY TUESDAY AND TUESDAY EVENING. AT THIS TIME...WINDS ARE FORECAST TO ONLY BRIEFLY REACH ADVISORY LEVELS IN THE KERN COUNTY MOUNTAINS AND DESERT AREAS TUESDAY...AND REMAIN MAINLY BELOW ADVISORY LEVELS ON THE WEST SIDE OF THE SAN JOAQUIN VALLEY. BASED ON HOW THE 12Z RUNS OF THE HIGHER-RESOLUTION NAM-12 AND HRRR HANDLE THE WINDS...ADVISORIES MAY BE NEEDED BUT WILL LET THE DAY CREW EVALUATE THINGS. ANOTHER RIDGE IS FORECAST TO BUILD INTO CALIFORNIA FOR NEXT THURSDAY...BRINGING ANOTHER ROUND OF DRY AND WARMER WEATHER. HIGH TEMPERATURES NEXT THURSDAY ARE FORECAST TO RECOVER TO NEAR NORMAL. CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY HIGHS NEXT FRIDAY ARE FORECAST TO WARM INTO THE UPPER 70S TO LOWER 80S...A FEW DEGREES ABOVE THE NORMAL FOR LATE APRIL. THE GLOBAL-COMPOSITE WATER VAPOR LOOP SHOWS THE NEXT UPPER-LEVEL LOW STRADDLING THE INTERNATIONAL DATE LINE AT 50N. BOTH THE GFS AND THE ECMWF FORECAST THIS LOW TO IMPACT THE WFO HANFORD WARNING/FORECAST AREA FRIDAY INTO NEXT WEEKEND. THE GFS IS STRONGER WITH THIS SYSTEM THAN THE ECMWF...BUT AT THIS TIME IT LOOKS LIKE MAINLY A MOUNTAIN PRECIPITATION EVENT. && .AVIATION... MOUNTAIN OBSCURATION AND LOCAL MVFR CONDITIONS IN SHOWERS OVER THE SOUTHERN SIERRA AROUND YOSEMITE AFTER 06Z TUESDAY. OTHERWISE...VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS. && .AIR QUALITY ISSUES... NONE. && .CERTAINTY... THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH. THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS HIGH. THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD. CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL INFORMATION AND/OR TO PROVIDE FEEDBACK. && .CLIMATE... RECORDS SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR KFAT 04-21 98:2009 50:1900 64:2012 36:1968 KFAT 04-22 96:2012 57:2010 66:2012 33:1968 KFAT 04-23 100:1910 56:1961 62:2012 39:1958 KBFL 04-21 99:2009 57:2010 64:2009 33:1904 KBFL 04-22 98:2012 58:2010 67:2012 34:1920 KBFL 04-23 100:1910 59:1960 62:2012 33:1904 && .HNX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ PUBLIC...SANGER AVN/FW...DCH SYNOPSIS...SANGER WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
328 PM MDT MON APR 21 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 328 PM MDT MON APR 21 2014 ...INCREASING WINDS FOR TUESDAY... UPPER RIDGE AXIS HAS BEEN SHIFTING EASTWARD ACROSS CO THIS AFTERNOON WITH WEAK PV ANOMALY EXITING THE SOUTHEAST PLAINS. SFC DEW POINTS HAVE DROPPED OFF INTO THE 20S ACROSS MOST OF THE AREA...WITH SOME LOWER TO MID 30S ACROSS THE SOUTHERN PORTIONS OF THE SOUTHEAST PLAINS AND SOUTHERN I-25 CORRIDOR. AFTERNOON HEATING HAS TRIGGERED ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ACROSS THE MOUNTAINS...BUT WITH LACK OF FORCING COVERAGE HAS BEEN PRETTY SPARSE AND LACK OF MOISTURE HAS LIMITED UPDRAFT STRENGTH. HRRR HAS BEEN TRENDING DRIER WITH EACH RUN...SO HAVE DECREASED POPS FOR THE EVENING HOURS...AND CONVECTION SHOULD DIMINISH QUICKLY THIS EVENING ONCE THE SUN GOES DOWN. SOUTHWEST FLOW ALOFT INCREASES FOR TUESDAY...WHICH SHOULD INCREASE WINDS ACROSS THE FORECAST AREA BY AFTERNOON. MOISTURE BEGINS TO INCREASE ACROSS THE SOUTHWEST MOUNTAINS EARLY TUESDAY MORNING...WITH SOME ISOLATED SHOWERS SPREADING IN. WITH AFTERNOON HEATING...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS DURING THE AFTERNOON...THEN SPREAD OFF INTO THE ADJACENT PLAINS DURING THE LATE AFTERNOON. ONE CONCERN FOR TOMORROW IS THE POTENTIAL FOR NEAR CRITICAL FIRE WEATHER CONDITIONS ALONG PORTIONS OF THE I-25 CORRIDOR. GFS IS DRIER WITH SFC DEW POINTS (UPPER 20S)...WHILE NAM ACTUALLY INCREASES THEM IN THE AFTERNOON (30S TO AROUND 40) AS CLOUDS INCREASE AND -SHRA/VIRGA DRIFT OFF THE MOUNTAINS. LATEST 4KM WRF ALSO SHOWS THIS MOISTENING TREND DURING THE AFTERNOON. FARTHER EAST...SOUTHERLY FLOW KEEPS MID- UPPER 30S ACROSS THE FAR EAST PLAINS WHICH RESULTS IN AFTERNOON HUMIDITIES IN THE 18-25% RANGE...TOO HIGH FOR FIRE WEATHER HIGHLIGHTS. QUITE A BIT OF HUERFANO COUNTY HAD SOME GOOD RAIN FROM THE SYSTEM OVER THE WEEKEND...SO THE MOST LIKE SPOTS FOR MARGINAL CRITICAL FIRE WEATHER CONDITIONS TO DEVELOP WOULD BE PUEBLO COUNTY...SOUTHERN EL PASO...AND WESTERN LAS ANIMAS COUNTIES. LOCAL WRF IS SLOW TO INCREASE WINDS ACROSS PUEBLO COUNTY UNTIL LATE AFTERNOON WHICH MAY LIMIT THE DURATION TO LESS THAN THE 3 HR REQUIRED MINIMUM. WITH ALL THESE MARGINAL CRITERIA...DECIDED NOT TO HOIST ANY FIRE WEATHER HIGHLIGHTS...BUT THIS WILL BE MONITORED CLOSELY AS MORE HIGH RES MODELS BEGIN TO RESOLVE THESE FINER DETAILS. OTHERWISE...ANOTHER ROUND OF ISOLATED TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS WILL DEVELOP. THESE WILL BE PRETTY HIGH BASED AND MORE LIKELY TO PRODUCE GUSTY WINDS AND LIGHTNING AND ONLY SOME BRIEF LIGHT TO MODERATE RAINFALL AMOUNTS IN SPOTTY AREAS. A MARGINALLY STRONG THUNDERSTORM OR TWO WILL BE POSSIBLE ALONG A DIFFUSE DRY LINE ACROSS THE FAR SOUTHEAST PLAINS DURING THE AFTERNOON...BUT CAPES WILL ONLY BE RUNNING AROUND 500 J/KG OR LESS...WITH GUSTY WINDS THE PRIMARY STORM THREAT. -KT .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 328 PM MDT MON APR 21 2014 RELATIVELY ACTIVE LONGER TERM PATTERN SETTING UP OVER THE FORECAST DISTRICT...ESPECIALLY FROM THE WEEKEND INTO EARLY NEXT WEEK. PRIMARY LONGER TERM METEOROLOGICAL CHALLENGES INCLUDE BUT ARE NOT LIMITED TO POPS...TEMPERATURES...ELEVATED FIRE WEATHER CONCERNS AT TIMES AND THE POTENTIAL FOR SOME STRONG TO POTENTIALLY SEVERE THUNDERSTORMS OVER/NEAR EASTERN SECTIONS AT TIMES. RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER MODEL SIMULATIONS INDICATE THAT INITIAL UPPER DISTURBANCE WILL MOVE PRIMARILY TO THE NORTH OF THE CWFA FROM WEDNESDAY INTO WEDNESDAY NIGHT ALLOWING FOR SOME SHOWER ACTIVITY OVER MAINLY NORTHERN SECTIONS AS WELL AS INCREASED DRY SOUTHWESTERLY SURFACE FLOW OVER EASTERN PORTIONS OF THE FORECAST DISTRICT...THEREFORE WILL ALLOW THE FIRE WEATHER WATCH TO REMAIN IN EFFECT FROM WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING FOR THE INTERSTATE 25 CORRIDOR AS WELL AS OVER ALL OF THE SOUTHEASTERN COLORADO PLAINS. IN ADDITION...A SURFACE DRY LINE IS EXPECTED TO SET-UP NEAR THE COLORADO/KANSAS BORDER WEDNESDAY...WITH THE SPC DAY 3 CONVECTIVE OUTLOOK PAINTING A SLIGHT RISK OF SEVERE THUNDERSTORMS ON WEDNESDAY JUST EAST OF THE COLORADO/KANSAS BORDER. WFO PUEBLO WILL MONITOR CLOSELY. THEN BASICALLY DRY ZONAL TO SOUTHWESTERLY UPPER FLOW IS EXPECTED TO DEVELOP OVER SOUTHERN COLORADO FROM LATER WEDNESDAY NIGHT INTO SATURDAY MORNING IN ADVANCE OF NEXT APPROACHING SYSTEM. AT THIS TIME WILL DEPICT GENERALLY DRY CONDITIONS DURING THIS TIME-FRAME IN COMBINATION WITH ELEVATED FIRE WEATHER CONCERNS DURING THE AFTERNOON AND EVENING HOURS OVER PORTIONS OF THE SAN LUIS VALLEY AND SOUTHEASTERN COLORADO PLAINS. NEXT POTENTIALLY SIGNIFICANT SYSTEM IS PROJECTED TO BEGIN IMPACTING THE FORECAST DISTRICT FROM LATER SATURDAY INTO EARLY NEXT WEEK. COMPUTER SIMULATIONS HAVE VARYING FORECAST TRACKS WITH THIS SYSTEM WITH GFS FURTHEST SOUTH AND ECMWF AND DGEX FURTHER NORTH THROUGH 18Z NEXT MONDAY. WFO PUEBLO WILL CONTINUE TO CLOSELY MONITOR THE TRACK AND STRENGTH OF THIS POTENTIAL SYSTEM AS IT NEARS THE FORECAST DISTRICT BY THIS WEEKEND. FINALLY...ABOVE SEASONAL LATE APRIL TEMPERATURES ARE PROJECTED TO CONTINUE OVER THE MAJORITY OF THE FORECAST DISTRICT FROM TUESDAY EVENING INTO SUNDAY MORNING WITH BELOW SEASONAL TEMPERATURES THEN ANTICIPATED FROM LATER SUNDAY INTO EARLY NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 328 PM MDT MON APR 21 2014 VFR CONDITIONS EXPECTED AT THE TAF SITES THROUGH THE NEXT 24 HOURS. ISOLATED -SHRA/-TSRA WILL CONTINUE ACROSS THE MOUNTAINS...WITH A FEW WEAK CELLS MOVING INTO THE ADJACENT LOWER ELEVATIONS THROUGH THE EVENING HOURS. PROBABILITIES OF ONE OF THESE IMPACTING THE TAF SITES LOOKS TOO SMALL AT THIS POINT TO WARRANT INCLUSION IN THE TAFS...THOUGH WILL HAVE TO WATCH FOR GUSTY WINDS FROM OUTFLOW BOUNDARIES AS THEY COME OFF THE MOUNTAINS. INCREASING SOUTH TO SOUTHWEST WINDS EXPECTED FOR TUESDAY...WHICH WILL PROBABLY START AT THE KCOS AND KALS TAF SITES DURING THE LATE MORNING TO AROUND THE NOON HOUR. GUSTY WINDS WILL TAKE A LITTLE LONGER TO SET IN AT KPUB. GUSTS UP TO 30 KTS WILL BE POSSIBLE DURING THE AFTERNOON. ANOTHER ROUND OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS DURING THE AFTERNOON...WHICH WILL SPREAD INTO THE SOUTHEAST PLAINS DURING THE LATE AFTERNOON. THESE WILL BE HIGH BASED AND MORE LIKELY TO PRODUCE GUSTY ERRATIC WINDS AND LIGHTNING...ALONG WITH SOME BRIEF LIGHT TO MODERATE RAINFALL. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR COZ226>237. && $$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1108 PM MDT SUN APR 20 2014 .UPDATE... ISSUED AT 850 PM MDT SUN APR 20 2014 UPDATED TO TREND POPS WITH THE LATEST RADAR DATA. SINCE SUN DOWN...MOST OF THE SHOWER ACTIVITY HAS DISSIPATED ACROSS SOUTHERN COLORADO. THE EXCEPTIONS ARE OVER THE PALMER DIVIDE WHERE NEW DEVELOPMENT HAS BEEN PUSHING SOUTH...AND OVER THE EASTERN MOUNTAINS AND ADJACENT PLAINS WEST OF I-25 WHERE WEAK ACTIVITY CONTINUES. HAVE MAINTAINED THESE AREAS SEEING SHOWER ACTIVITY AND ISOLATED THUNDERSTORMS THROUGH MIDNIGHT. ELSEWHERE...DRY CONDITIONS WILL PREVAIL INTO MONDAY MORNING. MOZLEY UPDATE ISSUED AT 550 PM MDT SUN APR 20 2014 ONLY MINOR UPDATES TO THE GOING FORECAST THIS EVENING. AN UPPER LOW IS SITTING OVER FAR SOUTHWEST KANSAS WITH BROAD NORTHERLY FLOW ACROSS EASTERN COLORADO. WEAK SHOWER ACTIVITY CONTINUES ACROSS THE I-25 CORRIDOR AND EASTERN MOUNTAINS WITH ISOLATED THUNDERSTORMS. STRONGER THUNDERSTORM ACTIVITY IS CURRENTLY SITUATED NEAR THE UPPER LEVEL DISTURBANCE ALONG THE KANSAS BORDER. LIGHTNING ALONG WITH 40 MPH OUTFLOW WINDS AND PEA SIZE HAIL ARE ALL POSSIBLE IN THE STORMS NEAR THE KANSAS BORDER. MODELS RAPIDLY DISSIPATE SHOWER ACTIVITY AFTER SUNSET WITH ALL AREAS DRY BY MIDNIGHT. AREAS OUT EAST NEAR THE KANSAS BORDER AND AREAS DOWN SOUTH ALONG THE NEW MEXICO BORDER WILL HOLD OUT THE LONGEST. MOZLEY && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 330 PM MDT SUN APR 20 2014 UPPER LOW OVER SE CO/NW NM AND THE TX/OK PANHANDLES WILL CONTINUE MOVING EAST THIS EVENING. SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ACROSS SOUTHEAST CO ON THE NORTHWEST SIDE OF THE UPPER LOW IN AREA OF WEAK ISENTROPIC UPGLIDE AND INSTABILITY. RESIDUAL MOISTURE ACROSS THE AREA BEHIND THE SYSTEM HAS BEEN SUFFICIENT TO TRIGGER SOME SCATTERED SHOWERS ACROSS THE MOUNTAINS WITH SOME AFTERNOON HEATING...AND APPEARS THAT TAIL END OF PASSING SHORTWAVE TO THE NORTH MAY BE AIDING THUNDERSTORM INITIATION ACROSS NW CO. THIS LATTER FEATURE WILL CLIP THROUGH NRN CO THIS AFTERNOON AND EVENING. MAIN CONCERN FOR THE SHORT TERM WILL BE POTENTIAL FOR RUN-OFF PRODUCING RAINFALL ON THE BURN SCARS. OF GREATER CONCERN WILL BE THE EAST PEAK BURN SCAR WHERE RAINFALL OCCURRED EARLIER THIS MORNING. RADAR ESTIMATES COMPARED WITH GAGES IN THE AREA SUGGEST THAT PORTIONS OF THE BURN SCAR MAY HAVE RECEIVED .50 TO .70 OF RAINFALL. THIS OCCURRED SLOWLY THOUGH WITH RATES UNDER .10 TO .20 PER HOUR...SO NO PROBLEMS WERE NOTED. HOWEVER IF THIS AREA WERE TO GET HIT WITH A STRONGER CELL THIS AFTERNOON OR EVENING...THE SATURATED GROUND MAY RESULT IN SOME QUICK RUN-OFF PROBLEMS. HOWEVER...CLOUD COVER IN THIS AREA MAY ALSO HELP KEEP THE ATMOSPHERE MORE STABLE...SO RISK SEEMS LOW AT THIS POINT. A LITTLE BETTER HEATING HAS BEEN REALIZED FARTHER NORTH ACROSS THE PIKES PEAK REGION. HOWEVER...DEW POINTS HAVE BEEN DROPPING INTO THE LOWER 30S AND LATEST HRRR DROPS THEM INTO THE UPPER 20S BY LATE AFTERNOON WHICH REALLY CUTS BACK ON THE INSTABILITY AND RESULTANT THUNDERSTORM STRENGTH. WHILE CAN`T ENTIRELY RULE OUT AN ISOLATED STRONGER CELL IMPACTING THE WALDO CANYON BURN SCAR...THINK THIS CHANCE IS FAIRLY LOW...AND IF IT DID WOULD PROBABLY NOT LAST LONG ENOUGH TO PRODUCE MUCH MORE THAN SOME MINOR RUN-OFF ISSUES AT BEST. ALSO...WATCHING THE SOUTHEAST PLAINS OF THE STATE IN VCNTY OF UPPER LOW...WHERE LOW LEVEL LAPSE RATES COULD BECOME STEEP ENOUGH TO PRODUCE A SHORT LIVED NON-SUPERCELL TORNADO/LANDSPOUT. SO FAR...UPDRAFT STRENGTHS HAVEN`T BEEN STRONG ENOUGH TO STRETCH ANY LOW LEVEL VORTICITY...BUT WILL CONTINUE TO WATCH IT CLOSELY AS SPC MESO-ANALYSIS DOES SHOW A POCKET OF HIGH NON-SUPERCELL TOR INDICES ACROSS PORTIONS OF THE AREA. ALL ACTIVITY SHIFTS TO THE EAST AND SOUTHEAST FAIRLY QUICKLY THROUGH LATE AFTERNOON AND EARLY EVENING...SO THESE THREATS SHOULD QUICKLY COME TO AN END WITH THE LOSS OF HEATING. ON MONDAY...UPPER RIDGE TRANSLATES IN...BUT THERE WILL STILL BE ENOUGH RESIDUAL MOISTURE FOR ISOLATED SHOWERS AND THUNDERSTORMS IN AND NEAR THE MOUNTAINS. OTHERWISE...TEMPERATURES SHOULD BE A LITTLE WARMER THAN TODAYS...ESPECIALLY IN AND NEAR THE SOUTHEAST MOUNTAINS WHERE CLOUDS HAVE HELD TEMPERATURES DOWN TODAY. -KT .LONG TERM...(MONDAY NIGHT THROUGH NEXT SUNDAY) ISSUED AT 330 PM MDT SUN APR 20 2014 NOT MANY ADJUSTMENTS NEEDED FROM PREVIOUS LONGER TERM THINKING WITH MAIN LONGER TERM ISSUES BEING ABOVE CLIMATOLOGICAL TEMPERATURES FROM MONDAY NIGHT INTO EARLY NEXT WEEKEND...ISOLATED TO SCATTERED POPS...PRIMARILY OVER HIGHER TERRAIN LOCATIONS AT TIMES FROM MONDAY NIGHT INTO WEDNESDAY AND THEN AGAIN BY NEXT WEEKEND...INCREASING FIRE WEATHER CONCERNS...BEGINNING WEDNESDAY AFTERNOON AS WELL AS AN INCREASING POTENTIAL FOR STRONGER TO POSSIBLY SEVERE THUNDERSTORMS OVER SECTIONS OF THE SOUTHEASTERN COLORADO PLAINS FROM LATER FRIDAY INTO NEXT WEEKEND. LATEST LONGER TERM COMPUTER SIMULATIONS AND FORECAST MODEL SOUNDINGS SUGGEST THAT VARYING DEGREES OF ZONAL TO SOUTHWESTERLY UPPER FLOW WILL OCCUR OVER THE FORECAST DISTRICT FROM MONDAY NIGHT INTO FRIDAY MORNING. ISOLATED TO SCATTERED SHOWERS AS WELL AS ISOLATED THUNDERSTORMS ARE ANTICIPATED OVER PORTIONS OF THE CWFA FROM MONDAY EVENING INTO WEDNESDAY...FAVORING LOCATIONS SUCH AS THE CENTRAL MOUNTAINS. FOCUS THEN SHIFTS TO INCREASING FIRE WEATHER CONCERNS AT TIMES(ESPECIALLY OVER EASTERN SECTIONS AS WELL AS THE SAN LUIS VALLEY)...PRIMARILY DURING WEDNESDAY AFTERNOON AND EVENING AND THEN POSSIBLY CONTINUING AT TIMES INTO EARLY NEXT WEEKEND. WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY. IN ADDITION...METEOROLOGICAL PARAMETERS ARE BEGINNING TO SIGNAL AN INCREASING POTENTIAL FOR STRONG TO POSSIBLY SEVERE THUNDERSTORM ACTIVITY OVER PORTIONS OF THE SOUTHEASTERN COLORADO PLAINS FROM LATER FRIDAY INTO NEXT WEEKEND AS UPPER SYSTEM IMPACTS THE FORECAST DISTRICT. AS ALWAYS...WFO PUEBLO WILL ALSO CONTINUE TO MONITOR THESE TRENDS CLOSELY. SWITCHING FOCUS TO TEMPERATURES...IT STILL APPEARS THAT BOTH MINIMUM AND MAXIMUM TEMPERATURES WILL RUN ABOVE LATE APRIL CLIMATOLOGICAL AVERAGES FROM MONDAY NIGHT INTO NEXT SATURDAY BEFORE TEMPERATURES DECREASE BY NEXT SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1107 PM MDT SUN APR 20 2014 KALS...VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS. THERE IS A LOW CHANCE FOR SHOWERS AND THUNDERSTORMS OVER THE SAN LUIS VALLEY ON MONDAY AFTERNOON...WHICH MAY IMPACT THE TERMINAL. IF A SHOWER MOVES OVER THE TERMINAL...IT WOULD PRODUCE BRIEF PERIODS OF REDUCED CIGS AND VIS. KCOS AND KPUB...VFR CONDITIONS THROUGH THE NEXT 24 HOURS. WINDS WILL BE DIURNALLY DRIVEN WITH MID AND HIGH CLOUD DECKS. MOZLEY && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MOZLEY AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
902 PM EDT Tue Apr 22 2014 .Near Term [Through Tonight]... Made a few updates to the inherited forecast to reflect current forecast thinking. A weak cold front will slowly continue to move southeastward overnight before stalling out in our far southern CWA early tomorrow morning. There are ongoing showers ahead of the frontal boundary over our northern Georgia and Alabama counties, but due to lack of forcing expect a diminishing trend as they move further south. Hires guidance, such as the HRRR and locally run WRFS, and recent radar trends support this notion. Therefore expect showers ending shortly after midnight before they reach the Florida border. Beginning in the early morning hours before sunrise expect patchy fog to develop throughout the CWA. The greatest chance of seeing more widespread fog exists from Tallahassee westward into the Florida Panhandle during this aforementioned time frame. Otherwise expect a partly cloudy night with lows bottoming out in the upper 50s, except along the immediate coast which will be in the lower 60s. && .Aviation... [Through 00z Thursday]...VFR conditions prevail at TAF issuance time, with some higher ceilings at the northern terminals of DHN and ABY with some scattered SHRA. The SHRA should diminish quickly between 00z and 03z this evening, although some mid-level cloud cover may linger further north. Models indicate the development of some areas of low CIGS and fog overnight - particularly between 07z and 12z - with IFR or briefly LIFR VIS possible. Confidence is higher in this occurring at TLH, ECP, and VLD. VFR expected again tomorrow after the fog dissipates, with an afternoon sea breeze wind shift at ECP. && .Prev Discussion [205 PM EDT]... .Short Term [Wednesday Through Thursday Night]... The mid/upper level local pattern begins with shortwave trough well into Atlc replaced by amplified ridging...rising heights and subsidence. At surface...remnants of Tuesday`s cold front limps into our SE Big Bend Swwd into our Nrn marine area. In its wake...area model soundings show flow sfc-upper levels NWLY however with proximity of front...PWATS remain around 1 inch. During the rest of the period...local ridge amplifies into Thurs ahead of upstream trough/low developing over Wrn states. By aftn... this low pivots Newd resulting in Ern ridge flattening yielding near zonal flow. At surface...increasingly diffuse front lingers in place before likely lifting Nwd late Wed into Thurs as high develops over NE Gulf and...along with ridge across Nrn Gulf Coast...remains established into Thurs night. The combination of strong mid/upper subsidence and weakening front south will yield partly to mostly sunny skies. The lifting front will shift local winds to onshore on Thurs with rising humidity as reflected in model PWATS which remain around 1 inch. So it will feel muggy. With very dry mid/upper levels...at best isold POPs near the front. Temperatures will be near climatology through the period, with lows in the 50s and highs in the lower to mid 80s. .Long Term [Friday Through Tuesday]... On Friday, a weak surface trough will extend down from the Great Lakes. This trough will become oriented SW to NE as the parent low moves off to the northeast and the trough weakens. Southerly flow off the Gulf and weak forcing will cause a slight chance of thunderstorms over the the northern half of our area Friday through Saturday. Ridging will settle in on Sunday with southerly surface flow which will bring highs in the mid to upper 80s during the day. At the end of the period both the GFS and EURO show a very amplified pattern emerging with a deep upper-level trough digging down over the southern Plains. While these models differ some in timing and structure, they both show a blocking pattern emerging with a strong upper ridge in the west and an amplified deep trough in the east. This system should be our best chance of seeing showers and thunderstorms in the extended period. .Marine... Despite the front approaching from the north into tonight, then stalling across extreme North FL through Thursday, winds and seas on the whole will remain quite low. The exception will be a moderate increase in onshore winds and chop near the coast each afternoon because of the daily sea breeze. .Fire Weather... Red Flag conditions are not expected through the remainder of the week. .Hydrology... Most of our area rivers are above normal stage with many in flood stage. The Choctawhatchee at Bruce is at major flood stage, several others are in moderate. Most area rivers will crest soon or have already crested. The exception is the Suwannee River chich will rise slowly for the remainder of the week. Rainfall amounts are expected to be less than 0.25 inch and will have little impact on area river levels. The most up-to-date river forecast information can always be found on our AHPS page (below). http:/water.weather.gov/ahps2/index.php?wfo=tae. && .Preliminary Point Temps/PoPs... Tallahassee 58 83 58 82 61 / 10 0 0 10 0 Panama City 61 78 63 75 64 / 10 0 0 10 0 Dothan 58 83 57 83 61 / 40 0 0 10 10 Albany 56 83 56 83 60 / 50 0 0 20 10 Valdosta 57 84 59 83 60 / 30 10 10 20 0 Cross City 60 83 59 82 59 / 10 10 10 20 0 Apalachicola 62 76 63 74 63 / 10 0 0 10 0 && .TAE Watches/Warnings/Advisories... FL...None. GA...None. AL...None. GM...None. && $$ NEAR TERM...NAVARRO/GOULD SHORT TERM...BLOCK LONG TERM...BLOCK AVIATION...LAMERS MARINE...BLOCK FIRE WEATHER...MOORE HYDROLOGY...BOLDEN
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1047 PM EDT TUE APR 22 2014 .SYNOPSIS... A WEAK COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. HIGH PRESSURE BEHIND THE FRONT WILL DOMINATE WEDNESDAY AND THURSDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... A COLD FRONT CURRENTLY STRETCHED ALONG THE WESTERN APPALACHIANS WILL CROSS THE REGION TONIGHT. SHOWER ACTIVITY AHEAD OF THE FRONT HAS ENDED ACROSS THE MIDLANDS AND CENTRAL SAVANNAH RIVER AREA. DRY FORECAST FOR THE REST OF THE NIGHT. CLEARING SKIES STILL ON TAP WITH EARLY MORNING LOWS IN THE LOWER TO MIDDLE 50S. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... BEHIND THE FRONT WEAK COLD ADVECTION EXPECT AND PROBABLY OFFSET BY DOWNSLOPE FLOW IN THE AFTERNOON. COOLER BUT SEASONABLE TEMPERATURES IN THE MID TO UPPER 70S MOST AREAS UNDER FULL SUN AS RIDGE BUILDS ACROSS THE AREA. THE RIDGE WILL BE OVER THE AREA WEDNESDAY NIGHT AND GIVEN DRY AIR MASS EXPECT RADIATIONAL COOLING CONDITIONS THURSDAY MORNING...FORECAST MINIMUM TEMPERATURES ON COOL SIDE OF MOS CONSENSUS. RIDGE MOVES OFF THE COAST THURSDAY AND WITH RETURN FLOW EXPECT A MODEST INCREASE IN LOW-LEVEL MOISTURE DURING THE DAY AND NIGHT. TEMPERATURES SLIGHTLY WARMER THAN WEDNESDAY WITH AIR MASS MODIFICATION AND SOUTH FLOW DEVELOPING. UPPER LEVEL TROUGH APPROACHING THE REGION LATE THURSDAY NIGHT...EXPECT AN INCREASE IN CLOUDINESS. ISOLATED SHOWERS MAY MOVE INTO THE WESTERN MIDLANDS AND PIEDMONT TOWARD MORNING ASSOCIATED WITH SHORT WAVE TROUGH. && .LONG TERM /FRIDAY THROUGH TUESDAY/... THE GFS AND ECMWF CONTINUE TO SHOW SOME MOISTURE INCREASE ASSOCIATED WITH A DIFFUSE FRONT/TROUGH FRIDAY. NAM MODEL SHOWS A MORE ROBUST SHORT WAVE THAN ECMWF AND GFS. ENSEMBLE POPS REMAIN LOW FRIDAY. CONTINUE LOW CHANCE POPS ASSOCIATED WITH FAST MOVING SHORT WAVE TROUGH. FRONT MAY STALL ACROSS THE AREA OVER THE WEEKEND...BUT MOISTURE WILL BE LIMITED. SEASONABLE OR SLIGHTLY ABOVE NORMAL TEMPERATURES OVER THE WEEKEND. UPPER LEVEL LOW MOVING INTO THE MIDWEST LATE IN THE PERIOD. DEEP SURFACE LOW DEVELOPING IN THE MISSISSIPPI VALLEY. MOISTURE INCREASE MONDAY INTO TUESDAY AHEAD OF THE SYSTEM WITH INCREASING CHANCE RAIN AND POSSIBLY COOLER TEMPERATURES. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... HIGH LEVEL CLOUDS WILL CLEAR THE TAF SITES BY AS A WEAK COLD FRONT MOVES EAST OF THE MIDLANDS AND CSRA. GFS/LAMP MODELS INDICATING A PERIOD OF MVFR FOG 08Z-13Z AND EVEN IFR AT AGS JUST BEFORE SUNRISE. NAM AND RUC DEVELOP A LOW LEVEL JET FOR BOUNDARY LAYER MIXING...THUS NO FOG. GIVEN THE POSSIBILITY OF WINDS DIMINISHING...HAVE INCLUDED MVFR FOG AT THE FOG PRONG LOCATIONS OF AGS/OGB. AFTER 14Z...VFR EXPECTED ALL SITES WITH NORTH TO NORTHWEST WIND 10 KTS OR LESS AND MAINLY CLEAR SKIES. .EXTENDED AVIATION OUTLOOK...ANOTHER COLD FRONT WILL CROSS THE REGION FRIDAY WITH THE POTENTIAL FOR SHOWERS/TSTMS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
105 PM CDT MON APR 21 2014 .SHORT TERM /TODAY/... ISSUED AT 343 AM CDT MON APR 21 2014 STUBBORN COLD FRONT WILL FINALLY SWING THROUGH THE STATE TODAY AND BRING SCATTERED SHOWERS AND A FEW THUNDERSTORMS TO THE FORECAST AREA DURING MUCH OF THE MORNING. FRONT LOOKS TO CREEP INTO NORTHWEST PORTIONS OF THE FORECAST AREA BY AROUND 14-15Z AND CONTINUE TO PUSH SOUTHEAST AND CLEAR MUCH OF THE FORECAST AREA BY AROUND 00Z TUESDAY OR SLIGHTLY SOONER. LEANED TOWARD THE SLOWER SREF/GFS/ECMWF WRT TO WINDS AND TEMPERATURES TODAY. 21.05Z HRRR IS A LITTLE TOO FAST WITH THE PRECIP MOVING EAST AND THE 21.03Z HOPWRF IS LIGHTER ON THE COVERAGE. REGARDLESS...UTILIZED A BLEND OF THE TWO FOR POPS/WX TRENDS THROUGH MIDDAY TODAY...THEN THE 21.03Z SREF/21.00Z HIRES-ARW/NMM FOR TRENDS THIS AFTERNOON. SURFACE LOW LOCATED OVER NORTHWEST IOWA/SOUTHWEST MINNESOTA WITH COLD FRONT EXTENDING SOUTHWEST INTO NEBRASKA. WEAK AND BROAD LARGE SCALE FORCING AHEAD THIS COLD FRONT AS WELL AS ISENTROPIC LIFT WILL CONTINUE TO FEED MOISTURE INTO THE FORECAST AREA THIS MORNING. INSTABILITY NOT IMPRESSIVE TODAY BUT ENOUGH AVAILABLE TO KEEP MENTION OF THUNDER. HAVE BULK OF THE HIGHER POPS OVER WESTERN AND NORTHERN IOWA THROUGH 12-14Z BEFORE SHIFTING FURTHER SOUTHEAST LATE THIS MORNING. BELIEVE MUCH OF THE PRECIP WILL QUICKLY DISSIPATE PAST 18-20Z OR BE CONFINED TO THE SOUTHEAST CORNER OF THE FORECAST AREA. HAVE NON-DIURNAL TEMPERATURE TREND MENTIONED ACROSS THE NORTH AS SHOULD SEE THE CAA DEVELOP LATE THIS MORNING AND INCREASE THROUGH THE AFTERNOON. 850MB TEMPS DROP TO +4C TO +6C BY 18Z IN THE NORTH. GUSTY NORTH TO NORTHWEST WINDS BEHIND THE FRONT WITH WINDS ATOP THE MIXED LAYER INCREASING TO AROUND 25 TO 30 KNOTS. MUCH DRIER AIR MASS FILTERS INTO THE STATE AS WELL WITH SURFACE DEW POINTS DROPPING INTO UPPER 30S AND LOWER 40S OVER THE NORTHWEST. RH VALUES DECREASE TO NEAR 25 PERCENT ACROSS A SMALL WESTERN PORTION OF FORECAST AREA. THOUGH AN INCREASED FIRE WEATHER DANGER TODAY...HELD OFF ON RED FLAG WARNING DUE TO CRITERIA NOT BEING MET WIDESPREAD. .LONG TERM /TONIGHT THROUGH SATURDAY/... ISSUED AT 343 AM CDT MON APR 21 2014 EARLY IN THE PERIOD...FEW CONCERNS. SYSTEM ON THE WAY OUT BY 00Z TONIGHT WITH SECONDARY COLD FRONT NOW OVER NORTHERN MN DROPPING SOUTHEAST ACROSS THE REGION TONIGHT...BRINGING DRIER AND COOLER AIR INTO THE REGION BY MORNING. DESPITE WARM TEMPS THE PAST FEW DAYS... MORNING LOWS TONIGHT WILL BE MUCH COOLER WITH MID 30S NORTH TO MID 40S SOUTH. TUESDAY LOOKS LIKE A NICE DAY WITH GENERALLY SUNNY SKIES AND A FEW FAIR WX CUMULUS DURING THE MID AFTERNOON AS HIGH PRESSURE DROPS SOUTHEAST THROUGH THE DAY...KEEPING WINDS LIGHT. LITTLE MIXING TO PROMOTE MUCH WARMING OTHER THAN SUNSHINE...SO WILL STICK WITH HIGHS IN THE UPPER 50S NORTHEAST AND MID 60S ACROSS THE WEST. MODELS DIFFER SLIGHTLY ON TIMING OF UPSTREAM WAVE AND EXPECTED WARM AIR ADVECTION/CLOUDS AND APPROACHING SHOWERS FOR WED. OVERALL...INCREASE IN CLOUDS EXPECTED LATE DAY WEST TUESDAY WITH SHOWERS NEARING THE WESTERN BORDER BY 12Z. THOUGH THUNDER MORE LIKELY ACROSS THE HIGH PLAINS AND NE...DRY AIR OVER IOWA WILL COOL AND DIMINISH INSTABILITY WHEN INITIAL PUSH OF MOISTURE ARRIVES. MODELS SHOW LITTLE INSTABILITY UNTIL AFTERNOON WED AND THAT AGAIN IS LESS THAN YESTERDAYS SOLUTIONS. THUS...HAVE TRIMMED AREAL COVERAGE OF THUNDER TO ISO WEST IN THE MORNING AND ISO EAST/SCT FAR WEST IN THE PM HOURS WEDNESDAY WITH THE FIRST REAL SURGE OF THETAE ADVECTION. AS THE SYSTEM CROSSES THE REGION...CONFIDENCE IN EVOLUTION OF SYSTEM HAS LESSENED SLIGHTLY. MODELS CONTINUE TO HAVE GENERAL TRENDS SIMILAR... BUT DETAILS DIFFER. OVERALL THE BETTER INSTABILITY WILL REMAIN WEST OF THE AREA UNTIL NEARER 00Z THUR...THEN WEAKEN OVERNIGHT PRIOR TO INCREASING AGAIN FROM LATE MORNING THUR THROUGH 00Z FRI. STILL SOME CONCERNS ABOUT OVERNIGHT CONVECTION ACROSS SOUTH/CENTRAL SECTIONS WED NIGHT AS SOME BULK SHEAR COULD AID SVR POTENTIAL. BOTH THE 00Z GFS AND THE 12Z/NEW 00Z EURO NOW SUGGEST THAT THE LOW WILL TRACK NORTHEAST ACROSS IA NEARLY EXITING OUR FORECAST AREA BY 18Z THUR...KEEPING THE BEST INSTABILITY AND SVR POTENTIAL EAST OF THE AREA BY THURSDAY AFTERNOON. FOR NOW...WILL CONTINUE TO MONITOR POTENTIAL BUT OVERALL CHANCES WOULD REMAIN CONDITIONAL ON ANY BETTER ALIGNMENT OF FORCING AND STRONGER INSTABILITY THURSDAY. BEYOND THUR AFTERNOON...MORE UNCERTAINTY IS ARISING IN THE REMAINDER OF THE FORECAST. MODELS HANDLING THE DEPARTURE OF THE SYSTEM WITH DIFFERING SPEED THUR NIGHT AND FRIDAY DUE TO A SECONDARY H500 SYSTEM OVER CENTRAL CANADA POTENTIALLY PHASING WITH THE DEPARTING H500 LOW. BOTH THE GEM/EURO TAKE THE FIRST SYSTEM EAST QUICKLY ENOUGH TO PREVENT MUCH PHASING WHILE THE GFS HOLDS ON TO A TROUGH EXTENDING WEST INTO MN. THIS RESULTS IN A FARTHER WEST RIDGE AXIS OVER CANADA THAT DROPS SOUTH INTO THE NORTHERN PLAINS AND DRIVES THE JET STREAM FARTHER SOUTH...DIRECTLY NEXT WEEKENDS STORM SOUTH OF IOWA. THE GEM/EURO SHOW ONLY A SLIGHT DELAY IN TIMING AND STILL BRING RAIN BACK INTO THE AREA FOR THE WEEKEND. FOR NOW THE GFS SHOWS TOO DRASTIC A CHANGE FOR SUCH A SMALL H500 FEATURE. DUE TO UNCERTAINTY...WILL CUT BACK ON POP CHANCE AT ONSET OF PRECIP EVENT NEXT SATURDAY BUT WILL STILL KEEP POP INCREASING WITH TIME THROUGH SUNDAY. TEMPS WILL HAVE EVEN GREATER UNCERTAINTY NOW...AS TIED TO CHANGES IN EVOLUTION AND TRACK OF WEEKEND UPPER AIR PATTERN AND STORM TRACK. NEWEST 21/00Z EURO STILL KEEPS TREND OF WET WEATHER NEXT WEEKEND...WHILE THE GFS REMAINS DRY. OVERALL THE EURO TENDS TO PERFORM MORE CONSISTENTLY AFTER FCST 120 HOURS SO WILL LEAN TOWARD GEM/EURO SOLUTIONS OF WETTER WEATHER SAT/SUN. AS MENTIONED IN PREVIOUS NIGHTS AFDS...THERE IS A CONSISTENT SIGNAL OF ENERGY STRETCHING FROM THE NORTH CENTRAL PACIFIC EAST TO THE PLAINS...WHICH WOULD FAVOR INCLEMENT WEATHER HERE. && .AVIATION...21/18Z ISSUED AT 1257 PM CDT MON APR 21 2014 COLD FRONT ACROSS CENTRAL IOWA WILL EXIT INTO ILLINOIS AND MISSOURI BY LATE THIS AFTERNOON. STRONG NORTHWEST SURFACE WINDS ARE EXPECTED ON THE BACKSIDE OF THE FRONT THIS AFTERNOON BEFORE DIMINISHING SOME THIS EVENING AS MIXING DECREASES. SCATTERED SHOWERS AND THUNDERSTORMS IN THE VICINITY OF KOTM WILL DEPART WITH THE FRONT AS WELL. SCATTERED AREAS OF MVFR CEILINGS WILL GIVE WAY TO WIDESPREAD VFR CONDITIIONS BY THIS EVENING ACROSS ALL OF CENTRAL IOWA WITH THESE CONDITIONS PERSISTING FOR THE REMAINDER OF THE FORECAST PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...COGIL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
652 AM CDT MON APR 21 2014 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TODAY/... ISSUED AT 343 AM CDT MON APR 21 2014 STUBBORN COLD FRONT WILL FINALLY SWING THROUGH THE STATE TODAY AND BRING SCATTERED SHOWERS AND A FEW THUNDERSTORMS TO THE FORECAST AREA DURING MUCH OF THE MORNING. FRONT LOOKS TO CREEP INTO NORTHWEST PORTIONS OF THE FORECAST AREA BY AROUND 14-15Z AND CONTINUE TO PUSH SOUTHEAST AND CLEAR MUCH OF THE FORECAST AREA BY AROUND 00Z TUESDAY OR SLIGHTLY SOONER. LEANED TOWARD THE SLOWER SREF/GFS/ECMWF WRT TO WINDS AND TEMPERATURES TODAY. 21.05Z HRRR IS A LITTLE TOO FAST WITH THE PRECIP MOVING EAST AND THE 21.03Z HOPWRF IS LIGHTER ON THE COVERAGE. REGARDLESS...UTILIZED A BLEND OF THE TWO FOR POPS/WX TRENDS THROUGH MIDDAY TODAY...THEN THE 21.03Z SREF/21.00Z HIRES-ARW/NMM FOR TRENDS THIS AFTERNOON. SURFACE LOW LOCATED OVER NORTHWEST IOWA/SOUTHWEST MINNESOTA WITH COLD FRONT EXTENDING SOUTHWEST INTO NEBRASKA. WEAK AND BROAD LARGE SCALE FORCING AHEAD THIS COLD FRONT AS WELL AS ISENTROPIC LIFT WILL CONTINUE TO FEED MOISTURE INTO THE FORECAST AREA THIS MORNING. INSTABILITY NOT IMPRESSIVE TODAY BUT ENOUGH AVAILABLE TO KEEP MENTION OF THUNDER. HAVE BULK OF THE HIGHER POPS OVER WESTERN AND NORTHERN IOWA THROUGH 12-14Z BEFORE SHIFTING FURTHER SOUTHEAST LATE THIS MORNING. BELIEVE MUCH OF THE PRECIP WILL QUICKLY DISSIPATE PAST 18-20Z OR BE CONFINED TO THE SOUTHEAST CORNER OF THE FORECAST AREA. HAVE NON-DIURNAL TEMPERATURE TREND MENTIONED ACROSS THE NORTH AS SHOULD SEE THE CAA DEVELOP LATE THIS MORNING AND INCREASE THROUGH THE AFTERNOON. 850MB TEMPS DROP TO +4C TO +6C BY 18Z IN THE NORTH. GUSTY NORTH TO NORTHWEST WINDS BEHIND THE FRONT WITH WINDS ATOP THE MIXED LAYER INCREASING TO AROUND 25 TO 30 KNOTS. MUCH DRIER AIR MASS FILTERS INTO THE STATE AS WELL WITH SURFACE DEW POINTS DROPPING INTO UPPER 30S AND LOWER 40S OVER THE NORTHWEST. RH VALUES DECREASE TO NEAR 25 PERCENT ACROSS A SMALL WESTERN PORTION OF FORECAST AREA. THOUGH AN INCREASED FIRE WEATHER DANGER TODAY...HELD OFF ON RED FLAG WARNING DUE TO CRITERIA NOT BEING MET WIDESPREAD. .LONG TERM /TONIGHT THROUGH SATURDAY/... ISSUED AT 343 AM CDT MON APR 21 2014 EARLY IN THE PERIOD...FEW CONCERNS. SYSTEM ON THE WAY OUT BY 00Z TONIGHT WITH SECONDARY COLD FRONT NOW OVER NORTHERN MN DROPPING SOUTHEAST ACROSS THE REGION TONIGHT...BRINGING DRIER AND COOLER AIR INTO THE REGION BY MORNING. DESPITE WARM TEMPS THE PAST FEW DAYS... MORNING LOWS TONIGHT WILL BE MUCH COOLER WITH MID 30S NORTH TO MID 40S SOUTH. TUESDAY LOOKS LIKE A NICE DAY WITH GENERALLY SUNNY SKIES AND A FEW FAIR WX CUMULUS DURING THE MID AFTERNOON AS HIGH PRESSURE DROPS SOUTHEAST THROUGH THE DAY...KEEPING WINDS LIGHT. LITTLE MIXING TO PROMOTE MUCH WARMING OTHER THAN SUNSHINE...SO WILL STICK WITH HIGHS IN THE UPPER 50S NORTHEAST AND MID 60S ACROSS THE WEST. MODELS DIFFER SLIGHTLY ON TIMING OF UPSTREAM WAVE AND EXPECTED WARM AIR ADVECTION/CLOUDS AND APPROACHING SHOWERS FOR WED. OVERALL...INCREASE IN CLOUDS EXPECTED LATE DAY WEST TUESDAY WITH SHOWERS NEARING THE WESTERN BORDER BY 12Z. THOUGH THUNDER MORE LIKELY ACROSS THE HIGH PLAINS AND NE...DRY AIR OVER IOWA WILL COOL AND DIMINISH INSTABILITY WHEN INITIAL PUSH OF MOISTURE ARRIVES. MODELS SHOW LITTLE INSTABILITY UNTIL AFTERNOON WED AND THAT AGAIN IS LESS THAN YESTERDAYS SOLUTIONS. THUS...HAVE TRIMMED AREAL COVERAGE OF THUNDER TO ISO WEST IN THE MORNING AND ISO EAST/SCT FAR WEST IN THE PM HOURS WEDNESDAY WITH THE FIRST REAL SURGE OF THETAE ADVECTION. AS THE SYSTEM CROSSES THE REGION...CONFIDENCE IN EVOLUTION OF SYSTEM HAS LESSENED SLIGHTLY. MODELS CONTINUE TO HAVE GENERAL TRENDS SIMILAR... BUT DETAILS DIFFER. OVERALL THE BETTER INSTABILITY WILL REMAIN WEST OF THE AREA UNTIL NEARER 00Z THUR...THEN WEAKEN OVERNIGHT PRIOR TO INCREASING AGAIN FROM LATE MORNING THUR THROUGH 00Z FRI. STILL SOME CONCERNS ABOUT OVERNIGHT CONVECTION ACROSS SOUTH/CENTRAL SECTIONS WED NIGHT AS SOME BULK SHEAR COULD AID SVR POTENTIAL. BOTH THE 00Z GFS AND THE 12Z/NEW 00Z EURO NOW SUGGEST THAT THE LOW WILL TRACK NORTHEAST ACROSS IA NEARLY EXITING OUR FORECAST AREA BY 18Z THUR...KEEPING THE BEST INSTABILITY AND SVR POTENTIAL EAST OF THE AREA BY THURSDAY AFTERNOON. FOR NOW...WILL CONTINUE TO MONITOR POTENTIAL BUT OVERALL CHANCES WOULD REMAIN CONDITIONAL ON ANY BETTER ALIGNMENT OF FORCING AND STRONGER INSTABILITY THURSDAY. BEYOND THUR AFTERNOON...MORE UNCERTAINTY IS ARISING IN THE REMAINDER OF THE FORECAST. MODELS HANDLING THE DEPARTURE OF THE SYSTEM WITH DIFFERING SPEED THUR NIGHT AND FRIDAY DUE TO A SECONDARY H500 SYSTEM OVER CENTRAL CANADA POTENTIALLY PHASING WITH THE DEPARTING H500 LOW. BOTH THE GEM/EURO TAKE THE FIRST SYSTEM EAST QUICKLY ENOUGH TO PREVENT MUCH PHASING WHILE THE GFS HOLDS ON TO A TROUGH EXTENDING WEST INTO MN. THIS RESULTS IN A FARTHER WEST RIDGE AXIS OVER CANADA THAT DROPS SOUTH INTO THE NORTHERN PLAINS AND DRIVES THE JET STREAM FARTHER SOUTH...DIRECTLY NEXT WEEKENDS STORM SOUTH OF IOWA. THE GEM/EURO SHOW ONLY A SLIGHT DELAY IN TIMING AND STILL BRING RAIN BACK INTO THE AREA FOR THE WEEKEND. FOR NOW THE GFS SHOWS TOO DRASTIC A CHANGE FOR SUCH A SMALL H500 FEATURE. DUE TO UNCERTAINTY...WILL CUT BACK ON POP CHANCE AT ONSET OF PRECIP EVENT NEXT SATURDAY BUT WILL STILL KEEP POP INCREASING WITH TIME THROUGH SUNDAY. TEMPS WILL HAVE EVEN GREATER UNCERTAINTY NOW...AS TIED TO CHANGES IN EVOLUTION AND TRACK OF WEEKEND UPPER AIR PATTERN AND STORM TRACK. NEWEST 21/00Z EURO STILL KEEPS TREND OF WET WEATHER NEXT WEEKEND...WHILE THE GFS REMAINS DRY. OVERALL THE EURO TENDS TO PERFORM MORE CONSISTENTLY AFTER FCST 120 HOURS SO WILL LEAN TOWARD GEM/EURO SOLUTIONS OF WETTER WEATHER SAT/SUN. AS MENTIONED IN PREVIOUS NIGHTS AFDS...THERE IS A CONSISTENT SIGNAL OF ENERGY STRETCHING FROM THE NORTH CENTRAL PACIFIC EAST TO THE PLAINS...WHICH WOULD FAVOR INCLEMENT WEATHER HERE. && .AVIATION...21/12Z ISSUED AT 650 AM CDT MON APR 21 2014 SHOWER AND ISOLATED THUNDERSTORMS WILL AFFECT THE TAF SITES THROUGH THE MORNING HOURS. BRIEF MVFR AND POSSIBLY IFR CONDITIONS ARE POSSIBLE...BUT LOW CONFIDENCE WITH MENTIONING AS THEY WILL HAVE A SHORT DURATION. OTHERWISE...COLD FRONT SWEEPS ACROSS THE STATE AND CLEARS SKIES THIS AFTERNOON FROM NORTHWEST TO SOUTHEAST. INCREASED WINDS THIS AFTERNOON. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
343 AM CDT MON APR 21 2014 .SHORT TERM /TODAY/... ISSUED AT 343 AM CDT MON APR 21 2014 STUBBORN COLD FRONT WILL FINALLY SWING THROUGH THE STATE TODAY AND BRING SCATTERED SHOWERS AND A FEW THUNDERSTORMS TO THE FORECAST AREA DURING MUCH OF THE MORNING. FRONT LOOKS TO CREEP INTO NORTHWEST PORTIONS OF THE FORECAST AREA BY AROUND 14-15Z AND CONTINUE TO PUSH SOUTHEAST AND CLEAR MUCH OF THE FORECAST AREA BY AROUND 00Z TUESDAY OR SLIGHTLY SOONER. LEANED TOWARD THE SLOWER SREF/GFS/ECMWF WRT TO WINDS AND TEMPERATURES TODAY. 21.05Z HRRR IS A LITTLE TOO FAST WITH THE PRECIP MOVING EAST AND THE 21.03Z HOPWRF IS LIGHTER ON THE COVERAGE. REGARDLESS...UTILIZED A BLEND OF THE TWO FOR POPS/WX TRENDS THROUGH MIDDAY TODAY...THEN THE 21.03Z SREF/21.00Z HIRES-ARW/NMM FOR TRENDS THIS AFTERNOON. SURFACE LOW LOCATED OVER NORTHWEST IOWA/SOUTHWEST MINNESOTA WITH COLD FRONT EXTENDING SOUTHWEST INTO NEBRASKA. WEAK AND BROAD LARGE SCALE FORCING AHEAD THIS COLD FRONT AS WELL AS ISENTROPIC LIFT WILL CONTINUE TO FEED MOISTURE INTO THE FORECAST AREA THIS MORNING. INSTABILITY NOT IMPRESSIVE TODAY BUT ENOUGH AVAILABLE TO KEEP MENTION OF THUNDER. HAVE BULK OF THE HIGHER POPS OVER WESTERN AND NORTHERN IOWA THROUGH 12-14Z BEFORE SHIFTING FURTHER SOUTHEAST LATE THIS MORNING. BELIEVE MUCH OF THE PRECIP WILL QUICKLY DISSIPATE PAST 18-20Z OR BE CONFINED TO THE SOUTHEAST CORNER OF THE FORECAST AREA. HAVE NON-DIURNAL TEMPERATURE TREND MENTIONED ACROSS THE NORTH AS SHOULD SEE THE CAA DEVELOP LATE THIS MORNING AND INCREASE THROUGH THE AFTERNOON. 850MB TEMPS DROP TO +4C TO +6C BY 18Z IN THE NORTH. GUSTY NORTH TO NORTHWEST WINDS BEHIND THE FRONT WITH WINDS ATOP THE MIXED LAYER INCREASING TO AROUND 25 TO 30 KNOTS. MUCH DRIER AIR MASS FILTERS INTO THE STATE AS WELL WITH SURFACE DEW POINTS DROPPING INTO UPPER 30S AND LOWER 40S OVER THE NORTHWEST. RH VALUES DECREASE TO NEAR 25 PERCENT ACROSS A SMALL WESTERN PORTION OF FORECAST AREA. THOUGH AN INCREASED FIRE WEATHER DANGER TODAY...HELD OFF ON RED FLAG WARNING DUE TO CRITERIA NOT BEING MET WIDESPREAD. .LONG TERM /TONIGHT THROUGH SATURDAY/... ISSUED AT 343 AM CDT MON APR 21 2014 EARLY IN THE PERIOD...FEW CONCERNS. SYSTEM ON THE WAY OUT BY 00Z TONIGHT WITH SECONDARY COLD FRONT NOW OVER NORTHERN MN DROPPING SOUTHEAST ACROSS THE REGION TONIGHT...BRINGING DRIER AND COOLER AIR INTO THE REGION BY MORNING. DESPITE WARM TEMPS THE PAST FEW DAYS... MORNING LOWS TONIGHT WILL BE MUCH COOLER WITH MID 30S NORTH TO MID 40S SOUTH. TUESDAY LOOKS LIKE A NICE DAY WITH GENERALLY SUNNY SKIES AND A FEW FAIR WX CUMULUS DURING THE MID AFTERNOON AS HIGH PRESSURE DROPS SOUTHEAST THROUGH THE DAY...KEEPING WINDS LIGHT. LITTLE MIXING TO PROMOTE MUCH WARMING OTHER THAN SUNSHINE...SO WILL STICK WITH HIGHS IN THE UPPER 50S NORTHEAST AND MID 60S ACROSS THE WEST. MODELS DIFFER SLIGHTLY ON TIMING OF UPSTREAM WAVE AND EXPECTED WARM AIR ADVECTION/CLOUDS AND APPROACHING SHOWERS FOR WED. OVERALL...INCREASE IN CLOUDS EXPECTED LATE DAY WEST TUESDAY WITH SHOWERS NEARING THE WESTERN BORDER BY 12Z. THOUGH THUNDER MORE LIKELY ACROSS THE HIGH PLAINS AND NE...DRY AIR OVER IOWA WILL COOL AND DIMINISH INSTABILITY WHEN INITIAL PUSH OF MOISTURE ARRIVES. MODELS SHOW LITTLE INSTABILITY UNTIL AFTERNOON WED AND THAT AGAIN IS LESS THAN YESTERDAYS SOLUTIONS. THUS...HAVE TRIMMED AREAL COVERAGE OF THUNDER TO ISO WEST IN THE MORNING AND ISO EAST/SCT FAR WEST IN THE PM HOURS WEDNESDAY WITH THE FIRST REAL SURGE OF THETAE ADVECTION. AS THE SYSTEM CROSSES THE REGION...CONFIDENCE IN EVOLUTION OF SYSTEM HAS LESSENED SLIGHTLY. MODELS CONTINUE TO HAVE GENERAL TRENDS SIMILAR... BUT DETAILS DIFFER. OVERALL THE BETTER INSTABILITY WILL REMAIN WEST OF THE AREA UNTIL NEARER 00Z THUR...THEN WEAKEN OVERNIGHT PRIOR TO INCREASING AGAIN FROM LATE MORNING THUR THROUGH 00Z FRI. STILL SOME CONCERNS ABOUT OVERNIGHT CONVECTION ACROSS SOUTH/CENTRAL SECTIONS WED NIGHT AS SOME BULK SHEAR COULD AID SVR POTENTIAL. BOTH THE 00Z GFS AND THE 12Z/NEW 00Z EURO NOW SUGGEST THAT THE LOW WILL TRACK NORTHEAST ACROSS IA NEARLY EXITING OUR FORECAST AREA BY 18Z THUR...KEEPING THE BEST INSTABILITY AND SVR POTENTIAL EAST OF THE AREA BY THURSDAY AFTERNOON. FOR NOW...WILL CONTINUE TO MONITOR POTENTIAL BUT OVERALL CHANCES WOULD REMAIN CONDITIONAL ON ANY BETTER ALIGNMENT OF FORCING AND STRONGER INSTABILITY THURSDAY. BEYOND THUR AFTERNOON...MORE UNCERTAINTY IS ARISING IN THE REMAINDER OF THE FORECAST. MODELS HANDLING THE DEPARTURE OF THE SYSTEM WITH DIFFERING SPEED THUR NIGHT AND FRIDAY DUE TO A SECONDARY H500 SYSTEM OVER CENTRAL CANADA POTENTIALLY PHASING WITH THE DEPARTING H500 LOW. BOTH THE GEM/EURO TAKE THE FIRST SYSTEM EAST QUICKLY ENOUGH TO PREVENT MUCH PHASING WHILE THE GFS HOLDS ON TO A TROUGH EXTENDING WEST INTO MN. THIS RESULTS IN A FARTHER WEST RIDGE AXIS OVER CANADA THAT DROPS SOUTH INTO THE NORTHERN PLAINS AND DRIVES THE JET STREAM FARTHER SOUTH...DIRECTLY NEXT WEEKENDS STORM SOUTH OF IOWA. THE GEM/EURO SHOW ONLY A SLIGHT DELAY IN TIMING AND STILL BRING RAIN BACK INTO THE AREA FOR THE WEEKEND. FOR NOW THE GFS SHOWS TOO DRASTIC A CHANGE FOR SUCH A SMALL H500 FEATURE. DUE TO UNCERTAINTY...WILL CUT BACK ON POP CHANCE AT ONSET OF PRECIP EVENT NEXT SATURDAY BUT WILL STILL KEEP POP INCREASING WITH TIME THROUGH SUNDAY. TEMPS WILL HAVE EVEN GREATER UNCERTAINTY NOW...AS TIED TO CHANGES IN EVOLUTION AND TRACK OF WEEKEND UPPER AIR PATTERN AND STORM TRACK. NEWEST 21/00Z EURO STILL KEEPS TREND OF WET WEATHER NEXT WEEKEND...WHILE THE GFS REMAINS DRY. OVERALL THE EURO TENDS TO PERFORM MORE CONSISTENTLY AFTER FCST 120 HOURS SO WILL LEAN TOWARD GEM/EURO SOLUTIONS OF WETTER WEATHER SAT/SUN. AS MENTIONED IN PREVIOUS NIGHTS AFDS...THERE IS A CONSISTENT SIGNAL OF ENERGY STRETCHING FROM THE NORTH CENTRAL PACIFIC EAST TO THE PLAINS...WHICH WOULD FAVOR INCLEMENT WEATHER HERE. && .AVIATION...21/06Z ISSUED AT 1129 PM CDT SUN APR 20 2014 SHRA AND TSRA HAVE FORMED NEAR BOUNDARY ACROSS NORTHERN IOWA AND WILL CONTINUE TO AFFECT NORTHERN SITES KMCW/KALO/KFOD BEFORE SLOWLY PUSHING SOUTH OVERNIGHT...REACHING KDSM NEAR 12Z AND KOTM AFTER. CEILINGS AND VISIBILITIES WILL REMAIN PRIMARILY VFR...THOUGH MAY BRIEFLY DROP TO MVFR OR LOWER WITH TSRA. WINDS WILL BE FROM THE SOUTHWEST AHEAD OF BOUNDARY...MORE VARIABLE NEAR BOUNDARY AND FROM THE NORTHWEST BEHIND BOUNDARY. WINDS WILL ALSO BECOME GUSTY DURING THE DAY MONDAY BEFORE DIMINISHING NEAR SUNSET. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...AWB
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1205 PM CDT Mon Apr 21 2014 ...UPDATE TO AVIATION... .SYNOPSIS... ISSUED AT 950 AM CDT MON APR 21 2014 Water vapor imagery and 12Z upper air analysis indicate an upper level shortwave trough transitioning eastward across the Central Plains. Meanwhile, upper level ridging is shifting eastward across the Intermountain West. Near the surface, a weak cold front extends from southeastern Colorado northeast across west central Kansas into southeastern Nebraska. High pressure is building behind the front across the Colorado Rockies. && .SHORT TERM...(Today and tonight) ISSUED AT 317 AM CDT MON APR 21 2014 The main shortwave trough is depicted by the models to move into eastern Kansas this morning. The RUC model has picked up on the MCV over central Kansas and moves it southward into northwest Oklahoma today in the northwesterly flow on the backside of the trough. Model soundings show instability around 600-800 j/kg of CAPE as a mid level cold pool moves southeast across western Kansas today. Given the forcing with the MCV and a nearly uncapped sounding profile this afternoon over south central Kansas, will add some slight chance pops for showers and isolated thunder to the forecast. Things will quiet down fairly quickly late this afternoon and early evening as a ridge of surface high pressure moves east through the High Plains. Winds will become light and variable in the evening and gradually swing around to the southeast and south. Overnight lows will be the coolest over central Kansas where low to mid 40s are expected. Lows will drop into the upper 40s to around 50 along the Colorado border where increasing southerly winds will help keep temperatures up a few degrees more. .LONG TERM...(Tuesday through Sunday) ISSUED AT 414 AM CDT MON APR 21 2014 An upper ridge will be transitioning eastward across the Great Plains on Tuesday. Surface pressure falls along the lee of the Rockies and the retreating surface high pressure across the Missouri valley will create a moisture transport zone over the central High Plains, effectively causing an increasing in surface and 850 mb dew points across western and central Kansas. Afternoon heating across the higher terrain around the Palmer Divide will allow thunderstorms to form and be steered eastward into this moisture and instability axis. Some thunderstorms could move into western Kansas through the evening hours most likely around Syracuse. With a lack of dynamics, convection should be mainly diurnally driven, and as a result dry weather is likely through the overnight Tuesday into Wednesday morning with mild lows. An upper wave will be approaching the region Wednesday with several impacts. A decent surface pressure gradient will be in place as much drier air mixes out eastward though the morning and afternoon. The overall momentum transfer will probably be negatively influenced by mid level cloud decks indicated on model soundings and may even prevent a high wind event given 0-1 km mean winds on the order of 35-40 knots. Additionally a set up for severe storms will exist along and ahead of the dryline as the atmosphere destabilizes through the morning. Potential for rotating supercells exist with NAM model suggesting around 2-3 m2/s2 EHI(3km) with up to round 2000 J/kg of surface based CAPE ahead of the dryline feature. Good subsidence should follow in behind this dryline overnight into Thursday morning. Dry and warm conditions will likely follow into Friday as the next flat upper ridge settle across the region. Additional thunderstorm chances are in the forecast later in the weekend and early nextweek associated with yet another west coast jet carving a trough into the southern Rockies by the GFS and ECMWF. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) ISSUED AT 1203 PM CDT MON APR 21 2014 VFR conditions will prevail at all TAF sites through early Tuesday morning. Northeasterly winds of 15 to 25kt will continue through late this afternoon behind a weak cold front pushing southeast across south central Kansas into Oklahoma. Winds will then subside this evening while becoming more easterly as surface high pressure moves from the Colorado Rockies into the Western High Plains. Southerly winds of 10 to 20kt will develop early Tuesday morning as the surface high shifts further east into eastern Kansas. && .FIRE WEATHER... ISSUED AT 414 AM CDT MON APR 21 2014 Elevated fire danger is expected for Tuesday as breezy southerly winds and dew points in the 20s prevail through the day. A more significant risk is expected Wednesday as a dryline moves as far east as highway 283 by afternoon with strong gusty surface winds. Fire weather watches and eventually red flag warnings may be issued in the coming forecast shifts especially for areas west of Highway 83 for Wednesday. && .PRELIMINARY POINT TEMPS/POPS... DDC 76 45 80 56 / 10 0 0 10 GCK 75 45 82 57 / 10 0 10 10 EHA 74 50 83 58 / 10 0 10 10 LBL 76 48 83 58 / 10 0 0 10 HYS 75 43 75 56 / 80 0 10 20 P28 76 47 78 55 / 30 0 0 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JJohnson SHORT TERM...Gerard LONG TERM...Russell AVIATION...JJohnson FIRE WEATHER...Russell
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
952 AM CDT Mon Apr 21 2014 ...UPDATE TO SYNOPSIS... .SYNOPSIS... ISSUED AT 950 AM CDT MON APR 21 2014 Water vapor imagery and 12Z upper air analysis indicate an upper level shortwave trough transitioning eastward across the Central Plains. Meanwhile, upper level ridging is shifting eastward across the Intermountain West. Near the surface, a weak cold front extends from southeastern Colorado northeast across west central Kansas into southeastern Nebraska. High pressure is building behind the front across the Colorado Rockies. && .SHORT TERM...(Today and tonight) ISSUED AT 317 AM CDT MON APR 21 2014 The main shortwave trough is depicted by the models to move into eastern Kansas this morning. The RUC model has picked up on the MCV over central Kansas and moves it southward into northwest Oklahoma today in the northwesterly flow on the backside of the trough. Model soundings show instability around 600-800 j/kg of CAPE as a mid level cold pool moves southeast across western Kansas today. Given the forcing with the MCV and a nearly uncapped sounding profile this afternoon over south central Kansas, will add some slight chance pops for showers and isolated thunder to the forecast. Things will quiet down fairly quickly late this afternoon and early evening as a ridge of surface high pressure moves east through the High Plains. Winds will become light and variable in the evening and gradually swing around to the southeast and south. Overnight lows will be the coolest over central Kansas where low to mid 40s are expected. Lows will drop into the upper 40s to around 50 along the Colorado border where increasing southerly winds will help keep temperatures up a few degrees more. .LONG TERM...(Tuesday through Sunday) ISSUED AT 414 AM CDT MON APR 21 2014 An upper ridge will be transitioning eastward across the Great Plains on Tuesday. Surface pressure falls along the lee of the Rockies and the retreating surface high pressure across the Missouri valley will create a moisture transport zone over the central High Plains, effectively causing an increasing in surface and 850 mb dew points across western and central Kansas. Afternoon heating across the higher terrain around the Palmer Divide will allow thunderstorms to form and be steered eastward into this moisture and instability axis. Some thunderstorms could move into western Kansas through the evening hours most likely around Syracuse. With a lack of dynamics, convection should be mainly diurnally driven, and as a result dry weather is likely through the overnight Tuesday into Wednesday morning with mild lows. An upper wave will be approaching the region Wednesday with several impacts. A decent surface pressure gradient will be in place as much drier air mixes out eastward though the morning and afternoon. The overall momentum transfer will probably be negatively influenced by mid level cloud decks indicated on model soundings and may even prevent a high wind event given 0-1 km mean winds on the order of 35-40 knots. Additionally a set up for severe storms will exist along and ahead of the dryline as the atmosphere destabilizes through the morning. Potential for rotating supercells exist with NAM model suggesting around 2-3 m2/s2 EHI(3km) with up to round 2000 J/kg of surface based CAPE ahead of the dryline feature. Good subsidence should follow in behind this dryline overnight into Thursday morning. Dry and warm conditions will likely follow into Friday as the next flat upper ridge settle across the region. Additional thunderstorm chances are in the forecast later in the weekend and early nextweek associated with yet another west coast jet carving a trough into the southern Rockies by the GFS and ECMWF. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) ISSUED AT 1257 AM CDT MON APR 21 2014 Low level moisture advecting up into southwest Kansas could result in 2-4 miles in mist along with IFR stratus. There is some uncertainty as to how widespread it will become. For now will have a tempo group for lower visibility at Garden City and Dodge City early this morning with conditions improving to VFR between 10 and 12z. A cold front will move through around sunrise and sweep the low level moisture out of the area. By this afternoon, some instability showers could develop in the area around and east of Dodge City and have added VCSH to the Dodge City TAF for this. && .FIRE WEATHER... ISSUED AT 414 AM CDT MON APR 21 2014 Elevated fire danger is expected for Tuesday as breezy southerly winds and dew points in the 20s prevail through the day. A more significant risk is expected Wednesday as a dryline moves as far east as highway 283 by afternoon with strong gusty surface winds. Fire weather watches and eventually red flag warningS may be issued in the coming forecast shifts especially for areas west of Highway 83 for Wednesday. && .PRELIMINARY POINT TEMPS/POPS... DDC 76 45 80 56 / 10 0 0 10 GCK 75 45 82 57 / 10 0 10 10 EHA 74 50 85 57 / 10 0 10 10 LBL 76 48 85 57 / 10 0 0 10 HYS 75 43 80 55 / 80 0 10 20 P28 76 47 80 54 / 30 0 0 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JJohnson SHORT TERM...Gerard LONG TERM...Russell AVIATION...Gerard FIRE WEATHER...Russell
AREA FORECAST DISCUSSION...corrected
NWS DODGE CITY KS
415 AM CDT Mon Apr 21 2014 ...UDATED LONG TERM AND FIRE WEATHER SECTIONS... .SHORT TERM...(Today and tonight) ISSUED AT 317 AM CDT MON APR 21 2014 The main shortwave trough is depicted by the models to move into eastern Kansas this morning. The RUC model has picked up on the MCV over central Kansas and moves it southward into northwest Oklahoma today in the northwesterly flow on the backside of the trough. Model soundings show instability around 600-800 j/kg of CAPE as a mid level cold pool moves southeast across western Kansas today. Given the forcing with the MCV and a nearly uncapped sounding profile this afternoon over south central Kansas, will add some slight chance pops for showers and isolated thunder to the forecast. Things will quiet down fairly quickly late this afternoon and early evening as a ridge of surface high pressure moves east through the High Plains. Winds will become light and variable in the evening and gradually swing around to the southeast and south. Overnight lows will be the coolest over central Kansas where low to mid 40s are expected. Lows will drop into the upper 40s to around 50 along the Colorado border where increasing southerly winds will help keep temperatures up a few degrees more. .LONG TERM...(Tuesday through Sunday) ISSUED AT 414 AM CDT MON APR 21 2014 An upper ridge will be transitioning eastward across the Great Plains on Tuesday. Surface pressure falls along the lee of the Rockies and the retreating surface high pressure across the Missouri valley will create a moisture transport zone over the central High Plains, effectively causing an increasing in surface and 850 mb dew points across western and central Kansas. Afternoon heating across the higher terrain around the Palmer Divide will allow thunderstorms to form and be steered eastward into this moisture and instability axis. Some thunderstorms could move into western Kansas through the evening hours most likely around Syracuse. With a lack of dynamics, convection should be mainly diurnally driven, and as a result dry weather is likely through the overnight Tuesday into Wednesday morning with mild lows. An upper wave will be approaching the region Wednesday with several impacts. A decent surface pressure gradient will be in place as much drier air mixes out eastward though the morning and afternoon. The overall momentum transfer will probably be negatively influenced by mid level cloud decks indicated on model soundings and may even prevent a high wind event given 0-1 km mean winds on the order of 35-40 knots. Additionally a set up for severe storms will exist along and ahead of the dryline as the atmosphere destabilizes through the morning. Potential for rotating supercells exist with NAM model suggesting around 2-3 m2/s2 EHI(3km) with up to round 2000 J/kg of surface based CAPE ahead of the dryline feature. Good subsidence should follow in behind this dryline overnight into Thursday morning. Dry and warm conditions will likely follow into Friday as the next flat upper ridge settle across the region. Additional thunderstorm chances are in the forecast later in the weekend and early nextweek associated with yet another west coast jet carving a trough into the southern Rockies by the GFS and ECMWF. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) ISSUED AT 1257 AM CDT MON APR 21 2014 Low level moisture advecting up into southwest Kansas could result in 2-4 miles in mist along with IFR stratus. There is some uncertainty as to how widespread it will become. For now will have a tempo group for lower visibility at Garden City and Dodge City early this morning with conditions improving to VFR between 10 and 12z. A cold front will move through around sunrise and sweep the low level moisture out of the area. By this afternoon, some instability showers could develop in the area around and east of Dodge City and have added VCSH to the Dodge City TAF for this. && .FIRE WEATHER... ISSUED AT 414 AM CDT MON APR 21 2014 Elevated fire danger is expected for Tuesday as breezy southerly winds and dew points in the 20s prevail through the day. A more significant risk is expected Wednesday as a dryline moves as far east as highway 283 by afternoon with strong gusty surface winds. Fire weather watches and eventually red flag warningS may be issued in the coming forecast shifts especially for areas west of Highway 83 for Wednesday. && .PRELIMINARY POINT TEMPS/POPS... DDC 76 44 79 56 / 10 0 10 20 GCK 75 44 82 57 / 0 0 10 10 EHA 74 50 83 57 / 0 0 10 10 LBL 76 46 83 57 / 0 0 10 10 HYS 75 42 79 55 / 10 0 10 20 P28 76 46 79 54 / 20 0 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Gerard LONG TERM...Russell AVIATION...Gerard FIRE WEATHER...Russell
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
318 AM CDT Mon Apr 21 2014 ...Updated synopsis and short term discussion... .SYNOPSIS... ISSUED AT 317 AM CDT MON APR 21 2014 The 00z upper air analysis showed a shortwave trough extending from southern Nebraska across southwest Kansas into the Texas Panhandle. With fairly light steering flow aloft, this trough was slowly moving eastward through the High Plains this morning. Thunderstorms over central and western Kansas that had fired up Sunday afternoon had pretty much dissipated early this morning. There were a few showers over central Kansas around Hays and Lacrosse which were associated with an MCV leftover from the thunderstorm complex earlier in the evening. && .SHORT TERM...(Today and tonight) ISSUED AT 317 AM CDT MON APR 21 2014 The main shortwave trough is depicted by the models to move into eastern Kansas this morning. The RUC model has picked up on the MCV over central Kansas and moves it southward into northwest Oklahoma today in the northwesterly flow on the backside of the trough. Model soundings show instability around 600-800 j/kg of CAPE as a mid level cold pool moves southeast across western Kansas today. Given the forcing with the MCV and a nearly uncapped sounding profile this afternoon over south central Kansas, will add some slight chance pops for showers and isolated thunder to the forecast. Things will quiet down fairly quickly late this afternoon and early evening as a ridge of surface high pressure moves east through the High Plains. Winds will become light and variable in the evening and gradually swing around to the southeast and south. Overnight lows will be the coolest over central Kansas where low to mid 40s are expected. Lows will drop into the upper 40s to around 50 along the Colorado border where increasing southerly winds will help keep temperatures up a few degrees more. .LONG TERM...(Monday night through Sunday) ISSUED AT 149 PM CDT SUN APR 20 2014 Upper level ridging builds over the Plains Monday night through Tuesday with dry conditions in the mid levels. This will allow mostly clear skies to be observed across western Kansas. This will be short lived as the next storm system moves into the Northern Rockies Tuesday night into Wednesday. Southerly winds will be felt across western Kansas as this system approaches with increasing mid level moisture Tuesday night. A moderate upper level jet will be found above western Kansas on Wednesday enhancing lift across the area. Southerly winds will continue at the surface becoming windy in the afternoon. In addition, a dryline is suggested to develop in the afternoon with CAPE and shear increasing as the day progresses. These conditions will bring a chance of thunderstorms ahead of the dryline from late afternoon into Wednesday night. A few of these storms could become strong to severe with large hail and damaging winds being the main concern. A cold front then moves through western Kansas Thursday morning shifting winds to the north. Lows Tuesday morning will be in the low to mid 40s with highs Tuesday reaching into the upper 70s and lower 80s. The warmest day of the week looks to be on Wednesday with lows in the mid 50s and highs in the lower 80s. Lows Thursday morning look to range from the mid 40s across west central Kansas where the aforementioned cold front is expected to move through early to upper 50s across south central Kansas where the front is not expected to move through by sunrise. Dry conditions are then expected during the remainder of the week as an upper level ridge builds above the Plains with dry conditions in the mid levels. Winds shift back to the south by Saturday as the next storm system entered the western United States. This system is expected to affect western Kansas this weekend bringing an increase in clouds and a chance of thunderstorms. Highs Thursday through this weekend will generally be in the 70s with lower 80s possible across far southwestern Kansas on Saturday. Lows will generally be in the mid to upper 40s Friday and Saturday morning. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) ISSUED AT 1257 AM CDT MON APR 21 2014 Low level moisture advecting up into southwest Kansas could result in 2-4 miles in mist along with IFR stratus. There is some uncertainty as to how widespread it will become. For now will have a tempo group for lower visibility at Garden City and Dodge City early this morning with conditions improving to VFR between 10 and 12z. A cold front will move through around sunrise and sweep the low level moisture out of the area. By this afternoon, some instability showers could develop in the area around and east of Dodge City and have added VCSH to the Dodge City TAF for this. && .PRELIMINARY POINT TEMPS/POPS... DDC 76 44 79 56 / 10 0 10 20 GCK 75 44 82 57 / 0 0 10 10 EHA 74 50 83 57 / 0 0 10 10 LBL 76 46 83 57 / 0 0 10 10 HYS 75 42 79 55 / 10 0 10 20 P28 76 46 79 54 / 20 0 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Gerard SHORT TERM...Gerard LONG TERM...Hovorka_42 AVIATION...Gerard
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1257 AM CDT Mon Apr 21 2014 ...Updated aviation discussion... .SHORT TERM...(This evening through Monday) ISSUED AT 116 PM CDT SUN APR 20 2014 Ample insolation early this afternoon resulted in surface-based CAPE in the 700-1100 J/kg west of Highway 283 to the Colorado border. Lack of a capping inversion beneath cool temperatures in the 700-500mb layer (+2C at 700mb). There were two areas of surface convergence that will support development of thunderstorms by mid-afternoon. The first area is near the Colorado border along the stationary trough axis, which is also near where the mid level vorticity center is. We are also watching a secondary area of interest from Dodge City south to the Oklahoma border where surface wind convergence was slightly enhanced. 1km visible satellite confirmed development of cumulus in both of these areas. Given the higher degree of instability than earlier anticipated, a few hail storms may occur with the largest hail most likely being around 1-inch in diameter (Quarter size). Severe weather threat will likely wane after 00Z or so as showers and thunderstorms grow upscale. This is what the HRRR would seem to suggest in its latest runs, which makes sense given the marginal instability. Much of the precipitation should be coming to an end/or exiting the southwest Kansas region in the 04-07Z time frame so POPs will be lowered during this time frame and shortly thereafter. A northern stream shortwave trough will aid in bringing a cold front south through western Nebraska late tonight, reaching southwestern Kansas by mid to late morning Monday. The front is not expected to have any impact on temperatures, though, so the going forecast of upper 70s to near 80 still looks pretty good (especially along/south of the Arkansas River). .LONG TERM...(Monday night through Sunday) ISSUED AT 149 PM CDT SUN APR 20 2014 Upper level ridging builds over the Plains Monday night through Tuesday with dry conditions in the mid levels. This will allow mostly clear skies to be observed across western Kansas. This will be short lived as the next storm system moves into the Northern Rockies Tuesday night into Wednesday. Southerly winds will be felt across western Kansas as this system approaches with increasing mid level moisture Tuesday night. A moderate upper level jet will be found above western Kansas on Wednesday enhancing lift across the area. Southerly winds will continue at the surface becoming windy in the afternoon. In addition, a dryline is suggested to develop in the afternoon with CAPE and shear increasing as the day progresses. These conditions will bring a chance of thunderstorms ahead of the dryline from late afternoon into Wednesday night. A few of these storms could become strong to severe with large hail and damaging winds being the main concern. A cold front then moves through western Kansas Thursday morning shifting winds to the north. Lows Tuesday morning will be in the low to mid 40s with highs Tuesday reaching into the upper 70s and lower 80s. The warmest day of the week looks to be on Wednesday with lows in the mid 50s and highs in the lower 80s. Lows Thursday morning look to range from the mid 40s across west central Kansas where the aforementioned cold front is expected to move through early to upper 50s across south central Kansas where the front is not expected to move through by sunrise. Dry conditions are then expected during the remainder of the week as an upper level ridge builds above the Plains with dry conditions in the mid levels. Winds shift back to the south by Saturday as the next storm system entered the western United States. This system is expected to affect western Kansas this weekend bringing an increase in clouds and a chance of thunderstorms. Highs Thursday through this weekend will generally be in the 70s with lower 80s possible across far southwestern Kansas on Saturday. Lows will generally be in the mid to upper 40s Friday and Saturday morning. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) ISSUED AT 1257 AM CDT MON APR 21 2014 Low level moisture advecting up into southwest Kansas could result in 2-4 miles in mist along with IFR stratus. There is some uncertainty as to how widespread it will become. For now will have a tempo group for lower visibility at Garden City and Dodge City early this morning with conditions improving to VFR between 10 and 12z. A cold front will move through around sunrise and sweep the low level moisture out of the area. By this afternoon, some instability showers could develop in the area around and east of Dodge City and have added VCSH to the Dodge City TAF for this. && .PRELIMINARY POINT TEMPS/POPS... DDC 45 79 56 84 / 0 10 20 40 GCK 43 82 57 83 / 0 10 10 30 EHA 46 83 57 84 / 0 10 10 20 LBL 46 83 57 85 / 0 10 10 30 HYS 43 79 55 82 / 0 10 20 50 P28 47 79 54 82 / 0 10 10 50 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Umscheid LONG TERM...Hovorka_42 AVIATION...Gerard
AREA FORECAST DISCUSSION
NWS PADUCAH KY
302 PM CDT Mon Apr 21 2014 .SHORT TERM...(Tonight through Wednesday night) Issued at 301 PM CDT MON APR 21 2014 Radar has been showing light showers and sprinkles across parts of the area all day, with the greatest concentration over southeast Missouri and southwest IN. It it fairly dry in the lowest levels in some places across the east, and sprinkles were noted in those areas. Cold front is still poised well off to our west and will continue making eastward progress later today and tonight. Short term models have not done well with the ongoing precipitation. The HRRR did pretty well early on but now the RAP models seems to be doing ok. As the front approaches and until its departure, we will continue to have scattered convection. The problem will be where and when to place the best POPS as lift with this system is not too strong. Will maintain at least scattered to likely wording for now. With all the cloud cover, instability has been hard to come by, but new thunderstorms are forming over northern Arkansas this afternoon, which have some hope of moving into parts of the area. Showers should quickly taper off from northwest to southeast between 05z and 10z Tuesday, with just a few showers possibly lingering in our far southeast counties early Tuesday morning. High pressure will build over the upper Mississippi valley Tuesday, sliding slowly east over the Great Lakes region by Wednesday. Winds out of the north on Tuesday will gradually shift to the east by Wednesday, which will help give us cooler, near seasonal conditions, as 900 mb temps drop back down into the single digits. The region should see quite a bit of sunshine by Tuesday afternoon and again on Wednesday with dry air in place over the area. Clouds will increase late Wednesday night with increasing moisture ahead of our next weather system. .LONG TERM...(Thursday through Monday) Issued at 301 PM CDT MON APR 21 2014 The 12Z models are in fairly good agreement in bringing the southern end of a mid/upper level trough eastward through the area, with a cold front, Thursday afternoon and evening. The upper system is negatively tilted, so there should be enough forcing to overcome very meager instability and create a band of showers and thunderstorms near the front. Wind fields will be pretty good, but instability is lacking, so would not expect much of a severe threat. A stray strong storm cannot be ruled out, though. given the speed of the system, would not expect much of a heavy rain threat either. The cold front Thursday is quite weak, so temperatures will still be well into the 70s for highs on Friday with plenty of sunshine. However, all bets are off beginning Friday night, as the models diverge significantly in the details for our region. The GFS is the most amplified in developing a Omega blocking pattern centered on our region. It is particularly strong with its eastern trough, and pushes a significant cold front through the area Friday night and Saturday morning. This should be a dry frontal passage. The GFS ends up with a very skinny ridge running northward right through our region. This would keep the eastern half of the area under the influence of the cool surface high and precipitation free over the weekend. The question would be how much convective activity would slip southeast over our western areas from Saturday night on through Monday. The ECMWF is quite a bit less amplified with the east coast trough, and has varied considerably with the southward push of the cold front. The 12Z version stalls the east-west oriented front right through our region, and has a rather wet forecast from Saturday night through at least Monday. The GFS looks too amplified, but the ECMWF has not been very consistent in its frontal/precipitation details. Will have small pops mainly in the west Saturday night and Sunday, and then just broad brush 30 to 40 PoPs for Sunday night through Monday night. Temperatures will be tricky given the different synoptic possibilities, but in general, they should be at or above normal through Sunday and then fall below normal for Monday. && .AVIATION... Issued at 1230 PM CDT MON APR 21 2014 Scattered showers continue across southeast Missouri and are working their way northeast. Additional showers are also trying to develop over southwest IN. A front is poised well off to our west...and the atmosphere will continue to moisten up in the lower levels. Scattered rain showers and possible thunderstorms will be possible for the rest of the afternoon. Tried to time the best chances for precipitation near/along the front late this afternoon and early this evening. Precip will shut off/move east of the area later tonight and with the front passage will come a wind shift as well. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ SHORT TERM...DRS LONG TERM...CW
