Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/24/15
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
825 AM MDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 821 AM MDT SUN MAR 22 2015
EARLY UPDATE THIS MORNING AS WAVE CLOUDS ARE FAIRLY THICK AND HAVE
SPREAD ACROSS THE NORTHEAST PLAINS. PROBABLY ENOUGH MIXING THAT
OUR HIGHS ARE ALRIGHT. REST OF FORECAST UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 443 AM MDT SUN MAR 22 2015
UPPER LEVEL RIDGING WILL CONTINUE OVER COLORADO TODAY WITH
TEMPERATURES WELL ABOVE SEASONAL NORMALS. THERE WILL BE A MODEST
INCREASE IN MOISTURE ALOFT THROUGH THIS AFTERNOON AND EVENING AS
THE UPPER RIDGE BEGINS WEAKENING AHEAD OF AN UPPER TROUGH MOVING
OUT OF THE PACIFIC NORTHWEST. THE NAM AND GFS GENERATE SHOWER
ACTIVITY OVER THE MOUNTAINS THIS AFTERNOON AND EVENING...BUT THE
LATEST RUNS OF THE RAP KEEP CONDITIONS OVER COLORADO DRY THROUGH
03Z. WATER VAPOR IMAGERY SHOWS INCREASED MOISTURE OVER NEVADA AND
UTAH BUT INFRARED SATELLITE PICTURES ONLY SHOW INCREASING CLOUDS
OVER EASTERN UTAH AT THIS TIME. SINCE THE PREVIOUS FORECAST
ALREADY HAD SOME LOW POPS IN THE MOUNTAINS THIS AFTERNOON AND
EVENING...WILL STICK WITH THAT FOR NOW. WITH THE AIRMASS STARTING
OUT SO WARM...WILL MENTION THE PRECIPITATION BEGINNING AS RAIN OR
A MIX OF RAIN AND SNOW. POPS WILL MAX OUT IN THE 40-50 PERCENT
RANGE DURING THE LATTER HALF OF THE AFTERNOON.
WINDS ACROSS NORTHEAST COLORADO TODAY MAY BE AFFECTED BY A WEAK
SURFACE FRONT MOVING OUT OF WYOMING. CURRENTLY...ANY PRESSURE
RISES OVER WYOMING ARE WEAK...BUT AS THE LEE TROUGH THAT HAS BEEN
IN PLACE OVER NORTHEAST COLORADO MOVES AWAY FROM THE FOOTHILLS
WINDS SHOULD BECOME NORTHERLY LATE IN THE MORNING AND
NORTHEASTERLY LATER IN THE AFTERNOON. THE COMBINATION OF WEAK
NORTH WINDS AND GRADUALLY INCREASING CLOUDS SHOULD KEEP HIGH
TEMPERATURES AT AROUND THE SAME NUMBERS THEY WERE YESTERDAY
AFTERNOON.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 443 AM MDT SUN MAR 22 2015
THE FLOW ALOFT WILL BECOME MORE WSW ON MON AHEAD OF AN UPPER LVL
THAT WILL MOVE QUICKLY ACROSS WY AND NRN CO MON NIGHT. AT THE SFC
LOW PRES WILL INTENSIFY FM ERN WY INTO ERN CO WITH INCREASING SSE
LOW LVL FLOW ACROSS THE PLAINS. CROSS-SECTIONS SHOW MOISTURE WILL
INCREASE IN THE MTNS BY LATE AFTN SO WILL KEEP IN A CHC OF SHOWERS
MAINLY NORTH OF I-70. ACROSS THE PLAINS IT WILL BE MAINLY DRY
EXCEPT FOR A SLIGHT CHC OF CONVECTION NR THE WY-CO BORDER. AS FOR
HIGHS WILL KEEP READINGS IN THE UPPER 60S TO LOWER 70S ACROSS NERN
CO.
FOR MON NIGHT INTO EARLY TUE A QUICK MOVING UPPER LEVEL TROUGH WILL
AFFECT THE AREA WITH A DECENT SHOT OF MID LVL ASCENT ALONG WITH
RATHER STEEP LAPSE RATES. THUS SHOULD SEE SNOW INCREASE IN THE MTNS
MON EVENING BUT THEN DECREASE BY TUE MORNING. SOME AREAS COULD GET
CLOSE TO LOWER END ADVISORY AMOUNTS NORTH OF I-70. AT LOWER
ELEVATIONS WITH STEEP LAPSE RATES AND FAVORABLE MID LVL ASCENT
THERE WILL BE A CHC OF SHOWERS AND A FEW TSTMS MON NIGHT
ESPECIALLY NR THE WY-NE BORDER WITH LOWER CHANCES FURTHER SOUTH.
ON TUE THE UPPER LEVEL TROUGH WILL EXIT THE AREA TUE MORNING WITH
STG DOWNWARD DESCENT THRU THE AFTN HOURS. ALTHOUGH OROGRAPHICS WILL
REMAIN FAVORABLE IN THE MTNS MOISTURE DEPTH WILL BE MARGINAL THRU
THE AFTN SO ANY ADDITIONAL ACCUMULATIONS WILL BE ON THE LIGHT SIDE.
OVER NERN CO WITH STG DOWNWARD FORCING IN PLACE DO NOT EXPECT ANY
PCPN ALTHOUGH THERE COULD BE A FEW LINGERING SHOWERS OVER THE FAR
NERN CORNER IN THE MORNING. MEANWHILE WITH DECENT LOW LVL GRADIENT
IN PLACE AND DOWNWARD DESCENT EXPECT FAIRLY STG WINDS FM THE NRN
FOOTHILLS ACROSS THE PLAINS. WINDS COULD GET CLOSE TO WARNING
CRITERIA FOR A FEW HOURS ESPECIALLY CLOSER TO THE WY-NE BORDER.
ALSO CONSIDERING HOW DRY IT HAS BEEN OVER PORTIONS OF THE PLAINS
BLOWING DUST WILL CERTAINLY BE POSSIBLE AS WELL. AS FOR HIGHS
READINGS WILL COOL BACK INTO THE LOWER TO MID 60S OVER NERN CO.
FOR TUE NIGHT AND WED THE FLOW ALOFT WILL BECOME MORE NWLY WITH A
DISTURBANCE POSSIBLY AFFECTING THE AREA ON WED. MOISTURE WILL
INCREASE IN THE MTNS WITH FAVORABLE OROGRAPHICS AND LAPSE RATES SO
SHOULD SEE A GOOD CHC OF SNOW. AT LOWER ELEVATIONS A CDFNT WILL
MOVE ACROSS NERN CO LATE TUE NIGHT INTO WED MORNING WITH NLY LOW LVL
FLOW. AS THE DISTURBANCE MOVES ACROSS DURING THE DAY THERE MAY BE
AT LEAST A SLIGHT CHC OF LIGHT PCPN BEHIND THE FNT SO WILL KEEP IN
LOW POPS OVER NERN CO. AS FOR HIGHS THE ECWMF HAS READINGS IN THE
40S OVER NERN CO WHILE THE GFS HAS TEMPS IN THE 50S. FOR NOW WILL
KEEP HIGHS IN THE LOWER TO MID 50S.
FOR WED NIGHT INTO THU NWLY FLOW ALOFT WILL REMAIN OVER THE AREA.
THE ECMWF AND GFS STILL DISAGREE AS TO HOW MUCH MOISTURE IS EMBEDDED
IN THE FLOW AND WHETHER ANOTHER SURGE OF COOLER AIR WILL AFFECT NERN
CO. THE ECMWF CONTINUES TO SHOW VERY LITTLE MOISTURE ON THU AND
DOES NOT HAVE ANOTHER FNT AFFECTING THE PLAINS. AS A RESULT IT HAS
NO PCPN AND SHOWS WARMER TEMPS. MEANWHILE THE GFS HAS SOME
MOISTURE EMBEDDED IN THE FLOW AND SHOWS ANOTHER FNT MOVING ACROSS
NERN CO DURING THE DAY. THIS LEADS TO A CHC OF SNOW IN THE MTNS
AND POSSIBLY SOME LIGHT PCPN OVER NERN CO. WILL CONTINUE TO KEEP
POPS ON THE LOW SIDE ON THU SINCE THERE IS NO AGREEMENT BETWEEN
THE TWO MODELS. AS FAR AS HIGHS WILL KEEP READINGS IN THE 50S OVER
NERN CO.
BY FRI AND SAT BOTH THE ECMWF AND GFS SHOW DRY NWLY FLOW ALOFT OVER
THE AREA WITH NO PCPN. HIGHS WILL GRADUALLY RISE BOTH DAYS WITH 70S
POSSIBLY BY SATURDAY OVER NERN CO.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 821 AM MDT SUN MAR 22 2015
VFR THROUGH TONIGHT. STILL EXPECTING A SHIFT TO NORTHERLY WINDS
AROUND 16Z. ISOLATED SHOWERS IN THE LATE AFTERNOON AND EVENING
SHOULD HAVE LITTLE OR NO IMPACT AS CEILINGS WILL REMAIN HIGH.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GIMMESTAD
SHORT TERM...DANKERS
LONG TERM...RPK
AVIATION...GIMMESTAD
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
443 AM MDT SUN MAR 22 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 443 AM MDT SUN MAR 22 2015
UPPER LEVEL RIDGING WILL CONTINUE OVER COLORADO TODAY WITH
TEMPERATURES WELL ABOVE SEASONAL NORMALS. THERE WILL BE A MODEST
INCREASE IN MOISTURE ALOFT THROUGH THIS AFTERNOON AND EVENING AS
THE UPPER RIDGE BEGINS WEAKENING AHEAD OF AN UPPER TROUGH MOVING
OUT OF THE PACIFIC NORTHWEST. THE NAM AND GFS GENERATE SHOWER
ACTIVITY OVER THE MOUNTAINS THIS AFTERNOON AND EVENING...BUT THE
LATEST RUNS OF THE RAP KEEP CONDITIONS OVER COLORADO DRY THROUGH
03Z. WATER VAPOR IMAGERY SHOWS INCREASED MOISTURE OVER NEVADA AND
UTAH BUT INFRARED SATELLITE PICTURES ONLY SHOW INCREASING CLOUDS
OVER EASTERN UTAH AT THIS TIME. SINCE THE PREVIOUS FORECAST
ALREADY HAD SOME LOW POPS IN THE MOUNTAINS THIS AFTERNOON AND
EVENING...WILL STICK WITH THAT FOR NOW. WITH THE AIRMASS STARTING
OUT SO WARM...WILL MENTION THE PRECIPITATION BEGINNING AS RAIN OR
A MIX OF RAIN AND SNOW. POPS WILL MAX OUT IN THE 40-50 PERCENT
RANGE DURING THE LATTER HALF OF THE AFTERNOON.
WINDS ACROSS NORTHEAST COLORADO TODAY MAY BE AFFECTED BY A WEAK
SURFACE FRONT MOVING OUT OF WYOMING. CURRENTLY...ANY PRESSURE
RISES OVER WYOMING ARE WEAK...BUT AS THE LEE TROUGH THAT HAS BEEN
IN PLACE OVER NORTHEAST COLORADO MOVES AWAY FROM THE FOOTHILLS
WINDS SHOULD BECOME NORTHERLY LATE IN THE MORNING AND
NORTHEASTERLY LATER IN THE AFTERNOON. THE COMBINATION OF WEAK
NORTH WINDS AND GRADUALLY INCREASING CLOUDS SHOULD KEEP HIGH
TEMPERATURES AT AROUND THE SAME NUMBERS THEY WERE YESTERDAY
AFTERNOON.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 443 AM MDT SUN MAR 22 2015
THE FLOW ALOFT WILL BECOME MORE WSW ON MON AHEAD OF AN UPPER LVL
THAT WILL MOVE QUICKLY ACROSS WY AND NRN CO MON NIGHT. AT THE SFC
LOW PRES WILL INTENSIFY FM ERN WY INTO ERN CO WITH INCREASING SSE
LOW LVL FLOW ACROSS THE PLAINS. CROSS-SECTIONS SHOW MOISTURE WILL
INCREASE IN THE MTNS BY LATE AFTN SO WILL KEEP IN A CHC OF SHOWERS
MAINLY NORTH OF I-70. ACROSS THE PLAINS IT WILL BE MAINLY DRY
EXCEPT FOR A SLIGHT CHC OF CONVECTION NR THE WY-CO BORDER. AS FOR
HIGHS WILL KEEP READINGS IN THE UPPER 60S TO LOWER 70S ACROSS NERN
CO.
FOR MON NIGHT INTO EARLY TUE A QUICK MOVING UPPER LEVEL TROUGH WILL
AFFECT THE AREA WITH A DECENT SHOT OF MID LVL ASCENT ALONG WITH
RATHER STEEP LAPSE RATES. THUS SHOULD SEE SNOW INCREASE IN THE MTNS
MON EVENING BUT THEN DECREASE BY TUE MORNING. SOME AREAS COULD GET
CLOSE TO LOWER END ADVISORY AMOUNTS NORTH OF I-70. AT LOWER
ELEVATIONS WITH STEEP LAPSE RATES AND FAVORABLE MID LVL ASCENT
THERE WILL BE A CHC OF SHOWERS AND A FEW TSTMS MON NIGHT
ESPECIALLY NR THE WY-NE BORDER WITH LOWER CHANCES FURTHER SOUTH.
ON TUE THE UPPER LEVEL TROUGH WILL EXIT THE AREA TUE MORNING WITH
STG DOWNWARD DESCENT THRU THE AFTN HOURS. ALTHOUGH OROGRAPHICS WILL
REMAIN FAVORABLE IN THE MTNS MOISTURE DEPTH WILL BE MARGINAL THRU
THE AFTN SO ANY ADDITIONAL ACCUMULATIONS WILL BE ON THE LIGHT SIDE.
OVER NERN CO WITH STG DOWNWARD FORCING IN PLACE DO NOT EXPECT ANY
PCPN ALTHOUGH THERE COULD BE A FEW LINGERING SHOWERS OVER THE FAR
NERN CORNER IN THE MORNING. MEANWHILE WITH DECENT LOW LVL GRADIENT
IN PLACE AND DOWNWARD DESCENT EXPECT FAIRLY STG WINDS FM THE NRN
FOOTHILLS ACROSS THE PLAINS. WINDS COULD GET CLOSE TO WARNING
CRITERIA FOR A FEW HOURS ESPECIALLY CLOSER TO THE WY-NE BORDER.
ALSO CONSIDERING HOW DRY IT HAS BEEN OVER PORTIONS OF THE PLAINS
BLOWING DUST WILL CERTAINLY BE POSSIBLE AS WELL. AS FOR HIGHS
READINGS WILL COOL BACK INTO THE LOWER TO MID 60S OVER NERN CO.
FOR TUE NIGHT AND WED THE FLOW ALOFT WILL BECOME MORE NWLY WITH A
DISTURBANCE POSSIBLY AFFECTING THE AREA ON WED. MOISTURE WILL
INCREASE IN THE MTNS WITH FAVORABLE OROGRAPHICS AND LAPSE RATES SO
SHOULD SEE A GOOD CHC OF SNOW. AT LOWER ELEVATIONS A CDFNT WILL
MOVE ACROSS NERN CO LATE TUE NIGHT INTO WED MORNING WITH NLY LOW LVL
FLOW. AS THE DISTURBANCE MOVES ACROSS DURING THE DAY THERE MAY BE
AT LEAST A SLIGHT CHC OF LIGHT PCPN BEHIND THE FNT SO WILL KEEP IN
LOW POPS OVER NERN CO. AS FOR HIGHS THE ECWMF HAS READINGS IN THE
40S OVER NERN CO WHILE THE GFS HAS TEMPS IN THE 50S. FOR NOW WILL
KEEP HIGHS IN THE LOWER TO MID 50S.
FOR WED NIGHT INTO THU NWLY FLOW ALOFT WILL REMAIN OVER THE AREA.
THE ECMWF AND GFS STILL DISAGREE AS TO HOW MUCH MOISTURE IS EMBEDDED
IN THE FLOW AND WHETHER ANOTHER SURGE OF COOLER AIR WILL AFFECT NERN
CO. THE ECMWF CONTINUES TO SHOW VERY LITTLE MOISTURE ON THU AND
DOES NOT HAVE ANOTHER FNT AFFECTING THE PLAINS. AS A RESULT IT HAS
NO PCPN AND SHOWS WARMER TEMPS. MEANWHILE THE GFS HAS SOME
MOISTURE EMBEDDED IN THE FLOW AND SHOWS ANOTHER FNT MOVING ACROSS
NERN CO DURING THE DAY. THIS LEADS TO A CHC OF SNOW IN THE MTNS
AND POSSIBLY SOME LIGHT PCPN OVER NERN CO. WILL CONTINUE TO KEEP
POPS ON THE LOW SIDE ON THU SINCE THERE IS NO AGREEMENT BETWEEN
THE TWO MODELS. AS FAR AS HIGHS WILL KEEP READINGS IN THE 50S OVER
NERN CO.
BY FRI AND SAT BOTH THE ECMWF AND GFS SHOW DRY NWLY FLOW ALOFT OVER
THE AREA WITH NO PCPN. HIGHS WILL GRADUALLY RISE BOTH DAYS WITH 70S
POSSIBLY BY SATURDAY OVER NERN CO.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 443 AM MDT SUN MAR 22 2015
NO AVIATION IMPACTS FROM WEATHER TODAY AND TONIGHT. HIGH CLOUDS
WILL BE GRADUALLY INCREASING THIS AFTERNOON AND OVERNIGHT BUT
CEILINGS SHOULD REMAIN ABOVE 8000 FEET AGL. SOUTHERLY WINDS THIS
MORNING ARE EXPECTED TO SWITCH TO NORTHERLY LATE IN THE MORNING
THEN NORTHEAST TO EASTERLY LATE IN THE AFTERNOON AND EVENING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DANKERS
LONG TERM...RPK
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
136 PM EDT SUN MAR 22 2015
.SYNOPSIS...
SEVERAL WAVES OF LOW PRESSURE WILL PASS SOUTH OF THE AREA ALONG A
STALLED FRONT THEN SHIFT OFFSHORE INTO THE ATLANTIC TODAY AND
TONIGHT. AN INLAND WEDGE OF HIGH PRESSURE WILL THEN STRENGTHEN ON
MONDAY AS ANOTHER AREA OF LOW PRESSURE SHIFTS OFF THE SOUTHEAST
COAST. HIGH PRESSURE WILL LEAD TO DRY CONDITIONS TUESDAY WITH A
WARMING TREND INTO FRIDAY AHEAD OF THE NEXT COLD FRONT.
UNSEASONABLY COOL TEMPERATURES ARE THEN LIKELY AT THE END OF THE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE RAIN HAS BEEN PRETTY LIGHT SO FAR AND MAINLY CONCENTRATED
ACROSS THE CENTRAL AND NORTHERN PARTS OF THE FORECAST AREA. THE
RAIN WILL REMAIN FAIRLY LIGHT FOR THE REMAINDER OF THE AFTERNOON
AS THE 850 HPA WARM FRONT MEANDERS OVERHEAD. THE EXPECTED
TIGHTENING OF THE ELEVATED FRONT HAS BEEN DELAYED SOMEWHAT PER
LATEST RAP UPPER AIR PROGS...BUT THE LOW-LEVEL JET THAT WILL
ENHANCED RAINFALL FOR THE NEXT 12 HOURS SO IS JUST NOW MOVING INTO
THE WESTERN FLORDIA PANHANDLE/SOUTHWEST GEORGIA WHERE RADAR
COMPOSITES SHOW AN INCREASING AREA OF MODERATE TO HEAVY RAIN ALONG
THE GULF COAST. HAVE REORIENTED POPS BASED ON CURRENT RADAR AND
SHORT TERM MODEL TRENDS. THIS YIELDS CONSIDERABLY LOWER POPS AND
QPF SOUTH OF THE I-16 CORRIDOR. HAVE ALSO NUDGED LOWS DOWN 1-2
DEGS ACROSS THE NORTH AND RAISED THEM 1-2 DEGREES ACROSS THE SOUTH
WHERE RAIN WILL BE MUCH MORE SPOTTY/LIGHT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...A SHORT WAVE TROUGH WILL SHIFT ACROSS THE LOWER
MISSISSIPPI VALLEY...WHILE AT THE SURFACE ADDITIONAL WAVES OF LOW
PRESSURE CONTINUE TO TRACK ALONG THE STALLED FRONT TO THE SOUTH
BEFORE MOVING OFF THE SOUTHEAST COAST. DEEP MOISTURE...INCREASED
FORCING FOR ASCENT WITH A PASSING DISTURBANCE ALOFT...AND
CONTINUED STRONG ISENTROPIC ASCENT AND THETA-E ADVECTION WILL
SUPPORT PERIODS OF RAIN THROUGH THE EVENING AND INTO THE OVERNIGHT
HOURS. THERE IS THEN SOME INDICATION THAT AN AREA OF WEAK
SUBSIDENCE COULD DEVELOP BEHIND THE PASSING DISTURBANCE /BUT AHEAD
OF THE MAIN SHORT WAVE TROUGH/ AND SOMEWHAT OF A DRY SLOT COULD
OVERSPREAD THE AREA LATE. GIVEN THIS POTENTIAL...THE FORECAST DOES
SHOW DECREASING RAIN CHANCES OVERNIGHT FROM THE WEST...WITH
PROBABILITIES FALLING INTO THE CHANCE CATEGORY ACROSS PORTIONS OF
INTERIOR SOUTHEAST GEORGIA LATE. TEMPERATURES SHOULD FALL TO LOWS
IN THE LOWER TO MID 50S ACROSS MUCH OF THE AREA.
MONDAY...LOW PRESSURE WILL CONTINUE TO PUSH OFFSHORE IN ACCORDANCE
WITH AN UPPER LEVEL TROUGH WHICH SHOULD BE NEAR THE COAST EARLY IN
THE EVENING. LOOKS LIKE A RATHER WET AND COOL DAY ACROSS THE AREA
GIVEN THE ABUNDANT MOISTURE/CLOUDS IN PLACE WITHIN THE HIGH PRESSURE
WEDGE PATTERN. TEMPS WILL LIKELY REMAIN IN THE 50S MOST LOCALES. IT
WILL ALSO BE BREEZY GIVEN THE TIGHT PRESSURE GRADIENT WITH SOME
GUSTS 25 TO POSSIBLY 30 MPH NEAR THE COAST...LIKELY STRONGEST OVER
SC. RAIN CHANCES LOWER TUESDAY NIGHT BUT THERE WILL STILL BE A FEW
SHOWERS AROUND GIVEN THE LINGERING LOW-LEVEL MOISTURE CONVERGENCE
AND WEAK SHORTWAVE ENERGY ALOFT.
TUESDAY...EXPECT SOME IMPROVEMENT AS LOW PRESSURE DEPARTS THE AREA
ALTHOUGH THE LATEST MODEL GUIDANCE SUGGEST SOME SHOWERS COULD
LINGER...AT LEAST NEAR THE COAST...AS A COASTAL TROUGH DEVELOPS.
TEMPS SHOULD GET INTO THE 60S MOST PLACES...ESPECIALLY GA.
WEDNESDAY...THE COASTAL TROUGH OFFSHORE LOOKS TO PUSH INLAND AND
NORTH OF THE AREA AS A WARM FRONT AS HIGH PRESSURE TO THE NORTH
MOVES FARTHER EAST. THIS WILL LEAD TO WARMER TEMPERATURES BACK INTO
THE 70S AWAY FROM THE COOLER COASTAL AREAS...AS WELL AS A FEW
SHOWERS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE OFFSHORE WILL MAINTAIN A WARMER THAN NORMAL PATTERN
INTO THURSDAY NIGHT BEFORE THE NEXT COLD FRONT PUSHES THROUGH...MOST
LIKELY EARLY FRIDAY. TEMPS COULD BE NEAR 80 THURSDAY WITH A FEW
SHOWERS AND THUNDERSTORMS AROUND...THEN WILL DROP BACK INTO THE 60S
FRIDAY WITH SOME MORE SHOWERS THANKS TO A STRONG UPPER TROUGH/JET
APPROACHING FROM THE WEST. THE COOLING TREND WILL CONTINUE OVER THE
UPCOMING WEEKEND AS THE TROUGH MOVES THROUGH WITH 30S POSSIBLE EACH
MORNING...ESPECIALLY SUNDAY WHEN FROST AND MAYBE EVEN FREEZE
CONDITIONS ARE POSSIBLE INLAND. THOSE WILL AGRICULTURAL INTERESTS
SHOULD CAREFULLY MONITOR TEMPERATURES THIS WEEKEND GIVEN THE
POTENTIAL IMPACT TO CROPS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR AND MVFR CONDITIONS HAVE LARGELY PERSISTED THROUGH THE LATE
MORNING AND EARLY AFTERNOON HOURS AT BOTH KSAV AND KCHS. EXPECT THIS
TREND TO CONTINUE THROUGH THE REST OF THE AFTERNOON AND INTO THE
EVENING DESPITE AN INCREASE IN RAINFALL COVERAGE AS THE MID-LEVELS
CONTINUE TO SATURATE AND THE INVERSION AROUND 900 MB CONTINUES TO
WEAKEN.
CEILINGS WILL LOWER THIS EVENING AND TONIGHT AS THE DYNAMIC CORE OF
THE LOW PRESSURE PASSES TO THE SOUTH ALONG THE GA/FL BORDER. EXPECT
LOWER CEILINGS AT KSAV THAN KCHS DUE TO THE CLOSER PROXIMITY TO THE
INSTABILITY. IFR CONDITIONS SHOULD BEGIN AT KSAV JUST BEFORE SUNSET
AND AT KCHS JUST AFTER SUNSET. KSAV SHOULD FURTHER DETERIORATE TO
LIFR AS THE LOW SLIDES OFF THE GA COAST OVERNIGHT. GREATEST FORECAST
CHALLENGE AT THIS POINT IS JUST HOW LOW THE CEILINGS WILL GO AT KSAV
DURING THE MONDAY EARLY MORNING HOURS AND HOW LOW THEY WILL STAY
LIFR.
A LOW LEVEL JET DEVELOPING AS THE LOW PASSES OFF OF THE CAROLINA
COAST MONDAY MORNING WILL BRING INCREASINGLY BREEZY CONDITIONS TO
KCHS. HAVE GUSTS BEGINNING AT 8Z. RELATIVELY DRIER AIR WILL COME IN
WITH THE JET...SIGNALING A DECREASE IN RAIN INTENSITY AND IMPROVING
CEILINGS BY MID-MORNING FOR KCHS...AND MIDDAY FOR KSAV.
EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR/IFR
CONDITIONS MONDAY-WEDNESDAY...ESPECIALLY AT KSAV...DUE TO LOW
CLOUDS AND RAIN. EXPECT BREEZY N/NE WINDS MONDAY.
&&
.MARINE...
WEBCAMS AND SURFACE DATA SUGGEST ANY SIGNIFICANT SEA FOG HAS
LIKELY DISSIPATED AND WITH NORTHEAST WINDS EXPECTED TO STRENGTHEN
THROUGH THE DAY...THE RISK FOR ADDITIONAL DEVELOPMENT IS LOW. THE
MARINE DENSE FOG ADVISORY WILL BE CANCELLED.
TODAY AND TONIGHT...LOW PRESSURE OFF THE SOUTHEAST COAST AND HIGH
PRESSURE TO THE NORTH WILL RESULT IN A STRENGTHENING NORTHEAST
FLOW ACROSS THE WATERS THROUGH TONIGHT. WIND AND WAVE CONDITIONS
WILL DETERIORATE...REACHING SMALL CRAFT ADVISORY CRITERIA ACROSS
THE CHARLESTON COUNTY NEAR SHORE WATERS BY THIS EVENING...THEN IN
THE FAR SOUTHERN SOUTH CAROLINA WATERS AND CHARLESTON HARBOR AFTER
MIDNIGHT. THERE IS A SMALL POTENTIAL THAT IF THE GRADIENT PINCHES
SUFFICIENTLY...THAT WIND GUSTS COULD APPROACH GALE FORCE LATE
TONIGHT OVER THE CHARLESTON COUNTY NEAR SHORE WATERS.
DESPITE LIMITED OBSERVED DATA...HIGH RESOLUTION MODELS CONTINUE TO
INDICATE SEA FOG PLAGUING PORTIONS OF THE NEAR SHORE WATERS SOUTH
OF EDISTO BEACH. IT VERY WELL COULD BE JUST LOW STRATUS...BUT
PREFER TO BE CAUTIOUS AND HAVE THEREFORE EXTENDED THE MARINE DENSE
FOG ADVISORY THROUGH NOON. IF THE FOG HAS NOT ERODED BY THAT
TIME...IT VERY WELL SHOULD THIS AFTERNOON GIVEN STRENGTHENING
WINDS.
MONDAY THROUGH FRIDAY...SOME DENSE FOG COULD OCCUR OVER THE COOL
NEARSHORE WATERS INTO EARLY MONDAY...MAINLY A RESULT OF LOWERING
STRATUS. OTHERWISE...EXPECT DETERIORATING CONDITIONS MONDAY WHEN THE
PRESSURE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE INLAND AND LOW
PRESSURE PASSING BY TO THE SOUTH. THIS WILL LIKELY RESULT IN
NORTHEAST WINDS REACHING CLOSE TO GALE FORCE AND SEAS BUILDING TO
AROUND 8 FT WHICH WOULD NECESSITATE SMALL CRAFT ADVISORIES AND
POSSIBLY EVEN GALE WARNINGS /ESPECIALLY OFF CHARLESTON COUNTY AND
THE GA WATERS BEYOND 20 NM/. FOR NOW WE HAVE ISSUED A GALE WATCH FOR
THE WATERS OFF CHARLESTON COUNTY WHERE CONFIDENCE IS GREATEST.
CONDITIONS WILL THEN IMPROVE LATER TUESDAY WITH ADVISORY-LEVEL SEAS
HANGING ON LONGER BEYOND 20 NM...LIKELY INTO THURSDAY. ANOTHER SURGE
EXPECTED LATER FRIDAY BEHIND A COLD FRONT BUT ADVISORIES ARE
UNLIKELY AT THIS POINT.
&&
.TIDES/COASTAL FLOODING...
ANOTHER ELEVATED HIGH TIDE WILL OCCUR LATE THIS EVENING WITH
SHALLOW COASTAL FLOODING LIKELY ALONG MUCH OF THE LOWER SOUTH
CAROLINA AND UPPER GEORGIA COASTS. ELEVATED TIDES COUPLED WITH
STRENGTHENING NORTHEAST WINDS WILL LIKELY PUSH TIDE LEVELS HIGHER
THAN WHAT WAS OBSERVED WITH HIGH TIDE YESTERDAY EVENING. A COASTAL
FLOOD ADVISORY WILL BE ISSUED FOR ALL COASTAL ZONES... INCLUDING
TIDAL BERKELEY...FROM 9PM-1AM TONIGHT. EXPECT TIDE LEVELS TO
POSSIBLY APPROACH MODERATE FLOOD THRESHOLDS AT THE CHARLESTON
HARBOR /7.5 FT MLLW/ GAGE...BUT REMAIN WELL WITHIN SHALLOW COASTAL
FLOODING THRESHOLDS AT FORT PULASKI. WILL FORECAST 7.3-7.5 FT MLLW
FOR CHARLESTON HARBOR AND 9.1-9.3 FT AT FORT PULASKI.
TIDES WILL REMAIN ELEVATED DUE TO THE RECENT NEW MOON AND
PERIGEE....ENHANCED BY STRENGTHENING NORTHEAST WINDS THROUGH
MONDAY. TIDE LEVELS COULD REACH COASTAL FLOOD ADVISORY CRITERIA
DURING THE EVENING HIGH TIDE CYCLES THROUGH MONDAY. WILL CONTINUE
TO MENTION THE POTENTIAL FOR SHALLOW SALTWATER INUNDATION AROUND
THE COAST IN THE HAZARDOUS WEATHER OUTLOOK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO 1 AM EDT
MONDAY FOR GAZ117-119-139-141.
SC...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO 1 AM EDT
MONDAY FOR SCZ048>052.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EDT TUESDAY
FOR AMZ352.
GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR
AMZ350.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 8 AM EDT MONDAY
FOR AMZ350.
SMALL CRAFT ADVISORY FROM 8 AM MONDAY TO NOON EDT TUESDAY FOR
AMZ354.
SMALL CRAFT ADVISORY FROM 8 AM MONDAY TO 4 AM EDT THURSDAY FOR
AMZ374.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EDT
MONDAY NIGHT FOR AMZ330.
&&
$$
ST/CEB
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
650 AM EDT SUN MAR 22 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE GULF COAST AND BRING
RAIN BACK TO THE AREA TODAY THROUGH MONDAY. COOLER TEMPERATURES
WILL OCCUR. SURFACE RIDGE TO THE NORTH AND A WEAK TROUGH ALONG THE
CAROLINA COAST WILL PERSIST THROUGH MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK SURFACE LOW DEVELOPING IN THE NORTHWEST GULF OF MEXICO.
RADAR AT 0730Z INDICATING LIGHT RAIN MOVING ACROSS THE SAVANNAH
RIVER INTO THE MIDLANDS FROM CENTRAL GEORGIA. LATEST HRRR RADAR
SIMULATION APPEARS TO HAVE A HANDLE ON PRECIPITATION TREND. HRRR
MODEL SPREADS LIGHT PRECIPITATION TO THE NORTH DURING THE MORNING
AS MOISTURE FLUX/ISENTROPIC LIFT INCREASES. BASED ON RADAR/MODEL
CONSENSUS...RAISED POPS ACROSS THE REGION. THE UPPER LEVEL TROUGH
OVER THE SOUTHERN PLAINS WILL CONTINUE TO TRACK TO THE NORTHEAST
TODAY...ACROSS THE MISSISSIPPI VALLEY THIS EVENING. INCREASING
ISENTROPIC LIFT THIS AFTERNOON AND THIS EVENING. PRECIPITABLE
WATER ABOVE CLIMATOLOGICAL MEAN WITH HIGHEST VALUES IN THE
CSRA...AROUND 1.3 INCHES. AS UPPER LEVEL LOW MOVES OVER THE REGION
TONIGHT...EXPECT STRONGEST LIFT DURING THIS TIME AND WILL MENTION
POSSIBLE MODERATE RAIN MAINLY SOUTHERN AREAS. A TIGHT
PRECIPITATION GRADIENT EXPECTED WITH STRONGEST 850MB CONVERGENCE
ACROSS SOUTHERN MIDLANDS. LIGHTER AMOUNTS ACROSS NORTH MIDLANDS.
WITH RAIN AND EXTENSIVE CLOUDS TEMPERATURES EXPECTED TO RISE A FEW
DEGREES FROM MORNING LOWS...SO LOW TO MID 60S APPEARS ON TRACK.
MOS CONSENSUS FOR MINIMUM TEMPERATURES HAS BEEN CONSISTENT AND
APPEARS ACCEPTED.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
COLD AIR DAMMING/WEDGE APPEARS LIKELY MONDAY WITH WEAK ISENTROPIC
LIFT/MOISTURE FLUX CONTINUING THROUGH AT LEAST 18Z. LIGHT
PRECIPITATION OR DRIZZLE MAY CONTINUE THROUGH AFTERNOON. RAISED
POPS ALL AREAS FROM PREVIOUS FORECAST. PREFER COOLER MAV GUIDANCE
WHICH IS IN LINE WITH THE SREF AND LOCAL WEDGE GUIDANCE...SO LOW
TO MID 50S WITH TEMPERATURES LIKELY FALLING THROUGH THE AFTERNOON
AS RIDGE STRENGTHENS TO THE NORTH. WEAK ONSHORE FLOW MAY CONTINUE
THROUGH TUESDAY...SO INCREASED CLOUDS WITH MODEST WARMING. SHOWERS
APPEAR POSSIBLE MAINLY CLOSER TO THE COAST SO FOR NOW WILL LEAVE
POPS BELOW 15 PERCENT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
GENERAL AGREEMENT CONTINUES IN THE EXTENDED FORECAST PERIOD WITH
THE OVERALL PATTERN...THOUGH THERE IS UNCERTAINTY LATE IN THE
FORECAST DUE TO TIMING AND STRENGTH DIFFERENCES ASSOCIATED WITH A
DEEP UPPER TROUGH DIGGING ACROSS THE MIDDLE PART OF THE COUNTRY.
FOR THE MOST PART...USED A BLEND OF GFS/PREVIOUS ECMWF/HPC GUIDANCE.
THERE IS UNCERTAINTY WITH POSSIBLE RAIN CHANCES WEDNESDAY AS A
WEAK INVERTED TROUGH MAY DEVELOP ALONG THE COAST WITH THE SURFACE
HIGH RETREATING IN ADVANCE OF THE NEXT STORM SYSTEM...ALTHOUGH THE
COOL WEDGE MAY BE STRONGER THAN FORECAST. A DIGGING TROUGH ACROSS
THE NORTHERN HALF OF THE COUNTRY THURSDAY INTO FRIDAY WILL RESULT
IN INCREASING MOISTURE IN DEVELOPING SOUTHWESTERLY FLOW AHEAD OF
AN APPROACHING COLD FRONT. FORECAST INSTABILITY OF LIFTED INDEX
VALUES AROUND MINUS 2 THURSDAY AFTERNOON WOULD SUPPORT AN ISOLATED
THUNDERSTORM THREAT. RAIN CHANCES CONTINUE INTO FRIDAY DUE TO
TIMING ISSUES BETWEEN THE MODELS. AT THIS TIME SATURDAY APPEARS
DRY WITH HIGH PRESSURE BUILDING IN FROM THE WEST. TEMPERATURES
GENERALLY BELOW NORMAL TUESDAY...AOA NORMAL WEDNESDAY THROUGH
FRIDAY...AND BELOW NORMAL SATURDAY.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
HIGH CONFIDENCE IN RESTRICTIONS BEGINNING OVER THE NEXT COUPLE OF
HOURS AND CONTINUING THROUGH THE END OF THE PERIOD.
RAIN CONTINUES TO SPREAD INTO THE TAF SITES WITH RESTRICTIONS
EXPECTED TO ARRIVE IN THE NEXT COUPLE OF HOURS. WSR-88D NETWORK
SHOWS LIGHT RAIN AROUND THE TAF SITES WITH HEAVIER RAIN ACROSS
CENTRAL AND SOUTHERN GA WHICH WILL MOVE INTO THE AREA LATER TODAY.
CONDITIONS WILL REMAIN LOW END MVFR TO IFR FROM THE LATE MORNING
THROUGH TONIGHT. LIFR CONDITIONS POSSIBLE AFTER 23/06Z...HOWEVER
CONFIDENCE TOO LOW TO INCLUDE IN TAFS ATTM. WINDS THROUGH THE
PERIOD WILL BE NORTHEASTERLY AT 7 KNOTS OR LESS.
EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN CIG/VSBY
RESTRICTIONS CONTINUING THROUGH MONDAY NIGHT IN WEDGE CONDITIONS.
THERE MAY BE ANOTHER CHANCE FOR RAIN AND ASSOCIATED RESTRICTIONS
TUESDAY NIGHT THROUGH THURSDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
400 AM EDT SUN MAR 22 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE GULF COAST AND BRING
RAIN BACK TO THE AREA TODAY THROUGH MONDAY. COOLER TEMPERATURES
WILL OCCUR. SURFACE RIDGE TO THE NORTH AND A WEAK TROUGH ALONG THE
CAROLINA COAST WILL PERSIST THROUGH MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK SURFACE LOW DEVELOPING IN THE NORTHWEST GULF OF MEXICO.
RADAR AT 0730Z INDICATING LIGHT RAIN MOVING ACROSS THE SAVANNAH
RIVER INTO THE MIDLANDS FROM CENTRAL GEORGIA. LATEST HRRR RADAR
SIMULATION APPEARS TO HAVE A HANDLE ON PRECIPITATION TREND. HRRR
MODEL SPREADS LIGHT PRECIPITATION TO THE NORTH DURING THE MORNING
AS MOISTURE FLUX/ISENTROPIC LIFT INCREASES. BASED ON RADAR/MODEL
CONSENSUS...RAISED POPS ACROSS THE REGION. THE UPPER LEVEL TROUGH
OVER THE SOUTHERN PLAINS WILL CONTINUE TO TRACK TO THE NORTHEAST
TODAY...ACROSS THE MISSISSIPPI VALLEY THIS EVENING. INCREASING
ISENTROPIC LIFT THIS AFTERNOON AND THIS EVENING. PRECIPITABLE
WATER ABOVE CLIMATOLOGICAL MEAN WITH HIGHEST VALUES IN THE
CSRA...AROUND 1.3 INCHES. AS UPPER LEVEL LOW MOVES OVER THE REGION
TONIGHT...EXPECT STRONGEST LIFT DURING THIS TIME AND WILL MENTION
POSSIBLE MODERATE RAIN MAINLY SOUTHERN AREAS. A TIGHT
PRECIPITATION GRADIENT EXPECTED WITH STRONGEST 850MB CONVERGENCE
ACROSS SOUTHERN MIDLANDS. LIGHTER AMOUNTS ACROSS NORTH MIDLANDS.
WITH RAIN AND EXTENSIVE CLOUDS TEMPERATURES EXPECTED TO RISE A FEW
DEGREES FROM MORNING LOWS...SO LOW TO MID 60S APPEARS ON TRACK.
MOS CONSENSUS FOR MINIMUM TEMPERATURES HAS BEEN CONSISTENT AND
APPEARS ACCEPTED.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
COLD AIR DAMMING/WEDGE APPEARS LIKELY MONDAY WITH WEAK ISENTROPIC
LIFT/MOISTURE FLUX CONTINUING THROUGH AT LEAST 18Z. LIGHT
PRECIPITATION OR DRIZZLE MAY CONTINUE THROUGH AFTERNOON. RAISED
POPS ALL AREAS FROM PREVIOUS FORECAST. PREFER COOLER MAV GUIDANCE
WHICH IS IN LINE WITH THE SREF AND LOCAL WEDGE GUIDANCE...SO LOW
TO MID 50S WITH TEMPERATURES LIKELY FALLING THROUGH THE AFTERNOON
AS RIDGE STRENGTHENS TO THE NORTH. WEAK ONSHORE FLOW MAY CONTINUE
THROUGH TUESDAY...SO INCREASED CLOUDS WITH MODEST WARMING. SHOWERS
APPEAR POSSIBLE MAINLY CLOSER TO THE COAST SO FOR NOW WILL LEAVE
POPS BELOW 15 PERCENT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
GENERAL AGREEMENT CONTINUES IN THE EXTENDED FORECAST PERIOD WITH
THE OVERALL PATTERN...THOUGH THERE IS UNCERTAINTY LATE IN THE
FORECAST DUE TO TIMING AND STRENGTH DIFFERENCES ASSOCIATED WITH A
DEEP UPPER TROUGH DIGGING ACROSS THE MIDDLE PART OF THE COUNTRY.
FOR THE MOST PART...USED A BLEND OF GFS/PREVIOUS ECMWF/HPC GUIDANCE.
THERE IS UNCERTAINTY WITH POSSIBLE RAIN CHANCES WEDNESDAY AS A
WEAK INVERTED TROUGH MAY DEVELOP ALONG THE COAST WITH THE SURFACE
HIGH RETREATING IN ADVANCE OF THE NEXT STORM SYSTEM...ALTHOUGH THE
COOL WEDGE MAY BE STRONGER THAN FORECAST. A DIGGING TROUGH ACROSS
THE NORTHERN HALF OF THE COUNTRY THURSDAY INTO FRIDAY WILL RESULT
IN INCREASING MOISTURE IN DEVELOPING SOUTHWESTERLY FLOW AHEAD OF
AN APPROACHING COLD FRONT. FORECAST INSTABILITY OF LIFTED INDEX
VALUES AROUND MINUS 2 THURSDAY AFTERNOON WOULD SUPPORT AN ISOLATED
THUNDERSTORM THREAT. RAIN CHANCES CONTINUE INTO FRIDAY DUE TO
TIMING ISSUES BETWEEN THE MODELS. AT THIS TIME SATURDAY APPEARS
DRY WITH HIGH PRESSURE BUILDING IN FROM THE WEST. TEMPERATURES
GENERALLY BELOW NORMAL TUESDAY...AOA NORMAL WEDNESDAY THROUGH
FRIDAY...AND BELOW NORMAL SATURDAY.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
HIGH CONFIDENCE IN RESTRICTIONS BEGINNING AROUND DAYBREAK AND
CONTINUING THROUGH THE END OF THE PERIOD.
FRONTAL BOUNDARY FROM THE GULF COAST THROUGH SOUTHEASTERN GA
CONTINUES TO MOVE NORTHWARD AND WILL SPREAD RAIN ACROSS THE TAF
SITES THROUGH THE DAY. REGIONAL WSR-88D NETWORK CURRENTLY SHOWS
RAIN MOVING THROUGH CENTRAL GA WITH SCATTERED RAIN ENTERING THE
AGS/DNL AREA. EXPECT RAIN TO MOVE INTO THE TAF SITES THROUGH
DAYBREAK ALONG WITH LOWERING CIGS AND VSBYS. EXPECT MVFR
CONDITIONS THROUGH MUCH OF THE DAY WITH CONDITIONS LOWERING TO IFR
FROM 23/00Z THROUGH THE END OF THE PERIOD. WINDS THROUGH THE
PERIOD WILL BE EASTERLY AT 7 KNOTS OR LESS.
EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN CIG/VSBY
RESTRICTIONS CONTINUING THROUGH MONDAY NIGHT IN WEDGE CONDITIONS.
THERE MAY BE ANOTHER CHANCE FOR RAIN AND ASSOCIATED RESTRICTIONS
TUESDAY NIGHT THROUGH THURSDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1005 PM CDT MON MAR 23 2015
.SHORT TERM...
326 PM CDT
THROUGH WEDNESDAY...
APOLOGIZE FOR THE DELAY IN AFD BUT SEVERAL TECHNICAL ISSUES
TODAY.
THE IMMEDIATE ATTENTION IN THE SHORT TERM IS DIRECTED TO CLOUD
COVER AND ITS RATE OF DISSIPATION...IF AT ALL...AND THE RESULTANT
IMPACT ON TEMPERATURES. SECOND AND LESS POTENT SHORT WAVE OVER
WESTERN WI WILL MOVE SOUTHEASTWARD TONIGHT...MAINLY NORTH OF THE
AREA FOR ANY FLURRIES. BEHIND THIS FEATURE...SUPPRESSION SHOULD
INCREASE OVER THE AREA. AMDAR DATA INDICATES THE SATURATED LAYER
IS STILL 3000-5000 FT DEEP SO DO NOT ENVISION THIS CLOUD LAYER
ERODING QUICKLY...BUT SHOULD MAKE SOME IMPROVEMENT FROM
NORTH/NORTHEAST TO THE SOUTHWEST GIVEN THE LOW-LEVEL
TRAJECTORIES.
WITH THE FRESH SNOW COVER AND THE CHALLENGES IN CLOUDS...THE
TEMPERATURE FORECAST FOR TONIGHT IS ONE THAT COULD HAVE QUITE A
SPREAD OVER THE AREA...AND THUS LOWERS CONFIDENCE FOR ANY ONE
SPECIFC LOCATION. HAVE LEANED TOWARD COOLER READINGS ACROSS THE
NORTHERN COUPLE TIERS OF COUNTIES...TOWARD THE UPPER TEENS AND LOW
20S...WHILE A SMART BLEND FOR THE SOUTH TOWARD UPPER 20S.
INEVITABLE TWEAKS WILL BE NEEDED TO HOURLY TRENDS AS CLOUD COVER /
CLEARING DICTATES.
ATTENTION THEN TURNS TO RAIN LIKELIHOOD TUESDAY NIGHT. OVERALL
THIS SYSTEM HAS TRENDED LESS AGGRESSIVE WITH EACH SUBSEQUENT RUN
OVER THE PAST 24 HOURS...LIKELY DUE IN PART TO MODEL ISSUES
HANDLING THE PHASING WITH AN UPPER LOW ACROSS THE FAR NORTHERN
PLAINS...AND POSSIBLY IN PART DUE TO THE RECENT SNOW COVER NOW
OVER THE AREA IMPACTING LOW-LEVEL BAROCLNICITY. THE OVERALL THEME
OF WIDESPREAD RAIN SHOWERS TUESDAY NIGHT STILL IS ON TRACK...AS
THE ELEVATED MOISTURE TRANSPORT REMAINS FOCUSED INTO THE AREA
DURING THAT PERIOD WITHIN UPPER LEVEL DIFLUENCE. DESPITE A LESS
IMPRESSIVE NEGATIVE TILT TO THE WAVE AS IT MOVES OVER...PROJECTED
LAPSE RATES ARE ENOUGH TO SUPPORT EMBEDDED THUNDER AND CONTINUE
THE CHANCES. RAINFALL AMOUNTS IN EXCESS OF ONE HALF INCH APPEAR
MOST FAVORED NORTH AND WEST OF INTERSTATE 55. FOR TEMPERATURES
TUESDAY NIGHT HAVE SLOWED THE DEGREE OF WARMING AND KEPT MORE
STEADY. STILL THE TEMPERATURES ARE MILD ENOUGH THAT FREEZING
PRECIP ISSUES SHOULD NOT BE A CONCERN AND REMAIN TO THE NORTH
INTO WISCONSIN.
WITH THE WEAKER SURFACE REFLECTION...WIND SPEEDS ON WEDNESDAY
PRESENTLY DO NOT LOOK AS IMPRESSIVE AS THEY HAD DUE TO LESS OF A
PRESSURE GRADIENT. ALSO TEMPERATURES WILL LIKELY NOT BE AS MILD
ACROSS THE NORTH WITH A FURTHER SOUTH PLACEMENT OF THE LOW AND
POTENTIALLY LINGERING STRATUS AS WELL. SO HAVE ADAPTED THOSE
TRENDS INTO THE FORECAST. STILL HAVE TEMPERATURES TOPPING 50
ACROSS MUCH OF THE AREA SOUTH OF INTERSTATE 88...BUT THE COOLING
TREND MAY CONTINUE.
&&
.LONG TERM...
326 PM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
POPS FOR WEDNESDAY NIGHT ACROSS THE SOUTHEAST FORECAST AREA HAVE
BEEN INCREASED AS THE SURFACE COLD FRONT COMES ACROSS OVER THE
REGION. WHILE THERE STILL IS A DECENT AMOUNT OF
UNCERTAINTY...GLOBAL GUIDANCE IS KEYING IN ON A MORE RAPIDLY
STRENGTHENING JET MAXIMA NEAR IN TANDEM TO THE FROPA...WITH THE
FAVORED ASCENT OVER THE CENTRAL IL TO NORTHERN/CENTRAL INDIANA
AREA FROM EVENING ON.
HAVE MADE LITTLE TO NO CHANGES TO THE GOING FORECAST AND A SMART
MODEL BLEND FOR LATE WEEK INTO THE WEEKEND. THIS STILL LOOKS
CONSIDERABLY COLD FOR THE TIME OF YEAR ON FRIDAY INTO
SATURDAY...WITH 850MB TEMPERATURES DROPPING TO THE LOWEST 2
PERCENTILE FOR THIS LATE IN MARCH. HAVE HIGHS ONLY AROUND FREEZING
ON FRIDAY WITH LOWS POTENTIALLY IN THE TEENS AREAWIDE ON FRIDAY
NIGHT IF CLEARING ALLOWS.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* EAST WINDS NEAR 10 KT DIMINISHING THIS EVENING.
* MVFR CIGS AROUND 1500 FT IMPROVE TO VFR LATE EVENING/OVERNIGHT.
* EAST-SOUTHEAST WINDS INCREASING TUESDAY...GUSTS AROUND 20 KT
LATER IN THE AFTERNOON/EVENING.
* RAIN DEVELOPING TUESDAY EVENING. CONDITIONS DETERIORATING TO
MVFR/IFR DURING THE EVENING. EMBEDDED THUNDERSTORMS POSSIBLE
OVERNIGHT.
* LLWS POTENTIAL TUESDAY NIGHT WITH WINDS AROUND 2000 FT AGL
INCREASING TO AROUND 50 KT FROM THE SOUTHEAST BY LATE EVENING.
RATZER
//DISCUSSION...UPDATED 00Z...
PRECIPITATION HAS MOVED WELL TO THE EAST/SOUTHEAST OF THE
TERMINALS LATE THIS AFTERNOON...WITH EXTENSIVE LINGERING MVFR
CLOUD DECK IN PLACE ACROSS THE AREA. SLOW DRYING FROM THE
NORTHEAST IS EXPECTED TO SLOWLY RAISE CEILINGS TO VFR AND
EVENTUALLY SCATTER LOW CLOUDS BY LATE EVENING. NEW SNOW COVER AND
CLEARING CLOUDS COULD RESULT IN SOME PATCHY MVFR VIS IN FOG MAINLY
FAR NORTHERN IL (RFD/DPA)...THOUGH CONFIDENCE LOW IN TIMING OF
CLEARING AND POTENTIAL FOG TREND. AREAS SOUTH OF RFD-DPA-ORD AREA
WILL BE SLOWER TO CLEAR OVERNIGHT.
ON TUESDAY WEAK HIGH PRESSURE SLIDES BY TO THE NORTHEAST AND
MAINTAINS RELATIVELY DRY EASTERLY LOW LEVEL FLOW ACROSS THE
REGION. AREA OF LOW PRESSURE AND WARM FRONT DOES LIFT TOWARD THE
AREA FROM THE MISSOURI VALLEY DURING THE AFTERNOON AND EVENING...
AND WILL EVENTUALLY RESULT IN LOWERING VFR CIGS AND INCREASING
EAST-SOUTHEAST WINDS THROUGH THE DAY. NEW SNOW COVER MAY HELP TO
LIMIT GUSTS SOMEWHAT...THOUGH GRADIENT TIGHTENS UP DURING THE
MID-LATE AFTERNOON HOURS WITH SOME GUSTINESS LIKELY. WINDS ABOVE
THE BOUNDARY LAYER INCREASE TO AROUND 50 KT AT 2000 FT FROM THE
SOUTHEAST TUESDAY EVENING...SETTING UP POTENTIAL LLWS.
RAIN LOOKS TO MOVE IN FROM THE SOUTH TOWARD EVENING...WITH FAIRLY
STEADY RAIN/SHOWERS RESULTING IN CIG/VIS LOWERING TO MVFR/IFR.
ELEVATED INSTABILITY WILL PRESENT A THREAT FOR EMBEDDED THUNDER
ESPECIALLY BEYOND 03-04Z AND OVERNIGHT AS UPPER DISTURBANCE
APPROACHES. TIMING/COVERAGE PRECLUDES MENTION IN LAST COUPLE OF
HOURS OF ORD 30 HOUR TAF AT THIS TIME...THOUGH COULD SEE ADDING
EVENING THUNDER IN FUTURE ISSUANCES AS TIMING BECOMES MORE
CERTAIN.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH IN WINDS THROUGH PERIOD.
* MEDIUM IN TIMING OF MVFR IMPROVEMENT LATER THIS EVENING AND RAIN
AND ASSOCIATED CIG/VIS TRENDS LATE TUESDAY.
* MEDIUM IN LLWS TUESDAY EVENING.
* LOW IN ANY FOG POTENTIAL OVERNIGHT...AND TIMING OF EMBEDDED TSRA
TUESDAY EVENING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...SLIGHT CHANCE OF SHOWERS WITH MVFR CIGS EARLY AM.
OTHERWISE PRIMARILY VFR. BREEZY SOUTHWEST WINDS.
THURSDAY...SLIGHT CHANCE OF SHOWERS. MVFR POSSIBLE.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW EARLY. OTHERWISE PRIMARILY
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE OF RAIN. PATCHY MVFR POSSIBLE.
RATZER
&&
.MARINE...
212 PM CDT
HIGH PRESSURE CENTERED OVER EAST-CENTRAL ONTARIO WILL MOVE
SOUTHEAST INTO NEW ENGLAND BY TUESDAY EVENING. THIS WILL ALLOW
EASTERLY WINDS TO SHIFT SOUTHEASTERLY THROUGH THE DAY TUESDAY. LOW
PRESSURE WILL DEVELOP IN THE LEE OF THE ROCKIES THROUGH THE DAY
TUESDAY IN RESPONSE TO AN UPPER LEVEL TROUGH WORKING EASTWARD. ONE
SURFACE LOW WILL CONSOLIDATE ACROSS THE DAKOTAS THEN BE KICKED
EASTWARD BY A SECOND UPPER TROUGH WEDNESDAY. OF MORE IMMEDIATE
NOTE IS THE SURFACE LOW THAT WILL DEVELOP ACROSS THE MID
MISSISSIPPI RIVER VALLEY AND TRACK NORTHEAST FROM THERE LATE
TUESDAY. GUIDANCE HAS STRUGGLED WITH THE STRENGTH AND TRACK OF
THIS LOW WITH MORE OF A SOUTHWARD TRACK FAVORED WHICH TAKES THE
LOW ACROSS SOUTHERN LAKE MICHIGAN. WITH SEVERAL FEATURES IN PLAY
IN TERMS OF THE DEVELOPMENT OF THIS SYSTEM WOULD NOT BE SURPRISED
TO SEE FURTHER FLUCTUATIONS IN THE TRACK/STRENGTH YET TONIGHT AND
TUESDAY MORNING. ALL OF THE ABOVE POINTS TO WINDS THAT ARE NOT AS
STRONG AS THEY APPEARED FOR LAND AND NEARSHORE AREAS...BUT OPEN
WATER AREAS STILL LOOK TO PUSH 30 KT AT TIMES LATE TUESDAY NIGHT
AND WEDNESDAY MORNING...WITH THE STABLE LAYER LIMITING WINDS MUCH
HIGHER THAN THAT SHOULD THE LOW END UP BEING STRONGER. WINDS WILL
BE EASTERLY NORTH OF THE TRACK AND SOUTHERLY SOUTH OF IT WITH A
MORE UNIFORM SOUTHWESTERLY WIND BEHIND THE LOW FOR MUCH OF
WEDNESDAY. THE DAKOTAS LOW WEAKENS AND MOVES ACROSS UPPER MICHIGAN
AND NORTHERN LAKE MICHIGAN WEDNESDAY EVENING WHILE A COLD FRONT
SWEEPS DOWN THE LAKE TURNING WINDS WEST TO NORTHWEST. A STEADY
PRESSURE GRADIENT WILL REMAIN ACROSS THE LAKE THURSDAY AHEAD OF
HIGH PRESSURE WHICH WILL MOVE FROM CENTRAL CANADA TO THE UPPER
MISSISSIPPI RIVER VALLEY BY FRIDAY AND ACROSS THE WESTERN LAKES
FRIDAY NIGHT. BREEZY NORTH TO NORTHWEST WINDS WILL GRADUALLY
DIMINISH DURING THIS TIME. LOW PRESSURE IS THEN EXPECTED TO TRACK
NORTH OF THE AREA EARLY SUNDAY WITH BREEZY SOUTHWEST WINDS
DEVELOPING AHEAD OF IT SHIFTING NORTHWEST AS ANOTHER HIGH MOVES
INTO THE PLAINS MONDAY.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
844 PM CDT Mon Mar 23 2015
.UPDATE...
ISSUED AT 830 PM CDT MON MAR 23 2015
Main concern late tonight thru the mid morning hours of Tuesday
will be the threat for a brief period of freezing rain over
parts of west central and central IL. Shortwave that produced
the period of sleet and freezing rain over our far northern
counties early this morning has pushed well to our east this
evening with weak high pressure moving across the area in its
wake. Meanwhile, our next weather system is taking shape over
the Central Plains with elevated convection already developing
in the warm advection pattern ahead of the strong upper wave.
That upper wave and the developing precip will shift east tonight
and approach our area in the 11z-14z time frame and based on the
last several runs of the RAP, it appears there will be a brief
period of light freezing rain across west central IL extending
into parts of central IL thru mid morning.
Will be making some adjustments to the coverage of the light
freezing rain late tonight over extreme western IL and shift the
threat into central IL during the 12z-15z time frame. Have also
adjusted the temps down a few degrees, especially across the
north for late tonight and thru the mid morning hours of Tuesday.
The rest of the forecast looks on target. The ZFP update should
be out by 900 pm.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 346 PM CDT MON MAR 23 2015
PRECIPITATION ASSOCIATED WITH TODAY`S SHORTWAVE HAS EXITED TO
THE EAST. LOW LEVEL CLOUD COVER REMAINS IN ITS WAKE. STRONG
HIGH PRESSURE REMAINS IN PLACE ACROSS THE EASTERN GREAT LAKES
WHICH TENDS TO SUGGEST THAT THE CLOUDS WILL LINGER MUCH OF THE
NIGHT IN SPITE OF SOME POTENTIAL CLEARING TO THE SOUTH. WITH THE
HIGH IN PLACE TONIGHT...LOW LEVEL DRY ENE FLOW WILL KEEP A COOL
LOW LEVEL AIR MASS IN PLACE.
ATTENTION SHIFTS TO THE UPPER TROUGH ENTERING THE SOUTHERN ROCKIES.
THERE WILL BE SOME LEAD SHORTWAVE ENERGY PUSHING EAST THROUGH
THE CENTRAL PLAINS AND MID MISSOURI VALLEY TONIGHT. STRONG LOW LEVEL
WARM ADVECTION/ISENTROPIC LIFT INTO THE LOW-MID LEVEL FRONTAL ZONE
WILL RESULT IN SHOWERS TO MOVE INTO ILLINOIS LATE TONIGHT INTO
TOMORROW MORNING. THERE IS SOME WEAK INSTABILITY ABOVE 700-600 MB
AS THESE SHOWERS ROLL IN WHICH MAY RESULT IN A FEW EMBEDDED
THUNDERSTORMS...ESPECIALLY SOUTH OF I-72. MEANWHILE NORTH OF
I-74 AND CLOSER TO I-72...SURFACE TEMPERATURES LOOK TO DIP BELOW
FREEZING TONIGHT INTO EARLY TUESDAY MORNING. THEREFORE RAIN/FREEZING
RAIN CONCERNS COME INTO PLAY. CONFIDENCE IS NOT SUPER HIGH ON ICE
ACCUMULATIONS GIVEN THE WARMER GROUND CONDITIONS...BUT IT IS
CERTAINLY CONCERN EAST OF I-55 WHERE PRECIPITATION HAS A BETTER
CHANCE OF COMING IN DURING THE COOL HOURS OF THE NIGHT AND EARLY
MORNING. BY MID-LATE MORNING THE LOWER LEVEL WARMING WILL ALLOW
SURFACE TEMPS TO BE ABOVE FREEZING AREA-WIDE.
THERE MAY BE A LULL IN THE SHOWER ACTIVITY IN AFTERNOON AS THE
MID LEVEL BAROCLINIC ZONE SHIFTS NORTH AND THE LEAD WAVES MOVES
EASTWARD. THE SURFACE WARM FRONT WILL EVENTUALLY MOVE NORTH THROUGH
THE CWA DURING THE AFTERNOON AND MORE SO THE EVENING HOURS.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 346 PM CDT
MON MAR 23 2015
THE CENTER OF LOW PRESSURE LIFTING OUT OF THE SOUTHERN PLAINS
WILL CROSS THE LOCAL AREA TUESDAY NIGHT AND QUICKLY PUSH WELL TO
THE NORTHEAST BY NOON WEDNESDAY. UNCERTAINTY IN THE EXACT TRACK OF
THE LOW WILL CREATE CHALLENGES FOR LOW TEMPERATURE FORECASTS AND
THE NORTHERN EXTENT OF THUNDERSTORM ACTIVITY...WITH THE BEST
CHANCE OF THUNDER BEING IN THE TUESDAY EVENING HOURS AS THE LOW
CENTER AND UPPER TROUGH AXIS MOVE OVERHEAD.
AFTER A BRIEF DRY PERIOD WEDNESDAY...AND AT LEAST PART OF
WEDNESDAY AFTERNOON...ANOTHER WEAKER DISTURBANCE WEDNESDAY
NIGHT FOLLOWS QUICKLY ON THE HEELS OF THE TUESDAY NIGHT SYSTEM.
THIS TOO SHOULD QUICKLY CLEAR TO THE EAST AFTER DAYBREAK THURSDAY.
WITH THE PASSAGE OF THE FRONTAL ZONE ASSOCIATED WITH THE SECOND
SYSTEM...COOLER AIR SETTLES INTO THE AREA UNDER A BROAD DOME OF
HIGH PRESSURE FOR THE REMAINDER OF THE WEEK AND EARLY WEEKEND. BY
LATE SUNDAY THE DOMINANT AREA OF COOL HIGH PRESSURE SLIDES INTO THE
SOUTHEAST CONUS ALLOWING MILDER AND MORE HUMID RETURN FLOW TO BEGIN
WORKING BACK INTO THE MIDWEST. WITH THE RETURN OF HIGHS IN THE 50S
OR WARMER COMES INCREASED CHANCES OF PRECIPITATION FOR LATE IN THE
WEEKEND...BUT AT THIS RANGE AM ONLY CONFIDENT ENOUGH ON TIMING AND
EXTENT TO INCLUDE CHANCE POPS.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 620 PM CDT MON MAR 23 2015
Our next weather system is expected to bring deteriorating conditions
once again late tonight and especially during the morning. Low VFR
to MVFR cigs dominate the area and expect most of our TAF sites to
be MVFR by 04z and continue into tomorrow morning with precip
developing across west central IL by dawn. Main forecast concern
tomorrow morning will be with precip type as a few models suggest the
threat for a period of freezing rain across PIA and BMI. Last several
runs of the RAP forecast soundings suggest precip will be slower to
arrive than originally thought as drier air in the low and mid levels
impedes the initial surge of rain. However, by late morning in most
areas, we should see the rain overspread the forecasts sites with
cigs lowering to IFR by afternoon. Surface winds will be northeast to
east tonight at 10 to 15 kts and mostly out of the east on Tuesday
at 10 to 15 kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...KMD
LONG TERM...LENNING
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
250 PM CDT SUN MAR 22 2015
.UPDATE...1025 AM CDT
ONLY SMALL CHANGES MADE TO THE FORECAST FOR THIS AFTERNOON.
HAVE ADDED THE MENTION OF SOME FLURRIES OR POSSIBLY SPRINKLES
THIS AFTERNOON IN FAR NORTHERN ILLINOIS...BUT AS FOR THIS
EVENING CONTINUE TO DELAY MENTION OF MEASURABLE PRECIPITATION
CHANCES.
A CANOPY OF MID-LEVEL CLOUDS FROM SOUTHERN/CENTRAL MN THROUGH
FAR NORTHERN IL AND SOUTHERN LAKE MI HIGHLIGHTS A WEAK ZONE OF
MID-LEVEL FORCING ALONG A MODEST THERMAL GRADIENT. THE NATURE
OF SOME OF THE SOUTHERN EDGE CLOUDS AS WELL AS 35-40DBZ ECHOES
ON COMPOSITE RADAR NEAR THE IA/MN BORDER INDICATE THE PRESENCE
OF AT LEAST WEAK INSTABILITY ALOFT AND LIKELY THE RESULT OF A
SUBTLE MID-LEVEL PERTURBATION PER SATELLITE AND RAP ANALYSIS.
IT IS POSSIBLE AS THIS CORRIDOR OF SHOWERY-TYPE ECHOES BRINGS
SOME SPRINKLES OR FLURRIES TO FAR NORTHERN IL EARLY TO MID
AFTERNOON...SO THAT IS WHY THE EARLIER MENTION IN THE
FORECAST. OVERALL THOUGH...THE DRIER SYNOPTIC AIR AND DRY
925-850MB TRAJECTORIES WILL LIKELY PREVENT ANY NOTEWORTHY PRECIP
INTO THIS EVE AND POSSIBLY THROUGH EARLY OVERNIGHT UNTIL STRONGER
FORCING WITH THE MAIN UPPER SHORT WAVE APPROACH.
THE CHALLENGE WITH THIS UPCOMING SNOW EVENT LOOKS TO BE IF THERE
WILL BE A CORRIDOR/BAND OF MODERATE SNOWFALL RATES DURING THE
DAYBREAK THROUGH MID-MORNING HOURS ON MONDAY...WHICH SOME HIGH
RESOLUTION MODELS INCLUDING THE 12Z NAM INDICATE AND THIS MAKES
SENSE SOMEWHERE IN THE REGION WITH THIS TYPE OF SYSTEM. IT IS
JUST PLACEMENT AND DURATION IS THE CHALLENGE. THESE MORE
APPRECIABLE RATES EVEN IF TEMPORARY WOULD HAVE AT LEAST A
SLIGHTLY GREATER IMPACT DUE TO OVERCOMING THE NOW WARMER PAVEMENT
AND GROUND TEMPERATURES. WILL CONTINUE TO LOOK AT GUIDANCE AND
REFINE THE FORECAST WITH MORE TEMPORAL AND SPATIAL RESOLUTION FOR
MONDAY MORNING AND IF NEEDED ISSUE SOME FORM OF STATEMENT TO
FURTHER HIGHLIGHT.
MTF
&&
.SHORT TERM...
235 AM CDT
THROUGH MONDAY...
MAIN CONCERN IN THE SHORT TERM WILL REVOLVE AROUND TIMING OF A
DEVELOPING MID-LVL SHORTWAVE FOR LATE TONIGHT INTO MONDAY
MORNING...WHICH WILL LIKELY BRING SOME LIGHT ACCUMULATING SNOWFALL
TO MAINLY NORTHERN IL. PRIOR TO THE ARRIVAL OF THIS SYSTEM...EARLY
THIS MORNING THE SURFACE ANTI-CYCLONIC FEATURE REMAINED CENTERED
OVER THE GREAT LAKES REGION. THIS FEATURE WAS SENDING MUCH DRIER AIR
SOUTH ACROSS THE WESTERN GREAT LAKES WITH NUMEROUS LOCATIONS IN WISC
SEEING DEW PTS IN THE SINGLE DIGITS TO LOW TEENS...ALTHOUGH ACROSS
NORTHERN IL DEW PTS REMAINED IN THE LOW/MID 20S. THIS WAS A RESULT
OF THE NORTHEAST WINDS ALLOWING THE MARINE ENVIRONMENT TO BLEED
INLAND.
GUIDANCE CONTINUES TO SUGGEST THE SFC RIDGE WILL REMAIN ORIENTED
ACROSS THE UPPER MIDWEST/GREAT LAKES STRETCHING NORTH INTO CENTRAL
ONTARIO THROUGH TONIGHT AND INTO MONDAY. THIS WILL MAINTAIN A
COOL/DRY NORTHEAST TO EAST LLVL FLOW ACROSS THE FORECAST AREA. IR
IMAGERY INDICATES A THIN CIRRUS SHIELD OVERHEAD...BUT WILL STEADILY
THICKEN AS THE AFTN/EVE PROGRESSES. HIGHS TODAY WILL STRUGGLE TO
WARM BEYOND THE LOW/MID 40S...WITH A FEW AREAS IN THE FAR SOUTHWEST
NEARING 50. AREAS ADJACENT TO LAKE MICHIGAN WILL BE UNDER THE
INFLUENCE OF A COLD MARINE ENVIRONMENT...LIKELY HOLDING TEMPS IN THE
UPR 30S WITHIN THE FIRST FEW MILES OF LAND AWAY FROM THE LAKE.
THE FOR TONIGHT...GUIDANCE HAS LOCKED IN THE DRY AIR WHICH APPEARS
TO BE DELAYING THE MOISTENING LOW/MID LVLS UNTIL LATE TONIGHT. USING
A T-LAG DISPLAY OF SOUNDINGS WOULD SUGGEST THE TREND HAS BEEN TO
PUSH BACK PRECIP UNTIL ARND 6Z BUT THAT TOO COULD BE A FEW HOURS
EARLY. HAVE HELD ONTO DRY CONDS LONGER WITH SLT CHC POPS ARRIVING
ARND 6Z...THEN STEADILY INCREASING TO LIKELY ARND 9Z THRU ABOUT 12-
14Z. A BAROCLINIC ZONE WILL BE ORIENTED FROM SOUTHEAST IOWA EAST
THROUGH CENTRAL IL INTO CENTRAL IN BY EARLY MON AFTN. THE LOW WILL
LIKELY FOLLO THIS ORIENTATION AS IT NEARS THE REGION LATE TONIGHT.
THERE CONTINUES TO BE SOME DEGREE OF UNCERTAINTY ON THE DURATION OF
THE SNOW...HOWEVER DYNAMICALLY SPEAKING THE FORCING CRANKS UP LATE
TONIGHT WITH STEEPING MID-LVL LAPSE RATES AND A TIGHTENING GRADIENT
ALONG THE BAROCLINIC ZONE. WITH STRONG ASCENT ALONG THE LEADING
EDGE...QUICK MOISTENING OF THE LLVLS SHUD OCCUR AND MAY ALLOW FOR A
FEW HRS OF MODERATE SNOW BETWEEN 10-14Z...BEFORE THE PROFILE BEGINS
TO WARM AND LIFT BEGINS TO DECREASE BY 15-17Z MON. SNOW ACCUMS ARE
POSSIBLE AND TIMING APPEARS TO BE JUST PRIOR TO RUSH-HOUR MON
MORNING...AND ENDING SHORTLY AFTER. CURRENT INDICATIONS ARE FOR ARND
1 INCH CLOSER TO CHICAGO...AND POSSIBLY UP TO 2 INCHES IN A FEW
AREAS ALONG AND WEST OF A DIXON TO CRYSTAL LAKE LINE. THICK SOLAR
SHIELDING WILL KEEP TEMPS WELL BELOW SEASONAL CONDS MON...WITH HIGHS
MAINLY IN THE MID/UPR 30S. PRECIP SHUD BE ENDING BY EARLY AFTN MON.
BEACHLER
&&
.LONG TERM...
354 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
ATTENTION DURING THE LONG TERM PERIOD IS MAINLY FOCUSED ON THE
POTENTIAL FOR A GOOD STORM SYSTEM TO IMPACT THE REGION LATE TUESDAY
THROUGH WEDNESDAY.
MODEL GUIDANCE CONTINUES IN DECENT AGREEMENT WITH THE EVOLUTION OF A
STORM SYSTEM ACROSS THE CENTRAL PORTION OF THE COUNTRY BY MID WEEK.
UPPER LEVEL ENERGY EMANATING FROM THE NORTHEASTERN PACIFIC IS
EXPECTED TO SHIFT EASTWARD ONSHORE ACROSS THE PACIFIC NORTHWEST BY
MONDAY...THEN OVER THE ROCKIES BY TUESDAY MORNING. THIS SHOULD SPAWN
SURFACE LOW PRESSURE OVER THE PLAINS DURING THE DAY TUESDAY. MODEL
GUIDANCE IS ALSO INSISTENT THAT THE MAIN MID/UPPER LEVEL SHORT WAVE
WILL BECOME NEGATIVELY TILTED AS IT MOVES OVER THE MID MISSOURI
VALLEY LATE TUESDAY INTO TUESDAY NIGHT. AS SUCH...THIS IS SHAPING UP
TO POSSIBLY BE A GOOD DYNAMIC SYSTEM CAPABLE OF PRODUCING
THUNDERSTORMS OVER THE AREA...ESPECIALLY TUESDAY NIGHT...FOLLOWED BY
SOME STRONG SYNOPIC WINDS INTO WEDNESDAY.
IT CURRENTLY APPEARS THAT MOST OF NORTHERN ILLINOIS/NORTHWESTERN
INDIANA MAY END UP STAYING DRY FOR MOST OF THE DAY TUESDAY AS MOST
OF THE SHOWERS LOOK TO REMAIN FOCUSED DOWN STATE IN CLOSER PROXIMITY
TO THE WARM FRONTAL BOUNDARY. FOR THIS REASON I HAVE CUT BACK ON
POPS ACROSS NORTHERN ILLINOIS DURING THE DAY TUESDAY. THE BEST
POTENTIAL FOR SHOWERS AND THUNDERSTORMS FOR THE AREA LOOKS TO BE
TUESDAY EVENING AND INTO THE PREDAWN HOURS OF OF WEDNESDAY MORNING.
THIS IS THE PERIOD WHEN THE MAIN MID LEVEL NEGATIVELY TILTED SYSTEM
BEGINS TO SHIFT OVER NORTHERN ILLINOIS. AS THIS OCCURS...THE SURFACE
LOW WILL ACCELERATE NORTHEASTWARD AND DEEPEN INTO WEDNESDAY. THIS
WILL RAPIDLY SHIFT THE WARM FRONT AND BETTER MOISTURE FROM DOWNSTATE
ILLINOIS RIGHT ACROSS THE AREA BY TUESDAY EVENING.
THINGS LOOK TO DRY OUT IN A HURRY BY EARLY WEDNESDAY FOLLOWING THE
PASSAGE OF THE MID LEVEL SYSTEM AND DRY PUNCH. THE MAIN WEATHER
ISSUE ON WEDNESDAY WILL BE THE POTENTIAL FOR STRONG WEST-
SOUTHWESTERLY WINDS. IT CURRENTLY APPEARS THAT WINDS COULD GUST TO
AROUND 40 TO 45 MPH ON WEDNESDAY AS THE COMBINATION OF MUCH DRIER
AIR...GOOD LARGE SCALE DECENT IN THE WAKE OF THE UPPER LEVEL SYSTEM
AND SOME DECENT SURFACE PRESSURE RISES...COULD LEAD TO EFFICIENT
ATMOSPHERIC MIXING OF STRONG WINDS OFF THE SURFACE.
MID/UPPER LEVEL HEIGHTS ARE EXPECTED TO BUILD ACROSS WESTERN NORTH
AMERICA BY MID WEEK...AND THIS WILL ULTIMATELY SET UP TROUGHING OVER
THE EASTERN CONUS...FEATURING NORTHWEST FLOW ALOFT OVER THE
WESTERN GREAT LAKES REGION. THEREFORE...MILD CONDITIONS TUESDAY
NIGHT AND WEDNESDAY WILL TRANSITION TO COLDER WEATHER AGAIN BY
THURSDAY AS THIS PATTERN ALLOWS MUCH COLDER AIR TO SPILL IN ACROSS
THE EASTERN CONUS FOR THE LATER HALF OF THE WEEK. HIGHS WILL
LIKELY END UP 10 TO 15 DEGREES BELOW AVERAGE FOR A FEW DAYS AT THE
END OF THE PERIOD (30S TO LOW 40S). IT ALSO APPEARS THAT THERE
COULD BE SOME PERIODIC EPISODES OF SNOW AND RAIN SHOWERS AS
ADDITIONAL MID LEVEL DISTURBANCES SHIFT SOUTHEASTWARD ACROSS THE
REGION.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* EAST/NORTHEAST WINDS 10-15KT WITH HIGHER GUSTS POSSIBLE THIS
AFTERNOON AND TONIGHT.
* CHANCE OF FLURRIES/SPRINKLES THIS AFTERNOON/EVENING.
* SNOW DEVELOPING 09Z-11Z WITH IFR CONDITIONS EXPECTED 12Z-17Z.
* SNOW MIXING WITH/CHANGING TO LIGHT FREEZING DRIZZLE/LIGHT RAIN
LATE MONDAY MORNING...THEN ENDING EARLY MONDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 18Z...
MID CLOUDS WILL CONTINUE TO SPREAD SOUTHEAST ACROSS THE AREA THIS
AFTERNOON AND THIS EVENING. RADAR ECHOS SUGGEST THIS MID DECK HAS
EXTENSIVE VIRGA...PRECIPIATION ALOFT...WITH VERY LITTLE REACHING
THE GROUND. ORD NOW REPORTING FLURRIES AND SOME FLURRIES OR
SPRINKLES ARE POSSIBLE BUT NOT EXPECTING ANY RESTRICTIONS TO VIS
OR CIGS. FURTHER NORTHWEST AT RFD...LOW LEVELS WILL LIKELY
SATURATE SOONER AND DID INCLUDE A MENTION OF VFR SPRINKLES/
FLURRIES THIS AFTERNOON.
AS AN UPPER WAVE MOVES ACROSS THE AREA MONDAY MORNING...SNOW IS
EXPECTED TO DEVELOP. AT FIRST IT MAY BE MAINLY ACROSS SOUTHERN WI
AND FAR NORTHERN IL BEFORE EXPANDING/DEVELOPING ACROSS THE ENTIRE
AREA AROUND/JUST PRIOR TO DAYBREAK. THUS CONFIDENCE REGARDING
SPECIFIC START TIMES AND THE ASSOCIATED VIS/CIGS IS LOW. BUT
EVENTUALLY...09Z-10Z AT RFD AND 12Z-13Z AT ORD/MDW...GUIDANCE
SUGGESTS A 3-6 HOUR PERIOD OF PREVAILING SNOW...POSSIBLY MODERATE
SNOW. SO CONFIDENCE OF THE OVERALL TREND IS MEDIUM TO HIGH. THIS
SHOULD ALLOW CIGS/VIS TO DROP TO IFR AND LIFR VIS IS ALSO
POSSIBLE. PRECIP END TIME APPEARS TO BE IN THE 17Z-19Z TIME FRAME
AS PRECIP SHIFTS SOUTHEAST AND THE SYSTEM BEGINS TO WEAKEN. BUT
PRECIP TYPE DURING THIS TIME IS UNCERTAIN. PRECIP COULD MIX WITH
FREEZING DRIZZLE AND THEN POSSIBLY END AS DRIZZLE/LIGHT RAIN.
EASTERLY WINDS HAVE BEEN PREVAILING 10-15KTS ALL MORNING AND
LITTLE CHANGE IS EXPECTED INTO THIS EVENING WITH SOME HIGHER
GUSTS POSSIBLE. WINDS WILL REMAIN EASTERLY INTO MONDAY MORNING
WITH SPEEDS LIKELY AROUND OR JUST ABOVE 10KT. CMS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH FOR WINDS THRU THE PERIOD.
* MEDIUM FOR FLURRIES/SPRINKLES THIS AFTERNOON.
* HIGH FOR SNOW MONDAY MORNING...MEDIUM FOR ASSOCIATED CIGS/VIS
AND MEDIUM FOR START/END TIMES. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MAINLY VFR CONDS. PATCHY MVFR CIGS.
TUESDAY...CHANCE OF RAIN TUESDAY AFTERNOON. RAIN LIKELY/THUNDER
POSSIBLE AT NIGHT. MVFR/IFR POSSIBLE. BREEZY SOUTHEAST WINDS.
WEDNESDAY...SLIGHT CHANCE OF SHOWERS WITH MVFR EARLY. GUSTY WEST-
SOUTHWEST WINDS.
THURSDAY...SLIGHT CHANCE OF SHOWERS. MVFR POSSIBLE.
FRIDAY...VFR.
SATURDAY...VFR.
BEACHLER
&&
.MARINE...
248 PM CDT
A HIGH PRESSURE RIDGE EXTENDS FROM NORTHERN
MANITOBA AND ONTARIO TO THE LOWER GREAT LAKES LATE THIS AFTERNOON.
NORTHEASTERLY WINDS WILL BE IN PLACE TONIGHT AND STEADILY TURN
EASTERLY MONDAY MORNING AS THE CENTER OF THE HIGH MOVES TO NORTHERN
LAKE HURON. THE HIGH WILL CONTINUE TO THE EAST ALLOWING WINDS TO
TURN SOUTHEASTERLY INTO MONDAY NIGHT. ATTENTION TURNS TO LOW
PRESSURE THAT WILL BE DEVELOPING IN THE LEE OF THE ROCKIES MONDAY
NIGHT THEN CONSOLIDATE AND STRENGTHEN ACROSS THE SOUTHERN PLAINS
TUESDAY EVENING. THE LOW WILL THEN LIFT NORTHEAST ACROSS EASTERN
IOWA AND THEN NORTHERN LAKE MICHIGAN INTO WEDNESDAY AFTERNOON WHILE
MAINTAINING STRENGTH. SOUTH TO SOUTHEAST WINDS WILL INCREASE TUESDAY
NIGHT...WITH A MORE DUE EAST DIRECTION ACROSS THE NORTH. WINDS WILL
FLIP SOUTHWEST SOUTH OF THE LOW TRACK AND REMAIN EAST TO NORTHEAST
TO THE NORTH ON WEDNESDAY. WARMER AIR WILL BE BUILDING IN SO A SHARP
STABLE LAYER WILL DEVELOP LIMITING WIND GUST POTENTIAL. STILL EXPECT
30 KT ON THE OPEN WATERS BUT WITH MIXING SPREADING OFFSHORE
NEARSHORE AREAS COULD EASILY SEE MID TO HIGH END GALES. THINGS
SETTLE DOWN WEDNESDAY NIGHT WHILE ANOTHER WEAKER LOW MOVES UP THE
OHIO VALLEY BUT STRONG HIGH PRESSURE WILL BUILD IN BEHIND IT. THIS
WILL BRING A SHIFT TO NORTH TO NORTHWEST WINDS ACROSS THE LAKE
THURSDAY WITH COLDER AIR ALLOWING MIXING TO DEEPEN AND BRINGING THE
POTENTIAL FOR A PERIOD OF LOWER END GALES. THE HIGH WILL MOVE
SOUTHWARD INTO THE PLAINS KEEPING WINDS NORTHERLY BUT ALLOWING
SPEEDS TO SLACKEN THROUGH THE END OF THE WEEK AND INTO THE WEEKEND.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008...3 AM MONDAY TO
NOON MONDAY.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
104 PM CDT SUN MAR 22 2015
.UPDATE...
1025 AM CDT
ONLY SMALL CHANGES MADE TO THE FORECAST FOR THIS AFTERNOON.
HAVE ADDED THE MENTION OF SOME FLURRIES OR POSSIBLY SPRINKLES
THIS AFTERNOON IN FAR NORTHERN ILLINOIS...BUT AS FOR THIS
EVENING CONTINUE TO DELAY MENTION OF MEASURABLE PRECIPITATION
CHANCES.
A CANOPY OF MID-LEVEL CLOUDS FROM SOUTHERN/CENTRAL MN THROUGH
FAR NORTHERN IL AND SOUTHERN LAKE MI HIGHLIGHTS A WEAK ZONE OF
MID-LEVEL FORCING ALONG A MODEST THERMAL GRADIENT. THE NATURE
OF SOME OF THE SOUTHERN EDGE CLOUDS AS WELL AS 35-40DBZ ECHOES
ON COMPOSITE RADAR NEAR THE IA/MN BORDER INDICATE THE PRESENCE
OF AT LEAST WEAK INSTABILITY ALOFT AND LIKELY THE RESULT OF A
SUBTLE MID-LEVEL PERTURBATION PER SATELLITE AND RAP ANALYSIS.
IT IS POSSIBLE AS THIS CORRIDOR OF SHOWERY-TYPE ECHOES BRINGS
SOME SPRINKLES OR FLURRIES TO FAR NORTHERN IL EARLY TO MID
AFTERNOON...SO THAT IS WHY THE EARLIER MENTION IN THE
FORECAST. OVERALL THOUGH...THE DRIER SYNOPTIC AIR AND DRY
925-850MB TRAJECTORIES WILL LIKELY PREVENT ANY NOTEWORTHY PRECIP
INTO THIS EVE AND POSSIBLY THROUGH EARLY OVERNIGHT UNTIL STRONGER
FORCING WITH THE MAIN UPPER SHORT WAVE APPROACH.
THE CHALLENGE WITH THIS UPCOMING SNOW EVENT LOOKS TO BE IF THERE
WILL BE A CORRIDOR/BAND OF MODERATE SNOWFALL RATES DURING THE
DAYBREAK THROUGH MID-MORNING HOURS ON MONDAY...WHICH SOME HIGH
RESOLUTION MODELS INCLUDING THE 12Z NAM INDICATE AND THIS MAKES
SENSE SOMEWHERE IN THE REGION WITH THIS TYPE OF SYSTEM. IT IS
JUST PLACEMENT AND DURATION IS THE CHALLENGE. THESE MORE
APPRECIABLE RATES EVEN IF TEMPORARY WOULD HAVE AT LEAST A
SLIGHTLY GREATER IMPACT DUE TO OVERCOMING THE NOW WARMER PAVEMENT
AND GROUND TEMPERATURES. WILL CONTINUE TO LOOK AT GUIDANCE AND
REFINE THE FORECAST WITH MORE TEMPORAL AND SPATIAL RESOLUTION FOR
MONDAY MORNING AND IF NEEDED ISSUE SOME FORM OF STATEMENT TO
FURTHER HIGHLIGHT.
MTF
&&
.SHORT TERM...
235 AM CDT
THROUGH MONDAY...
MAIN CONCERN IN THE SHORT TERM WILL REVOLVE AROUND TIMING OF A
DEVELOPING MID-LVL SHORTWAVE FOR LATE TONIGHT INTO MONDAY
MORNING...WHICH WILL LIKELY BRING SOME LIGHT ACCUMULATING SNOWFALL
TO MAINLY NORTHERN IL. PRIOR TO THE ARRIVAL OF THIS SYSTEM...EARLY
THIS MORNING THE SURFACE ANTI-CYCLONIC FEATURE REMAINED CENTERED
OVER THE GREAT LAKES REGION. THIS FEATURE WAS SENDING MUCH DRIER AIR
SOUTH ACROSS THE WESTERN GREAT LAKES WITH NUMEROUS LOCATIONS IN WISC
SEEING DEW PTS IN THE SINGLE DIGITS TO LOW TEENS...ALTHOUGH ACROSS
NORTHERN IL DEW PTS REMAINED IN THE LOW/MID 20S. THIS WAS A RESULT
OF THE NORTHEAST WINDS ALLOWING THE MARINE ENVIRONMENT TO BLEED
INLAND.
GUIDANCE CONTINUES TO SUGGEST THE SFC RIDGE WILL REMAIN ORIENTED
ACROSS THE UPPER MIDWEST/GREAT LAKES STRETCHING NORTH INTO CENTRAL
ONTARIO THROUGH TONIGHT AND INTO MONDAY. THIS WILL MAINTAIN A
COOL/DRY NORTHEAST TO EAST LLVL FLOW ACROSS THE FORECAST AREA. IR
IMAGERY INDICATES A THIN CIRRUS SHIELD OVERHEAD...BUT WILL STEADILY
THICKEN AS THE AFTN/EVE PROGRESSES. HIGHS TODAY WILL STRUGGLE TO
WARM BEYOND THE LOW/MID 40S...WITH A FEW AREAS IN THE FAR SOUTHWEST
NEARING 50. AREAS ADJACENT TO LAKE MICHIGAN WILL BE UNDER THE
INFLUENCE OF A COLD MARINE ENVIRONMENT...LIKELY HOLDING TEMPS IN THE
UPR 30S WITHIN THE FIRST FEW MILES OF LAND AWAY FROM THE LAKE.
THE FOR TONIGHT...GUIDANCE HAS LOCKED IN THE DRY AIR WHICH APPEARS
TO BE DELAYING THE MOISTENING LOW/MID LVLS UNTIL LATE TONIGHT. USING
A T-LAG DISPLAY OF SOUNDINGS WOULD SUGGEST THE TREND HAS BEEN TO
PUSH BACK PRECIP UNTIL ARND 6Z BUT THAT TOO COULD BE A FEW HOURS
EARLY. HAVE HELD ONTO DRY CONDS LONGER WITH SLT CHC POPS ARRIVING
ARND 6Z...THEN STEADILY INCREASING TO LIKELY ARND 9Z THRU ABOUT 12-
14Z. A BAROCLINIC ZONE WILL BE ORIENTED FROM SOUTHEAST IOWA EAST
THROUGH CENTRAL IL INTO CENTRAL IN BY EARLY MON AFTN. THE LOW WILL
LIKELY FOLLO THIS ORIENTATION AS IT NEARS THE REGION LATE TONIGHT.
THERE CONTINUES TO BE SOME DEGREE OF UNCERTAINTY ON THE DURATION OF
THE SNOW...HOWEVER DYNAMICALLY SPEAKING THE FORCING CRANKS UP LATE
TONIGHT WITH STEEPING MID-LVL LAPSE RATES AND A TIGHTENING GRADIENT
ALONG THE BAROCLINIC ZONE. WITH STRONG ASCENT ALONG THE LEADING
EDGE...QUICK MOISTENING OF THE LLVLS SHUD OCCUR AND MAY ALLOW FOR A
FEW HRS OF MODERATE SNOW BETWEEN 10-14Z...BEFORE THE PROFILE BEGINS
TO WARM AND LIFT BEGINS TO DECREASE BY 15-17Z MON. SNOW ACCUMS ARE
POSSIBLE AND TIMING APPEARS TO BE JUST PRIOR TO RUSH-HOUR MON
MORNING...AND ENDING SHORTLY AFTER. CURRENT INDICATIONS ARE FOR ARND
1 INCH CLOSER TO CHICAGO...AND POSSIBLY UP TO 2 INCHES IN A FEW
AREAS ALONG AND WEST OF A DIXON TO CRYSTAL LAKE LINE. THICK SOLAR
SHIELDING WILL KEEP TEMPS WELL BELOW SEASONAL CONDS MON...WITH HIGHS
MAINLY IN THE MID/UPR 30S. PRECIP SHUD BE ENDING BY EARLY AFTN MON.
BEACHLER
&&
.LONG TERM...
354 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
ATTENTION DURING THE LONG TERM PERIOD IS MAINLY FOCUSED ON THE
POTENTIAL FOR A GOOD STORM SYSTEM TO IMPACT THE REGION LATE TUESDAY
THROUGH WEDNESDAY.
MODEL GUIDANCE CONTINUES IN DECENT AGREEMENT WITH THE EVOLUTION OF A
STORM SYSTEM ACROSS THE CENTRAL PORTION OF THE COUNTRY BY MID WEEK.
UPPER LEVEL ENERGY EMANATING FROM THE NORTHEASTERN PACIFIC IS
EXPECTED TO SHIFT EASTWARD ONSHORE ACROSS THE PACIFIC NORTHWEST BY
MONDAY...THEN OVER THE ROCKIES BY TUESDAY MORNING. THIS SHOULD SPAWN
SURFACE LOW PRESSURE OVER THE PLAINS DURING THE DAY TUESDAY. MODEL
GUIDANCE IS ALSO INSISTENT THAT THE MAIN MID/UPPER LEVEL SHORT WAVE
WILL BECOME NEGATIVELY TILTED AS IT MOVES OVER THE MID MISSOURI
VALLEY LATE TUESDAY INTO TUESDAY NIGHT. AS SUCH...THIS IS SHAPING UP
TO POSSIBLY BE A GOOD DYNAMIC SYSTEM CAPABLE OF PRODUCING
THUNDERSTORMS OVER THE AREA...ESPECIALLY TUESDAY NIGHT...FOLLOWED BY
SOME STRONG SYNOPIC WINDS INTO WEDNESDAY.
IT CURRENTLY APPEARS THAT MOST OF NORTHERN ILLINOIS/NORTHWESTERN
INDIANA MAY END UP STAYING DRY FOR MOST OF THE DAY TUESDAY AS MOST
OF THE SHOWERS LOOK TO REMAIN FOCUSED DOWN STATE IN CLOSER PROXIMITY
TO THE WARM FRONTAL BOUNDARY. FOR THIS REASON I HAVE CUT BACK ON
POPS ACROSS NORTHERN ILLINOIS DURING THE DAY TUESDAY. THE BEST
POTENTIAL FOR SHOWERS AND THUNDERSTORMS FOR THE AREA LOOKS TO BE
TUESDAY EVENING AND INTO THE PREDAWN HOURS OF OF WEDNESDAY MORNING.
THIS IS THE PERIOD WHEN THE MAIN MID LEVEL NEGATIVELY TILTED SYSTEM
BEGINS TO SHIFT OVER NORTHERN ILLINOIS. AS THIS OCCURS...THE SURFACE
LOW WILL ACCELERATE NORTHEASTWARD AND DEEPEN INTO WEDNESDAY. THIS
WILL RAPIDLY SHIFT THE WARM FRONT AND BETTER MOISTURE FROM DOWNSTATE
ILLINOIS RIGHT ACROSS THE AREA BY TUESDAY EVENING.
THINGS LOOK TO DRY OUT IN A HURRY BY EARLY WEDNESDAY FOLLOWING THE
PASSAGE OF THE MID LEVEL SYSTEM AND DRY PUNCH. THE MAIN WEATHER
ISSUE ON WEDNESDAY WILL BE THE POTENTIAL FOR STRONG WEST-
SOUTHWESTERLY WINDS. IT CURRENTLY APPEARS THAT WINDS COULD GUST TO
AROUND 40 TO 45 MPH ON WEDNESDAY AS THE COMBINATION OF MUCH DRIER
AIR...GOOD LARGE SCALE DECENT IN THE WAKE OF THE UPPER LEVEL SYSTEM
AND SOME DECENT SURFACE PRESSURE RISES...COULD LEAD TO EFFICIENT
ATMOSPHERIC MIXING OF STRONG WINDS OFF THE SURFACE.
MID/UPPER LEVEL HEIGHTS ARE EXPECTED TO BUILD ACROSS WESTERN NORTH
AMERICA BY MID WEEK...AND THIS WILL ULTIMATELY SET UP TROUGHING OVER
THE EASTERN CONUS...FEATURING NORTHWEST FLOW ALOFT OVER THE
WESTERN GREAT LAKES REGION. THEREFORE...MILD CONDITIONS TUESDAY
NIGHT AND WEDNESDAY WILL TRANSITION TO COLDER WEATHER AGAIN BY
THURSDAY AS THIS PATTERN ALLOWS MUCH COLDER AIR TO SPILL IN ACROSS
THE EASTERN CONUS FOR THE LATER HALF OF THE WEEK. HIGHS WILL
LIKELY END UP 10 TO 15 DEGREES BELOW AVERAGE FOR A FEW DAYS AT THE
END OF THE PERIOD (30S TO LOW 40S). IT ALSO APPEARS THAT THERE
COULD BE SOME PERIODIC EPISODES OF SNOW AND RAIN SHOWERS AS
ADDITIONAL MID LEVEL DISTURBANCES SHIFT SOUTHEASTWARD ACROSS THE
REGION.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* EAST/NORTHEAST WINDS 10-15KT WITH HIGHER GUSTS POSSIBLE THIS
AFTERNOON AND TONIGHT.
* CHANCE OF FLURRIES/SPRINKLES THIS AFTERNOON/EVENING.
* SNOW DEVELOPING 09Z-11Z WITH IFR CONDITIONS EXPECTED 12Z-17Z.
* SNOW MIXING WITH/CHANGING TO LIGHT FREEZING DRIZZLE/LIGHT RAIN
LATE MONDAY MORNING...THEN ENDING EARLY MONDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 18Z...
MID CLOUDS WILL CONTINUE TO SPREAD SOUTHEAST ACROSS THE AREA THIS
AFTERNOON AND THIS EVENING. RADAR ECHOS SUGGEST THIS MID DECK HAS
EXTENSIVE VIRGA...PRECIPIATION ALOFT...WITH VERY LITTLE REACHING
THE GROUND. ORD NOW REPORTING FLURRIES AND SOME FLURRIES OR
SPRINKLES ARE POSSIBLE BUT NOT EXPECTING ANY RESTRICTIONS TO VIS
OR CIGS. FURTHER NORTHWEST AT RFD...LOW LEVELS WILL LIKELY
SATURATE SOONER AND DID INCLUDE A MENTION OF VFR SPRINKLES/
FLURRIES THIS AFTERNOON.
AS AN UPPER WAVE MOVES ACROSS THE AREA MONDAY MORNING...SNOW IS
EXPECTED TO DEVELOP. AT FIRST IT MAY BE MAINLY ACROSS SOUTHERN WI
AND FAR NORTHERN IL BEFORE EXPANDING/DEVELOPING ACROSS THE ENTIRE
AREA AROUND/JUST PRIOR TO DAYBREAK. THUS CONFIDENCE REGARDING
SPECIFIC START TIMES AND THE ASSOCIATED VIS/CIGS IS LOW. BUT
EVENTUALLY...09Z-10Z AT RFD AND 12Z-13Z AT ORD/MDW...GUIDANCE
SUGGESTS A 3-6 HOUR PERIOD OF PREVAILING SNOW...POSSIBLY MODERATE
SNOW. SO CONFIDENCE OF THE OVERALL TREND IS MEDIUM TO HIGH. THIS
SHOULD ALLOW CIGS/VIS TO DROP TO IFR AND LIFR VIS IS ALSO
POSSIBLE. PRECIP END TIME APPEARS TO BE IN THE 17Z-19Z TIME FRAME
AS PRECIP SHIFTS SOUTHEAST AND THE SYSTEM BEGINS TO WEAKEN. BUT
PRECIP TYPE DURING THIS TIME IS UNCERTAIN. PRECIP COULD MIX WITH
FREEZING DRIZZLE AND THEN POSSIBLY END AS DRIZZLE/LIGHT RAIN.
EASTERLY WINDS HAVE BEEN PREVAILING 10-15KTS ALL MORNING AND
LITTLE CHANGE IS EXPECTED INTO THIS EVENING WITH SOME HIGHER
GUSTS POSSIBLE. WINDS WILL REMAIN EASTERLY INTO MONDAY MORNING
WITH SPEEDS LIKELY AROUND OR JUST ABOVE 10KT. CMS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH FOR WINDS THRU THE PERIOD.
* MEDIUM FOR FLURRIES/SPRINKLES THIS AFTERNOON.
* HIGH FOR SNOW MONDAY MORNING...MEDIUM FOR ASSOCIATED CIGS/VIS
AND MEDIUM FOR START/END TIMES. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MAINLY VFR CONDS. PATCHY MVFR CIGS.
TUESDAY...CHANCE OF RAIN TUESDAY AFTERNOON. RAIN LIKELY/THUNDER
POSSIBLE AT NIGHT. MVFR/IFR POSSIBLE. BREEZY SOUTHEAST WINDS.
WEDNESDAY...SLIGHT CHANCE OF SHOWERS WITH MVFR EARLY. GUSTY WEST-
SOUTHWEST WINDS.
THURSDAY...SLIGHT CHANCE OF SHOWERS. MVFR POSSIBLE.
FRIDAY...VFR.
SATURDAY...VFR.
BEACHLER
&&
.MARINE...
425 AM CDT
A SURFACE RIDGE OF HIGH PRESSURE WILL SHIFT OVER SOUTHERN CANADA AND
THE UPPER GREAT LAKES THROUGH MONDAY. THIS WILL RESULT IN A
CONTINUED PERIOD OF NORTHERLY WINDS UP TO AROUND 20 KT TODAY AND
TONIGHT. THEREFORE...EXPECT WAVES OF 3 TO 5 FEET TO CONTINUE FOR THE
NEAR SHORE WATERS OF NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA.
ANOTHER STORM SYSTEM IS EXPECTED TO IMPACT THE WESTERN GREAT LAKES
REGION LATE TUESDAY THROUGH WEDNESDAY. THE SURFACE LOW IS FORECAST
TO TRACK EAST-NORTHEASTWARD FROM THE PLAINS TO THE UPPER GREAT LAKES
BY WEDNESDAY MORNING. THIS LOOKS TO RESULT IN A PERIOD OF INCREASING
SOUTHEASTERLY WINDS OF 25 TO 30 KT TUESDAY NIGHT...FOLLOWED BY A
PERIOD OF STRONG WEST-SOUTHWESTERLY WINDS ON WEDNESDAY. GALE FORCE
WINDS ARE POSSIBLE ON WEDNESDAY...ESPECIALLY ACROSS THE ILLINOIS
AND INDIANA NEAR SHORES. WINDS WILL THEN SHIFT BACK OUT OF THE NORTH
BY LATE WEEK AS A REINFORCING COLD FRONT DROPS SOUTHWARD DOWN THE
LAKE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1103 AM CDT SUN MAR 22 2015
.UPDATE...
1025 AM CDT
ONLY SMALL CHANGES MADE TO THE FORECAST FOR THIS AFTERNOON.
HAVE ADDED THE MENTION OF SOME FLURRIES OR POSSIBLY SPRINKLES
THIS AFTERNOON IN FAR NORTHERN ILLINOIS...BUT AS FOR THIS
EVENING CONTINUE TO DELAY MENTION OF MEASURABLE PRECIPITATION
CHANCES.
A CANOPY OF MID-LEVEL CLOUDS FROM SOUTHERN/CENTRAL MN THROUGH
FAR NORTHERN IL AND SOUTHERN LAKE MI HIGHLIGHTS A WEAK ZONE OF
MID-LEVEL FORCING ALONG A MODEST THERMAL GRADIENT. THE NATURE
OF SOME OF THE SOUTHERN EDGE CLOUDS AS WELL AS 35-40DBZ ECHOES
ON COMPOSITE RADAR NEAR THE IA/MN BORDER INDICATE THE PRESENCE
OF AT LEAST WEAK INSTABILITY ALOFT AND LIKELY THE RESULT OF A
SUBTLE MID-LEVEL PERTURBATION PER SATELLITE AND RAP ANALYSIS.
IT IS POSSIBLE AS THIS CORRIDOR OF SHOWERY-TYPE ECHOES BRINGS
SOME SPRINKLES OR FLURRIES TO FAR NORTHERN IL EARLY TO MID
AFTERNOON...SO THAT IS WHY THE EARLIER MENTION IN THE
FORECAST. OVERALL THOUGH...THE DRIER SYNOPTIC AIR AND DRY
925-850MB TRAJECTORIES WILL LIKELY PREVENT ANY NOTEWORTHY PRECIP
INTO THIS EVE AND POSSIBLY THROUGH EARLY OVERNIGHT UNTIL STRONGER
FORCING WITH THE MAIN UPPER SHORT WAVE APPROACH.
THE CHALLENGE WITH THIS UPCOMING SNOW EVENT LOOKS TO BE IF THERE
WILL BE A CORRIDOR/BAND OF MODERATE SNOWFALL RATES DURING THE
DAYBREAK THROUGH MID-MORNING HOURS ON MONDAY...WHICH SOME HIGH
RESOLUTION MODELS INCLUDING THE 12Z NAM INDICATE AND THIS MAKES
SENSE SOMEWHERE IN THE REGION WITH THIS TYPE OF SYSTEM. IT IS
JUST PLACEMENT AND DURATION IS THE CHALLENGE. THESE MORE
APPRECIABLE RATES EVEN IF TEMPORARY WOULD HAVE AT LEAST A
SLIGHTLY GREATER IMPACT DUE TO OVERCOMING THE NOW WARMER PAVEMENT
AND GROUND TEMPERATURES. WILL CONTINUE TO LOOK AT GUIDANCE AND
REFINE THE FORECAST WITH MORE TEMPORAL AND SPATIAL RESOLUTION FOR
MONDAY MORNING AND IF NEEDED ISSUE SOME FORM OF STATEMENT TO
FURTHER HIGHLIGHT.
MTF
&&
.SHORT TERM...
235 AM CDT
THROUGH MONDAY...
MAIN CONCERN IN THE SHORT TERM WILL REVOLVE AROUND TIMING OF A
DEVELOPING MID-LVL SHORTWAVE FOR LATE TONIGHT INTO MONDAY
MORNING...WHICH WILL LIKELY BRING SOME LIGHT ACCUMULATING SNOWFALL
TO MAINLY NORTHERN IL. PRIOR TO THE ARRIVAL OF THIS SYSTEM...EARLY
THIS MORNING THE SURFACE ANTI-CYCLONIC FEATURE REMAINED CENTERED
OVER THE GREAT LAKES REGION. THIS FEATURE WAS SENDING MUCH DRIER AIR
SOUTH ACROSS THE WESTERN GREAT LAKES WITH NUMEROUS LOCATIONS IN WISC
SEEING DEW PTS IN THE SINGLE DIGITS TO LOW TEENS...ALTHOUGH ACROSS
NORTHERN IL DEW PTS REMAINED IN THE LOW/MID 20S. THIS WAS A RESULT
OF THE NORTHEAST WINDS ALLOWING THE MARINE ENVIRONMENT TO BLEED
INLAND.
GUIDANCE CONTINUES TO SUGGEST THE SFC RIDGE WILL REMAIN ORIENTED
ACROSS THE UPPER MIDWEST/GREAT LAKES STRETCHING NORTH INTO CENTRAL
ONTARIO THROUGH TONIGHT AND INTO MONDAY. THIS WILL MAINTAIN A
COOL/DRY NORTHEAST TO EAST LLVL FLOW ACROSS THE FORECAST AREA. IR
IMAGERY INDICATES A THIN CIRRUS SHIELD OVERHEAD...BUT WILL STEADILY
THICKEN AS THE AFTN/EVE PROGRESSES. HIGHS TODAY WILL STRUGGLE TO
WARM BEYOND THE LOW/MID 40S...WITH A FEW AREAS IN THE FAR SOUTHWEST
NEARING 50. AREAS ADJACENT TO LAKE MICHIGAN WILL BE UNDER THE
INFLUENCE OF A COLD MARINE ENVIRONMENT...LIKELY HOLDING TEMPS IN THE
UPR 30S WITHIN THE FIRST FEW MILES OF LAND AWAY FROM THE LAKE.
THE FOR TONIGHT...GUIDANCE HAS LOCKED IN THE DRY AIR WHICH APPEARS
TO BE DELAYING THE MOISTENING LOW/MID LVLS UNTIL LATE TONIGHT. USING
A T-LAG DISPLAY OF SOUNDINGS WOULD SUGGEST THE TREND HAS BEEN TO
PUSH BACK PRECIP UNTIL ARND 6Z BUT THAT TOO COULD BE A FEW HOURS
EARLY. HAVE HELD ONTO DRY CONDS LONGER WITH SLT CHC POPS ARRIVING
ARND 6Z...THEN STEADILY INCREASING TO LIKELY ARND 9Z THRU ABOUT 12-
14Z. A BAROCLINIC ZONE WILL BE ORIENTED FROM SOUTHEAST IOWA EAST
THROUGH CENTRAL IL INTO CENTRAL IN BY EARLY MON AFTN. THE LOW WILL
LIKELY FOLLO THIS ORIENTATION AS IT NEARS THE REGION LATE TONIGHT.
THERE CONTINUES TO BE SOME DEGREE OF UNCERTAINTY ON THE DURATION OF
THE SNOW...HOWEVER DYNAMICALLY SPEAKING THE FORCING CRANKS UP LATE
TONIGHT WITH STEEPING MID-LVL LAPSE RATES AND A TIGHTENING GRADIENT
ALONG THE BAROCLINIC ZONE. WITH STRONG ASCENT ALONG THE LEADING
EDGE...QUICK MOISTENING OF THE LLVLS SHUD OCCUR AND MAY ALLOW FOR A
FEW HRS OF MODERATE SNOW BETWEEN 10-14Z...BEFORE THE PROFILE BEGINS
TO WARM AND LIFT BEGINS TO DECREASE BY 15-17Z MON. SNOW ACCUMS ARE
POSSIBLE AND TIMING APPEARS TO BE JUST PRIOR TO RUSH-HOUR MON
MORNING...AND ENDING SHORTLY AFTER. CURRENT INDICATIONS ARE FOR ARND
1 INCH CLOSER TO CHICAGO...AND POSSIBLY UP TO 2 INCHES IN A FEW
AREAS ALONG AND WEST OF A DIXON TO CRYSTAL LAKE LINE. THICK SOLAR
SHIELDING WILL KEEP TEMPS WELL BELOW SEASONAL CONDS MON...WITH HIGHS
MAINLY IN THE MID/UPR 30S. PRECIP SHUD BE ENDING BY EARLY AFTN MON.
BEACHLER
&&
.LONG TERM...
354 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
ATTENTION DURING THE LONG TERM PERIOD IS MAINLY FOCUSED ON THE
POTENTIAL FOR A GOOD STORM SYSTEM TO IMPACT THE REGION LATE TUESDAY
THROUGH WEDNESDAY.
MODEL GUIDANCE CONTINUES IN DECENT AGREEMENT WITH THE EVOLUTION OF A
STORM SYSTEM ACROSS THE CENTRAL PORTION OF THE COUNTRY BY MID WEEK.
UPPER LEVEL ENERGY EMANATING FROM THE NORTHEASTERN PACIFIC IS
EXPECTED TO SHIFT EASTWARD ONSHORE ACROSS THE PACIFIC NORTHWEST BY
MONDAY...THEN OVER THE ROCKIES BY TUESDAY MORNING. THIS SHOULD SPAWN
SURFACE LOW PRESSURE OVER THE PLAINS DURING THE DAY TUESDAY. MODEL
GUIDANCE IS ALSO INSISTENT THAT THE MAIN MID/UPPER LEVEL SHORT WAVE
WILL BECOME NEGATIVELY TILTED AS IT MOVES OVER THE MID MISSOURI
VALLEY LATE TUESDAY INTO TUESDAY NIGHT. AS SUCH...THIS IS SHAPING UP
TO POSSIBLY BE A GOOD DYNAMIC SYSTEM CAPABLE OF PRODUCING
THUNDERSTORMS OVER THE AREA...ESPECIALLY TUESDAY NIGHT...FOLLOWED BY
SOME STRONG SYNOPIC WINDS INTO WEDNESDAY.
IT CURRENTLY APPEARS THAT MOST OF NORTHERN ILLINOIS/NORTHWESTERN
INDIANA MAY END UP STAYING DRY FOR MOST OF THE DAY TUESDAY AS MOST
OF THE SHOWERS LOOK TO REMAIN FOCUSED DOWN STATE IN CLOSER PROXIMITY
TO THE WARM FRONTAL BOUNDARY. FOR THIS REASON I HAVE CUT BACK ON
POPS ACROSS NORTHERN ILLINOIS DURING THE DAY TUESDAY. THE BEST
POTENTIAL FOR SHOWERS AND THUNDERSTORMS FOR THE AREA LOOKS TO BE
TUESDAY EVENING AND INTO THE PREDAWN HOURS OF OF WEDNESDAY MORNING.
THIS IS THE PERIOD WHEN THE MAIN MID LEVEL NEGATIVELY TILTED SYSTEM
BEGINS TO SHIFT OVER NORTHERN ILLINOIS. AS THIS OCCURS...THE SURFACE
LOW WILL ACCELERATE NORTHEASTWARD AND DEEPEN INTO WEDNESDAY. THIS
WILL RAPIDLY SHIFT THE WARM FRONT AND BETTER MOISTURE FROM DOWNSTATE
ILLINOIS RIGHT ACROSS THE AREA BY TUESDAY EVENING.
THINGS LOOK TO DRY OUT IN A HURRY BY EARLY WEDNESDAY FOLLOWING THE
PASSAGE OF THE MID LEVEL SYSTEM AND DRY PUNCH. THE MAIN WEATHER
ISSUE ON WEDNESDAY WILL BE THE POTENTIAL FOR STRONG WEST-
SOUTHWESTERLY WINDS. IT CURRENTLY APPEARS THAT WINDS COULD GUST TO
AROUND 40 TO 45 MPH ON WEDNESDAY AS THE COMBINATION OF MUCH DRIER
AIR...GOOD LARGE SCALE DECENT IN THE WAKE OF THE UPPER LEVEL SYSTEM
AND SOME DECENT SURFACE PRESSURE RISES...COULD LEAD TO EFFICIENT
ATMOSPHERIC MIXING OF STRONG WINDS OFF THE SURFACE.
MID/UPPER LEVEL HEIGHTS ARE EXPECTED TO BUILD ACROSS WESTERN NORTH
AMERICA BY MID WEEK...AND THIS WILL ULTIMATELY SET UP TROUGHING OVER
THE EASTERN CONUS...FEATURING NORTHWEST FLOW ALOFT OVER THE
WESTERN GREAT LAKES REGION. THEREFORE...MILD CONDITIONS TUESDAY
NIGHT AND WEDNESDAY WILL TRANSITION TO COLDER WEATHER AGAIN BY
THURSDAY AS THIS PATTERN ALLOWS MUCH COLDER AIR TO SPILL IN ACROSS
THE EASTERN CONUS FOR THE LATER HALF OF THE WEEK. HIGHS WILL
LIKELY END UP 10 TO 15 DEGREES BELOW AVERAGE FOR A FEW DAYS AT THE
END OF THE PERIOD (30S TO LOW 40S). IT ALSO APPEARS THAT THERE
COULD BE SOME PERIODIC EPISODES OF SNOW AND RAIN SHOWERS AS
ADDITIONAL MID LEVEL DISTURBANCES SHIFT SOUTHEASTWARD ACROSS THE
REGION.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* NORTHEAST WINDS 10 TO 15 KT THRU THIS EVENING...WITH HIGHER
GUSTS POSSIBLE.
* SNOW DEVELOPING AROUND DAYBREAK MONDAY MORNING WITH MVFR
CIGS/VIS...IFR POSSIBLE. CMS
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE REMAINS CENTERED TO THE NORTH OF THE REGION...AND
WILL CONTINUE TO ALLOW NORTHEAST TO EAST WINDS THRU THE DURATION
OF THE CURRENT TAF. WITH THE LACK OF MIXING OVERNIGHT...THE WIND
SPEEDS HAVE FALLEN OFF SLIGHTLY. EXPECT SHORTLY AFTER DAYBREAK THE
WIND SPEEDS TO PICK BACK UP AND GUSTS TO 15KT WILL BE FREQUENT.
THE LOW/MID LVLS IN THE ATMOSPHERE REMAIN VERY DRY...WHICH WILL
ALLOW MINIMAL CLOUDS IN THE LOWER LEVELS. A CIRRUS SHIELD WILL
STEADILY THICKEN AND BEGIN TO LOWER...ALTHOUGH EXPECT VFR CONDS TO
PREVAIL THRU AT LEAST 00Z AND POSSIBLY BEYOND 6Z MON TONIGHT.
THE FOCUS THEN TURNS TOWARDS THE DEVELOPING LOW PRESSURE SYSTEM
ACROSS THE CENTRAL PLAINS...THAT GUIDANCE HAS CONTINUED TO SUGGEST
WILL STRENGTHEN PRIOR TO ARRIVAL OVER THE REGION LATE SUN NIGHT
INTO EARLY MON. GUIDANCE CONTINUES TO DELAY THE ONSET...ARRIVING
ACROSS FAR NORTHWEST IL ARND 6-8Z. THEN POSSIBLY NOT REACHING
ORD/MDW UNTIL ARND 10-12Z. IT STILL APPEARS FAVORABLE FOR LGT
SNOW AND A PERIOD OF MODERATE SNOW MAY ACCOMPANY THE SYSTEM AROUND
DAYBREAK MON FOR A FEW HOURS...WITH LIGHT ACCUMULATIONS. CIGS SHUD
LOWER QUICKLY WITH THE STEADIER SNOW...AND MAY TOUCH IFR CONDS AS
THE GRADIENT SLACKENS.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH FOR WINDS THRU THE PERIOD.
* MEDIUM FOR PRECIP TIMING/DURATION/CIGS/VIS MONDAY MORNING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MAINLY VFR CONDS. PATCHY MVFR CIGS.
TUESDAY...CHANCE OF RAIN TUESDAY AFTERNOON. RAIN LIKELY/THUNDER
POSSIBLE AT NIGHT. MVFR/IFR POSSIBLE. BREEZY SOUTHEAST WINDS.
WEDNESDAY...SLIGHT CHANCE OF SHOWERS WITH MVFR EARLY. GUSTY WEST-
SOUTHWEST WINDS.
THURSDAY...SLIGHT CHANCE OF SHOWERS. MVFR POSSIBLE.
FRIDAY...VFR.
SATURDAY...VFR.
BEACHLER
&&
.MARINE...
425 AM CDT
A SURFACE RIDGE OF HIGH PRESSURE WILL SHIFT OVER SOUTHERN CANADA AND
THE UPPER GREAT LAKES THROUGH MONDAY. THIS WILL RESULT IN A
CONTINUED PERIOD OF NORTHERLY WINDS UP TO AROUND 20 KT TODAY AND
TONIGHT. THEREFORE...EXPECT WAVES OF 3 TO 5 FEET TO CONTINUE FOR THE
NEAR SHORE WATERS OF NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA.
ANOTHER STORM SYSTEM IS EXPECTED TO IMPACT THE WESTERN GREAT LAKES
REGION LATE TUESDAY THROUGH WEDNESDAY. THE SURFACE LOW IS FORECAST
TO TRACK EAST-NORTHEASTWARD FROM THE PLAINS TO THE UPPER GREAT LAKES
BY WEDNESDAY MORNING. THIS LOOKS TO RESULT IN A PERIOD OF INCREASING
SOUTHEASTERLY WINDS OF 25 TO 30 KT TUESDAY NIGHT...FOLLOWED BY A
PERIOD OF STRONG WEST-SOUTHWESTERLY WINDS ON WEDNESDAY. GALE FORCE
WINDS ARE POSSIBLE ON WEDNESDAY...ESPECIALLY ACROSS THE ILLINOIS
AND INDIANA NEAR SHORES. WINDS WILL THEN SHIFT BACK OUT OF THE NORTH
BY LATE WEEK AS A REINFORCING COLD FRONT DROPS SOUTHWARD DOWN THE
LAKE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1026 AM CDT SUN MAR 22 2015
.UPDATE...
1025 AM CDT
ONLY SMALL CHANGES MADE TO THE FORECAST FOR THIS AFTERNOON.
HAVE ADDED THE MENTION OF SOME FLURRIES OR POSSIBLY SPRINKLES
THIS AFTERNOON IN FAR NORTHERN ILLINOIS...BUT AS FOR THIS
EVENING CONTINUE TO DELAY MENTION OF MEASURABLE PRECIPITATION
CHANCES.
