Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 03/25/12


AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
927 PM MDT SAT MAR 24 2012 .UPDATE... UPDATED FORECAST TO PUT OUT A DENSE FOG ADVISORY FOR KIOWA COUNTY...AND TO EXPAND AREAS OF FOG WESTWARD ACROSS CROWLEY AND OTERO COUNTIES. LATEST SFC OBS ALREADY SHOWING DEW POINTS IN THE UPPER 40S ADVECTING WESTWARD INTO SOUTHEAST CO. WITH FAIRLY STRONG EAST TO SOUTHEAST WINDS...EXPECT SOME LOWER 50 DEW POINTS TO MAKE IT INTO KIOWA AND PROWERS COUNTY TOWARDS MORNING. LATEST HRRR LOOKS A BIT OVERLY AGGRESSIVE BRINGING LOW LEVEL MOISTURE BACK AS FAR WESTWARD AS EL PASO AND PUEBLO COUNTIES...AND HAVE GONE WITH A COMPROMISE BETWEEN THE HRRR AND DRIER NAM12 FOR THESE AREAS. HOWEVER...APPEARS KIOWA COUNTY MAY HAVE THE BEST SHOT OF SEEING SOME DENSE FOG FORMATION...THUS PER COORD WITH SURROUNDING OFFICES...HAVE PUT OUT A DENSE FOG ADVISORY FOR THIS AREA. LATER SHIFTS WILL NEED TO MONITOR PROWERS COUNTY AS WELL...BUT MODEL SOUNDINGS ARE NOT AS IMPRESSIVE WITH LOW LEVEL MOISTURE ACROSS THIS ZONE...WITH RUC13 KEEPING RICHER MOISTURE FARTHER EAST AND NORTH. SO WILL LEAVE THIS ZONE OUT FOR NOW AND CONTINUE TO MONITOR. -KT && .PREV DISCUSSION... /ISSUED 308 PM MDT SAT MAR 24 2012/ SHORT TERM... (TONIGHT AND SUNDAY) AN UPPER LEVEL RIDGE IS FORECAST TO SHIFT EAST INTO THE CENTRAL PLAINS TONIGHT WITH INCREASING SOUTHWESTERLY FLOW EXPECTED ON SUNDAY. CURRENTLY A WEAK SURFACE BOUNDARY HAS BEEN TRACKING SOUTH ACROSS THE PLAINS. THE MAIN INFLUENCE OF THIS FRONT IS A NORTHERLY WIND SHIFT AND A FEW BRIEF GUSTS OF WIND. TEMPERATURES HAVE EXCEEDED OR TIED RECORDS AT COLORADO SPRINGS AND PUEBLO SO FAR THIS AFTERNOON. TONIGHT AND TOMORROW...GIVEN CLEAR SKIES AND DIMINISHING WINDS WILL LEAD TO OVERNIGHT LOWS IN THE 40S ACROSS SOUTHERN COLORADO. MODELS TRYING TO DEVELOP FOG OUT ALONG THE KANSAS BORDER WHERE WEAK SOUTHEASTERLY UPSLOPE FLOW AND DEEPER MOISTURE RESIDE. THINK AREAS UP THE ARKANSAS RIVER VALLEY NEAR THE KANSAS BORDER STAND THE BEST CHANCE AT SEEING FOG FOR TONIGHT. SOUTHWESTERLY FLOW INCREASES TOMORROW WITH THE MAIN CONCERN BEING THE NEAR RED FLAG CONDITIONS FOR PORTIONS OF THE PLAINS. HUMIDITIES WILL BE LOW GIVEN THE DOWNSLOPE SOUTHWESTERLIES AND DRY AIR MIXING DOWN. WINDS LOOK MARGINAL...WITH A FEW AREAS SEEING GUSTS 20 TO 25 KTS DURING THE AFTERNOON. CAUTION IS ADVISED...ESPECIALLY SOUTH OF HIGHWAY 50 AND ALONG THE KANSAS BORDER. OTHERWISE EXPECT WARM TEMPERATURES WITH RECORD HIGHS ONCE AGAIN FOR SOUTHEAST COLORADO. ALSO OF NOTE...MODELS HINTING AT AN ISOLATED THUNDERSTORM OVER THE SOUTHERN SAN JUAN AND SANGRE DE CRISTO RANGES...BUT CURRENTLY THINK THIS WILL ONLY AMOUNT TO CUMULUS BUILD UPS IN THE AFTERNOON GIVEN LACK OF MOISTURE. 88 LONG TERM... (SUNDAY THROUGH FRIDAY) ..CRITICAL FIRE WEATHER CONDITIONS EXPECTED ON MONDAY... MAIN CONCERN THIS FCST PD IS FIRE WX CONCERNS ON MONDAY. AS HAS BEEN FCSTD BY THE SIMULATIONS FOR DAYS...IT WILL LIKELY BE VERY WINDY WITH LOW HUMIDITY VALUES OVER THE REGION ON MONDAY. WIDESPREAD WINDS OF 30 TO 45 MPH WILL OCCUR BY AFTERNOON ACROSS THE ENTIRE REGION AS A VIGOROUS SHORT WAVE MOVES TO OUR NORTH DURING PRIME HEATING. LAPSE RATED OF 8.5 TO 9.5C/KM AND 50 KNOT 700 MB WINDS WILL ALLOW FOR VERY GUST WINDS. WITH THE STRONG WINDS...BLOWING DUST WILL BE AN ISSUE ONCE AGAIN DUE TO THE SUSTAINED DROUGHT CONDITIONS. ALTHOUGH BACA COUNTY RECEIVED ALMOST AN INCH OF RAIN THE OTHER DAY...I AM CONFIDENT THAT THIS AREA WILL DRY OUT SIGNIFICANTLY (1 HOUR FUELS...I.E., GRASSES) BY THE TIME MONDAY ROLLS AROUND. THE DRYLINE WILL LIKELY MIX OUT INTO KS RELATIVELY EARLY IN THE DAY...SO I DO NOT ANTICIPATE ANY CONVECTION ALONG THE BORDER ATTM. IN THE MTNS...SHORT WAVE MAY BE CLOSE ENOUGH ALONG WITH STRONG LIFT TO ALLOW FOR SOME SHOWERS ALONG THE CONTDVD...MAINLY OVER THE C MTNS. ONCE THIS TROUGH GOES BY...GENERAL WEAK WSW FLOW ALOFT WILL BE OVER THE REGION THROUGH LATE WEEK. WX DURING THIS PD WILL BE SEASONAL WITH ABOVE NORMAL TEMPS. A WEAK TROUGH AT MID LVLS WILL MOVE ACROSS THE REGION ON FRIDAY. NO SENSIBLE WX WILL LIKELY OCCUR WITH IT. TEMPS WILL COOL A COUPLE OF DEGREES AS COMPARED TO THURSDAY. WE WILL LIKELY NOT SEE ANY PRECIP AT KCOS...KPUB OR KALS THROUGH THE END OF THE MONTH. TO DATE...AT KPUB WE HAVE RECEIVED 0.11 INCHES...OUR NORMAL IS 0.93. AT KCOS...WE HAVE RECEIVED 0.06...THE NORMAL IS 1.00 INCHES. AT KALS WE RECEIVED 0.10...NORMAL IS 0.53. WITHOUT SAYING...WE NEED PRECIP. /34 AVIATION... VFR CONDITIONS AT ALL TERMINALS THROUGH THE NEXT 24 HOURS. 88 && .PUB WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR COZ221-222-226>237. DENSE FOG ADVISORY FROM 2 AM TO 8 AM MDT SUNDAY FOR COZ095-096. && $$ 31/44
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1121 PM EDT SAT MAR 24 2012 .SYNOPSIS... SLOW MOVING LOW PRESSURE OVER THE SOUTHERN MID ATLANTIC REGION WILL PASS TO THE SOUTH SUNDAY NIGHT...THEN HEAD NORTHEAST OUT TO SEA AND STRENGTHEN AFTER A COLD FRONT MOVES THROUGH MONDAY MORNING. HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH MONDAY AFTERNOON THROUGH TUESDAY...AND THEN SLIDE EAST TUESDAY NIGHT. LOW PRESSURE AND AN ASSOCIATED FRONTAL SYSTEM WILL MOVE ACROSS FROM WEDNESDAY INTO EARLY THURSDAY...FOLLOWED BY HIGH PRESSURE LATER THURSDAY INTO FRIDAY. A WARM FRONT WILL APPROACH LATE FRIDAY NIGHT INTO SATURDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... RAIN ASSOCIATED WITH THE LOW TO OUR SW IS FINALLY OVERCOMING LOW LEVEL DRY AIR IN THE NYC METRO AREA...SO HAVE ADJUSTED OVERNIGHT POP ACCORDINGLY...WITH ALL AREAS EVENTUALLY GETTING SOME SHOWERS OVERNIGHT. BACK EDGE OF THESE SHOWERS MOVING SLOWLY N FROM SOUTHERN NJ SHOULD REACH THE NYC METRO AREA IN THE PREDAWN HOURS. THE INCOMING 00Z NAM APPEARS TO AGREE WITH THIS ENDING TIME...THOUGH THE 00Z HRRR HINTS THAT ADDITIONAL SHOWERS COULD FILL IN TO THE SW AND SPREAD INTO THE AREA INTO THE EARLY DAYLIGHT HOURS. SOME ELEVATED INSTABILITY PRESENT BUT AT LEVELS TOO LOW TO PRODUCE THUNDER. EARLIER MAV/MET MOS BLEND LOOKED GOOD FOR LOWS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/... LOW PRESSURE CENTER EMERGES OFF THE MID ATLANTIC COAST AND CONTINUES TO HEAD EAST DURING THE DAY ON SUNDAY. WITH THE ISENTROPIC LIFT EXITING THE EASTERN ZONES IN THE MORNING...THE ONLY OTHER SOURCES OF LIFT WILL BE A WEAK MID LEVEL SHORTWAVE ENTERING DURING THE AFTERNOON HOURS...WITH PERHAPS A LITTLE BIT OF ADDITIONAL SYNOPTIC LIFT SUPPLIED BY AN UPPER JET STREAK. POPS THEREFORE NO HIGHER THAN THE CHANCE CATEGORY ONCE THE MAIN BATCH OF RAIN EXITS TO THE EAST IN THE MORNING. THE AFTERNOON COULD VERY WELL END UP COMPLETELY DRY FOR MOST SPOTS. LEANED A LITTLE MORE TOWARDS THE COOLER NAM MOS FOR HIGHS...BUT THIS STILL YIELDS HIGHS WARMER THAN NORMAL. THE LOW BEGINS TO HEAD NORTHEAST SUNDAY NIGHT...BUT ONLY A SLIGHT CHANCE OF A SHOWER FOR US EARLY IN THE EVENING...ASSOCIATED WITH THE SHORTWAVE. DRY THEN FOR THE REST OF SUNDAY NIGHT. ON MONDAY...WITH THE STORM CENTER HEADING NE FARTHER OUT TO SEA...A COLD FRONT DROPS DOWN FROM THE NORTH EARLY ON. WITH LIMITED MOISTURE DURING ITS PASSAGE...WILL GO WITH A DRY FORECAST. A STRONG MID LEVEL SHORTWAVE FOLLOWS LATE IN THE DAY INTO THE EVENING HOURS...BUT AGAIN NO RAINFALL EXPECTED WITH IT...JUST SOME CU BUILDUP AT BEST. THE PRESSURE GRADIENT WILL TIGHTEN THROUGH THE DAY AS HIGH PRESSURE BUILDS IN FROM THE NORTH...THIS COMBINED WITH STRONG COLD AIR ADVECTION WILL BRING US A BREEZY DAY WITH GUSTY WINDS. HIGH TEMPERATURE FORECAST FOR MONDAY WILL BE A LITTLE TRICKY WITH THE COLD AIR ADVECTION INCREASING AS THE DAY WEARS ON. BUT AT THE SAME TIME...STRONG DOWNSLOPING COULD OFFSET THIS A LITTLE. IT MIGHT NOT BE THE TYPICAL DIURNAL HEATING PATTERN...AND HIGHS COULD BE ACHIEVED NEAR NOONTIME INSTEAD OF MID-LATE AFTERNOON. TOOK A BLEND OF THE NAM/MAV MOS FOR HIGHS...WHICH ENDS UP A LITTLE ABOVE NORMAL FOR THIS TIME OF THE YEAR. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... A DEEP UPPER TROUGH WILL MOVE TO THE EAST MON NIGHT INTO EARLY TUE MORNING...WITH THE AREA CAUGHT BETWEEN INTENSIFYING LOW PRESSURE SE OF NOVA SCOTIA...AND A STRONG HIGH BUILDING S FROM HUDSON BAY. THE TIGHT PRESSURE GRADIENT BETWEEN THE TWO WILL PRODUCE COLD AND BRISK CONDITIONS MON NIGHT INTO EARLY TUE AFTERNOON. SIDED WITH WARMER MAV MOS GUIDANCE VS NAM FOR LOWS MON NIGHT...BUT EVEN SO MON NIGHT WILL BE QUITE COLD...WITH LOWS ABOVE FREEZING ONLY IN NYC...BELOW 30 OUTSIDE THE NYC METRO AREA...AND POSSIBLY CLOSING IN ON 20 IN SOME OF THE INTERIOR VALLEYS...ESPECIALLY IF WINDS DROP OFF VERY LATE AT NIGHT. WIND CHILLS ACROSS THE INTERIOR WILL ALSO DROP INTO THE TEENS LATE MON NIGHT. DESPITE THE COLD OF MON NIGHT...RISING HEIGHTS ALOFT SHOULD ACTUALLY HELP KEEP HIGHS NEAR AVG ON TUE. FULL MIXING OF 875 MB TEMPS NEAR -2C PLUS DOWNSLOPE FLOW WILL RESULT IN HIGHS IN THE LOWER 50S IN NYC AND COASTAL SECTIONS...AND UPPER 40S INLAND. MORE ROBUST WAA SHOULD TAKE PLACE TUE NIGHT-WED IN RETURN S-SW FLOW AS THE HIGH SLIDES TO THE E-SE AND A WARM FRONT APPROACHES...WITH HIGHS REBOUNDING TO THE UPPER 50S/LOWER 60S. EXPECT A CHANCE OF SHOWERS MAINLY WED AFTERNOON/NIGHT AS THIS FRONT MOVES THROUGH AND A COLD FRONT TRAILING FROM LOW PRESSURE PASSING TO THE NORTH APPROACHES...THEN ONLY SLIGHTLY COOLER BUT STILL ABOVE AVG TEMPS ON THU/FRI AS ANOTHER HIGH BUILDS IN...WITH 50S TO NEAR 60. AFTER THIS HIGH MOVES EAST... ANOTHER WARM FRONT WILL APPROACH LATE FRI NIGHT INTO SAT WITH ANOTHER CHANCE OF SHOWERS. NOTE FOR AGRICULTURAL CONCERNS...TEMPS WILL FALL TO AT OR JUST BELOW FREEZING JUST OUTSIDE OF NYC...AND INTO THE 20S OVER THE LOWER HUDSON VALLEY...INTERIOR NE NJ...SOUTHERN CT...AND CENTRAL/EASTERN LONG ISLAND. SUB-FREEZING TEMPS ARE ALSO POSSIBLE TUE NIGHT OUTSIDE OF URBAN CENTERS IF RADIATIONAL COOLING CONDITIONS ARE RIGHT. WINDS WILL BE LIGHT BUT SOME MID LEVEL CLOUDS PASSING THROUGH MAY MITIGATE THIS SOMEWHAT. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... A WARM FRONT WILL REMAIN TO THE SOUTH...WHILE LOW PRESSURE MOVES SLOWLY ACROSS THE SOUTHERN MID ATLANTIC REGION. SPOTTY LIGHT RAIN AND MVFR CIGS ARE ABOUT TO MOVE INTO THE NYC METRO AREA...AND SHOULD SPREAD INTO AREAS FARTHER NORTH/EAST AFTER MIDNIGHT. EXPECT PRIMARILY MVFR CONDITIONS...BUT CANNOT TOTALLY RULE OUT TEMPO IFR CIGS NEAR OR JUST AFTER DAYBREAK... FROM ABOUT 09Z-13Z. WITH WEAK E-NE FLOW AND LOW MOISTURE WILL NOT GOING ANYWHERE FAST AFTER DAYBREAK...SO MVFR CONDITIONS SHOULD LAST INTO EARLY AFTERNOON...WITH SLOW IMPROVEMENT TO VFR BY MID TO LATE AFTERNOON EXCEPT AT KGON. OUTLOOK FOR 00Z MON THROUGH THU... .SUNDAY NIGHT...LINGERING MOISTURE AND LIGHT WINDS COULD LEAD TO LOW CLOUDS AND/OR FOG WITH SUB-VFR CONDITIONS LATE...ESPECIALLY AT KHPN/KISP/KBDR/KGON. .MON-TUE...VFR. COLD FROPA MON MORNING...FOLLOWED BY GUSTY NW-N FLOW. DIMINISHING WINDS TUE AFTERNOON. .WED...MVFR CONDITIONS ARE POSSIBLE IN THE AFTERNOON AND AT NIGHT AS LOW PRESSURE AND A WARM FRONT APPROACH. GUSTY SW FLOW IN THE AFTERNOON. .THU...VFR. GUSTY NW FLOW. && .MARINE... E FLOW AROUND 15 KT WILL PERSIST TONIGHT...AND OCEAN SEAS MAY COME VERY CLOSE TO REACHING 5 FT. ANY GUSTS TO 25 KT AT THE SAME TIME WOULD BE OCCASIONAL. HAVE THEREFORE HELD OFF ON ISSUING SCA. WAVEWATCH APPEARS TO BE TO HIGH GIVEN THE WIND FORECAST AND LACK OF A SIGNIFICANT SWELL LATE TONIGHT INTO SUNDAY NIGHT...AND HAVE KEPT SEAS BELOW 5 FT. WINDS WILL AT LEAST DIMINISH DURING SUNDAY AND SUNDAY EVENING. FOR MON/MON NIGHT...AT LEAST AN SCA WILL LIKELY BE NEEDED BY AFTERNOON...AND POSSIBLY A GALE WARNING ESPECIALLY ON THE OCEAN. WINDS WILL STRENGTHEN AFTER A COLD FRONTAL PASSAGE MON MORNING...WITH A TIGHTENING PRESSURE GRADIENT AND STRONG COLD AIR ADVECTION MOVING IN. WILL CONTINUE TO MENTION THE THREAT OF GALES IN THE HWO. CONDS SHOULD GRADUALLY FALL THROUGH SCA AND THEN BELOW ON TUE. SCA CONDS POSSIBLE ONCE AGAIN ON THE OCEAN WATERS WED AFTERNOON/NIGHT IN STRENGTHENING S-SW FLOW AHEAD OF A COLD FRONT... AND AGAIN THE AFTERNOON/EVENING IN POST-FRONTAL NW FLOW. && .HYDROLOGY... RELATIVELY DRY CONDITIONS WILL CONTINUE...WITH NO SIGNIFICANT QPF OF 1/2 INCH OR MORE EXPECTED FOR THE NEXT 7 DAYS. IN FACT...THE U.S. DROUGHT MONITOR CATEGORIZES SE CT AS BEING IN MODERATE DROUGHT...AND THE REST OF THE REGION AS ABNORMALLY DRY. && .TIDES/COASTAL FLOODING... A PERSISTENT EAST TO NORTHEAST FLOW WILL EXIST TONIGHT INTO SUNDAY MORNING AS MID ATLANTIC LOW PRESSURE TRACKS SOUTH AND THEN EAST OF THE AREA. THERE IS ONLY A LOW POTENTIAL AT BEST FOR MINOR COASTAL FLOODING...AS 1 1/2 TO 2 FT POSITIVE DEPARTURES ARE NEEDED TO REACH THESE THRESHOLDS. BASED ON CURRENT DEPARTURES AND LATEST MODEL GUIDANCE...FLOODING IS NOT EXPECTED TONIGHT OR SUNDAY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...JC NEAR TERM...JC/GOODMAN SHORT TERM...JC LONG TERM...GOODMAN AVIATION...GOODMAN MARINE...JC/GOODMAN HYDROLOGY...JC/GOODMAN TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
936 PM EDT SAT MAR 24 2012 .SYNOPSIS... LOW PRESSURE WILL TRACK SOUTH OF US AND MOVE OFF THE COAST SUNDAY EVENING. A COLD FRONT WILL MOVE THROUGH THE AREA DURING THE DAY ON MONDAY. HIGH PRESSURE WILL THEN ARRIVE FOR TUESDAY AND PERSIST THROUGH EARLY WEDNESDAY. A WARM FRONT IS FORECAST TO LIFT NORTHEASTWARD TOWARD THE REGION LATE ON WEDNESDAY. ANOTHER COLD FRONT, MOVING IN FROM THE WEST, SHOULD WORK ITS WAY THROUGH THE AREA ON WEDNESDAY NIGHT. MORE HIGH PRESSURE IS FORECAST FOR THURSDAY, FRIDAY, AND POSSIBLY SATURDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... THE UPPER LOW ACROSS THE OHIO VALLEY WILL MOVE EWRD TONIGHT INTO THE CAROLINAS. A SFC LOW WILL MOVE A LITTLE AHEAD OF THE UPPER LOW AND CAUSE A FRONTAL SYSTEM TO APPROACH THE AREA TONIGHT. THE REGIONAL RADARS ARE SHOWING SHOWERS APPROACHING FROM THE SW ATTM. THESE SHOWERS WILL BE ACROSS THE AREA EARLY TONIGHT ALONG WITH AREAS OF FOG WHICH SHOULD DEVELOP TOO. THE FOG WILL PROBABLY BE MORE ABUNDANT NEAR THE SHORE...BUT WAS INCLUDED IN ALL AREAS WITH THIS FCST. RAINFALL TOTALS WILL BE AROUND A TENTH TO ONE QUARTER INCH. LOW TEMPERATURES WILL RANGE FROM THE LOW OR MID 50S ACROSS THE DELMARVA TO THE LOW/MID 40S ACROSS THE NRN AREAS. WINDS WILL BE ERLY AT 5 TO 10 MPH. BASED ON LATEST RADAR TRENDS, HAVE LOWERED POPS FOR NEXT FEW HOURS. HRRR DATA INDICATES AN INCREASE IN PRECIP AGAIN AFTER 02 OR 03Z, SO DIDN`T WANT TO CHANGE TOO MUCH, BUT LATEST RADAR DOESN`T HAVE THAT MUCH BEHIND ONES BAND OF SHOWERS IN SRN NJ. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... SLOW IMPROVEMENT IN THE WEATHER FOR SUNDAY. THE LOW PRESSURE SYSTEM WILL BE OFFSHORE AND MOVING TO THE NORTHEAST. IT WILL SLOWLY STRENGTHEN AND BRING MORE OF A NERLY THEN NRLY WINDS ACROSS THE AREA. WHILE CLOUDS ARE EXPECTED MUCH OF THE DAY...A GRADUAL IMPROVEMENT SHOULD OCCUR LATE. A FEW LINGERING SHOWERS ARE POSSIBLE SOUTH AND EAST MOSTLY DURING THE MORNING. HIGHS ON SUN WILL BE SOMEWHAT DEPENDENT ON HOW MUCH SUN BREAK OUT LATE IN THE DAY...I HAVE GONE MOSTLY MID TO UPPER 60S ATTM WITH UPPER 50S ACROSS THE SRN POCONOS...THIS IS A FEW DEGREES LOWER THAN WHAT THE GUIDANCE TEMPS HAVE. WINDS WILL BE MOSTLY LIGHT ON SUNDAY...MOSTLY NE OR N AT 5 TO 10 MPH. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... THE MID-LEVEL LOW AXIS IS FORECAST TO SHIFT OFF THE COAST SUNDAY NIGHT BRINGING AN END TO THE SHOWER THREAT. WHILE A DRY COLD FRONT ON MONDAY WON`T BRING ANY RAIN TO THE REGION, IT WILL PROVIDE A CHANGE IN AIRMASS. WITH IT`S STRONG CAA AND GUSTY WINDS, MARCH 26TH WILL ACTUALLY FEEL LIKE MARCH 26TH, NOT APRIL OR MAY 26TH. A SURFACE HIGH, CENTERED ACROSS ONTARIO, MONDAY NIGHT WILL BEGIN TO SAG INTO THE REGION BRINGING WITH IT A LITTLE LESS GRADIENT. THE HIGH WILL BE ON TOP OF US ON TUESDAY AND WILL MOVE TO THE COAST ON TUESDAY NIGHT. LOOKS LIKE A WARM FRONT IS GOING TO APPROACH US FROM THE SOUTH ON WEDNESDAY, BUT STRUGGLE TO MOVE THROUGH. WHAT`S MORE CERTAIN IS THE COLD FRONT, COMING IN FROM THE WEST, THAT WILL CROSS THE REGION ON WEDNESDAY NIGHT. HIGH PRESSURE IS FORECAST TO BUILD IN BEHIND THIS FRONT AND PERSIST INTO FRIDAY AND MAYBE EVEN SATURDAY. NO HEAVY PRECIPITATION IS EXPECTED THROUGH THIS PERIOD. SHOWERS WILL BE CARRIED SUNDAY NIGHT, AT LEAST EARLY, AND AGAIN ON WEDNESDAY INTO THURSDAY WITH THE MIDWEEK COLD FRONT. AS FOR TEMPERATURES, NOT MUCH CHANGE FROM YESTERDAY. WE`LL SEE MORE CHANGEABLE CONDITIONS, SYNONYMOUS OF SPRING. MONDAY SHOULD BE ABOVE NORMAL (ALTHOUGH THE NAM MOS SAYS OTHERWISE), TUESDAY AROUND NORMAL, WEDNESDAY/THURSDAY ABOVE NORMAL, AND BACK TO NEAR NORMAL FRIDAY/SATURDAY. THE REGION WILL SEE SOME 30S NEXT WEEK IN THE MORNING. THE COLDEST MORNING STILL LOOKS TO BE TUESDAY WHERE WE SHOULD SEE SUB-FREEZING TEMPERATURES. NOT A GOOD THING FOR SENSITIVE VEGETATION/TREES THAT HAVE GOTTEN OFF TO A TWO TO FOUR WEEK HEAD START THANKS TO WHAT COULD AMOUNT TO A TOP 3 MARCH TEMP-WISE. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... CONDITIONS WERE MAINLY VFR AND MVFR ERLY THIS EVENING. LATEST GUIDANCE CONTINUED TO INDICATE DETERIORATION WILL BEGIN LATER THIS EVENING AS ANOTHER AREA OF SHOWERS AND DEEPER MOISTURE ARRIVE...WITH FLYING CONDITIONS EXPECTED TO GO IFR IN MOST AREAS AFTER MIDNIGHT. ONLY SLOW IMPROVEMENT WILL OCCUR SUNDAY MORNING...SINCE THE SFC/UPPER LOW MOVING ACROSS THE AREA WILL NOT BE MOVING THAT FAST. BETTER CONDITIONS WILL ARRIVE LATER SUNDAY...ONCE THE SYSTEM MOVES AWAY AND SFC WINDS TURN MORE TOWARD THE N OR NW. OUTLOOK... SUNDAY NIGHT...VFR. MONDAY...VFR WITH A GUSTY NORTHWEST WIND. MONDAY NIGHT THROUGH TUESDAY NIGHT...VFR. WEDNESDAY...MAINLY VFR. BUT A CHANCE OF SHOWERS WITH THE COLD FRONT. THURSDAY...MAINLY VFR WITH SOME REMNANT POST FRONT SHOWERS POSSIBLE. && .MARINE... EAST WINDS HAVE REMAINED AROUND 10 TO 15 KTS ON THE WATERS TODAY...THE DEVELOPING SFC LOW TO THE SOUTH SHOULD KEEP WINDS MOSTLY ERLY TONIGHT. A SCA FLAG WILL PROBABLY NOT BE NEEDED TONIGHT...BUT SEAS MAY GET CLOSE TO 5 FT...WE MAY HAVE TO ISSUE SCA IF THE SEAS GET OVER 5 FT. LOW CONFID IN THIS ATTM. WINDS WILL SLACKEN SUN MORNING AS THE SFC PRESSURE TROUGH CROSSES THE WATERS. WINDS WILL SLOWLY VEER NERLY THEN NRLY ON SUNDAY. AREAS OF SHOWERS AND FOG WILL BE ON THE WATERS TONIGHT AND SUN MORNING. OUTLOOK... A STRONG COLD FRONT, FROM THE NORTHWEST, IS EXPECTED TO CROSS THE COASTAL WATERS OF NEW JERSEY AND DELAWARE ON MONDAY. HIGH PRESSURE WILL FOLLOW AND PERSIST THROUGH LATE TUESDAY. A WARM FRONT IS ANTICIPATED TO APPROACH FROM THE SOUTHWEST ON WEDNESDAY FOLLOWED BY A COLD FRONT ON WEDNESDAY NIGHT. A SMALL CRAFT ADVISORY MAY BE NEEDED FROM MONDAY INTO TUESDAY MORNING FOR THE GUSTY NORTHWEST WINDS IN THE COLD ADVECTION. ISOLATED GALE FORCE GUSTS MAY OCCUR FROM LATE MONDAY INTO MONDAY NIGHT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...KRUZDLO NEAR TERM...NIERENBERG/O`HARA SHORT TERM...O`HARA LONG TERM...KRUZDLO AVIATION...KRUZDLO/NIERENBERG/O`HARA MARINE...KRUZDLO/O`HARA
AREA FORECAST DISCUSSION...UPDATED
NWS TALLAHASSEE FL
1014 PM EDT Sat Mar 24 2012 .NEAR TERM (TONIGHT)... The severe threat discussed in the previous AFD has diminished. A few showers are popping up behind the frontal line from central Mitchell to the Worth-Colquitt county border and into Tift. However these showers aren`t in a region of as much instability as the storms near Valdosta earlier this evening. Even when they interacted with the outflow boundary from the earlier storms, they aren`t developing further. Modified 02Z RUC VLD soundings lifted from 76/66 have a CAPE of only about 1000 J/kg...500 J/kg less than the smallest estimated CAPE for 01Z. Lows tonight will be in the mid 50s for most of the forecast area, upper 50s along the coast. && .MARINE (TONIGHT THROUGH THURSDAY)... A surge of 15-kt winds along the northeastern GOMEX coast will cause some 4 ft waves overnight. A very week pressure gradient for Monday into Tuesday will keep winds and seas minimal. Easterly flow will increase by mid-week as high pressure builds along the eastern seaboard. && .AVIATION (THROUGH 00Z MONDAY)... Isolated showers will remain possible in the vicinity of residual outflow boundaries from earlier convection. These should stay away from the VLD and ABY terminals and dissipate by ABOUT 04Z. Winds will shift to the northwest behind a cold front with clear skies forecast for Sunday. Winds will occasionally gust to 20 kt after 14Z with sustained winds running 10-13 knots. && .FIRE WEATHER...Drier air will be spreading across the Tri-State Area tonight and Sunday, on the heels of a cold front that has pushed south and east of the area. Relative humidities are forecast to fall to critical levels across all but the immediate coastal areas of the eastern Florida Panhandle and Big Bend on Sunday afternoon. In addition, dispersion indices across the Florida zones are expected to exceed 75, and a Red Flag Warning has been issued for all but the coastal zones. On Monday and Tuesday, relative humidities are expected to approach or briefly drop below red flag criteria. However...durations are not expected to be met. && .PREV DISCUSSION (628 PM EDT Sat Mar 24 2012)... SHORT TERM (Tonight through Monday night)...Cold front associated with the deep upper low will finally exit the forecast area this evening. Showers and thunderstorms will likely linger into the mid-evening hours over the eastern big bend before ending by midnight. With the latest VWP data showing winds veering substantially at KVLD, severe threat should be rather low. A drier airmass will arrive in the wake of the front. This will allow overnight lows to fall back into the lower to mid 50s for the next few nights. However, highs will continue to reach the lower to mid 80s each afternoon. After this evening, no rain is expected through Monday night. LONG TERM (Tuesday through next Saturday)...There is good consensus between the models that the long term period will remain rather calm, with a benign weather pattern in place. The northern stream flow will remain across the northern half of the country through the period, with a chain of shortwaves forecast to pass through it. Across the southern part of the country, a mix of ridging and a zonal flow regime will dominate. As each of the aforementioned shortwaves pass well north of the local area, they will have little effect on the local weather, with the exception of dampening any ridging that is occurring over the southeastern part of the country. The result of this pattern will be dry and warm afternoons, with mild evenings. Temperatures are forecast to climb into the lower to middle 80s each afternoon, with low temperatures bottoming out in the middle to upper 50s. No mentionable rain chances exist through the period. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 54 81 52 84 53 / 10 0 0 0 0 Panama City 59 79 60 79 61 / 10 0 0 0 0 Dothan 54 80 55 84 56 / 0 0 0 0 0 Albany 53 79 53 82 55 / 10 0 0 0 0 Valdosta 54 79 53 82 54 / 20 0 0 0 0 Cross City 58 81 52 83 53 / 50 10 0 0 0 Apalachicola 59 76 57 77 60 / 10 0 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...None. GA...None. FL...Red Flag Warning from 2 PM EDT /1 PM CDT/ to 7 PM EDT /6 PM CDT/ Sunday for Calhoun-Central Walton-Gadsden-Holmes-Inland Bay- Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson- Inland Taylor-Inland Wakulla-Inland Walton-Jackson- Lafayette-Leon-Liberty-Madison-Washington. GM...None. && $$ Aviation...Wool Marine...Camp Fire Weather...Duval Previous Discussions...Camp/Harrigan Rest of Discussion...Moore
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
340 PM EDT Fri Mar 23 2012 .SYNOPSIS... 19Z water vapor and H4 RUC analysis shows northern stream upper level flow arriving over the northern California/Oregon coast before ridging well to the north over south-central Canada. Main feature of note to the south of this flow is the large and stubborn upper level low spinning over the middle of the country. Upper level ridge that had been in control of our region is begin de-amplified and pushed to the east as the previously mentioned upper low begins to migration toward the eastern seaboard. At the surface, forecast are resides between a large area of high pressure off the SE coast, and a weak cold front currently extending from the western TN valley to the north-central Gulf of Mexico. Deep southerly flow is begin experienced between these two features into our zones providing abundant low level moisture. WAA, a slow increase in synoptic support, and surface focus ahead of the front are supporting a band of showers and thunderstorms from the open waters south of Mobile northward to the FL panhandle/eastern AL/western GA. A few of these storms have shown a tendency to rotate over the past few hours, and will need to monitored closely. && .SHORT TERM (Tonight through Sunday Night)... Tonight, Upper level low will slowly drift eastward with the main cool pool influence remaining to our north. Several guidance members show a rapid decrease in convective coverage this evening as the band of frontal showers/storms continues it painfully slow eastward trek. Difficult to determine why this decrease is being advertised...and also having a hard time believing this forecast philosophy due to the continued deep convection and extensive area of regenerating cold cloud tops off the MS delta late this afternoon. Would not be surprised to some decrease in the strength of convection after the loss of diurnal heating, but will be keeping chance PoPs for showers and storms in the grids. Saturday, Late tonight as we approach dawn, the upper low begins to pivot back Southward and we see slightly better height falls/QG forcing overspreading the NE gulf. Global guidance and several CAM members show a resurgence of convection beginning at this time and continuing into Saturday morning ahead of the front. This seems reasonable and will show likely rain chances around 60% along and east of a line roughly from Panama City to Albany. Still expecting a scattering of showers to the west of this line during the morning hours, however with the passage of the surface front by early afternoon will see drier air and falling rain chances for these western zones. This will be at least a marginal threat for some strong to severe thunderstorms over mainly the eastern half of the region during the daylight hours of Saturday. Currently the most favorable kinematics/thermodynamics appear to align a bit to our NE tomorrow, however with 30-40kts of deep layer shear present, the potential for organized updraft will exist, especially if we experience enough sunny breaks to add to the instability. Will continue to monitor this situation, and a more detailed briefing packet on the threat is available at http://www.srh.noaa.gov/images/tae/briefing/EMBriefingMarch232012.pdf . Saturday Night, Upper level low begins to make more progressive progress. Energy rounding the base of the low now looks to give the final push to accelerate the surface front south and eastward out of our region. Therefore will see the last of the showers/storms over the SE Big Bend zones ending during the pre-dawn hours. The arrival of a drier airmass will allow temps to drop into the 50s by sunrise. Sunday/Sunday Night, A pleasant and dry day on tap for the second half of the upcoming weekend. Deep layer NW flow will continue to supply a drier airmass to the region with just a sct fair weather cumulus field developing in the afternoon. Despite 850mb temps dropping to between 8-9C, decent diurnal mixing and the stronger late March sun should still allow our temperatures to rise to within a couple of degrees of 80. A secondary trough or dry frontal passage will occur Sunday evening setting up several days of dry and seasonable weather for the beginning of next week. && .LONG TERM (Monday through next Friday)... The closed upper low and associated trough will be exiting off the mid-Atlantic coast Sunday night. A low amplitude upper ridge will build in from the west early next week. The ridge flattens to nearly zonal by Thursday as a strong shortwave translates across the northern tier states into New England. The GFS shows a shortwave tracking across Texas Thursday lifting into the Missouri/Tennessee Valleys with a spoke of energy extending SEWD into our region by the end of the period. At the surface, high pressure centered north of the Great Lakes Monday night will drop south-southeast becoming centered east of the Carolina`s on Wednesday. The high slides east thereafter with the ridge axis dropping south across the Florida peninsula and allowing a cold front to drop down from the north. This boundary may slip into our northern zones Friday before lifting north as a warm front late in the day in response to the next cold front advancing from the west. Temperatures will continue above seasonal levels through the extended period. && .AVIATION... SCT TSRA will impact area terminals through the remainder of the afternoon and into the evening. After a break overnight, rain and thunderstorms are expected to resume around sunrise Saturday. Outside of the thunderstorms, expect VFR conditions through the evening, with MVFR cigs late tonight into tomorrow morning. && .MARINE... A weak cold front will approach the forecast water tonight and cross from west to east during the Saturday. Winds may approach cautionary levels at times ahead of the front, but not anticipating advisory conditions. Cold front will exits south of the area Saturday night turning winds offshore for the second half of the weekend. && .FIRE WEATHER... It is likely that many areas will see a wetting rain ahead of an approaching cold front between this afternoon and Saturday afternoon. The cold front will be slow to move across the region on Saturday. However, it does appear that it will clear our Southeast AL and inland FL Panhandle counties (along and north of I-10) early enough to allow afternoon relative humidity to drop below 35 percent. Forecast dispersion indices are not quite high enough to reach red flag criteria and the new forecast ERC values that will come in later this afternoon may drop as well. We therefore do not plan on issuing any red flag products for Saturday at this time. The front will clear the remainder of the forecast area Saturday night setting up a dry and breezy day on Sunday. It will not be quite dry enough to reach red flag criteria across our AL and GA zones. However, the combination of low RH, high dispersion and high 20-ft winds will likely produce red flag conditions across inland portions of FL. Watches and/or warnings will likely be issued by later shifts for Sunday. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 62 82 54 82 50 / 50 60 30 10 0 Panama City 67 80 59 80 58 / 50 60 10 10 0 Dothan 61 83 55 81 53 / 40 40 10 10 0 Albany 61 81 54 79 52 / 50 60 20 10 0 Valdosta 62 80 55 79 53 / 50 60 40 10 0 Cross City 62 81 58 81 51 / 30 60 40 10 0 Apalachicola 67 75 59 77 54 / 50 60 30 10 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...None. GA...None. FL...None. GM...None. && $$ Mroczka/Camp/Barry/Wool
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
331 PM CDT FRI MAR 23 2012 .MESOSCALE DISCUSSION... 1200 PM CDT A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL ILLINOIS. UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE IN CONVECTION THROUGH THE AFTERNOON. CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500 J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH. IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD SEVERE WEATHER WOULD ALSO INCREASE. THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND POSSIBLY AN ISOLATED TORNADO OR TWO. JEE && .DISCUSSION... 340 AM CDT LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT DRY. DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON. ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE 800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO 06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE. BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR. THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES. WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES. GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL ILLINOIS AND WEST CENTRAL INDIANA. LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8 REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF RESPONSIBILITY. SHEA && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * SHRA/TSRA OVER/NEAR THE TERMINALS NEXT 1-2 HRS...MORE ISOLD/SCATTERED ACTIVITY POSSIBLE REMAINDER OF AFTERNOON/EARLY EVENING. * BRIEF IFR POSSIBLE WITH SHRA/TSRA THAT PASS OVERHEAD. * PRIMARILY VFR CIGS ARRIVING WITH PATCHY MVFR REMAINING INTO EARLY EVENING. * MVFR VSBY MAY CONTINUE AT ORD WITH FLOW OFF LAKE MICHIGAN. * EAST TO NORTHEAST WINDS EXPECTED TO CONTINUE THROUGH THE AFTERNOON POTENTIALLY BECOMING EAST-SOUTHEAST YET THIS AFTERNOON BEFORE BECOMING LIGHT AND VARIABLE. MDW SHOULD HAVE THE MOST VARIABILITY. * ANOTHER ROUND OF SHRA/TSRA POSSIBLE THIS EVENING BUT MAY REMAIN JUST TO THE SOUTH. * DECENT POTENTIAL FOR DENSE FOG DEVELOPMENT OVERNIGHT THROUGH DAYBREAK SATURDAY. * IFR IMPROVING TO VFR SATURDAY MORNING AND POSSIBLY VFR SATURDAY AFTERNOON. MDB //DISCUSSION...UPDATED 20Z... BULK OF THE SHRA/TSRA ACTIVITY NOW SKIRTING ORD/MDW/DPA TO THE NORTHEAST AND SHOULD CONTINUE TO LIFT AWAY FROM THE TERMINALS...INCLUDING GYY...OVER THE NEXT HOUR OR SO. PREVAILING CIGS ARE QUICKLY IMPROVING TO VFR AND THIS TREND SHOULD REMAIN INTO THE EVENING AND TAF CIGS MAY BE TOO PESSIMISTIC. CONVECTION MOVING NORTHWARD ACROSS CENTRAL ILLINOIS WILL MAKE A RUN TOWARD THE TERMINALS THIS EVENING BUT IT IS NOT YET CLEAR AS TO HOW ORGANIZED OR WELL DEVELOPED THEY WILL BE AS THEY APPROACH...BUT WILL CONTINUE TO MONITOR. TS MAY NEED TO BE ADDED FOR THE EVENING. WINDS REMAIN VARIABLE WITH SHRA/TSRA STARTING TO IMPACT THE FLOW. EXPECT MAINLY AN EASTERLY DIRECTION WITH FLUCTUATIONS TO NORTHEAST AND SOUTHEAST. CONDS AT RFD HAVE BEEN MORE STEADY STATE WITH MOST SHRA/TSRA ACTIVITY TO THE NORTH AND VFR PREVAILING...BUT WINDS HAVE BEEN MORE VARIABLE BETWEEN SOUTH AND EAST. FROM 18Z... UPPER LOW CONTINUES TO SPIN OVER SOUTHERN MISSOURI RESULTING IN LOW CIGS/VSBY AND SHRA/TSRA. CONDITIONS HIGHLY VARIABLE ACROSS THE TERMINALS WITH THE WORST CONDITIONS ACROSS THE CHICAGO METRO AND NORTHWEST INDIANA. A BAND OF THUNDERSTORMS HAS DEVELOPED OVER THE LAST HOUR OR SO FROM ORD SOUTHWARD AND IS LIFTING NORTH. THE BULK OF THIS ACTIVITY WILL LIFT TO THE NORTH OF THE CHI AREA TERMINALS IN THE NEXT FEW HOURS WITH ADDITIONAL ACTIVITY POSSIBLE THROUGH LATE AFTERNOON BUT APPEARING TO BE MUCH LESS ORGANIZED. IFR/MVFR CIGS CONTINUE IN THIS SAME AREA AND IFR CIGS SHOULD IMPROVE TO LOW END MVFR OVER THE NEXT HOUR OR SO. MVFR CIGS WILL LIKELY PERSIST THROUGH THE AFTERNOON AT DPA/ORD/MDW/GYY WHILE VFR CONTINUES AT RFD. THERE MAY BE SOME IMPROVEMENT TO VFR LATE THIS AFTERNOON AND EARLY THIS EVENING BUT THIS IS NOT YET CLEAR. VARIABLE EAST TO NORTHEAST WINDS WILL CONTINUE AT ORD/MDW/DPA WITH GYY EXPECTED TO FLIP TO EAST OR NORTHEAST SOMETIME LATER THIS AFTERNOON BUT SHOWER ACTIVITY MAY KEEP THIS FROM OCCURRING. ANOTHER ROUND OF CONVECTION SHOULD MOVE NORTHWARD ACROSS CENTRAL ILLINOIS LATE THIS AFTERNOON. THE BIG QUESTION WILL BE HOW FAR NORTH THIS WILL BE ABLE TO MOVE. WILL LIMIT PRECIP/TS MENTION IN THE TAF FOR THIS EVENING BUT WILL NEED TO MONITOR CLOSELY. RIGHT NOW BEST TIME FRAME FOR THIS WOULD BE MID OR LATE EVENING. LOW LEVEL FLOW WILL BECOME LIGHT AND VARIABLE OVERNIGHT WHICH WILL COMBINE WITH MOIST/SATURATED GROUND TO SUPPORT GOOD POTENTIAL FOR FOG DEVELOPMENT. NOT CLEAR HOW LOW VSBY WILL GO BUT 1/2SM OR LESS IS PLAUSIBLE...ESPECIALLY AT DPA/RFD. LESS CONFIDENCE IN VSBY THIS OCCURRING AT ORD/MDW AND EVEN GYY BUT SOME FORM OF IFR VSBY APPEARS LIKELY. NORTH-NORTHEAST FLOW WILL BE IN PLACE SATURDAY AS THE UPPER LOW STARTS TO SHIFT EASTWARD AND IFR SHOULD IMPROVE TO MVFR SOMETIME LATER SATURDAY MORNING...WITH VFR POSSIBLE SOMETIME SATURDAY AFTERNOON. MDB //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH CONFIDENCE IN MOST WIDESPREAD SHRA/TSRA ACTIVITY LIFTING NORTH OF THE TERMINALS NEXT HOUR OR SO. LOW-MEDIUM CONFIDENCE IN SCATTERED/ISOLD POTENTIAL THROUGH EARLY EVENING. * MEDIUM-HIGH CONFIDENCE IN BRIEF IFR OCCURRING WITH ANY PASSING SHRA/TSRA. * MEDIUM-HIGH CONFIDENCE IN PREVAILING CIGS IMPROVING TO VFR AND CONTINUING INTO MID EVENING. * HIGH CONFIDENCE IN GENERAL EAST TO NORTHEAST WIND DIRECTION WITH VARIABILITY BUT MEDIUM CONFIDENCE IN TIMING OF MORE EAST- SOUTHEAST DIRECTION THIS EVENING. * LOW CONFIDENCE IN POTENTIAL FOR ANOTHER ROUND OF SHRA/TSRA EARLY/MID EVENING BUT THIS MAY STAY JUST TO THE SOUTH. * MEDIUM-HIGH CONFIDENCE IN IFR FOG DEVELOPMENT TONIGHT THROUGH MID SATURDAY MORNING WITH LOW-MEDIUM CONFIDENCE IN HOW LOW VSBY WILL BE. * MEDIUM CONFIDENCE IN IFR IMPROVING TO VFR THROUGH SATURDAY BUT LOW CONFIDENCE ON TIMING. MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT. SUNDAY...VFR. MONDAY...VFR. TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS. WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY. THURSDAY...VFR. BEACHLER && .MARINE... 321 PM CDT WHILE THERE MAY BE SOME PATCHY DENSE FOG NEAR THE WESTERN SHORE THROUGH TONIGHT...THE PRIMARY CONCERN IS A PERIOD OF UNSTABLE CONDITIONS LATE SUNDAY INTO EARLY MONDAY...WHICH WILL LEAD TO STRONGER NORTHERLY WINDS. THEN ON TUESDAY...STRONG SOUTHERLY FLOW WILL DEVELOP...BUT THE AIR MASS IS EXPECTED TO BECOME INCREASINGLY STABLE OVER THE LAKE. INITIALLY...BROAD LOW PRESSURE OVER THE OHIO VALLEY WILL SHIFT SLOWLY EAST ACROSS THE OHIO VALLEY THROUGH LATE SATURDAY...WITH WINDS TURNING NORTHERLY BUT REMAINING FAIRLY LIGHT AS THE AIR MASS OVER THE LAKE WILL STILL BE MILD...LEADING TO STABLE CONDITIONS. HOWEVER...ON SUNDAY...A COLD FRONT PASSAGE WILL LEAD TO A SHOT OF REINFORCING COLD AIR AS STRONG HIGH PRESSURE PRESSES DOWN FROM NORTHERN ONTARIO. THIS WILL BE THE FIRST PUSH OF COLD AIR OVER THE LAKE IN QUITE A WHILE...SO THE LAKE IS EXCEPTIONALLY MILD FOR LATE MARCH. THUS...AIR TEMPERATURES BELOW FREEZING ALOFT MOVING OVER THE MILD LAKE WILL ENABLE MIXING DOWN OF STRONGER WINDS AS THE STRONG HIGH PRESSURE BUILDING IN RESULTS IN A TIGHT NORTHERLY PRESSURE GRADIENT. THE COLD AIR WILL TAKE SOME TIME TO DEEPEN...SO THE TARGET PERIOD FOR STRONGEST NORTHERLY WINDS IS SUNDAY NIGHT INTO EARLY MONDAY...STARTING WITH THE NORTH HALF...THEN TRANSITIONING DOWN THE LAKE. HAVE PEGGED THIS TIME FRAME FOR NORTH AND NORTHEAST WINDS UP TO 30 KT...BUT CANNOT RULE OUT LOW END GALES...SO THIS PERIOD WILL NEED TO BE MONITORED. THE STRONG NORTHERLY WINDS AND BUILDING WAVES WILL ALSO LEAD TO A HIGH LIKELIHOOD OF CONDITIONS HAZARDOUS TO SMALL CRAFT FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS LATE SUNDAY NIGHT OR EARLY MONDAY MORNING INTO MONDAY EVENING. WINDS WILL BRIEFLY SUBSIDE AND TURN SOUTHEAST LATE MONDAY NIGHT AS THE HIGH QUICKLY MOVES EAST. STRONG LOW PRESSURE WILL APPROACH THE UPPER GREAT LAKES FROM THE NORTHERN PLAINS ON TUESDAY...STRENGTHENING THE SOUTHERLY FLOW...BUT AT THIS POINT...THE AIR MASS MOVING ACROSS THE LAKE WILL BE MILD...AND GUSTS WILL BE LIMITED BY INCREASINGLY STABLE CONDITIONS. WILL CERTAINLY NEED TO MONITOR THIS PERIOD AS WELL...AS THE WINDS NOT FAR ABOVE THE STABLE LAYER WILL BE QUITE STRONG. COLDER...UNSTABLE CONDITIONS AND STRONGER WESTERLY WINDS WILL RETURN ON WEDNESDAY AFTER THE COLD FRONT TRAILING FROM THE LOW PRESSURE SWEEPS ACROSS THE LAKE. RC && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
306 PM CDT FRI MAR 23 2012 .MESOSCALE DISCUSSION... 1200 PM CDT A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL ILLINOIS. UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE IN CONVECTION THROUGH THE AFTERNOON. CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500 J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH. IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD SEVERE WEATHER WOULD ALSO INCREASE. THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND POSSIBLY AN ISOLATED TORNADO OR TWO. JEE && .DISCUSSION... 340 AM CDT LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT DRY. DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON. ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE 800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO 06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE. BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR. THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES. WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES. GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL ILLINOIS AND WEST CENTRAL INDIANA. LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8 REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF RESPONSIBILITY. SHEA && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * SHRA/TSRA OVER/NEAR THE TERMINALS NEXT 1-2 HRS...MORE ISOLD/SCATTERED ACTIVITY POSSIBLE REMAINDER OF AFTERNOON/EARLY EVENING. * BRIEF IFR POSSIBLE WITH SHRA/TSRA THAT PASS OVERHEAD. * PRIMARILY VFR CIGS ARRIVING WITH PATCHY MVFR REMAINING INTO EARLY EVENING. * MVFR VSBY MAY CONTINUE AT ORD WITH FLOW OFF LAKE MICHIGAN. * EAST TO NORTHEAST WINDS EXPECTED TO CONTINUE THROUGH THE AFTERNOON POTENTIALLY BECOMING EAST-SOUTHEAST YET THIS AFTERNOON BEFORE BECOMING LIGHT AND VARIABLE. MDW SHOULD HAVE THE MOST VARIABILITY. * ANOTHER ROUND OF SHRA/TSRA POSSIBLE THIS EVENING BUT MAY REMAIN JUST TO THE SOUTH. * DECENT POTENTIAL FOR DENSE FOG DEVELOPMENT OVERNIGHT THROUGH DAYBREAK SATURDAY. * IFR IMPROVING TO VFR SATURDAY MORNING AND POSSIBLY VFR SATURDAY AFTERNOON. MDB //DISCUSSION...UPDATED 20Z... BULK OF THE SHRA/TSRA ACTIVITY NOW SKIRTING ORD/MDW/DPA TO THE NORTHEAST AND SHOULD CONTINUE TO LIFT AWAY FROM THE TERMINALS...INCLUDING GYY...OVER THE NEXT HOUR OR SO. PREVAILING CIGS ARE QUICKLY IMPROVING TO VFR AND THIS TREND SHOULD REMAIN INTO THE EVENING AND TAF CIGS MAY BE TOO PESSIMISTIC. CONVECTION MOVING NORTHWARD ACROSS CENTRAL ILLINOIS WILL MAKE A RUN TOWARD THE TERMINALS THIS EVENING BUT IT IS NOT YET CLEAR AS TO HOW ORGANIZED OR WELL DEVELOPED THEY WILL BE AS THEY APPROACH...BUT WILL CONTINUE TO MONITOR. TS MAY NEED TO BE ADDED FOR THE EVENING. WINDS REMAIN VARIABLE WITH SHRA/TSRA STARTING TO IMPACT THE FLOW. EXPECT MAINLY AN EASTERLY DIRECTION WITH FLUCTUATIONS TO NORTHEAST AND SOUTHEAST. CONDS AT RFD HAVE BEEN MORE STEADY STATE WITH MOST SHRA/TSRA ACTIVITY TO THE NORTH AND VFR PREVAILING...BUT WINDS HAVE BEEN MORE VARIABLE BETWEEN SOUTH AND EAST. FROM 18Z... UPPER LOW CONTINUES TO SPIN OVER SOUTHERN MISSOURI RESULTING IN LOW CIGS/VSBY AND SHRA/TSRA. CONDITIONS HIGHLY VARIABLE ACROSS THE TERMINALS WITH THE WORST CONDITIONS ACROSS THE CHICAGO METRO AND NORTHWEST INDIANA. A BAND OF THUNDERSTORMS HAS DEVELOPED OVER THE LAST HOUR OR SO FROM ORD SOUTHWARD AND IS LIFTING NORTH. THE BULK OF THIS ACTIVITY WILL LIFT TO THE NORTH OF THE CHI AREA TERMINALS IN THE NEXT FEW HOURS WITH ADDITIONAL ACTIVITY POSSIBLE THROUGH LATE AFTERNOON BUT APPEARING TO BE MUCH LESS ORGANIZED. IFR/MVFR CIGS CONTINUE IN THIS SAME AREA AND IFR CIGS SHOULD IMPROVE TO LOW END MVFR OVER THE NEXT HOUR OR SO. MVFR CIGS WILL LIKELY PERSIST THROUGH THE AFTERNOON AT DPA/ORD/MDW/GYY WHILE VFR CONTINUES AT RFD. THERE MAY BE SOME IMPROVEMENT TO VFR LATE THIS AFTERNOON AND EARLY THIS EVENING BUT THIS IS NOT YET CLEAR. VARIABLE EAST TO NORTHEAST WINDS WILL CONTINUE AT ORD/MDW/DPA WITH GYY EXPECTED TO FLIP TO EAST OR NORTHEAST SOMETIME LATER THIS AFTERNOON BUT SHOWER ACTIVITY MAY KEEP THIS FROM OCCURRING. ANOTHER ROUND OF CONVECTION SHOULD MOVE NORTHWARD ACROSS CENTRAL ILLINOIS LATE THIS AFTERNOON. THE BIG QUESTION WILL BE HOW FAR NORTH THIS WILL BE ABLE TO MOVE. WILL LIMIT PRECIP/TS MENTION IN THE TAF FOR THIS EVENING BUT WILL NEED TO MONITOR CLOSELY. RIGHT NOW BEST TIME FRAME FOR THIS WOULD BE MID OR LATE EVENING. LOW LEVEL FLOW WILL BECOME LIGHT AND VARIABLE OVERNIGHT WHICH WILL COMBINE WITH MOIST/SATURATED GROUND TO SUPPORT GOOD POTENTIAL FOR FOG DEVELOPMENT. NOT CLEAR HOW LOW VSBY WILL GO BUT 1/2SM OR LESS IS PLAUSIBLE...ESPECIALLY AT DPA/RFD. LESS CONFIDENCE IN VSBY THIS OCCURRING AT ORD/MDW AND EVEN GYY BUT SOME FORM OF IFR VSBY APPEARS LIKELY. NORTH-NORTHEAST FLOW WILL BE IN PLACE SATURDAY AS THE UPPER LOW STARTS TO SHIFT EASTWARD AND IFR SHOULD IMPROVE TO MVFR SOMETIME LATER SATURDAY MORNING...WITH VFR POSSIBLE SOMETIME SATURDAY AFTERNOON. MDB //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH CONFIDENCE IN MOST WIDESPREAD SHRA/TSRA ACTIVITY LIFTING NORTH OF THE TERMINALS NEXT HOUR OR SO. LOW-MEDIUM CONFIDENCE IN SCATTERED/ISOLD POTENTIAL THROUGH EARLY EVENING. * MEDIUM-HIGH CONFIDENCE IN BRIEF IFR OCCURRING WITH ANY PASSING SHRA/TSRA. * MEDIUM-HIGH CONFIDENCE IN PREVAILING CIGS IMPROVING TO VFR AND CONTINUING INTO MID EVENING. * HIGH CONFIDENCE IN GENERAL EAST TO NORTHEAST WIND DIRECTION WITH VARIABILITY BUT MEDIUM CONFIDENCE IN TIMING OF MORE EAST- SOUTHEAST DIRECTION THIS EVENING. * LOW CONFIDENCE IN POTENTIAL FOR ANOTHER ROUND OF SHRA/TSRA EARLY/MID EVENING BUT THIS MAY STAY JUST TO THE SOUTH. * MEDIUM-HIGH CONFIDENCE IN IFR FOG DEVELOPMENT TONIGHT THROUGH MID SATURDAY MORNING WITH LOW-MEDIUM CONFIDENCE IN HOW LOW VSBY WILL BE. * MEDIUM CONFIDENCE IN IFR IMPROVING TO VFR THROUGH SATURDAY BUT LOW CONFIDENCE ON TIMING. MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT. SUNDAY...VFR. MONDAY...VFR. TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS. WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY. THURSDAY...VFR. BEACHLER && .MARINE... 251 AM CDT A COUPLE WEATHER FEATURES CONTINUE TO POSE CHALLENGES TO THE WEATHER ACROSS THE MARINE COMMUNITY...AS AN UPPER LEVEL DISTURBANCE SLOWLY LIFTS NORTHEAST FROM THE CENTRAL PLAINS TOWARDS THE SOUTHERN GREAT LAKES TODAY. MEANWHILE A BROAD AREA OF HIGH PRESSURE OVER NORTHERN MANITOBA WILL DRIFT EAST AND BECOME CENTERED OVER HUDSON BAY TONIGHT INTO SATURDAY. THIS WILL ALLOW A GRADIENT TO STEADILY INCREASE ACROSS THE NORTHERN PORTIONS OF THE LAKE TODAY...WITH WINDS COMING UP TO 15 TO 25 KT. A FEW GUSTS UP TO 30 KT WILL BE POSSIBLE. ELSEWHERE WITH THE LACK OF A STRONG GRADIENT...WINDS WILL BE MUCH LIGHTER FROM THE EAST. THIS WILL ALLOW WAVES TO BE HIGHER ALONG THE WESTERN SIDE OF LAKE MICHIGAN. AT THIS TIME IT DOES NOT APPEAR WAVES WILL BE LARGE ENOUGH TO WARRANT ANY HEADLINES IN THE NEARSHORE WATERS FOR ILLINOIS/NORTHWEST INDIANA. THEN AS THE UPPER LEVEL DISTURBANCE DRIFTS EAST...A WEAK LOW PRESSURE SYSTEM WILL TRAVERSE LAKE SUPERIOR. BEHIND THIS SYSTEM ON SUNDAY...A STRONG HIGH PRESSURE WILL BUILD IN AND TIGHTEN THE GRADIENT YET AGAIN. THIS SHOULD ALLOW WINDS TO STEADILY INCREASE. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