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1156 PM EDT TUE APR 22 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 416 PM EDT TUE APR 22 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE ALONG THE W COAST OF THE CONUS. JUST DOWNSTREAM OF THE TROF...A SHARP RIDGE ALIGNED ALONG THE LEE OF THE ROCKIES IS ALLOWING FOR TROF AMPLIFICATION INTO THE GREAT LAKES...LED BY SHORTWAVE THAT WAS PASSING JUST N OF LAKE SUPERIOR 24HRS AGO. PER 12Z RAOBS AND LATEST RUC ANALYSIS...850MB THERMAL TROF IS CURRENTLY CENTERED OVER CNTRL LAKE SUPERIOR/CNTRL UPPER MI. AS A RESULT...CLOUD COVER HAS BEEN SLOW TO CLEAR THIS AFTN. TRAILING SHORTWAVE THAT IS CURRENTLY DROPPING SE THRU WRN UPPER MI/NRN LAKE MICHIGAN IS ALSO AIDING THE CLOUD COVER AND HAS ALSO GENERATED FLURRIES/-SHSN THIS AFTN. FLURRIES/-SHSN HAVE ENDED ON THE KEWEENAW AND WILL QUICKLY EXIT THE REST OF THE FCST AREA IN THE NEXT 2-3HRS. AS WOULD BE EXPECTED UNDER THE THERMAL TROF AND WITH ABUNDANT CLOUD COVER...TEMPS HAVE STUGGLED TO RISE TODAY. MID AFTN READINGS ARE IN THE 30S ACROSS MUCH OF UPPER MI (LOW 30S AT SOME LOCATIONS) TO THE LOW/MID 40S SCNTRL AND NEAR KIWD. CLEARING IS NOW GETTING UNDERWAY ACROSS LAKE SUPERIOR...ESPECIALLY THE W HALF. SKIES WILL CLEAR ACROSS THE BOARD DURING THE EVENING AS MUCH DRIER AIR CONTINUES TO SPREAD INTO THE AREA FROM THE N AND W...BUT CLOUDS WILL HANG ON LONGEST OVER THE E AS THERE IS STILL AN AXIS OF MOISTURE/CLOUDS EXTENDING BACK TOWARD LAKE NIPIGON. AFTER A CHILLY DAY...CLEAR SKIES WITH WINDS DIMINISHING TO LIGHT/CALM AS SFC HIGH PRES RIDGE AXIS SETTLES OVER WRN UPPER MI DURING THE NIGHT WILL SET THE STAGE FOR A COLD NIGHT. DRY AIR MASS WITH PRECIPITABLE WATER IN THE 40-50PCT RANGE WILL ENHANCE RADIATIONAL COOLING. WILL GO AT OR BLO LOWEST GUIDANCE...ESPECIALLY WHERE MEANINGFUL SNOWCOVER STILL EXITS. TRADIATIONAL COLDS SPOTS WILL LIKELY FALL INTO THE TEENS... BUT 20S WILL GENERALLY BE THE RULE. RECORD LOW FOR NWS MQT FOR APR 23 IS 17F. MIGHT BE CLOSE TO THAT. ON WED...ABUNDANT SUNSHINE TO START THE DAY WILL GIVE WAY TO INCREASING HIGH CLOUDS FROM THE W. WITH SFC HIGH PRES RIDGE JUST DRIFTING E...MESOHIGH WILL SET UP OVER CNTRL AND ERN LAKE SUPERIOR DURING THE AFTN AND ALSO OVER LAKE MICHIGAN. AS A RESULT...LAKE BREEZES WILL DOMINATE...KEEPING LAKESIDE LOCATIONS CHILLY...PROBABLY 30S FOR MUCH OF THE DAY. DRY AIR MASS WILL AID DEEP MIXING POTENTIAL...SO AREAS WELL INLAND FROM THE LAKES WILL BE ABLE TO WARM NICELY AFTER THE COLD START. MIXING TO AROUND 800MB ON FCST SOUNDINGS SUGGESTS MAX TEMPS INTO THE MID 50S ALONG THE WI BORDER. WILL BE WARMER IF MIXING IS HIGHER. MIXING WILL ALSO RESULT IN DWPTS FALLING DURING THE AFTN. UTILIZED SOME OF THE DRYING POTENTIAL BASED ON MIXING HEIGHT TO LOWER DWPTS TO JUST UNDER 20F IN THE INTERIOR. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 447 PM EDT TUE APR 22 2014 THE BULK OF THE LONG TERM FORECAST DEALS WITH AN UPPER LEVEL TROUGH AND ASSOCIATED LOW PRESSURE SYSTEM THAT MOVES THROUGH THE GREAT LAKES REGION LATE WEDNESDAY NIGHT AND LIKELY CONTINUING INTO FRIDAY EVENING. THE UPPER TROUGH MOVING OVER THE WESTERN COAST OF THE PACIFIC NORTHWEST WILL BE THE FEATURE TO INFLUENCE THE AREA FOR THE END OF THIS WEEK. AS THIS SYSTEM CROSSES THE ROCKIES...A SURFACE LOW WILL DEVELOP IN THE LEE OF THE CANADIAN/NORTHERN ROCKIES AND SHIFT EAST INTO THE UPPER MISSISSIPPI VALLEY ON THURSDAY. HIGH PRESSURE THAT WILL BE OVER THE AREA TONIGHT AND WEDNESDAY WILL BE SLOWLY DEPARTING THE AREA WEDNESDAY NIGHT. THIS...COMBINED WITH A SLIGHTLY LATER ARRIVAL FROM THE UPPER TROUGH...WILL DELAY THE START OF THE PRECIPITATION LATER THAN EXPECTED 24 HOURS AGO AND GENERALLY MOVING IN DURING THE DAY ON THURSDAY. THERE ARE SEVERAL WAVES ASSOCIATED WITH THIS UPPER TROUGH...WHICH LEADS TO A DOUBLE BARREL LOW MOVING OUT OF THE NORTHERN/CENTRAL PLAINS ON WEDNESDAY NIGHT. WHILE PREVIOUS MODELS RUNS HAD THE IDEA OF THESE LOWS MERGING WHEN THE NORTHERN/SOUTHERN WAVES IN THE UPPER TROUGH COMING TOGETHER AND STRENGTHENING AS IT MOVES THROUGH NORTHERN LAKE MICHIGAN. BUT MOST OF THE 12Z MODEL RUNS (EXCEPT FOR THE GFS) HAS TRENDED TOWARDS THE LACK OF PHASING BETWEEN THOSE UPPER LEVEL WAVES. WITHOUT THIS PHASING...THE SOUTHERN STREAM WAVE WOULD SHIFT EAST THROUGH THE CENTRAL MISSISSIPPI VALLEY THURSDAY NIGHT AND JUST HAVE A BROAD LOW MOVING THROUGH THE AREA. WHILE THIS STILL BRING PRECIPITATION TO THE AREA...IT MAY HAVE SOME AFFECT ON THE AMOUNTS OVER PORTIONS OF THE AREA BEFORE THE NORTHERN STREAM WAVE ARRIVES THURSDAY NIGHT OVER THE UPPER GREAT LAKES. THE GREATEST AFFECT OF THIS SPLIT FEATURE IS FOR THE PRECIPITATION TO STEADILY SHIFT NORTHEAST AND GENERALLY OUT OF THE AREA FOR FRIDAY. IF THIS IS THE CASE...FLOW ALOFT WILL BE MORE WESTERLY ON FRIDAY...LEADING TO WARMER TEMPERATURES AND DRIER CONDITIONS THAN INITIALLY EXPECTED. ALTHOUGH THERE ARE STILL DIFFERENCES IN THE MODELS WITH THE EXACT HANDLING OF THE PHASING...IT STILL APPEARS THE MOST OF THE CWA WILL SEE 0.5 INCH OF QPF. THE HEAVIEST PRECIPITATION STILL APPEARS TO OCCUR OVER THE WESTERN HALF TO 2/3RDS OF THE U.P. AND EXPECT SOME LOCATIONS OVER THE WEST TO BE NEARING 1 INCH OF LIQUID EQUIVALENT. THE IMPACT FROM THIS EVENT AND THE ASSOCIATED 0.75-1.0 INCH OF QPF OVER THE WESTERN HALF OF THE CWA WILL DEPEND ON THE PRECIP TYPE FORECAST. ALTHOUGH THIS FORECAST HAS BEEN AND CONTINUES TO BE TRICKY...TRENDS IN THE MODELS ARE POINTING TOWARDS SNOW OVER AT LEAST THE NORTHWEST HALF OF UPPER MICHIGAN WITH THE WARMER AIR REMAINING HUNG UP TO THE SOUTH-SOUTHEAST OF THE AREA. IN ADDITION...WITH THE DRY AIR FROM THE HIGH TAKING LONGER TO DEPART...THE LOW LEVEL DRY AIR WILL AID EVAPORATIVE COOLING IN THE LOW LEVELS AS THE PRECIPITATION STARTS. THIS WOULD LEAD TO ABOVE FREEZING LAYERS ABOVE THE SURFACE TO COOL TO OR BELOW FREEZING AND HAVE A FEELING THE PRECIP TYPE WILL BE LARGELY SNOW INITIALLY OVER THE WEST (ESPECIALLY HIGHER TERRAIN). THE 12Z MODEL THERMAL FIELDS ARE STILL BORDERLINE FOR PRECIP TYPE HEADING THROUGH THURSDAY...BUT LOOKING AT SOUNDINGS THERE IS A NEARLY ISOTHERMAL LAYER BELOW 750MB AROUND OR BELOW FREEZING. THUS...HAVE TRENDED THE FORECAST TOWARDS A MORE SNOW THAN RAIN OVER THE NORTHWEST HALF. AT THIS TIME...THAT BEST OPPORTUNITY FOR A RAIN/SNOW MIX OR MORE RAIN WOULD BE ALONG THE WISCONSIN BORDER AND ALSO SOUTHEAST OF A LINE FROM IRON MOUNTAIN TO GWINN TO SENEY. ALTHOUGH THERE ARE SOME INDICATIONS IN THE COBB OUTPUT OF HIGHER SNOW RATIOS...WOULD EXPECT VALUES TO BE GENERALLY IN THE 8-10 TO 1 RANGE DUE TO THE AMOUNT OF FORCING BELOW THE DGZ. SINCE THE SNOW WILL START DURING THE DAY THURSDAY...IT IS DIFFICULT TO GET SIGNIFICANT ACCUMULATIONS TO OCCUR BEFORE DAYTIME HEATING IS LOST (ESPECIALLY ON ROADWAYS) AND HAVE LIMITED AMOUNTS DURING THE DAY TO A SLUSHY COUPLE INCHES OVER PORTIONS OF THE WEST. WITH THE COOLING AT NIGHT...SHOULD SEE ACCUMULATIONS INCREASE ON BOTH ROADS AND SNOW/GRASS COVERED SURFACES. AT THAT TIME...THE BEST QPF AND COLD AIR WILL BE OVER LAKE SUPERIOR AND AFFECTING THE KEWEENAW PENINSULA. HAVE THE HIGHEST AMOUNTS FORECASTED FOR THE KEWEENAW...WITH 6-9 INCHES BY 12Z FRIDAY. SOUTH AND EAST OF THERE ARE MORE UP IN THE AIR WITH THE RAIN POTENTIAL AND SLIGHTLY WARMER SURFACE TEMPERATURES...BUT STILL FEEL THERE COULD BE 2-6 INCHES OF SLUSHY ACCUMULATION. LOOKING AT THE 00Z ECMWF ENSEMBLE SNOWFALL...MORE THAN 50 PERCENT OF THE MEMBERS HAVE 24HR SNOWFALL AMOUNTS OF EXCEEDING 3 INCHES OVER THE NORTHWEST 2/3RDS OF THE CWA AND PROBS DECREASE TO 20-30 PERCENT OF 6 INCHES. WITH LOW CONFIDENCE ON WARNING AMOUNTS AT THIS POINT (AND THE IMPACTS ARE LARGELY IN THE 5TH PERIOD)...DIDN/T FEEL COMFORTABLE WITH ISSUING A WATCH AT THIS PERIOD. THEREFORE...HAVE ISSUED AN SPS FOR PORTIONS OF WESTERN UPPER MICHIGAN AND WILL ALLOW THE SHIFT TONIGHT TO SEE IF THE TRENDS FROM THE 12Z RUNS CONTINUE. BEHIND THE SYSTEM...MODELS ARE FAIRLY CONSISTENT ON A STRONG CANADIAN HIGH DEVELOPING IN THE PRAIRIES AND SHIFTING EAST TO HUDSON BAY EARLY NEXT WEEK. THAT WILL LEAD TO DRY NORTH-NORTHEASTERLY FLOW OVER THE AREA INTO THE FIRST HALF OF NEXT WEEK. THAT FLOW REGIME SHOULD KEEP TEMPERATURES BELOW NORMAL (POTENTIALLY NEARING RECORD LOW HIGH TEMPS AT OUR OFFICE) AND ANY PRECIP ASSOCIATED WITH THE UPPER TROUGH MOVING THROUGH THE CENTRAL/SOUTHERN PLAINS SOUTH OF THE AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1156 PM EDT TUE APR 22 2014 HIGH PRES AND ITS ASSOCIATED DRY AIRMASS WILL DOMINATE THROUGH THE PERIOD RESULTING IN LIGHT WINDS AND VFR CONDITIONS AT ALL TERMINALS. THERE WILL BE SOME INCREASE IN MID CLOUDS AT KIWD LATE IN THE PERIOD AS ANOTHER LOW PRES SYSTEM ADVANCES FROM THE PLAINS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 416 PM EDT TUE APR 22 2014 AS HIGH PRES RIDGE EXTENDING FROM MN SOUTHWARD SHIFTS TO WRN LAKE SUPERIOR/WRN UPPER MI TONIGHT...WINDS WILL CONTINUE TO DIMINISH FROM W TO E. WINDS ARE ALREADY LIGHT OVER THE WRN LAKE...AND THE INITIAL NW 20-30KT WINDS OVER ERN LAKE SUPERIOR WILL DROP TO UNDER 15KT TONIGHT. LIGHT WINDS WILL LINGER THRU WED AS HIGH PRES RIDGE SLOWLY DRIFTS E. HOWEVER...E WINDS WILL BEGIN TO INCREASE TOWARD 20KT OVER FAR WRN LAKE SUPERIOR IN THE AFTN. EASTERLY WINDS WILL THEN GRADUALLY INCREASE WED NIGHT AND WILL REACH 20-30KT ACROSS MUCH OF LAKE SUPERIOR THU IN ADVANCE OF LOW PRES APPROACHING THE WRN GREAT LAKES. DEPENDING ON THE EXACT TRACK AND INTENSITY OF THE LOW...NOT OUT OF THE QUESTION THAT THERE COULD BE SOME GALE FORCE WINDS OVER WESTERN LAKE SUPERIOR WHERE TERRAIN FUNNELING/COASTAL CONVERGENCE WOULD ENHANCE THIS E WIND. AS THE LOW SHIFTS TO THE E LATER ON FRI INTO SAT AHEAD OF HIGH PRES BUILDING INTO SCENTRAL CANADA...THE WIND WILL SHIFT TO THE N AND SLOWLY DIMINISH WITH THE CLOSER APPROACH OF THE HIGH ON SAT. BEST CHANCE FOR SOME GALES FRI INTO EARLY SAT WOULD BE OVER THE E HALF OF THE LAKE...AGAIN...DEPENDING ON INTENSITY OF THE LOW. && .HYDROLOGY... ISSUED AT 458 PM EDT TUE APR 22 2014 A MUCH COLDER DAY SEEN ACROSS UPPER MICHIGAN TODAY WHEN COMPARED TO YESTERDAY. THIS HAS LED TO REDUCED SNOWMELT WHICH WILL CONTINUE INTO WEDNESDAY...ALTHOUGH SOME RIVER LEVELS WILL LIKELY STILL BE ON THE RISE AS WATER WORKS THROUGH THE RIVER SYSTEMS. ALTHOUGH RATHER COOL TEMPERATURES WILL REMAIN...UNSETTLED WEATHER WILL RETURN THURSDAY AND THURSDAY NIGHT...POTENTIALLY ADDING TO THE RUNOFF. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY FRIDAY MORNING. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE FCST AS THE TIME NEARS. SO FAR THE LOCATIONS EXPERIENCING RISES NEAR OR ABOVE BANKFULL HAVE BEEN ALSTON/ALSM4/ AND CHASSELL/CLLM4/ ON THE STURGEON RIVER AND CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER. SINCE SNOW MELT THE NEXT FEW DAYS WILL BE DIMINISHING...EXPECT THE RIVERS TO SLOWLY SUBSIDE AND NOT EXCEED FLOOD STAGE. OTHERWISE...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS OVER THE NEXT WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...VOSS MARINE...ROLFSON HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 PM EDT MON APR 21 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 415 PM EDT MON APR 21 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACROSS THE CNTRL AND ERN CONUS. IN THE NRN STREAM...A VIGOROUS SHORTWAVE WAS MOVING ACROSS NRN ONTARIO JUST TO THE N OF LAKE SUPERIOR. IN THE SRN STREAM...ANOTHER WAVE WAS MOVING ACROSS THE MID AND LWR MISSISSIPPI VALLEY. DESPITE STRENGTH AND PROXIMITY OF NRN STREAM WAVE...IT`S ONLY BEEN IN THE LAST HR THAT ISOLD -SHRA HAVE MANAGED TO DEVELOP ALONG ASSOCIATED SFC COLD FRONT WHICH IS RUNNING FROM NEAR ISLE ROYALE ACROSS THE KEWEENAW AND THEN S THRU IRON COUNTY. LIMITED COVERAGE IS DUE TO LACK OF INSTABILITY AND THE FACT THAT DEEP LAYER FORCING WITH WAVE IS PASSING MOSTLY N OF UPPER MI. OVER THE NEXT SEVERAL HRS...WILL CARRY MAINLY ISOLD -SHRA COVERAGE ALONG COLD FRONT AS IT SWEEPS E. ATTENTION THEN TURNS TO HEALTHY CAA AND LOW CLOUD/-FZDZ/DZ POTENTIAL. WITH 850MB TEMPS FALLING TO AROUND -8C...LAKE EFFECT PCPN WON`T BE A CONCERN TONIGHT INTO TUE MORNING. HOWEVER...MODELS CONTINUE TO SHOW SIGNIFICANT LOW-LEVEL MOISTENING TONIGHT WHICH APPEARS ON TRACK GIVEN IFR CIGS THAT WERE OBSERVED UPSTREAM IN NRN MN/ADJACENT ONTARIO EARLIER TODAY. DAYTIME HEATING HAS RAISED CIGS...BUT CLOUDS CONTINUE TO HEAD SE EVEN THOUGH SLOWED BY MIXING OUT OF MOISTURE AT THE LEADING EDGE. ONCE DAYTIME HEATING DIMINISHES...CLOUDS WILL MAKE A QUICKER RUN TO THE SE INTO UPPER MI. EXAMINATION OF FCST SOUNDINGS SHOW MOISTURE DEPTH INCREASES TO 800 TO 700MB...AND WITH TEMPS WITHIN THE MOISTURE DEPTH WARMER THAN -10C...PRESENCE OF ICE CRYSTALS IS UNLIKELY. SO...IF THERE IS ANY PCPN...PTYPE SHOULD BE JUST -DZ/-FZDZ. HOWEVER...SINCE MODEL TREND HAS BEEN FOR MOISTURE DEPTH TO BE DEEPER AND CLOSER TO -10C...WILL INCLUDE A MENTION OF FLURRIES AS WELL. WHILE CONFIDENCE IS NOT HIGH...WILL CONTINUE WITH LOW POPS FOR -DZ/-FZDZ/FLURRIES OVERNIGHT THRU TUE MORNING...MAINLY IN THE AREAS WHERE UPSLOPING OCCURS WITH A NNW WIND. WITH THE BETTER MOISTURE OVER THE E...WILL NOT MENTION ANY PCPN OVER THE FAR W. ON TUE...IT APPEARS NOW THAT CLEARING TREND WILL BE SLOWER WITH 850MB TROF FIRMLY OVER THE FCST AREA AT 18Z. ANY LOCATIONS THAT START THE DAY WITH SOME SUNSHINE WILL SEE CU/STRATOCU RAPIDLY DEVELOP. DURING THE MID AND LATE AFTN...THE LAKE WILL BECOME A STABILIZING INFLUENCE...RESULTING IN CLOUDS CLEARING OUT OVER THE LAKE FIRST. THEN...THE CLEARING WILL SPREAD INLAND. WITH GRADIENT N/NW WINDS ENHANCED BY LAKE BREEZE...IT WILL BE A BLUSTERY/SHARPLY COLDER DAY WITH TEMPS 20 TO POSSIBLY AS MUCH AS 30 DEGREES COLDER IN SOME SPOTS. IT WILL BE ESPECIALLY CHILLY ALONG LAKE SUPERIOR WHERE TEMPS WON`T GET ABOVE THE MID 30S AT BEST. OVER THE FAR SCNTRL...TEMPS MAY RISE TO AROUND 50F. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 409 PM EDT MON APR 21 2014 HIGH PRESSURE BUILDING INTO THE UPPER GREAT LAKES REGION ON TUESDAY WILL LEAD TO A DRY PERIOD FOR TUESDAY NIGHT AND MUCH OF WEDNESDAY. THERE MAY BE A FEW LINGERING CLOUDS OVER THE FAR EAST TO START THE EVENING...BUT OTHERWISE EXPECT MOSTLY CLEAR SKIES TUESDAY NIGHT AND INTO WEDNESDAY ACROSS THE U.P. LOWS ON TUESDAY NIGHT WILL BE BELOW NORMAL AND IN THE 20S FOR MOST LOCATIONS. DID TREND SOME OF THE INTERIOR COLD SPOTS IN THE TEENS SINCE THE HIGH WILL BE OVERHEAD AND PWATS OF 40-45 PERCENT OF NORMAL WOULD SUPPORT GOING AT OR BELOW MOS GUIDANCE. THE APRIL SUNSHINE SHOULD HELP WARM TEMPS BACK CLOSER TO NORMAL FOR WEDNESDAY. LIGHT WINDS WILL GRADUALLY TURN TO THE SOUTHEAST DURING THE AFTERNOON...BUT THEY SHOULD BE LIGHT ENOUGH TO ALLOW LAKE BREEZES TO DEVELOP NEAR THE GREAT LAKES SHORELINES AND KEEP TEMPERATURES COOLER THERE. THE BULK OF THE LONG TERM FORECAST DEALS WITH AN UPPER LEVEL TROUGH AND ASSOCIATED LOW PRESSURE SYSTEM THAT MOVES THROUGH THE GREAT LAKES REGION WEDNESDAY NIGHT AND LIKELY CONTINUING INTO SATURDAY. THIS UPPER TROUGH IS CURRENTLY WEST OF THE PACIFIC NORTHWEST AND WILL COME ONSHORE TONIGHT. AS THIS SYSTEM CROSSES THE ROCKIES...A SURFACE LOW WILL DEVELOP IN THE LEE OF THE CANADIAN/NORTHERN ROCKIES AND SHIFT EAST INTO THE UPPER MISSISSIPPI VALLEY ON THURSDAY. AS THIS OCCURS...BROAD ISENTROPIC ASCENT ON THE 290-305K SURFACES WILL SPREAD NORTHEAST INTO UPPER MICHIGAN ON WEDNESDAY NIGHT. THIS FIRST WAVE WILL STEADILY PUSH NORTHEAST THROUGH THURSDAY...WHILE A SECONDARY WAVE OF PRECIPITATION MOVES IN ON THURSDAY AHEAD OF THE UPPER TROUGH AXIS MOVES INTO THE UPPER MISSISSIPPI VALLEY AND NEARS THE UPPER GREAT LAKES. THIS UPPER TROUGH WILL SHIFT THE HEAVIEST PRECIPITATION OVER THE NORTHERN HALF OF LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WITH THE MOISTURE PRESENT AND FORCING FROM THE UPPER TROUGH...WOULD EXPECT LINGERING LIGHT SHOWERS TO BE ONGOING OVER THE AREA FRIDAY INTO FRIDAY NIGHT. PRECIPITATION TYPE IS VERY TRICKY AT THIS POINT DUE TO THE VARYING SOLUTIONS IN THE MODELS WITH THE THERMAL FIELD WEDNESDAY NIGHT INTO THURSDAY. AS THE INITIAL SURGE OF PRECIP MOVES INTO THE AREA...IT ENCOUNTERS A ISOTHERMAL LAYER FROM THE SURFACE THROUGH 700MB WITH TEMPERATURES AT OR JUST ABOVE FREEZING. THIS LAYER REMAINS STEADY THROUGH MUCH OF THURSDAY. AS FOR THE MODELS...THE 12Z GFS HAS TRENDED A LITTLE COOLER COMPARED TO THE PREVIOUS RUNS...THE 12Z ECMWF REMAINS THE COOLEST AND THE 12Z GEM IS IN BETWEEN INITIALLY. UNFORTUNATELY IT IS DIFFICULT TO GET TOO SPECIFIC IN THESE SITUATIONS AS JUST A SLIGHT CHANGE IN TEMPERATURE BETWEEN 925-700MB OF 1-2C ONE WAY OR ANOTHER CAN MAKE A HUGE DIFFERENCE IN THE PRECIP TYPE AND ASSOCIATED IMPACTS. THUS...WILL FOLLOW AN IDEA OF RAIN/SNOW MIX WITH THE INITIAL SURGE OF PRECIP AND LIKELY TRANSITIONING TO MORE RAIN DURING THE DAY THURSDAY (OVER THE SOUTH HALF). THE NORTHWARD EXTENT OF THIS TRANSITION IS UNCERTAIN AT THIS POINT AND WILL PLACE IT OVER THE NORTH HALF OF LAKE SUPERIOR THURSDAY AFTERNOON/EVENING. COLDER AIR WILL BEGIN TO SHIFT INTO THE AREA ON THURSDAY NIGHT AS THE LOW SHIFTS EAST ACROSS UPPER MICHIGAN AND LEAD TO A TRANSITION TO ALL SNOW INTO FRIDAY. BY THE TIME THE PRECIPITATION WILL START TO TRANSITION TO ALL SNOW...THE HEAVIEST RATES WILL HAVE DEPARTED THE AREA AND EXPECT MORE OF A SCATTERED/LIGHT PRECIP TO REMAIN. WILL CONTINUE THE PREVIOUS SHIFTS IDEA OF THE HIGHEST QPF OVER THE WESTERN HALF OF THE CWA AND AROUND 0.5-1.0IN THROUGH THURSDAY EVENING. THAT MATCHES UP WELL WITH SOME OF THE ECMWF/GFS QPF PROBS. AS MENTIONED EARLIER...SNOW POTENTIAL IS TRICKY BUT THE SLIGHTLY COOLER TREND SEEN IN THE 12Z MODELS CREATES CONCERN FOR MEASURABLE (AND POTENTIALLY SIGNIFICANT) SNOWFALL OVER THE KEWEENAW DUE TO ITS CLOSER PROXIMITY TO THE COLDER AIR TO THE NORTH. FINALLY FOR THIS SYSTEM...THE COLD AIR AND BREEZING CONDITIONS SURGING IN BEHIND THE LOW ON FRIDAY AND INTO SATURDAY WILL MAKE IT FEEL MORE LIKE MARCH ACROSS THE AREA. WIND CHILL VALUES FRIDAY NIGHT AND INTO SATURDAY WILL BE IN THE TEENS AND 20S WITH THE LOWEST VALUES NEAR LAKE SUPERIOR. MODELS DO DIFFER ON HOW QUICKLY THE UPPER TROUGH DEPARTS THIS WEEKEND...SO THE FORECAST FOR THE END OF THE WEEKEND AND INTO EARLY NEXT WEEK IS UNCERTAIN. EVEN WITH THIS UNCERTAINTY...THE GENERAL IDEA OF BELOW NORMAL TEMPERATURES FOR THE WEEKEND AND INTO THE FIRST PART OF NEXT WEEK SEEMS REASONABLE AS A HUDSON BAY HIGH BECOMES STATIONARY AND LEADS TO DRY NORTHEASTERLY FLOW. PRECIPITATION CHANCES WILL DEPEND ON THE NEXT UPPER TROUGH THAT LOOKS TO BE LOCATED IN THE CENTRAL/SOUTHERN PLAINS AND AT THIS TIME MAY BE FAR ENOUGH SOUTH TO KEEP THE AREA DRY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 118 PM EDT MON APR 21 2014 DRY LOW-LEVEL AIR MASS WILL ALLOW VFR CONDITIONS TO CONTINUE THIS AFTN AT KIWD/KCMX/KSAW. ALTHOUGH COLD FRONT HAS PASSED KIWD/KCMX AND WILL REACH KSAW IN THE NEXT FEW HRS...DRY AIR MASS SHOULD PREVENT ANY -SHRA FROM OCCURRING AT KSAW. TONIGHT...GUSTY NW WINDS THAT WILL APPROACH 30KT AT THE MORE EXPOSED KCMX LOCATION WILL DRAW MUCH COLDER AIR AS WELL AS LOW CLOUDS INTO THE UPPER LAKES. MVFR CIGS WILL ARRIVE FIRST AT KCMX...EARLY THIS EVENING...AND THEN DURING THE MID TO LATE EVENING AT KIWD/KSAW. CIGS WILL LIKELY FALL FURTHER TO LOW MVFR AT KCMX/KSAW DURING THE NIGHT...AND IFR CIGS MAY EVENTUALLY DEVELOP LATE. ARRIVAL OF DRIER AIR WILL RESULT IN CLOUDS CLEARING OUT AT KIWD LATE TUE MORNING OR EARLY AFTN. CLEARING WILL OCCUR LATER IN THE DAY AT KCMX/KSAW WITH KSAW THE LATEST. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 415 PM EDT MON APR 21 2014 IN THE WAKE OF A COLD FRONT CURRENTLY PASSING ACROSS LAKE SUPERIOR...NW WINDS WILL INCREASE TO 15-30KT TONIGHT. STRONGEST WINDS WILL BE IN A CORRIDOR FROM NCNTRL TO SCNTRL/SE LAKE SUPERIOR WHERE SOME GALE FORCE GUSTS WILL PROBABLY OCCUR...MOSTLY IN THE OVERNIGHT/EARLY TUE MORNING TIME PERIOD. THESE STONG WINDS WILL DIMINISH FROM W TO E TUE INTO TUE EVENING AS A HIGH PRES RIDGE ARRIVES. WINDS WILL FALL TO UNDER 15KT TUE NIGHT WITH LIGHT WINDS LINGERING THRU AT LEAST WED MORNING AS HIGH PRES SLOWLY EXITS TO THE E. OVER WRN LAKE SUPERIOR...NE WINDS WILL BE ON THE INCREASE WED AFTN. AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE PLAINS LATER IN THE WEEK AND THE GRADIENT SHARPENS AGAIN...EASTERLY WINDS WILL BE ON THE INCREASE THU. WINDS WILL THEN BACK AROUND TO THE N FRI AS THE LOW PASSES ACROSS THE UPPER GREAT LAKES. DEPENDING ON THE TRACK AND INTENSITY OF THIS LOW...THERE COULD SOME GALE FORCE WINDS...POSSIBLY OVER WRN LAKE SUPERIOR AHEAD OF THE LOW AND THEN OVER CNTRL AND ERN LAKE SUPERIOR AS THE LOW PASSES TO THE E. && .HYDROLOGY... ISSUED AT 409 PM EDT MON APR 21 2014 ANOTHER ABOVE NORMAL TEMPERATURE DAY WAS SEEN ACROSS UPPER MICHIGAN TODAY...WITH HIGHS RISING INTO THE 50S TO LOWER 70S OVER MUCH OF THE AREA. THESE WARM TEMPERATURES AND SUNSHINE HAS LIKELY LED TO ANOTHER GOOD DAY OF MELTING IN THE AREAS THAT HAVE SNOW REMAINING. STARTED TO SEE THE SECOND WAVE OF SNOW MELT RISES ON THE AREA RIVERS YESTERDAY AND WILL CONTINUES TO SEE THAT INTO TONIGHT. BUT COLDER TEMPERATURES EXPECTED TO ARRIVE ON TUESDAY SHOULD REALLY SLOW THE MELT AND IN TURN LIMIT ADDITIONAL RISES. UNSETTLED WEATHER WILL RETURN FROM THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE FCST AS THE TIME NEARS. SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER...AND TO A LESSER EXTENT THE HYDE/FRDM4/ ON THE FORD RIVER (WHICH APPEARS TO HAVE BEEN FROM AN ICE JAM). WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME LOCATIONS MAY NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...ROLFSON MARINE...ROLFSON HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 PM EDT MON APR 21 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 424 AM EDT MON APR 21 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACRS THE CONUS WITH A STRONGER W-E POLAR BRANCH FLOW NEAR THE CNDN BORDER TO THE N OF A WEAKER SRN BRANCH OVER THE SCENTRAL STATES. SHRTWV RDG EMBEDDED IN THE POLAR BRANCH AND OVER NE MN/NW ONTARIO AS WELL AS VERY DRY AIR SHOWN ON THE 00Z INL/MPX RAOBS ARE BRINGING DRY WX TO UPR MI THIS MRNG EXCEPT OVER FAR SRN MENOMINEE COUNTY...WHERE SOME ISOLD -SHRA ARE STILL PRESENT ON THE NRN EDGE OF RIBBON OF DEEPER MSTR STRUNG W-E THRU THE CENTRAL LKS AND SAMPLED BY THE FAIRLY MOIST 00Z GRB RAOB. MORE WDSPRD SHRA/EMBEDDED TS ARE PRESENT OVER SW WI/FAR SE MN UNDER DEEPER MSTR/SOME UPR DVGC AHEAD OF DISTURBANCE ON THE NRN EDGE OF SRN BRANCH FLOW. ALTHOUGH COLDER CLOUD TOPS ARE EXPANDING TOWARD THE WI BORDER TO THE NE OF THESE SHOWERS...THE LOWER LVL W FLOW OF VERY DRY AIR FM THE DIRECTION OF MPX IS LIMITING THE N SPREAD OF THE SHRA LOCATED JUST S OF THAT RAOB SITE. OTRW...SOME LOCALLY DENSE FOG HAS FORMED OVER THE CENTRAL/ERN CWA AS THE DRIER AIR ALOFT MOVED OVER LOCATIONS THAT DID NOT SEE SGNFT LLVL DRYING YDAY AFTN. OVER THE W WHERE SFC DEWPTS MIXED OUT AS LO AS 25-30 AT IWD ON SUN AND TEMPS ARE STILL ABV 32 AT MOST SPOTS...THERE IS LTL IF ANY FOG. A MUCH STRONGER SHRTWV IN THE POLAR BRANCH FLOW IS NEAR LK WINNIPEG AND MOVING STEADILY TO THE E. THERE HAVE BEEN SOME SHOWERS AND EVEN SOME LGT STRIKES IN MANITOBA RIGHT UNDER THE STEEPER LAPSE RATES CLOSE TO THE CORE OF THIS DISTURBANCE. BUT SINCE THIS SHRTWV IS CUTOFF FM THE MOISTER AIRMASS TO THE S... THERE IS ONLY A NARROW BAND OF LIGHT SHOWERS ALONG ITS ATTENDANT COLD FNT MOVING THRU NW MN EARLY THIS MRNG. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE FOG EARLY THIS MRNG AND THEN PCPN CHCS LATER TODAY/TNGT AS POLAR BRANCH SHRTWV/ATTENDANT COLD FNT IMPACT UPR MI. TODAY...EXPECT LOCALLY DENSE FOG TO PERSIST EARLY THIS MRNG OVER THE SE HALF OF THE CWA...BUT INCRSG HI CLDS SHOULD LIMIT THE POTENTIAL FOR WDSPRD DENSE FOG. WL ISSUE AN SPS TO ALERT THE PUBLIC TO LOCALLY REDUCED VSBYS. SHRTWV NEAR LK WINNIPEG IS FCST TO MOVE E THRU NW ONTARIO AND DRAG IT ATTENDANT COLD FNT ACRS UPR MI THIS AFTN. SINCE BULK OF DPVA/DEEP LYR QVECTOR CNVGC WL REMAIN TO THE N AND JUST BRUSH THE NRN LAND CWA...SUSPECT ONLY ISOLD-SCT SHOWERS WL ACCOMPANY THE FROPA. ALMOST ALL THE MODELS THAT WERE SHOWING A GREATER INTERACTION BTWN THIS SHRTWV/DEEPER MSTR TO THE S AND SGNFT EXPANSION OF THIS MSTR/SHOWERS INTO UPR MI HAVE RETREATED A BIT FM THIS FCST...A REASONABLE TREND CONSIDERING THE VERY DRY NATURE OF THE 00Z MPX RAOB AND LACK OF SGNFT BACKING OF THE UPR FLOW FM THE W THRU THE DAY. THE 00Z HI RES CNDN MODEL SHOWS THE HEAVIER PCPN OVERSPREADING MOST OF UPR MI ALONG WITH THE MOST UNSTABLE MIXED LYR CAPES AOA 1000 J/KG. FCST SDNGS FM THIS MODEL SHOW FAIRLY IMPRESSIVE MOISTENING THRU THE LOWER TROP WITH SFC DEWPTS RISING TO ARND 55...WHICH DOES NOT SEEM RSNBL IN THE ABSENCE OF A DEEPER SW FLOW. THE 00Z NAM SHOWS MORE MODEST MOISTENING/DESTABILIZATION OVER THE SCENTRL. WL CARRY THE HIER CHC POPS THIS AFTN WHERE THIS MODEL SHOWS THE GREATER INSTABILITY UP TO 700-800 J/KG OVER THE SCNTRL. INCLUDED A SCHC OF TS IN THIS AREA AS WELL GIVEN ARRIVAL OF COLD FNT DURING PEAK HEATING TIME THAT WL PUSH TEMPS WELL ABV NORMAL AGAIN IN THE PRESENCE OF H85 TEMPS NOT FAR FM 10C AND AWAY FM THE MODERATING INFLUENCE OF THE LKS. COOLER AIR WL ARRIVE OVER THE W LATER IN THE DAY FOLLOWING THE FROPA. TNGT...NW FLOW WITH H925 WINDS UP TO 25-35 KTS IN THE WAKE OF THE COLD FROPA WL DRIVE COLDER AIR BACK INTO THE UPR LKS TNGT. MODELS SHOW H85 TEMPS SINKING AS LO AS -7 TO -8C OVER THE W BY 12Z TUE. WHILE THIS INCOMING AIRMASS WL NOT BE COLD ENUF FOR LK EFFECT PCPN...MODELS DO SHOW SOME LLVL MOISTENING BLO STRENGTHENING SUBSIDENCE INVRN ARND H85 UNDER THE LARGE SCALE QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. GOING FCST SHOWS SOME DRIZZLE/FRZG DRIZZLE OVER THE HIER TERRAIN WITH MOISTENING/INVRN BASE BLO THE DGZ. THIS FCST SEEMS RSNBL...BUT DID ADD SOME FLURRIES AS WELL. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 409 PM EDT MON APR 21 2014 HIGH PRESSURE BUILDING INTO THE UPPER GREAT LAKES REGION ON TUESDAY WILL LEAD TO A DRY PERIOD FOR TUESDAY NIGHT AND MUCH OF WEDNESDAY. THERE MAY BE A FEW LINGERING CLOUDS OVER THE FAR EAST TO START THE EVENING...BUT OTHERWISE EXPECT MOSTLY CLEAR SKIES TUESDAY NIGHT AND INTO WEDNESDAY ACROSS THE U.P. LOWS ON TUESDAY NIGHT WILL BE BELOW NORMAL AND IN THE 20S FOR MOST LOCATIONS. DID TREND SOME OF THE INTERIOR COLD SPOTS IN THE TEENS SINCE THE HIGH WILL BE OVERHEAD AND PWATS OF 40-45 PERCENT OF NORMAL WOULD SUPPORT GOING AT OR BELOW MOS GUIDANCE. THE APRIL SUNSHINE SHOULD HELP WARM TEMPS BACK CLOSER TO NORMAL FOR WEDNESDAY. LIGHT WINDS WILL GRADUALLY TURN TO THE SOUTHEAST DURING THE AFTERNOON...BUT THEY SHOULD BE LIGHT ENOUGH TO ALLOW LAKE BREEZES TO DEVELOP NEAR THE GREAT LAKES SHORELINES AND KEEP TEMPERATURES COOLER THERE. THE BULK OF THE LONG TERM FORECAST DEALS WITH AN UPPER LEVEL TROUGH AND ASSOCIATED LOW PRESSURE SYSTEM THAT MOVES THROUGH THE GREAT LAKES REGION WEDNESDAY NIGHT AND LIKELY CONTINUING INTO SATURDAY. THIS UPPER TROUGH IS CURRENTLY WEST OF THE PACIFIC NORTHWEST AND WILL COME ONSHORE TONIGHT. AS THIS SYSTEM CROSSES THE ROCKIES...A SURFACE LOW WILL DEVELOP IN THE LEE OF THE CANADIAN/NORTHERN ROCKIES AND SHIFT EAST INTO THE UPPER MISSISSIPPI VALLEY ON THURSDAY. AS THIS OCCURS...BROAD ISENTROPIC ASCENT ON THE 290-305K SURFACES WILL SPREAD NORTHEAST INTO UPPER MICHIGAN ON WEDNESDAY NIGHT. THIS FIRST WAVE WILL STEADILY PUSH NORTHEAST THROUGH THURSDAY...WHILE A SECONDARY WAVE OF PRECIPITATION MOVES IN ON THURSDAY AHEAD OF THE UPPER TROUGH AXIS MOVES INTO THE UPPER MISSISSIPPI VALLEY AND NEARS THE UPPER GREAT LAKES. THIS UPPER TROUGH WILL SHIFT THE HEAVIEST PRECIPITATION OVER THE NORTHERN HALF OF LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WITH THE MOISTURE PRESENT AND FORCING FROM THE UPPER TROUGH...WOULD EXPECT LINGERING LIGHT SHOWERS TO BE ONGOING OVER THE AREA FRIDAY INTO FRIDAY NIGHT. PRECIPITATION TYPE IS VERY TRICKY AT THIS POINT DUE TO THE VARYING SOLUTIONS IN THE MODELS WITH THE THERMAL FIELD WEDNESDAY NIGHT INTO THURSDAY. AS THE INITIAL SURGE OF PRECIP MOVES INTO THE AREA...IT ENCOUNTERS A ISOTHERMAL LAYER FROM THE SURFACE THROUGH 700MB WITH TEMPERATURES AT OR JUST ABOVE FREEZING. THIS LAYER REMAINS STEADY THROUGH MUCH OF THURSDAY. AS FOR THE MODELS...THE 12Z GFS HAS TRENDED A LITTLE COOLER COMPARED TO THE PREVIOUS RUNS...THE 12Z ECMWF REMAINS THE COOLEST AND THE 12Z GEM IS IN BETWEEN INITIALLY. UNFORTUNATELY IT IS DIFFICULT TO GET TOO SPECIFIC IN THESE SITUATIONS AS JUST A SLIGHT CHANGE IN TEMPERATURE BETWEEN 925-700MB OF 1-2C ONE WAY OR ANOTHER CAN MAKE A HUGE DIFFERENCE IN THE PRECIP TYPE AND ASSOCIATED IMPACTS. THUS...WILL FOLLOW AN IDEA OF RAIN/SNOW MIX WITH THE INITIAL SURGE OF PRECIP AND LIKELY TRANSITIONING TO MORE RAIN DURING THE DAY THURSDAY (OVER THE SOUTH HALF). THE NORTHWARD EXTENT OF THIS TRANSITION IS UNCERTAIN AT THIS POINT AND WILL PLACE IT OVER THE NORTH HALF OF LAKE SUPERIOR THURSDAY AFTERNOON/EVENING. COLDER AIR WILL BEGIN TO SHIFT INTO THE AREA ON THURSDAY NIGHT AS THE LOW SHIFTS EAST ACROSS UPPER MICHIGAN AND LEAD TO A TRANSITION TO ALL SNOW INTO FRIDAY. BY THE TIME THE PRECIPITATION WILL START TO TRANSITION TO ALL SNOW...THE HEAVIEST RATES WILL HAVE DEPARTED THE AREA AND EXPECT MORE OF A SCATTERED/LIGHT PRECIP TO REMAIN. WILL CONTINUE THE PREVIOUS SHIFTS IDEA OF THE HIGHEST QPF OVER THE WESTERN HALF OF THE CWA AND AROUND 0.5-1.0IN THROUGH THURSDAY EVENING. THAT MATCHES UP WELL WITH SOME OF THE ECMWF/GFS QPF PROBS. AS MENTIONED EARLIER...SNOW POTENTIAL IS TRICKY BUT THE SLIGHTLY COOLER TREND SEEN IN THE 12Z MODELS CREATES CONCERN FOR MEASURABLE (AND POTENTIALLY SIGNIFICANT) SNOWFALL OVER THE KEWEENAW DUE TO ITS CLOSER PROXIMITY TO THE COLDER AIR TO THE NORTH. FINALLY FOR THIS SYSTEM...THE COLD AIR AND BREEZING CONDITIONS SURGING IN BEHIND THE LOW ON FRIDAY AND INTO SATURDAY WILL MAKE IT FEEL MORE LIKE MARCH ACROSS THE AREA. WIND CHILL VALUES FRIDAY NIGHT AND INTO SATURDAY WILL BE IN THE TEENS AND 20S WITH THE LOWEST VALUES NEAR LAKE SUPERIOR. MODELS DO DIFFER ON HOW QUICKLY THE UPPER TROUGH DEPARTS THIS WEEKEND...SO THE FORECAST FOR THE END OF THE WEEKEND AND INTO EARLY NEXT WEEK IS UNCERTAIN. EVEN WITH THIS UNCERTAINTY...THE GENERAL IDEA OF BELOW NORMAL TEMPERATURES FOR THE WEEKEND AND INTO THE FIRST PART OF NEXT WEEK SEEMS REASONABLE AS A HUDSON BAY HIGH BECOMES STATIONARY AND LEADS TO DRY NORTHEASTERLY FLOW. PRECIPITATION CHANCES WILL DEPEND ON THE NEXT UPPER TROUGH THAT LOOKS TO BE LOCATED IN THE CENTRAL/SOUTHERN PLAINS AND AT THIS TIME MAY BE FAR ENOUGH SOUTH TO KEEP THE AREA DRY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 118 PM EDT MON APR 21 2014 DRY LOW-LEVEL AIR MASS WILL ALLOW VFR CONDITIONS TO CONTINUE THIS AFTN AT KIWD/KCMX/KSAW. ALTHOUGH COLD FRONT HAS PASSED KIWD/KCMX AND WILL REACH KSAW IN THE NEXT FEW HRS...DRY AIR MASS SHOULD PREVENT ANY -SHRA FROM OCCURRING AT KSAW. TONIGHT...GUSTY NW WINDS THAT WILL APPROACH 30KT AT THE MORE EXPOSED KCMX LOCATION WILL DRAW MUCH COLDER AIR AS WELL AS LOW CLOUDS INTO THE UPPER LAKES. MVFR CIGS WILL ARRIVE FIRST AT KCMX...EARLY THIS EVENING...AND THEN DURING THE MID TO LATE EVENING AT KIWD/KSAW. CIGS WILL LIKELY FALL FURTHER TO LOW MVFR AT KCMX/KSAW DURING THE NIGHT...AND IFR CIGS MAY EVENTUALLY DEVELOP LATE. ARRIVAL OF DRIER AIR WILL RESULT IN CLOUDS CLEARING OUT AT KIWD LATE TUE MORNING OR EARLY AFTN. CLEARING WILL OCCUR LATER IN THE DAY AT KCMX/KSAW WITH KSAW THE LATEST. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 424 AM EDT MON APR 21 2014 LIGHT WINDS UNDER 15 KTS THIS MORNING ASSOCIATED WITH WEAK HIGH PRESSURE RIDGE WILL SHIFT TO THE NW LATE TODAY/THIS EVENING FOLLOWING A COLD FRONTAL PASSAGE AND INCREASE UP TO 25-30 KTS TONIGHT AS MUCH COLDER AIR INVADES THE UPPER LAKES. NOT OUT OF THE QUESTION THERE COULD BE SOME GALES OVER PORTIONS OF THE EAST HALF OF THE LAKE UNDER THE SHARPER GRADIENT/STRONGEST LOW LEVEL WINDS. MENTIONED SOME GALE FORCE GUSTS UP TO 35 KTS OVER THE ECENTRAL FOR NOW. THESE STONG WINDS WILL DIMINISH TUE THRU WED AS A HI PRES RIDGE AND WEAKER PRES GRADIENT MOVE OVER THE AREA. AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE PLAINS LATER IN THE WEEK AND THE GRADIENT SHARPENS AGAIN...INCREASING SE WINDS WILL SHIFT TO THE NE. DEPENDING ON THE TRACK AND INTENSITY OF THIS LO...THERE COULD BE AT LEAST A PERIOD OF GALE FORCE WINDS. && .HYDROLOGY... ISSUED AT 409 PM EDT MON APR 21 2014 ANOTHER ABOVE NORMAL TEMPERATURE DAY WAS SEEN ACROSS UPPER MICHIGAN TODAY...WITH HIGHS RISING INTO THE 50S TO LOWER 70S OVER MUCH OF THE AREA. THESE WARM TEMPERATURES AND SUNSHINE HAS LIKELY LED TO ANOTHER GOOD DAY OF MELTING IN THE AREAS THAT HAVE SNOW REMAINING. STARTED TO SEE THE SECOND WAVE OF SNOW MELT RISES ON THE AREA RIVERS YESTERDAY AND WILL CONTINUES TO SEE THAT INTO TONIGHT. BUT COLDER TEMPERATURES EXPECTED TO ARRIVE ON TUESDAY SHOULD REALLY SLOW THE MELT AND IN TURN LIMIT ADDITIONAL RISES. UNSETTLED WEATHER WILL RETURN FROM THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE FCST AS THE TIME NEARS. SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE ONTONAGON RIVER...CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER...AND TO A LESSER EXTENT THE HYDE/FRDM4/ ON THE FORD RIVER (WHICH APPEARS TO HAVE BEEN FROM AN ICE JAM). WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME...ALTHOUGH SOME LOCATIONS MAY NEAR BANKFULL. HOWEVER...ANY RIVER THAT HAS ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...ROLFSON MARINE...KC HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
221 PM EDT MON APR 21 2014 LATEST UPDATE... HYDRO .SYNOPSIS... ISSUED AT 318 AM EDT MON APR 21 2014 LOW PRESSURE MOVING ACROSS WISCONSIN AND LOWER MICHIGAN WILL BRING LIGHT RAIN TO SW LOWER TODAY AND TONIGHT. THIS IS A VERY SLOW MOVING SYSTEM AND GIVEN THE DRY AIR ALREADY IN PLACE...WE/RE NOT LOOKING AT TOO MUCH RAIN...PERHAPS A QUARTER INCH. TEMPERATURES WILL CLIMB INTO THE LOWER TO MID 70S AGAIN TODAY EXCEPT FOR AREAS NORTH OF US-10 WHERE 60S ARE EXPECTED. COOLER WEATHER CAN BE EXPECTED FOR THE REMAINDER OF THE WEEK WITH MORE RAIN POSSIBLE THURSDAY INTO FRIDAY. && .UPDATE... ISSUED AT 925 AM EDT MON APR 21 2014 UPDATED FORECAST TO CUT POPS FOR THIS AFTERNOON BASED ON RADAR AND LATEST HRRR WHICH SHOWS SHOWERS JUST ENTERING NORTHERN ILLINOIS ATTM AND NOT ARRIVING UNTIL LATE AFTERNOON. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 318 AM EDT MON APR 21 2014 FORECAST CONCERNS DEAL WITH RAIN CHANCES TODAY AS A SLOW MOVING LOW CROSSES WISCONSIN AND MICHIGAN. THE LOW IN WISCONSIN WILL SLOWLY MOVE ACROSS NRN LWR TODAY. AHEAD OF IT...WARM AIR WITH TEMPS IN THE 70S WILL BE NOTED. THE WARMER AIR WILL BRING SOME ELEVATED INSTABILITY WITH IT...BUT NOTHING TOO SIGNIFICANT. MUCAPE AROUND 500 J/KG AND LI/S SLIGHTLY BELOW 0C MAY BE ENOUGH TO GENERATE A FEW STORMS. KEPT THE CHC OF THUNDER IN THE GRIDS. FORECAST SOUNDINGS THIS AFTERNOON SHOW THE PRESENCE OF SOME DRIER AIR IN THE LOWER TROP. THIS MAY RESULT IN SOME GUSTY WINDS AS SHOWERS/STORMS MOVE ACROSS THE CWA. THE LOW SHOULD MOVE OVER LAKE HURON BY MIDNIGHT AND COOLER AIR WILL BEGIN TO FLOW BACK INTO THE CWA AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES. SUNSHINE WILL RETURN TUESDAY AND WEDNESDAY BUT HIGHS WILL ONLY BE IN THE LOWER TO MID 50S. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 318 AM EDT MON APR 21 2014 MODELS ARE IN FAIRLY GOOD AGREEMENT IN TRACKING A COLD FRONT THROUGH THE REGION THU NIGHT. A SOUTHERLY LOW LEVEL JET MOVES IN AHEAD OF THE COLD FRONT. THAT WILL ACT TO DEVELOP A BAND OF SHOWERS. THESE SHOWERS WILL CROSS THE FORECAST AREA...WITH MOST LOCATIONS EXPECTED TO SEE SOME PRECIPITATION. WILL KEEP POPS RELATIVELY HIGH THEN. SOME INSTABILITY IS SHOWING UP IN THE MODELS WITH THIS RUN...SO WE MAY NEED TO ADD THUNDER TO THE FORECAST. BEHIND THE COLD FRONT IT WILL TURN WINDY ON FRIDAY. GUSTS OVER 35M MPH LOOK LIKELY. AS THE UPPER LOW APPROACHES...SHOWERS SHOULD DEVELOP ESPECIALLY IN THE AFTERNOON. THE HIGH RES EURO DOES SHOW A MORE NORTHERLY TRACK TO THE IS UPPER LOW WITH THE 00Z MON RUN. THE GFS IS STRONGER AND FURTHER SOUTH WITH THIS FEATURE AS COMPARED TO THE HIGH RES EURO. FORECAST SOUNDINGS SHOW SOME CAPE DURING THE AFTERNOON. MAY NEED TO ADD THUNDER TO THE FORECAST. SHOWERS LOOK HIGH BASED GIVEN THE LARGE T/TD SPREAD AT THE SURFACE. I WILL MAINTAIN THE RISK FOR SHOWERS IN THE FORECAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 122 PM EDT MON APR 21 2014 SHOWERS WILL GRADUALLY DEVELOP THIS AFTERNOON AND EVENING AND CONDITIONS WILL GRADUALLY DETERIORATE FROM VFR TO MVFR AS LOWER CLOUDS AND SHOWERS MOVE IN. CANNOT RULE OUT AN ISOLATED STORM LATE THIS AFTERNOON AND EVENING BUT THERE IS NOT ENOUGH CONFIDENCE IN CONVECTIVE POTENTIAL TO WARRANT INCLUSION IN THE TERMINAL FCSTS AT THIS TIME. CONDITIONS WILL IMPROVE TO VFR TUESDAY AND WNW WINDS WILL RAMP UP TO AROUND 15 TO 20 KTS WITH GUSTS TO 25 KTS BY LATE MORNING. && .HYDROLOGY... ISSUED AT 220 PM EDT MON APR 21 2014 WARNINGS NO LONGER EXIST ON ANY OF THE AREA RIVERS OR STREAMS. ALL HAVE SINCE BEEN DOWNGRADED TO ADVISORIES...WHICH ARE EVEN NUMBERED THEMSELVES. SCOTTVILLE...CROTON AND EVART ARE THE HOLD OUTS WITH THE ONGOING ADVISORIES. CONDITIONS CONTINUE TO IMPROVE WITH DROPPING RIVER LEVELS BUT SOME LOCALIZED AFFECTS ARE STILL POSSIBLE. WE WILL SEE A QUICK HIT OF RAINFALL THIS AFTERNOON THROUGH LATE THIS EVENING. TOTAL RAINFALL AMOUNTS SHOULD REMAIN WELL SHY OF CREATING ANY CONCERN FOR RIVERS AND STREAMS. THE NEXT CHANCE OF RAIN MOVES IN BY THURSDAY AND FRIDAY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...OSTUNO SYNOPSIS...93 SHORT TERM...93 LONG TERM...MJS AVIATION...LAURENS HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
124 PM EDT MON APR 21 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 318 AM EDT MON APR 21 2014 LOW PRESSURE MOVING ACROSS WISCONSIN AND LOWER MICHIGAN WILL BRING LIGHT RAIN TO SW LOWER TODAY AND TONIGHT. THIS IS A VERY SLOW MOVING SYSTEM AND GIVEN THE DRY AIR ALREADY IN PLACE...WE/RE NOT LOOKING AT TOO MUCH RAIN...PERHAPS A QUARTER INCH. TEMPERATURES WILL CLIMB INTO THE LOWER TO MID 70S AGAIN TODAY EXCEPT FOR AREAS NORTH OF US-10 WHERE 60S ARE EXPECTED. COOLER WEATHER CAN BE EXPECTED FOR THE REMAINDER OF THE WEEK WITH MORE RAIN POSSIBLE THURSDAY INTO FRIDAY. && .UPDATE... ISSUED AT 925 AM EDT MON APR 21 2014 UPDATED FORECAST TO CUT POPS FOR THIS AFTERNOON BASED ON RADAR AND LATEST HRRR WHICH SHOWS SHOWERS JUST ENTERING NORTHERN ILLINOIS ATTM AND NOT ARRIVING UNTIL LATE AFTERNOON. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 318 AM EDT MON APR 21 2014 FORECAST CONCERNS DEAL WITH RAIN CHANCES TODAY AS A SLOW MOVING LOW CROSSES WISCONSIN AND MICHIGAN. THE LOW IN WISCONSIN WILL SLOWLY MOVE ACROSS NRN LWR TODAY. AHEAD OF IT...WARM AIR WITH TEMPS IN THE 70S WILL BE NOTED. THE WARMER AIR WILL BRING SOME ELEVATED INSTABILITY WITH IT...BUT NOTHING TOO SIGNIFICANT. MUCAPE AROUND 500 J/KG AND LI/S SLIGHTLY BELOW 0C MAY BE ENOUGH TO GENERATE A FEW STORMS. KEPT THE CHC OF THUNDER IN THE GRIDS. FORECAST SOUNDINGS THIS AFTERNOON SHOW THE PRESENCE OF SOME DRIER AIR IN THE LOWER TROP. THIS MAY RESULT IN SOME GUSTY WINDS AS SHOWERS/STORMS MOVE ACROSS THE CWA. THE LOW SHOULD MOVE OVER LAKE HURON BY MIDNIGHT AND COOLER AIR WILL BEGIN TO FLOW BACK INTO THE CWA AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES. SUNSHINE WILL RETURN TUESDAY AND WEDNESDAY BUT HIGHS WILL ONLY BE IN THE LOWER TO MID 50S. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 318 AM EDT MON APR 21 2014 MODELS ARE IN FAIRLY GOOD AGREEMENT IN TRACKING A COLD FRONT THROUGH THE REGION THU NIGHT. A SOUTHERLY LOW LEVEL JET MOVES IN AHEAD OF THE COLD FRONT. THAT WILL ACT TO DEVELOP A BAND OF SHOWERS. THESE SHOWERS WILL CROSS THE FORECAST AREA...WITH MOST LOCATIONS EXPECTED TO SEE SOME PRECIPITATION. WILL KEEP POPS RELATIVELY HIGH THEN. SOME INSTABILITY IS SHOWING UP IN THE MODELS WITH THIS RUN...SO WE MAY NEED TO ADD THUNDER TO THE FORECAST. BEHIND THE COLD FRONT IT WILL TURN WINDY ON FRIDAY. GUSTS OVER 35M MPH LOOK LIKELY. AS THE UPPER LOW APPROACHES...SHOWERS SHOULD DEVELOP ESPECIALLY IN THE AFTERNOON. THE HIGH RES EURO DOES SHOW A MORE NORTHERLY TRACK TO THE IS UPPER LOW WITH THE 00Z MON RUN. THE GFS IS STRONGER AND FURTHER SOUTH WITH THIS FEATURE AS COMPARED TO THE HIGH RES EURO. FORECAST SOUNDINGS SHOW SOME CAPE DURING THE AFTERNOON. MAY NEED TO ADD THUNDER TO THE FORECAST. SHOWERS LOOK HIGH BASED GIVEN THE LARGE T/TD SPREAD AT THE SURFACE. I WILL MAINTAIN THE RISK FOR SHOWERS IN THE FORECAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 122 PM EDT MON APR 21 2014 SHOWERS WILL GRADUALLY DEVELOP THIS AFTERNOON AND EVENING AND CONDITIONS WILL GRADUALLY DETERIORATE FROM VFR TO MVFR AS LOWER CLOUDS AND SHOWERS MOVE IN. CANNOT RULE OUT AN ISOLATED STORM LATE THIS AFTERNOON AND EVENING BUT THERE IS NOT ENOUGH CONFIDENCE IN CONVECTIVE POTENTIAL TO WARRANT INCLUSION IN THE TERMINAL FCSTS AT THIS TIME. CONDITIONS WILL IMPROVE TO VFR TUESDAY AND WNW WINDS WILL RAMP UP TO AROUND 15 TO 20 KTS WITH GUSTS TO 25 KTS BY LATE MORNING. && .HYDROLOGY... ISSUED AT 1153 AM EDT SUN APR 20 2014 MINOR FLOODING EXISTS ON THE MUSKEGON RIVER AT CROTON AND EVART. THE DOWNWARD TREND CONTINUES ON ALL AREA RIVERS AND TRIBUTARIES. WE SHOULD SEE A FEW MORE ADVISORIES DROP OFF THE LIST OVER THE NEXT 24 HOURS OR SO. HOWEVER...LOCAL IMPACTS MAY STILL BE EVIDENT OVER THE NEXT SEVERAL DAYS ALONG THE MUSKEGON RIVER. LIGHT RAIN IS POSSIBLE TONIGHT AHEAD OF A SLOW MOVING COLD FRONT. BEST CHANCES TONIGHT SHOULD REMAIN ALONG AND NORTH OF HIGHWAY 10. THE FRONT WILL FINALLY PUSH THROUGH MONDAY AFTERNOON AND THATS WHEN RAIN IS MORE LIKELY THROUGHOUT THE AREA. PRECIPITATION AMOUNTS WILL BE RATHER LIGHT AND SHOULD NOT HAVE ANY ADVERSE AFFECTS ON RIVERS. ANOTHER SHOT OF RAIN WILL MOVE IN LATER IN THE WORK WEEK BUT IT LOOKS LIKE THE HEAVIEST SHOULD REMAIN WEST OF LOWER MICHIGAN. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...OSTUNO SYNOPSIS...93 SHORT TERM...93 LONG TERM...MJS AVIATION...LAURENS HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
120 PM EDT MON APR 21 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 424 AM EDT MON APR 21 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACRS THE CONUS WITH A STRONGER W-E POLAR BRANCH FLOW NEAR THE CNDN BORDER TO THE N OF A WEAKER SRN BRANCH OVER THE SCENTRAL STATES. SHRTWV RDG EMBEDDED IN THE POLAR BRANCH AND OVER NE MN/NW ONTARIO AS WELL AS VERY DRY AIR SHOWN ON THE 00Z INL/MPX RAOBS ARE BRINGING DRY WX TO UPR MI THIS MRNG EXCEPT OVER FAR SRN MENOMINEE COUNTY...WHERE SOME ISOLD -SHRA ARE STILL PRESENT ON THE NRN EDGE OF RIBBON OF DEEPER MSTR STRUNG W-E THRU THE CENTRAL LKS AND SAMPLED BY THE FAIRLY MOIST 00Z GRB RAOB. MORE WDSPRD SHRA/EMBEDDED TS ARE PRESENT OVER SW WI/FAR SE MN UNDER DEEPER MSTR/SOME UPR DVGC AHEAD OF DISTURBANCE ON THE NRN EDGE OF SRN BRANCH FLOW. ALTHOUGH COLDER CLOUD TOPS ARE EXPANDING TOWARD THE WI BORDER TO THE NE OF THESE SHOWERS...THE LOWER LVL W FLOW OF VERY DRY AIR FM THE DIRECTION OF MPX IS LIMITING THE N SPREAD OF THE SHRA LOCATED JUST S OF THAT RAOB SITE. OTRW...SOME LOCALLY DENSE FOG HAS FORMED OVER THE CENTRAL/ERN CWA AS THE DRIER AIR ALOFT MOVED OVER LOCATIONS THAT DID NOT SEE SGNFT LLVL DRYING YDAY AFTN. OVER THE W WHERE SFC DEWPTS MIXED OUT AS LO AS 25-30 AT IWD ON SUN AND TEMPS ARE STILL ABV 32 AT MOST SPOTS...THERE IS LTL IF ANY FOG. A MUCH STRONGER SHRTWV IN THE POLAR BRANCH FLOW IS NEAR LK WINNIPEG AND MOVING STEADILY TO THE E. THERE HAVE BEEN SOME SHOWERS AND EVEN SOME LGT STRIKES IN MANITOBA RIGHT UNDER THE STEEPER LAPSE RATES CLOSE TO THE CORE OF THIS DISTURBANCE. BUT SINCE THIS SHRTWV IS CUTOFF FM THE MOISTER AIRMASS TO THE S... THERE IS ONLY A NARROW BAND OF LIGHT SHOWERS ALONG ITS ATTENDANT COLD FNT MOVING THRU NW MN EARLY THIS MRNG. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE FOG EARLY THIS MRNG AND THEN PCPN CHCS LATER TODAY/TNGT AS POLAR BRANCH SHRTWV/ATTENDANT COLD FNT IMPACT UPR MI. TODAY...EXPECT LOCALLY DENSE FOG TO PERSIST EARLY THIS MRNG OVER THE SE HALF OF THE CWA...BUT INCRSG HI CLDS SHOULD LIMIT THE POTENTIAL FOR WDSPRD DENSE FOG. WL ISSUE AN SPS TO ALERT THE PUBLIC TO LOCALLY REDUCED VSBYS. SHRTWV NEAR LK WINNIPEG IS FCST TO MOVE E THRU NW ONTARIO AND DRAG IT ATTENDANT COLD FNT ACRS UPR MI THIS AFTN. SINCE BULK OF DPVA/DEEP LYR QVECTOR CNVGC WL REMAIN TO THE N AND JUST BRUSH THE NRN LAND CWA...SUSPECT ONLY ISOLD-SCT SHOWERS WL ACCOMPANY THE FROPA. ALMOST ALL THE MODELS THAT WERE SHOWING A GREATER INTERACTION BTWN THIS SHRTWV/DEEPER MSTR TO THE S AND SGNFT EXPANSION OF THIS MSTR/SHOWERS INTO UPR MI HAVE RETREATED A BIT FM THIS FCST...A REASONABLE TREND CONSIDERING THE VERY DRY NATURE OF THE 00Z MPX RAOB AND LACK OF SGNFT BACKING OF THE UPR FLOW FM THE W THRU THE DAY. THE 00Z HI RES CNDN MODEL SHOWS THE HEAVIER PCPN OVERSPREADING MOST OF UPR MI ALONG WITH THE MOST UNSTABLE MIXED LYR CAPES AOA 1000 J/KG. FCST SDNGS FM THIS MODEL SHOW FAIRLY IMPRESSIVE MOISTENING THRU THE LOWER TROP WITH SFC DEWPTS RISING TO ARND 55...WHICH DOES NOT SEEM RSNBL IN THE ABSENCE OF A DEEPER SW FLOW. THE 00Z NAM SHOWS MORE MODEST MOISTENING/DESTABILIZATION OVER THE SCENTRL. WL CARRY THE HIER CHC POPS THIS AFTN WHERE THIS MODEL SHOWS THE GREATER INSTABILITY UP TO 700-800 J/KG OVER THE SCNTRL. INCLUDED A SCHC OF TS IN THIS AREA AS WELL GIVEN ARRIVAL OF COLD FNT DURING PEAK HEATING TIME THAT WL PUSH TEMPS WELL ABV NORMAL AGAIN IN THE PRESENCE OF H85 TEMPS NOT FAR FM 10C AND AWAY FM THE MODERATING INFLUENCE OF THE LKS. COOLER AIR WL ARRIVE OVER THE W LATER IN THE DAY FOLLOWING THE FROPA. TNGT...NW FLOW WITH H925 WINDS UP TO 25-35 KTS IN THE WAKE OF THE COLD FROPA WL DRIVE COLDER AIR BACK INTO THE UPR LKS TNGT. MODELS SHOW H85 TEMPS SINKING AS LO AS -7 TO -8C OVER THE W BY 12Z TUE. WHILE THIS INCOMING AIRMASS WL NOT BE COLD ENUF FOR LK EFFECT PCPN...MODELS DO SHOW SOME LLVL MOISTENING BLO STRENGTHENING SUBSIDENCE INVRN ARND H85 UNDER THE LARGE SCALE QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. GOING FCST SHOWS SOME DRIZZLE/FRZG DRIZZLE OVER THE HIER TERRAIN WITH MOISTENING/INVRN BASE BLO THE DGZ. THIS FCST SEEMS RSNBL...BUT DID ADD SOME FLURRIES AS WELL. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 543 AM EDT MON APR 21 2014 SFC TEMPS SHOULD WARM QUICKLY TUESDAY MORNING...LIMITING THE POTENTIAL FOR FREEZING DRIZZLE. WILL STILL KEEP DRIZZLE GOING GIVEN THE LIMITED LIKELIHOOD OF ICE CRYSTALS IN THE SOUNDING. OTHERWISE COOL N-NW WINDS WILL BE THE RULE...WITH 850MB TEMPS IN THE -6 TO -8C RANGE HELPING TO KEEP MAX SFC TEMPS TUESDAY IN THE UPPER 30S TO MID 40S OVER MUCH OF THE CWA. DRY HIGH PRESSURE OVERHEAD TUESDAY NIGHT INTO WEDNESDAY WILL RESULT IN NEARLY CALM WINDS WEDNESDAY MORNING. WITH FEW IF ANY CLOUDS AROUND AND PW VALUES FALLING TO AROUND 45 PERCENT OF NORMAL /0.25IN/ SHOULD ALLOW TEMPS TO FALL INTO THE 20S TUESDAY NIGHT/WEDNESDAY MORNING. PLENTY OF UNCERTAINTY REMAINS WITH OUR END OF THE WEEK SYSTEM. WHILE POPS HAVE BEEN INCREASED AND MUCH OF THE FOCUS FOR MODERATE TO HEAVY PRECIP REMAINS OVER THE W HALF OF UPPER MI...THE 21/00Z RUN OF THE ECMWF HAS BACKED AWAY FROM THE DEEPER MORE WRAPPED UP SFC LOW THAT IT/S 20/12Z RUN INDICATED. STILL...ALL INDICATIONS ARE THAT 0.5-1IN OF LIQUID WILL BE POSSIBLE NEAR AND W OF A LINE FROM MQT TO MNM THURSDAY INTO THURSDAY NIGHT. THE ECMWF ENSEMBLES HAVE 30-40 PERCENT CHANCE OF SEEING 1IN OR MORE OVER THE W HALF. GIVEN THAT MUCH OF THE SYSTEM IS AROUND 84HRS OR MORE INTO THE FUTURE...WILL CONTINUE WITH A MORE BROAD/AVERAGED SOLUTION AT THIS POINT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 118 PM EDT MON APR 21 2014 DRY LOW-LEVEL AIR MASS WILL ALLOW VFR CONDITIONS TO CONTINUE THIS AFTN AT KIWD/KCMX/KSAW. ALTHOUGH COLD FRONT HAS PASSED KIWD/KCMX AND WILL REACH KSAW IN THE NEXT FEW HRS...DRY AIR MASS SHOULD PREVENT ANY -SHRA FROM OCCURRING AT KSAW. TONIGHT...GUSTY NW WINDS THAT WILL APPROACH 30KT AT THE MORE EXPOSED KCMX LOCATION WILL DRAW MUCH COLDER AIR AS WELL AS LOW CLOUDS INTO THE UPPER LAKES. MVFR CIGS WILL ARRIVE FIRST AT KCMX...EARLY THIS EVENING...AND THEN DURING THE MID TO LATE EVENING AT KIWD/KSAW. CIGS WILL LIKELY FALL FURTHER TO LOW MVFR AT KCMX/KSAW DURING THE NIGHT...AND IFR CIGS MAY EVENTUALLY DEVELOP LATE. ARRIVAL OF DRIER AIR WILL RESULT IN CLOUDS CLEARING OUT AT KIWD LATE TUE MORNING OR EARLY AFTN. CLEARING WILL OCCUR LATER IN THE DAY AT KCMX/KSAW WITH KSAW THE LATEST. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 424 AM EDT MON APR 21 2014 LIGHT WINDS UNDER 15 KTS THIS MORNING ASSOCIATED WITH WEAK HIGH PRESSURE RIDGE WILL SHIFT TO THE NW LATE TODAY/THIS EVENING FOLLOWING A COLD FRONTAL PASSAGE AND INCREASE UP TO 25-30 KTS TONIGHT AS MUCH COLDER AIR INVADES THE UPPER LAKES. NOT OUT OF THE QUESTION THERE COULD BE SOME GALES OVER PORTIONS OF THE EAST HALF OF THE LAKE UNDER THE SHARPER GRADIENT/STRONGEST LOW LEVEL WINDS. MENTIONED SOME GALE FORCE GUSTS UP TO 35 KTS OVER THE ECENTRAL FOR NOW. THESE STONG WINDS WILL DIMINISH TUE THRU WED AS A HI PRES RIDGE AND WEAKER PRES GRADIENT MOVE OVER THE AREA. AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE PLAINS LATER IN THE WEEK AND THE GRADIENT SHARPENS AGAIN...INCREASING SE WINDS WILL SHIFT TO THE NE. DEPENDING ON THE TRACK AND INTENSITY OF THIS LO...THERE COULD BE AT LEAST A PERIOD OF GALE FORCE WINDS. && .HYDROLOGY... ISSUED AT 1202 AM EDT MON APR 21 2014 HIGHEST SNOW DEPTH REPORTED YESTERDAY MORNING OF 32IN AT MOHAWK WAS ABLE TO DROP DOWN TO 28IN BY LATE EVENING. AT THE OTHER END OF THE SPECTRUM...SEVERAL SITES FROM IWD THROUGH ISQ WERE REPORTING LITTLE TO NO SNOW. TODAY WILL BE ANOTHER DAY OF MELTING...AS HIGH TEMPERATURES JUMP INTO THE 50S AND LOW 60S FOR MUCH OF THE AREA. THE MELT WILL SLOW TUESDAY-TUESDAY NIGHT OVER N UPPER MI AS COLD N-NNW WINDS KEEP TEMPS TOPPING OUT IN THE 30S AND LOW 40S TUESDAY. AS FOR FURTHER OUT...TEMPERATURES WILL RETURN TO NEAR NORMAL VALUES TEMPORARILY WEDNESDAY BEFORE FALLING BACK INTO THE 30S AND 40S THROUGH THE UPCOMING WEEKEND. WILL CONTINUE TO NOTICE SIGNIFICANT STREAM/RIVER RISES OVER THE NEXT FEW DAYS. UNSETTLED WEATHER WILL RETURN FROM THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE W HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW PENINSULA WHERE 0.75-1IN OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. WE WILL CONTINUE TO REFINE THE FCST AS THE TIME NEARS. SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE ONTONAGON RIVER...AND TO A LESSER EXTENT THE HYDE/FRDM4/ ON THE FORD RIVER. WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...ANY RIVER THAT HAS ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...ROLFSON MARINE...KC HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
927 AM EDT MON APR 21 2014 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 318 AM EDT MON APR 21 2014 LOW PRESSURE MOVING ACROSS WISCONSIN AND LOWER MICHIGAN WILL BRING LIGHT RAIN TO SW LOWER TODAY AND TONIGHT. THIS IS A VERY SLOW MOVING SYSTEM AND GIVEN THE DRY AIR ALREADY IN PLACE...WE/RE NOT LOOKING AT TOO MUCH RAIN...PERHAPS A QUARTER INCH. TEMPERATURES WILL CLIMB INTO THE LOWER TO MID 70S AGAIN TODAY EXCEPT FOR AREAS NORTH OF US-10 WHERE 60S ARE EXPECTED. COOLER WEATHER CAN BE EXPECTED FOR THE REMAINDER OF THE WEEK WITH MORE RAIN POSSIBLE THURSDAY INTO FRIDAY. && .UPDATE... ISSUED AT 925 AM EDT MON APR 21 2014 UPDATED FORECAST TO CUT POPS FOR THIS AFTERNOON BASED ON RADAR AND LATEST HRRR WHICH SHOWS SHOWERS JUST ENTERING NORTHERN ILLINOIS ATTM AND NOT ARRIVING UNTIL LATE AFTERNOON. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 318 AM EDT MON APR 21 2014 FORECAST CONCERNS DEAL WITH RAIN CHANCES TODAY AS A SLOW MOVING LOW CROSSES WISCONSIN AND MICHIGAN. THE LOW IN WISCONSIN WILL SLOWLY MOVE ACROSS NRN LWR TODAY. AHEAD OF IT...WARM AIR WITH TEMPS IN THE 70S WILL BE NOTED. THE WARMER AIR WILL BRING SOME ELEVATED INSTABILITY WITH IT...BUT NOTHING TOO SIGNIFICANT. MUCAPE AROUND 500 J/KG AND LI/S SLIGHTLY BELOW 0C MAY BE ENOUGH TO GENERATE A FEW STORMS. KEPT THE CHC OF THUNDER IN THE GRIDS. FORECAST SOUNDINGS THIS AFTERNOON SHOW THE PRESENCE OF SOME DRIER AIR IN THE LOWER TROP. THIS MAY RESULT IN SOME GUSTY WINDS AS SHOWERS/STORMS MOVE ACROSS THE CWA. THE LOW SHOULD MOVE OVER LAKE HURON BY MIDNIGHT AND COOLER AIR WILL BEGIN TO FLOW BACK INTO THE CWA AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES. SUNSHINE WILL RETURN TUESDAY AND WEDNESDAY BUT HIGHS WILL ONLY BE IN THE LOWER TO MID 50S. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 318 AM EDT MON APR 21 2014 MODELS ARE IN FAIRLY GOOD AGREEMENT IN TRACKING A COLD FRONT THROUGH THE REGION THU NIGHT. A SOUTHERLY LOW LEVEL JET MOVES IN AHEAD OF THE COLD FRONT. THAT WILL ACT TO DEVELOP A BAND OF SHOWERS. THESE SHOWERS WILL CROSS THE FORECAST AREA...WITH MOST LOCATIONS EXPECTED TO SEE SOME PRECIPITATION. WILL KEEP POPS RELATIVELY HIGH THEN. SOME INSTABILITY IS SHOWING UP IN THE MODELS WITH THIS RUN...SO WE MAY NEED TO ADD THUNDER TO THE FORECAST. BEHIND THE COLD FRONT IT WILL TURN WINDY ON FRIDAY. GUSTS OVER 35M MPH LOOK LIKELY. AS THE UPPER LOW APPROACHES...SHOWERS SHOULD DEVELOP ESPECIALLY IN THE AFTERNOON. THE HIGH RES EURO DOES SHOW A MORE NORTHERLY TRACK TO THE IS UPPER LOW WITH THE 00Z MON RUN. THE GFS IS STRONGER AND FURTHER SOUTH WITH THIS FEATURE AS COMPARED TO THE HIGH RES EURO. FORECAST SOUNDINGS SHOW SOME CAPE DURING THE AFTERNOON. MAY NEED TO ADD THUNDER TO THE FORECAST. SHOWERS LOOK HIGH BASED GIVEN THE LARGE T/TD SPREAD AT THE SURFACE. I WILL MAINTAIN THE RISK FOR SHOWERS IN THE FORECAST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 626 AM EDT MON APR 21 2014 VFR WEATHER TO START THE PERIOD...BUT LATER THIS AFTERNOON AND INTO TONIGHT WE WILL SEE MVFR CLOUDS/VSBYS AS A COLD FRONT ARRIVES. SOME INSTABILITY WILL BE AROUND...AND THAT COULD SUPPORT A FEW THUNDERSTORMS. AS THE MOISTURE BECOMES SHALLOWER TONIGHT...WE MAY SEE SOME ICING SHOWING UP IN THE MVFR CLOUD DECK. && .HYDROLOGY... ISSUED AT 1153 AM EDT SUN APR 20 2014 MINOR FLOODING EXISTS ON THE MUSKEGON RIVER AT CROTON AND EVART. THE DOWNWARD TREND CONTINUES ON ALL AREA RIVERS AND TRIBUTARIES. WE SHOULD SEE A FEW MORE ADVISORIES DROP OFF THE LIST OVER THE NEXT 24 HOURS OR SO. HOWEVER...LOCAL IMPACTS MAY STILL BE EVIDENT OVER THE NEXT SEVERAL DAYS ALONG THE MUSKEGON RIVER. LIGHT RAIN IS POSSIBLE TONIGHT AHEAD OF A SLOW MOVING COLD FRONT. BEST CHANCES TONIGHT SHOULD REMAIN ALONG AND NORTH OF HIGHWAY 10. THE FRONT WILL FINALLY PUSH THROUGH MONDAY AFTERNOON AND THATS WHEN RAIN IS MORE LIKELY THROUGHOUT THE AREA. PRECIPITATION AMOUNTS WILL BE RATHER LIGHT AND SHOULD NOT HAVE ANY ADVERSE AFFECTS ON RIVERS. ANOTHER SHOT OF RAIN WILL MOVE IN LATER IN THE WORK WEEK BUT IT LOOKS LIKE THE HEAVIEST SHOULD REMAIN WEST OF LOWER MICHIGAN. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...OSTUNO SYNOPSIS...93 SHORT TERM...93 LONG TERM...MJS AVIATION...MJS HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
746 AM EDT MON APR 21 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 424 AM EDT MON APR 21 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACRS THE CONUS WITH A STRONGER W-E POLAR BRANCH FLOW NEAR THE CNDN BORDER TO THE N OF A WEAKER SRN BRANCH OVER THE SCENTRAL STATES. SHRTWV RDG EMBEDDED IN THE POLAR BRANCH AND OVER NE MN/NW ONTARIO AS WELL AS VERY DRY AIR SHOWN ON THE 00Z INL/MPX RAOBS ARE BRINGING DRY WX TO UPR MI THIS MRNG EXCEPT OVER FAR SRN MENOMINEE COUNTY...WHERE SOME ISOLD -SHRA ARE STILL PRESENT ON THE NRN EDGE OF RIBBON OF DEEPER MSTR STRUNG W-E THRU THE CENTRAL LKS AND SAMPLED BY THE FAIRLY MOIST 00Z GRB RAOB. MORE WDSPRD SHRA/EMBEDDED TS ARE PRESENT OVER SW WI/FAR SE MN UNDER DEEPER MSTR/SOME UPR DVGC AHEAD OF DISTURBANCE ON THE NRN EDGE OF SRN BRANCH FLOW. ALTHOUGH COLDER CLOUD TOPS ARE EXPANDING TOWARD THE WI BORDER TO THE NE OF THESE SHOWERS...THE LOWER LVL W FLOW OF VERY DRY AIR FM THE DIRECTION OF MPX IS LIMITING THE N SPREAD OF THE SHRA LOCATED JUST S OF THAT RAOB SITE. OTRW...SOME LOCALLY DENSE FOG HAS FORMED OVER THE CENTRAL/ERN CWA AS THE DRIER AIR ALOFT MOVED OVER LOCATIONS THAT DID NOT SEE SGNFT LLVL DRYING YDAY AFTN. OVER THE W WHERE SFC DEWPTS MIXED OUT AS LO AS 25-30 AT IWD ON SUN AND TEMPS ARE STILL ABV 32 AT MOST SPOTS...THERE IS LTL IF ANY FOG. A MUCH STRONGER SHRTWV IN THE POLAR BRANCH FLOW IS NEAR LK WINNIPEG AND MOVING STEADILY TO THE E. THERE HAVE BEEN SOME SHOWERS AND EVEN SOME LGT STRIKES IN MANITOBA RIGHT UNDER THE STEEPER LAPSE RATES CLOSE TO THE CORE OF THIS DISTURBANCE. BUT SINCE THIS SHRTWV IS CUTOFF FM THE MOISTER AIRMASS TO THE S... THERE IS ONLY A NARROW BAND OF LIGHT SHOWERS ALONG ITS ATTENDANT COLD FNT MOVING THRU NW MN EARLY THIS MRNG. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE FOG EARLY THIS MRNG AND THEN PCPN CHCS LATER TODAY/TNGT AS POLAR BRANCH SHRTWV/ATTENDANT COLD FNT IMPACT UPR MI. TODAY...EXPECT LOCALLY DENSE FOG TO PERSIST EARLY THIS MRNG OVER THE SE HALF OF THE CWA...BUT INCRSG HI CLDS SHOULD LIMIT THE POTENTIAL FOR WDSPRD DENSE FOG. WL ISSUE AN SPS TO ALERT THE PUBLIC TO LOCALLY REDUCED VSBYS. SHRTWV NEAR LK WINNIPEG IS FCST TO MOVE E THRU NW ONTARIO AND DRAG IT ATTENDANT COLD FNT ACRS UPR MI THIS AFTN. SINCE BULK OF DPVA/DEEP LYR QVECTOR CNVGC WL REMAIN TO THE N AND JUST BRUSH THE NRN LAND CWA...SUSPECT ONLY ISOLD-SCT SHOWERS WL ACCOMPANY THE FROPA. ALMOST ALL THE MODELS THAT WERE SHOWING A GREATER INTERACTION BTWN THIS SHRTWV/DEEPER MSTR TO THE S AND SGNFT EXPANSION OF THIS MSTR/SHOWERS INTO UPR MI HAVE RETREATED A BIT FM THIS FCST...A REASONABLE TREND CONSIDERING THE VERY DRY NATURE OF THE 00Z MPX RAOB AND LACK OF SGNFT BACKING OF THE UPR FLOW FM THE W THRU THE DAY. THE 00Z HI RES CNDN MODEL SHOWS THE HEAVIER PCPN OVERSPREADING MOST OF UPR MI ALONG WITH THE MOST UNSTABLE MIXED LYR CAPES AOA 1000 J/KG. FCST SDNGS FM THIS MODEL SHOW FAIRLY IMPRESSIVE MOISTENING THRU THE LOWER TROP WITH SFC DEWPTS RISING TO ARND 55...WHICH DOES NOT SEEM RSNBL IN THE ABSENCE OF A DEEPER SW FLOW. THE 00Z NAM SHOWS MORE MODEST MOISTENING/DESTABILIZATION OVER THE SCENTRL. WL CARRY THE HIER CHC POPS THIS AFTN WHERE THIS MODEL SHOWS THE GREATER INSTABILITY UP TO 700-800 J/KG OVER THE SCNTRL. INCLUDED A SCHC OF TS IN THIS AREA AS WELL GIVEN ARRIVAL OF COLD FNT DURING PEAK HEATING TIME THAT WL PUSH TEMPS WELL ABV NORMAL AGAIN IN THE PRESENCE OF H85 TEMPS NOT FAR FM 10C AND AWAY FM THE MODERATING INFLUENCE OF THE LKS. COOLER AIR WL ARRIVE OVER THE W LATER IN THE DAY FOLLOWING THE FROPA. TNGT...NW FLOW WITH H925 WINDS UP TO 25-35 KTS IN THE WAKE OF THE COLD FROPA WL DRIVE COLDER AIR BACK INTO THE UPR LKS TNGT. MODELS SHOW H85 TEMPS SINKING AS LO AS -7 TO -8C OVER THE W BY 12Z TUE. WHILE THIS INCOMING AIRMASS WL NOT BE COLD ENUF FOR LK EFFECT PCPN...MODELS DO SHOW SOME LLVL MOISTENING BLO STRENGTHENING SUBSIDENCE INVRN ARND H85 UNDER THE LARGE SCALE QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. GOING FCST SHOWS SOME DRIZZLE/FRZG DRIZZLE OVER THE HIER TERRAIN WITH MOISTENING/INVRN BASE BLO THE DGZ. THIS FCST SEEMS RSNBL...BUT DID ADD SOME FLURRIES AS WELL. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 543 AM EDT MON APR 21 2014 SFC TEMPS SHOULD WARM QUICKLY TUESDAY MORNING...LIMITING THE POTENTIAL FOR FREEZING DRIZZLE. WILL STILL KEEP DRIZZLE GOING GIVEN THE LIMITED LIKELIHOOD OF ICE CRYSTALS IN THE SOUNDING. OTHERWISE COOL N-NW WINDS WILL BE THE RULE...WITH 850MB TEMPS IN THE -6 TO -8C RANGE HELPING TO KEEP MAX SFC TEMPS TUESDAY IN THE UPPER 30S TO MID 40S OVER MUCH OF THE CWA. DRY HIGH PRESSURE OVERHEAD TUESDAY NIGHT INTO WEDNESDAY WILL RESULT IN NEARLY CALM WINDS WEDNESDAY MORNING. WITH FEW IF ANY CLOUDS AROUND AND PW VALUES FALLING TO AROUND 45 PERCENT OF NORMAL /0.25IN/ SHOULD ALLOW TEMPS TO FALL INTO THE 20S TUESDAY NIGHT/WEDNESDAY MORNING. PLENTY OF UNCERTAINTY REMAINS WITH OUR END OF THE WEEK SYSTEM. WHILE POPS HAVE BEEN INCREASED AND MUCH OF THE FOCUS FOR MODERATE TO HEAVY PRECIP REMAINS OVER THE W HALF OF UPPER MI...THE 21/00Z RUN OF THE ECMWF HAS BACKED AWAY FROM THE DEEPER MORE WRAPPED UP SFC LOW THAT IT/S 20/12Z RUN INDICATED. STILL...ALL INDICATIONS ARE THAT 0.5-1IN OF LIQUID WILL BE POSSIBLE NEAR AND W OF A LINE FROM MQT TO MNM THURSDAY INTO THURSDAY NIGHT. THE ECMWF ENSEMBLES HAVE 30-40 PERCENT CHANCE OF SEEING 1IN OR MORE OVER THE W HALF. GIVEN THAT MUCH OF THE SYSTEM IS AROUND 84HRS OR MORE INTO THE FUTURE...WILL CONTINUE WITH A MORE BROAD/AVERAGED SOLUTION AT THIS POINT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 727 AM EDT MON APR 21 2014 ANY LINGERING FOG AT SAW WL BURN OFF QUICKLY THIS MRNG WITH DAYTIME HEATING. EVEN THOUGH A COLD FNT WL SWING THRU UPR MI TODAY...THE AIRMASS WL BE TOO DRY FOR ANY SGNFT SHRA ACTIVITY. THE BEST CHC FOR A FEW -SHRA WL BE AT SAW...AS THE LATER ARRIVAL OF THE FNT WL BE IN BETTER PHASE WITH DAYTIME HEATING. GUSTY NW WINDS THAT WL APRCH 30 KTS AT THE MORE EXPOSED CMX LOCATION TNGT BEHIND THE FROPA WL DRAW MUCH COLDER AIR AS WELL AS SOME LO CLDS INTO THE UPR LKS. THE BEST CHC FOR IFR CONDITIONS WL BE AT IWD AND ESPECIALLY CMX...PLACES THAT WL EXPERIENCE THE SHARPEST UPSLOPE WIND COMPONENT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 424 AM EDT MON APR 21 2014 LIGHT WINDS UNDER 15 KTS THIS MORNING ASSOCIATED WITH WEAK HIGH PRESSURE RIDGE WILL SHIFT TO THE NW LATE TODAY/THIS EVENING FOLLOWING A COLD FRONTAL PASSAGE AND INCREASE UP TO 25-30 KTS TONIGHT AS MUCH COLDER AIR INVADES THE UPPER LAKES. NOT OUT OF THE QUESTION THERE COULD BE SOME GALES OVER PORTIONS OF THE EAST HALF OF THE LAKE UNDER THE SHARPER GRADIENT/STRONGEST LOW LEVEL WINDS. MENTIONED SOME GALE FORCE GUSTS UP TO 35 KTS OVER THE ECENTRAL FOR NOW. THESE STONG WINDS WILL DIMINISH TUE THRU WED AS A HI PRES RIDGE AND WEAKER PRES GRADIENT MOVE OVER THE AREA. AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE PLAINS LATER IN THE WEEK AND THE GRADIENT SHARPENS AGAIN...INCREASING SE WINDS WILL SHIFT TO THE NE. DEPENDING ON THE TRACK AND INTENSITY OF THIS LO...THERE COULD BE AT LEAST A PERIOD OF GALE FORCE WINDS. && .HYDROLOGY... ISSUED AT 1202 AM EDT MON APR 21 2014 HIGHEST SNOW DEPTH REPORTED YESTERDAY MORNING OF 32IN AT MOHAWK WAS ABLE TO DROP DOWN TO 28IN BY LATE EVENING. AT THE OTHER END OF THE SPECTRUM...SEVERAL SITES FROM IWD THROUGH ISQ WERE REPORTING LITTLE TO NO SNOW. TODAY WILL BE ANOTHER DAY OF MELTING...AS HIGH TEMPERATURES JUMP INTO THE 50S AND LOW 60S FOR MUCH OF THE AREA. THE MELT WILL SLOW TUESDAY-TUESDAY NIGHT OVER N UPPER MI AS COLD N-NNW WINDS KEEP TEMPS TOPPING OUT IN THE 30S AND LOW 40S TUESDAY. AS FOR FURTHER OUT...TEMPERATURES WILL RETURN TO NEAR NORMAL VALUES TEMPORARILY WEDNESDAY BEFORE FALLING BACK INTO THE 30S AND 40S THROUGH THE UPCOMING WEEKEND. WILL CONTINUE TO NOTICE SIGNIFICANT STREAM/RIVER RISES OVER THE NEXT FEW DAYS. UNSETTLED WEATHER WILL RETURN FROM THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE W HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW PENINSULA WHERE 0.75-1IN OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. WE WILL CONTINUE TO REFINE THE FCST AS THE TIME NEARS. SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE ONTONAGON RIVER...AND TO A LESSER EXTENT THE HYDE/FRDM4/ ON THE FORD RIVER. WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...ANY RIVER THAT HAS ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...KC MARINE...KC HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
544 AM EDT MON APR 21 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 424 AM EDT MON APR 21 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACRS THE CONUS WITH A STRONGER W-E POLAR BRANCH FLOW NEAR THE CNDN BORDER TO THE N OF A WEAKER SRN BRANCH OVER THE SCENTRAL STATES. SHRTWV RDG EMBEDDED IN THE POLAR BRANCH AND OVER NE MN/NW ONTARIO AS WELL AS VERY DRY AIR SHOWN ON THE 00Z INL/MPX RAOBS ARE BRINGING DRY WX TO UPR MI THIS MRNG EXCEPT OVER FAR SRN MENOMINEE COUNTY...WHERE SOME ISOLD -SHRA ARE STILL PRESENT ON THE NRN EDGE OF RIBBON OF DEEPER MSTR STRUNG W-E THRU THE CENTRAL LKS AND SAMPLED BY THE FAIRLY MOIST 00Z GRB RAOB. MORE WDSPRD SHRA/EMBEDDED TS ARE PRESENT OVER SW WI/FAR SE MN UNDER DEEPER MSTR/SOME UPR DVGC AHEAD OF DISTURBANCE ON THE NRN EDGE OF SRN BRANCH FLOW. ALTHOUGH COLDER CLOUD TOPS ARE EXPANDING TOWARD THE WI BORDER TO THE NE OF THESE SHOWERS...THE LOWER LVL W FLOW OF VERY DRY AIR FM THE DIRECTION OF MPX IS LIMITING THE N SPREAD OF THE SHRA LOCATED JUST S OF THAT RAOB SITE. OTRW...SOME LOCALLY DENSE FOG HAS FORMED OVER THE CENTRAL/ERN CWA AS THE DRIER AIR ALOFT MOVED OVER LOCATIONS THAT DID NOT SEE SGNFT LLVL DRYING YDAY AFTN. OVER THE W WHERE SFC DEWPTS MIXED OUT AS LO AS 25-30 AT IWD ON SUN AND TEMPS ARE STILL ABV 32 AT MOST SPOTS...THERE IS LTL IF ANY FOG. A MUCH STRONGER SHRTWV IN THE POLAR BRANCH FLOW IS NEAR LK WINNIPEG AND MOVING STEADILY TO THE E. THERE HAVE BEEN SOME SHOWERS AND EVEN SOME LGT STRIKES IN MANITOBA RIGHT UNDER THE STEEPER LAPSE RATES CLOSE TO THE CORE OF THIS DISTURBANCE. BUT SINCE THIS SHRTWV IS CUTOFF FM THE MOISTER AIRMASS TO THE S... THERE IS ONLY A NARROW BAND OF LIGHT SHOWERS ALONG ITS ATTENDANT COLD FNT MOVING THRU NW MN EARLY THIS MRNG. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE FOG EARLY THIS MRNG AND THEN PCPN CHCS LATER TODAY/TNGT AS POLAR BRANCH SHRTWV/ATTENDANT COLD FNT IMPACT UPR MI. TODAY...EXPECT LOCALLY DENSE FOG TO PERSIST EARLY THIS MRNG OVER THE SE HALF OF THE CWA...BUT INCRSG HI CLDS SHOULD LIMIT THE POTENTIAL FOR WDSPRD DENSE FOG. WL ISSUE AN SPS TO ALERT THE PUBLIC TO LOCALLY REDUCED VSBYS. SHRTWV NEAR LK WINNIPEG IS FCST TO MOVE E THRU NW ONTARIO AND DRAG IT ATTENDANT COLD FNT ACRS UPR MI THIS AFTN. SINCE BULK OF DPVA/DEEP LYR QVECTOR CNVGC WL REMAIN TO THE N AND JUST BRUSH THE NRN LAND CWA...SUSPECT ONLY ISOLD-SCT SHOWERS WL ACCOMPANY THE FROPA. ALMOST ALL THE MODELS THAT WERE SHOWING A GREATER INTERACTION BTWN THIS SHRTWV/DEEPER MSTR TO THE S AND SGNFT EXPANSION OF THIS MSTR/SHOWERS INTO UPR MI HAVE RETREATED A BIT FM THIS FCST...A REASONABLE TREND CONSIDERING THE VERY DRY NATURE OF THE 00Z MPX RAOB AND LACK OF SGNFT BACKING OF THE UPR FLOW FM THE W THRU THE DAY. THE 00Z HI RES CNDN MODEL SHOWS THE HEAVIER PCPN OVERSPREADING MOST OF UPR MI ALONG WITH THE MOST UNSTABLE MIXED LYR CAPES AOA 1000 J/KG. FCST SDNGS FM THIS MODEL SHOW FAIRLY IMPRESSIVE MOISTENING THRU THE LOWER TROP WITH SFC DEWPTS RISING TO ARND 55...WHICH DOES NOT SEEM RSNBL IN THE ABSENCE OF A DEEPER SW FLOW. THE 00Z NAM SHOWS MORE MODEST MOISTENING/DESTABILIZATION OVER THE SCENTRL. WL CARRY THE HIER CHC POPS THIS AFTN WHERE THIS MODEL SHOWS THE GREATER INSTABILITY UP TO 700-800 J/KG OVER THE SCNTRL. INCLUDED A SCHC OF TS IN THIS AREA AS WELL GIVEN ARRIVAL OF COLD FNT DURING PEAK HEATING TIME THAT WL PUSH TEMPS WELL ABV NORMAL AGAIN IN THE PRESENCE OF H85 TEMPS NOT FAR FM 10C AND AWAY FM THE MODERATING INFLUENCE OF THE LKS. COOLER AIR WL ARRIVE OVER THE W LATER IN THE DAY FOLLOWING THE FROPA. TNGT...NW FLOW WITH H925 WINDS UP TO 25-35 KTS IN THE WAKE OF THE COLD FROPA WL DRIVE COLDER AIR BACK INTO THE UPR LKS TNGT. MODELS SHOW H85 TEMPS SINKING AS LO AS -7 TO -8C OVER THE W BY 12Z TUE. WHILE THIS INCOMING AIRMASS WL NOT BE COLD ENUF FOR LK EFFECT PCPN...MODELS DO SHOW SOME LLVL MOISTENING BLO STRENGTHENING SUBSIDENCE INVRN ARND H85 UNDER THE LARGE SCALE QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. GOING FCST SHOWS SOME DRIZZLE/FRZG DRIZZLE OVER THE HIER TERRAIN WITH MOISTENING/INVRN BASE BLO THE DGZ. THIS FCST SEEMS RSNBL...BUT DID ADD SOME FLURRIES AS WELL. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 543 AM EDT MON APR 21 2014 SFC TEMPS SHOULD WARM QUICKLY TUESDAY MORNING...LIMITING THE POTENTIAL FOR FREEZING DRIZZLE. WILL STILL KEEP DRIZZLE GOING GIVEN THE LIMITED LIKELIHOOD OF ICE CRYSTALS IN THE SOUNDING. OTHERWISE COOL N-NW WINDS WILL BE THE RULE...WITH 850MB TEMPS IN THE -6 TO -8C RANGE HELPING TO KEEP MAX SFC TEMPS TUESDAY IN THE UPPER 30S TO MID 40S OVER MUCH OF THE CWA. DRY HIGH PRESSURE OVERHEAD TUESDAY NIGHT INTO WEDNESDAY WILL RESULT IN NEARLY CALM WINDS WEDNESDAY MORNING. WITH FEW IF ANY CLOUDS AROUND AND PW VALUES FALLING TO AROUND 45 PERCENT OF NORMAL /0.25IN/ SHOULD ALLOW TEMPS TO FALL INTO THE 20S TUESDAY NIGHT/WEDNESDAY MORNING. PLENTY OF UNCERTAINTY REMAINS WITH OUR END OF THE WEEK SYSTEM. WHILE POPS HAVE BEEN INCREASED AND MUCH OF THE FOCUS FOR MODERATE TO HEAVY PRECIP REMAINS OVER THE W HALF OF UPPER MI...THE 21/00Z RUN OF THE ECMWF HAS BACKED AWAY FROM THE DEEPER MORE WRAPPED UP SFC LOW THAT IT/S 20/12Z RUN INDICATED. STILL...ALL INDICATIONS ARE THAT 0.5-1IN OF LIQUID WILL BE POSSIBLE NEAR AND W OF A LINE FROM MQT TO MNM THURSDAY INTO THURSDAY NIGHT. THE ECMWF ENSEMBLES HAVE 30-40 PERCENT CHANCE OF SEEING 1IN OR MORE OVER THE W HALF. GIVEN THAT MUCH OF THE SYSTEM IS AROUND 84HRS OR MORE INTO THE FUTURE...WILL CONTINUE WITH A MORE BROAD/AVERAGED SOLUTION AT THIS POINT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 122 AM EDT MON APR 21 2014 THE BIG FCST CONCERN OVERNIGHT WILL BE FOG...ESPECIALLY AT KSAW WHERE DEWPOINTS REMAIN MOIST (IN THE LOWER 40S). HAVE FOLLOWED MOS GUIDANCE FOR MUCH OF THE TIMING ON THE FOG AND INTENSITY. KIWD MAY NOT SEE MUCH FOG TONIGHT AS LIGHT DOWNSLOPING SOUTHEAST WINDS WILL LIKELY LIMIT FOG POTENTIAL. THE CONCERN AT KCMX IS WHETHER DRIER AIR OVER LAKE SUPERIOR MAY LIMIT FOG POTENTIAL DESPITE WEAK UPSLOPE EAST FLOW DEVELOPING LATE TONIGHT. SINCE THE DEWPOINT DEPRESSION AT KCMX IS ONLY 2F STILL THINK PREVAILING IFR VBSY IS A GOOD BET FOR THE 07-14Z TIME FRAME. KSAW SHOULD HAVE THE BEST OPPORTUNITY TO FALL TO LIFR/PERHAPS VLIFR/BLO LANDING MINS BASED ON LOWER 40S DEWPOINTS AND LIGHT SOUTH-SOUTHEAST UPSLOPE FLOW DEVELOPING OVERNIGHT UNDER GENERALLY CLEAR SKIES. EXPECT THE FOG TO BURN OFF DURING THE MORNING AS MIXING INCREASES AND SOME MID CLOUDS APPROACH TOWARDS AFTERNOON. WINDS WILL SHIFT WESTERLY BEHIND TROUGH/FRONTAL PASSAGE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 424 AM EDT MON APR 21 2014 LIGHT WINDS UNDER 15 KTS THIS MORNING ASSOCIATED WITH WEAK HIGH PRESSURE RIDGE WILL SHIFT TO THE NW LATE TODAY/THIS EVENING FOLLOWING A COLD FRONTAL PASSAGE AND INCREASE UP TO 25-30 KTS TONIGHT AS MUCH COLDER AIR INVADES THE UPPER LAKES. NOT OUT OF THE QUESTION THERE COULD BE SOME GALES OVER PORTIONS OF THE EAST HALF OF THE LAKE UNDER THE SHARPER GRADIENT/STRONGEST LOW LEVEL WINDS. MENTIONED SOME GALE FORCE GUSTS UP TO 35 KTS OVER THE ECENTRAL FOR NOW. THESE STONG WINDS WILL DIMINISH TUE THRU WED AS A HI PRES RIDGE AND WEAKER PRES GRADIENT MOVE OVER THE AREA. AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE PLAINS LATER IN THE WEEK AND THE GRADIENT SHARPENS AGAIN...INCREASING SE WINDS WILL SHIFT TO THE NE. DEPENDING ON THE TRACK AND INTENSITY OF THIS LO...THERE COULD BE AT LEAST A PERIOD OF GALE FORCE WINDS. && .HYDROLOGY... ISSUED AT 1202 AM EDT MON APR 21 2014 HIGHEST SNOW DEPTH REPORTED YESTERDAY MORNING OF 32IN AT MOHAWK WAS ABLE TO DROP DOWN TO 28IN BY LATE EVENING. AT THE OTHER END OF THE SPECTRUM...SEVERAL SITES FROM IWD THROUGH ISQ WERE REPORTING LITTLE TO NO SNOW. TODAY WILL BE ANOTHER DAY OF MELTING...AS HIGH TEMPERATURES JUMP INTO THE 50S AND LOW 60S FOR MUCH OF THE AREA. THE MELT WILL SLOW TUESDAY-TUESDAY NIGHT OVER N UPPER MI AS COLD N-NNW WINDS KEEP TEMPS TOPPING OUT IN THE 30S AND LOW 40S TUESDAY. AS FOR FURTHER OUT...TEMPERATURES WILL RETURN TO NEAR NORMAL VALUES TEMPORARILY WEDNESDAY BEFORE FALLING BACK INTO THE 30S AND 40S THROUGH THE UPCOMING WEEKEND. WILL CONTINUE TO NOTICE SIGNIFICANT STREAM/RIVER RISES OVER THE NEXT FEW DAYS. UNSETTLED WEATHER WILL RETURN FROM THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE W HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW PENINSULA WHERE 0.75-1IN OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. WE WILL CONTINUE TO REFINE THE FCST AS THE TIME NEARS. SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE ONTONAGON RIVER...AND TO A LESSER EXTENT THE HYDE/FRDM4/ ON THE FORD RIVER. WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...ANY RIVER THAT HAS ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KF AVIATION...VOSS/KC MARINE...KC HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