A CANOPY OF MID-LEVEL CLOUDS FROM SOUTHERN/CENTRAL MN THROUGH
FAR NORTHERN IL AND SOUTHERN LAKE MI HIGHLIGHTS A WEAK ZONE OF
MID-LEVEL FORCING ALONG A MODEST THERMAL GRADIENT. THE NATURE
OF SOME OF THE SOUTHERN EDGE CLOUDS AS WELL AS 35-40DBZ ECHOES
ON COMPOSITE RADAR NEAR THE IA/MN BORDER INDICATE THE PRESENCE
OF AT LEAST WEAK INSTABILITY ALOFT AND LIKELY THE RESULT OF A
SUBTLE MID-LEVEL PERTURBATION PER SATELLITE AND RAP ANALYSIS.
IT IS POSSIBLE AS THIS CORRIDOR OF SHOWERY-TYPE ECHOES BRINGS
SOME SPRINKLES OR FLURRIES TO FAR NORTHERN IL EARLY TO MID
AFTERNOON...SO THAT IS WHY THE EARLIER MENTION IN THE
FORECAST. OVERALL THOUGH...THE DRIER SYNOPTIC AIR AND DRY
925-850MB TRAJECTORIES WILL LIKELY PREVENT ANY NOTEWORTHY PRECIP
INTO THIS EVE AND POSSIBLY THROUGH EARLY OVERNIGHT UNTIL STRONGER
FORCING WITH THE MAIN UPPER SHORT WAVE APPROACH.
THE CHALLENGE WITH THIS UPCOMING SNOW EVENT LOOKS TO BE IF THERE
WILL BE A CORRIDOR/BAND OF MODERATE SNOWFALL RATES DURING THE
DAYBREAK THROUGH MID-MORNING HOURS ON MONDAY...WHICH SOME HIGH
RESOLUTION MODELS INCLUDING THE 12Z NAM INDICATE AND THIS MAKES
SENSE SOMEWHERE IN THE REGION WITH THIS TYPE OF SYSTEM. IT IS
JUST PLACEMENT AND DURATION IS THE CHALLENGE. THESE MORE
APPRECIABLE RATES EVEN IF TEMPORARY WOULD HAVE AT LEAST A
SLIGHTLY GREATER IMPACT DUE TO OVERCOMING THE NOW WARMER PAVEMENT
AND GROUND TEMPERATURES. WILL CONTINUE TO LOOK AT GUIDANCE AND
REFINE THE FORECAST WITH MORE TEMPORAL AND SPATIAL RESOLUTION FOR
MONDAY MORNING AND IF NEEDED ISSUE SOME FORM OF STATEMENT TO
FURTHER HIGHLIGHT.
MTF
&&
.SHORT TERM...
235 AM CDT
THROUGH MONDAY...
MAIN CONCERN IN THE SHORT TERM WILL REVOLVE AROUND TIMING OF A
DEVELOPING MID-LVL SHORTWAVE FOR LATE TONIGHT INTO MONDAY
MORNING...WHICH WILL LIKELY BRING SOME LIGHT ACCUMULATING SNOWFALL
TO MAINLY NORTHERN IL. PRIOR TO THE ARRIVAL OF THIS SYSTEM...EARLY
THIS MORNING THE SURFACE ANTI-CYCLONIC FEATURE REMAINED CENTERED
OVER THE GREAT LAKES REGION. THIS FEATURE WAS SENDING MUCH DRIER AIR
SOUTH ACROSS THE WESTERN GREAT LAKES WITH NUMEROUS LOCATIONS IN WISC
SEEING DEW PTS IN THE SINGLE DIGITS TO LOW TEENS...ALTHOUGH ACROSS
NORTHERN IL DEW PTS REMAINED IN THE LOW/MID 20S. THIS WAS A RESULT
OF THE NORTHEAST WINDS ALLOWING THE MARINE ENVIRONMENT TO BLEED
INLAND.
GUIDANCE CONTINUES TO SUGGEST THE SFC RIDGE WILL REMAIN ORIENTED
ACROSS THE UPPER MIDWEST/GREAT LAKES STRETCHING NORTH INTO CENTRAL
ONTARIO THROUGH TONIGHT AND INTO MONDAY. THIS WILL MAINTAIN A
COOL/DRY NORTHEAST TO EAST LLVL FLOW ACROSS THE FORECAST AREA. IR
IMAGERY INDICATES A THIN CIRRUS SHIELD OVERHEAD...BUT WILL STEADILY
THICKEN AS THE AFTN/EVE PROGRESSES. HIGHS TODAY WILL STRUGGLE TO
WARM BEYOND THE LOW/MID 40S...WITH A FEW AREAS IN THE FAR SOUTHWEST
NEARING 50. AREAS ADJACENT TO LAKE MICHIGAN WILL BE UNDER THE
INFLUENCE OF A COLD MARINE ENVIRONMENT...LIKELY HOLDING TEMPS IN THE
UPR 30S WITHIN THE FIRST FEW MILES OF LAND AWAY FROM THE LAKE.
THE FOR TONIGHT...GUIDANCE HAS LOCKED IN THE DRY AIR WHICH APPEARS
TO BE DELAYING THE MOISTENING LOW/MID LVLS UNTIL LATE TONIGHT. USING
A T-LAG DISPLAY OF SOUNDINGS WOULD SUGGEST THE TREND HAS BEEN TO
PUSH BACK PRECIP UNTIL ARND 6Z BUT THAT TOO COULD BE A FEW HOURS
EARLY. HAVE HELD ONTO DRY CONDS LONGER WITH SLT CHC POPS ARRIVING
ARND 6Z...THEN STEADILY INCREASING TO LIKELY ARND 9Z THRU ABOUT 12-
14Z. A BAROCLINIC ZONE WILL BE ORIENTED FROM SOUTHEAST IOWA EAST
THROUGH CENTRAL IL INTO CENTRAL IN BY EARLY MON AFTN. THE LOW WILL
LIKELY FOLLO THIS ORIENTATION AS IT NEARS THE REGION LATE TONIGHT.
THERE CONTINUES TO BE SOME DEGREE OF UNCERTAINTY ON THE DURATION OF
THE SNOW...HOWEVER DYNAMICALLY SPEAKING THE FORCING CRANKS UP LATE
TONIGHT WITH STEEPING MID-LVL LAPSE RATES AND A TIGHTENING GRADIENT
ALONG THE BAROCLINIC ZONE. WITH STRONG ASCENT ALONG THE LEADING
EDGE...QUICK MOISTENING OF THE LLVLS SHUD OCCUR AND MAY ALLOW FOR A
FEW HRS OF MODERATE SNOW BETWEEN 10-14Z...BEFORE THE PROFILE BEGINS
TO WARM AND LIFT BEGINS TO DECREASE BY 15-17Z MON. SNOW ACCUMS ARE
POSSIBLE AND TIMING APPEARS TO BE JUST PRIOR TO RUSH-HOUR MON
MORNING...AND ENDING SHORTLY AFTER. CURRENT INDICATIONS ARE FOR ARND
1 INCH CLOSER TO CHICAGO...AND POSSIBLY UP TO 2 INCHES IN A FEW
AREAS ALONG AND WEST OF A DIXON TO CRYSTAL LAKE LINE. THICK SOLAR
SHIELDING WILL KEEP TEMPS WELL BELOW SEASONAL CONDS MON...WITH HIGHS
MAINLY IN THE MID/UPR 30S. PRECIP SHUD BE ENDING BY EARLY AFTN MON.
BEACHLER
&&
.LONG TERM...
354 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
ATTENTION DURING THE LONG TERM PERIOD IS MAINLY FOCUSED ON THE
POTENTIAL FOR A GOOD STORM SYSTEM TO IMPACT THE REGION LATE TUESDAY
THROUGH WEDNESDAY.
MODEL GUIDANCE CONTINUES IN DECENT AGREEMENT WITH THE EVOLUTION OF A
STORM SYSTEM ACROSS THE CENTRAL PORTION OF THE COUNTRY BY MID WEEK.
UPPER LEVEL ENERGY EMANATING FROM THE NORTHEASTERN PACIFIC IS
EXPECTED TO SHIFT EASTWARD ONSHORE ACROSS THE PACIFIC NORTHWEST BY
MONDAY...THEN OVER THE ROCKIES BY TUESDAY MORNING. THIS SHOULD SPAWN
SURFACE LOW PRESSURE OVER THE PLAINS DURING THE DAY TUESDAY. MODEL
GUIDANCE IS ALSO INSISTENT THAT THE MAIN MID/UPPER LEVEL SHORT WAVE
WILL BECOME NEGATIVELY TILTED AS IT MOVES OVER THE MID MISSOURI
VALLEY LATE TUESDAY INTO TUESDAY NIGHT. AS SUCH...THIS IS SHAPING UP
TO POSSIBLY BE A GOOD DYNAMIC SYSTEM CAPABLE OF PRODUCING
THUNDERSTORMS OVER THE AREA...ESPECIALLY TUESDAY NIGHT...FOLLOWED BY
SOME STRONG SYNOPIC WINDS INTO WEDNESDAY.
IT CURRENTLY APPEARS THAT MOST OF NORTHERN ILLINOIS/NORTHWESTERN
INDIANA MAY END UP STAYING DRY FOR MOST OF THE DAY TUESDAY AS MOST
OF THE SHOWERS LOOK TO REMAIN FOCUSED DOWN STATE IN CLOSER PROXIMITY
TO THE WARM FRONTAL BOUNDARY. FOR THIS REASON I HAVE CUT BACK ON
POPS ACROSS NORTHERN ILLINOIS DURING THE DAY TUESDAY. THE BEST
POTENTIAL FOR SHOWERS AND THUNDERSTORMS FOR THE AREA LOOKS TO BE
TUESDAY EVENING AND INTO THE PREDAWN HOURS OF OF WEDNESDAY MORNING.
THIS IS THE PERIOD WHEN THE MAIN MID LEVEL NEGATIVELY TILTED SYSTEM
BEGINS TO SHIFT OVER NORTHERN ILLINOIS. AS THIS OCCURS...THE SURFACE
LOW WILL ACCELERATE NORTHEASTWARD AND DEEPEN INTO WEDNESDAY. THIS
WILL RAPIDLY SHIFT THE WARM FRONT AND BETTER MOISTURE FROM DOWNSTATE
ILLINOIS RIGHT ACROSS THE AREA BY TUESDAY EVENING.
THINGS LOOK TO DRY OUT IN A HURRY BY EARLY WEDNESDAY FOLLOWING THE
PASSAGE OF THE MID LEVEL SYSTEM AND DRY PUNCH. THE MAIN WEATHER
ISSUE ON WEDNESDAY WILL BE THE POTENTIAL FOR STRONG WEST-
SOUTHWESTERLY WINDS. IT CURRENTLY APPEARS THAT WINDS COULD GUST TO
AROUND 40 TO 45 MPH ON WEDNESDAY AS THE COMBINATION OF MUCH DRIER
AIR...GOOD LARGE SCALE DECENT IN THE WAKE OF THE UPPER LEVEL SYSTEM
AND SOME DECENT SURFACE PRESSURE RISES...COULD LEAD TO EFFICIENT
ATMOSPHERIC MIXING OF STRONG WINDS OFF THE SURFACE.
MID/UPPER LEVEL HEIGHTS ARE EXPECTED TO BUILD ACROSS WESTERN NORTH
AMERICA BY MID WEEK...AND THIS WILL ULTIMATELY SET UP TROUGHING OVER
THE EASTERN CONUS...FEATURING NORTHWEST FLOW ALOFT OVER THE
WESTERN GREAT LAKES REGION. THEREFORE...MILD CONDITIONS TUESDAY
NIGHT AND WEDNESDAY WILL TRANSITION TO COLDER WEATHER AGAIN BY
THURSDAY AS THIS PATTERN ALLOWS MUCH COLDER AIR TO SPILL IN ACROSS
THE EASTERN CONUS FOR THE LATER HALF OF THE WEEK. HIGHS WILL
LIKELY END UP 10 TO 15 DEGREES BELOW AVERAGE FOR A FEW DAYS AT THE
END OF THE PERIOD (30S TO LOW 40S). IT ALSO APPEARS THAT THERE
COULD BE SOME PERIODIC EPISODES OF SNOW AND RAIN SHOWERS AS
ADDITIONAL MID LEVEL DISTURBANCES SHIFT SOUTHEASTWARD ACROSS THE
REGION.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* NORTHEAST WINDS 10 TO 15 KT THRU THIS EVENING...WITH HIGHER
GUSTS POSSIBLE.
* SNOW DEVELOPING AROUND DAYBREAK MONDAY MORNING WITH MVFR
CIGS/VIS...IFR POSSIBLE. CMS
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE REMAINS CENTERED TO THE NORTH OF THE REGION...AND
WILL CONTINUE TO ALLOW NORTHEAST TO EAST WINDS THRU THE DURATION
OF THE CURRENT TAF. WITH THE LACK OF MIXING OVERNIGHT...THE WIND
SPEEDS HAVE FALLEN OFF SLIGHTLY. EXPECT SHORTLY AFTER DAYBREAK THE
WIND SPEEDS TO PICK BACK UP AND GUSTS TO 15KT WILL BE FREQUENT.
THE LOW/MID LVLS IN THE ATMOSPHERE REMAIN VERY DRY...WHICH WILL
ALLOW MINIMAL CLOUDS IN THE LOWER LEVELS. A CIRRUS SHIELD WILL
STEADILY THICKEN AND BEGIN TO LOWER...ALTHOUGH EXPECT VFR CONDS TO
PREVAIL THRU AT LEAST 00Z AND POSSIBLY BEYOND 6Z MON TONIGHT.
THE FOCUS THEN TURNS TOWARDS THE DEVELOPING LOW PRESSURE SYSTEM
ACROSS THE CENTRAL PLAINS...THAT GUIDANCE HAS CONTINUED TO SUGGEST
WILL STRENGTHEN PRIOR TO ARRIVAL OVER THE REGION LATE SUN NIGHT
INTO EARLY MON. GUIDANCE CONTINUES TO DELAY THE ONSET...ARRIVING
ACROSS FAR NORTHWEST IL ARND 6-8Z. THEN POSSIBLY NOT REACHING
ORD/MDW UNTIL ARND 10-12Z. IT STILL APPEARS FAVORABLE FOR LGT
SNOW AND A PERIOD OF MODERATE SNOW MAY ACCOMPANY THE SYSTEM AROUND
DAYBREAK MON FOR A FEW HOURS...WITH LIGHT ACCUMULATIONS. CIGS SHUD
LOWER QUICKLY WITH THE STEADIER SNOW...AND MAY TOUCH IFR CONDS AS
THE GRADIENT SLACKENS.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH FOR WINDS THRU THE PERIOD.
* MEDIUM FOR PRECIP TIMING/DURATION/CIGS/VIS MONDAY MORNING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MAINLY VFR CONDS. PATCHY MVFR CIGS.
TUESDAY...CHANCE OF RAIN TUESDAY AFTERNOON. RAIN LIKELY/THUNDER
POSSIBLE AT NIGHT. MVFR/IFR POSSIBLE. BREEZY SOUTHEAST WINDS.
WEDNESDAY...SLIGHT CHANCE OF SHOWERS WITH MVFR EARLY. GUSTY WEST-
SOUTHWEST WINDS.
THURSDAY...SLIGHT CHANCE OF SHOWERS. MVFR POSSIBLE.
FRIDAY...VFR.
SATURDAY...VFR.
BEACHLER
&&
.MARINE...
425 AM CDT
A SURFACE RIDGE OF HIGH PRESSURE WILL SHIFT OVER SOUTHERN CANADA AND
THE UPPER GREAT LAKES THROUGH MONDAY. THIS WILL RESULT IN A
CONTINUED PERIOD OF NORTHERLY WINDS UP TO AROUND 20 KT TODAY AND
TONIGHT. THEREFORE...EXPECT WAVES OF 3 TO 5 FEET TO CONTINUE FOR THE
NEAR SHORE WATERS OF NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA.
ANOTHER STORM SYSTEM IS EXPECTED TO IMPACT THE WESTERN GREAT LAKES
REGION LATE TUESDAY THROUGH WEDNESDAY. THE SURFACE LOW IS FORECAST
TO TRACK EAST-NORTHEASTWARD FROM THE PLAINS TO THE UPPER GREAT LAKES
BY WEDNESDAY MORNING. THIS LOOKS TO RESULT IN A PERIOD OF INCREASING
SOUTHEASTERLY WINDS OF 25 TO 30 KT TUESDAY NIGHT...FOLLOWED BY A
PERIOD OF STRONG WEST-SOUTHWESTERLY WINDS ON WEDNESDAY. GALE FORCE
WINDS ARE POSSIBLE ON WEDNESDAY...ESPECIALLY ACROSS THE ILLINOIS
AND INDIANA NEAR SHORES. WINDS WILL THEN SHIFT BACK OUT OF THE NORTH
BY LATE WEEK AS A REINFORCING COLD FRONT DROPS SOUTHWARD DOWN THE
LAKE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
635 PM CDT MON MAR 23 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 339 PM CDT MON MAR 23 2015
OVERNIGHT FORECAST BECOMING COMPLICATED BY STRATUS DEVELOPMENT
TODAY AND MUCH COOLER HIGHS THAN ANTICIPATED. WITH NORTHEAST FLOW
AT THE SURFACE...DEW POINTS WILL REMAIN IN THE MID TO UPPER 20S FOR
THE OVERNIGHT HOURS UNTIL WINDS BECOME MORE SOUTHEAST AFTER 06Z. THIS
SHOULD ACT TO CAP ANY COOLING OVER THE SOUTH AND ACTUALLY RESULT IN
A EITHER STEADY OR A SLOW RISE IN TEMPERATURE AND DEW POINTS OVER
THE REGION BY 12Z. SOUNDINGS CONTINUE TO SHOW DRY AIR IN THE
FORECAST AREA WILL NEED TO BE OVERCOME PRIOR TO ANY PRECIPITATION
REACHING THE GROUND. THE GFS/NAM ARE MOST AGGRESSIVE WITH
SATURATION...THOUGH THE GFS HAS BACKED OFF A BIT ON THE ONSET OF
PRECIPITATION. THE EURO HAS BEEN SIMILAR IN THE PAST 2 MODEL
SOLUTIONS IN DELAYING MOST OF THE PRECIPITATION WITH THE EXCEPTION
OF THE FAR SOUTH UNTIL 09-12Z. AFTER LOOKING AT THE HRRR AND SEEING
THAT THE MESO SCALE MODELS ARE CONTINUING WITH AN EARLIER
ONSET...HAVE TAKEN A BLEND OF THE EURO/GFS SOLUTIONS. BACKED OFF A
BIT ON THE ONSET FROM THE PREVIOUS PACKAGE AND ALSO HAVE TRIMMED
BACK THUNDER CHANCES OVER THE SOUTH WITH ONLY THE FAR SOUTH LIKELY
TO SEE ANY ISO THUNDER THROUGH 12Z. THOUGH MOST OF ANY PRECIPITATION
THAT FALLS SHOULD REMAIN LIQUID...THERE IS STILL A RISK FOR SOME
LIGHT FREEZING RAIN ON THE NORTHERN EDGE OF THE PRECIPITATION SHIELD
AND OVER SOUTHEAST SECTIONS AS THE PRECIPITATION COMMENCES. THIS IS
MAINLY DUE TO TODAYS LACK OF DAYTIME HEATING...THE RELATIVELY DRY
AIR AND THE EXPECTATION THAT OVERNIGHT LOWS OVER THOSE AREAS WILL
LIKELY BE AT OR JUST BELOW THE FREEZING MARK BY SUNRISE. WITH
LIMITED MOISTURE EXPECTED OVERNIGHT...WILL NOT HAVE ANY HEADLINES AT
THIS TIME DUE TO THE POTENTIAL OF MAINLY VERY LIGHT ACCUMULATIONS OF
A HUNDREDTH OR TWO. LOWS WILL RANGE FROM THE 20S NORTHEAST TO THE
LOWER TO MID 30S OVER THE SOUTHWEST.
.LONG TERM /TUESDAY THROUGH MONDAY/...
ISSUED AT 339 PM CDT MON MAR 23 2015
PRECIPITATION EXPECTED TO BE ONGOING ACROSS THE SOUTHERN HALF OF
THE CWA AND WILL CONTINUE TO SPREAD NORTH ACROSS THE REMAINDER OF
THE CWA TUESDAY AS A DOUBLE-BARRELED UPPER LEVEL SYSTEM IMPACTS
THE REGION. INITIAL WAVE ROTATING THROUGH THE BASE OF THE OTHER
LOW TO SWING THROUGH IOWA LATE TUESDAY INTO TUESDAY NIGHT BRINGING
THE MAJORITY OF THE CHANGES OF PRECIPITATION THROUGH WEDNESDAY
NIGHT. WARM FRONT ALOFT TO LIFT NORTHWARD THROUGH THE CWA...WAA
AND MOISTURE ADVECTION IN PLACE ACROSS MUCH OF THE AREA TUESDAY.
STILL EXPECTING A MAIN AREA OF WAA PRECIP TO LIFT THROUGH THE CWA
TUESDAY MORNING...WITH A DRY PERIOD ACROSS PORTIONS OF
CENTRAL/SOUTHERN IOWA MOST LIKELY LATER TUESDAY MORNING INTO EARLY
AFTERNOON. SHOWER AND POTENTIAL ISOLATED THUNDERSTORM
REDEVELOPMENT EXPECTED IN THE AFTERNOON HOURS...AS THE MAIN UPPER
LOW MOVES OVERHEAD. WIDESPREAD PRECIPITATION EXPECTED ACROSS THE
ENTIRE CWA WITH THE MAIN LOW MOVING THROUGH...WITH PRECIPITATION
EXPECTED TO TAPER OFF FROM WEST TO EAST TUESDAY EVENING AS THE
UPPER LOW PUSHES EAST NORTHEAST INTO THE GREAT LAKES REGION.
CONTINUE TO SEE CHANCES FOR ELEVATED THUNDER ACROSS THE SOUTHERN
HALF OF THE CWA TUESDAY INTO TUESDAY EVENING. DYNAMIC COOLING OF
THE COLUMN WITH MORE INTENSE PRECIPITATION AREAS SHOULD ALLOW FOR
A MIXING OF RAIN/SNOW OR COMPLETE CHANGEOVER TO ALL SNOW ACROSS
THE FAR NORTHERN AREAS LATE TUESDAY AFTERNOON INTO TUESDAY
EVENING. A QUICK INCH OR TWO OF SNOW IS POSSIBLE BEFORE
PRECIPITATION CHANCES TAPER OFF TUESDAY EVENING. WIDESPREAD HALF
INCH QPF AMOUNTS CAN BE EXPECTED FROM THIS SYSTEM.
SECOND LOBE OF THE UPPER LEVEL SYSTEM TO DROP SOUTHWARD TOWARD THE
AREA WEDNESDAY...WITH A COLD FRONT DROPPING THROUGH THE CWA. MAY
HAVE SOME PRECIPITATION FORM ALONG AND AHEAD OF THE COLD FRONT BY
LATE AFTERNOON ACROSS FAR SOUTHERN IOWA. ARCTIC HIGH PRESSURE TO
THEN BUILD INTO THE REGION FOR THURSDAY INTO FRIDAY...WITH H85
TEMPS DROPPING INTO THE TEENS BELOW CELSIUS. THIS SHOULD ALLOW
TEMPS ACROSS THE AREA TO REMAIN WELL BELOW AVERAGE TO CLOSE OUT
THE WEEK. THE HIGH QUICKLY SHOVES SOUTHEAST THROUGH AS THE THERMAL
RIDGE BUILDS IN ALOFT OVER THE UPCOMING WEEKEND WITH UPPER LEVEL
RIDGING BUILDING INTO THE CENTRAL US. THEREFORE TEMPS SHOULD WARM
BACK TO NEAR THE SEASONAL AVERAGES OR ABOVE BY SUNDAY AND INTO
EARLY NEXT WEEK.
&&
.AVIATION...24/00Z
ISSUED AT 635 PM CDT MON MAR 23 2015
SURFACE LOW AND WARM FRONTAL BOUNDARY WILL REMAIN SOUTH OF THE
STATE FOR DURATION OF FORECAST. THEREFORE...ANTICIPATE
STRENGTHENING EASTERLY FLOW...ESPECIALLY INTO TUESDAY AS THE LOW
PASSES ACROSS KANSAS THEN MISSOURI. ALONG WITH THE EASTERLY
FLOW...LOW MVFR TO IFR CEILINGS ARE EXPECTED FOR THE DURATION OF
THE FORECAST AS WELL AS LOW LEVELS REMAIN MOIST. WITH THE INCREASE
IN FORCING BY DAYBREAK WITH WARM ADVECTION...PRECIPITATION WILL
SPREAD INTO SOUTHERN IOWA AND CONTINUE TO EXPAND NORTHEAST THROUGH
THE DAY. MOSTLY RAIN IS EXPECTED ALTHOUGH A BRIEF PERIOD OF MIXED
PRECIPITATION WILL BE POSSIBLE AT THE ONSET BEFORE DAYTIME HEATING
HELPS TO TRANSITION PRECIPITATION TO ALL RAIN.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...BEERENDS
AVIATION...COGIL
AREA FORECAST DISCUSSION
NWS JACKSON KY
644 PM EDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 645 PM EDT SUN MAR 22 2015
BUMPED UP SKY COVER TO BETTER REFLECT CURRENT CONDITIONS...AND
ALIGNED TEMPS/DEW POINTS WITH MOST RECENT OBS. KEEPING ON EYE ON
SOME LIGHT RADAR RETURNS...BUT CURRENT THINKING IS THAT ANY
MEASURABLE PRECIP WILL STAY SOUTH OF THE AREA TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 400 PM EDT SUN MAR 22 2015
19Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING IN FROM THE NORTH
WITH LOW PRESSURE SKIRTING THE BOUNDARY JUST TO OUR SOUTH. ON
RADAR...LIGHT RETURNS KEEP TRYING TO SNEAK ACROSS OUR BORDER WITH
TENNESSEE...BUT SO FAR THERE HAVE NOT BEEN ANY OBS OR REPORTS OF
ANYTHING REACHING THE GROUND IN KENTUCKY. THICKENING HIGH CLOUDS
ARE SEEPING NORTH ASSOCIATED WITH THE SOUTHERN SYSTEMS...BUT ONLY
RECENTLY HAVE THE CLOUDS GOTTEN OPAQUE ENOUGH TO BLOCK THE SUN.
WITH THE FILTERED SUNSHINE...TEMPERATURES WERE ABLE TO CLIMB INTO
THE LOW 60S ACROSS THE SOUTH AND THE MID 50S TO THE NORTH.
DEWPOINTS BASICALLY HELD STEADY THROUGH THE DAY SO THAT THEY STILL
VARY FROM THE UPPER 20S IN THE NORTH TO LOW 40S IN THE SOUTH.
MEANWHILE...WINDS REMAIN MAINLY FROM THE NORTHEAST AT 5 TO 10 KTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM.
THEY ALL DEPICT A WEAK SOUTHERN STREAM TROUGH PASSING THROUGH THE
DEEP SOUTH WHILE SOME ENERGY SLIPS INTO THE OHIO VALLEY LATE
MONDAY IN THE NORTHERN STREAM. HEIGHTS WILL GRADUALLY RISE THROUGH
TUESDAY MORNING AS THE SOUTHERN TROUGH DEPARTS...EVEN WITH THE
NORTHERN ENERGY SCRAPING BY MONDAY NIGHT. GIVEN THE GENERAL MODEL
AGREEMENT HAVE FAVORED THE HIGHER RESOLUTION NAM12 AND HRRR FOR WX
DETAILS THROUGH THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE THE SMALL POTENTIAL FOR SPRINKLES OR
LIGHT RAIN IN FAR SOUTHERN PARTS OF THE CWA TONIGHT. OTHERWISE
PARTLY TO MOSTLY CLOUDY SKIES WILL DOMINATE HELPING TO KEEP THE
LID ON THE WORST OF THE COOLING OVERNIGHT. FOR MONDAY...HIGH
CLOUDS WILL CONTINUE TO PLAGUE THE AREA AS WE WILL BE BETWEEN THE
SYSTEMS ON OUR FRINGES. LATER THAT NIGHT THERE WILL BE A SMALL
CHANCE FOR RAIN IN THE NORTHERNMOST PARTS OF EASTERN KENTUCKY AS
A DEVELOPING...BUT MOSTLY DRY...WARM FRONT LIFTS THROUGH THE
AREA.
ONCE AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR T/TD/WINDS
INTO MONDAY MORNING AND THE SUPERBLEND THEREAFTER. DID MAKE MINOR
POINT AND TERRAIN BASED ADJUSTMENTS TO TEMPS THROUGH THE PERIOD.
AS FOR POPS...ENDED UP IN LINE WITH ALL MOS GUIDANCE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 PM EDT SUN MAR 22 2015
AN UPPER LEVEL TROUGH DIGGING INTO THE NORTHERN PLAINS WILL DRIVE A
WARM FRONT NORTHWARD ACROSS OUR AREA ON TUESDAY. WHILE MOISTURE IS
MEAGER WITH THIS FRONT...MODELS CONTINUE TO INDICATE THE POTENTIAL
FOR A FEW SHOWERS. THIS WARM FRONT WILL SHIFT NORTH OF OUR AREA
TUESDAY NIGHT. A WEAKENING SFC COLD FRONT ASSOCIATED WITH LOW
PRESSURE OVER THE GREAT LAKES WILL DROP DOWN ACROSS THE AREA ON
WEDNESDAY WHILE THE SUPPORTING UPPER LEVEL TROUGH EVENTUALLY OUT
RUNS ALL OF ITS SFC FEATURES. WHILE MOISTURE REMAINS MEAGER WITH
THIS SYSTEM...ISOLATED TO SCATTERED SHOWERS AND PERHAPS A STRAY
THUNDERSTORM CAN NOT BE RULED OUT DURING THE DAY WEDNESDAY.
ANOTHER MORE SUBSTANTIAL...DEEPER TROUGH WILL REENERGIZE THE
BOUNDARY LEFT IN PLACE ACROSS THE REGION WEDNESDAY NIGHT INTO
THURSDAY. THERE WILL BE ENOUGH ENERGY WITH THIS SECOND UPPER TROUGH
THAT WE CAN EXPECT NUMEROUS SHOWERS TO DEVELOP ACROSS OUR AREA AS
ITS INDUCED SFC LOW DEVELOPS AND PUSHES UP THE MID MISSISSIPPI...
LOWER OHIO VALLEY. THIS WILL ALLOW THE SFC FRONT TO REORGANIZE AND
BEGIN ITS PUSH EASTWARD AGAIN. SFC BASED INSTABILITY DOES NOT LOOK
AS IMPRESSIVE BUT SHOULD BE ENOUGH TO KEEP MENTION OF A FEW
THUNDERSTORMS IN THE FORECAST. WHILE THE ENDS GENERALLY REMAIN THE
SAME WITH RESPECT TO SENSIBLE WEATHER...BOTH THE GFS AND ECMWF ARE
IN DECENT AGREEMENT WITH THIS SCENARIO...THE GFS DOES APPEAR MORE
AGGRESSIVE AND WELL DEFINED WITH ALL THE SFC FEATURES THAN THE
ECMWF. IN ADDITION...MODELS SEEM TO BE TRENDING A BIT SLOWER
OVERALL WITH THE EVOLUTION OF THIS PHASE OF THE EXTENDED.
IN ADDITION...OUR PATTERN TURNS MUCH COLDER FROM THURSDAY NIGHT INTO
THE WEEKEND AS A LARGE CANADIAN SFC HIGH PRESSURE SYSTEM SETTLES
OVER THE REGION. UPPER LEVEL ENERGY CONTINUES TO DIG IN FROM THE
NORTHWEST...DEEPENING THE TROUGH OVER THE OHIO AND TENNESSEE
VALLEYS. DEEPER MOISTURE WILL EXIT WITH THE FRONT BY THURSDAY
NIGHT...BUT AN UNSTABLE BOUNDARY LAYER WILL REMAIN IN PLACE AS THE
CORE OF THE TROUGH SWINGS THROUGH ON FRIDAY. WITH STEEP LAPSE
RATES...A FEW RAIN SHOWERS CAN NOT BE RULED OUT. IF FREEZING LEVELS
DROP LOW ENOUGH WE COULD EVEN SEE SOME WET SNOW MIX IN OVER THE
HIGHER TERRAIN. STILL SOME UNCERTAINTY IN THE MODELS WITH THE AMOUNT
OF MOISTURE AND COLD AIR COMING IN...BUT THERE SEEMS TO BE A GENERAL
CONSENSUS OF H850 TEMPS DROPPING TO AROUND -10C OVERHEAD BY SATURDAY
MORNING. THIS COULD RESULT IN A WIDESPREAD FREEZE SATURDAY MORNING
IF SFC HIGH PRESSURE BECOMES MORE CENTERED OVER EASTERN KENTUCKY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 645 PM EDT SUN MAR 22 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. A SURFACE HIGH
PUSHES SOUTH TONIGHT AND INTO MONDAY AS LOW PRESSURE SCOOTS PAST
TO THE SOUTH. HIGH CLOUDS OF VARYING OPACITY FROM THE SOUTHERN LOW
WILL COVER THE REGION DURING THIS TIME. WINDS THROUGH MUCH OF
THE TAF PERIOD WILL REMAIN GENERALLY LIGHT FROM THE NORTH TO
NORTHEAST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...ABE/RAY
AVIATION...JVM/GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
400 PM EDT SUN MAR 22 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 400 PM EDT SUN MAR 22 2015
19Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING IN FROM THE NORTH
WITH LOW PRESSURE SKIRTING THE BOUNDARY JUST TO OUR SOUTH. ON
RADAR...LIGHT RETURNS KEEP TRYING TO SNEAK ACROSS OUR BORDER WITH
TENNESSEE...BUT SO FAR THERE HAVE NOT BEEN ANY OBS OR REPORTS OF
ANYTHING REACHING THE GROUND IN KENTUCKY. THICKENING HIGH CLOUDS
ARE SEEPING NORTH ASSOCIATED WITH THE SOUTHERN SYSTEMS...BUT ONLY
RECENTLY HAVE THE CLOUDS GOTTEN OPAQUE ENOUGH TO BLOCK THE SUN.
WITH THE FILTERED SUNSHINE...TEMPERATURES WERE ABLE TO CLIMB INTO
THE LOW 60S ACROSS THE SOUTH AND THE MID 50S TO THE NORTH.
DEWPOINTS BASICALLY HELD STEADY THROUGH THE DAY SO THAT THEY STILL
VARY FROM THE UPPER 20S IN THE NORTH TO LOW 40S IN THE SOUTH.
MEANWHILE...WINDS REMAIN MAINLY FROM THE NORTHEAST AT 5 TO 10 KTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM.
THEY ALL DEPICT A WEAK SOUTHERN STREAM TROUGH PASSING THROUGH THE
DEEP SOUTH WHILE SOME ENERGY SLIPS INTO THE OHIO VALLEY LATE
MONDAY IN THE NORTHERN STREAM. HEIGHTS WILL GRADUALLY RISE THROUGH
TUESDAY MORNING AS THE SOUTHERN TROUGH DEPARTS...EVEN WITH THE
NORTHERN ENERGY SCRAPING BY MONDAY NIGHT. GIVEN THE GENERAL MODEL
AGREEMENT HAVE FAVORED THE HIGHER RESOLUTION NAM12 AND HRRR FOR WX
DETAILS THROUGH THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE THE SMALL POTENTIAL FOR SPRINKLES OR
LIGHT RAIN IN FAR SOUTHERN PARTS OF THE CWA TONIGHT. OTHERWISE
PARTLY TO MOSTLY CLOUDY SKIES WILL DOMINATE HELPING TO KEEP THE
LID ON THE WORST OF THE COOLING OVERNIGHT. FOR MONDAY...HIGH
CLOUDS WILL CONTINUE TO PLAGUE THE AREA AS WE WILL BE BETWEEN THE
SYSTEMS ON OUR FRINGES. LATER THAT NIGHT THERE WILL BE A SMALL
CHANCE FOR RAIN IN THE NORTHERNMOST PARTS OF EASTERN KENTUCKY AS
A DEVELOPING...BUT MOSTLY DRY...WARM FRONT LIFTS THROUGH THE
AREA.
ONCE AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR T/TD/WINDS
INTO MONDAY MORNING AND THE SUPERBLEND THEREAFTER. DID MAKE MINOR
POINT AND TERRAIN BASED ADJUSTMENTS TO TEMPS THROUGH THE PERIOD.
AS FOR POPS...ENDED UP IN LINE WITH ALL MOS GUIDANCE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 PM EDT SUN MAR 22 2015
AN UPPER LEVEL TROUGH DIGGING INTO THE NORTHERN PLAINS WILL DRIVE A
WARM FRONT NORTHWARD ACROSS OUR AREA ON TUESDAY. WHILE MOISTURE IS
MEAGER WITH THIS FRONT...MODELS CONTINUE TO INDICATE THE POTENTIAL
FOR A FEW SHOWERS. THIS WARM FRONT WILL SHIFT NORTH OF OUR AREA
TUESDAY NIGHT. A WEAKENING SFC COLD FRONT ASSOCIATED WITH LOW
PRESSURE OVER THE GREAT LAKES WILL DROP DOWN ACROSS THE AREA ON
WEDNESDAY WHILE THE SUPPORTING UPPER LEVEL TROUGH EVENTUALLY OUT
RUNS ALL OF ITS SFC FEATURES. WHILE MOISTURE REMAINS MEAGER WITH
THIS SYSTEM...ISOLATED TO SCATTERED SHOWERS AND PERHAPS A STRAY
THUNDERSTORM CAN NOT BE RULED OUT DURING THE DAY WEDNESDAY.
ANOTHER MORE SUBSTANTIAL...DEEPER TROUGH WILL REENERGIZE THE
BOUNDARY LEFT IN PLACE ACROSS THE REGION WEDNESDAY NIGHT INTO
THURSDAY. THERE WILL BE ENOUGH ENERGY WITH THIS SECOND UPPER TROUGH
THAT WE CAN EXPECT NUMEROUS SHOWERS TO DEVELOP ACROSS OUR AREA AS
ITS INDUCED SFC LOW DEVELOPS AND PUSHES UP THE MID MISSISSIPPI...
LOWER OHIO VALLEY. THIS WILL ALLOW THE SFC FRONT TO REORGANIZE AND
BEGIN ITS PUSH EASTWARD AGAIN. SFC BASED INSTABILITY DOES NOT LOOK
AS IMPRESSIVE BUT SHOULD BE ENOUGH TO KEEP MENTION OF A FEW
THUNDERSTORMS IN THE FORECAST. WHILE THE ENDS GENERALLY REMAIN THE
SAME WITH RESPECT TO SENSIBLE WEATHER...BOTH THE GFS AND ECMWF ARE
IN DECENT AGREEMENT WITH THIS SCENARIO...THE GFS DOES APPEAR MORE
AGGRESSIVE AND WELL DEFINED WITH ALL THE SFC FEATURES THAN THE
ECMWF. IN ADDITION...MODELS SEEM TO BE TRENDING A BIT SLOWER
OVERALL WITH THE EVOLUTION OF THIS PHASE OF THE EXTENDED.
IN ADDITION...OUR PATTERN TURNS MUCH COLDER FROM THURSDAY NIGHT INTO
THE WEEKEND AS A LARGE CANADIAN SFC HIGH PRESSURE SYSTEM SETTLES
OVER THE REGION. UPPER LEVEL ENERGY CONTINUES TO DIG IN FROM THE
NORTHWEST...DEEPENING THE TROUGH OVER THE OHIO AND TENNESSEE
VALLEYS. DEEPER MOISTURE WILL EXIT WITH THE FRONT BY THURSDAY
NIGHT...BUT AN UNSTABLE BOUNDARY LAYER WILL REMAIN IN PLACE AS THE
CORE OF THE TROUGH SWINGS THROUGH ON FRIDAY. WITH STEEP LAPSE
RATES...A FEW RAIN SHOWERS CAN NOT BE RULED OUT. IF FREEZING LEVELS
DROP LOW ENOUGH WE COULD EVEN SEE SOME WET SNOW MIX IN OVER THE
HIGHER TERRAIN. STILL SOME UNCERTAINTY IN THE MODELS WITH THE AMOUNT
OF MOISTURE AND COLD AIR COMING IN...BUT THERE SEEMS TO BE A GENERAL
CONSENSUS OF H850 TEMPS DROPPING TO AROUND -10C OVERHEAD BY SATURDAY
MORNING. THIS COULD RESULT IN A WIDESPREAD FREEZE SATURDAY MORNING
IF SFC HIGH PRESSURE BECOMES MORE CENTERED OVER EASTERN KENTUCKY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 230 PM EDT SUN MAR 22 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. A SURFACE HIGH
PUSHES SOUTH TONIGHT AND INTO MONDAY AS LOW PRESSURE SCOOTS PAST
TO THE SOUTH. HIGH CLOUDS OF VARYING OPACITY FROM THE SOUTHERN LOW
WILL COVER THE REGION DURING THIS TIME. WINDS THROUGH MUCH OF
THE TAF PERIOD WILL REMAIN GENERALLY LIGHT FROM THE NORTH TO
NORTHEAST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...ABE/RAY
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
159 AM EDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 158 AM EDT SUN MAR 22 2015
UPDATED GRIDS WITH LATEST OBS AND TRENDS. DID KEPT GENERALLY
TRENDS IN TEMPS AS IS AS DRY COLD FRONT CONTINUES TO PUSH THROUGH
THE REGION TONIGHT. OPTED TO KEEP PATCHY VALLEY FOG ACROSS
PORTIONS OF THE REGION GIVEN THAT EKQ SAW A SLIGHT DROP IN VIS AT
5Z. NO MAJOR CHANGES NEEDED THIS UPDATE.
UPDATE ISSUED AT 1100 PM EDT SAT MAR 21 2015
HOURLY GRIDS HAVE BEEN UPDATED TO ACCOUNT FOR THE LATEST
OBSERVATIONS AND THE DRY COLD FRONT CROSSING THE AREA. THIS
FRONTAL PASSAGE SHOULD LEAD TO ENOUGH MIXING OF THE DECOUPLED
VALLEYS IN THE SOUTHEAST FOR AT LEAST A COUPLE OF HOURS AS IT
MOVES THROUGH...BEFORE TEMPS AGAIN DROP OFF LATE TONIGHT BEHIND
THE FRONT. THE HOURLY TEMPERATURES HAVE BEEN BLENDED TO THE
PREVIOUS CURVED AFTER 3 AM TO ACCOUNT FOR THIS EXPECTATION.
UPDATE ISSUED AT 810 PM EDT SAT MAR 21 2015
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS
AND SATELLITE IMAGERY. THE COLD FRONT THAT IS LACKING IN LOW LEVEL
MOISTURE IS DROPPING INTO THE NORTHERN PART OF THE CWA ATTM. THIS
FRONT WILL DROP SOUTH ACROSS THE REMAINDER OF THE CWA DURING THE
REST OF THIS EVENING AND INTO THE OVERNIGHT HOURS. THIS FRONT WILL
BRING LITTLE MORE THAN A SHIFT IN WINDS FROM THE WEST OR
SOUTHWEST TO THE NORTH AND NORTHEAST ON RIDGETOPS AND IN EXPOSED
LOCATIONS. CIRRUS ASSOCIATED WITH A SHORTWAVE WORKING FROM THE
SOUTHERN PLAINS TOWARD THE MS VALLEY REGION CONTINUES TO MOVE
OVERHEAD AS IT WORKS AROUND RIDGING EXTENDING FROM THE GULF OF
MEXICO INTO THE SOUTHEAST. THERE IS ADDITIONAL CIRRUS PASSING BY
IN THE WEST TO NORTHWEST FLOW ALOFT. CLOUD COVER WAS INCREASED
OVERNIGHT INTO SUNDAY AS THE CIRRUS HAS BEEN RATHER THICK AND
MODELS INDICATE IT MAY GET THICKER. SOME MID CLOUDS WILL ALSO PASS
BY FROM TIME TO TIME ON SUNDAY AS THE SHORTWAVE EJECTS INTO THE
SOUTHEASTERN STATES.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 320 PM EDT SAT MAR 21 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE NOSING DEEPER INTO EAST
KENTUCKY KEEPING THE SKIES MOSTLY CLEAR...ASIDE FROM A SOME HIGH
CLOUDS SEEPING NORTH FROM LOW PRESSURE WELL TO THE SOUTHWEST OF
THE AREA. DESPITE THE HIGH PRESSURE AND RETURNING SUNSHINE...
DEWPOINTS REMAIN IN THE UPPER 30S AND LOWER 40S KEEPING THE RH
AROUND 50 PERCENT FOR MUCH OF THE AREA. MEANWHILE...TEMPERATURES
ARE STILL CATCHING UP TO FORECAST HIGHS WITH A COUPLE OF HOURS OF
CLIMBING YET TO GO...RANGING FROM LOW 60S IN THE SOUTH TO THE MID
50S IN THE NORTH. WINDS ARE GENERALLY LIGHT FROM THE SOUTHWEST...
THOUGH ON THE NORTHEAST FRINGE OF THE HIGH PRESSURE SYSTEM THERE
HAVE BEEN A FEW GUSTS TO BETWEEN 15 AND 20 KTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST AS THEY DEPICT SOUTHERN STREAM ENERGY
BRUSHING BY KENTUCKY SUNDAY INTO MONDAY AS A BROAD TROUGH SLOWLY
MOVES THROUGH THE LOWER MISSISSIPPI VALLEY AND DEEP SOUTH. DURING
THIS TIME...EASTERN KENTUCKY WILL BE IN THE MIDST OF GENERALLY
BENIGN NORTHWEST FLOW IN WHICH ANY NORTHERN STREAM ENERGY STAYS
OFF TO THE NORTHEAST OF THE AREA. HEIGHTS DO FALL A BIT TONIGHT
INTO SUNDAY...BUT NOT DRAMATICALLY ENOUGH TO HAVE MUCH IMPACT ON
SENSIBLE WEATHER. GIVEN THE MODEL AGREEMENT...HAVE FAVORED THE
HIGHER RESOLUTION HRRR AND NAM12 FOR DETAILS THROUGH MONDAY
MORNING.
SENSIBLE WEATHER WILL FEATURE A COOL NIGHT DESPITE THE HIGH
CLOUDS DRIFTING IN FROM THE SOUTHWEST FROM A WEAK LOW NEAR THE
CENTRAL GULF COAST. AT THE SAME TIME...A COLD FRONT WILL SLIP
INTO AND THROUGH THE AREA WITH NOT MUCH IN THE WAY OF MOISTURE.
EXPECTING A DECENT START TO THE NIGHT FOR DECOUPLING AND
RADIATIONAL COOLING SO HAVE BROUGHT THE VALLEY TEMPS DOWN QUICKER
THAN THE MODELS WOULD SUGGEST. THE COLDER SPOTS MIX OUT IN THE
MORNING UNDER PARTIAL SUNSHINE SUNDAY WITH TEMPERATURES TOPPING
OUT A CATEGORY OR TWO BELOW TODAY/S HIGHS. WITH THE FRONT SOUTH OF
THE AREA FOR SUNDAY NIGHT WE WILL SEE SOME COLDER TEMPERATURES
ACROSS THE BOARD WITH SOME MINOR RIDGE TO VALLEY DIFFERENCES BY
DAWN. FOR TONIGHT...PATCHY FOG CAN BE EXPECTED IN THE VALLEYS
TOWARD DAWN WHILE ON SUNDAY NIGHT THERE MAY BE SOME PATCHES OF
FROST IN THE VALLEYS. HAVE LEFT THE FROST OUT OF THE ZFP FORECAST
FOR NOW...BUT DID ADD SOME TO THE GRIDS.
AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR T/TD/WINDS INTO
SUNDAY MORNING AND THE SUPERBLEND THEREAFTER. DID MAKE MINOR
POINT AND TERRAIN BASED ADJUSTMENTS TO TEMPS THROUGH THE PERIOD.
AS FOR POPS...KEPT THEM LOW...IN LINE WITH ALL MOS GUIDANCE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 235 PM EDT SAT MAR 21 2015
THE UPCOMING WEEK WILL FEATURE A TRANSITION FROM MEAN ZONAL FLOW
EARLY IN THE PERIOD TO A HIGHLY AMPLIFIED PATTERN BY THE END OF THE
PERIOD...WITH A DEEP TROUGH BECOMING ESTABLISHED IN THE EASTERN
UNITED STATES WITH A RIDGE IN THE WEST. THIS WILL RESULT IN A
SIGNIFICANT COOL DOWN AS WE HEAD INTO NEXT WEEKEND.
THE START OF THE FORECAST PERIOD WILL FEATURE A SHORT WAVE MOVING
THROUGH THE SOUTHERN STREAM ACROSS THE SOUTHEAST U.S. AND THEN OFF
THE ATLANTIC COAST. A WEAK SYSTEM WILL ALSO BE PASSING BY TO OUR
NORTH. OTHER THAN INCREASED CLOUDINESS THERE SHOULD BE LITTLE IMPACT
TO OUR AREA FROM THESE SYSTEMS. AS WE MOVE INTO MID WEEK A MUCH MORE
SIGNIFICANT SHORT WAVE WILL EMERGE INTO THE PLAINS. OUT AHEAD OF
THIS...A SURFACE WARM FRONT WILL MOVE ACROSS THE REGION WITH A
SIGNIFICANT SURGE OF WARM AIR MOVING INTO THE AREA AHEAD OF AN
ADVANCING COLD FRONT. AS THE UPPER SYSTEM AND SURFACE LOW MOVE INTO
THE GREAT LAKES REGION THE COLD FRONT WILL MOVE INTO ERN KY
WEDNESDAY NIGHT INTO THURSDAY. THIS WILL BRING A GOOD CHANCE OF
RAIN...WITH COOLER TEMPERATURES FOLLOWING. HAVE DECIDED TO ADD A
SLIGHT CHANCE OF THUNDER WITH THIS FRONTAL PASSAGE AS WELL..WHICH
WILL BE IN GOOD AGREEMENT WITH WFOS TO OUR WEST AND SOUTH.
A SECOND SURGE OF COLDER AIR LOOKS TO IMMEDIATELY FOLLOW THE INITIAL
COLD FRONTAL PASSAGE...AND THE POSSIBILITY EXISTS FOR SOME SNOW TO
AT LEAST MIX IN WITH RAIN IF ANY PRECIPITATION LINGERS INTO FRIDAY
NIGHT. THE OPERATIONAL GFS IS THE MOST AGGRESSIVE MODEL WITH THE
COLD AIR SURGE...WITH THE ECMWF AND GFS ENSEMBLE MEAN...WHILE
STILL COLD...NOT AS IMPRESSIVE...WITH 85H TEMPERATURES 5 DEGREES
OR SO WARMER. AT THIS POINT THERE IS STILL CONSIDERABLE
UNCERTAINTY REGARDING THE WEATHER DETAILS FOR THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 135 AM EDT SUN MAR 22 2015
DRY COLD FRONT CONTINUES TO DROP SOUTH ACROSS EASTERN KENTUCKY
TONIGHT. WINDS HAVE SHIFTED ACROSS NORTHERN PORTIONS OF THE CWA
GENERALLY ALONG AND NORTH OF THE MOUNTAIN PARKWAY THIS HOUR TO
GENERALLY LIGHT NORTH AND NORTHEAST WINDS. SOUTHERN SITES SUCH AS
SME COULD SEE SOME LIGHT MVFR FOG TONIGHT...HOWEVER CONFIDENCE IS
LOW AT THIS POINT DEPENDING ON HOW MUCH MIXING IF ANY OCCURS WITH
DRY COLD FRONT. THE GUIDANCE DID LEAN TOWARD JUST ABOVE OR RIGHT
AT MVFR...SO DID OPT TO LEAVE A WEAK MVFR SIGNAL IN THE SME TAF
STARTING AT 9Z. OTHERWISE VFR WILL BE THE STORY THROUGH THE TAF
PERIOD WITH GENERALLY HIGH TO POSSIBLY MID LEVEL CLOUDS. WINDS
THROUGH MUCH OF THE TAF PERIOD WILL REMAIN LIGHT OUT OF THE NORTH
TO NORTHEAST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
135 AM EDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 1100 PM EDT SAT MAR 21 2015
HOURLY GRIDS HAVE BEEN UPDATED TO ACCOUNT FOR THE LATEST
OBSERVATIONS AND THE DRY COLD FRONT CROSSING THE AREA. THIS
FRONTAL PASSAGE SHOULD LEAD TO ENOUGH MIXING OF THE DECOUPLED
VALLEYS IN THE SOUTHEAST FOR AT LEAST A COUPLE OF HOURS AS IT
MOVES THROUGH...BEFORE TEMPS AGAIN DROP OFF LATE TONIGHT BEHIND
THE FRONT. THE HOURLY TEMPERATURES HAVE BEEN BLENDED TO THE
PREVIOUS CURVED AFTER 3 AM TO ACCOUNT FOR THIS EXPECTATION.
UPDATE ISSUED AT 810 PM EDT SAT MAR 21 2015
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS
AND SATELLITE IMAGERY. THE COLD FRONT THAT IS LACKING IN LOW LEVEL
MOISTURE IS DROPPING INTO THE NORTHERN PART OF THE CWA ATTM. THIS
FRONT WILL DROP SOUTH ACROSS THE REMAINDER OF THE CWA DURING THE
REST OF THIS EVENING AND INTO THE OVERNIGHT HOURS. THIS FRONT WILL
BRING LITTLE MORE THAN A SHIFT IN WINDS FROM THE WEST OR
SOUTHWEST TO THE NORTH AND NORTHEAST ON RIDGETOPS AND IN EXPOSED
LOCATIONS. CIRRUS ASSOCIATED WITH A SHORTWAVE WORKING FROM THE
SOUTHERN PLAINS TOWARD THE MS VALLEY REGION CONTINUES TO MOVE
OVERHEAD AS IT WORKS AROUND RIDGING EXTENDING FROM THE GULF OF
MEXICO INTO THE SOUTHEAST. THERE IS ADDITIONAL CIRRUS PASSING BY
IN THE WEST TO NORTHWEST FLOW ALOFT. CLOUD COVER WAS INCREASED
OVERNIGHT INTO SUNDAY AS THE CIRRUS HAS BEEN RATHER THICK AND
MODELS INDICATE IT MAY GET THICKER. SOME MID CLOUDS WILL ALSO PASS
BY FROM TIME TO TIME ON SUNDAY AS THE SHORTWAVE EJECTS INTO THE
SOUTHEASTERN STATES.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 320 PM EDT SAT MAR 21 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE NOSING DEEPER INTO EAST
KENTUCKY KEEPING THE SKIES MOSTLY CLEAR...ASIDE FROM A SOME HIGH
CLOUDS SEEPING NORTH FROM LOW PRESSURE WELL TO THE SOUTHWEST OF
THE AREA. DESPITE THE HIGH PRESSURE AND RETURNING SUNSHINE...
DEWPOINTS REMAIN IN THE UPPER 30S AND LOWER 40S KEEPING THE RH
AROUND 50 PERCENT FOR MUCH OF THE AREA. MEANWHILE...TEMPERATURES
ARE STILL CATCHING UP TO FORECAST HIGHS WITH A COUPLE OF HOURS OF
CLIMBING YET TO GO...RANGING FROM LOW 60S IN THE SOUTH TO THE MID
50S IN THE NORTH. WINDS ARE GENERALLY LIGHT FROM THE SOUTHWEST...
THOUGH ON THE NORTHEAST FRINGE OF THE HIGH PRESSURE SYSTEM THERE
HAVE BEEN A FEW GUSTS TO BETWEEN 15 AND 20 KTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST AS THEY DEPICT SOUTHERN STREAM ENERGY
BRUSHING BY KENTUCKY SUNDAY INTO MONDAY AS A BROAD TROUGH SLOWLY
MOVES THROUGH THE LOWER MISSISSIPPI VALLEY AND DEEP SOUTH. DURING
THIS TIME...EASTERN KENTUCKY WILL BE IN THE MIDST OF GENERALLY
BENIGN NORTHWEST FLOW IN WHICH ANY NORTHERN STREAM ENERGY STAYS
OFF TO THE NORTHEAST OF THE AREA. HEIGHTS DO FALL A BIT TONIGHT
INTO SUNDAY...BUT NOT DRAMATICALLY ENOUGH TO HAVE MUCH IMPACT ON
SENSIBLE WEATHER. GIVEN THE MODEL AGREEMENT...HAVE FAVORED THE
HIGHER RESOLUTION HRRR AND NAM12 FOR DETAILS THROUGH MONDAY
MORNING.
SENSIBLE WEATHER WILL FEATURE A COOL NIGHT DESPITE THE HIGH
CLOUDS DRIFTING IN FROM THE SOUTHWEST FROM A WEAK LOW NEAR THE
CENTRAL GULF COAST. AT THE SAME TIME...A COLD FRONT WILL SLIP
INTO AND THROUGH THE AREA WITH NOT MUCH IN THE WAY OF MOISTURE.
EXPECTING A DECENT START TO THE NIGHT FOR DECOUPLING AND
RADIATIONAL COOLING SO HAVE BROUGHT THE VALLEY TEMPS DOWN QUICKER
THAN THE MODELS WOULD SUGGEST. THE COLDER SPOTS MIX OUT IN THE
MORNING UNDER PARTIAL SUNSHINE SUNDAY WITH TEMPERATURES TOPPING
OUT A CATEGORY OR TWO BELOW TODAY/S HIGHS. WITH THE FRONT SOUTH OF
THE AREA FOR SUNDAY NIGHT WE WILL SEE SOME COLDER TEMPERATURES
ACROSS THE BOARD WITH SOME MINOR RIDGE TO VALLEY DIFFERENCES BY
DAWN. FOR TONIGHT...PATCHY FOG CAN BE EXPECTED IN THE VALLEYS
TOWARD DAWN WHILE ON SUNDAY NIGHT THERE MAY BE SOME PATCHES OF
FROST IN THE VALLEYS. HAVE LEFT THE FROST OUT OF THE ZFP FORECAST
FOR NOW...BUT DID ADD SOME TO THE GRIDS.
AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR T/TD/WINDS INTO
SUNDAY MORNING AND THE SUPERBLEND THEREAFTER. DID MAKE MINOR
POINT AND TERRAIN BASED ADJUSTMENTS TO TEMPS THROUGH THE PERIOD.
AS FOR POPS...KEPT THEM LOW...IN LINE WITH ALL MOS GUIDANCE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 235 PM EDT SAT MAR 21 2015
THE UPCOMING WEEK WILL FEATURE A TRANSITION FROM MEAN ZONAL FLOW
EARLY IN THE PERIOD TO A HIGHLY AMPLIFIED PATTERN BY THE END OF THE
PERIOD...WITH A DEEP TROUGH BECOMING ESTABLISHED IN THE EASTERN
UNITED STATES WITH A RIDGE IN THE WEST. THIS WILL RESULT IN A
SIGNIFICANT COOL DOWN AS WE HEAD INTO NEXT WEEKEND.
THE START OF THE FORECAST PERIOD WILL FEATURE A SHORT WAVE MOVING
THROUGH THE SOUTHERN STREAM ACROSS THE SOUTHEAST U.S. AND THEN OFF
THE ATLANTIC COAST. A WEAK SYSTEM WILL ALSO BE PASSING BY TO OUR
NORTH. OTHER THAN INCREASED CLOUDINESS THERE SHOULD BE LITTLE IMPACT
TO OUR AREA FROM THESE SYSTEMS. AS WE MOVE INTO MID WEEK A MUCH MORE
SIGNIFICANT SHORT WAVE WILL EMERGE INTO THE PLAINS. OUT AHEAD OF
THIS...A SURFACE WARM FRONT WILL MOVE ACROSS THE REGION WITH A
SIGNIFICANT SURGE OF WARM AIR MOVING INTO THE AREA AHEAD OF AN
ADVANCING COLD FRONT. AS THE UPPER SYSTEM AND SURFACE LOW MOVE INTO
THE GREAT LAKES REGION THE COLD FRONT WILL MOVE INTO ERN KY
WEDNESDAY NIGHT INTO THURSDAY. THIS WILL BRING A GOOD CHANCE OF
RAIN...WITH COOLER TEMPERATURES FOLLOWING. HAVE DECIDED TO ADD A
SLIGHT CHANCE OF THUNDER WITH THIS FRONTAL PASSAGE AS WELL..WHICH
WILL BE IN GOOD AGREEMENT WITH WFOS TO OUR WEST AND SOUTH.
A SECOND SURGE OF COLDER AIR LOOKS TO IMMEDIATELY FOLLOW THE INITIAL
COLD FRONTAL PASSAGE...AND THE POSSIBILITY EXISTS FOR SOME SNOW TO
AT LEAST MIX IN WITH RAIN IF ANY PRECIPITATION LINGERS INTO FRIDAY
NIGHT. THE OPERATIONAL GFS IS THE MOST AGGRESSIVE MODEL WITH THE
COLD AIR SURGE...WITH THE ECMWF AND GFS ENSEMBLE MEAN...WHILE
STILL COLD...NOT AS IMPRESSIVE...WITH 85H TEMPERATURES 5 DEGREES
OR SO WARMER. AT THIS POINT THERE IS STILL CONSIDERABLE
UNCERTAINTY REGARDING THE WEATHER DETAILS FOR THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 135 AM EDT SUN MAR 22 2015
DRY COLD FRONT CONTINUES TO DROP SOUTH ACROSS EASTERN KENTUCKY
TONIGHT. WINDS HAVE SHIFTED ACROSS NORTHERN PORTIONS OF THE CWA
GENERALLY ALONG AND NORTH OF THE MOUNTAIN PARKWAY THIS HOUR TO
GENERALLY LIGHT NORTH AND NORTHEAST WINDS. SOUTHERN SITES SUCH AS
SME COULD SEE SOME LIGHT MVFR FOG TONIGHT...HOWEVER CONFIDENCE IS
LOW AT THIS POINT DEPENDING ON HOW MUCH MIXING IF ANY OCCURS WITH
DRY COLD FRONT. THE GUIDANCE DID LEAN TOWARD JUST ABOVE OR RIGHT
AT MVFR...SO DID OPT TO LEAVE A WEAK MVFR SIGNAL IN THE SME TAF
STARTING AT 9Z. OTHERWISE VFR WILL BE THE STORY THROUGH THE TAF
PERIOD WITH GENERALLY HIGH TO POSSIBLY MID LEVEL CLOUDS. WINDS
THROUGH MUCH OF THE TAF PERIOD WILL REMAIN LIGHT OUT OF THE NORTH
TO NORTHEAST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1231 PM EDT SUN MAR 22 2015
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO INTENSIFY ACROSS THE MARITIMES
TODAY AND TONIGHT. CANADIAN HIGH PRESSURE WILL BUILD EAST TOWARD
THE REGION LATER MONDAY THROUGH TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1230 PM UPDATE: LOW PRESSURE NEAR THE EASTERN TIP OF NOVA SCOTIA
WILL CONTINUE TO INTENSIFY AS IT ROTATES NORTHWEST ACROSS THE
CANADIAN MARITIMES TODAY. A STRONG PRESSURE GRADIENT ACROSS THE
AREA WILL RESULT IN GUSTY WEST WINDS TODAY ALONG WITH SOME LIGHT
SNOW ACROSS NORTHERN AREAS. WINDS COULD GUST AS HIGH AS 45 TO 50
MPH AT TIMES ESPECIALLY ACROSS THE HIGHER TERRAIN. ANY ADDITIONAL
SNOW ACCUMULATION WILL BE AN INCH OR LESS. THE BIGGER CONCERN WILL
BE AREAS OF BLOWING SNOW MAINLY ACROSS NORTHERN AREAS THAT WILL
ABRUPTLY REDUCE VISIBILITY AT TIMES ESPECIALLY ON NORTH-SOUTH
ROADS. FOR THIS REASON, WE WILL KEEP THE WINTER WEATHER ADVISORY
GOING TODAY. WILL ALSO KEEP THE WIND ADVISORY GOING ACROSS CENTRAL
AND DOWN EAST AREAS FOR TODAY. ALL-IN-ALL, THE CURRENT FORECAST
HAS THINGS COVERED QUITE NICELY AND NO SIGNIFICANT ADJUSTMENTS
WERE MADE TO THE FORECAST ON THIS UPDATE.
PREVIOUS DISCUSSION
OTHERWISE...LATEST HRRR SIM RADAR IMAGERY SHOWS MUCH OF THE
REMAINING PTN OF STEADY SN RETREATING INTO NRN NB BY LATE MORN.
HELD OFF FOR NOW TO ADJUSTING POPS DOWNWARD OVR THE FAR N...SINCE
LATEST 06Z SYNOPTIC MODELS STILL INDICATE A FEW HUNDREDTHS OF AN
IN OF QPF OVR THIS PTN OF THE FA BETWEEN 12 AND 18Z (8AM-2PM)
TODAY.
ORGNL DISC: LATEST RADAR IMAGERY SHOWS THE BACK EDGE OF STEADY
SNFL NOW SLIDING E OUT OF DOWNEAST AND CNTRL PTNS OF THE FA INTO
NB PROV... BUT STILL HOLDING ACROSS NRN AND ERN AROOSTOOK
COUNTY...AT LEAST FOR THE NEXT FEW HRS. AFTWRDS...WNW WINDS WILL
DRAMATICALLY INCREASE ACROSS ALL OF THE REGION FOLLOWING THE
PASSAGE OF AN ARCTIC FRONT WITHIN THE NEXT 1 TO 3 HRS. WIND GUSTS
WILL BE REACHING MID TO HIGH END WIND ADV CRITERIA BY AFTN.
HOWEVER... DUE TO MORE SNFL ACCUMULATION ACROSS THE N HLF OF THE
FA...THE CONCERN IS MORE TOWARD BLSN...SO WE INCLUDED STRONG WINDS
WITHIN THE WSW WNTR WX ADV STATEMENT. ACROSS THE SRN HLF OF THE FA
WHERE THERE IS LESS ACCUMULATION...WE MENTION PATCHY BLSN WITHIN
THE NPW WIND ADV STATEMENT. BOTH HDLNS ARE IN EFFECT UNTIL ERLY
EVE... AFTER WHICH...WIND GUST POTENTIAL WILL SLOWLY DIMINISH
OVRNGT.
TEMPS WILL FALL SHARPLY ACROSS THE FA ERLY THIS MORN FOLLOWING THE
ARCTIC FRONT...AND WILL NOT LIKELY MAKE MUCH GAIN THRU THE REMAINDER
OF THE MORNG INTO ERLY AFTN...THEN FALL BY LATE AFTN...AS THE
STRENGTHENING LATE MAR SUN ANGLE AND INCREASING DAYLENGTH IS ABOUT
EVENLY MATCHED BY STRONG LLVL COLD ADVCN. MEANWHILE...THE BACK
EDGE OF STEADY SN WILL NOT MAKE MUCH HEADWAY OUT OF XTRM NE PTNS
OF THE FA DUE TO THE DEEPENING MARITIMES LOW...SO SCT SN SHWRS
COULD AFFECT THE FAR N AND NE OF THE FA THRU THE REMAINDER OF THE
DAY.
INTERESTINGLY...TEMPS WILL CONT TO FALL THRU THE EVE...THEN LVL
OFF LATE TNGT AND EVEN INCREASE BY DAYBREAK SPCLY ACROSS THE N HLF
OF FA AS A WARM OCCLUSION FROM THE DEEPENING LOW WORKS IT WAY ALL
THE WAY ARND THE N SIDE OF THE SYSTEM AND THEN BACK SW TOWARD THE
GASPE PENINSULA. THIS WILL KEEP SCT SN SHWRS ACROSS THE NRN TWO
THIRDS OF THE FA AND EVEN INTERMITTENT LGT SNFL GOING ACROSS THE
FAR N AND NE WHILE CLDNSS SLIPS BACK TOWARD E CNTRL PTNS OF THE
FA LATE TNGT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
FOR MONDAY...WINDS AND CONTINUED COLD WILL BE THE PRIMARY
FEATURES. HIGHS WILL MODERATE INTO THE 20S...BUT REMAIN FAR BELOW
NORMAL. WINDS WILL GUST TOWARDS 35 MPH BY LATE MORNING IN NORTHERN
ZONES. CLOUDY SKIES WILL PREVAIL EXCEPT IN THE DOWNSLOPE REGIONS
AROUND BANGOR AND MUCH OF DOWN EAST. THE WINDS FINALLY DECREASE
MONDAY NIGHT WITH RAPIDLY RISING SURFACE PRESSURE. LOWS WILL DROP
INTO THE SINGLE DIGITS TO LOW TEENS. SUBZERO READINGS ARE POSSIBLE
IN THE ALLAGASH WHERE WINDS WILL BE LIGHTEST. SUNSHINE WILL
PROMOTE A NICE RECOVERY ON TUESDAY AND BRING HIGHS BACK ABOVE
FREEZING FOR MOST LOCATIONS. MID TO UPPER 30S ARE PROBABLE FOR
BANGOR AND DOWN EAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A SHALLOW RADIATION INVERSION WILL DEVELOP ON TUESDAY NIGHT WITH
WIDE VARIATIONS IN NIGHTTIME TEMPS. COLDER NORTHERN VALLEY COULD
SEE SUBZERO READINGS WHILE HIGHER TERRAIN WILL STAY IN THE TEENS.
THE SHALLOW INVERSION WILL BE QUICKLY ERASED WEDNESDAY MORNING AND
TEMPERATURES WILL PUSH TOWARDS THE UPPER 30S AND LOWER 40S UNDER
SUNNY SKIES. CLOUDS WILL INCREASE LATE AHEAD OF A LOW PROGGED TO
TRACK ACROSS QUEBEC ON THURSDAY. THIS SYSTEM WILL BRING LIGHT
AMOUNTS OF WARM ADVECTION SNOW WEDNESDAY NIGHT. THIS SNOW WILL
QUICKLY MELT WITH HIGHS AGAIN REACHING THE MID 40S ON THURSDAY.
THERE IS A LOT OF UNCERTAINTY AS TO HOW THINGS PLAY OUT AFTER THE
WARM OCCLUSION ON WEDNESDAY NIGHT. A FRONTAL BOUNDARY IS EXPECTED
TO BE STATIONARY JUST SOUTH OF THE FORECAST AREA THURSDAY. A
COUPLE OF SOUTHERN STREAM SHORTWAVES ARE LIKELY TO MOVE NORTHEAST
ALONG THE FRONTAL BOUNDARY. THESE SHORTWAVES HAVE THE POTENTIAL
TO BRING QUITE A BIT OF RAIN. THE QUESTION IS EXACTLY WHERE THE
BOUNDARY WILL SET UP AND WHICH SHORTWAVE WILL BE DOMINANT. FOR
NOW...HAVE FOLLOWED AN ENSEMBLE APPROACH BEST MIRRORED BY THE
OPERATIONAL ECMWF WHERE THE FIRST WAVE AFFECTS THE SOUTHERN THIRD
OF THE FORECAST AREA THURSDAY AND THURSDAY EVENING WITH THE THREAT
OF A HALF INCH OF RAIN AND WIDESPREAD FOG. BANGOR AND THE DOWN
EAST REGION MAY STAY ABOVE THE FREEZING MARK FROM MIDDAY WEDNESDAY
UNTIL FRIDAY NIGHT. THUS...THERE IS A THREAT THAT ICE WILL START
MOVING AND JAMMING IN THE SOUTHERN PORTION OF THE FORECAST AREA BY
THURSDAY NIGHT OR FRIDAY. IF THE SOUTHERN STREAM SHORTWAVE IS MORE
POTENT THAN CURRENTLY EXPECTED...THERE COULD BE MORE WIDESPREAD
FLOOD CONCERNS. A SECOND SHORTWAVE IS A THREAT TO AFFECT THE AREA
LATER FRIDAY AND FRIDAY NIGHT...BUT WILL FORECAST IT TO MOVE SOUTH
OF THE AREA FOR NOW. INSTEAD...WILL BRING A COLD FRONT ACROSS THE
AREA ON FRIDAY THAT WILL BRING THE SUBFREEZING TEMPERATURES BACK
TO BANGOR AND DOWN EAST ON FRIDAY NIGHT.
THAT SAID...THERE IS LOW CONFIDENCE ON THE EVOLUTION AND MOVEMENT
OF AN UPPER TROUGH MOVING OUT OF THE MIDWEST THURSDAY THROUGH
FRIDAY NIGHT. THERE IS RISK OF SIGNIFICANT RAINFALL...SNOWMELT AND
ICE JAMS DURING THIS PERIOD. THE BIGGEST RISK WILL BE IN THE
SOUTHERN HALF OF THE FORECAST AREA WHERE TEMPERATURES WILL BE
HIGHER. THE CHANCES OF HEAVIER RAINFALL WILL BE GREATER THERE AS
WELL.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: IFR TO MVFR CONDITIONS XPCTD TDY ACROSS NRN TAF SITES
IN FALLING SN TRANSITIONING TO BLSN AS FALLING SN IS REPLACED BY
STRONG NW WINDS. DOWNEAST SITES WILL BE MSLY VFR TDY...WITH BRIEF
MVFR IN BLSN POSSIBLE. NRN TAF SITES WILL THEN IMPROVE TO LOW VFR
TO HI MVFR SC CLGS TNGT AS WIND GUSTS LOWER SOMEWHAT REDUCING BLSN
WHILE DOWNEAST SITES BECOME STEADY VFR.
SHORT TERM: MVFR CIGS FROM HUL NORTHWARD ON MONDAY. OTHERWISE VFR
FOR ALL TERMINALS UNTIL WEDNESDAY NIGHT. EXPECT PREDOMINANT IFR
WEDNESDAY NIGHT INTO THURSDAY WITH THE CHANCE OF FOG ON THURSDAY.
&&
.MARINE...
NEAR TERM: WILL CONT WITH THE CURRENT GLW AND FZGSPY ADV AS
INITIALLY WINDS INCREASE ERLY THIS MORN BEHIND THE ARCTIC FRONT
WITH THE FZGSPY ADV DELAYED A FEW HRS TO ALLOW COLDER AIR TO WORK
OVR THE WATERS. BOTH HDLNS THEN REMAIN IN EFFECT THRU THE
REMAINDER OF THE NEAR TERM THRU ALL OF SUN NGT.
SHORT TERM: THE GALE AND FREEZING SPRAY WILL END LATER MONDAY
MORNING AND GIVE WAY TO AN SCA THAT WILL CONTINUE INTO MONDAY
EVENING. THE NEXT CONCERN WILL BE A STRONG SCA ON WEDNESDAY NIGHT
INTO THURSDAY. SEAS COULD REACH 15 FEET IN A SOUTH SWELL. WINDS
WILL BE THE LESSER CONCERN WITH THIS EVENT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
MEZ001>006-010.
WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MEZ011-015>017-
029>032.
MARINE...FREEZING SPRAY ADVISORY UNTIL 11 AM EDT MONDAY FOR ANZ050>052.
GALE WARNING UNTIL 11 AM EDT MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...DUDA/VJN
SHORT TERM...MCW
LONG TERM...MCW/BERDES
AVIATION...DUDA/VJN/MCW
MARINE...DUDA/VJN/MCW
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1004 AM EDT SUN MAR 22 2015
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO INTENSIFY ACROSS THE MARITIMES
TODAY AND TONIGHT. CANADIAN HIGH PRESSURE WILL BUILD EAST TOWARD
THE REGION LATER MONDAY THROUGH TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE: LOW PRESSURE NEAR THE EASTERN TIP OF NOVA SCOTIA
WILL CONTINUE TO INTENSIFY AS IT ROTATES NORTHWEST ACROSS THE
CANADIAN MARITIMES TODAY. A STRONG PRESSURE GRADIENT ACROSS THE
AREA WILL RESULT IN GUSTY WEST WINDS TODAY ALONG WITH SOME LIGHT
SNOW ACROSS NORTHERN AREAS. WINDS COULD GUST AS HIGH AS 45 TO 50 MPH
AT TIMES ESPECIALLY ACROSS THE HIGHER TERRAIN. ANY ADDITIONAL SNOW
ACCUMULATION WILL BE AN INCH OR LESS. THE BIGGER CONCERN WILL BE
AREAS OF BLOWING SNOW MAINLY ACROSS NORTHERN AREAS THAT WILL
ABRUPTLY REDUCE VISIBILITY AT TIMES ESPECIALLY ON NORTH-SOUTH
ROADS. FOR THIS REASON, WE WILL KEEP THE WINTER WEATHER ADVISORY
GOING TODAY. WILL ALSO KEEP THE WIND ADVISORY GOING ACROSS CENTRAL
AND DOWN EAST AREAS FOR TODAY. ALL-IN-ALL, THE CURRENT FORECAST
HAS THINGS COVERED QUITE NICELY AND NO SIGNIFICANT ADJUSTMENTS
WERE MADE TO THE FORECAST ON THIS UPDATE.
PREVIOUS DISCUSSION
OTHERWISE...LATEST HRRR SIM RADAR IMAGERY SHOWS MUCH OF THE
REMAINING PTN OF STEADY SN RETREATING INTO NRN NB BY LATE MORN.
HELD OFF FOR NOW TO ADJUSTING POPS DOWNWARD OVR THE FAR N...SINCE
LATEST 06Z SYNOPTIC MODELS STILL INDICATE A FEW HUNDREDTHS OF AN
IN OF QPF OVR THIS PTN OF THE FA BETWEEN 12 AND 18Z (8AM-2PM)
TODAY.
ORGNL DISC: LATEST RADAR IMAGERY SHOWS THE BACK EDGE OF STEADY
SNFL NOW SLIDING E OUT OF DOWNEAST AND CNTRL PTNS OF THE FA INTO
NB PROV... BUT STILL HOLDING ACROSS NRN AND ERN AROOSTOOK
COUNTY...AT LEAST FOR THE NEXT FEW HRS. AFTWRDS...WNW WINDS WILL
DRAMATICALLY INCREASE ACROSS ALL OF THE REGION FOLLOWING THE
PASSAGE OF AN ARCTIC FRONT WITHIN THE NEXT 1 TO 3 HRS. WIND GUSTS
WILL BE REACHING MID TO HIGH END WIND ADV CRITERIA BY AFTN.
HOWEVER... DUE TO MORE SNFL ACCUMULATION ACROSS THE N HLF OF THE
FA...THE CONCERN IS MORE TOWARD BLSN...SO WE INCLUDED STRONG WINDS
WITHIN THE WSW WNTR WX ADV STATEMENT. ACROSS THE SRN HLF OF THE FA
WHERE THERE IS LESS ACCUMULATION...WE MENTION PATCHY BLSN WITHIN
THE NPW WIND ADV STATEMENT. BOTH HDLNS ARE IN EFFECT UNTIL ERLY
EVE... AFTER WHICH...WIND GUST POTENTIAL WILL SLOWLY DIMINISH
OVRNGT.
TEMPS WILL FALL SHARPLY ACROSS THE FA ERLY THIS MORN FOLLOWING THE
ARCTIC FRONT...AND WILL NOT LIKELY MAKE MUCH GAIN THRU THE REMAINDER
OF THE MORNG INTO ERLY AFTN...THEN FALL BY LATE AFTN...AS THE
STRENGTHENING LATE MAR SUN ANGLE AND INCREASING DAYLENGTH IS ABOUT
EVENLY MATCHED BY STRONG LLVL COLD ADVCN. MEANWHILE...THE BACK
EDGE OF STEADY SN WILL NOT MAKE MUCH HEADWAY OUT OF XTRM NE PTNS
OF THE FA DUE TO THE DEEPENING MARITIMES LOW...SO SCT SN SHWRS
COULD AFFECT THE FAR N AND NE OF THE FA THRU THE REMAINDER OF THE
DAY.
INTERESTINGLY...TEMPS WILL CONT TO FALL THRU THE EVE...THEN LVL
OFF LATE TNGT AND EVEN INCREASE BY DAYBREAK SPCLY ACROSS THE N HLF
OF FA AS A WARM OCCLUSION FROM THE DEEPENING LOW WORKS IT WAY ALL
THE WAY ARND THE N SIDE OF THE SYSTEM AND THEN BACK SW TOWARD THE
GASPE PENINSULA. THIS WILL KEEP SCT SN SHWRS ACROSS THE NRN TWO
THIRDS OF THE FA AND EVEN INTERMITTENT LGT SNFL GOING ACROSS THE
FAR N AND NE WHILE CLDNSS SLIPS BACK TOWARD E CNTRL PTNS OF THE
FA LATE TNGT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
FOR MONDAY...WINDS AND CONTINUED COLD WILL BE THE PRIMARY
FEATURES. HIGHS WILL MODERATE INTO THE 20S...BUT REMAIN FAR BELOW
NORMAL. WINDS WILL GUST TOWARDS 35 MPH BY LATE MORNING IN NORTHERN
ZONES. CLOUDY SKIES WILL PREVAIL EXCEPT IN THE DOWNSLOPE REGIONS
AROUND BANGOR AND MUCH OF DOWN EAST. THE WINDS FINALLY DECREASE
MONDAY NIGHT WITH RAPIDLY RISING SURFACE PRESSURE. LOWS WILL DROP
INTO THE SINGLE DIGITS TO LOW TEENS. SUBZERO READINGS ARE POSSIBLE
IN THE ALLAGASH WHERE WINDS WILL BE LIGHTEST. SUNSHINE WILL
PROMOTE A NICE RECOVERY ON TUESDAY AND BRING HIGHS BACK ABOVE
FREEZING FOR MOST LOCATIONS. MID TO UPPER 30S ARE PROBABLE FOR
BANGOR AND DOWN EAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A SHALLOW RADIATION INVERSION WILL DEVELOP ON TUESDAY NIGHT WITH
WIDE VARIATIONS IN NIGHTTIME TEMPS. COLDER NORTHERN VALLEY COULD
SEE SUBZERO READINGS WHILE HIGHER TERRAIN WILL STAY IN THE TEENS.
THE SHALLOW INVERSION WILL BE QUICKLY ERASED WEDNESDAY MORNING AND
TEMPERATURES WILL PUSH TOWARDS THE UPPER 30S AND LOWER 40S UNDER
SUNNY SKIES. CLOUDS WILL INCREASE LATE AHEAD OF A LOW PROGGED TO
TRACK ACROSS QUEBEC ON THURSDAY. THIS SYSTEM WILL BRING LIGHT
AMOUNTS OF WARM ADVECTION SNOW WEDNESDAY NIGHT. THIS SNOW WILL
QUICKLY MELT WITH HIGHS AGAIN REACHING THE MID 40S ON THURSDAY.
THERE IS A LOT OF UNCERTAINTY AS TO HOW THINGS PLAY OUT AFTER THE
WARM OCCLUSION ON WEDNESDAY NIGHT. A FRONTAL BOUNDARY IS EXPECTED
TO BE STATIONARY JUST SOUTH OF THE FORECAST AREA THURSDAY. A
COUPLE OF SOUTHERN STREAM SHORTWAVES ARE LIKELY TO MOVE NORTHEAST
ALONG THE FRONTAL BOUNDARY. THESE SHORTWAVES HAVE THE POTENTIAL
TO BRING QUITE A BIT OF RAIN. THE QUESTION IS EXACTLY WHERE THE
BOUNDARY WILL SET UP AND WHICH SHORTWAVE WILL BE DOMINANT. FOR
NOW...HAVE FOLLOWED AN ENSEMBLE APPROACH BEST MIRRORED BY THE
OPERATIONAL ECMWF WHERE THE FIRST WAVE AFFECTS THE SOUTHERN THIRD
OF THE FORECAST AREA THURSDAY AND THURSDAY EVENING WITH THE THREAT
OF A HALF INCH OF RAIN AND WIDESPREAD FOG. BANGOR AND THE DOWN
EAST REGION MAY STAY ABOVE THE FREEZING MARK FROM MIDDAY WEDNESDAY
UNTIL FRIDAY NIGHT. THUS...THERE IS A THREAT THAT ICE WILL START
MOVING AND JAMMING IN THE SOUTHERN PORTION OF THE FORECAST AREA BY
THURSDAY NIGHT OR FRIDAY. IF THE SOUTHERN STREAM SHORTWAVE IS MORE
POTENT THAN CURRENTLY EXPECTED...THERE COULD BE MORE WIDESPREAD
FLOOD CONCERNS. A SECOND SHORTWAVE IS A THREAT TO AFFECT THE AREA
LATER FRIDAY AND FRIDAY NIGHT...BUT WILL FORECAST IT TO MOVE SOUTH
OF THE AREA FOR NOW. INSTEAD...WILL BRING A COLD FRONT ACROSS THE
AREA ON FRIDAY THAT WILL BRING THE SUBFREEZING TEMPERATURES BACK
TO BANGOR AND DOWN EAST ON FRIDAY NIGHT.
THAT SAID...THERE IS LOW CONFIDENCE ON THE EVOLUTION AND MOVEMENT
OF AN UPPER TROUGH MOVING OUT OF THE MIDWEST THURSDAY THROUGH
FRIDAY NIGHT. THERE IS RISK OF SIGNIFICANT RAINFALL...SNOWMELT AND
ICE JAMS DURING THIS PERIOD. THE BIGGEST RISK WILL BE IN THE
SOUTHERN HALF OF THE FORECAST AREA WHERE TEMPERATURES WILL BE
HIGHER. THE CHANCES OF HEAVIER RAINFALL WILL BE GREATER THERE AS
WELL.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: IFR TO MVFR CONDITIONS XPCTD TDY ACROSS NRN TAF SITES
IN FALLING SN TRANSITIONING TO BLSN AS FALLING SN IS REPLACED BY
STRONG NW WINDS. DOWNEAST SITES WILL BE MSLY VFR TDY...WITH BRIEF
MVFR IN BLSN POSSIBLE. NRN TAF SITES WILL THEN IMPROVE TO LOW VFR
TO HI MVFR SC CLGS TNGT AS WIND GUSTS LOWER SOMEWHAT REDUCING BLSN
WHILE DOWNEAST SITES BECOME STEADY VFR.
SHORT TERM: MVFR CIGS FROM HUL NORTHWARD ON MONDAY. OTHERWISE VFR
FOR ALL TERMINALS UNTIL WEDNESDAY NIGHT. EXPECT PREDOMINANT IFR
WEDNESDAY NIGHT INTO THURSDAY WITH THE CHANCE OF FOG ON THURSDAY.
&&
.MARINE...
NEAR TERM: WILL CONT WITH THE CURRENT GLW AND FZGSPY ADV AS
INITIALLY WINDS INCREASE ERLY THIS MORN BEHIND THE ARCTIC FRONT
WITH THE FZGSPY ADV DELAYED A FEW HRS TO ALLOW COLDER AIR TO WORK
OVR THE WATERS. BOTH HDLNS THEN REMAIN IN EFFECT THRU THE
REMAINDER OF THE NEAR TERM THRU ALL OF SUN NGT.
SHORT TERM: THE GALE AND FREEZING SPRAY WILL END LATER MONDAY
MORNING AND GIVE WAY TO AN SCA THAT WILL CONTINUE INTO MONDAY
EVENING. THE NEXT CONCERN WILL BE A STRONG SCA ON WEDNESDAY NIGHT
INTO THURSDAY. SEAS COULD REACH 15 FEET IN A SOUTH SWELL. WINDS
WILL BE THE LESSER CONCERN WITH THIS EVENT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
MEZ001>006-010.
WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MEZ011-015>017-
029>032.
MARINE...FREEZING SPRAY ADVISORY UNTIL 11 AM EDT MONDAY FOR ANZ050>052.
GALE WARNING UNTIL 11 AM EDT MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...DUDA/VJN
SHORT TERM...MCW
LONG TERM...MCW/BERDES
AVIATION...DUDA/VJN/MCW
MARINE...DUDA/VJN/MCW
AREA FORECAST DISCUSSION
NWS CARIBOU ME
627 AM EDT SUN MAR 22 2015
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO INTENSIFY ACROSS THE MARITIMES
TODAY AND TONIGHT. CANADIAN HIGH PRESSURE WILL BUILD EAST TOWARD
THE REGION LATER MONDAY THROUGH TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
615 AM UPDATE: NO SIG CHGS THIS UPDATE. OF COURSE...TEMPS HAVE
FALLEN FASTER THAN WHAT WAS EARLIER FCST BY INTERPOLATION. SO WE
LOADED BOTH 5 AND 6 AM OBSVD TEMPS AND MADE CHGS TO THE PRIOR
NGT`S FCST LOW TEMPS...WHICH MSLY FEATURED COLDER LOWS OVR THE
FAR W. WE DID NOT ADJUST HI TEMPS THIS AFTN ATTM. SINCE TEMPS ERLY
THIS MORN DID GET COLDER THEN PREV OVRNGT LOWS OVR THE W...IT IS
CONCEIVABLE THAT THERE COULD BE SOME RECOVERY OF TEMPS THERE LATER
THIS MORN INTO ERLY AFTN.
OTHERWISE...LATEST HRRR SIM RADAR IMAGERY SHOWS MUCH OF THE
REMAINING PTN OF STEADY SN RETREATING INTO NRN NB BY LATE MORN.
HELD OFF FOR NOW TO ADJUSTING POPS DOWNWARD OVR THE FAR N...SINCE
LATEST 06Z SYNOPTIC MODELS STILL INDICATE A FEW HUNDREDTHS OF AN
IN OF QPF OVR THIS PTN OF THE FA BETWEEN 12 AND 18Z (8AM-2PM)
TODAY.
ORGNL DISC: LATEST RADAR IMAGERY SHOWS THE BACK EDGE OF STEADY
SNFL NOW SLIDING E OUT OF DOWNEAST AND CNTRL PTNS OF THE FA INTO
NB PROV... BUT STILL HOLDING ACROSS NRN AND ERN AROOSTOOK
COUNTY...AT LEAST FOR THE NEXT FEW HRS. AFTWRDS...WNW WINDS WILL
DRAMATICALLY INCREASE ACROSS ALL OF THE REGION FOLLOWING THE
PASSAGE OF AN ARCTIC FRONT WITHIN THE NEXT 1 TO 3 HRS. WIND GUSTS
WILL BE REACHING MID TO HIGH END WIND ADV CRITERIA BY AFTN.
HOWEVER... DUE TO MORE SNFL ACCUMULATION ACROSS THE N HLF OF THE
FA...THE CONCERN IS MORE TOWARD BLSN...SO WE INCLUDED STRONG WINDS
WITHIN THE WSW WNTR WX ADV STATEMENT. ACROSS THE SRN HLF OF THE FA
WHERE THERE IS LESS ACCUMULATION...WE MENTION PATCHY BLSN WITHIN
THE NPW WIND ADV STATEMENT. BOTH HDLNS ARE IN EFFECT UNTIL ERLY
EVE... AFTER WHICH...WIND GUST POTENTIAL WILL SLOWLY DIMINISH
OVRNGT.
TEMPS WILL FALL SHARPLY ACROSS THE FA ERLY THIS MORN FOLLOWING THE
ARCTIC FRONT...AND WILL NOT LIKELY MAKE MUCH GAIN THRU THE REMAINDER
OF THE MORNG INTO ERLY AFTN...THEN FALL BY LATE AFTN...AS THE
STRENGTHENING LATE MAR SUN ANGLE AND INCREASING DAYLENGTH IS ABOUT
EVENLY MATCHED BY STRONG LLVL COLD ADVCN. MEANWHILE...THE BACK
EDGE OF STEADY SN WILL NOT MAKE MUCH HEADWAY OUT OF XTRM NE PTNS
OF THE FA DUE TO THE DEEPENING MARITIMES LOW...SO SCT SN SHWRS
COULD AFFECT THE FAR N AND NE OF THE FA THRU THE REMAINDER OF THE
DAY.
INTERESTINGLY...TEMPS WILL CONT TO FALL THRU THE EVE...THEN LVL
OFF LATE TNGT AND EVEN INCREASE BY DAYBREAK SPCLY ACROSS THE N HLF
OF FA AS A WARM OCCLUSION FROM THE DEEPENING LOW WORKS IT WAY ALL
THE WAY ARND THE N SIDE OF THE SYSTEM AND THEN BACK SW TOWARD THE
GASPE PENINSULA. THIS WILL KEEP SCT SN SHWRS ACROSS THE NRN TWO
THIRDS OF THE FA AND EVEN INTERMITTENT LGT SNFL GOING ACROSS THE
FAR N AND NE WHILE CLDNSS SLIPS BACK TOWARD E CNTRL PTNS OF THE
FA LATE TNGT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
FOR MONDAY...WINDS AND CONTINUED COLD WILL BE THE PRIMARY
FEATURES. HIGHS WILL MODERATE INTO THE 20S...BUT REMAIN FAR BELOW
NORMAL. WINDS WILL GUST TOWARDS 35 MPH BY LATE MORNING IN NORTHERN
ZONES. CLOUDY SKIES WILL PREVAIL EXCEPT IN THE DOWNSLOPE REGIONS
AROUND BANGOR AND MUCH OF DOWN EAST. THE WINDS FINALLY DECREASE
MONDAY NIGHT WITH RAPIDLY RISING SURFACE PRESSURE. LOWS WILL DROP
INTO THE SINGLE DIGITS TO LOW TEENS. SUBZERO READINGS ARE POSSIBLE
IN THE ALLAGASH WHERE WINDS WILL BE LIGHTEST. SUNSHINE WILL
PROMOTE A NICE RECOVERY ON TUESDAY AND BRING HIGHS BACK ABOVE
FREEZING FOR MOST LOCATIONS. MID TO UPPER 30S ARE PROBABLE FOR
BANGOR AND DOWN EAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A SHALLOW RADIATION INVERSION WILL DEVELOP ON TUESDAY NIGHT WITH
WIDE VARIATIONS IN NIGHTTIME TEMPS. COLDER NORTHERN VALLEY COULD
SEE SUBZERO READINGS WHILE HIGHER TERRAIN WILL STAY IN THE TEENS.
THE SHALLOW INVERSION WILL BE QUICKLY ERASED WEDNESDAY MORNING AND
TEMPERATURES WILL PUSH TOWARDS THE UPPER 30S AND LOWER 40S UNDER
SUNNY SKIES. CLOUDS WILL INCREASE LATE AHEAD OF A LOW PROGGED TO
TRACK ACROSS QUEBEC ON THURSDAY. THIS SYSTEM WILL BRING LIGHT
AMOUNTS OF WARM ADVECTION SNOW WEDNESDAY NIGHT. THIS SNOW WILL
QUICKLY MELT WITH HIGHS AGAIN REACHING THE MID 40S ON THURSDAY.
THERE IS A LOT OF UNCERTAINTY AS TO HOW THINGS PLAY OUT AFTER THE
WARM OCCLUSION ON WEDNESDAY NIGHT. A FRONTAL BOUNDARY IS EXPECTED
TO BE STATIONARY JUST SOUTH OF THE FORECAST AREA THURSDAY. A
COUPLE OF SOUTHERN STREAM SHORTWAVES ARE LIKELY TO MOVE NORTHEAST
ALONG THE FRONTAL BOUNDARY. THESE SHORTWAVES HAVE THE POTENTIAL
TO BRING QUITE A BIT OF RAIN. THE QUESTION IS EXACTLY WHERE THE
BOUNDARY WILL SET UP AND WHICH SHORTWAVE WILL BE DOMINANT. FOR
NOW...HAVE FOLLOWED AN ENSEMBLE APPROACH BEST MIRRORED BY THE
OPERATIONAL ECMWF WHERE THE FIRST WAVE AFFECTS THE SOUTHERN THIRD
OF THE FORECAST AREA THURSDAY AND THURSDAY EVENING WITH THE THREAT
OF A HALF INCH OF RAIN AND WIDESPREAD FOG. BANGOR AND THE DOWN
EAST REGION MAY STAY ABOVE THE FREEZING MARK FROM MIDDAY WEDNESDAY
UNTIL FRIDAY NIGHT. THUS...THERE IS A THREAT THAT ICE WILL START
MOVING AND JAMMING IN THE SOUTHERN PORTION OF THE FORECAST AREA BY
THURSDAY NIGHT OR FRIDAY. IF THE SOUTHERN STREAM SHORTWAVE IS MORE
POTENT THAN CURRENTLY EXPECTED...THERE COULD BE MORE WIDESPREAD
FLOOD CONCERNS. A SECOND SHORTWAVE IS A THREAT TO AFFECT THE AREA
LATER FRIDAY AND FRIDAY NIGHT...BUT WILL FORECAST IT TO MOVE SOUTH
OF THE AREA FOR NOW. INSTEAD...WILL BRING A COLD FRONT ACROSS THE
AREA ON FRIDAY THAT WILL BRING THE SUBFREEZING TEMPERATURES BACK
TO BANGOR AND DOWN EAST ON FRIDAY NIGHT.
THAT SAID...THERE IS LOW CONFIDENCE ON THE EVOLUTION AND MOVEMENT
OF AN UPPER TROUGH MOVING OUT OF THE MIDWEST THURSDAY THROUGH
FRIDAY NIGHT. THERE IS RISK OF SIGNIFICANT RAINFALL...SNOWMELT AND
ICE JAMS DURING THIS PERIOD. THE BIGGEST RISK WILL BE IN THE
SOUTHERN HALF OF THE FORECAST AREA WHERE TEMPERATURES WILL BE
HIGHER. THE CHANCES OF HEAVIER RAINFALL WILL BE GREATER THERE AS
WELL.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: IFR TO MVFR CONDITIONS XPCTD TDY ACROSS NRN TAF SITES
IN FALLING SN TRANSITIONING TO BLSN AS FALLING SN IS REPLACED BY
STRONG NW WINDS. DOWNEAST SITES WILL BE MSLY VFR TDY...WITH BRIEF
MVFR IN BLSN POSSIBLE. NRN TAF SITES WILL THEN IMPROVE TO LOW VFR
TO HI MVFR SC CLGS TNGT AS WIND GUSTS LOWER SOMEWHAT REDUCING BLSN
WHILE DOWNEAST SITES BECOME STEADY VFR.
SHORT TERM: MVFR CIGS FROM HUL NORTHWARD ON MONDAY. OTHERWISE VFR
FOR ALL TERMINALS UNTIL WEDNESDAY NIGHT. EXPECT PREDOMINANT IFR
WEDNESDAY NIGHT INTO THURSDAY WITH THE CHANCE OF FOG ON THURSDAY.
&&
.MARINE...
NEAR TERM: WILL CONT WITH THE CURRENT GLW AND FZGSPY ADV AS
INITIALLY WINDS INCREASE ERLY THIS MORN BEHIND THE ARCTIC FRONT
WITH THE FZGSPY ADV DELAYED A FEW HRS TO ALLOW COLDER AIR TO WORK
OVR THE WATERS. BOTH HDLNS THEN REMAIN IN EFFECT THRU THE
REMAINDER OF THE NEAR TERM THRU ALL OF SUN NGT.
SHORT TERM: THE GALE AND FREEZING SPRAY WILL END LATER MONDAY
MORNING AND GIVE WAY TO AN SCA THAT WILL CONTINUE INTO MONDAY
EVENING. THE NEXT CONCERN WILL BE A STRONG SCA ON WEDNESDAY NIGHT
INTO THURSDAY. SEAS COULD REACH 15 FEET IN A SOUTH SWELL. WINDS
WILL BE THE LESSER CONCERN WITH THIS EVENT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
MEZ001>006-010.
WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MEZ011-015>017-
029>032.
MARINE...FREEZING SPRAY ADVISORY FROM 10 AM THIS MORNING TO 11 AM EDT
MONDAY FOR ANZ050>052.
GALE WARNING UNTIL 11 AM EDT MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...MCW
LONG TERM...MCW/BERDES
AVIATION...VJN/MCW
MARINE...VJN/MCW
AREA FORECAST DISCUSSION...UPDATED
NWS BALTIMORE MD/WASHINGTON DC
924 PM EDT MON MAR 23 2015
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL PASS THROUGH THE AREA LATE TONIGHT
AND HIGH PRESSURE WILL RETURN FOR TUESDAY. THE HIGH WILL MOVE OFF
THE COAST WEDNESDAY AND A COLD FRONT IS EXPECTED TO PASS THROUGH
LATE THURSDAY INTO THURSDAY NIGHT. CANADIAN HIGH PRESSURE WILL
RETURN FOR FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
FAST-APPROACHING IS AN UPPER LEVEL DISTURBANCE...LOCALIZED TO A
RELATIVELY SMALL ZONE OF PRECIP NOW SPREADING FROM ERN OH INTO
WRN PA/WV. A DECENT AMOUNT OF LOCALIZED QPF AND FORCING FOR SOME
MODERATE SNOW SHOWERS ACROSS PORTIONS OF THE UPPER MIDWEST EARLIER
THIS AFTN/EVE. SOME DIVERGENCE HOWEVER IN VARIOUS GUIDANCE MEMBERS
W/ HOW THIS SYSTEM WILL HOLD TOGETHER ONCE IT REACHES THE CNTRL
APLCNS IN THE NEXT FEW HRS. 18Z RUNS OF THE GFS/NAM ARE QPF LIGHT
AND FAIRLY DISJOINTED IN TERMS OF HOW THEY SPREAD PRECIP ACROSS
THE REGION...WHILE THE 12Z EURO HOLDS W/ THE VERY LIGHT QPF PLACED
MAINLY OVER THE WRN HALF OF THE CWA.
REGARDLESS OF EXPECTED MODEL QPF...PLENTY OF LOW LEVEL DRY AIR
WILL NEED TO BE OVERCOME IN ORDER TO HAVE SNOW REACH THE SFC -
ONCE LOW LEVEL TEMPS SUPPORT SNOW. THE LOWEST KM ABOVE THE SFC
STILL ABOVE FREEZING WHICH SHOULD ONLY TAKE A MORE HRS TO DROP
BACK INTO THE 30S. THE LOWEST 2.5 KM HOWEVER SHOWS THAT THE TEMP
AND DEWPOINT ARE VERY FAR APART FROM SATURATION...SO DESPITE THE
FAST-APPROACHING RADAR RETURNS - MODERATE TO HEAVY PRECIP WILL BE
NEEDED TO REDUCE THE INCREDIBLE DRY AIR IN THIS LAYER BEFORE WE
SEE SNOW FALLING OR EVEN ACCUMULATING.
HEADING INTO THE OVERNIGHT HRS...ONCE THE LOW LEVEL HAVE NEARED
SATURATION...SOME OF THE HIGHER TERRAIN LOCALES WILL SEE LIGHT
SNOW AND HEAVIER BATCHES OVER THE POTOMAC HIGHLANDS AS WELL. THE
MASON-DIXON LINE WILL ALSO INITIALLY BE A FOCUS FOR SOME POTENTIAL
LIGHT SNOW AS A PSEUDO-WARM FRONTAL BOUNDARY SWINGS ACROSS THIS
AREA W/ WEAK FORCING. SLIGHTLY REDUCED THE SNOW ACCUMNS FOR NRN MD
AND INCREASED THEM FOR THE BLUE RIDGE AND SOME OF THE POTOMAC
HIGHLANDS REGION OF THE WV PANHANDLE/WRN MD. HI-RES HOURLY MODELS
ARE WELL INTO VIEW NOW FOR VARIOUS WRF VERSIONS AND THE HRRR WHICH
SHOW MUCH OF THE INCOMING PRECIP DISSIPATING OVER THE CNTRL APLCNS
AND ONLY A FRACTION MAKING IT FURTHER EAST.
KEPT A LOW-MED CHANCE OF SNOW OVERNIGHT AND INTO EARLY TUE...W/
BRIEF LIKELIES FOR THE NRN/WRN HALVES OF THE CWA FOR A LIGHT
DUSTING/COATING OF SNOW TOWARD THE PREDAWN HRS OR EARLIER. MUCH OF
THIS ACTIVITY SHOULD DISSIPATE AND MOVE EAST OF THE AREA POST DAWN
TUE...W/ A LINGERING LOW CLOUD DECK HANGING AROUND THRU THE
REMAINDER OF THE DAY AND A COOL ONSHORE SFC BREEZE. MAX TEMPS
WILL REMAIN WELL BELOW CLIMO...RANGING FROM THE 30S IN THE
MOUNTAINS TO THE MID AND UPPER 40S IN CENTRAL VIRGINIA.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
THE NEXT WEAK UPPER DISTURBANCE WILL CROSS THE REGION LATE TUESDAY
NIGHT INTO WEDNESDAY MORNING. HIGH PRESSURE WILL BE TO THE NORTH
AND PROVIDE JUST ENOUGH COLD AIR TO INTRODUCE THE POTENTIAL FOR
SOME LIGHT IP OR ZR FOR THE FAR N AND W SUBURBS. ELSEWHERE...IT
APPEARS TEMPS WILL BE WARM ENOUGH FOR RAIN.
HIGH PRESSURE WILL EXIT OFF THE MIDDLE ATLANTIC COAST BY WEDNESDAY
AFTERNOON AND WINDS WILL TURN SOUTHERLY. WARMER TEMPERATURES AND
HIGHER MOISTURE WILL STREAM NORTH INTO THE FORECAST AREA DURING THE
AFTERNOON AND INTO THE NIGHT. WARM AIR ADVECTION PATTERN WILL YIELD
A CHANCE FOR RAIN DURING THIS TIME FRAME. TEMPERATURES WEDNESDAY
NIGHT MAY NOT FALL OFF THAT MUCH WITH SOUTHERLY FLOW.
MOSTLY CLOUDY AND WARM CONDITIONS ARE EXPECTED FOR THE FIRST PART OF
THURSDAY. TEMPERATURES ARE EXPECTED TO RIDGE THROUGH THE 60S IN MANY
LOCATIONS...EVEN A FEW 70S OVER CENTRAL VA AND SOUTHERN MD. MOISTURE
AND INSTABILITY WILL BE IN PLACE AHEAD OF A COLD FRONT THAT WILL
SWEEP ACROSS THE REGION THURSDAY NIGHT. SHOWERS AND A FEW TSTMS WILL
BE POSSIBLE. SOME OF THE STORMS COULD CONTAIN GUSTY WINDS. THE SEVERE
THREAT APPEARS MINIMAL AT THIS TIME BUT THE SITUATION WILL NEED TO
BE MONITORED.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A COLD FRONT WILL SWEEP ACROSS THE AREA THURSDAY EVENING INTO THE
NIGHT. RAIN SHOWERS ARE EXPECTED AS THE FRONT APPROACHES...AND
HAVE KEPT A SLGT CHANCE OF THNDRSTMS FOR THE FIRST HALF OF THE
NIGHT. KEPT SLIGHT CHANCE FOR MORE PRECIP POST-FRONTAL. UPPER
THROUGH SWEEPS THROUGH THE AREA FRI NIGHT INTO EARLY SAT...SO
KEEPING SLIGHT CHNC OF POPS FOR THAT. HIGH PRESSURE BUILDS LATE ON
SATURDAY BRINGING COOLER AND DRIER CONDITIONS BEFORE ANOTHER COLD
FRONT APPROACHES SUNDAY NIGHT INTO MONDAY. BELOW NORMAL TEMPS ARE
EXPECTED FOR FRI NIGHT INTO SAT NIGHT.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
AN UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE AREA LATE TONIGHT
INTO TUESDAY MORNING. A PERIOD OF LIGHT SNOW OR FLURRIES IS
POSSIBLE...ESPECIALLY ACROSS THE NORTHERN TERMINALS. SUBVFR CIGS
AND VSBYS ARE EXPECTED IN ANY SNOW THAT DEVELOPS.
VFR TO START TUESDAY NIGHT FOLLOWED BY SUB-VFR CIGS AND VSBYS
ALONG WITH A CHANCE FOR MOSTLY RAIN WEDNESDAY MORNING INTO THE
NIGHT. SOME LIGHT IP OR ZR MAY BE POSSIBLE FOR AREAS TO THE NORTH
AND WEST OF KDCA AND KBWI FOR A SHORT PERIOD WEDNESDAY AM. CIGS
WILL LIKELY STAY BKN-OVC MUCH OF WEDNESDAY INTO THURSDAY. A COLD
FRONT WILL BRING SHOWERS AND A FEW THUNDERSTORMS THURSDAY AFTN AND
EVENING. SOME OF THE STORMS COULD CONTAIN GUSTY WINDS.
THE UPPER-LEVEL DISTURBANCE WILL MOVE AWAY FROM THE AREA LATER
TUESDAY MORNING...BUT A STRATO CU DECK MAY HANG AROUND FOR MUCH OF
THE DAY WITH MVFR CIGS POSSIBLE.
A COLD FRONT WILL MOVE THROUGH THURSDAY EVENING/NIGHT...WITH SHRA
LIKELY AND A PSBL TSTM INTO FRI. S-SW WINDS WITH SOME PSBL GUSTS
15-20KTS TURNING NW THUR NIGHT. VFR LIKELY FRIDAY WITH NW WINDS
FRI. GUSTY CONDITIONS ON SATURDAY.
&&
.MARINE...
SURFACE HIGH PRESSURE WILL EXTEND OVER THE WATERS THROUGH TUESDAY.
WINDS WILL REMAIN BELOW SCA CRITERIA DURING THIS TIME.
SCA CONDITIONS MAY BE POSSIBLE ON THE WATERS WEDNESDAY AND
THURSDAY AHEAD OF A COLD FRONT. SOUTHERLY WINDS WILL SHIFT TO WEST
LATE THURSDAY NIGHT INTO FRIDAY. EXPECT PERIODS OF RAIN...SHOWERS
AND POSSIBLY A FEW THUNDERSTORMS WEDNESDAY INTO THURSDAY. SOME OF
THE STORMS COULD CONTAIN GUSTY WINDS THURSDAY AFTERNOON AND
EVENING.
BETTER CHANCE OF SCA THURSDAY WITH STRONGER S-SW WINDS AHEAD OF A
COLD FRONT. SHOWERS AND A PSBL TSTM THURSDAY EVENING INTO THE
NIGHT. WINDS SHIFT TO THE NW THUR NIGHT BEHIND THE FRONT. POSS SCA
ON SAT WITH INCREASING WINDS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...GMS
PREV DISCUSSION...BJL/KRW/IR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
141 PM EDT SUN MAR 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 502 AM EDT SUN MAR 22 2015
DESPITE 850MB TEMPS AROUND -17C PER LATEST RAP ANALYSIS...THERE ARE
NO LAKE EFFECT CLOUDS DEVELOPING OFF THE OPEN WATER OF NCNTRL LAKE
SUPERIOR. EVEN OFF THE OPEN WATER EXTENDING FROM THE KEWEENAW TO
MUNISING...THERE WAS A LITTLE BURST OF LES EARLIER IN THE NIGHT INTO
ALGER COUNTY...BUT THAT HAS SINCE DISSIPATED. CONVERGENCE HAS
RECENTLY STRENGTHENED OVER THAT OPEN WATER AREA AS A WIND SHIFT TO
THE ENE IS PROGRESSING TOWARD THE MARQUETTE COUNTY SHORELINE WHERE
LAND BREEZE IS EVIDENT. IN JUST IN THE LAST HR...THIS HAS RESULTED
IN NEW LIGHT LES DEVELOPMENT OVER FAR ERN MARQUETTE COUNTY.
OTHERWISE...AS OF 09Z...THAT IS IT FOR LES AND EVEN LAKE EFFECT
CLOUDS OFF LAKE SUPERIOR. UPSTREAM 00Z SOUNDINGS AT KINL/CYPL TELL
THE STORY AS NOT ONLY WAS THE AIR MASS DRY IN THE LOW TO MID
LEVELS...BUT BOTH SOUNDINGS ALSO EXHIBITED THE HOSTILE FOR LES
INVERTED V LOOK.
WOULD EXPECT A CONTINUED UPTICK IN LES OFF SCNTRL LAKE SUPERIOR INTO
FAR ERN MARQUETTE COUNTY AND ALGER COUNTY EARLY THIS MORNING AS WE
APPROACH THE COOLEST PART OF THE DIURNAL CYCLE/MOST FAVORABLE TIME
OF DAY FOR LES AT THIS TIME OF YEAR. THAT SAID...IT WON`T BE MORE
THAN LIGHT SNOW SHOWERS AND FLURRIES WITH ANY ACCUMULATION UNDER 1
INCH. THE DISRUPTIVE EFFECT OF DAYTIME HEATING AT THIS TIME OF YEAR
COMBINED WITH 850MB THERMAL TROF SHIFTING E WILL BRING AN END TO THE
LIGHT LES EARLY THIS AFTN. ACROSS THE REST OF THE FCST AREA...EXPECT
A PARTLY TO MOSTLY SUNNY DAY WITH HIGHS IN THE 20S ACROSS MOST OF
THE N AND E TO THE 30S TOWARD THE MI/WI BORDER.
SHORTWAVE MOVING ACROSS THE DAKOTAS TODAY AND INTO THE WRN GREAT
LAKES TONIGHT WILL WEAKEN AS IT ENCOUNTERS INCREASINGLY CONFLUENT
FLOW. MODELS SHOW THIS WAVE SPREADING PCPN ACROSS MN INTO WI. MODELS
WHICH HAD PREVIOUSLY BROUGHT THE PCPN TO NEAR THE MI/WI BORDER
TONIGHT HAVE TRENDED S WITH THE NRN EDGE OF THE PCPN. GIVEN THE
CONFLUENT FLOW OVER THE UPPER LAKES...ESTABLISHED ARCTIC AIR AND
CONTINUED DRY AIR EMANATING FROM THE SFC HIGH PRES AREA WHICH WILL
BE SLOWLY DRIFTING E OF HERE...A DRY FCST IS THE WAY TO GO TONIGHT.
MIN TEMPS TONIGHT COULD BE QUITE LOW...ESPECIALLY OVER THE ERN FCST
AREA WHERE HIGH/MID CLOUDS WILL BE THINNEST AND WHERE THERE WILL BE
LIGHT ENE WINDS OFF ONTARIO. EXPECT TRADITIONAL COLD SPOTS TO FALL
TO NEAR 0F OR EVEN BLO. DEPENDING ON THICKNESS OF CLOUDS...SINGLE
DIGITS ABOVE ZERO MAY BE COMMON IN THE INTERIOR WESTWARD INTO CNTRL
UPPER MI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 451 AM EDT SUN MAR 22 2015
AT 12Z MONDAY UPPER MI WILL STILL BE IN BETWEEN SYSTEMS. THE NEXT
SHORTWAVE WILL BE OVER S MANITOBA. HIGH PRESSURE WILL STILL BE THE
MAIN FEATURE...CENTERED OVER THE E HALF OF ONTARIO/E LAKE SUPERIOR/E
UPPER MI.
NOT EXPECTING MUCH OUT OF THE SHORTWAVE TO THE NW AS IT WORKS
THROUGH A REGION OF PRETTY DRY AIR. THE PRECIP OVER NW MN MONDAY
AFTERNOON IS EXPECTED TO ALL BUT DRY UP AS IT CROSSES MN AND W LAKE
SUPERIOR. DID KEEP JUST A SMALL POCKET OF SLIGHT CHANCE POPS OVER W
LAKE SUPERIOR MONDAY NIGHT...AND N LAKE SUPERIOR LATE MONDAY
NIGHT/TUESDAY MORNING.
THE SFC HIGH WILL SLIDE TO THE SE OVER FAR SE ONTARIO/S QUEBEC BY
TUESDAY MORNING. LOOK FOR THE RETURN OF S WINDS ON TUESDAY...WITH
850MB TEMPS RISING TO C TO -2C BY THE END OF THE DAY. DOWNSLOPE
AREAS AND LOCATIONS ALONG THE WI BORDER MAY SEE TEMPS IN THE UPPER
40S TO NEAR 50F...ESPECIALLY IF THE ANTICIPATED MOSTLY SUNNY SKY PANS
OUT.
SLOWED DOWN/BROUGHT MORE TEMPORAL DEFINITION TO THE INCOMING SNOW
AND MIXED PRECIP LATE TUESDAY NIGHT. THERE IS STILL ENOUGH
UNCERTAINTY IN THE FCST SOLUTIONS TO KEEP THE MENTION OF SEVERAL
INCHES OF SNOW POSSIBLE IN THE HWO FOR LATE TUESDAY NIGHT THROUGH
WEDNESDAY MORNING.
EXPECT SFC LOWS FROM THE DAKOTAS AND E KS TUESDAY AFTERNOON TO MERGE
ACROSS WI BY DAYBREAK WEDNESDAY. 850MB WINDS OUT OF THE S AT 40-
50KTS WILL BE OUT AHEAD OF THE LOW /ACROSS LAKE MI AT 12Z
WEDNESDAY/...USHERING IN WARMER AIR. LOOKS LIKE A GOOD CHANCE OF
MIXED PRECIP STILL OVER S CENTRAL AND E UPPER MI WEDNESDAY
AFTERNOON...WHICH WILL MINIMIZE THE POTENTIAL FOR QUICKLY
ACCUMULATING SNOW. DEF/LIKELY SNOW WILL EXIT WEDNESDAY AFTERNOON AS
THE CONSOLIDATED LOW EXITS FROM E UPPER MI TO E ONTARIO.
OTHERWISE...PRECIP SHOULD STAY MAINLY IN THE FORM OF SNOW NW OF A
LINE FROM IRON TO MUNISING. MODERATE SNOW WILL BE POSSIBLE OVER THE
FAR W...DIMINISHING TO A GOOD CHANCE AS STEADY N TO NW WINDS TAKE
HOLD AND COLDER AIR PUSHES IN ON THURSDAY. 850MB TEMPS WILL FALL TO -
18 TO -22C THURSDAY AFTERNOON INTO EARLY FRIDAY MORNING.
LIGHTER AND LESS FAVORABLE W TO SW WINDS SHOULD PUSH IN LATER
FRIDAY...AS ANOTHER AREA OF HIGH PRESSURE SINKS IN FROM S CENTRAL
CANADA. LOOKING FARTHER OUT...MODELS ARE HINTING AT ANOTHER SYSTEM
FOR THE END OF THE WEEKEND. STAY TUNED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 140 PM EDT SUN MAR 22 2015
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD AS A HIGH
PRESSURE RIDGE REMAINS OVER THE AREA. THIS WILL LEAD TO LIGHT WINDS
AFTER DIURNAL MIXING DIMINISHES THIS EVENING. A DISTURBANCE MOVING
THROUGH SOUTHERN MINNESOTA/WISCONSIN WILL STREAM HIGH CLOUDS ACROSS
UPPER MICHIGAN LATER THIS EVENING INTO MONDAY. THE CLOUDS ARE
EXPECTED TO BE THE THICKEST OVER THE SOUTHWEST HALF OF UPPER
MICHIGAN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 502 AM EDT SUN MAR 22 2015
JUST AHEAD OF A HIGH PRES RIDGE EXTENDING SE OVER WRN LAKE
SUPERIOR...NW WINDS OVER FAR ERN LAKE SUPERIOR WILL PROBABLY
INCREASE TO 15-25KT TODAY. OTHERWISE...WINDS WILL BE UNDER 20KT.
WINDS WILL THEN BE UNDER 20KT ACROSS THE LAKE TONIGHT AS THE HIGH
PRES RIDGE DRIFTS E. WINDS SHOULD GENERALLY REMAIN UNDER 20KT MON
INTO EARLY TUE AS PRES GRADIENT REMAINS WEAK. ATTENTION THEN TURNS
TO DEEPENING LOW PRES WHICH WILL TRACK FROM THE CNTRL PLAINS TUE TO
EASTERN UPPER MI WED AFTN. AHEAD OF THIS SYSTEM...SE TO E WINDS WILL
INCREASE TUE NIGHT TO 15-25KT ACROSS MUCH OF LAKE SUPERIOR. WINDS
WILL THEN VEER AROUND TO THE N WED/THU. WHILE 15-25KT WINDS WILL
PROBABLY BE COMMON...WILL NEED TO WATCH FOR STRONGER WINDS UP TO
30KT AND POTENTIALLY UP TO GALE FORCE AT SOME POINT WED INTO EARLY
THU FOR PARTS OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...SRF
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
729 AM EDT SUN MAR 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 502 AM EDT SUN MAR 22 2015
DESPITE 850MB TEMPS AROUND -17C PER LATEST RAP ANALYSIS...THERE ARE
NO LAKE EFFECT CLOUDS DEVELOPING OFF THE OPEN WATER OF NCNTRL LAKE
SUPERIOR. EVEN OFF THE OPEN WATER EXTENDING FROM THE KEWEENAW TO
MUNISING...THERE WAS A LITTLE BURST OF LES EARLIER IN THE NIGHT INTO
ALGER COUNTY...BUT THAT HAS SINCE DISSIPATED. CONVERGENCE HAS
RECENTLY STRENGTHENED OVER THAT OPEN WATER AREA AS A WIND SHIFT TO
THE ENE IS PROGRESSING TOWARD THE MARQUETTE COUNTY SHORELINE WHERE
LAND BREEZE IS EVIDENT. IN JUST IN THE LAST HR...THIS HAS RESULTED
IN NEW LIGHT LES DEVELOPMENT OVER FAR ERN MARQUETTE COUNTY.
OTHERWISE...AS OF 09Z...THAT IS IT FOR LES AND EVEN LAKE EFFECT
CLOUDS OFF LAKE SUPERIOR. UPSTREAM 00Z SOUNDINGS AT KINL/CYPL TELL
THE STORY AS NOT ONLY WAS THE AIR MASS DRY IN THE LOW TO MID
LEVELS...BUT BOTH SOUNDINGS ALSO EXHIBITED THE HOSTILE FOR LES
INVERTED V LOOK.