130 PM CDT FRI MAR 23 2012 .MESOSCALE DISCUSSION... 1200 PM CDT A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL ILLINOIS. UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE IN CONVECTION THROUGH THE AFTERNOON. CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500 J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH. IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD SEVERE WEATHER WOULD ALSO INCREASE. THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND POSSIBLY AN ISOLATED TORNADO OR TWO. JEE && .DISCUSSION... 340 AM CDT LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT DRY. DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON. ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE 800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO 06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE. BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR. THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES. WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES. GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL ILLINOIS AND WEST CENTRAL INDIANA. LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8 REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF RESPONSIBILITY. SHEA && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * SHRA/TSRA AFFECTING THE TERMINALS EARLY THIS AFTERNOON. * PERIODIC IFR VSBY IN SHRA/TSRA NEXT FEW HOURS. * IFR CIGS EXPECTED TO SCATTER NEXT FEW HOURS...WITH MVFR INTO LATE AFTERNOON. * EAST TO NORTHEAST WINDS EXPECTED TO CONTINUE THROUGH THE AFTERNOON POTENTIALLY BECOMING EAST-SOUTHEAST EARLY THIS AFTERNOON BEFORE BECOMING LIGHT AND VARIABLE. * ANOTHER ROUND OF SHRA/TSRA POSSIBLE THIS EVENING BUT MAY REMAIN JUST TO THE SOUTH. * DECENT POTENTIAL FOR DENSE FOG DEVELOPMENT OVERNIGHT THROUGH DAYBREAK SATURDAY. * IFR IMPROVING TO VFR SATURDAY MORNING AND POSSIBLY VFR SATURDAY AFTERNOON. MDB //DISCUSSION...UPDATED 18Z... UPPER LOW CONTINUES TO SPIN OVER SOUTHERN MISSOURI RESULTING IN LOW CIGS/VSBY AND SHRA/TSRA. CONDITIONS HIGHLY VARIABLE ACROSS THE TERMINALS WITH THE WORST CONDITIONS ACROSS THE CHICAGO METRO AND NORTHWEST INDIANA. A BAND OF THUNDERSTORMS HAS DEVELOPED OVER THE LAST HOUR OR SO FROM ORD SOUTHWARD AND IS LIFTING NORTH. THE BULK OF THIS ACTIVITY WILL LIFT TO THE NORTH OF THE CHI AREA TERMINALS IN THE NEXT FEW HOURS WITH ADDITIONAL ACTIVITY POSSIBLE THROUGH LATE AFTERNOON BUT APPEARING TO BE MUCH LESS ORGANIZED. IFR/MVFR CIGS CONTINUE IN THIS SAME AREA AND IFR CIGS SHOULD IMPROVE TO LOW END MVFR OVER THE NEXT HOUR OR SO. MVFR CIGS WILL LIKELY PERSIST THROUGH THE AFTERNOON AT DPA/ORD/MDW/GYY WHILE VFR CONTINUES AT RFD. THERE MAY BE SOME IMPROVEMENT TO VFR LATE THIS AFTERNOON AND EARLY THIS EVENING BUT THIS IS NOT YET CLEAR. VARIABLE EAST TO NORTHEAST WINDS WILL CONTINUE AT ORD/MDW/DPA WITH GYY EXPECTED TO FLIP TO EAST OR NORTHEAST SOMETIME LATER THIS AFTERNOON BUT SHOWER ACTIVITY MAY KEEP THIS FROM OCCURRING. ANOTHER ROUND OF CONVECTION SHOULD MOVE NORTHWARD ACROSS CENTRAL ILLINOIS LATE THIS AFTERNOON. THE BIG QUESTION WILL BE HOW FAR NORTH THIS WILL BE ABLE TO MOVE. WILL LIMIT PRECIP/TS MENTION IN THE TAF FOR THIS EVENING BUT WILL NEED TO MONITOR CLOSELY. RIGHT NOW BEST TIME FRAME FOR THIS WOULD BE MID OR LATE EVENING. LOW LEVEL FLOW WILL BECOME LIGHT AND VARIABLE OVERNIGHT WHICH WILL COMBINE WITH MOIST/SATURATED GROUND TO SUPPORT GOOD POTENTIAL FOR FOG DEVELOPMENT. NOT CLEAR HOW LOW VSBY WILL GO BUT 1/2SM OR LESS IS PLAUSIBLE...ESPECIALLY AT DPA/RFD. LESS CONFIDENCE IN VSBY THIS OCCURRING AT ORD/MDW AND EVEN GYY BUT SOME FORM OF IFR VSBY APPEARS LIKELY. NORTH-NORTHEAST FLOW WILL BE IN PLACE SATURDAY AS THE UPPER LOW STARTS TO SHIFT EASTWARD AND IFR SHOULD IMPROVE TO MVFR SOMETIME LATER SATURDAY MORNING...WITH VFR POSSIBLE SOMETIME SATURDAY AFTERNOON. MDB //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN SHRA/TSRA MOVING ACROSS NEXT FEW HOURS. * MEDIUM-HIGH CONFIDENCE IN PERIODIC IFR VSBY IN SHRA/TSRA. * HIGH CONFIDENCE IN IFR CIGS CONTINUING NEXT HOUR OR SO BUT LOW CONFIDENCE ON HOW LONG IT WILL TAKE TO SCATTER. * HIGH CONFIDENCE IN GENERAL EAST TO NORTHEAST WIND DIRECTION WITH VARIABILITY BUT MEDIUM CONFIDENCE IN TIMING OF MORE EAST- SOUTHEAST DIRECTION. * LOW CONFIDENCE IN POTENTIAL FOR ANOTHER ROUND OF SHRA/TSRA EARLY/MID EVENING BUT THIS MAY STAY JUST TO THE SOUTH. * MEDIUM-HIGH CONFIDENCE IN IFR FOG DEVELOPMENT TONIGHT THROUGH MID SATURDAY MORNING WITH LOW-MEDIUM CONFIDENCE IN HOW LOW VSBY WILL BE. * MEDIUM CONFIDENCE IN IFR IMPROVING TO VFR THROUGH SATURDAY BUT LOW CONFIDENCE ON TIMING. MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT. SUNDAY...VFR. MONDAY...VFR. TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS. WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY. THURSDAY...VFR. BEACHLER && .MARINE... 251 AM CDT A COUPLE WEATHER FEATURES CONTINUE TO POSE CHALLENGES TO THE WEATHER ACROSS THE MARINE COMMUNITY...AS AN UPPER LEVEL DISTURBANCE SLOWLY LIFTS NORTHEAST FROM THE CENTRAL PLAINS TOWARDS THE SOUTHERN GREAT LAKES TODAY. MEANWHILE A BROAD AREA OF HIGH PRESSURE OVER NORTHERN MANITOBA WILL DRIFT EAST AND BECOME CENTERED OVER HUDSON BAY TONIGHT INTO SATURDAY. THIS WILL ALLOW A GRADIENT TO STEADILY INCREASE ACROSS THE NORTHERN PORTIONS OF THE LAKE TODAY...WITH WINDS COMING UP TO 15 TO 25 KT. A FEW GUSTS UP TO 30 KT WILL BE POSSIBLE. ELSEWHERE WITH THE LACK OF A STRONG GRADIENT...WINDS WILL BE MUCH LIGHTER FROM THE EAST. THIS WILL ALLOW WAVES TO BE HIGHER ALONG THE WESTERN SIDE OF LAKE MICHIGAN. AT THIS TIME IT DOES NOT APPEAR WAVES WILL BE LARGE ENOUGH TO WARRANT ANY HEADLINES IN THE NEARSHORE WATERS FOR ILLINOIS/NORTHWEST INDIANA. THEN AS THE UPPER LEVEL DISTURBANCE DRIFTS EAST...A WEAK LOW PRESSURE SYSTEM WILL TRAVERSE LAKE SUPERIOR. BEHIND THIS SYSTEM ON SUNDAY...A STRONG HIGH PRESSURE WILL BUILD IN AND TIGHTEN THE GRADIENT YET AGAIN. THIS SHOULD ALLOW WINDS TO STEADILY INCREASE. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1257 PM CDT FRI MAR 23 2012 .DISCUSSION... ISSUED 1005 AM CDT FRI MAR 23 2012 LARGE STACKED LOW SPINNING OVER THE SOUTHEAST TIP OF KANSAS PER WATER VAPOR IMAGERY...WITH SURFACE OBS AND RADAR IMAGERY SHOWING A SECONDARY LOW PRESSURE AREA OVER CENTRAL MISSOURI. HAD QUITE A BIT OF FOG DEVELOP OVER THE WESTERN 2/3 OF THE CWA EARLIER...BUT VISIBILITIES WERE RAPIDLY IMPROVING BY 9 AM AND LATEST OBSERVATIONS SHOWING MOST SITES ABOVE 4 MILES THIS HOUR. HAVE BEEN SEEING A RAPID INCREASE IN SHOWERS AND STORMS OVER SOUTHEAST MISSOURI RECENTLY...WITH A FEW SHOWERS/STORMS NOW MOVING INTO FAR SOUTHERN PARTS OF OUR CWA. 12Z SOUNDING FROM SPRINGFIELD MO SHOWED 500 MB TEMPERATURES OF -26C ASSOCIATED WITH THE UPPER LOW...WHICH WILL TRACK EASTWARD ACROSS SOUTHERN MISSOURI THIS AFTERNOON. THIS WILL ENHANCE MID-LEVEL LAPSE RATES...WITH LATEST RUC MODEL SHOWING RATES OF AROUND 7.5 TO 8C/KM OVER OUR AREA BY EARLY AFTERNOON SUPPORTING HAIL DEVELOPMENT WITH THE STRONGER STORMS. SEVERE WEATHER POTENTIAL STILL EXISTS BECAUSE OF THIS...WITH AREAS SOUTHEAST OF I-55 MOST AT RISK. UPDATED GRIDS HAVE BEEN SENT...WITH UPDATED ZONES TO FOLLOW AROUND 1015 AM. MOST CHANGES WERE IN THE PRECIP/WEATHER TYPES...WITH SOME ADJUSTMENTS TO THE HOURLY GRIDS FOR OTHER ELEMENTS. GEELHART && .AVIATION... ISSUED 1257 PM CDT FRI MAR 23 2012...FOR THE 12Z TAFS SHOWERS ARE BEGINNING TO RETURN TO CENTRAL IL FROM THE SOUTH AS INSTABILITY INCREASES AHEAD OF THE LOW PRESSURE SYSTEM. THE NEXT BAND OF STORMS MAY CONTAIN HAIL...BUT THE SEVERE THUNDERSTORM WATCH UNTIL 7 PM DOES NOT INCLUDE ANY OF THE TERMINAL SITES. WE INCLUDED A 3 HOUR TEMPO FOR TSRAGS AT SPI/DEC/CMI THIS AFTERNOON TO COVER THE HIGHER THREAT AREAS FOR SMALLER HAIL THAN 1 INCH. THE MAIN WINDOW FOR HAIL LOOKS TO BE 20Z-23Z. MVFR CONDITIONS WILL BE LIKELY DURING STORMS...WITH IFR POSSIBLE. THERE MAY BE A BREAK BETWEEN LINES OF STORMS AFTER THAT 23Z- 00Z...BUT THAT TREND WILL BECOME BETTER DEFINED LATER THIS AFTERNOON. WILL NOT ADD ADDITIONAL PERIODS OF STORMS FOR TONIGHT JUST YET. WINDS WILL BE VARIABLE AS THE LOW APPROACHES FROM SOUTHWEST MISSOURI. THE LOW SHOULD MOVE ACROSS SOUTH CENTRAL IL...SO THE PREVAILING WIND DIRECTION SHOULD BE SOUTHEAST UNTIL LATER TONIGHT...WHEN THE WINDS SHIFT AROUND TO THE WEST. SHIMON && .PREV DISCUSSION... ISSUED 330 AM CDT FRI MAR 23 2012 SHORT TERM...TODAY THROUGH MONDAY NIGHT 00Z MODELS REMAIN IN FAIR AGREEMENT THROUGH THIS WEEKEND AND WILL USE A BLEND. MET AND MAV GUIDANCE TEMPS SIMILAR THROUGH THIS WEEKEND AND STAYED CLOSE TOO. GUIDANCE CONTINUES TO GO WARMER ON SUNDAY AND HAS HIGHS IN THE MID 70S MOST AREAS AND TRENDED THE FORECAST IN THAT DIRECTION. COOLER TEMPERATURES EXPECTED LATE THIS WEEK THOUGH STILL 10-15 DEGREES ABOVE NORMAL AND SUNDAY NOW LOOKS WARMER IN THE 70S. UNSETTLED WEATHER PATTERN EXPECTED THROUGH SAT DUE TO 551 DM 500 MB LOW OVER SOUTHEAST KS THAT SLOWLY WEAKENS IT IT MOVES INTO SE MO BY SUNSET AND THEN INTO SOUTH CENTRAL KY/MID TN BY SUNSET SAT. SPC HAS MUCH OF CENTRAL/SE IL INTO THE LOWER OHIO VALLEY IN A SLIGHT RISK THIS AFTERNOON FOR MAINLY LARGE HAIL (15%) RISK WHILE WINDS AND ISOLATED TORNADOES ARE JUST 5% RISK. SHOWERS AND ISOLATED THUNDERSTORMS OVER INDIANA AND NE IL DRIFTING NNW AROUND THE 551 DM 500 MB LOW OVER SE KS. A SMALL BAND OF SHOWERS AND A FEW THUNDERSTORMS OVER CENTRAL AND SOUTH CENTRAL MO CLOSER TO THE UPPER LEVEL LOW. DRY WEDGE IN BETWEEN OVER CENTRAL AND SW IL AND SOME CLEARING FROM LINCOLN SW HAS ALLOWED SOME FOG TO FORM EARLY THIS MORNING...EVEN DENSE FOG AT MACOMB...KEOKUK AND PITTSFIELD IN WEST CENTRAL IL. VSBYS GENERALLY 3-5 MILES WEST OF LINCOLN AND MAY NEED TO ADD FOG TO THE FORECAST FOR THESE AREAS INTO MID MORNING AND VSBYS LIKELY DROP FURTHER. EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP BY MIDDAY AND BECOME MORE WIDESPREAD DURING THE AFTERNOON AS UPPER LEVEL LOW MOVES INTO SOUTHERN MO AND AIRMASS GETS MORE UNSTABLE AND HAVE LIKELY TO EVEN CATEGORICAL POPS THIS AFTERNOON OVER SW AREAS. PER SPC DAY1 OUTLOOK...BAND/ARC OF THUNDERSTORMS IS EXPECTED TO INCREASE IN COVERAGE/INTENSITY FROM MIDDAY THROUGH AT LEAST MID AFTERNOON...IN ZONE OF CONVERGENCE LOCATED NE-E OF DEEP- LAYER LOW. COLD CORE CONVECTIVE REGIME FCST TO SHIFT EWD/NEWD ACROSS OUTLOOK AREA...WITH DOMINANT THREAT BEING LARGE HAIL...ISOLATED DAMAGING GUSTS POSSIBLE. TORNADO POTENTIAL APPEARS CONDITIONAL/MARGINAL ON OUTLOOK SCALE ATTM...BUT MAY BE LOCALLY ENHANCED BY STORM INTERACTIONS WITH BANNERS OF BOUNDARY- LAYER VORTICITY. ENHANCED/7.5-8.5 DEG C/KM MID LEVEL LAPSE RATES AND MID 50S TO NEAR 60 F SFC DEW POINTS WILL JUXTAPOSE WITH SURFACE HEATING TO SUPPORT 600-1200 J/KG MLCAPE...AMIDST 30-45 KT EFFECTIVE SHEAR MAGNITUDES. THUNDERSTORMS SHOULD DIMINISH DURING EARLY THIS EVENING WITH LOSS OF DAYTIME HEATING. SHOWERS TO DIMINISH OVERNIGHT AND THEN INCREASE AGAIN BY SAT AFTERNOON WITH ISOLATED THUNDERSTORMS POSSIBLE OVER EASTERN/SE IL SAT AFTERNOON ESPECIALLY NEAR THE WABASH RIVER WHERE SHOWERS MAY LINGER EARLY SAT EVENING BY LAWRENCEVILLE. UPPER LEVEL LOW SLOWLY WEAKENS AS IT DRIFTS ESE INTO EASTERN TN BY MIDNIGHT SAT NIGHT. NICE WEATHER EXPECTED EARLY NEXT WEEK WITH UPPER LEVEL LOW PULLING AWAY INTO THE SE STATES AND STRONG UPPER LEVEL RIDGING OVER THE GREAT PLAINS SHIFTING EASTWARD INTO THE MS VALLEY BY MON NIGHT AND INTO IL TUE. 850 MB TEMPS WARM UP SUNDAY TO 10C OR WARMER SW AREAS AND GIVES HIGHS IN THE LOW TO MID 70S. BACKDOOR COLD FRONT TO MOVE FROM THE GREAT LAKES REGION THROUGH IL EARLY NEXT WEEK...COOLING TEMPS MONDAY ESPECIALLY NE AREAS BUT DRY CONDITIONS EXPECTED SUNDAY THROUGH TUE. LONG TERM...TUESDAY THROUGH FRIDAY A PROGRESSIVE NORTHERN STREAM WEATHER SYSTEM TRACKING EAST ALONG THE US/CANADIAN BORDER TO PUSH A COLD FRONT THROUGH IL TUE NIGHT AND THEN STALL OUT NEAR THE OHIO RIVER WED BEFORE LIFTING BACK NORTH LATER NEXT WEEK. THIS TO BRING CHANCES OF SHOWERS/THUNDERSTORMS BY TUE NIGHT AND MAINLY IN SE IL WED AND THEN HAVE SLIGHT CHANCES OF CONVECTION LATE NEXT WORK WEEK WITH FRONT LIFTING BACK NORTH. TEMPS OVERALL TO REMAIN ABOVE NORMAL AND NO FROST OR FREEZE EXPECTED THROUGH NEXT WEEK. HUETTL && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1256 PM CDT FRI MAR 23 2012 .MESOSCALE DISCUSSION... 1200 PM CDT A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL ILLINOIS. UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE IN CONVECTION THROUGH THE AFTERNOON. CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500 J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH. IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD SEVERE WEATHER WOULD ALSO INCREASE. THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND POSSIBLY AN ISOLATED TORNADO OR TWO. JEE && .DISCUSSION... 340 AM CDT LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT DRY. DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON. ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE 800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO 06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE. BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR. THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES. WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES. GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL ILLINOIS AND WEST CENTRAL INDIANA. LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8 REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF RESPONSIBILITY. SHEA && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * OCCASIONAL SHOWERS THROUGH LATE MORNING. * VARIABLE VSBY/CIGS WITH LOWEST IN/AROUND SHOWERS...BRIEF IFR IN SHRA. * ORD VSBY LIKELY STAYING MVFR WITH COOLER NORTHEASTERLY WIND FLOW. * LIGHT NORTHEAST WINDS AT ORD PERSISTING THROUGH MID AFTERNOON. * LIGHT SOUTHEAST WINDS AT MDW SHOULD BECOME MORE EAST THEN NORTHEAST INTO EARLY AFTERNOON. * DECENT CHANCE FOR SCATTERED TS DEVELOPMENT THIS AFTERNOON. * MAY SEE VARIABLE MVFR/VFR CIG/VSBY AWAY FROM SHRA/TSRA THIS AFTERNOON. MDB //DISCUSSION...UPDATED 16Z... VARIABLE CONDITIONS REMAIN ACROSS THE TERMINALS WITH EVERYTHING FROM IFR TO VFR. BANDS OF SHOWERS CONTINUE TO ARC NORTHWARD FROM UGN TO ORD TO MDW TO LAF. THIS ACTIVITY WILL CONTINUE TO SLOWLY SHIFT TO THE EAST OVER THE NEXT FEW HOURS BUT WILL BRING PERIODIC REDUCTIONS TO IFR VSBY. A CORRIDOR OF IFR CIGS HAS DEVELOP NEAR AND UNDER THE SHOWER ACTIVITY STRETCHING AS FAR WEST AS DPA BUT THIS SHOULD IMPROVE INTO EARLY THIS AFTERNOON. PREVAILING CIG/VSBY TRENDS NOT AS CLEAR FOR THE AFTERNOON AS THEY WERE BUT EXPECT THAT MVFR WILL PREVAIL TO START BUT THERE MAY BE IMPROVEMENT TO MVFR AT SOME POINT. FLOW OFF THE LAKE ACROSS THE CHI METRO MAY KEEP LOWER CIGS AND VSBY IN PLACE AT ORD/MDW AND PERHAPS EVENTUALLY GYY CONFIDENCE IN THE SPECIFICS IS LIMITED. EXPECT THAT ORD WILL KEEP A NE WIND WITH MDW ON THE FRINGE OF THE LAKE FLOW BUT LIKELY REMAINING EAST OR EAST-NORTHEAST. DPA WILL LIKELY BE IN THE SAME SCENARIO...WITH GYY EXPECTED TO FLIP NORTHEAST AT SOME POINT THIS AFTERNOON. RFD SHOULD STAT MORE SOUTHEAST BEFORE SHIFTING EAST AND NORTHEAST LATER TODAY. NEXT CONCERN IS POTENTIAL FOR NEW SHRA/TSRA DEVELOPMENT THIS AFTERNOON. AM CONCERNED ABOUT NEW DEVELOPMENT IN AN AREA OF SCATTERED/CLEAR SKIES FROM SQI-RFD-NEAR IKK-PNT WITH SOME INSTABILITY BUILDING AS A RESULT. THIS DEVELOPMENT MAY OCCUR BY EARLY AFTERNOON AND LIFT NORTHEAST BUT THIS WILL REMAIN TO BE SEEN. ANOTHER ROUND OF CONVECTION WILL BE POSSIBLE LATER THIS EVENING BUT CONFIDENCE IN THIS IS NOT HIGH. MDB FROM 12Z... VERY CHALLENGING AVIATION FORECAST CONTINUES WITH PERIODIC SHRA/ISO TS. GUIDANCE CONTINUES TO SLIDE THE UPPER LEVEL DISTURBANCE ACROSS CENTRAL IL. IR IMAGERY INDICATED SOME THINNING WAS TAKING PLACE ACROSS A NARROW CHANNEL FROM NORTHWEST IL STRETCHING SOUTHEAST THROUGH CENTRAL IL/SOUTHERN IL. IN THIS COLUMN CIGS/VSBYS HAVE REDUCED TO MVFR WITH PATCHY IFR. IT DOES NOT APPEAR THAT THIS WILL IMPACT THE NORTHERN IL AIRFIELDS AT THIS POINT...HOWEVER SLIGHT REDUCTION IN CIGS/VSBYS MAY OCCUR DUE TO THE RECENT RAINFALL AND LACK OF MIXING TO SCOUR LLVL MOISTURE. HAVE HANDLED THIS WITH SLIGHT REDUCTION OF CIGS TO MVFR. INCREASED INSTABILITY COULD RESULT IN ANOTHER ROUND OF SHRA/TSRA DURING THE AFTN/EVE HOURS BEFORE COMING TO AN END EARLY SAT MORNING. HOWEVER...IT APPEARS THAT SOME FG WILL BEGIN TO FORM LATE FRI NIGHT AND COULD PRODUCE A FEW AREAS OF DENSE FOG GIVEN THE RECENT RAINFALL. THE OTHER AVIATION CHALLENGE OVERNIGHT WILL CONTINUE TO REVOLVE AROUND WIND DIR. WITH THE LACK OF A SOLID GRADIENT TO PRODUCE A PREVAILING WIND DIR...WINDS CONTINUE TO BE FLUID BETWEEN 040-110 DEG ARND 4 TO 6 KT. EXPECT A SLIGHT INCREASE IN THE GRADIENT OVER THE NEXT FEW HOURS AND SHUD PROVIDE A MORE DEFINED DIR...HOWEVER THE UPPER LEVEL DISTURBANCE WILL BE TRAVERSING THE REGION AND STILL PROVIDE CHANGING WIND DIR FROM THE NE TO SE. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE IN SHRA CONTINUING FOR SEVERAL HOURS THIS MORNING. * HIGH CONFIDENCE IN VARIABLE CIG/VSBY THIS MORNING...WITH BRIEF IFR IN SHRA. * MEDIUM-HIGH CONFIDENCE IN ORD VSBY REMAINING MVFR OUTSIDE OF SHRA THIS MORNING. * MEDIUM CONFIDENCE IN WIND DIRECTION TRENDS AT ORD. * LOW-MEDIUM CONFIDENCE IN WIND DIRECTION TRENDS AT MDW. * MEDIUM CONFIDENCE IN SHRA/TSRA DEVELOPMENT THIS AFTERNOON BUT LOW CONFIDENCE IN TIMING/EXTENT OF IMPACTS AT THE TERMINALS. * LOW-MEDIUM CONFIDENCE IN CIG/VSBY TRENDS THIS AFTERNOON. MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT. SUNDAY...VFR. MONDAY...VFR. TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS. WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY. THURSDAY...VFR. BEACHLER && .MARINE... 251 AM CDT A COUPLE WEATHER FEATURES CONTINUE TO POSE CHALLENGES TO THE WEATHER ACROSS THE MARINE COMMUNITY...AS AN UPPER LEVEL DISTURBANCE SLOWLY LIFTS NORTHEAST FROM THE CENTRAL PLAINS TOWARDS THE SOUTHERN GREAT LAKES TODAY. MEANWHILE A BROAD AREA OF HIGH PRESSURE OVER NORTHERN MANITOBA WILL DRIFT EAST AND BECOME CENTERED OVER HUDSON BAY TONIGHT INTO SATURDAY. THIS WILL ALLOW A GRADIENT TO STEADILY INCREASE ACROSS THE NORTHERN PORTIONS OF THE LAKE TODAY...WITH WINDS COMING UP TO 15 TO 25 KT. A FEW GUSTS UP TO 30 KT WILL BE POSSIBLE. ELSEWHERE WITH THE LACK OF A STRONG GRADIENT...WINDS WILL BE MUCH LIGHTER FROM THE EAST. THIS WILL ALLOW WAVES TO BE HIGHER ALONG THE WESTERN SIDE OF LAKE MICHIGAN. AT THIS TIME IT DOES NOT APPEAR WAVES WILL BE LARGE ENOUGH TO WARRANT ANY HEADLINES IN THE NEARSHORE WATERS FOR ILLINOIS/NORTHWEST INDIANA. THEN AS THE UPPER LEVEL DISTURBANCE DRIFTS EAST...A WEAK LOW PRESSURE SYSTEM WILL TRAVERSE LAKE SUPERIOR. BEHIND THIS SYSTEM ON SUNDAY...A STRONG HIGH PRESSURE WILL BUILD IN AND TIGHTEN THE GRADIENT YET AGAIN. THIS SHOULD ALLOW WINDS TO STEADILY INCREASE. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1007 AM CDT FRI MAR 23 2012 .DISCUSSION... ISSUED 1005 AM CDT FRI MAR 23 2012 LARGE STACKED LOW SPINNING OVER THE SOUTHEAST TIP OF KANSAS PER WATER VAPOR IMAGERY...WITH SURFACE OBS AND RADAR IMAGERY SHOWING A SECONDARY LOW PRESSURE AREA OVER CENTRAL MISSOURI. HAD QUITE A BIT OF FOG DEVELOP OVER THE WESTERN 2/3 OF THE CWA EARLIER...BUT VISIBILITIES WERE RAPIDLY IMPROVING BY 9 AM AND LATEST OBSERVATIONS SHOWING MOST SITES ABOVE 4 MILES THIS HOUR. HAVE BEEN SEEING A RAPID INCREASE IN SHOWERS AND STORMS OVER SOUTHEAST MISSOURI RECENTLY...WITH A FEW SHOWERS/STORMS NOW MOVING INTO FAR SOUTHERN PARTS OF OUR CWA. 12Z SOUNDING FROM SPRINGFIELD MO SHOWED 500 MB TEMPERATURES OF -26C ASSOCIATED WITH THE UPPER LOW...WHICH WILL TRACK EASTWARD ACROSS SOUTHERN MISSOURI THIS AFTERNOON. THIS WILL ENHANCE MID-LEVEL LAPSE RATES...WITH LATEST RUC MODEL SHOWING RATES OF AROUND 7.5 TO 8C/KM OVER OUR AREA BY EARLY AFTERNOON SUPPORTING HAIL DEVELOPMENT WITH THE STRONGER STORMS. SEVERE WEATHER POTENTIAL STILL EXISTS BECAUSE OF THIS...WITH AREAS SOUTHEAST OF I-55 MOST AT RISK. UPDATED GRIDS HAVE BEEN SENT...WITH UPDATED ZONES TO FOLLOW AROUND 1015 AM. MOST CHANGES WERE IN THE PRECIP/WEATHER TYPES...WITH SOME ADJUSTMENTS TO THE HOURLY GRIDS FOR OTHER ELEMENTS. GEELHART && .AVIATION... ISSUED 647 AM CDT FRI MAR 23 2012 COMPLEX AVIATION FORECAST THIS PACKAGE. SITES THAT SAW SOME CLEARING OVERNIGHT HAVE NOW BEEN REDUCED TO LIFR AND VLIFR...EITHER DUE TO FOG AND/OR THE LOWER CIGS. THESE CONDITIONS SHOULD CONTINUE FOR A FEW HOURS THIS MORNING. AS THE SUN COMES UP AND BURNS SOME OF THE LOWER CIGS AND FOG OFF THIS MORNING...CONDITIONS SHOULD IMPROVE TO MVFR. IN ADDITION...SHOWERS WILL MOVE BACK INTO THE AREA AT ALL SITES WITH 5SM BR. BELIEVE ISOLATED THUNDERSTORMS ARE ALSO POSSIBLE SO WILL HAVE VCTS AT ALL SITES FOR THE AFTERNOON AND EARLY EVENING HOURS. ONCE THE PCPN ENDS...CONDITIONS SHOULD IMPROVE TO VFR FOR REST OF THE NIGHT AND OVERNIGHT. PRESSURE GRADIENT IS VERY WEAK SO EXPECT LIGHT WINDS TO BECOME SOUTHEAST FOR LATER THIS MORNING...THROUGH THIS AFTERNOON AND THIS EVENING. THEN LIGHT WINDS ARE EXPECTED AGAIN OVERNIGHT. AUTEN && .PREV DISCUSSION... ISSUED 330 AM CDT FRI MAR 23 2012 SHORT TERM...TODAY THROUGH MONDAY NIGHT 00Z MODELS REMAIN IN FAIR AGREEMENT THROUGH THIS WEEKEND AND WILL USE A BLEND. MET AND MAV GUIDANCE TEMPS SIMILAR THROUGH THIS WEEKEND AND STAYED CLOSE TOO. GUIDANCE CONTINUES TO GO WARMER ON SUNDAY AND HAS HIGHS IN THE MID 70S MOST AREAS AND TRENDED THE FORECAST IN THAT DIRECTION. COOLER TEMPERATURES EXPECTED LATE THIS WEEK THOUGH STILL 10-15 DEGREES ABOVE NORMAL AND SUNDAY NOW LOOKS WARMER IN THE 70S. UNSETTLED WEATHER PATTERN EXPECTED THROUGH SAT DUE TO 551 DM 500 MB LOW OVER SOUTHEAST KS THAT SLOWLY WEAKENS IT IT MOVES INTO SE MO BY SUNSET AND THEN INTO SOUTH CENTRAL KY/MID TN BY SUNSET SAT. SPC HAS MUCH OF CENTRAL/SE IL INTO THE LOWER OHIO VALLEY IN A SLIGHT RISK THIS AFTERNOON FOR MAINLY LARGE HAIL (15%) RISK WHILE WINDS AND ISOLATED TORNADOES ARE JUST 5% RISK. SHOWERS AND ISOLATED THUNDERSTORMS OVER INDIANA AND NE IL DRIFTING NNW AROUND THE 551 DM 500 MB LOW OVER SE KS. A SMALL BAND OF SHOWERS AND A FEW THUNDERSTORMS OVER CENTRAL AND SOUTHCENTRAL MO CLOSER TO THE UPPER LEVEL LOW. DRY WEDGE INBETWEEN OVER CENTRAL AND SW IL AND SOME CLEARING FROM LINCOLN SW HAS ALLOWED SOME FOG TO FORM EARLY THIS MORNING...EVEN DENSE FOG AT MACOMB...KEOKUK AND PITTSFIELD IN WEST CENTRAL IL. VSBYS GENERALLY 3-5 MILES WEST OF LINCOLN AND MAY NEED TO ADD FOG TO THE FORECAST FOR THESE AREAS INTO MID MORNING AND VSBYS LIKELY DROP FURTHER. EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP BY MIDDAY AND BECOME MORE WIDESPREAD DURING THE AFTERNOON AS UPPER LEVEL LOW MOVES INTO SOUTHERN MO AND AIRMASS GETS MORE UNSTABLE AND HAVE LIKELY TO EVEN CATEGORICAL POPS THIS AFTERNOON OVER SW AREAS. PER SPC DAY1 OUTLOOK...BAND/ARC OF THUNDERSTORMS IS EXPECTED TO INCREASE IN COVERAGE/INTENSITY FROM MIDDAY THROUGH AT LEAST MID AFTERNOON...IN ZONE OF CONVERGENCE LOCATED NE-E OF DEEP- LAYER LOW. COLD CORE CONVECTIVE REGIME FCST TO SHIFT EWD/NEWD ACROSS OUTLOOK AREA...WITH DOMINANT THREAT BEING LARGE HAIL...ISOLATED DAMAGING GUSTS POSSIBLE. TORNADO POTENTIAL APPEARS CONDITIONAL/MARGINAL ON OUTLOOK SCALE ATTM...BUT MAY BE LOCALLY ENHANCED BY STORM INTERACTIONS WITH BANNERS OF BOUNDARY- LAYER VORTICITY. ENHANCED/7.5-8.5 DEG C/KM MID LEVEL LAPSE RATES AND MID 50S TO NEAR 60 F SFC DEW POINTS WILL JUXTAPOSE WITH SURFACE HEATING TO SUPPORT 600-1200 J/KG MLCAPE...AMIDST 30-45 KT EFFECTIVE SHEAR MAGNITUDES. THUNDERSTORMS SHOULD DIMINISH DURING EARLY THIS EVENING WITH LOSS OF DAYTIME HEATING. SHOWERS TO DIMINISH OVERNIGHT AND THEN INCREASE AGAIN BY SAT AFTERNOON WITH ISOLATED THUNDERSTORMS POSSIBLE OVER EASTERN/SE IL SAT AFTEROON ESPECIALLY NEAR THE WABASH RIVER WHERE SHOWERS MAY LINGER EARLY SAT EVENING BY LAWRENCEVILLE. UPPER LEVEL LOW SLOWLY WEAKENS AS IT DRIFTS ESE INTO EASTERN TN BY MIDNIGHT SAT NIGHT. NICE WEATHER EXPECTED EARLY NEXT WEEK WITH UPPER LEVEL LOW PULLING AWAY INTO THE SE STATES AND STRONG UPPER LEVEL RIDGING OVER THE GREAT PLAINS SHIFTING EASTWARD INTO THE MS VALLEY BY MON NIGHT AND INTO IL TUE. 850 MB TEMPS WARM UP SUNDAY TO 10C OR WARMER SW AREAS AND GIVES HIGHS IN THE LOW TO MID 70S. BACKDOOR COLD FRONT TO MOVE FROM THE GREAT LAKES REGION THROUGH IL EARLY NEXT WEEK...COOLING TEMPS MONDAY ESPECIALLY NE AREAS BUT DRY CONDITIONS EXPECTED SUNDAY THROUGH TUE. LONG TERM...TUESDAY THROUGH FRIDAY A PROGRESSIVE NORTHERN STREAM WEATHER SYSTEM TRACKING EAST ALONG THE US/CANADIAN BORDER TO PUSH A COLD FRONT THROUGH IL TUE NIGHT AND THEN STALL OUT NEAR THE OHIO RIVER WED BEFORE LIFTING BACK NORTH LATER NEXT WEEK. THIS TO BRING CHANCES OF SHOWERS/THUNDERSTORMS BY TUE NIGHT AND MAINLY IN SE IL WED AND THEN HAVE SLIGHT CHANCES OF CONVECTION LATE NEXT WORK WEEK WITH FRONT LIFTING BACK NORTH. TEMPS OVERALL TO REMAIN ABOVE NORMAL AND NO FROST OR FREEZE EXPECTED THROUGH NEXT WEEK. HUETTL && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1215 AM CDT FRI MAR 23 2012 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TODAY/... BIGGEST FOCUS TODAY WILL BE ON FOG THIS MORNING...AND THEN CHANCES FOR SHOWERS ACROSS THE SOUTHERN CWA. FOG HAS DEVELOPED ACROSS MUCH OF THE CWA...MAINLY NORTH AND EAST OF A LINE FROM OTTUMWA...TO DES MOINES...TO CARROLL. FOG EXPECTED TO PERSIST ACROSS THE AREA INTO THE MID MORNING HOURS...WITH WINDS EXPECTED TO REMAIN LIGHT AND CONTINUE TO HAVE MOISTURE NEAR SURFACE CONDITIONS DUE TO RESIDUAL MOISTURE FROM RAINFALL OVER THE PAST FEW DAYS. MAJORITY OF VSBYS RANGING FROM NEAR ZERO TO AROUND ONE QUARTER MILE AND ARE ONLY EXPECTED TO WORSEN THROUGH SUNRISE...WITH THE HRRR KEEPING VSBYS AT A QUARTER MILE OR BELOW THROUGH 15Z. THEREFORE HAVE OPTED TO ISSUE A DENSE FOG ADVISORY FOR MUCH OF THE CWA THROUGH 15Z. FOG SHOULD THEN LIFT INTO SOME LOW STRATUS AND THEN BREAK UP SOME BY LATE MORNING INTO THE EARLY AFTERNOON HOURS. WITH THE UPPER LOW CHURNING TO THE SOUTH OF THE CWA...AND CONTINUED CYCLONIC FLOW OVER THE STATE...DO NOT EXPECT SKIES TO CLEAR COMPLETELY TODAY...WITH SOME SHOWERS POSSIBLE ACROSS SOUTHERN CWA THROUGHOUT THE DAY AS BANDS OF LIGHT SHOWERS CONTINUE TO ROTATE NORTHWARD FROM MISSOURI AROUND MAIN LOW TO THE SOUTH OF THE CWA. ANY PRECIP ROTATING BACK INTO THE AREA ACROSS NORTHEASTERN CWA APPEARS TO HOLD OFF UNTIL AFTER 00Z. WITH H85 TEMPERATURES AROUND +9C...A COOLER START TO THE DAY...AND CLOUD COVER/LINGERING FOG HAVE TEMPS IN THE UPPER 60S TO AROUND 70. .LONG TERM /TONIGHT THROUGH THURSDAY/... THOUGH THE UPPER LOW CENTER IS CURRENTLY OVER FAR SOUTHEAST KANSAS...THE STRONGEST PV ANOMALY ASSOCIATED WITH THE SYSTEM IS ROUNDING THROUGH CNTRL ARKANSAS. THIS WILL HELP KEEP THE UPPER LOW ON A MORE SOUTHERLY TRACK BY THIS EVENING AS IT TRACKS INTO THE LOWER OHIO VALLEY. ONE FINAL PIECE OF ENERGY WILL WRAP AROUND THE SYSTEM AND INTO EASTERN AS THE SYSTEM DEPARTS TONIGHT. THIS WILL BRING ONE LAST CHANCE FOR SHOWERS EAST OF INTERSTATE 35. THE AREA WILL QUICKLY TRANSITION OUT OF CYCLONIC FLOW ON SATURDAY WITH RIDGING BUILDING IN FROM THE WEST. DESPITE NW FLOW...SOME SFC WARM ADVECTION WILL BE TAKING PLACE. THE NW FLOW WILL ALSO AID DESCENT MIXING AND THERE SHOULD BE AN ABUNDANCE OF SUNSHINE CENTRAL AND WEST WITH A FEW CLOUDS LINGERING OVER THE EAST. A WEAK FRONTAL BOUNDARY WILL REACH THE NORTHERN THIRD OF THE STATE SATURDAY NIGHT AND SUNDAY THOUGH THE GREATEST IMPACTS WILL MOVE THROUGH PORTIONS OF MINNESOTA AND WISCONSIN. SHOULD BE A PLEASANT DAY OVERALL WITH HIGHS IN THE 60S AND 70S WITH LIGHT WINDS. THE MONDAY FORECAST CONTINUES TO BECOME MORE COMPLEX. THE AFOREMENTIONED COLD ADVECTION THROUGH WISCONSIN SUNDAY WILL SHIFT WEST AS A BACK DOOR COLD FRONT OFF LAKE MICHIGAN SUNDAY NIGHT AND MONDAY. WARM ADVECTION WILL BE LIFTING INTO WESTERN IOWA BY MONDAY MORNING HOWEVER ITS EASTWARD ADVANCE WILL LIKELY BE OVERCOME BY THE COOLER AND MORE DENSE AIR FILTERING IN FROM THE EAST. HIGH TEMPERATURES AT THIS POINT COULD BE TOO HIGH BY SEVERAL DEGREES IF THE THIS BOUNDARY COMES IN AS STRONG AS SUGGESTED. DESPITE THIS...MID LEVEL WARM ADVECTION WILL CONTINUE TO OVERSPREAD THE AREA MONDAY WITH SOME INSTABILITY DEVELOPING AHEAD OF THE LOW LEVEL JET AND STRONG THETA E ADVECTION. BEST POTENTIAL FOR THUNDERSTORMS WOULD BE OVER THE NORTH. ANY THUNDER AT THIS TIME LIKELY WILL BE ELEVATED THOUGH A MARGINAL SEVERE STORM WOULD BE POSSIBLE. BOWLING BALL UPPER LOW LIFTING INTO THE NORTHERN PLAINS ON TUESDAY COULD PRODUCE SOME INTERESTING WEATHER TUESDAY PENDING EXACT TIMING AND PLACEMENT OF THE SYSTEM. COOLER AIR WILL SINK IN BEHIND THE SYSTEM THOUGH AGAIN THE GREATEST IMPACT WILL BE TO THE NORTHEAST. TEMPERATURES WILL REMAIN WELL ABOVE SEASONAL VALUES WITH LOW POTENTIAL FOR PRECIPITATION WEDNESDAY AND THURSDAY. && .AVIATION...23/18Z EARLY MORNING FOG HAS LIFTED...WITH A FEW SITES...KOTM/KFOD STILL EXPERIENCING LOW MVFR CEILINGS. THESE WILL CONTINUE TO LIFT THROUGH THE EARLY PERIOD...WITH VFR CEILINGS THROUGH 06Z. FOG IS POSSIBLE AGAIN AT SITES NEAR 12Z...AND HAVE TRENDED VISIBILITIES DOWN. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE && $$ SHORT TERM...BEERENDS LONG TERM...DONAVON AVIATION...AWB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
717 AM CDT FRI MAR 23 2012 .UPDATE... SUNRISE HAS ALLOWED VISIBILITIES TO SUDDENLY TANK. WEB CAMS SHOW THE FOG IS NOT CONTINUOUS WITH AREAS OF GOOD VISIBILITY AND FOG BANKS IN OTHER AREAS. SO...WILL ISSUE A DENSE FOG ADVISORY AND WORD IT ACCORDINGLY. ..08.. && .PREV DISCUSSION... /ISSUED 653 AM CDT FRI MAR 23 2012/ UPDATE... MONITORING THE FOG FOR THE PAST FEW HOURS. SFC OBS CONTINUE TO SUGGEST IT IS PATCHY WITH SOME AREAS HAVING GOOD VISIBILITY. WEB CAMS THAT HAVE ENOUGH LIGHT OR BACKGROUND LIGHT AVAILABLE SUGGEST THE FOG IS NOT OVERLY THICK IN VERTICAL DEPTH OR WIDESPREAD. THE IMPENDING SUNRISE WILL PROVIDE MORE LIGHT OVER THE NEXT 30 MINUTES TO GIVE MORE CLARITY ON THE WEB CAMS. BASED ON THIS DATA AND RUC TRENDS IT WOULD APPEAR THAT THE FOG IS IN LOW LYING AREAS AND SOME RIVER VALLEYS. CURRENT PLAN IS TO CONTINUE WITH THE SPS UNLESS NEW DATA IN THE NEXT 30 MINUTES SUGGEST OTHERWISE. .08.. AVIATION... VFR TO VLIFR CONDITIONS WILL BE SEEN STARTING AT SUNRISE WITH CONDITIONS IMPROVING TO MVFR OR VFR BY 18Z/23Z. TRENDS WITH THE RUC MODEL POINT TO AFTERNOON CONVECTION DEVELOPING WITH POTENTIAL TSRA IMPACTS AT KMLI/KBRL. KCID/KDBQ MY SEE VCSH. AFT 06Z/24 CONDITIONS ARE EXPECTED TO DETERIORATE TO MINIMALLY MVFR WITH THE POTENTIAL FOR IFR/LIFR CONDITIONS. .08.. PREV DISCUSSION... /ISSUED 325 AM CDT FRI MAR 23 2012/ SYNOPSIS... 06Z SFC ANALYSIS HAS NUMEROUS WEAK LOWS ACROSS THE MIDWEST ALONG WITH ASSOCIATED TROFS. A WEAK LOW WAS NORTHEAST OF KDSM WITH A TROF RUNNING SOUTHEAST TO KEVV. ANOTHER TROF RAN FROM CENTRAL INDIANA NORTHWEST INTO SOUTHERN MINNESOTA. THE OCCLUDED LOW ASSOCIATED WITH THE UPPER LOW WAS NEAR KCNU WITH TROFS RADIATING OUT FROM IT. DEW POINTS WERE GENERALLY IN THE 40S AND 50S ACROSS THE MIDWEST. RADAR TRENDS SHOW THE MAIN PRECIP GENERALLY NORTH OF A LINE FROM KRST TO KVYS WHICH WAS ASSOCIATED WITH A VORT MAX ROTATING AROUND THE UPPER LOW. SHORT TERM...TODAY AND TONIGHT... A VERY INTERESTING FCST WITH INTERACTIONS BOTH UP AND DOWN ON VARIOUS SCALES ALONG WITH NONLINEAR PROCESSES. THE RUC WAS VERY USEFUL IN ESTABLISHING OVERALL NEAR TERM TRENDS. THE MCS AND LIFT TOOLS ALONG WITH THE HEAVY RAIN TOOL DO A NICE JOB OF DEPICTING THE CURRENT PRECIPITATION ACROSS THE AREA. THE PRECIP IS JUST EAST OF THE MAIN THETA E GRADIENT AND THE RUC HAS THIS GRADIENT SLOWLY MOVING TO THE NORTH AND EAST THROUGH 12Z. THUS THE CURRENT PRECIP WILL SLOWLY MOVE OUT OF THE AREA. THE PARTIAL CLEARING THAT HAS OCCURRED IN THE DIRTY DRY SLOT HAS ALLOWED FOG TO DEVELOP WITH IT LOCALLY THICK IN AN AREA OF WEAK CONVERGENCE ACROSS SOUTHEAST IOWA. A FEW GROUND TRUTH REPORTS INDICATE IT IS VERY SHALLOW. SO WILL CONTINUE TO MONITOR FOR TRENDS BUT WILL HIGHLIGHT FOG THREAT WITH ANOTHER SPS. ANY PRECIPITATION SHOULD BE CONFINED TO THE FAR NORTHEAST/EAST PARTS OF THE CWFA THROUGH MID MORNING BEFORE DIFFERENTIAL HEATING BEGINS TO PRODUCE SOME ISOLD SHRA ACROSS THE REMAINDER OF THE AREA. LIFT AND HEAVY RAIN TOOLS SUGGEST A CONSIDERABLE AMOUNT OF NEW CONVECTION SHOULD BE ACROSS NORTHEAST ILLINOIS AT MID DAY WITH ANOTHER VORT MAX. LIFT TOOL HAS A THETA E GRADIENT ACROSS ROUGHLY THE SOUTHEAST HALF OF THE CWFA DURING THE AFTERNOON WITH CONVERGENCE INCREASING. THUS SHOWERS WITH TSRA WILL BE MOST PREVALENT ACROSS ROUGHLY THE SOUTHERN HALF OF THE CWFA. CONVECTION WILL CONTINUE INTO THE EVENING HOURS WITH IT MOST NUMEROUS ACROSS THE SOUTHERN HALF OF THE CWFA. SUNSET WILL ALLOW THE ATMOSPHERE TO RE-STABILIZE SO CONVECTION WILL DIMINISH DURING THE EVENING. MCS AND LIFT TOOLS SUGGEST CONVECTION MAY PERSIST OR EVEN RE-DEVELOP AFTER MIDNIGHT ACROSS THE NORTHWEST THIRD TO HALF OF THE CWFA WITH CONVERGENCE INCREASING THERE AS ANOTHER VORT MAX ROTATES AROUND THE UPPER LOW. ..08.. LONG TERM...SATURDAY THROUGH NEXT THURSDAY... MOSTLY DRY TO DRY WITH TEMPERATURES STILL ABOVE NORMAL BY AT LEAST SEVERAL DEGREES IF NOT MORE ALL DAYS....THOUGH NOT RECORD WARMTH. OVERALL...INITIALIZATION GOOD WITH UPSTREAM ENERGY AND VERIFICATION AND RUN TO RUN CONTINUITY SUPPORTING A 50/50 BLEND OF GFS/HI-RES ECMWF. LIMITED SENSIBLE IMPACTS WITH SOME LIGHT TO LOCALLY MODERATE RAIN AMOUNTS POSSIBLY WITH BACKDOOR COLD FRONT MONDAY INTO TUESDAY AHEAD OF NEXT SHORT WAVE. PERSISTENCE SUGGEST GUIDANCE TEMPS MAY STILL BE A FEW DEGREES TOO COOL FOR LATER SHIFTS TO CONSIDER MOST DAYS EXCEPT MONDAY WHEN BACKDOOR FRONT MAY BE COLDER WITH GOOD ADVECTION FROM NE WINDS OFF LAKE MICHIGAN. SATURDAY...KEPT LOW POPS WITH CONVECTIVE TEMPERATURE REACHED FOR MOSTLY PM POPCORN -SHRA. OTHERWISE...PARTLY SUNNY AND MILD WITH HIGHS MAINLY 70 TO 75 DEGREES WITH LIGHT WINDS. SATURDAY NIGHT... CLEARING AND A BIT COLDER WITH MINS AROUND 50 DEGREES BUT LIGHT WIND SUGGEST LATER SHIFTS MAY NEED TO TRIM AT LEAST A FEW DEGREES WITH GOOD BL DECOUPLING. SUNDAY...ANOTHER SPLENDID LATE MARCH DAY AHEAD OF BACKDOOR COLD FRONT WITH HIGHS WELL INTO THE 70S AND LIGHT NORTH WINDS. SUNDAY NIGHT...BACKDOOR ARRIVES BY LATE EVENING WITH NE WINDS OF 10-20+ MPH SUGGESTED. WENT WITH MINS OF LOWER 40S NE TO LOWER 50S SW BUT LATER SHIFTS MAY NEED TO TRIM AT LEAST A COUPLE MORE DEGREES MOST LOCATIONS. WITH OUR EXTENDED MILD WEATHER...THIS WILL FEEL COLDER THAN ONE WOULD EXPECT FOR LATE MARCH TO MANY. MONDAY THROUGH TUESDAY...LOCAL TECHNIQUES SUGGEST NE SECTIONS MAY STRUGGLE WITH IDEAL FETCH OFF LAKE MICHIGAN IN NE 1/2 OF AREA TO REACH THE MIDDLE 50S WITH GUSTY NE TO E WINDS OF 15-25+ MPH. LOW CLOUDS ALSO MAY RESULT IN GREATER IMPACT OF A COOL DAY. NEXT SHORT WAVE MAY SPAWN LIGHT RAIN AND RAIN SHOWERS MONDAY NIGHT INTO TUESDAY. THE STRENGTH OF FORCING SHOULD BE BETTER ASCERTAINED NEXT 12-24 HOURS. TUESDAY WARM FRONT SHOULD PASS BY MID DAY FOR TEMPERATURES BACK INTO THE 70S AND MINS TUESDAY NIGHT UPPER 40S TO LOWER 50S WITH -SHRA/-TSRA ENDING PROBABLY BY MIDNIGHT WITH PASSAGE OF COLD FRONT. ANY STORMS ATTM PROBABLY NON-SEVERE DUE TO LIMITED FORCING AND INSTABILITY. WEDNESDAY AND THURSDAY...MAINLY DRY WITH WEAK HIGH PRESSURE AND ONLY A BIT COOLER WITH HIGHS IN THE 60S AND MINS IN THE 40S. THIS IS STILL 10 PLUS DEGREES ABOVE NORMAL AS OUR REMARKABLE EXTENDED PERIOD OF MARCH WARM SPELL CONTINUES. ..NICHOLS.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BENTON- BUCHANAN-CEDAR-DES MOINES-HENRY IA-IOWA-JEFFERSON-JOHNSON- KEOKUK-LEE-LINN-LOUISA-MUSCATINE-SCOTT-VAN BUREN-WASHINGTON. IL...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR HANCOCK- HENDERSON-HENRY IL-MCDONOUGH-MERCER-ROCK ISLAND-WARREN. MO...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR CLARK- SCOTLAND. && $$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
655 AM CDT FRI MAR 23 2012 .SHORT TERM /TODAY/... BIGGEST FOCUS TODAY WILL BE ON FOG THIS MORNING...AND THEN CHANCES FOR SHOWERS ACROSS THE SOUTHERN CWA. FOG HAS DEVELOPED ACROSS MUCH OF THE CWA...MAINLY NORTH AND EAST OF A LINE FROM OTTUMWA...TO DES MOINES...TO CARROLL. FOG EXPECTED TO PERSIST ACROSS THE AREA INTO THE MID MORNING HOURS...WITH WINDS EXPECTED TO REMAIN LIGHT AND CONTINUE TO HAVE MOISTURE NEAR SURFACE CONDITIONS DUE TO RESIDUAL MOISTURE FROM RAINFALL OVER THE PAST FEW DAYS. MAJORITY OF VSBYS RANGING FROM NEAR ZERO TO AROUND ONE QUARTER MILE AND ARE ONLY EXPECTED TO WORSEN THROUGH SUNRISE...WITH THE HRRR KEEPING VSBYS AT A QUARTER MILE OR BELOW THROUGH 15Z. THEREFORE HAVE OPTED TO ISSUE A DENSE FOG ADVISORY FOR MUCH OF THE CWA THROUGH 15Z. FOG SHOULD THEN LIFT INTO SOME LOW STRATUS AND THEN BREAK UP SOME BY LATE MORNING INTO THE EARLY AFTERNOON HOURS. WITH THE UPPER LOW CHURNING TO THE SOUTH OF THE CWA...AND CONTINUED CYCLONIC FLOW OVER THE STATE...DO NOT EXPECT SKIES TO CLEAR COMPLETELY TODAY...WITH SOME SHOWERS POSSIBLE ACROSS SOUTHERN CWA THROUGHOUT THE DAY AS BANDS OF LIGHT SHOWERS CONTINUE TO ROTATE NORTHWARD FROM MISSOURI AROUND MAIN LOW TO THE SOUTH OF THE CWA. ANY PRECIP ROTATING BACK INTO THE AREA ACROSS NORTHEASTERN CWA APPEARS TO HOLD OFF UNTIL AFTER 00Z. WITH H85 TEMPERATURES AROUND +9C...A COOLER START TO THE DAY...AND CLOUD COVER/LINGERING FOG HAVE TEMPS IN THE UPPER 60S TO AROUND 70. .LONG TERM /TONIGHT THROUGH THURSDAY/... THOUGH THE UPPER LOW CENTER IS CURRENTLY OVER FAR SOUTHEAST KANSAS...THE STRONGEST PV ANOMALY ASSOCIATED WITH THE SYSTEM IS ROUNDING THROUGH CNTRL ARKANSAS. THIS WILL HELP KEEP THE UPPER LOW ON A MORE SOUTHERLY TRACK BY THIS EVENING AS IT TRACKS INTO THE LOWER OHIO VALLEY. ONE FINAL PIECE OF ENERGY WILL WRAP AROUND THE SYSTEM AND INTO EASTERN AS THE SYSTEM DEPARTS TONIGHT. THIS WILL BRING ONE LAST CHANCE FOR SHOWERS EAST OF INTERSTATE 35. THE AREA WILL QUICKLY TRANSITION OUT OF CYCLONIC FLOW ON SATURDAY WITH RIDGING BUILDING IN FROM THE WEST. DESPITE NW FLOW...SOME SFC WARM ADVECTION WILL BE TAKING PLACE. THE NW FLOW WILL ALSO AID DESCENT MIXING AND THERE SHOULD BE AN ABUNDANCE OF SUNSHINE CENTRAL AND WEST WITH A FEW CLOUDS LINGERING OVER THE EAST. A WEAK FRONTAL BOUNDARY WILL REACH THE NORTHERN THIRD OF THE STATE SATURDAY NIGHT AND SUNDAY THOUGH THE GREATEST IMPACTS WILL MOVE THROUGH PORTIONS OF MINNESOTA AND WISCONSIN. SHOULD BE A PLEASANT DAY OVERALL WITH HIGHS IN THE 60S AND 70S WITH LIGHT WINDS. THE MONDAY FORECAST CONTINUES TO BECOME MORE COMPLEX. THE AFOREMENTIONED COLD ADVECTION THROUGH WISCONSIN SUNDAY WILL SHIFT WEST AS A BACK DOOR COLD FRONT OFF LAKE MICHIGAN SUNDAY NIGHT AND MONDAY. WARM ADVECTION WILL BE LIFTING INTO WESTERN IOWA BY MONDAY MORNING HOWEVER ITS EASTWARD ADVANCE WILL LIKELY BE OVERCOME BY THE COOLER AND MORE DENSE AIR FILTERING IN FROM THE EAST. HIGH TEMPERATURES AT THIS POINT COULD BE TOO HIGH BY SEVERAL DEGREES IF THE THIS BOUNDARY COMES IN AS STRONG AS SUGGESTED. DESPITE THIS...MID LEVEL WARM ADVECTION WILL CONTINUE TO OVERSPREAD THE AREA MONDAY WITH SOME INSTABILITY DEVELOPING AHEAD OF THE LOW LEVEL JET AND STRONG THETA E ADVECTION. BEST POTENTIAL FOR THUNDERSTORMS WOULD BE OVER THE NORTH. ANY THUNDER AT THIS TIME LIKELY WILL BE ELEVATED THOUGH A MARGINAL SEVERE STORM WOULD BE POSSIBLE. BOWLING BALL UPPER LOW LIFTING INTO THE NORTHERN PLAINS ON TUESDAY COULD PRODUCE SOME INTERESTING WEATHER TUESDAY PENDING EXACT TIMING AND PLACEMENT OF THE SYSTEM. COOLER AIR WILL SINK IN BEHIND THE SYSTEM THOUGH AGAIN THE GREATEST IMPACT WILL BE TO THE NORTHEAST. TEMPERATURES WILL REMAIN WELL ABOVE SEASONAL VALUES WITH LOW POTENTIAL FOR PRECIPITATION WEDNESDAY AND THURSDAY. && .AVIATION...23/12Z LIFR VSBYS/CIGS TO LIFT BY MID MORNING ACROSS KFOD...KALO...AND KOTM. OTHERWISE MAINLY VFR CONDITIONS EXPECTED WITH A MID LEVEL CLOUD DECK EXPECTED THROUGH THE PERIOD. FOG DEVELOPMENT POSSIBLE AT KALO AND KMCW LATE TONIGHT. WINDS TO BE OUT OF THE NORTH TO NORTHWEST AND LIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BLACK HAWK- BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CERRO GORDO-EMMET-FRANKLIN- GREENE-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH- MARSHALL-PALO ALTO-POCAHONTAS-POWESHIEK-SAC-STORY-TAMA-WEBSTER- WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...BEERENDS LONG TERM...DONAVON AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
653 AM CDT FRI MAR 23 2012 .UPDATE... MONITORING THE FOG FOR THE PAST FEW HOURS. SFC OBS CONTINUE TO SUGGEST IT IS PATCHY WITH SOME AREAS HAVING GOOD VISIBILITY. WEB CAMS THAT HAVE ENOUGH LIGHT OR BACKGROUND LIGHT AVAILABLE SUGGEST THE FOG IS NOT OVERLY THICK IN VERTICAL DEPTH OR WIDESPREAD. THE IMPENDING SUNRISE WILL PROVIDE MORE LIGHT OVER THE NEXT 30 MINUTES TO GIVE MORE CLARITY ON THE WEB CAMS. BASED ON THIS DATA AND RUC TRENDS IT WOULD APPEAR THAT THE FOG IS IN LOW LYING AREAS AND SOME RIVER VALLEYS. CURRENT PLAN IS TO CONTINUE WITH THE SPS UNLESS NEW DATA IN THE NEXT 30 MINUTES SUGGEST OTHERWISE. ..08.. && .AVIATION... VFR TO VLIFR CONDITIONS WILL BE SEEN STARTING AT SUNRISE WITH CONDITIONS IMPROVING TO MVFR OR VFR BY 18Z/23Z. TRENDS WITH THE RUC MODEL POINT TO AFTERNOON CONVECTION DEVELOPING WITH POTENTIAL TSRA IMPACTS AT KMLI/KBRL. KCID/KDBQ MY SEE VCSH. AFT 06Z/24 CONDITIONS ARE EXPECTED TO DETERIORATE TO MINIMALLY MVFR WITH THE POTENTIAL FOR IFR/LIFR CONDITIONS. ..08.. && .PREV DISCUSSION... /ISSUED 325 AM CDT FRI MAR 23 2012/ SYNOPSIS... 06Z SFC ANALYSIS HAS NUMEROUS WEAK LOWS ACROSS THE MIDWEST ALONG WITH ASSOCIATED TROFS. A WEAK LOW WAS NORTHEAST OF KDSM WITH A TROF RUNNING SOUTHEAST TO KEVV. ANOTHER TROF RAN FROM CENTRAL INDIANA NORTHWEST INTO SOUTHERN MINNESOTA. THE OCCLUDED LOW ASSOCIATED WITH THE UPPER LOW WAS NEAR KCNU WITH TROFS RADIATING OUT FROM IT. DEW POINTS WERE GENERALLY IN THE 40S AND 50S ACROSS THE MIDWEST. RADAR TRENDS SHOW THE MAIN PRECIP GENERALLY NORTH OF A LINE FROM KRST TO KVYS WHICH WAS ASSOCIATED WITH A VORT MAX ROTATING AROUND THE UPPER LOW. SHORT TERM...TODAY AND TONIGHT... A VERY INTERESTING FCST WITH INTERACTIONS BOTH UP AND DOWN ON VARIOUS SCALES ALONG WITH NONLINEAR PROCESSES. THE RUC WAS VERY USEFUL IN ESTABLISHING OVERALL NEAR TERM TRENDS. THE MCS AND LIFT TOOLS ALONG WITH THE HEAVY RAIN TOOL DO A NICE JOB OF DEPICTING THE CURRENT PRECIPITATION ACROSS THE AREA. THE PRECIP IS JUST EAST OF THE MAIN THETA E GRADIENT AND THE RUC HAS THIS GRADIENT SLOWLY MOVING TO THE NORTH AND EAST THROUGH 12Z. THUS THE CURRENT PRECIP WILL SLOWLY MOVE OUT OF THE AREA. THE PARTIAL CLEARING THAT HAS OCCURRED IN THE DIRTY DRY SLOT HAS ALLOWED FOG TO DEVELOP WITH IT LOCALLY THICK IN AN AREA OF WEAK CONVERGENCE ACROSS SOUTHEAST IOWA. A FEW GROUND TRUTH REPORTS INDICATE IT IS VERY SHALLOW. SO WILL CONTINUE TO MONITOR FOR TRENDS BUT WILL HIGHLIGHT FOG THREAT WITH ANOTHER SPS. ANY PRECIPITATION SHOULD BE CONFINED TO THE FAR NORTHEAST/EAST PARTS OF THE CWFA THROUGH MID MORNING BEFORE DIFFERENTIAL HEATING BEGINS TO PRODUCE SOME ISOLD SHRA ACROSS THE REMAINDER OF THE AREA. LIFT AND HEAVY RAIN TOOLS SUGGEST A CONSIDERABLE AMOUNT OF NEW CONVECTION SHOULD BE ACROSS NORTHEAST ILLINOIS AT MID DAY WITH ANOTHER VORT MAX. LIFT TOOL HAS A THETA E GRADIENT ACROSS ROUGHLY THE SOUTHEAST HALF OF THE CWFA DURING THE AFTERNOON WITH CONVERGENCE INCREASING. THUS SHOWERS WITH TSRA WILL BE MOST PREVALENT ACROSS ROUGHLY THE SOUTHERN HALF OF THE CWFA. CONVECTION WILL CONTINUE INTO THE EVENING HOURS WITH IT MOST NUMEROUS ACROSS THE SOUTHERN HALF OF THE CWFA. SUNSET WILL ALLOW THE ATMOSPHERE TO RE-STABILIZE SO CONVECTION WILL DIMINISH DURING THE EVENING. MCS AND LIFT TOOLS SUGGEST CONVECTION MAY PERSIST OR EVEN RE-DEVELOP AFTER MIDNIGHT ACROSS THE NORTHWEST THIRD TO HALF OF THE CWFA WITH CONVERGENCE INCREASING THERE AS ANOTHER VORT MAX ROTATES AROUND THE UPPER LOW. ..08.. LONG TERM...SATURDAY THROUGH NEXT THURSDAY... MOSTLY DRY TO DRY WITH TEMPERATURES STILL ABOVE NORMAL BY AT LEAST SEVERAL DEGREES IF NOT MORE ALL DAYS....THOUGH NOT RECORD WARMTH. OVERALL...INITIALIZATION GOOD WITH UPSTREAM ENERGY AND VERIFICATION AND RUN TO RUN CONTINUITY SUPPORTING A 50/50 BLEND OF GFS/HI-RES ECMWF. LIMITED SENSIBLE IMPACTS WITH SOME LIGHT TO LOCALLY MODERATE RAIN AMOUNTS POSSIBLY WITH BACKDOOR COLD FRONT MONDAY INTO TUESDAY AHEAD OF NEXT SHORT WAVE. PERSISTENCE SUGGEST GUIDANCE TEMPS MAY STILL BE A FEW DEGREES TOO COOL FOR LATER SHIFTS TO CONSIDER MOST DAYS EXCEPT MONDAY WHEN BACKDOOR FRONT MAY BE COLDER WITH GOOD ADVECTION FROM NE WINDS OFF LAKE MICHIGAN. SATURDAY...KEPT LOW POPS WITH CONVECTIVE TEMPERATURE REACHED FOR MOSTLY PM POPCORN -SHRA. OTHERWISE...PARTLY SUNNY AND MILD WITH HIGHS MAINLY 70 TO 75 DEGREES WITH LIGHT WINDS. SATURDAY NIGHT... CLEARING AND A BIT COLDER WITH MINS AROUND 50 DEGREES BUT LIGHT WIND SUGGEST LATER SHIFTS MAY NEED TO TRIM AT LEAST A FEW DEGREES WITH GOOD BL DECOUPLING. SUNDAY...ANOTHER SPLENDID LATE MARCH DAY AHEAD OF BACKDOOR COLD FRONT WITH HIGHS WELL INTO THE 70S AND LIGHT NORTH WINDS. SUNDAY NIGHT...BACKDOOR ARRIVES BY LATE EVENING WITH NE WINDS OF 10-20+ MPH SUGGESTED. WENT WITH MINS OF LOWER 40S NE TO LOWER 50S SW BUT LATER SHIFTS MAY NEED TO TRIM AT LEAST A COUPLE MORE DEGREES MOST LOCATIONS. WITH OUR EXTENDED MILD WEATHER...THIS WILL FEEL COLDER THAN ONE WOULD EXPECT FOR LATE MARCH TO MANY. MONDAY THROUGH TUESDAY...LOCAL TECHNIQUES SUGGEST NE SECTIONS MAY STRUGGLE WITH IDEAL FETCH OFF LAKE MICHIGAN IN NE 1/2 OF AREA TO REACH THE MIDDLE 50S WITH GUSTY NE TO E WINDS OF 15-25+ MPH. LOW CLOUDS ALSO MAY RESULT IN GREATER IMPACT OF A COOL DAY. NEXT SHORT WAVE MAY SPAWN LIGHT RAIN AND RAIN SHOWERS MONDAY NIGHT INTO TUESDAY. THE STRENGTH OF FORCING SHOULD BE BETTER ASCERTAINED NEXT 12-24 HOURS. TUESDAY WARM FRONT SHOULD PASS BY MID DAY FOR TEMPERATURES BACK INTO THE 70S AND MINS TUESDAY NIGHT UPPER 40S TO LOWER 50S WITH -SHRA/-TSRA ENDING PROBABLY BY MIDNIGHT WITH PASSAGE OF COLD FRONT. ANY STORMS ATTM PROBABLY NON-SEVERE DUE TO LIMITED FORCING AND INSTABILITY. WEDNESDAY AND THURSDAY...MAINLY DRY WITH WEAK HIGH PRESSURE AND ONLY A BIT COOLER WITH HIGHS IN THE 60S AND MINS IN THE 40S. THIS IS STILL 10 PLUS DEGREES ABOVE NORMAL AS OUR REMARKABLE EXTENDED PERIOD OF MARCH WARM SPELL CONTINUES. ..NICHOLS.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
351 AM CDT FRI MAR 23 2012 .SHORT TERM /TODAY/... BIGGEST FOCUS TODAY WILL BE ON FOG THIS MORNING...AND THEN CHANCES FOR SHOWERS ACROSS THE SOUTHERN CWA. FOG HAS DEVELOPED ACROSS MUCH OF THE CWA...MAINLY NORTH AND EAST OF A LINE FROM OTTUMWA...TO DES MOINES...TO CARROLL. FOG EXPECTED TO PERSIST ACROSS THE AREA INTO THE MID MORNING HOURS...WITH WINDS EXPECTED TO REMAIN LIGHT AND CONTINUE TO HAVE MOISTURE NEAR SURFACE CONDITIONS DUE TO RESIDUAL MOISTURE FROM RAINFALL OVER THE PAST FEW DAYS. MAJORITY OF VSBYS RANGING FROM NEAR ZERO TO AROUND ONE QUARTER MILE AND ARE ONLY EXPECTED TO WORSEN THROUGH SUNRISE...WITH THE HRRR KEEPING VSBYS AT A QUARTER MILE OR BELOW THROUGH 15Z. THEREFORE HAVE OPTED TO ISSUE A DENSE FOG ADVISORY FOR MUCH OF THE CWA THROUGH 15Z. FOG SHOULD THEN LIFT INTO SOME LOW STRATUS AND THEN BREAK UP SOME BY LATE MORNING INTO THE EARLY AFTERNOON HOURS. WITH THE UPPER LOW CHURNING TO THE SOUTH OF THE CWA...AND CONTINUED CYCLONIC FLOW OVER THE STATE...DO NOT EXPECT SKIES TO CLEAR COMPLETELY TODAY...WITH SOME SHOWERS POSSIBLE ACROSS SOUTHERN CWA THROUGHOUT THE DAY AS BANDS OF LIGHT SHOWERS CONTINUE TO ROTATE NORTHWARD FROM MISSOURI AROUND MAIN LOW TO THE SOUTH OF THE CWA. ANY PRECIP ROTATING BACK INTO THE AREA ACROSS NORTHEASTERN CWA APPEARS TO HOLD OFF UNTIL AFTER 00Z. WITH H85 TEMPERATURES AROUND +9C...A COOLER START TO THE DAY...AND CLOUD COVER/LINGERING FOG HAVE TEMPS IN THE UPPER 60S TO AROUND 70. .LONG TERM /TONIGHT THROUGH THURSDAY/... THOUGH THE UPPER LOW CENTER IS CURRENTLY OVER FAR SOUTHEAST KANSAS...THE STRONGEST PV ANOMALY ASSOCIATED WITH THE SYSTEM IS ROUNDING THROUGH CNTRL ARKANSAS. THIS WILL HELP KEEP THE UPPER LOW ON A MORE SOUTHERLY TRACK BY THIS EVENING AS IT TRACKS INTO THE LOWER OHIO VALLEY. ONE FINAL PIECE OF ENERGY WILL WRAP AROUND THE SYSTEM AND INTO EASTERN AS THE SYSTEM DEPARTS TONIGHT. THIS WILL BRING ONE LAST CHANCE FOR SHOWERS EAST OF INTERSTATE 35. THE AREA WILL QUICKLY TRANSITION OUT OF CYCLONIC FLOW ON SATURDAY WITH RIDGING BUILDING IN FROM THE WEST. DESPITE NW FLOW...SOME SFC WARM ADVECTION WILL BE TAKING PLACE. THE NW FLOW WILL ALSO AID DESCENT MIXING AND THERE SHOULD BE AN ABUNDANCE OF SUNSHINE CENTRAL AND WEST WITH A FEW CLOUDS LINGERING OVER THE EAST. A WEAK FRONTAL BOUNDARY WILL REACH THE NORTHERN THIRD OF THE STATE SATURDAY NIGHT AND SUNDAY THOUGH THE GREATEST IMPACTS WILL MOVE THROUGH PORTIONS OF MINNESOTA AND WISCONSIN. SHOULD BE A PLEASANT DAY OVERALL WITH HIGHS IN THE 60S AND 70S WITH LIGHT WINDS. THE MONDAY FORECAST CONTINUES TO BECOME MORE COMPLEX. THE AFOREMENTIONED COLD ADVECTION THROUGH WISCONSIN SUNDAY WILL SHIFT WEST AS A BACK DOOR COLD FRONT OFF LAKE MICHIGAN SUNDAY NIGHT AND MONDAY. WARM ADVECTION WILL BE LIFTING INTO WESTERN IOWA BY MONDAY MORNING HOWEVER ITS EASTWARD ADVANCE WILL LIKELY BE OVERCOME BY THE COOLER AND MORE DENSE AIR FILTERING IN FROM THE EAST. HIGH TEMPERATURES AT THIS POINT COULD BE TOO HIGH BY SEVERAL DEGREES IF THE THIS BOUNDARY COMES IN AS STRONG AS SUGGESTED. DESPITE THIS...MID LEVEL WARM ADVECTION WILL CONTINUE TO OVERSPREAD THE AREA MONDAY WITH SOME INSTABILITY DEVELOPING AHEAD OF THE LOW LEVEL JET AND STRONG THETA E ADVECTION. BEST POTENTIAL FOR THUNDERSTORMS WOULD BE OVER THE NORTH. ANY THUNDER AT THIS TIME LIKELY WILL BE ELEVATED THOUGH A MARGINAL SEVERE STORM WOULD BE POSSIBLE. BOWLING BALL UPPER LOW LIFTING INTO THE NORTHERN PLAINS ON TUESDAY COULD PRODUCE SOME INTERESTING WEATHER TUESDAY PENDING EXACT TIMING AND PLACEMENT OF THE SYSTEM. COOLER AIR WILL SINK IN BEHIND THE SYSTEM THOUGH AGAIN THE GREATEST IMPACT WILL BE TO THE NORTHEAST. TEMPERATURES WILL REMAIN WELL ABOVE SEASONAL VALUES WITH LOW POTENTIAL FOR PRECIPITATION WEDNESDAY AND THURSDAY. && .AVIATION...23/06Z PRIMARY AVN CONCERN WILL BE FOG AND LOW STRATUS OVERNIGHT...PRODUCING LIFR/VLIFR CONDITIONS AT TIME PRIMARILY AT KFOD/KMCW/KALO. CURRENTLY VSBYS ARE BOUNCING EVERYWHERE BTWN M1/4SM AND P6SM HOWEVER SAT IMAGERY INDICATES THAT HIGH CLOUD COVERAGE IS INCREASING AND BELIEVE THIS WILL TEMPER VSBYS SOMEWHAT LATER TONIGHT...KEEPING THINGS MAINLY MVFR/IFR. CONFIDENCE IS LOW AND HAVE USED TEMPOS TO COVER SOME OF THIS UNCERTAINTY AND VSBY BOUNCING AT KFOD/KMCW. ON FRI MORNING CONDITIONS WILL IMPROVE BY LATE AM AS FOG DISSIPATES...BUT SOME MVFR CIGS AND ISOLD -SHRA WILL STILL BE POSSIBLE DURING THE DAY. && .DMX WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BLACK HAWK- BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CERRO GORDO-EMMET-FRANKLIN- GREENE-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH- MARSHALL-PALO ALTO-POCAHONTAS-POWESHIEK-SAC-STORY-TAMA-WEBSTER- WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...BEERENDS LONG TERM...DONAVON AVIATION...LEE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
325 AM CDT FRI MAR 23 2012 .SYNOPSIS... 06Z SFC ANALYSIS HAS NUMEROUS WEAK LOWS ACROSS THE MIDWEST ALONG WITH ASSOCIATED TROFS. A WEAK LOW WAS NORTHEAST OF KDSM WITH A TROF RUNNING SOUTHEAST TO KEVV. ANOTHER TROF RAN FROM CENTRAL INDIANA NORTHWEST INTO SOUTHERN MINNESOTA. THE OCCLUDED LOW ASSOCIATED WITH THE UPPER LOW WAS NEAR KCNU WITH TROFS RADIATING OUT FROM IT. DEW POINTS WERE GENERALLY IN THE 40S AND 50S ACROSS THE MIDWEST. RADAR TRENDS SHOW THE MAIN PRECIP GENERALLY NORTH OF A LINE FROM KRST TO KVYS WHICH WAS ASSOCIATED WITH A VORT MAX ROTATING AROUND THE UPPER LOW. && .SHORT TERM...TODAY AND TONIGHT... A VERY INTERESTING FCST WITH INTERACTIONS BOTH UP AND DOWN ON VARIOUS SCALES ALONG WITH NONLINEAR PROCESSES. THE RUC WAS VERY USEFUL IN ESTABLISHING OVERALL NEAR TERM TRENDS. THE MCS AND LIFT TOOLS ALONG WITH THE HEAVY RAIN TOOL DO A NICE JOB OF DEPICTING THE CURRENT PRECIPITATION ACROSS THE AREA. THE PRECIP IS JUST EAST OF THE MAIN THETA E GRADIENT AND THE RUC HAS THIS GRADIENT SLOWLY MOVING TO THE NORTH AND EAST THROUGH 12Z. THUS THE CURRENT PRECIP WILL SLOWLY MOVE OUT OF THE AREA. THE PARTIAL CLEARING THAT HAS OCCURRED IN THE DIRTY DRY SLOT HAS ALLOWED FOG TO DEVELOP WITH IT LOCALLY THICK IN AN AREA OF WEAK CONVERGENCE ACROSS SOUTHEAST IOWA. A FEW GROUND TRUTH REPORTS INDICATE IT IS VERY SHALLOW. SO WILL CONTINUE TO MONITOR FOR TRENDS BUT WILL HIGHLIGHT FOG THREAT WITH ANOTHER SPS. ANY PRECIPITATION SHOULD BE CONFINED TO THE FAR NORTHEAST/EAST PARTS OF THE CWFA THROUGH MID MORNING BEFORE DIFFERENTIAL HEATING BEGINS TO PRODUCE SOME ISOLD SHRA ACROSS THE REMAINDER OF THE AREA. LIFT AND HEAVY RAIN TOOLS SUGGEST A CONSIDERABLE AMOUNT OF NEW CONVECTION SHOULD BE ACROSS NORTHEAST ILLINOIS AT MID DAY WITH ANOTHER VORT MAX. LIFT TOOL HAS A THETA E GRADIENT ACROSS ROUGHLY THE SOUTHEAST HALF OF THE CWFA DURING THE AFTERNOON WITH CONVERGENCE INCREASING. THUS SHOWERS WITH TSRA WILL BE MOST PREVALENT ACROSS ROUGHLY THE SOUTHERN HALF OF THE CWFA. CONVECTION WILL CONTINUE INTO THE EVENING HOURS WITH IT MOST NUMEROUS ACROSS THE SOUTHERN HALF OF THE CWFA. SUNSET WILL ALLOW THE ATMOSPHERE TO RE-STABILIZE SO CONVECTION WILL DIMINISH DURING THE EVENING. MCS AND LIFT TOOLS SUGGEST CONVECTION MAY PERSIST OR EVEN RE-DEVELOP AFTER MIDNIGHT ACROSS THE NORTHWEST THIRD TO HALF OF THE CWFA WITH CONVERGENCE INCREASING THERE AS ANOTHER VORT MAX ROTATES AROUND THE UPPER LOW. ..08.. .LONG TERM...SATURDAY THROUGH NEXT THURSDAY... MOSTLY DRY TO DRY WITH TEMPERATURES STILL ABOVE NORMAL BY AT LEAST SEVERAL DEGREES IF NOT MORE ALL DAYS....THOUGH NOT RECORD WARMTH. OVERALL...INITIALIZATION GOOD WITH UPSTREAM ENERGY AND VERIFICATION AND RUN TO RUN CONTINUITY SUPPORTING A 50/50 BLEND OF GFS/HI-RES ECMWF. LIMITED SENSIBLE IMPACTS WITH SOME LIGHT TO LOCALLY MODERATE RAIN AMOUNTS POSSIBLY WITH BACKDOOR COLD FRONT MONDAY INTO TUESDAY AHEAD OF NEXT SHORT WAVE. PERSISTENCE SUGGEST GUIDANCE TEMPS MAY STILL BE A FEW DEGREES TOO COOL FOR LATER SHIFTS TO CONSIDER MOST DAYS EXCEPT MONDAY WHEN BACKDOOR FRONT MAY BE COLDER WITH GOOD ADVECTION FROM NE WINDS OFF LAKE MICHIGAN. SATURDAY...KEPT LOW POPS WITH CONVECTIVE TEMPERATURE REACHED FOR MOSTLY PM POPCORN -SHRA. OTHERWISE...PARTLY SUNNY AND MILD WITH HIGHS MAINLY 70 TO 75 DEGREES WITH LIGHT WINDS. SATURDAY NIGHT... CLEARING AND A BIT COLDER WITH MINS AROUND 50 DEGREES BUT LIGHT WIND SUGGEST LATER SHIFTS MAY NEED TO TRIM AT LEAST A FEW DEGREES WITH GOOD BL DECOUPLING. SUNDAY...ANOTHER SPLENDID LATE MARCH DAY AHEAD OF BACKDOOR COLD FRONT WITH HIGHS WELL INTO THE 70S AND LIGHT NORTH WINDS. SUNDAY NIGHT...BACKDOOR ARRIVES BY LATE EVENING WITH NE WINDS OF 10-20+ MPH SUGGESTED. WENT WITH MINS OF LOWER 40S NE TO LOWER 50S SW BUT LATER SHIFTS MAY NEED TO TRIM AT LEAST A COUPLE MORE DEGREES MOST LOCATIONS. WITH OUR EXTENDED MILD WEATHER...THIS WILL FEEL COLDER THAN ONE WOULD EXPECT FOR LATE MARCH TO MANY. MONDAY THROUGH TUESDAY...LOCAL TECHNIQUES SUGGEST NE SECTIONS MAY STRUGGLE WITH IDEAL FETCH OFF LAKE MICHIGAN IN NE 1/2 OF AREA TO REACH THE MIDDLE 50S WITH GUSTY NE TO E WINDS OF 15-25+ MPH. LOW CLOUDS ALSO MAY RESULT IN GREATER IMPACT OF A COOL DAY. NEXT SHORT WAVE MAY SPAWN LIGHT RAIN AND RAIN SHOWERS MONDAY NIGHT INTO TUESDAY. THE STRENGTH OF FORCING SHOULD BE BETTER ASCERTAINED NEXT 12-24 HOURS. TUESDAY WARM FRONT SHOULD PASS BY MID DAY FOR TEMPERATURES BACK INTO THE 70S AND MINS TUESDAY NIGHT UPPER 40S TO LOWER 50S WITH -SHRA/-TSRA ENDING PROBABLY BY MIDNIGHT WITH PASSAGE OF COLD FRONT. ANY STORMS ATTM PROBABLY NON-SEVERE DUE TO LIMITED FORCING AND INSTABILITY. WEDNESDAY AND THURSDAY...MAINLY DRY WITH WEAK HIGH PRESSURE AND ONLY A BIT COOLER WITH HIGHS IN THE 60S AND MINS IN THE 40S. THIS IS STILL 10 PLUS DEGREES ABOVE NORMAL AS OUR REMARKABLE EXTENDED PERIOD OF MARCH WARM SPELL CONTINUES. ..NICHOLS.. && .AVIATION... VFR TO VLIFR CONDITIONS WILL BE SEEN THROUGH SUNRISE WITH CONDITIONS IMPROVING TO VFR. DAYTIME HEATING WILL ALLOW ANOTHER ROUND OF SHRA WITH TSRA TO DVLP WITH CONVECTION BEING MOST NUMEROUS DURING THE AFTERNOON. CONVECTION WILL DISSIPATE WITH SUNSET BUT MAY LINGER THROUGH THE NIGHT ACROSS EASTERN IOWA. KMLI/KBRL MAY HAVE THE BEST CHANCE AT SEEING TSRA WITH MVFR CONDITIONS AFT 18Z/23 AND WILL GO WITH VCTS IN THE 12Z TAFS. ..08.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ 08/NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
917 PM MDT SAT MAR 24 2012 .UPDATE... ISSUED AT 843 PM MDT SAT MAR 24 2012 JUST COMPLETED AN UPDATE. MAIN CHANGES WERE TO INCREASE COVERAGE OF THE FOG OVER THE ENTIRE AREA AND ISSUED A DENSE FOG ADVISORY FOR EAST CENTRAL COLORADO AND MUCH OF NORTHWEST KANSAS UNTIL 15Z SUNDAY MORNING. 00Z DDC AND LBF SOUNDINGS SHOW LOW LEVEL MOISTURE HAS INCREASED IN VALUE AND DEPTH FROM 24 HOURS AGO. MOST MODEL OUTPUT IS UNDERDOING THE LOW LEVEL MOISTURE. HOWEVER...THE RUC AND HRRR HAVE CAUGHT ONTO THIS HIGHER MOISTURE AND HAVE BEEN CONSISTENT IN KEEPING AND/OR INCREASING NOT ONLY THE COVERAGE OF THE FOG BUT THE EXTENT OF THE DENSE FOG. THE 00Z NAM HAS FINALLY CAUGHT ON AS WELL. ALL THREE MODELS ARE VERY CLOSE IN THEIR DEPICTION OF THE DENSE FOG AREA. SO HAD FAIRLY HIGH CONFIDENCE IN ISSUING THE ADVISORY FOR THE AREA IN QUESTION. OVERNIGHT SHIFT CAN TWEAK THIS FURTHER AS THE NIGHT PROGRESSES. WITH HIGHER DEWPOINTS ALSO RAISED THE MINS ACCORDINGLY...ESPECIALLY IN THE SOUTHERN HALF BASED ON REALITY/LATEST RUC/HRRR. RUC/HRRR WERE DOING WELL ON DEWPOINTS/WINDS AND USED THEM FOR THE UPDATE AS WELL. UPDATE ISSUED AT 549 PM MDT SAT MAR 24 2012 DID AN EARLY UPDATE. CURRENT DEWPOINTS OVER THE FORECAST AREA AND UPSTREAM ARE HIGHER THAN WHAT MOST MODEL OUTPUT INDICATES. THE HRRR FOOLLOWED BY THE RUC ARE CATCHING THE DEWPOINTS THE BEST AND INCREASE THE DEWPOINTS OVER THE ENTIRE AREA THROUGH THE NIGHT. USED THE HRRR FOR THE UPDATE. LATEST RUC AND NAM OUTPUT IS NOT ONLY INCREASING THE AREAL COVERAGE OF THE FOG BUT ALSO IS DECREASING THE VISIBILITY. SO INCREASED THE COVERAGE AND ALSO ADDED DENSE WORDING TO THE GRIDS. WILL CONTINUE TO WATCH THE TRENDS ON THE OBSERVATIONS PLUS WAIT FOR THE 00Z SOUNDINGS TO SEE IF A DENSE FOG ADVISORY WILL BE NEEDED BUT CHANCES OF THIS ARE ON THE INCREASE. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 254 PM MDT SAT MAR 24 2012 500 MB RIDGE WILL REMAIN OVER THE FORECAST AREA THROUGH SUNDAY BEFORE IT SHIFTS EAST SUNDAY NIGHT. SURFACE DEWPOINTS WILL BE IN THE 40S MOST AREAS TONIGHT...AND DEW POINT DEPRESSIONS WILL BE LOW AFTER 09Z. WITH LIGHT WINDS AND WEAK SUBSIDENCE...EXPECT PATCHY FOG TO DEVELOP LATE TONIGHT. FOG MAY BE MORE WIDESPREAD/DENSE THAN LAST NIGHT GIVEN THE INCREASE OF LOW LEVEL DEW POINTS...BUT WILL MONITOR THE EVOLUTION OF FOG FORMATION BEFORE HOISTING ANY HIGHLIGHTS. WILL UPDATE THE HAZARDOUS WEATHER OUTLOOK...HOWEVER...FOR FOG POSSIBILITIES. THERMAL RIDGE WILL MOVE ACROSS THE AREA SUNDAY WHICH WILL PRODUCE HIGH TEMPERATURES IN THE LOWER 80S. A DRY LINE WILL DEVELOP OVER EASTERN COLORADO DURING THE AFTERNOON...AND IT WILL PUSH EAST DURING THE AFTERNOON REACHING THE KANSAS BORDER BY 21Z. CONSIDERED INTRODUCING CONVECTION INTO THE FORECAST EAST OF THE DRY LINE AS MIXED LAYER CAPES WILL BE DECENT IN THE MOIST AIR. HODOGRAPHS ALSO SHOW GOOD SHEAR. HOWEVER...WITH THE AMOUNT OF INHIBITION AND LACK OF DECENT LOW TO MID LEVEL SUPPORT...DECIDED AGAINST THUNDERSTORMS. WEST OF THE DRY LINE...EXPECT RELATIVE HUMIDITIES TO DROP TO 15 PERCENT IN EASTERN COLORADO MAINLY ACROSS WESTERN KIT CARSON AND WESTERN CHEYENNE COUNTIES. SURFACE WINDS WILL ONLY BE AROUND 15 MPH...SO WILL NOT MENTION ANY FIRE WEATHER HIGHLIGHTS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 254 PM MDT SAT MAR 24 2012 NUMEROUS CONCERNS FOR FORECAST AREA ON MONDAY INCLUDING POTENTIAL FOR A FEW RECORD HIGHS (SEE CLIMATE SECTION BELOW), STRONG FIRE WEATHER POTENTIAL (SEE FIRE WEATHER SECTION BELOW), AND POTENTIAL FOR CONVECTION DURING THE LATE AFTERNOON AND EVENING HOURS. FAIRLY POTENT SHORTWAVE TROUGH IS PROGGED TO MOVE OUT OF THE GREAT BASIN AND INTO THE WESTERN DAKOTAS DURING THE DAY. A DRYLINE WILL SET UP INITIALLY ALONG THE KS/CO BORDER AND IS PROGGED TO MIX EASTWARD TOWARD THE HIGHWAY 25 CORRIDOR BY MID AFTERNOON. THERE IS SOME DEGREE OF UNCERTAINTY WITH REGARD TO THE EXACT PLACEMENT OF THE DRYLINE AND THIS WILL HAVE AN IMPACT ON THE POTENTIAL FOR CONVECTION AT ANY ONE LOCATION. ADDITIONALLY, STRONGEST FORCING FOR ASCENT WILL RESIDE NORTH OF THE FORECAST AREA SO FEEL CONFIDENT IN KEEPING SLIGHT CHANCE POPS GOING. HAVING SAID THAT...PARAMETERS WOULD FAVOR STRONG/SEVERE CONVECTION SHOULD SOMETHING GET GOING. FEEL BEST SHOT FOR CONVECTION IS FURTHER EAST THAN PREVIOUSLY ADVERTISED SO NUDGED POPS THAT DIRECTION. HAVE ALSO INSERTED BLOWING DUST MENTION FOR LOCATIONS TO THE WEST OF THE DRYLINE. DESPITE RECENT PRECIP...SOIL MOISTURE DEFICITS REMAIN HIGH. ALSO VERY CONCERNED ABOUT BLOWING DUST/SAND ACROSS CENTRAL PORTIONS OF YUMA COUNTY WHERE A VERY LARGE BURN SCAR FROM A FIRE LAST SUNDAY WILL ENHANCED POTENTIAL FOR REDUCED VISIBILITIES. SLIGHTLY COOLER...BUT STILL MUCH ABOVE NORMAL...AIR MOVES INTO THE CENTRAL HIGH PLAINS ON TUESDAY. GIVEN LATEST PROGS...DID BUMP MAX TEMPS UP A FEW DEGREES ACROSS THE AREA. BROAD/FLAT RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS WEDNESDAY WITH A WEAK SHORTWAVE TROUGH PROGGED TO PASS THURSDAY INTO THURSDAY NIGHT. SLIGHT CHANCE POPS ACROSS THE EAST INITIALLY IN MOIST SOUTHEAST FLOW BEFORE SPREADING OVER THE REMAINDER OF THE FORECAST AREA. MUCH ABOVE NORMAL TEMPS WILL CONTINUE INTO THE WEEKEND WITH TEMPS REMAINING IN THE 70S TO NEAR 80. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 511 PM MDT SAT MAR 24 2012 POTENTIAL STILL EXISTS FOR FOG TO DEVELOP AT BOTH LOCATIONS SUNDAY MORNING. THEREFORE...HAVE PLACED IFR CIG/VIS AT BOTH LOCATIONS 11-15Z. AFTERWARDS...WINDS WILL BECOME GUSTY AT BOTH LOCATIONS FROM THE SOUTHEAST. VFR CONDITIONS WILL EXIST THROUGH 11Z AND AGAIN AFTER 15Z AT BOTH LOCATIONS. && .FIRE WEATHER... ISSUED AT 254 PM MDT SAT MAR 24 2012 BORDERLINE FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS EASTERN COLORADO ON SUNDAY. HOWEVER...WIND SPEEDS ARE EXPECTED TO REMAIN BELOW CRITERIA NEEDED FOR ISSUANCE OF A RED FLAG WARNING. A MORE SUBSTANTIAL CRITICAL FIRE WEATHER DAY APPEARS LIKELY ALONG AND WEST OF HIGHWAY 25 ON MONDAY TO THE WEST OF A FAIRLY STOUT DRYLINE. GIVEN HIGH CONFIDENCE...WILL GO AHEAD AND ISSUE A FIRE WEATHER WATCH FOR THESE LOCATIONS. RECENT PRECIP AND THE RESULTANT GREEN UP MAY HELP MITIGATE THE THREAT BUT SUBSTANTIAL DRY FUELS REMAIN ACROSS THE TRI-STATE REGION. RH VALUES WILL BE BELOW 20 PERCENT AGAIN ON TUESDAY...WEDNESDAY ...AND THURSDAY ACROSS WESTERN PORTIONS OF THE AREA BUT CURRENT INDICATIONS WOULD SHOW THE WIND SPEEDS SHOULD REMAIN LIGHT AT AROUND 10 MPH OR LESS. && .CLIMATE... ISSUED AT 254 PM MDT SAT MAR 24 2012 POTENTIAL CONTINUES TO EXIST FOR A FEW RECORD HIGHS TO FALL ON MONDAY BUT THE BIGGER STORY BY THIS TIME NEXT WEEKEND WILL BE THE FACT THAT A FEW LOCATIONS WILL HAVE SET AN ALL-TIME RECORD FOR THE WARMEST AVERAGE TEMPERATURE. CURRENT RECORDS ARE AS FOLLOWS: GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.0 BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 46.7 MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.5 HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 50.8 WITH FORECASTED TEMPS...CONFIDENCE IS HIGH THAT AT LEAST GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON RECORD. IT REMAINS TO BE SEEN IF HILL CITY WILL BREAK THE RECORD AS WELL. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR COZ252>254. DENSE FOG ADVISORY FROM 1 AM TO 9 AM MDT SUNDAY FOR COZ090>092. KS...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR KSZ001-002-013-014-027-028-041-042. DENSE FOG ADVISORY FROM 1 AM MDT /2 AM CDT/ TO 9 AM MDT /10 AM CDT/ SUNDAY FOR KSZ013>016-027>029-041-042. NE...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR NEZ079-080. && $$ UPDATE...BULLER SHORT TERM...MENTZER LONG TERM....FOLTZ AVIATION...BAS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