425 AM EDT MON APR 21 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 424 AM EDT MON APR 21 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW REGIME ACRS THE CONUS WITH A STRONGER W-E POLAR BRANCH FLOW NEAR THE CNDN BORDER TO THE N OF A WEAKER SRN BRANCH OVER THE SCENTRAL STATES. SHRTWV RDG EMBEDDED IN THE POLAR BRANCH AND OVER NE MN/NW ONTARIO AS WELL AS VERY DRY AIR SHOWN ON THE 00Z INL/MPX RAOBS ARE BRINGING DRY WX TO UPR MI THIS MRNG EXCEPT OVER FAR SRN MENOMINEE COUNTY...WHERE SOME ISOLD -SHRA ARE STILL PRESENT ON THE NRN EDGE OF RIBBON OF DEEPER MSTR STRUNG W-E THRU THE CENTRAL LKS AND SAMPLED BY THE FAIRLY MOIST 00Z GRB RAOB. MORE WDSPRD SHRA/EMBEDDED TS ARE PRESENT OVER SW WI/FAR SE MN UNDER DEEPER MSTR/SOME UPR DVGC AHEAD OF DISTURBANCE ON THE NRN EDGE OF SRN BRANCH FLOW. ALTHOUGH COLDER CLOUD TOPS ARE EXPANDING TOWARD THE WI BORDER TO THE NE OF THESE SHOWERS...THE LOWER LVL W FLOW OF VERY DRY AIR FM THE DIRECTION OF MPX IS LIMITING THE N SPREAD OF THE SHRA LOCATED JUST S OF THAT RAOB SITE. OTRW...SOME LOCALLY DENSE FOG HAS FORMED OVER THE CENTRAL/ERN CWA AS THE DRIER AIR ALOFT MOVED OVER LOCATIONS THAT DID NOT SEE SGNFT LLVL DRYING YDAY AFTN. OVER THE W WHERE SFC DEWPTS MIXED OUT AS LO AS 25-30 AT IWD ON SUN AND TEMPS ARE STILL ABV 32 AT MOST SPOTS...THERE IS LTL IF ANY FOG. A MUCH STRONGER SHRTWV IN THE POLAR BRANCH FLOW IS NEAR LK WINNIPEG AND MOVING STEADILY TO THE E. THERE HAVE BEEN SOME SHOWERS AND EVEN SOME LGT STRIKES IN MANITOBA RIGHT UNDER THE STEEPER LAPSE RATES CLOSE TO THE CORE OF THIS DISTURBANCE. BUT SINCE THIS SHRTWV IS CUTOFF FM THE MOISTER AIRMASS TO THE S... THERE IS ONLY A NARROW BAND OF LIGHT SHOWERS ALONG ITS ATTENDANT COLD FNT MOVING THRU NW MN EARLY THIS MRNG. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE FOG EARLY THIS MRNG AND THEN PCPN CHCS LATER TODAY/TNGT AS POLAR BRANCH SHRTWV/ATTENDANT COLD FNT IMPACT UPR MI. TODAY...EXPECT LOCALLY DENSE FOG TO PERSIST EARLY THIS MRNG OVER THE SE HALF OF THE CWA...BUT INCRSG HI CLDS SHOULD LIMIT THE POTENTIAL FOR WDSPRD DENSE FOG. WL ISSUE AN SPS TO ALERT THE PUBLIC TO LOCALLY REDUCED VSBYS. SHRTWV NEAR LK WINNIPEG IS FCST TO MOVE E THRU NW ONTARIO AND DRAG IT ATTENDANT COLD FNT ACRS UPR MI THIS AFTN. SINCE BULK OF DPVA/DEEP LYR QVECTOR CNVGC WL REMAIN TO THE N AND JUST BRUSH THE NRN LAND CWA...SUSPECT ONLY ISOLD-SCT SHOWERS WL ACCOMPANY THE FROPA. ALMOST ALL THE MODELS THAT WERE SHOWING A GREATER INTERACTION BTWN THIS SHRTWV/DEEPER MSTR TO THE S AND SGNFT EXPANSION OF THIS MSTR/SHOWERS INTO UPR MI HAVE RETREATED A BIT FM THIS FCST...A REASONABLE TREND CONSIDERING THE VERY DRY NATURE OF THE 00Z MPX RAOB AND LACK OF SGNFT BACKING OF THE UPR FLOW FM THE W THRU THE DAY. THE 00Z HI RES CNDN MODEL SHOWS THE HEAVIER PCPN OVERSPREADING MOST OF UPR MI ALONG WITH THE MOST UNSTABLE MIXED LYR CAPES AOA 1000 J/KG. FCST SDNGS FM THIS MODEL SHOW FAIRLY IMPRESSIVE MOISTENING THRU THE LOWER TROP WITH SFC DEWPTS RISING TO ARND 55...WHICH DOES NOT SEEM RSNBL IN THE ABSENCE OF A DEEPER SW FLOW. THE 00Z NAM SHOWS MORE MODEST MOISTENING/DESTABILIZATION OVER THE SCENTRL. WL CARRY THE HIER CHC POPS THIS AFTN WHERE THIS MODEL SHOWS THE GREATER INSTABILITY UP TO 700-800 J/KG OVER THE SCNTRL. INCLUDED A SCHC OF TS IN THIS AREA AS WELL GIVEN ARRIVAL OF COLD FNT DURING PEAK HEATING TIME THAT WL PUSH TEMPS WELL ABV NORMAL AGAIN IN THE PRESENCE OF H85 TEMPS NOT FAR FM 10C AND AWAY FM THE MODERATING INFLUENCE OF THE LKS. COOLER AIR WL ARRIVE OVER THE W LATER IN THE DAY FOLLOWING THE FROPA. TNGT...NW FLOW WITH H925 WINDS UP TO 25-35 KTS IN THE WAKE OF THE COLD FROPA WL DRIVE COLDER AIR BACK INTO THE UPR LKS TNGT. MODELS SHOW H85 TEMPS SINKING AS LO AS -7 TO -8C OVER THE W BY 12Z TUE. WHILE THIS INCOMING AIRMASS WL NOT BE COLD ENUF FOR LK EFFECT PCPN...MODELS DO SHOW SOME LLVL MOISTENING BLO STRENGTHENING SUBSIDENCE INVRN ARND H85 UNDER THE LARGE SCALE QVECTOR DVGC LEFT IN THE WAKE OF DEPARTING SHRTWV. GOING FCST SHOWS SOME DRIZZLE/FRZG DRIZZLE OVER THE HIER TERRAIN WITH MOISTENING/INVRN BASE BLO THE DGZ. THIS FCST SEEMS RSNBL...BUT DID ADD SOME FLURRIES AS WELL. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 438 PM EDT SUN APR 20 2014 A SERIES OF FAIRLY ENERGETIC SYSTEMS WILL TRACK ACROSS THE CONUS OVER THE NEXT 7 TO 10 DAYS. GIVEN THE TIME OF YEAR...CAN`T RULE OUT THE POSSIBILITY OF MID/UPPER LEVEL LOWS DEVELOPING/CLOSING OFF AND SLOWING THE PROGRESSION DOWN. IF SO...DEPENDING ON WHERE IT HAPPENS...SIGNIFICANT PCPN COULD BE IN THE OFFING ALONG WITH THE POSSIBILITY OF LATE SEASON SNOW. AT THIS POINT...MEDIUM RANGE GUIDANCE POINTS TOWARD A PROGRESSIVE PATTERN WITH THE FIRST SHORTWAVE TROF PASSING ACROSS THE UPPER LAKES MON NIGHT. THIS WILL BE FOLLOWED BY A MID/UPPER LEVEL RIDGE ARRIVING WED. ON ITS HEELS WILL BE THE NEXT MORE POTENT SHORTWAVE TROF WHICH MOVES ONSHORE OVER THE WRN CONUS TUE. BY THE TIME IT REACHES THE GREAT LAKES LATE IN THE WORK WEEK...THIS SHORTWAVE TROF WILL HAVE INTERACTED WITH A NRN STREAM WAVE DROPPING S THRU CNTRL CANADA. DEPENDING ON WHERE/WHEN THE INTERACTION BTWN THE 2 WAVES OCCURS...PTYPE COULD BECOME MORE OF AN ISSUE DURING THE PRIMARY PUSH OF PCPN ACROSS THE AREA. RIGHT NOW...IT APPEARS RAIN WILL BE THE MAIN PTYPE. FEATURES INVOLVED ARE CERTAINLY FAR ENOUGH OUT IN THE FCST CYCLE FOR IMPORTANT ADJUSTMENTS TO OCCUR. IN ANY EVENT...THE INFUSION OF THE NRN STREAM WAVE WILL RESULT IN A DUMP OF COLDER AIR/BLO NORMAL TEMPS LATE WEEK INTO THE WEEKEND...INCLUDING AT LEAST SOME LIGHT SNOW ON THE BACKSIDE OF THE LATE WEEK SYSTEM. BEYOND THIS 7 DAY FORECAST... THERE ARE HINTS FLOW COULD BECOME QUITE BLOCKY ACROSS CANADA WHICH MAY HOLD COOL AIR IN PLACE ACROSS MUCH OF THE NRN CONUS/SRN CANADA. SO...TEMPS NEXT WEEK ARE MORE LIKELY TO BE IN THE NORMAL TO BLO NORMAL RANGE RATHER THAN ABOVE NORMAL. KEEP IN MIND NORMALS NEXT WEEK ARE GENERALLY 50S N TO LOW/MID 60S S. BEGINNING MON NIGHT...COLD FRONT ASSOCIATED WITH SHORTWAVE PASSING THRU THE UPPER LAKES WILL BE EXITING THE E IN THE EVENING. UNDER CAA REGIME MON NIGHT...NAM/GFS INDICATE SIGNIFICANT LOW-LEVEL MOISTENING...ESPECIALLY IN THE N/NNW WIND UPLSOPE AREAS...WHICH RAISES THE PROSPECT FOR SOME -DZ/-FZDZ TO DEVELOP AS MOISTURE DOES NOT EXTEND TO -10C ISOTHERM. LOW CONFIDENCE IF IT WILL HAPPEN... BUT THE E WOULD BE MOST FAVORED. AFTER SOME MORNING CLOUDS IN CYCLONIC FLOW AND THEN LIKELY A PERIOD OF BKN CU DEVELOPMENT LATE MORNING THRU EARLY AFTN UNDER 850MB THERMAL TROF...SKIES WILL CLEAR IN THE AFTN AS MUCH DRIER AIR MASS SETTLES INTO THE AREA IN ASSOCIATION WITH SFC HIGH PRES RIDGE SHIFTING INTO THE UPPER LAKES. N TO NW GRADIENT WIND AIDED BY LAKE BREEZE COMPONENT WILL LEAD TO A CHILLY DAY ALONG LAKE SUPERIOR WITH HIGH TEMPERATURES IN THE 30S. WELL INLAND...TEMPS SHOULD STILL RISE WELL INTO THE 40S TO AROUND 50F UNDER LATE APR SUNSHINE. IDEAL RADIATIONAL COOLING NIGHT SETS UP TUE NIGHT UNDER SFC HIGH PRES AND CLEAR SKIES. PRECIPITABLE WATER OF 40-60PCT OF NORMAL WILL AID THE COOLING PROCESS. FAVORED THE LOW END OF GUIDANCE... ESPECIALLY WHERE DECENT SNOW COVER WILL STILL EXIST. TRADITIONAL COLD SPOTS MAY SLIP INTO THE TEENS. SFC HIGH PRES SLIPS E WED. ALTHOUGH 06Z GFS/00Z ECMWF SHOW PCPN REACHING WRN UPPER MI LATE IN THE DAY WED ASSOCIATED WITH WEAK LEAD SHORTWAVE CUTTING THRU MID/UPPER RIDGE WELL IN ADVANCE OF THE AFOREMENTIONED LATE WEEK SYSTEM...WILL MAINTAIN DRY WEATHER THRU THE AFTN AS EASTERLY LOW-LEVEL WIND COMPONENT EMANATING FROM DEPARTING SFC HIGH SHOULD HELP HOLD LOW-LEVEL DRY AIR IN PLACE. 12Z RUNS HAVE SLOWED EASTWARD PCPN PROGRESSION...SO DRY FCST SEEMS IN GOOD SHAPE. DESPITE COMPLEXITIES IN THE FLOW REGIME...MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT WITH THE SHORTWAVE TROF MOVING ONSHORE OVER THE W COAST TUE AND REACHING THE GREAT LAKES FRI. WITH PUSH OF STRONGEST WAA/ISENTROPIC ASCENT ARRIVING THU...HIGHEST POPS WILL BE USED AT THAT TIME AS AN AREA OF RAIN WILL LIKELY MOVE ACROSS THE AREA. GEM/ECMWF SHOW 850MB TEMPS HOVERING AROUND 0C WED NIGHT THRU THU ON FRONT SIDE OF SYSTEM...BUT BOUNDARY LAYER SHOULD BE SUFFICIENTLY WARM FOR ONLY RAIN GIVEN THAT IT`S LATE APR. STILL...IT WILL BE SOMETHING TO MONITOR IN THE COMING DAYS DUE TO SOME UNCERTAINTY IN THE NRN STREAM FLOW ACROSS CANADA AND THE INTERACTION IT HAS WITH THE SHORTWAVE MOVING ACROSS THE CONUS. WOULDN`T TAKE MUCH OF SOUTHWARD SHIFT OF SYSTEM TO RESULT IN ANOTHER LATE SEASON SNOW FOR THE W AND N HIGHER TERRAIN. TODAYS 12Z ECMWF HAS TRENDED DEEPER WITH THE MIDLEVEL LOW AS IT MOVES ACROSS THE UPPER LAKES THU NIGHT/FRI. IF VALID...SOME ACCUMULATING SNOW WOULD BE POSSIBLE WITH DEFORMATION PCPN SHIELD IMPACTING WRN AND NRN UPPER MI THU NIGHT/FRI. ANY LINGERING PCPN WILL WIND DOWN/END SAT AS SYSTEM MOVES OFF TO THE E. TEMPS SAT WILL BE WELL BLO NORMAL IN THE 30S N TO LOW/MID 40S SCNTRL. ONLY SLIGHT MODERATION IS EXPECTED SUN AS SFC HIGH PRES RIDGE NOSES INTO THE AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 122 AM EDT MON APR 21 2014 THE BIG FCST CONCERN OVERNIGHT WILL BE FOG...ESPECIALLY AT KSAW WHERE DEWPOINTS REMAIN MOIST (IN THE LOWER 40S). HAVE FOLLOWED MOS GUIDANCE FOR MUCH OF THE TIMING ON THE FOG AND INTENSITY. KIWD MAY NOT SEE MUCH FOG TONIGHT AS LIGHT DOWNSLOPING SOUTHEAST WINDS WILL LIKELY LIMIT FOG POTENTIAL. THE CONCERN AT KCMX IS WHETHER DRIER AIR OVER LAKE SUPERIOR MAY LIMIT FOG POTENTIAL DESPITE WEAK UPSLOPE EAST FLOW DEVELOPING LATE TONIGHT. SINCE THE DEWPOINT DEPRESSION AT KCMX IS ONLY 2F STILL THINK PREVAILING IFR VBSY IS A GOOD BET FOR THE 07-14Z TIME FRAME. KSAW SHOULD HAVE THE BEST OPPORTUNITY TO FALL TO LIFR/PERHAPS VLIFR/BLO LANDING MINS BASED ON LOWER 40S DEWPOINTS AND LIGHT SOUTH-SOUTHEAST UPSLOPE FLOW DEVELOPING OVERNIGHT UNDER GENERALLY CLEAR SKIES. EXPECT THE FOG TO BURN OFF DURING THE MORNING AS MIXING INCREASES AND SOME MID CLOUDS APPROACH TOWARDS AFTERNOON. WINDS WILL SHIFT WESTERLY BEHIND TROUGH/FRONTAL PASSAGE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 424 AM EDT MON APR 21 2014 LIGHT WINDS UNDER 15 KTS THIS MORNING ASSOCIATED WITH WEAK HIGH PRESSURE RIDGE WILL SHIFT TO THE NW LATE TODAY/THIS EVENING FOLLOWING A COLD FRONTAL PASSAGE AND INCREASE UP TO 25-30 KTS TONIGHT AS MUCH COLDER AIR INVADES THE UPPER LAKES. NOT OUT OF THE QUESTION THERE COULD BE SOME GALES OVER PORTIONS OF THE EAST HALF OF THE LAKE UNDER THE SHARPER GRADIENT/STRONGEST LOW LEVEL WINDS. MENTIONED SOME GALE FORCE GUSTS UP TO 35 KTS OVER THE ECENTRAL FOR NOW. THESE STONG WINDS WILL DIMINISH TUE THRU WED AS A HI PRES RIDGE AND WEAKER PRES GRADIENT MOVE OVER THE AREA. AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE PLAINS LATER IN THE WEEK AND THE GRADIENT SHARPENS AGAIN...INCREASING SE WINDS WILL SHIFT TO THE NE. DEPENDING ON THE TRACK AND INTENSITY OF THIS LO...THERE COULD BE AT LEAST A PERIOD OF GALE FORCE WINDS. && .HYDROLOGY... ISSUED AT 1202 AM EDT MON APR 21 2014 HIGHEST SNOW DEPTH REPORTED YESTERDAY MORNING OF 32IN AT MOHAWK WAS ABLE TO DROP DOWN TO 28IN BY LATE EVENING. AT THE OTHER END OF THE SPECTRUM...SEVERAL SITES FROM IWD THROUGH ISQ WERE REPORTING LITTLE TO NO SNOW. TODAY WILL BE ANOTHER DAY OF MELTING...AS HIGH TEMPERATURES JUMP INTO THE 50S AND LOW 60S FOR MUCH OF THE AREA. THE MELT WILL SLOW TUESDAY-TUESDAY NIGHT OVER N UPPER MI AS COLD N-NNW WINDS KEEP TEMPS TOPPING OUT IN THE 30S AND LOW 40S TUESDAY. AS FOR FURTHER OUT...TEMPERATURES WILL RETURN TO NEAR NORMAL VALUES TEMPORARILY WEDNESDAY BEFORE FALLING BACK INTO THE 30S AND 40S THROUGH THE UPCOMING WEEKEND. WILL CONTINUE TO NOTICE SIGNIFICANT STREAM/RIVER RISES OVER THE NEXT FEW DAYS. UNSETTLED WEATHER WILL RETURN FROM THURSDAY THROUGH FRIDAY...ADDING TO THE RUNOFF. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE W HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW PENINSULA WHERE 0.75-1IN OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. WE WILL CONTINUE TO REFINE THE FCST AS THE TIME NEARS. SO FAR THE LOCATIONS EXPERIENCING SIGNIFICANT RISES HAVE BEEN ALSTON/ALSM4/ ON THE STURGEON RIVER...ROCKLAND/RKLM4/ ON THE ONTONAGON RIVER...AND TO A LESSER EXTENT THE HYDE/FRDM4/ ON THE FORD RIVER. WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...ANY RIVER THAT HAS ICE REMAINING ON IT...ESPECIALLY THE ESCANABA RIVER IN DELTA COUNTY...COULD EXPERIENCE AN ICE JAM WITH THE RISING RIVER LEVELS THIS WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR BOTH RIVER LEVELS AND ICE CONDITIONS. ICE JAMS CAN FORM AND BREAK QUICKLY...RESULTING IN RAPIDLY FLUCTUATING RIVER LEVELS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...ROLFSON AVIATION...VOSS/KC MARINE...KC HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS DULUTH MN
710 PM CDT TUE APR 22 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 325 PM CDT TUE APR 22 2014 HIGH PRESSURE OVER THE NORTHLAND WILL BEGIN TO SHIFT TO THE EAST TONIGHT. CLEAR SKIES AND LIGHT WINDS ARE EXPECTED FOR AT LEAST TONIGHT, AND FOR ALL OF THE NIGHT ACROSS THE EASTERN FORECAST AREA. AS FOR THE WESTERN FORECAST AREA, THERE WILL BE INCREASING HIGH CLOUDS FROM THE WEST AS A LOW PRESSURE SYSTEM DEVELOPS IN THE NORTHERN HIGH PLAINS. THE CLEAR SKIES AND LIGHT WINDS WILL PROMOTE RADIATIONAL COOLING. LOW TEMPERATURES SHOULD RANGE FROM THE MID TO UPPER 20S IN THE EASTERN FORECAST AREA TO THE LOW TO MID 30S ACROSS THE WESTERN FORECAST AREA. THERE IS THE POSSIBILITY OF FOG TONIGHT...HOWEVER I AM NOT CONFIDENT AT THIS POINT. THE LOCAL WRF...NAM...AND RAP MODELS ARE SUGGESTING IT IS POSSIBLE ACROSS THE EASTERN FORECAST AREA...ESPECIALLY CLOSER TO LAKE SUPERIOR. THIS IS SOMETHING THE EVENING SHIFT CAN LOOK MORE INTO WHEN IT MORE HIGH RESOLUTION MODEL DATA IS AVAILABLE. WEDNESDAY...A DEEP MID/UPPER LEVEL LOW WILL MOVE EAST FROM THE PACIFIC NW TO NORTHERN MONTANA. SURFACE LOW PRESSURE WILL CONTINUE TO DEVELOP AND ORGANIZE IN THE PLAINS...AND BEGINNING TO BRING INCREASING SE FLOW AND MOISTURE TO THE UPPER MIDWEST. THE LOW LEVEL SE FLOW WILL BEGIN FAIRLY DRY...SO IT WILL LIKELY TAKE SOME TIME FOR THE LOW LEVELS TO SATURATE BEFORE THE NORTHLAND SEES ANY SIGNIFICANT RAINFALL. THE GFS IS FASTER THAN OTHER MODELS AT BRINGING IN THE PCPN INTO THE FORECAST AREA...SO I LEANED MORE ON THE SREF/NAM/GEM/ECMWF. THE INCREASING CLOUD COVER WILL RESULT IN COOLER TEMPERATURES FOR MUCH OF THE NORTHLAND COMPARED TO TODAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 325 PM CDT TUE APR 22 2014 THE BIG CONCERN FOR THE LONG TERM IS THE MAJOR STORM SYSTEM THAT IS EXPECTED TO MOVE THROUGH THE REGION LATE IN THE WEEK. THERE ARE SOME DISTINCT MODEL DIFFERENCES DURING THIS TIME PERIOD...AS THE MODELS ATTEMPT TO PHASE TWO LOW PRESSURE SYSTEMS INTO ONE MAIN LOW OVER THE WESTERN GREAT LAKES. THE UK/EC AND EVEN THE NAM GENERALLY MAINTAIN TWO DISCRETE LOW AREAS...WITH THE GFS AND GEM COMPLETELY PHASING THE DUAL LOW ENERGY INTO ONE LOW. THE IMPACT ON SENSIBLE WEATHER IS NOT SO DRAMATIC...AS ALL OF THE MODELS SUPPORT FAIRLY HIGH TOTAL QPF. BUT THERE ARE DIFFERENCES IN THE THERMAL PROFILES AND OF COURSE IN WINDS. OVERALL...WILL BE A LITTLE CAREFUL ABOUT COMPLETELY PHASING THE TWO SURFACE LOWS...AND FAVORING A SOLUTION A BIT MORE IN LINE WITH THE ECMWF. OF PERHAPS THE MOST CONCERN FOR OUR AREA IS THE CHANCE OF ACCUMULATING SNOWFALL. MODEL RUN SNOW ACCUMULATION VALUES ARE FAIRLY HIGH FOR NORTHEASTERN MN...ESPECIALLY OVER THE TIP OF THE ARROWHEAD...WHERE ALL OF THE MODELS BASICALLY SUPPORT THE POTENTIAL FOR MORE THAN 6 INCHES OF SNOW. AFTER COORDINATING WITH HPC AND THE WINTER WEATHER DESK...THINK THERE IS TIME TO HOLD OFF ON ISSUING A WATCH FOR THE ARROWHEAD DUE TO DIFFERENCES IN THERMAL PROFILES OF FORECAST SOUNDINGS...DIFFERENCES IN HOW THE MODELS ARE HANDLING THE PHASING OF THE TWO LOW STRUCTURE AND QUESTIONS ABOUT THE POTENTIAL FOR SIGNIFICANT MELTING. SPRING SYSTEMS LIKE THIS ARE NOTORIOUSLY DIFFICULT THIS FAR OUT...AS SUBTLE CHANGES IN THE THERMAL PROFILES COULD YIELD DRAMATICALLY DIFFERENT OUTCOMES. AT THIS POINT...NOT COMFORTABLE ISSUING A WATCH FOR THE ARROWHEAD...BUT IT IS SOMETHING WE WILL NEED TO WATCH VERY CLOSELY AND MAY EVENTUALLY NEED A WATCH. FURTHER SOUTH...SOUTH OF THE IRON RANGE...THERE IS ALSO THE POTENTIAL FOR SOME SNOW ACCUMULATION...BUT IT SHOULD GENERALLY BE A SLUSH ACCUMULATION OF MAYBE UP TO A COUPLE INCHES. EVEN FURTHER SOUTH FROM EAST CENTRAL MINNESOTA INTO OUR SOUTHERN TIER OF COUNTIES...THERE SHOULD BE LITTLE TO NO SNOW ACCUMULATION. NO MATTER WHAT...IT WILL BE WET AND POTENTIALLY SNOWY END TO THE WEEK FOR THE CWA. IT SHOULD THEN BE QUIET AND MAINLY DRY FOR THE WEEKEND. WILL ALSO NEED TO WATCH THE SYSTEM FOR LATE IN THE WEEKEND...AND EARLY NEXT WORK WEEK...BUT FOR NOW IT LOOKS LIKE IT MAY NOT TOTALLY GET ITS ACT TOGETHER TO HAVE A MAJOR IMPACT ON OUR WEATHER. THAT MAY CHANGE AS IT IS QUITE A WAYS OUT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 710 PM CDT TUE APR 22 2014 VFR CONDITIONS WILL PREVAIL THROUGH MUCH OF THE PERIOD. AN AREA OF LOW PRESSURE WILL APPROACH THE NORTHLAND TONIGHT INTO WEDNESDAY AND BRING WITH IT THICKENING MID-HIGH CLOUDS LATER TONIGHT/WEDNESDAY MORNING. CLOUDS WILL LOWER FURTHER WEDNESDAY WITH AN AREA OF RAIN MOVING IN FROM THE SOUTHWEST. MVFR CONDITIONS WILL DEVELOP AROUND KBRD IN THE AFTERNOON AS A STEADY RAIN DEVELOPS THERE. MOST OTHER AREAS WILL SEE THE PRECIPITATION HOLD OFF UNTIL WEDNESDAY EVENING. && .PRELIMINARY POINT TEMPS/POPS... DLH 32 45 34 43 / 0 20 80 90 INL 30 54 36 45 / 0 10 80 90 BRD 38 49 41 52 / 10 70 90 70 HYR 28 53 38 50 / 0 50 90 90 ASX 27 48 36 47 / 0 10 80 90 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...GROCHOCINSKI LONG TERM...DAP AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
654 AM CDT MON APR 21 2014 .UPDATE... ISSUED AT 644 AM CDT MON APR 21 2014 UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CDT MON APR 21 2014 MAIN CONCERN IN THE SHORT TERM IS THE CONVECTION CURRENTLY OCCURRING ACROSS THE AREA... AND HOW IT WILL EVOLVE THROUGH THE MORNING HOURS. LATEST SURFACE ANALYSIS SHOWS A TIGHT DEWPOINT GRADIENT FROM WEST CENTRAL MINNESOTA THROUGH WEST CENTRAL WISCONSIN... ACTING AS A WARM FRONT OF SORTS... WITH THE THERMAL GRADIENT A BIT FARTHER NORTH AND ALSO TO THE WEST ALONG THE SURFACE TROUGH. SPC MESOANALYSIS MUCAPE SHOWS VALUES OF 250-500 J/KG COINCIDENT WITH THE AREA OF ACTIVITY CURRENTLY OVER THE AREA... LINING UP FAIRLY WELL WITH THE RAP ANALYZED 850MB THETA-E RIDGE AHEAD OF THE SURFACE FRONT AND SHORTWAVE APPARENT IN WATER VAPOR IMAGERY. THINGS ARE EXPECTED TO CONTINUE TO SHIFT EAST THIS MORNING... WITH MOST OF THE ACTIVITY EAST OF THE FORECAST AREA AFTER 15Z. HOWEVER... UNTIL THAT TIME WE WILL SEE SOME LOCAL DOWNPOURS AND PEA-SIZED HAIL WITH THE STORMS THAT ARE MOVING THROUGH THE AREA. BY 18Z WE SHOULD SEE CLEARING QUICKLY WORKING ITS WAY FROM WEST TO EAST ACROSS THE FORECAST AREA... WITH STRONG NORTHWEST WINDS... PARTICULARLY OVER WEST CENTRAL AND SOUTH CENTRAL MINNESOTA. THE COMBINATION OF STRONG WINDS AND RELATIVE HUMIDITY VALUES IN THE 20S THIS AFTERNOON WILL RESULT IN ELEVATED FIRE DANGER POTENTIAL FOR FROM WEST CENTRAL INTO SOUTH CENTRAL MINNESOTA... SO WILL CONTINUE THE FIRE WEATHER WATCH FOR THAT AREA. HIGH PRESSURE WILL BUILD OVER THE REGION TONIGHT... WITH WINDS QUICKLY DYING OFF DURING THE EVENING HOURS... AND COOLER TEMPERATURES MOVING BACK INTO THE AREA... MAKING FOR LOWS IN THE 30S AND PERHAPS BELOW FREEZING IN OUTLYING AREA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 333 AM CDT MON APR 21 2014 TRENDS IN THE LONG TERM CONTINUE TO INDICATE A FAIRLY ACTIVE MIDWEEK...FOLLOWED BY A COOLING TRNED THAT WILL LAST THROUGH NEXT WEEKEND. HIGH PRESSURE BEGINS THE LONG TERM FOR TUESDAY. IT SHOULD BE A RATHER PLEASNT DAY WITH LIGHT WINDS...AND MILD TEMPERATURES. THE NEXT WESTERN CONUS TROUGH DIGS SOUTHEAST AND BEGINS TO AFFECT THE AREA LATE TUESDAY NIGHT. RETURN FLOW AND LLJ INTENSIFIES OVER THE EASTERN DAKOTAS LATE TUESDAY NIGHT. THIS WILL DEVELOP AT LEAST SOME WIDELY SCATTERED CONVECTION IN THE EASTERN DAKOTAS...SPILLING EAST INTO WEST CENTRAL MN LATE. STEEPER LAPSE RATES MOVE INTO THE WEST DURING THE DAY WEDNESDAY...WITH THE THREAT OF ISOLATED CONVECTION EXPECTED. THE MORNING ACTIVITY WILL SPREAD EAST INTO WESTERN WISCONSIN WITH REDEVELOPMENT AGAIN TO THE WEST INTO THE AFTERNOON. THE BETTER INSTABILITY WORKS EAST WITH TROUGH WEDNESDAY NIGHT INTO THURSDAY. AREA OF STEEP LAPSE RATES LIFT NORTH ACROSS AT LEAST THE SOUTHERN HALF OF THE AREA AHEAD OF THE SURFACE LOW WHICH IS PROGGED TO MOVE SOUTH OF THE CWA...ALONG/NEAR THE MN/IA BORDER. STILL SEE SOME ELEVATED HAIL POSSIBILITIES LATER WEDNESDAY NIGHT AND THURSDAY MORNING. MODEL DISCREPANCIES REMAIN AS TO HOW QUICKLY THE UPPER LOW MOVES EAST OF THE AREA. THE 00Z ECMWF IS MOST PROGRESSIVE WITH THE SYSTEM AND DROPS SOME COLDER AIR SOUTH OVER THE AREA INTO THE WEEKEND. THE 00Z GFS IS SLOWER AND MUCH MORE AMPLIFIED WITH THE SYSTEM. IT EVENTUALLY DROPS 85H TEMPERATURES CLOSE TO MINUS 12C ONCE AGAIN BY SATURDAY MORNING. THIS MAY BE OVERDONE...BUT IT DOES APPEAR WELL BELOW NORMAL TEMPERATURES ARE ONCE AGAIN IN STORE WELL INTO THE WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 644 AM CDT MON APR 21 2014 WITH THE EXCEPTION OF THE ACTIVITY CURRENTLY MOVING THROUGH THE AREA... THE FORECAST PERIOD LOOKS FAIRLY QUIET WITH VFR CONDITIONS. STRONG NORTHWEST WINDS BY LATE THIS MORNING THROUGH THIS AFTERNOON WILL BE THE ONLY OTHER ITEM OF NOTE. LATEST SURFACE ANALYSIS SHOWS COLD FRONT THROUGH ABOUT HALF OF THE AREA... AND CURRENT TRENDS AND LATEST RAP SHOW IT MOVING THROUGH THE REMAINDER OF THE AREA BY THE END OF THE MORNING. THIS WILL WORK TO PUSH THE PCPN OUT AND ALLOW SUNSHINE TO BECOME PREVALENT FROM WEST TO EAST DURING THE MORNING HOURS. THERE ARE SOME LOW CLOUDS TRYING TO DROP SOUTH THROUGH NORTH DAKOTA AT THE CURRENT TIME... AND INDICATIONS ARE THAT THEY SHOULD MAKE IT TO NEAR KAXN BEFORE THEY ERODE AND STOP THEIR FORWARD PROGRESS. OTHERWISE... LOOK FOR SURFACE RIDGING TO STEADILY BUILD LATER TODAY INTO TONIGHT... WHICH WILL WORK TO KNOCK DOWN THE WINDS DURING THE EVENING HOURS. KMSP...MAIN UNCERTAINTY IS IN THE FIRST HOUR OR TWO OF THE FORECAST AND WHETHER ANY ADDITIONAL SHRA AND/OR THUNDER MANAGES TO IMPACT THE AREA. THERE ARE A COUPLE OF LONE SHRA STILL TO THE WEST RIGHT ALONG THE EXTENSION OF THE UPPER WAVE AND A SECONDARY SURFACE BOUNDARY ASSOCIATED WITH THE COLD FRONT. ALLOWED FOR A VCSH THROUGH 1330Z TO ACCOUNT FOR THIS POSSIBILITY. OTHERWISE... WE SHOULD SEE VFR CONDITIONS WITH GENERALLY SKC AFTER 16Z. NORTHWEST WINDS WILL GUST AOA 25 KT FOR MUCH OF THE AFTERNOON BEFORE DYING OFF THIS EVENING AS THE SURFACE HIGH MOVES INTO THE AREA. /OUTLOOK FOR KMSP/ TUESDAY AFTERNOON...VFR. VARIABLE WIND 5 KT OR LESS BECOMING SOUTHEAST 5 TO 10 KT. TUESDAY NIGHT AND WEDNESDAY...MVFR CEILINGS EXPECTED WITH MVFR VISIBILITIES POSSIBLE ALONG WITH A CHANCE OF RAIN. SOUTHEAST WIND 10 TO 20 KT WITH HIGHER GUSTS. WEDNESDAY NIGHT...MVFR CEILINGS AND VISIBILITIES EXPECTED... IFR POSSIBLE WITH RAIN LIKELY. SOUTHEAST WIND 15 TO 20 KT. THURSDAY...MVFR CEILINGS AND VISIBILITIES EXPECTED EARLY WITH A CHANCE OF RAIN. SOUTH WIND 10 TO 20 KT SHIFTING WEST. THURSDAY NIGHT...VFR. WEST WIND 5 TO 15 KT. FRIDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF RAIN. WEST WIND 5 TO 15 KT BECOMING NORTHWEST. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR MNZ047-054>056-064-065-073>075-082-083-091-092. WI...NONE. && $$ UPDATE... SHORT TERM...TRH LONG TERM...DWE AVIATION...
AREA FORECAST DISCUSSION
NWS BILLINGS MT
909 PM MDT TUE APR 22 2014 .UPDATE... FORECAST IN GOOD SHAPE TONIGHT AND ONLY MADE A FEW MINOR TWEAKS. MAIN UPDATE WAS TO THE AVIATION DISCUSSION. COLD FRONT HAS MOVED THROUGH LIVINGSTON AND WILL CONTINUE ADVANCING EASTWARD OVERNIGHT. THE FRONT IS EXPECTED TO REACH BILLINGS BY 06Z AND MILES CITY AROUND 12Z. STILL EXPECTING SCATTERED SHOWERS AND AN ISOLATE THUNDERSTORM WITH THE FRONT FROM MAINLY FROM BILLINGS WEST BEFORE MIDNIGHT. HAVE REMOVED THUNDER OVER SOUTHEAST MONTANA FOR THE REST OF THE EVENING AS FRONT WILL NOT REACH THAT AREA UNTIL LATE TONIGHT. THIS IS DEPICTED WELL WITH THE HRRR SHOWING CONVECTION MOVING INTO SOUTHEAST MONTANA AFTER 09Z TONIGHT. RICHMOND && .SHORT TERM...VALID FOR WED AND THU... ACTIVE WEATHER PATTERN KICKS IN TONIGHT AS WESTERN TROUGH MOVES INTO THE ROCKIES. OUR MAIN CONCERNS FOR THE FORECAST AT THIS TIME OUR PRIMARILY WIND RELATED. THE MOUNTAINS WILL SEE SOME PERIODS OF RIAN AND SNOW WITH GENERALLY LIGHT ACCUMULATIONS AS THE TROUGH MOVES OVER US THE NEXT 36 HOURS...AND ANY PRECIPITATION AT THE LOWER ELEVATIONS WILL BE SCATTERED WITH AMOUNTS LIMITED DUE TO DOWNSLOPE FLOW. QUITE A BIT OF PACIFIC MOISTURE/INSTABILITY STREAMING OUT IN FRONT OF TROUGH WILL IMPACT AREAS MAINLY JUST TO OUR WEST FROM THE GALLATIN NORTHWARD LATE TODAY. THAT SAID...THE UPPER TROUGH HAS SOME GOOD DIFFLUENCE OUT IN FRONT OF IT WHICH MAY HELP SPREAD A FEW SHOWERS AND STRAY THUNDERSTORM FURTHER EAST INTO OUR FORECAST AREA. WE COULD SEE A FEW CELLS TURN SEVERE OVER PARK COUNTY UP TO WHEATLAND WITH SOME WIND GUSTS OVER 50 KTS THANKS TO STEEP LAPSE RATES AND SHEAR PROFILES. WOULD EXPECT THIS MAINLY BETWEEN 00Z AND 04Z. NEGATIVE TILT TROUGH THEN CONSISTENTLY PROGGED TO COME ACROSS OUR REGION TONIGHT INTO WEDNESDAY WITH THE BEST UPPER SUPPORT SLIDING NORTH/NORTHEAST OF OUR FORECAST AREA. HOWEVER... SURFACE PRESSURE RISES AND WIND SWITCH SHOW GOOD PUNCH ACROSS SOUTHERN MONTANA...AND COME THROUGH BILLINGS GENERALLY AROUND 06Z GIVE OR TAKE AN HOUR. WIND SPEEDS AT 850-700MB ARE NOT TERRIBLY IMPRESSIVE...BUT PRESSURE RISES ON THE ORDER OF 2MB AN HOUR WITH STRONG FRONTOGENESIS IMPLY A THREAT OF SOME STRONG WIND IN FAVORABLE AREAS. WE WILL LIKELY HANDLE THIS WITH SPECIAL WEATHER STATEMENTS AS NECESSARY AS FRONT MOVES THROUGH THE AREA. MODELS CONSISTENTLY DEVELOP POST FRONTAL BAND OF QPF LATE TONIGHT INTO WEDNESDAY MORNING. WILL KEEP POPS HIGHEST ON THE PLAINS DURING THIS TIME FRAME. WEDNESDAY...SHOWERS LINGER OVER THE REGION...BUT LOWER ELEVATIONS NEAR THE MOUNTAINS WILL SEE DOWNSLOPE FLOW AND LITTLE PRECIPITATION. MAIN IMPACT WILL LIKELY BE WIND WITH GOOD MIXING AND SOME COLD AIR ADVECTION. GUIDANCE IS STILL INSINUATING SOME STRONG WINDS IN THE LIVINGSTON AND BIG TIMBER VICINITIES...AND POSSIBLY HARLOWTON AND COLUMBUS. I AM TEMPTED TO ISSUE A WIND ADVISORY FOR THE LIVINGSTON TO BIG TIMBER CORRIDOR. HOWEVER...GUIDANCE HAS TRENDED SOMEWHAT DOWN ON THE 12Z CYCLE RUNS. DO NOT WANT TO HANDCUFF US WITH A WIND HIGHLIGHT THAT IS BORDERLINE AND TRENDING DOWN. WILL THEREFORE DEFER TO NEXT COUPLE OF SHIFTS FOR ACTING ON POSSIBLE WIND ADVISORY FOR LIVINGSTON TO BIG TIMBER VICINITY FOR LATTER HALF OF TOMORROW. WE WILL CONTINUE TO EMPHASIZE WIND THREATS IN WEATHER STORIES AND HAZARDOUS WEATHER OUTLOOK PRODUCTS. BT .LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE... EXTENDED MODELS REMAIN IN GOOD AGREEMENT IN THE OVERALL LARGE SCALE PATTERN BUT CONTINUE TO DIFFER IN SMALLER SCALE FEATURES SUCH AS TEMPERATURES AND AMOUNT AND TYPE OF PRECIP. LARGE TROUGH AND UPPER LOW MOVE ONTO THE CALIFORNIA COAST FRIDAY AND THIS WILL ALLOW FOR RIDGING TO BUILD BRIEFLY ACROSS OUR FORECAST AREA. THE UPPER LOW MOVES EAST INTO THE FOUR CORNERS REGION SATURDAY RESULTING IN A SOUTHERLY AND SOMEWHAT DIFFLUENT FLOW ALOFT ACROSS SOUTHERN MONTANA/NORTHERN WYOMING. A DISTURBANCE WITHIN THIS FLOW MOVES ACROSS THE AREA SATURDAY BRINGING SCATTERED SHOWERS TO THE AREA AND POSSIBLY AN ISOLATED THUNDERSTORM. A SURFACE LOW MOVES ACROSS THE MONTANA/WYOMING BORDER DURING THE DAY SATURDAY BRINGING WARM SOUTHEAST WINDS TO OUR EASTERN ZONES WHILE DRAGGING A COLD FRONT ACROSS OUR CENTRAL AND WESTERN AREAS RESULTING IN GUSTY NORTHWEST WINDS BEHIND THE FRONT. AN INVERTED TROUGH SETS UP SATURDAY NIGHT INTO SUNDAY ACROSS OUR EASTERN AREAS. PRECIP AMOUNTS AND TYPE ARE A BIT UNCERTAIN BUT IT LOOKS LIKE A BRIEF PERIOD OF UPSLOPE FLOW WILL BE LIKELY FOR THE RED LODGE FOOTHILLS SATURDAY NIGHT WITH TEMPERATURES COLD ENOUGH FOR SNOW INTO SUNDAY MORNING. HOWEVER..SURFACE WINDS AND ALOFT QUICKLY BECOME WESTERLY RESULTING IN MORE OF A DOWNSLOPE PATTERN FOR THE DAY SUNDAY. MODELS THEN SHIFT THE FOCUS OF THE PRECIP MAINLY TO THE NORTH AND EAST OF BILLINGS FOR THE DAY SUNDAY. THE SURFACE LOW MOVES INTO SOUTH DAKOTA AND STRENGTHENS RESULTING IN VERY TIGHT PRESSURE GRADIENTS ACROSS SOUTHEAST MONTANA. THIS LOW WILL BRING GUSTY NORTH TO NORTHWEST WINDS TO OUR AREA ALONG WITH WRAP-AROUND MOISTURE FOR THE DAY SUNDAY. BEST LOCATIONS FOR THE HEAVIER PRECIP LOOK TO BE AREAS NORTH AND EAST OF BILLINGS. BOTH THE GFS AND ECMWF DIFFER QUITE A BIT WITH TEMPERATURES WITH THE ECMWF BEING THE COLDER OF THE TWO AS THE LATEST GFS HAS COME IN 10 DEGREES WARMER THAN ITS PREVIOUS CYCLE. AS A RESULT...MADE VERY LITTLE IN THE WAY OF CHANGES TO THE INHERITED FORECAST AND KEPT TEMPERATURES WELL BELOW NORMAL. HOOLEY && .AVIATION... A STRONG COLD FRONT CURRENTLY MOVING THROUGH THE KLVM AREA WILL PASS THROUGH THE KBIL AREA BY 07Z AND WILL SLIDE THROUGH THE KSHR AND KMLS AREAS BETWEEN 09Z AND 12Z. THE FRONT WILL BE ACCOMPANIED BY WIDELY SCATTERED SHOWERS AND...POTENTIALLY...A FEW THUNDERSTORMS. WEST TO NORTHWEST WIND GUSTS OF 35-50 MPH ARE POSSIBLE WITH THE FRONT. VERY GUSTY WEST TO NORTHWEST WINDS WILL CONTINUE ACROSS THE ENTIRE REGION WEDNESDAY. STC && .PRELIMINARY POINT TEMP/POPS... WED THU FRI SAT SUN MON TUE ----------------------------------------------------------- BIL 044/057 036/061 038/060 039/052 037/044 032/052 036/057 62/W 22/W 22/W 44/W 66/O 32/W 22/W LVM 037/051 034/059 035/061 035/052 036/050 030/056 032/062 63/W 33/W 23/W 46/W 66/O 32/W 23/W HDN 044/060 034/062 035/061 037/058 035/046 031/052 032/058 53/W 31/N 22/W 44/W 66/O 42/W 22/W MLS 047/060 036/059 036/057 037/047 035/042 029/049 028/049 44/W 32/W 11/B 66/W 77/O 74/W 21/B 4BQ 048/060 034/061 035/056 034/054 034/047 029/050 028/049 33/W 22/W 11/B 44/W 66/O 63/W 31/B BHK 047/060 033/057 033/053 033/045 030/039 026/045 025/046 33/T 22/W 11/B 46/W 67/O 74/W 21/B SHR 042/056 031/060 035/063 038/062 038/047 033/051 032/053 33/W 22/W 22/W 44/W 66/R 43/W 22/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
824 PM CDT TUE APR 22 2014 .UPDATE... ISSUED AT 824 PM CDT TUE APR 22 2014 UPDATE INCLUDED FRESHENING UP CLOUD COVER ACROSS THE AREA FOR TONIGHT. OTHERWISE...FORECAST LOOKS ON TRACK WITH ISOLATED SHOWERS AND THUNDERSTORMS EXPECTED TONIGHT. CURRENTLY...ONLY A FEW SHOWERS/THUNDERSTORMS EXIST ACROSS THE NORTHWEST. LATE TONIGHT...THE POSSIBILITY EXISTS FOR ACTIVITY INCREASING IN THE NORTHEAST IN RESPONSE TO THE LOW LEVEL JET. THE LATEST RAP HAS 400-700 J/KG OF MUCAPE IN THE NORTHEAST LATE. WILL WAIT FOR LATEST NAM BEFORE MAKING CHANGES TO PRECIP FORECAST. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 400 PM CDT TUE APR 22 2014 AT 20Z WATER VAPOR IMAGERY SHOWED AN AMPLIFIED PATTERN IN THE UPPER LEVELS WITH A TROUGH OVER THE EASTERN CONUS...RIDGING OVER THE PLAINS...AND A DEEP TROUGH OVER THE WEST COAST. A GOOD FETCH OF MID AND HIGH LEVEL MOISTURE WAS SEEN AHEAD OF THE TROUGH WITH QUITE A BIT OF CLOUD COVER MOVING INTO THE CENTRAL PLAINS. AT THE SURFACE...A BROAD AREA OF LOW PRESSURE DEVELOPED ON THE LEE SIDE OF THE ROCKIES THROUGH THE DAY WHICH TIGHTENED THE PRESSURE GRADIENT ACROSS NEBRASKA. THIS BROUGHT BREEZY SOUTHERLY WINDS TO THE ENTIRETY OF THE FORECAST AREA THROUGH THE DAY WITH FREQUENT SPEEDS OF 25 MPH WITH GUSTS TO 35 MPH. THIS SOUTHERLY FLOW BROUGHT WARM AIR AND MOISTURE NORTHWARD THROUGH THE DAY...WITH HIGHS INTO THE 70S FOR MUCH OF THE AREA...WHILE DEW POINTS INCREASED INTO THE 40S IN PARTS OF THE PANHANDLE. EVEN WITH THE INCREASE IN DEW POINTS...THE BOUNDARY LAYER REMAINS VERY DRY. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS HAD BEEN DEVELOPING OVER THE PANHANDLE AND NORTHEAST COLORADO THIS AFTERNOON...BUT DUE TO THE DRY AIR...CLOUD BASES WERE AT OR ABOVE 10K FEET. FOR THE REMAINDER OF THE AFTERNOON...SPC MESOANALYSIS SHOWED AREAS OVER THE PANHANDLE HAD BUILT UP TO 500 J/KG MUCAPE. WITH SUFFICIENT LIFT ONGOING ACROSS THE AREA AND SOME INSTABILITY...EXPECT THE SHOWER AND THUNDERSTORM ACTIVITY TO CONTINUE...AND WILL SLOWLY MAKE AN EASTWARD PROGRESSION INTO THIS EVENING. FORECAST MODELS SHOW THAT AS THE ENTIRE SYSTEM PROGRESSES EAST THIS EVENING AND OVERNIGHT SOME INSTABILITY IN THE MID LEVELS WILL MIGRATE EAST ACROSS THE FORECAST AREA. THE AMOUNT OF INSTABILITY WILL BE QUITE WEAK THOUGH...WITH 100-200 J/KG. WITH THE LOSS OF DAYTIME HEATING...AND WITH THE WEAKENING INSTABILITY EXPECT ANY ACTIVITY TO DIMINISH THIS EVENING AS IT MOVES EAST. THE ONE THING TO WATCH WILL BE IF THE INCREASE OF THE LOW LEVEL JET TONIGHT WILL BE ENOUGH TO KEEP ACTIVITY GOING. AT THIS TIME...WITH THE AMOUNT OF DRY AIR ACROSS THE AREA...DON/T THINK THE LLJ WILL BE ENOUGH TO OVERCOME THE DRY AIR AND DON/T EXPECT MUCH FOR PRECIPITATION IN THE OVERNIGHT HOURS. WINDS WILL STAY STRONG OVERNIGHT AS THE PRESSURE GRADIENT STAYS TIGHT. THE STRONG WINDS WILL KEEP TEMPERATURES FROM DROPPING TONIGHT...SO LOOKING AT LOWS IN THE UPPER 40S AND 50S. ON WEDNESDAY...THE UPPER LEVEL TROUGH WILL LIFT NORTHEAST WHICH WILL PUSH A COLD FRONT ACROSS THE FORECAST AREA BY THE END OF THE DAY. WINDS WILL STAY STRONG AHEAD OF THE FRONT...WHICH BY 18Z LOOKS TO BE ROUGHLY FROM KMCK TO KONL. THERE COULD BE A PERIOD OF TIME WHEN WINDS APPROACH WIND ADVISORY CRITERIA OVER THE NORTHEAST PART OF THE FORECAST AREA. THE PERIOD OF THE HIGHEST WINDS WOULD BE FROM AROUND 06Z TO 15Z...BUT WITH IT BEING IN AN AREA OF WARM AIR ADVECTION AND NOT SUBSIDENT AIR...AND ALSO IT BEING IN THE OVERNIGHT HOURS...DON/T KNOW IF THE STRONGEST WINDS WILL BE ABLE TO MAKE IT TO THE SURFACE. THEN IN THE AFTERNOON...MOISTURE WILL POOL AHEAD OF THE FRONT WITH DEW POINTS RISING UP AROUND 50 OR HIGHER. STORMS SHOULD DEVELOP ALONG AND AHEAD OF THE FRONT LATER IN THE AFTERNOON...AND THE PLACEMENT OF THE FRONT WILL DEPEND WHAT AREAS SEE RAINFALL. DID PUSH CHANCES EAST SLIGHTLY...BUT THINK THE STORMS MAY SKIRT THE EASTERN PART OF THE FORECAST AREA. WHEREVER STORMS DO FORM...THEY WILL LIKELY BE STRONG TO EVEN SEVERE AS STRONGER INSTABILITY IS EXPECTED...ALONG WITH STRONG DEEP LEVEL SHEAR AS THE SYSTEM IS QUITE DYNAMIC. WILL BE WATCHING THESE CHANCES CLOSELY OVER THE NEXT 18 TO 24 HOURS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 400 PM CDT TUE APR 22 2014 INITIAL UPPER PV ANOMALY ROTATING ACROSS MT THROUGH THE NEGATIVELY TILTED UPPER LOW WILL ENHANCE CONVERGENCE ALONG THE WARM FRONT LOCATED ACROSS THE UPPER MIDWEST AND NORTHERN PLAINS EARLY...BUT AS THE NEXT ANOMALY MOVES THROUGH THE LONG WAVE TROUGH AS IT PROGRESSES EWD IT WILL ENHANCE CONVERGENCE ALONG THE SWD ADVANCING COLD FRONT ACROSS NEBRASKA WED NIGHT...AND ALONG THE DRYLINE IN WRN KS SWD INTO WEST TX. BY WED NIGHT THE FRONT WILL BE THROUGH MOST OF THE LBF CWA AND WILL TREND THE PRECIP CHCS EWD THROUGH EARLY MORNING...THEN DRY WHICH THE CURRENT GFCST HAS HANDLED WELL. UPPER LOW THEN MOVES INTO THE GREAT LAKES REGION AS TRANSITORY RIDGING MOVES INTO THE CENTRAL ROCKIES. AS THIS OCCURS WESTERLY DOWNSLOPE WINDS WILL REMAIN IN THE BREEZY CATEGORY WITH VERY DRY LOW LEVELS REMAINING. THIS WILL MEAN ANOTHER DAY NEAR CRITICAL FIRE WEATHER CONDITIONS...THOUGH AT THIS TIME WINDS SHOULD REMAIN JUST BELOW CRITERIA THOUGH RH VALUES WILL DROP IN TO THE TEENS IN PORTIONS OF THE SOUTHEAST PANHANDLE INTO SOUTHWEST NEBRASKA. DESPITE THE AREA NEING IN A POST-FRONTAL ENVIRONMENT TEMPS WILL REACH ABOVE AVERAGE IN MOST LOCATIONS UNDER FULL SUN. DRY CONDITIONS WILL PREVAIL INTO FRIDAY AS WELL AS TRANSITORY RIDGE MOVES EAST INTO THE PLAINS. NEXT HIGH AMPLITUDE UPPER LOW MOVES ONSHORE OVER CA FRIDAY NIGHT. BEYOND THIS PERIOD MODEL HAVE VARYING SOLUTIONS TO HOW THIS NEXT SIGNIFICANT WEATHER MAKER EVOLVES. THE 22.12Z RUN OF THE ECMWF HAS SIGNIFICANT DIFFERENCES FROM THE 22.00Z RUN...MOVING THE WARM FRONT MUCH FURTHER NORTH WITH THE LATEST RUN...LOCATED OVER NRN NEB INTO SRM SD. THE POSITION OF THIS WARM FRONT IS SIGNIFICANT BECAUSE WITH THE SYSTEM EVOLVING TO BECOME NEGATIVELY TILTED OVER TIME AS ALL MODELS DO...THE LEAD UPPER PV ANOMALY WITH ENHANCE CONVERGENCE ALONG THE WARM FRONT INITIALLY AND WITH THE POTENTIAL FOR GOOD LOWER LEVEL SHEAR ALONG AND NORTH OF THE WARM FRONT...POTENTIAL FOR SEVERE WEATHER...BOTH AMOUNT AND TYPE OF SEVERE...RESTS HEAVILY WITH THE POSITION OF THIS WARM FRONT. GFS POSITIONS THE WARM FRONT IN KS...FURTHER SOUTH THAN THE ECMWF AND SIMILAR TO THE 22.12Z RUN OF THE CANADIAN MODEL. SEVERE WEATHER WILL BE A DISTINCT POSSIBILITY IN THE PLAINS THIS WEEKEND...THOUGH THE DETAILS OF WHICH WILL HAVE TO BE IRONED OUT IN THE NEXT FEW DAYS. MODELS THEN CONTINUE TO CUT OFF THE UPPER LOW FROM THE MAIN FLOW AND REDEVELOP IT ACROSS THE MID MISSISSIPPI VALLEY IN SOME FASHION...BUT AGAIN TIMING AND LOCATION DIFFERENCES ARE SIGNIFICANT BUT WILL LIKELY KEEP THE AREA UNSETTLED...COOLER THAN AVERAGE AND BETTER CHANCES FOR PRECIP...INTO THE FIRST PART OF NEXT WEEK. ALONG WITH THE POSITION DIFFERENCES ARE SIGNIFICANT TEMPERATURE DIFFERENCES WITH THE ECMWF BEING MUCH COLDER. THIS WILL ALSO LEAD TO A LOW CONFIDENCE IN PRECIPITATION TYPE FOR THE OVERNIGHT PERIODS SUNDAY NIGHT INTO MONDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 642 PM CDT TUE APR 22 2014 LATEST TAF ISSUANCE HIGHLIGHTS WINDS PRIMARILY. GUSTY SOUTHERLY WINDS WILL CONTINUE TONIGHT AT THE TERMINALS...SHIFTING TO THE NORTHWEST EARLY IN THE AFTERNOON TOMORROW WITH THE PASSAGE OF A COLD FRONT. THUNDERSTORM CHANCES INCREASE THIS EVENING...BUT BELIEVE LIKELIHOOD OF A TS NEAR A TERMINAL IS VERY LOW. TOMORROW....A FEW THUNDERSTORMS ARE POSSIBLE...BUT WILL KEEP OUT OF FORECAST AT THIS TIME DUE TO LOW CONFIDENCE. THE CURRENT THINKING IS THAT THE FRONT WILL BE TO THE EAST OF KLBF AND KVTN BY THE TIME SURFACE BASED THUNDERSTORMS BEGIN. HOWEVER...THERE IS A CHANCE THAT THE FRONT WILL BE SLOW ENOUGH AT KLBF TO FAVOR A THUNDERSTORM NEAR THE TERMINAL EARLY IN THE AFTERNOON. WILL BE LOOKING CLOSELY AT THE NEW MODEL DATA THIS EVENING FOR FRONT TIMING. && .FIRE WEATHER... ISSUED AT 433 PM CDT TUE APR 22 2014 FIRE WEATHER CONCERNS WILL HEIGHTEN ON WEDNESDAY BEHIND A COLD FRONT AS DRY AIR PUSHES INTO THE AREA...ALONG WITH BREEZY WEST TO NORTHWEST WINDS. AT THIS TIME...MINIMUM RELATIVE HUMIDITY IS EXPECTED TO BE 15 TO 25 PERCENT WITH WINDS BLOWING AT 15 TO 25 MPH. THEN ON THURSDAY...DRY AIR WILL FILTER INTO THE AREA AS DEW POINTS LOOK TO FALL INTO THE TEENS. TEMPERATURES IN THE 60S TO LOW 70S WILL EQUATE TO RELATIVE HUMIDITY DROPPING TO NEAR 15 PERCENT. WINDS WILL BE BREEZY OUT OF THE WEST TO NORTHWEST...BUT THERE IS UNCERTAINTY TO HOW STRONG THEY WILL GET. BOTH DAYS ARE LOOKING TO HAVE NEAR HIGH FIRE WEATHER CONDITIONS...BUT MAY STAY JUST UNDER CRITICAL LEVELS. WILL BE CLOSELY WATCHING THIS IN THE FORECAST THROUGH THURSDAY. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KNUTSVIG SHORT TERM...BROOKS LONG TERM...JWS AVIATION...KNUTSVIG FIRE WEATHER...BROOKS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
643 PM CDT TUE APR 22 2014 .SHORT TERM...(TONIGHT THROUGH FRIDAY) ISSUED AT 330 PM CDT TUE APR 22 2014 MAIN FORECAST CONCERN WILL BE CENTERED AROUND THUNDERSTORM CHANCES THROUGH THURSDAY MORNING. MID/UPPER LEVEL TROUGH AXIS EXTENDS ACROSS THE INTERMOUNTAIN WEST WITH IMPRESSIVE 130M HEIGHT FALLS OUT AHEAD OF IT. THIS TROUGH WILL CONTINUE TO MOVE EAST AND AHEAD OF IT...A DEEPENING LEE SIDE SFC LOW WILL EXTEND ACROSS THE HIGH PLAINS BY 12Z WED. AHEAD OF ALL OF THIS...STRONG LOW LEVEL SOUTHERLY FLOW WILL BRING BOTH WARM AND MOIST AIR ADVECTION INTO THE REGION. AN FEW RADAR RETURNS ARE SHOWING UP UNDER THE ACCAS FIELD OVER CENTRAL NEBRASKA THIS AFTERNOON. THE HRRR HAS PICKED UP ON THIS BUT WITH LITTLE UPPER LEVEL SUPPORT IN THE AREA JUST YET...THINK THESE WILL FADE AS THEY APPROACH A MUCH DRIER AIRMASS THIS EVENING. NOCTURNAL 850MB WINDS ON THE ORDER OF 50-60KTS ARE FORECAST OVERNIGHT WHICH WILL HELP ADVECT +8 TO +10C DEWPOINTS INTO THE AREA BY WED AFTERNOON. WILL CONTINUE OVERNIGHT/EARLY MORNING TSTM CHANCES IN ASSOCIATION WITH THE STRENGTHENING LLVL JET. A TIGHTENING SURFACE PRESSURE GRADIENT BETWEEN THE RETREATING HIGH PRESSURE CURRENTLY OVERHEAD NOW AND THE APPROACHING HIGH PLAINS LOW WILL BRING QUITE GUSTY WINDS TO THE AREA WED MORNING AND THROUGH THE EARLY AFTERNOON. WITH COORDINATION FROM SURROUNDING OFFICES...WILL HOIST A WIND ADVISORY FOR PORTIONS OF OUR WEST AND NORTH FROM 15-21Z. EXPECT A LULL IN TSTM ACTIVITY DURING THE LATE MORNING/EARLY AFTERNOON HOURS WEDNESDAY. THE SFC LOW WILL BE ENTERING INTO WESTERN KANSAS BY 00Z THU WITH COLD FRONT PUSHING THROUGH CENTRAL NEBRASKA. THE GREATEST INSTABILITY WILL EXIST OVER NORTH CENTRAL KANSAS AND SOUTH CENTRAL NEBRASKA AT THIS TIME WITH BULK 0-6KM SHEAR ON THE ORDER OF 50KTS. CONVECTION IS LIKELY TO DEVELOP ALONG/AHEAD OF THE COLD FRONT AND SPREAD EAST THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS WITH LARGE HAIL AND DAMAGING WINDS AS THE PRIMARY HAZARDS. PW`S BY EARLY EVENING DO INCREASE TO AROUND 1.50" SO THE POTENTIAL EXISTS FOR SOME HEAVIER RAINFALL AMOUNTS. THE UPPER TROUGH IS FORECAST TO SWING THROUGH CENTRAL NEB BY 12Z THURSDAY WITH THE SFC COLD FRONT WELL INTO IOWA BY THAT TIME. LINGERING POST FRONTAL PCPN IS QUITE POSSIBLE IN OUR EASTERN COUNTIES IN THE MORNING. BROAD/WEAK UPPER RIDGING WILL MOVE OVERHEAD ON FRIDAY WITH STRONG SOUTHERLY FLOW SO WE SHOULD BE ABLE TO WARM INTO THE LOW 70S FRIDAY. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 PM CDT TUE APR 22 2014 GLOBAL MODELS ARE CONSISTENT IN MOVING A TROUGH ACROSS THE ROCKIES AND INTO THE CENTRAL PLAINS THIS WEEKEND. THE MODELS DIVERGE TO SOME DEGREE AS TO HOW QUICKLY TO MOVE THE TROUGH OUT OF THE AREA WITH LITTLE IN THE WAY OF AN UPSTREAM KICKER. THE 00Z ECMWF IS HOLDING ONTO THIS TROUGH INTO THE DAY ON MONDAY AS THE SLOWEST SOLUTION. AHEAD OF THE SYSTEM MODIFIED GULF AIR WILL BE ADVANCING NORTHWARD ON SATURDAY. MOST OF THE DAY ON SATURDAY SHOULD BE DRY BUT A COLD FRONT WILL MOVE INTO NORTHEAST NEBRASKA BY AFTERNOON AND THIS COULD BE THE IMPETUS OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS BY AFTERNOON. AS LARGER-SCALE FORCING INCREASES ON SATURDAY NIGHT...ALONG WITH STRONGER LOW LEVEL WARM-AIR ADVECTION WE SHOULD SEE AN INCREASE IN THE AREAL EXTENT OF THE PRECIP...AND LIKELY POPS APPEAR WARRANTED AT THIS TIME. THE 00Z GFS/GEM WOULD THEN SHIFT THIS FORCING/PRECIP SOUTH OF THE AREA BY SUNDAY NIGHT WHILE THE ECMWF WOULD CONTINUE SOME THREAT INTO MONDAY. ALTHOUGH THE SLOWER SOLUTION OF THE ECMWF ISN`T OUT OF THE QUESTION...GIVEN THE LIMITED SUPPORT WILL CONT WITH A DRY FORECAST FOR SUNDAY NIGHT THROUGH TUESDAY. TEMPERATURES WILL WARM INTO THE 70S FOR MOST AREAS ON SATURDAY AHEAD OF THE COLD FRONT...BUT WITH THE PRECIP AND CAA ON SUNDAY TEMPERATURES WILL LIKELY HOLD IN THE 60S. TEMPERATURES SHOULD BE ON THE INCREASE FOR MON/TUE AS A WESTERN US RIDGE DEVELOPS EAST INTO THE CENTRAL US. && .AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 624 PM CDT TUE APR 22 2014 SFC PRES GRADIENT EXPECTED TO RELAX OVER ERN NEB OVERNIGHT. BUT WITH LLVL JET RAMPING UP...LLWS WILL BE AN ISSUE AT ALL TERMINALS BTWN 06Z-12Z WED MORNING. WED MORNING/AFTN...SFC LOW DEEPENING OVER THE WRN DAKOTAS WILL TIGHTEN PRES GRADIENT OVER ERN NEB RESULTING IN SLY WINDS GUSTING 25-35KT. OTHERWISE EXPECT VFR CIGS TO PREVAIL THRU THE FCST PD. AT KOMA...HAVE OPTED TO GO WITH TEMPO GROUP EARLY WED MORNING IN ANTICIPATION OF TSRA DEVELOPING. EXPECT ANY ACTIVITY THOUGH WILL QUICKLY SHIFT EAST INTO WRN IA BY LATE WED MORNING. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY FROM 10 AM TO 4 PM CDT WEDNESDAY FOR NEZ011-012- 015>018-030>034-042>044-050-051-065-066-078-088-089. IA...WIND ADVISORY FROM 10 AM TO 4 PM CDT WEDNESDAY FOR IAZ043. && $$ SHORT TERM...KERN LONG TERM...MILLER AVIATION...DEE
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1223 AM CDT MON APR 21 2014 .UPDATE... ISSUED AT 1217 AM CDT MON APR 21 2014 JUST A SHORT UPDATE EARLIER TO ADJUST PRECIPITATION CHANCES FOR THE REGION OVERNIGHT. ONE AREA WILL LINGER OVER NORTHERN KANSAS WHERE THE MID LEVEL LOW WILL SLOWING CHURN EAST/SOUTHEAST. THIS AREA WILL SEE THE MOST EFFICIENT AND HEAVIER RAINFALL TONIGHT. SECOND AREA OF SHOWERS/ISOLATED STORMS IS ALONG THE ADVANCING FRONT MOVING INTO VALLEY COUNTY. EXPECTING THESE SHOWERS AND ISOLATED STORMS TO BE MOST NUMEROUS ACROSS THE NORTH THE NEXT FEW HOURS BUT GRADUALLY LESSEN IN COVERAGE AS THEY APPROACH THE I-80 CORRIDOR PER HRRR MODEL TRENDS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 324 PM CDT SUN APR 20 2014 ...SPOTTY SHWRS WITH POSSIBLE THUNDER DIMINISH WITH SUNSET THEN A BURST OF N WINDS TOMORROW MORNING WITH TEMPS REMAINING MILD... ALOFT: SPLIT FLOW CONTINUED OVER THE CONUS...WITH FASTER MORE PROGRESSIVE FLOW ALONG THE US-CANADIAN BORDER. THE SLOWER/WEAKER SRN STREAM WAS OVER THE SRN USA. A NRN STREAM SHORTWAVE TROF WAS OVER SASKATCHEWAN. THIS TROF WILL CONTINUE E INTO ONTARIO THRU TOMORROW. MEANWHILE...A COMPACT LOW WAS OVER THE SRN PLAINS. IT TOO WILL MOVE E ROUGHLY IN PHASE WITH THE NRN TROF. THE FLOW WILL CONSOLIDATE TOMORROW AND BECOME NW AS A RIDGE ADVANCES THRU THE WRN USA...AHEAD OF A TROF THAT WILL MOVE ONTO THE W COAST MON NIGHT. SURFACE: THE REMNANTS OF A COOL FRONT EXTENDED SW-NE FROM THE SANDHILLS TO NEAR MCCOOK. A PACIFIC ORIGIN COOL FRONT WAS PROGRESSING THRU THE NRN ROCKIES THIS AFTERNOON /ASSOCIATED WITH THE SASK TROF/ AND WE JUST EMERGING INTO THE WRN DAKOTAS. THIS FRONT WILL CROSS THE FCST AREA TONIGHT...BETWEEN MIDNIGHT AND SUNRISE. NRN PLAINS HIGH PRES WILL BUILD IN TOMORROW. THE REST OF THIS AFTERNOON: PARTLY-MOSTLY CLOUDY WITH SCATTERED SHWRS AND TSTMS. THIS ACTIVITY WILL NOT LAST LONG AT ANY ONE LOCATION...BUT COVERAGE WILL CONTINUE TO INCREASE THRU ROUGHLY 6 PM. MLCAPE WILL ONLY PEAK AT 500-750 J/KG. DEEP LAYER SHEAR WILL BE LESS THAN 15 KTS. SO SHWRS/TSTMS WILL BE PULSE-TYPE. THE ONLY REAL ORGANIZATION WILL BE SMALL CLUSTERS WHERE SHWRS/TSTMS IN CLOSE PROXIMITY GENERATE AND CONTRIBUTE TO A COMMON COLD POOL. INSTABILITY AND SHEAR ARE TOO WEAK FOR STRONG STORMS. SO THAT POTENTIAL THREAT WAS WITHDRAWN FROM THE HWO AT 1153 AM. QPF: UNFORTUNATELY...THE SHWRS/TSTMS WONT LAST LONG ENOUGH TO BE OF MUCH BENEFIT. TONIGHT: THE SCT SHWRS/TSTMS ARE DIURNALLY DRIVEN. SO EXPECT MOST OF THE ACTIVITY TO DIMINISH OR END 7PM-9PM. WITH THE NEXT COOL FRONT MOVING IN LATE...CANT COMPLETELY RULE OUT SOME ISOLATED RENEWED SHWR ACTIVITY /POSSIBLY THUNDER?/ S AND E OF THE TRI- CITIES. CLOUD DEBRIS FROM DISSIPATED SHWRS/TSTMS WILL EVENTUALLY BE SCOURED FROM NW-SE...MAINLY N AND W OF THE TRI-CITIES. USED BIAS CORRECTED CONSENSUS OF ALL GUIDANCE FOR LOW TEMPS. TOMORROW: THE DAY WILL START WITH LEFTOVER CLOUDS FROM THE TRI- CITIES S AND E. THESE CLOUDS WILL CONTINUE DEPARTING TO THE SE. COULD STILL SEE A COUPLE SHWRS OVER THE FAR SE FRINGE OF THE FCST AREA /E OF A LINE FROM YORK-NELSON-BELOIT/. WIND: THE PRES GRADIENT WILL BE TIGHT BEHIND THE FRONT...WITH A DECREASING 6 HR PRES RISE MAXIMUM. COMBINED WITH AN UNSTABLE BURST OF COLD AIR ADVECTION...EXPECT ABOUT A 6-HR PERIOD OF WINDY CONDITIONS FORENOON. WINDS WILL THEN DIMINISH IN THE AFTERNOON. THE CONSENSUS OF ALL GUIDANCE /MOS AND RAW MODEL 2M TEMPS/ APPEARED TO HAVE A GOOD HANDLE ON DEWPOINTS. KNOCKED 1-2F OFF AFTER EXAMINING FCST SOUNDINGS. BUT THIS WILL STILL KEEP MINIMUM RH LEVELS JUST ABOVE 20%. THERE SHOULD ONLY BE ABOUT 3 HRS OF NEAR CRITICAL FIRE DANGER...AS WINDS WILL BE SUBSIDING AS RH LEVELS BOTTOM OUT. THERE IS A FAIR AMOUNT OF SPREAD IN HIGH TEMP GUIDANCE. USED THE WEIGHTED CONSENSUS OF THE RECENTLY BEST-PERFORMING GUIDANCE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 324 PM CDT SUN APR 20 2014 WE BEGIN MONDAY NIGHT WITH BROAD RIDGING BUILDING IN ALOFT AND A SPLIT FLOW REGIME. AT THE SURFACE...A RIDGE WILL APPROACH AS WELL. THIS ENSURES A DRY FORECAST FOR MONDAY NIGHT INTO TUESDAY. ONE THING OF NOTE FOR TUESDAY IS A SURFACE TROUGH STRENGTHENING IN THE LEE SIDE OF THE ROCKY MOUNTAINS. MODELS VARY WITH THE PROGRESSION OF THE SURFACE RIDGE IS FOR TUESDAY. THIS WILL SIGNIFICANTLY INFLUENCE HOW WINDY WE WILL BE. THE ECMWF SOLUTION PLACES THE RIDGE OVER THE MISSISSIPPI VALLEY BY 00Z WEDNESDAY AND OTHER MODELS...INCLUDING THE GFS...HAVE COME IN LINE WITH THIS SOLUTION. THERE WILL BE A CONSIDERABLE SOUTH BREEZE AS A RESULT. THIS WILL INCREASE THE DEWPOINTS AT THE SURFACE AND PRIME US FOR INCREASED INSTABILITY FOR WEDNESDAY. LOW TEMPERATURES SHOULD BE CONSIDERABLY ABOVE NORMAL DUE TO THE WARM AIR ADVECTION TUESDAY NIGHT...AND GOING TOWARD THE CONSRAW SOLUTION FOR LOWS BECAUSE OF THIS. THERE IS INCREASING AGREEMENT AMONG NUMERICAL MODEL SOLUTIONS HEADING INTO WEDNESDAY. WE WILL BE SQUARELY IN THE RELATIVELY NARROW WARM SECTOR. BY AFTERNOON A DRY LINE WILL PROBABLY SCRAPE THE SOUTHERN PART OF THE CWA. WITH INCREASING MOISTURE AND PLENTY OF BULK SHEAR...THERE IS A GOOD SHOT AT SOME SEVERE WEATHER...ESPECIALLY IN OUR SOUTH...AND LESS SO IN OUR NORTHERN CWA. THE THREAT OF SEVERE WEATHER COULD CONTINUE WELL INTO THE EVENING...BUT MOST SOLUTIONS HAVE THE COLD FRONT MOVING THROUGH THE CWA BY MIDNIGHT OR SO. WE COULD HAVE SOME LINGERING SHOWERS IN THE OVERNIGHT INTO THURSDAY. THE NEXT FOCUS OF PRECIPITATION CHANCES ARRIVE FOR NEXT WEEKEND AS A NEGATIVELY TILTED WAVE MOVES INTO THE PLAINS. ALTHOUGH THERE ARE MODEL DIFFERENCES IN STRENGTH AND TIMING...THERE IS A GENERAL INDICATION OF A CHANCE OF SHOWERS AND THUNDERSTORMS AT SOME POINT OVER THE WEEKEND. IT IS STILL VERY MUCH UP IN THE AIR ON WHETHER WE COULD GET SEVERE WEATHER OUT OF THIS. NOT ENOUGH SEVERE PARAMETERS HAVE COME TOGETHER FOR ME TO MENTION THE POSSIBILITY OF STRONG OR SEVERE THUNDERSTORMS IN THE HWO. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1217 AM CDT MON APR 21 2014 VFR CONDITIONS ARE FORECAST FOR THE GRAND ISLAND AIRPORT BUT THERE AREA A WEATHER CHANGES. THE MAIN CHANGES WILL OCCUR WITH AN ADVANCING FRONTAL BOUNDARY SLATED TO PASS BY AROUND JUST PRIOR TO SUNRISE. AHEAD OF AND ALONG THE FRONT...SOME ISOLATED SHOWERS MAY BE IN THE AREA BUT NOT CONFIDENT ENOUGH TO SAY FOR SURE THE AIRPORT WILL ACTUALLY MEASURE ANY RAINFALL. HAVE INCLUDING THE SHOWERS IN THE VICINITY. ONCE THE FRONT GOES THROUGH...NORTH WINDS WILL PICK UP DRAMATICALLY AND GUST OVER 25KTS BY LATE MORNING AND DURING THE AFTERNOON. MID LEVEL CEILINGS WILL GIVE WAY TO SOME SCATTERED HIGH CLOUDS BY LATE MORNING. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...NOAA/NWS/MORITZ SHORT TERM...HALBLAUB LONG TERM...HEINLEIN AVIATION...NOAA/NWS/MORITZ
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1035 PM EDT TUE APR 22 2014 .SYNOPSIS... LOW PRESSURE WILL AFFECT THE NORTH COUNTRY TONIGHT RIGHT INTO WEDNESDAY NIGHT...WITH HIGH PRESSURE BUILDING OVER THE AREA FOR THURSDAY AND REMAINING RIGHT INTO FRIDAY MORNING. A LOW PRESSURE SYSTEM APPROACHES DURING THE DAY FRIDAY AND AFFECTS THE REGION RIGHT INTO THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 1020 PM EDT TUESDAY...LOW PRESSURE TRACKING ACROSS NORTHEAST VERMONT LATE THIS EVENING. INITIAL COLD FRONT ASSOCIATED WITH THE LOW...WHICH IS MORE OF A WIND SHIFT THAN A CHANGE IN AIRMASS...HAS JUST ABOUT EXITED VERMONT. SECONDARY FRONT...BEHIND WHICH LIES THE COLDER AIR...IS STILL BACK IN THE OTTAWA VALLEY. THIS SECOND BOUNDARY COUPLED WITH RATHER STRONG UPPER AIR DISTURBANCE MOVING EAST FROM THE GREAT LAKES...WILL RESULT IN CONTINUED CHANCE OF SHOWERS OVERNIGHT. AS FLOW TURNS MORE NORTHERLY BEHIND DEPARTING LOW...PRECIPITATION WILL BECOME MORE OROGRAPHIC IN NATURE...WITH FOCUS OVER HIGHER TERRAIN. AS AIRMASS COOLS...LOOK FOR A CHANGEOVER TO SNOW SHOWERS OVER THE MOUNTAINS. GOING FORECAST HAS IT ALL COVERED FAIRLY WELL. ONLY CHANGE WAS TO MAKE A FEW MINOR ADJUSTMENTS TO TEMPS BASED ON LATEST OBS AND TRENDS. THE RESULT WAS TO RAISE MINS A COUPLE OF DEGREES MOST AREAS. EXPECT LOWS IN THE UPPER 30S TO MID 40S. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 407 PM EDT TUESDAY...GOING INTO WEDNESDAY...SFC/UPPER LOW HAVE SHIFTED EAST OF THE REGION...SETTING THE AREA UP FOR NORTHERLY FLOW FOR THE NEXT SEVERAL PERIODS. FOCUS OF PRECIP WILL BE OVER HIR TRRN DUE TO UPSLOPE/OROGRAPHIC CONDITIONS...WITH A SLOW TAPER OF AREAL COVERAGE FROM WEST TO EAST WITH APPROACH OF SFC HIGH PRESSURE FROM THE CENTRAL PORTION OF THE COUNTRY. TEMPS WARM ENOUGH TO KEEP VALLEY LOCALES ALL -RW DURING THE DAY WEDNESDAY WITH -RW/-SW MIX FOR HIR TRRN. AREAS SHOULD SEE A COUPLE TENTHS OVERALL FOR QPF...WITH UP TO AN INCH OF -SW OVER HIR TRRN. POPS DUE TAPER SHARPLY GOING INTO WEDNESDAY NIGHT W/ MAIN FOCUS BEING NE VT TOWARDS THURSDAY MORNING. LINGERING LIGHT PRECIP IN NE VT FOR THURSDAY MORNING GIVING WAY TO HIGH PRESSURE FOR THURSDAY AND THURSDAY NIGHT. DECENT 24-HR STRETCH OF WX DURING THIS TIME ONCE -RW/-SW CLRS THE NE KINGDOM. OVERALL FOR TEMPS 40S MAINLY FOR WEDNESDAY HIGHS AND LIFTING INTO THE 50S FOR THURSDAY WITH AREA SEEING FULL SUNSHINE. OVERNGT LOWS WILL RANGE FROM THE 30S IN VALLEY LOCALES DOWN TO THE TEENS/20S IN HIR TRRN. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 400 PM EDT TUESDAY...LONG TERM STARTS DRY WITH ABOVE NORMAL TEMPS ON FRIDAY...BUT PLENTY OF UNCERTAINTY DEVELOPS OVER THE WEEKEND INTO EARLY NEXT WEEK WITH REGARDS TO MAGNITUDE OF TROF AND ASSOCIATED CAA. FOR FRIDAY...MID/UPPER RIDGE AND SFC HIGH PRES OVERHEAD WL RESULT IN MAINLY CLR SKIES WITH TEMPS IN THE 50S MTNS TO 60S VALLEYS. HAVE NOTED THE 12Z ECWMF IS MUCH WARMER WITH PROGGED 85H TEMPS BTWN 5-7C...WHICH COULD SUPPORT A FEW L70S. FOR SAT INTO SUNDAY...POTENT 5H VORT RACES ACRS THE GREAT LAKES INTO THE NE CONUS...WITH SECONDARY ENERGY DROPPING ON BACKSIDE HELPING TO DEVELOP A CLOSED 5H/7H CIRCULATION. THE TIMING OF THIS ENERGY INTERACTING WITH MAIN TROF WL HAVE A HUGE IMPACT ON OUR TEMPS/WEATHER OVER THE WEEKEND. CRNT GFS/ECMWF HAVE FLIP FLOPPED AGAIN ON THE OVERALL PATTERN...WITH GFS SUPPORTING A COOLER/WETTER SOLUTION WITH SOME WHITE IN THE MTNS...WHILE THE LATEST 12Z ECMWF IS MUCH LESS AMPLIFIED AND WARMER/DRIER. GIVEN THE UNCERTAINTY ON DEPTH OF TROF AND AMOUNT OF LLVL CAA BEHIND SFC BOUNDARY...WL MENTION TEMPS NEAR NORMAL ON SATURDAY WITH SHOWERS LIKELY AND BLW NORMAL ON SUNDAY WITH CHC SHOWERS MAINLY OVER THE MTNS. PROGGED 85H TEMPS RANGE BTWN 0-2C ON SAT...RESULTING IN HIGHS 40S MTNS TO 50S VALLEYS WITH LOWS IN THE 30S MTNS TO 40S VALLEYS ON SAT NIGHT. MUCH COOLER AIR ARRIVES SUNDAY WITH PROGGED 85H TEMPS BTWN -5C AND -7C AND 1000 TO 500MB THICKNESS VALUES BTWN 530 AND 534...SUPPORTING HIGHS MAINLY IN THE 30S MTNS TO 40S TO NEAR 50F VALLEYS. THESE PROFILES SUPPORT THE POTENTIAL FOR MTNS SNOW SHOWERS AT NIGHT...ESPECIALLY SAT NIGHT/SUNDAY NIGHT WITH MAINLY RAIN IN THE VALLEYS...DUE TO WARM BL TEMPS. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... THROUGH 00Z THURSDAY...SFC LOW NORTH OF LAKE CHAMPLAIN WITH FRONTAL OCCLUSION EXTENDING BACK ACROSS NEW YORK AND ONTARIO RESULTING IN WIDESPREAD MVFR TO IFR CEILINGS ACROSS NORTHERN NEW YORK THIS EVENING. AHEAD OF A SFC COLD FRONT EXTENDING DOWN THE CHAMPLAIN VALLEY...4-6SM -RA NOTED APPROACHING MPV. SFC LOW AND ASSOCIATED FRONTS WILL MOVE EASTWARD WITH VFR CEILINGS GRADUALLY GOING DOWN TO MVFR/IFR CEILINGS WITH PERIODS MVFR VISIBILITY IN RAIN...DRIZZLE...AND/OR MIST. THIS LINE OF THINKING IS SUPPORTED BY BOTH UPSTREAM OBSERVATIONS AND 21Z RAP BUFKIT SOUNDINGS. EXPECT MVFR TO IFR STRATUS/STRATOCUMULUS TO LINGER INTO THE MORNING HOURS. WINDS TO BECOME NORTHWEST 8-10 KTS WITH PASSAGE OF SFC LOW. EXPECT A CONTINUATION AT LEAST MVFR STRATOCUMULUS TO LINGER THROUGH THE DAY WEDNESDAY AS UPPER SHORTWAVE TROUGH DIGS INTO THE NORTH COUNTRY AND MAINTAINS PLENTY OF LOW- LEVEL MOISTURE AROUND. EXPECT SOME OF THIS MOISTURE TO FALL AS UPSLOPE RAIN/SNOW SHOWERS WITH POSSIBLE MVFR TO IFR VISIBILITY AT SLK AND MPV WITH VFR VISIBILITIES ELSEWHERE. NORTHWEST WINDS REMAIN AT OR AROUND 10 KTS. SOME QUESTION AS TO HOW MUCH MIXING CAN TAKE PLACE WEDNESDAY BUT ANY BREAKS IN OVC/BETTER MIXING COULD PRODUCE OCCASIONAL GUSTS TO 20 KTS. OUTLOOK 00Z THURSDAY THROUGH SATURDAY...COOLER AND UNSETTLED WX CONDITIONS CONTINUE INTO WEDS NIGHT WITH RAIN/SNOW SHOWERS LIKELY...AND SOME PERIODS OF MVFR/IFR CONDITIONS POSSIBLE AT KSLK/KMPV IN THE HEAVIER SNOW SHOWER ACTIVITY...ESPECIALLY AT NIGHT. SFC HIGH PRES AND VFR CONDITIONS RETURN FOR THURS INTO FRIDAY. CLOUDS INCREASE LATE FRIDAY WITH RAIN ARRIVING FRIDAY NIGHT INTO SATURDAY. MAINLY VFR CONDITIONS INITIALLY ON FRIDAY NIGHT...BUT MVFR WITH OCCASIONAL IFR POSSIBLE ON SATURDAY IN THE HEAVIER AREAS OF PRECIP. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JN NEAR TERM...RJS SHORT TERM...JN LONG TERM...TABER AVIATION...TABER/LOCONTO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
729 PM EDT TUE APR 22 2014 .SYNOPSIS... LOW PRESSURE WILL AFFECT THE NORTH COUNTRY TONIGHT RIGHT INTO WEDNESDAY NIGHT...WITH HIGH PRESSURE BUILDING OVER THE AREA FOR THURSDAY AND REMAINING RIGHT INTO FRIDAY MORNING. A LOW PRESSURE SYSTEM APPROACHES DURING THE DAY FRIDAY AND AFFECTS THE REGION RIGHT INTO THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 714 PM EDT TUESDAY...LOW PRESSURE TRACKING ACROSS NORTHERN VERMONT THIS EVENING ACCOMPANIED BY SOME SHOWERS. INITIAL COLD FRONT ASSOCIATED WITH THE LOW...MORE OF A WIND SHIFT THAN A CHANGE IN AIRMASS...EXTENDS SOUTH FROM THE LOW ACROSS VERMONT...WHILE SECONDARY FRONT BEHIND WHICH LIES THE COLDER AIR IS STILL BACK IN THE OTTAWA VALLEY. LITTLE CHANGE TO OVERALL FORECAST...WITH NUMEROUS SHOWERS THIS EVENING CONTINUING INTO THE OVERNIGHT AS RATHER STRONG UPPER AIR DISTURBANCE MOVES ACROSS THE REGION. DID ADD THE MENTION OF THUNDER FOR SOUTHERN SAINT LAWRENCE VALLEY FOR EARLY THIS EVENING BASED ON SOME ONGOING ACTIVITY IN THIS AREA...WHICH SHOULD DIMINISH BEFORE IT MAKES IT MUCH FURTHER EAST. MINOR ADJUSTMENTS TO HOURLY TEMPS THIS EVENING BASED ON LATEST OBSERVATIONS...BUT NO CHANGE TO OVERNIGHT MINS. PREVIOUS DISCUSSION... CLDY SKIES AND -RW ACROSS MUCH OF THE CWA THIS AFTNOON AS COLD FRONT MVS THRU THE AREA. SFC LOW ASSOCIATED WITH THE FRONT PASSING EAST ALONG THE CANADIAN BORDER. MDL TRACK WILL CONTINUE HAVING THIS SYSTEM MVG EAST OF REGION THRU THE OVERNGT HRS. WITH THIS TRACK...CWA WILL SEE TRANSITION FROM SOUTHERLY TO NORTHERLY FLOW...ALLOWING FOR CAA TO WORK INTO THE AREA AS THE EVENING/OVERNGT HRS PROGRESS. WITH THE SHIFT IN WIND FLOW...PRECIP WILL BEGIN TO BECM MORE OROGRAPHIC IN NATURE W/ FOCUS OVER HIR TRRN. COLDER AIR WILL CHANGEOVER PRECIP TO LIGHT -SW OVER HIR TRRN WITH LIGHT ACCUM TOWARDS WED MORNING. OVERNGT TEMPS WILL RANGE IN THE L40S IN VALLEY LOCALES DOWN TO THE 30S IN HIR TRRN. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 407 PM EDT TUESDAY...GOING INTO WEDNESDAY...SFC/UPPER LOW HAVE SHIFTED EAST OF THE REGION...SETTING THE AREA UP FOR NORTHERLY FLOW FOR THE NEXT SEVERAL PERIODS. FOCUS OF PRECIP WILL BE OVER HIR TRRN DUE TO UPSLOPE/OROGRAPHIC CONDITIONS...WITH A SLOW TAPER OF AREAL COVERAGE FROM WEST TO EAST WITH APPROACH OF SFC HIGH PRESSURE FROM THE CENTRAL PORTION OF THE COUNTRY. TEMPS WARM ENOUGH TO KEEP VALLEY LOCALES ALL -RW DURING THE DAY WEDNESDAY WITH -RW/-SW MIX FOR HIR TRRN. AREAS SHOULD SEE A COUPLE TENTHS OVERALL FOR QPF...WITH UP TO AN INCH OF -SW OVER HIR TRRN. POPS DUE TAPER SHARPLY GOING INTO WEDNESDAY NIGHT W/ MAIN FOCUS BEING NE VT TOWARDS THURSDAY MORNING. LINGERING LIGHT PRECIP IN NE VT FOR THURSDAY MORNING GIVING WAY TO HIGH PRESSURE FOR THURSDAY AND THURSDAY NIGHT. DECENT 24-HR STRETCH OF WX DURING THIS TIME ONCE -RW/-SW CLRS THE NE KINGDOM. OVERALL FOR TEMPS 40S MAINLY FOR WEDNESDAY HIGHS AND LIFTING INTO THE 50S FOR THURSDAY WITH AREA SEEING FULL SUNSHINE. OVERNGT LOWS WILL RANGE FROM THE 30S IN VALLEY LOCALES DOWN TO THE TEENS/20S IN HIR TRRN. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 400 PM EDT TUESDAY...LONG TERM STARTS DRY WITH ABOVE NORMAL TEMPS ON FRIDAY...BUT PLENTY OF UNCERTAINTY DEVELOPS OVER THE WEEKEND INTO EARLY NEXT WEEK WITH REGARDS TO MAGNITUDE OF TROF AND ASSOCIATED CAA. FOR FRIDAY...MID/UPPER RIDGE AND SFC HIGH PRES OVERHEAD WL RESULT IN MAINLY CLR SKIES WITH TEMPS IN THE 50S MTNS TO 60S VALLEYS. HAVE NOTED THE 12Z ECWMF IS MUCH WARMER WITH PROGGED 85H TEMPS BTWN 5-7C...WHICH COULD SUPPORT A FEW L70S. FOR SAT INTO SUNDAY...POTENT 5H VORT RACES ACRS THE GREAT LAKES INTO THE NE CONUS...WITH SECONDARY ENERGY DROPPING ON BACKSIDE HELPING TO DEVELOP A CLOSED 5H/7H CIRCULATION. THE TIMING OF THIS ENERGY INTERACTING WITH MAIN TROF WL HAVE A HUGE IMPACT ON OUR TEMPS/WEATHER OVER THE WEEKEND. CRNT GFS/ECMWF HAVE FLIP FLOPPED AGAIN ON THE OVERALL PATTERN...WITH GFS SUPPORTING A COOLER/WETTER SOLUTION WITH SOME WHITE IN THE MTNS...WHILE THE LATEST 12Z ECMWF IS MUCH LESS AMPLIFIED AND WARMER/DRIER. GIVEN THE UNCERTAINTY ON DEPTH OF TROF AND AMOUNT OF LLVL CAA BEHIND SFC BOUNDARY...WL MENTION TEMPS NEAR NORMAL ON SATURDAY WITH SHOWERS LIKELY AND BLW NORMAL ON SUNDAY WITH CHC SHOWERS MAINLY OVER THE MTNS. PROGGED 85H TEMPS RANGE BTWN 0-2C ON SAT...RESULTING IN HIGHS 40S MTNS TO 50S VALLEYS WITH LOWS IN THE 30S MTNS TO 40S VALLEYS ON SAT NIGHT. MUCH COOLER AIR ARRIVES SUNDAY WITH PROGGED 85H TEMPS BTWN -5C AND -7C AND 1000 TO 500MB THICKNESS VALUES BTWN 530 AND 534...SUPPORTING HIGHS MAINLY IN THE 30S MTNS TO 40S TO NEAR 50F VALLEYS. THESE PROFILES SUPPORT THE POTENTIAL FOR MTNS SNOW SHOWERS AT NIGHT...ESPECIALLY SAT NIGHT/SUNDAY NIGHT WITH MAINLY RAIN IN THE VALLEYS...DUE TO WARM BL TEMPS. && .AVIATION /23Z TUESDAY THROUGH SUNDAY/... THROUGH 00Z THURSDAY...SFC LOW NORTH OF LAKE CHAMPLAIN WITH FRONTAL OCCLUSION EXTENDING BACK ACROSS NEW YORK AND ONTARIO RESULTING IN WIDESPREAD MVFR TO IFR CEILINGS ACROSS NORTHERN NEW YORK THIS EVENING. AHEAD OF A SFC COLD FRONT EXTENDING DOWN THE CHAMPLAIN VALLEY...4-6SM -RA NOTED APPROACHING MPV. SFC LOW AND ASSOCIATED FRONTS WILL MOVE EASTWARD WITH VFR CEILINGS GRADUALLY GOING DOWN TO MVFR/IFR CEILINGS WITH PERIODS MVFR VISIBILITY IN RAIN...DRIZZLE...AND/OR MIST. THIS LINE OF THINKING IS SUPPORTED BY BOTH UPSTREAM OBSERVATIONS AND 21Z RAP BUFKIT SOUNDINGS. EXPECT MVFR TO IFR STRATUS/STRATOCUMULUS TO LINGER INTO THE MORNING HOURS. WINDS TO BECOME NORTHWEST 8-10 KTS WITH PASSAGE OF SFC LOW. EXPECT A CONTINUATION AT LEAST MVFR STRATOCUMULUS TO LINGER THROUGH THE DAY WEDNESDAY AS UPPER SHORTWAVE TROUGH DIGS INTO THE NORTH COUNTRY AND MAINTAINS PLENTY OF LOW- LEVEL MOISTURE AROUND. EXPECT SOME OF THIS MOISTURE TO FALL AS UPSLOPE RAIN/SNOW SHOWERS WITH POSSIBLE MVFR TO IFR VISIBILITY AT SLK AND MPV WITH VFR VISIBILITIES ELSEWHERE. NORTHWEST WINDS REMAIN AT OR AROUND 10 KTS. SOME QUESTION AS TO HOW MUCH MIXING CAN TAKE PLACE WEDNESDAY BUT ANY BREAKS IN OVC/BETTER MIXING COULD PRODUCE OCCASIONAL GUSTS TO 20 KTS. OUTLOOK 00Z THURSDAY THROUGH SATURDAY...COOLER AND UNSETTLED WX CONDITIONS CONTINUE INTO WEDS NIGHT WITH RAIN/SNOW SHOWERS LIKELY...AND SOME PERIODS OF MVFR/IFR CONDITIONS POSSIBLE AT KSLK/KMPV IN THE HEAVIER SNOW SHOWER ACTIVITY...ESPECIALLY AT NIGHT. SFC HIGH PRES AND VFR CONDITIONS RETURN FOR THURS INTO FRIDAY. CLOUDS INCREASE LATE FRIDAY WITH RAIN ARRIVING FRIDAY NIGHT INTO SATURDAY. MAINLY VFR CONDITIONS INITIALLY ON FRIDAY NIGHT...BUT MVFR WITH OCCASIONAL IFR POSSIBLE ON SATURDAY IN THE HEAVIER AREAS OF PRECIP. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JN NEAR TERM...RJS/JN SHORT TERM...JN LONG TERM...TABER AVIATION...TABER/LOCONTO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
712 PM EDT TUE APR 22 2014 .SYNOPSIS... LOW PRESSURE WILL AFFECT THE NORTH COUNTRY TONIGHT RIGHT INTO WEDNESDAY NIGHT...WITH HIGH PRESSURE BUILDING OVER THE AREA FOR THURSDAY AND REMAINING RIGHT INTO FRIDAY MORNING. A LOW PRESSURE SYSTEM APPROACHES DURING THE DAY FRIDAY AND AFFECTS THE REGION RIGHT INTO THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 407 PM EDT TUESDAY...CLDY SKIES AND -RW ACROSS MUCH OF THE CWA THIS AFTNOON AS COLD FRONT MVS THRU THE AREA. SFC LOW ASSOCIATED WITH THE FRONT PASSING EAST ALONG THE CANADIAN BORDER. MDL TRACK WILL CONTINUE HAVING THIS SYSTEM MVG EAST OF REGION THRU THE OVERNGT HRS. WITH THIS TRACK...CWA WILL SEE TRANSITION FROM SOUTHERLY TO NORTHERLY FLOW...ALLOWING FOR CAA TO WORK INTO THE AREA AS THE EVENING/OVERNGT HRS PROGRESS. WITH THE SHIFT IN WIND FLOW...PRECIP WILL BEGIN TO BECM MORE OROGRAPHIC IN NATURE W/ FOCUS OVER HIR TRRN. COLDER AIR WILL CHANGEOVER PRECIP TO LIGHT -SW OVER HIR TRRN WITH LIGHT ACCUM TOWARDS WED MORNING. OVERNGT TEMPS WILL RANGE IN THE L40S IN VALLEY LOCALES DOWN TO THE 30S IN HIR TRRN. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 407 PM EDT TUESDAY...GOING INTO WEDNESDAY...SFC/UPPER LOW HAVE SHIFTED EAST OF THE REGION...SETTING THE AREA UP FOR NORTHERLY FLOW FOR THE NEXT SEVERAL PERIODS. FOCUS OF PRECIP WILL BE OVER HIR TRRN DUE TO UPSLOPE/OROGRAPHIC CONDITIONS...WITH A SLOW TAPER OF AREAL COVERAGE FROM WEST TO EAST WITH APPROACH OF SFC HIGH PRESSURE FROM THE CENTRAL PORTION OF THE COUNTRY. TEMPS WARM ENOUGH TO KEEP VALLEY LOCALES ALL -RW DURING THE DAY WEDNESDAY WITH -RW/-SW MIX FOR HIR TRRN. AREAS SHOULD SEE A COUPLE TENTHS OVERALL FOR QPF...WITH UP TO AN INCH OF -SW OVER HIR TRRN. POPS DUE TAPER SHARPLY GOING INTO WEDNESDAY NIGHT W/ MAIN FOCUS BEING NE VT TOWARDS THURSDAY MORNING. LINGERING LIGHT PRECIP IN NE VT FOR THURSDAY MORNING GIVING WAY TO HIGH PRESSURE FOR THURSDAY AND THURSDAY NIGHT. DECENT 24-HR STRETCH OF WX DURING THIS TIME ONCE -RW/-SW CLRS THE NE KINGDOM. OVERALL FOR TEMPS 40S MAINLY FOR WEDNESDAY HIGHS AND LIFTING INTO THE 50S FOR THURSDAY WITH AREA SEEING FULL SUNSHINE. OVERNGT LOWS WILL RANGE FROM THE 30S IN VALLEY LOCALES DOWN TO THE TEENS/20S IN HIR TRRN. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 400 PM EDT TUESDAY...LONG TERM STARTS DRY WITH ABOVE NORMAL TEMPS ON FRIDAY...BUT PLENTY OF UNCERTAINTY DEVELOPS OVER THE WEEKEND INTO EARLY NEXT WEEK WITH REGARDS TO MAGNITUDE OF TROF AND ASSOCIATED CAA. FOR FRIDAY...MID/UPPER RIDGE AND SFC HIGH PRES OVERHEAD WL RESULT IN MAINLY CLR SKIES WITH TEMPS IN THE 50S MTNS TO 60S VALLEYS. HAVE NOTED THE 12Z ECWMF IS MUCH WARMER WITH PROGGED 85H TEMPS BTWN 5-7C...WHICH COULD SUPPORT A FEW L70S. FOR SAT INTO SUNDAY...POTENT 5H VORT RACES ACRS THE GREAT LAKES INTO THE NE CONUS...WITH SECONDARY ENERGY DROPPING ON BACKSIDE HELPING TO DEVELOP A CLOSED 5H/7H CIRCULATION. THE TIMING OF THIS ENERGY INTERACTING WITH MAIN TROF WL HAVE A HUGE IMPACT ON OUR TEMPS/WEATHER OVER THE WEEKEND. CRNT GFS/ECMWF HAVE FLIP FLOPPED AGAIN ON THE OVERALL PATTERN...WITH GFS SUPPORTING A COOLER/WETTER SOLUTION WITH SOME WHITE IN THE MTNS...WHILE THE LATEST 12Z ECMWF IS MUCH LESS AMPLIFIED AND WARMER/DRIER. GIVEN THE UNCERTAINTY ON DEPTH OF TROF AND AMOUNT OF LLVL CAA BEHIND SFC BOUNDARY...WL MENTION TEMPS NEAR NORMAL ON SATURDAY WITH SHOWERS LIKELY AND BLW NORMAL ON SUNDAY WITH CHC SHOWERS MAINLY OVER THE MTNS. PROGGED 85H TEMPS RANGE BTWN 0-2C ON SAT...RESULTING IN HIGHS 40S MTNS TO 50S VALLEYS WITH LOWS IN THE 30S MTNS TO 40S VALLEYS ON SAT NIGHT. MUCH COOLER AIR ARRIVES SUNDAY WITH PROGGED 85H TEMPS BTWN -5C AND -7C AND 1000 TO 500MB THICKNESS VALUES BTWN 530 AND 534...SUPPORTING HIGHS MAINLY IN THE 30S MTNS TO 40S TO NEAR 50F VALLEYS. THESE PROFILES SUPPORT THE POTENTIAL FOR MTNS SNOW SHOWERS AT NIGHT...ESPECIALLY SAT NIGHT/SUNDAY NIGHT WITH MAINLY RAIN IN THE VALLEYS...DUE TO WARM BL TEMPS. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... THROUGH 00Z THURSDAY...SFC LOW NORTH OF LAKE CHAMPLAIN WITH FRONTAL OCCLUSION EXTENDING BACK ACROSS NEW YORK AND ONTARIO RESULTING IN WIDESPREAD MVFR TO IFR CEILINGS ACROSS NORTHERN NEW YORK THIS EVENING. AHEAD OF A SFC COLD FRONT EXTENDING DOWN THE CHAMPLAIN VALLEY...4-6SM -RA NOTED APPROACHING MPV. SFC LOW AND ASSOCIATED FRONTS WILL MOVE EASTWARD WITH VFR CEILINGS GRADUALLY GOING DOWN TO MVFR/IFR CEILINGS WITH PERIODS MVFR VISIBILITY IN RAIN...DRIZZLE...AND/OR MIST. THIS LINE OF THINKING IS SUPPORTED BY BOTH UPSTREAM OBSERVATIONS AND 21Z RAP BUFKIT SOUNDINGS. EXPECT MVFR TO IFR STRATUS/STRATOCUMULUS TO LINGER INTO THE MORNING HOURS. WINDS TO BECOME NORTHWEST 8-10 KTS WITH PASSAGE OF SFC LOW. EXPECT A CONTINUATION AT LEAST MVFR STRATOCUMULUS TO LINGER THROUGH THE DAY WEDNESDAY AS UPPER SHORTWAVE TROUGH DIGS INTO THE NORTH COUNTRY AND MAINTAINS PLENTY OF LOW- LEVEL MOISTURE AROUND. EXPECT SOME OF THIS MOISTURE TO FALL AS UPSLOPE RAIN/SNOW SHOWERS WITH POSSIBLE MVFR TO IFR VISIBILITY AT SLK AND MPV WITH VFR VISIBILITIES ELSEWHERE. NORTHWEST WINDS REMAIN AT OR AROUND 10 KTS. SOME QUESTION AS TO HOW MUCH MIXING CAN TAKE PLACE WEDNESDAY BUT ANY BREAKS IN OVC/BETTER MIXING COULD PRODUCE OCCASIONAL GUSTS TO 20 KTS. OUTLOOK 00Z THURSDAY THROUGH SATURDAY...COOLER AND UNSETTLED WX CONDITIONS CONTINUE INTO WEDS NIGHT WITH RAIN/SNOW SHOWERS LIKELY...AND SOME PERIODS OF MVFR/IFR CONDITIONS POSSIBLE AT KSLK/KMPV IN THE HEAVIER SNOW SHOWER ACTIVITY...ESPECIALLY AT NIGHT. SFC HIGH PRES AND VFR CONDITIONS RETURN FOR THURS INTO FRIDAY. CLOUDS INCREASE LATE FRIDAY WITH RAIN ARRIVING FRIDAY NIGHT INTO SATURDAY. MAINLY VFR CONDITIONS INITIALLY ON FRIDAY NIGHT...BUT MVFR WITH OCCASIONAL IFR POSSIBLE ON SATURDAY IN THE HEAVIER AREAS OF PRECIP. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JN NEAR TERM...JN SHORT TERM...JN LONG TERM...TABER AVIATION...TABER/LOCONTO