WOULD EXPECT A CONTINUED UPTICK IN LES OFF SCNTRL LAKE SUPERIOR INTO
FAR ERN MARQUETTE COUNTY AND ALGER COUNTY EARLY THIS MORNING AS WE
APPROACH THE COOLEST PART OF THE DIURNAL CYCLE/MOST FAVORABLE TIME
OF DAY FOR LES AT THIS TIME OF YEAR. THAT SAID...IT WON`T BE MORE
THAN LIGHT SNOW SHOWERS AND FLURRIES WITH ANY ACCUMULATION UNDER 1
INCH. THE DISRUPTIVE EFFECT OF DAYTIME HEATING AT THIS TIME OF YEAR
COMBINED WITH 850MB THERMAL TROF SHIFTING E WILL BRING AN END TO THE
LIGHT LES EARLY THIS AFTN. ACROSS THE REST OF THE FCST AREA...EXPECT
A PARTLY TO MOSTLY SUNNY DAY WITH HIGHS IN THE 20S ACROSS MOST OF
THE N AND E TO THE 30S TOWARD THE MI/WI BORDER.
SHORTWAVE MOVING ACROSS THE DAKOTAS TODAY AND INTO THE WRN GREAT
LAKES TONIGHT WILL WEAKEN AS IT ENCOUNTERS INCREASINGLY CONFLUENT
FLOW. MODELS SHOW THIS WAVE SPREADING PCPN ACROSS MN INTO WI. MODELS
WHICH HAD PREVIOUSLY BROUGHT THE PCPN TO NEAR THE MI/WI BORDER
TONIGHT HAVE TRENDED S WITH THE NRN EDGE OF THE PCPN. GIVEN THE
CONFLUENT FLOW OVER THE UPPER LAKES...ESTABLISHED ARCTIC AIR AND
CONTINUED DRY AIR EMANATING FROM THE SFC HIGH PRES AREA WHICH WILL
BE SLOWLY DRIFTING E OF HERE...A DRY FCST IS THE WAY TO GO TONIGHT.
MIN TEMPS TONIGHT COULD BE QUITE LOW...ESPECIALLY OVER THE ERN FCST
AREA WHERE HIGH/MID CLOUDS WILL BE THINNEST AND WHERE THERE WILL BE
LIGHT ENE WINDS OFF ONTARIO. EXPECT TRADITIONAL COLD SPOTS TO FALL
TO NEAR 0F OR EVEN BLO. DEPENDING ON THICKNESS OF CLOUDS...SINGLE
DIGITS ABOVE ZERO MAY BE COMMON IN THE INTERIOR WESTWARD INTO CNTRL
UPPER MI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 451 AM EDT SUN MAR 22 2015
AT 12Z MONDAY UPPER MI WILL STILL BE IN BETWEEN SYSTEMS. THE NEXT
SHORTWAVE WILL BE OVER S MANITOBA. HIGH PRESSURE WILL STILL BE THE
MAIN FEATURE...CENTERED OVER THE E HALF OF ONTARIO/E LAKE SUPERIOR/E
UPPER MI.
NOT EXPECTING MUCH OUT OF THE SHORTWAVE TO THE NW AS IT WORKS
THROUGH A REGION OF PRETTY DRY AIR. THE PRECIP OVER NW MN MONDAY
AFTERNOON IS EXPECTED TO ALL BUT DRY UP AS IT CROSSES MN AND W LAKE
SUPERIOR. DID KEEP JUST A SMALL POCKET OF SLIGHT CHANCE POPS OVER W
LAKE SUPERIOR MONDAY NIGHT...AND N LAKE SUPERIOR LATE MONDAY
NIGHT/TUESDAY MORNING.
THE SFC HIGH WILL SLIDE TO THE SE OVER FAR SE ONTARIO/S QUEBEC BY
TUESDAY MORNING. LOOK FOR THE RETURN OF S WINDS ON TUESDAY...WITH
850MB TEMPS RISING TO C TO -2C BY THE END OF THE DAY. DOWNSLOPE
AREAS AND LOCATIONS ALONG THE WI BORDER MAY SEE TEMPS IN THE UPPER
40S TO NEAR 50F...ESPECIALLY IF THE ANTICIPATED MOSTLY SUNNY SKY PANS
OUT.
SLOWED DOWN/BROUGHT MORE TEMPORAL DEFINITION TO THE INCOMING SNOW
AND MIXED PRECIP LATE TUESDAY NIGHT. THERE IS STILL ENOUGH
UNCERTAINTY IN THE FCST SOLUTIONS TO KEEP THE MENTION OF SEVERAL
INCHES OF SNOW POSSIBLE IN THE HWO FOR LATE TUESDAY NIGHT THROUGH
WEDNESDAY MORNING.
EXPECT SFC LOWS FROM THE DAKOTAS AND E KS TUESDAY AFTERNOON TO MERGE
ACROSS WI BY DAYBREAK WEDNESDAY. 850MB WINDS OUT OF THE S AT 40-
50KTS WILL BE OUT AHEAD OF THE LOW /ACROSS LAKE MI AT 12Z
WEDNESDAY/...USHERING IN WARMER AIR. LOOKS LIKE A GOOD CHANCE OF
MIXED PRECIP STILL OVER S CENTRAL AND E UPPER MI WEDNESDAY
AFTERNOON...WHICH WILL MINIMIZE THE POTENTIAL FOR QUICKLY
ACCUMULATING SNOW. DEF/LIKELY SNOW WILL EXIT WEDNESDAY AFTERNOON AS
THE CONSOLIDATED LOW EXITS FROM E UPPER MI TO E ONTARIO.
OTHERWISE...PRECIP SHOULD STAY MAINLY IN THE FORM OF SNOW NW OF A
LINE FROM IRON TO MUNISING. MODERATE SNOW WILL BE POSSIBLE OVER THE
FAR W...DIMINISHING TO A GOOD CHANCE AS STEADY N TO NW WINDS TAKE
HOLD AND COLDER AIR PUSHES IN ON THURSDAY. 850MB TEMPS WILL FALL TO -
18 TO -22C THURSDAY AFTERNOON INTO EARLY FRIDAY MORNING.
LIGHTER AND LESS FAVORABLE W TO SW WINDS SHOULD PUSH IN LATER
FRIDAY...AS ANOTHER AREA OF HIGH PRESSURE SINKS IN FROM S CENTRAL
CANADA. LOOKING FARTHER OUT...MODELS ARE HINTING AT ANOTHER SYSTEM
FOR THE END OF THE WEEKEND. STAY TUNED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 729 AM EDT SUN MAR 22 2015
DRY AIR MASS ASSOCIATED WITH HIGH PRES DRIFTING OVER NORTHERN
ONTARIO TODAY AND TONIGHT WILL RESULT IN VFR CONDITIONS AT
KIWD/KCMX/KSAW THRU THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 502 AM EDT SUN MAR 22 2015
JUST AHEAD OF A HIGH PRES RIDGE EXTENDING SE OVER WRN LAKE
SUPERIOR...NW WINDS OVER FAR ERN LAKE SUPERIOR WILL PROBABLY
INCREASE TO 15-25KT TODAY. OTHERWISE...WINDS WILL BE UNDER 20KT.
WINDS WILL THEN BE UNDER 20KT ACROSS THE LAKE TONIGHT AS THE HIGH
PRES RIDGE DRIFTS E. WINDS SHOULD GENERALLY REMAIN UNDER 20KT MON
INTO EARLY TUE AS PRES GRADIENT REMAINS WEAK. ATTENTION THEN TURNS
TO DEEPENING LOW PRES WHICH WILL TRACK FROM THE CNTRL PLAINS TUE TO
EASTERN UPPER MI WED AFTN. AHEAD OF THIS SYSTEM...SE TO E WINDS WILL
INCREASE TUE NIGHT TO 15-25KT ACROSS MUCH OF LAKE SUPERIOR. WINDS
WILL THEN VEER AROUND TO THE N WED/THU. WHILE 15-25KT WINDS WILL
PROBABLY BE COMMON...WILL NEED TO WATCH FOR STRONGER WINDS UP TO
30KT AND POTENTIALLY UP TO GALE FORCE AT SOME POINT WED INTO EARLY
THU FOR PARTS OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
502 AM EDT SUN MAR 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 502 AM EDT SUN MAR 22 2015
DESPITE 850MB TEMPS AROUND -17C PER LATEST RAP ANALYSIS...THERE ARE
NO LAKE EFFECT CLOUDS DEVELOPING OFF THE OPEN WATER OF NCNTRL LAKE
SUPERIOR. EVEN OFF THE OPEN WATER EXTENDING FROM THE KEWEENAW TO
MUNISING...THERE WAS A LITTLE BURST OF LES EARLIER IN THE NIGHT INTO
ALGER COUNTY...BUT THAT HAS SINCE DISSIPATED. CONVERGENCE HAS
RECENTLY STRENGTHENED OVER THAT OPEN WATER AREA AS A WIND SHIFT TO
THE ENE IS PROGRESSING TOWARD THE MARQUETTE COUNTY SHORELINE WHERE
LAND BREEZE IS EVIDENT. IN JUST IN THE LAST HR...THIS HAS RESULTED
IN NEW LIGHT LES DEVELOPMENT OVER FAR ERN MARQUETTE COUNTY.
OTHERWISE...AS OF 09Z...THAT IS IT FOR LES AND EVEN LAKE EFFECT
CLOUDS OFF LAKE SUPERIOR. UPSTREAM 00Z SOUNDINGS AT KINL/CYPL TELL
THE STORY AS NOT ONLY WAS THE AIR MASS DRY IN THE LOW TO MID
LEVELS...BUT BOTH SOUNDINGS ALSO EXHIBITED THE HOSTILE FOR LES
INVERTED V LOOK.
WOULD EXPECT A CONTINUED UPTICK IN LES OFF SCNTRL LAKE SUPERIOR INTO
FAR ERN MARQUETTE COUNTY AND ALGER COUNTY EARLY THIS MORNING AS WE
APPROACH THE COOLEST PART OF THE DIURNAL CYCLE/MOST FAVORABLE TIME
OF DAY FOR LES AT THIS TIME OF YEAR. THAT SAID...IT WON`T BE MORE
THAN LIGHT SNOW SHOWERS AND FLURRIES WITH ANY ACCUMULATION UNDER 1
INCH. THE DISRUPTIVE EFFECT OF DAYTIME HEATING AT THIS TIME OF YEAR
COMBINED WITH 850MB THERMAL TROF SHIFTING E WILL BRING AN END TO THE
LIGHT LES EARLY THIS AFTN. ACROSS THE REST OF THE FCST AREA...EXPECT
A PARTLY TO MOSTLY SUNNY DAY WITH HIGHS IN THE 20S ACROSS MOST OF
THE N AND E TO THE 30S TOWARD THE MI/WI BORDER.
SHORTWAVE MOVING ACROSS THE DAKOTAS TODAY AND INTO THE WRN GREAT
LAKES TONIGHT WILL WEAKEN AS IT ENCOUNTERS INCREASINGLY CONFLUENT
FLOW. MODELS SHOW THIS WAVE SPREADING PCPN ACROSS MN INTO WI. MODELS
WHICH HAD PREVIOUSLY BROUGHT THE PCPN TO NEAR THE MI/WI BORDER
TONIGHT HAVE TRENDED S WITH THE NRN EDGE OF THE PCPN. GIVEN THE
CONFLUENT FLOW OVER THE UPPER LAKES...ESTABLISHED ARCTIC AIR AND
CONTINUED DRY AIR EMANATING FROM THE SFC HIGH PRES AREA WHICH WILL
BE SLOWLY DRIFTING E OF HERE...A DRY FCST IS THE WAY TO GO TONIGHT.
MIN TEMPS TONIGHT COULD BE QUITE LOW...ESPECIALLY OVER THE ERN FCST
AREA WHERE HIGH/MID CLOUDS WILL BE THINNEST AND WHERE THERE WILL BE
LIGHT ENE WINDS OFF ONTARIO. EXPECT TRADITIONAL COLD SPOTS TO FALL
TO NEAR 0F OR EVEN BLO. DEPENDING ON THICKNESS OF CLOUDS...SINGLE
DIGITS ABOVE ZERO MAY BE COMMON IN THE INTERIOR WESTWARD INTO CNTRL
UPPER MI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 451 AM EDT SUN MAR 22 2015
AT 12Z MONDAY UPPER MI WILL STILL BE IN BETWEEN SYSTEMS. THE NEXT
SHORTWAVE WILL BE OVER S MANITOBA. HIGH PRESSURE WILL STILL BE THE
MAIN FEATURE...CENTERED OVER THE E HALF OF ONTARIO/E LAKE SUPERIOR/E
UPPER MI.
NOT EXPECTING MUCH OUT OF THE SHORTWAVE TO THE NW AS IT WORKS
THROUGH A REGION OF PRETTY DRY AIR. THE PRECIP OVER NW MN MONDAY
AFTERNOON IS EXPECTED TO ALL BUT DRY UP AS IT CROSSES MN AND W LAKE
SUPERIOR. DID KEEP JUST A SMALL POCKET OF SLIGHT CHANCE POPS OVER W
LAKE SUPERIOR MONDAY NIGHT...AND N LAKE SUPERIOR LATE MONDAY
NIGHT/TUESDAY MORNING.
THE SFC HIGH WILL SLIDE TO THE SE OVER FAR SE ONTARIO/S QUEBEC BY
TUESDAY MORNING. LOOK FOR THE RETURN OF S WINDS ON TUESDAY...WITH
850MB TEMPS RISING TO C TO -2C BY THE END OF THE DAY. DOWNSLOPE
AREAS AND LOCATIONS ALONG THE WI BORDER MAY SEE TEMPS IN THE UPPER
40S TO NEAR 50F...ESPECIALLY IF THE ANTICIPATED MOSTLY SUNNY SKY PANS
OUT.
SLOWED DOWN/BROUGHT MORE TEMPORAL DEFINITION TO THE INCOMING SNOW
AND MIXED PRECIP LATE TUESDAY NIGHT. THERE IS STILL ENOUGH
UNCERTAINTY IN THE FCST SOLUTIONS TO KEEP THE MENTION OF SEVERAL
INCHES OF SNOW POSSIBLE IN THE HWO FOR LATE TUESDAY NIGHT THROUGH
WEDNESDAY MORNING.
EXPECT SFC LOWS FROM THE DAKOTAS AND E KS TUESDAY AFTERNOON TO MERGE
ACROSS WI BY DAYBREAK WEDNESDAY. 850MB WINDS OUT OF THE S AT 40-
50KTS WILL BE OUT AHEAD OF THE LOW /ACROSS LAKE MI AT 12Z
WEDNESDAY/...USHERING IN WARMER AIR. LOOKS LIKE A GOOD CHANCE OF
MIXED PRECIP STILL OVER S CENTRAL AND E UPPER MI WEDNESDAY
AFTERNOON...WHICH WILL MINIMIZE THE POTENTIAL FOR QUICKLY
ACCUMULATING SNOW. DEF/LIKELY SNOW WILL EXIT WEDNESDAY AFTERNOON AS
THE CONSOLIDATED LOW EXITS FROM E UPPER MI TO E ONTARIO.
OTHERWISE...PRECIP SHOULD STAY MAINLY IN THE FORM OF SNOW NW OF A
LINE FROM IRON TO MUNISING. MODERATE SNOW WILL BE POSSIBLE OVER THE
FAR W...DIMINISHING TO A GOOD CHANCE AS STEADY N TO NW WINDS TAKE
HOLD AND COLDER AIR PUSHES IN ON THURSDAY. 850MB TEMPS WILL FALL TO -
18 TO -22C THURSDAY AFTERNOON INTO EARLY FRIDAY MORNING.
LIGHTER AND LESS FAVORABLE W TO SW WINDS SHOULD PUSH IN LATER
FRIDAY...AS ANOTHER AREA OF HIGH PRESSURE SINKS IN FROM S CENTRAL
CANADA. LOOKING FARTHER OUT...MODELS ARE HINTING AT ANOTHER SYSTEM
FOR THE END OF THE WEEKEND. STAY TUNED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 133 AM EDT SUN MAR 22 2015
A WEAK SURGE OF MOISTURE MOVING IN OVERNIGHT SHOULD RESULT IN
INCREASING LAKE EFFECT CLOUD COVERAGE AS WINDS VEER TO THE NORTH-
NORTHWEST. KSAW HAS THE BEST OPPORTUNITY FOR HIGH END MVFR CEILINGS.
WITH A MORE ANTICYCLONIC FLOW OVER THE WEST...CONFIDENCE IS TOO LOW
TO INCLUDE ANY MVFR MENTION AT KIWD/KCMX. THE MOISTURE WILL DEPART
THIS MORNING AND WINDS WILL BACK...LEADING TO DIMINISHING CLOUDS/LES
AS HIGH PRES RIDGE CONTINUES TO MOVE OVER THE REGION.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 502 AM EDT SUN MAR 22 2015
JUST AHEAD OF A HIGH PRES RIDGE EXTENDING SE OVER WRN LAKE
SUPERIOR...NW WINDS OVER FAR ERN LAKE SUPERIOR WILL PROBABLY
INCREASE TO 15-25KT TODAY. OTHERWISE...WINDS WILL BE UNDER 20KT.
WINDS WILL THEN BE UNDER 20KT ACROSS THE LAKE TONIGHT AS THE HIGH
PRES RIDGE DRIFTS E. WINDS SHOULD GENERALLY REMAIN UNDER 20KT MON
INTO EARLY TUE AS PRES GRADIENT REMAINS WEAK. ATTENTION THEN TURNS
TO DEEPENING LOW PRES WHICH WILL TRACK FROM THE CNTRL PLAINS TUE TO
EASTERN UPPER MI WED AFTN. AHEAD OF THIS SYSTEM...SE TO E WINDS WILL
INCREASE TUE NIGHT TO 15-25KT ACROSS MUCH OF LAKE SUPERIOR. WINDS
WILL THEN VEER AROUND TO THE N WED/THU. WHILE 15-25KT WINDS WILL
PROBABLY BE COMMON...WILL NEED TO WATCH FOR STRONGER WINDS UP TO
30KT AND POTENTIALLY UP TO GALE FORCE AT SOME POINT WED INTO EARLY
THU FOR PARTS OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
656 AM CDT SUN MAR 22 2015
.UPDATE...FOR 12Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT SUN MAR 22 2015
AN EARLY SPRING ACCUMULATING SNOWFALL EVENT IS ON TRACK FOR LATER
TODAY AND TONIGHT...AS A SHORTWAVE TROUGH ADVANCES INTO THE AREA
FROM THE NORTHERN ROCKIES. STILL LOOKS LIKE A 75 MILE WIDE BAND OF 3-
6 INCH ACCUMULATIONS WILL OCCUR FROM CENTRAL TO SOUTHEASTERN
MINNESOTA.
DESPITE THE FACT THIS SYSTEM IS NOW IN THE NEAR-TERM PORTION OF THE
FORECAST...A FEW UNCERTAINTIES STILL REMAIN. THE FIRST UNKNOWN IS
HOW LONG IT WILL TAKE THE DRY LOWER LAYERS OF THE ATMOSPHERE /UNDER
THE INFLUENCE OF DRY NORTHEAST FLOW/ TO SATURATE. THIS WILL MEAN THE
FIRST WARM AIR ADVECTION WAVE COULD ADD OR SUBTRACT 1-2 INCHES FROM
EVENT TOTALS. GIVEN DEWPOINTS ARE IN THE SINGLE DIGITS TO LOWER
TEENS...AM LEANING TOWARD IT TAKING LONGER FOR US TO SEE SATURATION
AND THEREFORE A SLIGHTLY DELAYED SNOWFALL ONSET. A MORE PROBABLE
SCENARIO IS THAT SNOW BEGINS ACROSS CENTRAL MN BETWEEN 16Z AND
18Z...AND THEN BLOSSOMS NOTABLY AFTER 21Z WHEN UPWARD MOTION
MAXIMIZES. HAVE MAINTAINED THE HIGHEST POPS IN THE LATE AFTERNOON
AND EARLY EVENING. THE CURRENT ADVISORY LOOKS TO BE IN GOOD
SHAPE...WITH 3 TO 6 INCH ACCUMULATIONS. COULD SEE AMOUNTS SNEAK INTO
WARNING CRITERIA RANGES /6+ INCHES/...HOWEVER GIVEN THE HUNCH THAT
DRIER AIR MIGHT BE A BIT MORE IMPACTFUL THAN SEVERAL MODELS
DEPICT...WILL HOLD TIGHT WITH THE ADVISORY FOR NOW. COULD ALSO HEAR
SOME THUNDER ALONG THE IOWA BORDER...BUT FOR THE MOST PART DO NOT
ANTICIPATE ENHANCED SNOWFALL RATES DUE TO THUNDERSNOW.
AS THE DENDRITIC LAYER LOSES SATURATION AS THE EVENT IS WINDING
DOWN...COULD SEE LIGHT FREEZING DRIZZLE FOR A FEW HOURS
TONIGHT BEFORE PRECIPITATION SHUTS OFF ENTIRELY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT SUN MAR 22 2015
THE LONG TERM PORTION OF THE FORECAST PUTS A MOMENTARY PAUSE IN OUR
SPRING WARMUP AS IT WILL FEATURE HIGHS STRUGGLING TO GET INTO THE
40S NEXT WORK WEEK...HAVE AN OPPORTUNITY FOR GETTING LOWS DOWN INTO
THE SINGLE DIGITS...AND IS STARTING TO LOOK MORE LIKELY THAT IT WILL
OFFER YET ANOTHER ACCUMULATING SNOW TUESDAY NIGHT AND WEDNESDAY.
WE GET THINGS KICKED OFF ON MONDAY WITH TODAYS PRECIP CLEARING SE MN
EARLY MONDAY MORNING. IN ITS WAKE WE WILL HAVE CLOUDY SKIES AND
SOUTHEAST WINDS. GIVEN THE ANTICIPATION OF SEVERAL INCHES OF SNOW
BEING ON THE GROUND...FOLLOWED THE MODEL BLEND IDEA WITH COOLING
HIGHS ALONG A MORRIS TO ROCHESTER LINE...WHERE HIGHS IN THE 30S ARE
LOOKING LIKELY. IN FACT...WE MAY NOT BE COLD ENOUGH WITH HIGHS
WITHIN THE SWATH WHERE SNOW EVENTUALLY FALLS.
OF MORE IMPORTANCE THOUGH ON MONDAY WILL BE THE NEGATIVELY TILTED H5
TROUGH WORKING ACROSS THE ROCKIES...WHICH WILL HEAD ACROSS THE UPPER
MS VALLEY TUESDAY NIGHT. THERE WERE THREE SIGNIFICANT TRENDS WITH THE
00Z MODEL RUNS WITH THIS SYSTEM. THEY ALL SHOW THIS SYSTEM BEING
SLOWER...FARTHER SOUTH...AND COLDER. ALL OF THIS POINTS TO
INCREASING POTENTIAL FOR ANOTHER ROUND OF ACCUMULATING
SNOWFALL...ESPECIALLY ACROSS CENTRAL/NRN MN INTO NW WI. THESE SHIFTS
REPRESENT THE GFS SLOWING MORE TOWARD THE ECMWF /WHICH SLOWED DOWN
AS WELL/ AND THE ECMWF SHIFTING SOUTH WITH THE SFC LOW...MORE TOWARD
THE GEM/GFS. THIS SLOWER TREND IS LIKELY DUE TO THE FACT THAT THE SE
LOW LEVEL WINDS WE WILL HAVE MONDAY/MONDAY NIGHT WILL BE EMANATING
FROM A VERY DRY SFC HIGH OVER THE GREAT LAKES. IN FACT...THIS IS
THE SAME SFC HIGH THAT BROUGHT US DEWPS IN THE SINGLE DIGITS ON
SATURDAY AND IS PLAYING HAVOC WITH WHEN PRECIP WILL START TODAY. WE
STILL HAVE LIKELY/DEFINITE POPS FOR THIS SYSTEM...THEY ARE JUST MORE
TUESDAY NIGHT AS OPPOSED TO TUESDAY AFTERNOON/EVENING.
THE SOUTHWARD SHIFT AND LATER ARRIVAL OF THIS PRECIP IS NOW STARTING
TO BRING P-TYPE MUCH MORE INTO QUESTION. DID COOL TEMPS TUESDAY
NIGHT SOME FROM PREVIOUS FORECAST...BUT NOT ENOUGH TO BRING ALL SNOW
SOUTH OF CENTRAL MN AND NW WI. WHAT IS INTERESTING NOW IS THAT THE
SFC LOW TRACK SEEN WITH THE ECMWF/GEM/GFS FROM CENTRAL IA TO
NORTH CENTRAL WI IS A CLIMATOLOGICALLY FAVORED ONE FOR BRINGING HEAVY
SNOWS INTO THE TWIN CITIES...SO WE MAY HAVE TO RATCHET TO FORECAST
MORE IN THE SNOW DIRECTION IF THIS TREND HOLDS IN THE 12Z MODEL
CYCLE. RIGHT NOW...WE HAVE A COUPLE INCHES OF SNOW ALONG THE NRN
BORDER OF THE MPX AREA...WITH THE HEAVIEST SNOW /POSSIBLY PUSHING
DOUBLE DIGITS IN TOTALS/ FALLING ACROSS NRN MN.
FOR WEDNESDAY MODELS CONTINUE TO SHOW AN INVERTED TROUGH AND
ASSOCIATED DEFORMATION ZONE HANGING UP TO THE WEST OF THE SFC LOW.
THIS LOOKS TO BRING LIGHT PRECIP MOST OF THE DAY TO NORTHERN
MN...WITH THE REMNANTS OF THAT DEFORMATION BAND PUSHING ACROSS ERN
MN/WRN WI WEDNESDAY NIGHT. IN FACT...THE GFS SHOWS SNOW LINGERING
ACROSS THE AREA THROUGH THURSDAY BEFORE AN ARCTIC FRONT FINALLY
PUSHES THE MOISTURE SOUTHEAST OF THE AREA.
AS FOR THE ARCTIC FRONT...IT WILL BE PUSHED THROUGH BY A 1035MB THAT
THE GFS/ECMWF SHOW BEING CENTERED OVER MN BY FRIDAY MORNING.
DEPENDING ON CLOUD COVER/SNOW COVER...THIS PATTERN WOULD GIVE US THE
OPPORTUNITY TO GET LOWS BACK DOWN IN THE SINGLE DIGITS...WHICH IS
EXACTLY WHAT THE ECMWF HAS ALL BUT SOUTH CENTRAL MN DOING FRIDAY
MORNING. STUCK WITH A BLENDED FORECAST FOR NOW...WHICH KEPT LOWS
FRIDAY MORNING UP IN THE TEENS AND 20S...BUT WE MAY NEED TO TAKE A
GOOD 10 DEGREES OFF OF THAT DEPENDING ON HOW THINGS UNFOLD.
FOR THE WEEKEND...THE CLIPPER THE ECMWF HAD BEEN SHOWING SLIDING
ACROSS THE AREA FRIDAY NIGHT IS NOW GONE...SIMILAR TO WHAT THE GFS
HAS BEEN GOING WITH. FOR CONTINUITY PURPOSES LEFT SOME SLIGHT
CHANCE POPS IN FOR FRIDAY NIGHT ACROSS THE ERN HALF OF THE
AREA...BUT THOSE COULD PROBABLY BE REMOVED IF THE ECMWF COMES IN DRY
AGAIN WITH ITS 22.12 RUN. THE ECMWF/GFS ARE IN GOOD AGREEMENT THIS
FAR OUT ON THE NEXT SYSTEM THOUGH COMING ACROSS THE AREA SAT
NIGHT/SUNDAY. BOTH MODELS SHOW A STRONG CLIPPER DIVING SOUTHEAST
ACROSS NRN MN AND NRN WI. THIS WOULD PLACE THE MPX AREA INTO ITS
WARM SECTOR SATURDAY/SATURDAY NIGHT BEFORE GETTING ANOTHER PUSH OF
COLD AIR TO END OF THE WEEKEND. THIS TRACK AT THE MOMENT WOULD KEEP
ANY ACCUMULATING SNOW WITH THIS SYSTEM WELL NORTHEAST OF THE MPX
AREA. AT THE VERY LEAST...THIS SYSTEM WILL BRING RATHER
BLUSTERY WINDS BOTH AHEAD OF AND BEHIND ITS COLD FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 655 AM CDT SUN MAR 22 2015
THE MAIN FORECAST CONCERN CONTINUES TO BE TIMING/PLACEMENT OF
PRECIPITATION TODAY AND TONIGHT. DESPITE THE AMOUNT OF DRY LLVL
AIR WITH THE NORTHEAST FLOW...WE ARE BEGINNING TO SEE SOME RADAR
RETURNS REACHING THE GROUND ACROSS SOUTHWEST MN. LEANED TOWARD
THE 22.10Z HRRR WHICH EXPANDS THE AREA OF SPOTTY SHOWERS
NORTHEAST ACROSS THE AREA THIS MORNING...BUT REALLY BLOSSOMS
THINGS DURING THE AFTERNOON AND EVENING AS THE STRONGER FORCING
ARRIVES. HAVE THEREFORE FEATURED THE LOWEST CONDITIONS /IFR-LIFR/
BETWEEN 21Z AND 04Z...WHEN SNOW SHOULD BE MODERATE TO HEAVY. WINDS
ALSO LOOK A BIG STRONGER THAN PREVIOUSLY EXPECTED...SO HAVE
INCLUDED SOME GUSTS.
KMSP...
THE WINDOW FOR VFR CONDITIONS IS SHRINKING...WITH PRECIPITATION
BEGINNING TO HIT THE GROUND OVER SOUTHWEST MN. EXPECT THIS AREA OF
PRECIPITATION TO NEAR THE FIELD AROUND 17Z...WITH CIGS/VSBYS
QUICKLY DECLINING ONCE THE SNOW BEGINS. THE WORST CONDITIONS
/IFR-LIFR/ ARE LIKELY FROM 20Z SUNDAY AFTERNOON THROUGH LATE
EVENING AS THE INTENSITY OF THE SNOW INCREASES...WITH WINDS
VEERING TO EASTERLY AT 10-15 KTS AROUND 090 DEGREES. SNOW WILL
DIMINISH OVERNIGHT...ENDING BY THE EARLY MORNING MONDAY.
ACCUMULATIONS OF 3 TO 5 INCHES ARE EXPECTED AT KMSP...WITH 3/4
INCH RATE ACCUMULATIONS APPEARING POSSIBLE BETWEEN 21Z AND 02Z.
/OUTLOOK FOR KMSP/
MON...MVFR. WINDS SE 5-10 KTS.
TUE...MVFR/IFR WITH -RA LATE. WINDS SE 15G20 KTS.
WED...MVFR/IFR WITH -RA/-SN. WINDS W 15G25 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 1 AM CDT
MONDAY FOR MNZ049-051-057>063-066>070-076>078-085.
WI...WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 1 AM CDT
MONDAY FOR WIZ023-024-026.
&&
$$
SHORT TERM...LS
LONG TERM...MPG
AVIATION...LS
AREA FORECAST DISCUSSION
NWS JACKSON MS
955 PM CDT MON MAR 23 2015
.UPDATE...THE SKIES HAVE CLEARED OVER MUCH OF THE CWA THIS EVENING
BUT SOME STRATUS WAS HANGING ON OVER THE SOUTHEAST ALONG INTERSTATE
59. THESE CLOUDS SHOULD SHIFT SOUTHEAST OF THE AREA BY MIDNIGHT.
UNDER CLEAR SKIES AND NEAR CALM WINDS GOOD RADIATIONAL COOLING
SHOULD ALLOW TEMPERATURES TO ACHIEVE FORECAST LOWS AND SOME PATCHY
DENSE FOG TO DEVELOP. ADJUSTED CLOUD COVER BUT NO OTHER CHANGES
NEEDED. /22/
&&
.AVIATION...STRATUS WAS STILL BEING OBSERVED ALONG THE I-59 CORRIDOR
BUT SHOULD SHOULD BE SE OF THE AREA BY 05Z. CLEAR SKIES WERE BEING
OBSERVED THIS EVENING ELSEWHERE. CLR SKIES AND NEAR CALM WIND WILL
ALLOW FOR FOG DEVELOPMENT AFTER MIDNIGHT. MVFR/IFR VISIBILITIES ARE
EXPECTED TO BE OBSERVED BY 10Z AT MOST TAF SITES. CONDITIONS
SHOULD BECOME VFR BY 15Z TUESDAY. /22/
&&
.PREV DISCUSSION... /ISSUED 1000 AM CDT MON MAR 23 2015/
UPDATE...LATEST MODELS INDICATE CLEARING OVER THE SOUTHEAST HALF OF
THE REGION TODAY MAY BE A BIT SLOWER THAN PREVIOUSLY
ANTICIPATED...WITH POTENTIAL THAT SOME OF THE LOW CLOUDS IN PORTIONS
OF EAST/SE MS MAY HANG ON THROUGH THE AFTERNOON. MOST OF THE DRIZZLE
IS DONE...BUT HRRR SUGGESTS AT LEAST SOME ISOLATED SPRINKLES
UNDERNEATH THE MOST DOGGED CLOUDS CANNOT BE RULED OUT THROUGH THE
DAY AND THE FORECAST WAS UPDATED TO REFLECT THIS. CONSIDERING THE
MORE PERSISTENT CLOUDS THE HIGH TEMP FORECAST FOR THIS AFTERNOON IN
THE SOUTHEAST HALF OF THE CWA WAS LOWERED BY 2 TO 3 DEGREES IN MOST
CASES. /BB/
PREV DISCUSSION... /ISSUED 435 AM CDT MON MAR 23 2015/
DISCUSSION...TODAY THROUGH TUESDAY NIGHT...
A WEAK TROWAL ASSOCIATED WITH CYCLONIC FLOW ON THE BACK SIDE OF THE
DEPARTING LOW PRESSURE SYSTEM IS RESULTING IN CONTINUED -DZ/RA EARLY
THIS MORNING WITH MEASURABLE PRECIP STILL BEING REPORTED AT
JAN/HKS...BUT GUIDANCE INDICATES THIS SYSTEM WILL BE PROGRESSIVE...
AND EXPECT DRIZZLE TO END BY MID MORNING OVER ERN MS. WEAK LOW LEVEL
COLD ADVECTION WILL SUPPORT STRATUS DEVELOPMENT THROUGH THE MORNING
AND PERHAPS INTO THE AFTERNOON OVER CENTRAL/ERN MS...BUT WITH
SURFACE HIGH PRESSURE BUILDING OVER THE ARKLAMISS SKIES SHOULD CLEAR
AT MOST PLACES AS WE GO THROUGH LATE AFTERNOON AND INTO THE EVENING.
DEPENDING ON HOW MUCH INSOLATION/EVAPORATION TAKE PLACE TODAY...
CLEARING COULD SET THE STAGE FOR CONSIDERABLE FOG DEVELOPMENT AS LOW
TEMPERATURES POSSIBLY EXCEED CROSS-OVER TEMPS BY SEVERAL DEGREES.
LOW STRATUS/FOG COULD LINGER WELL INTO TUESDAY MORNING BEFORE MIXING
OUT BY AFTERNOON IN A DEVELOPING WARM ADVECTION PATTERN. CONTINUED
LOW LEVEL WARM ADVECTION MAY BRING MORE STRATUS/FOG POTENTIAL
TUESDAY NIGHT. /EC/
LONG TERM...WEDNESDAY THROUGH SUNDAY - GULF MOISTURE WILL BE SLOW TO
RETURN AHEAD OF AN APPROACHING STRONG COLD FRONT MOVING THROUGH THE
OZARKS BY WEDNESDAY EVENING. THERE WILL BE JUST ENOUGH WEAK MOISTURE
TRANSPORT TO PRODUCE SOME LIGHT SHOWERS ACROSS THE SOUTH DURING
WEDNESDAY AFTERNOON. FOR LATE WEDNESDAY NIGHT THERE WILL BE ENOUGH
MOISTURE CONVERGENCE AND INSTABILITY TO PRODUCE SOME CONVECTION
AHEAD OF THE COLD FRONT. THE STRONG COLD FRONT WITH THE ASSOCIATED
CONVECTION WILL PUSH ACROSS THE REGION ON THURSDAY. THIS WILL BE
ASSOCIATED WITH AN UNSEASONABLE UPPER TROUGH AND COOL PATTERN FOR
THURSDAY NIGHT THROUGH THE REST OF THE WEEK. THIS WAS AGREED UPON BY
THE CANADIAN...EURO/PARALLEL EURO...AND GFS OPERATIONAL MODELS AND
THEIR ENSEMBLES. HEIGHTS AND LOW LEVEL TEMPS WILL BE AROUND 3
STANDARD DEVIATIONS BELOW NORMAL. FOR THURSDAY EVENING THERE WILL BE
SOME POST FRONTAL SHOWERS ACROSS THE CWA WHICH WILL END BY FRIDAY.
OUR COOL PATTERN WILL BEGIN IN THE WAKE OF THE FRONT FOR THURSDAY
NIGHT WITH NEAR SEASONAL READINGS IN THE 40S. THE SHOWERS WILL END
BY FRIDAY WITH HIGHS IN THE 50S AND 60S...WHICH WILL BE 5 TO 15
DEGREES BELOW NORMAL. A STRONG UPPER TROUGH IN THE WAKE OF THE FRONT
WILL PUSH ACROSS THE ARKLAMISS ON FRIDAY INTO FRIDAY NIGHT. LOWS
WILL DIP INTO THE 30S AND 40S FOR FRIDAY NIGHT. IT WILL BE EVEN
COOLER SATURDAY WITH HIGHS JUST IN THE 50S. FOR SATURDAY NIGHT WE
WILL BE IN A GOOD SET UP FOR SOME STRONG RADIATIONAL COOLING AS
SURFACE HIGH PRESSURE SETTLES INTO THE REGION BEHIND THE DEPARTING
STRONG UPPER TROUGH. THERE COULD BE A RISK FOR SOME FREEZING TEMPS
IN THE LOWER 30S IN SOME AREAS. FOR NOW WILL KEEP LOWS ABOVE
FREEZING FOR SATURDAY NIGHT. SOME OF THE LOWER END OF THE ENSEMBLE
GUIDANCE KEEPS LOWS AROUND THE UPPER 20S TO FREEZING. RESIDENTS ARE
URGE TO KEEP UPDATED ON THE POTENTIAL COLDER TEMPS IN REGARDS TO
TENDER VEGETATION. THE CIPS MODELS JUST TO GIVEN AN IDEA OF THE
POTENTIAL...SLU CIPS ANALOG GUIDANCE CENTERED ON SATURDAY INDICATES
60-70% EXCEEDANCE OF THE <32F FOR 5 HR THRESHOLD OVER EAST CENTRAL
MS...AND > 50% EXCEEDANCE OF THE <32F FOR 1 HR THRESHOLD FOR MOST OF
THE FORECAST AREA. FOR NOW THIS FAR OUT WILL NOT MENTION THE
POTENTIAL IN THE HWO...BUT WILL MONITOR FOR LATER FORECAST
PACKAGES./17/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 49 75 55 79 / 2 3 11 15
MERIDIAN 47 74 54 79 / 2 3 7 16
VICKSBURG 48 77 54 79 / 2 2 6 14
HATTIESBURG 51 77 57 81 / 3 6 12 25
NATCHEZ 50 75 54 78 / 2 3 6 14
GREENVILLE 50 76 54 77 / 2 2 6 14
GREENWOOD 49 77 55 79 / 2 2 10 14
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
22/BB/17
AREA FORECAST DISCUSSION
NWS JACKSON MS
335 PM CDT MON MAR 23 2015
.UPDATE...THE SKIES HAVE CLEARED OVER MUCH OF THE CWA THIS EVENING
BUT SOME STRATUS WAS HANGING ON OVER THE SOUTHEAST ALONG INTERSTATE
59. THESE CLOUDS SHOULD SHIFT SOUTHEAST OF THE AREA BY MIDNIGHT.
UNDER CLEAR SKIES AND NEAR CALM WINDS GOOD RADIATIONAL COOLING
SHOULD ALLOW TEMPERATURES TO ACHIEVE FORECAST LOWS AND SOME PATCHY
DENSE FOG TO DEVELOP. ADJUSTED CLOUD COVER BUT NO OTHER CHANGES
NEEDED. /22/
&&
.AVIATION...STRATUS WAS STILL BEING OBSERVED ALONG THE I-59 CORRIDOR
BUT SHOULD SHOULD BE SE OF THE AREA BY 05Z. CLEAR SKIES WERE BEING
OBSERVED THIS EVENING ELSEWHERE. CLR SKIES AND NEAR CALM WIND WILL
ALLOW FOR FOG DEVELOPMENT AFTER MIDNIGHT. MVFR/IFR VISIBILITIES ARE
EXPECTED TO BE OBSERVED BY 10Z AT MOST TAF SITES. CONDITIONS
SHOULD BECOME VFR BY 15Z TUESDAY. /22/
&&
.PREV DISCUSSION... /ISSUED 1000 AM CDT MON MAR 23 2015/
UPDATE...LATEST MODELS INDICATE CLEARING OVER THE SOUTHEAST HALF OF
THE REGION TODAY MAY BE A BIT SLOWER THAN PREVIOUSLY
ANTICIPATED...WITH POTENTIAL THAT SOME OF THE LOW CLOUDS IN PORTIONS
OF EAST/SE MS MAY HANG ON THROUGH THE AFTERNOON. MOST OF THE DRIZZLE
IS DONE...BUT HRRR SUGGESTS AT LEAST SOME ISOLATED SPRINKLES
UNDERNEATH THE MOST DOGGED CLOUDS CANNOT BE RULED OUT THROUGH THE
DAY AND THE FORECAST WAS UPDATED TO REFLECT THIS. CONSIDERING THE
MORE PERSISTENT CLOUDS THE HIGH TEMP FORECAST FOR THIS AFTERNOON IN
THE SOUTHEAST HALF OF THE CWA WAS LOWERED BY 2 TO 3 DEGREES IN MOST
CASES. /BB/
PREV DISCUSSION... /ISSUED 435 AM CDT MON MAR 23 2015/
DISCUSSION...TODAY THROUGH TUESDAY NIGHT...
A WEAK TROWAL ASSOCIATED WITH CYCLONIC FLOW ON THE BACK SIDE OF THE
DEPARTING LOW PRESSURE SYSTEM IS RESULTING IN CONTINUED -DZ/RA EARLY
THIS MORNING WITH MEASURABLE PRECIP STILL BEING REPORTED AT
JAN/HKS...BUT GUIDANCE INDICATES THIS SYSTEM WILL BE PROGRESSIVE...
AND EXPECT DRIZZLE TO END BY MID MORNING OVER ERN MS. WEAK LOW LEVEL
COLD ADVECTION WILL SUPPORT STRATUS DEVELOPMENT THROUGH THE MORNING
AND PERHAPS INTO THE AFTERNOON OVER CENTRAL/ERN MS...BUT WITH
SURFACE HIGH PRESSURE BUILDING OVER THE ARKLAMISS SKIES SHOULD CLEAR
AT MOST PLACES AS WE GO THROUGH LATE AFTERNOON AND INTO THE EVENING.
DEPENDING ON HOW MUCH INSOLATION/EVAPORATION TAKE PLACE TODAY...
CLEARING COULD SET THE STAGE FOR CONSIDERABLE FOG DEVELOPMENT AS LOW
TEMPERATURES POSSIBLY EXCEED CROSS-OVER TEMPS BY SEVERAL DEGREES.
LOW STRATUS/FOG COULD LINGER WELL INTO TUESDAY MORNING BEFORE MIXING
OUT BY AFTERNOON IN A DEVELOPING WARM ADVECTION PATTERN. CONTINUED
LOW LEVEL WARM ADVECTION MAY BRING MORE STRATUS/FOG POTENTIAL
TUESDAY NIGHT. /EC/
LONG TERM...WEDNESDAY THROUGH SUNDAY - GULF MOISTURE WILL BE SLOW TO
RETURN AHEAD OF AN APPROACHING STRONG COLD FRONT MOVING THROUGH THE
OZARKS BY WEDNESDAY EVENING. THERE WILL BE JUST ENOUGH WEAK MOISTURE
TRANSPORT TO PRODUCE SOME LIGHT SHOWERS ACROSS THE SOUTH DURING
WEDNESDAY AFTERNOON. FOR LATE WEDNESDAY NIGHT THERE WILL BE ENOUGH
MOISTURE CONVERGENCE AND INSTABILITY TO PRODUCE SOME CONVECTION
AHEAD OF THE COLD FRONT. THE STRONG COLD FRONT WITH THE ASSOCIATED
CONVECTION WILL PUSH ACROSS THE REGION ON THURSDAY. THIS WILL BE
ASSOCIATED WITH AN UNSEASONABLE UPPER TROUGH AND COOL PATTERN FOR
THURSDAY NIGHT THROUGH THE REST OF THE WEEK. THIS WAS AGREED UPON BY
THE CANADIAN...EURO/PARALLEL EURO...AND GFS OPERATIONAL MODELS AND
THEIR ENSEMBLES. HEIGHTS AND LOW LEVEL TEMPS WILL BE AROUND 3
STANDARD DEVIATIONS BELOW NORMAL. FOR THURSDAY EVENING THERE WILL BE
SOME POST FRONTAL SHOWERS ACROSS THE CWA WHICH WILL END BY FRIDAY.
OUR COOL PATTERN WILL BEGIN IN THE WAKE OF THE FRONT FOR THURSDAY
NIGHT WITH NEAR SEASONAL READINGS IN THE 40S. THE SHOWERS WILL END
BY FRIDAY WITH HIGHS IN THE 50S AND 60S...WHICH WILL BE 5 TO 15
DEGREES BELOW NORMAL. A STRONG UPPER TROUGH IN THE WAKE OF THE FRONT
WILL PUSH ACROSS THE ARKLAMISS ON FRIDAY INTO FRIDAY NIGHT. LOWS
WILL DIP INTO THE 30S AND 40S FOR FRIDAY NIGHT. IT WILL BE EVEN
COOLER SATURDAY WITH HIGHS JUST IN THE 50S. FOR SATURDAY NIGHT WE
WILL BE IN A GOOD SET UP FOR SOME STRONG RADIATIONAL COOLING AS
SURFACE HIGH PRESSURE SETTLES INTO THE REGION BEHIND THE DEPARTING
STRONG UPPER TROUGH. THERE COULD BE A RISK FOR SOME FREEZING TEMPS
IN THE LOWER 30S IN SOME AREAS. FOR NOW WILL KEEP LOWS ABOVE
FREEZING FOR SATURDAY NIGHT. SOME OF THE LOWER END OF THE ENSEMBLE
GUIDANCE KEEPS LOWS AROUND THE UPPER 20S TO FREEZING. RESIDENTS ARE
URGE TO KEEP UPDATED ON THE POTENTIAL COLDER TEMPS IN REGARDS TO
TENDER VEGETATION. THE CIPS MODELS JUST TO GIVEN AN IDEA OF THE
POTENTIAL...SLU CIPS ANALOG GUIDANCE CENTERED ON SATURDAY INDICATES
60-70% EXCEEDANCE OF THE <32F FOR 5 HR THRESHOLD OVER EAST CENTRAL
MS...AND > 50% EXCEEDANCE OF THE <32F FOR 1 HR THRESHOLD FOR MOST OF
THE FORECAST AREA. FOR NOW THIS FAR OUT WILL NOT MENTION THE
POTENTIAL IN THE HWO...BUT WILL MONITOR FOR LATER FORECAST
PACKAGES./17/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 49 75 55 79 / 2 3 11 15
MERIDIAN 47 74 54 79 / 2 3 7 16
VICKSBURG 48 77 54 79 / 2 2 6 14
HATTIESBURG 51 77 57 81 / 3 6 12 25
NATCHEZ 50 75 54 78 / 2 3 6 14
GREENVILLE 50 76 54 77 / 2 2 6 14
GREENWOOD 49 77 55 79 / 2 2 10 14
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
22/BB/17
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1120 PM MDT SAT MAR 21 2015
.AVIATION...
06Z TAF CYCLE
CLEARING SKIES AND LIGHT WINDS MAY FAVOR SHALLOW FOG IN NORTHERN
AND WESTERN VALLEYS BY SUNRISE. THE AREA AROUND KROW MAY ALSO FAVOR
SOME FOG HOWEVER CONFIDENCE TOO LOW TO INCLUDE WITHIN THE PREVAILING
FORECAST. OTHERWISE...VFR ALL AREAS THROUGH SUNDAY WITH A FEW LATE
AFTERNOON BREEZES ALONG THE AZ BORDER AND EASTERN SLOPES.
GUYER
&&
.PREV DISCUSSION...541 PM MDT SAT MAR 21 2015...
.UPDATE...
INTERESTINGLY...THOUGH IT IS QUITE DIFFICULT TO GET SE BOUND
CONVECTION TO MAKE IT INTO THE ABQ METRO EVEN IN THE SUMMER...HERE
IT IS SURVIVING INTO THE NORTH PORTION OF THE METRO. IT SHOULD NOT
LAST MORE THAN ANOTHER HALF HOUR TO HOUR AND AMOUNTS WILL BE UNDER
A TENTH OF AN INCH...BUT FELT IT WAS ENOUGH TO NECESSITATE A QUICK
UPDATE. SO...IT IS THUS. ALSO TWEAKED POPS AND SKY COVER SLIGHTLY
IN A FEW OTHER SPOTS. 43
&&
.PREV DISCUSSION...310 PM MDT SAT MAR 21 2015...
.SYNOPSIS...
DRYING AND WARMING TREND SUNDAY AND MONDAY WITH SOME AFTERNOON
WINDINESS MONDAY. CRITICAL FIRE WEATHER CONDITIONS COULD DEVELOP
MONDAY AFTERNOON FROM THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN
OVER THE NORTHEAST AND EAST CENTRAL PLAINS. SOMEWHAT COOLER
TUESDAY...ALTHOUGH HIGH TEMPERATURES WILL REMAIN ABOVE AVERAGE.
THERE IS POTENTIAL FOR A BRIEF PERIOD OF WETTER WEATHER AROUND THE
MIDDLE OF NEXT WEEK...BUT FORECAST MODELS DIFFER CONSIDERABLY. A
DRYING TREND LOOKS TO RETURN FOR NEXT FRIDAY AND SATURDAY.
&&
.DISCUSSION...
PUNY CONVECTION OVER SOME OF THE NORTHERN...WESTERN AND CENTRAL
HIGH TERRAIN THIS AFTERNOON. KEPT THE SMALL INHERITED POPS FOR THIS
EVENING WITH LITTLE CHANGE...ALTHOUGH BOTH HRRR AND NAM12 MAKE A
CASE FOR ISOLATED CELLS THIS EVENING OVER THE FAR NORTHEAST. GIVEN
THERE/S NOT MUCH GOING ON OVER THE MTS ON THE COLORADO SIDE OF THE
BORDER AT THE MOMENT...THERE/S PROBABLY NOT MUCH CHANCE FOR ONE TO
SCORE A DIRECT HIT ON ANY RAINFALL MEASURING BUCKET.
OTHERWISE...THERE IS POTENTIAL FOR AT LEAST PATCHY FOG IN THE PECOS
VALLEY SOUTH OF INTERSTATE 40 EASTWARD TO THE TEXAS BORDER LATER
TONIGHT AND EARLY SUNDAY...INCLUDING THE CLOVIS/PORTALES
AREA...WHERE 40S DEWPOINTS FORECAST TO REMAIN IN PLACE AND THE MID
TO HIGH LEVEL MOISTURE CLEARS OUT WITH THE DEPARTING LOW/TROUGH.
DEW POINTS DRY OUT SUNDAY AS AN WEAK RIDGE BUILDS OVER THE STATE. A
SFC LEE TROUGH WILL BE ESTABLISHED...AND TEMPERATURES WILL RANGE
FROM AROUND 5 TO NEARLY 20 DEGREES ABOVE AVERAGE...WITH THE GREATEST
DEVIATION FROM NORMAL ACROSS NORTH CENTRAL AND NORTHEAST.
A TREND TOWARD ZONAL FLOW MONDAY...AND COMBINED WITH THE SFC
TROUGH...BREEZY TO WINDY CONDITIONS LOOK TO DEVELOP ESPECIALLY FROM
THE CENTRAL MT CHAIN OVER THE NORTHEAST AND EAST CENTRAL PLAINS.
WIDESPREAD WIND ADVY CRITERIA DOESN/T APPEAR TO BE
LIKELY...HOWEVER...IMPACTS WILL BE FIRE WEATHER RELATED AS HIGHS
WILL SOAR IN TO THE UPPER 70S AND 80S MONDAY AFTERNOON OVER THAT
PART OF THE FORECAST AREA. HIGH TEMPERATURE DEVIATIONS FROM AVERAGE
WILL BE SOMEWHAT SIMILAR TO THOSE OF SUNDAY.
TUESDAY WILL BE SLIGHTLY COOLER AS THE SFC TROUGH AND ASSOCIATED
SHORT WAVE TRACK NORTHEAST OF NEW MEXICO...LEAVING SOME GUSTY
NORTHWEST WINDS TO AFFECT THE CENTRAL MT CHAIN AND ADJACENT
HIGHLANDS.
FOR THE MID TO LATE WEEK PERIOD...THE ECMWF REMAINS THE WETTER
MODEL...COMPARED TO THE GFS...WHICH DEVELOPS 2 SEPARATE FEATURES...A
CUTOFF LOW OVER SOCAL...AND A SHORT WAVE IN THE NW FLOW ALOFT WHICH
CLIPS NORTHEAST NM. GIVEN THE DIFFERENCES...REINED IN POPULATED POPS
FOR WED NIGHT/THURS. FRIDAY AND SATURDAY LOOK DRY...BUT ECMWF DROPS
ANOTHER SHORT WAVE INTO NORTHERN NEW MEXICO SUNDAY...WHILE THE GFS
BOOTS OUT THE SOCAL LOW FARTHER NORTH AND OVER THE STATE. EITHER
WAY...IT LOOKS LIKE SPOTTY PRECIPITATION COULD DEVELOP.
&&
.FIRE WEATHER...
...CRITICAL FIRE WEATHER CONDITIONS POSSIBLE ON MONDAY ACROSS MUCH
OF EASTERN NEW MEXICO...
LOW PRESSURE SYSTEM ALOFT CONTINUES TO SWING SOUTH OF NM TODAY WITH
SOME STEADY BATCHES OF LIGHT PRECIPITATION FAVORING THE SOUTHERN
TIER OF THE STATE...MOSTLY OUT OF THE ABQ FIRE WEATHER FORECAST
AREA. HOWEVER...SOME REMNANT INSTABILITY AND MOISTURE IS LEADING TO
DEVELOPMENT OF NEW SHOWERS AND STORMS OVER THE HIGHER TERRAIN OF
CENTRAL NM THIS AFTERNOON. THIS ACTIVITY SHOULD REMAIN FAIRLY
ISOLATED WITH LOW PROBABILITIES FOR ACTUAL WETTING RAINFALL...BUT A
FEW CLOUD TO GROUND LIGHTNING STRIKES COULD OCCUR. DRIER AIR IN THE
MID TO UPPER LEVELS OF THE ATMOSPHERE IS SLOWLY FILTERING INTO THE
STATE FROM THE NORTH NORTHWEST...AND THIS TREND WILL PERSIST
OVERNIGHT. HOWEVER...THE DEWPOINTS NEAR THE SURFACE WILL BE SLOWER
TO RESPOND TO THIS DRYING...THUS ANOTHER NIGHT/MORNING OF EXCELLENT
RH RECOVERY IS ANTICIPATED THROUGH EARLY SUNDAY.
THE REMNANTS OF THE LOW PRESSURE SYSTEM WILL HAVE FULLY EXITED EAST
OF NM ON SUNDAY...GIVING WAY TO A RIDGE OF HIGH PRESSURE. THIS WILL
KEEP THE DRYING TREND GOING...WITH LOW LAYER RH/DEWPOINTS ALSO
QUICKLY RESPONDING DOWNWARD AS DEEP MIXING ENSUES IN AN ABOVE NORMAL
TEMPERATURE REGIME. PRECIPITATION WILL HAVE FULLY ESCAPED AND THE
ENTIRE FORECAST AREA SHOULD EXCEED SEASONAL AVERAGES. A WEAK LEE
SIDE SURFACE TROUGH WILL STRUGGLE TO TAKE SHAPE...BUT WILL NOT FULLY
COME TOGETHER BEFORE DUSK SUNDAY.
THE PATTERN TURNS MORE CRITICAL ON MONDAY AS THE RIDGE ALOFT BREAKS
DOWN AND STRONGER WESTERLY FLOW ALOFT DEVELOPS OVER NM WITH AVERAGE
SPEEDS OF 30-40 MPH IN THE 10000 TO 18000 FT LAYER. THIS WILL BE A
NOTABLE STRENGTHENING OF THESE UPPER LEVEL WINDS THAT HAS YET TO
TRANSFER TO THE SURFACE THUS FAR THIS YEAR. AS THE LEE SIDE SURFACE
CYCLONE BECOMES BETTER ESTABLISHED EXCELLENT MIXING IS
FORECAST...AND BREEZY TO WINDY CONDITIONS WILL ENSUE MONDAY
AFTERNOON WHILE THE WARMER THAN AVERAGE AND DRY CONDITIONS PERSIST.
WIND SPEEDS LOOK TO EXCEED CRITICAL SPEEDS OVER MUCH OF THE
NORTHEASTERN QUADRANT OF NM WHERE RH WILL PLUMMET TO 10 TO 15
PERCENT MONDAY AFTERNOON...AND AFTER FURTHER COLLABORATION ON THE
STATUS OF THE FINE OR 1-HOUR FUELS...BELIEVE THERE WILL BE ENOUGH
FIRE DANGER JUXTAPOSED WITH THE CRITICAL WINDS/RH. THUS...A WATCH
WILL BE HOISTED WITH THIS FORECAST PACKAGE.
A SHORT WAVE TROUGH WILL PASS NORTH OF NM MONDAY NIGHT...KEEPING
WINDS ALOFT STRONG...AND SOME MOUNTAIN WAVE ACTIVITY MAY EVEN CRASH
EAST OF THE SANGRE DE CRISTOS INTO EARLY TUESDAY MORNING. THE
REMAINDER OF TUESDAY SHOULD SEE A DECREASE IN SPEEDS ALOFT WITH
SLIGHTLY COOLER...BUT STILL ABOVE AVERAGE TEMPERATURES PREVAILING.
THE NEXT NOTABLE FEATURE WILL APPROACH ON THURSDAY AS A TROUGH DIVES
SOUTHEAST OUT OF CANADA AND ADDITIONAL ENERGY SEPARATES AND CUTS OFF
ON A TRAJECTORY NEAR OR WEST OF NM. FORECAST MODELS ARE HAVING
DIFFICULTY RETAINING CONTINUITY BETWEEN RUNS AND AMONGST EACH OTHER.
THE IMPACTS FROM THE COLDER AIR AND PRECIPITATION SEEM LESS CERTAIN
ACCORDING TO THE GFS...WHILE THE EUROPEAN MODEL IS MORE ASSERTIVE
WITH BOTH. 52
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR
THE FOLLOWING ZONES...NMZ103-104-107-108.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
421 AM EDT SUN MAR 22 2015
.SYNOPSIS...
COLD AIR WILL CONTINUE TO POUR INTO THE REGION TODAY WITH SOME LAKE
EFFECT SNOW SOUTH OF LAKE ONTARIO. HIGH PRESSURE WILL THEN BUILD
ACROSS THE LOWER GREAT LAKES TONIGHT THROUGH TUESDAY. WHILE COLD
WEATHER WILL ACCOMPANY THE AREA OF HIGH PRESSURE...SIGNIFICANT
WARMING CAN BE EXPECTED BY MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 400 AM...SYRACUSE/BINGHAMTON RADAR LOOPS SHOW LAKE ENHANCED SNOW
SHOWERS OF SOUTHEAST OF LAKE ONTARIO GENERALLY FOCUSED ON EASTERN
WAYNE COUNTY. SURFACE OBS SHOW A CONVERGENCE BOUNDARY FOCUSED IN THE
SAME LOCATION BETWEEN ROCHESTER AND FULTON. UNLIKE TYPICAL LAKE
EFFECT EVENTS WHERE THESE BOUNDARIES ARE LAKE DRIVEN...THIS IS
PRIMARILY A SYNOPTIC BOUNDARY ON THE SOUTHERN FRINGE OF AN UPPER
LEVEL TROUGH. MOST HIGH RESOLUTION MODEL GUIDANCE CAPTURES THIS
BOUNDARY WELL. CURIOUSLY MUCH OF THE 00Z HIGH RES GUIDANCE HAS
SHIFTED QPF TO THE NORTHEAST OF THE BOUNDARY WHICH DOES NOT MATCH
THE LATEST CONDITIONS. FORECAST WILL FOCUS ON THE BOUNDARY WHICH IS
WELL DEPICTED BY THE HRRR AND SUPPORTED BY SURFACE WINDS OF MOST
OTHER HIGH RES GUIDANCE. THERE IS LITTLE DOUBT THAT THE BOUNDARY
WILL DROP SOUTHWARD MID-MORNING WHICH WILL PUSH STEADIER LAKE EFFECT
SNOW ACROSS MONROE AND ONTARIO COUNTIES BY DAYBREAK. SNOW WILL BE
SHORT-LIVED AS THE BOUNDARY CONTINUES ITS SOUTHWARD PUSH WITH SNOW
LIKELY TO FALL APART AS THE BOUNDARY GETS FURTHER FROM THE MOISTURE
OF LAKE ONTARIO. STEADIEST BANDS SHOULD BRING 3 TO 5 INCHES TO SOME
LOCATIONS IN WAYNE COUNTY...WITH AMOUNTS DROPPING OFF DOWN TO ONLY
AN INCH OR TWO IN THE ROCHESTER METRO AREA...AND EVEN LESS TO THE
WEST.
DAYTIME MIXING SHOULD FURTHER DISRUPT THE LAKE EFFECT BY EARLY
AFTERNOON WHEN ACCUMULATING SNOW SHOULD BE DONE. THE AIRMASS IS
PROBABLY DRY ENOUGH FOR SOME SUNSHINE UNTIL AFTERNOON CU DEVELOP
SOUTH OF THE LAKE. TEMPERATURES WILL BE ON THE COOL SIDE...WITH
HIGHS IN THE MID TO UPPER 20S IN MOST LOCATIONS...WITH SOME AREAS
EAST OF LAKE ONTARIO STRUGGLING TO REACH 20.
A WEAK SHORTWAVE WILL CLIP THE NORTH COUNTRY LATE THIS AFTERNOON AND
EVENING WHICH MAY SPARK A FLURRY OR LIGHT SNOW SHOWERS. THIS ALSO
MAY BRIEFLY ENHANCE LAKE EFFECT SNOW EAST AND SOUTHEAST OF LAKE
ONTARIO...WITH VERY LIGHT ACCUMULATIONS POSSIBLE. ELSEWHERE...FAIR
BUT CHILLY CONDITIONS WITH OVERNIGHT LOWS 5 TO 15 ABOVE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
HIGH PRESSURE DROPPING SOUTHWARD FROM THE UPPER GREAT LAKES WILL
PRESENT DRY WEATHER CONDITIONS ACROSS OUR REGION FOR MONDAY THROUGH
TUESDAY. ACCOMPANYING THIS AREA OF HIGH PRESSURE WILL BE A DRY
AIRMASS...ONE THAT WILL BRING LOW DEW POINTS IN THE SINGLE DIGITS.
CLOUDS WILL THICKEN SOME OVER OUR EASTERN AREAS MONDAY NIGHT AS THE
TAIL END OF AN UPPER LEVEL TROUGH CLIPS THE REGION. THIS AREA OF
HIGH PRESSURE WILL SLIDE ACROSS THE REGION ON TUESDAY WITH ABUNDANT
SUNSHINE.
HIGHS ON MONDAY WILL REMAIN IN THE 20S...ABOUT 20 DEGREES BELOW
NORMAL...WHILE ON TUESDAY UNDER SLIGHTLY WARMER TEMPERATURES ALOFT
WE SHOULD CLIMB INTO THE 30S ACROSS THE REGION.
TUESDAY NIGHT THIS AREA OF HIGH PRESSURE WILL SLIDE OFF THE EAST
COAST...WITH A RETURN SOUTHERLY FLOW BRINGING BOTH A MILDER AND
MOISTER AIRMASS. AS A WARM FRONT NEARS THE REGION FROM THE OHIO
VALLEY A RAIN OR LOWER CHANCE...WET SNOW SHOWER IS POSSIBLE JUST
BEFORE DAYBREAK WEDNESDAY MORNING. UNDER THIS SOUTHERLY FLOW
OVERNIGHT LOWS TUESDAY NIGHT WILL RANGE FROM AROUND 20 EAST OF LAKE
ONTARIO...TO UPPER 20S EAST OF LAKE ERIE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A STORM SYSTEM FROM THE UPPER GREAT LAKES WILL REACH OUR AREA TO
START THE TIME PERIOD. THIS SYSTEM ACCOMPANIED BY A SHARP SHORTWAVE
IS PROGGED TO LIFT NORTHEASTWARD FROM THE NORTHERN PLAINS TUESDAY TO
ACROSS THE UPPER GREAT LAKES ON WEDNESDAY. A WARM FRONT WILL LIFT NORTHWARD
ACROSS THE AREA ON WEDNESDAY...ALLOWING TEMPERATURES TO SURGE INTO
THE LOW TO MID 50S FOR MOST OF THE AREA BY THE AFTERNOON. EXPECT TO
SEE A SHIELD OF PRECIPITATION IN THE FORM OF RAIN LIFT NORTHWARD
ACROSS THE AREA WEDNESDAY MORNING ALONG THE FRONT...BUT THEN WE
COULD SEE THE PRECIPITATION WEAKEN/BECOME MORE SHOWERY BY WEDNESDAY
AFTERNOON AS WE GET INTO THE WARM SECTOR AND THE SYNOPTIC FORCING
MOVES INTO SOUTHERN ONTARIO.
MODELS DIVERGE SLIGHTLY BY WEDNESDAY NIGHT INTO THURSDAY ON WHERE AN
ELONGATED BAROCLINIC ZONE WILL SET UP. 12Z ECMWF PLACES THIS
BOUNDARY SLIGHTLY FARTHER EAST THAN THE 12Z GFS SOLUTION. THE ECMWF
SOLUTION WOULD MEAN MUCH LESS RAINFALL FOR WESTERN NY...BEING
STUCK ON THE COLD SIDE OF THE BOUNDARY. THE GFS SOLUTION PRODUCES
MUCH MORE RAINFALL FOR THE FORECAST AREA WITH A MORE FAVORABLE
ORIENTATION OF THE BAROCLINIC ZONE JUST TO OUR WEST. THE POTENTIAL
FOR WARMER WEATHER AND POTENTIALLY SIGNIFICANT RAINFALL STILLS BARES
WATCHING FOR POSSIBLE HYDROLOGIC ISSUES STILL.
BEHIND THIS WEATHER SYSTEM...THE WEEK WILL END WITH BELOW NORMAL
TEMPERATURES AND THE POTENTIAL FOR SOME LAKE EFFECT SNOW SHOWERS
SOUTHEAST OF LAKE ONTARIO AS A BROAD TROUGH CROSSES OVERHEAD.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
A DEVELOPING LAKE EFFECT BAND SE OF LAKE ONTARIO WILL DROP SOUTHWARD
AND PROBABLY BRING A COUPLE HOURS OF STEADY SNOW TO THE ROCHESTER
TERMINAL WITH IFR OR LOWER CONDITIONS. THIS MAY CLIP BUF/IAG/JHW
WITH SOME LIGHT SNOW AND MVFR CLOUD DECKS AS A CONVERGENCE BOUNDARY
CONTINUES TO DROP SOUTH THROUGH MID-MORNING. OTHERWISE...EXPECT VFR
CONDITIONS.
HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE LOWER LAKES THIS
AFTERNOON WITH MOSTLY VFR CONDITIONS THROUGH TONIGHT. A WEAK UPPER
LEVEL DISTURBANCE IS FORECAST TO CLIP THE NORTH COUNTRY...WHICH MAY
LOWER CIGS AND BRING A BRIEF SNOW SHOWER TO ART/ROC TONIGHT.
OUTLOOK...
MONDAY AND TUESDAY...VFR.
WEDNESDAY...DETERIORATING CONDITIONS IN RAIN...WHICH MAY BEGIN AS A
LITTLE WET SNOW.
THURSDAY...MVFR IN RAIN SHOWERS.
&&
.MARINE...
BRISK NORTHWESTERLY WINDS WILL PERSIST THROUGH AT LEAST THIS
EVENING AS A RELATIVELY TIGHT SFC PRESSURE GRADIENT WILL REMAIN
IN PLACE. THIS WILL RESULT IN A PROLONGED PERIOD OF ADVISORY-
WORTHY WINDS AND WAVES FOR THE ICE FREE WATERS OF THE WESTERN TWO
THIRDS OF LAKE ONTARIO. BASED ON THE LATEST GUIDANCE HAVE EXTENDED
THE SMALL CRAFT ADVISORIES INTO MONDAY MORNING. AFTER THIS..HIGH
PRESSURE WILL BUILD ACROSS THE WATERS WITH QUIET CONDITIONS EXPECTED
THROUGH MID-WEEK.
&&
.HYDROLOGY...
MODEL GUIDANCE CONTINUES TO SUGGEST THAT THERE WILL BE A WARM UP
MID-WEEK. HOW LONG THIS LASTS...AND HOW MUCH RAIN COMES WITH THIS
WARM UP IS STILL UNCERTAIN. MMEFS ENSEMBLE GUIDANCE SUGGESTS AN
INCREASING PROBABLY (AROUND 30 PERCENT) FOR FLOODING ON SOME OF
THE BUFFALO CREEKS AND IN THE GENESEE AND ALLEGHENY BASINS. THIS
DOES NOT TAKE INTO ACCOUNT THAT THERE ARE ICE JAMS IN PLACE ON
SOME OF THE CREEKS WHICH COULD RESULT IN ICE JAM FLOODING IF FLOWS
INCREASE RAPIDLY. IF THERE IS FLOOD IT PROBABLY WOULD NOT OCCUR
UNTIL AT LEAST WEDNESDAY WHEN TEMPERATURES ARE FORECAST TO WARM
INTO THE 40S AND 50S. HYDROLOGIC CONDITIONS ARE DISCUSSED IN THE
ESF PRODUCT...AND THE RISK FOR FLOODING MID TO LATE WEEK IS
DISCUSSED IN THE HAZARDOUS WEATHER OUTLOOK (HWO). IF THERE IS
GOING TO BE FLOODING DUE TO SNOW MELT THIS SPRING...THIS WILL
PROBABLY HAVE TO BE THE SYSTEM TO DO IT FOR THE BUFFALO
CREEKS...GENESEE...AND ALLEGHENY BASINS. IF FORECAST CONFIDENCE
INCREASES IT IS POSSIBLE THAT FLOOD WATCHES WILL BE NEEDED FOR
SOME AREAS IN THE WEDNESDAY AND THURSDAY TIMEFRAME.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
NYZ003-004-014.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR LOZ042-043.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...THOMAS
LONG TERM...CHURCH/THOMAS
AVIATION...APFFEL
MARINE...APFFEL
HYDROLOGY...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
305 AM EDT SUN MAR 22 2015
.SYNOPSIS...
IN THE WAKE OF A COLD FRONT...MUCH COLDER AIR WILL CONTINUE TO POUR
ACROSS OUR AREA OVERNIGHT...WHILE GENERATING SOME ACCUMULATING LAKE
SNOWS SOUTH OF LAKE ONTARIO BETWEEN LATE TONIGHT AND SUNDAY
MORNING. HIGH PRESSURE WILL THEN BUILD ACROSS THE LOWER GREAT
LAKES SUNDAY AND MONDAY. WHILE COLD WEATHER WILL ACCOMPANY THE
AREA OF HIGH PRESSURE...SIGNIFICANT WARMING CAN BE EXPECTED BY MID
WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AT 300 AM...RADAR/SATELLITE LAKE ENHANCED SNOW SHOWERS SOUTHEAST
OF LAKE ONTARIO. SURFACE OBS SHOW A CONVERGENCE BOUNDARY FOCUSED
IN THE SAME LOCATION...SOMEWHERE BETWEEN ROCHESTER AND FULTON.
UNLIKE TYPICAL LAKE EFFECT EVENTS WHERE THESE BOUNDARIES ARE
TYPICALLY LAKE DRIVEN...THIS IS A SYNOPTIC BOUNDARY ON THE
SOUTHERN FRINGE OF AN UPPER LEVEL TROUGH. HIGH RESOLUTION MODEL
GUIDANCE CAPTURES THIS BOUNDARY WELL WITH THE HOURLY HRRR GRIDS
PROVIDING A GOOD PICTURE OF THE LIKELY PROGRESSION OF THE
BOUNDARY. HOWEVER...THE 00Z NAM APPEARS TO BE TOO FAR NORTHEAST
WITH THE QPF...WITH STEADIEST SNOWS LIKELY TO BE FOCUSED ALONG THE
BOUNDARY. AT ANY RATE...THERE IS LITTLE DOUBT THAT THE BOUNDARY
WILL DROP SOUTHWARD MID-MORNING. THIS WILL PUSH STEADIER LAKE
EFFECT SNOW WESTWARD INTO AND ACROSS MONROE AND ONTARIO COUNTIES
BY DAYBREAK. SNOW WILL BE SHORT-LIVED AS THE BOUNDARY CONTINUES
ITS SOUTHWARD PUSH. THIS WILL RESULT IN LOWER AMOUNTS WHERE THINGS
GET OFF TO A LATER START. STEADIEST BANDS SHOULD BRING 3 TO 5
INCHES TO SOME LOCATIONS IN WAYNE COUNTY...WITH AMOUNTS DROPPING
OFF DOWN TO ONLY AN INCH OR TWO IN THE ROCHESTER METRO AREA...AND
EVEN LESS TO THE WEST.
AFTER THIS BOUNDARY DROPS SOUTH AND WEAKENS LATE THIS
MORNING...EXPECT DAYTIME HEATING TO MIX IN DRIER AIR AND DISRUPT
MOST OF THIS ACTIVITY. THE AIRMASS IS PROBABLY DRY ENOUGH FOR SOME
SUNSHINE UNTIL AFTERNOON CU DEVELOP SOUTH OF THE LAKE. WEAK
SHORTWAVE WILL CLIP THE NORTH COUNTRY LATE THIS AFTERNOON WHICH
MAY SPARK A FLURRY OR BRIEF SNOW SHOWERS. TEMPERATURES WILL BE ON
THE COOL SIDE...WITH HIGHS IN THE MID TO UPPER 20S IN MOST
LOCATIONS...WITH SOME AREAS EAST OF LAKE ONTARIO STRUGGLING TO
REACH 20.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
MAINLY QUIET WEATHER EXPECTED IN THE SHORT TERM AS HIGH PRESSURE
BUILDS IN ACROSS THE AREA. MONDAY WILL REMAIN A COOL DAY AS LIGHT
NORTHERLY WINDS AHEAD OF THE SURFACE HIGH KEEP -12C 850 MB
TEMPERATURES LOCKED IN ACROSS WESTERN/CENTRAL NY. HIGH TEMPERATURES
ON MONDAY WILL BE STUCK IN THE 20S. LIGHT WINDS AND CLEAR SKIES
MONDAY NIGHT AS THE SURFACE HIGH SLIDES OVERHEAD WILL MAKE FOR A
COOL NIGHT WITH TEMPERATURES DIPPING INTO THE TEENS AND SINGLE
DIGITS. THE COLDEST TEMPERATURES WILL BE IN THE NORTH COUNTRY AND
THE HIGHER TERRAIN OF THE WESTERN SOUTHERN TIER. TUESDAY WILL START
A SLOW WARMING TREND TOWARD MID-WEEK...AS THE SURFACE HIGH SLIDES
EAST OF THE AREA AND THE SOUTHERLY RETURN FLOW RESUMES. 850 MB
TEMPERATURES RECOVER INTO THE -2 TO -6C RANGE BY TUESDAY
AFTERNOON...WHICH WILL PUSH SURFACE TEMPERATURES INTO THE 30S FOR
MOST LOCATIONS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE SYSTEM TO WATCH ENTERS THE PICTURE EARLY WEDNESDAY MORNING AS A
SHARP SHORTWAVE IS PROGGED TO LIFT NORTHEASTWARD ACROSS MICHIGAN. A
WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA ON
WEDNESDAY...ALLOWING TEMPERATURES TO SURGE INTO THE LOW TO MID 50S
FOR MOST OF THE AREA BY THE AFTERNOON. EXPECT TO SEE A SHIELD OF
PRECIPITATION IN THE FORM OF RAIN LIFT NORTHWARD ACROSS THE AREA
WEDNESDAY MORNING ALONG THE FRONT...BUT THEN WE COULD SEE THE
PRECIPITATION WEAKEN/BECOME MORE SHOWERY BY WEDNESDAY AFTERNOON AS
WE GET INTO THE WARM SECTOR AND THE SYNOPTIC FORCING MOVES INTO
SOUTHERN ONTARIO.
MODELS DIVERGE SLIGHTLY BY WEDNESDAY NIGHT INTO THURSDAY ON WHERE AN
ELONGATED BAROCLINIC ZONE WILL SET UP. 12Z ECMWF PLACES THIS
BOUNDARY SLIGHTLY FARTHER EAST THAN THE 12Z GFS SOLUTION. THE ECMWF
SOLUTION WOULD MEAN MUCH LESS RAINFALL FOR WESTERN NY...BEING
STUCK ON THE COLD SIDE OF THE BOUNDARY. THE GFS SOLUTION PRODUCES
MUCH MORE RAINFALL FOR THE FORECAST AREA WITH A MORE FAVORABLE
ORIENTATION OF THE BAROCLINIC ZONE JUST TO OUR WEST. THE POTENTIAL
FOR WARMER WEATHER AND POTENTIALLY SIGNIFICANT RAINFALL STILLS BARES
WATCHING FOR POSSIBLE HYDROLOGIC ISSUES STILL.
BEHIND THIS WEATHER SYSTEM...THE WEEK LOOKS TO CLOSE OUT WITH BELOW
NORMAL TEMPERATURES AND THE POTENTIAL FOR SOME LAKE EFFECT SNOW
SHOWERS SOUTHEAST OF LAKE ONTARIO AS A BROAD TROUGH CROSSES OVERHEAD.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
OUTSIDE OF LAKE EFFECT EXPECT VFR CONDITIONS THROUGH THIS
AFTERNOON. A DEVELOPING LAKE EFFECT BAND SE OF LAKE ONTARIO WILL
DROP SOUTHWARD AND PROBABLY BRING A COUPLE HOURS OF STEADY SNOW TO
THE ROCHESTER TERMINAL WITH IFR OR LOWER CONDITIONS. THIS MAY CLIP
BUF/IAG/JHW WITH SOME LIGHT SNOW AND MVFR CLOUD DECKS AS A
CONVERGENCE BOUNDARY DROPS SOUTH DURING SUNDAY MORNING.
HIGH PRESSURE BUILDS SOUTHEASTWARD ACROSS THE LOWER GREAT LAKES
ON SUNDAY...THE LAKE SNOWS SHOULD WEAKEN DRAMATICALLY AND SHIFT TO
AREAS SOUTHEAST OF LAKE ONTARIO...WHILE GENERAL VFR CONDITIONS
BECOME RE-ESTABLISHED ACROSS THE REGION. A WEAK UPPER LEVEL
DISTURBANCE IS FORECAST TO CLIP THE NORTH COUNTRY...WHICH MAY
LOWER CIGS AND BRING A BRIEF SNOW SHOWER TO ART SUNDAY EVENING.
OUTLOOK...
SUNDAY NIGHT...MAINLY VFR WITH A CHANCE OF SNOW SHOWERS EAST AND
SOUTHEAST OF LAKE ONTARIO.
MONDAY AND TUESDAY...VFR.
WEDNESDAY...DETERIORATING CONDITIONS IN RAIN...WHICH MAY BEGIN AS A
LITTLE WET SNOW.
THURSDAY...MVFR IN RAIN SHOWERS.
&&
.MARINE...
BRISK NORTHWESTERLY WINDS WILL PERSIST THROUGH AT LEAST THIS
EVENING AS A RELATIVELY TIGHT SFC PRESSURE GRADIENT WILL REMAIN
IN PLACE. THIS WILL RESULT IN A PROLONGED PERIOD OF ADVISORY-
WORTHY WINDS AND WAVES FOR THE ICE FREE WATERS OF THE WESTERN TWO
THIRDS OF LAKE ONTARIO...AS IS OUTLINED BELOW.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
NYZ003-004-014.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR LOZ042-043.
&&
$$
SYNOPSIS...JJR/RSH
NEAR TERM...APFFEL
SHORT TERM...CHURCH
LONG TERM...CHURCH
AVIATION...APFFEL
MARINE...JJR/RSH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
815 PM EDT MON MAR 23 2015
.SYNOPSIS...A COOLER AND DRIER AIRMASS ASSOCIATED WITH A HIGH
PRESSURE SYSTEM TO THE NORTH WILL CONTROL THE PATTERN FOR MIDWEEK
BEFORE MORE UNSETTLED WEATHER ASSOCIATED WITH A LOW PRESSURE SYSTEM
AND ASSOCIATED COLD FRONT MOVE IN LATE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM MONDAY...
MUCH DRIER AIRMASS TO THE NORTH HAS MOVED IN AND HELPED TO SCOUR OUT
CLOUD COVER OVER THE NORTHWESTERN HALF OF THE CWA AND AS A RESULT
HAVE CAUSED TEMPERATURES TO RISE CONSIDERABLY ESPECIALLY IN THE
SOUTHWEST WHERE LOW 60S ARE NOW IN PLAY. CLOUDS HAVE CONTINUED TO
HANG ON IN THE EAST WHERE TEMPERATURES REMAIN COOLEST...PARTICULARLY
ALONG THE NORTHERN I-95 CORRIDOR. THIS PATTERN SHOULD PERSIST FOR
THE REST OF THE DAY AND WILL EXPECT TO SEE HIGHS IN THE MID 50S
NORTHEAST TO LOW 60S SOUTHWEST.
DRIER WEATHER IS EXPECTED OVERNIGHT AS WELL AND THE CHANCE FOR SOME
LOW CLOUDS IS DWINDLING ALTHOUGH RELATIVE HUMIDITY CROSS SECTIONS
AND RAP MODEL FORECASTS ARE SHOWING MOISTURE MOVING THROUGH THE NW
PIEDMONT DURING THE EARLY MORNING HOURS WHICH COULD HELP TO FORM
SOME BRIEF MVFR CEILINGS BUT CONFIDENCE IN THIS HAPPENING IS VERY
LOW AT THIS TIME. THUS WILL LOWER TEMPS A BIT INTO THE MID TO UPPER
30S FOR LOWS.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 245 PM MONDAY...
SURFACE HIGH PRESSURE OVER THE NORTHEAST WILL TRY TO WEDGE INTO THE
CAROLINAS BUT THE HIGH IS NOT PARTICULARLY STRONG OR IN AN IDEAL
POSITION FOR DAMMING...A LITTLE TOO FAR WEST. A SECONDARY HIGH WILL
TRY TO FORM ALONG THE DELMARVA LATER IN THE DAY AND THIS COULD
PRESENT MORE OF AN IN SITU DAMMING SCENARIO ON TUESDAY NIGHT AS
ISENTROPIC LIFT INCREASES ON THE 290K SURFACE. FLOW ALOFT WILL BE
FAIRLY ZONAL. THEREFORE LIGHT RAIN CHANCES INCREASE LATER TUESDAY
NIGHT...BUT OTHERWISE EXPECT A MOSTLY DRY FORECAST WITH PARTLY
CLOUDY SKIES. HIGHS IN THE MID 50S NORTHEAST TO MID 60S SOUTHWEST.
WINDS WILL VARY ACROSS THE CWA WITH A MORE SOUTHEASTERLY COMPONENT
OVER THE TRIAD AND A MORE NORTHEASTERLY COMPONENT IN THE NORTHEAST.
THUS PARTIALLY EXPLAINING THE DIFFERENCE IN FORECAST HIGHS AT AROUND
5 KTS. WITH THE INCREASE IN CLOUD COVER...HAVE INCREASED LOWS
TUESDAY NIGHT INTO THE LOW TO MIDDLE 40S NORTHEAST TO SOUTHWEST.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
GRADUAL MOISTURE ADVECTION TAKES PLACE WEDNESDAY INTO WEDNESDAY
NIGHT...WITH PRECIPITABLE WATER VALUES INCREASING WELL ABOVE NORMAL
BY 06Z THURSDAY. BUFR SOUNDINGS FROM BOTH THE NAM AND THE GFS
WEDNESDAY SUGGEST A SHARP INVERSION THROUGH THE MORNING WEDNESDAY
WITH MAINLY DRY AIR ABOVE...SUGGESTIVE OF THE POTENTIAL FOR DRIZZLE
WEDNESDAY MORNING AND POSSIBLY A PATCH OF LIGHT RAIN MAINLY OVER THE
WESTERN PIEDMONT WHERE THE LOW-LEVEL MOISTURE IS FORECAST JUST A
LITTLE DEEPER COMPARED TO THE REST OF THE AREA. BOTH THE NAM AND THE
GFS SUGGEST SOME LOW-LEVEL MOISTURE EROSION...SLOWEST IN THE
NORTHWEST PIEDMONT...AND WHILE BOTH THE NAM AND GFS SUGGEST SOME
CAPPING TO MODESTLY DEEP CONVECTION WEDNESDAY AFTERNOON...THE CAP
DOES ERODE ENOUGH TOWARD THE YADKIN RIVER THAT POSSIBLY A SHOWER
COULD OCCUR THERE AGAIN LATE IN THE DAY. HIGH TEMPERATURES HAVE
TRENDED WARMER BUT STILL EXPECT THE SAME PATTERN OF HIGHS
APPROACHING 60 TOWARD THE TRIAD AND NOTICEABLY WARMER TOWARD KFAY
AND KCTZ...AROUND 70 TO THE LOWER 70S.
WEDNESDAY NIGHT THERE IS GOOD VORTICITY ADVECTION AT 700MB ALONG
WITH INCREASING DIFFLUENCE IN MOISTURE ADVECTION. THE TIMING OF
DEEPENING MOISTURE DIFFERS ON THE NAM AND GFS BUFR SOUNDINGS...BUT
THEY ARE SIMILAR ENOUGH TO SUGGEST A GOOD CHANCE OF SHOWERS
DEVELOPING WEST-TO-EAST WEDNESDAY NIGHT...AND THESE CHANCES COULD
END UP BEING LIKELY OR EVEN CATEGORICAL AT SOME POINT PRIOR TO THEN.
CAPE IS VERY SKINNY ON BUFR SOUNDINGS BUT NON-ZERO...AND IF THE MID-
LEVEL WAVE AND DIFFLUENCE REMAIN AS FORECAST A RUMBLE OF THUNDER
CANNOT BE RULED OUT BUT WILL LEAVE OUT OF THE FORECAST FOR NOW.
TEMPERATURES SHOULD FALL LITTLE IN THE TRIAD...OVERALL THROUGHOUT
CENTRAL NORTH CAROLINA LOWS 55 TO 60.
THE SHORTWAVE MOVES OFF TO THE EAST THURSDAY EARLY AND THERE IS
FORECAST BY THE GFS A PERIOD OF CONVERGENCE ALOFT BEFORE THE COLD
FRONT GETS CLOSER LATER IN THE DAY. THE TIMING OF THE FRONTAL
PASSAGE IS A LITTLE SLOWER...AND THIS COULD RESULT IN GOOD WARMING
WITH SOME BREAKS IN THE CLOUDS FOR THE LATE MORNING INTO THE
AFTERNOON. GFS BUFR SOUNDINGS...IN FACT...SHOW THE POTENTIAL FOR A
GOOD BIT OF SUN ALONG AND EAST OF U.S. 1 FOR A TIME WHICH COULD HELP
TO ELEVATE TEMPERATURES FROM NEAR 80 TO 85 THERE. FOR THIS FORECAST
WILL HAVE MID 70S IN THE NORTHWEST PIEDMONT AND NEAR 80 IN THE
TRIANGLE...WITH SOLID LOWER 80S IN THE SOUTHEAST ZONES IN A MODESTLY
GUSTY SOUTHWEST WIND. IF THE FRONTAL TIMING SLOWS EVEN A LITTLE MORE
MUCH OF THURSDAY AFTERNOON COULD BE DRY...BUT FOR THIS FORECAST WILL
RETAIN CHANCES FOR SHOWERS AND A THUNDERSTORM THEN...LOW CHANCES
TOWARD INTERSTATE 95 AND HIGHER CHANCES TOWARD THE TRIAD. THURSDAY
COULD BE A DAY WITH MORNING SHOWERS MOVING EAST FOLLOWED BY A DECENT
BREAK IN PRECIPITATION CHANCES...WITH RENEWED CHANCES LATER IN THE
DAY COMING IN FROM THE NORTHWEST. INSTABILITY IS MARGINAL ON THE GFS
INTO THURSDAY EVENING...MLCAPE THROUGH THE LOWEST 2KM LESS THAN
500J/KG...BUT THE 0-3KM SHEAR IS GOOD APPROACHING 60KT WITH THE
FRONT. THE NAM IS MORE UNSTABLE...BUT JET SUPPORT SEEMS TO BE
LAGGING.
THE COLD FRONT WILL BE MOVING PAST CENTRAL NORTH CAROLINA THURSDAY
NIGHT WITH CHANCES FOR SHOWERS...AND POSSIBLY A THUNDERSTORM IN THE
EVENING AS COARSE MODEL SOUNDINGS FROM THE GFS AND ECMWF SUGGEST
STEEP ENOUGH LAPSE RATES TO CONTINUE THE CHANCE OF THUNDER INTO THE
EVENING. THE CAPE IS SKINNY...AND THOSE COARSE SOUNDINGS BECOME
STABLE OVERNIGHT BUT WITH ENOUGH MOISTURE TO SUGGEST THE POTENTIAL
FOR LINGERING SHOWERS INTO FRIDAY MORNING. SOME OF THE LATEST
GUIDANCE IS A LITTLE SLOWER WITH THE TIMING OF THE FRONTAL PASSAGE
AND THE CANADIAN AND DGEX ARE VERY SLOW...WHICH WOULD CARRY CHANCES
FOR PRECIPITATION THROUGH THE DAY FRIDAY. UNLESS THE FRONTAL TIMING
CONTINUES TO SLOW...THE MOST LIKELY SOLUTION CURRENTLY IS LINGERING
MORNING SHOWERS MOSTLY ALONG AND EAST OF U.S. 1...BUT FOR THIS
FORECAST WILL NOTE A SLIGHT CHANCE OF SHOWERS IN THE NORTHWEST
PIEDMONT THROUGHOUT FRIDAY AND CHANCES MAINLY ALONG AND EAST OF U.S.
1 DUE TO UNCERTAINTY. AS THE UPPER TROUGH AXIS APPROACHES...
CONSIDERING THE SLOWEST SOLUTIONS THEN A LINGERING SHOWER COULD
CONTINUE IN THE EVENING MAINLY ALONG AND EAST OF INTERSTATE 95...
BUT IF THE LATEST GFS VERIFIES WITH K INDICES FALLING GREATLY...
CHANCES FOR PRECIPITATION WILL END EARLIER THAN FORECAST.
THE BIGGEST CHANGES FROM MODEL GUIDANCE OF SUNDAY IS OVERALL DRIER
FROM SATURDAY THROUGH THE WEEKEND. THE DEEP TROUGH AXIS MOVES
THROUGH THE EASTERN CONUS FRIDAY AND SATURDAY WITH SOME DIFFERENCES
IN THE DETAILS ON THE GFS AND THE ECMWF...BUT BOTH MODELS ARE DRIER
WITH REGARD TO THE MEAN MOISTURE AND WITH SURFACE LOW PRESSURE
FARTHER OFFSHORE. WHILE TEMPERATURES WILL BE BELOW NORMAL...QPF HAS
TRENDED TO VERY LIGHT OR NIL AND PLANNING NOW TO FEATURE A DRY
FORECAST FOR CENTRAL NORTH CAROLINA AFTER EARLY FRIDAY NIGHT.
THE SURFACE RIDGE AXIS SHOULD MOVE QUICKLY SOUTH BY SUNDAY...MAKING
FOR A RETURN TO A SOUTHWEST FLOW AND WARMER TEMPERATURES. SURFACE
RIDGING IS FORECAST ACROSS THE GULF...WHICH SHOULD LIMIT MOISTURE
RETURN IN ADVANCE OF ANOTHER COLD FRONT...FORECAST TO MOVE THROUGH
CENTRAL NORTH CAROLINA MONDAY. THE ECMWF IS DEEPER WITH THE MID-
LEVEL WAVE MOVING THROUGH THE REGION...WHILE THE GFS HAS A FLATTER
FLOW. IF THE ECMWF VERIFIES WITH ITS STRONGER MID-LEVEL WAVE...THERE
COULD BE SOME PATCHES OF LIGHT RAIN OR SPRINKLES PRECEDING THE
FRONT. FOR NOW...WILL OPT TO SHOW JUST AN INCREASE IN CLOUDS
OVERNIGHT SUNDAY THROUGH ABOUT THE FIRST HALF OF MONDAY AND LEAVE
OUT PRECIPITATION ON THE SEVENTH DAY. IF IT WOULD OCCUR...IT SHOULD
BE LIGHT AS BOTH THE GFS AND ECMWF DIMINISH THE AMOUNT OF MOISTURE
AHEAD OF THE FRONT AS IT HEADS SOUTH TOWARD CENTRAL NORTH CAROLINA.
THE TIGHTEST SURFACE GRADIENTS DURING THE PERIOD ARE LATE THURSDAY
AFTERNOON AND EVENING...EARLY SATURDAY...AND THEN SUNDAY WHEN A
LITTLE MORE IN THE WAY OF GUSTS SHOULD BE OBSERVED. TEMPERATURES IN
THE LATTER PART OF THE LONG-TERM PERIOD WILL AVERAGE BELOW THE
NORMALS OF AROUND 65 TO 70 FOR LATE MARCH. COOLEST DAY SHOULD BE
SATURDAY WITH THE LOWEST 1000-850MB THICKNESSES SUGGESTIVE OF ONLY
THE MID 40S IN THE TRIAD. WILL LEAN A CATEGORY ABOVE THAT AND CLOSER
TO THE MOS CONSENSUS...APPROACHING 50 IN THE IMMEDIATE TRIAD AND FAR
NORTHWEST PIEDMONT AND 50 TO 55 ELSEWHERE. SATURDAY NIGHT COULD
FEATURE SOME UPPER 20S FOR LOWS IF CLOUDS DIMINISH AS EXPECTED.
GRADUAL WARMING TREND THROUGH THE WEEKEND...EXPECTING HIGHS AROUND
NORMAL BY MONDAY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 813 PM MONDAY...
24 HOUR TAF PERIOD: CONDITIONS AREA CURRENTLY VFR ACROSS THE AREA.
THERE IS A CHANCE OF SUB-VFR CIGS DEVELOPING IN THE FOOTHILLS AS
WINDS BECOME MORE SOUTHEASTERLY ACROSS THAT AREA... JUST TO THE WEST
OF THE CWA... AND LOWER LEVEL MOISTURE CONSEQUENTLY INCREASES THERE
OVERNIGHT. LOW CONFIDENCE IN THE EXTENT TO WHICH THESE CLOUDS WILL
DEVELOP AND IF THEY WILL BE FAR ENOUGH EAST TO AFFECT THE TRIAD.
OTHERWISE... VFR CONDITIONS WILL PREVAIL THROUGH THE 24 HOUR PERIOD.
LONG TERM: FOG/LOW STRATUS WILL BE POSSIBLE WEDNESDAY MORNING. A
MOIST CONVECTIVE RETURN FLOW REGIME MOVES IN WEDNESDAY NIGHT AND
COULD KEEP WEATHER UNSETTLED THROUGH FRIDAY AS A COLD FRONT CROSSES
THE AREA.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ELLIS
NEAR TERM...ELLIS
SHORT TERM...ELLIS
LONG TERM...DJF
AVIATION...RAH/ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
700 AM EDT SUN MAR 22 2015
.SYNOPSIS...A WEAK COLD FRONT WILL MOVE ACROSS CENTRAL NC THIS
MORNING...FOLLOWED BY THE PASSAGE OF A STRONGER COLD FRONT TONIGHT.
A SERIES OF WEAK AREAS OF LOW PRESSURE WILL TRACK EAST ACROSS THE
DEEP SOUTH AND OFF THE SOUTH ATLANTIC COAST THROUGH MONDAY NIGHT.
HIGH PRESSURE WILL EXTEND INTO THE REGION FROM THE NORTHEAST ON
TUESDAY AND WEDNESDAY BEFORE THE NEXT COLD FRONT APPROACHES THE
REGION FROM THE WEST ON THURSDAY.
&&
.NEAR TERM /SUNDAY THROUGH MONDAY/...
AS OF 325 AM SUNDAY...
A SOUTHERN STREAM SHORT WAVE TROUGH LOCATED OVER TX AND OK EARLY
THIS MORNING WILL SHIFT EAST AND REACH THE SOUTH ATLANTIC COAST BY
LATE MONDAY AFTERNOON. FURTHER ALOFT...A STRONG SUBTROPICAL JET WITH
A MOISTURE CONNECTION FROM THE EASTERN PACIFIC WILL EXTEND ACROSS
THE SOUTHEAST DURING THE PERIOD WITH SPEEDS AT TIMES IN EXCES OF
125KTS. AT THE SURFACE...A SERIES OF WEAK SURFACE LOWS WILL MOVE
ACROSS THE NORTHERN GULF COAST AND INTO THE ATLANTIC NEAR THE FL/GA
COAST. FINALLY...A SOUTHWARD ADVANCING COLD FRONT LOCATED ACROSS
NORTHERN VA AT 06Z WILL DROP INTO CENTRAL NC LATER THIS MORNING WITH
A SECONDARY A STRONGER FRONT PUSHING INTO NC LATE TONIGHT.
TODAY WILL FEATURE MAINLY CLOUDY SKIES ACROSS CENTRAL NC ALTHOUGH
THE CLOUDINESS WILL BE OF A MID AND HIGH NATURE THIS MORNING
EVERYWHERE RESULTING IN A RELATIVELY BRIGHT OVERCAST. REGIONAL RADAR
SHOWS AN AREA OF LIGHT RAIN EXTENDING ACROSS AL AND GA AND NOW
CROSSING THE SAVANNAH RIVER INTO SC. THE NORTHERN EXTENT OF THIS
PRECIPITATION IS VERY LIGHT AND FALLING FROM MID LEVEL CLOUDS.
DETERMINISTIC NWP GUIDANCE HAS BEEN FAIRLY CONSISTENT IN DEPICTING A
SHARP BOUNDARY BETWEEN THE RAIN SHIELD RAIN AND DRY WEATHER TO THE
NORTH WITH THE BOUNDARY LIKELY SETTING UP JUST NORTH OF THE NORTH
CAROLINA-SOUTH CAROLINA BORDER. GIVEN RADAR TRENDS AND HIGHER
RESOLUTION GUIDANCE INCLUDING THE HRRR AND THE HI RES WINDOW
RUNS...HAVE INCREASED POPS AND QPF AMOUNTS FOR THE SOUTHERN MOST ROW
OF COUNTIES IN NC. STILL...CONFIDENCE IN HOW MUCH AND HOW FAR NORTH
THE PRECIPITATION WILL FALL IS LIMITED BUT IT APPEARS THAT
MEASURABLE RAIN TODAY WILL REMAIN SOUTH OF THE U.S. 64 CORRIDOR.
EVEN WHERE THERE IS A GOOD CHANCE OF RAIN SUCH AS FAYETTEVILLE...
GUIDANCE IS VARYING IN HOW MUCH. FOR EXAMPLE THE 21Z SREF 30-HOUR
FORECAST FOR FAY NOTES 4 OF THE 21 MEMBERS PRODUCING MORE THAN AN
INCH OF PRECIPITATION WHILE 6 MEMBERS HAVE LESS THAN 3 HUNDRETHS AND
THE START TIME OF THE PRECIPITATION VARIES JUST AS WIDELY. EVEN WITH
OVERCAST SKIES AND SOME SLIGHTLY COOLER AIR FILTERING IN FROM THE
NORTHEAST...HIGHS TODAY SHOULD GENERALLY RANGE IN THE LOWER TO MID
60S WITH THE COOLEST TEMPS IN THE NORTHEAST WITH HIGHS AROUND 60 AND
A FEW LOCATIONS ACROSS THE WESTERN PIEDMONT FLIRTING WITH THE UPPER
60S.
THE WEAK WAVES OF LOWER PRESSURE WILL CONTINUE TO SKIRT BY TO OUR
SOUTH TONIGHT AND MONDAY. A SECONDARY COLD FRONT WILL PUSH INTO NC
FROM THE NORTHEAST LATE TONIGHT AND EARLY MONDAY WITH NOTABLY COOLER
AN DRIER AIR. WIDESPREAD OVERCAST CONDITIONS ARE EXPECTED TONIGHT
INTO MONDAY WITH SOME THINNING OF THE CLOUD COVER EXPECTED LATE IN
THE DAY ACROSS THE NORTHERN AND WESTERN PIEDMONT. CHANCES OF LIGHT
RAIN WILL CONTINUE ACROSS THE SOUTHEAST. LIGHT NORTHEAST AND
EASTERLY WINDS WILL BECOME NORTHEAST AND INCREASE LATE TONIGHT AND
MONDAY BEHIND THE FRONT WITH SOME GUSTS REACHING THE 15-20 MPH
RANGE. LOWS TONIGHT WILL RANGE FROM AROUND 40 TO 45 WITH HIGHS ON
MONDA IN THE LOWER 50S. -BLAES
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 320 AM SUNDAY...
MONDAY NIGHT THROUGH TUESDAY...
S/W IN THE SOUTHERN STREAM WILL CONTINUE TO SHEAR OUT AS IT
PROGRESSES EASTWARD ACROSS SOUTH CAROLINA. MEANWHILE A PARENT SFC
HIGH OVER NEW ENGLAND WILL CONTINUE TO NOSE/BUILD SOUTHWARD INTO THE
CAROLINAS. THIS SFC WEATHER SYSTEM WILL CONTINUE TO ADVECT A
COOLER/DRIER LOW LEVEL AIR MASS INTO THE REGION.
ANY PRECIP OVER THE FAR SOUTH-SE SECTIONS OF THE FORECAST AREA WILL
GRADUALLY DIMINISH AS LIFT ASSOCIATED WITH THE S/W WEAKENS. MIN
TEMPS MONDAY NIGHT MID-UPPER 30S.
THE SURFACE PATTERN FOR TUESDAY WITH A PARENT HIGH CENTERED OVER NEW
ENGLAND AND SLY AND/OR BACKING FLOW IN THE 850MB-700MB LAYER WIL
SUPPORT A WEAK CLASSICAL COLD AIR DAMMING EVENT FOR TUESDAY.
CONSIDERABLE CLOUDINESS AND A SFC NE WIND SHOULD LEAD TO AFTERNOON
TEMPS 7-10 DEGREES BELOW NORMAL (AT LEAST). TUESDAY
NIGHT...INCREASING SLY FLOW IN THE 925-850MB SHOULD CAUSE PATCHES OF
DRIZZLE TO OCCUR ALONG WITH EXTENSIVE LOW CLOUDS. MIN TEMPS UPPER
30S-LOWER 40S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 320 AM SUNDAY...
WEDNESDAY THROUGH SATURDAY... UPPER AIR PATTERN WILL EVOLVE THIS
PERIOD INTO A PATTERN SIMILAR TO THE LAST HALF OF TIS WINTER SEASON
WITH A PRONOUNCED RIDGE IN THE WEST AND A TROUGH OVER THE EAST. THE
LEAD S/W INITIATING THIS PATTERN EVOLUTION WILL CROSSING THE PLAINS
STATES WEDNESDAY. CLOSER TO HOME...SFC RIDGE WILL DRIFT OFFSHORE IN
RESPONSE TO THE APPROACHING S/W...WITH A SLY LOW LEVEL FLOW
INCREASING ACROSS OUR REGION. THIS FLOW OVER THE COOL STABLE DOME OF
AIR LEFTOVER FROM THE CAD EVENT TUESDAY SHOULD CAUSE EXTENSIVE
CLOUDINESS WEDNESDAY MORNING ALONG WITH PATCHES OF DRIZZLE OR DENSE
FOG. MODELS HINT AT SOME EXTENSION OF THE RIDGE PERSISTING OVER OUR
REGION SO THE LOW CLOUDS MAY HOLD ON LONGER THAN PREDICTED BY THE
MODELS WHICH MAY CAUSE HIGH TEMPS WEDNESDAY TO BE COOLER THAN
FORECAST. HAVE LOWERED MAX TEMPS ABOUT A CATEGORY FROM THE PREVIOUS
FORECAST AND THIS MAY NOT BE ENOUGH. THIS WILL NEED TO BE RE-
EVALUATED WITH LATER MODEL RUNS. WITH THE INCREASING SLY FLOW WILL
COME A THREAT FOR A FEW SHOWERS WEDNESDAY. HAVE INTRODUCED A SLIGHT
CHANCE POP FOR WEDNESDAY.
LEAD S/W WILL LIFT WELL NORTH OF OUR REGION THROUGH A SHEAR AXIS AND
SFC FRONT WILL EXTEND SOUTHWARD INTO THE TN VALLEY THURSDAY
MORNING...MOVING INTO THE CAROLINA PIEDMONT BY LATE THURSDAY-
THURSDAY EVENING. 00Z GFS DEPICTS A SLIGHTLY UNSTABLE AIR MASS WITH
SFC BASED CAPE VALUES 1000-1400 J/KG AND MUCAPE JUST SHY OF 1000
J/KG. BULK SHEAR INCREASES TO 35-45 KTS BY LATE IN THE DAY. THE CAPE
VALUES MAY BE ACHIEVED IF ENOUGH HEATING OCCURS WHICH IS
QUESTIONABLE AS CONSIDERABLE CLOUDINESS FROM RESIDUAL CAD MAY STILL
BE AN ISSUE. WILL MAINTAIN CHANCE POPS FOR THURSDAY AFTERNOON-
THURSDAY NIGHT ALONG WITH A MENTION OF THUNDER BASED ON THE ABOVE
CONVECTIVE PARAMETERS. HIGH TEMPS THURSDAY COULD END UP BEING 3-5
DEGREES COOLER...BASED ON WHETHER CLOUDS/SHOWERS MORE EXTENSIVE THAN
CURRENT THINKING. MILD WEDNESDAY NIGHT AHEAD OF THE FRONT WITH
OVERNIGHT TEMPS IN THE MID-UPPER 50S. HIGHS THURSDAY LOWER 70S NW TO
UPPER 70S SE.
UNSETTLED WEATHER EXPECTED FRIDAY THROUGH EARLY SATURDAY AS A SERIES
OF S/WS ALOFT DIG THE UPPER TROUGH OVER THE EASTERN U.S. WHILE
FRONTAL PASSAGE EXPECTED THURSDAY NIGHT...COULD SEE POCKETS OF LIGHT
RAIN TRAVERSE ACROSS THE REGION FRIDAY...FRIDAY NIGHT AND POSSIBLY
SATURDAY ASSOCIATED WITH THE S/WS ALOFT. UPPER TROUGH OVERHEAD WILL
LEAD TO A PERIOD OF BELOW NORMAL HIGH TEMPS...AVERAGING 10-15
DEGREES BELOW NORMAL.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
AS OF 700 AM SUNDAY...
24 HOUR TAF PERIOD...OUTSIDE OF A FEW PATCHES OF FOG THIS
MORNING...VFR CONDITIONS ARE WIDESPREAD ACROSS CENTRAL NC THIS
MORNING. HOWEVER...A SERIES OF WEAK AREAS OF LOW PRESSURE WILL HELP
GENERATE A LARGE AREA OF LIGHT RAIN ACROSS THE DEEP SOUTH THROUGH
MONDAY. THE MAJORITY OF THIS PRECIPITATION WILL FALL SOUTH OF THE
KINT...KGSO...KRDU...AND KRWI TERMINALS WITH A RELATIVELY SHARP
BOUNDARY BETWEEN RAIN AND NO RAIN LIKELY TO EXTEND ALONG AND JUST
NORTH OF THE NORTH AND SOUTH CAROLINA BORDER. SOME OF THE RAIN WILL
LIKELY REACH THE KFAY TERMINAL LATER THIS MORNING OR MORE LIKELY
DURING THE AFTERNOON. CONFIDENCE REGARDING HOW MUCH AND HOW FAR
NORTH THE PRECIPITATION WILL FALL IS LOW. AT LEAST INITIALLY...MUCH
OF THE PRECIPITATION WILL FALL FROM MID LEVEL CLOUDS AND THE EXTENT
OF CEILING REDUCTION AT KFAY IS UNCERTAIN BUT FEEL IT IS PROBABLE
THAT AT LEAST A PERIOD OF MVFR CIGS AND VSBYS WILL OCCUR THIS
EVENING. AFTER MIDNIGHT...LOW LEVEL MOISTURE WILL INCREASE AND MORE
WIDESPREAD LOW CEILINGS AT 2500-3500 FEET ARE EXPECTED ACROSS ALL OF
THE TERMINALS. CALM OR VERY LIGHT SOUTHWESTERLY WINDS EARLY THIS
MORNING WILL BECOME NORTHEASTERLY AND INCREASINGLY GUSTY WITH THE
PASSAGE OF A COLD FRONT THIS MORNING AND EARLY AFTERNOON. A BAND OF
LOWER CLOUDS IS LIKELY TO BE ATTENDANT TO THE FRONT WITH IFR-MVFR
CIGS.
OUTLOOK... THE POTENTIAL FOR SOME LIGHT RAIN...MAINLY TO THE SOUTH
OF KRDU AND KRWI CONTINUES LATE TONIGHT INTO MONDAY AFTERNOON.
REDUCED CIGS ARE LIKELY TO PERSIST FROM MONDAY INTO TUESDAY MORNING.
ADVERSE AVIATION CONDITIONS ARE LIKELY TO DEVELOP WEDNESDAY AND
WEDNESDAY NIGHT WITH A MOIST SOUTHEAST FLOW PRODUCING LOW STRATUS
AND SOME RAIN. ANOTHER ROUND OF ADVERSE AVIATION CONDITION ARE
PROBABLE ON THURSDAY AS A COLD FRONT PRODUCES SCATTERED SHOWERS AS
IT APPROACHES THE REGION. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 AM EDT SUN MAR 22 2015
.SYNOPSIS...A WEAK COLD FRONT WILL MOVE ACROSS CENTRAL NC THIS
MORNING...FOLLOWED BY THE PASSAGE OF A STRONGER COLD FRONT TONIGHT.
A SERIES OF WEAK AREAS OF LOW PRESSURE WILL TRACK EAST ACROSS THE
DEEP SOUTH AND OFF THE SOUTH ATLANTIC COAST THROUGH MONDAY NIGHT.
HIGH PRESSURE WILL EXTEND INTO THE REGION FROM THE NORTHEAST ON
TUESDAY AND WEDNESDAY BEFORE THE NEXT COLD FRONT APPROACHES THE
REGION FROM THE WEST ON THURSDAY.
&&
.NEAR TERM /SUNDAY THROUGH MONDAY/...
AS OF 325 AM SUNDAY...
A SOUTHERN STREAM SHORT WAVE TROUGH LOCATED OVER TX AND OK EARLY
THIS MORNING WILL SHIFT EAST AND REACH THE SOUTH ATLANTIC COAST BY
LATE MONDAY AFTERNOON. FURTHER ALOFT...A STRONG SUBTROPICAL JET WITH
A MOISTURE CONNECTION FROM THE EASTERN PACIFIC WILL EXTEND ACROSS
THE SOUTHEAST DURING THE PERIOD WITH SPEEDS AT TIMES IN EXCES OF
125KTS. AT THE SURFACE...A SERIES OF WEAK SURFACE LOWS WILL MOVE
ACROSS THE NORTHERN GULF COAST AND INTO THE ATLANTIC NEAR THE FL/GA
COAST. FINALLY...A SOUTHWARD ADVANCING COLD FRONT LOCATED ACROSS
NORTHERN VA AT 06Z WILL DROP INTO CENTRAL NC LATER THIS MORNING WITH
A SECONDARY A STRONGER FRONT PUSING INTO NC LATE TONIGHT.
TODAY WILL FEATURE MAINLY CLOUDY SKIES ACROSS CENTRAL NC ALTHOUGH
THE CLOUDINESS WILL BE OF A MID AND HIGH NATURE THIS MORNING
EVERYWHERE RESULTING IN A RELATIVELY BRIGHT OVERCAST. REGIONAL RADAR
SHOWS AN AREA OF LIGHT RAIN EXTENDING ACROSS AL AND GA AND NOW
CROSSING THE SAVANNAH RIVER INTO SC. THE NORTHERN EXTENT OF THIS
PRECIPITATION IS VERY LIGHT AND FALLING FROM MID LEVEL CLOUDS.
DETERMINISTIC NWP GUIDANCE HAS BEEN FAIRLY CONSISTENT IN DEPICTING A
SHARP BOUNDARY BETWEEN THE RAIN SHIELD RAIN AND DRY WEATHER TO THE
NORTH WITH THE BOUNDARY LIKELY SETTING UP JUST NORTH OF THE NORTH
CAROLINA-SOUTH CAROLINA BORDER. GIVEN RADAR TRENDS AND HIGHER
RESOLUTION GUIDANCE INCLUDING THE HRRR AND THE HI RES WINDOW
RUNS...HAVE INCREASED POPS AND QPF AMOUNTS FOR THE SOUTHERN MOST ROW
OF COUNTIES IN NC. STILL...CONFIDENCE IN HOW MUCH AND HOW FAR NORTH
THE PRECIPITATION WILL FALL IS LIMITED BUT IT APPEARS THAT
MEASURABLE RAIN TODAY WILL REMAIN SOUTH OF THE U.S. 64 CORRIDOR.
EVEN WHERE THERE IS A GOOD CHANCE OF RAIN SUCH AS FAYETTEVILLE...
GUIDANCE IS VARYING IN HOW MUCH. FOR EXAMPLE THE 21Z SREF 30-HOUR
FORECAST FOR FAY NOTES 4 OF THE 21 MEMBERS PRODUCING MORE THAN AN
INCH OF PRECIPITATION WHILE 6 MEMBERS HAVE LESS THAN 3 HUNDRETHS AND
THE START TIME OF THE PRECIPITATION VARIES JUST AS WIDELY. EVEN WITH
OVERCAST SKIES AND SOME SLIGHTLY COOLER AIR FILTERING IN FROM THE
NORTHEAST...HIGHS TODAY SHOULD GENERALLY RANGE IN THE LOWER TO MID
60S WITH THE COOLEST TEMPS IN THE NORTHEAST WITH HIGHS AROUND 60 AND
A FEW LOCATIONS ACROSS THE WESTERN PIEDMONT FLIRTING WITH THE UPPER
60S.
THE WEAK WAVES OF LOWER PRESSURE WILL CONTINUE TO SKIRT BY TO OUR
SOUTH TONIGHT AND MONDAY. A SECONDARY COLD FRONT WILL PUSH INTO NC
FROM THE NORTHEAST LATE TONIGHT AND EARLY MONDAY WITH NOTABLY COOLER
AN DRIER AIR. WIDESPREAD OVERCAST CONDITIONS ARE EXPECTED TONIGHT
INTO MONDAY WITH SOME THINNING OF THE CLOUD COVER EXPECTED LATE IN
THE DAY ACROSS THE NORTHERN AND WESTERN PIEDMONT. CHANCES OF LIGHT
RAIN WILL CONTINUE ACROSS THE SOUTHEAST. LIGHT NORTHEAST AND
EASTERLY WINDS WILL BECOME NORTHEAST AND INCREASE LATE TONIGHT AND
MONDAY BEHIND THE FRONT WITH SOME GUSTS REACHING THE 15-20 MPH
RANGE. LOWS TONIGHT WILL RANGE FROM AROUND 40 TO 45 WITH HIGHS ON
MONDA IN THE LOWER 50S. -BLAES
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 320 AM SUNDAY...
MONDAY NIGHT THROUGH TUESDAY...
S/W IN THE SOUTHERN STREAM WILL CONTINUE TO SHEAR OUT AS IT
PROGRESSES EASTWARD ACROSS SOUTH CAROLINA. MEANWHILE A PARENT SFC
HIGH OVER NEW ENGLAND WILL CONTINUE TO NOSE/BUILD SOUTHWARD INTO THE
CAROLINAS. THIS SFC WEATHER SYSTEM WILL CONTINUE TO ADVECT A
COOLER/DRIER LOW LEVEL AIR MASS INTO THE REGION.
ANY PRECIP OVER THE FAR SOUTH-SE SECTIONS OF THE FORECAST AREA WILL
GRADUALLY DIMINISH AS LIFT ASSOCIATED WITH THE S/W WEAKENS. MIN
TEMPS MONDAY NIGHT MID-UPPER 30S.
THE SURFACE PATTERN FOR TUESDAY WITH A PARENT HIGH CENTERED OVER NEW
ENGLAND AND SLY AND/OR BACKING FLOW IN THE 850MB-700MB LAYER WIL
SUPPORT A WEAK CLASSICAL COLD AIR DAMMING EVENT FOR TUESDAY.
CONSIDERABLE CLOUDINESS AND A SFC NE WIND SHOULD LEAD TO AFTERNOON
TEMPS 7-10 DEGREES BELOW NORMAL (AT LEAST). TUESDAY
NIGHT...INCREASING SLY FLOW IN THE 925-850MB SHOULD CAUSE PATCHES OF
DRIZZLE TO OCCUR ALONG WITH EXTENSIVE LOW CLOUDS. MIN TEMPS UPPER
30S-LOWER 40S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 320 AM SUNDAY...
WEDNESDAY THROUGH SATURDAY... UPPER AIR PATTERN WILL EVOLVE THIS
PERIOD INTO A PATTERN SIMILAR TO THE LAST HALF OF TIS WINTER SEASON
WITH A PRONOUNCED RIDGE IN THE WEST AND A TROUGH OVER TEH EAST. THE
LEAD S/W INITIATING THIS PATTERN EVOLUTION WILL CROSSING THE PLAINS
STATES WEDNESDAY. CLOSER TO HOME...SFC RIDGE WILL DRIFT OFFSHORE IN
RESPONSE TO THE APPROACHING S/W...WITH A SLY LOW LEVEL FLOW
INCREASING ACROSS OUR REGION. THIS FLOW OVER THE COOL STABLE DOME OF
AIR LEFTOVER FROM THE CAD EVENT TUESDAY SHOULD CAUSE EXTENSIVE
CLOUDINESS WEDNESDAY MORNING ALONG WITH PATCHES OF DRIZZLE OR DENSE
FOG. MODELS HINT AT SOME EXTENSION OF THE RIDGE PERSISTING OVER OUR
REGION SO THE LOW CLOUDS MAY HOLD ON LONGER THAN PREDICTED BY THE
MODELS WHICH MAY CAUSE HIGH TEMPS WEDNESDAY TO BE COOLER THAN
FORECAST. HAVE LOWERED MAX TEMPS ABOUT A CATEGORY FROM THE PREVIOUS
FORECAST AND THIS MAY NOT BE ENOUGH. THIS WILL NEED TO BE RE-
EVALUATED WITH LATER MODEL RUNS. WITH THE INCREASING SLY FLOW WILL
COME A THREAT FOR A FEW SHOWERS WEDNESDAY. HAVE INTRODUCED A SLIGHT
CHANCE POP FOR WEDNESDAY.
LEAD S/W WILL LIFT WELL NORTH OF OUR REGION THROUGH A SHEAR AXIS AND
SFC FRONT WILL EXTEND SOUTHWARD INTO THE TN VALLEY THURSDAY
MORNING...MOVING INTO THE CAROLINA PIEDMONT BY LATE THURSDAY-
THURSDAY EVENING. 00Z GFS DEPICTS A SLIGHTLY UNSTABLE AIR MASS WITH
SFC BASED CAPE VALUES 1000-1400 J/KG AND MUCAPE JUST SHY OF 1000
J/KG. BULK SHEAR INCREASES TO 35-45 KTS BY LATE IN THE DAY. THE CAPE
VALUES MAY BE ACHIEVED IF ENOUGH HEATING OCCURS WHICH IS
QUESTIONABLE AS CONSIDERABLE CLOUDINESS FROM RESIDUAL CAD MAY STILL
BE AN ISSUE. WILL MAINTAIN CHANCE POPS FOR THURSDAY AFTERNOON-
THURSDAY NIGHT ALONG WITH A MENTION OF THUNDER BASED ON THE ABOVE
CONVECTIVE PARAMETERS. HIGH TEMPS THURSDAY COULD END UP BEING 3-5
DEGREES COOLER...BASED ON WHETHER CLOUDS/SHOWERS MORE EXTENSIVE THAN
CURRENT THINKING. MILD WEDNESDAY NIGHT AHEAD OF THE FRONT WITH
OVERNIGHT TEMPS IN THE MID-UPPER 50S. HIGHS THURSDAY LOWER 70S NW TO
UPPER 70S SE.
UNSETTLED WEATHER EXPECTED FRIDAY THROUGH EARLY SATURDAY AS A SERIES
OF S/WS ALOFT DIG THE UPPER TROUGH OVER THE EASTERN U.S. WHILE
FRONTAL PASSAGE EXPECTED THURSDAY NIGHT...COULD SEE POCKETS OF LIGHT
RAIN TRAVERSE ACROSS THE REGION FRIDAY...FRIDAY NIGHT AND POSSIBLY
SATURDAY ASSOCIATED WITH THE S/WS ALOFT. UPPER TROUGH OVERHEAD WILL
LEAD TO A PERIOD OF BELOW NORMAL HIGH TEMPS...AVERAGING 10-15
DEGREES BELOW NORMAL.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 240 AM SUNDAY...