911 PM CDT SAT MAR 24 2012 .UPDATE... ISSUED AT 903 PM CDT SAT MAR 24 2012 HAVE UPDATED HOURLY DEWPOINT GRIDS BASED OFF THE FACT THAT THE ALL THE MODELS (GFS, NAM, HRRR) ARE UNDOING SURFACE DEWPOINTS (TD`S). TD`S HAVE BEEN RUNNING IN THE LOWER 50S DEG F ACROSS KDDC COUNTRY THIS EVENING. TONIGHTS 00Z RAOB AT THE WFO SHOW THE INCREASING POTENTIAL FOR DENSE FOG. LAMP GUIDANCE HAS COME IN AT IFR CIGS FOR KGCK AND KDDC. THE LAST HOUR FROM THE HRRR SHOWS VISIBILITIES AT 0.25 MILES. CONTINUED UPSLOPE SOUTHEASTERLY WINDS ARE EXPECTED THROUGH THE OVERNIGHT. AS A RESULT, HAVE ISSUED A DENSE FOG ADVISORY FOR MY WESTERN COUNTIES. STARTED OUT CONSERVATIVE SINCE THE MID SHIFT COULD ADD MORE COUNTIES EASTWARD IF NEED BE AND AS SUGGESTED BY LAMP GUIDANCE AND POSSIBLY LATER MODEL RUNS. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 345 PM CDT SAT MAR 24 2012 A GENERAL WARMING TREND IS ANTICIPATED IN THE VERY SHORT TERM FORECAST. TEMPERATURES WARMED INTO THE LOW TO MID 70S THIS AFTERNOON AND WERE HEADED TOWARD THE 80 DEGREE MARK IN THE LATE AFTERNOON. THE AREA WILL REMAIN IN THE WARM SECTOR SOUTH TO SOUTHEAST FLOW AS WEAK CYCLOGENESIS REMAINS FOCUSED DIURNALLY OVER SOUTHEAST COLORADO. SURFACE MOISTURE WILL INCREASE ACROSS THE AREA INCREASING DEW POINTS INTO THE 50S THE NEXT FEW DAYS. THE COMBINATION OF SOUTHEAST UPSLOPE WINDS AND HIGHER LEVEL MOISTURE AIR, ACROSS THE AREA WILL BE FAVORABLE FOR DENSE FOG DEVELOPMENT AS TEMPERATURES FALL OVERNIGHT UNDER A VERY DRY MID AND UPPER LEVEL AIRMASS. THE RUC AND NAM BOTH INDICATE DENSE FOG DEVELOPMENT, AND ARE NOT IN AGREEMENT AT ALL ON THE PLACEMENT. HOWEVER THE MOST FAVORABLE LOCATION FOR WIDESPREAD DENSE FOG DEVELOPMENT WILL BE WHERE THE WINDS GO LIGHT IN THE ZONE OF SURFACE WIND CONVERGENCE PROBABLY AFTER 8Z. DEW POINTS WILL LIKELY MIX OUT TO LOWER VALUES IN THE FAR WESTERN COUNTIES ON SUNDAY. THE NAM INDICATED THE REAL DRYLINE TO BE POSITIONED WELL TO THE SOUTHWEST IN NE NEW MEXICO WHERE IT WANTS TO DEVELOP CONVECTIVE PRECIPITATION IN THE LATE AFTERNOON AS IT IS RETREATING. HAVING SAID THAT, THE SURFACE POSITIVE BUOYANT ENERGY IS A RESPECTABLE 1000-2000 J/KG FROM A DIGHTON TO MEADE CORRIDOR AS MODELED BY THE NAM. HOWEVER, THE ATMOSPHERE ALOFT REMAINS DRY ON SUNDAY. THE WARM NOSE ON THE 21 UTC NAM SOUNDING SUGGESTS PARCELS WOULD NEED TO BE LIFTED FROM ABOVE 800 MB WHICH DOESN`T APPEAR PLAUSIBLE WITH SUCH WEAK SURFACE CONVERGENCE AND DRY AIR. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 256 PM CDT SAT MAR 24 2012 SUNDAY NIGHT WILL SEE AN UPPER LEVEL RIDGE WORK EASTWARD INTO EASTERN KANSAS. AN UPPER LOW PRESSURE SYSTEM OVER SOUTHERN NEVADA WILL ALLOW A SOUTHWEST UPPER FLOW TO DEVELOP ACROSS WESTERN KANSAS MONDAY. A DRY LINE WILL START ADVANCING WEST EARLY IN THE DAY MONDAY, AND SOUTH WINDS WILL BECOME STRONG, ESPECIALLY IN OUR WEST ON THE MOIST SIDE OF THE DRY LINE. FOR NOW, GRIDS WILL HAVE 25-35KTS G40KTS IN MY WESTERN 1/2 OF THE CWA, AND 15-25KTS G30KTS IN THE EASTERN CWA. A WIND ADVISORY WILL LIKELY BE NEEDED FOR MONDAY AFTERNOON, BUT WILL HOLD OFF ONE OR TWO MORE SHIFTS BEFORE ISSUING THE NPW PRODUCT. STORMS MAY FIRE IN THE LATE DAY IN OUR WEST NEAR THE DRY LINE, BUT THE BETTER UPPER LEVEL DYNAMICS ARE TO OUR NORTH. THE 20 POPS SEEM APPROPRIATE FOR THIS SITUATION, UNLESS LATER MODEL RUNS SHOW SOMETHING DIFFERENT. FOR WHAT IT IS WORTH, THE GFS BACKED OFF ON THUNDERSTORMS MONDAY AFTERNOON, KEEPING THE PRECIPITATION FAR TO OUR NORTH. MONDAY NIGHT WILL BE PARTLY TO MOSTLY CLOUDY WITH A WEAK UPPER TROUGH CROSSING JUST TO OUR NORTH. A FAIRLY STRONG COLD FRONT WILL SLIP INTO OUR NORTHWEST SECTIONS AFTER MIDNIGHT AND BE NEAR OUR SOUTHERN BORDER BY TUESDAY MORNING. THEN, THE FRONT APPEARS TO DISSIPATE NEAR THE OKLAHOMA TUESDAY MORNING, BEFORE STARTING TO ADVANCE BACK NORTH AS A WARM FRONT WEDNESDAY. SINCE THAT FRONT IS PLOWING THROUGH DECENT LOW LEVEL MOISTURE, 20 PERCENT POPS WILL START IN THE WEST LATE MONDAY AND TRANSFER TO THE EAST MONDAY NIGHT. SEEMS THERE WILL BE AT LEAST A SMALL CHANCE FOR SEVERE STORMS WITH HAIL MONDAY NIGHT, BUT WITH 20 POPS DO NOT PLAN TO MENTION SEVERE STORMS IN THE GRIDS. WILL UPDATE THE HWO TO AT LEAST MENTION SEVERE STORMS ARE POSSIBLE. NO PLANS IN OUR 3 WESTERN COUNTIES FOR POPS MONDAY NIGHT. MIN TEMPS MON NIGHT WILL DEPEND STRONGLY ON THE COLD FRONT MOVEMENT AND POSITION, AND RANGE FROM THE LOWER 40S IN OUR EXTREME NORTHWEST COUNTIES SUCH AS HAMILTON TO THE LOWER 50S FROM HAYS TO DODGE CITY TO NEAR LIBERAL, AND THE MID 50S IN THE PRATT AND BARBER COUNTY AREAS. ANY PRECIP SHOULD BE EAST OF OUR CWA BY TUESDAY, WITH MAX TEMPS BEHIND THE FRONT 10 TO 15 DEGREES COLDER THAN MONDAY, MAXING IN THE 70 DEGREE RANGE IN SCOTT CITY TO NEAR 77 DEGREES IN MEDICINE LODGE. TUESDAY SHOULD PRODUCE SUNNY SKIES AS WELL. TUESDAY NIGHT WILL BE MOSTLY CLEAR WITH NO PRECIPITATION, AND MINIMUMS IN THE LOWER 40S IN OUR NORTHWEST RANGING TO THE MID 50S IN OUR SOUTHEAST. ON WEDNESDAY, THAT FRONT WILL ADVANCE NORTH AS A WARM FRONT AND MOVE INTO OUR SOUTHERN CWA. SOUTHERN PARTS OF OUR CWA WILL BECOME PARTLY CLOUDY WHILE NORTHERN PARTS OF OUR FORECAST CONTINUING TO BE MOSTLY SUNNY. LATE WEDNESDAY, THERE IS A SLIGHT CHANCE FOR A THUNDERSTORM IN OUR EXTREME SOUTHEAST, DUE TO DAY TIME HEATING AND DEW POINTS NEAR 60F DEGREES. EXPECT PARTLY CLOUDY SKIES WEDNESDAY NIGHT, LOW TEMPS IN THE 50F TO 56F DEGREE RANGE, AND A SLIGHT CHANCE OF STORMS IN OUR EASTERN 2 COUNTIES OF THE CWA. ON THURSDAY, THE DRY LINE WILL COME BACK INTO PLAY, MARCHING EAST ACROSS OUR AREA DURING THE DAY. BY THE TIME OF MAX HEATING, WITH HIGHS EXPECTED IN THE UPPER 70S TO LOWER 80S, A THUNDERSTORM OR TWO WILL BE POSSIBLE NEAR THE DRY LINE. THURSDAY NIGHT WILL CONTINUE TO SEE SLIGHT CHANCES FOR STORMS, WITH THAT CHANCE SPREADING WEST ACROSS ALL OUR CWA BY FRIDAY. AN UPPER WAVE WILL CROSS JUST NORTH OF OUR CWA, AND MAY FIRE OFF A FEW STORMS FRIDAY AND FRIDAY NIGHT. MAX TEMPS EXPECTED FRIDAY ARE IN THE MID 70S, WITH MIN TEMPS FROM 46F TO 54F DEGREES FRIDAY NIGHT, AND MAXIMUM TEMPERATURES ON SATURDAY RANGING IN THE MID TO UPPER 70S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 606 PM CDT SAT MAR 24 2012 FRCST CONCERN FOR THE 00Z TAFS IS THE POTENTIAL FOR FOG. SREF SHOWS LOW PROBS FOR +FG ACROSS FAR SW KS. BUFKIT SND`S SHOW A VERY SHALLOW RADIATIVE FG PROFILE. THE MOST AGGRESSIVE MOS...GFS LAV...SHOWS ABOUT 4 MI AT KGCK/KDDC. NAM IS RUNNING A LITTLE LOW W/ TD`S AT 22Z. WITH TD`S IN THE LOW 50SF AND UPSLOPE SE WINDS OVERNIGHT, DID NOT WANT TO DEVIATE THAT MUCH FROM PREVIOUS SHIFT FOR FG BUT NOT READY TO GO 1/4 MILE SINCE MOST OF THE MODELS SUGGESTS OTHERWISE. AS A RESULT, TRENDED TAFS TO LOWER VIS WITH 1 MI AT KGCK AND 2 MI AT KDDC BY MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 50 81 57 82 / 0 0 0 20 GCK 50 82 56 83 / 0 0 0 20 EHA 48 85 55 85 / 0 0 0 10 LBL 49 84 56 83 / 0 0 0 20 HYS 48 80 57 82 / 0 0 0 10 P28 50 81 57 82 / 0 0 0 10 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY FROM 2 AM CDT /1 AM MDT/ TO 9 AM CDT /8 AM MDT/ SUNDAY FOR KSZ030-043>045-061>063-074-075-084-085. && $$ UPDATE...SUGDEN SHORT TERM...RUSSELL LONG TERM....BURKE AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
602 PM MDT SAT MAR 24 2012 .UPDATE... ISSUED AT 549 PM MDT SAT MAR 24 2012 DID AN EARLY UPDATE. CURRENT DEWPOINTS OVER THE FORECAST AREA AND UPSTREAM ARE HIGHER THAN WHAT MOST MODEL OUTPUT INDICATES. THE HRRR FOOLLOWED BY THE RUC ARE CATCHING THE DEWPOINTS THE BEST AND INCREASE THE DEWPOINTS OVER THE ENTIRE AREA THROUGH THE NIGHT. USED THE HRRR FOR THE UPDATE. LATEST RUC AND NAM OUTPUT IS NOT ONLY INCREASING THE AREAL COVERAGE OF THE FOG BUT ALSO IS DECREASING THE VISIBILITY. SO INCREASED THE COVERAGE AND ALSO ADDED DENSE WORDING TO THE GRIDS. WILL CONTINUE TO WATCH THE TRENDS ON THE OBSERVATIONS PLUS WAIT FOR THE 00Z SOUNDINGS TO SEE IF A DENSE FOG ADVISORY WILL BE NEEDED BUT CHANCES OF THIS ARE ON THE INCREASE. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 254 PM MDT SAT MAR 24 2012 500 MB RIDGE WILL REMAIN OVER THE FORECAST AREA THROUGH SUNDAY BEFORE IT SHIFTS EAST SUNDAY NIGHT. SURFACE DEWPOINTS WILL BE IN THE 40S MOST AREAS TONIGHT...AND DEW POINT DEPRESSIONS WILL BE LOW AFTER 09Z. WITH LIGHT WINDS AND WEAK SUBSIDENCE...EXPECT PATCHY FOG TO DEVELOP LATE TONIGHT. FOG MAY BE MORE WIDESPREAD/DENSE THAN LAST NIGHT GIVEN THE INCREASE OF LOW LEVEL DEW POINTS...BUT WILL MONITOR THE EVOLUTION OF FOG FORMATION BEFORE HOISTING ANY HIGHLIGHTS. WILL UPDATE THE HAZARDOUS WEATHER OUTLOOK...HOWEVER...FOR FOG POSSIBILITIES. THERMAL RIDGE WILL MOVE ACROSS THE AREA SUNDAY WHICH WILL PRODUCE HIGH TEMPERATURES IN THE LOWER 80S. A DRY LINE WILL DEVELOP OVER EASTERN COLORADO DURING THE AFTERNOON...AND IT WILL PUSH EAST DURING THE AFTERNOON REACHING THE KANSAS BORDER BY 21Z. CONSIDERED INTRODUCING CONVECTION INTO THE FORECAST EAST OF THE DRY LINE AS MIXED LAYER CAPES WILL BE DECENT IN THE MOIST AIR. HODOGRAPHS ALSO SHOW GOOD SHEAR. HOWEVER...WITH THE AMOUNT OF INHIBITION AND LACK OF DECENT LOW TO MID LEVEL SUPPORT...DECIDED AGAINST THUNDERSTORMS. WEST OF THE DRY LINE...EXPECT RELATIVE HUMIDITIES TO DROP TO 15 PERCENT IN EASTERN COLORADO MAINLY ACROSS WESTERN KIT CARSON AND WESTERN CHEYENNE COUNTIES. SURFACE WINDS WILL ONLY BE AROUND 15 MPH...SO WILL NOT MENTION ANY FIRE WEATHER HIGHLIGHTS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 254 PM MDT SAT MAR 24 2012 NUMEROUS CONCERNS FOR FORECAST AREA ON MONDAY INCLUDING POTENTIAL FOR A FEW RECORD HIGHS (SEE CLIMATE SECTION BELOW), STRONG FIRE WEATHER POTENTIAL (SEE FIRE WEATHER SECTION BELOW), AND POTENTIAL FOR CONVECTION DURING THE LATE AFTERNOON AND EVENING HOURS. FAIRLY POTENT SHORTWAVE TROUGH IS PROGGED TO MOVE OUT OF THE GREAT BASIN AND INTO THE WESTERN DAKOTAS DURING THE DAY. A DRYLINE WILL SET UP INITIALLY ALONG THE KS/CO BORDER AND IS PROGGED TO MIX EASTWARD TOWARD THE HIGHWAY 25 CORRIDOR BY MID AFTERNOON. THERE IS SOME DEGREE OF UNCERTAINTY WITH REGARD TO THE EXACT PLACEMENT OF THE DRYLINE AND THIS WILL HAVE AN IMPACT ON THE POTENTIAL FOR CONVECTION AT ANY ONE LOCATION. ADDITIONALLY, STRONGEST FORCING FOR ASCENT WILL RESIDE NORTH OF THE FORECAST AREA SO FEEL CONFIDENT IN KEEPING SLIGHT CHANCE POPS GOING. HAVING SAID THAT...PARAMETERS WOULD FAVOR STRONG/SEVERE CONVECTION SHOULD SOMETHING GET GOING. FEEL BEST SHOT FOR CONVECTION IS FURTHER EAST THAN PREVIOUSLY ADVERTISED SO NUDGED POPS THAT DIRECTION. HAVE ALSO INSERTED BLOWING DUST MENTION FOR LOCATIONS TO THE WEST OF THE DRYLINE. DESPITE RECENT PRECIP...SOIL MOISTURE DEFICITS REMAIN HIGH. ALSO VERY CONCERNED ABOUT BLOWING DUST/SAND ACROSS CENTRAL PORTIONS OF YUMA COUNTY WHERE A VERY LARGE BURN SCAR FROM A FIRE LAST SUNDAY WILL ENHANCED POTENTIAL FOR REDUCED VISIBILITIES. SLIGHTLY COOLER...BUT STILL MUCH ABOVE NORMAL...AIR MOVES INTO THE CENTRAL HIGH PLAINS ON TUESDAY. GIVEN LATEST PROGS...DID BUMP MAX TEMPS UP A FEW DEGREES ACROSS THE AREA. BROAD/FLAT RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS WEDNESDAY WITH A WEAK SHORTWAVE TROUGH PROGGED TO PASS THURSDAY INTO THURSDAY NIGHT. SLIGHT CHANCE POPS ACROSS THE EAST INITIALLY IN MOIST SOUTHEAST FLOW BEFORE SPREADING OVER THE REMAINDER OF THE FORECAST AREA. MUCH ABOVE NORMAL TEMPS WILL CONTINUE INTO THE WEEKEND WITH TEMPS REMAINING IN THE 70S TO NEAR 80. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 511 PM MDT SAT MAR 24 2012 POTENTIAL STILL EXISTS FOR FOG TO DEVELOP AT BOTH LOCATIONS SUNDAY MORNING. THEREFORE...HAVE PLACED IFR CIG/VIS AT BOTH LOCATIONS 11-15Z. AFTERWARDS...WINDS WILL BECOME GUSTY AT BOTH LOCATIONS FROM THE SOUTHEAST. VFR CONDITIONS WILL EXIST THROUGH 11Z AND AGAIN AFTER 15Z AT BOTH LOCATIONS. && .FIRE WEATHER... ISSUED AT 254 PM MDT SAT MAR 24 2012 BORDERLINE FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS EASTERN COLORADO ON SUNDAY. HOWEVER...WIND SPEEDS ARE EXPECTED TO REMAIN BELOW CRITERIA NEEDED FOR ISSUANCE OF A RED FLAG WARNING. A MORE SUBSTANTIAL CRITICAL FIRE WEATHER DAY APPEARS LIKELY ALONG AND WEST OF HIGHWAY 25 ON MONDAY TO THE WEST OF A FAIRLY STOUT DRYLINE. GIVEN HIGH CONFIDENCE...WILL GO AHEAD AND ISSUE A FIRE WEATHER WATCH FOR THESE LOCATIONS. RECENT PRECIP AND THE RESULTANT GREEN UP MAY HELP MITIGATE THE THREAT BUT SUBSTANTIAL DRY FUELS REMAIN ACROSS THE TRI-STATE REGION. RH VALUES WILL BE BELOW 20 PERCENT AGAIN ON TUESDAY...WEDNESDAY ...AND THURSDAY ACROSS WESTERN PORTIONS OF THE AREA BUT CURRENT INDICATIONS WOULD SHOW THE WIND SPEEDS SHOULD REMAIN LIGHT AT AROUND 10 MPH OR LESS. && .CLIMATE... ISSUED AT 254 PM MDT SAT MAR 24 2012 POTENTIAL CONTINUES TO EXIST FOR A FEW RECORD HIGHS TO FALL ON MONDAY BUT THE BIGGER STORY BY THIS TIME NEXT WEEKEND WILL BE THE FACT THAT A FEW LOCATIONS WILL HAVE SET AN ALL-TIME RECORD FOR THE WARMEST AVERAGE TEMPERATURE. CURRENT RECORDS ARE AS FOLLOWS: GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.0 BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 46.7 MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.5 HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 50.8 WITH FORECASTED TEMPS...CONFIDENCE IS HIGH THAT AT LEAST GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON RECORD. IT REMAINS TO BE SEEN IF HILL CITY WILL BREAK THE RECORD AS WELL. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR COZ252>254. KS...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR KSZ001-002-013-014-027-028-041-042. NE...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR NEZ079-080. && $$ UPDATE...BULLER SHORT TERM...MENTZER LONG TERM....FOLTZ AVIATION...BAS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
526 AM MDT FRI MAR 23 2012 .UPDATE... ISSUED AT 407 AM MDT FRI MAR 23 2012 SHALLOW FOG HAS PRODUCED VISIBILITIES OF 1 TO 5 MILES...WITH LOWER VISIBILITIES IN THE VALLEYS AND RIVER BOTTOMS AS OVERHEAD CLOUDS HAVE DISSIPATED. FOGGY CONDITIONS SHOULD START TO IMPROVE AFTER 6AM MDT/ 7AM CDT AS TEMPERATURES BEGIN TO WARM...WITH THE FOG COMPLETELY DISSIPATED BY MID MORNING. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 319 AM MDT FRI MAR 23 2012 SOME PATCHY FOG WILL BE POSSIBLE ACROSS THE AREA THIS MORNING DUE TO THE MOIST GROUND CONDITIONS FROM YESTERDAY/S RAINFALL. THE FOG SHOULD DISSIPATE BY MID MORNING. THE CLOSED UPPER LEVEL LOW THAT BROUGHT RAIN TO THE REGION YESTERDAY WILL CONTINUE TO MOVE EAST TODAY. AN UPPER LEVEL RIDGE WILL MOVE INTO THE AREA BEHIND THE CLOSED LOW TODAY. AS A RESULT WINDS WILL BE LIGHT. AS THE CLOSED LOW MOVES EAST...WARMER AIR WILL MOVE IN FROM THE WEST. WITH 850MB TEMPS AROUND 15C...TEMPS AROUND 70 WILL BE POSSIBLE. TONIGHT LOWS WILL DIP TO THE UPPER 30S TO AROUND 40. RELATIVE HUMIDITIES WILL BE NEAR 100 PERCENT OVERNIGHT...HOWEVER WILL HOLD OFF PLACING FOG IN THE FORECAST AS POINT SOUNDINGS SHOW A VERY SHALLOW SATURATED LAYER AT THE SURFACE. SATURDAY THE UPPER LEVEL RIDGE WILL CONTINUE TO MOVE OVER THE AREA. AT THE SURFACE A TROUGH OF LOW PRESSURE WILL MOVE IN FROM THE WEST DURING THE MORNING THEN MOVE NORTH DURING THE AFTERNOON AS A WARM FRONT. 850MB TEMPS OF 20C WILL MOVE OVER THE AREA BEHIND THE FRONT...ALLOWING HIGHS TO WARM TO NEAR 80 DEGREES DURING THE AFTERNOON. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 319 AM MDT FRI MAR 23 2012 SATURDAY NIGHT LOWS WILL DIP INTO THE MID TO UPPER 40S. PATCHY FOG WILL BE POSSIBLE GENERALLY ALONG AND EAST OF THE COLORADO BORDER THROUGH MID MORNING SUNDAY. SUNDAY SOUTH WINDS WILL INCREASE AS THE SURFACE PRESSURE GRADIENT TIGHTENS AND THE 850MB WINDS STRENGTHEN. WIND GUSTS OF 35 MPH WILL BE POSSIBLE DURING THE AFTERNOON. DURING THE AFTERNOON CAPE VALUES OF 500-1500J/KG WILL DEVELOP OVER NORTHWEST KANSAS AND SOUTHWEST NEBRASKA AS DEW POINTS MOISTEN INTO THE 50S. WILL HOLD OFF PLACING THUNDERSTORMS IN THE FORECAST AS POINT SOUNDINGS SHOW LARGE DEW POINT DEPRESSIONS THROUGH THE COLUMN. THE GUSTY SOUTH WINDS AND 850MB TEMPS OF 20C WILL HELP TEMPERATURES TO WARM INTO THE UPPER 70S AND LOWER 80S. MONDAY-THURSDAY...MEDIUM RANGE MODELS REMAIN IN REASONABLE AGREEMENT WITH RESPECT TO LARGE SCALE PATTERN WITH SOME ACTIVE WEATHER POSSIBLE ON MONDAY AS STRONG SHORT WAVE TROUGH LIFTS ACROSS THE NORTHERN PLAINS...FORCING COLD FRONT ACROSS THE CWA. LATEST OPERATIONAL GUIDANCE AND ENSEMBLE DATA CONTINUE TO SUPPORT AT LEAST A SMALL THREAT FOR THUNDERSTORMS ACROSS EASTERN CWA AND DO NOT SEE MUCH OF A REASON TO DEVIATE FROM THAT. AFTER THIS INITIAL SYSTEM...SOMEWHAT AMPLIFIED YET PROGRESSIVE FLOW ALOFT IS EXPECTED THROUGH THE END OF THE PERIOD WITH SOME WEAK TROUGHING EXPECTED BY THURSDAY. OVERALL...WOULD NOT BE SURPRISED TO SEE SOME SCATTERED SHOWERS AND THUNDERSTORMS IN A FEW OF THE PERIODS...BUT OVERALL THINK PROBABILITIES TO LOW TO REALLY TRY TO PIN DOWN GIVEN OVERALL WEAK EXPECTED FORCING. THINK BIGGEST CONCERN OF THE EXTENDED PERIOD WILL BE MONDAY...WITH POSITION OF UPPER TROUGH LOOKS LIKE STRONG JET OF LOW LEVEL WINDS WILL DEVELOP ACROSS MUCH OF THE AREA WITH H7 FLOW INCREASING TO 45 TO 50 KTS. IN ADDITION TO THE STRONG WINDS...TEMPERATURES WELL INTO THE 80S AND MUCH DRIER AIR MOVING INTO THE AREA BEHIND A DRYLINE WILL ONCE AGAIN INCREASE THE FIRE DANGER TO POTENTIALLY CRITICAL LEVELS. WILL NEED TO SEE WHAT IMPACT THE WIDESPREAD RAIN HAD ON FUELS...BUT WILL HAVE TO WATCH THIS PERIOD CLOSELY THE NEXT SEVERAL DAYS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 517 AM MDT FRI MAR 23 2012 IFR TO VFR CONDITIONS WILL BE POSSIBLE FOR THE TAFS. LATEST OBSERVATIONS REPORT SHALLOW FOG AT KGLD...WITH VIS VARYING FROM 1SM TO 10SM. SATELLITE IMAGERY SHOWS A DECK OF LOW CLOUDS MOVING SOUTH TOWARD KGLD. LATEST REPORT FROM ST. FRANCIS HAS CEILINGS OF 3500FT...SO CEILINGS SHOULD REMAIN ABOVE MVFR. FOR KMCK VIS HAVE BEEN SLOWLY FALLING OVER THE LAST HOUR OR SO. RUC AND NAM POINT SOUNDINGS SHOW A SHALLOW SATURATED LAYER AT THE SURFACE. THIS MAY CAUSE THE VIS TO VARY SO HAVE PLACED A TEMPO GROUP FOR VFR VIS AND A PREVAILING MVFR VIS. CONDITIONS SHOULD IMPROVE AROUND 15Z. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...NONE. KS...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...JTL LONG TERM....JRM AVIATION...JTL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1230 AM CDT FRI MAR 23 2012 ...UPDATED AVIATION SECTION... .UPDATE... ISSUED AT 741 PM CDT THU MAR 22 2012 HAVE PULLED POPS AND WX OUT OF THE GRIDS AS KDDC WSR-88D IS NOT INDICATING ANY RETURNED POWER AT 0.50 DEG AND HIGHER. CLOUD TOPS PER IR SATELLITE CHANNEL HAVE BEEN WARMING ACROSS THE CENTRAL AND EASTERN SECTIONS OF THE CWFA AS WELL. LASTLY, THE 00Z KDDC RAOB SHOWED WARMING AND DRYING THROUGH THE ATMOSPHERIC COLUMN WITH THE PWAT AT 0.51 INCHES NOW. AM WATCHING A BAND OF PRECIPITATION ACROSS EASTERN COLORADO ASSOCIATED WITH THE MAIN UPPER LEVEL LOW FURTHER TO THE SE. THE HRRR HAS PICKED UP WELL ON THIS FEATURE. HAVE DOUBTS ANY PRECIPITATION WILL REACH THE GROUND ACROSS FAR WESTERN KANSAS AS THIS MOISTURE LOOKS CONFINED MAINLY TO THE LOWER TO MID LEVELS AROUND 700 TO 500 HPA. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 343 PM CDT THU MAR 22 2012 MAIN SHORT TERM CHALLENGES TONIGHT WILL BE THE TIMING OF THE END OF PRECIPITATION. INDICATIONS FROM THE RUC, HRRR, AND NAM12 WOULD SEEM TO INDICATE THAT THE SHOWER ACTIVITY WILL BE WANING OVER THE NEXT COUPLE OF HOURS. POPS WILL BE RAPIDLY DECREASING IN THE GRIDS WITH SLIGHT CHANCE POPS GONE BY 01-02Z OR SO IN THE SOUTHEAST ZONES. THE FOCUS THEN WILL TURN TO THE FOG DEVELOPMENT. SKIES ARE EXPECTED TO CLEAR (OR AT LEAST BECOME MOSTLY CLEAR)...ESPECIALLY AFTER 06Z TONIGHT...AND WITH LIGHT WINDS AT 6 KNOTS OR LESS AND SATURATED GROUNDS...THE STAGE WILL BE SET FOR FOG FORMATION AS TEMPERATURES FALL INTO THE MID TO UPPER 30S. WILL BE ADDING AREAS OF FOG TO THE GRIDS FOR THE 09-14Z TIME FRAME. ON FRIDAY...ONCE THE FOG CLEARS (IF IT DEVELOPS AS FORECAST) SHORTWAVE RIDGING WILL ADVANCE ON THE WESTERN PLAINS FROM THE ROCKIES. THE LOW LEVEL RIDGE AXIS WILL REMAIN OVER WESTERN KANSAS THROUGH THE DAY FRIDAY AND THIS WILL YIELD LIGHT WINDS ALL DAY AT 6 KNOTS OR LESS. LOW LEVEL THICKNESSES WILL STILL BE FAIRLY LOW WITH THE UPPER LOW NOT ALL THAT FAR REMOVED FROM THE PLAINS...SO TEMPERATURES WILL MAX OUT IN THE MID 60S FOR MOST LOCATIONS...AND LOWER 70S ACROSS FAR SOUTHWEST ZONES WHERE THICKNESSES WILL BE INCREASING AT A QUICKER RATE WITH THE SHORTWAVE RIDGE APPROACHING. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 131 PM CDT THU MAR 22 2012 MUCH WARMER AIR WILL RETURN TO WESTERN KANSAS FRIDAY AS THE UPPER-LEVEL LOW DISCUSSED IN THE SHORT TERM DISCUSSION MOVES INTO MISSOURI AND SUNSHINE RETURNS. HIGHS SHOULD WARM INTO THE LOWER TO MID 70S. THE WARM TEMPERATURES WILL PERSIST THROUGH NEXT WEEK AS UPPER-LEVEL TROUGHING DEVELOPS ACROSS THE WESTERN UNITED STATES, AND SURFACE LEE TROUGHING DEVELOPS ACROSS THE HIGH PLAINS. A SHORTWAVE TROUGH WILL PASS ACROSS THE NORTHERN PLAINS BY MONDAY NIGHT AND TUESDAY. THE GFS/GEM AND ECMWF WERE GENERALLY FOLLOWED WITH THIS SYSTEM. DESPITE SOME SUBTLE MODEL DIFFERENCES, THE BOTTOM LINE IS THAT THE UPPER-LEVEL SYSTEM WILL PASS TO OUR NORTH, WITH LITTLE IN THE WAY OF SYNOPTIC SCALE LIFT OVER WESTERN KANSAS. TEMPERATURES COULD POSSIBLY REACH INTO THE MID 80S BEHIND THE DRYLINE IN FAR WESTERN KANSAS MONDAY. RICH LOW-LEVEL MOISTURE WILL BE DRAWN NORTHWARD ALONG AND EAST OF THE 100TH MERIDIAN IN ADVANCE OF THE SYSTEM. OFTENTIMES IN MARCH, STRONG FRONTS PUSH THE LOW-LEVEL MOISTURE DEEP INTO THE TROPICS. BUT SO FAR THIS MARCH WE HAVE HAD NO PROBLEM GETTING RICH MOISTURE BACK FROM THE GULF IN THE ABSENCE OF STRONG FRONTAL PASSAGES. A DRYLINE WILL SET UP ACROSS WESTERN KANSAS MONDAY, WITH AN UNSTABLE AIRMASS DEVELOPING IMMEDIATELY AHEAD OF IT. HOWEVER, THUNDERSTORMS MAY NOT DEVELOP SINCE THE ASSOCIATED UPPER-LEVEL JET AND MID-LEVEL COOLING WILL PASS TO OUR NORTH. BUT AN ISOLATED LATE DAY THUNDERSTORM CANNOT BE COMPLETELY RULED OUT. AFTER THIS SYSTEM PASSES, THE ASSOCIATED WEAK COLD FRONT WILL MOVE THROUGH SOUTHWEST KANSAS, KNOCKING TEMPERATURES DOWN ONLY A FEW DEGREES. IN FACT, TEMPERATURES OUGHT TO REMAIN ABOVE CLIMATOLOGICAL AVERAGES ALL WEEK AS LEE TROUGHING QUICKLY REDEVELOPS GIVEN THE FAIRLY ZONAL MID-LEVEL FLOW. A THUNDERSTORM OR TWO COULD DEVELOP ALONG THE TRAILING COLD FRONT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1220 AM CDT FRI MAR 23 2012 NORTHERLY WINDS WILL BECOME LIGHT AND VARIABLE EARLY THIS MORNING AS AN UPPER LEVEL SYSTEM MOVES INTO THE MISSISSIPPI VALLEY. VFR CONDITIONS WILL PREVAIL WITH CLOUDS AOA050 DISSIPATING BEFORE SUNRISE. LIGHT AND VARIABLE WINDS CONTINUE THROUGH THE AFTERNOON WITH MOSTLY CLEAR SKIES. && .PRELIMINARY POINT TEMPS/POPS... DDC 41 74 48 78 / 0 0 0 0 GCK 40 76 48 79 / 0 0 0 0 EHA 42 77 48 80 / 0 0 0 0 LBL 41 77 48 79 / 0 0 0 0 HYS 41 76 48 77 / 0 0 0 0 P28 43 74 48 77 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...UMSCHEID LONG TERM....FINCH AVIATION...HOVORKA 42
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1010 PM MDT THU MAR 22 2012 .UPDATE... ISSUED AT 932 PM MDT THU MAR 22 2012 NUDGED POPS UP TO CHANCE CATEGORY ALONG AND WEST OF THE CO/KS STATE LINE...MAINLY NORTH OF THE INTERSTATE...PER RADAR IMAGES AND LATEST HRRR WHICH HAS A GOOD HANDLE ON CURRENT LOCATION OF PRECIPITATION. NO OTHER CHANGES MADE. UPDATE ISSUED AT 830 PM MDT THU MAR 22 2012 UPDATED TONIGHT THROUGH FRIDAY PERIODS. MAIN ADJUSTMENT WAS TO INCREASE CLOUD COVER AROUND AN UPPER LOW PRESSURE CENTER CURRENTLY OVER NORTH CENTRAL OKLAHOMA. AS THIS LOW MOVES EAST-NORTHEAST TOWARD SOUTHERN MISSOURI FRIDAY CONSIDERABLE WRAPAROUND CLOUDINESS WILL IMPACT THE WESTERN 1/2-1/3 OF THE AREA THROUGH FRIDAY MORNING BEFORE DECREASING IN COVERAGE DURING THE AFTERNOON AS AVAILABLE MOISTURE DECREASES. AT 0230Z RADAR STILL SHOWING A FEW ECHOES ACROSS FAR WESTERN YUMA AND KIT CARSON COUNTIES WHERE SOME LIGHT RAIN SHOWERS ARE FALLING. THIS AREA OF PRECIPITATION CONTINUES TO SLOWLY LOSE ITS INTENSITY AND AM THINKING THAT BY 06Z OR 09Z AT THE LATEST IT SHOULD BE WEAK ENOUGH TO REMOVE POP MENTION. NO CHANGES MADE TO THE FOG FORECAST EARLY FRIDAY MORNING THROUGH MID MORNING. WINDS LIGHT THROUGH THE NEXT 36 HOURS OR SO. HIGH TEMPERATURES STILL LOOK TO WARM CLOSE TO 70 DEGREES FOR MANY. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 232 PM MDT THU MAR 22 2012 VISIBLE SATELLITE IMAGERY SHOWS CENTER OF LOW JUST SOUTHEAST OF KP28. A BAND OF LIGHT SHOWERS ON THE NORTHWEST SIDE OF LOW WILL PERSIST ACROSS THE EASTERN COLORADO COUNTIES THROUGH THE EVENING. AS THE LOW SLOWLY MOVES EAST...MOISTURE ADVECTION/SHOWERS WILL END. LOW WILL BE FAR ENOUGH EAST BY 12Z FRIDAY THAT CLOUDS WILL BE ALSO DECREASE. HOWEVER...THE BOUNDARY LAYER IS QUITE MOIST AFTER WIDESPREAD RAIN LAST NIGHT...SO AS CLEARING/SURFACE COOLING TAKES PLACE...FOG WILL FORM. HARD TO PINPOINT EXACTLY WHERE FOG IS MOST LIKELY TO DEVELOP...BUT WILL BEGIN BY INTRODUCING IT ACROSS THE WESTERN HALF OF FORECAST AREA AROUND 08Z. EXPECT TEMPERATURES TO DROP INTO THE MID 30S MOST AREAS TONIGHT. MODELS AGREE THAT 500 MB RIDGE WILL BUILD OVER THE HIGH PLAINS FRIDAY AFTERNOON. WARM AIR ADVECTION WILL BEGIN AFTER 18Z...WITH 850 MB TEMPERATURES REACHING 16-18 DEGREES CELSIUS. THUS...EXPECT MAXIMUM TEMPERATURES TO REACH INTO THE UPPER 60S UNDER MOSTLY SUNNY SKIES. THERE MAY BE FOG AGAIN FRIDAY NIGHT...BUT WILL SEE HOW FOG FORMS TONIGHT BEFORE INTRODUCING IT AGAIN. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 232 PM MDT THU MAR 22 2012 A HIGHLY AMPLIFIED RIDGE WILL BE IN PLACE ACROSS THE CENTRAL US SATURDAY THROUGH MONDAY WITH VERY WARM TEMPERATURES AND DRY CONDITIONS EXPECTED. HIGH TEMPERATURES WILL GENERALLY RANGE FROM THE UPPER 70S TO LOW 80S...WITH AFTERNOON TEMPERATURES POSSIBLY WARMING INTO THE MIDDLE 80S ON MONDAY. BY MONDAY NIGHT A SHORTWAVE TROUGH WILL PASS ACROSS THE NORTHERN PLAINS...WITH AN ASSOCIATED COLD FRONT DROPPING SOUTH OVER THE CWA LATE MONDAY NIGHT. WITH A DRY LINE LINGERING OVER THE CWA AND DECENT INSTABILITY EAST OF THIS FEATURE MONDAY AFTERNOON THROUGH MONDAY NIGHT...A FEW THUNDERSTORMS COULDNT BE RULED OUT OVER EASTERN LOCATIONS. I STILL HAVE CONCERNS THAT A STRONG CAP IN PLACE ACROSS OUR CWA WILL LIMIT CONVECTIVE POTENTIAL...AND THE OVERALL TREND WITH GUIDANCE HAS BEEN TO PUSH THE BEST CHANCES FURTHER EAST. OVERALL THE SYNOPTIC PATTERN HAS BEEN FAIRLY CONSISTENT...SO I DECIDED TO KEEP SLIGHT CHANCE POPS IN THE EXTREME EASTERN PART OF OUR CWA FOR ANOTHER FORECAST CYCLE. IF CURRENT TRENDS HOLD THESE POPS COULD PROBABLY BE REMOVED. TUESDAY THROUGH THURSDAY...A MORE PROGRESSIVE PATTERN SETS IN BY THE MIDDLE OF NEXT WEEK. HOWEVER...THE MAIN STORM TRACK REMAINS FAR TO THE NORTH...SO DRY CONDITIONS SHOULD CONTINUE ACROSS THE TRI-STATE REGION. TEMPERATURES OVER THE CWA WILL BE SLIGHTLY COOLER AFTER THE RIDGE BREAKS DOWN MONDAY NIGHT...HOWEVER THEY WILL REMAIN ABOVE NORMAL WITH HIGHS GENERALLY IN THE UPPER 60S/LOW 70S ACROSS && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1010 PM MDT THU MAR 22 2012 VFR EXPECTED THROUGH THE PERIOD AT KGLD AND KMCK. VARIABLE WINDS 6 KTS OR LESS EXPECTED THROUGH 00Z BEFORE BECOMING S/SE AROUND 7KTS. MAY SEE SOME FOG AND CIGS 1500-2500 FT AT KGLD EARLY FRIDAY MORNING GIVEN THE LIGHT WINDS AND RECENT RAINFALL. OTHERWISE...AT KGLD EXPECTING CLOUDS BETWEEN 5-10K FT AS WRAPAROUND CLOUDINESS ON THE BACK SIDE OF AN UPPER LEVEL LOW PRESSURE AREA MOVES ACROSS THE AREA TONIGHT THROUGH FRIDAY MORNING. && .FIRE WEATHER... ISSUED AT 232 PM MDT THU MAR 22 2012 RH VALUES WILL APPROACH CRITICAL LEVELS EACH AFTERNOON FROM SATURDAY THROUGH NEXT WEDNESDAY...PRIMARILY OVER WESTERN PARTS OF OUR FORECAST AREA. THERE ARE STILL QUESTIONS REGARDING WHETHER WINDS WILL FALL WITHIN RED FLAG CRITERIA EACH AFTERNOON. THE GUSTIEST WINDS ARE CURRENTLY EXPECTED SUNDAY AND MONDAY. AT THIS TIME THE THE BEST CHANCE FOR RED FLAG CRITERIA TO BE MET STILL LOOKS TO BE ON MONDAY AFTERNOON...WITH WITH WIND GUSTS AROUND 30 MPH AND RH VALUES IN THE 15-20 PERCENT RANGE. ANOTHER FACTOR TO CONSIDER WILL BE THE EFFECT OF OUR RECENT RAINFALL ON FUELS. AFTER SEVERAL VERY WARM/DRY AFTERNOONS FUELS WILL LIKELY BE FAVORABLE...ESPECIALLY BY SUNDAY/MONDAY AFTERNOONS. IT IS STILL TOO EARLY TO ISSUE A WATCH/WARNING FOR THESE PERIODS...SO THE SITUATION WILL CONTINUE TO BE MONITORED. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...NONE. KS...NONE. NE...NONE. && $$ UPDATE...007 SHORT TERM...MENTZER LONG TERM....DR AVIATION...007
AREA FORECAST DISCUSSION
NWS PADUCAH KY
939 PM CDT SAT MAR 24 2012 .UPDATE... ISSUED AT 930 PM CDT SAT MAR 24 2012 NEEDED TO UPDATE NEAR TERM RAIN CHCS /TONIGHT/ FOR PERSISTENT BAND/CLUSTER OF SHOWERS HEADING SOUTH THROUGH THE WABASH RIVER VALLEY. ALSO...STILL STUBBORN ACTIVITY FROM TIME TO TIME IN SE MO. HRRR/4.0 KM WRF HAVE CAUGHT ONTO THESE TRENDS. HOWEVER...THE 12Z WRF MODEL TAKES THAT WABASH RIVER VALLEY ACTIVITY A BIT FURTHER WEST INTO OUR FA OVERNIGHT AS OPPOSED TO THE HRRR RUN. WILL TRY TO SPLIT THE DIFFERENCE AND GO WITH LIKELY POPS FOR LOW QPF AMOUNTS UP IN SW INDIANA AND ALONG THE WABASH RIVER...THEN CONTINUE HIGH CHC POPS SOUTHWARD INTO THE NRN PENNYRILE OF KY BEFORE SLOWLY DIMINISHING AFTER 07-09Z. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 258 PM CDT SAT MAR 24 2012 ANY LINGERING SHOWERS ACROSS SOUTHEAST AND SOUTHERN PORTIONS OF THE PAH FORECAST AREA SHOULD TAPER OFF AND MOVE OUT OF THE REGION BY SUNSET WITH THE UPPER LOW FINALLY MAKING ITS WAY FARTHER EAST. CLOUDS WILL SLOWLY DECREASE FROM WEST TO EAST TONIGHT. A UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD INTO THE SOUTHERN PLAINS INTO EARLY NEXT WEEK. DESPITE NORTH TO NORTHEAST WINDS...PLENTY OF SUNSHINE ON SUNDAY AND MONDAY WILL HELP TEMPERATURES REACH THE LOWER TO MIDDLE 70S ON SUNDAY AND MONDAY. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 258 PM CDT SAT MAR 24 2012 GFS AND ECMWF SHOW THE UPPER LEVEL RIDGE SLIDING EAST AND GRADUALLY BREAKING DOWN BY MID WEEK. WINDS WILL BECOME SOUTHERLY BY TUESDAY...AND THE ALREADY ABOVE NORMAL TEMPERATURES WILL GET A EVEN WARMER FOR TUESDAY AND WEDNESDAY. GFS AND ECMWF ARE IN PRETTY DECENT AGREEMENT BRINGING A COLD FRONT DOWN TO THE OHIO RIVER BY 18Z WEDNESDAY. SLIGHT TO LOW CHANCE POPS LATE TUESDAY NIGHT ACROSS THE NORTHERN THIRD OF THE PAH FA WILL SPREAD SOUTH ACROSS THE ENTIRE AREA WEDNESDAY. THE FRONT WILL SLIDE A LITTLE FARTHER SOUTH...THEN IT WILL MEANDER ACROSS OR JUST SOUTH OF THE AREA INTO THURSDAY. BY THURSDAY NIGHT...GFS TAKES THE FRONT EVEN FARTHER SOUTH...REMOVING ANY QPF FROM THE REGION...WHILE ECMWF BRINGS THE FRONT BACK NORTH...WHICH KEEPS SHOWER AND THUNDERSTORM CHANCES GOING INTO FRIDAY AND SATURDAY AS ANOTHER LOW PRESSURE SYSTEM MOVES UP FROM THE SOUTHERN PLAINS. BOTH MODELS HAVE BEEN ALTERNATELY SHOWING THESE TYPES OF SOLUTIONS...AND FOR NOW WE WILL KEEP SLIGHT TO LOW CHANCE POPS GOING THROUGH THE END OF THE FORECAST PERIOD. THOUGH THE POSITIONING OF THE FRONT MAKES TEMPERATURES A LITTLE MORE UNCERTAIN...CONDITIONS WILL REMAIN UNSEASONABLY WARM. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY) ISSUED AT 651 PM CDT SAT MAR 24 2012 TAF SITES SHOULD REMAIN VFR TONIGHT WITH LIGHT NNW WINDS BECOMING VARIABLE OR CALM AFTER SUNSET. WILL SEE PATCHY LOW VFR CIGS 4-5 KFT AR TIMES...ESP AT KEVV/KOWB SITES. CIGS COULD FALL INTO THE MVFR CATEGORY DURING THE DAY SUNDAY AS ANOTHER BAND OF MOISTURE WRAPS AROUND THE STRONG UPPER LOW MOVING OFF INTO THE SE UNITED STATES REGION. THINKING IS THAT THE CIGS WILL STAY AOA 2 KFT THO. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...GM SHORT TERM...RST LONG TERM....RST AVIATION...CW
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1231 AM CDT FRI MAR 23 2012 .UPDATE... ISSUED AT 1158 PM CDT THU MAR 22 2012 MAIN CHALLENGE THIS EVENING AND INTO THE OVERNIGHT HOURS HAS BEEN THE THE VARIABILITY OF CLOUD COVER BETWEEN THE CONVECTIVE BANDS ROTATING AROUND THE CLOSED COLD CORE UPPER LOW MOVING INTO SOUTHWEST MO. THE SHORT TERM NUMERICAL MODEL SUITE /4KM NAM-WRF ARW AND NMM...AS WELL AS THE 3KM HRRR AND 12KM NAM-WRF/ STILL SUGGEST THAT MOST OF THE WFO PAH FORECAST AREA WILL REMAIN OUT OF THE PRECIPITATION...WITH THE EXCEPTION OF SOUTHEAST MO BETWEEN 09-12Z FRIDAY. WITH THE CLEAR SKIES...FOG WILL BE AN INTERMITTENT PROBLEM OVERNIGHT. SOME OF THE FOG WILL REMAIN QUITE SHALLOW /GROUND FOG/...WHILE DEEPER MORE PERSISTENT FOG WILL DEVELOP LATER TONIGHT ALONG THE EDGE OF THE RECEDING OPAQUE CLOUD COVER. THE GRIDDED FORECAST HINTS AT THE AREAS WITH THE GREATER POTENTIAL FOR DENSE FOG...BUT LIGHT FOG AND/OR GROUND FOG WILL BE POSSIBLE ACROSS MOST AREAS UNDER THE CLEARING SKIES OVERNIGHT. A SPECIAL WEATHER STATEMENT WAS ISSUED FOR PARTS OF SOUTHEAST MISSOURI AND ALL OF SOUTHERN ILLINOIS FOR FOG DEVELOPMENT. AN INITIAL LOOK AT THE FRIDAY CONVECTIVE ACTIVITY SUGGESTS A FAIR AMOUNT OF MULTICELL DEVELOPMENT WITH THE MAIN ROTATING SHEAR AXES AHEAD OF THE COLD CORE LOW CIRCULATION. THE NAM-WRF SUGGESTS A QUICK TURNAROUND IN THE EXPENDITURE OF CAPE...WITH BANDING OF PRECIPITATION A LIKELY SCENARIO. THE BIG KEY WILL BE THE AMOUNT OF DESTABILIZATION OF THE BOUNDARY LAYER DURING THE MORNING HOURS. THIS MAY SLOW THE ONSET OF SIGNIFICANT PARCEL MIXING OVER SOUTHERN IL/WESTERN KY UNTIL LATER IN THE MORNING /POSSIBLY AFTER 16Z/. BY THAT TIME...SUFFICIENT SHEAR AND SHARPER LAPSE RATES SHOULD LEAD TO BETTER UPDRAFTS CAPABLE OF HAIL. I WOULD NOT BE SURPRISED TO SEE SOME 1-1.5 INCH HAIL IN LOCAL CASES...BUT MOST HAIL SHOULD REMAIN IN THE 0.25-0.75 INCH SIZE CATEGORY. THE 4KM NAM-WRF /ARW VERSION/ HINTED THAT SERN IL AN SWRN IN COULD SEE BETTER UPDRAFT FOR SEVERE CRITERIA WIND/HAIL IN THE 17Z-22Z TIME FRAME. WILL JUST HAVE TO WAIT AND SEE. AGAIN...THE KEY WILL BE THE DEGREE OF INSOLATION /SUNSHINE/ AND LACK OF CLOUD COVER TO SUPPORT SURFACE- BASED PARCEL LIFT. UPDATE ISSUED AT 710 PM CDT THU MAR 22 2012 MINOR VORTICITY LOBE/CENTER APPEARED TO BE GENERATED OVER SOUTHWEST KY/EXTREME SOUTHERN IL NEAR KPAH BETWEEN 5-6 PM CDT. THIS FEATURE...WELL DEPICTED BY THE 3KM HRRR 1KM AGL REFLECTIVITY SHOULD CONTINUE TO MOVE NORTHEAST THROUGH 10 PM ACROSS SOUTHERN IL. THERE MAY BE SOME REGENERATION OF PRECIPITATION AS THIS FEATURE MOVE NEAR THE CONFLUENCE OF THE WABASH/OHIO RIVERS NEAR SOUTHWEST INDIANA EARLY THIS EVENING. KEPT A MENTION OF POP/WEATHER IN THIS AREA...BUT MAY NEED TO RE-ADJUST AS THE BOUNDARY LAYER STABILIZES AND A WEAK LLJ SET UP. ABUNDANT MOISTURE NEAR THE SURFACE AND A STABILIZING BOUNDARY LAYER WILL LIKELY LEAD TO SOME FOG GENERATION AFTER MIDNIGHT. AT THE CURRENT TIME...THE MENTION OF FOG IS WELL COVERED...BUT PLAN TO SEE WHERE THE GREATEST VISIBILITY RESTRICTIONS WILL BE FOR THE MID-EVENING UPDATE. WITH THE UPPER LOW AND SHARPER LAPSE RATES APPROACHING WITH THE SOUTHWEST MO CONVECTIVE ACTIVITY...KEPT A NARROW BAND OF ISOLATED TO SCATTERED THUNDERSTORMS MENTIONED OVER THE WESTERN FOUR COUNTIES OF SOUTHEAST MO THIS EVENING /MAINLY POPLAR BLUFF-GREENVILLE WESTWARD/. PLAN TO HAVE A LITTLE MORE DETAILED LOOK AT THUNDERSTORM/HAIL/WIND POTENTIAL FOR FRIDAY. THE CURRENT SPC OUTLOOK AREA FOR DAY 2 LOOKS FAIRLY GOOD...WITH THE TIME OF GREATEST CONCERN LIKELY RANGE BETWEEN 16Z-22Z /11 AM -5 PM CDT/ ALONG AND EAST OF A KPAH-KSAR- KMVN LINE. && .SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT) N-S BAND OF SHOWERS SHIFTING SLOWLY TO THE EAST...A LITTLE FASTER THAN ORIGINALLY EXPECTED...SO FRONTAL BOUNDARY OBVIOUSLY ON THE MOVE. SOME DEVELOPMENT WEST OF THE MAIN BAND...BUT NOT FILLING IN TOO WELL AT THE MOMENT. MAIN BAND OF PRECIP SHOULD CONTINUE ITS EASTWARD MOVEMENT OVERNIGHT... HOWEVER BY LATE TONIGHT THE LEADING EDGE OF PRECIP ASSOCIATED WITH THE PARENT UPPER LOW IS EXPECTED TO BE MOVING INTO THE WESTERN SECTIONS OF OUR CWA. IF SKIES REMAIN CLEAR TO MOSTLY CLEAR OVERNIGHT BETWEEN THE TWO AREAS OF PRECIP...WITH WET SOIL AND LIGHT TO CALM WINDS...AREAS OF FOG WILL LIKELY DEVELOP...SO ADDED IT. THE COMBINATION OF THE PARENT UPPER LOW MOVING ACROSS OUR CWA FRIDAY...STEEP MID LEVEL LAPSE RATES...AND COLD AIR ALOFT WILL LIKELY GENERATE THUNDERSTORM DEVELOPMENT...WITH THERE BEING A THREAT FOR LARGE HAIL PRODUCTION...ESPECIALLY ACROSS THE NORTHERN HALF OF THE CWA. FRIDAY NIGHT PRECIP CHANCES WILL DIMINISH FROM WEST TO EAST AS THE UPPER MOVES FARTHER AWAY FROM OUR CWA. .LONG TERM...(SATURDAY THROUGH THURSDAY) SHOWERS WILL LINGER ACROSS THE LOWER OHIO VALLEY ON SATURDAY AS THE UPPER LOW SLIDES SOUTHEAST ACROSS NORTHEAST PORTIONS OF THE PADUCAH FORECAST AREA. DUE TO THE PROXIMITY OF THE LOW...THUNDERSTORMS WILL REMAIN POSSIBLE ACROSS THE EASTERN THIRD OF THE FA...WITH SOME SMALL HAIL NOT OUT OF THE QUESTION. BY SATURDAY NIGHT...JUST A FEW SHOWERS WILL BE POSSIBLE ACROSS EASTERN THIRD OF THE FA. AN UPPER LEVEL RIDGE WILL BUILD ACROSS THE SOUTHERN PLAINS SUNDAY AND SLIDE EAST INTO EARLY NEXT WEEK. THIS WILL KEEP CONDITIONS DRY WITH TEMPERATURES 10 TO 15 DEGREES ABOVE NORMAL. GFS AND ECMWF SHOW A LOW PRESSURE SYSTEM SLIDING FROM THE NORTHERN PLAINS INTO THE NORTHERN GREAT LAKES REGION LATE TUESDAY INTO WEDNESDAY. THIS LOW WILL BRING A COLD FRONT INTO THE AREA TUESDAY NIGHT INTO THURSDAY. BOTH MODELS PRODUCE QPF...THOUGH GFS PRODUCES MORE SIGNIFICANT QPF TUESDAY NIGHT INTO WEDNESDAY NIGHT...WHILE THE ECMWF HOLDS OFF ON A LITTLE MORE SUBSTANTIAL QPF UNTIL THURSDAY WHEN IT BRINGS THE FRONT BACK NORTH. IN EITHER CASE...AT LEAST SOME CHANCE POPS LOOK REASONABLE ACROSS NORTHERN PORTIONS OF THE FA TUESDAY NIGHT...AND ACROSS THE ENTIRE FA WEDNESDAY INTO WEDNESDAY NIGHT. WENT WITH JUST SOME SMALL POPS ACROSS NORTHEAST AND SOUTHERN PORTIONS ON THURSDAY FOR NOW UNTIL MODELS BECOME MORE DEFINITIVE WITH TIMING AND FRONTAL PLACEMENT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1158 PM CDT THU MAR 22 2012 MAIN CHALLENGE WITH THE 06Z TAF ISSUANCE HAS BEEN THE ONSET OF VLIFR TO IFR CEILINGS AND VISIBILITIES ASSOCIATED WITH THE RECEDING OPAQUE CLOUD COVER. I HAVE ADJUSTED THE KCGI/KPAH TAF SITES TO ADDRESS PREVAILING HIGHER VISIBILITIES WITH INTERMITTENT GROUND FOG /MIFG/. FOR THE MAIN CONVECTIVE ACTIVITY ACROSS THE TAF SITES ON FRIDAY...ADDRESSED THESE INSTANCES WITH VFR CEILINGS AND VISIBILITIES...AS WELL AS VICINITY THUNDERSTORM CHANCES. GIVEN THE BANDED NATURE OF THE EXPECTED CONVECTION...IT WILL BE HARD TO TIME VISIBILITY AND CEILING RESTRICTIONS BEYOND 1-2 HOURS AT A TIME. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...SMITH SHORT TERM...JP LONG TERM....RST AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
720 PM CDT SAT MAR 24 2012 .UPDATE... 00Z AVIATION DISCUSSION ADDED BELOW. && .DISCUSSION... SEVERAL FEATURES OF INTEREST WILL IMPACT THE REGION OVER THE COMING WEEK... ALTHOUGH AT THIS POINT NO PARTICULARLY SIGNIFICANT WEATHER APPEARS LIKELY. IN THE BIG PICTURE... THE LARGE SCALE UPPER FLOW WILL BECOME LESS AMPLIFIED AND HENCE MORE PROGRESSIVE AND SLIGHTLY MORE SEASONABLE IN OUR NECK OF THE WOODS. THIS MEANS THAT INSTEAD OF SEEING TEMPERATURES OF 20-30 DEGREES ABOVE NORMAL... THEY MAY BE MORE ON THE ORDER OF 10-15 DEGREES ABOVE NORMAL FOR A GOOD PART OF THE UPCOMING WEEK. ONE MAJOR CONCERN COULD BE THE POTENTIAL FOR FREEZING TEMPERATURES IN THE UPCOMING WEEK... SINCE SOME OF THE CALENDAR-DEFICIENT PLANTS HAVE DECIDED IT/S ALREADY TIME TO START GROWING. IT DOESN/T APPEAR AS THOUGH ANY WIDESPREAD FREEZING TEMPERATURES WILL OCCUR THROUGH THE UPCOMING WEEK... BUT PORTIONS OF THE AREA COULD SEE READINGS DIP NEAR OR BELOW FREEZING ON A COUPLE OF MORNINGS. THE GFS AND ECMWF ARE IN DECENT AGREEMENT THROUGH MOST OF THE WEEK... SO GENERALLY FOLLOWED A BLEND OF THEIR GUIDANCE... INCREASINGLY BLENDING IT WITH THE PREVIOUS FORECAST IN THE LATER PERIODS. VISIBLE IMAGERY SHOWS THIS MORNING/S LOW CLOUDS AND FOG HAVE FINALLY BURNED OFF OVER MOST OF THE AREA. TEMPERATURES ARE RESPONDING QUICKLY TO THE SUNSHINE... WITH READINGS CLIMBING THROUGH THE 60S TO AROUND 70. SHOULD CONTINUE TO SEE READINGS WORK UPWARD THE NEXT COUPLE OF HOURS... THEN THINGS WILL COOL OFF BOTH IN RESPONSE TO DARKNESS AND THE COLD FRONT MARCHING SOUTHEAST THROUGH THE AREA. THE FRONT CURRENTLY STRETCHES FROM NEAR INTERNATIONAL FALLS SOUTHWEST INTO EASTERN SOUTH DAKOTA. TEMPERATURES DROP OFF BEHIND THE FRONT... WITH A BIG DROP IN DEWPOINTS NOTED AS WELL. A FEW SHRA COULD DEVELOP IN NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN AS THE FRONT MOVES THROUGH THIS AFTERNOON AND EVENING... BUT AT THIS POINT IT LOOKS LIKE ANY OF THAT ACTIVITY SHOULD STAY NORTH OF OUR AREA. THE HRRR AND LOCAL 4KM WRF-ARW DO MANAGE TO PRODUCE SOME LIGHT SHRA INTO THE NORTHEAST PART OF OUR AREA... BUT AT THIS POINT WOULD RATHER SEE MORE GOING ON IN THE REAL WORLD TO INCLUDE A MENTION. AS MENTIONED... THE FRONT WILL SLIDE THROUGH TONIGHT... WITH RIDGING AND COOLER/DRIER AIR ARRIVING FOR OVERNIGHT THROUGH THE DAY ON SUNDAY. BUT... GIVEN THE MORE PROGRESSIVE FLOW... THIS CHANGE WILL BE SHORT-LIVED... WITH RETURN FLOW SETTING UP QUICKLY SUNDAY NIGHT. ISENTROPIC LIFT SUNDAY NIGHT INTO MONDAY IS IMPRESSIVE AS THE ELEVATED WARM FRONT LIFTS BACK NORTHEAST ACROSS THE AREA. IN ADDITION TO THE ISENTROPIC LIFT... FAIRLY SUBSTANTIAL LOW-MID LEVEL FRONTOGENESIS IS PROGGED FROM LATE SUNDAY NIGHT THROUGH THE DAY ON MONDAY AS THE BOUNDARY SLOWLY LIFTS NORTHEAST ACROSS THE AREA. A LOOK AT ELEVATED INSTABILITY... PER 850-500MB DIFFERENTIAL THETA-E VALUES... SHOWS SOME POTENTIAL FOR THUNDER CREEPING IN FROM WEST TO EAST LATE SUNDAY NIGHT INTO MONDAY NIGHT... WITH A CHANCE FOR SOME THUNDER ACROSS THE ENTIRE AREA BY LATER MONDAY NIGHT AS THE WARM SECTOR FULLY ESTABLISHES ITSELF OVER SOUTHERN MINNESOTA INTO WEST CENTRAL WISCONSIN. EXPECT AN INITIAL ARC OF PCPN ASSOCIATED WITH ELEVATED WARM ADVECTION TO LIFT INTO THE AREA LATE SUNDAY NIGHT INTO MONDAY MORNING... THEN A SECONDARY DEVELOPMENT OF PCPN BEHIND THAT OWING TO INCREASING ISENTROPIC LIFT ALONG WITH FRONTOGENESIS AND THE ARRIVAL OF ELEVATED INSTABILITY. IN ADDITION... SOME POTENT STORMS MAY DEVELOP TO OUR WEST MONDAY AFTERNOON INTO MONDAY EVENING... AND WHAT IS LEFT OF THOSE COULD WORK INTO THE AREA MONDAY NIGHT. LOW PRESSURE IS EXPECTED TO LIFT NORTHEAST INTO NORTHWEST MINNESOTA BY TUESDAY AFTERNOON... WORKING TO DRAG A COLD FRONT EAST THROUGH OUR AREA SOMEWHAT EARLY IN THE DAY. THE FRONT LOOKS TO GET ACROSS MOST OF THE MINNESOTA CWFA BY 18Z... AND THROUGH THE WISCONSIN PORTION OF THE AREA BY MID AFTERNOON. ALTHOUGH DEEP LAYER SHEAR SHOULD STILL BE QUITE STRONG ON TUESDAY... LOW LEVEL SHEAR DOES NOT LOOK TO BE AS IMPRESSIVE AS IT DID YESTERDAY... MAINLY DUE TO THE EARLIER PROGGED ARRIVAL OF THE FRONT. THE EARLIER FROPA WOULD ALSO LIMIT INSTABILITY INTO THE AREA... WHICH IS A NEGATIVE TOWARD THE SEVERE WEATHER POSSIBILITIES. SO... AT THIS POINT... THE OVERALL SEVERE WEATHER CHANCES FROM MONDAY NIGHT THROUGH TUESDAY DO NOT APPEAR PARTICULARLY HIGH ACROSS THE AREA. BUT... IT IS STILL A FEW DAYS AWAY... SO ANY CHANGES IN THE TIMING AND POSITION OF FEATURES COULD STILL CHANGE THINGS A BIT... SO IT IS WORTH KEEPING AN EYE ON THE SITUATION. STRONG WESTERLY WINDS WILL USHER IN DRIER AIR BEHIND THE FRONT LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT... WITH 850MB TEMPERATURES OF BELOW ZERO ACTUALLY MAKING IT INTO THE AREA FOR A TIME ON WEDNESDAY INTO WEDNESDAY NIGHT. HOWEVER... THIS CHANGE WILL BE SHORTLIVED ONCE AGAIN... WITH RETURN FLOW AND WARMER AIR WORKING BACK INTO THE REGION BY LATER THURSDAY AND INTO FRIDAY. CHANCES FOR SHOWERS AND A FEW THUNDERSTORMS WILL ACCOMPANY THE RETURN OF WARMER TEMPERATURES THURSDAY INTO FRIDAY WITH PERHAPS SOME SHOWER CHANCES LINGERING INTO SATURDAY AS A SHORTWAVE MOVES BY TO OUR NORTH. && .AVIATION.../00Z TAF ISSUANCE/ COLD FRONT NEAR A STC TO RWF TO SUPERIOR LINE AT 00Z WILL BE SOUTH AND EAST OF THE AREA BY 12Z. MAIN CONCERN WITH THE FRONT ARE THE LOW MVFR CIGS COMING DOWN IN STRONG LOW LEVEL COLD ADVECTION BEHIND IT. CLOUDS HAVE HELD STRONG ON SATELLITE...SO HAVE BEEFED UP THERE APPEARANCE IN TAFS. BOTH THE RUC AND LOCAL WRF SHOW A BAND OF LOWER CLOUDS WORKING ACROSS THE AREA THIS EVENING...SO USED THESE MODELS TO TIME THE CLOUDS IN THE TAFS. ONLY CONCERN WITH THE CLOUDS FOR TONIGHT COMES FROM THE HRRR...WHICH DOES NOT BRING CLOUDS MUCH FURTHER SOUTH THAN THEIR CURRENT POSITION...BUT GIVEN DEGREE OF COLD ADVECTION...SIDED WITH THE RUC/WRF. IN ADDITION...NW WINDS BEHIND THE FRONT HAVE BEEN FAIRLY STRONG AS WELL...SO BUMPED POST FRONTAL SPEEDS UP A BIT AT ALL TERMINALS. FOR MUCH OF THE DAY SUNDAY...SKIES WILL BE CLEAR...THOUGH STRONG WARM ADVECTION WILL START TAKING SHAPE TO THE SOUTHWEST DURING THE AFTERNOON...WITH CLOUDS BEGINNING TO INCREASE LATE IN THE PERIOD. KMSP...GIVEN PERSISTENCE OF POST FRONTAL CLOUDS AND LAST SEVERAL RUC FORECASTS...BROUGHT IN A TEMPO GROUP FOR SUB 017 CIGS. IF THE RUC IS RIGHT...THIS WOULD END UP BEING A PREVAILING CIG. STRONG DRYING DEPICTED AT 925 MB BEHIND THE BAND...SO DO EXPECT SKC CONDITIONS AT ALL BUT POSSIBLY EAU BY 12Z. OTHER THAN THAT...NW WINDS WILL SLOWLY VEER TOWARD THE EAST...WITH HIGH CLOUDS SLOWLY DESCENDING TOWARD THE MID LEVELS BY THE END OF THE TAF. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ TRH/MPG
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
116 PM CDT FRI MAR 23 2012 .UPDATE...HAVE ALLOWED THE DFA TO EXPIRE AS VISIBILITY HAS IMPROVED SOMEWHAT AROUND SWRN CWA. TWIN PORTS REGION STILL LOCALLY DENSE. MNDOT WEBCAMS SHOW LOW VISIBILITY IN SOME LOCATIONS WHILE OTHERS HAVE CLEARLY IMPROVED VISIBILITY COMPARED TO EARLIER IMAGES. MAY NEED TO REISSUE DFA FOR LATER TODAY/OVERNIGHT BASED ON SATURATED NEAR SFC PROFILE/NOCTURNAL COOLING/PROXIMITY OF LAKE COLD WEDGE. LOWERED MAX TEMPS EARLIER BASED ON CLOUID COVER/PRECIP/FOG. && .PREV DISCUSSION... /ISSUED 1246 PM CDT FRI MAR 23 2012/ AVIATION...18Z TAF ISSUANCE... LIFR VSBYS AND CIGS ARE EXPECTED TO CONTINUE THROUGH TOMORROW MORNING AS A STREAM OF LOW LEVEL MOISTURE CONTINUES TO GET PUMPED IN FROM THE SE AROUND THE NRN EDGE OF A CUT OFF UPPER LOW OVER THE LOWER MS VALLEY. THE ADDED INFLUENCE OF LAKE SUPERIOR IS ALSO HELPING TO INCREASE NEAR SFC MOISTURE AND AIDING IN THE FOG PERSISTENCE. COULD SEE A COUPLE HOURS THIS AFTERNOON WHERE CIGS LIFT SLIGHTLY TO LOW-END MVFR AND VSBYS IMPROVE TO GT 3SM. THE BEST CHANCE WILL BE AROUND HYR AND BRD. A FEW LIGHT RAIN SHOWERS WILL BE LINGERING AROUND INL EARLY THIS AFTERNOON...WITH MOST OF THE WIDESPREAD PRECIP ENDING BY MID AFTERNOON. FOG RETURNS TONIGHT TO MOST TERMINALS...WITH THE BEST CHANCE OF 1/4SM OR LESS AT DLH AND HIB. SHOULD SEE RAPID IMPROVEMENT IN VSBYS BY LATE SAT MORNING. PREV DISCUSSION... /ISSUED 859 AM CDT FRI MAR 23 2012/ UPDATE...ISSUED DFA AS LATEST SFC OBS/WEBCAMS SHOW EXTENSIVE AREA OF DENSE FOG ACROSS NSHORE...TWIN PORTS...SOUTH SHORE...BRAINERD LAKES/CASS LAKE VICINITY. RUC13 SNDGS SUPPORT CONTINUATION OF MOIST INVERSION PROFILE THROUGH AT LEAST MIDDAY...IF NOT LONGER. GIVEN THE DIFFICULT NATURE OF FORECASTING THIS PARTICULAR ELEMENT...WILL NEED TO MONITOR THROUGH NEXT FEW HRS FOR UPDATES TO AREAL COVERAGE/TIMING. PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 23 2012/ AVIATION...12Z TAF ISSUANCE... WIDESPREAD LIFR/IFR CONDITIONS ARE LIKELY THROUGH LATE THIS MORNING ACROSS THE REGION DUE TO VERY LOW CIGS AND FG/BR/-RA. CONDITIONS ARE PROJECTED TO IMPROVE LATE THIS MORNING AND THIS AFTERNOON TO MORE IFR/MVFR CONDITIONS...BUT BE PREPARED FOR SOME AREAS TO HAVE LINGERING LIFR CONDITIONS. CONDITIONS SHOULD THEN WORSEN AGAIN TONIGHT TO LIFR/IFR CONDITIONS DUE TO VERY LOW CIGS AND FG. PREV DISCUSSION... /ISSUED 335 AM CDT FRI MAR 23 2012/ SHORT TERM....TODAY THROUGH SATURDAY. CURRENT RADAR IMAGERY AND SFC ANALYSIS SHOWS WEAK EAST/SOUTHEAST FLOW WITH SCT RAIN SHOWERS OVER THE CWA. A CORRIDOR OF MODERATE TO HEAVY RAIN IS FOUND ALONG THE INTERNATIONAL BORDER NEAR THE OCCLUDED FRONT THAT HAS NOW PUSHED NORTH INTO CANADA. RADAR ESTIMATED RAINFALL OVER THE PAST 48 HRS RANGES FROM A QUARTER OF AN INCH IN MOST AREAS...TO HIGHER AMOUNTS OF A HALF TO ONE INCH IN THE IRON RANGE/ARROWHEAD REGION. AT 300 AM...THE HEAVIEST AMOUNTS WERE ACROSS NORTHERN ST LOUIS/LAKE COUNTIES WHERE RADAR ESTIMATED VALUES WERE AROUND AN INCH AND A HALF. A WELL DEFINED CUT OFF LOW IS CURRENTLY SEEN ON SAT IMAGERY ROTATING OVER THE CENTRAL PLAINS...CONTINUING TO WRAP WARM HUMID AIR FROM THE GULF NORTH INTO THE WESTERN GREAT LAKES REGION. WINDS WILL REMAIN NORTHEAST OVER LAKE SUPERIOR TODAY RESULTING IN COOLER TEMPERATURES AROUND 45-50 DEGREES LAKESIDE. ELSEWHERE...ANOTHER MILD MARCH DAY IN THE 60S WITH RAIN SHOWERS/DRIZZLE WILL PREVAIL. THE LOW WILL GRADUALLY PUSH EAST INTO THE SRN INDIANA/KENTUCKY REGION THROUGH SATURDAY...ALLOWING FOR UPPER LEVEL RIDING TO BUILD INTO THE NRN PLAINS. SHORT RANGE MODELS IN AGREEMENT CLOUDS AND HIGH HUMIDITIES LINGER OVER THE NORTHLAND THROUGH SATURDAY MORNING...GRADUALLY ERODING IN THE WRN ZONES SAT AFTN. HAVE INTRODUCED FOG AND DRIZZLE TO ERN HALF OF CWA OVERNIGHT WHERE SFC-H85 PROFILES REMAIN SATURATED BUT LACK FORCING FOR SHOWERS/MEASURABLE RAINFALL. LONG TERM [SATURDAY NIGHT - THURSDAY]... THE MODELS ARE IN FAIRLY GOOD AGREEMENT...SO LEANED ON A BLEND. THE MODEL CONSENSUS IS FOR A PASSING COLD FRONT SATURDAY NIGHT...BRINGING THE NORTHLAND AND MUCH COOLER AND DRIER SUNDAY. HIGH PRESSURE SHOULD KEEP MOST OF THE REGION DRY MONDAY...BUT HAD TO INCLUDE SOME LOW POPS FOR SHOWERS AND THUNDERSTORMS ACROSS THE WESTERN AND SOUTHERN FA DUE TO THE MODELS INDICATING PCPN IN THE PLAINS FROM ORGANIZING LOW PRESSURE. THAT LOW PRESSURE SYSTEM SHOULD THEN MOVE ACROSS THE DAKOTAS INTO CENTRAL/NORTHERN MINNESOTA THROUGH TUESDAY....AND THEN OVER THE GREAT LAKES THROUGH WEDNESDAY. THE PASSAGE OF THE SYSTEM COULD BRING SHOWERS AND STORMS TO THE NORTHLAND. HIGH PRESSURE SHOULD THEN PROVIDE DRY WEATHER THURSDAY. TEMPERATURES WILL GENERALLY REMAIN ABOVE NORMAL THROUGH THE LONG TERM PERIOD. && .POINT TEMPS/POPS... DLH 42 62 35 50 / 20 10 10 10 INL 46 66 27 43 / 10 10 10 10 BRD 47 70 35 55 / 10 10 10 10 HYR 47 68 40 57 / 20 10 10 10 ASX 42 60 37 48 / 30 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...DENSE FOG ADVISORY UNTIL 10 AM CDT SATURDAY FOR LSZ121-140>148. && $$ SHORT TERM...CANNON
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1246 PM CDT FRI MAR 23 2012 .AVIATION...18Z TAF ISSUANCE... LIFR VSBYS AND CIGS ARE EXPECTED TO CONTINUE THROUGH TOMORROW MORNING AS A STREAM OF LOW LEVEL MOISTURE CONTINUES TO GET PUMPED IN FROM THE SE AROUND THE NRN EDGE OF A CUT OFF UPPER LOW OVER THE LOWER MS VALLEY. THE ADDED INFLUENCE OF LAKE SUPERIOR IS ALSO HELPING TO INCREASE NEAR SFC MOISTURE AND AIDING IN THE FOG PERSISTENCE. COULD SEE A COUPLE HOURS THIS AFTERNOON WHERE CIGS LIFT SLIGHTLY TO LOW-END MVFR AND VSBYS IMPROVE TO GT 3SM. THE BEST CHANCE WILL BE AROUND HYR AND BRD. A FEW LIGHT RAIN SHOWERS WILL BE LINGERING AROUND INL EARLY THIS AFTERNOON...WITH MOST OF THE WIDESPREAD PRECIP ENDING BY MID AFTERNOON. FOG RETURNS TONIGHT TO MOST TERMINALS...WITH THE BEST CHANCE OF 1/4SM OR LESS AT DLH AND HIB. SHOULD SEE RAPID IMPROVEMENT IN VSBYS BY LATE SAT MORNING. && .PREV DISCUSSION... /ISSUED 859 AM CDT FRI MAR 23 2012/ UPDATE...ISSUED DFA AS LATEST SFC OBS/WEBCAMS SHOW EXTENSIVE AREA OF DENSE FOG ACROSS NSHORE...TWIN PORTS...SOUTH SHORE...BRAINERD LAKES/CASS LAKE VICINITY. RUC13 SNDGS SUPPORT CONTINUATION OF MOIST INVERSION PROFILE THROUGH AT LEAST MIDDAY...IF NOT LONGER. GIVEN THE DIFFICULT NATURE OF FORECASTING THIS PARTICULAR ELEMENT...WILL NEED TO MONITOR THROUGH NEXT FEW HRS FOR UPDATES TO AREAL COVERAGE/TIMING. PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 23 2012/ AVIATION...12Z TAF ISSUANCE... WIDESPREAD LIFR/IFR CONDITIONS ARE LIKELY THROUGH LATE THIS MORNING ACROSS THE REGION DUE TO VERY LOW CIGS AND FG/BR/-RA. CONDITIONS ARE PROJECTED TO IMPROVE LATE THIS MORNING AND THIS AFTERNOON TO MORE IFR/MVFR CONDITIONS...BUT BE PREPARED FOR SOME AREAS TO HAVE LINGERING LIFR CONDITIONS. CONDITIONS SHOULD THEN WORSEN AGAIN TONIGHT TO LIFR/IFR CONDITIONS DUE TO VERY LOW CIGS AND FG. PREV DISCUSSION... /ISSUED 335 AM CDT FRI MAR 23 2012/ SHORT TERM....TODAY THROUGH SATURDAY. CURRENT RADAR IMAGERY AND SFC ANALYSIS SHOWS WEAK EAST/SOUTHEAST FLOW WITH SCT RAIN SHOWERS OVER THE CWA. A CORRIDOR OF MODERATE TO HEAVY RAIN IS FOUND ALONG THE INTERNATIONAL BORDER NEAR THE OCCLUDED FRONT THAT HAS NOW PUSHED NORTH INTO CANADA. RADAR ESTIMATED RAINFALL OVER THE PAST 48 HRS RANGES FROM A QUARTER OF AN INCH IN MOST AREAS...TO HIGHER AMOUNTS OF A HALF TO ONE INCH IN THE IRON RANGE/ARROWHEAD REGION. AT 300 AM...THE HEAVIEST AMOUNTS WERE ACROSS NORTHERN ST LOUIS/LAKE COUNTIES WHERE RADAR ESTIMATED VALUES WERE AROUND AN INCH AND A HALF. A WELL DEFINED CUT OFF LOW IS CURRENTLY SEEN ON SAT IMAGERY ROTATING OVER THE CENTRAL PLAINS...CONTINUING TO WRAP WARM HUMID AIR FROM THE GULF NORTH INTO THE WESTERN GREAT LAKES REGION. WINDS WILL REMAIN NORTHEAST OVER LAKE SUPERIOR TODAY RESULTING IN COOLER TEMPERATURES AROUND 45-50 DEGREES LAKESIDE. ELSEWHERE...ANOTHER MILD MARCH DAY IN THE 60S WITH RAIN SHOWERS/DRIZZLE WILL PREVAIL. THE LOW WILL GRADUALLY PUSH EAST INTO THE SRN INDIANA/KENTUCKY REGION THROUGH SATURDAY...ALLOWING FOR UPPER LEVEL RIDING TO BUILD INTO THE NRN PLAINS. SHORT RANGE MODELS IN AGREEMENT CLOUDS AND HIGH HUMIDITIES LINGER OVER THE NORTHLAND THROUGH SATURDAY MORNING...GRADUALLY ERODING IN THE WRN ZONES SAT AFTN. HAVE INTRODUCED FOG AND DRIZZLE TO ERN HALF OF CWA OVERNIGHT WHERE SFC-H85 PROFILES REMAIN SATURATED BUT LACK FORCING FOR SHOWERS/MEASURABLE RAINFALL. LONG TERM [SATURDAY NIGHT - THURSDAY]... THE MODELS ARE IN FAIRLY GOOD AGREEMENT...SO LEANED ON A BLEND. THE MODEL CONSENSUS IS FOR A PASSING COLD FRONT SATURDAY NIGHT...BRINGING THE NORTHLAND AND MUCH COOLER AND DRIER SUNDAY. HIGH PRESSURE SHOULD KEEP MOST OF THE REGION DRY MONDAY...BUT HAD TO INCLUDE SOME LOW POPS FOR SHOWERS AND THUNDERSTORMS ACROSS THE WESTERN AND SOUTHERN FA DUE TO THE MODELS INDICATING PCPN IN THE PLAINS FROM ORGANIZING LOW PRESSURE. THAT LOW PRESSURE SYSTEM SHOULD THEN MOVE ACROSS THE DAKOTAS INTO CENTRAL/NORTHERN MINNESOTA THROUGH TUESDAY....AND THEN OVER THE GREAT LAKES THROUGH WEDNESDAY. THE PASSAGE OF THE SYSTEM COULD BRING SHOWERS AND STORMS TO THE NORTHLAND. HIGH PRESSURE SHOULD THEN PROVIDE DRY WEATHER THURSDAY. TEMPERATURES WILL GENERALLY REMAIN ABOVE NORMAL THROUGH THE LONG TERM PERIOD. && .POINT TEMPS/POPS... DLH 49 42 62 35 / 50 20 10 10 INL 58 46 66 27 / 80 10 10 10 BRD 62 47 70 35 / 40 10 10 10 HYR 64 47 68 40 / 60 20 10 10 ASX 50 42 60 37 / 60 30 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR MNZ020-021- 025-026-033>037. WI...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR WIZ001>003. LS...DENSE FOG ADVISORY UNTIL 10 AM CDT SATURDAY FOR LSZ121-140>148. && $$ AVIATION...TENTINGER