AREA FORECAST DISCUSSION
NWS BISMARCK ND
944 PM CDT TUE APR 22 2014 .UPDATE... ISSUED AT 934 PM CDT TUE APR 22 2014 LATE EVENING UPDATE MAINLY FOR POP/WEATHER TRENDS OVERNIGHT. BASED IN PART OF THE 23/01Z RAP AND THE 23/00Z NAM...HAVE SLOWED THE NORTHWARD PROGRESSION OF THE SHOWERS SLIGHTLY OVERNIGHT AND BOOSTED POPS SOMEWHAT IN THE SOUTHWEST. ALSO FOLLOWED THE RAP SHOWALTER INDEX PROGS TO TRIM BACK THE ISOLATED THUNDER OVERNIGHT INTO THE FAR SOUTHWEST. SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE WEDNESDAY...ESPECIALLY ACROSS THE NORTHEAST HALF OF THE FORECAST AREA. UPDATE ISSUED AT 629 PM CDT TUE APR 22 2014 NO SIGNIFICANT CHANGES FOR EARLY EVENING UPDATE. SHOWERS EXPECTED TO DEVELOP BY LATE EVENING THEN SPREAD NORTH OVERNIGHT. AN ISOLATED RUMBLE OF THUNDER IS NOT OUT OF THE QUESTION FAR WEST OVERNIGHT. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 335 PM CDT TUE APR 22 2014 GUSTY SOUTHEASTERLY WINDS WILL CONTINUE ACROSS WESTERN AND CENTRAL NORTH DAKOTA LATER THIS AFTERNOON AND OVERNIGHT. THE MODELS HAVE BEEN PERFORMING POORLY WITH RESPECT TO AFTERNOON DEWPOINTS (TOO HIGH). AS A RESULT...MANUALLY ADJUSTED THE AFTERNOON DEWPOINTS DOWN BASED ON THE CURRENT OBS/TRENDS. THE COMBINATION OF HIGH WINDS AND LOW RELATIVE HUMIDITIES CONTINUE TO GENERATE A VERY HIGH FIRE DANGER OVER WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON. DEWPOINT RECOVERY SHOULD BEGIN IN EARNEST AFTER SUNSET AS LOW-LEVEL MOISTURE GETS DRAWN UP OVER THE STATE AHEAD OF AN APPROACHING LONGWAVE TROUGH. THE MEDIUM RANGE MODELS PROG THAT LIGHT RAIN SHOWERS WILL BECOME LIKELY AFTER MIDNIGHT AHEAD OF THE AFOREMENTIONED APPROACHING LONGWAVE TROUGH. THE MAIN BAND OF WARM AIR ADVECTION/CONVEYOR BELT PRECIPITATION IS EXPECTED TO DEVELOP FROM THE JAMES RIVER BASIN AND EXTEND NORTHWEST INTO MINOT AND NORTHWESTERN NORTH DAKOTA. FURTHERMORE...MARGINAL MID-LEVEL LAPSE RATES COMBINED WITH INCREASING UPPER LEVEL FORCING COULD GENERATE A SLIGHT CHANCE FOR THUNDERSTORMS WEST AFTER MIDNIGHT. HOWEVER...NO ORGANIZED SEVERE WEATHER IS EXPECTED. BY WEDNESDAY...THE MAIN PRECIPITATION BAND IS FORECAST TO LIFT NORTHEAST AS THE ATTENDANT SURFACE TROUGH AXIS LIFTS NORTHEAST ACROSS THE STATE. AGAIN...MARGINAL CONVECTIVE PARAMETERS WARRANT AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS MENTION OVER CENTRAL AND EASTERN NORTH DAKOTA...MAINLY ALONG THE BOUNDARY AS IT PUSHES ACROSS THE STATE. THIS IS CONSISTENT WITH THE SPC DAY 2 OUTLOOK. MARGINAL WIND ADVISORY CRITERIA MAY DEVELOP OVER SOUTHWESTERN NORTH DAKOTA WEDNESDAY AFTERNOON. WILL HOLD OFF ON ISSUING ANY WIND HEADLINES FOR THIS UPDATE AND WILL LET LATER SHIFTS DECIDE. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 335 PM CDT TUE APR 22 2014 TWO VIGOROUS SYSTEMS WILL INFLUENCE THE WEATHER ACROSS WESTERN AND CENTRAL NORTH DAKOTA IN THE LONG TERM PERIOD. SYSTEM 1... A WAVE MOVING ACROSS THE NORTHWEST U.S. AND SOUTHWEST CANADA IS EXPECTED TO DEVELOP A CLOSED UPPER LEVEL CIRCULATION OVER SOUTHERN BRITISH COLUMBIA/ALBERTA ON WEDNESDAY AND TRACK SLOWLY EAST ALONG THE INTERNATIONAL BORDER THROUGH FRIDAY. A SURFACE WARM FRONT IS FORECAST TO BE NEAR THE DEVILS LAKE AND JAMES RIVER BASIN BY WEDNESDAY EVENING...WITH SOUTHEAST WINDS AHEAD OF THE WARM FRONT AND WEST WINDS BEHIND IT. SCATTERED TO NUMEROUS SHOWERS DURING THE DAY WEDNESDAY SHOULD BE MAKING THEIR WAY ALONG AND AHEAD OF THE WARM FRONT...WITH A DRY SLOT BEHIND IT OVER SOUTHWESTERN NORTH DAKOTA. THUS EXPECTING EVENING SCATTERED SHOWERS NORTH THROUGH THE JAMES RIVER VALLEY...WITH MAINLY SLIGHT CHANCES OF SHOWERS AFTER MIDNIGHT. ON THURSDAY MORNING A SURFACE LOW ALONG THE NORTHERN BRANCH OF THE WARM FRONT IS FORECAST TO BE SITUATED OVER SOUTHERN SASKATCHEWAN. THIS LOW IS FORECAST TO MOVE SOUTHEAST ACROSS NORTH DAKOTA ON THURSDAY...WITH A BAROCLINIC ZONE/BOUNDARY SETTING UP NORTHWEST-TO-SOUTHEAST ACROSS THE STATE THURSDAY NIGHT. THIS SCENARIO WILL BRING A CHANCE OF SHOWERS - BETTER CHANCES NORTH - WITH THUNDERSTORMS POSSIBLE THURSDAY AFTERNOON. LATE THURSDAY NIGHT AND FRIDAY A COLD FRONT MOVES SOUTH ACROSS THE STATE...BRINGING A CHANCE OF RAIN OR SNOW SHOWERS - MAINLY NORTH IN THE TURTLE MOUNTAINS...BUT WITH LITTLE OR NO SNOW ACCUMULATIONS. SYSTEM 2... DURING THIS TIME THE NEXT STRONG SYSTEM IS TAKING SHAPE OVER THE WESTERN U.S. MODEL UNCERTAINTY INCREASES AS WE HEAD INTO THE WEEKEND BUT IT APPEARS THAT THE UPPER LEVEL FLOW IS TRENDING SLOWER WITH A BLOCKING PATTERN SETTING UP OVER THE CENTRAL PORTION OF THE COUNTRY. THIS BLOCK MAINLY KEEPS A COLD HIGH PRESSURE SYSTEM OVER HUDSON BAY WHILE A LARGE UPPER LEVEL LOW DEVELOPS ACROSS THE US ROCKIES AND CLOSES OFF SOMEWHERE IN THE WESTERN/CENTRAL/SOUTHERN PLAINS. WILL NEED TO KEEP AN EYE ON THE EVOLUTION OF THIS SYSTEM AS LATEST DETERMINISTIC RUNS ARE COLDER AND WETTER ACROSS WESTERN AND CENTRAL NORTH DAKOTA. UTILIZED A STRAIGHT MODEL BLEND FOR THE EXTENDED AND THIS IS DEPICTING PRECIPITATION ACROSS MAINLY THE SOUTHWEST ON SATURDAY...THEN SPREADING ACROSS MOST OF THE AREA SUNDAY THROUGH MONDAY. WITH COLDER TEMPERATURES EXPECTED BY THE WEEKEND PRECIPITATION CHANCES WERE MAINLY RAIN DURING THE AFTERNOON AND EARLY EVENING...WITH A MIX OF RAIN AND SNOW DURING THE OVERNIGHT AND EARLY MORNING HOURS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 629 PM CDT TUE APR 22 2014 BREEZY CONDITIONS WILL CONTINUE OVERNIGHT INTO WEDNESDAY WITH A SOUTHEAST WIND GUSTING OVER 20 KTS. SHOWERS EXPECTED TO DEVELOP BETWEEN 06Z AND 09Z AND CONTINUE PAST DAYBREAK...FOLLOWED BY A LATE MORNING LULL AND ADDITIONAL SHOWERS/ISOLD THUNDERSTORMS WEDNESDAY AFTERNOON. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE/AVIATION...RP KINNEY SHORT TERM...TM LONG TERM...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1252 PM CDT MON APR 21 2014 .UPDATE... ISSUED AT 1252 PM CDT MON APR 21 2014 A NARROW STRIP OF CLOUDS EXTENDED FROM CROSBY TO TIOGA...SOUTH THROUGH CENTER AND BISMARCK. THESE CLOUDS SHOULD ERODE WITHIN THE NEXT HOUR OR TWO AS SYNOPTIC SUBSIDENCE SPREADS OVER THE REGION. UPDATED THE FORECAST TO REMOVE MORNING WORDING AND INDICATED MOSTLY SUNNY SKIES OVER WESTERN AND CENTRAL NORTH DAKOTA. THE REMAINING FORECAST ELEMENTS ARE IN GOOD SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 1003 AM CDT MON APR 21 2014 UPDATED THE FORECAST TO INCREASE CLOUD COVER OVER THE SOUTHEASTERN CWA THIS MORNING BASED ON THE TRAJECTORY OF LOW STRATUS ROTATING SOUTHEAST ACROSS WESTERN AND CENTRAL NORTH DAKOTA. STRONG SYNOPTIC SUBSIDENCE OVERSPREADING THE REGION SHOULD ERODE THIS CLOUD DECK BY EARLY AFTERNOON. OTHERWISE...THE REMAINING FORECAST ELEMENTS ARE IN GOOD SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 625 AM CDT MON APR 21 2014 ONLY CHANGES TO FORECAST WERE TO POPULATE WITH LATEST HOURLY OBSERVATIONS. TEMPS WERE RUNNING A LITTLE COLDER THAN FORECAST IN A FEW LOCATIONS. OTHERWISE...LOW STRATUS CONTINUES TO SLOWLY PUSH SOUTHWARD WHICH IS HANDLED WELL IN FORECAST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 348 AM CDT MON APR 21 2014 NO MAJOR FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD. CURRENTLY...QUASI-ZONAL FLOW ACROSS THE NORTHERN PLAINS WITH A STRONG EMBEDDED S/WV TROUGH PUSHING EAST ALONG THE INTERNATIONAL BORDER...NOW CENTERED NEAR TO EAST OF LAKE WINNIPEG. WRAP AROUND MOISTURE IN THE FORM OF LOW LEVEL STRATUS SURGING SOUTH AND EAST ACROSS MY NORTHERN COUNTIES THE PAST COUPLE OF HOURS. AT THIS TIME DO NOT ANTICIPATE ANY PRECIPITATION ASSOCIATED WITH THE STRATUS. WILL CONTINUE TO MONITOR. LOW BKN-OVC CLOUDS WILL CONTINUE TO MOVE ACROSS NORTHWEST AND NORTH CENTRAL NORTH DAKOTA NOW THROUGH 10Z...EVENTUALLY DEPICTED BY BOTH THE RAP AND 00Z/06Z NAM TO PUSH AS FAR SOUTH AS BISMARCK AND JAMESTOWN 10-14Z. AFTERWARDS...STRATUS SHOULD DISSIPATE/BURN OFF BY THE EARLY AFTERNOON. THE MORNING CLOUDS COUPLED WITH CAA THE PAST SEVERAL HOURS WILL RESULT IN HIGH TEMPERATURES TODAY IN THE 50S ALONG TO NORTH AND EAST OF THE MISSOURI RIVER...60S SOUTH AND WEST OF THE MISSOURI. RETURN FLOW/WAA TONIGHT AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE AMPLIFIES ACROSS THE ROCKIES TODAY THEN PROPAGATES EAST INTO THE HIGH PLAINS TONIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 348 AM CDT MON APR 21 2014 ACTIVE PERIOD EXPECTED WITH STRONG STORM SYSTEM APPROACHING THE REGION TUESDAY NIGHT. LARGE SURFACE LOW INITIALLY CENTERED OVER CENTRAL MONTANA 00Z WEDNESDAY TRANSITIONS TO DUAL SURFACE LOWS OVER SOUTHEASTERN SASKATCHEWAN AND SOUTHEAST MONTANA BY 12Z WED AS SHORTWAVE/90KT H250 JET STREAK ROTATE AROUND PARENT UPPER LOW. BREEZY TO WINDY EAST/SOUTHEAST WINDS WILL OCCUR ALSO WITH TIGHT SURFACE GRADIENT AND 850MB WINDS TO 45KTS LATE TUESDAY AND TUESDAY NIGHT. SPC CONTINUES TO INCLUDE THE WESTERN HALF OF THE STATE IN GENERAL THUNDERSTORM AREA WITH MODELS INDICATING LOW CAPE NUDGING INTO THIS REGION ALONG WITH H7-H5 LAPSE RATES APPROACHING 8C/KM TUESDAY NIGHT AHEAD OF THE COLD FRONT. MODELS CONTINUE TO SHOW HIGHEST QPF ACROSS NORTH AND EAST AS DRY SLOT IS MORE OF A FACTOR ACROSS WESTERN AND SOUTHERN AREAS. WEDNESDAY NIGHT INTO THURSDAY THE CLOSED UPPER LOW AND ASSOCIATED SURFACE LOW MOVE ACROSS THE NORTHERN PLAINS. MODEL DIFFERENCES INCREASE WITH THIS FEATURE WITH THE GFS A LITTLE FASTER AND FARTHER SOUTH COMPARED TO ECMWF. BOTH MODELS...HOWEVER...BRING SUB 0C H850 AIR ACROSS THE STATE IN NORTHERLY FLOW BEHIND THE SYSTEM THURSDAY NIGHT WITH LIGHT PRECIP IN THE FORM OF RAIN CHANGING TO SNOW FROM NORTH TO SOUTH. SUBSTANTIAL MODEL DIFFERENCES BY NEXT WEEKEND WITH GFS SHOWING STRONGER RIDGE AND DRYER WEATHER OVER ND ON SATURDAY WHILE ECMWF HAS LESS AMPLIFIED PATTERN AND ANOTHER BATCH OF PRECIP MOVING IN UNDER SOUTHWEST FLOW ALOFT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1252 PM CDT MON APR 21 2014 MVFR CIGS OVER KBIS SHOULD BECOME VFR BY 19Z. OTHERWISE...VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE TAF PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TM SHORT TERM...NH LONG TERM...JNS AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1003 AM CDT MON APR 21 2014 .UPDATE... ISSUED AT 1003 AM CDT MON APR 21 2014 UPDATED THE FORECAST TO INCREASE CLOUD COVER OVER THE SOUTHEASTERN CWA THIS MORNING BASED ON THE TRAJECTORY OF LOW STRATUS ROTATING SOUTHEAST ACROSS WESTERN AND CENTRAL NORTH DAKOTA. STRONG SYNOPTIC SUBSIDENCE OVERSPREADING THE REGION SHOULD ERODE THIS CLOUD DECK BY EARLY AFTERNOON. OTHERWISE...THE REMAINING FORECAST ELEMENTS ARE IN GOOD SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 625 AM CDT MON APR 21 2014 ONLY CHANGES TO FORECAST WERE TO POPULATE WITH LATEST HOURLY OBSERVATIONS. TEMPS WERE RUNNING A LITTLE COLDER THAN FORECAST IN A FEW LOCATIONS. OTHERWISE...LOW STRATUS CONTINUES TO SLOWLY PUSH SOUTHWARD WHICH IS HANDLED WELL IN FORECAST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 348 AM CDT MON APR 21 2014 NO MAJOR FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD. CURRENTLY...QUASI-ZONAL FLOW ACROSS THE NORTHERN PLAINS WITH A STRONG EMBEDDED S/WV TROUGH PUSHING EAST ALONG THE INTERNATIONAL BORDER...NOW CENTERED NEAR TO EAST OF LAKE WINNIPEG. WRAP AROUND MOISTURE IN THE FORM OF LOW LEVEL STRATUS SURGING SOUTH AND EAST ACROSS MY NORTHERN COUNTIES THE PAST COUPLE OF HOURS. AT THIS TIME DO NOT ANTICIPATE ANY PRECIPITATION ASSOCIATED WITH THE STRATUS. WILL CONTINUE TO MONITOR. LOW BKN-OVC CLOUDS WILL CONTINUE TO MOVE ACROSS NORTHWEST AND NORTH CENTRAL NORTH DAKOTA NOW THROUGH 10Z...EVENTUALLY DEPICTED BY BOTH THE RAP AND 00Z/06Z NAM TO PUSH AS FAR SOUTH AS BISMARCK AND JAMESTOWN 10-14Z. AFTERWARDS...STRATUS SHOULD DISSIPATE/BURN OFF BY THE EARLY AFTERNOON. THE MORNING CLOUDS COUPLED WITH CAA THE PAST SEVERAL HOURS WILL RESULT IN HIGH TEMPERATURES TODAY IN THE 50S ALONG TO NORTH AND EAST OF THE MISSOURI RIVER...60S SOUTH AND WEST OF THE MISSOURI. RETURN FLOW/WAA TONIGHT AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE AMPLIFIES ACROSS THE ROCKIES TODAY THEN PROPAGATES EAST INTO THE HIGH PLAINS TONIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 348 AM CDT MON APR 21 2014 ACTIVE PERIOD EXPECTED WITH STRONG STORM SYSTEM APPROACHING THE REGION TUESDAY NIGHT. LARGE SURFACE LOW INITIALLY CENTERED OVER CENTRAL MONTANA 00Z WEDNESDAY TRANSITIONS TO DUAL SURFACE LOWS OVER SOUTHEASTERN SASKATCHEWAN AND SOUTHEAST MONTANA BY 12Z WED AS SHORTWAVE/90KT H250 JET STREAK ROTATE AROUND PARENT UPPER LOW. BREEZY TO WINDY EAST/SOUTHEAST WINDS WILL OCCUR ALSO WITH TIGHT SURFACE GRADIENT AND 850MB WINDS TO 45KTS LATE TUESDAY AND TUESDAY NIGHT. SPC CONTINUES TO INCLUDE THE WESTERN HALF OF THE STATE IN GENERAL THUNDERSTORM AREA WITH MODELS INDICATING LOW CAPE NUDGING INTO THIS REGION ALONG WITH H7-H5 LAPSE RATES APPROACHING 8C/KM TUESDAY NIGHT AHEAD OF THE COLD FRONT. MODELS CONTINUE TO SHOW HIGHEST QPF ACROSS NORTH AND EAST AS DRY SLOT IS MORE OF A FACTOR ACROSS WESTERN AND SOUTHERN AREAS. WEDNESDAY NIGHT INTO THURSDAY THE CLOSED UPPER LOW AND ASSOCIATED SURFACE LOW MOVE ACROSS THE NORTHERN PLAINS. MODEL DIFFERENCES INCREASE WITH THIS FEATURE WITH THE GFS A LITTLE FASTER AND FARTHER SOUTH COMPARED TO ECMWF. BOTH MODELS...HOWEVER...BRING SUB 0C H850 AIR ACROSS THE STATE IN NORTHERLY FLOW BEHIND THE SYSTEM THURSDAY NIGHT WITH LIGHT PRECIP IN THE FORM OF RAIN CHANGING TO SNOW FROM NORTH TO SOUTH. SUBSTANTIAL MODEL DIFFERENCES BY NEXT WEEKEND WITH GFS SHOWING STRONGER RIDGE AND DRYER WEATHER OVER ND ON SATURDAY WHILE ECMWF HAS LESS AMPLIFIED PATTERN AND ANOTHER BATCH OF PRECIP MOVING IN UNDER SOUTHWEST FLOW ALOFT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 625 AM CDT MON APR 21 2014 MVFR STRATUS CONTINUES TO PUSH SOUTH ACROSS NORTHERN AND CENTRAL NORTH DAKOTA AT THIS TIME...AND WILL CONTINUE TO DEVELOP SOUTH AND EAST THROUGH MID-MORNING. IMPACTED LOCATIONS INCLUDE KISN-KMOT-KJMS AND POSSIBLY KBIS. OTHERWISE VFR AT ALL TAF SITES THE REST OF THE 06Z FORECAST PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TM SHORT TERM...NH LONG TERM...JNS AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
625 AM CDT MON APR 21 2014 .UPDATE... ISSUED AT 625 AM CDT MON APR 21 2014 ONLY CHANGES TO FORECAST WERE TO POPULATE WITH LATEST HOURLY OBSERVATIONS. TEMPS WERE RUNNING A LITTLE COLDER THAN FORECAST IN A FEW LOCATIONS. OTHERWISE...LOW STRATUS CONTINUES TO SLOWLY PUSH SOUTHWARD WHICH IS HANDLED WELL IN FORECAST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 348 AM CDT MON APR 21 2014 NO MAJOR FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD. CURRENTLY...QUASI-ZONAL FLOW ACROSS THE NORTHERN PLAINS WITH A STRONG EMBEDDED S/WV TROUGH PUSHING EAST ALONG THE INTERNATIONAL BORDER...NOW CENTERED NEAR TO EAST OF LAKE WINNIPEG. WRAP AROUND MOISTURE IN THE FORM OF LOW LEVEL STRATUS SURGING SOUTH AND EAST ACROSS MY NORTHERN COUNTIES THE PAST COUPLE OF HOURS. AT THIS TIME DO NOT ANTICIPATE ANY PRECIPITATION ASSOCIATED WITH THE STRATUS. WILL CONTINUE TO MONITOR. LOW BKN-OVC CLOUDS WILL CONTINUE TO MOVE ACROSS NORTHWEST AND NORTH CENTRAL NORTH DAKOTA NOW THROUGH 10Z...EVENTUALLY DEPICTED BY BOTH THE RAP AND 00Z/06Z NAM TO PUSH AS FAR SOUTH AS BISMARCK AND JAMESTOWN 10-14Z. AFTERWARDS...STRATUS SHOULD DISSIPATE/BURN OFF BY THE EARLY AFTERNOON. THE MORNING CLOUDS COUPLED WITH CAA THE PAST SEVERAL HOURS WILL RESULT IN HIGH TEMPERATURES TODAY IN THE 50S ALONG TO NORTH AND EAST OF THE MISSOURI RIVER...60S SOUTH AND WEST OF THE MISSOURI. RETURN FLOW/WAA TONIGHT AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE AMPLIFIES ACROSS THE ROCKIES TODAY THEN PROPAGATES EAST INTO THE HIGH PLAINS TONIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 348 AM CDT MON APR 21 2014 ACTIVE PERIOD EXPECTED WITH STRONG STORM SYSTEM APPROACHING THE REGION TUESDAY NIGHT. LARGE SURFACE LOW INITIALLY CENTERED OVER CENTRAL MONTANA 00Z WEDNESDAY TRANSITIONS TO DUAL SURFACE LOWS OVER SOUTHEASTERN SASKATCHEWAN AND SOUTHEAST MONTANA BY 12Z WED AS SHORTWAVE/90KT H250 JET STREAK ROTATE AROUND PARENT UPPER LOW. BREEZY TO WINDY EAST/SOUTHEAST WINDS WILL OCCUR ALSO WITH TIGHT SURFACE GRADIENT AND 850MB WINDS TO 45KTS LATE TUESDAY AND TUESDAY NIGHT. SPC CONTINUES TO INCLUDE THE WESTERN HALF OF THE STATE IN GENERAL THUNDERSTORM AREA WITH MODELS INDICATING LOW CAPE NUDGING INTO THIS REGION ALONG WITH H7-H5 LAPSE RATES APPROACHING 8C/KM TUESDAY NIGHT AHEAD OF THE COLD FRONT. MODELS CONTINUE TO SHOW HIGHEST QPF ACROSS NORTH AND EAST AS DRY SLOT IS MORE OF A FACTOR ACROSS WESTERN AND SOUTHERN AREAS. WEDNESDAY NIGHT INTO THURSDAY THE CLOSED UPPER LOW AND ASSOCIATED SURFACE LOW MOVE ACROSS THE NORTHERN PLAINS. MODEL DIFFERENCES INCREASE WITH THIS FEATURE WITH THE GFS A LITTLE FASTER AND FARTHER SOUTH COMPARED TO ECMWF. BOTH MODELS...HOWEVER...BRING SUB 0C H850 AIR ACROSS THE STATE IN NORTHERLY FLOW BEHIND THE SYSTEM THURSDAY NIGHT WITH LIGHT PRECIP IN THE FORM OF RAIN CHANGING TO SNOW FROM NORTH TO SOUTH. SUBSTANTIAL MODEL DIFFERENCES BY NEXT WEEKEND WITH GFS SHOWING STRONGER RIDGE AND DRYER WEATHER OVER ND ON SATURDAY WHILE ECMWF HAS LESS AMPLIFIED PATTERN AND ANOTHER BATCH OF PRECIP MOVING IN UNDER SOUTHWEST FLOW ALOFT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 625 AM CDT MON APR 21 2014 MVFR STRATUS CONTINUES TO PUSH SOUTH ACROSS NORTHERN AND CENTRAL NORTH DAKOTA AT THIS TIME...AND WILL CONTINUE TO DEVELOP SOUTH AND EAST THROUGH MID-MORNING. IMPACTED LOCATIONS INCLUDE KISN-KMOT-KJMS AND POSSIBLY KBIS. OTHERWISE VFR AT ALL TAF SITES THE REST OF THE 06Z FORECAST PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JNS SHORT TERM...NH LONG TERM...JNS AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
348 AM CDT MON APR 21 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 348 AM CDT MON APR 21 2014 NO MAJOR FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD. CURRENTLY...QUASI-ZONAL FLOW ACROSS THE NORTHERN PLAINS WITH A STRONG EMBEDDED S/WV TROUGH PUSHING EAST ALONG THE INTERNATIONAL BORDER...NOW CENTERED NEAR TO EAST OF LAKE WINNIPEG. WRAP AROUND MOISTURE IN THE FORM OF LOW LEVEL STRATUS SURGING SOUTH AND EAST ACROSS MY NORTHERN COUNTIES THE PAST COUPLE OF HOURS. AT THIS TIME DO NOT ANTICIPATE ANY PRECIPITATION ASSOCIATED WITH THE STRATUS. WILL CONTINUE TO MONITOR. LOW BKN-OVC CLOUDS WILL CONTINUE TO MOVE ACROSS NORTHWEST AND NORTH CENTRAL NORTH DAKOTA NOW THROUGH 10Z...EVENTUALLY DEPICTED BY BOTH THE RAP AND 00Z/06Z NAM TO PUSH AS FAR SOUTH AS BISMARCK AND JAMESTOWN 10-14Z. AFTERWARDS...STRATUS SHOULD DISSIPATE/BURN OFF BY THE EARLY AFTERNOON. THE MORNING CLOUDS COUPLED WITH CAA THE PAST SEVERAL HOURS WILL RESULT IN HIGH TEMPERATURES TODAY IN THE 50S ALONG TO NORTH AND EAST OF THE MISSOURI RIVER...60S SOUTH AND WEST OF THE MISSOURI. RETURN FLOW/WAA TONIGHT AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE AMPLIFIES ACROSS THE ROCKIES TODAY THEN PROPAGATES EAST INTO THE HIGH PLAINS TONIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 348 AM CDT MON APR 21 2014 ACTIVE PERIOD EXPECTED WITH STRONG STORM SYSTEM APPROACHING THE REGION TUESDAY NIGHT. LARGE SURFACE LOW INITIALLY CENTERED OVER CENTRAL MONTANA 00Z WEDNESDAY TRANSITIONS TO DUAL SURFACE LOWS OVER SOUTHEASTERN SASKATCHEWAN AND SOUTHEAST MONTANA BY 12Z WED AS SHORTWAVE/90KT H250 JET STREAK ROTATE AROUND PARENT UPPER LOW. BREEZY TO WINDY EAST/SOUTHEAST WINDS WILL OCCUR ALSO WITH TIGHT SURFACE GRADIENT AND 850MB WINDS TO 45KTS LATE TUESDAY AND TUESDAY NIGHT. SPC CONTINUES TO INCLUDE THE WESTERN HALF OF THE STATE IN GENERAL THUNDERSTORM AREA WITH MODELS INDICATING LOW CAPE NUDGING INTO THIS REGION ALONG WITH H7-H5 LAPSE RATES APPROACHING 8C/KM TUESDAY NIGHT AHEAD OF THE COLD FRONT. MODELS CONTINUE TO SHOW HIGHEST QPF ACROSS NORTH AND EAST AS DRY SLOT IS MORE OF A FACTOR ACROSS WESTERN AND SOUTHERN AREAS. WEDNESDAY NIGHT INTO THURSDAY THE CLOSED UPPER LOW AND ASSOCIATED SURFACE LOW MOVE ACROSS THE NORTHERN PLAINS. MODEL DIFFERENCES INCREASE WITH THIS FEATURE WITH THE GFS A LITTLE FASTER AND FARTHER SOUTH COMPARED TO ECMWF. BOTH MODELS...HOWEVER...BRING SUB 0C H850 AIR ACROSS THE STATE IN NORTHERLY FLOW BEHIND THE SYSTEM THURSDAY NIGHT WITH LIGHT PRECIP IN THE FORM OF RAIN CHANGING TO SNOW FROM NORTH TO SOUTH. SUBSTANTIAL MODEL DIFFERENCES BY NEXT WEEKEND WITH GFS SHOWING STRONGER RIDGE AND DRYER WEATHER OVER ND ON SATURDAY WHILE ECMWF HAS LESS AMPLIFIED PATTERN AND ANOTHER BATCH OF PRECIP MOVING IN UNDER SOUTHWEST FLOW ALOFT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 348 AM CDT MON APR 21 2014 MVFR STRATUS SURGING SOUTH ACROSS NORTHERN NORTH DAKOTA AT THIS TIME...AND WILL CONTINUE TO DEVELOP SOUTH AND EAST THROUGH MID- MORNING. IMPACTED LOCATIONS INCLUDE KISN-KMOT-KJMS AND POSSIBLY KBIS. OTHERWISE VFR AT ALL TAF SITES THE REST OF THE 06Z FORECAST PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...NH LONG TERM...JNS AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
110 AM CDT MON APR 21 2014 .UPDATE... ISSUED AT 110 AM CDT MON APR 21 2014 FORECAST REMAINS MAINLY ON TRACK. MAIN UPDATE WAS TO INCREASE SKY COVER NORTH AS AN AREA OF LOW STRATUS PUSHES SOUTH FROM CANADA. THE LATEST RAP AND 00Z NAM ARE CAPTURING THESE CLOUDS VERY WELL SO LEANED HEAVILY ON THEIR FUTURE DEPICTION. STRATUS LOOKS TO LINGER THROUGH MID MORNING THEN SHOULD BURN OFF BY 17-18Z. UPDATE ISSUED AT 940 PM CDT SUN APR 20 2014 LOCAL RADARS SHOW THE NARROW BAND OF SHOWERS ASSOCIATED WITH THE COLD FRONT ARE JUST ABOUT OUT OF THE REGION. ANOTHER ONE OR TWO HOURS OF WIDELY SCATTERED SHOWERS IN THE NORTHERN JAMS RIVER VALLEY IS ABOUT IT. UPPER LOW CIRCULATION IN CANADA WITH H850 COLD ADVECTION SHOULD BRING IN SOME CLOUDS NORTH CENTRAL LATE TONIGHT. OTHERWISE MOSTLY CLEAR. LOWERED THE MIN TEMPS 2 TO 4 DEGREES CENTRAL AND EAST AS LOW RH/DRY AIR AND RAPIDLY DIMINISHING WINDS SHOULD ALLOW TEMPS TO FALL A BIT MORE TONIGHT. UPDATE ISSUED AT 624 PM CDT SUN APR 20 2014 AS OF 620 PM CDT...THE COLD FRONT HAS MOVE TO A RUGBY TO HARVEY TO LINTON LINE AND MOVING RAPIDLY EAST. ONLY SOME LIGHT SHOWERS NORTH BUT THE SHOWERS ARE ENHANCING THE WINDS A BIT NORTH CENTRAL DO TO EVAPORATIVE COOLING. WEST OF THE FRONT A WELL MIXED LAYER HAS RESULTED IN GUSTY NORTHWEST WINDS OF 25 TO 35 MPH. THESE ARE EXPECTED TO DIMINISH RAPIDLY AFTER SUNSET. ADJUSTED WINDS AND CLOUDS TO FOLLOW THE FRONT WITH THIS FORECAST && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 323 PM CDT SUN APR 20 2014 A COLD FRONT HAS ENTERED WESTERN NORTH DAKOTA THIS AFTERNOON. AHEAD OF THE FRONT...TEMPERATURES HAVE WARMED INTO THE 70S OVER CENTRAL NORTH DAKOTA...AND INTO THE UPPER 60S OVER NORTH CENTRAL NORTH DAKOTA. NO PRECIPITATION HAS DEVELOPED ALONG THE BOUNDARY JUST YET. HOWEVER...WILL MAINTAIN SLIGHT CHANCES FOR SHOWERS PRIMARILY OVER NORTHERN NORTH DAKOTA THROUGH THE LATE AFTERNOON/EARLY EVENING AS THE MAIN UPPER SHORTWAVE TRAVERSES THE INTERNATIONAL BOUNDARY. THE COMBINATION OF WARM TEMPERATURES AND BREEZY CONDITIONS WILL CONTINUE TO GENERATE A "VERY HIGH" FIRE DANGER OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON. DRY CONDITIONS ARE EXPECTED AREAWIDE OVERNIGHT. BOUNDARY LAYER WINDS AROUND 30 KNOTS SHOULD KEEP TEMPERATURES ABOVE NORMAL TONIGHT...WITH LOWS FORECAST TO RANGE FROM THE UPPER 30S TO LOW 40S. A DRY DAY IS FORECAST FOR MONDAY AS HIGH PRESSURE BUILDS INTO THE REGION. HOWEVER...COOLER CANADIAN AIR IS EXPECTED TO ROTATE SOUTH BEHIND THE DEPARTING UPPER SHORTWAVE ACROSS WESTERN AND CENTRAL NORTH DAKOTA MONDAY. TEMPERATURES SHOULD BE ABOUT A CATEGORY ABOVE NORMAL...WITH HIGHS RANGING FROM THE UPPER 50S TO LOW 60S. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 323 PM CDT SUN APR 20 2014 THE HIGHLIGHTS OF THE EXTENDED FORECAST ARE A POTENTIAL STORM SYSTEM FOR TUESDAY NIGHT INTO THURSDAY...FOLLOWED BY BELOW NORMAL TEMPERATURES. THE 12 UTC GUIDANCE SUITE CONTINUES TO SUGGEST SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS WESTERN AND CENTRAL NORTH DAKOTA TUESDAY NIGHT INTO WEDNESDAY MORNING ALONG AND AHEAD OF AN OCCLUDING WARM FRONT SUPPORTED BY A STRONG LOW LEVEL JET AND STEEP MID LEVEL LAPSE RATES. THE THREAT FOR SHOWERS AND THUNDERSTORMS DURING THE DAY ON WEDNESDAY IS FORECAST TO BE FOCUSED ACROSS THE NORTH THROUGH THE JAMES RIVER VALLEY AS A DRY SLOT BEGINS TO OVERTAKE THE WEST. THE 12 UTC SUITE...COMPARED TO YESTERDAY...SUGGESTS THIS DRY SLOT WILL OVERTAKE MUCH OF WESTERN AND CENTRAL NORTH DAKOTA WEDNESDAY NIGHT INTO THURSDAY...RESULTING IN SIGNIFICANTLY LESS QPF. PRECIPITATION CHANCES INCREASE ONCE AGAIN DURING THE SECOND HALF OF THURSDAY AS A STRONG COLD FRONT IS FORECAST TO PROPAGATE SOUTH OUT OF CANADA. THEREAFTER...WELL BELOW NORMAL HIGHS IN THE 40S ARE FORECAST FRIDAY INTO NEXT WEEKEND AS A COLD...STRONG SURFACE HIGH BUILDS INTO THE NORTHERN PLAINS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 110 AM CDT MON APR 21 2014 A TROUGH OF LOW PRESSURE ACROSS SOUTHERN CANADA IS FORECAST TO MOVE SOUTH INTO NORTH DAKOTA MONDAY MORNING. THIS WILL BRING SOME STRATO-CUMULUS CLOUDS INTO THE NORTHWEST AND NORTH CENTRAL BETWEEN NOW AND 12Z. SCT-BKN CLOUDS 1-3 THOUSAND FOOT AGL EXPECTED FOR THE MORNING HOURS KISN-KMOT...POSSIBLY KJMS. OTHERWISE VFR AT ALL TAF SITES. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH SHORT TERM...TM LONG TERM...AYD AVIATION...NH/WAA
AREA FORECAST DISCUSSION
NWS MEDFORD OR
847 AM PDT MON APR 21 2014 .SHORT TERM...A SERIES OF UPPER LEVEL TROUGHS IS EXPECTED TO MOVE ACROSS THE REGION THIS WEEK BRINGING PRECIPITATION AND UNSETTLED WEATHER. THIS MORNING, AN UPPER TROUGH IS LOCATED OFF THE PACNW COAST AND A FRONT IS JUST OFFSHORE. AHEAD OF THE FRONT, SOUTHERLY MOISTURE AND AREA OF VORTICITY WILL MOVE ACROSS THE CWA. THIS WILL BRING SOME PRE-FRONTAL SHOWERS, MAINLY ALONG THE CASCADES AND SISKIYOUS. THEN LATE IN THE AFTERNOON AND IN THE EVENING, EXPECT THE FRONT TO BEGIN TO MOVE INLAND SPREADING STRATIFORM PRECIPITATION ACROSS THE AREA THROUGH TONIGHT. THE FORECAST REMAINS ON TRACK WITH THE FRONTAL SYSTEM MOVING INLAND TONIGHT. AHEAD OF THE FRONT, HAVE INCREASED THE CHANCE FOR SHOWERS ALONG THE CASCADES AND SISKIYOUS. ALSO HAVE ADDED A WIND ADVISORY FOR THE SUMMER LAKE AREA FOR LATE THIS AFTERNOON AND THIS EVENING. THE NAM, RAP AND GFS MODELS SHOW A 40 TO 50 KT SOUTHWEST JET MOVING INTO THE AREA DURING THIS PERIOD. GUIDANCE ALSO INDICATES GUSTS NEAR 45 MPH FOR THE SUMMER LAKE AREA LATE THIS AFTERNOON INTO THIS EVENING. EXPECT THE MAIN AREA FOR GUSTY SOUTHWEST WINDS WILL OCCUR FROM PAISLEY NORTH ALONG HIGHWAY 31 NEAR SUMMER LAKE. OTHER AREAS THAT WILL SEE WINDS GUSTING TO 45 MPH WILL BE OVER THE MOUNTAINS IN LAKE COUNTY. && .AVIATION...BASED ON 21/12Z TAF CYCLE...A FRONT WILL BRING SOME RAIN TO THE COAST LATE THIS AFTERNOON...AND PRECIPITATION WILL SPREAD INLAND DURING THE EVENING. EXPECT CIGS TO LOWER TO MVFR AT MOST WEST SIDE LOCATIONS DURING THIS TIME FRAME...AND LOWERED FLIGHT CONDITIONS AND PRECIPITATION SHOULD REMAIN IN PLACE THROUGH THE REMAINDER OF THE TAF PERIOD. EAST SIDE AND NORCAL LOCATIONS WILL LIKELY REMAIN VFR THROUGH MONDAY...BUT GUSTY WINDS WILL DEVELOP IN THE AFTERNOON. SOME AREAS OF MVFR CEILINGS AND VISIBILITIES COULD DEVELOP OVER THE EAST SIDE LATE TONIGHT. FREEZING LEVELS WILL DROP RAPIDLY BEHIND THE FRONT...REACHING DOWN TO 3000 TO 4000 FEET ABOVE MSL BY 12 UTC TONIGHT. -BPN && .MARINE...WEST SWELLS WILL CONTINUE TO GRADUALLY SUBSIDE THROUGH TONIGHT AND EVENTUALLY STABILIZE AT AROUND 10 FEET ON MONDAY. VARIOUS SWELL TRAINS WILL MOVE THROUGH THE AREA...KEEPING SEAS AT AROUND 10 FEET THROUGH WEDNESDAY. A WEAK FRONT WILL PASS OVER THE WATERS TODAY...PRODUCING LIGHT NORTH WINDS (15-20 KT) BEHIND IT INTO MONDAY EVENING. A STRONGER FRONT IS EXPECTED WEDNESDAY AND THIS WILL BRING SOLID SMALL CRAFT ADVISORY WINDS TO ALL WATERS WITH GALES POSSIBLE OVER THE WATERS NORTH OF CAPE BLANCO. THE MODELS ARE STARTING TO SHOW SOME CONSISTENCY WITH THIS SOLUTION...THUS WILL PROBABLY NEED TO HOIST A GALE WATCH OVER THE NEXT COUPLE OF MODEL CYCLES IF THIS TREND HOLDS. THURSDAY AND FRIDAY LOOK QUIET...BUT ANOTHER MODERATELY STRONG FRONT IS POSSIBLE THIS WEEKEND AND PERHAPS ANOTHER EARLY NEXT WEEK. -WRIGHT/BPN && .PREV DISCUSSION... /ISSUED 353 AM PDT MON APR 21 2014/ DISCUSSION...THE COLD FRONT IS MOVING INTO THE COASTAL WATERS THIS MORNING. THIS FRONT IS ON TRACK TO BRING GUSTY WINDS TO THE HIGHER TERRAIN OF THE WEST SIDE AND VERY GUSTY WINDS IN THE KLAMATH AND GOOSE LAKE BASINS THIS AFTERNOON AND EVENING. SO FAR WIND SPEEDS DON`T APPEAR TO BE STRONG ENOUGH FOR A WIND ADVISORY BUT THIS BEARS WATCHING NONETHELESS. HOWEVER WINDS ARE FORECAST TO BE VERY STRONG AT THE UPPER HALF OF MOUNT SHASTA (50+ MPH) AND ANY HIKERS NEED TO TAKE THIS INTO CONSIDERATION. SHORT TERM GUIDANCE DOES NOT BRING RAIN TO INLAND VALLEYS UNTIL LATE AFTERNOON. THIS LOOKS REASONABLE AS UPPER LEVEL STEERING FLOW IS ALMOST PARALLEL TO THE FRONT. ALSO WITH LACK OF STRONG SOUTHEAST WINDS..WE SHOULD SEE MINIMUM DOWNSLOPING EFFECT AND THE ROGUE VALLEY COULD SEE RAIN ALONG THE FRONT AS IT MOVES INLAND THIS EVENING. THE FRONT MAY ALSO HAVE A FEW WAVES DEVELOP ALONG THE FRONT WHICH SHOULD HELP SLOW THE EASTWARD PROGRESSION. TONIGHT A SERIES OF STRONG WILL MOVE INLAND. THE UPPER LEVEL TROUGH ASSOCIATED WITH THIS SYSTEM IS FAIRLY DEEP AND SHOWS A NEGATIVELY TILTED PROFILE. THERE WILL ALSO BE A STRONG ONSHORE FLOW WHICH WILL HELP ENHANCE PRECIPITATION ACROSS OUR FORECAST AREA. BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT ON RAINFALL AMOUNTS AND TIMING. RAINFALL AMOUNTS UP TO HALF AN INCH OF RAIN IN THE PARTS OF THE ROGUE AND UMPQUA VALLEYS ARE NOT UNREASONABLE FOR TONIGHT TIME FRAME. PRECIPITATION IS MUCH LIGHTER EAST OF THE CASCADES OVERNIGHT BUT THE KLAMATH BASIN IS EXPECTED TO PICK UP TOWARD TUESDAY MORNING. SNOW LEVELS WILL REMAIN RATHER HIGH TONIGHT AND THIS SHOULD NOT AFFECT TRAVEL ACROSS THE MAJOR PASSES. COOLER NORTHWEST FLOW WILL BRING SNOW LEVELS DOWN ON TUESDAY. CURRENT FORECAST CALLS FOR THE SNOW LEVELS TO LOWER TO AROUND 3500 TO 4000 FEET TUESDAY. THIS WILL DEFINITELY IMPACT TRAVELS ACROSS THE CASCADES WITH A FEW INCHES OF SNOW POSSIBLE AND LESSER IMPACT OVER THE SISKIYOU PASSES. WEAK SHORT WAVE RIDGING MOVES INTO THE AREA TUESDAY AFTERNOON THROUGH TUESDAY NIGHT. PRECIPITATION CHANCE DECREASES SOMEWHAT BUT THIS WILL BE SHORT LIVED AS A WARM FRONT WILL BRING ANOTHER ROUND OF RAIN TO THE COAST WEDNESDAY. THIS WARM FRONT WILL BRING VERY GUSTY WINDS TO THE COASTAL AREA WEDNESDAY WITH RAIN SPREADING INLAND. SNOW LEVELS WILL RISE ON WEDNESDAY. THE SECOND HALF OF THE WEEK COULD SEE SIGNIFICANT RAIN AT LEAST FOR SOUTHWEST OREGON AND NORTHERN CALIFORNIA WITH HIGH LEVEL OF MOISTURE TRANSPORT FROM THE PACIFIC. /FB && .MFR WATCHES/WARNINGS/ADVISORIES... OR...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 11 PM PDT THIS EVENING FOR ORZ030-031. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 PM PDT WEDNESDAY FOR PZZ350-356-370-376. $$ CC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
852 PM EDT TUE APR 22 2014 .SYNOPSIS... A COLD FRONT WILL CLEAR CENTRAL PENNSYLVANIA THIS EVENING...ENDING ANY LINGERING SHOWER OR THUNDERSTORM ACTIVITY BY EARLY TO MID EVENING. MUCH COLDER AIR WILL WORK INTO THE COMMONWEALTH LATER TONIGHT AND WEDNESDAY...WITH LAKE EFFECT SNOW SHOWERS OVER THE NORTHWEST AND WEST CENTRAL MOUNTAINS AND FLURRIES POSSIBLE OVER THE REST OF THE CENTRAL AND NORTHERN MOUNTAINS. COOL AND DRY WEATHER IS EXPECTED TO CONTINUE THURSDAY...AS A RIDGE OF HIGH PRESSURE SLIDES OVER THE AREA. THE NEXT COLD FRONT AND CHANCE FOR SHOWERS WILL ARRIVE ON FRIDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... MID LVL SHORTWAVE AND ASSOC SFC COLD FRONT PUSHING THRU CENTRAL PA THIS EVENING...ACCOMPANIED BY A FAIRLY SOLID LINE OF SHOWERS AND TSRA. THE TSRA ARE CONCENTRATED PRIMARILY ACROSS THE LAUREL HIGHLANDS...WHERE 20Z SPC MESOANALYSIS SHOWS CAPES ARND 500 J/KG. MARGINAL INSTABILITY WILL LIMIT THE SVR THREAT. HOWEVER...SMALL HAIL ALREADY REPORTED ARND JOHNSTOWN AND RAP DATA SHOWS FAIRLY STRONG WINDS BTWN 1-3KM...WHICH COULD EASILY MIX TO THE SFC IN STRONGER CONVECTIVE CELLS. COLD FRONT AND ASSOC CONVECTION SHOULD PASS EAST OF THE CWA ARND OR SHORTLY AFTER 00Z. MUCH COLDER AIR DIVES INTO WEST CENTRAL PA BY 00Z WED...WITH 850 MB READINGS PLUNGING BELOW ZERO. GUSTY POST-FRONTAL WNW FLOW WILL INCREASE THROUGH WEDNESDAY AND HELP DIRECT AN ABNORMALLY COOL CANADIAN AIRMASS INTO THE AREA WHICH WILL LAST THROUGH THURSDAY MORNING. WELL ALIGNED NW FLOW WILL COMBINE WITH 850 MB TEMPS FALLING TO AROUND -3 TO -4C TONIGHT TO BRING SCATTERED SNOW SHOWERS TO THE NW MTNS AND LAURELS OVERNIGHT TONIGHT...WITH A LIGHT COATING POSSIBLE AT ELEVATIONS GENERALLY AOA 1500 FT MSL. A FEW FLURRIES WILL LIKELY SPILL OFF THE ALLEGHENY FRONT AND INTO THE CENTRAL RIDGE AND VALLEY REGION AFTER MIDNIGHT TONIGHT. LOW TEMPS TONIGHT WILL VARY FROM THE LOWER TO MID 30S ACROSS THE MOUNTAINS...TO BETWEEN 40-45F THROUGHOUT THE SUSQ VALLEY. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... STRATOCU WILL LINGER ACROSS THE NRN AND WESTERN MTNS FOR WEDNESDAY WITH SCATTERED MAINLY MORNING SNOW SHOWERS /MIXED WITH RAIN IN THE VALLEYS/...WHILE MOSTLY SUNNY SKIES DEVELOP ACROSS THE LOWER SUSQ VALLEY. VRBL AMOUNTS OF STRATO CU WILL OCCUR ACROSS THE CENTRAL RIDGE AND VALLEY REGION. IT WILL BE BREEZY TO LOCALLY WINDY WITH SUSTAINED WINDS OF 12 TO 18 MPH AND GUSTS TO 30 MPH IN THE AFTERNOON. HIGH TEMPS ON WEDNESDAY /IN THE MID AND UPPER 40S ACROSS THE NW MTNS AND LAURELS...AND UPPER 50S TO AROUND 60 IN THE SE/ WILL AVG 5-10 DEGREES BELOW NORMAL. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... WILL KEEP THIS SHORT...WATCHING LOW TOPPED STORMS ON RADAR. SOME SMALL HAIL REPORTED SW OF OUR AREA. ANYWAY...NOT MANY CHANGES FROM RECENT DAYS. AIRMASS QUITE COLD FOR WED...THUS DID LOWER TEMPS WED NIGHT SOME. LOOKING AT A SUNNY BUT BREEZY DAY ON THU...AS A LARGE STORM SYSTEM REMAINS JUST OFFSHORE. STILL LOOKING AT SHOWERS ON FRIDAY...WITH THE NEXT SYSTEM. DID NOT ADD THUNDER AT THIS POINT...AS THE TRIPLE POINT LOOKS TO BE JUST SOUTH OF CENTRAL PA. TEMPS WILL BE ON THE MILD SIDE...GIVEN WARM ADVECTION AND TEMPS AT 850 MB. DID CUT BACK ON SHOWERS FOR SATURDAY NIGHT...GIVEN NW FLOW AND SPREAD IN MODELS. WENT WITH A DRY FORECAST FOR SUNDAY INTO MONDAY. HOWEVER...DID LOWER TEMPS SOME MONDAY...GIVEN THE AIRMASS IN PLACE AND NE TO SE FLOW. LARGE CUTOFF TO THE SW NEXT WEEK WITH A REX BLOCK. THERE COULD BE SOME SHOWERS LATE TUE. POTENTIAL FOR A SEVERAL DAY PERIOD OF WET AND COOL WEATHER. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... A STRONG COLD FRONT CROSSING CENTRAL PA THIS EVENING WILL EXIT THE STATE BY MIDNIGHT. ISOLD SHOWERS/TSRA ACCOMPANYING THE FRONT WITH BRIEF WIND GUSTS HAVE EXITED MAJORITY OF CENTRAL PA...BUT A FEW WILL REMAIN FOR THE NEXT COUPLE OF HOURS. BEHIND THE FRONT...NW WINDS OFF LAKE ERIE WILL PRODUCE MVFR/IFR CIGS OVERNIGHT WITH ISOLD SHRA FROM KBFD TO KJST. SPEED OF THE NORTHWESTERLY SFC WINDS /15-20KTS WITH GUSTS TO 30KTS/ COULD ALSO BE A CONCERN TO FLYING INTERESTS. MVFR/IFR CONTINUES INTO WED IN WEST AND NORTH...WITH A BREEZY NW WIND. OUTLOOK... WED...MVFR NORTH/WEST WITH SCT -SHRA...VFR ELSEWHERE. BREEZY NW WINDS. THU...VFR. NO SIG WX. FRI-SAT...MVFR WITH CHC SHRA. SUN...VFR. NO SIG WX. && .FIRE WEATHER... MIN RHS DROP TO THE UPPER 20S ACROSS PORTIONS OF THE SOUTH CENTRAL MOUNTAINS AND LOWER SUSQ RIVER VALLEY WEDNESDAY AFTERNOON. WNW WINDS OF 12 TO 18 MPH WITH GUSTS TO 30 MPH ARE EXPECTED ALONG WITH FINE FUEL MOISTURES IN THE UPPER SINGLE DIGIT PERCENTILES. THROUGH COLLABORATION WITH BOF OFFICIALS AND SURROUNDING NWS OFFICES...HAVE ISSUED FIRE WEATHER WATCH FROM 15Z WED TO 00Z THU FROM BEDFORD COUNTY EASTWARD TO LANCASTER COUNTY AND NORTHWARD TO PERRY...DAUPHIN AND LEBANON COUNTIES ON WEDNESDAY. && .CTP WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR PAZ034>036-056-057-059-063>066. && $$ SYNOPSIS...DEVOIR NEAR TERM...DEVOIR/FITZGERALD SHORT TERM...DEVOIR LONG TERM...MARTIN AVIATION...DEVOIR/GARTNER FIRE WEATHER...DEVOIR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
128 AM EDT MON APR 21 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN ACROSS THE AREA BEFORE A COLD FRONT CROSSES EAST ON TUESDAY. DRY HIGH PRESSURE BUILDS BACK IN WEDNESDAY AND THURSDAY WITH ANOTHER COLD FRONT AFFECTING THE REGION ON FRIDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 130 AM...A QUIET NEAR TERM IS EXPECTED...AS SHARP UPR RIDGE AXIS TRANLATES EAST ACRS THE CWFA. AN INVERTED SFC RIDGE AXIS ALSO REMAINS INVOF THE REGION...RESULTING IN LGT NE FLOW EAST OF THE MTNS AND DRY CONDITIONS. THERE MAY BE SOME PATCHY FROST IN THE NORTHERN MTNS...BUT NOTHING WIDESPREAD ACRS THE REST OF THE HIGH TERRAIN TO WARRANT A FROST ADVISORY. TEMPS CURRENTLY LOOK ON TRACK. AS OF 1030 PM...NC PIEDMONT STRATOCU HAS BEEN STEADILY OOZING AWAY FROM THE FORECAST AREA THIS EVENING...SO THE SKY COVER FORECAST HAS BEEN LOWERED ACROSS OUR SOUTHEAST TIER OF ZONES. OTHERWISE... PRIMARILY THIN CIRRUS WILL PASS OVER THE REGION THROUGH THE OVERNIGHT...BUT THIS IS NOT EXPECTED TO HAVE A MAJOR IMPACT ON THE NOCTURNAL COOLING CYCLE. WITH LIGHT MIXING EXPECTED IN THE PIEDMONT TONIGHT...MIN TEMPS ARE EXPECTED TO AVERAGE JUST A LITTLE BELOW NORMAL...WHILE SHELTERED MTN VALLEYS WILL AVERAGE AT LEAST 5 DEGREES BELOW CLIMO. IN FACT...IT APPEARS PATCHY FROST IS LIKELY IN SHELTERED AREAS OF THE SRN/CTRL MTNS MONDAY MORNING...AND WE HAVE ADDED THIS TO THE FORECAST. IN ADDITION...VALLEY FOG LOOKS LIKE A DECENT BET...PRIMARILY IN THE LITTLE TENN BASIN AND ADJACENT DRAINAGES. AS OF 750 PM SUNDAY...OTHER THAN PATCHY STRATOCU ACROSS THE EXTREME SE TIER OF ZONES...SKIES ARE CLEAR ACROSS THE AREA AT MID-EVENING. MODEL SOLUTIONS ARE QUITE DISPARATE REGARDING THE EVOLUTION OF THIS STRATOCU LAYER OVERNIGHT...WITH THE NAM BEING SOMEWHAT OF AN OUTLIER IN DRAGGING IT WEST TO ENCOMPASS MUCH OF THE NC PIEDMONT/EASTERN SC PIEDMONT LATER THIS EVENING. IN LIGHT OF THIS...HAVE OPTED TO INTRODUCE SKY COVER AT THE MOSTLY CLEAR/PARTLY CLOUDY END OF THE SPECTRUM ACROSS THE EASTERN THIRD OF THE AREA. AS OF 150 PM EDT SUNDAY...WITH THE UPPER LOW SLOWLY MOVING OUT TO SEA...ONLY THE FAR EASTERN ZONES SHOULD SEE ANY CLOUD COVER THIS EVENING. THE NAM IS QUITE AGGRESSIVE IN BRINGING CLOUDS INTO THE WRN NC PIEDMONT...BUT AS THE GFS AND RUC DO NOT DO THIS...I/VE GONE WITH A SKY FORECAST CLOSER TO THE DRIER MODELS. THERE SHOULD BE MORE LOCALLY DENSE FOG IN THE SOUTHWEST IN MTN VALLEYS OVERNIGHT. DRY AIR AND WEAK MIXING SHOULD KEEP MOST OTHER LOCATIONS ACROSS THE FA FROM SEEING ANY FOG OVERNIGHT. MIN TEMPS WILL BE COOL...BUT THEY SHOULD BE WARM ENOUGH TO PREVENT FROST OVER ALL BUT SOME OF THE INTERIOR NORTHERN MOUNTAIN VALLEYS. MONDAY WILL BE SEASONABLY MILD WITH INCREASING HIGH CLOUDS DURING THE AFTERNOON HOURS. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... AS OF MIDDAY SUNDAY...UPPER PATTERN BEGINS TO AMPLIFY ACRS THE ERN CONUS MON NIGHT AS DEEP RIDGE PUSHES INTO THE GREAT PLAINS. CORE OF TROUGH BEGINS TO DIG ACRS THE GREAT LAKES...AND SFC LOW SUBSEQUENTLY DEVELOPS AND MOVES INTO NEW ENGLAND DURING THE DAY TUE. THE TRAILING COLD FRONT IS STILL PROGGED TO ENTER OUR CWFA AT THAT TIME...MOVING OUT TUE EVENING. WE WILL BE WELL SOUTH OF THE BETTER FORCING THOUGH SOME DPVA IS PROGGED AS THE AXIS OF THE BROAD TROUGH PASSES. FRONTOGENESIS AND LLVL CONVERGENCE FIELDS ARE MURKY...SO PRECIP CHANCES MOSTLY RESULT FROM DECENT PREFRONTAL INSTABILITY. CAPE PROFILES ARE SKINNY ON PROG SOUNDINGS AND DEEP SATURATION IS INITIALLY EVIDENT. SHEAR PARAMETERS CONTINUE TO PROMPT LITTLE CONCERN...BUT IN THE WAKE OF THE UPPER TROUGH DRYING RAPIDLY OCCURS ABV 700 MB. THIS OCCURS IN THE MID TO LATE AFTN WHEN SOME SFC BASED INSTABILITY IS STILL PRESENT. THUS SOME OF THE LATER STORM ACTIVITY COULD POSE A MICROBURST AND DAMAGING WIND THREAT...MAINLY OVER THE PIEDMONT. TEMPS MON NIGHT AND TUE WILL BE A CATEGORY OR TWO ABOVE NORMAL. DEEP LAYER DRYING CONTINUES TUE NIGHT AS PLAINS RIDGE MOVES INTO THE ERN US...AND SKIES WILL CLEAR OVERNIGHT...PERHAPS MORE SLOWLY IN THE MTNS WHERE A VERY SHALLOW SFC BASED MOIST LAYER REMAINS IN NW FLOW. BRISK WINDS ARE LIKELY IN THE HIGH ELEVATIONS AT THAT TIME BUT THESE SUBSIDE TOWARD DAWN WED. DRY AND MOSTLY CLEAR CONDITIONS PERSIST THRU WED WITH SUBSIDENCE INVERSION ACRS THE FA BUT LACKING MOISTURE ANYWAY. THICKNESSES DO DROP A BIT FOR WED...RETURNING TEMPS TO AROUND NORMAL DESPITE PRIME INSOLATION. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 230 PM EDT SUNDAY...THE EXTENDED RANGE PERIOD INITIALIZES ON WEDNESDAY EVENING AS DEEP LAYER RIDGING PREVAILS ACROSS THE SOUTHEAST. A SURFACE HIGH DIVING OUT OF ONTARIO WILL QUICKLY TRANSITION TO A BERMUDA TYPE HIGH BY THURSDAY AFTERNOON SETTING UP RETURN FLOW. MEANWHILE...A NORTHERN STREAM LOW AMPLITUDE UPPER TROF WILL PUSH THROUGH THE NORTHERN PLAINS WITH SURFACE CYCLOGENESIS OCCURRING OVER THE CENTRAL PLAINS. A COLD FRONT WILL PUSH THROUGH THE MISSISSIPPI RIVER VALLEY ON THURSDAY EVENING AS THE PARENT SURFACE CYCLONE EJECTS NORTHEAST INTO THE GREAT LAKES REGION. ABOVE MENTIONED HIGH PRESSURE WILL PREVAIL ACROSS THE SOUTHERN APPALACHIANS...AHEAD OF THE APPROACHING FRONT ON FRIDAY MORNING/AFTERNOON. A WARM FRONT WILL SURGE NORTHWARD FROM THE GULF AND WESTERN ATLANTIC SOURCE REGIONS ALLOWING FOR INCREASING DEWPOINTS AND STEEPENING LAPSE RATES DURING THE AFTERNOON HOURS. THIS WILL LEAD TO MODEST INSTABILITY ACROSS THE CWFA WITH GFS/ECMWF SOLUTIONS INDICATIVE OF SBCAPE IN EXCESS OF 1000J/KG WITH ENOUGH SHEAR TO SUPPORT SOME ORGANIZED CONVECTION. STILL TOO MUCH UNCERTAINTY TO DIAL IN ON STORM MODES AND SPECIFIC TIMING/INTENSITY. HOWEVER...CURRENT FCST SOUNDINGS DO INDICATE PW VALUES APPROACHING 1.5 INCHES LEADING TO MODERATELY HEAVY RAIN RATES WITH CAPE PROFILES SUPPORTIVE OF LARGE HAIL. DUE TO UNCERTAINTY...CAPPED POPS AT HIGH END CHANCE LEVELS ACROSS THE REGION FOR FRIDAY. THE FRONT WILL PASS INTO THE COASTAL PLAINS/MIDLANDS BY EARLY MORNING SATURDAY LEADING TO A DRY FCST UNTIL SUNDAY AFTERNOON. AT THAT TIME POPS SLOWLY RAMP UP ACROSS THE WESTERNMOST ZONES AS ANOTHER SYSTEM MOVES THROUGH THE MIDSOUTH AND INTO THE TENNESSEE VALLEY. TEMPERATURES THROUGH THE EXTENDED RANGE PERIOD WILL REMAIN AT OR JUST ABOVE NORMAL LEVELS DESPITE THE FROPA FRIDAY EVENING. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AT KCLT...A QUIET TAF PERIOD AS SFC HIGH PRES AXIS TRANSLATES ACRS THE AREA...WITH GENERALLY SKC OR FEW/SCT250 THRU THE PERIOD. LGT WINDS WILL FAVOR A NE DIRECTION UNTIL ABOUT NOON...THEN BECOME VARIABLE DURING THE AFTN BEFORE SWITCHING TO SW. ELSEWHERE...SIMILAR TO KCLT ABOVE...WITH LGT NE WINDS OR VARIABLE THRU MID MORNING...THEN FAVORING SW BY EARLY AFTN. FCST SNDGS SHOW POSSIBLE SOME HIGH-BASED CUMULUS DEVELOPING ACRS THE NC MTNS AND INTO THE UPSTATE LATE AFTN/EARLY EVENING...BUT OTHERWISE CIRRUS ONLY CLOUDS EXPECTED THRU THE PERIOD. OUTLOOK...A FAIRLY WET FRONTAL SYSTEM...WITH PIEDMONT THUNDERSTORMS...IS EXPECTED ON TUE...WITH DRYING RETURNING MID WEEK. CONFIDENCE TABLE... 05-11Z 11-17Z 17-23Z 23-05Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...SBK NEAR TERM...ARK/JDL/MCAVOY SHORT TERM...WIMBERLEY LONG TERM...CDG AVIATION...ARK
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1227 AM CDT MON APR 21 2014 .UPDATE... SEE UPDATED AVIATION DISCUSSION BELOW. CURRENT RADAR SHOWS AN AREA OF TSTORMS MOVING THROUGH LYMAN AND SOUTHERN HUGHES COUNTY. LIKE THE HRRR DEPICTION OF CONVECTIVE PROGRESSION EASTWARD SO NUDGED POPS A BIT TO REFLECT THE 21Z GUIDANCE. EVEN THOUGH RADAR IS ALSO SHOWING SOME WEAK RETURNS ACROSS THE EASTERN CWA KEPT THIS AREA DRY. DUE TO THE 35 DEGREE DEWPOINT SPREAD AND THE LACK OF ANY STRONG ECHOES THIS ACTIVITY IS LIKELY ALL VIRGA IN THE EAST FOR NOW. DROPPED OVERNIGHT LOWS ABOUT FIVE DEGREES IN THE NORTH...FROM THE JAMES VALLEY TO CORSON COUNTY. EVEN WITH MOISTER AID ADVECTING IN FROM THE WEST ACROSS THE SOUTH...NORTHERN UPSTREAM OBS HAVE DEWPOINTS IN THE 20S TO LOWER 30S WHICH SHOULD ALLOW TEMPERATURES TO TANK AFTER SUNSET SINCE WINDS ARE LIGHT. && .PREVIOUS DISCUSSION... .SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT A WEAK LOW PRESSURE SYSTEM AND ASSOCIATED COOL FRONT WILL TRACK ACROSS THE AREA TONIGHT. FAIRLY WARM TEMPERATURES HAVE AIDED IN A LITTLE INSTABILITY DEVELOPMENT ACROSS THE SOUTHERN PORTION OF THE STATE...AND MAY SEE SOME SHOWER AND THUNDERSTORM DEVELOPMENT THIS EVENING OVER THE SOUTHERN CWA. MOISTURE IS PRETTY LIMITED...SO NOT ANTICIPATING ANY SEVERE WEATHER. HIGH PRESSURE MOVES IN BEHIND THE EXITING LOW ON MONDAY. EVEN THOUGH TEMPERATURES WILL BE A BIT COOLER...DECENT MIXING WILL BRING BREEZY TO WINDY CONDITIONS TO THE EASTERN CWA...AND WITH THE DRIER AIR IN PLACE...THE POTENTIAL IS THERE FOR FIRE WEATHER ISSUES. THEREFORE...HAVE ISSUED A FIRE WEATHER WATCH FOR THE EASTERN CWA...INCLUDING THE TWO MINNESOTA COUNTIES FOR MONDAY AFTERNOON. AFTER THAT...THINGS STAY QUIET UNTIL TUESDAY NIGHT WHEN WARM FRONTAL RAIN SHOWERS LOOK TO AFFECT MUCH OF THE CWA AHEAD OF ANOTHER APPROACHING LOW...ALONG WITH GUSTY WINDS SPREADING FROM WEST TO EAST. WITH THE HIGH DOMINANT ON MONDAY...SLIGHTLY COOLER TEMPS IN THE 60S WILL BE COMMON FOR HIGHS...WITH JUST A BIT OF A RISE IN HIGHS ON TUESDAY...MAINLY MID 60S TO LOWER 70S. OVERNIGHT LOWS WILL BE MAINLY IN THE 40S TONIGHT AND TUESDAY NIGHT...WITH COOLER 30S EXPECTED MONDAY NIGHT. .LONG TERM...WEDNESDAY THROUGH SUNDAY THE MEDIUM RANGE MODELS CONTINUE TO SHOW A PROGRESSIVE PATTERN THROUGH THE EXTENDED PERIOD. TIMING OF PRECIP WILL BE TRICKY AS DETAILS DIFFER ALONG WITH THE PRESENCE OF A DRY SLOT WEDNESDAY AND THURSDAY AS THE UPPER LOW PUSHES INTO NE MT. HAVE TRENDED THUNDERSTORM CHANCES HIGHEST IN THE EAST WHERE DRY SLOT INFLUENCE APPEARS TO BE NOT AS STRONG. MODELS DIFFER ON WHAT THIS UPPER WILL DO...EC HAS IT WEAKENING THEN REORGANIZING IT OVER NORTHERN MN. EXPECT SHOWERS ON BACKSIDE OF LOW FRIDAY. CONFIDENCE LOW ON POSITION OF DRY SLOT AT THIS TIME BUT WILL HAVE TO BE WATCHED AS IT WILL PLAY A BIG ROLE ON WHAT AREAS STAY ON THE DRIER SIDE. THE UPPER RIDGE LOOKS TO POP BACK INTO THE AREA SATURDAY WITH SHOWERS AND THUNDERSTORMS DEVELOPING AGAIN SATURDAY AFTERNOON/NIGHT AS FLOW QUICKLY BECOMES SOUTHWEST ALOFT. TEMPS WILL HAVE A HARD TIME REBOUNDING IN THE RIDGE WITH COOLER AIR IN PLACE AND A QUICK RETURN OF CLOUDS AND PRECIPITATION CHANCES. && .AVIATION... 06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. A WEAK FRONT IS MOVING THROUGH THE REGION OVERNIGHT TURNING WINDS TO THE NORTHWEST. THE FRONT HAS ALREADY PASSED THROUGH ALL SITES EXCEPT KATY WHICH SHOULD EXPERIENCE VERY GUSTY WINDS WITH FROPA BRIEFLY BETWEEN 6Z AND 8Z. NORTHWEST WINDS WILL BECOME GUSTY AT 15 TO 30 KTS AT ALL SITES BY LATE MORNING MONDAY. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...FIRE WEATHER WATCH FROM THIS AFTERNOON THROUGH THIS EVENING FOR PRAIRIE COTEAU-RED RIVER VALLEY-UPPER JAMES RIVER. MN...FIRE WEATHER WATCH FROM THIS AFTERNOON THROUGH THIS EVENING FOR BIG STONE-TRAVERSE. && $$ UPDATE...WISE SHORT TERM...PARKIN LONG TERM...SCARLETT AVIATION...TDK WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1155 PM CDT SUN APR 20 2014 .UPDATE... ISSUED AT 911 PM CDT SUN APR 20 2014 BAND OF SHOWERS AND THUNDERSTORMS ALONG FRONT AND LOW HAS BEEN EXPANDING OVER THE WESTERN EDGE OF OUR FORECAST AREA. THIS IS IN LINE WITH CURRENT PROJECTIONS BY THE HRRR AND EVEN THE RAP. LESS CERTAIN IS HOW ACTIVITY WILL BEHAVE SOUTHEAST...IN NORTHWEST IOWA...HAVING UNDERGONE A DECREASE LAST HOUR OR TWO...BUT EXPECT SOME SEPARATE REGENERATION THERE AS THE LOW/FRONT APPROACH. ANYWAY...THE MAIN CHANGE FOR NOW IS TO INCREASE POPS/COVERAGE OF THE SHOWERS AND STORMS NORTH FROM THE EARLIER SLIGHT CHANCE. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 406 PM CDT SUN APR 20 2014 ELEVATED BAND OF SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPING IN NORTHEAST NEBRASKA THIS AFTERNOON AND GRADUALLY WORKING/DEVELOPING NORTHEAST. NOT ANTICIPATING A WHOLE LOT OF ACTIVITY FROM THIS CONVECTION BUT SHOULD PRODUCE SOME ISOLATED TO SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. ANOTHER AREA LIKELY TO PRODUCE ISOLATED ACTIVITY WILL BE IN CENTRAL SD NEAR AN INCOMING WEAK CONVERGENT BOUNDARY. UPPER LEVEL SUPPORT NOT TOO GOOD AND DRY LOW LEVELS SUGGEST THAT MAYBE NOTHING WILL GET GOING BUT STILL WORTH AN ISOLATED THREAT AT THIS POINT. THE MAIN AREA TO FOCUS ON WILL AGAIN BE NORTHWEST IOWA WHERE THERE IS A BETTER COMBINATION OF UPPER LEVEL FORCING...INSTABILITY AND AND LOW TO MID LEVEL FRONT. WILL KEEP LIKELIES GOING AND ALSO THE IDEA THAT SEVERE THUNDERSTORMS WILL NOT BE A THREAT. CAPE VALUES MAY APPROACH 500 TO 1000 J/KG THIS EVENING BUT WITH THE MODELS OVERDOING THE LOW LEVEL MOISTURE THOSE VALUES COULD BE A BIT PESSIMISTIC. THE BETTER CHANCES FOR PRECIPITATION SHOULD SHIFT SOUTHEAST OF THE AREA LATE TONIGHT AS THE UPPER LEVEL WAVE TO THE NORTH BRINGS IN DRIER AND MORE STABLE AIR. LOWS LIKELY TO RANGE FROM THE MID 40S IN THE NORTHERN CWA TO THE MID 50S IN PARTS OF NORTHWEST IOWA. THIS DRIER AND MORE STABLE AIR MASS WILL ALSO COME WITH A WELL MIXED ATMOSPHERE AND DECENT PRESSURE GRADIENT WHICH WILL LEAD TO A WINDY MONDAY IN MOST LOCATIONS. RECENT TRENDS IN GUIDANCE HAS BEEN TO FORECAST DEW POINT TEMPERATURES TOO HIGH...ESPECIALLY IN A WELL MIXED ENVIRONMENT SO WENT MUCH CLOSER TO THE BIAS CORRECTED OUTPUT WHICH HAS BEEN HANDLING OUR DRY GROUND BETTER AS THE MODELS SEEM TO BE HAVING TROUBLE WITH OUR DRIER THAN NORMAL BOUNDARY LAYER. SO...BECAUSE OF THE LOW DEW POINTS AND HIGH WINDS WENT AHEAD AND ISSUED A FIRE WEATHER WATCH FOR MOST OF THE AREA AS AFTERNOON HUMIDITY VALUES LIKELY TO FALL BELOW 25 PERCENT IN MANY LOCATIONS AS HIGHS CLIMB INTO THE UPPER 60S TO LOWER 70S. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 406 PM CDT SUN APR 20 2014 HIGH PRESSURE WILL CONTINUE TO EASE SOUTHWARD INTO THE REGION ON MONDAY NIGHT. DIMINISHING WINDS AND MAINLY CLEAR SKIES...ALONG WITH A DRIER AIRMASS SHOULD LEAD TO LOWS TOWARD THE LOWER END OF THE FORECAST ENVELOPE...MAINLY MID TO UPPER 30S. BY TUESDAY...UPPER LEVEL RIDGING WILL BUILD EASTWARD ACROSS THE AREA ALONG WITH AN EASTWARD RETURN OF A FAIRLY STRONG MID LEVEL FRONTAL ZONE. MOISTURE IS PRETTY ANEMIC THROUGH THE DAY AT LOWER LEVELS... BUT ELEVATED PARCELS AROUND 700 HPA OR A BIT HIGHER DO INDICATE SOME CONVECTIVE INSTABILITY. HAVE NOT INCLUDED ANY PRECIPITATION WORKING SLOWLY EASTWARD ACROSS THE CWA...BUT WOULD CERTAINLY THINK AT LEAST A COUPLE OF SPRINKLES WOULD ACCOMPANY THE THICKENING MID CLOUDS THROUGH THE DAY TOWARD AT LEAST I29 BY LATE DAY. SHADED DEWPOINT FORECAST TOWARD DRIER RAW PROFILES...AS HAS BEEN THE CASE OF LATE. STRONG LOW LEVEL JET OF 50 TO 60 KNOTS DEVELOPS ON TUESDAY NIGHT WITH MOISTURE SURGE WORKING RAPIDLY NORTHWARD FROM THE SOUTHERN HIGH PLAINS. FAIRLY GOOD WAVE MOVING THROUGH RIDGE DURING THE NIGHT...MAIN CONVERGENCE WITH LOW LEVEL JET ESTABLISHES NORTH...BUT CONTINUED MID LEVEL INSTABILITY WITH 8-9C/KM AND INCREASING MOISTURE SUGGESTS A BETTER COVERAGE OF SHOWERS AND ISOLATED THUNDER WITH TIME OVERNIGHT. WINDS WILL ALSO BECOME AN ISSUE LATER IN THE NIGHT...AND COULD GET SOMEWHAT CLOSE TO WIND ADVISORY NEAR AND WEST OF I 29...AND EXPANDING OVER MUCH OF THE AREA DURING THE DAY ON WEDNESDAY. LAPSE RATES REMAIN STEEP INTO THE DAYTIME...BUT GRADUALLY MODIFY A BIT MIDDAY WITH WARMER LAYER ALOFT BUILDING IN...WHICH COULD WORK TO SLOW UP OR EVEN END CONVECTION FROM SOUTHWEST TO NORTHEAST DURING THE MORNING AND LINGERING INTO THE AFTERNOON. SHOULD KEEP A FAIR AMOUNT OF CLOUDS AROUND WITH STRONG LOW LEVEL JET...ESPECIALLY ACROSS SOUTHWEST MINNESOTA INTO NORTHWEST IOWA. IF IT BREAKS OUT... COULD BE APPRECIABLY WARMER AND GENERATE MORE INSTABILITY BY WEDNESDAY AFTERNOON...TO CORRELATE WITH APPROACH OF STRONGER UPPER LIFT FORCING AND CONVERGENT BOUNDARY TOWARD THE JAMES VALLEY BY LATER IN THE DAY. WOULD CERTAINLY MAINTAIN AT LEAST A SMALL SEVERE WEATHER THREAT GIVEN THE SHEAR AND INSTABILITY POTENTIAL...ESPECIALLY FROM THE LOWER JAMES AND BIG SIOUX VALLEY EASTWARD. TROUGH WILL LIFT PAST WEDNESDAY NIGHT...WITH DYNAMICS SUPPORTIVE OF HIGHER POPS EAST OF THE JAMES RIVER...AND ESPECIALLY ACROSS NORTHWEST IOWA. PRECIP THREAT GRADUALLY TAPERING OFF WEST TO EAST OVERNIGHT...LINGERING IN THE FAR EASTERN CWA INTO THURSDAY MORNING. UPPER LOW CONTINUES TO DEEPEN AND CLOSE OFF NORTHEAST OF THE AREA ON THURSDAY...PLACING AREA IN A MORE SUBSIDENT FAVORED QUADRANT WITH MOISTURE DISPLACED TO THE NORTH/EAST. HAVE TRIMMED BACK POPS SOMEWHAT...ESPECIALLY THROUGH THE MISSOURI VALLEY...AND TAKEN TEMPS CLOSER THE 850 HPA MIXING OF DRIER SOLUTIONS. HANDLING OF THE INTENSE UPPER TROUGH...AND NEXT ONE LATER IN THE WEEKEND...IS WIDELY VARIED BETWEEN MODELS AND LEADS TO QUITE LOW CONFIDENCE IN THE OVERALL PATTERN FROM FRIDAY THROUGH SUNDAY. COULD EVEN FIND THREAT FOR A LITTLE SNOWFALL WITHOUT STRAYING TOO FAR FROM A COUPLE SOLUTIONS...BUT WAY TOO FAR OUT TO PUT ANY FAITH IN THE FORECAST. DOES APPEAR AS IF IT WILL BE AN ACTIVE TIME LATER IN THE WEEKEND...AND WITH THE ABUNDANCE OF CLOUDS AND OR COOLER AIR IN PLACE...HAVE KEPT NEAR TO A BIT ON THE COOLER SIDE OF GUIDANCE FOR THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1155 PM CDT SUN APR 20 2014 VFR CONDITIONS WILL PREVAIL FOR THE REMAINDER OF TONIGHT THROUGH MONDAY NIGHT. THERE WILL BE SCATTERED SHOWERS AND THUNDERSTORMS MOVING ACROSS THE FORECAST AREA FOR THE REMAINDER OF TONIGHT...BUT WILL BE EAST OF THE KHON TAF SITE. TIMED THE CONVECTION FOR THE KFSD AND KSUX TAF SITES BETWEEN 06Z AND 12Z AND WILL MONITOR FOR ANY ALTERATIONS. OTHERWISE THERE WILL BE FREQUENT GUSTS BETWEEN 25 AND 30 KNOTS ALONG AND EAST OF THE JAMES RIVER VALLEY DURING THE LATE MORNING AND AFTERNOON ON MONDAY. && .FIRE WEATHER... ISSUED AT 406 PM CDT SUN APR 20 2014 A STRONG NORTHWEST WIND WILL DEVELOP THROUGH THE MORNING ON MONDAY IN A WELL MIXED ATMOSPHERE...LEADING TO DANGEROUS FIRE WEATHER CONDITIONS. AFTERNOON RELATIVE HUMIDITIES WILL LIKELY DROP TO BETWEEN 20 AND 25 PERCENT OF THE ENTIRE AREA WITH WINDS AVERAGING ABOUT 20 TO 30 MPH AND A FEW GUSTS AROUND 35 MPH. SOUTH CENTRAL SD WILL SEE WINDS MORE IN LINE WITH 15 TO 25 MPH AND WITH EXPECTED RELATIVE HUMIDITY VALUES ABOVE 20 PERCENT A VERY HIGH FIRE DANGER WILL BE MAINTAINED. THIS MOST DANGEROUS FIRE WEATHER CONDITIONS SHOULD BE FROM ABOUT 100 PM TO 700 PM ON MONDAY. DEW POINTS MAY END UP JUST A BIT HIGHER BUT THE TRENDS SO FAR THIS SPRING HAVE BEEN FOR THE GUIDANCE TO OVER FORECAST DEW POINTS BY ABOUT 3 TO 6 DEGREES SO TOOK THIS INTO ACCOUNT. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR SDZ256>258. MN...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR MNZ900. IA...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR IAZ300-301. NE...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR NEZ249. && $$ UPDATE... SHORT TERM...08 LONG TERM...CHAPMAN AVIATION...MJ FIRE WEATHER...08
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
313 PM CDT MON APR 21 2014 .DISCUSSION... FORECAST REASONING WILL LEAN TOWARD A CONSENSUS MODEL SOLUTION COMPROMISE FOR THE FORECAST PERIOD UNLESS OTHERWISE NOTED. FORECAST QUANDARIES...WX PATTERN TONIGHT THRU TUE...WX PATTERN LATE THIS WEEKEND INTO THE FIRST PART OF NEXT WEEK...TEMPS. MODELS CONTINUING THEIR RECENT TREND OFF OVERALL WEAKENING OF THE FRONTAL SYSTEM EXPECTED TO BEGIN TO INFLUENCES THE MID STATE`S WX TONIGHT...STILL LOOKING LIKE IT WILL BE MAINLY AFTER MIDNIGHT... AS A SFC COLD FRONT APPROACHES THE MID STATE FROM THE NW BY 22/12Z. LATEST SHORT RANGE MODELS INCLUDING THE HRRR SHOWING EVEN THE POSSIBILITY OF THIS ACTIVITY MAINLY MOVING S OF THE MID STATE TOO. ALTHOUGH MODEL SOUNDING SHOWING LITTLE IN THE WAY OF OVERALL ATM INSTABILITY...WITH UPPER LEVEL TROUGH PASSAGE EXPECTED ACROSS MOST OF THE MID STATE BY 22/12Z ALSO...CAN NOT RULE OUT A RUMBLE OF THUNDER HERE OR THERE MAINLY AFTER MIDNIGHT TONIGHT...BUT BELIEVE THAT MOST OF THE ACTIVITY WILL BE IN THE FORM OF SHWRS MAINLY AFTER MIDNIGHT ALSO. AS FOR RAINFALL AMOUNTS...EXPECT GENERALLY LESS THAN ONE HALF OF AN INCH IN MOST LOCATIONS. AS FOR TEMPS...WITH ADDITIONAL CLOUD COVERAGE...RAINFALL...AND A CONTINUANCE OF SWLY WIND FLOW EXPECTED...TAPPING INTO A SLIGHTLY WARMER AIRMASS TO OUR SW ALSO...WILL GO CLOSE TO AN MOS GUIDANCE CONSENSUS SOLUTION. EXPECT NUMEROUS SHWRS AND ISO TSTMS TO CONTINUE ACROSS THE MID STATE DURING THE MORNING HRS ON TUE AS SFC FRONT MOVES THRU THE MID STATE DURING THE MORNING HRS...WITH A SLIGHT CHANCE OF SHWRS/TSTMS POSSIBLY PERSISTING ACROSS THE PLATEAU AND SRN COUNTIES. EXPECT A SLIGHT COOL DOWN IN HIGHS FROM THIS AFTERNOON`S VALUES...AND WILL AGAIN GO CLOSE TO CONSENSUS MODEL REASONING ON TEMPS...WITH HIGHS MAINLY IN THE LOWER 70S. RIDGING INFLUENCES SFC AND ALOFT WILL PROVIDE DRY CONDITIONS WITH LOWS MAINLY IN THE LOWER 40S WED MORNING...HIGHS NEAR SEASONABLE NORMAL VALUES ON WED...AND A RETURN TO TEMPS MAINLY IN THE LOW TO MID 40S ON WED NIGHT. TAKING A LOOK AT THE REST OF THE FORECAST PERIOD...THU THRU THE FIRST PORTION OF NEXT WEEK...STILL EXPECTING A FRONTAL SYSTEM TO MOVE THRU THE MID STATE MAINLY ON THU NIGHT...WITH SOME STRONG TSTMS POSSIBLE... BUT MODEL TRENDING TOWARD THIS POSSIBILITY BECOMING MORE AND MORE ISO IN NATURE. AFTER THE FRONTAL PASSAGE DURING THE MORNING HRS ON FRI... CANADIAN BASED SFC RIDGING INFLUENCES SHOULD PROVIDE FOR DRY CONDITIONS THRU AT LEAST THE FIRST HALF OF SUN. THERE HAVE BEEN SOME DIFFERENCES IN THE MODELS AS OF LATE DEALING WITH THE OVERALL WX PATTERN FOR THE SECOND HALF OF SUN INTO THE FIRST PART OF NEXT WEEK...BUT MODEL GUIDANCE STARTING TO COME MORE IN LINE WITH EACH OTHER. SHWRS/TSTMS SHOULD AGAIN DEVELOP ON SUN NIGHT/MON AS A WELL ORGANIZED FRONTAL SYSTEM PUSHES A WARM FRONT FROM THE S INTO THE MID STATE PUTTING THE MID STATE IN THE BROAD WARM SECTOR OF THIS DEVELOPING POTENTIALLY STRONG FRONTAL SYSTEM. AS FOR TEMPS...HIGHS WILL CONTINUE AT LEAST SLIGHTLY ABOVE SEASONAL NORMAL VALUES THRU SAT...MAINLY IN THE MID TO UPPER 70S...COOLING BACK TO MORE SEASONABLE NORMAL VALUES BY THE FIRST PART OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 60 72 44 69 / 60 60 0 0 CLARKSVILLE 58 72 41 69 / 60 20 0 0 CROSSVILLE 56 70 39 66 / 60 60 0 0 COLUMBIA 60 73 45 71 / 60 60 0 0 LAWRENCEBURG 59 73 44 73 / 60 60 0 0 WAVERLY 59 72 42 70 / 60 50 0 0 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION
NWS AMARILLO TX
102 AM CDT MON APR 21 2014 .UPDATE... QUICK UPDATE TO THE FORECAST TO INCORPORATE PATCHY DENSE FOG ACROSS THE SOUTH CENTRAL TEXAS PANHANDLE. THE LOWEST VISIBILITIES HAVE BEEN CONFINED TO THE CITY OF AMARILLO AND HAVE BEEN FLUCTUATING BETWEEN 1/2 AND 1/4 MILE. EXPECT THE FOG TO DISSIPATE BY 8 AM AT THE LATEST ONCE WINDS SHIFT TO THE NORTH AND INCREASE. UPDATED TEXT PRODUCTS SENT. && .PREV DISCUSSION... /ISSUED 1138 PM CDT SUN APR 20 2014/ AVIATION... 06Z TAF CYCLE LOW CLOUDS AND FOG HAVE DEVELOPED NEAR OR AT THE AMARILLO TAF SITE BACK SOUTHEAST INTO THE SOUTHEAST TEXAS PANHANDLE. THE LATEST HRRR FORECASTING THE LOW CLOUDS AND FOG CONTINUING TO DEVELOP NORTH AND WEST TOWARD THE GUYMON TAF SITE BY 07Z TO 09Z MONDAY. IFR TO VLIFR CONDITIONS COULD DEVELOP AT BOTH THE AMARILLO AND GUYMON TAF SITES BETWEEN 06Z AND 10Z MONDAY. THE HRRR SHOWING THE LOW CLOUDS AND FOG DISSIPATING FROM WEST TO EAST AWAY FROM BOTH TAF SITES AROUND 10Z TO 12Z MONDAY AS A COLD FRONT AND DRIER AIR PUSHES SOUTH AND EAST. THE LOW CLOUDS AND FOG NOT EXPECTED TO REACH AS FAR WEST AS THE DALHART TAF SITE WHERE VFR CONDITIONS PREVAIL THROUGH 06Z TUESDAY. VFR CONDITIONS ARE EXPECTED TO RETURN TO THE AMARILLO AND GUYMON TAF SITES BY 10Z TO 12Z MONDAY. WINDS SHOULD BECOME EAST AND SOUTHEAST 5 TO 15 KNOTS AT THE GUYMON AND AMARILLO TAF SITES THROUGH 10Z TO 12Z MONDAY...THEN SHIFTING TO THE NORTHWEST AND NORTH AS THE COLD FRONT MOVES THROUGH AND INCREASING TO 15 TO 25 KNOTS WITH HIGHER GUSTS. THE WINDS WILL VEER AROUND TO THE NORTHEAST AND DIMINISH AFTER 20Z MONDAY 5 TO 10 KNOTS OR LESS. AT THE DALHART TAF SITE...WINDS WILL REMAIN WEST TO NORTHWEST 5 TO 10 KNOTS THEN SHIFTING TO THE NORTH 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 10Z TO 12Z MONDAY AFTER THE COLD FRONT MOVES THROUGH...THEN VEERING AROUND TO THE NORTHEAST AND EAST AFTER 20Z MONDAY 5 TO 15 KNOTS. SCHNEIDER PREV DISCUSSION... /ISSUED 1046 PM CDT SUN APR 20 2014/ UPDATE... CONVECTION HAS PUSHED EAST OF MOST OF THE PANHANDLES LATE THIS EVENING. A FEW LINGERING SHOWERS ACROSS THE FAR EASTERN TX PANHANDLE WILL PUSH EAST OF THE AREA BY MIDNIGHT...WITH DRY CONDITIONS EXPECTED OVERNIGHT. UPDATED FORECAST TO REFLECT THESE TRENDS. KB PREV DISCUSSION... /ISSUED 616 PM CDT SUN APR 20 2014/ AVIATION... 00Z TAF CYCLE SCATTERED CONVECTION ACROSS THE PANHANDLES MAY AFFECT THE THREE TAF SITES THROUGH 01Z TO 02Z MONDAY. VFR CONDITIONS WILL PREVAIL ALONG WITH SOUTHWESTERLY TO WESTERLY WINDS BECOMING NORTH BEHIND A COLD FRONT LATER TONIGHT AND EARLY MONDAY. THE FRONT IS EXPECTED TO MOVE THROUGH THE DALHART AND GUYMON TAF SITES AROUND 08Z TO 12Z MONDAY...AND THEN ACROSS THE AMARILLO TAF SITE BY 14Z TO 15Z MONDAY. NORTHERLY TO NORTHEASTERLY WINDS WILL INCREASE TO AROUND 15 TO 25 KNOTS WITH HIGHER GUSTS BEHIND THE FRONT AND THEN DIMINISHING TO 10 TO 15 KNOTS AFTER 20Z MONDAY. SCHNEIDER PREV DISCUSSION... /ISSUED 330 PM CDT SUN APR 20 2014/ DISCUSSION... ONLY MINOR CHANGES HAVE BEEN MADE TO THE FORECAST. HAVE INCREASED POPS THIS EVENING ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA... CLOSER TO PROXIMITY OF INCOMING UPPER-LEVEL JET STREAK...IN REGION OF GREATER INSTABILITY. POPS AFTER MIDNIGHT HAVE BEEN TRIMMED TO INCLUDE ONLY FAR EASTERN SECTIONS...AHEAD OF DEPARTING VORTICITY MAXIMUM. MONDAY AND TUESDAY EXPECTED TO BE DRY AND MILD. LOW-LEVEL JET DEVELOPS TUESDAY NIGHT AHEAD OF NEXT MID-LEVEL TROF. WEDNESDAY AFTERNOON CHANCES FOR STRONG TO SEVERE THUNDERSTORMS HAVE BEEN INCREASED SLIGHTLY AND SPREAD A BIT FARTHER WEST DUE TO EXPECTED POSITION OF DRYLINE. WEDNESDAY EVENING POPS HAVE BEEN KEPT IN EASTERN SECTIONS HAVE ALSO BEEN INCREASED SLIGHTLY...AND HAVE ALSO BEEN SPREAD A BIT FARTHER WEST. NO POPS IN REMAINDER OF FORECAST. NO FREEZING TEMPERATURES EXPECTED. 03 COCKRELL FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH TUESDAY. CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE ON WEDNESDAY ACROSS THE WESTERN HALF OF THE PANHANDLES. ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE ON SATURDAY ACROSS THE WESTERN HALF OF THE PANHANDLES. ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ON SUNDAY ACROSS THE WESTERN TWO THIRDS OF THE PANHANDLES. 03 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 09/14
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1141 PM CDT SUN APR 20 2014 .AVIATION... SHOWERS AND THUNDER JUST ABOUT TO AN END ACROSS THE AREA... CERTAINLY FINISHED AT BOTH TEMINALS...AS THE UPPER TROUGH THAT SPAWNED THEM SHIFTS EWD INTO OKLAHOMA. LINGERING LOW LEVEL MOISTURE ACROSS THE ROLLING PLAINS AND ERN PANHANDLE WITH SOME PATCHY LOW CLOUDS NOTED ON SATELLITE WHERE CIRRUS HAS CLEARED. COULD SEE SOME PERIODS OF MVFR...IF NOT IFR...CIGS AT KCDS BEFORE A COLD FRONT ARRIVES TOWARD 13Z. ON THE CAPROCK AT KLBB WINDS ALREADY FROM THE WEST WITH MODEST DRY ADVECTION LIKELY TO KEEP LOW LEVEL MOISTURE AND LOW CLOUDS EAST OF THE TERMINAL. && .PREV DISCUSSION... /ISSUED 624 PM CDT SUN APR 20 2014/ AVIATION... UPPER LOW MOVING ACROSS THE PANHANDLE ATTM WITH SCATTERED SHOWERS AND ISOLATED THUNDER UNDERNEATH IT. CONVECTION SHOULD SHIFT TO THE EAST OF THE AREA BY 03Z. THREAT OF THUNDER AT EITHER TERMINAL IS NON-ZERO BUT NOT BIG ENOUGH TO RUN WITH A PREVAILING OR TEMPO GROUP ATTM. VFR CONDITIONS LIKELY THROUGH THE NIGHT WITH SMALL CHANCE FOR SOME FOG AND/OR LOW CLOUDS AHEAD OF A COLD FRONT TOWARD 12Z...AGAIN THE CHANCE OF WHICH IS TOO SMALL TO INSERT MENTION INTO EITHER TAF. FINALLY...WIND SWITCH TO NORTH WITH THE COLD FRONT MONDAY MORNING. PREV DISCUSSION... /ISSUED 337 PM CDT SUN APR 20 2014/ SHORT TERM... VIS SAT SHOWS A LINE OF CU DEVELOPING IN THE WESTERN TX PANHANDLE AND IS GRADUALLY PUSHING EASTWARD WHILE DEVELOPING SOUTHWARD. A FEW RETURNS HAVE SHOWED UP ON RADAR OVER PARMER COUNTY WHICH IS RIGHT IN LINE WITH THIS CU DEVELOPMENT. THIS IS MOST LIKELY ASSOCIATED WITH THE /DRY/ LINE AS SURFACE OBS INDICATE A SURFACE TROF IN THE AFOREMENTIONED AREA WITH WESTERLY WINDS AND SLIGHTLY DRIER DEWPOINTS MOVING IN BEHIND THE TROF. THE DRY LINE WILL CONTINUE WITH ITS EAST/SOUTHEASTWARD MOVEMENT AS THE UPPER LEVEL LOW TO OUR NORTHWEST MOVES CLOSER. CURRENT RAP ANALYSIS INDICATES THAT COLDER AIR ALOFT IS PUSHING IN AND IS INCREASING OUR LAPSE RATES. SCATTERED SKIES ARE HELPING AID SOME SURFACE HEATING IN TURN HELPING TO SLOWLY ERODE WHAT CAP IS LEFT. AS CLEARER SKIES MOVE EASTWARD THIS SHOULD HELP WARM THE SURFACE MORE TO THE POINT OF FULL CAP EROSION. THIS WILL HELP FIRE CONVECTION MORE QUICKLY AS THE DRYLINE MOVES INTO THE CENTRAL SOUTH PLAINS AND TX PANHANDLE. FORECAST SOUNDINGS CONTINUE TO INDICATE THE POTENTIAL FOR STRONG TO SVR CONVECTION WITH CHANCES INCREASING THROUGH THE AFTERNOON/EVENING EASTWARD. WHILE CAPE THERMO PROFILES ARE ADEQUATE TO PRODUCE SVR HAIL AND WINDS...0-6KM SHEAR IS HIGH END MARGINAL TOPPING OUT AT AROUND 40 KTS OVER THE ROLLING PLAINS AND 35 KTS ALONG THE I27/HWY84 CORRIDOR. I HAVE KEPT INHERITED POPS BEFORE 00Z WITH SVR MENTION AND INCREASED COVERAGE TO 50 POPS OVER THE ROLLING PLAINS FOR LATER TONIGHT. PRECIP/CONVECTION CHANCES WILL QUICKLY DIMINISH AS THE DRY LINE/UPPER LEVEL LOW MOVES EASTWARD AND AS A WEAK FRONT PUSHING INTO THE AREA TOMORROW MORNING. TEMPS WILL BE WARM IN THE MID 70S TO 80S TOMORROW AS CAA WILL BE WEAK AND SHORT LIVED DURING THE MORNING AND SKIES WILL CLEAR MAKING WAY FOR SOLAR HEATING. ALDRICH LONG TERM... LITTLE CHANGE FOR THE EXTENDED PORTION OF THE FORECAST THIS GO AROUND. WE CONTINUE TO LOOK FOR WARMER TEMPS AND A RETURN TO SOUTH BREEZES TUESDAY AS SHORTWAVE RIDGE BRIEFLY TRANSITS WTX DOWNSTREAM OF A FAIRLY DEEP TROUGH MOVING ACROSS THE WEST. FAIRLY ROBUST MOISTURE RETURN IS EXPECTED TUESDAY NIGHT ON THE NOSE OF THE LLJ. THE GFS AND ECMWF REMAIN IN DECENT AGREEMENT THAT AS THE SHORTWAVE TROUGH CROSSES THE ROCKIES...A DRYLINE SHOULD DEVELOP ACROSS THE SRN PLAINS. MODELS ARE STILL IN FLUX WITH THE EAST-WEST POSITION OF THE DRYLINE BY PEAK HEATING...BUT IT APPEARS LIKELY IT WILL BE SOMEWHERE IN THE VICINITY OF THE CAPROCK ESCARPMENT. WE CONTINUE TO CARRY A SLIGHT CHANCE OF TSTMS TO THE EAST OF THE DRYLINE...AND HAVE BUMPED POPS UP SLIGHTLY INTO THE CHANCE CATEGORY ACROSS THE NE ZONES. A WEAK COLD FRONT WILL FOLLOW ON THURSDAY...ALTHOUGH IT MAY NOT PASS THROUGH THE ENTIRE CWA BEFORE LIFTING. ANOTHER LARGE TROUGH WILL FOLLOW FOR NEXT WEEKEND...ALTHOUGH THERE CONTINUES TO BE A LOT OF UNCERTAINTY REGARDING THE STRENGTH AND ORIENTATION OF THE MID-LVL FLOW ACROSS THE SRN PLAINS AND WHETHER OR NOT WE CAN HOLD ON TO LOW-LVL MOISTURE. DRYLINE ACTIVITY MAY BE POSSIBLE SAT AND SUN ACROSS ERN ZONES...BUT HAVE MAINTAINED POPS BELOW MENTION FOR NOW. AFTER A BRIEF COOL DOWN MOST AREAS ON THURSDAY....TEMPS SHOULD BE A LITTLE ABOVE NORMAL HEADING INTO THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 50 74 51 79 52 / 10 10 0 0 0 TULIA 51 76 50 80 55 / 30 10 0 0 0 PLAINVIEW 53 78 51 81 56 / 20 10 0 0 0 LEVELLAND 54 80 54 82 59 / 10 10 0 0 0 LUBBOCK 55 81 56 81 60 / 20 10 0 0 0 DENVER CITY 55 78 55 82 61 / 10 10 0 0 0 BROWNFIELD 54 79 56 83 60 / 10 10 0 0 0 CHILDRESS 58 82 56 82 57 / 50 10 0 0 0 SPUR 58 83 57 82 60 / 40 10 0 0 0 ASPERMONT 60 85 58 83 61 / 40 10 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1138 PM CDT SUN APR 20 2014 .AVIATION... 06Z TAF CYCLE LOW CLOUDS AND FOG HAVE DEVELOPED NEAR OR AT THE AMARILLO TAF SITE BACK SOUTHEAST INTO THE SOUTHEAST TEXAS PANHANDLE. THE LATEST HRRR FORECASTING THE LOW CLOUDS AND FOG CONTINUING TO DEVELOP NORTH AND WEST TOWARD THE GUYMON TAF SITE BY 07Z TO 09Z MONDAY. IFR TO VLIFR CONDITIONS COULD DEVELOP AT BOTH THE AMARILLO AND GUYMON TAF SITES BETWEEN 06Z AND 10Z MONDAY. THE HRRR SHOWING THE LOW CLOUDS AND FOG DISSIPATING FROM WEST TO EAST AWAY FROM BOTH TAF SITES AROUND 10Z TO 12Z MONDAY AS A COLD FRONT AND DRIER AIR PUSHES SOUTH AND EAST. THE LOW CLOUDS AND FOG NOT EXPECTED TO REACH AS FAR WEST AS THE DALHART TAF SITE WHERE VFR CONDITIONS PREVAIL THROUGH 06Z TUESDAY. VFR CONDITIONS ARE EXPECTED TO RETURN TO THE AMARILLO AND GUYMON TAF SITES BY 10Z TO 12Z MONDAY. WINDS SHOULD BECOME EAST AND SOUTHEAST 5 TO 15 KNOTS AT THE GUYMON AND AMARILLO TAF SITES THROUGH 10Z TO 12Z MONDAY...THEN SHIFTING TO THE NORTHWEST AND NORTH AS THE COLD FRONT MOVES THROUGH AND INCREASING TO 15 TO 25 KNOTS WITH HIGHER GUSTS. THE WINDS WILL VEER AROUND TO THE NORTHEAST AND DIMINISH AFTER 20Z MONDAY 5 TO 10 KNOTS OR LESS. AT THE DALHART TAF SITE...WINDS WILL REMAIN WEST TO NORTHWEST 5 TO 10 KNOTS THEN SHIFTING TO THE NORTH 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 10Z TO 12Z MONDAY AFTER THE COLD FRONT MOVES THROUGH...THEN VEERING AROUND TO THE NORTHEAST AND EAST AFTER 20Z MONDAY 5 TO 15 KNOTS. SCHNEIDER && .PREV DISCUSSION... /ISSUED 1046 PM CDT SUN APR 20 2014/ UPDATE... CONVECTION HAS PUSHED EAST OF MOST OF THE PANHANDLES LATE THIS EVENING. A FEW LINGERING SHOWERS ACROSS THE FAR EASTERN TX PANHANDLE WILL PUSH EAST OF THE AREA BY MIDNIGHT...WITH DRY CONDITIONS EXPECTED OVERNIGHT. UPDATED FORECAST TO REFLECT THESE TRENDS. KB PREV DISCUSSION... /ISSUED 616 PM CDT SUN APR 20 2014/ AVIATION... 00Z TAF CYCLE SCATTERED CONVECTION ACROSS THE PANHANDLES MAY AFFECT THE THREE TAF SITES THROUGH 01Z TO 02Z MONDAY. VFR CONDITIONS WILL PREVAIL ALONG WITH SOUTHWESTERLY TO WESTERLY WINDS BECOMING NORTH BEHIND A COLD FRONT LATER TONIGHT AND EARLY MONDAY. THE FRONT IS EXPECTED TO MOVE THROUGH THE DALHART AND GUYMON TAF SITES AROUND 08Z TO 12Z MONDAY...AND THEN ACROSS THE AMARILLO TAF SITE BY 14Z TO 15Z MONDAY. NORTHERLY TO NORTHEASTERLY WINDS WILL INCREASE TO AROUND 15 TO 25 KNOTS WITH HIGHER GUSTS BEHIND THE FRONT AND THEN DIMINISHING TO 10 TO 15 KNOTS AFTER 20Z MONDAY. SCHNEIDER PREV DISCUSSION... /ISSUED 330 PM CDT SUN APR 20 2014/ DISCUSSION... ONLY MINOR CHANGES HAVE BEEN MADE TO THE FORECAST. HAVE INCREASED POPS THIS EVENING ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA... CLOSER TO PROXIMITY OF INCOMING UPPER-LEVEL JET STREAK...IN REGION OF GREATER INSTABILITY. POPS AFTER MIDNIGHT HAVE BEEN TRIMMED TO INCLUDE ONLY FAR EASTERN SECTIONS...AHEAD OF DEPARTING VORTICITY MAXIMUM. MONDAY AND TUESDAY EXPECTED TO BE DRY AND MILD. LOW-LEVEL JET DEVELOPS TUESDAY NIGHT AHEAD OF NEXT MID-LEVEL TROF. WEDNESDAY AFTERNOON CHANCES FOR STRONG TO SEVERE THUNDERSTORMS HAVE BEEN INCREASED SLIGHTLY AND SPREAD A BIT FARTHER WEST DUE TO EXPECTED POSITION OF DRYLINE. WEDNESDAY EVENING POPS HAVE BEEN KEPT IN EASTERN SECTIONS HAVE ALSO BEEN INCREASED SLIGHTLY...AND HAVE ALSO BEEN SPREAD A BIT FARTHER WEST. NO POPS IN REMAINDER OF FORECAST. NO FREEZING TEMPERATURES EXPECTED. 03 COCKRELL FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH TUESDAY. CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE ON WEDNESDAY ACROSS THE WESTERN HALF OF THE PANHANDLES. ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE ON SATURDAY ACROSS THE WESTERN HALF OF THE PANHANDLES. ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ON SUNDAY ACROSS THE WESTERN TWO THIRDS OF THE PANHANDLES. 03 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 11
