Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/24/14
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
258 PM CST SAT NOV 22 2014
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
WARM FNT WAS SITUATED WELL TO THE N OF AR THIS AFTN...WITH S/SELY
WINDS NOTED ACRS THE FA. WIDESPREAD SHRA/ISOLD TSRA HAS CONTD TO
AFFECT MUCH OF W-CNTRL AND NRN AR AS ANOTHER UPR LVL IMPULSE LIFTS
THRU THE REGION. PARTLY CLOUDY SKIES WERE NOTED OVR THE SERN HALF OF
THE AREA....WITH MID AFTN TEMPS IN THE 60S TO ARND 70.
THE PRIMARY WX MAKER OVR THE NEXT 24 TO 36 HRS WL BE THE MAIN UPR
LVL STORM SYS THAT WL CONT TO TRACK EWD INTO CNTRL TX TNGT AND
EVENTUALLY LIFT NEWD THRU AR ON SUN. SHRA/EMBEDDED TSRA WL BCM MORE
WIDESPREAD FM THE SW OVERNIGHT AND CONT ON SUN.
ONE FCST ISSUE CONTS TO BE THE ONSET/PROGRESS WITH THE MAIN WAVE OF
RAINFALL LATER TNGT AND SUN. THE HRRR MODEL HAS STAYED CONSISTENT
TODAY INDCG THE BULK OF THE RAIN WL NOT AFFECT THE FA FM THE SW
UNTIL AFT MIDNIGHT TNGT AND HAVE TRENDED POPS TOWARD THIS SOLUTION.
EXPECT WIDESPREAD SHRA/ISOLD TSRA SUN MRNG...SLOLY DCRSG FM THE SW
SUN AFTN AND EVENING AS THE STORM SYS LIFTS OUT OF THE AREA. LEFT
SOME SMALL RAIN CHCS IN FOR NRN AR SUN NGT AS THE MAIN UPR LVL TROF
SWINGS THRU THE AREA.
BREEZY WLY WINDS WL BRING COOLER AND MUCH DRIER AIR BACK TO THE MID
SOUTH FOR THE REST OF THE PD. SECONDARY CDFNT WL PASS THRU THE AREA
ON TUE...WITH A REINFORCING SHOT OF COOLER AIR.
&&
.LONG TERM...WEDNESDAY THROUGH SATURDAY
NEXT WEAK COLD FRONT IS DUE ON WEDNESDAY. AT THIS POINT...MOISTURE
LOOKS TOO LIMITED TO INCLUDE ANY POPS. ANOTHER WEAK FRONT IN THE
THURSDAY/FRIDAY TIME FRAME. WITH THESE REINFORCING SHOTS OF COOL
AIR...TEMPERATURES WILL REMAIN QUITE A BIT BELOW NORMAL THROUGH THE
END OF THE WEEK. JUST BEYOND THIS FORECAST PERIOD...THERE SHOULD BE
MORE CLOUDS AND PROBABLY SOME LOW POPS FOR AT LEAST A COUPLE OF DAYS.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...44 / LONG TERM...28
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
445 AM EST SAT NOV 22 2014
.DISCUSSION...
...ROUGH BOATING/BEACH CONDITIONS WITH INCREASING RAIN CHANCES...
CURRENT...
LARGE/STRONG HIGH PRESSURE RIDGE CENTERED OVER THE MIDDLE ATLC
REGION CONTINUES TO PRODUCE STOUT ONSHORE FLOW ACROSS ECFL AND THE
ADJCT ATLC. OLD FRONTAL BOUNDARY REMAINS QSTNRY TO OUR SOUTH...OVER
THE FL STRAITS. A WEAK MID LEVEL SHEAR AXIS EXTENDING FROM THE GOMEX
ACROSS THE CTRL PENINSULA IS SLOWLY LIFTING NWD. RAOB/PROFILER DATA
SHOW SWRLY FLOW AOA 6-7KFT PRODUCING WAA/ISENTROPIC UPGLIDE AND
EXTENSIVE MID LEVEL CLOUDS...ALONG WITH PASSING SPRINKLES OF LIGHT
RAIN. THERE REMAINS SOME RESIDUAL DRY AIR ABOVE H60 AND BELOW H80...
WITH HIGH MEAN RH VALUES IN BETWEEN.
TODAY/TONIGHT...
THE LARGE SURFACE HIGH TO THE NORTH WILL SHIFT EAST AND OFFSHORE
INTO THE ATLC OVER THE NEXT H24 AS THE BASE OF A MID LEVEL SHORT
WAVE TROUGH UPSTREAM MOVES OVER THE NERN GOMEX/GULF COAST...WITH
SOME MID LEVEL VORTICITY REACHING THE BIG BEND AREA. COMBINATION OF
THESE TWO FEATURES WILL CAUSE GRADUAL VEERING OF WINDS IN THE
SFC-H85 FROM ENE-E TO SE AND S...WITH BACKING OF THE H70-H50 FLOW
FROM WSW TO SW. THIS WILL CAUSE THE OLD BOUNDARY TO LIFT BACK NWD AS
A WARM FRONT....ADVECTING THE HIGHER MEAN PWAT AIR MASS LURKING TO
OUR SOUTH BACK NWD ACROSS OUR AREA. EXPECT ALREADY CLOUDY SKIES TO
REMAIN SO...THICKENING IN THE PROCESS. AREAS OF LIGHT RAIN WITH
EMBEDDED MODERATE TO HEAVIER SHOWERS WILL DEVELOP...WITH SOME BANDED
MARINE ACTIVITY ALSO LIKELY TO FACTOR INTO THE SENSIBLE WX ALONG THE
SPACE/TREASURE COASTS BY THIS AFTERNOON. BEST LIFT AND BETTER RAIN
CHANCES WILL LIFT NWD WITH THE FRONT...REACHING NORTH FL BY SUNDAY
MORNING.
OVERALL...CONDITIONS LOOK CLOUDY/DAMP BUT WARM. NOT A HUGE DIURNAL
RANGE GIVEN THE EXTENSIVE CLOUD COVER. MAXES GENERALLY IN THE M-U70S
WITH LOWS IN THE U60S-L70S.
SUN-MON...
AN UNSETTLED WX PD TO START THE UPCOMING WEEK. THE LARGE HI PRES
RIDGE BLANKETING THE ERN CONUS WILL PUSH INTO THE ATLC AS A DVLPG
STORM SYSTEM OVER THE PAC NW DRIFTS ALONG THE CANADIAN BORDER. THE
H30-H20 JET PATTERN OVER THE ERN PAC IS ALMOST PERFECTLY ZONAL...
WITH A 150KT MAX THAT WILL SERVE TO STRENGTHEN THE NEW SFC LOW AS IT
CROSSES THE CANADIAN ROCKIES. THE JET STREAK WILL AMPLIFY AS PUSHES
INTO THE PAC NW...BUT EXISTING ZONAL FLOW WILL PUSH THE STORM SYSTEM
TOO FAR TO THE EAST TOO QUICKLY FOR IT TO DROP MUCH BELOW THE NRN
PLAINS BEFORE IT GETS CAUGHT UP BY THE LIFTING SIDE OF THE UPR LVL
SHORT WAVE AND BOMBS OUT OVER THE GREAT LAKES BY DAYBREAK MON. BY
THEN...THE AFOREMENTIONED HI PRES RIDGE WILL HAVE ANCHORED ITSELF
OVER THE W ATLC...WHERE IT WILL DEFLECT THE STORM SYSTEM INTO ERN
CANADA BY DAYBREAK TUE. THE SRN EXTENT OF THE TRAILING COLD FRONT
WILL BE LEFT TO ITS OWN MOMENTUM FOR FORWARD PROGRESS...WHICH WILL
BE SLOW GIVEN THE POSITION OF THE ATLC RIDGE.
H100-H70 WINDS WILL VEER TO THE S/SW THRU THE DAY ON SUN AS THE
RIDGE BUILDS OFFSHORE...WHILE AN H85-H50 ANTICYCLONE OVER THE NRN
BAHAMAS WILL MAINTAIN AN EXISTING W/SW FLOW THRU THE MID LYRS. THIS
WILL RESULT IN STRONG LOW/MID LVL ISENTROPIC LIFT IN THE PRESENCE OF
LOW LVL MOISTURE ADVECTION. MID LVL MOISTURE...HOWEVER...WILL BE ON
THE WANE AS LATEST RUC ANALYSIS SHOWS H85-H50 MEAN RH VALUES
DECREASING FROM 60-70PCT OVER CENTRAL/SOUTH FL...TO BLO 50PCT OVER
THE NW CARIB.
THE COMBINATION OF LOW LVL MOISTURE AND MID LVL DRY AIR WILL SET THE
STAGE FOR TSTM DEVELOPMENT THRU MON...ESPECIALLY AS THE STORM SYSTEM
DVLPS AND TRIES TO CRANK A NEW COLD FRONT THROUGH THE DEEP SOUTH.
HOWEVER...PROGRESS OF THE FRONT WILL BE SLOW AS THE ATLC RIDGE
BLOCKS ITS ADVANCE WHILE THE THE STORM SYSTEM LIFTS INTO CANADA AND
ABANDONS THE SRN EXTENT OF ITS TROF. A BRISK S/SW BREEZE WILL
PREVAIL THRU THE H100-H70...ADDING WARM AIR ADVECTION TO THE
PICTURE. ONE MAJOR FACTOR THAT WILL WORK AGAINST A STRONG/SVR WX
EVENT WILL BE THE THERMAL PROFILE. THE -10C H50 ISOTHERM IS
CURRENTLY LOCATED N OF THE I-4 CORRIDOR AND WILL ONLY LIFT FURTHER
NORTH IN THE FACE OF THE MID LVL SWRLY FLOW. H70-H50 LAPSE RATES
OVER THE CENTRAL GOMEX ARE RUNNING A RESPECTABLE 6.5-7.0C/KM...BUT A
PALTRY AOB 5C/KM THRU THE H85-H70 LYR.