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
859 AM CDT FRI MAR 23 2012 .UPDATE...ISSUED DFA AS LATEST SFC OBS/WEBCAMS SHOW EXTENSIVE AREA OF DENSE FOG ACROSS NSHORE...TWIN PORTS...SOUTH SHORE...BRAINERD LAKES/CASS LAKE VICINITY. RUC13 SNDGS SUPPORT CONTINUATION OF MOIST INVERSION PROFILE THROUGH AT LEAST MIDDAY...IF NOT LONGER. GIVEN THE DIFFICULT NATURE OF FORECASTING THIS PARTICULAR ELEMENT...WILL NEED TO MONITOR THROUGH NEXT FEW HRS FOR UPDATES TO AREAL COVERAGE/TIMING. && .PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 23 2012/ AVIATION...12Z TAF ISSUANCE... WIDESPREAD LIFR/IFR CONDITIONS ARE LIKELY THROUGH LATE THIS MORNING ACROSS THE REGION DUE TO VERY LOW CIGS AND FG/BR/-RA. CONDITIONS ARE PROJECTED TO IMPROVE LATE THIS MORNING AND THIS AFTERNOON TO MORE IFR/MVFR CONDITIONS...BUT BE PREPARED FOR SOME AREAS TO HAVE LINGERING LIFR CONDITIONS. CONDITIONS SHOULD THEN WORSEN AGAIN TONIGHT TO LIFR/IFR CONDITIONS DUE TO VERY LOW CIGS AND FG. PREV DISCUSSION... /ISSUED 335 AM CDT FRI MAR 23 2012/ SHORT TERM....TODAY THROUGH SATURDAY. CURRENT RADAR IMAGERY AND SFC ANALYSIS SHOWS WEAK EAST/SOUTHEAST FLOW WITH SCT RAIN SHOWERS OVER THE CWA. A CORRIDOR OF MODERATE TO HEAVY RAIN IS FOUND ALONG THE INTERNATIONAL BORDER NEAR THE OCCLUDED FRONT THAT HAS NOW PUSHED NORTH INTO CANADA. RADAR ESTIMATED RAINFALL OVER THE PAST 48 HRS RANGES FROM A QUARTER OF AN INCH IN MOST AREAS...TO HIGHER AMOUNTS OF A HALF TO ONE INCH IN THE IRON RANGE/ARROWHEAD REGION. AT 300 AM...THE HEAVIEST AMOUNTS WERE ACROSS NORTHERN ST LOUIS/LAKE COUNTIES WHERE RADAR ESTIMATED VALUES WERE AROUND AN INCH AND A HALF. A WELL DEFINED CUT OFF LOW IS CURRENTLY SEEN ON SAT IMAGERY ROTATING OVER THE CENTRAL PLAINS...CONTINUING TO WRAP WARM HUMID AIR FROM THE GULF NORTH INTO THE WESTERN GREAT LAKES REGION. WINDS WILL REMAIN NORTHEAST OVER LAKE SUPERIOR TODAY RESULTING IN COOLER TEMPERATURES AROUND 45-50 DEGREES LAKESIDE. ELSEWHERE...ANOTHER MILD MARCH DAY IN THE 60S WITH RAIN SHOWERS/DRIZZLE WILL PREVAIL. THE LOW WILL GRADUALLY PUSH EAST INTO THE SRN INDIANA/KENTUCKY REGION THROUGH SATURDAY...ALLOWING FOR UPPER LEVEL RIDING TO BUILD INTO THE NRN PLAINS. SHORT RANGE MODELS IN AGREEMENT CLOUDS AND HIGH HUMIDITIES LINGER OVER THE NORTHLAND THROUGH SATURDAY MORNING...GRADUALLY ERODING IN THE WRN ZONES SAT AFTN. HAVE INTRODUCED FOG AND DRIZZLE TO ERN HALF OF CWA OVERNIGHT WHERE SFC-H85 PROFILES REMAIN SATURATED BUT LACK FORCING FOR SHOWERS/MEASURABLE RAINFALL. LONG TERM [SATURDAY NIGHT - THURSDAY]... THE MODELS ARE IN FAIRLY GOOD AGREEMENT...SO LEANED ON A BLEND. THE MODEL CONSENSUS IS FOR A PASSING COLD FRONT SATURDAY NIGHT...BRINGING THE NORTHLAND AND MUCH COOLER AND DRIER SUNDAY. HIGH PRESSURE SHOULD KEEP MOST OF THE REGION DRY MONDAY...BUT HAD TO INCLUDE SOME LOW POPS FOR SHOWERS AND THUNDERSTORMS ACROSS THE WESTERN AND SOUTHERN FA DUE TO THE MODELS INDICATING PCPN IN THE PLAINS FROM ORGANIZING LOW PRESSURE. THAT LOW PRESSURE SYSTEM SHOULD THEN MOVE ACROSS THE DAKOTAS INTO CENTRAL/NORTHERN MINNESOTA THROUGH TUESDAY....AND THEN OVER THE GREAT LAKES THROUGH WEDNESDAY. THE PASSAGE OF THE SYSTEM COULD BRING SHOWERS AND STORMS TO THE NORTHLAND. HIGH PRESSURE SHOULD THEN PROVIDE DRY WEATHER THURSDAY. TEMPERATURES WILL GENERALLY REMAIN ABOVE NORMAL THROUGH THE LONG TERM PERIOD. && .POINT TEMPS/POPS... DLH 54 42 61 38 / 50 10 10 10 INL 60 46 63 31 / 80 10 20 10 BRD 66 47 69 38 / 40 10 10 10 HYR 64 47 68 42 / 60 10 10 10 ASX 51 42 59 39 / 60 10 20 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR MNZ020-021- 025-026-033>037. WI...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR WIZ001>003. LS...NONE. && $$ SHORT TERM...CANNON
AREA FORECAST DISCUSSION
NWS HASTINGS NE
354 PM CDT FRI MAR 23 2012 .SHORT TERM...THROUGH SATURDAY AFTERNOON. NEEDLESS TO SAY...THE NEXT 24 HOURS CONTINUE THE RETURN TO INCREDIBLY NICE LATE MARCH WEATHER...WITH HIGH TEMPS ON SATURDAY FORECAST TO BE RIGHT AROUND CLIMATOLOGICAL NORMALS FOR LATE MAY/EARLY JUNE. STARTING OFF AT 20Z THIS AFTERNOON...A LIGHT AND SOMEWHAT VARIABLE WIND REGIME IS IN PLACE ACROSS THE CWA...THANKS TO A BROAD DIFFUSE RIDGE AXIS. THE COMBINATION OF MODEST BOUNDARY LAYER MOISTURE...ALONG WITH SOME COOLER MID LEVEL AIR ON THE BACK SIDE OF THE DEPARTING CLOSED LOW OVER SOUTH CENTRAL MISSOURI...HAS RESULTED IN A LEGITIMATE SCATTERED FAIR WEATHER CUMULUS FIELD ESPECIALLY ACROSS THE EASTERN HALF OF THE CWA. ALTHOUGH THIS SCATTERED TO LOCALLY BROKEN DECK WAS A BIT MORE CLOUD COVER THAN EARLIER EXPECTED...TEMPS HAVE HAD STILL HAD NO PROBLEMS MAKING IT INTO AT LEAST THE MID-UPPER 60S AT THIS HOUR...WITH SOME PLACES POSSIBLY TOUCHING 70 BY DAYS END. AS MENTIONED...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CLEARLY REVEAL THE DEPARTING CLOSED LOW AS THE MAIN MID/UPPER FEATURE OF INTEREST...WITH SHORTWAVE RIDGING NOW BUILDING ALONG AN AXIS FROM THE SOUTHERN ROCKIES TO NORTHERN PLAINS...AND THE NEXT LOW PRESSURE SYSTEM OF INTEREST STILL WELL OFF THE PACIFIC COAST. FOR LATE THIS AFTERNOON...HAVE KEPT THE FORECAST DRY...ALTHOUGH THE HRRR CONTINUES TO INSIST THAT A FEW SPRINKLES COULD FLIRT WITH FAR SOUTHEAST EDGES OF THE CWA. BASED ON LATEST VIS SATELLITE TRENDS...ANY SLIGHTLY ENHANCED CUMULUS GROWTH POTENTIALLY CONDUCIVE TO SPRINKLES/LIGHT RAIN SHOULD REMAIN JUST EAST OF THESE COUNTIES. THIS EVENING/TONIGHT...BOUNDARY LAYER CUMULUS DEVELOPMENT SHOULD QUICKLY FADE AWAY...RESULTING IN ESSENTIALLY CLEAR SKIES AS SHORTWAVE RIDGING CONTINUES TO NOSE OVERHEAD IN THE WAKE OF THE DEPARTING LOW...WHICH WILL BE NEAR THE IL/IN/KY BORDER AREA BY 12Z. BREEZES WILL REMAIN LIGHT OVERNIGHT...BUT THE DIRECTION WILL PREVAIL FROM THE WEST/SOUTHWEST. ONLY POTENTIAL ISSUE IS FOG DEVELOPMENT OVERNIGHT. VARIOUS MODEL BOUNDARY LAYER RELATIVE HUMIDITY PROGS...ALONG WITH MET/MAV VISIBILITY GUIDANCE...SUGGEST THAT THIS LIGHT WESTERLY LOW LEVEL FLOW WILL NOT BE VERY CONDUCIVE TO FOG DEVELOPMENT. THAT BEING SAID...AT LEAST LIGHT FOG HAS DEVELOPED HERE AND THERE ACROSS THE CWA THE PAST FEW NIGHTS LARGELY DUE TO MOIST GROUND IN THE WAKE OF RECENT RAINFALL. GIVEN THAT PATCHY FOG WORDING HAS ALREADY BEEN IN THE FORECAST FOR OVER 24 HOURS NOW IN SOME AREAS...WILL LET IT RIDE...BUT WOULD BE VERY SURPRISED TO SEE MORE THAN PATCHY LIGHT VISIBILITY RESTRICTIONS. FOR LOW TEMPS...KEPT SIMILAR TO PREVIOUS FORECAST IN EASTERN ZONES...BUT BUMPED DOWNWARD A FEW DEGREES IN THE WEST...RESULTING IN A RANGE FROM MID-UPPER 30S WEST...LOW 40S CENTRAL...MID 40S SOUTHEAST. BASED ON WHAT HAPPENED THIS MORNING WITH LOWS TUMBLING INTO THE LOW 30S WEST...WOULD NOT BE SURPRISED IF TONIGHTS LOWS END UP A BIT LOWER THAN FORECAST. HOWEVER...THE LIGHT WESTERLY BREEZES SHOULD HELP HOLD THINGS UP A BIT VERSUS LAST NIGHT. SATURDAY...THE MID/UPPER PATTERN REMAINS QUITE TRANQUIL...AS THE HEART OF THE 700-500MB RIDGE BUILDS OVER THE PLAINS...WELL TO THE EAST OF THE DEEP TROUGH AXIS OFF THE PACIFIC COAST...AND THE PRIMARY 300MB JET AXIS SNAKING FROM NORTHERN CA THEN EASTWARD ACROSS SOUTHERN CANADA. AS A SURFACE HIGH PRESSURE SYSTEM WORKS INTO SOUTHERN CANADA INTO THE DAKOTAS...A VERY WEAK COLD FRONT WILL PUSH SOUTHWARD TOWARD/INTO THE NORTHWEST CWA DURING THE AFTERNOON. OTHERWISE...LIGHT SOUTHWEST BREEZES WILL PREVAIL ACROSS MOST OF THE CWA FOR THE MAJORITY OF THE DAY. WITH FORECAST SOUNDINGS A BIT DRIER IN THE BOUNDARY LAYER COMPARED TO TODAY...NOT ANTICIPATING MUCH CUMULUS DEVELOPMENT...AND IN FACT VERY LITTLE CLOUD COVER. TEMP WISE...GIVEN THE WIDESPREAD SUN AND 850MB TEMPS CLIMBING WELL INTO THE 14-17C RANGE...A NOTABLE JUMP IN AFTERNOON HIGHS IN LIKELY. DIDN/T GET TOO CARRIED AWAY...BUT NUDGED UP PREVIOUS FORECAST TOWARD HIGHER END OF MET/MAV GUIDANCE CONSENSUS...WITH MOST OF THE CWA INTO THE 78-80 RANGE. .LONG TERM...SATURDAY NIGHT THROUGH FRIDAY. WE KICK THINGS OFF SATURDAY NIGHT WITH A PROMINENT UPPER RIDGE OVER THE PLAINS AND A HIGHLY AMPLIFIED TROUGH ON ENTERING THE WEST COAST OF THE UNITED STATES. WEATHER SHOULD REMAIN DRY INTO SUNDAY THANKS TO BEING UNDER THE INFLUENCE OF NOT ONLY THE UPPER LEVEL RIDGE BUT A SURFACE RIDGE AS WELL. THERE WILL BE A SURFACE TROUGH DEVELOPING IN THE LEE OF THE ROCKIES BY SUNDAY NIGHT WITH A HEALTHY FAIRLY STRONG LOW-LEVEL JET INCREASING OVER PARTS OF WESTERN AND CENTRAL KANSAS...WITH THE NOSE OF THE JET MAKING ITS WAY INTO SOUTHERN AND CENTRAL PARTS OF THE CWA BY LATE SUNDAY NIGHT...WITH THE NAM A BIT STRONGER HERE...INDICATING A 50 KT JET...AS OPPOSED TO NEAR 40 KTS FOR THE GFS AND ECMWF. AT THIS POINT...THERE DOES NOT APPEAR TO BE ENOUGH MOISTURE TO GET ANY CONVECTION GOING...BUT IF THERE WERE...STRONG TO SEVERE THUNDERSTORMS WOULD CERTAINLY NOT BE OUT OF THE QUESTION. CONFIDENCE IS NOT HIGH ENOUGH TO INTRODUCE CHANCES OF RAIN AT THIS POINT. A POTENT NEGATIVELY TILTED SHORTWAVE TROUGH WILL EJECT NORTHEAST OUT OF THE CENTRAL ROCKIES MONDAY NIGHT AND HAS BEEN PROJECTED TO DO SO FOR SOME TIME. THERE ARE SOME STRENGTH AND TIMING DIFFERENCES BETWEEN MEDIUM TO LONG RANGE MODELS...BUT THE GENERAL SCENARIO IS SIMILAR. THE ECMWF CONTINUES TO PROJECT A STRONGER WAVE THAT EJECTS INTO THE PLAINS SOONER THAN THE GFS SOLUTION. SURFACE PRESSURE GRADIENTS WILL INCREASE ALONG WITH INCREASED MIXING AND WE COULD BE GETTING CLOSE TO WIND ADVISORY WITH HEALTHY WIND FROM THE SOUTH...ESPECIALLY IN THE WESTERN CWA. MODELS GENERALLY PRODUCE THE NOSE OF THE LOW-LEVEL JET WELL NORTH OF THE CWA...ALONG WITH THE BEST MID TO UPPER LEVEL FORCING TO THE NORTH AS WELL. AT THE SURFACE...BY MONDAY EVENING...THE DRY LINE SHOULD STILL BE WELL TO THE WEST OF THE CWA...WHILE A WARM FRONT IS EXPECTED TO HAVE PASSED TO THE NORTHEAST OF THE CWA BY THEN. SEVERE PARAMETERS SUGGEST POSSIBLE SEVERE WEATHER NEAR THESE BOUNDARIES...BUT WE MAY WIGGLE OUT OF MOST OF THE SEVERE WEATHER BY BEING BETWEEN THESE BOUNDARIES WHILE SEVERE WEATHER INITIATES TOWARD EVENING...GIVEN THAT SOUNDINGS SUGGEST WE WILL BE TOO CAPPED TO PRODUCED MUCH OF ANYTHING IN THE REGION UNTIL LATE AFTERNOON AND QUITE LIKELY IN THE EVENING...AND FOR THIS REASON...I HAVE ALL BUT PULLED CHANCES OF PRECIPITATION FROM MONDAY AFTERNOON...SAVE PERHAPS THE FAR NORTHEASTERN CORNER OF THE CWA IF THE WARM FRONT DOES NOT GET OUT OF THE CWA FAST ENOUGH...AND HAVE LIMITED THAT SMALL AREA TO LATE AFTERNOON...DESPITE THE FACT THAT THE LATEST ECMWF PAINTS SOME QPF OVER THE NORTHWEST. THIS DOES NOT LOOK PROBABLE AS IT APPEARS THAT THE WARM FRONT SHOULD CLEAR THE CWA BEFORE CONVECTION BEGINS AND THERE IS NO OTHER FOCUS FOR CONVECTION IN THE AFTERNOON TO REALLY GET THINGS GOING FROM WHAT IT LOOKS LIKE FOR NOW. THIS LOOKS LIKE A SCENARIO WHERE WE MAY WIND UP GETTING SOME NOCTURNAL HIGH PLAINS CONVECTION AS THE THETA E AXIS WILL MOVE FROM WEST TO EAST ACROSS THE CWA BETWEEN 03Z AND 08Z TUESDAY (MONDAY EVENING)...BUT THIS MAY BE MORE OF A WEAKER LEFTOVER EVENT...GIVING US ELEVATED STRONGER/HEAVY RAINER STORMS...BUT PERHAPS NO LONGER SEVERE. I AM NOT CONFIDENT ENOUGH TO PULL SEVERE POTENTIAL OUT OF THE HWO...AS TIMING DIFFERENCES COULD MAKE A HUGE DIFFERENCE...AND BEING SO FAR OUT IN THE FORECAST...IT WOULD BE PRUDENT TO KEEP SEVERE POTENTIAL MENTIONED IN THE HWO. AFTER THE WAVE PASSES MONDAY NIGHT...THERE WILL BE LITTLE MORE CHANCE OF PRECIPITATION FOR A COUPLE OF DAYS WITH RIDGING TAKING PLACE. TUESDAY COULD BE GETTING CLOSE TO RED FLAG POTENTIAL IN THE FAR WESTERN CWA WITH RELATIVE HUMIDITY POSSIBLY GETTING NEAR 20 PERCENT AND WEST WINDS APPROACHING SUSTAINED 20 MPH. THE ECMWF INDICATES A SMALL PERTURBATION RIDING THE RIDGE BY WEDNESDAY NIGHT ALONG OUR SOUTHERN FRINGE WITH PERHAPS THE AID OF SOME CONVERGENCE AT 850 MB...BUT EVEN WITH QPF ADVERTISED BY THE ECMWF...PROBABILITY OF PRECIPITATION FOR RUSSEL AND CONCORDIA ARE AROUND 20 PERCENT...AND LOWER THAN THIS IN OUR CWA TO THE NORTH. FOR THE REST OF THE EXTENDED...I LEFT LOW CHANCES OF PRECIPITATION AS FLOW COULD CONTAIN POTENTIAL SMALL WAVES OF ENERGY...ALTHOUGH TEMPERATURES WILL REMAIN WELL ABOVE NORMAL. && .PREV DISCUSSION... /ISSUED 1237 PM CDT FRI MAR 23 2012/ AVIATION...18Z KGRI TAF. A VERY QUIET 24 HOURS ANTICIPATED AVIATION WISE...WITH SURFACE BREEZES REMAINING LIGHT AND VARIABLE THROUGH THIS EVENING AND THEN TRANSITIONING TO LIGHT AND SOUTHWESTERLY INTO SATURDAY MORNING. CLOUD WISE...COULD EASILY SEE A FEW HOURS OF SCATTERED CUMULUS BASED IN THE 4000-5000 FT AGL RANGE THIS AFTERNOON...BUT THIS SHOULD DISSIPATE BY SUNSET. ONLY MINOR CONCERN IS POSSIBILITY OF LIGHT FOG DEVELOPMENT MAINLY A FEW HOURS EITHER SIDE OF SUNRISE SATURDAY MORNING...BUT THE SETUP FOR WIDESPREAD FOG DOES NOT APPEAR THAT FAVORABLE. CONFIDENCE IS LOW ENOUGH IN FOG FORMATION TO LEAVE PREVAILING VISIBILITY VFR AT THIS TIME...BUT SUPPOSE A BRIEF PERIOD OF MVFR IS NOT COMPLETELY OUT OF THE QUESTION. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM/AVIATION...PFANNKUCH LONG TERM...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1237 PM CDT FRI MAR 23 2012 .UPDATE...MADE VERY LITTLE CHANGE TO AFTERNOON FORECAST...MAINLY JUST THE USUAL MINOR TWEAKS TO WIND/SKY/DEWPOINT TRENDS. GAVE HIGH TEMPS A VERY SLIGHT NUDGE UPWARD ACROSS MOST OF THE CWA...WITH A BIT MORE COVERAGE OF READINGS AT/JUST ABOVE 70 ANTICIPATED BY MID AFTERNOON. JUST STARTING TO SEE THE FIRST SIGNS OF SHALLOW BOUNDARY LOWER CUMULUS DEVELOPMENT ACROSS MAINLY CENTRAL/SOUTHEAST PORTIONS OF THE CWA...BUT ANTICIPATE MOST AREAS TO SEE NO MORE THAN SCATTERED COVERAGE OF THESE CLOUDS...ALTHOUGH FAR SOUTHEAST AREAS AROUND BELOIT/HEBRON COULD POTENTIALLY AVERAGE PARTLY TO MOSTLY CLOUDY FOR AT LEAST A FEW HOURS WITH GREATER CUMULUS DEVELOPMENT DOWN THAT WAY. LAST FEW HRRR RUNS HAVE ACTUALLY HINTED AT SOME SPRINKLE POTENTIAL DOWN IN THESE SOUTHEAST AREAS THIS AFTERNOON...BUT AT THIS POINT EXPECTING CUMULUS TO REMAIN SHALLOW ENOUGH TO KEEP THIS AT BAY. && .AVIATION...18Z KGRI TAF. A VERY QUIET 24 HOURS ANTICIPATED AVIATION WISE...WITH SURFACE BREEZES REMAINING LIGHT AND VARIABLE THROUGH THIS EVENING AND THEN TRANSITIONING TO LIGHT AND SOUTHWESTERLY INTO SATURDAY MORNING. CLOUD WISE...COULD EASILY SEE A FEW HOURS OF SCATTERED CUMULUS BASED IN THE 4000-5000 FT AGL RANGE THIS AFTERNOON...BUT THIS SHOULD DISSIPATE BY SUNSET. ONLY MINOR CONCERN IS POSSIBILITY OF LIGHT FOG DEVELOPMENT MAINLY A FEW HOURS EITHER SIDE OF SUNRISE SATURDAY MORNING...BUT THE SETUP FOR WIDESPREAD FOG DOES NOT APPEAR THAT FAVORABLE. CONFIDENCE IS LOW ENOUGH IN FOG FORMATION TO LEAVE PREVAILING VISIBILITY VFR AT THIS TIME...BUT SUPPOSE A BRIEF PERIOD OF MVFR IS NOT COMPLETELY OUT OF THE QUESTION. && .PREV DISCUSSION... /ISSUED 450 AM CDT FRI MAR 23 2012/ SHORT TERM...TODAY THROUGH 12Z MONDAY...A PLEASANT END OF THE WEEK AND UPCOMING WEEKEND ARE IN STORE FOR THE LOCAL AREA AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE CENTRAL AND NORTHERN PLAINS BEHIND THE DEPARTING UPPER LEVEL LOW. IN THE NEAR TERM...EXPECT A FEW LIGHT SHOWERS OR SPRINKLES TO CONTINUE ACROSS THE EASTERN FRINGES OF THE FORECAST AREA THROUGH THE EARLY MORNING HOURS...WITH LITTLE TO NO ADDITIONAL ACCUMULATION EXPECTED. THIS FINAL BAND OF PRECIPITATION HAS BEEN WEAKENING FOR THE PAST SEVERAL HOURS...AND IS EXPECTED TO COMPLETELY DISSIPATE OVER THE NEXT HOUR OR TWO...WITH CLEARING SKIES EXPECTED ACROSS THE LOCAL AREA BY MID MORNING. IN THE MEANTIME...EXPECT PATCHY FOG DEVELOPMENT TO CONTINUE AHEAD OF SUNRISE...AS LIGHT WINDS AND MOIST SOILS HAVE ALREADY RESULTED IN SEVERAL OBSERVATION SITES TEMPORARILY FALLING TO BELOW 5 MILES VISIBILITY THE PAST FEW HOURS. WHILE WIDESPREAD DENSE FOG IS NOT EXPECTED...WOULD NOT BE SURPRISED TO SEE SOME PATCHY DENSE FOG...ESPECIALLY IN LOW LYING AREAS...TOWARDS SUNRISE. THE GOOD NEWS...HOWEVER...IS THAT ANY FOG THAT DOES DEVELOP IS EXPECTED TO BE SHORT LIVED...WITH A BEAUTIFUL AFTERNOON EXPECTED ACROSS THE REGION. WITH LIGHT WINDS...AMPLE SUNSHINE...AND REBOUNDING TEMPS ALOFT...WENT AHEAD AND NUDGED UP AFTERNOON HIGHS A COUPLE OF DEGREES...WITH MOST LOCATIONS EXPECTED TO TOP OUT NEAR 70 DEGREES...OR NEARLY 15 DEGREES ABOVE THE NORMAL HIGH FOR MID/LATE MARCH. WINDS WILL BEGIN TO SHIFT SOUTHERLY...ALBEIT REMAIN LIGHT ON SATURDAY...AS THE SURFACE RIDGE OF HIGH PRESSURE ACROSS THE REGION THIS MORNING CONTINUES TO PUSH FURTHER EAST. THIS SOUTHERLY WIND COMPONENT WILL AID IN POTENTIAL MORNING FOG DEVELOPMENT THE NEXT COUPLE OF MORNINGS...AND OPTED TO INCREASE COVERAGE OF PATCHY MORNING FOG COVERAGE FOR THE UPCOMING WEEKEND. EVEN SO...TEMPERATURES ALOFT WILL CONTINUE TO WARM...AND WITH AMPLE SUNSHINE AND GOOD MIXING EXPECTED DURING THE AFTERNOON HOURS... EXPECT HIGH TEMPERATURES TO TOP OUT NEAR 80 DEGREES BOTH AFTERNOONS. WINDS ARE NOT EXPECTED TO BE AN ISSUE ON SATURDAY...BUT DO INCREASE A BIT SUNDAY AFTERNOON IN RESPONSE TO A TROUGH OF LOW PRESSURE BUILDING TO OUR WEST. EVEN SO...RELATIVE HUMIDITIES APPEAR TO REMAIN HIGH ENOUGH THAT FIRE WEATHER CONDITIONS DO NOT APPEAR TO BE A MAJOR CONCERN AT THIS POINT IN TIME. LONG TERM...12Z MONDAY THROUGH THURSDAY. STARTING OFF THE LONG TERM...THE GFS AND THE ECMWF ARE IN FAIRLY GOOD AGREEMENT MONDAY MORNING WITH THE POSITION OF AN UPPER LEVEL TROUGH ACROSS QUEBEC AND THE EAST COAST...A RIDGE ACROSS THE CENTRAL CONUS...AND A SECONDARY TROUGH AXIS STRETCHING FROM WASHINGTON TO NEVADA. AT THE SURFACE...HIGH PRESSURE BUILDS ACROSS ONTARIO...WHILE A LOW PRESSURE SYSTEM DEVELOPS ACROSS THE NORTHERN ROCKIES. AS THE SURFACE LOW SLIDES NORTHEAST...A TIGHT PRESSURE GRADIENT WILL FORM ACROSS THE PLAINS. WITH MODELS HINTING AT SUCH A TIGHT GRADIENT...AND TO COLLABORATE WITH NEIGHBORING OFFICES...DECIDED TO INCREASE WINDS ON MONDAY AFTERNOON TO JUST NEAR WIND ADVISORY CRITERIA. BY MONDAY NIGHT...THE SECONDARY TROUGH AXIS WILL BEGIN TO SLIDE INTO THE REGION. THE LATEST RUN OF THE ECMWF HAS NOW COME INTO AGREEMENT WITH THE GFS...POSITIONING THE CLOSED OFF 500 MB LOW OVER WESTERN SOUTH DAKOTA BY MONDAY NIGHT. THUNDERSTORMS WILL REMAIN POSSIBLE DURING THE AFTERNOON AND EVENING HOURS ON MONDAY AS AMPLE MOISTURE AND MUCAPE VALUES NEAR 1500 TO 2000 J/KG REMAIN OVER THE FORECAST AREA. POSITIONING OF THE DRY LINE WILL COME INTO QUESTION AS BOTH THE GFS AND THE ECMWF KEEP THE DRY LINE TO THE WEST UNTIL AT LEAST 0Z. DECIDED TO GO WITH A MENTION OF THUNDERSTORMS DURING THE AFTERNOON HOURS...BUT THE BULK OF THE PRECIPITATION LOOKS TO ARRIVE DURING THE OVERNIGHT HOURS. BY TUESDAY...UPPER LEVEL RIDGING WILL RETURN TO THE PLAINS...AND DRY AIR WILL MOVE INTO THE REGION. FIRE WEATHER MIGHT BE A CONCERN ON TUESDAY...DEPENDING ON THE LOCATION AND MAGNITUDE OF ANY PRECIPITATION THAT FALLS MONDAY NIGHT. CURRENTLY...MODELS SOUNDINGS INDICATE GOOD BOUNDARY LAYER MIXING DURING THE DAY ON TUESDAY TO AT LEAST 850 MB...ALSO HELPING DRY THINGS OUT. WITH THIS SOLUTION...DEWPOINTS NEED TO BE LOWERED BY AS MUCH AS 5 TO 10 DEGREES IN SOME LOCATIONS. FOR NOW DECIDED AGAINST LOWERING DEWPOINTS BY THIS MUCH...AS IT REMAINS DAY 4 AND PRECIPITATION CHANCES ON MONDAY WILL GREATLY AFFECT DEWPOINTS ON TUESDAY. HOWEVER...THAT BEING SAID...SHOULD THE GFS SOLUTION VERIFY...RELATIVE HUMIDITY VALUES ACROSS THE WESTERN PORTION OF THE CWA...WILL LIKELY BE WELL BELOW 20 PERCENT. TOWARDS THE END OF THE LONG TERM...BOTH THE GFS AND THE ECMWF SUGGEST A MID LEVEL SHORT WAVE AND WEAK SURFACE LOW PRESSURE SYSTEM WILL PUSH ACROSS CENTRAL PLAINS...CREATING A CHANCE FOR PRECIPITATION THURSDAY NIGHT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE/AVIATION...PFANNKUCH SHORT TERM...ROSSI LONG TERM...SALTZMAN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1038 PM EDT SAT MAR 24 2012 .SYNOPSIS... AN UPPER LEVEL LOW PASSING TO OUR SOUTH...WILL SPREAD SHOWERS ACROSS THE REGION THIS EVENING AND CONTINUE THROUGH THE OVERNIGHT PERIOD. SHOWERS WILL DIMINISH SUNDAY MORNING...BUT MOSTLY CLOUDY SKIES WILL PERSIST. A COLD FRONT WILL PASS SUNDAY NIGHT...YIELDING MUCH COOLER WEATHER FOR EARLY IN THE WORK WEEK...INCLUDING TEMPERATURES WELL BELOW FREEZING AREA WIDE MONDAY NIGHT AND TUESDAY NIGHT. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... .1035 PM UPDATE... AS WAS THE CASE BEFORE...LARGE SCALE DEFORMATION ZONE STILL SPRAWLING OVER THE FORECAST REGION THIS EVENING. IN FACT...FEATURE IS SHOWING UP BEAUTIFULLY IN BOTH IR AND WATER VAPOR SATELLITE IMAGES AS A SHEARING AREA OF CLOUDS OVER UPSTATE NY. IN ANY EVENT...THERE ARE TWO MAIN AREAS OF PRECIP WORTH WATCHING THIS HOUR WITH THE FIRST RESIDING ACROSS THE NORTHERN CWA WHICH APPEARS TO BE THE DIRECT RESULT OF THE PREVIOUSLY MENTIONED LOW/MID-LEVEL DEFORMATION ZONE. THE NEXT AREA OF PRECIP IS BEGINNING TO WORK NORTH FROM EASTERN PA/WESTERN NJ WHICH APPEARS TO BE IN RESPONSE TO A STRENGTHENING LOW-LEVEL JET AHEAD OF THE SOUTHWARD SAGGING CUTOFF LOW WHICH CONTINUES TO DIG SOUTHEAST TOWARDS THE CAROLINAS. THE LOW LEVEL JET WAS NOTED ON BOTH THE KBGM AND KDIX RADAR VAD WIND PROFILES AS 30-40 KTS MAXIMUMS CENTERED BETWEEN 3 AND 4 KFT RESPECTIVELY. DESPITE THE INTIMIDATING APPEARANCE ON RADAR...ANY PRECIP ACROSS THE AREA CONTINUES TO BATTLE LOW-LEVEL DRY AIR WITH THE LATEST AVP OBSERVATION SHOWING A DEWPOINT DEPRESSION OF 30 DEGREES. WITH MODEL GUIDANCE CONTINUING TO SUGGEST WIDESPREAD SHOWERS ACROSS THE AREA OVERNIGHT...CURRENT OBSERVATION AND RADAR TRENDS SUPPORT DROPPING POPS INTO THE CHANCE CATEGORY FOR THE NEXT FEW HRS AS MUCH OF THIS ACTIVITY IS NOT HITTING THE GROUND. EXPECT PROSPECTS FOR RA TO INCREASE ACROSS THE NORTHERN CWA OVERNIGHT AS DEFORMATION AXIS BEGINS TO PIVOT TOWARDS THE SOUTHWEST IN ADVANCE OF EASTWARD ADVANCING SHORTWAVE APPROACHING FROM WESTERN ONTARIO. BASED ON LOW-LEVEL DRY AIR IN PLACE...HAVE ADDED DZ MENTION AREA WIDE THROUGH THE REMAINDER OF THE OVERNIGHT HRS IN ADDITION TO THE RA MENTION. HAVE ALSO HAD TO BUMP OVERNIGHT LOWS UP A FEW DEGREES AS WARM THERMAL ADVECTION COMBINED WITH ABUNDANT CLOUD COVER IS PREVENTING TEMPS FROM FALLING AS QUICKLY AS PREVIOUSLY FORECAST. .7 PM UPDATE... PRECIP HAVING A VERY DIFFICULT TIME MAINTAINING ITSELF THIS EVENING AS LOW/MID-LEVEL DEFORMATION ESSENTIALLY SHEARS OUT ANYTHING TRYING TO DEVELOP. LATEST WATER VAPOR IMAGES SHOW THIS SHEARING ZONE QUITE WELL WITH RUC H70 STREAMLINES DEPICTING A WELL DEFINED COL APPROACHING OUR AREA FROM THE NORTHWEST. IN ADDITION...ANYTHING TRYING TO FALL IS STILL BATTLING LOW-LEVEL DRY AIR WITH 20+ DEGREE DEW POINT DEPRESSIONS NOTED ACROSS PORTIONS OF THE AREA. BASED ON LATEST RADAR TRENDS AND THE FACTS LISTED ABOVE...WE HAVE NO CHOICE BUT TO DECREASE POPS FROM LIKELY TO CHANCE FOR THE NEXT FEW HOURS AND THAT/S EVEN A STRETCH. AS THE EVENING HOURS CONTINUE ON...SHOWER ACTIVITY OVER WESTERN NY/SOUTHERN ONTARIO WILL BEGIN TO MOVE SOUTHEAST AS SHEAR AXIS SINKS SOUTH IN ADVANCE OF APPROACHING COL/SHORTWAVE OVER WESTERN ONTARIO. AS THIS OCCURS THOUGH...ONGOING PRECIP WILL AGAIN MOVE INTO A DRIER AIRMASS WHICH WILL LIKELY CURTAIL ONGOING ACTIVITY TO SOME DEGREE...AND LATEST HRRR SIMULATED REFLECTIVITY TRENDS SUPPORT THIS LINE OF THINKING. ALL IN ALL...HAVE NOT MADE ANY LARGE WHOLESALE CHANGES JUST YET AS WE/D LIKE TO CONTINUE TO MONITOR RADAR/SATELLITE TRENDS BEFORE DOING SO. IN ANY EVENT...THIS FEATURE IS TURING OUT TO BE A DUD FOR HOPEFUL/NEEDED RAINFALL. WILL CONTINUE TO MONITOR. .PREVIOUS NEAR TERM DISCUSSION... AT 4 PM...LOCAL RADARS SHOW WIDESPREAD LIGHT SHOWERS ACROSS NORTHERN/CENTRAL PENNSYLVANIA WITH SCATTERED ACTIVITY OVER CENTRAL NEW YORK. H5 UPPER LEVEL LOW OVER TN WILL CONTINUE TO DROP SOUTHEAST OVERNIGHT AND BE NEAR NORTH CAROLINA/SOUTH CAROLINA BY MORNING. SO FAR THE SHOWERS HAVE HAD A DIFFICULT TIME MOVING NORTH DUE TO LARGE TEMP/DEW POINT DEPRESSIONS. THIS EVENING LOW LEVELS WILL CONTINUE TO SATURATE UNDER MOIST SOUTHEAST FLOW AND INCREASING ISENTROPIC LIFT. EXPECT SHOWERS TO BECOME WIDESPREAD THIS EVENING FROM SOUTH TO NORTH, INCREASED POPS TO LIKELY ALL AREAS. LOW TEMPS OVERNIGHT WILL RANGE FROM THE MID TO UPPER 40S. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... SUNDAY...UPPER LEVEL FEATURE WILL CONTINUE DROPPING SOUTHEAST AND RESIDE OFF THE SOUTH CAROLINA COAST BY AFTERNOON. MODELS INDICATE A WEAK SFC REFLECTION WILL RESIDE OVER CENTRAL NEW YORK DURING THE MORNING HOURS THEN LIFT EAST WITH A DRIER WESTERLY FLOW DEVELOPING DURING THE AFTERNOON. WILL CONTINUE WITH LIKELY POPS FOR THE MORNING HOURS ACROSS THE NRN/FAR EASTERN CWA WHERE BETTER MOISTURE AND SFC CONVERGENCE MAY ENHANCE ACTIVITY. REST OF AREA JUST CHC POPS WITH POPS OVERALL DECREASING RAPIDLY DURING THE AFTERNOON UNDER NORTHWEST FLOW. SKIES WILL REMAIN MOSTLY CLOUDY FOR MUCH OF THE AFTERNOON AS LOW LEVEL MOISTURE LINGERS. MAX TEMPS WILL RANGE FROM THE UPPER 50S TO LOWER 60S. SUNDAY NIGHT/MONDAY...H5 SHORT WAVE TROF WILL MOVE THROUGH EASTERN CANADA DRAGGING A SIGNIFICANT COLD FRONT THROUGH THE REGION LATE SUNDAY NIGHT. BOUNDARY IS MOISTURE STARVED SO NO PRECIP EXPECTED WITH FROPA BUT A SIGNIFICANT CHANGE IN AIRMASS WILL OCCUR AS T85 PLUMMETS TO -10C BY 12Z MONDAY. ON MONDAY, SFC HIGH PRES NEAR JAMES BAY WILL GRADUALLY BUILD SOUTH BRINGING MOSTLY SUNNY SKIES BUT MAXES ONLY IN THE UPPER 30S TO MID 40S. MONDAY AFTERNOON, DUE TO LOW LEVEL INSTABILITY AND STRONG PRES GRADIENT GUSTY WINDS ARE EXPECTED WITH GUSTS AROUND 40 MPH POSSIBLE IN THE HIGHER TERRAIN OF THE WESTERN CATSKILLS. MONDAY NIGHT/TUESDAY...MONDAY NIGHT, HIGH PRES WILL BUILD SOUTH OVER THE REGION RESULTING IN MAINLY CLEAR SKIES AND DIMINISHING WINDS. TEMPS WILL DROP INTO THE MIDDLE TEENS TO THE LOWERS 20S. LAKE RESPONSE NOT EXPECTED DUE TO SHORT FETCH AND EXTREMELY DRY AIRMASS. ON TUESDAY THE SFC HIGH WILL BE OVER CENTRAL NY WITH LIGHT WINDS AND MOSTLY SUNNY SKIES. MAXES WILL RANGE IN THE MID TO UPPER 40S. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... 3 PM SAT UPDATE... ON THE LARGE-SCALE...THE PATN ACROSS NORTH AMERICA THIS PD WILL FEATURE AN ERN PACIFIC TROUGH...FRONT RANGE/CNTRL CONUS RIDGE...AND A CANADIAN MARITIME/WRN ATLANTIC TROUGH AXIS. THIS WILL KEEP NY/PA WITHIN A W TO NW FLOW PATN ALOFT...FEATURING NEAR NORMAL TEMPS FOR LATE MAR (HIGHS MOSTLY IN THE 40S AND 50S)...AND FRNTL PASSAGES/SHOWERY PDS ABT EVERY 2-3 DAYS...WITH GENERALLY DRY CONDS OTHERWISE. SENSIBLE WX-WISE...AN APPROACHING FRNTL COMPLEX WILL BRING OUR FIRST EPISODE OF -SHRA LATE TUE NGT AND WED (MAYBE EVEN A BIT OF -SHSN/--SHSN AT THE START). THIS SYSTEM WILL MOVE OFF TO THE E BY LATE WED NGT/EARLY THU...WITH MAINLY DRY WX ANTICIPATED FOR THE SECOND HALF OF THE WORK WEEK (THU AND FRI). NEXT WEEKEND...ANOTHER UPR-LVL DISTURBANCE/WARM FRNTL BNDRY IN THE LWR LVLS WILL BRING IN THE POTENTIAL FOR -SHRA. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... 7 PM SAT UPDATE... VFR CONDS AREA-WIDE THIS EVE...COULD DETERIORATE A BIT INTO THE MVFR CAT AFTER 06Z...IN --SHRA/LWR CIGS...SPCLY AT KELM/KAVP/KBGM. THAT BEING SAID...ALMOST ALL AVAILABLE CIG/VSBY GUIDANCE IS MUCH LWR DURING THE NGT...INDICATING THE POTENTIAL FOR IFR. HOWEVER...GIVEN THE AMT OF DRY AIR IN THE BLYR THAT STILL HAS TO BE OVERCOME...AND ALSO THE FACT THAT THE BEST FORCING MECHANISMS TO GENERATE LGT RAIN ARE PROGGED TO TRACK MOSTLY S OF OUR FCST AREA LTR TNT AND EARLY SUN...WE FEEL THE GUIDANCE IS TOO PESSIMISTIC. DEFINITELY A LOW CONFIDENCE FCST...THOUGH. KSYR AND KRME SEEM THE MOST PROBABLE SITES TO REMAIN VFR. CONDS SHOULD SLOWLY IMPROVE DURING THE DAY SUN...AS A WEAKENING COLD FRNT PUSHES SEWD THROUGH THE RGN...AND DRIER AIR FILTERS IN FROM THE NW. LGT WINDS IN THE DEEPER VLYS (KELM/KAVP)...AND E TO SE WINDS 5-10 KT ELSEWHERE DURG THE NGT AND EARLY SUN...SHOULD SHIFT INTO THE W AND NW BY MIDDAY. .OUTLOOK... SUN NGT TO TUE NGT...VFR. MAYBE MVFR CIGS AT KSYR KITH KELM MONDAY... DUE TO LAKE EFFECT MOISTURE AND NNW FLOW. WED TO THU...MVFR IN SHOWERS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...RRM NEAR TERM...CMG/RRM SHORT TERM...RRM LONG TERM...MLJ AVIATION...MLJ/TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
750 PM EDT SAT MAR 24 2012 .SYNOPSIS... AN UPPER LEVEL LOW PASSING TO OUR SOUTH...WILL SPREAD SHOWERS ACROSS THE REGION THIS EVENING AND CONTINUE THROUGH THE OVERNIGHT PERIOD. SHOWERS WILL DIMINISH SUNDAY MORNING...BUT MOSTLY CLOUDY SKIES WILL PERSIST. A COLD FRONT WILL PASS SUNDAY NIGHT...YIELDING MUCH COOLER WEATHER FOR EARLY IN THE WORK WEEK...INCLUDING TEMPERATURES WELL BELOW FREEZING AREA WIDE MONDAY NIGHT AND TUESDAY NIGHT. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... .7 PM UPDATE... PRECIP HAVING A VERY DIFFICULT TIME MAINTAINING ITSELF THIS EVENING AS LOW/MID-LEVEL DEFORMATION ESSENTIALLY SHEARS OUT ANYTHING TRYING TO DEVELOP. LATEST WATER VAPOR IMAGES SHOW THIS SHEARING ZONE QUITE WELL WITH RUC H70 STREAMLINES DEPICTING A WELL DEFINED COL APPROACHING OUR AREA FROM THE NORTHWEST. IN ADDITION...ANYTHING TRYING TO FALL IS STILL BATTLING LOW-LEVEL DRY AIR WITH 20+ DEGREE DEW POINT DEPRESSIONS NOTED ACROSS PORTIONS OF THE AREA. BASED ON LATEST RADAR TRENDS AND THE FACTS LISTED ABOVE...WE HAVE NO CHOICE BUT TO DECREASE POPS FROM LIKELY TO CHANCE FOR THE NEXT FEW HOURS AND THAT/S EVEN A STRETCH. AS THE EVENING HOURS CONTINUE ON...SHOWER ACTIVITY OVER WESTERN NY/SOUTHERN ONTARIO WILL BEGIN TO MOVE SOUTHEAST AS SHEAR AXIS SINKS SOUTH IN ADVANCE OF APPROACHING COL/SHORTWAVE OVER WESTERN ONTARIO. AS THIS OCCURS THOUGH...ONGOING PRECIP WILL AGAIN MOVE INTO A DRIER AIRMASS WHICH WILL LIKELY CURTAIL ONGOING ACTIVITY TO SOME DEGREE...AND LATEST HRRR SIMULATED REFLECTIVITY TRENDS SUPPORT THIS LINE OF THINKING. ALL IN ALL...HAVE NOT MADE ANY LARGE WHOLESALE CHANGES JUST YET AS WE/D LIKE TO CONTINUE TO MONITOR RADAR/SATELLITE TRENDS BEFORE DOING SO. IN ANY EVENT...THIS FEATURE IS TURING OUT TO BE A DUD FOR HOPEFUL/NEEDED RAINFALL. WILL CONTINUE TO MONITOR. .PREVIOUS NEAR TERM DISCUSSION... AT 4 PM...LOCAL RADARS SHOW WIDESPREAD LIGHT SHOWERS ACROSS NORTHERN/CENTRAL PENNSYLVANIA WITH SCATTERED ACTIVITY OVER CENTRAL NEW YORK. H5 UPPER LEVEL LOW OVER TN WILL CONTINUE TO DROP SOUTHEAST OVERNIGHT AND BE NEAR NORTH CAROLINA/SOUTH CAROLINA BY MORNING. SO FAR THE SHOWERS HAVE HAD A DIFFICULT TIME MOVING NORTH DUE TO LARGE TEMP/DEW POINT DEPRESSIONS. THIS EVENING LOW LEVELS WILL CONTINUE TO SATURATE UNDER MOIST SOUTHEAST FLOW AND INCREASING ISENTROPIC LIFT. EXPECT SHOWERS TO BECOME WIDESPREAD THIS EVENING FROM SOUTH TO NORTH, INCREASED POPS TO LIKELY ALL AREAS. LOW TEMPS OVERNIGHT WILL RANGE FROM THE MID TO UPPER 40S. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... SUNDAY...UPPER LEVEL FEATURE WILL CONTINUE DROPPING SOUTHEAST AND RESIDE OFF THE SOUTH CAROLINA COAST BY AFTERNOON. MODELS INDICATE A WEAK SFC REFLECTION WILL RESIDE OVER CENTRAL NEW YORK DURING THE MORNING HOURS THEN LIFT EAST WITH A DRIER WESTERLY FLOW DEVELOPING DURING THE AFTERNOON. WILL CONTINUE WITH LIKELY POPS FOR THE MORNING HOURS ACROSS THE NRN/FAR EASTERN CWA WHERE BETTER MOISTURE AND SFC CONVERGENCE MAY ENHANCE ACTIVITY. REST OF AREA JUST CHC POPS WITH POPS OVERALL DECREASING RAPIDLY DURING THE AFTERNOON UNDER NORTHWEST FLOW. SKIES WILL REMAIN MOSTLY CLOUDY FOR MUCH OF THE AFTERNOON AS LOW LEVEL MOISTURE LINGERS. MAX TEMPS WILL RANGE FROM THE UPPER 50S TO LOWER 60S. SUNDAY NIGHT/MONDAY...H5 SHORT WAVE TROF WILL MOVE THROUGH EASTERN CANADA DRAGGING A SIGNIFICANT COLD FRONT THROUGH THE REGION LATE SUNDAY NIGHT. BOUNDARY IS MOISTURE STARVED SO NO PRECIP EXPECTED WITH FROPA BUT A SIGNIFICANT CHANGE IN AIRMASS WILL OCCUR AS T85 PLUMMETS TO -10C BY 12Z MONDAY. ON MONDAY, SFC HIGH PRES NEAR JAMES BAY WILL GRADUALLY BUILD SOUTH BRINGING MOSTLY SUNNY SKIES BUT MAXES ONLY IN THE UPPER 30S TO MID 40S. MONDAY AFTERNOON, DUE TO LOW LEVEL INSTABILITY AND STRONG PRES GRADIENT GUSTY WINDS ARE EXPECTED WITH GUSTS AROUND 40 MPH POSSIBLE IN THE HIGHER TERRAIN OF THE WESTERN CATSKILLS. MONDAY NIGHT/TUESDAY...MONDAY NIGHT, HIGH PRES WILL BUILD SOUTH OVER THE REGION RESULTING IN MAINLY CLEAR SKIES AND DIMINISHING WINDS. TEMPS WILL DROP INTO THE MIDDLE TEENS TO THE LOWERS 20S. LAKE RESPONSE NOT EXPECTED DUE TO SHORT FETCH AND EXTREMELY DRY AIRMASS. ON TUESDAY THE SFC HIGH WILL BE OVER CENTRAL NY WITH LIGHT WINDS AND MOSTLY SUNNY SKIES. MAXES WILL RANGE IN THE MID TO UPPER 40S. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... 3 PM SAT UPDATE... ON THE LARGE-SCALE...THE PATN ACROSS NORTH AMERICA THIS PD WILL FEATURE AN ERN PACIFIC TROUGH...FRONT RANGE/CNTRL CONUS RIDGE...AND A CANADIAN MARITIME/WRN ATLANTIC TROUGH AXIS. THIS WILL KEEP NY/PA WITHIN A W TO NW FLOW PATN ALOFT...FEATURING NEAR NORMAL TEMPS FOR LATE MAR (HIGHS MOSTLY IN THE 40S AND 50S)...AND FRNTL PASSAGES/SHOWERY PDS ABT EVERY 2-3 DAYS...WITH GENERALLY DRY CONDS OTHERWISE. SENSIBLE WX-WISE...AN APPROACHING FRNTL COMPLEX WILL BRING OUR FIRST EPISODE OF -SHRA LATE TUE NGT AND WED (MAYBE EVEN A BIT OF -SHSN/--SHSN AT THE START). THIS SYSTEM WILL MOVE OFF TO THE E BY LATE WED NGT/EARLY THU...WITH MAINLY DRY WX ANTICIPATED FOR THE SECOND HALF OF THE WORK WEEK (THU AND FRI). NEXT WEEKEND...ANOTHER UPR-LVL DISTURBANCE/WARM FRNTL BNDRY IN THE LWR LVLS WILL BRING IN THE POTENTIAL FOR -SHRA. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... 7 PM SAT UPDATE... VFR CONDS AREA-WIDE THIS EVE...COULD DETERIORATE A BIT INTO THE MVFR CAT AFTER 06Z...IN --SHRA/LWR CIGS...SPCLY AT KELM/KAVP/KBGM. THAT BEING SAID...ALMOST ALL AVAILABLE CIG/VSBY GUIDANCE IS MUCH LWR DURING THE NGT...INDICATING THE POTENTIAL FOR IFR. HOWEVER...GIVEN THE AMT OF DRY AIR IN THE BLYR THAT STILL HAS TO BE OVERCOME...AND ALSO THE FACT THAT THE BEST FORCING MECHANISMS TO GENERATE LGT RAIN ARE PROGGED TO TRACK MOSTLY S OF OUR FCST AREA LTR TNT AND EARLY SUN...WE FEEL THE GUIDANCE IS TOO PESSIMISTIC. DEFINITELY A LOW CONFIDENCE FCST...THOUGH. KSYR AND KRME SEEM THE MOST PROBABLE SITES TO REMAIN VFR. CONDS SHOULD SLOWLY IMPROVE DURING THE DAY SUN...AS A WEAKENING COLD FRNT PUSHES SEWD THROUGH THE RGN...AND DRIER AIR FILTERS IN FROM THE NW. LGT WINDS IN THE DEEPER VLYS (KELM/KAVP)...AND E TO SE WINDS 5-10 KT ELSEWHERE DURG THE NGT AND EARLY SUN...SHOULD SHIFT INTO THE W AND NW BY MIDDAY. .OUTLOOK... SUN NGT TO TUE NGT...VFR. MAYBE MVFR CIGS AT KSYR KITH KELM MONDAY... DUE TO LAKE EFFECT MOISTURE AND NNW FLOW. WED TO THU...MVFR IN SHOWERS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...RRM NEAR TERM...CMG/RRM SHORT TERM...RRM LONG TERM...MLJ AVIATION...MLJ/TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
729 PM EDT SAT MAR 24 2012 .SYNOPSIS... AN UPPER LEVEL LOW PASSING TO OUR SOUTH...WILL SPREAD SHOWERS ACROSS THE REGION THIS EVENING AND CONTINUE THROUGH THE OVERNIGHT PERIOD. SHOWERS WILL DIMINISH SUNDAY MORNING...BUT MOSTLY CLOUDY SKIES WILL PERSIST. A COLD FRONT WILL PASS SUNDAY NIGHT...YIELDING MUCH COOLER WEATHER FOR EARLY IN THE WORK WEEK...INCLUDING TEMPERATURES WELL BELOW FREEZING AREA WIDE MONDAY NIGHT AND TUESDAY NIGHT. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... .7 PM UPDATE... PRECIP HAVING A VERY DIFFICULT TIME MAINTAINING ITSELF THIS EVENING AS LOW/MID-LEVEL DEFORMATION ESSENTIALLY SHEARS OUT ANYTHING TRYING TO DEVELOP. LATEST WATER VAPOR IMAGES SHOW THIS SHEARING ZONE QUITE WELL WITH RUC H70 STREAMLINES DEPICTING A WELL DEFINED COL APPROACHING OUR AREA FROM THE NORTHWEST. IN ADDITION...ANYTHING TRYING TO FALL IS STILL BATTLING LOW-LEVEL DRY AIR WITH 20+ DEGREE DEWPOINT DEPRESSIONS NOTED ACROSS PORTIONS OF THE AREA. BASED ON LATEST RADAR TRENDS AND THE FACTS LISTED ABOVE...WE HAVE NO CHOICE BUT TO DECREASE POPS FROM LIKELY TO CHANCE FOR THE NEXT FEW HOURS AND THAT/S EVEN A STRETCH. AS THE EVENING HOURS CONTINUE ON...SHOWER ACTIVITY OVER WESTERN NY/SOUTHERN ONTARIO WILL BEGIN TO MOVE SOUTHEAST AS SHEAR AXIS SINKS SOUTH IN ADVANCE OF APPROACHING COL/SHORTWAVE OVER WESTERN ONTARIO. AS THIS OCCURS THOUGH...ONGOING PRECIP WILL AGAIN MOVE INTO A DRIER AIRMASS WHICH WILL LIKELY CURTAIL ONGOING ACTIVITY TO SOME DEGREE...AND LATEST HRRR SIMULATED REFLECTIVITY TRENDS SUPPORT THIS LINE OF THINKING. ALL IN ALL...HAVE NOT MADE ANY LARGE WHOLESALE CHANGES JUST YET AS WE/D LIKE TO CONTINUE TO MONITOR RADAR/SATELLITE TRENDS BEFORE DOING SO. IN ANY EVENT...THIS FEATURE IS TURING OUT TO BE A DUD FOR HOPEFUL/NEEDED RAINFALL. WILL CONTINUE TO MONITOR. .PREVIOUS NEAR TERM DISCUSSION... AT 4 PM...LOCAL RADARS SHOW WIDESPREAD LIGHT SHOWERS ACROSS NORTHERN/CENTRAL PENNSYLVANIA WITH SCATTERED ACTIVITY OVER CENTRAL NEW YORK. H5 UPPER LEVEL LOW OVER TN WILL CONTINUE TO DROP SOUTHEAST OVERNIGHT AND BE NEAR NORTH CAROLINA/SOUTH CAROLINA BY MORNING. SO FAR THE SHOWERS HAVE HAD A DIFFICULT TIME MOVING NORTH DUE TO LARGE TEMP/DEW POINT DEPRESSIONS. THIS EVENING LOW LEVELS WILL CONTINUE TO SATURATE UNDER MOIST SOUTHEAST FLOW AND INCREASING ISENTROPIC LIFT. EXPECT SHOWERS TO BECOME WIDESPREAD THIS EVENING FROM SOUTH TO NORTH, INCREASED POPS TO LIKELY ALL AREAS. LOW TEMPS OVERNIGHT WILL RANGE FROM THE MID TO UPPER 40S. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... SUNDAY...UPPER LEVEL FEATURE WILL CONTINUE DROPPING SOUTHEAST AND RESIDE OFF THE SOUTH CAROLINA COAST BY AFTERNOON. MODELS INDICATE A WEAK SFC REFLECTION WILL RESIDE OVER CENTRAL NEW YORK DURING THE MORNING HOURS THEN LIFT EAST WITH A DRIER WESTERLY FLOW DEVELOPING DURING THE AFTERNOON. WILL CONTINUE WITH LIKELY POPS FOR THE MORNING HOURS ACROSS THE NRN/FAR EASTERN CWA WHERE BETTER MOISTURE AND SFC CONVERGENCE MAY ENHANCE ACTIVITY. REST OF AREA JUST CHC POPS WITH POPS OVERALL DECREASING RAPIDLY DURING THE AFTERNOON UNDER NORTHWEST FLOW. SKIES WILL REMAIN MOSTLY CLOUDY FOR MUCH OF THE AFTERNOON AS LOW LEVEL MOISTURE LINGERS. MAX TEMPS WILL RANGE FROM THE UPPER 50S TO LOWER 60S. SUNDAY NIGHT/MONDAY...H5 SHORT WAVE TROF WILL MOVE THROUGH EASTERN CANADA DRAGGING A SIGNIFICANT COLD FRONT THROUGH THE REGION LATE SUNDAY NIGHT. BOUNDARY IS MOISTURE STARVED SO NO PRECIP EXPECTED WITH FROPA BUT A SIGNIFICANT CHANGE IN AIRMASS WILL OCCUR AS T85 PLUMMETS TO -10C BY 12Z MONDAY. ON MONDAY, SFC HIGH PRES NEAR JAMES BAY WILL GRADUALLY BUILD SOUTH BRINGING MOSTLY SUNNY SKIES BUT MAXES ONLY IN THE UPPER 30S TO MID 40S. MONDAY AFTERNOON, DUE TO LOW LEVEL INSTABILITY AND STRONG PRES GRADIENT GUSTY WINDS ARE EXPECTED WITH GUSTS AROUND 40 MPH POSSIBLE IN THE HIGHER TERRAIN OF THE WESTERN CATSKILLS. MONDAY NIGHT/TUESDAY...MONDAY NIGHT, HIGH PRES WILL BUILD SOUTH OVER THE REGION RESULTING IN MAINLY CLEAR SKIES AND DIMINISHING WINDS. TEMPS WILL DROP INTO THE MIDDLE TEENS TO THE LOWERS 20S. LAKE RESPONSE NOT EXPECTED DUE TO SHORT FETCH AND EXTREMELY DRY AIRMASS. ON TUESDAY THE SFC HIGH WILL BE OVER CENTRAL NY WITH LIGHT WINDS AND MOSTLY SUNNY SKIES. MAXES WILL RANGE IN THE MID TO UPPER 40S. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... 3 PM SAT UPDATE... ON THE LARGE-SCALE...THE PATN ACROSS NORTH AMERICA THIS PD WILL FEATURE AN ERN PACIFIC TROUGH...FRONT RANGE/CNTRL CONUS RIDGE...AND A CANADIAN MARITIME/WRN ATLANTIC TROUGH AXIS. THIS WILL KEEP NY/PA WITHIN A W TO NW FLOW PATN ALOFT...FEATURING NEAR NORMAL TEMPS FOR LATE MAR (HIGHS MOSTLY IN THE 40S AND 50S)...AND FRNTL PASSAGES/SHOWERY PDS ABT EVERY 2-3 DAYS...WITH GENERALLY DRY CONDS OTHERWISE. SENSIBLE WX-WISE...AN APPROACHING FRNTL COMPLEX WILL BRING OUR FIRST EPISODE OF -SHRA LATE TUE NGT AND WED (MAYBE EVEN A BIT OF -SHSN/--SHSN AT THE START). THIS SYSTEM WILL MOVE OFF TO THE E BY LATE WED NGT/EARLY THU...WITH MAINLY DRY WX ANTICIPATED FOR THE SECOND HALF OF THE WORK WEEK (THU AND FRI). NEXT WEEKEND...ANOTHER UPR-LVL DISTURBANCE/WARM FRNTL BNDRY IN THE LWR LVLS WILL BRING IN THE POTENTIAL FOR -SHRA. && .AVIATION /23Z SATURDAY THROUGH THURSDAY/... 130 PM UPDATE... VFR CONDITIONS ARE EXPECTED TODAY INTO THIS EVENING THEN FALLING TO MVFR. MVFR LAST TO AT LEAST MIDDAY SUNDAY. ISOLATED TO SCATTERED FOR THE MOST PART NOW, BUT TWO BANDS OF STEADIER SHOWERS NOW TO KAVP AND MOVING NE INTO THE REST OF THE SITES THIS AFTN. WITH THE STEADY SHOWERS LATE AFTN AND EVENING CIGS AND VSBYS WILL FALL TO MVFR FROM SW TO NE BETWEEN 3 AND 6Z. CONDITIONS WORSEN FURTHER LATE TONIGHT. MODEL GUIDANCE HAS IFR VSBYS AND CIGS LATE TONIGHT BUT HAVE HEDGED HIGHER. MODEL GUIDANCE IS TYPICALLY ON THE LOW SIDE. CONFIDENCE LOW. UNDER STEADIEST SHOWERS THEN JUST AHEAD OF SLOW MOVING OCCLUDED FRONT SO THIS MAY HAVE TO BE ADJUSTED DOWN. SLOW RECOVERY LATE MORNING AS SHOWERS MOVE OUT TO THE NE AND FRONT GOES THROUGH. CIGS WILL RISE BUT THINK IT WILL REMAIN MVFR. VSBYS SHOULD RISE TO VFR EXCEPT AT ITH BECAUSE OF THE LAKE. EAST TO SE WINDS AT 5 TO 10 KTS THIS AFTN. TONIGHT WINDS DROP TO 5 KTS. LATE SUNDAY MORNING WINDS SHIFT TO WEST TO NW AT 5 TO 8 KTS. .OUTLOOK... SUN AFTN...MVFR CONDITIONS CONTINUING. SUN NGT TO TUE NGT...VFR. MAYBE MVFR CIGS AT SYR ITH ELM MONDAY DUE TO LAKE EFFECT MOISTURE AND NNW FLOW. WED TO THU...MVFR IN SHOWERS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...RRM NEAR TERM...CMG/RRM SHORT TERM...RRM LONG TERM...MLJ AVIATION...TAC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1045 PM EDT SAT MAR 24 2012 .SYNOPSIS... A STRONG UPPER LEVEL LOW WILL MOVE ACROSS THE SOUTHERN APPALACHIANS TONIGHT AND OFF THE CAROLINA COAST SUNDAY NIGHT. A RIDGE OF HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION ON TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH SUNDAY NIGHT/... AS OF 1045 PM SATURDAY... RECENT SFC ANALYSIS SHOWS A LOW PRESSURE SYSTEM CENTERED OVER THE FOOTHILLS NEAR HICKORY. CONVECTION EARLIER THIS EVENING HAS LARGELY WEAKENED AND SHIFTED NORTHEAST INTO VA. STABLE OUTFLOW FROM THE LARGE LINEAR CONVECTIVE COMPLEX HAS OVERSPREAD NEARLY ALL OF THE PIEDMONT AND INTO THE NORTHERN COASTAL PLAIN. LATEST MESOANALYSIS AND RUC PROXIMITY SOUNDINGS INDICATE THE BOUNDARY LAYER HAS STABILIZED BUT ELEVATED INSTABILITY WITH MUCAPE VALUES OF ~500 J/KG REMAIN. WITH 0-6KM BULK SHEAR VALUES OF 30-40KTS...ELEVATED ORGANIZED CONVECTION IS POSSIBLE OVERNIGHT. EXPECT THE CONVECTIVE COVERAGE TO BE SOMEWHAT LIMITED BUT WILL MAINTAIN SLIGHT CHANCE AND CHANCE POPS FOR THE OVERNIGHT. WITH THIS IN MIND...WILL CLEAR THE TORNADO WATCH FOR ALL LOCATIONS WHILE ACKNOWLEDGING THAT A STRONGER STORM WHILE NOT ROOTED IN THE BOUNDARY LAYER COULD STILL PRODUCE SOME HAIL...WITH THE WIND THREAT AND ESPECIALLY THE TORNADO THREAT MINIMAL. THE SURFACE LOW IS EXPECTED TO SHIFT SLOWLY EAST OVERNIGHT AND BE CENTERED NEAR KFAY BY DAYBREAK SUNDAY. HAVE ADJUSTED WIND FORECAST OVERNIGHT ACCORDINGLY. LOWS OVERNIGHT WILL RANGE FROM THE LOWER 50S IN THE WEST/NW PIEDMONT TO THE UPPER 50S IN THE COASTAL PLAIN. -BLAES FOR SUNDAY AND SUNDAY NIGHT...IF THERE IS A LULL IN SHOWER ACTIVITY SUNDAY MORNING...INSTABILITY SHOWERS AND THUNDERSTORMS ARE EXPECTED TO RE-DEVELOP SUNDAY AFTERNOON UNDERNEATH THE -20 TO 21C H5 COLD CORE...ESPECIALLY IN THE WARM SECTOR EAST OF THE SFC COLD FRONT WHERE STRONGER HEATING WITHIN THE LINGERING LOW-LEVEL MOISTURE TONGUE SHOULD SUPPORT MARGINAL INSTABILITY BETWEEN 500 TO 1000 J/KG OF MUCAPE. HOWEVER...VERY WEAK FLOW BENEATH THE UPPER-LEVEL LOW WILL FAVOR PULSE AS THE MAIN CONVECTIVE MODE WITH THE WIND DAMAGE AND HAIL THREATS LIKELY REMAINING MARGINAL. WILL CONTINUE TO MENTION THE THREAT OF SMALL TO MARGINALLY SEVERE HAIL FOR SUNDAY IN THE HWO. HIGHS SUNDAY AFTERNOON RANGING FROM LOWER 70S NW TO MID/UPPER 70S IN THE EAST. LOWS SUNDAY NIGHT WILL DEPEND ON THE TIMING OF THE SYSTEM EXITING...WITH DRIER AIR/CLEARING FILTERING INTO THE WESTERN PIEDMONT AOA DAYBREAK. LOWS RANGING FROM LOWER TO MID 50S NORTHWEST TO MID/UPPER 50S SOUTHEAST. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 PM SATURDAY... ON MONDAY THE UPPER LEVEL LOW WILL EXIT OFF THE ATLANTIC COAST AND AN H500 RIDGE WILL MOVE EAST TO TAKE ITS PLACE. AT THE SURFACE THE PARENT HIGH WILL MOVE INTO WESTERN ONTARIO. LOW LEVEL FLOW WILL BE OUT OF THE NORTH ON MONDAY AND CONDITIONS MAY BECOME GUSTY BY AFTERNOON IN A WELL MIXED LAYER...15-20 KNOTS. THE ONSET OF COLD AIR ADVECTION WILL BE GENERALLY WEAK DURING THE AFTERNOON BUT WILL INCREASE OVERNIGHT. THIS WILL LEAVE ONE MORE DAY OF HIGH TEMPERATURES CLOSE TO 80 DEGREES. WITH DEWPOINTS RUNNING IN THE 40S...DRY AND PLEASANT CONDITIONS WILL PREVAIL THROUGHOUT THE DAY. HIGHS NEAR 80 WITH LOWS TUESDAY MORNING IN THE MID 40S. STRONGER COLD AIR ADVECTION WILL BEGIN OVERNIGHT MONDAY AND EARLY TUESDAY MORNING AS THE UPPER LEVEL FLOW TURNS NORTHWESTERLY. THE DAY WILL ONCE AGAIN BE DRY AS HIGH PRESSURE MOVES OVER THE REGION WITH LIGHT EASTERLY WINDS AT THE SURFACE. HIGHS WILL BE ON THE ORDER OF 15 DEGREES COOLER THAN MONDAY AS THICKNESSES DROP 40-50 METERS. HIGHS IN THE MID 60S...LOWS IN THE UPPER 40S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 300 PM SATURDAY... ON WEDNESDAY THE SURFACE HIGH MOVES OFF THE CAROLINA COAST. A SURFACE LOW WILL TRACK OVER THE GREAT LAKES WITH ITS ASSOCIATED SHORTWAVE TROUGH. EXPECT SOUTHWESTERLY FLOW ON WEDNESDAY AS CENTRAL NC WILL BE STUCK BETWEEN THE DEPARTING HIGH AND THE APPROACHING LOW. ANY PRECIPITATION WITH THE FRONT SHOULD STAY WELL NORTH OF THE AREA ON WEDNESDAY...KEEPING CONDITIONS WARM AND DRY. HIGH TEMPERATURES WILL RECOVER ABOUT 10 DEGREES FROM TUESDAY AND MOISTURE ADVECTION WILL BEGIN FROM THE SOUTH AS DEWPOINTS WILL RISE INTO THE 50S BY THE END OF THE DAY. HIGHS MID TO UPPER 70S WITH LOWS THURSDAY MORNING IN THE LOWER 50S. THURSDAY IS THE MOST UNCERTAIN DAY IN THE LONG TERM WITH REGARDS TO WHETHER OR NOT THE FRONT DROPPING DOWN FROM THE NORTH WILL FOR ONE MAKE IT COMPLETELY THROUGH THE CWA...AND TWO IF IT WILL BRING PRECIPITATION OR NOT. AT CURRENT TIME THE ECMWF BRINGS IT THROUGH AS A DRY FRONT BY 12Z THURSDAY...WHILE THE GFS IS A LITTLE BIT MORE ROBUST BRINGING SOME SHOWERS THROUGH AT LEAST THE NORTHERN PORTION OF THE CWA AND THEN DRIES OUT WHILE LINGERING ACROSS THE SOUTH THROUGH 18Z OR SO. FOR THIS FORECAST PACKAGE...WILL INTRODUCE SLIGHT CHANCE OF POPS IN THE NORTH AND KEEP THE SOUTHERN PORTION OF THE CWA DRY...SOUTH OF HIGHWAY 64. WITH THE FRONT LINGERING...TEMPERATURES WILL STILL MAKE IT UP INTO THE UPPER 70S TO LOWER 80S WITH A LITTLE BIT COOLER ACROSS THE NORTH. WINDS WILL BE LIGHT AND GRADUALLY VEER TO NORTHWESTERLY AS THE FRONT MOVES SOUTH. LOWS THURSDAY NIGHT UPPER 40S TO LOW 50S. FRIDAY AND SATURDAY WILL BE GENERALLY DRY BEHIND THE FRONT ALTHOUGH THERE IS SOME UNCERTAINTY ON SATURDAY AS A WEAK FRONTAL SYSTEM APPROACHES FROM THE WEST. THE ECMWF KEEPS THE AREA DRY...HOLDING OFF PRECIPITATION UNTIL SUNDAY WHEREAS THE GFS BRINGS IN SCATTERED SHOWERS BY SATURDAY AFTERNOON. SINCE THIS SYSTEM APPEARS WEAK AT THIS TIME...TIMING OF THE ONSET OF PRECIPITATION MAY BE LARGELY DETERMINED BY HOW FAR OFF OF THE COAST THE SURFACE HIGH SETTLES ON SATURDAY. WITH LIGHT UPPER LEVEL FLOW...WILL GO WITH THE ECMWF AT THIS TIME WHICH KEEPS THE HIGH CLOSER TO SHORE AND THUS DRY CONDITIONS FOR SATURDAY. HIGHS DURING THIS PERIOD WILL BE IN THE UPPER 60S TO LOW 70S WITH LOWS IN THE UPPER 40S TO LOWER 50S. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... AS OF 800 PM SATURDAY... MULTIPLE AREAS OF CONVECTION WILL MOVE ACROSS CENTRAL NC FROM WEST TO EAST THIS EVENING INTO THE EARLY OVERNIGHT HOURS. THE CONVECTION WILL RESULT IN BRIEF PERIODS OF LIFR/IFR CIGS AND VSBYS ALONG WITH GUSTS TO 40KTS OR MORE AND SMALL HAIL. THREAT OF CONVECTION WILL DIMINISH ACROSS KINT/KGSO BY 01Z. MAIN THREAT OF CONVECTION AT KRDU WILL END BY 02-03Z AND AT KFAY/KRWI BY 04Z. A COLD FRONT WILL SLOWLY SHIFT ACROSS CENTRAL NC FROM 06-15Z. SCT SHOWERS ARE EXPECTED TO PERSIST OVERNIGHT WITH PERIODS OF MVFR CIGS. AHEAD OF THE FRONT THERE IS THE POTENTIAL FOR SOME FOG TOWARD DAYBREAK ...MAINLY ACROSS KFAY AND KRWI. LIGHT SOUTHEAST TO SOUTHERLY SFC WINDS TONIGHT WILL VEER AROUND TO WEST AND NORTHWEST ON SUNDAY MORNING. VFR/MVFR CONDITIONS ARE EXPECTED ON SUNDAY WITH SCT SHOWERS THAT MAY REDUCE CIGS AND VSBYS BRIEFLY. LOOKING FURTHER AHEAD...FAIR WEATHER WITH VFR CONDITIONS WILL RETURN SUNDAY NIGHT WITH WEST TO EAST CLEARING. VFR CONDITIONS WILL DOMINATE THROUGH THE MIDDLE OF NEXT WEEK AS A RIDGE BUILDS OVER THE AREA FROM THE WEST IN THE WAKE OF THE UPPER LEVEL LOW. -BLAES/CBL && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BLAES NEAR TERM...BLAES/CBL SHORT TERM...RTE LONG TERM...RTE AVIATION...BLAES/CBL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
323 PM CDT FRI MAR 23 2012 .SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT... NO SIGNIFICANT DIFFERENCE IN MODEL SOLUTIONS IN THE SHORT TERM PERIODS AND USED A BLEND OF THE MODELS FOR THE GRIDS. BIGGEST CONCERN IN EARLY FORECAST PERIODS IS POSSIBLY OF FOG REDEVELOPING RAPDILY TONIGHT SHORTLY AFTER SUNDOWN. HRRR AND LAMP DATA INDICATES A VERY SHARP LINE OF STRATUS AND FOG DEVELOPING ACROSS SOUTH CENTRAL AND EAST CENTRAL NORTH DAKOTA BUT DREW THE LINE SOMEWHAT FARTHER WEST AND INCLUDED BISMARCK...MANDAN AND MINOT IN THE FOG. NO ADVISORY AT THIS TIME AS A COLD FRONT WILL PUSH THROUGH THE AREA FROM WEST TO EAST BY MORNING PROMOTING MIXING. SURFACE LOW WILL MOVE EAST OF AREA ON SATURDAY WITH NORTHWEST WINDS DEVELOPING ACROSS THE REGION. RELATIVE HUMIDITIES SHOULD NOT DECREASE TO POINT OF CAUSING FIRE WEATHER ISSUES. SATURDAY HIGH PRESSURE MOVES EAST ACROSS SOUTH CENTRAL CANADA WITH COOL NORTHERLY FLOW OVER THE AREA. .LONG TERM...SUNDAY THROUGH FRIDAY... THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE STORM SYSTEM FORECAST TO IMPACT THE NORTHERN PLAINS LATE MONDAY INTO TUESDAY...AND A BREAK FROM FIRE WEATHER HEADLINES WITH SLIGHTLY COOLER TEMPERATURES...ALBEIT STILL ABOVE NORMAL READINGS. IN REGARDS TO THE DETAILS...A RELATIVELY COOL SUNDAY IS FORECAST ACROSS WESTERN AND CENTRAL NORTH DAKOTA WITH EASTERLY SURFACE FLOW RESULTING STRONG SURFACE HIGH PRESSURE NEAR HUDSON BAY AND LEE SIDE LOW PRESSURE. HIGHS ON SUNDAY SHOULD RANGE FROM THE MID TO UPPER 40S ACROSS THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY...WITH HIGHS NEAR 60 ACROSS THE SOUTHWEST. DESPITE EASTERLY WINDS OF 20 TO 30 MPH...CRITICAL FIRE WEATHER CONDITIONS ARE NOT ANTICIPATED AS A RESULT OF COOLER TEMPERATURES YIELDING AFTERNOON MINIMUM RH VALUES IN THE 30 TO 40 PERCENT RANGE. LEE SIDE CYCLOGENESIS INCREASES LATE MONDAY AFTERNOON AND INTO THE NIGHT AS THE STRONG UPPER LEVEL WAVE FORECAST TO COME ON SHORE INTO CALIFORNIA SUNDAY NIGHT PROPAGATES NORTHEAST TOWARDS THE NORTHERN PLAINS. SOUTH-EASTERLY LOW LEVEL FLOW IS ALSO FORECAST TO INCREASE DURING THIS TIMEFRAME AS A RESULT OF THE CYCLOGENESIS WITH GULF MOISTURE TRANSPORT INTO THE NORTHERN PLAINS AS PWATS CLIMB INTO THE 0.75 TO 1.0 INCH RANGE BY MONDAY NIGHT. GIVEN THE LOW LEVEL WARM AIR ADVECTION REGIME ASSOCIATED WITH THE SOUTHERLY FLOW...CAPPING SHOULD PREVENT CONVECTIVE INITIATION THROUGH THE AFTERNOON...WITH A MORE FAVORED AREA FOR DEVELOPMENT DURING THE AFTERNOON AND EARLY EVENING CLOSER TO THE SURFACE WARM FRONT ACROSS SOUTH DAKOTA. HOWEVER...CONVECTIVE CHANCES DO INCREASE MONDAY NIGHT AS THE MAIN UPPER LEVEL WAVE APPROACHES WITH A STRENGTHENING LOW LEVEL JET AND STEEP MID LEVEL LAPSE RATES. OVERALL ELEVATED CAPE IS LESS AND FURTHER SOUTH TODAY COMPARED TO YESTERDAY. HOWEVER...ISOLATED MARGINAL SEVERE HAIL WITH ELEVATED STORMS MONDAY NIGHT IS POSSIBLE GIVEN THE AMPLE SHEAR PROFILES AND MID LEVEL LAPSE RATES. THE UPPER LEVEL LOW IS FORECAST TO CLOSE OFF ACROSS NORTHEAST SOUTH DAKOTA TUESDAY MORNING WITH WRAP AROUND PRECIPITATION ASSOCIATED WITH THE TROWAL/DEFORMATION ZONE CONTINUING ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA DURING THE DAY ON TUESDAY. AT THIS TIME ALL PRECIPITATION APPEARS TO BE RAIN...WITH A SLIGHT CHANCE FOR SOME FLAKES TO MIX IN LATE TUESDAY EVENING AS COLDER AIR IS DRAWN INTO THE SYSTEM. TUESDAY ALSO LOOKS TO BE WINDY...ESPECIALLY ACROSS THE SOUTHWEST AND SOUTH CENTRAL GIVEN STRONG ISALLOBARIC FORCING ON THE BACKSIDE OF THE LOW COUPLED WITH COLD AIR ADVECTION AND GOOD LOW LEVEL MIXING. GIVEN THE STRENGTH OF THE WIND FIELD TUESDAY AFTERNOON INTO THE EVENING...THE UPCOMING MODEL CYCLES WILL HAVE TO BE MONITORED CLOSELY IF ANY SNOW WILL BE ABLE TO COUPLE WITH THE WINDS TO CREATE POSSIBLE TRAVEL PROBLEMS. HOWEVER...THE 23/12 UTC DETERMINISTIC SUITE IS SLIGHTLY COOLER COMPARED TO YESTERDAY...YET WOULD STILL FAVOR ALL RAIN. IN THE WAKE OF THE TUESDAY SYSTEM...THE UPPER LEVEL CENTRAL CONUS RIDGE IS FORECAST TO RE-AMPLIFY WITH ABOVE NORMAL TEMPERATURES FAVORED FOR THE REMAINDER OF THE EXTENDED. && .AVIATION... THE LOW LEVEL STRATUS FIELD THAT WAS IN PLACE ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING HAS ERODED AND LIFTED AS A STRATOCUMULUS FIELD THIS AFTERNOON. HOWEVER...HIGH RESOLUTION MODEL GUIDANCE IS SUGGESTING THE STRATUS FIELD TO FILL IN AND THE FOG TO RETURN AFTER SUNSET THIS EVENING. THIS SEEMS PLAUSIBLE WITH LITTLE AIRMASS CHANGE ACROSS MUCH OF THE AREA TONIGHT UNTIL COLD FRONT PUSHES THROUGH THE AREA BETWEEN 10-15 UTC SATURDAY MORNING. THEREFORE...HAVE INCLUDED STRATUS REFORMATION AND POSSIBLE FOG DEVELOPMENT INTO THE KMOT...KBIS AND KJMS TAF SITES....WHILE THE WESTERN TAF SITES OF KDIK AND KISN MAY REMAIN WEST OF THE STRATUS FIELD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HW LONG TERM....PJA AVIATION...PJA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