24 HOUR TAF PERIOD...A SERIES OF WEAK AREAS OF LOW PRESSURE WILL
HELP GENERATE A LARGE AREA OF LIGHT RAIN ACROSS THE DEEP SOUTH
THROUGH MONDAY. THE MAJORITY OF THIS PRECIPITATION WILL FALL SOUTH
OF THE RAH TERMINALS WITH A RELATIVELY SHARP BOUNDARY BETWEEN RAIN
AND NO RAIN LIKELY TO EXTEND NEAR AND JUST NORTH OF THE NORTH AND
SOUTH CAROLINA BORDER. SOME OF THE RAIN WILL LIKELY REACH THE KFAY
TERMINAL LATE THIS AFTERNOON OR EARLY THIS EVENING WITH THE
PRECIPITATION LIKELY REMAINING SOUTH OF THE REMAINDER OF THE
TERMINALS FOR MOST OF THE OVERNIGHT. CONFIDENCE IN HOW MUCH AND HOW
FAR NORTH THE PRECIPITATION WILL FALL IS LOW. AT LEAST INITIALLY
MUCH OF THE PRECIPITATION WILL FALL FROM MID LEVEL CLOUDS AND THE
EXTENT OF CEILING REDUCTION AT KFAY IS UNCERTAIN BUT FEEL IT IS
PROBABLE THAT AT LEAST A PERIOD OF MVFR CIGS AND VSBYS WILL OCCUR
THIS EVENING. AFTER MIDNIGHT...LOW LEVEL MOISTURE WILL INCREASE AND
MORE WIDESPREAD LOW CEILINGS AT 2500-3500 FEET ARE EXPECTED ACROSS
ALL OF THE TERMINALS. CALM OR VERY LIGHT SOUTHWESTERLY WINDS ARE
EXPECTED EARLY THIS MORNING AND THEN BECOME NORTHEASTERLY WITH THE
PASSAGE OF A WEAK COLD FRONT THIS MORNING.
OUTLOOK... ANOTHER COLD FRONT WILL MOVE THROUGH CENTRAL NC TONIGHT
PRODUCING A SURGE OF STRONGER NORTHEAST WINDS INTO MONDAY WITH A
PERIOD OF MVFR CEILINGS IN STRATUS. THE POTENTIAL FOR SOME LIGHT
RAIN MAINLY SOUTH OF KRDU AND KRWI PERSISTS LATE TONIGHT INTO MONDAY
AFTERNOON. REDUCED CIGS ARE LIKELY TO PERSIST FROM MONDAY INTO
TUESDAY MORNING. ADVERSE AVIATION CONDITIONS ARE LIKELY TO DEVELOP
WEDNESDAY AND WEDNESDAY NIGHT WITH A MOIST SOUTHEAST FLOW PRODUCING
LOW STRATUS AND SOME RAIN. ANOTHER ROUND OF ADVERSE CONDITION ARE
PROBABLY ON THURSDAY AS A COLD FRONT PRODUCES SCATTERED SHOWERS AS
IT APPROACHES THE REGION. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1242 PM CDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 1241 PM CDT SUN MAR 22 2015
LIGHT SNOW ALONG AND EAST OF A LINE FROM HARVEY TO BISMARCK SHOULD
END FROM NORTHWEST TO SOUTHEAST THROUGH THE AFTERNOON. TEMPERATURES
IN THE FAR WEST HAVE RISEN INTO THE 40S...BUT IT APPEARS
TEMPERATURES CLOSER TO THE MISSOURI RIVER WILL BE SLOW TO RISE AND
HAVE LOWERED EXPECTED MAXIMUM TEMPERATURES THERE.
UPDATE ISSUED AT 1053 AM CDT SUN MAR 22 2015
MAIN UPDATE TO END THE FREEZING RAIN ADVISORY SOUTHWEST. ICY ROADS
WILL LINGER THERE UNTIL TEMPERATURES RISE ABOVE FREEZING. ALSO
INCREASED CHANCES OF LIGHT SNOW FAR SOUTHWEST FOR THE AFTERNOON
HOURS. UPDATED HOURLY TEMPERATURE TRENDS. UPDATED FORECASTS WILL
BE ISSUED SHORTLY.
UPDATE ISSUED AT 940 AM CDT SUN MAR 22 2015
MAIN CONCERN IS PRECIPITATION TYPE ACROSS THE SOUTHWEST AND SOUTH
CENTRAL. FEW OBSERVATION POINTS THIS AREA. RADAR ECHOES HAD EXPANDED
FROM GRANT AND SIOUX COUNTY INTO EMMONS/LOGAN/MCINTOSH COUNTIES AND
FEAR WAS THAT FREEZING RAIN MIGHT BE OCCURRING THERE. BRIGHT BAND OF
REFLECTIVITY FROM HETTINGER TO SOUTHERN GRANT INTO SIOUX COUNTY INTO
LOGAN/MCINTOSH...WITH RADAR SUGGESTING SLEET. REPORTS WEST IN SLOPE
COUNTY AND HETTINGER WERE FREEZING RAIN...JUST RECENTLY GOT REPORTS
OF SNOW NEAR THE CORNER OF EMMONS/LOGAN/MCINTOSH COUNTY. THUS
APPEARS FREEZING RAIN WAS CHANGING TO SNOW EAST OF THE MISSOURI
RIVER. MAIN BAND OF PRECIPITATION WAS MOVING SOUTH AND EAST...AND BY
11 AM CDT/10 AM MDT THE BULK OF PRECIPITATION SHOULD BE SOUTH AND
EAST OF OUR AREA. THUS WILL KEEP THE FREEZING RAIN ADVISORY GOING
FOR SOUTHWESTERN NORTH DAKOTA UNTIL SAID TIME.
OTHER CHANGE WAS THAT SURFACE TEMPERATURES IN THE SOUTHWEST WERE NOT
RISING AS QUICKLY AS FORECAST. HOWEVER EXPECT RISING TEMPERATURES TO
COMMENCE WITHIN AN HOUR OR TWO AND BEGIN RISING INTO THE 40S BY LATE
MORNING...AS WINDS IN THE FAR WEST BECOME SOUTH AND THEN TURN WEST
BRINGING WARMER AIR INTO THE REGION.
UPDATE ISSUED AT 705 AM CDT SUN MAR 22 2015
MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST BY BLENDING IN CURRENT
CONDITIONS. AREA RADARS STILL SHOW LIGHT PRECIPITATION MOVING
ACROSS WESTERN AND CENTRAL NORTH DAKOTA...WITH THE LATEST MESO-
SCALE MODELS FOCUSING MOST OF THEIR ATTENTION ON THE PRECIPITATION
ACROSS SOUTHERN NORTH DAKOTA. THE FREEZING RAIN ADVISORY STILL
LOOKS WELL PLACED AND WILL LEAVE AS IS.
UPDATE
ISSUED AT 512 AM CDT SUN MAR 22 2015
QUICK UPDATE TO ISSUE A FREEZING RAIN ADVISORY FOR THE SOUTHWEST
CORNER. JUST HAD A REPORT OF ICY CONDITIONS NEAR HEBRON ON I94
WITH AN ACCIDENT AND SEMI TRUCKS STRUGGLING TO DRIVE UP HILLS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM CDT SUN MAR 22 2015
FORECAST HIGHLIGHTS AND CHALLENGES IN THE SHORT TERM PERIOD WILL
BE THE THREAT FOR FREEZING PRECIPITATION ACROSS THE SOUTHWEST THIS
MORNING...AND HOW PRECIPITATION EVOLVES EASTWARD.
CURRENTLY...ACTIVE ZONAL FLOW ALOFT WITH A POTENT SHORT WAVE
MOVING EAST INTO SOUTH CENTRAL CANADA AND ANOTHER MORE
SUBTLE/EMBEDDED FEATURE MOVING EAST ACROSS NORTHERN
WYOMING/SOUTHEASTERN MONTANA. ASSOCIATED SURFACE LOWS OVER
SOUTHERN SASKATCHEWAN AND EASTERN WY/SOUTHWESTERN SD RESPECTIVELY.
THE SOUTHERN MOST WAVE IS OUR MAIN CONCERN...GENERATING
PRECIPITATION FROM SOUTHEASTERN MONTANA EAST TO ACROSS
SOUTHWESTERN NORTH DAKOTA. THERMAL PROFILES AND SFC TEMPERATURES
INDICATING LIGHT FREEZING RAIN IS LIKELY FALLING. MADE A FEW CALLS
TO THE SOUTHWEST WHICH INDICATED NO IMPACTS AS SO FAR THE LIGHT
FREEZING PRECIP IS ONLY TRACING OUT. A VERY DRY EASTERLY FLOW IS
KEEPING THE BOUNDARY LAYER RATHER DRY FROM THE SURFACE UP TO 5-7K
FT AGL...SO ANY MOISTURE REACHING THE GROUND SHOULD BE LIMITED.
WILL MAINTAIN LIKELY POPS SOUTHWEST INTO SOUTH CENTRAL. HAVE A
SPECIAL WEATHER STATEMENT OUT NOW FOR THE FREEZING RAIN
POTENTIAL...AND WILL CONTINUE WITH THIS UNLESS WE HEAR OF MORE
IMPACTS AND A FREEZING RAIN ADVISORY BECOMES NEEDED. MORE RADAR
RETURNS ACROSS THE NORTH...BUT AGAIN WITH CLOUD BASES AT ROUGHLY
8-10K AGL...ANTICIPATE LITTLE IS REACHING THE GROUND SO WILL KEEP
POPS BELOW LIKELY THERE.
MODELS HAVING A HARD TIME THIS MORNING WITH EACH RUN OF THE HRRR
AND NAM MODELS DIFFERENT. BASICALLY WENT WITH A BLEND WHICH
FOLLOWS THE 00Z ECMWF AND LATEST 06Z NAM RATHER WELL. THIS
CONFINES HIGHER POPS THIS MORNING TO MY SOUTHERN COUNTIES...ALONG
TO SOUTH OF INTERSTATE 94. MAIN THREAT FOR FREEZING RAIN WILL
REMAIN WEST OF THE MISSOURI RIVER ACROSS MY SOUTHWEST THROUGH MID
MORNING...WITH THERMAL PROFILES SUGGESTING ALL SNOW TO THE EAST.
SURFACE FRONTAL BOUNDARY MOMENTARILY STALLS ACROSS THE WEST THIS
AFTERNOON...WITH A WESTERLY WIND TO THE WEST AND SOUTHERLY WIND
TO THE EAST. NAM AND RAP ARE INDICATING POSSIBLE STRATUS
DEVELOPMENT ALONG TO EAST OF THE BOUNDARY LATER TODAY INTO THIS
EVENING AS THE SOUTH/SOUTHEASTERLY FLOW TRANSPORTS MOISTURE NORTH.
THUS WILL KEEP SKY COVER ELEVATED ABOVE MOSTLY SUNNY/MOSTLY CLEAR.
CONFIDENCE NOT HIGH WITH THIS PLAYING OUT WITH MODELS STRUGGLING
THE PAST FEW RUNS.
AFOREMENTIONED STRONG SHORT WAVE CUTTING EAST ACROSS SOUTH CENTRAL
CANADA WILL TURN SOUTHEAST AND MOVE INTO FAR NORTHEASTERN
ND/NORTHERN MINNESOTA THIS SUNDAY NIGHT. PRECIPITATION IN THE FORM
OF SNOW MAY GRAZE MY FAR NORTHEAST SO WILL MAINTAIN A LOW POP THERE
TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM CDT SUN MAR 22 2015
THE PRIMARY CONCERN IN THE LONG TERM PERIOD WILL BE THE POTENT
STORM MONDAY NIGHT INTO TUESDAY. THE LATEST MODEL SUITE CONTINUES
TO ADVERTISE A POTENT STORM SYSTEM ACROSS THE NORTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. DETAILS REGARDING THE EXACT TRACK OF
THE SYSTEM REMAIN ELUSIVE WITH THE 00Z GFS AND ECMWF STILL SHOWING
DIFFERENCES...AND LARGE SPREAD INDICATED BY THE GEFS.
THE ECMWF AND GFS BOTH SUGGEST TWO SURFACE LOWS WILL
DEVELOP...HOWEVER THEY DIFFER ON THE PROGRESSION OF THE NORTHERN
MOST LOW. THE ECMWF KEEPS THE LOWS SEPARATE WITH ONE TRACKING INTO
CANADA...WHILE THE GFS MERGES THE LOWS IN MINNESOTA / WISCONSIN.
HAVE AGAIN GONE WITH A BLENDED MODEL SOLUTION DUE TO THE
UNCERTAINTY. THIS MAINTAINS SOME CONSISTENCY IN THE FORECAST WITH
WARM AIR AND RAIN EXPECTED ACROSS MUCH OF CENTRAL AND WESTERN
NORTH DAKOTA DURING THE MORNING AND AFTERNOON TUESDAY. THE
EXCEPTION COULD BE THE FAR NORTH AND WEST WHERE COLDER AIR MAY
FAVOR SNOW. COLD AIR ARRIVES BEHIND THE LOW TUESDAY NIGHT...WHICH
SUPPORTS A THERMAL PROFILE TRANSITIONING TO SNOW ACROSS THE
FORECAST AREA. CONFIDENCE IN PRECIPITATION AND / OR SNOW AMOUNTS
REMAINS LOW DUE TO THE LARGE DIFFERENCES IN MODEL SOLUTIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 124 PM CDT SUN MAR 22 2015
LIGHT SNOW TO CONTINUE EAST OF A LINE FROM HARVEY TO BISMARCK THIS
AFTERNOON...ENDING FROM WEST TO EAST. KJMS TO SEE S- IN MVFR CIGS
FROM 20Z-23Z. OTHERWISE MVFR CIGS FROM HARVEY TO KBIS AND
EASTWARD...BECOMING VFR DURING THIS AFTERNOON. RETURN OF MVFR CIGS
EXPECTED BY AROUND 02Z/03Z WITH SOUTHERLY WINDS REMAINING AT
KBIS/KJMS/KMOT. A COLD FRONT TO MOVE INTO KISN FROM THE NORTH AROUND
03Z-06Z TO BRING MVFR CIGS...REACHING KDIK 09Z-12Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...NH
LONG TERM...CK
AVIATION...JV
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1238 PM CDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 1237 PM CDT SUN MAR 22 2015
AFTER WATCHING THE STREAMING WEB CAM AT OAKES JUST OUTSIDE OF THE
SOUTHWESTERN CWA...FLAKES HAVE STARTED TO FALL AFTER SEVERAL HOURS
OF RADAR RETURNS OVERHEAD. NOTHING ACCUMULATING SO FAR...THE RAP
AND HRRR STILL HAVE SOME QPF GETTING INTO OUR FAR SOUTHERN CWA
THIS AFTERNOON. WILL CONTINUE TO KEEP HIGH POPS IN THE FAR SOUTH
BUT TIGHTENED THE NORTHERN EDGE OF IT AND LOWERED SNOW AMOUNTS AS
IT SEEMS THAT THE BULK OF THE SNOW WILL BE TO OUR SOUTH. TWEAKED
TEMPS A BIT...RAISING THEM IN SOME AREAS AND LOWERED THEM IN
OTHERS. THE NORTHEASTERN COUNTIES HAVE STAYED SUNNY AND ARE
FINALLY GETTING UP TO THE LOWER 30S. THE TEMPS ARE ALSO IN THE
LOWER 30S IN THE SOUTHWESTERN COUNTIES WITH CLOUDS BUT THINK THERE
MAY BE A BIT OF A DROP AS WE GET EVAPORATIVE COOLING AS THE PRECIP
STARTS TO MOVE INTO THE REGION.
UPDATE ISSUED AT 1001 AM CDT SUN MAR 22 2015
BAND OF PRECIP CONTINUES TO MOVE EASTWARD TOWARDS OUR SOUTHWESTERN
COUNTIES. HOWEVER...WEB CAMS NEAR WISHEK WHICH HAS HAD RADAR
RETURNS MOVING OVERHEAD FOR THE LAST FEW HOURS SHOW THAT NOT MUCH
IS REACHING THE GROUND SO FAR. MODEL SOUNDINGS CONTINUE TO SHOW A
DRY LAYER NEAR THE SFC WHICH DOES NOT REALLY SATURATE UNTIL WELL
INTO THE AFTERNOON HOURS. CONTINUED TO KEEP SOME LIKELY POPS IN
THE FAR SOUTHERN COUNTIES FOR THIS AFTERNOON AS WE WILL NOT SEE
MUCH BEFORE THEN...BUT WILL HAVE TO WATCH TO SEE HOW THE BATTLE
BETWEEN DRY AIR AND FRONTOGENESIS UNFOLDS AND MAKE ADJUSTMENTS AS
NEEDED.
UPDATE ISSUED AT 650 AM CDT SUN MAR 22 2015
BAND OF PRECIP IS SETTING UP ACROSS SOUTHERN NORTH DAKOTA...AND
LATEST HI-RES GUIDANCE INDICATES THIS BAND WILL AFFECT THE FAR
SOUTHERN FA BY LATER THIS MORNING AND INTO THE AFTERNOON HOURS.
STRONGEST MESOSCALE FORCING WILL BE SOUTH OF THIS AREA...BUT
CURRENT INDICATIONS SUGGEST AND INCH OR TWO OF SNOW MAY OCCUR
TODAY ACROSS THIS AREA. TO THE NORTH...GIVEN THE DRY LOW LEVEL
AIRMASS IN PLACE AND WEAKER FORCING WENT WITH A DRY FORECAST
(EXCEPT THE CANDO AREA FOR THIS MORNING WHERE RADAR INDICATES A
STRONGER AREA OF PRECIP MAY PROVIDE FLURRIES OR VERY LIGHT SNOW
FOR A BRIEF TIME).
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM CDT SUN MAR 22 2015
SNOW CHANCES AND AMOUNTS WILL BE THE CHALLENGE. 00Z MODELS IN
DECENT AGREEMENT...ALTHOUGH THERE ARE SOME DIFFERENCES TODAY.
RIDGING REMAINS IN PLACE ACROSS THE REGION WITH DRY LOW LEVEL
EASTERLY FLOW. MODEL TRENDS INDICATE LESS INTERACTION BETWEEN NORTHERN
AND SOUTHERN UPPER WAVES...LEADING TO FAR LESS QPF ACROSS THE
WESTERN FA TODAY. IN FACT...THE LATEST HRRR AND RAP GUIDANCE
INDICATES THAT QPF WILL REMAIN OUTSIDE OF THE FA WITH STRONGER
RIDGING/MORE DRY AIR. TRENDED THE FORECAST IN THIS
DIRECTION...WITH MAYBE AN INCH OR TWO OF SNOW ACROSS THE FAR
SOUTHERN FA. WILL CONTINUE TO MONITOR TRENDS AND MAY EVENTUALLY
REMOVE ALL POPS FOR TODAY. WITH THIS...MODELS ARE TRENDING WARMER
TODAY (THINNER CLOUD COVER)...AND FOLLOWED THIS TREND IN THE
FORECAST.
TONIGHT...THE NORTHERN UPPER WAVE IS QUITE STRONG...AND MODELS
HAVE BEEN CONSISTENT SPREADING SNOW INTO PARTS OF THE NORTHERN FA
(WITH AN INCH OR TWO POSSIBLE).
MONDAY...REGION WILL BE BETWEEN SYSTEMS ALONG WITH WARM AIR
ADVECTION AHEAD OF THE NEXT SYSTEM. SHOULD BE A RELATIVELY QUIET
DAY WITH MAX TEMPS APPROACHING OR INTO THE 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM CDT SUN MAR 22 2015
MONDAY NIGHT-TUESDAY NIGHT...STRONGER SYSTEM WILL AFFECT THE
REGION...MOST LIKELY LATER TUESDAY INTO TUESDAY NIGHT. CONFIDENCE
IS HIGH THAT SOMETHING IS GOING TO OCCUR...ALTHOUGH MODELS ARE
ALL OVER THE PLACE WITH DETAILS SO EXACTLY WHAT OCCURS IS HIGHLY
QUESTIONABLE. GENERALLY...THE REGION WILL BE WITHIN AN INVERTED
TROUGH WITH RAIN EVENTUALLY CHANGING TO SNOW. SOME MODELS ARE
INDICATING OVER A FOOT OF SNOW...WITH OTHERS FAR LESS (OR ALMOST
NOTHING). MUCH WILL DEPEND ON HOW THE SYSTEM EVOLVES...AND
WHEN/WHERE THE SOUTHERN SFC LOW STRENGTHENS (WHICH WILL INFLUENCE
THE STRENGTH OF THE INVERTED TROUGH AND THUS QPF AMOUNTS). FOR
NOW...THE BEST THING TO SAY IS RAIN CHANGING TO SNOW WITH SOME
ACCUMULATIONS POSSIBLE.
WEDNESDAY-SATURDAY...THE BACKSIDE OF THE FULLY DEVELOPED CLOSED-
LOW SYSTEM OVER WISCONSIN AND MOVING EASTWARD WILL BRING AN END TO
THE PRECIPITATION OVER WEST-CENTRAL MINNESOTA WITH THE NORTHERLY
WINDS ADVECTING IN SOME COOLER DAYTIME TEMPERATURES IN THE 30S AND
LOWS IN THE TEENS FOR WEDNESDAY. A SURFACE HIGH PRESSURE SYSTEM
WILL BE IN PLACE OVER THE AREA BY THURSDAY AHEAD OF A BUILDING
UPPER-AIR RIDGE ON THE WEST COAST. THAT HIGH WILL BE SHIFTING TO
THE EAST WITH SOME SOUTHERLY WINDS ON ITS BACKSIDE BRINGING IN
SOME WARMER AIR FOR FRIDAY AND SATURDAY. HOWEVER...AN EMBEDDED
UPPER-AIR SHORT WAVE EMBEDDED IN THE NORTHWEST FLOW FROM WESTERN
RIDGE WILL BRING GOOD CHANCES FOR WEEKEND PRECIPITATION AS ANOTHER
SURFACE LOW SPINS UP TO TRAVERSE THE REGION OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1237 PM CDT SUN MAR 22 2015
SFC RIDGE AXIS CURRENTLY LIES ACROSS PORTIONS OF WRN MINNESOTA...AND
IS EXPECTED TO SLOWLY DRIFT E THRU THE PERIOD. SFC DEW POINTS DRY
WITH VALUES IN THE SINGLE DIGITS ACROSS MOST OF THE AREA...WITH THE
DRY AIR EXTENDING UP THRU AROUND 8-10 KFT. THE DRY LOW LEVELS WILL
PERSIST THRU TODAY AND TONIGHT. HOWEVER...A WEAK UPPER LEVEL
DISTURBANCE IS EXPECTED TO CROSS THE NRN PART OF THE AREA OVERNIGHT
STARTING AROUND THE 08-12Z TIME FRAME...WITH INCREASED MOISTURE AND
A CHANCE FOR MVFR CIGS AND -SN MAINLY AT DVL...GFK AND TVF.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...TG
LONG TERM...TG/LUKES
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1053 AM CDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 1053 AM CDT SUN MAR 22 2015
MAIN UPDATE TO END THE FREEZING RAIN ADVISORY SOUTHWEST. ICY ROADS
WILL LINGER THERE UNTIL TEMPERATURES RISE ABOVE FREEZING. ALSO
INCREASED CHANCES OF LIGHT SNOW FAR SOUTHWEST FOR THE AFTERNOON
HOURS. UPDATED HOURLY TEMPERATURE TRENDS. UPDATED FORECASTS WILL
BE ISSUED SHORTLY.
UPDATE ISSUED AT 940 AM CDT SUN MAR 22 2015
MAIN CONCERN IS PRECIPITATION TYPE ACROSS THE SOUTHWEST AND SOUTH
CENTRAL. FEW OBSERVATION POINTS THIS AREA. RADAR ECHOES HAD EXPANDED
FROM GRANT AND SIOUX COUNTY INTO EMMONS/LOGAN/MCINTOSH COUNTIES AND
FEAR WAS THAT FREEZING RAIN MIGHT BE OCCURRING THERE. BRIGHT BAND OF
REFLECTIVITY FROM HETTINGER TO SOUTHERN GRANT INTO SIOUX COUNTY INTO
LOGAN/MCINTOSH...WITH RADAR SUGGESTING SLEET. REPORTS WEST IN SLOPE
COUNTY AND HETTINGER WERE FREEZING RAIN...JUST RECENTLY GOT REPORTS
OF SNOW NEAR THE CORNER OF EMMONS/LOGAN/MCINTOSH COUNTY. THUS
APPEARS FREEZING RAIN WAS CHANGING TO SNOW EAST OF THE MISSOURI
RIVER. MAIN BAND OF PRECIPITATION WAS MOVING SOUTH AND EAST...AND BY
11 AM CDT/10 AM MDT THE BULK OF PRECIPITATION SHOULD BE SOUTH AND
EAST OF OUR AREA. THUS WILL KEEP THE FREEZING RAIN ADVISORY GOING
FOR SOUTHWESTERN NORTH DAKOTA UNTIL SAID TIME.
OTHER CHANGE WAS THAT SURFACE TEMPERATURES IN THE SOUTHWEST WERE NOT
RISING AS QUICKLY AS FORECAST. HOWEVER EXPECT RISING TEMPERATURES TO
COMMENCE WITHIN AN HOUR OR TWO AND BEGIN RISING INTO THE 40S BY LATE
MORNING...AS WINDS IN THE FAR WEST BECOME SOUTH AND THEN TURN WEST
BRINGING WARMER AIR INTO THE REGION.
UPDATE ISSUED AT 705 AM CDT SUN MAR 22 2015
MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST BY BLENDING IN CURRENT
CONDITIONS. AREA RADARS STILL SHOW LIGHT PRECIPITATION MOVING
ACROSS WESTERN AND CENTRAL NORTH DAKOTA...WITH THE LATEST MESO-
SCALE MODELS FOCUSING MOST OF THEIR ATTENTION ON THE PRECIPITATION
ACROSS SOUTHERN NORTH DAKOTA. THE FREEZING RAIN ADVISORY STILL
LOOKS WELL PLACED AND WILL LEAVE AS IS.
UPDATE
ISSUED AT 512 AM CDT SUN MAR 22 2015
QUICK UPDATE TO ISSUE A FREEZING RAIN ADVISORY FOR THE SOUTHWEST
CORNER. JUST HAD A REPORT OF ICY CONDITIONS NEAR HEBRON ON I94
WITH AN ACCIDENT AND SEMI TRUCKS STRUGGLING TO DRIVE UP HILLS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM CDT SUN MAR 22 2015
FORECAST HIGHLIGHTS AND CHALLENGES IN THE SHORT TERM PERIOD WILL
BE THE THREAT FOR FREEZING PRECIPITATION ACROSS THE SOUTHWEST THIS
MORNING...AND HOW PRECIPITATION EVOLVES EASTWARD.
CURRENTLY...ACTIVE ZONAL FLOW ALOFT WITH A POTENT SHORT WAVE
MOVING EAST INTO SOUTH CENTRAL CANADA AND ANOTHER MORE
SUBTLE/EMBEDDED FEATURE MOVING EAST ACROSS NORTHERN
WYOMING/SOUTHEASTERN MONTANA. ASSOCIATED SURFACE LOWS OVER
SOUTHERN SASKATCHEWAN AND EASTERN WY/SOUTHWESTERN SD RESPECTIVELY.
THE SOUTHERN MOST WAVE IS OUR MAIN CONCERN...GENERATING
PRECIPITATION FROM SOUTHEASTERN MONTANA EAST TO ACROSS
SOUTHWESTERN NORTH DAKOTA. THERMAL PROFILES AND SFC TEMPERATURES
INDICATING LIGHT FREEZING RAIN IS LIKELY FALLING. MADE A FEW CALLS
TO THE SOUTHWEST WHICH INDICATED NO IMPACTS AS SO FAR THE LIGHT
FREEZING PRECIP IS ONLY TRACING OUT. A VERY DRY EASTERLY FLOW IS
KEEPING THE BOUNDARY LAYER RATHER DRY FROM THE SURFACE UP TO 5-7K
FT AGL...SO ANY MOISTURE REACHING THE GROUND SHOULD BE LIMITED.
WILL MAINTAIN LIKELY POPS SOUTHWEST INTO SOUTH CENTRAL. HAVE A
SPECIAL WEATHER STATEMENT OUT NOW FOR THE FREEZING RAIN
POTENTIAL...AND WILL CONTINUE WITH THIS UNLESS WE HEAR OF MORE
IMPACTS AND A FREEZING RAIN ADVISORY BECOMES NEEDED. MORE RADAR
RETURNS ACROSS THE NORTH...BUT AGAIN WITH CLOUD BASES AT ROUGHLY
8-10K AGL...ANTICIPATE LITTLE IS REACHING THE GROUND SO WILL KEEP
POPS BELOW LIKELY THERE.
MODELS HAVING A HARD TIME THIS MORNING WITH EACH RUN OF THE HRRR
AND NAM MODELS DIFFERENT. BASICALLY WENT WITH A BLEND WHICH
FOLLOWS THE 00Z ECMWF AND LATEST 06Z NAM RATHER WELL. THIS
CONFINES HIGHER POPS THIS MORNING TO MY SOUTHERN COUNTIES...ALONG
TO SOUTH OF INTERSTATE 94. MAIN THREAT FOR FREEZING RAIN WILL
REMAIN WEST OF THE MISSOURI RIVER ACROSS MY SOUTHWEST THROUGH MID
MORNING...WITH THERMAL PROFILES SUGGESTING ALL SNOW TO THE EAST.
SURFACE FRONTAL BOUNDARY MOMENTARILY STALLS ACROSS THE WEST THIS
AFTERNOON...WITH A WESTERLY WIND TO THE WEST AND SOUTHERLY WIND
TO THE EAST. NAM AND RAP ARE INDICATING POSSIBLE STRATUS
DEVELOPMENT ALONG TO EAST OF THE BOUNDARY LATER TODAY INTO THIS
EVENING AS THE SOUTH/SOUTHEASTERLY FLOW TRANSPORTS MOISTURE NORTH.
THUS WILL KEEP SKY COVER ELEVATED ABOVE MOSTLY SUNNY/MOSTLY CLEAR.
CONFIDENCE NOT HIGH WITH THIS PLAYING OUT WITH MODELS STRUGGLING
THE PAST FEW RUNS.
AFOREMENTIONED STRONG SHORT WAVE CUTTING EAST ACROSS SOUTH CENTRAL
CANADA WILL TURN SOUTHEAST AND MOVE INTO FAR NORTHEASTERN
ND/NORTHERN MINNESOTA THIS SUNDAY NIGHT. PRECIPITATION IN THE FORM
OF SNOW MAY GRAZE MY FAR NORTHEAST SO WILL MAINTAIN A LOW POP THERE
TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM CDT SUN MAR 22 2015
THE PRIMARY CONCERN IN THE LONG TERM PERIOD WILL BE THE POTENT
STORM MONDAY NIGHT INTO TUESDAY. THE LATEST MODEL SUITE CONTINUES
TO ADVERTISE A POTENT STORM SYSTEM ACROSS THE NORTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. DETAILS REGARDING THE EXACT TRACK OF
THE SYSTEM REMAIN ELUSIVE WITH THE 00Z GFS AND ECMWF STILL SHOWING
DIFFERENCES...AND LARGE SPREAD INDICATED BY THE GEFS.
THE ECMWF AND GFS BOTH SUGGEST TWO SURFACE LOWS WILL
DEVELOP...HOWEVER THEY DIFFER ON THE PROGRESSION OF THE NORTHERN
MOST LOW. THE ECMWF KEEPS THE LOWS SEPARATE WITH ONE TRACKING INTO
CANADA...WHILE THE GFS MERGES THE LOWS IN MINNESOTA / WISCONSIN.
HAVE AGAIN GONE WITH A BLENDED MODEL SOLUTION DUE TO THE
UNCERTAINTY. THIS MAINTAINS SOME CONSISTENCY IN THE FORECAST WITH
WARM AIR AND RAIN EXPECTED ACROSS MUCH OF CENTRAL AND WESTERN
NORTH DAKOTA DURING THE MORNING AND AFTERNOON TUESDAY. THE
EXCEPTION COULD BE THE FAR NORTH AND WEST WHERE COLDER AIR MAY
FAVOR SNOW. COLD AIR ARRIVES BEHIND THE LOW TUESDAY NIGHT...WHICH
SUPPORTS A THERMAL PROFILE TRANSITIONING TO SNOW ACROSS THE
FORECAST AREA. CONFIDENCE IN PRECIPITATION AND / OR SNOW AMOUNTS
REMAINS LOW DUE TO THE LARGE DIFFERENCES IN MODEL SOLUTIONS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 705 AM CDT SUN MAR 22 2015
FREEZING RAIN EXPECTED THROUGH 12-14Z FOR KDIK...ALL SNOW EAST FOR
KMOT-KBIS-KJMS WITH NO VISIBILITY RESTRICTIONS EXPECTED. IFR
CONDITIONS POSSIBLE FOR KBIS-KJMS IF SNOW DEVELOPS MORE THAN
EXPECTED LATER THIS MORNING. MODELS STILL INDICATE A CORRIDOR OF LOW
STRATUS DEVELOPING DURING THE AFTERNOON INTO SUNDAY NIGHT CENTRAL
IMPACTING KBIS-KMOT-KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 11 AM CDT /10 AM MDT/ THIS MORNING
FOR NDZ033-034-040>045.
&&
$$
UPDATE...JV
SHORT TERM...NH
LONG TERM...CK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1001 AM CDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 1001 AM CDT SUN MAR 22 2015
BAND OF PRECIP CONTINUES TO MOVE EASTWARD TOWARDS OUR SOUTHWESTERN
COUNTIES. HOWEVER...WEB CAMS NEAR WISHEK WHICH HAS HAD RADAR
RETURNS MOVING OVERHEAD FOR THE LAST FEW HOURS SHOW THAT NOT MUCH
IS REACHING THE GROUND SO FAR. MODEL SOUNDINGS CONTINUE TO SHOW A
DRY LAYER NEAR THE SFC WHICH DOES NOT REALLY SATURATE UNTIL WELL
INTO THE AFTERNOON HOURS. CONTINUED TO KEEP SOME LIKELY POPS IN
THE FAR SOUTHERN COUNTIES FOR THIS AFTERNOON AS WE WILL NOT SEE
MUCH BEFORE THEN...BUT WILL HAVE TO WATCH TO SEE HOW THE BATTLE
BETWEEN DRY AIR AND FRONTOGENESIS UNFOLDS AND MAKE ADJUSTMENTS AS
NEEDED.
UPDATE ISSUED AT 650 AM CDT SUN MAR 22 2015
BAND OF PRECIP IS SETTING UP ACROSS SOUTHERN NORTH DAKOTA...AND
LATEST HI-RES GUIDANCE INDICATES THIS BAND WILL AFFECT THE FAR
SOUTHERN FA BY LATER THIS MORNING AND INTO THE AFTERNOON HOURS.
STRONGEST MESOSCALE FORCING WILL BE SOUTH OF THIS AREA...BUT
CURRENT INDICATIONS SUGGEST AND INCH OR TWO OF SNOW MAY OCCUR
TODAY ACROSS THIS AREA. TO THE NORTH...GIVEN THE DRY LOW LEVEL
AIRMASS IN PLACE AND WEAKER FORCING WENT WITH A DRY FORECAST
(EXCEPT THE CANDO AREA FOR THIS MORNING WHERE RADAR INDICATES A
STRONGER AREA OF PRECIP MAY PROVIDE FLURRIES OR VERY LIGHT SNOW
FOR A BRIEF TIME).
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM CDT SUN MAR 22 2015
SNOW CHANCES AND AMOUNTS WILL BE THE CHALLENGE. 00Z MODELS IN
DECENT AGREEMENT...ALTHOUGH THERE ARE SOME DIFFERENCES TODAY.
RIDGING REMAINS IN PLACE ACROSS THE REGION WITH DRY LOW LEVEL
EASTERLY FLOW. MODEL TRENDS INDICATE LESS INTERACTION BETWEEN NORTHERN
AND SOUTHERN UPPER WAVES...LEADING TO FAR LESS QPF ACROSS THE
WESTERN FA TODAY. IN FACT...THE LATEST HRRR AND RAP GUIDANCE
INDICATES THAT QPF WILL REMAIN OUTSIDE OF THE FA WITH STRONGER
RIDGING/MORE DRY AIR. TRENDED THE FORECAST IN THIS
DIRECTION...WITH MAYBE AN INCH OR TWO OF SNOW ACROSS THE FAR
SOUTHERN FA. WILL CONTINUE TO MONITOR TRENDS AND MAY EVENTUALLY
REMOVE ALL POPS FOR TODAY. WITH THIS...MODELS ARE TRENDING WARMER
TODAY (THINNER CLOUD COVER)...AND FOLLOWED THIS TREND IN THE
FORECAST.
TONIGHT...THE NORTHERN UPPER WAVE IS QUITE STRONG...AND MODELS
HAVE BEEN CONSISTENT SPREADING SNOW INTO PARTS OF THE NORTHERN FA
(WITH AN INCH OR TWO POSSIBLE).
MONDAY...REGION WILL BE BETWEEN SYSTEMS ALONG WITH WARM AIR
ADVECTION AHEAD OF THE NEXT SYSTEM. SHOULD BE A RELATIVELY QUIET
DAY WITH MAX TEMPS APPROACHING OR INTO THE 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM CDT SUN MAR 22 2015
MONDAY NIGHT-TUESDAY NIGHT...STRONGER SYSTEM WILL AFFECT THE
REGION...MOST LIKELY LATER TUESDAY INTO TUESDAY NIGHT. CONFIDENCE
IS HIGH THAT SOMETHING IS GOING TO OCCUR...ALTHOUGH MODELS ARE
ALL OVER THE PLACE WITH DETAILS SO EXACTLY WHAT OCCURS IS HIGHLY
QUESTIONABLE. GENERALLY...THE REGION WILL BE WITHIN AN INVERTED
TROUGH WITH RAIN EVENTUALLY CHANGING TO SNOW. SOME MODELS ARE
INDICATING OVER A FOOT OF SNOW...WITH OTHERS FAR LESS (OR ALMOST
NOTHING). MUCH WILL DEPEND ON HOW THE SYSTEM EVOLVES...AND
WHEN/WHERE THE SOUTHERN SFC LOW STRENGTHENS (WHICH WILL INFLUENCE
THE STRENGTH OF THE INVERTED TROUGH AND THUS QPF AMOUNTS). FOR
NOW...THE BEST THING TO SAY IS RAIN CHANGING TO SNOW WITH SOME
ACCUMULATIONS POSSIBLE.
WEDNESDAY-SATURDAY...THE BACKSIDE OF THE FULLY DEVELOPED CLOSED-
LOW SYSTEM OVER WISCONSIN AND MOVING EASTWARD WILL BRING AN END TO
THE PRECIPITATION OVER WEST-CENTRAL MINNESOTA WITH THE NORTHERLY
WINDS ADVECTING IN SOME COOLER DAYTIME TEMPERATURES IN THE 30S AND
LOWS IN THE TEENS FOR WEDNESDAY. A SURFACE HIGH PRESSURE SYSTEM
WILL BE IN PLACE OVER THE AREA BY THURSDAY AHEAD OF A BUILDING
UPPER-AIR RIDGE ON THE WEST COAST. THAT HIGH WILL BE SHIFTING TO
THE EAST WITH SOME SOUTHERLY WINDS ON ITS BACKSIDE BRINGING IN
SOME WARMER AIR FOR FRIDAY AND SATURDAY. HOWEVER...AN EMBEDDED
UPPER-AIR SHORT WAVE EMBEDDED IN THE NORTHWEST FLOW FROM WESTERN
RIDGE WILL BRING GOOD CHANCES FOR WEEKEND PRECIPITATION AS ANOTHER
SURFACE LOW SPINS UP TO TRAVERSE THE REGION OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM CDT SUN MAR 22 2015
DRY LOW LEVEL AIRMASS WILL REMAIN IN PLACE TODAY...LEADING TO VFR
CIGS. ANTICIPATE THESE CONDITIONS WILL CONTINUE INTO THE OVERNIGHT
HOURS...WITH ANY -SN CHANCES REMAINING AWAY FROM THE TAF SITES
(TO THE SOUTH TODAY...AND TO THE NORTH TONIGHT).
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...TG
LONG TERM...TG/LUKES
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
940 AM CDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 940 AM CDT SUN MAR 22 2015
MAIN CONCERN IS PRECIPITATION TYPE ACROSS THE SOUTHWEST AND SOUTH
CENTRAL. FEW OBSERVATION POINTS THIS AREA. RADAR ECHOES HAD EXPANDED
FROM GRANT AND SIOUX COUNTY INTO EMMONS/LOGAN/MCINTOSH COUNTIES AND
FEAR WAS THAT FREEZING RAIN MIGHT BE OCCURRING THERE. BRIGHT BAND OF
REFLECTIVITY FROM HETTINGER TO SOUTHERN GRANT INTO SIOUX COUNTY INTO
LOGAN/MCINTOSH...WITH RADAR SUGGESTING SLEET. REPORTS WEST IN SLOPE
COUNTY AND HETTINGER WERE FREEZING RAIN...JUST RECENTLY GOT REPORTS
OF SNOW NEAR THE CORNER OF EMMONS/LOGAN/MCINTOSH COUNTY. THUS
APPEARS FREEZING RAIN WAS CHANGING TO SNOW EAST OF THE MISSOURI
RIVER. MAIN BAND OF PRECIPITATION WAS MOVING SOUTH AND EAST...AND BY
11 AM CDT/10 AM MDT THE BULK OF PRECIPITATION SHOULD BE SOUTH AND
EAST OF OUR AREA. THUS WILL KEEP THE FREEZING RAIN ADVISORY GOING
FOR SOUTHWESTERN NORTH DAKOTA UNTIL SAID TIME.
OTHER CHANGE WAS THAT SURFACE TEMPERATURES IN THE SOUTHWEST WERE NOT
RISING AS QUICKLY AS FORECAST. HOWEVER EXPECT RISING TEMPERATURES TO
COMMENCE WITHIN AN HOUR OR TWO AND BEGIN RISING INTO THE 40S BY LATE
MORNING...AS WINDS IN THE FAR WEST BECOME SOUTH AND THEN TURN WEST
BRINGING WARMER AIR INTO THE REGION.
UPDATE ISSUED AT 705 AM CDT SUN MAR 22 2015
MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST BY BLENDING IN CURRENT
CONDITIONS. AREA RADARS STILL SHOW LIGHT PRECIPITATION MOVING
ACROSS WESTERN AND CENTRAL NORTH DAKOTA...WITH THE LATEST MESO-
SCALE MODELS FOCUSING MOST OF THEIR ATTENTION ON THE PRECIPITATION
ACROSS SOUTHERN NORTH DAKOTA. THE FREEZING RAIN ADVISORY STILL
LOOKS WELL PLACED AND WILL LEAVE AS IS.
UPDATE
ISSUED AT 512 AM CDT SUN MAR 22 2015
QUICK UPDATE TO ISSUE A FREEZING RAIN ADVISORY FOR THE SOUTHWEST
CORNER. JUST HAD A REPORT OF ICY CONDITIONS NEAR HEBRON ON I94
WITH AN ACCIDENT AND SEMI TRUCKS STRUGGLING TO DRIVE UP HILLS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM CDT SUN MAR 22 2015
FORECAST HIGHLIGHTS AND CHALLENGES IN THE SHORT TERM PERIOD WILL
BE THE THREAT FOR FREEZING PRECIPITATION ACROSS THE SOUTHWEST THIS
MORNING...AND HOW PRECIPITATION EVOLVES EASTWARD.
CURRENTLY...ACTIVE ZONAL FLOW ALOFT WITH A POTENT SHORT WAVE
MOVING EAST INTO SOUTH CENTRAL CANADA AND ANOTHER MORE
SUBTLE/EMBEDDED FEATURE MOVING EAST ACROSS NORTHERN
WYOMING/SOUTHEASTERN MONTANA. ASSOCIATED SURFACE LOWS OVER
SOUTHERN SASKATCHEWAN AND EASTERN WY/SOUTHWESTERN SD RESPECTIVELY.
THE SOUTHERN MOST WAVE IS OUR MAIN CONCERN...GENERATING
PRECIPITATION FROM SOUTHEASTERN MONTANA EAST TO ACROSS
SOUTHWESTERN NORTH DAKOTA. THERMAL PROFILES AND SFC TEMPERATURES
INDICATING LIGHT FREEZING RAIN IS LIKELY FALLING. MADE A FEW CALLS
TO THE SOUTHWEST WHICH INDICATED NO IMPACTS AS SO FAR THE LIGHT
FREEZING PRECIP IS ONLY TRACING OUT. A VERY DRY EASTERLY FLOW IS
KEEPING THE BOUNDARY LAYER RATHER DRY FROM THE SURFACE UP TO 5-7K
FT AGL...SO ANY MOISTURE REACHING THE GROUND SHOULD BE LIMITED.
WILL MAINTAIN LIKELY POPS SOUTHWEST INTO SOUTH CENTRAL. HAVE A
SPECIAL WEATHER STATEMENT OUT NOW FOR THE FREEZING RAIN
POTENTIAL...AND WILL CONTINUE WITH THIS UNLESS WE HEAR OF MORE
IMPACTS AND A FREEZING RAIN ADVISORY BECOMES NEEDED. MORE RADAR
RETURNS ACROSS THE NORTH...BUT AGAIN WITH CLOUD BASES AT ROUGHLY
8-10K AGL...ANTICIPATE LITTLE IS REACHING THE GROUND SO WILL KEEP
POPS BELOW LIKELY THERE.
MODELS HAVING A HARD TIME THIS MORNING WITH EACH RUN OF THE HRRR
AND NAM MODELS DIFFERENT. BASICALLY WENT WITH A BLEND WHICH
FOLLOWS THE 00Z ECMWF AND LATEST 06Z NAM RATHER WELL. THIS
CONFINES HIGHER POPS THIS MORNING TO MY SOUTHERN COUNTIES...ALONG
TO SOUTH OF INTERSTATE 94. MAIN THREAT FOR FREEZING RAIN WILL
REMAIN WEST OF THE MISSOURI RIVER ACROSS MY SOUTHWEST THROUGH MID
MORNING...WITH THERMAL PROFILES SUGGESTING ALL SNOW TO THE EAST.
SURFACE FRONTAL BOUNDARY MOMENTARILY STALLS ACROSS THE WEST THIS
AFTERNOON...WITH A WESTERLY WIND TO THE WEST AND SOUTHERLY WIND
TO THE EAST. NAM AND RAP ARE INDICATING POSSIBLE STRATUS
DEVELOPMENT ALONG TO EAST OF THE BOUNDARY LATER TODAY INTO THIS
EVENING AS THE SOUTH/SOUTHEASTERLY FLOW TRANSPORTS MOISTURE NORTH.
THUS WILL KEEP SKY COVER ELEVATED ABOVE MOSTLY SUNNY/MOSTLY CLEAR.
CONFIDENCE NOT HIGH WITH THIS PLAYING OUT WITH MODELS STRUGGLING
THE PAST FEW RUNS.
AFOREMENTIONED STRONG SHORT WAVE CUTTING EAST ACROSS SOUTH CENTRAL
CANADA WILL TURN SOUTHEAST AND MOVE INTO FAR NORTHEASTERN
ND/NORTHERN MINNESOTA THIS SUNDAY NIGHT. PRECIPITATION IN THE FORM
OF SNOW MAY GRAZE MY FAR NORTHEAST SO WILL MAINTAIN A LOW POP THERE
TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM CDT SUN MAR 22 2015
THE PRIMARY CONCERN IN THE LONG TERM PERIOD WILL BE THE POTENT
STORM MONDAY NIGHT INTO TUESDAY. THE LATEST MODEL SUITE CONTINUES
TO ADVERTISE A POTENT STORM SYSTEM ACROSS THE NORTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. DETAILS REGARDING THE EXACT TRACK OF
THE SYSTEM REMAIN ELUSIVE WITH THE 00Z GFS AND ECMWF STILL SHOWING
DIFFERENCES...AND LARGE SPREAD INDICATED BY THE GEFS.
THE ECMWF AND GFS BOTH SUGGEST TWO SURFACE LOWS WILL
DEVELOP...HOWEVER THEY DIFFER ON THE PROGRESSION OF THE NORTHERN
MOST LOW. THE ECMWF KEEPS THE LOWS SEPARATE WITH ONE TRACKING INTO
CANADA...WHILE THE GFS MERGES THE LOWS IN MINNESOTA / WISCONSIN.
HAVE AGAIN GONE WITH A BLENDED MODEL SOLUTION DUE TO THE
UNCERTAINTY. THIS MAINTAINS SOME CONSISTENCY IN THE FORECAST WITH
WARM AIR AND RAIN EXPECTED ACROSS MUCH OF CENTRAL AND WESTERN
NORTH DAKOTA DURING THE MORNING AND AFTERNOON TUESDAY. THE
EXCEPTION COULD BE THE FAR NORTH AND WEST WHERE COLDER AIR MAY
FAVOR SNOW. COLD AIR ARRIVES BEHIND THE LOW TUESDAY NIGHT...WHICH
SUPPORTS A THERMAL PROFILE TRANSITIONING TO SNOW ACROSS THE
FORECAST AREA. CONFIDENCE IN PRECIPITATION AND / OR SNOW AMOUNTS
REMAINS LOW DUE TO THE LARGE DIFFERENCES IN MODEL SOLUTIONS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 705 AM CDT SUN MAR 22 2015
FREEZING RAIN EXPECTED THROUGH 12-14Z FOR KDIK...ALL SNOW EAST FOR
KMOT-KBIS-KJMS WITH NO VISIBILITY RESTRICTIONS EXPECTED. IFR
CONDITIONS POSSIBLE FOR KBIS-KJMS IF SNOW DEVELOPS MORE THAN
EXPECTED LATER THIS MORNING. MODELS STILL INDICATE A CORRIDOR OF LOW
STRATUS DEVELOPING DURING THE AFTERNOON INTO SUNDAY NIGHT CENTRAL
IMPACTING KBIS-KMOT-KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 11 AM CDT /10 AM MDT/ THIS MORNING
FOR NDZ033-034-040>045.
&&
$$
UPDATE...JV
SHORT TERM...NH
LONG TERM...CK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
708 AM CDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 705 AM CDT SUN MAR 22 2015
MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST BY BLENDING IN CURRENT
CONDITIONS. AREA RADARS STILL SHOW LIGHT PRECIPITATION MOVING
ACROSS WESTERN AND CENTRAL NORTH DAKOTA...WITH THE LATEST MESO-
SCALE MODELS FOCUSING MOST OF THEIR ATTENTION ON THE PRECIPITATION
ACROSS SOUTHERN NORTH DAKOTA. THE FREEZING RAIN ADVISORY STILL
LOOKS WELL PLACED AND WILL LEAVE AS IS.
UPDATE
ISSUED AT 512 AM CDT SUN MAR 22 2015
QUICK UPDATE TO ISSUE A FREEZING RAIN ADVISORY FOR THE SOUTHWEST
CORNER. JUST HAD A REPORT OF ICY CONDITIONS NEAR HEBRON ON I94
WITH AN ACCIDENT AND SEMI TRUCKS STRUGGLING TO DRIVE UP HILLS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM CDT SUN MAR 22 2015
FORECAST HIGHLIGHTS AND CHALLENGES IN THE SHORT TERM PERIOD WILL
BE THE THREAT FOR FREEZING PRECIPITATION ACROSS THE SOUTHWEST THIS
MORNING...AND HOW PRECIPITATION EVOLVES EASTWARD.
CURRENTLY...ACTIVE ZONAL FLOW ALOFT WITH A POTENT SHORT WAVE
MOVING EAST INTO SOUTH CENTRAL CANADA AND ANOTHER MORE
SUBTLE/EMBEDDED FEATURE MOVING EAST ACROSS NORTHERN
WYOMING/SOUTHEASTERN MONTANA. ASSOCIATED SURFACE LOWS OVER
SOUTHERN SASKATCHEWAN AND EASTERN WY/SOUTHWESTERN SD RESPECTIVELY.
THE SOUTHERN MOST WAVE IS OUR MAIN CONCERN...GENERATING
PRECIPITATION FROM SOUTHEASTERN MONTANA EAST TO ACROSS
SOUTHWESTERN NORTH DAKOTA. THERMAL PROFILES AND SFC TEMPERATURES
INDICATING LIGHT FREEZING RAIN IS LIKELY FALLING. MADE A FEW CALLS
TO THE SOUTHWEST WHICH INDICATED NO IMPACTS AS SO FAR THE LIGHT
FREEZING PRECIP IS ONLY TRACING OUT. A VERY DRY EASTERLY FLOW IS
KEEPING THE BOUNDARY LAYER RATHER DRY FROM THE SURFACE UP TO 5-7K
FT AGL...SO ANY MOISTURE REACHING THE GROUND SHOULD BE LIMITED.
WILL MAINTAIN LIKELY POPS SOUTHWEST INTO SOUTH CENTRAL. HAVE A
SPECIAL WEATHER STATEMENT OUT NOW FOR THE FREEZING RAIN
POTENTIAL...AND WILL CONTINUE WITH THIS UNLESS WE HEAR OF MORE
IMPACTS AND A FREEZING RAIN ADVISORY BECOMES NEEDED. MORE RADAR
RETURNS ACROSS THE NORTH...BUT AGAIN WITH CLOUD BASES AT ROUGHLY
8-10K AGL...ANTICIPATE LITTLE IS REACHING THE GROUND SO WILL KEEP
POPS BELOW LIKELY THERE.
MODELS HAVING A HARD TIME THIS MORNING WITH EACH RUN OF THE HRRR
AND NAM MODELS DIFFERENT. BASICALLY WENT WITH A BLEND WHICH
FOLLOWS THE 00Z ECMWF AND LATEST 06Z NAM RATHER WELL. THIS
CONFINES HIGHER POPS THIS MORNING TO MY SOUTHERN COUNTIES...ALONG
TO SOUTH OF INTERSTATE 94. MAIN THREAT FOR FREEZING RAIN WILL
REMAIN WEST OF THE MISSOURI RIVER ACROSS MY SOUTHWEST THROUGH MID
MORNING...WITH THERMAL PROFILES SUGGESTING ALL SNOW TO THE EAST.
SURFACE FRONTAL BOUNDARY MOMENTARILY STALLS ACROSS THE WEST THIS
AFTERNOON...WITH A WESTERLY WIND TO THE WEST AND SOUTHERLY WIND
TO THE EAST. NAM AND RAP ARE INDICATING POSSIBLE STRATUS
DEVELOPMENT ALONG TO EAST OF THE BOUNDARY LATER TODAY INTO THIS
EVENING AS THE SOUTH/SOUTHEASTERLY FLOW TRANSPORTS MOISTURE NORTH.
THUS WILL KEEP SKY COVER ELEVATED ABOVE MOSTLY SUNNY/MOSTLY CLEAR.
CONFIDENCE NOT HIGH WITH THIS PLAYING OUT WITH MODELS STRUGGLING
THE PAST FEW RUNS.
AFOREMENTIONED STRONG SHORT WAVE CUTTING EAST ACROSS SOUTH CENTRAL
CANADA WILL TURN SOUTHEAST AND MOVE INTO FAR NORTHEASTERN
ND/NORTHERN MINNESOTA THIS SUNDAY NIGHT. PRECIPITATION IN THE FORM
OF SNOW MAY GRAZE MY FAR NORTHEAST SO WILL MAINTAIN A LOW POP THERE
TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM CDT SUN MAR 22 2015
THE PRIMARY CONCERN IN THE LONG TERM PERIOD WILL BE THE POTENT
STORM MONDAY NIGHT INTO TUESDAY. THE LATEST MODEL SUITE CONTINUES
TO ADVERTISE A POTENT STORM SYSTEM ACROSS THE NORTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. DETAILS REGARDING THE EXACT TRACK OF
THE SYSTEM REMAIN ELUSIVE WITH THE 00Z GFS AND ECMWF STILL SHOWING
DIFFERENCES...AND LARGE SPREAD INDICATED BY THE GEFS.
THE ECMWF AND GFS BOTH SUGGEST TWO SURFACE LOWS WILL
DEVELOP...HOWEVER THEY DIFFER ON THE PROGRESSION OF THE NORTHERN
MOST LOW. THE ECMWF KEEPS THE LOWS SEPARATE WITH ONE TRACKING INTO
CANADA...WHILE THE GFS MERGES THE LOWS IN MINNESOTA / WISCONSIN.
HAVE AGAIN GONE WITH A BLENDED MODEL SOLUTION DUE TO THE
UNCERTAINTY. THIS MAINTAINS SOME CONSISTENCY IN THE FORECAST WITH
WARM AIR AND RAIN EXPECTED ACROSS MUCH OF CENTRAL AND WESTERN
NORTH DAKOTA DURING THE MORNING AND AFTERNOON TUESDAY. THE
EXCEPTION COULD BE THE FAR NORTH AND WEST WHERE COLDER AIR MAY
FAVOR SNOW. COLD AIR ARRIVES BEHIND THE LOW TUESDAY NIGHT...WHICH
SUPPORTS A THERMAL PROFILE TRANSITIONING TO SNOW ACROSS THE
FORECAST AREA. CONFIDENCE IN PRECIPITATION AND / OR SNOW AMOUNTS
REMAINS LOW DUE TO THE LARGE DIFFERENCES IN MODEL SOLUTIONS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 705 AM CDT SUN MAR 22 2015
FREEZING RAIN EXPECTED THROUGH 12-14Z FOR KDIK...ALL SNOW EAST FOR
KMOT-KBIS-KJMS WITH NO VISIBILITY RESTRICTIONS EXPECTED. IFR
CONDITIONS POSSIBLE FOR KBIS-KJMS IF SNOW DEVELOPS MORE THAN
EXPECTED LATER THIS MORNING. MODELS STILL INDICATE A CORRIDOR OF LOW
STRATUS DEVELOPING DURING THE AFTERNOON INTO SUNDAY NIGHT CENTRAL
IMPACTING KBIS-KMOT-KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 11 AM CDT /10 AM MDT/ THIS MORNING
FOR NDZ033-034-040>045.
&&
$$
UPDATE...CK
SHORT TERM...NH
LONG TERM...CK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
650 AM CDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 650 AM CDT SUN MAR 22 2015
BAND OF PRECIP IS SETTING UP ACROSS SOUTHERN NORTH DAKOTA...AND
LATEST HI-RES GUIDANCE INDICATES THIS BAND WILL AFFECT THE FAR
SOUTHERN FA BY LATER THIS MORNING AND INTO THE AFTERNOON HOURS.
STRONGEST MESOSCALE FORCING WILL BE SOUTH OF THIS AREA...BUT
CURRENT INDICATIONS SUGGEST AND INCH OR TWO OF SNOW MAY OCCUR
TODAY ACROSS THIS AREA. TO THE NORTH...GIVEN THE DRY LOW LEVEL
AIRMASS IN PLACE AND WEAKER FORCING WENT WITH A DRY FORECAST
(EXCEPT THE CANDO AREA FOR THIS MORNING WHERE RADAR INDICATES A
STRONGER AREA OF PRECIP MAY PROVIDE FLURRIES OR VERY LIGHT SNOW
FOR A BRIEF TIME).
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM CDT SUN MAR 22 2015
SNOW CHANCES AND AMOUNTS WILL BE THE CHALLENGE. 00Z MODELS IN
DECENT AGREEMENT...ALTHOUGH THERE ARE SOME DIFFERENCES TODAY.
RIDGING REMAINS IN PLACE ACROSS THE REGION WITH DRY LOW LEVEL
EASTERLY FLOW. MODEL TRENDS INDICATE LESS INTERACTION BETWEEN NORTHERN
AND SOUTHERN UPPER WAVES...LEADING TO FAR LESS QPF ACROSS THE
WESTERN FA TODAY. IN FACT...THE LATEST HRRR AND RAP GUIDANCE
INDICATES THAT QPF WILL REMAIN OUTSIDE OF THE FA WITH STRONGER
RIDGING/MORE DRY AIR. TRENDED THE FORECAST IN THIS
DIRECTION...WITH MAYBE AN INCH OR TWO OF SNOW ACROSS THE FAR
SOUTHERN FA. WILL CONTINUE TO MONITOR TRENDS AND MAY EVENTUALLY
REMOVE ALL POPS FOR TODAY. WITH THIS...MODELS ARE TRENDING WARMER
TODAY (THINNER CLOUD COVER)...AND FOLLOWED THIS TREND IN THE
FORECAST.
TONIGHT...THE NORTHERN UPPER WAVE IS QUITE STRONG...AND MODELS
HAVE BEEN CONSISTENT SPREADING SNOW INTO PARTS OF THE NORTHERN FA
(WITH AN INCH OR TWO POSSIBLE).
MONDAY...REGION WILL BE BETWEEN SYSTEMS ALONG WITH WARM AIR
ADVECTION AHEAD OF THE NEXT SYSTEM. SHOULD BE A RELATIVELY QUIET
DAY WITH MAX TEMPS APPROACHING OR INTO THE 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM CDT SUN MAR 22 2015
MONDAY NIGHT-TUESDAY NIGHT...STRONGER SYSTEM WILL AFFECT THE
REGION...MOST LIKELY LATER TUESDAY INTO TUESDAY NIGHT. CONFIDENCE
IS HIGH THAT SOMETHING IS GOING TO OCCUR...ALTHOUGH MODELS ARE
ALL OVER THE PLACE WITH DETAILS SO EXACTLY WHAT OCCURS IS HIGHLY
QUESTIONABLE. GENERALLY...THE REGION WILL BE WITHIN AN INVERTED
TROUGH WITH RAIN EVENTUALLY CHANGING TO SNOW. SOME MODELS ARE
INDICATING OVER A FOOT OF SNOW...WITH OTHERS FAR LESS (OR ALMOST
NOTHING). MUCH WILL DEPEND ON HOW THE SYSTEM EVOLVES...AND
WHEN/WHERE THE SOUTHERN SFC LOW STRENGTHENS (WHICH WILL INFLUENCE
THE STRENGTH OF THE INVERTED TROUGH AND THUS QPF AMOUNTS). FOR
NOW...THE BEST THING TO SAY IS RAIN CHANGING TO SNOW WITH SOME
ACCUMULATIONS POSSIBLE.
WEDNESDAY-SATURDAY...THE BACKSIDE OF THE FULLY DEVELOPED CLOSED-
LOW SYSTEM OVER WISCONSIN AND MOVING EASTWARD WILL BRING AN END TO
THE PRECIPITATION OVER WEST-CENTRAL MINNESOTA WITH THE NORTHERLY
WINDS ADVECTING IN SOME COOLER DAYTIME TEMPERATURES IN THE 30S AND
LOWS IN THE TEENS FOR WEDNESDAY. A SURFACE HIGH PRESSURE SYSTEM
WILL BE IN PLACE OVER THE AREA BY THURSDAY AHEAD OF A BUILDING
UPPER-AIR RIDGE ON THE WEST COAST. THAT HIGH WILL BE SHIFTING TO
THE EAST WITH SOME SOUTHERLY WINDS ON ITS BACKSIDE BRINGING IN
SOME WARMER AIR FOR FRIDAY AND SATURDAY. HOWEVER...AN EMBEDDED
UPPER-AIR SHORT WAVE EMBEDDED IN THE NORTHWEST FLOW FROM WESTERN
RIDGE WILL BRING GOOD CHANCES FOR WEEKEND PRECIPITATION AS ANOTHER
SURFACE LOW SPINS UP TO TRAVERSE THE REGION OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM CDT SUN MAR 22 2015
DRY LOW LEVEL AIRMASS WILL REMAIN IN PLACE TODAY...LEADING TO VFR
CIGS. ANTICIPATE THESE CONDITIONS WILL CONTINUE INTO THE OVERNIGHT
HOURS...WITH ANY -SN CHANCES REMAINING AWAY FROM THE TAF SITES
(TO THE SOUTH TODAY...AND TO THE NORTH TONIGHT).
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...TG
LONG TERM...TG/LUKES
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
511 AM CDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 512 AM CDT SUN MAR 22 2015
QUICK UPDATE TO ISSUE A FREEZING RAIN ADVISORY FOR THE SOUTHWEST
CORNER. JUST HAD A REPORT OF ICY CONDITIONS NEAR HEBRON ON I94
WITH AN ACCIDENT AND SEMI TRUCKS STRUGGLING TO DRIVE UP HILLS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM CDT SUN MAR 22 2015
FORECAST HIGHLIGHTS AND CHALLENGES IN THE SHORT TERM PERIOD WILL
BE THE THREAT FOR FREEZING PRECIPITATION ACROSS THE SOUTHWEST THIS
MORNING...AND HOW PRECIPITATION EVOLVES EASTWARD.
CURRENTLY...ACTIVE ZONAL FLOW ALOFT WITH A POTENT SHORT WAVE
MOVING EAST INTO SOUTH CENTRAL CANADA AND ANOTHER MORE
SUBTLE/EMBEDDED FEATURE MOVING EAST ACROSS NORTHERN
WYOMING/SOUTHEASTERN MONTANA. ASSOCIATED SURFACE LOWS OVER
SOUTHERN SASKATCHEWAN AND EASTERN WY/SOUTHWESTERN SD RESPECTIVELY.
THE SOUTHERN MOST WAVE IS OUR MAIN CONCERN...GENERATING
PRECIPITATION FROM SOUTHEASTERN MONTANA EAST TO ACROSS
SOUTHWESTERN NORTH DAKOTA. THERMAL PROFILES AND SFC TEMPERATURES
INDICATING LIGHT FREEZING RAIN IS LIKELY FALLING. MADE A FEW CALLS
TO THE SOUTHWEST WHICH INDICATED NO IMPACTS AS SO FAR THE LIGHT
FREEZING PRECIP IS ONLY TRACING OUT. A VERY DRY EASTERLY FLOW IS
KEEPING THE BOUNDARY LAYER RATHER DRY FROM THE SURFACE UP TO 5-7K
FT AGL...SO ANY MOISTURE REACHING THE GROUND SHOULD BE LIMITED.
WILL MAINTAIN LIKELY POPS SOUTHWEST INTO SOUTH CENTRAL. HAVE A
SPECIAL WEATHER STATEMENT OUT NOW FOR THE FREEZING RAIN
POTENTIAL...AND WILL CONTINUE WITH THIS UNLESS WE HEAR OF MORE
IMPACTS AND A FREEZING RAIN ADVISORY BECOMES NEEDED. MORE RADAR
RETURNS ACROSS THE NORTH...BUT AGAIN WITH CLOUD BASES AT ROUGHLY
8-10K AGL...ANTICIPATE LITTLE IS REACHING THE GROUND SO WILL KEEP
POPS BELOW LIKELY THERE.
MODELS HAVING A HARD TIME THIS MORNING WITH EACH RUN OF THE HRRR
AND NAM MODELS DIFFERENT. BASICALLY WENT WITH A BLEND WHICH
FOLLOWS THE 00Z ECMWF AND LATEST 06Z NAM RATHER WELL. THIS
CONFINES HIGHER POPS THIS MORNING TO MY SOUTHERN COUNTIES...ALONG
TO SOUTH OF INTERSTATE 94. MAIN THREAT FOR FREEZING RAIN WILL
REMAIN WEST OF THE MISSOURI RIVER ACROSS MY SOUTHWEST THROUGH MID
MORNING...WITH THERMAL PROFILES SUGGESTING ALL SNOW TO THE EAST.
SURFACE FRONTAL BOUNDARY MOMENTARILY STALLS ACROSS THE WEST THIS
AFTERNOON...WITH A WESTERLY WIND TO THE WEST AND SOUTHERLY WIND
TO THE EAST. NAM AND RAP ARE INDICATING POSSIBLE STRATUS
DEVELOPMENT ALONG TO EAST OF THE BOUNDARY LATER TODAY INTO THIS
EVENING AS THE SOUTH/SOUTHEASTERLY FLOW TRANSPORTS MOISTURE NORTH.
THUS WILL KEEP SKY COVER ELEVATED ABOVE MOSTLY SUNNY/MOSTLY CLEAR.
CONFIDENCE NOT HIGH WITH THIS PLAYING OUT WITH MODELS STRUGGLING
THE PAST FEW RUNS.
AFOREMENTIONED STRONG SHORT WAVE CUTTING EAST ACROSS SOUTH CENTRAL
CANADA WILL TURN SOUTHEAST AND MOVE INTO FAR NORTHEASTERN
ND/NORTHERN MINNESOTA THIS SUNDAY NIGHT. PRECIPITATION IN THE FORM
OF SNOW MAY GRAZE MY FAR NORTHEAST SO WILL MAINTAIN A LOW POP THERE
TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM CDT SUN MAR 22 2015
THE PRIMARY CONCERN IN THE LONG TERM PERIOD WILL BE THE POTENT
STORM MONDAY NIGHT INTO TUESDAY. THE LATEST MODEL SUITE CONTINUES
TO ADVERTISE A POTENT STORM SYSTEM ACROSS THE NORTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. DETAILS REGARDING THE EXACT TRACK OF
THE SYSTEM REMAIN ELUSIVE WITH THE 00Z GFS AND ECMWF STILL SHOWING
DIFFERENCES...AND LARGE SPREAD INDICATED BY THE GEFS.
THE ECMWF AND GFS BOTH SUGGEST TWO SURFACE LOWS WILL
DEVELOP...HOWEVER THEY DIFFER ON THE PROGRESSION OF THE NORTHERN
MOST LOW. THE ECMWF KEEPS THE LOWS SEPARATE WITH ONE TRACKING INTO
CANADA...WHILE THE GFS MERGES THE LOWS IN MINNESOTA / WISCONSIN.
HAVE AGAIN GONE WITH A BLENDED MODEL SOLUTION DUE TO THE
UNCERTAINTY. THIS MAINTAINS SOME CONSISTENCY IN THE FORECAST WITH
WARM AIR AND RAIN EXPECTED ACROSS MUCH OF CENTRAL AND WESTERN
NORTH DAKOTA DURING THE MORNING AND AFTERNOON TUESDAY. THE
EXCEPTION COULD BE THE FAR NORTH AND WEST WHERE COLDER AIR MAY
FAVOR SNOW. COLD AIR ARRIVES BEHIND THE LOW TUESDAY NIGHT...WHICH
SUPPORTS A THERMAL PROFILE TRANSITIONING TO SNOW ACROSS THE
FORECAST AREA. CONFIDENCE IN PRECIPITATION AND / OR SNOW AMOUNTS
REMAINS LOW DUE TO THE LARGE DIFFERENCES IN MODEL SOLUTIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 414 AM CDT SUN MAR 22 2015
FREEZING RAIN WILL BE POSSIBLE THROUGH 12-14Z FOR KISN-KDIK...ALL
SNOW EAST FOR KMOT-KBIS-KJMS. CURRENT VFR CONDITIONS NOW EXPECTED
TO MAINLY PERSIST. IFR CONDITIONS POSSIBLE FOR KBIS-KJMS AS SNOW
DEVELOPS LATER THIS MORNING. MODELS DO INDICATE A CORRIDOR OF LOW
STRATUS DEVELOPING DURING THE DAY SUNDAY INTO SUNDAY NIGHT CENTRAL
IMPACTING KBIS-KMOT-KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 11 AM CDT /10 AM MDT/ THIS MORNING
FOR NDZ033-034-040>045.
&&
$$
UPDATE...NH
SHORT TERM...NH
LONG TERM...CK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
414 AM CDT SUN MAR 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM CDT SUN MAR 22 2015
FORECAST HIGHLIGHTS AND CHALLENGES IN THE SHORT TERM PERIOD WILL
BE THE THREAT FOR FREEZING PRECIPITATION ACROSS THE SOUTHWEST THIS
MORNING...AND HOW PRECIPITATION EVOLVES EASTWARD.
CURRENTLY...ACTIVE ZONAL FLOW ALOFT WITH A POTENT SHORT WAVE
MOVING EAST INTO SOUTH CENTRAL CANADA AND ANOTHER MORE
SUBTLE/EMBEDDED FEATURE MOVING EAST ACROSS NORTHERN
WYOMING/SOUTHEASTERN MONTANA. ASSOCIATED SURFACE LOWS OVER
SOUTHERN SASKATCHEWAN AND EASTERN WY/SOUTHWESTERN SD RESPECTIVELY.
THE SOUTHERN MOST WAVE IS OUR MAIN CONCERN...GENERATING
PRECIPITATION FROM SOUTHEASTERN MONTANA EAST TO ACROSS
SOUTHWESTERN NORTH DAKOTA. THERMAL PROFILES AND SFC TEMPERATURES
INDICATING LIGHT FREEZING RAIN IS LIKELY FALLING. MADE A FEW CALLS
TO THE SOUTHWEST WHICH INDICATED NO IMPACTS AS SO FAR THE LIGHT
FREEZING PRECIP IS ONLY TRACING OUT. A VERY DRY EASTERLY FLOW IS
KEEPING THE BOUNDARY LAYER RATHER DRY FROM THE SURFACE UP TO 5-7K
FT AGL...SO ANY MOISTURE REACHING THE GROUND SHOULD BE LIMITED.
WILL MAINTAIN LIKELY POPS SOUTHWEST INTO SOUTH CENTRAL. HAVE A
SPECIAL WEATHER STATEMENT OUT NOW FOR THE FREEZING RAIN
POTENTIAL...AND WILL CONTINUE WITH THIS UNLESS WE HEAR OF MORE
IMPACTS AND A FREEZING RAIN ADVISORY BECOMES NEEDED. MORE RADAR
RETURNS ACROSS THE NORTH...BUT AGAIN WITH CLOUD BASES AT ROUGHLY
8-10K AGL...ANTICIPATE LITTLE IS REACHING THE GROUND SO WILL KEEP
POPS BELOW LIKELY THERE.
MODELS HAVING A HARD TIME THIS MORNING WITH EACH RUN OF THE HRRR
AND NAM MODELS DIFFERENT. BASICALLY WENT WITH A BLEND WHICH
FOLLOWS THE 00Z ECMWF AND LATEST 06Z NAM RATHER WELL. THIS
CONFINES HIGHER POPS THIS MORNING TO MY SOUTHERN COUNTIES...ALONG
TO SOUTH OF INTERSTATE 94. MAIN THREAT FOR FREEZING RAIN WILL
REMAIN WEST OF THE MISSOURI RIVER ACROSS MY SOUTHWEST THROUGH MID
MORNING...WITH THERMAL PROFILES SUGGESTING ALL SNOW TO THE EAST.
SURFACE FRONTAL BOUNDARY MOMENTARILY STALLS ACROSS THE WEST THIS
AFTERNOON...WITH A WESTERLY WIND TO THE WEST AND SOUTHERLY WIND
TO THE EAST. NAM AND RAP ARE INDICATING POSSIBLE STRATUS
DEVELOPMENT ALONG TO EAST OF THE BOUNDARY LATER TODAY INTO THIS
EVENING AS THE SOUTH/SOUTHEASTERLY FLOW TRANSPORTS MOISTURE NORTH.
THUS WILL KEEP SKY COVER ELEVATED ABOVE MOSTLY SUNNY/MOSTLY CLEAR.
CONFIDENCE NOT HIGH WITH THIS PLAYING OUT WITH MODELS STRUGGLING
THE PAST FEW RUNS.
AFOREMENTIONED STRONG SHORT WAVE CUTTING EAST ACROSS SOUTH CENTRAL
CANADA WILL TURN SOUTHEAST AND MOVE INTO FAR NORTHEASTERN
ND/NORTHERN MINNESOTA THIS SUNDAY NIGHT. PRECIPITATION IN THE FORM
OF SNOW MAY GRAZE MY FAR NORTHEAST SO WILL MAINTAIN A LOW POP THERE
TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM CDT SUN MAR 22 2015
THE PRIMARY CONCERN IN THE LONG TERM PERIOD WILL BE THE POTENT
STORM MONDAY NIGHT INTO TUESDAY. THE LATEST MODEL SUITE CONTINUES
TO ADVERTISE A POTENT STORM SYSTEM ACROSS THE NORTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. DETAILS REGARDING THE EXACT TRACK OF
THE SYSTEM REMAIN ELUSIVE WITH THE 00Z GFS AND ECMWF STILL SHOWING
DIFFERENCES...AND LARGE SPREAD INDICATED BY THE GEFS.
THE ECMWF AND GFS BOTH SUGGEST TWO SURFACE LOWS WILL
DEVELOP...HOWEVER THEY DIFFER ON THE PROGRESSION OF THE NORTHERN
MOST LOW. THE ECMWF KEEPS THE LOWS SEPARATE WITH ONE TRACKING INTO
CANADA...WHILE THE GFS MERGES THE LOWS IN MINNESOTA / WISCONSIN.
HAVE AGAIN GONE WITH A BLENDED MODEL SOLUTION DUE TO THE
UNCERTAINTY. THIS MAINTAINS SOME CONSISTENCY IN THE FORECAST WITH
WARM AIR AND RAIN EXPECTED ACROSS MUCH OF CENTRAL AND WESTERN
NORTH DAKOTA DURING THE MORNING AND AFTERNOON TUESDAY. THE
EXCEPTION COULD BE THE FAR NORTH AND WEST WHERE COLDER AIR MAY
FAVOR SNOW. COLD AIR ARRIVES BEHIND THE LOW TUESDAY NIGHT...WHICH
SUPPORTS A THERMAL PROFILE TRANSITIONING TO SNOW ACROSS THE
FORECAST AREA. CONFIDENCE IN PRECIPITATION AND / OR SNOW AMOUNTS
REMAINS LOW DUE TO THE LARGE DIFFERENCES IN MODEL SOLUTIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 414 AM CDT SUN MAR 22 2015
FREEZING RAIN WILL BE POSSIBLE THROUGH 12-14Z FOR KISN-KDIK...ALL
SNOW EAST FOR KMOT-KBIS-KJMS. CURRENT VFR CONDITIONS NOW EXPECTED
TO MAINLY PERSIST. IFR CONDITIONS POSSIBLE FOR KBIS-KJMS AS SNOW
DEVELOPS LATER THIS MORNING. MODELS DO INDICATE A CORRIDOR OF LOW
STRATUS DEVELOPING DURING THE DAY SUNDAY INTO SUNDAY NIGHT CENTRAL
IMPACTING KBIS-KMOT-KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NH
LONG TERM...CK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
330 AM CDT SUN MAR 22 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM CDT SUN MAR 22 2015
SNOW CHANCES AND AMOUNTS WILL BE THE CHALLENGE. 00Z MODELS IN
DECENT AGREEMENT...ALTHOUGH THERE ARE SOME DIFFERENCES TODAY.
RIDGING REMAINS IN PLACE ACROSS THE REGION WITH DRY LOW LEVEL
EASTERLY FLOW. MODEL TRENDS INDICATE LESS INTERACTION BETWEEN NORTHERN
AND SOUTHERN UPPER WAVES...LEADING TO FAR LESS QPF ACROSS THE
WESTERN FA TODAY. IN FACT...THE LATEST HRRR AND RAP GUIDANCE
INDICATES THAT QPF WILL REMAIN OUTSIDE OF THE FA WITH STRONGER
RIDGING/MORE DRY AIR. TRENDED THE FORECAST IN THIS
DIRECTION...WITH MAYBE AN INCH OR TWO OF SNOW ACROSS THE FAR
SOUTHERN FA. WILL CONTINUE TO MONITOR TRENDS AND MAY EVENTUALLY
REMOVE ALL POPS FOR TODAY. WITH THIS...MODELS ARE TRENDING WARMER
TODAY (THINNER CLOUD COVER)...AND FOLLOWED THIS TREND IN THE
FORECAST.
TONIGHT...THE NORTHERN UPPER WAVE IS QUITE STRONG...AND MODELS
HAVE BEEN CONSISTENT SPREADING SNOW INTO PARTS OF THE NORTHERN FA
(WITH AN INCH OR TWO POSSIBLE).
MONDAY...REGION WILL BE BETWEEN SYSTEMS ALONG WITH WARM AIR
ADVECTION AHEAD OF THE NEXT SYSTEM. SHOULD BE A RELATIVELY QUIET
DAY WITH MAX TEMPS APPROACHING OR INTO THE 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM CDT SUN MAR 22 2015
MONDAY NIGHT-TUESDAY NIGHT...STRONGER SYSTEM WILL AFFECT THE
REGION...MOST LIKELY LATER TUESDAY INTO TUESDAY NIGHT. CONFIDENCE
IS HIGH THAT SOMETHING IS GOING TO OCCUR...ALTHOUGH MODELS ARE
ALL OVER THE PLACE WITH DETAILS SO EXACTLY WHAT OCCURS IS HIGHLY
QUESTIONABLE. GENERALLY...THE REGION WILL BE WITHIN AN INVERTED
TROUGH WITH RAIN EVENTUALLY CHANGING TO SNOW. SOME MODELS ARE
INDICATING OVER A FOOT OF SNOW...WITH OTHERS FAR LESS (OR ALMOST
NOTHING). MUCH WILL DEPEND ON HOW THE SYSTEM EVOLVES...AND
WHEN/WHERE THE SOUTHERN SFC LOW STRENGTHENS (WHICH WILL INFLUENCE
THE STRENGTH OF THE INVERTED TROUGH AND THUS QPF AMOUNTS). FOR
NOW...THE BEST THING TO SAY IS RAIN CHANGING TO SNOW WITH SOME
ACCUMULATIONS POSSIBLE.
WEDNESDAY-SATURDAY...THE BACKSIDE OF THE FULLY DEVELOPED CLOSED-
LOW SYSTEM OVER WISCONSIN AND MOVING EASTWARD WILL BRING AN END TO
THE PRECIPITATION OVER WEST-CENTRAL MINNESOTA WITH THE NORTHERLY
WINDS ADVECTING IN SOME COOLER DAYTIME TEMPERATURES IN THE 30S AND
LOWS IN THE TEENS FOR WEDNESDAY. A SURFACE HIGH PRESSURE SYSTEM
WILL BE IN PLACE OVER THE AREA BY THURSDAY AHEAD OF A BUILDING
UPPER-AIR RIDGE ON THE WEST COAST. THAT HIGH WILL BE SHIFTING TO
THE EAST WITH SOME SOUTHERLY WINDS ON ITS BACKSIDE BRINGING IN
SOME WARMER AIR FOR FRIDAY AND SATURDAY. HOWEVER...AN EMBEDDED
UPPER-AIR SHORT WAVE EMBEDDED IN THE NORTHWEST FLOW FROM WESTERN
RIDGE WILL BRING GOOD CHANCES FOR WEEKEND PRECIPITATION AS ANOTHER
SURFACE LOW SPINS UP TO TRAVERSE THE REGION OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1139 PM CDT SAT MAR 21 2015
REALLY NO CHANGE IN CIGS ANTICIPATED AS DRY LOWER LEVELS SHOULD
LIMIT ANY LOWER CLOUD DEVELOPMENT. LOW CONFIDENCE IN SNOW
POTENTIAL ACROSS TAF SITES TOMORROW SO LEFT DRY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...TG
LONG TERM...TG/LUKES
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
125 AM CDT SUN MAR 22 2015
.UPDATE...
ISSUED AT 125 AM CDT SUN MAR 22 2015
POOR MODEL PERFORMANCE THE PAST FEW DAYS HAS LED TO SOME RATHER
BIG MODIFICATIONS FOR THE SHORT TERM FORECAST TONIGHT THROUGH
SUNDAY. HIGH RES NMM/ARW...ALONG WITH THE HRRR AND SREF/NAM BRING
THE HEAVIER PRECIPITATION THIS MORNING NOW ACROSS MY SOUTHERN
COUNTIES WITH ONLY SCATTERED ACTIVITY NOW ACROSS THE NORTH.
REGIONAL RADAR SUPPORTS THIS. POPS WERE ADJUSTED.
MAIN CONCERN IS THE POTENTIAL FOR FREEZING RAIN ACROSS PORTIONS OF
THE SOUTHWEST. ALONG THE MONTANA BORDER AIR TEMPERATURES WILL
REMAIN WARM ENOUGH TO KEEP PRECIPITATION ALL RAIN. FARTHER TO THE
EAST FROM DUNN COUNTY SOUTH THROUGH STARK...HETTINGER...AND ADAMS
COUNTIES...SURFACE TEMPERATURE FORECAST ALONG WITH THERMAL
PROFILES WILL SUPPORT FREEZING RAIN...WITH ICE ACCUMULATIONS
LIKELY. STILL SOME UNCERTAINTY WHETHER TEMPERATURES WILL WARM OR
NOT AS PRECIPITATION DEVELOPS INTO THIS AREA FROM THE WEST. PLAN
RIGHT NOW IS TO HIGHLIGHT THE POTENTIAL WITH A SPECIAL WEATHER
STATEMENT AND MONITOR IN CASE A FREEZING RAIN ADVISORY BECOMES
NEEDED. PRECIP TYPE WILL BECOME ALL SNOW AS THE AREA OF
PRECIPITATION TRACKS FARTHER EAST INTO MORTON AND GRANT COUNTIES
AND POINTS EAST. ACCUMULATIONS ARE EXPECTED IF HIGH RES MODELS
HOLD TRUE...RIGHT NOW AROUND AN INCH.
UPDATE ISSUED AT 903 PM CDT SAT MAR 21 2015
RADAR SHOWS STEADY LIGHT SNOW IN ROLLA THAT WILL LAST FOR A FEW
HOURS. THEN FOCUS WILL TURN TO THE WEST WHERE LOW LEVEL WARM
ADVECTION AND FRONTAL BOUNDARY WILL FOCUS LIGHT RAIN THIS
EVENING...WITH A WINTRY MIX OF RAIN...FREEZING RAIN OR SLEET AND
SOME SNOW POSSIBLE AFTER MIDNIGHT. NEW NAM NOW PLACES MOST OF THE
PRECIP IN CANADA. BUT BOTH NAM AND HRRR GENERATE A RAIN AREA
SOUTHWEST TONIGHT. STILL MUCH UNCERTAINTY AT THIS LATE TIME. AM
MORE COMFORTABLE WITH LESS FREEZING RAIN AND MORE RAIN THROUGH
MIDNIGHT...WILL MONITOR AFTER MIDNIGHT BUT IF NAM IS RIGHT MOST OF
PRECIP WILL BE NORTH IN CANADA.
UPDATE ISSUED AT 646 PM CDT SAT MAR 21 2015
CLOUDS ARE INCREASING WEST ASSOCIATED WITH A SHORTWAVE TROUGH
MOVING INTO THE NORTHERN PLAINS. WARM AIR ACROSS EASTERN MONTANA
WILL MOVE OVER COOLER SURFACE AIR ACROSS WESTERN NORTH DAKOTA
LATER TONIGHT. THIS COULD CREATE SOME FREEZING PRECIPITATION.
SURFACE TEMPERATURES TO SAY THE LEAST WILL BE CRITICAL FOR THIS.
AT 6 PM CROSBY RAWS IS 27 AND WILLISTON 41. WILL CONTINUE TO
MONITOR. SO FAR CURRENT FORECAST LOOKS OK.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 320 PM CDT SAT MAR 21 2015
CURRENT SURFACE ANALYSIS PLACES LOW STRETCHING GENERALLY ALONG THE
LEE SIDE OF THE ROCKIES WHILE HIGH STRETCHES FROM THE RED RIVER
VALLEY UP INTO MANITOBA. UPPER LEVEL ANALYSIS PLACES RIDGE OVER
EASTERN MONTANA UP INTO SASKATCHEWAN/ALBERTA WHILE DEEP LOW SPINS
NEAR JAMES BAY BRINGING NORTHWEST FLOW TO OUR AREA. POTENT SHORT
WAVE OVER THE NORTHWESTERN CONUS CONTINUES ITS EASTWARD PUSH. SOME
LIGHT SNOW CONTINUES TO LINGER OVER THE NORTH CENTRAL PART OF THE
STATE IN WEAK ISENTROPIC LIFT...THOUGH AREA WEBCAMS INDICATE VERY
LITTLE IF ANY ACCUMULATION.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...AFOREMENTIONED LIGHT
SNOW OVER THE NORTH WILL CONTINUE TO SLOWLY DISSIPATE.
OTHERWISE...MAIN CONCERN WILL BE THE SHORT WAVE OVER THE
NORTHWESTERN CONUS MAKING ITS ADVANCE TOWARDS THE AREA. SHORT WAVE
WILL PUSH ITS WAY OVER THE RIDGE...WITH PRECIPITATION DEVELOPING
OVER THE WEST THIS EVENING AND SPREADING EAST OVERNIGHT. MOST
LOCATIONS SHOULD SEE SNOW...OR POSSIBLY SOME RAIN OVER THE WEST
WHERE TEMPERATURES WILL BE SLOWLY FALLING. LATER
TONIGHT...FORECAST SOUNDINGS SUGGEST THE POSSIBILITY OF A LITTLE
SLEET OF FREEZING RAIN MAINLY OVER THE FAR WEST SO HAVE ADDED A
MENTION OF THAT.
ON SUNDAY...SNOW WILL DIMINISH FROM WEST TO EAST AS SHORT WAVE
CONTINUES ITS PROGRESSION THROUGH THE AREA. TOTAL SNOW AMOUNTS
FROM THIS SYSTEM STILL LOOK TO BE THE HIGHEST MAINLY OVER NORTH
CENTRAL NORTH DAKOTA INTO PARTS OF THE NORTHWEST. TEMPERATURES
WILL REMAIN THE COOLEST MAINLY OVER THE CENTRAL PART OF THE STATE
WHILE TO THE WEST EXPECT TEMPERATURES TO REBOUND AS SYSTEM MOVES
TO THE EAST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 320 PM CDT SAT MAR 21 2015
A POTENT SYSTEM COULD IMPACT THE REGION MIDWEEK.
THE LATEST SUITE OF MODELS CONTINUES TO SLOW DOWN THE PROGRESSION
OF OUR MID WEEK SYSTEM. PREVIOUS RUNS HAD PRECIPITATION BEGINNING
MONDAY NIGHT WEST. HOWEVER...IT NOW APPEARS PRECIPITATION WILL BE
DELAYED UNTIL TUESDAY.
THERE IS STILL A LOT OF UNCERTAINTY IN THE EXACT TRACK OF THIS
SYSTEM. OVER THE PAST TWO MODEL RUNS THE GFS HAS ONCE AGAIN
COMPLETELY FLIP FLOPPED FROM A NORTHERN SOLUTION TO A SOUTHERN
SOLUTION. THE ECMWF REMAINS FAIRLY CONSISTENT...WITH AN EVER SO
SLIGHTLY FURTHER NORTH TRACK THAN THE 00 UTC RUN. THE GFS ENSEMBLE
SPREAD IS RATHER WIDE...WITH THE CENTER OF THE LOW ANYWHERE FROM
SOUTHERN CANADA TO NORTHERN IOWA.
FOR THIS FORECAST...UTILIZED A BLEND OF THE OPERATIONAL MODELS.
THIS LED TO GENERALLY LESSER AMOUNTS OF SNOW SOUTH OF HIGHWAY 2.
IT APPEARS THAT MOST OF WESTERN AND CENTRAL NORTH DAKOTA WILL SEE
TEMPERATURES WARM ENOUGH FOR ALL RAIN DURING THE MORNING AND
AFTERNOON HOURS...AND THEN SEE A TRANSITION FROM NORTH TO SOUTH TO
ALL SNOW OVERNIGHT. AT THIS TIME IT APPEARS THAT ONLY LOCATIONS
NORTH OF HIGHWAY 2 WILL SEE BELOW FREEZING TEMPERATURES
THROUGHOUT TUESDAY AND WEDNESDAY. TEMPERATURES WILL VARY GREATLY
BASED ON THE EXACT TRACK OF THE LOW PRESSURE CENTER.
THEREFORE...HEAVY SNOWFALL IS POSSIBLE WITH THIS SYSTEM AS STRONG
FRONTOGENESIS...DEFORMATION BANDING...AND POTENTIAL TROWL SET UP
ACROSS SOME PORTION OF NORTH DAKOTA...BUT AT THE SAME TIME IT
COULD TURN OUT TO BE SIMPLY A HEAVY RAIN EVENT FOR WESTERN AND
CENTRAL NORTH DAKOTA. THERE IS JUST TOO MUCH UNCERTAINTY AT THIS
TIME TO NAIL DOWN SPECIFIC LOCATIONS AND SNOWFALL AMOUNTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 125 AM CDT SUN MAR 22 2015
FREEZING RAIN WILL BE POSSIBLE THROUGH 12Z FOR KISN-KDIK...ALL
SNOW EAST FOR KMOT-KBIS-KJMS. CURRENT VFR CONDITIONS NOW EXPECTED
TO MAINLY PERSIST. IFR CONDITIONS POSSIBLE FOR KBIS-KJMS AS SNOW
DEVELOPS LATER THIS MORNING. MODELS DO INDICATE A CORRIDOR OF LOW
STRATUS DEVELOPING DURING THE DAY SUNDAY INTO SUNDAY NIGHT CENTRAL
IMPACTING KBIS-KMOT-KJMS. SOME UNCERTAINTY WITH THIS RIGHT NOW.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...JJS
LONG TERM...AJ
AVIATION...NH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
638 AM EDT SUN MAR 22 2015
.SYNOPSIS...
HIGH PRESSURE IN CHARGE THROUGH MONDAY. LOW PRESSURE SYSTEM BRINGS
UNSETTLED WEATHER MID-WEEK. HIGH PRESSURE IN CHARGE AGAIN NEXT
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE...LOW TO MID TEEN DEW POINTS IN NORTHERN/EASTERN OHIO
ADVECTING OUR WAY...SO TOOK A COUPLE DEGREES OFF PREVIOUS DEW POINT
FORECAST...UNDERCUTTING MOS GUIDANCE. HRRR IS EVEN LOWER...BUT
SEEMS TOO LOW. OTHERWISE NO CHANGES MADE.
PREVIOUS DISCUSSION...
COLD FRONT EXITING TO THE SOUTH EARLY THIS MORNING...WITH HIGH
PRESSURE DROPPING INTO THE GREAT LAKES. THIS HIGH WILL KEEP POPS
ASSOCIATED WITH A SOUTHERN STREAM SYSTEM TO OUR SOUTH AND EAST
THROUGH THE NEAR TERM PERIOD. WILL HAVE SOME CIRRUS CLOUDS
ASSOCIATED WITH THAT SYSTEM...AND ALSO LOOKING AT SOME CLOUDS IN
THE NORTHERN PLAINS THAT WILL HEAD OUR WAY IN NW FLOW ALOFT.
NORTH OF THE COLD FRONT...TEMPS WILL BE COOLER THAN YESTERDAY. TODAY
HIGHS SHOULD TOP OUT IN THE 40S AND 50S...WITH 20S TO LOW 30S
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MODELS INDICATE A WARM FRONT WILL DEVELOP TO OUR SOUTHWEST BY
LATE MONDAY...WITH AN INVERTED TROF POSSIBLY EXTENDING NORTHEAST
INTO OUR MOUNTAIN COUNTIES. AIRMASS SHOULD BE DRY AND DO NOT
EXPECT ANY PRECIPITATION WITH THE TROF.
THE WARM FRONT WILL LIFT SLOWLY NORTHEAST MONDAY NIGHT INTO
TUESDAY...WITH AN INVERTED TROF REMAINING ACROSS OUR MOUNTAINS
COUNTIES. MODELS SUGGEST PRECIPITATION MAY DEVELOP OVER THE
MOUNTAINS LATE MONDAY NIGHT. NOT REAL CONFIDENT ABOUT THIS...SO
HAVE GONE WITH SLIGHT CHANCE POPS.
WARM FRONT WILL CONTINUE TO MOVE NORTHEAST BEFORE PUSHING INTO THE
REGION TUESDAY NIGHT...AND THEN NORTH OF THE AREA BY EARLY
WEDNESDAY. THIS SHOULD RESULT IN A CHANCE OF PRECIPITATION ACROSS
THE NORTHERN TWO-THIRDS OF THE AREA TUESDAY NIGHT. THE BEST
CHANCES FOR PRECIPITATION SHOULD LIFT NORTH ON WEDNESDAY WITH THE
WARM FRONT. A COLD FRONT WILL THEN APPROACH THE AREA BY LATE
WEDNESDAY...BRINGING ADDITIONAL SHOWERS TO THE AREA.
GFS SUGGESTS SOME INSTABILITY WILL DEVELOP ACROSS OUR
SOUTHWESTERN COUNTIES WEDNESDAY AFTERNOON. HAVE NOT INCLUDED
MENTION OF THUNDER IN FORECAST AT THIS TIME...BUT IT WILL
SOMETHING THAT MAY NEED TO BE ADDED.
FORECAST TEMPS LOOK GOOD AND ARE GENERALLY A MIX OF THE LATEST
MET/MAV NUMBERS...SO ONLY MADE SOME TWEAKS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
THIS PERIOD FEATURES A STRONG COLD FRONT COMING THRU LATE WEDNESDAY
NIGHT AND THURSDAY. IN THIS CASE...THERE IS PHASING BETWEEN THE
NORTHERN AND SOUTHERN STREAM FLOW ACROSS THE NATION...ALLOWING A
DEEPENING LOW PRESSURE SYSTEM TO LIFT FROM THE PLAINS INTO THE GREAT
LAKES WEDNESDAY. A WARM FRONT AHEAD OF THE LOW WILL LIFT UP TUESDAY
NIGHT WITH A FEW SHOWERS MAINLY NORTH AND WEST IN THE BETTER LIFT
AND MAXIMUM MOISTURE INFLOW. OTHERWISE...TUESDAY NIGHT LOOKS TO BE
MILD WITH A SOUTHERLY BREEZE KICKING IN. WE WILL BE IN THE WARM
SECTOR WEDNESDAY...WITH AN INCREASINGLY WARM AND MOIST SOUTHERLY
FLOW UNDER PARTIAL SUNSHINE TO BRING TEMPERATURES UP AROUND 70
DEGREES. SOME SHOWERS MAY SPREAD MAINLY INTO SOUTHEAST OHIO
WEDNESDAY AFTERNOON AS THE COLD FRONT APPROACHES FROM THE WEST...BUT
MOST AREAS WILL BE DRY.
THE COLD FRONT IS PROGGED TO MOVE ACROSS THE AREA LATE WEDNESDAY
NIGHT AND THURSDAY...BUT MAY BE SLOWED A BIT AS MODELS INDICATE A
POSSIBLE WAVE RIPPLING UP ALONG THE FRONT. IN ANY CASE...A GOOD
SURGE OF MOIST AND MARGINALLY UNSTABLE AIR WILL COMBINE WITH UPPER
DYNAMICS AHEAD OF THE COLD FRONT TO PRODUCE A BAND OF RAIN
SHOWERS...AND POSSIBLY A THUNDERSTORM. UPON PASSAGE OF THE FRONT
THURSDAY...MUCH COOLER BUT STILL MOIST AIR UNDER THE UPPER TROUGH WILL
CONTINUE SCATTERED RAIN SHOWERS THURSDAY NIGHT AND FRIDAY...
ESPECIALLY IN THE MOUNTAINS WITH AN UPSLOPE COMPONENT. ENOUGH COLD
AIR ALOFT WILL MOVE IN TO CHANGE RAIN SHOWERS TO SNOW SHOWERS LATER
THURSDAY NIGHT AND FRIDAY IN THE NORTHERN MOUNTAINS...BUT LITTLE
ACCUMULATION IS EXPECTED.
CANADIAN HIGH PRESSURE WILL FINALLY BRING DRY BUT COOL AIR FOR THE
BEGINNING OF THE WEEKEND.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
SOME MVFR IN STRATUS ACROSS NORTHERN TAF SITES. CKB EVEN WENT IFR
FOR A BRIEF PERIOD. HAVE MVFR AT PKB...CKB AND EKN TO START THE
TAF PERIOD...WITH IMPROVEMENT TO VFR OVER THE NEXT SEVERAL HOURS.
VFR EXPECTED ELSEWHERE THROUGH THE TAF PERIOD. GENERALLY LIGHT
NORTHERLY WINDS EXPECTED TODAY AS HIGH PRESSURE MOVES INTO THE
GREAT LAKES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING OF IMPROVEMENT OF MVFR CIGS MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY H H H H M M H H H H H H
HTS CONSISTENCY H H H H M H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L M M M M H H H H H H
PKB CONSISTENCY M M M M H H H H H H H H
CKB CONSISTENCY M M M M M H H H H H H H
AFTER 12Z MONDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JSH/MZ
NEAR TERM...MZ
SHORT TERM...JSH
LONG TERM...JMV
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS NORMAN OK
600 PM CDT SUN MAR 22 2015
.AVIATION...
LOW CLOUDS AND FOG ARE EXPECTED OVER MUCH OF THE WESTERN HALF OF
OKLAHOMA EARLY MONDAY. THE MVFR AND IFR SHOULD CLEAR BY 231700
FROM EAST TO WEST. GUSTY SOUTH WINDS WILL DEVELOP MONDAY
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 224 PM CDT SUN MAR 22 2015/
DISCUSSION...
LOW CLOUDS WILL CONTINUE TO ERODE THROUGH THE AFTERNOON ACROSS
SOUTHWEST OKLAHOMA AND NORTH TEXAS. NAM AND RAP SOUNDINGS SUGGEST
THAT FOG...SOME DENSE...WILL REFORM AGAIN TONIGHT...ESPECIALLY
ACROSS WEST CENTRAL...SOUTHWEST OKLAHOMA AND NORTH TEXAS.
ON MONDAY...AN ISOLATED STORM OR TWO MAY DEVELOP IN FAR WESTERN
OKLAHOMA NEAR A DRYLINE. BETTER CHANCES WILL REMAIN NORTH AND
EAST OF THIS AREA MONDAY NIGHT AND EARLY TUESDAY NORTH OF A WARM
FRONT IN KANSAS. EARLY TUESDAY...DRIER AIR WILL PUSH INTO WESTERN
PARTS OF OKLAHOMA AND NORTH TEXAS...AS A SHORTWAVE TROUGH MOVES
ACROSS THE CENTRAL PLAINS. BREEZY NORTHWEST TO WEST WINDS TUESDAY
AFTERNOON AND RATHER LOW HUMIDITY WILL INCREASE THE CHANCE OF
WILDFIRES.
FARTHER EAST...THUNDERSTORMS WILL BE POSSIBLE...MAINLY IN EASTERN
OKLAHOMA. MOISTURE WILL QUICKLY RETURN ON WEDNESDAY AHEAD OF
ANOTHER FRONT. STORM CHANCES WILL INCREASE BY WEDNESDAY
AFTERNOON...ESPECIALLY ALONG AND SOUTHEAST OF INTERSTATE 44.
INSTABILITY AND SHEAR WILL SUPPORT SEVERE STORMS...BUT FAVOR
LOWER DEWPOINT VALUES GFS/EC COMPARED WITH NAM12. HAIL...STRONG
WINDS AND HEAVY RAIN WILL BE THE IMPACTS WITH STORMS WEDNESDAY
AFTERNOON AND EVENING.
COOLER AND DRIER AIR WILL FILTER INTO THE SOUTHERN PLAINS THURSDAY
INTO FRIDAY. ANOTHER TROUGH WILL MOVE ACROSS THE AREA ON FRIDAY.
ASSOCIATED CLOUD COVER SHOULD KEEP TEMPERATURES FROM FALLING TO
OR BELOW FREEZING IN NORTHERN OKLAHOMA EARLY FRIDAY MORNING.
MANY AREAS HAVE BEEN ABOVE FREEZING FOR AN EXTENDED PERIOD. EARLY
SATURDAY MORNING...A FEW AREAS ACROSS THE NORTHERN HALF OF THE
STATE MAY SEE A LIGHT FREEZE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 50 77 59 80 / 0 0 0 0
HOBART OK 49 80 54 81 / 0 0 0 0
WICHITA FALLS TX 49 81 58 84 / 0 0 0 0
GAGE OK 46 82 49 79 / 0 10 0 0
PONCA CITY OK 48 78 57 79 / 0 10 20 0
DURANT OK 47 74 55 79 / 0 0 0 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
23/09/09
AREA FORECAST DISCUSSION
NWS NORMAN OK
224 PM CDT SUN MAR 22 2015
.DISCUSSION...
LOW CLOUDS WILL CONTINUE TO ERODE THROUGH THE AFTERNOON ACROSS
SOUTHWEST OKLAHOMA AND NORTH TEXAS. NAM AND RAP SOUNDINGS SUGGEST
THAT FOG...SOME DENSE...WILL REFORM AGAIN TONIGHT...ESPECIALLY
ACROSS WEST CENTRAL...SOUTHWEST OKLAHOMA AND NORTH TEXAS.
ON MONDAY...AN ISOLATED STORM OR TWO MAY DEVELOP IN FAR WESTERN
OKLAHOMA NEAR A DRYLINE. BETTER CHANCES WILL REMAIN NORTH AND
EAST OF THIS AREA MONDAY NIGHT AND EARLY TUESDAY NORTH OF A WARM
FRONT IN KANSAS. EARLY TUESDAY...DRIER AIR WILL PUSH INTO WESTERN
PARTS OF OKLAHOMA AND NORTH TEXAS...AS A SHORTWAVE TROUGH MOVES
ACROSS THE CENTRAL PLAINS. BREEZY NORTHWEST TO WEST WINDS TUESDAY
AFTERNOON AND RATHER LOW HUMIDITY WILL INCREASE THE CHANCE OF
WILDFIRES.
FARTHER EAST...THUNDERSTORMS WILL BE POSSIBLE...MAINLY IN EASTERN
OKLAHOMA. MOISTURE WILL QUICKLY RETURN ON WEDNESDAY AHEAD OF
ANOTHER FRONT. STORM CHANCES WILL INCREASE BY WEDNESDAY
AFTERNOON...ESPECIALLY ALONG AND SOUTHEAST OF INTERSTATE 44.
INSTABILITY AND SHEAR WILL SUPPORT SEVERE STORMS...BUT FAVOR
LOWER DEWPOINT VALUES GFS/EC COMPARED WITH NAM12. HAIL...STRONG
WINDS AND HEAVY RAIN WILL BE THE IMPACTS WITH STORMS WEDNESDAY
AFTERNOON AND EVENING.
COOLER AND DRIER AIR WILL FILTER INTO THE SOUTHERN PLAINS THURSDAY
INTO FRIDAY. ANOTHER TROUGH WILL MOVE ACROSS THE AREA ON FRIDAY.
ASSOCIATED CLOUD COVER SHOULD KEEP TEMPERATURES FROM FALLING TO
OR BELOW FREEZING IN NORTHERN OKLAHOMA EARLY FRIDAY MORNING.
MANY AREAS HAVE BEEN ABOVE FREEZING FOR AN EXTENDED PERIOD. EARLY
SATURDAY MORNING...A FEW AREAS ACROSS THE NORTHERN HALF OF THE
STATE MAY SEE A LIGHT FREEZE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 50 77 59 80 / 0 0 0 0
HOBART OK 49 80 54 81 / 0 0 0 0
WICHITA FALLS TX 49 81 58 84 / 0 0 0 0
GAGE OK 46 82 49 79 / 0 10 0 0
PONCA CITY OK 48 78 57 79 / 0 10 20 0
DURANT OK 47 74 55 79 / 0 0 0 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND
904 PM PDT MON MAR 23 2015
.SYNOPSIS...A COMPACT SURFACE LOW CENTER WILL CROSS THE COAST AND
MOVE EAST ALONG THE COLUMBIA GORGE TONIGHT. IT WILL BRING RAIN AND
MOUNTAIN SNOW TONIGHT PLUS VERY WINDY CONDITIONS SOUTH OF THE TRACK
OF THE LOW CENTER. SHOWERS WILL DECREASE TUESDAY AS WE ARE IN
BETWEEN SYSTEMS. A WARM FRONT WILL MOVE NORTHEAST THROUGH THE
FORECAST AREA TUESDAY NIGHT AND WEDNESDAY FOR SOME AREAS OF LIGHT
RAIN AS AN UPPER RIDGE BUILDS OFF THE COAST. THE UPPER RIDGE WILL
BRING DRY AND MILD WEATHER TO THE AREA AGAIN THURSDAY AND FRIDAY. A
WEAK AND SPLITTING SYSTEM MAY AFFECT THE AREA THIS WEEKEND.
&&
.UPDATE...MINIMAL UPDATES NEEDED TONIGHT AS THE COMPACT SURFACE LOW
CENTER IS ABOUT 80 MILES OFF THE CAPE FOULWEATHER COAST AT THIS HOUR
AND IS BRINGING 35 TO 40 MPH SOUTHERLY GUSTS SOUTH OF NEWPORT. THE
SURFACE LOW RAN DIRECTLY BETWEEN BUOYS 2 AND 5 AND WOULD ESTIMATE
LOW PRESSURE HAS REACHED IT`S MINIMUM OF AROUND 1009 MB. NOT A
PARTICULARLY STRONG LOW AS COMPARED TO HISTORICAL EVENTS BUT IT DOES
BRING A MODEST PRESSURE FALL/RISE COUPLET AND THUS THE BRIEF PERIOD
OF GUSTY WINDS. THE HRRR SEEMS TO HAVE A VERY GOOD GRASP ON THIS
SYSTEM AND BRINGS THE LOW CENTER EAST TO OVER THE METRO AROUND
MIDNIGHT AND THEN OVER THE GORGE A SHORT TIME LATER AND FINALLY
PUSHING IT EAST OF THE CASCADE CREST BY 2 AM. WILL LIKELY SEE 3 HOUR
PRESSURE RISES AROUND 4 TO 6 MB FROM THE WEST AND THIS STANDS TO
IMPACT THE COAST AND MORE INLAND COASTAL COMMUNITIES THE MOST WITH
THE SOUTHERLY/SOUTHWESTERLY WINDS JUST AHEAD OF THE LOW CENTER
PASSING NORTH AND THEN A DECENT BURST OF WESTERLY WINDS BEHIND IT.
THE ORIENTATION OF WILLAMETTE VALLEY WILL SOMEWHAT LIMIT THE IMPACT
BUT FEEL GOOD ABOUT AT LEAST 40 MPH GUSTS FOR A COUPLE HOURS AROUND
MIDNIGHT MAINLY FROM WOODBURN SOUTHWARD AND PERHAPS A LITTLE
STRONGER FURTHER SOUTH TOWARD EUGENE. PORTIONS OF THE METRO MAY SEE
THEIR STRONGEST GUSTS AFTER THE LOW PASSES OVERHEAD WITH AIR RUSHING
TO FILL IN BEHIND IT. DON`T THINK THE STRONGEST NORTHWESTERLY GUSTS
WILL GO MUCH HIGHER THAN 35 MPH.
SNOW AMOUNTS HAVE BEEN MODEST THUS FAR WITH SNOTEL SENORS AND ODOT
REPORTING 2 TO 4 INCHES IN THE LAST SEVERAL HOURS. EXPECT RATES WILL
CONTINUE TO INCREASE TONIGHT AS THE LOW APPROACHES AND THEN MODERATE
SOMEWHAT UNDER A COOLER MORE OROGRAPHIC REGIME OVERNIGHT TONIGHT.
DID FUSS WITH POPS A BIT TONIGHT THROUGH EARLY TOMORROW TO SHOW A
FASTER DROP OFF ALONG THE WATERS AND TOWARD THE I-5 CORRIDOR EARLY
TOMORROW. UPDATES WILL BE AVAILABLE SHORTLY. /JBONK
&&
.PREV DISC... /ISSUED 237 PM PDT MON MAR 23 2015/
SHORT TERM...THIS AFTERNOON THROUGH THURSDAY...THE SYNOPTIC PICTURE
THIS AFTERNOON LOOKS SIMILAR TO THIS MORNING WITH ONE LOW OFF
VANCOUVER ISLAND AND ANOTHER WELL WEST OF THE OREGON COAST. SHOWERS
CONTINUE LOCALLY AS A VIGOROUS SHORTWAVE AND BAND OF POSITIVE
VORTICITY MOVE NORTH ACROSS THE AREA. THESE FEATURES STILL HAVE A
SLIGHT CHANCE OF HELPING SHOWERS PRODUCE A LIGHTNING STRIKE OR
TWO...BUT CHANCES APPEAR TO BE DWINDLING AS SHOWERS JUST CANNOT SEEM
TO BUILD HIGH ENOUGH FOR LIGHTNING. THE FREEZING LEVEL ON THE SALEM
12Z SOUNDING WAS ONLY ABOUT 4000 FT WHICH HAS ALLOWED SOME PEA-SIZED
HAIL TO FALL WITH SHOWERS...BUT WITH THE -20C LEVEL AT ABOUT 14500
FT...SHOWERS WOULD HAVE TO HAVE SIGNIFICANT HEIGHT TO ACHIEVE
LIGHTNING. HAVE LEFT ONLY A SLIGHT CHANCE OF THUNDER IN THE FORECAST
THROUGH 00Z BUT ADDITIONAL SMALL HAIL SEEMS MORE LIKELY AT THIS
POINT. MOST RECENT HRRR RUN SHOWS WHAT HAS BEEN A CONSISTENT MODEL
TREND OF SHOWERS TAPERING OFF A BIT THROUGH MID AFTERNOON BEFORE
RAIN ASSOCIATED WITH THE NEXT LOW PRESSURE SYSTEM BEGINS TO MOVE IN
FROM THE SOUTH AND SOUTHWEST.
REGARDING THAT LOW...SATELLITE IMAGERY LOCATES IT AROUND 44N 130W
WHICH ISN`T TOO FAR NORTH OF BUOY 2. LATEST PRESSURE READING AT BUOY
2 WAS AROUND 1012 MB WHICH IS ABOUT 2 MB LOWER THAN THE 18Z NAM AND
12Z GFS/ECMWF SHOW AT THE SAME TIME. NO SURPRISE THAT THE MODELS ARE
RUNNING SLIGHTLY WEAK AND BELIEVE THIS BIAS WILL LIKELY APPLY TO THE
STRENGTH OF THE LOW AS IT APPROACHES THE COAST. IN OTHER
WORDS...EXPECT A SLIGHTLY STRONGER LOW THAN MODELS CURRENTLY
INDICATE. WITH THAT BEING SAID...ALL MODELS ARE SHOWING EITHER A
STEADY PRESSURE OR A WEAKENING LOW AS IT APPROACHES THE COAST WHICH
SHOULD LIMIT THE WIND POTENTIAL SOME. 18Z NAM SHOWS 925 MB WINDS OF
50 TO 55 KT ALONG THE COAST AS THE LOW MAKES LANDFALL WHICH COULD BE
A BIT STRONGER WITH THE EXPECTED STRONGER LOW...SO HAVE UPGRADED THE
COAST TO A HIGH WIND WARNING. HOWEVER WITH 925 MB WINDS ACROSS THE
CENTRAL COAST RANGE PEAKING AT ONLY 40 KT IN THE MODELS AND EVEN 850
MB WINDS ONLY 50 KT...DO NOT THINK THAT AREA WILL SEE HIGH WINDS AND
SO HAVE DROPPED HIGH WIND WATCH THERE. THE WIND ADVISORY IN THE
CENTRAL AND SOUTH VALLEY STILL LOOKS GOOD...ESPECIALLY WITH MODELS
TRENDING SLIGHTLY NORTHWARD WITH THE LOW TRACK. EXPECT WINDS TO PICK
UP ON THE COAST STARTING SHORTLY AFTER 00Z AND THEN HIT THE SOUTH
VALLEY STARTING AROUND 04Z AND THEN SPREAD NORTH. WINDS SHOULD BE
DONE ALONG THE COAST SHORTLY AFTER THE LOW MAKES LANDFALL WHICH
CURRENTLY LOOKS LIKE 06Z-ISH...ABOUT 3 HOURS EARLIER THAN PREVIOUS
MODEL RUNS.
THE OTHER ISSUE OVER THE NEXT 12 TO 24 HOURS IS CASCADE SNOW. MODELS
CONTINUE TO TREND HIGHER WITH SNOW LEVELS SO IT LOOKS LIKE SNOW IN
THE LANE COUNTY CASCADES WILL LIKELY BE LIMITED TO ABOVE 4000
FT...BUT THAT`S STILL LOW ENOUGH TO GET SIGNIFICANT ACCUMULATION AT
PASS LEVEL. ELSEWHERE SNOW LEVELS WILL BE A BIT LOWER...CLOSER TO
3500 FT IN THE NORTH OREGON AND SOUTH WASHINGTON CASCADES. DID NOT
SEE ANY NEED TO FURTHER ADJUST SNOW AMOUNTS BUT HAVE OBVIOUSLY
LIMITED LOWER ELEVATION AMOUNTS WITH RISE IN SNOW LEVELS. PEAK SNOW
LOOKS LIKE IT WILL OCCUR FROM LATE EVENING TODAY THROUGH THE
PRE-SUNRISE HOURS TUESDAY BEFORE TAPERING OFF BY MID MORNING. STRONG
WINDS WILL ALSO AFFECT THE CASCADES AND WILL LIKELY PRODUCE SOME
BLOWING SNOW CONDITIONS TONIGHT.
THE LOW WILL MOVE EAST OF THE CASCADES TUESDAY MORNING WITH
DECREASING SHOWERS AND WIND ACROSS OUR AREA ON TUESDAY. AN UPPER
RIDGE IS FORECAST TO BEGIN BUILDING OFF THE COAST TUESDAY...BUT NOT
BEFORE A WARM FRONT SPREADS SOME MORE AREAS OF RAIN AND MOUNTAIN SNOW
INTO SOUTHWEST WASHINGTON AND PARTS OF NORTHWEST OREGON TUESDAY NIGHT
AND WEDNESDAY. AS IT MOVES THROUGH...SNOW LEVELS WILL BEGIN TO
RISE...ESPECIALLY ON WEDNESDAY. HIGH PRESSURE FINALLY LOOKS LIKE IT
WILL TAKE HOLD ON THURSDAY WITH SUNNY SKIES AND WARM TEMPERATURES. WE
COULD SEE OUR FIRST WIDESPREAD 70 DEGREE TEMPERATURES IN THE VALLEY
THURSDAY. BOWEN/TOLLESON
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...A LOW PRESSURE SYSTEM
IS FORECAST TO RIDE OVER THE CREST OF THE RIDGE OF HIGH PRESSURE IN
PLACE OVER THE PACIFIC NORTHWEST ON FRIDAY. THE QUESTION IS HOW FAR
SOUTH THIS WILL MAKE IT AS IT MOVES ONSHORE. THE MODELS HAVE BEEN
FLIP-FLOPPING A BIT ON WHETHER IT WILL MAKE IT DOWN TO CLIP
SOUTHWEST WASHINGTON/FAR NORTHWEST OREGON OR NOT. AS OF NOW...THE
GFS IS SHOWING A CHANCE OF RAIN MAKING IT DOWN TO THE FAR NORTHERN
PORTION OF OUR AREA...BUT THE LAST FEW RUNS HAVE BEEN KEEPING IT
FURTHER NORTH.WE HAVE INTRODUCED A SLIGHT CHANCE OF RAIN FOR THIS
NORTHERN PORTION OF OUR AREA FOR FRIDAY NIGHT TO SHOW THIS
UNCERTAINTY. FOR SATURDAY WE GET INTO SOUTH-SOUTHWESTERLY FLOW WITH
HIGH PRESSURE TO OUR NORTH AND A BROAD LOW OVER THE SOUTHWESTERN US.
THIS BRINGS MOISTURE UP FROM THE SOUTH PACIFIC WHICH IS A PATTERN
FAVORABLE FOR SHOWERS IN THE CASCADES. THIS SSWLY FLOW ONLY
INCREASES ON SUNDAY AS A THERMAL LOW DEVELOPS OVER NORTHERN
CALIFORNIA. THIS WILL KEEP A CHANCE OF SHOWERS IN THE CASCADES
THROUGH SUNDAY. MODELS ARE SUGGESTING A WEAK FRONT WILL MOVE THROUGH
EARLY NEXT WEEK WHICH BRINGS US ANOTHER CHANCE OF RAIN ACROSS THE
AREA MONDAY AND TUESDAY. -MCCOY
&&
.AVIATION...AN UNSTABLE AIR MASS WILL CONTINUE TO BRING SHOWERY
CONDITIONS THIS EVENING. HOWEVER...AS LOW PRESSURE APPROACHES
THE OREGON COAST THESE SHOWERS WILL TURN TO RAIN AND SPREAD
INLAND OVERNIGHT. THIS WILL BRING MAINLY MVFR CIGS AND VSBYS TO
ALL TAF SITES THROUGH 16Z TUESDAY. AS THE LOW PRESSURE PUSHES
ASHORE AND INLAND...SOUTH WIND GUSTS OF 50 KT AT KONP AND 40 KT AT
KSLE AND KEUG APPEAR POSSIBLE FOR A 2 TO 4 HOUR PERIOD THROUGH 10Z
TUESDAY. CONDITIONS SHOULD TREND TOWARDS VFR AT THESE TAF SITES
WITH THE STRONGER SOUTH WINDS...PARTICULARLY AT KSLE AND KEUG.
CONDITIONS SHOULD IMPROVE TO VFR AT ALL TAF SITES AFTER 18Z
TUESDAY.