WILL OPT FOR CHC/LIKELY SHRAS AND A SLGT CHC OF TSTMS ON SUN...
HIGHEST OVER THE NRN CWA DUE TO A DEEPER MOISTURE PROFILE. POPS
DECREASING TO CHC/SLGT CHC SUN NIGHT AS DRIER AIR AND THE LOSS OF
DIURNAL HEATING SHOULD CHOKE OFF MOST OF ANY STORM ACTIVITY. AS THE
FRONT STALLS OVER THE FL BIG BEND/ERN PANHANDLE...THE DEEPEST
MOISTURE WILL POOL TO THE N...WHILE MID/UPR LVL DEBRIS CLOUDS
DISTURB SFC HEATING/LOW LVL DESTABILIZATION. POPS WILL RANGE FROM
40PCT FROM SRN LAKE/ORANGE/NRN BREVARD NWD...TO 20PCT N/E FROM LAKE
OKEECHOBEE. SRLY FLOW WILL PUSH TEMPS WELL ABV AVG...MAXES INTO THE
L/M80S AND MIN IN THE M/U60S.
TUE-FRI...
WET WX PATTERN WILL CONTINUE THRU MID WEEK AS THE UPR LVL JET
PATTERN BECOMES HIGHLY AMPLIFIED ACRS THE CONUS. JET ENERGY OVER THE
W PAC IS PLENTIFUL WITH H25 WINDS ARND 150KTS ENCROACHING ON THE
OREGON COAST. AS THIS JET DIGS INTO THE NW CONUS AND ITS ENERGY IS
TRANSLATED DOWNSTREAM...THE LIFTING JET OVER THE ERN CONUS WILL
STRENGTHEN CONSIDERABLY...THE 00Z GFS MODEL SUGGESTING MAX SPEEDS
ARND 200KTS DVLPG OVER NEW ENGLAND LATE TUE NIGHT WITH THE 150KT
ISOTACH TRAILING INTO THE DEEP SOUTH. THE STRONG UPR LVL DIVERGENCE
GENERATED BY THIS JET WILL INDUCE A NEW AREA OF LOW PRESSURE N OF
THE BAHAMA BANK DAYBREAK WED ALONG OR JUST AHEAD OF THE STALLED
FRONTAL BNDRY.
AS THE LOW DLVPS AND LIFTS UP THE ERN SEABOARD...IT WILL DRAG THE
FRONT CLEAR OF THE STATE...ALLOWING A DRY WX PD TO PREVAIL THRU THE
LATTER HALF OF THE WEEK. THE 22/00Z ECMWF INDICATES THIS HAPPENING
BY 00Z THU...22/00Z GFS ABOUT 12HRS SLOWER. WITH THE FRONT SAGGING
INTO CENTRAL FL ON TUE...WILL NEED TO PAINT THE AREA WITH LKLY POPS.
POPS DIMINISHING FROM THE W ON WED BUT REMAINING BTWN 30-50PCT...
20-30PCT...LINGERING ALONG THE COAST/LAKE OKEECHOBEE THRU WED NIGHT.
DRY WX FCST THU-FRI.
TUE TEMPS WILL REFLECT THE POSITION OF THE FRONT...MAXES RANGING
FROM THE L70S N OF I-4 TO THE L80S E OF LAKE OKEECHOBEE...MINS FROM
THE L50S TO L60S RESPECTIVELY. COOL/DRY AIR ADVECTION BEHIND THE
FRONT WILL DROP MAX TEMPS INTO THE 60S AREAWIDE ON WED...MINS INTO
THE L40S-L50S WED NIGHT. LITTLE TEMP CHANGE EXPECTED THRU FRI AS A
SLOW MOVING HI PRES BEHIND THE FRONT WILL MAINTAIN A STEADY N/NW
FLOW.
&&
.AVIATION...
VFR WITH CIGS OVC-BKN040-060 MLB-SUA AND OVC080-110 KTIX-KMCO NWD.
CIGS WILL LOWER/THICKEN WITH MVFR CONDS DEVELOPING/SPREADING NWD
FROM SUA-FPR. EVENTUALLY EXPECT TO SEE SOME IFR TO LOW END MVFR CIGS
BKN-OVC007-015 BECOME PREVALENT STARTING IN THE 22Z-02Z TIME FRAME.
&&
.MARINE...
TODAY/TONIGHT...THE STRONG HIGH TO THE NORTH WILL MAINTAIN THE TIGHT
LOCAL PGRAD WITH WINDS 20-25KT AND SEAS ALREADY A SOLID 7-9FT ACROSS
THE ENTIRETY OF THE MAOR. WNAWAVE GUIDANCE IS UNDERDOING CURRENT
CONDITIONS BY A GOOD 1-2FT...AND THE NWPS LOOKS MUCH CLOSER TO
REALITY. SEAS UP TO 8FT NEAR SHORE AND 10FT OFFSHORE. HEIGHT OF THE
BREAKERS IN THE SURF ZONE LOOK TO BE A LITTLE SHORT OF HIGH SURF ADV
CRITERIA...NEVERTHELESS LARGE BREAKING WAVES/HIGH SEAS WILL PRODUCE
VERY HAZARDOUS CONDITIONS FOR SMALL CRAFT...AND DANGEROUS SWIMMING/
SURF FOR BEACH GOERS...WITH NUMEROUS STRONG RIPS AND POSSIBLE MINOR
EROSION AROUND THE TIME OF HIGH TIMES.
SUN-MON...UNFAVORABLE CONDITIONS TO START THE WEEK AS A MODERATE TO
FRESH S/SE BREEZE CONTINUES THRU THE DAY ON SUN...SEAS 5-7FT
NEARSHORE AND 8-10FT OFFSHORE. SFC/BNDRY LYR WINDS BCMG GENTLE TO
MODERATE S/SW ON MON AS A COLD FRONT STALLS OVER THE FL PANHANDLE...
SEAS SUBSIDING TO 3-4FT NEARSHORE AND 5-7FT OFFSHORE.
TUE-TUE NIGHT...COLD FRONT WILL SAG INTO CENTRAL FL...RESULTING IN
VRBL WINDS ACRS THE LCL ATLC...S/SE 10-15KTS AHEAD OF THE FRONT...
N/NW 5-10KTS BEHIND IT. WINDS WILL FRESHEN OUT OF THE N/NW AFT
SUNSET AS A WEAK LOW PRES SYSTEM DVLPS N OF THE BAHAMAS...MODERATE
TO FRESH N OF SEBASTIAN INLET...GENTLE TO MODERATE S OF THE INLET.
SEAS 3-5FT N OF THE INLET AND 2-4FT S OF THE INLET THRU THE
DAY...BUILDING TO 5-7FT N OF THE INLET AND 3-5FT S OF THE INLET AFT
SUNSET.
WED-WED NIGHT...FRESH TO STRONG NW BREEZE WILL DVLP SHORTLY AFT
SUNRISE AS THE LOW PRES SYSTEM LIFTS N AND DRAGS THE COLD FRONT THRU
THE ATLC WATERS. SEAS BUILDING TO 6-8FT NEARSHORE AND 7-9FT OFFSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 73 69 81 68 / 50 60 60 40
MCO 76 67 83 68 / 50 60 60 40
MLB 76 73 82 70 / 50 50 50 30
VRB 77 74 82 70 / 50 50 50 30
LEE 75 66 83 68 / 50 60 60 40
SFB 75 67 83 67 / 50 60 60 40
ORL 76 68 83 68 / 50 60 60 40
FPR 78 74 82 70 / 50 50 40 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 PM EST SUNDAY FOR COASTAL WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20 NM-
COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20
NM-COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM-WATERS FROM FLAGLER BEACH TO
VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS
FROM SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE-
WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET
20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM/AVIATION...CRISTALDI
LONG TERM/IMPACT WX...BRAGAW
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
350 AM EST SAT NOV 22 2014
.DISCUSSION...
...ROUGH BOATING/BEACH CONDITIONS WITH INCREASING RAIN CHANCES...
CURRENT...
LARGE/STRONG HIGH PRESSURE RIDGE CENTERED OVER THE MIDDLE ATLC
REGION CONTINUES TO PRODUCE STOUT ONSHORE FLOW ACROSS ECFL AND THE
ADJCT ATLC. OLD FRONTAL BOUNDARY REMAINS QSTNRY TO OUR SOUTH...OVER
THE FL STRAITS. A WEAK MID LEVEL SHEAR AXIS EXTENDING FROM THE GOMEX
ACROSS THE CTRL PENINSULA IS SLOWLY LIFTING NWD. RAOB/PROFILER DATA
SHOW SWRLY FLOW AOA 6-7KFT PRODUCING WAA/ISENTROPIC UPGLIDE AND
EXTENSIVE MID LEVEL CLOUDS...ALONG WITH PASSING SPRINKLES OF LIGHT
RAIN. THERE REMAINS SOME RESIDUAL DRY AIR ABOVE H60 AND BELOW H80...
WITH HIGH MEAN RH VALUES IN BETWEEN.
TODAY/TONIGHT...