132 PM EDT FRI MAR 23 2012 .SYNOPSIS... A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL PUSH INTO THE REGION BY SATURDAY. THIS LOW WILL THEN SLIDE OFF TO THE SOUTHEAST SUNDAY WITH HIGH PRESSURE BUILDING BACK IN EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPPER LEVEL LOW IS EVIDENT ON WATER VAPOR IMAGERY SPINNING ACROSS SOUTHEAST MISSOURI THIS MORNING. AS THE LOW PUSHES SLOWLY EAST THROUGH THE DAY...BANDS OF SHOWERS ROTATING UP THROUGH THE MID OHIO VALLEY WILL ALSO SLOWLY WORK THEIR WAY EAST ACROSS MUCH OF OUR AREA. THE EASTWARD PROGRESSION HAS BEEN RATHER SLOW THOUGH AND THE LATEST RUC SEEMS TO BE PICKING UP ON THIS. WILL THEREFORE KEEP HIGHEST POPS MAINLY ACROSS OUR WEST THROUGH A GOOD PART OF THE DAY. LIGHTNING HAS BEEN FAIRLY SPOTTY SO FAR AND THINK CLOUDS WILL HELP KEEP INSTABILITY SOMEWHAT MARGINAL...SO EXPECT MAINLY SHOWERS WITH JUST A CHANCE OF THUNDER. CLOUDS AND PCPN SHOULD HELP KEEP TEMPS FROM GETTING TOO OUT OF HAND WITH TEMPERATURES GENERALLY IN THE UPPER 60S TO NEAR 70. OUR FAR NORTHEAST SHOULD SEE A LITTLE MORE SUN THIS MORNING AND THIS MAY ALLOW THEM TO GET A BIT WARMER. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... UPR LVL CLOSED LOW WILL CONTINUE TO SLOWLY INCH ITS WAY EAST OVERNIGHT. COLD FRONT AHEAD OF THIS FEATURE WILL OCCLUDE AND WILL MOVE ENE THROUGH THE AREA. BEST CHANCES FOR PCPN WILL BE ACRS THE ERN ZONES EARLY ON. SOME OF THE MESOSCALE MODELS INDICATE THAT LIKELY POPS MAY OCCUR ACRS THE SWRN SECTIONS THIS EVENING/OVERNIGHT AS OCCLUDED FRONT PUSHES THROUGH. HAVE DECIDED TO LEAVE HIGH CHANCE IN THIS AREA ATTM GIVEN LOW CONFIDENCE. HAVE USED A BLEND OF RAW MODEL DATA TO COME UP WITH OVERNIGHT LOWS...WHICH SHOULD RANGE FROM THE LOWER 50S SW TO THE UPPER 50S NE. FOR SATURDAY INTO SATURDAY NIGHT...UPR LVL CLOSED LOW IS FORECAST TO PIVOT ESE THROUGH THE OHIO VALLEY. ATTM...A WEAK SFC TROF AND SFC LOW WILL TREK ACRS THE REGION. LOW LEVEL FORCING WILL BE WEAK AT BEST...BUT MODELS INDICATE THAT A ROTATING VORT LOBE MAY PROVIDE THE BEST UPR LVL SUPPORT ACRS THE SWRN ZONES. THUS...HAVE GONE WITH CHANCE POPS EXCEPT ACRS THE SWRN ZONES WHERE LIKELY POPS WILL BE USED. BEST CHANCE OF THUNDER WILL OCCUR DURING THE HEAT OF THE DAY WHEN LOW LEVEL LAPSE RATES WILL BE THE GREATEST. PCPN SHOULD DECREASE SATURDAY EVENING AS UPR LVL PULLS AWAY AND INSTABILITY DROPS OFF. TEMPERATURES...ALTHOUGH COOLER...WILL STILL BE ABOVE NORMAL DESPITE THE UPR LVL CLOSED LOW. HIGHS WILL RANGE FROM THE MID TO UPPER 60S. LOWS WILL DROP INTO THE UPPER 40S TO THE LOWER 50S. FOR SUNDAY INTO SUNDAY NIGHT...ECMWF AND GFS DEPICT A DIGGING MID LVL TROF WHICH WILL PUSH INTO SE CANADA/NRN NEW ENGLAND BY MONDAY MORNING. THIS SYSTEM WILL PUSH A COLD FRONT SOUTH THROUGH THE REGION SUNDAY/SUNDAY EVENING. WILL HOLD ON TO LOW CHANCES POPS WITH FRONTAL PASSAGE. DRIER AIR AND CLEARING SKIES LATE SUNDAY NIGHT WILL MARK THE BEGINNING OF A COOLING TREND. FOR MONDAY INTO MONDAY NIGHT...CANADIAN HIGH PRESSURE WILL BUILD SOUTHWARD INTO THE GREAT LAKES AND OHIO VALLEY. CAA WILL BRING TEMPERATURES DOWN CLOSER TO NORMALS FOR LATE MARCH. WITH CLEAR SKIES MONDAY NIGHT...SOME GUIDANCE SUGGESTS THAT LOWS MAY DROP BELOW FREEZING...ESPECIALLY ACRS NRN AND ERN SECTIONS. THIS COULD POSE A PROBLEM GIVEN THAT VEGETATION IS WELL AHEAD OF SCHEDULE DUE TO THE VERY UNSEASONABLY WARM WEATHER THAT WE HAVE EXPERIENCED. && .LONG TERM /TUESDAY THROUGH THURSDAY/... HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE REGION THROUGH TUESDAY. THE NEXT SYSTEM WILL BEGIN TO BRING SHOWERS AND THUNDERSTORMS INTO WESTERN PORTIONS OF THE FA LATE TUESDAY NIGHT WITH A BETTER CHANCE OF THUNDERSTORM ACTIVITY ON WEDNESDAY. A COLD FRONT WILL MOVE THROUGH WEDNESDAY NIGHT AND PRECIPITATION WILL END ACROSS THE FA BY THURSDAY MORNING. TEMPERATURES WILL WARM ONCE AGAIN BY WEDNESDAY WITH 70S EXPECTED. TEMPERATURES WILL COOL BEHIND THE FRONT ON THURSDAY. && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... UPPER LEVEL LOW OVER SOUTHERN MISSOURI WILL PUSH SLOWLY EAST ACROSS THE LOWER OHIO VALLEY THROUGH SATURDAY. AHEAD OF THIS...BANDS OF SHOWERS AND PERHAPS A FEW THUNDERSTORMS WILL ROTATE UP ACROSS OUR REGION. THE INITIAL BAND IS CONTINUING TO AFFECT MAINLY THE WESTERN PORTIONS OF OUR AREA AND WILL CONTINUE TO DO SO THROUGH THE AFTERNOON. AS IT PROGRESSES SLOWLY EAST...IT SHOULD EVENTUALLY REACH CENTRAL OHIO TOWARD LATE AFTERNOON. INSTABILITY REMAINS MARGINAL WITHIN THIS BAND SO THINK THUNDER WILL REMAIN FAIRLY ISOLATED. BETTER INSTABILITY BACK TO OUR SOUTHWEST IS LEADING TO MORE WIDESPREAD THUNDERSTORM ACTIVITY ACROSS SOUTHERN ILLINOIS AND WESTERN KENTUCKY. THIS WAVE SHOULD EVENTUALLY PUSH EAST INTO OUR AREA LATER TONIGHT BUT BY THAT TIME...INSTABILITY SHOULD ONCE AGAIN BE MARGINAL AND WILL THEREFORE HOLD OFF ON MENTIONING THUNDER LATER TONIGHT. JUST AHEAD OF THE LOW...THERE WERE SOME LOW CLOUDS AND FOG THIS MORNING AND SOME OF THIS MAY REDEVELOP ACROSS OUR AREA LATE TONIGHT. ANY FOG/LOWER CLOUDS SHOULD DISSIPATE THROUGH LATE MORNING. EXPECT WIDESPREAD CU TO DEVELOP FROM LATE MORNING INTO EARLY AFTERNOON AS UPPER LEVEL LOW APPROACHES. WILL ALSO LIKELY SEE SOME SCATTERED SHOWER/THUNDERSTORM DEVELOPMENT TOWARD THE END OF THE TAF PERIOD. OUTLOOK...MVFR CEILINGS POSSIBLE AT TIMES THROUGH SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HICKMAN NEAR TERM...JGL SHORT TERM...HICKMAN LONG TERM...HICKMAN/NOVAK AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
955 AM EDT FRI MAR 23 2012 .SYNOPSIS... A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL PUSH INTO THE REGION BY SATURDAY. THIS LOW WILL THEN SLIDE OFF TO THE SOUTHEAST SUNDAY WITH HIGH PRESSURE BUILDING BACK IN EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPPER LEVEL LOW IS EVIDENT ON WATER VAPOR IMAGERY SPINNING ACROSS SOUTHEAST MISSOURI THIS MORNING. AS THE LOW PUSHES SLOWLY EAST THROUGH THE DAY...BANDS OF SHOWERS ROTATING UP THROUGH THE MID OHIO VALLEY WILL ALSO SLOWLY WORK THEIR WAY EAST ACROSS MUCH OF OUR AREA. THE EASTWARD PROGRESSION HAS BEEN RATHER SLOW THOUGH AND THE LATEST RUC SEEMS TO BE PICKING UP ON THIS. WILL THEREFORE KEEP HIGHEST POPS MAINLY ACROSS OUR WEST THROUGH A GOOD PART OF THE DAY. LIGHTNING HAS BEEN FAIRLY SPOTTY SO FAR AND THINK CLOUDS WILL HELP KEEP INSTABILITY SOMEWHAT MARGINAL...SO EXPECT MAINLY SHOWERS WITH JUST A CHANCE OF THUNDER. CLOUDS AND PCPN SHOULD HELP KEEP TEMPS FROM GETTING TOO OUT OF HAND WITH TEMPERATURES GENERALLY IN THE UPPER 60S TO NEAR 70. OUR FAR NORTHEAST SHOULD SEE A LITTLE MORE SUN THIS MORNING AND THIS MAY ALLOW THEM TO GET A BIT WARMER. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... UPR LVL CLOSED LOW WILL CONTINUE TO SLOWLY INCH ITS WAY EAST OVERNIGHT. COLD FRONT AHEAD OF THIS FEATURE WILL OCCLUDE AND WILL MOVE ENE THROUGH THE AREA. BEST CHANCES FOR PCPN WILL BE ACRS THE ERN ZONES EARLY ON. SOME OF THE MESOSCALE MODELS INDICATE THAT LIKELY POPS MAY OCCUR ACRS THE SWRN SECTIONS THIS EVENING/OVERNIGHT AS OCCLUDED FRONT PUSHES THROUGH. HAVE DECIDED TO LEAVE HIGH CHANCE IN THIS AREA ATTM GIVEN LOW CONFIDENCE. HAVE USED A BLEND OF RAW MODEL DATA TO COME UP WITH OVERNIGHT LOWS...WHICH SHOULD RANGE FROM THE LOWER 50S SW TO THE UPPER 50S NE. FOR SATURDAY INTO SATURDAY NIGHT...UPR LVL CLOSED LOW IS FORECAST TO PIVOT ESE THROUGH THE OHIO VALLEY. ATTM...A WEAK SFC TROF AND SFC LOW WILL TREK ACRS THE REGION. LOW LEVEL FORCING WILL BE WEAK AT BEST...BUT MODELS INDICATE THAT A ROTATING VORT LOBE MAY PROVIDE THE BEST UPR LVL SUPPORT ACRS THE SWRN ZONES. THUS...HAVE GONE WITH CHANCE POPS EXCEPT ACRS THE SWRN ZONES WHERE LIKELY POPS WILL BE USED. BEST CHANCE OF THUNDER WILL OCCUR DURING THE HEAT OF THE DAY WHEN LOW LEVEL LAPSE RATES WILL BE THE GREATEST. PCPN SHOULD DECREASE SATURDAY EVENING AS UPR LVL PULLS AWAY AND INSTABILITY DROPS OFF. TEMPERATURES...ALTHOUGH COOLER...WILL STILL BE ABOVE NORMAL DESPITE THE UPR LVL CLOSED LOW. HIGHS WILL RANGE FROM THE MID TO UPPER 60S. LOWS WILL DROP INTO THE UPPER 40S TO THE LOWER 50S. FOR SUNDAY INTO SUNDAY NIGHT...ECMWF AND GFS DEPICT A DIGGING MID LVL TROF WHICH WILL PUSH INTO SE CANADA/NRN NEW ENGLAND BY MONDAY MORNING. THIS SYSTEM WILL PUSH A COLD FRONT SOUTH THROUGH THE REGION SUNDAY/SUNDAY EVENING. WILL HOLD ON TO LOW CHANCES POPS WITH FRONTAL PASSAGE. DRIER AIR AND CLEARING SKIES LATE SUNDAY NIGHT WILL MARK THE BEGINNING OF A COOLING TREND. FOR MONDAY INTO MONDAY NIGHT...CANADIAN HIGH PRESSURE WILL BUILD SOUTHWARD INTO THE GREAT LAKES AND OHIO VALLEY. CAA WILL BRING TEMPERATURES DOWN CLOSER TO NORMALS FOR LATE MARCH. WITH CLEAR SKIES MONDAY NIGHT...SOME GUIDANCE SUGGESTS THAT LOWS MAY DROP BELOW FREEZING...ESPECIALLY ACRS NRN AND ERN SECTIONS. THIS COULD POSE A PROBLEM GIVEN THAT VEGETATION IS WELL AHEAD OF SCHEDULE DUE TO THE VERY UNSEASONABLY WARM WEATHER THAT WE HAVE EXPERIENCED. && .LONG TERM /TUESDAY THROUGH THURSDAY/... HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE REGION THROUGH TUESDAY. THE NEXT SYSTEM WILL BEGIN TO BRING SHOWERS AND THUNDERSTORMS INTO WESTERN PORTIONS OF THE FA LATE TUESDAY NIGHT WITH A BETTER CHANCE OF THUNDERSTORM ACTIVITY ON WEDNESDAY. A COLD FRONT WILL MOVE THROUGH WEDNESDAY NIGHT AND PRECIPITATION WILL END ACROSS THE FA BY THURSDAY MORNING. TEMPERATURES WILL WARM ONCE AGAIN BY WEDNESDAY WITH 70S EXPECTED. TEMPERATURES WILL COOL BEHIND THE FRONT ON THURSDAY. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... THE OVERALL WEATHER CONDITIONS TODAY WILL FEATURE OCCASIONAL RAIN SHOWERS...AND POSSIBLY SOME THUNDERSTORMS (ESPECIALLY IN THE AFTERNOON). THE WEATHER SYSTEM CAUSING THIS ACTIVITY IS MOVING ONLY VERY SLOWLY EASTWARD...WITH ALL OF THE INDIVIDUAL BANDS OF PRECIPITATION MOVING ALMOST DUE NORTH. THIS MAKES IT MORE DIFFICULT THAN NORMAL TO PROVIDE EXACT TIMING IN THE FORECAST FOR EACH INDIVIDUAL BATCH OF SHOWERS MORE THAN A FEW HOURS IN ADVANCE. MVFR (AND POSSIBLY IFR) CONDITIONS WILL BE POSSIBLE IN THE HEAVIER SHOWERS...WHICH WOULD OF COURSE BE ESPECIALLY TRUE IN THUNDERSTORMS. CHANCES OF HEAVIER PRECIPITATION WILL END BY EVENING. AS AN UPPER LEVEL LOW PRESSURE SYSTEM MOVES INTO THE REGION...DISORGANIZED SHOWERS WILL CONTINUE TO BE POSSIBLE THROUGH SATURDAY AND BEYOND. THE MOISTURE WITH THIS SYSTEM IS NOT ESPECIALLY DEEP SO OCCASIONAL MVFR CONDITIONS SEEM TO BE THE WORST OF WHAT IS EXPECTED AT THIS TIME. OUTLOOK...MVFR CEILINGS POSSIBLE EARLY ON SATURDAY AND AT TIMES THROUGH SUNDAY. THUNDERSTORMS POSSIBLE ON SATURDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HICKMAN NEAR TERM...JGL SHORT TERM...HICKMAN LONG TERM...HICKMAN/NOVAK AVIATION...HATZOS
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1047 PM CDT SAT MAR 24 2012 .DISCUSSION.../ISSUED AT 900 PM CDT/ BACKDOOR COLD FRONT HAS JUST PUSHED THROUGH SIOUX FALLS AND CONTINUES TO MOVE SOUTH. MAIN UPDATE WAS JUST TO ADJUST TIMING OF THIS FRONT MOVING ACROSS THE CWA TONIGHT. WINDS WILL PICK UP FROM THE NORTH NORTHEAST BEHIND IT...GUSTING 20 TO 30 MPH. ADJUSTED LOW TEMPERATURES DOWN A FEW DEGREES TONIGHT...GIVEN THE QUICK DROP BEHIND THE FRONT AND THE CONTINUED LOW LEVEL CAA EXPECTED THROUGH THE NIGHT. WENT WITH VALUES CLOSER TO THE RUC AND HRRR...AS THEY APPEAR TO BE HANDLING THE FRONTAL PASSAGE FAIRLY WELL. NEXT CHALLENGE TONIGHT IS POSSIBLE STRATUS DEVELOPMENT. SEEING SOME STRATUS ON SATELLITE ALREADY MAKING IT DOWN INTO BROOKINGS AND LINCOLN COUNTIES. THIS IS SHOWN WELL ON NAM 925MB RH AND HRRR CLOUD COVER PRODUCTS. EXPECT THIS TO CONTINUE TO SLOWLY MOVE SOUTH...THOUGH IT SHOULD ALSO BEGIN TO DISSIPATE...BEFORE POTENTIALLY REFORMING CLOSER TO THE MISSOURI RIVER...WHERE LOW LEVEL DEWPOINTS WILL REMAIN HIGHER. HOWEVER...LATER TONIGHT...WINDS TURN SOUTHWESTERLY AROUND 800MB...WITH INCREASING MOISTURE IN THAT LAYER. THUS WILL LIKELY SEE STRATUS BEGIN TO DEVELOP THERE AS WELL. SO IN GENERALLY...EXPECT A GRADUAL INCREASE IN STRATUS TONIGHT ACROSS THE CWA...WITH MUCH OF THE AREA POTENTIALLY BEING MOSTLY CLOUDY BY MORNING. /CHENARD .PREVIOUS DISCUSSION.../ISSUED AT 345 PM CDT TONIGHTS FORECAST CHALLENGE INCLUDE STRATUS POTENTIAL AND LOW TEMPERATURES. FRONTAL PASSAGE FINALLY COMES DOWN IN EARNEST THIS EVENING...WHICH WILL INCREASE THE NORTHERLY SURFACE FLOW AFTER EVENING AND OVERNIGHT. ONE THING TO NOTE IS THE STRATUS IN EASTERN ND IS EDGING SOUTHWARD. THIS POST FRONTAL STRATUS IS MORE ORGANIZED THEN THE STRATUS IN CENTRAL SD...WHICH IS MIXING OUT AT THIS TIME. THEREFORE HEDGED SOME STRATUS COMING DOWN FIRST IN OUR NORTHEAST ZONES...THEN SOUTHWARD TOWARD I 90 AS THE OVERNIGHT PROGRESSES. THE SURFACE WINDS BECOME EASTERLY TONIGHT...AND MY INITIAL WORRY WAS STRATUS BACKING IN FROM MINNESOTA. HOWEVER THAT STRATUS IS ALSO MIXING OUT SO IT MAY NOT BE A PROBLEM. WITH THE STRATUS COOLED TEMPERATURES TO THE NORTH OF OUR FORECAST AREA...AND WITH THE WINDS BECOMING NE AND E...COOLED OFF LOWS A LITTLE BIT TONIGHT IN OUR NORTHERN AND WESTERN ZONES. STRATUS MAY ALSO DEVELOP IN OUR S CENTRAL SD ZONES LATE TONIGHT AS THE AIR MASS REACHES SATURATION IN THAT AREA. ON SUNDAY...THE LOW LEVEL BOUNDARY WITH THE BACK DOOR COLD FRONT IS EXTREMELY STRONG IN THIS AREA. THEREFORE BACKED OFF ON TEMPERATURES ACROSS OUR NORTHERN FORECAST AREA AS THEY MAY ALSO BE HINDERED BY A CLOUD DECK IN THE 4500 TO 6500 FOOT RANGE MUCH OF THE DAY. BUT SOUTH OF THE BOUNDARY...SIOUX CITY MAY HIT THE UPPER 70S WHICH GIVES ALMOST A 20 DEGREE TEMPERATURE DIFFERENCE FROM NORTH TO SOUTH IN OUR AREA. /MJF MAY GENERATE SOME CONVECTION IN OUR NORTH EARLY ON SUNDAY NIGHT AS THE 925 MB FRONT BEGINS TO LIFT NORTHWARD...A MID LEVEL WAVE TRACKS INTO THE WEST...AND THE LOW LEVEL JET BEGINS TO STRENGTHEN. THEN MAY SEE ADDITIONAL DEVELOPMENT ALONG THE MISSOURI RIVER LATER IN THE NIGHT ALONG THE BETTER ELEVATED INSTABILITY AXIS/THETA E ADVECTION/AND LOWER LEVEL CONVERGENCE ON THE NOSE OF THE STRENGTHENING LOW LEVEL JET. COULD HAVE A COUPLE OF SEVERE STORMS WITH ELEVATED CAPE VALUES BETWEEN 1000 TO 1500 J/KG AND EFFECTIVE SHEAR OF 35 TO 40 KTS. THIS FORCING WILL LIFT NORTH AND EAST THROUGH THE EARLY PART OF MONDAY...SO FOLLOWED SUIT WITH POPS TAKING THEM ACROSS OUR NORTH AND EAST INTO EARLY AFTERNOON. CANNOT COMPLETELY RULE OUT ISOLATED CONVECTION BACK TO THE WEST ON MONDAY MORNING WITH THE MOISTURE TRANSPORT AND INSTABILITY...THOUGH HARD TO PIN POINT...AND THE ATMOSPHERE WILL BECOME INCREASINGLY STABLE THROUGH THE MORNING HOURS AND BECOME MORE CAPPED FROM THE SOUTHWEST DURING THE EARLY PART OF THE DAY. DID KEEP A CHANCE OF POPS IN OUR NORTHEAST THROUGH THE LATER AFTERNOON WITH THE 925 MB FRONT REMAINING OVER THAT AREA. TIGHT THERMAL GRADIENT WILL LINGER OVER THE AREA ON MONDAY AFTERNOON...WITH HIGHS AROUND 60 IN MARSHALL TO THE LOWER 80S THROUGH THE MISSOURI RIVER CORRIDOR. WILL ALSO BE A WINDY DAY WITH A TIGHTENING GRADIENT AND HIGHER WINDS ALOFT. THE MAIN UPPER LEVEL SHORTWAVE WILL TRACK ACROSS THE REGION ON MONDAY NIGHT AS THE SURFACE COLD FRONT EXTENDING FROM THE PARENT LOW OVER NORTH DAKOTA BEGINS TO PUSH THROUGH THE AREA. WITH THIS...EXPECT SCATTERED CONVECTION TO PUSH FROM WEST TO EAST ACROSS THE CWA DURING THE NIGHT...AND CANNOT RULE OUT A COUPLE OF SEVERE STORMS IN OUR WEST DURING THE EVENING. WILL BE A VERY MILD NIGHT WITH THE WINDS AND A SOUTHERLY COMPONENT FLOW...WITH TEMPERATURES ONLY DROPPING INTO THE LOWER 50S NORTH TO UPPER 50S FAR SOUTH. TUESDAY WILL SEE THE SYSTEM RETREATING FROM THE AREA...AND MODELS NOW INDICATING A DRY DAY WITH ANY WRAP AROUND PRECIPITATION REMAINING TO OUR NORTH. IT WILL BE A VERY WINDY DAY HOWEVER WITH THE TIGHT GRADIENT AND WINDS AT THE TOP OF THE MIXED LAYER RUNNING BETWEEN 35 TO 40 KTS. WITH THE WINDS AND AFTERNOON TEMPERATURES IN THE LOWER 70S ACROSS OUR SOUTH...IN ADDITION TO RH VALUES IN THE LOWER TO MID 20S OVER THAT AREA...WILL MOST LIKELY HAVE SOME FIRE WEATHER ISSUES FOR THAT DAY. IN THE EXTENDED...WEDNESDAY THROUGH SATURDAY...MODELS IN DECENT ON AGREEMENT ON UPPER LEVEL RIDGING BUILDING INTO THE REGION ON WEDNESDAY AND EARLY THURSDAY...BEFORE A SHORTWAVE OVER THE PACIFIC NORTHWEST TOPS THE RIDGE LATER ON THURSDAY INTO FRIDAY BRINGING OUR NEXT CHANCE OF PRECIPITATION DURING THAT TIME FRAME. LOOKS TO BE A GENERAL WARMING TREND THROUGH THE PERIOD...WITH 925 MB TEMPERATURES GOING FROM THE SINGLE DIGITS AND LOW TEENS C ON WEDNESDAY...TO MID TEENS TO POSSIBLY MID 20S C BY SATURDAY. /JM && .AVIATION.../FOR THE 06Z TAF ISSUANCE/ BAND OF MVFR TO IFR CEILINGS NEAR OVC010 WILL SPREAD SOUTH ALONG THE INTERSTATE 29 CORRIDOR THROUGH 12Z SUNDAY AND THEN GRADUALLY BECOME VFR DURING THE MORNING. OTHERWISE WILL BE VFR THROUGH MOST OF THE CWA AFTER 15Z SUNDAY THROUGH 06Z MONDAY. THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORM NORTH OF A HON-MML LINE SUNDAY EVENING WITH A BETTER CHANCE SOUTH OF I90 AND WEST OF I29 LATE SUNDAY NIGHT. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
900 PM CDT SAT MAR 24 2012 .DISCUSSION.../ISSUED AT 900 PM CDT/ BACKDOOR COLD FRONT HAS JUST PUSHED THROUGH SIOUX FALLS AND CONTINUES TO MOVE SOUTH. MAIN UPDATE WAS JUST TO ADJUST TIMING OF THIS FRONT MOVING ACROSS THE CWA TONIGHT. WINDS WILL PICK UP FROM THE NORTH NORTHEAST BEHIND IT...GUSTING 20 TO 30 MPH. ADJUSTED LOW TEMPERATURES DOWN A FEW DEGREES TONIGHT...GIVEN THE QUICK DROP BEHIND THE FRONT AND THE CONTINUED LOW LEVEL CAA EXPECTED THROUGH THE NIGHT. WENT WITH VALUES CLOSER TO THE RUC AND HRRR...AS THEY APPEAR TO BE HANDLING THE FRONTAL PASSAGE FAIRLY WELL. NEXT CHALLENGE TONIGHT IS POSSIBLE STRATUS DEVELOPMENT. SEEING SOME STRATUS ON SATELLITE ALREADY MAKING IT DOWN INTO BROOKINGS AND LINCOLN COUNTIES. THIS IS SHOWN WELL ON NAM 925MB RH AND HRRR CLOUD COVER PRODUCTS. EXPECT THIS TO CONTINUE TO SLOWLY MOVE SOUTH...THOUGH IT SHOULD ALSO BEGIN TO DISSIPATE...BEFORE POTENTIALLY REFORMING CLOSER TO THE MISSOURI RIVER...WHERE LOW LEVEL DEWPOINTS WILL REMAIN HIGHER. HOWEVER...LATER TONIGHT...WINDS TURN SOUTHWESTERLY AROUND 800MB...WITH INCREASING MOISTURE IN THAT LAYER. THUS WILL LIKELY SEE STRATUS BEGIN TO DEVELOP THERE AS WELL. SO IN GENERALLY...EXPECT A GRADUAL INCREASE IN STRATUS TONIGHT ACROSS THE CWA...WITH MUCH OF THE AREA POTENTIALLY BEING MOSTLY CLOUDY BY MORNING. /CHENARD .PREVIOUS DISCUSSION.../ISSUED AT 345 PM CDT TONIGHTS FORECAST CHALLENGE INCLUDE STRATUS POTENTIAL AND LOW TEMPERATURES. FRONTAL PASSAGE FINALLY COMES DOWN IN EARNEST THIS EVENING...WHICH WILL INCREASE THE NORTHERLY SURFACE FLOW AFTER EVENING AND OVERNIGHT. ONE THING TO NOTE IS THE STRATUS IN EASTERN ND IS EDGING SOUTHWARD. THIS POST FRONTAL STRATUS IS MORE ORGANIZED THEN THE STRATUS IN CENTRAL SD...WHICH IS MIXING OUT AT THIS TIME. THEREFORE HEDGED SOME STRATUS COMING DOWN FIRST IN OUR NORTHEAST ZONES...THEN SOUTHWARD TOWARD I 90 AS THE OVERNIGHT PROGRESSES. THE SURFACE WINDS BECOME EASTERLY TONIGHT...AND MY INITIAL WORRY WAS STRATUS BACKING IN FROM MINNESOTA. HOWEVER THAT STRATUS IS ALSO MIXING OUT SO IT MAY NOT BE A PROBLEM. WITH THE STRATUS COOLED TEMPERATURES TO THE NORTH OF OUR FORECAST AREA...AND WITH THE WINDS BECOMING NE AND E...COOLED OFF LOWS A LITTLE BIT TONIGHT IN OUR NORTHERN AND WESTERN ZONES. STRATUS MAY ALSO DEVELOP IN OUR S CENTRAL SD ZONES LATE TONIGHT AS THE AIR MASS REACHES SATURATION IN THAT AREA. ON SUNDAY...THE LOW LEVEL BOUNDARY WITH THE BACK DOOR COLD FRONT IS EXTREMELY STRONG IN THIS AREA. THEREFORE BACKED OFF ON TEMPERATURES ACROSS OUR NORTHERN FORECAST AREA AS THEY MAY ALSO BE HINDERED BY A CLOUD DECK IN THE 4500 TO 6500 FOOT RANGE MUCH OF THE DAY. BUT SOUTH OF THE BOUNDARY...SIOUX CITY MAY HIT THE UPPER 70S WHICH GIVES ALMOST A 20 DEGREE TEMPERATURE DIFFERENCE FROM NORTH TO SOUTH IN OUR AREA. /MJF MAY GENERATE SOME CONVECTION IN OUR NORTH EARLY ON SUNDAY NIGHT AS THE 925 MB FRONT BEGINS TO LIFT NORTHWARD...A MID LEVEL WAVE TRACKS INTO THE WEST...AND THE LOW LEVEL JET BEGINS TO STRENGTHEN. THEN MAY SEE ADDITIONAL DEVELOPMENT ALONG THE MISSOURI RIVER LATER IN THE NIGHT ALONG THE BETTER ELEVATED INSTABILITY AXIS/THETA E ADVECTION/AND LOWER LEVEL CONVERGENCE ON THE NOSE OF THE STRENGTHENING LOW LEVEL JET. COULD HAVE A COUPLE OF SEVERE STORMS WITH ELEVATED CAPE VALUES BETWEEN 1000 TO 1500 J/KG AND EFFECTIVE SHEAR OF 35 TO 40 KTS. THIS FORCING WILL LIFT NORTH AND EAST THROUGH THE EARLY PART OF MONDAY...SO FOLLOWED SUIT WITH POPS TAKING THEM ACROSS OUR NORTH AND EAST INTO EARLY AFTERNOON. CANNOT COMPLETELY RULE OUT ISOLATED CONVECTION BACK TO THE WEST ON MONDAY MORNING WITH THE MOISTURE TRANSPORT AND INSTABILITY...THOUGH HARD TO PIN POINT...AND THE ATMOSPHERE WILL BECOME INCREASINGLY STABLE THROUGH THE MORNING HOURS AND BECOME MORE CAPPED FROM THE SOUTHWEST DURING THE EARLY PART OF THE DAY. DID KEEP A CHANCE OF POPS IN OUR NORTHEAST THROUGH THE LATER AFTERNOON WITH THE 925 MB FRONT REMAINING OVER THAT AREA. TIGHT THERMAL GRADIENT WILL LINGER OVER THE AREA ON MONDAY AFTERNOON...WITH HIGHS AROUND 60 IN MARSHALL TO THE LOWER 80S THROUGH THE MISSOURI RIVER CORRIDOR. WILL ALSO BE A WINDY DAY WITH A TIGHTENING GRADIENT AND HIGHER WINDS ALOFT. THE MAIN UPPER LEVEL SHORTWAVE WILL TRACK ACROSS THE REGION ON MONDAY NIGHT AS THE SURFACE COLD FRONT EXTENDING FROM THE PARENT LOW OVER NORTH DAKOTA BEGINS TO PUSH THROUGH THE AREA. WITH THIS...EXPECT SCATTERED CONVECTION TO PUSH FROM WEST TO EAST ACROSS THE CWA DURING THE NIGHT...AND CANNOT RULE OUT A COUPLE OF SEVERE STORMS IN OUR WEST DURING THE EVENING. WILL BE A VERY MILD NIGHT WITH THE WINDS AND A SOUTHERLY COMPONENT FLOW...WITH TEMPERATURES ONLY DROPPING INTO THE LOWER 50S NORTH TO UPPER 50S FAR SOUTH. TUESDAY WILL SEE THE SYSTEM RETREATING FROM THE AREA...AND MODELS NOW INDICATING A DRY DAY WITH ANY WRAP AROUND PRECIPITATION REMAINING TO OUR NORTH. IT WILL BE A VERY WINDY DAY HOWEVER WITH THE TIGHT GRADIENT AND WINDS AT THE TOP OF THE MIXED LAYER RUNNING BETWEEN 35 TO 40 KTS. WITH THE WINDS AND AFTERNOON TEMPERATURES IN THE LOWER 70S ACROSS OUR SOUTH...IN ADDITION TO RH VALUES IN THE LOWER TO MID 20S OVER THAT AREA...WILL MOST LIKELY HAVE SOME FIRE WEATHER ISSUES FOR THAT DAY. IN THE EXTENDED...WEDNESDAY THROUGH SATURDAY...MODELS IN DECENT ON AGREEMENT ON UPPER LEVEL RIDGING BUILDING INTO THE REGION ON WEDNESDAY AND EARLY THURSDAY...BEFORE A SHORTWAVE OVER THE PACIFIC NORTHWEST TOPS THE RIDGE LATER ON THURSDAY INTO FRIDAY BRINGING OUR NEXT CHANCE OF PRECIPITATION DURING THAT TIME FRAME. LOOKS TO BE A GENERAL WARMING TREND THROUGH THE PERIOD...WITH 925 MB TEMPERATURES GOING FROM THE SINGLE DIGITS AND LOW TEENS C ON WEDNESDAY...TO MID TEENS TO POSSIBLY MID 20S C BY SATURDAY. /JM && .AVIATION.../FOR THE 00Z TAF ISSUANCE/ MAIN SURGE OF GUSTY NORTH WINDS JUST NORTH OF I90 AT 23Z WITH LOW LEVEL FLOW BECOMING MORE NORTH TO NORTHEAST DURING THE NIGHT AND THEN TO THE EAST ON SUNDAY. SHOULD REMAIN VFR THROUGH 04Z AND THEN EXPECT MVFR CEILINGS TO DROP SOUTHEAST INTO SOUTHWEST MINNESOTA AND PORTIONS OF NORTHWEST IOWA AND PERSIST INTO SUNDAY MORNING BEFORE BECOMING VFR AGAIN. REST OF CWA SHOULD REMAIN VFR THROUGH 00Z MONDAY. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1254 PM CDT FRI MAR 23 2012 .DISCUSSION... DENSE FOG VERY SLOWLY DECREASING THIS MORNING. WILL LET THE ADVISORY EXPIRE AT 1000 AM...BUT STILL PLAN ON SOME DENSE FOG IN MAINLY NW IA AND SW MN FOR AN HOUR OR TWO LONGER. OTHERWISE...ANOTHER UNSEASONABLY WARM DAY AHEAD WITH VERY LITTLE WIND...SO VERY PLEASANT. HIGHS FROM THE UPPER 60S TO LOWER 70S STILL LOOKS ON TARGET. /08 && .AVIATION.../FOR THE 18Z TAF ISSUANCE/ OTHER THAN A SMALL PATCH OF IFR CEILINGS EAST OF THE BUFFALO RIDGE VFR CONDITIONS ARE EXPECTED THROUGH ABOUT 6Z THIS EVENING. MAINLY MVFR TYPE FOG IS ANTICIPATED TONIGHT HOWEVER NEAR AND EAST OF THE BUFFALO RIDGE THERE WILL BE A BETTER CHANCE FOR THE DEVELOPMENT OF IFR OR LIFR VISIBILITIES IN FOG WITH LIGHT WINDS AND RESIDUAL LOW LEVEL MOISTURE. OTHERWISE...FROM ABOUT 15Z SATURDAY ON VFR CONDITIONS WILL AGAIN PREVAIL. /08 && .PREV DISCUSSION.../ISSUED AT 416 AM CDT/ INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW... EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE AND IOWA GREAT LAKES. OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND. THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL SD...PAN OUT FOR MONDAY AFTERNOON. BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT. QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY... THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT. UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD SHOULD BE COOLER THAN THE NEXT FEW DAYS. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
945 AM CDT FRI MAR 23 2012 .DISCUSSION... DENSE FOG VERY SLOWLY DECREASING THIS MORNING. WILL LET THE ADVISORY EXPIRE AT 1000 AM...BUT STILL PLAN ON SOME DENSE FOG IN MAINLY NW IA AND SW MN FOR AN HOUR OR TWO LONGER. OTHERWISE...ANOTHER UNSEASONABLY WARM DAY AHEAD WITH VERY LITTLE WIND...SO VERY PLEASANT. HIGHS FROM THE UPPER 60S TO LOWER 70S STILL LOOKS ON TARGET. /08 && .PREV DISCUSSION.../ISSUED AT 416 AM CDT/ INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW... EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE AND IOWA GREAT LAKES. OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND. THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL SD...PAN OUT FOR MONDAY AFTERNOON. BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT. QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY... THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT. UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD SHOULD BE COOLER THAN THE NEXT FEW DAYS. && .AVIATION.../FOR THE 12Z TAF ISSUANCE/ DENSE VLIFR FOG WILL CONTINUE AT KFSD UNTIL AT LEAST 15Z...THEN SHOULD GRADUALLY LIFT BETWEEN 15Z-17Z. KHON AND KSUX HAVE REMAINED JUST WEST OF THE DENSE FOG...AND SOME IFR VISIBILITIES AND CEILINGS MAY BE BRIEFLY POSSIBLE AT THESE LOCATIONS BEFORE 15Z. BY 18Z...ALL TAF SITES SHOULD IMPROVE TO VFR...HOWEVER SOME LIGHT FOG MAY BE POSSIBLE AGAIN AFTER MIDNIGHT SATURDAY AT KFSD AND KSUX. /LAFLIN && .FSD WATCHES/WARNINGS/ADVISORIES... IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR IAZ001>003- 012>014-020>022. MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072- 080-081-089-090-097-098. NE...NONE. SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ038>040- 054>056-061-062-067. && $$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
642 AM CDT FRI MAR 23 2012 .DISCUSSION.../ISSUED AT 416 AM CDT/ INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW... EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE AND IOWA GREAT LAKES. OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND. THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL SD...PAN OUT FOR MONDAY AFTERNOON. BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT. QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY... THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT. UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD SHOULD BE COOLER THAN THE NEXT FEW DAYS. && .AVIATION.../FOR THE 12Z TAF ISSUANCE/ DENSE VLIFR FOG WILL CONTINUE AT KFSD UNTIL AT LEAST 15Z...THEN SHOULD GRADUALLY LIFT BETWEEN 15Z-17Z. KHON AND KSUX HAVE REMAINED JUST WEST OF THE DENSE FOG...AND SOME IFR VISIBILITIES AND CEILINGS MAY BE BRIEFLY POSSIBLE AT THESE LOCATIONS BEFORE 15Z. BY 18Z...ALL TAF SITES SHOULD IMPROVE TO VFR...HOWEVER SOME LIGHT FOG MAY BE POSSIBLE AGAIN AFTER MIDNIGHT SATURDAY AT KFSD AND KSUX. /LAFLIN && .FSD WATCHES/WARNINGS/ADVISORIES... IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR IAZ001>003- 012>014-020>022. MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072- 080-081-089-090-097-098. NE...NONE. SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ038>040- 054>056-061-062-067. && $$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
416 AM CDT FRI MAR 23 2012 .DISCUSSION.../ISSUED AT 416 AM CDT/ INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW... EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE AND IOWA GREAT LAKES. OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND. THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL SD...PAN OUT FOR MONDAY AFTERNOON. BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT. QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY... THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT. UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD SHOULD BE COOLER THAN THE NEXT FEW DAYS. && .AVIATION.../FOR THE 06Z TAF ISSUANCE/ FOG HAS BEGUN TO DEVELOP ACROSS NORTHWEST IOWA AND IS EXPECTED TO BECOME MORE WIDESPREAD OVER THE NEXT FEW HOURS. FOG APPEARS TO BE DEVELOPING A FEW HOURS FASTER THAN THE HRRR OUTPUT. APPEARS AS THOUGH CLOUD COVER WILL KEEP FOG POTENTIAL AT BAY FOR A FEW HOURS AT KHON...BUT FOG IS EXPECTED TO IMPACT KFSD TERMINAL FIRST...THEN EXPANDING TO KHON AND EVENTUALLY DOWN THE RIVER VALLEY IN NORTHWEST IOWA. HAVE LOWERED EXPECTED VISIBILITIES IN THE TAFS...BUT HAVE NOT MENTIONED QUARTER MILE YET EVEN THOUGH IT IS POSSIBLE. OVERNIGHT CREW WILL HAVE TO WATCH THIS CLOSELY. WITH VERY WEAK WINDS ACROSS THE AREA...FOG WILL LIKELY STICK AROUND THROUGH THE 15-17 TIME FRAME...WHEN IT WILL GRADUALLY MIX OUT. THEREAFTER...LIGHT WINDS AND MOSTLY CLEAR SKIES ARE EXPECTED. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR IAZ001>003- 012>014-020>022. MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072- 080-081-089-090-097-098. NE...NONE. SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ038>040- 054>056-061-062-067. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1148 PM CDT THU MAR 22 2012 .UPDATE...FOR 06Z AVIATION DISCUSSION. && .AVIATION...06Z AVIATION DISCUSSION. UNCERTAINTIES...ACTUAL UPPER LEVEL LOW MOVEMENT/INFLUENCES AND SHWR/TSTM DEVELOPMENT LENGTH AND COVERAGE. SEVERAL ADMS POSSIBLE THRU 24/06Z. SOME GENERAL UNCERTAINTY WITH ACTUAL CLOUD COVERAGE TRENDS...WITH POTENTIAL DRY SLOT DEVELOPMENT LEADING TO MVFR FOG DEVELOPMENT 23/06Z-23/12Z. SHWRS/TSTMS SHOULD REDEVELOP PER PROXIMITY OF UPPER LEVEL LOW AND DIURNAL HEATING INFLUENCES BY 23/17Z... WITH VFR CU CEILINGS PREDOMINATE. PER QUESTIONS OF ACTUAL UPPER LEVEL LOW PROXIMITY...WILL MENTION ONLY VCTS IN TAFS AFTER 24/00Z. && .PREV DISCUSSION.../ISSUED 1022 PM CDT THU MAR 22 2012/ UPDATE... CONVECTION ACROSS THE PLATEAU HAS NEARLY MOVED OUT OF THE AREA LEAVING THE MID STATE VIRTUALLY PRECIP FREE RIGHT NOW. HOWEVER...LATEST RUC AND NAM SOLUTIONS CONTINUE TO SHOW THAT SOME LATE NIGHT UPPER LEVEL ENERGY COULD GET CONVECTION GOING ONCE AGAIN. WILL GO AHEAD AND DROP POPS DOWN TO THE CHC CATEGORY ACROSS OUR EAST. PREV DISCUSSION... /ISSUED 651 PM CDT THU MAR 22 2012/ UPDATE...FOR 00Z AVIATION DISCUSSION. AVIATION...00Z AVIATION DISCUSSION. UNCERTAINTIES...ACTUAL UPPER LEVEL LOW MOVEMENT/INFLUENCES AND SHWR/TSTM DEVELOPMENT. SEVERAL ADMS POSSIBLE THRU 23/24Z. SOME GENERAL UNCERTAINTY WITH ACTUAL CLOUD COVERAGE TRENDS...ALONG WITH MVFR FOG DEVELOPMENT 23/06Z-23/12Z CKV/BNA. THUS...DIMINISH LIGHT SHWRS AND ERODE CEILINGS BY 23/03Z CKV/BNA...WITH REDEVELOPING SHWRS/TSTMS PER DIURNAL INFLUENCES AND APPROACHING UPPER LEVEL LOW BY 23/24Z...WITH VFR CEILINGS. PER BETTER OVERALL MOISTURE...CSV MVFR CEILINGS WITH LIGHT SHWRS TRANISTIONING TO TSTMS FROM 23/14Z-23/24Z. PREV DISCUSSION.../ISSUED 632 PM CDT THU MAR 22 2012/ UPDATE... SFC BOUNDARY ACROSS WESTERN MIDDLE TN CONTINUES TO DECREASE IN STRENGTH IN TERMS OF THE FORCING ASSOCIATED WITH IT. ACTIVITY ACROSS OUR EASTERN ZONES IS IN RESPONSE TO AN UPPER IMPULSE WITHIN THE SOUTHERLY FLOW ALOFT. REDEVELOPMENT ACROSS WESTERN ZONES IS STILL EXPECTED AS ADDITIONAL UPPER LEVEL ENERGY IS EXPECTED TO LIFT NORTHWARD OVERNIGHT. LATEST NAM12 AND RUC SOLUTIONS ARE IN FAVOR OF REDEVELOPMENT. HOWEVER...ADDITIONAL QPF AMOUNTS ARE NOT SIGNIFICANT AND LOOK TO BE ONLY AROUND ONE QUARTER INCH OR SO. FOR TONIGHT...I WILL BE LEANING TOWARD LOWERING THE POPS AS THE FUTURE CONVECTION IS DEPENDENT UPON REDEVELOPMENT AS OPPOSED TO MIGRATION. OTW...LOW TEMPS LOOK TO BE IN GOOD SHAPE. THE LOWER DEW POINTS ARE WAY BACK TOWARD FAR WESTERN TN. STILL THOUGH...FOR LOW TEMPS WE SHOULD SEE UPPER 50S WESTERN AREAS BY SUNRISE WITH NEAR 60 ELSEWHERE. A GENERALLY LIGHT S/SE WIND FLOW SHOULD CONTINUE. UPDATED GIRDS/ZONES OUT SHORTLY. PREV DISCUSSION... /ISSUED 339 PM CDT THU MAR 22 2012/ SHORT TERM...BAND OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES TO MOVE SLOWLY EASTWARD ACROSS THE MID STATE THIS AFTERNOON. BY MID-AFTERNOON, THE BAND WAS CENTERED NEAR THE I-65 CORRIDOR. AFTERNOON TEMPERATURES WERE MAINLY IN THE 70S WHERE RAIN HAD NOT YET ARRIVED, BUT WERE IN THE UPPER 50S TO UPPER 60S IN THE RAIN-COOLED AIR. MODEL SOLUTIONS ARE STILL QUITE SIMILAR WITH THEIR HANDLING OF SLOW-MOVING CLOSED UPPER LOW OVER THE NEXT FEW DAYS. THE MAIN FORECAST DIFFICULTY WILL BE THE EXACT LOCATION OF THE DRY SLOT ON FRIDAY AND THE RESULTING SHOWER/THUNDERSTORM PATTERN TO THE EAST. RIGHT NOW IT LOOKS LIKE BAND OF PRECIP WILL CONTINUE SLOGGING EASTWARD OVERNIGHT, BUT WILL PROBABLY SLOW SOMEWHAT AS IT PUSHES TOWARD THE PLATEAU LATER TONIGHT. DEEPEST MOISTURE SHOULD BE OVER EASTERN MIDDLE TENNESSEE FRIDAY, WHERE DAYTIME INSTABILITY WILL BE GREATEST, ALONG WITH AT LEAST A SLIGHT CHANCE FOR SEVERE THUNDERSTORMS (ATTENDED BY HAIL AND DAMAGING STRAIGHT LINE WINDS). MEANWHILE, EXPECT WESTERN AREAS TO DRY OUT DURING THE DAY. AS CLOSED UPPER LOW PUSHES TO THE OHIO RIVER ON FRIDAY NIGHT, IT SHOULD BE ACCOMPANIED BY A CIRCULAR AREA OF CLOUDS SIMILAR TO WHAT WE`VE OBSERVED OVER THE PLAINS STATES TODAY. AS A RESULT EXPECT CLOUDS, ALONG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS, TO BE PRESENT IN A RELATIVELY BROAD SWATH TO THE SOUTH AND EAST OF THE LOW PRESSURE CENTER. ON SATURDAY, AS COLD CORE LOW DROPS EAST-SOUTHEASTWARD ACROSS THE TENNESSEE VALLEY, WE WILL SEE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS IN MIDDLE TENNESSEE. WITH COLDER AIR ALOFT, WOULD NOT BE SURPRISED TO SEE SOME "HAILERS" ON SATURDAY. SHOWERS FINALLY PULL EAST OF OUR AREA BY SUNDAY, AND GIVE WAY TO A SPELL OF DRY WEATHER SUNDAY THROUGH TUESDAY. A RIDGE OF HIGH PRESSURE BUILDS IN FROM THE WEST, ACCOMPANIED BY A WARMING TREND. FOLLOWING WEEKEND HIGH TEMPERATURES IN THE UPPER 60S TO LOWER 70S AT NASHVILLE, HIGHS WILL LIKELY PUSH BACK TO NEAR 80 DEGREES BY TUESDAY. LONG TERM...A SHORTWAVE WILL PUSH IN AND DAMPEN OUR FRIENDLY RIDGE BY THE MIDDLE-TO-LATTER PART OF NEXT WEEK, BRINGING ALONG ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1046 PM CDT SAT MAR 24 2012 .UPDATE... TEMPERATURES WERE RUNNING A BIT WARMER THAN PREVIOUSLY FORECAST OVER AREAS NORTHEAST OF THE DALLAS FORT WORTH METROPLEX. WILL INCREASE OVERNIGHT LOWS BY A FEW DEGREES IN THESE AREAS BASED ON TRENDS AND NEW GUIDANCE. OTHERWISE PATCHY FOG STILL LOOKS LIKE A POSSIBILITY PRIMARILY SOUTH OF I 20 BY SUNRISE. 30 && .AVIATION... FOR THE 00Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE VALID FORECAST PERIOD EXCEPT FOR THE POSSIBILITY OF SOME EARLY MORNING FOG AROUND WACO. A SURFACE RIDGE OF HIGH PRESSURE IN PLACE OVER NORTH TX WILL SLIDE SLOWLY OFF TO THE NORTHEAST THROUGH THE OVERNIGHT HRS. THIS WILL ALLOW FOR A RETURN OF SHALLOW MOISTURE TO THE AREA SOUTHWEST OF THE RIDGE AXIS BY SUNRISE. LATEST GUIDANCE INDICATES THAT THIS RETURN OF SHALLOW MOISTURE WILL REMAIN SOUTHWEST OF METROPLEX AREA TAF SITES...BUT WILL END UP AFFECTING THE WACO AREA JUST BEFORE SUNRISE. BASED ON LATEST RUC FORECAST SOUNDINGS DECIDED TO INCLUDE A FEW HRS OF IFR VSBYS AT KACT IN THE 11 TO 15Z TIMEFRAME AS A SHALLOW INVERSION OF TEMPERATURE AND MOISTURE IS INDICATED. WITH CLEAR SKIES AND LIGHT WIND IN PLACE THIS SET-UP SHOULD RESULT IN AREAS OF GROUND FOG WITHIN THIS TIMEFRAME. AFTER A COUPLE OF HOURS OF HEATING...EXPECT THIS SHALLOW INVERSION TO MIX OUT RESULTING IN A QUICK DISPERSION OF ANY GROUND FOG NEAR KACT. VFR CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE FORECAST PERIOD. CAVANAUGH && .PREV DISCUSSION... /ISSUED 336 PM CDT SAT MAR 24 2012/ SURFACE RIDGE AXIS REMAINS OVER THE EASTERN CWA WITH WEAK SOUTHERLY FLOW OVER THE WESTERN ZONES BEGINNING TO BRING HIGHER GULF MOISTURE NORTHWARD. DENSE FOG DEVELOPED OVER THE HILL CENTRAL AND SOUTHEAST TEXAS LAST NIGHT. EXPECT FOG TO DEVELOP AGAIN TONIGHT...THIS TIME A LITTLE FARTHER NORTH...PRIMARILY ALONG AND WEST OF THE BRAZOS RIVER VALLEY WHERE TONGUE OF HIGHER SURFACE MOISTURE WILL SET UP. ASIDE FROM ANY FOG...A GENERALLY CLEAR...CALM...AND COMFORTABLE NIGHT IS IN STORE. ANOTHER MILD AND PLEASANT DAY IS EXPECTED SUNDAY WITH HIGHS IN THE LOWER 80S. SURFACE RIDGE WILL SHIFT TO THE EAST BY SUNDAY NIGHT AND SOUTHERLY WINDS WILL GRADUALLY INCREASE TO 10-15 MPH BY MONDAY. AS A RESULT GULF MOISTURE AND OVERNIGHT LOW TEMPS SLOWLY INCREASE EARLY NEXT WEEK...BUT HIGH TEMPS REMAIN MILD. CLOUD COVER IS EXPECTED TO ARRIVE MONDAY NIGHT AND TUESDAY AS A SHORTWAVE TRACKS ACROSS COLORADO AND INTO THE NORTHERN PLAINS. A FEW STORMS MAY FIRE ALONG THE DRY LINE IN THE TX PANHANDLE MONDAY EVENING BUT THE FORCING REMAINS WELL NORTHWEST OF OUR AREA FOR ANY RAIN CHANCES HERE. MID-HIGH CLOUD COVER WILL BE MOST ABUNDANT ON TUESDAY WHICH MAY HOLD AFTERNOON HIGHS DOWN A DEGREE OR TWO FROM MONDAY/S READINGS. OTHERWISE WITH SOUTHERLY FLOW CONTINUING... EXPECT MORNING STRATUS AND AFTERNOON SUN WITH HIGHS NEAR 80 AND LOWS NEAR 60 FOR THE MIDWEEK PERIOD. MODELS ARE IN DECENT AGREEMENT IN THE SYNOPTIC PATTERN BY THE END OF THE WEEK. THE WESTERLIES ARE EXPECTED TO WEAKEN ACROSS THE REGION AS THE POLAR JET SETS UP OVER THE CANADIAN BORDER AND THE SUBTROPICAL JET BECOMES SITUATED ACROSS CENTRAL MEXICO. IN THE VOID BETWEEN THE TWO...IT APPEARS THE SYNOPTIC ENVIRONMENT WILL BE FAVORABLE FOR A SHORTWAVE TO INTENSIFY INTO A SLOW MOVING UPPER LOW OVER TEXAS BY FRIDAY. THE INTENSIFICATION OF THE SHORTWAVE INTO AN UPPER LOW RESULTS PRIMARILY FROM AN ATMOSPHERIC CONVECTIVE FEEDBACK...WHERE THE RELEASE OF LATENT HEAT FROM CONVECTION /NOT THERMAL GRADIENTS/ STRENGTHEN THE VORTEX. GFS/ECMWF/GEM ALL SHOW THIS UPPER LOW BECOMING A VERTICALLY STACKED AND WARM-CORE SYSTEM...WITH THE CYCLONIC CIRCULATION EXTENDING DOWN TO THE SURFACE. CYCLONES OF THIS NATURE ARE NOT UNCOMMON IN THE SUMMER MONTHS AND ARE NOTORIOUS FOR HEAVY RAIN. HOWEVER...SINCE THIS IS OCCURRING SO EARLY IN THE YEAR...MOISTURE/INSTABILITY CONTENT IS PROBABLY NOT HIGH ENOUGH TO RESULT IN SIGNIFICANT CONVECTION OR HEAVY RAINS. THE BEST CHANCES OF RAIN WILL PROBABLY OCCUR ON FRIDAY WHEN THE LOW IS OVERHEAD...BUT WILL BE CONSERVATIVE WITH POPS FOR NOW. HIGH TEMPS SHOULD COOL INTO THE 70S DUE TO CLOUD COVER AND SCATTERED RAIN SHOWERS...WITH LOWS IN THE LOW-MID 60S. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 57 83 59 83 61 / 0 0 0 0 10 WACO, TX 55 82 56 83 58 / 0 0 0 0 5 PARIS, TX 52 80 53 82 57 / 0 0 0 0 5 DENTON, TX 51 83 56 83 59 / 0 0 0 0 10 MCKINNEY, TX 50 81 53 81 57 / 0 0 0 0 10 DALLAS, TX 58 83 60 83 61 / 0 0 0 0 10 TERRELL, TX 51 82 55 82 58 / 0 0 0 0 5 CORSICANA, TX 57 83 56 82 58 / 0 0 0 0 5 TEMPLE, TX 56 83 56 83 57 / 0 0 0 0 5 MINERAL WELLS, TX 57 84 55 83 57 / 0 0 0 0 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 69/30
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1000 PM CDT SAT MAR 24 2012 .DISCUSSION...CURRENT OBS AND MSAS DATA INDICATE HIGHER SWATH OF MOISTURE LOCATED ALONG AND OFFSHORE OF THE SOUTHERN COASTAL BEND AND LOWER TEXAS COAST. THIS MOISTURE...ALBEIT SHALLOW...WILL CONTINUE TO ADVECT INLAND OVERNIGHT WITH STRATUS LIKELY TO DEVELOP ALONG WITH SOME FOG. NAM AND RUC PROG GREATEST FOG POTENTIAL TO BE LOCATED INLAND ALONG AND IN BETWEEN THE HWY 281 AND 77 CORRIDORS. CHANGES TO THE FORECAST WERE TO ALTER DIURNAL DROP OF HOURLY TEMPS ACROSS THE REGION TO SHOW MORE TEMPERATE COOLING THIS EVENING AND TO CHANGE DEWPOINTS TO REFLECT HIGHER MOISTURE VALUES MOVING ONSHORE. ALSO ENHANCED FOG WORKING SLIGHTLY FOR AREAS MENTIONED ABOVE. UPDATED PRODUCTS WILL BE OUT SHORTLY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 65 84 64 83 66 / 0 0 10 0 10 VICTORIA 61 83 60 84 62 / 0 0 10 0 10 LAREDO 68 91 68 90 69 / 0 10 10 10 10 ALICE 65 86 65 86 64 / 0 0 10 10 10 ROCKPORT 67 80 67 80 68 / 0 0 10 0 10 COTULLA 62 86 63 86 64 / 0 10 10 10 10 KINGSVILLE 65 83 65 85 65 / 0 0 10 0 10 NAVY CORPUS 68 79 66 79 69 / 0 0 10 0 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ UPDATE...HART/79
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
703 PM CDT SAT MAR 24 2012 .AVIATION... FOR THE 00Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE VALID FORECAST PERIOD EXCEPT FOR THE POSSIBILITY OF SOME EARLY MORNING FOG AROUND WACO. A SURFACE RIDGE OF HIGH PRESSURE IN PLACE OVER NORTH TX WILL SLIDE SLOWLY OFF TO THE NORTHEAST THROUGH THE OVERNIGHT HRS. THIS WILL ALLOW FOR A RETURN OF SHALLOW MOISTURE TO THE AREA SOUTHWEST OF THE RIDGE AXIS BY SUNRISE. LATEST GUIDANCE INDICATES THAT THIS RETURN OF SHALLOW MOISTURE WILL REMAIN SOUTHWEST OF METROPLEX AREA TAF SITES...BUT WILL END UP AFFECTING THE WACO AREA JUST BEFORE SUNRISE. BASED ON LATEST RUC FORECAST SOUNDINGS DECIDED TO INCLUDE A FEW HRS OF IFR VSBYS AT KACT IN THE 11 TO 15Z TIMEFRAME AS A SHALLOW INVERSION OF TEMPERATURE AND MOISTURE IS INDICATED. WITH CLEAR SKIES AND LIGHT WIND IN PLACE THIS SET-UP SHOULD RESULT IN AREAS OF GROUND FOG WITHIN THIS TIMEFRAME. AFTER A COUPLE OF HOURS OF HEATING...EXPECT THIS SHALLOW INVERSION TO MIX OUT RESULTING IN A QUICK DISPERSION OF ANY GROUND FOG NEAR KACT. VFR CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE FORECAST PERIOD. CAVANAUGH && .PREV DISCUSSION... /ISSUED 336 PM CDT SAT MAR 24 2012/ SURFACE RIDGE AXIS REMAINS OVER THE EASTERN CWA WITH WEAK SOUTHERLY FLOW OVER THE WESTERN ZONES BEGINNING TO BRING HIGHER GULF MOISTURE NORTHWARD. DENSE FOG DEVELOPED OVER THE HILL CENTRAL AND SOUTHEAST TEXAS LAST NIGHT. EXPECT FOG TO DEVELOP AGAIN TONIGHT...THIS TIME A LITTLE FARTHER NORTH...PRIMARILY ALONG AND WEST OF THE BRAZOS RIVER VALLEY WHERE TONGUE OF HIGHER SURFACE MOISTURE WILL SET UP. ASIDE FROM ANY FOG...A GENERALLY CLEAR...CALM...AND COMFORTABLE NIGHT IS IN STORE. ANOTHER MILD AND PLEASANT DAY IS EXPECTED SUNDAY WITH HIGHS IN THE LOWER 80S. SURFACE RIDGE WILL SHIFT TO THE EAST BY SUNDAY NIGHT AND SOUTHERLY WINDS WILL GRADUALLY INCREASE TO 10-15 MPH BY MONDAY. AS A RESULT GULF MOISTURE AND OVERNIGHT LOW TEMPS SLOWLY INCREASE EARLY NEXT WEEK...BUT HIGH TEMPS REMAIN MILD. CLOUD COVER IS EXPECTED TO ARRIVE MONDAY NIGHT AND TUESDAY AS A SHORTWAVE TRACKS ACROSS COLORADO AND INTO THE NORTHERN PLAINS. A FEW STORMS MAY FIRE ALONG THE DRY LINE IN THE TX PANHANDLE MONDAY EVENING BUT THE FORCING REMAINS WELL NORTHWEST OF OUR AREA FOR ANY RAIN CHANCES HERE. MID-HIGH CLOUD COVER WILL BE MOST ABUNDANT ON TUESDAY WHICH MAY HOLD AFTERNOON HIGHS DOWN A DEGREE OR TWO FROM MONDAY/S READINGS. OTHERWISE WITH SOUTHERLY FLOW CONTINUING... EXPECT MORNING STRATUS AND AFTERNOON SUN WITH HIGHS NEAR 80 AND LOWS NEAR 60 FOR THE MIDWEEK PERIOD. MODELS ARE IN DECENT AGREEMENT IN THE SYNOPTIC PATTERN BY THE END OF THE WEEK. THE WESTERLIES ARE EXPECTED TO WEAKEN ACROSS THE REGION AS THE POLAR JET SETS UP OVER THE CANADIAN BORDER AND THE SUBTROPICAL JET BECOMES SITUATED ACROSS CENTRAL MEXICO. IN THE VOID BETWEEN THE TWO...IT APPEARS THE SYNOPTIC ENVIRONMENT WILL BE FAVORABLE FOR A SHORTWAVE TO INTENSIFY INTO A SLOW MOVING UPPER LOW OVER TEXAS BY FRIDAY. THE INTENSIFICATION OF THE SHORTWAVE INTO AN UPPER LOW RESULTS PRIMARILY FROM AN ATMOSPHERIC CONVECTIVE FEEDBACK...WHERE THE RELEASE OF LATENT HEAT FROM CONVECTION /NOT THERMAL GRADIENTS/ STRENGTHEN THE VORTEX. GFS/ECMWF/GEM ALL SHOW THIS UPPER LOW BECOMING A VERTICALLY STACKED AND WARM-CORE SYSTEM...WITH THE CYCLONIC CIRCULATION EXTENDING DOWN TO THE SURFACE. CYCLONES OF THIS NATURE ARE NOT UNCOMMON IN THE SUMMER MONTHS AND ARE NOTORIOUS FOR HEAVY RAIN. HOWEVER...SINCE THIS IS OCCURRING SO EARLY IN THE YEAR...MOISTURE/INSTABILITY CONTENT IS PROBABLY NOT HIGH ENOUGH TO RESULT IN SIGNIFICANT CONVECTION OR HEAVY RAINS. THE BEST CHANCES OF RAIN WILL PROBABLY OCCUR ON FRIDAY WHEN THE LOW IS OVERHEAD...BUT WILL BE CONSERVATIVE WITH POPS FOR NOW. HIGH TEMPS SHOULD COOL INTO THE 70S DUE TO CLOUD COVER AND SCATTERED RAIN SHOWERS...WITH LOWS IN THE LOW-MID 60S. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 56 83 59 83 61 / 0 0 0 0 10 WACO, TX 55 82 56 83 58 / 0 0 0 0 5 PARIS, TX 49 80 53 82 57 / 0 0 0 0 5 DENTON, TX 51 83 56 83 59 / 0 0 0 0 10 MCKINNEY, TX 49 81 53 81 57 / 0 0 0 0 10 DALLAS, TX 57 83 60 83 61 / 0 0 0 0 10 TERRELL, TX 51 82 55 82 58 / 0 0 0 0 5 CORSICANA, TX 55 83 56 82 58 / 0 0 0 0 5 TEMPLE, TX 57 83 56 83 57 / 0 0 0 0 5 MINERAL WELLS, TX 53 84 55 83 57 / 0 0 0 0 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
152 PM EDT FRI MAR 23 2012 .SYNOPSIS... A LOW PRESSURE SYSTEM WILL TRACK EAST OUT OF THE MID MISSISSIPPI VALLEY TODAY...THEN SOUTHEAST ACROSS THE TENNESSEE VALLEY ON SATURDAY. BY MONDAY THE SYSTEM WILL BE OFF THE EAST COAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 130 PM EDT FRIDAY... CONVECTION DEVELOPING IN UNSTABLE AIR THIS AFTERNOON ACROSS THE WESTERN MOUNTAINS. ADJUSTED POPS AND TEMPERATURES FOR LATEST TRENDS. AS OF 1140 AM EDT FRIDAY... ADJUSTED THE ONSET OF CONVECTION AND RAISED TEMPERATURES A FEW DEGREES THIS AFTERNOON. PLAYED EARLY POPS CLOSE TO HRRR THIS AFTERNOON. ADJUSTMENTS MADE IN CLOUD COVER THIS AFTERNOON INTO TONIGHT. AS OF 925 AM EDT FRIDAY... THE UPPER LOW OVER THE PLAINS WILL MOVE SLOWLY EASTWARD THIS AFTERNOON AND TONIGHT...THIS WILL PUSH AN OCCLUDED SURFACE FRONT AND ASSOCIATED MOISTURE EASTWARD. THIS MORNING WRFARW-RNK AND NAM BRINGS SOME CONVECTION INTO THE WEST THIS AFTERNOON AND SPREAD STORMS EAST TONIGHT. EXPECT ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON MAINLY WEST OF I77...THEN BETTER COVERAGE ANTICIPATED AFTER 8PM/00Z TONIGHT. AS PREVIOUS SHIFT POINT OUT...THE THREAT OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY THIS EVENING INTO SATURDAY AS THE UPPER LOW AND COLD POOL GET CLOSER. THE DAY2 CONVECTIVE OUTLOOK PLACES EAST OF THE MOUNTAINS IN A SLIGHT RISK ON SATURDAY. MADE SOME MINOR ADJUSTMENTS IN ISC GRIDS FOR TEMPERATURES...AND POPS FOR THIS AFTERNOON. AS OF 400 AM EDT FRIDAY... MODELS SIMILAR WITH TIMING OF APPROACHING OCCLUDED FRONT AND ASSOCIATED PRECIPITATION. THERE MAY BE ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON BUT THE BETTER PROBABILITY AND COVERAGE OF PRECIPITATION WILL BE AFTER 8PM/00Z TONIGHT. THE THREAT OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY THIS EVENING AS THE UPPER LOW AND COLD POOL GET CLOSER. MADE ONLY MINOR ADJUSTMENTS FOR HIGHS TODAY. STAYED CLOSE TO LAMP GUIDANCE. MILD DEW POINTS AND CLOUDS COVER WILL HOLD TEMPERATURES UP TONIGHT. USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 400 AM EDT FRIDAY... STRONG CYCLONE WHICH HAS BEEN QUASI-STATIONARY OVER THE SOUTHERN PLAINS WILL FINALLY TRACK EAST AND ACROSS THE MID ATLANTIC REGION THIS WEEKEND. THIS FEATURE IS EXPECTED TO SLOWLY TREK ACROSS THE AREA SATURDAY AND SUNDAY WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. INITIAL WAVE OF PRECIP SHOULD HAVE PASSED THROUGH THE CWA BY 12 UTC...8AM SATURDAY...ASSOCIATED WITH THE OCCLUDED SURFACE FRONT. WITH PASSAGE OF OCCLUSION...SHOULD SEE A BREAK IN THE PRECIP WITH STRONG INDICATION THAT A DRY SLOT WILL WORK ACROSS THE FCST AREA PRIOR TO ARRIVAL OF PRECIP UNDERNEATH THE UPPER LOW. IF THIS BREAK IN PRECIP ASSOCIATED WITH THE DRY SLOT REVEALS ANY CLEARING...THEN SOLAR INSOLATION LIKELY TO INCREASE INSTABILITY ACROSS THE CWA INCREASING POTENTIAL FOR SEVERE STORMS. IF THIS TURNS OUT TO BE THE CASE...WILL THEN NEED TO ENTERTAIN POSSIBILITY OF SUPERCELLS PER INCREASING DEEP LAYER SHEAR AHEAD OF THE APPROACHING UPPER VORTEX. WILL DEFER TO THE STORM PREDICTION CENTER FOR GUIDANCE ON THIS DEVELOPING SITUATION...BUT IT APPEARS THE GREATEST THREAT FOR SEVERE WEATHER MAY RESIDE JUST SOUTH OF THE FCST AREA. FOR SATURDAY NIGHT AND SUNDAY THE UPPER LOW IS PROGGED TO PASS DIRECTLY OVER THE MID ATLANTIC REGION...THE CENTER OF THE LOW SPIRALING EAST AND OFF THE COAST SUNDAY NIGHT. FOCUS SATURDAY NIGHT THROUGH SUNDAY WILL BE FOR SCATTERED TO NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORMS...THE THREAT FOR PRECIP PERSISTING UNTIL THE STORM SYSTEM PASSES EAST OF THE REGION SUNDAY NIGHT. TEMPERATURES WILL TREND DOWNWARD OVER THE WEEKEND...SATURDAY BEING THE WARMER OF THE TWO DAYS WITH READINGS IN THE 70S PENDING A BIT OF SUN. SHAVE ABOUT 10 DEGREES OFF THE TMAX FOR SUNDAY COMPARED TO SATURDAY...SUNDAY STILL TOPPING OUT 4-8 DEGREES ABOVE THE NORM. QPF FOR THE ENTIRE EVENT...NOON FRIDAY THROUGH MIDNIGHT SUNDAY NIGHT LOOKS TO BE ON THE ORDER OF ONE TO TWO INCHES...THE HIGHER AMOUNTS FAVORING CONVEYOR BELT OF DEEPER MOISTURE THAT WILL RESIDE ON THE NORTH SIDE OF THE CYCLONE. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 400 AM EDT FRIDAY... CYCLONE IS PROGGED TO BE WELL EAST OF THE AREA BY 12Z MONDAY... BOOTED OUT TO SEA BY A STRONG NORTHERN STREAM TROF THAT WILL DIVE SOUTHEAST ACROSS NEW ENGLAND FROM EASTERN CANADA. THE COMBINATION OF THE EXITING CYCLONE AND TROF OVER NEW ENGLAND WILL BRING BREEZY CONDITIONS TO THE AREA MONDAY AND MONDAY NIGHT...FOLLOWED BY A SUNNY DRY DAY FOR TUESDAY. TEMPERATURES WILL BEGIN TO MODERATE TUESDAY...WITH A MORE SIGNIFICANT REBOUND WEDNESDAY AS THE LOW LEVEL FLOW BECOMES SOUTHWESTERLY. ATTM WILL MAINTAIN A DRY FORECAST FOR MIDWEEK BUT WILL HAVE TO KEEP EYES ON FAST MOVING FRONT WHICH IS PROGGED TO MOVE ACROSS THE OHIO VALLEY WEDNESDAY...POSSIBLY ARRIVING ACROSS OUR THE MTNS AS EARLY AS WEDNESDAY AFTERNOON. THIS SOLUTION IS ABOUT 12-18 HOURS FASTER THAN PREVIOUS MODEL RUNS. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 1140 AM EDT FRIDAY... THIS MORNING PATCHY FOG DISSIPATED QUICKLY...LEAVING PLENTY OF SUNSHINE. CLOUDS WILL FILL IN FROM WEST TO EAST THIS AFTERNOON INTO TONIGHT WITH CEILINGS LOWERING TONIGHT. MODERATE CONFIDENCE THAT CEILINGS WILL REMAIN VFR AS THE PRECIPITATION BEGINS. AFTER 00Z TONIGHT...THERE IS A CHANCE THAT BLF AND LWB MAY HAVE MVFR/IFR CEILINGS AND VISIBILITIES WITH CONVECTION AND LOW CLOUDS. MODELS BRING PRECIPITATION ASSOCIATED WITH THE CLOSED UPPER LOW OVER THE MIDWEST INTO THE FORECAST AREA AFTER 00Z. MORE WIDESPREAD RAIN IS EXPECTED SATURDAY THROUGH SUNDAY AS THE LOW MOVES EAST THEN SOUTHEAST. DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THE SYSTEM SUNDAY NIGHT THROUGH TUESDAY. && .CLIMATE... RECORD HIGH TEMPS FOR TODAY... 3/23 ROANOKE 82 IN 2007 LYNCHBURG 91 IN 2007 DANVILLE 86 IN 1966 BLUEFIELD 77 IN 2007 BLACKSBURG 80 IN 1966 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...PM LONG TERM...WP AVIATION...AMS CLIMATE...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1147 AM EDT FRI MAR 23 2012 .SYNOPSIS... A LOW PRESSURE SYSTEM WILL TRACK EAST OUT OF THE MID MISSISSIPPI VALLEY TODAY...THEN SOUTHEAST ACROSS THE TENNESSEE VALLEY ON SATURDAY. BY MONDAY THE SYSTEM WILL BE OFF THE EAST COAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1140 AM EDT FRIDAY... ADJUSTED THE ONSET OF CONVECTION AND RAISED TEMPERATURES A FEW DEGREES THIS AFTERNOON. PLAYED EARLY POPS CLOSE TO HRRR THIS AFTERNOON. ADJUSTMENTS MADE IN CLOUD COVER THIS AFTERNOON INTO TONIGHT. AS OF 925 AM EDT FRIDAY... THE UPPER LOW OVER THE PLAINS WILL MOVE SLOWLY EASTWARD THIS AFTERNOON AND TONIGHT...THIS WILL PUSH AN OCCLUDED SURFACE FRONT AND ASSOCIATED MOISTURE EASTWARD. THIS MORNING WRFARW-RNK AND NAM BRINGS SOME CONVECTION INTO THE WEST THIS AFTERNOON AND SPREAD STORMS EAST TONIGHT. EXPECT ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON MAINLY WEST OF I77...THEN BETTER COVERAGE ANTICIPATED AFTER 8PM/00Z TONIGHT. AS PREVIOUS SHIFT POINT OUT...THE THREAT OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY THIS EVENING INTO SATURDAY AS THE UPPER LOW AND COLD POOL GET CLOSER. THE DAY2 CONVECTIVE OUTLOOK PLACES EAST OF THE MOUNTAINS IN A SLIGHT RISK ON SATURDAY. MADE SOME MINOR ADJUSTMENTS IN ISC GRIDS FOR TEMPERATURES...AND POPS FOR THIS AFTERNOON. AS OF 400 AM EDT FRIDAY... MODELS SIMILAR WITH TIMING OF APPROACHING OCCLUDED FRONT AND ASSOCIATED PRECIPITATION. THERE MAY BE ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON BUT THE BETTER PROBABILITY AND COVERAGE OF PRECIPITATION WILL BE AFTER 8PM/00Z TONIGHT. THE THREAT OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY THIS EVENING AS THE UPPER LOW AND COLD POOL GET CLOSER. MADE ONLY MINOR ADJUSTMENTS FOR HIGHS TODAY. STAYED CLOSE TO LAMP GUIDANCE. MILD DEW POINTS AND CLOUDS COVER WILL HOLD TEMPERATURES UP TONIGHT. USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 400 AM EDT FRIDAY... STRONG CYCLONE WHICH HAS BEEN QUASI-STATIONARY OVER THE SOUTHERN PLAINS WILL FINALLY TRACK EAST AND ACROSS THE MID ATLANTIC REGION THIS WEEKEND. THIS FEATURE IS EXPECTED TO SLOWLY TREK ACROSS THE AREA SATURDAY AND SUNDAY WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. INITIAL WAVE OF PRECIP SHOULD HAVE PASSED THROUGH THE CWA BY 12 UTC...8AM SATURDAY...ASSOCIATED WITH THE OCCLUDED SURFACE FRONT. WITH PASSAGE OF OCCLUSION...SHOULD SEE A BREAK IN THE PRECIP WITH STRONG INDICATION THAT A DRY SLOT WILL WORK ACROSS THE FCST AREA PRIOR TO ARRIVAL OF PRECIP UNDERNEATH THE UPPER LOW. IF THIS BREAK IN PRECIP ASSOCIATED WITH THE DRY SLOT REVEALS ANY CLEARING...THEN SOLAR INSOLATION LIKELY TO INCREASE INSTABILITY ACROSS THE CWA INCREASING POTENTIAL FOR SEVERE STORMS. IF THIS TURNS OUT TO BE THE CASE...WILL THEN NEED TO ENTERTAIN POSSIBILITY OF SUPERCELLS PER INCREASING DEEP LAYER SHEAR AHEAD OF THE APPROACHING UPPER VORTEX. WILL DEFER TO THE STORM PREDICTION CENTER FOR GUIDANCE ON THIS DEVELOPING SITUATION...BUT IT APPEARS THE GREATEST THREAT FOR SEVERE WEATHER MAY RESIDE JUST SOUTH OF THE FCST AREA. FOR SATURDAY NIGHT AND SUNDAY THE UPPER LOW IS PROGGED TO PASS DIRECTLY OVER THE MID ATLANTIC REGION...THE CENTER OF THE LOW SPIRALING EAST AND OFF THE COAST SUNDAY NIGHT. FOCUS SATURDAY NIGHT THROUGH SUNDAY WILL BE FOR SCATTERED TO NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORMS...THE THREAT FOR PRECIP PERSISTING UNTIL THE STORM SYSTEM PASSES EAST OF THE REGION SUNDAY NIGHT. TEMPERATURES WILL TREND DOWNWARD OVER THE WEEKEND...SATURDAY BEING THE WARMER OF THE TWO DAYS WITH READINGS IN THE 70S PENDING A BIT OF SUN. SHAVE ABOUT 10 DEGREES OFF THE TMAX FOR SUNDAY COMPARED TO SATURDAY...SUNDAY STILL TOPPING OUT 4-8 DEGREES ABOVE THE NORM. QPF FOR THE ENTIRE EVENT...NOON FRIDAY THROUGH MIDNIGHT SUNDAY NIGHT LOOKS TO BE ON THE ORDER OF ONE TO TWO INCHES...THE HIGHER AMOUNTS FAVORING CONVEYOR BELT OF DEEPER MOISTURE THAT WILL RESIDE ON THE NORTH SIDE OF THE CYCLONE. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 400 AM EDT FRIDAY... CYCLONE IS PROGGED TO BE WELL EAST OF THE AREA BY 12Z MONDAY... BOOTED OUT TO SEA BY A STRONG NORTHERN STREAM TROF THAT WILL DIVE SOUTHEAST ACROSS NEW ENGLAND FROM EASTERN CANADA. THE COMBINATION OF THE EXITING CYCLONE AND TROF OVER NEW ENGLAND WILL BRING BREEZY CONDITIONS TO THE AREA MONDAY AND MONDAY NIGHT...FOLLOWED BY A SUNNY DRY DAY FOR TUESDAY. TEMPERATURES WILL BEGIN TO MODERATE TUESDAY...WITH A MORE SIGNIFICANT REBOUND WEDNESDAY AS THE LOW LEVEL FLOW BECOMES SOUTHWESTERLY. ATTM WILL MAINTAIN A DRY FORECAST FOR MIDWEEK BUT WILL HAVE TO KEEP EYES ON FAST MOVING FRONT WHICH IS PROGGED TO MOVE ACROSS THE OHIO VALLEY WEDNESDAY...POSSIBLY ARRIVING ACROSS OUR THE MTNS AS EARLY AS WEDNESDAY AFTERNOON. THIS SOLUTION IS ABOUT 12-18 HOURS FASTER THAN PREVIOUS MODEL RUNS. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... AS OF 1140 AM EDT FRIDAY... THIS MORNING PATCHY FOG DISSIPATED QUICKLY...LEAVING PLENTY OF SUNSHINE. CLOUDS WILL FILL IN FROM WEST TO EAST THIS AFTERNOON INTO TONIGHT WITH CEILINGS LOWERING TONIGHT. MODERATE CONFIDENCE THAT CEILINGS WILL REMAIN VFR AS THE PRECIPITATION BEGINS. AFTER 00Z TONIGHT...THERE IS A CHANCE THAT BLF AND LWB MAY HAVE MVFR CEILINGS AND VISIBILITIES WITH CONVECTION AND LOW CLOUDS. MODELS BRING PRECIPITATION ASSOCIATED WITH THE CLOSED UPPER LOW OVER THE MIDWEST INTO THE FORECAST AREA AFTER 00Z. MORE WIDESPREAD RAIN IS EXPECTED SATURDAY THROUGH SUNDAY AS THE LOW MOVES EAST THEN SOUTHEAST. DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THE SYSTEM SUNDAY NIGHT THROUGH TUESDAY. && .CLIMATE... RECORD HIGH TEMPS FOR TODAY... 3/23 ROANOKE 82 IN 2007 LYNCHBURG 91 IN 2007 DANVILLE 86 IN 1966 BLUEFIELD 77 IN 2007 BLACKSBURG 80 IN 1966 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...PM LONG TERM...WP AVIATION...AMS CLIMATE...