KPDX AND APPROACHES...AN UNSTABLE AIR MASS WILL CONTINUE TO BRING
SHOWERS AND RAIN OVERNIGHT UNDER MOSTLY VFR CONDITIONS. THERE MAY
BE A MORE EXTENDED PERIOD OF MVFR CONDITIONS TONIGHT AS THE LOWER
ATMOSPHERE STABILIZES AND WINDS RELAX...PRIMARILY BETWEEN 06Z AND
15Z TUESDAY. /NEUMAN/64
&&
.MARINE...LOW PRESSURE CONTINUES TO MOVE EASTWARD TOWARDS THE
NORTH OREGON COAST...WITH GALE FORCE GUSTS OVER THE CENTRAL OREGON
WATERS. MODELS AND SATELLITE IMAGERY CONTINUE TO SUGGEST THAT THE
SYSTEM WILL MAKE LANDFALL NEAR CAPE FOULWEATHER WITHIN THE NEXT FEW
HOURS...WITH WINDS FALLING BELOW 21 KT SHORTLY THEREAFTER. THE
STRONGEST WINDS ARE EXPECTED TO REMAIN SOUTH OF THE LOW PRESSURE
TRACK. SEAS WILL LIKELY CLIMB INTO THE LOW TEENS NEAR THE
STRONGEST WINDS OVER THE CENTRAL WATERS. HOWEVER...THE NORTHERN
WATERS WILL LIKELY ONLY EXPERIENCE A BRIEF RISE ABOVE 10 FT
TONIGHT AS THE WINDS LOOK TO NOT BE QUITE SO STRONG. /64/NEUMAN
REST OF THE PREVIOUS DISCUSSION FOLLOWS...INCREASING HIGH PRESSURE
WILL BRING A BREAK IN THE WINDS AND ALLOW SEAS TO RELAX TUESDAY.
HOWEVER...A WEAK FRONT WILL PUSH INTO THE WATERS TUESDAY NIGHT AND
WEDNESDAY MORNING. THIS SHOULD PRODUCE SMALL CRAFT ADVISORY LEVEL
SOUTH WINDS OF 25 KT ACROSS THE WATERS...PARTICULARLY OVER THE
NORTHERN OUTER WATERS DURING THIS PERIOD.
HIGH PRESSURE OVER THE NORTHEAST PACIFIC AND THERMAL LOW PRESSURE
OVER NORTHERN CALIFORNIA WILL THEN ARRIVE LATE THIS WEEK AND OVER
THE WEEKEND...AND PRODUCE A MORE SUMMER-LIKE NORTHERLY WIND
PATTERN. A WEAK FRONT COULD TEMPORARILY ENHANCE WIND GUSTS ACROSS
THE WATERS ON FRIDAY. /NEUMAN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 5 AM PDT TUESDAY FOR CENTRAL WILLAMETTE
VALLEY-SOUTH WILLAMETTE VALLEY.
WINTER WEATHER ADVISORY UNTIL 7 AM PDT TUESDAY FOR CASCADES
IN LANE COUNTY-NORTHERN OREGON CASCADES.
HIGH WIND WARNING UNTIL 3 AM PDT TUESDAY FOR CENTRAL OREGON
COAST.
WA...WINTER WEATHER ADVISORY UNTIL 7 AM PDT TUESDAY FOR SOUTH
WASHINGTON CASCADES.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 3 AM PDT TUESDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 AM PDT
TUESDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
CASCADE HEAD OR OUT 60 NM.
GALE WARNING UNTIL 2 AM PDT TUESDAY FOR COASTAL WATERS FROM
CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
11 PM PDT THIS EVENING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 AM
TO 10 AM PDT TUESDAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 6 PM
TO 11 PM PDT TUESDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
750 PM EDT MON MAR 23 2015
.SYNOPSIS...
A WEAK AND FAST MOVING ALBERTA CLIPPER WILL BRING LIGHT SNOW TO
SOUTHERN PARTS OF THE FORECAST AREA TONIGHT. LOW PRESSURE MOVING
TO OUR NORTH WILL BRING MILDER TEMPERATURES WITH A FEW PERIODS OF
RAIN FOR WEDNESDAY INTO THURSDAY. MUCH COOLER AND DRIER CONDITIONS
WILL RETURN FOR FRIDAY THROUGH SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
CLOUDS RAPIDLY OVERSPREADING CENTRAL PA THIS EVENING IN ADVANCE
OF APPROACHING CLIPPER. UPSTREAM RADAR/SFC OBS...COMBINED WITH
NEAR TERM MDL DATA...SUPPORT INCREASING POPS TO NEAR 100 PCT
ACROSS THE LAUREL HIGHLANDS TONIGHT. BASED ON INPUT OF LATEST
HRRR/4KM NAM...HAVE EXPANDED THE AREAL COVERAGE OF MEASURABLE SNOW
A BIT...BUT OVERALL QPF HASN/T INCREASED APPRECIABLY. STILL
FAVORING ACCUMS FROM 1-3 INCHES ACROSS THE LAUREL HIGHLANDS OF
SOMERSET/CAMBRIA COUNTIES...TO A COATING ACROSS THE CENTRAL MTNS
AND PORTIONS OF THE LOWER SUSQ VALLEY.
RADAR AND HRRR OUTPUT SUGGEST SNOW SHOULD REACH THE LAUREL
HIGHLANDS BTWN 00Z-02Z BEFORE SPREADING EAST ACROSS THE REMAINDER
OF SOUTHERN PA OVERNIGHT. MID LVL SHORTWAVE AND BULK OF LG SCALE
FORCING SHOULD BE PUSHING EAST OF THE AREA SHORTLY AFTER
06Z...CAUSING SNOW TO TAPER OFF LATE TONIGHT.
LOWS WILL ONCE AGAIN BE WELL BELOW NORMAL TONIGHT...RANGING FROM
THE MID TEENS OVER THE FAR NORTH TO MID 20S OVER THE SOUTH.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
SPOTTY LIGHT SNOW COULD LINGER DURING THE MORNING OVER SOUTHERN
SECTIONS IN THE INVERTED SURFACE TROUGH AND LOW LEVEL UPSLOPE
FLOW SOUTH OF THE HIGH THAT WILL BE NORTH OF NEW YORK. CLEARING
SKIES SHOULD WORK SOUTHWARD DURING THE AFTN/EARLY EVENING...AS SFC
HIGH AND ASSOC LOW PWAT AIR MASS OVR THE E GRT LKS BUILDS IN.
CLOUD COVER AND LACK OF MIXING WILL RESULT IN ANOTHER COOL DAY
FOR LATE MARCH WITH TEMPS LIKELY ONLY REACHING THE U30S TO L40S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
FAIRLY ZONAL FLOW...BUT SOMEWHAT BUMPY IN THE NORTHERN
STREAM...WILL HOLD THROUGH THE EARLY PART OF THE LONG TERM PERIOD.
SOME OF THIS ENERGY IS FORECAST TO LEAD TO AMPLIFICATION OF AN
UPPER TROF OVER THE NORTHERN PLAINS MID WEEK...AND AN EVEN DEEPER
UPPER TROF OVER EASTERN U.S. BY LATE IN THE WEEK. THIS AMPLIFYING
PATTERN HOWEVER IS FORECAST TO REMAIN PROGRESSIVE.
THE DEVELOPING TROF WILL BRING A WARM FRONT/COLD FRONT COMBO
ACROSS PA WED INTO THURSDAY. AHEAD OF THE COLD FRONT...TEMPS
SHOULD CLIMB INTO THE 50S AND 60S...LEVELS NOT SEEN SINCE LAST
FALL. ANOTHER TUMBLE IN TEMPS IS EXPECTED BEHIND THE SYSTEM FOR
LATE IN THE WEEK.
EXPANSIVE AREA OF HIGH PRESSURE WILL BUILD INTO THE REGION BEHIND
THIS SYSTEM WITH SEVERAL DRY DAYS INTO NEXT WEEKEND. ANOTHER COLD
FRONT WILL MOVE THROUGH LATE SUNDAY INTO NEXT MONDAY BRINGING
ANOTHER RETURN TO CHILLY TEMPS AS WELL AS THE CHANCE FOR MORE
SNOW SHOWERS.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
MADE A FEW MORE CHANGES TO THE 00Z TAFS.
JUST HIGH CLDS OUTSIDE THE OFFICE...BUT THICKER CLDS JUST
TO THE WEST. VERY FAST MOVING SYSTEM MOVING SE TOWARD CENTRAL
PA.
A WEAK SYSTEM TRACKING ESEWD FROM THE MIDWEST/OH VALLEY WILL
BRING A PERIOD OF LIGHT SNOW AND REDUCED VIS/CIGS TO THE SWRN HALF
OF THE LOCAL FLYING AREA FROM THIS EVENING INTO EARLY TUESDAY
MORNING.
THE LOWER CIGS/VIS WILL LINGER INTO TUESDAY MORNING FROM JST-AOO
SOUTHWARD...BEFORE GRADUALLY IMPROVING LATER TUES MORNING.
EXPECT VFR BY TUESDAY AFTERNOON AS HIGH PRES MIGRATES ACROSS THE
AIRSPACE.
OUTLOOK...
WED-FRI...PERIODS OF RAIN AND MVFR/IFR CONDITIONS.
SAT...MAINLY VFR...PERHAPS A BRIEF PERIOD OF MVFR
ACROSS THE WEST AND NW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1019 AM EDT SUN MAR 22 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE WILL BUILD SOUTHEAST ACROSS THE
GREAT LAKES. THIS WILL MAINTAIN BELOW NORMAL TEMPERATURES AND DRY
CONDITIONS THROUGH TUESDAY. LOW PRESSURE MOVING TO OUR NORTH WILL
BRING UNSETTLED CONDITIONS WITH THE CHANCE OF RAIN DURING THE
SECOND PART OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WEAK SECONDARY FRONT/ARCTIC BOUNDARY IS DROPPING SLOWLY SOUTH
THROUGH SRN NY. THE SURFACE WIND FIELD SHOWS A TIDY AREA OF
LOCALIZED CONVERGENCE THAT REFLECTS NICELY IN THE VISUAL CLOUD
AND RADAR REFLECTIVITY FIELDS. OBSERVATIONS SHOW BRIEF VISIBILITY
REDUCTIONS TO A MILE OR LESS INDICATING THE SNOW SHOWERS COULD
ACTUALLY BE WHITENING THE GROUND IN A FEW SPOTS. THE HRRR CAPTURES
THIS EXTREMELY SMALL FEATURE AND WEAKENS IT CONSIDERABLY AS IT
DROPS INTO NRN PA. REGARDLESS...HAVE PUT FLURRIES IN THE FORECAST
TO ACCOUNT FOR THIS HOPEFULLY DYING FEATURE AS IT MEANDERS INTO
MY FCST AREA.
THAT PRETTY MUCH SUMS UP THE NEAR TERM CHALLENGE. OTHER THAN THE
CLOUDS DROPPING INTO NRN PA...THE REMAINDER OF THE REGION IS
BRIGHT AND SUNNY BUT CHILLY.
22/00Z GEFS 8H NEGATIVE TEMP ANOMALIES OF MINUS 1-2 SIGMA
INDICATE IT WILL BE A VERY CHILLY DAY FOR LATE MARCH. THE GREATEST
TEMPS ANOMALIES CONTINUE TO LIE ACROSS THE NRN MTNS...WHERE MAX
TEMPS OF ONLY THE MID-UPPER U20S ARE EXPECTED. SOME OF THE
SOUTHERN VALLEYS NEAR THE MASON-DIXON LINE WILL LIKELY REACH THE
L40S...WHICH IS STILL ABOUT 10 DEG BELOW NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
1030 MB HIGH PRESSURE WILL DRIFT SE AND BECOME LOCATED JUST NORTH
OF LAKE ONTARIO EARLY MONDAY. DRY AND UNSEASONABLY CHILLY
CONDITIONS WILL OCCUR DURING THIS 24 HOUR PERIOD...WITH GENERALLY
CLEAR TO PARTLY CLOUDY SKIES AND A 5-8 KT NW SFC WIND.
LOW TEMPS TONIGHT WILL VARY FROM 10-15F ACROSS THE NORTHERN
MTNS...TO BETWEEN 20 AND 25F THROUGHOUT THE SRN VALLEYS OF THE
STATE.
HIGHS MONDAY WILL BE NEAR TO SLIGHTLY HIGHER THAN TODAY/S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
LONGITUDINALLY PRONOUNCED SPLIT FLOW PATTERN WILL CONTINUE ACROSS
THE CONTINENTAL US THROUGH THE PERIOD. ZONAL TO SWRLY FLOW IN THE
NRN STREAM WILL DOMINATE MUCH OF THE LONG TERM PERIOD OVER THE
NORTHEASTERN PART OF THE COUNTY...PROVIDING DRY WEATHER EARLY IN
THE PD...UNTIL A STRONG NRN STREAM WAVE...POSSIBLY PHASED WITH
SOUTHERN STREAM ENERGY...ARRIVES MID WEEK.
ARCTIC HIGH WILL BUILD INTO THE REGION BEHIND EXITING COLD FRONT
SUN NIGHT INTO TUESDAY...WITH BELOW NORMAL TEMPS TO START THE
WEEK. TEMPS WILL BEGIN TO MODERATE TUE INTO WED AS FLOW TURNS
FROM THE NW AROUND TO THE SW. DAYTIME TEMPS WILL STRUGGLE TO HIT
30F ACROSS THE NORTHERN MTNS SUN/MON WITH HIGHS ONLY AROUND 40F
ACROSS THE SOUTH /AND LOWS WILL DIP INTO THE TEENS AND 20S FOR
MUCH OF CENTRAL PA/. BY WED...HIGH TEMPS REBOUND INTO THE MID 40S
TO MID 50S.
SHARP RIDGE BUILDS ACROSS FAR WESTERN U.S. LATE WEEK...ALLOWING A
WAVE TO CARVE OUT A TROUGH OVER EASTERN PORTIONS OF THE COUNTRY AS
A LOW PRESSURE AREA BECOMES BETTER ORGANIZED IN THE MIDWEST. COULD
SEE A PASSING SHOWER ON WED AS WARM FRONT SLIDES THROUGH...BUT
MAJORITY OF PRECIP WILL HOLD OFF UNTIL THU/EARLY FRI AS ELONGATED
FRONT/TROUGH MOVE SLOWLY THROUGH THE REGION WITH SURFACE LOW
TRACKING TO OUR NORTH. RAIN CHANCES DURING THAT WINDOW OF TIME
WILL BE IN THE HIGH CHANCE/LOW LIKELY CATEGORY. ECMWF SUITE FASTER
THAN THE GFS WITH THE TROUGH...SO THESE DIFFERENCES WILL NEED TO
BE RESOLVED IN FUTURE RUNS TO INCREASE FORECAST CONFIDENCE.
BEHIND THAT SYSTEM...A SHOT OF COOLER AIR RETURNS BRINGING ANOTHER
PERIOD OF BELOW NORMAL TEMPS AND SCT MAINLY LIGHT RAIN/SNOW
SHOWERS FOR LATER FRI INTO THE WEEKEND.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
SOME LOCALIZED MVFR CONTINUES TO AFFECT BFD AS SOME LAKE MOISTURE
AND FLURRIES DROP INTO THE AREA. OTHERWISE VFR CONDITIONS WILL
PREVAIL AT MOST SITES THROUGH THE PERIOD. SFC WINDS FROM 300-330
AT 10KTS MAY GUST UP TO 20KT AT TIMES THIS AFTN BEFORE DECREASING
AFT 00Z.
HIGH PRESSURE WILL CONTINUE TO PROMOTE FAIR/DRY WX AND VFR FLYING
EARLY THIS WEEK.
OUTLOOK...
MON-TUE...VFR/NO SIG WX.
WED-THU...RESTRICTIONS PSBL/CHC OF RAIN WITH NEXT FRONTAL SYSTEM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...FITZGERALD/LA CORTE/LAMBERT
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/STEINBUGL
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
803 PM CDT MON MAR 23 2015
.UPDATE...
ISSUED AT 752 PM CDT MON MAR 23 2015
FOR NOW NOT PLANNING ANY MAJOR CHANGES TO THE FORECAST. BAND OF
WAA RAIN CURRENTLY MAKING ITS WAY INTO SOUTHWEST CWA. BASED ON
MODEL DATA AND LATEST SOUNDINGS ITS FAIR TO SAY I AM NOT SURE HOW
FAST/FAR THAT BAND WILL TRACK NORTHEAST. MAY NOT GET MUCH IN THE
WAY OF MEASURABLE PCPN IN THE NORTHEAST CWA UNTIL MORE ENERGY
COMES OUT ON TUESDAY. WILL CONTINUE TO WATCH THE ADVANCEMENT OF
RAIN THIS EVENING AND THEN DETERMINE ANY CHANGES THAT MIGHT NEED
TO BE MADE CONCERNING POPS..ETC. LOW TEMPERATURES LOOK MOSTLY ON
TARGET GIVEN OVERNIGHT CLOUDS AND LLJ.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 346 PM CDT MON MAR 23 2015
STRATUS DECK CONTINUES TO ERODE QUICKLY FROM SOUTHWEST TO
NORTHEAST ACROSS THE EASTERN CWA WITH TEMPS QUICKLY CLIMBING AS
THE SUN EMERGES. SNOWFALL FROM YESTERDAY WILL BE HISTORY FOR SOME
AREAS. ONCE AGAIN THE HRRR LOW-LEVEL CLOUD COVER PRODUCT PERFORMED
EXTREMELY WELL IN ERODING THE STRATUS DECK THIS AFTERNOON.
ATTENTION THEN TURNS TO THE STORM SYSTEM MOVING IN TONIGHT.
SHOWERS ARE ALREADY NOTED ACROSS SOUTHWEST SD AND APPROACHING THE
SOUTHWEST CWA. MODELS ARE COMING INTO BETTER AGREEMENT WITH A
DRIER SOLUTION OVER THE CWA. THAT SAID THOUGH...IT STILL APPEARS A
BAND OF WARM AIR ADVECTION RAINFALL WILL MOVE EASTWARD ACROSS THE
AREA LATE TONIGHT AND THROUGH THE DAY TUESDAY. ITS A QUESTION OF
JUST HOW FILLED IN AND INTENSE THIS BAND WILL BE. BACKED OFF ON
QPF A BIT THOUGH AS MODELS ARE RATHER LIGHT WITH ITS QPF OUTPUT.
OVERALL FORCING IS MODEST. COULD STILL BE DEALING WITH MIXED
PRECIP ACROSS THE EASTERN CWA LATE TONIGHT AND THROUGH THE DAY
TUESDAY. MODELS ALL SHOWING A DRY SLOT MOVING INTO THE WESTERN CWA
TUESDAY AFTERNOON...WITH BREEZY WEST TO NORTHWEST WINDS AND DRYING
CONDITIONS. RH VALUES WILL LIKELY FALL INTO THE 20S ACROSS THE
SOUTHWEST CWA ONCE AGAIN. TEMPS WILL WARM NICELY IN THE DRY
SLOT...ESPECIALLY OVER THE SOUTHWEST CWA AND MAY HAVE TO BUMP UP
HIGHS A FEW MORE DEGREES.
AS THE LOW PASSES TO THE EAST ON WEDNESDAY...STRONG NORTHWEST
WINDS DEVELOP. COULD BE CLOSE TO WIND ADVISORY LEVELS SO WILL HAVE
TO KEEP AN EYE ON THAT. WILL ALSO HAVE TO WATCH WRAP AROUND PRECIP
POTENTIAL ON THE BACK SIDE OF THE LOW. THERE ARE DISCREPANCIES IN
JUST HOW FAR SOUTH PRECIP WILL MAKE IT...WITH THE GFS THE FURTHEST
SOUTH THROUGH MUCH OF NORTHEAST SD AND WEST CENTRAL MN. THE EC
DOES NOT TAKE IT MUCH SOUTH OF THE ND/SD BORDER. GENERALLY WENT
WITH THE MORE RELIABLE EC AT THIS POINT. INTERESTING TO NOTE
THOUGH THAT THIS TIME AROUND THE GEM IS IN AGREEMENT WITH THE GFS.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 346 PM CDT MON MAR 23 2015
UPPER LEVEL PATTERN WILL TRANSITION FROM NORTHWEST FLOW TO A FLAT
RIDGE WITH SEVERAL WAVES PASSING THROUGH. THIS WILL RESULT IN
FLUCTUATING TEMPS THROUGH THE PERIOD. PATTERN DOES LOOK MOSTLY
DRY AS BEST UPPER ENERGY REMAINS NORTH OF THE STATE. TEMPS WILL
BE COOLEST ON THURSDAY...WITH A WARMING TREND INTO
SATURDAY...WHERE TEMPS WILL BE ABOVE NORMAL MOST LOCATIONS...ALONG
AND WEST OF THE MISSOURI RIVER. A STRONGER WAVE CRASHES THROUGH
THE RIDGE ON SATURDAY NIGHT BRINGING BREEZY CONDITIONS AND COOLER
TEMPS FOR SUNDAY...THEN A REBOUND OF TEMPS AGAIN FOR MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 622 PM CDT MON MAR 23 2015
VFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE NIGHT AT ALL
TERMINALS. HOWEVER AN ADVANCING SYSTEM WILL BRING RAIN SHOWERS TO
THE REGION THROUGH TUESDAY. ACCOMPANYING THAT RAIN WILL BE LOWERED
CIGS...PROBABLY MOSTLY IN THE MVFR RANGE. LIGHT FOG WILL ALSO BE
POSSIBLE WITH THE LOWERED CIGS AND PCPN.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TDK
SHORT TERM...TMT
LONG TERM...SCARLETT
AVIATION...TDK
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
625 PM CDT MON MAR 23 2015
.UPDATE...
ISSUED AT 622 PM CDT MON MAR 23 2015
THE AVIATION DISCUSSION HAS BEEN UPDATED BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 346 PM CDT MON MAR 23 2015
STRATUS DECK CONTINUES TO ERODE QUICKLY FROM SOUTHWEST TO
NORTHEAST ACROSS THE EASTERN CWA WITH TEMPS QUICKLY CLIMBING AS
THE SUN EMERGES. SNOWFALL FROM YESTERDAY WILL BE HISTORY FOR SOME
AREAS. ONCE AGAIN THE HRRR LOW-LEVEL CLOUD COVER PRODUCT PERFORMED
EXTREMELY WELL IN ERODING THE STRATUS DECK THIS AFTERNOON.
ATTENTION THEN TURNS TO THE STORM SYSTEM MOVING IN TONIGHT.
SHOWERS ARE ALREADY NOTED ACROSS SOUTHWEST SD AND APPROACHING THE
SOUTHWEST CWA. MODELS ARE COMING INTO BETTER AGREEMENT WITH A
DRIER SOLUTION OVER THE CWA. THAT SAID THOUGH...IT STILL APPEARS A
BAND OF WARM AIR ADVECTION RAINFALL WILL MOVE EASTWARD ACROSS THE
AREA LATE TONIGHT AND THROUGH THE DAY TUESDAY. ITS A QUESTION OF
JUST HOW FILLED IN AND INTENSE THIS BAND WILL BE. BACKED OFF ON
QPF A BIT THOUGH AS MODELS ARE RATHER LIGHT WITH ITS QPF OUTPUT.
OVERALL FORCING IS MODEST. COULD STILL BE DEALING WITH MIXED
PRECIP ACROSS THE EASTERN CWA LATE TONIGHT AND THROUGH THE DAY
TUESDAY. MODELS ALL SHOWING A DRY SLOT MOVING INTO THE WESTERN CWA
TUESDAY AFTERNOON...WITH BREEZY WEST TO NORTHWEST WINDS AND DRYING
CONDITIONS. RH VALUES WILL LIKELY FALL INTO THE 20S ACROSS THE
SOUTHWEST CWA ONCE AGAIN. TEMPS WILL WARM NICELY IN THE DRY
SLOT...ESPECIALLY OVER THE SOUTHWEST CWA AND MAY HAVE TO BUMP UP
HIGHS A FEW MORE DEGREES.
AS THE LOW PASSES TO THE EAST ON WEDNESDAY...STRONG NORTHWEST
WINDS DEVELOP. COULD BE CLOSE TO WIND ADVISORY LEVELS SO WILL HAVE
TO KEEP AN EYE ON THAT. WILL ALSO HAVE TO WATCH WRAP AROUND PRECIP
POTENTIAL ON THE BACK SIDE OF THE LOW. THERE ARE DISCREPANCIES IN
JUST HOW FAR SOUTH PRECIP WILL MAKE IT...WITH THE GFS THE FURTHEST
SOUTH THROUGH MUCH OF NORTHEAST SD AND WEST CENTRAL MN. THE EC
DOES NOT TAKE IT MUCH SOUTH OF THE ND/SD BORDER. GENERALLY WENT
WITH THE MORE RELIABLE EC AT THIS POINT. INTERESTING TO NOTE
THOUGH THAT THIS TIME AROUND THE GEM IS IN AGREEMENT WITH THE GFS.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 346 PM CDT MON MAR 23 2015
UPPER LEVEL PATTERN WILL TRANSITION FROM NORTHWEST FLOW TO A FLAT
RIDGE WITH SEVERAL WAVES PASSING THROUGH. THIS WILL RESULT IN
FLUCTUATING TEMPS THROUGH THE PERIOD. PATTERN DOES LOOK MOSTLY
DRY AS BEST UPPER ENERGY REMAINS NORTH OF THE STATE. TEMPS WILL
BE COOLEST ON THURSDAY...WITH A WARMING TREND INTO
SATURDAY...WHERE TEMPS WILL BE ABOVE NORMAL MOST LOCATIONS...ALONG
AND WEST OF THE MISSOURI RIVER. A STRONGER WAVE CRASHES THROUGH
THE RIDGE ON SATURDAY NIGHT BRINGING BREEZY CONDITIONS AND COOLER
TEMPS FOR SUNDAY...THEN A REBOUND OF TEMPS AGAIN FOR MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 622 PM CDT MON MAR 23 2015
VFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE NIGHT AT ALL
TERMINALS. HOWEVER AN ADVANCING SYSTEM WILL BRING RAIN SHOWERS TO
THE REGION THROUGH TUESDAY. ACCOMPANYING THAT RAIN WILL BE LOWERED
CIGS...PROBABLY MOSTLY IN THE MVFR RANGE. LIGHT FOG WILL ALSO BE
POSSIBLE WITH THE LOWERED CIGS AND PCPN.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TDK
SHORT TERM...TMT
LONG TERM...SCARLETT
AVIATION...TDK
AREA FORECAST DISCUSSION
NWS PORTLAND
245 PM PDT SUN MAR 22 2015
.SYNOPSIS...A COLD FRONT IS MOVING ACROSS THE AREA THIS EVENING.
COOLER AND MORE SHOWERY WEATHER EXPECTED TONIGHT AND MONDAY AS A
COLDER TROUGH MOVES OVER THE PACIFIC NW. THUNDERSTORMS ARE
POSSIBLE WITH THESE SHOWERS AS WELL AS THE LOWERING OF SNOW LEVELS...
AND ACCUMULATING SNOW AT THE CASCADE PASSES. ANOTHER DISTURBANCE
WILL MOVE THROUGH MONDAY NIGHT AND TUESDAY FOR MORE MORE RAIN AND
A BETTER CHANCE FOR MOUNTAIN SNOW. A WARM FRONT WILL BRUSH THE AREA
TUESDAY NIGHT AND WEDNESDAY AS AN UPPER RIDGE BUILDS OFFSHORE. THE
UPPER RIDGE WILL MOVE ONSHORE WEDNESDAY NIGHT AND THURSDAY AND
POSSIBLY CONTINUE THROUGH NEXT WEEKEND.
&&
.SHORT TERM...TONIGHT THROUGH WEDNESDAY...A COLD FRONT IS SPREADING
LIGHT RAIN ACROSS NW OR AND SW WA THIS AFTERNOON AND EVENING. SNOW
LEVELS IS BETWEEN 5500 AND 6000 FEET THIS AFTERNOON...BUT WILL LOWER
TO BETWEEN 4000 AND 5000 FEET BEHIND THE FRONT TONIGHT. SHOWERS WILL
DECREASE WHEN THE COLDER AIR ARRIVES...BUT ELEVATIONS ABOVE 4500 FEET
MAY SEE A COUPLE OF INCHES OF NEW SNOW.
COLDER AND MORE UNSTABLE AIR MOVES IN LATE TONIGHT AS A NEGATIVELY
TILTED UPPER TROUGH APPROACHES. THIS TROUGH WILL ENHANCE SHOWERS THAT
MAY HAVE SOME THUNDERSTORMS EMBEDDED IN THEM. THERE HAS BEEN A COUPLE
OF LIGHTNING STRIKES DETECTED IN SHOWERS NEAR THIS TROUGH THIS
AFTERNOON. SNOW LEVELS WILL LOWER EVEN MORE WHEN THE TROUGH MOVES
OVER THE AREA MONDAY MORNING...AND ARE EXPECTED TO DROP TO BETWEEN
3000 AND 4000 FEET. SHOWERS FROM THIS TROUGH WILL PERSIST THROUGH
MONDAY AFTERNOON AND LIGHT SNOW ACCUMULATIONS OF 1 TO 3 INCHES.
THE THIRD SYSTEM WILL BE A LITTLE MORE INTERESTING AS MODELS ARE
FORECASTING A 1012 MB SURFACE LOW TO MOVE ONTO THE CENTRAL OREGON
COAST MONDAY NIGHT.THERE WILL BE MOVE AVAILABLE MOISTURE WITH THIS
SYSTEM WITH MODELS FORECASTING LAYERED PRECIPITABLE WATER VALUES JUST
UNDER AN INCH. THE SNOW LEVELS WILL STILL BE ON THE LOW SIDE...AROUND
3500 FEET AND THE CASCADES WILL HAVE A BETTER CHANCE FOR MORE
ACCUMULATING SNOW MONDAY NIGHT.
THE CURRENT TRACK OF THIS LOW SUGGESTS THAT THE QPF WILL BE GREATER
FOR AREAS SOUTH OF SALEM...AND EXPECT THE CENTRAL AND NORTHERN OREGON
CASCADES TO SEE HIGHER SNOW ACCUMULATIONS THAN THE SOUTH WASHINGTON
CASCADES. 4 TO 10 INCHES OF NEW SNOW ARE POSSIBLE FOR THE OREGON
CASCADES FROM MONDAY EVENING THROUGH TUESDAY MORNING...AND 2 TO 6
INCHES FOR THE SOUTH WASHINGTON CASCADES. ARE POSSIBLE DOWN TO OR
JUST BELOW THE CASCADE PASSES.
THE LOW WILL PUSH EAST OF THE CASCADES LATE TUESDAY MORNING AND
SHOWERS WILL QUICKLY END. SNOW LEVELS WILL RAPIDLY RISE TUESDAY AS A
WARM FRONT BRUSHES JUST WEST OF OREGON. THE TAIL END OF THE WARM
FRONT WILL BRUSH OVER SW WASHINGTON TUESDAY NIGHT AND WEDNESDAY.
AVAILABLE MOISTURE WILL REMAIN HIGH WITH THIS WARM FRONT. THE MODELS
CURRENTLY FORECAST THAT MOST OF THE MOISTURE AND RESULTANT RAIN WILL
REMAIN NORTH OF THE PORTLAND FORECAST AREA...BUT EXTREME SW
WASHINGTON MAY GET CLIPPED WITH HEAVY RAIN TUESDAY NIGHT THROUGH
WEDNESDAY. TJ
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...A RIDGE OF HIGH
PRESSURE STARTS TO BUILD OVER THE PACNW WEDNESDAY NIGHT...PUSHING
ANY LINGERING SHOWERS OFF TO THE EAST AND OUT OF OUR AREA BY
THURSDAY MORNING. THERE HAS BEEN SIGNIFICANT INCONSISTENCY ON HOW
STRONG THIS RIDGE GETS BETWEEN MODEL RUNS AND THIS INCREASES
UNCERTAINTY FOR OUR WEATHER THROUGH THE EXTENDED PERIOD. MODELS HAVE
GENERALLY BEEN FORECASTING A FAIRLY SIGNIFICANT RIDGE BUILDING
BRINGING BACK AN DRY WARM WEATHER THROUGH THE END OF THE
WEEKEND...SO HAVE LEANED TOWARD THIS SCENARIO. THERE IS A CHANCE
THAT THE LOW PRESSURE SYSTEM THAT RIDES OVER THE RIDGE AS IT MOVES
ON-SHORE FRIDAY NIGHT OR EARLY SATURDAY COULD DROP FURTHER SOUTH
BRINGING RAIN BACK TO OUR AREA FOR SATURDAY. EITHER WAY...THE RIDGE
LOOKS LIKELY TO REBUILD OVER THE PACNW SUNDAY INTO MONDAY. -MCCOY
&&
.AVIATION...COLD FRONT HAS PASSED THE COAST AND WILL CONTINUE TO
MOVE INLAND THIS AFTERNOON AND EVENING. EXPECT SCATTERED SHOWERS
TO CONTINUE TO BRIEF SPURTS OF MVFR CIG AND/OR VIS THROUGH THE
EVENING. IT STILL LOOKS LIKE THERE ARE SOME SHOWERS OFFSHORE SO
RAIN REMAINS LIKELY AT COASTAL SITES WITH EVEN A RUMBLE OF
THUNDER POSSIBLE. ANOTHER SYSTEM WILL BRING MORE RAIN AND LIKELY
MVFR CONDITIONS TONIGHT STARTING AT THE COAST AND MOVING INLAND
DURING THE OVERNIGHT HOURS. A SLIGHT THUNDER THREAT WILL EXPAND
INLAND OVERNIGHT AND LAST THROUGH MONDAY AFTERNOON. HOWEVER
CONFIDENCE IS TOO LOW FOR INLAND AREAS TO INCLUDE IN THE TAF AT
THIS POINT.
KPDX AND APPROACHES...VFR CONDITIONS PREVAILING WITH POSSIBLE
TEMPO MVFR CONDITIONS THROUGH ABOUT 01Z. CHANCE OF MVFR CONDITIONS
INCREASES AGAIN LATE TONIGHT AND EARLY MONDAY MORNING WITH RETURN
OF SHOWERS.
&&
.MARINE...TODAY`S FRONT DID`T PACK QUITE AS MUCH PUNCH AS
ORIGINALLY THOUGHT WITH WINDS GENERALLY REMAINING BELOW 20 KT.
WITH FRONT ONSHORE AT THIS POINT...PEAK WINDS SHOULD HAVE ALREADY
OCCURRED AND WITH RECENT ASCAT PASS SHOWING WINDS LESS THAN 20
KT...HAVE KILLED ALL SMALL CRAFT ADVISORIES FOR TODAY. WITH LESSER
WINDS...SEAS ARE ONLY RUNNING 5 TO 6 FT AND SHOULD ONLY INCREASE
SLIGHTLY TO MAYBE 7 FT OVERNIGHT.
ANOTHER SYSTEM APPROACHES THE WATERS BEGINNING TONIGHT WITH WINDS
INCREASING MAINLY OVER THE CENTRAL OREGON WATERS. ISSUED A SMALL
CRAFT ADVISORY FOR WINDS BEGINNING 12Z MONDAY WHICH WILL RUN
THROUGH 06Z TUESDAY. NOT AS CONFIDENT AT THIS POINT THAT SMALL
CRAFT WINDS WILL OCCUR OVER THE NORTHER OREGON WATERS...SO HAVE
LEFT THAT AREA OUT FOR NOW. SEAS WILL RISE SLOWLY MONDAY BUT
CONFIDENCE IS LOW IN THEM REACHING 10 FT...SO HAVE NOT ISSUED
ANYTHING FOR SEAS AT THIS TIME.
MODELS HAVE COME INTO DECENT AGREEMENT ABOUT A LOW PRESSURE SYSTEM
APPROACHING THE CENTRAL OREGON WATERS AND MOVING INLAND MONDAY
NIGHT. HOWEVER IDEAS OF THE STRENGTH OF THE LOW STILL VARY
SIGNIFICANTLY...SO IT`S HARD TO SAY EXACTLY HOW STRONG WINDS WILL
BE. SMALL CRAFT WINDS SEEM LIKELY OVER THE CENTRAL OREGON WATERS
BUT GALES CANNOT BE RULED OUT AT THIS POINT. SEAS LOOK LIKE THEY
WILL BUILD TO AROUND 10 FT WITH THIS SYSTEM AND WILL BE
PARTICULARLY CHOPPY IN AREAS WITH HIGHER WINDS.
CONDITIONS SHOULD IMPROVE DURING THE DAY TUESDAY BEHIND THE LOW
PASSAGE. MODELS SHOW ONE LAST WAVE BRUSHING THE NORTHERN OREGON
WATERS WEDNESDAY WHICH COULD BRING SMALL CRAFT WINDS...BUT
OTHERWISE THE REST OF THE FORECAST PERIOD APPEARS RATHER FAVORABLE
AS HIGH PRESSURE BUILDS OVER THE AFTER MIDWEEK. BOWEN/26
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 5 AM TO 11 PM PDT MONDAY
FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 8 PM
PDT THIS EVENING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 AM TO
10 AM PDT MONDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
242 PM PDT SUN MAR 22 2015
.SYNOPSIS...
High pressure will bring a relatively quiet weather day on
Sunday before another moist and breezy cold front arrives tonight.
Showery weather will be in place through midweek, then a gradual
warming and drying trend returns late in the week.
&&
.DISCUSSION...
Tonight through Monday...An unsettled and potentially wet period
awaits the Inland NW care of a occluded front tonight and an cool
and unstable trough for Monday. The occluded front was currently
over western portions of Washington and Oregon...and was moving
slowly northeastward. We`ve already begun to see mid-level
moisture and warm air advection bring some clouds and sprinkles
over extreme SE WA/NC Idaho as well as near the Cascades. This
area will certainly increase in coverage overnight as the front
begins to head east of the Cascades. The front will pass through
the Cascades during the evening and by midnight should head into
the eastern third of Washington and the Idaho Panhandle.
Precipitation from the front should be widespread...however it
won`t be heavy...and it may not even measure in the lee of the
Cascades. There is an exception though over SE Washington and the
southern Panhandle. Model guidance has been consistent in painting
this area in moderate precipitation. This is likely in response to
the shortwave trough currently buckling the occluded front over SW
Oregon and NW California. The 18z NAM is showing this nicely and
it enhances the lift and moisture content along the front near the
Lewiston area by mid/late evening. This enhanced precipitation
potential will likely continue until drier air moves in behind the
front toward daybreak. QPF totals vary widely between model
guidance suites, however we will follow the GEFS and SREF guidance
and put QPF totals in the 0.25-0.50 inch range. Local amounts will
likely be higher especially over the Clearwater Mountains as
orographic enhancements will likely develop over southwest facing
slopes.
For Monday...drier air will initially work over the
region...however its residence will be brief as another shortwave
trough moves into from the southwest. This one will have less
moisture and upper level forcing to work with however it will have
the benefit of deeper instability. 500 mb temps plummet into the
-28 to -30c range by afternoon as the weakening negative tilted
trough moves in. This results in deepening instability with model
soundings indicating the small potential for thunderstorms. It`s
far from a slam dunk due to limited instability (less than we had
yesterday) plus the cloud base temperatures are around -4 to -6c.
This is still warm enough to have liquid in the cloud bases...but
it may not be plentiful. Thus this could limit the crucial charge
separation needed for lightning. Based on SREF instability progs
and the GFS MUCAPEs...we will place the best chances of thunder
north and east of the upper level trough axis. This is roughly
east of a line from Tonasket to Ritzville. Snow levels will fall
as well with the cooler air and its conceivable that any location
could receive graupel showers. However as for accumulating
snows...we expect that to occur generally between 3500-4000 ft and
above. Amounts will not be heavy unless showers continually move
over the same locations. fx
Monday night through Wednesday...the region will be under the
influence of an upper level trough and associated cold pool aloft
during this forecast period. Instability showers will affect most
of the forecast area with the greatest areal coverage during the
afternoon and evening hours. Additional dynamic support will be
provided by a an elongated vorticity maximum in the base of the
broad trough that will slide over the Inland Northwest Tuesday and
Tuesday night. Most favored areas will be the northern mountains
and the rising terrain east of the basin. Convective parameters
should be adequate to foster a few thunderstorms with the best
chance for thunder being Monday evening over the northeast zones.
By Wednesday, a ridge of high pressure will start building over
the region. Models continue to indicate a decent amount of
moisture riding along the ridge so any residual vorticity, aided
by northwest upslope flow, will be able to wring out a few
showers, mainly over the Idaho panhandle. Winds will be breezy to
windy Monday night then lighten overnight. Temperatures will be a
bit on the cool side Tuesday under the upper trough, then warm a
few degrees for Wednesday as the ridge builds and cloud cover
diminishes. /Kelch
Wednesday night through Sunday: A ridge of high pressure builds
in through the end of the work week, leading to an overall drying
and warming trend. But first some shower chances linger. Wednesday
night and Thursday the region will be in a northwest flow, with
the jet axis migrating east-southeast across the northern Rockies.
A boundary across north Idaho gradually shifts east too. Models
also show a weak mid-level vorticity max dropping south across
Washington into Oregon. Additionally PWATs linger around 0.50 to
0.75 inches. Individually none of these are particularly
impressive. However together they will keep some shower threat
alive. Chances will be best across the Cascades and southeast
Washington through the central Panhandle Wednesday night, then
mainly over the central Panhandle Thursday. Overall precipitation
amounts, if anything accumulates, looks light. Otherwise the
building ridge will lead to drier weather, with a few passing
middle to high clouds. The ridge is dampened toward next weekend
with a Pacific trough pushing east. However models have trended
strong with the ridge and now indicate that trough stretches and
splits. The southern split remains off the CA coast and the
northern split moves across western Canada, mainly brushing our
northern CWA through the weekend. This will return some slight
shower threat to the Cascades and near the Canadian border;
otherwise models indicate a drier forecast. Temperatures are
projected to undergo a general warming trend that still looks to
peak on Friday, with highs at this time projected to be around 10
to 15 degrees above average. /J. Cote`
&&
.AVIATION...
18Z TAFS: VFR conditions expected at all TAF sites through 18Z
Monday although a developing rain situation will potentially lower
cloud heights. Through 00z this afternoon there could be a few
sprinkles, especially over SE WA/NC ID and near the Cascades...but
cigs will remain AOA 070. For tonight...a better chance of -ra
will arrive over all forecast sites. Most of the precip will be
light...however a little better forcing could result in heavier
and more persistent precipitation for LWS and PUW between 02z-11z.
If this really develops...there could be MVFR cigs...especially
for PUW...but didn`t think the risk was large enough to place in
forecast. Precip threat will end from W-E overnight and into early
Monday morning. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 40 50 34 48 33 53 / 60 50 40 40 30 30
Coeur d`Alene 37 49 33 47 31 51 / 80 60 60 50 40 30
Pullman 40 50 36 48 35 53 / 90 70 70 50 40 30
Lewiston 43 53 38 53 37 56 / 90 70 60 40 30 20
Colville 38 55 33 53 31 54 / 90 60 60 50 20 30
Sandpoint 36 48 33 48 32 50 / 70 90 70 60 40 30
Kellogg 37 45 34 44 33 48 / 100 90 80 70 50 30
Moses Lake 38 58 35 56 34 60 / 30 20 10 20 10 20
Wenatchee 40 59 39 58 39 60 / 40 30 10 20 10 20
Omak 38 57 33 55 32 57 / 70 30 20 30 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
242 PM PDT SUN MAR 22 2015
.SYNOPSIS...
High pressure will bring a relatively quiet weather day on
Sunday before another moist and breezy cold front arrives tonight.
Showery weather will be in place through midweek, then a gradual
warming and drying trend returns late in the week.
&&
.DISCUSSION...
Tonight through Monday...An unsettled and potentially wet period
awaits the Inland NW care of a occluded front tonight and an cool
and unstable trough for Monday. The occluded front was currently
over western portions of Washington and Oregon...and was moving
slowly northeastward. We`ve already begun to see mid-level
moisture and warm air advection bring some clouds and sprinkles
over extreme SE WA/NC Idaho as well as near the Cascades. This
area will certainly increase in coverage overnight as the front
begins to head east of the Cascades. The front will pass through
the Cascades during the evening and by midnight should head into
the eastern third of Washington and the Idaho Panhandle.
Precipitation from the front should be widespread...however it
won`t be heavy...and it may not even measure in the lee of the
Cascades. There is an exception though over SE Washington and the
southern Panhandle. Model guidance has been consistent in painting
this area in moderate precipitation. This is likely in response to
the shortwave trough currently buckling the occluded front over SW
Oregon and NW California. The 18z NAM is showing this nicely and
it enhances the lift and moisture content along the front near the
Lewiston area by mid/late evening. This enhanced precipitation
potential will likely continue until drier air moves in behind the
front toward daybreak. QPF totals vary widely between model
guidance suites, however we will follow the GEFS and SREF guidance
and put QPF totals in the 0.25-0.50 inch range. Local amounts will
likely be higher especially over the Clearwater Mountains as
orographic enhancements will likely develop over southwest facing
slopes.
For Monday...drier air will initially work over the
region...however its residence will be brief as another shortwave
trough moves into from the southwest. This one will have less
moisture and upper level forcing to work with however it will have
the benefit of deeper instability. 500 mb temps plummet into the
-28 to -30c range by afternoon as the weakening negative tilted
trough moves in. This results in deepening instability with model
soundings indicating the small potential for thunderstorms. It`s
far from a slam dunk due to limited instability (less than we had
yesterday) plus the cloud base temperatures are around -4 to -6c.
This is still warm enough to have liquid in the cloud bases...but
it may not be plentiful. Thus this could limit the crucial charge
separation needed for lightning. Based on SREF instability progs
and the GFS MUCAPEs...we will place the best chances of thunder
north and east of the upper level trough axis. This is roughly
east of a line from Tonasket to Ritzville. Snow levels will fall
as well with the cooler air and its conceivable that any location
could receive graupel showers. However as for accumulating
snows...we expect that to occur generally between 3500-4000 ft and
above. Amounts will not be heavy unless showers continually move
over the same locations. fx
Monday night through Wednesday...the region will be under the
influence of an upper level trough and associated cold pool aloft
during this forecast period. Instability showers will affect most
of the forecast area with the greatest areal coverage during the
afternoon and evening hours. Additional dynamic support will be
provided by a an elongated vorticity maximum in the base of the
broad trough that will slide over the Inland Northwest Tuesday and
Tuesday night. Most favored areas will be the northern mountains
and the rising terrain east of the basin. Convective parameters
should be adequate to foster a few thunderstorms with the best
chance for thunder being Monday evening over the northeast zones.
By Wednesday, a ridge of high pressure will start building over
the region. Models continue to indicate a decent amount of
moisture riding along the ridge so any residual vorticity, aided
by northwest upslope flow, will be able to wring out a few
showers, mainly over the Idaho panhandle. Winds will be breezy to
windy Monday night then lighten overnight. Temperatures will be a
bit on the cool side Tuesday under the upper trough, then warm a
few degrees for Wednesday as the ridge builds and cloud cover
diminishes. /Kelch
Wednesday night through Sunday: A ridge of high pressure builds
in through the end of the work week, leading to an overall drying
and warming trend. But first some shower chances linger. Wednesday
night and Thursday the region will be in a northwest flow, with
the jet axis migrating east-southeast across the northern Rockies.
A boundary across north Idaho gradually shifts east too. Models
also show a weak mid-level vorticity max dropping south across
Washington into Oregon. Additionally PWATs linger around 0.50 to
0.75 inches. Individually none of these are particularly
impressive. However together they will keep some shower threat
alive. Chances will be best across the Cascades and southeast
Washington through the central Panhandle Wednesday night, then
mainly over the central Panhandle Thursday. Overall precipitation
amounts, if anything accumulates, looks light. Otherwise the
building ridge will lead to drier weather, with a few passing
middle to high clouds. The ridge is dampened toward next weekend
with a Pacific trough pushing east. However models have trended
strong with the ridge and now indicate that trough stretches and
splits. The southern split remains off the CA coast and the
northern split moves across western Canada, mainly brushing our
northern CWA through the weekend. This will return some slight
shower threat to the Cascades and near the Canadian border;
otherwise models indicate a drier forecast. Temperatures are
projected to undergo a general warming trend that still looks to
peak on Friday, with highs at this time projected to be around 10
to 15 degrees above average. /J. Cote`
&&
.AVIATION...
18Z TAFS: VFR conditions expected at all TAF sites through 18Z
Monday although a developing rain situation will potentially lower
cloud heights. Through 00z this afternoon there could be a few
sprinkles, especially over SE WA/NC ID and near the Cascades...but
cigs will remain AOA 070. For tonight...a better chance of -ra
will arrive over all forecast sites. Most of the precip will be
light...however a little better forcing could result in heavier
and more persistent precipitation for LWS and PUW between 02z-11z.
If this really develops...there could be MVFR cigs...especially
for PUW...but didn`t think the risk was large enough to place in
forecast. Precip threat will end from W-E overnight and into early
Monday morning. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 40 50 34 48 33 53 / 60 50 40 40 30 30
Coeur d`Alene 37 49 33 47 31 51 / 80 60 60 50 40 30
Pullman 40 50 36 48 35 53 / 90 70 70 50 40 30
Lewiston 43 53 38 53 37 56 / 90 70 60 40 30 20
Colville 38 55 33 53 31 54 / 90 60 60 50 20 30
Sandpoint 36 48 33 48 32 50 / 70 90 70 60 40 30
Kellogg 37 45 34 44 33 48 / 100 90 80 70 50 30
Moses Lake 38 58 35 56 34 60 / 30 20 10 20 10 20
Wenatchee 40 59 39 58 39 60 / 40 30 10 20 10 20
Omak 38 57 33 55 32 57 / 70 30 20 30 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
242 PM PDT SUN MAR 22 2015
.SYNOPSIS...
High pressure will bring a relatively quiet weather day on
Sunday before another moist and breezy cold front arrives tonight.
Showery weather will be in place through midweek, then a gradual
warming and drying trend returns late in the week.
&&
.DISCUSSION...
Tonight through Monday...An unsettled and potentially wet period
awaits the Inland NW care of a occluded front tonight and an cool
and unstable trough for Monday. The occluded front was currently
over western portions of Washington and Oregon...and was moving
slowly northeastward. We`ve already begun to see mid-level
moisture and warm air advection bring some clouds and sprinkles
over extreme SE WA/NC Idaho as well as near the Cascades. This
area will certainly increase in coverage overnight as the front
begins to head east of the Cascades. The front will pass through
the Cascades during the evening and by midnight should head into
the eastern third of Washington and the Idaho Panhandle.
Precipitation from the front should be widespread...however it
won`t be heavy...and it may not even measure in the lee of the
Cascades. There is an exception though over SE Washington and the
southern Panhandle. Model guidance has been consistent in painting
this area in moderate precipitation. This is likely in response to
the shortwave trough currently buckling the occluded front over SW
Oregon and NW California. The 18z NAM is showing this nicely and
it enhances the lift and moisture content along the front near the
Lewiston area by mid/late evening. This enhanced precipitation
potential will likely continue until drier air moves in behind the
front toward daybreak. QPF totals vary widely between model
guidance suites, however we will follow the GEFS and SREF guidance
and put QPF totals in the 0.25-0.50 inch range. Local amounts will
likely be higher especially over the Clearwater Mountains as
orographic enhancements will likely develop over southwest facing
slopes.
For Monday...drier air will initially work over the
region...however its residence will be brief as another shortwave
trough moves into from the southwest. This one will have less
moisture and upper level forcing to work with however it will have
the benefit of deeper instability. 500 mb temps plummet into the
-28 to -30c range by afternoon as the weakening negative tilted
trough moves in. This results in deepening instability with model
soundings indicating the small potential for thunderstorms. It`s
far from a slam dunk due to limited instability (less than we had
yesterday) plus the cloud base temperatures are around -4 to -6c.
This is still warm enough to have liquid in the cloud bases...but
it may not be plentiful. Thus this could limit the crucial charge
separation needed for lightning. Based on SREF instability progs
and the GFS MUCAPEs...we will place the best chances of thunder
north and east of the upper level trough axis. This is roughly
east of a line from Tonasket to Ritzville. Snow levels will fall
as well with the cooler air and its conceivable that any location
could receive graupel showers. However as for accumulating
snows...we expect that to occur generally between 3500-4000 ft and
above. Amounts will not be heavy unless showers continually move
over the same locations. fx
Monday night through Wednesday...the region will be under the
influence of an upper level trough and associated cold pool aloft
during this forecast period. Instability showers will affect most
of the forecast area with the greatest areal coverage during the
afternoon and evening hours. Additional dynamic support will be
provided by a an elongated vorticity maximum in the base of the
broad trough that will slide over the Inland Northwest Tuesday and
Tuesday night. Most favored areas will be the northern mountains
and the rising terrain east of the basin. Convective parameters
should be adequate to foster a few thunderstorms with the best
chance for thunder being Monday evening over the northeast zones.
By Wednesday, a ridge of high pressure will start building over
the region. Models continue to indicate a decent amount of
moisture riding along the ridge so any residual vorticity, aided
by northwest upslope flow, will be able to wring out a few
showers, mainly over the Idaho panhandle. Winds will be breezy to
windy Monday night then lighten overnight. Temperatures will be a
bit on the cool side Tuesday under the upper trough, then warm a
few degrees for Wednesday as the ridge builds and cloud cover
diminishes. /Kelch
Wednesday night through Sunday: A ridge of high pressure builds
in through the end of the work week, leading to an overall drying
and warming trend. But first some shower chances linger. Wednesday
night and Thursday the region will be in a northwest flow, with
the jet axis migrating east-southeast across the northern Rockies.
A boundary across north Idaho gradually shifts east too. Models
also show a weak mid-level vorticity max dropping south across
Washington into Oregon. Additionally PWATs linger around 0.50 to
0.75 inches. Individually none of these are particularly
impressive. However together they will keep some shower threat
alive. Chances will be best across the Cascades and southeast
Washington through the central Panhandle Wednesday night, then
mainly over the central Panhandle Thursday. Overall precipitation
amounts, if anything accumulates, looks light. Otherwise the
building ridge will lead to drier weather, with a few passing
middle to high clouds. The ridge is dampened toward next weekend
with a Pacific trough pushing east. However models have trended
strong with the ridge and now indicate that trough stretches and
splits. The southern split remains off the CA coast and the
northern split moves across western Canada, mainly brushing our
northern CWA through the weekend. This will return some slight
shower threat to the Cascades and near the Canadian border;
otherwise models indicate a drier forecast. Temperatures are
projected to undergo a general warming trend that still looks to
peak on Friday, with highs at this time projected to be around 10
to 15 degrees above average. /J. Cote`
&&
.AVIATION...
18Z TAFS: VFR conditions expected at all TAF sites through 18Z
Monday although a developing rain situation will potentially lower
cloud heights. Through 00z this afternoon there could be a few
sprinkles, especially over SE WA/NC ID and near the Cascades...but
cigs will remain AOA 070. For tonight...a better chance of -ra
will arrive over all forecast sites. Most of the precip will be
light...however a little better forcing could result in heavier
and more persistent precipitation for LWS and PUW between 02z-11z.
If this really develops...there could be MVFR cigs...especially
for PUW...but didn`t think the risk was large enough to place in
forecast. Precip threat will end from W-E overnight and into early
Monday morning. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 40 50 34 48 33 53 / 60 50 40 40 30 30
Coeur d`Alene 37 49 33 47 31 51 / 80 60 60 50 40 30
Pullman 40 50 36 48 35 53 / 90 70 70 50 40 30
Lewiston 43 53 38 53 37 56 / 90 70 60 40 30 20
Colville 38 55 33 53 31 54 / 90 60 60 50 20 30
Sandpoint 36 48 33 48 32 50 / 70 90 70 60 40 30
Kellogg 37 45 34 44 33 48 / 100 90 80 70 50 30
Moses Lake 38 58 35 56 34 60 / 30 20 10 20 10 20
Wenatchee 40 59 39 58 39 60 / 40 30 10 20 10 20
Omak 38 57 33 55 32 57 / 70 30 20 30 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
242 PM PDT SUN MAR 22 2015
.SYNOPSIS...
High pressure will bring a relatively quiet weather day on
Sunday before another moist and breezy cold front arrives tonight.
Showery weather will be in place through midweek, then a gradual
warming and drying trend returns late in the week.
&&
.DISCUSSION...
Tonight through Monday...An unsettled and potentially wet period
awaits the Inland NW care of a occluded front tonight and an cool
and unstable trough for Monday. The occluded front was currently
over western portions of Washington and Oregon...and was moving
slowly northeastward. We`ve already begun to see mid-level
moisture and warm air advection bring some clouds and sprinkles
over extreme SE WA/NC Idaho as well as near the Cascades. This
area will certainly increase in coverage overnight as the front
begins to head east of the Cascades. The front will pass through
the Cascades during the evening and by midnight should head into
the eastern third of Washington and the Idaho Panhandle.
Precipitation from the front should be widespread...however it
won`t be heavy...and it may not even measure in the lee of the
Cascades. There is an exception though over SE Washington and the
southern Panhandle. Model guidance has been consistent in painting
this area in moderate precipitation. This is likely in response to
the shortwave trough currently buckling the occluded front over SW
Oregon and NW California. The 18z NAM is showing this nicely and
it enhances the lift and moisture content along the front near the
Lewiston area by mid/late evening. This enhanced precipitation
potential will likely continue until drier air moves in behind the
front toward daybreak. QPF totals vary widely between model
guidance suites, however we will follow the GEFS and SREF guidance
and put QPF totals in the 0.25-0.50 inch range. Local amounts will
likely be higher especially over the Clearwater Mountains as
orographic enhancements will likely develop over southwest facing
slopes.
For Monday...drier air will initially work over the
region...however its residence will be brief as another shortwave
trough moves into from the southwest. This one will have less
moisture and upper level forcing to work with however it will have
the benefit of deeper instability. 500 mb temps plummet into the
-28 to -30c range by afternoon as the weakening negative tilted
trough moves in. This results in deepening instability with model
soundings indicating the small potential for thunderstorms. It`s
far from a slam dunk due to limited instability (less than we had
yesterday) plus the cloud base temperatures are around -4 to -6c.
This is still warm enough to have liquid in the cloud bases...but
it may not be plentiful. Thus this could limit the crucial charge
separation needed for lightning. Based on SREF instability progs
and the GFS MUCAPEs...we will place the best chances of thunder
north and east of the upper level trough axis. This is roughly
east of a line from Tonasket to Ritzville. Snow levels will fall
as well with the cooler air and its conceivable that any location
could receive graupel showers. However as for accumulating
snows...we expect that to occur generally between 3500-4000 ft and
above. Amounts will not be heavy unless showers continually move
over the same locations. fx
Monday night through Wednesday...the region will be under the
influence of an upper level trough and associated cold pool aloft
during this forecast period. Instability showers will affect most
of the forecast area with the greatest areal coverage during the
afternoon and evening hours. Additional dynamic support will be
provided by a an elongated vorticity maximum in the base of the
broad trough that will slide over the Inland Northwest Tuesday and
Tuesday night. Most favored areas will be the northern mountains
and the rising terrain east of the basin. Convective parameters
should be adequate to foster a few thunderstorms with the best
chance for thunder being Monday evening over the northeast zones.
By Wednesday, a ridge of high pressure will start building over
the region. Models continue to indicate a decent amount of
moisture riding along the ridge so any residual vorticity, aided
by northwest upslope flow, will be able to wring out a few
showers, mainly over the Idaho panhandle. Winds will be breezy to
windy Monday night then lighten overnight. Temperatures will be a
bit on the cool side Tuesday under the upper trough, then warm a
few degrees for Wednesday as the ridge builds and cloud cover
diminishes. /Kelch
Wednesday night through Sunday: A ridge of high pressure builds
in through the end of the work week, leading to an overall drying
and warming trend. But first some shower chances linger. Wednesday
night and Thursday the region will be in a northwest flow, with
the jet axis migrating east-southeast across the northern Rockies.
A boundary across north Idaho gradually shifts east too. Models
also show a weak mid-level vorticity max dropping south across
Washington into Oregon. Additionally PWATs linger around 0.50 to
0.75 inches. Individually none of these are particularly
impressive. However together they will keep some shower threat
alive. Chances will be best across the Cascades and southeast
Washington through the central Panhandle Wednesday night, then
mainly over the central Panhandle Thursday. Overall precipitation
amounts, if anything accumulates, looks light. Otherwise the
building ridge will lead to drier weather, with a few passing
middle to high clouds. The ridge is dampened toward next weekend
with a Pacific trough pushing east. However models have trended
strong with the ridge and now indicate that trough stretches and
splits. The southern split remains off the CA coast and the
northern split moves across western Canada, mainly brushing our
northern CWA through the weekend. This will return some slight
shower threat to the Cascades and near the Canadian border;
otherwise models indicate a drier forecast. Temperatures are
projected to undergo a general warming trend that still looks to
peak on Friday, with highs at this time projected to be around 10
to 15 degrees above average. /J. Cote`
&&
.AVIATION...
18Z TAFS: VFR conditions expected at all TAF sites through 18Z
Monday although a developing rain situation will potentially lower
cloud heights. Through 00z this afternoon there could be a few
sprinkles, especially over SE WA/NC ID and near the Cascades...but
cigs will remain AOA 070. For tonight...a better chance of -ra
will arrive over all forecast sites. Most of the precip will be
light...however a little better forcing could result in heavier
and more persistent precipitation for LWS and PUW between 02z-11z.
If this really develops...there could be MVFR cigs...especially
for PUW...but didn`t think the risk was large enough to place in
forecast. Precip threat will end from W-E overnight and into early
Monday morning. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 40 50 34 48 33 53 / 60 50 40 40 30 30
Coeur d`Alene 37 49 33 47 31 51 / 80 60 60 50 40 30
Pullman 40 50 36 48 35 53 / 90 70 70 50 40 30
Lewiston 43 53 38 53 37 56 / 90 70 60 40 30 20
Colville 38 55 33 53 31 54 / 90 60 60 50 20 30
Sandpoint 36 48 33 48 32 50 / 70 90 70 60 40 30
Kellogg 37 45 34 44 33 48 / 100 90 80 70 50 30
Moses Lake 38 58 35 56 34 60 / 30 20 10 20 10 20
Wenatchee 40 59 39 58 39 60 / 40 30 10 20 10 20
Omak 38 57 33 55 32 57 / 70 30 20 30 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
1203 PM PDT SUN MAR 22 2015
.SYNOPSIS...
High pressure will bring a relatively quiet weather day on
Sunday before another moist and breezy cold front arrives tonight.
Showery weather will be in place through midweek then a gradual
warming and drying trend returns late in the week.
&&
.DISCUSSION...
Rest of today...Satellite this morning was showing considerable
cloudiness moving into the region from the southwest. Much of this
cloudiness was associated with a pool of moisture and mid-level
warm air advection. Models having a tough time figuring out
whether this will result in precipitation or not...however the
radar doesn`t lie and its showing a northeast- southwest swath of
precipitation stretching from the Waterville Plateau to Hood
River. Thus far precipitation reports have been few and far
between, however in the past hour Ephrata did pick up some rain
and the radar echoes continue to maintain their strength as they
move to the northeast. There were also some lighter radar echoes
around Lewiston and the Camas Prairie heading to the east-
northeast. These latter echoes are less of a concern through early
afternoon...however still would not rule out some light sprinkles
there. Better chances will arrive by late afternoon at the
earliest, but more likely during the evening. For the activity
over the Waterville Plateau...the only model which is showing any
precipitation is the HRRR...and based or radar trends...we will
follow its lead. This solution shows this activity continuing to
feed to the NE through the afternoon...with light precipitation
becoming possible across most locations of NC and NE Washington.
Earlier the HRRR was also showing the light precipitation
spreading into N Idaho, but lately it has backed off on that idea.
Due to the variability...we will play it safe and throw light
showers or sprinkles across that area as well. The other forecast
change for today will revolve around temperatures. Clouds are
appreciably more opaque and extensive than expected and this is
having an impact on daytime heating. Consequently we will lower
afternoon high temperatures, especially for locations over the
Basin, Wenatchee area, and Okanogan Valley. fx
&&
.AVIATION...
18Z TAFS: VFR conditions expected at all TAF sites through 18Z
Monday although a developing rain situation will potentially lower
cloud heights. Through 00z this afternoon there could be a few
sprinkles, especially over SE WA/NC ID and near the Cascades...but
cigs will remain AOA 070. For tonight...a better chance of -ra
will arrive over all forecast sites. Most of the precip will be
light...however a little better forcing could result in heavier
and more persistent precipitation for LWS and PUW between 02z-11z.
If this really develops...there could be MVFR cigs...especially
for PUW...but didn`t think the risk was large enough to place in
forecast. Precip threat will end from W-E overnight and into early
Monday morning. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 57 41 52 34 49 35 / 10 100 60 40 40 30
Coeur d`Alene 58 40 52 33 48 32 / 10 100 70 60 50 40
Pullman 58 40 50 36 49 36 / 20 100 80 70 50 40
Lewiston 60 44 54 37 54 38 / 20 90 70 60 40 30
Colville 56 42 56 33 51 32 / 10 100 80 60 50 20
Sandpoint 57 37 50 33 47 32 / 10 100 100 70 60 40
Kellogg 56 37 47 34 44 33 / 20 100 90 80 70 50
Moses Lake 59 40 59 34 58 36 / 20 40 20 10 20 10
Wenatchee 56 36 59 39 58 40 / 20 50 20 10 20 10
Omak 57 39 59 33 56 33 / 10 50 40 20 30 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1033 PM CDT MON MAR 23 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 938 PM CDT MON MAR 23 2015
CHALLENGING SITUATION WITH RESPECT TO THE TUESDAY NIGHT INTO
WEDNESDAY MORNING LATE WINTER SYSTEM TO IMPACT THE REGION. BLEND
OF MODEL RUNS MONDAY WERE INCONSISTENT FOR ANY CONFIDENCE OF A
WATCH ISSUANCE AT THAT TIME. GLANCE AT THIS EVENINGS NAM RUN SHOWS
AN 850 LOW TRACKING OVER EAST CENTRAL WISCONSIN WITH THE SWATCH OF
AN ADVISORY SNOW FROM CENTRAL TO NORTHEAST WISCONSIN. NAM PRODUCES
BETWEEN 0.30 TO 0.50 WATER EQUIVALENT FOR THE FOX VALLEY AND
LAKESHORE BUT WOULD ANTICIPATE THIS WOULD BE A MIX OF
RAIN/SNOW/SLEET AND EVEN SOME FREEZING RAIN DEPENDING ON LOCAL
GROUND TEMPS. JUST NOT ENOUGH TO THROW OUT THE WATCH BUT CERTAINLY
NEED TO KEEP AN EYE ON THE CONVECTIVE POTENTIAL. CONVECTION/LIGHTNING
NOTED OVER THE ROCKIES THIS MONDAY EVENING...PROGS SUGGEST SOME MID
LEVEL LAPSE RATES WORKING INTO STATE IN THE DRY SLOT REGION
TRAILING THE POSSIBLE NEGATIVE TILTED MID LEVEL TROUGH SYSTEM
TOWARD WEDNESDAY MORNING. WILL CONTINUE WITH THE SPS ISSUANCE AND
LET THE MID CREW GET A LOOK AT THE NEXT FULL SET OF DATA.
&&
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 228 PM CDT MON MAR 23 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ONE
SHORTWAVE EXITING THE REGION OVER SOUTHERN LAKE MICHIGAN...WHILE
ANOTHER SHORTWAVE IS MOVING SOUTHEAST OVER NORTHERN MINNESOTA. MID
AND HIGH CLOUDS ARE PULLING OUT OVER NORTHERN LAKE MICHIGAN
ASSOCIATED WITH THE FIRST SHORTWAVE...BUT ANOTHER ROUND OF CLOUDS
IS INCOMING FROM THE LATTER SHORTWAVE...ALONG WITH LIGHT SNOW OVER
NORTHERN MINNESOTA. PLENTY OF DRY AIR PRESENT ACCORDING TO THE 12Z
SOUNDING BELOW 700MB WHICH THE UPSTREAM LIGHT SNOWFALL WILL HAVE TO
OVERCOME IF IT SURVIVES THE TRIP INTO N-C WISCONSIN LATER TODAY.
PLENTY OF LOW CLOUDS ARE LINGERING OVER CENTRAL WISCONSIN ALONG A
LOW LEVEL THERMAL GRADIENT...BUT THE DRY AIR IS HALTING ANY ADVANCE
TO THE NORTHEAST. CONCERNS THROUGH TOMORROW AFTERNOON ARE RELATIVELY
MINOR...AND CENTER AROUND CLOUDS AND TEMPS.
TONIGHT...A COMPACT SHORTWAVE WILL MOVE ACROSS NORTHEAST WISCONSIN
THIS EVENING. EVEN THOUGH THERE IS LIGHT SNOW AHEAD OF IT
CURRENTLY...IT WILL RUN INTO MUCH DRIER AIR BELOW 10KFT AS IT MOVES
INTO NORTHERN WISCONSIN. PROGGED SOUNDINGS SHOW THIS DRY AIR WEDGE
WELL TONIGHT...SO THINK WE WILL ONLY SEE SCATTERED TO BROKEN
MID-CLOUDS THROUGH THE EVENING...THEN CLEARING SKIES OVERNIGHT.
TEMPS FALLING INTO THE TEENS IN THE NORTH AND LOW TO MID 20S SOUTH.
TUESDAY...DRY CANADIAN HIGH PRESSURE HANGS ON FOR ONE MORE DAY.
WILL SEE INCREASING CIRRUS DURING THE AFTERNOON AHEAD OF A STORM
SYSTEM MOVING OVER THE CENTRAL PLAINS...BUT SHOULD SEE A GOOD DEAL
OF SUNSHINE. 925MB TEMPS CONTINUE TO BE CHILLY WITHIN THIS AIRMASS
SO DROPPED MAX TEMPS A DEGREE. HIGHS MAINLY IN THE LOW TO MID 40
EXCEPT COOLER NEAR THE LAKE.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 228 PM CDT MON MAR 23 2015
SYSTEM FOR TUESDAY NIGHT INTO WEDNESDAY MORNING STILL PROBLEMATIC
WITH RESPECT TO EXACT TRACK OF THE SYSTEM...AMOUNT OF WARM AIR AT
THE SURFACE AND ALOFT...AND AMOUNT OF EVAPORATIVE COOLING THAT
WILL TAKE PLACE THAT MAY WIPE OUT THE WARM LAYER.
CONTEMPLATED A WINTER STORM WATCH DUE TO THE IMPACTS THIS SYSTEM
WOULD HAVE ON THE ROADS AND FOR THE MORNING RUSH HOUR. PER
COORDINATION WITH SURROUNDING OFFICES...DECIDED TO GO WITH A
SPECIAL WEATHER STATEMENT TO HIGHLIGHT THE IMPACTS OF THIS SYSTEM.
WITH SYSTEM TRENDING FURTHER SOUTH...THIS WILL HAVE IMPACTS ON
PRECIPITATION TYPES AND SNOW AMOUNTS ACROSS THE FORECAST AREA.
ADDED MORE SNOW TO THE FORECAST DUE TO THE COLDER TEMPERATURES
AT THE SURFACE AND ALOFT THAN PREVIOUS SHIFT. TO SHOW YOU THE
COMPLEXITY OF THE FORECAST...GRB NAM BUFKIT SOUNDING INDICATED
0.4 INCHES OF ICE WHILE THE GFS SUPPORTED 3 TO 5 INCHES OF SNOW.
TRENDED TOWARD THE GFS SOLUTION SINCE CANADIAN/ECMWF MODEL
SUPPORTED THE COLDER GFS SOLUTION. ALSO...THE SPEED OF THE SYSTEM
WAS OF CONCERN. HEAVIEST PRECIPITATION WOULD FALL IN ABOUT A 6 HOUR
PERIOD. THOSE TYPE OF EVENTS USUALLY DO NOT GET US TO WARNING CRITERIA.
SYSTEM WILL EXIT THE REGION WEDNESDAY MORNING WITH COLD CYCLONIC
FLOW NOTED INTO THE FIRST PART OF THE WEEKEND. CHANCE OF RAIN OR
SNOW WILL LINGER INTO THURSDAY BEFORE DRIER AIR ARRIVES. THE NEXT
CHANCE FOR RAIN OR SNOW WOULD BE SATURDAY NIGHT AND SUNDAY.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1032 PM CDT MON MAR 23 2015
SURFACE HIGH PRESSURE SYSTEM ANCHORED OVER THE GREAT LAKES REGION
WILL PROVIDE VFR CONDITIONS REST OF TONIGHT INTO TUESDAY.
DETERIORATING CONDITIONS ANTICIPATED TUESDAY NIGHT AS A STRONG
FRONTAL SYSTEM LIFTS TOWARD WISCONSIN. THE LOWERING CIGS AND VSBYS
WILL INCLUDE A WINTRY MIX OF SNOW SLEET AND FREEZING RAIN AND RAIN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........TDH
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......TDH
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
938 PM CDT MON MAR 23 2015
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 938 PM CDT MON MAR 23 2015
CHALLENGING SITUATION WITH RESPECT TO THE TUESDAY NIGHT INTO
WEDNESDAY MORNING LATE WINTER SYSTEM TO IMPACT THE REGION. BLEND
OF MODEL RUNS MONDAY WERE INCONSISTENT FOR ANY CONFIDENCE OF A
WATCH ISSUANCE AT THAT TIME. GLANCE AT THIS EVENINGS NAM RUN SHOWS
AN 850 LOW TRACKING OVER EAST CENTRAL WISCONSIN WITH THE SWATCH OF
AN ADVISORY SNOW FROM CENTRAL TO NORTHEAST WISCONSIN. NAM PRODUCES
BETWEEN 0.30 TO 0.50 WATER EQUIVALENT FOR THE FOX VALLEY AND
LAKESHORE BUT WOULD ANTICIPATE THIS WOULD BE A MIX OF
RAIN/SNOW/SLEET AND EVEN SOME FREEZING RAIN DEPENDING ON LOCAL
GROUND TEMPS. JUST NOT ENOUGH TO THROW OUT THE WATCH BUT CERTAINLY
NEED TO KEEP AN EYE ON THE CONVECTIVE POTENTIAL. CONVECTION/LIGHTNING
NOTED OVER THE ROCKIES THIS MONDAY EVENING...PROGS SUGGEST SOME MID
LEVEL LAPSE RATES WORKING INTO STATE IN THE DRY SLOT REGION
TRAILING THE POSSIBLE NEGATIVE TILTED MID LEVEL TROUGH SYSTEM
TOWARD WEDNESDAY MORNING. WILL CONTINUE WITH THE SPS ISSUANCE AND
LET THE MID CREW GET A LOOK AT THE NEXT FULL SET OF DATA.
&&
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 228 PM CDT MON MAR 23 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ONE
SHORTWAVE EXITING THE REGION OVER SOUTHERN LAKE MICHIGAN...WHILE
ANOTHER SHORTWAVE IS MOVING SOUTHEAST OVER NORTHERN MINNESOTA. MID
AND HIGH CLOUDS ARE PULLING OUT OVER NORTHERN LAKE MICHIGAN
ASSOCIATED WITH THE FIRST SHORTWAVE...BUT ANOTHER ROUND OF CLOUDS
IS INCOMING FROM THE LATTER SHORTWAVE...ALONG WITH LIGHT SNOW OVER
NORTHERN MINNESOTA. PLENTY OF DRY AIR PRESENT ACCORDING TO THE 12Z
SOUNDING BELOW 700MB WHICH THE UPSTREAM LIGHT SNOWFALL WILL HAVE TO
OVERCOME IF IT SURVIVES THE TRIP INTO N-C WISCONSIN LATER TODAY.
PLENTY OF LOW CLOUDS ARE LINGERING OVER CENTRAL WISCONSIN ALONG A
LOW LEVEL THERMAL GRADIENT...BUT THE DRY AIR IS HALTING ANY ADVANCE
TO THE NORTHEAST. CONCERNS THROUGH TOMORROW AFTERNOON ARE RELATIVELY
MINOR...AND CENTER AROUND CLOUDS AND TEMPS.
TONIGHT...A COMPACT SHORTWAVE WILL MOVE ACROSS NORTHEAST WISCONSIN
THIS EVENING. EVEN THOUGH THERE IS LIGHT SNOW AHEAD OF IT
CURRENTLY...IT WILL RUN INTO MUCH DRIER AIR BELOW 10KFT AS IT MOVES
INTO NORTHERN WISCONSIN. PROGGED SOUNDINGS SHOW THIS DRY AIR WEDGE
WELL TONIGHT...SO THINK WE WILL ONLY SEE SCATTERED TO BROKEN
MID-CLOUDS THROUGH THE EVENING...THEN CLEARING SKIES OVERNIGHT.
TEMPS FALLING INTO THE TEENS IN THE NORTH AND LOW TO MID 20S SOUTH.
TUESDAY...DRY CANADIAN HIGH PRESSURE HANGS ON FOR ONE MORE DAY.
WILL SEE INCREASING CIRRUS DURING THE AFTERNOON AHEAD OF A STORM
SYSTEM MOVING OVER THE CENTRAL PLAINS...BUT SHOULD SEE A GOOD DEAL
OF SUNSHINE. 925MB TEMPS CONTINUE TO BE CHILLY WITHIN THIS AIRMASS
SO DROPPED MAX TEMPS A DEGREE. HIGHS MAINLY IN THE LOW TO MID 40
EXCEPT COOLER NEAR THE LAKE.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 228 PM CDT MON MAR 23 2015
SYSTEM FOR TUESDAY NIGHT INTO WEDNESDAY MORNING STILL PROBLEMATIC
WITH RESPECT TO EXACT TRACK OF THE SYSTEM...AMOUNT OF WARM AIR AT
THE SURFACE AND ALOFT...AND AMOUNT OF EVAPORATIVE COOLING THAT
WILL TAKE PLACE THAT MAY WIPE OUT THE WARM LAYER.
CONTEMPLATED A WINTER STORM WATCH DUE TO THE IMPACTS THIS SYSTEM
WOULD HAVE ON THE ROADS AND FOR THE MORNING RUSH HOUR. PER
COORDINATION WITH SURROUNDING OFFICES...DECIDED TO GO WITH A
SPECIAL WEATHER STATEMENT TO HIGHLIGHT THE IMPACTS OF THIS SYSTEM.
WITH SYSTEM TRENDING FURTHER SOUTH...THIS WILL HAVE IMPACTS ON
PRECIPITATION TYPES AND SNOW AMOUNTS ACROSS THE FORECAST AREA.
ADDED MORE SNOW TO THE FORECAST DUE TO THE COLDER TEMPERATURES
AT THE SURFACE AND ALOFT THAN PREVIOUS SHIFT. TO SHOW YOU THE
COMPLEXITY OF THE FORECAST...GRB NAM BUFKIT SOUNDING INDICATED
0.4 INCHES OF ICE WHILE THE GFS SUPPORTED 3 TO 5 INCHES OF SNOW.
TRENDED TOWARD THE GFS SOLUTION SINCE CANADIAN/ECMWF MODEL
SUPPORTED THE COLDER GFS SOLUTION. ALSO...THE SPEED OF THE SYSTEM
WAS OF CONCERN. HEAVIEST PRECIPITATION WOULD FALL IN ABOUT A 6 HOUR
PERIOD. THOSE TYPE OF EVENTS USUALLY DO NOT GET US TO WARNING CRITERIA.
SYSTEM WILL EXIT THE REGION WEDNESDAY MORNING WITH COLD CYCLONIC
FLOW NOTED INTO THE FIRST PART OF THE WEEKEND. CHANCE OF RAIN OR
SNOW WILL LINGER INTO THURSDAY BEFORE DRIER AIR ARRIVES. THE NEXT
CHANCE FOR RAIN OR SNOW WOULD BE SATURDAY NIGHT AND SUNDAY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 515 PM CDT MON MAR 23 2015
SURFACE HIGH PRESSURE SYSTEM ANCHORED OVER THE GREAT LAKES REGION
WILL PROVIDE VFR CONDITIONS TONIGHT INTO TUESDAY. DETERIORATING
CONDITIONS ANTICIPATED TUESDAY NIGHT AS A STRONG FRONTAL SYSTEM
LIFTS TOWARD WISCONSIN. THE LOWERING CIGS AND VSBYS WILL INCLUDE A
WINTRY MIX OF SNOW SLEET AND FREEZING RAIN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........TDH
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
546 PM CDT SUN MAR 22 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 244 PM CDT SUN MAR 22 2015
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LIGHT TO
MODERATE SNOW OCCURRING OVER SOUTHEAST MINNESOTA...SOUTHWEST
WISCONSIN...AND NORTHEAST IOWA EARLY THIS AFTERNOON ALONG THE
SOUTHWEST FLANK OF A POLAR AIRMASS. ANOTHER AREA OF SNOW EXISTS
OVER THE EASTERN DAKOTAS AHEAD OF A COMPACT SHORTWAVE TROUGH. DRY
AIR EMANATING FROM A CANADIAN HIGH CENTERED OVER THE GREAT LAKES HAS
PREVENTED THE SNOW FROM REACHING THE GROUND OVER CENTRAL WISCONSIN
DESPITE SOME RETURNS ON RADAR EARLIER. AS THE SHORTWAVE OVER THE
DAKOTAS MOVES EAST...SNOW AND ACCUMULATION CHANCES ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...800-700MB THERMAL GRADIENT WILL CONTINUE TO BE ACTIVE
EARLY THIS EVENING OVER SOUTHWEST WISCONSIN. BUT THE MAIN PUSH OF
SNOW WILL BE EXITING MINNESOTA BY MID TO LATE EVENING AHEAD OF A
SHORTWAVE TROUGH...IN CONJUNCTION WITH MID-LEVEL FGEN ON THE NOSE OF
A 25KT LLJ AND A COUPLED JET STRUCTURE. CENTRAL WISCONSIN WILL BE
ON THE NORTHERN FRINGE OF THE AREA OF SNOW WHERE LOW LEVEL EASTERLY
WINDS WILL BE FEEDING IN DRY AIR. SOUNDINGS BECOME SATURATED ABOVE
750MB BY 06Z ACCORDING TO THE NAM...WHILE THE MESOMODELS AND SREF
ARE SLIGHTLY MORE AGGRESSIVE BRINGING IN PRECIP BY THIS TIME INTO
WOOD COUNTY. AS A RESULT...WILL INCREASE PRECIP CHANCES IN THAT
CENTRAL WISCONSIN AREA IN THE 06-09Z PERIOD. ACCUMULATIONS COULD
REACH UP TO AN INCH IN WOOD COUNTY BUT ONLY A TENTH OR TWO FROM
WAUSAU TO OSHKOSH. THE REST OF THE AREA SHOULD SEE INCREASING
CLOUDS. LOWS RANGING FROM THE UPPER TEENS NORTHEAST TO THE MIDDLE
20S SOUTH.
MONDAY...ANY PRECIP WILL HAVE EXITED CENTRAL WISCONSIN BY THE START
OF THE MORNING BUT CLOUDS WILL TAKE MUCH LONGER TO THIN AS CENTRAL
WISCONSIN WILL BE ON THE NORTHEAST EDGE OF THE BAROCLINIC ZONE.
NORTHEAST WISCONSIN WILL HAVE A MUCH GREATER CHANCE OF CLEARING
DURING THE AFTERNOON. THE COMBINATION OF CLOUDS AND AN EAST WIND
WILL KEEP MAX TEMPS COOL. HIGHS WILL BE RANGING THROUGH THE 30S.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 244 PM CDT SUN MAR 22 2015
MAIN CONCERN FOR THIS PACKAGE WILL BE THE SYSTEM TUESDAY NIGHT
AND WEDNESDAY...THEN BELOW NORMAL TEMPERATURES FOR THE END OF
THE WORK WEEK INTO NEXT WEEKEND.
12Z MODELS CONTINUE TO SHOW SIGNIFICANT SYSTEM MOVING ACROSS THE
REGION TUESDAY NIGHT INTO WEDNESDAY. MANY ISSUES TO CONTEND WITH
PRECIPITATION TYPE DUE TO DRY AND COLD EASTERLY FLOW WITH LOW
DEW POINTS TUESDAY AFTERNOON...THEN WARM LAYER ALOFT TUESDAY NIGHT
INTO WEDNESDAY. ONE THING IS FOR SURE...PLENTY OF DRY AIR IN THE
LOW LEVELS TO OVERCOME AS NUMERICAL GUIDANCE INDICATING DEW POINTS
IN THE TEENS TO LOWER 20S. ALOFT...MODELS DIFFER ON HOW FAR NORTH
WARM LAYER WILL GET ON INCREASING SOUTHEAST TO SOUTH WINDS. ALSO...
ANOTHER FACTOR THAT MAY IMPACT PRECIPITATION TYPES WILL BE THE
STEEP MID LEVEL LAPSE RATES (700-500MB) AROUND 6.5 C/KM. EVEN THE
WARM LOCATIONS ACROSS EAST CENTRAL WISCONSIN COULD SEE A MIX OR
START AS SNOW UNTIL WARMER AND MORE MOIST AIR ARRIVES. THESE
ISSUES WILL HAVE AN IMPACT ON SNOW TOTALS...BUT FEEL CONFIDENT THAT
AN ACCUMULATING SNOW WILL OCCUR ACROSS THE NORTH.
PRECIPITATION WILL LINGER INTO WEDNESDAY AS SYSTEM DEPARTS THE REGION.
AN UPPER TROUGH MOVING ACROSS THE REGION WILL BRING A CHANCE OF
RAIN OR SNOW WEDNESDAY NIGHT AND THURSDAY. MAINLY DRY CONDITIONS ARE
EXPECTED INTO SATURDAY THE NEXT CHANCE OF RAIN AND SNOW IS EXPECTED
SATURDAY NIGHT AND SUNDAY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 511 PM CDT SUN MAR 22 2015
AN UPPER DISTURBANCE WILL TRACK SOUTHWEST OF THE AREA TONIGHT.
A NARROW NORTHWEST TO SOUTHEAST BAND OF SNOW WILL EXTEND FROM
CENTRAL MINNESOTA TO FAR SOUTHWEST WISCONSIN TO NORTHERN ILLINOIS.
SOME MVFR CIGS WITH LIGHT SNOW MAY WORK INTO PARTS OF CENTRAL
WISCONSIN OR SOUTH OF LINE FROM MFI TO Y50 FOR AT TIME
TONIGHT...OTHERWISE VFR CONDITIONS EXPECTED TONIGHT INTO MONDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......TDH
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 244 PM CDT SUN MAR 22 2015
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LIGHT TO
MODERATE SNOW OCCURRING OVER SOUTHEAST MINNESOTA...SOUTHWEST
WISCONSIN...AND NORTHEAST IOWA EARLY THIS AFTERNOON ALONG THE
SOUTHWEST FLANK OF A POLAR AIRMASS. ANOTHER AREA OF SNOW EXISTS
OVER THE EASTERN DAKOTAS AHEAD OF A COMPACT SHORTWAVE TROUGH. DRY
AIR EMANATING FROM A CANADIAN HIGH CENTERED OVER THE GREAT LAKES HAS
PREVENTED THE SNOW FROM REACHING THE GROUND OVER CENTRAL WISCONSIN
DESPITE SOME RETURNS ON RADAR EARLIER. AS THE SHORTWAVE OVER THE
DAKOTAS MOVES EAST...SNOW AND ACCUMULATION CHANCES ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...800-700MB THERMAL GRADIENT WILL CONTINUE TO BE ACTIVE
EARLY THIS EVENING OVER SOUTHWEST WISCONSIN. BUT THE MAIN PUSH OF
SNOW WILL BE EXITING MINNESOTA BY MID TO LATE EVENING AHEAD OF A
SHORTWAVE TROUGH...IN CONJUNCTION WITH MID-LEVEL FGEN ON THE NOSE OF
A 25KT LLJ AND A COUPLED JET STRUCTURE. CENTRAL WISCONSIN WILL BE
ON THE NORTHERN FRINGE OF THE AREA OF SNOW WHERE LOW LEVEL EASTERLY
WINDS WILL BE FEEDING IN DRY AIR. SOUNDINGS BECOME SATURATED ABOVE
750MB BY 06Z ACCORDING TO THE NAM...WHILE THE MESOMODELS AND SREF
ARE SLIGHTLY MORE AGGRESSIVE BRINGING IN PRECIP BY THIS TIME INTO
WOOD COUNTY. AS A RESULT...WILL INCREASE PRECIP CHANCES IN THAT
CENTRAL WISCONSIN AREA IN THE 06-09Z PERIOD. ACCUMULATIONS COULD
REACH UP TO AN INCH IN WOOD COUNTY BUT ONLY A TENTH OR TWO FROM
WAUSAU TO OSHKOSH. THE REST OF THE AREA SHOULD SEE INCREASING
CLOUDS. LOWS RANGING FROM THE UPPER TEENS NORTHEAST TO THE MIDDLE
20S SOUTH.
MONDAY...ANY PRECIP WILL HAVE EXITED CENTRAL WISCONSIN BY THE START
OF THE MORNING BUT CLOUDS WILL TAKE MUCH LONGER TO THIN AS CENTRAL
WISCONSIN WILL BE ON THE NORTHEAST EDGE OF THE BAROCLINIC ZONE.
NORTHEAST WISCONSIN WILL HAVE A MUCH GREATER CHANCE OF CLEARING
DURING THE AFTERNOON. THE COMBINATION OF CLOUDS AND AN EAST WIND
WILL KEEP MAX TEMPS COOL. HIGHS WILL BE RANGING THROUGH THE 30S.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 244 PM CDT SUN MAR 22 2015
MAIN CONCERN FOR THIS PACKAGE WILL BE THE SYSTEM TUESDAY NIGHT
AND WEDNESDAY...THEN BELOW NORMAL TEMPERATURES FOR THE END OF
THE WORK WEEK INTO NEXT WEEKEND.
12Z MODELS CONTINUE TO SHOW SIGNIFICANT SYSTEM MOVING ACROSS THE
REGION TUESDAY NIGHT INTO WEDNESDAY. MANY ISSUES TO CONTEND WITH
PRECIPITATION TYPE DUE TO DRY AND COLD EASTERLY FLOW WITH LOW
DEW POINTS TUESDAY AFTERNOON...THEN WARM LAYER ALOFT TUESDAY NIGHT
INTO WEDNESDAY. ONE THING IS FOR SURE...PLENTY OF DRY AIR IN THE
LOW LEVELS TO OVERCOME AS NUMERICAL GUIDANCE INDICATING DEW POINTS
IN THE TEENS TO LOWER 20S. ALOFT...MODELS DIFFER ON HOW FAR NORTH
WARM LAYER WILL GET ON INCREASING SOUTHEAST TO SOUTH WINDS. ALSO...
ANOTHER FACTOR THAT MAY IMPACT PRECIPITATION TYPES WILL BE THE
STEEP MID LEVEL LAPSE RATES (700-500MB) AROUND 6.5 C/KM. EVEN THE
WARM LOCATIONS ACROSS EAST CENTRAL WISCONSIN COULD SEE A MIX OR
START AS SNOW UNTIL WARMER AND MORE MOIST AIR ARRIVES. THESE
ISSUES WILL HAVE AN IMPACT ON SNOW TOTALS...BUT FEEL CONFIDENT THAT
AN ACCUMULATING SNOW WILL OCCUR ACROSS THE NORTH.
PRECIPITATION WILL LINGER INTO WEDNESDAY AS SYSTEM DEPARTS THE REGION.
AN UPPER TROUGH MOVING ACROSS THE REGION WILL BRING A CHANCE OF
RAIN OR SNOW WEDNESDAY NIGHT AND THURSDAY. MAINLY DRY CONDITIONS ARE
EXPECTED INTO SATURDAY THE NEXT CHANCE OF RAIN AND SNOW IS EXPECTED
SATURDAY NIGHT AND SUNDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1147 AM CDT SUN MAR 22 2015
BROKEN MID AND HIGH CLOUDS WILL WORK ACROSS THE FORECAST AREA
THROUGH THE TAF PERIOD. CLOUDS WILL LOWER LATE THIS EVENING INTO
THE OVERNIGHT HOURS AS A UPPER LEVEL DISTURBANCE PASSES ACROSS THE
REGION. LIGHT SNOW WILL BE POSSIBLE OVER CENTRAL WISCONSIN AND THE
SOUTHERN FOX VALLEY FROM THIS SYSTEM WITH UP TO AN INCH OF
ACCUMULATION POSSIBLE NEAR WISCONSIN RAPIDS AND MARSHFIELD...BUT
LESS THAN A HALF INCH AT WAUSAU AND STEVENS POINT. ANY SNOW WILL BE
EXITING BY AROUND SUNRISE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1149 PM CDT SAT MAR 21 2015
.UPDATE...
ISSUED AT 902 PM CDT SAT MAR 21 2015
THE MAIN FOCUS IS ON THE SNOW FOR TOMORROW IN REGARD TO WHEN IT
WILL START AND WHETHER IT WILL START OUT AS RAIN OR SNOW.
VERY DRY AIR IN PLACE IN THE LOW LEVELS THANKS TO NORTHEASTERLY
FLOW ALONG THE SOUTHERN PERIPHERY OF A RIDGE OF HIGH PRESSURE.
HIGH CLOUDS ARE MOVING IN AND WILL THICKEN THROUGH THE NIGHT. AS
WE APPROACH DAYBREAK TOMORROW MORNING MUCH OF THE MESO-GUIDANCE...SUCH
AS THE RAP/HRRR/HOPWRF...IS SUGGESTING THAT THE PRECIPITATION WILL
BE KNOCKING ON THE DOOR OF SOUTHEAST MINNESOTA. AS THE SYSTEM
MOVES INTO THE REGION TOMORROW AFTERNOON...LIFT WILL BE MAXIMIZED
AND THE PRECIPITATION WILL BECOME MORE WIDESPREAD AND INTENSE.
MANY OF THE RAP FORECAST SOUNDINGS FOR TOMORROW MORNING SHOW THAT
AS THE PROFILE BECOMES SATURATED...THE SURFACE/LOW LEVEL WET BULB
TEMPERATURES SHOULD BE COLD ENOUGH TO PRODUCE ALL SNOW. SHOULD AIR
TEMPERATURES STAY A BIT ON THE WARMER SIDE...IT COULD START AS
RAIN...BUT AM LEANING MORE TOWARD THE IDEA THAT SNOW IS THE MORE
LIKELY PRECIPITATION TYPE. IF THAT IS THE CASE...OUR FORECAST SNOW
AMOUNTS WILL LIKELY NEED TO BE UPPED IN THE MORNING/AFTERNOON
TOMORROW. THE RAP CAN TEND TO GO TOO LOW UNDER THE PRECIPITATION
SHIELD...SO CONFIDENCE WAS NOT HIGH ENOUGH TO PUSH THE FORECAST
THAT WAY...PARTICULARLY SINCE SURFACE TEMPERATURES ARE STILL IN
THE MID TO UPPER 30S THROUGH MUCH OF THE AREA. THE OTHER QUESTION
IS WITH ROAD TEMPERATURES AND HOW WARM THEY WILL BE TOMORROW.
TODAY...UNDER MAINLY FULL SUN...THEY REACHED THE 50S/60S AND
CURRENTLY ARE IN THE 40S. WITH HEAVY ENOUGH OF SNOW RATES IN THE
AFTERNOON/EVENING TOMORROW...EXPECT THAT SNOW WILL BE ABLE TO
ACCUMULATE ON THE ROADS AND CAUSE SOME SLICK CONDITIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 349 PM CDT SAT MAR 21 2015
THE FOCUS FOR THIS PERIOD IS ON THE SYSTEM COMING THROUGH FOR
SUNDAY AND SUNDAY NIGHT.
WATER VAPOR SATELLITE SHOWS A COUPLE OF SHORT WAVE TROUGHS OVER
THE PACIFIC NORTHWEST THIS AFTERNOON. THE FIRST WAS OVER THE
ROCKIES OF NORTHERN IDAHO/NORTHWEST MONTANA WITH THE SECOND OVER
WASHINGTON STATE. THE 21.12Z MODELS ALL HANDLE THESE WAVES
SIMILARLY WITH THE LEAD WAVE OVER IDAHO/MONTANA THE MAIN PLAYER AS
IT COMES ACROSS THE UPPER MIDWEST AND THE GREAT LAKES REGION WHILE
THE SECOND WAVE GOES ACROSS SOUTHERN CANADA. THIS FIRST WAVE DOES
NOT BECOME ALL THAT STRONG BUT ENOUGH TO PRODUCE SOME WEAK PV
ADVECTION IN THE 500-300 MB LAYER SUNDAY AFTERNOON AND EVENING.
THE UPPER LEVEL JET WILL ALSO BE ASSOCIATED WITH THIS WAVE WITH
THE AREA COMING UNDER THE RIGHT ENTRANCE REGION AND ITS ASSOCIATED
VERTICAL MOTIONS. IN THE LOW LEVELS...STILL EXPECTING A STRONG LOW
LEVEL BAROCLINIC ZONE TO BE SET UP FROM NORTHWEST TO SOUTHEAST
ACROSS THE AREA. WEAK TO AT TIMES MODERATE FRONTOGENESIS WILL
OCCUR OVER THE BAROCLINIC ZONE...ESPECIALLY IN THE 750-650 MB
LAYER. THE ISENTROPIC UP GLIDE WILL BE ON THE ORDER OF 2 TO 4
UBAR/S ON THE 285K SURFACE SUNDAY EVENING. EXPECTING THAT ALL THIS
FORCING WILL BE SUFFICIENT TO PRODUCE A BAND OF PRECIPITATION
RIGHT ACROSS THE FORECAST AREA FROM NORTHWEST TO SOUTHEAST. WILL
SHOW AN AREA OF 80 TO 100 PERCENT PRECIPITATION CHANCES STARTING
ACROSS SOUTHEAST MINNESOTA BY LATE MORNING OR EARLY AFTERNOON AND
SPREADING INTO WESTERN WISCONSIN BY LATE AFTERNOON INTO THE
EVENING.
PRECIPITATION TYPES REMAIN A CONCERN THROUGHOUT THE EVENT WITH
THIS SYSTEM. EXPECTING THAT IT SHOULD INITIALLY START OUT AS SOME
LIGHT RAIN. HOWEVER...WHEN THE BEST FORCING OCCURS...THE BUFKIT
SOUNDINGS FROM BOTH THE NAM AND GFS SHOW STRONG LIFT THROUGH THE
DENDRITIC GROWTH ZONE THAT SHOULD BE ABLE TO PRODUCE GOOD SNOW
RATES AND CHANGE THE PRECIPITATION OVER TO ALL SNOW DESPITE THE
BOUNDARY LAYER INITIALLY BEING ABOVE FREEZING. ALSO...THE LOW
LEVEL FLOW WILL BE OUT OF THE EAST AND ALTHOUGH THIS WILL BE
TRYING TO BRING SOME DRIER AIR...THIS DRIER AIR MAY HELP TO PUSH
THE WET BULB ZERO TEMPERATURES DOWN AND AID IN THE TRANSITION TO
ALL SNOW. THERE ALSO IS STILL SOME CONCERN ABOUT A LOSS OF ICE IN
THE CLOUDS AS THE FORCING STARTS TO DIMINISH ON THE BACK SIDE OF
THE PRECIPITATION BAND. WHILE THE MODELS HAVE BEEN CONSISTENT IN
SHOWING THIS...THEY HAVE NOT BEEN CONSISTENT ON THE TIMING OF WHEN
THE ICE COULD BE LOST WITH EACH MODEL RUN SHOWING THE ICE
REMAINING LONGER. WILL STILL SHOW A CHANGE OVER TO FREEZING
RAIN...BUT CONFIDENCE ON THIS CONTINUES TO BE LOW.
WILL ISSUE A WINTER WEATHER ADVISORY FOCUSING ON THE BAND OF
HEAVIER SNOW ACCUMULATIONS...GENERALLY IN THE 2 TO 4 INCH RANGE.
STILL START THIS LATE SUNDAY MORNING ACROSS SOUTHEAST MINNESOTA
INTO FAR WESTERN WISCONSIN AND RUN THIS THROUGH SUNDAY EVENING.
WILL HAVE THE ADVISORY ALONG THE MISSISSIPPI RIVER INTO SOUTHWEST
WISCONSIN FROM ABOUT THE MIDDLE OF SUNDAY AFTERNOON THROUGH SUNDAY
NIGHT. THIS MAY HAVE TO BE EXPANDED LATER TO COVER THE ICING
POTENTIAL...BUT CONFIDENCE ON THIS ASPECT OF THE FORECAST REMAINS
TOO LOW TO ISSUE HEADLINES ON AT THIS TIME.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 349 PM CDT SAT MAR 21 2015
ANOTHER SHORT WAVE COMING IN OVER THE PACIFIC NORTHWEST COAST
WILL CROSS THE NORTHERN ROCKIES AND THEN IS EXPECTED TO DEEPEN
OVER THE UPPER MIDWEST TUESDAY. THE MODELS ARE STILL BOUNCING
AROUND WITH WHETHER THIS SYSTEM WILL COME THROUGH PHASED WITH
ANOTHER NORTHERN STREAM SHORT WAVE TROUGH LIKE THE GFS SHOWS...OR
WHETHER THE TWO SYSTEMS WILL REMAIN SEPARATE LIKE THE ECMWF AND
GEM. EITHER WAY...ALL THE MODELS SHOW ONE AREA OF SURFACE LOW
PRESSURE TRACKING ACROSS OR JUST NORTH OF THE FORECAST AREA WITH
THE ECMWF AND GEM HAVING ANOTHER SURFACE LOW FARTHER NORTH UNDER
THE OTHER SHORT WAVE TROUGH. EITHER OF THESE SOLUTIONS SHOULD
ALLOW ENOUGH WARM AIR TO BE DRAWN IN FOR THIS SYSTEM TO PRIMARILY
PRODUCE RAIN. THE TIMING LOOKS TO HAVE THE PRECIPITATION MOVING IN
TUESDAY AFTERNOON WITH THE BEST CHANCES TUESDAY NIGHT...70 TO 80
PERCENT FOR THE ENTIRE AREA...AND THEN MOVES OUT WEDNESDAY AND
WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1149 PM CDT SAT MAR 21 2015
THE MAIN FOCUS IS ON THE SNOW FOR TOMORROW WITH THE QUESTION BEING
WHEN THE HEAVIEST SNOW BAND WILL MOVE THROUGH. CURRENTLY...IT
APPEARS THAT THE SNOW WILL BEGIN AROUND 16Z AT RST AND 19Z AT LSE
WITH IFR CONDITIONS LIKELY OCCURRING SOON AFTER IT BEGINS. THE
HEAVIEST SNOWFALL LOOKS LIKE IT WILL COME IN THE AFTERNOON AND
EVENING...SO HAVE KEPT THE VISIBILITY DOWN AROUND 3/4SM OVER THAT
TIMEFRAME. THERE COULD BE SOME BRIEF PERIODS WHERE VISIBILITY
DROPS LOWER THAN THAT...BUT CONFIDENCE IS NOT HIGH ENOUGH AT THIS
POINT TO PUT THAT SORT OF DETAIL IN. REGARDLESS...IT LOOKS LIKE AN
EXTENDED PERIOD OF IFR/LIFR CONDITIONS ONCE THE SNOW BEGINS
TOMORROW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 11 AM SUNDAY TO 1 AM CDT MONDAY FOR
WIZ032-033.
WINTER WEATHER ADVISORY FROM 3 PM SUNDAY TO 7 AM CDT MONDAY FOR
WIZ041-053>055-061.
MN...WINTER WEATHER ADVISORY FROM 11 AM SUNDAY TO 1 AM CDT MONDAY FOR
MNZ079-086>088-094-095.
WINTER WEATHER ADVISORY FROM 3 PM SUNDAY TO 7 AM CDT MONDAY FOR
MNZ096.
IA...WINTER WEATHER ADVISORY FROM 3 PM SUNDAY TO 7 AM CDT MONDAY FOR
IAZ010-011.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
523 AM EDT TUE MAR 24 2015
.DISCUSSION...
A PREDOMINANT ZONAL MID/UPR LVL WIND PATTERN ACRS THE REGION WILL
PUSH AN H100-H70 ANTICYCLONE FROM THE DEEP SOUTH INTO THE MID ATLC
TODAY...THEN OFF THE CAROLINA COAST TONIGHT. ONCE IT DOES...IT WILL
BRIDGE A FRONTAL TROF DRAPED OVER THE FL PENINSULA...EVENTUALLY
MERGING WITH THE WRN EXTENSION OF THE ATLC RIDGE OVER THE GREATER
ANTILLES.
THE TRACK OF THE RIDGE WILL GENERATE A SHALLOW NERLY FLOW ACRS
CENTRAL FL THIS MRNG THAT WILL VEER SLOWLY TO THE E BY AFTN...THEN
TO THE SE OVERNIGHT. AT THE SAME TIME...THE ZONAL FLOW ALOFT WILL
PUSH A VERY STABLE SLUG OF H85-H70 AIR FROM THE NRN GOMEX INTO THE
FL PENINSULA...LATEST RUC ANALYSIS SHOWS LAPSE RATES THRU THE LYR
BTWN DROPPING FROM ARND 4.0C/KM OVERHEAD TO AS LOW AS 1.0C/KM S OF
APPALACHICOLA....H70 TEMPS BTWN 8-10C ENVELOP MOST OF THE GOMEX.
THIS WILL EFFECTIVELY CAP VERTICAL MOTION BLO 10KFT WHILE H100-H70
MEAN RH VALUES BLO 60PCT WORK THEIR WAY INTO THE CENTRAL PENINSULA.
ALOFT...RUC SHOWS LITTLE IN THE WAY OF MID LVL VORTICITY OVER THE
GOMEX REGION WHILE A DEPARTING H30-H20 JET STREAK E OF THE BAHAMA
BANK WILL KEEP CENTRAL FL UNDER ITS DESCENDING LEFT REAR QUAD.
WHILE NO SIG COOL AIR ADVECTION HAS OCCURRED BEHIND THE FROPA...AN
EXTENSIVE STRATUS DECK WILL BE SLOW TO BURN OFF AS THE MID LVL
THERMAL CAP PUSHES ACRS THE CENTRAL PENINSULA. A DVLPG ONSHORE FLOW
WILL FURTHER HELP KEEP TEMPS A FEW DEG COOLER THAN WHAT THE GFS MOS
GUIDANCE IS ADVERTISING. WILL GO WITH MAX TEMPS IN THE L/M80S
INTERIOR...M/U70S ALONG THE COAST. LIGHT ONSHORE FLOW OVERNIGHT WILL
KEEP MIN TEMPS IN THE L/M60S...PATCHY FOG IN THE PREDAWN HRS.
WED-THU...DEVELOPING SFC LOW HEADING TOWARD THE GREAT LAKES FROM THE
CENTRAL PLAINS WILL BUMP THE CENTER OF A RATHER LARGE AREA OF HIGH
PRESSURE OFF THE NEW ENGLAND COAST. AS A RESULT THE FLORIDA
PENINSULA WILL BECOME AWASH IN RETURN FLOW AS THE HIGH CENTER
REPOSITIONS SOUTHEAST OVER THE WESTERN ATLANTIC. THIS WILL PROMOTE A
STEADY RETURN OF MOISTURE AS LOCAL WINDS VEER SE-S WED...THEN S-SW
THU. MOISTURE SHOULD BE SUFFICIENT FOR LOCAL CIRCULATIONS AND
BREEZES TO PRODUCE SCT SHOWERS WITH BETTER CHANCES ALONG TREASURE
COAST AND VICINITY OF LAKE OKEECHOBEE WED THEN SPREADING NORTH FOR
THU. WARM WITH MAX TEMPS IN THE MID TO UPPER 80S.
FRI-MON...SIGNIFICANT UPPER TROUGH DIGS SOUTHWARD TO AID THE
PROGRESSION OF THE NEXT SYSTEM TO APPROACH PENINSULA BY FRIDAY.
SOME DYNAMIC VIGOR PRESENT ESPECIALLY WITH STOUT UPPER JET JUST
TO NORTH. CHANCE FOR STORMS NOTED WITH SOME PERHAPS BECOMING STRONG
AS COLD FRONT WITH PREFRONTAL TROUGH SWEEPS BY DURING DAY ON FRI
AND FRI EVENING. POST-FRONTAL COOLER MAX TEMPS BEHIND THE FRONT
FALL BACK IN TO THE 70S AND MINS IN 50S (EXCEPT SOME UPPER 40S
INTERIOR LAKE/VOLUSIA)...MODERATING LATE IN THE PERIOD.
&&
.AVIATION...THRU 25/12Z
SFC WINDS: THRU 24/16Z...N/NW 3-6KTS. BTWN 24/16Z-24/18Z...BCMG E/NE
6-9KTS CONTG THRU 25/03Z. AFT 25/03Z...E/SE AOB 5KTS.
VSBYS/WX: E OF KVRB-KOBE...THRU 24/14Z AREAS IFR/LCL LIFR IN BR/FG.
AFT 24/14Z...VFR ALL SITES CONTG THRU 25/08Z. AFT 25/08Z LCL MVFR BR.
CIGS: E OF KVRB-KOBE THRU 24/14Z PREVAILING VLFR BLO FL004...BTWN
24/14Z-24/16Z MVFR BTWN FL020-030...AFT 24/16Z VFR.
W OF KVRB-KOBE THRU 24/15Z PREVAILING IFR BTWN FL006-009...BTWN
24/15Z-24/18Z MVFR BTWN FL020-030...AFT 24/18Z VFR.
&&
.MARINE...
TODAY-TONIGHT...HI PRES BUILDING ACRS THE DEEP SOUTH WILL
GENERATE A GENTLE TO MODERATE E/NE BREEZE THRU THE DAY...BCMG A
MODERATE SE BREEZE OVERNIGHT AS THE RIDGE BUILDS OFF THE CAROLINA
COAST AND MERGES WITH A SECOND RIDGE AXIS OVER THE GREATER ANTILLES.
SEAS 2-4FT NEARSHORE AND 3-5FT OFFSHORE.
WED-THU...WINDS BECOME SE FOR WED AND CONTINUE TO VEER TO SW BY
THU GENERALLY 10-15 KNOTS AS CENTER OF HIGH PRESSURE RE-POSITIONS.
SEAS 3-4 FEET NEARSHORE AND 4-5 FEET OFFSHORE.
FRI-SAT...COLD FRONT APPROACHES ON FRI BRINGING INCREASING CHANCES
FOR SHOWERS AND STORMS. OFFSHORE WINDS FRI TURN/SURGE NW 15-20
KNOTS FRI NIGHT IN POST-FRONTAL MODE. CONDITIONS REACH CAUTIONARY
LEVELS NEARSHORE AND SCA OFFSHORE INTO SAT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 76 64 83 66 / 10 10 20 30
MCO 82 64 89 67 / 10 10 20 30
MLB 78 67 84 68 / 10 10 20 40
VRB 78 67 84 67 / 10 10 30 40
LEE 80 63 87 66 / 10 10 20 20
SFB 80 64 87 67 / 10 10 20 30
ORL 82 65 87 68 / 10 10 20 30
FPR 79 66 84 67 / 10 10 30 40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...MB
LONG TERM....DS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
350 AM CDT TUE MAR 24 2015
.SHORT TERM...
249 AM CDT
THROUGH TONIGHT...
IR IMAGERY EARLY THIS MORNING INDICATED THE STRATUS LAYER HAS
PUSHED WEST OF THE CHICAGO AREA...HOWEVER A FEW POCKETS OF STRATUS
HAVE BEEN REDEVELOPING AND SLIDING ACROSS FAR NORTHEAST IL. TEMPS
ARE GENERALLY REMAINED IN THE UPR 20S EARLY THIS MORNING...WITH A
FEW LOCATIONS RADIATING INTO THE LOW 20S. A NARROW CHANNEL OF
CIRRUS WAS ALREADY STREAMING NORTHEAST FROM THE DEVELOPING
SHORTWAVE CURRENTLY CENTERED OVER THE CENTRAL PLAINS. THE GRADIENT
WILL REMAIN LIGHT THROUGH DAYBREAK...HOWEVER THE WEAK DIFFLUENT
FLOW WILL QUICKLY DISSIPATE AND MIXING WILL STEADILY INCREASE BY
MID-MORNING. GUIDANCE INDICATES SPEEDS THROUGH THE CHANNEL ARND
20KT.
THE MOIST AXIS DOES APPEAR TO BE SLIGHTLY SLOWER TO ARRIVE ACROSS
NORTHEAST IL UNTIL AFT 21Z...SO HAVE NUDGED TIMING BACK AN HOUR OR
TWO. COULD SEE PRECIP PUSHING INTO THE FAR SOUTHWEST CWFA ARND 18-
20Z...HOWEVER WITH THE WEAK DIFFLUENT FLOW LINGERING FURTHER
NORTH...THIS MAY HELP TO HOLD-OFF PRECIP UNTIL CLOSER TO 00Z. WITH A
STEADY CONVEYOR OF SLIGHTLY WARMER AIR ADVECTING NORTH THIS
AFTN...TEMPS ARE EXPECTED TO WARM TO ARND 40. THE CONCERN IS THAT
WITH THE FRESH SNOWPACK THIS MAY HOLD TEMPS DOWN A DEGREE OR TWO.
TONIGHT...
AS ELUDED TOO ABOVE...PRECIP WILL BE STEADILY INCREASING IN
COVERAGE THIS EVENING. BUT THE MAIN CONCERN FOR TONIGHT WILL
REVOLVE AROUND CONVECTION AND POSSIBLY SOME STRONGER EMBEDDED
THUNDERSTORMS. MID- LVL SHEAR IS IMPRESSIVE THIS EVENING...WITH
VALUES NEARING 40-50KTS. GIVEN THE RATHER MOIST PROFILE AND CLOUDY
ENVIRONMENT...CAPE VALUES WILL REMAIN MINIMAL. 0-3KM BULK SHEAR IS
EQUALLY IMPRESSIVE WITH THIS DYNAMIC NEGATIVELY TILTED SHORTWAVE
TONIGHT. THE SPC HAS THE AREAS SOUTH OF PONTIAC TO FOWLER IN A
MARGINAL RISK FOR SEVERE STORMS TONIGHT.
DEW POINTS WILL BE STEADILY INCREASING THIS EVENING AS WELL...AS
WARM AIR CONTINUES TO ADVECT NORTH. BY LATE THIS EVENING DEW POINTS
WILL BE APPROACHING THE LOW/MID 30S...AND POSSIBLY NEAR 40 ACROSS
THE FAR SOUTH. THEN OVERNIGHT DEW POINTS WILL CONTINUE TO RISE INTO
THE MID/UPR 30S NORTH...AND LOW 40S SOUTH. THIS SHOULD AID IN EATING
INTO THE SNOWPACK RATHER QUICKLY...COUPLED WITH THE RAIN AS WELL.
PWAT VALUES WILL BE NEARING 1 INCH LATE TONIGHT...AS THE MOISTURE
TRANSPORT CONTINUES TO FEED NORTH ACROSS THE FORECAST AREA. CURRENT
TRACK OF THE SHORTWAVE IS TO LIFT NORTHEAST ACROSS PONTIAC TO GARY
BY 9Z...WHICH SHUD HELP PUSH CONVECTIVE COVERAGE EAST/NORTHEAST BY
DAYBREAK WED.
BEACHLER
&&
.LONG TERM...
350 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
THE MAIN STORY DURING THE LONGER TERM PERIOD WILL BE THE AMPLIFYING
UPPER LEVEL FLOW PATTERN ACROSS NORTH AMERICA. UPPER LEVEL RIDGING
IS FORECAST TO BUILD OVER THE WESTERN CONUS IN RESPONSE TO THE
PROGRESSION A SIGNIFICANT DISTURBANCE OVER THE NORTHERN
PACIFIC...AND THIS WILL ULTIMATELY DRIVE SIGNIFICANT HEIGHT FALLS
AND TROUGHING OVER THE THE EASTERN HALF OF THE CONUS. AS A
RESULT...EXPECT TO TRANSITION BACK TO A PERIOD OF MUCH BELOW AVERAGE
TEMPERATURES LATE THIS WEEK INTO THE FIRST HALF OF THE WEEKEND.
THE PERIOD WILL START OUT MILD ON WEDNESDAY FOLLOWING THE PASSAGE OF
THE TUESDAY NIGHT STORM SYSTEM. IT DOES APPEAR THAT CLOUD COVER
COULD LINGER DURING THE DAY ON WEDNESDAY...AND THIS COULD LIMIT THE
AMOUNT OF WARMING WE EXPERIENCE DURING THE DAY. HOWEVER...WITH THE
COLDER AIRMASS NOT ARRIVING ACROSS THE AREA UNTIL LATER WEDNESDAY
NIGHT TEMPERATURES SHOULD BE ABLE TO CLIMB TO...AT LEAST...NEAR 50
DEGREES. AREAS SOUTH OF INTERSTATE 80 STAND THE BEST CHANCES TO
CLIMB WELL INTO THE 50S.
AS A COLD FRONT BEGINS TO SHIFT ACROSS NORTHERN ILLINOIS WEDNESDAY
NIGHT A WEAK SURFACE WAVE OF LOW PRESSURE IS EXPECTED TO DEVELOP
OVER THE SOUTHERN PLAINS...BEFORE QUICKLY SHIFTING NORTHEASTWARD
ALONG THE FRONT INTO THURSDAY MORNING. INCREASING FGEN ALONG THIS
FRONTAL WAVE SHOULD RESULT IN PRECIPITATION DEVELOPMENT WEDNESDAY
NIGHT...PRIMARILY ACROSS MY EAST CENTRAL ILLINOIS AND NORTHWESTERN
INDIANA COUNTIES. THIS ACTIVITY WILL SHIFT TO THE SOUTH AND EAST OF
MY AREA BY EARLY THURSDAY MORNING AS THE COLD FRONT CONTINUES TO
SHIFT SOUTHEASTWARD. DRY BUT COOLER WEATHER IN THE LOW TO 40S IS
EXPECTED FOR THE DAY THURSDAY.
ANOTHER STRONGER PUSH OF COLD AIR WILL ARRIVE OVER THE AREA BY
THURSDAY NIGHT INTO FRIDAY AS YET ANOTHER COLD FRONT SHIFTS OVER THE
AREA. STEEPENING LOW LEVEL LAPSE RATES OVER LAKE MICHIGAN WITH THIS
COLD AIR MASS COULD EVEN RESULT IN SOME LAKE EFFECT SNOW SHOWERS
ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA INTO FRIDAY
MORNING...AND THIS ACTIVITY LOOKS AS THOUGH IT COULD BE COMPLIMENTED
BY ANOTHER UPPER LEVEL PV ANOMALY DIGGING INTO THE BASE OF THE UPPER
LEVEL TROUGH OVER THE AREA. IF THIS SCENARIO PANS OUT AS CURRENTLY
FORECAST...THERE COULD BE SOME MINOR SNOW ACCUMULATIONS ACROSS
PORTIONS OF THE AREA WITH THIS ACTIVITY INTO FRIDAY.
WITH THE HEART OF THE COLD AIR MASS EXPECTED TO BE OVERHEAD ON
FRIDAY...IT LOOKS TO BE THE COLDEST DAY. HIGH TEMPERATURES ARE
CURRENTLY ONLY FORECAST TO GET INTO THE LOWER TO MID 30S...WHICH IS
A GOOD 15 TO 20 DEGREES BELOW AVERAGE. SURFACE HIGH PRESSURE SHOULD
BECOME CENTERED OVER OR NEAR THE AREA BY LATE FRIDAY NIGHT...SO THIS
SHOULD ALLOW TEMPERATURES FRIDAY NIGHT TO DROP INTO THE TEENS
INTO SATURDAY MORNING OUTSIDE OF CHICAGO.
AFTER ANOTHER WELL BELOW AVERAGE DAY ON SATURDAY...THINGS LOOKS TO
WARM BACK UP BY SUNDAY SURFACE RIDGE SHIFTS OVER THE SOUTHEASTERN
CONUS. IT APPEARS THAT SUNDAY COULD END UP NOT ONLY BEING A WARMER
DAY...WITH HIGHS POTENTIALLY WARMING BACK UP NEAR OR JUST ABOVE
AVERAGE...BUT ALSO A VERY BREEZY DAY. FORECAST GUIDANCE SUGGESTS
THAT A POTENT CLIPPER SYSTEM WILL TRACK EAST-SOUTHEASTWARD OVER
SOUTHERN ONTARIO...WHICH COULD SET UP A SURFACE GRADIENT SUPPORTIVE
OF SOME STRONG SOUTHWESTERLY WINDS. IN ADDITION...THE INCREASING WARM
AIR ADVECTON REGIME OVER THE AREA COULD ALSO RESULT IN THE
DEVELOPMENT OF SOME LIGHT RAIN SHOWERS DURING THE DAY.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PATCHY MVFR CIGS THRU 8Z...HOWEVER SHUD BE SOUTHWEST OF ORD/MDW.
* EAST WINDS PERSIST BETWEEN 5-8KT...INCREASING AFT DAYBREAK.
* WINDS TURN SOUTHEAST AND INCREASE MID-MORNING...SPEEDS BETWEEN
12-15KT WITH GUSTS UP TO 20KT.
* RAIN DEVELOPS LATE AFTN/EARLY EVE...WITH STEADIER RAIN AFT 00Z
WED. EMBEDDED THUNDER POSSIBLE AFT 00Z WED. IFR CIGS DEVELOP.
* LLWS POSSIBLE LATE TONIGHT...AOA 2KFT AGL SPEEDS INCREASE TO
50KT FROM SOUTHEAST AFT 2Z WED.