THE LARGE SURFACE HIGH TO THE NORTH WILL SHIFT EAST AND OFFSHORE
INTO THE ATLC OVER THE NEXT H24 AS THE BASE OF A MID LEVEL SHORT
WAVE TROUGH UPSTREAM MOVES OVER THE NERN GOMEX/GULF COAST...WITH
SOME MID LEVEL VORTICITY REACHING THE BIG BEND AREA. COMBINATION OF
THESE TWO FEATURES WILL CAUSE GRADUAL VEERING OF WINDS IN THE
SFC-H85 FROM ENE-E TO SE AND S...WITH BACKING OF THE H70-H50 FLOW
FROM WSW TO SW. THIS WILL CAUSE THE OLD BOUNDARY TO LIFT BACK NWD AS
A WARM FRONT....ADVECTING THE HIGHER MEAN PWAT AIR MASS LURKING TO
OUR SOUTH BACK NWD ACROSS OUR AREA. EXPECT ALREADY CLOUDY SKIES TO
REMAIN SO...THICKENING IN THE PROCESS. AREAS OF LIGHT RAIN WITH
EMBEDDED MODERATE TO HEAVIER SHOWERS WILL DEVELOP...WITH SOME BANDED
MARINE ACTIVITY ALSO LIKELY TO FACTOR INTO THE SENSIBLE WX ALONG THE
SPACE/TREASURE COASTS BY THIS AFTERNOON. BEST LIFT AND BETTER RAIN
CHANCES WILL LIFT NWD WITH THE FRONT...REACHING NORTH FL BY SUNDAY
MORNING.
OVERALL...CONDITIONS LOOK CLOUDY/DAMP BUT WARM. NOT A HUGE DIURNAL
RANGE GIVEN THE EXTENSIVE CLOUD COVER. MAXES GENERALLY IN THE M-U70S
WITH LOWS IN THE U60S-L70S.
SUN-MON...
AN UNSETTLED WX PD TO START THE UPCOMING WEEK. THE LARGE HI PRES
RIDGE BLANKETING THE ERN CONUS WILL PUSH INTO THE ATLC AS A DVLPG
STORM SYSTEM OVER THE PAC NW DRIFTS ALONG THE CANADIAN BORDER. THE
H30-H20 JET PATTERN OVER THE ERN PAC IS ALMOST PERFECTLY ZONAL...
WITH A 150KT MAX THAT WILL SERVE TO STRENGTHEN THE NEW SFC LOW AS IT
CROSSES THE CANADIAN ROCKIES. THE JET STREAK WILL AMPLIFY AS PUSHES
INTO THE PAC NW...BUT EXISTING ZONAL FLOW WILL PUSH THE STORM SYSTEM
TOO FAR TO THE EAST TOO QUICKLY FOR IT TO DROP MUCH BELOW THE NRN
PLAINS BEFORE IT GETS CAUGHT UP BY THE LIFTING SIDE OF THE UPR LVL
SHORT WAVE AND BOMBS OUT OVER THE GREAT LAKES BY DAYBREAK MON. BY
THEN...THE AFOREMENTIONED HI PRES RIDGE WILL HAVE ANCHORED ITSELF
OVER THE W ATLC...WHERE IT WILL DEFLECT THE STORM SYSTEM INTO ERN
CANADA BY DAYBREAK TUE. THE SRN EXTENT OF THE TRAILING COLD FRONT
WILL BE LEFT TO ITS OWN MOMENTUM FOR FORWARD PROGRESS...WHICH WILL
BE SLOW GIVEN THE POSITION OF THE ATLC RIDGE.
H100-H70 WINDS WILL VEER TO THE S/SW THRU THE DAY ON SUN AS THE
RIDGE BUILDS OFFSHORE...WHILE AN H85-H50 ANTICYCLONE OVER THE NRN
BAHAMAS WILL MAINTAIN AN EXISTING W/SW FLOW THRU THE MID LYRS. THIS
WILL RESULT IN STRONG LOW/MID LVL ISENTROPIC LIFT IN THE PRESENCE OF
LOW LVL MOISTURE ADVECTION. MID LVL MOISTURE...HOWEVER...WILL BE ON
THE WANE AS LATEST RUC ANALYSIS SHOWS H85-H50 MEAN RH VALUES
DECREASING FROM 60-70PCT OVER CENTRAL/SOUTH FL...TO BLO 50PCT OVER
THE NW CARIB.
THE COMBINATION OF LOW LVL MOISTURE AND MID LVL DRY AIR WILL SET THE
STAGE FOR TSTM DEVELOPMENT THRU MON...ESPECIALLY AS THE STORM SYSTEM
DVLPS AND TRIES TO CRANK A NEW COLD FRONT THROUGH THE DEEP SOUTH.
HOWEVER...PROGRESS OF THE FRONT WILL BE SLOW AS THE ATLC RIDGE
BLOCKS ITS ADVANCE WHILE THE THE STORM SYSTEM LIFTS INTO CANADA AND
ABANDONS THE SRN EXTENT OF ITS TROF. A BRISK S/SW BREEZE WILL
PREVAIL THRU THE H100-H70...ADDING WARM AIR ADVECTION TO THE
PICTURE. ONE MAJOR FACTOR THAT WILL WORK AGAINST A STRONG/SVR WX
EVENT WILL BE THE THERMAL PROFILE. THE -10C H50 ISOTHERM IS
CURRENTLY LOCATED N OF THE I-4 CORRIDOR AND WILL ONLY LIFT FURTHER
NORTH IN THE FACE OF THE MID LVL SWRLY FLOW. H70-H50 LAPSE RATES
OVER THE CENTRAL GOMEX ARE RUNNING A RESPECTABLE 6.5-7.0C/KM...BUT A
PALTRY AOB 5C/KM THRU THE H85-H70 LYR.
WILL OPT FOR CHC/LIKELY SHRAS AND A SLGT CHC OF TSTMS ON SUN...
HIGHEST OVER THE NRN CWA DUE TO A DEEPER MOISTURE PROFILE. POPS
DECREASING TO CHC/SLGT CHC SUN NIGHT AS DRIER AIR AND THE LOSS OF
DIURNAL HEATING SHOULD CHOKE OFF MOST OF ANY STORM ACTIVITY. AS THE
FRONT STALLS OVER THE FL BIG BEND/ERN PANHANDLE...THE DEEPEST
MOISTURE WILL POOL TO THE N...WHILE MID/UPR LVL DEBRIS CLOUDS
DISTURB SFC HEATING/LOW LVL DESTABILIZATION. POPS WILL RANGE FROM
40PCT FROM SRN LAKE/ORANGE/NRN BREVARD NWD...TO 20PCT N/E FROM LAKE
OKEECHOBEE. SRLY FLOW WILL PUSH TEMPS WELL ABV AVG...MAXES INTO THE
L/M80S AND MIN IN THE M/U60S.
TUE-FRI...
UPDATE TO FOLLOW.
&&
.AVIATION...
VFR WITH CIGS OVC-BKN040-060 MLB-SUA AND OVC080-110 KTIX-KMCO NWD.
CIGS WILL LOWER/THICKEN WITH MVFR CONDS DEVELOPING/SPREADING NWD
FROM SUA-FPR. EVENTUALLY EXPECT TO SEE SOME IFR TO LOW END MVFR CIGS
BKN-OVC007-015 BECOME PREVALENT STARTING IN THE 22Z-02Z TIME FRAME.
&&
.MARINE...
TODAY/TONIGHT...THE STRONG HIGH TO THE NORTH WILL MAINTAIN THE TIGHT
LOCAL PGRAD WITH WINDS 20-25KT AND SEAS ALREADY A SOLID 7-9FT ACROSS
THE ENTIRETY OF THE MAOR. WNAWAVE GUIDANCE IS UNDERDOING CURRENT
CONDITIONS BY A GOOD 1-2FT...AND THE NWPS LOOKS MUCH CLOSER TO
REALITY. SEAS UP TO 8FT NEAR SHORE AND 10FT OFFSHORE. HEIGHT OF THE
BREAKERS IN THE SURF ZONE LOOK TO BE A LITTLE SHORT OF HIGH SURF ADV
CRITERIA...NEVERTHELESS LARGE BREAKING WAVES/HIGH SEAS WILL PRODUCE
VERY HAZARDOUS CONDITIONS FOR SMALL CRAFT...AND DANGEROUS SWIMMING/
SURF FOR BEACH GOERS...WITH NUMEROUS STRONG RIPS AND POSSIBLE MINOR
EROSION AROUND THE TIME OF HIGH TIMES.
SUN-MON...UNFAVORABLE CONDITION TO START THE WEEK AS A MODERATE TO
FRESH S/SE BREEZE CONTINUES THRU THE DAY ON SUN...SEAS 5-7FT
NEARSHORE AND 8-10FT OFFSHORE. SFC/BNDRY LYR WINDS BCMG GENTLE TO
MODERATE S/SW ON MON AS A COLD FRONT STALLS OVER THE FL PANHANDLE...
SEAS SUBSIDING TO 3-4FT NEARSHORE AND 5-7FT OFFSHORE.
TUE-WED...UPDATE TO FOLLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 73 69 81 68 / 50 60 60 40
MCO 76 67 83 68 / 50 60 60 40
MLB 76 73 82 70 / 50 50 50 30
VRB 77 74 82 70 / 50 50 50 30
LEE 75 66 83 68 / 50 60 60 40
SFB 75 67 83 67 / 50 60 60 40
ORL 76 68 83 68 / 50 60 60 40
FPR 78 74 82 70 / 50 50 40 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 PM EST SUNDAY FOR COASTAL WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20 NM-
COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20
NM-COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM-WATERS FROM FLAGLER BEACH TO
VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS
FROM SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE-
WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET
20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM/AVIATION...CRISTALDI
LONG TERM/IMPACT WX...BRAGAW
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
913 PM CST SUN NOV 23 2014
.UPDATE...
832 PM CST
FOR EVENING UPDATE...
ONLY MINOR ADJUSTMENTS MADE TO GOING FORECAST TONIGHT...PRIMARILY
TO ADD AREAS OF FOG ALONG THE LAKE AND ACROSS PARTS OF NORTHERN
ILLINOIS OVERNIGHT.