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1255 PM CDT MON APR 21 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 323 AM CDT MON APR 21 2014 THE MAIN FOCUS THROUGH TONIGHT IS ON THE TIMING OF THE COLD FRONT PASSAGE AND THE CONVECTION THAT IS EXPECTED TO DEVELOP AHEAD OF IT TODAY. SHOWERS AND SOME THUNDERSTORMS CONTINUE ACROSS MUCH OF THE REGION WHICH IS IN A BROAD CHANNEL OF LOW LEVEL MOISTURE TRANSPORT AHEAD OF A SURFACE COLD FRONT. THE 21.07Z RAP ANALYSIS SHOWS THAT THE HIGHEST 0-3KM MUCAPE OF A FEW HUNDRED J/KG IS ACROSS SOUTH CENTRAL MINNESOTA AND NORTH CENTRAL IOWA WHERE DEW POINTS ARE IN THE MID TO UPPER 50S AND TEMPERATURES ARE IN THE LOW 60S. 0-6KM SHEAR IS ALSO WEAK AT 20-30KTS...SO ANY STORMS THAT HAVE DEVELOPED ARE PULSEY AND COLLAPSE RATHER QUICKLY. THE 21.00Z NAM/GFS/GEM/ECMWF AND 21.06Z RAP/HRRR/HOPWRF ARE ALL IN VERY GOOD AGREEMENT WITH THE TIMING OF THE COLD FRONT COMING THROUGH THE REGION TODAY. CURRENTLY...SURFACE OBS SHOW THAT THIS FRONT IS IN WESTERN MINNESOTA/EASTERN NEBRASKA. GUIDANCE SUGGESTS THAT THE FRONT WILL BE INTO NORTHEAST WISCONSIN/FAR SOUTHEAST MINNESOTA/NORTHEAST IOWA AROUND NOON AND THEN CLEAR OF SOUTHWEST WISCONSIN BY MID AFTERNOON. INSTABILITY WILL BUILD AHEAD OF THE FRONT THOUGH THE 21.00Z NAM/GFS AND 21.06Z RAP LIKELY DEVELOP TOO HIGH OF MUCAPE WITH THEM SHOWING SURFACE DEW POINTS CLIMBING UP TO THE LOW 60S WHEN THEY WILL LIKELY BE MORE IN THE MID 50S. THERMAL PROFILES SHOW THAT THIS INSTABILITY IS IN THE 0C TO -20C PORTION OF THE SOUNDINGS...SO THERE COULD BE SOME SMALL HAIL THAT DEVELOPS FROM THIS CONVECTION DESPITE 0-6KM SHEAR REMAINING WEAK AT 20-30KT. ONCE THE FRONT COMES THROUGH...THERE IS A SOLID SLUG OF DRIER AIR THAT WILL MOVE INTO THE REGION. TEMPERATURES MAY NOT MAKE TOO MUCH OF AN INITIAL DROP SINCE THE FRONT IS COMING THROUGH DURING THE MIDDLE OF THE DAY WITH THE DRIER AIR MASS BEHIND THE FRONT ALLOWING FOR QUICKER WARMING UNDER SUNNY SKIES. TEMPERATURES WILL PLUMMET TONIGHT WITH THE DRY AIR MASS IN PLACE AND NORTHWESTERLY LOW LEVEL WINDS KICKING IN. COULD SEE SOME GUSTY WINDS AS WELL WITH THIS DRY AIR IN THE AFTERNOON WITH SOME 35MPH GUSTS POSSIBLE IN THE HIGHER TERRAIN OF SE MN/NE IA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 323 AM CDT MON APR 21 2014 THE MAIN FOCUS IN THE EXTENDED IS ON A BROAD MID LEVEL TROUGH CURRENTLY ALONG THE WEST COAST WHICH WILL PROPAGATE EAST ALONG THE US/CANADIAN BORDER FROM THE MIDDLE TO END PORTION OF THE WEEK. GUIDANCE HAS BEEN IN FAIRLY GOOD AGREEMENT ON THIS SYSTEM THOUGH THERE ARE SOME MINOR DIFFERENCES THAT ARISE TOWARD THE LATER PORTION OF THE SYSTEM. CONFIDENCE IS STILL FAIRLY HIGH THAT PRECIPITATION WILL MOVE IN FROM THE WEST ON WEDNESDAY WITH THE LEAD WARM AIR ADVECTION BAND FOLLOWED BY THE MAIN MOISTURE CHANNEL AHEAD OF THE COLD FRONT ON THURSDAY. THERMAL PROFILES STILL DO NOT SHOW MUCH IN THE WAY OF INSTABILITY BUT DO INCREASE PW VALUES UP TO AROUND 1-1.50" EARLY ON THURSDAY. BASED ON THIS CONSISTENT SIGNAL...HAVE UPPED PRECIPITATION CHANCES INTO THE 70-85 PERCENT RANGE FOR MUCH OF THE REGION WITH TOTAL QPF VALUES EXPECTED TO BE AROUND AN INCH. GUIDANCE STARTS TO DEVIATE QUITE A BIT STARTING FRIDAY WITH THE 21.00Z GFS SHOWING A STRONG RIDGE OF HIGH PRESSURE EXTENDING FROM HUDSON BAY THROUGH THE NORTHERN PLAINS WHILE THE 21.00Z ECMWF IS WEAKER WITH THIS RIDGE AND KEEPS A LOW LEVEL THERMAL GRADIENT ACROSS THE REGION ON INTO THE SOUTHERN GREAT LAKES. THE GFS SOLUTION WOULD BE A COLDER/DRIER ONE FOR US WHILE THE ECMWF SOLUTION WOULD MEAN A WETTER/SLIGHTLY WARMER SOLUTION THAT STILL COULD BRING SOME P-TYPE ISSUES IN WITH IT. CURRENTLY...WPC IS FAVORING THE GFS MORE THAN THE ECMWF BUT TIME WILL TELL. FOR NOW...HAVE DONE A BLEND WITH SOME PRECIPITATION CHANCES IN THERE FOR THE WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1255 PM CDT MON APR 21 2014 A COLD FRONT WILL PUSH EAST OF THE TAF SITES THIS AFTERNOON AS HIGH PRESSURE STARTS TO BUILD IN FROM THE NORTHERN PLAINS. A BKN MVFR STRATUS DECK WILL SCATTER OUT AND EVENTUALLY CLEAR THIS AFTERNOON AS DRIER AIR PUSHES IN FROM THE NORTHWEST. PLAN ON GUSTY NORTHWEST WINDS OF 17 TO 20 KTS THIS AFTERNOON WITH GUSTS IN THE 25 TO 30 KT RANGE. THE WINDS WILL SUBSIDE INTO THE 7 TO 10 KT RANGE LATE THIS EVENING. VFR CONDITIONS ARE EXPECTED FROM LATE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS INTO TUESDAY MORNING. && .HYDROLOGY... ISSUED AT 1255 PM CDT MON APR 21 2014 MINOR FLOODING CONTINUES ON THE MISSISSIPPI RIVER AT MCGREGOR. ALONG THE MISSISSIPPI RIVER...RIVER LEVELS ARE EXPECTED TO GRADUALLY FALL THROUGH MID WEEK BUT THEN WILL LEVEL OFF OR RISE SLIGHTLY AS RUNNOFF FROM SNOWMELT OVER NORTHWEST WISCONSIN AND CENTRAL INTO PORTIONS OF NORTHERN MINNESOTA MAKES ITS WAY INTO THE LOCAL AREA. RIVER LEVELS ARE EXPECTED TO REMAIN ELEVATED INTO NEXT WEEK. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...HALBACH LONG TERM....HALBACH AVIATION...WETENKAMP HYDROLOGY....WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1250 PM CDT MON APR 21 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 323 AM CDT MON APR 21 2014 THE MAIN FOCUS THROUGH TONIGHT IS ON THE TIMING OF THE COLD FRONT PASSAGE AND THE CONVECTION THAT IS EXPECTED TO DEVELOP AHEAD OF IT TODAY. SHOWERS AND SOME THUNDERSTORMS CONTINUE ACROSS MUCH OF THE REGION WHICH IS IN A BROAD CHANNEL OF LOW LEVEL MOISTURE TRANSPORT AHEAD OF A SURFACE COLD FRONT. THE 21.07Z RAP ANALYSIS SHOWS THAT THE HIGHEST 0-3KM MUCAPE OF A FEW HUNDRED J/KG IS ACROSS SOUTH CENTRAL MINNESOTA AND NORTH CENTRAL IOWA WHERE DEW POINTS ARE IN THE MID TO UPPER 50S AND TEMPERATURES ARE IN THE LOW 60S. 0-6KM SHEAR IS ALSO WEAK AT 20-30KTS...SO ANY STORMS THAT HAVE DEVELOPED ARE PULSEY AND COLLAPSE RATHER QUICKLY. THE 21.00Z NAM/GFS/GEM/ECMWF AND 21.06Z RAP/HRRR/HOPWRF ARE ALL IN VERY GOOD AGREEMENT WITH THE TIMING OF THE COLD FRONT COMING THROUGH THE REGION TODAY. CURRENTLY...SURFACE OBS SHOW THAT THIS FRONT IS IN WESTERN MINNESOTA/EASTERN NEBRASKA. GUIDANCE SUGGESTS THAT THE FRONT WILL BE INTO NORTHEAST WISCONSIN/FAR SOUTHEAST MINNESOTA/NORTHEAST IOWA AROUND NOON AND THEN CLEAR OF SOUTHWEST WISCONSIN BY MID AFTERNOON. INSTABILITY WILL BUILD AHEAD OF THE FRONT THOUGH THE 21.00Z NAM/GFS AND 21.06Z RAP LIKELY DEVELOP TOO HIGH OF MUCAPE WITH THEM SHOWING SURFACE DEW POINTS CLIMBING UP TO THE LOW 60S WHEN THEY WILL LIKELY BE MORE IN THE MID 50S. THERMAL PROFILES SHOW THAT THIS INSTABILITY IS IN THE 0C TO -20C PORTION OF THE SOUNDINGS...SO THERE COULD BE SOME SMALL HAIL THAT DEVELOPS FROM THIS CONVECTION DESPITE 0-6KM SHEAR REMAINING WEAK AT 20-30KT. ONCE THE FRONT COMES THROUGH...THERE IS A SOLID SLUG OF DRIER AIR THAT WILL MOVE INTO THE REGION. TEMPERATURES MAY NOT MAKE TOO MUCH OF AN INITIAL DROP SINCE THE FRONT IS COMING THROUGH DURING THE MIDDLE OF THE DAY WITH THE DRIER AIR MASS BEHIND THE FRONT ALLOWING FOR QUICKER WARMING UNDER SUNNY SKIES. TEMPERATURES WILL PLUMMET TONIGHT WITH THE DRY AIR MASS IN PLACE AND NORTHWESTERLY LOW LEVEL WINDS KICKING IN. COULD SEE SOME GUSTY WINDS AS WELL WITH THIS DRY AIR IN THE AFTERNOON WITH SOME 35MPH GUSTS POSSIBLE IN THE HIGHER TERRAIN OF SE MN/NE IA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 323 AM CDT MON APR 21 2014 THE MAIN FOCUS IN THE EXTENDED IS ON A BROAD MID LEVEL TROUGH CURRENTLY ALONG THE WEST COAST WHICH WILL PROPAGATE EAST ALONG THE US/CANADIAN BORDER FROM THE MIDDLE TO END PORTION OF THE WEEK. GUIDANCE HAS BEEN IN FAIRLY GOOD AGREEMENT ON THIS SYSTEM THOUGH THERE ARE SOME MINOR DIFFERENCES THAT ARISE TOWARD THE LATER PORTION OF THE SYSTEM. CONFIDENCE IS STILL FAIRLY HIGH THAT PRECIPITATION WILL MOVE IN FROM THE WEST ON WEDNESDAY WITH THE LEAD WARM AIR ADVECTION BAND FOLLOWED BY THE MAIN MOISTURE CHANNEL AHEAD OF THE COLD FRONT ON THURSDAY. THERMAL PROFILES STILL DO NOT SHOW MUCH IN THE WAY OF INSTABILITY BUT DO INCREASE PW VALUES UP TO AROUND 1-1.50" EARLY ON THURSDAY. BASED ON THIS CONSISTENT SIGNAL...HAVE UPPED PRECIPITATION CHANCES INTO THE 70-85 PERCENT RANGE FOR MUCH OF THE REGION WITH TOTAL QPF VALUES EXPECTED TO BE AROUND AN INCH. GUIDANCE STARTS TO DEVIATE QUITE A BIT STARTING FRIDAY WITH THE 21.00Z GFS SHOWING A STRONG RIDGE OF HIGH PRESSURE EXTENDING FROM HUDSON BAY THROUGH THE NORTHERN PLAINS WHILE THE 21.00Z ECMWF IS WEAKER WITH THIS RIDGE AND KEEPS A LOW LEVEL THERMAL GRADIENT ACROSS THE REGION ON INTO THE SOUTHERN GREAT LAKES. THE GFS SOLUTION WOULD BE A COLDER/DRIER ONE FOR US WHILE THE ECMWF SOLUTION WOULD MEAN A WETTER/SLIGHTLY WARMER SOLUTION THAT STILL COULD BRING SOME P-TYPE ISSUES IN WITH IT. CURRENTLY...WPC IS FAVORING THE GFS MORE THAN THE ECMWF BUT TIME WILL TELL. FOR NOW...HAVE DONE A BLEND WITH SOME PRECIPITATION CHANCES IN THERE FOR THE WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1250 PM CDT MON APR 21 2014 A COLD FRONT WILL PUSH EAST OF THE TAF SITES THIS AFTERNOON AS HIGH PRESSURE STARTS TO BUILD IN FROM THE NORTHERN PLAINS. A BKN MVFR STRATUS DECK WILL SCATTER OUT AND EVENTUALLY CLEAR THIS AFTERNOON AS DRIER AIR PUSHES IN FROM THE NORTHWEST. PLAN ON GUSTY NORTHWEST WINDS OF 17 TO 20 KTS THIS AFTERNOON WITH GUSTS IN THE 25 TO 30 KT RANGE. THE WINDS WILL SUBSIDE INTO THE 7 TO 10 KT RANGE LATE THIS EVENING. VFR CONDITIONS ARE EXPECTED FROM LATE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS INTO TUESDAY MORNING. && .HYDROLOGY... ISSUED AT 1250 PM CDT MON APR 21 2014 MINOR FLOODING CONTINUES ON THE MISSISSIPPI RIVER AT MCGREGOR. ALONG THE MISSISSIPPI RIVER...RIVER LEVELS ARE EXPECTED TO GRADUALLY FALL THROUGH MID WEEK BUT THEN WILL LEVEL OFF OR RISE SLIGHTLY AS RUNNOFF FROM SNOWMELT OVER NORTHWEST WISCONSIN AND CENTRAL INTO PORTIONS OF NORTHERN MINNESOTA MAKES ITS WAY INTO THE LOCAL AREA. RIVER LEVELS ARE EXPECTED TO REMAIN ELEVATED INTO NEXT WEEK. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...HALBACH LONG TERM....HALBACH AVIATION...WETENKAMP HYDROLOGY....HALBACH
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1037 AM CDT MON APR 21 2014 .UPDATE... A NARROW BAND OF RAIN SHOWERS WITH ISOLATED THUNDER HAS DEVELOPED IN SOUTH-CENTRAL WI. THIS IS ASSOCIATED WITH AN UPPER SHORTWAVE APPROACHING FROM THE SW AND SURFACE TROUGH OVER THE STATE. RIGHT ENTRANCE REGION OF UPPER JET OVER SE CANADA ALSO PROVIDING SOME FORCING. HRRR AND RAP MODELS SLIDE THIS BAND TO THE SOUTHEAST THROUGH THE EARLY AFTERNOON BEFORE ANOTHER BROKEN BAND COMES THROUGH IN THE EVENING WITH THE SURFACE COLD FRONT. NAM AND NMM INDICATE MU CAPE 600 TO 1600 J/KG ACROSS THE CWA SO THUNDERSTORMS STILL A POSSIBILITY THROUGH THE DAY. ATMOSPHERE IS VERY MOIST SO HEAVIER RAIN SHOWERS ARE POSSIBLE. 12Z GRB SOUNDING STILL INDICATES PW VALUES 200 PERCENT OF NORMAL AT ABOUT 1 INCH. MODELS SWEEP THE HIGH PW AXIS QUICKLY TO THE SOUTHEAST AND OUT OF THE CWA LATE THIS EVENING. TEMPS STILL ON TRACK FOR LOWER 70S TODAY. DRIER AND COLDER AIR WILL MOVE IN BEHIND THE FRONT ENDING PRECIP CHANCES LATE IN THE EVENING. && .AVIATION/18Z TAFS/... SHOWERS WITH SCATTERED THUNDERSTORMS ARE EXPECTED TODAY. THOUGH THERE IS CURRENTLY SOME ACTIVITY FROM THE WATERTOWN AREA SOUTHWEST THROUGH MUCH OF DANE COUNTY...MANY LOCATIONS WILL LIKELY STAY DRY UNTIL THE AFTERNOON HOURS. SOME LOWER CIGS/VSBYS ARE POSSIBLE WITHIN HEAVIER SHOWERS/STORMS...BUT OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH TUESDAY. RAIN CHANCES WILL WIND DOWN FROM NORTHWEST TO SOUTHEAST LATER AFTERNOON INTO THE EVENING...WITH DRY WEATHER THEN EXPECTED OVERNIGHT AND TUESDAY. && .PREV DISCUSSION... /ISSUED 325 AM CDT MON APR 21 2014/ TODAY AND TONIGHT...FORECAST CONFIDENCE - MEDIUM. FOCUS OF THIS FORECAST ON PRECIP THREAT TODAY. WATER VAPOR PLUME OF DEEPER MID-UPPER LEVEL MOISTURE HAS BEEN SPREADING INTO WISCONSIN OVERNIGHT. COLUMN PRECIPITABLE WATER VALUES WILL INCREASE TO BETWEEN 1 AND 1.25 INCHES TODAY OVER SRN WI...AHEAD OF SHARPENING MID-LEVEL TROUGH. PWAT VALUES AT THIS RANGE FOR MID-APRIL ARE ABOUT 150-200 PERCENT OF NORMAL AND ABOVE THE 75TH PERCENTILE... APPROACHING 2 STANDARD DEVIATIONS AT KGRB. INITIAL SURGE OF MOISTURE HELPING TO TRIGGER SCATTERED -SHRA EARLY THIS MRNG OVER SRN WI WITH MORE -SHRA INCREASING UPSTREAM OVER SOUTHEAST IA INTO WRN IL. WL KEEP SCT OR CHC POPS OVER MOST OF THE AREA THROUGH THE MID-MORNING WITH LIKELY WORDING CONTINUING IN THE FAR WEST CLOSER TO BETTER SYNOPTIC SCALE LIFT. LATER THIS MORNING THROUGH THE AFTN...PHASING OF STRONGER MID-LEVEL SHORT WAVE CURRENTLY IN VICINITY OF ND/MN BORDER INTO SRN CANADA WITH WEAKER WAVE MOVING THROUGH SRN STREAM. LAYER Q-VECTOR CONVERGENCE INCREASES DURING THIS PERIOD BUT VALUES REMAIN LESS THAN 10 UNITS. CONSIDERING THAT RIGHT ENTRANCE REGION OF UPPER JET BRUSHES PORTIONS OF SRN WI LATER TODAY...RATHER SURPRISED Q-VECTOR CONVERGENCE NOT A LITTLE STRONGER. NEVER THE LESS...WITH DEEP COLUMN MOISTURE IN PLACE...THINK SHOWERS AND SCT T WILL BECOME MORE WIDESPREAD LATER THIS MRNG AND AFTN...SO INCREASED POPS TO CATEGORICAL FOR SEVERAL HOURS. MUCAPE INCREASES TO 500 TO 1000 J/KG BUT BULK SHEAR REMAINS LOW. NOT IMPOSSIBLE STRONGER T MAY PRODUCE SMALL HAIL LATER TODAY. ALSO...CORFIDI VECTORS REMAIN BETWEEN 5 TO 15 KNOTS DURING PEAK FORCING. WARM CLOUD DEPTH REMAINS LESS THAN 7K FEET...HOWEVER SOME LOCATIONS MAY RECEIVE SEVERAL BOUTS OF MODERATE SHRA/T THAT MAY RESULT IN ONE HALF INCH TO ONE INCH OF RAINFALL CAUSING LOCALIZED MINOR STREET FLOODING. SHARPENING MID-LEVEL TROUGH EXITS AREA FAIRLY QUICKLY DURING THE LATE AFTN AND EARLY EVENING AS DRIER...COLDER AIR SWEEPS IN. WL CARRY CHANCE POPS IN THE EARLY EVENING IN THE SOUTHEAST FOLLOWED BY CLEARING SKIES. BOUNDARY LAYER MIXING AND INFLUX OF DRIER AIR WILL PREVENT FOG FORMATION. TUESDAY CONFIDENCE...MEDIUM UPPER TROUGH SHIFTS TO THE EAST WITH COLD ADVECTION CONTINUING. LOW LEVEL COLD POOL LINGERS FOR THE DAY WITH 850 TEMPS A DEGREE OR SO EITHER SIDE OF 0C. 925 TEMPS CONSIDERABLY COLDER AT ONLY 4-7C. THIS WILL LIKELY YIELD HIGHS OF ONLY IN THE 50S AT INLAND AREAS OUTSIDE OF THE LAKE INFLUENCE. MANY LAKESHORE LOCATIONS LIKELY TO STAY IN THE 40S. LOW LEVEL RH PROGS AS WELL AS MOS SHOWING A MUCH MORE GLANCING SHOT OF LOW LEVEL RH..MAINLY IN THE FAR EAST EARLY ON. HOWEVER MOS AND BUFKIT ARE REALLY SHOWING A VERY PARCHED LOOK SO LOOKS LIKE PLENTY OF SUNSHINE ON TAP. WEDNESDAY - CONFIDENCE...MEDIUM HIGH PRESSURE RIDGE SHIFTS EAST WITH SE LOW LEVEL FLOW. MID LEVEL RIDGE AXIS APPROACHES. LOW LEVEL WAA STARTS TO INCREASE. HOWEVER 850 JET CORE WELL WEST OF THE AREA THROUGH 18Z WITH DRY AIRMASS STILL IN PLACE. BUFKIT SOUNDINGS REVEAL THE VAST AMOUNT OF LOW LEVEL DRY AIR TO OVERCOME EAST OF THE LLJ AXIS. THE NAM IS MUCH MORE PRONOUNCED IN THIS REGARD ESP IN THE ERN CWA...WITH THE GFS STILL SHOWING DRY AIR THOUGH NOT AS DEEP. MODELS ARE IN SYNC WITH KEEPING PRECIP LARGELY WEST OF CWA THROUGH 18Z...THEN SOME DIVERGENCE OCCURS IN THE AFTERNOON AS THE GEM/NAM ARE SLUGGISH TO EXPAND PRECIP INTO THE EAST...WHICH HAS MERIT GIVEN THE EXTENT OF DRY AIR ON THE PROGGD SOUNDINGS...WHILE THE GFS/ECMWF BRING QPF ALL THE WAY INTO ERN WI. WILL CONTINUE THE IDEA OF HAVING HIGHEST POPS IN THE WEST...IN BETTER PROXIMITY TO LOW LEVEL JET AXIS. WEDNESDAY NIGHT - CONFIDENCE...MEDIUM LLJ RAMPS UP AND TRANSLATES EAST INTO WI. GREATEST MOISTURE INFLUX ASSOCIATED WITH LLJ AND OVERALL PROGGD POSITION OF LLJ DYNAMICS FAVORS PORTIONS OF WRN AND NRN WI FOR THE BETTER/MORE ORGANIZED CONVECTIVE POTENTIAL. THURSDAY AND THURSDAY NIGHT - CONFIDENCE...MEDIUM POTENT SHORTWAVE APPROACHES FROM THE PLAINS WITH BEST DCVA FROM LATE AFTN INTO THE ERLY EVE HOURS. SOME DISAGREEMENT ON POSITIONING OF SFC LOW CENTER WITH THE GFS MORE OF BLEND OF THE SRN ECMWF AND MORE NW GEM SOLUTIONS. CWASP VALUES ARE NOW JUST SHOWING 50S WITH THE BETTER VALUES FURTHER SOUTH OF THE STATE WHICH IS ALSO HIGHLIGHTED BY THE CIPS ANALOG GUIDANCE. BUFKIT SOUNDINGS ARE ALSO NOT SHOWING A VAST AMOUNT OF CAPE TO WORK WITH. SO WHILE A DECENT COVERAGE OF SHRA/TSRA EXPECTED...CONFIDENCE IN ORGANIZED SVR IS RATHER LOW AT THE MOMENT. FRIDAY - CONFIDENCE...MEDIUM COLD FRONT WILL HAVE SHIFTED OFF TO THE EAST BUT LOW PRESSURE SLOW TO DEPART THE REGION. SO EXPECTING A SHOWERY REGIME TO LINGER. SEVERAL SPOKES OF VORTICITY LIKELY TO BE ENHANCING LIFT IN ADDITION TO THE SURFACE/850 TROUGH AXES COMING INTO PLAY. SATURDAY AND SUNDAY - CONFIDENCE...LOW SUBSTANTIAL MODEL DIFFERENCES WITH THE GFS SHOWING A MORE PROLONGED INFLUENCE OF THE ERN UPPER TROUGH. MEANWHILE THE ECMWF IS MORE PROGRESSIVE WITH THAT FEATURE WITH A RENEWED TROUGH MORE AGGRESSIVELY ADVANCING INTO THE PLAINS AND SETTING UP AN ACTIVE BAROCLINIC ZONE EVENT FROM IOWA INTO ILLINOIS WITH SRN WI ON THE NRN FRINGE OF PRECIP. ALLBLEND POPS TO HANDLE THIS FOR NOW WITH RAIN CHANCES IN THE EXTREME SW CWA SATURDAY AND EXPANDING CWA WIDE FOR SUNDAY. AVIATION/12Z TAFS/...MAINLY VFR CONDITIONS EXPECTED FOR BULK OF THIS FORECAST CYCLE. HOWEVER LIKELY TO BE SEVERAL ROUNDS OF PRECIP AFFECTING TAF SITES. BEST CHANCE LATER THIS MRNG THROUGH MID-LATE AFTN WHEN SCT T WILL BE IN THE VICINITY. BRIEF HEAVY RAINFALL MAY ACCOMPANY SHRA/T AS WELL WITH LIKELY MVFR CIGS/VSBYS. PATCHY LIGHT FOG MAY AFFECT KMSN EARLY THIS MRNG AS WELL. MARINE...LIGHT AND VARIABLE WINDS WILL BECOME MORE SOUTH TO SOUTHEAST THIS MORNING AND THEN VEER TO THE SOUTHWEST AHEAD OF APPROACHING COLD FRONT THIS AFTERNOON. COLD FRONT EXPECTED TO SWEEP ACROSS SOUTHWEST LAKE MI LATE AFTN AND EARLY EVE CAUSING WINDS TO CONTINUE VEERING TO THE NORTHWEST. ENOUGH OF A SURGE OF COLD AIR BEHIND FRONT TO CAUSE WIND GUSTS TO 25 KNOTS OVER THE NEARSHORE WATERS AS PRESSURE GRADIENT TIGHTENS. WL POST SMALL CRAFT ADVY FOR TNGT THRU TUE MRNG. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 1 PM CDT TUESDAY FOR LMZ643>646. && $$ UPDATE...SM/DDV TODAY/TONIGHT AND AVIATION/MARINE...MBK TUESDAY THROUGH SUNDAY...COLLAR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
323 AM CDT MON APR 21 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 323 AM CDT MON APR 21 2014 THE MAIN FOCUS THROUGH TONIGHT IS ON THE TIMING OF THE COLD FRONT PASSAGE AND THE CONVECTION THAT IS EXPECTED TO DEVELOP AHEAD OF IT TODAY. SHOWERS AND SOME THUNDERSTORMS CONTINUE ACROSS MUCH OF THE REGION WHICH IS IN A BROAD CHANNEL OF LOW LEVEL MOISTURE TRANSPORT AHEAD OF A SURFACE COLD FRONT. THE 21.07Z RAP ANALYSIS SHOWS THAT THE HIGHEST 0-3KM MUCAPE OF A FEW HUNDRED J/KG IS ACROSS SOUTH CENTRAL MINNESOTA AND NORTH CENTRAL IOWA WHERE DEW POINTS ARE IN THE MID TO UPPER 50S AND TEMPERATURES ARE IN THE LOW 60S. 0-6KM SHEAR IS ALSO WEAK AT 20-30KTS...SO ANY STORMS THAT HAVE DEVELOPED ARE PULSEY AND COLLAPSE RATHER QUICKLY. THE 21.00Z NAM/GFS/GEM/ECMWF AND 21.06Z RAP/HRRR/HOPWRF ARE ALL IN VERY GOOD AGREEMENT WITH THE TIMING OF THE COLD FRONT COMING THROUGH THE REGION TODAY. CURRENTLY...SURFACE OBS SHOW THAT THIS FRONT IS IN WESTERN MINNESOTA/EASTERN NEBRASKA. GUIDANCE SUGGESTS THAT THE FRONT WILL BE INTO NORTHEAST WISCONSIN/FAR SOUTHEAST MINNESOTA/NORTHEAST IOWA AROUND NOON AND THEN CLEAR OF SOUTHWEST WISCONSIN BY MID AFTERNOON. INSTABILITY WILL BUILD AHEAD OF THE FRONT THOUGH THE 21.00Z NAM/GFS AND 21.06Z RAP LIKELY DEVELOP TOO HIGH OF MUCAPE WITH THEM SHOWING SURFACE DEW POINTS CLIMBING UP TO THE LOW 60S WHEN THEY WILL LIKELY BE MORE IN THE MID 50S. THERMAL PROFILES SHOW THAT THIS INSTABILITY IS IN THE 0C TO -20C PORTION OF THE SOUNDINGS...SO THERE COULD BE SOME SMALL HAIL THAT DEVELOPS FROM THIS CONVECTION DESPITE 0-6KM SHEAR REMAINING WEAK AT 20-30KT. ONCE THE FRONT COMES THROUGH...THERE IS A SOLID SLUG OF DRIER AIR THAT WILL MOVE INTO THE REGION. TEMPERATURES MAY NOT MAKE TOO MUCH OF AN INITIAL DROP SINCE THE FRONT IS COMING THROUGH DURING THE MIDDLE OF THE DAY WITH THE DRIER AIR MASS BEHIND THE FRONT ALLOWING FOR QUICKER WARMING UNDER SUNNY SKIES. TEMPERATURES WILL PLUMMET TONIGHT WITH THE DRY AIR MASS IN PLACE AND NORTHWESTERLY LOW LEVEL WINDS KICKING IN. COULD SEE SOME GUSTY WINDS AS WELL WITH THIS DRY AIR IN THE AFTERNOON WITH SOME 35MPH GUSTS POSSIBLE IN THE HIGHER TERRAIN OF SE MN/NE IA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 323 AM CDT MON APR 21 2014 THE MAIN FOCUS IN THE EXTENDED IS ON A BROAD MID LEVEL TROUGH CURRENTLY ALONG THE WEST COAST WHICH WILL PROPAGATE EAST ALONG THE US/CANADIAN BORDER FROM THE MIDDLE TO END PORTION OF THE WEEK. GUIDANCE HAS BEEN IN FAIRLY GOOD AGREEMENT ON THIS SYSTEM THOUGH THERE ARE SOME MINOR DIFFERENCES THAT ARISE TOWARD THE LATER PORTION OF THE SYSTEM. CONFIDENCE IS STILL FAIRLY HIGH THAT PRECIPITATION WILL MOVE IN FROM THE WEST ON WEDNESDAY WITH THE LEAD WARM AIR ADVECTION BAND FOLLOWED BY THE MAIN MOISTURE CHANNEL AHEAD OF THE COLD FRONT ON THURSDAY. THERMAL PROFILES STILL DO NOT SHOW MUCH IN THE WAY OF INSTABILITY BUT DO INCREASE PW VALUES UP TO AROUND 1-1.50" EARLY ON THURSDAY. BASED ON THIS CONSISTENT SIGNAL...HAVE UPPED PRECIPITATION CHANCES INTO THE 70-85 PERCENT RANGE FOR MUCH OF THE REGION WITH TOTAL QPF VALUES EXPECTED TO BE AROUND AN INCH. GUIDANCE STARTS TO DEVIATE QUITE A BIT STARTING FRIDAY WITH THE 21.00Z GFS SHOWING A STRONG RIDGE OF HIGH PRESSURE EXTENDING FROM HUDSON BAY THROUGH THE NORTHERN PLAINS WHILE THE 21.00Z ECMWF IS WEAKER WITH THIS RIDGE AND KEEPS A LOW LEVEL THERMAL GRADIENT ACROSS THE REGION ON INTO THE SOUTHERN GREAT LAKES. THE GFS SOLUTION WOULD BE A COLDER/DRIER ONE FOR US WHILE THE ECMWF SOLUTION WOULD MEAN A WETTER/SLIGHTLY WARMER SOLUTION THAT STILL COULD BRING SOME P-TYPE ISSUES IN WITH IT. CURRENTLY...WPC IS FAVORING THE GFS MORE THAN THE ECMWF BUT TIME WILL TELL. FOR NOW...HAVE DONE A BLEND WITH SOME PRECIPITATION CHANCES IN THERE FOR THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1114 PM CDT SUN APR 20 2014 SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS NORTHERN IOWA...SITUATED JUST NORTH OF A WARM FRONT ALONG US-20...ARE INCHING THEIR WAY NORTHWARD TOWARDS THE TAF SITES. ITS POSSIBLE FOR THESE SHOWERS TO AFFECT THE TAF SITES FROM NOW THROUGH 14-16Z WHEN A COLD FRONT IS SLATED TO MOVE ACROSS. SINCE CONFIDENCE OF THESE SHOWERS HANGING AT EITHER TAF SITE FOR MORE THAN 1 OR 2 HOURS IS LOW... HAVE ONLY WENT WITH A VCSH. ALSO DID NOT INCLUDE THUNDER AS THE AMOUNT OF LIGHTNING HAS DROPPED OFF QUITE A BIT WITH LOSS OF INSTABILITY. THERE HAS BEEN SOME BR AROUND THE TAF SITES...ENOUGH TO KNOCK LSE DOWN TO MVFR. MVFR VISIBILITIES SHOULD BE THE GENERAL RULE UNTIL COLD FRONTAL PASSAGE. PLAN ON CEILINGS TO STAY VFR. AFTER THE COLD FRONT PASSES...DRIER AIR COMES IN ON GUSTY NORTHWEST WINDS TO ENSURE VFR CONDITIONS. THE WINDS COULD GUST UPWARDS OF 25 KT. PLAN ON THE WIND GUSTS TO DIMINISH AROUND 01Z WITH LOSS OF DAYTIME HEATING...BUT A 10-15 KT SUSTAINED WIND LOOKS LIKELY TO PERSIST ASSOCIATED WITH COLD AIR FLOWING IN. && .HYDROLOGY... ISSUED AT 323 AM CDT MON APR 21 2014 ANYWHERE FROM A TENTH OF AN INCH TO AN INCH AND A HALF OF RAIN FELL YESTERDAY ACROSS THE REGION WITH SOME ADDITIONAL RAIN FALLING EARLY THIS MORNING FROM SHOWERS AND THUNDERSTORMS. THIS HAS LEAD TO A SMALL CLIMB IN AREA RIVERS...PARTICULARLY IN NORTHEAST IOWA WHERE SOME OF THE HEAVIEST RAIN HAS FALLEN. RAIN WILL COME TO AN END FROM WEST TO EAST THIS MORNING AND EARLY AFTERNOON AS A COLD FRONT PUSHES THROUGH. ANOTHER SYSTEM WILL COME IN AROUND MID WEEK WHICH COULD DROP A WIDESPREAD AREA OF AN INCH OR MORE OF RAIN FROM WEDNESDAY INTO THURSDAY. THIS WILL LIKELY LEAD TO A SECOND CREST ON MANY AREA RIVERS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...HALBACH LONG TERM...HALBACH AVIATION...AJ HYDROLOGY...HALBACH
AREA FORECAST DISCUSSION
NWS TOPEKA KS
343 AM CDT Wed Apr 23 2014 .SHORT TERM...(Today and Tonight) Issued at 341 AM CDT WED APR 23 2014 08Z water vapor shows a longwave trough moving into the Rockies with a mid level ridge axis over the Great Plains. At the surface, obs shows ridging along the upper and middle MS river valley with a lee trough over WY and CO deepening. Radar shows scattered shower activity gradually expanding in coverage over the past couple hours. The RAP and NAM show isentropic upglide on the 305K surface, which seems to line up with where the elevated showers are developing, persisting into the early afternoon. With the HRRR, RAP and NAM all showing this scattered activity going on through the morning, have increased pops and will include coverage wording in the forecast. Forecast soundings show little if any instability for this activity to work with so would anticipate thunder to remain relatively isolated this morning. Meanwhile the models continue to show some surface based instability developing this afternoon across north central KS ahead of a Pacific cold front. As the upper shortwave moves out across the plains, thunderstorms are expected to develop along this boundary. This activity is expected to quickly evolve into a linear system and move across the forecast area overnight. Initially there may be some hail and damaging wind threat as the line begins moving into north central KS. And there remains a large amount of low level bulk shear progged by the NAM. But the NAM also develops quite a lot of CIN suggesting the line of storms may be driven more by the front and not necessarily persisting on instability ahead of the boundary. So the expectation is that storm intensity will diminish as the storms move into eastern KS. In any case, good forcing from the shortwave and steep mid level lapse rates should be good enough for much of not all of the forecast to see rain overnight and will maintain categorical POPs tonight. Do not plan to change the wind advisory issued earlier. The latest RAP continues to show a strengthening pressure gradient over south central NEB and north central KS that may be strong enough for sustained winds of 30 mph for a brief period. Otherwise the NAM and GFS are more marginal with the pressure gradient and do not produce as strong of winds. For highs today, am a little concerned the scattered precip and cloud cover could hold temps down especially over northeast KS where this is likely to hang on longer into the afternoon. So tweaked temps down a degree or two over northeast zones. Although there may still be enough mixing and insolation across north central KS for highs to reach around 80. With rain and some cold air advection behind the front tonight, trended min temps Thursday morning down towards the MOS consensus of lower 50s in north central KS to the mid and upper 50s across eastern KS. If the front moves through a little quicker, lows in the east are likely to be to warm. .LONG TERM...(Thursday through Tuesday) Issued at 341 AM CDT WED APR 23 2014 Cold front will continue to move southeastward and out of the far southeast corner by mid morning on Thursday as the upper trough axis swings through cwa. Will therefore continue a steady decline in precipitation chances over the eastern cwa through the morning hours and a dry afternoon fcst. Although the day may start out wet and cloudy early...decreasing clouds and backing llvl winds will aid in temperatures rising back into the low to mid 70s for highs. Winds back around to light southwesterly overnight with lows in the 40s before increasing through the day Friday with mostly sunny skies. Have therefore edged high temperatures upwards slightly to around 80 in many areas. Elevated moisture return and weak instability slowly increase late Friday night/early Saturday morning across the southern cwa and have maintained low chances for thunderstorms. A better chance for thunderstorms will exist with the deeper moisture and instability later in the day into early Sunday as the next strong shortwave trough digs into the desert southwest and ejects out into the central high plains. Thunderstorms may remain elevated until an initial capping inversion is overcome for surface based storms to develop. Either way...strong to severe thunderstorms will be possible Saturday into Sunday ahead of an expected dry slot as the system rotates out into the plains and occludes. It will then slow and shift east and southeastward into the MS river valley with a lingering chance for showers in its wake as much cooler air filters into the area from the north for Monday and especially Tuesday. Highs in the 70s on Saturday will lower into the low to mid 60s for Monday...then the 50s for Tuesday. Lows by Wednesday morning could fall into the mid to upper 30s. && .AVIATION...(For the 06Z TAFs through 06Z Wednesday Night) Issued at 1148 PM CDT TUE APR 22 2014 With area of showers making its way through western Kansas and recent new development ahead of it, will keep VCSH nearly as before. Some suggestions of a least light continued activity through much of the day and there are weak returns on upstream, but coverage and impacts look too low for inclusion. More robust convection will likely hold off until after this forecast. && .TOP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY from 10 AM this morning to 6 PM CDT this evening FOR KSZ008-009-020-021-034-035. && $$ SHORT TERM...Wolters LONG TERM...63 AVIATION...65
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
444 AM EDT WED APR 23 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 416 PM EDT TUE APR 22 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE ALONG THE W COAST OF THE CONUS. JUST DOWNSTREAM OF THE TROF...A SHARP RIDGE ALIGNED ALONG THE LEE OF THE ROCKIES IS ALLOWING FOR TROF AMPLIFICATION INTO THE GREAT LAKES...LED BY SHORTWAVE THAT WAS PASSING JUST N OF LAKE SUPERIOR 24HRS AGO. PER 12Z RAOBS AND LATEST RUC ANALYSIS...850MB THERMAL TROF IS CURRENTLY CENTERED OVER CNTRL LAKE SUPERIOR/CNTRL UPPER MI. AS A RESULT...CLOUD COVER HAS BEEN SLOW TO CLEAR THIS AFTN. TRAILING SHORTWAVE THAT IS CURRENTLY DROPPING SE THRU WRN UPPER MI/NRN LAKE MICHIGAN IS ALSO AIDING THE CLOUD COVER AND HAS ALSO GENERATED FLURRIES/-SHSN THIS AFTN. FLURRIES/-SHSN HAVE ENDED ON THE KEWEENAW AND WILL QUICKLY EXIT THE REST OF THE FCST AREA IN THE NEXT 2-3HRS. AS WOULD BE EXPECTED UNDER THE THERMAL TROF AND WITH ABUNDANT CLOUD COVER...TEMPS HAVE STUGGLED TO RISE TODAY. MID AFTN READINGS ARE IN THE 30S ACROSS MUCH OF UPPER MI (LOW 30S AT SOME LOCATIONS) TO THE LOW/MID 40S SCNTRL AND NEAR KIWD. CLEARING IS NOW GETTING UNDERWAY ACROSS LAKE SUPERIOR...ESPECIALLY THE W HALF. SKIES WILL CLEAR ACROSS THE BOARD DURING THE EVENING AS MUCH DRIER AIR CONTINUES TO SPREAD INTO THE AREA FROM THE N AND W...BUT CLOUDS WILL HANG ON LONGEST OVER THE E AS THERE IS STILL AN AXIS OF MOISTURE/CLOUDS EXTENDING BACK TOWARD LAKE NIPIGON. AFTER A CHILLY DAY...CLEAR SKIES WITH WINDS DIMINISHING TO LIGHT/CALM AS SFC HIGH PRES RIDGE AXIS SETTLES OVER WRN UPPER MI DURING THE NIGHT WILL SET THE STAGE FOR A COLD NIGHT. DRY AIR MASS WITH PRECIPITABLE WATER IN THE 40-50PCT RANGE WILL ENHANCE RADIATIONAL COOLING. WILL GO AT OR BLO LOWEST GUIDANCE...ESPECIALLY WHERE MEANINGFUL SNOWCOVER STILL EXITS. TRADIATIONAL COLDS SPOTS WILL LIKELY FALL INTO THE TEENS... BUT 20S WILL GENERALLY BE THE RULE. RECORD LOW FOR NWS MQT FOR APR 23 IS 17F. MIGHT BE CLOSE TO THAT. ON WED...ABUNDANT SUNSHINE TO START THE DAY WILL GIVE WAY TO INCREASING HIGH CLOUDS FROM THE W. WITH SFC HIGH PRES RIDGE JUST DRIFTING E...MESOHIGH WILL SET UP OVER CNTRL AND ERN LAKE SUPERIOR DURING THE AFTN AND ALSO OVER LAKE MICHIGAN. AS A RESULT...LAKE BREEZES WILL DOMINATE...KEEPING LAKESIDE LOCATIONS CHILLY...PROBABLY 30S FOR MUCH OF THE DAY. DRY AIR MASS WILL AID DEEP MIXING POTENTIAL...SO AREAS WELL INLAND FROM THE LAKES WILL BE ABLE TO WARM NICELY AFTER THE COLD START. MIXING TO AROUND 800MB ON FCST SOUNDINGS SUGGESTS MAX TEMPS INTO THE MID 50S ALONG THE WI BORDER. WILL BE WARMER IF MIXING IS HIGHER. MIXING WILL ALSO RESULT IN DWPTS FALLING DURING THE AFTN. UTILIZED SOME OF THE DRYING POTENTIAL BASED ON MIXING HEIGHT TO LOWER DWPTS TO JUST UNDER 20F IN THE INTERIOR. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 441 AM EDT WED APR 23 2014 MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON THE POTENTIAL FOR HEAVY PCPN ON THU INTO EARLY FRI AS WELL AS PTYPE. AT 12Z THU...THE STRONGER NRN SHRTWV WL BE LOCATED NEAR THE CNDN BORDER WITH MONTANA WHILE THE SRN DISTUBANCE SHIFTS E INTO THE CENTRAL PLAINS... WITH ACCOMPANYING SFC LO PRES CENTERS NEARBY. DESPITE THE SEPARATION BTWN THE INDIVIDUAL SHRTWVS...MODEL FCST RH FIELDS SHOW WARM CONVEYOR BELT AREA OF HIER RH EXTENDING FM MN INTO THE UPR LKS UNDER OVERAL SE FLOW TO THE E OF LARGER SCALE LO PRES TROF IN THE PLAINS. H7 SPECIFIC HUMIDITY WITHIN THIS BAND AT THE LATITUDE OF UPR MI IS FCST TO BE ABOUT 4 G/KG...BOOSTED BY H85 S WINDS FCST UP TO 35-50 KTS E OF THE LARGER SCALE TROF AXIS. SO EVEN THOUGH THE MODELS CONTINUE TO SHOW THE SRN SHRTWV WL REMAIN OUT OF PHASE WITH THE NRN DISTURBANCE AND THAT ONLY THE STRONGER NRN SHRTWV WL IMPACT THE CWA AS THESE DISTURBANCES MOVE TO THE E THRU FRI... THERE WL BE ADEQUATE MSTR AVBL FOR POTENTIALLY HEAVY PCPN OVER UPR MI AS THESE INDIVIDUAL DISTURBANCES MOVE INTO THE OHIO RIVER VALLEY AND INTO THE UPR LKS RESPECTIVELY BY 12Z FRI. DIFFLUENT H3 FLOW/SHARP H4-2 DVGC E OF THE ARPCHG NRN SHRTWV WL ALSO ACT TO ENHANCE PCPN RATES OVER THE CWA. THE 00Z GFS/NAM INDICATE THE NRN SHRTWV WL TRACK THRU CENTRAL UPR MI...WITH THE HEAVIEST PCPN MOST LIKELY TO THE N OF THE H85-7-5 LO TRACK FM ABOUT IRONWOOD/ONTONAGON TO MARQUETTE BEFORE THE PCPN SLOWLY DIMNISHES ON FRI WITH THE ARRIVAL OF DNVA/LARGER SCALE QVECTOR DVGC IN THE WAKE OF THE DEPARTING SHRTWV INTO SE ONTARIO. BUT THE 00Z UKMET AND THE 22/12Z AND 23/00Z ECMWF SHOW A FARTHER N TRACK FOR THE NRN SHRTWV AND H85-7 LO ACRS THE NRN KEWEENAW...WITH EARLIER DRY SLOTTING BY 06Z-12Z FRI AND A SHORTER WINDOW FOR HEAVIER PCPN. THE 00Z CNDN MODEL IS A COMPROMISE BTWN THESE TWO CAMPS...BUT SEEMS MORE ALIGNED WITH THE NCEP MODELS. 24 HR PCPN TOTALS THRU 12Z FRI SHOWN BY THE NCEP MODELS RANGE FM 0.65-1.10 INCH...LEAST OVER THE SE AND GREATEST OVER THE KEWEENAW ON THE CYC SIDE OF THE UPR LO FCST TRACK. IN CONTRAST...THE 22/12Z ECWMF SHOWED 24 HR PCPN RANGING FM 0.50 INCH OVER THE SE TO 0.75 INCH OVER THE KEWEENAW. A MAJOR CONCERN THIS LATE IN THE SEASON IS ON PTYPE AND HOW SFC TEMPS WL IMPACT SN ACCUM RATES. MODELS SHOW PCPN ARRIVING W-E ON THU...REACHING NEWBERRY BY LATE IN THE AFTN. SINCE THE PCPN WL BE ARRIVING DURING DAYTIME HEATING...WHEN H100-85 THKNS ARE FCST IN THE 1305-1310M RANGE...SUSPECT THE PCPN WL START AS RA OR A RA/SN MIX OVER THE HIER TERRAIN WITH SOME EVAPORATIVE COOLING IN THE INITALLY DRY LLVL AIR. EVEN WHERE SN IS MIXED IN WITH THE PCPN...EXPECT LTL IF ANY SN ACCUMULATION ON WARMER SFCS LIKE ROADS. LOSS OF DAYTIME HEATING/DYNAMIC COOLING WL ALLOW THE PCPN TO CHG TO PRIMARILY SN BY 00Z FRI AS H100-85 THKNS FALL TO 1295-1305M...ESPECIALLY AT LOCATIONS TO THE N OF THE H85 LO TRACK. IN ADDITION TO THE WARM NEAR SFC TEMPS...A HI AND THIN DGZ WL ALSO REDUCE SN/WATER RATIOS AND MAKE THIS SN PARTICULARLY WET AND HEAVY. BEST BET ATTM IS FOR SN TOTALS TO REACH 6 TO PERHAPS 8 INCHES OVER THE HIER TERRAIN OF THE KEWEENAW GIVEN THE MORE FVRBL LOCATION RELATIVE TO THE H85-7 LO TRACK. OTHER HIER TERRAIN LOCATIONS OVER THE NW HALF OF THE CWA MAY SEE 2 TO 5 INCHES. THE FCST H85-7 LO TRACK ARGUES FOR MAINLY RA AND LTL SN ACCUM OVER THE SE PORTION OF UPR MI. SUSPECT FUTURE SHIFTS WL NEED TO ISSUE WINTER WX ADVYS FOR THE HIER TERRAIN OF NW UPR MI. GIVEN THE GREAT UNCERTAINTY ON SHRTWV LO TRACKS AND THE IMPACT OF TEMPS ON SN ACCUM RATES FOR A MAINLY 4TH PERIOD SN FALL...OPTED TO UPDATE GOING SPECIAL WEATHER STATEMENT. FRI NGT...ANOTHER SHRTWV DIVING ESEWD INTO THE UPR LKS BEHIND DEPARTING SHRTWV MAY BRING SOME LGT SN/RA TO THE CWA. THE 00Z CNDN MODEL IS STRONGEST WITH THIS DISTURBANCE AND GENERATES ANOTERH 0.50 INCH OF PCPN NEAR THE WI BORDER...BUT THIS STRONGER/WETTER SCENARIO SEEMS UNREASONABLE GIVEN THE LARGER SCALE HGT RISES/DRYING THAT WOULD BE EXPECTED OVER UPR MI IN THE WAKE OF THE DEPARTING INITIAL STRONGER NRN SHRTWV. EXTENDED...THE NW FLOW ALF E OF UPR RDG BLDG IN THE PLAINS IN THE WAKE OF THE DEPARTING LO PRES AND TO THE S OF SPRAWLING HI PRES OVER SCENTRAL CANADA ARE FCST TO PUSH DRIER AIR INTO THE UPR LKS STARTING ON SAT. SOME OF THE LONGER RANGE MODELS SHOW NEXT SHRTWV LIFTING NE OUT OF THE PLAINS BRINGING A RETURN OF PCPN AS EARLY AS SUN NGTCONSIDERING THIS HUDSON BAY HI AND THE LIKELY DRY NNE FEED OF DRY AIR THAT WL IMPACT THE AREA/CLIMATOLOGY OF HUDSON BAY HI PRES SYSTEMS IN SPRING...OPTED TO CUT MODEL CONSENSUS POPS AND KEEP THE FCST DRY THRU MON. TEMPS WL AVG BLO NORMAL DURING THIS TIME. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 439 AM EDT WED APR 23 2014 HIGH PRESSURE OVERHEAD THIS MORNING WILL SLOWLY EDGE TO OUR E DURING THE LATE AFTERNOON HOURS...AND EXIT E OF UPPER MI OVERNIGHT. LOOK FOR THIN HIGH CLOUDS TO THICKEN AND LOWER LATE THIS AFTERNOON THROUGH DAYBREAK THURSDAY IN RESPONSE TO THE ELONGATED AREA OF LOW PRESSURE NEARING FROM FROM S CANADA THROUGH THE S PLAINS. COULD HAVE A CHANCE OF SNOW AND A SLIGHT CHANCE OF SNOW AT IWD JUST PRIOR TO 12Z THURSDAY...BEFORE CEILINGS BEGIN TO FALL BELOW VFR. A LOW LEVEL JET NEARING 40KTS AROUND 2KFT WILL ARRIVE AROUND 12Z THURSDAY AT IWD...WHICH MAY NECESSITATE THE INCLUSION OF LLWS AS SFC WINDS REMAIN AROUND 10-15KTS. OTHERWISE...THE STRONGEST WINDS ABOVE THE SFC LOOK TO HOLD OFF AT CMX AND SAW UNTIL MID AFTERNOON THURSDAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 439 AM EDT WED APR 23 2014 HIGH PRESSURE ACROSS THE UPPER GREAT LAKES WILL SHIFT E TO CANADA AND THE LOWER GREAT LAKES ON THURSDAY. THIS WILL MAKE WAY FOR THE LOW STRETCHING FROM SOUTHERN SASKATCHEWAN TO IA AROUND DAYBREAK THURSDAY TO PUSH ACROSS THE UPPER GREAT LAKES THURSDAY NIGHT THROUGH FRIDAY...BEFORE EXITING ACROSS LAKE HURON LATE FRIDAY AFTERNOON. LOOK FOR A MIX OF RAIN AND SNOW OVER THE W HALF OF LAKE SUPERIOR BY MID MORNING THURSDAY...BEFORE EXPANDING ACROSS THE REMAINDER OF THE LAKE BY THE END OF THE DAY. PERIODS OF MODERATE SNOW MAY BE POSSIBLE OVER MAINLY W LAKE SUPERIOR THURSDAY EVENING...AND ACROSS CENTRAL AND E AREAS OVERNIGHT AS E WINDS GUSTS INTO THE 20-30KT RANGE. A FEW GALES MAY STILL BE POSSIBLE...SO STAY TUNED TO LATER FCSTS. LARGE HIGH PRESSURE OVER CENTRAL CANADA ON FRIDAY WILL PUSH ACROSS HUDSON BAY SATURDAY...WHERE IT WILL REMAIN THROUGH SUNDAY. EXPECT A RIDGE EXTENDING SOUTHWARD ACROSS LAKE SUPERIOR FRIDAY NIGHT TO STRENGTHEN OVER THE AREA ON SATURDAY...AND LINGER INTO SUNDAY AS LOW PRESSURE ORGANIZES ACROSS THE CENTRAL PLAINS. INCREASED N-NW GUSTS NEARING 30KTS OR MORE MAY BE POSSIBLE AGAIN FRIDAY AFTERNOON INTO EARLY SATURDAY...STRONGEST OVER CENTRAL AND E LAKE SUPERIOR. && .HYDROLOGY... ISSUED AT 441 AM EDT WED APR 23 2014 THE ARRIVAL OF MUCH COLDER AIR IS LEADING TO GREATLY REDUCED SNOWMELT RUNOFF OVER UPR MI. BUT SINCE RUNOFF FROM RECENT ABOVE NORMAL TEMPS AND SNOWMELT CONTINUES TO FLOW THRU THE GROUND...SOME AREA STREAMS AND RIVERS ARE STILL RISING SLOWLY. LOCATIONS EXPERIENCING RISES NEAR OR ABOVE BANKFULL HAVE BEEN ALSTON AND CHASSELL ON THE STURGEON RIVER...CRYSTAL FALLS ON THE PAINT RIVER...AND HARVEY ON THE CHOCOLAY RIVER. SINCE CHILLY AND DRY WEATHER WILL CONTINUE THRU TONIGHT...SNOWMELT AND RUNOFF SHOULD DIMINISH AND PREVENT THESE RIVERS FROM EXCEEDING FLOOD STAGE IN THE SHORT TERM. REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE SIGNIFICANT ICE REMAINS. UNSETTLED WEATHER WILL RETURN THURSDAY AND THURSDAY NIGHT AS ANOTHER LOW PRESSURE SYSTEM MOVES FROM THE PLAINS TOWARD THE GREAT LAKES... POTENTIALLY ADDING TO RUNOFF LATER THIS WEEK. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY FRIDAY MORNING. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW PENINSULA. IF MORE OF THE PRECIPITATION FALLS AS SNOW...RUNOFF WILL BE DELAYED UNTIL WARMER WEATHER RETURNS NEXT WEEK. OVERALL...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS OVER THE NEXT WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KC AVIATION...KF MARINE...KF HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
440 AM EDT WED APR 23 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 416 PM EDT TUE APR 22 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE ALONG THE W COAST OF THE CONUS. JUST DOWNSTREAM OF THE TROF...A SHARP RIDGE ALIGNED ALONG THE LEE OF THE ROCKIES IS ALLOWING FOR TROF AMPLIFICATION INTO THE GREAT LAKES...LED BY SHORTWAVE THAT WAS PASSING JUST N OF LAKE SUPERIOR 24HRS AGO. PER 12Z RAOBS AND LATEST RUC ANALYSIS...850MB THERMAL TROF IS CURRENTLY CENTERED OVER CNTRL LAKE SUPERIOR/CNTRL UPPER MI. AS A RESULT...CLOUD COVER HAS BEEN SLOW TO CLEAR THIS AFTN. TRAILING SHORTWAVE THAT IS CURRENTLY DROPPING SE THRU WRN UPPER MI/NRN LAKE MICHIGAN IS ALSO AIDING THE CLOUD COVER AND HAS ALSO GENERATED FLURRIES/-SHSN THIS AFTN. FLURRIES/-SHSN HAVE ENDED ON THE KEWEENAW AND WILL QUICKLY EXIT THE REST OF THE FCST AREA IN THE NEXT 2-3HRS. AS WOULD BE EXPECTED UNDER THE THERMAL TROF AND WITH ABUNDANT CLOUD COVER...TEMPS HAVE STUGGLED TO RISE TODAY. MID AFTN READINGS ARE IN THE 30S ACROSS MUCH OF UPPER MI (LOW 30S AT SOME LOCATIONS) TO THE LOW/MID 40S SCNTRL AND NEAR KIWD. CLEARING IS NOW GETTING UNDERWAY ACROSS LAKE SUPERIOR...ESPECIALLY THE W HALF. SKIES WILL CLEAR ACROSS THE BOARD DURING THE EVENING AS MUCH DRIER AIR CONTINUES TO SPREAD INTO THE AREA FROM THE N AND W...BUT CLOUDS WILL HANG ON LONGEST OVER THE E AS THERE IS STILL AN AXIS OF MOISTURE/CLOUDS EXTENDING BACK TOWARD LAKE NIPIGON. AFTER A CHILLY DAY...CLEAR SKIES WITH WINDS DIMINISHING TO LIGHT/CALM AS SFC HIGH PRES RIDGE AXIS SETTLES OVER WRN UPPER MI DURING THE NIGHT WILL SET THE STAGE FOR A COLD NIGHT. DRY AIR MASS WITH PRECIPITABLE WATER IN THE 40-50PCT RANGE WILL ENHANCE RADIATIONAL COOLING. WILL GO AT OR BLO LOWEST GUIDANCE...ESPECIALLY WHERE MEANINGFUL SNOWCOVER STILL EXITS. TRADIATIONAL COLDS SPOTS WILL LIKELY FALL INTO THE TEENS... BUT 20S WILL GENERALLY BE THE RULE. RECORD LOW FOR NWS MQT FOR APR 23 IS 17F. MIGHT BE CLOSE TO THAT. ON WED...ABUNDANT SUNSHINE TO START THE DAY WILL GIVE WAY TO INCREASING HIGH CLOUDS FROM THE W. WITH SFC HIGH PRES RIDGE JUST DRIFTING E...MESOHIGH WILL SET UP OVER CNTRL AND ERN LAKE SUPERIOR DURING THE AFTN AND ALSO OVER LAKE MICHIGAN. AS A RESULT...LAKE BREEZES WILL DOMINATE...KEEPING LAKESIDE LOCATIONS CHILLY...PROBABLY 30S FOR MUCH OF THE DAY. DRY AIR MASS WILL AID DEEP MIXING POTENTIAL...SO AREAS WELL INLAND FROM THE LAKES WILL BE ABLE TO WARM NICELY AFTER THE COLD START. MIXING TO AROUND 800MB ON FCST SOUNDINGS SUGGESTS MAX TEMPS INTO THE MID 50S ALONG THE WI BORDER. WILL BE WARMER IF MIXING IS HIGHER. MIXING WILL ALSO RESULT IN DWPTS FALLING DURING THE AFTN. UTILIZED SOME OF THE DRYING POTENTIAL BASED ON MIXING HEIGHT TO LOWER DWPTS TO JUST UNDER 20F IN THE INTERIOR. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 447 PM EDT TUE APR 22 2014 THE BULK OF THE LONG TERM FORECAST DEALS WITH AN UPPER LEVEL TROUGH AND ASSOCIATED LOW PRESSURE SYSTEM THAT MOVES THROUGH THE GREAT LAKES REGION LATE WEDNESDAY NIGHT AND LIKELY CONTINUING INTO FRIDAY EVENING. THE UPPER TROUGH MOVING OVER THE WESTERN COAST OF THE PACIFIC NORTHWEST WILL BE THE FEATURE TO INFLUENCE THE AREA FOR THE END OF THIS WEEK. AS THIS SYSTEM CROSSES THE ROCKIES...A SURFACE LOW WILL DEVELOP IN THE LEE OF THE CANADIAN/NORTHERN ROCKIES AND SHIFT EAST INTO THE UPPER MISSISSIPPI VALLEY ON THURSDAY. HIGH PRESSURE THAT WILL BE OVER THE AREA TONIGHT AND WEDNESDAY WILL BE SLOWLY DEPARTING THE AREA WEDNESDAY NIGHT. THIS...COMBINED WITH A SLIGHTLY LATER ARRIVAL FROM THE UPPER TROUGH...WILL DELAY THE START OF THE PRECIPITATION LATER THAN EXPECTED 24 HOURS AGO AND GENERALLY MOVING IN DURING THE DAY ON THURSDAY. THERE ARE SEVERAL WAVES ASSOCIATED WITH THIS UPPER TROUGH...WHICH LEADS TO A DOUBLE BARREL LOW MOVING OUT OF THE NORTHERN/CENTRAL PLAINS ON WEDNESDAY NIGHT. WHILE PREVIOUS MODELS RUNS HAD THE IDEA OF THESE LOWS MERGING WHEN THE NORTHERN/SOUTHERN WAVES IN THE UPPER TROUGH COMING TOGETHER AND STRENGTHENING AS IT MOVES THROUGH NORTHERN LAKE MICHIGAN. BUT MOST OF THE 12Z MODEL RUNS (EXCEPT FOR THE GFS) HAS TRENDED TOWARDS THE LACK OF PHASING BETWEEN THOSE UPPER LEVEL WAVES. WITHOUT THIS PHASING...THE SOUTHERN STREAM WAVE WOULD SHIFT EAST THROUGH THE CENTRAL MISSISSIPPI VALLEY THURSDAY NIGHT AND JUST HAVE A BROAD LOW MOVING THROUGH THE AREA. WHILE THIS STILL BRING PRECIPITATION TO THE AREA...IT MAY HAVE SOME AFFECT ON THE AMOUNTS OVER PORTIONS OF THE AREA BEFORE THE NORTHERN STREAM WAVE ARRIVES THURSDAY NIGHT OVER THE UPPER GREAT LAKES. THE GREATEST AFFECT OF THIS SPLIT FEATURE IS FOR THE PRECIPITATION TO STEADILY SHIFT NORTHEAST AND GENERALLY OUT OF THE AREA FOR FRIDAY. IF THIS IS THE CASE...FLOW ALOFT WILL BE MORE WESTERLY ON FRIDAY...LEADING TO WARMER TEMPERATURES AND DRIER CONDITIONS THAN INITIALLY EXPECTED. ALTHOUGH THERE ARE STILL DIFFERENCES IN THE MODELS WITH THE EXACT HANDLING OF THE PHASING...IT STILL APPEARS THE MOST OF THE CWA WILL SEE 0.5 INCH OF QPF. THE HEAVIEST PRECIPITATION STILL APPEARS TO OCCUR OVER THE WESTERN HALF TO 2/3RDS OF THE U.P. AND EXPECT SOME LOCATIONS OVER THE WEST TO BE NEARING 1 INCH OF LIQUID EQUIVALENT. THE IMPACT FROM THIS EVENT AND THE ASSOCIATED 0.75-1.0 INCH OF QPF OVER THE WESTERN HALF OF THE CWA WILL DEPEND ON THE PRECIP TYPE FORECAST. ALTHOUGH THIS FORECAST HAS BEEN AND CONTINUES TO BE TRICKY...TRENDS IN THE MODELS ARE POINTING TOWARDS SNOW OVER AT LEAST THE NORTHWEST HALF OF UPPER MICHIGAN WITH THE WARMER AIR REMAINING HUNG UP TO THE SOUTH-SOUTHEAST OF THE AREA. IN ADDITION...WITH THE DRY AIR FROM THE HIGH TAKING LONGER TO DEPART...THE LOW LEVEL DRY AIR WILL AID EVAPORATIVE COOLING IN THE LOW LEVELS AS THE PRECIPITATION STARTS. THIS WOULD LEAD TO ABOVE FREEZING LAYERS ABOVE THE SURFACE TO COOL TO OR BELOW FREEZING AND HAVE A FEELING THE PRECIP TYPE WILL BE LARGELY SNOW INITIALLY OVER THE WEST (ESPECIALLY HIGHER TERRAIN). THE 12Z MODEL THERMAL FIELDS ARE STILL BORDERLINE FOR PRECIP TYPE HEADING THROUGH THURSDAY...BUT LOOKING AT SOUNDINGS THERE IS A NEARLY ISOTHERMAL LAYER BELOW 750MB AROUND OR BELOW FREEZING. THUS...HAVE TRENDED THE FORECAST TOWARDS A MORE SNOW THAN RAIN OVER THE NORTHWEST HALF. AT THIS TIME...THAT BEST OPPORTUNITY FOR A RAIN/SNOW MIX OR MORE RAIN WOULD BE ALONG THE WISCONSIN BORDER AND ALSO SOUTHEAST OF A LINE FROM IRON MOUNTAIN TO GWINN TO SENEY. ALTHOUGH THERE ARE SOME INDICATIONS IN THE COBB OUTPUT OF HIGHER SNOW RATIOS...WOULD EXPECT VALUES TO BE GENERALLY IN THE 8-10 TO 1 RANGE DUE TO THE AMOUNT OF FORCING BELOW THE DGZ. SINCE THE SNOW WILL START DURING THE DAY THURSDAY...IT IS DIFFICULT TO GET SIGNIFICANT ACCUMULATIONS TO OCCUR BEFORE DAYTIME HEATING IS LOST (ESPECIALLY ON ROADWAYS) AND HAVE LIMITED AMOUNTS DURING THE DAY TO A SLUSHY COUPLE INCHES OVER PORTIONS OF THE WEST. WITH THE COOLING AT NIGHT...SHOULD SEE ACCUMULATIONS INCREASE ON BOTH ROADS AND SNOW/GRASS COVERED SURFACES. AT THAT TIME...THE BEST QPF AND COLD AIR WILL BE OVER LAKE SUPERIOR AND AFFECTING THE KEWEENAW PENINSULA. HAVE THE HIGHEST AMOUNTS FORECASTED FOR THE KEWEENAW...WITH 6-9 INCHES BY 12Z FRIDAY. SOUTH AND EAST OF THERE ARE MORE UP IN THE AIR WITH THE RAIN POTENTIAL AND SLIGHTLY WARMER SURFACE TEMPERATURES...BUT STILL FEEL THERE COULD BE 2-6 INCHES OF SLUSHY ACCUMULATION. LOOKING AT THE 00Z ECMWF ENSEMBLE SNOWFALL...MORE THAN 50 PERCENT OF THE MEMBERS HAVE 24HR SNOWFALL AMOUNTS OF EXCEEDING 3 INCHES OVER THE NORTHWEST 2/3RDS OF THE CWA AND PROBS DECREASE TO 20-30 PERCENT OF 6 INCHES. WITH LOW CONFIDENCE ON WARNING AMOUNTS AT THIS POINT (AND THE IMPACTS ARE LARGELY IN THE 5TH PERIOD)...DIDN/T FEEL COMFORTABLE WITH ISSUING A WATCH AT THIS PERIOD. THEREFORE...HAVE ISSUED AN SPS FOR PORTIONS OF WESTERN UPPER MICHIGAN AND WILL ALLOW THE SHIFT TONIGHT TO SEE IF THE TRENDS FROM THE 12Z RUNS CONTINUE. BEHIND THE SYSTEM...MODELS ARE FAIRLY CONSISTENT ON A STRONG CANADIAN HIGH DEVELOPING IN THE PRAIRIES AND SHIFTING EAST TO HUDSON BAY EARLY NEXT WEEK. THAT WILL LEAD TO DRY NORTH-NORTHEASTERLY FLOW OVER THE AREA INTO THE FIRST HALF OF NEXT WEEK. THAT FLOW REGIME SHOULD KEEP TEMPERATURES BELOW NORMAL (POTENTIALLY NEARING RECORD LOW HIGH TEMPS AT OUR OFFICE) AND ANY PRECIP ASSOCIATED WITH THE UPPER TROUGH MOVING THROUGH THE CENTRAL/SOUTHERN PLAINS SOUTH OF THE AREA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 439 AM EDT WED APR 23 2014 HIGH PRESSURE OVERHEAD THIS MORNING WILL SLOWLY EDGE TO OUR E DURING THE LATE AFTERNOON HOURS...AND EXIT E OF UPPER MI OVERNIGHT. LOOK FOR THIN HIGH CLOUDS TO THICKEN AND LOWER LATE THIS AFTERNOON THROUGH DAYBREAK THURSDAY IN RESPONSE TO THE ELONGATED AREA OF LOW PRESSURE NEARING FROM FROM S CANADA THROUGH THE S PLAINS. COULD HAVE A CHANCE OF SNOW AND A SLIGHT CHANCE OF SNOW AT IWD JUST PRIOR TO 12Z THURSDAY...BEFORE CEILINGS BEGIN TO FALL BELOW VFR. A LOW LEVEL JET NEARING 40KTS AROUND 2KFT WILL ARRIVE AROUND 12Z THURSDAY AT IWD...WHICH MAY NECESSITATE THE INCLUSION OF LLWS AS SFC WINDS REMAIN AROUND 10-15KTS. OTHERWISE...THE STRONGEST WINDS ABOVE THE SFC LOOK TO HOLD OFF AT CMX AND SAW UNTIL MID AFTERNOON THURSDAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 439 AM EDT WED APR 23 2014 HIGH PRESSURE ACROSS THE UPPER GREAT LAKES WILL SHIFT E TO CANADA AND THE LOWER GREAT LAKES ON THURSDAY. THIS WILL MAKE WAY FOR THE LOW STRETCHING FROM SOUTHERN SASKATCHEWAN TO IA AROUND DAYBREAK THURSDAY TO PUSH ACROSS THE UPPER GREAT LAKES THURSDAY NIGHT THROUGH FRIDAY...BEFORE EXITING ACROSS LAKE HURON LATE FRIDAY AFTERNOON. LOOK FOR A MIX OF RAIN AND SNOW OVER THE W HALF OF LAKE SUPERIOR BY MID MORNING THURSDAY...BEFORE EXPANDING ACROSS THE REMAINDER OF THE LAKE BY THE END OF THE DAY. PERIODS OF MODERATE SNOW MAY BE POSSIBLE OVER MAINLY W LAKE SUPERIOR THURSDAY EVENING...AND ACROSS CENTRAL AND E AREAS OVERNIGHT AS E WINDS GUSTS INTO THE 20-30KT RANGE. A FEW GALES MAY STILL BE POSSIBLE...SO STAY TUNED TO LATER FCSTS. LARGE HIGH PRESSURE OVER CENTRAL CANADA ON FRIDAY WILL PUSH ACROSS HUDSON BAY SATURDAY...WHERE IT WILL REMAIN THROUGH SUNDAY. EXPECT A RIDGE EXTENDING SOUTHWARD ACROSS LAKE SUPERIOR FRIDAY NIGHT TO STRENGTHEN OVER THE AREA ON SATURDAY...AND LINGER INTO SUNDAY AS LOW PRESSURE ORGANIZES ACROSS THE CENTRAL PLAINS. INCREASED N-NW GUSTS NEARING 30KTS OR MORE MAY BE POSSIBLE AGAIN FRIDAY AFTERNOON INTO EARLY SATURDAY...STRONGEST OVER CENTRAL AND E LAKE SUPERIOR. && .HYDROLOGY... ISSUED AT 458 PM EDT TUE APR 22 2014 A MUCH COLDER DAY SEEN ACROSS UPPER MICHIGAN TODAY WHEN COMPARED TO YESTERDAY. THIS HAS LED TO REDUCED SNOWMELT WHICH WILL CONTINUE INTO WEDNESDAY...ALTHOUGH SOME RIVER LEVELS WILL LIKELY STILL BE ON THE RISE AS WATER WORKS THROUGH THE RIVER SYSTEMS. ALTHOUGH RATHER COOL TEMPERATURES WILL REMAIN...UNSETTLED WEATHER WILL RETURN THURSDAY AND THURSDAY NIGHT...POTENTIALLY ADDING TO THE RUNOFF. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.50-1.00 INCH OF LIQUID WILL BE POSSIBLE BY FRIDAY MORNING. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW PENINSULA. WE WILL CONTINUE TO REFINE THE FCST AS THE TIME NEARS. SO FAR THE LOCATIONS EXPERIENCING RISES NEAR OR ABOVE BANKFULL HAVE BEEN ALSTON/ALSM4/ AND CHASSELL/CLLM4/ ON THE STURGEON RIVER AND CRYSTAL FALLS/CRYM4/ ON THE PAINT RIVER. SINCE SNOW MELT THE NEXT FEW DAYS WILL BE DIMINISHING...EXPECT THE RIVERS TO SLOWLY SUBSIDE AND NOT EXCEED FLOOD STAGE. OTHERWISE...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS OVER THE NEXT WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...KF MARINE...KF HYDROLOGY...SRF
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1222 AM CDT WED APR 23 2014 .UPDATE...FOR 06Z AVIATION DISCUSSION BELOW && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 325 PM CDT TUE APR 22 2014 HIGH PRESSURE OVER THE NORTHLAND WILL BEGIN TO SHIFT TO THE EAST TONIGHT. CLEAR SKIES AND LIGHT WINDS ARE EXPECTED FOR AT LEAST TONIGHT, AND FOR ALL OF THE NIGHT ACROSS THE EASTERN FORECAST AREA. AS FOR THE WESTERN FORECAST AREA, THERE WILL BE INCREASING HIGH CLOUDS FROM THE WEST AS A LOW PRESSURE SYSTEM DEVELOPS IN THE NORTHERN HIGH PLAINS. THE CLEAR SKIES AND LIGHT WINDS WILL PROMOTE RADIATIONAL COOLING. LOW TEMPERATURES SHOULD RANGE FROM THE MID TO UPPER 20S IN THE EASTERN FORECAST AREA TO THE LOW TO MID 30S ACROSS THE WESTERN FORECAST AREA. THERE IS THE POSSIBILITY OF FOG TONIGHT...HOWEVER I AM NOT CONFIDENT AT THIS POINT. THE LOCAL WRF...NAM...AND RAP MODELS ARE SUGGESTING IT IS POSSIBLE ACROSS THE EASTERN FORECAST AREA...ESPECIALLY CLOSER TO LAKE SUPERIOR. THIS IS SOMETHING THE EVENING SHIFT CAN LOOK MORE INTO WHEN MORE HIGH RESOLUTION MODEL DATA IS AVAILABLE. WEDNESDAY...A DEEP MID/UPPER LEVEL LOW WILL MOVE EAST FROM THE PACIFIC NW TO NORTHERN MONTANA. SURFACE LOW PRESSURE WILL CONTINUE TO DEVELOP AND ORGANIZE IN THE PLAINS...AND BEGIN TO BRING INCREASING SE FLOW AND MOISTURE TO THE UPPER MIDWEST. THE LOW LEVEL SE FLOW WILL BEGIN FAIRLY DRY...SO IT WILL LIKELY TAKE SOME TIME FOR THE LOW LEVELS TO SATURATE BEFORE THE NORTHLAND SEES ANY SIGNIFICANT RAINFALL. THE GFS IS FASTER THAN OTHER MODELS AT BRINGING IN THE PCPN INTO THE FORECAST AREA...SO I LEANED MORE ON THE SREF/NAM/GEM/ECMWF. THE INCREASING CLOUD COVER WILL RESULT IN COOLER TEMPERATURES FOR MUCH OF THE NORTHLAND COMPARED TO TODAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 325 PM CDT TUE APR 22 2014 THE BIG CONCERN FOR THE LONG TERM IS THE MAJOR STORM SYSTEM THAT IS EXPECTED TO MOVE THROUGH THE REGION LATE IN THE WEEK. THERE ARE SOME DISTINCT MODEL DIFFERENCES DURING THIS TIME PERIOD...AS THE MODELS ATTEMPT TO PHASE TWO LOW PRESSURE SYSTEMS INTO ONE MAIN LOW OVER THE WESTERN GREAT LAKES. THE UK/EC AND EVEN THE NAM GENERALLY MAINTAIN TWO DISCRETE LOW AREAS...WITH THE GFS AND GEM COMPLETELY PHASING THE DUAL LOW ENERGY INTO ONE LOW. THE IMPACT ON SENSIBLE WEATHER IS NOT SO DRAMATIC...AS ALL OF THE MODELS SUPPORT FAIRLY HIGH TOTAL QPF. BUT THERE ARE DIFFERENCES IN THE THERMAL PROFILES AND OF COURSE IN WINDS. OVERALL...WILL BE A LITTLE CAREFUL ABOUT COMPLETELY PHASING THE TWO SURFACE LOWS...AND FAVORING A SOLUTION A BIT MORE IN LINE WITH THE ECMWF. OF PERHAPS THE MOST CONCERN FOR OUR AREA IS THE CHANCE OF ACCUMULATING SNOWFALL. MODEL RUN SNOW ACCUMULATION VALUES ARE FAIRLY HIGH FOR NORTHEASTERN MN...ESPECIALLY OVER THE TIP OF THE ARROWHEAD...WHERE ALL OF THE MODELS BASICALLY SUPPORT THE POTENTIAL FOR MORE THAN 6 INCHES OF SNOW. AFTER COORDINATING WITH HPC AND THE WINTER WEATHER DESK...THINK THERE IS TIME TO HOLD OFF ON ISSUING A WATCH FOR THE ARROWHEAD DUE TO DIFFERENCES IN THERMAL PROFILES OF FORECAST SOUNDINGS...DIFFERENCES IN HOW THE MODELS ARE HANDLING THE PHASING OF THE TWO LOW STRUCTURE AND QUESTIONS ABOUT THE POTENTIAL FOR SIGNIFICANT MELTING. SPRING SYSTEMS LIKE THIS ARE NOTORIOUSLY DIFFICULT THIS FAR OUT...AS SUBTLE CHANGES IN THE THERMAL PROFILES COULD YIELD DRAMATICALLY DIFFERENT OUTCOMES. AT THIS POINT...NOT COMFORTABLE ISSUING A WATCH FOR THE ARROWHEAD...BUT IT IS SOMETHING WE WILL NEED TO WATCH VERY CLOSELY AND MAY EVENTUALLY NEED A WATCH. FURTHER SOUTH...SOUTH OF THE IRON RANGE...THERE IS ALSO THE POTENTIAL FOR SOME SNOW ACCUMULATION...BUT IT SHOULD GENERALLY BE A SLUSH ACCUMULATION OF MAYBE UP TO A COUPLE INCHES. EVEN FURTHER SOUTH FROM EAST CENTRAL MINNESOTA INTO OUR SOUTHERN TIER OF COUNTIES...THERE SHOULD BE LITTLE TO NO SNOW ACCUMULATION. NO MATTER WHAT...IT WILL BE A WET AND POTENTIALLY SNOWY END TO THE WEEK FOR THE CWA. IT SHOULD THEN BE QUIET AND MAINLY DRY FOR THE WEEKEND. WILL ALSO NEED TO WATCH THE SYSTEM FOR LATE IN THE WEEKEND...AND EARLY NEXT WORK WEEK...BUT FOR NOW IT LOOKS LIKE IT MAY NOT TOTALLY GET ITS ACT TOGETHER TO HAVE A MAJOR IMPACT ON OUR WEATHER. THAT MAY CHANGE AS IT IS QUITE A WAYS OUT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1218 AM CDT WED APR 23 2014 EXPECT HIGH CLOUDS TO INCREASE TONIGHT INTO WEDNESDAY MORNING...WITH CEILINGS LOWERING THROUGH THE REST OF THE PERIOD. AN AREA OF LOW PRESSURE WILL IMPACT THE REGION AND SPREAD AN AREA OF RAIN FROM SOUTHWEST TO NORTHEAST THROUGH THE REGION WEDNESDAY INTO WEDNESDAY NIGHT. AT THIS TIME...WE JUST HAVE RAIN IN THE TAFS...BUT THERE ARE INDICATIONS NORTHERN TAF SITES COULD SEE A MIX. WE THINK THE MIX WILL OCCUR MAINLY AFTER 06Z THOUGH. CEILINGS/VSBYS WILL LOWER TO MVFR OR EVEN IFR LATE IN THE PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DLH 34 43 32 43 / 80 90 60 40 INL 36 45 32 42 / 80 90 70 40 BRD 41 52 35 49 / 90 70 40 30 HYR 38 50 35 49 / 90 90 50 40 ASX 36 47 34 44 / 80 90 70 50 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...GROCHOCINSKI LONG TERM...DAP AVIATION...MELDE/CANNON
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
344 AM CDT Wed Apr 23 2014 .SHORT TERM: (Today through Friday) Issued at 342 AM CDT Wed Apr 23 2014 Surface ridge extending from Wisconsin south/southwest into the Mid-Mississippi Valley and back into east Texas will move east today ahead of developing low pressure over the Great Plains. Increasing southerly low level flow will result. All short-range model guidance develops an area of warm advection showers over the eastern Plains and pushes it east northeast into northwest Missouri and Iowa today. Looks possible that the southeast edge of the showers could clip our area, but low level air is pretty dry according to the NAM, GFS, and RUC and the primary thrust of moisture return will be back over western Missouri so have only introduced slight chance PoPs over our northwest counties. We should see highs pretty close to what occurred yesterday even with the warm advection since we`ll be starting out the day cooler than Tuesday morning. The exception will be central Missouri where morning lows should be a bit warmer than areas further east. The shortwave currently digging across the Rockies will move out into the Great Plains tonight and the resulting cold front will move into northwest Missouri around 12Z. Still looks like showers and thunderstorms will be ongoing along and ahead of the front as it moves through the CWFA on Thursday. Diurnal heating will likely be limited due to cloud cover and advancing precip from the west, so instability still looks relatively weak. While there should be enough CAPE for thunderstorms, widespread severe weather does not look likely at this time. Stuck closer to the warmer MAV guidance for highs since morning lows will be around 50 across the area and 15-20 degrees of rise should be attainable in warm advection this time of year regardless of cloud cover. Guidance is in good agreement with pushing the front through the entire area shortly after 00Z. Still have some lingering precip east of the Mississippi River Thursday evening as the front exits, but dry after midnight. Pacific high builds across the region Friday morning. As opposed to a colder Canadian airmass, the Pacific ridge should produce temperatures near or slightly above normal in the upper 40s to low 50s Friday morning. West-southwest flow develops Friday morning as the high scoots quickly into the Tennessee Valley so expect temperatures to rebound into the mid and upper 70s. Carney .LONG TERM: (Saturday through Tuesday) Issued at 342 AM CDT Wed Apr 23 2014 While the medium range guidance is coming into better agreement on the overall synoptic pattern, the smaller scale is still unclear. Generally, a secondary cold front will dip south across the Upper Midwest driven south by the last vestiges of Thursday`s shortwave. The front will stall somewhere across the Midwest on Saturday, though models can`t make up their minds where. GFS stalls the front across south/southwest Missouri Saturday morning, while the ECMWF stalls it out over northern Iowa. The GEM is right about in the middle stalling the front over northern Missouri. All three models have some low level baroclinicity over our area, whether it is the primary baroclinic zone associated with the front (GFS/GEM) or a secondary baroclinic zone left over from the Pacific airmass which will be exiting to the east (EC). Warm advection begins Saturday morning with a 30+ kt low level jet pointed at this baroclinic zone and all three models print out some light precip. Have therefore kept chance pops going in central Missouri, and would not be surprised if subsequent shifts need to bump up pops a bit more across the area if model trends become more consistent. The front remains stalled somewhere between Springfield Missouri and Davenport Iowa depending on which model you believe through Monday as the longwave trof over the Pacific moves inland, and becomes negatively tilted over the Rockies and Great Plains. A strong surface low develops as a result and it moves into the Mississippi Valley Monday night into Tuesday. The upper trof cuts off and becomes stagnant while the surface low tracks across Missouri into the Ohio Valley Tuesday. Pattern is more reminiscent of late Fall or Winter than mid to late Spring. Unsure how likely this is to happen, but this is at least the second run in a row that I`ve seen do this. Will have to wait and see, but right now it looks like a cold/wet end to April. Carney && .AVIATION: (For the 06z TAFs through 06z Wednesday Night) Issued at 1126 PM CDT Tue Apr 22 2014 VFR flight conditions expected through the forecast period with clear skies or scattered mid-hi clouds overnight and mid-high clouds on Wednesday. Light winds tonight will become southeasterly and increase on Wednesday morning. Specifics for KSTL: VFR flight conditions expected through the forecast period with clear skies or scattered mid-hi clouds overnight and mid-high clouds on Wednesday. Light winds tonight will become southeasterly and increase on Wednesday morning. Glass && .PRELIMINARY POINT TEMPS/POPS: Saint Louis 69 52 72 52 / 5 10 80 30 Quincy 66 49 66 46 / 10 20 80 20 Columbia 72 53 70 47 / 10 30 80 10 Jefferson City 75 53 70 47 / 10 20 80 10 Salem 65 49 72 49 / 5 5 70 50 Farmington 69 48 73 47 / 5 5 80 30 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