BEACHLER
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE REMAINS CENTERED TO THE NORTHEAST OF THE
REGION...ALLOWING LIGHT EASTERLY FLOW TO PERSIST. DRY AIR HAS BEEN
ABLE TO PUSH STRATUS FURTHER WEST AND SCOUR THE LOW CLOUDS FOR
ORD/MDW/GYY. EXPECT THIS TO SLOWLY PUSH FURTHER WEST OVERNIGHT AND
REACH RFD ARND 8Z. DEVELOPING LOW PRESSURE SYSTEM CONTINUES TO BE
POISED TO ARRIVE ACROSS THE REGION TUESDAY EVENING...WITH RAIN
OVERSPREADING THE TAF SITES LATE IN THE AFTN/EARLY EVE. CURRENT
GUIDANCE INDICATES THAT MVFR CIGS WILL REDEVELOP AFT 22Z AS THE
STEADIER RAIN NEARS THE TAF SITES. THE GRADIENT WILL QUICKLY
INCREASE LATE THIS MORNING...WITH GUSTS NEARING 20KT FROM THE
SOUTHEAST. EXPECT GUSTS TO CONTINUE THRU TONIGHT. LLWS WILL
ACCOMPANY THE LOW PRESSURE SYSTEM...WITH SPEEDS NEARING 50KT AT
2KFT AGL. EXPECT SOME GUSTS OF 20-24KT AT THE SFC.
RAIN WILL PUSH OVER THE TAF SITES...WITH BETTER INSTABILITY
ARRIVING. AT THIS TIME HAVE HELD OFF ON INCLUDING TSRA WITHIN THE
TAF...HOWEVER A FEW EMBEDDED THUNDERSTORMS MAY ACCOMPANY THE
STEADIER RAIN. THUNDER WILL LIKELY REMAIN ISOLATED THRU 09Z...THEN
THE BETTER INSTABILITY DECREASES WITH STEADIER RAIN BEGINNING TO
DISSIPATE SHORTLY BEFORE DAYBREAK WED.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN CIGS THRU 20Z...MEDIUM CONFIDENCE IN TIMING
OF MVFR/IFR CIGS AFT 00Z WED.
* HIGH CONFIDENCE IN RAIN DEVELOPING AFT 22Z...LOW CONFIDENCE IN
PRECISE TIMING. MEDIUM/LOW IN THUNDER TIMING AND COVERAGE
OVERNIGHT INTO EARLY WED MORNING.
* MEDIUM/HIGH CONFIDECE IN LLWS DEVELOPING AND MEDIUM CONFIDENCE
IN SPEEDS OF LLWS.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...SLIGHT CHANCE OF SHOWERS WITH MVFR CIGS EARLY AM.
OTHERWISE PRIMARILY VFR. BREEZY SOUTHWEST WINDS.
THURSDAY...SLIGHT CHANCE OF SHOWERS. MVFR POSSIBLE.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW EARLY. OTHERWISE PRIMARILY
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE OF RAIN. PATCHY MVFR POSSIBLE.
RATZER
&&
.MARINE...
212 PM CDT
HIGH PRESSURE CENTERED OVER EAST-CENTRAL ONTARIO WILL MOVE
SOUTHEAST INTO NEW ENGLAND BY TUESDAY EVENING. THIS WILL ALLOW
EASTERLY WINDS TO SHIFT SOUTHEASTERLY THROUGH THE DAY TUESDAY. LOW
PRESSURE WILL DEVELOP IN THE LEE OF THE ROCKIES THROUGH THE DAY
TUESDAY IN RESPONSE TO AN UPPER LEVEL TROUGH WORKING EASTWARD. ONE
SURFACE LOW WILL CONSOLIDATE ACROSS THE DAKOTAS THEN BE KICKED
EASTWARD BY A SECOND UPPER TROUGH WEDNESDAY. OF MORE IMMEDIATE
NOTE IS THE SURFACE LOW THAT WILL DEVELOP ACROSS THE MID
MISSISSIPPI RIVER VALLEY AND TRACK NORTHEAST FROM THERE LATE
TUESDAY. GUIDANCE HAS STRUGGLED WITH THE STRENGTH AND TRACK OF
THIS LOW WITH MORE OF A SOUTHWARD TRACK FAVORED WHICH TAKES THE
LOW ACROSS SOUTHERN LAKE MICHIGAN. WITH SEVERAL FEATURES IN PLAY
IN TERMS OF THE DEVELOPMENT OF THIS SYSTEM WOULD NOT BE SURPRISED
TO SEE FURTHER FLUCTUATIONS IN THE TRACK/STRENGTH YET TONIGHT AND
TUESDAY MORNING. ALL OF THE ABOVE POINTS TO WINDS THAT ARE NOT AS
STRONG AS THEY APPEARED FOR LAND AND NEARSHORE AREAS...BUT OPEN
WATER AREAS STILL LOOK TO PUSH 30 KT AT TIMES LATE TUESDAY NIGHT
AND WEDNESDAY MORNING...WITH THE STABLE LAYER LIMITING WINDS MUCH
HIGHER THAN THAT SHOULD THE LOW END UP BEING STRONGER. WINDS WILL
BE EASTERLY NORTH OF THE TRACK AND SOUTHERLY SOUTH OF IT WITH A
MORE UNIFORM SOUTHWESTERLY WIND BEHIND THE LOW FOR MUCH OF
WEDNESDAY. THE DAKOTAS LOW WEAKENS AND MOVES ACROSS UPPER MICHIGAN
AND NORTHERN LAKE MICHIGAN WEDNESDAY EVENING WHILE A COLD FRONT
SWEEPS DOWN THE LAKE TURNING WINDS WEST TO NORTHWEST. A STEADY
PRESSURE GRADIENT WILL REMAIN ACROSS THE LAKE THURSDAY AHEAD OF
HIGH PRESSURE WHICH WILL MOVE FROM CENTRAL CANADA TO THE UPPER
MISSISSIPPI RIVER VALLEY BY FRIDAY AND ACROSS THE WESTERN LAKES
FRIDAY NIGHT. BREEZY NORTH TO NORTHWEST WINDS WILL GRADUALLY
DIMINISH DURING THIS TIME. LOW PRESSURE IS THEN EXPECTED TO TRACK
NORTH OF THE AREA EARLY SUNDAY WITH BREEZY SOUTHWEST WINDS
DEVELOPING AHEAD OF IT SHIFTING NORTHWEST AS ANOTHER HIGH MOVES
INTO THE PLAINS MONDAY.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...7 PM TUESDAY TO 4 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
330 AM CDT Tue Mar 24 2015
.SHORT TERM...(Today)
ISSUED AT 329 AM CDT TUE MAR 24 2015
A band of mid-level warm frontogenesis will advance into central IL
from the west this morning, causing rain showers to eventually
develop through the dry low level airmass. The leading edge of the
rain band will likely encounter areas with surface temps at or just
below freezing, but not sure how far south will freezing rain
affect. 08z obs show only Jacksonville and Lawrenceville above
freezing, while the remainder of our C and SE IL obs at or below
freezing. Will need to include a mention of freezing rain a bit
farther south this morning as a result. Road surface temps on IDOT
sites showing road temps ranging from 34 to as low as 31F. We could
see some slippery road conditions develop with this initial rain
falling on dry pavement. Air temperatures should rise above freezing
across the board by 15z/10am, so any icing would melt quickly.
However, any ice on initially dry roads can be very slippery.
Will follow the HRRR depiction of rain advancing eastward in a band
that matches the current radar trends rather closely. Likely and
categorical PoPs this morning will be confined to the western
counties where low level saturation will occur the soonest.
The band of warm F-gen will gradually shift north this afternoon,
giving the precip a northward push as well. Have kept likely PoPs
across the northern half of our area through the afternoon.
Instability params support elevated thunderstorms today, generally
in the southwest half of our forecast area.
High temps today will be held in check by the cool east-northeast
flow that will persist through the day. Most areas will see the
mid-upper 40s this afternoon.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 329 AM CDT TUE MAR 24 2015
Deepening surface low pressure currently at 1006 mb over the OK
panhandle to eject ne into the IL river valley over central IL by
06Z/1 am tonight and then to southern part of Lake MI by 12Z/7 am
Wed and swing a cold front through central and eastern IL overnight.
Showers likely ahead of this front along with chances of
thunderstorms. SPC has marginal risk over much of central IL
(excluding Knox, Stark and Marshall counties) with slight risk of
severe storms this evening across central and sw MO from St Louis
southwest. Lows tonight range from upper 30s to near 40F over IL
river valley to upper 40s and lower 50s in southeast IL.
Central IL to be inbetween weather systems during the day Wed as low
pressure passes ne of the Great Lakes and another surface low
pressure organizes over the southern plains. Isolated showers and
thunderstorms to be possible later Wed afternoon south of I-72.
Milder highs Wed mostly in the 60s, ranging from around 60F from
Peoria north to upper 60s and lower 70s in southeast IL. 1007 mb low
pressure to track ne into far southern IL by 06Z/1 AM Wed night and
up the Ohio river to near the OH/KY border by dawn Thu. Models have
trended further south with this low pressure track, and SPC has
shifted slight risk of severe storms Wed night south of our CWA with
marginal risk into southeast counties along and south of I-70. Heavy
rains of 1-1.5 inches possible south of I-70 Wed night while rain
chances taper off to 20-30% nw of the IL river. Lows Wed night range
from mid 30s over IL river valley to 40-45F in southeast IL from I-70
southeast.
Lingered a chance of rain showers in southeast IL Thu morning then
low pressure moves into southcentral PA by midday Thu and far enough
way to end rain chances Thu afternoon. Much cooler highs Thu in the
mid to upper 40s central IL and near 50F southeast IL. Even colder
Friday with highs in the upper 30s and lower 40s, coolest from I-74
ne. Models have been consistent in digging strong upper level trof
into the eastern states Thu/Fri bringing in the very cool
temperatures. 1030 mb Canadian high pressure settles into the Great
Lakes region Fri night and Sat with clouds and winds decreasing and
continued cold temps. Lows Fri night in the low to mid 20s. Highs
Sat in the low to mid 40s.
A cutoff upper level low passes north of the Great Lakes Sunday
keeping best chances of precipitation north of central IL, though
did carry small chances of light rain showers Sunday. Milder highs
Sunday and Monday in the mid to upper 50s with west central IL
around 60F.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1105 PM CDT MON MAR 23 2015
Main concern will be with the threat for a brief period of light
freezing rain at SPI and possibly as far east as DEC in the 10z-
14z time frame. Surface temperatures will be right around the
freezing mark through this time frame so some light icing is not
out of the question before temperatures edge into the middle 30s
by mid to late morning. Further north and east, the latest short
term models suggest the precip may struggle to shift north before
15z so will hold back the precip threat up at PIA and BMI until
after 15z. By then, it appears the precip would be mostly rain
with the possibility for some isolated convection over parts of
west central and central IL during the morning. For now, will hold
off mentioning any -tsra during the morning withe better threat
for isolated thunderstorms coming along tomorrow night. MVFR and
local IFR cigs will prevail thru most of this forecast period with
periods of rain into tomorrow evening as a storm system is
expected to track right over our area Tuesday night.
Surface winds will remain out of the northeast to east tonight at
10 to 15 kts and then easterly winds will prevail Tuesday with a
gradual turn into the southeast and then south Tuesday evening as
the surface low approaches our area. Wind speeds tomorrow will
range from 12 to 17 kts with gusts around 22 kts at times,
especially during the afternoon and evening hours.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...07
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1147 PM CDT MON MAR 23 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 339 PM CDT MON MAR 23 2015
OVERNIGHT FORECAST BECOMING COMPLICATED BY STRATUS DEVELOPMENT
TODAY AND MUCH COOLER HIGHS THAN ANTICIPATED. WITH NORTHEAST FLOW
AT THE SURFACE...DEW POINTS WILL REMAIN IN THE MID TO UPPER 20S FOR
THE OVERNIGHT HOURS UNTIL WINDS BECOME MORE SOUTHEAST AFTER 06Z. THIS
SHOULD ACT TO CAP ANY COOLING OVER THE SOUTH AND ACTUALLY RESULT IN
A EITHER STEADY OR A SLOW RISE IN TEMPERATURE AND DEW POINTS OVER
THE REGION BY 12Z. SOUNDINGS CONTINUE TO SHOW DRY AIR IN THE
FORECAST AREA WILL NEED TO BE OVERCOME PRIOR TO ANY PRECIPITATION
REACHING THE GROUND. THE GFS/NAM ARE MOST AGGRESSIVE WITH
SATURATION...THOUGH THE GFS HAS BACKED OFF A BIT ON THE ONSET OF
PRECIPITATION. THE EURO HAS BEEN SIMILAR IN THE PAST 2 MODEL
SOLUTIONS IN DELAYING MOST OF THE PRECIPITATION WITH THE EXCEPTION
OF THE FAR SOUTH UNTIL 09-12Z. AFTER LOOKING AT THE HRRR AND SEEING
THAT THE MESO SCALE MODELS ARE CONTINUING WITH AN EARLIER
ONSET...HAVE TAKEN A BLEND OF THE EURO/GFS SOLUTIONS. BACKED OFF A
BIT ON THE ONSET FROM THE PREVIOUS PACKAGE AND ALSO HAVE TRIMMED
BACK THUNDER CHANCES OVER THE SOUTH WITH ONLY THE FAR SOUTH LIKELY
TO SEE ANY ISO THUNDER THROUGH 12Z. THOUGH MOST OF ANY PRECIPITATION
THAT FALLS SHOULD REMAIN LIQUID...THERE IS STILL A RISK FOR SOME
LIGHT FREEZING RAIN ON THE NORTHERN EDGE OF THE PRECIPITATION SHIELD
AND OVER SOUTHEAST SECTIONS AS THE PRECIPITATION COMMENCES. THIS IS
MAINLY DUE TO TODAYS LACK OF DAYTIME HEATING...THE RELATIVELY DRY
AIR AND THE EXPECTATION THAT OVERNIGHT LOWS OVER THOSE AREAS WILL
LIKELY BE AT OR JUST BELOW THE FREEZING MARK BY SUNRISE. WITH
LIMITED MOISTURE EXPECTED OVERNIGHT...WILL NOT HAVE ANY HEADLINES AT
THIS TIME DUE TO THE POTENTIAL OF MAINLY VERY LIGHT ACCUMULATIONS OF
A HUNDREDTH OR TWO. LOWS WILL RANGE FROM THE 20S NORTHEAST TO THE
LOWER TO MID 30S OVER THE SOUTHWEST.
.LONG TERM /TUESDAY THROUGH MONDAY/...
ISSUED AT 339 PM CDT MON MAR 23 2015
PRECIPITATION EXPECTED TO BE ONGOING ACROSS THE SOUTHERN HALF OF
THE CWA AND WILL CONTINUE TO SPREAD NORTH ACROSS THE REMAINDER OF
THE CWA TUESDAY AS A DOUBLE-BARRELED UPPER LEVEL SYSTEM IMPACTS
THE REGION. INITIAL WAVE ROTATING THROUGH THE BASE OF THE OTHER
LOW TO SWING THROUGH IOWA LATE TUESDAY INTO TUESDAY NIGHT BRINGING
THE MAJORITY OF THE CHANGES OF PRECIPITATION THROUGH WEDNESDAY
NIGHT. WARM FRONT ALOFT TO LIFT NORTHWARD THROUGH THE CWA...WAA
AND MOISTURE ADVECTION IN PLACE ACROSS MUCH OF THE AREA TUESDAY.
STILL EXPECTING A MAIN AREA OF WAA PRECIP TO LIFT THROUGH THE CWA
TUESDAY MORNING...WITH A DRY PERIOD ACROSS PORTIONS OF
CENTRAL/SOUTHERN IOWA MOST LIKELY LATER TUESDAY MORNING INTO EARLY
AFTERNOON. SHOWER AND POTENTIAL ISOLATED THUNDERSTORM
REDEVELOPMENT EXPECTED IN THE AFTERNOON HOURS...AS THE MAIN UPPER
LOW MOVES OVERHEAD. WIDESPREAD PRECIPITATION EXPECTED ACROSS THE
ENTIRE CWA WITH THE MAIN LOW MOVING THROUGH...WITH PRECIPITATION
EXPECTED TO TAPER OFF FROM WEST TO EAST TUESDAY EVENING AS THE
UPPER LOW PUSHES EAST NORTHEAST INTO THE GREAT LAKES REGION.
CONTINUE TO SEE CHANCES FOR ELEVATED THUNDER ACROSS THE SOUTHERN
HALF OF THE CWA TUESDAY INTO TUESDAY EVENING. DYNAMIC COOLING OF
THE COLUMN WITH MORE INTENSE PRECIPITATION AREAS SHOULD ALLOW FOR
A MIXING OF RAIN/SNOW OR COMPLETE CHANGEOVER TO ALL SNOW ACROSS
THE FAR NORTHERN AREAS LATE TUESDAY AFTERNOON INTO TUESDAY
EVENING. A QUICK INCH OR TWO OF SNOW IS POSSIBLE BEFORE
PRECIPITATION CHANCES TAPER OFF TUESDAY EVENING. WIDESPREAD HALF
INCH QPF AMOUNTS CAN BE EXPECTED FROM THIS SYSTEM.
SECOND LOBE OF THE UPPER LEVEL SYSTEM TO DROP SOUTHWARD TOWARD THE
AREA WEDNESDAY...WITH A COLD FRONT DROPPING THROUGH THE CWA. MAY
HAVE SOME PRECIPITATION FORM ALONG AND AHEAD OF THE COLD FRONT BY
LATE AFTERNOON ACROSS FAR SOUTHERN IOWA. ARCTIC HIGH PRESSURE TO
THEN BUILD INTO THE REGION FOR THURSDAY INTO FRIDAY...WITH H85
TEMPS DROPPING INTO THE TEENS BELOW CELSIUS. THIS SHOULD ALLOW
TEMPS ACROSS THE AREA TO REMAIN WELL BELOW AVERAGE TO CLOSE OUT
THE WEEK. THE HIGH QUICKLY SHOVES SOUTHEAST THROUGH AS THE THERMAL
RIDGE BUILDS IN ALOFT OVER THE UPCOMING WEEKEND WITH UPPER LEVEL
RIDGING BUILDING INTO THE CENTRAL US. THEREFORE TEMPS SHOULD WARM
BACK TO NEAR THE SEASONAL AVERAGES OR ABOVE BY SUNDAY AND INTO
EARLY NEXT WEEK.
&&
.AVIATION...24/06Z
ISSUED AT 1144 PM CDT MON MAR 23 2015
LOW CEILINGS WILL REMAIN FOR MUCH OF THE FORECAST WITH MVFR TO IFR
CEILINGS THROUGH TUESDAY EVENING AS MOIST EASTERLY NEAR SURFACE
FLOW PERSISTS. ANTICIPATE SOME CONVECTION MOVING INTO SOUTHERN
IOWA LATE TONIGHT AND SPREADING NORTHWARD DURING THE DAY. ISOLD TO
SCT CONVECTION SEEMS POSSIBLE THROUGH TOMORROW EVENING WITH
ELEVATED INSTABILITY ALTHOUGH DIDNT HIT IT TOO HARD YET IN THE
TAF SINCE IT IS A WAYS OUT. VISIBILITIES WILL SEE SOME
RESTRICTIONS INTO TUESDAY AS WELL WITH THE RAIN AND SOME LIGHT
FOG. OVERALL...GENERALLY FAIR TO POOR CONDITIONS FOR AVIATION
THROUGH THE PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...BEERENDS
AVIATION...COGIL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
219 AM CDT TUE MAR 24 2015
...UPDATED FOR LONG TERM...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 150 AM CDT TUE MAR 24 2015
NAM BUFR SOUNDINGS INDICATING A 3000 TO 3500FT AGL MOIST LAYER
NEAR THE SURFACE ACROSS NORTH CENTRAL KANSAS EARLY THIS MORNING.
THIS MOISTURE ALONG WITH SOME WEAK LIFT IN LAYER WILL BE OCCURRING
UNDER A LAYER OF WARM 800 TO 700MB TEMPERATURES THROUGH 15Z. WILL
THEREFORE TREND TOWARDS HIGH CHANCES FOR LIGHT PRECIPITATION EARLY
THIS MORNING NORTH OF HIGHWAY 96. WILL ALSO KEEP A MENTION OF
THUNDER GOING GIVEN THE IMPROVING INSTABILITY EXPECTED UNDER THE
500MB COOL POOL THAT WILL BE CROSSING WESTERN KANSAS BETWEEN 12Z
AND 18Z TUESDAY.
FOR THE REMAINDER OF THE DAY...THE MODELS THIS MORNING STILL
INDICATING A MIXED LAYER DEPTH UP TO AROUND THE 750MB LEVEL DURING
THE AFTERNOON. USING THESE TEMPERATURES AS A GUIDE TODAY FOR HIGHS
TODAY THE CURRENT FORECAST WILL LOOKS ON TRACK WITH HIGHS MAINLY
IN THE LOW TO MID 70S. 00Z NAM AND 00Z GFS BOTH INDICATED THIS
MORNING THAT THE MEAN MIXED LAYER WINDS IN THIS DEPTH WILL NOT AS
STRONG AS WHAT THE PREVIOUS RUNS SUGGESTED. WILL HAVE SOME 35 TO
45 KNOTS IN THE 850MB TO 800MB LEVEL EARLY THIS MORNING BUT BY 18Z
THE MEAN WIND SPEEDS ARE FORECAST TO WEAKEN INTO THE 25 TO 35 KNOT
RANGE. THIS STILL SUGGESTS A PERIOD OF GUSTY NORTHWEST WIND AT 20
TO NEAR 30 MPH EARLY THIS AFTERNOON, MAINLY ACROSS NORTHWEST AND
SOUTH CENTRAL KANSAS. GIVE THESE EXPECTED WINDS ALONG WITH THE
RELATIVE HUMIDITY VALUES RANGING FROM 10 TO 15 PERCENT DURING THE
AFTERNOON HOURS WILL CONTINUE TO HIGHLIGHT CRITICAL FIRE WEATHER
CONDITIONS TODAY AND KEEP THE RED FLAG WARNING GOING. A FEW AREAS
MAY STRUGGLE TO REACH THE WIND CRITERIA BUT IT WILL BE CLOSE.
TONIGHT ANOTHER UPPER LEVEL DISTURBANCE WILL EXIT THE PACIFIC
NORTHWEST AND MOVE INTO THE CENTRAL ROCKIES. AHEAD OF THIS
APPROACHING UPPER LEVEL SYSTEM MID AND HIGH LEVEL MOISTURE WILL
INCREASE ACROSS WESTERN KANSAS DURING THE OVERNIGHT HOURS. AS THIS
HIGH CLOUDS INCREASE ACROSS WESTERN KANSAS A COLD FRONT WILL BE
MOVING SOUTH OUT OF NEBRASKA AND INTO WESTERN KANSAS BY EARLY
WEDNESDAY MORNING. AT THIS TIME GIVEN THE LOCATION OF THE FRONT
EARLY WEDNESDAY MORNING AND THE EXPECTED CLOUD COVER WILL TREND
TOWARDS THE WARMER GUIDANCE FOR OVERNIGHT LOWS, ESPECIALLY IN
SOUTH CENTRAL KANSAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 216 AM CDT TUE MAR 24 2015
FOR WEDNESDAY A SHORTWAVE TROUGH WILL BE SWINGING ACROSS THE CENTRAL
PLAINS WITH INCREASING CLOUDINESS AND A COLD FRONT. CHANCES FOR ANY
MEASURABLE PRECIP WILL BE NILL WITH THIS WAVE WITH ONLY MID LEVEL
MOISTURE AVAILABLE. HIGHS WILL BE GENERALLY FROM 60 TO 65 DEGREES
WITH GUSTY NORTH WINDS OF 20 TO 30 MPH BY AFTERNOON.
DRY NORTHWEST FLOW ALOFT FOLLOWS INTO NEXT WEEKEND. HIGHS WILL BE
AROUND 60 ON THURSDAY AS COLDER HIGH PRESSURE SETTLES INTO THE
CENTRAL PLAINS. AS THE COLD SURFACE HIGH RETREATS, WARMER WINDS FROM
THE SOUTH DEVELOP ON FRIDAY WITH HIGHS FROM 60 TO 65. A WARMING
TREND CONTINUES INTO THE WEEKEND WITH HIGHS IN THE 70S INTO EARLY
NEXT WEEK. OVERNIGHT LOWS LOOK TO RANGE FROM 30 TO 35 INTO FRIDAY
MORNING, THEN WARMING INTO THE 40S FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1202 AM CDT TUE MAR 24 2015
OVERNIGHT AS THE FIRST IN A SERIES OF UPPER LEVEL DISTURBANCES
CROSSES INTO CENTRAL KANSAS THE EASTERLY WINDS OVER SOUTHWEST
KANSAS WILL SHIFT TO THE NORTHWEST AND RANGE FROM 10 TO NEAR 15
KNOTS. AS THE WINDS SHIFT TO THE NORTH/NORTHWEST THE 00Z BUFR
SOUNDING DOES INDICATED THE THE MOISTURE NEAR THE SURFACE WILL
INCREASE. THE DEPTH OF THIS MOIST LAYER TOWARDS 12Z TUESDAY IN
HAYS WILL RANGE FROM 3000 TO 4000 FT AGL WHILE AT DDC AND GCK WILL
BE LESS THAN 1500FT AGL. GIVEN THE DEPTH OF THIS MOIST LAYER
BETWEEN 09Z AND 15Z TUESDAY THERE WILL BE A CHANCE FOR LIGHT
PRECIPITATION AS CEILINGS AND VISIBILITIES LOWER INTO THE MVFR/IFR
CATEGORY IN THE HYS AREA. FURTHER SOUTH HRRR AND BUFR SOUNDINGS
INDICATED THE POTENTIAL FOR A BRIEF PERIOD OF MVFR CEILINGS AND
MAINLY IN THE DDC AREA.
AFTER 12Z TUESDAY ANOTHER UPPER LEVEL DISTURBANCE WILL CROSS
WESTERN KANSAS AS AS THIS NEXT SYSTEM PASSES SKIES WILL CLEAR AND
GUSTY NORTHWEST WINDS WILL DEVELOP. ACROSS ALL OF WESTERN KANSAS
THE GUSTY NORTHWEST WINDS WILL RANGE FROM 20 TO NEAR 25 KNOT RANGE
BETWEEN 15Z AND 21Z TUESDAY AND THEN GRADUALLY FALL BACK INTO THE
10 TO 15 KNOT RANGE BY 00Z WEDNESDAY.
&&
.FIRE WEATHER...
ISSUED AT 150 AM CDT TUE MAR 24 2015
GUSTY NORTHWEST WINDS WILL DEVELOP BY LATE MORNING AND CONTINUE
THROUGH THE LATE AFTERNOON. SUSTAINED WIND SPEEDS OF 20 TO NEAR 30
MPH CAN BE EXPECTED WITH HIGHER GUSTS POSSIBLE. IN ADDITION TO THE
INCREASING WINDS THE AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL
BACK INTO THE 10 TO 15 PERCENT RANGE BY 3 PM. THE COMBINATION OF
THESE RELATIVE HUMIDITY VALUES AND VERY WINDY CONDITIONS WILL
CREATE A FAVORABLE ENVIRONMENT WHERE RAPID WILDFIRE GROWTH WILL
OCCUR. ANY OUTDOOR BURNING TODAY SHOULD BE AVOIDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 72 40 65 32 / 0 0 10 10
GCK 71 38 62 30 / 0 0 10 10
EHA 71 41 63 34 / 0 0 10 10
LBL 73 40 65 33 / 0 0 10 10
HYS 70 39 60 30 / 30 0 10 10
P28 75 43 69 36 / 10 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 7 PM
CDT /6 PM MDT/ THIS EVENING FOR KSZ030-031-043>046-061>066-
074>081-084>090.
&&
$$
SHORT TERM...BURGERT
LONG TERM...KRUSE
AVIATION...BURGERT
FIRE WEATHER...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
153 AM CDT TUE MAR 24 2015
...UPDATED SHORT TERM AND FIRE WEATHER DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 150 AM CDT TUE MAR 24 2015
NAM BUFR SOUNDINGS INDICATING A 3000 TO 3500FT AGL MOIST LAYER
NEAR THE SURFACE ACROSS NORTH CENTRAL KANSAS EARLY THIS MORNING.
THIS MOISTURE ALONG WITH SOME WEAK LIFT IN LAYER WILL BE OCCURRING
UNDER A LAYER OF WARM 800 TO 700MB TEMPERATURES THROUGH 15Z. WILL
THEREFORE TREND TOWARDS HIGH CHANCES FOR LIGHT PRECIPITATION EARLY
THIS MORNING NORTH OF HIGHWAY 96. WILL ALSO KEEP A MENTION OF
THUNDER GOING GIVEN THE IMPROVING INSTABILITY EXPECTED UNDER THE
500MB COOL POOL THAT WILL BE CROSSING WESTERN KANSAS BETWEEN 12Z
AND 18Z TUESDAY.
FOR THE REMAINDER OF THE DAY...THE MODELS THIS MORNING STILL
INDICATING A MIXED LAYER DEPTH UP TO AROUND THE 750MB LEVEL DURING
THE AFTERNOON. USING THESE TEMPERATURES AS A GUIDE TODAY FOR HIGHS
TODAY THE CURRENT FORECAST WILL LOOKS ON TRACK WITH HIGHS MAINLY
IN THE LOW TO MID 70S. 00Z NAM AND 00Z GFS BOTH INDICATED THIS
MORNING THAT THE MEAN MIXED LAYER WINDS IN THIS DEPTH WILL NOT AS
STRONG AS WHAT THE PREVIOUS RUNS SUGGESTED. WILL HAVE SOME 35 TO
45 KNOTS IN THE 850MB TO 800MB LEVEL EARLY THIS MORNING BUT BY 18Z
THE MEAN WIND SPEEDS ARE FORECAST TO WEAKEN INTO THE 25 TO 35 KNOT
RANGE. THIS STILL SUGGESTS A PERIOD OF GUSTY NORTHWEST WIND AT 20
TO NEAR 30 MPH EARLY THIS AFTERNOON, MAINLY ACROSS NORTHWEST AND
SOUTH CENTRAL KANSAS. GIVE THESE EXPECTED WINDS ALONG WITH THE
RELATIVE HUMIDITY VALUES RANGING FROM 10 TO 15 PERCENT DURING THE
AFTERNOON HOURS WILL CONTINUE TO HIGHLIGHT CRITICAL FIRE WEATHER
CONDITIONS TODAY AND KEEP THE RED FLAG WARNING GOING. A FEW AREAS
MAY STRUGGLE TO REACH THE WIND CRITERIA BUT IT WILL BE CLOSE.
TONIGHT ANOTHER UPPER LEVEL DISTURBANCE WILL EXIT THE PACIFIC
NORTHWEST AND MOVE INTO THE CENTRAL ROCKIES. AHEAD OF THIS
APPROACHING UPPER LEVEL SYSTEM MID AND HIGH LEVEL MOISTURE WILL
INCREASE ACROSS WESTERN KANSAS DURING THE OVERNIGHT HOURS. AS THIS
HIGH CLOUDS INCREASE ACROSS WESTERN KANSAS A COLD FRONT WILL BE
MOVING SOUTH OUT OF NEBRASKA AND INTO WESTERN KANSAS BY EARLY
WEDNESDAY MORNING. AT THIS TIME GIVEN THE LOCATION OF THE FRONT
EARLY WEDNESDAY MORNING AND THE EXPECTED CLOUD COVER WILL TREND
TOWARDS THE WARMER GUIDANCE FOR OVERNIGHT LOWS, ESPECIALLY IN
SOUTH CENTRAL KANSAS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 210 PM CDT MON MAR 23 2015
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TRANSITIONING
EASTWARD OUT OF THE NORTHERN PLAINS INTO THE GREAT LAKES REGION
WEDNESDAY SENDING AN ATTENDANT COLD FRONT SOUTHWARD ACROSS WESTERN
KANSAS. HOWEVER, A FAIRLY WEAK FLOW ALOFT COMBINED WITH A LACK OF
LOW/MID LEVEL MOISTURE AND LITTLE INSTABILITY PRESENT WILL RESULT
IN GENERALLY DRY CONDITIONS ACROSS WESTERN KANSAS THROUGH THURSDAY
AFTERNOON, ALTHOUGH A FEW SPRINKLES/LIGHT RAIN CANNOT BE RULED OUT
BEHIND THE FRONT WEDNESDAY NIGHT. RIDGING ALOFT IS PROJECTED TO
PUSH ASHORE OFF THE PACIFIC THURSDAY SETTING UP A NORTHWEST FLOW
ALOFT ACROSS THE WESTERN HIGH PLAINS. AN OUTSIDE CHANCE FOR PRECIP
MAY PICK UP A LITTLE THURSDAY NIGHT AS AN H5 VORT MAXIMA TRACKS
SOUTHEAST ACROSS THE NORTHERN PLAINS. HOWEVER, LOW/MID LEVEL
MOISTURE WILL REMAIN MINIMAL AT BEST LIMITING PRECIP CHANCES TO A
FEW ISOLATED SHOWERS WITH THE POTENTIAL FOR A SNOW MIX LATE
THURSDAY NIGHT.
COOLER TEMPERATURES ARE LIKELY WEDNESDAY IN WAKE OF A COLD FRONT
PUSHING SOUTHWARD ACROSS WESTERN KANSAS. COLDER AIR FILTERING DOWN
INTO THE AREA WILL LOWER H85 TEMPERATURES FROM THE TEENS(C) THE DAY
PREVIOUS WELL DOWN INTO THE SINGLE DIGITS(C) BY WEDNESDAY AFTERNOON.
LOOK FOR HIGHS GENERALLY UP INTO THE 60S(F) WITH A FEW UPPER 50S(F)
POSSIBLE NEAR THE I-7O CORRIDOR AND NEAR 70F POSSIBLE IN SOUTH
CENTRAL KANSAS DEPENDING ON THE TIMING OF THE FRONT. EXPECT HIGHS
ONLY UP INTO THE 50S(F) ACROSS CENTRAL KANSAS THURSDAY AS SURFACE
HIGH PRESSURE ACROSS THE NORTHERN PLAINS CONTINUES TO HELP EDGE THE
COOLER AIR MASS FURTHER SOUTHWEST INTO THE HIGH PLAINS. NEAR 60F IS
STILL POSSIBLE IN EXTREME SOUTHWEST KANSAS. SIMILAR HIGH
TEMPERATURES ARE EXPECTED THROUGH THE END OF THE WEEK WITH THE AIR
MASS ACROSS THE HIGH PLAINS UNDERGOING LITTLE CHANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1202 AM CDT TUE MAR 24 2015
OVERNIGHT AS THE FIRST IN A SERIES OF UPPER LEVEL DISTURBANCES
CROSSES INTO CENTRAL KANSAS THE EASTERLY WINDS OVER SOUTHWEST
KANSAS WILL SHIFT TO THE NORTHWEST AND RANGE FROM 10 TO NEAR 15
KNOTS. AS THE WINDS SHIFT TO THE NORTH/NORTHWEST THE 00Z BUFR
SOUNDING DOES INDICATED THE THE MOISTURE NEAR THE SURFACE WILL
INCREASE. THE DEPTH OF THIS MOIST LAYER TOWARDS 12Z TUESDAY IN
HAYS WILL RANGE FROM 3000 TO 4000 FT AGL WHILE AT DDC AND GCK WILL
BE LESS THAN 1500FT AGL. GIVEN THE DEPTH OF THIS MOIST LAYER
BETWEEN 09Z AND 15Z TUESDAY THERE WILL BE A CHANCE FOR LIGHT
PRECIPITATION AS CEILINGS AND VISIBILITIES LOWER INTO THE MVFR/IFR
CATEGORY IN THE HYS AREA. FURTHER SOUTH HRRR AND BUFR SOUNDINGS
INDICATED THE POTENTIAL FOR A BRIEF PERIOD OF MVFR CEILINGS AND
MAINLY IN THE DDC AREA.
AFTER 12Z TUESDAY ANOTHER UPPER LEVEL DISTURBANCE WILL CROSS
WESTERN KANSAS AS AS THIS NEXT SYSTEM PASSES SKIES WILL CLEAR AND
GUSTY NORTHWEST WINDS WILL DEVELOP. ACROSS ALL OF WESTERN KANSAS
THE GUSTY NORTHWEST WINDS WILL RANGE FROM 20 TO NEAR 25 KNOT RANGE
BETWEEN 15Z AND 21Z TUESDAY AND THEN GRADUALLY FALL BACK INTO THE
10 TO 15 KNOT RANGE BY 00Z WEDNESDAY.
&&
.FIRE WEATHER...
ISSUED AT 150 AM CDT TUE MAR 24 2015
GUSTY NORTHWEST WINDS WILL DEVELOP BY LATE MORNING AND CONTINUE
THROUGH THE LATE AFTERNOON. SUSTAINED WIND SPEEDS OF 20 TO NEAR 30
MPH CAN BE EXPECTED WITH HIGHER GUSTS POSSIBLE. IN ADDITION TO THE
INCREASING WINDS THE AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL
BACK INTO THE 10 TO 15 PERCENT RANGE BY 3 PM. THE COMBINATION OF
THESE RELATIVE HUMIDITY VALUES AND VERY WINDY CONDITIONS WILL
CREATE A FAVORABLE ENVIRONMENT WHERE RAPID WILDFIRE GROWTH WILL
OCCUR. ANY OUTDOOR BURNING TODAY SHOULD BE AVOIDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 72 40 65 32 / 0 0 10 10
GCK 71 38 64 30 / 0 0 10 10
EHA 71 41 64 34 / 0 0 10 10
LBL 73 40 67 34 / 0 0 10 10
HYS 70 39 62 31 / 30 0 10 10
P28 75 43 68 36 / 10 0 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 7 PM
CDT /6 PM MDT/ THIS EVENING FOR KSZ030-031-043>046-061>066-
074>081-084>090.
&&
$$
SHORT TERM...BURGERT
LONG TERM...JJOHNSON
AVIATION...BURGERT
FIRE WEATHER...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1207 AM CDT TUE MAR 24 2015
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1202 AM CDT TUE MAR 24 2015
AT 00Z TUESDAY ONE UPPER LEVEL TROUGH WAS LOCATED OVER SOUTHWEST
KANSAS WITH ANOTHER UPPER LEVEL SYSTEM BEING LOCATED OVER NORTHERN
COLORADO. FURTHER WEST A THIRD, STRONGER, UPPER LEVEL TROUGH WAS
EVIDENT FROM WATER VAPOR LOOP AND 500MB ANALYSIS OVER EASTERN
IDAHO/NORTHERN UTAH. THIS THIRD UPPER LEVEL TROUGH WAS ASSOCIATED
WITH THE LEFT EXIT REGION OF A 250MB JET STREAK. OVER THE
CENTRAL/SOUTHERN HIGH PLAINS AT 00Z TUESDAY AN AREA OF +5 TO +6C
700MB TEMPERATURES EXTENDED FROM EASTERN COLORADO INTO NORTH EAST
NEW MEXICO AND THE PANHANDLE OF TEXAS. THE NORTHERN EDGE OF THESE
WARM TEMPERATURES STRETCHED FROM NORTHEAST COLORADO INTO NORTH
WEST OKLAHOMA. AN 850MB WARM FRONT EXTENDED FROM SOUTHEAST
COLORADO INTO SOUTHWEST OKLAHOMA WITH A WEDGE OF HIGHER DEW POINTS
BEGIN LOCATED FROM DODGE CITY SOUTH AND SOUTHEAST. A SURFACE WARM
FRONT AT 00Z TUESDAY WAS LOCATED ALONG THE KANSAS AND OKLAHOMA
BORDER.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 333 PM CDT MON MAR 23 2015
MURPHY`S LAW IS IN EFFECT THIS EVENING. MORE IMPORTANTLY, TODAY ILLUSTRATES
HOW FICKLE MESOSCALE METEOROLOGY IS. THE WARM FRONT WITH ALL THE HIGHER
DEWPOINTS HAS BARELY MOVED NORTHWARD THIS AFTERNOON. IN ADDITION, CLOUDS
HAVE DEVELOPED ACROSS SOUTHWEST KANSAS KEEPING TEMPERATURES COOL. THE
NET RESULT IS THAT INSTABILITY IS NON-EXISTENT RIGHT NOW. HAVE SERIOUS
DOUBTS THAT ANY THUNDERSTORMS WILL FORM. I HAVE KEPT CHANCE POPS ACROSS
THE EASTERN ZONES JUST IN CASE THE 4 KM NAM IS CORRECT. AGAIN, IT WOULD
TAKE SOME SERIOUS AIR MASS MODIFICATION IN A SHORT PERIOD OF TIME FOR
EVENING THUNDERSTORMS. THERE MIGHT BE SLIGHTLY MORE CONDUCIVE METEOROLOGY
AFTER DARK AS THE LOW LEVEL JET STRENGTHENS. OTHER MODELS ARE SUGGESTING
WHAT I AM NOW THINKING... WE WON`T SEE SQUAT. SEVERE THUNDERSTORMS AND
HAIL ARE BECOMING VERY UNLIKELY AS WELL. LOWS TONIGHT WILL BE IN THE
40S. HIGHS TOMORROW WILL BE IN THE 70S. IT WILL BE WINDY AND DEWPOINTS
WILL MIX OUT. HAVE A RED FLAG WARNING FOR THE ENTIRE REGION AS A RESULT
AS CRITICAL FIRE WEATHER CONDITIONS ARE VERY LIKELY. DO NOT BURN TOMORROW.
OTHER THAN TONIGHT INTO THE OVERNIGHT HOURS, POPS WILL TREND TO ZERO
PERCENT BY THE EARLY AFTERNOON. THERE MAYBE SOME DRIZZLE IN THE MORNING,
BUT THIS ISN`T IN THE FORECAST DUE TO UNCERTAINTY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 210 PM CDT MON MAR 23 2015
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TRANSITIONING
EASTWARD OUT OF THE NORTHERN PLAINS INTO THE GREAT LAKES REGION
WEDNESDAY SENDING AN ATTENDANT COLD FRONT SOUTHWARD ACROSS WESTERN
KANSAS. HOWEVER, A FAIRLY WEAK FLOW ALOFT COMBINED WITH A LACK OF
LOW/MID LEVEL MOISTURE AND LITTLE INSTABILITY PRESENT WILL RESULT
IN GENERALLY DRY CONDITIONS ACROSS WESTERN KANSAS THROUGH THURSDAY
AFTERNOON, ALTHOUGH A FEW SPRINKLES/LIGHT RAIN CANNOT BE RULED OUT
BEHIND THE FRONT WEDNESDAY NIGHT. RIDGING ALOFT IS PROJECTED TO
PUSH ASHORE OFF THE PACIFIC THURSDAY SETTING UP A NORTHWEST FLOW
ALOFT ACROSS THE WESTERN HIGH PLAINS. AN OUTSIDE CHANCE FOR PRECIP
MAY PICK UP A LITTLE THURSDAY NIGHT AS AN H5 VORT MAXIMA TRACKS
SOUTHEAST ACROSS THE NORTHERN PLAINS. HOWEVER, LOW/MID LEVEL
MOISTURE WILL REMAIN MINIMAL AT BEST LIMITING PRECIP CHANCES TO A
FEW ISOLATED SHOWERS WITH THE POTENTIAL FOR A SNOW MIX LATE
THURSDAY NIGHT.
COOLER TEMPERATURES ARE LIKELY WEDNESDAY IN WAKE OF A COLD FRONT
PUSHING SOUTHWARD ACROSS WESTERN KANSAS. COLDER AIR FILTERING DOWN
INTO THE AREA WILL LOWER H85 TEMPERATURES FROM THE TEENS(C) THE DAY
PREVIOUS WELL DOWN INTO THE SINGLE DIGITS(C) BY WEDNESDAY AFTERNOON.
LOOK FOR HIGHS GENERALLY UP INTO THE 60S(F) WITH A FEW UPPER 50S(F)
POSSIBLE NEAR THE I-7O CORRIDOR AND NEAR 70F POSSIBLE IN SOUTH
CENTRAL KANSAS DEPENDING ON THE TIMING OF THE FRONT. EXPECT HIGHS
ONLY UP INTO THE 50S(F) ACROSS CENTRAL KANSAS THURSDAY AS SURFACE
HIGH PRESSURE ACROSS THE NORTHERN PLAINS CONTINUES TO HELP EDGE THE
COOLER AIR MASS FURTHER SOUTHWEST INTO THE HIGH PLAINS. NEAR 60F IS
STILL POSSIBLE IN EXTREME SOUTHWEST KANSAS. SIMILAR HIGH
TEMPERATURES ARE EXPECTED THROUGH THE END OF THE WEEK WITH THE AIR
MASS ACROSS THE HIGH PLAINS UNDERGOING LITTLE CHANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1202 AM CDT TUE MAR 24 2015
OVERNIGHT AS THE FIRST IN A SERIES OF UPPER LEVEL DISTURBANCES
CROSSES INTO CENTRAL KANSAS THE EASTERLY WINDS OVER SOUTHWEST
KANSAS WILL SHIFT TO THE NORTHWEST AND RANGE FROM 10 TO NEAR 15
KNOTS. AS THE WINDS SHIFT TO THE NORTH/NORTHWEST THE 00Z BUFR
SOUNDING DOES INDICATED THE THE MOISTURE NEAR THE SURFACE WILL
INCREASE. THE DEPTH OF THIS MOIST LAYER TOWARDS 12Z TUESDAY IN
HAYS WILL RANGE FROM 3000 TO 4000 FT AGL WHILE AT DDC AND GCK WILL
BE LESS THAN 1500FT AGL. GIVEN THE DEPTH OF THIS MOIST LAYER
BETWEEN 09Z AND 15Z TUESDAY THERE WILL BE A CHANCE FOR LIGHT
PRECIPITATION AS CEILINGS AND VISIBILITIES LOWER INTO THE MVFR/IFR
CATEGORY IN THE HYS AREA. FURTHER SOUTH HRRR AND BUFR SOUNDINGS
INDICATED THE POTENTIAL FOR A BRIEF PERIOD OF MVFR CEILINGS AND
MAINLY IN THE DDC AREA.
AFTER 12Z TUESDAY ANOTHER UPPER LEVEL DISTUBANCE WILL CROSS
WESTERN KANSAS AS AS THIS NEXT SYSTEM PASSES SKIES WILL CLEAR AND
GUSTY NORTHWEST WINDS WILL DEVELOP. ACROSS ALL OF WESTERN KANSAS
THE GUSTY NORTHWEST WINDS WILL RANGE FROM 20 TO NEAR 25 KNOT RANGE
BETWEEN 15Z AND 21Z TUESDAY AND THEN GRADUALLY FALL BACK INTO THE
10 TO 15 KNOT RANGE BY 00Z WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 65 32 58 / 0 10 10 0
GCK 36 64 30 58 / 0 10 10 10
EHA 41 64 34 60 / 0 10 10 10
LBL 38 67 34 60 / 0 10 10 10
HYS 38 62 31 55 / 0 10 10 0
P28 42 68 36 57 / 0 20 20 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 7 PM
CDT /6 PM MDT/ THIS EVENING FOR KSZ030-031-043>046-061>066-
074>081-084>090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...SUGDEN
LONG TERM...JJOHNSON
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
558 AM EDT TUE MAR 24 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 557 AM EDT TUE MAR 24 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MESSY COMPLEX OF
SHORTWAVE ENERGY MOVING ACROSS THE PACIFIC NW AND ROCKIES. LEAD
ENERGY IS ALREADY GENERATING SHRA/TSRA ACROSS THE CNTRL PLAINS EARLY
THIS MORNING. CLOSER TO HOME...SHORTWAVE RIDGE OVER MN IS SUPPORTING
SFC HIGH PRES OVER THE GREAT LAKES. ASSOCIATED DRY AIR
MASS/SUBSIDENCE AHEAD OF RIDGE IS RESULTING IN CLEAR SKIES ACROSS
THE UPPER LAKES EARLY THIS MORNING. WITH LIGHT/CALM WIND...TEMPS IN
THE INTERIOR E HALF HAVE FALLEN INTO THE LOWER TEENS AND SINGLE
DIGITS WITH A FEW SPOTS RECENTLY NEAR 0F. OUT W...20S ARE MORE
COMMON WITH A LIGHT S WIND STIRRING.
MID/UPPER RIDGE SHIFTING ACROSS THE WRN GREAT LAKES TODAY ALONG WITH
DRY AIR MASS WILL RESULT IN ABUNDANT SUNSHINE. HIGH WILL REACH THE
40S OVER THE MUCH OF THE W HALF. S TO SE WINDS OFF LAKE MI WILL KEEP
THE E HALF COOLER IN THE 30S...PROBABLY LOW 30S NEAR THE SHORE OF
LAKE MI.
TONIGHT...ATTENTION TURNS TO THE MULTIPLE SHORTWAVES CURRENTLY
MOVING ACROSS THE PACIFIC NW AND ROCKIES. LEAD ENERGY MOVING OUT
ACROSS NE/KS THIS AFTN IS STILL FCST TO TAKE ON A NEGATIVE TILT AS
IT MOVES TO VCNTY OF SRN LAKE MI BY 12Z WED WHILE ANOTHER SHORTWAVE
MOVES ACROSS THE DAKOTAS INTO MN. THIS WILL LEAD TO 2 SFC LOW
CENTERS AT 12Z WED...ONE OVER NW MN AND THE SECOND IN THE VCNTY OF
SRN LAKE MI. OVER THE LAST FEW DAYS...MODELS HAVE PERSISTENTLY
OVERALL TRENDED SLIGHTLY SE WITH EACH SUCCESSIVE MODEL RUN IN REGARD
TO THE SRN SHORTWAVE/SFC LOW. THAT TREND HAS CONTINUED WITH THE 00Z
MODELS. FOR THE FCST AREA...THIS MEANS HEAVIEST PCPN SHOULD PASS BY
TO THE SE OF HERE...AND PCPN SHOULD FALL ALMOST EXCLUSIVELY AS SNOW
AS IT ARRIVES FROM THE S AND SW LATE TONIGHT. THERE IS STILL JUST
ENOUGH UNCERTAINTY IN THERMAL PROFILES TO INCLUDE A MENTION OF -FZRA
CLOSE TO LAKE MI WHERE WARM NOSE ALOFT OF ABOVE FREEZING TEMPS WILL
COME CLOSE TO THAT AREA. UTILIZED MOSTLY A CONSENSUS APPROACH OF ALL
AVBL GUIDANCE...WEIGHTED TOWARD HIGH RES GUIDANCE (NAM/GEM AND NCEP
HRW-ARW/NMM)...TO CONSTRUCT POPS/QPF TONIGHT. RESULT IS PCPN
SPREADING N AND NE INTO THE FCST AREA AFTER 06Z. IT`S POSSIBLE THE
SNOW MAY NOT ARRIVE OVER THE FAR N AND E FCST AREA UNTIL AROUND 12Z
WED. RESULT FOR QPF IS ROUGHLY 0.10 TO 0.25 INCHES BY 12Z...HIGHEST
IN SRN MENOMINEE COUNTY. VIGOROUS DYNAMICS AND HEALTHY ISENTROPIC
ASCENT NOTED ON 290K SFC SHOULD LEAD TO DECENT PCPN RATES DURING
PEAK FORCING WHICH REACHES THE WI BORDER IN THE 09Z-12Z TIME FRAME.
ALTHOUGH MIXING RATIOS OF 3-4G/KG ARE AVBL AROUND 750MB...SHORT
DURATION OF STRONG FORCING AND LOWER SNOW TO WATER RATIOS DOWN TO 10-
15 TO 1 MAKE FOR LOWER CONFIDENCE ON SNOW ACCUMULATIONS REACHING
ADVY LEVEL. AT THIS POINT...CONSENSUS HERE IS TO HOLD OFF ON ADVY
HEADLINES...ESPECIALLY SINCE THIS IS A VERY LATE 2ND PERIOD AND 3RD
PERIOD EVENT. IF NEXT ROUND OF MODEL RUNS TODAY PAINT A SLIGHTLY
HIGHER QPF PICTURE...CAN FORESEE ADVY HEADLINES FOR POSSIBLY THE E
HALF OF THE FCST AREA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 517 AM EDT TUE MAR 24 2015
FCST MODELS CONTINUE TO MERGE ON A THEME OF HAVING THE INITIAL LOW
FROM THE SW OVER CENTRAL LAKE MI AROUND 12Z WEDNESDAY. THE RESULT
HAS BEEN A TREND TO LESS PRECIP AND MORE IN THE FORM OF SNOW INSTEAD
OF FREEZING RAIN WEDNESDAY MORNING.
PRECIP WILL OVERSPREAD THE REST OF THE CWA WEDNESDAY MORNING. THIS
QUICK BLAST OF MOISTURE WILL ALREADY BE PULLING OUT OF THE SW CORNER
OF UPPER MI BY 18Z WEDNESDAY...AND IF THE 23/18Z RUN OF THE CANADIAN
IS CORRECT MUCH OF THE SW AND CENTRAL CWA. THIS WILL BE WHILE THE
SFC LOW SHIFTS ACROSS E UPPER MI AND NW LAKE HURON BY 18Z...AND
GENERALLY BETWEEN CYLD AND CYXR IN SE ONTARIO BY 00Z THURSDAY. WITH
SFC TEMPS GETTING INTO THE UPPER 30S AND LOW 40S WEDNESDAY
AFTERNOON...SNOW WILL BE DIFFICULT TO MAINTAIN. WHILE A MIX IS
REPRESENTED IN THE FCST...UPPER MI WILL BE IN A LULL...WITH MUCH OF
THE BEST MOISTURE WILL BE ALREADY GONE.
UPDATED THE SPS TO INCLUDE THE COUNTIES OF MENOMINEE TO ALGER AND
E...WHERE THE GREATEST POTENTIAL FOR OVER 2IN OF SNOW EXISTS...ALONG
WITH A BRIEF PERIOD OF FREEZING RAIN.
WILL NEED TO WAIT UNTIL THE SECONDARY SFC LOW /OVER NW MN AT 12Z
WEDNESDAY/ EXITS THE PICTURE. IT SHOULD MOVE OVER NE MN AT 18Z
WEDNEDAY...AND JOIN FORCES WITH THE MAIN LOW EARLY WEDNESDAY EVENING
OVER LAKE SUPERIOR AND SE ONTARIO. 850MB TEMPS STILL AROUND -5C AT
00Z THURSDAY WILL FALL TO AROUND -15C OVER THE W BY 12Z THURSDAY ON
N-NW WINDS. THE RESULT...WITH THE ASSISTANCE OF THE SIZABLE 500MB
TROUGH OVERHEAD CONTINUING TO BRING A SERIES OF SHORTWAVES ACROSS
UPPER MI...WILL BE LIGHT TO AT TIMES MODERATE LES THROUGH THURSDAY
EVENING.
THE 500MB TROUGH WILL EVENTUALLY SHIFT TO OUR SE...MAKING WAY FOR A
RIDGE SATURDAY INTO EARLY SUNDAY. AT THIS POINT...WITH HIGH PRESSURE
AT THE SFC AND ALOFT...DRY WEATHER IS FIGURED FROM LATE MORNING
FRIDAY THROUGH THE DAY SATURDAY.
THE 00Z RUN OF THE ECMWF IS MORE ROBUST WITH THE PRECIP SUNDAY
MORNING. LOOKS LIKE ANOTHER POTENTIAL RAIN/SNOW SITUATION. WHILE THE
ECMWF WOULD INDICATE WARMER AIR AND A BETTER CHANCE OF RAIN...THE
GFS IS MUCH COOLER AND WOULD GIVE MAINLY RAIN. WILL CONTINUE WITH A
MODEL BLEND FOR THIS PERIOD...UNTIL A MORE SOLID CONSENSUS IS
DEVELOPED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 129 AM EDT TUE MAR 24 2015
VERY DRY AIR IN THE LOW TO MID LEVELS ASSOCIATED WITH HIGH PRES
BUILDING TOWARD THE ERN GREAT LAKES WILL BRING VFR CONDITIONS TO
KIWD/KCMX/KSAW THROUGH THE FCST PERIOD ALONG WITH LIGHT SOUTHERLY
WINDS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 557 AM EDT TUE MAR 24 2015
WITH HIGH PRES OVER THE GREAT LAKES REGION SHIFTING E WHILE LOW PRES
DEVELOPING OVER THE SRN PLAINS MOVES NE...WINDS WILL INCREASE TODAY
AND TONIGHT. SINCE PRES GRADIENT REMAINS RELATIVELY WEAK...WINDS
ACROSS LAKE SUPERIOR SHOULD REMAIN MOSTLY UNDER 20KT...THOUGH HIGH
OBS PLATFORMS WILL PROBABLY SEE SOME GUSTS TO AROUND 25KT. WINDS
WILL DIMINISH WED AS LOW PRES TROF SETS UP ACROSS THE LAKE BTWN ONE
LOW PRES CENTER MOVING E TOWARD LAKE SUPERIOR AND THE OTHER LIFTING
NE THRU LWR MI INTO ONTARIO. THE TROF WILL DROP S OF THE LAKE WED
NIGHT...AND WINDS WILL THEN INCREASE INTO THU AS HIGH PRES BUILDS S
TOWARD THE NRN PLAINS AND MUCH COLDER AIR SPREADS SE INTO THE UPPER
LAKES. NORTHERLY WINDS SHOULD INCREASE TO 20-30KT THU...AND IT`S NOT
OUT OF THE QUESTION THAT GALE FORCE GUSTS COULD OCCUR FOR A TIME
OVER CNTRL PORTIONS OF LAKE SUPERIOR. WINDS WILL THEN DIMINISH FRI
AS THE HIGH PRES ARRIVES OVER THE WRN GREAT LAKES. WIND WILL BEGIN
TO RAMP UP AGAIN SAT...ESPECIALLY LATE...AS THE HIGH SHIFTS TO THE
OHIO VALLEY AND LOW PRES DROPS SE INTO MANITOBA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
410 AM CDT TUE MAR 24 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT TUE MAR 24 2015
TOUGH FORECAST AHEAD FOR THIS AFTERNOON AND TONIGHT ON PTYPE AND
RESULTING PRECIPITATION AMOUNTS. THERE WAS QUITE THE DIFFERENCE
OUT THE GATE WITH THE 00Z RUNS BETWEEN THE NAM/GFS VERSUS THE
ECMWF/CANADIAN ON THE LAYOUT OF THE PRECIPITATION PATTERN
DEVELOPING LATER THIS AFTERNOON AND SPREADING ACROSS THE FA
TONIGHT. THE ECMWF AND CANADIAN ARE MUCH FARTHER SOUTH ON THE QPF
AXIS WITH A QUARTER INCH TONIGHT BARELY ACROSS THE SOUTHEAST PART
OF MN WHILE THE NAM/GFS HAVE THE QUARTER INCH INTO THE TWIN
CITIES. A CHECK ON RAP RUNS OVERNIGHT INDICATED A QPF PATTERN
DEVELOPING LIKE WHAT THE ECMWF AND CANADIAN ARE SHOWING. WE
BELIEVE PART OF REASON FOR THE DIFFERENCE IS THE CONVECTION
ONGOING TO OUR SOUTH THIS MORNING WITH STRONGER ACTIVITY PROGGED
FOR THIS AFTERNOON. THE NOSE OF THE 925-850MB MOISTURE TRANSPORT
WITH THE ECMWF JUST REACHES UP INTO NE IA THIS EVENING AND THEN
PASSES ACROSS SOUTHERN WI THIS EVENING. OUR INTERNAL MPX ARW-WRF
IS ALSO SHOWING THE QPF AXIS FURTHER SOUTH AS WELL. PTYPE THIS
AFTERNOON IS IN QUESTION WITH THE HRRR AND RAP SOUNDINGS
INDICATING SURFACE DEW POINTS RISING INTO THE LOWER AND MIDDLE 30S
ACROSS SOUTHERN MN WITH ALL RAIN INDICATED. THEY MAY BE TOO WARM
AS OUR MPX WRF SHOWS A CHANGE OVER TO SNOW ACROSS SOUTH CENTRAL MN
IN THE 21Z-24Z TIME FRAME ALONG WITH SOME FREEZING RAIN. HEADING
THROUGH THE EVENING...A DEEP MID LEVEL WAVE WILL PASS ACROSS IA/MO
WITH A DEFORMATION ZONE FROM NEAR KAEL TO KEAU. THIS IS THE ZONE
FOR 2 TO 4 INCHES OF SNOW ACCUMULATION TONIGHT WITH MUCH OF IT
OCCURRING BEFORE 06Z. SNOW AMOUNTS ARE LESS TO THE NORTHWEST WITH
AN INCH OR TWO IN THE TWIN CITIES WITH AROUND AN INCH AT ST.
CLOUD. BASED ON PTYPE ISSUES THIS AFTERNOON ALONG WITH THE SNOW
TONIGHT COUPLED WITH SOME MIXED SLEET AND FREEZING RAIN...WE
ISSUED A WINTER WEATHER ADVISORY FOR SOUTH CENTRAL MN BEGINNING
LATE THIS AFTERNOON WITH THE ADVISORY SPREADING NORTHEAST ACROSS
MUCH OF WEST CENTRAL WI FOR TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 410 AM CDT TUE MAR 24 2015
THE EXTENDED IS ACTUALLY LOOKING FAIRLY QUIET WITH THE MAIN
HAPPENINGS BEING THAT OF A PATTERN SHIFT...WITH A HIGHLY AMPLIFIED
PATTERN THIS WORK WEEK FLATTENING OUT AND BECOMING MORE ZONAL THIS
WEEKEND INTO NEXT WEEK. THE RESULT...TEMPS WILL REMAIN WELL BELOW
NORMAL THE REST OF THIS WORK WEEK...BUT BY THE WEEKEND...THEY WILL
REBOUND BACK TO NEAR OR EVEN A LITTLE ABOVE NORMAL.
THE LONG TERM WILL START WITH TONIGHTS TROUBLE MAKER PUSHING OUT OF
THE MPX AREA WEDNESDAY MORNING. GUIDANCE HAS CONTINUED TO PUSH WRAP
AROUND PRECIP WED/WED NIGHT FARTHER NORTH. IT IS LOOKING MORE AND
MORE LIKELY THAT THE MPX AREA WILL REMAIN DRY THIS PERIOD AS THE
WRAP AROUND MOISTURE STAYS CLOSER TO THE NRN SFC LOW THAT WILL BE
TRACKING ACROSS THE ARROWHEAD. HAVE CONTINUED THE TREND OF CUTTING
BACK POPS ON WEDNESDAY...WITH WED/WED NIGHT NOW BASICALLY DRY SOUTH
OF I-94. WHAT LOOKS MORE CERTAIN FOR WEDNESDAY ARE BREEZY
CONDITIONS. THE NAM SHOWS 3 HR PRESSURE RISES OF ABOUT 6 MB
FOLLOWING THE SFC LOW ACROSS THE ARROWHEAD...WITH 3 MB/3 HR RISES
ALL THE WAY DOWN INTO CENTRAL MN. IN ADDITION...BUFR SOUNDINGS UP AT
AXN SHOW MID CHANNEL MIX DOWN WINDS NEAR 35 KTS WITH TOP OF THE
CHANNEL WINDS AROUND 40 KTS. AS A RESULT...GAVE FORECAST WIND SPEEDS
A PRETTY GOOD BOOST FOR WEDNESDAY...WITH BORDERLINE WIND ADVY WINDS
NOW IN PLACE ACROSS WEST CENTRAL MN.
FOR THURSDAY AND FRIDAY...THE H5 FLOW BECOMES ALMOST NORTHERLY...
WHICH WILL ALLOW A 1035MB HIGH TO DROP DOWN OUT OF CANADA. WITH H85
TEMPS DOWN BETWEEN -6 TO -10C...WE WILL SEE HIGHS REMAIN IN THE 30S
BOTH DAYS...WITH SOME LOWS IN THE SINGLE DIGITS NOT OUT OF THE
QUESTION FRIDAY MORNING AS THE SFC HIGH SETTLES OVER MN AND OUR SNOW
COVER. THE ONE CHANGE SEEN WITH THE GUIDANCE THIS PERIOD IS THE
GEM/GFS/ECMWF ARE ALL SHOWING A QUICK HIT OF LIGHT PRECIP WORKING
ACROSS THE ERN DAKOTAS AND FAR WRN MN FRI/FRI NIGHT AS SHORT WAVE
ENERGY DROPPING DOWN IN THE NRLY FLOW WORKS WITH THE BAROCLINIC ZONE
ON THE BACKSIDE OF THE HIGH TO PRODUCE SOME LIGHT QPF. STILL HAVE A
DRY FORECAST OUT THAT DIRECTION...BUT IF THIS TREND CONTINUES...WE
MAY NEED TO START ADDING SOME SNOW CHANCES TO THE WEST FOR FRIDAY
EVENING.
THIS WEEKEND...AS THE UPPER FLOW BECOMES LESS AMPLIFIED...WE WILL
SEE A DEEP SFC LOW DROP OUT OF THE CANADIAN ARCTIC AND MOVE TOWARD
NW QUEBEC. WE WILL BE WELL WITHIN THE WARM SECTOR OF THIS SYSTEM...
THOUGH SAID WARM SECTOR IS STILL SCHEDULED TO COME THROUGH IN THE
DEAD OF NIGHT SATURDAY NIGHT. THE GEM/GFS BOTH HAVE A NICE SWATH OF
QPF WORKING DOWN WITH THE FRONT...BUT THE ECMWF CONTINUES TO BE DRY.
WITH THE GULF STILL CUT-OFF...THESE TYPES OF PATTERNS/FROPAS ARE
USUALLY DRY FOR US...SO DEFINITELY FAVOR THE DRIER ECMWF SOLUTION.
HOWEVER...WITH THE GEM/GFS IN THE BLENDING PROCEDURE USED...WE DO
HAVE POPS SPREAD ACROSS THE ENTIRE AREA SAT NIGHT...WITH THE HIGHEST
POPS OVER WI.
AFTER THIS WEEKEND...BOTH THE GFS/ECMWF SHOW THE REGION BEING DRY
UNTIL ANOTHER POWERFUL SPRING SYSTEM SHOWS UP TO WELCOME US TO APRIL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1003 CDT MON MAR 23 2015
CIGS HAVE NOT DECREASED SINCE SUNSET...BUT MVFR CIGS REMAIN IN
PLACE IN SOUTHERN MN AS LOW LEVEL MOISTURE REMAINS IN PLACE OVER
THE SNOWPACK. THE EASTERN EDGE OF THIS CLOUD DECK HAS BEEN SLOWLY
ERODING...AND VFR CONDITIONS NOW LOOK LIKELY OVERNIGHT AT EAU AND
POSSIBLE AT RNH. WHERE LOW CLOUDS REMAIN...CIGS WILL GRADUALLY
IMPROVE TUESDAY MORNING WITH VFR RETURNING...BUT AREAS THAT HAVE
SNOW COVER MAY BE SLOWER TO IMPROVE. WINDS WILL REMAIN
SOUTHEASTERLY AND INCREASE TO 10-15 KTS DURING THE AFTERNOON. SNOW
WILL DEVELOP OVER SW MN TUESDAY AFTERNOON AND MOVE INTO THE REST
OF OUR AREA DURING THE EVENING...RESULTING IN IFR CONDITIONS
THROUGH THE END OF THE PERIOD.
KMSP...MVFR CIGS WILL LIKELY CONTINUE OVERNIGHT AS LOW CLOUDS ARE
EXPECTED TO PERSIST OVER THE TERMINAL. CIGS SHOULD IMPROVE
TUESDAY MORNING...WITH VFR LIKELY RETURNING BY TUESDAY AFTERNOON.
PRECIPITATION IS EXPECTED TO RETURN AROUND 00Z TUESDAY
EVENING...POSSIBLY STARTING OUT AS A MIX OF RAIN AND SNOW BUT
QUICKLY CHANGING TO SNOW. IFR CONDITIONS ARE LIKELY TO RETURN
TUESDAY EVENING ONCE THE SNOW BEGINS.
/OUTLOOK FOR KMSP/
TUESDAY NIGHT...MVFR/IFR WITH -RA/-SN. WINDS SE 10-15 KTS.
WED...MVFR/IFR WITH -RA/-SN. WINDS W 15G25 KTS.
THU...MVFR AND -SN POSSIBLE EARLY. WINDS NNW 15G20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM CDT
WEDNESDAY FOR MNZ082>085-091>093.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 4 AM CDT
WEDNESDAY FOR MNZ077-078.
WI...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT
WEDNESDAY FOR WIZ024>028.
&&
$$
SHORT TERM...RAH
LONG TERM...MPG
AVIATION...ADL
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1225 AM CDT TUE MAR 24 2015
.UPDATE...
ISSUED AT 752 PM CDT MON MAR 23 2015
FOR NOW NOT PLANNING ANY MAJOR CHANGES TO THE FORECAST. BAND OF
WAA RAIN CURRENTLY MAKING ITS WAY INTO SOUTHWEST CWA. BASED ON
MODEL DATA AND LATEST SOUNDINGS ITS FAIR TO SAY I AM NOT SURE HOW
FAST/FAR THAT BAND WILL TRACK NORTHEAST. MAY NOT GET MUCH IN THE
WAY OF MEASURABLE PCPN IN THE NORTHEAST CWA UNTIL MORE ENERGY
COMES OUT ON TUESDAY. WILL CONTINUE TO WATCH THE ADVANCEMENT OF
RAIN THIS EVENING AND THEN DETERMINE ANY CHANGES THAT MIGHT NEED
TO BE MADE CONCERNING POPS..ETC. LOW TEMPERATURES LOOK MOSTLY ON
TARGET GIVEN OVERNIGHT CLOUDS AND LLJ.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 346 PM CDT MON MAR 23 2015
STRATUS DECK CONTINUES TO ERODE QUICKLY FROM SOUTHWEST TO
NORTHEAST ACROSS THE EASTERN CWA WITH TEMPS QUICKLY CLIMBING AS
THE SUN EMERGES. SNOWFALL FROM YESTERDAY WILL BE HISTORY FOR SOME
AREAS. ONCE AGAIN THE HRRR LOW-LEVEL CLOUD COVER PRODUCT PERFORMED
EXTREMELY WELL IN ERODING THE STRATUS DECK THIS AFTERNOON.
ATTENTION THEN TURNS TO THE STORM SYSTEM MOVING IN TONIGHT.
SHOWERS ARE ALREADY NOTED ACROSS SOUTHWEST SD AND APPROACHING THE
SOUTHWEST CWA. MODELS ARE COMING INTO BETTER AGREEMENT WITH A
DRIER SOLUTION OVER THE CWA. THAT SAID THOUGH...IT STILL APPEARS A
BAND OF WARM AIR ADVECTION RAINFALL WILL MOVE EASTWARD ACROSS THE
AREA LATE TONIGHT AND THROUGH THE DAY TUESDAY. ITS A QUESTION OF
JUST HOW FILLED IN AND INTENSE THIS BAND WILL BE. BACKED OFF ON
QPF A BIT THOUGH AS MODELS ARE RATHER LIGHT WITH ITS QPF OUTPUT.
OVERALL FORCING IS MODEST. COULD STILL BE DEALING WITH MIXED
PRECIP ACROSS THE EASTERN CWA LATE TONIGHT AND THROUGH THE DAY
TUESDAY. MODELS ALL SHOWING A DRY SLOT MOVING INTO THE WESTERN CWA
TUESDAY AFTERNOON...WITH BREEZY WEST TO NORTHWEST WINDS AND DRYING
CONDITIONS. RH VALUES WILL LIKELY FALL INTO THE 20S ACROSS THE
SOUTHWEST CWA ONCE AGAIN. TEMPS WILL WARM NICELY IN THE DRY
SLOT...ESPECIALLY OVER THE SOUTHWEST CWA AND MAY HAVE TO BUMP UP
HIGHS A FEW MORE DEGREES.
AS THE LOW PASSES TO THE EAST ON WEDNESDAY...STRONG NORTHWEST
WINDS DEVELOP. COULD BE CLOSE TO WIND ADVISORY LEVELS SO WILL HAVE
TO KEEP AN EYE ON THAT. WILL ALSO HAVE TO WATCH WRAP AROUND PRECIP
POTENTIAL ON THE BACK SIDE OF THE LOW. THERE ARE DISCREPANCIES IN
JUST HOW FAR SOUTH PRECIP WILL MAKE IT...WITH THE GFS THE FURTHEST
SOUTH THROUGH MUCH OF NORTHEAST SD AND WEST CENTRAL MN. THE EC
DOES NOT TAKE IT MUCH SOUTH OF THE ND/SD BORDER. GENERALLY WENT
WITH THE MORE RELIABLE EC AT THIS POINT. INTERESTING TO NOTE
THOUGH THAT THIS TIME AROUND THE GEM IS IN AGREEMENT WITH THE GFS.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 346 PM CDT MON MAR 23 2015
UPPER LEVEL PATTERN WILL TRANSITION FROM NORTHWEST FLOW TO A FLAT
RIDGE WITH SEVERAL WAVES PASSING THROUGH. THIS WILL RESULT IN
FLUCTUATING TEMPS THROUGH THE PERIOD. PATTERN DOES LOOK MOSTLY
DRY AS BEST UPPER ENERGY REMAINS NORTH OF THE STATE. TEMPS WILL
BE COOLEST ON THURSDAY...WITH A WARMING TREND INTO
SATURDAY...WHERE TEMPS WILL BE ABOVE NORMAL MOST LOCATIONS...ALONG
AND WEST OF THE MISSOURI RIVER. A STRONGER WAVE CRASHES THROUGH
THE RIDGE ON SATURDAY NIGHT BRINGING BREEZY CONDITIONS AND COOLER
TEMPS FOR SUNDAY...THEN A REBOUND OF TEMPS AGAIN FOR MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1223 AM CDT TUE MAR 24 2015
VFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE NIGHT AT ALL
TERMINALS. HOWEVER AN ADVANCING SYSTEM WILL BRING RAIN SHOWERS TO
THE REGION THROUGH TUESDAY. ACCOMPANYING THAT RAIN WILL BE LOWERED
CIGS...PROBABLY MOSTLY IN THE MVFR RANGE. LIGHT FOG WILL ALSO BE
POSSIBLE WITH THE LOWERED CIGS AND PCPN.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TDK
SHORT TERM...TMT
LONG TERM...SCARLETT
AVIATION...WISE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1104 AM CDT TUE MAR 24 2015
.SHORT TERM...
249 AM CDT
THROUGH TONIGHT...
IR IMAGERY EARLY THIS MORNING INDICATED THE STRATUS LAYER HAS
PUSHED WEST OF THE CHICAGO AREA...HOWEVER A FEW POCKETS OF STRATUS
HAVE BEEN REDEVELOPING AND SLIDING ACROSS FAR NORTHEAST IL. TEMPS
ARE GENERALLY REMAINED IN THE UPR 20S EARLY THIS MORNING...WITH A
FEW LOCATIONS RADIATING INTO THE LOW 20S. A NARROW CHANNEL OF
CIRRUS WAS ALREADY STREAMING NORTHEAST FROM THE DEVELOPING
SHORTWAVE CURRENTLY CENTERED OVER THE CENTRAL PLAINS. THE GRADIENT
WILL REMAIN LIGHT THROUGH DAYBREAK...HOWEVER THE WEAK DIFFLUENT
FLOW WILL QUICKLY DISSIPATE AND MIXING WILL STEADILY INCREASE BY
MID-MORNING. GUIDANCE INDICATES SPEEDS THROUGH THE CHANNEL ARND
20KT.
THE MOIST AXIS DOES APPEAR TO BE SLIGHTLY SLOWER TO ARRIVE ACROSS
NORTHEAST IL UNTIL AFT 21Z...SO HAVE NUDGED TIMING BACK AN HOUR OR
TWO. COULD SEE PRECIP PUSHING INTO THE FAR SOUTHWEST CWFA ARND 18-
20Z...HOWEVER WITH THE WEAK DIFFLUENT FLOW LINGERING FURTHER
NORTH...THIS MAY HELP TO HOLD-OFF PRECIP UNTIL CLOSER TO 00Z. WITH A
STEADY CONVEYOR OF SLIGHTLY WARMER AIR ADVECTING NORTH THIS
AFTN...TEMPS ARE EXPECTED TO WARM TO ARND 40. THE CONCERN IS THAT
WITH THE FRESH SNOWPACK THIS MAY HOLD TEMPS DOWN A DEGREE OR TWO.
TONIGHT...
AS ELUDED TOO ABOVE...PRECIP WILL BE STEADILY INCREASING IN
COVERAGE THIS EVENING. BUT THE MAIN CONCERN FOR TONIGHT WILL
REVOLVE AROUND CONVECTION AND POSSIBLY SOME STRONGER EMBEDDED
THUNDERSTORMS. MID- LVL SHEAR IS IMPRESSIVE THIS EVENING...WITH
VALUES NEARING 40-50KTS. GIVEN THE RATHER MOIST PROFILE AND CLOUDY
ENVIRONMENT...CAPE VALUES WILL REMAIN MINIMAL. 0-3KM BULK SHEAR IS
EQUALLY IMPRESSIVE WITH THIS DYNAMIC NEGATIVELY TILTED SHORTWAVE
TONIGHT. THE SPC HAS THE AREAS SOUTH OF PONTIAC TO FOWLER IN A
MARGINAL RISK FOR SEVERE STORMS TONIGHT.
DEW POINTS WILL BE STEADILY INCREASING THIS EVENING AS WELL...AS
WARM AIR CONTINUES TO ADVECT NORTH. BY LATE THIS EVENING DEW POINTS
WILL BE APPROACHING THE LOW/MID 30S...AND POSSIBLY NEAR 40 ACROSS
THE FAR SOUTH. THEN OVERNIGHT DEW POINTS WILL CONTINUE TO RISE INTO
THE MID/UPR 30S NORTH...AND LOW 40S SOUTH. THIS SHOULD AID IN EATING
INTO THE SNOWPACK RATHER QUICKLY...COUPLED WITH THE RAIN AS WELL.
PWAT VALUES WILL BE NEARING 1 INCH LATE TONIGHT...AS THE MOISTURE
TRANSPORT CONTINUES TO FEED NORTH ACROSS THE FORECAST AREA. CURRENT
TRACK OF THE SHORTWAVE IS TO LIFT NORTHEAST ACROSS PONTIAC TO GARY
BY 9Z...WHICH SHUD HELP PUSH CONVECTIVE COVERAGE EAST/NORTHEAST BY
DAYBREAK WED.
BEACHLER
&&
.LONG TERM...
350 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
THE MAIN STORY DURING THE LONGER TERM PERIOD WILL BE THE AMPLIFYING
UPPER LEVEL FLOW PATTERN ACROSS NORTH AMERICA. UPPER LEVEL RIDGING
IS FORECAST TO BUILD OVER THE WESTERN CONUS IN RESPONSE TO THE
PROGRESSION A SIGNIFICANT DISTURBANCE OVER THE NORTHERN
PACIFIC...AND THIS WILL ULTIMATELY DRIVE SIGNIFICANT HEIGHT FALLS
AND TROUGHING OVER THE THE EASTERN HALF OF THE CONUS. AS A
RESULT...EXPECT TO TRANSITION BACK TO A PERIOD OF MUCH BELOW AVERAGE
TEMPERATURES LATE THIS WEEK INTO THE FIRST HALF OF THE WEEKEND.
THE PERIOD WILL START OUT MILD ON WEDNESDAY FOLLOWING THE PASSAGE OF
THE TUESDAY NIGHT STORM SYSTEM. IT DOES APPEAR THAT CLOUD COVER
COULD LINGER DURING THE DAY ON WEDNESDAY...AND THIS COULD LIMIT THE
AMOUNT OF WARMING WE EXPERIENCE DURING THE DAY. HOWEVER...WITH THE
COLDER AIRMASS NOT ARRIVING ACROSS THE AREA UNTIL LATER WEDNESDAY
NIGHT TEMPERATURES SHOULD BE ABLE TO CLIMB TO...AT LEAST...NEAR 50
DEGREES. AREAS SOUTH OF INTERSTATE 80 STAND THE BEST CHANCES TO
CLIMB WELL INTO THE 50S.
AS A COLD FRONT BEGINS TO SHIFT ACROSS NORTHERN ILLINOIS WEDNESDAY
NIGHT A WEAK SURFACE WAVE OF LOW PRESSURE IS EXPECTED TO DEVELOP
OVER THE SOUTHERN PLAINS...BEFORE QUICKLY SHIFTING NORTHEASTWARD
ALONG THE FRONT INTO THURSDAY MORNING. INCREASING FGEN ALONG THIS
FRONTAL WAVE SHOULD RESULT IN PRECIPITATION DEVELOPMENT WEDNESDAY
NIGHT...PRIMARILY ACROSS MY EAST CENTRAL ILLINOIS AND NORTHWESTERN
INDIANA COUNTIES. THIS ACTIVITY WILL SHIFT TO THE SOUTH AND EAST OF
MY AREA BY EARLY THURSDAY MORNING AS THE COLD FRONT CONTINUES TO
SHIFT SOUTHEASTWARD. DRY BUT COOLER WEATHER IN THE LOW TO 40S IS
EXPECTED FOR THE DAY THURSDAY.
ANOTHER STRONGER PUSH OF COLD AIR WILL ARRIVE OVER THE AREA BY
THURSDAY NIGHT INTO FRIDAY AS YET ANOTHER COLD FRONT SHIFTS OVER THE
AREA. STEEPENING LOW LEVEL LAPSE RATES OVER LAKE MICHIGAN WITH THIS
COLD AIR MASS COULD EVEN RESULT IN SOME LAKE EFFECT SNOW SHOWERS
ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA INTO FRIDAY
MORNING...AND THIS ACTIVITY LOOKS AS THOUGH IT COULD BE COMPLIMENTED
BY ANOTHER UPPER LEVEL PV ANOMALY DIGGING INTO THE BASE OF THE UPPER
LEVEL TROUGH OVER THE AREA. IF THIS SCENARIO PANS OUT AS CURRENTLY
FORECAST...THERE COULD BE SOME MINOR SNOW ACCUMULATIONS ACROSS
PORTIONS OF THE AREA WITH THIS ACTIVITY INTO FRIDAY.
WITH THE HEART OF THE COLD AIR MASS EXPECTED TO BE OVERHEAD ON
FRIDAY...IT LOOKS TO BE THE COLDEST DAY. HIGH TEMPERATURES ARE
CURRENTLY ONLY FORECAST TO GET INTO THE LOWER TO MID 30S...WHICH IS
A GOOD 15 TO 20 DEGREES BELOW AVERAGE. SURFACE HIGH PRESSURE SHOULD
BECOME CENTERED OVER OR NEAR THE AREA BY LATE FRIDAY NIGHT...SO THIS
SHOULD ALLOW TEMPERATURES FRIDAY NIGHT TO DROP INTO THE TEENS
INTO SATURDAY MORNING OUTSIDE OF CHICAGO.
AFTER ANOTHER WELL BELOW AVERAGE DAY ON SATURDAY...THINGS LOOKS TO
WARM BACK UP BY SUNDAY SURFACE RIDGE SHIFTS OVER THE SOUTHEASTERN
CONUS. IT APPEARS THAT SUNDAY COULD END UP NOT ONLY BEING A WARMER
DAY...WITH HIGHS POTENTIALLY WARMING BACK UP NEAR OR JUST ABOVE
AVERAGE...BUT ALSO A VERY BREEZY DAY. FORECAST GUIDANCE SUGGESTS
THAT A POTENT CLIPPER SYSTEM WILL TRACK EAST-SOUTHEASTWARD OVER
SOUTHERN ONTARIO...WHICH COULD SET UP A SURFACE GRADIENT SUPPORTIVE
OF SOME STRONG SOUTHWESTERLY WINDS. IN ADDITION...THE INCREASING WARM
AIR ADVECTON REGIME OVER THE AREA COULD ALSO RESULT IN THE
DEVELOPMENT OF SOME LIGHT RAIN SHOWERS DURING THE DAY.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* EAST WINDS AT 10-15 KT WITH GUSTS UP TO 20 KT LATE THIS AFTN
THRU THIS EVE.
* SHOWERS ARRIVE AROUND 00Z WITH STEADY RAINFALL AND MVFR VSBY
ARRIVING LATE THIS EVENING.
* IFR OR LOWER CIGS EXPECTED WITH STEADY RAIN THIS EVENING AND
OVERNIGHT.
* LLWS THIS EVE.
* GUSTY SOUTHWEST TO WEST WINDS TOMORROW.
JEE
//DISCUSSION...UPDATED 12Z...
STRATUS CLOUDS HAVE PUSHED WELL TO THE WEST/SOUTHWEST OF THE TAF
SITES EARLY THIS MORNING. IR IMAGERY INDICATES A LAYER OF MID/HIGH
DECK CLOUDS BEGINNING TO STREAM NORTHEAST ACROSS NORTHERN
IL/NORTHWEST IN THIS MORNING. AS THE LOW PRESSURE OVER THE CENTRAL
PLAINS NUDGES NORTHEAST TOWARDS NORTHERN IL AIRFIELDS...WINDS WILL
BEGIN TO INCREASE AND TURN SOUTHEASTERLY LATER THIS MORNING. GUSTS
SHUD START TO INCREASE IN FREQUENCY ARND 20Z...THEN CONTINUE TO
INCREASE IN SPEEDS BY THIS AFTN NEARING 20-23KT. RAIN IS EXPECTED
TO DEVELOP LATE THIS AFTN AND ARRIVE ACROSS THE TAF SITES LATE
AFTN/EARLY EVE...WITH COVERAGE INCREASING LATER TONIGHT. EXPECT
THE MOIST ATMOSPHERE TO ALLOW CIGS TO DROP TO IFR/LOW-END MVFR
LATER TONIGHT THROUGH THE OVERNIGHT HOURS.
IN ADDITION TO THE RAIN WILL BE THE POTENTIAL FOR EMBEDDED
THUNDERSTORMS...HOWEVER THE BEST CHANCE FOR THUNDER APPEARS TO BE
SOUTH OF THE TAF SITES. SO HAVE OPTED TO HOLD OFF ON INCLUDING
THUNDER WITHIN THE CURRENT TAF. LATER TONIGHT THE WINDS AT 2KFT
AGL ARE FORECAST TO APPROACH 50KT AS A LOW LEVEL JET ARRIVES.
EXPECT THE SFC TO BE DECOUPLED FROM THE WINDS ALOFT...SO WILL
CARRY LLWS WITHIN THE TAF. AS THE LOW LIFTS OVERHEAD EARLY WED
MORNING WINDS WILL DIMINISH...THEN INCREASE ARND DAYBREAK ALONG
WITH VEERING WEST. AS THE LOW PASSES OVERHEAD PRECIP WILL COME TO
AN END...HOWEVER MVFR TO IFR CIGS ARE EXPECTED TO PERSIST UNTIL
LATE WED MORNING.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN RAIN...MEDIUM-HIGH CONFIDENCE IN TIMING.
* MEDIUM-LOW CONFIDENCE IN OCCURRENCE AND COVERAGE OF TS.
* HIGH CONFIDENCE IN LOWER CIGS...MEDIUM CONFIDENCE IN TIMING AND
HOW LOW THEY WILL BE.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WEST TO NORTHWEST WINDS. MAINLY VFR CONDS.
THURSDAY...CHANCE OF SNOW SHOWERS MAINLY IN THE EVENING. MVFR
POSSIBLE.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW EARLY. OTHERWISE PRIMARILY
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE OF RAIN. PATCHY MVFR POSSIBLE.
MONDAY...VFR.
BEACHLER
&&
.MARINE...
409 AM CDT
WINDS WILL BEGIN TO INCREASE OUT OF THE SOUTHEAST OVER SOUTHERN LAKE
MICHIGAN THIS EVENING AS AN AREA OF LOW PRESSURE MOVES TOWARDS
NORTHERN ILLINOIS. IT NOW APPEARS THAT THE SURFACE LOW WILL TAKE A
TRACK RIGHT ACROSS SOUTHERN LAKE MICHIGAN LATE TONIGHT INTO EARLY
WEDNESDAY MORNING. THEREFORE...AS THE LOW MOVES OVER THE
LAKE...WINDS WILL LIKELY BECOME LIGHT AND VARIABLE FOR SHORT
PERIOD OVER FAR SOUTHERN LAKE MICHIGAN. WEST SOUTHWESTERLY WINDS
WILL ENSURE AS THE LOW SHIFTS OVER LOWER MICHIGAN WEDNESDAY
MORNING. WIND SPEEDS COULD APPROACH 25 TO 30 KT DURING THE
MORNING...BUT WIND SPEEDS SHOULD BE ON A DIMINISHING TREND THROUGH
THE DAY.
A COLD FRONT WILL SHIFT DOWN THE LAKE WEDNESDAY NIGHT...RESULTING IN
A NORTHERLY WIND SHIFT FOR THURSDAY. WINDS SPEEDS SHOULD ALSO
INCREASE UP TO 25 TO 30 KT BY THURSDAY EVENING AS THE SURFACE
GRADIENT TIGHTENS AHEAD OF AN AREA OF HIGH PRESSURE SHIFTING
SOUTHEASTWARD OVER THE UPPER MIDWEST. THIS SURFACE HIGH IS EXPECTED
TO SHIFT SOUTHEASTWARD OVER NORTHEASTERN ILLINOIS SATURDAY
MORNING...THEN SHIFT OVER THE SOUTHEASTERN CONUS BY SUNDAY. IT
APPEARS THAT ANOTHER SIGNIFICANT SOUTHERLY WIND EVENT COULD SET UP
FOR SUNDAY AS A POTENTIAL STORM SYSTEM TRACKS ACROSS SOUTHERN
ONTARIO.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...7 PM TUESDAY TO 4 PM WEDNESDAY.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1103 AM CDT Tue Mar 24 2015
.UPDATE...
ISSUED AT 1038 AM CDT TUE MAR 24 2015
High pressure sliding east as another low develops over the Plains
and moves into the Midwest later this evening. For now, a frontal
boundary not making much progress northward up into the region.
Between the slower approach of the front and the persistent cloud
cover, have pulled down todays highs. Would like to bring them
down further, but sat imagery starting to show some holes here and
there...and any clearing in the afternoon hours may allow for some
warming...but the highs for today will definitely wait until the
end of the day...with temps steady or climbing through the
overnight hours.
&&
.SHORT TERM...(Today)
ISSUED AT 329 AM CDT TUE MAR 24 2015
A band of mid-level warm frontogenesis will advance into central IL
from the west this morning, causing rain showers to eventually
develop through the dry low level airmass. The leading edge of the
rain band will likely encounter areas with surface temps at or just
below freezing, but not sure how far south will freezing rain
affect. 08z obs show only Jacksonville and Lawrenceville above
freezing, while the remainder of our C and SE IL obs at or below
freezing. Will need to include a mention of freezing rain a bit
farther south this morning as a result. Road surface temps on IDOT
sites showing road temps ranging from 34 to as low as 31F. We could
see some slippery road conditions develop with this initial rain
falling on dry pavement. Air temperatures should rise above freezing
across the board by 15z/10am, so any icing would melt quickly.
However, any ice on initially dry roads can be very slippery.
Will follow the HRRR depiction of rain advancing eastward in a band
that matches the current radar trends rather closely. Likely and
categorical PoPs this morning will be confined to the western
counties where low level saturation will occur the soonest.
The band of warm F-gen will gradually shift north this afternoon,
giving the precip a northward push as well. Have kept likely PoPs
across the northern half of our area through the afternoon.
Instability params support elevated thunderstorms today, generally
in the southwest half of our forecast area.
High temps today will be held in check by the cool east-northeast
flow that will persist through the day. Most areas will see the
mid-upper 40s this afternoon.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 329 AM CDT TUE MAR 24 2015
Deepening surface low pressure currently at 1006 mb over the OK
panhandle to eject ne into the IL river valley over central IL by
06Z/1 am tonight and then to southern part of Lake MI by 12Z/7 am
Wed and swing a cold front through central and eastern IL overnight.
Showers likely ahead of this front along with chances of
thunderstorms. SPC has marginal risk over much of central IL
(excluding Knox, Stark and Marshall counties) with slight risk of
severe storms this evening across central and sw MO from St Louis
southwest. Lows tonight range from upper 30s to near 40F over IL
river valley to upper 40s and lower 50s in southeast IL.
Central IL to be in between weather systems during the day Wed as low
pressure passes ne of the Great Lakes and another surface low
pressure organizes over the southern plains. Isolated showers and
thunderstorms to be possible later Wed afternoon south of I-72.
Milder highs Wed mostly in the 60s, ranging from around 60F from
Peoria north to upper 60s and lower 70s in southeast IL. 1007 mb low
pressure to track ne into far southern IL by 06Z/1 AM Wed night and
up the Ohio river to near the OH/KY border by dawn Thu. Models have
trended further south with this low pressure track, and SPC has
shifted slight risk of severe storms Wed night south of our CWA with
marginal risk into southeast counties along and south of I-70. Heavy
rains of 1-1.5 inches possible south of I-70 Wed night while rain
chances taper off to 20-30% nw of the IL river. Lows Wed night range
from mid 30s over IL river valley to 40-45F in southeast IL from I-70
southeast.
Lingered a chance of rain showers in southeast IL Thu morning then
low pressure moves into south-central PA by midday Thu and far enough
way to end rain chances Thu afternoon. Much cooler highs Thu in the
mid to upper 40s central IL and near 50F southeast IL. Even colder
Friday with highs in the upper 30s and lower 40s, coolest from I-74
ne. Models have been consistent in digging strong upper level trof
into the eastern states Thu/Fri bringing in the very cool
temperatures. 1030 mb Canadian high pressure settles into the Great
Lakes region Fri night and Sat with clouds and winds decreasing and
continued cold temps. Lows Fri night in the low to mid 20s. Highs
Sat in the low to mid 40s.
A cutoff upper level low passes north of the Great Lakes Sunday
keeping best chances of precipitation north of central IL, though
did carry small chances of light rain showers Sunday. Milder highs
Sunday and Monday in the mid to upper 50s with west central IL
around 60F.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 638 AM CDT TUE MAR 24 2015
Initial concern will be light freezing rain at SPI and DEC through
14z. Surface temperatures will be right around the freezing mark
through this time frame so some light icing is not out of the
question before temperatures edge into the middle 30s by mid to
late morning. Further north and east, the latest short term models
suggest the precip may struggle to shift north before 15z so will
hold back the precip threat up at PIA and BMI until after 15z. By
then, it appears the precip would be mostly rain with the
possibility for some isolated convection over parts of west
central and central IL during the morning. For now, will hold off
mentioning any -tsra during the morning, with the better threat for
isolated thunderstorms coming along this evening, as low pressure
passes across IL. MVFR and local IFR cigs will prevail thru most
of this forecast period with periods of rain through this
evening. Rain should come to an end from SW to NE as the low pulls
away into Indiana after midnight.
Surface winds will remain out of the east today, with a gradual
turn into the southeast and then south this evening as the surface
low approaches our area. Wind speeds will range from 12 to 17 kts
with gusts around 22 kts at times this afternoon and early this
evening.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...Shimon
LONG TERM...07
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
650 AM CDT TUE MAR 24 2015
.SHORT TERM...
249 AM CDT
THROUGH TONIGHT...
IR IMAGERY EARLY THIS MORNING INDICATED THE STRATUS LAYER HAS
PUSHED WEST OF THE CHICAGO AREA...HOWEVER A FEW POCKETS OF STRATUS
HAVE BEEN REDEVELOPING AND SLIDING ACROSS FAR NORTHEAST IL. TEMPS
ARE GENERALLY REMAINED IN THE UPR 20S EARLY THIS MORNING...WITH A
FEW LOCATIONS RADIATING INTO THE LOW 20S. A NARROW CHANNEL OF
CIRRUS WAS ALREADY STREAMING NORTHEAST FROM THE DEVELOPING
SHORTWAVE CURRENTLY CENTERED OVER THE CENTRAL PLAINS. THE GRADIENT
WILL REMAIN LIGHT THROUGH DAYBREAK...HOWEVER THE WEAK DIFFLUENT
FLOW WILL QUICKLY DISSIPATE AND MIXING WILL STEADILY INCREASE BY
MID-MORNING. GUIDANCE INDICATES SPEEDS THROUGH THE CHANNEL ARND
20KT.
THE MOIST AXIS DOES APPEAR TO BE SLIGHTLY SLOWER TO ARRIVE ACROSS
NORTHEAST IL UNTIL AFT 21Z...SO HAVE NUDGED TIMING BACK AN HOUR OR
TWO. COULD SEE PRECIP PUSHING INTO THE FAR SOUTHWEST CWFA ARND 18-
20Z...HOWEVER WITH THE WEAK DIFFLUENT FLOW LINGERING FURTHER
NORTH...THIS MAY HELP TO HOLD-OFF PRECIP UNTIL CLOSER TO 00Z. WITH A
STEADY CONVEYOR OF SLIGHTLY WARMER AIR ADVECTING NORTH THIS
AFTN...TEMPS ARE EXPECTED TO WARM TO ARND 40. THE CONCERN IS THAT
WITH THE FRESH SNOWPACK THIS MAY HOLD TEMPS DOWN A DEGREE OR TWO.
TONIGHT...
AS ELUDED TOO ABOVE...PRECIP WILL BE STEADILY INCREASING IN
COVERAGE THIS EVENING. BUT THE MAIN CONCERN FOR TONIGHT WILL
REVOLVE AROUND CONVECTION AND POSSIBLY SOME STRONGER EMBEDDED
THUNDERSTORMS. MID- LVL SHEAR IS IMPRESSIVE THIS EVENING...WITH
VALUES NEARING 40-50KTS. GIVEN THE RATHER MOIST PROFILE AND CLOUDY
ENVIRONMENT...CAPE VALUES WILL REMAIN MINIMAL. 0-3KM BULK SHEAR IS
EQUALLY IMPRESSIVE WITH THIS DYNAMIC NEGATIVELY TILTED SHORTWAVE
TONIGHT. THE SPC HAS THE AREAS SOUTH OF PONTIAC TO FOWLER IN A
MARGINAL RISK FOR SEVERE STORMS TONIGHT.
DEW POINTS WILL BE STEADILY INCREASING THIS EVENING AS WELL...AS
WARM AIR CONTINUES TO ADVECT NORTH. BY LATE THIS EVENING DEW POINTS
WILL BE APPROACHING THE LOW/MID 30S...AND POSSIBLY NEAR 40 ACROSS
THE FAR SOUTH. THEN OVERNIGHT DEW POINTS WILL CONTINUE TO RISE INTO
THE MID/UPR 30S NORTH...AND LOW 40S SOUTH. THIS SHOULD AID IN EATING
INTO THE SNOWPACK RATHER QUICKLY...COUPLED WITH THE RAIN AS WELL.
PWAT VALUES WILL BE NEARING 1 INCH LATE TONIGHT...AS THE MOISTURE
TRANSPORT CONTINUES TO FEED NORTH ACROSS THE FORECAST AREA. CURRENT
TRACK OF THE SHORTWAVE IS TO LIFT NORTHEAST ACROSS PONTIAC TO GARY
BY 9Z...WHICH SHUD HELP PUSH CONVECTIVE COVERAGE EAST/NORTHEAST BY
DAYBREAK WED.
BEACHLER
&&
.LONG TERM...
350 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
THE MAIN STORY DURING THE LONGER TERM PERIOD WILL BE THE AMPLIFYING
UPPER LEVEL FLOW PATTERN ACROSS NORTH AMERICA. UPPER LEVEL RIDGING
IS FORECAST TO BUILD OVER THE WESTERN CONUS IN RESPONSE TO THE
PROGRESSION A SIGNIFICANT DISTURBANCE OVER THE NORTHERN
PACIFIC...AND THIS WILL ULTIMATELY DRIVE SIGNIFICANT HEIGHT FALLS
AND TROUGHING OVER THE THE EASTERN HALF OF THE CONUS. AS A
RESULT...EXPECT TO TRANSITION BACK TO A PERIOD OF MUCH BELOW AVERAGE
TEMPERATURES LATE THIS WEEK INTO THE FIRST HALF OF THE WEEKEND.
THE PERIOD WILL START OUT MILD ON WEDNESDAY FOLLOWING THE PASSAGE OF
THE TUESDAY NIGHT STORM SYSTEM. IT DOES APPEAR THAT CLOUD COVER
COULD LINGER DURING THE DAY ON WEDNESDAY...AND THIS COULD LIMIT THE
AMOUNT OF WARMING WE EXPERIENCE DURING THE DAY. HOWEVER...WITH THE
COLDER AIRMASS NOT ARRIVING ACROSS THE AREA UNTIL LATER WEDNESDAY
NIGHT TEMPERATURES SHOULD BE ABLE TO CLIMB TO...AT LEAST...NEAR 50
DEGREES. AREAS SOUTH OF INTERSTATE 80 STAND THE BEST CHANCES TO
CLIMB WELL INTO THE 50S.
AS A COLD FRONT BEGINS TO SHIFT ACROSS NORTHERN ILLINOIS WEDNESDAY
NIGHT A WEAK SURFACE WAVE OF LOW PRESSURE IS EXPECTED TO DEVELOP
OVER THE SOUTHERN PLAINS...BEFORE QUICKLY SHIFTING NORTHEASTWARD
ALONG THE FRONT INTO THURSDAY MORNING. INCREASING FGEN ALONG THIS
FRONTAL WAVE SHOULD RESULT IN PRECIPITATION DEVELOPMENT WEDNESDAY
NIGHT...PRIMARILY ACROSS MY EAST CENTRAL ILLINOIS AND NORTHWESTERN
INDIANA COUNTIES. THIS ACTIVITY WILL SHIFT TO THE SOUTH AND EAST OF
MY AREA BY EARLY THURSDAY MORNING AS THE COLD FRONT CONTINUES TO
SHIFT SOUTHEASTWARD. DRY BUT COOLER WEATHER IN THE LOW TO 40S IS
EXPECTED FOR THE DAY THURSDAY.
ANOTHER STRONGER PUSH OF COLD AIR WILL ARRIVE OVER THE AREA BY
THURSDAY NIGHT INTO FRIDAY AS YET ANOTHER COLD FRONT SHIFTS OVER THE
AREA. STEEPENING LOW LEVEL LAPSE RATES OVER LAKE MICHIGAN WITH THIS
COLD AIR MASS COULD EVEN RESULT IN SOME LAKE EFFECT SNOW SHOWERS
ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA INTO FRIDAY
MORNING...AND THIS ACTIVITY LOOKS AS THOUGH IT COULD BE COMPLIMENTED
BY ANOTHER UPPER LEVEL PV ANOMALY DIGGING INTO THE BASE OF THE UPPER
LEVEL TROUGH OVER THE AREA. IF THIS SCENARIO PANS OUT AS CURRENTLY
FORECAST...THERE COULD BE SOME MINOR SNOW ACCUMULATIONS ACROSS
PORTIONS OF THE AREA WITH THIS ACTIVITY INTO FRIDAY.
WITH THE HEART OF THE COLD AIR MASS EXPECTED TO BE OVERHEAD ON
FRIDAY...IT LOOKS TO BE THE COLDEST DAY. HIGH TEMPERATURES ARE
CURRENTLY ONLY FORECAST TO GET INTO THE LOWER TO MID 30S...WHICH IS
A GOOD 15 TO 20 DEGREES BELOW AVERAGE. SURFACE HIGH PRESSURE SHOULD
BECOME CENTERED OVER OR NEAR THE AREA BY LATE FRIDAY NIGHT...SO THIS
SHOULD ALLOW TEMPERATURES FRIDAY NIGHT TO DROP INTO THE TEENS
INTO SATURDAY MORNING OUTSIDE OF CHICAGO.
AFTER ANOTHER WELL BELOW AVERAGE DAY ON SATURDAY...THINGS LOOKS TO
WARM BACK UP BY SUNDAY SURFACE RIDGE SHIFTS OVER THE SOUTHEASTERN
CONUS. IT APPEARS THAT SUNDAY COULD END UP NOT ONLY BEING A WARMER
DAY...WITH HIGHS POTENTIALLY WARMING BACK UP NEAR OR JUST ABOVE
AVERAGE...BUT ALSO A VERY BREEZY DAY. FORECAST GUIDANCE SUGGESTS
THAT A POTENT CLIPPER SYSTEM WILL TRACK EAST-SOUTHEASTWARD OVER
SOUTHERN ONTARIO...WHICH COULD SET UP A SURFACE GRADIENT SUPPORTIVE
OF SOME STRONG SOUTHWESTERLY WINDS. IN ADDITION...THE INCREASING WARM
AIR ADVECTON REGIME OVER THE AREA COULD ALSO RESULT IN THE
DEVELOPMENT OF SOME LIGHT RAIN SHOWERS DURING THE DAY.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* EAST WINDS PERSIST BETWEEN 5-8KT...INCREASING LATE MORNING TO
10-12KT. WINDS TURN SOUTHEAST AND INCREASE MID-MORNING...SPEEDS
BETWEEN 12-15KT WITH GUSTS UP TO 20KT.
* RAIN DEVELOPS LATE AFTN/EARLY EVE...WITH STEADIER RAIN AFT 00Z
WED. EMBEDDED THUNDER POSSIBLE AFT 00Z WED. IFR CIGS DEVELOP.
* LLWS POSSIBLE LATE TONIGHT...AOA 2KFT AGL SPEEDS INCREASE TO
50KT FROM SOUTHEAST AFT 2Z WED.
* LULL IN WINDS PRIOR TO DAYBREAK WED...THEN VEERING WEST AND
INCREASING JUST AFTER DAYBREAK WED.
BEACHLER
//DISCUSSION...UPDATED 12Z...
STRATUS CLOUDS HAVE PUSHED WELL TO THE WEST/SOUTHWEST OF THE TAF
SITES EARLY THIS MORNING. IR IMAGERY INDICATES A LAYER OF MID/HIGH
DECK CLOUDS BEGINNING TO STREAM NORTHEAST ACROSS NORTHERN
IL/NORTHWEST IN THIS MORNING. AS THE LOW PRESSURE OVER THE CENTRAL
PLAINS NUDGES NORTHEAST TOWARDS NORTHERN IL AIRFIELDS...WINDS WILL
BEGIN TO INCREASE AND TURN SOUTHEASTERLY LATER THIS MORNING. GUSTS
SHUD START TO INCREASE IN FREQUENCY ARND 20Z...THEN CONTINUE TO
INCREASE IN SPEEDS BY THIS AFTN NEARING 20-23KT. RAIN IS EXPECTED
TO DEVELOP LATE THIS AFTN AND ARRIVE ACROSS THE TAF SITES LATE
AFTN/EARLY EVE...WITH COVERAGE INCREASING LATER TONIGHT. EXPECT
THE MOIST ATMOSPHERE TO ALLOW CIGS TO DROP TO IFR/LOW-END MVFR
LATER TONIGHT THROUGH THE OVERNIGHT HOURS.
IN ADDITION TO THE RAIN WILL BE THE POTENTIAL FOR EMBEDDED
THUNDERSTORMS...HOWEVER THE BEST CHANCE FOR THUNDER APPEARS TO BE
SOUTH OF THE TAF SITES. SO HAVE OPTED TO HOLD OFF ON INCLUDING
THUNDER WITHIN THE CURRENT TAF. LATER TONIGHT THE WINDS AT 2KFT
AGL ARE FORECAST TO APPROACH 50KT AS A LOW LEVEL JET ARRIVES.
EXPECT THE SFC TO BE DECOUPLED FROM THE WINDS ALOFT...SO WILL
CARRY LLWS WITHIN THE TAF. AS THE LOW LIFTS OVERHEAD EARLY WED
MORNING WINDS WILL DIMINISH...THEN INCREASE ARND DAYBREAK ALONG
WITH VEERING WEST. AS THE LOW PASSES OVERHEAD PRECIP WILL COME TO
AN END...HOWEVER MVFR TO IFR CIGS ARE EXPECTED TO PERSIST UNTIL
LATE WED MORNING.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN CIGS THRU 20Z...MEDIUM CONFIDENCE IN TIMING
OF MVFR/IFR CIGS AFT 00Z WED.
* HIGH CONFIDENCE IN RAIN DEVELOPING AFT 22Z...LOW CONFIDENCE IN
PRECISE TIMING. MEDIUM/LOW IN THUNDER TIMING AND COVERAGE
OVERNIGHT INTO EARLY WED MORNING.
* HIGH CONFIDECE IN LLWS DEVELOPING AND MEDIUM CONFIDENCE IN
SPEEDS OF LLWS.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WEST TO NORTHWEST WINDS. MAINLY VFR CONDS.
THURSDAY...CHANCE OF SNOW SHOWERS MAINLY IN THE EVENING. MVFR
POSSIBLE.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW EARLY. OTHERWISE PRIMARILY
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE OF RAIN. PATCHY MVFR POSSIBLE.
MONDAY...VFR.
BEACHLER
&&
.MARINE...
409 AM CDT
WINDS WILL BEGIN TO INCREASE OUT OF THE SOUTHEAST OVER SOUTHERN LAKE
MICHIGAN THIS EVENING AS AN AREA OF LOW PRESSURE MOVES TOWARDS
NORTHERN ILLINOIS. IT NOW APPEARS THAT THE SURFACE LOW WILL TAKE A
TRACK RIGHT ACROSS SOUTHERN LAKE MICHIGAN LATE TONIGHT INTO EARLY
WEDNESDAY MORNING. THEREFORE...AS THE LOW MOVES OVER THE
LAKE...WINDS WILL LIKELY BECOME LIGHT AND VARIABLE FOR SHORT
PERIOD OVER FAR SOUTHERN LAKE MICHIGAN. WEST SOUTHWESTERLY WINDS
WILL ENSURE AS THE LOW SHIFTS OVER LOWER MICHIGAN WEDNESDAY
MORNING. WIND SPEEDS COULD APPROACH 25 TO 30 KT DURING THE
MORNING...BUT WIND SPEEDS SHOULD BE ON A DIMINISHING TREND THROUGH
THE DAY.
A COLD FRONT WILL SHIFT DOWN THE LAKE WEDNESDAY NIGHT...RESULTING IN
A NORTHERLY WIND SHIFT FOR THURSDAY. WINDS SPEEDS SHOULD ALSO
INCREASE UP TO 25 TO 30 KT BY THURSDAY EVENING AS THE SURFACE
GRADIENT TIGHTENS AHEAD OF AN AREA OF HIGH PRESSURE SHIFTING
SOUTHEASTWARD OVER THE UPPER MIDWEST. THIS SURFACE HIGH IS EXPECTED
TO SHIFT SOUTHEASTWARD OVER NORTHEASTERN ILLINOIS SATURDAY
MORNING...THEN SHIFT OVER THE SOUTHEASTERN CONUS BY SUNDAY. IT
APPEARS THAT ANOTHER SIGNIFICANT SOUTHERLY WIND EVENT COULD SET UP
FOR SUNDAY AS A POTENTIAL STORM SYSTEM TRACKS ACROSS SOUTHERN
ONTARIO.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...7 PM TUESDAY TO 4 PM WEDNESDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
638 AM CDT Tue Mar 24 2015
.SHORT TERM...(Today)
ISSUED AT 329 AM CDT TUE MAR 24 2015
A band of mid-level warm frontogenesis will advance into central IL
from the west this morning, causing rain showers to eventually
develop through the dry low level airmass. The leading edge of the
rain band will likely encounter areas with surface temps at or just
below freezing, but not sure how far south will freezing rain
affect. 08z obs show only Jacksonville and Lawrenceville above
freezing, while the remainder of our C and SE IL obs at or below
freezing. Will need to include a mention of freezing rain a bit
farther south this morning as a result. Road surface temps on IDOT
sites showing road temps ranging from 34 to as low as 31F. We could
see some slippery road conditions develop with this initial rain
falling on dry pavement. Air temperatures should rise above freezing
across the board by 15z/10am, so any icing would melt quickly.
However, any ice on initially dry roads can be very slippery.
Will follow the HRRR depiction of rain advancing eastward in a band
that matches the current radar trends rather closely. Likely and
categorical PoPs this morning will be confined to the western
counties where low level saturation will occur the soonest.
The band of warm F-gen will gradually shift north this afternoon,
giving the precip a northward push as well. Have kept likely PoPs
across the northern half of our area through the afternoon.
Instability params support elevated thunderstorms today, generally
in the southwest half of our forecast area.
High temps today will be held in check by the cool east-northeast
flow that will persist through the day. Most areas will see the
mid-upper 40s this afternoon.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 329 AM CDT TUE MAR 24 2015
Deepening surface low pressure currently at 1006 mb over the OK
panhandle to eject ne into the IL river valley over central IL by
06Z/1 am tonight and then to southern part of Lake MI by 12Z/7 am
Wed and swing a cold front through central and eastern IL overnight.
Showers likely ahead of this front along with chances of
thunderstorms. SPC has marginal risk over much of central IL
(excluding Knox, Stark and Marshall counties) with slight risk of
severe storms this evening across central and sw MO from St Louis
southwest. Lows tonight range from upper 30s to near 40F over IL
river valley to upper 40s and lower 50s in southeast IL.
Central IL to be in between weather systems during the day Wed as low
pressure passes ne of the Great Lakes and another surface low
pressure organizes over the southern plains. Isolated showers and
thunderstorms to be possible later Wed afternoon south of I-72.
Milder highs Wed mostly in the 60s, ranging from around 60F from
Peoria north to upper 60s and lower 70s in southeast IL. 1007 mb low
pressure to track ne into far southern IL by 06Z/1 AM Wed night and
up the Ohio river to near the OH/KY border by dawn Thu. Models have
trended further south with this low pressure track, and SPC has
shifted slight risk of severe storms Wed night south of our CWA with
marginal risk into southeast counties along and south of I-70. Heavy
rains of 1-1.5 inches possible south of I-70 Wed night while rain
chances taper off to 20-30% nw of the IL river. Lows Wed night range
from mid 30s over IL river valley to 40-45F in southeast IL from I-70
southeast.
Lingered a chance of rain showers in southeast IL Thu morning then
low pressure moves into south-central PA by midday Thu and far enough
way to end rain chances Thu afternoon. Much cooler highs Thu in the
mid to upper 40s central IL and near 50F southeast IL. Even colder
Friday with highs in the upper 30s and lower 40s, coolest from I-74
ne. Models have been consistent in digging strong upper level trof
into the eastern states Thu/Fri bringing in the very cool
temperatures. 1030 mb Canadian high pressure settles into the Great
Lakes region Fri night and Sat with clouds and winds decreasing and
continued cold temps. Lows Fri night in the low to mid 20s. Highs
Sat in the low to mid 40s.
A cutoff upper level low passes north of the Great Lakes Sunday
keeping best chances of precipitation north of central IL, though
did carry small chances of light rain showers Sunday. Milder highs
Sunday and Monday in the mid to upper 50s with west central IL
around 60F.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 638 AM CDT TUE MAR 24 2015
Initial concern will be light freezing rain at SPI and DEC through
14z. Surface temperatures will be right around the freezing mark
through this time frame so some light icing is not out of the
question before temperatures edge into the middle 30s by mid to
late morning. Further north and east, the latest short term models
suggest the precip may struggle to shift north before 15z so will
hold back the precip threat up at PIA and BMI until after 15z. By
then, it appears the precip would be mostly rain with the
possibility for some isolated convection over parts of west
central and central IL during the morning. For now, will hold off
mentioning any -tsra during the morning, with the better threat for
isolated thunderstorms coming along this evening, as low pressure
passes across IL. MVFR and local IFR cigs will prevail thru most
of this forecast period with periods of rain through this
evening. Rain should come to an end from SW to NE as the low pulls
away into Indiana after midnight.
Surface winds will remain out of the east today, with a gradual
turn into the southeast and then south this evening as the surface
low approaches our area. Wind speeds will range from 12 to 17 kts
with gusts around 22 kts at times this afternoon and early this
evening.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...07
AVIATION...Shimon
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1115 AM EDT TUE MAR 24 2015
.UPDATE...
ISSUED AT 1115 AM EDT TUE MAR 24 2015
14Z SFC ANALYSIS SHOWS A STATIONARY FRONT LYING ACROSS KENTUCKY
AMIDST A TIGHT BAROCLINIC ZONE. AS SUCH...TEMPERATURES VARY WIDELY
ACROSS THE BOUNDARY FROM THE UPPER 30S AND LOWER 40S NORTHWEST TO
THE MID AND UPPER 50S IN THE SOUTHEAST. MID LEVEL CLOUDS HAVE
PUSHED BACK INTO THE AREA ALONG THE FRONT WHILE SOME LIGHT RAIN IN
FOUND THE NORTH OF THE BOUNDARY...GENERALLY ALONG AND NORTH OF
THE OHIO RIVER. DEWPOINTS RANGE FROM THE UPPER 20S IN THE
NORTHEAST PARTS OF THE CWA WHILE LOW 40S ARE FOUND NEAR THE
TENNESSEE BORDER. THE LATEST HRRR AND NAM12 SHOW PATCHES OF LIGHT
RAIN MOVING INTO THE NORTHERN PARTS OF THE AREA DURING THE
AFTERNOON AND INTO THE EVENING. HAVE ADJUSTED THE FORECAST TO
LIMIT ANY PCPN UNTIL AFTER 1 PM AND ALSO TO FINE TUNE SKY COVER
THROUGH THE FIRST PART OF THE EVENING. DID TWEAK THE MAXT...T...
AND TD GRIDS PER THE LATEST SHORTBLEND GUIDANCE...OBS...AND
TRENDS. UPDATED GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS
WITH A FRESHENED SET OF ZONES TO FOLLOW.
UPDATE ISSUED AT 824 AM EDT TUE MAR 24 2015
FRESHENED UP THE HOURLY TEMPERATURES...DEW POINTS AND SKY COVER TO
BETTER JIVE THE LATEST TRENDS IN OBSERVATIONS...OTHERWISE THE
FORECAST REMAINS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 409 AM EDT TUE MAR 24 2015
SURFACE HIGH PRESSURE IS CURRENTLY CENTERED ACROSS SOUTHEAST
CANADA...WITH LOW PRESSURE MOVING FROM THE FRONT RANGE OF THE
ROCKIES INTO THE HIGH PLAINS. A QUASI-STATIONARY FRONT EXTENDS
EAST FROM THE LOW...BECOMING MORE ILL-DEFINED CLOSER TO
TN/KY...ALTHOUGH THE TEMPERATURE GRADIENT IS PRETTY STOUT WITH
30S IN NORTHERN KY/SOUTHERN OH...AND 50S IN TENNESSEE. ALOFT...AN
UPPER LEVEL TROUGH IS MOVING THROUGH THE ROCKIES...WITH RIDGING
ACROSS THE PLAINS.
THE MODELS ARE IN GOOD AGREEMENT THAT A LEAD SHORT WAVE TROUGH
WILL EJECT OUT OF THE ROCKIES TROUGH AND BECOME NEGATIVELY TILTED
AS IT MOVES ACROSS THE PLAINS LATER TODAY...EVENTUALLY MOVING
INTO THE OHIO VALLEY/GREAT LAKES BY WEDNESDAY. THE SURFACE LOW
WILL FOLLOW SUIT...INITIALLY ALLOWING A WARM FRONT TO MOVE NORTH
INTO THE OHIO VALLEY LATER TONIGHT...BEFORE A COLD FRONT QUICKLY
FOLLOWS FOR WEDNESDAY...ALTHOUGH THE SOUTHERN PORTION OF THE FRONT
WILL BE WEAKENING AS THE UPPER LEVEL FORCING SAILS OFF TO THE
NORTH AND EAST.
FOR EASTERN KENTUCKY...TODAY WILL FEATURE QUITE A BIT OF VARIATION
WITH THE HIGH TEMPERATURES...AS LOCATIONS NORTH OF I-64 WILL
REMAIN CLOUDIER AND COOLER WITH READINGS IN THE LOW 50S...WHILE
SOME SUNSHINE AND SOUTHWEST FLOW HELP PUSH HIGHS TO AROUND 70
ALONG AND SOUTH OF THE HAL ROGERS AND HIGHWAY 80 CORRIDORS. A
MODEST LOW LEVEL JET NOSING IN FROM THE WEST WILL ALLOW FOR SOME
SHOWERS TO THREATEN...MAINLY NORTH OF THE MOUNTAIN PARKWAY THIS
AFTERNOON INTO EARLY THIS EVENING. A LULL IN THE POPS WILL OCCUR
LATER THIS EVENING AS THE WARM FRONT LIFTS NORTH...HOWEVER AS THE
COLD FRONT APPROACHES FROM THE WEST OVERNIGHT INTO
WEDNESDAY...POP CHANCES WILL INCREASE ONCE AGAIN...WITH HIGHER
VALUES NORTHWEST...AND LOWER ONES SOUTHEAST. ELEVATED INSTABILITY
OUT AHEAD OF THE COLD FRONT CONTINUES TO BE SHOWN IN THE
MODELS...SO WILL MAINTAIN SLIGHT CHANCES FOR THUNDER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 431 AM EDT TUE MAR 24 2015
WE BEGIN THE PERIOD WITH FIRST FRONTAL BOUNDARY AND LOW PRESSURE
SYSTEM PUSHING EAST AND NE OF THE REGION. RIGHT NOW THE GFS WANTS
TO KEEP QPF SIGNALS ALONG THE BAROCLINIC ZONE...HOWEVER IT SEEMS
TO BE THE ODD MODEL OUT AT THIS POINT. CONSEQUENTLY LEANED TOWARD
PREVIOUS FORECAST AND MODEL BLENDS FOR THIS PERIOD. THIS KEEPS
SLIGHT POPS IN BETWEEN THESE TWO UPPER LEVEL INDUCED SYSTEMS.