COMPLEX UPPER PATTERN CONTINUES TO EVOLVE ACROSS THE REGION THIS
EVENING AS A SERIES OF MID-LEVEL SHORT WAVES ROTATE THROUGH THE
LARGER-SCALE UPPER TROUGH OVER THE CENTRAL AND EASTERN PARTS OF
NORTH AMERICA. AT THE SURFACE...AN AREA OF LOW PRESSURE WITH A
COUPLE OF INDIVIDUAL LOW CENTERS WAS OVER IL AT 02Z/8 PM CST...
WITH STRONG (6 MB/3 HRS) SURFACE PRESSURE FALLS ACROSS MUCH OF THE
MIDWEST AND SOUTHERN GREAT LAKES REGION. THE LATEST MODEL GUIDANCE
CONTINUES TO CONSOLIDATE A SURFACE LOW OVER FAR NORTHEAST IL OVER
THE NEXT SEVERAL HOURS...LIFTING IT NORTHEAST AND DEEPENING IT
OVERNIGHT AND EARLY MONDAY AS IT PULLS AWAY FROM THE AREA.
REGIONAL RADAR MOSAICS INDICATE A LARGE SHIELD OF RAIN ACROSS THE
EASTERN HALF OF ILLINOIS AND MUCH OF THE GREAT LAKES REGION
PRIMARILY ASSOCIATED WITH A STRONG SHORT WAVE LIFTING NORTHEAST
CROSS THE OHIO VALLEY. ANOTHER AREA OF RAIN AND EMBEDDED THUNDER
WS NOTED BACK ACROSS THE LOWER MISSOURI VALLEY WITH ANOTHER STRONG
WAVE. RAIN MAY TAPER OFF TO OCCASIONAL LIGHT RAIN OR DRIZZLE
ACROSS SOME AREAS WITH A BIT OF A BREAK BETWEEN THE SOLID RAIN
WITH THESE SYSTEMS...THOUGH A PERSISTENT DRIZZLE WILL LIKELY MAKE
IT SEEM LIKE ITS RAINING MOST OF THE TIME ANYWAYS. IN ADDITION TO
THE RAIN...HIGH DEWPOINT AIR WRAPPING NORTHWESTWARD AHEAD OF THE
SURFACE LOW WAS PRODUCING FOG ACROSS SOUTHERN LAKE MICHIGAN WHERE
LAKE WATER TEMPS WERE IN THE MID-40S...AND AFFECTING AREAS ALONG
THE ILLINOIS SHORE. WILL ALSO LIKELY SEE SOME PATCHES OF FOG WHERE
PRECIP DIMINISHES TO DRIZZLE OVERNIGHT...ESPECIALLY IN BAGGY
PRESSURE GRADIENT AND WEAKER WINDS IN VICINITY OF THE SURFACE LOW.
WEST WINDS WILL KICK IN EARLY MONDAY MORNING AS THE LOW PULLS
NORTH AND A COLD FRONT PUSHES EAST ACROSS THE AREA. THIS SHOULD
HELP PUSH SOME OF THE FOG OUT EARLY IN THE MORNING. COLDER AIR AND
WIND GUSTS TO 40 MPH BECOME AN ISSUE DURING THE DAY...ALONG WITH
PRECIPITATION CHANGE FROM LIQUID TO FROZEN AS THE COLUMN COOLS.
POTENTIAL FOR A PERIOD OF MODERATE/LOCALLY HEAVY WET SNOW EXISTS
OVER NORTH CENTRAL/PARTS OF NORTHEAST IL WHERE SOUTHERN PERIPHERY
OF DEFORMATION BAND PASSES. CONFIDENCE NOT SUPER HIGH WITH AMOUNTS
AT THIS POINT...THOUGH NO CHANGES TO WSW HEADLINES AT THIS TIME.
RATZER
&&
.SHORT TERM...
244 PM CST
UNSEASONABLY WARM/MOIST AIRMASS CONTINUES TO ADVECT NORTH ACROSS THE
REGION THIS AFTN...AND LOOKS TO CONTINUE THROUGH TONIGHT. THE MAIN
CONCERN FOR THE OVERNIGHT WILL BE ON RAINFALL TOTALS AND IF THIS
WILL POSE ANY HYDRO CONCERNS.
STRONG WARM AIR ADVECTION THIS AFTERNOON HAS ALLOWED SFC TEMPS TO
WARM INTO THE 50S ACROSS MUCH OF THE FORECAST AREA WITH DEW POINTS
APPROACHING THE UPPER 40S/ARND 50. THE AXIS OF THE HEAVIER RAINFALL
THIS AFTN HAS SHIFTED TO THE NORTHWEST AND STRETCHES FROM CENTRAL
WISC SOUTHWEST THROUGH FAR EASTERN IOWA. HAVE NUDGED TEMPS OVERNIGHT
UP A TAD...AND EXPECT TEMPS TO REMAIN NEARLY CONSISTENT UNTIL CLOSER
TO DAYBREAK MON WHEN THE FRONTAL BOUNDARY BEGINS TO APPROACH THE
NORTHWEST CWFA. GUIDANCE CONTINUES TO SUGGEST THE LOW DROPPING
SOUTHEAST ACROSS THE UPPER MIDWEST AND THE SECONDARY ONE LIFTING
NORTH FROM THE SOUTHWEST...WILL CONVERGE ACROSS SOUTHWEST LOWER
MICHIGAN JUST BEFORE DAYBREAK MON. THE COLD FRONT WILL BE NEARING
THE WESTERN CWFA ARND DAYBREAK...AND STEADILY SLIDE EAST THRU THE
MORNING. ASSOCIATED WILL BE A SHARP THERMAL TROUGH THAT WILL CAUSE
TEMPS TO STEADILY FALL THROUGHOUT THE MORNING/AFTN. SO THE DAY MAY
START MILD...BUT BY MIDDAY THAT WILL CERTAINLY NOT BE THE CASE WITH
TEMPS GENERALLY IN THE UPR 20S/LOW 30S. PRECIP WILL BE QUICKLY
TRANSITIONING OVER FROM RAIN TO SNOW.
AS THE SNOW BEGINS MIDDAY ACROSS THE NORTHWEST...GUIDANCE HAS BEEN
RELATIVELY CONSISTENT THAT AT ONSET RATIOS WILL HOVER ARND 8:1 TO
9:1...THEN AS THE COLDER AIR ADVECTS IN THOSE RATIOS SHUD STEADILY
CLIMB TO 14:1-17:1 BY LATE MON AFTN/EARLY EVE. COMPOUNDING THE SETUP
WILL BE STEADILY INCREASING PRESSURE GRADIENT THAT WILL CREATE GUSTY
WINDS NEARING 30-35MPH. THERE IS A NARROW WINDOW WHERE SNOWFALL
RATES COULD NEAR 1-2"/HR FOR A COUPLE HOURS...MAINLY BETWEEN 2-4PM
CST AND MAINLY WEST OF A LASALLE TO CRYSTAL LAKE LINE. HAVE BUMPED
SNOW TOTALS UP TO 2-4" AND COULD SEE IN PORTIONS OF WINNEBAGO COUNTY
3-5" CLOSER TO THE WISC STATELINE IN NORTHERN WINNEBAGO COUNTY.
ELSEWHERE SNOW WILL BEGIN TO ACCUMULATE...BUT EXPECTING MUCH LESS
WITH PERHAPS AN INCH IN CHICAGO AND LESSER TOTALS FURTHER SOUTH.
500MB TROUGH AXIS PIVOTS OVERHEAD MON EVE...AND WILL SLOWLY BRING AN
END TO THE ACCUMULATING SNOW. THE BETTER MOISTURE WILL QUICKLY PEEL
OFF TO THE NORTHEAST LATE MON NGT...HOWEVER ENOUGH OMEGA/MOISTURE TO
KEEP MENTION OF LGT SNOW SHOWERS MON NGT.
OVERNIGHT LOWS MON DIP FALL TO THE LOW 20S TO MID 20S IN THE
SOUTHEAST.
BEACHLER
&&
.LONG TERM...
244 PM CST
TUESDAY THROUGH WEDNESDAY...
LARGE MID-LVL TROUGH WILL BE IN PLACE TUE/WED WITH A WEAK SFC RIDGE
LIFTING NORTH AND BRINGING A GRADUAL EROSION TO THE CLOUDS TUE
NGT/WED. UNFORTUNATELY THIS MAY BE SHORT LIVED AS GUIDANCE SUGGESTS
A QUICK SHORTWAVE WILL DROP SOUTH FROM CENTRAL CANADA INTO THE
NORTHERN PLAINS EARLY WED...AND APPROACH THE FORECAST AREA MIDDAY
WED. THIS SYSTEM COULD BRING ANOTHER PERIOD OF LIGHT SNOW WITH SOME
MINOR ACCUMULATIONS.
TEMPS TUE WILL REMAIN IN THE 20S...HOWEVER WITH SOME THINNING IN THE
CLOUDS FOR WED TEMPS COULD REBOUND INTO THE LOW/MID 30S. BUT IT WILL
HINGE UPON THE ARRIVAL OF THE NEXT MID-LVL WAVE AND CLOUD COVER.
THURSDAY THROUGH SATURDAY...
ENSEMBLES IN THE LONGER TERM CONTINUES TO POINT TOWARDS A TROUGH
CARVED OUT ACROSS THE GREAT LAKES/TENN VALLEY FOR THE SECOND HALF OF
THE WEEK...AND THEN BEGINS TO FLATTEN FOR THE SECOND HALF OF THE
WEEKEND. AT THIS TIME GUIDANCE SUGGESTS DRY AIR AND A SFC RIDGE
OVERHEAD FOR THANKSGIVING DAY. TEMPS WILL GENERALLY BE IN THE 20S
FOR THE BULK OF THE EXTENDED.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* IFR CIGS PERSIST THROUGH THE NIGHT AND MAY LOWER TO 300-400 FT.
