Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/11/14


AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
1015 AM PDT SUN MAR 9 2014 .UPDATE... MODELS CONTINUE TO SLOW TIMING OF RAIN AND SNOW PUSHING SOUTHWARD AS FRONT AWAITS SHORTWAVE STILL OUT AROUND 135W. SOME LIGHT RAIN WITH SEVERAL HUNDREDTHS HAVE BEEN REPORTED IN THE SURPRISE VALLEY WITH SPRINKLES MOST AREAS FURTHER SOUTH. PRECIPITATION OVER THE FAR NORTHERN AREAS MAY EVEN LIGHTEN JUST AHEAD OF THE MAIN FRONT LATE TONIGHT BEFORE INCREASING AGAIN WITH THE FRONT. LOWERED POPS ALONG THE SIERRA FRONT AND IN THE TAHOE BASIN THROUGH THIS EVENING BUT MAINTAINED THE HIGH POPS FURTHER NORTH. ALSO, WINDS ALONG THE RIDGES ARE SLOW TO COME UP WITH THE 12Z NAM/LATEST HRRR NOT BRINGING LAKE WINDS UP DRAMATICALLY UNTIL LATER THIS EVENING. SO ADJUSTED THE LAKE WIND ADVISORY TO REMOVE THIS AFTERNOON AND EARLY EVENING. THERE MAY BE SOME LOCAL GUSTS TO 30 MPH WITH CHOP TO 2 FEET, BUT MUCH ROUGHER WATERS WILL ARRIVE AROUND MIDNIGHT AND CONTINUE INTO THE MORNING. ALL UPDATES HAVE BEEN ISSUED. HOHMANN && .PREVIOUS DISCUSSION... /ISSUED 320 AM PDT SUN MAR 9 2014/ SYNOPSIS... A PACIFIC STORM WILL BRING PERIODS OF RAIN AND HIGH ELEVATION SNOW TODAY INTO MONDAY. BREEZY CONDITIONS WILL CONTINUE THROUGH MONDAY WITH CHOPPY CONDITIONS ACROSS AREAS LAKES. FOR THE REMAINDER OF NEXT WEEK, DRY CONDITIONS ARE EXPECTED WITH TEMPERATURES BELOW AVERAGE TUESDAY RISING TO ABOVE AVERAGE BY LATE WEEK. SHORT TERM... PRECIPITATION IS WORKING ITS WAY ACROSS NORTHERN CALIFORNIA AS AN EASTERN PACIFIC TROUGH GUIDES SUBTROPICAL MOISTURE ACROSS THE PACIFIC NORTHWEST. MOST PRECIPITATION TODAY WILL BE CONFINED MAINLY NORTH OF THE TAHOE BASIN INTO WESTERN LASSEN COUNTY. HIGH SNOW LEVELS TODAY (>8000 FT) SHOULD KEEP PRECIPITATION AS RAINFALL ACROSS MOST PASSES WITH A FEW TENTHS OF RAINFALL ACCUMULATION POSSIBLE ACROSS FAR NORTHWESTERN LASSEN COUNTY. WINDS WILL ALSO INCREASE AS THE UPPER TROUGH APPROACHES. THIS WILL PICK UP WINDS ACROSS THE RIDGES WITH 700MB WINDS INCREASING BETWEEN 30-40KTS. THIS MAY CREATE SOME BREEZY CONDITIONS PARTICULARLY ACROSS NORTHERN WASHOE COUNTY AND THE SURPRISE VALLEY WHERE GUSTS UP TO 40 MPH ARE POSSIBLE. HAVE ISSUED A LAKE WIND ADVISORY FOR LAKE TAHOE BEGINNING THIS AFTERNOON THROUGH MONDAY WITH GUSTY CONDITIONS POSSIBLE AS WINDS ALOFT INCREASE AND MIXING ENHANCES. HAVE DELAYED TIMING WITH PRECIPITATION ACROSS THE TAHOE BASIN AS MODELS HAVE SLOWED THE TROUGHS PROGRESSION AND PROVIDE A QUICK SHOT OF PRECIP WITH THE PASSAGE OF A COLD FRONT LATE MONDAY MORNING INTO EARLY AFTERNOON. THE FRONT WILL LOWER SNOW LEVELS TO AROUND 6000-6500 FEET DURING THIS TIME AND MAY ALLOW A MIX OF RAIN AND SNOW TO OCCUR NEAR LAKE LEVEL WITH A SLUSHY INCH OF ACCUMULATION POSSIBLE. HAVE ALSO LOWERED QPF ACROSS THE CREST FROM TAHOE SOUTH INTO MONO COUNTY. HIGHEST ACCUMULATIONS OF 2-4 INCHES POSSIBLE ABOVE 8000 FEET WITH AROUND AN INCH ACROSS NORTHERN MONO COUNTY. NOT MUCH MEANINGFUL RAIN ACCUMULATION EXPECTED ACROSS WESTERN NEVADA WITH A FEW HUNDREDTHS POSSIBLE ACROSS RENO/CARSON WITH HIGHER AMOUNTS (A FEW TENTHS) POSSIBLE ACROSS NORTHERN WASHOE AND PERSHING COUNTY WHERE BETTER DYNAMICS, MOISTURE, AND INSTABILITY WILL BE IN PLACE. WINDS WILL REMAIN BREEZY THROUGH THE DAY MONDAY WITH CHOPPY CONDITIONS EXPECTED ACROSS BOTH LAKE TAHOE AND PYRAMID LAKE. WINDS BECOME NORTHERLY BEHIND THE FRONT RESULTING IN TEMPERATURES ONLY IN THE LOW 50S ACROSS WESTERN NEVADA AND LOWER 40S FOR SIERRA VALLEYS. WINDS REMAIN BREEZY AND CONTINUE TO SHIFT NORTHEASTERLY THROUGH THE AFTERNOON AS THE SURFACE HIGH SETTLES ACROSS NEVADA. THIS MAY ALSO PRODUCE CHOPPY CONDITIONS ACROSS TAHOE PARTICULARLY ACROSS WESTERN SHORES WITH THE EAST GRADIENT IN PLACE. FUENTES LONG TERM...WEDNESDAY THROUGH SATURDAY... SURFACE HIGH PRESSURE WILL REMAIN OVER THE GREAT BASIN ON WEDNESDAY KEEPING TEMPERATURES NEAR NORMAL, ALTHOUGH RIDGING IS STARTING TO REBUILD ALOFT OVER THE WESTERN STATES. EAST WINDS WILL CONTINUE AGAIN ON WEDNESDAY, ALTHOUGH WITH THE PRESSURE GRADIENTS STARTING TO RELAX, THE WINDS WILL BE LESS ON WEDNESDAY THAN TUESDAY. THE UPPER RIDGE WILL CONTINUE TO BUILD OVER THE WEST THROUGH THE WEEK WITH DRY CONDITIONS. WEAK SHORTWAVE ENERGY MOVING THROUGH THE NORTHERN ROCKIES WILL KEEP TEMPERATURES FROM RISING MORE THAN A COUPLE DEGREES EACH DAY. BY NEXT WEEKEND HOWEVER, SOUTH WINDS RETURN AND TEMPERATURES MAY REACH INTO THE LOW 70S IN WESTERN NEVADA. HOON AVIATION... A STORM ARRIVING LATE TODAY WILL BRING RAIN TO WESTERN NV AND RAIN AND HIGH ELEVATION SNOW TO THE SIERRA. TERMINALS LIKELY TO BE AFFECTED WILL BE FROM THE TAHOE BASIN NORTHWARD. HIGH CONFIDENCE FOR MODERATE PRECIPITATION ALONG WITH PERIODS OF MVFR/IFR CIGS/VSBYS FOR LATE TONIGHT AND MONDAY MORNING. SNOW LEVELS SHOULD REMAIN ABOVE 7000 FEET THROUGH TONIGHT BUT MAY DROP TO NEAR LAKE LEVEL AFTER FRONTAL PASSAGE MONDAY MORNING. LOW CONFIDENCE IN SNOW ACCUMULATIONS AT KTRK/KTVL...BUT LIGHT SLUSHY ACCUMULATIONS MAY BE POSSIBLE BY MONDAY MORNING DEPENDING ON THE TIMING OF SNOW LEVELS DROPPING. TURBULENCE...ICING...AND GUSTY WINDS ARE ALSO POSSIBLE TONIGHT AND MONDAY MORNING. WEISHAHN/HOON && .REV WATCHES/WARNINGS/ADVISORIES... NV...LAKE WIND ADVISORY FROM 10 PM THIS EVENING TO 2 PM PDT MONDAY FOR LAKE TAHOE IN NVZ002. CA...LAKE WIND ADVISORY FROM 10 PM THIS EVENING TO 2 PM PDT MONDAY FOR LAKE TAHOE IN CAZ072. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
354 AM PDT Sun Mar 9 2014 .Synopsis... A stream of Pacific moisture will bring precipitation to the region today and early Monday, especially for areas north of I-80. Breezy winds are possible Tuesday. Dry and mild conditions return for the remainder of the week. && Discussion... A 1.25-1.5" precipitable water plume (per latest satellite estimates) is on track to bring precipitation to NorCal next 36 hours. Areas north of I-80 will see the most precip with periods of rain today into early tomorrow, while areas south may not see anything until later tonight. At the surface, recent KSMF aircraft soundings indicate a very dry layer persisting around 800mb. One would expect precip aloft to have a tough time reaching the surface given this dry layer, yet light rain has been reported tonight from around Yuba City northward, indicating more saturated profiles north of KSMF. High-res models have had a tough time handling this situation as none of them are indicating any Valley precip until later today (although the HRRR has trended wetter in recent runs). Meanwhile, the latest radar mosaic shows this early round of precip waning offshore, with the more focused precip associated with a frontal band much further north. All this makes for a complicated precip forecast today from Redding south. Have opted for a slight chance of rain from Sac vicinity northward, with better chances in the Redding/Red Bluff area and a good bet over the mountains. The action picks up late today into tonight as the trough axis moves inland and an associated upper-level jetstreak brushes the region. Closer to the surface, a cold front (most evident in frontogenesis plots from 850-700mb) pushes southeastward across NorCal with the moisture plume at its leading edge. The jet position puts our area in the favorable right entrance region, while the frontogenesis provides extra dynamics. Meanwhile, the NAM is showing some marginal instability close to the surface associated with the front. Have thus included a slight chance of thunderstorms tonight, with the timing matching expecting frontal passage. The front is currently expected to reach the North Sac Valley around 3z-9z and the I-80 corridor by 9-15z. While this timing is not the best for thunderstorms, our recent convective event a few days ago demonstrated that frontal convection can still go on overnight. Several difference worth noting between this event and the last is the preceding surface dewpoints will not be as high and surface convergence will not be as strong, making the current event less favorable for convection compared to the last. Precipitation across the area should come to an end quickly by mid-day Monday as drier air moves in and developing subsidence aloft works against any lingering showers. Only lingering chance could be some orographically-enhanced showers over the mountains. Due to the subtropical origin of the moisture plume, snow levels will be quite high and above Sierra passes today. Snow levels will quickly lower behind the cold front to around 5500 to 6000 ft by mid-day tomorrow, although precip will be winding down by that point. All told, we`re looking at 2-6 inches of snow near Sierra pass levels with up to 10 inches over the higher peaks. Lower elevations in the mountains can expect 1-2+ inches of rain, with the Feather River area and parts of Shasta County likely seeing the most. In the Valley, 0.5-1" is expected in the North Sac Valley, tapering to a quarter inch or less from Sacramento southward. Tight surface pressure gradients will develop on the backside of the trough by Tuesday along with strong winds around 700mb. This would bring gusty north winds to the north and west sides of the Sacramento Valley, strong east winds for the west slope of the Northern Sierra, and very strong winds to mountain ridgetops. -DVC .Extended Discussion (Thursday through Sunday) Increasing confidence that high pressure will strengthen across the region later this week and next weekend. This will result in dry weather with very mild temperatures for the interior of NorCal. Look for Central Valley highs to warm through the 70s into the lower 80s by the weekend with mountain readings warming from the 50s and 60s into the 60s and 70s. && .Aviation... Little change in the pattern expected through 06Z Monday as moisture continues to stream up into NorCal from the southwest. VFR conditions will continue with CIGS generally 070-100 with sctd -SHRA mainly N of I-80. Front moves S aft 06Z with widespread MVFR conditions developing with IFR conditions over higher terrain. && .STO Watches/Warnings/Advisories... None. && $$
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
353 AM PDT Sun Mar 9 2014 .Synopsis... A stream of Pacific moisture will bring precipitation to the region today and Monday, especially for areas north of I-80. Breezy winds are possible Tuesday. Dry and mild conditions return for the remainder of the week. && Discussion... A 1.25-1.5" precipitable water plume (per latest satellite estimates) is on track to bring precipitation to NorCal next 36 hours. Areas north of I-80 will see the most precip with periods of rain today into early tomorrow, while areas south may not see anything until later tonight. At the surface, recent KSMF aircraft soundings indicate a very dry layer persisting around 800mb. One would expect precip aloft to have a tough time reaching the surface given this dry layer, yet light rain has been reported tonight from around Yuba City northward, indicating more saturated profiles north of KSMF. High-res models have had a tough time handling this situation as none of them are indicating any Valley precip until later today (although the HRRR has trended wetter in recent runs). Meanwhile, the latest radar mosaic shows this early round of precip waning offshore, with the more focused precip associated with a frontal band much further north. All this makes for a complicated precip forecast today from Redding south. Have opted for a slight chance of rain from Sac vicinity northward, with better chances in the Redding/Red Bluff area and a good bet over the mountains. The action picks up late today into tonight as the trough axis moves inland and an associated upper-level jetstreak brushes the region. Closer to the surface, a cold front (most evident in frontogenesis plots from 850-700mb) pushes southeastward across NorCal with the moisture plume at its leading edge. The jet position puts our area in the favorable right entrance region, while the frontogenesis provides extra dynamics. Meanwhile, the NAM is showing some marginal instability close to the surface associated with the front. Have thus included a slight chance of thunderstorms tonight, with the timing matching expecting frontal passage. The front is currently expected to reach the North Sac Valley around 3z-9z and the I-80 corridor by 9-15z. While this timing is not the best for thunderstorms, our recent convective event a few days ago demonstrated that frontal convection can still go on overnight. Several difference worth noting between this event and the last is the preceding surface dewpoints will not be as high and surface convergence will not be as strong, making the current event less favorable for convection compared to the last. Precipitation across the area should come to an end quickly by mid-day Monday as drier air moves in and developing subsidence aloft works against any lingering showers. Only lingering chance could be some orographically-enhanced showers over the mountains. Due to the subtropical origin of the moisture plume, snow levels will be quite high and above Sierra passes today. Snow levels will quickly lower behind the cold front to around 5500 to 6000 ft by mid-day tomorrow, although precip will be winding down by that point. All told, we`re looking at 2-6 inches of snow near Sierra pass levels with up to 10 inches over the higher peaks. Lower elevations in the mountains can expect 1-2+ inches of rain, with the Feather River area and parts of Shasta County likely seeing the most. In the Valley, 0.5-1" is expected in the North Sac Valley, tapering to a quarter inch or less from Sacramento southward. Tight surface pressure gradients will develop on the backside of the trough by Tuesday along with strong winds around 700mb. This would bring gusty north winds to the north and west sides of the Sacramento Valley, strong east winds for the west slope of the Northern Sierra, and very strong winds to mountain ridgetops. -DVC .Extended Discussion (Thursday through Sunday) Increasing confidence that high pressure will strengthen across the region later this week and next weekend. This will result in dry weather with very mild temperatures for the interior of NorCal. Look for Central Valley highs to warm through the 70s into the lower 80s by the weekend with mountain readings warming from the 50s and 60s into the 60s and 70s. && .Aviation... Little change in the pattern expected through 06Z Monday as moisture continues to stream up into NorCal from the southwest. VFR conditions will continue with CIGS generally 070-100 with sctd -SHRA mainly N of I-80. Front moves S aft 06Z with widespread MVFR conditions developing with IFR conditions over higher terrain. && .STO Watches/Warnings/Advisories... None. && $$
AREA FORECAST DISCUSSION
NWS TAUNTON MA
719 PM EDT MON MAR 10 2014 .SYNOPSIS... AN ACTIVE POLAR JET STREAM WILL BRING ANOTHER BOUT OF LIGHT WINTRY PRECIPITATION TONIGHT TO THE REGION...ESPECIALLY NORTHERN MASSACHUSETTS AND SOUTHWEST NEW HAMPSHIRE. THEREAFTER THE POLAR JET LIFTS NORTHWARD ALLOWING MILDER WEATHER TO OVERSPREAD THE REGION TUESDAY WITH TEMPERATURES RISING INTO THE 50S! A POWERFUL AREA OF LOW PRESSURE THEN DEVELOPS WEDNESDAY AND TRACKS OVER OR NEAR SOUTHERN NEW ENGLAND...BRINGING HEAVY RAIN AND SNOW TO THE AREA. STILL TOO EARLY TO DETERMINE EXACTLY HOW MUCH RAIN AND SNOW WILL FALL. DRY BUT BITTERLY COLD WEATHER BRIEFLY RETURNS LATER THURSDAY INTO FRIDAY. MUCH WARMER WEATHER IS LIKELY TO BEGIN NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 715 PM UPDATE... HAVE TRIMMED THE SOUTHWARD EXTENT OF ANY CHANCES OF PRECIPITATION TONIGHT. 18Z NAM AND LATEST RAP CONFINE PRECIPITATION TO SOUTHERN NH AND FAR NORTHEAST MA. THIS FITS WITH RADAR TRENDS. SLOWED DOWN POPS UNTIL AFTER 01Z BUT THEN SPED UP DEPARTURE SUCH THAT IT IS OFF THE COAST BY APPROX 08Z. OTHERWISE...NO CHANGES TO FORECAST. PREVIOUS DISCUSSION... ANOTHER BAND OF ISENTROPIC LIFT ARRIVES THIS EVENING. THE MAJORITY OF THE DYNAMICS SHOULD REMAIN TO OUR NORTH...SO ONLY EXPECTING SCATTERED SNOW OR RAIN SHOWERS. CONDITIONS EXPECTED TO DRY/CLEAR OUT AFTER MIDNIGHT ACROSS SOUTHERN NEW ENGLAND. TEMPERATURES WILL BE TRICKY...AND LARGELY DEPENDENT UPON HOW QUICKLY THE SKIES CLEAR. AT THIS POINT...THINKING IS THERE WILL BE ENOUGH CLOUDS LINGERING TO PREVENT IDEAL RADIATIONAL COOLING CONDITIONS. STAYED CLOSE TO MOS CONSENSUS FOR MIN TEMPERATURES OVERNIGHT. TEMPERATURES RIGHT AROUND FREEZING DOES OPEN THE DOOR FOR SOME ICING POTENTIAL...PARTICULARLY ACROSS PORTIONS OF NORTHERN MA...WHERE THE 925 MB TEMPERATURES ARE ABOVE FREEZING. THIS IS A LOW PROBABILITY AT THIS POINT...SO NOT PLANNING ANY ADVISORIES AT THIS TIME. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... TUESDAY... MAINLY DRY WITH PLENTY OF SUNSHINE. AS MIXING OCCURS...THE WESTERLY DOWNSLOPING WINDS WILL ALLOW FOR GUSTS TO INCREASE NEAR 20 MPH AND DEWPOINTS DROP INTO THE 20S. THIS COULD TURN INTO A POTENTIAL FIRE WEATHER DAY...ALL DEPENDS ON HOW DEEP THE MIXING GETS. TUESDAY NIGHT... INCREASING CLOUDS ASSOCIATED WITH A BROADER...BUT WEAKER...AREA OF ISENTROPIC LIFT TUESDAY NIGHT. LOW LEVELS LOOK FAIRLY DRY UNTIL RATHER LATE IN THE NIGHT. AT THIS POINT...THINKING PRECIPITATION WILL HOLD OFF UNTIL LATER IN THE DAY WEDNESDAY. STAYED CLOSE TO MOS CONSENSUS FOR THESE PERIODS...BUT DID TRY TO ACCOUNT FOR SOME RECENT BIASES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... *** TRENDING WARMER AND WETTER FOR WED/WED NIGHT STORM *** *** TYPICAL LARGE TEMPERATURE SWINGS FOR MARCH THIS PERIOD *** MODEL GUIDANCE AND SYNOPTIC OVERVIEW... ALL MODEL GUIDANCE INCLUDING THE 12Z GFS/NAM/UKMET/GEFS/ECMWF AND ECENS HAVE ALL TRENDED NORTH WITH THE SURFACE LOW NOW AND SHOWING GOOD CLUSTERING AROUND A TRACK ALONG THE COASTAL PLAIN /I95 CORRIDOR/ OF SOUTHERN NEW ENGLAND WED-THU. THIS IS A WARMER SOLUTION THAN SEEN IN PREVIOUS MODEL RUNS. WHILE THIS IS THE MORE LIKELY TRACK/SCENARIO AT THIS TIME...NOT EXPECTING MAJOR CHANGES IN FUTURE MODEL RUNS BUT KEEP IN MIND MODEL PROJECTIONS AT 60+ HRS RARELY VERIFY EXACTLY. THUS NEED TO KEEP THE DOOR OPEN FOR SLIGHT COLDER OR WARMER SOLUTIONS IN LATER MODEL RUNS. THIS DIRECTLY IMPACTS THE EVOLUTION OF THE RAIN-SNOW AND ACCOMPANYING SNOWFALL FORECAST. THUS STILL TOO EARLY TO LOCK INTO PRECISE SNOW TOTALS OR TRANSITION TIMES. THE TWO PACKETS OF JET ENERGY THAT WILL MERGE AND RESULT IN EXPLOSIVE CYCLOGENESIS OVER THE NORTHEAST ARE CURRENTLY COMING INTO THE PACIFIC NORTHWEST AND THE OTHER PACKET OVER NORTHWEST CANADA AND ALASKA...NOT A DATA RICH AREA. THE AMPLITUDE OF THE TRAILING JET ENERGY OVER NORTHWEST CANADA AND ALASKA WILL BE KEY...AS MODELS AGREE THIS FEATURE WILL PROVIDE ENOUGH AMPLITUDE TO BACK THE MID LEVEL FLOW SUFFICIENTLY FOR A STORM TRACK FARTHER NORTHWEST. AS MENTIONED ABOVE...STILL 60+ HRS OUT SO FOR NOW WILL BLEND ALL 12Z MODEL GUIDANCE. HOWEVER WE WILL STAY AWAY FROM THE 12Z NAM THERMAL FIELDS WHICH ARE DISPLAYING THEIR TYPICAL COLD BIAS AT THIS LONGER TIME RANGE. SENSIBLE WEATHER DETAILS... WED/WED NIGHT... GOOD MODEL AGREEMENT THAT PRECIP OVERSPREADS THE REGION FROM WEST TO EAST...POSSIBLY HOLDING OFF UNTIL EARLY AFTERNOON OVER SOUTHEAST MA. 12Z MODEL GUIDANCE SUGGEST PRECIP MAY BEGIN AS SNOW SOMEWHERE ALONG AND NORTH OF THE MASS PIKE AND INTO SOUTHERN NH...THEN THE RAIN-SNOW LINE LIFTING NORTHWARD INTO SOUTHERN OR CENTRAL NH BEFORE CRASHING SOUTHWARD WED NIGHT AS MID LEVEL LOW MOVES EAST ACROSS THE REGION AND WRAPPING COLDER AIR SOUTHWARD. RAIN-SNOW LIKELY TO CRASH SOUTHEAST ALL THE WAY TO THE COAST. THEN ISSUE BECOMES HOW MUCH QPF IS LEFT ONCE COLD AIR ARRIVES. GFS AND ECMWF HANDLE THE EVOLVING COMMA HEAD DIFFERENTLY...SO LOW CONFIDENCE ON HOW MUCH SNOW WILL FALL ON THE BACKSIDE. BASED ON THE CURRENT STORM TRACK MOST CONFIDENCE OF 6"+ ACROSS NORTHWEST INTO SOUTHWEST NH. THAT IS A COMBINATION OF SNOW ON THE FRONT END WED...MIXED PRECIP WED EVENING THEN BACK TO SNOW OVERNIGHT WED NIGHT INTO EARLY THU. THUS WINTER STORM WATCH REMAINS IN EFFECT FOR THIS AREA. WAS TEMPTED TO BRING THE WATCH FARTHER SOUTH INTO NORTHERN WORCESTER COUNTY AND NORTHWEST MIDDLESEX...BUT GIVEN PTYPE ISSUES/UNCERTAINTY IN EVOLUTION IN COMMA HEAD SNOWS AND EVENT STILL 48-60HRS OUT PLENTY OF TIME TO IRON OUT THESE DETAILS. LESS SNOW SOUTHWARD BUT A RISK OF A WINTRY MIX FOR A TIME WED FROM NORTHERN CT-RI TO THE MASS PIKE FOLLOWED BY A PERIOD OF WRAP AROUND SNOW WED NIGHT INTO THU AM. ELSEWHERE ACROSS MUCH OF CENTRAL- SOUTHERN RI AND SOUTHEAST MA LITTLE IF ANY SNOWFALL EXPECTED ON THE FRONT END WED WITH PERIODS OF HEAVY RAIN MORE OF A CONCERN. RISK OF URBAN POOR DRAINAGE FLOODING AS PWATS CLIMB TO +2 STD ABOVE CLIMO ALONG WITH THE CHANCE OF TSTMS AS NOSE OF DRY SLOT APPROACHES /THETA-E DECREASING WITH HEIGHT/ LATE WED-WED NIGHT. WILL LEAVE TSTMS OUT OF THE FORECAST GIVEN THE TIME RANGE. WED NIGHT COULD BE SOME CONCERN REGARDING A FLASH FREEZE GIVEN STANDING WATER FOLLOWED BY VERY STRONG COLD AIR ADVECTION. THU/FRI...SOME COMMA HEAD SNOWS POSSIBLE THU MORNING. THEN FOCUS BECOMES ANOMALOUS COLD AIR ADVECTION WITH ENSEMBLE 850 AND 925 MB TEMP ANOMALIES ON THE ORDER OF -2 STD FROM CLIMO! CORE OF THE COLD AIR IS OVER NEW ENGLAND 06Z-12Z FRI. GUSTY NW WINDS WILL PROVIDE BITTERLY COLD WIND CHILLS. LOOKING AT A SUPERBLEND OF ALL MODEL GUIDANCE FOR LOWS THU NGT/FRI AM...WE ARE WITHIN A FEW DEGS OF RECORD LOWS AT BOSTON/PROVIDENCE/BRADLEY AND WORCESTER! WEEKEND...LIKELY MILDER SAT /40S TO NEAR 50 POSSIBLE!/ AS ENSEMBLES HAVE LOW PRES TRACKING ACROSS SOUTHEAST CANADA. ENSEMBLES SUGGEST ATTENDING FRONTAL PASSAGE SHOULD BE MAINLY DRY CROSSING THE AREA SOMETIME LATER SAT/SAT NGT/EARLY SUN. TRENDING COOLER BEHIND THE FRONT FOR SUNDAY. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE. THROUGH 00Z...CONDITIONS IMPROVING TO VFR ACROSS CAPE AND ISLANDS. TONIGHT...VFR EXCEPT BRIEF PERIOD OF MVFR WITH A CHANCE OF A SNOW SHOWER IN SOUTHERN NH AND FAR NORTHEAST MA. TUESDAY...VFR AND DRY ALONG WITH A MODEST NW WIND. TUESDAY NIGHT...VFR WITH INCREASING SKY COVER. POTENTIAL MVFR IN LIGHT SNOW LATE...ESPECIALLY IN THE CT VALLEY AND EAST SLOPES OF THE BERKSHIRES. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE CONFIDENCE. WED...MVFR TO START THEN LOWERING TO IFR AND POSSIBLY LIFR IN HEAVY RAIN MOST OF CT/RI AND SOUTHEAST MA INCLUDING BOSTON WITH HEAVY SNOW NORTHWEST MA AND SOUTHWEST NH. PRELIMINARY SNOWFALL FORECAST... BOS...1-2" POSSIBLE WED NIGHT/THU AM PVD...1-2" POSSIBLE WED NIGHT/THU AM BDL...1-2" POSSIBLE WED NIGHT/THU AM ORH...3-6" POSSIBLE WED/THU MHT...5-8" POSSIBLE WED/THU THU...IFR EARLY IMPROVING TO MVFR-VFR. GUSTY NW WINDS UP TO 35 KT POSSIBLE. FRI/SAT...VFR AND DRY WEATHER LIKELY. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. HIGH CONFIDENCE THROUGH TONIGHT...MODERATE CONFIDENCE ON SEAS FOR TUESDAY AND TUESDAY NIGHT. INCREASING SOUTHWEST WINDS AHEAD OF A COLD FRONT...SHIFT WEST DURING TUESDAY. WHILE MAX WIND SPEEDS ARE EXPECTED TO REMAIN BENEATH 25 KT...THERE COLD BE A STRONG ENOUGH FETCH FOR A SUFFICIENT PERIOD OF TIME TO GENERATE 5 FT SEAS ACROSS THE OUTER COASTAL WATERS LATE TONIGHT INTO TUESDAY. IT IS MARGINAL...BUT WILL ISSUE A SMALL CRAFT ADVISORY LATER THIS AFTERNOON FOR THE SOUTHERN OUTER COASTAL WATERS. OUTLOOK...WEDNESDAY THROUGH SATURDAY... WED...INTENSIFYING LOW PRES TRACKS ALONG THE SOUTHERN NEW ENGLAND COAST. LOW VSBY IN FOG AND HEAVY RAIN. THU...GALE CENTER EXITS SOUTHEAST MA INTO THE GULF OF MAINE WITH NW GALES LIKELY. LIGHT FREEZING SPRAY LIKELY WITH A LOW RISK OF MODERATE FREEZING SPRAY. FRI/SAT...WINDS EASE FRI BUT THEN SHIFT TO THE SW SAT AND BECOME GUSTY AS LOW PRES TRACKS ACROSS SOUTHEAST CANADA. && .TIDES/COASTAL FLOODING... NO FLOODING EXPECTED GIVEN RELATIVELY LOW ASTRO TIDES AND NOT MUCH WIND AND SURGE ANTICIPATED AS TRACK OF SURFACE LOW DIRECTLY OVER OR VERY CLOSE TO THE REGION. && .CLIMATE... NEAR RECORD COLD POSSIBLE THU NIGHT INTO EARLY FRIDAY. HERE ARE RECORD LOW TEMPERATURES FOR FRIDAY MARCH 14TH... BOSTON.......12/1896...FORECAST LOW...15 PROVIDENCE...12/1948...FORECAST LOW...14 BRADLEY ARPT..7/1948...FORECAST LOW...10 WORCESTER.....4/1948...FORECAST LOW...8 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY MORNING FOR MAZ002-003-008-009. NH...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY MORNING FOR NHZ011-012-015. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 5 AM TO 2 PM EDT TUESDAY FOR ANZ254>256. && $$ SYNOPSIS...NOCERA NEAR TERM...BELK/GAF SHORT TERM...BELK LONG TERM...NOCERA AVIATION...BELK/NOCERA/GAF MARINE...BELK/NOCERA TIDES/COASTAL FLOODING...STAFF CLIMATE...STAFF
AREA FORECAST DISCUSSION
NWS POCATELLO ID
633 PM MDT MON MAR 10 2014 .UPDATE...THE BACK OF THE STORM SYSTEM IS PASSING THROUGH THE CENTRAL MOUNTAINS. TEMPERATURES ARE COLLING WITH SNOW LEVEL JUST BEGINNING TO DROP TO AROUND 7700 TO 7900 FEET ELEVATION. HOWEVER...SNOW ACCUMULATION THE REMAINDER OF THE NIGHT WILL BE LIMITED TO AN INCH OR SO. THEREFORE THE WINTER STORM WARNING WAS ALLOWED TO EXPIRE IN THE CENTRAL MOUNTAINS. THE FLOOD WATCH IN THE KETCHUM AND HAILEY AREA WAS ALSO ALLOWED TO EXPIRE. LIMITED WATER RISES WERE OBSERVED ON SMALL STREAMS...ESPECIALLY THE EAST FORK OF THE BIG WOOD RIVER...BUT THIS WAS LESS THE WATER LEVELS OBSERVED A COUPLE OF DAYS AGO AND NO FLOODING HAS BEEN REPORTED. REMOTE GAGES REPORT WATER LEVELS ARE LEVELING OFF. RS && .PREV DISCUSSION... /ISSUED 115 PM MDT MON MAR 10 2014/ SHORT TERM...TONIGHT THROUGH WEDNESDAY. A STRONG STORM CONTINUES TO SLOWLY PUSH EAST ACROSS THE WEST. AS THE SYSTEM MOVES OVER IDAHO...IT WILL ACTUALLY BEGIN TO DIG MORE SOUTH AND SETTLE OVER SOUTHERN UTAH AND NEVADA BY TOMORROW AFTERNOON. SNOW LEVELS WILL CONTINUE TO FALL AS A COLD FRONT WORKS ACROSS THE AREA...AND FALL TO THE VALLEY FLOORS AREAWIDE BY MORNING. STRONG WINDS WILL CONTINUE IN THE HIGHER ELEVATIONS AND ALSO ACROSS THE SNAKE PLAIN THIS EVENING. WE ARE ALREADY SEEING LOCALIZED GUSTS IN EXCESS OF 60MPH ACROSS THE PLAIN...BUT MOST GUSTS WILL NOT EXCEED 55MPH. THE WIND ADVISORY REMAINS IN EFFECT FOR THE SNAKE PLAIN UNTIL 9PM. HOWEVER...THERE IS SOME INDICATION THAT WE MAY NEED TO EXTEND THAT UNTIL MIDNIGHT AND PERHAPS EXTEND IT INTO THE SOUTHERN HIGHLANDS ESPECIALLY AS THE WINDS SWITCH TO THE NORTHWEST. IN TERMS OF PRECIPITATION...THE PATTERN BECOMES RATHER COMPLEX THIS EVENING. IN TERMS OF THE MOUNTAINS...WE WILL SEE TWO DISTINCT AREAS OF ENHANCED MOISTURE. THE FIRST IS ACROSS THE UPPER SNAKE HIGHLANDS AND SOUTHWARD TOWARD BEAR LAKE. THE OTHER IS IN NORTHWEST FLOW ACROSS CENTRAL MOUNTAINS FROM CHALLIS TO GALENA SUMMIT. THE BIGGER AMOUNTS OVERALL WILL FALL OVER THE EAST. THE THIRD AREA IS A COMBINATION OF CONVERGENCE AND UPSLOPE. BY MORNING...AN AREA OF CONVERGENCE WILL LIE ACROSS THE SNAKE PLAIN NORTH AND EAST OF CRATERS TO POCATELLO LINE. UPSLOPE WILL ENHANCE THIS MOISTURE BAND ACROSS THE BENCHES AND ADJACENT MOUNTAINS FROM NEAR ST. ANTHONY TO AROUND POCATELLO. SNOW LEVELS WILL HOVER AROUND 4500-5000FT SO THESE AREAS WILL SEE AT LEAST MIX DOWN LOW AND ALL SNOW ABOVE THE BENCHES. IN TERMS OF ADDITIONAL PRECIPITATION OVERNIGHT...THE MOUNTAINS WILL SEE 0.10-0.20 INCHES ACROSS THE WEST AND 0.20-0.50 INCHES IN THE EAST. SNOWFALL AMOUNTS WILL BE A TRACE TO 3 INCHES IN THE MOUNTAINS. SOME BLOWING/DRIFTING IS POSSIBLE IN THE MOUNTAINS BUT WILL NOT BE WIDESPREAD IT APPEARS. WE MAY SEE A DUSTING ACROSS THE SNAKE PLAIN ESPECIALLY EAST OF I-15 BUT IT WILL NOT STICK AROUND LONG. IN TERMS OF WINTER AND FLOOD HEADLINES...WE WILL LET ALL WATCHES AND WARNINGS RIDE AND WILL LET THE EVENING SHIFT DECIDE IF ANYTHING NEEDS TO BE EXTENDED. BY TUESDAY AFTERNOON...WE WILL SEE ANY RAIN OR SNOW CONFINED TO AROUND BEAR LAKE AND DRIER AIR AND HIGH PRESSURE BUILDS INTO IDAHO. WE WILL SEE GUSTY NORTH TO NORTHEAST WINDS ACROSS THE ENTIRE AREA. IT WILL BE A BIT COOLER TOMORROW AS WELL. TUESDAY NIGHT AND WEDNESDAY WILL BE VERY DRY. WITH THE DRY AREA MOVING IN...THIS SHOULD ALLOW FOR A VERY CHILLY NIGHT ACROSS THE AREA AND A DECENT WARMUP ON WEDNESDAY. LOWS WILL LIKELY DROP INTO THE SINGLE DIGITS FOR HIGHER VALLEYS AND ISLAND PARK...WITH 10S AND 20S ELSEWHERE. GUIDANCE ACTUALLY POINTS TO EVEN COLDER TEMPERATURES BUT FOR NOW TRENDED ONLY PARTIALLY THAT DIRECTION. HIGHS BOUNCE BACK INTO 40S/LOWS 50S IN THE VALLEYS AND LOW/MID 30S AT RIDGETOP. KEYES LONG TERM...THU NIGHT THROUGH NEXT MON NIGHT. LONGWAVE PATTERN INDICATES A HIGH AMPLITUDE RIDGE TO THE WEST OF IDAHO THAT SLOWLY DE-AMPLIFIES AND SHIFTS TO THE COAST STARTING SAT NIGHT. THERE ARE A COUPLE OF WEAK TROUGHS THAT MOVE DOWN THE BACKSIDE OF THE RIDGE...THE MOST LIKELY ONE TO AFFECT THE FORECAST AREA IS A FRI NIGHT/SAT SHORTWAVE. ZERO TO LITTLE EFFECT IS EXPECTED SOUTH OF POCATELLO...AND ONLY LITTLE EFFECT NORTH OF THIS. THE MAIN FORECAST PROBLEM IS HOW WARM IT WILL GET...WITH THE ECMWF BEING COLDER AND CLOUDIER. HAVE SPLIT THE DIFFERENCE...WHICH GETS LARGE BEYOND THE FRI NIGHT TROUGH. NO REAL SIGNIFICANT WIND WITH TEMPS GENERALLY ABOVE SEASONAL NORMALS. MESSICK AVIATION...WIND HAVING A HARD TIME DEVELOPING...AND SUN VALLEY JUST BELOW FIELD MINIMUMS. LOWEST CIGS EXPECTED WITH FRONTAL PASSAGE DURING THE MID- TO LATE AFTERNOON. FOR ALL AIRDROMES. LOWEST CIGS EXPECTED ARE MARGINAL VFR. HRRR GUIDANCE OF LATE NOW SUGGESTS STRONG WINDS SHORTLY AFTER 11/01Z IN THE KPIH AREA. SHOULDN`T BE MUCH OF A PROBLEM SINCE THEY ARE ALIGNED WITH THE RUNWAY. SKIES SHOULD CLEAR DURING THE LATE EVENING HOURS. MESSICK HYDROLOGY...MODERATE TO HEAVY RAINFALL BELOW 6500 FEET COMBINED WITH MELTING SNOW WILL CREATE AN INCREASED THREAT OF FLOODING FOR SMALL STREAMS AND LOW LYING AREAS IN THE BIG AND LITTLE WOOD RIVER REGION AND THE UPPER SNAKE HIGHLANDS FOR THE NEXT SEVERAL HOURS. THESE AREAS INCLUDE THE CITIES OF KETCHUM...HAILEY... ASHTON AND ST ANTHONY. A FLOOD WATCH REMAINS IN EFFECT FOR THESE AREAS. FLOODING IS NOT EXPECTED FOR THE MAIN STEM RIVERS AT THIS TIME. WYATT && .PIH WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 9 PM MDT THIS EVENING IDZ017-020-021. FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT BELOW 6500 FEET FOR THE IDZ019. WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT ABOVE 7000 FEET FOR THE IDZ019. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
202 PM EDT SUN MAR 9 2014 .UPDATE... THE LONG TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 315 AM EST SUN MAR 9 2014 ANOTHER WARMUP IS IN STORE EARLY NEXT WEEK UNDER THE INFLUENCE OF SOUTHWEST FLOW WITH AFTERNOON HIGHS IN THE 50S AND 60S MONDAY AND TUESDAY ON TAP. THEN...A PLAINS LOW PRESSURE SYSTEM WILL BRING RAIN AND THEN SNOW TO CENTRAL INDIANA MIDWEEK ALONG WITH COOLER TEMPERATURES. HOWEVER...MORE WARM TEMPERATURES AND DRY CONDITIONS SHOULD RETURN NEXT WEEKEND. && .NEAR TERM /TODAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 MAIN FOCUS TODAY WILL BE ON MORNING STRATOCU AND OR PATCHY FOG WITH THE CONCENTRATION THIS AFTERNOON ON TEMPERATURES. THE RUC13 925 MILLIBAR RH PROGS SEEMED TO HAVE A GOOD HANDLE ON THE STRATOCU DECK...CURRENTLY ACROSS EASTERN ILLINOIS. IT SUGGESTS THE EASTERN EDGE OF THIS DECK WILL BE ACROSS OUR SOUTHWESTERN COUNTIES AT 12Z THIS MORNING...SO LEFT SOME SKY COVER IN THERE THROUGH MID MORNING WITH LITTLE ELSEWHERE UNTIL LATE IN THE AFTERNOON WHEN SOME HIGH CLOUDS WILL MOVE IN FROM THE UPPER MIDWEST IN THE FAST NORTHWEST FLOW ALOFT. WITH TEMPERATURES NEARING THEIR DEW POINTS AND LIGHT WINDS...WILL GO WITH PATCHY FOG THROUGH 14Z. THERE IS SOME CONCERN THE STRATOCU AND OR FOG WILL HANG AROUND LONGER THAN THAT WITH HIGH RESOLUTION SHORT TERM MODEL SOUNDINGS SHOWING A STRONG INVERSION AROUND 925 MILLIBARS. AFTER THE LOW CLOUDS AND OR FOG ARE GONE...THERE SHOULD BE SUNNY SKIES WITH MODEL TIME SECTIONS SHOWING A DRY COLUMN AND A HIGH PRESSURE RIDGE FROM THE SOUTHERN PLAINS THROUGH THE OHIO VALLEY. WITH SOUTHWEST FLOW...PREFER THE WARMER 00Z GFS MOS WHICH IS CLOSE TO 00Z CONSALL. AFTERNOON HIGHS SHOULD BE IN THE 40S WHICH IS JUST BELOW NORMAL. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 TEMPERATURES AS WELL AS CLOUD COVER WILL BE THE CHALLENGE FOR THE SHORT TERM. MODELS ARE IN GOOD AGREEMENT REGARDING THE SHORT TERM SYNOPTIC PATTERN...SO CONFIDENCE IS GOOD REGARDING A BLEND. MODELS KEEP SOUTHWEST FLOW ACROSS CENTRAL INDIANA THROUGH TUESDAY AND BUFKIT SUGGESTS MONDAY WILL BE BREEZY AS A LOW PRESSURE SYSTEM MOVES EAST ACROSS ONTARIO AND THE SURFACE HIGH SETTLES ACROSS THE GULF CREATING A STRENGTHENING SURFACE LOW PRESSURE GRADIENT ACROSS THE GREAT LAKES AND OHIO VALLEY. A FRONT SHOULD THEN SLIDE SOUTHEAST ACROSS THE AREA ON TUESDAY AS A STRONG LOW PRESSURE SYSTEM MOVES INTO THE CENTRAL PLAINS AHEAD OF AN UPPER WAVE. WITH DRY AIR IN THE LOWER LEVELS...PRECIPITATION SHOULD HOLD OFF UNTIL TUESDAY NIGHT...WHEN OVERRUNNING REALLY RAMPS UP AND ATMOSPHERE MOISTENS FROM THE TOP DOWN AS THE PLAINS LOW PRESSURE SYSTEM MOVES ACROSS KENTUCKY. MODEL TIME SECTIONS AND UPSTREAM SATELLITE AND OBS ARE IMPLYING QUITE A BIT OF CIRRUS AND POSSIBLY AC WILL BE OVER CENTRAL INDIANA THROUGH THE BULK OF THE SHORT TERM. THUS...PREFER THE 00Z ECMWF WHICH HAS MORE SKY COVER THAN ANY BLEND. DESPITE THIS...PREFER TO SIDE WITH THE WARMER 00Z GFS ONCE AGAIN AS IT HAS BEEN DOING BETTER WITH THE RECENT WARMER DAYS. ESPECIALLY PREFER THE WARMER GFS ON MONDAY WITH THE BREEZY SOUTHWEST WINDS THAT WE SHOULD SEE. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... ISSUED AT 202 PM EDT SUN MAR 9 2014 DRY WEATHER ALONG WITH A WARMING TREND IS EXPECTED DURING THIS PERIOD. IN THE WAKE OF THE PREVIOUS STORM SYSTEM THE GFS AND ECMWF BOTH DEPICT A LARGE AREA OF HIGH PRESSURE BUILDING ACROSS THE REGION. NORTHWEST FLOW IS EXPECTED TO PERSIST ALOFT...HOWEVER AS THE HIGH PUSHES EAST OF INDIANA BY THURSDAY STRONGER WARM AIR ADVECTION IS EXPECTED...ALLOWING TEMPERATURES TO RISE TO NEAR OR SLIGHTLY ABOVE NORMALS. BY SUNDAY...THE FLOW ALOFT LOOKS TO BECOME MORE ZONAL AND A STATIONARY BOUNDARY SETS UP NEAR THE OHIO RIVER. MEANWHILE THE ECMWF AND GFS BOTH EJECT AN UPPER SHORT WAVE TOWARD THE OHIO VALLEY. FOR NOW WILL INCLUDE SOME POPS AT THAT TIME...BUT CONFIDENCE REMAINS LOW ON DAY7. && .AVIATION /DISCUSSION FOR THE 091800Z TAFS/... ISSUED AT 1242 PM EDT SUN MAR 9 2014 VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD. HIGH PRESSURE STRETCHING FROM THE SOUTHERN PLAINS...ACROSS INDIANA TO WESTERN NEW YORK WILL DRIFT SLOWLY SOUTHEAST DURING THIS TAF PERIOD. WARM AIR ADVECTION ALOFT WILL CONTRIBUTE TO MID AND HIGH CLOUD CEILINGS. A GOOD LOWER LEVEL PRESSURE GRADIENT WILL PROVIDE GOOD MIXING THROUGH THE NIGHT...PREVENTING FOG AND VISIBILITY RESTRICTIONS. FORECAST SOUNDINGS AND TIME HEIGHT SECTIONS CONFIRM...SHOWING DRY LOWER LEVELS WITH UNREACHABLE CONVECTIVE TEMPERATURES. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MK NEAR TERM...MK SHORT TERM...MK LONG TERM....PUMA AVIATION...JP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1246 PM EDT SUN MAR 9 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 315 AM EST SUN MAR 9 2014 ANOTHER WARMUP IS IN STORE EARLY NEXT WEEK UNDER THE INFLUENCE OF SOUTHWEST FLOW WITH AFTERNOON HIGHS IN THE 50S AND 60S MONDAY AND TUESDAY ON TAP. THEN...A PLAINS LOW PRESSURE SYSTEM WILL BRING RAIN AND THEN SNOW TO CENTRAL INDIANA MIDWEEK ALONG WITH COOLER TEMPERATURES. HOWEVER...MORE WARM TEMPERATURES AND DRY CONDITIONS SHOULD RETURN NEXT WEEKEND. && .NEAR TERM /TODAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 MAIN FOCUS TODAY WILL BE ON MORNING STRATOCU AND OR PATCHY FOG WITH THE CONCENTRATION THIS AFTERNOON ON TEMPERATURES. THE RUC13 925 MILLIBAR RH PROGS SEEMED TO HAVE A GOOD HANDLE ON THE STRATOCU DECK...CURRENTLY ACROSS EASTERN ILLINOIS. IT SUGGESTS THE EASTERN EDGE OF THIS DECK WILL BE ACROSS OUR SOUTHWESTERN COUNTIES AT 12Z THIS MORNING...SO LEFT SOME SKY COVER IN THERE THROUGH MID MORNING WITH LITTLE ELSEWHERE UNTIL LATE IN THE AFTERNOON WHEN SOME HIGH CLOUDS WILL MOVE IN FROM THE UPPER MIDWEST IN THE FAST NORTHWEST FLOW ALOFT. WITH TEMPERATURES NEARING THEIR DEW POINTS AND LIGHT WINDS...WILL GO WITH PATCHY FOG THROUGH 14Z. THERE IS SOME CONCERN THE STRATOCU AND OR FOG WILL HANG AROUND LONGER THAN THAT WITH HIGH RESOLUTION SHORT TERM MODEL SOUNDINGS SHOWING A STRONG INVERSION AROUND 925 MILLIBARS. AFTER THE LOW CLOUDS AND OR FOG ARE GONE...THERE SHOULD BE SUNNY SKIES WITH MODEL TIME SECTIONS SHOWING A DRY COLUMN AND A HIGH PRESSURE RIDGE FROM THE SOUTHERN PLAINS THROUGH THE OHIO VALLEY. WITH SOUTHWEST FLOW...PREFER THE WARMER 00Z GFS MOS WHICH IS CLOSE TO 00Z CONSALL. AFTERNOON HIGHS SHOULD BE IN THE 40S WHICH IS JUST BELOW NORMAL. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 TEMPERATURES AS WELL AS CLOUD COVER WILL BE THE CHALLENGE FOR THE SHORT TERM. MODELS ARE IN GOOD AGREEMENT REGARDING THE SHORT TERM SYNOPTIC PATTERN...SO CONFIDENCE IS GOOD REGARDING A BLEND. MODELS KEEP SOUTHWEST FLOW ACROSS CENTRAL INDIANA THROUGH TUESDAY AND BUFKIT SUGGESTS MONDAY WILL BE BREEZY AS A LOW PRESSURE SYSTEM MOVES EAST ACROSS ONTARIO AND THE SURFACE HIGH SETTLES ACROSS THE GULF CREATING A STRENGTHENING SURFACE LOW PRESSURE GRADIENT ACROSS THE GREAT LAKES AND OHIO VALLEY. A FRONT SHOULD THEN SLIDE SOUTHEAST ACROSS THE AREA ON TUESDAY AS A STRONG LOW PRESSURE SYSTEM MOVES INTO THE CENTRAL PLAINS AHEAD OF AN UPPER WAVE. WITH DRY AIR IN THE LOWER LEVELS...PRECIPITATION SHOULD HOLD OFF UNTIL TUESDAY NIGHT...WHEN OVERRUNNING REALLY RAMPS UP AND ATMOSPHERE MOISTENS FROM THE TOP DOWN AS THE PLAINS LOW PRESSURE SYSTEM MOVES ACROSS KENTUCKY. MODEL TIME SECTIONS AND UPSTREAM SATELLITE AND OBS ARE IMPLYING QUITE A BIT OF CIRRUS AND POSSIBLY AC WILL BE OVER CENTRAL INDIANA THROUGH THE BULK OF THE SHORT TERM. THUS...PREFER THE 00Z ECMWF WHICH HAS MORE SKY COVER THAN ANY BLEND. DESPITE THIS...PREFER TO SIDE WITH THE WARMER 00Z GFS ONCE AGAIN AS IT HAS BEEN DOING BETTER WITH THE RECENT WARMER DAYS. ESPECIALLY PREFER THE WARMER GFS ON MONDAY WITH THE BREEZY SOUTHWEST WINDS THAT WE SHOULD SEE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 408 AM EDT SUN MAR 9 2014 LOW PRESSURE MOVING FROM THE CENTRAL PLAINS THROUGH THE OHIO VALLEY WILL BRING RAIN AND THEN SNOW TO CENTRAL INDIANA TUESDAY NIGHT THROUGH WEDNESDAY. WHILE MODEL SOLUTIONS ON THE SURFACE LOW TRACK ARE COMING INTO BETTER AGREEMENT...THERE IS STILL A DECENT DISCREPANCY IN HOW QUICKLY THE COLD AIR FILTERS IN...WITH THE GFS FASTER THAN THE ECMWF IN BRINGING IT IN. FOR PRECIPITATION TYPE GENERALLY TRIED TO GO WITH ONLY ONE PRECIP TYPE IF BOTH GFS AND ECMWF WERE IN AGREEMENT AND A MIX IF THEY DIDN/T. TEMPERATURE PROFILES LOOK LIKE COLD AIR ALOFT WILL ARRIVE WILL ARRIVE BEFORE OR CONCURRENT WITH COLD AIR AT THE SURFACE SO NO EXPECTATION OF ANYTHING BESIDES RAIN OR SNOW. THUS STARTED OUT ALL RAIN EARLY TUESDAY NIGHT CHANGING OVER TO SNOW IN THE FAR NORTH AFTER 6Z...WITH RAIN OR SNOW COMING SOUTH TO AROUND I-70...AND RAIN SOUTH OF THERE. BY WEDNESDAY MORNING ALL SNOW GENERALLY NORTH OF I-70 WITH A MIX SOUTH AND ALL RAIN IN THE FAR SOUTH. BY WEDNESDAY AFTERNOON GFS AND ECMWF BOTH INDICATE ALL SNOW ACROSS THE ENTIRE AREA. THE SYSTEM SHOULD MOVE OUT ON WEDNESDAY NIGHT AND HIGH PRESSURE WILL BUILD IN ITS WAKE. AS FAR AS SNOWFALL AMOUNTS ARE CONCERNED...RIGHT NOW LOOKS LIKE AN INCH OR TWO POSSIBLE ALONG AND NORTH OF I-70 WITH HALF AN INCH TO AN INCH SOUTH. WITH THE GROUND RELATIVELY WARM BEFORE THIS STARTS FROM HIGHS IN THE 50S AND 60S ON MONDAY AND TUESDAY THINK IT WILL BE DIFFICULT TO ACCUMULATE ESPECIALLY EARLY ON. THE REST OF THE LONG TERM SHOULD BE RELATIVELY QUIET WITH HIGH PRESSURE MOVING THROUGH AND REBOUNDING TEMPERATURES. && .AVIATION /DISCUSSION FOR THE 091800Z TAFS/... ISSUED AT 1242 PM EDT SUN MAR 9 2014 VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD. HIGH PRESSURE STRETCHING FROM THE SOUTHERN PLAINS...ACROSS INDIANA TO WESTERN NEW YORK WILL DRIFT SLOWLY SOUTHEAST DURING THIS TAF PERIOD. WARM AIR ADVECTION ALOFT WILL CONTRIBUTE TO MID AND HIGH CLOUD CEILINGS. A GOOD LOWER LEVEL PRESSURE GRADIENT WILL PROVIDE GOOD MIXING THROUGH THE NIGHT...PREVENTING FOG AND VISIBILITY RESTRICTIONS. FORECAST SOUNDINGS AND TIME HEIGHT SECTIONS CONFIRM...SHOWING DRY LOWER LEVELS WITH UNREACHABLE CONVECTIVE TEMPERATURES. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MK NEAR TERM...MK SHORT TERM...MK LONG TERM....CP AVIATION...JP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1052 AM EDT SUN MAR 9 2014 .UPDATE... AVIATION SECTIONS UPDATED. && .SYNOPSIS... ISSUED AT 315 AM EST SUN MAR 9 2014 ANOTHER WARMUP IS IN STORE EARLY NEXT WEEK UNDER THE INFLUENCE OF SOUTHWEST FLOW WITH AFTERNOON HIGHS IN THE 50S AND 60S MONDAY AND TUESDAY ON TAP. THEN...A PLAINS LOW PRESSURE SYSTEM WILL BRING RAIN AND THEN SNOW TO CENTRAL INDIANA MIDWEEK ALONG WITH COOLER TEMPERATURES. HOWEVER...MORE WARM TEMPERATURES AND DRY CONDITIONS SHOULD RETURN NEXT WEEKEND. && .NEAR TERM /TODAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 MAIN FOCUS TODAY WILL BE ON MORNING STRATOCU AND OR PATCHY FOG WITH THE CONCENTRATION THIS AFTERNOON ON TEMPERATURES. THE RUC13 925 MILLIBAR RH PROGS SEEMED TO HAVE A GOOD HANDLE ON THE STRATOCU DECK...CURRENTLY ACROSS EASTERN ILLINOIS. IT SUGGESTS THE EASTERN EDGE OF THIS DECK WILL BE ACROSS OUR SOUTHWESTERN COUNTIES AT 12Z THIS MORNING...SO LEFT SOME SKY COVER IN THERE THROUGH MID MORNING WITH LITTLE ELSEWHERE UNTIL LATE IN THE AFTERNOON WHEN SOME HIGH CLOUDS WILL MOVE IN FROM THE UPPER MIDWEST IN THE FAST NORTHWEST FLOW ALOFT. WITH TEMPERATURES NEARING THEIR DEW POINTS AND LIGHT WINDS...WILL GO WITH PATCHY FOG THROUGH 14Z. THERE IS SOME CONCERN THE STRATOCU AND OR FOG WILL HANG AROUND LONGER THAN THAT WITH HIGH RESOLUTION SHORT TERM MODEL SOUNDINGS SHOWING A STRONG INVERSION AROUND 925 MILLIBARS. AFTER THE LOW CLOUDS AND OR FOG ARE GONE...THERE SHOULD BE SUNNY SKIES WITH MODEL TIME SECTIONS SHOWING A DRY COLUMN AND A HIGH PRESSURE RIDGE FROM THE SOUTHERN PLAINS THROUGH THE OHIO VALLEY. WITH SOUTHWEST FLOW...PREFER THE WARMER 00Z GFS MOS WHICH IS CLOSE TO 00Z CONSALL. AFTERNOON HIGHS SHOULD BE IN THE 40S WHICH IS JUST BELOW NORMAL. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 TEMPERATURES AS WELL AS CLOUD COVER WILL BE THE CHALLENGE FOR THE SHORT TERM. MODELS ARE IN GOOD AGREEMENT REGARDING THE SHORT TERM SYNOPTIC PATTERN...SO CONFIDENCE IS GOOD REGARDING A BLEND. MODELS KEEP SOUTHWEST FLOW ACROSS CENTRAL INDIANA THROUGH TUESDAY AND BUFKIT SUGGESTS MONDAY WILL BE BREEZY AS A LOW PRESSURE SYSTEM MOVES EAST ACROSS ONTARIO AND THE SURFACE HIGH SETTLES ACROSS THE GULF CREATING A STRENGTHENING SURFACE LOW PRESSURE GRADIENT ACROSS THE GREAT LAKES AND OHIO VALLEY. A FRONT SHOULD THEN SLIDE SOUTHEAST ACROSS THE AREA ON TUESDAY AS A STRONG LOW PRESSURE SYSTEM MOVES INTO THE CENTRAL PLAINS AHEAD OF AN UPPER WAVE. WITH DRY AIR IN THE LOWER LEVELS...PRECIPITATION SHOULD HOLD OFF UNTIL TUESDAY NIGHT...WHEN OVERRUNNING REALLY RAMPS UP AND ATMOSPHERE MOISTENS FROM THE TOP DOWN AS THE PLAINS LOW PRESSURE SYSTEM MOVES ACROSS KENTUCKY. MODEL TIME SECTIONS AND UPSTREAM SATELLITE AND OBS ARE IMPLYING QUITE A BIT OF CIRRUS AND POSSIBLY AC WILL BE OVER CENTRAL INDIANA THROUGH THE BULK OF THE SHORT TERM. THUS...PREFER THE 00Z ECMWF WHICH HAS MORE SKY COVER THAN ANY BLEND. DESPITE THIS...PREFER TO SIDE WITH THE WARMER 00Z GFS ONCE AGAIN AS IT HAS BEEN DOING BETTER WITH THE RECENT WARMER DAYS. ESPECIALLY PREFER THE WARMER GFS ON MONDAY WITH THE BREEZY SOUTHWEST WINDS THAT WE SHOULD SEE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 408 AM EDT SUN MAR 9 2014 LOW PRESSURE MOVING FROM THE CENTRAL PLAINS THROUGH THE OHIO VALLEY WILL BRING RAIN AND THEN SNOW TO CENTRAL INDIANA TUESDAY NIGHT THROUGH WEDNESDAY. WHILE MODEL SOLUTIONS ON THE SURFACE LOW TRACK ARE COMING INTO BETTER AGREEMENT...THERE IS STILL A DECENT DISCREPANCY IN HOW QUICKLY THE COLD AIR FILTERS IN...WITH THE GFS FASTER THAN THE ECMWF IN BRINGING IT IN. FOR PRECIPITATION TYPE GENERALLY TRIED TO GO WITH ONLY ONE PRECIP TYPE IF BOTH GFS AND ECMWF WERE IN AGREEMENT AND A MIX IF THEY DIDN/T. TEMPERATURE PROFILES LOOK LIKE COLD AIR ALOFT WILL ARRIVE WILL ARRIVE BEFORE OR CONCURRENT WITH COLD AIR AT THE SURFACE SO NO EXPECTATION OF ANYTHING BESIDES RAIN OR SNOW. THUS STARTED OUT ALL RAIN EARLY TUESDAY NIGHT CHANGING OVER TO SNOW IN THE FAR NORTH AFTER 6Z...WITH RAIN OR SNOW COMING SOUTH TO AROUND I-70...AND RAIN SOUTH OF THERE. BY WEDNESDAY MORNING ALL SNOW GENERALLY NORTH OF I-70 WITH A MIX SOUTH AND ALL RAIN IN THE FAR SOUTH. BY WEDNESDAY AFTERNOON GFS AND ECMWF BOTH INDICATE ALL SNOW ACROSS THE ENTIRE AREA. THE SYSTEM SHOULD MOVE OUT ON WEDNESDAY NIGHT AND HIGH PRESSURE WILL BUILD IN ITS WAKE. AS FAR AS SNOWFALL AMOUNTS ARE CONCERNED...RIGHT NOW LOOKS LIKE AN INCH OR TWO POSSIBLE ALONG AND NORTH OF I-70 WITH HALF AN INCH TO AN INCH SOUTH. WITH THE GROUND RELATIVELY WARM BEFORE THIS STARTS FROM HIGHS IN THE 50S AND 60S ON MONDAY AND TUESDAY THINK IT WILL BE DIFFICULT TO ACCUMULATE ESPECIALLY EARLY ON. THE REST OF THE LONG TERM SHOULD BE RELATIVELY QUIET WITH HIGH PRESSURE MOVING THROUGH AND REBOUNDING TEMPERATURES. && .AVIATION /DISCUSSION FOR THE 091500Z IND TAF UPDATE/... ONGOING TAFS IN GOOD SHAPE AS VFR CONDITIONS ARE EXPECTED TO CONTINUE WITH HIGH PRESSURE IN PLACE ACROSS CENTRAL INDIANA. PREVIOUS DISCUSSION BELOW /DISCUSSION FOR 091200Z TAF ISSUANCE... ISSUED AT 643 AM EDT SUN MAR 9 2014 MVFR FOG AT KHUF AND KLAF SHOULD BURN OFF BY ABOUT 14Z. MAY SEE SOME OF THIS AT KBMG THROUGH THEN AS WELL. AT KIND THINKING ANY FOG IS LESS LIKELY WITH WINDS NOT DROPPING TO CALM AND DEW POINT DEPRESSION REMAINING A FEW DEGREES SO WILL NOT INCLUDE WITH NEW ISSUANCE. HIGH PRESSURE WILL CONTINUE TO SLIDE SOUTH THROUGH THE DAY AND WINDS SHOULD SHIFT TO SOUTHWESTERLY. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MK NEAR TERM...MK SHORT TERM...MK LONG TERM....CP AVIATION...CP/JP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
648 AM EDT SUN MAR 9 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 315 AM EST SUN MAR 9 2014 ANOTHER WARMUP IS IN STORE EARLY NEXT WEEK UNDER THE INFLUENCE OF SOUTHWEST FLOW WITH AFTERNOON HIGHS IN THE 50S AND 60S MONDAY AND TUESDAY ON TAP. THEN...A PLAINS LOW PRESSURE SYSTEM WILL BRING RAIN AND THEN SNOW TO CENTRAL INDIANA MIDWEEK ALONG WITH COOLER TEMPERATURES. HOWEVER...MORE WARM TEMPERATURES AND DRY CONDITIONS SHOULD RETURN NEXT WEEKEND. && .NEAR TERM /TODAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 MAIN FOCUS TODAY WILL BE ON MORNING STRATOCU AND OR PATCHY FOG WITH THE CONCENTRATION THIS AFTERNOON ON TEMPERATURES. THE RUC13 925 MILLIBAR RH PROGS SEEMED TO HAVE A GOOD HANDLE ON THE STRATOCU DECK...CURRENTLY ACROSS EASTERN ILLINOIS. IT SUGGESTS THE EASTERN EDGE OF THIS DECK WILL BE ACROSS OUR SOUTHWESTERN COUNTIES AT 12Z THIS MORNING...SO LEFT SOME SKY COVER IN THERE THROUGH MID MORNING WITH LITTLE ELSEWHERE UNTIL LATE IN THE AFTERNOON WHEN SOME HIGH CLOUDS WILL MOVE IN FROM THE UPPER MIDWEST IN THE FAST NORTHWEST FLOW ALOFT. WITH TEMPERATURES NEARING THEIR DEW POINTS AND LIGHT WINDS...WILL GO WITH PATCHY FOG THROUGH 14Z. THERE IS SOME CONCERN THE STRATOCU AND OR FOG WILL HANG AROUND LONGER THAN THAT WITH HIGH RESOLUTION SHORT TERM MODEL SOUNDINGS SHOWING A STRONG INVERSION AROUND 925 MILLIBARS. AFTER THE LOW CLOUDS AND OR FOG ARE GONE...THERE SHOULD BE SUNNY SKIES WITH MODEL TIME SECTIONS SHOWING A DRY COLUMN AND A HIGH PRESSURE RIDGE FROM THE SOUTHERN PLAINS THROUGH THE OHIO VALLEY. WITH SOUTHWEST FLOW...PREFER THE WARMER 00Z GFS MOS WHICH IS CLOSE TO 00Z CONSALL. AFTERNOON HIGHS SHOULD BE IN THE 40S WHICH IS JUST BELOW NORMAL. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 TEMPERATURES AS WELL AS CLOUD COVER WILL BE THE CHALLENGE FOR THE SHORT TERM. MODELS ARE IN GOOD AGREEMENT REGARDING THE SHORT TERM SYNOPTIC PATTERN...SO CONFIDENCE IS GOOD REGARDING A BLEND. MODELS KEEP SOUTHWEST FLOW ACROSS CENTRAL INDIANA THROUGH TUESDAY AND BUFKIT SUGGESTS MONDAY WILL BE BREEZY AS A LOW PRESSURE SYSTEM MOVES EAST ACROSS ONTARIO AND THE SURFACE HIGH SETTLES ACROSS THE GULF CREATING A STRENGTHENING SURFACE LOW PRESSURE GRADIENT ACROSS THE GREAT LAKES AND OHIO VALLEY. A FRONT SHOULD THEN SLIDE SOUTHEAST ACROSS THE AREA ON TUESDAY AS A STRONG LOW PRESSURE SYSTEM MOVES INTO THE CENTRAL PLAINS AHEAD OF AN UPPER WAVE. WITH DRY AIR IN THE LOWER LEVELS...PRECIPITATION SHOULD HOLD OFF UNTIL TUESDAY NIGHT...WHEN OVERRUNNING REALLY RAMPS UP AND ATMOSPHERE MOISTENS FROM THE TOP DOWN AS THE PLAINS LOW PRESSURE SYSTEM MOVES ACROSS KENTUCKY. MODEL TIME SECTIONS AND UPSTREAM SATELLITE AND OBS ARE IMPLYING QUITE A BIT OF CIRRUS AND POSSIBLY AC WILL BE OVER CENTRAL INDIANA THROUGH THE BULK OF THE SHORT TERM. THUS...PREFER THE 00Z ECMWF WHICH HAS MORE SKY COVER THAN ANY BLEND. DESPITE THIS...PREFER TO SIDE WITH THE WARMER 00Z GFS ONCE AGAIN AS IT HAS BEEN DOING BETTER WITH THE RECENT WARMER DAYS. ESPECIALLY PREFER THE WARMER GFS ON MONDAY WITH THE BREEZY SOUTHWEST WINDS THAT WE SHOULD SEE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 408 AM EDT SUN MAR 9 2014 LOW PRESSURE MOVING FROM THE CENTRAL PLAINS THROUGH THE OHIO VALLEY WILL BRING RAIN AND THEN SNOW TO CENTRAL INDIANA TUESDAY NIGHT THROUGH WEDNESDAY. WHILE MODEL SOLUTIONS ON THE SURFACE LOW TRACK ARE COMING INTO BETTER AGREEMENT...THERE IS STILL A DECENT DISCREPANCY IN HOW QUICKLY THE COLD AIR FILTERS IN...WITH THE GFS FASTER THAN THE ECMWF IN BRINGING IT IN. FOR PRECIPITATION TYPE GENERALLY TRIED TO GO WITH ONLY ONE PRECIP TYPE IF BOTH GFS AND ECMWF WERE IN AGREEMENT AND A MIX IF THEY DIDN/T. TEMPERATURE PROFILES LOOK LIKE COLD AIR ALOFT WILL ARRIVE WILL ARRIVE BEFORE OR CONCURRENT WITH COLD AIR AT THE SURFACE SO NO EXPECTATION OF ANYTHING BESIDES RAIN OR SNOW. THUS STARTED OUT ALL RAIN EARLY TUESDAY NIGHT CHANGING OVER TO SNOW IN THE FAR NORTH AFTER 6Z...WITH RAIN OR SNOW COMING SOUTH TO AROUND I-70...AND RAIN SOUTH OF THERE. BY WEDNESDAY MORNING ALL SNOW GENERALLY NORTH OF I-70 WITH A MIX SOUTH AND ALL RAIN IN THE FAR SOUTH. BY WEDNESDAY AFTERNOON GFS AND ECMWF BOTH INDICATE ALL SNOW ACROSS THE ENTIRE AREA. THE SYSTEM SHOULD MOVE OUT ON WEDNESDAY NIGHT AND HIGH PRESSURE WILL BUILD IN ITS WAKE. AS FAR AS SNOWFALL AMOUNTS ARE CONCERNED...RIGHT NOW LOOKS LIKE AN INCH OR TWO POSSIBLE ALONG AND NORTH OF I-70 WITH HALF AN INCH TO AN INCH SOUTH. WITH THE GROUND RELATIVELY WARM BEFORE THIS STARTS FROM HIGHS IN THE 50S AND 60S ON MONDAY AND TUESDAY THINK IT WILL BE DIFFICULT TO ACCUMULATE ESPECIALLY EARLY ON. THE REST OF THE LONG TERM SHOULD BE RELATIVELY QUIET WITH HIGH PRESSURE MOVING THROUGH AND REBOUNDING TEMPERATURES. && .AVIATION /DISCUSSION FOR 091200Z TAF ISSUANCE... ISSUED AT 643 AM EDT SUN MAR 9 2014 MVFR FOG AT KHUF AND KLAF SHOULD BURN OFF BY ABOUT 14Z. MAY SEE SOME OF THIS AT KBMG THROUGH THEN AS WELL. AT KIND THINKING ANY FOG IS LESS LIKELY WITH WINDS NOT DROPPING TO CALM AND DEW POINT DEPRESSION REMAINING A FEW DEGREES SO WILL NOT INCLUDE WITH NEW ISSUANCE. HIGH PRESSURE WILL CONTINUE TO SLIDE SOUTH THROUGH THE DAY AND WINDS SHOULD SHIFT TO SOUTHWESTERLY. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MK NEAR TERM...MK SHORT TERM...MK LONG TERM....CP AVIATION...CP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
413 AM EDT SUN MAR 9 2014 .UPDATE... THE LONG TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 315 AM EST SUN MAR 9 2014 ANOTHER WARMUP IS IN STORE EARLY NEXT WEEK UNDER THE INFLUENCE OF SOUTHWEST FLOW WITH AFTERNOON HIGHS IN THE 50S AND 60S MONDAY AND TUESDAY ON TAP. THEN...A PLAINS LOW PRESSURE SYSTEM WILL BRING RAIN AND THEN SNOW TO CENTRAL INDIANA MIDWEEK ALONG WITH COOLER TEMPERATURES. HOWEVER...MORE WARM TEMPERATURES AND DRY CONDITIONS SHOULD RETURN NEXT WEEKEND. && .NEAR TERM /TODAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 MAIN FOCUS TODAY WILL BE ON MORNING STRATOCU AND OR PATCHY FOG WITH THE CONCENTRATION THIS AFTERNOON ON TEMPERATURES. THE RUC13 925 MILLIBAR RH PROGS SEEMED TO HAVE A GOOD HANDLE ON THE STRATOCU DECK...CURRENTLY ACROSS EASTERN ILLINOIS. IT SUGGESTS THE EASTERN EDGE OF THIS DECK WILL BE ACROSS OUR SOUTHWESTERN COUNTIES AT 12Z THIS MORNING...SO LEFT SOME SKY COVER IN THERE THROUGH MID MORNING WITH LITTLE ELSEWHERE UNTIL LATE IN THE AFTERNOON WHEN SOME HIGH CLOUDS WILL MOVE IN FROM THE UPPER MIDWEST IN THE FAST NORTHWEST FLOW ALOFT. WITH TEMPERATURES NEARING THEIR DEW POINTS AND LIGHT WINDS...WILL GO WITH PATCHY FOG THROUGH 14Z. THERE IS SOME CONCERN THE STRATOCU AND OR FOG WILL HANG AROUND LONGER THAN THAT WITH HIGH RESOLUTION SHORT TERM MODEL SOUNDINGS SHOWING A STRONG INVERSION AROUND 925 MILLIBARS. AFTER THE LOW CLOUDS AND OR FOG ARE GONE...THERE SHOULD BE SUNNY SKIES WITH MODEL TIME SECTIONS SHOWING A DRY COLUMN AND A HIGH PRESSURE RIDGE FROM THE SOUTHERN PLAINS THROUGH THE OHIO VALLEY. WITH SOUTHWEST FLOW...PREFER THE WARMER 00Z GFS MOS WHICH IS CLOSE TO 00Z CONSALL. AFTERNOON HIGHS SHOULD BE IN THE 40S WHICH IS JUST BELOW NORMAL. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 TEMPERATURES AS WELL AS CLOUD COVER WILL BE THE CHALLENGE FOR THE SHORT TERM. MODELS ARE IN GOOD AGREEMENT REGARDING THE SHORT TERM SYNOPTIC PATTERN...SO CONFIDENCE IS GOOD REGARDING A BLEND. MODELS KEEP SOUTHWEST FLOW ACROSS CENTRAL INDIANA THROUGH TUESDAY AND BUFKIT SUGGESTS MONDAY WILL BE BREEZY AS A LOW PRESSURE SYSTEM MOVES EAST ACROSS ONTARIO AND THE SURFACE HIGH SETTLES ACROSS THE GULF CREATING A STRENGTHENING SURFACE LOW PRESSURE GRADIENT ACROSS THE GREAT LAKES AND OHIO VALLEY. A FRONT SHOULD THEN SLIDE SOUTHEAST ACROSS THE AREA ON TUESDAY AS A STRONG LOW PRESSURE SYSTEM MOVES INTO THE CENTRAL PLAINS AHEAD OF AN UPPER WAVE. WITH DRY AIR IN THE LOWER LEVELS...PRECIPITATION SHOULD HOLD OFF UNTIL TUESDAY NIGHT...WHEN OVERRUNNING REALLY RAMPS UP AND ATMOSPHERE MOISTENS FROM THE TOP DOWN AS THE PLAINS LOW PRESSURE SYSTEM MOVES ACROSS KENTUCKY. MODEL TIME SECTIONS AND UPSTREAM SATELLITE AND OBS ARE IMPLYING QUITE A BIT OF CIRRUS AND POSSIBLY AC WILL BE OVER CENTRAL INDIANA THROUGH THE BULK OF THE SHORT TERM. THUS...PREFER THE 00Z ECMWF WHICH HAS MORE SKY COVER THAN ANY BLEND. DESPITE THIS...PREFER TO SIDE WITH THE WARMER 00Z GFS ONCE AGAIN AS IT HAS BEEN DOING BETTER WITH THE RECENT WARMER DAYS. ESPECIALLY PREFER THE WARMER GFS ON MONDAY WITH THE BREEZY SOUTHWEST WINDS THAT WE SHOULD SEE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 408 AM EDT SUN MAR 9 2014 LOW PRESSURE MOVING FROM THE CENTRAL PLAINS THROUGH THE OHIO VALLEY WILL BRING RAIN AND THEN SNOW TO CENTRAL INDIANA TUESDAY NIGHT THROUGH WEDNESDAY. WHILE MODEL SOLUTIONS ON THE SURFACE LOW TRACK ARE COMING INTO BETTER AGREEMENT...THERE IS STILL A DECENT DISCREPANCY IN HOW QUICKLY THE COLD AIR FILTERS IN...WITH THE GFS FASTER THAN THE ECMWF IN BRINGING IT IN. FOR PRECIPITATION TYPE GENERALLY TRIED TO GO WITH ONLY ONE PRECIP TYPE IF BOTH GFS AND ECMWF WERE IN AGREEMENT AND A MIX IF THEY DIDN/T. TEMPERATURE PROFILES LOOK LIKE COLD AIR ALOFT WILL ARRIVE WILL ARRIVE BEFORE OR CONCURRENT WITH COLD AIR AT THE SURFACE SO NO EXPECTATION OF ANYTHING BESIDES RAIN OR SNOW. THUS STARTED OUT ALL RAIN EARLY TUESDAY NIGHT CHANGING OVER TO SNOW IN THE FAR NORTH AFTER 6Z...WITH RAIN OR SNOW COMING SOUTH TO AROUND I-70...AND RAIN SOUTH OF THERE. BY WEDNESDAY MORNING ALL SNOW GENERALLY NORTH OF I-70 WITH A MIX SOUTH AND ALL RAIN IN THE FAR SOUTH. BY WEDNESDAY AFTERNOON GFS AND ECMWF BOTH INDICATE ALL SNOW ACROSS THE ENTIRE AREA. THE SYSTEM SHOULD MOVE OUT ON WEDNESDAY NIGHT AND HIGH PRESSURE WILL BUILD IN ITS WAKE. AS FAR AS SNOWFALL AMOUNTS ARE CONCERNED...RIGHT NOW LOOKS LIKE AN INCH OR TWO POSSIBLE ALONG AND NORTH OF I-70 WITH HALF AN INCH TO AN INCH SOUTH. WITH THE GROUND RELATIVELY WARM BEFORE THIS STARTS FROM HIGHS IN THE 50S AND 60S ON MONDAY AND TUESDAY THINK IT WILL BE DIFFICULT TO ACCUMULATE ESPECIALLY EARLY ON. THE REST OF THE LONG TERM SHOULD BE RELATIVELY QUIET WITH HIGH PRESSURE MOVING THROUGH AND REBOUNDING TEMPERATURES. && .AVIATION /DISCUSSION FOR THE 090900Z TAFS/... ISSUED AT 410 AM EDT SAT MAR 8 2014 WITH THE UPDATE WILL BE ADDING AT LEAST SOME MVFR FOG CURRENTLY TO KLAF AND TO KHUF WITHIN AN HOUR TO ADDRESS CURRENT CONDITIONS. WITH THOSE SITES TRENDING THAT WAY WILL ALSO ADD SOME TO KBMG AND KIND BUT A BIT A LATER. PREVIOUS DISCUSSION FOLLOWS... MVFR CEILINGS HAVE PUSHED OFF TO THE SOUTHEAST OF THE TAF SITES...WHILE ANOTHER AREA OF CEILINGS AROUND 030 IS DROPPING SOUTHEAST ACROSS ILLINOIS. TRAJECTORY OF CLOUD DECK AND SHORT TERM MODEL DATA SUGGEST THESE CEILINGS MAY GRAZE THE KHUF TERMINAL AT TIMES THROUGH ABOUT 091000Z. SOME CONCERN ABOUT FOG DEVELOPING OVERNIGHT AS SKIES CLEAR AND WINDS DIMINISH. LOWER SURFACE DEWPOINTS HAVE BEEN ADVECTING INTO THE AREA...SO WILL KEEP VISIBILITY RESTRICTIONS OUT OF THE FORECAST AT THIS TIME. SURFACE WINDS SHOULD CONTINUE TO DIMINISH AS HIGH PRESSURE BUILDS IN...WITH WINDS EXPECTED TO BACK AROUND TO 220-240 DEGREES AT 8-10 KTS BY EARLY AFTERNOON SUNDAY. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MK NEAR TERM...MK SHORT TERM...MK LONG TERM....CP AVIATION...JAS/CP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
315 AM EST SUN MAR 9 2014 .UPDATE... THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 315 AM EST SUN MAR 9 2014 ANOTHER WARMUP IS IN STORE EARLY NEXT WEEK UNDER THE INFLUENCE OF SOUTHWEST FLOW WITH AFTERNOON HIGHS IN THE 50S AND 60S MONDAY AND TUESDAY ON TAP. THEN...A PLAINS LOW PRESSURE SYSTEM WILL BRING RAIN AND THEN SNOW TO CENTRAL INDIANA MIDWEEK ALONG WITH COOLER TEMPERATURES. HOWEVER...MORE WARM TEMPERATURES AND DRY CONDITIONS SHOULD RETURN NEXT WEEKEND. && .NEAR TERM /TODAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 MAIN FOCUS TODAY WILL BE ON MORNING STRATOCU AND OR PATCHY FOG WITH THE CONCENTRATION THIS AFTERNOON ON TEMPERATURES. THE RUC13 925 MILLIBAR RH PROGS SEEMED TO HAVE A GOOD HANDLE ON THE STRATOCU DECK...CURRENTLY ACROSS EASTERN ILLINOIS. IT SUGGESTS THE EASTERN EDGE OF THIS DECK WILL BE ACROSS OUR SOUTHWESTERN COUNTIES AT 12Z THIS MORNING...SO LEFT SOME SKY COVER IN THERE THROUGH MID MORNING WITH LITTLE ELSEWHERE UNTIL LATE IN THE AFTERNOON WHEN SOME HIGH CLOUDS WILL MOVE IN FROM THE UPPER MIDWEST IN THE FAST NORTHWEST FLOW ALOFT. WITH TEMPERATURES NEARING THEIR DEW POINTS AND LIGHT WINDS...WILL GO WITH PATCHY FOG THROUGH 14Z. THERE IS SOME CONCERN THE STRATOCU AND OR FOG WILL HANG AROUND LONGER THAN THAT WITH HIGH RESOLUTION SHORT TERM MODEL SOUNDINGS SHOWING A STRONG INVERSION AROUND 925 MILLIBARS. AFTER THE LOW CLOUDS AND OR FOG ARE GONE...THERE SHOULD BE SUNNY SKIES WITH MODEL TIME SECTIONS SHOWING A DRY COLUMN AND A HIGH PRESSURE RIDGE FROM THE SOUTHERN PLAINS THROUGH THE OHIO VALLEY. WITH SOUTHWEST FLOW...PREFER THE WARMER 00Z GFS MOS WHICH IS CLOSE TO 00Z CONSALL. AFTERNOON HIGHS SHOULD BE IN THE 40S WHICH IS JUST BELOW NORMAL. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 315 AM EST SUN MAR 9 2014 TEMPERATURES AS WELL AS CLOUD COVER WILL BE THE CHALLENGE FOR THE SHORT TERM. MODELS ARE IN GOOD AGREEMENT REGARDING THE SHORT TERM SYNOPTIC PATTERN...SO CONFIDENCE IS GOOD REGARDING A BLEND. MODELS KEEP SOUTHWEST FLOW ACROSS CENTRAL INDIANA THROUGH TUESDAY AND BUFKIT SUGGESTS MONDAY WILL BE BREEZY AS A LOW PRESSURE SYSTEM MOVES EAST ACROSS ONTARIO AND THE SURFACE HIGH SETTLES ACROSS THE GULF CREATING A STRENGTHENING SURFACE LOW PRESSURE GRADIENT ACROSS THE GREAT LAKES AND OHIO VALLEY. A FRONT SHOULD THEN SLIDE SOUTHEAST ACROSS THE AREA ON TUESDAY AS A STRONG LOW PRESSURE SYSTEM MOVES INTO THE CENTRAL PLAINS AHEAD OF AN UPPER WAVE. WITH DRY AIR IN THE LOWER LEVELS...PRECIPITATION SHOULD HOLD OFF UNTIL TUESDAY NIGHT...WHEN OVERRUNNING REALLY RAMPS UP AND ATMOSPHERE MOISTENS FROM THE TOP DOWN AS THE PLAINS LOW PRESSURE SYSTEM MOVES ACROSS KENTUCKY. MODEL TIME SECTIONS AND UPSTREAM SATELLITE AND OBS ARE IMPLYING QUITE A BIT OF CIRRUS AND POSSIBLY AC WILL BE OVER CENTRAL INDIANA THROUGH THE BULK OF THE SHORT TERM. THUS...PREFER THE 00Z ECMWF WHICH HAS MORE SKY COVER THAN ANY BLEND. DESPITE THIS...PREFER TO SIDE WITH THE WARMER 00Z GFS ONCE AGAIN AS IT HAS BEEN DOING BETTER WITH THE RECENT WARMER DAYS. ESPECIALLY PREFER THE WARMER GFS ON MONDAY WITH THE BREEZY SOUTHWEST WINDS THAT WE SHOULD SEE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 155 PM EST SAT MAR 8 2014 FOCUS OF LONG TERM REMAINS MID WEEK STORM. MODELS ARE TRENDING FASTER WITH THE SYSTEM...WITH MAINLY RAIN TUESDAY NIGHT AND MAINLY SNOW WEDNESDAY. REMAINDER OF FORECAST PERIOD APPEARS DRY AS HIGH PRESSURE BUILDS BACK INTO THE AREA. FOCUS THEN TRANSITIONS TO TEMPERATURES. ALLBLEND INITIALIZATION WAS REASONABLE BASED ON 850 TEMPS AND FEW CHANGES WERE REQUIRED. WILL INITIALLY SEE A DROP WEDNESDAY AND THURSDAY BEFORE RECOVERING AGAIN BACK INTO THE 50S FRIDAY AND SATURDAY. && .AVIATION /DISCUSSION FOR THE 090600Z TAFS/... ISSUED AT 1132 PM EST SAT MAR 8 2014 MVFR CEILINGS HAVE PUSHED OFF TO THE SOUTHEAST OF THE TAF SITES...WHILE ANOTHER AREA OF CEILINGS AROUND 030 IS DROPPING SOUTHEAST ACROSS ILLINOIS. TRAJECTORY OF CLOUD DECK AND SHORT TERM MODEL DATA SUGGEST THESE CEILINGS MAY GRAZE THE KHUF TERMINAL AT TIMES THROUGH ABOUT 091000Z. SOME CONCERN ABOUT FOG DEVELOPING OVERNIGHT AS SKIES CLEAR AND WINDS DIMINISH. LOWER SURFACE DEWPOINTS HAVE BEEN ADVECTING INTO THE AREA...SO WILL KEEP VISIBILITY RESTRICTIONS OUT OF THE FORECAST AT THIS TIME. SURFACE WINDS SHOULD CONTINUE TO DIMINISH AS HIGH PRESSURE BUILDS IN...WITH WINDS EXPECTED TO BACK AROUND TO 220-240 DEGREES AT 8-10 KTS BY EARLY AFTERNOON SUNDAY. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...MK NEAR TERM...MK SHORT TERM...MK LONG TERM...NIELD AVIATION...JAS VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1239 AM EST SUN MAR 9 2014 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 249 PM EST SAT MAR 8 2014 A ROLLER COASTER OF TEMPERATURES WILL BE SEEN THIS WEEK. AFTER A COOLER DAY SUNDAY...WARM CONDITIONS WILL RETURN FOR MONDAY AND TUESDAY. AN AREA OF LOW PRESSURE WILL BRING SOME PRECIPITATION TUESDAY NIGHT INTO WEDNESDAY...AND WELL BELOW NORMAL TEMPERATURES WILL BE THE RULE THURSDAY. HOWEVER SEASONAL READINGS WILL RETURN FOR EARLY NEXT WEEKEND. && .NEAR TERM /REST OF OVERNIGHT/... ISSUED AT 1239 AM EST SUN MAR 9 2014 ADDED SOME LOW CLOUDS TO SOUTHWESTERN PARTS OF THE FORECAST AREA OVERNIGHT PER SATELLITE TRENDS AND RUC13 SKY COVER. PREVIOUS DISCUSSION FOLLOWS... MAIN UPDATE WILL BE TO DROP ANY MENTION OF PRECIPITATION FOR THE REST OF TONIGHT AS DRIER AIR WILL CONTINUE TO MOVE INTO OUR REGION. SATELLITE SHOWS A THINNING OUT OF CLOUDS OVER NORTHWEST AND WEST CENTRAL SECTIONS AND CLEARING WILL SPREAD INTO ALL AREAS LATER TONIGHT. NOT SURE ABOUT THE PATCHY FOG OVER NORTHWEST SECTIONS...BUT WITH LIGHT WINDS LATE TONIGHT WILL LEAVE IT IN AS IS FOR NOW. CONCERNING LOW TEMPERATURES...DROPPED LOW TEMPERATURES SLIGHTLY OVER NORTHWEST SECTIONS PER RAPID REFRESH MODEL. OTHERWISE...CURRENT FORECAST ON TRACK AND ONLY MINOR TWEAKS MADE TO THE REST OF THE GRIDS. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... ISSUED AT 249 PM EST SAT MAR 8 2014 FOCUS IS ON TEMPERATURES. MODELS ARE CLOSE ENOUGH THAT A BLEND CAN BE USED. ANY LINGERING CLOUDS WILL EXIT SUNDAY MORNING LEAVING A GOOD AMOUNT OF SUNSHINE SUNDAY AFTERNOON. THIS PLUS WARM ADVECTION SHOULD PUSH TEMPERATURES TO THE WARMER MAV MOS NUMBERS. WENT WITH A MODEL BLEND FOR LOWS SUNDAY NIGHT WITH A GRADUAL INCREASE IN CLOUDS FROM THE NORTH AND A SOUTHWEST WIND. A FRONT WILL TRY AND WORK SOUTH TOWARD THE AREA MONDAY BUT SHOULD DO LITTLE MORE THAN BRING SOME CLOUDS. WARM ADVECTION AHEAD OF THE FRONT WILL HELP BOOST TEMPERATURES. WENT WARMER THAN MOS GIVEN HOW MOS HAS PERFORMED RECENTLY IN WARMER REGIMES. FRONT WILL BE IN THE AREA ON TUESDAY BUT WITH A SURFACE LOW WELL TO THE SOUTHWEST FEEL THAT CONDITIONS WILL REMAIN DRY DURING THE DAY. WITH COLDER AIR NOT MAKING MUCH HEADWAY INTO THE AREA /DUE TO THE APPROACHING SURFACE LOW/ CONDITIONS WILL REMAIN WARM. WENT WITH A BLEND OF RAW MODEL TEMPERATURES. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 155 PM EST SAT MAR 8 2014 FOCUS OF LONG TERM REMAINS MID WEEK STORM. MODELS ARE TRENDING FASTER WITH THE SYSTEM...WITH MAINLY RAIN TUESDAY NIGHT AND MAINLY SNOW WEDNESDAY. REMAINDER OF FORECAST PERIOD APPEARS DRY AS HIGH PRESSURE BUILDS BACK INTO THE AREA. FOCUS THEN TRANSITIONS TO TEMPERATURES. ALLBLEND INITIALIZATION WAS REASONABLE BASED ON 850 TEMPS AND FEW CHANGES WERE REQUIRED. WILL INITIALLY SEE A DROP WEDNESDAY AND THURSDAY BEFORE RECOVERING AGAIN BACK INTO THE 50S FRIDAY AND SATURDAY. && .AVIATION /DISCUSSION FOR THE 090600Z TAFS/... ISSUED AT 1132 PM EST SAT MAR 8 2014 MVFR CEILINGS HAVE PUSHED OFF TO THE SOUTHEAST OF THE TAF SITES...WHILE ANOTHER AREA OF CEILINGS AROUND 030 IS DROPPING SOUTHEAST ACROSS ILLINOIS. TRAJECTORY OF CLOUD DECK AND SHORT TERM MODEL DATA SUGGEST THESE CEILINGS MAY GRAZE THE KHUF TERMINAL AT TIMES THROUGH ABOUT 091000Z. SOME CONCERN ABOUT FOG DEVELOPING OVERNIGHT AS SKIES CLEAR AND WINDS DIMINISH. LOWER SURFACE DEWPOINTS HAVE BEEN ADVECTING INTO THE AREA...SO WILL KEEP VISIBILITY RESTRICTIONS OUT OF THE FORECAST AT THIS TIME. SURFACE WINDS SHOULD CONTINUE TO DIMINISH AS HIGH PRESSURE BUILDS IN...WITH WINDS EXPECTED TO BACK AROUND TO 220-240 DEGREES AT 8-10 KTS BY EARLY AFTERNOON SUNDAY. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...50 NEAR TERM...JH/MK SHORT TERM...50 LONG TERM...NIELD AVIATION...JAS VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1052 PM CDT MON MAR 10 2014 .UPDATE... SCATTERED MID LVL CLOUDS CONTINUE TO STREAM OVER THE REGION THIS EVENING AHEAD OF AN UPPER LVL LOW THAT IS CROSSING S TX. LATEST REGIONAL RADAR MOSAIC SHOWS SCT SHOWERS AND TSTMS DEVELOPING OFF THE LOWER TX COAST...EAST OF BROWNSVILLE TO CORPUS CHRISTI. AN INVERTED SFC TROF WAS DEVELOPING OVER THE WRN GULF OF MEXICO WITH SELY FLOW PREVAILING OVER THE AREA. AN AREA OF SEA FOG WAS NOTED OFF THE UPPER TX COAST EARLIER THIS AFTN...BUT SEE NO INDICATION THAT THIS AREA HAS EDGED BACK OVER OUR WRN COASTAL ZONES YET BASED ON OBS/SATELLITE DATA. HOWEVER...STILL THINK PATCHY FOG WILL DEVELOP OVERNIGHT OVER THE WRN NEARSHORE WATERS...OUTSIDE OF SHOWER OR TSTM ACTIVITY...WITH PATCHY FOG ALSO DEVELOPING OVER INLAND ZONES. NO INDICATIONS OF DENSE FOG DEVELOPING AT THIS POINT...ALTHOUGH CANNOT RULE IT OUT ENTIRELY AS A FEW SPOTS COULD SEE VISBYS DOWN TO ONE HALF MILE OR LESS BEFORE TUESDAY MORNING. FOG OVER THE COASTAL WATERS IS EXPECTED TO PERSIST INTO TUESDAY MORNING AND COULD LAST UNTIL THE PASSAGE OF THE COLD FRONT TUESDAY NIGHT. OTHERWISE...LOWERED POPS FOR THE REMAINDER OF THE EVENING WITH ACTIVITY NOT EXPECTED TO DEVELOP/INCREASE UNTIL AFTER MIDNIGHT AS THE UPPER LOW MOVES CLOSER TO THE AREA. ALSO MADE SOME SMALL ADJUSTMENTS TO POPS FOR THE OVERNIGHT PERIOD INTO TUESDAY MORNING ALTHOUGH HIGHEST CHANCES STILL REMAIN OVER THE COASTAL ZONES AND ADJACENT COASTAL PARISHES AND COUNTIES. REMAINDER OF FCST LOOKS GOOD AND UPDATED PRODUCTS HAVE BEEN SENT. 24 && .PREV DISCUSSION... /ISSUED 752 PM CDT MON MAR 10 2014/ DISCUSSION... AN INVERTED TROUGH IN THE GULF EASTERLIES EXTENDS FROM MARSH ISLAND TO OFFSHORE LAGUNA MADRE. INCOMING CAMPECHE AIR GENTLY ASCENDS UPON ENCOUNTERING THE TROUGH. A PACIFIC SHORTWAVE WILL TRAVEL EASTWARD ACROSS TEXAS...ENTERING SOUTHEAST TEXAS BY MIDMORNING TUESDAY. ITS ATTENDANT PVA LIFT WILL PHASE IN WITH THE UPSLIDING LIFT ATTENDING THE INVERTED TROUGH. RAIN WILL EMBEDDED SHOWERS ARE EXPECTED...MAINLY ALONG AND SOUTH OF THE I-10 CORRIDOR. JT PREV DISCUSSION... /ISSUED 407 PM CDT MON MAR 10 2014/ DISCUSSION... LATEST WATER VAPOR SATELLITE IMAGERY/UPPER AIR ANALYSIS SHOWED AND UPPER LOW DRIFTING EAST ACROSS NORTHERN MEXICO...WITH AN UPSTREAM SHORTWAVE TROF TRANSLATING THROUGH THE PAC NW. AT THE SFC...BROAD HIGH PRESSURE STRETCHED ACROSS THE NORTHERN GULF COAST. AFTER CONTENDING WITH AREAS OF DENSE FOG THIS MORNING...A RATHER PLEASANT DAY HAS UNFOLDED ACROSS THE REGION...WITH PLENTY OF SUN RESULTING IN TEMPERATURES CLIMBING INTO THE LOWER TO MID 70S. THE AREA OF SURFACE HIGH PRESSURE IS PROGGED TO CONTINUE SHIFTING OFF A LITTLE TO THE EAST INTO TONIGHT...ALLOWING FOR AT LEAST A WEAK RETURN FLOW TO SET UP. WITH SHELF WATER TEMPERATURES STILL IN THE MID/UPPER 50S...AREAS OF SEA FOG ARE EXPECTED TO DEVELOP THIS EVENING AS AIR CHARACTERIZED BY LOWER 60S DEWPOINTS BEGINS TO ADVECT ATOP IT. LATEST HRRR AND RUC FCSTS INDICATE FOG DEVELOPING OVER THE NEARSHORE WATERS WEST OF CAMERON...THEN DEVELOPING FARTHER NORTH/INLAND DURING THE OVERNIGHT HOURS. DREW IN AREAS OF FOG THAT GENERALLY MATCHES THIS EVOLUTION...BUT AM A LITTLE HESITANT TO ISSUE AN ADVISORY AT THIS TIME. WOULD PREFER TO LET THE EVENING CREW SEE HOW THE SITUATION BEGINS TO EVOLVE. THE UPPER LOW TO THE WEST IS EXPECTED TO CONTINUE EASTWARD...WITH SHOWERS AND THUNDERSTORMS EXPECTED TO FORM ALONG AND AHEAD OF AN ASSOCIATED N-S LOW PRESSURE TROF. MOST OF THIS ACTIVITY CONTINUES TO BE PROGGED TO OCCUR OVER THE GULF WATERS AND COASTAL AREAS ROUGHLY ALONG AND SOUTH OF I-10...AND SO THE HIGHEST POPS WERE RETAINED IN THESE AREAS. RAINFALL IS FCST TO END FROM WEST TO EAST DURING THE AFTERNOON HOURS...BUT IT IS POSSIBLE THAT ANY SEA FOG WILL PERSIST AND PERHAPS EVEN SPREAD FARTHER EAST AMID WINDS BECOMING MORE FROM THE SW. ON THE HEELS OF THIS LEAD SYSTEM...A RELATIVELY STRONG COLD FRONT IS STILL ON TRACK TO SWEEP THROUGH THE REGION LATE TUESDAY NIGHT INTO EARLY WED. THIS WILL CERTAINLY BRING AN END TO ANY SEA FOG...AND WITH SIGNIFICANT MOISTURE HAVING BEEN SHUNTED EASTWARD BY THE LEAD SYSTEM...THE PASSAGE IS EXPECTED TO BE A DRY ONE. AMID BRISK NORTH WINDS...MUCH COOLER AND DRIER AIR WILL SPILL INTO THE REGION...WITH TEMPERATURES BY THURSDAY MORNING EXPECTED TO RANGE FROM THE MID 30S OVER INTERIOR EAST TEXAS AND CENTRAL LOUISIANA TO NEAR 40 ALONG THE COAST AS THE POST-FRONTAL HIGH SETTLES SOUTH INTO TEXAS. COOL TEMPERATURES ARE EXPECTED TO CONTINUE THROUGH THURSDAY...WITH HIGHS STRUGGLING TO REACH 60 FOR MUCH OF THE AREA. AS THE HIGH SHIFTS TO THE EAST THURSDAY NIGHT...TEMPERATURES WILL BEGIN TO MODERATE...WITH A WARMING TREND CONTINUING INTO THE START OF THE WEEKEND. THE FORECAST OVER THE WEEKEND AND INTO EARLY NEXT WEEK CONTINUES TO BE ONE OF LOW CONFIDENCE...AND GENERALLY A BLEND OF THE PREVIOUS FORECAST AND LATEST WPC GUIDANCE WAS USED. 13 MARINE... WEAK TO OCCASIONALLY MODERATE EASTERLY FLOW IS EXPECTED AHEAD OF AN UPPER LEVEL LOW THAT WILL BRING SHOWERS AND THUNDERSTORMS TO THE NORTHERN GULF TONIGHT AND TUESDAY. AREAS OF FOG ARE EXPECTED TO DEVELOP OVER THE NEARSHORE WATERS FROM CAMERON TO HIGH ISLAND THIS EVENING...THEN SUBSEQUENTLY SPREAD INTO SABINE AND CALCASIEU LAKES. A STRONG COLD FRONT WILL MOVE THROUGH AREA ON WEDNESDAY. INCREASED OFFSHORE FLOW IS FORECAST FOR WEDNESDAY AND WEDNESDAY NIGHT. WINDS AND SEAS WILL LIKELY BE WITHIN SMALL CRAFT ADVISORY RANGE WEDNESDAY AND WEDNESDAY NIGHT. WINDS WILL DIMINISH ON THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION. 13 && .PRELIMINARY POINT TEMPS/POPS... KLCH 56 71 56 64 / 40 50 10 10 KBPT 56 74 57 66 / 50 40 10 10 KAEX 55 74 56 62 / 30 40 10 10 KLFT 58 71 57 66 / 50 80 10 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