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1054 PM CDT SAT MAR 24 2012 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND SUNDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LARGE CUT-OFF LOW PRESSURE SYSTEM MOVING SE OVER KENTUCKY AND TENNESSEE EARLY THIS AFTERNOON...WHILE A SHORTWAVE OVER LAKE WINNIPEG IS DRIVING A COLD FRONT OVER THE NORTHERN MISSISSIPPI VALLEY. BETWEEN THESE FEATURES...CYCLONIC FLOW IS MAINTAINING A FAIRLY EXPANSIVE STRATO-CU DECK OVER THE WESTERN GREAT LAKES. SOME BREAKS IN THE STRATUS ARE GROWING LARGER OVER NW WISCONSIN WHERE A DRIER AIRMASS EXISTS ALOFT. AS THE COLD FRONT MOVES ACROSS THE REGION LATE TONIGHT INTO SUNDAY MORNING...CLOUDS AND FOG ARE THE MAIN FORECAST CONCERNS. TONIGHT...LOW CLOUDS SHOULD BE HANGING AROUND MUCH OF NORTHEAST AND INTO CENTRAL WISCONSIN FOR THE EARLY PART OF THE EVENING...WHERE MOISTURE IS DEEPER THROUGH THE COLUMN AND WEAK LOW LEVEL CONVERGENCE LINGERS. EVENTUALLY THOUGH...UPSTREAM DRIER AIR WILL MAKE INROADS OVER NORTH-CENTRAL WISCONSIN INTO NORTHEAST WISCONSIN THROUGH THE EVENING. HAVE LEFT SKY CONDITIONS SCATTERED-WEST TO BROKEN-EAST WITH THE UNCERTAINTY OF COVERAGE. COLD FRONT OVER THE NORTHERN MISSISSIPPI VALLEY WILL MOVE ACROSS THE AREA AFTER MIDNIGHT. FAIRLY WIDESPREAD STRATUS DECK BEHIND THE FRONT SO WILL SHOW SKIES RETURNING TO BROKEN AS THE BOUNDARY WORKS THROUGH. THE PRESSURE GRADIENT WILL TIGHTEN UP BEHIND THE FRONT AS WELL...WHICH WILL HELP DISSIPATE ANY FOG. LOWS RANGING FROM THE UPPER 30S NORTH TO THE UPPER 40S SOUTH. SUNDAY...THE COLD FRONT WILL MOVE SOUTHEAST ACROSS CENTRAL AND NORTHEAST WISCONSIN DURING THE MORNING...THEN CLEAR THE REGION FOR THE AFTERNOON. A VERY DRY AIRMASS WILL BE ARRIVING BEHIND THE COLD FRONT...SO WILL SEE AMPLE SUNSHINE MOVING IN BEHIND THE STRATUS ALONG THE FRONT. LOWERED DEWPOINTS OVER N-C WISCONSIN FOR THE AFTERNOON WHERE TEMPS WILL ONLY REACH INTO THE LOWER AND MIDDLE 50S. CENTRAL AND EAST-CENTRAL WISCONSIN SHOULD SEE HIGHS IN THE LOWER TO MIDDLE 60S. .LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. THE WARM PATTERN WILL CONTINUE NEXT WEEK...THOUGH NOT QUITE AS WARM AS THE LAST FEW WEEKS. LOWS AND HIGHS OF 5 TO 10 DEGREES ABOVE NORMAL ARE EXPECTED ON MOST DAYS BUT THAT WILL LIKELY FEEL CHILLY AFTER TEMPERATURES IN THE 70S AND 80S EARLIER THIS WEEK. NOT MUCH IN THE WAY OF PRECIPITATION IS EXPECTED AND ALL OR NEARLY ALL WILL BE RAIN. THE FIRST CHANCE OF PRECIPITATION IS MONDAY AS MID LEVEL WARM ADVECTION MOVES ACROSS THE AREA. WHATEVER FALLS SHOULD BE MOSTLY IN CENTRAL WISCONSIN AND BE MOSTLY SPRINKLES OR VERY LIGHT SHOWERS. BETTER CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY NIGHT AND TUESDAY AS DECENT UPPER LOW LIFTS NORTHEAST FROM THE PLAINS. THERE MAY BE ENOUGH COLD AIR NEAR THE GROUND FOR THE PRECIPITATION TO FALL AS SLEET IN NORTHCENTRAL WISCONSIN LATE MONDAY NIGHT AND EARLY TUESDAY. ANOTHER CHANCE OF SHOWERS THURSDAY NIGHT AND FRIDAY AS A WEAK SYSTEM PASSES BY TO THE NORTH. OTHERWISE GENERALLY MILD AND DRY WEATHER. A FROST OR FREEZE IS LIKELY SUNDAY NIGHT. WHILE THIS IS USUALLY NOT NOTEWORTHY AT THIS TIME OF THE YEAR...IT MAY BE A CONCERN FOR ORCHARD OWNERS AS SOEM TREES HAVE BEGUN FLOWERING DUE TO THE RECENT RECORD WARMTH. && .AVIATION...SCT-OVC STRATOCUMULUS WITH BASES IN THE 4-6K FT RANGE WERE OBSERVED ACROSS THE FORECAST AREA LATE THIS EVENING. WHERE SKIES HAD TEMPORARILY CLEARED...PATCHY FOG DEVELOPED. THE FOG WAS LOCALLY DENSE. THE PATCHY FOG SHOULD CONTINUE UNTIL THE WINDS PICK UP AND DRIER AIR ARRIVES IN THE WAKE OF A COLD FRONT LATER TONIGHT. LOW CLOUDS OVER NE MN HAVE BEEN SLOW TO MOVE TOWARD THE AREA THIS EVENING...BUT STILL THINK THEY MAKE IT INTO AT LEAST PART OF THE FORECAST AREA LATER TONIGHT. WILL MENTION SCT-BKN015 IN THE TAFS LATE TONIGHT INTO EARLY SUNDAY. DRY AIR BEHIND THE FRONT SHOULD ERODE ANY MVFR CIGS BY MID-MORNING SUNDAY...LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY. GUSTY NE WINDS MAY DEVELOP IN THE FOX VALLEY/LAKESHORE AREAS LATE SUNDAY AFTERNOON AND EVENING. KIECKBUSCH && .MARINE... A COLD FRONT MOVING ACROSS THE AREA WILL BRING GUSTY NORTHEAST WINDS TO THE AREA SUNDAY NIGHT AND EARLY MONDAY. FUNNELING DOWN THE BAY COULD PRODUCE GUSTS TO 25 TO 30 KNOTS NEAR GREEN BAY. A WARM FRONT WILL PUSH NORTHWARD ACROSS THE AREA TUESDAY. GUSTS TO NEAR GALE FORCE FROM THE SOUTHEAST ARE POSSIBLE ON TUESDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
653 PM CDT SAT MAR 24 2012 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND SUNDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LARGE CUT-OFF LOW PRESSURE SYSTEM MOVING SE OVER KENTUCKY AND TENNESSEE EARLY THIS AFTERNOON...WHILE A SHORTWAVE OVER LAKE WINNIPEG IS DRIVING A COLD FRONT OVER THE NORTHERN MISSISSIPPI VALLEY. BETWEEN THESE FEATURES...CYCLONIC FLOW IS MAINTAINING A FAIRLY EXPANSIVE STRATO-CU DECK OVER THE WESTERN GREAT LAKES. SOME BREAKS IN THE STRATUS ARE GROWING LARGER OVER NW WISCONSIN WHERE A DRIER AIRMASS EXISTS ALOFT. AS THE COLD FRONT MOVES ACROSS THE REGION LATE TONIGHT INTO SUNDAY MORNING...CLOUDS AND FOG ARE THE MAIN FORECAST CONCERNS. TONIGHT...LOW CLOUDS SHOULD BE HANGING AROUND MUCH OF NORTHEAST AND INTO CENTRAL WISCONSIN FOR THE EARLY PART OF THE EVENING...WHERE MOISTURE IS DEEPER THROUGH THE COLUMN AND WEAK LOW LEVEL CONVERGENCE LINGERS. EVENTUALLY THOUGH...UPSTREAM DRIER AIR WILL MAKE INROADS OVER NORTH-CENTRAL WISCONSIN INTO NORTHEAST WISCONSIN THROUGH THE EVENING. HAVE LEFT SKY CONDITIONS SCATTERED-WEST TO BROKEN-EAST WITH THE UNCERTAINTY OF COVERAGE. COLD FRONT OVER THE NORTHERN MISSISSIPPI VALLEY WILL MOVE ACROSS THE AREA AFTER MIDNIGHT. FAIRLY WIDESPREAD STRATUS DECK BEHIND THE FRONT SO WILL SHOW SKIES RETURNING TO BROKEN AS THE BOUNDARY WORKS THROUGH. THE PRESSURE GRADIENT WILL TIGHTEN UP BEHIND THE FRONT AS WELL...WHICH WILL HELP DISSIPATE ANY FOG. LOWS RANGING FROM THE UPPER 30S NORTH TO THE UPPER 40S SOUTH. SUNDAY...THE COLD FRONT WILL MOVE SOUTHEAST ACROSS CENTRAL AND NORTHEAST WISCONSIN DURING THE MORNING...THEN CLEAR THE REGION FOR THE AFTERNOON. A VERY DRY AIRMASS WILL BE ARRIVING BEHIND THE COLD FRONT...SO WILL SEE AMPLE SUNSHINE MOVING IN BEHIND THE STRATUS ALONG THE FRONT. LOWERED DEWPOINTS OVER N-C WISCONSIN FOR THE AFTERNOON WHERE TEMPS WILL ONLY REACH INTO THE LOWER AND MIDDLE 50S. CENTRAL AND EAST-CENTRAL WISCONSIN SHOULD SEE HIGHS IN THE LOWER TO MIDDLE 60S. .LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. THE WARM PATTERN WILL CONTINUE NEXT WEEK...THOUGH NOT QUITE AS WARM AS THE LAST FEW WEEKS. LOWS AND HIGHS OF 5 TO 10 DEGREES ABOVE NORMAL ARE EXPECTED ON MOST DAYS BUT THAT WILL LIKELY FEEL CHILLY AFTER TEMPERATURES IN THE 70S AND 80S EARLIER THIS WEEK. NOT MUCH IN THE WAY OF PRECIPITATION IS EXPECTED AND ALL OR NEARLY ALL WILL BE RAIN. THE FIRST CHANCE OF PRECIPITATION IS MONDAY AS MID LEVEL WARM ADVECTION MOVES ACROSS THE AREA. WHATEVER FALLS SHOULD BE MOSTLY IN CENTRAL WISCONSIN AND BE MOSTLY SPRINKLES OR VERY LIGHT SHOWERS. BETTER CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY NIGHT AND TUESDAY AS DECENT UPPER LOW LIFTS NORTHEAST FROM THE PLAINS. THERE MAY BE ENOUGH COLD AIR NEAR THE GROUND FOR THE PRECIPITATION TO FALL AS SLEET IN NORTHCENTRAL WISCONSIN LATE MONDAY NIGHT AND EARLY TUESDAY. ANOTHER CHANCE OF SHOWERS THURSDAY NIGHT AND FRIDAY AS A WEAK SYSTEM PASSES BY TO THE NORTH. OTHERWISE GENERALLY MILD AND DRY WEATHER. A FROST OR FREEZE IS LIKELY SUNDAY NIGHT. WHILE THIS IS USUALLY NOT NOTEWORTHY AT THIS TIME OF THE YEAR...IT MAY BE A CONCERN FOR ORCHARD OWNERS AS SOEM TREES HAVE BEGUN FLOWERING DUE TO THE RECENT RECORD WARMTH. && .AVIATION...ALTHOUGH SOME CLEARING OCCURRED OVER NE/EC WI LATE THIS AFTERNOON...SOME MVFR CIGS LINGERED OVER MUCH OF C/NC WI. EXPECT THE MVFR CIGS TO GRADUALLY BREAK UP EARLY THIS EVENING. WITH DEW POINTS STILL IN THE MID 40S TO LOWER 50S...PARTIAL CLEARING AND LIGHT WINDS COULD LEAD TO SOME PATCHY FOG DEVELOPMENT BY MID TO LATE EVENING. HAVE OPTED TO LEAVE THIS OUT OF THE TAFS FOR NOW...AND WATCH THE OBSERVATIONS THIS EVENING. UPSTREAM COLD FRONT OVER NW WI WILL MOVE ACROSS THE AREA DURING THE LATE EVENING AND OVERNIGHT HOURS. EXPECT MVFR AND LOCAL IFR CIGS TO ARRIVE A FEW HOURS AFTER THE FRONTAL PASSAGE...WITH WINDS GRADUALLY PICKING UP FROM THE NORTH. AMPLE DRY AIR BEHIND THE FRONT WILL ERODE THE MVFR CIGS LATE TONIGHT INTO MID-MORNING SUNDAY...LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY. KIECKBUSCH && .MARINE... A COLD FRONT MOVING ACROSS THE AREA WILL BRING GUSTY NORTHEAST WINDS TO THE AREA SUNDAY NIGHT AND EARLY MONDAY. FUNNELING DOWN THE BAY COULD PRODUCE GUSTS TO 25 TO 30 KNOTS NEAR GREEN BAY. A WARM FRONT WILL PUSH NORTHWARD ACROSS THE AREA TUESDAY. GUSTS TO NEAR GALE FORCE FROM THE SOUTHEAST ARE POSSIBLE ON TUESDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1104 PM MDT SAT MAR 24 2012 .AVIATION... VFR CONDITIONS EXPECTED AT TAF SITES OVER NEXT 24 HOURS. LOW LEVEL MOISTURE ADVECTING INTO EASTERN CO MAY RESULT IN SOME IFR-LIFR CIGS/VIS IN FOG EAST OF KLHX AFTER 08Z. WITH LIGHT NORTH TO NORTHWEST WINDS EXPECTED AT KCOS AND KPUB...LOW CIGS/FOG SHOULD STAY EAST OF BOTH TERMINALS...HOWEVER EACH MODEL RUN SEEMS TO ADVANCE FOG POTENTIAL WESTWARD SO THIS WILL BE MONITORED CLOSELY THROUGH THE EARLY AM HOURS. OTHERWISE...EXPECT SOME SCT-BKN200 CIRRUS THROUGH SUNDAY. WINDS WILL INCREASE FROM THE SOUTH TO SOUTHWEST AT 12-24 KTS AT ALL 3 TERMINALS SUNDAY AFTERNOON. -KT && .PREV DISCUSSION... /ISSUED 927 PM MDT SAT MAR 24 2012/ UPDATE... UPDATED FORECAST TO PUT OUT A DENSE FOG ADVISORY FOR KIOWA COUNTY...AND TO EXPAND AREAS OF FOG WESTWARD ACROSS CROWLEY AND OTERO COUNTIES. LATEST SFC OBS ALREADY SHOWING DEW POINTS IN THE UPPER 40S ADVECTING WESTWARD INTO SOUTHEAST CO. WITH FAIRLY STRONG EAST TO SOUTHEAST WINDS...EXPECT SOME LOWER 50 DEW POINTS TO MAKE IT INTO KIOWA AND PROWERS COUNTY TOWARDS MORNING. LATEST HRRR LOOKS A BIT OVERLY AGGRESSIVE BRINGING LOW LEVEL MOISTURE BACK AS FAR WESTWARD AS EL PASO AND PUEBLO COUNTIES...AND HAVE GONE WITH A COMPROMISE BETWEEN THE HRRR AND DRIER NAM12 FOR THESE AREAS. HOWEVER...APPEARS KIOWA COUNTY MAY HAVE THE BEST SHOT OF SEEING SOME DENSE FOG FORMATION...THUS PER COORD WITH SURROUNDING OFFICES...HAVE PUT OUT A DENSE FOG ADVISORY FOR THIS AREA. LATER SHIFTS WILL NEED TO MONITOR PROWERS COUNTY AS WELL...BUT MODEL SOUNDINGS ARE NOT AS IMPRESSIVE WITH LOW LEVEL MOISTURE ACROSS THIS ZONE...WITH RUC13 KEEPING RICHER MOISTURE FARTHER EAST AND NORTH. SO WILL LEAVE THIS ZONE OUT FOR NOW AND CONTINUE TO MONITOR. -KT PREV DISCUSSION... /ISSUED 308 PM MDT SAT MAR 24 2012/ SHORT TERM... (TONIGHT AND SUNDAY) AN UPPER LEVEL RIDGE IS FORECAST TO SHIFT EAST INTO THE CENTRAL PLAINS TONIGHT WITH INCREASING SOUTHWESTERLY FLOW EXPECTED ON SUNDAY. CURRENTLY A WEAK SURFACE BOUNDARY HAS BEEN TRACKING SOUTH ACROSS THE PLAINS. THE MAIN INFLUENCE OF THIS FRONT IS A NORTHERLY WIND SHIFT AND A FEW BRIEF GUSTS OF WIND. TEMPERATURES HAVE EXCEEDED OR TIED RECORDS AT COLORADO SPRINGS AND PUEBLO SO FAR THIS AFTERNOON. TONIGHT AND TOMORROW...GIVEN CLEAR SKIES AND DIMINISHING WINDS WILL LEAD TO OVERNIGHT LOWS IN THE 40S ACROSS SOUTHERN COLORADO. MODELS TRYING TO DEVELOP FOG OUT ALONG THE KANSAS BORDER WHERE WEAK SOUTHEASTERLY UPSLOPE FLOW AND DEEPER MOISTURE RESIDE. THINK AREAS UP THE ARKANSAS RIVER VALLEY NEAR THE KANSAS BORDER STAND THE BEST CHANCE AT SEEING FOG FOR TONIGHT. SOUTHWESTERLY FLOW INCREASES TOMORROW WITH THE MAIN CONCERN BEING THE NEAR RED FLAG CONDITIONS FOR PORTIONS OF THE PLAINS. HUMIDITIES WILL BE LOW GIVEN THE DOWNSLOPE SOUTHWESTERLIES AND DRY AIR MIXING DOWN. WINDS LOOK MARGINAL...WITH A FEW AREAS SEEING GUSTS 20 TO 25 KTS DURING THE AFTERNOON. CAUTION IS ADVISED...ESPECIALLY SOUTH OF HIGHWAY 50 AND ALONG THE KANSAS BORDER. OTHERWISE EXPECT WARM TEMPERATURES WITH RECORD HIGHS ONCE AGAIN FOR SOUTHEAST COLORADO. ALSO OF NOTE...MODELS HINTING AT AN ISOLATED THUNDERSTORM OVER THE SOUTHERN SAN JUAN AND SANGRE DE CRISTO RANGES...BUT CURRENTLY THINK THIS WILL ONLY AMOUNT TO CUMULUS BUILD UPS IN THE AFTERNOON GIVEN LACK OF MOISTURE. 88 LONG TERM... (SUNDAY THROUGH FRIDAY) .CRITICAL FIRE WEATHER CONDITIONS EXPECTED ON MONDAY... MAIN CONCERN THIS FCST PD IS FIRE WX CONCERNS ON MONDAY. AS HAS BEEN FCSTD BY THE SIMULATIONS FOR DAYS...IT WILL LIKELY BE VERY WINDY WITH LOW HUMIDITY VALUES OVER THE REGION ON MONDAY. WIDESPREAD WINDS OF 30 TO 45 MPH WILL OCCUR BY AFTERNOON ACROSS THE ENTIRE REGION AS A VIGOROUS SHORT WAVE MOVES TO OUR NORTH DURING PRIME HEATING. LAPSE RATED OF 8.5 TO 9.5C/KM AND 50 KNOT 700 MB WINDS WILL ALLOW FOR VERY GUST WINDS. WITH THE STRONG WINDS...BLOWING DUST WILL BE AN ISSUE ONCE AGAIN DUE TO THE SUSTAINED DROUGHT CONDITIONS. ALTHOUGH BACA COUNTY RECEIVED ALMOST AN INCH OF RAIN THE OTHER DAY...I AM CONFIDENT THAT THIS AREA WILL DRY OUT SIGNIFICANTLY (1 HOUR FUELS...I.E., GRASSES) BY THE TIME MONDAY ROLLS AROUND. THE DRYLINE WILL LIKELY MIX OUT INTO KS RELATIVELY EARLY IN THE DAY...SO I DO NOT ANTICIPATE ANY CONVECTION ALONG THE BORDER ATTM. IN THE MTNS...SHORT WAVE MAY BE CLOSE ENOUGH ALONG WITH STRONG LIFT TO ALLOW FOR SOME SHOWERS ALONG THE CONTDVD...MAINLY OVER THE C MTNS. ONCE THIS TROUGH GOES BY...GENERAL WEAK WSW FLOW ALOFT WILL BE OVER THE REGION THROUGH LATE WEEK. WX DURING THIS PD WILL BE SEASONAL WITH ABOVE NORMAL TEMPS. A WEAK TROUGH AT MID LVLS WILL MOVE ACROSS THE REGION ON FRIDAY. NO SENSIBLE WX WILL LIKELY OCCUR WITH IT. TEMPS WILL COOL A COUPLE OF DEGREES AS COMPARED TO THURSDAY. WE WILL LIKELY NOT SEE ANY PRECIP AT KCOS...KPUB OR KALS THROUGH THE END OF THE MONTH. TO DATE...AT KPUB WE HAVE RECEIVED 0.11 INCHES...OUR NORMAL IS 0.93. AT KCOS...WE HAVE RECEIVED 0.06...THE NORMAL IS 1.00 INCHES. AT KALS WE RECEIVED 0.10...NORMAL IS 0.53. WITHOUT SAYING...WE NEED PRECIP. /34 AVIATION... VFR CONDITIONS AT ALL TERMINALS THROUGH THE NEXT 24 HOURS. 88 && .PUB WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR COZ221-222-226>237. DENSE FOG ADVISORY FROM 2 AM TO 8 AM MDT SUNDAY FOR COZ095-096. && $$ 31/44
AREA FORECAST DISCUSSION
NWS NEW YORK NY
135 AM EDT SUN MAR 25 2012 .SYNOPSIS... SLOW MOVING LOW PRESSURE OVER THE SOUTHERN MID ATLANTIC REGION WILL PASS TO THE SOUTH SUNDAY NIGHT...THEN HEAD NORTHEAST OUT TO SEA AND STRENGTHEN AFTER A COLD FRONT MOVES THROUGH MONDAY MORNING. HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH MONDAY AFTERNOON THROUGH TUESDAY...AND THEN SLIDE EAST TUESDAY NIGHT. LOW PRESSURE AND AN ASSOCIATED FRONTAL SYSTEM WILL MOVE ACROSS FROM WEDNESDAY INTO EARLY THURSDAY...FOLLOWED BY HIGH PRESSURE LATER THURSDAY INTO FRIDAY. A WARM FRONT WILL APPROACH LATE FRIDAY NIGHT INTO SATURDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... RAIN ASSOCIATED WITH THE LOW TO OUR SW IS FINALLY OVERCOMING LOW LEVEL DRY AIR IN THE NYC METRO AREA...SO HAVE ADJUSTED OVERNIGHT POP ACCORDINGLY...WITH ALL AREAS EVENTUALLY GETTING SOME SHOWERS OVERNIGHT. BACK EDGE OF THESE SHOWERS MOVING SLOWLY N FROM SOUTHERN NJ SHOULD REACH THE NYC METRO AREA IN THE PREDAWN HOURS. THE INCOMING 00Z NAM APPEARS TO AGREE WITH THIS ENDING TIME...THOUGH THE 00Z HRRR HINTS THAT ADDITIONAL SHOWERS COULD FILL IN TO THE SW AND SPREAD INTO THE AREA INTO THE EARLY DAYLIGHT HOURS. SOME ELEVATED INSTABILITY PRESENT BUT AT LEVELS TOO LOW TO PRODUCE THUNDER. EARLIER MAV/MET MOS BLEND LOOKED GOOD FOR LOWS. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/... LOW PRESSURE CENTER EMERGES OFF THE MID ATLANTIC COAST AND CONTINUES TO HEAD EAST DURING THE DAY ON SUNDAY. WITH THE ISENTROPIC LIFT EXITING THE EASTERN ZONES IN THE MORNING...THE ONLY OTHER SOURCES OF LIFT WILL BE A WEAK MID LEVEL SHORTWAVE ENTERING DURING THE AFTERNOON HOURS...WITH PERHAPS A LITTLE BIT OF ADDITIONAL SYNOPTIC LIFT SUPPLIED BY AN UPPER JET STREAK. POPS THEREFORE NO HIGHER THAN THE CHANCE CATEGORY ONCE THE MAIN BATCH OF RAIN EXITS TO THE EAST IN THE MORNING. THE AFTERNOON COULD VERY WELL END UP COMPLETELY DRY FOR MOST SPOTS. LEANED A LITTLE MORE TOWARDS THE COOLER NAM MOS FOR HIGHS...BUT THIS STILL YIELDS HIGHS WARMER THAN NORMAL. THE LOW BEGINS TO HEAD NORTHEAST SUNDAY NIGHT...BUT ONLY A SLIGHT CHANCE OF A SHOWER FOR US EARLY IN THE EVENING...ASSOCIATED WITH THE SHORTWAVE. DRY THEN FOR THE REST OF SUNDAY NIGHT. ON MONDAY...WITH THE STORM CENTER HEADING NE FARTHER OUT TO SEA...A COLD FRONT DROPS DOWN FROM THE NORTH EARLY ON. WITH LIMITED MOISTURE DURING ITS PASSAGE...WILL GO WITH A DRY FORECAST. A STRONG MID LEVEL SHORTWAVE FOLLOWS LATE IN THE DAY INTO THE EVENING HOURS...BUT AGAIN NO RAINFALL EXPECTED WITH IT...JUST SOME CU BUILDUP AT BEST. THE PRESSURE GRADIENT WILL TIGHTEN THROUGH THE DAY AS HIGH PRESSURE BUILDS IN FROM THE NORTH...THIS COMBINED WITH STRONG COLD AIR ADVECTION WILL BRING US A BREEZY DAY WITH GUSTY WINDS. HIGH TEMPERATURE FORECAST FOR MONDAY WILL BE A LITTLE TRICKY WITH THE COLD AIR ADVECTION INCREASING AS THE DAY WEARS ON. BUT AT THE SAME TIME...STRONG DOWNSLOPING COULD OFFSET THIS A LITTLE. IT MIGHT NOT BE THE TYPICAL DIURNAL HEATING PATTERN...AND HIGHS COULD BE ACHIEVED NEAR NOONTIME INSTEAD OF MID-LATE AFTERNOON. TOOK A BLEND OF THE NAM/MAV MOS FOR HIGHS...WHICH ENDS UP A LITTLE ABOVE NORMAL FOR THIS TIME OF THE YEAR. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... A DEEP UPPER TROUGH WILL MOVE TO THE EAST MON NIGHT INTO EARLY TUE MORNING...WITH THE AREA CAUGHT BETWEEN INTENSIFYING LOW PRESSURE SE OF NOVA SCOTIA...AND A STRONG HIGH BUILDING S FROM HUDSON BAY. THE TIGHT PRESSURE GRADIENT BETWEEN THE TWO WILL PRODUCE COLD AND BRISK CONDITIONS MON NIGHT INTO EARLY TUE AFTERNOON. SIDED WITH WARMER MAV MOS GUIDANCE VS NAM FOR LOWS MON NIGHT...BUT EVEN SO MON NIGHT WILL BE QUITE COLD...WITH LOWS ABOVE FREEZING ONLY IN NYC...BELOW 30 OUTSIDE THE NYC METRO AREA...AND POSSIBLY CLOSING IN ON 20 IN SOME OF THE INTERIOR VALLEYS...ESPECIALLY IF WINDS DROP OFF VERY LATE AT NIGHT. WIND CHILLS ACROSS THE INTERIOR WILL ALSO DROP INTO THE TEENS LATE MON NIGHT. DESPITE THE COLD OF MON NIGHT...RISING HEIGHTS ALOFT SHOULD ACTUALLY HELP KEEP HIGHS NEAR AVG ON TUE. FULL MIXING OF 875 MB TEMPS NEAR -2C PLUS DOWNSLOPE FLOW WILL RESULT IN HIGHS IN THE LOWER 50S IN NYC AND COASTAL SECTIONS...AND UPPER 40S INLAND. MORE ROBUST WAA SHOULD TAKE PLACE TUE NIGHT-WED IN RETURN S-SW FLOW AS THE HIGH SLIDES TO THE E-SE AND A WARM FRONT APPROACHES...WITH HIGHS REBOUNDING TO THE UPPER 50S/LOWER 60S. EXPECT A CHANCE OF SHOWERS MAINLY WED AFTERNOON/NIGHT AS THIS FRONT MOVES THROUGH AND A COLD FRONT TRAILING FROM LOW PRESSURE PASSING TO THE NORTH APPROACHES...THEN ONLY SLIGHTLY COOLER BUT STILL ABOVE AVG TEMPS ON THU/FRI AS ANOTHER HIGH BUILDS IN...WITH 50S TO NEAR 60. AFTER THIS HIGH MOVES EAST... ANOTHER WARM FRONT WILL APPROACH LATE FRI NIGHT INTO SAT WITH ANOTHER CHANCE OF SHOWERS. NOTE FOR AGRICULTURAL CONCERNS...TEMPS WILL FALL TO AT OR JUST BELOW FREEZING JUST OUTSIDE OF NYC...AND INTO THE 20S OVER THE LOWER HUDSON VALLEY...INTERIOR NE NJ...SOUTHERN CT...AND CENTRAL/EASTERN LONG ISLAND. SUB-FREEZING TEMPS ARE ALSO POSSIBLE TUE NIGHT OUTSIDE OF URBAN CENTERS IF RADIATIONAL COOLING CONDITIONS ARE RIGHT. WINDS WILL BE LIGHT BUT SOME MID LEVEL CLOUDS PASSING THROUGH MAY MITIGATE THIS SOMEWHAT. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... A WARM FRONT REMAINS TO THE SOUTH...WHILE LOW PRESSURE MOVES SLOWLY ACROSS THE MID ATLANTIC REGION. A COLD FRONT GRADUALLY MOVES ACROSS THE REGION THROUGH MONDAY MORNING. SPOTTY LIGHT RAIN WITH MVFR CIGS ACROSS THE TERMINALS THROUGH THIS MORNING. OCNL IFR CIGS ARE POSSIBLE FROM TIME TO TIME BETWEEN 10-14Z...BUT CONFIDENCE IS TOO LOW TO MENTION IN THE TAFS AT THIS TIME. LIGHT E-NE FLOW CONTINUES TODAY...KEEPING LOW LEVEL MOISTURE AND MVFR CIGS ACROSS THE REGION THROUGH MOST OF TODAY. IMPROVEMENT TO VFR...EXCEPT FOR KGON...IS LIKELY LATE IN THE AFTERNOON. MVFR CIGS WILL REMAIN AT KGON...POSSIBLY LOWERING TO IFR AFTER 00Z MONDAY AS ONSHORE FLOW CONTINUES THROUGH TONIGHT. COLD FRONT BEGINS TO MOVE ACROSS THE REGION THIS EVENING... RESULTING IN A SHIFT IN WINDS TO A NW FLOW...HELPING TO DRY THE LOWER LEVELS OF THE ATMOSPHERE OUT. OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY... .TONIGHT...LINGERING MOISTURE AND LIGHT WINDS COULD LEAD TO LOW CLOUDS AND/OR FOG WITH SUB-VFR CONDITIONS LATE...MAINLY AT KHPN/KISP/KBDR/KGON. .MONDAY-TUESDAY...VFR. COLD FRONT MOVES THROUGH MONDAY MORNING... FOLLOWED BY GUSTY NW-N FLOW. DIMINISHING WINDS TUESDAY AFTERNOON. .WEDNESDAY...MVFR CONDITIONS ARE POSSIBLE IN THE AFTERNOON AND AT NIGHT AS LOW PRESSURE AND A WARM FRONT APPROACH. GUSTY SW FLOW IN THE AFTERNOON. .THURSDAY...VFR. GUSTY NW FLOW. && .MARINE... E FLOW AROUND 15 KT WILL PERSIST TONIGHT...AND OCEAN SEAS MAY COME VERY CLOSE TO REACHING 5 FT. ANY GUSTS TO 25 KT AT THE SAME TIME WOULD BE OCCASIONAL. HAVE THEREFORE HELD OFF ON ISSUING SCA. WAVEWATCH APPEARS TO BE TO HIGH GIVEN THE WIND FORECAST AND LACK OF A SIGNIFICANT SWELL LATE TONIGHT INTO SUNDAY NIGHT...AND HAVE KEPT SEAS BELOW 5 FT. WINDS WILL AT LEAST DIMINISH DURING SUNDAY AND SUNDAY EVENING. FOR MON/MON NIGHT...AT LEAST AN SCA WILL LIKELY BE NEEDED BY AFTERNOON...AND POSSIBLY A GALE WARNING ESPECIALLY ON THE OCEAN. WINDS WILL STRENGTHEN AFTER A COLD FRONTAL PASSAGE MON MORNING...WITH A TIGHTENING PRESSURE GRADIENT AND STRONG COLD AIR ADVECTION MOVING IN. WILL CONTINUE TO MENTION THE THREAT OF GALES IN THE HWO. CONDS SHOULD GRADUALLY FALL THROUGH SCA AND THEN BELOW ON TUE. SCA CONDS POSSIBLE ONCE AGAIN ON THE OCEAN WATERS WED AFTERNOON/NIGHT IN STRENGTHENING S-SW FLOW AHEAD OF A COLD FRONT... AND AGAIN THE AFTERNOON/EVENING IN POST-FRONTAL NW FLOW. && .HYDROLOGY... RELATIVELY DRY CONDITIONS WILL CONTINUE...WITH NO SIGNIFICANT QPF OF 1/2 INCH OR MORE EXPECTED FOR THE NEXT 7 DAYS. IN FACT...THE U.S. DROUGHT MONITOR CATEGORIZES SE CT AS BEING IN MODERATE DROUGHT...AND THE REST OF THE REGION AS ABNORMALLY DRY. && .TIDES/COASTAL FLOODING... A PERSISTENT EAST TO NORTHEAST FLOW WILL EXIST TONIGHT INTO SUNDAY MORNING AS MID ATLANTIC LOW PRESSURE TRACKS SOUTH AND THEN EAST OF THE AREA. THERE IS ONLY A LOW POTENTIAL AT BEST FOR MINOR COASTAL FLOODING...AS 1 1/2 TO 2 FT POSITIVE DEPARTURES ARE NEEDED TO REACH THESE THRESHOLDS. BASED ON CURRENT DEPARTURES AND LATEST MODEL GUIDANCE...FLOODING IS NOT EXPECTED TONIGHT OR SUNDAY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...JC NEAR TERM...JC/GOODMAN SHORT TERM...JC LONG TERM...GOODMAN AVIATION...MPS MARINE...JC/GOODMAN HYDROLOGY...JC/GOODMAN TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MIAMI FL
402 AM EDT SUN MAR 25 2012 .DISCUSSION... CUTOFF UPPER LEVEL LOW SPINNING OVER THE SOUTHEAST...WITH SURFACE COLD FRONT MOVING THROUGH NORTH CENTRAL FLORIDA THIS MORNING. SHOWERS AND ISOLATED THUNDERSTORMS WERE ACROSS THE EASTERN GULF MOVING TOWARDS CENTRAL FLORIDA. THE UPPER LEVEL LOW WILL CONTINUE TO SLIDE TO THE EAST TODAY...AND MOVE INTO THE ATLANTIC BY THIS EVENING. WEST TO SOUTHWEST FLOW WILL CONTINUE ACROSS THE REGION AHEAD OF THE FRONT. MODELS CONTINUE TO SHOW DESTABILIZING CONDITIONS THROUGH THE AFTERNOON. 500MB TEMPS ARE AROUND -12C...LOW LEVEL LAPSE RATES ARE STEEP AND EVEN SLIGHT DAYTIME HEATING IS EXPECTED TO BRING TEMPERATURES INTO THE LOW TO MID 80S. THIS SHOULD ALLOW AT LEAST ISOLATED THUNDERSTORMS TO DEVELOP AHEAD OF AND ALONG THE FRONT. SO EXPANDED THE THUNDERSTORM AREA TO MOST OF THE REGION ALONG AND AHEAD OF THE FRONT. HRRR SHOWS SCATTERED SHOWERS AND SOME THUNDERSTORMS DEVELOPING ACROSS THE EASTERN HALF OF THE REGION BY 18Z. THIS FOLLOWS WITH OTHER MODEL SOLUTIONS...SO EXPECT THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE EAST FROM NORTHERN MIAMI-DADE COUNTY NORTHWARD THIS AFTERNOON. MID LEVEL LAPSE RATES ARE NOT IMPRESSIVE...MOIST ADIABATIC ABOVE 700-800MB...SO LEFT MENTION OF HAIL OUT. THE FRONT IS EXPECTED TO MAKE ITS WAY TOWARDS THE LAKE REGION AROUND 18Z WITH PRECIPITATION ENDING THERE BY 21Z. THE FRONT SHOULD MOVE OFF THE FLORIDA PENINSULA AROUND 00Z...WITH ANY LEFTOVER SHOWERS ACROSS THE SOUTH ENDING BY EARLY EVENING. A DRY NORTHWEST FLOW IS EXPECTED BEHIND THE FRONT...WHICH WILL BRING COOLER CONDITIONS TONIGHT TO THE REGION. OVERNIGHT LOWS ARE EXPECTED TO DROP INTO THE 50S NORTHWEST TO THE LOW TO MID 60S ACROSS THE SOUTHEAST ATLANTIC COAST. SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OUT OF CANADA AND TOWARDS THE MID ATLANTIC STATES ON MONDAY...AND WINDS WILL SHIFT FROM THE NORTHWEST TO THE NORTHEAST BY TUESDAY MORNING. MODELS CONTINUE TO SHOW A WEAK INVERTED TROUGH MOVING ACROSS SOUTH FLORIDA ON TUESDAY...BRINGING A MOISTURE AND WIND SURGE TO THE REGION. SO BREEZY CONDITIONS ARE EXPECTED ACROSS SOUTH FLORIDA ON TUESDAY...WITH ISOLATED SHOWERS ACROSS THE EASTERN HALF OF THE REGION. MODELS THEN SHOW DRIER AIR MOVING BACK INTO THE REGION THROUGH THE END OF THE WEEK. HOWEVER...HIGH PRESSURE IS STILL EXPECTED TO BE NORTHEAST OF THE REGION THROUGH WEDNESDAY...SO THERE WILL STILL BE A CHANCE FOR A PASSING LIGHT SHOWER ACROSS THE EAST COAST METRO AREAS. SO LEFT THE 10 POPS WITH MENTION OF PRECIP THROUGH THE DAY ON WEDNESDAY. HIGH PRESSURE WILL WEAKEN AND SHIFT EAST ON THURSDAY AS A SHORTWAVE TROUGH PUSHES INTO THE MID ATLANTIC STATES. SO LIGHT WINDS AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK. TEMPERATURES WILL REMAIN WARM...WITH HIGHS IN THE LOW TO MID 80S AND LOWS AROUND 60 TO AROUND 70. && .AVIATION... FRONTAL BOUNDARY MOVING SLOWLY SOUTHWARD ACROSS THE FLORIDA PENINSULA. SW FLOW EXPECTED AT ALL TERMINALS THROUGH THE PERIOD AS THE BOUNDARY APPROACHES. CURRENT GUIDANCE DID NOT CHANGE MUCH FROM PREVIOUS RUNS THEREFORE...KEPT VCSH AT ALL TERMINALS TO BEGIN AT 25/16Z...ALONG WITH GUSTY WINDS. MOSTLY CLEAR SKIES AND LIGHTER WINDS ARE EXPECTED BY 26/00Z. && .MARINE... SOUTHWEST WINDS ARE EXPECTED AHEAD OF A COLD FRONT TODAY...WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE BOUNDARY. WINDS WILL SHIFT TO THE NORTHWEST ACROSS THE LOCAL WATERS THIS AFTERNOON THROUGH THE EVENING AS THE COLD FRONT MOVES THROUGH. BY LATE MONDAY...WINDS WILL BECOME EASTERLY AGAIN AS HIGH PRESSURE BUILDS ACROSS THE ATLANTIC. CURRENT GUIDANCE STILL SHOWING A WEAK INVERTED TROUGH MOVING INTO THE LOCAL ATLANTIC WATERS ON TUESDAY. THIS WILL INCREASE THE WINDS ACROSS THE ATLANTIC WATERS WITH SCEC AND POSSIBLY A SHORT PERIOD OF SCA CONDITIONS IN WEDNESDAY MORNING. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS TODAY AS A COLD FRONT MOVES THROUGH THE REGION. ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG THE FRONT. RELATIVE HUMIDITY VALUES MAY DROP TO AROUND 35 PERCENT ACROSS A LARGE PORTION OF THE REGION MONDAY AFTERNOON AS DRIER AIR MOVES DOWN THE PENINSULA BEHIND THE FRONT. WINDS SHIFT TO THE EAST MONDAY NIGHT...WITH LOW LEVEL MOISTURE RETURNING TO THE AREA. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 84 63 81 66 / 50 10 0 - FORT LAUDERDALE 85 66 83 68 / 40 20 0 - MIAMI 85 65 83 66 / 40 20 0 - NAPLES 82 64 83 63 / 30 10 0 - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...84/AK AVIATION/RADAR...17/ERA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
139 AM EDT SUN MAR 25 2012 .SYNOPSIS... A STRONG UPPER LEVEL LOW WILL MOVE SOUTHEAST OVER THE NEXT 24 HOURS INTO THE CAROLINAS. THIS SYSTEM WILL CONTINUE TO GIVE THE AREA SCATTERED SHOWERS AND THUNDERSTORMS THROUGH SUNDAY. THE RAIN SHOULD END BY SUNDAY EVENING AS THE LOW PULLS EAST OF THE AREA. MOSTLY DRY AND MILD WEATHER CAN BE EXPECTED THROUGH MUCH OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... THE COLD FRONT WILL CONTINUE MOVING EAST THROUGH THE AREA OVERNIGHT. THIS WILL KEEP SHOWERS MAINLY TO THE EAST BUT A 20 PERCENT CHANCE IS EXPECTED MOST OF THE REGION FOR THE REST OF THE NIGHT EXCEPT MAYBE 10 PERCENT IN THE CSRA. WV IMAGERY SHOWS A DRY SLOT MOVING IN FROM THE WEST. BUT THE NAM AND RUC MODELS SHOW MOISTURE WRAPPING AROUND THE STRONG UPPER LOW BRINGING MOISTURE BACK IN ALTHOUGH MOISTURE IS NOT AS DEEP AS AHEAD OF COLD FRONT. DECIDED GO INCLUDE A 40-60 PERCENT CHANCE OF MAINLY SHOWERS NORTH PART IN THE EARLY MORNING HOURS AND 20 PERCENT ELSEWHERE. AS MENTIONED...WILL HAVE ONLY 10 PERCENT POP CSRA. OTHERWISE...WINDS AND TEMPERATURES LOOK OK THIS MORNING. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/... ALTHOUGH THE FRONT WILL BE EAST OF THE AREA ON SUNDAY...THE MAIN COLD POOL OF AIR ASSOCIATED WITH THE UPPER LOW STILL BE CROSSING THROUGH THE REGION DURING THE DAY. SHOULD HAVE PLENTY OF CLOUD COVER THROUGH THE DAY...WHICH WILL LIMIT TEMPS SLIGHTLY. EVEN SO...DUE TO THE STRENGTH OF THE COLD CORE...CAN NOT RULE OUT SOME SHOWERS AND ISOLATED STORMS THROUGH THE DAY. ONCE THE UPPER LOW PUSHES EAST...RAIN CHANCES WILL DIMINISH. DRYING WILL OCCUR OVERNIGHT SUNDAY INTO MONDAY...WITH DRY CONDITIONS RETURNING THROUGH TUESDAY NIGHT. AS FOR TEMPS...NOT REALLY EXPECTING A SIGNIFICANT COOL DOWN BEHIND THE LOW. TEMPS WILL STILL BE IN THE 70S DURING THE DAY THROUGH THE PERIOD. THE REAL DIFFERENCE WILL BE IN THE DRIER DEWPOINTS THAT WILL SETTLE IN THROUGH TUESDAY. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS WE MOVE INTO WEDNESDAY...ANOTHER STORM SYSTEM WILL PASS CLOSE TO OUR NORTH PUSHING A COLD FRONT INTO THE UPSTATE INTO WEDNESDAY NIGHT. STILL DO NOT EXPECT MUCH IN THE WAY OF PRECIP WITH THIS SYSTEM...SO ONLY LOW POPS WEDNESDAY NIGHT/THURSDAY WITH THAT SYSTEM. OTHERWISE...MOSTLY DRY CONDITIONS INTO NEXT WEEKEND. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... CLOSED LOW OVER NORTHERN GEORGIA WILL MOVE ACROSS NORTHERN SOUTH CAROLINA OVER THE NEXT 24 HOURS. THIS WILL KEEP VFR CEILINGS ACROSS ALL TERMINALS FOR THE FORECAST PERIOD EXCEPT FOR AGS AND DNL WHERE CLEARING IS EXPECTED SUNDAY EVENING AS THE LOW PULLS AWAY TO THE NORTHEAST OF THE STATE. COLD AIR IN THE CENTER OF THE SYSTEM WILL DESTABILIZE THE ATMOSPHERE THIS AFTERNOON GIVING A CHANCE OF SHOWERS AND POSSIBLY THUNDERSTORMS WITH ATTENDANT MVFR/IFR CONDITIONS POSSIBLE. THE CHANCE OF THUNDER IS BEST OVER KCAE...KCUB AND KOGB IN THE BETTER MOISTURE. THERE MAY BE SOME MVFR FOG AT KCAE...KCUB AND KOBG THIS MORNING AS A MID LEVEL DRY AIR PATCH CROSSES THE AREA... ALLOWING SOME RADIATIONAL COOLING PLUS MOISTURE FROM RECENT RAINS. WEST TO NORTHWEST WIND WILL KEEP REDUCE THE CHANCE OF IFR CEILINGS AND VISIBILITY. EXTENDED AVIATION OUTLOOK...UNRESTRICTED FLYING CONDITIONS WILL RETURN MONDAY INTO WEDNESDAY...WHEN THE NEXT STORM SYSTEM APPROACHES THE AREA FROM THE NORTHWEST. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ SYNOPSIS...07 NEAR TERM...07 SHORT TERM... LONG TERM... AVIATION...
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
1252 AM CDT SUN MAR 25 2012 ...UPDATED AVIATION SECTION AND NEAR TERM SECTION... .UPDATE... ISSUED AT 1255 AM CDT SAT MAR 24 2012 LATEST MODELS CONTINUE TO SUGGEST THAT 50 DEGREE DEWPOINTS WILL BE FOUND ACROSS WESTERN KANSAS EARLY THIS MORNING AND WITH TEMPERATURES FALLING TO NEAR 50 DEGREES FOG MAY FORM TOWARDS SUNRISE. THE HRRR AND NAM DEPICT DENSE FOG DEVELOPING ACROSS THE TWO WESTERN ROWS OF COUNTIES BY 08Z WITH A FEW POCKETS OF LOWER VISIBILITIES TO THE EAST OF THIS AREA. A FEW HIGH CLOUDS ARE FORMING ACROSS EASTERN COLORADO AND IF THEY MOVE INTO KANSAS IT MAY HINDER FOG DEVELOPMENT. NEVERTHELESS, I HAVE KEPT THE DENSE FOG ADVISORY AS IS FOR THE TIME BEING. THE REMAINDER OF THE FORECAST IS ON TRACK FOR THE NEAR TERM PERIOD. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 345 PM CDT SAT MAR 24 2012 A GENERAL WARMING TREND IS ANTICIPATED IN THE VERY SHORT TERM FORECAST. TEMPERATURES WARMED INTO THE LOW TO MID 70S THIS AFTERNOON AND WERE HEADED TOWARD THE 80 DEGREE MARK IN THE LATE AFTERNOON. THE AREA WILL REMAIN IN THE WARM SECTOR SOUTH TO SOUTHEAST FLOW AS WEAK CYCLOGENESIS REMAINS FOCUSED DIURNALLY OVER SOUTHEAST COLORADO. SURFACE MOISTURE WILL INCREASE ACROSS THE AREA INCREASING DEW POINTS INTO THE 50S THE NEXT FEW DAYS. THE COMBINATION OF SOUTHEAST UPSLOPE WINDS AND HIGHER LEVEL MOISTURE AIR, ACROSS THE AREA WILL BE FAVORABLE FOR DENSE FOG DEVELOPMENT AS TEMPERATURES FALL OVERNIGHT UNDER A VERY DRY MID AND UPPER LEVEL AIRMASS. THE RUC AND NAM BOTH INDICATE DENSE FOG DEVELOPMENT, AND ARE NOT IN AGREEMENT AT ALL ON THE PLACEMENT. HOWEVER THE MOST FAVORABLE LOCATION FOR WIDESPREAD DENSE FOG DEVELOPMENT WILL BE WHERE THE WINDS GO LIGHT IN THE ZONE OF SURFACE WIND CONVERGENCE PROBABLY AFTER 8Z. DEW POINTS WILL LIKELY MIX OUT TO LOWER VALUES IN THE FAR WESTERN COUNTIES ON SUNDAY. THE NAM INDICATED THE REAL DRYLINE TO BE POSITIONED WELL TO THE SOUTHWEST IN NE NEW MEXICO WHERE IT WANTS TO DEVELOP CONVECTIVE PRECIPITATION IN THE LATE AFTERNOON AS IT IS RETREATING. HAVING SAID THAT, THE SURFACE POSITIVE BUOYANT ENERGY IS A RESPECTABLE 1000-2000 J/KG FROM A DIGHTON TO MEADE CORRIDOR AS MODELED BY THE NAM. HOWEVER, THE ATMOSPHERE ALOFT REMAINS DRY ON SUNDAY. THE WARM NOSE ON THE 21 UTC NAM SOUNDING SUGGESTS PARCELS WOULD NEED TO BE LIFTED FROM ABOVE 800 MB WHICH DOESN`T APPEAR PLAUSIBLE WITH SUCH WEAK SURFACE CONVERGENCE AND DRY AIR. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 256 PM CDT SAT MAR 24 2012 SUNDAY NIGHT WILL SEE AN UPPER LEVEL RIDGE WORK EASTWARD INTO EASTERN KANSAS. AN UPPER LOW PRESSURE SYSTEM OVER SOUTHERN NEVADA WILL ALLOW A SOUTHWEST UPPER FLOW TO DEVELOP ACROSS WESTERN KANSAS MONDAY. A DRY LINE WILL START ADVANCING WEST EARLY IN THE DAY MONDAY, AND SOUTH WINDS WILL BECOME STRONG, ESPECIALLY IN OUR WEST ON THE MOIST SIDE OF THE DRY LINE. FOR NOW, GRIDS WILL HAVE 25-35KTS G40KTS IN MY WESTERN 1/2 OF THE CWA, AND 15-25KTS G30KTS IN THE EASTERN CWA. A WIND ADVISORY WILL LIKELY BE NEEDED FOR MONDAY AFTERNOON, BUT WILL HOLD OFF ONE OR TWO MORE SHIFTS BEFORE ISSUING THE NPW PRODUCT. STORMS MAY FIRE IN THE LATE DAY IN OUR WEST NEAR THE DRY LINE, BUT THE BETTER UPPER LEVEL DYNAMICS ARE TO OUR NORTH. THE 20 POPS SEEM APPROPRIATE FOR THIS SITUATION, UNLESS LATER MODEL RUNS SHOW SOMETHING DIFFERENT. FOR WHAT IT IS WORTH, THE GFS BACKED OFF ON THUNDERSTORMS MONDAY AFTERNOON, KEEPING THE PRECIPITATION FAR TO OUR NORTH. MONDAY NIGHT WILL BE PARTLY TO MOSTLY CLOUDY WITH A WEAK UPPER TROUGH CROSSING JUST TO OUR NORTH. A FAIRLY STRONG COLD FRONT WILL SLIP INTO OUR NORTHWEST SECTIONS AFTER MIDNIGHT AND BE NEAR OUR SOUTHERN BORDER BY TUESDAY MORNING. THEN, THE FRONT APPEARS TO DISSIPATE NEAR THE OKLAHOMA TUESDAY MORNING, BEFORE STARTING TO ADVANCE BACK NORTH AS A WARM FRONT WEDNESDAY. SINCE THAT FRONT IS PLOWING THROUGH DECENT LOW LEVEL MOISTURE, 20 PERCENT POPS WILL START IN THE WEST LATE MONDAY AND TRANSFER TO THE EAST MONDAY NIGHT. SEEMS THERE WILL BE AT LEAST A SMALL CHANCE FOR SEVERE STORMS WITH HAIL MONDAY NIGHT, BUT WITH 20 POPS DO NOT PLAN TO MENTION SEVERE STORMS IN THE GRIDS. WILL UPDATE THE HWO TO AT LEAST MENTION SEVERE STORMS ARE POSSIBLE. NO PLANS IN OUR 3 WESTERN COUNTIES FOR POPS MONDAY NIGHT. MIN TEMPS MON NIGHT WILL DEPEND STRONGLY ON THE COLD FRONT MOVEMENT AND POSITION, AND RANGE FROM THE LOWER 40S IN OUR EXTREME NORTHWEST COUNTIES SUCH AS HAMILTON TO THE LOWER 50S FROM HAYS TO DODGE CITY TO NEAR LIBERAL, AND THE MID 50S IN THE PRATT AND BARBER COUNTY AREAS. ANY PRECIP SHOULD BE EAST OF OUR CWA BY TUESDAY, WITH MAX TEMPS BEHIND THE FRONT 10 TO 15 DEGREES COLDER THAN MONDAY, MAXING IN THE 70 DEGREE RANGE IN SCOTT CITY TO NEAR 77 DEGREES IN MEDICINE LODGE. TUESDAY SHOULD PRODUCE SUNNY SKIES AS WELL. TUESDAY NIGHT WILL BE MOSTLY CLEAR WITH NO PRECIPITATION, AND MINIMUMS IN THE LOWER 40S IN OUR NORTHWEST RANGING TO THE MID 50S IN OUR SOUTHEAST. ON WEDNESDAY, THAT FRONT WILL ADVANCE NORTH AS A WARM FRONT AND MOVE INTO OUR SOUTHERN CWA. SOUTHERN PARTS OF OUR CWA WILL BECOME PARTLY CLOUDY WHILE NORTHERN PARTS OF OUR FORECAST CONTINUING TO BE MOSTLY SUNNY. LATE WEDNESDAY, THERE IS A SLIGHT CHANCE FOR A THUNDERSTORM IN OUR EXTREME SOUTHEAST, DUE TO DAY TIME HEATING AND DEW POINTS NEAR 60F DEGREES. EXPECT PARTLY CLOUDY SKIES WEDNESDAY NIGHT, LOW TEMPS IN THE 50F TO 56F DEGREE RANGE, AND A SLIGHT CHANCE OF STORMS IN OUR EASTERN 2 COUNTIES OF THE CWA. ON THURSDAY, THE DRY LINE WILL COME BACK INTO PLAY, MARCHING EAST ACROSS OUR AREA DURING THE DAY. BY THE TIME OF MAX HEATING, WITH HIGHS EXPECTED IN THE UPPER 70S TO LOWER 80S, A THUNDERSTORM OR TWO WILL BE POSSIBLE NEAR THE DRY LINE. THURSDAY NIGHT WILL CONTINUE TO SEE SLIGHT CHANCES FOR STORMS, WITH THAT CHANCE SPREADING WEST ACROSS ALL OUR CWA BY FRIDAY. AN UPPER WAVE WILL CROSS JUST NORTH OF OUR CWA, AND MAY FIRE OFF A FEW STORMS FRIDAY AND FRIDAY NIGHT. MAX TEMPS EXPECTED FRIDAY ARE IN THE MID 70S, WITH MIN TEMPS FROM 46F TO 54F DEGREES FRIDAY NIGHT, AND MAXIMUM TEMPERATURES ON SATURDAY RANGING IN THE MID TO UPPER 70S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1255 AM CDT SUN MAR 25 2012 HIGH PRESSURE WILL BE FOUND ACROSS EASTERN KANSAS AND LEE TROUGHING WILL BE FOUND ACROSS THE KS/CO BORDER THROUGHOUT THE TAF PERIOD. THIS WILL BRING SOUTH SOUTHEAST WINDS AROUND 10 KNOTS TO THE TAF SITES OVERNIGHT. WITH THIS UPSLOPE FLOW AND DEWPOINTS IN THE 50S SOME LOWER VISIBILITIES MAY FORM ACROSS THE GARDEN CITY AND DODGE CITY TERMINALS. AS FOR NOW I WENT WITH 5SM AT DDC AND AROUND 1SM AT GCK. VISIBILITIES BELOW A MILE ARE POSSIBLE WEST OF GARDEN CITY AND MAY HAVE TO UPDATE TAFS IF THIS MOVES FARTHER EAST THAN ANTICIPATED. ANY FOG THAT DOES DEVELOP SHOULD ERODE BY 14Z. THE PRESSURE GRADIENT WILL TIGHTEN LATE IN THE MORNING AS LEE TROUGHING STRENGTHENS AND THE ATMOSPHERE MIXES. WINDS WILL SHIFT MORE TO THE SOUTH AND INCREASE TO AROUND 20 KNOTS WITH SOME GUSTS OVER 25 KNOTS. VFR CONDITIONS WILL PREVAIL THROUGHOUT THE LATE MORNING AND AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DDC 57 82 52 74 / 0 20 20 0 GCK 56 83 48 73 / 0 20 20 0 EHA 55 85 45 73 / 0 10 10 0 LBL 56 83 48 75 / 0 20 20 0 HYS 57 82 51 73 / 0 10 20 0 P28 57 82 56 76 / 0 10 20 0 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR KSZ030-043>045-061>063-074-075-084-085. && $$ UPDATE...HOVORKA 42 SHORT TERM...RUSSELL LONG TERM....BURKE AVIATION...HOVORKA 42
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1140 PM MDT SAT MAR 24 2012 .UPDATE... ISSUED AT 1137 PM MDT SAT MAR 24 2012 MADE A FEW QUICK UPDATES TO ACCOUNT FOR INCREASING AREA OF HIGH CLOUDS ACROSS NORTHERN CWA AND INCREASE CLOUD COVER IN AREAS WHERE DENSE FOG IS EXPECTED LATER THIS MORNING. THESE PERSISTENT HIGH CLOUDS BRING SOME CONCERN ABOUT FOG POTENTIAL IN THIS AREA...BUT OTHERWISE LIGHT SOUTHEASTERLY FLOW WITH TDS AROUND 50 AND CONFLUENT ZONE CONTINUE TO SUPPORT FOG POTENTIAL LATER. UPDATE ISSUED AT 843 PM MDT SAT MAR 24 2012 JUST COMPLETED AN UPDATE. MAIN CHANGES WERE TO INCREASE COVERAGE OF THE FOG OVER THE ENTIRE AREA AND ISSUED A DENSE FOG ADVISORY FOR EAST CENTRAL COLORADO AND MUCH OF NORTHWEST KANSAS UNTIL 15Z SUNDAY MORNING. 00Z DDC AND LBF SOUNDINGS SHOW LOW LEVEL MOISTURE HAS INCREASED IN VALUE AND DEPTH FROM 24 HOURS AGO. MOST MODEL OUTPUT IS UNDERDOING THE LOW LEVEL MOISTURE. HOWEVER...THE RUC AND HRRR HAVE CAUGHT ONTO THIS HIGHER MOISTURE AND HAVE BEEN CONSISTENT IN KEEPING AND/OR INCREASING NOT ONLY THE COVERAGE OF THE FOG BUT THE EXTENT OF THE DENSE FOG. THE 00Z NAM HAS FINALLY CAUGHT ON AS WELL. ALL THREE MODELS ARE VERY CLOSE IN THEIR DEPICTION OF THE DENSE FOG AREA. SO HAD FAIRLY HIGH CONFIDENCE IN ISSUING THE ADVISORY FOR THE AREA IN QUESTION. OVERNIGHT SHIFT CAN TWEAK THIS FURTHER AS THE NIGHT PROGRESSES. WITH HIGHER DEWPOINTS ALSO RAISED THE MINS ACCORDINGLY...ESPECIALLY IN THE SOUTHERN HALF BASED ON REALITY/LATEST RUC/HRRR. RUC/HRRR WERE DOING WELL ON DEWPOINTS/WINDS AND USED THEM FOR THE UPDATE AS WELL. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 254 PM MDT SAT MAR 24 2012 500 MB RIDGE WILL REMAIN OVER THE FORECAST AREA THROUGH SUNDAY BEFORE IT SHIFTS EAST SUNDAY NIGHT. SURFACE DEWPOINTS WILL BE IN THE 40S MOST AREAS TONIGHT...AND DEW POINT DEPRESSIONS WILL BE LOW AFTER 09Z. WITH LIGHT WINDS AND WEAK SUBSIDENCE...EXPECT PATCHY FOG TO DEVELOP LATE TONIGHT. FOG MAY BE MORE WIDESPREAD/DENSE THAN LAST NIGHT GIVEN THE INCREASE OF LOW LEVEL DEW POINTS...BUT WILL MONITOR THE EVOLUTION OF FOG FORMATION BEFORE HOISTING ANY HIGHLIGHTS. WILL UPDATE THE HAZARDOUS WEATHER OUTLOOK...HOWEVER...FOR FOG POSSIBILITIES. THERMAL RIDGE WILL MOVE ACROSS THE AREA SUNDAY WHICH WILL PRODUCE HIGH TEMPERATURES IN THE LOWER 80S. A DRY LINE WILL DEVELOP OVER EASTERN COLORADO DURING THE AFTERNOON...AND IT WILL PUSH EAST DURING THE AFTERNOON REACHING THE KANSAS BORDER BY 21Z. CONSIDERED INTRODUCING CONVECTION INTO THE FORECAST EAST OF THE DRY LINE AS MIXED LAYER CAPES WILL BE DECENT IN THE MOIST AIR. HODOGRAPHS ALSO SHOW GOOD SHEAR. HOWEVER...WITH THE AMOUNT OF INHIBITION AND LACK OF DECENT LOW TO MID LEVEL SUPPORT...DECIDED AGAINST THUNDERSTORMS. WEST OF THE DRY LINE...EXPECT RELATIVE HUMIDITIES TO DROP TO 15 PERCENT IN EASTERN COLORADO MAINLY ACROSS WESTERN KIT CARSON AND WESTERN CHEYENNE COUNTIES. SURFACE WINDS WILL ONLY BE AROUND 15 MPH...SO WILL NOT MENTION ANY FIRE WEATHER HIGHLIGHTS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 254 PM MDT SAT MAR 24 2012 NUMEROUS CONCERNS FOR FORECAST AREA ON MONDAY INCLUDING POTENTIAL FOR A FEW RECORD HIGHS (SEE CLIMATE SECTION BELOW), STRONG FIRE WEATHER POTENTIAL (SEE FIRE WEATHER SECTION BELOW), AND POTENTIAL FOR CONVECTION DURING THE LATE AFTERNOON AND EVENING HOURS. FAIRLY POTENT SHORTWAVE TROUGH IS PROGGED TO MOVE OUT OF THE GREAT BASIN AND INTO THE WESTERN DAKOTAS DURING THE DAY. A DRYLINE WILL SET UP INITIALLY ALONG THE KS/CO BORDER AND IS PROGGED TO MIX EASTWARD TOWARD THE HIGHWAY 25 CORRIDOR BY MID AFTERNOON. THERE IS SOME DEGREE OF UNCERTAINTY WITH REGARD TO THE EXACT PLACEMENT OF THE DRYLINE AND THIS WILL HAVE AN IMPACT ON THE POTENTIAL FOR CONVECTION AT ANY ONE LOCATION. ADDITIONALLY, STRONGEST FORCING FOR ASCENT WILL RESIDE NORTH OF THE FORECAST AREA SO FEEL CONFIDENT IN KEEPING SLIGHT CHANCE POPS GOING. HAVING SAID THAT...PARAMETERS WOULD FAVOR STRONG/SEVERE CONVECTION SHOULD SOMETHING GET GOING. FEEL BEST SHOT FOR CONVECTION IS FURTHER EAST THAN PREVIOUSLY ADVERTISED SO NUDGED POPS THAT DIRECTION. HAVE ALSO INSERTED BLOWING DUST MENTION FOR LOCATIONS TO THE WEST OF THE DRYLINE. DESPITE RECENT PRECIP...SOIL MOISTURE DEFICITS REMAIN HIGH. ALSO VERY CONCERNED ABOUT BLOWING DUST/SAND ACROSS CENTRAL PORTIONS OF YUMA COUNTY WHERE A VERY LARGE BURN SCAR FROM A FIRE LAST SUNDAY WILL ENHANCED POTENTIAL FOR REDUCED VISIBILITIES. SLIGHTLY COOLER...BUT STILL MUCH ABOVE NORMAL...AIR MOVES INTO THE CENTRAL HIGH PLAINS ON TUESDAY. GIVEN LATEST PROGS...DID BUMP MAX TEMPS UP A FEW DEGREES ACROSS THE AREA. BROAD/FLAT RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS WEDNESDAY WITH A WEAK SHORTWAVE TROUGH PROGGED TO PASS THURSDAY INTO THURSDAY NIGHT. SLIGHT CHANCE POPS ACROSS THE EAST INITIALLY IN MOIST SOUTHEAST FLOW BEFORE SPREADING OVER THE REMAINDER OF THE FORECAST AREA. MUCH ABOVE NORMAL TEMPS WILL CONTINUE INTO THE WEEKEND WITH TEMPS REMAINING IN THE 70S TO NEAR 80. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1057 PM MDT SAT MAR 24 2012 FOG AND STRATUS ARE EXPECTED TO DEVELOP ROUGHLY IN THE 08Z TO 11Z TIME FRAME. CONDITIONS AT KGLD ARE EXPECTED TO DROP INTO THE IFR TO LIFR CATEGORY AND LAST UNTIL NEAR 15Z WHEN THE FOG IS GONE AND THE CEILINGS RISE INTO THE MVFR CATEGORY. CONDITIONS SHOULD BE VFR BY 18Z AS THE WINDS BECOME GUSTY AT 18Z. FOR KMCK THE MAIN PROBLEM WILL BE FOG REDUCING VISIBILITIES INTO THE MVFR CATEGORY WITH NO CEILINGS EXPECTED AT THIS TIME. CONDITIONS WILL IMPROVE EARLIER THERE THAN AT KGLD AS WINDS ALSO BECOME STRONGER AND GUSTY FROM THE SOUTH. && .FIRE WEATHER... ISSUED AT 254 PM MDT SAT MAR 24 2012 BORDERLINE FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS EASTERN COLORADO ON SUNDAY. HOWEVER...WIND SPEEDS ARE EXPECTED TO REMAIN BELOW CRITERIA NEEDED FOR ISSUANCE OF A RED FLAG WARNING. A MORE SUBSTANTIAL CRITICAL FIRE WEATHER DAY APPEARS LIKELY ALONG AND WEST OF HIGHWAY 25 ON MONDAY TO THE WEST OF A FAIRLY STOUT DRYLINE. GIVEN HIGH CONFIDENCE...WILL GO AHEAD AND ISSUE A FIRE WEATHER WATCH FOR THESE LOCATIONS. RECENT PRECIP AND THE RESULTANT GREEN UP MAY HELP MITIGATE THE THREAT BUT SUBSTANTIAL DRY FUELS REMAIN ACROSS THE TRI-STATE REGION. RH VALUES WILL BE BELOW 20 PERCENT AGAIN ON TUESDAY...WEDNESDAY ...AND THURSDAY ACROSS WESTERN PORTIONS OF THE AREA BUT CURRENT INDICATIONS WOULD SHOW THE WIND SPEEDS SHOULD REMAIN LIGHT AT AROUND 10 MPH OR LESS. && .CLIMATE... ISSUED AT 254 PM MDT SAT MAR 24 2012 POTENTIAL CONTINUES TO EXIST FOR A FEW RECORD HIGHS TO FALL ON MONDAY BUT THE BIGGER STORY BY THIS TIME NEXT WEEKEND WILL BE THE FACT THAT A FEW LOCATIONS WILL HAVE SET AN ALL-TIME RECORD FOR THE WARMEST AVERAGE TEMPERATURE. CURRENT RECORDS ARE AS FOLLOWS: GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.0 BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 46.7 MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.5 HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 50.8 WITH FORECASTED TEMPS...CONFIDENCE IS HIGH THAT AT LEAST GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON RECORD. IT REMAINS TO BE SEEN IF HILL CITY WILL BREAK THE RECORD AS WELL. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR COZ252>254. DENSE FOG ADVISORY UNTIL 9 AM MDT SUNDAY FOR COZ090>092. KS...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR KSZ001-002-013-014-027-028-041-042. DENSE FOG ADVISORY UNTIL 9 AM MDT /10 AM CDT/ SUNDAY FOR KSZ013>016-027>029-041-042. NE...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR NEZ079-080. && $$ UPDATE...JRM SHORT TERM...MENTZER LONG TERM....FOLTZ AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1102 PM MDT SAT MAR 24 2012 .UPDATE... ISSUED AT 843 PM MDT SAT MAR 24 2012 JUST COMPLETED AN UPDATE. MAIN CHANGES WERE TO INCREASE COVERAGE OF THE FOG OVER THE ENTIRE AREA AND ISSUED A DENSE FOG ADVISORY FOR EAST CENTRAL COLORADO AND MUCH OF NORTHWEST KANSAS UNTIL 15Z SUNDAY MORNING. 00Z DDC AND LBF SOUNDINGS SHOW LOW LEVEL MOISTURE HAS INCREASED IN VALUE AND DEPTH FROM 24 HOURS AGO. MOST MODEL OUTPUT IS UNDERDOING THE LOW LEVEL MOISTURE. HOWEVER...THE RUC AND HRRR HAVE CAUGHT ONTO THIS HIGHER MOISTURE AND HAVE BEEN CONSISTENT IN KEEPING AND/OR INCREASING NOT ONLY THE COVERAGE OF THE FOG BUT THE EXTENT OF THE DENSE FOG. THE 00Z NAM HAS FINALLY CAUGHT ON AS WELL. ALL THREE MODELS ARE VERY CLOSE IN THEIR DEPICTION OF THE DENSE FOG AREA. SO HAD FAIRLY HIGH CONFIDENCE IN ISSUING THE ADVISORY FOR THE AREA IN QUESTION. OVERNIGHT SHIFT CAN TWEAK THIS FURTHER AS THE NIGHT PROGRESSES. WITH HIGHER DEWPOINTS ALSO RAISED THE MINS ACCORDINGLY...ESPECIALLY IN THE SOUTHERN HALF BASED ON REALITY/LATEST RUC/HRRR. RUC/HRRR WERE DOING WELL ON DEWPOINTS/WINDS AND USED THEM FOR THE UPDATE AS WELL. UPDATE ISSUED AT 549 PM MDT SAT MAR 24 2012 DID AN EARLY UPDATE. CURRENT DEWPOINTS OVER THE FORECAST AREA AND UPSTREAM ARE HIGHER THAN WHAT MOST MODEL OUTPUT INDICATES. THE HRRR FOOLLOWED BY THE RUC ARE CATCHING THE DEWPOINTS THE BEST AND INCREASE THE DEWPOINTS OVER THE ENTIRE AREA THROUGH THE NIGHT. USED THE HRRR FOR THE UPDATE. LATEST RUC AND NAM OUTPUT IS NOT ONLY INCREASING THE AREAL COVERAGE OF THE FOG BUT ALSO IS DECREASING THE VISIBILITY. SO INCREASED THE COVERAGE AND ALSO ADDED DENSE WORDING TO THE GRIDS. WILL CONTINUE TO WATCH THE TRENDS ON THE OBSERVATIONS PLUS WAIT FOR THE 00Z SOUNDINGS TO SEE IF A DENSE FOG ADVISORY WILL BE NEEDED BUT CHANCES OF THIS ARE ON THE INCREASE. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 254 PM MDT SAT MAR 24 2012 500 MB RIDGE WILL REMAIN OVER THE FORECAST AREA THROUGH SUNDAY BEFORE IT SHIFTS EAST SUNDAY NIGHT. SURFACE DEWPOINTS WILL BE IN THE 40S MOST AREAS TONIGHT...AND DEW POINT DEPRESSIONS WILL BE LOW AFTER 09Z. WITH LIGHT WINDS AND WEAK SUBSIDENCE...EXPECT PATCHY FOG TO DEVELOP LATE TONIGHT. FOG MAY BE MORE WIDESPREAD/DENSE THAN LAST NIGHT GIVEN THE INCREASE OF LOW LEVEL DEW POINTS...BUT WILL MONITOR THE EVOLUTION OF FOG FORMATION BEFORE HOISTING ANY HIGHLIGHTS. WILL UPDATE THE HAZARDOUS WEATHER OUTLOOK...HOWEVER...FOR FOG POSSIBILITIES. THERMAL RIDGE WILL MOVE ACROSS THE AREA SUNDAY WHICH WILL PRODUCE HIGH TEMPERATURES IN THE LOWER 80S. A DRY LINE WILL DEVELOP OVER EASTERN COLORADO DURING THE AFTERNOON...AND IT WILL PUSH EAST DURING THE AFTERNOON REACHING THE KANSAS BORDER BY 21Z. CONSIDERED INTRODUCING CONVECTION INTO THE FORECAST EAST OF THE DRY LINE AS MIXED LAYER CAPES WILL BE DECENT IN THE MOIST AIR. HODOGRAPHS ALSO SHOW GOOD SHEAR. HOWEVER...WITH THE AMOUNT OF INHIBITION AND LACK OF DECENT LOW TO MID LEVEL SUPPORT...DECIDED AGAINST THUNDERSTORMS. WEST OF THE DRY LINE...EXPECT RELATIVE HUMIDITIES TO DROP TO 15 PERCENT IN EASTERN COLORADO MAINLY ACROSS WESTERN KIT CARSON AND WESTERN CHEYENNE COUNTIES. SURFACE WINDS WILL ONLY BE AROUND 15 MPH...SO WILL NOT MENTION ANY FIRE WEATHER HIGHLIGHTS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 254 PM MDT SAT MAR 24 2012 NUMEROUS CONCERNS FOR FORECAST AREA ON MONDAY INCLUDING POTENTIAL FOR A FEW RECORD HIGHS (SEE CLIMATE SECTION BELOW), STRONG FIRE WEATHER POTENTIAL (SEE FIRE WEATHER SECTION BELOW), AND POTENTIAL FOR CONVECTION DURING THE LATE AFTERNOON AND EVENING HOURS. FAIRLY POTENT SHORTWAVE TROUGH IS PROGGED TO MOVE OUT OF THE GREAT BASIN AND INTO THE WESTERN DAKOTAS DURING THE DAY. A DRYLINE WILL SET UP INITIALLY ALONG THE KS/CO BORDER AND IS PROGGED TO MIX EASTWARD TOWARD THE HIGHWAY 25 CORRIDOR BY MID AFTERNOON. THERE IS SOME DEGREE OF UNCERTAINTY WITH REGARD TO THE EXACT PLACEMENT OF THE DRYLINE AND THIS WILL HAVE AN IMPACT ON THE POTENTIAL FOR CONVECTION AT ANY ONE LOCATION. ADDITIONALLY, STRONGEST FORCING FOR ASCENT WILL RESIDE NORTH OF THE FORECAST AREA SO FEEL CONFIDENT IN KEEPING SLIGHT CHANCE POPS GOING. HAVING SAID THAT...PARAMETERS WOULD FAVOR STRONG/SEVERE CONVECTION SHOULD SOMETHING GET GOING. FEEL BEST SHOT FOR CONVECTION IS FURTHER EAST THAN PREVIOUSLY ADVERTISED SO NUDGED POPS THAT DIRECTION. HAVE ALSO INSERTED BLOWING DUST MENTION FOR LOCATIONS TO THE WEST OF THE DRYLINE. DESPITE RECENT PRECIP...SOIL MOISTURE DEFICITS REMAIN HIGH. ALSO VERY CONCERNED ABOUT BLOWING DUST/SAND ACROSS CENTRAL PORTIONS OF YUMA COUNTY WHERE A VERY LARGE BURN SCAR FROM A FIRE LAST SUNDAY WILL ENHANCED POTENTIAL FOR REDUCED VISIBILITIES. SLIGHTLY COOLER...BUT STILL MUCH ABOVE NORMAL...AIR MOVES INTO THE CENTRAL HIGH PLAINS ON TUESDAY. GIVEN LATEST PROGS...DID BUMP MAX TEMPS UP A FEW DEGREES ACROSS THE AREA. BROAD/FLAT RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS WEDNESDAY WITH A WEAK SHORTWAVE TROUGH PROGGED TO PASS THURSDAY INTO THURSDAY NIGHT. SLIGHT CHANCE POPS ACROSS THE EAST INITIALLY IN MOIST SOUTHEAST FLOW BEFORE SPREADING OVER THE REMAINDER OF THE FORECAST AREA. MUCH ABOVE NORMAL TEMPS WILL CONTINUE INTO THE WEEKEND WITH TEMPS REMAINING IN THE 70S TO NEAR 80. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1057 PM MDT SAT MAR 24 2012 FOG AND STRATUS ARE EXPECTED TO DEVELOP ROUGHLY IN THE 08Z TO 11Z TIME FRAME. CONDITIONS AT KGLD ARE EXPECTED TO DROP INTO THE IFR TO LIFR CATEGORY AND LAST UNTIL NEAR 15Z WHEN THE FOG IS GONE AND THE CEILINGS RISE INTO THE MVFR CATEGORY. CONDITIONS SHOULD BE VFR BY 18Z AS THE WINDS BECOME GUSTY AT 18Z. FOR KMCK THE MAIN PROBLEM WILL BE FOG REDUCING VISIBILITIES INTO THE MVFR CATEGORY WITH NO CEILINGS EXPECTED AT THIS TIME. CONDITIONS WILL IMPROVE EARLIER THERE THAN AT KGLD AS WINDS ALSO BECOME STRONGER AND GUSTY FROM THE SOUTH. && .FIRE WEATHER... ISSUED AT 254 PM MDT SAT MAR 24 2012 BORDERLINE FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS EASTERN COLORADO ON SUNDAY. HOWEVER...WIND SPEEDS ARE EXPECTED TO REMAIN BELOW CRITERIA NEEDED FOR ISSUANCE OF A RED FLAG WARNING. A MORE SUBSTANTIAL CRITICAL FIRE WEATHER DAY APPEARS LIKELY ALONG AND WEST OF HIGHWAY 25 ON MONDAY TO THE WEST OF A FAIRLY STOUT DRYLINE. GIVEN HIGH CONFIDENCE...WILL GO AHEAD AND ISSUE A FIRE WEATHER WATCH FOR THESE LOCATIONS. RECENT PRECIP AND THE RESULTANT GREEN UP MAY HELP MITIGATE THE THREAT BUT SUBSTANTIAL DRY FUELS REMAIN ACROSS THE TRI-STATE REGION. RH VALUES WILL BE BELOW 20 PERCENT AGAIN ON TUESDAY...WEDNESDAY ...AND THURSDAY ACROSS WESTERN PORTIONS OF THE AREA BUT CURRENT INDICATIONS WOULD SHOW THE WIND SPEEDS SHOULD REMAIN LIGHT AT AROUND 10 MPH OR LESS. && .CLIMATE... ISSUED AT 254 PM MDT SAT MAR 24 2012 POTENTIAL CONTINUES TO EXIST FOR A FEW RECORD HIGHS TO FALL ON MONDAY BUT THE BIGGER STORY BY THIS TIME NEXT WEEKEND WILL BE THE FACT THAT A FEW LOCATIONS WILL HAVE SET AN ALL-TIME RECORD FOR THE WARMEST AVERAGE TEMPERATURE. CURRENT RECORDS ARE AS FOLLOWS: GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.0 BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 46.7 MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.5 HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 50.8 WITH FORECASTED TEMPS...CONFIDENCE IS HIGH THAT AT LEAST GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON RECORD. IT REMAINS TO BE SEEN IF HILL CITY WILL BREAK THE RECORD AS WELL. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR COZ252>254. DENSE FOG ADVISORY UNTIL 9 AM MDT SUNDAY FOR COZ090>092. KS...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR KSZ001-002-013-014-027-028-041-042. DENSE FOG ADVISORY UNTIL 9 AM MDT /10 AM CDT/ SUNDAY FOR KSZ013>016-027>029-041-042. NE...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR NEZ079-080. && $$ UPDATE...BULLER SHORT TERM...MENTZER LONG TERM....FOLTZ AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