* STEADY RAIN TURNS TO DRIZZLE OVERNIGHT WITH STEADIER RAIN
RETURNING AFTER DAYBREAK/MID MORNING.
* IFR VSBY LIKELY OVERNIGHT. WILL NEED TO MONITOR FOR SUB 1SM
VSBY.
* SOUTHEAST WINDS TURNING SOUTHWEST OR EVEN LIGHT/VARIABLE LATE
THIS EVENING.
* WINDS SHIFT WEST MONDAY MORNING THEN SOUTHWEST WITH GUSTS TO 30
KT WITH A PERIOD OF 35 KT GUSTS POSSIBLE MIDDAY/EARLY AFTERNOON.
* RAIN CHANGES TO SNOW MIDDAY/EARLY AFTERNOON...SOME LIGHT
ACCUMULATION POSSIBLE...ESPECIALLY LATER IN THE DAY.
MDB
//DISCUSSION...UPDATED 03Z...
RAIN CONTINUES TO MOVE ACROSS THE TERMINALS WITH BACK EDGE
MARCHING NORTHEAST ACROSS CENTRAL IL. SHOULD SEE FAIRLY STEADY
STATE CONDITIONS FOR A FEW HOURS BEFORE RAIN TRANSITIONS TO
DRIZZLE. WINDS WILL ALSO BE WEAKENING AND BECOMING MORE VARIABLE
FROM THE SOUTH AS LOW PRESSURE MOVES OVER THE AREA. THIS AND THE
DRIZZLE SUGGEST THAT VSBY WILL LOWER AND THIS IS WHAT IS OCCURRING
TO THE WEST SO HAVE LOWERED VSBY SLIGHTLY OVERNIGHT. AREAS OF
1/4-3/4SM ARE NOT OUT OF THE QUESTION SO FURTHER LOWERING MAY BE
NEEDED GOING TOWARD DAYBREAK. OTHERWISE HAVE ADJUSTED TIMING OF
RAIN/SNOW TO SNOW CHANGE OVER BASED ON LATEST TRENDS AND INCOMING
FORECAST GUIDANCE. AM STILL SEEING SUPPORT FOR DECREASING MID
LEVEL MOISTURE MIDDAY/EARLY AFTERNOON SUGGESTING LESS IN THE WAY
OF SNOW COVERAGE FOR A TIME BEFORE ADDITIONAL FORCING AND MOISTURE
PUSH IN LATER IN THE DAY OR EVEN TOWARDS MID EVENING. CONFIDENCE
IN PRECIP TRENDS DURING THE DAY IS STILL LOW BUT INCREASING.
FURTHER ADJUSTMENTS WILL LIKELY BE NEEDED WITH OVERNIGHT UPDATES.
FROM 00Z...
HAVE GOOD CONFIDENCE IN THE FORECAST THROUGH TONIGHT BUT LOWER
CONFIDENCE MONDAY...ESPECIALLY IN TERMS OF RAIN/SNOW TRENDS. LOW
PRESSURE TAKING SHAPE OVER SW MISSOURI THIS EVENING WILL QUICKLY
TRACK NORTHEAST ACROSS THE AREA EARLY TONIGHT. SOUTHEAST WINDS
WILL TURN SOUTHWEST AND PROBABLY DIMINISH IN SPEED AS THE LOW
PASSES SO LIGHT/VARIABLE CONDITIONS MAY OCCUR FOR A TIME
OVERNIGHT. RAIN CONTINUES TO STREAM NORTHWARD ACROSS THE TERMINALS
WITH RFD NEAR THE WESTERN EDGE. DRIER MID LEVEL AIR WILL WRAP IN
INTO THE OVERNIGHT SO A TRANSITION TO LIGHTER RAIN OR JUST DRIZZLE
IS EXPECTED. THIS WILL BE UNDERWAY AT RFD THIS EVENING. IFR CIGS
WILL LOWER SOMEWHAT WITH TIME WHILE VSBY IN THE RAIN VARIES
BETWEEN 2 AND 6SM. DRIZZLE TONIGHT WILL LIKELY ALLOW VSBY TO FALL
TO IFR AND MAY NEED TO CARRY SUB 1SM VSBY FOR A PERIOD.
A SHARP COLD FRONT WORKS ACROSS THE TERMINALS AFTER DAYBREAK
SHIFTING WINDS TO WEST AND ALLOWING THEM TO RAMP UP. GUSTS WILL
PUSH 30 KT BY MID/LATE MORNING WITH 35 KT OR SO POSSIBLE AT TIMES
INTO EARLY AFTERNOON. THE DIRECTION WILL LIKELY BECOME A LITTLE
MORE SOUTHWESTERLY INTO THE AFTERNOON AS WELL. ANOTHER PERIOD OF
PRECIP LOOKS LIKELY DURING THE MORNING INTO MIDDAY WHICH WILL
TRANSITION TO SNOW AS COLDER AIR ARRIVES. LATEST FORECAST GUIDANCE
IS SUGGESTING THAT HIGHER LEVEL MOISTURE WANES DURING THE
AFTERNOON LEADING TO LIGHTER PRECIP OR EVEN MORE DRIZZLE. GUIDANCE
HAS NOT BEEN TERRIBLY CONSISTENT ON DETAILS SO CONFIDENCE IS ON
THE LOW SIDE. EITHER WAY RFD LOOKS TO BE IN LINE FOR THE BEST
PRECIP CHANCES AND WILL CARRY A PERIOD OF MORE INTENSE SNOW DURING
THE LATE MORNING AS THE COLD AIR ARRIVES. ORD/MDW/DPA/GYY WILL SEE
A LATER TRANSITION TO ALL SNOW WITH COVERAGE AND INTENSITY IN
QUESTION. SURFACE AIR TEMPS WILL LIKELY REMAIN ABOVE FREEZING FOR
SEVERAL HOURS BEHIND THE FRONT SO SNOW MAY HAVE A TOUGH TIME
ACCUMULATING UNLESS IT FALLS AT A HIGH RATE...WHICH IS
POSSIBLE...ESPECIALLY AT RFD. OTHERWISE SLUSHY ACCUMULATION IS
POSSIBLE. A DRIER SNOW RATIO WILL DEVELOP INTO THE EVENING AS
TEMPS FALL FURTHER SO ACCUMULATION CHANCES WILL INCREASE AS WILL
THE LIKELIHOOD OF BLOWING SNOW. ANOTHER UPPER TROUGH IS FORECAST TO
MOVE ACROSS DURING THE LATE EVENING OR OVERNIGHT SO LIGHT SNOW
SHOULD OCCUR.
AGAIN...CONFIDENCE IN PRECIP DETAILS IS LOW FOR MONDAY SO BE SURE
TO MONITOR UPCOMING FORECASTS.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN IFR CONTINUING WITH SOME LOWERING OVERNIGHT.
* HIGH CONFIDENCE IN STEADIER RAIN DIMINISHING TO DRIZZLE
OVERNIGHT WITH STEADIER RAIN RETURNING AFTER DAYBREAK/MID
MORNING.
* MEDIUM-HIGH CONFIDENCE IN VSBY FALLING TO IFR OVERNIGHT. LOW
CONFIDENCE IN POTENTIAL TO GO BELOW 1SM.
* HIGH CONFIDENCE IN WIND TRENDS TONIGHT BUT MEDIUM CONFIDENCE IN
DIRECTION/SPEED DETAILS.
* HIGH CONFIDENCE IN WIND FORECAST MONDAY AND 30+ KT GUSTS. MEDIUM
CONFIDENCE IN SPORADICALLY REACHING 35 KT OR SO.
* HIGH CONFIDENCE IN RAIN CHANGING TO SNOW BUT LOW CONFIDENCE IN
HOW MUCH PRECIP COVERAGE THERE WILL BE THROUGH THE
AFTERNOON/EVENING.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...MVFR CIGS POSSIBLE WITH A FEW FLURRIES IN THE MORNING.
WEST WINDS.
WEDNESDAY...CHANCE OF SNOW. MVFR/IFR PSBL. SSE WINDS TURNING WEST.
THURSDAY...SCHC SNOW...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST WINDS.
MDB
&&
.MARINE...
237 PM...LOW PRESSURE OVER NORTHERN MINNESOTA WILL CONTINUE TO
WEAKEN AS IT REACHES WESTERN LAKE SUPERIOR THIS EVENING. LOW
PRESSURE OVER OKLAHOMA WILL MOVE NORTHEAST ACROSS THE LAKE TONIGHT
ABSORBING THE WEAKENING LOW OVER LAKE SUPERIOR. THE TRACK OF THIS
LOW HAS CONTINUED TO DRIFT A LITTLE FURTHER EAST WITH EACH RUN AND
THE LOW NOW PASSES EAST OF LAKE SUPERIOR...MOVING OVER EASTERN
ONTARIO MONDAY WITH A PRESSURE NEAR 28.8 INCHES. THIS WILL DELAY
THE ONSET OF GALES BY A FEW HOURS...UNTIL LATE MORNING ACROSS THE
SOUTHERN PART OF THE LAKE AND THEN TO LATE AFTERNOON ACROSS THE
NORTHERN PART. UPGRADED THE GALE WATCH TO A GALE WARNING FOR THE
SOUTH HALF BUT MAINTAINED THE WATCH ACROSS THE NORTHERN HALF.