401 AM CDT WED APR 23 2014 .SYNOPSIS... ISSUED AT 356 AM CDT WED APR 23 2014 H5 ANALYSIS FROM EARLIER THIS EVENING HAS A RIDGE OF HIGH PRESSURE EXTENDING FROM THE SOUTHERN PLAINS...NWD INTO NORTHERN SASKATCHEWAN. OFF TO THE WEST...AN UPPER LEVEL LOW WAS NOTED OFF THE COAST OF BRITISH COLUMBIA WITH A TROUGH EXTENDING SSE OF THIS FEATURE INTO SOUTHERN CALIFORNIA. WV IMAGERY AS OF 06Z TONIGHT HAS A NICE SHORTWAVE OVER NRN UTAH AND SERN IDAHO. IN ADVANCE OF THIS FEATURE...THUNDERSTORMS WERE PRESENT ACROSS NWRN COLORADO AND SRN WYOMING. FURTHER EAST...ISOLATED THUNDERSTORMS WERE PRESENT OVER SOUTH DAKOTA...AS WELL AS NORTH CENTRAL KS AND PORTIONS OF SOUTH CENTRAL AND SOUTHEASTERN NEBRASKA. THIS ACTIVITY HAS INCREASED SOMEWHAT IN COVERAGE OVER THE PAST 1 TO 2 HRS THANKS TO A 50+KT LOW LEVEL JET WHICH EXTENDS FROM SOUTH CENTRAL INTO NORTH CENTRAL NEBRASKA. AT THE SURFACE...ACROSS WESTERN AND NORTH CENTRAL NEBRASKA...GUSTY SOUTHEASTERLY WINDS WERE PRESENT EAST OF A LINE FROM AINSWORTH TO OGALLALA THANKS TO A SURFACE LOW OVER SERN MT...WITH A SURFACE TROUGH EXTENDING SWD INTO EASTERN COLORADO. SUSTAINED SPEEDS WERE GENERALLY 15 TO 25 MPH...WITH SOME GUSTS UP TO 35 MPH. UNDER PARTLY CLOUDY SKIES...3 AM CDT TEMPERATURES RANGED FROM 53 AT BROKEN BOW TO 60 AT IMPERIAL AND THEDFORD. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 356 AM CDT WED APR 23 2014 OVER THE NEXT 24 HOURS...PRECIPITATION CHANCES AND THE SEVERE THREAT IN THE EASTERN FORECAST AREA ARE THE MAIN FORECAST CONCERN. OTHER CONCERNS CENTER ON WINDS THIS MORNING IN THE EAST...ALONG WITH THE FIRE DANGER THREAT IN THE WEST THIS AFTERNOON. FOR THIS MORNING...THE BEFOREMENTIONED SURFACE TROUGH OF LOW PRESSURE WILL ENTER THE PANHANDLE BY MID MORNING. STRONG SOUTHERLY WINDS WILL CONTINUE ACROSS THE EASTERN QUARTER OF THE FORECAST AREA THROUGH MID MORNING AS A 40 TO 50 KT LOW LEVEL JET REMAINS PRESENT ACROSS THE FAR NERN CWA. THIS FEATURE WILL SLIDE EAST OF THE FORECAST AREA BY 18Z WHILE THE SURFACE TROUGH PUSHES EAST TO A LINE FROM VALENTINE...TO NORTH PLATTE TO HAYES CENTER. GIVEN THE STRONG LOW LEVEL JET THIS MORNING...WE COULD FLIRT WITH WIND ADVISORY CRITERIA WINDS IN THE FAR NORTHEASTERN CWA THROUGH LATE MORNING. RIGHT NOW...BASED ON THE HRRR AND STATISTICAL GUIDANCE...FCST WINDS ARE JUST BELOW ADVISORY CRITERIA AND PLAN ON NO HEADLINES ATTM. WILL CONTINUE TO MONITOR THIS THROUGH SUNRISE AS THE H85 JET MIGRATES FROM THE HIGHWAY 83 CORRIDOR EAST TOWARD SUNRISE. LATER THIS AFTERNOON...A STRONG UPPER LEVEL DISTURBANCE WILL APPROACH WESTERN NEBRASKA. AS CAPPING ERODES DURING THE LATE AFTERNOON HOURS...THUNDERSTORMS ARE EXPECTED TO FIRE INVOF OF THE SURFACE TROUGH. ATTM...THIS FEATURE IS EXPECTED TO BE ALONG A LINE FROM BASSETT TO NORTH PLATTE TO EAST OF HAYES CENTER. STRONG SOUTHERLY WINDS EAST OF THE TROUGH...WILL PUSH PLENTY OF LOW LEVEL MOISTURE NWD FROM CENTRAL KS TDY. WITH MOISTURE IN PLACE...AND STRONG INSTABILITY...THUNDERSTORMS LOOK LIKE A SAFE BET ALONG AND EAST OF THE SURFACE TROUGH THIS AFTERNOON. IN OUR FAR SOUTHEAST AND EASTERN ZONES...SHEAR WILL BE FAVORABLE FOR SEVERE STORMS THIS AFTERNOON INTO THE EVENING HOURS. AT THIS TIME...HAIL AND WINDS WILL BE THE MAIN SEVERE THREAT AS DEEP LAYER WIND SHEAR IS UNIDIRECTIONAL. WITH THE POSITION OF THE BEFOREMENTIONED SURFACE TROUGH...PRECIP CHANCES WILL BE HIGHEST IN FAR EASTERN PORTIONS OF THE FORECAST AREA WITH HIGH CHANCE TO LOW LIKELY POPS ALONG AND EAST OF A LINE FROM ONEILL...TO BROKEN BOW...TO MAYWOOD. POPS WILL DECREASE QUICKLY WEST OF THIS LINE...WITH NO PRECIPITATION EXPECTED WEST OF A LINE FROM VALENTINE...TO SUTHERLAND...TO GRANT. THE SURFACE TROUGH WILL BE FORCED EAST OF THE FORECAST AREA BY MID EVENING...WITH THE THREAT FOR THUNDERSTORMS IN THE EAST ENDING BY MIDNIGHT TONIGHT. WITH RESPECT TO FIRE DANGER THIS AFTERNOON...WEST OF THE SURFACE TROUGH...EXTREME TO NEAR CRITICAL FIRE DANGER WILL BE POSSIBLE LATER THIS AFTERNOON...AS DRIER AIR PUSHES INTO THE PANHANDLE BEHIND THE SURFACE TROUGH. DEW POINTS WILL DROP INTO THE TWENTIES IN THE EASTERN PANHANDLE BY LATE AFTERNOON AND WITH TEMPERATURES IN THE MID TO UPPER 60S EXPECTED...RELATIVE HUMIDITIES WILL DROP TO AROUND 20 PERCENT. BREEZY WESTERLY WINDS MAY BECOME GUSTY LATER THIS AFTERNOON...PARTICULARLY IN THE EASTERN PANHANDLE THANKS TO DECENT 3 HR SURFACE PRESSURE RISES OF 3 TO 5 MB FROM 21Z TO 00Z LATE THIS AFTERNOON. ATTM...EXPECTED MINIMUM RELATIVE HUMIDITIES WILL BE JUST ABOVE RED FLAG CRITERIA SO NO FIRE HEADLINES ARE EXPECTED AT THIS TIME. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 356 AM CDT WED APR 23 2014 DRY AIR WILL BE IN PLACE THURSDAY BEHIND WEDNESDAY/S COLD FRONTAL PASSAGE. WILL BE CLOSE TO RED FLAG CRITERIA...IN WELL MIXED AND DRY ATMOSPHERE. 500M WIND SPEEDS OF 10 TO 20 KTS WILL SUPPORT SUSTAINED SURFACE WIND SPEEDS OF 15 TO 20 MPH...BUT THESE WINDS WILL SLOWLY BE DIMINISHING DURING THE TIME OF LOWEST RELATIVE HUMIDITY. WILL CONTINUE THE MENTION OF THE FIRE WEATHER CONCERN IN THE HAZARDOUS WEATHER OUTLOOK...AND HAVE THE ONCOMING SHIFT TAKE ANOTHER LOOK BEFORE ISSUING ANY TYPE OF FIRE WEATHER HEADLINES. A CHILLY NIGHT EXPECTED THURSDAY NIGHT...AS SURFACE HIGH RIDGE AXIS CROSSES THE AREA AND WINDS DECOUPLE. NOT EXPECTING BELOW FREEZING TEMPERATURES AT THIS POINT...BUT FAVORED LOW SPOTS AND RIVER VALLEYS WILL LIKELY SEE LOWS BOTTOMING OUT IN THE MIDDLE 30S. WARM AIR ADVECTION GETS UNDERWAY IN ERNEST FRIDAY...WITH SOUTHERLY FLOW ADVECTING H85 TEMPERATURES OF 20C INTO SOUTHWEST NEBRASKA BY AFTERNOON. ALL AREAS SHOULD SEE HIGHS INTO THE 70S. STILL SOME CONCERN REGARDING WILDFIRE POTENTIAL...BUT IT APPEARS THAT WINDS WILL REMAIN IN CHECK...AND DEW POINTS WILL BE SLOWLY RISING INTO THE 30S DURING THE AFTERNOON. SOUTHERLY LOW LEVEL JET CRANKS UP FRIDAY NIGHT IN RESPONSE TO DEVELOPING LOW PRESSURE ALONG THE LEE OF THE ROCKIES. THE NAM MODEL IS THE MOST AGGRESSIVE WITH THE MOISTURE RETURN AND STEEP MID LEVEL LAPSE RATES...AND THE MODEL DEVELOPS SOME DECENT MID LEVEL CAPE AS A RESULT. THE OTHER MODELS ARE SLOWER WITH THE MOISTURE RETURN...AND THE MID LEVEL LAPSE RATES ARE NOT AS STEEP. THEREFORE THESE MODELS ARE INDICATING LESS IN THE WAY OF INSTABILITY. WILL CONTINUE THE SLIGHT CHANCE OF SHOWERS IN THE FORECAST...AND WILL ADD AN ISOLATED THUNDER MENTION TO ACCOUNT FOR THE INCREASING MID LEVEL INSTABILITY IN THE NAM. FOR THE WEEKEND...A POTENT UPPER LEVEL TROUGH OF LOW PRESSURE WILL MOVE ONSHORE THE PACIFIC COAST FRIDAY EVENING. THE 23/00Z GFS AND ECMWF MODEL RUNS ARE IN EXCELLENT AGREEMENT...AND HAVE THE BASE OF THE UPPER LEVEL TROUGH SWINGING THOUGH SOUTHEAST CALIFORNIA/WESTERN ARIZONA AT 18Z SATURDAY. AT THE SURFACE...BOTH MODELS RAPIDLY DEEPEN A SURFACE LOW /NEAR 988MB/ DOWNSTREAM IN FAVORED CYCLOGENESIS REGION OF EASTERN COLORADO BY 00Z SUNDAY. THIS WILL HELP DRAW GULF MOISTURE RAPIDLY NORTHWARD INTO THE CENTRAL PLAINS. THE GFS...ECMWF AND THE GEFS ENSEMBLE MEAN REMAIN IN GOOD AGREEMENT THROUGH SUNDAY...AND BRING A POTENT/DYNAMIC NEGATIVELY TILTED UPPER TROUGH INTO THE CENTRAL PLAINS...WITH A CLOSED H5 AND H7 CIRCULATION CENTER ACROSS WESTERN KANSAS. MEANWHILE A DEEP 985MB SURFACE LOW WILL SLOWLY MIGRATE EASTWARD NEAR THE KANSAS/NEBRASKA BORDER THROUGH MONDAY. REGARDING THUNDERSTORM AND PRECIPITATION CHANCES...SEVERE WEATHER SEEMS LIKELY GIVEN SUCH STRONG DYNAMICS AND GOOD MOISTURE. IT WILL OF COURSE HINGE ON WHERE THE BOUNDARIES SET UP. THERE WILL LIKELY BE A SHARP WARM FRONT AND DRY LINE FOR CONVECTION TO FOCUS ON/NEAR. WILL NOT TRY TO PIN DOWN EXACT LOCATION OF THESE FEATURES JUST YET...BUT INDICATIONS ARE THAT BOTH THESE BOUNDARIES MAY BE IN OR VERY NEAR THE FORECAST AREA FOR MUCH OF THE WEEKEND. WITH SUCH A STRONG SYSTEM...THERE WILL ALSO BE A PRONOUNCED DRY SLOT. THE CURRENT STORM TRACK ACROSS NORTHERN KANSAS SUNDAY INTO MONDAY...WOULD FAVOR THE DRY SLOT AIMING MORE AT SOUTHERN/SOUTHEAST NEBRASKA NEBRASKA. THIS IS GOOD NEWS FOR OUR AREA...AS A PERSISTENT SHIELD OF RAIN COULD LINGER FOR MANY HOURS. THIS HAS THE POTENTIAL TO BE A SIGNIFICANT AND SLOW MOVING STORM SYSTEM...AND WILL CONTINUE TO MONITOR THE LATEST TRENDS CLOSELY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1202 PM CDT TUE APR 23 2014 BREEZY CONDITIONS ARE EXPECTED OVER THE NEXT 20 HOURS AT THE TAF SITES AS GUSTY SOUTHERLY WINDS SWITCH TO THE NORTHWEST TOMORROW EARLY IN THE AFTERNOON. A FEW SHOWERS...AND POSSIBLY A THUNDERSTORM...MAY AFFECT THE TERMINALS TONIGHT. HOWEVER...THE CHANCE IS RATHER LOW. THUNDERSTORMS MAY DEVELOP TOMORROW AFTERNOON IN THE VICINITY OF KLBF EARLY IN THE AFTERNOON...DEPENDING ON THE TIMING OF THE FRONT. WILL CONTINUE WITHOUT TS MENTION AT KLBF UNTIL MODELS COME IN BETTER AGREEMENT WITH FRONTAL LOCATION/TIMING. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...TAYLOR AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1202 AM CDT WED APR 23 2014 .UPDATE... ISSUED AT 824 PM CDT TUE APR 22 2014 UPDATE INCLUDED FRESHENING UP CLOUD COVER ACROSS THE AREA FOR TONIGHT. OTHERWISE...FORECAST LOOKS ON TRACK WITH ISOLATED SHOWERS AND THUNDERSTORMS EXPECTED TONIGHT. CURRENTLY...ONLY A FEW SHOWERS/THUNDERSTORMS EXIST ACROSS THE NORTHWEST. LATE TONIGHT...THE POSSIBILITY EXISTS FOR ACTIVITY INCREASING IN THE NORTHEAST IN RESPONSE TO THE LOW LEVEL JET. THE LATEST RAP HAS 400-700 J/KG OF MUCAPE IN THE NORTHEAST LATE. WILL WAIT FOR LATEST NAM BEFORE MAKING CHANGES TO PRECIP FORECAST. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 400 PM CDT TUE APR 22 2014 AT 20Z WATER VAPOR IMAGERY SHOWED AN AMPLIFIED PATTERN IN THE UPPER LEVELS WITH A TROUGH OVER THE EASTERN CONUS...RIDGING OVER THE PLAINS...AND A DEEP TROUGH OVER THE WEST COAST. A GOOD FETCH OF MID AND HIGH LEVEL MOISTURE WAS SEEN AHEAD OF THE TROUGH WITH QUITE A BIT OF CLOUD COVER MOVING INTO THE CENTRAL PLAINS. AT THE SURFACE...A BROAD AREA OF LOW PRESSURE DEVELOPED ON THE LEE SIDE OF THE ROCKIES THROUGH THE DAY WHICH TIGHTENED THE PRESSURE GRADIENT ACROSS NEBRASKA. THIS BROUGHT BREEZY SOUTHERLY WINDS TO THE ENTIRETY OF THE FORECAST AREA THROUGH THE DAY WITH FREQUENT SPEEDS OF 25 MPH WITH GUSTS TO 35 MPH. THIS SOUTHERLY FLOW BROUGHT WARM AIR AND MOISTURE NORTHWARD THROUGH THE DAY...WITH HIGHS INTO THE 70S FOR MUCH OF THE AREA...WHILE DEW POINTS INCREASED INTO THE 40S IN PARTS OF THE PANHANDLE. EVEN WITH THE INCREASE IN DEW POINTS...THE BOUNDARY LAYER REMAINS VERY DRY. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS HAD BEEN DEVELOPING OVER THE PANHANDLE AND NORTHEAST COLORADO THIS AFTERNOON...BUT DUE TO THE DRY AIR...CLOUD BASES WERE AT OR ABOVE 10K FEET. FOR THE REMAINDER OF THE AFTERNOON...SPC MESOANALYSIS SHOWED AREAS OVER THE PANHANDLE HAD BUILT UP TO 500 J/KG MUCAPE. WITH SUFFICIENT LIFT ONGOING ACROSS THE AREA AND SOME INSTABILITY...EXPECT THE SHOWER AND THUNDERSTORM ACTIVITY TO CONTINUE...AND WILL SLOWLY MAKE AN EASTWARD PROGRESSION INTO THIS EVENING. FORECAST MODELS SHOW THAT AS THE ENTIRE SYSTEM PROGRESSES EAST THIS EVENING AND OVERNIGHT SOME INSTABILITY IN THE MID LEVELS WILL MIGRATE EAST ACROSS THE FORECAST AREA. THE AMOUNT OF INSTABILITY WILL BE QUITE WEAK THOUGH...WITH 100-200 J/KG. WITH THE LOSS OF DAYTIME HEATING...AND WITH THE WEAKENING INSTABILITY EXPECT ANY ACTIVITY TO DIMINISH THIS EVENING AS IT MOVES EAST. THE ONE THING TO WATCH WILL BE IF THE INCREASE OF THE LOW LEVEL JET TONIGHT WILL BE ENOUGH TO KEEP ACTIVITY GOING. AT THIS TIME...WITH THE AMOUNT OF DRY AIR ACROSS THE AREA...DON/T THINK THE LLJ WILL BE ENOUGH TO OVERCOME THE DRY AIR AND DON/T EXPECT MUCH FOR PRECIPITATION IN THE OVERNIGHT HOURS. WINDS WILL STAY STRONG OVERNIGHT AS THE PRESSURE GRADIENT STAYS TIGHT. THE STRONG WINDS WILL KEEP TEMPERATURES FROM DROPPING TONIGHT...SO LOOKING AT LOWS IN THE UPPER 40S AND 50S. ON WEDNESDAY...THE UPPER LEVEL TROUGH WILL LIFT NORTHEAST WHICH WILL PUSH A COLD FRONT ACROSS THE FORECAST AREA BY THE END OF THE DAY. WINDS WILL STAY STRONG AHEAD OF THE FRONT...WHICH BY 18Z LOOKS TO BE ROUGHLY FROM KMCK TO KONL. THERE COULD BE A PERIOD OF TIME WHEN WINDS APPROACH WIND ADVISORY CRITERIA OVER THE NORTHEAST PART OF THE FORECAST AREA. THE PERIOD OF THE HIGHEST WINDS WOULD BE FROM AROUND 06Z TO 15Z...BUT WITH IT BEING IN AN AREA OF WARM AIR ADVECTION AND NOT SUBSIDENT AIR...AND ALSO IT BEING IN THE OVERNIGHT HOURS...DON/T KNOW IF THE STRONGEST WINDS WILL BE ABLE TO MAKE IT TO THE SURFACE. THEN IN THE AFTERNOON...MOISTURE WILL POOL AHEAD OF THE FRONT WITH DEW POINTS RISING UP AROUND 50 OR HIGHER. STORMS SHOULD DEVELOP ALONG AND AHEAD OF THE FRONT LATER IN THE AFTERNOON...AND THE PLACEMENT OF THE FRONT WILL DEPEND WHAT AREAS SEE RAINFALL. DID PUSH CHANCES EAST SLIGHTLY...BUT THINK THE STORMS MAY SKIRT THE EASTERN PART OF THE FORECAST AREA. WHEREVER STORMS DO FORM...THEY WILL LIKELY BE STRONG TO EVEN SEVERE AS STRONGER INSTABILITY IS EXPECTED...ALONG WITH STRONG DEEP LEVEL SHEAR AS THE SYSTEM IS QUITE DYNAMIC. WILL BE WATCHING THESE CHANCES CLOSELY OVER THE NEXT 18 TO 24 HOURS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 400 PM CDT TUE APR 22 2014 INITIAL UPPER PV ANOMALY ROTATING ACROSS MT THROUGH THE NEGATIVELY TILTED UPPER LOW WILL ENHANCE CONVERGENCE ALONG THE WARM FRONT LOCATED ACROSS THE UPPER MIDWEST AND NORTHERN PLAINS EARLY...BUT AS THE NEXT ANOMALY MOVES THROUGH THE LONG WAVE TROUGH AS IT PROGRESSES EWD IT WILL ENHANCE CONVERGENCE ALONG THE SWD ADVANCING COLD FRONT ACROSS NEBRASKA WED NIGHT...AND ALONG THE DRYLINE IN WRN KS SWD INTO WEST TX. BY WED NIGHT THE FRONT WILL BE THROUGH MOST OF THE LBF CWA AND WILL TREND THE PRECIP CHCS EWD THROUGH EARLY MORNING...THEN DRY WHICH THE CURRENT GFCST HAS HANDLED WELL. UPPER LOW THEN MOVES INTO THE GREAT LAKES REGION AS TRANSITORY RIDGING MOVES INTO THE CENTRAL ROCKIES. AS THIS OCCURS WESTERLY DOWNSLOPE WINDS WILL REMAIN IN THE BREEZY CATEGORY WITH VERY DRY LOW LEVELS REMAINING. THIS WILL MEAN ANOTHER DAY NEAR CRITICAL FIRE WEATHER CONDITIONS...THOUGH AT THIS TIME WINDS SHOULD REMAIN JUST BELOW CRITERIA THOUGH RH VALUES WILL DROP IN TO THE TEENS IN PORTIONS OF THE SOUTHEAST PANHANDLE INTO SOUTHWEST NEBRASKA. DESPITE THE AREA NEING IN A POST-FRONTAL ENVIRONMENT TEMPS WILL REACH ABOVE AVERAGE IN MOST LOCATIONS UNDER FULL SUN. DRY CONDITIONS WILL PREVAIL INTO FRIDAY AS WELL AS TRANSITORY RIDGE MOVES EAST INTO THE PLAINS. NEXT HIGH AMPLITUDE UPPER LOW MOVES ONSHORE OVER CA FRIDAY NIGHT. BEYOND THIS PERIOD MODEL HAVE VARYING SOLUTIONS TO HOW THIS NEXT SIGNIFICANT WEATHER MAKER EVOLVES. THE 22.12Z RUN OF THE ECMWF HAS SIGNIFICANT DIFFERENCES FROM THE 22.00Z RUN...MOVING THE WARM FRONT MUCH FURTHER NORTH WITH THE LATEST RUN...LOCATED OVER NRN NEB INTO SRM SD. THE POSITION OF THIS WARM FRONT IS SIGNIFICANT BECAUSE WITH THE SYSTEM EVOLVING TO BECOME NEGATIVELY TILTED OVER TIME AS ALL MODELS DO...THE LEAD UPPER PV ANOMALY WITH ENHANCE CONVERGENCE ALONG THE WARM FRONT INITIALLY AND WITH THE POTENTIAL FOR GOOD LOWER LEVEL SHEAR ALONG AND NORTH OF THE WARM FRONT...POTENTIAL FOR SEVERE WEATHER...BOTH AMOUNT AND TYPE OF SEVERE...RESTS HEAVILY WITH THE POSITION OF THIS WARM FRONT. GFS POSITIONS THE WARM FRONT IN KS...FURTHER SOUTH THAN THE ECMWF AND SIMILAR TO THE 22.12Z RUN OF THE CANADIAN MODEL. SEVERE WEATHER WILL BE A DISTINCT POSSIBILITY IN THE PLAINS THIS WEEKEND...THOUGH THE DETAILS OF WHICH WILL HAVE TO BE IRONED OUT IN THE NEXT FEW DAYS. MODELS THEN CONTINUE TO CUT OFF THE UPPER LOW FROM THE MAIN FLOW AND REDEVELOP IT ACROSS THE MID MISSISSIPPI VALLEY IN SOME FASHION...BUT AGAIN TIMING AND LOCATION DIFFERENCES ARE SIGNIFICANT BUT WILL LIKELY KEEP THE AREA UNSETTLED...COOLER THAN AVERAGE AND BETTER CHANCES FOR PRECIP...INTO THE FIRST PART OF NEXT WEEK. ALONG WITH THE POSITION DIFFERENCES ARE SIGNIFICANT TEMPERATURE DIFFERENCES WITH THE ECMWF BEING MUCH COLDER. THIS WILL ALSO LEAD TO A LOW CONFIDENCE IN PRECIPITATION TYPE FOR THE OVERNIGHT PERIODS SUNDAY NIGHT INTO MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1202 PM CDT TUE APR 23 2014 BREEZY CONDITIONS ARE EXPECTED OVER THE NEXT 20 HOURS AT THE TAF SITES AS GUSTY SOUTHERLY WINDS SWITCH TO THE NORTHWEST TOMORROW EARLY IN THE AFTERNOON. A FEW SHOWERS...AND POSSIBLY A THUNDERSTORM...MAY AFFECT THE TERMINALS TONIGHT. HOWEVER...THE CHANCE IS RATHER LOW. THUNDERSTORMS MAY DEVELOP TOMORROW AFTERNOON IN THE VICINITY OF KLBF EARLY IN THE AFTERNOON...DEPENDING ON THE TIMING OF THE FRONT. WILL CONTINUE WITHOUT TS MENTION AT KLBF UNTIL MODELS COME IN BETTER AGREEMENT WITH FRONTAL LOCATION/TIMING. && .FIRE WEATHER... ISSUED AT 433 PM CDT TUE APR 22 2014 FIRE WEATHER CONCERNS WILL HEIGHTEN ON WEDNESDAY BEHIND A COLD FRONT AS DRY AIR PUSHES INTO THE AREA...ALONG WITH BREEZY WEST TO NORTHWEST WINDS. AT THIS TIME...MINIMUM RELATIVE HUMIDITY IS EXPECTED TO BE 15 TO 25 PERCENT WITH WINDS BLOWING AT 15 TO 25 MPH. THEN ON THURSDAY...DRY AIR WILL FILTER INTO THE AREA AS DEW POINTS LOOK TO FALL INTO THE TEENS. TEMPERATURES IN THE 60S TO LOW 70S WILL EQUATE TO RELATIVE HUMIDITY DROPPING TO NEAR 15 PERCENT. WINDS WILL BE BREEZY OUT OF THE WEST TO NORTHWEST...BUT THERE IS UNCERTAINTY TO HOW STRONG THEY WILL GET. BOTH DAYS ARE LOOKING TO HAVE NEAR HIGH FIRE WEATHER CONDITIONS...BUT MAY STAY JUST UNDER CRITICAL LEVELS. WILL BE CLOSELY WATCHING THIS IN THE FORECAST THROUGH THURSDAY. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KNUTSVIG SHORT TERM...BROOKS LONG TERM...JWS AVIATION...KNUTSVIG FIRE WEATHER...BROOKS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1201 AM CDT WED APR 23 2014 .SHORT TERM...(TONIGHT THROUGH FRIDAY) ISSUED AT 330 PM CDT TUE APR 22 2014 MAIN FORECAST CONCERN WILL BE CENTERED AROUND THUNDERSTORM CHANCES THROUGH THURSDAY MORNING. MID/UPPER LEVEL TROUGH AXIS EXTENDS ACROSS THE INTERMOUNTAIN WEST WITH IMPRESSIVE 130M HEIGHT FALLS OUT AHEAD OF IT. THIS TROUGH WILL CONTINUE TO MOVE EAST AND AHEAD OF IT...A DEEPENING LEE SIDE SFC LOW WILL EXTEND ACROSS THE HIGH PLAINS BY 12Z WED. AHEAD OF ALL OF THIS...STRONG LOW LEVEL SOUTHERLY FLOW WILL BRING BOTH WARM AND MOIST AIR ADVECTION INTO THE REGION. AN FEW RADAR RETURNS ARE SHOWING UP UNDER THE ACCAS FIELD OVER CENTRAL NEBRASKA THIS AFTERNOON. THE HRRR HAS PICKED UP ON THIS BUT WITH LITTLE UPPER LEVEL SUPPORT IN THE AREA JUST YET...THINK THESE WILL FADE AS THEY APPROACH A MUCH DRIER AIRMASS THIS EVENING. NOCTURNAL 850MB WINDS ON THE ORDER OF 50-60KTS ARE FORECAST OVERNIGHT WHICH WILL HELP ADVECT +8 TO +10C DEWPOINTS INTO THE AREA BY WED AFTERNOON. WILL CONTINUE OVERNIGHT/EARLY MORNING TSTM CHANCES IN ASSOCIATION WITH THE STRENGTHENING LLVL JET. A TIGHTENING SURFACE PRESSURE GRADIENT BETWEEN THE RETREATING HIGH PRESSURE CURRENTLY OVERHEAD NOW AND THE APPROACHING HIGH PLAINS LOW WILL BRING QUITE GUSTY WINDS TO THE AREA WED MORNING AND THROUGH THE EARLY AFTERNOON. WITH COORDINATION FROM SURROUNDING OFFICES...WILL HOIST A WIND ADVISORY FOR PORTIONS OF OUR WEST AND NORTH FROM 15-21Z. EXPECT A LULL IN TSTM ACTIVITY DURING THE LATE MORNING/EARLY AFTERNOON HOURS WEDNESDAY. THE SFC LOW WILL BE ENTERING INTO WESTERN KANSAS BY 00Z THU WITH COLD FRONT PUSHING THROUGH CENTRAL NEBRASKA. THE GREATEST INSTABILITY WILL EXIST OVER NORTH CENTRAL KANSAS AND SOUTH CENTRAL NEBRASKA AT THIS TIME WITH BULK 0-6KM SHEAR ON THE ORDER OF 50KTS. CONVECTION IS LIKELY TO DEVELOP ALONG/AHEAD OF THE COLD FRONT AND SPREAD EAST THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS WITH LARGE HAIL AND DAMAGING WINDS AS THE PRIMARY HAZARDS. PW`S BY EARLY EVENING DO INCREASE TO AROUND 1.50" SO THE POTENTIAL EXISTS FOR SOME HEAVIER RAINFALL AMOUNTS. THE UPPER TROUGH IS FORECAST TO SWING THROUGH CENTRAL NEB BY 12Z THURSDAY WITH THE SFC COLD FRONT WELL INTO IOWA BY THAT TIME. LINGERING POST FRONTAL PCPN IS QUITE POSSIBLE IN OUR EASTERN COUNTIES IN THE MORNING. BROAD/WEAK UPPER RIDGING WILL MOVE OVERHEAD ON FRIDAY WITH STRONG SOUTHERLY FLOW SO WE SHOULD BE ABLE TO WARM INTO THE LOW 70S FRIDAY. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 PM CDT TUE APR 22 2014 GLOBAL MODELS ARE CONSISTENT IN MOVING A TROUGH ACROSS THE ROCKIES AND INTO THE CENTRAL PLAINS THIS WEEKEND. THE MODELS DIVERGE TO SOME DEGREE AS TO HOW QUICKLY TO MOVE THE TROUGH OUT OF THE AREA WITH LITTLE IN THE WAY OF AN UPSTREAM KICKER. THE 00Z ECMWF IS HOLDING ONTO THIS TROUGH INTO THE DAY ON MONDAY AS THE SLOWEST SOLUTION. AHEAD OF THE SYSTEM MODIFIED GULF AIR WILL BE ADVANCING NORTHWARD ON SATURDAY. MOST OF THE DAY ON SATURDAY SHOULD BE DRY BUT A COLD FRONT WILL MOVE INTO NORTHEAST NEBRASKA BY AFTERNOON AND THIS COULD BE THE IMPETUS OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS BY AFTERNOON. AS LARGER-SCALE FORCING INCREASES ON SATURDAY NIGHT...ALONG WITH STRONGER LOW LEVEL WARM-AIR ADVECTION WE SHOULD SEE AN INCREASE IN THE AREAL EXTENT OF THE PRECIP...AND LIKELY POPS APPEAR WARRANTED AT THIS TIME. THE 00Z GFS/GEM WOULD THEN SHIFT THIS FORCING/PRECIP SOUTH OF THE AREA BY SUNDAY NIGHT WHILE THE ECMWF WOULD CONTINUE SOME THREAT INTO MONDAY. ALTHOUGH THE SLOWER SOLUTION OF THE ECMWF ISN`T OUT OF THE QUESTION...GIVEN THE LIMITED SUPPORT WILL CONT WITH A DRY FORECAST FOR SUNDAY NIGHT THROUGH TUESDAY. TEMPERATURES WILL WARM INTO THE 70S FOR MOST AREAS ON SATURDAY AHEAD OF THE COLD FRONT...BUT WITH THE PRECIP AND CAA ON SUNDAY TEMPERATURES WILL LIKELY HOLD IN THE 60S. TEMPERATURES SHOULD BE ON THE INCREASE FOR MON/TUE AS A WESTERN US RIDGE DEVELOPS EAST INTO THE CENTRAL US. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1142 PM CDT TUE APR 22 2014 SFC PRES GRADIENT HAS RELAXED ACROSS ERN NEB...BUT LLWS WILL REMAIN AN ISSUE THRU ABOUT 12Z WED MORNING. LATEST GUIDANCE SUGGESTING AREA OF -TSRA ACTIVITY CURRENTLY WEST OF THE AREA WILL MOVE THRU ERN NEB LATER THIS MORNING...THUS HAVE INCLUDED TEMPO GROUPS AT ALL TERMINALS FOR OCCASIONAL -TSRA/MVFR COND. SFC WINDS WILL REMAIN STRONG ACROSS ERN NEB TODAY WITH SLY WINDS GUSTING AROUND 30KT. FOCUS SHIFTS TO WED EVENING THEN WHEN NEXT ROUND OF TSRA IS EXPECTED TO DEVELOP ALONG APPROACHING COLD FRONT. FEEL CONFIDENT ENOUGH TO GO WITH TEMPO GROUPS THAT FAR OUT GIVEN MODELS HAVE BEEN QUITE CONSISTENT ADVERTISING THIS STORM SYSTEM. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY FROM 10 AM TO 4 PM CDT WEDNESDAY FOR NEZ011-012- 015>018-030>034-042>044-050-051-065-066-078-088-089. IA...WIND ADVISORY FROM 10 AM TO 4 PM CDT WEDNESDAY FOR IAZ043. && $$ SHORT TERM...KERN LONG TERM...MILLER AVIATION...DEE
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1255 AM EDT WED APR 23 2014 .SYNOPSIS... LOW PRESSURE WILL AFFECT THE NORTH COUNTRY TONIGHT RIGHT INTO WEDNESDAY NIGHT...WITH HIGH PRESSURE BUILDING OVER THE AREA FOR THURSDAY AND REMAINING RIGHT INTO FRIDAY MORNING. A LOW PRESSURE SYSTEM APPROACHES DURING THE DAY FRIDAY AND AFFECTS THE REGION RIGHT INTO THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1255 AM EDT WEDNESDAY...ISOLATED TO SCT SHOWERS CONTINUE...MAINLY ACROSS NRN NY AND INTO THE CPV. AS UPPER TROUGH CONTINUES TO DIG INTO CENTRAL PA...CLOUDS AND THREAT OF SCT SHOWERS WILL CONTINUE THIS MORNING. OVERALL FCST IN GOOD SHAPE WITH MIN TEMPS GENERALLY RANGING FROM 30S TO M40S. PREVIOUS DISCUSSION...LOW PRESSURE TRACKING ACROSS NORTHEAST VERMONT LATE THIS EVENING. INITIAL COLD FRONT ASSOCIATED WITH THE LOW...WHICH IS MORE OF A WIND SHIFT THAN A CHANGE IN AIRMASS...HAS JUST ABOUT EXITED VERMONT. SECONDARY FRONT...BEHIND WHICH LIES THE COLDER AIR...IS STILL BACK IN THE OTTAWA VALLEY. THIS SECOND BOUNDARY COUPLED WITH RATHER STRONG UPPER AIR DISTURBANCE MOVING EAST FROM THE GREAT LAKES...WILL RESULT IN CONTINUED CHANCE OF SHOWERS OVERNIGHT. AS FLOW TURNS MORE NORTHERLY BEHIND DEPARTING LOW...PRECIPITATION WILL BECOME MORE OROGRAPHIC IN NATURE...WITH FOCUS OVER HIGHER TERRAIN. AS AIRMASS COOLS...LOOK FOR A CHANGEOVER TO SNOW SHOWERS OVER THE MOUNTAINS. GOING FORECAST HAS IT ALL COVERED FAIRLY WELL. ONLY CHANGE WAS TO MAKE A FEW MINOR ADJUSTMENTS TO TEMPS BASED ON LATEST OBS AND TRENDS. THE RESULT WAS TO RAISE MINS A COUPLE OF DEGREES MOST AREAS. EXPECT LOWS IN THE UPPER 30S TO MID 40S. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/... AS OF 407 PM EDT TUESDAY...GOING INTO WEDNESDAY...SFC/UPPER LOW HAVE SHIFTED EAST OF THE REGION...SETTING THE AREA UP FOR NORTHERLY FLOW FOR THE NEXT SEVERAL PERIODS. FOCUS OF PRECIP WILL BE OVER HIR TRRN DUE TO UPSLOPE/OROGRAPHIC CONDITIONS...WITH A SLOW TAPER OF AREAL COVERAGE FROM WEST TO EAST WITH APPROACH OF SFC HIGH PRESSURE FROM THE CENTRAL PORTION OF THE COUNTRY. TEMPS WARM ENOUGH TO KEEP VALLEY LOCALES ALL -RW DURING THE DAY WEDNESDAY WITH -RW/-SW MIX FOR HIR TRRN. AREAS SHOULD SEE A COUPLE TENTHS OVERALL FOR QPF...WITH UP TO AN INCH OF -SW OVER HIR TRRN. POPS DUE TAPER SHARPLY GOING INTO WEDNESDAY NIGHT W/ MAIN FOCUS BEING NE VT TOWARDS THURSDAY MORNING. LINGERING LIGHT PRECIP IN NE VT FOR THURSDAY MORNING GIVING WAY TO HIGH PRESSURE FOR THURSDAY AND THURSDAY NIGHT. DECENT 24-HR STRETCH OF WX DURING THIS TIME ONCE -RW/-SW CLRS THE NE KINGDOM. OVERALL FOR TEMPS 40S MAINLY FOR WEDNESDAY HIGHS AND LIFTING INTO THE 50S FOR THURSDAY WITH AREA SEEING FULL SUNSHINE. OVERNGT LOWS WILL RANGE FROM THE 30S IN VALLEY LOCALES DOWN TO THE TEENS/20S IN HIR TRRN. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 400 PM EDT TUESDAY...LONG TERM STARTS DRY WITH ABOVE NORMAL TEMPS ON FRIDAY...BUT PLENTY OF UNCERTAINTY DEVELOPS OVER THE WEEKEND INTO EARLY NEXT WEEK WITH REGARDS TO MAGNITUDE OF TROF AND ASSOCIATED CAA. FOR FRIDAY...MID/UPPER RIDGE AND SFC HIGH PRES OVERHEAD WL RESULT IN MAINLY CLR SKIES WITH TEMPS IN THE 50S MTNS TO 60S VALLEYS. HAVE NOTED THE 12Z ECWMF IS MUCH WARMER WITH PROGGED 85H TEMPS BTWN 5-7C...WHICH COULD SUPPORT A FEW L70S. FOR SAT INTO SUNDAY...POTENT 5H VORT RACES ACRS THE GREAT LAKES INTO THE NE CONUS...WITH SECONDARY ENERGY DROPPING ON BACKSIDE HELPING TO DEVELOP A CLOSED 5H/7H CIRCULATION. THE TIMING OF THIS ENERGY INTERACTING WITH MAIN TROF WL HAVE A HUGE IMPACT ON OUR TEMPS/WEATHER OVER THE WEEKEND. CRNT GFS/ECMWF HAVE FLIP FLOPPED AGAIN ON THE OVERALL PATTERN...WITH GFS SUPPORTING A COOLER/WETTER SOLUTION WITH SOME WHITE IN THE MTNS...WHILE THE LATEST 12Z ECMWF IS MUCH LESS AMPLIFIED AND WARMER/DRIER. GIVEN THE UNCERTAINTY ON DEPTH OF TROF AND AMOUNT OF LLVL CAA BEHIND SFC BOUNDARY...WL MENTION TEMPS NEAR NORMAL ON SATURDAY WITH SHOWERS LIKELY AND BLW NORMAL ON SUNDAY WITH CHC SHOWERS MAINLY OVER THE MTNS. PROGGED 85H TEMPS RANGE BTWN 0-2C ON SAT...RESULTING IN HIGHS 40S MTNS TO 50S VALLEYS WITH LOWS IN THE 30S MTNS TO 40S VALLEYS ON SAT NIGHT. MUCH COOLER AIR ARRIVES SUNDAY WITH PROGGED 85H TEMPS BTWN -5C AND -7C AND 1000 TO 500MB THICKNESS VALUES BTWN 530 AND 534...SUPPORTING HIGHS MAINLY IN THE 30S MTNS TO 40S TO NEAR 50F VALLEYS. THESE PROFILES SUPPORT THE POTENTIAL FOR MTNS SNOW SHOWERS AT NIGHT...ESPECIALLY SAT NIGHT/SUNDAY NIGHT WITH MAINLY RAIN IN THE VALLEYS...DUE TO WARM BL TEMPS. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... THROUGH 00Z THURSDAY...SFC LOW NORTH OF LAKE CHAMPLAIN WITH FRONTAL OCCLUSION EXTENDING BACK ACROSS NEW YORK AND ONTARIO RESULTING IN WIDESPREAD MVFR TO IFR CEILINGS ACROSS NORTHERN NEW YORK THIS EVENING. AHEAD OF A SFC COLD FRONT EXTENDING DOWN THE CHAMPLAIN VALLEY...4-6SM -RA NOTED APPROACHING MPV. SFC LOW AND ASSOCIATED FRONTS WILL MOVE EASTWARD WITH VFR CEILINGS GRADUALLY GOING DOWN TO MVFR/IFR CEILINGS WITH PERIODS MVFR VISIBILITY IN RAIN...DRIZZLE...AND/OR MIST. THIS LINE OF THINKING IS SUPPORTED BY BOTH UPSTREAM OBSERVATIONS AND 21Z RAP BUFKIT SOUNDINGS. EXPECT MVFR TO IFR STRATUS/STRATOCUMULUS TO LINGER INTO THE MORNING HOURS. WINDS TO BECOME NORTHWEST 8-10 KTS WITH PASSAGE OF SFC LOW. EXPECT A CONTINUATION AT LEAST MVFR STRATOCUMULUS TO LINGER THROUGH THE DAY WEDNESDAY AS UPPER SHORTWAVE TROUGH DIGS INTO THE NORTH COUNTRY AND MAINTAINS PLENTY OF LOW- LEVEL MOISTURE AROUND. EXPECT SOME OF THIS MOISTURE TO FALL AS UPSLOPE RAIN/SNOW SHOWERS WITH POSSIBLE MVFR TO IFR VISIBILITY AT SLK AND MPV WITH VFR VISIBILITIES ELSEWHERE. NORTHWEST WINDS REMAIN AT OR AROUND 10 KTS. SOME QUESTION AS TO HOW MUCH MIXING CAN TAKE PLACE WEDNESDAY BUT ANY BREAKS IN OVC/BETTER MIXING COULD PRODUCE OCCASIONAL GUSTS TO 20 KTS. OUTLOOK 00Z THURSDAY THROUGH SATURDAY...COOLER AND UNSETTLED WX CONDITIONS CONTINUE INTO WEDS NIGHT WITH RAIN/SNOW SHOWERS LIKELY...AND SOME PERIODS OF MVFR/IFR CONDITIONS POSSIBLE AT KSLK/KMPV IN THE HEAVIER SNOW SHOWER ACTIVITY...ESPECIALLY AT NIGHT. SFC HIGH PRES AND VFR CONDITIONS RETURN FOR THURS INTO FRIDAY. CLOUDS INCREASE LATE FRIDAY WITH RAIN ARRIVING FRIDAY NIGHT INTO SATURDAY. MAINLY VFR CONDITIONS INITIALLY ON FRIDAY NIGHT...BUT MVFR WITH OCCASIONAL IFR POSSIBLE ON SATURDAY IN THE HEAVIER AREAS OF PRECIP. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JN NEAR TERM...RJS/KGM SHORT TERM...JN LONG TERM...TABER AVIATION...TABER/LOCONTO
AREA FORECAST DISCUSSION
NWS BISMARCK ND
444 AM CDT WED APR 23 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 444 AM CDT WED APR 23 2014 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CONTINUED GUSTY WINDS THIS MORNING AND AFTERNOON...PRECIPITATION CHANCES AND AMOUNTS TODAY AND TONIGHT...AND THUNDERSTORM CHANCES (NON- SEVERE) MOST LOCATIONS. CURRENTLY...UPPER LEVEL TROUGH EXTENDING FROM THE PACIFIC NORTHWEST SOUTHEAST INTO THE DESERT SOUTHWEST BECOMING NEGATIVELY TILTED AND SLOWLY MOVING EAST TOWARDS THE ROCKIES. POTENT EMBEDDED S/WV LIFTING NORTHEAST ACROSS WYOMING. SFC TROUGH CURRENTLY EXTENDS ACROSS THE HIGH PLAINS APPROACHING THE WESTERN DAKOTAS. MOISTURE TRANSPORT RABID THE PAST SEVERAL HOURS WITH A 60KT LOW LEVEL JET HELPING TO INCREASE PWATS FROM AROUND A QUARTER OF AN INCH LAST EVENING UP TO 0.75"-1.00" NOW. FORCING STRONG WITH STEEP THERMAL UPGLIDE EAST OF THE SFC TROUGH ALONG WITH INCREASING UPPER LEVEL DIVERGENCE AS A JET STREAK LIFTS NORTH-NORTHEAST FROM THE CENTRAL ROCKIES TOWARDS THE NORTHERN PLAINS. WIDESPREAD SHOWERS ACROSS THE SOUTHERN HALF OF ND LIFTING NORTH WITH CONTINUED DEVELOPMENT ACROSS NORTHERN SOUTH DAKOTA. EXPANDED SLIGHT CHANCE OF THUNDERSTORMS TO INCLUDE MUCH OF THE WEST AND CENTRAL THIS MORNING. HAVE ALREADY HAD SEVERAL LIGHTNING STRIKES SOUTHWEST WITH A FEW MORE JUST WEST OF WILLISTON OVER NORTHEAST MONTANA. MESOANALYSIS DEPICTS STEEP MID LEVEL LAPSE RATES (10C/KM) OVER THESE AREAS...WITH THE LATEST FEW RUNS OF THE RAP ALSO INDICATING 100-300 CAPE WEST. NEAR TERM HIGH RES MODELS SHOW THIS PLUME OF FAVORABLE MID LEVEL LAPSE RATES AND WEAK CAPE EXPANDING NORTH AND EAST WITH TIME THIS MORNING IN ADDITION TO CONTINUED STRONG FORCING. NOTHING SIGNIFICANT EXPECTED BUT WANTED TO MAKE SURE THUNDERSTORMS WERE IN THE FORECAST THROUGH THE AM. THE MAIN PRECIPITATION BAND IS STILL FORECAST TO LIFT NORTH AND EAST TODAY AS THE SURFACE TROUGH AXIS LIFTS NORTHEAST ACROSS THE STATE. MARGINAL CONVECTIVE PARAMETERS REMAIN OVER THE JAMES RIVER VALLEY THIS AFTERNOON/EARLY EVENING...SO WILL KEEP A MENTION OF SLIGHT CH. OF THUNDERSTORMS THERE...CONSISTENT WITH THE SPC DAY 2 OUTLOOK. PRECIPITATION CHANCES DECREASE OVERNIGHT 06-12Z AS ALL OF WEST AND CENTRAL ND BECOMES DRY SLOTTED. WILL ISSUE A WIND ADVISORY THIS MORNING THROUGH EARLY TO MID AFTERNOON ACROSS THE CENTRAL AND EAST WITH BUFKIT INDICATING 30 TO NEAR 35 KTS OF SUSTAINED WINDS AS THE MIXING HEIGHT ELEVATES AFTER DAYBREAK. OPTED TO START IT NOW AS HAVE ALREADY HAD GUSTS IN EXCESS OF 40 MPH ASSOCIATED WITH THE ONGOING SHOWERS AS THEY MIX SOME OF THE LLJ WINDS TO THE SURFACE. WINDS WILL TAPER OFF WEST TO EAST LATER THIS MORNING INTO THE AFTERNOON AS THE SFC TROUGH ADVANCES EAST. ON THE BACKSIDE OF THE TROUGH...WESTERLY WIND GUSTS TO 40 MPH ARE FORECAST ACROSS THE HIGHER TERRAIN OF THE SOUTHWEST TO DEVELOP THIS AFTERNOON...SO WENT WITH A WIND ADV. THERE AS WELL. FIRE DANGER WILL BE ELEVATED SOUTHWEST DUE TO THE STRONG WINDS AND DECREASING HUMIDITY. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 444 AM CDT WED APR 23 2014 A CLOSED UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN ON THURSDAY WILL MOVE EAST ALONG THE INTERNATIONAL BORDER THROUGH FRIDAY BRINGING SCATTERED SHOWERS TO MAINLY THE FAR NORTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. THE GFS IS THE FARTHEST SOUTH WITH THE TRACK OF THE UPPER LOW...THUS BRINGS THE CHANCE OF PRECIPITATION FARTHER SOUTH ON THURSDAY. USED A COMPROMISE HERE KEEPING THE FAR SOUTHWEST AND SOUTH CENTRAL DRY...AND A BAND OF SLIGHT CHANCE POPS FROM THE WEST CENTRAL INTO THE JAMES RIVER VALLEY...AND HIGHER CHANCE POPS ALONG THE NORTH. DUE TO THE PROXIMITY OF THE UPPER LOW...WILL KEEP A MENTION OF THUNDER ACROSS THE FAR NORTH THURSDAY AFTERNOON. ALSO KEPT A MENTION OF LINGERING RAIN/SNOW SHOWERS ACROSS THE FAR NORTH AND EAST THURSDAY NIGHT AND FRIDAY AS THE UPPER TROUGH LINGERS HERE THROUGH FRIDAY. INDICATIONS ARE THAT WE ARE IN FOR A WET PERIOD OVER THE WEEKEND AND INTO EARLY NEXT WEEK. DETERMINISTIC MODELS ARE IN BETTER AGREEMENT IN CLOSING OFF A STRONG UPPER LEVEL LOW OVER THE CENTRAL/SOUTHERN PLAINS. AN INITIAL WAVE LIFTS THROUGH THE AREA ON SATURDAY WITH THE BRUNT OF THE PRECIPITATION ARRIVING SUNDAY AND CONTINUING THROUGH MONDAY. ONE SIGNIFICANT DIFFERENCE BETWEEN THE GFS COMPARED TO THE ECMWF/GEM IS THE ORIENTATION OF THE DOWNSTREAM BLOCKING RIDGE. A GFS SOLUTION KEEPS A SHARPER RIDGE AHEAD OF THE LOW THUS SOUTHERLY FLOW REMAINS OVER THE AREA UNTIL LATE MONDAY. THEREFORE PRECIPITATION WOULD FALL AS ALL RAIN. A ECMWF /GEM SOLUTION DEPICTS A COLDER EAST TO NORTHEAST FLOW THROUGH THE ENTIRE EVENT. THUS A BETTER CHANCE OF MIXED RAIN AND SNOW OR ALL SNOW...ESPECIALLY DURING THE OVERNIGHT AND EARLY MORNING HOURS SUNDAY THROUGH MONDAY. WE DRY OUT TUESDAY AND WEDNESDAY BUT REMAIN COOL BEHIND THE EXITING LOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 444 AM CDT WED APR 23 2014 WINDY CONDITIONS WILL CONTINUE WITH A SOUTHEAST WIND GUSTING OVER 30 KTS AT TIMES. WINDS WILL SUBSIDE FROM WEST TO EAST LATER THIS MORNING AND AFTERNOON. HOWEVER...A GUSTY WESTERLY WIND WILL DEVELOP ACROSS WESTERN NORTH DAKOTA AFTER 18Z THROUGH THE AFTERNOON. SHOWERS AND A SLIGHT CHANCE FOR THUNDERSTORMS WILL CONTINUE THIS MORNING...WITH ADDITIONAL SHOWERS WEDNESDAY AFTERNOON/EVENING. CIGS/VIS GENERALLY VFR...BUT CANNOT RULE OUT PERIODS OF MVFR CIGS/VIS IN ANY HEAVIER SHOWER. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 1 PM CDT /NOON MDT/ THIS AFTERNOON FOR NDZ003-011-020>022-034>036-042-045>047-050. WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR NDZ004-005-012- 013-023-025-037-048-051. WIND ADVISORY FROM NOON TODAY TO 6 PM MDT THIS EVENING FOR NDZ040-041-043-044. && $$ SHORT TERM...NH LONG TERM...TWH AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
158 AM CDT WED APR 23 2014 .UPDATE... ISSUED AT 158 AM CDT WED APR 23 2014 UPDATED POPS BASED ON LATEST MODEL DATA AND RADAR IMAGERY...TRYING TO FINE TUNE THE NEAR TERM BETWEEN NOW AND 12Z. SLIGHTLY EXPANDED THE THUNDERSTORM MENTION...BUT LARGELY KEPT IT CONFINED TO THE SOUTHWEST ADDING THE FAR SOUTH CENTRAL BASED ON LATEST NAM/RAP MID LEVEL LAPSE RATES. REMAINDER OF THE FORECAST REMAINS ON TRACK. UPDATE ISSUED AT 934 PM CDT TUE APR 22 2014 LATE EVENING UPDATE MAINLY FOR POP/WEATHER TRENDS OVERNIGHT. BASED IN PART OF THE 23/01Z RAP AND THE 23/00Z NAM...HAVE SLOWED THE NORTHWARD PROGRESSION OF THE SHOWERS SLIGHTLY OVERNIGHT AND BOOSTED POPS SOMEWHAT IN THE SOUTHWEST. ALSO FOLLOWED THE RAP SHOWALTER INDEX PROGS TO TRIM BACK THE ISOLATED THUNDER OVERNIGHT INTO THE FAR SOUTHWEST. SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE WEDNESDAY...ESPECIALLY ACROSS THE NORTHEAST HALF OF THE FORECAST AREA. UPDATE ISSUED AT 629 PM CDT TUE APR 22 2014 NO SIGNIFICANT CHANGES FOR EARLY EVENING UPDATE. SHOWERS EXPECTED TO DEVELOP BY LATE EVENING THEN SPREAD NORTH OVERNIGHT. AN ISOLATED RUMBLE OF THUNDER IS NOT OUT OF THE QUESTION FAR WEST OVERNIGHT. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 335 PM CDT TUE APR 22 2014 GUSTY SOUTHEASTERLY WINDS WILL CONTINUE ACROSS WESTERN AND CENTRAL NORTH DAKOTA LATER THIS AFTERNOON AND OVERNIGHT. THE MODELS HAVE BEEN PERFORMING POORLY WITH RESPECT TO AFTERNOON DEWPOINTS (TOO HIGH). AS A RESULT...MANUALLY ADJUSTED THE AFTERNOON DEWPOINTS DOWN BASED ON THE CURRENT OBS/TRENDS. THE COMBINATION OF HIGH WINDS AND LOW RELATIVE HUMIDITIES CONTINUE TO GENERATE A VERY HIGH FIRE DANGER OVER WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON. DEWPOINT RECOVERY SHOULD BEGIN IN EARNEST AFTER SUNSET AS LOW-LEVEL MOISTURE GETS DRAWN UP OVER THE STATE AHEAD OF AN APPROACHING LONGWAVE TROUGH. THE MEDIUM RANGE MODELS PROG THAT LIGHT RAIN SHOWERS WILL BECOME LIKELY AFTER MIDNIGHT AHEAD OF THE AFOREMENTIONED APPROACHING LONGWAVE TROUGH. THE MAIN BAND OF WARM AIR ADVECTION/CONVEYOR BELT PRECIPITATION IS EXPECTED TO DEVELOP FROM THE JAMES RIVER BASIN AND EXTEND NORTHWEST INTO MINOT AND NORTHWESTERN NORTH DAKOTA. FURTHERMORE...MARGINAL MID-LEVEL LAPSE RATES COMBINED WITH INCREASING UPPER LEVEL FORCING COULD GENERATE A SLIGHT CHANCE FOR THUNDERSTORMS WEST AFTER MIDNIGHT. HOWEVER...NO ORGANIZED SEVERE WEATHER IS EXPECTED. BY WEDNESDAY...THE MAIN PRECIPITATION BAND IS FORECAST TO LIFT NORTHEAST AS THE ATTENDANT SURFACE TROUGH AXIS LIFTS NORTHEAST ACROSS THE STATE. AGAIN...MARGINAL CONVECTIVE PARAMETERS WARRANT AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS MENTION OVER CENTRAL AND EASTERN NORTH DAKOTA...MAINLY ALONG THE BOUNDARY AS IT PUSHES ACROSS THE STATE. THIS IS CONSISTENT WITH THE SPC DAY 2 OUTLOOK. MARGINAL WIND ADVISORY CRITERIA MAY DEVELOP OVER SOUTHWESTERN NORTH DAKOTA WEDNESDAY AFTERNOON. WILL HOLD OFF ON ISSUING ANY WIND HEADLINES FOR THIS UPDATE AND WILL LET LATER SHIFTS DECIDE. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 335 PM CDT TUE APR 22 2014 TWO VIGOROUS SYSTEMS WILL INFLUENCE THE WEATHER ACROSS WESTERN AND CENTRAL NORTH DAKOTA IN THE LONG TERM PERIOD. SYSTEM 1... A WAVE MOVING ACROSS THE NORTHWEST U.S. AND SOUTHWEST CANADA IS EXPECTED TO DEVELOP A CLOSED UPPER LEVEL CIRCULATION OVER SOUTHERN BRITISH COLUMBIA/ALBERTA ON WEDNESDAY AND TRACK SLOWLY EAST ALONG THE INTERNATIONAL BORDER THROUGH FRIDAY. A SURFACE WARM FRONT IS FORECAST TO BE NEAR THE DEVILS LAKE AND JAMES RIVER BASIN BY WEDNESDAY EVENING...WITH SOUTHEAST WINDS AHEAD OF THE WARM FRONT AND WEST WINDS BEHIND IT. SCATTERED TO NUMEROUS SHOWERS DURING THE DAY WEDNESDAY SHOULD BE MAKING THEIR WAY ALONG AND AHEAD OF THE WARM FRONT...WITH A DRY SLOT BEHIND IT OVER SOUTHWESTERN NORTH DAKOTA. THUS EXPECTING EVENING SCATTERED SHOWERS NORTH THROUGH THE JAMES RIVER VALLEY...WITH MAINLY SLIGHT CHANCES OF SHOWERS AFTER MIDNIGHT. ON THURSDAY MORNING A SURFACE LOW ALONG THE NORTHERN BRANCH OF THE WARM FRONT IS FORECAST TO BE SITUATED OVER SOUTHERN SASKATCHEWAN. THIS LOW IS FORECAST TO MOVE SOUTHEAST ACROSS NORTH DAKOTA ON THURSDAY...WITH A BAROCLINIC ZONE/BOUNDARY SETTING UP NORTHWEST-TO-SOUTHEAST ACROSS THE STATE THURSDAY NIGHT. THIS SCENARIO WILL BRING A CHANCE OF SHOWERS - BETTER CHANCES NORTH - WITH THUNDERSTORMS POSSIBLE THURSDAY AFTERNOON. LATE THURSDAY NIGHT AND FRIDAY A COLD FRONT MOVES SOUTH ACROSS THE STATE...BRINGING A CHANCE OF RAIN OR SNOW SHOWERS - MAINLY NORTH IN THE TURTLE MOUNTAINS...BUT WITH LITTLE OR NO SNOW ACCUMULATIONS. SYSTEM 2... DURING THIS TIME THE NEXT STRONG SYSTEM IS TAKING SHAPE OVER THE WESTERN U.S. MODEL UNCERTAINTY INCREASES AS WE HEAD INTO THE WEEKEND BUT IT APPEARS THAT THE UPPER LEVEL FLOW IS TRENDING SLOWER WITH A BLOCKING PATTERN SETTING UP OVER THE CENTRAL PORTION OF THE COUNTRY. THIS BLOCK MAINLY KEEPS A COLD HIGH PRESSURE SYSTEM OVER HUDSON BAY WHILE A LARGE UPPER LEVEL LOW DEVELOPS ACROSS THE US ROCKIES AND CLOSES OFF SOMEWHERE IN THE WESTERN/CENTRAL/SOUTHERN PLAINS. WILL NEED TO KEEP AN EYE ON THE EVOLUTION OF THIS SYSTEM AS LATEST DETERMINISTIC RUNS ARE COLDER AND WETTER ACROSS WESTERN AND CENTRAL NORTH DAKOTA. UTILIZED A STRAIGHT MODEL BLEND FOR THE EXTENDED AND THIS IS DEPICTING PRECIPITATION ACROSS MAINLY THE SOUTHWEST ON SATURDAY...THEN SPREADING ACROSS MOST OF THE AREA SUNDAY THROUGH MONDAY. WITH COLDER TEMPERATURES EXPECTED BY THE WEEKEND PRECIPITATION CHANCES WERE MAINLY RAIN DURING THE AFTERNOON AND EARLY EVENING...WITH A MIX OF RAIN AND SNOW DURING THE OVERNIGHT AND EARLY MORNING HOURS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 158 AM CDT WED APR 23 2014 BREEZY CONDITIONS WILL CONTINUE OVERNIGHT INTO WEDNESDAY WITH A SOUTHEAST WIND GUSTING OVER 20 KTS. SHOWERS DEVELOPING SOUTH TO NORTH BETWEEN 06Z AND 09Z AND CONTINUE PAST DAYBREAK...FOLLOWED BY A LATE MORNING LULL AND ADDITIONAL SHOWERS WEDNESDAY AFTERNOON/EVENING. WINDS WILL SHIFT FROM SOUTHEAST TO MORE WESTERLY LATER IN THE DAY WEDNESDAY AND WEDNESDAY NIGHT AS A FRONTAL BOUNDARY PUSHES EAST ACROSS THE STATE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH SHORT TERM...TM LONG TERM...JV AVIATION...NH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
305 AM EDT WED APR 23 2014 .SYNOPSIS... HIGH PRESSURE AND COOLER WEDNESDAY. DRY WARM FRONT THURSDAY. A WEAK COLD FRONT CROSSES THE AREA FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... NORTHWEST FLOW CREATING A STRATUS DECK OVER THE NORTHERN COUNTIES THIS MORNING. MODELS HANDLE THIS MOISTURE CONSIDERABLY DIFFERENTLY TODAY WHEN MIXING STARTS OCCURRING. RUC SHOWS IT QUICKLY MIXING OUT WHILE THE NAM AND GFS HOLD ONTO CUMULUS WELL INTO CENTRAL WV. WENT MORE TOWARD THE RUC FOR NOW...BUT CONFIDENCE IS LOW. WITH A NORTHWEST FLOW CONTINUING TODAY...WENT TOWARD THE COOLER MOS GUIDANCE FOR HIGHS. WINDS SHOULD DECOUPLE TONIGHT...ALLOWING FOR SOME GOOD RADIATION. BIG QUESTION IS HOW QUICKLY CLOUDS FROM THE WARM FRONT PUSH INTO THE AREA. THIS BECOMES EXTRA IMPORTANT DUE TO THE POSSIBILITY OF FREEZING TEMPERATURES IF THERE IS ENOUGH CLOUD FREE TIME AFTER WINDS LAY DOWN. WILL GO WITH A FREEZE WATCH ACROSS THE NORTHERN COUNTIES WHERE COLDEST TEMPERATURES ARE EXPECTED...BUT OUTLYING AREAS JUST SOUTH OF THE FREEZE WATCH ARE NOT NECESSARILY SAFE...DEPENDING ON CLOUD TIMING. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... MODELS IN GENERAL AGREEMENT THIS PERIOD. HIGH PRESSURE WILL BE LOCATED OVER THE AREA EARLY THURSDAY. HOWEVER...HIGH WILL SLIDE EAST...ALLOWING A WARM FRONT TO DEVELOP/PUSH INTO THE AREA BY THURSDAY AFTERNOON. THIS FRONT WILL PUSH NORTH THURSDAY NIGHT. LATEST GUIDANCE ACTUALLY INDICATES AIRMASS WILL BE DRIER THAN OUR PREVIOUS FORECAST INDICATED. APPEARS THIS IS THE RESULT OF A SLOWER MOVEMENT OF THE WARM FRONT. HAVE TWEAKED DEWPOINTS DOWN QUITE A BIT...ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE REGION. WITH AIRMASS REMAINING DRY INVOF THIS FEATURE...ONLY EXPECT AN INCREASE IN CLOUDS. A COLD FRONT IS THEN PROGGED TO PUSH EAST ACROSS THE REGION LATE THURSDAY NIGHT INTO FRIDAY. LATEST GUIDANCE IS A LITTLE SLOWER WITH THE FRONT...AND HAVE TWEAKED POP AND WEATHER GRIDS TO REFLECT THIS TREND. NOT MUCH...IF ANY...INSTABILITY ALONG/AHEAD OF FRONT. BUT NAM DOES SHOW A LITTLE. WITH PREVIOUS FORECAST INDICATING SLIGHT CHANCE THUNDER...HAVE DECIDED TO KEEP IT IN PLACE. WEAK HIGH PRESSURE SHOULD NOSE IN FROM THE SOUTHWEST FRIDAY AFTERNOON...BRINGING PRECIP CHANCES TO END. MODELS HAVE BEEN CONSISTENT PUSHING A WEAK COLD FRONT SOUTHEAST LATE FRIDAY NIGHT INTO SATURDAY. HAVE MAINTAINED LOW POPS WITH THIS FEATURE. LATEST MAV NUMBERS FOR HIGHS ON THURSDAY WERE CLOSE TO PREVIOUS FORECAST NUMBERS...WITH THE MET NUMBERS LOWER. MET NUMBERS APPEAR TO BE ON THE COOL SIDE...SO HAVE LEANED TOWARDS THE MAV NUMBERS. STILL NOT SURE ABOUT LOWS THURSDAY NIGHT. WITH SOUTHERLY WINDS AND INCREASING LOW-LEVEL MOISTURE...EXPECT TEMPS WILL REMAIN UP AND HAVE AGAIN LEANED TOWARD MAV NUMBERS. BUT WOULD NOT BE TOO SURPRISED TO SEE LOWS SLIP BELOW OUR FORECASTED VALUES. CURRENT THINKING IS THAT MAV NUMBERS ALSO LOOK BEST FOR HIGHS ON FRIDAY...AS LITTLE IN THE WAY OF COOLING IS INDICATED BEHIND THE FRONT. MEX NUMBERS WERE USED TO TWEAK PREVIOUS NUMBERS FOR LOWS FRIDAY NIGHT AND HIGHS ON SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... THE FRONT COULD STALL SOUTH OF THE AREA DURING THE WEEKEND BEFORE LIFTING NORTH AS A WARM FRONT SUNDAY AND MONDAY FOR ADDITIONAL PCPN MAINLY EXTREME SOUTHERN WV. USED HPC GUIDE FOR TEMPERATURES AND DEWPOINTS WITH FEW TWEAKS DOWN ON HIGHS THROUGH THE PERIODS. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... A STRATUS DECK OVER NORTHEASTERN WV...SCATTERING WESTWARD ACROSS NORTHERN WV AND EAST CENTRAL OHIO...MAY CAUSE SOME MVFR CONDITIONS THIS MORNING. THIS DECK SHOULD TURN INTO A CUMULUS DECK AND DISSIPATE TODAY AS THE SUN MIXES THE ATMOSPHERE. VFR CONDITIONS CAN THEN BE EXPECTED. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY... FORECAST CONFIDENCE: HIGH. ALTERNATE SCENARIOS: EXTENT OF THE STRATUS DECK IN THE NORTH COULD VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE WED 04/23/14 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H L H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z THURSDAY... NO IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR WVZ008>011-016>020-027>032. OH...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR OHZ066-067-075-076-085. KY...NONE. VA...NONE. && $$ SYNOPSIS...JSH/RPY NEAR TERM...RPY SHORT TERM...JSH LONG TERM...ARJ AVIATION...RPY Area Forecast Discussion National Weather Service Spokane WA 254 AM PDT WED APR 23 2014 .SYNOPSIS... Occasional precipitation chances, breezy conditions and relatively cool temperatures dominate the weather pattern. Passing rain and snow chances Wednesday are followed by steadier rain chances late Wednesday night into Thursday, followed by a threat of more scattered showers, and perhaps some thunder, Thursday afternoon. Showers will remain a threat into the weekend, before a relative lull comes for the start of the new work week. && .DISCUSSION... Today and tonight: A threat of rain and snow showers returns to the Inland NW today, while steadier rain develops late tonight. This morning a tight 500mb shortwave was entering the Cascades, with weak 850-700mb theta-e ridge leading it into central and eastern WA and north ID. That latter feature will provide focus for the moisture and increasing precipitation across the Cascade crest and the Okanogan to Upper Columbia Basin, spreading into the eastern third of WA and north ID this morning. There is some disagreement in how quickly precipitation develops or how widespread it will actually be. The HRRR actually shows very little in that way of significant precipitation; however the GFS/NAM/EC/SREF are more generous. At 930Z clouds were starting to thicken near the Cascades and expand east, while a few light radar returns were developing east of Othello. I don`t see any evidence that anything is actually reaching the ground at this time, but leaning toward the more dominant model solutions suggest this will change. So I gradually increase PoPs to likely through the morning, especially across southeast WA to the central Panhandle. For late this morning to early afternoon the 500mb shortwave comes on the heels of the 850/700mb wave, before shifting into Montana in the late afternoon. With 500mb temperatures in the core of this disturbance in the -25 to -31 C range and a swath of 100-200 J/kg of CAPE and marginally negative LI values, this will mean a continued shower threat across the eastern third of of WA and north ID this afternoon, before dissipating in coverage by early evening. I included a slight chance of thunder toward the northeast mountains, but even then I think any thunder that develops would be more isolated in nature, if any develops at all. Looking at current wet-bulb zero heights and regional temperatures, the precipitation will have a modest opportunity to fall as snow across a large portion of the region, save for the lower Palouse to the deeper Columbia Basin and the L-C valley. The threat for more than an inch of snow, however, will remains toward the Cascades and the Panhandle Mountains, and perhaps toward the higher Idaho Palouse. The threat for accumulating snow outside of the mountains will also be limited to early in the day. However the convective or unstable nature of the atmosphere under the trough will mean the potential for a rain/snow/graupel/small hail mix with any showers that occur into the afternoon. Late tonight into Thursday morning a warm front comes in from the southwest. This will shift the region to more stable regime. Strengthening isentropic ascent and subtropical moisture plume come the warm front as the night wares on. PWATs rise to between 0.50 to 0.75 inches (or ~150-200% of normal). This favors another swath of precipitation, enveloping much of the region from the Columbia Basin toward the northern mountains between 04Z-11Z (or ~9 PM to 4 AM). I increased precipitation chances to likely for a large portion of the region going past 06Z. By this time the milder air surges in, pushing wet-bulb zero heights and snow levels up toward 3500-4000 feet around the mountains of northeast WA and north ID and to around 4500 to 5500 feet elsewhere. In other words the next system looks to be more of a valley rain and high mountain snow event. /J. Cote` Thursday through Friday...Chances are very good that the recent spurt of wet weather will continue through this period as well. The latest water vapor and shows a developing baroclinic band near 150w with a nice tap into sub-tropical moisture per the blended precipitable water product. Models in very good agreement that this atmospheric river will slide into SW Washington Wednesday night and gradually spread northeast through Thursday morning in the form of a warm front. Precipitation will likely impact most locations...including the lee of the Cascades due to moderate isentropic ascent resultant of the mid-level southwest winds. Most of the stratiform precipitation will fall in the morning...as the atmospheric river is expected to shift east of the region by afternoon. Before it shifts east most of the region will see measurable rainfall with amounts ranging from .20 to .40 inches over most valley locations...with heavier amounts over the mountains of north Idaho and the Cascade Crest. This bout of rain will be followed by a weak negatively tilted trough during the afternoon...somewhat similar to yesterday. Whether or not the moisture from the morning rain can combine with afternoon heating to produce deep convection and possible thunderstorms is the question. Yesterdays window of opportunity was too short to tap into the moisture and thus we never saw thunderstorms. The Thursday setup isn`t ideal but it should be a little better than what we saw. Thus we will continue to mention a chance of afternoon and early evening thunderstorms. The best chances will occur east of a line from Republic to Ritzville. Model instability isn`t supportive of any strong convection as the CAPE values are too low for strong updrafts. The threat of thunder will wane Thursday evening...and most of the area will see a brief drying trend...with one exception. The upper level trough responsible delivering the atmospheric river will shift onto the Washington coast by morning...which is expected to send a shortwave trough in from the southwest. All the models are showing a similar scenario...with the track of the shortwave expected to impact the southeast corner of Washington into NC Idaho...due to the proximity of a low-level theta-e ridge axis. Moderate rainfall amounts will be possible in this region with locations such as Lewiston...Pullman...and the Silver Valley seeing the possibility of up to a quarter inch. Across the remainder of the forecast area the possibility of significant rainfall is considerably lower. That notion will likely continue until afternoon at which time the upper level trough will likely shift into the Cascades. This should result in diurnally developing convection...however lapse rates aren`t really all that impressive. Most of the convection will likely fire over the mountains due to terrain forcing. Friday night through Monday...The upper level trough or some semblances of it will likely remain fixed over the Pacific Northwest through this period as well. There are no signs of seeing a good fetch of moisture...or strong synoptic forcing at least through the weekend. So we are primarily looking at an unsettled weather pattern with generally dirunally driven shower activity. Most of the convection will fire near the Cascades and the Idaho Panhandle. By Monday there is some support for a weak shortwave ridge. This should lead to slightly drier weather but based on the amplitude of the ridge...we don`t want to go completely dry. fx Monday Night through Wednesday: The extended part of the forecast which yesterday featured an amplifying ridge, now has gained some uncertainty. Most recent GFS model runs now have the ridge sliding further to the east over MT allowing the offshore trough to advect an abundance of subtropical moisture into our region leading to increased chances for more precipitation. While the GFS has trended wetter, the Euro still advertises the ridge remaining entrenched right over our area keeping the storm track to the west. This would lead to the dry conditions the models were showing yesterday. Due to the model uncertainty I did increase POPs slightly to include the mention of showers for higher elevation locations along with the eastern third of WA and the Panhandle. Confidence is not high with this change, but thought it would be worthwhile to at least move POPs towards climo for the time being. Other than POPs, not many changes were made to the period due to lower confidence. Many factors for this portion of the forecast will depend on the verifying model and will have to be fine tuned once model agreement is better. Given the models right now, the active GFS would bring continued wet conditions with below normal temps while Euro would bring above normal temps and drier conditions. For the time being we will just have to wait and see how the models trend over the next few runs. /Fliehman && .AVIATION... 06Z TAFS: An upper-level trof is currently anchored over the region. There is a break in the precipitation at this time but clouds/showers will begin crossing the Cascades btwn 6z- 9z...spreading toward the ID/WA border 13-15z. The heaviest pcpn with this feature looks to focus across SE WA and the lower ID Panhandle. Snow will be possible down to 2000` but most accumulations will focus at elevations of 2500-3000` and higher. Showers will carry the potential for MVFR cigs and any intense snow shower could brielfy lead to IFR conditions. Any snow should have a hard time accumulating on area runways. Snow levels will rise above all terminals aft 17z with breezy winds and sct -shra through 23z. A small break arnd 00z will be followed by lower cigs and incr -ra chances aft 03z as another moist warm front lifts into the region. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 51 39 55 38 54 37 / 80 70 100 40 40 20 Coeur d`Alene 50 38 53 37 53 37 / 80 60 100 70 50 20 Pullman 50 41 54 39 50 37 / 80 70 100 50 50 20 Lewiston 56 45 60 44 55 42 / 60 50 100 60 70 20 Colville 57 35 59 35 61 36 / 50 50 100 60 40 20 Sandpoint 49 36 51 36 54 37 / 70 50 100 80 50 30 Kellogg 45 36 50 36 52 36 / 80 60 100 70 70 40 Moses Lake 61 44 65 40 61 38 / 20 70 70 10 10 20 Wenatchee 60 45 64 43 61 41 / 20 60 70 10 10 20 Omak 59 39 62 36 62 35 / 20 50 80 10 20 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
609 AM CDT Wed Apr 23 2014 ...AVIATION UPDATE... .SHORT TERM...(Today and Tonight) Issued at 341 AM CDT WED APR 23 2014 08Z water vapor shows a longwave trough moving into the Rockies with a mid level ridge axis over the Great Plains. At the surface, obs shows ridging along the upper and middle MS river valley with a lee trough over WY and CO deepening. Radar shows scattered shower activity gradually expanding in coverage over the past couple hours. The RAP and NAM show isentropic upglide on the 305K surface, which seems to line up with where the elevated showers are developing, persisting into the early afternoon. With the HRRR, RAP and NAM all showing this scattered activity going on through the morning, have increased pops and will include coverage wording in the forecast. Forecast soundings show little if any instability for this activity to work with so would anticipate thunder to remain relatively isolated this morning. Meanwhile the models continue to show some surface based instability developing this afternoon across north central KS ahead of a Pacific cold front. As the upper shortwave moves out across the plains, thunderstorms are expected to develop along this boundary. This activity is expected to quickly evolve into a linear system and move across the forecast area overnight. Initially there may be some hail and damaging wind threat as the line begins moving into north central KS. And there remains a large amount of low level bulk shear progged by the NAM. But the NAM also develops quite a lot of CIN suggesting the line of storms may be driven more by the front and not necessarily persisting on instability ahead of the boundary. So the expectation is that storm intensity will diminish as the storms move into eastern KS. In any case, good forcing from the shortwave and steep mid level lapse rates should be good enough for much of not all of the forecast to see rain overnight and will maintain categorical POPs tonight. Do not plan to change the wind advisory issued earlier. The latest RAP continues to show a strengthening pressure gradient over south central NEB and north central KS that may be strong enough for sustained winds of 30 mph for a brief period. Otherwise the NAM and GFS are more marginal with the pressure gradient and do not produce as strong of winds. For highs today, am a little concerned the scattered precip and cloud cover could hold temps down especially over northeast KS where this is likely to hang on longer into the afternoon. So tweaked temps down a degree or two over northeast zones. Although there may still be enough mixing and insolation across north central KS for highs to reach around 80. With rain and some cold air advection behind the front tonight, trended min temps Thursday morning down towards the MOS consensus of lower 50s in north central KS to the mid and upper 50s across eastern KS. If the front moves through a little quicker, lows in the east are likely to be to warm. .LONG TERM...(Thursday through Tuesday) Issued at 341 AM CDT WED APR 23 2014 Cold front will continue to move southeastward and out of the far southeast corner by mid morning on Thursday as the upper trough axis swings through CWA. Will therefore continue a steady decline in precipitation chances over the eastern CWA through the morning hours and a dry afternoon forecast. Although the day may start out wet and cloudy early...decreasing clouds and backing low level winds will aid in temperatures rising back into the low to mid 70s for highs. Winds back around to light southwesterly overnight with lows in the 40s before increasing through the day Friday with mostly sunny skies. Have therefore edged high temperatures upwards slightly to around 80 in many areas. Elevated moisture return and weak instability slowly increase late Friday night/early Saturday morning across the southern CWA and have maintained low chances for thunderstorms. A better chance for thunderstorms will exist with the deeper moisture and instability later in the day into early Sunday as the next strong shortwave trough digs into the desert southwest and ejects out into the central high plains. Thunderstorms may remain elevated until an initial capping inversion is overcome for surface based storms to develop. Either way...strong to severe thunderstorms will be possible Saturday into Sunday ahead of an expected dry slot as the system rotates out into the plains and occludes. It will then slow and shift east and southeastward into the MS river valley with a lingering chance for showers in its wake as much cooler air filters into the area from the north for Monday and especially Tuesday. Highs in the 70s on Saturday will lower into the low to mid 60s for Monday...then the 50s for Tuesday. Lows by Wednesday morning could fall into the mid to upper 30s. && .AVIATION...(For the 12Z TAFs through 12Z Thursday Morning) Issued at 609 AM CDT WED APR 23 2014 The RAP and NAM show isentropic upglide within the warm air advection pattern continuing into the early afternoon. Regional radars are hinting at more elevated showers starting to form over southwest KS. Therefore will carry -SHRA until 19Z when the moisture advection and isentropic lift diminish. Low level moisture advection remains rather modest so even with the -SHRA expect VFR conditions to prevail until the front moves through with TSRA. This looks to occur at the terminals after 06Z based on the RAP and NAM forecasts. Have MVFR CIGS and VSBY as the TSRA pass through. Confidence in timing the ending and beginning of precip is average and may need to be adjusted plus or minus a hour or so. Otherwise expect increasing south and southeasterly winds through the morning as the pressure gradient strengthens. && .TOP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY from 10 AM this morning to 6 PM CDT this evening FOR KSZ008-009-020-021-034-035. && $$ SHORT TERM...Wolters LONG TERM...63 AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
951 AM EDT WED APR 23 2014 .SYNOPSIS... HIGH PRESSURE WILL SLOWLY BUILD OVER THE AREA THROUGH THURSDAY. A COLD FRONT WILL PASS THROUGH THE AREA FRIDAY AND ANOTHER COLD FRONT IS EXPECTED TO MOVE THROUGH SATURDAY. HIGH PRESSURE WILL BUILD OVERHEAD SUNDAY AS THE COLD FRONT STALLS TO OUR SOUTH. WAVES OF LOW PRESSURE WILL DEVELOP ALONG THE STALLED BOUNDARY...BRINGING UNSETTLED CONDITIONS TO THE AREA NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 1023 MB SFC HIGH LOCATED OVER THE UPPER MIDWEST/GREAT LAKES WHILE A COLD FRONT STETCHES FROM A 995 MB SFC LOW OVER MAINE SOUTHWESTWARD TOWARD THE SERN ATLANTIC COAST. A RELATIVELY STRONG PRESSURE GRADIENT BETWEEN THESE SYSTEMS WILL RESULT IN A BREEZY DAY. STRONG CAA ON THE BACKSIDE OF THE LOW HAS RESULTED IN A WELL-MIXED BOUNDARY LAYER UP TO 800 MB AS SEEN ON THE 12Z IAD RAOB SOUNDING. ACCORDINGLY WINDS WILL PICK UP QUICKLY THIS MRNG...RESULTING IN GUSTS OF 30-40 MPH FOR MUCH OF TDA. CAA PATTERN HAS PRODUCED STRATOCU AS MOISTURE AT THE TOP OF THE MIXED LAYER IS TRAPPED BELOW THE SUBSIDENCE INVERSION FIELD. UPDATED SKY COVER FCST GRIDS USING THE RH FIELD AT THE TOP OF THE MIXING LAYER FROM THE RAP TO ACCOUNT FOR THE EVOLUTION OF STRATOCU TDA. PARTLY SUNNY TO MOSTLY CLOUDY SKIES CAN BE EXPECTED ACROSS THE NRN HALF OF THE CWA THIS MRNG BEFORE CLOUDS ERODE FROM S TO N INTO THE AFTN. LOWERED MAX TEMPS A COUPLE OF DEGREES NEAR THE MASON-DIXON LINE TO THE UPPER 50S...WHERE CLOUD COVER MAY HOLD ON THE LONGEST. OTHERWISE...OFFICIAL MAX TEMP FCST IN LOW TO MID 60S FALLS ON THE WARMER SIDE OF GUIDANCE WITH STRONG HEATING AND DOWNSLOPING FLOW. ONCE THE UPPER VORT COMPLETELY MOVES OFF THE COAST SLOWLY TNGT... WINDS WILL DROP OFF OVER THE WRN HALF OF THE REGION. NERN MD WILL REMAIN THE SOME OF THE BREEZIER CONDITIONS LATE TONIGHT... SINCE THE RIBBON OF UPPER VORTICITY WILL STILL BE HANGING OUT OVER DELMARVA - VERY SLOWLY DRIFTING TOWARD THE COAST. A DAY`S WORTH OF DRY AIR WILL ALLOW TEMPS TO DROP BACK DOWN AGAIN INTO THE M-U30S FOR OVERNIGHT LOWS. A FEW AREAS OF THE CWA LIKE THE APLCNS AND SHEN VLY WILL SEE TEMPS HOVERING AROUND FREEZING. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... SURFACE HIGH PRESSURE WILL BUILD OVER THE REGION THURSDAY WHILE AN UPPER-LEVEL RIDGE MOVES OVERHEAD DURING THIS TIME. PLENTY OF SUBSIDENCE WILL ALLOW FOR DRY CONDITIONS ALONG WITH SUNSHINE. MAX TEMPS WILL BE NEAR CLIMO...RANGING FROM THE 50S IN THE MOUNTAINS TO THE MID AND UPPER 60S ACROSS MOST OTHER LOCATIONS. SOME AREAS ACROSS CENTRAL VIRGINIA AND THE VALLEYS OF EASTERN WEST VIRGINIA MAY REACH INTO THE 70S. THE SURFACE HIGH AND UPPER-LEVEL RIDGE AXIS WILL SLIDE TO THE EAST THURSDAY NIGHT AND A COLD FRONT WILL APPROACH FROM THE OHIO VALLEY. CLOUDS ASSOCIATED WITH THIS SYSTEM WILL OVERSPREAD THE AREA...BUT PRECIPITATION SHOULD HOLD OFF UNTIL FRIDAY. MIN TEMPS WILL RANGE FROM THE LOWER TO MIDDLE 40S ACROSS MOST LOCATIONS TO NEAR 50 IN DOWNTOWN WASHINGTON AND BALTIMORE. && .LONG TERM /FRIDAY THROUGH TUESDAY/... A COLD FRONT WILL PASS THROUGH THE REGION FRIDAY...BRINGING A FEW SHOWERS WITH IT. AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT...BUT INSTABILITY WILL BE LIMITED SO ANY SEVERE THREAT SHOULD REMAIN WELL TO OUR SOUTH. THE BOUNDARY WILL MOVE EAST FRIDAY NIGHT ALLOWING FOR DRY CONDITIONS...BUT ANOTHER COLD FRONT WILL PASS THROUGH THE REGION SATURDAY AFTERNOON. LITTLE MOISTURE WILL BE ASSOCIATED WITH THIS SO MOST AREAS WILL LIKELY REMAIN DRY. SATURDAY WILL TURN OUT MILD AHEAD OF THE BOUNDARY DUE TO A DOWNSLOPING WESTERLY FLOW AHEAD OF THE FRONT. CANADIAN HIGH PRESSURE WILL BUILD OVERHEAD SATURDAY NIGHT THROUGH SUNDAY BEHIND THE FRONT...BRINGING DRY AND COOLER CONDITIONS. CUTOFF LOW PRESSURE WILL TRACK THROUGH THE PLAINS INTO THE MIDWEST NEXT WEEK. A WARM FRONT WILL STALL OUT NEAR THE REGION DURING THIS TIME AND UNSETTLED CONDITIONS ARE POSSIBLE. CERTAINTY IN THE FORECAST REMAINS LOW AT THIS TIME. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... GUSTY NW WINDS WILL BE THE MAIN WX STORY TDA FOR THE AREA TERMINALS. NW WINDS HAVE QUICKLY PICKED UP THIS MRNG WITH GUSTS 25-35 KT ALREADY BEING REPORTED AT 13Z. EXPECT GUSTS OF THIS MAGNITUDE TO CONTINUE THRU AFTN BEFORE GRADUALLY SUBSIDING TOWARD SUNSET THIS EVE. BKN STRATOCU FIELD BETWEEN 4-5 KFT THIS MRNG WILL IMPACT THE TERMINALS EXCEPT FOR CHO BEFORE ERODING FROM S TO N THIS AFTN.NW WINDS AROUND 10 KT CONTINUES TNGT...WITH SLIGHTLY HIGHER WINDS AT DCA-BWI-MTN. NORTHWEST WINDS WILL GUST AROUND 20 TO 25 KNOTS THURSDAY ACROSS THE EASTERN TERMINALS. WINDS WILL BE LIGHTER ACROSS KMRB AND KCHO. HIGH PRESSURE OVER THE TERMINALS THURSDAY EVENING WILL SHIFT EAST OVERNIGHT. A SOUTHERLY FLOW WILL DEVELOP AHEAD OF A COLD FRONT DURING THIS TIME. THE COLD FRONT WILL PASS THROUGH THE TERMINALS FRIDAY WITH A FEW SHOWERS LIKELY. ANOTHER COLD FRONT WILL PASS THROUGH SATURDAY AFTERNOON AND EVENING AND IT WILL STALL OUT JUST TO THE SOUTH FOR SUNDAY. VFR CONDITONS ARE EXPECTED DURING THIS TIME. && .MARINE... A STRONG PRESSURE GRADIENT OVER THE WATERS HAS PRODUCED WIDESPREAD 20-30 KT WIND GUSTS WITH LOCALLY HIGHER GUSTS TO 35 KT. GALE WARNING REMAINS IN EFFECT FOR ALL OF THE WATERS TDA. MIXING WILL DEEPEN EVEN FURTHER THIS AFTN BUT MODELS SHOW THE WIND FIELD AT THE TOP OF THIS MIXING LAYER WEAKENING A BIT. MAY BE ABLE TO CANCEL THE GALE WARNING A FEW HRS EARLY THIS AFTN WITH HIGH END SCA WINDS FAVORED. SCA CONTINUES TNGT. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE WATERS THURSDAY. WINDS WILL DIMINISH BY THURSDAY EVENING WITH HIGH PRESSURE OVERHEAD. HOWEVER...THE HIGH WILL MOVE OFF THE COAST THURSDAY NIGHT AND A COLD FRONT IS EXPECTED TO PASS THROUGH FRIDAY. ANOTHER COLD FRONT WILL LIKELY PASS THROUGH THE WATERS SATURDAY BEFORE STALLING OUT TO THE SOUTH FOR SUNDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE WATERS FRIDAY THROUGH SUNDAY. && .FIRE WEATHER... A RED FLAG WARNING HAS REPLACED THE FIRE WEATHER WATCH FOR MUCH OF THE MID ATLC REGION FROM 11 AM TO 8 PM TDA. NW WINDS OF 20-25 MPH WILL GUST FREQUENTLY BETWEEN 35 AND 40 MPH. MRNG UPDATE TO THE FCST KEEP MAX TEMPS AT OR EVEN A COUPLE OF DEGREES BELOW PREV FCST BUT DEWPOINTS WERE ALSO LOWERED THIS AFTN AS DRIER AIR MIXES DOWN TO THE SFC. PAST STUDIES HAVE SHOWN DEWPOINTS AT THE TOP OF THE BOUNDARY LAYER TO BE REPRESENTATIVE OF SFC DEWPOINTS DURING THE PEAK HEATINGS HRS IN SITUATIONS LIKE TDA. 12Z IAD RAOB SOUNDING SHOWS DEWPOINTS IN THE LOW TO MID 20S AT THE TOP OF THE BOUNDARY LAYER. THIS WILL RESULT IN RH VALUES BETWEEN 20 AND 30 PERCENT ACROSS THE MUCH OF THE AREA. FUEL MOISTURE OBS YDA WERE BETWEEN 5-8 PERCENT. ONLY LOCALIZED AREAS RECEIVED A COUPLE TENTHS OF AN INCH OF RAINFALL YESTERDAY...WHICH WAS NOT ENOUGH TO ALTER THE FUEL MOISTURE. WINDS SUBSIDE TOWARD SUNSET AND RH VALUES WILL INCREASE ABOVE CRITICAL THRESHOLDS. DRIER AIR WILL CAUSE EVEN LOWER RH VALUES THURSDAY...BUT WINDS WILL NOT BE AS STRONG. A FIRE WEATHER WATCH IS IN EFFECT FOR PORTIONS OF CENTRAL AND NORTHEASTERN MARYLAND WHERE THE WINDS WILL BE STRONGEST. A COLD FRONT WILL PASS THROUGH THE AREA FRIDAY...BRINGING A FEW SHOWERS BUT RAINFALL AMOUNTS WILL LIKELY AVERAGE OUT TO BE LIGHT. && .TIDES/COASTAL FLOODING... STRONG NORTHWEST WINDS TODAY WILL CAUSE TIDAL BLOWOUT. THE NORTHWEST FLOW WILL CONTINUE THROUGH THURSDAY...BUT NOT AS STRONG. HOWEVER...TIDAL BLOWOUT CONDITIONS ARE POSSIBLE DURING THIS TIME AS WELL. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR DCZ001. FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR DCZ001. MD...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR MDZ003>007- 009>011-013-014-016>018-502. FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR MDZ004>007-009>011-013-014-018. VA...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR VAZ025>031- 036>040-042-050>057-501-502-504. FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON FOR VAZ054. WV...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR WVZ050>053- 055-502-504-506. MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EDT THURSDAY FOR ANZ530>543. GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR ANZ530>543. && $$ SYNOPSIS...BJL/JRK NEAR TERM...JRK/GMS SHORT TERM...BJL LONG TERM...BJL/GMS AVIATION...JRK/BJL MARINE...JRK/BJL FIRE WEATHER...JRK TIDES/COASTAL FLOODING...JRK/BJL
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
643 AM CDT Wed Apr 23 2014 .SHORT TERM: (Today through Friday) Issued at 342 AM CDT Wed Apr 23 2014 Surface ridge extending from Wisconsin south/southwest into the Mid-Mississippi Valley and back into east Texas will move east today ahead of developing low pressure over the Great Plains. Increasing southerly low level flow will result. All short-range model guidance develops an area of warm advection showers over the eastern Plains and pushes it east northeast into northwest Missouri and Iowa today. Looks possible that the southeast edge of the showers could clip our area, but low level air is pretty dry according to the NAM, GFS, and RUC and the primary thrust of moisture return will be back over western Missouri so have only introduced slight chance PoPs over our northwest counties. We should see highs pretty close to what occurred yesterday even with the warm advection since we`ll be starting out the day cooler than Tuesday morning. The exception will be central Missouri where morning lows should be a bit warmer than areas further east. The shortwave currently digging across the Rockies will move out into the Great Plains tonight and the resulting cold front will move into northwest Missouri around 12Z. Still looks like showers and thunderstorms will be ongoing along and ahead of the front as it moves through the CWFA on Thursday. Diurnal heating will likely be limited due to cloud cover and advancing precip from the west, so instability still looks relatively weak. While there should be enough CAPE for thunderstorms, widespread severe weather does not look likely at this time. Stuck closer to the warmer MAV guidance for highs since morning lows will be around 50 across the area and 15-20 degrees of rise should be attainable in warm advection this time of year regardless of cloud cover. Guidance is in good agreement with pushing the front through the entire area shortly after 00Z. Still have some lingering precip east of the Mississippi River Thursday evening as the front exits, but dry after midnight. Pacific high builds across the region Friday morning. As opposed to a colder Canadian airmass, the Pacific ridge should produce temperatures near or slightly above normal in the upper 40s to low 50s Friday morning. West-southwest flow develops Friday morning as the high scoots quickly into the Tennessee Valley so expect temperatures to rebound into the mid and upper 70s. Carney .LONG TERM: (Saturday through Tuesday) Issued at 342 AM CDT Wed Apr 23 2014 While the medium range guidance is coming into better agreement on the overall synoptic pattern, the smaller scale is still unclear. Generally, a secondary cold front will dip south across the Upper Midwest driven south by the last vestiges of Thursday`s shortwave. The front will stall somewhere across the Midwest on Saturday, though models can`t make up their minds where. GFS stalls the front across south/southwest Missouri Saturday morning, while the ECMWF stalls it out over northern Iowa. The GEM is right about in the middle stalling the front over northern Missouri. All three models have some low level baroclinicity over our area, whether it is the primary baroclinic zone associated with the front (GFS/GEM) or a secondary baroclinic zone left over from the Pacific airmass which will be exiting to the east (EC). Warm advection begins Saturday morning with a 30+ kt low level jet pointed at this baroclinic zone and all three models print out some light precip. Have therefore kept chance pops going in central Missouri, and would not be surprised if subsequent shifts need to bump up pops a bit more across the area if model trends become more consistent. The front remains stalled somewhere between Springfield Missouri and Davenport Iowa depending on which model you believe through Monday as the longwave trof over the Pacific moves inland, and becomes negatively tilted over the Rockies and Great Plains. A strong surface low develops as a result and it moves into the Mississippi Valley Monday night into Tuesday. The upper trof cuts off and becomes stagnant while the surface low tracks across Missouri into the Ohio Valley Tuesday. Pattern is more reminiscent of late Fall or Winter than mid to late Spring. Unsure how likely this is to happen, but this is at least the second run in a row that I`ve seen do this. Will have to wait and see, but right now it looks like a cold/wet end to April. Carney && .AVIATION: (For the 12z TAFs through 12z Thursday Morning) Issued at 628 AM CDT Wed Apr 23 2014 VFR flight conditions will continue to prevail this forecast period, with winds veering and becoming more southerly as the surface ridge moves off to the east. The next system which will impact the area is taking shape over the plains, and as it moves east, area TAF sites will see winds increase to roughly 10-15KT by late morning/early afternoon in response to a tightening pressure gradient and increased southerly flow. The aforementioned pressure gradient should also be enough to produce some gusts around 20-22KT beginning by late afternoon, mainly impacting KCOU and KUIN. Only increasing midlevel clouds are expected through the period, and while there is a chance for precipitation to move into central and northeast Missouri late Wednesday night, exact timing has yet to be pinned down, and as the onset would be in the last few hours of the forecast period, have not included mention at this time. Specifics for KSTL: VFR flight conditions will prevail through the forecast period, with winds continuing to veer and become more southerly as the surface ridge moves east and the next system to impact the area takes shape over the plains. Expect winds to increase to about 12-14KT by early afternoon, remaining fairly steady overnight, and become gusty Thursday morning as the surface pressure gradient tightens ahead of the approaching system. Showers and thunderstorms will move through the area on Thursday, though exact timing for impact at KSTL has yet to be pinned down, and as it would likely be within the last couple hours of the forecast period, have not mentioned it in the TAF at this time. Prior to the storms, expect a gradual increase in midlevel clouds overspreading the area from west to east today/tonight. JP && .PRELIMINARY POINT TEMPS/POPS: Saint Louis 69 52 72 52 / 5 10 80 30 Quincy 66 49 66 46 / 10 20 80 20 Columbia 72 53 70 47 / 10 30 80 10 Jefferson City 75 53 70 47 / 10 20 80 10 Salem 65 49 72 49 / 5 5 70 50 Farmington 69 48 73 47 / 5 5 80 30 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1007 AM CDT WED APR 23 2014 .SYNOPSIS... ISSUED AT 356 AM CDT WED APR 23 2014 H5 ANALYSIS FROM EARLIER THIS EVENING HAS A RIDGE OF HIGH PRESSURE EXTENDING FROM THE SOUTHERN PLAINS...NWD INTO NORTHERN SASKATCHEWAN. OFF TO THE WEST...AN UPPER LEVEL LOW WAS NOTED OFF THE COAST OF BRITISH COLUMBIA WITH A TROUGH EXTENDING SSE OF THIS FEATURE INTO SOUTHERN CALIFORNIA. WV IMAGERY AS OF 06Z TONIGHT HAS A NICE SHORTWAVE OVER NRN UTAH AND SERN IDAHO. IN ADVANCE OF THIS FEATURE...THUNDERSTORMS WERE PRESENT ACROSS NWRN COLORADO AND SRN WYOMING. FURTHER EAST...ISOLATED THUNDERSTORMS WERE PRESENT OVER SOUTH DAKOTA...AS WELL AS NORTH CENTRAL KS AND PORTIONS OF SOUTH CENTRAL AND SOUTHEASTERN NEBRASKA. THIS ACTIVITY HAS INCREASED SOMEWHAT IN COVERAGE OVER THE PAST 1 TO 2 HRS THANKS TO A 50+KT LOW LEVEL JET WHICH EXTENDS FROM SOUTH CENTRAL INTO NORTH CENTRAL NEBRASKA. AT THE SURFACE...ACROSS WESTERN AND NORTH CENTRAL NEBRASKA...GUSTY SOUTHEASTERLY WINDS WERE PRESENT EAST OF A LINE FROM AINSWORTH TO OGALLALA THANKS TO A SURFACE LOW OVER SERN MT...WITH A SURFACE TROUGH EXTENDING SWD INTO EASTERN COLORADO. SUSTAINED SPEEDS WERE GENERALLY 15 TO 25 MPH...WITH SOME GUSTS UP TO 35 MPH. UNDER PARTLY CLOUDY SKIES...3 AM CDT TEMPERATURES RANGED FROM 53 AT BROKEN BOW TO 60 AT IMPERIAL AND THEDFORD. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 356 AM CDT WED APR 23 2014 OVER THE NEXT 24 HOURS...PRECIPITATION CHANCES AND THE SEVERE THREAT IN THE EASTERN FORECAST AREA ARE THE MAIN FORECAST CONCERN. OTHER CONCERNS CENTER ON WINDS THIS MORNING IN THE EAST...ALONG WITH THE FIRE DANGER THREAT IN THE WEST THIS AFTERNOON. FOR THIS MORNING...THE BEFORE MENTIONED SURFACE TROUGH OF LOW PRESSURE WILL ENTER THE PANHANDLE BY MID MORNING. STRONG SOUTHERLY WINDS WILL CONTINUE ACROSS THE EASTERN QUARTER OF THE FORECAST AREA THROUGH MID MORNING AS A 40 TO 50 KT LOW LEVEL JET REMAINS PRESENT ACROSS THE FAR NERN CWA. THIS FEATURE WILL SLIDE EAST OF THE FORECAST AREA BY 18Z WHILE THE SURFACE TROUGH PUSHES EAST TO A LINE FROM VALENTINE...TO NORTH PLATTE TO HAYES CENTER. GIVEN THE STRONG LOW LEVEL JET THIS MORNING...WE COULD FLIRT WITH WIND ADVISORY CRITERIA WINDS IN THE FAR NORTHEASTERN CWA THROUGH LATE MORNING. RIGHT NOW...BASED ON THE HRRR AND STATISTICAL GUIDANCE...FCST WINDS ARE JUST BELOW ADVISORY CRITERIA AND PLAN ON NO HEADLINES ATTM. WILL CONTINUE TO MONITOR THIS THROUGH SUNRISE AS THE H85 JET MIGRATES FROM THE HIGHWAY 83 CORRIDOR EAST TOWARD SUNRISE. LATER THIS AFTERNOON...A STRONG UPPER LEVEL DISTURBANCE WILL APPROACH WESTERN NEBRASKA. AS CAPPING ERODES DURING THE LATE AFTERNOON HOURS...THUNDERSTORMS ARE EXPECTED TO FIRE INVOF OF THE SURFACE TROUGH. ATTM...THIS FEATURE IS EXPECTED TO BE ALONG A LINE FROM BASSETT TO NORTH PLATTE TO EAST OF HAYES CENTER. STRONG SOUTHERLY WINDS EAST OF THE TROUGH...WILL PUSH PLENTY OF LOW LEVEL MOISTURE NWD FROM CENTRAL KS TDY. WITH MOISTURE IN PLACE...AND STRONG INSTABILITY...THUNDERSTORMS LOOK LIKE A SAFE BET ALONG AND EAST OF THE SURFACE TROUGH THIS AFTERNOON. IN OUR FAR SOUTHEAST AND EASTERN ZONES...SHEAR WILL BE FAVORABLE FOR SEVERE STORMS THIS AFTERNOON INTO THE EVENING HOURS. AT THIS TIME...HAIL AND WINDS WILL BE THE MAIN SEVERE THREAT AS DEEP LAYER WIND SHEAR IS UNIDIRECTIONAL. WITH THE POSITION OF THE BEFORE MENTIONED SURFACE TROUGH...PRECIP CHANCES WILL BE HIGHEST IN FAR EASTERN PORTIONS OF THE FORECAST AREA WITH HIGH CHANCE TO LOW LIKELY POPS ALONG AND EAST OF A LINE FROM ONEILL...TO BROKEN BOW...TO MAYWOOD. POPS WILL DECREASE QUICKLY WEST OF THIS LINE...WITH NO PRECIPITATION EXPECTED WEST OF A LINE FROM VALENTINE...TO SUTHERLAND...TO GRANT. THE SURFACE TROUGH WILL BE FORCED EAST OF THE FORECAST AREA BY MID EVENING...WITH THE THREAT FOR THUNDERSTORMS IN THE EAST ENDING BY MIDNIGHT TONIGHT. WITH RESPECT TO FIRE DANGER THIS AFTERNOON...WEST OF THE SURFACE TROUGH...EXTREME TO NEAR CRITICAL FIRE DANGER WILL BE POSSIBLE LATER THIS AFTERNOON...AS DRIER AIR PUSHES INTO THE PANHANDLE BEHIND THE SURFACE TROUGH. DEW POINTS WILL DROP INTO THE TWENTIES IN THE EASTERN PANHANDLE BY LATE AFTERNOON AND WITH TEMPERATURES IN THE MID TO UPPER 60S EXPECTED...RELATIVE HUMIDITIES WILL DROP TO AROUND 20 PERCENT. BREEZY WESTERLY WINDS MAY BECOME GUSTY LATER THIS AFTERNOON...PARTICULARLY IN THE EASTERN PANHANDLE THANKS TO DECENT 3 HR SURFACE PRESSURE RISES OF 3 TO 5 MB FROM 21Z TO 00Z LATE THIS AFTERNOON. ATTM...EXPECTED MINIMUM RELATIVE HUMIDITIES WILL BE JUST ABOVE RED FLAG CRITERIA SO NO FIRE HEADLINES ARE EXPECTED AT THIS TIME. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 356 AM CDT WED APR 23 2014 DRY AIR WILL BE IN PLACE THURSDAY BEHIND WEDNESDAY/S COLD FRONTAL PASSAGE. WILL BE CLOSE TO RED FLAG CRITERIA...IN WELL MIXED AND DRY ATMOSPHERE. 500M WIND SPEEDS OF 10 TO 20 KTS WILL SUPPORT SUSTAINED SURFACE WIND SPEEDS OF 15 TO 20 MPH...BUT THESE WINDS WILL SLOWLY BE DIMINISHING DURING THE TIME OF LOWEST RELATIVE HUMIDITY. WILL CONTINUE THE MENTION OF THE FIRE WEATHER CONCERN IN THE HAZARDOUS WEATHER OUTLOOK...AND HAVE THE ONCOMING SHIFT TAKE ANOTHER LOOK BEFORE ISSUING ANY TYPE OF FIRE WEATHER HEADLINES. A CHILLY NIGHT EXPECTED THURSDAY NIGHT...AS SURFACE HIGH RIDGE AXIS CROSSES THE AREA AND WINDS DECOUPLE. NOT EXPECTING BELOW FREEZING TEMPERATURES AT THIS POINT...BUT FAVORED LOW SPOTS AND RIVER VALLEYS WILL LIKELY SEE LOWS BOTTOMING OUT IN THE MIDDLE 30S. WARM AIR ADVECTION GETS UNDERWAY IN ERNEST FRIDAY...WITH SOUTHERLY FLOW ADVECTING H85 TEMPERATURES OF 20C INTO SOUTHWEST NEBRASKA BY AFTERNOON. ALL AREAS SHOULD SEE HIGHS INTO THE 70S. STILL SOME CONCERN REGARDING WILDFIRE POTENTIAL...BUT IT APPEARS THAT WINDS WILL REMAIN IN CHECK...AND DEW POINTS WILL BE SLOWLY RISING INTO THE 30S DURING THE AFTERNOON. SOUTHERLY LOW LEVEL JET CRANKS UP FRIDAY NIGHT IN RESPONSE TO DEVELOPING LOW PRESSURE ALONG THE LEE OF THE ROCKIES. THE NAM MODEL IS THE MOST AGGRESSIVE WITH THE MOISTURE RETURN AND STEEP MID LEVEL LAPSE RATES...AND THE MODEL DEVELOPS SOME DECENT MID LEVEL CAPE AS A RESULT. THE OTHER MODELS ARE SLOWER WITH THE MOISTURE RETURN...AND THE MID LEVEL LAPSE RATES ARE NOT AS STEEP. THEREFORE THESE MODELS ARE INDICATING LESS IN THE WAY OF INSTABILITY. WILL CONTINUE THE SLIGHT CHANCE OF SHOWERS IN THE FORECAST...AND WILL ADD AN ISOLATED THUNDER MENTION TO ACCOUNT FOR THE INCREASING MID LEVEL INSTABILITY IN THE NAM. FOR THE WEEKEND...A POTENT UPPER LEVEL TROUGH OF LOW PRESSURE WILL MOVE ONSHORE THE PACIFIC COAST FRIDAY EVENING. THE 23/00Z GFS AND ECMWF MODEL RUNS ARE IN EXCELLENT AGREEMENT...AND HAVE THE BASE OF THE UPPER LEVEL TROUGH SWINGING THOUGH SOUTHEAST CALIFORNIA/WESTERN ARIZONA AT 18Z SATURDAY. AT THE SURFACE...BOTH MODELS RAPIDLY DEEPEN A SURFACE LOW /NEAR 988MB/ DOWNSTREAM IN FAVORED CYCLOGENESIS REGION OF EASTERN COLORADO BY 00Z SUNDAY. THIS WILL HELP DRAW GULF MOISTURE RAPIDLY NORTHWARD INTO THE CENTRAL PLAINS. THE GFS...ECMWF AND THE GEFS ENSEMBLE MEAN REMAIN IN GOOD AGREEMENT THROUGH SUNDAY...AND BRING A POTENT/DYNAMIC NEGATIVELY TILTED UPPER TROUGH INTO THE CENTRAL PLAINS...WITH A CLOSED H5 AND H7 CIRCULATION CENTER ACROSS WESTERN KANSAS. MEANWHILE A DEEP 985MB SURFACE LOW WILL SLOWLY MIGRATE EASTWARD NEAR THE KANSAS/NEBRASKA BORDER THROUGH MONDAY. REGARDING THUNDERSTORM AND PRECIPITATION CHANCES...SEVERE WEATHER SEEMS LIKELY GIVEN SUCH STRONG DYNAMICS AND GOOD MOISTURE. IT WILL OF COURSE HINGE ON WHERE THE BOUNDARIES SET UP. THERE WILL LIKELY BE A SHARP WARM FRONT AND DRY LINE FOR CONVECTION TO FOCUS ON/NEAR. WILL NOT TRY TO PIN DOWN EXACT LOCATION OF THESE FEATURES JUST YET...BUT INDICATIONS ARE THAT BOTH THESE BOUNDARIES MAY BE IN OR VERY NEAR THE FORECAST AREA FOR MUCH OF THE WEEKEND. WITH SUCH A STRONG SYSTEM...THERE WILL ALSO BE A PRONOUNCED DRY SLOT. THE CURRENT STORM TRACK ACROSS NORTHERN KANSAS SUNDAY INTO MONDAY...WOULD FAVOR THE DRY SLOT AIMING MORE AT SOUTHERN/SOUTHEAST NEBRASKA NEBRASKA. THIS IS GOOD NEWS FOR OUR AREA...AS A PERSISTENT SHIELD OF RAIN COULD LINGER FOR MANY HOURS. THIS HAS THE POTENTIAL TO BE A SIGNIFICANT AND SLOW MOVING STORM SYSTEM...AND WILL CONTINUE TO MONITOR THE LATEST TRENDS CLOSELY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 633 AM CDT WED APR 23 2014 A SURFACE TROUGH OF LOW PRESSURE WILL TRACK ACROSS WESTERN AND NORTH CENTRAL NEBRASKA OVER THE NEXT 24 HOURS RESULTING IN AN INCREASED THREAT FOR THUNDERSTORMS ACROSS SOUTHWESTERN NEBRASKA...AS WELL AS PORTIONS OF CENTRAL AND NORTH CENTRAL NEBRASKA. FOR THE KLBF TERMINAL THROUGH 20Z THIS AFTERNOON...EXPECT BROKEN CIGS AON 20000 FT AGL. BY 20Z CIGS WILL LOWER TO AROUND 7000 FT AGL AS THE SURFACE TROUGH APPROACHES. THUNDERSTORMS ARE POSSIBLE IN THE VICINITY OF THE TERMINAL...ESPECIALLY JUST OFF TO THE EAST OF KLBF FROM 20Z THROUGH 02Z THURSDAY. SKIES ARE EXPECTED TO CLEAR AFTER 06Z TONIGHT. FOR THE KVTN TERMINAL...EXPECT SCATTERED TO BROKEN CIGS RANGING FROM 12000 TO 15000 FT AGL THROUGH THE EVENING HOURS WITH CLEARING EXPECTED THEREAFTER. FOR BOTH TERMINALS...SOUTHERLY WINDS WILL SHIFT TO THE WEST THEN NORTHWEST THIS AFTERNOON. WIND SPEEDS WILL RANGE FROM 15 TO 25 KTS WITH SOME GUSTS TO AROUND 30 KTS LATE THIS AFTERNOON AND EARLY THIS EVENING. && .FIRE WEATHER...UPDATED ISSUED AT 1004 AM CDT WED APR 23 2014 CLOSELY WATCHING FIRE WEATHER CONDITIONS ACROSS THE PANHANDLE AND THE WESTERN SANDHILLS /FIRE ZONE 204/ FOR THIS AFTERNOON. DRY AIR WILL MOVE INTO THESE AREAS THROUGH THE DAY AS A COLD FRONT...NOW LOCATED FROM FAR NORTHEAST COLORADO /WEST OF KHEQ/ NORTH THROUGH THE EASTERN PANHANDLE AND INTO WESTERN SOUTH DAKOTA /NEAR KPHP/. DEEP MIXING IS EXPECTED IN THESE AREAS THIS AFTERNOON...UP TO 700MB AND BELIEVE WINDS MAY BE A BIT STRONGER AND DEWPOINTS A BIT DRIER THAN HAD BEEN ORIGINALLY THOUGHT. USING A MIXED LAYER DEWPOINT...SOME PLACES COULD SEE VALUES DOWN NEAR 20F OR EVEN THE LOW TEENS. THE FORECAST DOESN/T GO THIS LOW AT THIS TIME...BUT WILL BE WATCHING CLOSELY IN THE COMING HOURS IF BY CHANCE A SHORT FUSED RED FLAG WARNING MAY BE NEEDED. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...TAYLOR AVIATION...CLB FIRE WEATHER...BROOKS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