752 PM CDT MON MAR 10 2014 .DISCUSSION... AN INVERTED TROUGH IN THE GULF EASTERLIES EXTENDS FROM MARSH ISLAND TO OFFSHORE LAGUNA MADRE. INCOMING CAMPECHE AIR GENTLY ASCENDS UPON ENCOUNTERING THE TROUGH. A PACIFIC SHORTWAVE WILL TRAVEL EASTWARD ACROSS TEXAS...ENTERING SOUTHEAST TEXAS BY MIDMORNING TUESDAY. ITS ATTENDANT PVA LIFT WILL PHASE IN WITH THE UPSLIDING LIFT ATTENDING THE INVERTED TROUGH. RAIN WILL EMBEDDED SHOWERS ARE EXPECTED...MAINLY ALONG AND SOUTH OF THE I-10 CORRIDOR. JT && .PREV DISCUSSION... /ISSUED 407 PM CDT MON MAR 10 2014/ DISCUSSION... LATEST WATER VAPOR SATELLITE IMAGERY/UPPER AIR ANALYSIS SHOWED AND UPPER LOW DRIFTING EAST ACROSS NORTHERN MEXICO...WITH AN UPSTREAM SHORTWAVE TROF TRANSLATING THROUGH THE PAC NW. AT THE SFC...BROAD HIGH PRESSURE STRETCHED ACROSS THE NORTHERN GULF COAST. AFTER CONTENDING WITH AREAS OF DENSE FOG THIS MORNING...A RATHER PLEASANT DAY HAS UNFOLDED ACROSS THE REGION...WITH PLENTY OF SUN RESULTING IN TEMPERATURES CLIMBING INTO THE LOWER TO MID 70S. THE AREA OF SURFACE HIGH PRESSURE IS PROGGED TO CONTINUE SHIFTING OFF A LITTLE TO THE EAST INTO TONIGHT...ALLOWING FOR AT LEAST A WEAK RETURN FLOW TO SET UP. WITH SHELF WATER TEMPERATURES STILL IN THE MID/UPPER 50S...AREAS OF SEA FOG ARE EXPECTED TO DEVELOP THIS EVENING AS AIR CHARACTERIZED BY LOWER 60S DEWPOINTS BEGINS TO ADVECT ATOP IT. LATEST HRRR AND RUC FCSTS INDICATE FOG DEVELOPING OVER THE NEARSHORE WATERS WEST OF CAMERON...THEN DEVELOPING FARTHER NORTH/INLAND DURING THE OVERNIGHT HOURS. DREW IN AREAS OF FOG THAT GENERALLY MATCHES THIS EVOLUTION...BUT AM A LITTLE HESITANT TO ISSUE AN ADVISORY AT THIS TIME. WOULD PREFER TO LET THE EVENING CREW SEE HOW THE SITUATION BEGINS TO EVOLVE. THE UPPER LOW TO THE WEST IS EXPECTED TO CONTINUE EASTWARD...WITH SHOWERS AND THUNDERSTORMS EXPECTED TO FORM ALONG AND AHEAD OF AN ASSOCIATED N-S LOW PRESSURE TROF. MOST OF THIS ACTIVITY CONTINUES TO BE PROGGED TO OCCUR OVER THE GULF WATERS AND COASTAL AREAS ROUGHLY ALONG AND SOUTH OF I-10...AND SO THE HIGHEST POPS WERE RETAINED IN THESE AREAS. RAINFALL IS FCST TO END FROM WEST TO EAST DURING THE AFTERNOON HOURS...BUT IT IS POSSIBLE THAT ANY SEA FOG WILL PERSIST AND PERHAPS EVEN SPREAD FARTHER EAST AMID WINDS BECOMING MORE FROM THE SW. ON THE HEELS OF THIS LEAD SYSTEM...A RELATIVELY STRONG COLD FRONT IS STILL ON TRACK TO SWEEP THROUGH THE REGION LATE TUESDAY NIGHT INTO EARLY WED. THIS WILL CERTAINLY BRING AN END TO ANY SEA FOG...AND WITH SIGNIFICANT MOISTURE HAVING BEEN SHUNTED EASTWARD BY THE LEAD SYSTEM...THE PASSAGE IS EXPECTED TO BE A DRY ONE. AMID BRISK NORTH WINDS...MUCH COOLER AND DRIER AIR WILL SPILL INTO THE REGION...WITH TEMPERATURES BY THURSDAY MORNING EXPECTED TO RANGE FROM THE MID 30S OVER INTERIOR EAST TEXAS AND CENTRAL LOUISIANA TO NEAR 40 ALONG THE COAST AS THE POST-FRONTAL HIGH SETTLES SOUTH INTO TEXAS. COOL TEMPERATURES ARE EXPECTED TO CONTINUE THROUGH THURSDAY...WITH HIGHS STRUGGLING TO REACH 60 FOR MUCH OF THE AREA. AS THE HIGH SHIFTS TO THE EAST THURSDAY NIGHT...TEMPERATURES WILL BEGIN TO MODERATE...WITH A WARMING TREND CONTINUING INTO THE START OF THE WEEKEND. THE FORECAST OVER THE WEEKEND AND INTO EARLY NEXT WEEK CONTINUES TO BE ONE OF LOW CONFIDENCE...AND GENERALLY A BLEND OF THE PREVIOUS FORECAST AND LATEST WPC GUIDANCE WAS USED. 13 MARINE... WEAK TO OCCASIONALLY MODERATE EASTERLY FLOW IS EXPECTED AHEAD OF AN UPPER LEVEL LOW THAT WILL BRING SHOWERS AND THUNDERSTORMS TO THE NORTHERN GULF TONIGHT AND TUESDAY. AREAS OF FOG ARE EXPECTED TO DEVELOP OVER THE NEARSHORE WATERS FROM CAMERON TO HIGH ISLAND THIS EVENING...THEN SUBSEQUENTLY SPREAD INTO SABINE AND CALCASIEU LAKES. A STRONG COLD FRONT WILL MOVE THROUGH AREA ON WEDNESDAY. INCREASED OFFSHORE FLOW IS FORECAST FOR WEDNESDAY AND WEDNESDAY NIGHT. WINDS AND SEAS WILL LIKELY BE WITHIN SMALL CRAFT ADVISORY RANGE WEDNESDAY AND WEDNESDAY NIGHT. WINDS WILL DIMINISH ON THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION. 13 && .PRELIMINARY POINT TEMPS/POPS... KLCH 57 71 57 65 40 / 50 50 10 10 10 KBPT 56 74 57 66 40 / 60 40 10 10 10 KAEX 55 74 56 62 35 / 20 40 10 10 10 KLFT 58 70 57 66 39 / 40 80 10 10 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV WWW.TWITTER.COM/NWSLAKECHARLES WWW.YOUTUBE.COM/NWSLAKECHARLES && $$
AREA FORECAST DISCUSSION
NWS GRAY ME
1157 AM EDT SUN MAR 9 2014 .SYNOPSIS... HIGH PRESSURE CROSSES NEW ENGLAND TODAY. TWO WEAK LOW PRESSURE WAVES WILL CROSS THE AREA...ONE EARLY MONDAY...AND ONE LATE MONDAY NIGHT...THESE WILL BRING A CHANCE FOR SOME LIGHT SNOW SHOWERS TO THE REGION. HIGH PRESSURE BUILDS IN LATE TUESDAY. A PERIOD OF SNOW OR RAIN IS POSSIBLE AS LOW PRESSURE TRACKS OF THE MID ATLANTIC STATES WEDNESDAY NIGHT AND MOVES NORTHEAST ACROSS THE GULF OF MAINE ON THURSDAY. HIGH PRESSURE BUILDS SOUTH THE AREA AT THE END OF THE WEEK. && .NEAR TERM /TODAY... NOON UPDATE... HAVE RAISED HIGH TEMPERATURES BY ABOUT A DEGREE FOR MOST AREAS AS TEMPERATURES ARE NEAR FORECAST MAXIMUMS ALREADY. HOWEVER... DO NOT EXPECT A LOT OF ADDITIONAL HEATING AS COLD ADVECTION CONTINUES THROUGH THE DAY... COMBATING THE SOLAR HEATING. OTHER ADJUSTMENTS WERE TO ZERO OUT POP AND INSERT MORE CLEAR SKIES. 730AM UPDATE... QUICK UPDATE TO ADJUST GRIDS FOR CURRENT CONDITIONS. SKIES ARE MAINLY CLEAR OVER THE REGION WITH JUST SOME SCATTERED CLOUD COVER OVER THE MOUNTAINS AND ALONG THE COASTAL WATERS. ADJUSTED GRIDS FOR CURRENT DEWPOINTS AND DIURNAL CURVE BASED ON LAST NIGHTS MIN TEMPERATURES. OTHERWISE...DRY CONDITIONS WILL CONTINUE TODAY WITH BELOW NORMAL TEMPERATURES DESPITE THE NEARLY FULL SUNSHINE. DEWPOINTS WILL REMAIN VERY LOW AS WELL THROUGH THE NEAR TERM. ORIGINAL DISCUSSION... 00Z MODEL SUITE CONTINUES TO SHOW LIGHT PRECIPITATION BEING SHUNTED SOUTH OF OUR FORECAST AREA TODAY. LATEST HRRR RUN SHOWS LIGHT SNOWFALL EXITING SOUTH OF CAPE COD DURING THE 10Z-16Z TIME FRAME...LEAVING A RIDGE OF HIGH PRESSURE OVER ME/NH ALONG WITH DRY CONDITIONS. TEMPERATURES SHOULD REACH THE FREEZING MARK IN SOUTHERN AREAS DESPITE THE COLD AIR ADVECTION. THANKS TO DOWNSLOPING CONDITIONS...WITH HIGHS ONLY IN THE MID 20S IN THE MOUNTAINS. && .SHORT TERM /TONIGHT AND MONDAY/... A BROAD AREA OF WARM AIR ADVECTION BRINGS CLOUDS AND SCATTERED SNOW SHOWERS TO THE REGION TONIGHT. ATMOSPHERE IS INITIALLY VERY DRY AT THE ONSET...WITH SUBLIMATION LIKELY FOR THE FIRST PART OF THE NIGHT AS ANY SNOW SHOWERS ATTEMPT TO CROSS THE REGION EARLY. ALLOWED FOR A COMPROMISE BETWEEN THE HIGHER MET POPS AND THE DRIER MAV READINGS AS THIS WEAK AND MOISTURE STARVED SYSTEM CROSSES THE NORTHEAST. DRIER AIR WILL APPROACH FROM THE GREAT LAKES...SETTING THE STAGE FOR THE EXTENDED...MONDAY NIGHT/TUESDAY PORTION OF THE FORECAST. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... A WEAK CLIPPER WILL MOVE THRU THE REGION MONDAY NIGHT WITH SCATTERED SNOW SHOWERS. ON TUESDAY IN ITS WAKE A DRIER DOWNSLOPING NW FLOW DEVELOPS ALLOWING TEMPERATURES TO WARM INTO THE MID 30S TO MID 40S. ALL EYES ARE ON THE POTENTIAL DEVELOPMENT AND TRACK OF A COASTAL LOW THAT MODELS ARE KEYING ON FOR LATE WEDNESDAY INTO THURSDAY. MODELS ARE BACK INTO CONSENSUS OF FAVORING THE PHASING OF THE NORTHERN/SOUTHERN STREAM ENERGY THAT WOULD ALLOW SIGNIFICANT DEVELOPMENT OF A COASTAL LOW ALONG THE MID ATLANTIC COAST AND THEN TRACK INTO THE GULF OF MAINE. THE TRACK WILL BE CRITICAL FOR AMOUNTS OF SNOWFALL AND ALSO ANY RAIN/SNOW LINE THAT MAY DEVELOP ALONG THE COAST. BUT CONFIDENCE HAS INCREASED ON THE POSSIBLE SCENARIO OF THE FAVORED EURO. BASED ON THE SUPERBLEND GUIDANCE AND CONFIDENCE...WE WILL INCREASE POPS TO LIKELY FOR LATE WEDNESDAY INTO THURSDAY. THE SYSTEM WILL EXIT BY THURSDAY NIGHT FOLLOWED BY PARTIAL CLEARING. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... SHORT TERM...CEILING AND VISIBILITY MAINLY CONTINUING TO BE VFR THROUGH THE SHORT TERM PERIOD OF THE FORECAST. LONG TERM... MVFR CONDITIONS POSSIBLE IN SNOW SHOWERS MONDAY NIGHT. WIDESPREAD IFR/LIFR CONDITIONS POSSIBLE LATE WEDNESDAY INTO THURSDAY. && .MARINE... SHORT TERM...SCA FOR SEAS WILL REMAIN UP AS 5 AND 6 FOOTERS CONTINUE OVER THE COASTAL WATERS. SWAN MODEL DOING A GOOD JOB HANDLING THE SWELLS. LONG TERM... WINDS AND SEAS REMAIN BELOW SCA LEVELS THROUGH EARLY WEDNESDAY. WEDNESDAY NIGHT AND THURSDAY THE POTENTIAL EXISTS FOR POSSIBLE GALE FORCE WINDS DEPENDING ON THE TRACK OF THE COASTAL STORM. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM EDT MONDAY FOR ANZ150-152-154. && $$ NEAR TERM UPDATE... KIMBLE SHORT TERM... JC LONG TERM... RM
AREA FORECAST DISCUSSION
NWS GRAY ME
734 AM EDT SUN MAR 9 2014 .SYNOPSIS... HIGH PRESSURE CROSSES NEW ENGLAND TODAY. TWO WEAK LOW PRESSURE WAVES WILL CROSS THE AREA...ONE EARLY MONDAY...AND ONE LATE MONDAY NIGHT...THESE WILL BRING A CHANCE FOR SOME LIGHT SNOW SHOWERS TO THE REGION. HIGH PRESSURE BUILDS IN LATE TUESDAY. A PERIOD OF SNOW OR RAIN IS POSSIBLE AS LOW PRESSURE TRACKS OF THE MID ATLANTIC STATES WEDNESDAY NIGHT AND MOVES NORTHEAST ACROSS THE GULF OF MAINE ON THURSDAY. HIGH PRESSURE BUILDS SOUTH THE AREA AT THE END OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... UPDATE... QUICK UPDATE TO ADJUST GRIDS FOR CURRENT CONDITIONS. SKIES ARE MAINLY CLEAR OVER THE REGION WITH JUST SOME SCT CLOUD COVER OVER THE MOUNTAINS AND ALONG THE COASTAL WATERS. ADJUSTED GRIDS FOR CURRENT DEW POINTS AND DIURNAL CURVE BASED ON LAST NIGHTS MIN TEMPERATURES. OTHERWISE...DRY CONDITIONS WILL CONTINUE TODAY WITH BELOW NORMAL TEMPERATURES DESPITE THE NEARLY FULL SUNSHINE. DEW POINTS WILL REMAIN VERY LOW AS WELL THROUGH THE NEAR TERM. PREV DISC... 00Z MODEL SUITE CONTINUES TO SHOW LIGHT PRECIPITATION BEING SHUNTED SOUTH OF OUR FORECAST AREA TODAY. LATEST HRRR RUN SHOWS LIGHT SNOWFALL EXITING SOUTH OF CAPE COD DURING THE 10Z-16Z TIME FRAME...LEAVING A RIDGE OF HIGH PRESSURE OVER ME/NH ALONG WITH DRY CONDITIONS. TEMPERATURES SHOULD REACH THE FREEZING MARK IN SOUTHERN AREAS DESPITE THE COLD AIR ADVECTION. THANKS TO DOWNSLOPING CONDITIONS...WITH HIGHS ONLY IN THE MID 20S IN THE MOUNTAINS. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... A BROAD AREA OF WARM AIR ADVECTION BRINGS CLOUDS AND SCATTERED SNOW SHOWERS TO THE REGION TONIGHT. ATMOSPHERE IS INITIALLY VERY DRY AT THE ONSET...WITH SUBLIMATION LIKELY FOR THE FIRST PART OF THE NIGHT AS ANY -SHSN ATTEMPT TO CROSS THE REGION EARLY. ALLOWED FOR A COMPROMISE BETWEEN THE HIGHER MET POPS AND THE DRIER MAV READINGS AS THIS WEAK AND MOISTURE STARVED SYSTEM CROSSES THE NORTHEAST. DRIER AIR WILL APPROACH FROM THE GREAT LAKES...SETTING THE STAGE FOR THE EXTENDED...MONDAY NIGHT/TUESDAY PORTION OF THE FORECAST. && .LONG TERM /TUESDAY THROUGH SATURDAY/... A WEAK CLIPPER WILL MOVE THRU THE REGION MON NIGHT WITH SCT SNW SHWRS. ON TUE IN ITS WAKE A DRIER DOWNSLOPING NWLY FLOW DEVELOPS ALLOWING TEMPS TO WARM INTO THE MID 30S TO MID 40S. ALL EYES ARE ON THE POTENTIAL DEVELOPMENT AND TRACK OF A COASTAL LOW THAT MODELS ARE KEYING ON FOR LATE WED INTO THU. MODELS ARE BACK INTO CONCENSUS OF FAVORING THE PHASING OF THE NRN/SRN STREAM ENERGY THAT WOULD ALLOW SIGNIFICANT DEVELOPMENT OF A COASTAL LOW ALONG THE MID ATLANTIC COAST AND THEN TRACK INTO THE GULF OF MAINE. THE TRACK WILL BE CRITICAL FOR AMOUNTS OF SNOWFALL AND ALSO ANY RAIN/SNOW LINE THAT MAY DEVELOP ALONG THE COAST. BUT CONFIDENCE HAS INCREASED ON THE POSSIBLE SCENERIO OF THE FAVORED EURO. BASED ON THE SUPERBLEND GUID AND CONFIDENCE...WE WILL INCREASE POPS TO LKLY FOR LATE WED INTO THU. THE SYSTEM WILL EXIT BY THU NIGHT FOLLOWED BY PARTIAL CLEARING. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... SHORT TERM...CIGS AND VSBYS MAINLY CONTINUING TO BE VFR THROUGH THE SHORT TERM PERIOD OF THE FORECAST. LONG TERM... MVFR CONDS PSBL IN -SHSN MON NIGHT. WIDESPREAD IFR/LIFR CONDS PSBL LATE WED INTO THU. && .MARINE... SHORT TERM...SCA FOR SEAS WILL REMAIN UP AS 5 AND 6 FOOTERS CONTINUE OVER THE COASTAL WATERS. SWAN MODEL DOING A GOOD JOB HANDLING THE SWELLS. LONG TERM... WINDS AND SEAS REMAIN BELOW SCA LEVELS THROUGH EARLY WED. WED NIGHT AND THU THE POTENTIAL EXISTS FOR PSBL GALE FORCE WINDS DEPENDING ON THE TRACK OF THE COASTAL STORM. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM EDT MONDAY FOR ANZ150-152-154. && $$ JC
AREA FORECAST DISCUSSION
NWS GRAY ME
357 AM EDT SUN MAR 9 2014 .SYNOPSIS... HIGH PRESSURE CROSSES NEW ENGLAND TODAY. TWO WEAK LOW PRESSURE WAVES WILL CROSS THE AREA...ONE EARLY MONDAY...AND ONE LATE MONDAY NIGHT...THESE WILL BRING A CHANCE FOR SOME LIGHT SNOW SHOWERS TO THE REGION. HIGH PRESSURE BUILDS IN LATE TUESDAY. A PERIOD OF SNOW OR RAIN IS POSSIBLE AS LOW PRESSURE TRACKS OF THE MID ATLANTIC STATES WEDNESDAY NIGHT AND MOVES NORTHEAST ACROSS THE GULF OF MAINE ON THURSDAY. HIGH PRESSURE BUILDS SOUTH THE AREA AT THE END OF THE WEEK. && .NEAR TERM /THROUGH TODAY/... 00Z MODEL SUITE CONTINUES TO SHOW LIGHT PRECIPITATION BEING SHUNTED SOUTH OF OUR FORECAST AREA TODAY. LATEST HRRR RUN SHOWS LIGHT SNOWFALL EXITING SOUTH OF CAPE COD DURING THE 10Z-16Z TIME FRAME...LEAVING A RIDGE OF HIGH PRESSURE OVER ME/NH ALONG WITH DRY CONDITIONS. TEMPERATURES SHOULD REACH THE FREEZING MARK IN SOUTHERN AREAS DESPITE THE COLD AIR ADVECTION. THANKS TO DOWNSLOPING CONDITIONS...WITH HIGHS ONLY IN THE MID 20S IN THE MOUNTAINS. && .SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/... A BROAD AREA OF WARM AIR ADVECTION BRINGS CLOUDS AND SCATTERED SNOW SHOWERS TO THE REGION TONIGHT. ATMOSPHERE IS INITIALLY VERY DRY AT THE ONSET...WITH SUBLIMATION LIKELY FOR THE FIRST PART OF THE NIGHT AS ANY -SHSN ATTEMPT TO CROSS THE REGION EARLY. ALLOWED FOR A COMPROMISE BETWEEN THE HIGHER MET POPS AND THE DRIER MAV READINGS AS THIS WEAK AND MOISTURE STARVED SYSTEM CROSSES THE NORTHEAST. DRIER AIR WILL APPROACH FROM THE GREAT LAKES...SETTING THE STAGE FOR THE EXTENDED...MONDAY NIGHT/TUESDAY PORTION OF THE FORECAST. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... A WEAK CLIPPER WILL MOVE THRU THE REGION MON NIGHT WITH SCT SNW SHWRS. ON TUE IN ITS WAKE A DRIER DOWNSLOPING NWLY FLOW DEVELOPS ALLOWING TEMPS TO WARM INTO THE MID 30S TO MID 40S. ALL EYES ARE ON THE POTENTIAL DEVELOPMENT AND TRACK OF A COASTAL LOW THAT MODELS ARE KEYING ON FOR LATE WED INTO THU. MODELS ARE BACK INTO CONCENSUS OF FAVORING THE PHASING OF THE NRN/SRN STREAM ENERGY THAT WOULD ALLOW SIGNIFICANT DEVELOPMENT OF A COASTAL LOW ALONG THE MID ATLANTIC COAST AND THEN TRACK INTO THE GULF OF MAINE. THE TRACK WILL BE CRITICAL FOR AMOUNTS OF SNOWFALL AND ALSO ANY RAIN/SNOW LINE THAT MAY DEVELOP ALONG THE COAST. BUT CONFIDENCE HAS INCREASED ON THE POSSIBLE SCENERIO OF THE FAVORED EURO. BASED ON THE SUPERBLEND GUID AND CONFIDENCE...WE WILL INCREASE POPS TO LKLY FOR LATE WED INTO THU. THE SYSTEM WILL EXIT BY THU NIGHT FOLLOWED BY PARTIAL CLEARING. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... SHORT TERM...CIGS AND VSBYS MAINLY CONTINUING TO BE VFR THROUGH THE SHORT TERM PERIOD OF THE FORECAST. LONG TERM... MVFR CONDS PSBL IN -SHSN MON NIGHT. WIDESPREAD IFR/LIFR CONDS PSBL LATE WED INTO THU. && .MARINE... SHORT TERM...SCA FOR SEAS WILL REMAIN UP AS 5 AND 6 FOOTERS CONTINUE OVER THE OFFSHORE WATERS. LONG TERM... WINDS AND SEAS REMAIN BELOW SCA LEVELS THROUGH EARLY WED. WED NIGHT AND THU THE POTENTIAL EXISTS FOR PSBL GALE FORCE WINDS DEPENDING ON THE TRACK OF THE COASTAL STORM. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL MIDNIGHT EDT TONIGHT FOR ANZ150-152-154. && $$ JC/RAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
329 PM EDT SUN MAR 9 2014 LATEST UPDATE... SYNOPSIS/SHORT TERM/LONG TERM/HYDRO .SYNOPSIS... ISSUED AT 318 PM EDT SUN MAR 9 2014 A WEAK AREA OF LOW PRESSURE WILL TRACK EASTWARD THROUGH ONTARIO AND QUEBEC THROUGH MONDAY. SOUTHWEST WINDS AHEAD OF THIS SYSTEM WILL DRAW UP SOME MILDER AIR FROM THE CENTRAL PLAINS INTO MICHIGAN. A SECOND LOW PRESSURE SYSTEM WILL TRACK UP THE OHIO VALLEY TUESDAY INTO WEDNESDAY LEADING TO UNSETTLED WEATHER HERE IN LOWER MICHIGAN. A MUCH COLDER AIRMASS WILL FILTER IN BEHIND THIS SYSTEM. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 318 PM EDT SUN MAR 9 2014 THE MAIN CHALLENGE DEALS WITH THE TEMPERATURES ON MONDAY AND AMOUNT OF SNOW TUESDAY NIGHT. GUIDANCE IS QUITE LOW WITH TEMPERATURES ON MONDAY...AND THERE IS A FAIRLY STRONG SIGNAL FOR LOW CLOUDS TO FORM. FSL RUC AND HRRR RUC ARE SHOWING THESE LOW CLOUDS FORMING. IF THEY DO FORM AND HOLD THROUGH THE DAY...GUIDANCE WILL LIKELY END UP CORRECT IN SHOWING HIGHS GENERALLY IN THE LOW 40S. HOWEVER LIKE TODAY...THE LOW CLOUDS DID BREAK UP AND THAT COULD HAPPEN TOMORROW. STRONGER SOUTHWEST FLOW SHOULD HELP THIS TO HAPPEN. SO I WILL MAINTAIN THE MILD LOW 50 DEGREE TEMPERATURES. LOOKS LIKE POTENTIAL FOR PRECIPITATION ON TUESDAY IS FAIRLY LOW AS THE LIFT LOOKS WEAK AND THERE IS SOME DRY AIR BELOW THE MOIST DGZ. I WILL KEEP THE POPS AT LOW LEVELS. TUESDAY NIGHT HOWEVER...THE LOW TRACKING UP THE OH VALLEY WILL LIKELY SPREAD SNOW INTO SOUTHERN LOWER MI. SOME DECENT MID LEVEL FGEN AND DIVERGENCE IN THE UPPER LEVELS SUPPORT THIS SCENARIO. THERE IS ALSO SOME WEAKNESS IN THE STABILITY SHOWING UP AROUND THE DGZ...WHICH COULD SUPPORT A STRONGER BAND OF SNOW. WILL NEED TO MONITOR TRENDS ON THIS. I WILL MAINTAIN SEVERAL INCHES OF SNOW FOR THE I94 CORRIDOR. SOUNDINGS SUPPORT SNOW AFTER 00Z WED. .LONG TERM...(WEDNESDAY THROUGH SUNDAY) ISSUED AT 318 PM EDT SUN MAR 9 2014 THE MODEL TRENDS CONTINUE TO SHOW A STRONGER SURFACE LOW OVER THE OH VALLEY FOR WED. WITH A STRONGER SYSTEM...THE DEFORMATION ZONE IS LIABLE TO BE FURTHER NORTH AND THERE IS INCREASING CONFIDENCE THE STEADIER SNOWS WITH THIS SYSTEM WILL CLIP AT LEAST THE FAR SE CWA. SNOW ACCUMS IN CALHOUN AND JACKSON COUNTIES COULD REACH TOWARD SIX INCHES BY WED EVENING. IT APPEARS THERE SHOULD BE A SHARP CUT OFF TO THE SNOW TO THE NORTH...ESPECIALLY NORTH OF I-96. THIS CONTINUES TO BE AN EVOLVING SOLUTION AS THE NORTH AND SOUTHERN STREAM ENERGY THAT PRODUCE THIS SYSTEM WAS JUST MAKING IT ONTO THE WESTERN U.S. COAST TODAY...AND THE SOLUTION IS SUBJECT TO CHANGE. THE OTHER IMPRESSIVE ASPECT OF THIS SYSTEM IS THE COLD AIR THAT FOLLOWS IT. H8 TEMPS DIVE TO AROUND -17C...WHICH HAS TRENDED COLDER. THIS WILL PROBABLY RESULT IN STEADY OR FALLING TEMPS ON WED...INTO THE TEENS BY EVENING. THE SYSTEM LIFTS OUT QUICKLY WED NIGHT AND WITH CLEARING SKIES...MINS SHOULD DROP TO AROUND ZERO. THIS WOULD POTENTIALLY BE RECORD LEVELS. CURRENT RECORDS FOR 03/13 ARE 5F AT GRR...2F AT MKG...AND -3F AT LAN. THE REST OF THE WEEK SHOULD SEE TEMPS RETURN TO NEAR NORMAL...BUT THEN TURNING COOLER AGAIN DURING NEXT WEEKEND. NO SIGNIFICANT SYSTEMS APPEAR TO IMPACT SW MI...ALTHOUGH A SOUTHERN STREAM SYSTEM IS SHOWN OVER THE TN VALLEY BY SUNDAY WHICH COULD BRING LIGHT SNOW TO THE SOUTHERN CWA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 137 PM EDT SUN MAR 9 2014 VFR CONDITIONS WILL CONTINUE THIS AFTERNOON INTO THE EVENING ALONG WITH A BRISK SW WIND GUSTING TO AROUND 20 KNOTS. THESE WINDS WILL ONLY SLOWLY DIMINISH TOWARD MIDNIGHT. I HAVE INTRODUCED THE RISK OF LOW CLOUDS DEVELOPING OVERNIGHT. PATCHES OF STRATUS DEVELOPED THIS MORNING AND THE SET UP LOOKS SIMILAR FOR MONDAY MORNING...IN FACT THE BOUNDARY LAYER MOISTURE LOOKS EVEN HEALTHIER. FEEL ALTERNATE FUEL OR EVEN IFR CEILINGS SHOULD FORM OVER THE REGION AROUND MIDNIGHT AND LINGER A FEW HOURS PAST SUNRISE WHEN THE CLOUDS SHOULD SCATTER OUT. THE END TIME OF THE LOW CLOUDS IS SOMEWHAT IN DOUBT HOWEVER AS WE WILL NEED THE WINDS TO KICK UP AGAIN IN ORDER TO BREAK UP THE CLOUDS. THE CLOUDS COULD LINGER TOWARD MID DAY IN SOME AREAS. && .HYDROLOGY... ISSUED AT 318 PM EDT SUN MAR 9 2014 NO MAJOR PRECIPITATION SYSTEMS SEEN THROUGH THE FORECAST PERIOD. A MODERATING TREND IN THE TEMPERATURES IS PREDICTED FOR MONDAY INTO TUESDAY. THIS WILL LEAD TO GRADUAL MELTING. TEMPERATURES DO COOL DOWN FOR THE MIDDLE PART OF THE WEEK WHICH WILL SLOWLY DOWN OR STOP ANY MELTING. TEMPERATURES THEN TRY TO MODERATE FOR THE END OF THE WEEK. AS A RESULT...THE SNOWPACK WILL ONLY SLOWLY RELEASE SOME OF ITS WATER THROUGH THE PERIOD. WITH LIMITED RUNOFF WATER LEVELS SHOULD STAY FAIRLY STABLE THIS WEEK. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...MJS SHORT TERM...MJS LONG TERM...MJS AVIATION...JK HYDROLOGY...MJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
128 PM EDT SUN MAR 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 520 AM EDT SUN MAR 9 2014 WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW THROUGH THE NRN LAKES DONWSTREAM FROM A RIDGE OVER THE CANADIAN ROCKIES. A WEAK SHORTWAVE WAS LOCATED NORTH OF LAKE WINNIPEG. AT THE SFC...SRLY FLOW WAS INCREASING THROUGH THE UPPER MS VALLEY TOWARD THE WRN LAKES BETWEEN LOW PRES NEAR LAKE WINNIPEG AND A RIDGE FROM THE SRN PLAINS INTO THE SRN GREAT LAKES. IR LOOP SHOWED MID CLOUDS INCREASING WITH WAA AHEAD OF THE LOW AND WARM FRONT INTO THE ERN DAKOTAS. RADARS AND SFC INDICATED AREAS OF LIGHT SNOW OVER NW ONTARIO...NW OF THUNDERBAY...WHERE 285K-295K ISENTROPIC LIFT WAS STRONGEST. TODAY...MODELS ALONG WITH RADAR AND SATELLITE TRENDS SUGGEST THAT THE LIGHT SNOW ASSOCIATED WITH THE WAA/ISENTROPIC LIFT WILL REMAIN MAINLY TO THE NORTH OF UPPER MICHIGAN BUT MAY BRUSH THE NRN KEWEENAW AND THE FAR NE PORTION OF THE CWA. OTHERWISE...MID CLOUDS ARE EXPECTED TO INCREASE TODAY ALONG WITH THE SW WINDS. EXPECT ENOUGH INSOLATION ALONG WITH THE WAA TO BOOST TEMPS INTO THE MID 30S TO AROUND 40 OVER MOST OF THE AREA. TEMPS MAY LINGER IN THE LOWER 30S OVER THE EAST WHERE THICKER CLOUDS PREVAIL. TONIGHT...AFTER THE NRN ONTARIO MOVES OFF TOT HE EAST...THE TIGHTEST PORTION OF THE 850-700 TEMP GRADIENT WILL LINGER JUST TO THE N OF UPPER MICHIGAN. AS ISENTROPIC LIFT AND WEAK FGEN DEVELOP AHEAD OF THE NEXT SHRTWV MOVING INTO NW ONTARIO...SOME LIGHT PCPN MAY DEVELOP. MODELS HAVE BEEN CONSISTENT IN KEEPING THE BEST CHANCES NORTH OF THE CWA. HOWEVER...SLIGHT CHANCE POPS WERE INCLUDED AGAIN FOR THE KEWEENAW. WITH AN ELEVATED WARM LAYER...SOME FREEZING RAIN MAY BE POSSIBLE. HOWEVER...IF ANY PERSISTENT PCPN DOES DEVELOP...EVAPORATIVE COOLIN...WOULD LOWER TEMPS FOR MAINLY SNOW. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 428 AM EDT SUN MAR 9 2014 THE PERSISTENT EASTERN CANADIAN TROUGH AND RIDGE OVER THE WESTERN COAST OF NORTH AMERICA WILL CONTINUE THROUGH THE LONG TERM PERIOD...BUT THE EASTERN CANADIAN TROUGH/S STRENGTH SEEMS TO BE WAVERING. THIS ALLOWS FOR SOME PERIODS OF WARM UP FROM PACIFIC AIR WORKING EAST...ESPECIALLY MONDAY AND AGAIN FOR THE END OF THE WORK WEEK. CLIPPER SYSTEMS ASSOCIATED WITH THESE WARM UPS WILL GENERALLY TRACK ACROSS OR NORTH OF THE UPPER GREAT LAKES AND BRING A COUPLE DAY PERIODS OF BELOW NORMAL TEMPERATURES BEHIND THEM. THE FIRST CLIPPER SYSTEM WILL BE NEAR LAKE WINNIPEG AT 12Z MONDAY AND SLIDING THROUGH ONTARIO JUST TO THE NORTH OF THE US/CANADIAN BORDER. WITH THIS TRACK...EXPECT MUCH OF THE PRECIPITATION TO STAY TO THE NORTH OF THE CWA WHERE THE DEEPER MOISTURE AND SHORTWAVE FORCING ARE LOCATED. THIS TRACK AND EXPECTED DRY SLOT MOVING THROUGH SHOULD LEAD TO DECREASING CLOUDS THROUGH MID AFTERNOON AHEAD OF THE COLD FRONT DROPPING THROUGH ON MONDAY NIGHT. A TROUGH DOES MOVE THROUGH DURING THE DAY MONDAY AND SHIFTS WINDS TO THE WEST. EXPECT BREEZY CONDITIONS IN THE AFTERNOON...ESPECIALLY OVER THE WEST AND KEWEENAW. WIND GUSTS OVER THE WEST WILL DEPEND ON MIXING AND THAT MAY BE LIMITED WITH THE COOLING FROM THE ICE ON THE WESTERN LAKE. THAT BEING SAID...DID TREND VALUES UP SEVERAL KNOTS IN THE KEWEENAW WHERE GUSTS WILL LIKELY BE IN THE 20-30MPH RANGE. MODELS CONTINUE TO SHOW MONDAY BEING THE WARMEST DAY OF THE LONG TERM PERIOD...WITH MOST SHOWING HIGHS INTO THE 40S. THE GEM (NH/REGIONAL) CONTINUE TO INDICATE THE WARMEST TEMPERATURES...WITH HIGHS IN THE LOWER 50S FOR MUCH OF THE INTERIOR PARTS OF UPPER MICHIGAN. WITH THE AMOUNT OF CLEARING THEY ARE INDICATING THROUGH THE MORNING...THAT WOULDN/T BE OUT OF THE QUESTION. THE 12Z ECMWF AND IT/S ENSEMBLE MEMBERS ARE VERY CONSISTENT (ONLY ABOUT A 4 DEGREE SPREAD FROM THE 51 MEMBERS) ON HIGHS IN THE MID-UPPER 40S FOR THE CENTRAL/EASTERN INTERIOR LOCATIONS. GFS CONTINUES TO SHOW THE COLDEST TEMPS...BUT THAT IS LARGELY TIED TO IT KEEPING LOW CLOUDS WITH THE 850MB THERMAL GRADIENT ABOUT 120MI FARTHER SOUTHWEST THAN THE OTHER MODELS. FELT THE PREVIOUS SHIFT HAD A GOOD HANDLE ON HIGHS AND ONLY MADE MINOR TWEAKS. HIGHEST TEMPS SHOULD BE OVER THE SOUTH CENTRAL...WHERE THE INCREASING WESTERLY WINDS WILL COMBINE WITH DOWNSLOPING TO WARM TEMPS TO THE UPPER 40S AND NEAR 50. IF KIMT/KESC REACH 50 DEGREES...IT WILL BE THE FIRST TIME SINCE MID NOVEMBER (17TH). WITH THE LOW SHIFTING EAST INTO QUEBEC ON MONDAY NIGHT...COLDER AIR ALOFT WILL FILTER SOUTH ACROSS THE CWA AND LEAD TO A COOLER DAY ON TUESDAY. HIGHS WILL BE ABOUT 10-15 DEGREES COLDER AND THEN WITH THE MAIN COLD FRONT DROPPING SOUTH ACROSS THE CWA DURING THE AFTERNOON AND EVENING...SHOULD SEE TEMPS CONTINUING TO FALL THROUGH THE NIGHT AND BE WELL BELOW NORMAL ON WEDNESDAY. 850MB TEMPS ON WEDNESDAY WILL BE AROUND -21C (25C COLDER THAN MONDAY) AND THAT SHOULD ONLY PRODUCE HIGHS IN THE TEENS. HAVE TRENDED HIGHS DOWN A FEW DEGREES BASED OFF THE CONSISTENCY IN THE COLDER HIGHS ON THE ECMWF/GEM/GFS. DEEP MOISTURE IS LACKING WITH THE FRONTAL PASSAGE ON TUESDAY EVENING...BUT WITH THE AMOUNT OF LOW LEVEL MOISTURE...NORTH TO EVENTUALLY NORTHEAST WINDS BY WEDNESDAY MORNING...AND SOME BREAKS IN THE ICE ON LAKE SUPERIOR IT SHOULD LEAD TO LIGHT SNOW SHOWERS IN THE FAVORED UPSLOPE AREAS NEAR LAKE SUPERIOR. WILL PROBABLY END UP TO BE SIMILAR TO WHAT WAS SEEN LAST NIGHT...BUT WITH TEMPERATURES ALOFT BEING COLDER...SNOW RATIOS WILL LIKELY BE LOWER SINCE THE FORCING WILL BE AT THE TOP OF OR ABOVE THE DGZ. THESE SNOW SHOWERS SHOULD CONTINUE OVER THE NORTH CENTRAL AND KEWEENAW THROUGH WEDNESDAY MORNING BEFORE THE APPROACHING HIGH PRESSURE LOWERS THE INVERSION AND BRINGS DRIER AIR INTO THE AREA DURING THE AFTERNOON. LIKED THE PREVIOUS SHIFTS HANDLING OF THE POPS (LIKELYS IN THE NORTH CENTRAL HIGHER TERRAIN) AND HAVE FOLLOWED THAT WITH MINOR ADJUSTMENTS. CLEARING SKIES AND THE AREA OF HIGH PRESSURE SLIDING ACROSS UPPER MICHIGAN ON WEDNESDAY NIGHT WILL LIKELY LEAD TO A VERY COLD NIGHT ACROSS THE AREA. BOTH THE ECMWF/GEM ARE SHOWING LOWS IN THE SINGLE DIGITS AND TEENS BELOW ZERO OVER THE CENTRAL AND EASTERN PORTIONS OF THE CWA. THINK THAT SEEMS REASONABLE WITH LIGHT WINDS AND PWATS ABOUT 30 PERCENT OF NORMAL. SINCE THE GEM PERFORMS VERY WELL IN RADIATIONAL COOLING NIGHTS...HAVE DROPPED LOWS A GOOD 7-15 DEGREES AND CLOSER TO IT/S VALUES. WITH THE TEMPERATURE FALLING BELOW ZERO THIS PAST EVENING AND CONTINUING INTO THE EARLY MORNING HOURS...WE HAVE PUSHED OUR SUB ZERO DAYS TO 56. THINKING IT WILL COOL OFF FAST ENOUGH ON WEDNESDAY EVENING TO ADD BOTH WEDNESDAY AND THURSDAY TO THE SUB ZERO DAYS AND IF THAT OCCURS IT WOULD BREAK THE RECORD OF 57 DAYS (SET IN 1962-63) AT OUR OFFICE. WITH THE HIGH QUICKLY SHIFTING EAST LATE WEDNESDAY NIGHT AND THURSDAY MORNING...RETURN SOUTHERLY FLOW WILL DEVELOP AND LEAD TO TEMPERATURES QUICKLY WARMING. THE WARM AIR ADVECTION REGIME AHEAD OF THE NEXT CLIPPER SYSTEM SHOULD ALLOW HIGHS ON THURSDAY TO RISE INTO THE LOWER 20S EAST AND LOWER 30S WEST. THERE IS THE POTENTIAL FOR SOME LIGHT PRECIP ON THURSDAY OVER THE WESTERN CWA WITH THE WAA...SO ADDED SLIGHT CHANCE POPS TO THE WEST AND CENTRAL CWA ON THURSDAY. MODELS IN DECENT AGREEMENT IN MOVING THE CLIPPER THROUGH THE UPPER GREAT LAKES REGION BETWEEN THURSDAY NIGHT AND FRIDAY...ALTHOUGH THEY DIFFER ON THE EXACT TRACK. AT THIS POINT...LOOKS LIKE BEST PRECIP WILL BE OVER THE NORTHERN HALF OF THE CWA LIKE THE LAST TWO SYSTEMS. ONCE AGAIN...THIS SYSTEM WILL DROP A COLD FRONT ACROSS THE AREA ON FRIDAY NIGHT AND BRING THE COLDER AIR BACK INTO THE AREA FOR SATURDAY AND PRODUCE ANOTHER OPPORTUNITY FOR LIGHT SNOW NEAR LAKE SUPERIOR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 128 PM EDT SUN MAR 9 2014 THE PROBABILITY OF MVFR CEILINGS INCREASE SIGNIFICANTLY AFTER 03Z MONDAY...WITH THE BEST CHANCE FROM 09-15Z MONDAY. DAYTIME HEATING AND INCREASING W WINDS SHOULD BE ENOUGH TO HELP SCOUR OUT SOME OF THE LOWER LEVEL MOISTURE /STUCK AT OR BELOW 4KFT/ DURING THE DAY. THIS WILL BE DESPITE THE INCREASING SFC TEMPS INTO THE MID TO UPPER 40S OVER W UPPER MI AND DEW POINTS MOVING INTO THE LOW 30S. ADVECTION FOG WILL BE POSSIBLE...BUT WILL KEEP LOWER CEILINGS/VIS OUT OF THE FCST FOR NOW DUE TO LOW CONFIDENCE. THE BEST CHANCE OF FOG TO IFR CONDITION WOULD BE AT SAW THROUGH MID MORNING WITH S-SW WINDS BEFORE THEY INCREASE SIGNIFICANTLY OUT OF THE W. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 520 AM EDT SUN MAR 9 2014 GUSTY SW WINDS TO 25 KNOTS ARE EXPECTED TODAY AS LOW PRES MOVES THROUGH NRN ONTARIO. AFTER WINDS DIMINISH TONIGHT...EXPECT SW WINDS TO AGAIN INCREASE TO 25 KNOTS WITH SOUTH OF ANOTHER LOW PRES SYSTEM. N WINDS OF 20 TO 25 KNOTS ARE FCST TUE INTO TUE NIGHT AS ARCTIC HIGH PRES BUILDS INTO THE NRN LAKES. OTHERWISE...WINDS WILL REMAIN BELOW 20 KNOTS THROUGH THE REST OF THE WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...KF MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
755 AM EDT SUN MAR 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 520 AM EDT SUN MAR 9 2014 WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW THROUGH THE NRN LAKES DONWSTREAM FROM A RIDGE OVER THE CANADIAN ROCKIES. A WEAK SHORTWAVE WAS LOCATED NORTH OF LAKE WINNIPEG. AT THE SFC...SRLY FLOW WAS INCREASING THROUGH THE UPPER MS VALLEY TOWARD THE WRN LAKES BETWEEN LOW PRES NEAR LAKE WINNIPEG AND A RIDGE FROM THE SRN PLAINS INTO THE SRN GREAT LAKES. IR LOOP SHOWED MID CLOUDS INCREASING WITH WAA AHEAD OF THE LOW AND WARM FRONT INTO THE ERN DAKOTAS. RADARS AND SFC INDICATED AREAS OF LIGHT SNOW OVER NW ONTARIO...NW OF THUNDERBAY...WHERE 285K-295K ISENTROPIC LIFT WAS STRONGEST. TODAY...MODELS ALONG WITH RADAR AND SATELLITE TRENDS SUGGEST THAT THE LIGHT SNOW ASSOCIATED WITH THE WAA/ISENTROPIC LIFT WILL REMAIN MAINLY TO THE NORTH OF UPPER MICHIGAN BUT MAY BRUSH THE NRN KEWEENAW AND THE FAR NE PORTION OF THE CWA. OTHERWISE...MID CLOUDS ARE EXPECTED TO INCREASE TODAY ALONG WITH THE SW WINDS. EXPECT ENOUGH INSOLATION ALONG WITH THE WAA TO BOOST TEMPS INTO THE MID 30S TO AROUND 40 OVER MOST OF THE AREA. TEMPS MAY LINGER IN THE LOWER 30S OVER THE EAST WHERE THICKER CLOUDS PREVAIL. TONIGHT...AFTER THE NRN ONTARIO MOVES OFF TOT HE EAST...THE TIGHTEST PORTION OF THE 850-700 TEMP GRADIENT WILL LINGER JUST TO THE N OF UPPER MICHIGAN. AS ISENTROPIC LIFT AND WEAK FGEN DEVELOP AHEAD OF THE NEXT SHRTWV MOVING INTO NW ONTARIO...SOME LIGHT PCPN MAY DEVELOP. MODELS HAVE BEEN CONSISTENT IN KEEPING THE BEST CHANCES NORTH OF THE CWA. HOWEVER...SLIGHT CHANCE POPS WERE INCLUDED AGAIN FOR THE KEWEENAW. WITH AN ELEVATED WARM LAYER...SOME FREEZING RAIN MAY BE POSSIBLE. HOWEVER...IF ANY PERSISTENT PCPN DOES DEVELOP...EVAPORATIVE COOLIN...WOULD LOWER TEMPS FOR MAINLY SNOW. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 428 AM EDT SUN MAR 9 2014 THE PERSISTENT EASTERN CANADIAN TROUGH AND RIDGE OVER THE WESTERN COAST OF NORTH AMERICA WILL CONTINUE THROUGH THE LONG TERM PERIOD...BUT THE EASTERN CANADIAN TROUGH/S STRENGTH SEEMS TO BE WAVERING. THIS ALLOWS FOR SOME PERIODS OF WARM UP FROM PACIFIC AIR WORKING EAST...ESPECIALLY MONDAY AND AGAIN FOR THE END OF THE WORK WEEK. CLIPPER SYSTEMS ASSOCIATED WITH THESE WARM UPS WILL GENERALLY TRACK ACROSS OR NORTH OF THE UPPER GREAT LAKES AND BRING A COUPLE DAY PERIODS OF BELOW NORMAL TEMPERATURES BEHIND THEM. THE FIRST CLIPPER SYSTEM WILL BE NEAR LAKE WINNIPEG AT 12Z MONDAY AND SLIDING THROUGH ONTARIO JUST TO THE NORTH OF THE US/CANADIAN BORDER. WITH THIS TRACK...EXPECT MUCH OF THE PRECIPITATION TO STAY TO THE NORTH OF THE CWA WHERE THE DEEPER MOISTURE AND SHORTWAVE FORCING ARE LOCATED. THIS TRACK AND EXPECTED DRY SLOT MOVING THROUGH SHOULD LEAD TO DECREASING CLOUDS THROUGH MID AFTERNOON AHEAD OF THE COLD FRONT DROPPING THROUGH ON MONDAY NIGHT. A TROUGH DOES MOVE THROUGH DURING THE DAY MONDAY AND SHIFTS WINDS TO THE WEST. EXPECT BREEZY CONDITIONS IN THE AFTERNOON...ESPECIALLY OVER THE WEST AND KEWEENAW. WIND GUSTS OVER THE WEST WILL DEPEND ON MIXING AND THAT MAY BE LIMITED WITH THE COOLING FROM THE ICE ON THE WESTERN LAKE. THAT BEING SAID...DID TREND VALUES UP SEVERAL KNOTS IN THE KEWEENAW WHERE GUSTS WILL LIKELY BE IN THE 20-30MPH RANGE. MODELS CONTINUE TO SHOW MONDAY BEING THE WARMEST DAY OF THE LONG TERM PERIOD...WITH MOST SHOWING HIGHS INTO THE 40S. THE GEM (NH/REGIONAL) CONTINUE TO INDICATE THE WARMEST TEMPERATURES...WITH HIGHS IN THE LOWER 50S FOR MUCH OF THE INTERIOR PARTS OF UPPER MICHIGAN. WITH THE AMOUNT OF CLEARING THEY ARE INDICATING THROUGH THE MORNING...THAT WOULDN/T BE OUT OF THE QUESTION. THE 12Z ECMWF AND IT/S ENSEMBLE MEMBERS ARE VERY CONSISTENT (ONLY ABOUT A 4 DEGREE SPREAD FROM THE 51 MEMBERS) ON HIGHS IN THE MID-UPPER 40S FOR THE CENTRAL/EASTERN INTERIOR LOCATIONS. GFS CONTINUES TO SHOW THE COLDEST TEMPS...BUT THAT IS LARGELY TIED TO IT KEEPING LOW CLOUDS WITH THE 850MB THERMAL GRADIENT ABOUT 120MI FARTHER SOUTHWEST THAN THE OTHER MODELS. FELT THE PREVIOUS SHIFT HAD A GOOD HANDLE ON HIGHS AND ONLY MADE MINOR TWEAKS. HIGHEST TEMPS SHOULD BE OVER THE SOUTH CENTRAL...WHERE THE INCREASING WESTERLY WINDS WILL COMBINE WITH DOWNSLOPING TO WARM TEMPS TO THE UPPER 40S AND NEAR 50. IF KIMT/KESC REACH 50 DEGREES...IT WILL BE THE FIRST TIME SINCE MID NOVEMBER (17TH). WITH THE LOW SHIFTING EAST INTO QUEBEC ON MONDAY NIGHT...COLDER AIR ALOFT WILL FILTER SOUTH ACROSS THE CWA AND LEAD TO A COOLER DAY ON TUESDAY. HIGHS WILL BE ABOUT 10-15 DEGREES COLDER AND THEN WITH THE MAIN COLD FRONT DROPPING SOUTH ACROSS THE CWA DURING THE AFTERNOON AND EVENING...SHOULD SEE TEMPS CONTINUING TO FALL THROUGH THE NIGHT AND BE WELL BELOW NORMAL ON WEDNESDAY. 850MB TEMPS ON WEDNESDAY WILL BE AROUND -21C (25C COLDER THAN MONDAY) AND THAT SHOULD ONLY PRODUCE HIGHS IN THE TEENS. HAVE TRENDED HIGHS DOWN A FEW DEGREES BASED OFF THE CONSISTENCY IN THE COLDER HIGHS ON THE ECMWF/GEM/GFS. DEEP MOISTURE IS LACKING WITH THE FRONTAL PASSAGE ON TUESDAY EVENING...BUT WITH THE AMOUNT OF LOW LEVEL MOISTURE...NORTH TO EVENTUALLY NORTHEAST WINDS BY WEDNESDAY MORNING...AND SOME BREAKS IN THE ICE ON LAKE SUPERIOR IT SHOULD LEAD TO LIGHT SNOW SHOWERS IN THE FAVORED UPSLOPE AREAS NEAR LAKE SUPERIOR. WILL PROBABLY END UP TO BE SIMILAR TO WHAT WAS SEEN LAST NIGHT...BUT WITH TEMPERATURES ALOFT BEING COLDER...SNOW RATIOS WILL LIKELY BE LOWER SINCE THE FORCING WILL BE AT THE TOP OF OR ABOVE THE DGZ. THESE SNOW SHOWERS SHOULD CONTINUE OVER THE NORTH CENTRAL AND KEWEENAW THROUGH WEDNESDAY MORNING BEFORE THE APPROACHING HIGH PRESSURE LOWERS THE INVERSION AND BRINGS DRIER AIR INTO THE AREA DURING THE AFTERNOON. LIKED THE PREVIOUS SHIFTS HANDLING OF THE POPS (LIKELYS IN THE NORTH CENTRAL HIGHER TERRAIN) AND HAVE FOLLOWED THAT WITH MINOR ADJUSTMENTS. CLEARING SKIES AND THE AREA OF HIGH PRESSURE SLIDING ACROSS UPPER MICHIGAN ON WEDNESDAY NIGHT WILL LIKELY LEAD TO A VERY COLD NIGHT ACROSS THE AREA. BOTH THE ECMWF/GEM ARE SHOWING LOWS IN THE SINGLE DIGITS AND TEENS BELOW ZERO OVER THE CENTRAL AND EASTERN PORTIONS OF THE CWA. THINK THAT SEEMS REASONABLE WITH LIGHT WINDS AND PWATS ABOUT 30 PERCENT OF NORMAL. SINCE THE GEM PERFORMS VERY WELL IN RADIATIONAL COOLING NIGHTS...HAVE DROPPED LOWS A GOOD 7-15 DEGREES AND CLOSER TO IT/S VALUES. WITH THE TEMPERATURE FALLING BELOW ZERO THIS PAST EVENING AND CONTINUING INTO THE EARLY MORNING HOURS...WE HAVE PUSHED OUR SUB ZERO DAYS TO 56. THINKING IT WILL COOL OFF FAST ENOUGH ON WEDNESDAY EVENING TO ADD BOTH WEDNESDAY AND THURSDAY TO THE SUB ZERO DAYS AND IF THAT OCCURS IT WOULD BREAK THE RECORD OF 57 DAYS (SET IN 1962-63) AT OUR OFFICE. WITH THE HIGH QUICKLY SHIFTING EAST LATE WEDNESDAY NIGHT AND THURSDAY MORNING...RETURN SOUTHERLY FLOW WILL DEVELOP AND LEAD TO TEMPERATURES QUICKLY WARMING. THE WARM AIR ADVECTION REGIME AHEAD OF THE NEXT CLIPPER SYSTEM SHOULD ALLOW HIGHS ON THURSDAY TO RISE INTO THE LOWER 20S EAST AND LOWER 30S WEST. THERE IS THE POTENTIAL FOR SOME LIGHT PRECIP ON THURSDAY OVER THE WESTERN CWA WITH THE WAA...SO ADDED SLIGHT CHANCE POPS TO THE WEST AND CENTRAL CWA ON THURSDAY. MODELS IN DECENT AGREEMENT IN MOVING THE CLIPPER THROUGH THE UPPER GREAT LAKES REGION BETWEEN THURSDAY NIGHT AND FRIDAY...ALTHOUGH THEY DIFFER ON THE EXACT TRACK. AT THIS POINT...LOOKS LIKE BEST PRECIP WILL BE OVER THE NORTHERN HALF OF THE CWA LIKE THE LAST TWO SYSTEMS. ONCE AGAIN...THIS SYSTEM WILL DROP A COLD FRONT ACROSS THE AREA ON FRIDAY NIGHT AND BRING THE COLDER AIR BACK INTO THE AREA FOR SATURDAY AND PRODUCE ANOTHER OPPORTUNITY FOR LIGHT SNOW NEAR LAKE SUPERIOR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 755 AM EDT SUN MAR 9 2014 WAA AHEAD OF A LOW PRESSURE SYSTEM AND WARM FRONT WILL CAUSE INCREASING MID CLOUDS TODAY BUT VFR CONDITIONS ARE EXPECTED THROUGH THIS EVENING. INCREASING LOW LEVEL MOISTURE LATE TONIGHT WITH CONTINUED SRLY FLOW WILL BRING MVFR CIGS AND SOME REDUCTION IN VSBY WITH FOG. IFR CONDITIONS MAY ALSO BE POSSIBLE AT SAW...WITH MORE OF AN UPSLOPE COMPONENT BUT CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE AT THIS TIME. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 520 AM EDT SUN MAR 9 2014 GUSTY SW WINDS TO 25 KNOTS ARE EXPECTED TODAY AS LOW PRES MOVES THROUGH NRN ONTARIO. AFTER WINDS DIMINISH TONIGHT...EXPECT SW WINDS TO AGAIN INCREASE TO 25 KNOTS WITH SOUTH OF ANOTHER LOW PRES SYSTEM. N WINDS OF 20 TO 25 KNOTS ARE FCST TUE INTO TUE NIGHT AS ARCTIC HIGH PRES BUILDS INTO THE NRN LAKES. OTHERWISE...WINDS WILL REMAIN BELOW 20 KNOTS THROUGH THE REST OF THE WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
522 AM EDT SUN MAR 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 520 AM EDT SUN MAR 9 2014 WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW THROUGH THE NRN LAKES DONWSTREAM FROM A RIDGE OVER THE CANADIAN ROCKIES. A WEAK SHORTWAVE WAS LOCATED NORTH OF LAKE WINNIPEG. AT THE SFC...SRLY FLOW WAS INCREASING THROUGH THE UPPER MS VALLEY TOWARD THE WRN LAKES BETWEEN LOW PRES NEAR LAKE WINNIPEG AND A RIDGE FROM THE SRN PLAINS INTO THE SRN GREAT LAKES. IR LOOP SHOWED MID CLOUDS INCREASING WITH WAA AHEAD OF THE LOW AND WARM FRONT INTO THE ERN DAKOTAS. RADARS AND SFC INDICATED AREAS OF LIGHT SNOW OVER NW ONTARIO...NW OF THUNDERBAY...WHERE 285K-295K ISENTROPIC LIFT WAS STRONGEST. TODAY...MODELS ALONG WITH RADAR AND SATELLITE TRENDS SUGGEST THAT THE LIGHT SNOW ASSOCIATED WITH THE WAA/ISENTROPIC LIFT WILL REMAIN MAINLY TO THE NORTH OF UPPER MICHIGAN BUT MAY BRUSH THE NRN KEWEENAW AND THE FAR NE PORTION OF THE CWA. OTHERWISE...MID CLOUDS ARE EXPECTED TO INCREASE TODAY ALONG WITH THE SW WINDS. EXPECT ENOUGH INSOLATION ALONG WITH THE WAA TO BOOST TEMPS INTO THE MID 30S TO AROUND 40 OVER MOST OF THE AREA. TEMPS MAY LINGER IN THE LOWER 30S OVER THE EAST WHERE THICKER CLOUDS PREVAIL. TONIGHT...AFTER THE NRN ONTARIO MOVES OFF TOT HE EAST...THE TIGHTEST PORTION OF THE 850-700 TEMP GRADIENT WILL LINGER JUST TO THE N OF UPPER MICHIGAN. AS ISENTROPIC LIFT AND WEAK FGEN DEVELOP AHEAD OF THE NEXT SHRTWV MOVING INTO NW ONTARIO...SOME LIGHT PCPN MAY DEVELOP. MODELS HAVE BEEN CONSISTENT IN KEEPING THE BEST CHANCES NORTH OF THE CWA. HOWEVER...SLIGHT CHANCE POPS WERE INCLUDED AGAIN FOR THE KEWEENAW. WITH AN ELEVATED WARM LAYER...SOME FREEZING RAIN MAY BE POSSIBLE. HOWEVER...IF ANY PERSISTENT PCPN DOES DEVELOP...EVAPORATIVE COOLIN...WOULD LOWER TEMPS FOR MAINLY SNOW. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 428 AM EDT SUN MAR 9 2014 THE PERSISTENT EASTERN CANADIAN TROUGH AND RIDGE OVER THE WESTERN COAST OF NORTH AMERICA WILL CONTINUE THROUGH THE LONG TERM PERIOD...BUT THE EASTERN CANADIAN TROUGH/S STRENGTH SEEMS TO BE WAVERING. THIS ALLOWS FOR SOME PERIODS OF WARM UP FROM PACIFIC AIR WORKING EAST...ESPECIALLY MONDAY AND AGAIN FOR THE END OF THE WORK WEEK. CLIPPER SYSTEMS ASSOCIATED WITH THESE WARM UPS WILL GENERALLY TRACK ACROSS OR NORTH OF THE UPPER GREAT LAKES AND BRING A COUPLE DAY PERIODS OF BELOW NORMAL TEMPERATURES BEHIND THEM. THE FIRST CLIPPER SYSTEM WILL BE NEAR LAKE WINNIPEG AT 12Z MONDAY AND SLIDING THROUGH ONTARIO JUST TO THE NORTH OF THE US/CANADIAN BORDER. WITH THIS TRACK...EXPECT MUCH OF THE PRECIPITATION TO STAY TO THE NORTH OF THE CWA WHERE THE DEEPER MOISTURE AND SHORTWAVE FORCING ARE LOCATED. THIS TRACK AND EXPECTED DRY SLOT MOVING THROUGH SHOULD LEAD TO DECREASING CLOUDS THROUGH MID AFTERNOON AHEAD OF THE COLD FRONT DROPPING THROUGH ON MONDAY NIGHT. A TROUGH DOES MOVE THROUGH DURING THE DAY MONDAY AND SHIFTS WINDS TO THE WEST. EXPECT BREEZY CONDITIONS IN THE AFTERNOON...ESPECIALLY OVER THE WEST AND KEWEENAW. WIND GUSTS OVER THE WEST WILL DEPEND ON MIXING AND THAT MAY BE LIMITED WITH THE COOLING FROM THE ICE ON THE WESTERN LAKE. THAT BEING SAID...DID TREND VALUES UP SEVERAL KNOTS IN THE KEWEENAW WHERE GUSTS WILL LIKELY BE IN THE 20-30MPH RANGE. MODELS CONTINUE TO SHOW MONDAY BEING THE WARMEST DAY OF THE LONG TERM PERIOD...WITH MOST SHOWING HIGHS INTO THE 40S. THE GEM (NH/REGIONAL) CONTINUE TO INDICATE THE WARMEST TEMPERATURES...WITH HIGHS IN THE LOWER 50S FOR MUCH OF THE INTERIOR PARTS OF UPPER MICHIGAN. WITH THE AMOUNT OF CLEARING THEY ARE INDICATING THROUGH THE MORNING...THAT WOULDN/T BE OUT OF THE QUESTION. THE 12Z ECMWF AND IT/S ENSEMBLE MEMBERS ARE VERY CONSISTENT (ONLY ABOUT A 4 DEGREE SPREAD FROM THE 51 MEMBERS) ON HIGHS IN THE MID-UPPER 40S FOR THE CENTRAL/EASTERN INTERIOR LOCATIONS. GFS CONTINUES TO SHOW THE COLDEST TEMPS...BUT THAT IS LARGELY TIED TO IT KEEPING LOW CLOUDS WITH THE 850MB THERMAL GRADIENT ABOUT 120MI FARTHER SOUTHWEST THAN THE OTHER MODELS. FELT THE PREVIOUS SHIFT HAD A GOOD HANDLE ON HIGHS AND ONLY MADE MINOR TWEAKS. HIGHEST TEMPS SHOULD BE OVER THE SOUTH CENTRAL...WHERE THE INCREASING WESTERLY WINDS WILL COMBINE WITH DOWNSLOPING TO WARM TEMPS TO THE UPPER 40S AND NEAR 50. IF KIMT/KESC REACH 50 DEGREES...IT WILL BE THE FIRST TIME SINCE MID NOVEMBER (17TH). WITH THE LOW SHIFTING EAST INTO QUEBEC ON MONDAY NIGHT...COLDER AIR ALOFT WILL FILTER SOUTH ACROSS THE CWA AND LEAD TO A COOLER DAY ON TUESDAY. HIGHS WILL BE ABOUT 10-15 DEGREES COLDER AND THEN WITH THE MAIN COLD FRONT DROPPING SOUTH ACROSS THE CWA DURING THE AFTERNOON AND EVENING...SHOULD SEE TEMPS CONTINUING TO FALL THROUGH THE NIGHT AND BE WELL BELOW NORMAL ON WEDNESDAY. 850MB TEMPS ON WEDNESDAY WILL BE AROUND -21C (25C COLDER THAN MONDAY) AND THAT SHOULD ONLY PRODUCE HIGHS IN THE TEENS. HAVE TRENDED HIGHS DOWN A FEW DEGREES BASED OFF THE CONSISTENCY IN THE COLDER HIGHS ON THE ECMWF/GEM/GFS. DEEP MOISTURE IS LACKING WITH THE FRONTAL PASSAGE ON TUESDAY EVENING...BUT WITH THE AMOUNT OF LOW LEVEL MOISTURE...NORTH TO EVENTUALLY NORTHEAST WINDS BY WEDNESDAY MORNING...AND SOME BREAKS IN THE ICE ON LAKE SUPERIOR IT SHOULD LEAD TO LIGHT SNOW SHOWERS IN THE FAVORED UPSLOPE AREAS NEAR LAKE SUPERIOR. WILL PROBABLY END UP TO BE SIMILAR TO WHAT WAS SEEN LAST NIGHT...BUT WITH TEMPERATURES ALOFT BEING COLDER...SNOW RATIOS WILL LIKELY BE LOWER SINCE THE FORCING WILL BE AT THE TOP OF OR ABOVE THE DGZ. THESE SNOW SHOWERS SHOULD CONTINUE OVER THE NORTH CENTRAL AND KEWEENAW THROUGH WEDNESDAY MORNING BEFORE THE APPROACHING HIGH PRESSURE LOWERS THE INVERSION AND BRINGS DRIER AIR INTO THE AREA DURING THE AFTERNOON. LIKED THE PREVIOUS SHIFTS HANDLING OF THE POPS (LIKELYS IN THE NORTH CENTRAL HIGHER TERRAIN) AND HAVE FOLLOWED THAT WITH MINOR ADJUSTMENTS. CLEARING SKIES AND THE AREA OF HIGH PRESSURE SLIDING ACROSS UPPER MICHIGAN ON WEDNESDAY NIGHT WILL LIKELY LEAD TO A VERY COLD NIGHT ACROSS THE AREA. BOTH THE ECMWF/GEM ARE SHOWING LOWS IN THE SINGLE DIGITS AND TEENS BELOW ZERO OVER THE CENTRAL AND EASTERN PORTIONS OF THE CWA. THINK THAT SEEMS REASONABLE WITH LIGHT WINDS AND PWATS ABOUT 30 PERCENT OF NORMAL. SINCE THE GEM PERFORMS VERY WELL IN RADIATIONAL COOLING NIGHTS...HAVE DROPPED LOWS A GOOD 7-15 DEGREES AND CLOSER TO IT/S VALUES. WITH THE TEMPERATURE FALLING BELOW ZERO THIS PAST EVENING AND CONTINUING INTO THE EARLY MORNING HOURS...WE HAVE PUSHED OUR SUB ZERO DAYS TO 56. THINKING IT WILL COOL OFF FAST ENOUGH ON WEDNESDAY EVENING TO ADD BOTH WEDNESDAY AND THURSDAY TO THE SUB ZERO DAYS AND IF THAT OCCURS IT WOULD BREAK THE RECORD OF 57 DAYS (SET IN 1962-63) AT OUR OFFICE. WITH THE HIGH QUICKLY SHIFTING EAST LATE WEDNESDAY NIGHT AND THURSDAY MORNING...RETURN SOUTHERLY FLOW WILL DEVELOP AND LEAD TO TEMPERATURES QUICKLY WARMING. THE WARM AIR ADVECTION REGIME AHEAD OF THE NEXT CLIPPER SYSTEM SHOULD ALLOW HIGHS ON THURSDAY TO RISE INTO THE LOWER 20S EAST AND LOWER 30S WEST. THERE IS THE POTENTIAL FOR SOME LIGHT PRECIP ON THURSDAY OVER THE WESTERN CWA WITH THE WAA...SO ADDED SLIGHT CHANCE POPS TO THE WEST AND CENTRAL CWA ON THURSDAY. MODELS IN DECENT AGREEMENT IN MOVING THE CLIPPER THROUGH THE UPPER GREAT LAKES REGION BETWEEN THURSDAY NIGHT AND FRIDAY...ALTHOUGH THEY DIFFER ON THE EXACT TRACK. AT THIS POINT...LOOKS LIKE BEST PRECIP WILL BE OVER THE NORTHERN HALF OF THE CWA LIKE THE LAST TWO SYSTEMS. ONCE AGAIN...THIS SYSTEM WILL DROP A COLD FRONT ACROSS THE AREA ON FRIDAY NIGHT AND BRING THE COLDER AIR BACK INTO THE AREA FOR SATURDAY AND PRODUCE ANOTHER OPPORTUNITY FOR LIGHT SNOW NEAR LAKE SUPERIOR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 114 AM EDT SUN MAR 9 2014 A HIGH PRESSURE RIDGE OVER UPPER MI WILL SLIDE EAST LATE TONIGHT AS A LOW PRESSURE SYSTEM MOVES INTO THE NRN PLAINS. TIGHTENING GRADIENT AHEAD OF THIS LOW WILL ALLOW FOR INCREASING SW WINDS BY SUN MORNING WITH GUSTS NEARING 20-25KTS BY MIDDAY AT BOTH IWD AND SAW. NOT EXPECTING LLWS TO BE AN ISSUE AS STRONGEST WSW WINDS TO NEAR 50 KT BTWN 1.5-2 KFT WILL BE OCCURRING BY LATE SUN MORNING WHEN MIXING AND GUSTS START OCCURRING AT THE SFC. WAA WILL CAUSE INCREASING MID CLOUDS BY LATE TONIGHT/SUNDAY MORNING BUT VFR CONDITIONS ARE EXPECTED THRU PD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 520 AM EDT SUN MAR 9 2014 GUSTY SW WINDS TO 25 KNOTS ARE EXPECTED TODAY AS LOW PRES MOVES THROUGH NRN ONTARIO. AFTER WINDS DIMINISH TONIGHT...EXPECT SW WINDS TO AGAIN INCREASE TO 25 KNOTS WITH SOUTH OF ANOTHER LOW PRES SYSTEM. N WINDS OF 20 TO 25 KNOTS ARE FCST TUE INTO TUE NIGHT AS ARCTIC HIGH PRES BUILDS INTO THE NRN LAKES. OTHERWISE...WINDS WILL REMAIN BELOW 20 KNOTS THROUGH THE REST OF THE WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...VOSS MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1202 AM EST SUN MAR 9 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 230 PM EST SAT MAR 8 2014 AN AREA OF HIGH PRESSURE OVER THE CENTRAL PLAINS WILL BUILD EAST THROUGH SUNDAY. THIS SYSTEM WILL PROVIDE FAIR WEATHER TO THE GREAT LAKES REGION. WEAK LOW PRESSURE WILL TRACK EASTWARD THROUGH THE NORTHERN GREAT LAKES REGION MONDAY. A COOLER AIRMASS WILL FILTER IN BEHIND THIS SYSTEM FOR TUESDAY INTO WEDNESDAY. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 230 PM EST SAT MAR 8 2014 THE MAIN FORECAST CHALLENGE DEALS WITH THE RISK FOR PRECIPITATION. CHANCES OVERALL REMAIN LOW AND NO MAJOR CHANGES TO THE FORECAST WITH THIS ISSUANCE. SUNDAY NIGHT ONE MID LEVEL SHORTWAVE TRACKS RAPIDLY SOUTHEASTWARD THROUGH LAKE SUPERIOR. THERE IS SOME MOISTENING OF THE DGZ...AND LIFT FROM THE WAVE HERE IN SW LOWER MI. GIVEN THE TRACK OF THIS SYSTEM...I WILL FEATURE LOW POPS FOR THE REGION NORTH OF A HART TO MOUNT PLEASANT LINE. FURTHER SOUTH...AT THIS POINT LITTLE OR NO LIFT AROUND TO SUPPORT ADDING POPS. WE WILL NEED TO MONITOR MONDAY NIGHT FOR POSSIBLY ADDING PRECIPITATION TO THE FORECAST. NAM AND HIGH RES EURO KEEP IT DRY...BUT THE GFS IS SHOWING THE DGZ BECOMING MOIST. THIS IS RELATED TO MID LEVEL FGEN WITH IS STRONGER WITH THE GFS. I HELD OFF ON MENTIONING PRECIPITATION GIVEN THE GFS SEEMS TO BE AN OUTLIER. WITH SKIES CLEARING OUT THIS EVENING...DEWPOINTS ARE ELEVATED COMPARED TO FORECASTED LOW TEMPERATURES. AS A RESULT WE MAY SEE SOME FOG/STRATUS TRYING TO DEVELOP VERY LATE. NAM AND HRRR MODELS ARE SHOWING THIS. I ADDED IT TO THE FORECAST. .LONG TERM...(TUESDAY THROUGH SATURDAY) ISSUED AT 230 PM EST SAT MAR 8 2014 IT STILL APPEARS THE MID WEEK SYSTEM WILL TRACK ALONG THE OHIO RIVER VALLEY...LEAVING SOUTHERN LOWER MICHIGAN ON THE NORTHERN FRINGES OF THIS SYSTEM. THE PCPN COULD START TUESDAY AFTERNOON ALONG AND SOUTH OF I-96 ALONG A REGION OF FGEN. THEN THE PCPN SHOULD EXPAND AND CONTINUE INTO TUESDAY NIGHT AND WEDNESDAY AS THE LOW PASSES TO OUR SOUTH. THROUGH MIDNIGHT TUESDAY NIGHT RAIN AND/OR SNOW COULD OCCUR...WITH MAINLY SNOW FROM MIDNIGHT TUESDAY NIGHT ONWARD. BEING THE NORTHERN FRINGE SHOULD GIVE THE AREA MOSTLY LIGHT SNOW...WITH LESS THAN AN INCH EXPECTED FOR I-96...UP TO TWO INCHES OVER THE FAR SE CWA...TOWARD JXN. ONCE THIS SYSTEM GOES BY THE REST OF THE LONG TERM APPEARS TO BE QUIET. A CLIPPER SYSTEM GOES BY TO OUR NORTH ON FRIDAY...BUT THE BEST MOISTURE REMAINS NORTH...SO IT MAY GO BY DRY. AFTER A NEAR NORMAL START TO TEMPS ON TUESDAY WITH HIGHS AROUND 40...WE WILL SEE MUCH COOLER AIR ARRIVE BEHIND THE MID WEEK SYSTEM. HIGHS IN THE UPPER 20S TO AROUND 30 ARE EXPECTED WED AND THU. TEMPS SHOULD BE BRIEFLY WARMER FRIDAY AHEAD OF THE CLIPPER...THEN COOLER AGAIN FOR SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1159 PM EST SAT MAR 8 2014 FOG/STRATUS FORMATION IS A SMALL CONCERN FOR THE LATE NIGHT/EARLY MORNING PERIOD BUT CONFIDENCE REMAINS LOW AND HAVE KEPT THIS THREAT OUT OF THE TAFS. GUIDANCE SHOWS NORTH WINDS OF 10-15 KNOTS JUST ABOVE THE SFC WHICH SHOULD MITIGATE THE THREAT. VFR CONDITIONS ARE LIKELY ON SUNDAY WITH CLOUD BASES AOA 12K FEET. SOUTHWEST WINDS WILL INCREASE AND BECOME RATHER STRONG/GUSTY DURING THE AFTERNOON WITH GUSTS TO 30KTS POSSIBLE ESPECIALLY AT KMKG. THE GUSTINESS WILL DIMINISH AFTER 00Z WITH PERHAPS THE EXCEPTION OF MKG. && .HYDROLOGY... ISSUED AT 230 PM EST SAT MAR 8 2014 NO MAJOR PRECIPITATION SYSTEMS SEEN THROUGH THE FORECAST PERIOD. A MODERATING TREND IN THE TEMPERATURES IS PREDICTED FOR MONDAY INTO TUESDAY. THIS WILL LEAD TO GRADUAL MELTING. TEMPERATURES DO COOL DOWN FOR THE MIDDLE PART OF THE WEEK WHICH WILL SLOWLY DOWN OR STOP ANY MELTING. TEMPERATURES THEN TRY TO MODERATE FOR THE END OF THE WEEK. AS A RESULT...THE SNOWPACK WILL ONLY SLOWLY RELEASE SOME OF ITS WATER THROUGH THE PERIOD. WITH LIMITED RUNOFF WATER LEVELS SHOULD STAY FAIRLY STABLE THIS WEEK. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...MJS SHORT TERM...MJS LONG TERM...JK AVIATION...MEADE HYDROLOGY...MJS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1244 PM CDT SUN MAR 9 2014 .UPDATE... ISSUED AT 1244 PM CDT SUN MAR 9 2014 CURRENT RED FLAG WARNING IS IN GOOD SHAPE WITH NO CHANGES NEEDED AT THIS TIME. MESONET DATA FROM WESTERN AND NORTH CENTRAL NEBRASKA REVEAL NUMEROUS NEDOT...NWS...AND RAWS SITES REACHING RED FLAG WIND CRITERIA AT THIS HOUR. THE LISCO...LEWELLEN AND COMSTOCK SENSORS HAVE ALREADY REACHED RFW RH CRITERIA. DEEP BL MIXING IS IN FULL FORCE AND WILL CONTINUE AS WESTERLY WINDS MIX DOWN DRIER/WARMER AIR ALOFT TO THE SURFACE...WIDESPREAD HIGHS IN THE UPPER 60S TO LOWER 70S ARE STILL ANTICIPATED. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 417 AM CDT SUN MAR 9 2014 THE BANK OF CIRRUS ACROSS THE NRN PLAINS WILL CONTINUE ACROSS THE FCST AREA TODAY AND TONIGHT BUT THE ANTICYCLONIC FLOW WILL TEND TO DISSIPATE THE CLOUDS AS THE DROP SOUTH INTO SRN NEB. THE BEST GUESS ON TEMPS TODAY IS UPPER 60S TO MID 70S. H800MB TEMPS RISE TO 10C WHICH SUPPORTS UPPER 60S. WARMER AIR RESIDES AT 700MB WHICH COULD PUSH TEMPS HIGHER. MR. DEEP MIXING MODEL...THE RAP...SHOWS MIXING HEIGHTS REACHING TO AROUND 750 MB FOR HIGHS IN THE MID 70S AND THIS IS IN LINE WITH THE HRRR MODEL WHICH SHOWS MID 70S ALSO. THESE ARE THE WARMEST MODELS. GIVEN THAT KLBF IS AT 39F AT 330AM CDT WITH LIGHT WEST WINDS...THIS FORECAST APPEARS TO BE ON TRACK. LOW PRESSURE ACROSS MANITOBA WILL MOVE EAST IN THE ONTARIO WITH WEST AND SOUTHWEST WINDS AROUND 10 TO 20 MPH THIS AFTERNOON . A SECOND LOW PRESSURE SYSTEM WILL DROP THROUGH SASKATCHEWAN LATE THIS AFTERNOON AND TONIGHT SETTING UP NORTHWEST WINDS...STILL LIGHT THOUGH. LOWS TONIGHT SHOULD FALL TO JUST THE 30S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 417 AM CDT SUN MAR 9 2014 FORECAST CONCERNS ARE HIGH TEMPERATURES FOR MONDAY...THEN WITH PRECIPITATION CHANCES MONDAY NIGHT AND TUESDAY. THE ELONGATED UPPER LEVEL LOW CURRENTLY SITTING FROM NORTHWEST MEXICO INTO CENTRAL OKLAHOMA WILL SEE LITTLE MOVEMENT INTO MONDAY. LOOKING FURTHER NORTH...THE SHORTWAVE TROUGH NOW OFF THE WEST COAST WILL PUSH ON LAND AND INTO THE INTER-MOUNTAIN WEST ON MONDAY. BETWEEN THESE TWO SYSTEMS RIDGING ALOFT WILL CONTINUE TO HAVE INFLUENCE OVER THE CENTRAL PLAINS. WARM AIR ADVECTION WILL BE ONGOING THROUGH THE DAY MONDAY AS THE SHORTWAVE PROGRESSES EAST...WITH LEE-SIDE CYCLOGENESIS DEVELOPING OVER WYOMING THROUGH THE DAY. THE NAM IS THE WARMER SOLUTION...WITH 850MB TEMPERATURES AT 13C TO 18C BY 00Z TUESDAY ACROSS MUCH OF THE FORECAST AREA. OTHER SOLUTIONS ARE SLIGHTLY COOLER...YET STILL ANOMALOUSLY WARM. CHECKING STANDARDIZED ANOMALIES...TEMPERATURES ON MONDAY WERE GENERALLY AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. MODEL SOUNDINGS SHOW MIXING POTENTIAL TO AROUND 800MB...AND ALTHOUGH THE MODELS HAVE BEEN ROUTINELY TOO LOW WITH MIXING HEIGHTS LATELY THERE ARE A FEW FACTORS THAT COULD KEEP THE BOUNDARY LAYER FROM SEEING DEEP MIXING TO 700MB OR SO. THESE FACTORS ARE FIRST...A SURFACE TROUGH MOVING ACROSS THE AREA TO KEEP WINDS LIGHT AND NOT HELP WITH MIXING...AND SECOND THINKING THERE MIGHT BE SCATTERED TO BROKEN HIGH CLOUDS MOVING INTO THE AREA AHEAD OF THE SYSTEM WHICH COULD LIMIT THE SURFACE WARMING SLIGHTLY. THAT BEING SAID...STILL THINKING HIGHS IN THE 60S AND LOW 70S LOOKS GOOD. THE SHORTWAVE TROUGH WILL PROGRESS EAST MONDAY NIGHT AND TUESDAY WITH THE COLD FRONT MOVING SOUTHEAST AND ACROSS THE FORECAST AREA BY TUESDAY MORNING. THE STRONGEST LIFT WITH THE SYSTEM STAYS OVER SOUTH DAKOTA MONDAY EVENING WITH THE UPPER LEVEL JET STREAK FROM WYOMING INTO WESTERN SOUTH DAKOTA...BUT THIS SIGNAL SINKS SOUTH OVERNIGHT AND THROUGH THE DAY TUESDAY. LOOKING AT MOISTURE IN SOUNDINGS AND CROSS SECTIONS...MOST AREAS WILL SEE ABOUT 6 HOURS OF POTENTIAL FOR PRECIPITATION AND AS THE COLUMN DOES NOT SATURATE ACROSS THE NORTHWEST PART OF THE FORECAST AREA UNTIL NEAR MIDNIGHT BACKED OFF ON PRECIPITATION CHANCES FOR MOST LOCATIONS UNTIL AFTER MIDNIGHT FOR TUESDAY MORNING. THE LARGE SCALE LIFT DOES LOOK TO WANE THROUGH THE DAY TUESDAY AS THE UPPER LEVEL JET WEAKENS AND THIS SIGNAL IS BEING SHOWN BY THE NAM...WITH THE AREA OF PRECIPITATION DIMINISHING AS IT MOVES SOUTH. EVEN WITH THIS SIGNAL IN THE QPF FIELDS...SOUNDINGS SHOW MOST AREAS SEEING AT LEAST A FEW HOURS ON TUESDAY MORNING WITH PRECIPITATION CHANCES STAYING SIMILAR TO THE PRIOR FORECAST. MAY HAVE PRECIPITATION CHANCES LINGERING A BIT LONG INTO THE DAY TUESDAY...ESPECIALLY OVER NORTHWEST NEBRASKA...BUT KEPT LOW END CHANCES FOR THIS FORECAST CYCLE TO ACCOUNT FOR SOME TIMING DIFFERENCES IN MODEL SOLUTIONS AND WILL RE-EVALUATE ON UPCOMING SHIFTS. IN TERMS OF PRECIPITATION TYPE...THE COLDER TEMPERATURES WILL LAG BEHIND THE FRONT SO IT WILL BEGIN AS RAIN THEN AS THE COLUMN COOLS AND THE WET BULB STAYS BELOW ZERO THROUGH ALL BUT THE LOWEST LAYER COULD SEE A MIX OF RAIN AND SNOW...WITH SNOW INTO THE EVENING. ANY ACCUMULATIONS OF SNOW WILL BE LIGHT...IF IT DOES EVEN ACCUMULATE DUE TO THE WARM GROUND TEMPERATURES. FOR THE REMAINDER OF THE WEEK...THE LARGE SCALE FLOW WILL BE FAIRLY STAGNANT...WITH A TROUGH OVER THE EAST PART OF THE COUNTRY AND A BROAD RIDGE ACROSS THE WESTERN HALF. THIS WILL PUT THE LOCAL AREA UNDER THE INFLUENCE OF NORTHWEST FLOW INTO NEXT WEEKEND. HOWEVER...ANY SIGNIFICANT COLDER AIR WILL STAY NORTH AND EAST OF THE FORECAST AREA SO TEMPERATURES ARE EXPECTED TO BE CLOSE TO NORMAL FOR MUCH OF THE EXTENDED PORTION OF THE FORECAST. LOOKING AT PRECIPITATION CHANCES...THERE WILL BE A SHORTWAVE TROUGH PUSHING THROUGH THE NORTHWEST FLOW ON THURSDAY INTO FRIDAY...BUT THE PRIMARY ENERGY WILL BE ACROSS THE DAKOTAS AND MINNESOTA SO DRY CONDITIONS ARE LIKELY WITH THAT PARTICULAR SYSTEM. THEN LOOKING INTO SATURDAY AND SATURDAY NIGHT...THERE IS DECENT AGREEMENT BETWEEN THE LONG TERM MODELS THAT THE UPPER LEVEL FLOW WILL AMPLIFY...ALLOWING A SHORTWAVE TROUGH TO DIG INTO THE CENTRAL PLAINS...BRINGING THE NEXT CHANCES FOR PRECIPITATION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1232 PM CDT SUN MAR 9 2014 VFR EXPECTED TODAY AND TONIGHT FOR ALL WESTERN AND NORTH CENTRAL NEBRASKA TERMINALS. WESTERLY WINDS WILL BE ON THE GUSTY SIDE THIS AFTERNOON...ESPECIALLY AT OPEN TERMINALS SUCH AS KTIF...KVTN AND KBBW WHERE GUST POTENTIAL TO 24KTS IS ANTICIPATED. OTHERWISE...THE WINDS WILL WEAKEN THIS EVENING AS THE ATMOSPHERE DECOUPLES...LEAVING A LIGHT WEST DRAINAGE WIND OF 8KTS OR LESS FOR MOST TERMINALS. && .FIRE WEATHER... ISSUED AT 417 AM CDT SUN MAR 9 2014 DEEP VERTICAL MIXING IS EXPECTED TODAY GIVEN THE MIXING TO 725 MB THE PREVIOUS DAY PER KLBF UA SOUNDING. THIS MIGHT SUPPORT THE LOWER DEW POINTS SHOWN IN THE GEM REG AND ECM WHICH PUSH RH TO 15 TO 20 PERCENT THIS AFTERNOON...FOR ABOUT 1 HOUR. THE DEEP VERTICAL MIXING IS OF LITTLE AVAIL FOR WIND SPEEDS AS THEY FLATTEN OUT TO 15 KT AT 750 MB AND HIGHER. THE GEM AND ECM DO SHOW A BANK OF STRONGER WINDS DEVELOPING AT THE 500M AGL LEVEL THIS AFTERNOON IN THE PANHANDLE WHICH COULD MOVE THROUGH THE FCST AREA...IF...THE ASSOCIATED SFC TROF ADVANCES THROUGH THE FCST AREA AS SHOWN BY THE RAP13 MODEL. THE MODEL CONSENSUS KEEPS THE TROF ALONG HIGHWAY 83 THIS AFTERNOON WHICH PRODUCES A BANK OF SOUTHWEST WINDS EAST OF 83 AND THEN WEST WINDS WEST OF 83. GIVEN THE UNCERTAINTIES OF THE SHARPNESS OF THE TROF...TIMING AND THE WINDS SHOWN IN THE GEM AND THE ECM THE FIRE WEATHER WATCH CAN BE CONVERTED TO A WARNING IN MANY AREAS BUT THIS IS A VERY LOW END WARNING WHICH MIGHT NOT VERIFY GIVEN THE WETNESS OF THE GROUND AND THE PROPENSITY OF THE SUN TO TRANSPORATE MOISTURE TO THE AIR. WINDS GUST TO JUST 25 MPH AND THEY ARE EXPECTED TO BE FAIRLY SPORADIC. THE RAP AND HRRR WERE THE BASIS FOR THE WIND GUST FORECAST WHICH SHOWS THE STRONGEST GUSTS ACROSS THE PLATTE VALLEYS. && .LBF WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ204-206-209. && $$ UPDATE...JACOBS SHORT TERM...CDC LONG TERM...BROOKS AVIATION...JACOBS FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1232 PM CDT SUN MAR 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 417 AM CDT SUN MAR 9 2014 THE BANK OF CIRRUS ACROSS THE NRN PLAINS WILL CONTINUE ACROSS THE FCST AREA TODAY AND TONIGHT BUT THE ANTICYCLONIC FLOW WILL TEND TO DISSIPATE THE CLOUDS AS THE DROP SOUTH INTO SRN NEB. THE BEST GUESS ON TEMPS TODAY IS UPPER 60S TO MID 70S. H800MB TEMPS RISE TO 10C WHICH SUPPORTS UPPER 60S. WARMER AIR RESIDES AT 700MB WHICH COULD PUSH TEMPS HIGHER. MR. DEEP MIXING MODEL...THE RAP...SHOWS MIXING HEIGHTS REACHING TO AROUND 750 MB FOR HIGHS IN THE MID 70S AND THIS IS IN LINE WITH THE HRRR MODEL WHICH SHOWS MID 70S ALSO. THESE ARE THE WARMEST MODELS. GIVEN THAT KLBF IS AT 39F AT 330AM CDT WITH LIGHT WEST WINDS...THIS FORECAST APPEARS TO BE ON TRACK. LOW PRESSURE ACROSS MANITOBA WILL MOVE EAST IN THE ONTARIO WITH WEST AND SOUTHWEST WINDS AROUND 10 TO 20 MPH THIS AFTERNOON . A SECOND LOW PRESSURE SYSTEM WILL DROP THROUGH SASKATCHEWAN LATE THIS AFTERNOON AND TONIGHT SETTING UP NORTHWEST WINDS...STILL LIGHT THOUGH. LOWS TONIGHT SHOULD FALL TO JUST THE 30S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 417 AM CDT SUN MAR 9 2014 FORECAST CONCERNS ARE HIGH TEMPERATURES FOR MONDAY...THEN WITH PRECIPITATION CHANCES MONDAY NIGHT AND TUESDAY. THE ELONGATED UPPER LEVEL LOW CURRENTLY SITTING FROM NORTHWEST MEXICO INTO CENTRAL OKLAHOMA WILL SEE LITTLE MOVEMENT INTO MONDAY. LOOKING FURTHER NORTH...THE SHORTWAVE TROUGH NOW OFF THE WEST COAST WILL PUSH ON LAND AND INTO THE INTER-MOUNTAIN WEST ON MONDAY. BETWEEN THESE TWO SYSTEMS RIDGING ALOFT WILL CONTINUE TO HAVE INFLUENCE OVER THE CENTRAL PLAINS. WARM AIR ADVECTION WILL BE ONGOING THROUGH THE DAY MONDAY AS THE SHORTWAVE PROGRESSES EAST...WITH LEE-SIDE CYCLOGENESIS DEVELOPING OVER WYOMING THROUGH THE DAY. THE NAM IS THE WARMER SOLUTION...WITH 850MB TEMPERATURES AT 13C TO 18C BY 00Z TUESDAY ACROSS MUCH OF THE FORECAST AREA. OTHER SOLUTIONS ARE SLIGHTLY COOLER...YET STILL ANOMALOUSLY WARM. CHECKING STANDARDIZED ANOMALIES...TEMPERATURES ON MONDAY WERE GENERALLY AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. MODEL SOUNDINGS SHOW MIXING POTENTIAL TO AROUND 800MB...AND ALTHOUGH THE MODELS HAVE BEEN ROUTINELY TOO LOW WITH MIXING HEIGHTS LATELY THERE ARE A FEW FACTORS THAT COULD KEEP THE BOUNDARY LAYER FROM SEEING DEEP MIXING TO 700MB OR SO. THESE FACTORS ARE FIRST...A SURFACE TROUGH MOVING ACROSS THE AREA TO KEEP WINDS LIGHT AND NOT HELP WITH MIXING...AND SECOND THINKING THERE MIGHT BE SCATTERED TO BROKEN HIGH CLOUDS MOVING INTO THE AREA AHEAD OF THE SYSTEM WHICH COULD LIMIT THE SURFACE WARMING SLIGHTLY. THAT BEING SAID...STILL THINKING HIGHS IN THE 60S AND LOW 70S LOOKS GOOD. THE SHORTWAVE TROUGH WILL PROGRESS EAST MONDAY NIGHT AND TUESDAY WITH THE COLD FRONT MOVING SOUTHEAST AND ACROSS THE FORECAST AREA BY TUESDAY MORNING. THE STRONGEST LIFT WITH THE SYSTEM STAYS OVER SOUTH DAKOTA MONDAY EVENING WITH THE UPPER LEVEL JET STREAK FROM WYOMING INTO WESTERN SOUTH DAKOTA...BUT THIS SIGNAL SINKS SOUTH OVERNIGHT AND THROUGH THE DAY TUESDAY. LOOKING AT MOISTURE IN SOUNDINGS AND CROSS SECTIONS...MOST AREAS WILL SEE ABOUT 6 HOURS OF POTENTIAL FOR PRECIPITATION AND AS THE COLUMN DOES NOT SATURATE ACROSS THE NORTHWEST PART OF THE FORECAST AREA UNTIL NEAR MIDNIGHT BACKED OFF ON PRECIPITATION CHANCES FOR MOST LOCATIONS UNTIL AFTER MIDNIGHT FOR TUESDAY MORNING. THE LARGE SCALE LIFT DOES LOOK TO WANE THROUGH THE DAY TUESDAY AS THE UPPER LEVEL JET WEAKENS AND THIS SIGNAL IS BEING SHOWN BY THE NAM...WITH THE AREA OF PRECIPITATION DIMINISHING AS IT MOVES SOUTH. EVEN WITH THIS SIGNAL IN THE QPF FIELDS...SOUNDINGS SHOW MOST AREAS SEEING AT LEAST A FEW HOURS ON TUESDAY MORNING WITH PRECIPITATION CHANCES STAYING SIMILAR TO THE PRIOR FORECAST. MAY HAVE PRECIPITATION CHANCES LINGERING A BIT LONG INTO THE DAY TUESDAY...ESPECIALLY OVER NORTHWEST NEBRASKA...BUT KEPT LOW END CHANCES FOR THIS FORECAST CYCLE TO ACCOUNT FOR SOME TIMING DIFFERENCES IN MODEL SOLUTIONS AND WILL RE-EVALUATE ON UPCOMING SHIFTS. IN TERMS OF PRECIPITATION TYPE...THE COLDER TEMPERATURES WILL LAG BEHIND THE FRONT SO IT WILL BEGIN AS RAIN THEN AS THE COLUMN COOLS AND THE WET BULB STAYS BELOW ZERO THROUGH ALL BUT THE LOWEST LAYER COULD SEE A MIX OF RAIN AND SNOW...WITH SNOW INTO THE EVENING. ANY ACCUMULATIONS OF SNOW WILL BE LIGHT...IF IT DOES EVEN ACCUMULATE DUE TO THE WARM GROUND TEMPERATURES. FOR THE REMAINDER OF THE WEEK...THE LARGE SCALE FLOW WILL BE FAIRLY STAGNANT...WITH A TROUGH OVER THE EAST PART OF THE COUNTRY AND A BROAD RIDGE ACROSS THE WESTERN HALF. THIS WILL PUT THE LOCAL AREA UNDER THE INFLUENCE OF NORTHWEST FLOW INTO NEXT WEEKEND. HOWEVER...ANY SIGNIFICANT COLDER AIR WILL STAY NORTH AND EAST OF THE FORECAST AREA SO TEMPERATURES ARE EXPECTED TO BE CLOSE TO NORMAL FOR MUCH OF THE EXTENDED PORTION OF THE FORECAST. LOOKING AT PRECIPITATION CHANCES...THERE WILL BE A SHORTWAVE TROUGH PUSHING THROUGH THE NORTHWEST FLOW ON THURSDAY INTO FRIDAY...BUT THE PRIMARY ENERGY WILL BE ACROSS THE DAKOTAS AND MINNESOTA SO DRY CONDITIONS ARE LIKELY WITH THAT PARTICULAR SYSTEM. THEN LOOKING INTO SATURDAY AND SATURDAY NIGHT...THERE IS DECENT AGREEMENT BETWEEN THE LONG TERM MODELS THAT THE UPPER LEVEL FLOW WILL AMPLIFY...ALLOWING A SHORTWAVE TROUGH TO DIG INTO THE CENTRAL PLAINS...BRINGING THE NEXT CHANCES FOR PRECIPITATION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1232 PM CDT SUN MAR 9 2014 VFR EXPECTED TODAY AND TONIGHT FOR ALL WESTERN AND NORTH CENTRAL NEBRASKA TERMINALS. WESTERLY WINDS WILL BE ON THE GUSTY SIDE THIS AFTERNOON...ESPECIALLY AT OPEN TERMINALS SUCH AS KTIF...KVTN AND KBBW WHERE GUST POTENTIAL TO 24KTS IS ANTICIPATED. OTHERWISE...THE WINDS WILL WEAKEN THIS EVENING AS THE ATMOSPHERE DECOUPLES...LEAVING A LIGHT WEST DRAINAGE WIND OF 8KTS OR LESS FOR MOST TERMINALS. && .FIRE WEATHER... ISSUED AT 417 AM CDT SUN MAR 9 2014 DEEP VERTICAL MIXING IS EXPECTED TODAY GIVEN THE MIXING TO 725 MB THE PREVIOUS DAY PER KLBF UA SOUNDING. THIS MIGHT SUPPORT THE LOWER DEW POINTS SHOWN IN THE GEM REG AND ECM WHICH PUSH RH TO 15 TO 20 PERCENT THIS AFTERNOON...FOR ABOUT 1 HOUR. THE DEEP VERTICAL MIXING IS OF LITTLE AVAIL FOR WIND SPEEDS AS THEY FLATTEN OUT TO 15 KT AT 750 MB AND HIGHER. THE GEM AND ECM DO SHOW A BANK OF STRONGER WINDS DEVELOPING AT THE 500M AGL LEVEL THIS AFTERNOON IN THE PANHANDLE WHICH COULD MOVE THROUGH THE FCST AREA...IF...THE ASSOCIATED SFC TROF ADVANCES THROUGH THE FCST AREA AS SHOWN BY THE RAP13 MODEL. THE MODEL CONSENSUS KEEPS THE TROF ALONG HIGHWAY 83 THIS AFTERNOON WHICH PRODUCES A BANK OF SOUTHWEST WINDS EAST OF 83 AND THEN WEST WINDS WEST OF 83. GIVEN THE UNCERTAINTIES OF THE SHARPNESS OF THE TROF...TIMING AND THE WINDS SHOWN IN THE GEM AND THE ECM THE FIRE WEATHER WATCH CAN BE CONVERTED TO A WARNING IN MANY AREAS BUT THIS IS A VERY LOW END WARNING WHICH MIGHT NOT VERIFY GIVEN THE WETNESS OF THE GROUND AND THE PROPENSITY OF THE SUN TO TRANSPORATE MOISTURE TO THE AIR. WINDS GUST TO JUST 25 MPH AND THEY ARE EXPECTED TO BE FAIRLY SPORADIC. THE RAP AND HRRR WERE THE BASIS FOR THE WIND GUST FORECAST WHICH SHOWS THE STRONGEST GUSTS ACROSS THE PLATTE VALLEYS. && .LBF WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ204-206-209. && $$ SHORT TERM...CDC LONG TERM...BROOKS AVIATION...JACOBS FIRE WEATHER...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