GALES WILL DIMINISH BY DAYBREAK TUESDAY WITH WINDS STEADILY
DIMINISHING TUESDAY AS HIGH PRESSURE MOVES ACROSS THE SOUTHERN
LAKES AND OHIO VALLEY. ANOTHER LOW WILL MOVE ACROSS THE LAKES
REGION WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-
ILZ011...NOON MONDAY TO MIDNIGHT TUESDAY.
WINTER WEATHER ADVISORY...ILZ005-ILZ006-ILZ012...3 PM MONDAY TO
MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 AM MONDAY TO 3 AM TUESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 PM MONDAY TO 3 AM TUESDAY.
&&
$$
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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WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
911 PM CST Sun Nov 23 2014
.UPDATE...
ISSUED AT 910 PM CST SUN NOV 23 2014
Double low pressure centers have developed this evening, with one
circulation just northeast of Lawrenceville and another just west
of Galesburg. The trough connecting the two lows generally marks
the line of the back edge of steady rains and the onset of drizzle
and fog. Additional rains are approaching from across Missouri and
Iowa associated with increasing jet dynamics and a potential
vorticity anomaly. The return of steadier rains after midnight
from west to east will diminish fog and drizzle conditions as
winds steadily increase from the WSW. Colder air will approach
Illinois late tonight, but there will not be a deep enough layer
of cold air at the surface to change any rain to snow before
12z/6am in our counties. However, the blast of cold air will
quickly advance across IL Monday morning, with west winds
increasing to near wind advisory levels /30 mph sustained winds or
gusts to 45 mph/. Most areas should remain below those numbers, so
no wind advisory has been issued in our forecast area to this
point.
As the cold air changes any rain to snow, snow accums still look
possible generally north of a line from Rushville to Lincoln to
Bloomington, especially north of Peoria where up to an inch of
snow could accumulate. The snow will be blowing sideways as it
falls due to the strong winds, which will make it very difficult
to measure, and any accumulations on the ground will be blown
around as well. Visibility could drop to low levels during the
snows from mid morning to early afternoon, before snowfall rates
diminish during the afternoon.
Updates this evening have focused on weather grids through
tomorrow afternoon, and updated info is already available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 313 PM CST SUN NOV 23 2014
Deepening 993 mb low pressure between Oklahoma City and Tulsa at mid
afternoon will strengthen further as it ejects northeast across
central IL near or east of I-55 during this evening, and into
northern lower MI overnight at it deepens to 979 mb. Widespread
light to moderate rain showers have spread NNE across central/se IL
early this afternoon. Still no reports of thunder over IL but will
continue to carry isolated thunderstorms over eastern IL into this
evening as deepening low pressure approaches.
Showers will break up later this evening and overnight east of the
IL river while deformation zone of precipitation lingers west of the
IL river. Strong cold front sweeps across central and eastern IL
during overnight, passing through the Wabash river valley early
Monday morning. Light rain to mix with light snow nw of the IL river
late tonight and change to snow early Monday morning as temps fall
into the mid 30s. Temperatures currently in the low to mid 50s and
dewpoints are in the upper 40s and lower 50s. Lows tonight to range
from mid 30s from Peoria and Springfield west, to the mid to upper
40s near the IN/IL border with temps continue to drop Monday
morning. Southeast winds 10-17 mph and gusts of 18-25 mph this
afternoon to subside this evening to around 10 mph or less as low
pressure moves in. But as low deepens and pulls away from central/se
IL overnight, winds will turn westerly behind the cold front and
increase to 15-25 mph and gust 25 to 30 mph later tonight. RUC model
shows even higher wind gusts of 35-40 mph going into southeast IL
behind cold front early Monday morning around sunrise. MET/MAV
guidance shows strongest winds during the day Monday (strongest in
eastern IL) after 15Z/9 am Monday.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 313 PM CST SUN NOV 23 2014
The strong low pressure area will continue to lift northeast through
the Great Lakes area with a very strong pressure gradient behind the
system. In addition, gusty westerly winds and strong cold air
advection (CAA) will move into the area Monday. Expecting rain in
the eastern half of the CWA and a mix of rain and snow in the
western half,in the morning. Then as the CAA occurs, the all snow
line will move across the area from west to east, so that by early
afternoon, most of the CWA will be all snow, with the mix of rain
and snow only in the eastern parts of the CWA. By late afternoon,
the whole area will be cold enough for snow. As the system lifts
northeast through the day, the higher chances of pcpn will move from
southwest to northeast. So, the areas mostly likely to see any
accumulation of snow will be Northwest of I-55 during the morning and
then north of a Galesburg to Bloomington line during the afternoon.
Total snowfall accumulation expected tomorrow will be an inch or
more northwest of a Macomb to Pontiac line; and then lesser amounts
southeast of that line. Highest amounts are expected to be 1.5 to 2
inches north of a Galesburg to Lacon line.
The tight gradient behind this system will also bring very gusty
winds to the CWA tomorrow, beginning tomorrow morning and lasting
through the day. Sustained winds or around 25 mph with gusts between
35 and 40 mph will be possible across the whole area tomorrow. Will
not be issuing a wind advisory as it will be just below criteria.
However, would not be surprised if overnight shift issues one in the
morning. The gusty winds will also create blowing snow, mainly in
the northern parts of the CWA, so visibilities could be reduced at
times.
Pcpn will end by tomorrow night as the low pressure area lifts
northeast into Canada. After this system, dry weather is expected
for Monday night through Tue night as brief high pressure area moves
through the CWA. Then another clipper system is expected to move
through the area and bring another chance of rain and/or snow for
Wednesday. There will be some warm air ahead of this system so the
pcpn type could be a mix before it changes to all snow. Any
accumulations with this system will be confined to the north with a
half inch or less possible...at this time. The remainder of the
forecast should be dry with temps below normal, as Canadian high
pressure moves in and dominates the weather through the rest of the
week and into the weekend.
Temps will steady or slowly falling tomorrow due to the strong CAA
expected. Then temps will be cool/cold most of the rest of the
forecast, except for Wed, just ahead of the next clipper system.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 600 PM CST SUN NOV 23 2014
IFR and LIFR ceilings of 300-700 ft have developed over central IL
airports this afternoon and expect ceilings to remain there tonight.
MVFR visibilities due to rainfall should continue during the steady
moderate rains this evening. Radar trends show the precipitation
will diminish from west to east between 02z to 06z, but visibility
will likely remain low due to the onset of drizzle and fog. No
thunderstorms are expected at any TAF site this evening.
Cold air will filter into central IL late tonight and Monday
morning, causing the rain showers to mix with or change to light
snow from west to east. As the precipitation becomes all snow, vsbys
could drop as low as 1-2 miles at PIA and BMI where snowfall
accumulation could climb up as high as 1 inch. Vsbys should remain 2-4
miles farther south along I-72 where snowfall will be lighter. SE
winds have diminished to 7-10 kts already. Winds will veer SW overnight
and become W later tonight into Monday morning, with speeds
increasing to 20-25 kts and gusts 26-34 kts by 18z/Noon on Monday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...07
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
622 PM CST SUN NOV 23 2014
.SHORT TERM...
244 PM CST
UNSEASONABLY WARM/MOIST AIRMASS CONTINUES TO ADVECT NORTH ACROSS THE
REGION THIS AFTN...AND LOOKS TO CONTINUE THROUGH TONIGHT. THE MAIN
CONCERN FOR THE OVERNIGHT WILL BE ON RAINFALL TOTALS AND IF THIS
WILL POSE ANY HYDRO CONCERNS.
STRONG WARM AIR ADVECTION THIS AFTERNOON HAS ALLOWED SFC TEMPS TO
WARM INTO THE 50S ACROSS MUCH OF THE FORECAST AREA WITH DEW POINTS
APPROACHING THE UPPER 40S/ARND 50. THE AXIS OF THE HEAVIER RAINFALL
THIS AFTN HAS SHIFTED TO THE NORTHWEST AND STRETCHES FROM CENTRAL
WISC SOUTHWEST THROUGH FAR EASTERN IOWA. HAVE NUDGED TEMPS OVERNIGHT
UP A TAD...AND EXPECT TEMPS TO REMAIN NEARLY CONSISTENT UNTIL CLOSER
TO DAYBREAK MON WHEN THE FRONTAL BOUNDARY BEGINS TO APPROACH THE
NORTHWEST CWFA. GUIDANCE CONTINUES TO SUGGEST THE LOW DROPPING
SOUTHEAST ACROSS THE UPPER MIDWEST AND THE SECONDARY ONE LIFTING
NORTH FROM THE SOUTHWEST...WILL CONVERGE ACROSS SOUTHWEST LOWER
MICHIGAN JUST BEFORE DAYBREAK MON. THE COLD FRONT WILL BE NEARING
THE WESTERN CWFA ARND DAYBREAK...AND STEADILY SLIDE EAST THRU THE
MORNING. ASSOCIATED WILL BE A SHARP THERMAL TROUGH THAT WILL CAUSE
TEMPS TO STEADILY FALL THROUGHOUT THE MORNING/AFTN. SO THE DAY MAY
START MILD...BUT BY MIDDAY THAT WILL CERTAINLY NOT BE THE CASE WITH
TEMPS GENERALLY IN THE UPR 20S/LOW 30S. PRECIP WILL BE QUICKLY
TRANSITIONING OVER FROM RAIN TO SNOW.