OPTED TO KEEP SLIGHT CHANCE THUNDER GIVEN REASONABLE ELEVATED
INSTABILITY IN PLACE. THE SECOND LOW PRESSURE WILL BEGIN FORMING
ACROSS THE CENTRAL PLAINS WEDNESDAY NIGHT AND WILL BE THE NEXT
MORE SUBSTANTIAL WEATHER MAKER IN THE PERIOD. THIS FEATURE WILL
MOVE NE ALONG THE BAROCLINIC ZONE AS LONG WAVE TROUGH PROGRESSES
EAST. EVENTUALLY SWINGING A STRONG COLD FRONT ACROSS THE REGION
THURSDAY. THIS WILL GIVE BEST CHANCES FOR POPS THROUGH THE PERIOD
WITH THUNDER POSSIBLE ALONG AND NEAR THE FRONT. ONCE AGAIN DECENT
INSTABILITY WITH LAPSE RATES AOA 6.5C PER KM EARLY ON THURSDAY
MAKES THIS SEEM REASONABLE. THINK THE THUNDER WILL DROP OFF
THROUGH THE DAY AS STRONG COLD FRONT WILL USHER IN COLDER AIR
BEHIND IT. THEREFORE DID OPT TO LEAN TOWARD A NON DIURNAL CURVE
THURSDAY WITH TEMPS DROPPING FROM NW TO SE THROUGH THE LATE
AFTERNOON. THIS FRONT WILL PROGRESS EAST THURSDAY NIGHT AND THE
BEST PRECIP CHANCES WILL GO WITH THE FRONT.
SOME QUESTIONS REMAIN FOR FRIDAY ON HOW MUCH MOISTURE WILL BE LEFT
OVER AS ENERGY ASSOCIATED WITH THE UPPER LEVEL TROUGH SWINGS
ACROSS THE OHIO VALLEY. DID LEAN TOWARD THE BLEND WHICH DOES KEEP
SLIGHT TO CHANCE POPS FROM SW TO NE. SOME SLIGHT CHANCE POPS
LINGER INTO FRIDAY NIGHT SUPPORTED BY THE GFS AND GEM. GIVEN THAT
FORECAST SOUNDINGS SUPPORT MIX TO SOME WET FLAKES HAVE
TRANSITIONED TO THIS OVERNIGHT. OTHERWISE IN THE WAKE OF THIS
STRONG COLD FRONT A CANADIAN HIGH IS FORECAST TO DROP SOUTHEAST.
THIS WILL SET THE STAGE FOR CLEARING SKIES AND MUCH COLDER TEMPS
ACROSS EASTERN KENTUCKY MOVING INTO THE WEEKEND. WHILE FRIDAY
NIGHT WILL FEATURE COLD TEMPERATURES WITH LOWS IN THE MID TO UPPER
20S. CLOUDS WILL SLOWLY CLEAR OUT OVERNIGHT AND THE HIGH WILL
STILL BE NOSING INTO THE REGION. SATURDAY WILL FEATURE SUNNY SKIES
AS DRIER AND COOLER AIR CONTINUE TO FILTER INTO THE REGION. BEST
CHANCE FOR RADIATIONAL COOLING AND CLEAR SKIES WILL BE SATURDAY
NIGHT...AS HIGH PRESSURE MOVES RIGHT OVER EASTERN KENTUCKY. THERE
IS STILL A FAIR AMOUNT OF UNCERTAINTY ON SURFACE HIGH
PLACEMENT...AND THESE TEMPS COULD NEED TO BE BUMPED DOWN FROM THE
LOW TO MID 20S THAT ARE IN THE GRIDS DEPENDING ON HOW THIS PLAYS
OUT. THIS AREA OF HIGH PRESSURE WILL SHIFT SE OF THE REGION SUNDAY
LEADING TO RETURN FLOW. HIGH TEMPS WILL BOUNCE BACK INTO THE LOW
TO MID 50S. MODELS BECOME QUITE DIVERGENT BY SUNDAY NIGHT INTO
MONDAY AS ANOTHER UPPER LEVEL WAVE DROPS SOUTHEAST. RIGHT NOW THE
GFS IS MUCH MORE PROGRESSIVE BRINGING A COLD FRONT SOUTH BY SUNDAY
NIGHT...WHILE THE ECMWF BRINGS THIS FEATURE DOWN LATER MONDAY.
STUCK WITH BLEND AT THIS POINT GIVEN THE GREATER UNCERTAINTY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 824 AM EDT TUE MAR 24 2015
EXPECT VFR CONDITIONS TO HOLD ON THROUGH THE PERIOD ACROSS THE
AREA. A WEAK WARM FRONT WILL THEN DEVELOP DURING THE
DAY...ALLOWING FOR SOME SHOWER ACTIVITY AS WELL AS LOWER
CEILINGS...ALTHOUGH STILL VFR. THE BOUNDARY WILL EVENTUALLY LIFT
NORTH OF EASTERN KENTUCKY LATER TONIGHT...BEFORE A COLD FRONT
APPROACHES FROM THE WEST TOWARD DAWN WEDNESDAY MORNING...
THREATENING MAINLY THE I-64 CORRIDOR WITH SHOWERS AND PERHAPS A
RUMBLE OF THUNDER. WINDS WILL BE OUT OF THE ENE AT 5 TO 10 KTS
INITIALLY AND THEN LIGHTEN UP TOWARDS DUSK. WINDS WILL THEN BECOME
OUT OF SOUTH AT 5 TO 10 KTS BETWEEN 08 AND 12Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
716 AM EDT TUE MAR 24 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 557 AM EDT TUE MAR 24 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MESSY COMPLEX OF
SHORTWAVE ENERGY MOVING ACROSS THE PACIFIC NW AND ROCKIES. LEAD
ENERGY IS ALREADY GENERATING SHRA/TSRA ACROSS THE CNTRL PLAINS EARLY
THIS MORNING. CLOSER TO HOME...SHORTWAVE RIDGE OVER MN IS SUPPORTING
SFC HIGH PRES OVER THE GREAT LAKES. ASSOCIATED DRY AIR
MASS/SUBSIDENCE AHEAD OF RIDGE IS RESULTING IN CLEAR SKIES ACROSS
THE UPPER LAKES EARLY THIS MORNING. WITH LIGHT/CALM WIND...TEMPS IN
THE INTERIOR E HALF HAVE FALLEN INTO THE LOWER TEENS AND SINGLE
DIGITS WITH A FEW SPOTS RECENTLY NEAR 0F. OUT W...20S ARE MORE
COMMON WITH A LIGHT S WIND STIRRING.
MID/UPPER RIDGE SHIFTING ACROSS THE WRN GREAT LAKES TODAY ALONG WITH
DRY AIR MASS WILL RESULT IN ABUNDANT SUNSHINE. HIGH WILL REACH THE
40S OVER THE MUCH OF THE W HALF. S TO SE WINDS OFF LAKE MI WILL KEEP
THE E HALF COOLER IN THE 30S...PROBABLY LOW 30S NEAR THE SHORE OF
LAKE MI.
TONIGHT...ATTENTION TURNS TO THE MULTIPLE SHORTWAVES CURRENTLY
MOVING ACROSS THE PACIFIC NW AND ROCKIES. LEAD ENERGY MOVING OUT
ACROSS NE/KS THIS AFTN IS STILL FCST TO TAKE ON A NEGATIVE TILT AS
IT MOVES TO VCNTY OF SRN LAKE MI BY 12Z WED WHILE ANOTHER SHORTWAVE
MOVES ACROSS THE DAKOTAS INTO MN. THIS WILL LEAD TO 2 SFC LOW
CENTERS AT 12Z WED...ONE OVER NW MN AND THE SECOND IN THE VCNTY OF
SRN LAKE MI. OVER THE LAST FEW DAYS...MODELS HAVE PERSISTENTLY
OVERALL TRENDED SLIGHTLY SE WITH EACH SUCCESSIVE MODEL RUN IN REGARD
TO THE SRN SHORTWAVE/SFC LOW. THAT TREND HAS CONTINUED WITH THE 00Z
MODELS. FOR THE FCST AREA...THIS MEANS HEAVIEST PCPN SHOULD PASS BY
TO THE SE OF HERE...AND PCPN SHOULD FALL ALMOST EXCLUSIVELY AS SNOW
AS IT ARRIVES FROM THE S AND SW LATE TONIGHT. THERE IS STILL JUST
ENOUGH UNCERTAINTY IN THERMAL PROFILES TO INCLUDE A MENTION OF -FZRA
CLOSE TO LAKE MI WHERE WARM NOSE ALOFT OF ABOVE FREEZING TEMPS WILL
COME CLOSE TO THAT AREA. UTILIZED MOSTLY A CONSENSUS APPROACH OF ALL
AVBL GUIDANCE...WEIGHTED TOWARD HIGH RES GUIDANCE (NAM/GEM AND NCEP
HRW-ARW/NMM)...TO CONSTRUCT POPS/QPF TONIGHT. RESULT IS PCPN
SPREADING N AND NE INTO THE FCST AREA AFTER 06Z. IT`S POSSIBLE THE
SNOW MAY NOT ARRIVE OVER THE FAR N AND E FCST AREA UNTIL AROUND 12Z
WED. RESULT FOR QPF IS ROUGHLY 0.10 TO 0.25 INCHES BY 12Z...HIGHEST
IN SRN MENOMINEE COUNTY. VIGOROUS DYNAMICS AND HEALTHY ISENTROPIC
ASCENT NOTED ON 290K SFC SHOULD LEAD TO DECENT PCPN RATES DURING
PEAK FORCING WHICH REACHES THE WI BORDER IN THE 09Z-12Z TIME FRAME.
ALTHOUGH MIXING RATIOS OF 3-4G/KG ARE AVBL AROUND 750MB...SHORT
DURATION OF STRONG FORCING AND LOWER SNOW TO WATER RATIOS DOWN TO 10-
15 TO 1 MAKE FOR LOWER CONFIDENCE ON SNOW ACCUMULATIONS REACHING
ADVY LEVEL. AT THIS POINT...CONSENSUS HERE IS TO HOLD OFF ON ADVY
HEADLINES...ESPECIALLY SINCE THIS IS A VERY LATE 2ND PERIOD AND 3RD
PERIOD EVENT. IF NEXT ROUND OF MODEL RUNS TODAY PAINT A SLIGHTLY
HIGHER QPF PICTURE...CAN FORESEE ADVY HEADLINES FOR POSSIBLY THE E
HALF OF THE FCST AREA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 517 AM EDT TUE MAR 24 2015
FCST MODELS CONTINUE TO MERGE ON A THEME OF HAVING THE INITIAL LOW
FROM THE SW OVER CENTRAL LAKE MI AROUND 12Z WEDNESDAY. THE RESULT
HAS BEEN A TREND TO LESS PRECIP AND MORE IN THE FORM OF SNOW INSTEAD
OF FREEZING RAIN WEDNESDAY MORNING.
PRECIP WILL OVERSPREAD THE REST OF THE CWA WEDNESDAY MORNING. THIS
QUICK BLAST OF MOISTURE WILL ALREADY BE PULLING OUT OF THE SW CORNER
OF UPPER MI BY 18Z WEDNESDAY...AND IF THE 23/18Z RUN OF THE CANADIAN
IS CORRECT MUCH OF THE SW AND CENTRAL CWA. THIS WILL BE WHILE THE
SFC LOW SHIFTS ACROSS E UPPER MI AND NW LAKE HURON BY 18Z...AND
GENERALLY BETWEEN CYLD AND CYXR IN SE ONTARIO BY 00Z THURSDAY. WITH
SFC TEMPS GETTING INTO THE UPPER 30S AND LOW 40S WEDNESDAY
AFTERNOON...SNOW WILL BE DIFFICULT TO MAINTAIN. WHILE A MIX IS
REPRESENTED IN THE FCST...UPPER MI WILL BE IN A LULL...WITH MUCH OF
THE BEST MOISTURE WILL BE ALREADY GONE.
UPDATED THE SPS TO INCLUDE THE COUNTIES OF MENOMINEE TO ALGER AND
E...WHERE THE GREATEST POTENTIAL FOR OVER 2IN OF SNOW EXISTS...ALONG
WITH A BRIEF PERIOD OF FREEZING RAIN.
WILL NEED TO WAIT UNTIL THE SECONDARY SFC LOW /OVER NW MN AT 12Z
WEDNESDAY/ EXITS THE PICTURE. IT SHOULD MOVE OVER NE MN AT 18Z
WEDNEDAY...AND JOIN FORCES WITH THE MAIN LOW EARLY WEDNESDAY EVENING
OVER LAKE SUPERIOR AND SE ONTARIO. 850MB TEMPS STILL AROUND -5C AT
00Z THURSDAY WILL FALL TO AROUND -15C OVER THE W BY 12Z THURSDAY ON
N-NW WINDS. THE RESULT...WITH THE ASSISTANCE OF THE SIZABLE 500MB
TROUGH OVERHEAD CONTINUING TO BRING A SERIES OF SHORTWAVES ACROSS
UPPER MI...WILL BE LIGHT TO AT TIMES MODERATE LES THROUGH THURSDAY
EVENING.
THE 500MB TROUGH WILL EVENTUALLY SHIFT TO OUR SE...MAKING WAY FOR A
RIDGE SATURDAY INTO EARLY SUNDAY. AT THIS POINT...WITH HIGH PRESSURE
AT THE SFC AND ALOFT...DRY WEATHER IS FIGURED FROM LATE MORNING
FRIDAY THROUGH THE DAY SATURDAY.
THE 00Z RUN OF THE ECMWF IS MORE ROBUST WITH THE PRECIP SUNDAY
MORNING. LOOKS LIKE ANOTHER POTENTIAL RAIN/SNOW SITUATION. WHILE THE
ECMWF WOULD INDICATE WARMER AIR AND A BETTER CHANCE OF RAIN...THE
GFS IS MUCH COOLER AND WOULD GIVE MAINLY RAIN. WILL CONTINUE WITH A
MODEL BLEND FOR THIS PERIOD...UNTIL A MORE SOLID CONSENSUS IS
DEVELOPED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 716 AM EDT TUE MAR 24 2015
VERY DRY AIR IN THE LOW TO MID LEVELS ASSOCIATED WITH HIGH PRES
MOVING E ACROSS THE LOWER GREAT LAKES TODAY WILL ENSURE VFR
CONDITIONS AT KIWD/KCMX/KSAW THROUGH THIS EVENING. LOW PRES LIFTING
NE TOWARD LAKE MICHIGAN TONIGHT WILL SPREAD SNOW INTO UPPER MI LATE
TONIGHT. NEAR THE END OF THE FCST PERIOD...IFR CONDITIONS SHOULD
REACH KIWD WITH MVFR AT KCMX/KSAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 557 AM EDT TUE MAR 24 2015
WITH HIGH PRES OVER THE GREAT LAKES REGION SHIFTING E WHILE LOW PRES
DEVELOPING OVER THE SRN PLAINS MOVES NE...WINDS WILL INCREASE TODAY
AND TONIGHT. SINCE PRES GRADIENT REMAINS RELATIVELY WEAK...WINDS
ACROSS LAKE SUPERIOR SHOULD REMAIN MOSTLY UNDER 20KT...THOUGH HIGH
OBS PLATFORMS WILL PROBABLY SEE SOME GUSTS TO AROUND 25KT. WINDS
WILL DIMINISH WED AS LOW PRES TROF SETS UP ACROSS THE LAKE BTWN ONE
LOW PRES CENTER MOVING E TOWARD LAKE SUPERIOR AND THE OTHER LIFTING
NE THRU LWR MI INTO ONTARIO. THE TROF WILL DROP S OF THE LAKE WED
NIGHT...AND WINDS WILL THEN INCREASE INTO THU AS HIGH PRES BUILDS S
TOWARD THE NRN PLAINS AND MUCH COLDER AIR SPREADS SE INTO THE UPPER
LAKES. NORTHERLY WINDS SHOULD INCREASE TO 20-30KT THU...AND IT`S NOT
OUT OF THE QUESTION THAT GALE FORCE GUSTS COULD OCCUR FOR A TIME
OVER CNTRL PORTIONS OF LAKE SUPERIOR. WINDS WILL THEN DIMINISH FRI
AS THE HIGH PRES ARRIVES OVER THE WRN GREAT LAKES. WIND WILL BEGIN
TO RAMP UP AGAIN SAT...ESPECIALLY LATE...AS THE HIGH SHIFTS TO THE
OHIO VALLEY AND LOW PRES DROPS SE INTO MANITOBA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
719 AM CDT TUE MAR 24 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT TUE MAR 24 2015
TOUGH FORECAST AHEAD FOR THIS AFTERNOON AND TONIGHT ON PTYPE AND
RESULTING PRECIPITATION AMOUNTS. THERE WAS QUITE THE DIFFERENCE
OUT THE GATE WITH THE 00Z RUNS BETWEEN THE NAM/GFS VERSUS THE
ECMWF/CANADIAN ON THE LAYOUT OF THE PRECIPITATION PATTERN
DEVELOPING LATER THIS AFTERNOON AND SPREADING ACROSS THE FA
TONIGHT. THE ECMWF AND CANADIAN ARE MUCH FARTHER SOUTH ON THE QPF
AXIS WITH A QUARTER INCH TONIGHT BARELY ACROSS THE SOUTHEAST PART
OF MN WHILE THE NAM/GFS HAVE THE QUARTER INCH INTO THE TWIN
CITIES. A CHECK ON RAP RUNS OVERNIGHT INDICATED A QPF PATTERN
DEVELOPING LIKE WHAT THE ECMWF AND CANADIAN ARE SHOWING. WE
BELIEVE PART OF REASON FOR THE DIFFERENCE IS THE CONVECTION
ONGOING TO OUR SOUTH THIS MORNING WITH STRONGER ACTIVITY PROGGED
FOR THIS AFTERNOON. THE NOSE OF THE 925-850MB MOISTURE TRANSPORT
WITH THE ECMWF JUST REACHES UP INTO NE IA THIS EVENING AND THEN
PASSES ACROSS SOUTHERN WI THIS EVENING. OUR INTERNAL MPX ARW-WRF
IS ALSO SHOWING THE QPF AXIS FURTHER SOUTH AS WELL. PTYPE THIS
AFTERNOON IS IN QUESTION WITH THE HRRR AND RAP SOUNDINGS
INDICATING SURFACE DEW POINTS RISING INTO THE LOWER AND MIDDLE 30S
ACROSS SOUTHERN MN WITH ALL RAIN INDICATED. THEY MAY BE TOO WARM
AS OUR MPX WRF SHOWS A CHANGE OVER TO SNOW ACROSS SOUTH CENTRAL MN
IN THE 21Z-24Z TIME FRAME ALONG WITH SOME FREEZING RAIN. HEADING
THROUGH THE EVENING...A DEEP MID LEVEL WAVE WILL PASS ACROSS IA/MO
WITH A DEFORMATION ZONE FROM NEAR KAEL TO KEAU. THIS IS THE ZONE
FOR 2 TO 4 INCHES OF SNOW ACCUMULATION TONIGHT WITH MUCH OF IT
OCCURRING BEFORE 06Z. SNOW AMOUNTS ARE LESS TO THE NORTHWEST WITH
AN INCH OR TWO IN THE TWIN CITIES WITH AROUND AN INCH AT ST.
CLOUD. BASED ON PTYPE ISSUES THIS AFTERNOON ALONG WITH THE SNOW
TONIGHT COUPLED WITH SOME MIXED SLEET AND FREEZING RAIN...WE
ISSUED A WINTER WEATHER ADVISORY FOR SOUTH CENTRAL MN BEGINNING
LATE THIS AFTERNOON WITH THE ADVISORY SPREADING NORTHEAST ACROSS
MUCH OF WEST CENTRAL WI FOR TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 410 AM CDT TUE MAR 24 2015
THE EXTENDED IS ACTUALLY LOOKING FAIRLY QUIET WITH THE MAIN
HAPPENINGS BEING THAT OF A PATTERN SHIFT...WITH A HIGHLY AMPLIFIED
PATTERN THIS WORK WEEK FLATTENING OUT AND BECOMING MORE ZONAL THIS
WEEKEND INTO NEXT WEEK. THE RESULT...TEMPS WILL REMAIN WELL BELOW
NORMAL THE REST OF THIS WORK WEEK...BUT BY THE WEEKEND...THEY WILL
REBOUND BACK TO NEAR OR EVEN A LITTLE ABOVE NORMAL.
THE LONG TERM WILL START WITH TONIGHTS TROUBLE MAKER PUSHING OUT OF
THE MPX AREA WEDNESDAY MORNING. GUIDANCE HAS CONTINUED TO PUSH WRAP
AROUND PRECIP WED/WED NIGHT FARTHER NORTH. IT IS LOOKING MORE AND
MORE LIKELY THAT THE MPX AREA WILL REMAIN DRY THIS PERIOD AS THE
WRAP AROUND MOISTURE STAYS CLOSER TO THE NRN SFC LOW THAT WILL BE
TRACKING ACROSS THE ARROWHEAD. HAVE CONTINUED THE TREND OF CUTTING
BACK POPS ON WEDNESDAY...WITH WED/WED NIGHT NOW BASICALLY DRY SOUTH
OF I-94. WHAT LOOKS MORE CERTAIN FOR WEDNESDAY ARE BREEZY
CONDITIONS. THE NAM SHOWS 3 HR PRESSURE RISES OF ABOUT 6 MB
FOLLOWING THE SFC LOW ACROSS THE ARROWHEAD...WITH 3 MB/3 HR RISES
ALL THE WAY DOWN INTO CENTRAL MN. IN ADDITION...BUFR SOUNDINGS UP AT
AXN SHOW MID CHANNEL MIX DOWN WINDS NEAR 35 KTS WITH TOP OF THE
CHANNEL WINDS AROUND 40 KTS. AS A RESULT...GAVE FORECAST WIND SPEEDS
A PRETTY GOOD BOOST FOR WEDNESDAY...WITH BORDERLINE WIND ADVY WINDS
NOW IN PLACE ACROSS WEST CENTRAL MN.
FOR THURSDAY AND FRIDAY...THE H5 FLOW BECOMES ALMOST NORTHERLY...
WHICH WILL ALLOW A 1035MB HIGH TO DROP DOWN OUT OF CANADA. WITH H85
TEMPS DOWN BETWEEN -6 TO -10C...WE WILL SEE HIGHS REMAIN IN THE 30S
BOTH DAYS...WITH SOME LOWS IN THE SINGLE DIGITS NOT OUT OF THE
QUESTION FRIDAY MORNING AS THE SFC HIGH SETTLES OVER MN AND OUR SNOW
COVER. THE ONE CHANGE SEEN WITH THE GUIDANCE THIS PERIOD IS THE
GEM/GFS/ECMWF ARE ALL SHOWING A QUICK HIT OF LIGHT PRECIP WORKING
ACROSS THE ERN DAKOTAS AND FAR WRN MN FRI/FRI NIGHT AS SHORT WAVE
ENERGY DROPPING DOWN IN THE NRLY FLOW WORKS WITH THE BAROCLINIC ZONE
ON THE BACKSIDE OF THE HIGH TO PRODUCE SOME LIGHT QPF. STILL HAVE A
DRY FORECAST OUT THAT DIRECTION...BUT IF THIS TREND CONTINUES...WE
MAY NEED TO START ADDING SOME SNOW CHANCES TO THE WEST FOR FRIDAY
EVENING.
THIS WEEKEND...AS THE UPPER FLOW BECOMES LESS AMPLIFIED...WE WILL
SEE A DEEP SFC LOW DROP OUT OF THE CANADIAN ARCTIC AND MOVE TOWARD
NW QUEBEC. WE WILL BE WELL WITHIN THE WARM SECTOR OF THIS SYSTEM...
THOUGH SAID WARM SECTOR IS STILL SCHEDULED TO COME THROUGH IN THE
DEAD OF NIGHT SATURDAY NIGHT. THE GEM/GFS BOTH HAVE A NICE SWATH OF
QPF WORKING DOWN WITH THE FRONT...BUT THE ECMWF CONTINUES TO BE DRY.
WITH THE GULF STILL CUT-OFF...THESE TYPES OF PATTERNS/FROPAS ARE
USUALLY DRY FOR US...SO DEFINITELY FAVOR THE DRIER ECMWF SOLUTION.
HOWEVER...WITH THE GEM/GFS IN THE BLENDING PROCEDURE USED...WE DO
HAVE POPS SPREAD ACROSS THE ENTIRE AREA SAT NIGHT...WITH THE HIGHEST
POPS OVER WI.
AFTER THIS WEEKEND...BOTH THE GFS/ECMWF SHOW THE REGION BEING DRY
UNTIL ANOTHER POWERFUL SPRING SYSTEM SHOWS UP TO WELCOME US TO APRIL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 719 AM CDT TUE MAR 24 2015
IFR/LOW MVFR CEILINGS COVER THE MN TAF SITES THIS AM. WE MAY
STRUGGLE FOR MUCH IMPROVEMENT IN THE MN RIVER VALLEY TODAY WITH A
MOIST SOUTHEAST LOW LEVEL FLOW WITH CEILINGS KEPT IN PLACE. LOW
MVFR CEILINGS MAY EVEN SNEAK BACK IN AT KRNH AND KEAU FOR A TIME
THIS MORNING ALTHOUGH CONFIDENCE IS NOT HIGH. SEVERAL RUNS OF THE
HRRR STILL SHOW THAT ANY MVFR CEILINGS FROM KMSP WILL MOVE OUT
EARLY THIS AFTERNOON. PRECIPITATION TRENDS HAVE CHANGED SOME SINCE
THE LAST TAF ISSUANCE. SHORT TERM SOLUTIONS ARE INDICATING A
SLOWER ONSET FOR THE TWIN CITIES ON EAST AND THIS WAS INCORPORATED
INTO THE NEW SET. A MIX OF RAIN AND SNOW SHOULD SWITCH OVER TO
SNOW FROM THE TWIN CITIES ON EAST AND SOUTH THIS EVENING WITH A
BAND OF MODERATE SNOW TO THE SOUTHEAST OF THE TWIN CITIES TO KEAU.
DRIER MID LEVEL AIR WILL WORK IN FROM THE SOUTHWEST LATE IN THE
NIGHT...ENDING PRECIP TO THE WEST AND SOUTH OF THE TWIN CITIES. SE
WINDS GUSTING 15-20 KNOTS TODAY VEERING WESTERLY LATE TONIGHT.
KMSP...LOW MVFR CEILINGS ARE BACK BUT EXPECT A BREAK OUT TO VFR
THIS AFTERNOON BEFORE DETERIORATING BACK DOWN TO LOW MVFR/IFR
TONIGHT. RAIN/SNOW SPREADING IN AFTER 25/00Z CHANGING TO ALL SNOW
BY 03Z AND CONTINUING UNTIL ABOUT 09Z. SNOWFALL RATES ARE EXPECTED
TO BE HIGHEST FROM 03Z-06Z WITH AROUND A 1/2 INCH PER HOUR.
/OUTLOOK FOR KMSP/
WED...MVFR. WINDS W 15G25 KTS.
THU...MVFR AND -SN POSSIBLE EARLY. WINDS NNW 15G25 KTS.
FRI...VFR. WINDS NW 5-10 KTS BCMG SW IN THE AFTN.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM CDT
WEDNESDAY FOR MNZ082>085-091>093.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 4 AM CDT
WEDNESDAY FOR MNZ077-078.
WI...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT
WEDNESDAY FOR WIZ024>028.
&&
$$
SHORT TERM...RAH
LONG TERM...MPG
AVIATION...RAH
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
957 AM MDT TUE MAR 24 2015
.UPDATE...
UPDATED FORECAST TO FOLLOW RADAR TRENDS WITH PRECIPITATION
DECREASING OVER THE EAST WITH BOWMAN RADAR SHOWING WRAP AROUND
BAND PULLING OUT OF BAKER. BAKER HAD SNOW CHANGE BACK OVER TO
RAIN AND EVEN THE BACK EDGE OF THE LOW CLOUDS SHOULD BE
PROGRESSIVE THROUGH THE AREA. LOWERED CLOUD COVER IN CENTRAL ZONES
AS VISIBLE SATELLITE SHOWS A GOOD BREAK AHEAD OF THE
DESTABILIZATION FROM THE SYSTEM MOVING THROUGH IDAHO. DIURNAL
HEATING AND COOLING ALOFT WILL SUPPORT INCREASING CONVECTIVE
ACTIVITY THROUGH THE AFTERNOON WITH A SURFACE BOUNDARY SLIDING
THROUGH THE REGION IN THE EVENING. WHEN THIS BOUNDARY REACHES THE
FOOTHILLS AND MOUNTAINS IT WILL BECOME THE FOCUS FOR HEAVY SNOW
SHOWERS AND CURRENT HIGHLIGHTS LOOK GOOD. FURTHER NORTH ALONG THE
YELLOWSTONE RIVER VALLEY WILL SEE A RAIN SNOW MIX UNTIL MIDNIGHT
THOUGH RUC INDICATES SOME LOCAL FREEZING LEVEL LOWERINGS DUE TO
THE CONVECTIVE ACTIVITY. WITH WARM GROUND AND SHORT WIND FOR
SNOWFALL DO NOT EXPECT MUCH IN THE WAY OF ACCUMULATIONS LOWER
ELEVATIONS. BORSUM
&&
.SHORT TERM...VALID FOR TDY AND WED...
AN UNSETTLED WEATHER PATTERN IS EXPECTED TODAY AND WEDNESDAY WITH
THE HIGHLIGHT LIKELY BEING HEAVY SNOW SHOWERS IN THE BEARTOOTH AND
ABSAROKA MOUNTAINS AND THE RED LODGE FOOTHILLS...MAINLY TONIGHT.
TODAY...WRAP-AROUND MOISTURE IN THE FORM OF RAIN AND POSSIBLY EVEN
A MIX WITH SNOW WILL LINGER IN FAR SOUTHEASTERN MT...ESPECIALLY IN
THE BAKER AREA...THIS MORNING. OVERNIGHT RADAR AND MODEL DATA BOTH
SUGGEST A SLOWER AND DEEPER LOW- TO MID-LEVEL LOW MOVING NORTHEAST
INTO NORTH DAKOTA THIS MORNING IN SUPPORT OF THAT PRECIPITATION. A
COOLER AND BREEZY TO WINDY DAY IS EXPECTED IN THE WAKE OF THAT LOW
WITH CYCLONIC FLOW SUPPORTING LOW POPS MOST EVERYWHERE. HOWEVER...
FORECAST SOUNDINGS IN SOUTHEASTERN MT ARE NOT THAT UNSTABLE AND WE
DID NOT SEE MUCH SUPPORT FOR EVEN SHALLOW CONVECTION IN THE 00 UTC
HIGH-RESOLUTION MODEL OUTPUT...SO SLIGHT-CHANCE POPS MIGHT EVEN BE
TOO MUCH IN SOUTHEASTERN MT THIS AFTERNOON. BACK FURTHER WEST...WE
EXPECT INCREASING SHOWER ACTIVITY AFTER 18 UTC AS ANOTHER MID- AND
UPPER-LEVEL SHORTWAVE TROUGH BEGINS AFFECTING THE AREA. WE BEGAN A
WINTER STORM WARNING FOR THE BEARTOOTH/ABSAROKA RANGES AT NOON MDT
/18 UTC/ AS THAT WAVE APPROACHES AS SNOW SHOWERS SHOULD PICK UP IN
EARNEST AT THE HIGHER ELEVATIONS THIS AFTERNOON.
TONIGHT...A WEAK SOUTHWARD-MOVING FRONTAL PUSH IS EXPECTED AS THAT
SHORTWAVE TROUGH DROPS ACROSS WY. THAT WILL TURN LOW-LEVEL FLOW TO
A MORE NORTHERLY AND UPSLOPE TRAJECTORY AND THAT WILL COMBINE WITH
THE CYCLONIC FLOW ALOFT AND STEEP MID-LEVEL LAPSE RATES OF 7 C/KM
TO PRODUCE HEALTHY PRECIPITATION OVER AND NEAR THE HIGHER TERRAIN
OF SOUTH CENTRAL MT AND NORTH CENTRAL WY. THIS TYPE OF LARGE-SCALE
PATTERN FAVORS HEAVY SNOW ON THE NORTH SLOPES OF THE BEARTOOTH AND
ABSAROKAS AND IN THE FOOTHILLS AT RED LODGE...AND USING A BLEND OF
00 UTC HIGH-RESOLUTION WRF-NMM AND WRF-ARW MODEL DATA WITH A DASH
OF INPUT FROM A LOCALLY-RUN WRF-NMM PRODUCED AT NWS RIVERTON GAVE
LIQUID-EQUIVALENT MOISTURE TOTALS OF 0.70 TO 1.00 ON SLOPES WHICH
ARE FAVORED BY THE EXPECTED WIND DIRECTIONS. IT/S A BIT UNCLEAR AS
TO WHEN RAIN WILL CHANGE OVER TO SNOW DOWN TO RED LODGE...BUT NONE
OF THE MODEL GUIDANCE SUGGESTS IT WON/T DO SO BY LATE EVENING. OUR
FORECAST IS THUS A RELATIVELY HIGH-CONFIDENCE ONE IN SUPPORT OF 8
TO 14 INCHES OF SNOW OVER THE MOUNTAINS AND HIGHER...NORTH-FACING
SLOPES AND 5 TO LOCALLY 10 INCHES AROUND RED LODGE. WE THUS ISSUED
A WINTER STORM WARNING FOR THE RED LODGE FOOTHILLS AS WELL BETWEEN
6 PM MDT THIS EVENING AND 9 AM MDT WEDNESDAY...WHEN WE ALSO ENDED
THE WARNING FOR THE MOUNTAINS. THE HIGH-RESOLUTION MODEL GUIDANCE
WE USED TO BUILD THE FORECAST SUGGESTED LOWER TOTALS JUST BENEATH
ADVISORY-LEVEL CRITERIA IN THE BEARTOOTH FOOTHILLS LIKE AT MCLEOD
AND OVER THE NORTHEASTERN BIGHORN MOUNTAINS...AND SO CONFIDENCE IN
GETTING HEADLINE-WORTHY SNOW WASN/T HIGH ENOUGH FOR US TO ISSUE A
WINTER WEATHER ADVISORY IN THOSE LOCATIONS JUST YET. THERE WILL BE
SNOW IN THOSE PLACES THOUGH AND A LATER FORECAST MAY NEED TO ADD
IN SOME ADDITIONAL HEADLINES THERE.
OTHERWISE...WE ALSO HAVE CHANCE-STYLE POPS ELSEWHERE IN THE LOWER
ELEVATIONS OF SOUTH CENTRAL MT AND NORTH CENTRAL WY TONIGHT AS
WELL IN RESPECT TO THE SAME SCENARIO...ALBEIT WITH WEAKER FORCING
IN SUPPORT OF ONLY LIGHT MOISTURE TOTALS IN SPOTS LIKE BILLINGS.
WEDNESDAY...CYCLONIC FLOW WILL CONTINUE AND SO WILL SOME CHANCE
OF SHOWERS IN MOST AREAS. IT WILL ALSO STAY RELATIVELY COOL WITH
HIGHS ONLY IN THE 40S TO LOWER 50S F. SCHULTZ
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
MOIST NW FLOW WILL CONTINUE OVER THE REGION THURSDAY BUT LATEST
TRENDS ARE TO KEEP THE SFC TROF A BIT EAST OF BILLINGS AS RIDGE
BEGINS TO BUILD IN FROM THE WEST. THIS WILL RESULT IN WARMER AND
DRIER CONDITIONS IN OUR WEST HALF...WITH MUCH BETTER CHANCE OF
SHOWERS TO THE EAST ESPECIALLY AS WEAK BACKDOOR COOLING INCREASES
LOW LEVEL BAROCLINICITY. EXPECTING SOME MORE SNOW ACCUMULATION
OVER THE NW FLOW FAVORED BIGHORN MTNS...BUT LOWER ELEVATION
SNOWFALL SHOULD BE MINIMAL OR NONEXISTENT DUE TO MILD SFC TEMPS.
IT IS ALSO POSSIBLE THAT PARTS OF OUR EAST COULD MIX WITH A LITTLE
LIGHT FREEZING RAIN EITHER EARLY THURSDAY MORNING OR THURSDAY
NIGHT BEFORE PCPN ENDS AS WARM ADVECTION OVERRUNS THE
AFOREMENTIONED BACKDOOR COOL FRONT. AS FOR TEMPS...HAVE RAISED
THURSDAY HIGHS AND THURSDAY NIGHT LOWS SIGNIFICANTLY ESPECIALLY
FROM BILLINGS WEST. SHOULD SEE HIGHS ON THURSDAY BACK NEAR 60F OUT
WEST...AND ONLY IN THE 40S ALONG THE DAKOTAS BORDER.
UPPER RIDGE SHIFTS EAST ALLOWING FOR MUCH WARMER TEMPERATURES
FRIDAY AND SATURDAY. GIVEN H5 HEIGHTS INTO THE 570S AND 700MB
TEMPS ABOVE 0C WE WILL SEE TEMPS GET BACK TO THE UPPER 60S AND
70S. A BREAK DOWN OF THIS RIDGE IS IN STORE FOR SATURDAY BUT THERE
ARE TIMING ISSUES WHICH WILL SIGNIFICANTLY IMPACT HOW WARM IT MAY
GET ON SATURDAY. A QUICKER FRONTAL PASSAGE WILL OBVIOUSLY BEGIN A
COOL DOWN ON SATURDAY...BUT IF THE SLOWER ECMWF VERIFIES WE COULD
BE LOOKING AT SOME MID TO UPPER 70S IN A STRONG DOWNSLOPE AND
PREFRONTAL REGIME AHEAD OF A FROPA EITHER SATURDAY AFTERNOON OR
EVENING. A FEW HOURS COULD MAKE A BIG DIFFERENCE HERE.
SHOULD SEE AT LEAST SOME LIGHT SHOWER ACTIVITY ASSOCIATED WITH
WEAK WEEKEND CLIPPER...ALONG WITH A MODEST COOL DOWN INTO SUNDAY.
THIS IS EXPECTED TO BE A WEAK SYSTEM AND HEIGHTS REMAIN NEAR
570DAM ON SUNDAY...SO IMPACTS WILL BE MINIMAL. COULD SEE SOME
RESIDUAL SHOWERS OVER THE MOUNTAINS MONDAY BUT OTHERWISE MODEL
CONSENSUS IS FOR BROAD UPPER RIDGING. TEMPS WILL REMAIN ABOVE
NORMAL SUNDAY/MONDAY.
LOOKING A BIT FURTHER AHEAD...THERE IS POTENTIAL FOR A STRONGER
TROF AND INCREASED PCPN CHANCES BY NEXT TUESDAY/WEDNESDAY...BUT
PLENTY OF MODEL SPREAD EXISTS BOTH WITH THIS FEATURE AND FLOW IN
THE NORTHEAST PACIFIC. STAY TUNED.
JKL
&&
.AVIATION...
LIGHT PRECIPITATION AND IFR CONDITIONS WILL SLOWLY MOVE OUT OF
KBHK THIS MORNING. CONDITIONS SHOULD RISE TO VFR BY EARLY
AFTERNOON. THE REST OF THE AREA WILL HAVE VFR FLYING CONDITIONS.
SHOWERS WILL DEVELOP THIS AFTERNOON...ESPECIALLY IN THE MOUNTAINS.
SOME OF THE SHOWERS COULD CAUSE LOCAL MVFR CONDITIONS. THE
MOUNTAINS WILL BE OBSCURED. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 055 030/052 038/060 040/071 048/076 040/065 041/070
4/W 53/W 32/W 10/B 02/W 22/W 11/B
LVM 048 029/049 033/060 040/071 048/071 038/065 040/068
5/W 83/W 22/W 10/B 02/W 22/W 21/B
HDN 059 028/053 032/059 032/073 040/078 035/066 035/072
3/W 53/W 32/W 10/B 02/W 22/W 11/B
MLS 055 027/048 030/050 033/067 040/075 034/061 037/068
2/W 11/B 22/W 10/B 02/W 21/B 11/U
4BQ 057 026/048 030/050 029/068 040/077 035/064 036/070
2/W 11/B 24/W 20/B 02/W 21/B 11/B
BHK 046 024/042 024/045 027/061 036/073 032/059 033/065
7/W 11/B 22/W 21/E 02/W 21/U 11/U
SHR 054 027/046 030/053 032/068 039/076 036/065 035/070
3/W 54/W 34/W 20/B 02/W 22/W 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING IN EFFECT FROM 6 PM THIS EVENING TO 9 AM
MDT WEDNESDAY FOR ZONE 56.
WINTER STORM WARNING IN EFFECT UNTIL 9 AM MDT WEDNESDAY FOR
ZONE 67.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1016 AM CDT TUE MAR 24 2015
.SYNOPSIS...
ISSUED AT 335 AM CDT TUE MAR 24 2015
AT 08Z...TWO MAIN AREAS OF SURFACE LOW PRESSURE EXIST. ONE
LOCATED IN FAR ERN WY WHILE THE OTHER IN THE OKLA PNHDL. VERY
LITTLE CURRENTLY ON THE KLBF RADAR EXCEPT FOR A NARROW BAND OF
SHOWERS AND SPRINKLES FROM SWRN CUSTER COUNTY INTO SERN LINCOLN
AND FRONTIER COUNTY. SCATTERED SHOWERS AND THUNDERSTORMS
CURRENTLY EXTEND FROM PARTS OF NCTRL KS INTO SCTRL AND SERN NEBR
AND NWRN MISSOURI WITH JUST OVER 200 LIGHTNING STRIKES THE PAST
HOUR.
&&
.UPDATE...
ISSUED AT 1016 AM CDT TUE MAR 24 2015
FORECAST WAS UPDATED DUE TO RADAR AND CLOUD TRENDS FOR THIS
MORNING AS RAIN SHOWERS OVER NORTH CENTRAL NEBRASKA ARE
PROGRESSING EAST AND SHOULD BE MOSTLY OUT OF THE FORECAST AREA
BY EARLY AFTERNOON. WITH LOW PRESSURE CENTERED OVER SOUTHWEST
NORTH DAKOTA AT MID MORNING...A SURFACE TROUGH WAS LOCATED THROUGH
WESTERN SOUTH DAKOTA AND DOWN THROUGH THE EASTERN NEBRASKA
PANHANDLE. THIS TROUGH WILL MAKE ITS WAY EAST TODAY AND AS CLOUDS
CLEAR BEHIND THE ONGOING PRECIPITATION...WARMING AHEAD OF THE
TROUGH WILL ALLOW SOME VERY WEAK INSTABILITY TO BUILD ROUGHLY FROM
NORTH CENTRAL INTO CENTRAL NEBRASKA THIS AFTERNOON. IT WILL BE
WEAK WITH THE RAP SHOWING 100-200J/KG OF MUCAPE. THIS MAY BE
ENOUGH FOR SOME LIGHT RAIN SHOWERS TO DEVELOP ALONG THE TROUGH
THIS AFTERNOON SO DID ADD IN A SLIGHT CHANCE FOR RAIN SHOWERS IN
THOSE AREAS. NO MENTION OF THUNDER AT THE TIME AS THE INSTABILITY
LOOKS TOO WEAK BUT WILL KEEP AN EYE ON THINGS INTO THE AFTERNOON.
RED FLAG WARNING FOR SOUTHWEST NEBRASKA REMAINS TO LOOK ON TRACK
AS DRY AIR IS EXPECTED TO PUSH INTO THE AREA WITH WINDS INCREASING
AS THE BOUNDARY LAYER BECOMES FULLY MIXED TO AROUND 700MB THIS
AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT TUE MAR 24 2015
TODAY...THE UPPER TROUGH CURRENTLY ACROSS WRN SD AND THE WRN
PNHDL WILL PROGRESS EASTWARD TODAY. SHOWERS WILL DEVELOP TO THE
EAT OF THIS TROUGH...MAINLY EAST OF A BASSETT THROUGH BROKEN BOW
LINE BY 15Z. LIKELY POPS ACROSS PORTIONS OF
BOYD...HOLT...GARFIELD AND WHEELER COUNTY. THIS IN GOOD AGREEMENT
BY LATEST RAP13...HRRR AND 06Z NAM MODELS. A FEW SHOWERS MAY ALSO
DEVELOP ACROSS FAR NRN NEBR THIS AFTERNOON WITHIN AREA OF A VORT
MAX MOVING THROUGH THAT AREA. HIGHS TODAY REMAIN NEAR PREVIOUS
FORECAST REACHING THE LOW TO MID 60S MOST AREAS. EXCEPTION WILL
BE IN FAR EASTERN AREAS WHERE CONSIDERABLE CLOUDINESS AND SHOWERS
TO HOLD DOWN HIGHS TO THE MID 50S. A FAIRLY STRONG PV ANOMALY
EMERGING FROM NERN CO INTO SWRN NEBR AND NWRN KS THIS MORNING
LOOKS FAVORABLE FOR MIXING DOWN STRONGER WINDS TO THE SURFACE
ACROSS THE SERN PNHDL AND SWRN NEBR INTO THIS AFTERNOON.
NORTHWEST WINDS IN THESE AREAS ARE FORECAST TO INCREASE TO 25 TO
35 MPH THIS AFTERNOON. EXPOSED WHEAT FIELDS AND OTHER TILLED
GROUND WILL BE SUSCEPTIBLE TO BLOWING DUST...AND ADDED AREAS OF
BLOWING DUST THIS AFTERNOON. IN ADDITION...CRITICAL FIRE WEATHER
CONDITIONS MET IN PORTIONS OF SWRN NEBR WITH DETAILS HIGHLIGHTED
IN THE FIRE WEATHER DISCUSSION.
TONIGHT...INCREASING CLOUDINESS ACROSS WRN NEBR AS A DISTURBANCE
IN NERN WY WILL DROP SOUTHEAST INTO NRN NEBR AND FAR SRN SD WITH
A SLIGHT CHANCE FOR SHOWERS...WHICH IS SIMILAR TO PREVIOUS
FORECAST. LOWS TO FALL MOSTLY INTO THE LOWER 30S. AN ASSOCIATED
COLD FRONT WILL ALSO MOVE INTO WRN NEBR TONIGHT AS A CLOSED UPPER
LOW SWINGS FROM NORTH DAKOTA INTO NRN MINNESOTA. THIS WILL DROP
H85 TEMPS TO BELOW 0C ACROSS NCTRL NEBR OVERNIGHT. ACROSS THE
WEST COAST...A STRONG UPPER RIDGE WILL MOVE IN.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 335 AM CDT TUE MAR 24 2015
COLD FRONT WILL BE PUSHING SOUTH ACROSS THE STATE WED MORNING.
MOSTLY CLOUDY SKIES EARLY WILL GIVE WAY TO DECREASING CLOUDS FOR
THE AFTERNOON. MARGINAL ELEVATED LIFT EARLY...HOWEVER DRY
LOWER/MID LEVELS AND FAST MOVING CLIPPER SHOULD KEEP PRECIP FROM
REACHING THE GROUND AND FORECAST CONTINUES TO BE DRY. COLD
ADVECTION FOR THE DAY WITH AND A SLOW START TO WARM UP DUE TO
MORNING CLOUDS SHOULD RESULT IN A COOL DAY...COMPARED TO RECENT.
HIGHS IN THE UPPER 40S TO MID 50S...WHICH IS FAIRLY CLOSE TO
NORMAL.
THURSDAY NORTHWEST FLOW WILL BRING A CLIPPER THROUGH THE AREA.
AGAIN CONCERNS WITH LOW/MID LEVEL MOISTURE...HOWEVER MODELS
BRINGING SOME PACIFIC MOISTURE ROUNDING THE WESTERN RIDGE WHICH
COULD SATURATE TOP DOWN. ANOTHER CONCERN WILL BE TEMPS. MORNING
TEMPS BELOW FREEZING WHICH COULD RESULT IN PRECIP STARTING OUT AS
SNOW OR A RAIN/SNOW MIX AS CLOUDS INCREASE TEMPS INTO THE 30S. BY
THE AFTERNOON...EVEN WITH THE CLOUDS...MODEL INCREASING TEMPS
INTO THE 40S AND LOWER 50S. MAYBE OPTIMIST WITH TEMPS...HOWEVER
00Z GUIDANCE HAS ACTUALLY CAME IN WARMER. WONDERING IF THE LACK
OF MOISTURE IS BECOMING MORE OF AN ISSUE RESULTING IN MORE PEAKS
OF SUN AND THE ABILITY TO WARM MORE.
ANY LINGERING PRECIP WILL BE CONFINED TO THE HIGHER TERRAIN INTO
THURSDAY NIGHT. CLOUDS HELP KEEP TEMPS WARMER IN THE WEST. HIGH
PRESSURE BUILDS ACROSS THE UPPER MISS RVR VALLEY...NOSES INTO NE
NEB WITH SOME CLEARING AND TEMPS COOL INTO THE LOWER 20S FOR N
CENTRAL.
WARM FRONT TO LIFT ACROSS THE AREA FRIDAY. MODELS IN AGREEMENT
WITH A FASTER TREND OF THE WARM FRONT. THE GFS PRODUCES SOME WARM
ADVECT SHOWERS IN THE MORNING ACROSS PORTIONS OF N CENTRAL...BUT
ONCE AGAIN MOISTURE DEPRIVED LOWER LEVELS AND HAVE GONE DRY.
MAYBE A FEW SPRINKLES BUT DO NOT THINK IT IS WORTH MENTIONED NOW.
RIDGE EXPANDS FOR THE WEEKEND. TEMPS CLIMB WELL ABOVE NORMAL WITH
MOST AREAS AT OR ABOVE 70 FOR SAT. FAST MOVING PACIFIC COLD FRONT
OVERNIGHT SAT. ALTHOUGH A COLD FRONT...CLOUDS WILL LIKELY KEEP
TEMPS UP OVERNIGHT...NEAR 40. WILL MONITOR FOR POSSIBLE LIGHT
PRECIP...HOWEVER BEST LIFT TO THE NORTH WITH THE LATEST RUN.
CLEARING BEHIND THE FRONT WITH BREEZY CONDITIONS IN THE WAKE OF
THE FRONT ON SUNDAY AND WINDS HELP MIX THE BL AND TEMPS REBOUND
NICELY. CONTINUED MILD TO START NEXT WEEK AND DRY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 636 AM CDT TUE MAR 24 2015
VFR CONDITIONS THE NEXT 24 HRS AT THE KLBF AND KVTN TERMINALS. AN
UPPER TROUGH WILL EXIT THE REGION TODAY. NORTHWEST WINDS WILL
INCREASE BEHIND A COLD FRONT. THE STRONGER WINDS WILL OCCUR BY
THIS AFTERNOON AT KLBF WITH WINDS 30016G25KT. WINDS WILL DECOUPLE
BY EARLY THIS EVENING AS SKIES BECOME BROKEN IN MID AND HIGH
CLOUDINESS OVERNIGHT.
&&
.FIRE WEATHER...
ISSUED AT 335 AM CDT TUE MAR 24 2015
CRITICAL FIRE CONDITIONS ARE FORECAST ACROSS FIRE ZONES 210 AND
219 TODAY...WITH NEAR CRITICAL IN SOUTHERN PORTIONS OF 204 AND
206. STRONG NORTHWEST WINDS TO INCREASE TO 25 TO 35 MPH THIS
AFTERNOON ACROSS ZONES 210 AND 219 AS DEWPOINTS IN THESE AREAS
FALL TO 15 TO 20 AND HIGHS REACH THE MID 60S. THIS WILL BRING MIN
RH VALUES OF 12 TO 17 PERCENT. CONTINUATION OF RED FLAG WARNING
FOR ZONES 210 AND 219 IS WARRANTED WITH CLOSE MONITORING IN ZONES
204 AND 206.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR NEZ210-219.
&&
$$
UPDATE...BROOKS
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...ROBERG
FIRE WEATHER...ROBERG
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1034 AM CDT TUE MAR 24 2015
.UPDATE...NO CHANGES PLANNED TO HEADLINES AT THIS TIME. HAVE BEEN
POURING OVER THE PROGGD SOUNDINGS FROM THE RAP AND NAM. SURE HOPE
THE RAP IS THE CORRECT SOLUTION AS THE NAM IS SHOWING A RATHER
SIGNIFICANT ICING EVENT WITH SURFACE TEMPS DROPPING BELOW FREEZING
DURING PEAK PRECIP INTENSITY WITH MAX WARM LAYER OVERHEAD. HOWEVER
KEYING ON THE RAP AT THIS TIME WITH A SLOWER COOLING IN THE
BOUNDARY LAYER. EXPECTING SUSTAINED SE WINDS AND THE INCREASE IN
CLOUD COVER TO NEGATE THE USUAL EVENING DROPOFF. WILL BE WATCHING
THESE TEMP TRENDS CAREFULLY AS THE AFTERNOON WEARS ON. THE 850
MILLIBAR WARM SURGE WILL RAMP UP LATER THIS AFTERNOON AND INTO THE
EVENING HOURS. AT THIS TIME FEEL THE CURRENT HEADLINE IN THE FAR
NORTH LOOKS GOOD. WILL ALSO KEEP AN EYE ON THE FAR WESTERN
COUNTIES FOR SLEET/SNOW ACCUM POTENTIAL AS THERMAL TROUGH/DYNAMIC
COOLING HAS A SAY AS THE EVENT WEARS ON.
PC
&&
.AVIATION/18Z TAFS/...VFR MOSTLY SKC THIS AFTERNOON. MAIN MOISTURE
SURGE ARRIVES TONIGHT WITH STRENGTHENING LLJ. PRECIP PROGGD TO
ARRIVE 23-02Z...SW-NE ACROSS THE CWA. FOR THE EASTERN TAF SITES
BULK OF PRECIP EXPECTED TO BE RAIN WITH SOME MIX POTENTIAL DUE TO
DYNAMIC COOLING LATER IN THE NIGHT. BEST SNOW ACCUMS EXPECTED TO
THE NORTH OF TAF SITES. WILL BE CAREFULLY MONITORING BOUNDARY
CONDITIONS FOR PRECIP TYPE. ALL IN ALL GOING FCST ON TRACK. IFR
CIGS/LIFR CIGS LIKELY AS THE MAIN PRECIP AREA MOVES THROUGH
OVERNIGHT. DECENT CONSENSUS FROM THE NAM/GFS MOS AND LLVL RH
PROGS. PRECIP WINDS DOWN QUICKLY WEDNESDAY MORNING AS WESTERLY
FLOW AND SUBSIDENCE TAKE HOLD IN THE WAKE OF THE TROUGH.
PC
&&
.PREV DISCUSSION... /ISSUED 240 PM CDT TUE MAR 24 2015/
TONIGHT AND WEDNESDAY - FORECAST CONFIDENCE...
UNSEASONABLE WARMTH ACROSS SRN WI WILL BE REPLACED BY MORE NORMAL
MID MARCH TEMPERATURES AS A COLD FRONT SWEEPS THROUGH THE AREA THIS
EVENING. SURFACE LOW TO TRACK THROUGH SRN WI AND DRAG THE COLD FRONT
BY IN ITS WAKE. FRONT MAY GET HUNG UP A BIT WITHIN BAGGIER REGIME OF
THIS SOMEWHAT ELONGATED LOW. HOWEVER RAP/NAM SOUNDINGS CONTINUE TO
SUPPORT A WINDY AND CHILLER REGIME FOR MUCH OF THE NIGHT AFTER THE
EARLY/MID EVENING FROPA. WINDS HIGHEST IN THE EASTERN CWA WHERE
FAVORABLE ONSHORE FETCH AND FRICTIONLESS FLOW MEETS THE LAKESHORE
COUNTIES. SO EXPECTING A FAIRLY RAPID TEMP DROPOFF TO ANY AREAS THAT
HAVE NOT COOLED FROM THE PREFRONTAL LAKE BREEZE DEVELOPMENT. SOME OF
THE EARLIER SOUNDINGS FOR LAKESHORE AREAS RAISED CONCERN FOR A
POSSIBLE WIND ADVISORY BUT THERE HAS BEEN SOME BACKING OFF OF THAT
SO WILL NOT GO THAT ROUTE AT THIS TIME. WILL ALSO KEEP ANY EVENING
POPS CONFINED TO THE NORTH AND NORTHEAST PORTION OF THE CWA CLOSER
TO INFLUENCE OF UPPER JET INDUCED FORCING AND EXTRAP OF COLDER TOPS
ON IR SAT ANIMATION.
TUESDAY - CONFIDENCE...MEDIUM
500 MILLIBAR NVA BUILDS IN WITH SUSTAINED NW FLOW. SURFACE/850 RIDGE AXIS
REMAINS TO OUR WEST WHICH ALLOWS FOR PLENTY OF MIXING TO SUSTAIN A COOL
NW BREEZE. 925 TEMPS WILL BE DOWN NEAR 0C SO BACK MUCH CLOSER TO NORMAL
CONDITIONS....ALTHOUGH THE SUSTAINED WIND WILL GIVE IT A BELOW NORMAL FEEL.
TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE HIGH
TRANSIENT SURFACE HIGH MIGRATES SOUTHEASTWARD FROM THE NORTHERN
GREAT PLAINS TUESDAY NIGHT...AND INTO THE WESTERN GREAT LAKES REGION
ON WEDNESDAY. WITH NVA ALOFT AND SUBSIDENT MOTION...EXPECT CLEAR
SKIES EARLY TUESDAY NIGHT. CLOUDS WILL INCREASE INTO WEDNESDAY AHEAD
OF A WEAK SHORTWAVE IMPULSE...AS IT EJECTS SOUTHEASTWARD FROM THE
PACIFIC NORTHWEST/NORTHERN ROCKIES INTO THE NORTHERN PLAINS STATES
BY WEDNESDAY AFTERNOON. DRY CONDITIONS WILL PREVAIL FOR THE
PERIOD...WITH HIGHS IN THE 40S ON WEDNESDAY.
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE MEDIUM
LOW AMPLITUDE SHORTWAVE PROGRESSES EAST-SOUTHEASTWARD FROM THE
NORTHERN PLAINS WEDNESDAY NIGHT INTO THE LOWER GREAT LAKES REGION ON
FRIDAY. MODELS STILL SHOW A SWATH OF LIGHT PRECIPITATION ACROSS THE
AREA WEDNESDAY NIGHT...BUT FORCING IS LIMITED. KEPT LOW POPS FOR
THIS PERIOD WITH A RAIN-SNOW MIX POSSIBLE.
LONG TERM...THURSDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE
MEDIUM
WEAK SHORTWAVE ENERGY WILL CONTINUE ACROSS THE REGION...WITH A
CLOSED UPPER LOW EVOLVING OVER THE NORTHERN GREAT LAKES REGION ON
FRIDAY...BEFORE SHIFTING EAST INTO NEW ENGLAND ON SUNDAY. SLIGHT
CHANCE POPS ARE WARRENTED CWA-WIDE FOR THE THURSDAY NIGHT/FRIDAY
PERIOD AND AGAIN IN THE NE CWA ON FRIDAY NIGHT AND SATURDAY.
AVIATION/00Z TAFS/...SURFACE LOW VCNTY CNTRL WI CONTINUES TO SHIFT
EAST PER 3HR PRES FALLS. WARM ADVECTION REGIME AHEAD OF THE LOW
GENERATING PLENTY OF MID/HIGH LEVEL CLOUDINESS. THE LOW IS EXPECTED
TO TRACK TOWARDS NE IL/SE WI/SW LWR MI VCNTY BY 00Z. THIS WILL BRING
THE COLD FRONT SOUTH THIS EVENING WITH DECENT PUSH OF NNE WINDS
ASSOCIATED WITH POST FRONTAL PRESSURE RISES. STILL LOOKING AT A 01-02Z
WIND SHIFT AT KMKE TO A MORE NORTH/NORTHEAST DIRECTION. POST FRONTAL
EVENING STRATUS POTENTIAL LOOKS TRANSIENT AS DRYING NOTED AFTER 6Z.
PROGS SHOW DRY CONDITIONS AS HIGH PRESSURE WORKS INTO IA/MN REGION LATER
IN THE DAY. HOWEVER STILL A NW BREEZE TUESDAY WITH LINGERING PRESSURE
GRADIENT THOUGH NOT AS GUSTY.
MARINE...UPGRADED GALE WATCH TO GALE WARNING AND STAGGERED START
TIMES A BIT IN A NORTH/SOUTH FASHION TO ACCOUNT FOR THE SOUTHWARD
PROPAGATION OF GALE FORCE WINDS. UPSTREAM POST FRONTAL PRESSURE RISES
ACROSS MN SUPPORT THIS GALE EVENT WITH FAVORABLE NNE FETCH LEADING
TO A SIZABLE BUILDUP IN THE WAVE ACTION.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM CDT WEDNESDAY FOR
WIZ046-047-051-052.
LM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT
WEDNESDAY FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
WEDNESDAY THROUGH MONDAY...WOOD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
212 PM CDT TUE MAR 24 2015
.UPDATE...
1111 AM CDT
MADE MINOR ADJUSTMENT TO POP/WX TRENDS THROUGH THE
AFTERNOON...AS PRECIP TO THE WEST AND SOUTHWEST GRADUALLY
APPROACH. DELAYED THIS ARRIVAL TO MORE TOWARDS MID TO LATE
AFTERNOON AS PRECIP JUST TO THE SOUTH OF THE CWA SHIFTS EAST ALONG
MID LEVEL SHORTWAVE ENERGY...AND WITH PRECIP OVER SOUTHERN IOWA
DRIVEN BY A MORE VIGOROUS WAVE MOVES TOWARDS EASTERN IOWA. MOST
AREAS WONT LIKELY OBSERVE MORE WIDESPREAD PRECIP UNTIL LATER IN
THE EVENING AS LONGWAVE TROUGH HELPS PRECIP SHIELD REALLY EXPAND
NORTHWARD. SKIES THIS AFTERNOON WILL VARY FROM PARTLY CLOUDY TO
PARTLY SUNNY EARLY...BUT THEN BECOME CLOUDIER LATE THIS AFTERNOON
WITH THE ARRIVAL OF THICKER CLOUD SHIELD TO THE SOUTHWEST.
RODRIGUEZ
&&
.SHORT TERM...
249 AM CDT
THROUGH TONIGHT...
IR IMAGERY EARLY THIS MORNING INDICATED THE STRATUS LAYER HAS
PUSHED WEST OF THE CHICAGO AREA...HOWEVER A FEW POCKETS OF STRATUS
HAVE BEEN REDEVELOPING AND SLIDING ACROSS FAR NORTHEAST IL. TEMPS
ARE GENERALLY REMAINED IN THE UPR 20S EARLY THIS MORNING...WITH A
FEW LOCATIONS RADIATING INTO THE LOW 20S. A NARROW CHANNEL OF
CIRRUS WAS ALREADY STREAMING NORTHEAST FROM THE DEVELOPING
SHORTWAVE CURRENTLY CENTERED OVER THE CENTRAL PLAINS. THE GRADIENT
WILL REMAIN LIGHT THROUGH DAYBREAK...HOWEVER THE WEAK DIFFLUENT
FLOW WILL QUICKLY DISSIPATE AND MIXING WILL STEADILY INCREASE BY
MID-MORNING. GUIDANCE INDICATES SPEEDS THROUGH THE CHANNEL ARND
20KT.
THE MOIST AXIS DOES APPEAR TO BE SLIGHTLY SLOWER TO ARRIVE ACROSS
NORTHEAST IL UNTIL AFT 21Z...SO HAVE NUDGED TIMING BACK AN HOUR OR
TWO. COULD SEE PRECIP PUSHING INTO THE FAR SOUTHWEST CWFA ARND 18-
20Z...HOWEVER WITH THE WEAK DIFFLUENT FLOW LINGERING FURTHER
NORTH...THIS MAY HELP TO HOLD-OFF PRECIP UNTIL CLOSER TO 00Z. WITH A
STEADY CONVEYOR OF SLIGHTLY WARMER AIR ADVECTING NORTH THIS
AFTN...TEMPS ARE EXPECTED TO WARM TO ARND 40. THE CONCERN IS THAT
WITH THE FRESH SNOWPACK THIS MAY HOLD TEMPS DOWN A DEGREE OR TWO.
TONIGHT...
AS ELUDED TOO ABOVE...PRECIP WILL BE STEADILY INCREASING IN
COVERAGE THIS EVENING. BUT THE MAIN CONCERN FOR TONIGHT WILL
REVOLVE AROUND CONVECTION AND POSSIBLY SOME STRONGER EMBEDDED
THUNDERSTORMS. MID- LVL SHEAR IS IMPRESSIVE THIS EVENING...WITH
VALUES NEARING 40-50KTS. GIVEN THE RATHER MOIST PROFILE AND CLOUDY
ENVIRONMENT...CAPE VALUES WILL REMAIN MINIMAL. 0-3KM BULK SHEAR IS
EQUALLY IMPRESSIVE WITH THIS DYNAMIC NEGATIVELY TILTED SHORTWAVE
TONIGHT. THE SPC HAS THE AREAS SOUTH OF PONTIAC TO FOWLER IN A
MARGINAL RISK FOR SEVERE STORMS TONIGHT.
DEW POINTS WILL BE STEADILY INCREASING THIS EVENING AS WELL...AS
WARM AIR CONTINUES TO ADVECT NORTH. BY LATE THIS EVENING DEW POINTS
WILL BE APPROACHING THE LOW/MID 30S...AND POSSIBLY NEAR 40 ACROSS
THE FAR SOUTH. THEN OVERNIGHT DEW POINTS WILL CONTINUE TO RISE INTO
THE MID/UPR 30S NORTH...AND LOW 40S SOUTH. THIS SHOULD AID IN EATING
INTO THE SNOWPACK RATHER QUICKLY...COUPLED WITH THE RAIN AS WELL.
PWAT VALUES WILL BE NEARING 1 INCH LATE TONIGHT...AS THE MOISTURE
TRANSPORT CONTINUES TO FEED NORTH ACROSS THE FORECAST AREA. CURRENT
TRACK OF THE SHORTWAVE IS TO LIFT NORTHEAST ACROSS PONTIAC TO GARY
BY 9Z...WHICH SHUD HELP PUSH CONVECTIVE COVERAGE EAST/NORTHEAST BY
DAYBREAK WED.
BEACHLER
&&
.LONG TERM...
350 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
THE MAIN STORY DURING THE LONGER TERM PERIOD WILL BE THE AMPLIFYING
UPPER LEVEL FLOW PATTERN ACROSS NORTH AMERICA. UPPER LEVEL RIDGING
IS FORECAST TO BUILD OVER THE WESTERN CONUS IN RESPONSE TO THE
PROGRESSION A SIGNIFICANT DISTURBANCE OVER THE NORTHERN
PACIFIC...AND THIS WILL ULTIMATELY DRIVE SIGNIFICANT HEIGHT FALLS
AND TROUGHING OVER THE THE EASTERN HALF OF THE CONUS. AS A
RESULT...EXPECT TO TRANSITION BACK TO A PERIOD OF MUCH BELOW AVERAGE
TEMPERATURES LATE THIS WEEK INTO THE FIRST HALF OF THE WEEKEND.
THE PERIOD WILL START OUT MILD ON WEDNESDAY FOLLOWING THE PASSAGE OF
THE TUESDAY NIGHT STORM SYSTEM. IT DOES APPEAR THAT CLOUD COVER
COULD LINGER DURING THE DAY ON WEDNESDAY...AND THIS COULD LIMIT THE
AMOUNT OF WARMING WE EXPERIENCE DURING THE DAY. HOWEVER...WITH THE
COLDER AIRMASS NOT ARRIVING ACROSS THE AREA UNTIL LATER WEDNESDAY
NIGHT TEMPERATURES SHOULD BE ABLE TO CLIMB TO...AT LEAST...NEAR 50
DEGREES. AREAS SOUTH OF INTERSTATE 80 STAND THE BEST CHANCES TO
CLIMB WELL INTO THE 50S.
AS A COLD FRONT BEGINS TO SHIFT ACROSS NORTHERN ILLINOIS WEDNESDAY
NIGHT A WEAK SURFACE WAVE OF LOW PRESSURE IS EXPECTED TO DEVELOP
OVER THE SOUTHERN PLAINS...BEFORE QUICKLY SHIFTING NORTHEASTWARD
ALONG THE FRONT INTO THURSDAY MORNING. INCREASING FGEN ALONG THIS
FRONTAL WAVE SHOULD RESULT IN PRECIPITATION DEVELOPMENT WEDNESDAY
NIGHT...PRIMARILY ACROSS MY EAST CENTRAL ILLINOIS AND NORTHWESTERN
INDIANA COUNTIES. THIS ACTIVITY WILL SHIFT TO THE SOUTH AND EAST OF
MY AREA BY EARLY THURSDAY MORNING AS THE COLD FRONT CONTINUES TO
SHIFT SOUTHEASTWARD. DRY BUT COOLER WEATHER IN THE LOW TO 40S IS
EXPECTED FOR THE DAY THURSDAY.
ANOTHER STRONGER PUSH OF COLD AIR WILL ARRIVE OVER THE AREA BY
THURSDAY NIGHT INTO FRIDAY AS YET ANOTHER COLD FRONT SHIFTS OVER THE
AREA. STEEPENING LOW LEVEL LAPSE RATES OVER LAKE MICHIGAN WITH THIS
COLD AIR MASS COULD EVEN RESULT IN SOME LAKE EFFECT SNOW SHOWERS
ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA INTO FRIDAY
MORNING...AND THIS ACTIVITY LOOKS AS THOUGH IT COULD BE COMPLIMENTED
BY ANOTHER UPPER LEVEL PV ANOMALY DIGGING INTO THE BASE OF THE UPPER
LEVEL TROUGH OVER THE AREA. IF THIS SCENARIO PANS OUT AS CURRENTLY
FORECAST...THERE COULD BE SOME MINOR SNOW ACCUMULATIONS ACROSS
PORTIONS OF THE AREA WITH THIS ACTIVITY INTO FRIDAY.
WITH THE HEART OF THE COLD AIR MASS EXPECTED TO BE OVERHEAD ON
FRIDAY...IT LOOKS TO BE THE COLDEST DAY. HIGH TEMPERATURES ARE
CURRENTLY ONLY FORECAST TO GET INTO THE LOWER TO MID 30S...WHICH IS
A GOOD 15 TO 20 DEGREES BELOW AVERAGE. SURFACE HIGH PRESSURE SHOULD
BECOME CENTERED OVER OR NEAR THE AREA BY LATE FRIDAY NIGHT...SO THIS
SHOULD ALLOW TEMPERATURES FRIDAY NIGHT TO DROP INTO THE TEENS
INTO SATURDAY MORNING OUTSIDE OF CHICAGO.
AFTER ANOTHER WELL BELOW AVERAGE DAY ON SATURDAY...THINGS LOOKS TO
WARM BACK UP BY SUNDAY SURFACE RIDGE SHIFTS OVER THE SOUTHEASTERN
CONUS. IT APPEARS THAT SUNDAY COULD END UP NOT ONLY BEING A WARMER
DAY...WITH HIGHS POTENTIALLY WARMING BACK UP NEAR OR JUST ABOVE
AVERAGE...BUT ALSO A VERY BREEZY DAY. FORECAST GUIDANCE SUGGESTS
THAT A POTENT CLIPPER SYSTEM WILL TRACK EAST-SOUTHEASTWARD OVER
SOUTHERN ONTARIO...WHICH COULD SET UP A SURFACE GRADIENT SUPPORTIVE
OF SOME STRONG SOUTHWESTERLY WINDS. IN ADDITION...THE INCREASING WARM
AIR ADVECTON REGIME OVER THE AREA COULD ALSO RESULT IN THE
DEVELOPMENT OF SOME LIGHT RAIN SHOWERS DURING THE DAY.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* EAST WINDS AT 10-15 KT BECOMING SOUTHEAST WITH GUSTS UP TO 20
KT THIS EVE.
* SCATTERED SHOWERS AROUND 01Z WITH STEADY RAINFALL AND MVFR
PSBLY IFR VSBY ARRIVING ARND 4Z.
* IFR OR LOWER CIGS EXPECTED WITH STEADY RAIN OVERNIGHT.
* LLWS THIS EVE AND OVERNIGHT.
* GUSTY SOUTHWEST TO WEST WINDS TOMORROW.
JEE
//DISCUSSION...UPDATED 18Z...
THE NEXT LOW IS OVER NORTHEAST OKLAHOMA AND IT WILL MOVE OVER
NORTHEAST IL LATE TONIGHT INTO EARLY WEDNESDAY MORNING. RIGHT NOW
CLOUD COVER IS HAMPERING MIXING WITH ONLY A FEW SITES SHOWING
GUSTS UP TO 20 KT. MAY SEE A FEW OCNL GUSTS AT THE EASTERN
TERMINALS LATE THIS AFTN.
GUIDANCE KEEPS PUSHING BACK THE ARRIVAL TIME OF PRECIP THIS
EVENING...SO DID THE SAME IN THE TAFS. EXPECTING AN AREA OF
SCATTERED SHOWERS TO QUICKLY PASS OVER THE TERMINALS THIS
EVENING...WITH A BREAK IN PRECIP PSBL IN THE LATE EVENING. MORE
WIDESPREAD AND HEAVIER RAIN MOVES IN CLOSER TO MIDNIGHT. THE COMBO
OF WARMER AIR...RAIN...AND SNOW WILL LIKELY RESULT IN LOW END MVFR
TO HIGH END IFR VSBY AND CIGS. SOUTH TO SOUTHEAST WINDS WILL BE
GUSTING TO UP TO 25 KT OVERNIGHT WITH LLWS FORMING AS WELL.
GUIDANCE FEATURES 50KT WINDS JUST 2000 FT OFF OF THE DECK. CIGS
LOWER TO LIFR EARLY WEDNESDAY MORNING.
FOR THUNDER...THE BEST PARAMETERS FOR THUNDER REMAIN SOUTH OF THE
TERMINALS SO KEPT THUNDER OUT OF THE TAFS. CANNOT RULE OUT AN
ISOLATED EMBEDDED THUNDERSTORM AROUND THE TERMINALS...BUT AM
THINKING THE THUNDERSTORMS WILL BE TOO ISOLATED TO TRY TO CAPTURE
IN THE TAFS RIGHT NOW. TEMPERATURES SHOULD ALSO BE ABOVE FREEZING
SO NOT EXPECTING ANY FREEZING OR MIXED PRECIP.
PRECIP COMES TO AN END AS THE LOW SHIFTS NE OF THE AREA AND WINDS
BACK TO SW WITH GUSTS UP TO 25 KT BY MID WEDNESDAY MORNING. HAVE
LIMITED CONFIDENCE IN HOW QUICKLY CIGS IMPROVE TO MVFR AND THEN
EVENTUALLY VFR...AND THEY COULD IMPROVE SLOWER THAN INDICATED IN
THE FORECAST.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN RAIN...MEDIUM-HIGH CONFIDENCE IN TIMING.
* MEDIUM CONFIDENCE MAJORITY OF TS FORMING SOUTH OF THE
TERMINALS...LOW CONFIDENCE IN COVERAGE OF TS.
* HIGH CONFIDENCE IN LOWER CIGS...MEDIUM CONFIDENCE IN TIMING AND
HOW LOW THEY WILL BE.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WEST TO NORTHWEST WINDS. MAINLY VFR CONDS.
THURSDAY...CHANCE OF SNOW SHOWERS MAINLY IN THE EVENING. MVFR
POSSIBLE.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW EARLY. OTHERWISE PRIMARILY
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE OF RAIN. PATCHY MVFR POSSIBLE.
MONDAY...VFR.
BEACHLER
&&
.MARINE...
212 PM CDT
GENERALLY LIGHT EAST SOUTHEAST WINDS IN PLACE THIS AFTERNOON AS
HIGH PRESSURE IS SITUATED JUST TO THE EAST OF THE LAKE. TWO
SYSTEMS WILL MOVE EAST AND NORTHEAST TOWARDS LAKE MICHIGAN TONIGHT
WITH THE SOUTHERN SYSTEM HELPING TO INCREASE WINDS TO AROUND 30 KT
THIS EVENING. THE STRONGEST WINDS WILL LIKELY BE ACROSS THE
SOUTHERN HALF OF THE LAKE THIS EVENING INTO EARLY WEDNESDAY AS
THIS SYSTEM MOVES THROUGH THE SOUTHERN HALF OF THE LAKE. BOTH THE
NEARSHORE AND OPEN WATERS WILL BOTH OBSERVE THESE 30 KT
WINDS...WITH A PERIOD OF GALE FORCE GUSTS TO 35 KT STILL POSSIBLE
AS WELL. HAVE NOT ISSUED ANY GALE HEADLINES AT THIS TIME WITH THE
PREVAILING CONDITIONS APPEARING TO BE AROUND 30 KT AND WITH THE
DURATION OF THESE GALE FORCE GUSTS LIKELY REMAINING IN THE 4-6
HOUR TIME FRAME...BUT WILL CONTINUE TO MAKE MENTION OF THIS
POSSIBILITY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...7 PM TUESDAY TO 4 PM WEDNESDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
110 PM CDT Tue Mar 24 2015
.UPDATE...
ISSUED AT 1038 AM CDT TUE MAR 24 2015
High pressure sliding east as another low develops over the Plains
and moves into the Midwest later this evening. For now, a frontal
boundary not making much progress northward up into the region.
Between the slower approach of the front and the persistent cloud
cover, have pulled down todays highs. Would like to bring them
down further, but sat imagery starting to show some holes here and
there...and any clearing in the afternoon hours may allow for some
warming...but the highs for today will definitely wait until the
end of the day...with temps steady or climbing through the
overnight hours.
&&
.SHORT TERM...(Today)
ISSUED AT 329 AM CDT TUE MAR 24 2015
A band of mid-level warm frontogenesis will advance into central IL
from the west this morning, causing rain showers to eventually
develop through the dry low level airmass. The leading edge of the
rain band will likely encounter areas with surface temps at or just
below freezing, but not sure how far south will freezing rain
affect. 08z obs show only Jacksonville and Lawrenceville above
freezing, while the remainder of our C and SE IL obs at or below
freezing. Will need to include a mention of freezing rain a bit
farther south this morning as a result. Road surface temps on IDOT
sites showing road temps ranging from 34 to as low as 31F. We could
see some slippery road conditions develop with this initial rain
falling on dry pavement. Air temperatures should rise above freezing
across the board by 15z/10am, so any icing would melt quickly.
However, any ice on initially dry roads can be very slippery.
Will follow the HRRR depiction of rain advancing eastward in a band
that matches the current radar trends rather closely. Likely and
categorical PoPs this morning will be confined to the western
counties where low level saturation will occur the soonest.
The band of warm F-gen will gradually shift north this afternoon,
giving the precip a northward push as well. Have kept likely PoPs
across the northern half of our area through the afternoon.
Instability params support elevated thunderstorms today, generally
in the southwest half of our forecast area.
High temps today will be held in check by the cool east-northeast
flow that will persist through the day. Most areas will see the
mid-upper 40s this afternoon.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 329 AM CDT TUE MAR 24 2015
Deepening surface low pressure currently at 1006 mb over the OK
panhandle to eject ne into the IL river valley over central IL by
06Z/1 am tonight and then to southern part of Lake MI by 12Z/7 am
Wed and swing a cold front through central and eastern IL overnight.
Showers likely ahead of this front along with chances of
thunderstorms. SPC has marginal risk over much of central IL
(excluding Knox, Stark and Marshall counties) with slight risk of
severe storms this evening across central and sw MO from St Louis
southwest. Lows tonight range from upper 30s to near 40F over IL
river valley to upper 40s and lower 50s in southeast IL.
Central IL to be in between weather systems during the day Wed as low
pressure passes ne of the Great Lakes and another surface low
pressure organizes over the southern plains. Isolated showers and
thunderstorms to be possible later Wed afternoon south of I-72.
Milder highs Wed mostly in the 60s, ranging from around 60F from
Peoria north to upper 60s and lower 70s in southeast IL. 1007 mb low
pressure to track ne into far southern IL by 06Z/1 AM Wed night and
up the Ohio river to near the OH/KY border by dawn Thu. Models have
trended further south with this low pressure track, and SPC has
shifted slight risk of severe storms Wed night south of our CWA with
marginal risk into southeast counties along and south of I-70. Heavy
rains of 1-1.5 inches possible south of I-70 Wed night while rain
chances taper off to 20-30% nw of the IL river. Lows Wed night range
from mid 30s over IL river valley to 40-45F in southeast IL from I-70
southeast.
Lingered a chance of rain showers in southeast IL Thu morning then
low pressure moves into south-central PA by midday Thu and far enough
way to end rain chances Thu afternoon. Much cooler highs Thu in the
mid to upper 40s central IL and near 50F southeast IL. Even colder
Friday with highs in the upper 30s and lower 40s, coolest from I-74
ne. Models have been consistent in digging strong upper level trof
into the eastern states Thu/Fri bringing in the very cool
temperatures. 1030 mb Canadian high pressure settles into the Great
Lakes region Fri night and Sat with clouds and winds decreasing and
continued cold temps. Lows Fri night in the low to mid 20s. Highs
Sat in the low to mid 40s.
A cutoff upper level low passes north of the Great Lakes Sunday
keeping best chances of precipitation north of central IL, though
did carry small chances of light rain showers Sunday. Milder highs
Sunday and Monday in the mid to upper 50s with west central IL
around 60F.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 100 PM CDT TUE MAR 24 2015
Quasi stationary boundary at the surface just south of Central
Illinois terminals slow to move this afternoon, delaying the onset
of the MVFR/IFR stratus deck in PIA BMI and CMI. SPI BKN012
now...DEC soon to follow suit. Showers moving along SPI to DEC
path as well, with more rain to the west. Afternoon showers and
thunderstorms late remaining possible, though coverage anticipated
to be rather sparse...keeping the mention to VC since the warm
sector of the approaching low is delayed until after sunset.
Tightening pressure gradient however, will result in some rather
gusty winds after sunset/before midnight gusting to 30kts...mainly
out of the SE. IFR through the overnight hours. Clearing in the
morning with the llvl moisture trapped/enhanced may be delayed
considerably and since the operational models are not clearing
until closer to 16-18z...am holding off mention of improvement
just yet.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...Shimon
LONG TERM...07
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
110 PM CDT TUE MAR 24 2015
.UPDATE...
1111 AM CDT
MADE MINOR ADJUSTMENT TO POP/WX TRENDS THROUGH THE
AFTERNOON...AS PRECIP TO THE WEST AND SOUTHWEST GRADUALLY
APPROACH. DELAYED THIS ARRIVAL TO MORE TOWARDS MID TO LATE
AFTERNOON AS PRECIP JUST TO THE SOUTH OF THE CWA SHIFTS EAST ALONG
MID LEVEL SHORTWAVE ENERGY...AND WITH PRECIP OVER SOUTHERN IOWA
DRIVEN BY A MORE VIGOROUS WAVE MOVES TOWARDS EASTERN IOWA. MOST
AREAS WONT LIKELY OBSERVE MORE WIDESPREAD PRECIP UNTIL LATER IN
THE EVENING AS LONGWAVE TROUGH HELPS PRECIP SHIELD REALLY EXPAND
NORTHWARD. SKIES THIS AFTERNOON WILL VARY FROM PARTLY CLOUDY TO
PARTLY SUNNY EARLY...BUT THEN BECOME CLOUDIER LATE THIS AFTERNOON
WITH THE ARRIVAL OF THICKER CLOUD SHIELD TO THE SOUTHWEST.
RODRIGUEZ
&&
.SHORT TERM...
249 AM CDT
THROUGH TONIGHT...
IR IMAGERY EARLY THIS MORNING INDICATED THE STRATUS LAYER HAS
PUSHED WEST OF THE CHICAGO AREA...HOWEVER A FEW POCKETS OF STRATUS
HAVE BEEN REDEVELOPING AND SLIDING ACROSS FAR NORTHEAST IL. TEMPS
ARE GENERALLY REMAINED IN THE UPR 20S EARLY THIS MORNING...WITH A
FEW LOCATIONS RADIATING INTO THE LOW 20S. A NARROW CHANNEL OF
CIRRUS WAS ALREADY STREAMING NORTHEAST FROM THE DEVELOPING
SHORTWAVE CURRENTLY CENTERED OVER THE CENTRAL PLAINS. THE GRADIENT
WILL REMAIN LIGHT THROUGH DAYBREAK...HOWEVER THE WEAK DIFFLUENT
FLOW WILL QUICKLY DISSIPATE AND MIXING WILL STEADILY INCREASE BY
MID-MORNING. GUIDANCE INDICATES SPEEDS THROUGH THE CHANNEL ARND
20KT.
THE MOIST AXIS DOES APPEAR TO BE SLIGHTLY SLOWER TO ARRIVE ACROSS
NORTHEAST IL UNTIL AFT 21Z...SO HAVE NUDGED TIMING BACK AN HOUR OR
TWO. COULD SEE PRECIP PUSHING INTO THE FAR SOUTHWEST CWFA ARND 18-
20Z...HOWEVER WITH THE WEAK DIFFLUENT FLOW LINGERING FURTHER
NORTH...THIS MAY HELP TO HOLD-OFF PRECIP UNTIL CLOSER TO 00Z. WITH A
STEADY CONVEYOR OF SLIGHTLY WARMER AIR ADVECTING NORTH THIS
AFTN...TEMPS ARE EXPECTED TO WARM TO ARND 40. THE CONCERN IS THAT
WITH THE FRESH SNOWPACK THIS MAY HOLD TEMPS DOWN A DEGREE OR TWO.
TONIGHT...
AS ELUDED TOO ABOVE...PRECIP WILL BE STEADILY INCREASING IN
COVERAGE THIS EVENING. BUT THE MAIN CONCERN FOR TONIGHT WILL
REVOLVE AROUND CONVECTION AND POSSIBLY SOME STRONGER EMBEDDED
THUNDERSTORMS. MID- LVL SHEAR IS IMPRESSIVE THIS EVENING...WITH
VALUES NEARING 40-50KTS. GIVEN THE RATHER MOIST PROFILE AND CLOUDY
ENVIRONMENT...CAPE VALUES WILL REMAIN MINIMAL. 0-3KM BULK SHEAR IS
EQUALLY IMPRESSIVE WITH THIS DYNAMIC NEGATIVELY TILTED SHORTWAVE
TONIGHT. THE SPC HAS THE AREAS SOUTH OF PONTIAC TO FOWLER IN A
MARGINAL RISK FOR SEVERE STORMS TONIGHT.
DEW POINTS WILL BE STEADILY INCREASING THIS EVENING AS WELL...AS
WARM AIR CONTINUES TO ADVECT NORTH. BY LATE THIS EVENING DEW POINTS
WILL BE APPROACHING THE LOW/MID 30S...AND POSSIBLY NEAR 40 ACROSS
THE FAR SOUTH. THEN OVERNIGHT DEW POINTS WILL CONTINUE TO RISE INTO
THE MID/UPR 30S NORTH...AND LOW 40S SOUTH. THIS SHOULD AID IN EATING
INTO THE SNOWPACK RATHER QUICKLY...COUPLED WITH THE RAIN AS WELL.
PWAT VALUES WILL BE NEARING 1 INCH LATE TONIGHT...AS THE MOISTURE
TRANSPORT CONTINUES TO FEED NORTH ACROSS THE FORECAST AREA. CURRENT
TRACK OF THE SHORTWAVE IS TO LIFT NORTHEAST ACROSS PONTIAC TO GARY
BY 9Z...WHICH SHUD HELP PUSH CONVECTIVE COVERAGE EAST/NORTHEAST BY
DAYBREAK WED.
BEACHLER
&&
.LONG TERM...
350 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
THE MAIN STORY DURING THE LONGER TERM PERIOD WILL BE THE AMPLIFYING
UPPER LEVEL FLOW PATTERN ACROSS NORTH AMERICA. UPPER LEVEL RIDGING
IS FORECAST TO BUILD OVER THE WESTERN CONUS IN RESPONSE TO THE
PROGRESSION A SIGNIFICANT DISTURBANCE OVER THE NORTHERN
PACIFIC...AND THIS WILL ULTIMATELY DRIVE SIGNIFICANT HEIGHT FALLS
AND TROUGHING OVER THE THE EASTERN HALF OF THE CONUS. AS A
RESULT...EXPECT TO TRANSITION BACK TO A PERIOD OF MUCH BELOW AVERAGE
TEMPERATURES LATE THIS WEEK INTO THE FIRST HALF OF THE WEEKEND.
THE PERIOD WILL START OUT MILD ON WEDNESDAY FOLLOWING THE PASSAGE OF
THE TUESDAY NIGHT STORM SYSTEM. IT DOES APPEAR THAT CLOUD COVER
COULD LINGER DURING THE DAY ON WEDNESDAY...AND THIS COULD LIMIT THE
AMOUNT OF WARMING WE EXPERIENCE DURING THE DAY. HOWEVER...WITH THE
COLDER AIRMASS NOT ARRIVING ACROSS THE AREA UNTIL LATER WEDNESDAY
NIGHT TEMPERATURES SHOULD BE ABLE TO CLIMB TO...AT LEAST...NEAR 50
DEGREES. AREAS SOUTH OF INTERSTATE 80 STAND THE BEST CHANCES TO
CLIMB WELL INTO THE 50S.
AS A COLD FRONT BEGINS TO SHIFT ACROSS NORTHERN ILLINOIS WEDNESDAY
NIGHT A WEAK SURFACE WAVE OF LOW PRESSURE IS EXPECTED TO DEVELOP
OVER THE SOUTHERN PLAINS...BEFORE QUICKLY SHIFTING NORTHEASTWARD
ALONG THE FRONT INTO THURSDAY MORNING. INCREASING FGEN ALONG THIS
FRONTAL WAVE SHOULD RESULT IN PRECIPITATION DEVELOPMENT WEDNESDAY
NIGHT...PRIMARILY ACROSS MY EAST CENTRAL ILLINOIS AND NORTHWESTERN
INDIANA COUNTIES. THIS ACTIVITY WILL SHIFT TO THE SOUTH AND EAST OF
MY AREA BY EARLY THURSDAY MORNING AS THE COLD FRONT CONTINUES TO
SHIFT SOUTHEASTWARD. DRY BUT COOLER WEATHER IN THE LOW TO 40S IS
EXPECTED FOR THE DAY THURSDAY.
ANOTHER STRONGER PUSH OF COLD AIR WILL ARRIVE OVER THE AREA BY
THURSDAY NIGHT INTO FRIDAY AS YET ANOTHER COLD FRONT SHIFTS OVER THE
AREA. STEEPENING LOW LEVEL LAPSE RATES OVER LAKE MICHIGAN WITH THIS
COLD AIR MASS COULD EVEN RESULT IN SOME LAKE EFFECT SNOW SHOWERS
ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA INTO FRIDAY
MORNING...AND THIS ACTIVITY LOOKS AS THOUGH IT COULD BE COMPLIMENTED
BY ANOTHER UPPER LEVEL PV ANOMALY DIGGING INTO THE BASE OF THE UPPER
LEVEL TROUGH OVER THE AREA. IF THIS SCENARIO PANS OUT AS CURRENTLY
FORECAST...THERE COULD BE SOME MINOR SNOW ACCUMULATIONS ACROSS
PORTIONS OF THE AREA WITH THIS ACTIVITY INTO FRIDAY.
WITH THE HEART OF THE COLD AIR MASS EXPECTED TO BE OVERHEAD ON
FRIDAY...IT LOOKS TO BE THE COLDEST DAY. HIGH TEMPERATURES ARE
CURRENTLY ONLY FORECAST TO GET INTO THE LOWER TO MID 30S...WHICH IS
A GOOD 15 TO 20 DEGREES BELOW AVERAGE. SURFACE HIGH PRESSURE SHOULD
BECOME CENTERED OVER OR NEAR THE AREA BY LATE FRIDAY NIGHT...SO THIS
SHOULD ALLOW TEMPERATURES FRIDAY NIGHT TO DROP INTO THE TEENS
INTO SATURDAY MORNING OUTSIDE OF CHICAGO.
AFTER ANOTHER WELL BELOW AVERAGE DAY ON SATURDAY...THINGS LOOKS TO
WARM BACK UP BY SUNDAY SURFACE RIDGE SHIFTS OVER THE SOUTHEASTERN
CONUS. IT APPEARS THAT SUNDAY COULD END UP NOT ONLY BEING A WARMER
DAY...WITH HIGHS POTENTIALLY WARMING BACK UP NEAR OR JUST ABOVE
AVERAGE...BUT ALSO A VERY BREEZY DAY. FORECAST GUIDANCE SUGGESTS
THAT A POTENT CLIPPER SYSTEM WILL TRACK EAST-SOUTHEASTWARD OVER
SOUTHERN ONTARIO...WHICH COULD SET UP A SURFACE GRADIENT SUPPORTIVE
OF SOME STRONG SOUTHWESTERLY WINDS. IN ADDITION...THE INCREASING WARM
AIR ADVECTON REGIME OVER THE AREA COULD ALSO RESULT IN THE
DEVELOPMENT OF SOME LIGHT RAIN SHOWERS DURING THE DAY.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* EAST WINDS AT 10-15 KT BECOMING SOUTHEAST WITH GUSTS UP TO 20
KT THIS EVE.
* SCATTERED SHOWERS AROUND 01Z WITH STEADY RAINFALL AND MVFR
PSBLY IFR VSBY ARRIVING ARND 4Z.
* IFR OR LOWER CIGS EXPECTED WITH STEADY RAIN OVERNIGHT.
* LLWS THIS EVE AND OVERNIGHT.
* GUSTY SOUTHWEST TO WEST WINDS TOMORROW.
JEE
//DISCUSSION...UPDATED 18Z...
THE NEXT LOW IS OVER NORTHEAST OKLAHOMA AND IT WILL MOVE OVER
NORTHEAST IL LATE TONIGHT INTO EARLY WEDNESDAY MORNING. RIGHT NOW
CLOUD COVER IS HAMPERING MIXING WITH ONLY A FEW SITES SHOWING
GUSTS UP TO 20 KT. MAY SEE A FEW OCNL GUSTS AT THE EASTERN
TERMINALS LATE THIS AFTN.
GUIDANCE KEEPS PUSHING BACK THE ARRIVAL TIME OF PRECIP THIS
EVENING...SO DID THE SAME IN THE TAFS. EXPECTING AN AREA OF
SCATTERED SHOWERS TO QUICKLY PASS OVER THE TERMINALS THIS
EVENING...WITH A BREAK IN PRECIP PSBL IN THE LATE EVENING. MORE
WIDESPREAD AND HEAVIER RAIN MOVES IN CLOSER TO MIDNIGHT. THE COMBO
OF WARMER AIR...RAIN...AND SNOW WILL LIKELY RESULT IN LOW END MVFR
TO HIGH END IFR VSBY AND CIGS. SOUTH TO SOUTHEAST WINDS WILL BE
GUSTING TO UP TO 25 KT OVERNIGHT WITH LLWS FORMING AS WELL.
GUIDANCE FEATURES 50KT WINDS JUST 2000 FT OFF OF THE DECK. CIGS
LOWER TO LIFR EARLY WEDNESDAY MORNING.
FOR THUNDER...THE BEST PARAMETERS FOR THUNDER REMAIN SOUTH OF THE
TERMINALS SO KEPT THUNDER OUT OF THE TAFS. CANNOT RULE OUT AN
ISOLATED EMBEDDED THUNDERSTORM AROUND THE TERMINALS...BUT AM
THINKING THE THUNDERSTORMS WILL BE TOO ISOLATED TO TRY TO CAPTURE
IN THE TAFS RIGHT NOW. TEMPERATURES SHOULD ALSO BE ABOVE FREEZING
SO NOT EXPECTING ANY FREEZING OR MIXED PRECIP.
PRECIP COMES TO AN END AS THE LOW SHIFTS NE OF THE AREA AND WINDS
BACK TO SW WITH GUSTS UP TO 25 KT BY MID WEDNESDAY MORNING. HAVE
LIMITED CONFIDENCE IN HOW QUICKLY CIGS IMPROVE TO MVFR AND THEN
EVENTUALLY VFR...AND THEY COULD IMPROVE SLOWER THAN INDICATED IN
THE FORECAST.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN RAIN...MEDIUM-HIGH CONFIDENCE IN TIMING.
* MEDIUM CONFIDENCE MAJORITY OF TS FORMING SOUTH OF THE
TERMINALS...LOW CONFIDENCE IN COVERAGE OF TS.
* HIGH CONFIDENCE IN LOWER CIGS...MEDIUM CONFIDENCE IN TIMING AND
HOW LOW THEY WILL BE.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WEST TO NORTHWEST WINDS. MAINLY VFR CONDS.
THURSDAY...CHANCE OF SNOW SHOWERS MAINLY IN THE EVENING. MVFR
POSSIBLE.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW EARLY. OTHERWISE PRIMARILY
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE OF RAIN. PATCHY MVFR POSSIBLE.
MONDAY...VFR.
BEACHLER
&&
.MARINE...
409 AM CDT
WINDS WILL BEGIN TO INCREASE OUT OF THE SOUTHEAST OVER SOUTHERN LAKE
MICHIGAN THIS EVENING AS AN AREA OF LOW PRESSURE MOVES TOWARDS
NORTHERN ILLINOIS. IT NOW APPEARS THAT THE SURFACE LOW WILL TAKE A
TRACK RIGHT ACROSS SOUTHERN LAKE MICHIGAN LATE TONIGHT INTO EARLY
WEDNESDAY MORNING. THEREFORE...AS THE LOW MOVES OVER THE
LAKE...WINDS WILL LIKELY BECOME LIGHT AND VARIABLE FOR SHORT
PERIOD OVER FAR SOUTHERN LAKE MICHIGAN. WEST SOUTHWESTERLY WINDS
WILL ENSURE AS THE LOW SHIFTS OVER LOWER MICHIGAN WEDNESDAY
MORNING. WIND SPEEDS COULD APPROACH 25 TO 30 KT DURING THE
MORNING...BUT WIND SPEEDS SHOULD BE ON A DIMINISHING TREND THROUGH
THE DAY.
A COLD FRONT WILL SHIFT DOWN THE LAKE WEDNESDAY NIGHT...RESULTING IN
A NORTHERLY WIND SHIFT FOR THURSDAY. WINDS SPEEDS SHOULD ALSO
INCREASE UP TO 25 TO 30 KT BY THURSDAY EVENING AS THE SURFACE
GRADIENT TIGHTENS AHEAD OF AN AREA OF HIGH PRESSURE SHIFTING
SOUTHEASTWARD OVER THE UPPER MIDWEST. THIS SURFACE HIGH IS EXPECTED
TO SHIFT SOUTHEASTWARD OVER NORTHEASTERN ILLINOIS SATURDAY
MORNING...THEN SHIFT OVER THE SOUTHEASTERN CONUS BY SUNDAY. IT
APPEARS THAT ANOTHER SIGNIFICANT SOUTHERLY WIND EVENT COULD SET UP
FOR SUNDAY AS A POTENTIAL STORM SYSTEM TRACKS ACROSS SOUTHERN
ONTARIO.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...7 PM TUESDAY TO 4 PM WEDNESDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
110 PM CDT Tue Mar 24 2015
.UPDATE...
ISSUED AT 1038 AM CDT TUE MAR 24 2015
High pressure sliding east as another low develops over the Plains
and moves into the Midwest later this evening. For now, a frontal
boundary not making much progress northward up into the region.
Between the slower approach of the front and the persistent cloud
cover, have pulled down todays highs. Would like to bring them
down further, but sat imagery starting to show some holes here and
there...and any clearing in the afternoon hours may allow for some
warming...but the highs for today will definitely wait until the
end of the day...with temps steady or climbing through the
overnight hours.
&&
.SHORT TERM...(Today)
ISSUED AT 329 AM CDT TUE MAR 24 2015
A band of mid-level warm frontogenesis will advance into central IL
from the west this morning, causing rain showers to eventually
develop through the dry low level airmass. The leading edge of the
rain band will likely encounter areas with surface temps at or just
below freezing, but not sure how far south will freezing rain
affect. 08z obs show only Jacksonville and Lawrenceville above
freezing, while the remainder of our C and SE IL obs at or below
freezing. Will need to include a mention of freezing rain a bit
farther south this morning as a result. Road surface temps on IDOT
sites showing road temps ranging from 34 to as low as 31F. We could
see some slippery road conditions develop with this initial rain
falling on dry pavement. Air temperatures should rise above freezing
across the board by 15z/10am, so any icing would melt quickly.
However, any ice on initially dry roads can be very slippery.
Will follow the HRRR depiction of rain advancing eastward in a band
that matches the current radar trends rather closely. Likely and
categorical PoPs this morning will be confined to the western
counties where low level saturation will occur the soonest.
The band of warm F-gen will gradually shift north this afternoon,
giving the precip a northward push as well. Have kept likely PoPs
across the northern half of our area through the afternoon.
Instability params support elevated thunderstorms today, generally
in the southwest half of our forecast area.
High temps today will be held in check by the cool east-northeast
flow that will persist through the day. Most areas will see the
mid-upper 40s this afternoon.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 329 AM CDT TUE MAR 24 2015
Deepening surface low pressure currently at 1006 mb over the OK
panhandle to eject ne into the IL river valley over central IL by
06Z/1 am tonight and then to southern part of Lake MI by 12Z/7 am
Wed and swing a cold front through central and eastern IL overnight.
Showers likely ahead of this front along with chances of
thunderstorms. SPC has marginal risk over much of central IL
(excluding Knox, Stark and Marshall counties) with slight risk of
severe storms this evening across central and sw MO from St Louis
southwest. Lows tonight range from upper 30s to near 40F over IL
river valley to upper 40s and lower 50s in southeast IL.
Central IL to be in between weather systems during the day Wed as low
pressure passes ne of the Great Lakes and another surface low
pressure organizes over the southern plains. Isolated showers and
thunderstorms to be possible later Wed afternoon south of I-72.
Milder highs Wed mostly in the 60s, ranging from around 60F from
Peoria north to upper 60s and lower 70s in southeast IL. 1007 mb low
pressure to track ne into far southern IL by 06Z/1 AM Wed night and
up the Ohio river to near the OH/KY border by dawn Thu. Models have
trended further south with this low pressure track, and SPC has
shifted slight risk of severe storms Wed night south of our CWA with
marginal risk into southeast counties along and south of I-70. Heavy
rains of 1-1.5 inches possible south of I-70 Wed night while rain
chances taper off to 20-30% nw of the IL river. Lows Wed night range
from mid 30s over IL river valley to 40-45F in southeast IL from I-70
southeast.
Lingered a chance of rain showers in southeast IL Thu morning then
low pressure moves into south-central PA by midday Thu and far enough
way to end rain chances Thu afternoon. Much cooler highs Thu in the
mid to upper 40s central IL and near 50F southeast IL. Even colder
Friday with highs in the upper 30s and lower 40s, coolest from I-74
ne. Models have been consistent in digging strong upper level trof
into the eastern states Thu/Fri bringing in the very cool
temperatures. 1030 mb Canadian high pressure settles into the Great
Lakes region Fri night and Sat with clouds and winds decreasing and
continued cold temps. Lows Fri night in the low to mid 20s. Highs
Sat in the low to mid 40s.
A cutoff upper level low passes north of the Great Lakes Sunday
keeping best chances of precipitation north of central IL, though
did carry small chances of light rain showers Sunday. Milder highs
Sunday and Monday in the mid to upper 50s with west central IL
around 60F.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 100 PM CDT TUE MAR 24 2015
Quasi stationary boundary at the surface just south of Central
Illinois terminals slow to move this afternoon, delaying the onset
of the MVFR/IFR stratus deck in PIA BMI and CMI. SPI BKN012
now...DEC soon to follow suit. Showers moving along SPI to DEC
path as well, with more rain to the west. Afternoon showers and
thunderstorms late remaining possible, though coverage anticipated
to be rather sparse...keeping the mention to VC since the warm
sector of the approaching low is delayed until after sunset.
Tightening pressure gradient however, will result in some rather
gusty winds after sunset/before midnight gusting to 30kts...mainly
out of the SE. IFR through the overnight hours. Clearing in the
morning with the llvl moisture trapped/enhanced may be delayed
considerably and since the operational models are not clearing
until closer to 16-18z...am holding off mention of improvement
just yet.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...Shimon
LONG TERM...07
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
707 PM EDT Tue Mar 24 2015
...Updated Aviation Discussion...
...Forecast Update...
Issued at 601 PM EDT Tue Mar 24 2015
Have updated the grids early this evening to account for ongoing
trends. Convection continues to blossom in two areas early this
evening, one across MO/OK along a synoptic cold front, and another
over portions of southeast MO and southern IL in response to
increasing isentropic ascent and elevated instability atop a cool
airmass in place over the Ohio Valley. There has recently been a
report of dime sized hail with this latter activity across southeast
MO. The latest hi-res guidance shows this main elevated instability
axis remaining mainly off to the west through much of this evening,
so convection should continue to spark over southeast MO and western
KY and weaken as it moves away from the instability over southern IN
and central KY.
However, the latest RAP depicts this elevated instability axis
working into the southern IN and central KY later on this evening
into tonight as the low-level jet veers in response to a PV anomaly
ejecting out of the Central Plains. Therefore, have introduced
thunder into the forecast for late this evening into the overnight
hours, mainly across southern IN and extreme northern KY. Cannot
completely rule out some small hail, but think the more robust
updrafts capable of hail will remain off to the northwest.
Will continue to keep an eye on the second area of convection
currently across MO as it will approach the region toward dawn.
However, with the surface low passing well to the north, the focused
convergence which will be needed to make up for the loss of
instability will be passing to the north as well. Will continue to
keep up with trends this evening as things unfold.
.SHORT TERM (Now through Wednesday Night)...
Issued at 225 PM EDT Tue Mar 24 2015
Surface front is now a very slow-moving warm front draped across
south-central Kentucky. Isentropic lift is triggered an area of
light rain affecting southern Indiana, and just edging into the I-64
corridor in Kentucky. Temps range from the lower/mid 40s along and
north of I-64 to the 60s in south central Kentucky.
Still looking for the front to lift northward overnight. Low-level
jetting will kick up south of the front, with 900 mb winds
increasing to 50-55 kt. Precip chances initially confined to the
north will spread over the entire area as the night progresses, in
response to the front trying to wave back to the south by morning.
Will keep POPs in the chance category and QPF fairly light. Temp
curve is non-diurnal as we expect only a slight drop this evening,
and then rising temps before daybreak as the low-level jet creates
more of a mixy boundary layer.
Even though a surface wave will scoot past to our north Wednesday
morning, the front is oriented parallel to the flow aloft and will
really be left behind. Mid-level subsidence should provide a break
from any precip, so hourly POPs will be slight chance at best for
much of the day. Temps will depend heavily on how much lingering
cloud cover we have, and the current forecast of lower 70s is a
fairly conservative one. Places that get a decent amount of sunshine
could punch well into the 70s Wednesday afternoon.
Another wave will take shape over the southern Plains and lift ENE
through the Ohio Valley Wednesday night. Expect widespread precip
with embedded thunder. Strong mid-level winds through a deep layer
will not need a lot of help to mix down, which supports the marginal
svr wx threat advertised by SPC. The QPF could be fairly substantial
in places, as our current grids show rainfall in excess of 1 inch
during the night over southern Indiana. Short-fuse nuisance flooding
is possible under the heavier pockets of rain.
.LONG TERM (Thursday through Tuesday)...
Issued at 245 PM EDT Tue Mar 24 2015
The focus in the long term is on precipitation/temperature trends
Thursday then the unseasonably cold period Friday into this upcoming
weekend.
The synoptic pattern Thursday morning is expected to feature a
deepening and digging upper level trough through the Upper Midwest
into the Ohio Valley. At the surface, low pressure will likely be
tracking through southern Indiana into central Ohio with warmer,
moist air ahead. Highs Thursday will occur during the morning and
are are likely to be mild, in the mid 50s to low 60s. However, a
very strong cold front will cross through the forecast area over the
course of the day. 24.12z data still shows some minor timing
differences in how quickly the front passes, but overall, a
non-diurnal temperature trend is expected with readings falling into
the 40s by afternoon for much of the area.
Showers and elevated thunderstorms riding on the nose of the 850 mb
moisture transport will likely push across the area early Thursday
morning before moving off into Ohio. That leaves the post-frontal
rain showers and possibly a thunderstorm associated with the upper
level divergence within the right entrance region of the 130 kt jet.
There is some weak MUCAPE noted, on the order of 200-400 J/kg. The
upper level trough axis is expected to pass through Thursday night,
so expecting a quick shut off of precipitation west to east during
the evening. Rainfall amounts Thursday 1/3 to 1/2 of an inch look
reasonable.
Strong Canadian high pressure nosing down out of the northern Plains
will bring an anomalously cold air mass to the Ohio Valley for this
time of the year on Friday. With the deep upper trough overhead,
soundings show favorable, steep low level lapse rates of 7.5 to
8.5C/km with about 150-200mb of saturation. This could be enough to
spark scattered showers across the northern/eastern areas. Thermal
profiles would support a rain/snow/sleet pellet mix at times. Plan
on highs Friday to be stuck in the low to mid 40s with partly to
mostly cloudy skies and brisk northwest winds.
850 mb temps bottom out in the -8 to -11C range Friday night, or
about 3 standard deviations below normal. Not quite record territory
but lows Saturday morning likely to be in the low/mid 20s
regionwide. Would not be surprised if the colder, sheltered locations
fall into the mid/upper teens. Although the growing season hasn`t
fully taken off, those with agricultural interests or sensitive
vegetation should take note for the prolonged hard freezing
temperatures expected.
Below normal temperatures should continue through this upcoming
weekend as 850 mb temperatures climb slowly. The upper level flow
looks to remain northwesterly or zonal at best. A model consensus of
highs in the 40s Saturday then 50s Sunday look reasonable at this
time. 24.12z guidance showing another vigorous shortwave trough
coming down late Sunday or Monday that could reinforce colder
temperatures and bring a chance of precipitation to the area.
&&
.AVIATION (00Z TAF Update)...
Issued at 706 PM EDT Tue Mar 24 2015
Generally VFR conditions are expected through the period. A band of
precipitation continues to push into portions of southern IN and
northern KY, which will likely affect KSDF and KLEX this evening.
May briefly see vsbys drop to high-end MVFR in this activity, but
cigs should remain VFR.
Otherwise, this precipitation will lift northeast later on this
evening, but another line of showers and perhaps even a rumble of
thunder will push in overnight into the pre-dawn hours Wednesday.
The bulk of the precipitation should remain to the north of KSDF and
KLEX, but there may be just enough coverage to include VCSH wording.
High-end MVFR cigs are briefly possible Wednesday morning behind
this activity, before daytime mixing quickly raises bases to VFR.
Otherwise, after the morning precip chance at KSDF and KLEX, the
bulk of the day looks dry before more showers/storms move in
Wednesday night.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........KJD
Short Term.....RAS
Long Term......ZT
Aviation.......KJD
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
603 PM EDT Tue Mar 24 2015
...Forecast Update...
Issued at 601 PM EDT Tue Mar 24 2015
Have updated the grids early this evening to account for ongoing
trends. Convection continues to blossom in two areas early this
evening, one across MO/OK along a synoptic cold front, and another
over portions of southeast MO and southern IL in response to
increasing isentropic ascent and elevated instability atop a cool
airmass in place over the Ohio Valley. There has recently been a
report of dime sized hail with this latter activity across southeast
MO. The latest hi-res guidance shows this main elevated instability
axis remaining mainly off to the west through much of this evening,
so convection should continue to spark over southeast MO and western
KY and weaken as it moves away from the instability over southern IN
and central KY.
However, the latest RAP depicts this elevated instability axis
working into the southern IN and central KY later on this evening
into tonight as the low-level jet veers in response to a PV anomaly
ejecting out of the Central Plains. Therefore, have introduced
thunder into the forecast for late this evening into the overnight
hours, mainly across southern IN and extreme northern KY. Cannot
completely rule out some small hail, but think the more robust
updrafts capable of hail will remain off to the northwest.
Will continue to keep an eye on the second area of convection
currently across MO as it will approach the region toward dawn.
However, with the surface low passing well to the north, the focused
convergence which will be needed to make up for the loss of
instability will be passing to the north as well. Will continue to
keep up with trends this evening as things unfold.
.SHORT TERM (Now through Wednesday Night)...
Issued at 225 PM EDT Tue Mar 24 2015
Surface front is now a very slow-moving warm front draped across
south-central Kentucky. Isentropic lift is triggered an area of
light rain affecting southern Indiana, and just edging into the I-64
corridor in Kentucky. Temps range from the lower/mid 40s along and
north of I-64 to the 60s in south central Kentucky.
Still looking for the front to lift northward overnight. Low-level
jetting will kick up south of the front, with 900 mb winds
increasing to 50-55 kt. Precip chances initially confined to the
north will spread over the entire area as the night progresses, in
response to the front trying to wave back to the south by morning.
Will keep POPs in the chance category and QPF fairly light. Temp
curve is non-diurnal as we expect only a slight drop this evening,
and then rising temps before daybreak as the low-level jet creates
more of a mixy boundary layer.
Even though a surface wave will scoot past to our north Wednesday
morning, the front is oriented parallel to the flow aloft and will
really be left behind. Mid-level subsidence should provide a break
from any precip, so hourly POPs will be slight chance at best for
much of the day. Temps will depend heavily on how much lingering
cloud cover we have, and the current forecast of lower 70s is a
fairly conservative one. Places that get a decent amount of sunshine
could punch well into the 70s Wednesday afternoon.
Another wave will take shape over the southern Plains and lift ENE
through the Ohio Valley Wednesday night. Expect widespread precip
with embedded thunder. Strong mid-level winds through a deep layer
will not need a lot of help to mix down, which supports the marginal
svr wx threat advertised by SPC. The QPF could be fairly substantial
in places, as our current grids show rainfall in excess of 1 inch
during the night over southern Indiana. Short-fuse nuisance flooding
is possible under the heavier pockets of rain.
.LONG TERM (Thursday through Tuesday)...
Issued at 245 PM EDT Tue Mar 24 2015
The focus in the long term is on precipitation/temperature trends
Thursday then the unseasonably cold period Friday into this upcoming
weekend.
The synoptic pattern Thursday morning is expected to feature a
deepening and digging upper level trough through the Upper Midwest
into the Ohio Valley. At the surface, low pressure will likely be
tracking through southern Indiana into central Ohio with warmer,
moist air ahead. Highs Thursday will occur during the morning and
are are likely to be mild, in the mid 50s to low 60s. However, a
very strong cold front will cross through the forecast area over the
course of the day. 24.12z data still shows some minor timing
differences in how quickly the front passes, but overall, a
non-diurnal temperature trend is expected with readings falling into
the 40s by afternoon for much of the area.
Showers and elevated thunderstorms riding on the nose of the 850 mb
moisture transport will likely push across the area early Thursday
morning before moving off into Ohio. That leaves the post-frontal
rain showers and possibly a thunderstorm associated with the upper
level divergence within the right entrance region of the 130 kt jet.
There is some weak MUCAPE noted, on the order of 200-400 J/kg. The
upper level trough axis is expected to pass through Thursday night,
so expecting a quick shut off of precipitation west to east during
the evening. Rainfall amounts Thursday 1/3 to 1/2 of an inch look
reasonable.
Strong Canadian high pressure nosing down out of the northern Plains
will bring an anomalously cold air mass to the Ohio Valley for this
time of the year on Friday. With the deep upper trough overhead,
soundings show favorable, steep low level lapse rates of 7.5 to
8.5C/km with about 150-200mb of saturation. This could be enough to
spark scattered showers across the northern/eastern areas. Thermal
profiles would support a rain/snow/sleet pellet mix at times. Plan
on highs Friday to be stuck in the low to mid 40s with partly to
mostly cloudy skies and brisk northwest winds.
850 mb temps bottom out in the -8 to -11C range Friday night, or
about 3 standard deviations below normal. Not quite record territory
but lows Saturday morning likely to be in the low/mid 20s
regionwide. Would not be surprised if the colder, sheltered locations
fall into the mid/upper teens. Although the growing season hasn`t
fully taken off, those with agricultural interests or sensitive
vegetation should take note for the prolonged hard freezing
temperatures expected.
Below normal temperatures should continue through this upcoming
weekend as 850 mb temperatures climb slowly. The upper level flow
looks to remain northwesterly or zonal at best. A model consensus of
highs in the 40s Saturday then 50s Sunday look reasonable at this
time. 24.12z guidance showing another vigorous shortwave trough
coming down late Sunday or Monday that could reinforce colder
temperatures and bring a chance of precipitation to the area.
&&
.AVIATION (18Z TAF Update)...
Issued at 1250 PM EDT Tue Mar 24 2015
Quasi-stationary front is currently draped just south of BWG, but
VFR conditions prevail across central Kentucky. Spotty precip over
southern Illinois and Indiana, but conditions remain VFR as the
lower ceilings remain well north.
Expect a lowering of ceilings in SDF and LEX this afternoon as the
precip shield edges closer. Could see a lower deck but ceilings
should remain VFR. Any precip will be intermittent and VCSH should
cover it. BWG will remain dry and even a mid-level ceiling looks
like a worst case scenario there.
Front will lift northward overnight, with winds coming around to
southerly by daybreak. Small chances for precip as we get toward
sunrise but probabilities remain too low to mention.
Low-level jetting really cranks up out of the SW once the warm front
is through, but enough of that will mix down that we should see
surface winds pushing 15 kt, and would very likely stay out of any
LLWS mention. Jetting weakens and mixes out, so wind speeds should
stabilize at 10-12 kt for the remainder of the morning. MVFR
ceilings are quite possible but should stay above fuel-alternate.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........KJD
Short Term.....RAS
Long Term......ZT
Aviation.......RAS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
215 PM EDT TUE MAR 24 2015
.UPDATE...
ISSUED AT 215 PM EDT TUE MAR 24 2015
DID AN UPDATE TO THE GRIDS TO FINE TUNE POPS/SKY/WX THROUGH THE
REST OF THE AFTERNOON AND INTO THE EVENING. ALSO TWEAKED THE
MAXT...T...AND TD PER THE LATEST SHORTBLEND GUIDANCE...OBS...AND
TRENDS. THESE UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1115 AM EDT TUE MAR 24 2015
14Z SFC ANALYSIS SHOWS A STATIONARY FRONT LYING ACROSS KENTUCKY
AMIDST A TIGHT BAROCLINIC ZONE. AS SUCH...TEMPERATURES VARY WIDELY
ACROSS THE BOUNDARY FROM THE UPPER 30S AND LOWER 40S NORTHWEST TO
THE MID AND UPPER 50S IN THE SOUTHEAST. MID LEVEL CLOUDS HAVE
PUSHED BACK INTO THE AREA ALONG THE FRONT WHILE SOME LIGHT RAIN IN
FOUND THE NORTH OF THE BOUNDARY...GENERALLY ALONG AND NORTH OF
THE OHIO RIVER. DEWPOINTS RANGE FROM THE UPPER 20S IN THE
NORTHEAST PARTS OF THE CWA WHILE LOW 40S ARE FOUND NEAR THE
TENNESSEE BORDER. THE LATEST HRRR AND NAM12 SHOW PATCHES OF LIGHT
RAIN MOVING INTO THE NORTHERN PARTS OF THE AREA DURING THE
AFTERNOON AND INTO THE EVENING. HAVE ADJUSTED THE FORECAST TO
LIMIT ANY PCPN UNTIL AFTER 1 PM AND ALSO TO FINE TUNE SKY COVER
THROUGH THE FIRST PART OF THE EVENING. DID TWEAK THE MAXT...T...
AND TD GRIDS PER THE LATEST SHORTBLEND GUIDANCE...OBS...AND
TRENDS. UPDATED GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS
WITH A FRESHENED SET OF ZONES TO FOLLOW.
UPDATE ISSUED AT 824 AM EDT TUE MAR 24 2015
FRESHENED UP THE HOURLY TEMPERATURES...DEW POINTS AND SKY COVER TO
BETTER JIVE THE LATEST TRENDS IN OBSERVATIONS...OTHERWISE THE
FORECAST REMAINS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 409 AM EDT TUE MAR 24 2015
SURFACE HIGH PRESSURE IS CURRENTLY CENTERED ACROSS SOUTHEAST
CANADA...WITH LOW PRESSURE MOVING FROM THE FRONT RANGE OF THE
ROCKIES INTO THE HIGH PLAINS. A QUASI-STATIONARY FRONT EXTENDS
EAST FROM THE LOW...BECOMING MORE ILL-DEFINED CLOSER TO
TN/KY...ALTHOUGH THE TEMPERATURE GRADIENT IS PRETTY STOUT WITH
30S IN NORTHERN KY/SOUTHERN OH...AND 50S IN TENNESSEE. ALOFT...AN
UPPER LEVEL TROUGH IS MOVING THROUGH THE ROCKIES...WITH RIDGING
ACROSS THE PLAINS.
THE MODELS ARE IN GOOD AGREEMENT THAT A LEAD SHORT WAVE TROUGH
WILL EJECT OUT OF THE ROCKIES TROUGH AND BECOME NEGATIVELY TILTED
AS IT MOVES ACROSS THE PLAINS LATER TODAY...EVENTUALLY MOVING
INTO THE OHIO VALLEY/GREAT LAKES BY WEDNESDAY. THE SURFACE LOW
WILL FOLLOW SUIT...INITIALLY ALLOWING A WARM FRONT TO MOVE NORTH
INTO THE OHIO VALLEY LATER TONIGHT...BEFORE A COLD FRONT QUICKLY
FOLLOWS FOR WEDNESDAY...ALTHOUGH THE SOUTHERN PORTION OF THE FRONT
WILL BE WEAKENING AS THE UPPER LEVEL FORCING SAILS OFF TO THE
NORTH AND EAST.