628 AM CDT SUN MAR 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 417 AM CDT SUN MAR 9 2014 THE BANK OF CIRRUS ACROSS THE NRN PLAINS WILL CONTINUE ACROSS THE FCST AREA TODAY AND TONIGHT BUT THE ANTICYCLONIC FLOW WILL TEND TO DISSIPATE THE CLOUDS AS THE DROP SOUTH INTO SRN NEB. THE BEST GUESS ON TEMPS TODAY IS UPPER 60S TO MID 70S. H800MB TEMPS RISE TO 10C WHICH SUPPORTS UPPER 60S. WARMER AIR RESIDES AT 700MB WHICH COULD PUSH TEMPS HIGHER. MR. DEEP MIXING MODEL...THE RAP...SHOWS MIXING HEIGHTS REACHING TO AROUND 750 MB FOR HIGHS IN THE MID 70S AND THIS IS IN LINE WITH THE HRRR MODEL WHICH SHOWS MID 70S ALSO. THESE ARE THE WARMEST MODELS. GIVEN THAT KLBF IS AT 39F AT 330AM CDT WITH LIGHT WEST WINDS...THIS FORECAST APPEARS TO BE ON TRACK. LOW PRESSURE ACROSS MANITOBA WILL MOVE EAST IN THE ONTARIO WITH WEST AND SOUTHWEST WINDS AROUND 10 TO 20 MPH THIS AFTERNOON . A SECOND LOW PRESSURE SYSTEM WILL DROP THROUGH SASKATCHEWAN LATE THIS AFTERNOON AND TONIGHT SETTING UP NORTHWEST WINDS...STILL LIGHT THOUGH. LOWS TONIGHT SHOULD FALL TO JUST THE 30S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 417 AM CDT SUN MAR 9 2014 FORECAST CONCERNS ARE HIGH TEMPERATURES FOR MONDAY...THEN WITH PRECIPITATION CHANCES MONDAY NIGHT AND TUESDAY. THE ELONGATED UPPER LEVEL LOW CURRENTLY SITTING FROM NORTHWEST MEXICO INTO CENTRAL OKLAHOMA WILL SEE LITTLE MOVEMENT INTO MONDAY. LOOKING FURTHER NORTH...THE SHORTWAVE TROUGH NOW OFF THE WEST COAST WILL PUSH ON LAND AND INTO THE INTER-MOUNTAIN WEST ON MONDAY. BETWEEN THESE TWO SYSTEMS RIDGING ALOFT WILL CONTINUE TO HAVE INFLUENCE OVER THE CENTRAL PLAINS. WARM AIR ADVECTION WILL BE ONGOING THROUGH THE DAY MONDAY AS THE SHORTWAVE PROGRESSES EAST...WITH LEE-SIDE CYCLOGENESIS DEVELOPING OVER WYOMING THROUGH THE DAY. THE NAM IS THE WARMER SOLUTION...WITH 850MB TEMPERATURES AT 13C TO 18C BY 00Z TUESDAY ACROSS MUCH OF THE FORECAST AREA. OTHER SOLUTIONS ARE SLIGHTLY COOLER...YET STILL ANOMALOUSLY WARM. CHECKING STANDARDIZED ANOMALIES...TEMPERATURES ON MONDAY WERE GENERALLY AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. MODEL SOUNDINGS SHOW MIXING POTENTIAL TO AROUND 800MB...AND ALTHOUGH THE MODELS HAVE BEEN ROUTINELY TOO LOW WITH MIXING HEIGHTS LATELY THERE ARE A FEW FACTORS THAT COULD KEEP THE BOUNDARY LAYER FROM SEEING DEEP MIXING TO 700MB OR SO. THESE FACTORS ARE FIRST...A SURFACE TROUGH MOVING ACROSS THE AREA TO KEEP WINDS LIGHT AND NOT HELP WITH MIXING...AND SECOND THINKING THERE MIGHT BE SCATTERED TO BROKEN HIGH CLOUDS MOVING INTO THE AREA AHEAD OF THE SYSTEM WHICH COULD LIMIT THE SURFACE WARMING SLIGHTLY. THAT BEING SAID...STILL THINKING HIGHS IN THE 60S AND LOW 70S LOOKS GOOD. THE SHORTWAVE TROUGH WILL PROGRESS EAST MONDAY NIGHT AND TUESDAY WITH THE COLD FRONT MOVING SOUTHEAST AND ACROSS THE FORECAST AREA BY TUESDAY MORNING. THE STRONGEST LIFT WITH THE SYSTEM STAYS OVER SOUTH DAKOTA MONDAY EVENING WITH THE UPPER LEVEL JET STREAK FROM WYOMING INTO WESTERN SOUTH DAKOTA...BUT THIS SIGNAL SINKS SOUTH OVERNIGHT AND THROUGH THE DAY TUESDAY. LOOKING AT MOISTURE IN SOUNDINGS AND CROSS SECTIONS...MOST AREAS WILL SEE ABOUT 6 HOURS OF POTENTIAL FOR PRECIPITATION AND AS THE COLUMN DOES NOT SATURATE ACROSS THE NORTHWEST PART OF THE FORECAST AREA UNTIL NEAR MIDNIGHT BACKED OFF ON PRECIPITATION CHANCES FOR MOST LOCATIONS UNTIL AFTER MIDNIGHT FOR TUESDAY MORNING. THE LARGE SCALE LIFT DOES LOOK TO WANE THROUGH THE DAY TUESDAY AS THE UPPER LEVEL JET WEAKENS AND THIS SIGNAL IS BEING SHOWN BY THE NAM...WITH THE AREA OF PRECIPITATION DIMINISHING AS IT MOVES SOUTH. EVEN WITH THIS SIGNAL IN THE QPF FIELDS...SOUNDINGS SHOW MOST AREAS SEEING AT LEAST A FEW HOURS ON TUESDAY MORNING WITH PRECIPITATION CHANCES STAYING SIMILAR TO THE PRIOR FORECAST. MAY HAVE PRECIPITATION CHANCES LINGERING A BIT LONG INTO THE DAY TUESDAY...ESPECIALLY OVER NORTHWEST NEBRASKA...BUT KEPT LOW END CHANCES FOR THIS FORECAST CYCLE TO ACCOUNT FOR SOME TIMING DIFFERENCES IN MODEL SOLUTIONS AND WILL RE-EVALUATE ON UPCOMING SHIFTS. IN TERMS OF PRECIPITATION TYPE...THE COLDER TEMPERATURES WILL LAG BEHIND THE FRONT SO IT WILL BEGIN AS RAIN THEN AS THE COLUMN COOLS AND THE WET BULB STAYS BELOW ZERO THROUGH ALL BUT THE LOWEST LAYER COULD SEE A MIX OF RAIN AND SNOW...WITH SNOW INTO THE EVENING. ANY ACCUMULATIONS OF SNOW WILL BE LIGHT...IF IT DOES EVEN ACCUMULATE DUE TO THE WARM GROUND TEMPERATURES. FOR THE REMAINDER OF THE WEEK...THE LARGE SCALE FLOW WILL BE FAIRLY STAGNANT...WITH A TROUGH OVER THE EAST PART OF THE COUNTRY AND A BROAD RIDGE ACROSS THE WESTERN HALF. THIS WILL PUT THE LOCAL AREA UNDER THE INFLUENCE OF NORTHWEST FLOW INTO NEXT WEEKEND. HOWEVER...ANY SIGNIFICANT COLDER AIR WILL STAY NORTH AND EAST OF THE FORECAST AREA SO TEMPERATURES ARE EXPECTED TO BE CLOSE TO NORMAL FOR MUCH OF THE EXTENDED PORTION OF THE FORECAST. LOOKING AT PRECIPITATION CHANCES...THERE WILL BE A SHORTWAVE TROUGH PUSHING THROUGH THE NORTHWEST FLOW ON THURSDAY INTO FRIDAY...BUT THE PRIMARY ENERGY WILL BE ACROSS THE DAKOTAS AND MINNESOTA SO DRY CONDITIONS ARE LIKELY WITH THAT PARTICULAR SYSTEM. THEN LOOKING INTO SATURDAY AND SATURDAY NIGHT...THERE IS DECENT AGREEMENT BETWEEN THE LONG TERM MODELS THAT THE UPPER LEVEL FLOW WILL AMPLIFY...ALLOWING A SHORTWAVE TROUGH TO DIG INTO THE CENTRAL PLAINS...BRINGING THE NEXT CHANCES FOR PRECIPITATION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 628 AM CDT SUN MAR 9 2014 VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT. AN UPPER LEVEL DISTURBANCE ACROSS THE PACIFIC NORTHWEST WILL CONTINUE TO PRODUCE HIGH CLOUDINESS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. && .FIRE WEATHER... ISSUED AT 417 AM CDT SUN MAR 9 2014 DEEP VERTICAL MIXING IS EXPECTED TODAY GIVEN THE MIXING TO 725 MB THE PREVIOUS DAY PER KLBF UA SOUNDING. THIS MIGHT SUPPORT THE LOWER DEW POINTS SHOWN IN THE GEM REG AND ECM WHICH PUSH RH TO 15 TO 20 PERCENT THIS AFTERNOON...FOR ABOUT 1 HOUR. THE DEEP VERTICAL MIXING IS OF LITTLE AVAIL FOR WIND SPEEDS AS THEY FLATTEN OUT TO 15 KT AT 750 MB AND HIGHER. THE GEM AND ECM DO SHOW A BANK OF STRONGER WINDS DEVELOPING AT THE 500M AGL LEVEL THIS AFTERNOON IN THE PANHANDLE WHICH COULD MOVE THROUGH THE FCST AREA...IF...THE ASSOCIATED SFC TROF ADVANCES THROUGH THE FCST AREA AS SHOWN BY THE RAP13 MODEL. THE MODEL CONSENSUS KEEPS THE TROF ALONG HIGHWAY 83 THIS AFTERNOON WHICH PRODUCES A BANK OF SOUTHWEST WINDS EAST OF 83 AND THEN WEST WINDS WEST OF 83. GIVEN THE UNCERTAINTIES OF THE SHARPNESS OF THE TROF...TIMING AND THE WINDS SHOWN IN THE GEM AND THE ECM THE FIRE WEATHER WATCH CAN BE CONVERTED TO A WARNING IN MANY AREAS BUT THIS IS A VERY LOW END WARNING WHICH MIGHT NOT VERIFY GIVEN THE WETNESS OF THE GROUND AND THE PROPENSITY OF THE SUN TO TRANSPORATE MOISTURE TO THE AIR. WINDS GUST TO JUST 25 MPH AND THEY ARE EXPECTED TO BE FAIRLY SPORADIC. THE RAP AND HRRR WERE THE BASIS FOR THE WIND GUST FORECAST WHICH SHOWS THE STRONGEST GUSTS ACROSS THE PLATTE VALLEYS. && .LBF WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ204-206-209. && $$ SHORT TERM...CDC LONG TERM...BROOKS AVIATION...CDC FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
418 AM CDT SUN MAR 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 417 AM CDT SUN MAR 9 2014 THE BANK OF CIRRUS ACROSS THE NRN PLAINS WILL CONTINUE ACROSS THE FCST AREA TODAY AND TONIGHT BUT THE ANTICYCLONIC FLOW WILL TEND TO DISSIPATE THE CLOUDS AS THE DROP SOUTH INTO SRN NEB. THE BEST GUESS ON TEMPS TODAY IS UPPER 60S TO MID 70S. H800MB TEMPS RISE TO 10C WHICH SUPPORTS UPPER 60S. WARMER AIR RESIDES AT 700MB WHICH COULD PUSH TEMPS HIGHER. MR. DEEP MIXING MODEL...THE RAP...SHOWS MIXING HEIGHTS REACHING TO AROUND 750 MB FOR HIGHS IN THE MID 70S AND THIS IS IN LINE WITH THE HRRR MODEL WHICH SHOWS MID 70S ALSO. THESE ARE THE WARMEST MODELS. GIVEN THAT KLBF IS AT 39F AT 330AM CDT WITH LIGHT WEST WINDS...THIS FORECAST APPEARS TO BE ON TRACK. LOW PRESSURE ACROSS MANITOBA WILL MOVE EAST IN THE ONTARIO WITH WEST AND SOUTHWEST WINDS AROUND 10 TO 20 MPH THIS AFTERNOON . A SECOND LOW PRESSURE SYSTEM WILL DROP THROUGH SASKATCHEWAN LATE THIS AFTERNOON AND TONIGHT SETTING UP NORTHWEST WINDS...STILL LIGHT THOUGH. LOWS TONIGHT SHOULD FALL TO JUST THE 30S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 417 AM CDT SUN MAR 9 2014 FORECAST CONCERNS ARE HIGH TEMPERATURES FOR MONDAY...THEN WITH PRECIPITATION CHANCES MONDAY NIGHT AND TUESDAY. THE ELONGATED UPPER LEVEL LOW CURRENTLY SITTING FROM NORTHWEST MEXICO INTO CENTRAL OKLAHOMA WILL SEE LITTLE MOVEMENT INTO MONDAY. LOOKING FURTHER NORTH...THE SHORTWAVE TROUGH NOW OFF THE WEST COAST WILL PUSH ON LAND AND INTO THE INTER-MOUNTAIN WEST ON MONDAY. BETWEEN THESE TWO SYSTEMS RIDGING ALOFT WILL CONTINUE TO HAVE INFLUENCE OVER THE CENTRAL PLAINS. WARM AIR ADVECTION WILL BE ONGOING THROUGH THE DAY MONDAY AS THE SHORTWAVE PROGRESSES EAST...WITH LEE-SIDE CYCLOGENESIS DEVELOPING OVER WYOMING THROUGH THE DAY. THE NAM IS THE WARMER SOLUTION...WITH 850MB TEMPERATURES AT 13C TO 18C BY 00Z TUESDAY ACROSS MUCH OF THE FORECAST AREA. OTHER SOLUTIONS ARE SLIGHTLY COOLER...YET STILL ANOMALOUSLY WARM. CHECKING STANDARDIZED ANOMALIES...TEMPERATURES ON MONDAY WERE GENERALLY AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. MODEL SOUNDINGS SHOW MIXING POTENTIAL TO AROUND 800MB...AND ALTHOUGH THE MODELS HAVE BEEN ROUTINELY TOO LOW WITH MIXING HEIGHTS LATELY THERE ARE A FEW FACTORS THAT COULD KEEP THE BOUNDARY LAYER FROM SEEING DEEP MIXING TO 700MB OR SO. THESE FACTORS ARE FIRST...A SURFACE TROUGH MOVING ACROSS THE AREA TO KEEP WINDS LIGHT AND NOT HELP WITH MIXING...AND SECOND THINKING THERE MIGHT BE SCATTERED TO BROKEN HIGH CLOUDS MOVING INTO THE AREA AHEAD OF THE SYSTEM WHICH COULD LIMIT THE SURFACE WARMING SLIGHTLY. THAT BEING SAID...STILL THINKING HIGHS IN THE 60S AND LOW 70S LOOKS GOOD. THE SHORTWAVE TROUGH WILL PROGRESS EAST MONDAY NIGHT AND TUESDAY WITH THE COLD FRONT MOVING SOUTHEAST AND ACROSS THE FORECAST AREA BY TUESDAY MORNING. THE STRONGEST LIFT WITH THE SYSTEM STAYS OVER SOUTH DAKOTA MONDAY EVENING WITH THE UPPER LEVEL JET STREAK FROM WYOMING INTO WESTERN SOUTH DAKOTA...BUT THIS SIGNAL SINKS SOUTH OVERNIGHT AND THROUGH THE DAY TUESDAY. LOOKING AT MOISTURE IN SOUNDINGS AND CROSS SECTIONS...MOST AREAS WILL SEE ABOUT 6 HOURS OF POTENTIAL FOR PRECIPITATION AND AS THE COLUMN DOES NOT SATURATE ACROSS THE NORTHWEST PART OF THE FORECAST AREA UNTIL NEAR MIDNIGHT BACKED OFF ON PRECIPITATION CHANCES FOR MOST LOCATIONS UNTIL AFTER MIDNIGHT FOR TUESDAY MORNING. THE LARGE SCALE LIFT DOES LOOK TO WANE THROUGH THE DAY TUESDAY AS THE UPPER LEVEL JET WEAKENS AND THIS SIGNAL IS BEING SHOWN BY THE NAM...WITH THE AREA OF PRECIPITATION DIMINISHING AS IT MOVES SOUTH. EVEN WITH THIS SIGNAL IN THE QPF FIELDS...SOUNDINGS SHOW MOST AREAS SEEING AT LEAST A FEW HOURS ON TUESDAY MORNING WITH PRECIPITATION CHANCES STAYING SIMILAR TO THE PRIOR FORECAST. MAY HAVE PRECIPITATION CHANCES LINGERING A BIT LONG INTO THE DAY TUESDAY...ESPECIALLY OVER NORTHWEST NEBRASKA...BUT KEPT LOW END CHANCES FOR THIS FORECAST CYCLE TO ACCOUNT FOR SOME TIMING DIFFERENCES IN MODEL SOLUTIONS AND WILL RE-EVALUATE ON UPCOMING SHIFTS. IN TERMS OF PRECIPITATION TYPE...THE COLDER TEMPERATURES WILL LAG BEHIND THE FRONT SO IT WILL BEGIN AS RAIN THEN AS THE COLUMN COOLS AND THE WET BULB STAYS BELOW ZERO THROUGH ALL BUT THE LOWEST LAYER COULD SEE A MIX OF RAIN AND SNOW...WITH SNOW INTO THE EVENING. ANY ACCUMULATIONS OF SNOW WILL BE LIGHT...IF IT DOES EVEN ACCUMULATE DUE TO THE WARM GROUND TEMPERATURES. FOR THE REMAINDER OF THE WEEK...THE LARGE SCALE FLOW WILL BE FAIRLY STAGNANT...WITH A TROUGH OVER THE EAST PART OF THE COUNTRY AND A BROAD RIDGE ACROSS THE WESTERN HALF. THIS WILL PUT THE LOCAL AREA UNDER THE INFLUENCE OF NORTHWEST FLOW INTO NEXT WEEKEND. HOWEVER...ANY SIGNIFICANT COLDER AIR WILL STAY NORTH AND EAST OF THE FORECAST AREA SO TEMPERATURES ARE EXPECTED TO BE CLOSE TO NORMAL FOR MUCH OF THE EXTENDED PORTION OF THE FORECAST. LOOKING AT PRECIPITATION CHANCES...THERE WILL BE A SHORTWAVE TROUGH PUSHING THROUGH THE NORTHWEST FLOW ON THURSDAY INTO FRIDAY...BUT THE PRIMARY ENERGY WILL BE ACROSS THE DAKOTAS AND MINNESOTA SO DRY CONDITIONS ARE LIKELY WITH THAT PARTICULAR SYSTEM. THEN LOOKING INTO SATURDAY AND SATURDAY NIGHT...THERE IS DECENT AGREEMENT BETWEEN THE LONG TERM MODELS THAT THE UPPER LEVEL FLOW WILL AMPLIFY...ALLOWING A SHORTWAVE TROUGH TO DIG INTO THE CENTRAL PLAINS...BRINGING THE NEXT CHANCES FOR PRECIPITATION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1134 PM CST SAT MAR 8 2014 SCATTERED HIGH CLOUDINESS OVERNIGHT WILL BE REPLACED BY BROKEN HIGH CLOUDINESS BY SUNDAY MORNING. LIGHT SOUTHWEST WINDS OVERNIGHT TO BECOME 26014G23KT AFTER 15Z. WEST WINDS WILL DECOUPLE BY 00Z/10TH. && .FIRE WEATHER... ISSUED AT 417 AM CDT SUN MAR 9 2014 DEEP VERTICAL MIXING IS EXPECTED TODAY GIVEN THE MIXING TO 725 MB THE PREVIOUS DAY PER KLBF UA SOUNDING. THIS MIGHT SUPPORT THE LOWER DEW POINTS SHOWN IN THE GEM REG AND ECM WHICH PUSH RH TO 15 TO 20 PERCENT THIS AFTERNOON...FOR ABOUT 1 HOUR. THE DEEP VERTICAL MIXING IS OF LITTLE AVAIL FOR WIND SPEEDS AS THEY FLATTEN OUT TO 15 KT AT 750 MB AND HIGHER. THE GEM AND ECM DO SHOW A BANK OF STRONGER WINDS DEVELOPING AT THE 500M AGL LEVEL THIS AFTERNOON IN THE PANHANDLE WHICH COULD MOVE THROUGH THE FCST AREA...IF...THE ASSOCIATED SFC TROF ADVANCES THROUGH THE FCST AREA AS SHOWN BY THE RAP13 MODEL. THE MODEL CONSENSUS KEEPS THE TROF ALONG HIGHWAY 83 THIS AFTERNOON WHICH PRODUCES A BANK OF SOUTHWEST WINDS EAST OF 83 AND THEN WEST WINDS WEST OF 83. GIVEN THE UNCERTAINTIES OF THE SHARPNESS OF THE TROF...TIMING AND THE WINDS SHOWN IN THE GEM AND THE ECM THE FIRE WEATHER WATCH CAN BE CONVERTED TO A WARNING IN MANY AREAS BUT THIS IS A VERY LOW END WARNING WHICH MIGHT NOT VERIFY GIVEN THE WETNESS OF THE GROUND AND THE PROPENSITY OF THE SUN TO TRANSPORATE MOISTURE TO THE AIR. WINDS GUST TO JUST 25 MPH AND THEY ARE EXPECTED TO BE FAIRLY SPORADIC. THE RAP AND HRRR WERE THE BASIS FOR THE WIND GUST FORECAST WHICH SHOWS THE STRONGEST GUSTS ACROSS THE PLATTE VALLEYS. && .LBF WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ204-206-209. && $$ SHORT TERM...CDC LONG TERM...BROOKS AVIATION...ROBERG FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1126 PM CST SAT MAR 8 2014 .UPDATE...FOR 06Z AVIATION. && .AVIATION...06Z TAF DISCUSSION. CIGS HAVE BEEN SLOW TO DROP BEHIND THE PASSING FRONTAL SYSTEM... BUT THEY ARE ON THE WAY. STILL EXPECTED TO BE SHORT LIVED...ALL TERMINALS SHOULD EXPERIENCE IFR CONDITIONS PRIOR TO SUNRISE AND THEN IMPROVE BACK TO VFR BY 17Z SUNDAY. WINDS HAVE ALREADY SHIFTED AROUND TO THE NORTH OR NORTHWEST AND WILL REMAIN LIGHT. UNGER && .PREV DISCUSSION... /ISSUED 838 PM CST SAT MAR 8 2014/ UPDATE... ONLY MINOR CHANGES MADE TO ONGOING FORECAST. LATEST SURFACE OBS SHOW COLD FRONT PROGRESSING THROUGH THE CWA AND CURRENTLY NEAR A HOHENWALD TO COOKEVILLE LINE. RADAR SHOWS A FEW LIGHT SHOWERS SPREADING INTO WESTERN ZONES...BUT HRRR INDICATES THIS ACTIVITY WILL STRUGGLE TO MOVE EASTWARD WITH ONLY ISOLATED ACTIVITY OVERNIGHT MAINLY WEST OF I-65. WILL KEEP SLIGHT CHANCE POPS GOING FOR ALL AREAS BUT SHOULD NOT AMOUNT TO MUCH. OTHERWISE...ADJUSTED SKY COVER AND TEMPS BASED ON OBS WITH REST OF FORECAST GENERALLY ON TRACK. SHAMBURGER && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 27
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1213 PM CDT SUN MAR 9 2014 .DISCUSSION... SEE 18Z AVIATION DISCUSSION. && .AVIATION... CIGS SLOW TO LIFT THIS MORNING BUT STILL FEEL CIGS WILL BECOME MVFR BY MID AFTERNOON AND VFR BY EVENING BEFORE FALLING BACK TO MVFR/LIFR OVERNIGHT. NAM AND GFS DIFFER SIGNIFICANTLY WITH REGARD TO CIG HTS OVERNIGHT. RAP TENDS TO SUPPORT THE GFS SO LEANED A BIT IN THE DIRECTION. WINDS WILL VEER TO THE NE OVERNIGHT AND SE ON MONDAY MORNING. 43 && .PREV DISCUSSION... /ISSUED 1051 AM CDT SUN MAR 9 2014/ UPDATE... LARGE OFFSHORE LIGHT RAIN SHIELD SLOWLY PULLING EAST THIS MORNING ..LIGHT RAIN ENDING ALONG THE COAST THIS HOUR. AFTER THIS EARLY MORNING MUCK OF LOW CEILINGS AND FOG CLEARS OUT WE WILL BE LEFT WITH AN OVERCAST...COOL AND DAMP DAY. CONVECTION FIRING EAST OF THE WESTERN GULF SURFACE TROUGH AXIS. THIS TROF WILL KEEP THE MAJORITY OF THE PRECIPITATION ACROSS THE WATERS THROUGH MONDAY MORNING...OCCASIONAL LIGHT SHOWERS FROM THE COASTAL BEND UP INTO THE MATAGORDA BAY REGION. ENSEMBLE SLOWING THE EASTERN PROGRESSION OF THE UPPER LOW OVER THE SONARA/CHIHUAHUA PROVINCES AND TAKING IT SOUTH OF SE`ERN TX EARLY TUESDAY THAT WILL KEEP THE HIGHEST POPS/QPF OVER THE COASTAL REGIONS/GULF LATE MONDAY THROUGH TUESDAY MORNING. SUBSEQUENT WEEK DAY WARMTH WITH CLEARING SKIES GOING INTO MID-WEEK. 31 PREV DISCUSSION... /ISSUED 451 AM CDT SUN MAR 9 2014/ DISCUSSION... AREA RADAR SHOW SOME RAIN STRETCHING MAINLY NORTH OF I-10 WITH A BROAD AREA OF RAIN BACK TOWARDS VICTORIA. SFC COLD FRONT HAS JUST PUSHED OFF THE COAST WITH TEMPS IN THE 40S/50S BEHIND IT. UPPER AIR ANALYSIS HAS 850MB FRONT FROM W OF DFW TO JUST NORTH OF JCT. SEEMS THAT ISENTROPIC LIFT OVER THE FRONT HAS LED TO RAIN ACTIVITY OVER SE TX WHICH SEEMS TO BE DIMINISHING AS 925-850MB FLOW WEAKENS. ANALYSIS AT 500MB SHOWS BROAD TROUGHING FROM THE PLAINS BACK TO THE DESERT SW. WEAK UPPER LOW CONTINUES TO SHEAR OUT OVER THE S PLAINS WHILE SECOND LOW CONTINUES TO CLOSE OFF OVER NORTHERN MEXICO. WATER VAPOR IMAGERY DOES SHOW SOME COLDER CLOUD TOPS ASSOCIATED WITH LIFT FROM A WEAK SHORTWAVE TROUGH COMING ACROSS S TX. THIS SEEMS TO BE FORCING MODERATE RAIN BACK TO THE SW NEAR VCT. BASED ON THESE TRENDS DECIDED TO GO WITH HIGHER POPS ALONG THE COAST MAINLY 60/70 PERCENT. 06Z RUN OF HRRR SEEMS TO SUPPORT THIS IDEA ALONG WITH DECREASING RAIN CHANCES FOR THE AFTERNOON. DO NOT THINK HEAVY RAINFALL WILL BE MUCH OF AN ISSUE. LOOKS LIKE 1.5 INCH PRECIP WATER VALUES WILL STAY OVER THE GULF. STILL ENOUGH MOISTURE FOR BRIEF HEAVY RAINFALL SHOULD DEEP CONVECTION DEVELOP. BASED ON GFS/ECMWF/NAM 00Z MODEL TRENDS...THINK THERE WILL BE A LULL IN RAINFALL SUN NIGHT INTO MONDAY EXCEPT FOR THE OFFSHORE AREAS. ALL MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE CLOSED LOW DROPPING A LITTLE FARTHER SOUTH THAN PREVIOUS MODEL RUNS AND COMING ACROSS C MEXICO ON MONDAY INTO MON NIGHT. THINK STRONGER LARGE SCALE ASCENT WILL MOVE OVER THE AREA MON NIGHT INTO TUE MORNING SO HAVE HIGHER RAIN CHANCES DURING THIS TIME. IT APPEARS WITH A FARTHER SOUTH TRACK OF THE LOW THAT MOST OF THE PRECIP WILL BE OFF THE GULF COAST BUT STILL HELD ONTO SOME HIGHER RAIN CHANCES FOR THE COASTAL COUNTIES. UPPER LOW THEN MOVES ALONG THE N GULF TUE INTO TUE NIGHT WITH RAIN CHANCES ENDING. AGAIN BECOMING LESS CONCERNED ABOUT HEAVY RAINFALL AS IT SEEMS THAT THREAT WILL BE OVER THE GULF COASTAL WATERS. STILL POSSIBLE FOR A FEW AREAS ALONG THE COAST TO PICK UP A HALF INCH TO AN INCH OF RAINFALL. GFS/ECMWF STILL ON TRACK WITH NEXT COLD FRONTAL PASSAGE WED MORNING. NAM LAGS BEHIND BY ABOUT 6 HRS. FORECAST WILL KEEP WITH CONSISTENT TRENDS OF THE ECMWF/GFS. AIRMASS BEHIND THE FRONT SHOULD BE DRY AND COLD ADVECTION WILL BE STRONGEST WED AFTERNOON AS 850MB TEMPS DROP SHARPLY DURING THE DAY. MIN TEMPS THUR MORNING SHOULD DROP BACK INTO THE 30S/40S FOR THE AREA AS HIGH PRESSURE SETTLES OVER THE HILL COUNTRY. RETURN FLOW SETS UP FRI INTO SAT TO END THE WEEK. INTRODUCED SOME LOW RAIN CHANCES FOR SHOWERS COMING OFF THE GULF IN THE EXTENDED FORECAST. LOOKS LIKE THE MODELS ARE TRYING TO COME TOGETHER WITH ANOTHER STRONG FRONTAL PASSAGE FOR NEXT SUNDAY. 39 MARINE... THE COLD FRONT HAS MOVED INTO THE COASTAL WATERS THIS MORNING WITH MODERATE NORTHEAST WINDS IN ITS WAKE. WILL CARRY CAUTION FOR ALL WATERS EXCEPT GALVESTON BAY AND ITS ASSOCIATED NEARSHORE WATERS THROUGH MIDDAY. EASTERLY FLOW WILL CONTINUE THROUGH MONDAY AS LOW PRESSURE DEVELOPS IN THE WESTERN GULF. AS THIS SYSTEM MOVES EAST ON TUESDAY WINDS WILL BECOME WESTERLY. A STRONG COLD FRONT WILL MOVE OFFSHORE WEDNESDAY MORNING WITH ADVISORY CONDITIONS LIKELY IN ITS WAKE. 38 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 53 46 70 53 77 / 10 10 30 30 10 HOUSTON (IAH) 56 50 71 54 76 / 20 20 30 50 30 GALVESTON (GLS) 60 54 65 57 70 / 50 20 40 60 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 PM CDT THIS AFTERNOON FOR THE FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...31 AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1051 AM CDT SUN MAR 9 2014 .UPDATE... LARGE OFFSHORE LIGHT RAIN SHIELD SLOWLY PULLING EAST THIS MORNING ...LIGHT RAIN ENDING ALONG THE COAST THIS HOUR. AFTER THIS EARLY MORNING MUCK OF LOW CEILINGS AND FOG CLEARS OUT WE WILL BE LEFT WITH AN OVERCAST...COOL AND DAMP DAY. CONVECTION FIRING EAST OF THE WESTERN GULF SURFACE TROUGH AXIS. THIS TROF WILL KEEP THE MAJORITY OF THE PRECIPITATION ACROSS THE WATERS THROUGH MONDAY MORNING...OCCASIONAL LIGHT SHOWERS FROM THE COASTAL BEND UP INTO THE MATAGORDA BAY REGION. ENSEMBLE SLOWING THE EASTERN PROGRESSION OF THE UPPER LOW OVER THE SONARA/CHIHUAHUA PROVINCES AND TAKING IT SOUTH OF SE`ERN TX EARLY TUESDAY THAT WILL KEEP THE HIGHEST POPS/QPF OVER THE COASTAL REGIONS/GULF LATE MONDAY THROUGH TUESDAY MORNING. SUBSEQUENT WEEK DAY WARMTH WITH CLEARING SKIES GOING INTO MID-WEEK. 31 && .PREV DISCUSSION... /ISSUED 644 AM CDT SUN MAR 9 2014/ DISCUSSION... SEE AVIATION FOR 12Z TAF DISCUSSION. AVIATION... AXIS OF LIGHT PRECIPITATION AFFECTING THE METRO AREA TERMINALS HAS BEGUN TO SLOWLY MOVE TOWARD THE COAST AND IS ALSO DIMINISHING IN COVERAGE. HI RES MODELS HAVE THIS AREA DIMINISHING BY LATE MORNING WITH PRECIPITATION COVERAGE SHIFTING FURTHER DOWN THE COAST. EXPECT IFR CIGS TO PERSIST THROUGH LATE MORNING BEFORE SLOW IMPROVEMENT THROUGH THE DAY. SOME CONCERN THAT NORTHERN SITES WILL SEE SOME FOG DEVELOPMENT TONIGHT DUE TO WET GROUND AND LIGHT WINDS BUT CONFIDENCE IN THIS IS LOW ENOUGH TO KEEP MENTION OUT OF THIS TAF PACKAGE. 38 && PREV DISCUSSION... /ISSUED 451 AM CDT SUN MAR 9 2014/ DISCUSSION... AREA RADAR SHOW SOME RAIN STRETCHING MAINLY NORTH OF I-10 WITH A BROAD AREA OF RAIN BACK TOWARDS VICTORIA. SFC COLD FRONT HAS JUST PUSHED OFF THE COAST WITH TEMPS IN THE 40S/50S BEHIND IT. UPPER AIR ANALYSIS HAS 850MB FRONT FROM W OF DFW TO JUST NORTH OF JCT. SEEMS THAT ISENTROPIC LIFT OVER THE FRONT HAS LED TO RAIN ACTIVITY OVER SE TX WHICH SEEMS TO BE DIMINISHING AS 925-850MB FLOW WEAKENS. ANALYSIS AT 500MB SHOWS BROAD TROUGHING FROM THE PLAINS BACK TO THE DESERT SW. WEAK UPPER LOW CONTINUES TO SHEAR OUT OVER THE S PLAINS WHILE SECOND LOW CONTINUES TO CLOSE OFF OVER NORTHERN MEXICO. WATER VAPOR IMAGERY DOES SHOW SOME COLDER CLOUD TOPS ASSOCIATED WITH LIFT FROM A WEAK SHORTWAVE TROUGH COMING ACROSS S TX. THIS SEEMS TO BE FORCING MODERATE RAIN BACK TO THE SW NEAR VCT. BASED ON THESE TRENDS DECIDED TO GO WITH HIGHER POPS ALONG THE COAST MAINLY 60/70 PERCENT. 06Z RUN OF HRRR SEEMS TO SUPPORT THIS IDEA ALONG WITH DECREASING RAIN CHANCES FOR THE AFTERNOON. DO NOT THINK HEAVY RAINFALL WILL BE MUCH OF AN ISSUE. LOOKS LIKE 1.5 INCH PRECIP WATER VALUES WILL STAY OVER THE GULF. STILL ENOUGH MOISTURE FOR BRIEF HEAVY RAINFALL SHOULD DEEP CONVECTION DEVELOP. BASED ON GFS/ECMWF/NAM 00Z MODEL TRENDS...THINK THERE WILL BE A LULL IN RAINFALL SUN NIGHT INTO MONDAY EXCEPT FOR THE OFFSHORE AREAS. ALL MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE CLOSED LOW DROPPING A LITTLE FARTHER SOUTH THAN PREVIOUS MODEL RUNS AND COMING ACROSS C MEXICO ON MONDAY INTO MON NIGHT. THINK STRONGER LARGE SCALE ASCENT WILL MOVE OVER THE AREA MON NIGHT INTO TUE MORNING SO HAVE HIGHER RAIN CHANCES DURING THIS TIME. IT APPEARS WITH A FARTHER SOUTH TRACK OF THE LOW THAT MOST OF THE PRECIP WILL BE OFF THE GULF COAST BUT STILL HELD ONTO SOME HIGHER RAIN CHANCES FOR THE COASTAL COUNTIES. UPPER LOW THEN MOVES ALONG THE N GULF TUE INTO TUE NIGHT WITH RAIN CHANCES ENDING. AGAIN BECOMING LESS CONCERNED ABOUT HEAVY RAINFALL AS IT SEEMS THAT THREAT WILL BE OVER THE GULF COASTAL WATERS. STILL POSSIBLE FOR A FEW AREAS ALONG THE COAST TO PICK UP A HALF INCH TO AN INCH OF RAINFALL. GFS/ECMWF STILL ON TRACK WITH NEXT COLD FRONTAL PASSAGE WED MORNING. NAM LAGS BEHIND BY ABOUT 6 HRS. FORECAST WILL KEEP WITH CONSISTENT TRENDS OF THE ECMWF/GFS. AIRMASS BEHIND THE FRONT SHOULD BE DRY AND COLD ADVECTION WILL BE STRONGEST WED AFTERNOON AS 850MB TEMPS DROP SHARPLY DURING THE DAY. MIN TEMPS THUR MORNING SHOULD DROP BACK INTO THE 30S/40S FOR THE AREA AS HIGH PRESSURE SETTLES OVER THE HILL COUNTRY. RETURN FLOW SETS UP FRI INTO SAT TO END THE WEEK. INTRODUCED SOME LOW RAIN CHANCES FOR SHOWERS COMING OFF THE GULF IN THE EXTENDED FORECAST. LOOKS LIKE THE MODELS ARE TRYING TO COME TOGETHER WITH ANOTHER STRONG FRONTAL PASSAGE FOR NEXT SUNDAY. 39 && MARINE... THE COLD FRONT HAS MOVED INTO THE COASTAL WATERS THIS MORNING WITH MODERATE NORTHEAST WINDS IN ITS WAKE. WILL CARRY CAUTION FOR ALL WATERS EXCEPT GALVESTON BAY AND ITS ASSOCIATED NEARSHORE WATERS THROUGH MIDDAY. EASTERLY FLOW WILL CONTINUE THROUGH MONDAY AS LOW PRESSURE DEVELOPS IN THE WESTERN GULF. AS THIS SYSTEM MOVES EAST ON TUESDAY WINDS WILL BECOME WESTERLY. A STRONG COLD FRONT WILL MOVE OFFSHORE WEDNESDAY MORNING WITH ADVISORY CONDITIONS LIKELY IN ITS WAKE. 38 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 53 46 70 53 77 / 10 10 30 30 10 HOUSTON (IAH) 56 50 71 54 76 / 20 20 30 50 30 GALVESTON (GLS) 60 54 65 57 70 / 50 20 40 60 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 PM CDT THIS AFTERNOON FOR THE FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
644 AM CDT SUN MAR 9 2014 .DISCUSSION... SEE AVIATION FOR 12Z TAF DISCUSSION. && .AVIATION... AXIS OF LIGHT PRECIPITATION AFFECTING THE METRO AREA TERMINALS HAS BEGUN TO SLOWLY MOVE TOWARD THE COAST AND IS ALSO DIMINISHING IN COVERAGE. HI RES MODELS HAVE THIS AREA DIMINISHING BY LATE MORNING WITH PRECIPITATION COVERAGE SHIFTING FURTHER DOWN THE COAST. EXPECT IFR CIGS TO PERSIST THROUGH LATE MORNING BEFORE SLOW IMPROVEMENT THROUGH THE DAY. SOME CONCERN THAT NORTHERN SITES WILL SEE SOME FOG DEVELOPMENT TONIGHT DUE TO WET GROUND AND LIGHT WINDS BUT CONFIDENCE IN THIS IS LOW ENOUGH TO KEEP MENTION OUT OF THIS TAF PACKAGE. 38 && .PREV DISCUSSION... /ISSUED 451 AM CDT SUN MAR 9 2014/ DISCUSSION... AREA RADAR SHOW SOME RAIN STRETCHING MAINLY NORTH OF I-10 WITH A BROAD AREA OF RAIN BACK TOWARDS VICTORIA. SFC COLD FRONT HAS JUST PUSHED OFF THE COAST WITH TEMPS IN THE 40S/50S BEHIND IT. UPPER AIR ANALYSIS HAS 850MB FRONT FROM W OF DFW TO JUST NORTH OF JCT. SEEMS THAT ISENTROPIC LIFT OVER THE FRONT HAS LED TO RAIN ACTIVITY OVER SE TX WHICH SEEMS TO BE DIMINISHING AS 925-850MB FLOW WEAKENS. ANALYSIS AT 500MB SHOWS BROAD TROUGHING FROM THE PLAINS BACK TO THE DESERT SW. WEAK UPPER LOW CONTINUES TO SHEAR OUT OVER THE S PLAINS WHILE SECOND LOW CONTINUES TO CLOSE OFF OVER NORTHERN MEXICO. WATER VAPOR IMAGERY DOES SHOW SOME COLDER CLOUD TOPS ASSOCIATED WITH LIFT FROM A WEAK SHORTWAVE TROUGH COMING ACROSS S TX. THIS SEEMS TO BE FORCING MODERATE RAIN BACK TO THE SW NEAR VCT. BASED ON THESE TRENDS DECIDED TO GO WITH HIGHER POPS ALONG THE COAST MAINLY 60/70 PERCENT. 06Z RUN OF HRRR SEEMS TO SUPPORT THIS IDEA ALONG WITH DECREASING RAIN CHANCES FOR THE AFTERNOON. DO NOT THINK HEAVY RAINFALL WILL BE MUCH OF AN ISSUE. LOOKS LIKE 1.5 INCH PRECIP WATER VALUES WILL STAY OVER THE GULF. STILL ENOUGH MOISTURE FOR BRIEF HEAVY RAINFALL SHOULD DEEP CONVECTION DEVELOP. BASED ON GFS/ECMWF/NAM 00Z MODEL TRENDS...THINK THERE WILL BE A LULL IN RAINFALL SUN NIGHT INTO MONDAY EXCEPT FOR THE OFFSHORE AREAS. ALL MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE CLOSED LOW DROPPING A LITTLE FARTHER SOUTH THAN PREVIOUS MODEL RUNS AND COMING ACROSS C MEXICO ON MONDAY INTO MON NIGHT. THINK STRONGER LARGE SCALE ASCENT WILL MOVE OVER THE AREA MON NIGHT INTO TUE MORNING SO HAVE HIGHER RAIN CHANCES DURING THIS TIME. IT APPEARS WITH A FARTHER SOUTH TRACK OF THE LOW THAT MOST OF THE PRECIP WILL BE OFF THE GULF COAST BUT STILL HELD ONTO SOME HIGHER RAIN CHANCES FOR THE COASTAL COUNTIES. UPPER LOW THEN MOVES ALONG THE N GULF TUE INTO TUE NIGHT WITH RAIN CHANCES ENDING. AGAIN BECOMING LESS CONCERNED ABOUT HEAVY RAINFALL AS IT SEEMS THAT THREAT WILL BE OVER THE GULF COASTAL WATERS. STILL POSSIBLE FOR A FEW AREAS ALONG THE COAST TO PICK UP A HALF INCH TO AN INCH OF RAINFALL. GFS/ECMWF STILL ON TRACK WITH NEXT COLD FRONTAL PASSAGE WED MORNING. NAM LAGS BEHIND BY ABOUT 6 HRS. FORECAST WILL KEEP WITH CONSISTENT TRENDS OF THE ECMWF/GFS. AIRMASS BEHIND THE FRONT SHOULD BE DRY AND COLD ADVECTION WILL BE STRONGEST WED AFTERNOON AS 850MB TEMPS DROP SHARPLY DURING THE DAY. MIN TEMPS THUR MORNING SHOULD DROP BACK INTO THE 30S/40S FOR THE AREA AS HIGH PRESSURE SETTLES OVER THE HILL COUNTRY. RETURN FLOW SETS UP FRI INTO SAT TO END THE WEEK. INTRODUCED SOME LOW RAIN CHANCES FOR SHOWERS COMING OFF THE GULF IN THE EXTENDED FORECAST. LOOKS LIKE THE MODELS ARE TRYING TO COME TOGETHER WITH ANOTHER STRONG FRONTAL PASSAGE FOR NEXT SUNDAY. 39 MARINE... THE COLD FRONT HAS MOVED INTO THE COASTAL WATERS THIS MORNING WITH MODERATE NORTHEAST WINDS IN ITS WAKE. WILL CARRY CAUTION FOR ALL WATERS EXCEPT GALVESTON BAY AND ITS ASSOCIATED NEARSHORE WATERS THROUGH MIDDAY. EASTERLY FLOW WILL CONTINUE THROUGH MONDAY AS LOW PRESSURE DEVELOPS IN THE WESTERN GULF. AS THIS SYSTEM MOVES EAST ON TUESDAY WINDS WILL BECOME WESTERLY. A STRONG COLD FRONT WILL MOVE OFFSHORE WEDNESDAY MORNING WITH ADVISORY CONDITIONS LIKELY IN ITS WAKE. 38 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 56 46 70 53 77 / 30 10 30 30 10 HOUSTON (IAH) 59 49 71 54 76 / 40 20 30 50 30 GALVESTON (GLS) 60 53 65 57 70 / 60 20 40 60 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 PM CDT THIS AFTERNOON FOR THE FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...39 AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
451 AM CDT SUN MAR 9 2014 .DISCUSSION... AREA RADAR SHOW SOME RAIN STRETCHING MAINLY NORTH OF I-10 WITH A BROAD AREA OF RAIN BACK TOWARDS VICTORIA. SFC COLD FRONT HAS JUST PUSHED OFF THE COAST WITH TEMPS IN THE 40S/50S BEHIND IT. UPPER AIR ANALYSIS HAS 850MB FRONT FROM W OF DFW TO JUST NORTH OF JCT. SEEMS THAT ISENTROPIC LIFT OVER THE FRONT HAS LED TO RAIN ACTIVITY OVER SE TX WHICH SEEMS TO BE DIMINISHING AS 925-850MB FLOW WEAKENS. ANALYSIS AT 500MB SHOWS BROAD TROUGHING FROM THE PLAINS BACK TO THE DESERT SW. WEAK UPPER LOW CONTINUES TO SHEAR OUT OVER THE S PLAINS WHILE SECOND LOW CONTINUES TO CLOSE OFF OVER NORTHERN MEXICO. WATER VAPOR IMAGERY DOES SHOW SOME COLDER CLOUD TOPS ASSOCIATED WITH LIFT FROM A WEAK SHORTWAVE TROUGH COMING ACROSS S TX. THIS SEEMS TO BE FORCING MODERATE RAIN BACK TO THE SW NEAR VCT. BASED ON THESE TRENDS DECIDED TO GO WITH HIGHER POPS ALONG THE COAST MAINLY 60/70 PERCENT. 06Z RUN OF HRRR SEEMS TO SUPPORT THIS IDEA ALONG WITH DECREASING RAIN CHANCES FOR THE AFTERNOON. DO NOT THINK HEAVY RAINFALL WILL BE MUCH OF AN ISSUE. LOOKS LIKE 1.5 INCH PRECIP WATER VALUES WILL STAY OVER THE GULF. STILL ENOUGH MOISTURE FOR BRIEF HEAVY RAINFALL SHOULD DEEP CONVECTION DEVELOP. BASED ON GFS/ECMWF/NAM 00Z MODEL TRENDS...THINK THERE WILL BE A LULL IN RAINFALL SUN NIGHT INTO MONDAY EXCEPT FOR THE OFFSHORE AREAS. ALL MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE CLOSED LOW DROPPING A LITTLE FARTHER SOUTH THAN PREVIOUS MODEL RUNS AND COMING ACROSS C MEXICO ON MONDAY INTO MON NIGHT. THINK STRONGER LARGE SCALE ASCENT WILL MOVE OVER THE AREA MON NIGHT INTO TUE MORNING SO HAVE HIGHER RAIN CHANCES DURING THIS TIME. IT APPEARS WITH A FARTHER SOUTH TRACK OF THE LOW THAT MOST OF THE PRECIP WILL BE OFF THE GULF COAST BUT STILL HELD ONTO SOME HIGHER RAIN CHANCES FOR THE COASTAL COUNTIES. UPPER LOW THEN MOVES ALONG THE N GULF TUE INTO TUE NIGHT WITH RAIN CHANCES ENDING. AGAIN BECOMING LESS CONCERNED ABOUT HEAVY RAINFALL AS IT SEEMS THAT THREAT WILL BE OVER THE GULF COASTAL WATERS. STILL POSSIBLE FOR A FEW AREAS ALONG THE COAST TO PICK UP A HALF INCH TO AN INCH OF RAINFALL. GFS/ECMWF STILL ON TRACK WITH NEXT COLD FRONTAL PASSAGE WED MORNING. NAM LAGS BEHIND BY ABOUT 6 HRS. FORECAST WILL KEEP WITH CONSISTENT TRENDS OF THE ECMWF/GFS. AIRMASS BEHIND THE FRONT SHOULD BE DRY AND COLD ADVECTION WILL BE STRONGEST WED AFTERNOON AS 850MB TEMPS DROP SHARPLY DURING THE DAY. MIN TEMPS THUR MORNING SHOULD DROP BACK INTO THE 30S/40S FOR THE AREA AS HIGH PRESSURE SETTLES OVER THE HILL COUNTRY. RETURN FLOW SETS UP FRI INTO SAT TO END THE WEEK. INTRODUCED SOME LOW RAIN CHANCES FOR SHOWERS COMING OFF THE GULF IN THE EXTENDED FORECAST. LOOKS LIKE THE MODELS ARE TRYING TO COME TOGETHER WITH ANOTHER STRONG FRONTAL PASSAGE FOR NEXT SUNDAY. 39 && .MARINE... THE COLD FRONT HAS MOVED INTO THE COASTAL WATERS THIS MORNING WITH MODERATE NORTHEAST WINDS IN ITS WAKE. WILL CARRY CAUTION FOR ALL WATERS EXCEPT GALVESTON BAY AND ITS ASSOCIATED NEARSHORE WATERS THROUGH MIDDAY. EASTERLY FLOW WILL CONTINUE THROUGH MONDAY AS LOW PRESSURE DEVELOPS IN THE WESTERN GULF. AS THIS SYSTEM MOVES EAST ON TUESDAY WINDS WILL BECOME WESTERLY. A STRONG COLD FRONT WILL MOVE OFFSHORE WEDNESDAY MORNING WITH ADVISORY CONDITIONS LIKELY IN ITS WAKE. 38 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 56 46 70 53 77 / 30 10 30 30 10 HOUSTON (IAH) 59 49 71 54 76 / 40 20 30 50 30 GALVESTON (GLS) 60 53 65 57 70 / 60 20 40 60 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 PM CDT THIS AFTERNOON FOR THE FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...39 AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS SPOKANE WA
624 PM PDT Mon Mar 10 2014 .SYNOPSIS... Rain and snow will be ending overnight Monday. Quieter weather is expected through Thursday. A weak weather front will bring light rain to the area on Friday, with another chance of rain late Sunday into next Monday. && .DISCUSSION... Made some updates to the forecast for this evening into tonight. I trimmed out showers in the Spokane/Coeur d`Alene area and up much of the Northern Panhandle. The surface low has pushed well into Montana with the stratiform precip winding down across much of the Central Panhandle Mountains (although some snow can be expected over Lookout Pass this evening). The Spokane/Coeur d`Alene areas did not see enough warming in the afternoon to achieve our convective temperature; however, areas to the north and west are seeing isolated showers developing. Temperatures are a bit too cold for lightening with these showers, but thermal profiles are more conducive for thunderstorms in the southeast from the Northeast Blue Mtns to the Camas Prairie. Showers and thunderstorms are expected to diminish this evening with skies clearing. /SVH && .AVIATION... 00Z TAFS: Isolated and scattered afternoon showers will continue across the northern mtns and across extreme southeast WA and into the ID Panhandle. These showers will generally only affect the KPUW and KLWS TAF sites. An isolated lightning strike will also be possible through about 02Z. Drier air out of Canada will result in clearing skies through this evening. Fog or low stratus will be possible late tonight into early Tuesday morning at KSFF, KGEG, KCOE, KPUW and KLWS, but confidence is low due to the dry air intrusion. /SVH && .PREV DISCUSSION... /ISSUED 453 PM PDT Mon Mar 10 2014/ SYNOPSIS... Rain and snow will be ending overnight Monday. Quieter weather is expected through Thursday. A weak weather front will bring light rain to the area on Friday, with another chance of rain late Sunday into next Monday. DISCUSSION... Tonight...cold pool and its associated instability located behind a passing cold front all exit to the southeast and east tonight. Small scale triggers rotating around the edges of a small scale low pressure area nested in this same cooler air will act as triggers. Additionally there is an increase in instability due to surface heating allowed by sun breaks across parts of the lowlands between the east side of the Cascades and the Idaho Panhandle. For all these reasons and a number of HRRR model runs depicting just such a scenario the forecast holds onto showers along with very low wet bulb zero heights allowing for a typical spring rain/snow/graupel/soft-hail mix of precipitation for mid-slope down to valley and lowland locations with the expectation that any accumulation associated with most intense convective cells will be on the order of minutes rather than hours if at all. Thunderstorm mention remains southeast third of Washington and southern half of North Idaho into early evening with idea that they will be weak, low topped, single or multicell type with potential to produce heavy rain and small soft hail/collapsed snow and gusty wind. Storm motion should be southeast at about 25-35 mph. /Pelatti Tuesday through next Monday: High pressure builds into the area on Tuesday for drier conditions. We will likely see some late night/morning fog and low clouds in the valleys, but otherwise should be nice weather. A minor weather system clips by to our north on Wednesday evening but we don`t expect much weather from this, other than some perhaps some mountain wind. The next real good chance of precipitation arrives on Friday. This system has a decent moisture tap. But the westerly flow will keep the precipitation largely confined to the Cascades and Panhandle mountains. ECMWF is slightly slower and wetter than the GFS. Snow levels will remain high (6000` south, 5000` north) so there will be little if any impact from this system. Does not look like enough rain to cause any flooding concerns. The weather system on it`s heels looks a little more formidable. This wave has a narrow but well-defined moisture plume associated with it. Initially it looks impressive with heavy rain pointed into Vancouver Island and NW Washington. But as it moves eastward, the GFS model spins up a low along this front well to our south (west of San Francisco). This cuts off the moisture supply and we are left with a dying frontal passage. The ECMWF meanwhile doesn`t show this, and has a more consolidated wet front moving through on Sunday night. Temperatures ahead of this front have the potential to be the warmest of the season so far, nearing 60F in the Spokane area. But it won`t take much change in the timing to render a cooler and wetter day for Sunday than currently forecast. Snow levels will be very high (7000-8000`) so the passes will be all rain. The snow levels lower by Monday morning and continue to lower during the day. RJ && .PRELIMINARY POINT TEMPS/POPS... Spokane 30 48 27 53 32 55 / 10 0 0 0 0 0 Coeur d`Alene 29 47 26 52 30 54 / 10 0 0 0 0 0 Pullman 32 48 28 54 34 55 / 50 0 0 0 0 0 Lewiston 35 54 33 60 36 62 / 40 0 0 0 0 0 Colville 29 53 26 54 27 55 / 20 0 0 0 0 0 Sandpoint 28 45 24 47 28 50 / 10 0 0 0 10 10 Kellogg 30 45 29 49 31 50 / 40 10 0 0 0 0 Moses Lake 32 55 30 57 33 60 / 10 0 0 0 0 0 Wenatchee 32 53 32 55 33 57 / 10 0 0 0 0 0 Omak 28 52 28 53 30 56 / 20 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
453 PM PDT Mon Mar 10 2014 .SYNOPSIS... Rain and snow will be ending overnight Monday. Quieter weather is expected through Thursday. A weak weather front will bring light rain to the area on Friday, with another chance of rain late Sunday into next Monday. && .DISCUSSION... Tonight...cold pool and its associated instability located behind a passing cold front all exit to the southeast and east tonight. Small scale triggers rotating around the edges of a small scale low pressure area nested in this same cooler air will act as triggers. Additionally there is an increase in instability due to surface heating allowed by sun breaks across parts of the lowlands between the east side of the Cascades and the Idaho Panhandle. For all these reasons and a number of HRRR model runs depicting just such a scenario the forecast holds onto showers along with very low wet bulb zero heights allowing for a typical spring rain/snow/graupel/soft-hail mix of precipitation for mid-slope down to valley and lowland locations with the expectation that any accumulation associated with most intense convective cells will be on the order of minutes rather than hours if at all. Thunderstorm mention remains southeast third of Washington and southern half of North Idaho into early evening with idea that they will be weak, low topped, single or multicell type with potential to produce heavy rain and small soft hail/collapsed snow and gusty wind. Storm motion should be southeast at about 25-35 mph. /Pelatti Tuesday through next Monday: High pressure builds into the area on Tuesday for drier conditions. We will likely see some late night/morning fog and low clouds in the valleys, but otherwise should be nice weather. A minor weather system clips by to our north on Wednesday evening but we don`t expect much weather from this, other than some perhaps some mountain wind. The next real good chance of precipitation arrives on Friday. This system has a decent moisture tap. But the westerly flow will keep the precipitation largely confined to the Cascades and Panhandle mountains. ECMWF is slightly slower and wetter than the GFS. Snow levels will remain high (6000` south, 5000` north) so there will be little if any impact from this system. Does not look like enough rain to cause any flooding concerns. The weather system on it`s heels looks a little more formidable. This wave has a narrow but well-defined moisture plume associated with it. Initially it looks impressive with heavy rain pointed into Vancouver Island and NW Washington. But as it moves eastward, the GFS model spins up a low along this front well to our south (west of San Francisco). This cuts off the moisture supply and we are left with a dying frontal passage. The ECMWF meanwhile doesn`t show this, and has a more consolidated wet front moving through on Sunday night. Temperatures ahead of this front have the potential to be the warmest of the season so far, nearing 60F in the Spokane area. But it won`t take much change in the timing to render a cooler and wetter day for Sunday than currently forecast. Snow levels will be very high (7000-8000`) so the passes will be all rain. The snow levels lower by Monday morning and continue to lower during the day. RJ && .AVIATION... 00Z TAFS: Isolated and scattered afternoon showers will continue across the northern mtns and across extreme southeast WA and into the ID Panhandle. These showers will generally only affect the KPUW and KLWS TAF sites. An isolated lightning strike will also be possible through about 02Z. Drier air out of Canada will result in clearing skies through this evening. Fog or low stratus will be possible late tonight into early Tuesday morning at KSFF, KGEG, KCOE, KPUW and KLWS, but confidence is low due to the dry air intrusion. /SVH && .PRELIMINARY POINT TEMPS/POPS... Spokane 30 48 27 53 32 55 / 20 0 0 0 0 0 Coeur d`Alene 29 47 26 52 30 54 / 20 0 0 0 0 0 Pullman 32 48 28 54 34 55 / 70 0 0 0 0 0 Lewiston 35 54 33 60 36 62 / 60 0 0 0 0 0 Colville 29 53 26 54 27 55 / 20 0 0 0 0 0 Sandpoint 28 45 24 47 28 50 / 20 0 0 0 10 10 Kellogg 30 45 29 49 31 50 / 60 10 0 0 0 0 Moses Lake 32 55 30 57 33 60 / 10 0 0 0 0 0 Wenatchee 32 53 32 55 33 57 / 0 0 0 0 0 0 Omak 28 52 28 53 30 56 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
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AREA FORECAST DISCUSSION
NWS LA CROSSE WI
640 AM CDT SUN MAR 9 2014 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 326 AM CDT SUN MAR 9 2014 HIGH PRESSURE CENTERED OVER NORTHERN MISSOURI THIS MORNING WILL CONTINUE TO SINK SOUTHEAST REACHING THE OHIO RIVER VALLEY TODAY. WARM AIR ADVECTION ON THE BACK SIDE OF THE HIGH WILL BRING WARMER AIR OVER THE REGION AND THE QUESTION BECOMES HOW WARM WILL TEMPERATURES GET OVER THE NEXT COUPLE OF DAYS GIVEN THE 10 TO 25 INCHES OF SNOW CURRENTLY SITTING ON THE GROUND. THE 09.00Z GFS SUGGEST 925 MB TEMPERATURES FOR LATE THIS AFTERNOON SHOULD RANGE FROM ABOUT 0C ACROSS THE NORTH TO 7C IN THE SOUTH. THE WARMEST AIR SHOULD BE OVER THE AREA TONIGHT WHEN 10C AIR AT 925 MB GETS INTO THE SOUTHERN AREAS BEFORE COOLING TAKES OVER MONDAY WITH VALUES RETURNING TO SIMILAR LEVELS THAT ARE EXPECTED FOR TODAY. THE BUFKIT SOUNDINGS FROM THE GFS SHOW VERY LIMITED MIXING TO OCCUR OVER THE NEXT TWO DAYS...WITH THE TOP OF THE MIXED LAYER POSSIBLY REACHING INTO THIS WARMER AIR AT 925 MB. THE OTHER COMPLICATING FACTOR IS THE SNOW PACK AND A LOOK BACK AT PAST EVENTS SHOWS KRST HAS NEVER TOPPED 45 DEGREES WITH 20 INCHES OF SNOW ON THE GROUND WHILE KLSE HAS HIT 50 DEGREES ONLY ABOUT 5 TIMES WITH ANY AMOUNT OF SNOW PACK. WHILE THE SUN ANGLE CONTINUES TO INCREASE...JUST DO NOT FEEL THERE WILL BE ENOUGH ENERGY FROM THE SUN TO OVERCOME THE SNOW PACK AND WITH WEAK COLD AIR ADVECTION OCCURRING MONDAY...DROPPED THE TEMPERATURES BACK JUST A LITTLE BIT FROM THE PREVIOUS FORECAST. THE NEXT CHANCE FOR SOME PRECIPITATION WILL START MONDAY NIGHT AND CONTINUE THROUGH TUESDAY. ENERGY COMING IN OFF THE PACIFIC TONIGHT WILL SEND A SHORT WAVE TROUGH FROM THE HIGH PLAINS TOWARD THE OHIO RIVER VALLEY. AT THE SAME TIME...ANOTHER SHORT WAVE TROUGH WILL BE APPROACHING FROM THE NORTH IN THE NORTHERN STREAM. MOST OF THE FORCING FROM THE PACIFIC SHORT WAVE TROUGH WILL MISS THE AREA TO THE SOUTH...WHILE THE NORTHERN STREAM SHORT WAVE TROUGH SHOULD PRODUCE MODERATE TO STRONG PV ADVECTION IN THE 500-300 MB LAYER. MODERATE QG CONVERGENCE IN THE 1000-700 MB LAYER SHOULD OCCUR WITH THESE WAVES MONDAY NIGHT AND TUESDAY MORNING OVER THE SOUTHERN HALF OF THE AREA WITH WEAK CONVERGENCE IN THE UPPER LEVELS. THE STRONGEST FRONTOGENESIS LOOKS TO BE IN THE 850-700 MB LAYER...BUT LOOKS TO SET UP MORE ACROSS CENTRAL INTO SOUTHERN IOWA WITH SOME WEAK FRONTOGENESIS IN THE 700-500 MB LAYER. EXPECT THAT THERE WILL BE ENOUGH FORCING TO PRODUCE A BAND OF PRECIPITATION ACROSS MAINLY THE SOUTHERN SECTIONS OF THE AREA AND RAISED THE CHANCES UP TO 70 PERCENT FOR NORTHEAST IOWA INTO SOUTHWEST WISCONSIN. SOME CONCERN WITH PRECIPITATION TYPES AT THE ONSET. LOOK LIKE ICE SHOULD BE PRESENT IN THE CLOUDS BUT WITH A WARM LAYER ALOFT BETWEEN 900 AND 850 MB. THIS WILL LIKELY PRODUCE SOME PARTIAL MELTING WITH THE POSSIBILITY OF SOME SLEET OCCURRING. OTHERWISE...LOOKS LIKE A RAIN/SNOW MIX POSSIBLE BASED ON SURFACE TEMPERATURES. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 326 AM CDT SUN MAR 9 2014 THE LINGERING PRECIPITATION FROM TUESDAY SHOULD EXIT THE REGION DURING THE EVENING AND REMOVED THE PRECIPITATION CHANCES FOR THE OVERNIGHT HOURS. NORTHWEST FLOW ALOFT WILL SET UP BEHIND THE DEPARTING SYSTEM WITH THE MODELS ALL SHOWING A SHORT WAVE TROUGH IN THIS FLOW FOR THURSDAY NIGHT AND FRIDAY. DIFFERENCES THOUGH BETWEEN THE MODELS ON HOW FAR SOUTH THIS WAVE WILL BE ALONG WITH THE ASSOCIATED SURFACE LOW. THE 09.00Z ECMWF IS THE FARTHEST SOUTH AND CURRENTLY THE ONLY MODEL SUGGESTING ANY PRECIPITATION IN THIS TIME FRAME WITH THE GFS AND 09.00Z GEM KEEPING THE PRECIPITATION OFF TO THE NORTHEAST ACROSS THE GREAT LAKES. UNTIL MORE OF A MODEL CONSENSUS DEVELOPS...WILL KEEP THE FORECAST DRY WITH TEMPERATURES AGAIN MODERATING INTO THE 40S FOR THE END OF THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 639 AM CDT SUN MAR 9 2014 MID AND HIGH CLOUDS /MAINLY ABOVE 15K FEET/ MOVED INTO THE AREA OVERNIGHT. THESE CLOUDS ARE ASSOCIATED WITH A SHORT WAVE MOVING THROUGH SOUTHERN MANITOBA. THESE CLOUDS WILL GRADUALLY LOWER TO AROUND 10K FEET THIS EVENING...AND THEN SKIES WILL CLEAR AS SUBSIDENCE MOVES INTO THE AREA OVERNIGHT. BOTH THE RAP AND NAM INDICATE THAT THERE WILL BE A POSSIBILITY OF LOW LEVEL WIND SHEAR DEVELOPING AT KRST BY 09.17Z. THIS IS DUE TO THE LOW LEVEL INVERSION REMAINING INTACT AND NOT ALLOWING THE WINDS TO BECOME GUSTY. MEANWHILE THE GFS DOES DEVELOP SOME GUSTS INTO THE 25 TO 30 KNOT RANGE. SINCE THE NAM AND RAP USUALLY HAVE PROBLEMS WITH NOT ERODING THE LOW LEVEL INVERSIONS IN THIS SYNOPTIC PATTERN OPTED TO GO MORE TOWARDS THE GFS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS NEW YORK NY
506 AM EDT TUE MAR 11 2014 .SYNOPSIS... WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY. STRONG LOW PRESSURE WILL THEN MOVE THROUGH WEDNESDAY INTO WEDNESDAY NIGHT...FOLLOWED BY BUILDING HIGH PRESSURE THURSDAY THROUGH FRIDAY. A COLD FRONT WILL PASS THROUGH ON SATURDAY... WITH HIGH PRESSURE BUILDING IN BRIEFLY ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WEAK COLD FRONT WAS JUST WEST OF THE AREA AS OF 08Z. THE FRONT SHOULD MOVE THROUGH BY DAYBREAK...FOLLOWED BY DOWNSLOPE WNW FLOW THAT ALONG WITH PARTIAL SUNSHINE SHOULD HELP BOOST TEMPS TO 55-60 ACROSS NYC METRO AND MOST OF LONG ISLAND...AND 50-55 TO THE NORTH...SEVERAL DEGREES WARMER THAN A 00Z GFS/NAM MOS GUIDANCE BLEND. THE 06Z RAP SUGGESTS THAT TEMPS COULD EVEN REACH THE LOWER 60S INVOF NYC WITH ENOUGH AFTERNOON SUNSHINE...BUT HAVE DOUBTS AS TO WHETHER IT WILL GET THIS WARM AS MID LEVEL CLOUDS WILL BE INCREASING LATE THIS AFTERNOON AHEAD OF THE APPROACHING STORM. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... CLOUDS WILL LOWER/THICKEN TONIGHT ESPECIALLY NORTH/WEST OF NYC... AHEAD OF LOW PRESSURE DEVELOPING IN THE OH VALLEY. OVERRUNNING LIGHT PRECIP SHOULD ALSO MOVE INTO AREAS MAINLY NORTH/WEST OF NYC AFTER MIDNIGHT. HAVE TRENDED WARMER TONIGHT...WITH LOWS 40-45 INVOF NYC AND 35-40 ELSEWHERE...AND WITH ELEVATED WARM NOSE MOVING IN PRECIP SHOULD START OFF AS RAIN THROUGHOUT. GFS/ECMWF RELATIVELY CLOSE ON DETAILS WED INTO WED NIGHT AS THE INTENSIFYING LOW MOVES OUT OF THE OHIO VALLEY AND PASSES NW OF NYC BY WED EVENING. THE BULK OF THE RAIN ON WED SHOULD BE NORTH OF THE LOW TRACK DURING THE DAYTIME IN THE COOL SECTOR. AS THE SUB-980 MB SFC LOW TRACKS OVER THE AREA JUST NW OF NYC AND THE COAST LATE WED AFTERNOON/EVENING...MOST IF NOT ALL THE CWA COULD GET INTO THE WARM SECTOR...WITH TEMPS RISING INTO THE 50S MAINLY ACROSS NYC METRO...NE NJ AND THE LOWER HUDSON VALLEY WHERE MARINE INFLUENCE WILL BE MINIMAL. A LINE OF FORCED LOW TOPPED CONVECTION IS LIKELY ALONG A TRAILING COLD FRONT...WHICH COULD PRODUCE STRONG WIND GUSTS ESPECIALLY ACROSS NE NJ AND NYC METRO WHERE SFC INSTABILITY LIKELY TO BE SFC-BASED AS BOTH TEMPS/DEWPOINTS RISE INTO THE 50S. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... MUCH COLDER AIR WILL MOVE IN BEHIND THE INTENSE LOW WED NIGHT AS IT DEPARTS TO THE GULF OF MAINE...WITH LOWS 20-25 AND POSSIBLY FALLING TO THE UPPER TEENS WELL INLAND. GIVEN THE MORE NORTHERLY LOW TRACK...HEAVIER PRECIP SHOULD ALSO REMAIN TO THE NORTH...SO LITTLE IF ANY ACCUMULATION EXPECTED LATE WED NIGHT AS PRECIP CHANGES OVER TO LIGHT SNOW OR SCT SNOW SHOWERS. THU AND THU NIGHT WILL BE BLUSTERY AND VERY COLD...WITH TEMPS NOT RISING MUCH IF AT ALL...REACHING THE MID AND UPPER 20S AT BEST. NW WINDS COULD REACH ADVY CRITERIA ESPECIALLY ACROSS NYC METRO AND LONG ISLAND. LOWS THEN EXPECTED TO FALL TO THE SINGLE DIGITS INLAND...TEENS MOST ELSEWHERE...AND LOWER 20S IN NYC. SEE CLIMATE SECTION FOR DETAILS ON RECORD COLD. THIS VERY COLD AIR MASS WILL BE SHORT LIVED...AS DEEP LAYER RIDGING BUILDS ACROSS WITH SW RETURN FLOW AND WAA ON FRI. LOW PRESSURE MOVING THROUGH SOUTHERN CANADA LATE FRI INTO SAT WILL DRAG A TRAILING COLD FRONT THROUGH BY MIDDAY SAT. SOME QUESTION ON THE EXTENT OF PCPN WITH THIS SYSTEM AS VERY DRY AIR INITIALLY IN PLACE WILL BE HARD TO OVERCOME. BETTER FORCING ALSO LOOKS TO BE TO THE NORTH...SO HAVE ONLY MENTIONED SLIGHT CHANCE POP. SUNDAY SHOULD BE DRY. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... W-SW WINDS WILL VEER AROUND TO THE W-NW BEHIND A WEAK TROF/COLD FRONT OVER THE NEXT COUPLE OF HOURS. FLOW WILL BE RIGHT AROUND 310 FROM MID MORNING TO MID AFTERNOON AT 7 TO 10 KT...BEFORE BACKING A BIT BY LATE AFT TO THE W. RIDGE AXIS BUILDS INTO THE AREA THIS EVE WITH A LIGHT AND VARIABLE FLOW. VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. THERE IS SOME CONCERN FOR MVFR CIGS DEVELOPING AFTER 06Z FOR THE 30H TAFS AHEAD OF AN APPROACHING WARM FRONT. CONFIDENCE IS LOW AT THIS TIME. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KEWR FCSTER COMMENTS: POSSIBLE GUSTS UP TO 17 KT FROM MID MORNING THROUGH EARLY AFTERNOON. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KJFK FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. POSSIBLE HYRID SEABREEZE WITH WINDS BACKING AROUND TO 230-250 LATE THIS AFTERNOON. KLGA FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. KTEB FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. KHPN FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. KISP FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. .OUTLOOK FOR 06Z WED THROUGH SAT... .WED-WED NIGHT...SUB-VFR IN RA. ESE-SE WINDS AROUND 10 KT GUSTING UP TO AROUND 20 KT LATE WED AFTN-EVE THEN W-NW WINDS AROUND 20 KT GUSTING UP TO 35 KT LATER WED NIGHT. .THU...IMPROVING TO VFR EARLY. NW G30-40KT. .FRI...VFR. .SAT...SUB-VFR POSSIBLE IN SHOWERS. && .MARINE... WINDS STARTING TO BACK SW AND GUST OVER 20 KT AT 44017. SHOULD SEE MINIMAL SCA CONDS FROM THERE ON EAST THIS MORNING...SO SCA REMAINS IN EFFECT ONLY ON THE OCEAN E OF MORICHES INLET. WINDS AND SEAS INCREASE ON WED WITH SOUTHERLY FLOW. SCA CRITERIA ARE LIKELY TO BE REACHED DURING THE SECOND HALF OF THE DAY. WINDS AND SEAS CONTINUE TO INCREASE INTO WEDNESDAY NIGHT...WITH GALES EXPECTED TO DEVELOP. THEREFORE...WENT AHEAD AND ISSUED A WATCH CONSIDERING THE HIGH AMOUNT OF CONFIDENCE IN THE STRENGTHENING WINDS WITH THE DEEPENING LOW PRESSURE MOVING OFF TO THE EAST. GALES THEN LOOK TO END THURSDAY NIGHT...BUT WINDS AND SEAS STILL REMAIN ELEVATED...WITH 5 FT SEAS NOT DIMINISHING ACROSS THE EASTERN OCEAN WATERS UNTIL AT LEAST FRIDAY MORNING. SCA CONDITIONS POSSIBLY RETURN LATE FRIDAY NIGHT INTO SATURDAY WITH ANOTHER APPROACHING SYSTEM OVER THE WEEKEND. && .HYDROLOGY... LOW TRACK AND THEREFORE ASSOCIATED QPF WITH THE MID WEEK STORM HAVE TRENDED NORTHWARD...SO ONLY EXPECT BASIN AVG QPF OF 1/2 TO 1 INCH FOR SOUTHERN CT...THE LOWER HUDSON VALLEY AND INTERIOR NE NJ. LOWER QPF OF 1/4 TO 1/2 INCH EXPECTED FOR NYC METRO AND LONG ISLAND. LOCAL AMTS OF ABOUT 1/2 INCH HIGHER ARE POSSIBLE IN TSTMS. THE BULK OF THIS PRECIP SHOULD BE RAIN. && .EQUIPMENT... THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER. FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION STATEMENT (ALL LOWER CASE): WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR ANZ330-335-338-340-345-350-353-355. SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ350. && $$ SYNOPSIS...GOODMAN/SEARS NEAR TERM...GOODMAN/PICCA SHORT TERM...GOODMAN/PICCA LONG TERM...GOODMAN/PICCA/SEARS AVIATION...DW MARINE...GOODMAN/PICCA/SEARS HYDROLOGY...GOODMAN EQUIPMENT...//
AREA FORECAST DISCUSSION
NWS NEW YORK NY
450 AM EDT TUE MAR 11 2014 .SYNOPSIS... WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY. STRONG LOW PRESSURE WILL THEN MOVE THROUGH WEDNESDAY INTO WEDNESDAY NIGHT...FOLLOWED BY BUILDING HIGH PRESSURE THURSDAY THROUGH FRIDAY. A COLD FRONT WILL PASS THROUGH ON SATURDAY... WITH HIGH PRESSURE BUILDING IN BRIEFLY ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WEAK COLD FRONT WAS JUST WEST OF THE AREA AS OF 08Z. THE FRONT SHOULD MOVE THROUGH BY DAYBREAK...FOLLOWED BY DOWNSLOPE WNW FLOW THAT ALONG WITH PARTIAL SUNSHINE SHOULD HELP BOOST TEMPS TO 55-60 ACROSS NYC METRO AND MOST OF LONG ISLAND...AND 50-55 TO THE NORTH...SEVERAL DEGREES WARMER THAN A 00Z GFS/NAM MOS GUIDANCE BLEND. THE 06Z RAP SUGGESTS THAT TEMPS COULD EVEN REACH THE LOWER 60S INVOF NYC WITH ENOUGH AFTERNOON SUNSHINE...BUT HAVE DOUBTS AS TO WHETHER IT WILL GET THIS WARM AS MID LEVEL CLOUDS WILL BE INCREASING LATE THIS AFTERNOON AHEAD OF THE APPROACHING STORM. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... CLOUDS WILL LOWER/THICKEN TONIGHT ESPECIALLY NORTH/WEST OF NYC... AHEAD OF LOW PRESSURE DEVELOPING IN THE OH VALLEY. OVERRUNNING LIGHT PRECIP SHOULD ALSO MOVE INTO AREAS MAINLY NORTH/WEST OF NYC AFTER MIDNIGHT. HAVE TRENDED WARMER TONIGHT...WITH LOWS 40-45 INVOF NYC AND 35-40 ELSEWHERE...AND WITH ELEVATED WARM NOSE MOVING IN PRECIP SHOULD START OFF AS RAIN THROUGHOUT. GFS/ECMWF RELATIVELY CLOSE ON DETAILS WED INTO WED NIGHT AS THE INTENSIFYING LOW MOVES OUT OF THE OHIO VALLEY AND PASSES NW OF NYC BY WED EVENING. THE BULK OF THE RAIN ON WED SHOULD BE NORTH OF THE LOW TRACK DURING THE DAYTIME IN THE COOL SECTOR. AS THE SUB-980 MB SFC LOW TRACKS OVER THE AREA JUST NW OF NYC AND THE COAST LATE WED AFTERNOON/EVENING...MOST IF NOT ALL THE CWA COULD GET INTO THE WARM SECTOR...WITH TEMPS RISING INTO THE 50S MAINLY ACROSS NYC METRO...NE NJ AND THE LOWER HUDSON VALLEY WHERE MARINE INFLUENCE WILL BE MINIMAL. A LINE OF FORCED LOW TOPPED CONVECTION IS LIKELY ALONG A TRAILING COLD FRONT...WHICH COULD PRODUCE STRONG WIND GUSTS ESPECIALLY ACROSS NE NJ AND NYC METRO WHERE SFC INSTABILITY LIKELY TO BE SFC-BASED AS BOTH TEMPS/DEWPOINTS RISE INTO THE 50S. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... MUCH COLDER AIR WILL MOVE IN BEHIND THE INTENSE LOW WED NIGHT AS IT DEPARTS TO THE GULF OF MAINE...WITH LOWS 20-25 AND POSSIBLY FALLING TO THE UPPER TEENS WELL INLAND. GIVEN THE MORE NORTHERLY LOW TRACK...HEAVIER PRECIP SHOULD ALSO REMAIN TO THE NORTH...SO LITTLE IF ANY ACCUMULATION EXPECTED LATE WED NIGHT AS PRECIP CHANGES OVER TO LIGHT SNOW OR SCT SNOW SHOWERS. THU AND THU NIGHT WILL BE BLUSTERY AND VERY COLD...WITH TEMPS NOT RISING MUCH IF AT ALL...REACHING THE MID AND UPPER 20S AT BEST. NW WINDS COULD REACH ADVY CRITERIA ESPECIALLY ACROSS NYC METRO AND LONG ISLAND. LOWS THEN EXPECTED TO FALL TO THE SINGLE DIGITS INLAND...TEENS MOST ELSEWHERE...AND LOWER 20S IN NYC. SEE CLIMATE SECTION FOR DETAILS ON RECORD COLD. THIS VERY COLD AIR MASS WILL BE SHORT LIVED...AS DEEP LAYER RIDGING BUILDS ACROSS WITH SW RETURN FLOW AND WAA ON FRI. LOW PRESSURE MOVING THROUGH SOUTHERN CANADA LATE FRI INTO SAT WILL DRAG A TRAILING COLD FRONT THROUGH BY MIDDAY SAT. SOME QUESTION ON THE EXTENT OF PCPN WITH THIS SYSTEM AS VERY DRY AIR INITIALLY IN PLACE WILL BE HARD TO OVERCOME. BETTER FORCING ALSO LOOKS TO BE TO THE NORTH...SO HAVE ONLY MENTIONED SLIGHT CHANCE POP. SUNDAY SHOULD BE DRY. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... WEAK TROF/COLD FRONT MOVES ACROSS THE TERMINALS THE NEXT FEW HOURS...CLEARING THE EASTERNMOST TERMINAL KGON BY 09Z. S-SW WINDS WILL VEER AROUND TO THE W-NW BEHIND THE BOUNDARY. FLOW WILL BE RIGHT AROUND 310 FROM MID MORNING TO MID AFTERNOON AT 7 TO 10 KT...BEFORE BACKING A BIT BY LATE AFT TO THE W. AN OCCASIONAL GUST UP TO 15 KT IS POSSIBLE DURING THE LATE MORNING AND EARLY AFT HOURS. RIDGE AXIS BUILDS INTO THE AREA TUE EVE WITH A LIGHT AND VARIABLE FLOW. VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. THERE IS SOME CONCERN FOR MVFR CIGS DEVELOPING DURING THE 06Z TO 12Z TUE TIME FRAME FOR THE 30H TAFS AHEAD OF AN APPROACHING WARM FRONT. .OUTLOOK FOR 06Z WED THROUGH SAT... .WED-WED NIGHT...SUB-VFR LIKELY IN RA. ESE-SE WINDS AROUND 10 KT GUSTING UP TO AROUND 20 KT LATE WED AFTN-EVE THEN W-NW WINDS AROUND 20 KT GUSTING UP TO 35 KT LATER WED NIGHT. .THU...IMPROVING TO VFR EARLY. NW G30-40KT. .FRI...VFR. .SAT...SUB-VFR POSSIBLE IN SHOWERS. && .MARINE... WINDS STARTING TO BACK SW AND GUST OVER 20 KT AT 44017. SHOULD SEE MINIMAL SCA CONDS FROM THERE ON EAST THIS MORNING...SO SCA REMAINS IN EFFECT ONLY ON THE OCEAN E OF MORICHES INLET. WINDS AND SEAS INCREASE ON WED WITH SOUTHERLY FLOW. SCA CRITERIA ARE LIKELY TO BE REACHED DURING THE SECOND HALF OF THE DAY. WINDS AND SEAS CONTINUE TO INCREASE INTO WEDNESDAY NIGHT...WITH GALES EXPECTED TO DEVELOP. THEREFORE...WENT AHEAD AND ISSUED A WATCH CONSIDERING THE HIGH AMOUNT OF CONFIDENCE IN THE STRENGTHENING WINDS WITH THE DEEPENING LOW PRESSURE MOVING OFF TO THE EAST. GALES THEN LOOK TO END THURSDAY NIGHT...BUT WINDS AND SEAS STILL REMAIN ELEVATED...WITH 5 FT SEAS NOT DIMINISHING ACROSS THE EASTERN OCEAN WATERS UNTIL AT LEAST FRIDAY MORNING. SCA CONDITIONS POSSIBLY RETURN LATE FRIDAY NIGHT INTO SATURDAY WITH ANOTHER APPROACHING SYSTEM OVER THE WEEKEND. && .HYDROLOGY... LOW TRACK AND THEREFORE ASSOCIATED QPF WITH THE MID WEEK STORM HAVE TRENDED NORTHWARD...SO ONLY EXPECT BASIN AVG QPF OF 1/2 TO 1 INCH FOR SOUTHERN CT...THE LOWER HUDSON VALLEY AND INTERIOR NE NJ. LOWER QPF OF 1/4 TO 1/2 INCH EXPECTED FOR NYC METRO AND LONG ISLAND. LOCAL AMTS OF ABOUT 1/2 INCH HIGHER ARE POSSIBLE IN TSTMS. THE BULK OF THIS PRECIP SHOULD BE RAIN. && .CLIMATE... RECORD LOW TEMPS ARE LIKELY TO BE TIED OR BROKEN AT MOST LOCAL CLIMATE SITES THU AND THU NIGHT... TEMPS FOR THU MAR 13... RECORD LOW MAXIMUM FCST NEWARK.........32 IN 1980 32 BRIDGEPORT.....33 IN 1980 28 CENTRAL PARK...27 IN 1896 30 LAGUARDIA......33 IN 1980 31 KENNEDY........33 IN 1980 30 ISLIP..........34 IN 1989 28 TEMPS FOR FRI MAR 14... RECORD LOW MINIMUM FCST NEWARK.........17 IN 1980 17 BRIDGEPORT.....16 IN 1980 13 CENTRAL PARK... 8 IN 1896 19 LAGUARDIA......18 IN 1980 22 KENNEDY........19 IN 1980 18 ISLIP..........17 IN 1989 13 && .EQUIPMENT... THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER. FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION STATEMENT (ALL LOWER CASE): WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR ANZ330-335-338-340-345-350-353-355. SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ350. && $$ SYNOPSIS...GOODMAN/SEARS NEAR TERM...GOODMAN/PICCA SHORT TERM...GOODMAN/PICCA LONG TERM...GOODMAN/PICCA/SEARS AVIATION...JMC/DW MARINE...GOODMAN/PICCA/SEARS HYDROLOGY...GOODMAN CLIMATE...PICCA EQUIPMENT...