110 AM EDT SUN MAR 25 2012 .Update... Issued at 1213 AM EDT Mar 25 2012 A quick update this evening to slide precipitation chances to the west just a bit, skirting our extreme western fringes of the CWA. Latest HRRR models continue to handle light showers almost perfectly so have relied heavily on this data for latest sky and POP trends. Also of note, temperatures are dropping off nicely where sky cover is not (mainly eastern CWA). Therefore have lowered low temperatures in these locations. Updated products already out. Update issued at 753 PM EDT Mar 24 2012 Main change with this update was to translate the scattered showers currently in central Indiana down into western sections of the LMK CWA after dark. Adjusted cloud cover accordingly as well. .Short Term (Tonight through Sunday night)... Issued at 305 PM EDT Sat Mar 24 2012 Upper low currently centered over west-central Kentucky continues to slide southeast. The latest satellite imagery indicates the low is starting to pick up the pace as a vort max currently rounds the base. While this low is in the vicinity of our area, expect scattered showers and thunderstorms. Latest radar data illustrates convection is starting to develop across portions of central Kentucky. The best areal coverage for the remainder of the afternoon will be across our south and southeastern forecast area. The low will move over the Lake Cumberland region by the early evening hours, which will shift the greatest precip chances eastward. Any storm that develops this afternoon will be capable of heavy rainfall and small hail. Will likely see a break in shower/storm activity tonight, before deeper moisture wrapping around the broad upper low moves back into the eastern CWA. This will provide isolated-scattered shower chances mainly along the I-75 corridor during the day Sunday. The best chances appear to be during the late morning and early afternoon hours, aided by diurnal heating. Upper level ridging and associated subsidence will then work into the eastern CWA, cutting off shower activity by Sunday evening. This will be the start of a dry period for the entire region. Temperatures made it into the upper 50s and low 60s this afternoon, before the cloud cover increased and slowed the warming trend. Still expect some cloud cover overnight, with low temperatures ranging from the mid 40s to low 50s. Could see some patchy fog in the morning if clouds clear enough, particularly where rain will fall this afternoon. High temperatures Sunday will get into the upper 60s across the Bluegrass region, with lower 70s expected elsewhere. Temperatures Sunday night will be similar to tonight, with perhaps some locations running a few degrees cooler with less cloud cover anticipated. .Long Term (Monday through Saturday)... Updated at 246 PM EDT Mar 24 2012 Monday-Tuesday... Upper-level ridging will move into the region from the west to start the work week off. Low pressure will develop over the northern Rockies on Monday, moving eastward across the Upper Plains into Tuesday. With ridging over us, however, we will remain dry with still above normal temps Mon-Tues. Our far northeastern counties may see some northwest flow cloudiness (perhaps the reason for the cooler temps from the NAM), so will trend temps down over those areas for Monday. Ridge will be centered overhead Tuesday so no large temp gradient expected. Highs Monday should range from the upper 60s northeast to the low-mid 70s southwest. With strong warm air advection on Tuesday, went above guidance for highs in the low 70s northeast to the upper 70s southwest. Our coolest night of recent should be Monday night under sfc high pressure. Temps should drop to the upper 30s/around 40 northeast to the mid 40s south. Tuesday night-Thursday night... By Tuesday night, the cold front from the low pressure over the Upper Midwest will drop across the mid-Mississippi Valley region and approach our CWA towards dawn Wednesday. This should bring a quick shot of showers and thunderstorms to the area mainly Wednesday and Wednesday night as the front sweeps across the CWA to the south-southeast. By Thursday morning, this boundary should be just south of the CWA, so have opted to keep Thursday-Thursday night dry for now, though it is possible a shower or two could squeak north of the TN border during the day Thursday. Although it`s still far out, progged soundings for Wednesday show the possibility of severe storms along the front as it passes through. Looks like unidirectional shear and possibly 1000 J/kg of CAPE may combine to form a strong line of thunderstorms, not overly organized, at least at this time. Best chance for this should be around the Ohio River Wed morn, shifting toward central/south-central KY by Wednesday evening. With the front laying out Wednesday night, threat would likely transition to a heavy rain event, but brief, generally speaking. May mention strong storms in HWO. Have precip ending Wed night from north to south. For highs Wednesday, we should be close to 80 in some spots given the warm start to the day (near 60 degrees). However, behind the front, temps will drop into the low 50s Wed night, and climb into the upper 60s/low 70s for Thursday. Friday on... Differences in the long term do not really arise until Friday as the Euro keeps a hold of the ridge overhead, whereas the GFS flattens it out more and brings a series of shortwaves across the region. Looks like the extended model guidance though as trended upwards as far as POPs are concerned, so will at least keep a slight chance for POPs in on Friday/Friday night as previous forecast did. Will increase POPs to high chance/low likely for Saturday as timing of one upper wave in particular is caught by the GFS and Euro. Trended temps down as a result with upper 60s north to low 70s south for Saturday. && .Aviation (06Z TAF Issuance)... Updated at 111 AM EDT Mar 25 2012 Expecting VFR conditions to prevail at the TAF sites through the forecast period, with the exception of a brief MVFR period of BR at LEX early this morning. Center of the upper low that has plagued the area for several days is now moving into the Carolinas with a few light rain showers still rotating from north to south along west central Kentucky. These showers are expected to slide just west of the BWG terminal and would likely not cause any category drops anyway. Further east, mid level ceilings will likely hold off at LEX the longest and will provide the opportunity for a brief BR scenario between 4 and 7 am EDT. Expect scattered to broken cu/stratocu around 2500-3500 feet by mid to late morning with northwest winds between 5 and 10 mph. Best chance for a stray shower would be at LEX but will leave out of forecast for now. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. $$ Update...........13/BJS Short Term.......MJP Long Term........AL Aviation.........BJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1211 AM EDT SUN MAR 25 2012 .Update... Issued at 1213 AM EDT Mar 25 2012 A quick update this evening to slide precipitation chances to the west just a bit, skirting our extreme western fringes of the CWA. Latest HRRR models continue to handle light showers almost perfectly so have relied heavily on this data for latest sky and POP trends. Also of note, temperatures are dropping off nicely where sky cover is not (mainly eastern CWA). Therefore have lowered low temperatures in these locations. Updated products already out. Update issued at 753 PM EDT Mar 24 2012 Main change with this update was to translate the scattered showers currently in central Indiana down into western sections of the LMK CWA after dark. Adjusted cloud cover accordingly as well. .Short Term (Tonight through Sunday night)... Issued at 305 PM EDT Sat Mar 24 2012 Upper low currently centered over west-central Kentucky continues to slide southeast. The latest satellite imagery indicates the low is starting to pick up the pace as a vort max currently rounds the base. While this low is in the vicinity of our area, expect scattered showers and thunderstorms. Latest radar data illustrates convection is starting to develop across portions of central Kentucky. The best areal coverage for the remainder of the afternoon will be across our south and southeastern forecast area. The low will move over the Lake Cumberland region by the early evening hours, which will shift the greatest precip chances eastward. Any storm that develops this afternoon will be capable of heavy rainfall and small hail. Will likely see a break in shower/storm activity tonight, before deeper moisture wrapping around the broad upper low moves back into the eastern CWA. This will provide isolated-scattered shower chances mainly along the I-75 corridor during the day Sunday. The best chances appear to be during the late morning and early afternoon hours, aided by diurnal heating. Upper level ridging and associated subsidence will then work into the eastern CWA, cutting off shower activity by Sunday evening. This will be the start of a dry period for the entire region. Temperatures made it into the upper 50s and low 60s this afternoon, before the cloud cover increased and slowed the warming trend. Still expect some cloud cover overnight, with low temperatures ranging from the mid 40s to low 50s. Could see some patchy fog in the morning if clouds clear enough, particularly where rain will fall this afternoon. High temperatures Sunday will get into the upper 60s across the Bluegrass region, with lower 70s expected elsewhere. Temperatures Sunday night will be similar to tonight, with perhaps some locations running a few degrees cooler with less cloud cover anticipated. .Long Term (Monday through Saturday)... Updated at 246 PM EDT Mar 24 2012 Monday-Tuesday... Upper-level ridging will move into the region from the west to start the work week off. Low pressure will develop over the northern Rockies on Monday, moving eastward across the Upper Plains into Tuesday. With ridging over us, however, we will remain dry with still above normal temps Mon-Tues. Our far northeastern counties may see some northwest flow cloudiness (perhaps the reason for the cooler temps from the NAM), so will trend temps down over those areas for Monday. Ridge will be centered overhead Tuesday so no large temp gradient expected. Highs Monday should range from the upper 60s northeast to the low-mid 70s southwest. With strong warm air advection on Tuesday, went above guidance for highs in the low 70s northeast to the upper 70s southwest. Our coolest night of recent should be Monday night under sfc high pressure. Temps should drop to the upper 30s/around 40 northeast to the mid 40s south. Tuesday night-Thursday night... By Tuesday night, the cold front from the low pressure over the Upper Midwest will drop across the mid-Mississippi Valley region and approach our CWA towards dawn Wednesday. This should bring a quick shot of showers and thunderstorms to the area mainly Wednesday and Wednesday night as the front sweeps across the CWA to the south-southeast. By Thursday morning, this boundary should be just south of the CWA, so have opted to keep Thursday-Thursday night dry for now, though it is possible a shower or two could squeak north of the TN border during the day Thursday. Although it`s still far out, progged soundings for Wednesday show the possibility of severe storms along the front as it passes through. Looks like unidirectional shear and possibly 1000 J/kg of CAPE may combine to form a strong line of thunderstorms, not overly organized, at least at this time. Best chance for this should be around the Ohio River Wed morn, shifting toward central/south-central KY by Wednesday evening. With the front laying out Wednesday night, threat would likely transition to a heavy rain event, but brief, generally speaking. May mention strong storms in HWO. Have precip ending Wed night from north to south. For highs Wednesday, we should be close to 80 in some spots given the warm start to the day (near 60 degrees). However, behind the front, temps will drop into the low 50s Wed night, and climb into the upper 60s/low 70s for Thursday. Friday on... Differences in the long term do not really arise until Friday as the Euro keeps a hold of the ridge overhead, whereas the GFS flattens it out more and brings a series of shortwaves across the region. Looks like the extended model guidance though as trended upwards as far as POPs are concerned, so will at least keep a slight chance for POPs in on Friday/Friday night as previous forecast did. Will increase POPs to high chance/low likely for Saturday as timing of one upper wave in particular is caught by the GFS and Euro. Trended temps down as a result with upper 60s north to low 70s south for Saturday. && .Aviation (00Z TAF Issuance)... Updated at 653 PM EDT Mar 24 2012 A big upper low centered over Tennessee and Kentucky today will continue to push to the east, moving off the North Carolina coast Sunday afternoon. Tonight winds will be nearly calm with scattered VFR clouds. The HRRR has been advertising a patch of rain developing over central Indiana this afternoon and sliding south tonight, affecting BWG during the pre-dawn hours. The IND radar matches up pretty well with the model projection, so will trust the model and include VCSH at BWG between 05Z and 10Z. Also, some MVFR vsby will be possible at BWG with light winds and dew point depressions dropping to about zero. SDF could see a stray shower from the Indiana activity tonight, but even if they do it would be of minimal impact to aviation so will not include it in the TAF. LEX should be precipitation free overnight. On Sunday some afternoon showers could percolate over the Blue Grass INVOF LEX, but for the most part it should be an uneventful day with low-end VFR stratocu cigs and northwest breezes of 5 to 10 knots. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. $$ UpdateS..........13/BJS Short Term.......MJP Long Term........AL Aviation.........13
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1219 AM CDT SUN MAR 25 2012 .UPDATE... UPDATED FOR THE 06Z AVIATION DISCUSSION BELOW. .DISCUSSION... SEVERAL FEATURES OF INTEREST WILL IMPACT THE REGION OVER THE COMING WEEK... ALTHOUGH AT THIS POINT NO PARTICULARLY SIGNIFICANT WEATHER APPEARS LIKELY. IN THE BIG PICTURE... THE LARGE SCALE UPPER FLOW WILL BECOME LESS AMPLIFIED AND HENCE MORE PROGRESSIVE AND SLIGHTLY MORE SEASONABLE IN OUR NECK OF THE WOODS. THIS MEANS THAT INSTEAD OF SEEING TEMPERATURES OF 20-30 DEGREES ABOVE NORMAL... THEY MAY BE MORE ON THE ORDER OF 10-15 DEGREES ABOVE NORMAL FOR A GOOD PART OF THE UPCOMING WEEK. ONE MAJOR CONCERN COULD BE THE POTENTIAL FOR FREEZING TEMPERATURES IN THE UPCOMING WEEK... SINCE SOME OF THE CALENDAR-DEFICIENT PLANTS HAVE DECIDED IT/S ALREADY TIME TO START GROWING. IT DOESN/T APPEAR AS THOUGH ANY WIDESPREAD FREEZING TEMPERATURES WILL OCCUR THROUGH THE UPCOMING WEEK... BUT PORTIONS OF THE AREA COULD SEE READINGS DIP NEAR OR BELOW FREEZING ON A COUPLE OF MORNINGS. THE GFS AND ECMWF ARE IN DECENT AGREEMENT THROUGH MOST OF THE WEEK... SO GENERALLY FOLLOWED A BLEND OF THEIR GUIDANCE... INCREASINGLY BLENDING IT WITH THE PREVIOUS FORECAST IN THE LATER PERIODS. VISIBLE IMAGERY SHOWS THIS MORNING/S LOW CLOUDS AND FOG HAVE FINALLY BURNED OFF OVER MOST OF THE AREA. TEMPERATURES ARE RESPONDING QUICKLY TO THE SUNSHINE... WITH READINGS CLIMBING THROUGH THE 60S TO AROUND 70. SHOULD CONTINUE TO SEE READINGS WORK UPWARD THE NEXT COUPLE OF HOURS... THEN THINGS WILL COOL OFF BOTH IN RESPONSE TO DARKNESS AND THE COLD FRONT MARCHING SOUTHEAST THROUGH THE AREA. THE FRONT CURRENTLY STRETCHES FROM NEAR INTERNATIONAL FALLS SOUTHWEST INTO EASTERN SOUTH DAKOTA. TEMPERATURES DROP OFF BEHIND THE FRONT... WITH A BIG DROP IN DEWPOINTS NOTED AS WELL. A FEW SHRA COULD DEVELOP IN NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN AS THE FRONT MOVES THROUGH THIS AFTERNOON AND EVENING... BUT AT THIS POINT IT LOOKS LIKE ANY OF THAT ACTIVITY SHOULD STAY NORTH OF OUR AREA. THE HRRR AND LOCAL 4KM WRF-ARW DO MANAGE TO PRODUCE SOME LIGHT SHRA INTO THE NORTHEAST PART OF OUR AREA... BUT AT THIS POINT WOULD RATHER SEE MORE GOING ON IN THE REAL WORLD TO INCLUDE A MENTION. AS MENTIONED... THE FRONT WILL SLIDE THROUGH TONIGHT... WITH RIDGING AND COOLER/DRIER AIR ARRIVING FOR OVERNIGHT THROUGH THE DAY ON SUNDAY. BUT... GIVEN THE MORE PROGRESSIVE FLOW... THIS CHANGE WILL BE SHORT-LIVED... WITH RETURN FLOW SETTING UP QUICKLY SUNDAY NIGHT. ISENTROPIC LIFT SUNDAY NIGHT INTO MONDAY IS IMPRESSIVE AS THE ELEVATED WARM FRONT LIFTS BACK NORTHEAST ACROSS THE AREA. IN ADDITION TO THE ISENTROPIC LIFT... FAIRLY SUBSTANTIAL LOW-MID LEVEL FRONTOGENESIS IS PROGGED FROM LATE SUNDAY NIGHT THROUGH THE DAY ON MONDAY AS THE BOUNDARY SLOWLY LIFTS NORTHEAST ACROSS THE AREA. A LOOK AT ELEVATED INSTABILITY... PER 850-500MB DIFFERENTIAL THETA-E VALUES... SHOWS SOME POTENTIAL FOR THUNDER CREEPING IN FROM WEST TO EAST LATE SUNDAY NIGHT INTO MONDAY NIGHT... WITH A CHANCE FOR SOME THUNDER ACROSS THE ENTIRE AREA BY LATER MONDAY NIGHT AS THE WARM SECTOR FULLY ESTABLISHES ITSELF OVER SOUTHERN MINNESOTA INTO WEST CENTRAL WISCONSIN. EXPECT AN INITIAL ARC OF PCPN ASSOCIATED WITH ELEVATED WARM ADVECTION TO LIFT INTO THE AREA LATE SUNDAY NIGHT INTO MONDAY MORNING... THEN A SECONDARY DEVELOPMENT OF PCPN BEHIND THAT OWING TO INCREASING ISENTROPIC LIFT ALONG WITH FRONTOGENESIS AND THE ARRIVAL OF ELEVATED INSTABILITY. IN ADDITION... SOME POTENT STORMS MAY DEVELOP TO OUR WEST MONDAY AFTERNOON INTO MONDAY EVENING... AND WHAT IS LEFT OF THOSE COULD WORK INTO THE AREA MONDAY NIGHT. LOW PRESSURE IS EXPECTED TO LIFT NORTHEAST INTO NORTHWEST MINNESOTA BY TUESDAY AFTERNOON... WORKING TO DRAG A COLD FRONT EAST THROUGH OUR AREA SOMEWHAT EARLY IN THE DAY. THE FRONT LOOKS TO GET ACROSS MOST OF THE MINNESOTA CWFA BY 18Z... AND THROUGH THE WISCONSIN PORTION OF THE AREA BY MID AFTERNOON. ALTHOUGH DEEP LAYER SHEAR SHOULD STILL BE QUITE STRONG ON TUESDAY... LOW LEVEL SHEAR DOES NOT LOOK TO BE AS IMPRESSIVE AS IT DID YESTERDAY... MAINLY DUE TO THE EARLIER PROGGED ARRIVAL OF THE FRONT. THE EARLIER FROPA WOULD ALSO LIMIT INSTABILITY INTO THE AREA... WHICH IS A NEGATIVE TOWARD THE SEVERE WEATHER POSSIBILITIES. SO... AT THIS POINT... THE OVERALL SEVERE WEATHER CHANCES FROM MONDAY NIGHT THROUGH TUESDAY DO NOT APPEAR PARTICULARLY HIGH ACROSS THE AREA. BUT... IT IS STILL A FEW DAYS AWAY... SO ANY CHANGES IN THE TIMING AND POSITION OF FEATURES COULD STILL CHANGE THINGS A BIT... SO IT IS WORTH KEEPING AN EYE ON THE SITUATION. STRONG WESTERLY WINDS WILL USHER IN DRIER AIR BEHIND THE FRONT LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT... WITH 850MB TEMPERATURES OF BELOW ZERO ACTUALLY MAKING IT INTO THE AREA FOR A TIME ON WEDNESDAY INTO WEDNESDAY NIGHT. HOWEVER... THIS CHANGE WILL BE SHORTLIVED ONCE AGAIN... WITH RETURN FLOW AND WARMER AIR WORKING BACK INTO THE REGION BY LATER THURSDAY AND INTO FRIDAY. CHANCES FOR SHOWERS AND A FEW THUNDERSTORMS WILL ACCOMPANY THE RETURN OF WARMER TEMPERATURES THURSDAY INTO FRIDAY WITH PERHAPS SOME SHOWER CHANCES LINGERING INTO SATURDAY AS A SHORTWAVE MOVES BY TO OUR NORTH. && .AVIATION.../00Z TAF ISSUANCE/ WE`VE GONE BACK AND FORTH TONIGHT ON HOW FAR SOUTH TO TAKE THE MVFR CEILINGS ASSOCIATED WITH THAT STRATUS DECK BEHIND THE ADVANCING COLD FRONT. THE CLOUDS HAD SLOWED THIS EVENING...BUT NOW THE PUSH OF COLD AIR SEEMS TO BE ADVANCING THE LEADING EDGE OF THE CLOUD COVER TO THE SOUTH AT 10-15KTS. THE CLOUDS SHOULD MIX OUT LATE IN THE MORNING. IN TERMS OF WINDS...AFTER SOME INITIAL GUSTS TONIGHT IN THE 10-20KT RANGE...WIND WILL REMAIN N-NE TODAY AT 5-10KTS. MID TO HIGH CLOUDS INCREASE NEAR THE END OF THE 06Z TAF PERIOD. KMSP...BASED ON THE LATEST CLOUD TREND...THE MVFR CEILINGS WOULD ARRIVE RIGHT AROUND OR JUST BEFORE 12Z IF THE CURRENT RATE HOLDS. REINTRODUCED A TEMPO GROUP FOR THE STRATUS CLOUDS BACK INTO THE TAF. SHOULDN`T LAST ALL DAY EVEN IF IT MAKES TO THE AIRPORT THIS MORNING. NOT OUT OF THE QUESTION THAT A FEW SHOWERS SNEAK IN HERE EARLY MONDAY MORNING...BUT LEFT THE TAF DRY FOR NOW. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ TRH/CLF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 AM EDT SUN MAR 25 2012 .SYNOPSIS... UNSETTLED WEATHER WILL PERSIST TODAY AS A POTENT UPPER LEVEL LOW PROGRESSES EAST OVER THE CAROLINAS. MUCH DRIER CONDITIONS WILL RETURN FOR MONDAY AND TUESDAY AS UPPER LEVEL HIGH PRESSURE BUILDS IN FROM THE WEST. && .NEAR TERM /THROUGH SUNDAY NIGHT/... AS OF 1045 PM SATURDAY... RECENT SFC ANALYSIS SHOWS A LOW PRESSURE SYSTEM CENTERED OVER THE FOOTHILLS NEAR HICKORY. CONVECTION EARLIER THIS EVENING HAS LARGELY WEAKENED AND SHIFTED NORTHEAST INTO VA. STABLE OUTFLOW FROM THE LARGE LINEAR CONVECTIVE COMPLEX HAS OVERSPREAD NEARLY ALL OF THE PIEDMONT AND INTO THE NORTHERN COASTAL PLAIN. LATEST MESOANALYSIS AND RUC PROXIMITY SOUNDINGS INDICATE THE BOUNDARY LAYER HAS STABILIZED BUT ELEVATED INSTABILITY WITH MUCAPE VALUES OF ~500 J/KG REMAIN. WITH 0-6KM BULK SHEAR VALUES OF 30-40KTS...ELEVATED ORGANIZED CONVECTION IS POSSIBLE OVERNIGHT. EXPECT THE CONVECTIVE COVERAGE TO BE SOMEWHAT LIMITED BUT WILL MAINTAIN SLIGHT CHANCE AND CHANCE POPS FOR THE OVERNIGHT. WITH THIS IN MIND...WILL CLEAR THE TORNADO WATCH FOR ALL LOCATIONS WHILE ACKNOWLEDGING THAT A STRONGER STORM WHILE NOT ROOTED IN THE BOUNDARY LAYER COULD STILL PRODUCE SOME HAIL...WITH THE WIND THREAT AND ESPECIALLY THE TORNADO THREAT MINIMAL. THE SURFACE LOW IS EXPECTED TO SHIFT SLOWLY EAST OVERNIGHT AND BE CENTERED NEAR KFAY BY DAYBREAK SUNDAY. HAVE ADJUSTED WIND FORECAST OVERNIGHT ACCORDINGLY. LOWS OVERNIGHT WILL RANGE FROM THE LOWER 50S IN THE WEST/NW PIEDMONT TO THE UPPER 50S IN THE COASTAL PLAIN. -BLAES FOR SUNDAY AND SUNDAY NIGHT...IF THERE IS A LULL IN SHOWER ACTIVITY SUNDAY MORNING...INSTABILITY SHOWERS AND THUNDERSTORMS ARE EXPECTED TO RE-DEVELOP SUNDAY AFTERNOON UNDERNEATH THE -20 TO 21C H5 COLD CORE...ESPECIALLY IN THE WARM SECTOR EAST OF THE SFC COLD FRONT WHERE STRONGER HEATING WITHIN THE LINGERING LOW-LEVEL MOISTURE TONGUE SHOULD SUPPORT MARGINAL INSTABILITY BETWEEN 500 TO 1000 J/KG OF MUCAPE. HOWEVER...VERY WEAK FLOW BENEATH THE UPPER-LEVEL LOW WILL FAVOR PULSE AS THE MAIN CONVECTIVE MODE WITH THE WIND DAMAGE AND HAIL THREATS LIKELY REMAINING MARGINAL. WILL CONTINUE TO MENTION THE THREAT OF SMALL TO MARGINALLY SEVERE HAIL FOR SUNDAY IN THE HWO. HIGHS SUNDAY AFTERNOON RANGING FROM LOWER 70S NW TO MID/UPPER 70S IN THE EAST. LOWS SUNDAY NIGHT WILL DEPEND ON THE TIMING OF THE SYSTEM EXITING...WITH DRIER AIR/CLEARING FILTERING INTO THE WESTERN PIEDMONT AOA DAYBREAK. LOWS RANGING FROM LOWER TO MID 50S NORTHWEST TO MID/UPPER 50S SOUTHEAST. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 255 AM SUNDAY... THE LATEST GFS/EUROPEAN MODELS ARE FAVORED WITH THE TIMING/STRENGTH OF THE UPPER LOW THAT WILL BE MOVING AWAY FROM OUR REGION ON MONDAY. STRONG SUBSIDENCE IN THE REAR OF THE UPPER LOW WILL COMBINE WITH A DOWNSLOPE FLOW FROM THE NNW OF 10-15 MPH OFF THE BLUE RIDGE INTO THE PIEDMONT TO BRING MOSTLY SUNNY SKIES TO CENTRAL NC MONDAY. MODELS ARE IN GOOD AGREEMENT IN THE TIMING OF A SURFACE COLD FRONT THAT IS FORECAST TO PUSH SOUTH THROUGH NC MONDAY AFTERNOON. WITH STRONG DRYING EXPECTED ALONG AND BEHIND THE FRONT... DEW POINTS ARE FORECAST TO DROP OFF INTO THE 30S BY MID TO LATE AFTERNOON. HIGHS ARE EXPECTED TO REACH 75 TO 80 WITH THE WARMEST READINGS EXPECTED ACROSS THE SANDHILLS. WITH HIGH CONFIDENCE... THE FORECAST FOR MONDAY NIGHT AND TUESDAY IS FOR BREEZY AND MUCH COOLER CONDITIONS WITH MOSTLY CLEAR SKIES MONDAY EVENING... WITH WINDS EXPECTED TO DIE OFF BY LATE EVENING. A STRONG HIGH PRESSURE WILL BUILD SOUTH FROM THE EASTERN GREAT LAKES DEEP INTO GA BY TUESDAY. ANOTHER ISSUE MAY BE A POTENTIAL FROST ADVISORY ACROSS THE NORTH MONDAY NIGHT AS TEMPERATURES CRASH AFTER THE WINDS DIE OFF. LOWS OF 35-40 EXPECTED NORTH... WITH AROUND 40 IN THE SE. THE MAIN THREAT WILL BE SCATTERED FROST IN LOW LYING AND NON-URBAN AREAS OF THE PIEDMONT BETWEEN 400 AM AND SUNRISE. HIGHS TUESDAY WILL BE MOSTLY IN THE 60S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 300 AM SUNDAY... A SPRING TEMPERATURE SEE-SAW IS EXPECTED WEDNESDAY THROUGH LATE WEEK. A RAPID WARM-UP WEDNESDAY WILL BRING HIGHS BACK INTO THE MID 70S TO AROUND 80. THIS WARMTH WILL PEAK THURSDAY WHEN THERE MAY BE A CHANCE OF A SHOWER OR THUNDERSTORM DEPENDING ON THE TIMING OF THE NEXT COLD FRONT. THIS WARMTH WILL BE FOLLOWED BY ANOTHER QUICK SHOT OF COOLER AIR WITH HIGHS BACK INTO THE 65-72 RANGE EXPECTED BY FRIDAY. MOST GUIDANCE SUGGESTS LOWS SHOULD STAY ABOVE THE FROST THRESHOLD DURING THE NEXT COOL SNAP FRIDAY MORNING (MOSTLY 38+ DEGREES). && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 215 AM SUNDAY... 24-HR TAF PERIOD: SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL PERSIST THROUGH THE TAF PERIOD AS A POTENT UPPER LEVEL LOW PROGRESSES EAST/SE THROUGH THE CAROLINAS. TRANSIENT SUB-VFR CONDITIONS CAN BE EXPECTED IN ASSOC/W ANY CONVECTION THROUGHOUT THE TAF PERIOD. ADDITIONALLY... MVFR/IFR CEILINGS AND/OR MVFR VISBYS WILL BE POSSIBLE AT ANY TAF SITE THROUGH 12Z THIS MORNING IN ASSOC/W A RESIDUAL MOIST BOUNDARY LAYER AND NOCTURNAL COOLING. WINDS WILL BE LIGHT/VARIABLE THROUGH 18-21Z THIS AFTERNOON...EVENTUALLY BECOMING NORTHWEST AT 5-10 KT BY THE END OF THE TAF PERIOD AS THE UPPER LEVEL LOW AND IT`S SURFACE REFLECTION PROGRESS OFFSHORE THE CAROLINA COAST AND HIGH PRESSURE BEGINS BUILDING INTO THE AREA FROM THE NORTHWEST. LOOKING AHEAD: CLEAR SKIES/VFR CONDITIONS ASSOCIATED WITH AN UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE WILL PREVAIL OVER CENTRAL NC MONDAY/TUESDAY. MVFR/IFR CEILINGS WILL BE POSSIBLE WEDNESDAY MORNING AS HIGH PRESSURE SHIFTS OFFSHORE AND A MOIST SOUTHERLY RETURN FLOW DEVELOPS. SUB-VFR CONDITIONS WILL ALSO BE POSSIBLE WEDNESDAY NIGHT AND THURSDAY IN ASSOC/W A BACKDOOR COLD FRONT EXPECTED TO PROGRESS SLOWLY SOUTHWARD THROUGH CENTRAL NC. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...BLAES/CBL SHORT TERM...BADGETT LONG TERM...BADGETT AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
222 AM EDT SUN MAR 25 2012 .SYNOPSIS... UNSETTLED WEATHER WILL PERSIST TODAY AS A POTENT UPPER LEVEL LOW PROGRESSES EAST THROUGH THE CAROLINAS. DRY AND SUNNY CONDITIONS WILL RETURN FOR MONDAY AND TUESDAY AS AN UPPER LEVEL RIDGE BUILDS OVER THE CAROLINAS FROM THE WEST. && .NEAR TERM /THROUGH SUNDAY NIGHT/... AS OF 1045 PM SATURDAY... RECENT SFC ANALYSIS SHOWS A LOW PRESSURE SYSTEM CENTERED OVER THE FOOTHILLS NEAR HICKORY. CONVECTION EARLIER THIS EVENING HAS LARGELY WEAKENED AND SHIFTED NORTHEAST INTO VA. STABLE OUTFLOW FROM THE LARGE LINEAR CONVECTIVE COMPLEX HAS OVERSPREAD NEARLY ALL OF THE PIEDMONT AND INTO THE NORTHERN COASTAL PLAIN. LATEST MESOANALYSIS AND RUC PROXIMITY SOUNDINGS INDICATE THE BOUNDARY LAYER HAS STABILIZED BUT ELEVATED INSTABILITY WITH MUCAPE VALUES OF ~500 J/KG REMAIN. WITH 0-6KM BULK SHEAR VALUES OF 30-40KTS...ELEVATED ORGANIZED CONVECTION IS POSSIBLE OVERNIGHT. EXPECT THE CONVECTIVE COVERAGE TO BE SOMEWHAT LIMITED BUT WILL MAINTAIN SLIGHT CHANCE AND CHANCE POPS FOR THE OVERNIGHT. WITH THIS IN MIND...WILL CLEAR THE TORNADO WATCH FOR ALL LOCATIONS WHILE ACKNOWLEDGING THAT A STRONGER STORM WHILE NOT ROOTED IN THE BOUNDARY LAYER COULD STILL PRODUCE SOME HAIL...WITH THE WIND THREAT AND ESPECIALLY THE TORNADO THREAT MINIMAL. THE SURFACE LOW IS EXPECTED TO SHIFT SLOWLY EAST OVERNIGHT AND BE CENTERED NEAR KFAY BY DAYBREAK SUNDAY. HAVE ADJUSTED WIND FORECAST OVERNIGHT ACCORDINGLY. LOWS OVERNIGHT WILL RANGE FROM THE LOWER 50S IN THE WEST/NW PIEDMONT TO THE UPPER 50S IN THE COASTAL PLAIN. -BLAES FOR SUNDAY AND SUNDAY NIGHT...IF THERE IS A LULL IN SHOWER ACTIVITY SUNDAY MORNING...INSTABILITY SHOWERS AND THUNDERSTORMS ARE EXPECTED TO RE-DEVELOP SUNDAY AFTERNOON UNDERNEATH THE -20 TO 21C H5 COLD CORE...ESPECIALLY IN THE WARM SECTOR EAST OF THE SFC COLD FRONT WHERE STRONGER HEATING WITHIN THE LINGERING LOW-LEVEL MOISTURE TONGUE SHOULD SUPPORT MARGINAL INSTABILITY BETWEEN 500 TO 1000 J/KG OF MUCAPE. HOWEVER...VERY WEAK FLOW BENEATH THE UPPER-LEVEL LOW WILL FAVOR PULSE AS THE MAIN CONVECTIVE MODE WITH THE WIND DAMAGE AND HAIL THREATS LIKELY REMAINING MARGINAL. WILL CONTINUE TO MENTION THE THREAT OF SMALL TO MARGINALLY SEVERE HAIL FOR SUNDAY IN THE HWO. HIGHS SUNDAY AFTERNOON RANGING FROM LOWER 70S NW TO MID/UPPER 70S IN THE EAST. LOWS SUNDAY NIGHT WILL DEPEND ON THE TIMING OF THE SYSTEM EXITING...WITH DRIER AIR/CLEARING FILTERING INTO THE WESTERN PIEDMONT AOA DAYBREAK. LOWS RANGING FROM LOWER TO MID 50S NORTHWEST TO MID/UPPER 50S SOUTHEAST. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 PM SATURDAY... ON MONDAY THE UPPER LEVEL LOW WILL EXIT OFF THE ATLANTIC COAST AND AN H500 RIDGE WILL MOVE EAST TO TAKE ITS PLACE. AT THE SURFACE THE PARENT HIGH WILL MOVE INTO WESTERN ONTARIO. LOW LEVEL FLOW WILL BE OUT OF THE NORTH ON MONDAY AND CONDITIONS MAY BECOME GUSTY BY AFTERNOON IN A WELL MIXED LAYER...15-20 KNOTS. THE ONSET OF COLD AIR ADVECTION WILL BE GENERALLY WEAK DURING THE AFTERNOON BUT WILL INCREASE OVERNIGHT. THIS WILL LEAVE ONE MORE DAY OF HIGH TEMPERATURES CLOSE TO 80 DEGREES. WITH DEWPOINTS RUNNING IN THE 40S...DRY AND PLEASANT CONDITIONS WILL PREVAIL THROUGHOUT THE DAY. HIGHS NEAR 80 WITH LOWS TUESDAY MORNING IN THE MID 40S. STRONGER COLD AIR ADVECTION WILL BEGIN OVERNIGHT MONDAY AND EARLY TUESDAY MORNING AS THE UPPER LEVEL FLOW TURNS NORTHWESTERLY. THE DAY WILL ONCE AGAIN BE DRY AS HIGH PRESSURE MOVES OVER THE REGION WITH LIGHT EASTERLY WINDS AT THE SURFACE. HIGHS WILL BE ON THE ORDER OF 15 DEGREES COOLER THAN MONDAY AS THICKNESSES DROP 40-50 METERS. HIGHS IN THE MID 60S...LOWS IN THE UPPER 40S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 300 PM SATURDAY... ON WEDNESDAY THE SURFACE HIGH MOVES OFF THE CAROLINA COAST. A SURFACE LOW WILL TRACK OVER THE GREAT LAKES WITH ITS ASSOCIATED SHORTWAVE TROUGH. EXPECT SOUTHWESTERLY FLOW ON WEDNESDAY AS CENTRAL NC WILL BE STUCK BETWEEN THE DEPARTING HIGH AND THE APPROACHING LOW. ANY PRECIPITATION WITH THE FRONT SHOULD STAY WELL NORTH OF THE AREA ON WEDNESDAY...KEEPING CONDITIONS WARM AND DRY. HIGH TEMPERATURES WILL RECOVER ABOUT 10 DEGREES FROM TUESDAY AND MOISTURE ADVECTION WILL BEGIN FROM THE SOUTH AS DEWPOINTS WILL RISE INTO THE 50S BY THE END OF THE DAY. HIGHS MID TO UPPER 70S WITH LOWS THURSDAY MORNING IN THE LOWER 50S. THURSDAY IS THE MOST UNCERTAIN DAY IN THE LONG TERM WITH REGARDS TO WHETHER OR NOT THE FRONT DROPPING DOWN FROM THE NORTH WILL FOR ONE MAKE IT COMPLETELY THROUGH THE CWA...AND TWO IF IT WILL BRING PRECIPITATION OR NOT. AT CURRENT TIME THE ECMWF BRINGS IT THROUGH AS A DRY FRONT BY 12Z THURSDAY...WHILE THE GFS IS A LITTLE BIT MORE ROBUST BRINGING SOME SHOWERS THROUGH AT LEAST THE NORTHERN PORTION OF THE CWA AND THEN DRIES OUT WHILE LINGERING ACROSS THE SOUTH THROUGH 18Z OR SO. FOR THIS FORECAST PACKAGE...WILL INTRODUCE SLIGHT CHANCE OF POPS IN THE NORTH AND KEEP THE SOUTHERN PORTION OF THE CWA DRY...SOUTH OF HIGHWAY 64. WITH THE FRONT LINGERING...TEMPERATURES WILL STILL MAKE IT UP INTO THE UPPER 70S TO LOWER 80S WITH A LITTLE BIT COOLER ACROSS THE NORTH. WINDS WILL BE LIGHT AND GRADUALLY VEER TO NORTHWESTERLY AS THE FRONT MOVES SOUTH. LOWS THURSDAY NIGHT UPPER 40S TO LOW 50S. FRIDAY AND SATURDAY WILL BE GENERALLY DRY BEHIND THE FRONT ALTHOUGH THERE IS SOME UNCERTAINTY ON SATURDAY AS A WEAK FRONTAL SYSTEM APPROACHES FROM THE WEST. THE ECMWF KEEPS THE AREA DRY...HOLDING OFF PRECIPITATION UNTIL SUNDAY WHEREAS THE GFS BRINGS IN SCATTERED SHOWERS BY SATURDAY AFTERNOON. SINCE THIS SYSTEM APPEARS WEAK AT THIS TIME...TIMING OF THE ONSET OF PRECIPITATION MAY BE LARGELY DETERMINED BY HOW FAR OFF OF THE COAST THE SURFACE HIGH SETTLES ON SATURDAY. WITH LIGHT UPPER LEVEL FLOW...WILL GO WITH THE ECMWF AT THIS TIME WHICH KEEPS THE HIGH CLOSER TO SHORE AND THUS DRY CONDITIONS FOR SATURDAY. HIGHS DURING THIS PERIOD WILL BE IN THE UPPER 60S TO LOW 70S WITH LOWS IN THE UPPER 40S TO LOWER 50S. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 215 AM SUNDAY... 24-HR TAF PERIOD: SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL PERSIST THROUGH THE TAF PERIOD AS A POTENT UPPER LEVEL LOW PROGRESSES EAST/SE THROUGH THE CAROLINAS. TRANSIENT SUB-VFR CONDITIONS CAN BE EXPECTED IN ASSOC/W ANY CONVECTION THROUGHOUT THE TAF PERIOD. ADDITIONALLY... MVFR/IFR CEILINGS AND/OR MVFR VISBYS WILL BE POSSIBLE AT ANY TAF SITE THROUGH 12Z THIS MORNING IN ASSOC/W A RESIDUAL MOIST BOUNDARY LAYER AND NOCTURNAL COOLING. WINDS WILL BE LIGHT/VARIABLE THROUGH 18-21Z THIS AFTERNOON...EVENTUALLY BECOMING NORTHWEST AT 5-10 KT BY THE END OF THE TAF PERIOD AS THE UPPER LEVEL LOW AND IT`S SURFACE REFLECTION PROGRESS OFFSHORE THE CAROLINA COAST AND HIGH PRESSURE BEGINS BUILDING INTO THE AREA FROM THE NORTHWEST. LOOKING AHEAD: CLEAR SKIES/VFR CONDITIONS ASSOCIATED WITH AN UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE WILL PREVAIL OVER CENTRAL NC MONDAY/TUESDAY. MVFR/IFR CEILINGS WILL BE POSSIBLE WEDNESDAY MORNING AS HIGH PRESSURE SHIFTS OFFSHORE AND A MOIST SOUTHERLY RETURN FLOW DEVELOPS. SUB-VFR CONDITIONS WILL ALSO BE POSSIBLE WEDNESDAY NIGHT AND THURSDAY IN ASSOC/W A BACKDOOR COLD FRONT EXPECTED TO PROGRESS SLOWLY SOUTHWARD THROUGH CENTRAL NC. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...BLAES/CBL SHORT TERM...RTE LONG TERM...RTE AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1151 PM CDT SAT MAR 24 2012 .AVIATION... FOR THE 06Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR ALL SITES WITH THE EXCEPTION OF WACO THROUGH THE VALID FORECAST PERIOD. AREAS OF GROUND FOG MAY CAUSE VISIBILITY RESTRICTIONS AT WACO AROUND SUNRISE. THERE HAS BEEN NO SIGNIFICANT CHANGE IN THE THINKING FROM THE 00Z TAFS. SURFACE RIDGING IS EXPECTED TO BE IN PLACE OVER NORTHEAST TEXAS BY SUNRISE ON SUNDAY. THIS WILL ALLOW SHALLOW MOISTURE TO MOVE NORTHWEST INTO THE SOUTHWESTERN HALF OF NORTH TX. AT THIS TIME SHALLOW MOISTURE LOOKS AS THOUGH IT WILL BE MOST ROBUST AT KACT AND SHOULD REMAIN SOUTHWEST OF METROPLEX TAF SITES THROUGH SUNRISE. ASSUMING SHALLOW FOG PANS OUT...A FEW HOURS OF LOW MVFR OR IFR VSBYS CAN BE EXPECTED AT WACO UNTIL DAYTIME HEATING QUICKLY MIXES OUT THE SHALLOW MORNING INVERSION. ONCE THE INVERSION MIXES EXPECT A RAPID DISPERSION OF GROUND FOG AROUND WACO. VFR CONDITIONS AND SOUTHERLY FLOW IS EXPECT FOR THE REMAINDER OF THE FORECAST PERIOD. CAVANAUGH .../PREVIOUS AVIATION DISCUSSION/... FOR THE 00Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE VALID FORECAST PERIOD EXCEPT FOR THE POSSIBILITY OF SOME EARLY MORNING FOG AROUND WACO. A SURFACE RIDGE OF HIGH PRESSURE IN PLACE OVER NORTH TX WILL SLIDE SLOWLY OFF TO THE NORTHEAST THROUGH THE OVERNIGHT HRS. THIS WILL ALLOW FOR A RETURN OF SHALLOW MOISTURE TO THE AREA SOUTHWEST OF THE RIDGE AXIS BY SUNRISE. LATEST GUIDANCE INDICATES THAT THIS RETURN OF SHALLOW MOISTURE WILL REMAIN SOUTHWEST OF METROPLEX AREA TAF SITES...BUT WILL END UP AFFECTING THE WACO AREA JUST BEFORE SUNRISE. BASED ON LATEST RUC FORECAST SOUNDINGS DECIDED TO INCLUDE A FEW HRS OF IFR VSBYS AT KACT IN THE 11 TO 15Z TIMEFRAME AS A SHALLOW INVERSION OF TEMPERATURE AND MOISTURE IS INDICATED. WITH CLEAR SKIES AND LIGHT WIND IN PLACE THIS SET-UP SHOULD RESULT IN AREAS OF GROUND FOG WITHIN THIS TIMEFRAME. AFTER A COUPLE OF HOURS OF HEATING...EXPECT THIS SHALLOW INVERSION TO MIX OUT RESULTING IN A QUICK DISPERSION OF ANY GROUND FOG NEAR KACT. VFR CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE FORECAST PERIOD. CAVANAUGH && .UPDATE... TEMPERATURES WERE RUNNING A BIT WARMER THAN PREVIOUSLY FORECAST OVER AREAS NORTHEAST OF THE DALLAS FORT WORTH METROPLEX. WILL INCREASE OVERNIGHT LOWS BY A FEW DEGREES IN THESE AREAS BASED ON TRENDS AND NEW GUIDANCE. OTHERWISE PATCHY FOG STILL LOOKS LIKE A POSSIBILITY PRIMARILY SOUTH OF I 20 BY SUNRISE. 30 && .PREV DISCUSSION... /ISSUED 336 PM CDT SAT MAR 24 2012/ SURFACE RIDGE AXIS REMAINS OVER THE EASTERN CWA WITH WEAK SOUTHERLY FLOW OVER THE WESTERN ZONES BEGINNING TO BRING HIGHER GULF MOISTURE NORTHWARD. DENSE FOG DEVELOPED OVER THE HILL CENTRAL AND SOUTHEAST TEXAS LAST NIGHT. EXPECT FOG TO DEVELOP AGAIN TONIGHT...THIS TIME A LITTLE FARTHER NORTH...PRIMARILY ALONG AND WEST OF THE BRAZOS RIVER VALLEY WHERE TONGUE OF HIGHER SURFACE MOISTURE WILL SET UP. ASIDE FROM ANY FOG...A GENERALLY CLEAR...CALM...AND COMFORTABLE NIGHT IS IN STORE. ANOTHER MILD AND PLEASANT DAY IS EXPECTED SUNDAY WITH HIGHS IN THE LOWER 80S. SURFACE RIDGE WILL SHIFT TO THE EAST BY SUNDAY NIGHT AND SOUTHERLY WINDS WILL GRADUALLY INCREASE TO 10-15 MPH BY MONDAY. AS A RESULT GULF MOISTURE AND OVERNIGHT LOW TEMPS SLOWLY INCREASE EARLY NEXT WEEK...BUT HIGH TEMPS REMAIN MILD. CLOUD COVER IS EXPECTED TO ARRIVE MONDAY NIGHT AND TUESDAY AS A SHORTWAVE TRACKS ACROSS COLORADO AND INTO THE NORTHERN PLAINS. A FEW STORMS MAY FIRE ALONG THE DRY LINE IN THE TX PANHANDLE MONDAY EVENING BUT THE FORCING REMAINS WELL NORTHWEST OF OUR AREA FOR ANY RAIN CHANCES HERE. MID-HIGH CLOUD COVER WILL BE MOST ABUNDANT ON TUESDAY WHICH MAY HOLD AFTERNOON HIGHS DOWN A DEGREE OR TWO FROM MONDAY/S READINGS. OTHERWISE WITH SOUTHERLY FLOW CONTINUING... EXPECT MORNING STRATUS AND AFTERNOON SUN WITH HIGHS NEAR 80 AND LOWS NEAR 60 FOR THE MIDWEEK PERIOD. MODELS ARE IN DECENT AGREEMENT IN THE SYNOPTIC PATTERN BY THE END OF THE WEEK. THE WESTERLIES ARE EXPECTED TO WEAKEN ACROSS THE REGION AS THE POLAR JET SETS UP OVER THE CANADIAN BORDER AND THE SUBTROPICAL JET BECOMES SITUATED ACROSS CENTRAL MEXICO. IN THE VOID BETWEEN THE TWO...IT APPEARS THE SYNOPTIC ENVIRONMENT WILL BE FAVORABLE FOR A SHORTWAVE TO INTENSIFY INTO A SLOW MOVING UPPER LOW OVER TEXAS BY FRIDAY. THE INTENSIFICATION OF THE SHORTWAVE INTO AN UPPER LOW RESULTS PRIMARILY FROM AN ATMOSPHERIC CONVECTIVE FEEDBACK...WHERE THE RELEASE OF LATENT HEAT FROM CONVECTION /NOT THERMAL GRADIENTS/ STRENGTHEN THE VORTEX. GFS/ECMWF/GEM ALL SHOW THIS UPPER LOW BECOMING A VERTICALLY STACKED AND WARM-CORE SYSTEM...WITH THE CYCLONIC CIRCULATION EXTENDING DOWN TO THE SURFACE. CYCLONES OF THIS NATURE ARE NOT UNCOMMON IN THE SUMMER MONTHS AND ARE NOTORIOUS FOR HEAVY RAIN. HOWEVER...SINCE THIS IS OCCURRING SO EARLY IN THE YEAR...MOISTURE/INSTABILITY CONTENT IS PROBABLY NOT HIGH ENOUGH TO RESULT IN SIGNIFICANT CONVECTION OR HEAVY RAINS. THE BEST CHANCES OF RAIN WILL PROBABLY OCCUR ON FRIDAY WHEN THE LOW IS OVERHEAD...BUT WILL BE CONSERVATIVE WITH POPS FOR NOW. HIGH TEMPS SHOULD COOL INTO THE 70S DUE TO CLOUD COVER AND SCATTERED RAIN SHOWERS...WITH LOWS IN THE LOW-MID 60S. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 57 83 59 83 61 / 0 0 0 0 10 WACO, TX 55 82 56 83 58 / 0 0 0 0 5 PARIS, TX 52 80 53 82 57 / 0 0 0 0 5 DENTON, TX 51 83 56 83 59 / 0 0 0 0 10 MCKINNEY, TX 50 81 53 81 57 / 0 0 0 0 10 DALLAS, TX 58 83 60 83 61 / 0 0 0 0 10 TERRELL, TX 51 82 55 82 58 / 0 0 0 0 5 CORSICANA, TX 57 83 56 82 58 / 0 0 0 0 5 TEMPLE, TX 56 83 56 83 57 / 0 0 0 0 5 MINERAL WELLS, TX 57 84 55 83 57 / 0 0 0 0 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1121 PM CDT SAT MAR 24 2012 .DISCUSSION...UPDATED FOR 06Z AVIATION DISCUSSION BELOW. && .AVIATION...TERMINALS WILL TRANSITION FROM VFR TO IFR BY LATE TONIGHT WITH A SLOW RETURN BACK TO VFR BY SUN AFTN. AS OF WRITING STRATUS WAS DVLPING ALONG MID TX COAST WITH KCRP FLIRTING WITH IFR CRITERIA. XPCTING STRATUS DECK TO BUILD INLAND THRU THE NIGHT WITH CIGS LOWERING TO IFR LEVELS AND AFFECTING ALL TERMINALS BY SUNRISE. AREAS OF FOG ALSO POSSIBLE IF STRATUS IS SLOWER TO DVLP INLAND. KALI AND KVCT MAY XPERIENCE IFR VSBYS IF FOG AFFECTS TERMINALS. BY LATE SUN MRNG AND THRU THE AFTN STRATUS SHOULD MIX OUT WITH CIGS RISING AND CONDITIONS BECOMING VFR ALL TERMINALS. LIGHT WINDS TONIGHT WILL CONTINUE THRU SUN MRNG AND INCREASE TO MODERATE LEVELS SUN AFTN. && .PREV DISCUSSION... /ISSUED 1000 PM CDT SAT MAR 24 2012/ DISCUSSION...CURRENT OBS AND MSAS DATA INDICATE HIGHER SWATH OF MOISTURE LOCATED ALONG AND OFFSHORE OF THE SOUTHERN COASTAL BEND AND LOWER TEXAS COAST. THIS MOISTURE...ALBEIT SHALLOW...WILL CONTINUE TO ADVECT INLAND OVERNIGHT WITH STRATUS LIKELY TO DEVELOP ALONG WITH SOME FOG. NAM AND RUC PROG GREATEST FOG POTENTIAL TO BE LOCATED INLAND ALONG AND IN BETWEEN THE HWY 281 AND 77 CORRIDORS. CHANGES TO THE FORECAST WERE TO ALTER DIURNAL DROP OF HOURLY TEMPS ACROSS THE REGION TO SHOW MORE TEMPERATE COOLING THIS EVENING AND TO CHANGE DEWPOINTS TO REFLECT HIGHER MOISTURE VALUES MOVING ONSHORE. ALSO ENHANCED FOG WORKING SLIGHTLY FOR AREAS MENTIONED ABOVE. UPDATED PRODUCTS WILL BE OUT SHORTLY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 65 84 64 83 66 / 0 0 10 0 10 VICTORIA 61 83 60 84 62 / 0 0 10 0 10 LAREDO 68 91 68 90 69 / 0 10 10 10 10 ALICE 65 86 65 86 64 / 0 0 10 10 10 ROCKPORT 67 80 67 80 68 / 0 0 10 0 10 COTULLA 62 86 63 86 64 / 0 10 10 10 10 KINGSVILLE 65 83 65 85 65 / 0 0 10 0 10 NAVY CORPUS 68 79 66 79 69 / 0 0 10 0 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ AVIATION...HART/79
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1059 AM EDT SUN MAR 25 2012 .SYNOPSIS... SLOW MOVING LOW PRESSURE OVER THE MID ATLANTIC REGION WILL PASS TO THE SOUTH INTO TONIGHT...THEN HEAD NORTHEAST OUT TO SEA AND STRENGTHEN THROUGH MONDAY. A STRONG COLD FRONT WILL MOVES THROUGH MONDAY MORNING IN ITS WAKE. HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH MONDAY AFTERNOON THROUGH TUESDAY...AND THEN SLIDE EAST TUESDAY NIGHT. LOW PRESSURE AND AN ASSOCIATED FRONTAL SYSTEM WILL MOVE ACROSS FROM WEDNESDAY INTO EARLY THURSDAY...FOLLOWED BY HIGH PRESSURE LATER THURSDAY INTO FRIDAY. A WARM FRONT WILL APPROACH LATE FRIDAY NIGHT INTO SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 850 WARM FRONT HAS LIFTED TO OUR NORTH...SO STEADY PRECIPITATION HAS COME TO AN END...LATEST GUIDANCE AND RADAR TRENDS SUGGEST ONLY NEEDING POPS FOR ISOLD-SCT -SHRA FOR REMAINDER OF DAY...AND FORECAST HAS BEEN ADJUSTED ACCORDINGLY. EVEN WITH 850 WARM FRONT TO OUR N...MODEL AND 12Z KOKX AND KALY SUGGEST MIXING TO AT MOST 950 HPA...WITH RELATIVELY STRONG ENE FLOW KEEPING A MARITIME AIRMASS IN PLACE. HAVE ADJUSTED HIGHS DOWNWARD BASED ON BLEND OF MIXING DOWN FROM 950 HPA AWAY FROM THE COAST...WITH LAV AND MET GUIDANCE AS WELL AS NAM AND HRRR 2-METER TEMPERATURES. THIS LOWERED HIGHS ABOUT 1 CATEGORY AWAY FROM THE COAST. STILL HAVE SOME CONCERN THIS MIGHT END UP BEING TO WARM...AND ULTIMATELY WE WILL END UP TOPPING OUT FROM THE UPPER 40S ACROSS NORTHERN INTERIOR ZONES TO LOWER 50S COASTAL/NYC METRO ZONES...BUT NOT QUITE CONFIDENT ENOUGH TO MAKE THAT CHANGE YET. IF CURRENT TRENDS HOLD THOUGH...WILL MAKE THAT CHANGE IN THE NEXT UPDATE WHICH WILL GO OUT BY ABOUT 1230 THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... THE UPPER LOW SHEARS NORTH INTO A STRONG NORTHERN STREAM SHORTWAVE DIGGING THROUGH THE NORTHEAST ON TONIGHT INTO MONDAY. AT THE SURFACE...LOW PRESSURE TRACKS NE FROM EAST OF CAPE COD TONIGHT TO THE EAST OF THE CANADIAN MARITIMES ON MONDAY. MEANWHILE ANOTHER LOW...ASSOCIATED WITH THE NORTHERN STREAM SHORTWAVE...TRACKS EAST THROUGH QUEBEC INTO SE CANADA TONIGHT INTO MON MORNING...PUSHING A STRONG COLD FRONT ACROSS THE AREA MONDAY MORNING. THE NORTHERN STREAM AND COASTAL LOW WILL EVENTUALLY MERGE INTO A STRONG COASTAL LOW OVER THE CANADIAN MARITIMES BY MON AFTERNOON...AND THEN GRADUALLY TRACK UP THE COAST. DRYING CONDITIONS EXPECTED TONIGHT IN THE WAKE OF THE WEAK SHORTWAVE AND DEPARTING LOW...BUT STILL UNSEASONABLY MILD AHEAD OF COLD FRONT. THEN CHILLY CONDITIONS EXPECTED ON MONDAY IN THE WAKE OF THE COLD FRONTAL PASSAGE...WITH MODERATELY STRONG NW WINDS (20 TO 30 MPH WITH GUSTS UP TO 40 MPH) PROVIDING STRONG CAA. WIND ADVISORY CONDITIONS LOOK TO BE ISOLATED. SCT-BKN AFTERNOON CLOUD COVER LIKELY AS AS THE STRONG NORTHERN STREAM SHORTWAVE PIVOTS THROUGH THE REGION AS WELL. TEMPS WILL LIKELY PEAK IN THE MORNING...AND THEN SLOWLY FALL DURING THE DAY WITH CLOUD COVER AND CAA. HIGH TEMPS FORECAST IS TRICKY DUE TO THE EXACT TIMING OF THE FRONT...BUT TEMPS LIKELY SLOWLY FALL THROUGH THE 50S INTO THE 40S DURING THE AFTERNOON. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... DEEP TROUGH GRADUALLY PIVOTS OFFSHORE MON NIGHT INTO TUESDAY...WITH CANADIAN HIGH PRESSURE BUILDING DOWN FROM HUDSON BAY. THE RESULT WILL BE DRY BUT CONTINUED WINDY CONDITIONS MONDAY NIGHT INTO TUESDAY AFTERNOON BETWEEN THE STRONG CANADIAN MARITIMES LOW AND HIGH PRESSURE BUILDING DOWN FROM HUDSON BAY. RIDGING SURFACE/ALOFT BUILDS OVERHEAD TUESDAY NIGHT. NOTE FOR AGRICULTURAL AND HORTICULTURAL CONCERNS...TEMPS ARE EXPECTED TO FALL INTO THE LOWER TO MID 20S ACROSS NORTHERN ZONES...MID TO UPPER 20S COAST...AND AROUND FREEZING IN THE NYC/NJ METRO MON NIGHT. SUB- FREEZING TEMPS ARE ALSO POSSIBLE TUE NIGHT OUTSIDE OF URBAN CENTERS IF RADIATIONAL COOLING CONDITIONS ARE RIGHT. WINDS WILL BE LIGHT BUT SOME INCREASING HIGH/MID LEVEL CLOUDS MAY MITIGATE THIS SOMEWHAT. MORE ROBUST WAA SHOULD TAKE PLACE TUE NIGHT-WED IN RETURN S-SW FLOW AS THE HIGH SLIDES TO THE E-SE AND A WARM FRONT APPROACHES...WITH HIGHS REBOUNDING TO THE UPPER 50S/LOWER 60S. EXPECT A CHANCE OF SHOWERS MAINLY WED AFTERNOON/NIGHT AS THIS FRONT MOVES THROUGH AND A COLD FRONT TRAILING FROM LOW PRESSURE PASSING TO THE NORTH APPROACHES...THEN ONLY SLIGHTLY COOLER BUT STILL ABOVE AVG TEMPS ON THU/FRI AS ANOTHER HIGH BUILDS IN...WITH 50S TO NEAR 60. AFTER THIS HIGH MOVES EAST... ANOTHER WARM FRONT WILL APPROACH LATE FRI NIGHT INTO SAT WITH ANOTHER CHANCE OF SHOWERS. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... A WARM FRONT REMAINS TO THE SOUTH...WHILE LOW PRESSURE MOVES SLOWLY ACROSS THE MID ATLANTIC REGION. A COLD FRONT GRADUALLY MOVES ACROSS THE REGION MONDAY MORNING. SCATTERED SHOWERS WILL DIMINISH IN COVERAGE LATER THIS AFTERNOON. CIGS HAVE BEEN MVFR WITH VSBYS STAYING VFR. OCCASIONAL MVFR VSBYS WILL BE POSSIBLE WITH SOME SHOWERS AS WELL AS SOME WIND GUSTS BETWEEN 15 AND 20 KTS BUT DO NOT THINK THESE WILL OCCUR OFTEN ENOUGH TO INCLUDE IN TAF FOR MOST SITES. CIGS WILL BE SLOW TO IMPROVE WITH THE STEADY EASTERLY FLOW AROUND 10 KTS. WINDS BACK TO MORE NE DIRECTION LATER THIS AFTERNOON AT LESS THAN 10 KTS. LINGERING MOISTURE WILL KEEP MVFR CIGS ACROSS MOST TERMINALS WITH IFR CIGS POSSIBLE AT OUTLYING TERMINALS FOR AT LEAST A PART OF THE EVENING. COLD FRONT APPROACHES LATER TONIGHT AND A MORE NORTHERLY FLOW WILL LEAD TO DRIER AIR WITH VFR RETURNING. NW WINDS INCREASE 10-15 KT BY DAYBREAK MONDAY. OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY... .MONDAY-TUESDAY...VFR. COLD FRONT MOVES THROUGH MONDAY MORNING... FOLLOWED BY GUSTY NW-N FLOW. DIMINISHING WINDS TUESDAY AFTERNOON. .WEDNESDAY...MVFR CONDITIONS ARE POSSIBLE IN THE AFTERNOON AND AT NIGHT AS LOW PRESSURE AND A WARM FRONT APPROACH. GUSTY SW FLOW IN THE AFTERNOON. .THURSDAY...VFR. GUSTY NW FLOW. && .MARINE... MINOR CHANGES MADE TO REFLECT LATEST TRENDS IN THE OBSERVATIONS AND GUIDANCE...FORECAST APPEARS ON TRACK. MARGINAL SCA ENE WIND GUSTS ON THE OCEAN WILL CONTINUE INTO THIS AFTERNOON AND THEN WEAKEN THIS EVENING AS A WEAK SURFACE TROUGH WORKS ACROSS THE AREA. 5 TO 6 FT OCEAN SEAS MAY BRIEFLY FALL BELOW SCA TONIGHT. THEN STRONG SCA CONDITIONS EXPECTED ON ALL WATERS...WITH MARGINAL GALE CONDITIONS ON THE OCEAN EXPECTED MON MORNING THROUGH MON NIGHT IN THE WAKE OF A STRONG COLD FRONTAL PASSAGE. HAVE ISSUED GALE WATCH FOR THE OCEAN WATERS TO ADDRESS THIS POTENTIAL...AND SCA ELSEWHERE DURING THIS TIME. CONDITIONS SHOULD GRADUALLY FALL THROUGH SCA AND THEN BELOW ON TUE AS HIGH PRESSURE BUILDS INTO THE REGION. SCA CONDITIONS POSSIBLE ONCE AGAIN ON THE OCEAN WATERS WED AFTERNOON/NIGHT IN STRENGTHENING S-SW FLOW AHEAD OF A COLD FRONT...AND AGAIN THE AFTERNOON/EVENING IN POST-FRONTAL NW FLOW. && .FIRE WEATHER... LACK OF RAINFALL...AND COMBINATION OF STRONG WINDS(20 TO 30 MPH WITH GUSTS UP TO 40 MPH) AND LOW RH VALUES (LOWER 20S PERCENT) ON MONDAY WILL RESULT IN A SIGNIFICANTLY ENHANCED THREAT FOR THE SPREAD OF BRUSH FIRES. WILL ADDRESS POTENTIAL IN HWO. && .HYDROLOGY... RELATIVELY DRY CONDITIONS WILL CONTINUE...WITH NO SIGNIFICANT QPF OF 1/2 INCH OR MORE EXPECTED FOR THE NEXT 7 DAYS. IN FACT...THE U.S. DROUGHT MONITOR CATEGORIZES SE CT AS BEING IN MODERATE DROUGHT...AND THE REST OF THE REGION AS ABNORMALLY DRY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 AM MONDAY TO 6 AM EDT TUESDAY FOR ANZ330-335-338-340-345. GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR ANZ350-353-355. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ350- 353-355. && $$ SYNOPSIS...MALOIT/NV NEAR TERM...MALOIT SHORT TERM...NV LONG TERM...NV/GOODMAN AVIATION...MPS/JM MARINE...MALOIT/NV/GOODMAN FIRE WEATHER...NV HYDROLOGY...NV
AREA FORECAST DISCUSSION
NWS MIAMI FL
902 AM EDT SUN MAR 25 2012 .UPDATE... AREA OF SHOWERS/ISOLATED TSTMS AFFECTING WESTERN HALF OF SOUTH FLORIDA PENINSULA THIS MORNING AHEAD OF A COLD FRONT OVER CENTRAL FLORIDA DEPICTED FAIRLY WELL IN CURRENT FORECAST. 12Z MIAMI SOUNDINGS SHOWS DECENT INSTABILITY WITH RATHER STEEP LAPSE RATES BETWEEN 750 AND 600 MB AND ONLY WEAK CAPPING. THIS SHOULD SUPPORT ISOLATED TSTMS THROUGHOUT THE DAY, BUT MOST LIKELY DURING PEAK HEATING THIS AFTERNOON OVER EASTERN SECTIONS. SHORT RANGE MODELS SHOW AREA OF PRECIP OVER WESTERN AREAS GRADUALLY DISSIPATING AND TRANSITIONING TO SCATTERED CONVECTION OVER THE EASTERN COUNTIES, WHICH APPEARS REASONABLE AND IS CONSISTENT WITH CURRENT TRENDS. FOR FORECAST UPDATE THIS MORNING, INCREASED POPS TO 50 PERCENT OVER COLLIER AND HENDRY COUNTIES TO ACC0UNT FOR CURRENT AREA OF PRECIP WHICH SHOULD DECREASE THIS AFTERNOON. INCREASED CLOUD COVER WESTERN AREAS TODAY SHOULD KEEP TEMPS FROM REACHING MID 80S, THEREFORE LOWERED MAX TEMPS A FEW DEGREES THESE AREAS. ELSEWHERE, LITTLE CHANGE AS ENOUGH HEATING SHOULD ENABLE TEMPS TO REACH FORECAST VALUE OF MID 80S METRO AREAS BROWARD AND MIAMI-DADE, SLIGHTLY COOLER PALM BEACHES WHERE CLOUDS SHOULD ARRIVE SOONER. POPS FOR EASTERN AREAS LOOK GOOD. OVER THE LOCAL WATERS, CURRENT WINDS AND SEAS LOOK GOOD AND NO CHANGES ANTICIPATED. /MOLLEDA && .PREV DISCUSSION... /ISSUED 721 AM EDT SUN MAR 25 2012/ AVIATION... FRONTAL BOUNDARY MOVING SLOWLY SOUTHWARD ACROSS THE FLORIDA PENINSULA. SW FLOW EXPECTED AT ALL TERMINALS THROUGH THE PERIOD AS THE BOUNDARY APPROACHES. CURRENT GUIDANCE DID NOT CHANGE MUCH FROM PREVIOUS RUNS THEREFORE...KEPT VCSH AT ALL TERMINALS TO BEGIN AT 25/13-14Z...ALONG WITH GUSTY WINDS. MOSTLY CLEAR SKIES AND LIGHTER WINDS ARE EXPECTED BY 26/00Z. PREV DISCUSSION... /ISSUED 402 AM EDT SUN MAR 25 2012/ DISCUSSION... CUTOFF UPPER LEVEL LOW SPINNING OVER THE SOUTHEAST...WITH SURFACE COLD FRONT MOVING THROUGH NORTH CENTRAL FLORIDA THIS MORNING. SHOWERS AND ISOLATED THUNDERSTORMS WERE ACROSS THE EASTERN GULF MOVING TOWARDS CENTRAL FLORIDA. THE UPPER LEVEL LOW WILL CONTINUE TO SLIDE TO THE EAST TODAY...AND MOVE INTO THE ATLANTIC BY THIS EVENING. WEST TO SOUTHWEST FLOW WILL CONTINUE ACROSS THE REGION AHEAD OF THE FRONT. MODELS CONTINUE TO SHOW DESTABILIZING CONDITIONS THROUGH THE AFTERNOON. 500MB TEMPS ARE AROUND -12C...LOW LEVEL LAPSE RATES ARE STEEP AND EVEN SLIGHT DAYTIME HEATING IS EXPECTED TO BRING TEMPERATURES INTO THE LOW TO MID 80S. THIS SHOULD ALLOW AT LEAST ISOLATED THUNDERSTORMS TO DEVELOP AHEAD OF AND ALONG THE FRONT. SO EXPANDED THE THUNDERSTORM AREA TO MOST OF THE REGION ALONG AND AHEAD OF THE FRONT. HRRR SHOWS SCATTERED SHOWERS AND SOME THUNDERSTORMS DEVELOPING ACROSS THE EASTERN HALF OF THE REGION BY 18Z. THIS FOLLOWS WITH OTHER MODEL SOLUTIONS...SO EXPECT THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE EAST FROM NORTHERN MIAMI-DADE COUNTY NORTHWARD THIS AFTERNOON. MID LEVEL LAPSE RATES ARE NOT IMPRESSIVE...MOIST ADIABATIC ABOVE 700-800MB...SO LEFT MENTION OF HAIL OUT. THE FRONT IS EXPECTED TO MAKE ITS WAY TOWARDS THE LAKE REGION AROUND 18Z WITH PRECIPITATION ENDING THERE BY 21Z. THE FRONT SHOULD MOVE OFF THE FLORIDA PENINSULA AROUND 00Z...WITH ANY LEFTOVER SHOWERS ACROSS THE SOUTH ENDING BY EARLY EVENING. A DRY NORTHWEST FLOW IS EXPECTED BEHIND THE FRONT...WHICH WILL BRING COOLER CONDITIONS TONIGHT TO THE REGION. OVERNIGHT LOWS ARE EXPECTED TO DROP INTO THE 50S NORTHWEST TO THE LOW TO MID 60S ACROSS THE SOUTHEAST ATLANTIC COAST. SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OUT OF CANADA AND TOWARDS THE MID ATLANTIC STATES ON MONDAY...AND WINDS WILL SHIFT FROM THE NORTHWEST TO THE NORTHEAST BY TUESDAY MORNING. MODELS CONTINUE TO SHOW A WEAK INVERTED TROUGH MOVING ACROSS SOUTH FLORIDA ON TUESDAY...BRINGING A MOISTURE AND WIND SURGE TO THE REGION. SO BREEZY CONDITIONS ARE EXPECTED ACROSS SOUTH FLORIDA ON TUESDAY...WITH ISOLATED SHOWERS ACROSS THE EASTERN HALF OF THE REGION. MODELS THEN SHOW DRIER AIR MOVING BACK INTO THE REGION THROUGH THE END OF THE WEEK. HOWEVER...HIGH PRESSURE IS STILL EXPECTED TO BE NORTHEAST OF THE REGION THROUGH WEDNESDAY...SO THERE WILL STILL BE A CHANCE FOR A PASSING LIGHT SHOWER ACROSS THE EAST COAST METRO AREAS. SO LEFT THE 10 POPS WITH MENTION OF PRECIP THROUGH THE DAY ON WEDNESDAY. HIGH PRESSURE WILL WEAKEN AND SHIFT EAST ON THURSDAY AS A SHORTWAVE TROUGH PUSHES INTO THE MID ATLANTIC STATES. SO LIGHT WINDS AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK. TEMPERATURES WILL REMAIN WARM...WITH HIGHS IN THE LOW TO MID 80S AND LOWS AROUND 60 TO AROUND 70. AVIATION... FRONTAL BOUNDARY MOVING SLOWLY SOUTHWARD ACROSS THE FLORIDA PENINSULA. SW FLOW EXPECTED AT ALL TERMINALS THROUGH THE PERIOD AS THE BOUNDARY APPROACHES. CURRENT GUIDANCE DID NOT CHANGE MUCH FROM PREVIOUS RUNS THEREFORE...KEPT VCSH AT ALL TERMINALS TO BEGIN AT 25/16Z...ALONG WITH GUSTY WINDS. MOSTLY CLEAR SKIES AND LIGHTER WINDS ARE EXPECTED BY 26/00Z. MARINE... SOUTHWEST WINDS ARE EXPECTED AHEAD OF A COLD FRONT TODAY...WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE BOUNDARY. WINDS WILL SHIFT TO THE NORTHWEST ACROSS THE LOCAL WATERS THIS AFTERNOON THROUGH THE EVENING AS THE COLD FRONT MOVES THROUGH. BY LATE MONDAY...WINDS WILL BECOME EASTERLY AGAIN AS HIGH PRESSURE BUILDS ACROSS THE ATLANTIC. CURRENT GUIDANCE STILL SHOWING A WEAK INVERTED TROUGH MOVING INTO THE LOCAL ATLANTIC WATERS ON TUESDAY. THIS WILL INCREASE THE WINDS ACROSS THE ATLANTIC WATERS WITH SCEC AND POSSIBLY A SHORT PERIOD OF SCA CONDITIONS IN WEDNESDAY MORNING. FIRE WEATHER... NO FIRE WEATHER CONCERNS TODAY AS A COLD FRONT MOVES THROUGH THE REGION. ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG THE FRONT. RELATIVE HUMIDITY VALUES MAY DROP TO AROUND 35 PERCENT ACROSS A LARGE PORTION OF THE REGION MONDAY AFTERNOON AS DRIER AIR MOVES DOWN THE PENINSULA BEHIND THE FRONT. WINDS SHIFT TO THE EAST MONDAY NIGHT...WITH LOW LEVEL MOISTURE RETURNING TO THE AREA. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 83 63 81 66 / 50 10 0 - FORT LAUDERDALE 86 66 83 68 / 40 20 0 - MIAMI 87 65 83 66 / 40 20 0 - NAPLES 79 64 83 63 / 50 10 0 - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ PUBLIC/MARINE...59/MOLLEDA AVIATION/FIRE/RADAR...71/JE
AREA FORECAST DISCUSSION
NWS MIAMI FL
721 AM EDT SUN MAR 25 2012 .AVIATION... FRONTAL BOUNDARY MOVING SLOWLY SOUTHWARD ACROSS THE FLORIDA PENINSULA. SW FLOW EXPECTED AT ALL TERMINALS THROUGH THE PERIOD AS THE BOUNDARY APPROACHES. CURRENT GUIDANCE DID NOT CHANGE MUCH FROM PREVIOUS RUNS THEREFORE...KEPT VCSH AT ALL TERMINALS TO BEGIN AT 25/13-14Z...ALONG WITH GUSTY WINDS. MOSTLY CLEAR SKIES AND LIGHTER WINDS ARE EXPECTED BY 26/00Z. && .PREV DISCUSSION... /ISSUED 402 AM EDT SUN MAR 25 2012/ DISCUSSION... CUTOFF UPPER LEVEL LOW SPINNING OVER THE SOUTHEAST...WITH SURFACE COLD FRONT MOVING THROUGH NORTH CENTRAL FLORIDA THIS MORNING. SHOWERS AND ISOLATED THUNDERSTORMS WERE ACROSS THE EASTERN GULF MOVING TOWARDS CENTRAL FLORIDA. THE UPPER LEVEL LOW WILL CONTINUE TO SLIDE TO THE EAST TODAY...AND MOVE INTO THE ATLANTIC BY THIS EVENING. WEST TO SOUTHWEST FLOW WILL CONTINUE ACROSS THE REGION AHEAD OF THE FRONT. MODELS CONTINUE TO SHOW DESTABILIZING CONDITIONS THROUGH THE AFTERNOON. 500MB TEMPS ARE AROUND -12C...LOW LEVEL LAPSE RATES ARE STEEP AND EVEN SLIGHT DAYTIME HEATING IS EXPECTED TO BRING TEMPERATURES INTO THE LOW TO MID 80S. THIS SHOULD ALLOW AT LEAST ISOLATED THUNDERSTORMS TO DEVELOP AHEAD OF AND ALONG THE FRONT. SO EXPANDED THE THUNDERSTORM AREA TO MOST OF THE REGION ALONG AND AHEAD OF THE FRONT. HRRR SHOWS SCATTERED SHOWERS AND SOME THUNDERSTORMS DEVELOPING ACROSS THE EASTERN HALF OF THE REGION BY 18Z. THIS FOLLOWS WITH OTHER MODEL SOLUTIONS...SO EXPECT THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE EAST FROM NORTHERN MIAMI-DADE COUNTY NORTHWARD THIS AFTERNOON. MID LEVEL LAPSE RATES ARE NOT IMPRESSIVE...MOIST ADIABATIC ABOVE 700-800MB...SO LEFT MENTION OF HAIL OUT. THE FRONT IS EXPECTED TO MAKE ITS WAY TOWARDS THE LAKE REGION AROUND 18Z WITH PRECIPITATION ENDING THERE BY 21Z. THE FRONT SHOULD MOVE OFF THE FLORIDA PENINSULA AROUND 00Z...WITH ANY LEFTOVER SHOWERS ACROSS THE SOUTH ENDING BY EARLY EVENING. A DRY NORTHWEST FLOW IS EXPECTED BEHIND THE FRONT...WHICH WILL BRING COOLER CONDITIONS TONIGHT TO THE REGION. OVERNIGHT LOWS ARE EXPECTED TO DROP INTO THE 50S NORTHWEST TO THE LOW TO MID 60S ACROSS THE SOUTHEAST ATLANTIC COAST. SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OUT OF CANADA AND TOWARDS THE MID ATLANTIC STATES ON MONDAY...AND WINDS WILL SHIFT FROM THE NORTHWEST TO THE NORTHEAST BY TUESDAY MORNING. MODELS CONTINUE TO SHOW A WEAK INVERTED TROUGH MOVING ACROSS SOUTH FLORIDA ON TUESDAY...BRINGING A MOISTURE AND WIND SURGE TO THE REGION. SO BREEZY CONDITIONS ARE EXPECTED ACROSS SOUTH FLORIDA ON TUESDAY...WITH ISOLATED SHOWERS ACROSS THE EASTERN HALF OF THE REGION. MODELS THEN SHOW DRIER AIR MOVING BACK INTO THE REGION THROUGH THE END OF THE WEEK. HOWEVER...HIGH PRESSURE IS STILL EXPECTED TO BE NORTHEAST OF THE REGION THROUGH WEDNESDAY...SO THERE WILL STILL BE A CHANCE FOR A PASSING LIGHT SHOWER ACROSS THE EAST COAST METRO AREAS. SO LEFT THE 10 POPS WITH MENTION OF PRECIP THROUGH THE DAY ON WEDNESDAY. HIGH PRESSURE WILL WEAKEN AND SHIFT EAST ON THURSDAY AS A SHORTWAVE TROUGH PUSHES INTO THE MID ATLANTIC STATES. SO LIGHT WINDS AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK. TEMPERATURES WILL REMAIN WARM...WITH HIGHS IN THE LOW TO MID 80S AND LOWS AROUND 60 TO AROUND 70. AVIATION... FRONTAL BOUNDARY MOVING SLOWLY SOUTHWARD ACROSS THE FLORIDA PENINSULA. SW FLOW EXPECTED AT ALL TERMINALS THROUGH THE PERIOD AS THE BOUNDARY APPROACHES. CURRENT GUIDANCE DID NOT CHANGE MUCH FROM PREVIOUS RUNS THEREFORE...KEPT VCSH AT ALL TERMINALS TO BEGIN AT 25/16Z...ALONG WITH GUSTY WINDS. MOSTLY CLEAR SKIES AND LIGHTER WINDS ARE EXPECTED BY 26/00Z. MARINE... SOUTHWEST WINDS ARE EXPECTED AHEAD OF A COLD FRONT TODAY...WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE BOUNDARY. WINDS WILL SHIFT TO THE NORTHWEST ACROSS THE LOCAL WATERS THIS AFTERNOON THROUGH THE EVENING AS THE COLD FRONT MOVES THROUGH. BY LATE MONDAY...WINDS WILL BECOME EASTERLY AGAIN AS HIGH PRESSURE BUILDS ACROSS THE ATLANTIC. CURRENT GUIDANCE STILL SHOWING A WEAK INVERTED TROUGH MOVING INTO THE LOCAL ATLANTIC WATERS ON TUESDAY. THIS WILL INCREASE THE WINDS ACROSS THE ATLANTIC WATERS WITH SCEC AND POSSIBLY A SHORT PERIOD OF SCA CONDITIONS IN WEDNESDAY MORNING. FIRE WEATHER... NO FIRE WEATHER CONCERNS TODAY AS A COLD FRONT MOVES THROUGH THE REGION. ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG THE FRONT. RELATIVE HUMIDITY VALUES MAY DROP TO AROUND 35 PERCENT ACROSS A LARGE PORTION OF THE REGION MONDAY AFTERNOON AS DRIER AIR MOVES DOWN THE PENINSULA BEHIND THE FRONT. WINDS SHIFT TO THE EAST MONDAY NIGHT...WITH LOW LEVEL MOISTURE RETURNING TO THE AREA. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 84 63 81 66 / 50 10 0 - FORT LAUDERDALE 85 66 83 68 / 40 20 0 - MIAMI 85 65 83 66 / 40 20 0 - NAPLES 82 64 83 63 / 30 10 0 - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...59/RM AVIATION/RADAR...71/JE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
724 AM CDT SUN MAR 25 2012 .UPDATE... UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW. && .DISCUSSION... MANY DIFFERENT CONCERNS WITH THE FORECAST OVER THE NEXT FEW DAYS. INITIALLY RATHER QUIET WITH SURFACE HIGH DROPPING ACROSS THE WESTERN GREAT LAKES REGION TODAY AND TODAY. COLD AIR IS CURRENTLY INVADING THE AREA WITH SOME COLD ADVECTION STRATUS WORKING ITS WAS SOUTH OVER THE AREA. STILL A QUESTION HOW FAR SOUTH IT WILL MAKE IT BEFORE SUNRISE. SOME BREAKS NOTED OVER NORTHWEST MINNESOTA ALREADY SO DO EXPECT CLEARING TO TAKE HOLD LATE MORNING/AFTERNOON. SOME HIGH OR MID LEVEL CLOUDS EXPECTED TO MOVE INTO THE WESTERN AREAS DURING THE AFTERNOON AS WELL. MUCH COOLER TODAY WITH READINGS REMAIN IN THE 50S FOR MUCH OF THE FORECAST AREA. NEXT WEATHER MAKER JUST COMING ASHORE TO THE SOUTHWEST. SOME ENERGY FROM THE TROUGH RIDING UP ACROSS THE CENTRAL ROCKIES TO THE WESTERN DAKOTAS. APPEARS TROUGH IS PROGRESSIVE WITH THE NEXT KICKER WAVE DROPPING SOUTHEAST SOUTH OF THE THE GULF OF ALASKA REGION. EXPECT CLOUDS TO THICKEN OVERNIGHT...AS MID LEVEL FRONTOGENESIS/WAA PATTERN DEVELOPS ON THE BACKSIDE OF THE HIGH. WILL START OUT VERY DRY...ESPECIALLY OVER EASTERN AREAS. LIMITED ANY SHOWER THREAT TO MAINLY MN OVERNIGHT...AND THAT IS ALSO DOUBTFUL. WILL START OUT AS VIRGA...AND POSSIBLY SATURATING LATER TONIGHT. MODELS HAVE BEEN ALL OVER THE PLACE WHERE PLACEMENT OF THIS LIGHT QPF WILL BE. 00Z ECMWF DROPPED IT FARTHER SOUTH AND NOW THE 06Z NAM DROPS IT ALONG THE MINNESOTA RIVER VALLEY. WILL ADJUST POP A BIT BUT WILL MAINTAIN SMALL CHANCE. THUNDER THREAT LOOKS MARGINAL AT BEST INTO MONDAY. MAIN INSTABILITY AND BEST FORCING REMAINS OVER THE DAKOTAS INTO THE AFTERNOON. SOME WEAK INSTABILITY WITH BEST LI`S GENERALLY AROUND ZERO...SLIGHTLY BELOW BY 12Z MONDAY OVER THE SOUTHWEST. LATEST NAM GENERATES EVEN WEAKER MID LEVEL/ELEVATED CAPE AS THIS FGEN SURGE MOVES THROUGH MONDAY. WILL KEEP THE THUNDER THREAT ISOLATED OVER THE WESTERN PORTION OF THE FORECAST AREA THROUGH MONDAY. HIGH TEMPERATURES WILL STRUGGLE TO WARM THROUGH THE 50S ON MONDAY WITH CLOUD...EAST WIND. MAIN ENERGY LIFTS NORTHEAST ACROSS THE DAKOTAS AND NORTHWEST MINNESOTA MONDAY NIGHT INTO TUESDAY. PV ANOMALY MOVES MAINLY OVER THE EASTERN DAKOTAS INTO WESTERN CENTRAL MN TUESDAY MORNING. WILL HAVE TO MONITOR THIS REGION FOR VERY STRONG WINDS POSSIBLY 50KT GUSTS WITH FRONT AS IT MOVES THROUGH. IT APPEARS COLD FRONT WILL HAVE SWEPT INTO CENTRAL MN BY 12Z TUE AND WILL EXIT INTO WISCONSIN IN THE AFTERNOON. WARM SECTOR IS EVIDENT WITH SOME INSTABILITY...BUT TIMING NOT GOOD AND SYSTEM IS MOVING FAST. WILL CONTINUE LIKELY POPS TO THE NORTHEAST WITH JUST CHANCE POPS ELSEWHERE...TRAILING OFF OVER THE EAST ON TUESDAY. DRY SURGE MOVES IN BEHIND THE FRONT...AND SURFACE DEWPOINTS WILL DROP OFF AGAIN. WIND ADVISORY WILL BE LIKELY OVER THE WESTERN AND SOUTH TUESDAY...AND HUMIDITY`S WILL DROP OFF TO PERHAPS 25 PERCENT BY LATE AFTERNOON...RAISING FIRE WEATHER CONCERNS. THIS SYSTEM EXITS THE AREA TUESDAY NIGHT PROVIDING A DRY AND COOL TREND INTO WEDNESDAY NIGHT. NEXT FRONT TO AFFECT THE AREA LATER THURSDAY INTO FRIDAY WITH SOME CHANCE POPS. SEVERE POTENTIAL APPEARS LIMITED WITH THIS AS WELL. UPPER AIR PATTERN DOES APPEAR TO TREND TO ANOTHER LONG WAVE TROUGH DEVELOPING OVER THE WESTERN CONUS BY NEXT WEEKEND. THIS SHOULD PROVIDE WARMER TEMPERATURES AND AN INCREASING RISK OF THUNDER INTO THE WEEKEND. && .AVIATION.../12Z TAF ISSUANCE/ SWATH OF LOW STRATUS HAS SMOTHERED MUCH OF MN AND WRN WI THIS MRNG BEHIND THE CDFNT...WHICH IS NOW FROM KMKX TO THE IA/MO BORDER. THE FNT WILL STALL OUT THEREABOUTS THRU MON. THE ISSUE FOR TDA IS HOW LONG UNTIL THE LOW CLOUDS BREAK UP TO ALLOW PARTIAL SUNSHINE. MODELS HAVE HAD A DIFFICULT TIME WITH THE STRATUS THIS MRNG...BUT THE HRRR SEEMS TO HAVE HAD THE BEST HANDLE SO USING ITS DEPICTIONS...THE LOW STRATUS WILL LINGER UNTIL THE 16Z-18Z RANGE. ALSO DIFFICULT TO TELL IF SITES THAT ARE OVC010-012 WILL DROP TO IFR. HAVE KEPT THOSE SITES THAT HAVE DROPPED TO LOWER MVFR IN MVFR...WHILE KEEPING THOSE REPORTING IFR IN IFR...OPTING NOT TO HAVE BOUNCING OF CATEGORIES WITH LOW LEVEL MOISTURE DIFFICULT TO RECOVER IN A LOW-LEVEL MIXED ENVIRONMENT. AROUND NOON...ADDITIONAL DRY AIR PLUS DEEPER MIXING SHOULD ERODE THE LOWER CLOUDS SUCH THAT SCATTERED LOW CLOUDS WILL REMAIN THROUGH LATE AFTN. ATTENTION THEN TURNS TO THE INCOMING SYSTEM FOR MONDAY. CLOUDS WILL STREAM IN AHEAD OF IT...FIRST AT HIGH LEVELS THEN GRADUALLY LOWERING WITH TIME. THERE IS A LOW CHANCE OF SOME RAIN SHOWERS REACHING THE WESTERN SITES BY 12Z...BUT WITH WEAK MODEL CONFIDENCE DUE TO MEAGER LOW-LEVEL MOISTURE PLAYING A KEY FACTOR...AM HESITANT TO INCLUDE ANY PRECIP AT THIS POINT. NORTHERLY WINDS TODAY WILL BECOME MORE EASTERLY TONIGHT AS HIGH PRESSURE TO THE NORTH SLIDES EAST. MSP...INITIALIZED WITH BKN011 AS A WIDE SWATH OF LOW CLOUDS HAS SHIFTED SOUTH ENOUGH TO MOVE ACRS KMSP. DEBATED HOW LOW TO GO WITH CLOUDS CONSIDERING ALL SITES W OF KFCM AND KANE ARE AT IFR...BUT AFTER COLLAB WITH CWSU ZMP HAVE KEPT THINGS AT LOW MVFR LEVELS. CONFIDENCE HIGH THAT CIGS WILL LINGER BELOW 1700FT THRU MIDDAY BUT CANNOT RULE OUT THAT CIGS MAY BRIEFLY DROP BELOW 1000FT BEFORE BREAKING UP. LOW-LEVEL SCATTERED CLOUDS WILL THEN PREVAIL THRU MUCH OF THE AFTN BEFORE ALLOWING HIGHER CLOUDS TO BECOME DOMINANT. HIGH CLOUDS WILL THEN INCREASE IN COVERAGE AND LOWER TNGT THRU TMRW AS A POTENT STORM SYSTEM DEVELOPING OVER THE NRN ROCKIES SHIFTS INTO THE DAKOTAS. LOW PRECIP CHCS AND MODEL UNCERTAINTY OVERCOMING THE LOW-LEVEL DRY AIR TO PRODUCE PRECIP MAKES FOR NOT INCLUDING PRECIP IN THIS TAF...EVEN IN THE 12Z-18Z PERIOD TMRW. THOUGHT ABOUT INCLUDING CB MENTION SINCE THERE ARE SOME INDICATIONS OF CONVECTION ALOFT...BUT WOULD RATHER WAIT FOR LATER MODEL RUNS TO HELP CLEAR UP THE PICTURE. OUTLOOK... /MON-TUE/...STRONG ORGANIZED STORM SYSTEM WILL BRING SHWRS/TSTMS MAINLY MON NIGHT THRU TUE. PERIODS OF MVFR-IFR CONDITIONS...ALONG WITH BREEZY CONDITIONS. /WED/...VFR WITH CONTINUED BREEZY CONDITIONS. /THU/...WEAK SYSTEM TO BRING SCATTERED SHWRS/TSTMS...POSSIBLE MVFR CONDITIONS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JPC