633 AM CDT WED APR 23 2014 .SYNOPSIS... ISSUED AT 356 AM CDT WED APR 23 2014 H5 ANALYSIS FROM EARLIER THIS EVENING HAS A RIDGE OF HIGH PRESSURE EXTENDING FROM THE SOUTHERN PLAINS...NWD INTO NORTHERN SASKATCHEWAN. OFF TO THE WEST...AN UPPER LEVEL LOW WAS NOTED OFF THE COAST OF BRITISH COLUMBIA WITH A TROUGH EXTENDING SSE OF THIS FEATURE INTO SOUTHERN CALIFORNIA. WV IMAGERY AS OF 06Z TONIGHT HAS A NICE SHORTWAVE OVER NRN UTAH AND SERN IDAHO. IN ADVANCE OF THIS FEATURE...THUNDERSTORMS WERE PRESENT ACROSS NWRN COLORADO AND SRN WYOMING. FURTHER EAST...ISOLATED THUNDERSTORMS WERE PRESENT OVER SOUTH DAKOTA...AS WELL AS NORTH CENTRAL KS AND PORTIONS OF SOUTH CENTRAL AND SOUTHEASTERN NEBRASKA. THIS ACTIVITY HAS INCREASED SOMEWHAT IN COVERAGE OVER THE PAST 1 TO 2 HRS THANKS TO A 50+KT LOW LEVEL JET WHICH EXTENDS FROM SOUTH CENTRAL INTO NORTH CENTRAL NEBRASKA. AT THE SURFACE...ACROSS WESTERN AND NORTH CENTRAL NEBRASKA...GUSTY SOUTHEASTERLY WINDS WERE PRESENT EAST OF A LINE FROM AINSWORTH TO OGALLALA THANKS TO A SURFACE LOW OVER SERN MT...WITH A SURFACE TROUGH EXTENDING SWD INTO EASTERN COLORADO. SUSTAINED SPEEDS WERE GENERALLY 15 TO 25 MPH...WITH SOME GUSTS UP TO 35 MPH. UNDER PARTLY CLOUDY SKIES...3 AM CDT TEMPERATURES RANGED FROM 53 AT BROKEN BOW TO 60 AT IMPERIAL AND THEDFORD. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 356 AM CDT WED APR 23 2014 OVER THE NEXT 24 HOURS...PRECIPITATION CHANCES AND THE SEVERE THREAT IN THE EASTERN FORECAST AREA ARE THE MAIN FORECAST CONCERN. OTHER CONCERNS CENTER ON WINDS THIS MORNING IN THE EAST...ALONG WITH THE FIRE DANGER THREAT IN THE WEST THIS AFTERNOON. FOR THIS MORNING...THE BEFOREMENTIONED SURFACE TROUGH OF LOW PRESSURE WILL ENTER THE PANHANDLE BY MID MORNING. STRONG SOUTHERLY WINDS WILL CONTINUE ACROSS THE EASTERN QUARTER OF THE FORECAST AREA THROUGH MID MORNING AS A 40 TO 50 KT LOW LEVEL JET REMAINS PRESENT ACROSS THE FAR NERN CWA. THIS FEATURE WILL SLIDE EAST OF THE FORECAST AREA BY 18Z WHILE THE SURFACE TROUGH PUSHES EAST TO A LINE FROM VALENTINE...TO NORTH PLATTE TO HAYES CENTER. GIVEN THE STRONG LOW LEVEL JET THIS MORNING...WE COULD FLIRT WITH WIND ADVISORY CRITERIA WINDS IN THE FAR NORTHEASTERN CWA THROUGH LATE MORNING. RIGHT NOW...BASED ON THE HRRR AND STATISTICAL GUIDANCE...FCST WINDS ARE JUST BELOW ADVISORY CRITERIA AND PLAN ON NO HEADLINES ATTM. WILL CONTINUE TO MONITOR THIS THROUGH SUNRISE AS THE H85 JET MIGRATES FROM THE HIGHWAY 83 CORRIDOR EAST TOWARD SUNRISE. LATER THIS AFTERNOON...A STRONG UPPER LEVEL DISTURBANCE WILL APPROACH WESTERN NEBRASKA. AS CAPPING ERODES DURING THE LATE AFTERNOON HOURS...THUNDERSTORMS ARE EXPECTED TO FIRE INVOF OF THE SURFACE TROUGH. ATTM...THIS FEATURE IS EXPECTED TO BE ALONG A LINE FROM BASSETT TO NORTH PLATTE TO EAST OF HAYES CENTER. STRONG SOUTHERLY WINDS EAST OF THE TROUGH...WILL PUSH PLENTY OF LOW LEVEL MOISTURE NWD FROM CENTRAL KS TDY. WITH MOISTURE IN PLACE...AND STRONG INSTABILITY...THUNDERSTORMS LOOK LIKE A SAFE BET ALONG AND EAST OF THE SURFACE TROUGH THIS AFTERNOON. IN OUR FAR SOUTHEAST AND EASTERN ZONES...SHEAR WILL BE FAVORABLE FOR SEVERE STORMS THIS AFTERNOON INTO THE EVENING HOURS. AT THIS TIME...HAIL AND WINDS WILL BE THE MAIN SEVERE THREAT AS DEEP LAYER WIND SHEAR IS UNIDIRECTIONAL. WITH THE POSITION OF THE BEFOREMENTIONED SURFACE TROUGH...PRECIP CHANCES WILL BE HIGHEST IN FAR EASTERN PORTIONS OF THE FORECAST AREA WITH HIGH CHANCE TO LOW LIKELY POPS ALONG AND EAST OF A LINE FROM ONEILL...TO BROKEN BOW...TO MAYWOOD. POPS WILL DECREASE QUICKLY WEST OF THIS LINE...WITH NO PRECIPITATION EXPECTED WEST OF A LINE FROM VALENTINE...TO SUTHERLAND...TO GRANT. THE SURFACE TROUGH WILL BE FORCED EAST OF THE FORECAST AREA BY MID EVENING...WITH THE THREAT FOR THUNDERSTORMS IN THE EAST ENDING BY MIDNIGHT TONIGHT. WITH RESPECT TO FIRE DANGER THIS AFTERNOON...WEST OF THE SURFACE TROUGH...EXTREME TO NEAR CRITICAL FIRE DANGER WILL BE POSSIBLE LATER THIS AFTERNOON...AS DRIER AIR PUSHES INTO THE PANHANDLE BEHIND THE SURFACE TROUGH. DEW POINTS WILL DROP INTO THE TWENTIES IN THE EASTERN PANHANDLE BY LATE AFTERNOON AND WITH TEMPERATURES IN THE MID TO UPPER 60S EXPECTED...RELATIVE HUMIDITIES WILL DROP TO AROUND 20 PERCENT. BREEZY WESTERLY WINDS MAY BECOME GUSTY LATER THIS AFTERNOON...PARTICULARLY IN THE EASTERN PANHANDLE THANKS TO DECENT 3 HR SURFACE PRESSURE RISES OF 3 TO 5 MB FROM 21Z TO 00Z LATE THIS AFTERNOON. ATTM...EXPECTED MINIMUM RELATIVE HUMIDITIES WILL BE JUST ABOVE RED FLAG CRITERIA SO NO FIRE HEADLINES ARE EXPECTED AT THIS TIME. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 356 AM CDT WED APR 23 2014 DRY AIR WILL BE IN PLACE THURSDAY BEHIND WEDNESDAY/S COLD FRONTAL PASSAGE. WILL BE CLOSE TO RED FLAG CRITERIA...IN WELL MIXED AND DRY ATMOSPHERE. 500M WIND SPEEDS OF 10 TO 20 KTS WILL SUPPORT SUSTAINED SURFACE WIND SPEEDS OF 15 TO 20 MPH...BUT THESE WINDS WILL SLOWLY BE DIMINISHING DURING THE TIME OF LOWEST RELATIVE HUMIDITY. WILL CONTINUE THE MENTION OF THE FIRE WEATHER CONCERN IN THE HAZARDOUS WEATHER OUTLOOK...AND HAVE THE ONCOMING SHIFT TAKE ANOTHER LOOK BEFORE ISSUING ANY TYPE OF FIRE WEATHER HEADLINES. A CHILLY NIGHT EXPECTED THURSDAY NIGHT...AS SURFACE HIGH RIDGE AXIS CROSSES THE AREA AND WINDS DECOUPLE. NOT EXPECTING BELOW FREEZING TEMPERATURES AT THIS POINT...BUT FAVORED LOW SPOTS AND RIVER VALLEYS WILL LIKELY SEE LOWS BOTTOMING OUT IN THE MIDDLE 30S. WARM AIR ADVECTION GETS UNDERWAY IN ERNEST FRIDAY...WITH SOUTHERLY FLOW ADVECTING H85 TEMPERATURES OF 20C INTO SOUTHWEST NEBRASKA BY AFTERNOON. ALL AREAS SHOULD SEE HIGHS INTO THE 70S. STILL SOME CONCERN REGARDING WILDFIRE POTENTIAL...BUT IT APPEARS THAT WINDS WILL REMAIN IN CHECK...AND DEW POINTS WILL BE SLOWLY RISING INTO THE 30S DURING THE AFTERNOON. SOUTHERLY LOW LEVEL JET CRANKS UP FRIDAY NIGHT IN RESPONSE TO DEVELOPING LOW PRESSURE ALONG THE LEE OF THE ROCKIES. THE NAM MODEL IS THE MOST AGGRESSIVE WITH THE MOISTURE RETURN AND STEEP MID LEVEL LAPSE RATES...AND THE MODEL DEVELOPS SOME DECENT MID LEVEL CAPE AS A RESULT. THE OTHER MODELS ARE SLOWER WITH THE MOISTURE RETURN...AND THE MID LEVEL LAPSE RATES ARE NOT AS STEEP. THEREFORE THESE MODELS ARE INDICATING LESS IN THE WAY OF INSTABILITY. WILL CONTINUE THE SLIGHT CHANCE OF SHOWERS IN THE FORECAST...AND WILL ADD AN ISOLATED THUNDER MENTION TO ACCOUNT FOR THE INCREASING MID LEVEL INSTABILITY IN THE NAM. FOR THE WEEKEND...A POTENT UPPER LEVEL TROUGH OF LOW PRESSURE WILL MOVE ONSHORE THE PACIFIC COAST FRIDAY EVENING. THE 23/00Z GFS AND ECMWF MODEL RUNS ARE IN EXCELLENT AGREEMENT...AND HAVE THE BASE OF THE UPPER LEVEL TROUGH SWINGING THOUGH SOUTHEAST CALIFORNIA/WESTERN ARIZONA AT 18Z SATURDAY. AT THE SURFACE...BOTH MODELS RAPIDLY DEEPEN A SURFACE LOW /NEAR 988MB/ DOWNSTREAM IN FAVORED CYCLOGENESIS REGION OF EASTERN COLORADO BY 00Z SUNDAY. THIS WILL HELP DRAW GULF MOISTURE RAPIDLY NORTHWARD INTO THE CENTRAL PLAINS. THE GFS...ECMWF AND THE GEFS ENSEMBLE MEAN REMAIN IN GOOD AGREEMENT THROUGH SUNDAY...AND BRING A POTENT/DYNAMIC NEGATIVELY TILTED UPPER TROUGH INTO THE CENTRAL PLAINS...WITH A CLOSED H5 AND H7 CIRCULATION CENTER ACROSS WESTERN KANSAS. MEANWHILE A DEEP 985MB SURFACE LOW WILL SLOWLY MIGRATE EASTWARD NEAR THE KANSAS/NEBRASKA BORDER THROUGH MONDAY. REGARDING THUNDERSTORM AND PRECIPITATION CHANCES...SEVERE WEATHER SEEMS LIKELY GIVEN SUCH STRONG DYNAMICS AND GOOD MOISTURE. IT WILL OF COURSE HINGE ON WHERE THE BOUNDARIES SET UP. THERE WILL LIKELY BE A SHARP WARM FRONT AND DRY LINE FOR CONVECTION TO FOCUS ON/NEAR. WILL NOT TRY TO PIN DOWN EXACT LOCATION OF THESE FEATURES JUST YET...BUT INDICATIONS ARE THAT BOTH THESE BOUNDARIES MAY BE IN OR VERY NEAR THE FORECAST AREA FOR MUCH OF THE WEEKEND. WITH SUCH A STRONG SYSTEM...THERE WILL ALSO BE A PRONOUNCED DRY SLOT. THE CURRENT STORM TRACK ACROSS NORTHERN KANSAS SUNDAY INTO MONDAY...WOULD FAVOR THE DRY SLOT AIMING MORE AT SOUTHERN/SOUTHEAST NEBRASKA NEBRASKA. THIS IS GOOD NEWS FOR OUR AREA...AS A PERSISTENT SHIELD OF RAIN COULD LINGER FOR MANY HOURS. THIS HAS THE POTENTIAL TO BE A SIGNIFICANT AND SLOW MOVING STORM SYSTEM...AND WILL CONTINUE TO MONITOR THE LATEST TRENDS CLOSELY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 633 AM CDT WED APR 23 2014 A SURFACE TROUGH OF LOW PRESSURE WILL TRACK ACROSS WESTERN AND NORTH CENTRAL NEBRASKA OVER THE NEXT 24 HOURS RESULTING IN AN INCREASED THREAT FOR THUNDERSTORMS ACROSS SOUTHWESTERN NEBRASKA...AS WELL AS PORTIONS OF CENTRAL AND NORTH CENTRAL NEBRASKA. FOR THE KLBF TERMINAL THROUGH 20Z THIS AFTERNOON...EXPECT BROKEN CIGS AON 20000 FT AGL. BY 20Z CIGS WILL LOWER TO AROUND 7000 FT AGL AS THE SURFACE TROUGH APPROACHES. THUNDERSTORMS ARE POSSIBLE IN THE VICINITY OF THE TERMINAL...ESPECIALLY JUST OFF TO THE EAST OF KLBF FROM 20Z THROUGH 02Z THURSDAY. SKIES ARE EXPECTED TO CLEAR AFTER 06Z TONIGHT. FOR THE KVTN TERMINAL...EXPECT SCATTERED TO BROKEN CIGS RANGING FROM 12000 TO 15000 FT AGL THROUGH THE EVENING HOURS WITH CLEARING EXPECTED THEREAFTER. FOR BOTH TERMINALS...SOUTHERLY WINDS WILL SHIFT TO THE WEST THEN NORTHWEST THIS AFTERNOON. WIND SPEEDS WILL RANGE FROM 15 TO 25 KTS WITH SOME GUSTS TO AROUND 30 KTS LATE THIS AFTERNOON AND EARLY THIS EVENING. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...TAYLOR AVIATION...CLB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
957 AM CDT WED APR 23 2014 .UPDATE... ISSUED AT 957 AM CDT WED APR 23 2014 THE CENTER OF A SURFACE CYCLONE/TROUGH HAS NOW ENTERED SOUTHWESTERN NORTH DAKOTA. SURFACE GRADIENT WINDS HAVE COME DOWN A BIT OVER WESTERN NORTH DAKOTA AS A RESULT. HOWEVER...WIND ADVISORY CONDITIONS CONTINUE OVER THE CENTRAL AND EASTERN PART OF THE STATE. AS A RESULT...WILL CONTINUE WITH THE CURRENT WIND HEADLINES FOR THIS UPDATE. THE 12Z HRRR PROGS RAIN SHOWER REDEVELOPMENT OVER SOUTHWESTERN NORTH DAKOTA BETWEEN THE 16Z-21Z PERIOD AS THE LOW LIFTS NORTH. RAPID CITY RADAR IS ALREADY SHOWING THIS ACTIVITY DEVELOPING AS OF THIS WRITING. THEREFORE...INCREASED POPS OVER SOUTHWESTERN NORTH DAKOTA FOR LATE MORNING/EARLY AFTERNOON BASED ON CURRENT OBS AND MESOSCALE MODEL TRENDS. ALSO MODIFIED THE FIRST PERIOD WEATHER GRIDS TO GO FROM UNCERTAINTY WORDING TO COVERAGE WORDING. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 642 AM CDT WED APR 23 2014 NO SIGNIFICANT UPDATES TO THE GOING FORECAST THIS MORNING. SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO LIFT NORTHEAST THROUGH WESTERN AND CENTRAL NORTH DAKOTA. A TIGHT PRESSURE GRADIENT WILL MOVE OVER CENTRAL NORTH DAKOTA THIS MORNING AS THE GRADIENT WEAKENS IN THE WEST WITH LOW PRESSURE MOVING INTO THIS AREA DURING THE MORNING. UPDATED LATEST SENSIBLE WEATHER GRIDS. UPDATED TEXT PRODUCTS WILL BE SENT SHORTLY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 444 AM CDT WED APR 23 2014 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CONTINUED GUSTY WINDS THIS MORNING AND AFTERNOON...PRECIPITATION CHANCES AND AMOUNTS TODAY AND TONIGHT...AND THUNDERSTORM CHANCES (NON- SEVERE) MOST LOCATIONS. CURRENTLY...UPPER LEVEL TROUGH EXTENDING FROM THE PACIFIC NORTHWEST SOUTHEAST INTO THE DESERT SOUTHWEST BECOMING NEGATIVELY TILTED AND SLOWLY MOVING EAST TOWARDS THE ROCKIES. POTENT EMBEDDED S/WV LIFTING NORTHEAST ACROSS WYOMING. SFC TROUGH CURRENTLY EXTENDS ACROSS THE HIGH PLAINS APPROACHING THE WESTERN DAKOTAS. MOISTURE TRANSPORT RABID THE PAST SEVERAL HOURS WITH A 60KT LOW LEVEL JET HELPING TO INCREASE PWATS FROM AROUND A QUARTER OF AN INCH LAST EVENING UP TO 0.75"-1.00" NOW. FORCING STRONG WITH STEEP THERMAL UPGLIDE EAST OF THE SFC TROUGH ALONG WITH INCREASING UPPER LEVEL DIVERGENCE AS A JET STREAK LIFTS NORTH-NORTHEAST FROM THE CENTRAL ROCKIES TOWARDS THE NORTHERN PLAINS. WIDESPREAD SHOWERS ACROSS THE SOUTHERN HALF OF ND LIFTING NORTH WITH CONTINUED DEVELOPMENT ACROSS NORTHERN SOUTH DAKOTA. EXPANDED SLIGHT CHANCE OF THUNDERSTORMS TO INCLUDE MUCH OF THE WEST AND CENTRAL THIS MORNING. HAVE ALREADY HAD SEVERAL LIGHTNING STRIKES SOUTHWEST WITH A FEW MORE JUST WEST OF WILLISTON OVER NORTHEAST MONTANA. MESOANALYSIS DEPICTS STEEP MID LEVEL LAPSE RATES (10C/KM) OVER THESE AREAS...WITH THE LATEST FEW RUNS OF THE RAP ALSO INDICATING 100-300 CAPE WEST. NEAR TERM HIGH RES MODELS SHOW THIS PLUME OF FAVORABLE MID LEVEL LAPSE RATES AND WEAK CAPE EXPANDING NORTH AND EAST WITH TIME THIS MORNING IN ADDITION TO CONTINUED STRONG FORCING. NOTHING SIGNIFICANT EXPECTED BUT WANTED TO MAKE SURE THUNDERSTORMS WERE IN THE FORECAST THROUGH THE AM. THE MAIN PRECIPITATION BAND IS STILL FORECAST TO LIFT NORTH AND EAST TODAY AS THE SURFACE TROUGH AXIS LIFTS NORTHEAST ACROSS THE STATE. MARGINAL CONVECTIVE PARAMETERS REMAIN OVER THE JAMES RIVER VALLEY THIS AFTERNOON/EARLY EVENING...SO WILL KEEP A MENTION OF SLIGHT CH. OF THUNDERSTORMS THERE...CONSISTENT WITH THE SPC DAY 2 OUTLOOK. PRECIPITATION CHANCES DECREASE OVERNIGHT 06-12Z AS ALL OF WEST AND CENTRAL ND BECOMES DRY SLOTTED. WILL ISSUE A WIND ADVISORY THIS MORNING THROUGH EARLY TO MID AFTERNOON ACROSS THE CENTRAL AND EAST WITH BUFKIT INDICATING 30 TO NEAR 35 KTS OF SUSTAINED WINDS AS THE MIXING HEIGHT ELEVATES AFTER DAYBREAK. OPTED TO START IT NOW AS HAVE ALREADY HAD GUSTS IN EXCESS OF 40 MPH ASSOCIATED WITH THE ONGOING SHOWERS AS THEY MIX SOME OF THE LLJ WINDS TO THE SURFACE. WINDS WILL TAPER OFF WEST TO EAST LATER THIS MORNING INTO THE AFTERNOON AS THE SFC TROUGH ADVANCES EAST. ON THE BACKSIDE OF THE TROUGH...WESTERLY WIND GUSTS TO 40 MPH ARE FORECAST ACROSS THE HIGHER TERRAIN OF THE SOUTHWEST TO DEVELOP THIS AFTERNOON...SO WENT WITH A WIND ADV. THERE AS WELL. FIRE DANGER WILL BE ELEVATED SOUTHWEST DUE TO THE STRONG WINDS AND DECREASING HUMIDITY. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 444 AM CDT WED APR 23 2014 A CLOSED UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN ON THURSDAY WILL MOVE EAST ALONG THE INTERNATIONAL BORDER THROUGH FRIDAY BRINGING SCATTERED SHOWERS TO MAINLY THE FAR NORTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. THE GFS IS THE FARTHEST SOUTH WITH THE TRACK OF THE UPPER LOW...THUS BRINGS THE CHANCE OF PRECIPITATION FARTHER SOUTH ON THURSDAY. USED A COMPROMISE HERE KEEPING THE FAR SOUTHWEST AND SOUTH CENTRAL DRY...AND A BAND OF SLIGHT CHANCE POPS FROM THE WEST CENTRAL INTO THE JAMES RIVER VALLEY...AND HIGHER CHANCE POPS ALONG THE NORTH. DUE TO THE PROXIMITY OF THE UPPER LOW...WILL KEEP A MENTION OF THUNDER ACROSS THE FAR NORTH THURSDAY AFTERNOON. ALSO KEPT A MENTION OF LINGERING RAIN/SNOW SHOWERS ACROSS THE FAR NORTH AND EAST THURSDAY NIGHT AND FRIDAY AS THE UPPER TROUGH LINGERS HERE THROUGH FRIDAY. INDICATIONS ARE THAT WE ARE IN FOR A WET PERIOD OVER THE WEEKEND AND INTO EARLY NEXT WEEK. DETERMINISTIC MODELS ARE IN BETTER AGREEMENT IN CLOSING OFF A STRONG UPPER LEVEL LOW OVER THE CENTRAL/SOUTHERN PLAINS. AN INITIAL WAVE LIFTS THROUGH THE AREA ON SATURDAY WITH THE BRUNT OF THE PRECIPITATION ARRIVING SUNDAY AND CONTINUING THROUGH MONDAY. ONE SIGNIFICANT DIFFERENCE BETWEEN THE GFS COMPARED TO THE ECMWF/GEM IS THE ORIENTATION OF THE DOWNSTREAM BLOCKING RIDGE. A GFS SOLUTION KEEPS A SHARPER RIDGE AHEAD OF THE LOW THUS SOUTHERLY FLOW REMAINS OVER THE AREA UNTIL LATE MONDAY. THEREFORE PRECIPITATION WOULD FALL AS ALL RAIN. A ECMWF /GEM SOLUTION DEPICTS A COLDER EAST TO NORTHEAST FLOW THROUGH THE ENTIRE EVENT. THUS A BETTER CHANCE OF MIXED RAIN AND SNOW OR ALL SNOW...ESPECIALLY DURING THE OVERNIGHT AND EARLY MORNING HOURS SUNDAY THROUGH MONDAY. WE DRY OUT TUESDAY AND WEDNESDAY BUT REMAIN COOL BEHIND THE EXITING LOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 642 AM CDT WED APR 23 2014 WINDY CONDITIONS WILL CONTINUE WITH A SOUTHEAST WIND GUSTING OVER 30 KTS AT TIMES. WINDS WILL SUBSIDE FROM WEST TO EAST LATER THIS MORNING AND AFTERNOON. HOWEVER...A GUSTY WESTERLY WIND WILL DEVELOP ACROSS WESTERN NORTH DAKOTA AFTER 18Z THROUGH THE AFTERNOON. SHOWERS AND A SLIGHT CHANCE FOR THUNDERSTORMS WILL CONTINUE THIS MORNING...WITH ADDITIONAL SHOWERS WEDNESDAY AFTERNOON/EVENING. CIGS/VIS GENERALLY VFR...BUT CANNOT RULE OUT PERIODS OF MVFR CIGS/VIS IN ANY HEAVIER SHOWER. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 1 PM CDT /NOON MDT/ THIS AFTERNOON FOR NDZ003-011-020>022-034>036-042-045>047-050. WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR NDZ004-005-012- 013-023-025-037-048-051. WIND ADVISORY FROM NOON TODAY TO 6 PM MDT THIS EVENING FOR NDZ040-041-043-044. && $$ UPDATE...TM SHORT TERM...NH LONG TERM...TWH AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 AM CDT WED APR 23 2014 .UPDATE... ISSUED AT 642 AM CDT WED APR 23 2014 NO SIGNIFICANT UPDATES TO THE GOING FORECAST THIS MORNING. SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO LIFT NORTHEAST THROUGH WESTERN AND CENTRAL NORTH DAKOTA. A TIGHT PRESSURE GRADIENT WILL MOVE OVER CENTRAL NORTH DAKOTA THIS MORNING AS THE GRADIENT WEAKENS IN THE WEST WITH LOW PRESSURE MOVING INTO THIS AREA DURING THE MORNING. UPDATED LATEST SENSIBLE WEATHER GRIDS. UPDATED TEXT PRODUCTS WILL BE SENT SHORTLY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 444 AM CDT WED APR 23 2014 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CONTINUED GUSTY WINDS THIS MORNING AND AFTERNOON...PRECIPITATION CHANCES AND AMOUNTS TODAY AND TONIGHT...AND THUNDERSTORM CHANCES (NON- SEVERE) MOST LOCATIONS. CURRENTLY...UPPER LEVEL TROUGH EXTENDING FROM THE PACIFIC NORTHWEST SOUTHEAST INTO THE DESERT SOUTHWEST BECOMING NEGATIVELY TILTED AND SLOWLY MOVING EAST TOWARDS THE ROCKIES. POTENT EMBEDDED S/WV LIFTING NORTHEAST ACROSS WYOMING. SFC TROUGH CURRENTLY EXTENDS ACROSS THE HIGH PLAINS APPROACHING THE WESTERN DAKOTAS. MOISTURE TRANSPORT RABID THE PAST SEVERAL HOURS WITH A 60KT LOW LEVEL JET HELPING TO INCREASE PWATS FROM AROUND A QUARTER OF AN INCH LAST EVENING UP TO 0.75"-1.00" NOW. FORCING STRONG WITH STEEP THERMAL UPGLIDE EAST OF THE SFC TROUGH ALONG WITH INCREASING UPPER LEVEL DIVERGENCE AS A JET STREAK LIFTS NORTH-NORTHEAST FROM THE CENTRAL ROCKIES TOWARDS THE NORTHERN PLAINS. WIDESPREAD SHOWERS ACROSS THE SOUTHERN HALF OF ND LIFTING NORTH WITH CONTINUED DEVELOPMENT ACROSS NORTHERN SOUTH DAKOTA. EXPANDED SLIGHT CHANCE OF THUNDERSTORMS TO INCLUDE MUCH OF THE WEST AND CENTRAL THIS MORNING. HAVE ALREADY HAD SEVERAL LIGHTNING STRIKES SOUTHWEST WITH A FEW MORE JUST WEST OF WILLISTON OVER NORTHEAST MONTANA. MESOANALYSIS DEPICTS STEEP MID LEVEL LAPSE RATES (10C/KM) OVER THESE AREAS...WITH THE LATEST FEW RUNS OF THE RAP ALSO INDICATING 100-300 CAPE WEST. NEAR TERM HIGH RES MODELS SHOW THIS PLUME OF FAVORABLE MID LEVEL LAPSE RATES AND WEAK CAPE EXPANDING NORTH AND EAST WITH TIME THIS MORNING IN ADDITION TO CONTINUED STRONG FORCING. NOTHING SIGNIFICANT EXPECTED BUT WANTED TO MAKE SURE THUNDERSTORMS WERE IN THE FORECAST THROUGH THE AM. THE MAIN PRECIPITATION BAND IS STILL FORECAST TO LIFT NORTH AND EAST TODAY AS THE SURFACE TROUGH AXIS LIFTS NORTHEAST ACROSS THE STATE. MARGINAL CONVECTIVE PARAMETERS REMAIN OVER THE JAMES RIVER VALLEY THIS AFTERNOON/EARLY EVENING...SO WILL KEEP A MENTION OF SLIGHT CH. OF THUNDERSTORMS THERE...CONSISTENT WITH THE SPC DAY 2 OUTLOOK. PRECIPITATION CHANCES DECREASE OVERNIGHT 06-12Z AS ALL OF WEST AND CENTRAL ND BECOMES DRY SLOTTED. WILL ISSUE A WIND ADVISORY THIS MORNING THROUGH EARLY TO MID AFTERNOON ACROSS THE CENTRAL AND EAST WITH BUFKIT INDICATING 30 TO NEAR 35 KTS OF SUSTAINED WINDS AS THE MIXING HEIGHT ELEVATES AFTER DAYBREAK. OPTED TO START IT NOW AS HAVE ALREADY HAD GUSTS IN EXCESS OF 40 MPH ASSOCIATED WITH THE ONGOING SHOWERS AS THEY MIX SOME OF THE LLJ WINDS TO THE SURFACE. WINDS WILL TAPER OFF WEST TO EAST LATER THIS MORNING INTO THE AFTERNOON AS THE SFC TROUGH ADVANCES EAST. ON THE BACKSIDE OF THE TROUGH...WESTERLY WIND GUSTS TO 40 MPH ARE FORECAST ACROSS THE HIGHER TERRAIN OF THE SOUTHWEST TO DEVELOP THIS AFTERNOON...SO WENT WITH A WIND ADV. THERE AS WELL. FIRE DANGER WILL BE ELEVATED SOUTHWEST DUE TO THE STRONG WINDS AND DECREASING HUMIDITY. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 444 AM CDT WED APR 23 2014 A CLOSED UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN ON THURSDAY WILL MOVE EAST ALONG THE INTERNATIONAL BORDER THROUGH FRIDAY BRINGING SCATTERED SHOWERS TO MAINLY THE FAR NORTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. THE GFS IS THE FARTHEST SOUTH WITH THE TRACK OF THE UPPER LOW...THUS BRINGS THE CHANCE OF PRECIPITATION FARTHER SOUTH ON THURSDAY. USED A COMPROMISE HERE KEEPING THE FAR SOUTHWEST AND SOUTH CENTRAL DRY...AND A BAND OF SLIGHT CHANCE POPS FROM THE WEST CENTRAL INTO THE JAMES RIVER VALLEY...AND HIGHER CHANCE POPS ALONG THE NORTH. DUE TO THE PROXIMITY OF THE UPPER LOW...WILL KEEP A MENTION OF THUNDER ACROSS THE FAR NORTH THURSDAY AFTERNOON. ALSO KEPT A MENTION OF LINGERING RAIN/SNOW SHOWERS ACROSS THE FAR NORTH AND EAST THURSDAY NIGHT AND FRIDAY AS THE UPPER TROUGH LINGERS HERE THROUGH FRIDAY. INDICATIONS ARE THAT WE ARE IN FOR A WET PERIOD OVER THE WEEKEND AND INTO EARLY NEXT WEEK. DETERMINISTIC MODELS ARE IN BETTER AGREEMENT IN CLOSING OFF A STRONG UPPER LEVEL LOW OVER THE CENTRAL/SOUTHERN PLAINS. AN INITIAL WAVE LIFTS THROUGH THE AREA ON SATURDAY WITH THE BRUNT OF THE PRECIPITATION ARRIVING SUNDAY AND CONTINUING THROUGH MONDAY. ONE SIGNIFICANT DIFFERENCE BETWEEN THE GFS COMPARED TO THE ECMWF/GEM IS THE ORIENTATION OF THE DOWNSTREAM BLOCKING RIDGE. A GFS SOLUTION KEEPS A SHARPER RIDGE AHEAD OF THE LOW THUS SOUTHERLY FLOW REMAINS OVER THE AREA UNTIL LATE MONDAY. THEREFORE PRECIPITATION WOULD FALL AS ALL RAIN. A ECMWF /GEM SOLUTION DEPICTS A COLDER EAST TO NORTHEAST FLOW THROUGH THE ENTIRE EVENT. THUS A BETTER CHANCE OF MIXED RAIN AND SNOW OR ALL SNOW...ESPECIALLY DURING THE OVERNIGHT AND EARLY MORNING HOURS SUNDAY THROUGH MONDAY. WE DRY OUT TUESDAY AND WEDNESDAY BUT REMAIN COOL BEHIND THE EXITING LOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 642 AM CDT WED APR 23 2014 WINDY CONDITIONS WILL CONTINUE WITH A SOUTHEAST WIND GUSTING OVER 30 KTS AT TIMES. WINDS WILL SUBSIDE FROM WEST TO EAST LATER THIS MORNING AND AFTERNOON. HOWEVER...A GUSTY WESTERLY WIND WILL DEVELOP ACROSS WESTERN NORTH DAKOTA AFTER 18Z THROUGH THE AFTERNOON. SHOWERS AND A SLIGHT CHANCE FOR THUNDERSTORMS WILL CONTINUE THIS MORNING...WITH ADDITIONAL SHOWERS WEDNESDAY AFTERNOON/EVENING. CIGS/VIS GENERALLY VFR...BUT CANNOT RULE OUT PERIODS OF MVFR CIGS/VIS IN ANY HEAVIER SHOWER. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 1 PM CDT /NOON MDT/ THIS AFTERNOON FOR NDZ003-011-020>022-034>036-042-045>047-050. WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR NDZ004-005-012- 013-023-025-037-048-051. WIND ADVISORY FROM NOON TODAY TO 6 PM MDT THIS EVENING FOR NDZ040-041-043-044. && $$ UPDATE...TWH SHORT TERM...NH LONG TERM...TWH AVIATION...NH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1116 AM EDT WED APR 23 2014 .SYNOPSIS... HIGH PRESSURE AND COOLER WEDNESDAY. DRY WARM FRONT THURSDAY. A WEAK COLD FRONT CROSSES THE AREA FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... 11AM UPDATE... FORECAST HAS NOT CHANGED MUCH FROM THE PREVIOUS FORECAST. STRATUS DECK HAS BEEN HOLDING FAIRLY STEADY OVER THE NORTHERN COUNTIES BUT HAS BEGUN TO BREAK UP ALONG THE SOUTHERN EDGE AS MIXING GETS GOING. OLD BELOW... NORTHWEST FLOW CREATING A STRATUS DECK OVER THE NORTHERN COUNTIES THIS MORNING. MODELS HANDLE THIS MOISTURE CONSIDERABLY DIFFERENTLY TODAY WHEN MIXING STARTS OCCURRING. RUC SHOWS IT QUICKLY MIXING OUT WHILE THE NAM AND GFS HOLD ONTO CUMULUS WELL INTO CENTRAL WV. WENT MORE TOWARD THE RUC FOR NOW...BUT CONFIDENCE IS LOW. WITH A NORTHWEST FLOW CONTINUING TODAY...WENT TOWARD THE COOLER MOS GUIDANCE FOR HIGHS. WINDS SHOULD DECOUPLE TONIGHT...ALLOWING FOR SOME GOOD RADIATION. BIG QUESTION IS HOW QUICKLY CLOUDS FROM THE WARM FRONT PUSH INTO THE AREA. THIS BECOMES EXTRA IMPORTANT DUE TO THE POSSIBILITY OF FREEZING TEMPERATURES IF THERE IS ENOUGH CLOUD FREE TIME AFTER WINDS LAY DOWN. WILL GO WITH A FREEZE WATCH ACROSS THE NORTHERN COUNTIES WHERE COLDEST TEMPERATURES ARE EXPECTED...BUT OUTLYING AREAS JUST SOUTH OF THE FREEZE WATCH ARE NOT NECESSARILY SAFE...DEPENDING ON CLOUD TIMING. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... MODELS IN GENERAL AGREEMENT THIS PERIOD. HIGH PRESSURE WILL BE LOCATED OVER THE AREA EARLY THURSDAY. HOWEVER...HIGH WILL SLIDE EAST...ALLOWING A WARM FRONT TO DEVELOP/PUSH INTO THE AREA BY THURSDAY AFTERNOON. THIS FRONT WILL PUSH NORTH THURSDAY NIGHT. LATEST GUIDANCE ACTUALLY INDICATES AIRMASS WILL BE DRIER THAN OUR PREVIOUS FORECAST INDICATED. APPEARS THIS IS THE RESULT OF A SLOWER MOVEMENT OF THE WARM FRONT. HAVE TWEAKED DEWPOINTS DOWN QUITE A BIT...ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE REGION. WITH AIRMASS REMAINING DRY INVOF THIS FEATURE...ONLY EXPECT AN INCREASE IN CLOUDS. A COLD FRONT IS THEN PROGGED TO PUSH EAST ACROSS THE REGION LATE THURSDAY NIGHT INTO FRIDAY. LATEST GUIDANCE IS A LITTLE SLOWER WITH THE FRONT...AND HAVE TWEAKED POP AND WEATHER GRIDS TO REFLECT THIS TREND. NOT MUCH...IF ANY...INSTABILITY ALONG/AHEAD OF FRONT. BUT NAM DOES SHOW A LITTLE. WITH PREVIOUS FORECAST INDICATING SLIGHT CHANCE THUNDER...HAVE DECIDED TO KEEP IT IN PLACE. WEAK HIGH PRESSURE SHOULD NOSE IN FROM THE SOUTHWEST FRIDAY AFTERNOON...BRINGING PRECIP CHANCES TO END. MODELS HAVE BEEN CONSISTENT PUSHING A WEAK COLD FRONT SOUTHEAST LATE FRIDAY NIGHT INTO SATURDAY. HAVE MAINTAINED LOW POPS WITH THIS FEATURE. LATEST MAV NUMBERS FOR HIGHS ON THURSDAY WERE CLOSE TO PREVIOUS FORECAST NUMBERS...WITH THE MET NUMBERS LOWER. MET NUMBERS APPEAR TO BE ON THE COOL SIDE...SO HAVE LEANED TOWARDS THE MAV NUMBERS. STILL NOT SURE ABOUT LOWS THURSDAY NIGHT. WITH SOUTHERLY WINDS AND INCREASING LOW-LEVEL MOISTURE...EXPECT TEMPS WILL REMAIN UP AND HAVE AGAIN LEANED TOWARD MAV NUMBERS. BUT WOULD NOT BE TOO SURPRISED TO SEE LOWS SLIP BELOW OUR FORECASTED VALUES. CURRENT THINKING IS THAT MAV NUMBERS ALSO LOOK BEST FOR HIGHS ON FRIDAY...AS LITTLE IN THE WAY OF COOLING IS INDICATED BEHIND THE FRONT. MEX NUMBERS WERE USED TO TWEAK PREVIOUS NUMBERS FOR LOWS FRIDAY NIGHT AND HIGHS ON SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... THE FRONT COULD STALL SOUTH OF THE AREA DURING THE WEEKEND BEFORE LIFTING NORTH AS A WARM FRONT SUNDAY AND MONDAY FOR ADDITIONAL PCPN MAINLY EXTREME SOUTHERN WV. USED HPC GUIDE FOR TEMPERATURES AND DEWPOINTS WITH FEW TWEAKS DOWN ON HIGHS THROUGH THE PERIODS. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... 15Z UPDATE... STRATOCU DECK HAS HUNG ON OVER NORTHERASTERN WV AND MOVED ACROSS NORTHERN WV AND EAST CENTRAL OHIO. GENERALLY STAYING VFR EVEN IN THE CLOUDS...WITH SOME MVFR CONDITIONS OCCURRING. CLOUDS ARE BEGINNING TO BREAK UP AND DISSIPATE AS MIXING BEGINS. OLD BELOW... A STRATUS DECK OVER NORTHEASTERN WV...SCATTERING WESTWARD ACROSS NORTHERN WV AND EAST CENTRAL OHIO...MAY CAUSE SOME MVFR CONDITIONS THIS MORNING. THIS DECK SHOULD TURN INTO A CUMULUS DECK AND DISSIPATE TODAY AS THE SUN MIXES THE ATMOSPHERE. VFR CONDITIONS CAN THEN BE EXPECTED...EVEN THOUGH SOME CLOUDS FROM A WARM FRONT WILL BE ARRIVING LATE TONIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY... FORECAST CONFIDENCE: HIGH. ALTERNATE SCENARIOS: TIMING OF THE CLOUD DECK IN THE NORTH DISSIPATING COULD VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z THURSDAY... NO IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR WVZ008>011-016>020-027>032. OH...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR OHZ066-067-075-076-085. KY...NONE. VA...NONE. && $$ SYNOPSIS...JSH/RPY NEAR TERM...RPY/LS SHORT TERM...JSH LONG TERM...ARJ AVIATION...RPY/LS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
608 AM EDT WED APR 23 2014 .SYNOPSIS... HIGH PRESSURE AND COOLER WEDNESDAY. DRY WARM FRONT THURSDAY. A WEAK COLD FRONT CROSSES THE AREA FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... NORTHWEST FLOW CREATING A STRATUS DECK OVER THE NORTHERN COUNTIES THIS MORNING. MODELS HANDLE THIS MOISTURE CONSIDERABLY DIFFERENTLY TODAY WHEN MIXING STARTS OCCURRING. RUC SHOWS IT QUICKLY MIXING OUT WHILE THE NAM AND GFS HOLD ONTO CUMULUS WELL INTO CENTRAL WV. WENT MORE TOWARD THE RUC FOR NOW...BUT CONFIDENCE IS LOW. WITH A NORTHWEST FLOW CONTINUING TODAY...WENT TOWARD THE COOLER MOS GUIDANCE FOR HIGHS. WINDS SHOULD DECOUPLE TONIGHT...ALLOWING FOR SOME GOOD RADIATION. BIG QUESTION IS HOW QUICKLY CLOUDS FROM THE WARM FRONT PUSH INTO THE AREA. THIS BECOMES EXTRA IMPORTANT DUE TO THE POSSIBILITY OF FREEZING TEMPERATURES IF THERE IS ENOUGH CLOUD FREE TIME AFTER WINDS LAY DOWN. WILL GO WITH A FREEZE WATCH ACROSS THE NORTHERN COUNTIES WHERE COLDEST TEMPERATURES ARE EXPECTED...BUT OUTLYING AREAS JUST SOUTH OF THE FREEZE WATCH ARE NOT NECESSARILY SAFE...DEPENDING ON CLOUD TIMING. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... MODELS IN GENERAL AGREEMENT THIS PERIOD. HIGH PRESSURE WILL BE LOCATED OVER THE AREA EARLY THURSDAY. HOWEVER...HIGH WILL SLIDE EAST...ALLOWING A WARM FRONT TO DEVELOP/PUSH INTO THE AREA BY THURSDAY AFTERNOON. THIS FRONT WILL PUSH NORTH THURSDAY NIGHT. LATEST GUIDANCE ACTUALLY INDICATES AIRMASS WILL BE DRIER THAN OUR PREVIOUS FORECAST INDICATED. APPEARS THIS IS THE RESULT OF A SLOWER MOVEMENT OF THE WARM FRONT. HAVE TWEAKED DEWPOINTS DOWN QUITE A BIT...ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE REGION. WITH AIRMASS REMAINING DRY INVOF THIS FEATURE...ONLY EXPECT AN INCREASE IN CLOUDS. A COLD FRONT IS THEN PROGGED TO PUSH EAST ACROSS THE REGION LATE THURSDAY NIGHT INTO FRIDAY. LATEST GUIDANCE IS A LITTLE SLOWER WITH THE FRONT...AND HAVE TWEAKED POP AND WEATHER GRIDS TO REFLECT THIS TREND. NOT MUCH...IF ANY...INSTABILITY ALONG/AHEAD OF FRONT. BUT NAM DOES SHOW A LITTLE. WITH PREVIOUS FORECAST INDICATING SLIGHT CHANCE THUNDER...HAVE DECIDED TO KEEP IT IN PLACE. WEAK HIGH PRESSURE SHOULD NOSE IN FROM THE SOUTHWEST FRIDAY AFTERNOON...BRINGING PRECIP CHANCES TO END. MODELS HAVE BEEN CONSISTENT PUSHING A WEAK COLD FRONT SOUTHEAST LATE FRIDAY NIGHT INTO SATURDAY. HAVE MAINTAINED LOW POPS WITH THIS FEATURE. LATEST MAV NUMBERS FOR HIGHS ON THURSDAY WERE CLOSE TO PREVIOUS FORECAST NUMBERS...WITH THE MET NUMBERS LOWER. MET NUMBERS APPEAR TO BE ON THE COOL SIDE...SO HAVE LEANED TOWARDS THE MAV NUMBERS. STILL NOT SURE ABOUT LOWS THURSDAY NIGHT. WITH SOUTHERLY WINDS AND INCREASING LOW-LEVEL MOISTURE...EXPECT TEMPS WILL REMAIN UP AND HAVE AGAIN LEANED TOWARD MAV NUMBERS. BUT WOULD NOT BE TOO SURPRISED TO SEE LOWS SLIP BELOW OUR FORECASTED VALUES. CURRENT THINKING IS THAT MAV NUMBERS ALSO LOOK BEST FOR HIGHS ON FRIDAY...AS LITTLE IN THE WAY OF COOLING IS INDICATED BEHIND THE FRONT. MEX NUMBERS WERE USED TO TWEAK PREVIOUS NUMBERS FOR LOWS FRIDAY NIGHT AND HIGHS ON SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... THE FRONT COULD STALL SOUTH OF THE AREA DURING THE WEEKEND BEFORE LIFTING NORTH AS A WARM FRONT SUNDAY AND MONDAY FOR ADDITIONAL PCPN MAINLY EXTREME SOUTHERN WV. USED HPC GUIDE FOR TEMPERATURES AND DEWPOINTS WITH FEW TWEAKS DOWN ON HIGHS THROUGH THE PERIODS. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... A STRATUS DECK OVER NORTHEASTERN WV...SCATTERING WESTWARD ACROSS NORTHERN WV AND EAST CENTRAL OHIO...MAY CAUSE SOME MVFR CONDITIONS THIS MORNING. THIS DECK SHOULD TURN INTO A CUMULUS DECK AND DISSIPATE TODAY AS THE SUN MIXES THE ATMOSPHERE. VFR CONDITIONS CAN THEN BE EXPECTED...EVEN THOUGH SOME CLOUDS FROM A WARM FRONT WILL BE ARRIVING LATE TONIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY... FORECAST CONFIDENCE: HIGH. ALTERNATE SCENARIOS: TIMING OF THE CLOUD DECK IN THE NORTH DISSIPATING COULD VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22 EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY L L H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z THURSDAY... NO IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR WVZ008>011-016>020-027>032. OH...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR OHZ066-067-075-076-085. KY...NONE. VA...NONE. && $$ SYNOPSIS...JSH/RPY NEAR TERM...RPY/JW SHORT TERM...JSH LONG TERM...ARJ AVIATION...RPY Area Forecast Discussion National Weather Service Spokane WA 440 AM PDT WED APR 23 2014 .SYNOPSIS... Occasional precipitation chances, breezy conditions and relatively cool temperatures dominate the weather pattern. Passing rain and snow chances Wednesday are followed by steadier rain chances late Wednesday night into Thursday, followed by a threat of more scattered showers, and perhaps some thunder, Thursday afternoon. Showers will remain a threat into the weekend, before a relative lull comes for the start of the new work week. && .DISCUSSION... Today and tonight: A threat of rain and snow showers returns to the Inland NW today, while steadier rain develops late tonight. This morning a tight 500mb shortwave was entering the Cascades, with weak 850-700mb theta-e ridge leading it into central and eastern WA and north ID. That latter feature will provide focus for the moisture and increasing precipitation across the Cascade crest and the Okanogan to Upper Columbia Basin, spreading into the eastern third of WA and north ID this morning. There is some disagreement in how quickly precipitation develops or how widespread it will actually be. The HRRR actually shows very little in that way of significant precipitation; however the GFS/NAM/EC/SREF are more generous. At 930Z clouds were starting to thicken near the Cascades and expand east, while a few light radar returns were developing east of Othello. I don`t see any evidence that anything is actually reaching the ground at this time, but leaning toward the more dominant model solutions suggest this will change. So I gradually increase PoPs to likely through the morning, especially across southeast WA to the central Panhandle. For late this morning to early afternoon the 500mb shortwave comes on the heels of the 850/700mb wave, before shifting into Montana in the late afternoon. With 500mb temperatures in the core of this disturbance in the -25 to -31 C range and a swath of 100-200 J/kg of CAPE and marginally negative LI values, this will mean a continued shower threat across the eastern third of of WA and north ID this afternoon, before dissipating in coverage by early evening. I included a slight chance of thunder toward the northeast mountains, but even then I think any thunder that develops would be more isolated in nature, if any develops at all. Looking at current wet-bulb zero heights and regional temperatures, the precipitation will have a modest opportunity to fall as snow across a large portion of the region, save for the lower Palouse to the deeper Columbia Basin and the L-C valley. The threat for more than an inch of snow, however, will remains toward the Cascades and the Panhandle Mountains, and perhaps toward the higher Idaho Palouse. The threat for accumulating snow outside of the mountains will also be limited to early in the day. However the convective or unstable nature of the atmosphere under the trough will mean the potential for a rain/snow/graupel/small hail mix with any showers that occur into the afternoon. Late tonight into Thursday morning a warm front comes in from the southwest. This will shift the region to more stable regime. Strengthening isentropic ascent and subtropical moisture plume come the warm front as the night wares on. PWATs rise to between 0.50 to 0.75 inches (or ~150-200% of normal). This favors another swath of precipitation, enveloping much of the region from the Columbia Basin toward the northern mountains between 04Z-11Z (or ~9 PM to 4 AM). I increased precipitation chances to likely for a large portion of the region going past 06Z. By this time the milder air surges in, pushing wet-bulb zero heights and snow levels up toward 3500-4000 feet around the mountains of northeast WA and north ID and to around 4500 to 5500 feet elsewhere. In other words the next system looks to be more of a valley rain and high mountain snow event. /J. Cote` Thursday through Friday...Chances are very good that the recent spurt of wet weather will continue through this period as well. The latest water vapor and shows a developing baroclinic band near 150w with a nice tap into sub-tropical moisture per the blended precipitable water product. Models in very good agreement that this atmospheric river will slide into SW Washington Wednesday night and gradually spread northeast through Thursday morning in the form of a warm front. Precipitation will likely impact most locations...including the lee of the Cascades due to moderate isentropic ascent resultant of the mid-level southwest winds. Most of the stratiform precipitation will fall in the morning...as the atmospheric river is expected to shift east of the region by afternoon. Before it shifts east most of the region will see measurable rainfall with amounts ranging from .20 to .40 inches over most valley locations...with heavier amounts over the mountains of north Idaho and the Cascade Crest. This bout of rain will be followed by a weak negatively tilted trough during the afternoon...somewhat similar to yesterday. Whether or not the moisture from the morning rain can combine with afternoon heating to produce deep convection and possible thunderstorms is the question. Yesterdays window of opportunity was too short to tap into the moisture and thus we never saw thunderstorms. The Thursday setup isn`t ideal but it should be a little better than what we saw. Thus we will continue to mention a chance of afternoon and early evening thunderstorms. The best chances will occur east of a line from Republic to Ritzville. Model instability isn`t supportive of any strong convection as the CAPE values are too low for strong updrafts. The threat of thunder will wane Thursday evening...and most of the area will see a brief drying trend...with one exception. The upper level trough responsible delivering the atmospheric river will shift onto the Washington coast by morning...which is expected to send a shortwave trough in from the southwest. All the models are showing a similar scenario...with the track of the shortwave expected to impact the southeast corner of Washington into NC Idaho...due to the proximity of a low-level theta-e ridge axis. Moderate rainfall amounts will be possible in this region with locations such as Lewiston...Pullman...and the Silver Valley seeing the possibility of up to a quarter inch. Across the remainder of the forecast area the possibility of significant rainfall is considerably lower. That notion will likely continue until afternoon at which time the upper level trough will likely shift into the Cascades. This should result in diurnally developing convection...however lapse rates aren`t really all that impressive. Most of the convection will likely fire over the mountains due to terrain forcing. Friday night through Monday...The upper level trough or some semblances of it will likely remain fixed over the Pacific Northwest through this period as well. There are no signs of seeing a good fetch of moisture...or strong synoptic forcing at least through the weekend. So we are primarily looking at an unsettled weather pattern with generally diurnally driven shower activity. Most of the convection will fire near the Cascades and the Idaho Panhandle. By Monday there is some support for a weak shortwave ridge. This should lead to slightly drier weather but based on the amplitude of the ridge...we don`t want to go completely dry. fx Monday Night through Wednesday: The extended part of the forecast which yesterday featured an amplifying ridge, now has gained some uncertainty. Most recent GFS model runs now have the ridge sliding further to the east over MT allowing the offshore trough to advect an abundance of subtropical moisture into our region leading to increased chances for more precipitation. While the GFS has trended wetter, the Euro still advertises the ridge remaining entrenched right over our area keeping the storm track to the west. This would lead to the dry conditions the models were showing yesterday. Due to the model uncertainty I did increase POPs slightly to include the mention of showers for higher elevation locations along with the eastern third of WA and the Panhandle. Confidence is not high with this change, but thought it would be worthwhile to at least move POPs towards climo for the time being. Other than POPs, not many changes were made to the period due to lower confidence. Many factors for this portion of the forecast will depend on the verifying model and will have to be fine tuned once model agreement is better. Given the models right now, the active GFS would bring continued wet conditions with below normal temps while Euro would bring above normal temps and drier conditions. For the time being we will just have to wait and see how the models trend over the next few runs. /Fliehman && .AVIATION... 12Z TAFS: Two systems will impact the Inland NW aviation interests over the next 24 hours. An unstable upper wave will track across east WA/north ID this morning and afternoon, bringing scattered showers. Chances will be best over the eastern TAF sites (GEG to COE and PUW/LWS). Some light snow may be mixed as well, especially in the morning. The afternoon may also bring a few thunderstorms, but the best threat will remain north and east of TAF sites. LCL MVFR/isolated IFR cigs are possible with showers, especially in the morning. In addition to precipitation, look for breezy conditions in the afternoon. The threat of precipitation lulls for the late afternoon/early evening, however the next system will begin to move in late this evening and overnight in the form of a warm front that is expected to lead to steader rain developing from the south/southwest, after 03-06Z. LCL MVFR cigs will be possible by this time frame too. /J. Cote` && .PRELIMINARY POINT TEMPS/POPS... Spokane 51 39 55 38 54 37 / 80 70 100 40 40 20 Coeur d`Alene 50 38 53 37 53 37 / 80 60 100 70 50 20 Pullman 50 41 54 39 50 37 / 80 70 100 50 50 20 Lewiston 56 45 60 44 55 42 / 60 50 100 60 70 20 Colville 57 35 59 35 61 36 / 50 50 100 60 40 20 Sandpoint 49 36 51 36 54 37 / 70 50 100 80 50 30 Kellogg 45 36 50 36 52 36 / 80 60 100 70 70 40 Moses Lake 61 44 65 40 61 38 / 20 70 70 10 10 20 Wenatchee 60 45 64 43 61 41 / 20 60 70 10 10 20 Omak 59 39 62 36 62 35 / 20 50 80 10 20 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
507 PM CDT WED APR 23 2014 .DISCUSSION... 310 PM CDT SYNOPSIS...ANOTHER PLEASANT DAY TODAY...BUT SHOWERS MOVE IN FROM THE WEST THIS EVENING. SHOWERS AND STORMS ARE EXPECTED TOMORROW AFTERNOON AND EVENING WITH A DRY AND WARM END TO THE WORK WEEK. THIS WEEKEND LOOKS TO HAVE BELOW NORMAL TEMPERATURES WITH SHOWERS AND PERHAPS SOME THUNDERSTORMS ALONG AND SOUTH OF I-80 FOR THE FIRST HALF OF NEXT WEEK. REST OF TODAY AND TONIGHT... A LARGE UPPER LEVEL RIDGE IS OVER THE CENTRAL PLAINS WHILE A SURFACE HIGH IS CENTERED OVER LAKE MICHIGAN. THE RIDGE PASSES OVERHEAD TONIGHT WHILE THE SURFACE HIGH PUSHES EAST TO THE NORTHERN OHIO VALLEY THROUGH EASTERN QUEBEC. A WEAK SHORTWAVE IS OVER EASTERN NEBRASKA AND WESTERN IOWA WITH SHOWERS OVER WESTERN IOWA. THE SHOWERS WILL CONTINUE TO PUSH EAST...BUT WITH DEWPOINT DEPRESSIONS AT 20+ DEGREES...THINKING THE SHOWERS WILL DISSIPATE A BIT BEFORE MOVING INTO CENTRAL IL. AS SUCH THINKING THE FIRST SHOWERS WILL ENTER THE FAR EASTERN CWA AFTER 5PM CST. USED THE LOCAL ARW...RAP...AND HRRR TO CREATE THE POPS FOR THE REST OF TODAY AND TONIGHT. THINKING A BAND OF SCATTERED SHOWERS WILL SLOWLY CROSS NORTHERN IL THIS EVENING IN ASSOCIATION WITH AN UPPER LEVEL VORTICITY STREAMER. THE BEST COVERAGE WILL BE BETWEEN MIDNIGHT AND 4 AM CST WITH A CHANCE OF LIGHT RAIN SHOWERS NORTH OF I-80. THE BAND THEN LIFTS NORTH EARLY THURSDAY MORNING AS THE RIDGE MOVES DIRECTLY OVERHEAD. NOT EXPECTING ANY SIGNIFICANT PRECIP ACCUMULATIONS. CLOUD COVER WILL INCREASE THROUGH THIS AFTERNOON AND LOOKING AT MIN TEMPS IN THE UPPER 30S TO MID 40S ACROSS THE CWA. TOMORROW AND TOMORROW NIGHT... AN UPPER LEVEL TROUGH MOVES OVER THE PLAINS TOMORROW MORNING AND THE TROUGH PASSES OVER THE REGION TOMORROW NIGHT. THE UPPER LEVEL LOW ASSOCIATED WITH THE TROUGH PASSES FARTHER NORTH...ALONG THE US/CANADA BORDER. THE SURFACE LOW ALSO BEGINS OVER THE PLAINS THURSDAY MORNING AND THEN MOVES OVER IL THURSDAY EVENING. GUIDANCE HAS THE LOW PROGRESSING A BIT SLOWER AND MADE THE NECESSARY ADJUSTMENTS. RAIN AND SOME STORMS MOVE IN FROM THE WEST THROUGH THE MORNING AND EARLY AFTERNOON. INSTABILITY IS NOT EXTREMELY IMPRESSIVE WITH THE SYSTEM SO KEPT ONLY A CHANCE OF THUNDER. QPF AMOUNTS ON THE OTHER HAND COULD BE IMPRESSIVE WITH TOTALS AROUND A HALF INCH OF RAIN. WINDS WILL ALSO BE SHIFTING FROM SOUTHEAST IN THE MORNING TO OUT OF THE WEST OVERNIGHT BEHIND THE LOW. LOOKING AT A BREEZY AFTERNOON WITH SOUTH WINDS GUSTING TO 35 MPH. THE AMPLE WAA WILL LEAD TO MAX TEMPS FROM AROUND 60 ALONG THE IL/WI BORDER TO THE UPPER 60S IF NOT 70 IN THE SOUTHERN CWA. FRIDAY AND SATURDAY... THE UPPER LEVEL LOW CONTINUES TO SHIFT EAST REACHING NEW ENGLAND BY SATURDAY AFTERNOON/EVENING. THE SURFACE LOW SHIFTS EAST AND EXPECTING PRECIP TO COME TO AN END EARLY FRIDAY MORNING. WEST WINDS WILL BE GUSTING TO ARND 30 MPH FRIDAY AND AM THINKING THERE COULD BE SOME DRY AIR MIXING DOWN TO THE SURFACE SO LOWERED DEWPOINTS A BIT. THE AIR BEHIND THE COLD FRONT IS NOT REALLY ALL THAT COLD SINCE MAX TEMPS ON FRIDAY LOOK TO BE AROUND 70 DEGREES. A BACK DOOR COLD FRONT SLIDES DOWN FROM THE NORTH IN THE EVENING. SOME GUIDANCE MEMBERS FEATURE A BAND OF PRECIP FORMING AHEAD OF THE FRONT OVER FAR NORTHERN IL AND NW INDIANA. PUT IN A CHANCE OF PRECIP SINCE FORCING LOOKS GOOD...BUT HAVE LOW CONFIDENCE IN THE BAND OF PRECIP ACTUALLY FORMING. AS SUCH KEPT POPS IN THE CHANCE RANGE. WINDS TURN NORTHEAST BEHIND THE FRONT AND OVERNIGHT LOWS WILL BE IN THE UPPER 30S TO MID 40S. SOME GUIDANCE MEMBERS KEEP A BAND OF PRECIP OVER THE REGION SATURDAY MORNING...BUT WITH HIGH PRESSURE MOVING OVER THE REGION HAVE LOW CONFIDENCE AND WENT WITH A DRY FORECAST SATURDAY. SKIES WILL CLEAR BUT THE COOLER AIR OFF THE LAKE WILL RESULT IN HIGHS IN THE UPPER 40S TO MID 50S ALONG THE LAKE...AND THEN IN THE LOW TO MID 60S IN THE OUTLYING AREAS. GUIDANCE FEATURES PRECIP MOVING IN AHEAD OF THE NEXT LOW SATURDAY NIGHT. HAVE LOW CONFIDENCE IN THIS ROUND OF PRECIP AS WELL...BUT LEFT A CHANCE OF RAIN IN THE FORECAST. OVERNIGHT LOWS WILL RANGE FROM THE UPPER 30S TO THE MID 40S. EXTENDED...SUNDAY THROUGH TUESDAY... AN UPPER LEVEL CLOSED LOW SHIFTS OVER THE GREAT PLAINS SUNDAY EVENING/NIGHT. GUIDANCE DIFFERS ON ITS EXACT PATH EARLY NEXT WEEK BUT DOES HAVE THE UPPER LEVEL LOW OVER THE REGION THROUGH AT LEAST MID WEEK. ITS ASSOCIATED SURFACE LOW MOVES OVER THE PLAINS LATE SUNDAY NIGHT/MONDAY MORNING AND SLIDES SOUTH OF THE CWA MONDAY NIGHT. THE 12Z GUIDANCE AGREED A BIT MORE ABOUT THE SURFACE LOWS PATH...AND HAVE IT MOVING THROUGH SOUTHERN IL TUESDAY. IN TWO WORDS EARLY NEXT WEEK LOOKS CHILLY AND WET. A BOUNDARY OVER NORTHERN IL BRINGS THE LIFT FOR THE FIRST WAVE OF PRECIP EARLY ON SUNDAY...BUT THEN MULTIPLE VORTICITY STREAMERS PASS THROUGH THE REGION AS THE LOW SLOWLY SHIFTS EAST. THIS WILL RESULT IN A CHANCE OF PRECIP THROUGHOUT THE EXTENDED. WILL INCLUDE A SLIGHT CHANCE OF THUNDER ALONG AND SOUTH OF I-80 WHERE THERE WILL BE LIMITED ELEVATED INSTABILITY BUT ENOUGH TO PERHAPS SUPPORT A COUPLE OF THUNDERSTORMS SUNDAY NIGHT AND MONDAY. THE UPPER LEVEL JET DIPS FAR SOUTH THROUGH TEXAS ALLOWING COOL AIR TO SPREAD ACROSS THE REGION. AS SUCH HIGHS WILL VARY BETWEEN THE LOW 50S NORTH TO MID 60S SOUTH WITH A COOLING TREND THROUGH TUESDAY. LUCKILY OVERNIGHT LOWS LOOK LIKE THEY WILL REMAIN ABOVE FREEZING. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * VARIABILITY IN THE WINDS REST OF THIS AFTERNOON FROM NNE TO ESE. * CHANCE FOR SHOWERS THIS EVENING...THEN BETTER CHANCES FOR SHOWERS LATE THURSDAY AFTERNOON. * WINDS VEERING TO SSE BY TOMORROW...THEN BECOMING VERY GUSTY LATE TOMORROW MORNING INTO THE AFTERNOON. BMD/CMS //DISCUSSION...UPDATED 18Z... HIGH PRESSURE WILL CONTINUE TO SLOWLY SHIFT EAST AWAY FROM THE TERMINALS THIS AFTERNOON WITH WINDS CONTINUING TO VEER FROM THE NORTHEAST EARLY THIS AFTERNOON TO THE SOUTHEAST OVERNIGHT. SHOWERS CURRENTLY OVER SOUTHERN MINNESOTA AND IOWA MAY SKIRT THE IL/WI STATE LINE LATE THIS AFTERNOON THROUGH LATE EVENING BRINGING A SMALL CHANCE FOR SHOWERS. COVERAGE IS STILL UNCERTAIN SO WILL MAINTAIN PROB30 FOR THE CHICAGO TERMINALS AND VCSH FOR RFD. MEANWHILE...LOW PRESSURE WILL DEVELOP OVER THE SOUTHERN PLAINS AND LIFT TO THE MID MISSISSIPPI VALLEY BY MIDDAY THURSDAY. THE GRADIENT WILL TIGHTEN AHEAD OF THE LOW WITH GUSTS GRADUALLY INCREASING INTO THE UPPER 20 KT RANGE OT OF THE SSE...AND CANNOT RULE OUT SOME GUSTS IN EXCESS OF 30 KT. SHOWERS AND PERHAPS A FEW THUNDERSTORMS WILL THEN OVERSPREAD THE TERMINALS MID TO LATE THURSDAY AFTERNOON. BMD //ORD AND MDW CONFIDENCE...UPDATED 22Z... * MEDIUM CONFIDENCE IN WIND DIRECTION THIS AFTERNOON...MEDIUM-HIGH CONFIDENCE ON WIND DIRECTION/SPEED THURSDAY. * LOW CONFIDENCE IN PRECIP AT TERMINALS THIS EVENING...MEDIUM CONFIDENCE IN PRECIP TIMING THURSDAY AFTERNOON. BMD/CMS //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...SHRA/MVFR LIKELY WITH A CHANCE OF TSRA. FRIDAY...SLIGHT CHANCE OF SHOWERS LATE...OTHERWISE VFR. SATURDAY...SLIGHT CHANCE OF SHOWERS LATE...OTHERWISE VFR. SUNDAY...CHANCE OF SHOWERS...OTHERWISE VFR. MONDAY...CHANCE OF SHOWERS...OTHERWISE VFR. TUESDAY...CHANCE OF SHOWERS...OTHERWISE VFR. RODRIGUEZ && .MARINE... 219 PM CDT PROGRESSIVE FLOW WILL CONTINUE THROUGH FRIDAY BEFORE A MUCH MORE AMPLIFIED AND LOCKED PATTERN WILL SET UP FOR THE WEEKEND THROUGH THE MIDDLE OF NEXT WEEK. THE HIGH PRESSURE PRESENTLY OVER THE LAKE WILL BE SCOOTED EASTWARD EARLY FRIDAY AS LOW PRESSURE FROM THE CENTRAL PLAINS BOOKS EASTWARD INTO NORTHERN INDIANA. DURING THURSDAY THIS WILL PROVIDE STRONG SOUTHERLY FLOW. A FAIRLY STOUT INVERSION SHOULD BE PRESENT OVER THE LAKE...BUT STRONG OFFSHORE WINDS IN NEARSHORE AREAS SHOULD LEAD TO 25 TO POSSIBLE 30 KT GUSTS. AS A DEEP TROUGH SETS UP ACROSS THE WESTERN U.S. AND SLOWLY MOVES EAST THROUGH THE WEEKEND AND EARLY NEXT WEEK...SURFACE HIGH PRESSURE WILL GET LOCKED OVER THE CENTRAL GREAT LAKES. A TIGHTENING PRESSURE GRADIENT ON ITS SOUTHERN AND WESTERN SIDES WILL PROVIDE CONTINUOUS EAST TO NORTHEAST SURFACE WINDS. THIS LOOKS LIKE A POTENTIAL PROLONGED PERIOD OF SMALL CRAFT ADVISORY CRITERIA. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...10 AM THURSDAY TO 10 PM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
310 PM CDT WED APR 23 2014 .DISCUSSION... 310 PM CDT SYNOPSIS...ANOTHER PLEASANT DAY TODAY...BUT SHOWERS MOVE IN FROM THE WEST THIS EVENING. SHOWERS AND STORMS ARE EXPECTED TOMORROW AFTERNOON AND EVENING WITH A DRY AND WARM END TO THE WORK WEEK. THIS WEEKEND LOOKS TO HAVE BELOW NORMAL TEMPERATURES WITH SHOWERS AND PERHAPS SOME THUNDERSTORMS ALONG AND SOUTH OF I-80 FOR THE FIRST HALF OF NEXT WEEK. REST OF TODAY AND TONIGHT... A LARGE UPPER LEVEL RIDGE IS OVER THE CENTRAL PLAINS WHILE A SURFACE HIGH IS CENTERED OVER LAKE MICHIGAN. THE RIDGE PASSES OVERHEAD TONIGHT WHILE THE SURFACE HIGH PUSHES EAST TO THE NORTHERN OHIO VALLEY THROUGH EASTERN QUEBEC. A WEAK SHORTWAVE IS OVER EASTERN NEBRASKA AND WESTERN IOWA WITH SHOWERS OVER WESTERN IOWA. THE SHOWERS WILL CONTINUE TO PUSH EAST...BUT WITH DEWPOINT DEPRESSIONS AT 20+ DEGREES...THINKING THE SHOWERS WILL DISSIPATE A BIT BEFORE MOVING INTO CENTRAL IL. AS SUCH THINKING THE FIRST SHOWERS WILL ENTER THE FAR EASTERN CWA AFTER 5PM CST. USED THE LOCAL ARW...RAP...AND HRRR TO CREATE THE POPS FOR THE REST OF TODAY AND TONIGHT. THINKING A BAND OF SCATTERED SHOWERS WILL SLOWLY CROSS NORTHERN IL THIS EVENING IN ASSOCIATION WITH AN UPPER LEVEL VORTICITY STREAMER. THE BEST COVERAGE WILL BE BETWEEN MIDNIGHT AND 4 AM CST WITH A CHANCE OF LIGHT RAIN SHOWERS NORTH OF I-80. THE BAND THEN LIFTS NORTH EARLY THURSDAY MORNING AS THE RIDGE MOVES DIRECTLY OVERHEAD. NOT EXPECTING ANY SIGNIFICANT PRECIP ACCUMULATIONS. CLOUD COVER WILL INCREASE THROUGH THIS AFTERNOON AND LOOKING AT MIN TEMPS IN THE UPPER 30S TO MID 40S ACROSS THE CWA. TOMORROW AND TOMORROW NIGHT... AN UPPER LEVEL TROUGH MOVES OVER THE PLAINS TOMORROW MORNING AND THE TROUGH PASSES OVER THE REGION TOMORROW NIGHT. THE UPPER LEVEL LOW ASSOCIATED WITH THE TROUGH PASSES FARTHER NORTH...ALONG THE US/CANADA BORDER. THE SURFACE LOW ALSO BEGINS OVER THE PLAINS THURSDAY MORNING AND THEN MOVES OVER IL THURSDAY EVENING. GUIDANCE HAS THE LOW PROGRESSING A BIT SLOWER AND MADE THE NECESSARY ADJUSTMENTS. RAIN AND SOME STORMS MOVE IN FROM THE WEST THROUGH THE MORNING AND EARLY AFTERNOON. INSTABILITY IS NOT EXTREMELY IMPRESSIVE WITH THE SYSTEM SO KEPT ONLY A CHANCE OF THUNDER. QPF AMOUNTS ON THE OTHER HAND COULD BE IMPRESSIVE WITH TOTALS AROUND A HALF INCH OF RAIN. WINDS WILL ALSO BE SHIFTING FROM SOUTHEAST IN THE MORNING TO OUT OF THE WEST OVERNIGHT BEHIND THE LOW. LOOKING AT A BREEZY AFTERNOON WITH SOUTH WINDS GUSTING TO 35 MPH. THE AMPLE WAA WILL LEAD TO MAX TEMPS FROM AROUND 60 ALONG THE IL/WI BORDER TO THE UPPER 60S IF NOT 70 IN THE SOUTHERN CWA. FRIDAY AND SATURDAY... THE UPPER LEVEL LOW CONTINUES TO SHIFT EAST REACHING NEW ENGLAND BY SATURDAY AFTERNOON/EVENING. THE SURFACE LOW SHIFTS EAST AND EXPECTING PRECIP TO COME TO AN END EARLY FRIDAY MORNING. WEST WINDS WILL BE GUSTING TO ARND 30 MPH FRIDAY AND AM THINKING THERE COULD BE SOME DRY AIR MIXING DOWN TO THE SURFACE SO LOWERED DEWPOINTS A BIT. THE AIR BEHIND THE COLD FRONT IS NOT REALLY ALL THAT COLD SINCE MAX TEMPS ON FRIDAY LOOK TO BE AROUND 70 DEGREES. A BACK DOOR COLD FRONT SLIDES DOWN FROM THE NORTH IN THE EVENING. SOME GUIDANCE MEMBERS FEATURE A BAND OF PRECIP FORMING AHEAD OF THE FRONT OVER FAR NORTHERN IL AND NW INDIANA. PUT IN A CHANCE OF PRECIP SINCE FORCING LOOKS GOOD...BUT HAVE LOW CONFIDENCE IN THE BAND OF PRECIP ACTUALLY FORMING. AS SUCH KEPT POPS IN THE CHANCE RANGE. WINDS TURN NORTHEAST BEHIND THE FRONT AND OVERNIGHT LOWS WILL BE IN THE UPPER 30S TO MID 40S. SOME GUIDANCE MEMBERS KEEP A BAND OF PRECIP OVER THE REGION SATURDAY MORNING...BUT WITH HIGH PRESSURE MOVING OVER THE REGION HAVE LOW CONFIDENCE AND WENT WITH A DRY FORECAST SATURDAY. SKIES WILL CLEAR BUT THE COOLER AIR OFF THE LAKE WILL RESULT IN HIGHS IN THE UPPER 40S TO MID 50S ALONG THE LAKE...AND THEN IN THE LOW TO MID 60S IN THE OUTLYING AREAS. GUIDANCE FEATURES PRECIP MOVING IN AHEAD OF THE NEXT LOW SATURDAY NIGHT. HAVE LOW CONFIDENCE IN THIS ROUND OF PRECIP AS WELL...BUT LEFT A CHANCE OF RAIN IN THE FORECAST. OVERNIGHT LOWS WILL RANGE FROM THE UPPER 30S TO THE MID 40S. EXTENDED...SUNDAY THROUGH TUESDAY... AN UPPER LEVEL CLOSED LOW SHIFTS OVER THE GREAT PLAINS SUNDAY EVENING/NIGHT. GUIDANCE DIFFERS ON ITS EXACT PATH EARLY NEXT WEEK BUT DOES HAVE THE UPPER LEVEL LOW OVER THE REGION THROUGH AT LEAST MID WEEK. ITS ASSOCIATED SURFACE LOW MOVES OVER THE PLAINS LATE SUNDAY NIGHT/MONDAY MORNING AND SLIDES SOUTH OF THE CWA MONDAY NIGHT. THE 12Z GUIDANCE AGREED A BIT MORE ABOUT THE SURFACE LOWS PATH...AND HAVE IT MOVING THROUGH SOUTHERN IL TUESDAY. IN TWO WORDS EARLY NEXT WEEK LOOKS CHILLY AND WET. A BOUNDARY OVER NORTHERN IL BRINGS THE LIFT FOR THE FIRST WAVE OF PRECIP EARLY ON SUNDAY...BUT THEN MULTIPLE VORTICITY STREAMERS PASS THROUGH THE REGION AS THE LOW SLOWLY SHIFTS EAST. THIS WILL RESULT IN A CHANCE OF PRECIP THROUGHOUT THE EXTENDED. WILL INCLUDE A SLIGHT CHANCE OF THUNDER ALONG AND SOUTH OF I-80 WHERE THERE WILL BE LIMITED ELEVATED INSTABILITY BUT ENOUGH TO PERHAPS SUPPORT A COUPLE OF THUNDERSTORMS SUNDAY NIGHT AND MONDAY. THE UPPER LEVEL JET DIPS FAR SOUTH THROUGH TEXAS ALLOWING COOL AIR TO SPREAD ACROSS THE REGION. AS SUCH HIGHS WILL VARY BETWEEN THE LOW 50S NORTH TO MID 60S SOUTH WITH A COOLING TREND THROUGH TUESDAY. LUCKILY OVERNIGHT LOWS LOOK LIKE THEY WILL REMAIN ABOVE FREEZING. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * VARIABILITY IN THE WINDS REST OF THIS AFTERNOON FROM NNE TO ESE. * CHANCE FOR SHOWERS THIS EVENING...THEN BETTER CHANCES FOR SHOWERS LATE THURSDAY AFTERNOON. * WINDS VEERING TO SSE BY TOMORROW...THEN BECOMING VERY GUSTY LATE TOMORROW MORNING INTO THE AFTERNOON. BMD //DISCUSSION...UPDATED 18Z... HIGH PRESSURE WILL CONTINUE TO SLOWLY SHIFT EAST AWAY FROM THE TERMINALS THIS AFTERNOON WITH WINDS CONTINUING TO VEER FROM THE NORTHEAST EARLY THIS AFTERNOON TO THE SOUTHEAST OVERNIGHT. SHOWERS CURRENTLY OVER SOUTHERN MINNESOTA AND IOWA MAY SKIRT THE IL/WI STATE LINE LATE THIS AFTERNOON THROUGH LATE EVENING BRINGING A SMALL CHANCE FOR SHOWERS. COVERAGE IS STILL UNCERTAIN SO WILL MAINTAIN PROB30 FOR THE CHICAGO TERMINALS AND VCSH FOR RFD. MEANWHILE...LOW PRESSURE WILL DEVELOP OVER THE SOUTHERN PLAINS AND LIFT TO THE MID MISSISSIPPI VALLEY BY MIDDAY THURSDAY. THE GRADIENT WILL TIGHTEN AHEAD OF THE LOW WITH GUSTS GRADUALLY INCREASING INTO THE UPPER 20 KT RANGE OT OF THE SSE...AND CANNOT RULE OUT SOME GUSTS IN EXCESS OF 30 KT. SHOWERS AND PERHAPS A FEW THUNDERSTORMS WILL THEN OVERSPREAD THE TERMINALS MID TO LATE THURSDAY AFTERNOON. BMD //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN WIND DIRECTION THIS AFTERNOON...MEDIUM-HIGH CONFIDENCE ON WIND DIRECTION/SPEED THURSDAY. * LOW CONFIDENCE IN PRECIP AT TERMINALS THIS EVENING...MEDIUM CONFIDENCE IN PRECIP TIMING THURSDAY AFTERNOON. BMD //OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z... THURSDAY NIGHT...SHRA/MVFR LIKELY WITH A CHANCE OF TSRA. FRIDAY...SLIGHT CHANCE OF SHOWERS LATE...OTHERWISE VFR. SATURDAY...SLIGHT CHANCE OF SHOWERS LATE...OTHERWISE VFR. SUNDAY...CHANCE OF SHOWERS...OTHERWISE VFR. MONDAY...CHANCE OF SHOWERS...OTHERWISE VFR. TUESDAY...CHANCE OF SHOWERS...OTHERWISE VFR. RODRIGUEZ && .MARINE... 219 PM CDT PROGRESSIVE FLOW WILL CONTINUE THROUGH FRIDAY BEFORE A MUCH MORE AMPLIFIED AND LOCKED PATTERN WILL SET UP FOR THE WEEKEND THROUGH THE MIDDLE OF NEXT WEEK. THE HIGH PRESSURE PRESENTLY OVER THE LAKE WILL BE SCOOTED EASTWARD EARLY FRIDAY AS LOW PRESSURE FROM THE CENTRAL PLAINS BOOKS EASTWARD INTO NORTHERN INDIANA. DURING THURSDAY THIS WILL PROVIDE STRONG SOUTHERLY FLOW. A FAIRLY STOUT INVERSION SHOULD BE PRESENT OVER THE LAKE...BUT STRONG OFFSHORE WINDS IN NEARSHORE AREAS SHOULD LEAD TO 25 TO POSSIBLE 30 KT GUSTS. AS A DEEP TROUGH SETS UP ACROSS THE WESTERN U.S. AND SLOWLY MOVES EAST THROUGH THE WEEKEND AND EARLY NEXT WEEK...SURFACE HIGH PRESSURE WILL GET LOCKED OVER THE CENTRAL GREAT LAKES. A TIGHTENING PRESSURE GRADIENT ON ITS SOUTHERN AND WESTERN SIDES WILL PROVIDE CONTINUOUS EAST TO NORTHEAST SURFACE WINDS. THIS LOOKS LIKE A POTENTIAL PROLONGED PERIOD OF SMALL CRAFT ADVISORY CRITERIA. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...10 AM THURSDAY TO 10 PM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
255 PM CDT Wed Apr 23 2014 ...UPDATE TO LONG TERM... .SHORT TERM...(This evening through Thursday) ISSUED AT 142 PM CDT WED APR 23 2014 RAP, HRRR, and NAM all suggesting dryline will be located near Garden City and Liberal between 21Z Wednesday and 00z Thursday. Convective initiation along this boundary however somewhat more uncertain given the warm 700mb temperatures and cloud cover/precipitation currently over portions of southwest Kansas. At this time based on the ARW,NMM, and HRRR still suggests there will be some widely scattered convection developing late day/early this evening. Will therefore follow the general trend of the non hydrostatic models for for late today/early tonight but keep precipitation chances more widely scattered. Mid level instability and shear continues to support that if storms do develop they will be capable of becoming severe. Main hazard early tonight still appears to be hail and strong winds given shear, mid level instability, high cloud bases, downdraft capes, and model soundings at 00z Thursday. A cold front crossing northwest Kansas earlier this afternoon is forecast to cross southwest Kansas between 00z and 09z Thursday. Convection along this cold front is expected to develop late day and increase in areal coverage early tonight as an upper level trough, which was located near the four corners region as 12z Thursday, moves east across the Central High Plains. This cold front will provide the better opportunity for precipitation, especially along and east of a Dighton to Liberal line based on where the better low level moisture is forecast to be early tonight by the NAM. Precipitation chances will begin to taper off from northwest to southeast, mainly after midnight as this cold front surges south. Behind this cold front very windy conditions are expected to develop given the pressure tendencies and 925 to 850mb winds. Wind speeds of 30 to 35 mph will be likely for several hours behind this front, especially west of highway 283 between 03z and 09z. After 09z Thursday the winds will begin to decrease and are expected to continue to decrease during the day on Thursday as a surface high/ridge axis crosses western Kansas. NAM and GFS 850mb mixdown temperatures and guidance was with 2-4 degrees of each other for highs on Thursday so given this and the expected sunshine Thursday afternoon will stay close to what they suggest. .LONG TERM...(Thursday night through Wednesday) ISSUED AT 255 PM CDT WED APR 23 2014 Medium range models indicate weak upper level ridging transitioning eastward across the Western High Plains Friday and into the Central Plains Saturday. Meanwhile, a strong upper level trough of low pressure will begin to push ashore into southern California Saturday setting up a southwest flow across the Western High Plains by Saturday afternoon. As a lack of significant low/mid level moisture prevails during this time frame, dry conditions will persist through Saturday afternoon. The potential for thunderstorms returns Saturday evening as the upper level trough begins to lift northeast out of the Desert Southwest into the Western High Plains. As the shortwave approaches, a prevailing low level southeasterly flow will continue to draw moisture northward into Kansas ahead of a sharpening dryline. Although where the dryline sets up is uncertain this far out, the likelihood for thunderstorm development is good ahead of it as upper level dynamic support becomes more favorable. Severe weather is possible late Saturday into early Sunday morning. Precip potential shifts north and east Sunday as the upper level trough lifts northeast across the Western High Plains increasing the potential for dryslotting across southwest Kansas. Temperatures will be above normal Friday as weak upper level ridging moves eastward out of the Rockies across the Western High Plains. A south to southeasterly flow will return to western Kansas as lee side troughing redevelops across eastern Colorado. This will draw warmer air north into the area with H85 temperatures ranging from around 20C across central Kansas to near 25C in far southwest Kansas. Look for highs well up into the 80s(F) Friday afternoon. The warming trend continues into Saturday as enhanced warm air advection raises H85 temperatures into the mid to upper 20s(C) across southwest Kansas. Mid to upper 80s(F) are likely Saturday afternoon with the lower 90s(F) possible behind a dryline across extreme southwest Kansas. Much cooler temperatures will arrive early next week as a cold front sweeps through western Kansas. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) ISSUED AT 1204 PM CDT WED APR 23 2014 Scattered thunderstorms will be possible by late day near a dryline which will be located GCK to near LBL. Given the scattered nature of these storms will favor VCTS over a tempo or prevailing group between 21z and 03z. A better chance for convection will accompany a cold front as it crosses southwest Kansas between 03z Thursday and 09z Thursday. Cloud bases late today and overnight are expected to be at or above the 800mb level so VFR conditions are expected. Ahead of the approaching cold front, gusty south at near 25 knots will continue through early tonight across all of western Kansas. As the cold front passes these gusty winds will shift to the north and increase once again to near 25 knots for several hours before decreasing into the 15 to 20 knot range. && .PRELIMINARY POINT TEMPS/POPS... DDC 46 72 45 84 / 60 0 0 0 GCK 44 71 44 84 / 40 10 0 0 EHA 44 73 45 85 / 10 0 0 0 LBL 45 75 45 86 / 20 0 0 0 HYS 46 72 43 81 / 80 10 0 0 P28 53 75 46 85 / 60 10 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY until 8 PM CDT this evening FOR KSZ030-031-045-046- 064>066-077>081-087>090. WIND ADVISORY from 8 PM CDT /7 PM MDT/ this evening to 2 AM CDT /1 AM MDT/ Thursday FOR KSZ061-062-074-075-084-085. WIND ADVISORY until 2 AM CDT Thursday FOR KSZ043-044-063-076-086. RED FLAG WARNING until 8 PM CDT this evening FOR KSZ074-075-084- 085. && $$ SHORT TERM...Burgert LONG TERM...JJohnson AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