AREA FORECAST DISCUSSION
NWS POCATELLO ID
1028 PM MDT MON MAR 10 2014 .UPDATE...SNOW IS TAKING A LITTLE LONGER TO CLEAR THE UPPER SNAKE HIGHLANDS THIS EVENING. LAST MINUTE CHANGES WILL INCLUDE EXTENDING THE CURRENT WARNING OUT UNTIL 3 AM MDT AND CANCELLING THE FLOOD WATCH SINCE EVERYTHING HAS CHANGED OVER TO SNOW. GROUND MAY BE WARM YET AND STREAMS AS WELL. GAGES SHOW SOME INCREASE ON FALLS RIVER NEAR CHESTER BUT IT LOOKS LIKE IT WILL TAKE QUITE A BIT MORE THAN THAT TO CAUSE PROBLEMS. WILL PROBABLY SEE SOME SNOW ON HIGHWAY 30 NEAR SODA SPRINGS IN THE NEXT COUPLE OF HOURS. RS && .PREV DISCUSSION... /ISSUED 633 PM MDT MON MAR 10 2014/ UPDATE...THE BACK OF THE STORM SYSTEM IS PASSING THROUGH THE CENTRAL MOUNTAINS. TEMPERATURES ARE COLLING WITH SNOW LEVEL JUST BEGINNING TO DROP TO AROUND 7700 TO 7900 FEET ELEVATION. HOWEVER...SNOW ACCUMULATION THE REMAINDER OF THE NIGHT WILL BE LIMITED TO AN INCH OR SO. THEREFORE THE WINTER STORM WARNING WAS ALLOWED TO EXPIRE IN THE CENTRAL MOUNTAINS. THE FLOOD WATCH IN THE KETCHUM AND HAILEY AREA WAS ALSO ALLOWED TO EXPIRE. LIMITED WATER RISES WERE OBSERVED ON SMALL STREAMS...ESPECIALLY THE EAST FORK OF THE BIG WOOD RIVER...BUT THIS WAS LESS THE WATER LEVELS OBSERVED A COUPLE OF DAYS AGO AND NO FLOODING HAS BEEN REPORTED. REMOTE GAGES REPORT WATER LEVELS ARE LEVELING OFF. RS PREV DISCUSSION... /ISSUED 115 PM MDT MON MAR 10 2014/ SHORT TERM...TONIGHT THROUGH WEDNESDAY. A STRONG STORM CONTINUES TO SLOWLY PUSH EAST ACROSS THE WEST. AS THE SYSTEM MOVES OVER IDAHO...IT WILL ACTUALLY BEGIN TO DIG MORE SOUTH AND SETTLE OVER SOUTHERN UTAH AND NEVADA BY TOMORROW AFTERNOON. SNOW LEVELS WILL CONTINUE TO FALL AS A COLD FRONT WORKS ACROSS THE AREA...AND FALL TO THE VALLEY FLOORS AREAWIDE BY MORNING. STRONG WINDS WILL CONTINUE IN THE HIGHER ELEVATIONS AND ALSO ACROSS THE SNAKE PLAIN THIS EVENING. WE ARE ALREADY SEEING LOCALIZED GUSTS IN EXCESS OF 60MPH ACROSS THE PLAIN...BUT MOST GUSTS WILL NOT EXCEED 55MPH. THE WIND ADVISORY REMAINS IN EFFECT FOR THE SNAKE PLAIN UNTIL 9PM. HOWEVER...THERE IS SOME INDICATION THAT WE MAY NEED TO EXTEND THAT UNTIL MIDNIGHT AND PERHAPS EXTEND IT INTO THE SOUTHERN HIGHLANDS ESPECIALLY AS THE WINDS SWITCH TO THE NORTHWEST. IN TERMS OF PRECIPITATION...THE PATTERN BECOMES RATHER COMPLEX THIS EVENING. IN TERMS OF THE MOUNTAINS...WE WILL SEE TWO DISTINCT AREAS OF ENHANCED MOISTURE. THE FIRST IS ACROSS THE UPPER SNAKE HIGHLANDS AND SOUTHWARD TOWARD BEAR LAKE. THE OTHER IS IN NORTHWEST FLOW ACROSS CENTRAL MOUNTAINS FROM CHALLIS TO GALENA SUMMIT. THE BIGGER AMOUNTS OVERALL WILL FALL OVER THE EAST. THE THIRD AREA IS A COMBINATION OF CONVERGENCE AND UPSLOPE. BY MORNING...AN AREA OF CONVERGENCE WILL LIE ACROSS THE SNAKE PLAIN NORTH AND EAST OF CRATERS TO POCATELLO LINE. UPSLOPE WILL ENHANCE THIS MOISTURE BAND ACROSS THE BENCHES AND ADJACENT MOUNTAINS FROM NEAR ST. ANTHONY TO AROUND POCATELLO. SNOW LEVELS WILL HOVER AROUND 4500-5000FT SO THESE AREAS WILL SEE AT LEAST MIX DOWN LOW AND ALL SNOW ABOVE THE BENCHES. IN TERMS OF ADDITIONAL PRECIPITATION OVERNIGHT...THE MOUNTAINS WILL SEE 0.10-0.20 INCHES ACROSS THE WEST AND 0.20-0.50 INCHES IN THE EAST. SNOWFALL AMOUNTS WILL BE A TRACE TO 3 INCHES IN THE MOUNTAINS. SOME BLOWING/DRIFTING IS POSSIBLE IN THE MOUNTAINS BUT WILL NOT BE WIDESPREAD IT APPEARS. WE MAY SEE A DUSTING ACROSS THE SNAKE PLAIN ESPECIALLY EAST OF I-15 BUT IT WILL NOT STICK AROUND LONG. IN TERMS OF WINTER AND FLOOD HEADLINES...WE WILL LET ALL WATCHES AND WARNINGS RIDE AND WILL LET THE EVENING SHIFT DECIDE IF ANYTHING NEEDS TO BE EXTENDED. BY TUESDAY AFTERNOON...WE WILL SEE ANY RAIN OR SNOW CONFINED TO AROUND BEAR LAKE AND DRIER AIR AND HIGH PRESSURE BUILDS INTO IDAHO. WE WILL SEE GUSTY NORTH TO NORTHEAST WINDS ACROSS THE ENTIRE AREA. IT WILL BE A BIT COOLER TOMORROW AS WELL. TUESDAY NIGHT AND WEDNESDAY WILL BE VERY DRY. WITH THE DRY AREA MOVING IN...THIS SHOULD ALLOW FOR A VERY CHILLY NIGHT ACROSS THE AREA AND A DECENT WARMUP ON WEDNESDAY. LOWS WILL LIKELY DROP INTO THE SINGLE DIGITS FOR HIGHER VALLEYS AND ISLAND PARK...WITH 10S AND 20S ELSEWHERE. GUIDANCE ACTUALLY POINTS TO EVEN COLDER TEMPERATURES BUT FOR NOW TRENDED ONLY PARTIALLY THAT DIRECTION. HIGHS BOUNCE BACK INTO 40S/LOWS 50S IN THE VALLEYS AND LOW/MID 30S AT RIDGETOP. KEYES LONG TERM...THU NIGHT THROUGH NEXT MON NIGHT. LONGWAVE PATTERN INDICATES A HIGH AMPLITUDE RIDGE TO THE WEST OF IDAHO THAT SLOWLY DE-AMPLIFIES AND SHIFTS TO THE COAST STARTING SAT NIGHT. THERE ARE A COUPLE OF WEAK TROUGHS THAT MOVE DOWN THE BACKSIDE OF THE RIDGE...THE MOST LIKELY ONE TO AFFECT THE FORECAST AREA IS A FRI NIGHT/SAT SHORTWAVE. ZERO TO LITTLE EFFECT IS EXPECTED SOUTH OF POCATELLO...AND ONLY LITTLE EFFECT NORTH OF THIS. THE MAIN FORECAST PROBLEM IS HOW WARM IT WILL GET...WITH THE ECMWF BEING COLDER AND CLOUDIER. HAVE SPLIT THE DIFFERENCE...WHICH GETS LARGE BEYOND THE FRI NIGHT TROUGH. NO REAL SIGNIFICANT WIND WITH TEMPS GENERALLY ABOVE SEASONAL NORMALS. MESSICK AVIATION...WIND HAVING A HARD TIME DEVELOPING...AND SUN VALLEY JUST BELOW FIELD MINIMUMS. LOWEST CIGS EXPECTED WITH FRONTAL PASSAGE DURING THE MID- TO LATE AFTERNOON. FOR ALL AIRDROMES. LOWEST CIGS EXPECTED ARE MARGINAL VFR. HRRR GUIDANCE OF LATE NOW SUGGESTS STRONG WINDS SHORTLY AFTER 11/01Z IN THE KPIH AREA. SHOULDN`T BE MUCH OF A PROBLEM SINCE THEY ARE ALIGNED WITH THE RUNWAY. SKIES SHOULD CLEAR DURING THE LATE EVENING HOURS. MESSICK HYDROLOGY...MODERATE TO HEAVY RAINFALL BELOW 6500 FEET COMBINED WITH MELTING SNOW WILL CREATE AN INCREASED THREAT OF FLOODING FOR SMALL STREAMS AND LOW LYING AREAS IN THE BIG AND LITTLE WOOD RIVER REGION AND THE UPPER SNAKE HIGHLANDS FOR THE NEXT SEVERAL HOURS. THESE AREAS INCLUDE THE CITIES OF KETCHUM...HAILEY... ASHTON AND ST ANTHONY. A FLOOD WATCH REMAINS IN EFFECT FOR THESE AREAS. FLOODING IS NOT EXPECTED FOR THE MAIN STEM RIVERS AT THIS TIME. WYATT && .PIH WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT BELOW 6500 FEET FOR THE IDZ019. WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT ABOVE 7000 FEET FOR THE IDZ019. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
344 AM CDT Tue Mar 11 2014 ...Updated synopsis and short term sections... .SYNOPSIS... ISSUED AT 343 AM CDT TUE MAR 11 2014 Water vapor loop as of 08Z showed an impressive shortwave trough continuing to dig southeastward into Utah. RAP analysis had a 400mb potential vorticity (PV) anomaly extending from the base of the trough near Great Salt Lake northeastward into eastern Washington...suggesting a little more digging before the wave translates eastward. Warmest temperatures in the lower troposphere (850mb) were found across the High Plains of western Kansas into West Texas (+17C at both North Platte and Dodge City; +20C at Amarillo). The 08Z surface analysis showed a deepening surface low centered near the western Nebraska-Kansas state border. Surface winds continued to respond with overnight winds in the 10 to 13 knot range, helping keep temperatures from dropping much. It was still in the lower to mid 40s across much of the southwest and west central Kansas region. Surface cold frontogenesis was noted across northeastern Wyoming into the northern Nebraska Panhandle. && .SHORT TERM...(Today and tonight) ISSUED AT 343 AM CDT TUE MAR 11 2014 Moderate to high impact wind event this afternoon/evening is the main forecast challenge and how to handle this event with headlines (advisory vs. warning). Now that the forecast wind event is within higher resolution short-term models (RAP13, for instance) temporal range, we are gaining a bit higher confidence in the wind forecast. As the surface low moves southeast into central Kansas, it will continue to deepen down to about 995mb while surface anticyclogenesis will ramp up across the northern Rockies and adjacent High Plains. This will induce a very tight pressure gradient across western Kansas by midday...and especially this afternoon. The combined effect of the pressure gradient and the isallobaric wind due to pressure change, will likely lead to sustained winds around 40 mph for areas along and west of Highway 283 corridor...especially in the 22-01Z time frame. Forecast soundings off the NAM12 and RAP13 both show around 35 knots just off the surface around 900mb at Dodge City at 21Z with mixing up to 800-825mb. The winds around 800-850mb will pick up quite a bit as the north wind low level jet strengthens west of the low at this level. For Dodge City, the 00Z forecast soundings support a high wind event (40mph sustained and/or 58mph gusts) with 50 knots shown by both the NAM12 and RAP13 at the top of the mixed layer (which by that point will be due to vigorous cold advection). Based on this information, we will upgrade to a High Wind Warning for US283 corridor (Ness City down to Englewood) west to the Colorado border. Per collaboration with surrounding offices, we will also include areas of blowing dust where the High Wind Warning will be in effect and hit it pretty hard in the NPW product. As far as precipitation goes, the only area expected to see any measurable precipitation will be the I-70 corridor, and will carry around 50 POPs up there. A few tenths of an inch of wet snow may accumulate during the 23-02Z time frame in particular. .LONG TERM...(Wednesday through Monday) ISSUED AT 300 AM CDT TUE MAR 11 2014 Medium range models indicate an upper level shortwave breaking away from a larger scale trough Wednesday as it digs southeast across the Rockies, and developing into a closed off upper level low across the Intermountain West. Meanwhile, a general westerly flow aloft will prevail across the Western High Plains through the end of the week. This will result in dry conditions persisting across western Kansas through Thursday night with insufficient low/mid level moisture present. The closed off upper level low in the Desert Southwest is then expected to open up and push eastward into the South Plains early Friday bringing marginal precip chances to the Texas and Oklahoma panhandles based on the projected track of the shortwave. Cannot rule out a slight chance for light rain across extreme southern portions of southwest and south central Kansas Friday as the upper level system skirts across our southern fringe. Much cooler temperatures are likely Wednesday as arctic air spills southward into western Kansas in wake of a departing cold front. The NAM/GFS/ECMWF show H85 temperatures dropping well below 0C across central and western Kansas initially Tuesday night. A slight rebound to around 0C across central Kansas to near 5C along the Colorado border is expected Wednesday afternoon due to some northwesterly downsloping developing. Expect highs up into the upper 40s(F) to possibly the lower to mid 50s(F) under decreasing cloud cover. A quick bounce back to warmer temperatures will occur Thursday as the arctic high dips further south across Texas while lee side troughing redevelops across eastern Colorado. This will quickly return a southwesterly downslope flow to western Kansas pushing H85 temperatures up into the lower to mid Teens(C) across central and western Kansas. Highs will easily reach the 60s(F) Thursday afternoon with near 70F not out of the question in some locations. Another cold front is projected to push through western Kansas early Friday once again dropping temperatures across the area. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1219 AM CDT TUE MAR 11 2014 South to southwest winds overnight will gradually veer around to the west-northwest by mid-morning. Winds will increase to around 20 to 25 knots sustained by midday and continue to ramp up to 28 to 32 knots sustained late afternoon from the north-northwest as a strong cold front moves in. A few wind gusts will be around 45 knots or higher between 21z Tuesday and 03z Wednesday with some MVFR ceilings also moving in during this time. Up at HYS, light snow will likely bring the flight category down to IFR for a few hours during the early to mid evening hours. Snow accumulations are expected to be minimal at less than an inch. && .PRELIMINARY POINT TEMPS/POPS... DDC 59 27 51 26 / 20 20 0 0 GCK 56 25 50 24 / 20 20 0 0 EHA 63 27 48 28 / 10 10 0 0 LBL 64 26 50 25 / 10 10 0 0 HYS 55 27 50 24 / 40 50 0 0 P28 62 30 52 28 / 10 10 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING from 1 PM CDT /Noon MDT/ this afternoon to 11 PM CDT /10 PM MDT/ this evening FOR KSZ043>045-061>064-074>078- 084>088. WIND ADVISORY from 1 PM this afternoon to 11 PM CDT this evening FOR KSZ030-031-046-065-066-079>081-089-090. && $$ SYNOPSIS...Umscheid SHORT TERM...Umscheid LONG TERM...JJohnson AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EDT TUE MAR 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 509 AM EDT TUE MAR 11 2014 WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL FLOW FROM THE NRN PLAINS THROUGH THE NE CONUS. A SHORTWAVE TROUGH OVER NRN MANITOBA ON THE LEADING EDGE OF VERY COLD ARCTIC AIR IS EXPECTED TO SLIDE TO THE SE AS A RIDGE BUILDS INTO WRN CANADA. ANOTHER SHRTWV OVER SASK IS ALSO EXPECTED TO DIVE TOWARD THE UPPER MS VALLEY AS THE PATTERN AMPLIFIES. AT THE SFC...A COLD FRONT TRAILING LOW PRES OVER QUEBEC EXTENDED THROUGH NRN ONTARIO INTO SRN MANITOBA. TO THE SOUTH...MILD CONDITIONS PREVAILED WITH READINGS REMAINING IN THE UPPER 30S TO AROUND 40 FROM NRN MN AND NRN WI THROUGH UPPER MI. EXTENSIVE MID/HIGH CLOUDS HAVE ALSO LIMITED RADIATIONAL COOLING. TODAY...THE COLD FRONT IS EXPECTED TO MOVE THROUGH LAKE SUPERIOR AND UPPER MICHIGAN THIS MORNING BRINGING AN INITIAL INFLUX OF COLDER AIR. SO...MAX DAYTIME READINGS ARE EXPECTED EARLY WITH TEMPS STEADY OR SLOWLY FALLING DURING THE AFTERNOON. AS LOW LEVEL MOISTURE NORTH OF LAKE SUPERIOR MOVES IN AND 850 MB TEMPS FALL TO AROUND -13C BY 00Z/WED...SOME LIGHT SNOW SHOWERS OR FLURRIES MAY BE POSSIBLE LATE OVER THE NORTH AND WEST PORTIONS OF THE CWA. TONIGHT...AS THE SASK SHRTWV MOVES TOWARD THE AREA MUCH COLDER ARCTIC AIR WILL PUSH INTO THE REGION WITH 925 MB TEMPS DROPPING TO AROUND -21C AND INCREASING WINDS VEERING FROM THE FROM THE NNW TO NE. A PERIOD OF DEEPER MOISTURE ALONG WITH THE LOW LEVEL INSTABILITY WILL FAVOR SOME LES FOR LOCATIONS DOWNWIND OF LAKE SUPERIOR...ESPECIALLY WHERE UPSLOPE FLOW IS MAXIMIZED. THE POSITION OF THE DGZ WILL ALSO BE MOST FAVORABLE FROM 06Z-12Z/WED. SATELLITE IMAGERY FROM MON SHOWED ENOUGH BREAKS IN THE ICE COVER FOR AT LEAST SOME HEAT/MOISTURE FLUX FROM THE LAKE TO SUPPORT LES. SINCE THE ICE WILL STILL SIGNIFICANTLY REDUCE THE LES POTENTIAL...EXPECT SNOWFALL AMOUNTS ONLY IN THE 1 TO 2 INCH RANGE...GREATEST OVER THE HIGHER TERRAIN OF N CNTRL UPPER MI. THE NE WINDS WILL BE LESS FAVORABLE FOR SNOW AT IWD...WITH THE HIGHER CHANCES/AMOUNTS FARTHER TO THE WEST...OR FOR THE KEWEENAW WHERE LOW LEVEL CONV WILL BE MINIMAL. OTHERWISE...THE MUCH COLDER AIR WITH LOWS NEAR ZERO AND WINDS OF 10 TO 20 MPH WILL PRODUCE WIND CHILLS FROM -10 TO -20 LATE TONIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 343 AM EDT TUE MAR 11 2014 HIGH PRESSURE OVER NORTHWEST ONTARIO WILL LEAD TO NORTHEAST LOW LEVEL FLOW OVER THE UPPER GREAT LAKES REGION TO START THE LONG TERM PERIOD. THIS NORTHEAST FLOW WILL BE PRODUCING UPSLOPE SNOW SHOWERS ESPECIALLY IN NORTH CENTRAL UPPER MICHIGAN TONIGHT AND EXPECT THOSE TO CONTINUE INTO WEDNESDAY. ALTHOUGH WINDS HAVE CREATED SOME GAPS IN THE ICE NEAR THE SOUTHERN SHORELINE OF CENTRAL/EASTERN LAKE SUPERIOR...NOT THINKING THAT THERE WILL BE TOO MUCH ASSISTANCE TO THE UPSLOPE SNOW SHOWERS EVEN THOUGH 900MB TEMPS WILL BE AROUND -22C. WITH INVERSION HEIGHTS ONLY AROUND 3-4KFT...WOULDN/T EXPECT THE SNOW SHOWERS TO BE TOO STRONG AND ANY ADDITIONAL ACCUMULATIONS SHOULD BE LIGHT WITH THE CLOUD BEING ABOVE THE DGZ. DID SLOWLY DIMINISH THE SNOW SHOWER CHANCES THROUGH THE DAY AS THE MOISTURE DEPTH BECOMES SHALLOW AND WINDS BACK TO THE NORTH-NORTHWEST. WITH THE MODELS SHOWING THE MOISTURE REMAINING BELOW THE STRENGTHENING INVERSION FROM THE HIGH MOVING OVER THE UPPER GREAT LAKES...WONDERING IF CLOUDS WILL HOLD OVER THE AREA INTO THE AFTERNOON (ESPECIALLY OVER THE NORTH CENTRAL). THE NORTHERLY WINDS AND CLOUDS WILL LEAD TO A VERY COLD DAY ACROSS UPPER MICHIGAN...WITH HIGHS IN THE UPPER SINGLE DIGITS TO MID TEENS. STILL LOOKS TO BE A VERY COLD NIGHT ON WEDNESDAY NIGHT AS THE HIGH SHIFTS SOUTHEAST ACROSS THE CWA. WILL CONTINUE TO SHOW THE COLDEST VALUES OF -10F TO -18F OVER THE EAST HALF OF THE CWA AND THE SINGLE DIGITS BELOW ZERO OVER THE WEST HALF. WOULD EXPECT THE TEMPERATURES TO WARM OVER THE WEST TOWARDS MORNING AS RETURN FLOW DEVELOPS AND MID CLOUDS BEGINNING TO MOVE IN UNDER WAA AHEAD OF THE NEXT CLIPPER SYSTEM. GEM/ECMWF/NAM CONSISTENT ON SOME LIGHT PRECIPITATION MOVING INTO THE WESTERN U.P. WITH THIS WAA ON THURSDAY MORNING. SINCE THERE HAVE BEEN INDICATIONS OF THIS OVER THE LAST COUPLE OF DAYS...WILL TREND VALUES UP TO CHANCES AND THEN DIMINISH THEM AS THEY HEAD EAST OVER THE REST OF THE CWA DURING THE AFTERNOON. WHILE EARLIER RUNS WERE INDICATING A LACK OF ICE CRYSTALS FOR THIS PRECIPITATION...IT NOW APPEARS THAT THERE WILL BE ENOUGH MOISTURE IN THE ICE CRYSTAL AREA TO SUPPORT ALL SNOW. AT THIS POINT...MIGHT SEE UP TO A HALF INCH TOWARDS IRONWOOD AND THEN DIMINISHING AMOUNTS HEADING EAST. BEHIND THIS PRECIPITATION...FOCUS TURNS TO THE LOW CENTERED NEAR LAKE WINNIPEG AT 18Z THURSDAY. THIS LOW WILL TRACK SOUTHEAST THROUGH THE UPPER GREAT LAKES REGION LATE THURSDAY NIGHT INTO FRIDAY. MODELS STILL DIFFERING ON THE SHORTWAVE...WHICH IS NOW WELL OVER THE PACIFIC...WHICH IN-TURN CONTROLS THE TRACK OF THE LOW. GFS HAS CONSISTENTLY BEEN THE FARTHEST NORTH (ALONG WITH RECENT RUNS OF THE UKMET) AND RUNNING THE LOW ALONG THE NORTH SHORE OF LAKE SUPERIOR...WHILE THE ECMWF TRACKS THE LOW ALONG THE SOUTH SHORE. THE GEM HAS BEEN BOUNCING BETWEEN THE TWO OVER THE LAST COUPLE DAYS. ALL IN ALL...THESE DIFFERENCES WON/T HAVE TOO MUCH OF AN AFFECT ON THE LAND CWA PRECIPITATION...SINCE THE WAA PRECIP WILL BE OVER NORTHEAST LAKE SUPERIOR AND ONTARIO THURSDAY NIGHT. UNFORTUNATELY FOR THOSE LOOKING FOR ANOTHER REALLY WARM DAY...IT APPEARS THAT THE WARM AIR ALOFT WILL MOVE THROUGH ON THURSDAY NIGHT AND THEN AREA WILL SEE COLDER AIR MOVING IN THROUGH THE DAY. THUS...EXPECT THE WARMEST TEMPS ON FRIDAY TO BE NEAR LAKE MICHIGAN AND IN THE UPPER 30S TO AROUND 40. WITH THE DIFFERENCES IN THE TRACK OF THE LOW...THERE ARE ALSO DIFFERENCES IN THE ARRIVAL OF THE SECONDARY COLD FRONT AND NORTHERLY WINDS. COULD BE A LITTLE BREEZY OUT OF THE WEST ON FRIDAY BEFORE THIS ARRIVES...WITH WINDS TURNING TO THE NORTHWEST AND EVENTUALLY NORTHERLY ON FRIDAY NIGHT. EXPECT SOME PRECIPITATION ASSOCIATED WITH THIS COLD SURGE AND WITH SOME GAPS STARTING TO SHOW IN THE ICE NEAR THE APOSTLE ISLANDS...THERE COULD EVEN BE SOME LAKE ENHANCED/EFFECT SNOW FRIDAY NIGHT INTO SATURDAY. DIFFICULT TO GO WITH MUCH MORE THAN SLIGHT/CHANCE POPS WITH THE AMOUNT OF ICE COVER AND POTENTIAL CHANGES OVER THE NEXT SEVERAL DAYS...SO WILL FOLLOW A SIMILAR IDEA AS THE PREVIOUS SHIFT. THAT PUTS CHANCES OVER THE FAVORED NORTHWEST AREAS IN THE WEST ON FRIDAY NIGHT AND THEN TRANSITION TO TRADITIONAL NORTHWEST-NORTHERLY WIND AREAS FOR SATURDAY. WITH A HIGH PRESSURE RIDGE NOSING SOUTH FROM ONTARIO ON SATURDAY NIGHT AND SUNDAY...EXPECT DRIER AIR TO MOVE IN AND HAVE DIMINISHED POPS HEADING INTO SUNDAY (EVENTHOUGH 850MB TEMPS REMAIN AROUND -17C). WITH THE COLD TEMPS ALOFT...SHOULD BE 10-20 DEGREES BELOW NORMAL FOR HIGHS THIS WEEKEND. DEPENDING ON HOW QUICKLY SKIES CLEAR OUT ON SATURDAY NIGHT...THERE IS THE POTENTIAL FOR SUB ZERO LOWS OVER MUCH OF THE AREA AND HAVE TRENDED VALUES DOWN A COUPLE DEGREES. THE COLDEST NIGHT WILL BE SUNDAY NIGHT AS THE AREA OF HIGH PRESSURE MOVES OVER THE CWA. SINGLE DIGITS BELOW ZERO SEEMS LIKE A GOOD START AT THIS POINT...BUT WOULDN/T BE SURPRISED TO SEE SOME COLD SPOTS IN THE TEENS BELOW ZERO. THE HIGH IS EXPECTED TO SHIFT EAST ON MONDAY...BUT IT/S INFLUENCE WILL REMAIN AND KEEP THE AREA DRY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 121 AM EDT TUE MAR 11 2014 WITH LLVL DRY AIR IN PLACE AND SOME HI CLDS/STEADY WINDS LIMITING THE DIURNAL FALL OF TEMP...EXPECT VFR CONDITIONS TO DOMINATE AT ALL 3 TAFS SITES THRU SUNRISE. A COLD FRONT WL PASS THRU UPR MI ON TUE MRNG. THE RETURN OF COLDER AND MOISTER LLVL AIR AIDED BY SOME DAYTIME HEATING/DESTABILIZATION SHOULD RESULT IN AN MVFR SC DECK AT ALL 3 LOCATIONS BY TUE AFTN. THE APRCH OF A DISTURBANCE EMBEDDED IN THE NW FLOW ALOFT THIS EVNG MAY BRING SOME SHSN TO THE AREA... ESPECIALLY AT IWD WHICH WL BE CLOSER TO THE TRACK OF THIS SYSTEM. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 509 AM EDT TUE MAR 11 2014 A COLD FRONT WILL MOVE THROUGH THE AREA TODAY WITH NW TO N WINDS INCREASING TO 20 TO 30 KNOTS OVER ERN LAKE SUPERIOR THIS AFTERNOON INTO TONIGHT. WINDS WILL DIMINISH WED INTO WED NIGHT AS HIGH PRES BUILDS OVER THE NRN LAKES. WINDS WILL REMAIN AT OR BELOW 20 KNOTS UNTIL FRIDAY WHEN ANOTHER LOW PRES SYSTEM JUST TO THE NORTH OF LAKE SUPERIOR BRINGS WEST AND NORTHWEST WINDS OF 20 TO 30 KNOTS AS IT MOVES THROUGH THE REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...KC MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
346 AM CDT TUE MAR 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CDT TUE MAR 11 2014 MOST SIGNIFICANT PRECIPITATION OVER THE NEXT 7 DAYS WILL FALL WITHIN THE NEXT 12 HRS OF THIS DISCUSSION AS AN IMPRESSIVE FRONTGENETICALLY DRIVEN BAND OF PRECIP BLOSSOMS ACROSS THE SOUTHERN HALF OF THE CWA THIS MORNING. HIRES MODELS CONTINUE TO BE TOO COOL WITH THE LOW LEVEL THERMAL FIELDS...AND THUS THEIR PTYPE ALGORITHMS ARE LIKELY OVERDOING THE SNOWFALL ACROSS THE REGION DURING THE INITIAL DEVELOPMENT EARLY THIS MORNING. HOWEVER...BUFR FORECAST SOUNDINGS SHOW TREMENDOUS LIFT ALONG THE LOW/MID LEVEL FRONT AS INFERRED FROM THE SHARP WIND SHIFT WITHIN THE H850-700 LAYER. ASIDE FROM THE LOWEST FEW HUNDRED METERS THE ENTIRE SOUNDING IS BELOW FREEZING...SO ANTICIPATING THAT THE RAIN WILL CHANGE OVER TO A RAIN SNOW MIX AROUND 6-7AM...AND THEN QUICKLY OVER TO HEAVY WET SNOW AROUND MID MORNING ACROSS SOUTHERN MN. SNOW RATIOS WILL BE IN THE MID-SINGLE DIGITS...BUT QPF SHOULD EASILY MANAGE AROUND 0.20 TO 0.30 YIELDING SNOWFALL TOTALS OF 1-2 INCHES UNDER THE HEAVIEST BAND OF SNOW. AT THIS POINT THE RAP 11.07 PLACES THIS HEAVY BAND FROM CANBY MN EASTWARD THROUGH THE SOUTHERN METRO...AND THEREFORE ALL THE HIRES MODELS THAT USE THE RAP FOR THEIR INITIAL BOUNDARY CONDITIONS ARE SUBCONSCIOUSLY DRAWN TO THIS CONCLUSION. HOWEVER...THE H850-700MB FGEN...WHICH AS OF EARLY THIS MORNING MATCHES UP NICELY WITH THE ONGOING PRECIP...SHIFTS SOUTHEAST FROM CANBY TO MANKATO AND OWATONNA. BASED ON THAT DIAGNOSTIC TOOL...EXPECT THE PRECIP TO FALL TOWARD THE SOUTHERN SIDE OF THE CURRENT MODEL GENERATED QPF FIELD. AT THIS POINT NOT ANTICIPATING ANY ADVISORY CRITERIA SNOWFALL AMOUNTS...BUT EXPECT HEAVY WET SNOW WITH 1/2 TO 1/4 MI VISIBILITY POSSIBLE AT TIMES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 345 AM CDT TUE MAR 11 2014 LOOKING AHEAD...COLD AIR WILL SURGE SOUTHWARD BEHIND THIS SYSTEM AS IT STRENGTHENS INTO A MAJOR STORM OVER NEW ENGLAND. CLOSER TO HOME TEMPERATURES WILL FALL BELOW FREEZING TONIGHT AND REMAIN THERE UNTIL THURSDAY WHEN THE NEXT SHOT OF LEE-SIDE WARM AIR SPREADS ACROSS THE REGION. THIS WILL BRING TEMPERATURES INTO THE 40S ONCE AGAIN...WITH 50S IN WESTERN MN. THERE IS A CHANCE FOR SOME LIGHT PRECIP AHEAD OF THIS WARM AIR ADVECTION...MAINLY ALONG THE ST CROIX RIVER VALLEY. THIS WARMUP WILL BE SHORT LIVED AS COLD AIR SPREADS SOUTHWARD AND LASTS INTO NEXT WEEK. NO SIGNIFICANT PRECIPITATION IS EXPECTED UNTIL THE NEXT STORM SYSTEM ARRIVES ON TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1045 PM CDT MON MAR 10 2014 A NARROW BAND OF LIGHT RAIN WILL ENTER WEST CENTRAL MN NEAR THE START OF THE TAFS AND WORK ESE INTO THE TWIN CITIES BEFORE DAYBREAK AND INTO KEAU AROUND DAYBREAK. IT STILL LOOKS LIKE KAXN...KSTC AND KRNH ARE GOING TO BE ON THE NORTHERN EDGE OF THE PRECIPITATION SHIELD. KMSP AND KEAU ARE A LITTLE MORE IN LINE TO RECEIVE A FEW HOURS OF RAIN AND SNOW. KRWF REMAINS THE SITE FOR A FEW INCHES OF SNOW ACCUMULATION TUESDAY MORNING AS THE BAND OF PRECIPITATION SINKS INTO SOUTHERN MINNESOTA. CEILINGS ARE EXPECTED TO BECOME MVFR IN THE RAIN/SNOW MIX WITH MVFR OR LOWER VSBY. THE BACK EDGE OF THE PRECIPITATION WILL MOVE SE OF THE TAF SITES EARLY IN THE AFTERNOON WITH CEILINGS FORECAST BACK TO VFR. LIGHT WINDS OVERNIGHT BECOMING N TO NW AT 12-15 KNOTS BY TUESDAY AFTERNOON WITH GUSTS FROM 20 TO 25 KNOTS. WINDS DIMINISHING TUESDAY EVENING. KMSP...LIGHT RAIN STILL EXPECTED TO BEGIN IN THE 09Z-10Z PERIOD AND THEN MIX WITH SNOW AROUND 12Z WITH A PERIOD OF LIGHT SNOW DURING THE MORNING. ACCUMULATIONS WILL BE LIGHT AND LESS THAN AN INCH. IMPROVED CEILINGS TO VFR IN THE WAKE OF THE SNOW FOR TUESDAY AFTERNOON. NORTHWEST WINDS WILL BE ON THE INCREASE AS WELL DURING THE AFTERNOON WITH GUSTS TO AROUND 20 KNOTS. /OUTLOOK FOR KMSP/ WED...VFR. N WIND 8 KTS BCMG W. THU...VFR. SW WIND 5-10 KTS. FRI...VFR. W 10-15 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JRB LONG TERM...JRB AVIATION...RAH
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
339 AM CDT TUE MAR 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 339 AM CDT TUE MAR 11 2014 THE MODEL CONSENSUS SHOWS A STRONG AREA OF 700-500MB FRONTOGENESIS DEVELOPING ACROSS NERN NEB AROUND 18Z TODAY. THIS FGEN IS EXPECTED TO PRODUCE A FAIRLY STRONG BAND OF WET SNOW WITH HOURLY LIQUID RATES OF UP TO 0.10 INCHES. THE NAM RADAR PRODUCT SHOWS THIS BAND SETTING UP FROM AROUND CHAMBERS TO BROKEN BOW AT 21Z WHICH MOVES QUICKLY EAST OF THE FCST AREA BY 00Z. THE NAM HAS BEEN WOBBLING SOMEWHAT BUT THE CONCEPT OF FOLDED THETA E AND DEEP LIFT IN THE DENDRITIC GROWTH ZONE CONTINUES. THE 05Z RAP MODEL SETS IT UP FROM ONEILL TO SUTHERLAND. THE 00Z ECM FOLLOWS THE NAM WHICH MATCHES THE MODEL CONSENSUS. IN GENERAL...THE MODELS ARE CLUSTERING AROUND 0.20 INCHES OF LIQUID FOR THIS EVENT ALONG HIGHWAY 83 BUT THEN SPREAD OUT TO THE EAST AS SOME SIGNAL A WETTER EVENT AND OTHERS DRIER. THE MEDIAN QPF IN CUSTER COUNTY LOOKS TO BE AROUND 0.30 INCHES. GIVEN THE STRONG LIFT DEVELOPING...IT IS EXPECTED THERE WILL BE A PERIOD OF MODERATE TO HEAVY SNOW DEVELOPING LASTING 1 OR 2 HOURS AT THE MOST. THIS IS ABOUT A 6 HOUR PCPN EVENT WHICH EXITS THE FCST AREA BY AROUND 00Z. THERE IS A SHORT PERIOD OF RAIN BEFORE CHANGE OVER TO SNOW IN THE GFS AND NAM MODELS. H700MB TEMPERATURES COOL VERY RAPIDLY BEHIND THE COLD FRONT MARKING THE ONSET OF PCPN AND DEEP LIFT WILL AID THE DYNAMIC COOLING PROCESS. AN 8 TO 1 SNOW WATER RATIO WAS USED UP NORTH DURING THE MORNING HOURS WHICH WAS REDUCED TO 5 TO 1 DURING THE AFTERNOON. TEMPERATURES FALL TO THE LOW TO MID 30S DURING THE HEAVIEST SNOW AND THEN WARM UP ONCE THE SNOW LETS UP OR ENDS. THIS PRODUCED 1 TO 2 INCHES OF WET SNOW. THERE IS NO REASON TO UNDER ESTIMATE A SPRING STORM DURING THE 2ND WEEK OF MARCH AND THE SYSTEM FORECAST TO DEVELOP TODAY IS EXPECTED TO PRODUCE STRONG NORTH WINDS AS THE SFC LOW DEEPENS ACROSS EAST CENTRAL KANSAS. ALL MODELS SHOW 500M AGL WINDS INCREASING TO OVER 30 KT WHICH TRANSLATES TO 30 MPH AT THE SFC. THE NAM...GFS GUIDANCE...HRRR AND RAP MODELS ALL SHOW GUSTS TO NEAR 50 MPH DEVELOPING ACROSS CNTL NEB NORTH OF THE SFC LOW LOCATED ACROSS KS BY NOON TODAY. H850 WINDS INCREASE TO 45 TO 55 KT. THE WIND FORECAST IS A CONSENSUS OF MODEL GUIDANCE OUTPUT AND DETERMINISTIC SOLNS WHICH FOLLOWS THE MIDDLE ROAD. THE GFS AND THE ECM SPREAD THESE STRONGER WINDS FURTHER NORTH AND WEST THAN THE OTHER MODELS. A WEAK DISTURBANCE IS SHOWN BY THE MODELS TO MOVE ACROSS THE FCST AREA TONIGHT. THIS COULD PRODUCE SNOW FLURRIES OR PERHAPS ISOLATED SNOW SHOWER ACTIVITY AS IT TRANSLATES EAST ACROSS THE FCST AREA. LAPSE RATES STEEPEN AND REMAIN MOIST SUPPORTING THIS FORECAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 339 AM CDT TUE MAR 11 2014 THE SYSTEM BRINGING THE SNOW AND WIND TO THE FORECAST AREA TODAY AND TONIGHT WILL MOVE EAST AND BE PAST THE LOCAL AREA BY 12Z WEDNESDAY. THIS WILL PUT NEBRASKA UNDER SUBSIDENT AIR WEDNESDAY AND WITH DRY AIR ADVECTING IN EXPECTING MOSTLY SUNNY SKIES. ALTHOUGH NOT EXPECTING ADVISORY LEVEL WINDS WEDNESDAY...SIGNALS ARE COMING TOGETHER FOR A BREEZY DAY. MODELS ARE SHOWING A SECONDARY PV MAX DROPPING SOUTH ACROSS CENTRAL NEBRASKA THROUGH THE DAY...TO HELP ENHANCE WINDS ALOFT AND WITH STEEP SURFACE TO 700MB LAPSE RATES CONFIDENCE INCREASES ON BREEZY CONDITIONS. SOUNDINGS SHOW THE MIXED LAYER BETWEEN 700MB AND 800MB AND LOOKING AT MAXIMUM WINDS IN THAT LAYER UP TO 35KTS SO DECIDED TO INCREASE WINDS DURING THE DAY. TEMPERATURES ALOFT DON/T CHANGE SIGNIFICANTLY ON WEDNESDAY SO LOOKING AT AN ADIABATIC PROFILE...HIGHS WOULD BE IN THE 40S FOR MOST LOCATIONS. HOWEVER...MODELS HAVE BEEN CONSISTENTLY A BIT COOL FOR TEMPERATURES AND WITH SUNNY SKIES THINK MOST AREAS WILL WARM A BIT MORE THAN THE DETERMINISTIC MODELS ARE INDICATING. DRY WEATHER IS EXPECTED THROUGH FRIDAY NIGHT AS NO SIGNIFICANT SYSTEMS ARE SET TO MOVE ACROSS THE CENTRAL PLAINS. AN UPPER LEVEL LOW WILL STAY FAIRLY STATIONARY OVER THE SOUTHWEST THROUGH FRIDAY...WHILE THE NORTHERN STREAM WILL KEEP NORTHWEST FLOW ACROSS THE AREA. THERE WILL BE AN APPROACHING SHORTWAVE TROUGH ON THURSDAY AS IT WILL BE MOVING OVER THE NORTHERN ROCKIES. THERE IS A BIT OF UNCERTAINTY ON HOW AMPLIFIED THIS SHORTWAVE TROUGH WILL BE...WHICH IMPACTS HOW STRONG THE SURFACE LOW WILL BECOME AND THEN HOW MUCH WARM AIR CAN BE PULLED NORTHWARD. TOOK A MIDDLE OF THE ROAD APPROACH FOR HIGH TEMPERATURES THURSDAY...WITH FORECAST HIGHS IN THE UPPER 50S AND 60S. IF THE SYSTEM BECOMES A BIT STRONGER...TEMPERATURES WILL LIKELY NEED TO BE RAISED FOR THURSDAY. THE COLD FRONT ASSOCIATED WITH THIS UPPER LEVEL SYSTEM WILL PASS ACROSS NEBRASKA THURSDAY AFTERNOON AND EVENING. ALTHOUGH THERE CONTINUES TO BE QUITE A BIT OF DISAGREEMENT IN MODEL SOLUTIONS ON WHERE THE MAIN ENERGY WITH THIS SYSTEM WILL PASS...IT DOES APPEAR FAIRLY CERTAIN THAT IT WILL BE WELL NORTH OF THE FORECAST AREA. WITH THE MAJORITY OF THE MOISTURE ACROSS THE NORTH STAYING NEAR THE LOW CENTER...FOR PRECIPITATION TO OCCUR WOULD NEED A MOISTURE SOURCE FROM THE SOUTH TO GET THIS TO HAPPEN AS THE FRONT MOVES THROUGH. HOWEVER THE UPPER LOW TO THE SOUTHWEST WILL LIKELY PROHIBIT MUCH MOISTURE TRANSPORT INTO THE AREA FROM THE SOUTH. ONE THING THAT DOES LOOK POSSIBLE IS STRONG WINDS THURSDAY NIGHT. WITH THE AREA STAYING IN A LOCATION WITH DRY AIR...WHEN THE AIRMASS BECOMES SUBSIDENT BEHIND THE FRONT...DOWNWARD MOTION WILL BE PROMOTED. ALTHOUGH TIMING IS NIGHT...WHICH ISN/T AS FAVORABLE FOR STRONGER WINDS...WILL NEED TO CONTINUE TO WATCH THIS TIME-FRAME IN THE NEXT FEW DAYS CONCERNING WINDS. THE MODELS REALLY BEGIN TO DIVERGE BEGINNING SATURDAY AS THEY SEEM TO BE HAVING PROBLEMS HANDLING THE SOUTHWEST UPPER LOW. ONE THING THEY DO ALL AGREE ON IS THAT STRONG RIDGING WILL BUILD IN...SOMEWHERE ACROSS THE WESTERN HALF OF THE COUNTRY INTO THE FIRST PART OF NEXT WEEK. DESPITE THE MODEL DIFFERENCES...THEY ALSO ARE INDICATING THE PATTERN ALOFT BECOMING MORE AMPLIFIED AND DIG A SHORTWAVE TROUGH SOUTH ALONG THE LEE-SIDE OF THE ROCKY MOUNTAINS OVER THE WEEKEND. CONTINUE TO HAVE PRECIPITATION CHANCES THROUGH MUCH OF THE WEEKEND...WITH BOTH RAIN AND SNOW LOOKING POSSIBLE. TEMPERATURE PROFILES SHOW PRECIPITATION TYPE AS RAIN ON SATURDAY...THEN SWITCHING TO RAIN/SNOW AND SNOW SATURDAY NIGHT...THEN BACK TO RAIN ON SUNDAY. THIS MAY NOT BE REAL LIKELY...AS THERE WON/T BE THAT GREAT AMOUNT OF TIME WITH RAIN AND SNOW...BUT WITH CONCERN OVER TIMING AND LOCATION OF THE PRECIPITATION...DID NOT HAVE THE CONFIDENCE YET TO NAIL DOWN A PARTICULAR PRECIPITATION TYPE. THE VERY END OF THE FORECAST PERIOD LOOKS INTERESTING...WITH A STRONG COLD FRONT TO PASS MONDAY NIGHT AND TUESDAY. DYNAMICS WITH THIS SYSTEM ARE PRETTY STRONG...WHICH COULD LEAD TO VERY WARM TEMPERATURES MONDAY...THEN CHANCES FOR PRECIPITATION MONDAY NIGHT AND TUESDAY...AND STRONG WINDS TUESDAY. DIDN/T GO TOO WARM WITH TEMPERATURES FOR MONDAY AT THIS TIME AS CONFIDENCE ON FORECASTING THE HIGHS THE DETERMINISTIC MODELS SHOW AT THIS TIME IS QUITE LOW...BUT IT BEARS WATCHING OVER THE COMING DAYS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1220 AM CDT TUE MAR 11 2014 A BANDED AREA OF IFR/LIFR IN SNOW IS EXPECTED TO DEVELOP ACROSS THE NORTH TOWARD 12Z TUESDAY. THIS BAND OF IFR/LIFR IS EXPECTED MOVE SOUTH THROUGH THE FCST AREA DURING THE LATE MORNING AND AFTERNOON WITH FLIGHT CONDITIONS IMPROVING IN THE NORTH DURING THE AFTN. SCATTERED MVFR IS POSSIBLE TUESDAY EVENING AS A WEAK DISTURBANCE MOVES ACROSS THE FCST AREA. ISOLATED FLURRIES MAY ACCOMPANY THE DISTURBANCE AND PRODUCE MVFR CIGS. && .LBF WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 10 AM CDT /9 AM MDT/ THIS MORNING TO 8 PM CDT /7 PM MDT/ THIS EVENING FOR NEZ025>029-036>038-057>059-069>071. && $$ SHORT TERM...CDC LONG TERM...BROOKS AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1247 AM CDT TUE MAR 11 2014 .UPDATE... ISSUED AT 1247 AM CDT TUE MAR 11 2014 THERE IS NO REASON TO UNDER ESTIMATE A SPRING STORM DURING THE 2ND WEEK OF MARCH AND THE SYSTEM FORECAST TO DEVELOP TODAY IS EXPECTED TO PRODUCE STRONG NORTH WINDS AS THE SFC LOW DEEPENS ACROSS EAST CENTRAL KANSAS. ALL MODELS SHOW 500M AGL WINDS INCREASING TO OVER 30 KT WHICH TRANSLATES TO 30 MPH AT THE SFC. THE NAM...GFS GUIDANCE...HRRR AND RAP MODELS ALL SHOW GUSTS TO NEAR 50 MPH DEVELOPING ACROSS CNTL NEB NORTH OF THE SFC LOW LOCATED ACROSS KS BY NOON TODAY. H850 WINDS INCREASE TO 45 TO 55 KT. THE WIND FORECAST IS A CONSENSUS OF MODEL GUIDANCE OUTPUT AND DETERMINISTIC SOLNS WHICH FOLLOWS THE MIDDLE ROAD. THE GFS SPREADS THESE STRONGER WINDS FURTHER NORTH AND WEST THAN THE OTHER MODELS. A WIND ADVISORY IS IN PLACE TODAY FOR PARTS OF SWRN AND SCNTL NEB. UPDATE ISSUED AT 1220 AM CDT TUE MAR 11 2014 A WIND ADVISORY WILL BE ISSUED SHORTLY FOR SCNTL AND SWRN NEB. UPDATE ISSUED AT 636 PM CDT MON MAR 10 2014 THE 18Z RUNS OF THE NAM AND GFS ARE GETTING MORE AGRESSIVE WITH THE FGEN DROPPING INTO NCNTL NEB EARLY TUESDAY. THE GFS IS FARTHER WEST FOCUSING ACROSS NWRN NEB WHILE THE NAM FAVORS PINE RIDGE AND THE WRN SANDHILLS. THE NAM ACTUALLY PRODUCES OVER 1/2 INCH OF QPF IN THAT REGION AS FOLDED THETA E DEVELOPS ALONG WITH DEEP LIFT IN THE SNOW GROWTH ZONE...-12C TO -18C. THE RAIN CHANGES QUICKLY TO SNOW ACROSS THE NORTHWEST DURING THE EARLY MORNING HOURS IN THIS ZONE OF DEEP LIFT. A NEW FORECAST IS OUT WHICH AFFECTS THE AREAS ALONG AND NORTH OF NEBRASKA HIGHWAY 2 WEST OF THEDFORD. THE FORECAST ADDS WEIGHT TO THE GFS AND NAM QPF FORECAST BUT STILL BLENDS THE SREF AND THE DRIER ECM AND GEM RUNS INTO THE FORECAST FOR 2 TO 3 INCHES OF SNOW ACROSS THE NORTH. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 334 PM CDT MON MAR 10 2014 PRIMARY FOCUS IN THE SHORT TERM PERIODS IS TWO FOLD...FIRST BEING PRECIPITATION ASSOCIATED WITH A TROUGH AND ATTENDANT COLD FRONT. THE SECOND IS GUSTY NORTHERLY WINDS ALONG AND BEHIND THE PASSING FRONT. MILD LOWS ARE ANTICIPATED ONCE AGAIN TONIGHT AS DEEPENING LOW PRESSURE ATOP THE WESTERN HIGH PLAINS CONTINUES TO ADVECT H85 TEMPS OF GREATER THAN 15C ACROSS THE REGION AND EFFECTIVELY MIX THE LOWER TROPOSPHERE. LOWS TONIGHT WILL REMAIN ABOVE 0C FOR MOST LOCATIONS. FRONT BARRELS THROUGH THE CENTRAL PLAINS EARLY ON TUESDAY...WITH THE LEADING EDGE SOUTHEAST OF THE FORECAST AREA BY 15Z AT THE LATEST. LATEST GUIDANCE CONTINUES TO INDICATE A SHORT PERIOD OF FAVORABLE MID-LEVEL FRONTOGENESIS WHEN SATURATION IS PRESENT IN THE DGZ. ALSO SHOWN IS A PERIOD OF CONVECTIVE ENHANCEMENT. RAIN CHANGING OVER TO SNOW IS LIKELY OVER MUCH OF THE FORECAST AREA AS THE MIDLEVEL FORCING SLIDES NORTHWEST TO SOUTHEAST THROUGH THE DAY. THE BAND IS SHOWN TO FALL APART ACROSS CENTRAL AND SOUTHEASTERN PORTIONS OF THE CWA THOUGH. FRONTOLYSIS IS SHOWN TO OCCUR AS THE TROUGH BECOMES LESS DEFINED AND UPPER JET DYNAMICS WEAKEN. ALSO PROBLEMATIC TO THE FORECAST IS THE EXPECTED TIMING OF THE CHANGE OVER TO SNOW. THE BRUNT OF THE COLD AIR SIGNIFICANTLY LAGS THE FRONT...AND WITH THE RECENT WARM SPELL...SNOW THAT DOES FALL MAY STRUGGLE TO ACCUMULATE. ATTM...THE FORECAST FAVORS UP TO AN INCH OF SNOW ACROSS OUR NORTHERN ZONES ON GRASSY SURFACES...BUT ACROSS MUCH THE CENTRAL CWA AND POINTS SOUTH...A MIX OF RAIN AND SNOW IS LIKELY...WITH LITTLE TO NO ACCUMULATION. CAA AND DRYING RAPIDLY TAKE HOLD LATE AFTERNOON...PRECIPITATION WILL FOLLOW SUIT...ENDING FROM NORTHWEST TO SOUTHEAST. POSSIBLY OF GREATER CONCERN IS THE PROJECTED WIND ASSOCIATED WITH THIS SYSTEM. ATTM...NUMERICAL GUIDANCE IS AT OR CLOSE TO WIND ADVISORY CRITERIA FOR KBBW...KLBF...AND KIML. DEBATED SERIOUSLY WHETHER OR NOT TO ISSUE A WIND ADVISORY FOR THE SOUTHERN...SOUTHWEST AND FAR SOUTHEASTERN ZONES TO ACCOUNT FOR THE FROPA AND THE APPROACH OF A PV MAX...BUT FOR NOW WILL HOLD OFF AND WAIT FOR THE LATEST GUIDANCE THIS EVENING AS CONFIDENCE WAS NOT YET 100 PERCENT DO TO THE MORNING TIMING OF THE FRONT. THE PRESENCE OF CLOUDS AND COLD AIR ADVECTION THROUGH THE DAY TUESDAY WILL KEEP TEMPERATURES BELOW NORMAL...WITH AN ATYPICAL DIURNAL CURVE. HIGHS ACROSS OUR SOUTHERN ZONES WILL BE REACHED EARLY IN THE DAY. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 343 PM CDT MON MAR 10 2014 AS THE COLD AIRMASS PUSHES INTO THE GULF OF MEXICO THURSDAY...RETURN FLOW FROM THE TEXAS GULF COAST WILL BRING MOISTURE INTO SOUTHERN AND EASTERN NEBRASKA. AT THE SAME TIME...FLOW FROM THE PACIFIC NORTHWEST ACROSS THE ROCKIES WILL BRING DECENT MID LEVEL MOISTURE INTO NORTHERN AND WESTERN NEBRASKA. AS A RESULT OF THIS...THERE WILL BE PRETTY DECENT MOISTURE ACROSS THE CENTRAL AND NORTHERN PLAINS WITH PRECIPITABLE WATER VALUES OF 0.35-0.45 INCH...THOUGH IT IS CONCENTRATED IN THE MID-TROPOSPHERIC LAYERS. A SURFACE FRONT THEN PUNCHES THROUGH NEBRASKA AND STALLS ACROSS KANSAS. THE FRONT THEN LIFTS BACK TO THE NORTHEAST INTO NORTH CENTRAL AND NORTHEAST NEBRASKA. THE STRONGEST UPWARD MOTION IS EXPECTED TO BE IN NORTHERN AND EASTERN NEBRASKA OVER THE STATIONARY FRONT. TEMPERATURES WILL BE VERY WARM IN CENTRAL AND WESTERN NEBRASKA AND MUCH WARMER THAN THEY WILL BE IN NORTHEAST NEBRASKA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1220 AM CDT TUE MAR 11 2014 A BANDED AREA OF IFR/LIFR IN SNOW IS EXPECTED TO DEVELOP ACROSS THE NORTH TOWARD 12Z TUESDAY. THIS BAND OF IFR/LIFR IS EXPECTED MOVE SOUTH THROUGH THE FCST AREA DURING THE LATE MORNING AND AFTERNOON WITH FLIGHT CONDITIONS IMPROVING IN THE NORTH DURING THE AFTN. SCATTERED MVFR IS POSSIBLE TUESDAY EVENING AS A WEAK DISTURBANCE MOVES ACROSS THE FCST AREA. ISOLATED FLURRIES MAY ACCOMPANY THE DISTURBANCE AND PRODUCE MVFR CIGS. && .LBF WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 10 AM CDT /9 AM MDT/ THIS MORNING TO 8 PM CDT /7 PM MDT/ THIS EVENING FOR NEZ025>029-036>038-057>059-069>071. && $$ UPDATE...CDC SHORT TERM...JACOBS LONG TERM...SPRINGER AVIATION...CDC
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
425 AM CDT TUE MAR 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 424 AM CDT TUE MAR 11 2014 COMPLEX FORECAST TODAY AS A BAND OF PRECIPITATION MOVES SOUTHEAST ACROSS THE CWA. AS OF 4 AM THIS BAND IS ALONG AND NORTH OF HIGHWAY 14. THIS MATCHES WELL WITH A STRONG AREA OF MID LEVEL FRONTOGENESIS. DECENT INSTABILITY ABOVE THE FRONT...THUS NOT SURPRISED BY THE HIGH REFLECTIVITY CURRENTLY ON RADAR. BOUNDARY LAYER REMAINS QUITE WARM...AND THUS PRECIPITATION TYPE IS CURRENTLY RAIN. THIS FIRST AREA OF FRONTOGENESIS SHIFTS SOUTH THIS MORNING...BUT ALSO BEGINS TO WEAKEN. THIS OCCURS AS THE MAIN WAVE EJECTS OUT OF THE ROCKIES...WITH THE BEST QG FORCING SOUTH OF THE MISSOURI RIVER. THUS MAKES SENSE THAT WE SEE FRONTOGENESIS INTENSIFY AGAIN SOUTH OF INTERSTATE 90 AS MODELS SHOW. SO EXPECT WE SEE THE MODERATE TO HEAVY BAND ALONG HIGHWAY 14 SLOWLY WEAKEN THIS MORNING AS IT MOVES SOUTH...THEN INTENSIFY AGAIN THIS AFTERNOON SOUTH OF INTERSTATE 90 AS THE FRONT STRENGTHENS AND INTERACTS WITH THE UPPER WAVE. PRETTY LARGE UNCERTAINTY ON HOW MUCH THE BAND WEAKENS THIS MORNING...AND HOW QUICKLY IT INTENSIFIES THIS AFTERNOON. THIS IS IMPORTANT NOT ONLY FOR QPF...BUT ALSO PRECIPITATION TYPE. IF PRECIPITATION STAYS ON THE LIGHTER SIDE...IT WILL LIKELY STAY MAINLY RAIN. ONLY EXPECTING A CHANGEOVER TO SNOW DUE TO DYNAMIC COOLING IN THE HEAVIEST PRECIPITATION. SO IF THIS HEAVIER BAND WEAKENS ENOUGH...OUR SNOW FORECAST COULD BE IN TROUBLE. THE LATEST 06Z NAM AND HRRR AND RAP DO SHOW THIS MORE PRONOUNCED WEAKENING...SO WILL HAVE TO KEEP AN EYE ON THIS. EVEN AS THE BAND INTENSIFIES SOUTH OF INTERSTATE 90 THIS AFTERNOON...BOUNDARY LAYER COULD BE WARM ENOUGH TO KEEP THINGS RAIN...OR JUST A WET NON ACCUMULATING SNOW. SO FOR NOW...WILL KEEP 1 TO 2 INCHES IN THE FORECAST FOR MOST OF THE CWA...BUT WILL NEED TO MONITOR TEMPERATURE TRENDS THROUGH THE DAY. FOLLOWED CLOSE TO THE ARW AND NAM FOR TIMING...WITH THE BAND IMPACTING INTERSTATE 90 MID TO LATE MORNING...AND NORTHWEST IOWA LATE MORNING INTO THE AFTERNOON. SKIES WILL STAY MOSTLY CLOUDY TONIGHT...AND AS A SECONDARY WAVE DROP SOUTH...COULD SEE SOME SCATTERED SNOW SHOWERS DEVELOP AFTER MIDNIGHT. BASED ON LATEST MODEL RUNS DID SHIFT THIS SNOW SHOWER AREA FURTHER WEST FROM THE PREVIOUS FORECAST...CENTERED MORE BETWEEN THE JAMES RIVER AND INTERSTATE 29 CORRIDOR. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 424 AM CDT TUE MAR 11 2014 FOR THE MEDIUM RANGE...HAVE SIDED CLOSER TO A BLEND OF THE CANADIAN/GFS AND ECMWF. OPTED TO EXCLUDE THE NAM AS IT SEEMED TO BE THE OUTLIER IN TERMS OF THE PROGRESSION OF SYSTEMS AND SEEMED TO BE SLOWER THAN THE OTHER SOLUTIONS. MODELS SUGGEST BAND OF LIGHT SNOW SHOWERS EARLY ON WEDNESDAY THOUGH SATURATION IN THE DENDRITIC LAYER APPEARS TO BE A SIGNIFICANT ISSUE. MODEL SOUNDINGS VARY FROM SOLUTION TO SOLUTION...BUT IN GENERAL...ALL HINT AT ONLY A LIMITED AMOUNT OF THE DENDRITIC LAYER SATURATING AND WITH THE WARMER AIR BEGINNING TO RETURN IT APPEARS AS THOUGH THE CHANCE OF DEVELOPING THROUGHOUT THE MORNING DECREASES WITH TIME. HAVE KEPT LOW CHANCE POPS THROUGH THE EARLY MORNING HOURS...BUT DROPPED TO FLURRIES IN THE LATE MORNING IF ANYTHING IS LEFT BY THEN. EXPECT NICE WARMING WEDNESDAY INTO THURSDAY...HOWEVER STRATUS MAY LINGER AHEAD OF THE WARM FRONT ACROSS THE EASTERN CWA ON WEDNESDAY LIMITING WARMING POTENTIAL. WARMED HIGHS ON THURSDAY WITH CLEAR SKIES AND NICE SOUTHWEST FLOW ALOFT RESULTING IN 925 HPA TEMPS WARMING INTO THE 10-13C RANGE. COLD FRONT MOVES THROUGH THE AREA ON THURSDAY NIGHT. SHORT WAVE MOVES THROUGH MINNESOTA LATE THURSDAY NIGHT INTO FRIDAY. FOR THE MOST PART...IT APPEARS AS THOUGH THE WAVE IS FOCUSED EAST OF THE FORECAST AREA...SO LEFT FORECAST DRY FOR THE TIME BEING. BACK DOOR COLD FRONT MOVES INTO THE UPPER MIDWEST FRIDAY NIGHT. FRONT WORKS BACK TO THE WEST ON SATURDAY...WITH COOL NORTHEAST FLOW EAST OF THE FRONT. A SERIES OF SHORT WAVES APPEAR TO MOVE THROUGH THE AREA ON SATURDAY NEAR THE FRONT...POTENTIALLY CREATING SOME LIGHT RAIN/SNOW DEPENDING WHICH SIDE OF THE FRONT A PARTICULAR LOCATION IS ON. THE FRONT BEGINS TO SHIFT EAST ACROSS THE REGION ON SUNDAY LEADING TO A WARMING TREND. STRONG SOUTHERLY FLOW DEVELOPS ON MONDAY...LEADING A WARM BUT WINDY DAY. INCREASED WINDS ON MONDAY COMPARED TO THE GUIDANCE BUT MAY NOT HAVE INCREASED ENOUGH WITH 20-30 KNOTS OF FLOW THROUGH THE AFTERNOON HOURS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1034 PM CDT MON MAR 10 2014 VFR CONDITIONS ACROSS THE AREA AT THE START OF THE PERIOD WILL DIMINISH INTO MVFR-IFR CATEGORY BY 12Z ALONG THE HIGHWAY 14 CORRIDOR AS A BAND OF RAIN/SNOW DEVELOPS ACROSS THAT AREA. THE BAND OF PRECIP WILL THEN TRACK SOUTH SOUTHEAST ACROSS THE REMINDER OF THE FORECAST AREA THROUGH THE DAY TUESDAY. EXPECT THE LIGHT RAIN TO TRANSITION FAIRLY QUICKLY TO A RAIN AND SNOW MIX THEN TO ENTIRELY SNOW AS THE PRECIPITATION INTENSITY PICKS UP WITH STRONG LIFT ALOFT. MVFR CEILINGS ARE EXPECTED TO BECOME WIDESPREAD WITH THE ARRIVAL OF PRECIPITATION...WITH MVFR-IFR VISIBILITY IN SNOW. PERIODS OF IFR CEILINGS AND LIFR VISIBILITY LIKELY IN HEAVIEST SNOW BANDS...THOUGH LOWEST CONDITIONS ONLY EXPECTED TO LAST FOR 2-3 HOURS AT ANY ONE LOCATION. WINDS WILL ALSO BE ON THE INCREASE FROM THE NORTH DURING THE DAYTIME ON TUESDAY WITH GUSTS CLOSE TO 30 KT LIKELY. THIS COULD CAUSE A LITTLE FURTHER REDUCTION IN VISIBILITY WHILE THE SNOW IS FALLING...BUT BLOWING SNOW IS NOT EXPECTED TO BE AN ISSUE ONCE THE SNOW IS ON THE GROUND DUE TO EXPECTED WET NATURE OF THIS SNOWFALL. IMPROVEMENT BACK INTO VFR CATEGORY EXPECTED INTO FAR NORTHWEST PART OF THE AREA AROUND KHON BY EARLY TUESDAY AFTERNOON...WITH IMPROVING CONDITIONS EXPANDING NORTHWEST TO SOUTHEAST THROUGH THE AFTERNOON AND EARLY EVENING HOURS. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...CHENARD LONG TERM... AVIATION...JH
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
457 AM CDT TUE MAR 11 2014 .UPDATE... EARLY MORNING REGIONAL RADARS SHOWED SOME VERY LIGHT RAINFALL OVER CENTRAL TEXAS...EXTENDING AS FAR NORTH AS A HILLSBORO TO ATHENS LINE. THESE RAIN SHOWERS WERE ORIENTED ON THE NORTHERN PERIPHERY OF A VORTICITY LOBE ASSOCIATED WITH AN UPPER LOW...ROUGHLY CENTERED OVER AUSTIN ACCORDING TO 08Z WATER VAPOR SATELLITE IMAGERY. 08Z SURFACE ANALYSIS SHOWED MILD TEMPERATURES ACROSS NORTH AND CENTRAL TEXAS WITH MOST LOCATIONS HOLDING UP IN THE MID TO UPPER 50S. 08Z OBJECTIVE ANALYSIS SHOWED RELATIVELY STRONG LEE SIDE CYCLOGENESIS OVER THE SOUTHERN HIGH PLAINS WITH 3 HR PRESSURE FALLS OF AROUND 4 MB NEAR AN ELONGATED AREA OF LOW PRESSURE OF 997 MB OVER THE OK AND TX PANHANDLES. TODAY...THE PREVIOUS QUICK AFD WAS APPENDED BELOW. IN GENERAL OVER THE NEXT 24 TO 36 HRS THE REGION IS EXPECTED TO BE AFFECTED BY A DYNAMIC LOW PRESSURE SYSTEM WHICH WILL LEAD TO FIRE WEATHER DANGER AND STRONG WIND CONCERNS FOR NORTH AND CENTRAL TEXAS. THE PRIMARY UPPER LEVEL FEATURE DRIVING THESE CONDITIONS IS A STRONG SHORTWAVE TROUGH OBSERVED OVER UTAH...MOVING EAST-SOUTHEAST PER WATER VAPOR SATELLITE IMAGERY. 00Z UPPER AIR ANALYSIS OBSERVED A STRONG JET STREAK IN EXCESS OF 100 KTS AT THE 250 MB LEVEL AT THE BASE OF THIS TROUGH. THIS JET STREAK WAS LIKELY LOCATED OVER THE CENTRAL AND SOUTHERN CONUS ROCKIES EARLY THIS MORNING...AIDING IN THE STRONG LEE SIDE SURFACE CYCLOGENESIS OBSERVED ACROSS THE OK AND TX PANHANDLES. THE STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE EAST OVER THE CENTRAL PLAINS TODAY...DRIVING THE SURFACE CYCLONE EAST-SOUTHEAST TOWARDS NORTH TX THIS AFTERNOON. OUT AHEAD OF THE FRONT...WINDS ARE EXPECTED TO BECOME BREEZY AND SOUTH-SOUTHWESTERLY AT 15 TO 20 MPH. ALL GUIDANCE INDICATES AN H850 THERMAL RIDGE ORIENTED ALONG AND SOUTH OF THE SURFACE CYCLONE...BUT THE STRENGTH OF THE THERMAL RIDGE VARIES MODEL TO MODEL. HIGHER RESOLUTION MODEL GUIDANCE GENERALLY FAVORS A STRONGER THERMAL RIDGE...SO THE HIGH TEMPERATURE FORECAST FOR TODAY WAS BASED ON THE HIGH END OF THE SPECTRUM OF AVAILABLE GUIDANCE. WENT AHEAD WITH HIGHS JUST ABOVE 90 DEGREES NEAR BRECKENRIDGE AND GRAHAM...AND IN THE MID TO UPPER 80S FOR MOST LOCATIONS ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR. TO THE EAST...HIGHS WILL GENERALLY TOP OUT IN THE LOWER 80S TODAY...A BIT FARTHER REMOVED FROM THE DRIEST AIR AND STRONG THERMAL RIDGE NEAR THE SURFACE LOW. LOOKING AT FIRE WEATHER CONCERNS...ASSUMING HIGHS TOP OUT IN THE MID 80S TO JUST ABOVE 90 DEGREES WEST OF INTERSTATE 35 AS EXPECTED...GRASSY/FINE FUEL TEMPERATURES WILL GET QUITE WARM THIS AFTERNOON. WINDS OF 15 TO 20 MPH COMBINED WITH AFTERNOON RELATIVE HUMIDITY VALUES BELOW 30 PERCENT SUPPORT AT LEAST A HIGH FIRE WEATHER DANGER ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR...AND A GRASS FIRE DANGER STATEMENT HAS BEEN ISSUED FOR THESE LOCATIONS AS A RESULT. CRITICAL TO EXTREME FIRE WEATHER DANGER IS POSSIBLE THIS AFTERNOON...BUT DEPENDENT UP ON THE STRENGTH OF WINDS AND POSITION OF THE DRYLINE. MOST MODEL GUIDANCE KEEPS WINDS BELOW RED FLAG WARNING CRITERIA THIS AFTERNOON OVER THE WESTERN CWA. THIS IS PARTLY BECAUSE MODELS HAVE A PART OF THE ELONGATED SURFACE LOW PRESSURE LOCATED VERY NEAR WICHITA FALLS...GENERALLY REDUCING THE PRESSURE GRADIENT FORCE THAT WOULD OTHERWISE ACCELERATE WINDS THE ADDITIONAL 5 TO 10 MPH NECESSARY TO REACH RED FLAG WARNING CRITERIA. HOWEVER IF THE SURFACE LOW IS A BIT FARTHER NORTH...LIKE THE RAP AND HRRR ADVERTISED AT THE TIME OF THIS DISCUSSION...EXTREME FIRE WEATHER DANGER MAY BE REALIZED THIS AFTERNOON AND A RED FLAG WARNING MAY NEED TO BE ISSUED. THE HRRR IN PARTICULAR SHOWED A STRONG DRYLINE PUNCH INTO THE WESTERN CWA...WITH THE DRYLINE PUSHING AS FAR EAST AS A JACKSBORO TO LAMPASAS LINE BY 21Z. THE HRRR INCREASES WESTERLY WINDS AT THE SURFACE TO 20 TO 25 KTS...OR STRONG ENOUGH FOR CRITICAL/EXTREME FIRE DANGER WITH RELATIVE HUMIDITY VALUES CRASHING INTO THE SINGLE DIGITS WEST OF THE DRYLINE. IF THESE HRRR CONDITIONS ARE REALIZED...A RED FLAG WARNING WOULD CERTAINLY BE WARRANTED BECAUSE ANY GRASS-FIRE IGNITED WOULD BE VERY DIFFICULT...IF NOT IMPOSSIBLE...TO CONTROL. THIS IS DEFINITELY A WORST CASE SCENARIO...AND IS NOT SUPPORTED BY ANY OTHER GUIDANCE AT THIS TIME. REGARDLESS...THIS BEARS WATCHING CLOSELY THROUGHOUT THE DAY AS THE HRRR WAS ALSO THE MOST RECENT GUIDANCE AVAILABLE AT THE TIME OF THIS DISCUSSION. THIS EVENING AND OVERNIGHT...THE SURFACE CYCLONE WILL CONTINUE EAST THIS EVENING...WITH A STRONG COLD FRONT DROPPING SOUTH ACROSS THE REGION IN ITS WAKE. WHILE MODELS DO NOT AGREE ON THE EXACT TIMING OF THE FRONT YET...ALL MODELS AGREE THAT THE FRONT WILL BE VERY FAST MOVING ONCE IT CROSSES THE RED RIVER THIS EVENING. WINDS WILL SHIFT QUICKLY AROUND TO THE NORTH BEHIND THE FRONT...AND PICK UP TO AT LEAST 20 MPH GUSTING ABOVE 30 MPH JUST BEHIND ITS LEADING EDGE. WINDS ARE EXPECTED TO INCREASE IN INTENSITY BY ABOUT 10 MPH OR SO AN HOUR OR TWO BEHIND THE INITIAL FRONTAL PASSAGE. SUSTAINED WINDS OF 30 MPH...GUSTING TO 45 MPH AT TIMES ARE EXPECTED AT PEAK INTENSITY OVERNIGHT. CONFIDENCE IN STRONG WINDS IS VERY HIGH AT THIS TIME AS ALL MODEL GUIDANCE SHOWS AT LEAST A 50 KT JET AT THE 850 MB LEVEL OVER THE CWA BEHIND THE FRONT TONIGHT. HIGHER RESOLUTION GUIDANCE INDICATES 55 TO 60 KT JET FROM 09 TO 12Z OVER THE CWA WELL BEHIND THE FRONT. WENT AHEAD WITH A WIND ADVISORY FOR THE ENTIRE CWA FROM 10 PM THIS EVENING THROUGH 1 PM WEDNESDAY AS THIS APPEARED TO BE THE BEST WINDOW FOR NORTH WINDS EXCEEDING 25 MPH OR GUSTING ABOVE 40 MPH. THE START OR END TIMES OF THIS ADVISORY WILL LIKELY BE ADJUSTED BY LATER SHIFTS AS THE EXACT TIMING OF THE FRONT IS BETTER RESOLVED. WEDNESDAY AND THURSDAY...WEDNESDAY WILL START OFF WITH THE WIND ADVISORY STILL IN EFFECT AS NORTH WINDS HOLD UP AROUND 25 MPH GUSTING TO 40 MPH JUST AFTER SUNRISE...AND THEN SLOWLY DIMINISH TO AROUND 20 MPH JUST AFTER NOON. WEDNESDAY WILL BE MUCH COOLER WITH HIGHS GENERALLY HOLDING IN THE MID 50S WITH STRONG COLD AIR ADVECTION IN PLACE. SKIES ARE EXPECTED TO STAY MOSTLY SUNNY ON WEDNESDAY...WHICH WILL AT LEAST TAKE SOME OF THE BITE OUT OF THE COOL...BREEZY AIR. HOWEVER...WINDS ARE EXPECTED TO BECOME LIGHT AND VARIABLE BY EARLY THURSDAY MORNING...UNDER MOSTLY CLEAR SKIES. THIS WILL BRING MANY LOCATIONS DOWN BELOW FREEZING WEDNESDAY NIGHT...WITH THE EXCEPTION OF URBANIZED AREAS WHICH WILL STAY WARMER DUE TO THE ABSORPTION OF SUNSHINE THROUGHOUT THE DAY ON WEDNESDAY. LIGHT WINDS WILL BECOME SOUTHERLY ON THURSDAY AS TEMPERATURES WARM INTO THE 60S. FRIDAY AND FRIDAY NIGHT...MODELS CONTINUE TO INDICATE A RELATIVELY COMPACT BUT STRONG SHORTWAVE TROUGH WILL MOVE OVER NORTH TEXAS FRIDAY AFTERNOON OR EVENING. BOTH THE GFS AND ECMWF WERE ADVERTISING SOME LIGHT QPF AMOUNTS ASSOCIATED WITH THIS TROUGH WHICH IS DIFFERENT FROM PREVIOUS DAYS. THINK THE QPF AMOUNTS...ALTHOUGH LIGHT...ARE STILL OPTIMISTIC BECAUSE TONIGHT`S FRONT IS EXPECTED TO PLOW SOUTH ALL THE WAY ACROSS THE WESTERN GULF OF MEXICO...EFFECTIVELY STUNTING OUR PRIMARY MECHANISM TO RECHARGE THE LOWER TROPOSPHERE WITH WATER VAPOR. THE SHORTWAVE TROUGH ITSELF IS EXPECTED TO ORIGINATE FROM THE TROUGH THAT SENDS THE STRONG FRONT SOUTH ACROSS THE REGION TONIGHT. IT IS EXPECTED TO BREAK OFF THE MAIN TROUGH AND REMAIN QUASI-STEADY OVER THE SOUTHWESTERN CONUS FOR A COUPLE OF DAYS BEFORE MOVING EAST WITH THE NEXT NORTHERN STREAM SHORTWAVE TROUGH THURSDAY NIGHT INTO FRIDAY. THE ONLY REASON THIS MATTERS AT ALL IS BECAUSE IT IS NOT LIKELY TO BE ASSOCIATED WITH A PLUME OF SOUTHERN PACIFIC MOISTURE...SO THE ORIGIN OF THE RAPID MOISTENING OF THE GFS AND ECMWF OUT AHEAD OF THE TROUGH IS A BIT OF A MYSTERY AT THIS TIME. GRANTED...LIFT ASSOCIATED WITH THE TROUGH IS EXPECTED TO BE STRONG...SO DYNAMIC LIFT...COOLING AND SATURATION FROM THE BOTTOM UP...IS POSSIBLE. WENT AHEAD WITH SOME 20 POPS FRIDAY AFTERNOON AND EVENING ACROSS THE FAR EASTERN CWA DUE TO UNCERTAINTY REGARDING THE SOURCE REGION OF MOISTURE FOR THE GFS AND ECMWF POP/QPF FORECAST. IF MOISTURE IS JUST BEING UNDERESTIMATED IN GENERAL...POPS AND QPF MAY HAVE TO BE BUMPED WEST IN LATER FORECASTS. NEXT WEEKEND...A STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE FROM THE NORTHWEST CONUS SOUTHEAST TOWARDS THE SOUTHERN PLAINS DURING THIS TIME. THE GFS CONTINUES TO BRING THIS TROUGH OVER NORTH TX...OR JUST OFF TO THE SOUTHWEST. IN GENERAL...RESULTING IN A WETTER FORECAST THAN IF THE TROUGH REMAINS TO THE NORTH OF THE CWA. YESTERDAY THE OPERATIONAL GFS HAD ALMOST NO ENSEMBLE SUPPORT FOR THIS SOLUTION...SO IT WAS LARGELY DISCOUNTED. HOWEVER TODAY...ABOUT HALF OF THE GFS ENSEMBLE MEMBERS AGREE WITH THIS SOLUTION...AND THE OPERATIONAL CANADIAN AND ECMWF HAVE SORT OF COME ON BOARD AS WELL. /SORT OF/ IS USED BECAUSE THERE ARE SOME FAIRLY LARGE TIMING AND STRENGTH DISCREPANCIES BETWEEN THESE MODELS. HOWEVER THE FORECAST TRACK OF THE UPPER TROUGH SEEMS TO BE THE MAIN DIFFERENCE DICTATING A WET VERSUS DRY FORECAST...SO IT IS GOOD TO SEE MODELS TRENDING TOWARDS A MORE SOUTHERLY TRACK AT THIS TIME. QPF AMOUNTS ARE NOT VERY HIGH IN ANY OF THESE SOLUTIONS...MOSTLY BECAUSE IN ALL SOLUTIONS THE UPPER TROUGH IS POSITIVELY TILTED UNTIL IT MOVES EAST OF THE SOUTH PLAINS. BUT...BEGGARS CANT BE CHOOSERS...AND WE REALLY NEED SOME RAIN...SO WILL CONTINUE TO WATCH THE EVOLUTION OF THIS WEEKENDS TROUGH CLOSELY IN THE COMING DAYS AND HOPE FOR THE BEST. CAVANAUGH && .PREV DISCUSSION... /ISSUED 328 AM CDT TUE MAR 11 2014/ IN THE SHORT TERM FORECAST THERE ARE TWO PRIMARY CONCERNS: 1. FIRE WEATHER DANGER WEST OF INTERSTATE 35 THIS AFTERNOON. 2. STRONG WINDS BEHIND A COLD FRONT LATE THIS EVENING THROUGH WEDNESDAY MORNING. WITH REGARDS TO FIRE WEATHER DANGER: WILL HOLD OFF ON ISSUING A RED FLAG WARNING AT THIS TIME. FIRE WEATHER DANGER WILL BE HIGH TO VERY HIGH WEST OF INTERSTATE 35 THIS AFTERNOON. CRITICAL OR EXTREME FIRE WEATHER DANGER IS POSSIBLE FOR LOCATIONS GENERALLY ALONG AND WEST OF A JACKSBORO TO LAMPASAS LINE IF WINDS ARE STRONGER THAN FORECAST THIS AFTERNOON. LEVEL OF CONFIDENCE IN HIGH FIRE DANGER IS HIGH. LEVEL OF CONFIDENCE IN EXTREME FIRE WEATHER DANGER IS LOW. WITH REGARDS TO THE STRONG WINDS BEHIND A COLD FRONT TONIGHT. NORTH WINDS OF 25 TO 30 MPH...GUSTING TO 40 TO 45 MPH AT TIMES ARE EXPECTED BEHIND THE COLD FRONT THROUGH SUNRISE. WINDS WILL BEGIN TO DIMINISH IN INTENSITY FROM SUNRISE TO NOON ON WEDNESDAY. THE LEVEL OF CONFIDENCE IN THESE STRONG WINDS IS HIGH...THEREFORE A WIND ADVISORY WILL BE ISSUED FOR THE ENTIRE CWA FROM 10 PM THIS EVENING TO NOON ON WEDNESDAY. A FULL DISCUSSION INCLUDING REASONING AND THE REMAINDER OF THE FORECAST WILL BE ISSUED LATER THIS MORNING. CAVANAUGH && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 85 42 57 36 62 / 5 0 0 0 0 WACO, TX 82 41 58 33 60 / 5 0 0 0 0 PARIS, TX 80 41 54 32 61 / 0 0 0 0 0 DENTON, TX 85 39 57 31 63 / 5 0 0 0 0 MCKINNEY, TX 83 39 56 31 63 / 5 0 0 0 0 DALLAS, TX 84 43 57 38 62 / 5 0 0 0 0 TERRELL, TX 81 42 57 33 60 / 5 0 0 0 0 CORSICANA, TX 81 44 57 35 60 / 10 0 0 0 0 TEMPLE, TX 82 42 59 33 60 / 5 0 0 0 0 MINERAL WELLS, TX 88 38 56 33 62 / 0 0 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 10 PM THIS EVENING TO 1 PM CDT WEDNESDAY FOR TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175. && $$ /
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
403 AM CDT TUE MAR 11 2014 .SHORT TERM... THE STAGE IS SET FOR A EARLY SPRING STRONG WIND/BLOWING DUST AND FIRE WEATHER EVENT TODAY AND TONIGHT. 3 AM SAT IMAGERY AND UPPER-AIR ANALYSIS SHOW A SHARP SHORTWAVE MOVING QUICKLY THROUGH THE INTER-MOUNTAIN WEST. THIS WAVE WILL MOVE ROUGHLY EWD INTO THE CENTRAL PLAINS TODAY...PLACING THE CWA ON THE SRN FLANK OF THE MID-LVL JET MAX WITHIN THE BASE OF THE TROUGH. IN ADDITION...A WEAK SFC TROUGH EXTENDING SWD FROM A LOW IN FAR NE COLO THROUGH THE WRN PANHANDLES INTO ERN NM WILL DEEPEN AND MOVE EAST TODAY. TIGHTENING THE SFC PRESSURE GRADIENT WHILE WINDS SWING AROUND TO THE WEST THEN W-NW. FINALLY...A STRONG COLD FRONT IS MOVING INTO NRN COLO AND WRN NE...THIS FRONT WILL BE THE MAIN DRIVER OF STRONG WINDS THIS EVENING/TONIGHT...MORE ON THAT LATER. WINDS ARE EXPECTED TO PICK UP PRETTY QUICKLY THIS MORNING...THE WEST TEXAS SODAR AT REESE CENTER ALREADY SHOWS 30+ KTS AT 500 FT AGL. WHILE WE DO HAVE SOME SHALLOW MOISTURE IN PLACE ACROSS THE ERN CWA THIS MORNING...UNFORTUNATELY...THIS MOISTURE WILL BE SCOURED OUT QUICKLY AND CRITICAL FIRE WEATHER CONDITIONS COULD DEVELOP BEFORE NOON /SEE DISCUSSION BELOW/. IN GENERAL...WE EXPECT WINDS TO RISE INTO THE 25 TO 35 MPH RANGE ACROSS THE AREA TODAY...SLIGHTLY LOWER IN THE ROLLING PLAINS AND SLIGHTLY MORE ACROSS THE W-SW. THESE WINDS WILL LIKELY REMAIN JUST BELOW ADVISORY LEVELS BUT SHOULD BE SUFFICIENT TO LOFT SOME PATCHY BLOWING DUST. TEMPS WILL BE QUITE WARM FOR MOST OF THE AREA...WITH HIGHS IN THE 80S...PERHAPS PUSHING 90F IN THE SRN ROLLING PLAINS...WHILE CAA COMING IN FROM THE NW SHOULD KEEP TEMPS IN THE 70S ACROSS THE FAR SW TX PANHANDLE AND WRN SPLNS. LATE THIS AFTERNOON...ATTENTION WILL TURN TO THE COLD FRONT WHICH IS EXPECTED TO BE BARRELING SOUTH THROUGH THE PANHANDLES. WHILE GUIDANCE IS IN GOOD AGREEMENT THAT THE FRONT/S PROGRESS WILL BE QUICKER IN THE EAST...LAGGING IN THE WEST...THERE IS STILL A FEW HOURS OF DISAGREEMENT IN THE TIMING OF THE FRONT. WE ARE FAVORING THE HIGH-RES GUIDANCE FROM THE RAP AND THE TTU-WRF...WHICH SHOWS THE FRONT ENTERING CHILDRESS COUNTY AROUND 23 UTC...AND PARMER COUNTY AROUND 00 UTC. BUT OF COURSE THE ACTUAL FROPA COULD VARY A COUPLE HOURS EITHER WAY. AS NOTED PREVIOUSLY...MODELS ARE SHOWING VERY IMPRESSIVE PRESSURE RISES BEHIND THE FRONT THIS EVENING. OBJECTIVE GUIDANCE SUGGESTS THAT WIND SPEEDS COULD REACH HIGH WIND CRITERIA /SUSTAINED SPEED OF AT LEAST 40 MPH AND/OR GUSTS IN EXCESS OF 57 MPH/ ACROSS THE NRN HALF OF THE FA. WE ARE A LITTLE SKEPTICAL THAT WE WILL SEE SUSTAINED HIGH WINDS IN THE LOWER TERRAIN OF THE ROLLING PLAINS...BUT WE ARE PLANNING ON EXTENDING THE HIGH WIND WATCH SOUTH AND EAST ACROSS MUCH OF THE CAPROCK....WITH SOLID ADVISORY-LEVEL WINDS EXPECTED ELSEWHERE. SOMEWHAT INTERESTINGLY...THERE IS A PRONOUNCED WEAKNESS PROGGED IN THE 800-700MB WIND FIELD ACROSS MUCH OF OUR AREA AROUND 0Z. THIS SHOULD NOT HAVE MUCH OF AN IMPACT ON THE OVERALL FCST BUT DEPENDING ON THE TIMING OF THE FRONT...IT COULD LEAD TO A SHORT-DURATION LULL IN GUSTY WINDS BEFORE A BIG INCREASE WITH THE FROPA. AS FOR BLOWING DUST...WE ARE LOOKING FOR A CONCENTRATION OF DIRT AND REDUCTION IN VISIBILITY ALONG AND IMMEDIATELY IN THE WAKE OF THE FRONT...BUT WE DON/T HAVE ANY STRONG INDICATIONS AT THIS TIME THAT VISIBILITIES WILL DROP TO ADVISORY OR DUST STORM LEVELS. THIS IS PARTLY DUE TO THE WIND DIRECTION AND OUR EXPECTATION THAT THE FRONT WILL MOVE THROUGH AFTER PEAK MIXING. IF THE FRONT IS FASTER/STRONGER THAN EXPECTED...THEN DENSE BLOWING DUST MAY BE A GREATER CONCERN. && .LONG TERM... AFTER THE ACTIVE SHORT TERM...THE EXTENDED FORECAST SEEMS RELATIVELY BENIGN BY COMPARISON. GUSTY NORTHERLY WINDS EARLY WEDNESDAY WILL GRADUALLY WEAKEN THROUGH THE DAY AS THE PRESSURE GRADIENT RELAXES AND SURFACE RIDGING SETTLES SQUARELY OVER WEST TEXAS. IT WILL BE CONSIDERABLY COOLER BEHIND THIS EVENINGS FROPA...WITH HIGHS ON WEDNESDAY TOPPING OUT AROUND 10 DEGREES BELOW MID-MARCH AVERAGES. SHORTWAVE RIDGING ALOFT WILL FOLLOW ON THURSDAY WHICH WHEN COUPLED WITH RETURN FLOW ON THE BACK SIDE OF THE DEPARTING SURFACE RIDGE AND RENEWED SURFACE TROUGHING IN THE LEE OF THE ROCKIES WILL MEAN BREEZY SOUTHERLY WINDS WITH TEMPERATURES RECOVERING TO NEAR AVERAGE. ATTENTION WILL THEN TURN WEST TO A CUTOFF UPPER LOW THAT WILL HANG OUT OVER THE GREAT BASIN MID-WEEK. THIS UPPER LOW WILL GET KICKED EASTWARD LATE WEEK AS JET ENERGY MOVES INTO THE PACIFIC NORTHWEST. THERE REMAINS SOME TIMING DIFFERENCES...BUT WHAT IS LEFT OF THE UPPER LOW WILL RACE ACROSS THE SOUTH PLAINS FRIDAY OR FRIDAY NIGHT. UNFORTUNATELY...THIS SYSTEM WILL NOT HAVE MUCH IN THE WAY OF LOW-LEVEL MOISTURE TO WORK WITH...BUT THE GFS AND ECMWF DO CONTINUE TO PAINT POCKETS OF VERY LIGHT QPF SOMEWHERE IN OR NEAR THE CWA. GIVEN THIS SIGNAL...WE WOULD NOT BE SURPRISED TO SEE A FEW SPRINKLES OR LIGHT SHOWERS...BUT THE CHANCE OF MEASURABLE RAIN STILL APPEARS LOW AND WE HAVE MAINTAINED POPS AROUND 10 PERCENT. THE TIMING UNCERTAINTY WITH THE PASSING WAVE DOES ALSO CREATE LOWER CONFIDENCE ON WHEN THE ASSOCIATED FROPA WILL OCCUR. A QUICKER SYSTEM/FRONT COULD MEAN TEMPERATURES A LITTLE COOLER THAN WHAT IS CURRENTLY DEPICTED IN THE FORECAST...THOUGH EITHER WAY THE SYSTEM WILL NOT HAVE MUCH COOL AIR TO WORK WITH. THE FIRST HALF OF THE WEEKEND WILL START OUT ON THE MILD SIDE...WITH HIGHS EXPECTED TO TOP OUT IN THE 60S AND LOWER 70S. HOWEVER...A SHORTWAVE TROUGH IS PROGGED TO DIVE SOUTH-SOUTHEASTWARD TOWARD THE REGION SATURDAY NIGHT. AT A MINIMUM...THIS DISTURBANCE SHOULD HELP DRIVE A DECENT COLD FRONT THROUGH...DROPPING TEMPERATURES BACK BELOW AVERAGE FOR THE SECOND HALF OF THE WEEKEND. LESS CERTAIN IS EXACTLY WHAT LONGITUDE THIS DISTURBANCE PASSES AND THUS WHETHER OR NOT IT CAN BRING A WINDOW FOR PRECIPITATION CHANCES TO THE SOUTH PLAINS. THE MOST RECENT ECMWF HAS TRENDED BACK FURTHER WEST AND WETTER...WHILE THE GFS TRACK IS MORE EASTWARD WHICH WOULD LIKELY BE DRY FOR THE SOUTH PLAINS. WE HAVE MAINTAINED SILENT POPS AROUND 10 PERCENT FOR NOW AND WILL WAIT TO MAKE A MOVE ONE WAY OR THE OTHER UNTIL THE NWP CAN COME INTO BETTER AGREEMENT. REGARDLESS...WARMER AND DRY WEATHER SHOULD KICK OFF EARLY NEXT WEEK AS THE UPPER TROUGH DEPARTS AND SOUTHERLY TO SOUTHWESTERLY SURFACE FLOW REDEVELOPS. && .FIRE WEATHER... LATEST INDICATIONS ARE THAT CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP ACROSS THE ENTIRE SOUTH PLAINS AREA TODAY AND WE WILL EXPAND AND UPGRADE THE WATCH TO A RED FLAG WARNING FOR OUR WHOLE CWA. DESPITE HIGH RH VALUES ACROSS THE EASTERN SOUTH PLAINS AND ROLLING PLAINS EARLY THIS MORNING...VERY DRY AIR WILL SPREAD EAST RESULTING IN RH VALUES DROPPING UNDER 15 PERCENT BY 10 AM FOR MANY AREAS...AND INTO THE SINGLE DIGITS ACROSS THE ENTIRE AREA THIS AFTERNOON. WHILE WIND SPEEDS MAY BE ON THE LOW END OF CRITERIA ACROSS THE ERN ROLLING PLAINS...IT APPEARS THAT WIND SPEEDS AND RH VALUES WILL SUPPORT AN EXTREMELY CRITICAL DANGER FOR MUCH OF THE SOUTHWEST AND SOUTHERN SOUTH PLAINS. WINDS MAY RELAX FOR A PERIOD AROUND 6 TO 7 PM...BUT THE PASSAGE OF A STRONG COLD FRONT IN THE EVENING WILL BRING AN ABRUPT WIND SHIFT TO THE NORTH AND MUCH STRONGER WINDS SPEEDS. ALTHOUGH COOLING TEMPS AND RISING RH VALUES WILL BEGIN TO REDUCE THE FIRE DANGER...WE WILL KEEP THE RED FLAG WARNING GOING THROUGH 9 PM CDT DUE TO THIS STRONG FRONT. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 71 25 52 24 60 / 0 0 0 0 0 TULIA 76 28 54 25 63 / 0 0 0 0 0 PLAINVIEW 77 29 55 26 63 / 0 0 0 0 0 LEVELLAND 78 30 54 26 63 / 0 0 0 0 0 LUBBOCK 80 32 56 28 64 / 0 0 0 0 0 DENVER CITY 80 31 55 25 61 / 0 0 0 0 0 BROWNFIELD 81 33 56 26 63 / 0 0 0 0 0 CHILDRESS 83 34 58 31 65 / 0 0 0 0 0 SPUR 85 35 58 30 65 / 0 0 0 0 0 ASPERMONT 88 36 58 29 65 / 0 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM NOON CDT TODAY THROUGH THIS EVENING FOR THE FOLLOWING ZONES: TXZ021>024-027>031-033>044. HIGH WIND WATCH FROM THIS EVENING THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES: TXZ021>023-027-028. && $$ 33/23