AREA FORECAST DISCUSSION
NWS GLASGOW MT
904 AM MDT SUN MAR 25 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH TUESDAY... MORNING UPDATE... MOST THINGS FOR TODAY LOOK GOOD. DID SOME MANIPULATION OF THE WIND FIELDS TO INCLUDE MOST RECENT HRRR DATA. THIS SEEMS TO BRING DOWN OVER ALL WIND SPEEDS EXCEPT FOR HILL TOPS AND MICROSCALE DOWNSLOPE EFFECTS. CLOUD COVER WAS ALSO TWEAKED TO ADD THE LIMITED LOW STRATUS THIS MORNING ACROSS THE EASTERN SIDE OF THE YELLOWSTONE VALLEY... MOST OF WHICH WILL BURN OFF BY THE AFTERNOON HOURS. ALSO TWEAKED SKY COVER GRIDS TO GIVE A BETTER INTERPRETATION OF THE THIN STRATO-CIRRUS DECK THAT WILL ENCOMPASS MOST OF THE CWA OTHER THAN THE NORTH. GAH PREVIOUS SHORT TERM DISCUSSION... TWO MAIN IMPACTS TO THINK ABOUT IN THE SHORT TERM FOR MONDAY ARE FIRE WEATHER CONCERNS ACROSS FIRE WEATHER ZONE 122 MONDAY AFTERNOON AND EVENING AND THE STRONG WINDS BEHIND A COLD FRONT THAT WILL MOVE THROUGH LATE MONDAY EVENING. AN UPPER LEVEL RIDGE THAT SITS OVER EASTERN MONTANA WILL CONTROL THE WEATHER OVER THE NEXT 24 HOURS. A UPPER LOW/TROUGH COMBO OFF THE OREGON AND CALIFORNIA COAST IS POISED TO BE EJECTED OVER THE SIERRA NEVADA MOUNTAIN AND ACROSS THE GREAT BASIN BY ANOTHER UPPER LOW MOVING OUT OF THE GULF OF ALASKA. THE UPPER LOW WILL MOVE ACROSS WYOMING AS A NEGATIVELY TILTED TROUGH AND DRAG A DEVELOPING COLD FRONT ACROSS EASTERN MONTANA. SUNDAY THROUGH SUNDAY NIGHT... THE SOUTHWEST FLOW ALOFT OVER THE INTER MOUNTAIN WEST WILL HELP WARM THINGS UP THIS AFTERNOON. THE WINDS WILL BE OUT OF THE EAST AROUND 15 TO 25 MPH. IT WILL BE CLOSE TO LAKE WIND ADVISORY CONDITIONS BUT WILL LET THE MORNING SHIFT TAKE ANOTHER LOOK. THE MET AND MAV GUIDANCE SEEMS A LITTLE TO STRONG FOR THIS AFTERNOON. MONDAY AFTERNOON CONDITIONS WILL BECOME DRY ACROSS ZONE 122 SO WE HAVE ISSUED A FIRE WEATHER WATCH FOR THE ABOVE NORMAL TEMPERATURES...BREEZY WINDS AND DRY FUELS. AS THE NEGATIVELY TITLED TROUGH APPROACHES EASTERN MONTANA WITH ITS COLD FRONT LEADING THE WAY IT WILL ENCOUNTER CAPE BETWEEN 450 AND 1000 J/KG AND LI`S DOWN TO -4*C. THE STRONGEST CAPE SIGNATURE WILL BE OVER THE YELLOWSTONE VALLEY SO THIS IS THE AREA THAT WILL HAVE THE BEST CHANCE FOR STRONG THUNDERSTORMS. SMALL HAIL ALONG WITH LIGHTNING WILL BE THE BIGGEST THREAT. OTHER AREAS COULD SEE A FEW SCATTERED WEAKER THUNDERSTORMS AS WELL. THE SYSTEM WILL MOVE OVER NORTH DAKOTA AND IT WILL BECOME VERTICALLY STACKED. AS IT WRAPS UP IT WILL PULL MUCH COLDER AIR ACROSS EASTERN MONTANA FROM ALBERTA. WINDS WILL INCREASE BEHIND THE FRONT MONDAY NIGHT INTO TUESDAY MORNING IN THE 30 TO 40 MPH RANGE WITH GUSTS OVER 50 MPH LIKELY OVER THE YELLOWSTONE VALLEY. GOOD OMEGA VALUES PULLING THE STRONG 50 TO 65 KNOT WINDS TO THE SURFACE AFTER MIDNIGHT FROM THE 850 TO 700 MB LEVEL ON A NAM TIME SERIES IN WESTERN PRAIRIE COUNTY. DECIDED TO HOLD OFF ON A HIGH WIND WATCH FOR NOW SINCE WE ALREADY HAVE ANOTHER HIGHLIGHT FOR THE SAME GENERAL AREA WITH THE FIRE WEATHER WATCH. TUESDAY THE SYSTEM SHIFTS EAST AND THERE COULD BE A BRIEF CHANGE OVER TO A RAIN SNOW MIX ACROSS THE FAR NORTHEAST ZONES OF DANIELS AND SHERIDAN COUNTIES. ONE GROUP THAT WILL BE SEVERALLY IMPACTED WITH THIS SYSTEM ACROSS ALL OF EASTERN MONTANA IS THE YOUNG LIVESTOCK. WE HAVE STRONG WINDS...COLD AND RAINY WEATHER WHICH IS NOT A GOOD COMBINATION FOR NEWLY BORN LIVESTOCK. RSMITH .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY... THE EXTENDED BEINGS WITH A SHORT WAVE RIDGE IN PLACE OVER MONTANA. THE GFS AND EC ARE IN GOOD AGREEMENT ON THIS FEATURE. THE RIDGE MIGRATES TO THE EAST PUTTING MONTANA IN SOUTHWEST FLOW ALOFT. FROM DAY 5 AND BEYOND THE EC AND GFS HAVE DIFFERENT TIMING AND POSITIONING OF FEATURES MOVING THROUGH THE UPPER FLOW PATTERN. CONFIDENCE IS LOW IN PINNING DOWN THE EVENTS THIS WEEK WITH THE MODEL DIFFERENCES ON TIMING... HOWEVER THE OVERALL PATTERN IS WESTERLY TO SOUTHWESTERLY WITH CHANCES OF WEAK CONVECTION WITH STRONGER SHORTWAVES AND FRONTS. OVERALL NOT ANY BIG TEMPERATURE SWINGS ARE EXPECTED THROUGH THE PERIOD. FOR THE SOLUTION IN THE EXTENDED LEANED ON A HEAVY EC CONSALL BLEND FOR FORECAST ELEMENTS WHICH KEPT WITH THE CURRENT FORECAST TREND. PROTON && .AVIATION... VFR. THE MAIN ISSUE WILL BE EAST WINDS KICKING EARLY THIS MORNING AND LASTING THROUGH THE NEXT 24 HOURS. THE STRONGEST WINDS WILL BE ALONG THE MILK RIVER VALLEY AND HIGHER ELEVATIONS. RIVER BOTTOM AIRPORTS COULD HAVE MINOR LLWS ISSUES IN THE AFTERNOON. PROTON && .GLASGOW WATCHES/WARNINGS/ADVISORIES... LAKE WIND ADVISORY UNTIL 3 PM MDT MONDAY FOR FORT PECK LAKE. FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR MTZ122. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
626 AM CDT SUN MAR 25 2012 .DISCUSSION... ARCTIC AIR CONTINUES TO BACK IN ACROSS NCNTL NEB THIS MORNING PRODUCING A SHALLOW DECK OF STRATUS. WINDS STAY EAST MOST OF THE DAY BENEATH THE DECK. WORSE THE RUC SHOWS PWAT POOLING BEHIND THE FRONT ALONG THE SD BORDER WHICH CANT BE A GOOD WAY TO ERODE STRATUS. SO 1ST PERIOD HIGH TEMPS HAVE BEEN MARKED DOWN USING THE RUC13 AS A GUIDE. && .AVIATION... THE RUC SUGGESTED THE STRATUS WILL DISSIPATE BETWEEN 18Z AND 21Z. SO LIFR/IFR SHOULD GRADUALLY ERODE THIS MORNING BECOMING IFR/MVFR EARLY THIS AFTN AND THEN VFR BY 21Z. VFR IS EXPECTED THEREAFTER. ISOLATED THUNDERSTORMS MAY DEVELOP LATE THIS AFTN AND OVERNIGHT ALONG AND NORTH OF HIGHWAY 20. ELSEWHERE VFR TODAY AND TONIGHT. && .PREV DISCUSSION... /ISSUED 351 AM CDT SUN MAR 25 2012/ SYNOPSIS... HAND ANALYSIS OF THE H5 CHART REVEALS THAT SHORTWAVE RIDGING HAS BECOME FULLY ESTABLISHED ACROSS THE CENTRAL STATES...WITH A TROUGH OF LOW PRESSURE DIGGING SOUTH OFF CENTRAL CALIFORNIA. A SECOND AREA OF LOW PRESSURE RESIDES EAST OF THE CENTRAL MISSISSIPPI RIVER VALLEY AND CONTINUES TO PUSH SOUTHEAST TOWARD THE COAST OF SOUTH CAROLINA. THIS PATTERN PRESENTS GENERAL SOUTHWEST FLOW ALOFT ACROSS WESTERN NEBRASKA WITH THE RIDGE AXIS BISECTING THE FORECAST AREA. AT THE SURFACE...WIND SPEEDS ARE GENERALLY LIGHT AND FROM THE NORTHEAST ACROSS WEST CENTRAL NEBRASKA WITH AN AREA OF HIGH PRESSURE CENTERED NORTH OF THE US/CANADIAN BORDER. FURTHER WEST OVER THE HIGHER TERRAIN OF EASTERN WYOMING/COLORADO...THE WIND IS BEGINNING TO VEER SLIGHTLY TO THE SOUTHEAST...AS A BROAD AREA OF LOW PRESSURE BEGINS TO DEEPEN. DISCUSSION... THROUGH 12Z MONDAY. SURFACE HIGH PRESSURE OVER CANADA WILL BUILD EAST THROUGH THE DAY TODAY AS WEST COAST UPPER TROUGH ROTATES INLAND AND TAKES ON A STRONG NEGATIVE TILT. SURFACE LOW PRESSURE OVER THE ROCKIES WILL CONTINUE TO DEEPEN AND THUS STRENGTHEN SOUTHERLY RETURN FLOW BACK ACROSS ALL OF WESTERN AND NORTH CENTRAL NEBRASKA. MODEL GUIDANCE INDICATES INCREASING ATMOSPHERIC MOISTURE WITH THE SOUTHERLY FLOW AS SURFACE TD/S RETURN ABOVE 45F FOR MOST IF NOT ALL LOCATIONS ACROSS THE CWA. THIS SHOULD HELP DECREASE THE FIRE POTENTIAL THIS AFTERNOON AS SURFACE T/S REMAIN IN THE 70/S TO LOW 80/S ALLOWING FOR EXPECTED RH VALUES WELL ABOVE RED FLAG MINIMUM CRITERIA. WITH THE INCREASING MOISTURE...STORM CHANCES ARE A POSSIBILITY LATE THIS AFTERNOON AND TONIGHT /FOR LOCATIONS MAINLY NORTH OF HIGHWAY TWO ACROSS NORTHWEST NEBRASKA/. A WARM FRONT WILL CONTINUE TO LIFT NORTHWARD THROUGH THE AFTERNOON...STALLING ALONG OR NEAR THE SOUTH DAKOTA BORDER BY 00Z MONDAY. SYNOPTIC LIFT WILL BE ON THE INCREASE AS THETA-E ADVECTION OCCURS AND IS MAXIMIZED ACROSS NORTHWEST NEBRASKA. MIDLEVEL LAPSE RATES WILL BE STEEP...HOWEVER THERE IS QUESTION AS TO IF STORMS ARE ABLE TO BREACH THE CAPPING INVERSION AS STRONG RIDGING REMAINS ENTRENCHED OVER THE CENTRAL AND NORTHERN PLAINS. IF SO...THE STORMS WOULD BE ABLE TO WORK ON MODEST INSTABILITY OF 500-1000 J/KG OF CAPE AND 0-6KM BULK SHEAR OF 45KTS. STORMS WOULD HAVE THE POTENTIAL TO PRODUCE SEVERE HAIL AND CERTAINLY SEVERE WIND GUSTS AS A SOMEWHAT INVERTED V PROFILE IS SHOWN IN BUFR SOUNDINGS. GOING INTO THE EVENING...A LOW LEVEL JET WILL STRENGTHEN AND PROVIDE A FURTHER FOCUS OF STORM DEVELOPMENT ACROSS NORTHERN AND NORTH CENTRAL NEBRASKA OVERNIGHT...WILL CONTINUE THE MENTION OF ELEVATED SHOWERS/THUNDERSTORMS. SEVERAL CONCERNS IN THE FORECAST FOR MONDAY AS A PLETHORA OF WEATHER IS EXPECTED. FIRST...WILL ISSUE A FIRE WEATHER WATCH FOR FIRE ZONES 204 AND 210 WITH THIS MORNING FORECAST PACKAGE. A DRY LINE IS EXPECTED BECOME ESTABLISHED AND PUSH EAST ACROSS THE PANHANDLE INTO WEST CENTRAL NEBRASKA MONDAY AFTERNOON. MODEL GUIDANCE INDICATES TD/S FALLING BELOW 25F WITH THE PASSAGE. GIVEN ABNORMALLY HIGH EXPECTED TEMPERATURES...RH VALUES ACROSS THE EASTERN PANHANDLE WILL FALL BELOW 15 PERCENT /RED FLAG CRITERIA/ BY MIDAFTERNOON ON MONDAY. MEANWHILE A TIGHT SURFACE GRADIENT WILL EXIST ACROSS THE HIGH PLAINS AS SURFACE PRESSURE RAPIDLY FALLS IN ADVANCE OF THE WEST COAST TROUGH. EXPECT SURFACE WIND SPEEDS TO GUST ABOVE 30 MPH FOR MUCH OF THE AFTERNOON MONDAY. SURFACE LOW PRESSURE WILL QUICKLY DEEPEN AND PUSH NORTHEAST INTO EASTERN NORTH DAKOTA ON LATE MONDAY NIGHT...WHICH WILL DRAG A COLD FRONT THROUGH WESTERN NEBRASKA. AGAIN WIND SPEEDS LOOK PROBLEMATIC....AS HEIGHT RISES ON THE ORDER OF 14MB/3HR ARE SUGGESTED BY SHORT TERM SOLUTIONS. A WIND ADVISORY IS EXPECTED...IF NOT HIGH WIND HIGHLIGHTS MONDAY AFTERNOON AND NIGHT. THE COLD FRONT IS EXPECTED TO QUICKLY CROSS THE CWA MONDAY EVENING...EVENTUALLY OVERTAKING THE DRYLINE. INITIALLY A STRONG CAPPING INVERSION WILL LIMIT STORM DEVELOPMENT ACROSS MUCH OF THE CWA...HOWEVER AS LOW-LEVEL CONVERGENCE ALONG THE COLD FRONT INCREASES...STORM DEVELOPMENT SHOULD BEGIN. LOOKING AT MODEST CAPE OF 500-1000 J/KG WITH 6KM SHEAR OF GREATER THAN 40KTS WOULD PROVIDE THE OPPORTUNITY FOR SEVERE STORMS WITH HAIL AND AND POSSIBLY DAMAGING WINDS. TUESDAY MAY BE ACTIVE IN TERMS OF FIRE WEATHER AGAIN AS ABNORMALLY DRY AIR WILL REMAIN IN PLACE BEHIND THE DEPARTING SYSTEM. POOR RH RECOVERY WILL AID IN PRIMING AVAILABLE FUELS...AND WITH A GOOD PORTION OF THE FA WELL BELOW 20 PERCENT RH TUESDAY AFTERNOON...FIRE CONCERNS MAY BE REALIZED. A COUPLE FACTORS GOING AGAINST THE FIRE POTENTIAL FOR NOW...ONE IS THAT WIND SPEEDS SHOULD EASE WITH THE RELAXING PRESSURE GRADIENT. AND TWO...EARLY GREEN UP IS OCCURRING...WILL NEED TO CONTACT AREA FMO/S TO DETERMINE FUEL AVAILABILITY. AS FOR TEMPERATURES...WILL TREND THE FORECAST DOWN SLIGHTLY ON TUESDAY WITH THE FRONTAL PASSAGE...YET HIGHS WILL STILL BE ABOVE AVERAGE RANGING FROM THE MID 60S ACROSS NORTHWEST NEBRASKA...TO THE LOW TO MID 70S SOUTH OF I80. BEYOND TUESDAY...A WEAK DISTURBANCE CROSSES THE REGION LATE THURSDAY BRINGING A SLIGHT CHANCE OF POPS BACK ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. OTHERWISE SHORTWAVE RIDGING RETURNS JUST IN TIME FOR THE WEEKEND...WITH ANOTHER TROUGH DIGGING DOWN THE WEST COAST OF NA. WILL KEEP T/S ABOVE AVERAGE THROUGH THE EXTENDED AND GO DRY BEYOND FRIDAY MORNING. AVIATION... VFR IS EXPECTED ALL AREAS AFTER 18Z THROUGH 06Z TONIGHT. A WEAK ARCTIC FRONT DRAPED THROUGH KLBF SHOULD LIFT NORTH TO NEAR THE SD BORDER THIS AFTERNOON. THE FRONT AND AREAS NORTH WILL BE THE FOCUS FOR IFR CIGS AND PATCHY FOG THROUGH AT LEAST 15Z. THE RUC SUGGESTS THERE IS POTENTIAL OF IFR TO LINGER ACROSS NRN NEB THROUGH 18Z DEPENDING ON THE NORTHWARD PROGRESS OF THE FRONT WHICH IS SHOWN BY THE MODEL TO BE NEAR HIGHWAY 20 AT 18Z. THUS IFR VS VFR CONDITIONS NEAR KVTN ARE CONTINGENT ON THE FORMATION OF IFR CIGS. THE LATEST SATELLITE INDICATES A BROAD AREA OF STRATUS FORMING WHICH SHOULD CONTINUE EXPANDING UNTIL 14Z-15Z FOLLOWED BY A GRADUAL NORTHWARD EROSION AND CONTRACTION ASSOCIATED WITH THE FRONT LIFTING NORTH. FIRE WEATHER... STRONG DOUBLE BARREL LOW PRESSURE WILL DEEPEN TO AROUND 990MB ACROSS THE NRN HIGH PLAINS MONDAY AFTERNOON. ALL MODELS ARE DRAWING VERY DRY AIR NORTH INTO THE LOW AND PRODUCING SOUTH WINDS IN EXCESS OF 30 MPH THROUGHOUT WRN NEB AS THE LOW DEEPENS. A POWERFUL PACIFIC COLD FRONT WILL THEN RACE EAST THROUGH WRN NEBRASKA MONDAY EVENING PRODUCING VERY STRONG WEST WIND GUSTS. ISOLATED THUNDERSTORMS AND DRY LIGHTNING MAY DEVELOP ALONG THE DRYLINE AHEAD OF THE COLD FRONT. THE DRYLINE SHOULD BE LOCATED NEAR HIGHWAY 61 MONDAY AFTERNOON. A FIRE WEATHER WATCH WILL BE ISSUED THROUGH 9 PM MDT MONDAY EVENING COVERING WRN NEBRASKA AND THE FRENCHMAN BASIN. && .LBF WATCHES/WARNINGS/ADVISORIES...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR NEZ204-210. && $$ SHORT TERM/EXTENDED...CDC AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
922 AM CDT SUN MAR 25 2012 .UPDATE... MADE SEVERAL CHANGES THIS MORNING TO INCREASE CLOUD COVER AND LOWER MAX TEMPS SIGNIFICANTLY FOR TODAY. STRONG CAA BELOW ABOUT H9 CONTINUES THIS MORNING AND WITH 12Z RUC INDICATING THAT WE WILL BE HARD PRESSED TO MAKE MUCH PROGRESS MIXING MUCH DURING THE REMAINDER OF THE DAY... ANTICIPATING THAT ALL AREAS WILL REMAIN IN THE UPPER 40S TO MID 50S...IF NOT COOLER. BEST CHANCES FOR PARTLY TO MOSTLY SUNNY SKIES WILL BE OVER THE FAR NORTHEAST WHERE SOME OF THE LLV STRATUS CONTINUES TO ERODE SWWD. && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY THROUGH TUESDAY THE POSSIBILITY OF SEVERE STORMS TONIGHT AND AGAIN MONDAY NIGHT WILL BE THE MAIN FORECAST CHALLENGE. AS OF 8Z...AN AREA OF HIGH PRESSURE IS IN CONTROL OF THE NORTHERN PLAINS. THIS HIGH PRESSURE WILL PRODUCE NORTHEASTERLY WINDS IN THE LOWER LEVELS TODAY...WHICH SHOULD RESULT IN CHILLY...BUT ABOVE NORMAL TEMPERATURES. BY LATE THIS AFTERNOON...MODELS DEVELOP A WEAK LLJ WHICH WILL BRING MOISTURE/WAA INTO THE DAKOTAS. SOME HI-RES MODELS ARE INDICATING SHOWER ACTIVITY COULD BE POSSIBLE AFTER 0Z MONDAY IN THE NE CWA...OR WHERE THE BETTER LIFT AND LLM MOISTURE WILL BE HAD. WITH VERY LITTLE CAPE...BELIEVE MOST OF THE ACTIVITY TONIGHT WILL CONSIST OF SHOWERS. MOST OF MONDAY APPEARS TO BE CAPPED WITH BUFFER SOUNDINGS SHOWING A STRATUS LAYER BELOW THE MID LEVEL WAA. HOWEVER THERE SHOULD BE ENOUGH CLEARING DURING THE LATE AFTERNOON HOURS IN THE WESTERN CWA TO ALLOW FOR SURFACE DESTABILIZATION. ATTM...MODELS SHOW AN AREA OF LOW PRESSURE SYSTEM MOVING ACROSS ND...WITH A SURFACE COLD FRONT TRAILING ACROSS WESTERN SD. CONVECTIVE INITIATION SEEMS LIKELY ALONG THE COLD FRONT WITH CONVECTION POSSIBILITY REACHING THE WESTERN CWA AROUND 0Z TUESDAY. BEYOND 0Z TUESDAY...IT BECOMES UNCLEAR WHETHER SURFACE CONVECTION WILL BE ABLE TO MAINTAIN ITSELF OR FRIZZLES WITH A MORE STABLE ENVIRONMENT IN THE EAST. THE CURRENT THINKING IS THAT CONVECTION MAY BECOME ELEVATED DUE TO COOLING OF THE BL. MOST OF TUESDAY IS BEGINNING TO LOOK DRY BUT WINDY WITH CAA MOVING INTO THE REGION BEHIND THE EXITING AREA OF LOW PRESSURE. WITH DECENT MOMENTUM TRANSFER...WINDS WILL LIKELY REACH WIND ADVISORY CRITERIA OF SUSTAINED WINDS OF 30 MPH WITH GUSTS OF 45 MPH. OF NOTE...IF DECENT RAINFALL IN NOT ACHIEVED BY TUESDAY...THEN VERY HIGH TO EXTREME FIRE DANGER WILL BE POSSIBLE. .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY AN UPPER RIDGE BUILDS IN FOR MID WEEK WITH A RETURN OF WARMER AIR ON THURSDAY. SOME OF THIS WARM AIR MAY BE TEMPERED BY INCREASED CLOUD COVER AS A SURFACE LOW AND SHORTWAVE TRACK ACROSS SOUTH DAKOTA...BRINGING THE CHANCE FOR SHOWERS AND TSTORMS THURSDAY AND THURSDAY NIGHT. UPPER RIDGING FRIDAY AND SATURDAY WILL BRING DRIER AND WARMER CONDITIONS. MODELS ARE HINTING AT A MORE ENHANCED AREA OF LOW PRESSURE MOVING ACROSS THE ROCKIES AND INTO THE PLAINS OVER THE WEEKEND. GFS AND ECMWF DIFFER GREATLY WITH SYSTEM EVOLUTION AND TIMING...WITH THE LATEST ECMWF BEING QUITE A BIT QUICKER AND BRINGING A SYSTEM THROUGH ON FRI NIGHT/SAT WHILE THE GFS HAS NOTHING UNTIL SUNDAY. WENT CLOSER TO GFS SOLUTION...KEEPING POPS OUT OF THE FORECAST UNTIL SUNDAY. && .AVIATION... 12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS A LARGE SWATH OF STRATUS ADVECTING INTO THE REGION WILL LEAVE IFR CONDITIONS IN PLACE AT ALL TAF SITES THROUGH 15Z. THERE IS AN AREA OF CLEARING CURRENTLY MOVING INTO SOUTHEAST ND THAT SHOULD PUNCH INTO EASTERN SD...PERHAPS CLEARING OUT KABR/KATY FOR A WHILE AROUND 16Z. THIS SAME AREA WILL LIKELY CONTINUE ITS SOUTHWESTWARD MOVEMENT PUSHING INTO KPIR LATER IN THE MORNING. THERE IS SOME DIFFICULTY IN DETERMINING WHETHER THIS CLEARING WILL SPREAD OR FILL BACK IN...BUT DECIDED TO LIFT ALL TAF SITES TO VFR THIS AFTERNOON AS WINDS INCREASE TO 15 TO 25 KTS. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...CHURCH SHORT TERM...SD LONG TERM...WISE AVIATION...WISE WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
342 PM MDT SUN MAR 25 2012 .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 308 PM MDT SUN MAR 25 2012 MOIST AIR MASS CONTINUES TO RESIDE OVER THE TRI-STATE REGION THIS AFTERNOON AHEAD OF A TROUGH WHICH IS CURRENTLY SITUATED OVER THE PACIFIC COAST. PRIMARY QUESTION FOR TONIGHT IS WHETHER FOG WILL REFORM ACROSS THE AREA. GUIDANCE IS DEPICTING ANYTHING BUT A CONSENSUS WITH RUC MORE WIDESPREAD THAN MOST OTHER GUIDANCE. WILL CONTINUE WITH PATCHY FOG MENTION OVER THE NORTHEAST BUT EVENING SHIFT WILL NEED TO MONITOR SITUATION CLOSELY. FOCUS THEN SHIFTS TO AN ACTIVE WEATHER DAY ON MONDAY WITH A MULTITUDE OF HAZARDS POSSIBLE ACROSS THE AREA. CONFIDENCE IN CRITICAL FIRE WEATHER CONDITIONS IS HIGHEST ACROSS EASTERN COLORADO. SEE FIRE WEATHER SECTION BELOW FOR FURTHER DISCUSSION ON THAT POTENTIAL. WESTERN CONUS TROUGH WILL BEGIN TO TRANSLATE EASTWARD WITH A SHORTWAVE TROUGH LIFTING NORTHEASTWARD INTO THE WESTERN DAKOTAS BY MONDAY EVENING. A DRYLINE WILL BECOME ESTABLISHED OVER EASTERN COLORADO DURING THE LATE MORNING HOURS BUT DOES NOT REALLY MIX EAST OF THE CO/KS BORDER UNTIL LATE MONDAY EVENING. PRESSURE GRADIENT WILL TIGHTEN RAPIDLY AS THE LOW BEGINS TO DEEPEN RESULTING IN ADVISORY CRITERIA WINDS ACROSS THE ENTIRE FORECAST AREA DURING THE AFTERNOON AND EARLY EVENING. HAVE GONE AHEAD AND EXPANDED THE GOING WIND ADVISORY FOR THIS LIKELIHOOD. IN ADDITION TO FIRE WEATHER AND WIND CONCERNS...ALSO HAVE A SMALL CHANCE FOR THUNDERSTORMS TO DEVELOP PRIMARILY ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. STRONGEST DYNAMIC REMAIN NORTH OF THE FORECAST AREA BUT ENOUGH FORCING FOR ASCENT SHOULD BE OBSERVED FOR A FEW HOUR WINDOW. NOT COMPLETELY CONFIDENT THAT CONVECTION WILL DEVELOP BUT THE ENVIRONMENT WOULD BE SUPPORTIVE OF STRONG THUNDERSTORMS IF AN UPDRAFT CAN DEVELOP AND BE SUSTAINED. A COLD FRONT SWEEPS THROUGH THE AREA BETWEEN 00Z AND 06Z. MAY HAVE A BRIEF PERIOD OF GUSTY NORTHWESTERLY WINDS BEHIND THE FRONT GIVEN ANTICIPATED 6 HOUR PRESSURE RISES AS PROGGED BY BOTH THE NAM AND GFS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 308 PM MDT SUN MAR 25 2012 DRY CONDITIONS AND A CONTINUATION OF MUCH ABOVE NORMAL TEMPERATURES WILL CONTINUE FROM TUESDAY THROUGH EARLY THURSDAY AS A BROAD MID/UPPER RIDGE BUILDS BACK ACROSS THE CENTRAL HIGH PLAINS. BY THURSDAY AFTERNOON...FORCING FOR ASCENT ASSOCIATED WITH A SHORTWAVE TROUGH TRANSLATING ACROSS THE DAKOTAS COULD PROVIDE ENOUGH LIFT TO GENERATE CONVECTION ACROSS PRIMARILY NORTHEASTERN PORTIONS OF THE TRI-STATE REGION. ADDITIONAL WEAK SHORTWAVE TROUGHS PASS THROUGH THE AREA THURSDAY NIGHT AND FRIDAY WITH A CONTINUED FOCUS ON EASTERN PORTIONS OF THE AREA. DRY CONDITIONS WILL RETURN FOR THE WEEKEND WITH AFTERNOON TEMPS IN THE MID TO UPPER 70S CONTINUING. SIGNIFICANT FORECAST UNCERTAINTY DEVELOPS BY SUNDAY WITH THE OPERATIONAL GFS/GEFS MEAN AND EC DEPICTING STARKLY DIFFERENT SCENARIOS. THE GFS ATTEMPTS TO DEVELOP A DEEP TROUGH ACROSS THE GREAT BASIN/INTERMOUNTAIN WEST WHILE THE EC SUPPORTS A RIDGE OVER THE SAME GENERAL AREA AND HOLDS THE TROUGH OVER THE PACIFIC NORTHWEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1152 AM MDT SUN MAR 25 2012 KGLD...FOG AND BR ARE QUICKLY DISSIPATING WITH VISIBILITIES IMPROVING. BY 19Z...VFR CONDITIONS WILL RETURN AND ARE EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE PERIOD. KMCK...WINDS HAVE BEEN SLOW TO INCREASE THIS MORNING. CURRENT OBS SHOW INCREASING SURFACE WINDS ACROSS CENTRAL KANSAS AND EXPECT KMCK TO INCREASE IN THE NEXT HOUR. BUFKIT SOUNDING SHOWS A CHANCE FOR FOG DEVELOPING ONCE AGAIN OVERNIGHT THROUGH ABOUT 15Z. OTHERWISE...WINDS WILL INCREASE THIS AFTERNOON AS COVER COVER DECREASES...BECOMING LIGHT FOR A FEW HOURS THIS EVENING. WINDS WILL BEGIN TO INCREASE EARLY TOMORROW MORNING INTO THE AFTERNOON AS LEE TROUGH DEEPENS IN RESPONSE TO APPROACHING UPPER LEVEL TROUGH. && .FIRE WEATHER... ISSUED AT 308 PM MDT SUN MAR 25 2012 HAVE GONE AHEAD AND UPGRADED THE THREE EASTERN COLORADO COUNTIES TO A RED FLAG WARNING FOR MONDAY. LEFT THE FIRE WEATHER WATCH INTACT FOR THE FIRST TIER OF KANSAS AND NEBRASKA COUNTIES AS THERE IS SIGNIFICANT UNCERTAINTY WITH REGARD TO JUST HOW FAR EAST THE DRYLINE WILL MIX DURING THE AFTERNOON. OPTED TO CANCEL THE FIRE WEATHER WATCH FOR THE NEXT TIER OF COUNTIES TO THE EAST AS CONFIDENCE WAS TOO LOW THAT CRITERIA WOULD BE MET IN THESE LOCATIONS. && .CLIMATE... ISSUED AT 308 PM MDT SUN MAR 25 2012 STILL LOOKING AT THE POTENTIAL FOR A FEW RECORDS ACROSS THE TRI- STATE REGION ON MONDAY. ALSO STILL WELL ON TRACK FOR THE WARMEST MARCH ON RECORD AT GOODLAND...BURLINGTON...AND MCCOOK. HERE ARE THE LATEST FIGURES THROUGH MARCH 24. GOODLAND - 48.8 DEGREES SET IN 1907 - CURRENT AVERAGE TEMP 48.6 BURLINGTON - 47.7 DEGREES SET IN 1986 - CURRENT AVERAGE TEMP 47.1 MCCOOK - 48.3 DEGREES SET IN 2007 - CURRENT AVERAGE TEMP 49.9 HILL CITY - 54.3 DEGREES SET IN 1910 - CURRENT AVERAGE TEMP 51.1 WITH MUCH ABOVE NORMAL TEMPERATURES PROJECTED TO CONTINUE THROUGH THE END OF THE MONTH...CONFIDENCE IS VERY HIGH THAT GOODLAND...BURLINGTON...AND MCCOOK WILL SEE THE WARMEST MARCH ON RECORD. IT REMAINS TO BE SEE IF HILL CITY WILL BREAK THE RECORD AS WELL. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...WIND ADVISORY FROM NOON TO 9 PM MDT MONDAY FOR COZ090>092. RED FLAG WARNING FROM NOON TO 9 PM MDT MONDAY FOR COZ252>254. KS...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR KSZ001-013-027-041. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ MONDAY FOR KSZ001>004-013>016-027>029-041-042. NE...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR NEZ079. WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ MONDAY FOR NEZ079>081. && $$ UPDATE...PMM SHORT TERM...PMM/FOLTZ LONG TERM....FOLTZ AVIATION...PMM FIRE WEATHER...PMM/FOLTZ CLIMATE...FOLTZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
456 PM EDT SUN MAR 25 2012 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 454 PM EDT SUN MAR 25 2012 LOW CLOUDS HAVE BEEN VERY PERSISTENT TODAY...AS THE H875 INVERSION HAS BEEN DIFFICULT TO ERRODE. AWAY FROM THE COOLING OFF LK SUPERIOR...THE CLOUDS HAVE MIXED OUT...BUT STILL HAVE A DECENT SWATH OF CLOUDS OVER SRN ONTARIO NEAR THUNDER BAY. MEANWHILE...1033MB SFC HIGH JUST NE OF LK WINNIPEG AND AN ASSOCIATED SFC RIDGE HAS BEEN WORKING INTO WRN LK SUPERIOR. FARTHER SW...DEVELOPING LOW OVER WYOMING AS LED TO SOME MID LVL WAA AND CLOUDS OVER SD AND SRN MN. THESE CLOUDS SHOULD STAY S OF THE AREA TONIGHT AS THE UPPER TROUGH DIGS OVER THE NEW ENGLAND STATES AND BRINGS DRIER MID LVL AIR INTO THE UPPER GREAT LKS. ISSUE FOR TONIGHT WILL BE THE CLOUDS NEAR/OVER LK SUPERIOR. WITH THE WAY THEY HAVE HUNG IN TODAY OVER THE KEWEENAW AND ERN LK...FEELING IS THAT THERE IS A GOOD CHANCE OF THEM HANGING AROUND FOR MUCH OF THE NIGHT. THERE SHOULD BE PLENTY OF LK INSTABILITY...AS H950-925 TEMPS ARE AROUND -9C AND LK TEMPS AROUND 3-4C. QUESTION WILL BE IF THE MOISTURE WILL REMAIN. THE MODELS HAVE BEEN HAVING A DIFFICULT TIME WITH THIS MOISTURE AND MOST HAVE THE MOISTURE DIMINISHING THIS EVENING WITH THE CONTINUED SUBSIDENCE AND DRY AIR WITH THE SFC RIDGE. BUT THE PERSISTENCE OF THE CLOUDS OVER SRN ONTARIO AND CNTRL/ERN LK SUPERIOR CREATES CONCERN ON IT COMPLETELY DIMINISHING. HAVE BUMPED UP CLOUDS TO PARTLY CLOUDY NEAR LK SUPERIOR FOR THE OVERNIGHT HOURS...AS TO SUBSIDENCE...ANTICYCLONIC FLOW...AND DECREASING MOISTURE UNDER THE HIGH PRESSURE RIDGE MAY BE ENOUGH TO DIMINISH THEM. THAT BEING SAID...COULD EASILY SEE THE MOISTURE BECOMING TRAPPED WITH LOSS OF HEATING AND REMAINING WITH THE LK INSTABILITY. DID TRY TO SHOW SOME MOVEMENT TO THE PARTLY CLOUDY SKY AS H925 WINDS VEER THROUGH THE NIGHT...WHICH WOULD FOCUS THE CLOUDS OVER THE N THEN NE FAVORED LOCATIONS. IN ADDITION...13-16Z RUC RUNS TRY TO DEVELOP LK ENHANCED PCPN OVER CNTRL/ERN LK SUPERIOR THIS EVENING AND THEN DROP IT INTO UPPER MI. THE ONLY OTHER HIRES MODEL TO MENTION IT WAS THE REGIONAL GEM. WITH A FEW SHOWERS DEVELOPING TODAY DEVELOPMENT WOULDN/T BE SURPRISING...BUT WITH CONCERNS ON AMNT OF MOISTURE PRESENT DECIDED TO LEAVE OUT. LOWS TONIGHT HAVE HIGH BUST POTENTIAL DUE TO SEVERAL INFLUENCES. NEAR LK SUPERIOR...THE CLOUDS/WIND WILL BE THE MAIN FACTOR. THE COMBINATION OF THE TWO CREATES UNCERTAINTY AND HAVE STUCK WITH A MIDDLE GROUND IN THE UPPER 20S. FARTHER INLAND...TEMPS COULD REALLY TANK ONCE THE WINDS DIMINISH THIS EVENING AND IF SKIES REMAIN MOSTLY CLEAR. PWATS AROUND 0.25IN OR ABOUT 40 PERCENT OF NORMAL AND LIGHT WINDS CREATES A GOOD RADIATIONAL COOLING NIGHT AND EXPECT TEMPS TO FALL NEAR 20. IF THE CLOUDS REMAIN AWAY...COULD SEE VALUES EVEN COLDER INTO THE TEENS OVER THE INTERIOR WEST COLD SPOTS. MONDAY...HIGH PRESSURE CENTERED JUST SW OF JAMES BAY WILL KEEP THE SFC RIDGE OVER THE AREA...WHILE AN UPPER RIDGE WILL START TO BUILD OVER THE NRN PLAINS. RIDGE WILL GRADUALLY SHIFT E THROUGH THE DAY...AS SFC LOW DEVELOPS OVER ERN MONTANA/WYOMING. OTHER THAN THE PREVIOUSLY MENTIONED POTENTIAL FOR LINGERING LK CLOUDS IN THE MORNING...DRY AIR AND SUBSIDENCE FROM THE HIGH SHOULD LEAD TO A MOSTLY SUNNY DAY. MID CLOUDS DEVELOPING UNDER H700 WAA MON AFTN OVER MN AND NW WI...AND WILL APPROACH THE FAR WRN CWA LATE IN THE AFTN. COOL NRLY FLOW OFF LK SUPERIOR WILL KEEP MIXING DOWN NEAR THE LK SHORE AND KEEP HIGHS IN THE 30S. FARTHER INLAND AWAY FROM THE LK INFLUENCE...MIXING TOWARDS H850 TEMPS OF -4C WEST AND -9C EAST WILL PRODUCE HIGHS IN THE LOW-MID 40S...ESPECIALLY ALONG THE WI BORDER. AS FOR DEWPOINTS...MODEL MIXED LAYER DEWPOINT VALUES ARE IN THE LOW SINGLE DIGITS ABOVE ZERO OVER THE E HALF OF THE LAND CWA. THIS HAS BEEN CONSISTENT OVER THE LAST SEVERAL RUNS...SO HAVE ADJUSTED GOING VALUES DOWN A TOUCH AWAY FROM THE MOISTENING AFFECTS OF LK SUPERIOR. THIS LEADS TO RH VALUES FALLING INTO THE UPPER 20S...WITH A FEW MID-LOWER 20S OVER THE ERN CWA. WITH WINDS MAINLY 10KTS OR LESS AND ALONG WITH THE COOLER TEMPS...EXPECT FIRE WX CONCERNS TO BE LIMITED. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 454 PM EDT SUN MAR 25 2012 MONDAY NIGHT AND TUE...THE GFS...ECMWF AND NAM HAVE BEEN CONSISTENT AND WERE IN REASONABLY GOOD AGREEMENT WITH THE SHORTWAVE LIFTING FROM THE PLAINS TO THE NRN GREAT LAKES. STRONG WAA AND 295K- 305K ISENTROPIC LIFT (NOSE OF 850-800MB WINDS 50-55KT) WILL SUPPORT A BAND OF PCPN THROUGH THE CWA LATE MONDAY NIGHT INTO TUESDAY MORNING. THE VERY STRONG WAA IN THE 850-700 MB LAYER PUSHING WARM NOSE TEMPS TO AROUND 5C SHOULD LEAD TO MOSTLY LIQUID PCPN. WITH INCREASING CLOUDS AND WAA OVER THE FAR WEST EXPECT THAT SFC TEMPS SHOULD REBOUND ENOUGH BY THE ONSET OF PCPN TO KEEP PCPN AS RAIN. HOWEVER...OVER INTERIOR WEST AND CENTRAL UPPER MICHIGAN TEMPS INTO THE UPPER 20S TO AROUND 30 MAY LINGER AS THE PCPN MOVES IN. EVAPORATIVE COOLING AT THE ONSET OF PCPN WILL ALSO DELAY LOW LEVEL WARMING. WITH RELATIVELY WARM GROUND TEMPERATURES AFTER THE LONG WARM SPELL...THERE IS ADDITIONAL UNCERTAINTY ON HOW MUCH ICE IF ANY WOULD ACCUMULATE. SO...MENTIONED BOTH RA/FZRA FOR MOST OF THE THE CWA AND HIGHLIGHTED THE HAZARD IN A PORTION OF THE SPS. INSTABILITY FOR TSRA LOOKS MARGINAL...BUT SOME ELEVATED CAPE INTO EDING INTO THE CWA SUPPORTS AT LEAST CONTINUED MENTION OF SLIGHT CHANCE FOR TSRA. TUE NIGHT INTO WED...AS THE DRY SLOT SPREADS ACROSS THE ARA LATE TUE INTO TUE EVENING...PCPN SHOULD DIMINISH TO AREAS OF DRIZZLE OR ISOLATED SHOWERS DURING THE AFTERNOON AND EVENING. AS THE MID LEVEL LOW MOVES OFF TO THE NORTHEAST OF LAKE SUPERIOR AND A TRAILING SHORTWAVE MOVES THROUGH UPPER MI SOME ADDITIONAL WRAP-AROUND LIGHT SHOWERS MAY BE POSSIBLE WED MORNNG. BY THE TIME THE COLDER AIR ARRIVES WED AFTERNOON...DRIER AIR WILL ALSO SPREAD INTO THE REGION. SO...ONLY LOW END POPS FOR SOME LIGHT LAKE ENHANCED PCPN. THU-SUN...HIGH PRES SHOULD BUILD INTO THE AREA THU WITH COOL DRY AND MOSTLY SUNNY CONDITIONS. MODELS CONTINUE TO SUGGEST POTENTIAL FOR ANOTHER SHRTWV AND PCPN CHANCES MOVING INTO THE AREA THU NIGHT INTO FRIDAY EVEN THOUGH CONFIDECNE IN DETAILS IS LOW. A BLOCKING RIDGE TO THE NORTH WITH A SFC HUDSON BAY HIGH EXTENDEDING INTO THE AREA WILL LIMIT PCPN CHANCES TO LOWER END POPS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 132 PM EDT SUN MAR 25 2012 TRICKY AVIATION FORECAST THIS AFTERNOON...AS PERSISTENT LOW CLOUDS HAVE BEEN AFFECTING ALL THREE TAF SITES LONGER THAN EXPECTED. KIWD/KSAW ARE BOTH ON THE EDGE OF CLEARING OUT AND HAVE TRENDED THEM THAT DIRECTION. KCMX WILL LIKELY BE IN THE LOWER CLOUDS THROUGH MUCH OF THE AFTN AND INTO THE EARLY EVENING. QUESTIONS IN THE FORECAST COMES INTO WHAT HAPPENS TONIGHT WITH THE LOW CLOUDS. MODELS SEEM TO BE UNDER DOING THE LINGERING LOW CLOUDS HERE AND IN SRN CANADA AND HAVE TRENDED A TOWARDS SCATTERED CLOUDS...WHICH MAY BE UNDER DONE. THINK LOW CLOUDS WILL DEPEND ON HOW MUCH THEY DIMINISH BY THIS EVENING BEFORE THE BETTER MIXING IS LOST AND AT THIS POINT HAVE LOW CONFIDENCE THAT THEY WILL DIMINISH. WITH WINDS VEERING THROUGH THE NIGHT...THE REMAINING CLOUDS WILL PUSH BACK INTO ALL OF THE SITES IF THEY ARE PRESENT. FUTURE SHIFTS WILL NEED TO MONITOR THE LATEST TRENDS THIS EVENING. HIGH PRESSURE RIDGE AND ASSOCIATED SUBSIDENCE/DRIER AIR WILL ARRIVE TOMORROW AND LEAD TO CLEARING SKIES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 454 PM EDT SUN MAR 25 2012 HIGH PRESSURE RIDGE MOVING INTO LAKE SUPERIOR TONIGHT WILL GRADUALLY DIMINISH THE PRESSURE GRADIENT OVER LAKE SUPERIOR AND LEAD TO A GRADUAL DIMINISHING TREND IN THE VEERING WINDS TONIGHT INTO MONDAY MORNING. AS THE LOW SHIFTS E ON MONDAY...A LOW PRESSURE SYSTEM DEVELOPING IN THE NRN PLAINS WILL SHIFT EAST AND ACROSS THE UPPER GREAT LAKES TUESDAY NIGHT AND WEDNESDAY. THIS COULD PRODUCE A SOUTHERLY GALE FORCE GUSTS TO 35KTS ON TUESDAY OVER EASTERN LAKE SUPERIOR. HIGH PRESSURE RIDGE WILL THEN BUILD OVER THE UPPER GREAT LAKES WED NIGHT AND THURSDAY...KEEPING WINDS BELOW 25KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON FOR LSZ266. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...JLB AVIATION...SRF MARINE...SRF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
105 PM CDT SUN MAR 25 2012 .AVIATION...TWO AREAS OF STRATUS CONTINUE TO PERSIST ACROSS THE AREA. ONE AREA HAS SHOWN SOME SIGNS OF DECREASING ACROSS NORTH CENTRAL NEBRASKA...HOWEVER IT APPEARS THAT IT MAY THIN THIS AFTERNOON BUT EXPAND AGAIN TONIGHT. ONLY MODERATE CONFIDENCE IN THIS FORECAST...BUT IT APPEARS THAT MVFR AND LOCALLY IFR CEILINGS WILL PERSIST THIS AFTERNOON AND INTO TONIGHT. THE OTHER AREA OF STRATUS HAS BEEN EXPANDING ACROSS SOUTHWEST NEBRASKA...AND NOW INTO THE KLBF TERMINAL. MODERATE CONFIDENCE HERE TOO...AS STRATUS MAY PERSIST THROUGH MUCH OF THE AFTERNOON AND POSSIBLE INTO THE EVENING. WILL CONTINUE TO UPDATE AND MONITOR. ISOLATED THUNDERSTORMS MAY DEVELOP LATE THIS AFTERNOON AND OVERNIGHT ALONG AND NORTH OF A KBUB TO KIEN LINE. && .PREV DISCUSSION... /ISSUED 626 AM CDT SUN MAR 25 2012/ ARCTIC AIR CONTINUES TO BACK IN ACROSS NCNTL NEB THIS MORNING PRODUCING A SHALLOW DECK OF STRATUS. WINDS STAY EAST MOST OF THE DAY BENEATH THE DECK. WORSE THE RUC SHOWS PWAT POOLING BEHIND THE FRONT ALONG THE SD BORDER WHICH CANT BE A GOOD WAY TO ERODE STRATUS. SO 1ST PERIOD HIGH TEMPS HAVE BEEN MARKED DOWN USING THE RUC13 AS A GUIDE. PREV DISCUSSION... /ISSUED 351 AM CDT SUN MAR 25 2012/ HAND ANALYSIS OF THE H5 CHART REVEALS THAT SHORTWAVE RIDGING HAS BECOME FULLY ESTABLISHED ACROSS THE CENTRAL STATES...WITH A TROUGH OF LOW PRESSURE DIGGING SOUTH OFF CENTRAL CALIFORNIA. A SECOND AREA OF LOW PRESSURE RESIDES EAST OF THE CENTRAL MISSISSIPPI RIVER VALLEY AND CONTINUES TO PUSH SOUTHEAST TOWARD THE COAST OF SOUTH CAROLINA. THIS PATTERN PRESENTS GENERAL SOUTHWEST FLOW ALOFT ACROSS WESTERN NEBRASKA WITH THE RIDGE AXIS BISECTING THE FORECAST AREA. AT THE SURFACE...WIND SPEEDS ARE GENERALLY LIGHT AND FROM THE NORTHEAST ACROSS WEST CENTRAL NEBRASKA WITH AN AREA OF HIGH PRESSURE CENTERED NORTH OF THE US/CANADIAN BORDER. FURTHER WEST OVER THE HIGHER TERRAIN OF EASTERN WYOMING/COLORADO...THE WIND IS BEGINNING TO VEER SLIGHTLY TO THE SOUTHEAST...AS A BROAD AREA OF LOW PRESSURE BEGINS TO DEEPEN. THROUGH 12Z MONDAY. SURFACE HIGH PRESSURE OVER CANADA WILL BUILD EAST THROUGH THE DAY TODAY AS WEST COAST UPPER TROUGH ROTATES INLAND AND TAKES ON A STRONG NEGATIVE TILT. SURFACE LOW PRESSURE OVER THE ROCKIES WILL CONTINUE TO DEEPEN AND THUS STRENGTHEN SOUTHERLY RETURN FLOW BACK ACROSS ALL OF WESTERN AND NORTH CENTRAL NEBRASKA. MODEL GUIDANCE INDICATES INCREASING ATMOSPHERIC MOISTURE WITH THE SOUTHERLY FLOW AS SURFACE TD/S RETURN ABOVE 45F FOR MOST IF NOT ALL LOCATIONS ACROSS THE CWA. THIS SHOULD HELP DECREASE THE FIRE POTENTIAL THIS AFTERNOON AS SURFACE T/S REMAIN IN THE 70/S TO LOW 80/S ALLOWING FOR EXPECTED RH VALUES WELL ABOVE RED FLAG MINIMUM CRITERIA. WITH THE INCREASING MOISTURE...STORM CHANCES ARE A POSSIBILITY LATE THIS AFTERNOON AND TONIGHT /FOR LOCATIONS MAINLY NORTH OF HIGHWAY TWO ACROSS NORTHWEST NEBRASKA/. A WARM FRONT WILL CONTINUE TO LIFT NORTHWARD THROUGH THE AFTERNOON...STALLING ALONG OR NEAR THE SOUTH DAKOTA BORDER BY 00Z MONDAY. SYNOPTIC LIFT WILL BE ON THE INCREASE AS THETA-E ADVECTION OCCURS AND IS MAXIMIZED ACROSS NORTHWEST NEBRASKA. MIDLEVEL LAPSE RATES WILL BE STEEP...HOWEVER THERE IS QUESTION AS TO IF STORMS ARE ABLE TO BREACH THE CAPPING INVERSION AS STRONG RIDGING REMAINS ENTRENCHED OVER THE CENTRAL AND NORTHERN PLAINS. IF SO...THE STORMS WOULD BE ABLE TO WORK ON MODEST INSTABILITY OF 500-1000 J/KG OF CAPE AND 0-6KM BULK SHEAR OF 45KTS. STORMS WOULD HAVE THE POTENTIAL TO PRODUCE SEVERE HAIL AND CERTAINLY SEVERE WIND GUSTS AS A SOMEWHAT INVERTED V PROFILE IS SHOWN IN BUFR SOUNDINGS. GOING INTO THE EVENING...A LOW LEVEL JET WILL STRENGTHEN AND PROVIDE A FURTHER FOCUS OF STORM DEVELOPMENT ACROSS NORTHERN AND NORTH CENTRAL NEBRASKA OVERNIGHT...WILL CONTINUE THE MENTION OF ELEVATED SHOWERS/THUNDERSTORMS. SEVERAL CONCERNS IN THE FORECAST FOR MONDAY AS A PLETHORA OF WEATHER IS EXPECTED. FIRST...WILL ISSUE A FIRE WEATHER WATCH FOR FIRE ZONES 204 AND 210 WITH THIS MORNING FORECAST PACKAGE. A DRY LINE IS EXPECTED BECOME ESTABLISHED AND PUSH EAST ACROSS THE PANHANDLE INTO WEST CENTRAL NEBRASKA MONDAY AFTERNOON. MODEL GUIDANCE INDICATES TD/S FALLING BELOW 25F WITH THE PASSAGE. GIVEN ABNORMALLY HIGH EXPECTED TEMPERATURES...RH VALUES ACROSS THE EASTERN PANHANDLE WILL FALL BELOW 15 PERCENT /RED FLAG CRITERIA/ BY MIDAFTERNOON ON MONDAY. MEANWHILE A TIGHT SURFACE GRADIENT WILL EXIST ACROSS THE HIGH PLAINS AS SURFACE PRESSURE RAPIDLY FALLS IN ADVANCE OF THE WEST COAST TROUGH. EXPECT SURFACE WIND SPEEDS TO GUST ABOVE 30 MPH FOR MUCH OF THE AFTERNOON MONDAY. SURFACE LOW PRESSURE WILL QUICKLY DEEPEN AND PUSH NORTHEAST INTO EASTERN NORTH DAKOTA ON LATE MONDAY NIGHT...WHICH WILL DRAG A COLD FRONT THROUGH WESTERN NEBRASKA. AGAIN WIND SPEEDS LOOK PROBLEMATIC....AS HEIGHT RISES ON THE ORDER OF 14MB/3HR ARE SUGGESTED BY SHORT TERM SOLUTIONS. A WIND ADVISORY IS EXPECTED...IF NOT HIGH WIND HIGHLIGHTS MONDAY AFTERNOON AND NIGHT. THE COLD FRONT IS EXPECTED TO QUICKLY CROSS THE CWA MONDAY EVENING...EVENTUALLY OVERTAKING THE DRYLINE. INITIALLY A STRONG CAPPING INVERSION WILL LIMIT STORM DEVELOPMENT ACROSS MUCH OF THE CWA...HOWEVER AS LOW-LEVEL CONVERGENCE ALONG THE COLD FRONT INCREASES...STORM DEVELOPMENT SHOULD BEGIN. LOOKING AT MODEST CAPE OF 500-1000 J/KG WITH 6KM SHEAR OF GREATER THAN 40KTS WOULD PROVIDE THE OPPORTUNITY FOR SEVERE STORMS WITH HAIL AND AND POSSIBLY DAMAGING WINDS. TUESDAY MAY BE ACTIVE IN TERMS OF FIRE WEATHER AGAIN AS ABNORMALLY DRY AIR WILL REMAIN IN PLACE BEHIND THE DEPARTING SYSTEM. POOR RH RECOVERY WILL AID IN PRIMING AVAILABLE FUELS...AND WITH A GOOD PORTION OF THE FA WELL BELOW 20 PERCENT RH TUESDAY AFTERNOON...FIRE CONCERNS MAY BE REALIZED. A COUPLE FACTORS GOING AGAINST THE FIRE POTENTIAL FOR NOW...ONE IS THAT WIND SPEEDS SHOULD EASE WITH THE RELAXING PRESSURE GRADIENT. AND TWO...EARLY GREEN UP IS OCCURRING...WILL NEED TO CONTACT AREA FMO/S TO DETERMINE FUEL AVAILABILITY. AS FOR TEMPERATURES...WILL TREND THE FORECAST DOWN SLIGHTLY ON TUESDAY WITH THE FRONTAL PASSAGE...YET HIGHS WILL STILL BE ABOVE AVERAGE RANGING FROM THE MID 60S ACROSS NORTHWEST NEBRASKA...TO THE LOW TO MID 70S SOUTH OF I80. BEYOND TUESDAY...A WEAK DISTURBANCE CROSSES THE REGION LATE THURSDAY BRINGING A SLIGHT CHANCE OF POPS BACK ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. OTHERWISE SHORTWAVE RIDGING RETURNS JUST IN TIME FOR THE WEEKEND...WITH ANOTHER TROUGH DIGGING DOWN THE WEST COAST OF NA. WILL KEEP T/S ABOVE AVERAGE THROUGH THE EXTENDED AND GO DRY BEYOND FRIDAY MORNING. FIRE WEATHER... STRONG DOUBLE BARREL LOW PRESSURE WILL DEEPEN TO AROUND 990MB ACROSS THE NRN HIGH PLAINS MONDAY AFTERNOON. ALL MODELS ARE DRAWING VERY DRY AIR NORTH INTO THE LOW AND PRODUCING SOUTH WINDS IN EXCESS OF 30 MPH THROUGHOUT WRN NEB AS THE LOW DEEPENS. A POWERFUL PACIFIC COLD FRONT WILL THEN RACE EAST THROUGH WRN NEBRASKA MONDAY EVENING PRODUCING VERY STRONG WEST WIND GUSTS. ISOLATED THUNDERSTORMS AND DRY LIGHTNING MAY DEVELOP ALONG THE DRYLINE AHEAD OF THE COLD FRONT. THE DRYLINE SHOULD BE LOCATED NEAR HIGHWAY 61 MONDAY AFTERNOON. A FIRE WEATHER WATCH WILL BE ISSUED THROUGH 9 PM MDT MONDAY EVENING COVERING WRN NEBRASKA AND THE FRENCHMAN BASIN. && .LBF WATCHES/WARNINGS/ADVISORIES...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR NEZ204-210. && $$ AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1226 PM CDT SUN MAR 25 2012 .UPDATE... UPDATED FORECAST TO INCREASE CLOUD COVER AND LOWER MAX TEMPS SIGNIFICANTLY FOR TODAY. STRONG CAA BELOW ABOUT H9 CONTINUES THIS MORNING AND WITH 12Z RUC INDICATING THAT WE WILL BE HARD PRESSED TO MAKE MUCH PROGRESS MIXING MUCH DURING THE REMAINDER OF THE DAY... ANTICIPATING THAT ALL AREAS WILL REMAIN IN THE UPPER 40S TO MID 50S...IF NOT COOLER. BEST CHANCES FOR PARTLY TO MOSTLY SUNNY SKIES WILL BE OVER THE FAR NORTHEAST WHERE SOME OF THE LLV STRATUS CONTINUES TO ERODE SWWD. UPDATED AVIATION SECTION LISTED BELOW... && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY THROUGH TUESDAY THE POSSIBILITY OF SEVERE STORMS TONIGHT AND AGAIN MONDAY NIGHT WILL BE THE MAIN FORECAST CHALLENGE. AS OF 8Z...AN AREA OF HIGH PRESSURE IS IN CONTROL OF THE NORTHERN PLAINS. THIS HIGH PRESSURE WILL PRODUCE NORTHEASTERLY WINDS IN THE LOWER LEVELS TODAY...WHICH SHOULD RESULT IN CHILLY...BUT ABOVE NORMAL TEMPERATURES. BY LATE THIS AFTERNOON...MODELS DEVELOP A WEAK LLJ WHICH WILL BRING MOISTURE/WAA INTO THE DAKOTAS. SOME HI-RES MODELS ARE INDICATING SHOWER ACTIVITY COULD BE POSSIBLE AFTER 0Z MONDAY IN THE NE CWA...OR WHERE THE BETTER LIFT AND LLM MOISTURE WILL BE HAD. WITH VERY LITTLE CAPE...BELIEVE MOST OF THE ACTIVITY TONIGHT WILL CONSIST OF SHOWERS. MOST OF MONDAY APPEARS TO BE CAPPED WITH BUFFER SOUNDINGS SHOWING A STRATUS LAYER BELOW THE MID LEVEL WAA. HOWEVER THERE SHOULD BE ENOUGH CLEARING DURING THE LATE AFTERNOON HOURS IN THE WESTERN CWA TO ALLOW FOR SURFACE DESTABILIZATION. ATTM...MODELS SHOW AN AREA OF LOW PRESSURE SYSTEM MOVING ACROSS ND...WITH A SURFACE COLD FRONT TRAILING ACROSS WESTERN SD. CONVECTIVE INITIATION SEEMS LIKELY ALONG THE COLD FRONT WITH CONVECTION POSSIBILITY REACHING THE WESTERN CWA AROUND 0Z TUESDAY. BEYOND 0Z TUESDAY...IT BECOMES UNCLEAR WHETHER SURFACE CONVECTION WILL BE ABLE TO MAINTAIN ITSELF OR FRIZZLES WITH A MORE STABLE ENVIRONMENT IN THE EAST. THE CURRENT THINKING IS THAT CONVECTION MAY BECOME ELEVATED DUE TO COOLING OF THE BL. MOST OF TUESDAY IS BEGINNING TO LOOK DRY BUT WINDY WITH CAA MOVING INTO THE REGION BEHIND THE EXITING AREA OF LOW PRESSURE. WITH DECENT MOMENTUM TRANSFER...WINDS WILL LIKELY REACH WIND ADVISORY CRITERIA OF SUSTAINED WINDS OF 30 MPH WITH GUSTS OF 45 MPH. OF NOTE...IF DECENT RAINFALL IN NOT ACHIEVED BY TUESDAY...THEN VERY HIGH TO EXTREME FIRE DANGER WILL BE POSSIBLE. .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY AN UPPER RIDGE BUILDS IN FOR MID WEEK WITH A RETURN OF WARMER AIR ON THURSDAY. SOME OF THIS WARM AIR MAY BE TEMPERED BY INCREASED CLOUD COVER AS A SURFACE LOW AND SHORTWAVE TRACK ACROSS SOUTH DAKOTA...BRINGING THE CHANCE FOR SHOWERS AND TSTORMS THURSDAY AND THURSDAY NIGHT. UPPER RIDGING FRIDAY AND SATURDAY WILL BRING DRIER AND WARMER CONDITIONS. MODELS ARE HINTING AT A MORE ENHANCED AREA OF LOW PRESSURE MOVING ACROSS THE ROCKIES AND INTO THE PLAINS OVER THE WEEKEND. GFS AND ECMWF DIFFER GREATLY WITH SYSTEM EVOLUTION AND TIMING...WITH THE LATEST ECMWF BEING QUITE A BIT QUICKER AND BRINGING A SYSTEM THROUGH ON FRI NIGHT/SAT WHILE THE GFS HAS NOTHING UNTIL SUNDAY. WENT CLOSER TO GFS SOLUTION...KEEPING POPS OUT OF THE FORECAST UNTIL SUNDAY. && .AVIATION... 18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS IFR STRATUS LAYER HAS BROKEN SOMEWHAT AND MOVED SOUTHWEST...ALLOWING FOR VFR CONDITIONS AT KATY/KABR AND SHORTLY KMBG. THIS CLOUD DECK WILL STALL OVER KPIR...AND MAY LIFT SOMEWHAT THROUGH THE REMAINDER OF THE DAY. AS LOW PRESSURE DEVELOPS TO THE SOUTH...THE REMNANTS OF THE STRATUS AND A SECOND DEVELOPING VFR/MVFR DECK WILL MOVE OVERHEAD. WINDS WILL CONTINUE OUT OF THE EAST AND STRENGTHEN TOWARDS MORNING. VFR VISBY EXPECTED THROUGH THE PERIOD...DO NOT ANTICIPATE ENOUGH WIDESPREAD SHOWER ACTIVITY DURING THIS TAF PERIOD TO INCLUDE IN FORECAST. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...CHURCH SHORT TERM...SD LONG TERM...WISE AVIATION...CONNELLY WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
251 PM CDT SUN MAR 25 2012 .SHORT TERM...TONIGHT AND MONDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE COLD FRONT DROPPING INTO NORTHERN ILLINOIS EARLY THIS AFTERNOON WHILE CANADIAN HIGH PRESSURE IS BUILDING SOUTH INTO THE NORTHERN MISSISSIPPI VALLEY. LOW STRATO-CU DISSIPATED RATHER QUICKLY EARLIER TODAY AS MIXING INTO DRIER AIR OVERWHELMED THE SHALLOW COOL AND MOIST AIRMASS. STILL SOME LINGERING CU OVER EAST-CENTRAL WISCONSIN...THOUGH TRENDS SUPPORT IT DISSIPATING AS WELL OVER THE NEXT COUPLE HOURS. UPSTREAM IS PRETTY QUIET...WITH ONLY MID AND HIGH CLOUDS PUSHING ACROSS THE DAKOTAS. AS HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION TONIGHT...LOW TEMPS AND HEADLINES ARE THE MAIN FORECAST CONCERNS. TONIGHT...LAST NIGHTS COLD FRONT WILL CONTINUE TO SAG SOUTH TOWARDS THE OHIO VALLEY WHILE CANADIAN HIGH PRESSURE WILL BUILD INTO SOUTHERN ONTARIO AND THE WESTERN GREAT LAKES. THIS INCOMING AIRMASS FROM CANADA IS QUITE DRY AND WILL DROP PWATS TO UNDER A QUARTER OF AN INCH. THOUGH AIRMASS IS VERY DRY...NOT IDEAL RADIATIONAL COOLING CONDITIONS WILL BE IN PLACE FOR TONIGHT. WILL HAVE SCT-BKN MID AND HIGH CLOUDS ARRIVE FROM THE NORTHERN PLAINS INTO MUCH OF CENTRAL AND EAST-CENTRAL WISCONSIN BY LATE THIS EVENING. THE PRESSURE GRADIENT WILL ALSO REMAIN FAIRLY TIGHT OVER NE WISCONSIN WHERE NE WINDS FUNNELED DOWN THE BAY...AND ALSO OFF LAKE MICHIGAN WILL KEEP THE BL RATHER BREEZY. NORTH-CENTRAL WISCONSIN WILL SEE 1000-850MB WINDS AROUND 15 KTS...WHICH IS RIGHT ON THE EDGE FOR DECOUPLING. AM GOING TO LEAN TOWARDS DECOUPLING OCCURRING...DUE TO SANDY SOIL EFFECTS AND CLOUDS SHIFTING SOUTH THROUGH THE NIGHT. AS A RESULT...MID TWENTY LOWS SEEM PERFECTLY REASONABLE UP NORTH...AND SEE LITTLE REASON TO ADJUST HEADLINES. DID RAISE LOWS A DEGREE OR TWO OVER CENTRAL AND EAST-CENTRAL WISCONSIN BECAUSE OF CLOUDS AND WIND. LOWS IN THE LOWER TO MIDDLE 30S HERE. MONDAY...MID-LEVEL CLOUDS WILL STALL OVER SW WISCONSIN TOMORROW MORNING AND WILL RETURN NE IN THE AFTERNOON WHEN THE COLD FRONT STARTS RETURNING NORTH. NE WISCONSIN WILL SEE A MOSTLY SUNNY DAY...BUT CENTRAL AND NORTH-CENTRAL WISCONSIN WILL SEE A GRADUAL INCREASE IN CLOUDS. HIGHS RANGING FROM THE LOWER TO MIDDLE 40S EVERYWHERE. .LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. THE WEATHER WILL BE MORE SEASONABLE THAN THE LAST TWO WEEKS WITH FLATTER ALMOST ZONAL FLOW OVER MUCH OF THE REGION THROUGH FRIDAY. SIGNIFICANT MODEL DIFFERENCES FOR NEXT SATURDAY AND SUNDAY WITH HIGH AMPLITUDE FLOW EXPECTED NEXT WEEK. UPPER TROUGH LIFTING NORTHEAST THROUGH THE NORTHERN PLAINS MONDAY NIGHT WILL BRING SHOWERS AND ELEVATED THUNDERSTORMS MONDAY NIGHT AND EARLY TUESDAY. THERE MIGHT BE ENOUGH COLD AIR FOR SLEET TO BE MIXED IN ACROSS THE NORTHERN PART OF THE FORECAST AREA. A COLD FRONT MOVES THROUGH TUESDAY AFTERNOON OR EVENING ACCOMPANIED BY STRONG WINDS IN THE LOW LEVELS...LOTS OF SHEAR AND DECENT UPPER SUPPORT. MOISTURE SHOULD BE LACKING THOUGH WHICH WILL LIMIT INSTABILITY. THERE IS SOME CHANCE OF SEVERE THUNDERSTORMS IF MOISTURE IS MORE PLENTIFUL THAN CURRENTLY EXPECTED. COOLER WEATHER IS EXPECTED FOR WEDNESDAY NIGHT THROUGH FRIDAY AS CANADIAN HIGH SINKS SOUTH INTO THE GREAT LAKES. WILL LIKELY HAVE SOME SUB FREEZING NIGHTS...WHICH IS COMPLETELY NORMAL FOR THIS TIME OF THE YEAR...BUT MORE OF A CONCERN THIS YEAR DUE TO UNUSUAL WARMTH THAT HAS STARTED AN EARLY GROWING SEASON. BIG DIFFERENCES FOR NEXT SATURDAY AND SUNDAY WITH THE GFS AND ECMWF ALMOST 180 DEGREES OUT OF PHASE OVER OUR AREA. && .AVIATION...DRY AIR ARRIVING BEHIND A COLD FRONT WILL DISSIPATE ANY LINGERING MVFR STRATUS EARLY THIS AFTERNOON WHICH WILL LEAVE VFR CONDITIONS THROUGH TOMORROW. WINDS WILL SHIFT AROUND TO THE NORTHEAST TONIGHT...AND WILL BECOME GUSTY AT TIMES OVER NORTHEAST WISCONSIN. MID-LEVEL CLOUDS ALSO ARRIVE TONIGHT...BUT DRY AIR IN THE LOW LEVELS WILL PREVENT ANY PRECIP. MID CLOUDS WILL SHIFT SW TOMORROW MORNING BEFORE RETURNING NE TOMORROW AFTERNOON. MPC && .MARINE... A WARM FRONT WILL PUSH NORTHWARD ACROSS THE AREA TUESDAY. GUSTS TO NEAR GALE FORCE FROM THE SOUTHEAST/SOUTH ARE POSSIBLE ON TUESDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 2 AM TO 8 AM CDT MONDAY FOR WIZ005-010>013- 018-019-021. && $$ MPC/RDM
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
120 PM CDT SUN MAR 25 2012 .UPDATE... STRATUS ON THE LEADING EDGE OF THE COLD FRONT IS WORKING ITS WAY DOWN THE STATE INTO SOUTHERN WISCONSIN EARLY THIS AFTERNOON. WINDS IN THE WESTERN HALF OF THE STATE HAVE BECOME MORE NW TO NNW BEHIND THE FRONT. CLOUDS ASSOCIATED WITH THE FRONT IN THE WEST HALF WERE LOW...BELOW 1000 FEET. MEANWHILE...THE COLD FRONT RACED DOWN THE LONG AXIS OF LAKE MICHIGAN AND WINDS SHIFTED TO THE NORTHEAST IN INCREASED. THE NORTHEAST WINDS HIT KENOSHA BEFORE 10 AM. THE MOISTURE THAT PUSHED INLAND FROM THE LAKE HIT THE KETTLE MORRAINE AND BROKEN CUMULUS CLOUDS POPPED UP. SKIES ARE ACTUALLY CLEAR ALONG THE LAKE AT THIS TIME SOUTH OF MILWAUKEE...BUT EXPECTING THIS AREA TO FILL IN SOON. BROKEN CU JUST FILLED IN ACROSS ALL OF SOUTHERN WI IN THE PAST HALF HOUR AS WELL. CLOUDS ASSOCIATED WITH THE NORTHEAST FLOW ARE A LITTLE HIGHER...AROUND 2000 FEET. WINDS ARE NORTHEAST IN FOND DU LAC LATE THIS MORNING...WITH PRESSURE RISES BEHIND THE NORTHEAST WIND SHIFT OFF THE LAKE FAIRLY STRONG. THIS MEANS WE SHOULD EXPECT THE NORTHEASTERLY WIND DIRECTION TO WIN OUT OVER THE NORTHWESTERLY WINDS THIS AFTERNOON...WITH THE NORTHEAST WINDS PUSHING FURTHER AND FURTHER INLAND WITH TIME. RUC SHOWS THE NNE WINDS SPREADING ACROSS THE WHOLE FORECAST AREA BY THIS AFTERNOON. HOWEVER...CURRENT CONDITIONS WOULD SHOW THE NE/NW WIND BOUNDARY TO STALL AROUND THE MADISON/JANESVILLE AREA. WITH THE STRATUS SPREADING INTO SOUTHERN WI WITH THE FRONT COMING IN EARLIER THAN ANTICIPATED...TEMPERATURES IN THE NORTHERN FORECAST AREA WILL NOT MAKE IT INTO THE UPPER 60S...SO CUT BACK ON HIGH TEMPS THERE AND ALONG THE LAKE AS WELL. && .AVIATION/18Z TAFS/... IFR STRATUS ASSOCIATED WITH A COLD FRONT MOVING DOWN FROM NORTHWEST WI IS OVER WISCONSIN DELLS EARLY THIS AFTERNOON. THESE CLOUDS ARE NOT EXPECTED TO MAKE IT TOO MUCH FURTHER SOUTHEAST DUE TO THE NORTHEASTERLY WINDS OFF THE LAKE COLD FRONT BEATING THEM BACK. A COLD FRONT RACED DOWN THE LAKE THIS MORNING...CAUSING WINDS TO BECOME NORTHEAST AND INCREASE. THE COOL AIR ALONG THE FRONT BROUGHT STRATUS CLOUDS DOWN THE LAKE...WHICH HAVE JUST RECENTLY SPREAD INLAND TO MKE WITH IFR CIGS. CIGS ARE GENERALLY MVFR AROUND THE AREA. MEANWHILE...BROKEN MVFR TO VFR CUMULUS DEVELOPED ALL ACROSS SOUTHERN WI WITH THE DAYTIME HEATING. FOR TONIGHT...EXPECTING SOUTHEAST WI TO BE MUCH SLOWER TO CLEAR AFTER DARK THAN SOUTH CENTRAL WI NEAR MSN. HOWEVER...EXPECT CLEARING OVERNIGHT. THEN A SECOND SURGE OF COLDER AIR IS EXPECTED TO COME DOWN THE LAKE MON MORNING WITH A CHANCE FOR STRATUS. MEDIUM TO LOW CONFIDENCE ON THE STRATUS SCENARIO. OTHERWISE...MID CLOUDS SHOULD SPREAD INTO WESTERN AND CENTRAL WI THROUGH THE DAY...WITH A CHANCE FOR SHOWERS AND ISOLATED THUNDER MONDAY NIGHT. && .MARINE...DRY AIR ON A LAKE COLD FRONT FUNNELED DOWN LAKE MICHIGAN THIS MORNING...ERODING AWAY THE AREAS OF FOG THAT WERE JUST OFF SHORE OF SOUTHEAST WI AND NORTHEAST IL. LOW CLOUDS ARE SPREADING INTO THE SOUTH HALF OF LAKE MICHIGAN THIS AFTERNOON. A REINFORCING PUSH OF LOW LEVEL COLD AIR OVER THE WARMER LAKE WATERS TONIGHT WL RESULT IN STEEP LOW LEVEL LAPSE RATES. THESE LOW LEVEL UNSTABLE CONDITIONS OVER THE LAKE WILL ALLOW GUSTY WINDS IN EXCESS OF 22KTS TO REACH THE LAKE SURFACE OVERNIGHT. HENCE A SMALL CRAFT ADVY IS IN EFFECT FROM THIS EVENING THROUGH MONDAY MORNING. A TIGHTENING PRESSURE GRADIENT AHEAD OF STRONG LOW PRESSURE IN THE NORTHERN PLAINS WILL RESULT IN GUSTY WINDS REDEVELOPING OVER THE NEARSHORE WATERS OF LAKE MI LATE MONDAY NIGHT...CONTINUING ON TUESDAY. && .PREV DISCUSSION... /ISSUED 328 AM CDT SUN MAR 25 2012/ TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM. WL POST DENSE FOG ADVY FOR MOST OF MY WEST FOR EARLY THIS MORNING. DRIER AIR IN THE MID LEVELS CAUSING CLEARING OF 4-5K FT CLOUDS ACROSS WEST AND NORTH...AND APPEARS CLEARING TREND WL CONTINUE INTO THE SOUTHEAST EARLY THIS MORNING. DENSE FOG FORMING RELATIVELY QUICKLY BEHIND THE CLEARING LINE...AND THINKING DENSE FOG MAY LAST FOR SEVERAL HOURS BEFORE DRIER AIR AT LOW LEVELS SAGS INTO THE SOUTH FROM CENTRAL WI. MAY NEED TO EXPAND DENSE FOG ADVY EAST INTO PARTS OF SOUTHEAST WI AS CLOUDS CLEAR EARLY THIS MRNG. SHORT TERM GUIDANCE NOT HANDLING UPSTREAM WIDESPREAD STRATUS IN BETTER COLD AIR ADVECTION OVER FAR NORTHERN WI INTO NRN MN EARLY THIS MRNG. POTENTIAL FOR SOME OF THESE CLOUDS TO MAKE IT INTO SRN WI LATER TODAY...BUT WL BE LESS OPTIMISTIC WITH CLOUD COVER TODAY INTO TNGT. SHOULD BE ENOUGH SUNSHINE TO WARM BACK INTO THE 60S MOST AREAS AWAY FROM LAKE MICHIGAN. DOWNSTREAM AMPLIFYING LONG WAVE TROFFING OVER ERN CONUS WILL RESULT IN SHORT WAVE RIDGING UPSTREAM OVER CENTRAL CONUS. LOW LEVEL JET WL INCREASE TO THE WEST OF WI TONIGHT...FOCUSED OVER THE ERN DAKOTAS INTO MN...NORTH AND WEST OF MAIN RIDGE. WHILE LOW LEVEL RIDGING AND LIGHT WINDS WILL EXTEND INTO SRN WI...PUSH OF MID LEVEL MOISTURE WITH WEAK MID-LEVEL WARM AIR ADVECTION WL BE LOCATED UPSTREAM OVER SRN MN. MID LEVEL CLOUDS WL LIKELY PUSH INTO SRN WI...BUT NOT ENOUGH MOISTURE AND FORCING EXPCD TO TRIGGER PRECIP IN THIS AREA...SO REMOVED LOW POPS FROM WEST. EXPC TEMPS TO DROP INTO THE 30S...BUT BOUNDARY LAYER MIXING SHOULD PREVENT WIDESPREAD FROST FORMATION. MONDAY - CONFIDENCE...MEDIUM EAST FLOW AROUND DEPARTING HIGH WILL MAKE FOR TEMPS CLOSER TO A NORMAL MARCH DAY. SURFACE HIGH WILL DOMINATE WITH MODELS KEEPING PRECIP FURTHER BACK TO THE WEST. ISENTROPIC ANALYSIS DOES SHOW MID LEVEL MOISTENING WITH LOWER CONDENSATION PRESSURE DEFICITS AND SOME WEAK ADIABATIC OMEGA...HOWEVER SOUNDINGS AND LOWER LEVEL ANALYSIS REVEALS QUITE A BIT OF DRY AIR TO OVERCOME. WAS GOING TO GO THE SPRINKLE ROUTE IN THE WESTERN CWA BUT PREFER TO GO DRY AT THIS POINT. MONDAY NIGHT - CONFIDENCE...MEDIUM MID LEVEL RIDGE AXIS SHIFTS TO OUR EAST. STRONG VORT MAX RIDES INTO THE DAKOTAS. 850 MILLIBAR SOUTHWEST JET INCREASES THOUGH CORE OF STRONGEST WINDS TO OUR NORTHWEST CLOSER TO THE BETTER GRADIENT AROUND THE STRONG DAKOTAS LOW. DECENT 850 MOISTURE/THERMAL ADVECTION WITH THIS PATTERN. MARKED INCREASE IN ISENTROPIC ADIABATIC OMEGA AND MIXING RATIOS. NAM ELEVATED CAPE FROM 825 MILLIBARS SEVERAL HUNDRED J/KG. PLENTY OF LOW LEVEL MOISTURE BUT AIRMASS UPSTAIRS FAIRLY DRY. GFS DRIER AND EVEN MORE STABLE. GEM/GFS AND SREF SKEWING QPF MAX FURTHER NORTH AND JUST GRAZING CWA. ECMWF STILL GIVES THE ENTIRE CWA A DECENT SHOT AT PRECIP. GUID POPS HAVE DROPPED AND LEANED MORE IN THIS FAVOR GIVEN TRENDS NORTHWARD WITH QPF. STILL HAVE SOME LIKELY POPS IN THE NORTHERN CWA IN THIS CASE. TUESDAY AND TUESDAY NIGHT - CONFIDENCE...LOW TO MEDIUM STRONG SHORT WAVE ROTATES FROM THE DAKOTAS TO NORTHEAST OF LAKE SUPERIOR BY LATE TUESDAY NIGHT. BULK OF POSITIVE VORTICITY ADVECTION WILL BE TO OUR NORTH. FAIR AMOUNT OF MOISTURE RETURN WITH MODEL SURFACE DEWS PROGGD INTO THE MID 50S ACROSS SRN WI BY LATE AFTERNOON/EARLY EVENING. MOS MORE CONSERVATIVE IN THE 40S. AFTER A COOL START TEMPS WILL LIKELY REBOUND WITH 925 TEMPS REACHING 13-16C. LOCALLY DERIVED SEVERE WX PARAMETER...THE CWASP...STILL KEEPS THE MAX JUST SOUTH OF WI...BUT CLOSE CALL. IN FACT SWODY3 MATCHES CLOSE TO AXIS OF MAX CWASP. IF A NARROW RIBBON OF WARMTH AND MOISTURE CAN SNEAK INTO WI AHEAD OF THE COLD FRONT...THIS WOULD LEAD TO A CORRIDOR OF ENOUGH CAPE AHEAD OF THE FRONT. CONFIDENCE NOT GREAT AT THIS POINT ESPECIALLY WITH BRUNT OF VORT INFLUENCE TO THE NORTH AND POTENTIAL FOR BETTER INSTABILITY TO REMAIN TO OUR SOUTH. TRACK OF THE LOW AND STRENGTH OF WIND FIELDS RAISES SOME CONCERN. HOWEVER A LOOK AT BOTH THE GFS AND NAM SOUNDINGS ARE QUITE UNIMPRESSIVE. NEVERTHELESS...WILL KEEP THE CHANCE OF STORMS IN PLACE FOR TUESDAY AND TUESDAY EVENING. WEDNESDAY AND THURSDAY - CONFIDENCE...MEDIUM SHOT OF 850 COLD AIR ADVECTION WRAPS INTO THE AREA WEDNESDAY AND LINGERS INTO THURSDAY. SURFACE HIGH AND UPPER RIDGING GRADUALLY BUILD IN ACROSS THE UPPER MIDWEST THURSDAY. SHORTWAVE TROUGH SWINGS THROUGH FROM THE NORTHWEST ON WEDNESDAY THOUGH AIRMASS LOOKS TOO DRY TO SUPPORT PRECIP BASED ON BUFFY SOUNDINGS. FRIDAY AND SATURDAY - CONFIDENCE...LOW UPPER FLOW FLATTENS A BIT WITH SHORTWAVE ENERGY PROGGD INTO THE AREA ON FRIDAY. DECENT CONSISTENCY AMONGST THE MODELS ON THIS. ECMWF DEVELOPS PRECIP WITH SURFACE LOW ON SATURDAY THOUGH GFS HAS HIGH DOMINATING WITH PRECIP TO OUR SOUTH. EVEN THE ECMWF DEVELOPMENT HAS PRECIP LARGELY TO OUR WEST. GIVEN THIS POPS MAY BE TOO HIGH...BUT LOTS OF TIME YET TO FINE TUNE WITH CERTAIN CHANGES ON TIMING/STRENGTH YET TO COME. AVIATION/12Z TAFS/...VFR CLOUDS CONTINUE TO THIN AND DISSIPATE FROM THE NORTH EARLY THIS MORNING WITH AREAS OF DENSE FOG RAPIDLY DEVELOPING UPSTREAM IN THE CLEARING. KMSN MOST SUSCEPTIBLE TO A PERIOD OF DENSE FOG EARLY THIS MORNING...BUT LATEST 11-3.9 MICRON IMAGERY SHOWING SOME BINOVC OVER SOUTHEAST WI AS WELL LAST HOUR OR TWO. HENCE FOG LIKELY AT ERN TAF SITES AS WELL EARLY. HOWEVER BOUNDARY LAYER MIXING AND LINGERING HIGH LOW LEVEL RH MAY RESULT IN MORE STRATUS REDEVELOPMENT EARLY THIS MRNG VS THICKER FOG. UPSTREAM STRATUS OVER FAR NORTHERN WI INTO NRN MN BEHIND APPROACHING CDFNT NOT BEING HANDLED WELL BE SHORT TERM GUIDANCE. CONFIDENCE LOW BUT SOME OF THESE LOWER MVFR CLOUDS MAY AFFECT PORTIONS OF THE EAST LATER TODAY INTO TNGT...ESPECIALLY WITH COLD AIR SURGE OFF OF LAKE MICHIGAN. MARINE...DRY AIR CONTINUES TO FUNNEL SOUTH ACROSS LAKE MI KEEPING DENSE FOG AT BAY. LIGHT NORTH WINDS WILL TURN ONSHORE TODAY AS A WEAK COOL FRONT SLIPS SOUTH ACROSS LAKE MI AND SOUTHERN WI. A REINFORCING PUSH OF LOW LEVEL COLD AIR OVER THE WARMER LAKE WATERS TONIGHT WL RESULT IN STEEP LOW LEVEL LAPSE RATES. THESE LOW LEVEL UNSTABLE CONDITIONS OVER THE LAKE WILL ALLOW GUSTY WINDS IN EXCESS OF 22KTS TO REACH THE LAKE SURFACE OVERNIGHT. HENCE A SMALL CRAFT ADVY WL BE POSTED. A TIGHTENING PRESSURE GRADIENT AHEAD OF STRONG LOW PRESSURE IN THE NORTHERN PLAINS WILL RESULT IN GUSTY WINDS REDEVELOPING OVER THE NEARSHORE WATERS OF LAKE MI LATE MONDAY NIGHT...CONTINUING ON TUESDAY. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 10 AM CDT MONDAY FOR LMZ643>646. && $$ UPDATE...MRC TODAY/TONIGHT AND AVIATION/MARINE...MBK MONDAY THROUGH SATURDAY...COLLAR