144 PM CDT Wed Apr 23 2014 ...Updated short term discussion... .SHORT TERM...(This evening through Thursday) ISSUED AT 142 PM CDT WED APR 23 2014 RAP, HRRR, and NAM all suggesting dryline will be located near Garden City and Liberal between 21Z Wednesday and 00z Thursday. Convective initiation along this boundary however somewhat more uncertain given the warm 700mb temperatures and cloud cover/precipitation currently over portions of southwest Kansas. At this time based on the ARW,NMM, and HRRR still suggests there will be some widely scattered convection developing late day/early this evening. Will therefore follow the general trend of the non hydrostatic models for for late today/early tonight but keep precipitation chances more widely scattered. Mid level instability and shear continues to support that if storms do develop they will be capable of becoming severe. Main hazard early tonight still appears to be hail and strong winds given shear, mid level instability, high cloud bases, downdraft capes, and model soundings at 00z Thursday. A cold front crossing northwest Kansas earlier this afternoon is forecast to cross southwest Kansas between 00z and 09z Thursday. Convection along this cold front is expected to develop late day and increase in areal coverage early tonight as an upper level trough, which was located near the four corners region as 12z Thursday, moves east across the Central High Plains. This cold front will provide the better opportunity for precipitation, especially along and east of a Dighton to Liberal line based on where the better low level moisture is forecast to be early tonight by the NAM. Precipitation chances will begin to taper off from northwest to southeast, mainly after midnight as this cold front surges south. Behind this cold front very windy conditions are expected to develop given the pressure tendencies and 925 to 850mb winds. Wind speeds of 30 to 35 mph will be likely for several hours behind this front, especially west of highway 283 between 03z and 09z. After 09z Thursday the winds will begin to decrease and are expected to continue to decrease during the day on Thursday as a surface high/ridge axis crosses western Kansas. NAM and GFS 850mb mixdown temperatures and guidance was with 2-4 degrees of each other for highs on Thursday so given this and the expected sunshine Thursday afternoon will stay close to what they suggest. .LONG TERM...(Thursday through Tuesday) ISSUED AT 343 AM CDT WED APR 23 2014 A surface high will be moving through the area into Texas on Thursday morning, resulting in light surface winds at least by the afternoon after wind slacken through the morning. Aside form any cirrus that might be associated with the upper jet skies should be sunny given the low relative humidity in the lower and middle troposphere. A better surface pressure gradient will be in place by Friday resulting in breezy southerly winds. Another dynamic synoptic scale storm system will affect the region for the weekend. Both the GFS and ECMWF are in good agreement of the evolution of another well pronounced dryline for Saturday, with convection likely followed by a rapidly deepening low pressure over western Kansas for Sunday. The low pressure is modeled to track northeastward into the Missouri valley. The expected track implies our area could see both a warm sector/convective threat Saturday and deformation zone precipitation as well into Saturday evening or early Sunday. While precipitation timing modes/amount may be the most uncertain characteristics, the warm boundary layer ensures pcpn will be rain while high confidence also exists in windy conditions Sunday and Sunday night. Potential exists for high winds on the backside of the exiting low, centered around Monday morning most likely. Gridded model output statistics indicates sustained winds around 40 knots. Winds were adjusted away from the initial ALLblend forecast, to a much closer consensus of MOS for Saturday through Monday. Models suggest deep meridional flow across western Kansas and a few windy days into the early part of next week. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) ISSUED AT 1204 PM CDT WED APR 23 2014 Scattered thunderstorms will be possible by late day near a dryline which will be located GCK to near LBL. Given the scattered nature of these storms will favor VCTS over a tempo or prevailing group between 21z and 03z. A better chance for convection will accompany a cold front as it crosses southwest Kansas between 03z Thursday and 09z Thursday. Cloud bases late today and overnight are expected to be at or above the 800mb level so VFR conditions are expected. Ahead of the approaching cold front, gusty south at near 25 knots will continue through early tonight across all of western Kansas. As the cold front passes these gusty winds will shift to the north and increase once again to near 25 knots for several hours before decreasing into the 15 to 20 knot range. && .PRELIMINARY POINT TEMPS/POPS... DDC 46 72 45 82 / 60 0 0 0 GCK 44 73 44 82 / 50 10 0 0 EHA 44 71 45 83 / 10 0 0 0 LBL 45 74 45 84 / 30 0 0 0 HYS 46 73 43 79 / 80 10 0 0 P28 53 72 46 83 / 60 10 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY until 8 PM CDT this evening FOR KSZ030-031-043>046- 063>066-076>081-086>090. RED FLAG WARNING until 8 PM CDT this evening FOR KSZ074-075-084- 085. && $$ SHORT TERM...Burgert LONG TERM...Russell AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1232 PM CDT Wed Apr 23 2014 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 341 AM CDT WED APR 23 2014 08Z water vapor shows a longwave trough moving into the Rockies with a mid level ridge axis over the Great Plains. At the surface, obs shows ridging along the upper and middle MS river valley with a lee trough over WY and CO deepening. Radar shows scattered shower activity gradually expanding in coverage over the past couple hours. The RAP and NAM show isentropic upglide on the 305K surface, which seems to line up with where the elevated showers are developing, persisting into the early afternoon. With the HRRR, RAP and NAM all showing this scattered activity going on through the morning, have increased pops and will include coverage wording in the forecast. Forecast soundings show little if any instability for this activity to work with so would anticipate thunder to remain relatively isolated this morning. Meanwhile the models continue to show some surface based instability developing this afternoon across north central KS ahead of a Pacific cold front. As the upper shortwave moves out across the plains, thunderstorms are expected to develop along this boundary. This activity is expected to quickly evolve into a linear system and move across the forecast area overnight. Initially there may be some hail and damaging wind threat as the line begins moving into north central KS. And there remains a large amount of low level bulk shear progged by the NAM. But the NAM also develops quite a lot of CIN suggesting the line of storms may be driven more by the front and not necessarily persisting on instability ahead of the boundary. So the expectation is that storm intensity will diminish as the storms move into eastern KS. In any case, good forcing from the shortwave and steep mid level lapse rates should be good enough for much of not all of the forecast to see rain overnight and will maintain categorical POPs tonight. Do not plan to change the wind advisory issued earlier. The latest RAP continues to show a strengthening pressure gradient over south central NEB and north central KS that may be strong enough for sustained winds of 30 mph for a brief period. Otherwise the NAM and GFS are more marginal with the pressure gradient and do not produce as strong of winds. For highs today, am a little concerned the scattered precip and cloud cover could hold temps down especially over northeast KS where this is likely to hang on longer into the afternoon. So tweaked temps down a degree or two over northeast zones. Although there may still be enough mixing and insolation across north central KS for highs to reach around 80. With rain and some cold air advection behind the front tonight, trended min temps Thursday morning down towards the MOS consensus of lower 50s in north central KS to the mid and upper 50s across eastern KS. If the front moves through a little quicker, lows in the east are likely to be to warm. .LONG TERM...(Thursday through Tuesday) Issued at 341 AM CDT WED APR 23 2014 Cold front will continue to move southeastward and out of the far southeast corner by mid morning on Thursday as the upper trough axis swings through CWA. Will therefore continue a steady decline in precipitation chances over the eastern CWA through the morning hours and a dry afternoon forecast. Although the day may start out wet and cloudy early...decreasing clouds and backing low level winds will aid in temperatures rising back into the low to mid 70s for highs. Winds back around to light southwesterly overnight with lows in the 40s before increasing through the day Friday with mostly sunny skies. Have therefore edged high temperatures upwards slightly to around 80 in many areas. Elevated moisture return and weak instability slowly increase late Friday night/early Saturday morning across the southern CWA and have maintained low chances for thunderstorms. A better chance for thunderstorms will exist with the deeper moisture and instability later in the day into early Sunday as the next strong shortwave trough digs into the desert southwest and ejects out into the central high plains. Thunderstorms may remain elevated until an initial capping inversion is overcome for surface based storms to develop. Either way...strong to severe thunderstorms will be possible Saturday into Sunday ahead of an expected dry slot as the system rotates out into the plains and occludes. It will then slow and shift east and southeastward into the MS river valley with a lingering chance for showers in its wake as much cooler air filters into the area from the north for Monday and especially Tuesday. Highs in the 70s on Saturday will lower into the low to mid 60s for Monday...then the 50s for Tuesday. Lows by Wednesday morning could fall into the mid to upper 30s. && .AVIATION...(For the 18Z TAFs through 18Z Thursday Afternoon) Issued at 1223 PM CDT WED APR 23 2014 The scattered showers and isolated thunder has remained north of the taf sites although kept VCSH for the showers moving eastward from central KS. VFR should prevail through most of the afternoon and early evening hours. Storms will develop into a line over north central KS and move eastward this evening. There is some uncertainty with the timing of the thunderstorms as to when to affect the taf sites. This timing will likely need adjustments later today. Storms could cause brief IFR conditions with heavier rainfall. Additional rain showers will develop along and behind a cold front passing through the area. Widespread showers should exit tomorrow morning with improving ceilings towards the end of the period. && .TOP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY until 6 PM CDT this evening FOR KSZ008-009-020-021- 034-035. && $$ SHORT TERM...Wolters LONG TERM...63 AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
508 PM EDT WED APR 23 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 507 PM EDT WED APR 23 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF SWEEPING ACROSS THE WRN CONUS WITH AXIS OVER THE ROCKIES THEN CURVING NW AND OFF THE COAST OF BRITISH COLUMBIA. DOWNSTREAM RIDGE EXTENDS ACROSS THE MISSISSIPPI VALLEY AND IS SUPPORTING SFC HIGH PRES RIDGE EXTENDING FROM NRN ONTARIO ACROSS THE WRN GREAT LAKES AND DOWN TO THE GULF COAST. VERY DRY AIR MASS IS ASSOCIATED WITH THE RIDGE PER REGIONAL 12Z RAOBS. END RESULT HAS BEEN PLENTY OF SUNSHINE TO START THE DAY...BUT HIGH CLOUDS ARE FANNING E INTO THE AREA AHEAD OF THE WRN CONUS TROF. DRY AIR HAS ALLOWED DEEP MIXING IN THE INTERIOR WHERE TEMPS HAVE RISEN SIGNIFICANTLY FROM THE EARLY MORNING CHILL. TEMPS ARE INTO THE LOW AND MID 50S AWAY FROM MARINE COOLING. ALONG LAKE SUPERIOR...TEMPS ARE IN THE MID 30S TO LWR 40S. DEEP MIXING INTO THE DRY AIR ALOFT HAS ALSO CAUSED SFC DWPTS TO FALL AS LOW AS THE MID TEENS AT SOME LOCATIONS. SHORT TERM WILL BEGIN QUIET WITH VERY DRY AIR MASS LINGERING OVER THE AREA IN ASSOCIATION WITH SFC HIGH PRES RIDGE DRIFTING E FROM THE WRN GREAT LAKES. HIGH AND THEN MID CLOUDS WILL CONTINUE TO ADVANCE INTO THE UPPER LAKES TONIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS E AHEAD OF THE TROF MOVING INTO THE WRN PLAINS. WITH WAA/ISENTROPIC NOT PARTICULARLY STRONG TONIGHT AND WITH SUBSTANTIAL ANTECEDANT LOW-LEVEL DRY AIR IN PLACE (NOTE THE VERY DRY AIR SAMPLED ON REGIONAL 12Z RAOBS)...IT MAY BE TOUGH TO GET PCPN INTO WRN UPPER MI LATE TONIGHT. WILL NEED TO WATCH THE INITIAL NNW-SSE ORIENTED PCPN BAND CURRENTLY OVER MN TO SEE HOW AGGRESSIVELY IT BATTLES THE DRY AIR THIS EVENING. FOR NOW...WILL UTILIZE MOSTLY SCHC POPS OVER FAR WRN UPPER MI OVERNIGHT WITH CHC NEAR KIWD. PTYPE WILL PROBABLY BE RAIN...BUT WITH DRY AIR/EVAPORATIVE COOLING AND LIMITED DEPTH OF ABOVE 0C WETBULB TEMPS...THERE COULD BE SOME WET SNOW. AT 12Z THU...MID/UPPER LEVEL TROF AXIS WILL BE OVER THE WRN PLAINS. WITHIN THE TROF...STRONGER SHORTWAVE WILL BE OVER ERN MT/WRN ND WITH SRN SHORTWAVE OVER THE SRN PLAINS. THRU THE DAY...THE NRN WAVE WILL DEEPEN AS IT TRACKS A LITTLE S OF E WHILE THE SRN PLAINS WAVE TRACKS SLIGHTLY N OF E. AS THE TROF SHARPENS UP/DEEPENS WHILE SHIFTING E...RIBBON OF STRONGER ISENTROPIC ASCENT TRANSLATES TO THE UPPER LAKES ALONG WITH INCREASING DEEP LAYER FORCING. WITH SUBSTANTIAL MOISTURE AVBL (MIXING RATIOS 4-5G/KG ADVECTING INTO UPPER MI AROUND 750MB)...DECENT PCPN AMOUNTS ARE LIKELY. FOR MANY DAYS...MODELS HAVE SHOWN THERMAL PROFILES ON THE BORDER FOR RAIN/SNOW...AND THAT HASN`T CHANGED MUCH. GIVEN THE HIGH SUN ANGLE THIS TIME OF YEAR...BOUNDARY LAYER WARMTH IS A PROBLEM...BUT IT APPEARS PCPN RATES WILL PROBABLY BE SUFFICIENT FOR PCPN TO CHANGE TO MOSTLY SNOW OVER HIGHER TERRAIN FROM DICKINSON/MARQUETTE COUNTIES WESTWARD. IN ADDITION...NEAR SFC E TO SE WINDS WILL CONTINUE TO ADVECT LOW-LEVEL DRIER AIR INTO THE FCST AREA...AIDING EVAPORATIVE COOLING. THUS...GRIDS WILL SHOW AN EXPANSION OF SNOW PTYPE AS HEAVIER PCPN SPREADS NE THU AFTN ALONG WITH SFC TEMPS FALLING TO AROUND 33/34F. DETERMINING SNOW ACCUMULATIONS THIS LATE IN THE SEASON WITH HIGHER SUN ANGLE IS A CHALLENGE. SNOW MAY NOT ACCUMULATE MUCH IF AT ALL ON ROADWAYS UNLESS HEAVY SNOW IS FALLING. ON GROUND SURFACES...SNOW ACCUMULATIONS OF AN INCH OR TWO MAY OCCUR WITH AS MUCH AS 3 POSSIBLE FROM WRN DICKINSON INTO GOGEBIC COUNTIES WHERE HEAVIEST PCPN ARRIVES IN THE AFTN. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 503 PM EDT WED APR 23 2014 WET SNOW POSSIBLE FOR PORTIONS OF NORTHWEST UPR MICHIGAN LATE THURSDAY INTO THURSDAY NIGHT. SNOW AMOUNTS ARE THE MAIN ISSUE WITH THE SYSTEM...AS THAT DICTATES THE NEED FOR ANY HEADLINES. SHORTWAVE TROUGH CROSSING THE ROCKIES THIS AFTN IS THE MAIN FOCUS FOR THE THURSDAY INTO FRIDAY TIME FRAME. TROUGH IS FORECAST ARRIVE OVER THE NORTHERN PLAINS TO THE MIDDLE MISSISSIPPI VALLEY THURSDAY EVENING. AT THE SFC...ONE LOW IS OVER NORTH DAKOTA WITH ANOTHER LOW CROSSING SOUTHERN PORTIONS OF THE UPPER GREAT LAKES. SFC TROUGH IS IN BTWN THE TWO LOWS. MODELS DIFFER ON WHICH SFC LOW IS STRONGER. TREND WAS EMERGING IN RECENT RUNS OF THE GFS/ECMWF/GEM-NH AND UKMET THAT NORTHERN PORTION OF THE SHORTWAVE TROUGH AT H85/H7/H5 WOULD BE THE STRONGER SECTION AND THAT TROUGH WOULD REMAIN MORE PROGRESSIVE WHICH RESULTED IN LESS PRECIP LATER THURSDAY NIGHT AND CERTAINLY INTO FRIDAY. RECENT NAM RUNS HAVE BEEN SHOWING MORE OF CLOSED OFF IDEA WITH MID LEVEL TROUGH AND IS MORE WRAPPED UP WITH THE UPPER LOW ON FRIDAY... SHOWING CLOSED OFF H5 LOW OVER SCNTRL LK SUPERIOR AT 18Z ON FRIDAY WITH CLOSED OFF H7/H85 AND SFC LOWS OVER CNTRL CWA AT THE SAME TIME...RESULTING IN DEFORMATION AXIS OF PRECIP LINGERING OVER NW CWA LATER THURSDAY NIGHT INTO FRIDAY. 12Z NAM CONTINUES TO SHOW THE SAME THING...BUT IS NOW JOINED BY GFS AND GEM-NH... REPRESENTING A SHIFT BACK TO WHAT THE GFS WAS SHOWING WITH THE 12Z RUN ON TUESDAY. SWITCH SHOWS UP IN GFS RUN TOTAL QPF WITH AREAS OF WESTERN CWA NOW SEEING WELL OVER AN INCH WHERAS PAST RUNS WERE MORE IN THE 0.50-1.00 RANGE. OVERALL THE THEME OFFERED UP BY THE 12Z MODELS IS THAT THE POTENTIAL FOR MORE SNOW FOR A LONGER DURATION IS INCREASING...ESPECIALLY OVER THE WESTERN THIRD OF THE CWA...INCLUDING THE KEWEENAW PENINSULA. DIVING INTO THE SPECIFICS...INITIAL SURGE OF PRECIP LATE THURSDAY AND THURSDAY EVENING IS SUPPORTED IN UPPER LEVELS BY H85-H5 Q-VECTOR CONVERGENCE AND H3-H25 DIVERGENCE ALOFT DUE TO DIFFLUENT FLOW AS JET STREAK LIFTS ACROSS UPPER GREAT LAKES FM MID MISSISSIPPI VALLEY TO NORTHERN ONTARIO. ADDITIONAL LOW-MID LEVEL FORCING IS DUE MAINLY TO H925-H85 THETA-E ADVECTION AHEAD OF SFC-H85 TROUGH ALONG WITH 290-295K ISENTROPIC ASCENT LIFTING ACROSS UPR MICHIGAN. MOISTURE INFLUX INTO SYSTEM MORE THAN SUFFICIENT FOR HEAVIER PRECIP WITH MIXING RATIOS OF 4-6G/KG ON THE 290K SFC /H8-H75/ AND AT LEAST 4G/KG ON THE 300K SFC /NEAR H7/. AS THE UPPER LOW BECOMES MORE NEGATIVELY TILTED LATER THURSDAY NIGHT...MAIN FORCING FOR PRECIP WILL COME VIA PERSISTENT ISENTROPIC ASCENT AND DEFORMATION ALONG AND NORTHWEST OF MAINLY THE H85 LOW. NAM WOULD SUGGEST TROWAL PRECIP ENHANCEMENT COULD IMPACT KEWEENAW BASED ON THE THETA-E AT THE H65-H6 LAYER. FOR THE FORECAST...WILL TREND TOWARD NEGATIVE TILTED SYSTEM...BUT KEEP HEAVIER QPF ANCHORED IN THE 00Z-06Z FRIDAY PERIOD WHEN H7 MIXING RATIOS TOWARD 4G/KG ARE PRESENT. AFTER THAT WILL HEAD TOWARD MORE TONED DOWN QPF FM THE UKMET/ECMWF AND SOMEWHAT THE NAM /SUGGESTING AROUND 0.30 TO PERHAPS AS MUCH AS NEAR 0.50 INCH IN THE 06Z-12Z TIME PERIOD WITHIN AXIS OF HEAVIER PRECIP...VERSUS THE WETTER GFS AND GEM-NH. PTYPE AND ULTIMATELY SNOW AMOUNTS...REMAINS AN ISSUE. HOWEVER TREND MAY BE SIGNALING MOSTLY SNOW FOR AT LEAST THE WEST HALF OF THE CWA...ROUGHLY WEST OF IMT TO MQT. FORECAST SOUNDINGS FM NAM ARE NEARLY ISOTHERMAL AND NEAR 0C THROUGH H8 AT IMT AND IWD...BUT ARE SUFFICIENTLY COLD ENOUGH IN THIS LAYER AT CMX AND MQT FOR SNOW. FARTHER EAST...AT MNM/ESC/P53 THE WARM LAYER IS TO H95/1000FT AGL OR HIGHER THROUGH THE OVERNIGHT...BUT COULD LOWER ENOUGH BLO 1000FT AGL TO RESULT IN AT LEAST A MIX OF SNOW OR PERHAPS A TURNOVER TO ONLY SNOW BTWN 06Z AND 12Z. AT ERY...COULD STAY COLD ENOUGH TO KEEP PTYPE MAINLY SNOW LIKELY DEPENDING LARGELY ON SFC TEMPS. THOUGH THE INSOLATION AND BLYR WARMING MAY MAKE IT TOUGH TO ACCUMULATE SNOW INITIALLY LATER THURSDAY AFTN WOULD EXPECT BY EARLY THURSDAY EVENING...INCREASING SNOW RATES AND LOSS OF INSOLATION WILL RESULT IN ACCUMULATIONS INCREASING. SREF OUTPUT BASED ON EXPECTED MODEL SKIN TEMPS INDICATES THAT BY EARLY THURSDAY EVENING...MAJORITY OF ENSEMBLE MEMBERS SUGGEST SNOW WOULD START ACCUMLATING ON ROADS AS WELL...ESPECIALLY IF SNOWFALL RATES PUSH OVER 1 INCH PER HOUR. EXPECT SNOW ACCUMULATIONS OVER MUCH OF INTERIOR CNTRL CWA TO EXCEED 6 INCHES LATE THURSDAY AFTERNOON INTO FRIDAY...WITH POTENTIAL FOR 8 TO 10 INCHES OVER NORTHWEST CWA. BASED ON THE TRENDS FROM THE 12Z MODELS AND AFTER COORDINATION WITH SHORT TERM FORECASTER...WILL BE GOING FOR A WINTER STORM WATCH FOR THE KEWEENAW PENINSULA. IN ADDITION TO HEAVY SNOW...WILL ALSO SEE POTENTIAL FOR BLOWING SNOW AS EAST WINDS GUST 20-30 MPH ON THURSDAY NIGHT INTO EARLY FRIDAY MORNING. IT WILL BE CLOSE FOR SEEING ENOUGH SNOWFALL FOR A WARNING FOR AREAS FROM IRON TO MARQUETTE COUNTIES /CURRENTLY HAVE 4-7 INCHES FALLING MAINLY FROM LATE THURSDAY AFTN THROUGH MIDDAY FRIDAY/...AND POSSIBLY OVER WESTERN UPR MICHIGAN...BUT WILL KEEP WITH SPECIAL WEATHER STATEMENT FOR THESE AREAS ATTM. MID SHIFT CAN ASSESS AGAIN AND DETERMINE WHETHER A WARNING OR ADVISORY IS NEEDED. SLOWER/MORE CLOSED OFF SYSTEM RESULTS IN HIGHER POPS LINGERING INTO FRIDAY AFTN...ESPECIALLY NEAR LK SUPERIOR OVER THE NORTHWEST. SOUNDINGS INDICATE DEEPER MOISTURE BEGINS TO SCOUR OUT FRIDAY EVENING BUT ENOUGH LOW-LEVEL MOISTURE TO H8 WITH TEMPS WITHIN H85 THERMAL TROUGH TOWARD -10C TO KEEP SMALL CHANCES GOING. BY LATE FRIDAY NIGHT...H85 MOISTURE LEAVES THE REGION AND HIGH PRESSURE BECOMES THE BIGGER FACTOR. SHOULD BE GENERALLY CLEAR SKIES ON SATURDAY AS THE HIGH DOMINATES...BUT ENE-NE WINDS OUT OF THE HIGH KEEPS THE COOL AIR LOCKED IN. MIXING TO H9 ALONG THE BORDER SUPPORTS HIGHS INTO THE MID 40S. READINGS ALONG LK SUPERIOR AND OVER MOST OF THE NORTHERN CWA WILL REMAIN IN THE MID-UPR 30S...15-20 DEGREES BELOW NORMAL AND FAIRLY CLOSE TO RECORD LOW MAX TEMPS FOR THIS WEEKEND. REST OF THE EXTENDED...HUDSON BAY HIGH PRESSURE WITH A LOT OF DRY AIR AT H85 HOLDS ITS OWN INTO EARLY NEXT WEEK. COULD BE A PERIOD IN THERE EARLY NEXT WEEK WHERE INCREASE OF MID LEVEL MOISTURE MAY OCCUR. GIVEN THE STRENGTH OF THE HIGH THOUGH...THINKING THAT PRECIP CHANCES WILL BE MINIMAL EARLY THIS WEEK. MODELS ARE TRENDING THAT WAY NOW IT APPEARS. CUTOFF LOW COULD MAKE RUN ACROSS UPPER LAKES BY MIDDLE OF NEXT WEEK...SO THAT IS WHEN CHANCE POPS RETURN TO THE FORECAST. STAYING COOL...ESPECIALLY NEAR LK SUPERIOR WHEN THERE ARE ONSHORE NORTHEAST WINDS. LEANED ON BIAS CORRECTED GUIDANCE FOR MAX TEMPS THROUGH THE EXTENDED. CONSENSUS WAS USED FOR THE REST OF THE FORECAST ELEMENTS INCLUDING POPS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 126 PM EDT WED APR 23 2014 A VERY DRY AIR MASS IS ASSOCIATED WITH SFC HIGH PRES CURRENTLY OVER THE WRN GREAT LAKES. THIS VERY DRY AIR MASS WILL LINGER AT THE LOW LEVELS THRU TONIGHT...ENSURING VFR CONDITIONS CONTINUE AT KIWD/KCMX/KSAW. OTHERWISE...THERE WILL BE INCREASING HIGH CLOUDS THIS AFTERNOON THRU THIS EVENING THEN INCREASING MID CLOUDS LATER TONIGHT THRU THU MORNING AS THE NEXT LOW PRES SYSTEM APPROACHES. RAIN OR MIX OF RAIN AND SNOW WILL PROBABLY REACH KIWD EARLY THU MORNING...THOUGH THERE IS UNCERTAINTY IN TIMING AS LINGERING LOW-LEVEL DRY AIR MASS WILL WORK TO SLOW E/NE PROGRESSION OF PCPN. BY LATE MORNING...PCPN IS LIKELY AT KIWD ALONG WITH MVFR CONDITIONS. PCPN (SNOW OR SNOW/RAIN) SHOULD BE CLOSE TO KCMX/KSAW BY 18Z AND WILL CERTAINLY BEGAN SHORTLY AFTER THIS FCST PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 503 PM EDT WED APR 23 2014 LOW PRESSURE MOVES INTO THE REGION THURSDAY NIGHT INTO FRIDAY. LOW IS TRENDING STRONGER...SO EAST WINDS MAY REACH 30 KTS THURSDAY NIGHT THEN SHIFT TO THE NORTH-NORTHWEST UP TO 30 KTS BY FRIDAY AFTN AFTER THE LOW MOVES TO THE EAST OF LK SUPERIOR. POSSIBLE THAT SOME GALE GUSTS TO 35 KTS MAY OCCUR LATE FRIDAY AFTN INTO FRIDAY EVENING. WINDS DIMINISH BLO 20 KTS FOR THE WEEKEND AS HIGH PRESSURE SETTLES ACROSS ONTARIO AND THE GREAT LAKES. NEXT CHANCE OF STRONGER EAST WINDS WOULD BE ON MONDAY AS THE HIGH SLOWLY MOVES EAST AND LOW PRESSURE DEVELOPS OVER THE PLAINS. && .HYDROLOGY... ISSUED AT 503 PM EDT WED APR 23 2014 RUNOFF FROM RECENT ABOVE NORMAL TEMPS AND SNOWMELT CONTINUES TO FLOW THRU THE GROUND...SO SOME AREA STREAMS AND RIVERS ARE STILL RISING SLOWLY...DESPITE THE COOLER TEMPERATURES THAN WERE SEEN RECENTLY. LOCATIONS THAT STILL ARE ABOVE BANKFUL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR CHASSELL AND THE PAINT RIVER NEAR CRYSTAL FALLS. NEITHER OF THESE RIVERS IS EXPECTED TO REACH FLOOD STAGE IN THE SHORT TERM. REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE. UNSETTLED WEATHER WILL RETURN THURSDAY INTO FRIDAY AS ANOTHER LOW PRESSURE SYSTEM MOVES FROM THE PLAINS TOWARD THE GREAT LAKES... POTENTIALLY ADDING TO RUNOFF. AT THIS POINT THE BEST CHANCE OF SIGNIFICANT PRECIPITATION LOOKS TO BE OVER THE WEST HALF OF UPPER MI...AND SPECIFICALLY THE KEWEENAW PENINSULA...WHERE 0.70-1.25 INCH OF LIQUID WILL BE POSSIBLE BY FRIDAY AFTERNOON. THERE IS SOME UNCERTAINTY ON HOW MUCH WILL FALL AS RAIN AND HOW MUCH WILL FALL AS SNOW...BUT THE BEST CHANCE OF SNOW WILL BE OVER THE KEWEENAW PENINSULA. IF MORE OF THE PRECIPITATION FALLS AS SNOW...RUNOFF WILL BE DELAYED UNTIL WARMER WEATHER RETURNS NEXT WEEK. OVERALL...WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS OVER THE NEXT WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY AFTERNOON FOR MIZ001-003. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...JLA HYDROLOGY...JLA
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1234 PM CDT Wed Apr 23 2014 .SHORT TERM: (Today through Friday) Issued at 342 AM CDT Wed Apr 23 2014 Surface ridge extending from Wisconsin south/southwest into the Mid-Mississippi Valley and back into east Texas will move east today ahead of developing low pressure over the Great Plains. Increasing southerly low level flow will result. All short-range model guidance develops an area of warm advection showers over the eastern Plains and pushes it east northeast into northwest Missouri and Iowa today. Looks possible that the southeast edge of the showers could clip our area, but low level air is pretty dry according to the NAM, GFS, and RUC and the primary thrust of moisture return will be back over western Missouri so have only introduced slight chance PoPs over our northwest counties. We should see highs pretty close to what occurred yesterday even with the warm advection since we`ll be starting out the day cooler than Tuesday morning. The exception will be central Missouri where morning lows should be a bit warmer than areas further east. The shortwave currently digging across the Rockies will move out into the Great Plains tonight and the resulting cold front will move into northwest Missouri around 12Z. Still looks like showers and thunderstorms will be ongoing along and ahead of the front as it moves through the CWFA on Thursday. Diurnal heating will likely be limited due to cloud cover and advancing precip from the west, so instability still looks relatively weak. While there should be enough CAPE for thunderstorms, widespread severe weather does not look likely at this time. Stuck closer to the warmer MAV guidance for highs since morning lows will be around 50 across the area and 15-20 degrees of rise should be attainable in warm advection this time of year regardless of cloud cover. Guidance is in good agreement with pushing the front through the entire area shortly after 00Z. Still have some lingering precip east of the Mississippi River Thursday evening as the front exits, but dry after midnight. Pacific high builds across the region Friday morning. As opposed to a colder Canadian airmass, the Pacific ridge should produce temperatures near or slightly above normal in the upper 40s to low 50s Friday morning. West-southwest flow develops Friday morning as the high scoots quickly into the Tennessee Valley so expect temperatures to rebound into the mid and upper 70s. Carney .LONG TERM: (Saturday through Tuesday) Issued at 342 AM CDT Wed Apr 23 2014 While the medium range guidance is coming into better agreement on the overall synoptic pattern, the smaller scale is still unclear. Generally, a secondary cold front will dip south across the Upper Midwest driven south by the last vestiges of Thursday`s shortwave. The front will stall somewhere across the Midwest on Saturday, though models can`t make up their minds where. GFS stalls the front across south/southwest Missouri Saturday morning, while the ECMWF stalls it out over northern Iowa. The GEM is right about in the middle stalling the front over northern Missouri. All three models have some low level baroclinicity over our area, whether it is the primary baroclinic zone associated with the front (GFS/GEM) or a secondary baroclinic zone left over from the Pacific airmass which will be exiting to the east (EC). Warm advection begins Saturday morning with a 30+ kt low level jet pointed at this baroclinic zone and all three models print out some light precip. Have therefore kept chance pops going in central Missouri, and would not be surprised if subsequent shifts need to bump up pops a bit more across the area if model trends become more consistent. The front remains stalled somewhere between Springfield Missouri and Davenport Iowa depending on which model you believe through Monday as the longwave trof over the Pacific moves inland, and becomes negatively tilted over the Rockies and Great Plains. A strong surface low develops as a result and it moves into the Mississippi Valley Monday night into Tuesday. The upper trof cuts off and becomes stagnant while the surface low tracks across Missouri into the Ohio Valley Tuesday. Pattern is more reminiscent of late Fall or Winter than mid to late Spring. Unsure how likely this is to happen, but this is at least the second run in a row that I`ve seen do this. Will have to wait and see, but right now it looks like a cold/wet end to April. Carney && .AVIATION: (For the 18z TAFs through 18z Thursday Afternoon) Issued at 1223 PM CDT Wed Apr 23 2014 Area of showers currently over western Missouri is expected to weaken this afternoon and is not expected to affect KCOU or KUIN at this time. Main impact will be increasing midlevel cloudiness at terminals. Southeast winds are expected to prevail through the night ahead of next system which will move eastward. Southerly low-level jet of 40-45 knots near 2000 feet AGL over central Missouri and west- central Illinois could produce low- level wind shear and added mention for KCOU and KUIN. For tomorrow...another area of showers with embedded thunderstorms is expected to move into the area from west to east ahead of a cold front from late morning into the early afternoon. Actual frontal passage and accompanied wind shift is likely to be after this valid forecast period. Specifics for KSTL: Increasing midlevel cloudiness is expected through the afternoon at the terminal. Southeast winds are expected to prevail through the night ahead of next system which will move eastward. Low-level jet axis should stay to the west of KSTL precluding mention of LLWS. For tomorrow...another area of showers with embedded thunderstorms is expected to affect Lambert Field around midday. However...actual frontal passage and accompanied wind shift is likely to be just after this valid forecast period. Gosselin && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1229 PM CDT WED APR 23 2014 .SYNOPSIS... ISSUED AT 356 AM CDT WED APR 23 2014 H5 ANALYSIS FROM EARLIER THIS EVENING HAS A RIDGE OF HIGH PRESSURE EXTENDING FROM THE SOUTHERN PLAINS...NWD INTO NORTHERN SASKATCHEWAN. OFF TO THE WEST...AN UPPER LEVEL LOW WAS NOTED OFF THE COAST OF BRITISH COLUMBIA WITH A TROUGH EXTENDING SSE OF THIS FEATURE INTO SOUTHERN CALIFORNIA. WV IMAGERY AS OF 06Z TONIGHT HAS A NICE SHORTWAVE OVER NRN UTAH AND SERN IDAHO. IN ADVANCE OF THIS FEATURE...THUNDERSTORMS WERE PRESENT ACROSS NWRN COLORADO AND SRN WYOMING. FURTHER EAST...ISOLATED THUNDERSTORMS WERE PRESENT OVER SOUTH DAKOTA...AS WELL AS NORTH CENTRAL KS AND PORTIONS OF SOUTH CENTRAL AND SOUTHEASTERN NEBRASKA. THIS ACTIVITY HAS INCREASED SOMEWHAT IN COVERAGE OVER THE PAST 1 TO 2 HRS THANKS TO A 50+KT LOW LEVEL JET WHICH EXTENDS FROM SOUTH CENTRAL INTO NORTH CENTRAL NEBRASKA. AT THE SURFACE...ACROSS WESTERN AND NORTH CENTRAL NEBRASKA...GUSTY SOUTHEASTERLY WINDS WERE PRESENT EAST OF A LINE FROM AINSWORTH TO OGALLALA THANKS TO A SURFACE LOW OVER SERN MT...WITH A SURFACE TROUGH EXTENDING SWD INTO EASTERN COLORADO. SUSTAINED SPEEDS WERE GENERALLY 15 TO 25 MPH...WITH SOME GUSTS UP TO 35 MPH. UNDER PARTLY CLOUDY SKIES...3 AM CDT TEMPERATURES RANGED FROM 53 AT BROKEN BOW TO 60 AT IMPERIAL AND THEDFORD. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 356 AM CDT WED APR 23 2014 OVER THE NEXT 24 HOURS...PRECIPITATION CHANCES AND THE SEVERE THREAT IN THE EASTERN FORECAST AREA ARE THE MAIN FORECAST CONCERN. OTHER CONCERNS CENTER ON WINDS THIS MORNING IN THE EAST...ALONG WITH THE FIRE DANGER THREAT IN THE WEST THIS AFTERNOON. FOR THIS MORNING...THE BEFORE MENTIONED SURFACE TROUGH OF LOW PRESSURE WILL ENTER THE PANHANDLE BY MID MORNING. STRONG SOUTHERLY WINDS WILL CONTINUE ACROSS THE EASTERN QUARTER OF THE FORECAST AREA THROUGH MID MORNING AS A 40 TO 50 KT LOW LEVEL JET REMAINS PRESENT ACROSS THE FAR NERN CWA. THIS FEATURE WILL SLIDE EAST OF THE FORECAST AREA BY 18Z WHILE THE SURFACE TROUGH PUSHES EAST TO A LINE FROM VALENTINE...TO NORTH PLATTE TO HAYES CENTER. GIVEN THE STRONG LOW LEVEL JET THIS MORNING...WE COULD FLIRT WITH WIND ADVISORY CRITERIA WINDS IN THE FAR NORTHEASTERN CWA THROUGH LATE MORNING. RIGHT NOW...BASED ON THE HRRR AND STATISTICAL GUIDANCE...FCST WINDS ARE JUST BELOW ADVISORY CRITERIA AND PLAN ON NO HEADLINES ATTM. WILL CONTINUE TO MONITOR THIS THROUGH SUNRISE AS THE H85 JET MIGRATES FROM THE HIGHWAY 83 CORRIDOR EAST TOWARD SUNRISE. LATER THIS AFTERNOON...A STRONG UPPER LEVEL DISTURBANCE WILL APPROACH WESTERN NEBRASKA. AS CAPPING ERODES DURING THE LATE AFTERNOON HOURS...THUNDERSTORMS ARE EXPECTED TO FIRE INVOF OF THE SURFACE TROUGH. ATTM...THIS FEATURE IS EXPECTED TO BE ALONG A LINE FROM BASSETT TO NORTH PLATTE TO EAST OF HAYES CENTER. STRONG SOUTHERLY WINDS EAST OF THE TROUGH...WILL PUSH PLENTY OF LOW LEVEL MOISTURE NWD FROM CENTRAL KS TDY. WITH MOISTURE IN PLACE...AND STRONG INSTABILITY...THUNDERSTORMS LOOK LIKE A SAFE BET ALONG AND EAST OF THE SURFACE TROUGH THIS AFTERNOON. IN OUR FAR SOUTHEAST AND EASTERN ZONES...SHEAR WILL BE FAVORABLE FOR SEVERE STORMS THIS AFTERNOON INTO THE EVENING HOURS. AT THIS TIME...HAIL AND WINDS WILL BE THE MAIN SEVERE THREAT AS DEEP LAYER WIND SHEAR IS UNIDIRECTIONAL. WITH THE POSITION OF THE BEFORE MENTIONED SURFACE TROUGH...PRECIP CHANCES WILL BE HIGHEST IN FAR EASTERN PORTIONS OF THE FORECAST AREA WITH HIGH CHANCE TO LOW LIKELY POPS ALONG AND EAST OF A LINE FROM ONEILL...TO BROKEN BOW...TO MAYWOOD. POPS WILL DECREASE QUICKLY WEST OF THIS LINE...WITH NO PRECIPITATION EXPECTED WEST OF A LINE FROM VALENTINE...TO SUTHERLAND...TO GRANT. THE SURFACE TROUGH WILL BE FORCED EAST OF THE FORECAST AREA BY MID EVENING...WITH THE THREAT FOR THUNDERSTORMS IN THE EAST ENDING BY MIDNIGHT TONIGHT. WITH RESPECT TO FIRE DANGER THIS AFTERNOON...WEST OF THE SURFACE TROUGH...EXTREME TO NEAR CRITICAL FIRE DANGER WILL BE POSSIBLE LATER THIS AFTERNOON...AS DRIER AIR PUSHES INTO THE PANHANDLE BEHIND THE SURFACE TROUGH. DEW POINTS WILL DROP INTO THE TWENTIES IN THE EASTERN PANHANDLE BY LATE AFTERNOON AND WITH TEMPERATURES IN THE MID TO UPPER 60S EXPECTED...RELATIVE HUMIDITIES WILL DROP TO AROUND 20 PERCENT. BREEZY WESTERLY WINDS MAY BECOME GUSTY LATER THIS AFTERNOON...PARTICULARLY IN THE EASTERN PANHANDLE THANKS TO DECENT 3 HR SURFACE PRESSURE RISES OF 3 TO 5 MB FROM 21Z TO 00Z LATE THIS AFTERNOON. ATTM...EXPECTED MINIMUM RELATIVE HUMIDITIES WILL BE JUST ABOVE RED FLAG CRITERIA SO NO FIRE HEADLINES ARE EXPECTED AT THIS TIME. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 356 AM CDT WED APR 23 2014 DRY AIR WILL BE IN PLACE THURSDAY BEHIND WEDNESDAY/S COLD FRONTAL PASSAGE. WILL BE CLOSE TO RED FLAG CRITERIA...IN WELL MIXED AND DRY ATMOSPHERE. 500M WIND SPEEDS OF 10 TO 20 KTS WILL SUPPORT SUSTAINED SURFACE WIND SPEEDS OF 15 TO 20 MPH...BUT THESE WINDS WILL SLOWLY BE DIMINISHING DURING THE TIME OF LOWEST RELATIVE HUMIDITY. WILL CONTINUE THE MENTION OF THE FIRE WEATHER CONCERN IN THE HAZARDOUS WEATHER OUTLOOK...AND HAVE THE ONCOMING SHIFT TAKE ANOTHER LOOK BEFORE ISSUING ANY TYPE OF FIRE WEATHER HEADLINES. A CHILLY NIGHT EXPECTED THURSDAY NIGHT...AS SURFACE HIGH RIDGE AXIS CROSSES THE AREA AND WINDS DECOUPLE. NOT EXPECTING BELOW FREEZING TEMPERATURES AT THIS POINT...BUT FAVORED LOW SPOTS AND RIVER VALLEYS WILL LIKELY SEE LOWS BOTTOMING OUT IN THE MIDDLE 30S. WARM AIR ADVECTION GETS UNDERWAY IN ERNEST FRIDAY...WITH SOUTHERLY FLOW ADVECTING H85 TEMPERATURES OF 20C INTO SOUTHWEST NEBRASKA BY AFTERNOON. ALL AREAS SHOULD SEE HIGHS INTO THE 70S. STILL SOME CONCERN REGARDING WILDFIRE POTENTIAL...BUT IT APPEARS THAT WINDS WILL REMAIN IN CHECK...AND DEW POINTS WILL BE SLOWLY RISING INTO THE 30S DURING THE AFTERNOON. SOUTHERLY LOW LEVEL JET CRANKS UP FRIDAY NIGHT IN RESPONSE TO DEVELOPING LOW PRESSURE ALONG THE LEE OF THE ROCKIES. THE NAM MODEL IS THE MOST AGGRESSIVE WITH THE MOISTURE RETURN AND STEEP MID LEVEL LAPSE RATES...AND THE MODEL DEVELOPS SOME DECENT MID LEVEL CAPE AS A RESULT. THE OTHER MODELS ARE SLOWER WITH THE MOISTURE RETURN...AND THE MID LEVEL LAPSE RATES ARE NOT AS STEEP. THEREFORE THESE MODELS ARE INDICATING LESS IN THE WAY OF INSTABILITY. WILL CONTINUE THE SLIGHT CHANCE OF SHOWERS IN THE FORECAST...AND WILL ADD AN ISOLATED THUNDER MENTION TO ACCOUNT FOR THE INCREASING MID LEVEL INSTABILITY IN THE NAM. FOR THE WEEKEND...A POTENT UPPER LEVEL TROUGH OF LOW PRESSURE WILL MOVE ONSHORE THE PACIFIC COAST FRIDAY EVENING. THE 23/00Z GFS AND ECMWF MODEL RUNS ARE IN EXCELLENT AGREEMENT...AND HAVE THE BASE OF THE UPPER LEVEL TROUGH SWINGING THOUGH SOUTHEAST CALIFORNIA/WESTERN ARIZONA AT 18Z SATURDAY. AT THE SURFACE...BOTH MODELS RAPIDLY DEEPEN A SURFACE LOW /NEAR 988MB/ DOWNSTREAM IN FAVORED CYCLOGENESIS REGION OF EASTERN COLORADO BY 00Z SUNDAY. THIS WILL HELP DRAW GULF MOISTURE RAPIDLY NORTHWARD INTO THE CENTRAL PLAINS. THE GFS...ECMWF AND THE GEFS ENSEMBLE MEAN REMAIN IN GOOD AGREEMENT THROUGH SUNDAY...AND BRING A POTENT/DYNAMIC NEGATIVELY TILTED UPPER TROUGH INTO THE CENTRAL PLAINS...WITH A CLOSED H5 AND H7 CIRCULATION CENTER ACROSS WESTERN KANSAS. MEANWHILE A DEEP 985MB SURFACE LOW WILL SLOWLY MIGRATE EASTWARD NEAR THE KANSAS/NEBRASKA BORDER THROUGH MONDAY. REGARDING THUNDERSTORM AND PRECIPITATION CHANCES...SEVERE WEATHER SEEMS LIKELY GIVEN SUCH STRONG DYNAMICS AND GOOD MOISTURE. IT WILL OF COURSE HINGE ON WHERE THE BOUNDARIES SET UP. THERE WILL LIKELY BE A SHARP WARM FRONT AND DRY LINE FOR CONVECTION TO FOCUS ON/NEAR. WILL NOT TRY TO PIN DOWN EXACT LOCATION OF THESE FEATURES JUST YET...BUT INDICATIONS ARE THAT BOTH THESE BOUNDARIES MAY BE IN OR VERY NEAR THE FORECAST AREA FOR MUCH OF THE WEEKEND. WITH SUCH A STRONG SYSTEM...THERE WILL ALSO BE A PRONOUNCED DRY SLOT. THE CURRENT STORM TRACK ACROSS NORTHERN KANSAS SUNDAY INTO MONDAY...WOULD FAVOR THE DRY SLOT AIMING MORE AT SOUTHERN/SOUTHEAST NEBRASKA NEBRASKA. THIS IS GOOD NEWS FOR OUR AREA...AS A PERSISTENT SHIELD OF RAIN COULD LINGER FOR MANY HOURS. THIS HAS THE POTENTIAL TO BE A SIGNIFICANT AND SLOW MOVING STORM SYSTEM...AND WILL CONTINUE TO MONITOR THE LATEST TRENDS CLOSELY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1228 PM CDT WED APR 23 2014 WIND CONCERNS WILL BE THE HIGHLIGHT OF THIS FORECAST PERIOD FOR MOST LOCATIONS WEST OF A LINE FROM KIML TO KLBF TO KANW...WHILE THUNDERSTORM POTENTIAL WILL BE A HIGHER THREAT EAST OF THIS LINE LATER THIS AFTERNOON AND TONIGHT. WINDS WILL TURN TO THE NORTHWEST ACROSS ALL OF WESTERN AND CENTRAL NEBRASKA BY THIS EVENING AND WILL REMAIN BREEZY THROUGH MUCH OF THE OVERNIGHT HOURS. WILL GET A REPRIEVE AFTER 06Z IN MOST LOCATIONS...BUT AS THE BOUNDARY LAYER BEGINS MIXING THURSDAY MORNING...EXPECT BREEZY AND GUSTY WINDS TO RETURN. IF STORMS DO DEVELOP LOCALLY...STRONG WIND GUSTS AND HAIL WOULD BE POSSIBLE. BUT...CURRENT INDICATIONS ARE THAT MOST OF THIS ACTIVITY WILL STAY EAST OF THE LOCAL AREA. UNLESS A LOCATION SEES A PASSING SHOWER OR STORMS TONIGHT...CONDITIONS WILL STAY VFR. && .FIRE WEATHER...UPDATED ISSUED AT 1004 AM CDT WED APR 23 2014 CLOSELY WATCHING FIRE WEATHER CONDITIONS ACROSS THE PANHANDLE AND THE WESTERN SANDHILLS /FIRE ZONE 204/ FOR THIS AFTERNOON. DRY AIR WILL MOVE INTO THESE AREAS THROUGH THE DAY AS A COLD FRONT...NOW LOCATED FROM FAR NORTHEAST COLORADO /WEST OF KHEQ/ NORTH THROUGH THE EASTERN PANHANDLE AND INTO WESTERN SOUTH DAKOTA /NEAR KPHP/. DEEP MIXING IS EXPECTED IN THESE AREAS THIS AFTERNOON...UP TO 700MB AND BELIEVE WINDS MAY BE A BIT STRONGER AND DEWPOINTS A BIT DRIER THAN HAD BEEN ORIGINALLY THOUGHT. USING A MIXED LAYER DEWPOINT...SOME PLACES COULD SEE VALUES DOWN NEAR 20F OR EVEN THE LOW TEENS. THE FORECAST DOESN/T GO THIS LOW AT THIS TIME...BUT WILL BE WATCHING CLOSELY IN THE COMING HOURS IF BY CHANCE A SHORT FUSED RED FLAG WARNING MAY BE NEEDED. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...TAYLOR AVIATION...BROOKS FIRE WEATHER...BROOKS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
701 PM EDT WED APR 23 2014 .SYNOPSIS... HIGH PRESSURE WILL SLOWLY BUILD INTO THE NORTH COUNTRY BY THURSDAY WITH CLEARING SKIES AND NEAR NORMAL TEMPERATURES EXPECTED. THE NEXT CHANCE FOR SHOWERS WILL BE FRIDAY NIGHT INTO SATURDAY ALONG WITH THE ARRIVAL OF COOLER AIR FOR THE WEEKEND. A FEW MOUNTAINS SNOW SHOWERS WILL BE POSSIBLE ON SATURDAY NIGHT AND AGAIN ON SUNDAY NIGHT...BUT ONLY MINOR ACCUMULATION ANTICIPATED. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 340 PM EDT WEDNESDAY...WATER VAPOR SHOWS MID/UPPER LVL TROF ACRS THE NE CONUS SLOWLY LIFTING TWD EASTERN CANADA OVERNIGHT...WITH LARGE AREA OF SUBSIDENCE DEVELOPING ACRS THE CENTRAL GREAT LAKES. THIS WL SLOWLY MOVE TWD OUR REGION AFT MIDNIGHT WITH SOME CLRING ACRS OUR WESTERN CWA. MEANWHILE...THE COMBINATION OF CYCLONIC FLW AND EMBEDDED 5H VORTS WL RESULT IN SOME LIGHT RAIN/SNOW SHOWERS ACRS THE MTNS TONIGHT. WL USE THE BTV 4KM AND RAP 13 TO HIGHLIGHT UPSLOPE PRECIP THIS EVENING...BUT OVERALL QPF/SNOWFALL WL BE LIGHT WITH ONLY ACCUMULATION ABOVE 2000 FT. THINKING QPF WL BE A COUPLE HUNDREDTHS OF AN INCH AT BEST. WL MENTION CHC TO LIKELY POPS ACRS THE NORTHERN DACKS AND NORTHERN/CENTRAL GREEN MTNS IN VT THRU 06Z...THEN TAPER OFF TWD MORNING. SOUNDINGS SHOW GOOD MIXING TONIGHT AND PLENTY OF LEFTOVER RH BTWN SFC AND 700MB RESULTING IN LOTS OF CLOUDS...SO THINKING LOWS WL RANGE FROM UPPER 20S MTNS/SLK TO M/U 30S WARMER VALLEYS. I REALIZE GUIDANCE FOR SLK IS AROUND 20F...BUT THIS SEEMS WAY TOO COLD BASED ON CLOUDS/WINDS...AND CRNT SFC DWPTS IN THE M30S. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... AS OF 340 PM EDT WEDNESDAY...MAIN FCST CONCERNS WL BE FIRE WX RELATED ON THURSDAY...FOLLOWED BY ARRIVAL OF PRECIP LATE FRIDAY. SEE FIRE WX SECTION BELOW FOR DETAILS REGARDING WINDS/RH`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
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
340 PM EDT WED APR 23 2014 .SYNOPSIS... HIGH PRESSURE WILL SLOWLY BUILD INTO THE NORTH COUNTRY BY THURSDAY WITH CLEARING SKIES AND NEAR NORMAL TEMPERATURES EXPECTED. THE NEXT CHANCE FOR SHOWERS WILL BE FRIDAY NIGHT INTO SATURDAY ALONG WITH THE ARRIVAL OF COOLER AIR FOR THE WEEKEND. A FEW MOUNTAINS SNOW SHOWERS WILL BE POSSIBLE ON SATURDAY NIGHT AND AGAIN ON SUNDAY NIGHT...BUT ONLY MINOR ACCUMULATION ANTICIPATED. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 340 PM EDT WEDNESDAY...WATER VAPOR SHOWS MID/UPPER LVL TROF ACRS THE NE CONUS SLOWLY LIFTING TWD EASTERN CANADA OVERNIGHT...WITH LARGE AREA OF SUBSIDENCE DEVELOPING ACRS THE CENTRAL GREAT LAKES. THIS WL SLOWLY MOVE TWD OUR REGION AFT MIDNIGHT WITH SOME CLRING ACRS OUR WESTERN CWA. MEANWHILE...THE COMBINATION OF CYCLONIC FLW AND EMBEDDED 5H VORTS WL RESULT IN SOME LIGHT RAIN/SNOW SHOWERS ACRS THE MTNS TONIGHT. WL USE THE BTV 4KM AND RAP 13 TO HIGHLIGHT UPSLOPE PRECIP THIS EVENING...BUT OVERALL QPF/SNOWFALL WL BE LIGHT WITH ONLY ACCUMULATION ABOVE 2000 FT. THINKING QPF WL BE A COUPLE HUNDREDTHS OF AN INCH AT BEST. WL MENTION CHC TO LIKELY POPS ACRS THE NORTHERN DACKS AND NORTHERN/CENTRAL GREEN MTNS IN VT THRU 06Z...THEN TAPER OFF TWD MORNING. SOUNDINGS SHOW GOOD MIXING TONIGHT AND PLENTY OF LEFTOVER RH BTWN SFC AND 700MB RESULTING IN LOTS OF CLOUDS...SO THINKING LOWS WL RANGE FROM UPPER 20S MTNS/SLK TO M/U 30S WARMER VALLEYS. I REALIZE GUIDANCE FOR SLK IS AROUND 20F...BUT THIS SEEMS WAY TOO COLD BASED ON CLOUDS/WINDS...AND CRNT SFC DWPTS IN THE M30S. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... AS OF 340 PM EDT WEDNESDAY...MAIN FCST CONCERNS WL BE FIRE WX RELATED ON THURSDAY...FOLLOWED BY ARRIVAL OF PRECIP LATE FRIDAY. SEE FIRE WX SECTION BELOW FOR DETAILS REGARDING WINDS/RH`S AND RECENT DRY SPELL ACRS PARTS OF THE REGION. THE COMBINATION OF DEPARTING SFC LOW PRES AND BUILDING HIGH PRES WL RESULT IN BREEZY TO GUSTY WEST TO NORTHWEST WINDS OF 15 TO 25 MPH WITH LOCALIZED GUSTY TO 35 MPH. SOUNDINGS SHOW TOP OF THE MIXED LAYER AROUND 35 KNOTS ON THURSDAY WITH BOTTOM LAYER WINDS AROUND 30 KNOTS...SUPPORTING THIS GUSTY WINDS. STILL THINKING SOME CLOUDS WL LINGER ACRS THE NORTHERN/CENTRAL MTNS OF VT...INCLUDING THE NEK ON THURS...BUT CLRING SKIES WL DEVELOP BY MIDDAY ASSOCIATED WITH SFC HIGH PRES. PROGGED 85H TEMPS BTWN -2C AND -4C...SUPPORT HIGHS ONLY IN THE M/U 40S MTNS TO L/M50S WARMER VALLEYS ON THURSDAY. THE COMBINATION OF CLR SKIES AND CALM WINDS WITH SFC HIGH PRES OVERHEAD WL RESULT IN COOL TEMPS THURS NIGHT. LOWS WL RANGE IN THE 20S COLDER MTN VALLEYS TO L/M 30S WARMER/WIDER CPV/SLV VALLEYS. MID/UPPER LVL RIDGE BREAKS DOWN ON FRIDAY INTO FRIDAY NIGHT WITH NEXT SYSTEM APPROACHING THE NE CONUS. FEEL INITIAL S/W ENERGY AND ASSOCIATED RIBBON OF 850 TO 500MB RH WL DISSIPATE AS IT ENCOUNTER RIDGE/DRY AIR ACRS OUR REGION. WL MENTION LOW CHC POPS LATE FRIDAY AFTN ACRS OUR WESTERN CWA AND INCREASE POPS OVERNIGHT AHEAD OF BETTER DYNAMICS. TEMPS WL WARM TO NEAR NORMAL ON FRIDAY AND STAY MAINLY IN THE 40S FRIDAY NIGHT WITH THE CLOUDS AND DEVELOPING SOUTHERLY WINDS. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 330 PM EDT WEDNESDAY...LOOKING AT UNSETTLED WEATHER FOR THE UPCOMING WEEKEND AS UPPER LEVEL LOW PRESSURE MOVING THROUGH THE GREAT LAKES FRIDAY NIGHT CLOSES OFF OVER THE NORTH COUNTRY SATURDAY MORNING...AND SHIFTS OFFSHORE SUNDAY AFTERNOON. THE RESULT WILL BE PERIODS OF SHOWERS THROUGH SATURDAY NIGHT...WITH CLOUDY...COOL AND BRISK CONDITIONS FOR SUNDAY. THEREAFTER...BLOCKING PATTERN LOOKS TO SETUP ACROSS THE CONUS WITH AFOREMENTIONED CLOSED LOW STALLING OFF THE EASTERN SEABOARD... ANOTHER CLOSED LOW DEVELOPING OVER THE CENTRAL ROCKIES...AND A HIGHLY AMPLIFIED RIDGE IN-BETWEEN. WHILE WE SHOULD SEE GENERALLY DRY CONDITIONS THROUGH THIS PERIOD FOR NEXT MONDAY THROUGH WEDNESDAY AS THE ENTIRE SETUP SLOWLY SHIFTS EASTWARD...IF AND WHEN THE RIDGE BREAKS DOWN THE POTENTIAL EXISTS FOR A MULTI- DAY RAIN EVENT AS THE ROCKIES LOW SHIFTS EAST AND TAPS INTO RICH GULF MOISTURE. TEMPS WILL BE GENERALLY NEAR NORMAL WITH HIGHS IN THE 50S AND LOWS IN THE 30S AND 40S. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...BASICALLY A PERSISTENCE FORECAST THROUGH THE NEXT 12 HOURS AS THE FORECAST AREA REMAINS UNDER THE INFLUENCE OF A DEPARTING UPPER LOW/TROUGH OVER THE NORTHEAST. THROUGH 12Z THURSDAY...EXPECTING MAINLY VFR CONDITIONS AT KMSS/KBTV/KPBG WHILE MVFR WILL REMAIN AT KRUT THROUGH 00Z...AND THROUGH 12Z AT KSLK/KMPV. RADAR SHOWING LITTLE IN THE WAY OF PRECIP AT THIS TIME...THOUGH MAY SEE SOME SPOTTY SHOWERS/DRIZZLE OVERNIGHT. HAVE LEFT OUT OF TAFS FOR NOW DUE TO TIMING AND AREAL COVERAGE UNCERTAINTY. AFTER 12Z THURSDAY...VFR CONDITIONS ARE EXPECTED AREA-WIDE WITH SKC-SCT CIGS AS HIGH PRESSURE BUILDS IN. PRESSURE GRADIENT TIGHTENS BETWEEN THE DEPARTING LOW AND BUILDING HIGH SO NW WINDS WILL BE QUITE BRISK...GUSTING 20-30KTS. OUTLOOK 18Z THURSDAY THROUGH MONDAY... 18Z THU THRU 00Z SAT...VFR UNDER HIGH PRESSURE. CONTINUED GUSTS FROM THE NW 18Z THU THRU 12Z FRI. 00Z SAT THRU 00Z MON...MAINLY VFR WITH CHANCE OF MVFR SHOWERS ASSOCIATED WITH A WEAK LOW PASSAGE. MONDAY...MAINLY VFR UNDER SCT-BKN SKIES. && .FIRE WEATHER... FIRE WEATHER CONCERNS INCREASE ON THURSDAY FOR ELEVATIONS BELOW 1500 FEET ACROSS SOUTHERN VT...DUE TO THE COMBINATION OF THE RECENT DRY SPELL...EXPECTED BREEZY WINDS...AND LOW MIN RH VALUES. THE LAST MEASURABLE PRECIP AT SPRINGFIELD VT ASOS WAS 4/15/14...WHEN 0.70" OCCURRED...SINCE THEN ONLY A TRACE OF PRECIP HAS BEEN OBSERVED. SIMILAR CONDITIONS HAVE BEEN NOTED AT RUTLAND AWOS SITE. THIS HAS RESULTED IN SIGNIFICANT DRYING OF THE FINE FUELS PER LOCAL FOREST CONTACTS BELOW 1500 FEET...WHERE GREEN UP HAS NOT OCCURRED. MEANWHILE...ABOVE 1500 FEET MOST OF THE FINE FUELS AND LEAF LITTER IS COMPRESSED FROM RECENT SNOW PACK OR STILL WET. MOST OF CENTRAL/NORTHERN VT MTNS AND PARTS OF NORTHERN NY HAVE RECEIVED MEASURABLE PRECIP OVER THE PAST 2 TO 5 DAYS OR SNOW PACK IS STILL ON THE GROUND ABOVE 2000 FEET...RESULTING IN LIMITED THREAT. BREEZY WEST TO NORTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS TO 30 MPH ARE EXPECTED ACRS THE HIGHER TRRN...PARTS OF THE CT RIVER VALLEY...AND CHAMPLAIN VALLEY ON THURSDAY. IN ADDITION...MIN AFTN RH VALUES WL DROP BTWN 25% AND 35% BTWN 1 PM AND 5PM ON THURSDAY ACRS THIS AREA...WITH ISOLATED READINGS OF 20% NEAR SPRINGFIELD VT POSSIBLE. THESE CONDITIONS COMBINED WITH THE OVERALL DRYING OF GRASSES...TWIGS...AND DEBRIS SUCH AS DEAD LEAVES FROM LAST FALL AND YOU WILL WANT TO PAY CLOSE ATTENTION TO ANY OUTDOOR BURNING YOU MAY BE ATTEMPTING ON THURSDAY. MONITOR WEATHER CONDITIONS...DO NOT LEAVE YOUR BRUSH OR DEBRIS PILE UNATTENDED...AND HEED ANY ADVICE FROM YOUR LOCAL FIRE WARDEN. GIVEN THE SMALL GEOGRAPHICAL AREA WITH FAVORABLE FUEL CONDITIONS AND MARGINAL FIRE WEATHER PARAMETERS...NO FIRE WEATHER WATCH WILL BE ISSUED WITH THIS PACKAGE...BUT WILL HIGHLIGHT IN HWO PRODUCT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...TABER NEAR TERM...TABER SHORT TERM...TABER LONG TERM...LAHIFF AVIATION...LAHIFF FIRE WEATHER...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
330 PM EDT WED APR 23 2014 .SYNOPSIS... LOW PRESSURE WILL CONTINUE TO AFFECT THE NORTH COUNTRY THROUGH TONIGHT...PRODUCING CLOUDY SKIES AND ISOLATED TO SCATTERED SHOWERS. THIS WILL BE FOLLOWED BY HIGH PRESSURE BUILDING OVER THE AREA FOR THURSDAY AND REMAINING INTO FRIDAY MORNING. A LOW PRESSURE SYSTEM APPROACHES DURING THE DAY FRIDAY AND AFFECTS THE REGION RIGHT INTO THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 127 PM EDT WEDNESDAY...MINOR UPDATE TO REDUCE POPS ACRS THE CPV/CT RIVER VALLEY AND PARTS OF NORTHERN NY. CRNT RADAR AND SUMMIT WEB CAMS SHOW VERY LIGHT PRECIP FALLING WITH FREEZING LVL AROUND 3000 FT. BOTH RAP AND BTV 4KM CONT TO SUPPORT SOME LIGHT RAIN/SNOW SHOWERS THIS AFTN/EVENING ASSOCIATED WITH FAVORABLE UPSLOPE FLW. HOWEVER...SFC DWPTS CONT TO DRY WITH READINGS IN THE 20S/30S WHICH WL LIMIT AREAL COVERAGE/INTENSITY OF PRECIP TODAY. OTHERWISE...TEMPS ARE HOLDING IN THE U30S MTNS TO U40S WARMER VALLEYS. PREVIOUS DISCUSSION...WITH SFC LOW SHIFTING TO THE NE...UPPER LOW WILL MOVE ACROSS THE REGION TODAY...SETTING THE AREA UP FOR N/NW FLOW TODAY. FOCUS OF PRECIP WILL BE OVER HIGHER TRRN DUE TO UPSLOPE/OROGRAPHIC CONDITIONS...WITH TEMPS IN THE VALLEY WARM ENOUGH FOR -SHRA. BUT HIGHER TRRN WILL SEE SOME RASN MIX. WINDS MAY ALSO BECM GUSTY FOR THE LATTER HALF OF THE DAY AS 40-50KT JET AT 850MB EXTENDS INTO THE SRN 2/3 OF THE FA. EXPECT QPF AMTS AROUND ONE TO TWO TENTHS OF AN INCH...WITH ABOUT AN INCH OF SNOWFALL PSBL OVER THE HIGHER TRRN. PRECIP WILL TAPER OFF FROM WEST TO EAST WITH APPROACH OF SFC HIGH PRESSURE FROM THE CENTRAL PORTION OF THE COUNTRY LATE TODAY INTO THIS EVENING. SHOWERS LOOK TO LINGER INTO THE OVERNGT ACROSS THE NEK. CLOUDY SKIES FROM LLVL MOISTURE AND UPPER LVL TROUGH TRAVERSING THE AREA...ALONG WITH COOLER N/NW FLOW WILL KEEP MAX TEMPS IN THE 40S-L50S IN THE VALLEYS AND 30S AT THE SUMMITS TODAY. && .SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY NIGHT/... AS OF 420 AM EDT WEDNESDAY...PRECIP CONTINUES TO TAPER OFF THIS EVENING...LINGERING MOSTLY IN THE NEK IN THE FORM OF RASN MIX AS TEMPS FALL INTO THE L-M30S IN THE VALLEYS AND 20S IN THE HIGHER TRRN. SFC HIGH PRESSURE BUILDS IN FROM THE NW...WITH UPPER LVL RIDGING COINCIDING WILL LEAD TO 925MB TEMPS INCREASING TO 2C-3C THURSDAY. GENERALLY CLEARING SKIES BUT CONTINUED N/NW FLOW WILL SEE MAX TEMPS IN THE U40S-M50S IN THE VALLEYS AND U30S-L40S IN THE HIGHER TRRN. RIDGING WILL ALSO PUSH WEDNESDAYS 850MB JET EWD...AT 30-45KTS OVER SRN AND ERN VT. CLOSER TO THE SFC...925MB WINDS FOR THIS AREA AROUND 28-35KTS. WITH DRIER AIR FILTERING IN AND GUSTY WINDS PSBL...FINER FUELS WILL DRY MAINLY ACROSS SRN PORTIONS OF FA...BUT THIS WILL BE HIGHLY DEPENDENT ON HOW MUCH QPF RESULTS TODAY AND TONIGHT. THURSDAY NGT...WINDS SUBSIDE WITH RIDGE CRESTING OVER THE REGION AND CLEAR SKIES RESULTING IN COLD OVERNIGHT MIN TEMPS...20S-L30S. WARMTH REBOUNDS ON FRIDAY WITH 925MB TEMPS REACHING 7C-9C IN SOUTHERLY FLOW. ANOTHER SFC LOW WILL APPROACH FROM THE GREAT LAKES REGION...BRINGING MORE PRECIP TO THE REGION FOR THE LATTER HALF OF FRIDAY/FRIDAY NGT. MAX TEMPS WILL SEE U50S-L60S. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 330 PM EDT WEDNESDAY...LOOKING AT UNSETTLED WEATHER FOR THE UPCOMING WEEKEND AS UPPER LEVEL LOW PRESSURE MOVING THROUGH THE GREAT LAKES FRIDAY NIGHT CLOSES OFF OVER THE NORTH COUNTRY SATURDAY MORNING...AND SHIFTS OFFSHORE SUNDAY AFTERNOON. THE RESULT WILL BE PERIODS OF SHOWERS THROUGH SATURDAY NIGHT...WITH CLOUDY...COOL AND BRISK CONDITIONS FOR SUNDAY. THEREAFTER...BLOCKING PATTERN LOOKS TO SETUP ACROSS THE CONUS WITH AFOREMENTIONED CLOSED LOW STALLING OFF THE EASTERN SEABOARD... ANOTHER CLOSED LOW DEVELOPING OVER THE CENTRAL ROCKIES...AND A HIGHLY AMPLIFIED RIDGE IN-BETWEEN. WHILE WE SHOULD SEE GENERALLY DRY CONDITIONS THROUGH THIS PERIOD FOR NEXT MONDAY THROUGH WEDNESDAY AS THE ENTIRE SETUP SLOWLY SHIFTS EASTWARD...IF AND WHEN THE RIDGE BREAKS DOWN THE POTENTIAL EXISTS FOR A MULTI- DAY RAIN EVENT AS THE ROCKIES LOW SHIFTS EAST AND TAPS INTO RICH GULF MOISTURE. TEMPS WILL BE GENERALLY NEAR NORMAL WITH HIGHS IN THE 50S AND LOWS IN THE 30S AND 40S. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...BASICALLY A PERSISTENCE FORECAST THROUGH THE NEXT 12 HOURS AS THE FORECAST AREA REMAINS UNDER THE INFLUENCE OF A DEPARTING UPPER LOW/TROUGH OVER THE NORTHEAST. THROUGH 12Z THURSDAY...EXPECTING MAINLY VFR CONDITIONS AT KMSS/KBTV/KPBG WHILE MVFR WILL REMAIN AT KRUT THROUGH 00Z...AND THROUGH 12Z AT KSLK/KMPV. RADAR SHOWING LITTLE IN THE WAY OF PRECIP AT THIS TIME...THOUGH MAY SEE SOME SPOTTY SHOWERS/DRIZZLE OVERNIGHT. HAVE LEFT OUT OF TAFS FOR NOW DUE TO TIMING AND AREAL COVERAGE UNCERTAINTY. AFTER 12Z THURSDAY...VFR CONDITIONS ARE EXPECTED AREA-WIDE WITH SKC-SCT CIGS AS HIGH PRESSURE BUILDS IN. PRESSURE GRADIENT TIGHTENS BETWEEN THE DEPARTING LOW AND BUILDING HIGH SO NW WINDS WILL BE QUITE BRISK...GUSTING 20-30KTS. OUTLOOK 18Z THURSDAY THROUGH MONDAY... 18Z THU THRU 00Z SAT...VFR UNDER HIGH PRESSURE. CONTINUED GUSTS FROM THE NW 18Z THU THRU 12Z FRI. 00Z SAT THRU 00Z MON...MAINLY VFR WITH CHANCE OF MVFR SHOWERS ASSOCIATED WITH A WEAK LOW PASSAGE. MONDAY...MAINLY VFR UNDER SCT-BKN SKIES. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...KGM/JN NEAR TERM...TABER SHORT TERM...KGM LONG TERM...LAHIFF AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
132 PM EDT WED APR 23 2014 .SYNOPSIS... LOW PRESSURE WILL CONTINUE TO AFFECT THE NORTH COUNTRY THROUGH TONIGHT...PRODUCING CLOUDY SKIES AND ISOLATED TO SCATTERED SHOWERS. THIS WILL BE FOLLOWED BY HIGH PRESSURE BUILDING OVER THE AREA FOR THURSDAY AND REMAINING INTO FRIDAY MORNING. A LOW PRESSURE SYSTEM APPROACHES DURING THE DAY FRIDAY AND AFFECTS THE REGION RIGHT INTO THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 127 PM EDT WEDNESDAY...MINOR UPDATE TO REDUCE POPS ACRS THE CPV/CT RIVER VALLEY AND PARTS OF NORTHERN NY. CRNT RADAR AND SUMMIT WEB CAMS SHOW VERY LIGHT PRECIP FALLING WITH FREEZING LVL AROUND 3000 FT. BOTH RAP AND BTV 4KM CONT TO SUPPORT SOME LIGHT RAIN/SNOW SHOWERS THIS AFTN/EVENING ASSOCIATED WITH FAVORABLE UPSLOPE FLW. HOWEVER...SFC DWPTS CONT TO DRY WITH READINGS IN THE 20S/30S WHICH WL LIMIT AREAL COVERAGE/INTENSITY OF PRECIP TODAY. OTHERWISE...TEMPS ARE HOLDING IN THE U30S MTNS TO U40S WARMER VALLEYS. PREVIOUS DISCUSSION...WITH SFC LOW SHIFTING TO THE NE...UPPER LOW WILL MOVE ACROSS THE REGION TODAY...SETTING THE AREA UP FOR N/NW FLOW TODAY. FOCUS OF PRECIP WILL BE OVER HIGHER TRRN DUE TO UPSLOPE/OROGRAPHIC CONDITIONS...WITH TEMPS IN THE VALLEY WARM ENOUGH FOR -SHRA. BUT HIGHER TRRN WILL SEE SOME RASN MIX. WINDS MAY ALSO BECM GUSTY FOR THE LATTER HALF OF THE DAY AS 40-50KT JET AT 850MB EXTENDS INTO THE SRN 2/3 OF THE FA. EXPECT QPF AMTS AROUND ONE TO TWO TENTHS OF AN INCH...WITH ABOUT AN INCH OF SNOWFALL PSBL OVER THE HIGHER TRRN. PRECIP WILL TAPER OFF FROM WEST TO EAST WITH APPROACH OF SFC HIGH PRESSURE FROM THE CENTRAL PORTION OF THE COUNTRY LATE TODAY INTO THIS EVENING. SHOWERS LOOK TO LINGER INTO THE OVERNGT ACROSS THE NEK. CLOUDY SKIES FROM LLVL MOISTURE AND UPPER LVL TROUGH TRAVERSING THE AREA...ALONG WITH COOLER N/NW FLOW WILL KEEP MAX TEMPS IN THE 40S-L50S IN THE VALLEYS AND 30S AT THE SUMMITS TODAY. && .SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY/... AS OF 420 AM EDT WEDNESDAY...PRECIP CONTINUES TO TAPER OFF THIS EVENING...LINGERING MOSTLY IN THE NEK IN THE FORM OF RASN MIX AS TEMPS FALL INTO THE L-M30S IN THE VALLEYS AND 20S IN THE HIGHER TRRN. SFC HIGH PRESSURE BUILDS IN FROM THE NW...WITH UPPER LVL RIDGING COINCIDING WILL LEAD TO 925MB TEMPS INCREASING TO 2C-3C THURSDAY. GENERALLY CLEARING SKIES BUT CONTINUED N/NW FLOW WILL SEE MAX TEMPS IN THE U40S-M50S IN THE VALLEYS AND U30S-L40S IN THE HIGHER TRRN. RIDGING WILL ALSO PUSH WEDNESDAYS 850MB JET EWD...AT 30-45KTS OVER SRN AND ERN VT. CLOSER TO THE SFC...925MB WINDS FOR THIS AREA AROUND 28-35KTS. WITH DRIER AIR FILTERING IN AND GUSTY WINDS PSBL...FINER FUELS WILL DRY MAINLY ACROSS SRN PORTIONS OF FA...BUT THIS WILL BE HIGHLY DEPENDENT ON HOW MUCH QPF RESULTS TODAY AND TONIGHT. THURSDAY NGT...WINDS SUBSIDE WITH RIDGE CRESTING OVER THE REGION AND CLEAR SKIES RESULTING IN COLD OVERNIGHT MIN TEMPS...20S-L30S. WARMTH REBOUNDS ON FRIDAY WITH 925MB TEMPS REACHING 7C-9C IN SOUTHERLY FLOW. ANOTHER SFC LOW WILL APPROACH FROM THE GREAT LAKES REGION...BRINGING MORE PRECIP TO THE REGION FOR THE LATTER HALF OF FRIDAY/FRIDAY NGT. MAX TEMPS WILL SEE U50S-L60S. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 455 AM EDT WEDNESDAY...ECMWF AND GFS MODELS SHOW MOISTURE FROM A WEAK FRONTAL SYSTEM WILL MOVE INTO THE REGION FRIDAY NIGHT... SO HAVE BOOSTED POPS UP TO LIKELY. ON SATURDAY...ECMWF AND GFS MODELS SHOWING AN UPPER TROUGH AND CLOSED UPPER LOW WILL DIG SOUTHEAST FROM CANADA ON SATURDAY. GFS IS MUCH SHARPER WITH THE UPPER TROUGH THAN THE ECMWF MODEL AND ALSO HAS THE CLOSED UPPER LOW OVER THE FORECAST AREA ON SATURDAY...WHILE THE ECMWF HAS THIS FEATURE FURTHER NORTH ACROSS QUEBEC ON SATURDAY. WILL CONTINUE WITH LIKELY POPS FOR SHOWERS ON SATURDAY. AREA TO REMAIN UNDER CYCLONIC FLOW ON SUNDAY...SO WILL KEEP IN SLIGHT TO LOW CHANCE POPS ON SUNDAY FOR SHOWERS. ECMWF AND GFS MODEL SUGGESTING A MAINLY DRY FORECAST FOR MONDAY AND MONDAY NIGHT...WITH JUST SLIGHT CHANCE POPS FOR SHOWERS ACROSS NORTHEAST VERMONT ON MONDAY. ON TUESDAY...GFS AND ECMWF MODELS HAVE DIFFERING SOLUTIONS...LEADING TO LOW FORECASTER CONFIDENCE FOR TUESDAY. GFS MODEL HAS THE REGION IN AN OMEGA BLOCK ON TUESDAY WITH A CLOSED UPPER LOW SOUTH OF NOVA SCOTIA AND ANOTHER CLOSED UPPER LOW OVER THE MID MISSISSIPPI VALLEY. THIS SOLUTION WOULD MEAN A DRY FORECAST FOR THE REGION ON TUESDAY. HOWEVER...ECMWF MODEL HAS THE CLOSED UPPER LOW ON TUESDAY WELL SOUTH OF NEWFOUNDLAND...WITH AN OPEN TROUGH OF THE MISSISSIPPI VALLEY. THIS SOLUTION WOULD ALLOW FOR MOISTURE FROM THE SOUTHEASTERN U.S TO MOVE INTO THE REGION ON TUESDAY WITH SHOWERS LIKELY. GIVEN MODEL DIFFERENCES...FOR NOW WILL GO WITH SLIGHT CHANCE POPS FOR SHOWERS ON TUESDAY. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...BASICALLY A PERSISTENCE FORECAST THROUGH THE NEXT 12 HOURS AS THE FORECAST AREA REMAINS UNDER THE INFLUENCE OF A DEPARTING UPPER LOW/TROUGH OVER THE NORTHEAST. THROUGH 12Z THURSDAY...EXPECTING MAINLY VFR CONDITIONS AT KMSS/KBTV/KPBG WHILE MVFR WILL REMAIN AT KRUT THROUGH 00Z...AND THROUGH 12Z AT KSLK/KMPV. RADAR SHOWING LITTLE IN THE WAY OF PRECIP AT THIS TIME...THOUGH MAY SEE SOME SPOTTY SHOWERS/DRIZZLE OVERNIGHT. HAVE LEFT OUT OF TAFS FOR NOW DUE TO TIMING AND AREAL COVERAGE UNCERTAINTY. AFTER 12Z THURSDAY...VFR CONDITIONS ARE EXPECTED AREA-WIDE WITH SKC-SCT CIGS AS HIGH PRESSURE BUILDS IN. PRESSURE GRADIENT TIGHTENS BETWEEN THE DEPARTING LOW AND BUILDING HIGH SO NW WINDS WILL BE QUITE BRISK...GUSTING 20-30KTS. OUTLOOK 18Z THURSDAY THROUGH MONDAY... 18Z THU THRU 00Z SAT...VFR UNDER HIGH PRESSURE. CONTINUED GUSTS FROM THE NW 18Z THU THRU 12Z FRI. 00Z SAT THRU 00Z MON...MAINLY VFR WITH CHANCE OF MVFR SHOWERS ASSOCIATED WITH A WEAK LOW PASSAGE. MONDAY...MAINLY VFR UNDER SCT-BKN SKIES. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...KGM/JN NEAR TERM...TABER SHORT TERM...KGM LONG TERM...WGH AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
104 PM CDT WED APR 23 2014 .UPDATE... ISSUED AT 104 PM CDT WED APR 23 2014 UPDATED THE FORECAST TO EXPAND THE WIND ADVISORY IN TIME (BY 3 HOURS) AND SPACE (3 COUNTIES TO THE NORTHWEST) AS WINDS HAVE BEEN STRONGER THAN MODELS HAVE BEEN FORECASTING. THE SHORT RANGE MODELS HAVE ALSO BEEN TOO FAST WITH PUSHING THE SURFACE LOW/BOUNDARY THOUGH THE CWA. THE UPDATED WIND HEADLINES AND PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 957 AM CDT WED APR 23 2014 THE CENTER OF A SURFACE CYCLONE/TROUGH HAS NOW ENTERED SOUTHWESTERN NORTH DAKOTA. SURFACE GRADIENT WINDS HAVE COME DOWN A BIT OVER WESTERN NORTH DAKOTA AS A RESULT. HOWEVER...WIND ADVISORY CONDITIONS CONTINUE OVER THE CENTRAL AND EASTERN PART OF THE STATE. AS A RESULT...WILL CONTINUE WITH THE CURRENT WIND HEADLINES FOR THIS UPDATE. THE 12Z HRRR PROGS RAIN SHOWER REDEVELOPMENT OVER SOUTHWESTERN NORTH DAKOTA BETWEEN THE 16Z-21Z PERIOD AS THE LOW LIFTS NORTH. RAPID CITY RADAR IS ALREADY SHOWING THIS ACTIVITY DEVELOPING AS OF THIS WRITING. THEREFORE...INCREASED POPS OVER SOUTHWESTERN NORTH DAKOTA FOR LATE MORNING/EARLY AFTERNOON BASED ON CURRENT OBS AND MESOSCALE MODEL TRENDS. ALSO MODIFIED THE FIRST PERIOD WEATHER GRIDS TO GO FROM UNCERTAINTY WORDING TO COVERAGE WORDING. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 642 AM CDT WED APR 23 2014 NO SIGNIFICANT UPDATES TO THE GOING FORECAST THIS MORNING. SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO LIFT NORTHEAST THROUGH WESTERN AND CENTRAL NORTH DAKOTA. A TIGHT PRESSURE GRADIENT WILL MOVE OVER CENTRAL NORTH DAKOTA THIS MORNING AS THE GRADIENT WEAKENS IN THE WEST WITH LOW PRESSURE MOVING INTO THIS AREA DURING THE MORNING. UPDATED LATEST SENSIBLE WEATHER GRIDS. UPDATED TEXT PRODUCTS WILL BE SENT SHORTLY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 444 AM CDT WED APR 23 2014 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CONTINUED GUSTY WINDS THIS MORNING AND AFTERNOON...PRECIPITATION CHANCES AND AMOUNTS TODAY AND TONIGHT...AND THUNDERSTORM CHANCES (NON- SEVERE) MOST LOCATIONS. CURRENTLY...UPPER LEVEL TROUGH EXTENDING FROM THE PACIFIC NORTHWEST SOUTHEAST INTO THE DESERT SOUTHWEST BECOMING NEGATIVELY TILTED AND SLOWLY MOVING EAST TOWARDS THE ROCKIES. POTENT EMBEDDED S/WV LIFTING NORTHEAST ACROSS WYOMING. SFC TROUGH CURRENTLY EXTENDS ACROSS THE HIGH PLAINS APPROACHING THE WESTERN DAKOTAS. MOISTURE TRANSPORT RABID THE PAST SEVERAL HOURS WITH A 60KT LOW LEVEL JET HELPING TO INCREASE PWATS FROM AROUND A QUARTER OF AN INCH LAST EVENING UP TO 0.75"-1.00" NOW. FORCING STRONG WITH STEEP THERMAL UPGLIDE EAST OF THE SFC TROUGH ALONG WITH INCREASING UPPER LEVEL DIVERGENCE AS A JET STREAK LIFTS NORTH-NORTHEAST FROM THE CENTRAL ROCKIES TOWARDS THE NORTHERN PLAINS. WIDESPREAD SHOWERS ACROSS THE SOUTHERN HALF OF ND LIFTING NORTH WITH CONTINUED DEVELOPMENT ACROSS NORTHERN SOUTH DAKOTA. EXPANDED SLIGHT CHANCE OF THUNDERSTORMS TO INCLUDE MUCH OF THE WEST AND CENTRAL THIS MORNING. HAVE ALREADY HAD SEVERAL LIGHTNING STRIKES SOUTHWEST WITH A FEW MORE JUST WEST OF WILLISTON OVER NORTHEAST MONTANA. MESOANALYSIS DEPICTS STEEP MID LEVEL LAPSE RATES (10C/KM) OVER THESE AREAS...WITH THE LATEST FEW RUNS OF THE RAP ALSO INDICATING 100-300 CAPE WEST. NEAR TERM HIGH RES MODELS SHOW THIS PLUME OF FAVORABLE MID LEVEL LAPSE RATES AND WEAK CAPE EXPANDING NORTH AND EAST WITH TIME THIS MORNING IN ADDITION TO CONTINUED STRONG FORCING. NOTHING SIGNIFICANT EXPECTED BUT WANTED TO MAKE SURE THUNDERSTORMS WERE IN THE FORECAST THROUGH THE AM. THE MAIN PRECIPITATION BAND IS STILL FORECAST TO LIFT NORTH AND EAST TODAY AS THE SURFACE TROUGH AXIS LIFTS NORTHEAST ACROSS THE STATE. MARGINAL CONVECTIVE PARAMETERS REMAIN OVER THE JAMES RIVER VALLEY THIS AFTERNOON/EARLY EVENING...SO WILL KEEP A MENTION OF SLIGHT CH. OF THUNDERSTORMS THERE...CONSISTENT WITH THE SPC DAY 2 OUTLOOK. PRECIPITATION CHANCES DECREASE OVERNIGHT 06-12Z AS ALL OF WEST AND CENTRAL ND BECOMES DRY SLOTTED. WILL ISSUE A WIND ADVISORY THIS MORNING THROUGH EARLY TO MID AFTERNOON ACROSS THE CENTRAL AND EAST WITH BUFKIT INDICATING 30 TO NEAR 35 KTS OF SUSTAINED WINDS AS THE MIXING HEIGHT ELEVATES AFTER DAYBREAK. OPTED TO START IT NOW AS HAVE ALREADY HAD GUSTS IN EXCESS OF 40 MPH ASSOCIATED WITH THE ONGOING SHOWERS AS THEY MIX SOME OF THE LLJ WINDS TO THE SURFACE. WINDS WILL TAPER OFF WEST TO EAST LATER THIS MORNING INTO THE AFTERNOON AS THE SFC TROUGH ADVANCES EAST. ON THE BACKSIDE OF THE TROUGH...WESTERLY WIND GUSTS TO 40 MPH ARE FORECAST ACROSS THE HIGHER TERRAIN OF THE SOUTHWEST TO DEVELOP THIS AFTERNOON...SO WENT WITH A WIND ADV. THERE AS WELL. FIRE DANGER WILL BE ELEVATED SOUTHWEST DUE TO THE STRONG WINDS AND DECREASING HUMIDITY. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 444 AM CDT WED APR 23 2014 A CLOSED UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN ON THURSDAY WILL MOVE EAST ALONG THE INTERNATIONAL BORDER THROUGH FRIDAY BRINGING SCATTERED SHOWERS TO MAINLY THE FAR NORTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. THE GFS IS THE FARTHEST SOUTH WITH THE TRACK OF THE UPPER LOW...THUS BRINGS THE CHANCE OF PRECIPITATION FARTHER SOUTH ON THURSDAY. USED A COMPROMISE HERE KEEPING THE FAR SOUTHWEST AND SOUTH CENTRAL DRY...AND A BAND OF SLIGHT CHANCE POPS FROM THE WEST CENTRAL INTO THE JAMES RIVER VALLEY...AND HIGHER CHANCE POPS ALONG THE NORTH. DUE TO THE PROXIMITY OF THE UPPER LOW...WILL KEEP A MENTION OF THUNDER ACROSS THE FAR NORTH THURSDAY AFTERNOON. ALSO KEPT A MENTION OF LINGERING RAIN/SNOW SHOWERS ACROSS THE FAR NORTH AND EAST THURSDAY NIGHT AND FRIDAY AS THE UPPER TROUGH LINGERS HERE THROUGH FRIDAY. INDICATIONS ARE THAT WE ARE IN FOR A WET PERIOD OVER THE WEEKEND AND INTO EARLY NEXT WEEK. DETERMINISTIC MODELS ARE IN BETTER AGREEMENT IN CLOSING OFF A STRONG UPPER LEVEL LOW OVER THE CENTRAL/SOUTHERN PLAINS. AN INITIAL WAVE LIFTS THROUGH THE AREA ON SATURDAY WITH THE BRUNT OF THE PRECIPITATION ARRIVING SUNDAY AND CONTINUING THROUGH MONDAY. ONE SIGNIFICANT DIFFERENCE BETWEEN THE GFS COMPARED TO THE ECMWF/GEM IS THE ORIENTATION OF THE DOWNSTREAM BLOCKING RIDGE. A GFS SOLUTION KEEPS A SHARPER RIDGE AHEAD OF THE LOW THUS SOUTHERLY FLOW REMAINS OVER THE AREA UNTIL LATE MONDAY. THEREFORE PRECIPITATION WOULD FALL AS ALL RAIN. A ECMWF /GEM SOLUTION DEPICTS A COLDER EAST TO NORTHEAST FLOW THROUGH THE ENTIRE EVENT. THUS A BETTER CHANCE OF MIXED RAIN AND SNOW OR ALL SNOW...ESPECIALLY DURING THE OVERNIGHT AND EARLY MORNING HOURS SUNDAY THROUGH MONDAY. WE DRY OUT TUESDAY AND WEDNESDAY BUT REMAIN COOL BEHIND THE EXITING LOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 104 PM CDT WED APR 23 2014 VFR/TEMPO MVFR CONDITIONS IN LIGHT RAIN SHOWERS WILL CONTINUE OVER WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON. GUSTY SOUTHEASTERLY WINDS WILL ALSO CONTINUE AHEAD OF A SURFACE FRONT. AS THE SURFACE FRONT PUSHES THROUGH WESTERN AND CENTRAL NORTH DAKOTA LATE THIS AFTERNOON/EARLY EVENING...PRECIPITATION CHANCES WILL DIMINISH AND WINDS WILL BECOME WESTERLY. VFR CONDITIONS ARE ALSO EXPECTED TO DEVELOP FROM WEST TO EAST TONIGHT THROUGH THURSDAY MORNING IN THE WAKE OF THE FRONT. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR NDZ001>003-010- 011-021-022-035-036-046-047-050. WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NDZ004- 005-012-013-023-025-037-040-041-043-044-048-051. && $$ UPDATE...TM SHORT TERM...NH LONG TERM...TWH AVIATION...TM
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
358 PM CDT WED APR 23 2014 .SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT COLD FRONT IS SLOWLY WORKING ITS WAY EAST ACROSS WESTERN SD AND IS APPROACHING THE WESTERN FRINGE OF THE CWA. AHEAD OF THE FRONT...STRONG SOUTHEAST WINDS CONTINUE...WELL INTO ADVISORY LEVELS FOR MANY LOCATIONS. ALTHOUGH...AS PRESSURE GRADIENT RELAXES A BIT WITH THE APPROACH OF THE SFC TROUGH...WE ARE SEEING A SUBTLE AND SLOW DROP OFF IN SPEEDS OUT OF CRITERIA LEVELS FROM WEST TO EAST. WILL LET THE JAMES VALLEY PORTION OF THE WIND ADVISORY EXPIRE AT 21Z WITH THE REMAINING EASTERN AREA GOING UNTIL 00Z. ASIDE FROM THE WIND...ALSO DEALING WITH SCT SHOWERS AHEAD OF THE FRONT. AS WAS SUGGESTED BY THE HRRR AND OTHER HI RES MODELS...WE ARE SEEING A BIT OF REDEVELOPMENT ALONG AND EAST OF THE MISSOURI RIVER. SO...EXPECTING DECENT CHANCES FOR PRECIP YET THIS AFTERNOON AND INTO THE EVENING HOURS BEFORE COLD FRONT SCOURS OUT MOST OF THE AVAILABLE MOISTURE. NEXT AREA OF CONCERN IS THE CRITICAL FIRE DANGER ON THURSDAY. BEHIND THE COLD FRONT...DRY AIR MOVES BACK INTO THE REGION ALONG WITH BREEZY NORTHWEST WINDS GUSTING OVER 30 MPH. MIN RH VALUES ARE EXPECTED TO FALL CLOSE TO 20 PERCENT IN THE JAMES VALLEY WITH VALUES LIKELY GOING BELOW 20 PERCENT ACROSS CENTRAL/SOUTH CENTRAL SD. HAVE THEREFORE UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG WARNING EFFECTIVE FROM 18Z TO 00Z TOMORROW. TEMPS STAY MILD THROUGH THE SHORT TERM...AND THERE HAS BEEN AN UPWARD TREND IN TEMPS ON FRIDAY. GFS IS STILL STUBBORN IN BRINGING COOLER TEMPS AT 850 MB INTO THE NORTHERN/EASTERN CWA DURING THE DAY FRIDAY...SHOWING A BIT MORE INFLUENCE OF THE COOLER HIGH TO THE NORTH. THIS REALLY IS NOT SUPPORTED BY OTHER MODELS THOUGH SO HAVE GONE WITH THE WARMER SOLUTIONS SEEN IN THE EC AND GEM. .LONG TERM...SATURDAY THROUGH WEDNESDAY THE MODELS SHOW GOOD AGREEMENT IN THE LONG TERM WITH A MAINLY WET AND COOL PATTERN FROM SATURDAY THROUGH MONDAY NIGHT. THE MODELS SHOW A SURFACE LOW PRESSURE AREA INTENSIFYING IN EASTERN COLORADO THROUGH SATURDAY AFTERNOON. THIS SURFACE LOW PRESSURE AREA THEN WOBBLES AND MOVES SLOWLY EAST AND SOUTHEAST ACROSS THE CENTRAL PLAINS THROUGH MONDAY NIGHT. DEEP AND MOIST EAST TO SOUTHEAST FLOW NORTH OF THE LOW PRESSURE AREA WILL BRING MAINLY RAIN TO MUCH OF OUR CWA STARTING SATURDAY AFTERNOON. THE CHANCES OF RAIN CONTINUE TO BE GOOD THROUGH MONDAY NIGHT. IT LOOKS LIKE MUCH OF THE CWA WILL GET SOME DECENT RAINFALL ACCUMULATIONS WITH THIS SYSTEM. OTHERWISE...THE SYSTEM WILL SLOWLY PUSH OUT FOR TUESDAY AND WEDNESDAY WITH COOL CANADIAN SURFACE HIGH PRESSURE BUILDING IN. WITH THE RAIN...CLOUDS AND CANADIAN AIR TEMPERATURES WILL BE MUCH BELOW NORMAL THROUGH THE ENTIRE LONG TERM. HIGHS WILL BE MOSTLY IN THE 40S AND 50S THROUGH THE PERIOD. && .AVIATION... 18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS MID AND UPPER LEVEL CLOUDS WILL CONTINUE TO STREAM OVER THE TAF LOCATIONS THROUGH THE AFTERNOON AND EVENING IN ADVANCE OF AN UPPER LEVEL LOW PRESSURE TROUGH MOVING IN FROM THE WEST. EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO CONTINUE TO DEVELOP ACROSS THE REGION INTO THE AFTERNOON AND EVENING. THESE MAY AFFECT THE TAF LOCATIONS AND WILL MONITOR FOR THAT POSSIBILITY. OTHERWISE...THE VERY STRONG SOUTHEAST WINDS WILL DECREASE INTO THE EVENING AT ALL LOCATIONS BEFORE BECOMING NORTHWEST. WITH INCREASING LOW LEVEL MOISTURE THROUGH THE DAY AND EVENING...EXPECT MVFR/LOW VFR CEILINGS TO FORM AT ABR AND ESPECIALLY ATY WITH SOME LIGHT FOG AT ATY. THE SKIES WILL GO MOSTLY CLEAR BEHIND THE FRONT AS THE WINDS COME AROUND TO THE NORTHWEST THIS EVENING THROUGH TONIGHT. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ TO 7 PM CDT /6 PM MDT/ THURSDAY FOR LOWER BAD RIVER-MISSOURI COTEAU-UPPER CHEYENNE- UPPER JAMES RIVER-UPPER MISSOURI COTEAU. WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLARK-CODINGTON- DAY-DEUEL-GRANT-HAMLIN-MARSHALL-ROBERTS. MN...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR BIG STONE-TRAVERSE. && $$ SHORT TERM...TMT LONG TERM...MOHR AVIATION...MOHR WEATHER.GOV/ABERDEEN