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1058 PM PDT Mon Mar 10 2014 .SYNOPSIS... Rain and snow will be ending overnight Monday. Quieter weather is expected through Thursday. A weak weather front will bring light rain to the area on Friday, with another chance of rain late Sunday into next Monday. && .DISCUSSION... Made some updates to the forecast for this evening into tonight. I trimmed out showers in the Spokane/Coeur d`Alene area and up much of the Northern Panhandle. The surface low has pushed well into Montana with the stratiform precip winding down across much of the Central Panhandle Mountains (although some snow can be expected over Lookout Pass this evening). The Spokane/Coeur d`Alene areas did not see enough warming in the afternoon to achieve our convective temperature; however, areas to the north and west are seeing isolated showers developing. Temperatures are a bit too cold for lightening with these showers, but thermal profiles are more conducive for thunderstorms in the southeast from the Northeast Blue Mtns to the Camas Prairie. Showers and thunderstorms are expected to diminish this evening with skies clearing. /SVH && .AVIATION... 06Z TAFS: Showers across the region are beginning to wind down this evening. Clearing skies will result in fog and low stratus in the mountain valleys. Models are doing a poor job handling the moisture near the surface, so forecast confidence is low with fog/stratus tonight. KGEG, KSFF, KCOE, KPUW and KLWS will all see the potential for some fog tonight with varying vis restrictions from LIFR to MVFR possible. Drier air filtering in from Canada is expected to limit the extent of low clouds, especially across the basin. /SVH && .PREV DISCUSSION... /ISSUED 453 PM PDT Mon Mar 10 2014/ DISCUSSION... Tonight...cold pool and its associated instability located behind a passing cold front all exit to the southeast and east tonight. Small scale triggers rotating around the edges of a small scale low pressure area nested in this same cooler air will act as triggers. Additionally there is an increase in instability due to surface heating allowed by sun breaks across parts of the lowlands between the east side of the Cascades and the Idaho Panhandle. For all these reasons and a number of HRRR model runs depicting just such a scenario the forecast holds onto showers along with very low wet bulb zero heights allowing for a typical spring rain/snow/graupel/soft-hail mix of precipitation for mid-slope down to valley and lowland locations with the expectation that any accumulation associated with most intense convective cells will be on the order of minutes rather than hours if at all. Thunderstorm mention remains southeast third of Washington and southern half of North Idaho into early evening with idea that they will be weak, low topped, single or multicell type with potential to produce heavy rain and small soft hail/collapsed snow and gusty wind. Storm motion should be southeast at about 25-35 mph. /Pelatti Tuesday through next Monday: High pressure builds into the area on Tuesday for drier conditions. We will likely see some late night/morning fog and low clouds in the valleys, but otherwise should be nice weather. A minor weather system clips by to our north on Wednesday evening but we don`t expect much weather from this, other than some perhaps some mountain wind. The next real good chance of precipitation arrives on Friday. This system has a decent moisture tap. But the westerly flow will keep the precipitation largely confined to the Cascades and Panhandle mountains. ECMWF is slightly slower and wetter than the GFS. Snow levels will remain high (6000` south, 5000` north) so there will be little if any impact from this system. Does not look like enough rain to cause any flooding concerns. The weather system on it`s heels looks a little more formidable. This wave has a narrow but well-defined moisture plume associated with it. Initially it looks impressive with heavy rain pointed into Vancouver Island and NW Washington. But as it moves eastward, the GFS model spins up a low along this front well to our south (west of San Francisco). This cuts off the moisture supply and we are left with a dying frontal passage. The ECMWF meanwhile doesn`t show this, and has a more consolidated wet front moving through on Sunday night. Temperatures ahead of this front have the potential to be the warmest of the season so far, nearing 60F in the Spokane area. But it won`t take much change in the timing to render a cooler and wetter day for Sunday than currently forecast. Snow levels will be very high (7000-8000`) so the passes will be all rain. The snow levels lower by Monday morning and continue to lower during the day. RJ && .PRELIMINARY POINT TEMPS/POPS... Spokane 30 48 27 53 32 55 / 10 0 0 0 0 0 Coeur d`Alene 29 47 26 52 30 54 / 10 0 0 0 0 0 Pullman 32 48 28 54 34 55 / 50 0 0 0 0 0 Lewiston 35 54 33 60 36 62 / 40 0 0 0 0 0 Colville 29 53 26 54 27 55 / 20 0 0 0 0 0 Sandpoint 28 45 24 47 28 50 / 10 0 0 0 10 10 Kellogg 30 45 29 49 31 50 / 40 10 0 0 0 0 Moses Lake 32 55 30 57 33 60 / 10 0 0 0 0 0 Wenatchee 32 53 32 55 33 57 / 10 0 0 0 0 0 Omak 28 52 28 53 30 56 / 20 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1102 AM EDT TUE MAR 11 2014 .SYNOPSIS... WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY. STRONG LOW PRESSURE WILL THEN MOVE THROUGH WEDNESDAY INTO WEDNESDAY NIGHT...FOLLOWED BY BUILDING HIGH PRESSURE THURSDAY THROUGH FRIDAY. A COLD FRONT WILL PASS THROUGH ON SATURDAY... WITH HIGH PRESSURE BUILDING IN BRIEFLY ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NO MAJOR CHANGES FOR THIS UPDATE. MORNING 72501 SOUNDING AND TRENDS SUGGEST A DAY OF CHASING TEMPERATURES UP. LATEST LAMP MOS GUIDANCE IS BEHIND THE TEMPERATURE CURVE. A PASSING WEAK COLD FRONT...DOWNSLOPE WNW FLOW ALONG WITH PARTIAL SUNSHINE SHOULD HELP BOOST TEMPS TO 55-60 ACROSS NYC METRO AND MOST OF LONG ISLAND...AND 50-55 TO THE NORTH...SEVERAL DEGREES WARMER THAN A 00Z GFS/NAM MOS GUIDANCE BLEND. THE 06Z RAP SUGGESTS THAT TEMPS COULD EVEN REACH THE LOWER 60S INVOF NYC WITH ENOUGH AFTERNOON SUNSHINE...BUT HAVE DOUBTS AS TO WHETHER IT WILL GET THIS WARM AS MID LEVEL CLOUDS WILL BE INCREASING LATE THIS AFTERNOON AHEAD OF THE APPROACHING STORM. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... CLOUDS WILL LOWER/THICKEN TONIGHT ESPECIALLY NORTH/WEST OF NYC... AHEAD OF LOW PRESSURE DEVELOPING IN THE OH VALLEY. OVERRUNNING LIGHT PCPN SHOULD ALSO MOVE INTO AREAS MAINLY NORTH/WEST OF NYC AFTER MIDNIGHT. HAVE TRENDED WARMER TONIGHT...WITH LOWS 40-45 INVOF NYC AND 35-40 ELSEWHERE...AND WITH ELEVATED WARM NOSE MOVING IN PCPN SHOULD START OFF AS RAIN THROUGHOUT. GFS/ECMWF RELATIVELY CLOSE ON DETAILS WED INTO WED NIGHT AS THE INTENSIFYING LOW MOVES OUT OF THE OHIO VALLEY AND PASSES NW OF NYC BY WED EVENING. THE BULK OF THE RAIN ON WED SHOULD BE NORTH OF THE LOW TRACK DURING THE DAYTIME IN THE COOL SECTOR. AS THE SUB-980 MB SFC LOW TRACKS OVER THE AREA JUST NW OF NYC AND THE COAST LATE WED AFTERNOON/EVENING...MOST IF NOT ALL THE CWA COULD GET INTO THE WARM SECTOR...WITH TEMPS RISING INTO THE 50S MAINLY ACROSS NYC METRO...NE NJ AND THE LOWER HUDSON VALLEY WHERE MARINE INFLUENCE WILL BE MINIMAL. A LINE OF FORCED LOW TOPPED CONVECTION IS LIKELY ALONG A TRAILING COLD FRONT...WHICH COULD PRODUCE STRONG WIND GUSTS ESPECIALLY ACROSS NE NJ AND NYC METRO WHERE SFC INSTABILITY LIKELY TO BE SFC-BASED AS BOTH TEMPS/DEWPOINTS RISE INTO THE 50S. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... MUCH COLDER AIR WILL MOVE IN BEHIND THE INTENSE LOW WED NIGHT AS IT DEPARTS TO THE GULF OF MAINE...WITH LOWS 20-25 AND POSSIBLY FALLING TO THE UPPER TEENS WELL INLAND. GIVEN THE MORE NORTHERLY LOW TRACK...HEAVIER PCPN SHOULD ALSO REMAIN TO THE NORTH...SO LITTLE IF ANY ACCUMULATION EXPECTED LATE WED NIGHT AS PCPN CHANGES OVER TO LIGHT SNOW OR SCT SNOW SHOWERS. THU AND THU NIGHT WILL BE BLUSTERY AND VERY COLD...WITH TEMPS NOT RISING MUCH IF AT ALL...REACHING THE MID AND UPPER 20S AT BEST. NW WINDS COULD REACH ADVY CRITERIA ESPECIALLY ACROSS NYC METRO AND LONG ISLAND. LOWS THEN EXPECTED TO FALL TO THE SINGLE DIGITS INLAND...TEENS MOST ELSEWHERE...AND LOWER 20S IN NYC. SEE CLIMATE SECTION FOR DETAILS ON RECORD COLD. THIS VERY COLD AIR MASS WILL BE SHORT LIVED...AS DEEP LAYER RIDGING BUILDS ACROSS WITH SW RETURN FLOW AND WAA ON FRI. LOW PRESSURE MOVING THROUGH SOUTHERN CANADA LATE FRI INTO SAT WILL DRAG A TRAILING COLD FRONT THROUGH BY MIDDAY SAT. SOME QUESTION ON THE EXTENT OF PCPN WITH THIS SYSTEM AS VERY DRY AIR INITIALLY IN PLACE WILL BE HARD TO OVERCOME. BETTER FORCING ALSO LOOKS TO BE TO THE NORTH...SO HAVE ONLY MENTIONED SLIGHT CHANCE POP. SUNDAY SHOULD BE DRY. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... BEHIND A DEPARTING LOW WELL TO THE NORTH...WEAK HIGH PRESSURE BUILDS IN THROUGH THE DAY. MAINLY VFR WITH EXCEPTION OF MVFR HAZE AT KGON. UNCERTAIN OF WHEN MVFR HAZE DISSIPATE...THINKING THIS WILL BE THIS AFTERNOON. THERE IS SOME CONCERN FOR MVFR CIGS DEVELOPING AFTER 06Z FOR THE 30H TAFS AHEAD OF AN APPROACHING WARM FRONT. CONFIDENCE IS LOW AT THIS TIME. MVFR/IFR CIGS LIKELY TO DEVELOP IN THE 12Z TO 18Z TIME FRAME ALONG WITH SOME LIGHT RAIN. WINDS INITIALLY W-WNW...MOSTLY LEFT OF 310 MAGNETIC. WINDS AROUND 7-12 KTS DECREASE IN SPEED LATER THIS AFTERNOON WHILE BECOMING MORE W-SW. THIS CONTINUES INTO THE EVENING WITH POSSIBLE WIDE VARIATIONS IN DIRECTION AS RIDGE AXIS BUILDS IN. A FAST MOVING STORM SYSTEM APPROACHES FROM THE OHIO VALLEY WED MORNING...SENDING A WARM FRONT TOWARD THE AREA BY DAYBREAK WED. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KEWR FCSTER COMMENTS: POSSIBLE GUSTS UP TO 17 KT FROM MID MORNING THROUGH EARLY AFTERNOON. WINDS COULD BE 30-40 DEGREES LEFT OF FORECAST WIND DIRECTION AT TIMES. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KJFK FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. WINDS COULD BE 30-40 DEGREES LEFT OF FORECAST WIND DIRECTION AT TIMES. POSSIBLE HYBRID SEA BREEZE WITH WINDS BACKING AROUND TO 220-250 THIS AFTERNOON. KLGA FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. WINDS COULD BE 30-40 DEGREES LEFT OF FORECAST WIND DIRECTION AT TIMES. KTEB FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. WINDS COULD BE 30-40 DEGREES LEFT OF FORECAST WIND DIRECTION AT TIMES. KHPN FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. WINDS COULD BE 30-40 DEGREES LEFT OF FORECAST WIND DIRECTION AT TIMES. KISP FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. WINDS COULD BE 30-40 DEGREES LEFT OF FORECAST WIND DIRECTION AT TIMES. POSSIBLE HYBRID SEA BREEZE WITH WINDS BACKING AROUND TO 220-250 THIS AFTERNOON. .OUTLOOK FOR 12Z WED THROUGH SAT... .WED-WED NIGHT...SUB-VFR IN RA. ESE-SE WINDS AROUND 10 KT GUSTING UP TO AROUND 20 KT LATE WED AFTN-EVE THEN W-NW WINDS AROUND 20 KT GUSTING UP TO 35 KT LATER WED NIGHT. .THU...IMPROVING TO VFR EARLY. NW G30-40KT. .FRI...VFR. .SAT...SUB-VFR POSSIBLE IN SHOWERS. && .MARINE... SCA HAS BEEN CANCELLED FOR THE OCEAN E OF MORICHES INLET. WINDS AND SEAS INCREASE ON WED WITH SOUTHERLY FLOW. SCA CRITERIA ARE LIKELY TO BE REACHED DURING THE SECOND HALF OF THE DAY. WINDS AND SEAS CONTINUE TO INCREASE INTO WEDNESDAY NIGHT...WITH GALES EXPECTED TO DEVELOP. THEREFORE...WENT AHEAD AND ISSUED A WATCH CONSIDERING THE HIGH AMOUNT OF CONFIDENCE IN THE STRENGTHENING WINDS WITH THE DEEPENING LOW PRESSURE MOVING OFF TO THE EAST. GALES THEN LOOK TO END THURSDAY NIGHT...BUT WINDS AND SEAS STILL REMAIN ELEVATED...WITH 5 FT SEAS NOT DIMINISHING ACROSS THE EASTERN OCEAN WATERS UNTIL AT LEAST FRIDAY MORNING. SCA CONDITIONS POSSIBLY RETURN LATE FRIDAY NIGHT INTO SATURDAY WITH ANOTHER APPROACHING SYSTEM OVER THE WEEKEND. && .HYDROLOGY... LOW TRACK AND THEREFORE ASSOCIATED QPF WITH THE MID WEEK STORM HAVE TRENDED NORTHWARD...SO ONLY EXPECT BASIN AVG QPF OF 1/2 TO 1 INCH FOR SOUTHERN CT...THE LOWER HUDSON VALLEY AND INTERIOR NE NJ. LOWER QPF OF 1/4 TO 1/2 INCH EXPECTED FOR NYC METRO AND LONG ISLAND. LOCAL AMTS OF ABOUT 1/2 INCH HIGHER ARE POSSIBLE IN TSTMS. THE BULK OF THIS PCPN SHOULD BE RAIN. && .CLIMATE... RECORD LOW TEMPS ARE LIKELY TO BE TIED OR BROKEN AT MOST LOCAL CLIMATE SITES FRIDAY MORNING. RECORD AND FORECAST LOW TEMPS FOR FRIDAY MORNING (MAR 14)... RECORD LOW MINIMUM FCST NEWARK.........17 IN 1980 17 BRIDGEPORT.....16 IN 1980 13 CENTRAL PARK... 8 IN 1896 19 LAGUARDIA......18 IN 1980 22 KENNEDY........19 IN 1980 18 ISLIP..........17 IN 1989 13 && .EQUIPMENT... THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER. FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION STATEMENT (ALL LOWER CASE): WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR ANZ330-335-338-340-345-350-353-355. && $$ SYNOPSIS...GOODMAN/SEARS NEAR TERM...PICCA/TONGUE SHORT TERM...GOODMAN/PICCA LONG TERM...GOODMAN/PICCA/SEARS AVIATION...JM/DW MARINE...PICCA/TONGUE HYDROLOGY...GOODMAN CLIMATE... EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1000 AM EDT TUE MAR 11 2014 .SYNOPSIS... WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY. STRONG LOW PRESSURE WILL THEN MOVE THROUGH WEDNESDAY INTO WEDNESDAY NIGHT...FOLLOWED BY BUILDING HIGH PRESSURE THURSDAY THROUGH FRIDAY. A COLD FRONT WILL PASS THROUGH ON SATURDAY... WITH HIGH PRESSURE BUILDING IN BRIEFLY ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NO MAJOR CHANGES FOR THIS UPDATE. MORNING 72501 SOUNDING AND TRENDS SUGGEST A DAY OF CHASING TEMPERATURES UP. LATEST LAMP MOS GUIDANCE IS BEHIND THE TEMPERATURE CURVE. A PASSING WEAK COLD FRONT...DOWNSLOPE WNW FLOW ALONG WITH PARTIAL SUNSHINE SHOULD HELP BOOST TEMPS TO 55-60 ACROSS NYC METRO AND MOST OF LONG ISLAND...AND 50-55 TO THE NORTH...SEVERAL DEGREES WARMER THAN A 00Z GFS/NAM MOS GUIDANCE BLEND. THE 06Z RAP SUGGESTS THAT TEMPS COULD EVEN REACH THE LOWER 60S INVOF NYC WITH ENOUGH AFTERNOON SUNSHINE...BUT HAVE DOUBTS AS TO WHETHER IT WILL GET THIS WARM AS MID LEVEL CLOUDS WILL BE INCREASING LATE THIS AFTERNOON AHEAD OF THE APPROACHING STORM. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... CLOUDS WILL LOWER/THICKEN TONIGHT ESPECIALLY NORTH/WEST OF NYC... AHEAD OF LOW PRESSURE DEVELOPING IN THE OH VALLEY. OVERRUNNING LIGHT PCPN SHOULD ALSO MOVE INTO AREAS MAINLY NORTH/WEST OF NYC AFTER MIDNIGHT. HAVE TRENDED WARMER TONIGHT...WITH LOWS 40-45 INVOF NYC AND 35-40 ELSEWHERE...AND WITH ELEVATED WARM NOSE MOVING IN PCPN SHOULD START OFF AS RAIN THROUGHOUT. GFS/ECMWF RELATIVELY CLOSE ON DETAILS WED INTO WED NIGHT AS THE INTENSIFYING LOW MOVES OUT OF THE OHIO VALLEY AND PASSES NW OF NYC BY WED EVENING. THE BULK OF THE RAIN ON WED SHOULD BE NORTH OF THE LOW TRACK DURING THE DAYTIME IN THE COOL SECTOR. AS THE SUB-980 MB SFC LOW TRACKS OVER THE AREA JUST NW OF NYC AND THE COAST LATE WED AFTERNOON/EVENING...MOST IF NOT ALL THE CWA COULD GET INTO THE WARM SECTOR...WITH TEMPS RISING INTO THE 50S MAINLY ACROSS NYC METRO...NE NJ AND THE LOWER HUDSON VALLEY WHERE MARINE INFLUENCE WILL BE MINIMAL. A LINE OF FORCED LOW TOPPED CONVECTION IS LIKELY ALONG A TRAILING COLD FRONT...WHICH COULD PRODUCE STRONG WIND GUSTS ESPECIALLY ACROSS NE NJ AND NYC METRO WHERE SFC INSTABILITY LIKELY TO BE SFC-BASED AS BOTH TEMPS/DEWPOINTS RISE INTO THE 50S. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... MUCH COLDER AIR WILL MOVE IN BEHIND THE INTENSE LOW WED NIGHT AS IT DEPARTS TO THE GULF OF MAINE...WITH LOWS 20-25 AND POSSIBLY FALLING TO THE UPPER TEENS WELL INLAND. GIVEN THE MORE NORTHERLY LOW TRACK...HEAVIER PCPN SHOULD ALSO REMAIN TO THE NORTH...SO LITTLE IF ANY ACCUMULATION EXPECTED LATE WED NIGHT AS PCPN CHANGES OVER TO LIGHT SNOW OR SCT SNOW SHOWERS. THU AND THU NIGHT WILL BE BLUSTERY AND VERY COLD...WITH TEMPS NOT RISING MUCH IF AT ALL...REACHING THE MID AND UPPER 20S AT BEST. NW WINDS COULD REACH ADVY CRITERIA ESPECIALLY ACROSS NYC METRO AND LONG ISLAND. LOWS THEN EXPECTED TO FALL TO THE SINGLE DIGITS INLAND...TEENS MOST ELSEWHERE...AND LOWER 20S IN NYC. SEE CLIMATE SECTION FOR DETAILS ON RECORD COLD. THIS VERY COLD AIR MASS WILL BE SHORT LIVED...AS DEEP LAYER RIDGING BUILDS ACROSS WITH SW RETURN FLOW AND WAA ON FRI. LOW PRESSURE MOVING THROUGH SOUTHERN CANADA LATE FRI INTO SAT WILL DRAG A TRAILING COLD FRONT THROUGH BY MIDDAY SAT. SOME QUESTION ON THE EXTENT OF PCPN WITH THIS SYSTEM AS VERY DRY AIR INITIALLY IN PLACE WILL BE HARD TO OVERCOME. BETTER FORCING ALSO LOOKS TO BE TO THE NORTH...SO HAVE ONLY MENTIONED SLIGHT CHANCE POP. SUNDAY SHOULD BE DRY. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... FLOW WILL BE RIGHT AROUND 310 FROM MID MORNING TO MID AFTERNOON AT 7 TO 10 KT...BEFORE BACKING A BIT BY LATE AFT TO 270-290. RIDGE AXIS BUILDS INTO THE AREA THIS EVE WITH A LIGHT AND VARIABLE FLOW. A FAST MOVING STORM SYSTEM APPROACHES FROM THE OHIO VALLEY WED MORNING...SENDING A WARM FRONT TOWARD THE AREA BY DAYBREAK. VFR CONDITIONS ARE FORECAST THROUGH THE NEXT 24H. THERE IS SOME CONCERN FOR MVFR CIGS DEVELOPING AFTER 06Z FOR THE 30H TAFS AHEAD OF AN APPROACHING WARM FRONT. CONFIDENCE IS LOW AT THIS TIME. MVFR/IFR CIGS LIKELY TO DEVELOP IN THE 12Z TO 18Z TIME FRAME ALONG WITH SOME LIGHT RAIN. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KEWR FCSTER COMMENTS: POSSIBLE GUSTS UP TO 17 KT FROM MID MORNING THROUGH EARLY AFTERNOON. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KJFK FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. POSSIBLE HYBRID SEA BREEZE WITH WINDS BACKING AROUND TO 230-250 LATE THIS AFTERNOON. KLGA FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. KTEB FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. KHPN FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. KISP FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. .OUTLOOK FOR 12Z WED THROUGH SAT... .WED-WED NIGHT...SUB-VFR IN RA. ESE-SE WINDS AROUND 10 KT GUSTING UP TO AROUND 20 KT LATE WED AFTN-EVE THEN W-NW WINDS AROUND 20 KT GUSTING UP TO 35 KT LATER WED NIGHT. .THU...IMPROVING TO VFR EARLY. NW G30-40KT. .FRI...VFR. .SAT...SUB-VFR POSSIBLE IN SHOWERS. && .MARINE... SCA HAS BEEN CANCELLED FOR THE OCEAN E OF MORICHES INLET. WINDS AND SEAS INCREASE ON WED WITH SOUTHERLY FLOW. SCA CRITERIA ARE LIKELY TO BE REACHED DURING THE SECOND HALF OF THE DAY. WINDS AND SEAS CONTINUE TO INCREASE INTO WEDNESDAY NIGHT...WITH GALES EXPECTED TO DEVELOP. THEREFORE...WENT AHEAD AND ISSUED A WATCH CONSIDERING THE HIGH AMOUNT OF CONFIDENCE IN THE STRENGTHENING WINDS WITH THE DEEPENING LOW PRESSURE MOVING OFF TO THE EAST. GALES THEN LOOK TO END THURSDAY NIGHT...BUT WINDS AND SEAS STILL REMAIN ELEVATED...WITH 5 FT SEAS NOT DIMINISHING ACROSS THE EASTERN OCEAN WATERS UNTIL AT LEAST FRIDAY MORNING. SCA CONDITIONS POSSIBLY RETURN LATE FRIDAY NIGHT INTO SATURDAY WITH ANOTHER APPROACHING SYSTEM OVER THE WEEKEND. && .HYDROLOGY... LOW TRACK AND THEREFORE ASSOCIATED QPF WITH THE MID WEEK STORM HAVE TRENDED NORTHWARD...SO ONLY EXPECT BASIN AVG QPF OF 1/2 TO 1 INCH FOR SOUTHERN CT...THE LOWER HUDSON VALLEY AND INTERIOR NE NJ. LOWER QPF OF 1/4 TO 1/2 INCH EXPECTED FOR NYC METRO AND LONG ISLAND. LOCAL AMTS OF ABOUT 1/2 INCH HIGHER ARE POSSIBLE IN TSTMS. THE BULK OF THIS PCPN SHOULD BE RAIN. && .CLIMATE... RECORD LOW TEMPS ARE LIKELY TO BE TIED OR BROKEN AT MOST LOCAL CLIMATE SITES FRIDAY MORNING. RECORD AND FORECAST LOW TEMPS FOR FRIDAY MORNING (MAR 14)... RECORD LOW MINIMUM FCST NEWARK.........17 IN 1980 17 BRIDGEPORT.....16 IN 1980 13 CENTRAL PARK... 8 IN 1896 19 LAGUARDIA......18 IN 1980 22 KENNEDY........19 IN 1980 18 ISLIP..........17 IN 1989 13 && .EQUIPMENT... THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER. FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION STATEMENT (ALL LOWER CASE): WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR ANZ330-335-338-340-345-350-353-355. && $$ SYNOPSIS...GOODMAN/SEARS NEAR TERM...PICCA/TONGUE SHORT TERM...GOODMAN/PICCA LONG TERM...GOODMAN/PICCA/SEARS AVIATION...DW MARINE...PICCA/TONGUE HYDROLOGY...GOODMAN CLIMATE... EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
751 AM EDT TUE MAR 11 2014 .SYNOPSIS... WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY. STRONG LOW PRESSURE WILL THEN MOVE THROUGH WEDNESDAY INTO WEDNESDAY NIGHT...FOLLOWED BY BUILDING HIGH PRESSURE THURSDAY THROUGH FRIDAY. A COLD FRONT WILL PASS THROUGH ON SATURDAY... WITH HIGH PRESSURE BUILDING IN BRIEFLY ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NO MAJOR CHANGES FOR THIS UPDATE. BUMPED HOURLY TEMPS/MAX T UP A FEW DEGREES THOUGH TO ACCOUNT FOR OBSERVATIONAL AND HI-RES GUIDANCE TRENDS SHOWING BETTER WARMING TODAY. BEHIND A PASSING WEAK COLD FRONT...DOWNSLOPE WNW FLOW ALONG WITH PARTIAL SUNSHINE SHOULD HELP BOOST TEMPS TO 55-60 ACROSS NYC METRO AND MOST OF LONG ISLAND...AND 50-55 TO THE NORTH...SEVERAL DEGREES WARMER THAN A 00Z GFS/NAM MOS GUIDANCE BLEND. THE 06Z RAP SUGGESTS THAT TEMPS COULD EVEN REACH THE LOWER 60S INVOF NYC WITH ENOUGH AFTERNOON SUNSHINE...BUT HAVE DOUBTS AS TO WHETHER IT WILL GET THIS WARM AS MID LEVEL CLOUDS WILL BE INCREASING LATE THIS AFTERNOON AHEAD OF THE APPROACHING STORM. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... CLOUDS WILL LOWER/THICKEN TONIGHT ESPECIALLY NORTH/WEST OF NYC... AHEAD OF LOW PRESSURE DEVELOPING IN THE OH VALLEY. OVERRUNNING LIGHT PRECIP SHOULD ALSO MOVE INTO AREAS MAINLY NORTH/WEST OF NYC AFTER MIDNIGHT. HAVE TRENDED WARMER TONIGHT...WITH LOWS 40-45 INVOF NYC AND 35-40 ELSEWHERE...AND WITH ELEVATED WARM NOSE MOVING IN PRECIP SHOULD START OFF AS RAIN THROUGHOUT. GFS/ECMWF RELATIVELY CLOSE ON DETAILS WED INTO WED NIGHT AS THE INTENSIFYING LOW MOVES OUT OF THE OHIO VALLEY AND PASSES NW OF NYC BY WED EVENING. THE BULK OF THE RAIN ON WED SHOULD BE NORTH OF THE LOW TRACK DURING THE DAYTIME IN THE COOL SECTOR. AS THE SUB-980 MB SFC LOW TRACKS OVER THE AREA JUST NW OF NYC AND THE COAST LATE WED AFTERNOON/EVENING...MOST IF NOT ALL THE CWA COULD GET INTO THE WARM SECTOR...WITH TEMPS RISING INTO THE 50S MAINLY ACROSS NYC METRO...NE NJ AND THE LOWER HUDSON VALLEY WHERE MARINE INFLUENCE WILL BE MINIMAL. A LINE OF FORCED LOW TOPPED CONVECTION IS LIKELY ALONG A TRAILING COLD FRONT...WHICH COULD PRODUCE STRONG WIND GUSTS ESPECIALLY ACROSS NE NJ AND NYC METRO WHERE SFC INSTABILITY LIKELY TO BE SFC-BASED AS BOTH TEMPS/DEWPOINTS RISE INTO THE 50S. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... MUCH COLDER AIR WILL MOVE IN BEHIND THE INTENSE LOW WED NIGHT AS IT DEPARTS TO THE GULF OF MAINE...WITH LOWS 20-25 AND POSSIBLY FALLING TO THE UPPER TEENS WELL INLAND. GIVEN THE MORE NORTHERLY LOW TRACK...HEAVIER PRECIP SHOULD ALSO REMAIN TO THE NORTH...SO LITTLE IF ANY ACCUMULATION EXPECTED LATE WED NIGHT AS PRECIP CHANGES OVER TO LIGHT SNOW OR SCT SNOW SHOWERS. THU AND THU NIGHT WILL BE BLUSTERY AND VERY COLD...WITH TEMPS NOT RISING MUCH IF AT ALL...REACHING THE MID AND UPPER 20S AT BEST. NW WINDS COULD REACH ADVY CRITERIA ESPECIALLY ACROSS NYC METRO AND LONG ISLAND. LOWS THEN EXPECTED TO FALL TO THE SINGLE DIGITS INLAND...TEENS MOST ELSEWHERE...AND LOWER 20S IN NYC. SEE CLIMATE SECTION FOR DETAILS ON RECORD COLD. THIS VERY COLD AIR MASS WILL BE SHORT LIVED...AS DEEP LAYER RIDGING BUILDS ACROSS WITH SW RETURN FLOW AND WAA ON FRI. LOW PRESSURE MOVING THROUGH SOUTHERN CANADA LATE FRI INTO SAT WILL DRAG A TRAILING COLD FRONT THROUGH BY MIDDAY SAT. SOME QUESTION ON THE EXTENT OF PCPN WITH THIS SYSTEM AS VERY DRY AIR INITIALLY IN PLACE WILL BE HARD TO OVERCOME. BETTER FORCING ALSO LOOKS TO BE TO THE NORTH...SO HAVE ONLY MENTIONED SLIGHT CHANCE POP. SUNDAY SHOULD BE DRY. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... FLOW WILL BE RIGHT AROUND 310 FROM MID MORNING TO MID AFTERNOON AT 7 TO 10 KT...BEFORE BACKING A BIT BY LATE AFT TO 270-290. RIDGE AXIS BUILDS INTO THE AREA THIS EVE WITH A LIGHT AND VARIABLE FLOW. A FAST MOVING STORM SYSTEM APPROACHES FROM THE OHIO VALLEY WED MORNING...SENDING A WARM FRONT TOWARD THE AREA BY DAYBREAK. VFR CONDITIONS ARE FORECAST THROUGH THE NEXT 24H. THERE IS SOME CONCERN FOR MVFR CIGS DEVELOPING AFTER 06Z FOR THE 30H TAFS AHEAD OF AN APPROACHING WARM FRONT. CONFIDENCE IS LOW AT THIS TIME. MVFR/IFR CIGS LIKELY TO DEVELOP IN THE 12Z TO 18Z TIME FRAME ALONG WITH SOME LIGHT RAIN. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KEWR FCSTER COMMENTS: POSSIBLE GUSTS UP TO 17 KT FROM MID MORNING THROUGH EARLY AFTERNOON. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KJFK FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. POSSIBLE HYRID SEABREEZE WITH WINDS BACKING AROUND TO 230-250 LATE THIS AFTERNOON. KLGA FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. KTEB FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. KHPN FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. KISP FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID MORNING THROUGH EARLY THIS AFTERNOON. .OUTLOOK FOR 12Z WED THROUGH SAT... .WED-WED NIGHT...SUB-VFR IN RA. ESE-SE WINDS AROUND 10 KT GUSTING UP TO AROUND 20 KT LATE WED AFTN-EVE THEN W-NW WINDS AROUND 20 KT GUSTING UP TO 35 KT LATER WED NIGHT. .THU...IMPROVING TO VFR EARLY. NW G30-40KT. .FRI...VFR. .SAT...SUB-VFR POSSIBLE IN SHOWERS. && .MARINE... WINDS STARTING TO BACK SW AND GUST OVER 20 KT AT 44017. SHOULD SEE MINIMAL SCA CONDS FROM THERE ON EAST THIS MORNING...SO SCA REMAINS IN EFFECT ONLY ON THE OCEAN E OF MORICHES INLET. WINDS AND SEAS INCREASE ON WED WITH SOUTHERLY FLOW. SCA CRITERIA ARE LIKELY TO BE REACHED DURING THE SECOND HALF OF THE DAY. WINDS AND SEAS CONTINUE TO INCREASE INTO WEDNESDAY NIGHT...WITH GALES EXPECTED TO DEVELOP. THEREFORE...WENT AHEAD AND ISSUED A WATCH CONSIDERING THE HIGH AMOUNT OF CONFIDENCE IN THE STRENGTHENING WINDS WITH THE DEEPENING LOW PRESSURE MOVING OFF TO THE EAST. GALES THEN LOOK TO END THURSDAY NIGHT...BUT WINDS AND SEAS STILL REMAIN ELEVATED...WITH 5 FT SEAS NOT DIMINISHING ACROSS THE EASTERN OCEAN WATERS UNTIL AT LEAST FRIDAY MORNING. SCA CONDITIONS POSSIBLY RETURN LATE FRIDAY NIGHT INTO SATURDAY WITH ANOTHER APPROACHING SYSTEM OVER THE WEEKEND. && .HYDROLOGY... LOW TRACK AND THEREFORE ASSOCIATED QPF WITH THE MID WEEK STORM HAVE TRENDED NORTHWARD...SO ONLY EXPECT BASIN AVG QPF OF 1/2 TO 1 INCH FOR SOUTHERN CT...THE LOWER HUDSON VALLEY AND INTERIOR NE NJ. LOWER QPF OF 1/4 TO 1/2 INCH EXPECTED FOR NYC METRO AND LONG ISLAND. LOCAL AMTS OF ABOUT 1/2 INCH HIGHER ARE POSSIBLE IN TSTMS. THE BULK OF THIS PRECIP SHOULD BE RAIN. && .CLIMATE... RECORD LOW TEMPS ARE LIKELY TO BE TIED OR BROKEN AT MOST LOCAL CLIMATE SITES FRIDAY MORNING. RECORD AND FORECAST LOW TEMPS FOR FRIDAY MORNING (MAR 14)... RECORD LOW MINIMUM FCST NEWARK.........17 IN 1980 17 BRIDGEPORT.....16 IN 1980 13 CENTRAL PARK... 8 IN 1896 19 LAGUARDIA......18 IN 1980 22 KENNEDY........19 IN 1980 18 ISLIP..........17 IN 1989 13 && .EQUIPMENT... THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER. FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION STATEMENT (ALL LOWER CASE): WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR ANZ330-335-338-340-345-350-353-355. SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ350. && $$ SYNOPSIS...GOODMAN/SEARS NEAR TERM...GOODMAN/PICCA SHORT TERM...GOODMAN/PICCA LONG TERM...GOODMAN/PICCA/SEARS AVIATION...DW MARINE...GOODMAN/PICCA/SEARS HYDROLOGY...GOODMAN CLIMATE...PICCA EQUIPMENT...//
AREA FORECAST DISCUSSION
NWS POCATELLO ID
930 AM MDT TUE MAR 11 2014 .UPDATE...UPPER TROUGH DROPPING SOUTH ACROSS EAST IDAHO TODAY. AREA WEB CAMS STILL SHOW LIGHT SNOWS MOVING MAINLY THROUGH EASTERN HIGHLANDS IN LINE WITH EARLY NAM. NAM AND HRRR SWING REMNANT MOISTURE THROUGH THE SNAKE PLAIN SOUTHWEST INTO THE EASTERN MAGIC VALLEY AND SOUTHERN HIGHLANDS THIS AFTERNOON...PAINTING LIGHT QPF ACROSS THE REGION. LOCAL WRF AND GFS ALSO PAINT BAND OF MID LEVEL MOISTURE ACROSS THE REGION...WHICH COULD BE ENOUGH TO INITIATE PRECIPITATION WITH EMBEDDED STRATUS CURRENTLY IN PLACE. WILL LEAVE THE WEAK ISOLATED POPS IN PLACE ALONG AND SOUTH OF INTERSTATE CORRIDOR THROUGH SNAKE PLAIN. HIGHER POPS WILL STAY IN PLACE OVER SOUTHERN HIGHLANDS WHERE FAVORABLE UPSLOPE CONDITIONS WILL BE IN PLACE THIS AFTERNOON AS SURFACE TROUGH SLIDES SOUTH AND GRADIENT TURNS MORE NORTHERLY. FOR NOW...NO UPDATES TO CURRENT FORECAST. DMH && .PREV DISCUSSION... /ISSUED 258 AM MDT TUE MAR 11 2014/ SHORT TERM...TODAY THROUGH THURSDAY. SNOW SHOWERS REMAIN MAINLY IN THE EASTERN AND SOUTHERN HIGHLANDS THIS MORNING AS THE UPPER TROUGH MOVES EAST. A QUICK LOOK AT WEBCAMS IS SHOWING THAT AREAS ALONG THE DIVIDE UNDER A WINTER STORM WARNING ARE BEGINNING TO CLEAR UP AND THE THREAT OF BLOWING AND DRIFTING SNOW IS DIMINISHING. THEREFORE...WILL BE ALLOWING THE WINTER STORM WARNING TO EXPIRE WITH THIS MORNINGS FORECAST. STILL EXPECTING THINGS TO GRADUALLY TAPER OFF WITH LINGERING SHOWERS IN THE EXTREME SE CORNER OF IDAHO THIS AFTERNOON. ALL AREAS ARE EXPECTED TO DRY OUT BY THIS EVENING. AS THE WEEK WEARS ON...SE ID WEATHER WILL BE DOMINATED BY A DRIER NW FLOW AS A RIDGE DEVELOPS OVER THE EASTERN PACIFIC. MODELS SHOWING A SHORTWAVE PASSING ALONG THE DIVIDE ON THURSDAY BUT AT THE MOMENT IT LOOKS TO BE RELATIVELY DRY SO AS OF NOW...JUST EXPECTING SOME PASSING CLOUDS. OTHERWISE...TEMPERATURES EXPECTED TO GRADUALLY WARM A FEW DEGREES EACH DAY WITH VALLEY HIGHS IN THE 50S. EP LONG TERM...FRIDAY THROUGH TUESDAY. THE GFS/ECMWF ARE FAIRLY CONSISTENT WITH THE IDEA THAT A FLAT UPPER RIDGE WILL REMAIN POSITIONED OVER THE COAST AS A FEW PAC STORM SYSTEMS BREAK OVER THE RIDGE AXIS INTO THE NRN ROCKIES. THE FIRST IS EXPECTED TO ADVANCE THROUGH THE NRN ROCKIES FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON WITH VALLEY RAIN/MOUNTAIN SNOW IMPACTING MAINLY THE CNTRL MOUNTAINS AND ERN HIGHLANDS. THE SECOND STORM WILL ARRIVE MONDAY WITH THE GFS INDICATING A FAIRLY SHALLOW WAVE BRUSHING THE DIVIDE REGION WHEREAS THE ECMWF IS ADVERTISING A MUCH DEEPER WAVE DIGGING THROUGH SRN IDAHO WITH A VIGOROUS SHOT OF PRECIPITATION FOR SE IDAHO. HAVE MAINTAINED THE GOING GRIDS WHICH ESSENTIALLY FOLLOWED THE GFS TIMING AND STRENGTH. WILL CONTINUE TO WATCH THE GFS TO SEE IF IT MAKES A MOVE TOWARD THE STRONGER ECMWF FOR MONDAY. TEMPS GENERALLY RUNNING WELL ABOVE NORMAL THROUGH THE PERIOD. HUSTON AVIATION...THE UPPER TROUGH AXIS WAS SHIFTING INTO THE WYOMING BORDER REGION EARLY THIS MORNING WHILE RADAR CONTINUED TO SHOW A BROAD AREA OF MODEST SNOWFALL ACROSS THE SE HIGHLANDS. MODELS SUGGEST THAT AS THE RIDGE BUILDS ALONG THE COAST THIS MORNING...THE FLOW WILL TURN MORE NORTHERLY ACROSS SE IDAHO RESULTING IN A LINE OF WIND CONVERGENCE WORKING DOWN THE VALLEY STARTING NEAR KRXE AT ABOUT 14Z AND ADVANCING THROUGH KIDA AND KPIH THROUGH 18Z WITH ACCOMPANYING MVFR CIGS AND REDUCED VIS IN SNOW SHOWERS. BEYOND 21Z...SUBSIDING NE WINDS WILL EFFECTIVELY CLEAR THE REGION OUT WITH VFR CONDITIONS PREVAILING OVERNIGHT. KSUN SHOULD REMAIN VFR THROUGHOUT THE ENTIRE FORECAST PERIOD. HUSTON && .PIH WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
620 AM CDT Tue Mar 11 2014 ...UPDATE TO AVIATION... .SYNOPSIS... ISSUED AT 343 AM CDT TUE MAR 11 2014 Water vapor loop as of 08Z showed an impressive shortwave trough continuing to dig southeastward into Utah. RAP analysis had a 400mb potential vorticity (PV) anomaly extending from the base of the trough near Great Salt Lake northeastward into eastern Washington...suggesting a little more digging before the wave translates eastward. Warmest temperatures in the lower troposphere (850mb) were found across the High Plains of western Kansas into West Texas (+17C at both North Platte and Dodge City; +20C at Amarillo). The 08Z surface analysis showed a deepening surface low centered near the western Nebraska-Kansas state border. Surface winds continued to respond with overnight winds in the 10 to 13 knot range, helping keep temperatures from dropping much. It was still in the lower to mid 40s across much of the southwest and west central Kansas region. Surface cold frontogenesis was noted across northeastern Wyoming into the northern Nebraska Panhandle. && .SHORT TERM...(Today and tonight) ISSUED AT 343 AM CDT TUE MAR 11 2014 Moderate to high impact wind event this afternoon/evening is the main forecast challenge and how to handle this event with headlines (advisory vs. warning). Now that the forecast wind event is within higher resolution short-term models (RAP13, for instance) temporal range, we are gaining a bit higher confidence in the wind forecast. As the surface low moves southeast into central Kansas, it will continue to deepen down to about 995mb while surface anticyclogenesis will ramp up across the northern Rockies and adjacent High Plains. This will induce a very tight pressure gradient across western Kansas by midday...and especially this afternoon. The combined effect of the pressure gradient and the isallobaric wind due to pressure change, will likely lead to sustained winds around 40 mph for areas along and west of Highway 283 corridor...especially in the 22-01Z time frame. Forecast soundings off the NAM12 and RAP13 both show around 35 knots just off the surface around 900mb at Dodge City at 21Z with mixing up to 800-825mb. The winds around 800-850mb will pick up quite a bit as the north wind low level jet strengthens west of the low at this level. For Dodge City, the 00Z forecast soundings support a high wind event (40mph sustained and/or 58mph gusts) with 50 knots shown by both the NAM12 and RAP13 at the top of the mixed layer (which by that point will be due to vigorous cold advection). Based on this information, we will upgrade to a High Wind Warning for US283 corridor (Ness City down to Englewood) west to the Colorado border. Per collaboration with surrounding offices, we will also include areas of blowing dust where the High Wind Warning will be in effect and hit it pretty hard in the NPW product. As far as precipitation goes, the only area expected to see any measurable precipitation will be the I-70 corridor, and will carry around 50 POPs up there. A few tenths of an inch of wet snow may accumulate during the 23-02Z time frame in particular. .LONG TERM...(Wednesday through Monday) ISSUED AT 300 AM CDT TUE MAR 11 2014 Medium range models indicate an upper level shortwave breaking away from a larger scale trough Wednesday as it digs southeast across the Rockies, and developing into a closed off upper level low across the Intermountain West. Meanwhile, a general westerly flow aloft will prevail across the Western High Plains through the end of the week. This will result in dry conditions persisting across western Kansas through Thursday night with insufficient low/mid level moisture present. The closed off upper level low in the Desert Southwest is then expected to open up and push eastward into the South Plains early Friday bringing marginal precip chances to the Texas and Oklahoma panhandles based on the projected track of the shortwave. Cannot rule out a slight chance for light rain across extreme southern portions of southwest and south central Kansas Friday as the upper level system skirts across our southern fringe. Much cooler temperatures are likely Wednesday as arctic air spills southward into western Kansas in wake of a departing cold front. The NAM/GFS/ECMWF show H85 temperatures dropping well below 0C across central and western Kansas initially Tuesday night. A slight rebound to around 0C across central Kansas to near 5C along the Colorado border is expected Wednesday afternoon due to some northwesterly downsloping developing. Expect highs up into the upper 40s(F) to possibly the lower to mid 50s(F) under decreasing cloud cover. A quick bounce back to warmer temperatures will occur Thursday as the arctic high dips further south across Texas while lee side troughing redevelops across eastern Colorado. This will quickly return a southwesterly downslope flow to western Kansas pushing H85 temperatures up into the lower to mid Teens(C) across central and western Kansas. Highs will easily reach the 60s(F) Thursday afternoon with near 70F not out of the question in some locations. Another cold front is projected to push through western Kansas early Friday once again dropping temperatures across the area. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) ISSUED AT 620 AM CDT TUE MAR 11 2014 VFR conditions will prevail at all TAF sites through early this afternoon. Low level stratus is expected to develop behind a cold front as it pushes across western Kansas this afternoon. MVFR cigs will be possible late this afternoon into this evening at all TAF sites as a result. Strong northerly winds will develop behind the cold front this afternoon with sustained winds of 35 to 45kt and gusts up to 50kt. This may result in periods of blowing dust reducing visibilities to MVFR in the vicinity of KGCK and KDDC. Brief IFR vsbys cannot be ruled out. Light snow will be possible in the vicinity of KHYS this evening which may result in IFR vsbys in blowing snow. The winds will become more northwesterly tonight while subsiding somewhat. && .PRELIMINARY POINT TEMPS/POPS... DDC 59 27 51 26 / 20 20 0 0 GCK 56 25 50 24 / 20 20 0 0 EHA 63 27 48 28 / 10 10 0 0 LBL 64 26 50 25 / 10 10 0 0 HYS 55 27 50 24 / 40 50 0 0 P28 62 30 52 28 / 10 10 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING from 1 PM CDT /Noon MDT/ this afternoon to 11 PM CDT /10 PM MDT/ this evening FOR KSZ043>045-061>064-074>078- 084>088. WIND ADVISORY from 1 PM this afternoon to 11 PM CDT this evening FOR KSZ030-031-046-065-066-079>081-089-090. && $$ SYNOPSIS...Umscheid SHORT TERM...Umscheid LONG TERM...JJohnson AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1033 AM EDT TUE MAR 11 2014 .SYNOPSIS... HIGH PRESSURE WILL PERSIST OVER THE SOUTHEASTERN STATES TODAY AS LOW PRESSURE MOVES EAST ACROSS QUEBEC. STRONG LOW PRESSURE AND ITS ASSOCIATED COLD FRONT WILL PASS THROUGH LATER WEDNESDAY INTO WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD OVERHEAD THURSDAY BEFORE MOVING OFF THE COAST FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... MRNG SFC ANALYSIS SHOWS HIPRES SITUATED EAST OF THE FL COAST WHILE UPSTREAM LOPRES IS LOCATED OVER KANSAS. A DIFFUSE FRONTAL BOUNDARY HAS BEEN STATIONARY FROM THE NRN MID-ATLANTIC STATES AND EXTENDS WESTWARD BACK TOWARD THE CENTRAL PLAINS LOW. SWLY FLOW AHEAD OF THE LOW AND ON THE BACKSIDE OF THE HIGH WILL DRAW WARMER AIR INTO THE MID-ATLANTIC STATES THRU TNGT. FOR THE SECOND CONSECUTIVE DAY...OROGRAPHIC MID AND HI CLOUDS DEVELOPED TO THE LEE OF THE ALLEGHENY FRONT OVNGT AND CONTINUED INTO THE MRNG. THE BIG QUESTION REMAINS HOW QUICKLY THESE CLOUDS WILL DISSIPATE. LATEST RAP SHOWS MOISTURE AND WEAK ISENTROPIC LIFT IN THE 700-400 MB LAYER PERSISTING THRU AT LEAST MID AFTN...THOUGH DRIER AIR MAY ERODE CLOUDS IN CENTRAL VA AND SRN MD DURING THIS TIME. FCST WAS UPDATED TO HOLD ON TO THESE MT WAVE CLOUDS LONGER INTO THE AFTN...PARTICULARLY ACROSS THE NRN HALF OF THE CWA. WHILE CLOUDS WILL LIMIT HEATING...DID NOT WANT TO LOWER MAX TEMP FCST TOO MUCH WITH THE ALREADY WARM START TO THE DAY AND GIVEN THAT EVEN A COUPLE OF HRS OF SUNSHINE LATER IN THE DAY WILL MIX OUT THE SHALLOW NOCTURNAL BOUNDARY LAYER EVIDENT ON THE 12Z IAD RAOB...RESULTING IN A QUICK JUMP IN TEMPS. SFC BOUNDARY IS FCST TO STALL CLOSE TO THE POTOMAC RIVER TNGT. LGT SELY FLOW SOUTH OF THE BOUNDARY WILL BE ACCOMPANIED BY MILDER OVNGT TEMPS WHILE ELY ALONG AND COOLER CONDITIONS RESIDE ALONG AND NORTH OF THE BOUNDARY. PRE-FRONTAL PRECIP IS EXPTECTED TO STAY WEST OF THE AREA BEFORE SUNRISE WED. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... MIDWEEK SYSTEM FOR CWFA LOOKING INCRSGLY WARM AND CNVCTV...AS MDL CONSENSUS TAKES TRACK OF SFC LOW N OF CWFA. /NAM STILL APPEARS TO BE AN OUTLIER AND WAS NOT USED./ THEREFORE...AREA WL BE W/IN WM SECTOR OF SYSTEM WED AS CDFNT ENTERS DURING PK HTG...WITH ALL THAT ENTAILS. SFC LOW WL HV STRONG ASSOCD DYNAMICS...IN TERMS OF S/WV ENERGY...A VIGOROUS WIND FIELD...AND BAROCLINICITY. SFC SYSTEM WL HV LIFT FM RRQ NRN STREAM AND LFQ SRN STREAM UPR JETS. PLUS...A RAPID DROP IN H5 HGTS WL ADD TO THE POTENCY OF THE ENVIRONMENT. THESE FACTORS WL SUPPORT A STRENGTHENING LOW...WHICH WL BE NEAREST PTMC HIGHLANDS NEAR 18Z. AM THINKING THAT THERE WL BE AMPLE CLDCVR DURING THE MRNG...BUT ANY BREAKS CUD LEAD TO INSTBY DUE TO AFTN DEWPTS INTO THE LWR 50S. GFS PROGS A FEW HND JOULES OF CAPE BY THIS TIME...AS CDFNT/HGT FALLS ENTER THE SCENE. THINK THAT THERE WL BE ENUF GOING FOR UPDRAFTS TO DVLP...AND CANNOT PRECLUDE A MORE CONCENTRATED LINE OF SHRA/TSRA /INSTEAD OF A MORE WIDESPREAD OCNL SHRA SITUATION/. WNDS BY THIS PT ON THE ORDER OF 40-50 KT...WHICH CUD BE TRANSPORTED TO THE SFC IN ANY SHRA/STORM. THEREFORE FEEL THAT THERES A RISK OF DMGG WND GUSTS. ALREADY HV CHC TSRA IN GRIDS AND SVR RISK IN HWO. RAISED MAXT CLSR TO 70F DC SWD IN RESPONSE TO WAA AHD OF FNT. A RAPID DROP IN TEMPS IS STILL XPCTD WED NGT IN THE WAKE OF THE FROPA. LTST INDICATIONS ARE THAT PCPN WL DEPART FIRST ACRS MUCH OF THE AREA. THE STORY WL BE DIFF FOR THE WRN SLOPES OF THE APLCNS. HV KEPT CAT POPS FOR OCNL SHSN. DONT BELIEVE SNW WL BE A BIG IMPACT EVEN THERE. THE BIGGER STORY WED NGT INTO THU MRNG WL BE THE WND FIELD AND TEMPS...AS STRONG CAA WL SUPPORT MIXING OF 45 KT W/IN BNDRY LYR. HV ONCE AGN BOOSTED WNDS IN THE GRIDS. SUSPECT A WND ADVY WL BE NCSRY AT SOME PT...ALTHO PERHAPS NOT FOR THE ENTIRE CWFA. MOS CONSISTENT W/ MIN-T THU MRNG IN THE TEENS AND 20S...MEANING ACTUAL TEMP DROPS OF 40-50F-- AND THATS NOT FACTORING IN WND CHILL. ON TOP OF THE SNW FOR THE MTNS...WND CHILL VALUES APPROACHING ADVY LVLS AS WELL. IMPACT OF CAA IN FULL EFFECT THU. MAXT BEEN FAIRLY CONSISTENT FOR A CPL CYCLES...SUGGESTING IT/LL BE A STRUGGLE TO RISE ABV FRZG ACRS NRN MD AND W OF THE SHEN VLY. DO THINK THAT THE DOWNSLOPING FLOW WL RIP APART ANY CLD DECK...SO WL HV AMPLE BUT INEFFECTUAL SUNSHN. ON THE WRN SLOPES...SAME BASIC THEME AS HIPRES BLDS...BUT THE CLRG WL BE A LTL DELAYED. STILL HV PTSUN AND A CHC SHSN FOR THE MRNG. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... SUNNY SKIES WILL ALLOW TEMPERATURES TO REBOUND NICELY FRIDAY FROM LOWS IN THE LOWER TO MID 20S IN THE MORNING TO HIGHS IN THE 50S DURING THE DAYTIME AS HIGH PRESSURE OVER THE SOUTHEASTERN US STRETCHES UP INTO OUR AREA. SOUTHWEST FLOW WILL FILL IN AS THE HIGH MOVES OFF THE CAROLINA COAST FRIDAY EVENING. LOWS SATURDAY MORNING WILL BE IN THE 30S AND HIGH TEMPS ON SATURDAY AFTERNOON SHOULD REACH INTO THE UPPER 50S TO LOWER 60S. LOW PRESSURE LOCATED NORTH OF THE GREAT LAKES WILL CAUSE A WEAK COLD FRONT TO SWING THROUGH THE MID ATLANTIC SATURDAY NIGHT. ASIDE FROM SOME LIGHT PRECIP WEST OF THE BLUE RIDGE...LOCAL IMPACTS SHOULD BE LIMITED TO INCREASED CLOUD COVER SATURDAY AFTERNOON AND A HIGH TEMPERATURE ON SUNDAY IN THE LOWER 50S...5 TO 10 DEGREES COOLER THAN THE HIGH ON SATURDAY. AN UPPER LEVEL DISTURBANCE WILL APPROACH THE AREA OVERNIGHT SUNDAY...BRINGING OUR BEST CHANCES OF PRECIP IN THE PERIOD. STILL PLENTY OF UNCERTAINTY IN THE FORECAST...BUT A WINTRY MIX IS POSSIBLE FOR SOME LOCATIONS IN THE EARLY MORNING HOURS ON MONDAY BEFORE PTYPE SHOULD SWITCH OVER TO LIGHT RAIN FOR THE REST OF THE MORNING. COOL AIR WILL FILL IN ONCE AGAIN BEHIND THIS FRONT AND HIGH TEMPERATURES ON MONDAY WILL ONLY GET INTO THE 40S. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS TDA AND TNGT. LGT SWLY WINDS TDA WILL BECOME E/SE TNGT. FLGT RESTRICTIONS /MVFR-IFR/ LKLY WED...MAINLY AFTN-EVE...IN RESPONSE TO LOPRES TRACKING N OF TERMINALS DRAGGING A CDFNT THRU. A PROLONGED PD OF RESTRICTIONS LOOKING LESS LKLY THO...AS PCPN WL BE SHOWERY IN NATURE. LWS ALSO LKLY BOTH AHD OF AND BHD FNT...AS 40-50 KT OF WND WL BE PRESENT 2000-3000 FT OFF THE GRND. WINDY CONDS /NW 20G35-40KT/ WL CONT INTO THU...BUT WL GRDLY SUBSIDE THRU THE AFTN. OTRW...VFR SHUD PREVAIL INTO THE WKND. && .MARINE... LGT WINDS TDA. WINDS BECOME SELY LATE TONIGHT. WIND GUSTS APPROACH SCA CRITERIA CLOSE TO 12Z OVER THE MID CHSPK BAY BUT HAVE CAPPED IT AT 15 KT AT THIS TIME WITH SUCH A MARGINAL SETUP. SLY FLOW WL INCR WED AHD OF CDFNT. HV RAISED SCA FOR THE TIME BEING DURING THE AFTN FOR ALL WATERS. HWVR...BEST RISK OF WNDS MIXING TO SFC WL BE IN ASSOCIATION W/ CNVCTN...WHICH MAY REQUUIRE SMW/S INSTEAD. ONCE THE CDFNT CROSSES THE MARINE AREA WED NGT...WNDS WL VEER NWLY AND PICK UP SGFNTLY. GDNC STILL SUGGESTING THAT GLW LKLY WED NGT... LASTING INTO THU. BYD THAT...RAMP DOWN SCA CONDS XPCTD INTO FRI AS HIPRES BLDS. && .TIDES/COASTAL FLOODING... TIDAL DEPARTURES ALREADY UP TO A FT ABV NORMAL. ELEVATED WATER LVLS SHUD CONT THRU THE DAY TODAY...BUT SEE NO REASON WHY INCREASES SHUD WIDEN. MDL GDNC CONCURS. THE BEST PUSH OF SLY FLOW COMES WED...ESPECIALLY DURING THE MIDDAY AND AFTN AHD OF A STRONG CDFNT. WHILE THE HIGHER OF THE TWO TIDE CYCLES COMES AT NIGHT...THE DIFFERENCE IS ONLY A MATTER OF INCHES. WOULD THINK THAT THE PM CYCLE WOULD STILL HAVE A HIGHER RISK...DUE TO WHEN THE PUSH OF SLY FLOW ARRIVES. BEST ESTIMATE IS THAT MINOR INUNDATION MAY RESULT. EXPECT A BLOW OUT TO OCCUR WED NGT...BUT AM UNSURE HOW IT WL INTERACT/BE TIMED COMPARED TO THE INCOMING TIDE CYCLE. REGARDLESS... ONCE THE WED NGT TIDE PULLS OUT...WATER SHUD BE DRIVEN OUT...AND WL BE TALKING ABOUT NEGATIVE WATER LVL DEPARTURES BY THU. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON TO 6 PM EDT WEDNESDAY FOR ANZ530>543. && $$ SYNOPSIS...HTS NEAR TERM...JRK SHORT TERM...HTS LONG TERM...CEB AVIATION...JRK/HTS MARINE...JRK/HTS TIDES/COASTAL FLOODING...HTS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
740 AM EDT TUE MAR 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 509 AM EDT TUE MAR 11 2014 WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL FLOW FROM THE NRN PLAINS THROUGH THE NE CONUS. A SHORTWAVE TROUGH OVER NRN MANITOBA ON THE LEADING EDGE OF VERY COLD ARCTIC AIR IS EXPECTED TO SLIDE TO THE SE AS A RIDGE BUILDS INTO WRN CANADA. ANOTHER SHRTWV OVER SASK IS ALSO EXPECTED TO DIVE TOWARD THE UPPER MS VALLEY AS THE PATTERN AMPLIFIES. AT THE SFC...A COLD FRONT TRAILING LOW PRES OVER QUEBEC EXTENDED THROUGH NRN ONTARIO INTO SRN MANITOBA. TO THE SOUTH...MILD CONDITIONS PREVAILED WITH READINGS REMAINING IN THE UPPER 30S TO AROUND 40 FROM NRN MN AND NRN WI THROUGH UPPER MI. EXTENSIVE MID/HIGH CLOUDS HAVE ALSO LIMITED RADIATIONAL COOLING. TODAY...THE COLD FRONT IS EXPECTED TO MOVE THROUGH LAKE SUPERIOR AND UPPER MICHIGAN THIS MORNING BRINGING AN INITIAL INFLUX OF COLDER AIR. SO...MAX DAYTIME READINGS ARE EXPECTED EARLY WITH TEMPS STEADY OR SLOWLY FALLING DURING THE AFTERNOON. AS LOW LEVEL MOISTURE NORTH OF LAKE SUPERIOR MOVES IN AND 850 MB TEMPS FALL TO AROUND -13C BY 00Z/WED...SOME LIGHT SNOW SHOWERS OR FLURRIES MAY BE POSSIBLE LATE OVER THE NORTH AND WEST PORTIONS OF THE CWA. TONIGHT...AS THE SASK SHRTWV MOVES TOWARD THE AREA MUCH COLDER ARCTIC AIR WILL PUSH INTO THE REGION WITH 925 MB TEMPS DROPPING TO AROUND -21C AND INCREASING WINDS VEERING FROM THE FROM THE NNW TO NE. A PERIOD OF DEEPER MOISTURE ALONG WITH THE LOW LEVEL INSTABILITY WILL FAVOR SOME LES FOR LOCATIONS DOWNWIND OF LAKE SUPERIOR...ESPECIALLY WHERE UPSLOPE FLOW IS MAXIMIZED. THE POSITION OF THE DGZ WILL ALSO BE MOST FAVORABLE FROM 06Z-12Z/WED. SATELLITE IMAGERY FROM MON SHOWED ENOUGH BREAKS IN THE ICE COVER FOR AT LEAST SOME HEAT/MOISTURE FLUX FROM THE LAKE TO SUPPORT LES. SINCE THE ICE WILL STILL SIGNIFICANTLY REDUCE THE LES POTENTIAL...EXPECT SNOWFALL AMOUNTS ONLY IN THE 1 TO 2 INCH RANGE...GREATEST OVER THE HIGHER TERRAIN OF N CNTRL UPPER MI. THE NE WINDS WILL BE LESS FAVORABLE FOR SNOW AT IWD...WITH THE HIGHER CHANCES/AMOUNTS FARTHER TO THE WEST...OR FOR THE KEWEENAW WHERE LOW LEVEL CONV WILL BE MINIMAL. OTHERWISE...THE MUCH COLDER AIR WITH LOWS NEAR ZERO AND WINDS OF 10 TO 20 MPH WILL PRODUCE WIND CHILLS FROM -10 TO -20 LATE TONIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 343 AM EDT TUE MAR 11 2014 HIGH PRESSURE OVER NORTHWEST ONTARIO WILL LEAD TO NORTHEAST LOW LEVEL FLOW OVER THE UPPER GREAT LAKES REGION TO START THE LONG TERM PERIOD. THIS NORTHEAST FLOW WILL BE PRODUCING UPSLOPE SNOW SHOWERS ESPECIALLY IN NORTH CENTRAL UPPER MICHIGAN TONIGHT AND EXPECT THOSE TO CONTINUE INTO WEDNESDAY. ALTHOUGH WINDS HAVE CREATED SOME GAPS IN THE ICE NEAR THE SOUTHERN SHORELINE OF CENTRAL/EASTERN LAKE SUPERIOR...NOT THINKING THAT THERE WILL BE TOO MUCH ASSISTANCE TO THE UPSLOPE SNOW SHOWERS EVEN THOUGH 900MB TEMPS WILL BE AROUND -22C. WITH INVERSION HEIGHTS ONLY AROUND 3-4KFT...WOULDN/T EXPECT THE SNOW SHOWERS TO BE TOO STRONG AND ANY ADDITIONAL ACCUMULATIONS SHOULD BE LIGHT WITH THE CLOUD BEING ABOVE THE DGZ. DID SLOWLY DIMINISH THE SNOW SHOWER CHANCES THROUGH THE DAY AS THE MOISTURE DEPTH BECOMES SHALLOW AND WINDS BACK TO THE NORTH-NORTHWEST. WITH THE MODELS SHOWING THE MOISTURE REMAINING BELOW THE STRENGTHENING INVERSION FROM THE HIGH MOVING OVER THE UPPER GREAT LAKES...WONDERING IF CLOUDS WILL HOLD OVER THE AREA INTO THE AFTERNOON (ESPECIALLY OVER THE NORTH CENTRAL). THE NORTHERLY WINDS AND CLOUDS WILL LEAD TO A VERY COLD DAY ACROSS UPPER MICHIGAN...WITH HIGHS IN THE UPPER SINGLE DIGITS TO MID TEENS. STILL LOOKS TO BE A VERY COLD NIGHT ON WEDNESDAY NIGHT AS THE HIGH SHIFTS SOUTHEAST ACROSS THE CWA. WILL CONTINUE TO SHOW THE COLDEST VALUES OF -10F TO -18F OVER THE EAST HALF OF THE CWA AND THE SINGLE DIGITS BELOW ZERO OVER THE WEST HALF. WOULD EXPECT THE TEMPERATURES TO WARM OVER THE WEST TOWARDS MORNING AS RETURN FLOW DEVELOPS AND MID CLOUDS BEGINNING TO MOVE IN UNDER WAA AHEAD OF THE NEXT CLIPPER SYSTEM. GEM/ECMWF/NAM CONSISTENT ON SOME LIGHT PRECIPITATION MOVING INTO THE WESTERN U.P. WITH THIS WAA ON THURSDAY MORNING. SINCE THERE HAVE BEEN INDICATIONS OF THIS OVER THE LAST COUPLE OF DAYS...WILL TREND VALUES UP TO CHANCES AND THEN DIMINISH THEM AS THEY HEAD EAST OVER THE REST OF THE CWA DURING THE AFTERNOON. WHILE EARLIER RUNS WERE INDICATING A LACK OF ICE CRYSTALS FOR THIS PRECIPITATION...IT NOW APPEARS THAT THERE WILL BE ENOUGH MOISTURE IN THE ICE CRYSTAL AREA TO SUPPORT ALL SNOW. AT THIS POINT...MIGHT SEE UP TO A HALF INCH TOWARDS IRONWOOD AND THEN DIMINISHING AMOUNTS HEADING EAST. BEHIND THIS PRECIPITATION...FOCUS TURNS TO THE LOW CENTERED NEAR LAKE WINNIPEG AT 18Z THURSDAY. THIS LOW WILL TRACK SOUTHEAST THROUGH THE UPPER GREAT LAKES REGION LATE THURSDAY NIGHT INTO FRIDAY. MODELS STILL DIFFERING ON THE SHORTWAVE...WHICH IS NOW WELL OVER THE PACIFIC...WHICH IN-TURN CONTROLS THE TRACK OF THE LOW. GFS HAS CONSISTENTLY BEEN THE FARTHEST NORTH (ALONG WITH RECENT RUNS OF THE UKMET) AND RUNNING THE LOW ALONG THE NORTH SHORE OF LAKE SUPERIOR...WHILE THE ECMWF TRACKS THE LOW ALONG THE SOUTH SHORE. THE GEM HAS BEEN BOUNCING BETWEEN THE TWO OVER THE LAST COUPLE DAYS. ALL IN ALL...THESE DIFFERENCES WON/T HAVE TOO MUCH OF AN AFFECT ON THE LAND CWA PRECIPITATION...SINCE THE WAA PRECIP WILL BE OVER NORTHEAST LAKE SUPERIOR AND ONTARIO THURSDAY NIGHT. UNFORTUNATELY FOR THOSE LOOKING FOR ANOTHER REALLY WARM DAY...IT APPEARS THAT THE WARM AIR ALOFT WILL MOVE THROUGH ON THURSDAY NIGHT AND THEN AREA WILL SEE COLDER AIR MOVING IN THROUGH THE DAY. THUS...EXPECT THE WARMEST TEMPS ON FRIDAY TO BE NEAR LAKE MICHIGAN AND IN THE UPPER 30S TO AROUND 40. WITH THE DIFFERENCES IN THE TRACK OF THE LOW...THERE ARE ALSO DIFFERENCES IN THE ARRIVAL OF THE SECONDARY COLD FRONT AND NORTHERLY WINDS. COULD BE A LITTLE BREEZY OUT OF THE WEST ON FRIDAY BEFORE THIS ARRIVES...WITH WINDS TURNING TO THE NORTHWEST AND EVENTUALLY NORTHERLY ON FRIDAY NIGHT. EXPECT SOME PRECIPITATION ASSOCIATED WITH THIS COLD SURGE AND WITH SOME GAPS STARTING TO SHOW IN THE ICE NEAR THE APOSTLE ISLANDS...THERE COULD EVEN BE SOME LAKE ENHANCED/EFFECT SNOW FRIDAY NIGHT INTO SATURDAY. DIFFICULT TO GO WITH MUCH MORE THAN SLIGHT/CHANCE POPS WITH THE AMOUNT OF ICE COVER AND POTENTIAL CHANGES OVER THE NEXT SEVERAL DAYS...SO WILL FOLLOW A SIMILAR IDEA AS THE PREVIOUS SHIFT. THAT PUTS CHANCES OVER THE FAVORED NORTHWEST AREAS IN THE WEST ON FRIDAY NIGHT AND THEN TRANSITION TO TRADITIONAL NORTHWEST-NORTHERLY WIND AREAS FOR SATURDAY. WITH A HIGH PRESSURE RIDGE NOSING SOUTH FROM ONTARIO ON SATURDAY NIGHT AND SUNDAY...EXPECT DRIER AIR TO MOVE IN AND HAVE DIMINISHED POPS HEADING INTO SUNDAY (EVENTHOUGH 850MB TEMPS REMAIN AROUND -17C). WITH THE COLD TEMPS ALOFT...SHOULD BE 10-20 DEGREES BELOW NORMAL FOR HIGHS THIS WEEKEND. DEPENDING ON HOW QUICKLY SKIES CLEAR OUT ON SATURDAY NIGHT...THERE IS THE POTENTIAL FOR SUB ZERO LOWS OVER MUCH OF THE AREA AND HAVE TRENDED VALUES DOWN A COUPLE DEGREES. THE COLDEST NIGHT WILL BE SUNDAY NIGHT AS THE AREA OF HIGH PRESSURE MOVES OVER THE CWA. SINGLE DIGITS BELOW ZERO SEEMS LIKE A GOOD START AT THIS POINT...BUT WOULDN/T BE SURPRISED TO SEE SOME COLD SPOTS IN THE TEENS BELOW ZERO. THE HIGH IS EXPECTED TO SHIFT EAST ON MONDAY...BUT IT/S INFLUENCE WILL REMAIN AND KEEP THE AREA DRY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 739 AM EDT TUE MAR 11 2014 A COLD FRONT WILL PASS THROUGH UPPER MI THIS MORNING. THE RETURN OF COLDER AND MOISTER LOW LEVEL AIR AIDED BY SOME DAYTIME HEATING/DESTABILIZATION SHOULD RESULT IN AN MVFR SC DECK AT ALL 3 LOCATIONS BY THIS AFTERNOON. THE APPROACH OF A DISTURBANCE EMBEDDED IN THE NW FLOW ALOFT THIS EVNG MAY BRING SOME SHSN TO THE AREA... ESPECIALLY AT IWD WHICH WL BE CLOSER TO THE TRACK OF THIS SYSTEM. THE COMBINATION OF VERY COLD AIR OVER EVEN LIMITED GAPS IN THE LAKE SUPERIOR ICE COVER AND UPSLOPE INTO SAW SHOULD PRODUCE SOME -SHSN. HOWEVER...NOT CONFIDENT THAT CONDITIONS WILL DROP ANY LOWER THAN MVFR. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 509 AM EDT TUE MAR 11 2014 A COLD FRONT WILL MOVE THROUGH THE AREA TODAY WITH NW TO N WINDS INCREASING TO 20 TO 30 KNOTS OVER ERN LAKE SUPERIOR THIS AFTERNOON INTO TONIGHT. WINDS WILL DIMINISH WED INTO WED NIGHT AS HIGH PRES BUILDS OVER THE NRN LAKES. WINDS WILL REMAIN AT OR BELOW 20 KNOTS UNTIL FRIDAY WHEN ANOTHER LOW PRES SYSTEM JUST TO THE NORTH OF LAKE SUPERIOR BRINGS WEST AND NORTHWEST WINDS OF 20 TO 30 KNOTS AS IT MOVES THROUGH THE REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
704 AM CDT TUE MAR 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CDT TUE MAR 11 2014 MOST SIGNIFICANT PRECIPITATION OVER THE NEXT 7 DAYS WILL FALL WITHIN THE NEXT 12 HRS OF THIS DISCUSSION AS AN IMPRESSIVE FRONTGENETICALLY DRIVEN BAND OF PRECIP BLOSSOMS ACROSS THE SOUTHERN HALF OF THE CWA THIS MORNING. HIRES MODELS CONTINUE TO BE TOO COOL WITH THE LOW LEVEL THERMAL FIELDS...AND THUS THEIR PTYPE ALGORITHMS ARE LIKELY OVERDOING THE SNOWFALL ACROSS THE REGION DURING THE INITIAL DEVELOPMENT EARLY THIS MORNING. HOWEVER...BUFR FORECAST SOUNDINGS SHOW TREMENDOUS LIFT ALONG THE LOW/MID LEVEL FRONT AS INFERRED FROM THE SHARP WIND SHIFT WITHIN THE H850-700 LAYER. ASIDE FROM THE LOWEST FEW HUNDRED METERS THE ENTIRE SOUNDING IS BELOW FREEZING...SO ANTICIPATING THAT THE RAIN WILL CHANGE OVER TO A RAIN SNOW MIX AROUND 6-7AM...AND THEN QUICKLY OVER TO HEAVY WET SNOW AROUND MID MORNING ACROSS SOUTHERN MN. SNOW RATIOS WILL BE IN THE MID-SINGLE DIGITS...BUT QPF SHOULD EASILY MANAGE AROUND 0.20 TO 0.30 YIELDING SNOWFALL TOTALS OF 1-2 INCHES UNDER THE HEAVIEST BAND OF SNOW. AT THIS POINT THE RAP 11.07 PLACES THIS HEAVY BAND FROM CANBY MN EASTWARD THROUGH THE SOUTHERN METRO...AND THEREFORE ALL THE HIRES MODELS THAT USE THE RAP FOR THEIR INITIAL BOUNDARY CONDITIONS ARE SUBCONSCIOUSLY DRAWN TO THIS CONCLUSION. HOWEVER...THE H850-700MB FGEN...WHICH AS OF EARLY THIS MORNING MATCHES UP NICELY WITH THE ONGOING PRECIP...SHIFTS SOUTHEAST FROM CANBY TO MANKATO AND OWATONNA. BASED ON THAT DIAGNOSTIC TOOL...EXPECT THE PRECIP TO FALL TOWARD THE SOUTHERN SIDE OF THE CURRENT MODEL GENERATED QPF FIELD. AT THIS POINT NOT ANTICIPATING ANY ADVISORY CRITERIA SNOWFALL AMOUNTS...BUT EXPECT HEAVY WET SNOW WITH 1/2 TO 1/4 MI VISIBILITY POSSIBLE AT TIMES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 345 AM CDT TUE MAR 11 2014 LOOKING AHEAD...COLD AIR WILL SURGE SOUTHWARD BEHIND THIS SYSTEM AS IT STRENGTHENS INTO A MAJOR STORM OVER NEW ENGLAND. CLOSER TO HOME TEMPERATURES WILL FALL BELOW FREEZING TONIGHT AND REMAIN THERE UNTIL THURSDAY WHEN THE NEXT SHOT OF LEE-SIDE WARM AIR SPREADS ACROSS THE REGION. THIS WILL BRING TEMPERATURES INTO THE 40S ONCE AGAIN...WITH 50S IN WESTERN MN. THERE IS A CHANCE FOR SOME LIGHT PRECIP AHEAD OF THIS WARM AIR ADVECTION...MAINLY ALONG THE ST CROIX RIVER VALLEY. THIS WARMUP WILL BE SHORT LIVED AS COLD AIR SPREADS SOUTHWARD AND LASTS INTO NEXT WEEK. NO SIGNIFICANT PRECIPITATION IS EXPECTED UNTIL THE NEXT STORM SYSTEM ARRIVES ON TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 626 AM CDT TUE MAR 11 2014 BESIDES KRWF...THE SNOW SHOULD LARGELY MISS THE TAF SITES. IT`S EVEN UNCLEAR HOW MUCH SNOW WILL MIX WITH THE RAIN AT KRWF. MVFR CEILINGS ARE STILL LIKELY ACROSS SOUTHERN MN AND WEST CENTRAL WI TODAY WITH THE LIGHT RAIN...ESPECIALLY THIS MORNING AND EARLY AFTERNOON. AIRPORTS SHOULD RETURN TO VFR LATE THIS AFTERNOON AFTER THE PRECIP CLEARS THE AREA...WITH A POSSIBLE RETURN OF MVFR CEILINGS. OVERALL...WEATHER IMPACTS WILL NOT BE GREAT TODAY EVEN WITH THE PRECIP MOVING THROUGH. KMSP... WITH THE HEAVIER PRECIP GOING SOUTH OF THE AIRPORT AND THE TEMPERATURE HOLDING STEADY IN THE MID TO UPPER 30S...WE THINK SNOW IS LOOKING LESS LIKELY TODAY - PERHAPS JUST ONE HOUR OF A RAIN/SNOW MIX LATE THIS MORNING. THE SNOW SHOULDN`T BE HEAVY ENOUGH TO ACCUMULATE AND IT MAY NOT OCCUR AT ALL. MVFR CEILINGS ARE JUST TO THE WEST OF THE AIRPORT...BUT BASES SHOULD REMAIN ABOVE 2000 FT. /OUTLOOK FOR KMSP/ WED...VFR. N WIND 8 KTS BCMG W. THU...VFR. SW WIND 5-10 KTS. FRI...VFR. W 10-15 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JRB LONG TERM...JRB AVIATION...CLF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
623 AM CDT TUE MAR 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 339 AM CDT TUE MAR 11 2014 THE MODEL CONSENSUS SHOWS A STRONG AREA OF 700-500MB FRONTOGENESIS DEVELOPING ACROSS NERN NEB AROUND 18Z TODAY. THIS FGEN IS EXPECTED TO PRODUCE A FAIRLY STRONG BAND OF WET SNOW WITH HOURLY LIQUID RATES OF UP TO 0.10 INCHES. THE NAM RADAR PRODUCT SHOWS THIS BAND SETTING UP FROM AROUND CHAMBERS TO BROKEN BOW AT 21Z WHICH MOVES QUICKLY EAST OF THE FCST AREA BY 00Z. THE NAM HAS BEEN WOBBLING SOMEWHAT BUT THE CONCEPT OF FOLDED THETA E AND DEEP LIFT IN THE DENDRITIC GROWTH ZONE CONTINUES. THE 05Z RAP MODEL SETS IT UP FROM ONEILL TO SUTHERLAND. THE 00Z ECM FOLLOWS THE NAM WHICH MATCHES THE MODEL CONSENSUS. IN GENERAL...THE MODELS ARE CLUSTERING AROUND 0.20 INCHES OF LIQUID FOR THIS EVENT ALONG HIGHWAY 83 BUT THEN SPREAD OUT TO THE EAST AS SOME SIGNAL A WETTER EVENT AND OTHERS DRIER. THE MEDIAN QPF IN CUSTER COUNTY LOOKS TO BE AROUND 0.30 INCHES. GIVEN THE STRONG LIFT DEVELOPING...IT IS EXPECTED THERE WILL BE A PERIOD OF MODERATE TO HEAVY SNOW DEVELOPING LASTING 1 OR 2 HOURS AT THE MOST. THIS IS ABOUT A 6 HOUR PCPN EVENT WHICH EXITS THE FCST AREA BY AROUND 00Z. THERE IS A SHORT PERIOD OF RAIN BEFORE CHANGE OVER TO SNOW IN THE GFS AND NAM MODELS. H700MB TEMPERATURES COOL VERY RAPIDLY BEHIND THE COLD FRONT MARKING THE ONSET OF PCPN AND DEEP LIFT WILL AID THE DYNAMIC COOLING PROCESS. AN 8 TO 1 SNOW WATER RATIO WAS USED UP NORTH DURING THE MORNING HOURS WHICH WAS REDUCED TO 5 TO 1 DURING THE AFTERNOON. TEMPERATURES FALL TO THE LOW TO MID 30S DURING THE HEAVIEST SNOW AND THEN WARM UP ONCE THE SNOW LETS UP OR ENDS. THIS PRODUCED 1 TO 2 INCHES OF WET SNOW. THERE IS NO REASON TO UNDER ESTIMATE A SPRING STORM DURING THE 2ND WEEK OF MARCH AND THE SYSTEM FORECAST TO DEVELOP TODAY IS EXPECTED TO PRODUCE STRONG NORTH WINDS AS THE SFC LOW DEEPENS ACROSS EAST CENTRAL KANSAS. ALL MODELS SHOW 500M AGL WINDS INCREASING TO OVER 30 KT WHICH TRANSLATES TO 30 MPH AT THE SFC. THE NAM...GFS GUIDANCE...HRRR AND RAP MODELS ALL SHOW GUSTS TO NEAR 50 MPH DEVELOPING ACROSS CNTL NEB NORTH OF THE SFC LOW LOCATED ACROSS KS BY NOON TODAY. H850 WINDS INCREASE TO 45 TO 55 KT. THE WIND FORECAST IS A CONSENSUS OF MODEL GUIDANCE OUTPUT AND DETERMINISTIC SOLNS WHICH FOLLOWS THE MIDDLE ROAD. THE GFS AND THE ECM SPREAD THESE STRONGER WINDS FURTHER NORTH AND WEST THAN THE OTHER MODELS. A WEAK DISTURBANCE IS SHOWN BY THE MODELS TO MOVE ACROSS THE FCST AREA TONIGHT. THIS COULD PRODUCE SNOW FLURRIES OR PERHAPS ISOLATED SNOW SHOWER ACTIVITY AS IT TRANSLATES EAST ACROSS THE FCST AREA. LAPSE RATES STEEPEN AND REMAIN MOIST SUPPORTING THIS FORECAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 339 AM CDT TUE MAR 11 2014 THE SYSTEM BRINGING THE SNOW AND WIND TO THE FORECAST AREA TODAY AND TONIGHT WILL MOVE EAST AND BE PAST THE LOCAL AREA BY 12Z WEDNESDAY. THIS WILL PUT NEBRASKA UNDER SUBSIDENT AIR WEDNESDAY AND WITH DRY AIR ADVECTING IN EXPECTING MOSTLY SUNNY SKIES. ALTHOUGH NOT EXPECTING ADVISORY LEVEL WINDS WEDNESDAY...SIGNALS ARE COMING TOGETHER FOR A BREEZY DAY. MODELS ARE SHOWING A SECONDARY PV MAX DROPPING SOUTH ACROSS CENTRAL NEBRASKA THROUGH THE DAY...TO HELP ENHANCE WINDS ALOFT AND WITH STEEP SURFACE TO 700MB LAPSE RATES CONFIDENCE INCREASES ON BREEZY CONDITIONS. SOUNDINGS SHOW THE MIXED LAYER BETWEEN 700MB AND 800MB AND LOOKING AT MAXIMUM WINDS IN THAT LAYER UP TO 35KTS SO DECIDED TO INCREASE WINDS DURING THE DAY. TEMPERATURES ALOFT DON/T CHANGE SIGNIFICANTLY ON WEDNESDAY SO LOOKING AT AN ADIABATIC PROFILE...HIGHS WOULD BE IN THE 40S FOR MOST LOCATIONS. HOWEVER...MODELS HAVE BEEN CONSISTENTLY A BIT COOL FOR TEMPERATURES AND WITH SUNNY SKIES THINK MOST AREAS WILL WARM A BIT MORE THAN THE DETERMINISTIC MODELS ARE INDICATING. DRY WEATHER IS EXPECTED THROUGH FRIDAY NIGHT AS NO SIGNIFICANT SYSTEMS ARE SET TO MOVE ACROSS THE CENTRAL PLAINS. AN UPPER LEVEL LOW WILL STAY FAIRLY STATIONARY OVER THE SOUTHWEST THROUGH FRIDAY...WHILE THE NORTHERN STREAM WILL KEEP NORTHWEST FLOW ACROSS THE AREA. THERE WILL BE AN APPROACHING SHORTWAVE TROUGH ON THURSDAY AS IT WILL BE MOVING OVER THE NORTHERN ROCKIES. THERE IS A BIT OF UNCERTAINTY ON HOW AMPLIFIED THIS SHORTWAVE TROUGH WILL BE...WHICH IMPACTS HOW STRONG THE SURFACE LOW WILL BECOME AND THEN HOW MUCH WARM AIR CAN BE PULLED NORTHWARD. TOOK A MIDDLE OF THE ROAD APPROACH FOR HIGH TEMPERATURES THURSDAY...WITH FORECAST HIGHS IN THE UPPER 50S AND 60S. IF THE SYSTEM BECOMES A BIT STRONGER...TEMPERATURES WILL LIKELY NEED TO BE RAISED FOR THURSDAY. THE COLD FRONT ASSOCIATED WITH THIS UPPER LEVEL SYSTEM WILL PASS ACROSS NEBRASKA THURSDAY AFTERNOON AND EVENING. ALTHOUGH THERE CONTINUES TO BE QUITE A BIT OF DISAGREEMENT IN MODEL SOLUTIONS ON WHERE THE MAIN ENERGY WITH THIS SYSTEM WILL PASS...IT DOES APPEAR FAIRLY CERTAIN THAT IT WILL BE WELL NORTH OF THE FORECAST AREA. WITH THE MAJORITY OF THE MOISTURE ACROSS THE NORTH STAYING NEAR THE LOW CENTER...FOR PRECIPITATION TO OCCUR WOULD NEED A MOISTURE SOURCE FROM THE SOUTH TO GET THIS TO HAPPEN AS THE FRONT MOVES THROUGH. HOWEVER THE UPPER LOW TO THE SOUTHWEST WILL LIKELY PROHIBIT MUCH MOISTURE TRANSPORT INTO THE AREA FROM THE SOUTH. ONE THING THAT DOES LOOK POSSIBLE IS STRONG WINDS THURSDAY NIGHT. WITH THE AREA STAYING IN A LOCATION WITH DRY AIR...WHEN THE AIRMASS BECOMES SUBSIDENT BEHIND THE FRONT...DOWNWARD MOTION WILL BE PROMOTED. ALTHOUGH TIMING IS NIGHT...WHICH ISN/T AS FAVORABLE FOR STRONGER WINDS...WILL NEED TO CONTINUE TO WATCH THIS TIME-FRAME IN THE NEXT FEW DAYS CONCERNING WINDS. THE MODELS REALLY BEGIN TO DIVERGE BEGINNING SATURDAY AS THEY SEEM TO BE HAVING PROBLEMS HANDLING THE SOUTHWEST UPPER LOW. ONE THING THEY DO ALL AGREE ON IS THAT STRONG RIDGING WILL BUILD IN...SOMEWHERE ACROSS THE WESTERN HALF OF THE COUNTRY INTO THE FIRST PART OF NEXT WEEK. DESPITE THE MODEL DIFFERENCES...THEY ALSO ARE INDICATING THE PATTERN ALOFT BECOMING MORE AMPLIFIED AND DIG A SHORTWAVE TROUGH SOUTH ALONG THE LEE-SIDE OF THE ROCKY MOUNTAINS OVER THE WEEKEND. CONTINUE TO HAVE PRECIPITATION CHANCES THROUGH MUCH OF THE WEEKEND...WITH BOTH RAIN AND SNOW LOOKING POSSIBLE. TEMPERATURE PROFILES SHOW PRECIPITATION TYPE AS RAIN ON SATURDAY...THEN SWITCHING TO RAIN/SNOW AND SNOW SATURDAY NIGHT...THEN BACK TO RAIN ON SUNDAY. THIS MAY NOT BE REAL LIKELY...AS THERE WON/T BE THAT GREAT AMOUNT OF TIME WITH RAIN AND SNOW...BUT WITH CONCERN OVER TIMING AND LOCATION OF THE PRECIPITATION...DID NOT HAVE THE CONFIDENCE YET TO NAIL DOWN A PARTICULAR PRECIPITATION TYPE. THE VERY END OF THE FORECAST PERIOD LOOKS INTERESTING...WITH A STRONG COLD FRONT TO PASS MONDAY NIGHT AND TUESDAY. DYNAMICS WITH THIS SYSTEM ARE PRETTY STRONG...WHICH COULD LEAD TO VERY WARM TEMPERATURES MONDAY...THEN CHANCES FOR PRECIPITATION MONDAY NIGHT AND TUESDAY...AND STRONG WINDS TUESDAY. DIDN/T GO TOO WARM WITH TEMPERATURES FOR MONDAY AT THIS TIME AS CONFIDENCE ON FORECASTING THE HIGHS THE DETERMINISTIC MODELS SHOW AT THIS TIME IS QUITE LOW...BUT IT BEARS WATCHING OVER THE COMING DAYS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 621 AM CDT TUE MAR 11 2014 AS A STORM SYSTEM MAKES ITS WAY THROUGH THE CENTRAL PLAINS...WIND 350-020 AT 17-27G30-35KT. BY 00Z...THE WIND IS EXPECTED TO LOSE ITS GUSTINESS WITH SUSTAINED WIND DECREASING TO 12KT. WIDESPREAD RAIN...CHANGING TO SNOW...IS EXPECTED IN NORTHERN NEBRASKA BY 14Z AND WILL SPREAD TO CENTRAL AND SOUTHWEST NEBRASKA BY 17Z. VISIBILITY AS LOW AS 1/2SM CAN BE EXPECTED WITH CEILING 700-1500 FEET AGL. SNOW WILL END BY LATE AFTERNOON. && .LBF WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 10 AM CDT /9 AM MDT/ THIS MORNING TO 8 PM CDT /7 PM MDT/ THIS EVENING FOR NEZ025>029-036>038-057>059-069>071. && $$ SHORT TERM...CDC LONG TERM...BROOKS AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1018 AM CDT TUE MAR 11 2014 .UPDATE... ISSUED AT 1018 AM CDT TUE MAR 11 2014 HAVE UPDATED TO CUT EXPECTED SNOW AMOUNTS...LARGELY FOR LACK OF COOLING BUT ALSO FOR LESS PRECIPITATION EXPECTED OVER OUR SOUTHEAST CORNER...THAT IS NORTHWEST IOWA AWAY FROM THE NORTHERN STATE BORDER. THE WEAKNESS OF THE COOLING IS ALLOWING ACCUMULATING SNOW TO FALL ONLY IN THE AREAS OF HEAVIER PRECIPITATION...AND THERE IS NOT MUCH OF THAT GOING TO BE LEFT. THE EXCEPTION IS FROM NORTH OF BROOKINGS INTO LINCOLN COUNTY MN WHERE THERE HAVE BEEN SOME ACCUMULATIONS ON ROADS...BUT EVEN THERE THE PRECIPITATION WILL MOVE OUT SOON. A REPORT FROM MARSHALL MINNESOTA INDICATED 0.37 INCH OF PRECIPITATION AND NO SNOW. HAVE ALSO CUT PRECIPITATION MENTION OUT FOR THIS EVENING FAR SOUTHEAST. TEMPERATURES WILL DO NOTHING EXCITING WITH THE CLOUD COVER AND STIFF NORTHERLY BREEZE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 424 AM CDT TUE MAR 11 2014 COMPLEX FORECAST TODAY AS A BAND OF PRECIPITATION MOVES SOUTHEAST ACROSS THE CWA. AS OF 4 AM THIS BAND IS ALONG AND NORTH OF HIGHWAY 14. THIS MATCHES WELL WITH A STRONG AREA OF MID LEVEL FRONTOGENESIS. DECENT INSTABILITY ABOVE THE FRONT...THUS NOT SURPRISED BY THE HIGH REFLECTIVITY CURRENTLY ON RADAR. BOUNDARY LAYER REMAINS QUITE WARM...AND THUS PRECIPITATION TYPE IS CURRENTLY RAIN. THIS FIRST AREA OF FRONTOGENESIS SHIFTS SOUTH THIS MORNING...BUT ALSO BEGINS TO WEAKEN. THIS OCCURS AS THE MAIN WAVE EJECTS OUT OF THE ROCKIES...WITH THE BEST QG FORCING SOUTH OF THE MISSOURI RIVER. THUS MAKES SENSE THAT WE SEE FRONTOGENESIS INTENSIFY AGAIN SOUTH OF INTERSTATE 90 AS MODELS SHOW. SO EXPECT WE SEE THE MODERATE TO HEAVY BAND ALONG HIGHWAY 14 SLOWLY WEAKEN THIS MORNING AS IT MOVES SOUTH...THEN INTENSIFY AGAIN THIS AFTERNOON SOUTH OF INTERSTATE 90 AS THE FRONT STRENGTHENS AND INTERACTS WITH THE UPPER WAVE. PRETTY LARGE UNCERTAINTY ON HOW MUCH THE BAND WEAKENS THIS MORNING...AND HOW QUICKLY IT INTENSIFIES THIS AFTERNOON. THIS IS IMPORTANT NOT ONLY FOR QPF...BUT ALSO PRECIPITATION TYPE. IF PRECIPITATION STAYS ON THE LIGHTER SIDE...IT WILL LIKELY STAY MAINLY RAIN. ONLY EXPECTING A CHANGEOVER TO SNOW DUE TO DYNAMIC COOLING IN THE HEAVIEST PRECIPITATION. SO IF THIS HEAVIER BAND WEAKENS ENOUGH...OUR SNOW FORECAST COULD BE IN TROUBLE. THE LATEST 06Z NAM AND HRRR AND RAP DO SHOW THIS MORE PRONOUNCED WEAKENING...SO WILL HAVE TO KEEP AN EYE ON THIS. EVEN AS THE BAND INTENSIFIES SOUTH OF INTERSTATE 90 THIS AFTERNOON...BOUNDARY LAYER COULD BE WARM ENOUGH TO KEEP THINGS RAIN...OR JUST A WET NON ACCUMULATING SNOW. SO FOR NOW...WILL KEEP 1 TO 2 INCHES IN THE FORECAST FOR MOST OF THE CWA...BUT WILL NEED TO MONITOR TEMPERATURE TRENDS THROUGH THE DAY. FOLLOWED CLOSE TO THE ARW AND NAM FOR TIMING...WITH THE BAND IMPACTING INTERSTATE 90 MID TO LATE MORNING...AND NORTHWEST IOWA LATE MORNING INTO THE AFTERNOON. SKIES WILL STAY MOSTLY CLOUDY TONIGHT...AND AS A SECONDARY WAVE DROP SOUTH...COULD SEE SOME SCATTERED SNOW SHOWERS DEVELOP AFTER MIDNIGHT. BASED ON LATEST MODEL RUNS DID SHIFT THIS SNOW SHOWER AREA FURTHER WEST FROM THE PREVIOUS FORECAST...CENTERED MORE BETWEEN THE JAMES RIVER AND INTERSTATE 29 CORRIDOR. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 424 AM CDT TUE MAR 11 2014 FOR THE MEDIUM RANGE...HAVE SIDED CLOSER TO A BLEND OF THE CANADIAN/GFS AND ECMWF. OPTED TO EXCLUDE THE NAM AS IT SEEMED TO BE THE OUTLIER IN TERMS OF THE PROGRESSION OF SYSTEMS AND SEEMED TO BE SLOWER THAN THE OTHER SOLUTIONS. MODELS SUGGEST BAND OF LIGHT SNOW SHOWERS EARLY ON WEDNESDAY THOUGH SATURATION IN THE DENDRITIC LAYER APPEARS TO BE A SIGNIFICANT ISSUE. MODEL SOUNDINGS VARY FROM SOLUTION TO SOLUTION...BUT IN GENERAL...ALL HINT AT ONLY A LIMITED AMOUNT OF THE DENDRITIC LAYER SATURATING AND WITH THE WARMER AIR BEGINNING TO RETURN IT APPEARS AS THOUGH THE CHANCE OF DEVELOPING THROUGHOUT THE MORNING DECREASES WITH TIME. HAVE KEPT LOW CHANCE POPS THROUGH THE EARLY MORNING HOURS...BUT DROPPED TO FLURRIES IN THE LATE MORNING IF ANYTHING IS LEFT BY THEN. EXPECT NICE WARMING WEDNESDAY INTO THURSDAY...HOWEVER STRATUS MAY LINGER AHEAD OF THE WARM FRONT ACROSS THE EASTERN CWA ON WEDNESDAY LIMITING WARMING POTENTIAL. WARMED HIGHS ON THURSDAY WITH CLEAR SKIES AND NICE SOUTHWEST FLOW ALOFT RESULTING IN 925 HPA TEMPS WARMING INTO THE 10-13C RANGE. COLD FRONT MOVES THROUGH THE AREA ON THURSDAY NIGHT. SHORT WAVE MOVES THROUGH MINNESOTA LATE THURSDAY NIGHT INTO FRIDAY. FOR THE MOST PART...IT APPEARS AS THOUGH THE WAVE IS FOCUSED EAST OF THE FORECAST AREA...SO LEFT FORECAST DRY FOR THE TIME BEING. BACK DOOR COLD FRONT MOVES INTO THE UPPER MIDWEST FRIDAY NIGHT. FRONT WORKS BACK TO THE WEST ON SATURDAY...WITH COOL NORTHEAST FLOW EAST OF THE FRONT. A SERIES OF SHORT WAVES APPEAR TO MOVE THROUGH THE AREA ON SATURDAY NEAR THE FRONT...POTENTIALLY CREATING SOME LIGHT RAIN/SNOW DEPENDING WHICH SIDE OF THE FRONT A PARTICULAR LOCATION IS ON. THE FRONT BEGINS TO SHIFT EAST ACROSS THE REGION ON SUNDAY LEADING TO A WARMING TREND. STRONG SOUTHERLY FLOW DEVELOPS ON MONDAY...LEADING A WARM BUT WINDY DAY. INCREASED WINDS ON MONDAY COMPARED TO THE GUIDANCE BUT MAY NOT HAVE INCREASED ENOUGH WITH 20-30 KNOTS OF FLOW THROUGH THE AFTERNOON HOURS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 637 AM CDT TUE MAR 11 2014 COMPLEX AND MESSY AVIATION DAY ACROSS THE AREA TODAY. AREA OF RAIN WILL SHIFT SOUTH ACROSS THE REGION TODAY...MIXING WITH SNOW AT TIMES. VISIBILITY IS GENERALLY VFR...BUT WOULD EXPECT DROPS INTO THE MVFR AND IFR RANGE WHEN AND IF SNOW MIXES IN. THE BAND OF PRECIPITATION IS EXPECTED TO INTENSIFY THIS AFTERNOON SOUTH OF INTERSTATE 90...THUS KSUX SEEMS TO HAVE TEH GREATEST POTENTIAL OF DROPPING INTO THE LIFR RANGE IN A HEAVIER SNOW BURST...ALTHOUGH CONFIDENCE IN THIS REMAINS PRETTY LOW. OTHERWISE IFR TO MVFR STRATUS IS CURRENTLY EXPANDING ACROSS MUCH OF THE AREA. EXPECT TO SEE A RETURN TO VFR BEHIND THE FRONT LATER TODAY FROM NORTH TO SOUTH...ALTHOUGH EXACTLY HOW QUICKLY THIS AFTERNOON AND EVENING IS UNCERTAIN. ANOTHER ROUND OF SCATTERED SNOW SHOWERS MAY ENTER THE AREA TOWARDS 12Z...WITH THE GREATEST CHANCE AROUND KHON. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE... SHORT TERM...CHENARD LONG TERM... AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