FOR EASTERN KENTUCKY...TODAY WILL FEATURE QUITE A BIT OF VARIATION
WITH THE HIGH TEMPERATURES...AS LOCATIONS NORTH OF I-64 WILL
REMAIN CLOUDIER AND COOLER WITH READINGS IN THE LOW 50S...WHILE
SOME SUNSHINE AND SOUTHWEST FLOW HELP PUSH HIGHS TO AROUND 70
ALONG AND SOUTH OF THE HAL ROGERS AND HIGHWAY 80 CORRIDORS. A
MODEST LOW LEVEL JET NOSING IN FROM THE WEST WILL ALLOW FOR SOME
SHOWERS TO THREATEN...MAINLY NORTH OF THE MOUNTAIN PARKWAY THIS
AFTERNOON INTO EARLY THIS EVENING. A LULL IN THE POPS WILL OCCUR
LATER THIS EVENING AS THE WARM FRONT LIFTS NORTH...HOWEVER AS THE
COLD FRONT APPROACHES FROM THE WEST OVERNIGHT INTO
WEDNESDAY...POP CHANCES WILL INCREASE ONCE AGAIN...WITH HIGHER
VALUES NORTHWEST...AND LOWER ONES SOUTHEAST. ELEVATED INSTABILITY
OUT AHEAD OF THE COLD FRONT CONTINUES TO BE SHOWN IN THE
MODELS...SO WILL MAINTAIN SLIGHT CHANCES FOR THUNDER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 431 AM EDT TUE MAR 24 2015
WE BEGIN THE PERIOD WITH FIRST FRONTAL BOUNDARY AND LOW PRESSURE
SYSTEM PUSHING EAST AND NE OF THE REGION. RIGHT NOW THE GFS WANTS
TO KEEP QPF SIGNALS ALONG THE BAROCLINIC ZONE...HOWEVER IT SEEMS
TO BE THE ODD MODEL OUT AT THIS POINT. CONSEQUENTLY LEANED TOWARD
PREVIOUS FORECAST AND MODEL BLENDS FOR THIS PERIOD. THIS KEEPS
SLIGHT POPS IN BETWEEN THESE TWO UPPER LEVEL INDUCED SYSTEMS.
OPTED TO KEEP SLIGHT CHANCE THUNDER GIVEN REASONABLE ELEVATED
INSTABILITY IN PLACE. THE SECOND LOW PRESSURE WILL BEGIN FORMING
ACROSS THE CENTRAL PLAINS WEDNESDAY NIGHT AND WILL BE THE NEXT
MORE SUBSTANTIAL WEATHER MAKER IN THE PERIOD. THIS FEATURE WILL
MOVE NE ALONG THE BAROCLINIC ZONE AS LONG WAVE TROUGH PROGRESSES
EAST. EVENTUALLY SWINGING A STRONG COLD FRONT ACROSS THE REGION
THURSDAY. THIS WILL GIVE BEST CHANCES FOR POPS THROUGH THE PERIOD
WITH THUNDER POSSIBLE ALONG AND NEAR THE FRONT. ONCE AGAIN DECENT
INSTABILITY WITH LAPSE RATES AOA 6.5C PER KM EARLY ON THURSDAY
MAKES THIS SEEM REASONABLE. THINK THE THUNDER WILL DROP OFF
THROUGH THE DAY AS STRONG COLD FRONT WILL USHER IN COLDER AIR
BEHIND IT. THEREFORE DID OPT TO LEAN TOWARD A NON DIURNAL CURVE
THURSDAY WITH TEMPS DROPPING FROM NW TO SE THROUGH THE LATE
AFTERNOON. THIS FRONT WILL PROGRESS EAST THURSDAY NIGHT AND THE
BEST PRECIP CHANCES WILL GO WITH THE FRONT.
SOME QUESTIONS REMAIN FOR FRIDAY ON HOW MUCH MOISTURE WILL BE LEFT
OVER AS ENERGY ASSOCIATED WITH THE UPPER LEVEL TROUGH SWINGS
ACROSS THE OHIO VALLEY. DID LEAN TOWARD THE BLEND WHICH DOES KEEP
SLIGHT TO CHANCE POPS FROM SW TO NE. SOME SLIGHT CHANCE POPS
LINGER INTO FRIDAY NIGHT SUPPORTED BY THE GFS AND GEM. GIVEN THAT
FORECAST SOUNDINGS SUPPORT MIX TO SOME WET FLAKES HAVE
TRANSITIONED TO THIS OVERNIGHT. OTHERWISE IN THE WAKE OF THIS
STRONG COLD FRONT A CANADIAN HIGH IS FORECAST TO DROP SOUTHEAST.
THIS WILL SET THE STAGE FOR CLEARING SKIES AND MUCH COLDER TEMPS
ACROSS EASTERN KENTUCKY MOVING INTO THE WEEKEND. WHILE FRIDAY
NIGHT WILL FEATURE COLD TEMPERATURES WITH LOWS IN THE MID TO UPPER
20S. CLOUDS WILL SLOWLY CLEAR OUT OVERNIGHT AND THE HIGH WILL
STILL BE NOSING INTO THE REGION. SATURDAY WILL FEATURE SUNNY SKIES
AS DRIER AND COOLER AIR CONTINUE TO FILTER INTO THE REGION. BEST
CHANCE FOR RADIATIONAL COOLING AND CLEAR SKIES WILL BE SATURDAY
NIGHT...AS HIGH PRESSURE MOVES RIGHT OVER EASTERN KENTUCKY. THERE
IS STILL A FAIR AMOUNT OF UNCERTAINTY ON SURFACE HIGH
PLACEMENT...AND THESE TEMPS COULD NEED TO BE BUMPED DOWN FROM THE
LOW TO MID 20S THAT ARE IN THE GRIDS DEPENDING ON HOW THIS PLAYS
OUT. THIS AREA OF HIGH PRESSURE WILL SHIFT SE OF THE REGION SUNDAY
LEADING TO RETURN FLOW. HIGH TEMPS WILL BOUNCE BACK INTO THE LOW
TO MID 50S. MODELS BECOME QUITE DIVERGENT BY SUNDAY NIGHT INTO
MONDAY AS ANOTHER UPPER LEVEL WAVE DROPS SOUTHEAST. RIGHT NOW THE
GFS IS MUCH MORE PROGRESSIVE BRINGING A COLD FRONT SOUTH BY SUNDAY
NIGHT...WHILE THE ECMWF BRINGS THIS FEATURE DOWN LATER MONDAY.
STUCK WITH BLEND AT THIS POINT GIVEN THE GREATER UNCERTAINTY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 200 PM EDT TUE MAR 24 2015
VFR CONDITIONS WILL HOLD ON THROUGH MUCH OF THE PERIOD ACROSS THE
FORECAST AREA. A WARM FRONT IS TAKING SHAPE OVER THE NORTHERN
PARTS OF KENTUCKY...ALLOWING FOR SOME SHOWER ACTIVITY AS WELL AS
LOWER CEILINGS...THOUGH STILL VFR. THE BOUNDARY WILL EVENTUALLY
LIFT NORTH OF EASTERN KENTUCKY LATER TONIGHT...BEFORE A COLD FRONT
APPROACHES FROM THE WEST TOWARD DAWN WEDNESDAY MORNING...
THREATENING THE AREA WITH A BAND OF SHOWERS AND PERHAPS A
THUNDERSTORM. LIGHT AND VARIABLE WINDS WILL BECOME OUT OF SOUTH
AT 5 TO 10 KTS BETWEEN 08 AND 14Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
254 PM CDT TUE MAR 24 2015
.DISCUSSION...
DESPITE THE LEAD SHORTWAVE EJECTING OUT OF THE INTER MOUNTAIN
WEST INTO THE CENTRAL PLAINS...WELL NORTH OF OUR REGION...THERE IS
ENOUGH OF A WEAKNESS WITH THE TROUGH ACROSS THE SOUTHERN PLAINS
THAT WE ARE CLOSELY MONITORING POSSIBLE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS ACROSS EASTERN OKLAHOMA INTO WESTERN ARKANSAS THIS
AFTERNOON/EVENING.
VIS SATELLITE SHOWING A WELL DEFINED CU FIELD ACROSS N CENTRAL TX
INTO EASTERN OK/NW AR AHEAD OF A STRONG COLD FRONT WHICH AS OF 19Z
WAS LOCATED NEAR A BVO...SPS...ABI LINE. THIS FRONT WILL CONTINUE
TO SLOW AND WILL EVENTUALLY STALL JUST NORTHWEST OF OUR REGION
LATER THIS EVENING. MESOANALYSIS ACROSS THE SOUTHERN PLAINS IS
SHOWING CAPE VALUES NEAR 1000-1500 J/KG POOLING JUST AHEAD OF THE
FRONTAL BOUNDARY WITH LITTLE CINH REMAINING. DEEP LAYER SHEAR IS
ON THE ORDER OF MAGNITUDE OF 40-50KTS WITH MID LEVEL LAPSE RATES
AT OR NEAR 8 DEG/KM. LATEST RUNS OF THE HRRR AND NAM OUTPUT
SUGGESTS CONVECTION WILL LIKELY INITIATE BETWEEN 20-22Z ACROSS SW
MO...SE KS...NE OK...WITH THE CONVECTION BUILDING SOUTH AND WEST
ALONG THE COLD FRONT INTO SE OK. MCCURTAIN COUNTY MAY BE ON THE
SOUTHERN END OF ANY CONVECTION THAT CAN DEVELOP SOUTHWARD ALONG
THE BOUNDARY LATER THIS EVENING. SWOMCD IS CURRENTLY OUT FOR OUR
EXTREME NW ZONES AND A SEVERE THUNDERSTORM WATCH COULD BE ISSUED
FOR A FEW OF OUR NW COUNTIES LATER THIS AFTERNOON. CONVECTION
SHOULD WEAKEN QUICKLY AFTER MIDNIGHT IN COVERAGE AND INTENSITY
WITH STABILIZING EFFECTS OF THE BOUNDARY LAYER.
LOOKING AT A REPEAT SCENARIO FOR WEDNESDAY...EXCEPT ACROSS A
LARGER REGION OF THE SOUTHERN PLAINS BUT AGAIN...OUR REGION WILL
BE RIGHT ON THE EDGE OF STRONG TO SEVERE THUNDERSTORMS...MAINLY
ALONG AND NORTHWEST OF THE I-30 CORRIDOR WEDNESDAY EVENING. A
REINFORCING COLD FRONT ASSOCIATED WITH A LONGWAVE TROUGH WILL
EJECT OUT OF THE INTER MOUNTAIN WEST AND INTO THE PLAINS WED
NIGHT. THIS FRONT LOOKS TO PUSH COMPLETELY THROUGH OUR REGION LATE
WED NIGHT/THU TIME PERIOD BUT MUCH LIKE TONIGHT`S CONVECTION...WE
QUICKLY STABILIZE WED EVENING AS THE FRONT NEARS OUR REGION.
CANNOT RULE OUT SOME ISOLATED STRONG TO SEVERE THUNDERSTORMS
ACROSS OUR NW ZONES INITIALLY BUT AGREE WITH SPC`S DAYTWO OUTLOOK
KEEPING MORE WIDESPREAD ACTIVITY NORTH AND WEST OF OUR REGION
DUE TO STABILIZING EFFECTS AFTER SUNSET WED EVENING.
FRONT PUSHES SOUTHEAST OF OUR REGION QUICKLY ON THURSDAY TAKING
THE RAIN WITH IT. AMOUNTS LOOKING GENERALLY AROUND ONE QUARTER TO
ONE HALF INCH WITH THE EVENT...THUS SHOULD NOT RESULT IN MUCH IF
ANY IMPLICATIONS ON AREA RIVERS AND LAKES WHICH REMAIN HIGH ATTM.
IN THE WAKE OF THE TROUGH WED/THU...EXPANSIVE UPPER RIDGING WILL
DOMINATE THE WESTERN THIRD OF THE COUNTRY WITH A DRY NORTHWEST
FLOW COMMENCING FOR OUR REGION. MODELS CONTINUE TO WARM
TEMPERATURES FOR THE WEEKEND SO FOLLOWED THEIR LEAD CLOSELY. THE
RIDGE OUT WEST BEGINS TO BREAK DOWN EARLY NEXT WEEK AND WILL NEED
TO BE WATCHED FOR INCREASING MOISTURE AND RAIN CHANCES BY THE
EARLY TO MIDDLE PORTION OF NEXT WEEK.
PRELIMS TO FOLLOW...13.
&&
.PREV DISCUSSION... /ISSUED 108 PM CDT TUE MAR 24 2015/
AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH MUCH OF THE 18Z TAF
PD. MVFR STRATUS AND SOME PATCHY BR IS EXPECTED AT MOST SITES
BY 07Z-09Z...AND IS EXPECTED TO LIFT/SCATTER BY THE END OF THE PD.
OTHERWISE...EXPECT SOUTHERLY WINDS 8-12 KTS WITH HIGHER GUSTS
THROUGH THE AFTERNOON...DECREASING TO BETWEEN 5 AND 10 KTS
OVERNIGHT. /12/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 59 82 57 63 / 10 10 50 40
MLU 54 80 59 64 / 10 10 20 50
DEQ 56 79 49 62 / 40 20 70 30
TXK 59 80 53 62 / 20 20 60 30
ELD 56 78 57 63 / 20 10 50 50
TYR 60 81 53 62 / 10 10 60 30
GGG 59 82 55 63 / 10 10 60 30
LFK 59 84 58 66 / 10 10 30 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
12/13
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
428 PM EDT TUE MAR 24 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 427 PM EDT TUE MAR 24 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A COMPLEX OF SHORTWAVE
ENERGY FROM THE PACIFIC NW/NRN ROCKIES INTO THE PLAINS STATES. LEAD
ENERGY RESULTED IN CONVECTION ACROSS SRN MO/SRN IL TODAY. CLOSER TO
HOME...SHORTWAVE RIDGE OVER THE UPPER GREAT LAKES HAS ALLOWED SFC
HIGH PRES TO DOMINATE THE REGION TODAY. DRY AIR MASS/SUBSIDENCE
ASSOC WITH THE RIDGE HAS RESULTED SUNNY SKIES ACROSS THE UPPER LAKES
TODAY. WITH THE CENTER OF THE SFC HIGH WELL TO THE EAST...SSE WINDS
OFF LAKE MI HAVE RESULTED IN COOLER TEMPS (MAINLY IN THE 30S) OVER
THE EAST HALF OF THE CWA WHILE THE WARMEST TEMPS HAVE BEEN OVER THE
FAR WEST WHERE READINGS HAVE MANAGED TO REACH INTO THE MID TO UPPER
40S.
TONIGHT AND WEDNESDAY...ATTENTION TURNS TO THE MULTIPLE SHORTWAVES
CURRENTLY MOVING ACROSS THE PACIFIC NW AND WRN PLAINS. 12Z MODELS
STILL INDICATE LEAD ENERGY MOVING OUT ACROSS NE/KS THIS AFTN TAKING
ON A NEGATIVE TILT AS IT MOVES TO VCNTY OF SRN LAKE MI BY 12Z WED
WHILE ANOTHER SHORTWAVE MOVES ACROSS THE DAKOTAS INTO MN. THIS WILL
LEAD TO 2 SFC LOW CENTERS AT 12Z WED...ONE OVER NW MN AND THE SECOND
IN THE VCNTY OF SRN LAKE MI. FOR THE FCST AREA...THIS SHOULD
GENERALLY MEAN THAT THE HEAVIEST PCPN WOULD PASS BY TO THE SE OF
HERE...AND PCPN SHOULD FALL ALMOST EXCLUSIVELY AS SNOW AS IT ARRIVES
FROM THE S AND SW LATE TONIGHT. THERE IS STILL JUST ENOUGH
UNCERTAINTY IN THERMAL PROFILES (PARTICULARLY THE NAM...WHICH SHOWS
A FARTHER NORTH PLACEMENT OF SECONDARY SFC LOW THAN REST OF MODELS)
TO INCLUDE A MENTION OF -FZRA CLOSE TO LAKE MI AND FAR ERN PORTION
OF CWA AS ABOVE FREEZING TEMPS ALOFT COULD BRIEFLY NOSE INTO THE
AREA.
WILL CONTINUE TO UTILIZE MOSTLY A CONSENSUS APPROACH OF ALL AVBL
GUIDANCE TO CONSTRUCT POPS/QPF TONIGHT INTO WED. RESULT IS PCPN
SPREADING N AND NE INTO THE FCST AREA AFTER 06Z. IT`S POSSIBLE THE
SNOW MAY NOT ARRIVE OVER THE FAR N AND E FCST AREA UNTIL 12Z WED OR
AFTER. SHOULD BE LOOKING AT QPF RANGES FROM LESS THAN 0.10 INCH
NORTH TO 0.25 INCHES OVER SRN MNM COUNTY BY 12Z. AS NEG-TILT
SHORTWAVE CONTINUES TO LIFT NE ON WEDNESDAY...MODELS SHOW HEAVIEST
PCPN WILL LIFT INTO ERN COUNTIES OF THE CWA. MOST OF THE MODELS
PARTICUALRLY THE NAM AND REG-GEM SHOW A SECONDARY MAX OF PCPN OVER
NW MQT COUNTY AND THE HURON MOUNTAINS AREA LATE TONIGHT/WED MORNING
IN RESPONSE TO REGION OF ENHANCED MID-LVL FGEN/DEFORMATION SO HAVE
ALSO BUMPED UP QPF AMOUNTS OVER THIS AREA AS WELL. LOOKING AT TOTAL
QPF THROUGH THE EVENT...AMOUNTS GENERALLY RANGE FROM .30 INCH OR
MORE ALONG AND EAST OF A LINE FROM BIG BAY TO IRON MOUNTAIN...WITH
.25 INCH OR LESS WEST OF THIS LINE. VIGOROUS DYNAMICS AND HEALTHY
ISENTROPIC ASCENT NOTED ON 290K SFC SHOULD LEAD TO DECENT PCPN RATES
DURING PEAK FORCING WHICH REACHES THE WI BORDER IN THE 09Z-12Z TIME
FRAME. ALTHOUGH MIXING RATIOS OF 3-4G/KG ARE AVBL AROUND
750MB...SHORT DURATION OF STRONG FORCING (3-6 HRS) AND LOWER SNOW TO
WATER RATIOS DOWN TO AROUND 10 TO 1 MAKE FOR LOWER CONFIDENCE ON
SNOW ACCUMULATIONS REACHING ADVY LEVEL. QPF AMOUNTS COMBINED WITH
SLR OF 10:1 RESULTED IN MOST OF CENTRAL AND ERN CWA STAYING BTWN 2.5
TO 3 INCHES OF SNOW. SINCE SNOW AMOUNTS SHOULD STAY JUST BLO
ADVISORY FOR MUCH OF THE CENTRAL AND ERN CWA WILL JUST CONTINUE THE
SPS AND EXPAND TO INCLUDE MQT-BARAGA AND DICKINSON COUNTIES. WL
CONTINUE TO HIGHLIGHT POTENTIAL FOR MODERATE SNOW AND
SLUSHY/SLIPPERY ROADS DURING THE MORNING COMMUTE IN SPS.
SNOW WILL TAPER OFF QUICKLY FM WEST LATE MORNING/EARLY AFTERNOON AS
NEG-TILT SHORTWAVE QUICKLY MOVES EAST ALLOWIN FOR DRY SLOT TO MOVE
INTO UPPER MI. SOME WRAP AROUND MOISTURE ON BACKSIDE OF LOW COULD
ALLOW FOR LIGHT SNOW TO LINGER INTO THE AFTERNOON HRS OVER THE NW
CWA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 PM EDT TUE MAR 24 2015
THE FIRST WAVE OF PRECIPITATION WILL HAVE QUICKLY SHIFTED NORTHEAST
OF THE AREA ON WEDNESDAY...LEAVING THE TRAILING SHORTWAVE AND
SURFACE TROUGH STRETCHING SOUTHWEST ACROSS NORTHERN/WESTERN LAKE
SUPERIOR AT 00Z THURSDAY. EXPECT THERE TO BE SOME RAIN/SNOW SHOWERS
OCCURRING ALONG THIS TROUGH (WETBULB ZERO HEIGHTS SUPPORT A MIX
INITIALLY)...LARGELY OVER WESTERN LAKE SUPERIOR AND OVER THE
KEWEENAW. THE SURFACE-850MB TROUGH WILL THEN SLOWLY SINK SOUTHEAST
ACROSS UPPER MICHIGAN WEDNESDAY NIGHT...LEADING TO MUCH COLDER AIR
TO MOVE INTO THE AREA UNDER NORTHERLY FLOW. 850MB TEMPS WILL DROP
FROM -6C AT 00Z THURSDAY TO -11C BY 12Z AND -17C BY 00Z FRIDAY. THIS
COLDER AIR WILL LEAD TO ENHANCEMENT OF THE SNOW INITIALLY...BEFORE
TRANSITIONING TO PURE LAKE EFFECT DURING THE DAY ON THURSDAY AS THE
DEEPER MOISTURE DEPARTS. THE LOW LEVEL WINDS WILL BE VEERING THROUGH
THE WEDNESDAY NIGHT PERIOD (WESTERLY AT 00Z THURSDAY AND N-NNW BY
12Z THURSDAY)...LIMITING THE FOCUS OF THE TERRAIN ENHANCEMENT
INITIALLY WEDNESDAY EVENING. AS WINDS PERSIST OUT OF THE NORTHERLY
DIRECTION THROUGH THE DAY ON THURSDAY...THE TERRAIN ENHANCEMENT WILL
BECOME FOCUSED AND HAVE THE HIGHEST POPS IN THE NORTHERLY WIND
UPSLOPE AREAS DOWNWIND OF THE OPEN WATER ON LAKE SUPERIOR
(ESSENTIALLY AROUND GOGEBIC/ONTONAGON/MARQUETTE COUNTIES). WHILE
THIS WILL LEAD TO A FAVORABLE PERIOD OF LAKE ENHANCED AND UPSLOPE
SNOW WEDNESDAY NIGHT INTO THURSDAY MORNING...THE SNOW AMOUNTS WILL
DEPEND ON HOW QUICKLY WINDS VEER ON WEDNESDAY NIGHT. WILL FOLLOW THE
GENERAL CONSENSUS ON THE TIMING...WITH THE BEST LAKE ENHANCED QPF
OVER THE KEWEENAW IN THE EVENING AND SPREADING SOUTH TO
GOGEBIC/ONTONAGON/MARQUETTE/BARAGA COUNTIES DURING THE OVERNIGHT
HOURS. SNOW RATIOS WILL START UP AT OR BELOW 10-1 BEFORE TRENDING UP
DURING THE OVERNIGHT HOURS INTO THURSDAY AS THE COLD AIR SURGES INTO
THE AREA AND PUTS THE FOCUS OF THE FORCING CLOSER TO THE DGZ. ALL IN
ALL...HAVE SNOWFALL AMOUNTS WEDNESDAY NIGHT INTO THURSDAY OVER THOSE
PREVIOUSLY MENTIONED FAVORED AREAS OF 3 TO 6 INCHES (AND
POTENTIALLY UP TO 7 INCHES OVER THE PORKIES). IN ADDITION TO THE
SNOW...THE NORTHERLY WINDS WILL BE FAIRLY GUSTY ON THURSDAY
(25-30KTS AND SOME GALE FORCE GUSTS OVER CENTRAL LAKE
SUPERIOR)...WHICH WITH THE FLUFFIER NATURE OF THE SNOW BY THAT TIME
WILL LIKELY LEAD TO SOME BLOWING SNOW ALONG THE LAKE SUPERIOR
SHORELINES.
AS DRY AIR FROM THE CANADIAN HIGH PRESSURE IN MANITOBA NOSES INTO
WESTERN LAKE SUPERIOR ON THURSDAY AFTERNOON...EXPECT THE LAKE
EFFECT TO BEGIN TO DIMINISH AND WILL START LOWERING POPS DURING THE
AFTERNOON AND CONTINUE THE TREND INTO THURSDAY NIGHT. THERE DOES
APPEAR TO BE A FAVORABLE PERIOD OF THE CLOUD BEING WITHIN THE DGZ
LATE THURSDAY AFTERNOON INTO THURSDAY EVENING...WHICH WILL ATTEMPT
TO OFFSET THE DRIER AIR AND LOWERING INVERSION HEIGHTS...BUT DON/T
EXPECT THE ACCUMULATION TO BE TOO SIGNIFICANT (ADDITIONAL AMOUNTS
AROUND 1 INCH ON THURSDAY NIGHT).
AS THE HIGH CONTINUES SOUTH THROUGH MINNESOTA LATE THURSDAY NIGHT
AND INTO WISCONSIN FRIDAY AFTERNOON...A RIDGE WILL SLIDE ACROSS THE
UPPER GREAT LAKES REGION AND BRING AN END TO ANY LINGERING LAKE
EFFECT FRIDAY MORNING. DRY CONDITIONS WILL PERSIST THROUGH FRIDAY
NIGHT AND SATURDAY...AS THE RIDGE LINGERS OVER THE AREA AS THE HIGH
MOVES INTO THE SOUTHEAST CONUS. AFTER BELOW NORMAL TEMPERATURES ON
THURSDAY AND FRIDAY...SATURDAY/S TEMPERATURES WILL REBOUND TOWARDS
NORMAL.
FOCUS THEN TURNS TO A SHORTWAVE COMING ON SHORE IN THE PACIFIC
NORTHWEST FRIDAY NIGHT. THIS WAVE WILL MOVE EAST OVER THE CANADIAN
ROCKIES AND THEN EITHER THROUGH ONTARIO OR THE UPPER GREAT LAKES
REGION LATE SATURDAY NIGHT AND SUNDAY MORNING. OVERALL...MODELS
HAVE BEEN CONSISTENT ON THE TIMING OF THIS FEATURE...THEY JUST VARY
ON THE STRENGTH OF THE UPPER RIDGE OVER THE CENTRAL/SOUTHERN
ROCKIES. THE STRENGTH OF THAT RIDGE WILL DETERMINE IF THE WAVE
DIVES FARTHER SOUTH AND THROUGH THE REGION OR STAYS TO THE NORTH.
FEEL CONFIDENT ON THE TIMING TO SHOW MORE DETAIL IN THAT PORTION OF
THE FORECAST...BUT WILL KEEP POPS STILL IN THE HIGH CHANCE
CATEGORY. WILL KEEP PCPN IN THE FORECAST INTO SUNDAY AND EVEN
SUNDAY NIGHT...AS THERE ARE HINTS OF A SECONDARY WAVE SWEEPING
THROUGH THE AREA. THE PRECIP TYPE STILL IS A LITTLE UNCERTAIN...BUT
THE INITIAL WAVE SHOULD FALL AS SNOW AND THEN MIX WITH OR TURN TO
RAIN ON THE BACK SIDE. THAT POTENTIAL FOR RAIN WILL CONTINUE INTO
SUNDAY...BEFORE COLDER AIR MOVES BACK INTO THE REGION AND SWITCHES
ANY REMAINING PRECIPITATION BACK TO SNOW SUNDAY NIGHT.
THOSE SHORTWAVES WILL SHIFT EAST OF THE AREA SUNDAY NIGHT AND ALLOW
AN UPPER RIDGE TO NOSE EAST INTO THE UPPER GREAT LAKES REGION ON
MONDAY BEFORE FLATTENING ON TUESDAY. THIS WILL ALLOW FOR WARMER
AIR ALOFT TO WORK INTO THE AREA STARTING ON MONDAY AND ESPECIALLY
ON TUESDAY (925MB TEMPS RISING TO AT LEAST 6C). THAT SHOULD PUSH
HIGHS TO OR ABOVE 50 DEGREES FOR MUCH OF THE CWA FOR THE LAST DAY
OF MARCH (NORMAL IS 40-45). LOOKING FARTHER AHEAD...THE PATTERN
LOOKS TO TURN A LITTLE MORE ACTIVE FOR THE SECOND HALF OF NEXT
WEEK...AS THE MODELS REMAIN CONSISTENT ON A STRONGER WAVE MOVE EAST
TOWARDS THE GREAT LAKES REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 151 PM EDT TUE MAR 24 2015
VERY DRY AIR IN THE LOW TO MID LEVELS ASSOCIATED WITH HIGH PRES
MOVING E ACROSS THE LOWER GREAT LAKES TODAY WILL ENSURE VFR
CONDITIONS AT KIWD/KCMX/KSAW THROUGH THIS EVENING. LOW PRES LIFTING
NE TOWARD LAKE MICHIGAN TONIGHT WILL SPREAD SNOW INTO UPPER MI LATE
TONIGHT INTO WED MORNING. IFR CONDITIONS SHOULD REACH KIWD BY 10Z AND
KCMX BY 14Z AND THEN IMPROVE BACK UP TO MVFR BY LATE WED
MORNING/EARLY AFTERNOON. KSAW HAS BEST POTENTIAL FOR HEAVIER SNOW
CLOSER TO TRACK OF SFC LOW SO EXPECT CONDITIONS THERE TO LOWER TO
LIFR SHORTLY AFT 12Z AND THEN IMPROVE BACK TO MVFR BY 16Z AS SYSTEM
LIFTS QUICKLY E.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 PM EDT TUE MAR 24 2015
WINDS WILL REMAIN MOSTLY UNDER 20 KT TONIGHT INTO WED AS LOW PRES
TROF SETS UP ACROSS THE LAKE BTWN ONE LOW PRES CENTER MOVING E
TOWARD LAKE SUPERIOR AND THE OTHER LIFTING NE THRU LWR MI INTO
ONTARIO. THE TROF WILL DROP S OF THE LAKE WED NIGHT...AND WINDS WILL
THEN INCREASE INTO THU AS HIGH PRES BUILDS S TOWARD THE NRN PLAINS
AND MUCH COLDER AIR SPREADS SE INTO THE UPPER LAKES. NORTHERLY WINDS
SHOULD INCREASE TO 20-30KT LATE WED NIGHT INTO THU...AND IT`S NOT
OUT OF THE QUESTION THAT GALE FORCE GUSTS COULD OCCUR FOR A TIME
OVER CNTRL PORTIONS OF LAKE SUPERIOR. WINDS WILL THEN DIMINISH FRI
AS THE HIGH PRES ARRIVES OVER THE WRN GREAT LAKES. SW WINDS TO 25 KT
WILL BEGIN TO RAMP UP AGAIN LATE SAT INTO SUN MORNING AS THE HIGH
SHIFTS TO THE OHIO VALLEY AND LOW PRES DROPS SE FM MANITOBA TOWARD
THE UPPER GREAT LAKES. WINDS TO 25 KT WL SHIFT W-NW SUN AFTERNOON
BEHIND TROF PASSAGE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
339 PM EDT TUE MAR 24 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 557 AM EDT TUE MAR 24 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MESSY COMPLEX OF
SHORTWAVE ENERGY MOVING ACROSS THE PACIFIC NW AND ROCKIES. LEAD
ENERGY IS ALREADY GENERATING SHRA/TSRA ACROSS THE CNTRL PLAINS EARLY
THIS MORNING. CLOSER TO HOME...SHORTWAVE RIDGE OVER MN IS SUPPORTING
SFC HIGH PRES OVER THE GREAT LAKES. ASSOCIATED DRY AIR
MASS/SUBSIDENCE AHEAD OF RIDGE IS RESULTING IN CLEAR SKIES ACROSS
THE UPPER LAKES EARLY THIS MORNING. WITH LIGHT/CALM WIND...TEMPS IN
THE INTERIOR E HALF HAVE FALLEN INTO THE LOWER TEENS AND SINGLE
DIGITS WITH A FEW SPOTS RECENTLY NEAR 0F. OUT W...20S ARE MORE
COMMON WITH A LIGHT S WIND STIRRING.
MID/UPPER RIDGE SHIFTING ACROSS THE WRN GREAT LAKES TODAY ALONG WITH
DRY AIR MASS WILL RESULT IN ABUNDANT SUNSHINE. HIGH WILL REACH THE
40S OVER THE MUCH OF THE W HALF. S TO SE WINDS OFF LAKE MI WILL KEEP
THE E HALF COOLER IN THE 30S...PROBABLY LOW 30S NEAR THE SHORE OF
LAKE MI.
TONIGHT...ATTENTION TURNS TO THE MULTIPLE SHORTWAVES CURRENTLY
MOVING ACROSS THE PACIFIC NW AND ROCKIES. LEAD ENERGY MOVING OUT
ACROSS NE/KS THIS AFTN IS STILL FCST TO TAKE ON A NEGATIVE TILT AS
IT MOVES TO VCNTY OF SRN LAKE MI BY 12Z WED WHILE ANOTHER SHORTWAVE
MOVES ACROSS THE DAKOTAS INTO MN. THIS WILL LEAD TO 2 SFC LOW
CENTERS AT 12Z WED...ONE OVER NW MN AND THE SECOND IN THE VCNTY OF
SRN LAKE MI. OVER THE LAST FEW DAYS...MODELS HAVE PERSISTENTLY
OVERALL TRENDED SLIGHTLY SE WITH EACH SUCCESSIVE MODEL RUN IN REGARD
TO THE SRN SHORTWAVE/SFC LOW. THAT TREND HAS CONTINUED WITH THE 00Z
MODELS. FOR THE FCST AREA...THIS MEANS HEAVIEST PCPN SHOULD PASS BY
TO THE SE OF HERE...AND PCPN SHOULD FALL ALMOST EXCLUSIVELY AS SNOW
AS IT ARRIVES FROM THE S AND SW LATE TONIGHT. THERE IS STILL JUST
ENOUGH UNCERTAINTY IN THERMAL PROFILES TO INCLUDE A MENTION OF -FZRA
CLOSE TO LAKE MI WHERE WARM NOSE ALOFT OF ABOVE FREEZING TEMPS WILL
COME CLOSE TO THAT AREA. UTILIZED MOSTLY A CONSENSUS APPROACH OF ALL
AVBL GUIDANCE...WEIGHTED TOWARD HIGH RES GUIDANCE (NAM/GEM AND NCEP
HRW-ARW/NMM)...TO CONSTRUCT POPS/QPF TONIGHT. RESULT IS PCPN
SPREADING N AND NE INTO THE FCST AREA AFTER 06Z. IT`S POSSIBLE THE
SNOW MAY NOT ARRIVE OVER THE FAR N AND E FCST AREA UNTIL AROUND 12Z
WED. RESULT FOR QPF IS ROUGHLY 0.10 TO 0.25 INCHES BY 12Z...HIGHEST
IN SRN MENOMINEE COUNTY. VIGOROUS DYNAMICS AND HEALTHY ISENTROPIC
ASCENT NOTED ON 290K SFC SHOULD LEAD TO DECENT PCPN RATES DURING
PEAK FORCING WHICH REACHES THE WI BORDER IN THE 09Z-12Z TIME FRAME.
ALTHOUGH MIXING RATIOS OF 3-4G/KG ARE AVBL AROUND 750MB...SHORT
DURATION OF STRONG FORCING AND LOWER SNOW TO WATER RATIOS DOWN TO 10-
15 TO 1 MAKE FOR LOWER CONFIDENCE ON SNOW ACCUMULATIONS REACHING
ADVY LEVEL. AT THIS POINT...CONSENSUS HERE IS TO HOLD OFF ON ADVY
HEADLINES...ESPECIALLY SINCE THIS IS A VERY LATE 2ND PERIOD AND 3RD
PERIOD EVENT. IF NEXT ROUND OF MODEL RUNS TODAY PAINT A SLIGHTLY
HIGHER QPF PICTURE...CAN FORESEE ADVY HEADLINES FOR POSSIBLY THE E
HALF OF THE FCST AREA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 PM EDT TUE MAR 24 2015
THE FIRST WAVE OF PRECIPITATION WILL HAVE QUICKLY SHIFTED NORTHEAST
OF THE AREA ON WEDNESDAY...LEAVING THE TRAILING SHORTWAVE AND
SURFACE TROUGH STRETCHING SOUTHWEST ACROSS NORTHERN/WESTERN LAKE
SUPERIOR AT 00Z THURSDAY. EXPECT THERE TO BE SOME RAIN/SNOW SHOWERS
OCCURRING ALONG THIS TROUGH (WETBULB ZERO HEIGHTS SUPPORT A MIX
INITIALLY)...LARGELY OVER WESTERN LAKE SUPERIOR AND OVER THE
KEWEENAW. THE SURFACE-850MB TROUGH WILL THEN SLOWLY SINK SOUTHEAST
ACROSS UPPER MICHIGAN WEDNESDAY NIGHT...LEADING TO MUCH COLDER AIR
TO MOVE INTO THE AREA UNDER NORTHERLY FLOW. 850MB TEMPS WILL DROP
FROM -6C AT 00Z THURSDAY TO -11C BY 12Z AND -17C BY 00Z FRIDAY. THIS
COLDER AIR WILL LEAD TO ENHANCEMENT OF THE SNOW INITIALLY...BEFORE
TRANSITIONING TO PURE LAKE EFFECT DURING THE DAY ON THURSDAY AS THE
DEEPER MOISTURE DEPARTS. THE LOW LEVEL WINDS WILL BE VEERING THROUGH
THE WEDNESDAY NIGHT PERIOD (WESTERLY AT 00Z THURSDAY AND N-NNW BY
12Z THURSDAY)...LIMITING THE FOCUS OF THE TERRAIN ENHANCEMENT
INITIALLY WEDNESDAY EVENING. AS WINDS PERSIST OUT OF THE NORTHERLY
DIRECTION THROUGH THE DAY ON THURSDAY...THE TERRAIN ENHANCEMENT WILL
BECOME FOCUSED AND HAVE THE HIGHEST POPS IN THE NORTHERLY WIND
UPSLOPE AREAS DOWNWIND OF THE OPEN WATER ON LAKE SUPERIOR
(ESSENTIALLY AROUND GOGEBIC/ONTONAGON/MARQUETTE COUNTIES). WHILE
THIS WILL LEAD TO A FAVORABLE PERIOD OF LAKE ENHANCED AND UPSLOPE
SNOW WEDNESDAY NIGHT INTO THURSDAY MORNING...THE SNOW AMOUNTS WILL
DEPEND ON HOW QUICKLY WINDS VEER ON WEDNESDAY NIGHT. WILL FOLLOW THE
GENERAL CONSENSUS ON THE TIMING...WITH THE BEST LAKE ENHANCED QPF
OVER THE KEWEENAW IN THE EVENING AND SPREADING SOUTH TO
GOGEBIC/ONTONAGON/MARQUETTE/BARAGA COUNTIES DURING THE OVERNIGHT
HOURS. SNOW RATIOS WILL START UP AT OR BELOW 10-1 BEFORE TRENDING UP
DURING THE OVERNIGHT HOURS INTO THURSDAY AS THE COLD AIR SURGES INTO
THE AREA AND PUTS THE FOCUS OF THE FORCING CLOSER TO THE DGZ. ALL IN
ALL...HAVE SNOWFALL AMOUNTS WEDNESDAY NIGHT INTO THURSDAY OVER THOSE
PREVIOUSLY MENTIONED FAVORED AREAS OF 3 TO 6 INCHES (AND
POTENTIALLY UP TO 7 INCHES OVER THE PORKIES). IN ADDITION TO THE
SNOW...THE NORTHERLY WINDS WILL BE FAIRLY GUSTY ON THURSDAY
(25-30KTS AND SOME GALE FORCE GUSTS OVER CENTRAL LAKE
SUPERIOR)...WHICH WITH THE FLUFFIER NATURE OF THE SNOW BY THAT TIME
WILL LIKELY LEAD TO SOME BLOWING SNOW ALONG THE LAKE SUPERIOR
SHORELINES.
AS DRY AIR FROM THE CANADIAN HIGH PRESSURE IN MANITOBA NOSES INTO
WESTERN LAKE SUPERIOR ON THURSDAY AFTERNOON...EXPECT THE LAKE
EFFECT TO BEGIN TO DIMINISH AND WILL START LOWERING POPS DURING THE
AFTERNOON AND CONTINUE THE TREND INTO THURSDAY NIGHT. THERE DOES
APPEAR TO BE A FAVORABLE PERIOD OF THE CLOUD BEING WITHIN THE DGZ
LATE THURSDAY AFTERNOON INTO THURSDAY EVENING...WHICH WILL ATTEMPT
TO OFFSET THE DRIER AIR AND LOWERING INVERSION HEIGHTS...BUT DON/T
EXPECT THE ACCUMULATION TO BE TOO SIGNIFICANT (ADDITIONAL AMOUNTS
AROUND 1 INCH ON THURSDAY NIGHT).
AS THE HIGH CONTINUES SOUTH THROUGH MINNESOTA LATE THURSDAY NIGHT
AND INTO WISCONSIN FRIDAY AFTERNOON...A RIDGE WILL SLIDE ACROSS THE
UPPER GREAT LAKES REGION AND BRING AN END TO ANY LINGERING LAKE
EFFECT FRIDAY MORNING. DRY CONDITIONS WILL PERSIST THROUGH FRIDAY
NIGHT AND SATURDAY...AS THE RIDGE LINGERS OVER THE AREA AS THE HIGH
MOVES INTO THE SOUTHEAST CONUS. AFTER BELOW NORMAL TEMPERATURES ON
THURSDAY AND FRIDAY...SATURDAY/S TEMPERATURES WILL REBOUND TOWARDS
NORMAL.
FOCUS THEN TURNS TO A SHORTWAVE COMING ON SHORE IN THE PACIFIC
NORTHWEST FRIDAY NIGHT. THIS WAVE WILL MOVE EAST OVER THE CANADIAN
ROCKIES AND THEN EITHER THROUGH ONTARIO OR THE UPPER GREAT LAKES
REGION LATE SATURDAY NIGHT AND SUNDAY MORNING. OVERALL...MODELS
HAVE BEEN CONSISTENT ON THE TIMING OF THIS FEATURE...THEY JUST VARY
ON THE STRENGTH OF THE UPPER RIDGE OVER THE CENTRAL/SOUTHERN
ROCKIES. THE STRENGTH OF THAT RIDGE WILL DETERMINE IF THE WAVE
DIVES FARTHER SOUTH AND THROUGH THE REGION OR STAYS TO THE NORTH.
FEEL CONFIDENT ON THE TIMING TO SHOW MORE DETAIL IN THAT PORTION OF
THE FORECAST...BUT WILL KEEP POPS STILL IN THE HIGH CHANCE
CATEGORY. WILL KEEP PCPN IN THE FORECAST INTO SUNDAY AND EVEN
SUNDAY NIGHT...AS THERE ARE HINTS OF A SECONDARY WAVE SWEEPING
THROUGH THE AREA. THE PRECIP TYPE STILL IS A LITTLE UNCERTAIN...BUT
THE INITIAL WAVE SHOULD FALL AS SNOW AND THEN MIX WITH OR TURN TO
RAIN ON THE BACK SIDE. THAT POTENTIAL FOR RAIN WILL CONTINUE INTO
SUNDAY...BEFORE COLDER AIR MOVES BACK INTO THE REGION AND SWITCHES
ANY REMAINING PRECIPITATION BACK TO SNOW SUNDAY NIGHT.
THOSE SHORTWAVES WILL SHIFT EAST OF THE AREA SUNDAY NIGHT AND ALLOW
AN UPPER RIDGE TO NOSE EAST INTO THE UPPER GREAT LAKES REGION ON
MONDAY BEFORE FLATTENING ON TUESDAY. THIS WILL ALLOW FOR WARMER
AIR ALOFT TO WORK INTO THE AREA STARTING ON MONDAY AND ESPECIALLY
ON TUESDAY (925MB TEMPS RISING TO AT LEAST 6C). THAT SHOULD PUSH
HIGHS TO OR ABOVE 50 DEGREES FOR MUCH OF THE CWA FOR THE LAST DAY
OF MARCH (NORMAL IS 40-45). LOOKING FARTHER AHEAD...THE PATTERN
LOOKS TO TURN A LITTLE MORE ACTIVE FOR THE SECOND HALF OF NEXT
WEEK...AS THE MODELS REMAIN CONSISTENT ON A STRONGER WAVE MOVE EAST
TOWARDS THE GREAT LAKES REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 151 PM EDT TUE MAR 24 2015
VERY DRY AIR IN THE LOW TO MID LEVELS ASSOCIATED WITH HIGH PRES
MOVING E ACROSS THE LOWER GREAT LAKES TODAY WILL ENSURE VFR
CONDITIONS AT KIWD/KCMX/KSAW THROUGH THIS EVENING. LOW PRES LIFTING
NE TOWARD LAKE MICHIGAN TONIGHT WILL SPREAD SNOW INTO UPPER MI LATE
TONIGHT INTO WED MORNING. IFR CONDITIONS SHOULD REACH KIWD BY 10Z AND
KCMX BY 14Z AND THEN IMPROVE BACK UP TO MVFR BY LATE WED
MORNING/EARLY AFTERNOON. KSAW HAS BEST POTENTIAL FOR HEAVIER SNOW
CLOSER TO TRACK OF SFC LOW SO EXPECT CONDITIONS THERE TO LOWER TO
LIFR SHORTLY AFT 12Z AND THEN IMPROVE BACK TO MVFR BY 16Z AS SYSTEM
LIFTS QUICKLY E.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 557 AM EDT TUE MAR 24 2015
WITH HIGH PRES OVER THE GREAT LAKES REGION SHIFTING E WHILE LOW PRES
DEVELOPING OVER THE SRN PLAINS MOVES NE...WINDS WILL INCREASE TODAY
AND TONIGHT. SINCE PRES GRADIENT REMAINS RELATIVELY WEAK...WINDS
ACROSS LAKE SUPERIOR SHOULD REMAIN MOSTLY UNDER 20KT...THOUGH HIGH
OBS PLATFORMS WILL PROBABLY SEE SOME GUSTS TO AROUND 25KT. WINDS
WILL DIMINISH WED AS LOW PRES TROF SETS UP ACROSS THE LAKE BTWN ONE
LOW PRES CENTER MOVING E TOWARD LAKE SUPERIOR AND THE OTHER LIFTING
NE THRU LWR MI INTO ONTARIO. THE TROF WILL DROP S OF THE LAKE WED
NIGHT...AND WINDS WILL THEN INCREASE INTO THU AS HIGH PRES BUILDS S
TOWARD THE NRN PLAINS AND MUCH COLDER AIR SPREADS SE INTO THE UPPER
LAKES. NORTHERLY WINDS SHOULD INCREASE TO 20-30KT THU...AND IT`S NOT
OUT OF THE QUESTION THAT GALE FORCE GUSTS COULD OCCUR FOR A TIME
OVER CNTRL PORTIONS OF LAKE SUPERIOR. WINDS WILL THEN DIMINISH FRI
AS THE HIGH PRES ARRIVES OVER THE WRN GREAT LAKES. WIND WILL BEGIN
TO RAMP UP AGAIN SAT...ESPECIALLY LATE...AS THE HIGH SHIFTS TO THE
OHIO VALLEY AND LOW PRES DROPS SE INTO MANITOBA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
159 PM EDT TUE MAR 24 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 557 AM EDT TUE MAR 24 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MESSY COMPLEX OF
SHORTWAVE ENERGY MOVING ACROSS THE PACIFIC NW AND ROCKIES. LEAD
ENERGY IS ALREADY GENERATING SHRA/TSRA ACROSS THE CNTRL PLAINS EARLY
THIS MORNING. CLOSER TO HOME...SHORTWAVE RIDGE OVER MN IS SUPPORTING
SFC HIGH PRES OVER THE GREAT LAKES. ASSOCIATED DRY AIR
MASS/SUBSIDENCE AHEAD OF RIDGE IS RESULTING IN CLEAR SKIES ACROSS
THE UPPER LAKES EARLY THIS MORNING. WITH LIGHT/CALM WIND...TEMPS IN
THE INTERIOR E HALF HAVE FALLEN INTO THE LOWER TEENS AND SINGLE
DIGITS WITH A FEW SPOTS RECENTLY NEAR 0F. OUT W...20S ARE MORE
COMMON WITH A LIGHT S WIND STIRRING.
MID/UPPER RIDGE SHIFTING ACROSS THE WRN GREAT LAKES TODAY ALONG WITH
DRY AIR MASS WILL RESULT IN ABUNDANT SUNSHINE. HIGH WILL REACH THE
40S OVER THE MUCH OF THE W HALF. S TO SE WINDS OFF LAKE MI WILL KEEP
THE E HALF COOLER IN THE 30S...PROBABLY LOW 30S NEAR THE SHORE OF
LAKE MI.
TONIGHT...ATTENTION TURNS TO THE MULTIPLE SHORTWAVES CURRENTLY
MOVING ACROSS THE PACIFIC NW AND ROCKIES. LEAD ENERGY MOVING OUT
ACROSS NE/KS THIS AFTN IS STILL FCST TO TAKE ON A NEGATIVE TILT AS
IT MOVES TO VCNTY OF SRN LAKE MI BY 12Z WED WHILE ANOTHER SHORTWAVE
MOVES ACROSS THE DAKOTAS INTO MN. THIS WILL LEAD TO 2 SFC LOW
CENTERS AT 12Z WED...ONE OVER NW MN AND THE SECOND IN THE VCNTY OF
SRN LAKE MI. OVER THE LAST FEW DAYS...MODELS HAVE PERSISTENTLY
OVERALL TRENDED SLIGHTLY SE WITH EACH SUCCESSIVE MODEL RUN IN REGARD
TO THE SRN SHORTWAVE/SFC LOW. THAT TREND HAS CONTINUED WITH THE 00Z
MODELS. FOR THE FCST AREA...THIS MEANS HEAVIEST PCPN SHOULD PASS BY
TO THE SE OF HERE...AND PCPN SHOULD FALL ALMOST EXCLUSIVELY AS SNOW
AS IT ARRIVES FROM THE S AND SW LATE TONIGHT. THERE IS STILL JUST
ENOUGH UNCERTAINTY IN THERMAL PROFILES TO INCLUDE A MENTION OF -FZRA
CLOSE TO LAKE MI WHERE WARM NOSE ALOFT OF ABOVE FREEZING TEMPS WILL
COME CLOSE TO THAT AREA. UTILIZED MOSTLY A CONSENSUS APPROACH OF ALL
AVBL GUIDANCE...WEIGHTED TOWARD HIGH RES GUIDANCE (NAM/GEM AND NCEP
HRW-ARW/NMM)...TO CONSTRUCT POPS/QPF TONIGHT. RESULT IS PCPN
SPREADING N AND NE INTO THE FCST AREA AFTER 06Z. IT`S POSSIBLE THE
SNOW MAY NOT ARRIVE OVER THE FAR N AND E FCST AREA UNTIL AROUND 12Z
WED. RESULT FOR QPF IS ROUGHLY 0.10 TO 0.25 INCHES BY 12Z...HIGHEST
IN SRN MENOMINEE COUNTY. VIGOROUS DYNAMICS AND HEALTHY ISENTROPIC
ASCENT NOTED ON 290K SFC SHOULD LEAD TO DECENT PCPN RATES DURING
PEAK FORCING WHICH REACHES THE WI BORDER IN THE 09Z-12Z TIME FRAME.
ALTHOUGH MIXING RATIOS OF 3-4G/KG ARE AVBL AROUND 750MB...SHORT
DURATION OF STRONG FORCING AND LOWER SNOW TO WATER RATIOS DOWN TO 10-
15 TO 1 MAKE FOR LOWER CONFIDENCE ON SNOW ACCUMULATIONS REACHING
ADVY LEVEL. AT THIS POINT...CONSENSUS HERE IS TO HOLD OFF ON ADVY
HEADLINES...ESPECIALLY SINCE THIS IS A VERY LATE 2ND PERIOD AND 3RD
PERIOD EVENT. IF NEXT ROUND OF MODEL RUNS TODAY PAINT A SLIGHTLY
HIGHER QPF PICTURE...CAN FORESEE ADVY HEADLINES FOR POSSIBLY THE E
HALF OF THE FCST AREA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 517 AM EDT TUE MAR 24 2015
FCST MODELS CONTINUE TO MERGE ON A THEME OF HAVING THE INITIAL LOW
FROM THE SW OVER CENTRAL LAKE MI AROUND 12Z WEDNESDAY. THE RESULT
HAS BEEN A TREND TO LESS PRECIP AND MORE IN THE FORM OF SNOW INSTEAD
OF FREEZING RAIN WEDNESDAY MORNING.
PRECIP WILL OVERSPREAD THE REST OF THE CWA WEDNESDAY MORNING. THIS
QUICK BLAST OF MOISTURE WILL ALREADY BE PULLING OUT OF THE SW CORNER
OF UPPER MI BY 18Z WEDNESDAY...AND IF THE 23/18Z RUN OF THE CANADIAN
IS CORRECT MUCH OF THE SW AND CENTRAL CWA. THIS WILL BE WHILE THE
SFC LOW SHIFTS ACROSS E UPPER MI AND NW LAKE HURON BY 18Z...AND
GENERALLY BETWEEN CYLD AND CYXR IN SE ONTARIO BY 00Z THURSDAY. WITH
SFC TEMPS GETTING INTO THE UPPER 30S AND LOW 40S WEDNESDAY
AFTERNOON...SNOW WILL BE DIFFICULT TO MAINTAIN. WHILE A MIX IS
REPRESENTED IN THE FCST...UPPER MI WILL BE IN A LULL...WITH MUCH OF
THE BEST MOISTURE WILL BE ALREADY GONE.
UPDATED THE SPS TO INCLUDE THE COUNTIES OF MENOMINEE TO ALGER AND
E...WHERE THE GREATEST POTENTIAL FOR OVER 2IN OF SNOW EXISTS...ALONG
WITH A BRIEF PERIOD OF FREEZING RAIN.
WILL NEED TO WAIT UNTIL THE SECONDARY SFC LOW /OVER NW MN AT 12Z
WEDNESDAY/ EXITS THE PICTURE. IT SHOULD MOVE OVER NE MN AT 18Z
WEDNEDAY...AND JOIN FORCES WITH THE MAIN LOW EARLY WEDNESDAY EVENING
OVER LAKE SUPERIOR AND SE ONTARIO. 850MB TEMPS STILL AROUND -5C AT
00Z THURSDAY WILL FALL TO AROUND -15C OVER THE W BY 12Z THURSDAY ON
N-NW WINDS. THE RESULT...WITH THE ASSISTANCE OF THE SIZABLE 500MB
TROUGH OVERHEAD CONTINUING TO BRING A SERIES OF SHORTWAVES ACROSS
UPPER MI...WILL BE LIGHT TO AT TIMES MODERATE LES THROUGH THURSDAY
EVENING.
THE 500MB TROUGH WILL EVENTUALLY SHIFT TO OUR SE...MAKING WAY FOR A
RIDGE SATURDAY INTO EARLY SUNDAY. AT THIS POINT...WITH HIGH PRESSURE
AT THE SFC AND ALOFT...DRY WEATHER IS FIGURED FROM LATE MORNING
FRIDAY THROUGH THE DAY SATURDAY.
THE 00Z RUN OF THE ECMWF IS MORE ROBUST WITH THE PRECIP SUNDAY
MORNING. LOOKS LIKE ANOTHER POTENTIAL RAIN/SNOW SITUATION. WHILE THE
ECMWF WOULD INDICATE WARMER AIR AND A BETTER CHANCE OF RAIN...THE
GFS IS MUCH COOLER AND WOULD GIVE MAINLY RAIN. WILL CONTINUE WITH A
MODEL BLEND FOR THIS PERIOD...UNTIL A MORE SOLID CONSENSUS IS
DEVELOPED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 151 PM EDT TUE MAR 24 2015
VERY DRY AIR IN THE LOW TO MID LEVELS ASSOCIATED WITH HIGH PRES
MOVING E ACROSS THE LOWER GREAT LAKES TODAY WILL ENSURE VFR
CONDITIONS AT KIWD/KCMX/KSAW THROUGH THIS EVENING. LOW PRES LIFTING
NE TOWARD LAKE MICHIGAN TONIGHT WILL SPREAD SNOW INTO UPPER MI LATE
TONIGHT INTO WED MORNING. IFR CONDITIONS SHOULD REACH KIWD BY 10Z AND
KCMX BY 14Z AND THEN IMPROVE BACK UP TO MVFR BY LATE WED
MORNING/EARLY AFTERNOON. KSAW HAS BEST POTENTIAL FOR HEAVIER SNOW
CLOSER TO TRACK OF SFC LOW SO EXPECT CONDITIONS THERE TO LOWER TO
LIFR SHORTLY AFT 12Z AND THEN IMPROVE BACK TO MVFR BY 16Z AS SYSTEM
LIFTS QUICKLY E.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 557 AM EDT TUE MAR 24 2015
WITH HIGH PRES OVER THE GREAT LAKES REGION SHIFTING E WHILE LOW PRES
DEVELOPING OVER THE SRN PLAINS MOVES NE...WINDS WILL INCREASE TODAY
AND TONIGHT. SINCE PRES GRADIENT REMAINS RELATIVELY WEAK...WINDS
ACROSS LAKE SUPERIOR SHOULD REMAIN MOSTLY UNDER 20KT...THOUGH HIGH
OBS PLATFORMS WILL PROBABLY SEE SOME GUSTS TO AROUND 25KT. WINDS
WILL DIMINISH WED AS LOW PRES TROF SETS UP ACROSS THE LAKE BTWN ONE
LOW PRES CENTER MOVING E TOWARD LAKE SUPERIOR AND THE OTHER LIFTING
NE THRU LWR MI INTO ONTARIO. THE TROF WILL DROP S OF THE LAKE WED
NIGHT...AND WINDS WILL THEN INCREASE INTO THU AS HIGH PRES BUILDS S
TOWARD THE NRN PLAINS AND MUCH COLDER AIR SPREADS SE INTO THE UPPER
LAKES. NORTHERLY WINDS SHOULD INCREASE TO 20-30KT THU...AND IT`S NOT
OUT OF THE QUESTION THAT GALE FORCE GUSTS COULD OCCUR FOR A TIME
OVER CNTRL PORTIONS OF LAKE SUPERIOR. WINDS WILL THEN DIMINISH FRI
AS THE HIGH PRES ARRIVES OVER THE WRN GREAT LAKES. WIND WILL BEGIN
TO RAMP UP AGAIN SAT...ESPECIALLY LATE...AS THE HIGH SHIFTS TO THE
OHIO VALLEY AND LOW PRES DROPS SE INTO MANITOBA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1248 PM CDT TUE MAR 24 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT TUE MAR 24 2015
TOUGH FORECAST AHEAD FOR THIS AFTERNOON AND TONIGHT ON PTYPE AND
RESULTING PRECIPITATION AMOUNTS. THERE WAS QUITE THE DIFFERENCE
OUT THE GATE WITH THE 00Z RUNS BETWEEN THE NAM/GFS VERSUS THE
ECMWF/CANADIAN ON THE LAYOUT OF THE PRECIPITATION PATTERN
DEVELOPING LATER THIS AFTERNOON AND SPREADING ACROSS THE FA
TONIGHT. THE ECMWF AND CANADIAN ARE MUCH FARTHER SOUTH ON THE QPF
AXIS WITH A QUARTER INCH TONIGHT BARELY ACROSS THE SOUTHEAST PART
OF MN WHILE THE NAM/GFS HAVE THE QUARTER INCH INTO THE TWIN
CITIES. A CHECK ON RAP RUNS OVERNIGHT INDICATED A QPF PATTERN
DEVELOPING LIKE WHAT THE ECMWF AND CANADIAN ARE SHOWING. WE
BELIEVE PART OF REASON FOR THE DIFFERENCE IS THE CONVECTION
ONGOING TO OUR SOUTH THIS MORNING WITH STRONGER ACTIVITY PROGGED
FOR THIS AFTERNOON. THE NOSE OF THE 925-850MB MOISTURE TRANSPORT
WITH THE ECMWF JUST REACHES UP INTO NE IA THIS EVENING AND THEN
PASSES ACROSS SOUTHERN WI THIS EVENING. OUR INTERNAL MPX ARW-WRF
IS ALSO SHOWING THE QPF AXIS FURTHER SOUTH AS WELL. PTYPE THIS
AFTERNOON IS IN QUESTION WITH THE HRRR AND RAP SOUNDINGS
INDICATING SURFACE DEW POINTS RISING INTO THE LOWER AND MIDDLE 30S
ACROSS SOUTHERN MN WITH ALL RAIN INDICATED. THEY MAY BE TOO WARM
AS OUR MPX WRF SHOWS A CHANGE OVER TO SNOW ACROSS SOUTH CENTRAL MN
IN THE 21Z-24Z TIME FRAME ALONG WITH SOME FREEZING RAIN. HEADING
THROUGH THE EVENING...A DEEP MID LEVEL WAVE WILL PASS ACROSS IA/MO
WITH A DEFORMATION ZONE FROM NEAR KAEL TO KEAU. THIS IS THE ZONE
FOR 2 TO 4 INCHES OF SNOW ACCUMULATION TONIGHT WITH MUCH OF IT
OCCURRING BEFORE 06Z. SNOW AMOUNTS ARE LESS TO THE NORTHWEST WITH
AN INCH OR TWO IN THE TWIN CITIES WITH AROUND AN INCH AT ST.
CLOUD. BASED ON PTYPE ISSUES THIS AFTERNOON ALONG WITH THE SNOW
TONIGHT COUPLED WITH SOME MIXED SLEET AND FREEZING RAIN...WE
ISSUED A WINTER WEATHER ADVISORY FOR SOUTH CENTRAL MN BEGINNING
LATE THIS AFTERNOON WITH THE ADVISORY SPREADING NORTHEAST ACROSS
MUCH OF WEST CENTRAL WI FOR TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 410 AM CDT TUE MAR 24 2015
THE EXTENDED IS ACTUALLY LOOKING FAIRLY QUIET WITH THE MAIN
HAPPENINGS BEING THAT OF A PATTERN SHIFT...WITH A HIGHLY AMPLIFIED
PATTERN THIS WORK WEEK FLATTENING OUT AND BECOMING MORE ZONAL THIS
WEEKEND INTO NEXT WEEK. THE RESULT...TEMPS WILL REMAIN WELL BELOW
NORMAL THE REST OF THIS WORK WEEK...BUT BY THE WEEKEND...THEY WILL
REBOUND BACK TO NEAR OR EVEN A LITTLE ABOVE NORMAL.
THE LONG TERM WILL START WITH TONIGHTS TROUBLE MAKER PUSHING OUT OF
THE MPX AREA WEDNESDAY MORNING. GUIDANCE HAS CONTINUED TO PUSH WRAP
AROUND PRECIP WED/WED NIGHT FARTHER NORTH. IT IS LOOKING MORE AND
MORE LIKELY THAT THE MPX AREA WILL REMAIN DRY THIS PERIOD AS THE
WRAP AROUND MOISTURE STAYS CLOSER TO THE NRN SFC LOW THAT WILL BE
TRACKING ACROSS THE ARROWHEAD. HAVE CONTINUED THE TREND OF CUTTING
BACK POPS ON WEDNESDAY...WITH WED/WED NIGHT NOW BASICALLY DRY SOUTH
OF I-94. WHAT LOOKS MORE CERTAIN FOR WEDNESDAY ARE BREEZY
CONDITIONS. THE NAM SHOWS 3 HR PRESSURE RISES OF ABOUT 6 MB
FOLLOWING THE SFC LOW ACROSS THE ARROWHEAD...WITH 3 MB/3 HR RISES
ALL THE WAY DOWN INTO CENTRAL MN. IN ADDITION...BUFR SOUNDINGS UP AT
AXN SHOW MID CHANNEL MIX DOWN WINDS NEAR 35 KTS WITH TOP OF THE
CHANNEL WINDS AROUND 40 KTS. AS A RESULT...GAVE FORECAST WIND SPEEDS
A PRETTY GOOD BOOST FOR WEDNESDAY...WITH BORDERLINE WIND ADVY WINDS
NOW IN PLACE ACROSS WEST CENTRAL MN.
FOR THURSDAY AND FRIDAY...THE H5 FLOW BECOMES ALMOST NORTHERLY...
WHICH WILL ALLOW A 1035MB HIGH TO DROP DOWN OUT OF CANADA. WITH H85
TEMPS DOWN BETWEEN -6 TO -10C...WE WILL SEE HIGHS REMAIN IN THE 30S
BOTH DAYS...WITH SOME LOWS IN THE SINGLE DIGITS NOT OUT OF THE
QUESTION FRIDAY MORNING AS THE SFC HIGH SETTLES OVER MN AND OUR SNOW
COVER. THE ONE CHANGE SEEN WITH THE GUIDANCE THIS PERIOD IS THE
GEM/GFS/ECMWF ARE ALL SHOWING A QUICK HIT OF LIGHT PRECIP WORKING
ACROSS THE ERN DAKOTAS AND FAR WRN MN FRI/FRI NIGHT AS SHORT WAVE
ENERGY DROPPING DOWN IN THE NRLY FLOW WORKS WITH THE BAROCLINIC ZONE
ON THE BACKSIDE OF THE HIGH TO PRODUCE SOME LIGHT QPF. STILL HAVE A
DRY FORECAST OUT THAT DIRECTION...BUT IF THIS TREND CONTINUES...WE
MAY NEED TO START ADDING SOME SNOW CHANCES TO THE WEST FOR FRIDAY
EVENING.
THIS WEEKEND...AS THE UPPER FLOW BECOMES LESS AMPLIFIED...WE WILL
SEE A DEEP SFC LOW DROP OUT OF THE CANADIAN ARCTIC AND MOVE TOWARD
NW QUEBEC. WE WILL BE WELL WITHIN THE WARM SECTOR OF THIS SYSTEM...
THOUGH SAID WARM SECTOR IS STILL SCHEDULED TO COME THROUGH IN THE
DEAD OF NIGHT SATURDAY NIGHT. THE GEM/GFS BOTH HAVE A NICE SWATH OF
QPF WORKING DOWN WITH THE FRONT...BUT THE ECMWF CONTINUES TO BE DRY.
WITH THE GULF STILL CUT-OFF...THESE TYPES OF PATTERNS/FROPAS ARE
USUALLY DRY FOR US...SO DEFINITELY FAVOR THE DRIER ECMWF SOLUTION.
HOWEVER...WITH THE GEM/GFS IN THE BLENDING PROCEDURE USED...WE DO
HAVE POPS SPREAD ACROSS THE ENTIRE AREA SAT NIGHT...WITH THE HIGHEST
POPS OVER WI.
AFTER THIS WEEKEND...BOTH THE GFS/ECMWF SHOW THE REGION BEING DRY
UNTIL ANOTHER POWERFUL SPRING SYSTEM SHOWS UP TO WELCOME US TO APRIL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1240 PM CDT TUE MAR 24 2015
MAIN CHGS THIS AFTN WAS TO HOLD OFF ON SIGNIFICANT PRECIPITATION
UNTIL AFT 00Z. SLOWER MOVEMENT OF PRECIPITATION ACROSS NE/SD/IA
HAS LED TO A SLOWER SOLUTION ON THE ONSET OF -RA -SN AND OTHER
MIXED PRECIPITATION. IN ADDITION...HIGHER PRECIPITATION
RATES...ESPECIALLY IN TERMS OF SNOWFALL HAVE SHIFTED SLIGHTLY TO
THE SE OF OUR CWA. THEREFORE VSBYS MAY NOT BE AS LOW AS PREVIOUSLY
EXPECTED AT RNH/STC. OTHERWISE..KEPT -RASN DURING THE ONSET...WITH
A CHANGE OVER TO ALL SNOW DURING THE MID/LATE EVENING. CIGS WILL
LIKELY HOLD IN THE IFR/MVFR RANGE THRU THE PERIOD...WITH ONLY
RNH/EAU HAVING VFR INITIALLY THIS AFTN. WINDS WILL REMAIN FROM THE
SSE AND GUSTY THIS AFTN...BECOME MORE S/SW OVERNIGHT AND VEER TO
THE W/NW WEDNESDAY MORNING. HIGH CONFIDENCE IN MVFR/IFR CIGS
CONTINUING THRU 00Z...WITH LOWER CONFIDENCE ON VSBY RESTRICTION
THIS EVENING IN SNOW.
KMSP...
MAIN CHG FOR THIS TAF PERIOD IS TO HOLD OFF ON PRECIPITATION UNTIL
AFT 2Z...WITH THE BULK OF THE RAIN...CHG TO SNOW AFT 3Z. BEST CHC
OF IFR VSBY/CIGS IN SNOW WILL OCCUR IN THE 3-6Z TIME FRAME. WINDS
WILL BE GUSTY FROM THE SSE THIS AFTN...WITH WINDS DECREASING THIS
EVENING...VEERING TO THE SW BY 12Z...THEN MORE WNW/NW BY 18Z AND
BECOMING GUSTY AGAIN.
/OUTLOOK FOR KMSP/
WED NIGHT...VFR. WINDS NW 15G25 KTS EARLY.
THU...MVFR POSSIBLE EARLY. WINDS NNW 15G25 KTS.
FRI...VFR. WINDS NW 5-10 KTS BCMG SW IN THE AFTN.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 7 AM CDT
WEDNESDAY FOR MNZ077-078.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 4 AM CDT
WEDNESDAY FOR MNZ082>085-091>093.
WI...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 7 AM CDT
WEDNESDAY FOR WIZ024>028.
&&
$$
SHORT TERM...RAH
LONG TERM...MPG
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
223 PM CDT Tue Mar 24 2015
.SHORT TERM...(Tonight)
Issued at 141 PM CDT TUE MAR 24 2015
In the near term severe weather chances are the obvious concern.
Sfc low over just north of KEQA in se KS as of 18z will progress
east with a trailing dry line/sfc trough moving into the eastern
cwfa by 21z. Cap in place now, but a combo of daytime warming,
mid level cooling with increased lift and a narrow corridor of
low level moisture advection is expected to weaken the cap over
the next couple of hours allowing sfc convergence near the
boundary to initiate storms. Latest high res guidance (HRRR, among
others) have been consistent with developing convection by 21z-22z
close to the se KS/sw Mo state line. While model dew points may be
a bit bullish, still looks like a good bet with a corridor/broken
line of convection moving quickly w-e through the cwfa late this
afternoon and early this evening.
ML CAPE values of 1000-2000 j/kg indicated by the HRRR in a
narrow corridor along the sfc trough coupled with more than
adequate deep level 0-6 km bulk shear of around 40-50 kts and 0-3
km helicity of 200-300 m2/s2 will allow rotating updrafts to
develop with stronger convection. With somewhat limited low level
moisture/higher cloud bases, the main storm hazard will be hail
given steep mid level lapse rates. Localized severe winds also a
possibility. The tornado risk would appear low (but not zero),
again given the lack of deeper low level moisture and a veered low
level sfc wind profile along the sfc trough.
The severe window should be small time-wise. Storms should quickly
move east through the cwfa this evening, weakening late with more
limited instability.
.LONG TERM...(Wednesday through Tuesday)
Issued at 215 PM CDT TUE MAR 24 2015
A second shortwave, more positively tilted, will make it`s way
through the region Wed with a cold frontal passage expected.
Weather hazards may include some severe wx and a risk of excessive
rainfall over the southeast half of the cwfa.
Storms are expected to re-initiate in the afternoon gradually
coalescing into line segments, potentially training, over parts of
southern mo late in the afternoon and evening. Again the main
storm concerns will be during the initialization phase with hail
and winds with MLCAPE values of 1000-2000 j/kg over far southern
MO with abundant deep layer shear. With the potential for training
storms in the evening, some guidance is hitting rainfall amounts
hard (particularly the 12z ECMWF, NAM, GFS) in south central MO
where recent heavy rain and flooding occurred. Will be looking at
a possible flood watch for portions of the area, but still
ironing out the details.
Unseasonable cold is expected late in the week as a deep upper
level trough develops over much of the eastern CONUS. Nighttime
temperatures will drop below freezing late in the week. Small
scale shortwaves moving se through the region may kick off some
light/brief periods of rain/snow at times. A modest warming trend
develops late in the extended period.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 121 PM CDT TUE MAR 24 2015
Pilots flying in and out of
the southwest Missouri airports need to monitor radar closely late
this afternoon and this evening.
Severe thunderstorms are expected to develop near the Kansas and
the Missouri state line, and move east through much of southern
and central Missouri.
Large hail appears to be the main severe weather risk with these
storms.
By 8 or 9pm, this activity will shift east of the southwest
Missouri airports, allowing for VFR conditions the rest of the
night.
Look for surface winds to become light and variable by mid
evening.
Safe Travels.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...DSA
LONG TERM...DSA
AVIATION...Cramer
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
146 PM CDT Tue Mar 24 2015
.MESOSCALE DISCUSSION...
Issued at 141 PM CDT TUE MAR 24 2015
In the near term severe weather chances are the obvious concern.
Sfc low over just north of KEQA in se KS as of 18z will progress
east with a trailing dry line/sfc trough moving into the eastern
cwfa by 21z. Cap in place now, but a combo of daytime warming,
mid level cooling with increased lift and a narrow corridor of
low level moisture advection is expected to weaken the cap over
the next couple of hours allowing sfc convergence near the
boundary to initiate storms. Latest high res guidance (HRRR, among
others) have been consistent with developing convection by 21z-22z
close to the se KS/sw Mo state line. While model dew points may be
a bit bullish, still looks like a good bet with a corridor/broken
line of convection moving quickly w-e through the cwfa late this
afternoon and early this evening.
ML CAPE values of 1000-2000 j/kg indicated by the HRRR in a
narrow corridor along the sfc trough coupled with more than
adequate deep level 0-6 km bulk shear of around 40-50 kts and 0-3
km helicity of 200-300 m2/s2 will allow rotating updrafts to
develop with stronger convection. With somewhat limited low level
moisture/higher cloud bases, the main storm hazard will be hail
given steep mid level lapse rates. Localized severe winds also a
possibility. The tornado risk would appear low (but not zero),
again given the lack of deeper low level moisture and a veered low
level sfc wind profile along the sfc trough.
The severe window should be small time-wise. Storms should quickly
move east through the cwfa this evening, weakening late with more
limited instability.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
MESOSCALE...DSA
SHORT TERM...Gagan
LONG TERM...Gagan
AVIATION...Cramer
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
122 PM CDT TUE MAR 24 2015
.SYNOPSIS...
ISSUED AT 335 AM CDT TUE MAR 24 2015
AT 08Z...TWO MAIN AREAS OF SURFACE LOW PRESSURE EXIST. ONE
LOCATED IN FAR ERN WY WHILE THE OTHER IN THE OKLA PNHDL. VERY
LITTLE CURRENTLY ON THE KLBF RADAR EXCEPT FOR A NARROW BAND OF
SHOWERS AND SPRINKLES FROM SWRN CUSTER COUNTY INTO SERN LINCOLN
AND FRONTIER COUNTY. SCATTERED SHOWERS AND THUNDERSTORMS
CURRENTLY EXTEND FROM PARTS OF NCTRL KS INTO SCTRL AND SERN NEBR
AND NWRN MISSOURI WITH JUST OVER 200 LIGHTNING STRIKES THE PAST
HOUR.
&&
.UPDATE...
ISSUED AT 1016 AM CDT TUE MAR 24 2015
FORECAST WAS UPDATED DUE TO RADAR AND CLOUD TRENDS FOR THIS
MORNING AS RAIN SHOWERS OVER NORTH CENTRAL NEBRASKA ARE
PROGRESSING EAST AND SHOULD BE MOSTLY OUT OF THE FORECAST AREA
BY EARLY AFTERNOON. WITH LOW PRESSURE CENTERED OVER SOUTHWEST
NORTH DAKOTA AT MID MORNING...A SURFACE TROUGH WAS LOCATED THROUGH
WESTERN SOUTH DAKOTA AND DOWN THROUGH THE EASTERN NEBRASKA
PANHANDLE. THIS TROUGH WILL MAKE ITS WAY EAST TODAY AND AS CLOUDS
CLEAR BEHIND THE ONGOING PRECIPITATION...WARMING AHEAD OF THE
TROUGH WILL ALLOW SOME VERY WEAK INSTABILITY TO BUILD ROUGHLY FROM
NORTH CENTRAL INTO CENTRAL NEBRASKA THIS AFTERNOON. IT WILL BE
WEAK WITH THE RAP SHOWING 100-200J/KG OF MUCAPE. THIS MAY BE
ENOUGH FOR SOME LIGHT RAIN SHOWERS TO DEVELOP ALONG THE TROUGH
THIS AFTERNOON SO DID ADD IN A SLIGHT CHANCE FOR RAIN SHOWERS IN
THOSE AREAS. NO MENTION OF THUNDER AT THE TIME AS THE INSTABILITY
LOOKS TOO WEAK BUT WILL KEEP AN EYE ON THINGS INTO THE AFTERNOON.
RED FLAG WARNING FOR SOUTHWEST NEBRASKA REMAINS TO LOOK ON TRACK
AS DRY AIR IS EXPECTED TO PUSH INTO THE AREA WITH WINDS INCREASING
AS THE BOUNDARY LAYER BECOMES FULLY MIXED TO AROUND 700MB THIS
AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT TUE MAR 24 2015
TODAY...THE UPPER TROUGH CURRENTLY ACROSS WRN SD AND THE WRN
PNHDL WILL PROGRESS EASTWARD TODAY. SHOWERS WILL DEVELOP TO THE
EAT OF THIS TROUGH...MAINLY EAST OF A BASSETT THROUGH BROKEN BOW
LINE BY 15Z. LIKELY POPS ACROSS PORTIONS OF
BOYD...HOLT...GARFIELD AND WHEELER COUNTY. THIS IN GOOD AGREEMENT
BY LATEST RAP13...HRRR AND 06Z NAM MODELS. A FEW SHOWERS MAY ALSO
DEVELOP ACROSS FAR NRN NEBR THIS AFTERNOON WITHIN AREA OF A VORT
MAX MOVING THROUGH THAT AREA. HIGHS TODAY REMAIN NEAR PREVIOUS
FORECAST REACHING THE LOW TO MID 60S MOST AREAS. EXCEPTION WILL
BE IN FAR EASTERN AREAS WHERE CONSIDERABLE CLOUDINESS AND SHOWERS
TO HOLD DOWN HIGHS TO THE MID 50S. A FAIRLY STRONG PV ANOMALY
EMERGING FROM NERN CO INTO SWRN NEBR AND NWRN KS THIS MORNING
LOOKS FAVORABLE FOR MIXING DOWN STRONGER WINDS TO THE SURFACE
ACROSS THE SERN PNHDL AND SWRN NEBR INTO THIS AFTERNOON.
NORTHWEST WINDS IN THESE AREAS ARE FORECAST TO INCREASE TO 25 TO
35 MPH THIS AFTERNOON. EXPOSED WHEAT FIELDS AND OTHER TILLED
GROUND WILL BE SUSCEPTIBLE TO BLOWING DUST...AND ADDED AREAS OF
BLOWING DUST THIS AFTERNOON. IN ADDITION...CRITICAL FIRE WEATHER
CONDITIONS MET IN PORTIONS OF SWRN NEBR WITH DETAILS HIGHLIGHTED
IN THE FIRE WEATHER DISCUSSION.
TONIGHT...INCREASING CLOUDINESS ACROSS WRN NEBR AS A DISTURBANCE
IN NERN WY WILL DROP SOUTHEAST INTO NRN NEBR AND FAR SRN SD WITH
A SLIGHT CHANCE FOR SHOWERS...WHICH IS SIMILAR TO PREVIOUS
FORECAST. LOWS TO FALL MOSTLY INTO THE LOWER 30S. AN ASSOCIATED
COLD FRONT WILL ALSO MOVE INTO WRN NEBR TONIGHT AS A CLOSED UPPER
LOW SWINGS FROM NORTH DAKOTA INTO NRN MINNESOTA. THIS WILL DROP
H85 TEMPS TO BELOW 0C ACROSS NCTRL NEBR OVERNIGHT. ACROSS THE
WEST COAST...A STRONG UPPER RIDGE WILL MOVE IN.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 335 AM CDT TUE MAR 24 2015
COLD FRONT WILL BE PUSHING SOUTH ACROSS THE STATE WED MORNING.
MOSTLY CLOUDY SKIES EARLY WILL GIVE WAY TO DECREASING CLOUDS FOR
THE AFTERNOON. MARGINAL ELEVATED LIFT EARLY...HOWEVER DRY
LOWER/MID LEVELS AND FAST MOVING CLIPPER SHOULD KEEP PRECIP FROM
REACHING THE GROUND AND FORECAST CONTINUES TO BE DRY. COLD
ADVECTION FOR THE DAY WITH AND A SLOW START TO WARM UP DUE TO
MORNING CLOUDS SHOULD RESULT IN A COOL DAY...COMPARED TO RECENT.
HIGHS IN THE UPPER 40S TO MID 50S...WHICH IS FAIRLY CLOSE TO
NORMAL.
THURSDAY NORTHWEST FLOW WILL BRING A CLIPPER THROUGH THE AREA.
AGAIN CONCERNS WITH LOW/MID LEVEL MOISTURE...HOWEVER MODELS
BRINGING SOME PACIFIC MOISTURE ROUNDING THE WESTERN RIDGE WHICH
COULD SATURATE TOP DOWN. ANOTHER CONCERN WILL BE TEMPS. MORNING
TEMPS BELOW FREEZING WHICH COULD RESULT IN PRECIP STARTING OUT AS
SNOW OR A RAIN/SNOW MIX AS CLOUDS INCREASE TEMPS INTO THE 30S. BY
THE AFTERNOON...EVEN WITH THE CLOUDS...MODEL INCREASING TEMPS
INTO THE 40S AND LOWER 50S. MAYBE OPTIMIST WITH TEMPS...HOWEVER
00Z GUIDANCE HAS ACTUALLY CAME IN WARMER. WONDERING IF THE LACK
OF MOISTURE IS BECOMING MORE OF AN ISSUE RESULTING IN MORE PEAKS
OF SUN AND THE ABILITY TO WARM MORE.
ANY LINGERING PRECIP WILL BE CONFINED TO THE HIGHER TERRAIN INTO
THURSDAY NIGHT. CLOUDS HELP KEEP TEMPS WARMER IN THE WEST. HIGH
PRESSURE BUILDS ACROSS THE UPPER MISS RVR VALLEY...NOSES INTO NE
NEB WITH SOME CLEARING AND TEMPS COOL INTO THE LOWER 20S FOR N
CENTRAL.
WARM FRONT TO LIFT ACROSS THE AREA FRIDAY. MODELS IN AGREEMENT
WITH A FASTER TREND OF THE WARM FRONT. THE GFS PRODUCES SOME WARM
ADVECT SHOWERS IN THE MORNING ACROSS PORTIONS OF N CENTRAL...BUT
ONCE AGAIN MOISTURE DEPRIVED LOWER LEVELS AND HAVE GONE DRY.
MAYBE A FEW SPRINKLES BUT DO NOT THINK IT IS WORTH MENTIONED NOW.
RIDGE EXPANDS FOR THE WEEKEND. TEMPS CLIMB WELL ABOVE NORMAL WITH
MOST AREAS AT OR ABOVE 70 FOR SAT. FAST MOVING PACIFIC COLD FRONT
OVERNIGHT SAT. ALTHOUGH A COLD FRONT...CLOUDS WILL LIKELY KEEP
TEMPS UP OVERNIGHT...NEAR 40. WILL MONITOR FOR POSSIBLE LIGHT
PRECIP...HOWEVER BEST LIFT TO THE NORTH WITH THE LATEST RUN.
CLEARING BEHIND THE FRONT WITH BREEZY CONDITIONS IN THE WAKE OF
THE FRONT ON SUNDAY AND WINDS HELP MIX THE BL AND TEMPS REBOUND
NICELY. CONTINUED MILD TO START NEXT WEEK AND DRY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 121 PM CDT TUE MAR 24 2015
BREEZY NORTHWEST WINDS WILL SUBSIDE THIS EVENING THEN TURN TO THE
SOUTHWEST. A WEAK UPPER LEVEL SYSTEM WILL MOVE INTO THE CENTRAL
PLAINS THIS EVENING WHICH WILL BRING POTENTIAL FOR SOME RAIN AND
POSSIBLY A RAIN/SNOW MIX FOR A FEW HOURS ACROSS PORTIONS OF
NORTHERN NEBRASKA...GENERALLY NEAR AND WEST OF KVTN. THIS
PRECIPITATION SHOULD BE QUITE LIGHT...WITH MINIMAL IF ANY
VISIBILITY RESTRICTIONS ESPECIALLY OUTSIDE OF THE HIGHER TERRAIN
NEAR THE PINE RIDGE /KIEN AND KCDR/. SHOULD GET SOME LOWER
CEILINGS OVERNIGHT...BUT VERY DRY AIR IN THE LOW LEVELS WOULD
SUGGEST CEILINGS WILL STAY VFR. WINDS WILL SWITCH BACK TO THE
NORTH WEDNESDAY MORNING AND INCREASE WITH GUSTS UP AROUND 25KTS.
&&
.FIRE WEATHER...
ISSUED AT 335 AM CDT TUE MAR 24 2015
CRITICAL FIRE CONDITIONS ARE FORECAST ACROSS FIRE ZONES 210 AND
219 TODAY...WITH NEAR CRITICAL IN SOUTHERN PORTIONS OF 204 AND
206. STRONG NORTHWEST WINDS TO INCREASE TO 25 TO 35 MPH THIS
AFTERNOON ACROSS ZONES 210 AND 219 AS DEWPOINTS IN THESE AREAS
FALL TO 15 TO 20 AND HIGHS REACH THE MID 60S. THIS WILL BRING MIN
RH VALUES OF 12 TO 17 PERCENT. CONTINUATION OF RED FLAG WARNING
FOR ZONES 210 AND 219 IS WARRANTED WITH CLOSE MONITORING IN ZONES
204 AND 206.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR NEZ210-219.
&&
$$
UPDATE...BROOKS
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...BROOKS
FIRE WEATHER...ROBERG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
520 PM CDT TUE MAR 24 2015
.UPDATE...
ISSUED AT 520 PM CDT TUE MAR 24 2015
QUICK UPDATE TO REFLECT THE LATEST RADAR TRENDS THROUGH 22
UTC...BLENDED TO THE 18-21 UTC HRRR ITERATIONS THROUGH TONIGHT WHICH
HAVE A GOOD HANDLE ON THE WRAP AROUND PRECIPITATION BAND SO FAR
EARLY THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 342 PM CDT TUE MAR 24 2015
LOW PRESSURE NEAR BISMARCK AT 20 UTC WILL TRACK NORTHEAST NEAR
DEVILS LAKE BY MID EVENING AND TO FAR NORTHEAST NORTH DAKOTA AFTER
MIDNIGHT. THE RISK OF FREEZING RAIN HAS ENDED...WITH RAIN/SNOW
EXPECTED FOR THE REMAINDER OF THE AFTERNOON AND MAINLY SNOW
TONIGHT.
STRONG WINDS CONTINUE OVER SOUTHWEST NORTH DAKOTA ON THE BACK SIDE
OF THE SYSTEM...EXPECTED TO DIMINISH BY THIS EVENING AS THE
STRONGEST GRADIENT MOVES INTO CENTRAL NORTH DAKOTA. COULD BE A FEW
HOURS OF NEAR ADVISORY CRITERIA IN THE CENTRAL LATE AFTERNOON TO
EARLY EVENING...BUT AS MIXING LAYER SHRINKS THIS EVENING THINK
GUSTINESS WILL DIMINISH. IT WILL REMAIN BREEZY TO WINDY THROUGH
THE NIGHT...WITH THE STRONGEST WINDS MOVING INTO THE JAMES RIVER
VALLEY TO THE TURTLE MOUNTAINS LATE TONIGHT INTO WEDNESDAY
MORNING. WITH THE STRONGEST WINDS ALOFT AND FALL RISE COUPLET HERE
ARRIVING AT THE DIURNAL MINIMUM FOR WINDS...HAVE HELD OFF ON
ISSUING AN ADVISORY. WILL BE MARGINAL THOUGH AND EVENING AND
OVERNIGHT SHIFT CAN CONTINUE TO MONITOR.
SNOW IS TAPERING OFF OVER FAR WESTERN NORTH DAKOTA AND WE HAVE
CANCELLED THE WINTER WEATHER ADVISORY FOR DIVIDE AND WILLIAMS
COUNTIES. SNOW CONTINUES ACROSS MUCH OF CENTRAL NORTH DAKOTA. THE
SNOW IS EXPECTED TO LIFT NORTH AND EAST TONIGHT. REPORTS SO FAR OF
1 TO 2 INCHES FROM AROUND WILLISTON TO STANLEY THIS AFTERNOON.
ANOTHER INCH OR TWO IS POSSIBLE FROM AROUND STANLEY TO KENMARE AND
SHERWOOD EAST THROUGH MINOT AND BOTTINEAU...RUGBY AND BELCOURT.
TOTAL SNOW AMOUNTS OF 3 TO 5 INCHES MAY BE REALIZED IN A FEW
LOCAL AREAS OF THE FAR NORTH CENTRAL...BUT EXPECT MOST AREAS TO BE
IN THE 1 TO 3 INCH RANGE. EXCEPT FOR THE NORTHWEST COUNTIES
MENTIONED ABOVE...WILL CONTINUE THE CURRENT ADVISORY OVER THE FAR
NORTH CENTRAL. MAIN THREATS WILL BE SLIPPERY ROADS AND REDUCED
VISIBILITIES IN SNOW AND BLOWING SNOW.
SNOW WILL TAPER OFF ACROSS THE FAR NORTH CENTRAL AND EAST CENTRAL
EARLY WEDNESDAY MORNING. OTHERWISE EXPECT A DRY BUT BREEZY TO
WINDY AND SEASONABLY COLD DAY WITH HIGHS MAINLY IN THE 30S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 342 PM CDT TUE MAR 24 2015
THE EARLY PORTION OF THE LONG TERM PERIOD...WEDNESDAY NIGHT THROUGH
SATURDAY...WILL FEATURE A 500MB RIDGE OVER THE WEST COAST THAT WILL
STRENGTHEN AND EXPAND EAST INTO THE ROCKIES.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT:
THIS WEST COAST RIDGE WILL KEEP A NORTHWEST FLOW OVER NORTH DAKOTA
AND ALLOW SOME UPPER LEVEL SHORTWAVE ENERGY IMPULSES TO MOVE
SOUTHEAST THROUGH THE FLOW. THIS UPPER LEVEL INSTABILITY WILL
ENHANCE SOME LOW LEVEL LIFTING OVER FAR WESTERN NORTH DAKOTA
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT - ON THE WESTERN EDGE OF
CANADIAN HIGH PRESSURE OVER THE EASTERN DAKOTAS. COOL WITH HIGHS IN
THE 30S AND 40S ACROSS THE REGION.
FRIDAY:
AS THE LARGE-SCALE RIDGE BUILDS AND EXPANDS...IT WILL PUSH A
STRONGER UPPER LEVEL SHORTWAVE EASTWARD ACROSS NORTH DAKOTA
ACCOMPANIED BY A WARM FRONT. CHANCES OF MAINLY LIGHT SNOW ALONG AND
AHEAD OF THE WARM FRONT...CHANGING TO RAIN BEHIND IT. LOOK FOR HIGHS
FROM THE 30S IN THE TURTLE MOUNTAINS AND JAMES VALLEY TO THE 50S IN
THE WEST.
SATURDAY THROUGH TUESDAY:
THE UPPER LEVEL RIDGE BREAKS DOWN SATURDAY...BUT A WARM DAY AHEAD OF
A SURFACE FRONTAL BOUNDARY THAT SHOULD MOVE ACROSS THE STATE
SATURDAY NIGHT. HIGHS SATURDAY IN THE 50S AND 60S.
PACIFIC HIGH PRESSURE FOLLOWS THE FRONTAL BOUNDARY WITH MILD
CONDITIONS - HIGHS IN THE 50S TO MID 60S SUNDAY THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY)
ISSUED AT 519 PM CDT TUE MAR 24 2015
WIDESPREAD MVFR STRATUS WILL IMPACT ALL OF WESTERN AND CENTRAL
NORTH DAKOTA THROUGH WEDNESDAY MORNING. IFR CONDITIONS ARE FAVORED
IN SNOW AT KMOT THROUGH 07-08 UTC...POSSIBLY IMPACTING KBIS
THROUGH 01-03 UTC AND KJMS LATER TONIGHT. STRONG NORTHWEST WINDS
WITH GUSTS OF 25 TO 35 KTS WILL CONTINUE THIS EVENING AND TONIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM CDT WEDNESDAY FOR NDZ002>005-
010-011.
WIND ADVISORY UNTIL 6 PM MDT THIS EVENING FOR NDZ040-041-043-044.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...JV
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
248 PM EDT TUE MAR 24 2015
.SYNOPSIS...
WARM FRONT LIFTS NORTH TONIGHT. COLD FRONT CROSSES THURSDAY. HIGH
PRESSURE SLOW TO TAKE CONTROL. MUCH COLDER AIR FOR FRIDAY AND
SATURDAY. NEXT COLD FRONT SUNDAY NIGHT/MONDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
FLOW AMPLIFIES THIS PERIOD...WITH WARM AIR PUSHING NWD W OF THE
MOUNTAINS...AND THE ASSOCIATED TIGHTENING PRESSURE GRADIENT
ENCOURAGING CAD WEDGE ON INCREASING SE FLOW E OF THE MOUNTAINS.
SPOTTY LIGHT RAIN WAS WORKING EWD INTO THE AREA FROM THE LOWER OH
VALLEY...N OF A WARM FRONT EDGING INTO SRN KENTUCKY. THIS SPOTTY
LIGHT RAIN WILL INCREASE IN COVERAGE SOMEWHAT AS IT PUSHES NWD
TONIGHT AHEAD OF THE ADVANCING WARM FRONT...WITH THE HELP OF AN
INITIAL UPPER LEVEL S/W TROUGH LIFTING THROUGH THE OHIO VALLEY.
AS THE S/W LIFTS THROUGH THE GREAT LAKES ON WED....THE COLD FRONT
ASSOCIATED WITH THE CORRESPONDING SFC LOW LOSES ITS PUSH...SO HAVE
JUST A MINIMAL CHANCE FOR SHOWERS TRAVERSING THE FCST AREA BENEATH
WEAK UPPER LEVEL RIDGING AHEAD OF THE NEXT S/W TROUGH...WELL
UPSTREAM WED AFTERNOON.
USED THE HRRR AND MET FOR TEMPERATURES TONIGHT WHICH WILL BECOME
NEARLY STEADY OVERNIGHT...PERHAPS A SLIGHT RISE W OF AND A SLIGHT
FALL E OF THE MOUNTAINS IN THE AMPLIFYING FLOW. BLENDED IN THE MET
AND BIAS CORRECTED MAV FOR A WARM WED AFTERNOON IN THE WARM SECTOR.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AN AREA OF LOW PRESSURE...WHICH SHOULD BE LOCATED NEAR ARKANSAS AT
THE BEGINNING OF THE PERIOD...WILL MOVE TO OHIO BY 12Z THURSDAY AND
THEN CONTINUE NORTHEASTWARD ACROSS NEW ENGLAND INTO THE ATLANTIC
OCEAN BY THURSDAY NIGHT. AS THIS FEATURE MOVES ACROSS PA...A COLD
FRONT WILL BE DRAGGED EASTWARD. CURRENT THINKING IS THE FRONT WILL
BE WEST OF OUR AREA AT 12Z...ALONG A CKB TO CRW TO JKL LINE AT
18Z...AND THEN BE EAST OF THE AREA AFTER 21Z.
HAVE THUNDER IN THE FORECAST FOR EARLY WEDNESDAY NIGHT...ACROSS OUR
SOUTHWESTERN COUNTIES. THE INSTABILITY SHOULD WANE AFTER SUNSET AND
EXPECT ANY STORMS WILL DISSIPATE BY 03Z. HOWEVER...THE THREAT OF
THUNDERSTORMS WILL REDEVELOP ACROSS THE AREA...ALONG AND EAST OF THE
COLD FRONT ON THURSDAY.
EVEN AS FRONT PUSHES EAST...AN UPPER LEVEL TROF WILL KEEP PRECIP
CHANCES IN THE FORECAST. THE TROF SHOULD PUSH EAST LATER FRIDAY/
FRIDAY NIGHT BRINGING PRECIPITATION CHANCES TO AN END IN MOST
LOCATIONS.
COLDER AIR WILL FILTER INTO THE AREA THURSDAY NIGHT...WITH LOWS
THURSDAY NIGHT ABOUT 15-20 DEGREES COLDER THAN THOSE EXPECTED
WEDNESDAY NIGHT. THE PRECIPITATION SHOULD MIX WITH...OR CHANGE TO
SNOW...ACROSS MUCH OF THE AREA...WITH SOME POSSIBLE LIGHT SNOW
ACCUMULATIONS ACROSS THE HIGHEST ELEVATIONS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LONG RANGE MODELS CONTINUE TO BRING MID MINUS TEENS INTO THE CENTRAL
APPALACHIANS FOR THE WEEKEND AS A DEEP TROUGH TROUGH ALOFT CUTS IN.
WILL CONTINUE TO SIT ON THE LOW SIDE OF GUIDANCE NUMBERS AND
BELOW...ESPECIALLY INTO SATURDAY NIGHT WITH THE CLEARER SKIES AND
POTENTIAL FOR EFFICIENT RADIATIONAL COOLING. SATURDAY TEMPERATURES
WILL BE ON THE ORDER OF 20 DEGREES BELOW NORMAL. COLD FRONT COMES
THROUGH SUNDAY NIGHT/MONDAY WITH THE NEXT BATCH OF PRECIPITATION.
TEMPERATURES MODIFY OUT OF THE COLDER PATTERN FOR THE BEGINNING OF
NEXT WEEK AND APPROACH NORMAL LEVELS ONCE AGAIN.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
LIGHT RAIN AHEAD OF A WARM FRONT PUSHING NWD THROUGH THE AREA
TONIGHT WILL CAUSE LITTLE FLIGHT CAT RESTRICTIONS.
HOWEVER...MOISTENING AND STRENGTHENING SE FLOW ON THE E SLOPES OF
THE MOUNTAINS IS LIKELY TO BRING MVFR STRATOCU THERE OVERNIGHT
TONIGHT AND WED. A STRATOCU DECK MAY REACH THE OHIO RIVER FROM THE
W TOWARD THE END OF THE TAF PERIOD...BEFORE MIXING OUT WED AFTERNOON.
LIGHT NE SFC FLOW WILL VEER TO SE TONIGHT...AND THEN STRENGTHEN FROM
THE S WED...POSSIBLY BECOMING A BIT GUSTY...ESPECIALLY ON THE
RIDGES. LIGHT W FLOW ALOFT WILL BECOME SW OVERNIGHT AND INCREASE TO
MODERATE BY WED MORNING...AND BE MODERATE TO STRONG SW THROUGH
MIDDAY WED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING THE LOWER CEILINGS DEVELOPING TONIGHT
ALONG THE EASTERN SLOPES COULD BE SLOWER DEVELOPING AROUND BKW THAN
FORECAST. THESE CIGS MAY GET CLOSE TO IFR OVERNIGHT INTO EARLY WED
MORNING. THERE IS UNCERTAINTY AS TO MVFR CEILINGS REACHING THE OHIO
RIVER MIDDAY WED. THE SPOTTY LIGHT RAIN COULD LEAD TO MVFR VSBYS
HERE AND THERE OVERNIGHT TONIGHT...BUT INCREASING FLOW SHOULD
PREVENT THIS FROM BECOMING TOO MUCH OF A FACTOR.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H M H H H H H H H H
PKB CONSISTENCY M H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z WEDNESDAY...
IFR CONDITIONS POSSIBLE IN SHOWERS AND POSSIBLE THUNDERSTORMS THU.
IFR POSSIBLE ACROSS NRN WV AND DOWN THROUGH THE MOUNTAINS THU NT IN
MIXED RAIN AND SNOW SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JSH/TRM/26
NEAR TERM...TRM
SHORT TERM...JSH
LONG TERM...26
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
206 PM EDT TUE MAR 24 2015
.SYNOPSIS...
WARM FRONT LIFTS NORTH TONIGHT. COLD FRONT CROSSES THURSDAY. HIGH
PRESSURE SLOW TO TAKE CONTROL IN MUCH COLDER AIR FOR FRIDAY INTO THE
WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
FLOW AMPLIFIES THIS PERIOD...WITH WARM AIR PUSHING NWD W OF THE
MOUNTAINS...AND THE ASSOCIATED TIGHTENING PRESSURE GRADIENT
ENCOURAGING CAD WEDGE ON INCREASING SE FLOW E OF THE MOUNTAINS.
SPOTTY LIGHT RAIN WAS WORKING EWD INTO THE AREA FROM THE LOWER OH
VALLEY...N OF A WARM FRONT EDGING INTO SRN KENTUCKY. THIS SPOTTY
LIGHT RAIN WILL INCREASE IN COVERAGE SOMEWHAT AS IT PUSHES NWD
TONIGHT AHEAD OF THE ADVANCING WARM FRONT...WITH THE HELP OF AN
INITIAL UPPER LEVEL S/W TROUGH LIFTING THROUGH THE OHIO VALLEY.
AS THE S/W LIFTS THROUGH THE GREAT LAKES ON WED....THE COLD FRONT
ASSOCIATED WITH THE CORRESPONDING SFC LOW LOSES ITS PUSH...SO HAVE
JUST A MINIMAL CHANCE FOR SHOWERS TRAVERSING THE FCST AREA BENEATH
WEAK UPPER LEVEL RIDGING AHEAD OF THE NEXT S/W TROUGH...WELL
UPSTREAM WED AFTERNOON.
USED THE HRRR AND MET FOR TEMPERATURES TONIGHT WHICH WILL BECOME
NEARLY STEADY OVERNIGHT...PERHAPS A SLIGHT RISE W OF AND A SLIGHT
FALL E OF THE MOUNTAINS IN THE AMPLIFYING FLOW. BLENDED IN THE MET
AND BIAS CORRECTED MAV FOR A WARM WED AFTERNOON IN THE WARM SECTOR.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
FRONTAL ZONE HUNG UP IN OUR VICINITY WEDNESDAY AND WEDNESDAY NIGHT
AS ONE SURFACE LOW DEPARTS TO THE NE WHILE ANOTHER APPROACHES FROM
THE SW. HAVE GENERALLY CHANCE POPS ACROSS THE NORTH AND WEST...WITH
SLIGHT CHANCE ACROSS THE FAR SOUTH. ALSO HAVE SOME THUNDER MENTIONED
WEDNESDAY AFTERNOON...MAINLY IN THE OHIO RIVER VALLEY. STRONG COLD
FRONT SURGES THROUGH ON THURSDAY...WITH SHOWERS AND THUNDERSTORMS.
MODELS BEGINNING TO HINT AT A SECONDARY WAVE RIDING UP THE FRONT
DURING THE AFTERNOON AND EVENING WHICH MAY CAUSE IT TO HANG UP
ACROSS THE MOUNTAINS FOR A TIME. WEDNESDAY LOOKS WARM...WELL ABOVE
AVERAGE. ALTHOUGH NOT REAL DRASTIC...DO HAVE A NON-DIURNAL ON
THURSDAY...MAINLY IN SE OHIO.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
COLDER TREND SHAPING UP FOR THE EXTENDED BEHIND A COLD FRONT EXITING
THURSDAY NIGHT. DUE TO THE LINGERING NORTHWEST FLOW AND TEMPERATURES
DROPPING...SOME SCATTERED LIGHT SNOW IS POSSIBLE HEADING INTO FRIDAY
NIGHT IN THE LINGERING LOW LEVEL MOISTURE. A BRIEF HIGH PRESSURE
SYSTEM MODIFIES THE TEMPERATURES SUNDAY BACK TOWARDS NORMAL VALUES
FOR LATE MARCH. HOWEVER...ANOTHER LOW PRESSURE SYSTEM ROTATING
THROUGH BROAD UPPER LEVEL TROUGH PARKED OVER THE EASTERN THIRD OF
THE CONUS WILL KNOCK THEM BACK DOWN ONCE AGAIN. THE NEXT CHANCES
FOR PRECIPITATION ARRIVE WITH THIS SYSTEM IN THE SUNDAY
NIGHT/MONDAY TIME FRAME.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
LIGHT RAIN AHEAD OF A WARM FRONT PUSHING NWD THROUGH THE AREA
TONIGHT WILL CAUSE LITTLE FLIGHT CAT RESTRICTIONS.
HOWEVER...MOISTENING AND STRENGTHENING SE FLOW ON THE E SLOPES OF
THE MOUNTAINS IS LIKELY TO BRING MVFR STRATOCU THERE OVERNIGHT
TONIGHT AND WED. A STRATOCU DECK MAY REACH THE OHIO RIVER FROM THE
W TOWARD THE END OF THE TAF PERIOD...BEFORE MIXING OUT WED AFTERNOON.
LIGHT NE SFC FLOW WILL VEER TO SE TONIGHT...AND THEN STRENGTHEN FROM
THE S WED...POSSIBLY BECOMING A BIT GUSTY...ESPECIALLY ON THE
RIDGES. LIGHT W FLOW ALOFT WILL BECOME SW OVERNIGHT AND INCREASE TO
MODERATE BY WED MORNING...AND BE MODERATE TO STRONG SW THROUGH
MIDDAY WED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING THE LOWER CEILINGS DEVELOPING TONIGHT
ALONG THE EASTERN SLOPES COULD BE SLOWER DEVELOPING AROUND BKW THAN
FORECAST. THESE CIGS MAY GET CLOSE TO IFR OVERNIGHT INTO EARLY WED
MORNING. THERE IS UNCERTAINTY AS TO MVFR CEILINGS REACHING THE OHIO
RIVER MIDDAY WED. THE SPOTTY LIGHT RAIN COULD LEAD TO MVFR VSBYS
HERE AND THERE OVERNIGHT TONIGHT...BUT INCREASING FLOW SHOULD
PREVENT THIS FROM BECOMING TOO MUCH OF A FACTOR.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H M H H H H H H H H
PKB CONSISTENCY M H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z WEDNESDAY...
IFR CONDITIONS POSSIBLE IN SHOWERS AND POSSIBLE THUNDERSTORMS THU.
IFR POSSIBLE ACROSS NRN WV AND DOWN THROUGH THE MOUNTAINS THU NT IN
MIXED RAIN AND SNOW SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/TRM/MZ
NEAR TERM...TRM
SHORT TERM...MZ
LONG TERM...26
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
311 PM CDT TUE MAR 24 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 307 PM CDT TUE MAR 24 2015
SYSTEM MOVING EAST ACROSS THE EASTERN PART OF THE AREA WILL
CONTINUE TO BRING THE GREATEST PRECIPITATION TO NORTHWEST IA
LATE THIS AFTERNOON INTO THE EVENING. THOUGH THERE HAS NOT BEEN MUCH
IN THE WAY OF SNOW SO FAR...WE HAVE BEEN GOING TO A LATE AFTERNOON
PEAK IN THE ACCUMULATION THREAT AND THE RAP SOUNDINGS ON BUFKIT HAVE
BEEN SHOWING A CONTINUED FIT WITH THAT IDEA. WITH SOME SPOTTY ICING
TO BOOT...WILL CONTINUE THE WINTER WEATHER ADVISORY FOR THE EASTERN
COUNTIES OF NORTHWEST IOWA. THE SPOTTY ICING IS LIKELY TO ABATE BUT
MAY SHOW UP AGAIN THIS EVENING WITH A VERY SLIGHT DROP IN
TEMPERATURES AND THE LOSS OF THE SOLAR RADIATION EFFECT THROUGH THE
CLOUDS. AS FOR THE SNOW...A COUPLE INCHES OF SLUSH WOULD COME
QUICKLY AND AT THE TIME PEOPLE ARE LIKELY TO BE OUT DRIVING...WHAT I
CALL THE PRAIRIE EARLY EVENING RUSH HOUR.
PRECIPITATION SHOULD END STEADILY FROM THE WEST LATE THIS AFTERNOON
AND THIS EVENING WHILE LOW CLOUDS WILL BE MORE STUBBORN...LASTING
THROUGH THE NIGHT FAR EAST/NORTHEAST. MEANWHILE...WEAK UPPER WAVE
SLIDING EAST SOUTHEAST TOWARD THE SOUTHERN EDGE OF THE AREA COULD
BRING SOME VERY SPOTTY LIGHT PRECIPITATION LATE TONIGHT INTO THE
START OF THE MORNING TO THE MISSOURI RIVER AREA...BUT POPS WILL BE
LOW AND THE DURATION OF ANY PRECIPITATION SHORT.
THE COLD FRONT ARRIVES LATE TONIGHT AND NORTHWEST WINDS QUICKLY
BECOME ESTABLISHED AT THE SURFACE. CONDITIONS SHOULD BECOME
WINDY BUT LOOKS LIKE WINDS WILL HOLD SHORT OF WIN ADVISORY LEVELS
EVEN THOUGH I AM GOING A LITTLE STRONGER THAN GUIDANCE IN THE MIXED
AIR.
SOME CLOUDS LIKELY IN THE COOL BUT MIXED AIR...BUT DO NOT EXPECT
THEM TO BE SOLID...AND CLOUDS SHOULD BE DECREASING IN THE
AFTERNOON.
AFTER LOWS NEAR OR JUST ABOVE 30 TONIGHT...MEANING LITTLE DROP INT
HE EAST...WEDNESDAY SHOULD BRING HIGHS MOSTLY IN THE 40S WITH A FEW
50 DEGREE READINGS SOUTH. THAT WILL OF COURSE BE WARMER FOR MOST OF
THE AREA BUT COOLER SOUTHWEST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 307 PM CDT TUE MAR 24 2015
GENERALLY A RATHER TRANQUIL MEDIUM AND EXTENDED FORECAST WITH ONLY A
FEW TROUBLE SPOTS. SHARP NWLY WILL DEVELOP BY THURSDAY AND FRIDAY IN
THE WAKE OF TODAYS SYSTEM. THIS WILL SPELL A RETURN TO NEAR OR
SLIGHTLY BELOW NORMAL TEMPERATURES INTO THE END OF THE WEEK. WITH
MID-LVL RIDGING AMPLIFYING OVER THE WEST COAST...AND A PAIR OF
SHORTWAVES DROPPING DOWN THE WESTERN FLANK OF THE BROAD UPPER
TROUGH...A TIGHTENING LOW-LVL BAROCLINIC ZONE WILL DEVELOP ACROSS
THE DAKOTAS. THE FIRST SYSTEM WILL ZIP THROUGH THURSDAY...AND A
SECOND LATE FRIDAY. QPF WITH THESE SYSTEMS WILL BE LIGHT...BUT
COULD NOT RULE OUT THE OCCASIONAL RAIN/SNOW MIXTURE BOTH DAYS WITH
HIGHEST CHANCES FOR THE LOCAL AREA ON FRIDAY.
WE WILL SEE A GRADUAL WARMING TREND BEGIN THIS WEEKEND AND CONTINUE
INTO NEXT WEEK AS HEIGHTS BEGIN TO RISE OVER THE CENTRAL US. THE
WARMEST TEMPERATURES WILL BE FOCUSED EARLY NEXT WEEK WHERE WE COULD
MAKE A RUN INTO THE 70S ONCE AGAIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1239 PM CDT TUE MAR 24 2015
MVFR TO IFR IN LOW CEILINGS...RAIN OR MIXED PRECIPITATION...AND
LIGHT FOG WILL ABATE TO VFR WEST OF THE JAMES RIVER THROUGH
25/00Z. EAST OF THE JAMES RIVER...PRECIPITATION AND LOWERED
VISIBILITIES SHOULD IMPROVE TO VFR VISIBILITIES FROM THE WEST
21Z-25/03Z...BUT CEILINGS 1-3K FEET ARE EXPECTED TO REMAIN. COLD
FRONT WILL BRING CEILINGS 2-4K FEET AFTER 25/12Z. SURFACE GUSTS TO
25 KNOTS MAY DEVELOP NORTHWEST OF BKX TO YKN AREA AFTER 25/15Z.&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...WINTER WEATHER ADVISORY UNTIL 1 AM CDT WEDNESDAY FOR IAZ002-003-
013-014-021-022-032.
&&
.FIRE WEATHER...
ISSUED AT 307 PM CDT TUE MAR 24 2015
A COLD FRONT WILL PASS THROUGH THE AREA WEDNESDAY
MORNING...BRINGING RATHER GUSTY WINDS ALONG WITH IT. TODAYS
WETTING RAINS HAVE MAINLY IMPACTED AREAS EAST OF THE JAMES
RIVER...LEAVING FUELS IN THE AREAS WEST OF THE RIVER DRY.
RELATIVE HUMIDITY VALUES WILL VALL INTO THE 25 TO 35 PERCENT RANGE
TOMORROW AFTERNOON...AND WILL LEAD TO HIGH TO VERY HIGH FIRE
DANGER RISKS IN THE AFTERNOON.
COOLER TEMPERATURES MOVE IN FOR THURSDAY AND FRIDAY...MINIMIZING
THE WILDFIRE RISK.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...WINTER WEATHER ADVISORY UNTIL 1 AM CDT WEDNESDAY FOR IAZ002-003-
013-014-021-022-032.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...DUX
AVIATION...
FIRE WEATHER...DUX
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 212 PM CDT TUE MAR 24 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW CANADIAN
HIGH PRESSURE SHIFTING EAST OVER THE EASTERN GREAT LAKES EARLY THIS
AFTERNOON WHILE LOW PRESSURE IS MOVING ALONG THE KANSAS/OKLAHOMA
BORDER. AHEAD OF THE LOW...AN AREA OF MIXED PRECIPITATION WITH SOME
EMBEDDED THUNDERSTORMS IS OCCURRING OVER IOWA ON THE NOSE OF THE LLJ
AND REGION OF MOISTURE ADVECTION. THE SHORTWAVE AS THE PRIMARY
UPPER SUPPORT RESIDES OVER WESTERN KANSAS AND LOOKS RATHER
IMPRESSIVE EARLY THIS AFTERNOON. AS THE LOW HEADS NORTHEAST TOWARDS
SOUTHERN LAKE MICHIGAN TONIGHT...TIMING THE WINTRY PRECIP AND
POTENTIAL AMOUNTS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...LEANED AWAY FROM THE NAM FOR THIS FORECAST...AS IT APPEARS
TO BE TOO FAR NORTH FROM THE CONSENSUS OF THE GFS/CANADIAN/AND
SREF. TAKING THE BLEND OF THE CONSENSUS...LOW PRESSURE WILL TRACK
FROM WESTERN MISSOURI TO SOUTHERN LAKE MICHIGAN TONIGHT. A BEEFY
LLJ UPWARDS OF 50KTS WILL SURGE NORTHEAST AHEAD OF THE LOW AND WILL
BE POINTED AT SOUTHERN WISCONSIN BY MIDNIGHT. THIS LLJ WILL
TRANSPORT PWATS BETWEEN 0.5 AND 0.75 INCHES ACROSS THE FORECAST AREA
(AS OPPOSED TO 0.15 PWAT CURRENTLY). WITH THE APPROACH OF THE LOW
AND SHORTWAVE...QG FORCING AND MID-LEVEL FGEN WILL STRENGTHEN TO SUPPORT
AN AREA OF PRECIP SPREADING NORTHEAST INTO CENTRAL WISCONSIN AND THE
SOUTHERN FOX VALLEY BETWEEN 03-06Z...AND THEN ACROSS THE REST OF THE
FORECAST AREA BY 10Z. THE STRONG LIFT AND AMPLE MOISTURE WILL LEAD
TO A RATHER INTENSE PERIOD OF PRECIP ONCE IT ARRIVES. TEMPERATURES
ALOFT REMAIN RATHER UNCERTAIN...BUT AM COUNTING ON THE INTENSE
PRECIP RATES AND LIFT TO COOL THE SLIGHTLY ABOVE FREEZING TEMPS
BETWEEN 850-800MB BACK TO OR BELOW FREEZING. AS A RESULT...AM
THINKING PRECIPITATION TYPES WILL BE MAINLY SNOW WITH SOME SLEET MIX
IN FROM WAUTOMA TO THE DOOR. AREAS AROUND
MANITOWOC/CALUMET/KEWAUNEE HAVE POTENTIAL TO SEE MIXED PRECIP THE
LONGEST...AND THIS WILL CUT INTO SNOW ACCUMULATIONS THERE SOME.
THOUGH SNOWFALL RATES COULD APPROACH AN INCH PER HOUR IN THE MORE
INTENSE SNOW BANDS...THE QUICK FORWARD MOTION OF THE SYSTEM WILL
ALSO LIMIT ACCUMS. WILL SHOW A WIDESPREAD 2 TO 4 INCHES...LOCALLY
HIGHER OVER THE FOX VALLEY WHERE WILL HAVE THE HIGHEST AMOUNTS.
THIS LOOKS LIKE A SOLID ADVISORY...PERHAPS TOWARDS A HIGHER END
ADVISORY OVER EASTERN WISCONSIN IF THERE IS LESS OF A MIX...AND
SNOWFALL RATES BECOME AN INCH PER HOUR. NORTH-CENTRAL WISCONSIN MAY
ONLY SEE 1-3 INCHES...BUT IT WILL BE SNOWING FOR THE MORNING
COMMUTE...THUS AN ADVISORY STILL LOOKS REASONABLE.
WEDNESDAY...SNOW WILL BE ONGOING ACROSS NORTH-CENTRAL AND FAR
NORTHEAST WISCONSIN WHERE AN ADDITIONAL INCH COULD FALL BY
MID-MORNING. ELSEWHERE...SNOW WILL BE DIMINISHING AS THE LOW TRACKS
TOWARDS NORTHERN LOWER MICHIGAN. REGARDLESS...THE MORNING COMMUTE
WILL LIKELY BE MESSY FOR MOST LOCATIONS. BEHIND THE SYSTEM...THE
REGION WILL BE UNDER THE INFLUENCE OF BROAD CYCLONIC FLOW. DRY
SLOTTING WILL MOVE OVER CENTRAL AND NORTHEAST WISCONSIN DURING THE
AFTERNOON...BUT THE SOUTHERN EXTENT OF THE COMMA HEAD WILL LINGER
OVER N-C WISCONSIN WHERE WILL LEAVE A CHANCE OF RAIN AND SNOW
THROUGH THE DAY. WEST WINDS WILL BECOME GUSTY DURING THE AFTERNOON
AS LOW LEVEL LAPSE RATES STEEPEN. GENERALLY REMAINING MOSTLY CLOUDY
WITH HIGHS RANGING FROM THE UPPER 30S TO MIDDLE 40S.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 212 PM CDT TUE MAR 24 2015
COLD CYCLONIC FLOW ALOFT WILL DOMINATE THE WEATHER PATTERN INTO
THE WEEKEND...BRINGING BELOW NORMAL TEMPERATURES ALONG WITH CHANCES
OF RAIN AND SNOW AT SOME POINT WEDNESDAY NIGHT AND THURSDAY. PERSISTENT
NORTHERLY FLOW OFF LAKE SUPERIOR WILL BRING OCCASIONAL SNOW SHOWERS
TO FAR NORTHERN WISCONSIN WHERE SEVERAL INCHES ARE POSSIBLE ACROSS
THE SNOW BELT REGION OF VILAS COUNTY WITH LIGHTER AMOUNTS TO THE
SOUTH. UPPER TROUGH SWINGS ACROSS THE REGION THURSDAY...BRINGING A
CHANCE OF RAIN OR SNOW SHOWERS TO THE REMAINDER OF THE REGION.
THE BIG STORY BEHIND THIS TROUGH WILL BE THE COLD TEMPERATURES
ON FRIDAY. HIGH TEMPERATURES ON FRIDAY WILL ONLY BE IN THE MIDDLE 20S
TO LOWER 30S...OR SOME 10 TO 15 DEGREES BELOW NORMAL FOR THIS TIME OF
YEAR. VERY COLD TEMPERATURES ARE EXPECTED FRIDAY NIGHT WITH LOWS IN
THE SINGLE DIGITS AND TEENS.
SOME MODERATION IN TEMPERATURES IS EXPECTED ON SATURDAY. NEXT SYSTEM
TO AFFECT THE AREA SATURDAY NIGHT AND SUNDAY. SOME TIMING ISSUES NOTED
IF THIS SYSTEM WOULD OCCUR MORE SATURDAY NIGHT OR ON SUNDAY. THIS
COULD HAVE AN IMPACT ON PRECIPITATION TYPES IF IT SHOULD OCCUR MORE
ON SUNDAY. DRY CONDITIONS EXPECTED SUNDAY NIGHT INTO MONDAY NIGHT
AS HIGH PRESSURE MOVES ACROSS THE REGION. THERE IS A SMALL CHANCE
OF LIGHT RAIN ON TUESDAY...BUT CONFIDENCE IS LOW THAT THIS WOULD
OCCUR.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1222 PM CDT TUE MAR 24 2015
GOOD FLYING WEATHER THROUGH ABOUT THE MID-EVENING
HOURS...THEN CEILINGS AND VISIBILITIES WILL LOWER TO IFR OR LIFR
RANGE AFTER MIDNIGHT THROUGH EARLY TO MID-MORNING ON WEDNESDAY AS
LOW PRESSURE BRINGS WINTERY PRECIPITATION TO THE REGION. SNOW IS
EXPECTED NORTH AND WEST OF GREEN BAY WITH A MIX OF SNOW...SLEET AND
FREEZING RAIN CHANGING TO SNOW TO THE SOUTHEAST. ACCUMULATIONS OF 2
TO 4 INCHES WILL BE POSSIBLE FOR MOST LOCATIONS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM CDT WEDNESDAY FOR
WIZ030-031-035>040-045-048>050.
WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM CDT WEDNESDAY FOR
WIZ005-010>013-018>022-073-074.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......MPC