AS THE SNOW BEGINS MIDDAY ACROSS THE NORTHWEST...GUIDANCE HAS BEEN
RELATIVELY CONSISTENT THAT AT ONSET RATIOS WILL HOVER ARND 8:1 TO
9:1...THEN AS THE COLDER AIR ADVECTS IN THOSE RATIOS SHUD STEADILY
CLIMB TO 14:1-17:1 BY LATE MON AFTN/EARLY EVE. COMPOUNDING THE SETUP
WILL BE STEADILY INCREASING PRESSURE GRADIENT THAT WILL CREATE GUSTY
WINDS NEARING 30-35MPH. THERE IS A NARROW WINDOW WHERE SNOWFALL
RATES COULD NEAR 1-2"/HR FOR A COUPLE HOURS...MAINLY BETWEEN 2-4PM
CST AND MAINLY WEST OF A LASALLE TO CRYSTAL LAKE LINE. HAVE BUMPED
SNOW TOTALS UP TO 2-4" AND COULD SEE IN PORTIONS OF WINNEBAGO COUNTY
3-5" CLOSER TO THE WISC STATELINE IN NORTHERN WINNEBAGO COUNTY.
ELSEWHERE SNOW WILL BEGIN TO ACCUMULATE...BUT EXPECTING MUCH LESS
WITH PERHAPS AN INCH IN CHICAGO AND LESSER TOTALS FURTHER SOUTH.
500MB TROUGH AXIS PIVOTS OVERHEAD MON EVE...AND WILL SLOWLY BRING AN
END TO THE ACCUMULATING SNOW. THE BETTER MOISTURE WILL QUICKLY PEEL
OFF TO THE NORTHEAST LATE MON NGT...HOWEVER ENOUGH OMEGA/MOISTURE TO
KEEP MENTION OF LGT SNOW SHOWERS MON NGT.
OVERNIGHT LOWS MON DIP FALL TO THE LOW 20S TO MID 20S IN THE
SOUTHEAST.
BEACHLER
&&
.LONG TERM...
244 PM CST
TUESDAY THROUGH WEDNESDAY...
LARGE MID-LVL TROUGH WILL BE IN PLACE TUE/WED WITH A WEAK SFC RIDGE
LIFTING NORTH AND BRINGING A GRADUAL EROSION TO THE CLOUDS TUE
NGT/WED. UNFORTUNATELY THIS MAY BE SHORT LIVED AS GUIDANCE SUGGESTS
A QUICK SHORTWAVE WILL DROP SOUTH FROM CENTRAL CANADA INTO THE
NORTHERN PLAINS EARLY WED...AND APPROACH THE FORECAST AREA MIDDAY
WED. THIS SYSTEM COULD BRING ANOTHER PERIOD OF LIGHT SNOW WITH SOME
MINOR ACCUMULATIONS.
TEMPS TUE WILL REMAIN IN THE 20S...HOWEVER WITH SOME THINNING IN THE
CLOUDS FOR WED TEMPS COULD REBOUND INTO THE LOW/MID 30S. BUT IT WILL
HINGE UPON THE ARRIVAL OF THE NEXT MID-LVL WAVE AND CLOUD COVER.
THURSDAY THROUGH SATURDAY...
ENSEMBLES IN THE LONGER TERM CONTINUES TO POINT TOWARDS A TROUGH
CARVED OUT ACROSS THE GREAT LAKES/TENN VALLEY FOR THE SECOND HALF OF
THE WEEK...AND THEN BEGINS TO FLATTEN FOR THE SECOND HALF OF THE
WEEKEND. AT THIS TIME GUIDANCE SUGGESTS DRY AIR AND A SFC RIDGE
OVERHEAD FOR THANKSGIVING DAY. TEMPS WILL GENERALLY BE IN THE 20S
FOR THE BULK OF THE EXTENDED.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SLOWLY LOWERING IFR CIGS WITH RAIN THROUGH THE
EVENING...VARIABLE 2-5SM VSBY. LESS INTENSE RAIN/DRIZZLE
OVERNIGHT WITH BETTER CHANCE FOR IFR VSBY.
* SOUTHEAST WINDS TURNING SOUTHWEST OR EVEN LIGHT/VARIABLE LATE
THIS EVENING.
* WINDS SHIFT WEST MONDAY MORNING THEN SOUTHWEST WITH GUSTS TO 30
KT WITH A PERIOD OF 35 KT GUSTS POSSIBLE MIDDAY/EARLY AFTERNOON.
* RAIN CHANGES TO SNOW MIDDAY...SOME LIGHT ACCUMULATION
POSSIBLE...ESPECIALLY LATER IN THE DAY.
MDB
//DISCUSSION...UPDATED 00Z...
HAVE GOOD CONFIDENCE IN THE FORECAST THROUGH TONIGHT BUT LOWER
CONFIDENCE MONDAY...ESPECIALLY IN TERMS OF RAIN/SNOW TRENDS. LOW
PRESSURE TAKING SHAPE OVER SW MISSOURI THIS EVENING WILL QUICKLY
TRACK NORTHEAST ACROSS THE AREA EARLY TONIGHT. SOUTHEAST WINDS
WILL TURN SOUTHWEST AND PROBABLY DIMINISH IN SPEED AS THE LOW
PASSES SO LIGHT/VARIABLE CONDITIONS MAY OCCUR FOR A TIME
OVERNIGHT. RAIN CONTINUES TO STREAM NORTHWARD ACROSS THE TERMINALS
WITH RFD NEAR THE WESTERN EDGE. DRIER MID LEVEL AIR WILL WRAP IN
INTO THE OVERNIGHT SO A TRANSITION TO LIGHTER RAIN OR JUST DRIZZLE
IS EXPECTED. THIS WILL BE UNDERWAY AT RFD THIS EVENING. IFR CIGS
WILL LOWER SOMEWHAT WITH TIME WHILE VSBY IN THE RAIN VARIES
BETWEEN 2 AND 6SM. DRIZZLE TONIGHT WILL LIKELY ALLOW VSBY TO FALL
TO IFR AND MAY NEED TO CARRY SUB 1SM VSBY FOR A PERIOD.
A SHARP COLD FRONT WORKS ACROSS THE TERMINALS AFTER DAYBREAK
SHIFTING WINDS TO WEST AND ALLOWING THEM TO RAMP UP. GUSTS WILL
PUSH 30 KT BY MID/LATE MORNING WITH 35 KT OR SO POSSIBLE AT TIMES
INTO EARLY AFTERNOON. THE DIRECTION WILL LIKELY BECOME A LITTLE
MORE SOUTHWESTERLY INTO THE AFTERNOON AS WELL. ANOTHER PERIOD OF
PRECIP LOOKS LIKELY DURING THE MORNING INTO MIDDAY WHICH WILL
TRANSITION TO SNOW AS COLDER AIR ARRIVES. LATEST FORECAST GUIDANCE
IS SUGGESTING THAT HIGHER LEVEL MOISTURE WANES DURING THE
AFTERNOON LEADING TO LIGHTER PRECIP OR EVEN MORE DRIZZLE. GUIDANCE
HAS NOT BEEN TERRIBLY CONSISTENT ON DETAILS SO CONFIDENCE IS ON
THE LOW SIDE. EITHER WAY RFD LOOKS TO BE IN LINE FOR THE BEST
PRECIP CHANCES AND WILL CARRY A PERIOD OF MORE INTENSE SNOW DURING
THE LATE MORNING AS THE COLD AIR ARRIVES. ORD/MDW/DPA/GYY WILL SEE
A LATER TRANSITION TO ALL SNOW WITH COVERAGE AND INTENSITY IN
QUESTION. SURFACE AIR TEMPS WILL LIKELY REMAIN ABOVE FREEZING FOR
SEVERAL HOURS BEHIND THE FRONT SO SNOW MAY HAVE A TOUGH TIME
ACCUMULATING UNLESS IT FALLS AT A HIGH RATE...WHICH IS
POSSIBLE...ESPECIALLY AT RFD. OTHERWISE SLUSHY ACCUMULATION IS
POSSIBLE. A DRIER SNOW RATIO WILL DEVELOP INTO THE EVENING AS
TEMPS FALL FURTHER SO ACCUMULATION CHANCES WILL INCREASE AS WILL
THE LIKELIHOOD OF BLOWING SNOW. ANOTHER UPPER TROUGH IS FORECAST TO
MOVE ACROSS DURING THE LATE EVENING OR OVERNIGHT SO LIGHT SNOW
SHOULD OCCUR.
AGAIN...CONFIDENCE IN PRECIP DETAILS IS LOW FOR MONDAY SO BE SURE
TO MONITOR UPCOMING FORECASTS.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN IFR CIGS LOWERING SLIGHTLY THIS EVENING. HIGH
CONFIDENCE RAIN/DRIZZLE TRENDS THROUGH THE NIGHT. MEDIUM
CONFIDENCE IN IFR VSBY OVERNIGHT.
* HIGH CONFIDENCE IN WIND TRENDS TONIGHT BUT MEDIUM CONFIDENCE IN
DIRECTION/SPEED DETAILS.
* HIGH CONFIDENCE IN WIND FORECAST MONDAY AND 30+ KT GUSTS. MEDIUM
CONFIDENCE IN SPORADICALLY REACHING 35 KT OR SO.
* HIGH CONFIDENCE IN RAIN CHANGING TO SNOW BUT LOW CONFIDENCE IN
HOW MUCH PRECIP COVERAGE THERE WILL BE THROUGH THE
AFTERNOON/EVENING.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...MVFR CIGS POSSIBLE WITH A FEW FLURRIES IN THE MORNING.
WEST WINDS.
WEDNESDAY...CHANCE OF SNOW. MVFR/IFR PSBL. SSE WINDS TURNING WEST.
THURSDAY...SCHC SNOW...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST WINDS.
MDB
&&
.MARINE...