645 AM CDT TUE MAR 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 424 AM CDT TUE MAR 11 2014 COMPLEX FORECAST TODAY AS A BAND OF PRECIPITATION MOVES SOUTHEAST ACROSS THE CWA. AS OF 4 AM THIS BAND IS ALONG AND NORTH OF HIGHWAY 14. THIS MATCHES WELL WITH A STRONG AREA OF MID LEVEL FRONTOGENESIS. DECENT INSTABILITY ABOVE THE FRONT...THUS NOT SURPRISED BY THE HIGH REFLECTIVITY CURRENTLY ON RADAR. BOUNDARY LAYER REMAINS QUITE WARM...AND THUS PRECIPITATION TYPE IS CURRENTLY RAIN. THIS FIRST AREA OF FRONTOGENESIS SHIFTS SOUTH THIS MORNING...BUT ALSO BEGINS TO WEAKEN. THIS OCCURS AS THE MAIN WAVE EJECTS OUT OF THE ROCKIES...WITH THE BEST QG FORCING SOUTH OF THE MISSOURI RIVER. THUS MAKES SENSE THAT WE SEE FRONTOGENESIS INTENSIFY AGAIN SOUTH OF INTERSTATE 90 AS MODELS SHOW. SO EXPECT WE SEE THE MODERATE TO HEAVY BAND ALONG HIGHWAY 14 SLOWLY WEAKEN THIS MORNING AS IT MOVES SOUTH...THEN INTENSIFY AGAIN THIS AFTERNOON SOUTH OF INTERSTATE 90 AS THE FRONT STRENGTHENS AND INTERACTS WITH THE UPPER WAVE. PRETTY LARGE UNCERTAINTY ON HOW MUCH THE BAND WEAKENS THIS MORNING...AND HOW QUICKLY IT INTENSIFIES THIS AFTERNOON. THIS IS IMPORTANT NOT ONLY FOR QPF...BUT ALSO PRECIPITATION TYPE. IF PRECIPITATION STAYS ON THE LIGHTER SIDE...IT WILL LIKELY STAY MAINLY RAIN. ONLY EXPECTING A CHANGEOVER TO SNOW DUE TO DYNAMIC COOLING IN THE HEAVIEST PRECIPITATION. SO IF THIS HEAVIER BAND WEAKENS ENOUGH...OUR SNOW FORECAST COULD BE IN TROUBLE. THE LATEST 06Z NAM AND HRRR AND RAP DO SHOW THIS MORE PRONOUNCED WEAKENING...SO WILL HAVE TO KEEP AN EYE ON THIS. EVEN AS THE BAND INTENSIFIES SOUTH OF INTERSTATE 90 THIS AFTERNOON...BOUNDARY LAYER COULD BE WARM ENOUGH TO KEEP THINGS RAIN...OR JUST A WET NON ACCUMULATING SNOW. SO FOR NOW...WILL KEEP 1 TO 2 INCHES IN THE FORECAST FOR MOST OF THE CWA...BUT WILL NEED TO MONITOR TEMPERATURE TRENDS THROUGH THE DAY. FOLLOWED CLOSE TO THE ARW AND NAM FOR TIMING...WITH THE BAND IMPACTING INTERSTATE 90 MID TO LATE MORNING...AND NORTHWEST IOWA LATE MORNING INTO THE AFTERNOON. SKIES WILL STAY MOSTLY CLOUDY TONIGHT...AND AS A SECONDARY WAVE DROP SOUTH...COULD SEE SOME SCATTERED SNOW SHOWERS DEVELOP AFTER MIDNIGHT. BASED ON LATEST MODEL RUNS DID SHIFT THIS SNOW SHOWER AREA FURTHER WEST FROM THE PREVIOUS FORECAST...CENTERED MORE BETWEEN THE JAMES RIVER AND INTERSTATE 29 CORRIDOR. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 424 AM CDT TUE MAR 11 2014 FOR THE MEDIUM RANGE...HAVE SIDED CLOSER TO A BLEND OF THE CANADIAN/GFS AND ECMWF. OPTED TO EXCLUDE THE NAM AS IT SEEMED TO BE THE OUTLIER IN TERMS OF THE PROGRESSION OF SYSTEMS AND SEEMED TO BE SLOWER THAN THE OTHER SOLUTIONS. MODELS SUGGEST BAND OF LIGHT SNOW SHOWERS EARLY ON WEDNESDAY THOUGH SATURATION IN THE DENDRITIC LAYER APPEARS TO BE A SIGNIFICANT ISSUE. MODEL SOUNDINGS VARY FROM SOLUTION TO SOLUTION...BUT IN GENERAL...ALL HINT AT ONLY A LIMITED AMOUNT OF THE DENDRITIC LAYER SATURATING AND WITH THE WARMER AIR BEGINNING TO RETURN IT APPEARS AS THOUGH THE CHANCE OF DEVELOPING THROUGHOUT THE MORNING DECREASES WITH TIME. HAVE KEPT LOW CHANCE POPS THROUGH THE EARLY MORNING HOURS...BUT DROPPED TO FLURRIES IN THE LATE MORNING IF ANYTHING IS LEFT BY THEN. EXPECT NICE WARMING WEDNESDAY INTO THURSDAY...HOWEVER STRATUS MAY LINGER AHEAD OF THE WARM FRONT ACROSS THE EASTERN CWA ON WEDNESDAY LIMITING WARMING POTENTIAL. WARMED HIGHS ON THURSDAY WITH CLEAR SKIES AND NICE SOUTHWEST FLOW ALOFT RESULTING IN 925 HPA TEMPS WARMING INTO THE 10-13C RANGE. COLD FRONT MOVES THROUGH THE AREA ON THURSDAY NIGHT. SHORT WAVE MOVES THROUGH MINNESOTA LATE THURSDAY NIGHT INTO FRIDAY. FOR THE MOST PART...IT APPEARS AS THOUGH THE WAVE IS FOCUSED EAST OF THE FORECAST AREA...SO LEFT FORECAST DRY FOR THE TIME BEING. BACK DOOR COLD FRONT MOVES INTO THE UPPER MIDWEST FRIDAY NIGHT. FRONT WORKS BACK TO THE WEST ON SATURDAY...WITH COOL NORTHEAST FLOW EAST OF THE FRONT. A SERIES OF SHORT WAVES APPEAR TO MOVE THROUGH THE AREA ON SATURDAY NEAR THE FRONT...POTENTIALLY CREATING SOME LIGHT RAIN/SNOW DEPENDING WHICH SIDE OF THE FRONT A PARTICULAR LOCATION IS ON. THE FRONT BEGINS TO SHIFT EAST ACROSS THE REGION ON SUNDAY LEADING TO A WARMING TREND. STRONG SOUTHERLY FLOW DEVELOPS ON MONDAY...LEADING A WARM BUT WINDY DAY. INCREASED WINDS ON MONDAY COMPARED TO THE GUIDANCE BUT MAY NOT HAVE INCREASED ENOUGH WITH 20-30 KNOTS OF FLOW THROUGH THE AFTERNOON HOURS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 637 AM CDT TUE MAR 11 2014 COMPLEX AND MESSY AVIATION DAY ACROSS THE AREA TODAY. AREA OF RAIN WILL SHIFT SOUTH ACROSS THE REGION TODAY...MIXING WITH SNOW AT TIMES. VISIBILITY IS GENERALLY VFR...BUT WOULD EXPECT DROPS INTO THE MVFR AND IFR RANGE WHEN AND IF SNOW MIXES IN. THE BAND OF PRECIPITATION IS EXPECTED TO INTENSIFY THIS AFTERNOON SOUTH OF INTERSTATE 90...THUS KSUX SEEMS TO HAVE TEH GREATEST POTENTIAL OF DROPPING INTO THE LIFR RANGE IN A HEAVIER SNOW BURST...ALTHOUGH CONFIDENCE IN THIS REMAINS PRETTY LOW. OTHERWISE IFR TO MVFR STRATUS IS CURRENTLY EXPANDING ACROSS MUCH OF THE AREA. EXPECT TO SEE A RETURN TO VFR BEHIND THE FRONT LATER TODAY FROM NORTH TO SOUTH...ALTHOUGH EXACTLY HOW QUICKLY THIS AFTERNOON AND EVENING IS UNCERTAIN. ANOTHER ROUND OF SCATTERED SNOW SHOWERS MAY ENTER THE AREA TOWARDS 12Z...WITH THE GREATEST CHANCE AROUND KHON. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...CHENARD LONG TERM... AVIATION...CHENARD
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1101 AM CDT TUE MAR 11 2014 .UPDATE... LOW CLOUDS ALONG AND EAST OF I-35 WILL CONTINUE TO DISSIPATE THROUGH MIDDAY WITH GENERALLY MOSTLY SUNNY SKIES DURING THE AFTERNOON. SURFACE LOW PRESSURE NEAR GAGE OKLAHOMA WILL CONTINUE TO DEEPEN AND WINDS ACROSS THE REGION WILL INCREASE. STILL EXPECT A DRYLINE TO MOVE INTO THE WESTERN TWO TIER OF COUNTIES WITH BRISK SOUTHWEST TO WEST WINDS DURING THE AFTERNOON. DUE TO THE DRIER AIR OUT WEST AND AREA WINDS INCREASING...THE FIRE DANGER WILL BE HIGH GENERALLY WEST OF I-35/I-35E AND DOES WARRANT THE CURRENT GRASS FIRE DANGER STATEMENT. IF SUSTAIN WINDS INCREASE ABOVE 20 MPH FOR A FEW HOURS...THEN WE WOULD LIKELY UPGRADE TO A RED FLAG WARNING FOR SOME COUNTIES THROUGH THE REMAINDER OF THE AFTERNOON. ONE MAJOR FIRE WEATHER CONCERN WOULD BE IF A WILDFIRE STARTED JUST AHEAD OF FROPA. THIS WOULD CREATE A VERY DANGEROUS SITUATION FOR FIREFIGHTERS DURING INITIAL ATTACK AS THE FRONTAL WIND SHIFT WOULD SIGNIFICANTLY CHANGE THE FIRE/S MOVEMENT AND PROGRESSION. CURRENT WIND ADVISORY TIMING LOOKS GOOD AND WILL ONLY MODIFY ITS WORDING TO CLEARLY STATE THE TIMING OF THE FRONT AND ARRIVAL OF THE STRONG WINDS. 75 && .AVIATION... MID CLOUD HAS DISSIPATED OVER METROPLEX AND I CAN NOW SEE THE STRATUS. ONE PATCH OF IFR CLOUDS IS MOVING NORTH INTO THE SOUTHERN METROPLEX...AND HAVE ADDED A TEMPO FOR IFR CEILINGS THIS MORNING. WITH STRONG SOUTHWEST FLOW JUST ABOVE THE INVERSION...FEEL THAT WITH A BIT OF SUN THIS MORNING STRATUS WILL QUICKLY MIX OUT AND SKIES WILL REMAIN CLEAR REST OF THE TAF PERIOD. WACO IFR WILL BE MORE PERSISTENT AND TAKE A COUPLE OF MORE HOURS TO DISSIPATE...THEN THEY WILL ALSO REMAIN VFR FOR THE REST OF THE TAF PERIOD. STRONG COLD FRONT STILL PROGGED IN AROUND 10 PM/03Z FOR METROPLEX...AND IT IS MOVING FAST ENOUGH THAT WACO WILL SEE IT DURING THE SAME HOUR. WINDS WILL INCREASE SIGNIFICANTLY AN HOUR OR TWO AFTER FROPA...BUT FORTUNATELY THEY WILL BE FROM THE NORTH NORTHWEST AND NOT TOTALLY CROSS TO THE RUNWAYS. WINDS WILL LIKELY REMAIN STRONG THROUGH MORNING...AND SLOWLY DIMINISH WEDNESDAY BECOMING LIGHT AFTER SUNSET. 84 && .PREV UPDATE... .UPDATE... EARLY MORNING REGIONAL RADARS SHOWED SOME VERY LIGHT RAINFALL OVER CENTRAL TEXAS...EXTENDING AS FAR NORTH AS A HILLSBORO TO ATHENS LINE. THESE RAIN SHOWERS WERE ORIENTED ON THE NORTHERN PERIPHERY OF A VORTICITY LOBE ASSOCIATED WITH AN UPPER LOW...ROUGHLY CENTERED OVER AUSTIN ACCORDING TO 08Z WATER VAPOR SATELLITE IMAGERY. 08Z SURFACE ANALYSIS SHOWED MILD TEMPERATURES ACROSS NORTH AND CENTRAL TEXAS WITH MOST LOCATIONS HOLDING UP IN THE MID TO UPPER 50S. 08Z OBJECTIVE ANALYSIS SHOWED RELATIVELY STRONG LEE SIDE CYCLOGENESIS OVER THE SOUTHERN HIGH PLAINS WITH 3 HR PRESSURE FALLS OF AROUND 4 MB NEAR AN ELONGATED AREA OF LOW PRESSURE OF 997 MB OVER THE OK AND TX PANHANDLES. TODAY...THE PREVIOUS QUICK AFD WAS APPENDED BELOW. IN GENERAL OVER THE NEXT 24 TO 36 HRS THE REGION IS EXPECTED TO BE AFFECTED BY A DYNAMIC LOW PRESSURE SYSTEM WHICH WILL LEAD TO FIRE WEATHER DANGER AND STRONG WIND CONCERNS FOR NORTH AND CENTRAL TEXAS. THE PRIMARY UPPER LEVEL FEATURE DRIVING THESE CONDITIONS IS A STRONG SHORTWAVE TROUGH OBSERVED OVER UTAH...MOVING EAST-SOUTHEAST PER WATER VAPOR SATELLITE IMAGERY. 00Z UPPER AIR ANALYSIS OBSERVED A STRONG JET STREAK IN EXCESS OF 100 KTS AT THE 250 MB LEVEL AT THE BASE OF THIS TROUGH. THIS JET STREAK WAS LIKELY LOCATED OVER THE CENTRAL AND SOUTHERN CONUS ROCKIES EARLY THIS MORNING...AIDING IN THE STRONG LEE SIDE SURFACE CYCLOGENESIS OBSERVED ACROSS THE OK AND TX PANHANDLES. THE STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE EAST OVER THE CENTRAL PLAINS TODAY...DRIVING THE SURFACE CYCLONE EAST-SOUTHEAST TOWARDS NORTH TX THIS AFTERNOON. OUT AHEAD OF THE FRONT...WINDS ARE EXPECTED TO BECOME BREEZY AND SOUTH-SOUTHWESTERLY AT 15 TO 20 MPH. ALL GUIDANCE INDICATES AN H850 THERMAL RIDGE ORIENTED ALONG AND SOUTH OF THE SURFACE CYCLONE...BUT THE STRENGTH OF THE THERMAL RIDGE VARIES MODEL TO MODEL. HIGHER RESOLUTION MODEL GUIDANCE GENERALLY FAVORS A STRONGER THERMAL RIDGE...SO THE HIGH TEMPERATURE FORECAST FOR TODAY WAS BASED ON THE HIGH END OF THE SPECTRUM OF AVAILABLE GUIDANCE. WENT AHEAD WITH HIGHS JUST ABOVE 90 DEGREES NEAR BRECKENRIDGE AND GRAHAM...AND IN THE MID TO UPPER 80S FOR MOST LOCATIONS ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR. TO THE EAST...HIGHS WILL GENERALLY TOP OUT IN THE LOWER 80S TODAY...A BIT FARTHER REMOVED FROM THE DRIEST AIR AND STRONG THERMAL RIDGE NEAR THE SURFACE LOW. LOOKING AT FIRE WEATHER CONCERNS...ASSUMING HIGHS TOP OUT IN THE MID 80S TO JUST ABOVE 90 DEGREES WEST OF INTERSTATE 35 AS EXPECTED...GRASSY/FINE FUEL TEMPERATURES WILL GET QUITE WARM THIS AFTERNOON. WINDS OF 15 TO 20 MPH COMBINED WITH AFTERNOON RELATIVE HUMIDITY VALUES BELOW 30 PERCENT SUPPORT AT LEAST A HIGH FIRE WEATHER DANGER ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR...AND A GRASS FIRE DANGER STATEMENT HAS BEEN ISSUED FOR THESE LOCATIONS AS A RESULT. CRITICAL TO EXTREME FIRE WEATHER DANGER IS POSSIBLE THIS AFTERNOON...BUT DEPENDENT UP ON THE STRENGTH OF WINDS AND POSITION OF THE DRYLINE. MOST MODEL GUIDANCE KEEPS WINDS BELOW RED FLAG WARNING CRITERIA THIS AFTERNOON OVER THE WESTERN CWA. THIS IS PARTLY BECAUSE MODELS HAVE A PART OF THE ELONGATED SURFACE LOW PRESSURE LOCATED VERY NEAR WICHITA FALLS...GENERALLY REDUCING THE PRESSURE GRADIENT FORCE THAT WOULD OTHERWISE ACCELERATE WINDS THE ADDITIONAL 5 TO 10 MPH NECESSARY TO REACH RED FLAG WARNING CRITERIA. HOWEVER IF THE SURFACE LOW IS A BIT FARTHER NORTH...LIKE THE RAP AND HRRR ADVERTISED AT THE TIME OF THIS DISCUSSION...EXTREME FIRE WEATHER DANGER MAY BE REALIZED THIS AFTERNOON AND A RED FLAG WARNING MAY NEED TO BE ISSUED. THE HRRR IN PARTICULAR SHOWED A STRONG DRYLINE PUNCH INTO THE WESTERN CWA...WITH THE DRYLINE PUSHING AS FAR EAST AS A JACKSBORO TO LAMPASAS LINE BY 21Z. THE HRRR INCREASES WESTERLY WINDS AT THE SURFACE TO 20 TO 25 KTS...OR STRONG ENOUGH FOR CRITICAL/EXTREME FIRE DANGER WITH RELATIVE HUMIDITY VALUES CRASHING INTO THE SINGLE DIGITS WEST OF THE DRYLINE. IF THESE HRRR CONDITIONS ARE REALIZED...A RED FLAG WARNING WOULD CERTAINLY BE WARRANTED BECAUSE ANY GRASS-FIRE IGNITED WOULD BE VERY DIFFICULT...IF NOT IMPOSSIBLE...TO CONTROL. THIS IS DEFINITELY A WORST CASE SCENARIO...AND IS NOT SUPPORTED BY ANY OTHER GUIDANCE AT THIS TIME. REGARDLESS...THIS BEARS WATCHING CLOSELY THROUGHOUT THE DAY AS THE HRRR WAS ALSO THE MOST RECENT GUIDANCE AVAILABLE AT THE TIME OF THIS DISCUSSION. THIS EVENING AND OVERNIGHT...THE SURFACE CYCLONE WILL CONTINUE EAST THIS EVENING...WITH A STRONG COLD FRONT DROPPING SOUTH ACROSS THE REGION IN ITS WAKE. WHILE MODELS DO NOT AGREE ON THE EXACT TIMING OF THE FRONT YET...ALL MODELS AGREE THAT THE FRONT WILL BE VERY FAST MOVING ONCE IT CROSSES THE RED RIVER THIS EVENING. WINDS WILL SHIFT QUICKLY AROUND TO THE NORTH BEHIND THE FRONT...AND PICK UP TO AT LEAST 20 MPH GUSTING ABOVE 30 MPH JUST BEHIND ITS LEADING EDGE. WINDS ARE EXPECTED TO INCREASE IN INTENSITY BY ABOUT 10 MPH OR SO AN HOUR OR TWO BEHIND THE INITIAL FRONTAL PASSAGE. SUSTAINED WINDS OF 30 MPH...GUSTING TO 45 MPH AT TIMES ARE EXPECTED AT PEAK INTENSITY OVERNIGHT. CONFIDENCE IN STRONG WINDS IS VERY HIGH AT THIS TIME AS ALL MODEL GUIDANCE SHOWS AT LEAST A 50 KT JET AT THE 850 MB LEVEL OVER THE CWA BEHIND THE FRONT TONIGHT. HIGHER RESOLUTION GUIDANCE INDICATES 55 TO 60 KT JET FROM 09 TO 12Z OVER THE CWA WELL BEHIND THE FRONT. WENT AHEAD WITH A WIND ADVISORY FOR THE ENTIRE CWA FROM 10 PM THIS EVENING THROUGH 1 PM WEDNESDAY AS THIS APPEARED TO BE THE BEST WINDOW FOR NORTH WINDS EXCEEDING 25 MPH OR GUSTING ABOVE 40 MPH. THE START OR END TIMES OF THIS ADVISORY WILL LIKELY BE ADJUSTED BY LATER SHIFTS AS THE EXACT TIMING OF THE FRONT IS BETTER RESOLVED. WEDNESDAY AND THURSDAY...WEDNESDAY WILL START OFF WITH THE WIND ADVISORY STILL IN EFFECT AS NORTH WINDS HOLD UP AROUND 25 MPH GUSTING TO 40 MPH JUST AFTER SUNRISE...AND THEN SLOWLY DIMINISH TO AROUND 20 MPH JUST AFTER NOON. WEDNESDAY WILL BE MUCH COOLER WITH HIGHS GENERALLY HOLDING IN THE MID 50S WITH STRONG COLD AIR ADVECTION IN PLACE. SKIES ARE EXPECTED TO STAY MOSTLY SUNNY ON WEDNESDAY...WHICH WILL AT LEAST TAKE SOME OF THE BITE OUT OF THE COOL...BREEZY AIR. HOWEVER...WINDS ARE EXPECTED TO BECOME LIGHT AND VARIABLE BY EARLY THURSDAY MORNING...UNDER MOSTLY CLEAR SKIES. THIS WILL BRING MANY LOCATIONS DOWN BELOW FREEZING WEDNESDAY NIGHT...WITH THE EXCEPTION OF URBANIZED AREAS WHICH WILL STAY WARMER DUE TO THE ABSORPTION OF SUNSHINE THROUGHOUT THE DAY ON WEDNESDAY. LIGHT WINDS WILL BECOME SOUTHERLY ON THURSDAY AS TEMPERATURES WARM INTO THE 60S. FRIDAY AND FRIDAY NIGHT...MODELS CONTINUE TO INDICATE A RELATIVELY COMPACT BUT STRONG SHORTWAVE TROUGH WILL MOVE OVER NORTH TEXAS FRIDAY AFTERNOON OR EVENING. BOTH THE GFS AND ECMWF WERE ADVERTISING SOME LIGHT QPF AMOUNTS ASSOCIATED WITH THIS TROUGH WHICH IS DIFFERENT FROM PREVIOUS DAYS. THINK THE QPF AMOUNTS...ALTHOUGH LIGHT...ARE STILL OPTIMISTIC BECAUSE TONIGHT`S FRONT IS EXPECTED TO PLOW SOUTH ALL THE WAY ACROSS THE WESTERN GULF OF MEXICO...EFFECTIVELY STUNTING OUR PRIMARY MECHANISM TO RECHARGE THE LOWER TROPOSPHERE WITH WATER VAPOR. THE SHORTWAVE TROUGH ITSELF IS EXPECTED TO ORIGINATE FROM THE TROUGH THAT SENDS THE STRONG FRONT SOUTH ACROSS THE REGION TONIGHT. IT IS EXPECTED TO BREAK OFF THE MAIN TROUGH AND REMAIN QUASI-STEADY OVER THE SOUTHWESTERN CONUS FOR A COUPLE OF DAYS BEFORE MOVING EAST WITH THE NEXT NORTHERN STREAM SHORTWAVE TROUGH THURSDAY NIGHT INTO FRIDAY. THE ONLY REASON THIS MATTERS AT ALL IS BECAUSE IT IS NOT LIKELY TO BE ASSOCIATED WITH A PLUME OF SOUTHERN PACIFIC MOISTURE...SO THE ORIGIN OF THE RAPID MOISTENING OF THE GFS AND ECMWF OUT AHEAD OF THE TROUGH IS A BIT OF A MYSTERY AT THIS TIME. GRANTED...LIFT ASSOCIATED WITH THE TROUGH IS EXPECTED TO BE STRONG...SO DYNAMIC LIFT...COOLING AND SATURATION FROM THE BOTTOM UP...IS POSSIBLE. WENT AHEAD WITH SOME 20 POPS FRIDAY AFTERNOON AND EVENING ACROSS THE FAR EASTERN CWA DUE TO UNCERTAINTY REGARDING THE SOURCE REGION OF MOISTURE FOR THE GFS AND ECMWF POP/QPF FORECAST. IF MOISTURE IS JUST BEING UNDERESTIMATED IN GENERAL...POPS AND QPF MAY HAVE TO BE BUMPED WEST IN LATER FORECASTS. NEXT WEEKEND...A STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE FROM THE NORTHWEST CONUS SOUTHEAST TOWARDS THE SOUTHERN PLAINS DURING THIS TIME. THE GFS CONTINUES TO BRING THIS TROUGH OVER NORTH TX...OR JUST OFF TO THE SOUTHWEST. IN GENERAL...RESULTING IN A WETTER FORECAST THAN IF THE TROUGH REMAINS TO THE NORTH OF THE CWA. YESTERDAY THE OPERATIONAL GFS HAD ALMOST NO ENSEMBLE SUPPORT FOR THIS SOLUTION...SO IT WAS LARGELY DISCOUNTED. HOWEVER TODAY...ABOUT HALF OF THE GFS ENSEMBLE MEMBERS AGREE WITH THIS SOLUTION...AND THE OPERATIONAL CANADIAN AND ECMWF HAVE SORT OF COME ON BOARD AS WELL. /SORT OF/ IS USED BECAUSE THERE ARE SOME FAIRLY LARGE TIMING AND STRENGTH DISCREPANCIES BETWEEN THESE MODELS. HOWEVER THE FORECAST TRACK OF THE UPPER TROUGH SEEMS TO BE THE MAIN DIFFERENCE DICTATING A WET VERSUS DRY FORECAST...SO IT IS GOOD TO SEE MODELS TRENDING TOWARDS A MORE SOUTHERLY TRACK AT THIS TIME. QPF AMOUNTS ARE NOT VERY HIGH IN ANY OF THESE SOLUTIONS...MOSTLY BECAUSE IN ALL SOLUTIONS THE UPPER TROUGH IS POSITIVELY TILTED UNTIL IT MOVES EAST OF THE SOUTH PLAINS. BUT...BEGGARS CANT BE CHOOSERS...AND WE REALLY NEED SOME RAIN...SO WILL CONTINUE TO WATCH THE EVOLUTION OF THIS WEEKENDS TROUGH CLOSELY IN THE COMING DAYS AND HOPE FOR THE BEST. CAVANAUGH && .PREV DISCUSSION... /ISSUED 328 AM CDT TUE MAR 11 2014/ IN THE SHORT TERM FORECAST THERE ARE TWO PRIMARY CONCERNS: 1. FIRE WEATHER DANGER WEST OF INTERSTATE 35 THIS AFTERNOON. 2. STRONG WINDS BEHIND A COLD FRONT LATE THIS EVENING THROUGH WEDNESDAY MORNING. WITH REGARDS TO FIRE WEATHER DANGER: WILL HOLD OFF ON ISSUING A RED FLAG WARNING AT THIS TIME. FIRE WEATHER DANGER WILL BE HIGH TO VERY HIGH WEST OF INTERSTATE 35 THIS AFTERNOON. CRITICAL OR EXTREME FIRE WEATHER DANGER IS POSSIBLE FOR LOCATIONS GENERALLY ALONG AND WEST OF A JACKSBORO TO LAMPASAS LINE IF WINDS ARE STRONGER THAN FORECAST THIS AFTERNOON. LEVEL OF CONFIDENCE IN HIGH FIRE DANGER IS HIGH. LEVEL OF CONFIDENCE IN EXTREME FIRE WEATHER DANGER IS LOW. WITH REGARDS TO THE STRONG WINDS BEHIND A COLD FRONT TONIGHT. NORTH WINDS OF 25 TO 30 MPH...GUSTING TO 40 TO 45 MPH AT TIMES ARE EXPECTED BEHIND THE COLD FRONT THROUGH SUNRISE. WINDS WILL BEGIN TO DIMINISH IN INTENSITY FROM SUNRISE TO NOON ON WEDNESDAY. THE LEVEL OF CONFIDENCE IN THESE STRONG WINDS IS HIGH...THEREFORE A WIND ADVISORY WILL BE ISSUED FOR THE ENTIRE CWA FROM 10 PM THIS EVENING TO NOON ON WEDNESDAY. A FULL DISCUSSION INCLUDING REASONING AND THE REMAINDER OF THE FORECAST WILL BE ISSUED LATER THIS MORNING. CAVANAUGH && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 85 42 57 36 62 / 5 0 0 0 0 WACO, TX 82 41 58 33 60 / 5 0 0 0 0 PARIS, TX 80 41 54 32 61 / 0 0 0 0 0 DENTON, TX 85 39 57 31 63 / 5 0 0 0 0 MCKINNEY, TX 83 39 56 31 63 / 5 0 0 0 0 DALLAS, TX 84 43 57 38 62 / 5 0 0 0 0 TERRELL, TX 81 42 57 33 60 / 5 0 0 0 0 CORSICANA, TX 81 44 57 35 60 / 5 0 0 0 0 TEMPLE, TX 82 42 59 33 60 / 5 0 0 0 0 MINERAL WELLS, TX 88 38 56 33 62 / 0 0 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 10 PM THIS EVENING TO 1 PM CDT WEDNESDAY FOR TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175. && $$ /75
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1030 AM CDT TUE MAR 11 2014 .FIRE WEATHER... BIG CONCERN THIS AFTERNOON IS ON FIRE WEATHER POTENTIAL. DUE TO SOUTHWEST WINDS BEHIND A SURFACE TROUGH, OVERNIGHT RELATIVE HUMIDITY RECOVERIES WERE VERY POOR FOR LOCATIONS ON THE CAPROCK WITH RELATIVE HUMIDITY VALUES ONLY CLIMBING UP TO 35%. SEVERAL LOCATIONS EVEN STAYED BELOW 30% ALL NIGHT. RECOVERIES WERE SLIGHTLY HIGHER AHEAD OF THE SURFACE TROUGH ACROSS THE EASTERN PANHANDLES WHERE RELATIVE HUMIDITY VALUES RANGED BETWEEN 50 AND 80%. WHAT THIS ESSENTIALLY MEANS IS THAT FINE FUEL MOISTURE NEVER HAD A CHANCE TO MOISTEN AT ALL FOR MOST LOCATIONS OVERNIGHT. RELATIVE HUMIDITY VALUES WILL CONTINUE TO REMAIN VERY LOW FOR MUCH OF THE DAY UNTIL A COLD FRONT PASSES THROUGH LATER TODAY. SPEAKING OF THE COLD FRONT, IT CURRENTLY STRETCHES FROM NEAR HILL CITY, KS TO GARDEN CITY, KS TO SPRINGFIELD, CO. THIS FRONT WILL ENTER OUR FORECAST AREA AFTER 11 AM, AND MOVE SOUTHWARD THROUGH THE AFTERNOON. APPROXIMATE COLD FRONT TIMING: GUYMON: 1 PM DALHART AND PERRYTON: 1-2 PM DUMAS, BORGER, AND PAMPA: 3-4 PM AMARILLO: 4-5 PM SHAMROCK: 5-6 PM HEREFORD: 6-7 PM ONE OF THE BIGGEST QUESTION MARKS IS HOW STRONG WINDS WILL BE THIS AFTERNOON AHEAD OF THE FRONT. RAW RUC AND NAM SOUNDINGS SUGGEST MARGINAL WINDS FOR RED FLAG CONDITIONS IN OUR AREA. HOWEVER, PREFER THE HIGHER MET AND MAV WINDS (WHICH IS CURRENTLY IN THE FORECAST) AS MOS GUIDANCE TENDS TO DO RELATIVELY WELL ON THESE DOWNSLOPE WIND DAYS. WILL LEAVE THE RED FLAG WARNING IN TACT, BUT OUR HIGHEST CONFIDENCE FOR SEEING CRITICAL FIRE WEATHER CONDITIONS WILL BE SOUTH OF A CLAYTON TO CANADIAN LINE. THE ROLLER COASTER RIDE OF FUEL MOISTURE OVER THE LAST MONTH IS CLEARLY SEEN IN TEXAS FOREST SERVICE ENERGY RELEASE COMPONENT (ERC) DATA. AFTER LAST WEEK`S MOISTURE, WE HAVE QUICKLY DRIED OUT AGAIN. IN FACT, FORECAST ERC VALUES TODAY ARE 67 AT BOOTLEG, 62 AT CEDAR, AND 60 AT WHEELER. THESE VALUES ARE GETTING VERY CLOSE TO THE 90% PERCENTILE, AT WHICH LOCAL RESEARCH SUGGESTS SIGNIFICANT FIRE POTENTIAL BECOMES AN INCREASING CONCERN. WITH THESE DRYING FUELS AND A LITTLE MORE FAVORABLE FIRE WEATHER CONDITIONS, IT`S NOT A BIG SURPRISE THAT WE SAW A SLIGHT UPTICK IN INITIAL ATTACK ACTIVITY YESTERDAY. TFS SIGNIFICANT FIRE POTENTIAL MATRICES SHOW A MODERATE TO NEAR HIGH POTENTIAL FOR SIGNIFICANT FIRE TODAY, ESPECIALLY ACROSS THE FAR SOUTHWESTERN TEXAS PANHANDLE. THE AXIS OF A BROAD 850 MB THERMAL RIDGE WILL STRETCH FROM NORTHEASTERN NEW MEXICO INTO THE SOUTHWESTERN TEXAS PANHANDLE INTO THE SOUTH PLAINS. THE ALIGNMENT OF THE STRONGEST LOW-/MID-LEVEL WINDS WILL GENERALLY OCCUR ALONG AND SOUTH OF THIS AXIS. IT IS ALSO IN THESE LOCATIONS THAT TEMPERATURES WILL BE 5 TO 15 DEGREES ABOVE NORMAL, WHICH ALSO SUPPORTS HIGHER FIRE DANGER PER LOCAL RESEARCH. THEREFORE, BASED ON FUELS AND WEATHER, THE HIGHEST PROBABILITIES (AND THEY ARE STILL ON THE LOW SIDE) OF SIGNIFICANT FIRE WEATHER POTENTIAL WILL REMAIN SOUTH AND WEST OF A HEREFORD TO HAPPY LINE. DESPITE THIS, FIRE OFFICIALS AND EMERGENCY MANAGERS SHOULD REMAIN ON HEIGHTENED ALERT, ESPECIALLY CONSIDERING THAT WINDS WILL SHIFT FROM THE NORTHWEST TO THE NORTH AND INCREASE SUBSTANTIALLY (GUSTS UP TO 60 MPH) BEHIND THE COLD FRONT LATER THIS AFTERNOON AND EVENING. THIS WILL BE OF UTMOST IMPORTANCE IN THE EVENT OF ANY FIRE STARTS OR ONGOING FIRES BEFORE THEN! JACKSON && .PREV DISCUSSION... /ISSUED 641 AM CDT TUE MAR 11 2014/ AVIATION... 12Z TAFS...WEST WINDS INITIALLY THIS MORNING WILL VEER TO THE NORTHWEST BY MID TO LATE MORNING AND INCREASE TO 20-25 KTS WITH GUSTS OF 30-35 KTS. A COLD FRONT WILL WORK SOUTH THROUGH THE AREA THIS AFTERNOON...WITH WINDS TURNING TO THE NORTH BEHIND THE FRONT AND INCREASING TO NEAR 35 KTS WITH GUSTS TO AROUND 50 KTS POSSIBLE. SOME VSBY REDUCTIONS WILL BE POSSIBLE FROM BLDU BEHIND THE FRONT THIS AFTERNOON AND EVENING. WINDS WILL DECREASE FROM NORTH TO SOUTH LATE THIS EVENING AND OVERNIGHT. OUTSIDE OF ANY BLDU...VFR CONDITIONS ARE EXPECTED. AN AVIATION WEATHER WARNING IS IN EFFECT FOR KAMA FROM 22Z TODAY THROUGH 06Z WEDNESDAY FOR THE STRONG WINDS. KB PREV DISCUSSION... /ISSUED 406 AM CDT TUE MAR 11 2014/ DISCUSSION... UPPER LEVEL SHORT WAVE TROUGH OVER WYOMING NOW WILL ELONGATE AND SPLIT AS IT DIVES SOUTH THROUGH COLORADO AND KANSAS TODAY. A POWERFUL COLD FRONT WILL BLAST ITS WAY SOUTH ACROSS THE PANHANDLES THIS AFTERNOON AND EVENING IN ASSOCIATION WITH THE PASSAGE OF THE SHORT WAVE TROUGH. SURFACE PRESSURE GRADIENT IS VERY TIGHT BETWEEN LOW PRESSURE OVER NORTH CENTRAL TEXAS AND HIGH PRESSURE OVER WYOMING BY LATE THIS AFTERNOON AND EARLY THIS EVENING. THIS TIGHT PRESSURE GRADIENT IS EXPECTED TO BRING NORTH WINDS OF 30 TO 40 MILES AN HOUR ACROSS THE PANHANDLES WITH GUST TO AROUND 60 MILES AN HOUR IN SOME SPOTS. HAVE GONE AHEAD AND TURNED THE HIGH WIND WATCH INTO A HIGH WIND WARNING FOR MUCH OF THE CWA. ONLY THE FAR EAST CENTRAL AND SOUTHEAST TEXAS PANHANDLE WILL BE IN A WIND ADVISORY. BLOWING DUST MAY ALSO REDUCE VISIBILITIES TO ONE MILE OR LESS AT TIMES. RED FLAG WARNING CRITERIA IS ALSO EXPECTED TO BE MET ACROSS THE CWA TODAY AS RELATIVE HUMIDITY VALUES DROP TO 15 PERCENT OR BELOW AHEAD AND JUST BEHIND THE COLD FRONT. THE WIND SHIFT AND SUDDEN INCREASE IN THE WIND WILL ALSO CAUSE UNPREDICTABLE FIRE BEHAVIOR SHOULD A FIRE START. WINDS WILL SLOWLY DECREASE AFTER MIDNIGHT AND SHOULD BE BELOW 20 MPH BY MID MORNING ON WEDNESDAY. THE MODELS STILL WANT TO PAINT SOME VERY LIGHT QPF...MAINLY ACROSS THE NORTHERN CWA...THURSDAY NIGHT INTO FRIDAY IN ASSOCIATION WITH THE SECOND SHORT WAVE TROUGH APPROACHING FROM THE WEST. FOR NOW WILL LEAVE THE FORECAST DRY AS IT LOOKS LIKE MOISTURE WILL BE LACKING. THE NEXT SYSTEM TO AFFECT THE PANHANDLES WILL ARRIVE BY THE SECOND HALF OF THE WEEKEND. THIS SYSTEM SLIDES SOUTHEAST ON THE EAST SIDE OF A WEST COAST RIDGE AND IT INTENSIFIES AS IT MOVES INTO THE SOUTHERN HIGH PLAINS. AGAIN...THE MODELS WANT CHANGE THEIR TUNE SINCE IT IS A NEW DAY. THEREFORE...WILL NOT INSERT ANY PRECIP FOR LATE NEXT WEEKEND AT THIS TIME. FIRE WEATHER... CRITICAL FIRE WEATHER CONDITIONS WILL BE FOUND ACROSS THE PANHANDLES TODAY AND THIS EVENING. LOWEST AFTERNOON RELATIVE HUMIDITY VALUES WILL GET DOWN INTO THE 5 TO 15 PERCENT RANGE ACROSS MUCH OF THE PANHANDLES. RELATIVE HUMIDITY VALUES WILL START TO RECOVER SOME BEHIND A COLD ACROSS THE OKLAHOMA PANHANDLE AND THE NORTHERN TEXAS PANHANDLE BY MID AFTERNOON... BUT WINDS WILL BE INCREASING BEHIND THE COLD FRONT SO ANY ONGOING FIRES COULD HAVE ERRATIC BEHAVIOR DUE TO THE SHIFTING WINDS WITH THE FRONT. WINDS WILL DECREASE SLOWLY AFTER MIDNIGHT TONIGHT AND THEY WILL BE BELOW 15 MPH BY AROUND MID MORNING ON WEDNESDAY. ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS THE PANHANDLES AGAIN ON THURSDAY AS SOUTHWEST WINDS INCREASE AND RELATIVE HUMIDITY VALUES DROP. && .AMA WATCHES/WARNINGS/ADVISORIES... TX...HIGH WIND WARNING FROM 1 PM THIS AFTERNOON TO 1 AM CDT WEDNESDAY FOR THE FOLLOWING ZONES: CARSON...DALLAM...DEAF SMITH... GRAY...HANSFORD...HARTLEY...HUTCHINSON...LIPSCOMB...MOORE... OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...SHERMAN. RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL... HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM... POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER. WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 1 AM CDT WEDNESDAY FOR THE FOLLOWING ZONES: ARMSTRONG...COLLINGSWORTH...DONLEY... HEMPHILL...WHEELER. OK...HIGH WIND WARNING FROM 1 PM THIS AFTERNOON TO 1 AM CDT WEDNESDAY FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS. RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS. && $$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
700 AM CDT TUE MAR 11 2014 .AVIATION... GUSTY WEST TO NORTHWEST WINDS ARE EXPECTED FOR MOST OF THE DAY TODAY. PATCHY BLDU MAY CAUSE LOCAL VSBY REDUCTIONS. THIS EVENING...A STRONG COLD FRONT WILL QUICKLY PASS THROUGH THE AREA. SUSTAINED WIND SPEEDS COULD APPROACH 30 KTS AT EITHER OR BOTH TERMINALS AND REQUIRE AN AIRPORT WEATHER WARNING. ALSO...THERE WILL LIKELY BE A PERIOD OF HIGHER DUST CONCENTRATIONS WHICH COULD RESULT IN MVFR VSBYS AT KLBB. WINDS WILL SLOWLY DECREASE WEDNESDAY MORNING AND THE DUST WILL SETTLE. VFR CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE FORECAST. && .PREV DISCUSSION... /ISSUED 403 AM CDT TUE MAR 11 2014/ SHORT TERM... THE STAGE IS SET FOR A EARLY SPRING STRONG WIND/BLOWING DUST AND FIRE WEATHER EVENT TODAY AND TONIGHT. 3 AM SAT IMAGERY AND UPPER-AIR ANALYSIS SHOW A SHARP SHORTWAVE MOVING QUICKLY THROUGH THE INTER-MOUNTAIN WEST. THIS WAVE WILL MOVE ROUGHLY EWD INTO THE CENTRAL PLAINS TODAY...PLACING THE CWA ON THE SRN FLANK OF THE MID-LVL JET MAX WITHIN THE BASE OF THE TROUGH. IN ADDITION...A WEAK SFC TROUGH EXTENDING SWD FROM A LOW IN FAR NE COLO THROUGH THE WRN PANHANDLES INTO ERN NM WILL DEEPEN AND MOVE EAST TODAY. TIGHTENING THE SFC PRESSURE GRADIENT WHILE WINDS SWING AROUND TO THE WEST THEN W-NW. FINALLY...A STRONG COLD FRONT IS MOVING INTO NRN COLO AND WRN NE...THIS FRONT WILL BE THE MAIN DRIVER OF STRONG WINDS THIS EVENING/TONIGHT...MORE ON THAT LATER. WINDS ARE EXPECTED TO PICK UP PRETTY QUICKLY THIS MORNING...THE WEST TEXAS SODAR AT REESE CENTER ALREADY SHOWS 30+ KTS AT 500 FT AGL. WHILE WE DO HAVE SOME SHALLOW MOISTURE IN PLACE ACROSS THE ERN CWA THIS MORNING...UNFORTUNATELY...THIS MOISTURE WILL BE SCOURED OUT QUICKLY AND CRITICAL FIRE WEATHER CONDITIONS COULD DEVELOP BEFORE NOON /SEE DISCUSSION BELOW/. IN GENERAL...WE EXPECT WINDS TO RISE INTO THE 25 TO 35 MPH RANGE ACROSS THE AREA TODAY...SLIGHTLY LOWER IN THE ROLLING PLAINS AND SLIGHTLY MORE ACROSS THE W-SW. THESE WINDS WILL LIKELY REMAIN JUST BELOW ADVISORY LEVELS BUT SHOULD BE SUFFICIENT TO LOFT SOME PATCHY BLOWING DUST. TEMPS WILL BE QUITE WARM FOR MOST OF THE AREA...WITH HIGHS IN THE 80S...PERHAPS PUSHING 90F IN THE SRN ROLLING PLAINS...WHILE CAA COMING IN FROM THE NW SHOULD KEEP TEMPS IN THE 70S ACROSS THE FAR SW TX PANHANDLE AND WRN SPLNS. LATE THIS AFTERNOON...ATTENTION WILL TURN TO THE COLD FRONT WHICH IS EXPECTED TO BE BARRELING SOUTH THROUGH THE PANHANDLES. WHILE GUIDANCE IS IN GOOD AGREEMENT THAT THE FRONT/S PROGRESS WILL BE QUICKER IN THE EAST...LAGGING IN THE WEST...THERE IS STILL A FEW HOURS OF DISAGREEMENT IN THE TIMING OF THE FRONT. WE ARE FAVORING THE HIGH-RES GUIDANCE FROM THE RAP AND THE TTU-WRF...WHICH SHOWS THE FRONT ENTERING CHILDRESS COUNTY AROUND 23 UTC...AND PARMER COUNTY AROUND 00 UTC. BUT OF COURSE THE ACTUAL FROPA COULD VARY A COUPLE HOURS EITHER WAY. AS NOTED PREVIOUSLY...MODELS ARE SHOWING VERY IMPRESSIVE PRESSURE RISES BEHIND THE FRONT THIS EVENING. OBJECTIVE GUIDANCE SUGGESTS THAT WIND SPEEDS COULD REACH HIGH WIND CRITERIA /SUSTAINED SPEED OF AT LEAST 40 MPH AND/OR GUSTS IN EXCESS OF 57 MPH/ ACROSS THE NRN HALF OF THE FA. WE ARE A LITTLE SKEPTICAL THAT WE WILL SEE SUSTAINED HIGH WINDS IN THE LOWER TERRAIN OF THE ROLLING PLAINS...BUT WE ARE PLANNING ON EXTENDING THE HIGH WIND WATCH SOUTH AND EAST ACROSS MUCH OF THE CAPROCK....WITH SOLID ADVISORY-LEVEL WINDS EXPECTED ELSEWHERE. SOMEWHAT INTERESTINGLY...THERE IS A PRONOUNCED WEAKNESS PROGGED IN THE 800-700MB WIND FIELD ACROSS MUCH OF OUR AREA AROUND 0Z. THIS SHOULD NOT HAVE MUCH OF AN IMPACT ON THE OVERALL FCST BUT DEPENDING ON THE TIMING OF THE FRONT...IT COULD LEAD TO A SHORT-DURATION LULL IN GUSTY WINDS BEFORE A BIG INCREASE WITH THE FROPA. AS FOR BLOWING DUST...WE ARE LOOKING FOR A CONCENTRATION OF DIRT AND REDUCTION IN VISIBILITY ALONG AND IMMEDIATELY IN THE WAKE OF THE FRONT...BUT WE DON/T HAVE ANY STRONG INDICATIONS AT THIS TIME THAT VISIBILITIES WILL DROP TO ADVISORY OR DUST STORM LEVELS. THIS IS PARTLY DUE TO THE WIND DIRECTION AND OUR EXPECTATION THAT THE FRONT WILL MOVE THROUGH AFTER PEAK MIXING. IF THE FRONT IS FASTER/STRONGER THAN EXPECTED...THEN DENSE BLOWING DUST MAY BE A GREATER CONCERN. LONG TERM... AFTER THE ACTIVE SHORT TERM...THE EXTENDED FORECAST SEEMS RELATIVELY BENIGN BY COMPARISON. GUSTY NORTHERLY WINDS EARLY WEDNESDAY WILL GRADUALLY WEAKEN THROUGH THE DAY AS THE PRESSURE GRADIENT RELAXES AND SURFACE RIDGING SETTLES SQUARELY OVER WEST TEXAS. IT WILL BE CONSIDERABLY COOLER BEHIND THIS EVENINGS FROPA...WITH HIGHS ON WEDNESDAY TOPPING OUT AROUND 10 DEGREES BELOW MID-MARCH AVERAGES. SHORTWAVE RIDGING ALOFT WILL FOLLOW ON THURSDAY WHICH WHEN COUPLED WITH RETURN FLOW ON THE BACK SIDE OF THE DEPARTING SURFACE RIDGE AND RENEWED SURFACE TROUGHING IN THE LEE OF THE ROCKIES WILL MEAN BREEZY SOUTHERLY WINDS WITH TEMPERATURES RECOVERING TO NEAR AVERAGE. ATTENTION WILL THEN TURN WEST TO A CUTOFF UPPER LOW THAT WILL HANG OUT OVER THE GREAT BASIN MID-WEEK. THIS UPPER LOW WILL GET KICKED EASTWARD LATE WEEK AS JET ENERGY MOVES INTO THE PACIFIC NORTHWEST. THERE REMAINS SOME TIMING DIFFERENCES...BUT WHAT IS LEFT OF THE UPPER LOW WILL RACE ACROSS THE SOUTH PLAINS FRIDAY OR FRIDAY NIGHT. UNFORTUNATELY...THIS SYSTEM WILL NOT HAVE MUCH IN THE WAY OF LOW-LEVEL MOISTURE TO WORK WITH...BUT THE GFS AND ECMWF DO CONTINUE TO PAINT POCKETS OF VERY LIGHT QPF SOMEWHERE IN OR NEAR THE CWA. GIVEN THIS SIGNAL...WE WOULD NOT BE SURPRISED TO SEE A FEW SPRINKLES OR LIGHT SHOWERS...BUT THE CHANCE OF MEASURABLE RAIN STILL APPEARS LOW AND WE HAVE MAINTAINED POPS AROUND 10 PERCENT. THE TIMING UNCERTAINTY WITH THE PASSING WAVE DOES ALSO CREATE LOWER CONFIDENCE ON WHEN THE ASSOCIATED FROPA WILL OCCUR. A QUICKER SYSTEM/FRONT COULD MEAN TEMPERATURES A LITTLE COOLER THAN WHAT IS CURRENTLY DEPICTED IN THE FORECAST...THOUGH EITHER WAY THE SYSTEM WILL NOT HAVE MUCH COOL AIR TO WORK WITH. THE FIRST HALF OF THE WEEKEND WILL START OUT ON THE MILD SIDE...WITH HIGHS EXPECTED TO TOP OUT IN THE 60S AND LOWER 70S. HOWEVER...A SHORTWAVE TROUGH IS PROGGED TO DIVE SOUTH-SOUTHEASTWARD TOWARD THE REGION SATURDAY NIGHT. AT A MINIMUM...THIS DISTURBANCE SHOULD HELP DRIVE A DECENT COLD FRONT THROUGH...DROPPING TEMPERATURES BACK BELOW AVERAGE FOR THE SECOND HALF OF THE WEEKEND. LESS CERTAIN IS EXACTLY WHAT LONGITUDE THIS DISTURBANCE PASSES AND THUS WHETHER OR NOT IT CAN BRING A WINDOW FOR PRECIPITATION CHANCES TO THE SOUTH PLAINS. THE MOST RECENT ECMWF HAS TRENDED BACK FURTHER WEST AND WETTER...WHILE THE GFS TRACK IS MORE EASTWARD WHICH WOULD LIKELY BE DRY FOR THE SOUTH PLAINS. WE HAVE MAINTAINED SILENT POPS AROUND 10 PERCENT FOR NOW AND WILL WAIT TO MAKE A MOVE ONE WAY OR THE OTHER UNTIL THE NWP CAN COME INTO BETTER AGREEMENT. REGARDLESS...WARMER AND DRY WEATHER SHOULD KICK OFF EARLY NEXT WEEK AS THE UPPER TROUGH DEPARTS AND SOUTHERLY TO SOUTHWESTERLY SURFACE FLOW REDEVELOPS. FIRE WEATHER... LATEST INDICATIONS ARE THAT CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP ACROSS THE ENTIRE SOUTH PLAINS AREA TODAY AND WE WILL EXPAND AND UPGRADE THE WATCH TO A RED FLAG WARNING FOR OUR WHOLE CWA. DESPITE HIGH RH VALUES ACROSS THE EASTERN SOUTH PLAINS AND ROLLING PLAINS EARLY THIS MORNING...VERY DRY AIR WILL SPREAD EAST RESULTING IN RH VALUES DROPPING UNDER 15 PERCENT BY 10 AM FOR MANY AREAS...AND INTO THE SINGLE DIGITS ACROSS THE ENTIRE AREA THIS AFTERNOON. WHILE WIND SPEEDS MAY BE ON THE LOW END OF CRITERIA ACROSS THE ERN ROLLING PLAINS...IT APPEARS THAT WIND SPEEDS AND RH VALUES WILL SUPPORT AN EXTREMELY CRITICAL DANGER FOR MUCH OF THE SOUTHWEST AND SOUTHERN SOUTH PLAINS. WINDS MAY RELAX FOR A PERIOD AROUND 6 TO 7 PM...BUT THE PASSAGE OF A STRONG COLD FRONT IN THE EVENING WILL BRING AN ABRUPT WIND SHIFT TO THE NORTH AND MUCH STRONGER WINDS SPEEDS. ALTHOUGH COOLING TEMPS AND RISING RH VALUES WILL BEGIN TO REDUCE THE FIRE DANGER...WE WILL KEEP THE RED FLAG WARNING GOING THROUGH 9 PM CDT DUE TO THIS STRONG FRONT. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 71 25 52 24 60 / 0 0 0 0 0 TULIA 76 28 54 25 63 / 0 0 0 0 0 PLAINVIEW 77 29 55 26 63 / 0 0 0 0 0 LEVELLAND 78 30 54 26 63 / 0 0 0 0 0 LUBBOCK 81 32 56 29 64 / 0 0 0 0 0 DENVER CITY 80 31 55 25 61 / 0 0 0 0 0 BROWNFIELD 81 33 56 26 63 / 0 0 0 0 0 CHILDRESS 83 34 58 31 65 / 0 0 0 0 0 SPUR 85 35 58 30 65 / 0 0 0 0 0 ASPERMONT 88 36 58 29 65 / 0 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 11 AM THIS MORNING TO 10 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: TXZ021>044. WIND ADVISORY FROM 7 PM THIS EVENING TO 3 AM CDT WEDNESDAY FOR THE FOLLOWING ZONES: TXZ021>044. && $$ 33/23
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
624 AM CDT TUE MAR 11 2014 .AVIATION... MID CLOUD HAS DISSIPATED OVER METROPLEX AND I CAN NOW SEE THE STRATUS. ONE PATCH OF IFR CLOUDS IS MOVING NORTH INTO THE SOUTHERN METROPLEX...AND HAVE ADDED A TEMPO FOR IFR CEILINGS THIS MORNING. WITH STRONG SOUTHWEST FLOW JUST ABOVE THE INVERSION...FEEL THAT WITH A BIT OF SUN THIS MORNING STRATUS WILL QUICKLY MIX OUT AND SKIES WILL REMAIN CLEAR REST OF THE TAF PERIOD. WACO IFR WILL BE MORE PERSISTENT AND TAKE A COUPLE OF MORE HOURS TO DISSIPATE...THEN THEY WILL ALSO REMAIN VFR FOR THE REST OF THE TAF PERIOD. STRONG COLD FRONT STILL PROGGED IN AROUND 10 PM/03Z FOR METROPLEX...AND IT IS MOVING FAST ENOUGH THAT WACO WILL SEE IT DURING THE SAME HOUR. WINDS WILL INCREASE SIGNIFICANTLY AN HOUR OR TWO AFTER FROPA...BUT FORTUNATELY THEY WILL BE FROM THE NORTH NORTHWEST AND NOT TOTALLY CROSS TO THE RUNWAYS. WINDS WILL LIKELY REMAIN STRONG THROUGH MORNING...AND SLOWLY DIMINISH WEDNESDAY BECOMING LIGHT AFTER SUNSET. 84 && .UPDATE... EARLY MORNING REGIONAL RADARS SHOWED SOME VERY LIGHT RAINFALL OVER CENTRAL TEXAS...EXTENDING AS FAR NORTH AS A HILLSBORO TO ATHENS LINE. THESE RAIN SHOWERS WERE ORIENTED ON THE NORTHERN PERIPHERY OF A VORTICITY LOBE ASSOCIATED WITH AN UPPER LOW...ROUGHLY CENTERED OVER AUSTIN ACCORDING TO 08Z WATER VAPOR SATELLITE IMAGERY. 08Z SURFACE ANALYSIS SHOWED MILD TEMPERATURES ACROSS NORTH AND CENTRAL TEXAS WITH MOST LOCATIONS HOLDING UP IN THE MID TO UPPER 50S. 08Z OBJECTIVE ANALYSIS SHOWED RELATIVELY STRONG LEE SIDE CYCLOGENESIS OVER THE SOUTHERN HIGH PLAINS WITH 3 HR PRESSURE FALLS OF AROUND 4 MB NEAR AN ELONGATED AREA OF LOW PRESSURE OF 997 MB OVER THE OK AND TX PANHANDLES. TODAY...THE PREVIOUS QUICK AFD WAS APPENDED BELOW. IN GENERAL OVER THE NEXT 24 TO 36 HRS THE REGION IS EXPECTED TO BE AFFECTED BY A DYNAMIC LOW PRESSURE SYSTEM WHICH WILL LEAD TO FIRE WEATHER DANGER AND STRONG WIND CONCERNS FOR NORTH AND CENTRAL TEXAS. THE PRIMARY UPPER LEVEL FEATURE DRIVING THESE CONDITIONS IS A STRONG SHORTWAVE TROUGH OBSERVED OVER UTAH...MOVING EAST-SOUTHEAST PER WATER VAPOR SATELLITE IMAGERY. 00Z UPPER AIR ANALYSIS OBSERVED A STRONG JET STREAK IN EXCESS OF 100 KTS AT THE 250 MB LEVEL AT THE BASE OF THIS TROUGH. THIS JET STREAK WAS LIKELY LOCATED OVER THE CENTRAL AND SOUTHERN CONUS ROCKIES EARLY THIS MORNING...AIDING IN THE STRONG LEE SIDE SURFACE CYCLOGENESIS OBSERVED ACROSS THE OK AND TX PANHANDLES. THE STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE EAST OVER THE CENTRAL PLAINS TODAY...DRIVING THE SURFACE CYCLONE EAST-SOUTHEAST TOWARDS NORTH TX THIS AFTERNOON. OUT AHEAD OF THE FRONT...WINDS ARE EXPECTED TO BECOME BREEZY AND SOUTH-SOUTHWESTERLY AT 15 TO 20 MPH. ALL GUIDANCE INDICATES AN H850 THERMAL RIDGE ORIENTED ALONG AND SOUTH OF THE SURFACE CYCLONE...BUT THE STRENGTH OF THE THERMAL RIDGE VARIES MODEL TO MODEL. HIGHER RESOLUTION MODEL GUIDANCE GENERALLY FAVORS A STRONGER THERMAL RIDGE...SO THE HIGH TEMPERATURE FORECAST FOR TODAY WAS BASED ON THE HIGH END OF THE SPECTRUM OF AVAILABLE GUIDANCE. WENT AHEAD WITH HIGHS JUST ABOVE 90 DEGREES NEAR BRECKENRIDGE AND GRAHAM...AND IN THE MID TO UPPER 80S FOR MOST LOCATIONS ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR. TO THE EAST...HIGHS WILL GENERALLY TOP OUT IN THE LOWER 80S TODAY...A BIT FARTHER REMOVED FROM THE DRIEST AIR AND STRONG THERMAL RIDGE NEAR THE SURFACE LOW. LOOKING AT FIRE WEATHER CONCERNS...ASSUMING HIGHS TOP OUT IN THE MID 80S TO JUST ABOVE 90 DEGREES WEST OF INTERSTATE 35 AS EXPECTED...GRASSY/FINE FUEL TEMPERATURES WILL GET QUITE WARM THIS AFTERNOON. WINDS OF 15 TO 20 MPH COMBINED WITH AFTERNOON RELATIVE HUMIDITY VALUES BELOW 30 PERCENT SUPPORT AT LEAST A HIGH FIRE WEATHER DANGER ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR...AND A GRASS FIRE DANGER STATEMENT HAS BEEN ISSUED FOR THESE LOCATIONS AS A RESULT. CRITICAL TO EXTREME FIRE WEATHER DANGER IS POSSIBLE THIS AFTERNOON...BUT DEPENDENT UP ON THE STRENGTH OF WINDS AND POSITION OF THE DRYLINE. MOST MODEL GUIDANCE KEEPS WINDS BELOW RED FLAG WARNING CRITERIA THIS AFTERNOON OVER THE WESTERN CWA. THIS IS PARTLY BECAUSE MODELS HAVE A PART OF THE ELONGATED SURFACE LOW PRESSURE LOCATED VERY NEAR WICHITA FALLS...GENERALLY REDUCING THE PRESSURE GRADIENT FORCE THAT WOULD OTHERWISE ACCELERATE WINDS THE ADDITIONAL 5 TO 10 MPH NECESSARY TO REACH RED FLAG WARNING CRITERIA. HOWEVER IF THE SURFACE LOW IS A BIT FARTHER NORTH...LIKE THE RAP AND HRRR ADVERTISED AT THE TIME OF THIS DISCUSSION...EXTREME FIRE WEATHER DANGER MAY BE REALIZED THIS AFTERNOON AND A RED FLAG WARNING MAY NEED TO BE ISSUED. THE HRRR IN PARTICULAR SHOWED A STRONG DRYLINE PUNCH INTO THE WESTERN CWA...WITH THE DRYLINE PUSHING AS FAR EAST AS A JACKSBORO TO LAMPASAS LINE BY 21Z. THE HRRR INCREASES WESTERLY WINDS AT THE SURFACE TO 20 TO 25 KTS...OR STRONG ENOUGH FOR CRITICAL/EXTREME FIRE DANGER WITH RELATIVE HUMIDITY VALUES CRASHING INTO THE SINGLE DIGITS WEST OF THE DRYLINE. IF THESE HRRR CONDITIONS ARE REALIZED...A RED FLAG WARNING WOULD CERTAINLY BE WARRANTED BECAUSE ANY GRASS-FIRE IGNITED WOULD BE VERY DIFFICULT...IF NOT IMPOSSIBLE...TO CONTROL. THIS IS DEFINITELY A WORST CASE SCENARIO...AND IS NOT SUPPORTED BY ANY OTHER GUIDANCE AT THIS TIME. REGARDLESS...THIS BEARS WATCHING CLOSELY THROUGHOUT THE DAY AS THE HRRR WAS ALSO THE MOST RECENT GUIDANCE AVAILABLE AT THE TIME OF THIS DISCUSSION. THIS EVENING AND OVERNIGHT...THE SURFACE CYCLONE WILL CONTINUE EAST THIS EVENING...WITH A STRONG COLD FRONT DROPPING SOUTH ACROSS THE REGION IN ITS WAKE. WHILE MODELS DO NOT AGREE ON THE EXACT TIMING OF THE FRONT YET...ALL MODELS AGREE THAT THE FRONT WILL BE VERY FAST MOVING ONCE IT CROSSES THE RED RIVER THIS EVENING. WINDS WILL SHIFT QUICKLY AROUND TO THE NORTH BEHIND THE FRONT...AND PICK UP TO AT LEAST 20 MPH GUSTING ABOVE 30 MPH JUST BEHIND ITS LEADING EDGE. WINDS ARE EXPECTED TO INCREASE IN INTENSITY BY ABOUT 10 MPH OR SO AN HOUR OR TWO BEHIND THE INITIAL FRONTAL PASSAGE. SUSTAINED WINDS OF 30 MPH...GUSTING TO 45 MPH AT TIMES ARE EXPECTED AT PEAK INTENSITY OVERNIGHT. CONFIDENCE IN STRONG WINDS IS VERY HIGH AT THIS TIME AS ALL MODEL GUIDANCE SHOWS AT LEAST A 50 KT JET AT THE 850 MB LEVEL OVER THE CWA BEHIND THE FRONT TONIGHT. HIGHER RESOLUTION GUIDANCE INDICATES 55 TO 60 KT JET FROM 09 TO 12Z OVER THE CWA WELL BEHIND THE FRONT. WENT AHEAD WITH A WIND ADVISORY FOR THE ENTIRE CWA FROM 10 PM THIS EVENING THROUGH 1 PM WEDNESDAY AS THIS APPEARED TO BE THE BEST WINDOW FOR NORTH WINDS EXCEEDING 25 MPH OR GUSTING ABOVE 40 MPH. THE START OR END TIMES OF THIS ADVISORY WILL LIKELY BE ADJUSTED BY LATER SHIFTS AS THE EXACT TIMING OF THE FRONT IS BETTER RESOLVED. WEDNESDAY AND THURSDAY...WEDNESDAY WILL START OFF WITH THE WIND ADVISORY STILL IN EFFECT AS NORTH WINDS HOLD UP AROUND 25 MPH GUSTING TO 40 MPH JUST AFTER SUNRISE...AND THEN SLOWLY DIMINISH TO AROUND 20 MPH JUST AFTER NOON. WEDNESDAY WILL BE MUCH COOLER WITH HIGHS GENERALLY HOLDING IN THE MID 50S WITH STRONG COLD AIR ADVECTION IN PLACE. SKIES ARE EXPECTED TO STAY MOSTLY SUNNY ON WEDNESDAY...WHICH WILL AT LEAST TAKE SOME OF THE BITE OUT OF THE COOL...BREEZY AIR. HOWEVER...WINDS ARE EXPECTED TO BECOME LIGHT AND VARIABLE BY EARLY THURSDAY MORNING...UNDER MOSTLY CLEAR SKIES. THIS WILL BRING MANY LOCATIONS DOWN BELOW FREEZING WEDNESDAY NIGHT...WITH THE EXCEPTION OF URBANIZED AREAS WHICH WILL STAY WARMER DUE TO THE ABSORPTION OF SUNSHINE THROUGHOUT THE DAY ON WEDNESDAY. LIGHT WINDS WILL BECOME SOUTHERLY ON THURSDAY AS TEMPERATURES WARM INTO THE 60S. FRIDAY AND FRIDAY NIGHT...MODELS CONTINUE TO INDICATE A RELATIVELY COMPACT BUT STRONG SHORTWAVE TROUGH WILL MOVE OVER NORTH TEXAS FRIDAY AFTERNOON OR EVENING. BOTH THE GFS AND ECMWF WERE ADVERTISING SOME LIGHT QPF AMOUNTS ASSOCIATED WITH THIS TROUGH WHICH IS DIFFERENT FROM PREVIOUS DAYS. THINK THE QPF AMOUNTS...ALTHOUGH LIGHT...ARE STILL OPTIMISTIC BECAUSE TONIGHT`S FRONT IS EXPECTED TO PLOW SOUTH ALL THE WAY ACROSS THE WESTERN GULF OF MEXICO...EFFECTIVELY STUNTING OUR PRIMARY MECHANISM TO RECHARGE THE LOWER TROPOSPHERE WITH WATER VAPOR. THE SHORTWAVE TROUGH ITSELF IS EXPECTED TO ORIGINATE FROM THE TROUGH THAT SENDS THE STRONG FRONT SOUTH ACROSS THE REGION TONIGHT. IT IS EXPECTED TO BREAK OFF THE MAIN TROUGH AND REMAIN QUASI-STEADY OVER THE SOUTHWESTERN CONUS FOR A COUPLE OF DAYS BEFORE MOVING EAST WITH THE NEXT NORTHERN STREAM SHORTWAVE TROUGH THURSDAY NIGHT INTO FRIDAY. THE ONLY REASON THIS MATTERS AT ALL IS BECAUSE IT IS NOT LIKELY TO BE ASSOCIATED WITH A PLUME OF SOUTHERN PACIFIC MOISTURE...SO THE ORIGIN OF THE RAPID MOISTENING OF THE GFS AND ECMWF OUT AHEAD OF THE TROUGH IS A BIT OF A MYSTERY AT THIS TIME. GRANTED...LIFT ASSOCIATED WITH THE TROUGH IS EXPECTED TO BE STRONG...SO DYNAMIC LIFT...COOLING AND SATURATION FROM THE BOTTOM UP...IS POSSIBLE. WENT AHEAD WITH SOME 20 POPS FRIDAY AFTERNOON AND EVENING ACROSS THE FAR EASTERN CWA DUE TO UNCERTAINTY REGARDING THE SOURCE REGION OF MOISTURE FOR THE GFS AND ECMWF POP/QPF FORECAST. IF MOISTURE IS JUST BEING UNDERESTIMATED IN GENERAL...POPS AND QPF MAY HAVE TO BE BUMPED WEST IN LATER FORECASTS. NEXT WEEKEND...A STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE FROM THE NORTHWEST CONUS SOUTHEAST TOWARDS THE SOUTHERN PLAINS DURING THIS TIME. THE GFS CONTINUES TO BRING THIS TROUGH OVER NORTH TX...OR JUST OFF TO THE SOUTHWEST. IN GENERAL...RESULTING IN A WETTER FORECAST THAN IF THE TROUGH REMAINS TO THE NORTH OF THE CWA. YESTERDAY THE OPERATIONAL GFS HAD ALMOST NO ENSEMBLE SUPPORT FOR THIS SOLUTION...SO IT WAS LARGELY DISCOUNTED. HOWEVER TODAY...ABOUT HALF OF THE GFS ENSEMBLE MEMBERS AGREE WITH THIS SOLUTION...AND THE OPERATIONAL CANADIAN AND ECMWF HAVE SORT OF COME ON BOARD AS WELL. /SORT OF/ IS USED BECAUSE THERE ARE SOME FAIRLY LARGE TIMING AND STRENGTH DISCREPANCIES BETWEEN THESE MODELS. HOWEVER THE FORECAST TRACK OF THE UPPER TROUGH SEEMS TO BE THE MAIN DIFFERENCE DICTATING A WET VERSUS DRY FORECAST...SO IT IS GOOD TO SEE MODELS TRENDING TOWARDS A MORE SOUTHERLY TRACK AT THIS TIME. QPF AMOUNTS ARE NOT VERY HIGH IN ANY OF THESE SOLUTIONS...MOSTLY BECAUSE IN ALL SOLUTIONS THE UPPER TROUGH IS POSITIVELY TILTED UNTIL IT MOVES EAST OF THE SOUTH PLAINS. BUT...BEGGARS CANT BE CHOOSERS...AND WE REALLY NEED SOME RAIN...SO WILL CONTINUE TO WATCH THE EVOLUTION OF THIS WEEKENDS TROUGH CLOSELY IN THE COMING DAYS AND HOPE FOR THE BEST. CAVANAUGH && .PREV DISCUSSION... /ISSUED 328 AM CDT TUE MAR 11 2014/ IN THE SHORT TERM FORECAST THERE ARE TWO PRIMARY CONCERNS: 1. FIRE WEATHER DANGER WEST OF INTERSTATE 35 THIS AFTERNOON. 2. STRONG WINDS BEHIND A COLD FRONT LATE THIS EVENING THROUGH WEDNESDAY MORNING. WITH REGARDS TO FIRE WEATHER DANGER: WILL HOLD OFF ON ISSUING A RED FLAG WARNING AT THIS TIME. FIRE WEATHER DANGER WILL BE HIGH TO VERY HIGH WEST OF INTERSTATE 35 THIS AFTERNOON. CRITICAL OR EXTREME FIRE WEATHER DANGER IS POSSIBLE FOR LOCATIONS GENERALLY ALONG AND WEST OF A JACKSBORO TO LAMPASAS LINE IF WINDS ARE STRONGER THAN FORECAST THIS AFTERNOON. LEVEL OF CONFIDENCE IN HIGH FIRE DANGER IS HIGH. LEVEL OF CONFIDENCE IN EXTREME FIRE WEATHER DANGER IS LOW. WITH REGARDS TO THE STRONG WINDS BEHIND A COLD FRONT TONIGHT. NORTH WINDS OF 25 TO 30 MPH...GUSTING TO 40 TO 45 MPH AT TIMES ARE EXPECTED BEHIND THE COLD FRONT THROUGH SUNRISE. WINDS WILL BEGIN TO DIMINISH IN INTENSITY FROM SUNRISE TO NOON ON WEDNESDAY. THE LEVEL OF CONFIDENCE IN THESE STRONG WINDS IS HIGH...THEREFORE A WIND ADVISORY WILL BE ISSUED FOR THE ENTIRE CWA FROM 10 PM THIS EVENING TO NOON ON WEDNESDAY. A FULL DISCUSSION INCLUDING REASONING AND THE REMAINDER OF THE FORECAST WILL BE ISSUED LATER THIS MORNING. CAVANAUGH && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 85 42 57 36 62 / 5 0 0 0 0 WACO, TX 82 41 58 33 60 / 5 0 0 0 0 PARIS, TX 80 41 54 32 61 / 0 0 0 0 0 DENTON, TX 85 39 57 31 63 / 5 0 0 0 0 MCKINNEY, TX 83 39 56 31 63 / 5 0 0 0 0 DALLAS, TX 84 43 57 38 62 / 5 0 0 0 0 TERRELL, TX 81 42 57 33 60 / 5 0 0 0 0 CORSICANA, TX 81 44 57 35 60 / 10 0 0 0 0 TEMPLE, TX 82 42 59 33 60 / 5 0 0 0 0 MINERAL WELLS, TX 88 38 56 33 62 / 0 0 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 10 PM THIS EVENING TO 1 PM CDT WEDNESDAY FOR TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175. && $$ /
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1006 AM MDT TUE MAR 11 2014 .UPDATE... && .SHORT TERM...FRONT CURRENTLY PUSHING SOUTH ACROSS PLAINS... REACHED DENVER AT 15Z. NORTHERLY WINDS BEHIND FRONT...CURRENTLY GUSTING IN THE 35 TO 40 MPH RANGE. WINDS STILL EXPECTED TO INCREASE...WITH RUC AND HRRR INDICATING GUSTS OF 40 TO 50 MPH. BLOWING DUST ADVISORY SEEMS REASONABLE FOR LINCOLN COUNTY. AT THIS TIME...WINDS SHOULD REMAIN BELOW HIGH WIND CRITERIA. AS FOR SNOW ...MOUNTAIN AREAS SEEING ACCUMULATING SNOW AT THIS TIME. THERE MAY BE A BIT OF A DECREASE LATER THIS MORNING AS SLIGHTLY DRIER AIR MOVES OVER THE AREA. BUT A GOOD BATCH OF MOISTURE OVER WYOMING SHOULD SPREAD BACK INTO THE MOUNTAINS. WILL CONTINUE WITH THE CURRENT FORECAST TRENDS WITH ROUGHLY 3 TO 6 INCHES...NO ADVISORIES AT THIS TIME. ACROSS PLAINS...SNOWING LIGHTLY NORTH OF THE BORDER AT CHEYENNE AND KIMBLE. RADAR SHOWING SOME ECHOES ACROSS NORTHERN LARIMER COUNTY NEAR THE WYOMING BORDER. SHOULD SEE THE PRECIPITATION DEVELOP BEHIND THE FRONT WITHIN THE NEXT HOUR OR SO AS THE LOWER LEVELS OF THE ATMOSPHERE GRADUALLY MOISTEN. WITH TEMPERATURES FALLING BEHIND THE FRONT...THE PRECIPITATION WILL BE MAINLY SNOW WITH SOME RAIN MIXED IN FOR A SHORT PERIOD OF TIME. LATEST MODEL TRENDS INDICATING A 1 OR 2 INCH SNOWFALL FOR THE DENVER AREA WITH AS MUCH AS 4 INCHES FOR THE PALMER DIVIDE. INITIALLY THE SNOW SHOULD MELT BEFORE ANY ACCUMULATION OCCURS. LESS ACCUMULATION ELSEWHERE DUE TO DOWNSLOPE COMPONENT. BLOWING SNOW POSSIBLE WITH THE STRONG WIND AND ACCUMULATION. DON`T THINK AN ADVISORY FOR SNOW AND BLOWING SNOW WILL BE NEEDED FOR THE PALMER DIVIDE AT THIS TIME DUE TO THE INITIAL MELTING EXPECTED. WILL CONTINUE TO MONITOR TO SEE IF ONE WILL BE NEEDED. SNOW TO END FROM NORTH TO SOUTH DURING THE EVENING WITH SUBSIDENCE AND DRIER AIRMASS. OVERALL...CURRENT FORECAST LOOK REASONABLE WITH SOME ADJUSTMENTS DUE TO TIMING OF FRONT. .AVIATION...FRONT MOVING ACROSS DIA WITH NORTHERLY WINDS GUSTING TO 28 KTS. FRONT SHOULD BE MOVING INTO KBJC AND KAPA WITHIN THE NEXT ONE HALF HOUR WITH WINDS SHIFTING TO THE NORTH AND INCREASING TO 25 TO 30 KTS. SOME GUSTS TO 40 KTS POSSIBLE DURING THE AFTERNOON. SNOW TO DEVELOP BY 18Z WITH MVFR CONDITIONS. IFR CONDITIONS POSSIBLE WITH THE HEAVIER SNOW SHOWERS. SNOW EXPECTED TO END BETWEEN 00Z AND 01Z WITH DECREASING WINDS. AT THIS TIME THE FRONT RANGE AIRPORTS SHOULD SEE BETWEEN ONE AND TWO INCHES OF SNOW ACCUMULATION. THERE IS A SLIGHT CHANCE THAT KAPA COULD RECEIVE AROUND 3 INCHES IF CONVECTION IS A BIT MORE PRONOUNCED. STILL EXPECTING VFR CONDITIONS WITH LIGHTER WINDS OVERNIGHT. AT THIS TIME...FOG OR LOW CLOUDS ARE NOT EXPECTED TO DEVELOP. && .PREV DISCUSSION... /ISSUED 420 AM MDT TUE MAR 11 2014/ SHORT TERM...STILL A COMPLEX WEATHER SCENARIO FOR THE FORECAST AREA TODAY. BUT COLD...STRONG WINDS...AND SNOW STILL ON THE WAY. PREFRONTAL WIND SHIFT IS ALREADY OCCURRING ACROSS THE NORTHEAST PLAINS PER LATEST OBS. MAIN COLD FRONT HAD JUST PUSHED THROUGH CASPER WYOMING SO THATS ON TRACK TO REACH THE BORDER SHORTLY BEFORE DAYBREAK AND DENVER METRO AROUND 9 AM. BIG SURFACE PRESSURE RISES ARE OCCURRING BEHIND THE FRONT AND INCREASING...SO A SLIGHTLY EARLIER ARRIVAL IS POSSIBLE. WINDS WILL INCREASE WITH AND JUST BEHIND THE FRONT WITH WIDESPREAD GUSTS OF 40 TO 55 MPH...STRONGEST ON THE EASTERN PLAINS. LOCATIONS AROUND LINCOLN COUNTY HAVE BEEN DRIER THERE RECENTLY THAN ANYWHERE ELSE SO BLOWING DUST WILL BE A CONCERN BEFORE ANY WIDESPREAD PRECIPITATION THIS AFTERNOON...SO HAVE ISSUED A BLOWING DUST ADVISORY THERE. WITH REGARD TO SNOWFALL...MOUNTAINS WERE ALREADY SEEING ONE BATCH OF SNOW...BUT THIS WILL LIKELY DECREASE A BIT EARLY THIS MORNING AS SOME TEMPORARILY DRIER AIR MOVES ACROSS. MORE WIDESPREAD SNOW IS EXPECTED TO DEVELOP BEHIND THE FRONT PER UPSTREAM OBS. LOW/MID LEVELS ARE INITIALLY DRY...SO LOOK FOR PRECIPITATION TO DEVELOP WITHIN ABOUT 2-4 HOURS OF FRONTAL ARRIVAL. TEMPERATURES WILL BE COLD ENOUGH FOR ALMOST ALL SNOW AND WILL GET COLDER THROUGH THE DAY. THERE MAY BE A BIT OF LIGHT RAIN ON THE LEADING EDGE OF PRECIP. SATELLITE SHOWS CONVECTION ASSOCIATED WITH UPPER LEVEL COLD POOL NOW MOVING ACROSS NORTHERN UTAH AND WYOMING...WHICH WILL REACH THE FRONT RANGE BY 18Z. THE COMBINATION OF UPSLOPE AND COLD POOL ALOFT MEANS A MOISTENING AIRMASS WITH VERY STEEP LAPSE RATES...SO CONVECTIVE POTENTIAL IS THERE. OVERALL...THINK THE CONVECTIVE POTENTIAL WILL HELP OFFSET THE SPARSE MODEL QPF. ADDED A LITTLE MORE SNOW TO THE NORTHEAST CORNER LATER THIS MORNING INTO THE AFTERNOON BASED ON LATEST MESOSCALE MODEL OUTPUT AND BETTER MOISTURE THERE...WHILE CUT BACK AMOUNTS ON THE DOWNSLOPE SIDE OF THE CHEYENNE RIDGE GIVEN STRONG NORTHERLY FLOW IN PLACE. DENVER AREA STILL EXPECTED TO SEE A 1-2 INCH SNOWFALL BUT STILL SOME UNCERTAINTY FOR HIGHER OR LOWER AMOUNTS BASED ON CONVECTIVE NATURE. THE MOST FAVORED LOCATION FOR SNOW IN THIS FLOW PATTERN WOULD BE FOOTHILLS OF JEFFERSON/DOUGLAS COUNTIES AS WELL AS THE PALMER DIVIDE...SO WILL GO WITH HEAVIER AMOUNTS OF 2-5 INCHES POSSIBLE THERE. GIVEN THE STRONG WINDS...ALSO MENTIONED AREAS OF BLOWING SNOW WHERE MORE THAN AN INCH OR TWO OF ACCUMULATION IS EXPECTED. MOUNTAIN LOCATIONS SHOULD SEE STORM TOTALS MOSTLY IN THE 3-6 INCH RANGE. SNOW WILL DECREASE LATE THIS AFTERNOON INTO EARLY EVENING FROM NORTH TO SOUTH AS AIRMASS DRIES AND SUBSIDENCE BUILDS IN. SKIES WILL THEN CLEAR OUT FOR OVERNIGHT. WINDS WILL DECREASE BY OR SHORTLY AFTER SUNSET. LONG TERM...MEDIUM AND LONG RANGE PORTIONS OF THE FORECAST INCLUDE GENERALLY DRY AND MILD WEATHER AS A WESTERN U.S. RIDGE PRODUCES WARM NORTHWESTERLY FLOW OVER COLORADO. ON WEDNESDAY AND THURSDAY...THE UPPER RIDGE WILL BE HELD OVER COLORADO WHILE A WEAK...CUTOFF LOW MEANDERS FROM SOUTHERN NEVADA TO CENTRAL NEW MEXICO. OUR REGION WILL BE LEFT UNDER THE DEFORMATION REGION WITH WEAK FLOW ALOFT. THE UPPER FEATURE SHOULD EVENTUALLY KICK OUT ONTO THE SOUTHERN PLAINS BY ABOUT FRIDAY WITH LITTLE ADDITIONAL IMPACT ON NORTHERN COLORADO WEATHER. FROM FRIDAY THROUGH SATURDAY...NORTHWEST FLOW ALOFT WILL INCREASE OVER THE STATE AS THE UPPER LOW DEPARTS. LATER ON SATURDAY...A WEAK SHORT WAVE EMBEDDED IN THE NORTHWEST FLOW PATTERN IS FORECAST TO SLIDE OVER THE STATE. THIS FEATURE WILL BRING A CHANCE OF SNOW TO THE MOUNTAINS AND MAY BRING SOME PRECIPITATION TO THE PLAINS THROUGH SATURDAY NIGHT. EACH OF THE SYNOPTIC MODELS HAVE VARIOUS IDEAS ON THE TIMING OF THE SOUTHWESTERN CUTOFF LOW EJECTING AND SUBSEQUENT PASSAGE OF UPPER TROUGH ACROSS COLORADO. FOR NOW HAVE FAVORED THE GFS SOLUTION...AS THE CANADIAN AND ECMWF LOOK A LITTLE TOO FAST. BEYOND THAT...MORE WESTERN U.S. RIDGING IS FORECAST WITH SUBSIDENT NORTHWESTERLY FLOW EXPECTED OVER COLORADO. DRY WEATHER AND WARMER TEMPERATURES WILL BE THE RESULT. TEMPERATURE FORECASTS THROUGH THE PERIOD WERE A COMPROMISE BETWEEN THE TOO WARM GFS MOS GUIDANCE AND CONSERVATIVE GENERALLY CONSERVATIVE NUMBERS FROM ECMWF MOS GUIDANCE. FORECASTING THE PRECIPITATION TYPE ON THE PLAINS IS GOING TO BE CHALLENGING AND DEPEND ON THE TIME OF DAY OR NIGHT WHEN THE WEATHER SYSTEMS PASS OVER THE AREA. DAYTIME PRECIPITATION WILL BE IN LIQUID FORM WHILE EVENING AND OVERNIGHT TIME PERIODS WILL FAVOR SNOW OR A RAIN/SNOW MIX. AVIATION...STRONG COLD FRONT EXPECTED TO REACH THE FRONT RANGE AIRPORTS AROUND 15Z...PERHAPS A BIT EARLIER AT KDEN. SOME STRATUS AND POTENTIAL FOR MVFR CEILINGS TO DEVELOP BEHIND THE FRONT...THEN SNOW WILL BECOME LIKELY BY 18Z-21Z WITH IFR CONDITIONS IN HEAVIER SNOW SHOWERS. WINDS WILL INCREASE SIGNIFICANTLY BEHIND THE FRONT WITH GUSTS TO 35-40 KTS LIKELY FROM ALMOST DUE NORTH. SNOW WILL END BY 00Z-01Z WITH WINDS DECREASING SIGNIFICANTLY BY THEN AS WELL. FRONT RANGE AIRPORTS MOST LIKELY TO SEE 1-2 INCH SNOW TOTALS...WITH POTENTIAL FOR A LITTLE MORE THAN THAT AT KAPA IF CONVECTION BECOMES MORE WIDESPREAD. VFR CONDITIONS AND LIGHTER WINDS OVERNIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES... BLOWING DUST ADVISORY UNTIL 7 PM MDT THIS EVENING FOR COZ046-047. && $$ SHORT TERM...D-L LONG TERM....DANKERS AVIATION...D-L
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
247 PM CDT TUE MAR 11 2014 .DISCUSSION... 1234 PM CDT WINTER STORM UPDATE... CONTINUING TO ASSESS 12Z MODEL DATA FOR IMPENDING WINTER STORM. SURFACE OBSERVATION ANALYSIS SHOWS 996 MB LOW IN CENTRAL KS ROUGHLY BETWEEN SLN AND HUT...NORTH OF LATEST RUN OF RAP MODEL. TRENDS SO FAR SUPPORT THE AXIS OF HEAVIEST SNOW IN GOING FORECAST AND HAVENT MADE ANY CHANGES TO THIS YET...WITH ONLY TWEAKS TO LATE AFTERNOON POPS AS BAROCLINIC ZONE STARTS TO SHIFT SOUTH AND RAIN COMMENCES IN FAR NORTHERN CWA. RAIN SHOULD QUICKLY FLIP OVER TO SNOW THIS EVENING IN NORTHERN ILLINOIS AS COLDER AIR FILTERS IN FROM THE NORTH. OF BIGGEST CONCERN WITH THE SNOW LATE TONIGHT IS THE BAND OF VERY STRONG 850-700 MB FGEN OVERLAID BY NEGATIVE EPV...AS WELL AS THE PRESENCE OF 50-100 J/KG OF MUCAPE. THIS HIGHLIGHTS POTENTIAL FOR CONVECTIVE SNOW BANDS AND RATES OF 2 INCHES PLUS PER HOUR WHEREVER THIS SETS UP. KEEPING TOTALS IN CHECK WILL BE PROGRESSIVE NATURE OF SYSTEM WITH MIDLEVEL TROUGH REMAINING OPEN...SO WOULD ONLY EXPECT A FEW HOUR PERIOD WITH THE REALLY HEAVY RATES IN ANY GIVEN AREA. NONETHELESS...COULD SEE SOME ISOLATED TOTALS TO OR EVEN A BIT ABOVE 8 INCHES IN WARNING AREA...WITH THIS MOST LIKELY TO OCCUR ROUGHLY ALONG AND A BIT EAST OF I-55 CORRIDOR. LIKELY BECAUSE OF BANDING POTENTIAL...HIGHER RES GUIDANCE SHOWING A VERY SHARP CUTOFF TO PRECIP IN NORTHERN CWA...AND THINK THIS IS OVERDONE...BUT THERE WILL BE A GRADIENT IN SNOW AMOUNTS ROUGHLY IN LINE WITH GOING FORECAST. FARTHER SOUTH IN WATCH AREA...UNCERTAINTY REMAINS OVER HOW FAST CHANGEOVER WILL OCCUR AND HOW MUCH PRECIP WILL FALL AFTER CHANGEOVER...SO WILL MAKE A DECISION ON HEADLINE FOR SOUTHEAST CWA WITH AFTERNOON ISSUANCE. FINALLY...WINDS REMAIN A SIGNIFICANT CONCERN AS WELL LATE TONIGHT INTO WEDNESDAY MORNING...WITH SOUNDINGS SUPPORTING NORTHERLY WIND GUSTS TO 40+ MPH. THIS WILL EXACERBATE IMPACTS TO WEDS AM COMMUTE EVEN AS SNOW WINDS DOWN. RC/JEE //PREV DISCUSSION... 343 AM CDT THE TASTE OF SPRING YESTERDAY IS TRULY IN THE REAR VIEW MIRROR AS THE FORECAST FOCUS WAS ON WINTER STORM SET TO IMPACT THE AREA TONIGHT INTO EARLY WEDNESDAY. HAVE ISSUED A WINTER STORM WARNING CENTERED ON THE I-80 CORRIDOR...AND THAT INCLUDES CHICAGO...FOR THE COMBINATION OF HEAVY SNOWFALL RATES OF UP TO 2 INCHES PER HOUR...SNOW TOTALS AROUND SIX INCHES...AND WIND WHIPPED SNOW GREATLY REDUCING VISIBILITY. CONTINUE THE WATCH SOUTH OF THERE AND AN ADVISORY TO THE NORTH. THE PRIMARY UPPER LOW IS WELL-DEFINED THIS MORNING ACROSS WYOMING AND ADVANCING SOUTHEAST WITH OVER 200M HEIGHT FALLS AT 300MB SAMPLED LAST EVE. SECOND KEY SHORT WAVE IS DROPPING SOUTHWARD FROM MANITOBA. THE PHASING OF THESE SYSTEMS IS ANTICIPATED TO OCCUR ACROSS THE WESTERN GREAT LAKES OVERNIGHT INTO WEDNESDAY MORNING. AS OFTEN SEEN WITH PHASING SYSTEMS...FORCING FOR LIFT AND HEAVY PRECIP IS EXPECTED TO RAPIDLY INCREASE TONIGHT. NUMERICAL GUIDANCE HAS HAD SOME PRONOUNCED DIFFERENCES AND THAT CONTINUED INTO THE 11.00Z AND 11.06Z CYCLES...BUT IT IS IMPORTANT TO NOTE THAT ALL GUIDANCE DEPICT ALL THE INGREDIENTS FOR HEAVY SNOWFALL AND THAT ARE CONSISTENT WITH A PHASING SYSTEM. HAVE PREFERRED THE GLOBAL GUIDANCE SOLUTION OF MASS FIELDS AND TAKEN INTO ACCOUNT THE MRF AND LOCAL HIGH RES MODELS IDEAS OF MESOSCALE VERY HEAVY SNOWFALL RATES AND TIMING. BELIEVE THE MRF IS A LITTLE TOO ROBUST AND WIDESPREAD WITH ITS HEAVIEST QPF...BUT AGAIN THE IDEA OF HEAVY SNOWFALL WITH AMOUNTS EXCEEDING SIX INCHES IN AN AREA IS SUPPORTED. TODAY... THIS STILL LOOKS MAINLY DRY ACROSS THE FORECAST AREA WITH A VERY SHARP MID-LEVEL STATIONARY FRONT SAMPLED ON LAST EVES RAOBS BECOMING MORE ACTIVE AHEAD OF THE APPROACHING TROUGHS. EARLY MORNING RADAR MOSAIC INDICATES PRECIP FROM SD THROUGH WESTERN WI. THIS SHOULD ONLY INCH SOUTHWARD GRADUALLY TODAY. FRONTOGENESIS RESPONSE FROM EVEN THE MOST SOUTH HIGH RESOLUTION GUIDANCE WOULD KEEP RAIN NORTH OF THE AREA THROUGH MID-AFTERNOON. STILL SHOULD SEE PLENTY OF CLOUD COVER AND WITH NORTHEAST WINDS INCREASING AHEAD OF CYCLOGENESIS IN THE PLAINS...EXPECT THAT SURFACE TEMPERATURES WILL START TO LEVEL OUT AROUND THE NOON HOUR AND THEN BEGIN TO GRADUALLY FALL. ONSHORE FLOW INTO CHICAGO OFF THE ICE-COVERED LAKE MAY LEAD TO A MORE RAPID FALL DOWNTOWN. TONIGHT AND WEDNESDAY MORNING... IN RESPONSE TO THE AFOREMENTIONED PHASING...MAXIMUM HEIGHT FALLS ARE CENTERED DIRECTLY ON THE AREA TONIGHT WITH LIFT RAPIDLY INCREASING. THIS WILL EVOLVE THE LOW-LEVEL FEATURES EASTWARD WITH COPIOUS MOISTURE TRANSPORTED NORTH OF A 40-45 KT LOW-LEVEL JET. PRECIP FROM THE NORTH IS EXPECTED TO QUICKLY MOVE SOUTH...WHILE NEW PRECIP SHOULD DEVELOP JUST WEST OR OVER THE AREA THIS EVE. THE DEGREE OF FORCING AND COOL ADVECTION IN THE NORTHEAST QUADRANT OF THE SYSTEM WILL HELP TO COOL THE COLUMN FROM NORTH TO SOUTH FOR A TRANSITION OF RAIN TO SNOW...AND THIS WILL BE ESPECIALLY TRUE DURING THE MID EVE INTO EARLY OVERNIGHT AS THE MOST ROBUST FORCING MOVES IN. WOULD EXPECT SOME AREAS OF NORTHERN ILLINOIS MAY JUST BEGIN AS SNOW OR EXPERIENCE A VERY SHORT MIX. AS FOR AREAS ALONG AND SOUTH OF I-80...A COUPLE/SEVERAL HOUR WINDOW OF RAIN WILL BE LIKELY FIRST BEFORE TRANSITIONING TO A WET SNOW LATE THIS EVE INTO EARLY OVERNIGHT. THAT TIME PERIOD AFTER TRANSITION AND INTO OVERNIGHT IS MOST FAVORED FOR HEAVY SNOWFALL...WITH UPRIGHT INSTABILITY FORECAST BY GLOBAL MODELS TO REACH INTO THE CENTRAL FORECAST AREA...WHICH LINES UP WITH THE DEEPEST CONVERGENCE AND FOCUS NEAR I-80. THE 11.03Z SREF PROBABILITIES OF OVER ONE INCH PER HOUR SNOWFALL RATES ARE TO 70 PERCENT WHICH IS IMPRESSIVE AND MAKE SENSE...AND WOULD NOT BE SURPRISED TO SEE TEMPORARY TWO INCH PER HOUR OR HIGHER RATES LATE THIS EVE INTO OVERNIGHT. THE WINDS LOOK TO REALLY RAMP UP OVERNIGHT AROUND THE DEEPENING LOW...WITH 45 KT OF NORTHEAST FLOW ON THE NAM AND GFS AT 1000-2000 FT. EVEN WITH THE WET SNOW...EXPECT THAT THE BLOWING OF THE FALLING SNOW WILL CAUSE EVEN FURTHER REDUCED VISIBILITY...AND EVEN TEMPORARY WHITE OUT CONDITIONS IN THE HEAVIEST OF SNOWFALL RATES. BY WEDNESDAY MORNING SNOW SHOULD BE ENDING FROM WEST TO EAST...ALTHOUGH SOME PRETTY SOLID RATES COULD STILL BE OCCURRING IN EASTERN AREAS...INCLUDING POSSIBLY CHICAGO INTO THE EARLY PARTS OF THE MORNING COMMUTE. UNCERTAINTY ON END TIME OF SNOWFALL IS FAIRLY HIGH...BUT THE WINDS SHOULD CONTINUE AND SO EXPECT IMPACTS...AND THAT MAY BE ESPECIALLY TRUE NEAR THE LAKE SHORE WHERE THE WIND COULD GUST TO 40-45 MPH. THAT IS WHY RUN HEADLINES THROUGH NOON. WITH THE HIGH MOISTURE...AS DEPICTED BY MIXING RATIOS OF 4-6 G/KG AND PWATS OF AROUND 0.75 IN...THERE SHOULD NOT BE TOO MUCH OF A PROBLEM WITH SNOWFALL AMOUNTS IN THE MAXIMUM AREA TOPPING SIX INCHES...EVEN WITH THE QUICK MOVEMENT OF THE SYSTEM AND LOW SNOW-TO-LIQUID RATIOS. THE HIGHEST AMOUNTS COULD EXCEED 8 INCHES IN ISOLATED AREAS...BUT AGAIN LIMITED DURATION SHOULD PREVENT THAT FROM BEING TOO WIDESPREAD. HEADLINES... GIVEN RATES AND BLOWING OF THE FALLING SNOW...WITH BASICALLY A DOWNPOUR OF SNOW WITH CONCURRENT GUSTS OF 30+ MPH...HAVE OPTED TO GO WITH A WARNING FOR THE AREA WITH THE LONGEST DURATION OF SNOW....EVEN THOUGH NOT EVERYWHERE WILL SEE SIX PLUS INCHES OF SNOW. UNCERTAINTY OF SNOW DURATION IN THE FAR SOUTH LED TO CONTINUING THE WATCH. FURTHER NORTH HAVE AN ADVISORY...AND DID NOT INCLUDE ROCKFORD BECAUSE IT LOOKS LIKE SNOWFALL SHOULD HAVE ENDED BY MUCH OF IF NOT THE ENTIRE WED MORNING COMMUTE. IT IS CERTAINLY POSSIBLE ADJUSTMENTS TO THE NORTHERN END OF HEADLINES ARE MADE TODAY. WEDNESDAY NIGHT AND THURSDAY... NOT MUCH CHANGE MADE TO THIS PERIOD. WEDNESDAY NIGHT LOOKS TO BE PRETTY CHILLY WITH THE FRESH SNOW COVER AND DIMINISHING WINDS...AND IF THE SKY CAN REMAIN CLEAR THE LOWS MAY BE WITHIN FIVE DEGREES OF RECORD LOWS FOR MARCH 13TH. MTF EXTENDED FORECAST...FRIDAY THROUGH TUESDAY... 210 PM CDT... FOR THE EXTENDED FORECAST PERIOD...THE MAIN ISSUE WILL BE TEMPERATURES ACROSS THE REGION. THE LONGER RANGE GUIDANCE IS SUGGESTING THAT THE MAIN FEATURES OF INTEREST WILL BE A PAIR OF CLIPPER DROPPING OUT OF NORTHERN ALBERTA AND TRACKING ACROSS THE UPPER GREAT LAKES REGION. PERIODS OF WARMING WILL PRECEDE THE CLIPPERS WITH HIGHS ON FRIDAY IN THE MIDDLE 40S TO LOWER 50S. FOLLOWING A WEAK COLD FRONTAL PASSAGE ASSOCIATED WITH THE FIRST CLIPPER WILL BRING TEMPS BACK TO BELOW NORMAL FOR SUNDAY WITH HIGHS ONLY IN THE UPPER 20S TO MIDDLE 30S. TOWARD THE END OF THE FORECAST PERIOD...THERE IS THE POTENTIAL FOR TEMPERATURES TO REACH INTO THE LOWER 50S AHEAD OF THE SECOND CLIPPER. THERE MAY AND UP BEING SOME TIMING CHANGES WITH THESE SYSTEMS AS WE GET CLOSER TO THE EVENTS...BUT THE GENERAL SIGNAL IS FOR ABOVE NORMAL TEMPERATURES FOR MUCH OF THE EXTENDED FORECAST PERIOD...WITH THE EXCEPTION OF THE PERIOD FOLLOWING THE PASSAGE OF THE FIRST CLIPPER WHICH WILL BRING BACK A DIP INTO BELOW NORMAL TEMPERATURE RANGES. AS FOR THE PRECIPITATION OUTLOOK...THIS WILL BE HIGHLY DEPENDENT ON THE TRACKS OF THE CLIPPERS...BUT AT THIS POINT...IT APPEARS THAT THEY WILL TRACK TO FAR NORTH TO HAVE MUCH OF AN IMPACT ON NORTHERN ILLINOIS AND NORTHWEST INDIANA. SO...WILL CARRY DRY FORECAST FOR MUCH OF THE EXTENDED PERIOD...WITH ONLY SOME SLIGHT CHANCE POPS ON SUNDAY WITH THE FROPA ASSOCIATED WITH THE PASSAGE OF THE FIRST CLIPPER. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * NORTHEAST WINDS INCREASING TODAY AND TONIGHT WITH GUSTS OF 30-35 KT LIKELY TONIGHT INTO WEDNESDAY MORNING. * RAIN/SNOW MIX BY MID EVENING...RAPIDLY CHANGING OVER TO ALL SNOW SOON THERE AFTER. * RAPIDLY DETERIORATING CONDITIONS IN SNOW WITH VIS/CEILINGS FALLING TO LIFR/VLIFR. * PERIOD OF HEAVY SNOW WITH SIGNIFICANTLY REDUCED VIS LIKELY AFTER MIDNIGHT. * BLOWING SNOW OVERNIGHT INTO WEDNESDAY MORNING. RODRIGUEZ //DISCUSSION...UPDATED 18Z... VFR CONDITIONS AND AN INCREASING NORTHEAST WIND IN PLACE OVER THE TERMINALS EARLY THIS AFTERNOON AS APPROACHING LOW TO THE SOUTHWEST CONTINUES TO WORK ITS WAY TOWARDS THE AREA. WINDS WILL STEADILY INCREASE THROUGH THE AFTERNOON AND EVENING WITH HIGHEST GUSTS EXPECTED OVERNIGHT INTO WEDNESDAY MORNING. VFR CEILINGS WILL LOWER THIS AFTERNOON BUT THEN QUICKLY DETERIORATE AS BETTER FORCING ARRIVES THIS EVENING WITH MVFR CONDITIONS BECOMING IFR SOON THERE AFTER...WITH THESE CEILINGS THEN LIKELY FOR MOST OF THE NIGHT. A RAIN/SNOW MIX WILL SPREAD OVER THE TERMINALS THIS EVENING BUT EXPECT A RAPID CHANGE OVER TO ALL SNOW BASICALLY WITHIN AN HOUR OF ONSET. NO REAL CHANGES TO EXPECTED SNOW TONIGHT AND TIMING WITH THE 6-10Z TIME FRAME STILL THE BEST TIME FOR MORE MODERATE TO HEAVY SNOW. HAVE LEFT THE LOWEST VIS AT 1/2 MILE FOR ALL THE TERMINAL SITES...BUT WITH THEM LIKELY OBSERVING PERIODS OF 1/4 MILE OR EVEN LESS AT TIMES. EXPECT THIS HEAVIER SNOW TO BE MORE TIED TO CONVECTIVE ASPECTS...WITH UNCERTAINTY TO EXACT TIMING AND DURATION OF THIS HEAVIER SNOW ASSOCIATED WITH THIS FEATURE. MDW/GYY WOULD LIKELY HAVE THE BEST CHANCES FOR 1/4 MILE OR LESS VISIBILITY AS WELL AS FOR A LONGER DURATION AS THIS WILL BE A MORE FAVORED LOCATION FOR THE BEST SNOWFALL DEVELOPMENT. BUT ONCE AGAIN...WITH SOME UNCERTAINTY REMAINING...HAVE OPTED TO LEAVE OUT OF THE TAF AT THIS TIME BUT COULD SEE THIS LOWER VIS IN HEAVY SNOW ADDED LATER THIS EVENING. BEST SNOW DEVELOPMENT SHOULD EXIT THE TERMINALS BY EARLY WEDNESDAY MORNING...TAPERING OFF THROUGH THE MORNING WITH A SLOW IMPROVING TREND WITH CEILINGS. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION...AND RESULTANT BLOWING SNOW. * MEDIUM HIGH CONFIDENCE WITH RAIN/SNOW MIX TIMING AND CHANGE OVER TO SNOW. * MEDIUM CONFIDENCE WITH VIS/CEILING TRENDS. * MEDIUM HIGH CONFIDENCE WITH HEAVY SNOW...LOW MEDIUM CONFIDENCE WITH TIMING/DURATION. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... * WEDNESDAY NIGHT...DRY/VFR. * THURSDAY...DRY/VFR. GUSTY SOUTHWEST WINDS. * FRIDAY...DRY/VFR. GUSTY WESTERLY WINDS. * SATURDAY...DRY/VFR. * SUNDAY...SLIGHT CHANCE OF SNOW. * MONDAY...DRY/VFR. && .MARINE... 210 PM CDT LOW PRESSURE OVER THE CENTRAL PLAINS WILL CONTINUE TO DEEPEN AS IT TRACKS EAST ACROSS SOUTHERN ILLINOIS TONIGHT AND INTO THE OHIO VALLEY WEDNESDAY. AS THE LOW TRACKS SOUTH AND THEN SOUTHEAST OF THE LAKE...HIGH PRESSURE WILL ALSO BUILD ACROSS THE UPPER GREAT LAKES REGION...SETTING UP STRONG NORTH WINDS. THE COMBINATION OF A STRONG GRADIENT AND STRONG COLD ADVECTION WILL LEAD TO WINDS QUICKLY INCREASING TO GALES BY LATE THIS EVENING. THE LATEST GUIDANCE HAS BEEN RELATIVELY CONSISTENT IN INDICATING THE POTENTIAL FOR HIGH END GALES BY LATE WEDNESDAY MORNING AND EARLY AFTERNOON...WITH THE STRONGEST GALES OVER THE SOUTHERN PORTIONS OF THE LAKE...INCLUDING THE NEARSHORE WATERS. BY WEDNESDAY EVENING...THE HIGH PRESSURE WILL BEGIN TO SPREAD ACROSS LAKE MICHIGAN ALLOWING WINDS TO SUBSIDE BELOW GALE FORCE. BY THURSDAY NIGHT...THE HIGH WILL PUSH TO THE SOUTHEAST OF THE LAKE AS A CLIPPER DROPS OUT OF NORTHERN ALBERTA AND SWINGS JUST NORTH OF THE UPPER GREAT LAKES ON FRIDAY. WITH THE SFC HIGH SAGGING OFF THE SERN COAST...A PERIOD OF SWLY WINDS WILL DEVELOP AHEAD OF AN APPROACHING COLD FRONT TRAILING FROM THE CLIPPER. ANTICIPATE A PERIOD OF BRISK SLY TO SWLY WINDS FOR THURSDAY NIGHT THROUGH FRIDAY...BUT MORE GALES ARE NOT EXPECTED AT THIS TIME. AS THE CLIPPER TURNS NEWD INTO QUEBEC...IT WILL DRAG A WEAK COLD FRONT DOWN THE LAKE WITH ANOTHER ARCTIC HIGH BUILDING IN BEHIND THE FRONT. 25-30KT NORTH WINDS WILL SET UP FOLLOWING THE FROPA FOR SATURDAY NIGHT AND SUNDAY...BUT AS THE HIGH SPREADS ACROSS THE GREAT LAKES SUNDAY NIGHT...WINDS SHOULD BECOME MORE LIGHT AND VARIABLE. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER STORM WARNING...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032...10 PM TUESDAY TO 1 PM WEDNESDAY. WINTER STORM WARNING...ILZ033-ILZ039...1 AM WEDNESDAY TO 1 PM WEDNESDAY. WINTER WEATHER ADVISORY...ILZ006-ILZ008-ILZ010-ILZ011- ILZ012...10 PM TUESDAY TO 10 AM WEDNESDAY. IN...WINTER STORM WARNING...INZ001-INZ002...10 PM TUESDAY TO 1 PM WEDNESDAY. WINTER STORM WARNING...INZ010-INZ011-INZ019...1 AM WEDNESDAY TO 1 PM WEDNESDAY. LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741- LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872- LMZ874-LMZ876-LMZ878...MIDNIGHT WEDNESDAY TO 10 PM WEDNESDAY. GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567- LMZ868...MIDNIGHT WEDNESDAY TO 7 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
211 PM CDT TUE MAR 11 2014 .DISCUSSION... 1234 PM CDT WINTER STORM UPDATE... CONTINUING TO ASSESS 12Z MODEL DATA FOR IMPENDING WINTER STORM. SURFACE OBSERVATION ANALYSIS SHOWS 996 MB LOW IN CENTRAL KS ROUGHLY BETWEEN SLN AND HUT...NORTH OF LATEST RUN OF RAP MODEL. TRENDS SO FAR SUPPORT THE AXIS OF HEAVIEST SNOW IN GOING FORECAST AND HAVENT MADE ANY CHANGES TO THIS YET...WITH ONLY TWEAKS TO LATE AFTERNOON POPS AS BAROCLINIC ZONE STARTS TO SHIFT SOUTH AND RAIN COMMENCES IN FAR NORTHERN CWA. RAIN SHOULD QUICKLY FLIP OVER TO SNOW THIS EVENING IN NORTHERN ILLINOIS AS COLDER AIR FILTERS IN FROM THE NORTH. OF BIGGEST CONCERN WITH THE SNOW LATE TONIGHT IS THE BAND OF VERY STRONG 850-700 MB FGEN OVERLAID BY NEGATIVE EPV...AS WELL AS THE PRESENCE OF 50-100 J/KG OF MUCAPE. THIS HIGHLIGHTS POTENTIAL FOR CONVECTIVE SNOW BANDS AND RATES OF 2 INCHES PLUS PER HOUR WHEREVER THIS SETS UP. KEEPING TOTALS IN CHECK WILL BE PROGRESSIVE NATURE OF SYSTEM WITH MIDLEVEL TROUGH REMAINING OPEN...SO WOULD ONLY EXPECT A FEW HOUR PERIOD WITH THE REALLY HEAVY RATES IN ANY GIVEN AREA. NONETHELESS...COULD SEE SOME ISOLATED TOTALS TO OR EVEN A BIT ABOVE 8 INCHES IN WARNING AREA...WITH THIS MOST LIKELY TO OCCUR ROUGHLY ALONG AND A BIT EAST OF I-55 CORRIDOR. LIKELY BECAUSE OF BANDING POTENTIAL...HIGHER RES GUIDANCE SHOWING A VERY SHARP CUTOFF TO PRECIP IN NORTHERN CWA...AND THINK THIS IS OVERDONE...BUT THERE WILL BE A GRADIENT IN SNOW AMOUNTS ROUGHLY IN LINE WITH GOING FORECAST. FARTHER SOUTH IN WATCH AREA...UNCERTAINTY REMAINS OVER HOW FAST CHANGEOVER WILL OCCUR AND HOW MUCH PRECIP WILL FALL AFTER CHANGEOVER...SO WILL MAKE A DECISION ON HEADLINE FOR SOUTHEAST CWA WITH AFTERNOON ISSUANCE. FINALLY...WINDS REMAIN A SIGNIFICANT CONCERN AS WELL LATE TONIGHT INTO WEDNESDAY MORNING...WITH SOUNDINGS SUPPORTING NORTHERLY WIND GUSTS TO 40+ MPH. THIS WILL EXACERBATE IMPACTS TO WEDS AM COMMUTE EVEN AS SNOW WINDS DOWN. RC/JEE //PREV DISCUSSION... 343 AM CDT THE TASTE OF SPRING YESTERDAY IS TRULY IN THE REAR VIEW MIRROR AS THE FORECAST FOCUS WAS ON WINTER STORM SET TO IMPACT THE AREA TONIGHT INTO EARLY WEDNESDAY. HAVE ISSUED A WINTER STORM WARNING CENTERED ON THE I-80 CORRIDOR...AND THAT INCLUDES CHICAGO...FOR THE COMBINATION OF HEAVY SNOWFALL RATES OF UP TO 2 INCHES PER HOUR...SNOW TOTALS AROUND SIX INCHES...AND WIND WHIPPED SNOW GREATLY REDUCING VISIBILITY. CONTINUE THE WATCH SOUTH OF THERE AND AN ADVISORY TO THE NORTH. THE PRIMARY UPPER LOW IS WELL-DEFINED THIS MORNING ACROSS WYOMING AND ADVANCING SOUTHEAST WITH OVER 200M HEIGHT FALLS AT 300MB SAMPLED LAST EVE. SECOND KEY SHORT WAVE IS DROPPING SOUTHWARD FROM MANITOBA. THE PHASING OF THESE SYSTEMS IS ANTICIPATED TO OCCUR ACROSS THE WESTERN GREAT LAKES OVERNIGHT INTO WEDNESDAY MORNING. AS OFTEN SEEN WITH PHASING SYSTEMS...FORCING FOR LIFT AND HEAVY PRECIP IS EXPECTED TO RAPIDLY INCREASE TONIGHT. NUMERICAL GUIDANCE HAS HAD SOME PRONOUNCED DIFFERENCES AND THAT CONTINUED INTO THE 11.00Z AND 11.06Z CYCLES...BUT IT IS IMPORTANT TO NOTE THAT ALL GUIDANCE DEPICT ALL THE INGREDIENTS FOR HEAVY SNOWFALL AND THAT ARE CONSISTENT WITH A PHASING SYSTEM. HAVE PREFERRED THE GLOBAL GUIDANCE SOLUTION OF MASS FIELDS AND TAKEN INTO ACCOUNT THE MRF AND LOCAL HIGH RES MODELS IDEAS OF MESOSCALE VERY HEAVY SNOWFALL RATES AND TIMING. BELIEVE THE MRF IS A LITTLE TOO ROBUST AND WIDESPREAD WITH ITS HEAVIEST QPF...BUT AGAIN THE IDEA OF HEAVY SNOWFALL WITH AMOUNTS EXCEEDING SIX INCHES IN AN AREA IS SUPPORTED. TODAY... THIS STILL LOOKS MAINLY DRY ACROSS THE FORECAST AREA WITH A VERY SHARP MID-LEVEL STATIONARY FRONT SAMPLED ON LAST EVES RAOBS BECOMING MORE ACTIVE AHEAD OF THE APPROACHING TROUGHS. EARLY MORNING RADAR MOSAIC INDICATES PRECIP FROM SD THROUGH WESTERN WI. THIS SHOULD ONLY INCH SOUTHWARD GRADUALLY TODAY. FRONTOGENESIS RESPONSE FROM EVEN THE MOST SOUTH HIGH RESOLUTION GUIDANCE WOULD KEEP RAIN NORTH OF THE AREA THROUGH MID-AFTERNOON. STILL SHOULD SEE PLENTY OF CLOUD COVER AND WITH NORTHEAST WINDS INCREASING AHEAD OF CYCLOGENESIS IN THE PLAINS...EXPECT THAT SURFACE TEMPERATURES WILL START TO LEVEL OUT AROUND THE NOON HOUR AND THEN BEGIN TO GRADUALLY FALL. ONSHORE FLOW INTO CHICAGO OFF THE ICE-COVERED LAKE MAY LEAD TO A MORE RAPID FALL DOWNTOWN. TONIGHT AND WEDNESDAY MORNING... IN RESPONSE TO THE AFOREMENTIONED PHASING...MAXIMUM HEIGHT FALLS ARE CENTERED DIRECTLY ON THE AREA TONIGHT WITH LIFT RAPIDLY INCREASING. THIS WILL EVOLVE THE LOW-LEVEL FEATURES EASTWARD WITH COPIOUS MOISTURE TRANSPORTED NORTH OF A 40-45 KT LOW-LEVEL JET. PRECIP FROM THE NORTH IS EXPECTED TO QUICKLY MOVE SOUTH...WHILE NEW PRECIP SHOULD DEVELOP JUST WEST OR OVER THE AREA THIS EVE. THE DEGREE OF FORCING AND COOL ADVECTION IN THE NORTHEAST QUADRANT OF THE SYSTEM WILL HELP TO COOL THE COLUMN FROM NORTH TO SOUTH FOR A TRANSITION OF RAIN TO SNOW...AND THIS WILL BE ESPECIALLY TRUE DURING THE MID EVE INTO EARLY OVERNIGHT AS THE MOST ROBUST FORCING MOVES IN. WOULD EXPECT SOME AREAS OF NORTHERN ILLINOIS MAY JUST BEGIN AS SNOW OR EXPERIENCE A VERY SHORT MIX. AS FOR AREAS ALONG AND SOUTH OF I-80...A COUPLE/SEVERAL HOUR WINDOW OF RAIN WILL BE LIKELY FIRST BEFORE TRANSITIONING TO A WET SNOW LATE THIS EVE INTO EARLY OVERNIGHT. THAT TIME PERIOD AFTER TRANSITION AND INTO OVERNIGHT IS MOST FAVORED FOR HEAVY SNOWFALL...WITH UPRIGHT INSTABILITY FORECAST BY GLOBAL MODELS TO REACH INTO THE CENTRAL FORECAST AREA...WHICH LINES UP WITH THE DEEPEST CONVERGENCE AND FOCUS NEAR I-80. THE 11.03Z SREF PROBABILITIES OF OVER ONE INCH PER HOUR SNOWFALL RATES ARE TO 70 PERCENT WHICH IS IMPRESSIVE AND MAKE SENSE...AND WOULD NOT BE SURPRISED TO SEE TEMPORARY TWO INCH PER HOUR OR HIGHER RATES LATE THIS EVE INTO OVERNIGHT. THE WINDS LOOK TO REALLY RAMP UP OVERNIGHT AROUND THE DEEPENING LOW...WITH 45 KT OF NORTHEAST FLOW ON THE NAM AND GFS AT 1000-2000 FT. EVEN WITH THE WET SNOW...EXPECT THAT THE BLOWING OF THE FALLING SNOW WILL CAUSE EVEN FURTHER REDUCED VISIBILITY...AND EVEN TEMPORARY WHITE OUT CONDITIONS IN THE HEAVIEST OF SNOWFALL RATES. BY WEDNESDAY MORNING SNOW SHOULD BE ENDING FROM WEST TO EAST...ALTHOUGH SOME PRETTY SOLID RATES COULD STILL BE OCCURRING IN EASTERN AREAS...INCLUDING POSSIBLY CHICAGO INTO THE EARLY PARTS OF THE MORNING COMMUTE. UNCERTAINTY ON END TIME OF SNOWFALL IS FAIRLY HIGH...BUT THE WINDS SHOULD CONTINUE AND SO EXPECT IMPACTS...AND THAT MAY BE ESPECIALLY TRUE NEAR THE LAKE SHORE WHERE THE WIND COULD GUST TO 40-45 MPH. THAT IS WHY RUN HEADLINES THROUGH NOON. WITH THE HIGH MOISTURE...AS DEPICTED BY MIXING RATIOS OF 4-6 G/KG AND PWATS OF AROUND 0.75 IN...THERE SHOULD NOT BE TOO MUCH OF A PROBLEM WITH SNOWFALL AMOUNTS IN THE MAXIMUM AREA TOPPING SIX INCHES...EVEN WITH THE QUICK MOVEMENT OF THE SYSTEM AND LOW SNOW-TO-LIQUID RATIOS. THE HIGHEST AMOUNTS COULD EXCEED 8 INCHES IN ISOLATED AREAS...BUT AGAIN LIMITED DURATION SHOULD PREVENT THAT FROM BEING TOO WIDESPREAD. HEADLINES... GIVEN RATES AND BLOWING OF THE FALLING SNOW...WITH BASICALLY A DOWNPOUR OF SNOW WITH CONCURRENT GUSTS OF 30+ MPH...HAVE OPTED TO GO WITH A WARNING FOR THE AREA WITH THE LONGEST DURATION OF SNOW....EVEN THOUGH NOT EVERYWHERE WILL SEE SIX PLUS INCHES OF SNOW. UNCERTAINTY OF SNOW DURATION IN THE FAR SOUTH LED TO CONTINUING THE WATCH. FURTHER NORTH HAVE AN ADVISORY...AND DID NOT INCLUDE ROCKFORD BECAUSE IT LOOKS LIKE SNOWFALL SHOULD HAVE ENDED BY MUCH OF IF NOT THE ENTIRE WED MORNING COMMUTE. IT IS CERTAINLY POSSIBLE ADJUSTMENTS TO THE NORTHERN END OF HEADLINES ARE MADE TODAY. WEDNESDAY NIGHT AND THURSDAY... NOT MUCH CHANGE MADE TO THIS PERIOD. WEDNESDAY NIGHT LOOKS TO BE PRETTY CHILLY WITH THE FRESH SNOW COVER AND DIMINISHING WINDS...AND IF THE SKY CAN REMAIN CLEAR THE LOWS MAY BE WITHIN FIVE DEGREES OF RECORD LOWS FOR MARCH 13TH. MTF EXTENDED FORECAST...FRIDAY THROUGH TUESDAY... 210 PM CDT... FOR THE EXTENDED FORECAST PERIOD...THE MAIN ISSUE WILL BE TEMPERATURES ACROSS THE REGION. THE LONGER RANGE GUIDANCE IS SUGGESTING THAT THE MAIN FEATURES OF INTEREST WILL BE A PAIR OF CLIPPER DROPPING OUT OF NORTHERN ALBERTA AND TRACKING ACROSS THE UPPER GREAT LAKES REGION. PERIODS OF WARMING WILL PRECEDE THE CLIPPERS WITH HIGHS ON FRIDAY IN THE MIDDLE 40S TO LOWER 50S. FOLLOWING A WEAK COLD FRONTAL PASSAGE ASSOCIATED WITH THE FIRST CLIPPER WILL BRING TEMPS BACK TO BELOW NORMAL FOR SUNDAY WITH HIGHS ONLY IN THE UPPER 20S TO MIDDLE 30S. TOWARD THE END OF THE FORECAST PERIOD...THERE IS THE POTENTIAL FOR TEMPERATURES TO REACH INTO THE LOWER 50S AHEAD OF THE SECOND CLIPPER. THERE MAY AND UP BEING SOME TIMING CHANGES WITH THESE SYSTEMS AS WE GET CLOSER TO THE EVENTS...BUT THE GENERAL SIGNAL IS FOR ABOVE NORMAL TEMPERATURES FOR MUCH OF THE EXTENDED FORECAST PERIOD...WITH THE EXCEPTION OF THE PERIOD FOLLOWING THE PASSAGE OF THE FIRST CLIPPER WHICH WILL BRING BACK A DIP INTO BELOW NORMAL TEMPERATURE RANGES. AS FOR THE PRECIPITATION OUTLOOK...THIS WILL BE HIGHLY DEPENDENT ON THE TRACKS OF THE CLIPPERS...BUT AT THIS POINT...IT APPEARS THAT THEY WILL TRACK TO FAR NORTH TO HAVE MUCH OF AN IMPACT ON NORTHERN ILLINOIS AND NORTHWEST INDIANA. SO...WILL CARRY DRY FORECAST FOR MUCH OF THE EXTENDED PERIOD...WITH ONLY SOME SLIGHT CHANCE POPS ON SUNDAY WITH THE FROPA ASSOCIATED WITH THE PASSAGE OF THE FIRST CLIPPER. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * NORTHEAST WINDS INCREASING TODAY AND TONIGHT WITH GUSTS OF 30-35 KT LIKELY TONIGHT INTO WEDNESDAY MORNING. * RAIN/SNOW MIX BY MID EVENING...RAPIDLY CHANGING OVER TO ALL SNOW SOON THERE AFTER. * RAPIDLY DETERIORATING CONDITIONS IN SNOW WITH VIS/CEILINGS FALLING TO LIFR/VLIFR. * PERIOD OF HEAVY SNOW WITH SIGNIFICANTLY REDUCED VIS LIKELY AFTER MIDNIGHT. * BLOWING SNOW OVERNIGHT INTO WEDNESDAY MORNING. RODRIGUEZ //DISCUSSION...UPDATED 18Z... VFR CONDITIONS AND AN INCREASING NORTHEAST WIND IN PLACE OVER THE TERMINALS EARLY THIS AFTERNOON AS APPROACHING LOW TO THE SOUTHWEST CONTINUES TO WORK ITS WAY TOWARDS THE AREA. WINDS WILL STEADILY INCREASE THROUGH THE AFTERNOON AND EVENING WITH HIGHEST GUSTS EXPECTED OVERNIGHT INTO WEDNESDAY MORNING. VFR CEILINGS WILL LOWER THIS AFTERNOON BUT THEN QUICKLY DETERIORATE AS BETTER FORCING ARRIVES THIS EVENING WITH MVFR CONDITIONS BECOMING IFR SOON THERE AFTER...WITH THESE CEILINGS THEN LIKELY FOR MOST OF THE NIGHT. A RAIN/SNOW MIX WILL SPREAD OVER THE TERMINALS THIS EVENING BUT EXPECT A RAPID CHANGE OVER TO ALL SNOW BASICALLY WITHIN AN HOUR OF ONSET. NO REAL CHANGES TO EXPECTED SNOW TONIGHT AND TIMING WITH THE 6-10Z TIME FRAME STILL THE BEST TIME FOR MORE MODERATE TO HEAVY SNOW. HAVE LEFT THE LOWEST VIS AT 1/2 MILE FOR ALL THE TERMINAL SITES...BUT WITH THEM LIKELY OBSERVING PERIODS OF 1/4 MILE OR EVEN LESS AT TIMES. EXPECT THIS HEAVIER SNOW TO BE MORE TIED TO CONVECTIVE ASPECTS...WITH UNCERTAINTY TO EXACT TIMING AND DURATION OF THIS HEAVIER SNOW ASSOCIATED WITH THIS FEATURE. MDW/GYY WOULD LIKELY HAVE THE BEST CHANCES FOR 1/4 MILE OR LESS VISIBILITY AS WELL AS FOR A LONGER DURATION AS THIS WILL BE A MORE FAVORED LOCATION FOR THE BEST SNOWFALL DEVELOPMENT. BUT ONCE AGAIN...WITH SOME UNCERTAINTY REMAINING...HAVE OPTED TO LEAVE OUT OF THE TAF AT THIS TIME BUT COULD SEE THIS LOWER VIS IN HEAVY SNOW ADDED LATER THIS EVENING. BEST SNOW DEVELOPMENT SHOULD EXIT THE TERMINALS BY EARLY WEDNESDAY MORNING...TAPERING OFF THROUGH THE MORNING WITH A SLOW IMPROVING TREND WITH CEILINGS. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION...AND RESULTANT BLOWING SNOW. * MEDIUM HIGH CONFIDENCE WITH RAIN/SNOW MIX TIMING AND CHANGE OVER TO SNOW. * MEDIUM CONFIDENCE WITH VIS/CEILING TRENDS. * MEDIUM HIGH CONFIDENCE WITH HEAVY SNOW...LOW MEDIUM CONFIDENCE WITH TIMING/DURATION. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... * WEDNESDAY NIGHT...DRY/VFR. * THURSDAY...DRY/VFR. GUSTY SOUTHWEST WINDS. * FRIDAY...DRY/VFR. GUSTY WESTERLY WINDS. * SATURDAY...DRY/VFR. * SUNDAY...SLIGHT CHANCE OF SNOW. * MONDAY...DRY/VFR. && .MARINE... 210 PM CDT LOW PRESSURE OVER THE CENTRAL PLAINS WILL CONTINUE TO DEEPEN AS IT TRACKS EAST ACROSS SOUTHERN ILLINOIS TONIGHT AND INTO THE OHIO VALLEY WEDNESDAY. AS THE LOW TRACKS SOUTH AND THEN SOUTHEAST OF THE LAKE...HIGH PRESSURE WILL ALSO BUILD ACROSS THE UPPER GREAT LAKES REGION...SETTING UP STRONG NORTH WINDS. THE COMBINATION OF A STRONG GRADIENT AND STRONG COLD ADVECTION WILL LEAD TO WINDS QUICKLY INCREASING TO GALES BY LATE THIS EVENING. THE LATEST GUIDANCE HAS BEEN RELATIVELY CONSISTENT IN INDICATING THE POTENTIAL FOR HIGH END GALES BY LATE WEDNESDAY MORNING AND EARLY AFTERNOON...WITH THE STRONGEST GALES OVER THE SOUTHERN PORTIONS OF THE LAKE...INCLUDING THE NEARSHORE WATERS. BY WEDNESDAY EVENING...THE HIGH PRESSURE WILL BEGIN TO SPREAD ACROSS LAKE MICHIGAN ALLOWING WINDS TO SUBSIDE BELOW GALE FORCE. BY THURSDAY NIGHT...THE HIGH WILL PUSH TO THE SOUTHEAST OF THE LAKE AS A CLIPPER DROPS OUT OF NORTHERN ALBERTA AND SWINGS JUST NORTH OF THE UPPER GREAT LAKES ON FRIDAY. WITH THE SFC HIGH SAGGING OFF THE SERN COAST...A PERIOD OF SWLY WINDS WILL DEVELOP AHEAD OF AN APPROACHING COLD FRONT TRAILING FROM THE CLIPPER. ANTICIPATE A PERIOD OF BRISK SLY TO SWLY WINDS FOR THURSDAY NIGHT THROUGH FRIDAY...BUT MORE GALES ARE NOT EXPECTED AT THIS TIME. AS THE CLIPPER TURNS NEWD INTO QUEBEC...IT WILL DRAG A WEAK COLD FRONT DOWN THE LAKE WITH ANOTHER ARCTIC HIGH BUILDING IN BEHIND THE FRONT. 25-30KT NORTH WINDS WILL SET UP FOLLOWING THE FROPA FOR SATURDAY NIGHT AND SUNDAY...BUT AS THE HIGH SPREADS ACROSS THE GREAT LAKES SUNDAY NIGHT...WINDS SHOULD BECOME MORE LIGHT AND VARIABLE. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER STORM WARNING...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032...10 PM TUESDAY TO 1 PM WEDNESDAY. WINTER WEATHER ADVISORY...ILZ006-ILZ008-ILZ010-ILZ011- ILZ012...10 PM TUESDAY TO 10 AM WEDNESDAY. WINTER STORM WATCH...ILZ033-ILZ039...1 AM WEDNESDAY TO 1 PM WEDNESDAY. IN...WINTER STORM WARNING...INZ001-INZ002...10 PM TUESDAY TO 1 PM WEDNESDAY. WINTER STORM WATCH...INZ010-INZ011-INZ019...1 AM WEDNESDAY TO 1 PM WEDNESDAY. LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741- LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872- LMZ874-LMZ876-LMZ878...MIDNIGHT WEDNESDAY TO 9 PM WEDNESDAY. GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567- LMZ868...3 AM WEDNESDAY TO 4 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
125 PM CDT TUE MAR 11 2014 .DISCUSSION... 1234 PM CDT WINTER STORM UPDATE... CONTINUING TO ASSESS 12Z MODEL DATA FOR IMPENDING WINTER STORM. SURFACE OBSERVATION ANALYSIS SHOWS 996 MB LOW IN CENTRAL KS ROUGHLY BETWEEN SLN AND HUT...NORTH OF LATEST RUN OF RAP MODEL. TRENDS SO FAR SUPPORT THE AXIS OF HEAVIEST SNOW IN GOING FORECAST AND HAVENT MADE ANY CHANGES TO THIS YET...WITH ONLY TWEAKS TO LATE AFTERNOON POPS AS BAROCLINIC ZONE STARTS TO SHIFT SOUTH AND RAIN COMMENCES IN FAR NORTHERN CWA. RAIN SHOULD QUICKLY FLIP OVER TO SNOW THIS EVENING IN NORTHERN ILLINOIS AS COLDER AIR FILTERS IN FROM THE NORTH. OF BIGGEST CONCERN WITH THE SNOW LATE TONIGHT IS THE BAND OF VERY STRONG 850-700 MB FGEN OVERLAID BY NEGATIVE EPV...AS WELL AS THE PRESENCE OF 50-100 J/KG OF MUCAPE. THIS HIGHLIGHTS POTENTIAL FOR CONVECTIVE SNOW BANDS AND RATES OF 2 INCHES PLUS PER HOUR WHEREVER THIS SETS UP. KEEPING TOTALS IN CHECK WILL BE PROGRESSIVE NATURE OF SYSTEM WITH MIDLEVEL TROUGH REMAINING OPEN...SO WOULD ONLY EXPECT A FEW HOUR PERIOD WITH THE REALLY HEAVY RATES IN ANY GIVEN AREA. NONETHELESS...COULD SEE SOME ISOLATED TOTALS TO OR EVEN A BIT ABOVE 8 INCHES IN WARNING AREA...WITH THIS MOST LIKELY TO OCCUR ROUGHLY ALONG AND A BIT EAST OF I-55 CORRIDOR. LIKELY BECAUSE OF BANDING POTENTIAL...HIGHER RES GUIDANCE SHOWING A VERY SHARP CUTOFF TO PRECIP IN NORTHERN CWA...AND THINK THIS IS OVERDONE...BUT THERE WILL BE A GRADIENT IN SNOW AMOUNTS ROUGHLY IN LINE WITH GOING FORECAST. FARTHER SOUTH IN WATCH AREA...UNCERTAINTY REMAINS OVER HOW FAST CHANGEOVER WILL OCCUR AND HOW MUCH PRECIP WILL FALL AFTER CHANGEOVER...SO WILL MAKE A DECISION ON HEADLINE FOR SOUTHEAST CWA WITH AFTERNOON ISSUANCE. FINALLY...WINDS REMAIN A SIGNIFICANT CONCERN AS WELL LATE TONIGHT INTO WEDNESDAY MORNING...WITH SOUNDINGS SUPPORTING NORTHERLY WIND GUSTS TO 40+ MPH. THIS WILL EXACERBATE IMPACTS TO WEDS AM COMMUTE EVEN AS SNOW WINDS DOWN. RC/JEE //PREV DISCUSSION... 343 AM CDT THE TASTE OF SPRING YESTERDAY IS TRULY IN THE REAR VIEW MIRROR AS THE FORECAST FOCUS WAS ON WINTER STORM SET TO IMPACT THE AREA TONIGHT INTO EARLY WEDNESDAY. HAVE ISSUED A WINTER STORM WARNING CENTERED ON THE I-80 CORRIDOR...AND THAT INCLUDES CHICAGO...FOR THE COMBINATION OF HEAVY SNOWFALL RATES OF UP TO 2 INCHES PER HOUR...SNOW TOTALS AROUND SIX INCHES...AND WIND WHIPPED SNOW GREATLY REDUCING VISIBILITY. CONTINUE THE WATCH SOUTH OF THERE AND AN ADVISORY TO THE NORTH. THE PRIMARY UPPER LOW IS WELL-DEFINED THIS MORNING ACROSS WYOMING AND ADVANCING SOUTHEAST WITH OVER 200M HEIGHT FALLS AT 300MB SAMPLED LAST EVE. SECOND KEY SHORT WAVE IS DROPPING SOUTHWARD FROM MANITOBA. THE PHASING OF THESE SYSTEMS IS ANTICIPATED TO OCCUR ACROSS THE WESTERN GREAT LAKES OVERNIGHT INTO WEDNESDAY MORNING. AS OFTEN SEEN WITH PHASING SYSTEMS...FORCING FOR LIFT AND HEAVY PRECIP IS EXPECTED TO RAPIDLY INCREASE TONIGHT. NUMERICAL GUIDANCE HAS HAD SOME PRONOUNCED DIFFERENCES AND THAT CONTINUED INTO THE 11.00Z AND 11.06Z CYCLES...BUT IT IS IMPORTANT TO NOTE THAT ALL GUIDANCE DEPICT ALL THE INGREDIENTS FOR HEAVY SNOWFALL AND THAT ARE CONSISTENT WITH A PHASING SYSTEM. HAVE PREFERRED THE GLOBAL GUIDANCE SOLUTION OF MASS FIELDS AND TAKEN INTO ACCOUNT THE MRF AND LOCAL HIGH RES MODELS IDEAS OF MESOSCALE VERY HEAVY SNOWFALL RATES AND TIMING. BELIEVE THE MRF IS A LITTLE TOO ROBUST AND WIDESPREAD WITH ITS HEAVIEST QPF...BUT AGAIN THE IDEA OF HEAVY SNOWFALL WITH AMOUNTS EXCEEDING SIX INCHES IN AN AREA IS SUPPORTED. TODAY... THIS STILL LOOKS MAINLY DRY ACROSS THE FORECAST AREA WITH A VERY SHARP MID-LEVEL STATIONARY FRONT SAMPLED ON LAST EVES RAOBS BECOMING MORE ACTIVE AHEAD OF THE APPROACHING TROUGHS. EARLY MORNING RADAR MOSAIC INDICATES PRECIP FROM SD THROUGH WESTERN WI. THIS SHOULD ONLY INCH SOUTHWARD GRADUALLY TODAY. FRONTOGENESIS RESPONSE FROM EVEN THE MOST SOUTH HIGH RESOLUTION GUIDANCE WOULD KEEP RAIN NORTH OF THE AREA THROUGH MID-AFTERNOON. STILL SHOULD SEE PLENTY OF CLOUD COVER AND WITH NORTHEAST WINDS INCREASING AHEAD OF CYCLOGENESIS IN THE PLAINS...EXPECT THAT SURFACE TEMPERATURES WILL START TO LEVEL OUT AROUND THE NOON HOUR AND THEN BEGIN TO GRADUALLY FALL. ONSHORE FLOW INTO CHICAGO OFF THE ICE-COVERED LAKE MAY LEAD TO A MORE RAPID FALL DOWNTOWN. TONIGHT AND WEDNESDAY MORNING... IN RESPONSE TO THE AFOREMENTIONED PHASING...MAXIMUM HEIGHT FALLS ARE CENTERED DIRECTLY ON THE AREA TONIGHT WITH LIFT RAPIDLY INCREASING. THIS WILL EVOLVE THE LOW-LEVEL FEATURES EASTWARD WITH COPIOUS MOISTURE TRANSPORTED NORTH OF A 40-45 KT LOW-LEVEL JET. PRECIP FROM THE NORTH IS EXPECTED TO QUICKLY MOVE SOUTH...WHILE NEW PRECIP SHOULD DEVELOP JUST WEST OR OVER THE AREA THIS EVE. THE DEGREE OF FORCING AND COOL ADVECTION IN THE NORTHEAST QUADRANT OF THE SYSTEM WILL HELP TO COOL THE COLUMN FROM NORTH TO SOUTH FOR A TRANSITION OF RAIN TO SNOW...AND THIS WILL BE ESPECIALLY TRUE DURING THE MID EVE INTO EARLY OVERNIGHT AS THE MOST ROBUST FORCING MOVES IN. WOULD EXPECT SOME AREAS OF NORTHERN ILLINOIS MAY JUST BEGIN AS SNOW OR EXPERIENCE A VERY SHORT MIX. AS FOR AREAS ALONG AND SOUTH OF I-80...A COUPLE/SEVERAL HOUR WINDOW OF RAIN WILL BE LIKELY FIRST BEFORE TRANSITIONING TO A WET SNOW LATE THIS EVE INTO EARLY OVERNIGHT. THAT TIME PERIOD AFTER TRANSITION AND INTO OVERNIGHT IS MOST FAVORED FOR HEAVY SNOWFALL...WITH UPRIGHT INSTABILITY FORECAST BY GLOBAL MODELS TO REACH INTO THE CENTRAL FORECAST AREA...WHICH LINES UP WITH THE DEEPEST CONVERGENCE AND FOCUS NEAR I-80. THE 11.03Z SREF PROBABILITIES OF OVER ONE INCH PER HOUR SNOWFALL RATES ARE TO 70 PERCENT WHICH IS IMPRESSIVE AND MAKE SENSE...AND WOULD NOT BE SURPRISED TO SEE TEMPORARY TWO INCH PER HOUR OR HIGHER RATES LATE THIS EVE INTO OVERNIGHT. THE WINDS LOOK TO REALLY RAMP UP OVERNIGHT AROUND THE DEEPENING LOW...WITH 45 KT OF NORTHEAST FLOW ON THE NAM AND GFS AT 1000-2000 FT. EVEN WITH THE WET SNOW...EXPECT THAT THE BLOWING OF THE FALLING SNOW WILL CAUSE EVEN FURTHER REDUCED VISIBILITY...AND EVEN TEMPORARY WHITE OUT CONDITIONS IN THE HEAVIEST OF SNOWFALL RATES. BY WEDNESDAY MORNING SNOW SHOULD BE ENDING FROM WEST TO EAST...ALTHOUGH SOME PRETTY SOLID RATES COULD STILL BE OCCURRING IN EASTERN AREAS...INCLUDING POSSIBLY CHICAGO INTO THE EARLY PARTS OF THE MORNING COMMUTE. UNCERTAINTY ON END TIME OF SNOWFALL IS FAIRLY HIGH...BUT THE WINDS SHOULD CONTINUE AND SO EXPECT IMPACTS...AND THAT MAY BE ESPECIALLY TRUE NEAR THE LAKE SHORE WHERE THE WIND COULD GUST TO 40-45 MPH. THAT IS WHY RUN HEADLINES THROUGH NOON. WITH THE HIGH MOISTURE...AS DEPICTED BY MIXING RATIOS OF 4-6 G/KG AND PWATS OF AROUND 0.75 IN...THERE SHOULD NOT BE TOO MUCH OF A PROBLEM WITH SNOWFALL AMOUNTS IN THE MAXIMUM AREA TOPPING SIX INCHES...EVEN WITH THE QUICK MOVEMENT OF THE SYSTEM AND LOW SNOW-TO-LIQUID RATIOS. THE HIGHEST AMOUNTS COULD EXCEED 8 INCHES IN ISOLATED AREAS...BUT AGAIN LIMITED DURATION SHOULD PREVENT THAT FROM BEING TOO WIDESPREAD. HEADLINES... GIVEN RATES AND BLOWING OF THE FALLING SNOW...WITH BASICALLY A DOWNPOUR OF SNOW WITH CONCURRENT GUSTS OF 30+ MPH...HAVE OPTED TO GO WITH A WARNING FOR THE AREA WITH THE LONGEST DURATION OF SNOW....EVEN THOUGH NOT EVERYWHERE WILL SEE SIX PLUS INCHES OF SNOW. UNCERTAINTY OF SNOW DURATION IN THE FAR SOUTH LED TO CONTINUING THE WATCH. FURTHER NORTH HAVE AN ADVISORY...AND DID NOT INCLUDE ROCKFORD BECAUSE IT LOOKS LIKE SNOWFALL SHOULD HAVE ENDED BY MUCH OF IF NOT THE ENTIRE WED MORNING COMMUTE. IT IS CERTAINLY POSSIBLE ADJUSTMENTS TO THE NORTHERN END OF HEADLINES ARE MADE TODAY. WEDNESDAY NIGHT AND THURSDAY... NOT MUCH CHANGE MADE TO THIS PERIOD. WEDNESDAY NIGHT LOOKS TO BE PRETTY CHILLY WITH THE FRESH SNOW COVER AND DIMINISHING WINDS...AND IF THE SKY CAN REMAIN CLEAR THE LOWS MAY BE WITHIN FIVE DEGREES OF RECORD LOWS FOR MARCH 13TH. MTF EXTENDED PERIOD...FRIDAY THROUGH MONDAY... AN AMPLIFIED LARGE SCALE UPPER LEVEL WEATHER PATTERN WILL REMAIN THE MAIN STORY DURING THE EXTENDED PERIOD. THIS WILL LIKELY FEATURE POSITIVE HEIGHT ANOMALIES ACROSS THE EASTERN PACIFIC AND THE PACIFIC COAST OF THE CONUS...AND BELOW AVERAGE HEIGHTS ACROSS THE EASTERN CONUS. ULTIMATELY THIS WILL RESULT IN BELOW AVERAGE TEMPERATURES DURING MUCH OF THE EXTEND PERIOD. IT APPEARS FRIDAY WILL BE THE WARMEST DAY OF THE EXTENDED. A CLIPPER TYPE SYSTEM IS EXPECTED TO TRACK EASTWARD ACROSS THE UPPER GREAT LAKES REGION ON FRIDAY...AND THIS SHOULD RESULT IN BREEZE...BUT MILD...SOUTHWESTERLY FLOW ACROSS THE REGION. IT APPEARS TEMPERATURES COULD WARM INTO THE 50S...BUT ANY REMAINING SNOW COVER FROM THE SNOWFALL TONIGHT MAY HINDER THE MAGNITUDE OF WARMING SOME. THIS WARM AIR WILL BE SHORT LIVED AS COLDER AIR WILL LIKELY BEGIN TO SPILL BACK SOUTHWARD ACROSS THE AREA BY SATURDAY AS A COLD FRONT DROPS ACROSS THE AREA. SOME LIGHT SNOW SHOWERS MAY ACCOMPANY THIS COLDER AIR PUSH FRIDAY NIGHT. GUIDANCE IS HINTING AT DECENT SHORT WAVE TROUGH DIGGING SOUTHEASTWARD ACROSS SOUTHERN WISCONSIN DURING THIS TIME. IN SPITE OF THIS...I HAVE CHOSEN TO LEAVE THE FORECAST DRY AT THIS TIME. A VERY ACTIVE JET ACROSS THE PACIFIC WILL LIKELY CONTINUE TO DRIVE DISTURBANCES EASTWARD ATOP A BUILDING WESTERN CONUS RIDGE INTO NEXT WEEK. ALTHOUGH THE ACTUAL TIMING AND EVOLUTION OF THESE DISTURBANCES IS HIGHLY UNCERTAIN AT THIS JUNCTURE...IT DOES APPEAR THAT A NORTHWESTERLY UPPER LEVEL PATTERN ACROSS THE CENTRAL CONUS COULD PRODUCE SOME ADDITIONAL CHANCES OF SNOW FOR PORTIONS OF THE REGION LATER IN THE WEEKEND...DEPENDING ON THE ACTUALLY TRACK. WITH THIS IN MIND...I HAVE LEFT SOME LOW END POPS IN FOR LATER IN THE WEEKEND. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * NORTHEAST WINDS INCREASING TODAY AND TONIGHT WITH GUSTS OF 30-35 KT LIKELY TONIGHT INTO WEDNESDAY MORNING. * RAIN/SNOW MIX BY MID EVENING...RAPIDLY CHANGING OVER TO ALL SNOW SOON THERE AFTER. * RAPIDLY DETERIORATING CONDITIONS IN SNOW WITH VIS/CEILINGS FALLING TO LIFR/VLIFR. * PERIOD OF HEAVY SNOW WITH SIGNIFICANTLY REDUCED VIS LIKELY AFTER MIDNIGHT. * BLOWING SNOW OVERNIGHT INTO WEDNESDAY MORNING. RODRIGUEZ //DISCUSSION...UPDATED 18Z... VFR CONDITIONS AND AN INCREASING NORTHEAST WIND IN PLACE OVER THE TERMINALS EARLY THIS AFTERNOON AS APPROACHING LOW TO THE SOUTHWEST CONTINUES TO WORK ITS WAY TOWARDS THE AREA. WINDS WILL STEADILY INCREASE THROUGH THE AFTERNOON AND EVENING WITH HIGHEST GUSTS EXPECTED OVERNIGHT INTO WEDNESDAY MORNING. VFR CEILINGS WILL LOWER THIS AFTERNOON BUT THEN QUICKLY DETERIORATE AS BETTER FORCING ARRIVES THIS EVENING WITH MVFR CONDITIONS BECOMING IFR SOON THERE AFTER...WITH THESE CEILINGS THEN LIKELY FOR MOST OF THE NIGHT. A RAIN/SNOW MIX WILL SPREAD OVER THE TERMINALS THIS EVENING BUT EXPECT A RAPID CHANGE OVER TO ALL SNOW BASICALLY WITHIN AN HOUR OF ONSET. NO REAL CHANGES TO EXPECTED SNOW TONIGHT AND TIMING WITH THE 6-10Z TIME FRAME STILL THE BEST TIME FOR MORE MODERATE TO HEAVY SNOW. HAVE LEFT THE LOWEST VIS AT 1/2 MILE FOR ALL THE TERMINAL SITES...BUT WITH THEM LIKELY OBSERVING PERIODS OF 1/4 MILE OR EVEN LESS AT TIMES. EXPECT THIS HEAVIER SNOW TO BE MORE TIED TO CONVECTIVE ASPECTS...WITH UNCERTAINTY TO EXACT TIMING AND DURATION OF THIS HEAVIER SNOW ASSOCIATED WITH THIS FEATURE. MDW/GYY WOULD LIKELY HAVE THE BEST CHANCES FOR 1/4 MILE OR LESS VISIBILITY AS WELL AS FOR A LONGER DURATION AS THIS WILL BE A MORE FAVORED LOCATION FOR THE BEST SNOWFALL DEVELOPMENT. BUT ONCE AGAIN...WITH SOME UNCERTAINTY REMAINING...HAVE OPTED TO LEAVE OUT OF THE TAF AT THIS TIME BUT COULD SEE THIS LOWER VIS IN HEAVY SNOW ADDED LATER THIS EVENING. BEST SNOW DEVELOPMENT SHOULD EXIT THE TERMINALS BY EARLY WEDNESDAY MORNING...TAPERING OFF THROUGH THE MORNING WITH A SLOW IMPROVING TREND WITH CEILINGS. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION...AND RESULTANT BLOWING SNOW. * MEDIUM HIGH CONFIDENCE WITH RAIN/SNOW MIX TIMING AND CHANGE OVER TO SNOW. * MEDIUM CONFIDENCE WITH VIS/CEILING TRENDS. * MEDIUM HIGH CONFIDENCE WITH HEAVY SNOW...LOW MEDIUM CONFIDENCE WITH TIMING/DURATION. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... * WEDNESDAY NIGHT...DRY/VFR. * THURSDAY...DRY/VFR. GUSTY SOUTHWEST WINDS. * FRIDAY...DRY/VFR. GUSTY WESTERLY WINDS. * SATURDAY...DRY/VFR. * SUNDAY...SLIGHT CHANCE OF SNOW. * MONDAY...DRY/VFR. && .MARINE... 330 AM...LOW PRESSURE CURRENTLY OVER THE WESTERN PLAINS WILL MOVE EAST TO SOUTHERN ILLINOIS LATE THIS EVENING AND THEN DEEPEN AS IT REACHES NEW ENGLAND WEDNESDAY NIGHT. THE GRADIENT WILL TIGHTEN AS THIS LOW PASSES SOUTH OF LAKE MICHIGAN WITH NORTHERLY WINDS STEADILY INCREASING FROM THIS AFTERNOON INTO EARLY WEDNESDAY MORNING. GALES APPEAR TO BEGIN LATE THIS EVENING AND INCREASE TO 45 KTS OVERNIGHT AND CONTINUE THROUGH MIDDAY WEDNESDAY...SLOWLY DIMINISHING WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING. OTHER THAN TWEAKING WIND SPEEDS/ GUSTS UP...NO SIGNIFICANT CHANGES TO GOING FORECAST/GRIDS OR HEADLINES. WINDS WILL QUICKLY DIMINISH WEDNESDAY NIGHT/EARLY THURSDAY MORNING AS A RIDGE OF HIGH PRESSURE MOVES ACROSS THE LAKE. WINDS THEN TURN SOUTHWESTERLY AND INCREASE TO 30 KTS AS LOW PRESSURE MOVES ACROSS ONTARIO THURSDAY NIGHT AND FRIDAY...WITH A TRAILING COLD FRONT FROM THIS LOW MOVING ACROSS THE WESTERN LAKES FRIDAY AFTERNOON INTO FRIDAY EVENING. VISIBLE SATELLITE IMAGERY FROM MONDAY SHOWS SOME OPEN WATER IN THE ILLINOIS NEARSHORE ZONES AND HAVE ACCOUNTED FOR THIS WITH WAVE HEIGHTS IN THIS MORNING/S FORECAST. HOWEVER...WITH THE EXPECTED STRONG NORTHERLY WINDS...ICE IN THE OPEN WATERS IS EXPECTED TO BE PUSHED BACK TO THE ILLINOIS SHORE TONIGHT. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER STORM WARNING...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032...10 PM TUESDAY TO 1 PM WEDNESDAY. WINTER WEATHER ADVISORY...ILZ006-ILZ008-ILZ010-ILZ011- ILZ012...10 PM TUESDAY TO 10 AM WEDNESDAY. WINTER STORM WATCH...ILZ033-ILZ039...1 AM WEDNESDAY TO 1 PM WEDNESDAY. IN...WINTER STORM WARNING...INZ001-INZ002...10 PM TUESDAY TO 1 PM WEDNESDAY. WINTER STORM WATCH...INZ010-INZ011-INZ019...1 AM WEDNESDAY TO 1 PM WEDNESDAY. LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741- LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872- LMZ874-LMZ876-LMZ878...MIDNIGHT WEDNESDAY TO 9 PM WEDNESDAY. GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567- LMZ868...3 AM WEDNESDAY TO 4 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1234 PM CDT TUE MAR 11 2014 .DISCUSSION... 1234 PM CDT WINTER STORM UPDATE... CONTINUING TO ASSESS 12Z MODEL DATA FOR IMPENDING WINTER STORM. SURFACE OBSERVATION ANALYSIS SHOWS 996 MB LOW IN CENTRAL KS ROUGHLY BETWEEN SLN AND HUT...NORTH OF LATEST RUN OF RAP MODEL. TRENDS SO FAR SUPPORT THE AXIS OF HEAVIEST SNOW IN GOING FORECAST AND HAVENT MADE ANY CHANGES TO THIS YET...WITH ONLY TWEAKS TO LATE AFTERNOON POPS AS BAROCLINIC ZONE STARTS TO SHIFT SOUTH AND RAIN COMMENCES IN FAR NORTHERN CWA. RAIN SHOULD QUICKLY FLIP OVER TO SNOW THIS EVENING IN NORTHERN ILLINOIS AS COLDER AIR FILTERS IN FROM THE NORTH. OF BIGGEST CONCERN WITH THE SNOW LATE TONIGHT IS THE BAND OF VERY STRONG 850-700 MB FGEN OVERLAID BY NEGATIVE EPV...AS WELL AS THE PRESENCE OF 50-100 J/KG OF MUCAPE. THIS HIGHLIGHTS POTENTIAL FOR CONVECTIVE SNOW BANDS AND RATES OF 2 INCHES PLUS PER HOUR WHEREVER THIS SETS UP. KEEPING TOTALS IN CHECK WILL BE PROGRESSIVE NATURE OF SYSTEM WITH MIDLEVEL TROUGH REMAINING OPEN...SO WOULD ONLY EXPECT A FEW HOUR PERIOD WITH THE REALLY HEAVY RATES IN ANY GIVEN AREA. NONETHELESS...COULD SEE SOME ISOLATED TOTALS TO OR EVEN A BIT ABOVE 8 INCHES IN WARNING AREA...WITH THIS MOST LIKELY TO OCCUR ROUGHLY ALONG AND A BIT EAST OF I-55 CORRIDOR. LIKELY BECAUSE OF BANDING POTENTIAL...HIGHER RES GUIDANCE SHOWING A VERY SHARP CUTOFF TO PRECIP IN NORTHERN CWA...AND THINK THIS IS OVERDONE...BUT THERE WILL BE A GRADIENT IN SNOW AMOUNTS ROUGHLY IN LINE WITH GOING FORECAST. FARTHER SOUTH IN WATCH AREA...UNCERTAINTY REMAINS OVER HOW FAST CHANGEOVER WILL OCCUR AND HOW MUCH PRECIP WILL FALL AFTER CHANGEOVER...SO WILL MAKE A DECISION ON HEADLINE FOR SOUTHEAST CWA WITH AFTERNOON ISSUANCE. FINALLY...WINDS REMAIN A SIGNIFICANT CONCERN AS WELL LATE TONIGHT INTO WEDNESDAY MORNING...WITH SOUNDINGS SUPPORTING NORTHERLY WIND GUSTS TO 40+ MPH. THIS WILL EXACERBATE IMPACTS TO WEDS AM COMMUTE EVEN AS SNOW WINDS DOWN. RC/JEE && .PREV DISCUSSION... 343 AM CDT THE TASTE OF SPRING YESTERDAY IS TRULY IN THE REAR VIEW MIRROR AS THE FORECAST FOCUS WAS ON WINTER STORM SET TO IMPACT THE AREA TONIGHT INTO EARLY WEDNESDAY. HAVE ISSUED A WINTER STORM WARNING CENTERED ON THE I-80 CORRIDOR...AND THAT INCLUDES CHICAGO...FOR THE COMBINATION OF HEAVY SNOWFALL RATES OF UP TO 2 INCHES PER HOUR...SNOW TOTALS AROUND SIX INCHES...AND WIND WHIPPED SNOW GREATLY REDUCING VISIBILITY. CONTINUE THE WATCH SOUTH OF THERE AND AN ADVISORY TO THE NORTH. THE PRIMARY UPPER LOW IS WELL-DEFINED THIS MORNING ACROSS WYOMING AND ADVANCING SOUTHEAST WITH OVER 200M HEIGHT FALLS AT 300MB SAMPLED LAST EVE. SECOND KEY SHORT WAVE IS DROPPING SOUTHWARD FROM MANITOBA. THE PHASING OF THESE SYSTEMS IS ANTICIPATED TO OCCUR ACROSS THE WESTERN GREAT LAKES OVERNIGHT INTO WEDNESDAY MORNING. AS OFTEN SEEN WITH PHASING SYSTEMS...FORCING FOR LIFT AND HEAVY PRECIP IS EXPECTED TO RAPIDLY INCREASE TONIGHT. NUMERICAL GUIDANCE HAS HAD SOME PRONOUNCED DIFFERENCES AND THAT CONTINUED INTO THE 11.00Z AND 11.06Z CYCLES...BUT IT IS IMPORTANT TO NOTE THAT ALL GUIDANCE DEPICT ALL THE INGREDIENTS FOR HEAVY SNOWFALL AND THAT ARE CONSISTENT WITH A PHASING SYSTEM. HAVE PREFERRED THE GLOBAL GUIDANCE SOLUTION OF MASS FIELDS AND TAKEN INTO ACCOUNT THE MRF AND LOCAL HIGH RES MODELS IDEAS OF MESOSCALE VERY HEAVY SNOWFALL RATES AND TIMING. BELIEVE THE MRF IS A LITTLE TOO ROBUST AND WIDESPREAD WITH ITS HEAVIEST QPF...BUT AGAIN THE IDEA OF HEAVY SNOWFALL WITH AMOUNTS EXCEEDING SIX INCHES IN AN AREA IS SUPPORTED. TODAY... THIS STILL LOOKS MAINLY DRY ACROSS THE FORECAST AREA WITH A VERY SHARP MID-LEVEL STATIONARY FRONT SAMPLED ON LAST EVES RAOBS BECOMING MORE ACTIVE AHEAD OF THE APPROACHING TROUGHS. EARLY MORNING RADAR MOSAIC INDICATES PRECIP FROM SD THROUGH WESTERN WI. THIS SHOULD ONLY INCH SOUTHWARD GRADUALLY TODAY. FRONTOGENESIS RESPONSE FROM EVEN THE MOST SOUTH HIGH RESOLUTION GUIDANCE WOULD KEEP RAIN NORTH OF THE AREA THROUGH MID-AFTERNOON. STILL SHOULD SEE PLENTY OF CLOUD COVER AND WITH NORTHEAST WINDS INCREASING AHEAD OF CYCLOGENESIS IN THE PLAINS...EXPECT THAT SURFACE TEMPERATURES WILL START TO LEVEL OUT AROUND THE NOON HOUR AND THEN BEGIN TO GRADUALLY FALL. ONSHORE FLOW INTO CHICAGO OFF THE ICE-COVERED LAKE MAY LEAD TO A MORE RAPID FALL DOWNTOWN. TONIGHT AND WEDNESDAY MORNING... IN RESPONSE TO THE AFOREMENTIONED PHASING...MAXIMUM HEIGHT FALLS ARE CENTERED DIRECTLY ON THE AREA TONIGHT WITH LIFT RAPIDLY INCREASING. THIS WILL EVOLVE THE LOW-LEVEL FEATURES EASTWARD WITH COPIOUS MOISTURE TRANSPORTED NORTH OF A 40-45 KT LOW-LEVEL JET. PRECIP FROM THE NORTH IS EXPECTED TO QUICKLY MOVE SOUTH...WHILE NEW PRECIP SHOULD DEVELOP JUST WEST OR OVER THE AREA THIS EVE. THE DEGREE OF FORCING AND COOL ADVECTION IN THE NORTHEAST QUADRANT OF THE SYSTEM WILL HELP TO COOL THE COLUMN FROM NORTH TO SOUTH FOR A TRANSITION OF RAIN TO SNOW...AND THIS WILL BE ESPECIALLY TRUE DURING THE MID EVE INTO EARLY OVERNIGHT AS THE MOST ROBUST FORCING MOVES IN. WOULD EXPECT SOME AREAS OF NORTHERN ILLINOIS MAY JUST BEGIN AS SNOW OR EXPERIENCE A VERY SHORT MIX. AS FOR AREAS ALONG AND SOUTH OF I-80...A COUPLE/SEVERAL HOUR WINDOW OF RAIN WILL BE LIKELY FIRST BEFORE TRANSITIONING TO A WET SNOW LATE THIS EVE INTO EARLY OVERNIGHT. THAT TIME PERIOD AFTER TRANSITION AND INTO OVERNIGHT IS MOST FAVORED FOR HEAVY SNOWFALL...WITH UPRIGHT INSTABILITY FORECAST BY GLOBAL MODELS TO REACH INTO THE CENTRAL FORECAST AREA...WHICH LINES UP WITH THE DEEPEST CONVERGENCE AND FOCUS NEAR I-80. THE 11.03Z SREF PROBABILITIES OF OVER ONE INCH PER HOUR SNOWFALL RATES ARE TO 70 PERCENT WHICH IS IMPRESSIVE AND MAKE SENSE...AND WOULD NOT BE SURPRISED TO SEE TEMPORARY TWO INCH PER HOUR OR HIGHER RATES LATE THIS EVE INTO OVERNIGHT. THE WINDS LOOK TO REALLY RAMP UP OVERNIGHT AROUND THE DEEPENING LOW...WITH 45 KT OF NORTHEAST FLOW ON THE NAM AND GFS AT 1000-2000 FT. EVEN WITH THE WET SNOW...EXPECT THAT THE BLOWING OF THE FALLING SNOW WILL CAUSE EVEN FURTHER REDUCED VISIBILITY...AND EVEN TEMPORARY WHITE OUT CONDITIONS IN THE HEAVIEST OF SNOWFALL RATES. BY WEDNESDAY MORNING SNOW SHOULD BE ENDING FROM WEST TO EAST...ALTHOUGH SOME PRETTY SOLID RATES COULD STILL BE OCCURRING IN EASTERN AREAS...INCLUDING POSSIBLY CHICAGO INTO THE EARLY PARTS OF THE MORNING COMMUTE. UNCERTAINTY ON END TIME OF SNOWFALL IS FAIRLY HIGH...BUT THE WINDS SHOULD CONTINUE AND SO EXPECT IMPACTS...AND THAT MAY BE ESPECIALLY TRUE NEAR THE LAKE SHORE WHERE THE WIND COULD GUST TO 40-45 MPH. THAT IS WHY RUN HEADLINES THROUGH NOON. WITH THE HIGH MOISTURE...AS DEPICTED BY MIXING RATIOS OF 4-6 G/KG AND PWATS OF AROUND 0.75 IN...THERE SHOULD NOT BE TOO MUCH OF A PROBLEM WITH SNOWFALL AMOUNTS IN THE MAXIMUM AREA TOPPING SIX INCHES...EVEN WITH THE QUICK MOVEMENT OF THE SYSTEM AND LOW SNOW-TO-LIQUID RATIOS. THE HIGHEST AMOUNTS COULD EXCEED 8 INCHES IN ISOLATED AREAS...BUT AGAIN LIMITED DURATION SHOULD PREVENT THAT FROM BEING TOO WIDESPREAD. HEADLINES... GIVEN RATES AND BLOWING OF THE FALLING SNOW...WITH BASICALLY A DOWNPOUR OF SNOW WITH CONCURRENT GUSTS OF 30+ MPH...HAVE OPTED TO GO WITH A WARNING FOR THE AREA WITH THE LONGEST DURATION OF SNOW....EVEN THOUGH NOT EVERYWHERE WILL SEE SIX PLUS INCHES OF SNOW. UNCERTAINTY OF SNOW DURATION IN THE FAR SOUTH LED TO CONTINUING THE WATCH. FURTHER NORTH HAVE AN ADVISORY...AND DID NOT INCLUDE ROCKFORD BECAUSE IT LOOKS LIKE SNOWFALL SHOULD HAVE ENDED BY MUCH OF IF NOT THE ENTIRE WED MORNING COMMUTE. IT IS CERTAINLY POSSIBLE ADJUSTMENTS TO THE NORTHERN END OF HEADLINES ARE MADE TODAY. WEDNESDAY NIGHT AND THURSDAY... NOT MUCH CHANGE MADE TO THIS PERIOD. WEDNESDAY NIGHT LOOKS TO BE PRETTY CHILLY WITH THE FRESH SNOW COVER AND DIMINISHING WINDS...AND IF THE SKY CAN REMAIN CLEAR THE LOWS MAY BE WITHIN FIVE DEGREES OF RECORD LOWS FOR MARCH 13TH. MTF EXTENDED PERIOD...FRIDAY THROUGH MONDAY... AN AMPLIFIED LARGE SCALE UPPER LEVEL WEATHER PATTERN WILL REMAIN THE MAIN STORY DURING THE EXTENDED PERIOD. THIS WILL LIKELY FEATURE POSITIVE HEIGHT ANOMALIES ACROSS THE EASTERN PACIFIC AND THE PACIFIC COAST OF THE CONUS...AND BELOW AVERAGE HEIGHTS ACROSS THE EASTERN CONUS. ULTIMATELY THIS WILL RESULT IN BELOW AVERAGE TEMPERATURES DURING MUCH OF THE EXTEND PERIOD. IT APPEARS FRIDAY WILL BE THE WARMEST DAY OF THE EXTENDED. A CLIPPER TYPE SYSTEM IS EXPECTED TO TRACK EASTWARD ACROSS THE UPPER GREAT LAKES REGION ON FRIDAY...AND THIS SHOULD RESULT IN BREEZE...BUT MILD...SOUTHWESTERLY FLOW ACROSS THE REGION. IT APPEARS TEMPERATURES COULD WARM INTO THE 50S...BUT ANY REMAINING SNOW COVER FROM THE SNOWFALL TONIGHT MAY HINDER THE MAGNITUDE OF WARMING SOME. THIS WARM AIR WILL BE SHORT LIVED AS COLDER AIR WILL LIKELY BEGIN TO SPILL BACK SOUTHWARD ACROSS THE AREA BY SATURDAY AS A COLD FRONT DROPS ACROSS THE AREA. SOME LIGHT SNOW SHOWERS MAY ACCOMPANY THIS COLDER AIR PUSH FRIDAY NIGHT. GUIDANCE IS HINTING AT DECENT SHORT WAVE TROUGH DIGGING SOUTHEASTWARD ACROSS SOUTHERN WISCONSIN DURING THIS TIME. IN SPITE OF THIS...I HAVE CHOSEN TO LEAVE THE FORECAST DRY AT THIS TIME. A VERY ACTIVE JET ACROSS THE PACIFIC WILL LIKELY CONTINUE TO DRIVE DISTURBANCES EASTWARD ATOP A BUILDING WESTERN CONUS RIDGE INTO NEXT WEEK. ALTHOUGH THE ACTUAL TIMING AND EVOLUTION OF THESE DISTURBANCES IS HIGHLY UNCERTAIN AT THIS JUNCTURE...IT DOES APPEAR THAT A NORTHWESTERLY UPPER LEVEL PATTERN ACROSS THE CENTRAL CONUS COULD PRODUCE SOME ADDITIONAL CHANCES OF SNOW FOR PORTIONS OF THE REGION LATER IN THE WEEKEND...DEPENDING ON THE ACTUALLY TRACK. WITH THIS IN MIND...I HAVE LEFT SOME LOW END POPS IN FOR LATER IN THE WEEKEND. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * GUSTY NORTHEAST WINDS 15-18 KTS THIS AFTERNOON. * MIX OF LIGHT RAIN/LIGHT SNOW MID EVENING. * SNOW DEVELOPING LATE EVENING WITH A PERIOD OF HEAVY SNOW AFTER MIDNIGHT. * BLOWING SNOW OVERNIGHT INTO WEDNESDAY MORNING. * RAPIDLY DETERIORATING VIS/CIGS TO LIFR/VLIFR WITH SNOW. * STRONG/GUSTY NORTHERLY WINDS OVERNIGHT INTO WEDNESDAY MORNING WITH GUSTS 30-35 KTS POSSIBLE. CMS/RODRIGUEZ //DISCUSSION...UPDATED 12Z... LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE EAST ACROSS SOUTHERN ILLINOIS AND SOUTHERN INDIANA TONIGHT. LATEST 06Z GUIDANCE CONTINUES TO SHOW AXIS OF HEAVIEST SNOW MOVING ACROSS NORTH CENTRAL ILLINOIS DURING THE 06Z-12Z TIME PERIOD. WITH CONFIDENCE INCREASING FOR THIS SOLUTION...HAVE MOVED TEMPO LOWER CONDITIONS IN PREVIOUS FORECAST TO PREVAILING CONDITIONS FOR THE SAME TIME PERIOD WITH THE 12Z TAFS. POSSIBLE FOR VISIBILITIES TO DROP TO 1/4SM DURING THIS TIME WITH HEAVY SNOW WHICH COULD PRODUCE SNOWFALL RATES OF 1 TO 2 INCHES PER HOUR. THE BAND WILL SHIFT EAST TOWARD DAYBREAK WEDNESDAY...BUT LIGHT SNOW EXPECTED TO CONTINUE THROUGH MID MORNING WEDNESDAY. INITIALLY THE SNOW MAY MIX WITH RAIN AND BE RATHER WET BUT WILL BECOME DRIER AS COLDER AIR SPREADS IN FROM THE NORTH. AS THIS HAPPENS...BLOWING SNOW WILL DEVELOP AND WILL CONTINUE INTO WEDNESDAY MORNING. ALSO A SMALL POTENTIAL FOR A FEW LIGHTNING STRIKES/THUNDERSNOW BUT TOO ISOLATED OF A CHANCE TO INCLUDE IN THE FORECAST. THE GRADIENT WILL QUICKLY TIGHTEN FROM EARLY/MID EVENING THROUGH THE EARLY MORNING HOURS. NORTHERLY WINDS WILL LIKELY INCREASE INTO THE 20-25KT RANGE WITH GUSTS INTO THE 30-35KT RANGE OVERNIGHT INTO WEDNESDAY MORNING. WINDS WILL SLOWLY DIMINISH MID/LATE WEDNESDAY MORNING INTO WEDNESDAY AFTERNOON. IN THE SHORTER TERM...MID CLOUDS WILL CONTINUE TO LOWER THROUGH THE DAY. AN AREA OF LIGHT RAIN WILL MOVE ACROSS SOUTHERN WISCONSIN THIS AFTERNOON AND SLOWLY SAG INTO NORTHERN ILLINOIS TOWARD EVENING. PRECIPITATION AMOUNTS WILL BE LIGHT AND BULK OF THIS ACTIVITY SHOULD REMAIN NORTH OF THE TERMINALS...BUT DID INCLUDE VICINITY MENTION AT RFD FOR THIS AFTERNOON. LIGHT/CALM WINDS TO START WILL TURN NORTHEAST AND SLOWLY INCREASE THIS MORNING WITH GUSTS INTO THE 14-18KT RANGE MID/LATE AFTERNOON. LIGHT FOG THIS MORNING...MAINLY SOUTH OF THE TERMINALS WILL IMPROVE THROUGH MID/ LATE MORNING. CMS //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MEDIUM FOR LIGHT RAIN/LIGHT SNOW THIS EVENING. * HIGH FOR SNOW LATE THIS EVENING THROUGH WEDNESDAY MORNING... MEDIUM FOR TIMING AND SPECIFIC TRENDS. * HIGH FOR WINDS THROUGH THE PERIOD...MEDIUM ON TIMING/DIRECTIONS. * HIGH FOR VFR THROUGH EARLY EVENING...MEDIUM ON CIG/VIS TRENDS OVERNIGHT INTO WEDNESDAY MORNING. CMS/RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... * WEDNESDAY NIGHT...DRY/VFR. * THURSDAY...DRY/VFR. GUSTY SOUTHWEST WINDS. * FRIDAY...DRY/VFR. GUSTY WESTERLY WINDS. * SATURDAY...DRY/VFR. * SUNDAY...SLIGHT CHANCE OF SNOW. * MONDAY...DRY/VFR. && .MARINE... 330 AM...LOW PRESSURE CURRENTLY OVER THE WESTERN PLAINS WILL MOVE EAST TO SOUTHERN ILLINOIS LATE THIS EVENING AND THEN DEEPEN AS IT REACHES NEW ENGLAND WEDNESDAY NIGHT. THE GRADIENT WILL TIGHTEN AS THIS LOW PASSES SOUTH OF LAKE MICHIGAN WITH NORTHERLY WINDS STEADILY INCREASING FROM THIS AFTERNOON INTO EARLY WEDNESDAY MORNING. GALES APPEAR TO BEGIN LATE THIS EVENING AND INCREASE TO 45 KTS OVERNIGHT AND CONTINUE THROUGH MIDDAY WEDNESDAY...SLOWLY DIMINISHING WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING. OTHER THAN TWEAKING WIND SPEEDS/ GUSTS UP...NO SIGNIFICANT CHANGES TO GOING FORECAST/GRIDS OR HEADLINES. WINDS WILL QUICKLY DIMINISH WEDNESDAY NIGHT/EARLY THURSDAY MORNING AS A RIDGE OF HIGH PRESSURE MOVES ACROSS THE LAKE. WINDS THEN TURN SOUTHWESTERLY AND INCREASE TO 30 KTS AS LOW PRESSURE MOVES ACROSS ONTARIO THURSDAY NIGHT AND FRIDAY...WITH A TRAILING COLD FRONT FROM THIS LOW MOVING ACROSS THE WESTERN LAKES FRIDAY AFTERNOON INTO FRIDAY EVENING. VISIBLE SATELLITE IMAGERY FROM MONDAY SHOWS SOME OPEN WATER IN THE ILLINOIS NEARSHORE ZONES AND HAVE ACCOUNTED FOR THIS WITH WAVE HEIGHTS IN THIS MORNING/S FORECAST. HOWEVER...WITH THE EXPECTED STRONG NORTHERLY WINDS...ICE IN THE OPEN WATERS IS EXPECTED TO BE PUSHED BACK TO THE ILLINOIS SHORE TONIGHT. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WINTER STORM WARNING...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032...10 PM TUESDAY TO 1 PM WEDNESDAY. WINTER WEATHER ADVISORY...ILZ006-ILZ008-ILZ010-ILZ011- ILZ012...10 PM TUESDAY TO 10 AM WEDNESDAY. WINTER STORM WATCH...ILZ033-ILZ039...1 AM WEDNESDAY TO 1 PM WEDNESDAY. IN...WINTER STORM WARNING...INZ001-INZ002...10 PM TUESDAY TO 1 PM WEDNESDAY. WINTER STORM WATCH...INZ010-INZ011-INZ019...1 AM WEDNESDAY TO 1 PM WEDNESDAY. LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741- LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872- LMZ874-LMZ876-LMZ878...MIDNIGHT WEDNESDAY TO 9 PM WEDNESDAY. GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567- LMZ868...3 AM WEDNESDAY TO 4 PM WEDNESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS TOPEKA KS
ISSUED BY NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 326 PM CDT Tue Mar 11 2014 .SHORT TERM...(This Evening through Tonight) Issued at 322 PM CDT TUE MAR 11 2014 Late this afternoon, surface boundary bisects the CWA stretching just west of Wichita to the northeast to Topeka and further east north of KMCI. Several convergence zones ahead this boundary, with strongest axis stretching along the I-35/335 corridor. Will need to watch for potential development of convection along this corridor through 6pm as primary cold front moves east. Instability along and head of this front remains meager, with RAP analysis only indicating CAPE values 100-300 J/KG. If storms would happen to develop, the main impact would be small hail with the longevity of convection in the CWA minimal. The other concern heading into the overnight hours will be strong gradient winds. We`re already seeing advisory level winds in the far NW portion of the CWA at this hour, and as the surface boundary settles southeast, these strong gradient winds will swing through the CWA. By midnight, sfc pressure gradient should begin to weaken as the developing sfc low moves through the MO bootheel. The shortwave responsible for these strong winds and increasing precipitation chances is just beginning to enter the Western Plains this afternoon. A linear band of mid-level frontogenesis across NE/IA slopes back to western KS at 3pm. Short term model guidance continues to suggest that this band will slowly move southeast this evening. While the western flank of the mid-level lift should hold together the further southeast it tracks, the eastern areas of precip across NE/IA will dissipate as a new baroclinic zone is reestablished further south across eastern KS and northern Missouri. Precipitation should blossom shortly after 00Z along the eastern edges of the CWA. Given the position of the shortwave and how the wave pivots eastward, the majority of the heavy precipitation should take place just east of the CWA. Latest hopWRF, HRRR, RAP support the idea of a brief window of 3-5 hrs of a rain/snow mixture bisecting the CWA with most of the activity diminishing or moving east by 1am. Accumulations should remain light given the warm grounds, but could see up to an inch of snow in some spots where efficient rates can overtake boundary layer temps. .LONG TERM...(Wednesday Night through Tuesday) Issued at 322 PM CDT TUE MAR 11 2014 After the past two days, Wednesday will feel chilly with temperatures rebounding into the upper 40s to lower 50s. Will watch for an increase in low-level clouds late morning, as a secondary wave rotates southward into the area. A quick rebound above normal is expected by Thursday and Friday ahead of yet another shortwave pivoting through the southern Rockies. Temperatures on Thursday will rebound into the 60s, with a front dropping southward on Friday lowering readings a few degrees. Saturday-Monday: The aforementioned shortwave should pass far enough to the south Friday night to have minimal impact on the CWA leaving conditions pleasant for Saturday. A slightly more amplified flow pattern will drop colder air southward again on Sunday, but this cooldown should last no longer than a day as increasing southwesterly flow ushers above normal temperatures into the region to begin next week. Have bumped up temperatures for Monday. && .AVIATION...(For the 18Z TAFs through 18Z Wednesday Afternoon) Issued at 1222 PM CDT TUE MAR 11 2014 Frontal boundary remains just northwest of the Manhattan terminal this afternoon arching NE along the KS/NE state line. This boundary will continue to sink southeast and reach the Topeka area towards 22z. Winds will increase immediately behind this front with sustained winds between 25-30 knots an occasional gusts approaching 40 knots. There appears to be two areas of precipitation that will move through the region later this afternoon and tonight. Initial area of precipitation dropping southeast of out SW Nebraska associated with PV anomaly will gradually begin to merge with an intense area of frontogenesis focused just east of the CWA. Have timed initial development of rain around 00z, with a quick transition to rain/snow or even completely to snow by 03z. The progressive nature of the wave should force precipitation and associated MVFR to IFR ceilings/VIS through the terminals by 06z. After that point, we`ll see a gradual increase in ceilings, but winds will remain breezy through the night. && .TOP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY from 4 PM this afternoon to 1 AM CDT Wednesday FOR KSZ011-012-022>024-026-036>040-054>056-058-059. WIND ADVISORY until 10 PM CDT this evening FOR KSZ008>010-020- 021-034-035. && .TOP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY until 1 AM CDT Wednesday FOR KSZ011-012-022>024- 026-036>040-054>056-058-059. WIND ADVISORY until 10 PM CDT this evening FOR KSZ008>010-020- 021-034-035. && $$ SHORT TERM...DUX LONG TERM...DUX AVIATION...DUX
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
101 PM CDT Tue Mar 11 2014 ...Updated for aviation discussion... .SYNOPSIS... ISSUED AT 343 AM CDT TUE MAR 11 2014 Water vapor loop as of 08Z showed an impressive shortwave trough continuing to dig southeastward into Utah. RAP analysis had a 400mb potential vorticity (PV) anomaly extending from the base of the trough near Great Salt Lake northeastward into eastern Washington...suggesting a little more digging before the wave translates eastward. Warmest temperatures in the lower troposphere (850mb) were found across the High Plains of western Kansas into West Texas (+17C at both North Platte and Dodge City; +20C at Amarillo). The 08Z surface analysis showed a deepening surface low centered near the western Nebraska-Kansas state border. Surface winds continued to respond with overnight winds in the 10 to 13 knot range, helping keep temperatures from dropping much. It was still in the lower to mid 40s across much of the southwest and west central Kansas region. Surface cold frontogenesis was noted across northeastern Wyoming into the northern Nebraska Panhandle. && .SHORT TERM...(Today and tonight) ISSUED AT 343 AM CDT TUE MAR 11 2014 Moderate to high impact wind event this afternoon/evening is the main forecast challenge and how to handle this event with headlines (advisory vs. warning). Now that the forecast wind event is within higher resolution short-term models (RAP13, for instance) temporal range, we are gaining a bit higher confidence in the wind forecast. As the surface low moves southeast into central Kansas, it will continue to deepen down to about 995mb while surface anticyclogenesis will ramp up across the northern Rockies and adjacent High Plains. This will induce a very tight pressure gradient across western Kansas by midday...and especially this afternoon. The combined effect of the pressure gradient and the isallobaric wind due to pressure change, will likely lead to sustained winds around 40 mph for areas along and west of Highway 283 corridor...especially in the 22-01Z time frame. Forecast soundings off the NAM12 and RAP13 both show around 35 knots just off the surface around 900mb at Dodge City at 21Z with mixing up to 800-825mb. The winds around 800-850mb will pick up quite a bit as the north wind low level jet strengthens west of the low at this level. For Dodge City, the 00Z forecast soundings support a high wind event (40mph sustained and/or 58mph gusts) with 50 knots shown by both the NAM12 and RAP13 at the top of the mixed layer (which by that point will be due to vigorous cold advection). Based on this information, we will upgrade to a High Wind Warning for US283 corridor (Ness City down to Englewood) west to the Colorado border. Per collaboration with surrounding offices, we will also include areas of blowing dust where the High Wind Warning will be in effect and hit it pretty hard in the NPW product. As far as precipitation goes, the only area expected to see any measurable precipitation will be the I-70 corridor, and will carry around 50 POPs up there. A few tenths of an inch of wet snow may accumulate during the 23-02Z time frame in particular. .LONG TERM...(Wednesday through Monday) ISSUED AT 300 AM CDT TUE MAR 11 2014 Medium range models indicate an upper level shortwave breaking away from a larger scale trough Wednesday as it digs southeast across the Rockies, and developing into a closed off upper level low across the Intermountain West. Meanwhile, a general westerly flow aloft will prevail across the Western High Plains through the end of the week. This will result in dry conditions persisting across western Kansas through Thursday night with insufficient low/mid level moisture present. The closed off upper level low in the Desert Southwest is then expected to open up and push eastward into the South Plains early Friday bringing marginal precip chances to the Texas and Oklahoma panhandles based on the projected track of the shortwave. Cannot rule out a slight chance for light rain across extreme southern portions of southwest and south central Kansas Friday as the upper level system skirts across our southern fringe. Much cooler temperatures are likely Wednesday as arctic air spills southward into western Kansas in wake of a departing cold front. The NAM/GFS/ECMWF show H85 temperatures dropping well below 0C across central and western Kansas initially Tuesday night. A slight rebound to around 0C across central Kansas to near 5C along the Colorado border is expected Wednesday afternoon due to some northwesterly downsloping developing. Expect highs up into the upper 40s(F) to possibly the lower to mid 50s(F) under decreasing cloud cover. A quick bounce back to warmer temperatures will occur Thursday as the arctic high dips further south across Texas while lee side troughing redevelops across eastern Colorado. This will quickly return a southwesterly downslope flow to western Kansas pushing H85 temperatures up into the lower to mid Teens(C) across central and western Kansas. Highs will easily reach the 60s(F) Thursday afternoon with near 70F not out of the question in some locations. Another cold front is projected to push through western Kansas early Friday once again dropping temperatures across the area. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) ISSUED AT 1242 PM CDT TUE MAR 11 2014 A strong upper level system will pass across western Kansas this afternoon and evening. Strong north winds at 30-40kts will persist though 03z in the wake of surface low pressure, before subsiding. Blowing dust could restrict visbys to 4sm through 23z at GCK/DDC. Some light rain or snow is likely at KHYS between 23 and 04z as the upper level trough axis approaches, and this could restrict visibilities to MVFR. MVFR CIGS can be expected after 22-23z at HYS/GCK/DDC, before clearing develops after 4z in the wake of the upper level system. && .PRELIMINARY POINT TEMPS/POPS... DDC 59 28 53 26 / 20 20 0 0 GCK 57 27 52 24 / 20 20 0 0 EHA 59 28 50 28 / 10 10 0 0 LBL 62 27 52 25 / 10 10 0 0 HYS 48 28 52 24 / 60 60 0 0 P28 68 31 54 28 / 10 20 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING until 11 PM CDT /10 PM MDT/ this evening FOR KSZ043>045-061>064-074>078-084>088. WIND ADVISORY until 11 PM CDT this evening FOR KSZ046-065-066- 079>081-089-090. WIND ADVISORY until 11 PM CDT this evening FOR KSZ030-031. && $$ SYNOPSIS...Umscheid SHORT TERM...Umscheid LONG TERM...JJohnson AVIATION...Finch
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
110 PM EDT TUE MAR 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 509 AM EDT TUE MAR 11 2014 WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL FLOW FROM THE NRN PLAINS THROUGH THE NE CONUS. A SHORTWAVE TROUGH OVER NRN MANITOBA ON THE LEADING EDGE OF VERY COLD ARCTIC AIR IS EXPECTED TO SLIDE TO THE SE AS A RIDGE BUILDS INTO WRN CANADA. ANOTHER SHRTWV OVER SASK IS ALSO EXPECTED TO DIVE TOWARD THE UPPER MS VALLEY AS THE PATTERN AMPLIFIES. AT THE SFC...A COLD FRONT TRAILING LOW PRES OVER QUEBEC EXTENDED THROUGH NRN ONTARIO INTO SRN MANITOBA. TO THE SOUTH...MILD CONDITIONS PREVAILED WITH READINGS REMAINING IN THE UPPER 30S TO AROUND 40 FROM NRN MN AND NRN WI THROUGH UPPER MI. EXTENSIVE MID/HIGH CLOUDS HAVE ALSO LIMITED RADIATIONAL COOLING. TODAY...THE COLD FRONT IS EXPECTED TO MOVE THROUGH LAKE SUPERIOR AND UPPER MICHIGAN THIS MORNING BRINGING AN INITIAL INFLUX OF COLDER AIR. SO...MAX DAYTIME READINGS ARE EXPECTED EARLY WITH TEMPS STEADY OR SLOWLY FALLING DURING THE AFTERNOON. AS LOW LEVEL MOISTURE NORTH OF LAKE SUPERIOR MOVES IN AND 850 MB TEMPS FALL TO AROUND -13C BY 00Z/WED...SOME LIGHT SNOW SHOWERS OR FLURRIES MAY BE POSSIBLE LATE OVER THE NORTH AND WEST PORTIONS OF THE CWA. TONIGHT...AS THE SASK SHRTWV MOVES TOWARD THE AREA MUCH COLDER ARCTIC AIR WILL PUSH INTO THE REGION WITH 925 MB TEMPS DROPPING TO AROUND -21C AND INCREASING WINDS VEERING FROM THE FROM THE NNW TO NE. A PERIOD OF DEEPER MOISTURE ALONG WITH THE LOW LEVEL INSTABILITY WILL FAVOR SOME LES FOR LOCATIONS DOWNWIND OF LAKE SUPERIOR...ESPECIALLY WHERE UPSLOPE FLOW IS MAXIMIZED. THE POSITION OF THE DGZ WILL ALSO BE MOST FAVORABLE FROM 06Z-12Z/WED. SATELLITE IMAGERY FROM MON SHOWED ENOUGH BREAKS IN THE ICE COVER FOR AT LEAST SOME HEAT/MOISTURE FLUX FROM THE LAKE TO SUPPORT LES. SINCE THE ICE WILL STILL SIGNIFICANTLY REDUCE THE LES POTENTIAL...EXPECT SNOWFALL AMOUNTS ONLY IN THE 1 TO 2 INCH RANGE...GREATEST OVER THE HIGHER TERRAIN OF N CNTRL UPPER MI. THE NE WINDS WILL BE LESS FAVORABLE FOR SNOW AT IWD...WITH THE HIGHER CHANCES/AMOUNTS FARTHER TO THE WEST...OR FOR THE KEWEENAW WHERE LOW LEVEL CONV WILL BE MINIMAL. OTHERWISE...THE MUCH COLDER AIR WITH LOWS NEAR ZERO AND WINDS OF 10 TO 20 MPH WILL PRODUCE WIND CHILLS FROM -10 TO -20 LATE TONIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 343 AM EDT TUE MAR 11 2014 HIGH PRESSURE OVER NORTHWEST ONTARIO WILL LEAD TO NORTHEAST LOW LEVEL FLOW OVER THE UPPER GREAT LAKES REGION TO START THE LONG TERM PERIOD. THIS NORTHEAST FLOW WILL BE PRODUCING UPSLOPE SNOW SHOWERS ESPECIALLY IN NORTH CENTRAL UPPER MICHIGAN TONIGHT AND EXPECT THOSE TO CONTINUE INTO WEDNESDAY. ALTHOUGH WINDS HAVE CREATED SOME GAPS IN THE ICE NEAR THE SOUTHERN SHORELINE OF CENTRAL/EASTERN LAKE SUPERIOR...NOT THINKING THAT THERE WILL BE TOO MUCH ASSISTANCE TO THE UPSLOPE SNOW SHOWERS EVEN THOUGH 900MB TEMPS WILL BE AROUND -22C. WITH INVERSION HEIGHTS ONLY AROUND 3-4KFT...WOULDN/T EXPECT THE SNOW SHOWERS TO BE TOO STRONG AND ANY ADDITIONAL ACCUMULATIONS SHOULD BE LIGHT WITH THE CLOUD BEING ABOVE THE DGZ. DID SLOWLY DIMINISH THE SNOW SHOWER CHANCES THROUGH THE DAY AS THE MOISTURE DEPTH BECOMES SHALLOW AND WINDS BACK TO THE NORTH-NORTHWEST. WITH THE MODELS SHOWING THE MOISTURE REMAINING BELOW THE STRENGTHENING INVERSION FROM THE HIGH MOVING OVER THE UPPER GREAT LAKES...WONDERING IF CLOUDS WILL HOLD OVER THE AREA INTO THE AFTERNOON (ESPECIALLY OVER THE NORTH CENTRAL). THE NORTHERLY WINDS AND CLOUDS WILL LEAD TO A VERY COLD DAY ACROSS UPPER MICHIGAN...WITH HIGHS IN THE UPPER SINGLE DIGITS TO MID TEENS. STILL LOOKS TO BE A VERY COLD NIGHT ON WEDNESDAY NIGHT AS THE HIGH SHIFTS SOUTHEAST ACROSS THE CWA. WILL CONTINUE TO SHOW THE COLDEST VALUES OF -10F TO -18F OVER THE EAST HALF OF THE CWA AND THE SINGLE DIGITS BELOW ZERO OVER THE WEST HALF. WOULD EXPECT THE TEMPERATURES TO WARM OVER THE WEST TOWARDS MORNING AS RETURN FLOW DEVELOPS AND MID CLOUDS BEGINNING TO MOVE IN UNDER WAA AHEAD OF THE NEXT CLIPPER SYSTEM. GEM/ECMWF/NAM CONSISTENT ON SOME LIGHT PRECIPITATION MOVING INTO THE WESTERN U.P. WITH THIS WAA ON THURSDAY MORNING. SINCE THERE HAVE BEEN INDICATIONS OF THIS OVER THE LAST COUPLE OF DAYS...WILL TREND VALUES UP TO CHANCES AND THEN DIMINISH THEM AS THEY HEAD EAST OVER THE REST OF THE CWA DURING THE AFTERNOON. WHILE EARLIER RUNS WERE INDICATING A LACK OF ICE CRYSTALS FOR THIS PRECIPITATION...IT NOW APPEARS THAT THERE WILL BE ENOUGH MOISTURE IN THE ICE CRYSTAL AREA TO SUPPORT ALL SNOW. AT THIS POINT...MIGHT SEE UP TO A HALF INCH TOWARDS IRONWOOD AND THEN DIMINISHING AMOUNTS HEADING EAST. BEHIND THIS PRECIPITATION...FOCUS TURNS TO THE LOW CENTERED NEAR LAKE WINNIPEG AT 18Z THURSDAY. THIS LOW WILL TRACK SOUTHEAST THROUGH THE UPPER GREAT LAKES REGION LATE THURSDAY NIGHT INTO FRIDAY. MODELS STILL DIFFERING ON THE SHORTWAVE...WHICH IS NOW WELL OVER THE PACIFIC...WHICH IN-TURN CONTROLS THE TRACK OF THE LOW. GFS HAS CONSISTENTLY BEEN THE FARTHEST NORTH (ALONG WITH RECENT RUNS OF THE UKMET) AND RUNNING THE LOW ALONG THE NORTH SHORE OF LAKE SUPERIOR...WHILE THE ECMWF TRACKS THE LOW ALONG THE SOUTH SHORE. THE GEM HAS BEEN BOUNCING BETWEEN THE TWO OVER THE LAST COUPLE DAYS. ALL IN ALL...THESE DIFFERENCES WON/T HAVE TOO MUCH OF AN AFFECT ON THE LAND CWA PRECIPITATION...SINCE THE WAA PRECIP WILL BE OVER NORTHEAST LAKE SUPERIOR AND ONTARIO THURSDAY NIGHT. UNFORTUNATELY FOR THOSE LOOKING FOR ANOTHER REALLY WARM DAY...IT APPEARS THAT THE WARM AIR ALOFT WILL MOVE THROUGH ON THURSDAY NIGHT AND THEN AREA WILL SEE COLDER AIR MOVING IN THROUGH THE DAY. THUS...EXPECT THE WARMEST TEMPS ON FRIDAY TO BE NEAR LAKE MICHIGAN AND IN THE UPPER 30S TO AROUND 40. WITH THE DIFFERENCES IN THE TRACK OF THE LOW...THERE ARE ALSO DIFFERENCES IN THE ARRIVAL OF THE SECONDARY COLD FRONT AND NORTHERLY WINDS. COULD BE A LITTLE BREEZY OUT OF THE WEST ON FRIDAY BEFORE THIS ARRIVES...WITH WINDS TURNING TO THE NORTHWEST AND EVENTUALLY NORTHERLY ON FRIDAY NIGHT. EXPECT SOME PRECIPITATION ASSOCIATED WITH THIS COLD SURGE AND WITH SOME GAPS STARTING TO SHOW IN THE ICE NEAR THE APOSTLE ISLANDS...THERE COULD EVEN BE SOME LAKE ENHANCED/EFFECT SNOW FRIDAY NIGHT INTO SATURDAY. DIFFICULT TO GO WITH MUCH MORE THAN SLIGHT/CHANCE POPS WITH THE AMOUNT OF ICE COVER AND POTENTIAL CHANGES OVER THE NEXT SEVERAL DAYS...SO WILL FOLLOW A SIMILAR IDEA AS THE PREVIOUS SHIFT. THAT PUTS CHANCES OVER THE FAVORED NORTHWEST AREAS IN THE WEST ON FRIDAY NIGHT AND THEN TRANSITION TO TRADITIONAL NORTHWEST-NORTHERLY WIND AREAS FOR SATURDAY. WITH A HIGH PRESSURE RIDGE NOSING SOUTH FROM ONTARIO ON SATURDAY NIGHT AND SUNDAY...EXPECT DRIER AIR TO MOVE IN AND HAVE DIMINISHED POPS HEADING INTO SUNDAY (EVENTHOUGH 850MB TEMPS REMAIN AROUND -17C). WITH THE COLD TEMPS ALOFT...SHOULD BE 10-20 DEGREES BELOW NORMAL FOR HIGHS THIS WEEKEND. DEPENDING ON HOW QUICKLY SKIES CLEAR OUT ON SATURDAY NIGHT...THERE IS THE POTENTIAL FOR SUB ZERO LOWS OVER MUCH OF THE AREA AND HAVE TRENDED VALUES DOWN A COUPLE DEGREES. THE COLDEST NIGHT WILL BE SUNDAY NIGHT AS THE AREA OF HIGH PRESSURE MOVES OVER THE CWA. SINGLE DIGITS BELOW ZERO SEEMS LIKE A GOOD START AT THIS POINT...BUT WOULDN/T BE SURPRISED TO SEE SOME COLD SPOTS IN THE TEENS BELOW ZERO. THE HIGH IS EXPECTED TO SHIFT EAST ON MONDAY...BUT IT/S INFLUENCE WILL REMAIN AND KEEP THE AREA DRY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 110 PM EDT TUE MAR 11 2014 THE RETURN OF COLD AND MOIST LOW LEVEL AIR AIDED BY SOME DAYTIME HEATING/DESTABILIZATION WILL CONTINUE THE MVFR STRATOCU DECK AT ALL 3 LOCATIONS THROUGH WEDNESDAY MORNING. THE APPROACH OF A DISTURBANCE EMBEDDED IN THE NW FLOW ALOFT THIS EVNG WILL BRING SOME SHSN TO THE AREA. THE COMBINATION OF VERY COLD AIR OVER EVEN LIMITED GAPS IN THE LAKE SUPERIOR ICE COVER AND UPSLOPE INTO SAW SHOULD PRODUCE SOME -SHSN. DRIER AIR STARTS TO COME IN BY LATE WED MORNING AND SHOULD SCATTER OUT THE CLOUDS AT IWD AND CMX AND PUT THEM BOTH INTO VFR LATE WED MORNING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 509 AM EDT TUE MAR 11 2014 A COLD FRONT WILL MOVE THROUGH THE AREA TODAY WITH NW TO N WINDS INCREASING TO 20 TO 30 KNOTS OVER ERN LAKE SUPERIOR THIS AFTERNOON INTO TONIGHT. WINDS WILL DIMINISH WED INTO WED NIGHT AS HIGH PRES BUILDS OVER THE NRN LAKES. WINDS WILL REMAIN AT OR BELOW 20 KNOTS UNTIL FRIDAY WHEN ANOTHER LOW PRES SYSTEM JUST TO THE NORTH OF LAKE SUPERIOR BRINGS WEST AND NORTHWEST WINDS OF 20 TO 30 KNOTS AS IT MOVES THROUGH THE REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
320 PM CDT TUE MAR 11 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY AFTERNOON) ISSUED AT 315 PM CDT TUE MAR 11 2014 MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND SKY COVER AND SUBSEQUENT LAKE EFFECT SNOW SHOWERS ALONG THE SOUTH SHORE FROM DULUTH TO ASHLAND TO MONTREAL TONIGHT...ALONG WITH FALLING TEMPERATURES ACROSS THE NRN COUNTIES UNDER MOSTLY CLEAR SKIES EARLY WED MORNING. WEAK SFC COLD FRONT CONTINUES TO SLIDE TO THE SOUTH ACROSS NRN MN AS HIGH PRESSURE BUILDS IN NORTH OF THE FRONT OVER CENTRAL MANITOBA AND WRN ONTARIO. A TIGHT SFC PRES GRADIENT HAS DEVELOPED OVER THE REGION WHICH HAS ALLOWED W/NW WINDS TO INCREASE AND BECOME GUSTY THIS AFTERNOON. AREA OBSERVATIONS HAVE INDICATED SUSTAINED WINDS AROUND 10 TO 15 MPH AND GUSTS 20 TO 25 MPH. THE AIR MASS IS FAIRLY DRY OVER THE NORTHLAND AND MOST OF THE MID AND HIGH LEVEL CLOUDS FROM THIS MORNING HAVE DISSIPATED THIS AFTERNOON. AN AREA OF MID LEVEL STRATO-CU HAS DEVELOPED OVER THE ARROWHEAD...BUT SHOULD MIX OUT BY THE EVENING. THE SFC HIGH TO THE NORTH WILL SHIFT TO THE SOUTH AND SE TONIGHT AND BECOME POSITIONED JUST NORTH OF THE ARROWHEAD IN WRN ONTARIO WHICH WILL COMBINE WITH A STRENGTHENING AREA OF LOW PRESSURE OVER THE SRN GREAT LAKES REGION TO PRODUCE A MODEST NE WIND OVER WRN LAKE SUPERIOR. THE COLD AIR ASSOCIATED WITH THE HIGH WILL ADVECT OVER THE RELATIVELY WARMER LAKE AND PRODUCE SCATTERED LAKE EFFECT SNOW SHOWERS FROM THE TWIN PORTS TO THE GOGEBIC RANGE DURING THE LATE EVENING AND OVERNIGHT HOURS. 850MB TEMPS WILL BE ROUGHLY -19 TO -22 DEG C...WITH LAKE TEMPS AROUND 1 TO 2 DEG C. THIS SHOULD ALLOW BL LAPSE RATES TO SUPPORT LES. HOWEVER...THE DEPTH OF THE LAYER MIGHT BE AN INHIBITING FACTOR WITH BDY LAYER HEIGHTS AROUND 4K FT. RECENT WARMING AND STRONG WINDS HAVE ALLOWED MUCH OF THE LAKE TO LOSE ITS SOLID ICE COVER...SO WITH MUCH OF WRN LAKE SUPERIOR OPEN...CONDITIONS ARE NOW SLIGHTLY MORE FAVORABLE AS WELL. THE CHANCE FOR LES WILL BE FLEETING AS DRIER AIR MOVES IN BY MID-LATE WED MORNING. SNOW AMTS WILL GENERALLY BE A HALF INCH OR LESS...WITH SOME LOCATIONS AROUND OR JUST ABOVE AN INCH FROM DOUGLAS TO IRON COUNTY. TEMPERATURES WILL DROP FAIRLY RAPIDLY TONIGHT UNDER AREAS THAT SEE MOSTLY CLEAR SKIES. THE BEST CHANCE FOR SUSTAINED SIGNIFICANT CLEARING WILL CONTINUE TO BE ACROSS THE NORTH AND OVER THE WRN COUNTIES. AREAS TO THE EAST AND SE WILL BE UNDER THE INFLUENCE OF LE CLOUDS. THE COLDEST AIR WILL BE ACROSS THE NORTH WHERE TEMPS WILL DIP INTO THE SINGLE DIGITS AND TEENS BELOW ZERO. LIGHT NW WINDS WILL PRODUCE WIND CHILL VALUES AROUND -15 TO -20. TEMPERATURES WILL HAVE A DIFFICULT TIME WARMING DURING THE DAY TOMORROW WITH THE COLD AIR MASS IN PLACE. HOWEVER...A WAA PATTERN WILL DEVELOP FROM WEST TO EAST GOING INTO THE LATE AFTERNOON PERIOD. LOOK FOR HIGHS TOMORROW TO TOP OUT IN THE UPPER TEENS AND LOWER TO MID 20S. SHOULD SEE SKIES CLEAR OFF EARLY WED AFTERNOON BEFORE ANOTHER MID-HIGH DECK OF CLOUDS MOVES IN FROM THE WEST BY THE LATE AFTERNOON PERIOD. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 315 PM CDT TUE MAR 11 2014 SEVERAL SHORTWAVES WILL IMPACT THE NORTHLAND THROUGH THE EXTENDED PERIOD BRINGING CHANCES FOR LIGHT SNOW...BUT NO SIGNIFICANT SNOWFALL IS EXPECTED AT THIS TIME. A PERIOD OF STRONG WAA WILL OCCUR WEDNESDAY NIGHT AND BRING A CHANCE FOR MAINLY LIGHT SNOW FROM WEST TO EAST ACROSS THE NORTHLAND. THE NAM IS MOST BULLISH WITH PRECIPITATION AMOUNTS AND WE LEANED TOWARD IT AND INCREASED POPS/SNOW AMOUNTS. IT LOOKS LIKE A HALF TO AROUND ONE INCH OF SNOW WILL OCCUR WITH THE WAA. SOUNDINGS LOOK SUPPORTIVE FOR FREEZING DRIZZLE AS WELL...BUT THE BETTER LIFT WILL BE WITH THE INITIAL SURGE OF WAA AND WE DO NOT EXPECT MUCH TO OCCUR AFTER THE MAIN AREA OF PRECIPITATION MOVES THROUGH. THURSDAY LOOKS TO BE MILD AND WE KEPT HIGHS IN THE FORTIES...WHICH IS ON THE HIGH END OF MOST GUIDANCE. RECENT MODEL GUIDANCE HAS BEEN TOO COOL OVER THE PAST COUPLE DAYS WHEN TEMPS HAVE BEEN MILD. A LOW WILL MOVE ACROSS FAR NORTHERN MINNESOTA OVER EASTERN LAKE SUPERIOR THURSDAY NIGHT...USHERING IN COOLER AIR. THERE WILL BE A CHANCE FOR LIGHT SNOW WITH THIS FEATURE...BUT AMOUNTS WILL BE LIGHT THURSDAY NIGHT INTO FRIDAY. HIGHS FRIDAY WILL RANGE FROM THE MID THIRTIES TO LOWER FORTIES. THERE WILL BE A CHANCE FOR SOME LAKE EFFECT SNOW SATURDAY...AND DEPENDING ON THE EXTENT OF OPEN WATER...SOME MEASURABLE SNOW IS LOOKING MORE LIKELY ALONG THE SOUTH SHORE. COOLER HIGHS IN THE TWENTIES ARE EXPECTED SATURDAY/SUNDAY. THE ECMWF CONTINUES TO WAFFLE FROM RUN TO RUN SUNDAY NIGHT WITH AN AREA OF LOW PRESSURE. IT HAS GONE BACK TO BRINGING A CHANCE FOR SNOW TO OUR SOUTHERN CWA...BUT WE KEPT THE FORECAST DRY UNTIL BETTER CONTINUITY OCCURS. THERE WILL BE A CHANCE FOR SNOW EARLY NEXT WEEK AS ANOTHER SHORTWAVE MOVES THROUGH THE REGION. HIGHS MONDAY WILL BE IN THE MID TWENTIES TO LOWER THIRTIES...WITH LOWER TO MID THIRTIES TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1244 PM CDT TUE MAR 11 2014 COLD AIR ADVECTION WILL OCCUR TODAY/TONIGHT WITH A SHORTWAVE MOVING THROUGH AS WELL TONIGHT. STRATOCU HAS DEVELOPED OVER FAR NORTHERN MINNESOTA/NORTHWEST ONTARIO. WE EXPECT SCATTERED TO BROKEN CLOUDS FROM 2500-3500 TO MOVE INTO MOST TAF SITES THIS AFTERNOON INTO TONIGHT...WITH A FEW PERIODS OF LIGHT SNOW OR FLURRIES. THE RAP HAS DONE AN OK JOB DEPICTING THE CLOUDS...BUT DOES SEEM TO BE OVERDOING THE COVERAGE. THE LOWER CLOUDS WILL DISSIPATE FROM NORTH TO SOUTH LATER TONIGHT INTO WEDNESDAY MORNING. GUSTY NORTH-NORTHWEST WINDS WILL OCCUR THIS AFTERNOON...THEN WILL DIMINISH TONIGHT. WINDS WILL VEER TO EAST-NORTHEAST. THERE IS MORE OPEN WATER OVER LAKE SUPERIOR PER MODIS IMAGERY...AND THAT SHOULD ALLOW MORE LAKE CLOUDS/SNOW TO DEVELOP TONIGHT WITH THE COLD AIR MOVING IN. AS WINDS TURN MORE EASTERLY LATE TONIGHT...A BETTER CHANCE FOR SOME LES/CLOUDS WILL OCCUR IN KDLH. && .PRELIMINARY POINT TEMPS/POPS... DLH 4 20 9 43 / 30 10 60 10 INL -8 19 12 44 / 10 10 60 10 BRD 7 23 15 47 / 10 10 50 0 HYR 3 19 6 44 / 20 10 50 10 ASX 3 13 4 46 / 40 20 50 20 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...BJT LONG TERM...MELDE AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1246 PM CDT TUE MAR 11 2014 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 345 AM CDT TUE MAR 11 2014 AT 345AM/0845Z...THERE WAS A LOW PRESSURE SYSTEM IN THE CENTRAL/SOUTHERN PLAINS. ITS ASSOCIATED BAND OF PCPN NORTH OF THE LOW...STRETCHING FROM WEST TO EAST...WAS MOVING THROUGH SOUTH DAKOTA. MUCH OF THE UPPER MIDWEST AND NORTHERN PLAINS HAD BKN/OVC CLOUD COVER...MOSTLY FROM MID/HIGH CLOUDS. ANOTHER LOW PRESSURE SYSTEM WAS OVER WESTERN QUEBEC. A COLD FRONT EXTENDED WESTWARD FROM THE QUEBEC LOW TO SOUTHERN MANITOBA AND SASKATCHEWAN. THERE WAS CONSIDERABLY COLDER AIR...AIR OF ARCTIC ORIGINS...BEHIND THE COLD FRONT. MUCH OF ONTARIO...MANITOBA...AND SASKATCHEWAN HAD BKN/OVC LOW LEVEL CLOUD COVER. THE NORTHLAND HAD TEMPERATURES RANGING FROM THE UPPER 30S ACROSS THE SOUTHERN FORECAST AREA TO THE UPPER 20S ACROSS THE NORTHERN FORECAST AREA. THERE WERE WNW TO NW WINDS OF ABOUT 5 TO 10 MPH. TODAY...THE PLAINS LOW PRESSURE SYSTEM WILL SHIFT EAST TO MISSOURI. ITS BAND OF PCPN IS EXPECTED TO REMAIN JUST SOUTH OF THE FORECAST AREA. THE ASSOCIATED MID/HIGH CLOUDS SHOULD CONTINUE TO COVER MUCH OF THE FORECAST AREA THROUGH THIS MORNING...BUT THEN BEGIN TO SCATTER AND SHIFT SOUTH THIS AFTERNOON. WHILE WE WILL LIKELY BEGIN TO DITCH THE MID/HIGH CLOUDS....THE LOW CLOUDS IN CANADA WILL LIKELY SPREAD BEGIN TO SPREAD INTO THE FORECAST AREA LATE THIS MORNING AND THIS AFTERNOON AS THE CANADIAN COLD FRONT MOVES GRADUALLY MOVES SOUTH THROUGH THE FORECAST AREA. THERE COULD BE SOME SNOW FLURRIES THIS AFTERNOON...AT LEAST ACROSS THE NORTHERN FORECAST AREA. THE LATEST MODEL GUIDANCE SUGGESTED WARMER TEMPERATURES FOR THE SOUTHERN FORECAST AREA...SO I INCREASED THE HIGH TEMPERATURES TODAY SINCE THOSE MODELS ARE IN DECENT AGREEMENT. THE HIGHS WILL BE SLIGHTLY BELOW NORMAL TODAY. TONIGHT...THE ARCTIC AIR WILL CONTINUE TO POUR INTO THE NORTHLAND. THE NORTHERLY WINDS OVER WESTERN LAKE SUPERIOR WILL STRENGTHEN AND BECOME NNE TO ENE. CONSIDERING THAT THERE IS A LOT MORE OPEN WATER NOW DUE TO THE RECENT WARM WEATHER...THE COLD FLOW OVER THE LAKE WILL RESULT IN SOME DECENT CHANCES FOR LAKE EFFECT SNOW. I INCREASED THE PCPN CHANCES ACROSS NW WISCONSIN...THE TWIN PORTS AREA...AND FOR THE ST. CROIX RIVER VALLEY AREA. MOST OF THE MODELS DO NOT APPEAR TO BE PICKING UP ON THE LAKE EFFECT SNOW THREAT...BUT THE NAM12 AND SREF ARE DOING MUCH BETTER HANDLING THIS. SOME AREAS WILL LIKELY GET ABOUT A HALF TO A FULL INCH. MORE IS POSSIBLE...BUT I THINK WE WILL GET A BETTER IDEA OF THE THREAT WHEN THIS TIMEFRAME COMES INTO VIEW FOR MORE OF THE HIGH RESOLUTION MODELS. THE BEST PERIOD OF LAKE EFFECT SNOW APPEARS TO BE FROM ABOUT 9 PM TO 3 AM. THIS IS WHEN OVERALL MOISTURE IN THE FLOW OVER THE LAKE LOOKS TO BE BEST...AND THEN DRIER AIR WILL BEGIN TO MOVE INTO THE REGION VERY LATE TONIGHT. HIGH PRESSURE WILL BEGIN TO MOVE OUT OF CANADA AND INTO NORTHERN MINNESOTA AFTER MIDNIGHT. THE MODELS ARE IN PRETTY GOOD AGREEMENT THAT THERE WILL BE CLEARING ACROSS THE WESTERN AND NORTHERN FORECAST AREA...AND DECREASING WINDS. THIS WILL LIKELY ALLOW TEMPERATURES TO QUICKLY FALL AROUND AND SHORTLY BEFORE DAWN WEDNESDAY...ESPECIALLY ACROSS FAR NORTHERN MINNESOTA. I DECREASED THE OVERNIGHT LOW TEMPERATURES. THE FORECAST NOW HAS A RANGE OF MID TO UPPER SINGLE DIGITS ACROSS THE SOUTHERN FORECAST AREA...TO THE MID TO UPPER SINGLE DIGITS BELOW ZERO ACROSS THE NORTHERN FORECAST AREA. WEDNESDAY...THE HIGH PRESSURE WILL MOVE THROUGH THE REGION. THIS WILL CUT OFF THE THREAT OF LAKE EFFECT SNOW AS THE WINDS OVER WESTERN LAKE SUPERIOR LIGHTEN. MUCH OF THE FORECAST AREA WILL LIKELY SEE PLENTY OF SUNSHINE DURING THE MIDDLE OF THE DAY. THIS WILL HELP BOLSTER THE TEMPERATURES...BUT I DID LOWER THE HIGHS A BIT BASED ON THE LATEST MODELS BEING MUCH COLDER THAN THE PREVIOUS FORECAST. A STRONG WARM FRONT WILL MOVE INTO THE NORTHERN PLAINS AND SOUTH CENTRAL CANADA WEDNESDAY...BRINGING WITH IT WARM AND MORE MOIST AIR OF PACIFIC ORIGINS. THERE COULD BE SOME LIGHT PCPN THAT DEVELOPS ACROSS THE WESTERN FORECAST BY THE LATE AFTERNOON...BUT SINCE ONLY THE GFS WAS THIS QUICK AT BRINGING IN THE PCPN...I DECIDED TO KEEP THE AFTERNOON FORECAST DRY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 345 AM CDT TUE MAR 11 2014 HAVE INCREASED TO BROADBRUSH HIGH CHANCE POPS WED NIGHT/THURS MORNING AS A WARM FRONT/MID LEVEL OMEGA TRANSLATES EAST ACROSS THE NORTHLAND...TRIGGERING A BRIEF WINDOW OF LIGHT SNOW SHOWERS. ACCUMULATIONS WILL BE MINIMAL...GENERALLY A HALF TO ONE INCH. THERE WILL BE A BRIEF BREAK IN THE PRECIPITATION THURSDAY AS THE WARM SECTOR PUSHES ACROSS THE FORECAST AREA...ALLOWING FOR TEMPS TO WARM WELL INTO THE 40S AND POSSIBLY SOME 50S. LATEST MODELS SHOW SLIGHT DIFFERENCES IN TRACK AND TIMING...BUT ARE IN OVERALL GOOD AGREEMENT THAT A SHORT WAVE WITH CLOSED H85/SFC LOW DROPS OUT OF CANADA AND TRACKS ACROSS THE WESTERN GREAT LAKES REGION THURS NIGHT/FRIDAY. AT THIS TIME...MODELS SUGGEST THERE IS A LACK OF MOISTURE ACCOMPANYING THE ASSOCIATED COLD FRONT PASSAGE...WITH THE BEST CHANCE FOR AN INCH OR TWO OF SNOW NEAR THE LOW CENTER ALONG THE INTERNATIONAL BORDER/MN ARROWHEAD ZONES. HOWEVER...INSTABILITY SNOW SHOWERS WILL BE COMMON IN THE COLD AIR MASS BEHIND THE DEPARTING SYSTEM FRIDAY/FRIDAY NIGHT. LONG RANGE MODELS ARE IN GOOD AGREEMENT THAT AN AREA OF CANADIAN HIGH PRESSURE BUILDS INTO THE REGION SATURDAY...SETTLING OVER THE WESTERN GREAT LAKES SUNDAY. AS THE HIGH DEPARTS TO THE EAST MONDAY...IT WILL BE REPLACED BY UPPER LEVEL RIDGING AND A WARM SOUTHERLY FLOW FOUND AHEAD OF AN DEEPENING LOW PRESSURE SYSTEM IN THE DAKOTAS. ALTHOUGH THERE ARE SIGNIFICANT DIFFERENCES IN STRENGTH AND TRACK OF THE LOW...THERE IS AGREEMENT THAT THIS ORGANIZED SYSTEM DIGS ACROSS THE UPPER PLAINS AND TRACKS OVER THE NORTHLAND DURING THE FIRST HALF OF NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1244 PM CDT TUE MAR 11 2014 COLD AIR ADVECTION WILL OCCUR TODAY/TONIGHT WITH A SHORTWAVE MOVING THROUGH AS WELL TONIGHT. STRATOCU HAS DEVELOPED OVER FAR NORTHERN MINNESOTA/NORTHWEST ONTARIO. WE EXPECT SCATTERED TO BROKEN CLOUDS FROM 2500-3500 TO MOVE INTO MOST TAF SITES THIS AFTERNOON INTO TONIGHT...WITH A FEW PERIODS OF LIGHT SNOW OR FLURRIES. THE RAP HAS DONE AN OK JOB DEPICTING THE CLOUDS...BUT DOES SEEM TO BE OVERDOING THE COVERAGE. THE LOWER CLOUDS WILL DISSIPATE FROM NORTH TO SOUTH LATER TONIGHT INTO WEDNESDAY MORNING. GUSTY NORTH-NORTHWEST WINDS WILL OCCUR THIS AFTERNOON...THEN WILL DIMINISH TONIGHT. WINDS WILL VEER TO EAST-NORTHEAST. THERE IS MORE OPEN WATER OVER LAKE SUPERIOR PER MODIS IMAGERY...AND THAT SHOULD ALLOW MORE LAKE CLOUDS/SNOW TO DEVELOP TONIGHT WITH THE COLD AIR MOVING IN. AS WINDS TURN MORE EASTERLY LATE TONIGHT...A BETTER CHANCE FOR SOME LES/CLOUDS WILL OCCUR IN KDLH. && .PRELIMINARY POINT TEMPS/POPS... DLH 34 4 19 10 / 10 30 10 50 INL 27 -9 19 15 / 20 10 0 50 BRD 36 7 23 15 / 10 10 10 40 HYR 36 3 17 8 / 10 20 10 40 ASX 37 3 13 4 / 10 30 20 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...GROCHOCINSKI LONG TERM...GRANING AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1204 PM CDT TUE MAR 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CDT TUE MAR 11 2014 MOST SIGNIFICANT PRECIPITATION OVER THE NEXT 7 DAYS WILL FALL WITHIN THE NEXT 12 HRS OF THIS DISCUSSION AS AN IMPRESSIVE FRONTGENETICALLY DRIVEN BAND OF PRECIP BLOSSOMS ACROSS THE SOUTHERN HALF OF THE CWA THIS MORNING. HIRES MODELS CONTINUE TO BE TOO COOL WITH THE LOW LEVEL THERMAL FIELDS...AND THUS THEIR PTYPE ALGORITHMS ARE LIKELY OVERDOING THE SNOWFALL ACROSS THE REGION DURING THE INITIAL DEVELOPMENT EARLY THIS MORNING. HOWEVER...BUFR FORECAST SOUNDINGS SHOW TREMENDOUS LIFT ALONG THE LOW/MID LEVEL FRONT AS INFERRED FROM THE SHARP WIND SHIFT WITHIN THE H850-700 LAYER. ASIDE FROM THE LOWEST FEW HUNDRED METERS THE ENTIRE SOUNDING IS BELOW FREEZING...SO ANTICIPATING THAT THE RAIN WILL CHANGE OVER TO A RAIN SNOW MIX AROUND 6-7AM...AND THEN QUICKLY OVER TO HEAVY WET SNOW AROUND MID MORNING ACROSS SOUTHERN MN. SNOW RATIOS WILL BE IN THE MID-SINGLE DIGITS...BUT QPF SHOULD EASILY MANAGE AROUND 0.20 TO 0.30 YIELDING SNOWFALL TOTALS OF 1-2 INCHES UNDER THE HEAVIEST BAND OF SNOW. AT THIS POINT THE RAP 11.07 PLACES THIS HEAVY BAND FROM CANBY MN EASTWARD THROUGH THE SOUTHERN METRO...AND THEREFORE ALL THE HIRES MODELS THAT USE THE RAP FOR THEIR INITIAL BOUNDARY CONDITIONS ARE SUBCONSCIOUSLY DRAWN TO THIS CONCLUSION. HOWEVER...THE H850-700MB FGEN...WHICH AS OF EARLY THIS MORNING MATCHES UP NICELY WITH THE ONGOING PRECIP...SHIFTS SOUTHEAST FROM CANBY TO MANKATO AND OWATONNA. BASED ON THAT DIAGNOSTIC TOOL...EXPECT THE PRECIP TO FALL TOWARD THE SOUTHERN SIDE OF THE CURRENT MODEL GENERATED QPF FIELD. AT THIS POINT NOT ANTICIPATING ANY ADVISORY CRITERIA SNOWFALL AMOUNTS...BUT EXPECT HEAVY WET SNOW WITH 1/2 TO 1/4 MI VISIBILITY POSSIBLE AT TIMES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 345 AM CDT TUE MAR 11 2014 LOOKING AHEAD...COLD AIR WILL SURGE SOUTHWARD BEHIND THIS SYSTEM AS IT STRENGTHENS INTO A MAJOR STORM OVER NEW ENGLAND. CLOSER TO HOME TEMPERATURES WILL FALL BELOW FREEZING TONIGHT AND REMAIN THERE UNTIL THURSDAY WHEN THE NEXT SHOT OF LEE-SIDE WARM AIR SPREADS ACROSS THE REGION. THIS WILL BRING TEMPERATURES INTO THE 40S ONCE AGAIN...WITH 50S IN WESTERN MN. THERE IS A CHANCE FOR SOME LIGHT PRECIP AHEAD OF THIS WARM AIR ADVECTION...MAINLY ALONG THE ST CROIX RIVER VALLEY. THIS WARMUP WILL BE SHORT LIVED AS COLD AIR SPREADS SOUTHWARD AND LASTS INTO NEXT WEEK. NO SIGNIFICANT PRECIPITATION IS EXPECTED UNTIL THE NEXT STORM SYSTEM ARRIVES ON TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1155 AM CDT TUE MAR 11 2014 RAIN/SNOW HAS SHIFTED SOUTH OF THE TAF SITES FOR THE REMAINDER OF THE PERIOD. VFR CONDITIONS EXPECTED THROUGH THE AFTERNOON...WITH PERHAPS SOME LOWER CIGS DEVELOPING THIS EVENING AS THE UPPER TROUGH SWINGS SOUTHEAST. MENTIONED SOME MVFR CIGS DEVELOPING INTO WEST CENTRAL WISCONSIN IN THE 03Z-04Z PERIOD. THIS MAY BE A BIT FAST BUT MODELS ARE SUGGESTING DEVELOPMENT INTO THE EVENING. WILL KEEP THE VFR CIGS FARTHER TO THE WEST INTO MINNESOTA...BUT CONFIDENCE IS NOT THAT HIGH...ESPECIALLY TOWARD KSTC/KMSP. DETERMINISTIC MODELS CONTINUE TO SUGGEST INVERTED TROUGH DEVELOPMENT ALONG THE MN/WI BORDER AREA. WILL HAVE TO MONITOR HOW AR WEST THIS OCCUR. OTHERWISE...MAINLY MID/HIGH LEVEL CLOUDS THROUGH THE DAY WED. NORTHERLY FLOW MUCH OF THE AFTERNOON...WITH SOME GUSTS 15-20KTS PSBL. THE NORTH WIND CONTINUE INTO WED BUT SHOULD DIMINISH DURING THE DAY AS THE HIGH DROPS IN. KMSP... VFR CONDS EXPECTED INTO THE EVENING. SOME THREAT OF MVFR CIGS DEVELOPING INTO THE COMING EVENING...WITH BEST CHANCES EAST OF THE AIRPORT. NORTH WINDS THROUGH MOST OF THE PERIOD...BECOMING MORE WEST LATER WED AFTERNOON AS THE SURFACE RIDGE MOVES IN. /OUTLOOK FOR KMSP/ WED NIGHT...VFR. CHC MVFR CIG -SN. W TO SW WIND 8 KTS. THU...VFR. SW WIND 5-10 KTS. FRI...VFR. W 10-15 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JRB LONG TERM...JRB AVIATION...DWE
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1255 PM CDT TUE MAR 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 339 AM CDT TUE MAR 11 2014 THE MODEL CONSENSUS SHOWS A STRONG AREA OF 700-500MB FRONTOGENESIS DEVELOPING ACROSS NERN NEB AROUND 18Z TODAY. THIS FGEN IS EXPECTED TO PRODUCE A FAIRLY STRONG BAND OF WET SNOW WITH HOURLY LIQUID RATES OF UP TO 0.10 INCHES. THE NAM RADAR PRODUCT SHOWS THIS BAND SETTING UP FROM AROUND CHAMBERS TO BROKEN BOW AT 21Z WHICH MOVES QUICKLY EAST OF THE FCST AREA BY 00Z. THE NAM HAS BEEN WOBBLING SOMEWHAT BUT THE CONCEPT OF FOLDED THETA E AND DEEP LIFT IN THE DENDRITIC GROWTH ZONE CONTINUES. THE 05Z RAP MODEL SETS IT UP FROM ONEILL TO SUTHERLAND. THE 00Z ECM FOLLOWS THE NAM WHICH MATCHES THE MODEL CONSENSUS. IN GENERAL...THE MODELS ARE CLUSTERING AROUND 0.20 INCHES OF LIQUID FOR THIS EVENT ALONG HIGHWAY 83 BUT THEN SPREAD OUT TO THE EAST AS SOME SIGNAL A WETTER EVENT AND OTHERS DRIER. THE MEDIAN QPF IN CUSTER COUNTY LOOKS TO BE AROUND 0.30 INCHES. GIVEN THE STRONG LIFT DEVELOPING...IT IS EXPECTED THERE WILL BE A PERIOD OF MODERATE TO HEAVY SNOW DEVELOPING LASTING 1 OR 2 HOURS AT THE MOST. THIS IS ABOUT A 6 HOUR PCPN EVENT WHICH EXITS THE FCST AREA BY AROUND 00Z. THERE IS A SHORT PERIOD OF RAIN BEFORE CHANGE OVER TO SNOW IN THE GFS AND NAM MODELS. H700MB TEMPERATURES COOL VERY RAPIDLY BEHIND THE COLD FRONT MARKING THE ONSET OF PCPN AND DEEP LIFT WILL AID THE DYNAMIC COOLING PROCESS. AN 8 TO 1 SNOW WATER RATIO WAS USED UP NORTH DURING THE MORNING HOURS WHICH WAS REDUCED TO 5 TO 1 DURING THE AFTERNOON. TEMPERATURES FALL TO THE LOW TO MID 30S DURING THE HEAVIEST SNOW AND THEN WARM UP ONCE THE SNOW LETS UP OR ENDS. THIS PRODUCED 1 TO 2 INCHES OF WET SNOW. THERE IS NO REASON TO UNDER ESTIMATE A SPRING STORM DURING THE 2ND WEEK OF MARCH AND THE SYSTEM FORECAST TO DEVELOP TODAY IS EXPECTED TO PRODUCE STRONG NORTH WINDS AS THE SFC LOW DEEPENS ACROSS EAST CENTRAL KANSAS. ALL MODELS SHOW 500M AGL WINDS INCREASING TO OVER 30 KT WHICH TRANSLATES TO 30 MPH AT THE SFC. THE NAM...GFS GUIDANCE...HRRR AND RAP MODELS ALL SHOW GUSTS TO NEAR 50 MPH DEVELOPING ACROSS CNTL NEB NORTH OF THE SFC LOW LOCATED ACROSS KS BY NOON TODAY. H850 WINDS INCREASE TO 45 TO 55 KT. THE WIND FORECAST IS A CONSENSUS OF MODEL GUIDANCE OUTPUT AND DETERMINISTIC SOLNS WHICH FOLLOWS THE MIDDLE ROAD. THE GFS AND THE ECM SPREAD THESE STRONGER WINDS FURTHER NORTH AND WEST THAN THE OTHER MODELS. A WEAK DISTURBANCE IS SHOWN BY THE MODELS TO MOVE ACROSS THE FCST AREA TONIGHT. THIS COULD PRODUCE SNOW FLURRIES OR PERHAPS ISOLATED SNOW SHOWER ACTIVITY AS IT TRANSLATES EAST ACROSS THE FCST AREA. LAPSE RATES STEEPEN AND REMAIN MOIST SUPPORTING THIS FORECAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 339 AM CDT TUE MAR 11 2014 THE SYSTEM BRINGING THE SNOW AND WIND TO THE FORECAST AREA TODAY AND TONIGHT WILL MOVE EAST AND BE PAST THE LOCAL AREA BY 12Z WEDNESDAY. THIS WILL PUT NEBRASKA UNDER SUBSIDENT AIR WEDNESDAY AND WITH DRY AIR ADVECTING IN EXPECTING MOSTLY SUNNY SKIES. ALTHOUGH NOT EXPECTING ADVISORY LEVEL WINDS WEDNESDAY...SIGNALS ARE COMING TOGETHER FOR A BREEZY DAY. MODELS ARE SHOWING A SECONDARY PV MAX DROPPING SOUTH ACROSS CENTRAL NEBRASKA THROUGH THE DAY...TO HELP ENHANCE WINDS ALOFT AND WITH STEEP SURFACE TO 700MB LAPSE RATES CONFIDENCE INCREASES ON BREEZY CONDITIONS. SOUNDINGS SHOW THE MIXED LAYER BETWEEN 700MB AND 800MB AND LOOKING AT MAXIMUM WINDS IN THAT LAYER UP TO 35KTS SO DECIDED TO INCREASE WINDS DURING THE DAY. TEMPERATURES ALOFT DON/T CHANGE SIGNIFICANTLY ON WEDNESDAY SO LOOKING AT AN ADIABATIC PROFILE...HIGHS WOULD BE IN THE 40S FOR MOST LOCATIONS. HOWEVER...MODELS HAVE BEEN CONSISTENTLY A BIT COOL FOR TEMPERATURES AND WITH SUNNY SKIES THINK MOST AREAS WILL WARM A BIT MORE THAN THE DETERMINISTIC MODELS ARE INDICATING. DRY WEATHER IS EXPECTED THROUGH FRIDAY NIGHT AS NO SIGNIFICANT SYSTEMS ARE SET TO MOVE ACROSS THE CENTRAL PLAINS. AN UPPER LEVEL LOW WILL STAY FAIRLY STATIONARY OVER THE SOUTHWEST THROUGH FRIDAY...WHILE THE NORTHERN STREAM WILL KEEP NORTHWEST FLOW ACROSS THE AREA. THERE WILL BE AN APPROACHING SHORTWAVE TROUGH ON THURSDAY AS IT WILL BE MOVING OVER THE NORTHERN ROCKIES. THERE IS A BIT OF UNCERTAINTY ON HOW AMPLIFIED THIS SHORTWAVE TROUGH WILL BE...WHICH IMPACTS HOW STRONG THE SURFACE LOW WILL BECOME AND THEN HOW MUCH WARM AIR CAN BE PULLED NORTHWARD. TOOK A MIDDLE OF THE ROAD APPROACH FOR HIGH TEMPERATURES THURSDAY...WITH FORECAST HIGHS IN THE UPPER 50S AND 60S. IF THE SYSTEM BECOMES A BIT STRONGER...TEMPERATURES WILL LIKELY NEED TO BE RAISED FOR THURSDAY. THE COLD FRONT ASSOCIATED WITH THIS UPPER LEVEL SYSTEM WILL PASS ACROSS NEBRASKA THURSDAY AFTERNOON AND EVENING. ALTHOUGH THERE CONTINUES TO BE QUITE A BIT OF DISAGREEMENT IN MODEL SOLUTIONS ON WHERE THE MAIN ENERGY WITH THIS SYSTEM WILL PASS...IT DOES APPEAR FAIRLY CERTAIN THAT IT WILL BE WELL NORTH OF THE FORECAST AREA. WITH THE MAJORITY OF THE MOISTURE ACROSS THE NORTH STAYING NEAR THE LOW CENTER...FOR PRECIPITATION TO OCCUR WOULD NEED A MOISTURE SOURCE FROM THE SOUTH TO GET THIS TO HAPPEN AS THE FRONT MOVES THROUGH. HOWEVER THE UPPER LOW TO THE SOUTHWEST WILL LIKELY PROHIBIT MUCH MOISTURE TRANSPORT INTO THE AREA FROM THE SOUTH. ONE THING THAT DOES LOOK POSSIBLE IS STRONG WINDS THURSDAY NIGHT. WITH THE AREA STAYING IN A LOCATION WITH DRY AIR...WHEN THE AIRMASS BECOMES SUBSIDENT BEHIND THE FRONT...DOWNWARD MOTION WILL BE PROMOTED. ALTHOUGH TIMING IS NIGHT...WHICH ISN/T AS FAVORABLE FOR STRONGER WINDS...WILL NEED TO CONTINUE TO WATCH THIS TIME-FRAME IN THE NEXT FEW DAYS CONCERNING WINDS. THE MODELS REALLY BEGIN TO DIVERGE BEGINNING SATURDAY AS THEY SEEM TO BE HAVING PROBLEMS HANDLING THE SOUTHWEST UPPER LOW. ONE THING THEY DO ALL AGREE ON IS THAT STRONG RIDGING WILL BUILD IN...SOMEWHERE ACROSS THE WESTERN HALF OF THE COUNTRY INTO THE FIRST PART OF NEXT WEEK. DESPITE THE MODEL DIFFERENCES...THEY ALSO ARE INDICATING THE PATTERN ALOFT BECOMING MORE AMPLIFIED AND DIG A SHORTWAVE TROUGH SOUTH ALONG THE LEE-SIDE OF THE ROCKY MOUNTAINS OVER THE WEEKEND. CONTINUE TO HAVE PRECIPITATION CHANCES THROUGH MUCH OF THE WEEKEND...WITH BOTH RAIN AND SNOW LOOKING POSSIBLE. TEMPERATURE PROFILES SHOW PRECIPITATION TYPE AS RAIN ON SATURDAY...THEN SWITCHING TO RAIN/SNOW AND SNOW SATURDAY NIGHT...THEN BACK TO RAIN ON SUNDAY. THIS MAY NOT BE REAL LIKELY...AS THERE WON/T BE THAT GREAT AMOUNT OF TIME WITH RAIN AND SNOW...BUT WITH CONCERN OVER TIMING AND LOCATION OF THE PRECIPITATION...DID NOT HAVE THE CONFIDENCE YET TO NAIL DOWN A PARTICULAR PRECIPITATION TYPE. THE VERY END OF THE FORECAST PERIOD LOOKS INTERESTING...WITH A STRONG COLD FRONT TO PASS MONDAY NIGHT AND TUESDAY. DYNAMICS WITH THIS SYSTEM ARE PRETTY STRONG...WHICH COULD LEAD TO VERY WARM TEMPERATURES MONDAY...THEN CHANCES FOR PRECIPITATION MONDAY NIGHT AND TUESDAY...AND STRONG WINDS TUESDAY. DIDN/T GO TOO WARM WITH TEMPERATURES FOR MONDAY AT THIS TIME AS CONFIDENCE ON FORECASTING THE HIGHS THE DETERMINISTIC MODELS SHOW AT THIS TIME IS QUITE LOW...BUT IT BEARS WATCHING OVER THE COMING DAYS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1252 PM CDT TUE MAR 11 2014 COLD FRONT IS THROUGH THE AREA......WITH NORTHERLY WIND GUSTS IN THE 20 TO 35 KT RANGE. PRECIP CHANCES CONTINUE THIS AFTERNOON...WITH HEAVIER MOISTURE CHANCES ACROSS SW NEB. TEMPS ARE IN THE MID 30S...SO PRECIP TYPE IS A MIX OF RAIN AND SNOW OR ALL SNOW. CONDITIONS WILL START TO IMPROVE ACROSS THE NORTH...LATER THIS AFTERNOON INTO THE EVENING. MEANWHILE FUTHER SOUTH...LIGHT RAIN/DRIZZLE WILL CHANGE OVER TO MORE SNOW AS A BAND DEVELOPS FOR THE AFTERNOON. BY THIS EVENING THIS BAND WILL SHIFT SOUTH. MVFR/IFR CONDITIONS WILL IMPROVE TO VFR OVERNIGHT ALTHOUGH A WEAK DISTURBANCE WILL BRING A SLGHT CHC FOR FLURRIES/SPRINKLES EARLY TONIGHT ACROSS MUCH OF THE AREA. TOMORROW VFR AND BREEZY CONDITIONS CAN BE ANTICIPATED. && .LBF WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 8 PM CDT /7 PM MDT/ THIS EVENING FOR NEZ025>029-036>038-057>059-069>071. && $$ SHORT TERM...CDC LONG TERM...BROOKS AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1229 PM CDT TUE MAR 11 2014 .UPDATE... ISSUED AT 1018 AM CDT TUE MAR 11 2014 HAVE UPDATED TO CUT EXPECTED SNOW AMOUNTS...LARGELY FOR LACK OF COOLING BUT ALSO FOR LESS PRECIPITATION EXPECTED OVER OUR SOUTHEAST CORNER...THAT IS NORTHWEST IOWA AWAY FROM THE NORTHERN STATE BORDER. THE WEAKNESS OF THE COOLING IS ALLOWING ACCUMULATING SNOW TO FALL ONLY IN THE AREAS OF HEAVIER PRECIPITATION...AND THERE IS NOT MUCH OF THAT GOING TO BE LEFT. THE EXCEPTION IS FROM NORTH OF BROOKINGS INTO LINCOLN COUNTY MN WHERE THERE HAVE BEEN SOME ACCUMULATIONS ON ROADS...BUT EVEN THERE THE PRECIPITATION WILL MOVE OUT SOON. A REPORT FROM MARSHALL MINNESOTA INDICATED 0.37 INCH OF PRECIPITATION AND NO SNOW. HAVE ALSO CUT PRECIPITATION MENTION OUT FOR THIS EVENING FAR SOUTHEAST. TEMPERATURES WILL DO NOTHING EXCITING WITH THE CLOUD COVER AND STIFF NORTHERLY BREEZE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 424 AM CDT TUE MAR 11 2014 COMPLEX FORECAST TODAY AS A BAND OF PRECIPITATION MOVES SOUTHEAST ACROSS THE CWA. AS OF 4 AM THIS BAND IS ALONG AND NORTH OF HIGHWAY 14. THIS MATCHES WELL WITH A STRONG AREA OF MID LEVEL FRONTOGENESIS. DECENT INSTABILITY ABOVE THE FRONT...THUS NOT SURPRISED BY THE HIGH REFLECTIVITY CURRENTLY ON RADAR. BOUNDARY LAYER REMAINS QUITE WARM...AND THUS PRECIPITATION TYPE IS CURRENTLY RAIN. THIS FIRST AREA OF FRONTOGENESIS SHIFTS SOUTH THIS MORNING...BUT ALSO BEGINS TO WEAKEN. THIS OCCURS AS THE MAIN WAVE EJECTS OUT OF THE ROCKIES...WITH THE BEST QG FORCING SOUTH OF THE MISSOURI RIVER. THUS MAKES SENSE THAT WE SEE FRONTOGENESIS INTENSIFY AGAIN SOUTH OF INTERSTATE 90 AS MODELS SHOW. SO EXPECT WE SEE THE MODERATE TO HEAVY BAND ALONG HIGHWAY 14 SLOWLY WEAKEN THIS MORNING AS IT MOVES SOUTH...THEN INTENSIFY AGAIN THIS AFTERNOON SOUTH OF INTERSTATE 90 AS THE FRONT STRENGTHENS AND INTERACTS WITH THE UPPER WAVE. PRETTY LARGE UNCERTAINTY ON HOW MUCH THE BAND WEAKENS THIS MORNING...AND HOW QUICKLY IT INTENSIFIES THIS AFTERNOON. THIS IS IMPORTANT NOT ONLY FOR QPF...BUT ALSO PRECIPITATION TYPE. IF PRECIPITATION STAYS ON THE LIGHTER SIDE...IT WILL LIKELY STAY MAINLY RAIN. ONLY EXPECTING A CHANGEOVER TO SNOW DUE TO DYNAMIC COOLING IN THE HEAVIEST PRECIPITATION. SO IF THIS HEAVIER BAND WEAKENS ENOUGH...OUR SNOW FORECAST COULD BE IN TROUBLE. THE LATEST 06Z NAM AND HRRR AND RAP DO SHOW THIS MORE PRONOUNCED WEAKENING...SO WILL HAVE TO KEEP AN EYE ON THIS. EVEN AS THE BAND INTENSIFIES SOUTH OF INTERSTATE 90 THIS AFTERNOON...BOUNDARY LAYER COULD BE WARM ENOUGH TO KEEP THINGS RAIN...OR JUST A WET NON ACCUMULATING SNOW. SO FOR NOW...WILL KEEP 1 TO 2 INCHES IN THE FORECAST FOR MOST OF THE CWA...BUT WILL NEED TO MONITOR TEMPERATURE TRENDS THROUGH THE DAY. FOLLOWED CLOSE TO THE ARW AND NAM FOR TIMING...WITH THE BAND IMPACTING INTERSTATE 90 MID TO LATE MORNING...AND NORTHWEST IOWA LATE MORNING INTO THE AFTERNOON. SKIES WILL STAY MOSTLY CLOUDY TONIGHT...AND AS A SECONDARY WAVE DROP SOUTH...COULD SEE SOME SCATTERED SNOW SHOWERS DEVELOP AFTER MIDNIGHT. BASED ON LATEST MODEL RUNS DID SHIFT THIS SNOW SHOWER AREA FURTHER WEST FROM THE PREVIOUS FORECAST...CENTERED MORE BETWEEN THE JAMES RIVER AND INTERSTATE 29 CORRIDOR. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 424 AM CDT TUE MAR 11 2014 FOR THE MEDIUM RANGE...HAVE SIDED CLOSER TO A BLEND OF THE CANADIAN/GFS AND ECMWF. OPTED TO EXCLUDE THE NAM AS IT SEEMED TO BE THE OUTLIER IN TERMS OF THE PROGRESSION OF SYSTEMS AND SEEMED TO BE SLOWER THAN THE OTHER SOLUTIONS. MODELS SUGGEST BAND OF LIGHT SNOW SHOWERS EARLY ON WEDNESDAY THOUGH SATURATION IN THE DENDRITIC LAYER APPEARS TO BE A SIGNIFICANT ISSUE. MODEL SOUNDINGS VARY FROM SOLUTION TO SOLUTION...BUT IN GENERAL...ALL HINT AT ONLY A LIMITED AMOUNT OF THE DENDRITIC LAYER SATURATING AND WITH THE WARMER AIR BEGINNING TO RETURN IT APPEARS AS THOUGH THE CHANCE OF DEVELOPING THROUGHOUT THE MORNING DECREASES WITH TIME. HAVE KEPT LOW CHANCE POPS THROUGH THE EARLY MORNING HOURS...BUT DROPPED TO FLURRIES IN THE LATE MORNING IF ANYTHING IS LEFT BY THEN. EXPECT NICE WARMING WEDNESDAY INTO THURSDAY...HOWEVER STRATUS MAY LINGER AHEAD OF THE WARM FRONT ACROSS THE EASTERN CWA ON WEDNESDAY LIMITING WARMING POTENTIAL. WARMED HIGHS ON THURSDAY WITH CLEAR SKIES AND NICE SOUTHWEST FLOW ALOFT RESULTING IN 925 HPA TEMPS WARMING INTO THE 10-13C RANGE. COLD FRONT MOVES THROUGH THE AREA ON THURSDAY NIGHT. SHORT WAVE MOVES THROUGH MINNESOTA LATE THURSDAY NIGHT INTO FRIDAY. FOR THE MOST PART...IT APPEARS AS THOUGH THE WAVE IS FOCUSED EAST OF THE FORECAST AREA...SO LEFT FORECAST DRY FOR THE TIME BEING. BACK DOOR COLD FRONT MOVES INTO THE UPPER MIDWEST FRIDAY NIGHT. FRONT WORKS BACK TO THE WEST ON SATURDAY...WITH COOL NORTHEAST FLOW EAST OF THE FRONT. A SERIES OF SHORT WAVES APPEAR TO MOVE THROUGH THE AREA ON SATURDAY NEAR THE FRONT...POTENTIALLY CREATING SOME LIGHT RAIN/SNOW DEPENDING WHICH SIDE OF THE FRONT A PARTICULAR LOCATION IS ON. THE FRONT BEGINS TO SHIFT EAST ACROSS THE REGION ON SUNDAY LEADING TO A WARMING TREND. STRONG SOUTHERLY FLOW DEVELOPS ON MONDAY...LEADING A WARM BUT WINDY DAY. INCREASED WINDS ON MONDAY COMPARED TO THE GUIDANCE BUT MAY NOT HAVE INCREASED ENOUGH WITH 20-30 KNOTS OF FLOW THROUGH THE AFTERNOON HOURS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1229 PM CDT TUE MAR 11 2014 SOUTHEAST OF MJQ/FSD/YKN LINE WIDESPREAD CEILINGS 1-3K FEET AND AREAS OF VISIBILITIES 3-5SM IN -RASN WILL IMPROVE FROM THE NORTHWEST BY 12/00Z TO VFR WITH A FEW AREAS OF CEILINGS 1-3K FEET. OVER THE NORTHERN AND WESTERN PARTS OF THE FORECAST AREA...GENERALLY VFR...BUT A FEW AREAS OF CEILINGS 1-3K FEET MAINLY BEFORE 12/00Z AND AFTER 12/06Z. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE... SHORT TERM...CHENARD LONG TERM... AVIATION...
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1253 PM CDT TUE MAR 11 2014 .UPDATE... UPDATED FOR 18Z AVIATION DISCUSSION. ALSO REMOVED OKLAHOMA PANHANDLE AND NORTH CENTRAL AND NORTHEAST TEXAS PANHANDLE COUNTIES FROM THE RED FLAG WARNING. HIGH TEMPERATURES WERE ALSO INCREASED OVER MUCH OF THE AREA. && .AVIATION.../18Z TAFS/ NO SIGNIFICANT CHANGES WERE MADE TO THE 18Z TAF FORECAST AS WIND GUSTS AND BLOWING DUST APPEAR TO BE THE MAIN FORECAST CHALLENGES. NORTHWEST TO MOSTLY NORTH WINDS WITH GUSTS UP TO 50KTS CAN BE EXPECTED AT ALL TAF LOCATIONS THROUGH 06Z. AN AVIATION WEATHER WARNING IS IN EFFECT UNTIL 1AM. THERE IS SOME CONCERN THAT MVFR CEILINGS MAY DEVELOP AS THE COLD FRONT MOVES SOUTH...BUT NOT CONFIDENT ENOUGH TO INCLUDE AT THIS TIME. WITH ANY BLDU THAT OCCURS...VISIBILITIES WILL DECREASE AND COULD DROP SIGNIFICANTLY. AS AN EXAMPLE...PERRYTON, TEXAS IS CURRENTLY REPORTING 1 3/4SM. NORTHERLY SURFACE WINDS WILL DECREASE AFTER 06Z WITH GUSTS STILL UP TO 30KTS NOT OUT OF THE QUESTION. KNS && .FIRE WEATHER... CRITICAL FIRE WEATHER CONCERNS REMAIN FOR AREAS SOUTH OF A LINE FROM DALHART TO CANADIAN WHICH IS SOUTH OF A COLD FRONT BEGINNING TO MOVE ACROSS THE FAR NORTHERN PANHANDLES. BEHIND THIS FRONT...RH VALUES HAVE BEEN ABLE TO RECOVER THUS CRITICAL FIRE WEATHER CONDITIONS ARE NO LONGER ANTICIPATED AND THE RED FLAG WARNING HAS BEEN CANCELLED FOR ALL OF THE OKLAHOMA PANHANDLE AS WELL AS SHERMAN...HANSFORD..OCHILTREE...AND LIPSCOMB COUNTIES. A FIRE DANGER STATEMENT HAS REPLACED THE CANCELLED RED FLAG WARNING FOR THESE COUNTIES. FOR THE REST OF THIS AFTERNOON AND EVENING...CRITICAL FIRE WEATHER CONCERNS WILL REMAIN ESPECIALLY ACROSS THE SOUTHERN TEXAS PANHANDLE. AS THE COLD FRONT SINKS SOUTH...THE COUNTIES BEHIND THE FRONT WILL SEE RELATIVE HUMIDITIES INCREASE BUT WINDS WILL ALSO INCREASE AS WELL. THE WORST CRITICAL FIRE WEATHER CONDITIONS ARE FORECAST TO BE ACROSS THE SOUTHWEST TEXAS PANHANDLE WHERE THE LOWEST RH VALUES WILL RESIDE (COUPLED WITH STRONG WINDS EXPECTED TO INCREASE). KNS/JJ && .DISCUSSION... HIGH TEMPERATURES WERE INCREASED ACROSS THE ENTIRE AREA AND ESPECIALLY ACROSS THE SOUTHERN TEXAS PANHANDLE WITH MID TO UPPER 70S AND A FEW 80S EXPECTED. BEHIND THE COLD FRONT ACROSS THE OKLAHOMA PANHANDLE AND FAR NORTHERN TEXAS PANHANDLE...HIGH TEMPERATURES WERE INCREASED 1 TO 3 DEGREES BASED ON CURRENT TRENDS ALTHOUGH NOT EXPECTING TOO MUCH MORE OF AN INCREASE AS THE COLD FRONT MOVES THROUGH THESE AREAS. ALL OTHER WEATHER PARAMETERS WERE TWEAKED BASED ON CURRENT TRENDS. CLK/KNS && .PREV DISCUSSION... /ISSUED 1030 AM CDT TUE MAR 11 2014/ FIRE WEATHER... BIG CONCERN THIS AFTERNOON IS ON FIRE WEATHER POTENTIAL. DUE TO SOUTHWEST WINDS BEHIND A SURFACE TROUGH, OVERNIGHT RELATIVE HUMIDITY RECOVERIES WERE VERY POOR FOR LOCATIONS ON THE CAPROCK WITH RELATIVE HUMIDITY VALUES ONLY CLIMBING UP TO 35%. SEVERAL LOCATIONS EVEN STAYED BELOW 30% ALL NIGHT. RECOVERIES WERE SLIGHTLY HIGHER AHEAD OF THE SURFACE TROUGH ACROSS THE EASTERN PANHANDLES WHERE RELATIVE HUMIDITY VALUES RANGED BETWEEN 50 AND 80%. WHAT THIS ESSENTIALLY MEANS IS THAT FINE FUEL MOISTURE NEVER HAD A CHANCE TO MOISTEN AT ALL FOR MOST LOCATIONS OVERNIGHT. RELATIVE HUMIDITY VALUES WILL CONTINUE TO REMAIN VERY LOW FOR MUCH OF THE DAY UNTIL A COLD FRONT PASSES THROUGH LATER TODAY. SPEAKING OF THE COLD FRONT, IT CURRENTLY STRETCHES FROM NEAR HILL CITY, KS TO GARDEN CITY, KS TO SPRINGFIELD, CO. THIS FRONT WILL ENTER OUR FORECAST AREA AFTER 11 AM, AND MOVE SOUTHWARD THROUGH THE AFTERNOON. APPROXIMATE COLD FRONT TIMING: GUYMON: 1 PM DALHART AND PERRYTON: 1-2 PM DUMAS, BORGER, AND PAMPA: 3-4 PM AMARILLO: 4-5 PM SHAMROCK: 5-6 PM HEREFORD: 6-7 PM ONE OF THE BIGGEST QUESTION MARKS IS HOW STRONG WINDS WILL BE THIS AFTERNOON AHEAD OF THE FRONT. RAW RUC AND NAM SOUNDINGS SUGGEST MARGINAL WINDS FOR RED FLAG CONDITIONS IN OUR AREA. HOWEVER, PREFER THE HIGHER MET AND MAV WINDS (WHICH IS CURRENTLY IN THE FORECAST) AS MOS GUIDANCE TENDS TO DO RELATIVELY WELL ON THESE DOWNSLOPE WIND DAYS. WILL LEAVE THE RED FLAG WARNING IN TACT, BUT OUR HIGHEST CONFIDENCE FOR SEEING CRITICAL FIRE WEATHER CONDITIONS WILL BE SOUTH OF A CLAYTON TO CANADIAN LINE. THE ROLLER COASTER RIDE OF FUEL MOISTURE OVER THE LAST MONTH IS CLEARLY SEEN IN TEXAS FOREST SERVICE ENERGY RELEASE COMPONENT (ERC) DATA. AFTER LAST WEEK`S MOISTURE, WE HAVE QUICKLY DRIED OUT AGAIN. IN FACT, FORECAST ERC VALUES TODAY ARE 67 AT BOOTLEG, 62 AT CEDAR, AND 60 AT WHEELER. THESE VALUES ARE GETTING VERY CLOSE TO THE 90% PERCENTILE, AT WHICH LOCAL RESEARCH SUGGESTS SIGNIFICANT FIRE POTENTIAL BECOMES AN INCREASING CONCERN. WITH THESE DRYING FUELS AND A LITTLE MORE FAVORABLE FIRE WEATHER CONDITIONS, IT`S NOT A BIG SURPRISE THAT WE SAW A SLIGHT UPTICK IN INITIAL ATTACK ACTIVITY YESTERDAY. TFS SIGNIFICANT FIRE POTENTIAL MATRICES SHOW A MODERATE TO NEAR HIGH POTENTIAL FOR SIGNIFICANT FIRE TODAY, ESPECIALLY ACROSS THE FAR SOUTHWESTERN TEXAS PANHANDLE. THE AXIS OF A BROAD 850 MB THERMAL RIDGE WILL STRETCH FROM NORTHEASTERN NEW MEXICO INTO THE SOUTHWESTERN TEXAS PANHANDLE INTO THE SOUTH PLAINS. THE ALIGNMENT OF THE STRONGEST LOW-/MID-LEVEL WINDS WILL GENERALLY OCCUR ALONG AND SOUTH OF THIS AXIS. IT IS ALSO IN THESE LOCATIONS THAT TEMPERATURES WILL BE 5 TO 15 DEGREES ABOVE NORMAL, WHICH ALSO SUPPORTS HIGHER FIRE DANGER PER LOCAL RESEARCH. THEREFORE, BASED ON FUELS AND WEATHER, THE HIGHEST PROBABILITIES (AND THEY ARE STILL ON THE LOW SIDE) OF SIGNIFICANT FIRE WEATHER POTENTIAL WILL REMAIN SOUTH AND WEST OF A HEREFORD TO HAPPY LINE. DESPITE THIS, FIRE OFFICIALS AND EMERGENCY MANAGERS SHOULD REMAIN ON HEIGHTENED ALERT, ESPECIALLY CONSIDERING THAT WINDS WILL SHIFT FROM THE NORTHWEST TO THE NORTH AND INCREASE SUBSTANTIALLY (GUSTS UP TO 60 MPH) BEHIND THE COLD FRONT LATER THIS AFTERNOON AND EVENING. THIS WILL BE OF UTMOST IMPORTANCE IN THE EVENT OF ANY FIRE STARTS OR ONGOING FIRES BEFORE THEN! JACKSON && .PREV DISCUSSION... /ISSUED 641 AM CDT TUE MAR 11 2014/ AVIATION... 12Z TAFS...WEST WINDS INITIALLY THIS MORNING WILL VEER TO THE NORTHWEST BY MID TO LATE MORNING AND INCREASE TO 20-25 KTS WITH GUSTS OF 30-35 KTS. A COLD FRONT WILL WORK SOUTH THROUGH THE AREA THIS AFTERNOON...WITH WINDS TURNING TO THE NORTH BEHIND THE FRONT AND INCREASING TO NEAR 35 KTS WITH GUSTS TO AROUND 50 KTS POSSIBLE. SOME VSBY REDUCTIONS WILL BE POSSIBLE FROM BLDU BEHIND THE FRONT THIS AFTERNOON AND EVENING. WINDS WILL DECREASE FROM NORTH TO SOUTH LATE THIS EVENING AND OVERNIGHT. OUTSIDE OF ANY BLDU...VFR CONDITIONS ARE EXPECTED. AN AVIATION WEATHER WARNING IS IN EFFECT FOR KAMA FROM 22Z TODAY THROUGH 06Z WEDNESDAY FOR THE STRONG WINDS. KB && .PREV DISCUSSION... /ISSUED 406 AM CDT TUE MAR 11 2014/ DISCUSSION... UPPER LEVEL SHORT WAVE TROUGH OVER WYOMING NOW WILL ELONGATE AND SPLIT AS IT DIVES SOUTH THROUGH COLORADO AND KANSAS TODAY. A POWERFUL COLD FRONT WILL BLAST ITS WAY SOUTH ACROSS THE PANHANDLES THIS AFTERNOON AND EVENING IN ASSOCIATION WITH THE PASSAGE OF THE SHORT WAVE TROUGH. SURFACE PRESSURE GRADIENT IS VERY TIGHT BETWEEN LOW PRESSURE OVER NORTH CENTRAL TEXAS AND HIGH PRESSURE OVER WYOMING BY LATE THIS AFTERNOON AND EARLY THIS EVENING. THIS TIGHT PRESSURE GRADIENT IS EXPECTED TO BRING NORTH WINDS OF 30 TO 40 MILES AN HOUR ACROSS THE PANHANDLES WITH GUST TO AROUND 60 MILES AN HOUR IN SOME SPOTS. HAVE GONE AHEAD AND TURNED THE HIGH WIND WATCH INTO A HIGH WIND WARNING FOR MUCH OF THE CWA. ONLY THE FAR EAST CENTRAL AND SOUTHEAST TEXAS PANHANDLE WILL BE IN A WIND ADVISORY. BLOWING DUST MAY ALSO REDUCE VISIBILITIES TO ONE MILE OR LESS AT TIMES. RED FLAG WARNING CRITERIA IS ALSO EXPECTED TO BE MET ACROSS THE CWA TODAY AS RELATIVE HUMIDITY VALUES DROP TO 15 PERCENT OR BELOW AHEAD AND JUST BEHIND THE COLD FRONT. THE WIND SHIFT AND SUDDEN INCREASE IN THE WIND WILL ALSO CAUSE UNPREDICTABLE FIRE BEHAVIOR SHOULD A FIRE START. WINDS WILL SLOWLY DECREASE AFTER MIDNIGHT AND SHOULD BE BELOW 20 MPH BY MID MORNING ON WEDNESDAY. THE MODELS STILL WANT TO PAINT SOME VERY LIGHT QPF...MAINLY ACROSS THE NORTHERN CWA...THURSDAY NIGHT INTO FRIDAY IN ASSOCIATION WITH THE SECOND SHORT WAVE TROUGH APPROACHING FROM THE WEST. FOR NOW WILL LEAVE THE FORECAST DRY AS IT LOOKS LIKE MOISTURE WILL BE LACKING. THE NEXT SYSTEM TO AFFECT THE PANHANDLES WILL ARRIVE BY THE SECOND HALF OF THE WEEKEND. THIS SYSTEM SLIDES SOUTHEAST ON THE EAST SIDE OF A WEST COAST RIDGE AND IT INTENSIFIES AS IT MOVES INTO THE SOUTHERN HIGH PLAINS. AGAIN...THE MODELS WANT CHANGE THEIR TUNE SINCE IT IS A NEW DAY. THEREFORE...WILL NOT INSERT ANY PRECIP FOR LATE NEXT WEEKEND AT THIS TIME. .FIRE WEATHER... CRITICAL FIRE WEATHER CONDITIONS WILL BE FOUND ACROSS THE PANHANDLES TODAY AND THIS EVENING. LOWEST AFTERNOON RELATIVE HUMIDITY VALUES WILL GET DOWN INTO THE 5 TO 15 PERCENT RANGE ACROSS MUCH OF THE PANHANDLES. RELATIVE HUMIDITY VALUES WILL START TO RECOVER SOME BEHIND A COLD ACROSS THE OKLAHOMA PANHANDLE AND THE NORTHERN TEXAS PANHANDLE BY MID AFTERNOON... BUT WINDS WILL BE INCREASING BEHIND THE COLD FRONT SO ANY ONGOING FIRES COULD HAVE ERRATIC BEHAVIOR DUE TO THE SHIFTING WINDS WITH THE FRONT. WINDS WILL DECREASE SLOWLY AFTER MIDNIGHT TONIGHT AND THEY WILL BE BELOW 15 MPH BY AROUND MID MORNING ON WEDNESDAY. ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS THE PANHANDLES AGAIN ON THURSDAY AS SOUTHWEST WINDS INCREASE AND RELATIVE HUMIDITY VALUES DROP. && .AMA WATCHES/WARNINGS/ADVISORIES... TX...HIGH WIND WARNING UNTIL 1 AM CDT WEDNESDAY FOR THE FOLLOWING ZONES: CARSON...DALLAM...DEAF SMITH...GRAY...HANSFORD... HARTLEY...HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE... OLDHAM...POTTER...RANDALL...ROBERTS...SHERMAN. RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...HARTLEY...HEMPHILL...HUTCHINSON... MOORE...OLDHAM...POTTER...RANDALL...ROBERTS...WHEELER. WIND ADVISORY UNTIL 1 AM CDT WEDNESDAY FOR THE FOLLOWING ZONES: ARMSTRONG...COLLINGSWORTH...DONLEY...HEMPHILL...WHEELER. OK...HIGH WIND WARNING UNTIL 1 AM CDT WEDNESDAY FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS. && $$ KNS/CLK/JJ
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1224 PM CDT TUE MAR 11 2014 .UPDATE... INITIAL MIXING THIS PRODUCED SLIGHTLY STRONGER WINDS THAN EXPECTED...MAINLY FROM DENVER CITY THROUGH LUBBOCK TOWARD FLOYDADA AND SILVERTON...WHERE LOW END ADVISORY CRITERIA WAS SEEN AT TIMES. SODAR AT REESE CENTER SHOWING WINDS ALOFT WEAKENING SOME WHILE AT THE SFC INITIAL WIND SHIFT AHEAD OF THE STRONG COLD FRONT STILL BACK FURTHER TO THE NORTH SHOULD PRODUCE A WEAKNESS IN THE PRESSURE GRADIENT THAT ALSO POINTS TO WINDS DECREASING INTO THE FCST WIND SPEED RANGE BY EARLY AFTN. AS A RESULT WILL NOT MAKE ANY CHANGES TO THE FIRST PERIOD FCST ATTM. && .AVIATION... GUSTY WEST WINDS TO BECOME NW THIS AFTN THEN NORTH THIS EVENING PRETTY MUCH AS EXPECTED. BLOWING DUST AT KLBB CAME EARLIER AND DENSER THAN INITIALLY EXPECTED...BUT APPEARS WINDS WILL WEAKEN JUST ENOUGH EARLY IN THE PERIOD TO SEE SFC VSBY INCREASE TO 5SM OR GREATER BEFORE COMING BACK DOWN THIS EVENING BEHIND THE STRONG COLD FRONT. && .PREV DISCUSSION... /ISSUED 700 AM CDT TUE MAR 11 2014/ AVIATION... GUSTY WEST TO NORTHWEST WINDS ARE EXPECTED FOR MOST OF THE DAY TODAY. PATCHY BLDU MAY CAUSE LOCAL VSBY REDUCTIONS. THIS EVENING...A STRONG COLD FRONT WILL QUICKLY PASS THROUGH THE AREA. SUSTAINED WIND SPEEDS COULD APPROACH 30 KTS AT EITHER OR BOTH TERMINALS AND REQUIRE AN AIRPORT WEATHER WARNING. ALSO...THERE WILL LIKELY BE A PERIOD OF HIGHER DUST CONCENTRATIONS WHICH COULD RESULT IN MVFR VSBYS AT KLBB. WINDS WILL SLOWLY DECREASE WEDNESDAY MORNING AND THE DUST WILL SETTLE. VFR CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE FORECAST. PREV DISCUSSION... /ISSUED 403 AM CDT TUE MAR 11 2014/ SHORT TERM... THE STAGE IS SET FOR A EARLY SPRING STRONG WIND/BLOWING DUST AND FIRE WEATHER EVENT TODAY AND TONIGHT. 3 AM SAT IMAGERY AND UPPER-AIR ANALYSIS SHOW A SHARP SHORTWAVE MOVING QUICKLY THROUGH THE INTER-MOUNTAIN WEST. THIS WAVE WILL MOVE ROUGHLY EWD INTO THE CENTRAL PLAINS TODAY...PLACING THE CWA ON THE SRN FLANK OF THE MID-LVL JET MAX WITHIN THE BASE OF THE TROUGH. IN ADDITION...A WEAK SFC TROUGH EXTENDING SWD FROM A LOW IN FAR NE COLO THROUGH THE WRN PANHANDLES INTO ERN NM WILL DEEPEN AND MOVE EAST TODAY. TIGHTENING THE SFC PRESSURE GRADIENT WHILE WINDS SWING AROUND TO THE WEST THEN W-NW. FINALLY...A STRONG COLD FRONT IS MOVING INTO NRN COLO AND WRN NE...THIS FRONT WILL BE THE MAIN DRIVER OF STRONG WINDS THIS EVENING/TONIGHT...MORE ON THAT LATER. WINDS ARE EXPECTED TO PICK UP PRETTY QUICKLY THIS MORNING...THE WEST TEXAS SODAR AT REESE CENTER ALREADY SHOWS 30+ KTS AT 500 FT AGL. WHILE WE DO HAVE SOME SHALLOW MOISTURE IN PLACE ACROSS THE ERN CWA THIS MORNING...UNFORTUNATELY...THIS MOISTURE WILL BE SCOURED OUT QUICKLY AND CRITICAL FIRE WEATHER CONDITIONS COULD DEVELOP BEFORE NOON /SEE DISCUSSION BELOW/. IN GENERAL...WE EXPECT WINDS TO RISE INTO THE 25 TO 35 MPH RANGE ACROSS THE AREA TODAY...SLIGHTLY LOWER IN THE ROLLING PLAINS AND SLIGHTLY MORE ACROSS THE W-SW. THESE WINDS WILL LIKELY REMAIN JUST BELOW ADVISORY LEVELS BUT SHOULD BE SUFFICIENT TO LOFT SOME PATCHY BLOWING DUST. TEMPS WILL BE QUITE WARM FOR MOST OF THE AREA...WITH HIGHS IN THE 80S...PERHAPS PUSHING 90F IN THE SRN ROLLING PLAINS...WHILE CAA COMING IN FROM THE NW SHOULD KEEP TEMPS IN THE 70S ACROSS THE FAR SW TX PANHANDLE AND WRN SPLNS. LATE THIS AFTERNOON...ATTENTION WILL TURN TO THE COLD FRONT WHICH IS EXPECTED TO BE BARRELING SOUTH THROUGH THE PANHANDLES. WHILE GUIDANCE IS IN GOOD AGREEMENT THAT THE FRONT/S PROGRESS WILL BE QUICKER IN THE EAST...LAGGING IN THE WEST...THERE IS STILL A FEW HOURS OF DISAGREEMENT IN THE TIMING OF THE FRONT. WE ARE FAVORING THE HIGH-RES GUIDANCE FROM THE RAP AND THE TTU-WRF...WHICH SHOWS THE FRONT ENTERING CHILDRESS COUNTY AROUND 23 UTC...AND PARMER COUNTY AROUND 00 UTC. BUT OF COURSE THE ACTUAL FROPA COULD VARY A COUPLE HOURS EITHER WAY. AS NOTED PREVIOUSLY...MODELS ARE SHOWING VERY IMPRESSIVE PRESSURE RISES BEHIND THE FRONT THIS EVENING. OBJECTIVE GUIDANCE SUGGESTS THAT WIND SPEEDS COULD REACH HIGH WIND CRITERIA /SUSTAINED SPEED OF AT LEAST 40 MPH AND/OR GUSTS IN EXCESS OF 57 MPH/ ACROSS THE NRN HALF OF THE FA. WE ARE A LITTLE SKEPTICAL THAT WE WILL SEE SUSTAINED HIGH WINDS IN THE LOWER TERRAIN OF THE ROLLING PLAINS...BUT WE ARE PLANNING ON EXTENDING THE HIGH WIND WATCH SOUTH AND EAST ACROSS MUCH OF THE CAPROCK....WITH SOLID ADVISORY-LEVEL WINDS EXPECTED ELSEWHERE. SOMEWHAT INTERESTINGLY...THERE IS A PRONOUNCED WEAKNESS PROGGED IN THE 800-700MB WIND FIELD ACROSS MUCH OF OUR AREA AROUND 0Z. THIS SHOULD NOT HAVE MUCH OF AN IMPACT ON THE OVERALL FCST BUT DEPENDING ON THE TIMING OF THE FRONT...IT COULD LEAD TO A SHORT-DURATION LULL IN GUSTY WINDS BEFORE A BIG INCREASE WITH THE FROPA. AS FOR BLOWING DUST...WE ARE LOOKING FOR A CONCENTRATION OF DIRT AND REDUCTION IN VISIBILITY ALONG AND IMMEDIATELY IN THE WAKE OF THE FRONT...BUT WE DON/T HAVE ANY STRONG INDICATIONS AT THIS TIME THAT VISIBILITIES WILL DROP TO ADVISORY OR DUST STORM LEVELS. THIS IS PARTLY DUE TO THE WIND DIRECTION AND OUR EXPECTATION THAT THE FRONT WILL MOVE THROUGH AFTER PEAK MIXING. IF THE FRONT IS FASTER/STRONGER THAN EXPECTED...THEN DENSE BLOWING DUST MAY BE A GREATER CONCERN. LONG TERM... AFTER THE ACTIVE SHORT TERM...THE EXTENDED FORECAST SEEMS RELATIVELY BENIGN BY COMPARISON. GUSTY NORTHERLY WINDS EARLY WEDNESDAY WILL GRADUALLY WEAKEN THROUGH THE DAY AS THE PRESSURE GRADIENT RELAXES AND SURFACE RIDGING SETTLES SQUARELY OVER WEST TEXAS. IT WILL BE CONSIDERABLY COOLER BEHIND THIS EVENINGS FROPA...WITH HIGHS ON WEDNESDAY TOPPING OUT AROUND 10 DEGREES BELOW MID-MARCH AVERAGES. SHORTWAVE RIDGING ALOFT WILL FOLLOW ON THURSDAY WHICH WHEN COUPLED WITH RETURN FLOW ON THE BACK SIDE OF THE DEPARTING SURFACE RIDGE AND RENEWED SURFACE TROUGHING IN THE LEE OF THE ROCKIES WILL MEAN BREEZY SOUTHERLY WINDS WITH TEMPERATURES RECOVERING TO NEAR AVERAGE. ATTENTION WILL THEN TURN WEST TO A CUTOFF UPPER LOW THAT WILL HANG OUT OVER THE GREAT BASIN MID-WEEK. THIS UPPER LOW WILL GET KICKED EASTWARD LATE WEEK AS JET ENERGY MOVES INTO THE PACIFIC NORTHWEST. THERE REMAINS SOME TIMING DIFFERENCES...BUT WHAT IS LEFT OF THE UPPER LOW WILL RACE ACROSS THE SOUTH PLAINS FRIDAY OR FRIDAY NIGHT. UNFORTUNATELY...THIS SYSTEM WILL NOT HAVE MUCH IN THE WAY OF LOW-LEVEL MOISTURE TO WORK WITH...BUT THE GFS AND ECMWF DO CONTINUE TO PAINT POCKETS OF VERY LIGHT QPF SOMEWHERE IN OR NEAR THE CWA. GIVEN THIS SIGNAL...WE WOULD NOT BE SURPRISED TO SEE A FEW SPRINKLES OR LIGHT SHOWERS...BUT THE CHANCE OF MEASURABLE RAIN STILL APPEARS LOW AND WE HAVE MAINTAINED POPS AROUND 10 PERCENT. THE TIMING UNCERTAINTY WITH THE PASSING WAVE DOES ALSO CREATE LOWER CONFIDENCE ON WHEN THE ASSOCIATED FROPA WILL OCCUR. A QUICKER SYSTEM/FRONT COULD MEAN TEMPERATURES A LITTLE COOLER THAN WHAT IS CURRENTLY DEPICTED IN THE FORECAST...THOUGH EITHER WAY THE SYSTEM WILL NOT HAVE MUCH COOL AIR TO WORK WITH. THE FIRST HALF OF THE WEEKEND WILL START OUT ON THE MILD SIDE...WITH HIGHS EXPECTED TO TOP OUT IN THE 60S AND LOWER 70S. HOWEVER...A SHORTWAVE TROUGH IS PROGGED TO DIVE SOUTH-SOUTHEASTWARD TOWARD THE REGION SATURDAY NIGHT. AT A MINIMUM...THIS DISTURBANCE SHOULD HELP DRIVE A DECENT COLD FRONT THROUGH...DROPPING TEMPERATURES BACK BELOW AVERAGE FOR THE SECOND HALF OF THE WEEKEND. LESS CERTAIN IS EXACTLY WHAT LONGITUDE THIS DISTURBANCE PASSES AND THUS WHETHER OR NOT IT CAN BRING A WINDOW FOR PRECIPITATION CHANCES TO THE SOUTH PLAINS. THE MOST RECENT ECMWF HAS TRENDED BACK FURTHER WEST AND WETTER...WHILE THE GFS TRACK IS MORE EASTWARD WHICH WOULD LIKELY BE DRY FOR THE SOUTH PLAINS. WE HAVE MAINTAINED SILENT POPS AROUND 10 PERCENT FOR NOW AND WILL WAIT TO MAKE A MOVE ONE WAY OR THE OTHER UNTIL THE NWP CAN COME INTO BETTER AGREEMENT. REGARDLESS...WARMER AND DRY WEATHER SHOULD KICK OFF EARLY NEXT WEEK AS THE UPPER TROUGH DEPARTS AND SOUTHERLY TO SOUTHWESTERLY SURFACE FLOW REDEVELOPS. FIRE WEATHER... LATEST INDICATIONS ARE THAT CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP ACROSS THE ENTIRE SOUTH PLAINS AREA TODAY AND WE WILL EXPAND AND UPGRADE THE WATCH TO A RED FLAG WARNING FOR OUR WHOLE CWA. DESPITE HIGH RH VALUES ACROSS THE EASTERN SOUTH PLAINS AND ROLLING PLAINS EARLY THIS MORNING...VERY DRY AIR WILL SPREAD EAST RESULTING IN RH VALUES DROPPING UNDER 15 PERCENT BY 10 AM FOR MANY AREAS...AND INTO THE SINGLE DIGITS ACROSS THE ENTIRE AREA THIS AFTERNOON. WHILE WIND SPEEDS MAY BE ON THE LOW END OF CRITERIA ACROSS THE ERN ROLLING PLAINS...IT APPEARS THAT WIND SPEEDS AND RH VALUES WILL SUPPORT AN EXTREMELY CRITICAL DANGER FOR MUCH OF THE SOUTHWEST AND SOUTHERN SOUTH PLAINS. WINDS MAY RELAX FOR A PERIOD AROUND 6 TO 7 PM...BUT THE PASSAGE OF A STRONG COLD FRONT IN THE EVENING WILL BRING AN ABRUPT WIND SHIFT TO THE NORTH AND MUCH STRONGER WINDS SPEEDS. ALTHOUGH COOLING TEMPS AND RISING RH VALUES WILL BEGIN TO REDUCE THE FIRE DANGER...WE WILL KEEP THE RED FLAG WARNING GOING THROUGH 9 PM CDT DUE TO THIS STRONG FRONT. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 71 25 52 24 60 / 0 0 0 0 0 TULIA 76 28 54 25 63 / 0 0 0 0 0 PLAINVIEW 77 29 55 26 63 / 0 0 0 0 0 LEVELLAND 78 30 54 26 63 / 0 0 0 0 0 LUBBOCK 80 32 56 28 64 / 0 0 0 0 0 DENVER CITY 80 31 55 25 61 / 0 0 0 0 0 BROWNFIELD 81 33 56 26 63 / 0 0 0 0 0 CHILDRESS 83 34 58 31 65 / 0 0 0 0 0 SPUR 85 35 58 30 65 / 0 0 0 0 0 ASPERMONT 88 36 58 29 65 / 0 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 10 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: TXZ021>044. WIND ADVISORY FROM 7 PM THIS EVENING TO 3 AM CDT WEDNESDAY FOR THE FOLLOWING ZONES: TXZ021>044. && $$ 07
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 PM CDT TUE MAR 11 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 309 PM CDT TUE MAR 11 2014 THE MAIN FOCUS THROUGH TOMORROW IS WITH HOW FAST THE BAND OF PRECIPITATION SHIFTS TO THE SOUTH TONIGHT FOLLOWED BY SNOW SHOWER CHANCES TOMORROW MORNING ALONG WITH HOW COLD IT WILL BE. SURFACE/LOW LEVEL TEMPERATURES PROVED TO BE A TAD TOO WARM TODAY TO CAUSE MUCH IF ANY SNOW TO DEVELOP ALONG THE BAND OF PRECIPITATION. 11.17Z RAP SOUNDINGS CONTINUE TO SHOW THAT THE LOW LEVELS SHOULD STAY WARM ENOUGH INTO THIS EVENING TO MAINLY YIELD RAIN WITH A BRIEF TRANSITION TO SNOW ON THE BACK/NORTH SIDE OF THE BAND. THE 17.12Z HRRR/RAP SHOW THIS BAND GETTING SOUTH OF DUBUQUE BY MID EVENING. AS A DEEPENING SURFACE LOW TRACKS TO THE SOUTHEAST OF THE REGION OVERNIGHT INTO TOMORROW MORNING...AN INVERTED SURFACE TROUGH WILL ROTATE FROM EAST TO WEST ACROSS THE REGION AS A SHORT WAVE MID LEVEL TROUGH DROPS DOWN FROM ONTARIO. WITH COLDER AIR MOVING IN WITH THIS TROUGH A SATURATED LAYER SHOULD DEVELOP IN THE ICE NUCLEATION ZONE BELOW -8C WITH JUST ENOUGH LIFT FROM THE SURFACE TROUGH TO PRODUCE SOME SNOW SHOWERS. 11.12Z WRF-ARW/NMM REFLECTIVITY GUIDANCE SHOWS A BAND OF SNOW SHOWERS DEVELOPING IN EASTERN WISCONSIN OVERNIGHT AND TRACKING TO THE SOUTHWEST THROUGH THE REGION TOMORROW MORNING. SUBSIDENCE THEN TAKES OVER AND SHOULD HELP TO CLEAR SKIES OUT A BIT GOING INTO THE AFTERNOON...BUT TEMPERATURES WILL STRUGGLE TO CLIMB MUCH WITH 850MB TEMPERATURES AROUND -15C. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 309 PM CDT TUE MAR 11 2014 THE NEXT CHANCE FOR SOME LIGHT SNOW COMES IN ON WEDNESDAY NIGHT/EARLY THURSDAY MORNING AS A RIDGE OF HIGH PRESSURE PUSHES TO THE EAST AND SOME LOW LEVEL WARM AIR ADVECTION SWINGS THROUGH THE REGION. THERE ARE SOME DIFFERING OPINIONS BETWEEN THE 11.12Z NAM/GFS/ECMWF/GEM WITH THIS BAND AND HOW STRONG THE WAA WILL BE. THE GFS IS THE FASTEST WITH HAVING THE SNOW COME IN ON WEDNESDAY EVENING WHILE THE NAM IS A TAD SLOWER AND STRONGER WITH THE WAA AND PRODUCES A LITTLE MORE QPF. THE ECMWF/GEM ARE BOTH MUCH WEAKER WITH THIS SYSTEM AND HARDLY SHOW ANY QPF AT ALL...SO THERE IS SOME UNCERTAINTY WITH WHETHER ANYTHING WILL OCCUR FROM THIS. COBB DATA FROM THE GFS/NAM WOULD SAY A HALF INCH OF ACCUMULATION OR LESS IF THE SNOW DOES OCCUR. TEMPERATURES WILL CLIMB BACK TOWARD NORMAL THURSDAY WITH SOUTHWESTERLY SURFACE WINDS. A WEAK COLD FRONT WILL COME THROUGH ON FRIDAY THOUGH TEMPERATURES SHOULD NOT DROP MUCH UNTIL THE WEEKEND COMES AND NORTHWESTERLY FLOW ALOFT SETS UP. REMOVED THE CHANCES FOR PRECIPITATION ON SUNDAY AS IT LOOKS LIKE THE SHORT WAVE TROUGH DIVING SOUTH OUT OF SOUTH CENTRAL CANADA WILL RUN TO THE WEST OF THE REGION. THE BETTER CHANCES APPEAR TO COME ON TUESDAY AS THE 11.12Z ECMWF BRINGS A SYSTEM OUT OF THE PLAINS AND TO THE SOUTH OF THE UPPER MISSISSIPPI RIVER VALLEY. THE 11.12Z GFS IS MUCH FURTHER TO THE NORTH WITH THIS SYSTEM AND WOULD BRING WARMER AIR INTO THE REGION. QUITE A BIT OF UNCERTAINTY OUT THERE...BUT ENOUGH TO WARRANT SOME CHANCES FOR PRECIPITATION ON TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1225 PM CDT TUE MAR 11 2014 A BAND OF -RA...AND A LITTLE -SN...WITH MVFR/LCL IFR CIGS/VSBYS WILL CONTINUE TO SINK SOUTH ACROSS THE AREA EARLY THIS AFTERNOON. THIS BAND LOOKS TO CLEAR THE TAF SITES BETWEEN 18-20Z WITH THE NORTH WINDS BRINGING IN DRIER LOW LEVEL AIR...VFR VSBYS AND CIGS RISING INTO THE 6K-10K FT RANGE. GENERALLY GOOD VFR CONDITIONS THEN EXPECTED FOR MID TO LATE AFTERNOON INTO THE OVERNIGHT HOURS. ANOTHER WEATHER DISTURBANCE WILL DROP ACROSS THE AREA LATE TONIGHT AND EARLY WEDNESDAY MORNING. A PERIOD OF MVFR CIGS AND SCT FLURRIES/-SHSN EXPECTED TO ACCOMPANY THIS DISTURBANCE ACROSS THE AREA...MAINLY BETWEEN 09Z-15Z WED. SUBSIDENCE/DRYING BEHIND THIS FEATURE THEN LOOKS TO DECREASE THE CLOUDS WITH VFR CONDITIONS FOR LATER WED MORNING AND WED AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...HALBACH LONG TERM...HALBACH AVIATION.....RRS