237 PM...LOW PRESSURE OVER NORTHERN MINNESOTA WILL CONTINUE TO
WEAKEN AS IT REACHES WESTERN LAKE SUPERIOR THIS EVENING. LOW
PRESSURE OVER OKLAHOMA WILL MOVE NORTHEAST ACROSS THE LAKE TONIGHT
ABSORBING THE WEAKENING LOW OVER LAKE SUPERIOR. THE TRACK OF THIS
LOW HAS CONTINUED TO DRIFT A LITTLE FURTHER EAST WITH EACH RUN AND
THE LOW NOW PASSES EAST OF LAKE SUPERIOR...MOVING OVER EASTERN
ONTARIO MONDAY WITH A PRESSURE NEAR 28.8 INCHES. THIS WILL DELAY
THE ONSET OF GALES BY A FEW HOURS...UNTIL LATE MORNING ACROSS THE
SOUTHERN PART OF THE LAKE AND THEN TO LATE AFTERNOON ACROSS THE
NORTHERN PART. UPGRADED THE GALE WATCH TO A GALE WARNING FOR THE
SOUTH HALF BUT MAINTAINED THE WATCH ACROSS THE NORTHERN HALF.
GALES WILL DIMINISH BY DAYBREAK TUESDAY WITH WINDS STEADILY
DIMINISHING TUESDAY AS HIGH PRESSURE MOVES ACROSS THE SOUTHERN
LAKES AND OHIO VALLEY. ANOTHER LOW WILL MOVE ACROSS THE LAKES
REGION WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-
ILZ011...NOON MONDAY TO MIDNIGHT TUESDAY.
WINTER WEATHER ADVISORY...ILZ005-ILZ006-ILZ012...3 PM MONDAY TO
MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 AM MONDAY TO 3 AM TUESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 PM MONDAY TO 3 AM TUESDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
606 PM CST Sun Nov 23 2014
.SHORT TERM...(Tonight)
ISSUED AT 313 PM CST SUN NOV 23 2014
Deepening 993 mb low pressure between Oklahoma City and Tulsa at mid
afternoon will strengthen further as it ejects northeast across
central IL near or east of I-55 during this evening, and into
northern lower MI overnight at it deepens to 979 mb. Widespread
light to moderate rain showers have spread NNE across central/se IL
early this afternoon. Still no reports of thunder over IL but will
continue to carry isolated thunderstorms over eastern IL into this
evening as deepening low pressure approaches.
Showers will break up later this evening and overnight east of the
IL river while deformation zone of precipitation lingers west of the
IL river. Strong cold front sweeps across central and eastern IL
during overnight, passing through the Wabash river valley early
Monday morning. Light rain to mix with light snow nw of the IL river
late tonight and change to snow early Monday morning as temps fall
into the mid 30s. Temperatures currently in the low to mid 50s and
dewpoints are in the upper 40s and lower 50s. Lows tonight to range
from mid 30s from Peoria and Springfield west, to the mid to upper
40s near the IN/IL border with temps continue to drop Monday
morning. Southeast winds 10-17 mph and gusts of 18-25 mph this
afternoon to subside this evening to around 10 mph or less as low
pressure moves in. But as low deepens and pulls away from central/se
IL overnight, winds will turn westerly behind the cold front and
increase to 15-25 mph and gust 25 to 30 mph later tonight. RUC model
shows even higher wind gusts of 35-40 mph going into southeast IL
behind cold front early Monday morning around sunrise. MET/MAV
guidance shows strongest winds during the day Monday (strongest in
eastern IL) after 15Z/9 am Monday.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 313 PM CST SUN NOV 23 2014
The strong low pressure area will continue to lift northeast through
the Great Lakes area with a very strong pressure gradient behind the
system. In addition, gusty westerly winds and strong cold air
advection (CAA) will move into the area Monday. Expecting rain in
the eastern half of the CWA and a mix of rain and snow in the
western half,in the morning. Then as the CAA occurs, the all snow
line will move across the area from west to east, so that by early
afternoon, most of the CWA will be all snow, with the mix of rain
and snow only in the eastern parts of the CWA. By late afternoon,
the whole area will be cold enough for snow. As the system lifts
northeast through the day, the higher chances of pcpn will move from
southwest to northeast. So, the areas mostly likely to see any
accumulation of snow will be Northwest of I-55 during the morning and
then north of a Galesburg to Bloomington line during the afternoon.
Total snowfall accumulation expected tomorrow will be an inch or
more northwest of a Macomb to Pontiac line; and then lesser amounts
southeast of that line. Highest amounts are expected to be 1.5 to 2
inches north of a Galesburg to Lacon line.
The tight gradient behind this system will also bring very gusty
winds to the CWA tomorrow, beginning tomorrow morning and lasting
through the day. Sustained winds or around 25 mph with gusts between
35 and 40 mph will be possible across the whole area tomorrow. Will
not be issuing a wind advisory as it will be just below criteria.
However, would not be surprised if overnight shift issues one in the
morning. The gusty winds will also create blowing snow, mainly in
the northern parts of the CWA, so visibilities could be reduced at
times.
Pcpn will end by tomorrow night as the low pressure area lifts
northeast into Canada. After this system, dry weather is expected
for Monday night through Tue night as brief high pressure area moves
through the CWA. Then another clipper system is expected to move
through the area and bring another chance of rain and/or snow for
Wednesday. There will be some warm air ahead of this system so the
pcpn type could be a mix before it changes to all snow. Any
accumulations with this system will be confined to the north with a
half inch or less possible...at this time. The remainder of the
forecast should be dry with temps below normal, as Canadian high
pressure moves in and dominates the weather through the rest of the
week and into the weekend.
Temps will steady or slowly falling tomorrow due to the strong CAA
expected. Then temps will be cool/cold most of the rest of the
forecast, except for Wed, just ahead of the next clipper system.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 600 PM CST SUN NOV 23 2014
IFR and LIFR ceilings of 300-700 ft have developed over central IL
airports this afternoon and expect ceilings to remain there tonight.
MVFR visibilities due to rainfall should continue during the steady
moderate rains this evening. Radar trends show the precipitation
will diminish from west to east between 02z to 06z, but visibility
will likely remain low due to the onset of drizzle and fog. No
thunderstorms are expected at any TAF site this evening.
Cold air will filter into central IL late tonight and Monday
morning, causing the rain showers to mix with or change to light
snow from west to east. As the precipitation becomes all snow, vsbys
could drop as low as 1-2 miles at PIA and BMI where snowfall
accumulation could climb up as high as 1 inch. Vsbys should remain 2-4
miles farther south along I-72 where snowfall will be lighter. SE
winds have diminished to 7-10 kts already. Winds will veer SW overnight
and become W later tonight into Monday morning, with speeds
increasing to 20-25 kts and gusts 26-34 kts by 18z/Noon on Monday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
302 PM CST SAT NOV 22 2014
.SHORT TERM...THIS AFTERNOON AND TONIGHT...
258 PM CST
FOR THE REMAINDER OF THIS AFTERNOON AND THROUGH TONIGHT...AN
INFLUX OF WARM...MOIST AIR WILL CONTINUE TO STREAM INTO THE UPPER
MIDWEST. LATEST SFC ANALYSIS SHOWS DEWPOINTS IN THE 50S OVER
MISSOURI WHILE DEWPOINTS ACROSS NRN IL. NWRN IN HAVE CLIMBED INTO
THE MIDDLE TO UPPER 40S. TEMPERATURES HAVE ALSO BEEN ON THE RISE
THROUGH THE DAY WITH TEMPERATURES AT OR IN EXCESS OF 50F AS FAR
NORTH AS MIDWAY AIRPORT AND AURORA AS OF 230PM CST. TEMPERATURES
ARE EXPECTED TO CONTINUE TO RISE INTO THE EARLY EVENING UNDER THE
PERSISTENT WARM...MOIST ADVECTION UNDER A STRONG SWLY LOW LEVEL
JET WITH 850MB WINDS UP TO 45KT...TEMPERATURES WILL LIKELY HOVER
AROUND THE 50 DEGREE MARK THROUGH THE NIGHT. ADDITIONAL LIGHT RAIN
OR DRIZZLE WILL PERSIST THROUGH THE EVENING AND OVERNIGHT...WITH
AREAS OF FOG POSSIBLE.
KREIN
&&
.LONG TERM...SUNDAY THROUGH FRIDAY...
258 PM CST
MORE SIGNIFICANT RAINFALL IS SETTING UP FOR SUNDAY AND INTO
SUNDAY NIGHT AS A STRONG SRN STREAM SHORTWAVE LIFTING OUT OF THE
SOUTH HIGH PLAINS PHASES WITH ANOTHER SHORTWAVE LIFTING FROM THE
SOUTHWEST GULF COAST REGION. THESE SYSTEM WILL RESULT IN A
DEEPENING SFC LOW OF 984MB NEAR ST LOUIS BY SUNDAY EVENING. THE
MODELS CONTINUE TO ADVERTISE PWAT VALUES AROUND 1.2 INCHES...WHICH
IS AT THE 99TH PERCENTILE FOR PWATS FOR THE REGION. THIS PHASING
OF THE TWO SRN STREAM SYSTEMS COMBINED WITH THE UNUSUALLY HIGH
PWAT AIRMASS WILL COMBINE TO FOCUS STEADY RAINFALL ACROSS THE
REGION THROUGH THE DAY ON SUNDAY AND INTO SUNDAY EVENING...WITH A
CORRIDOR OF THE HEAVIEST RAIN OVER THE NWRN PORTIONS OF THE
CWA...GENERALLY NORTH OF A LINE FROM PERU TO MCHENRY...WHERE
UPWARDS OF A HALF INCH PER 3 HOUR PERIOD IS POSSIBLE. LATER SUNDAY
NIGHT...THE PHASED SRN STREAM SYSTEM WILL BEGIN TO PHASE WITH A
NRN STREAM SHORTWAVE...WITH LOW PRESSURE RAPIDLY DEEPENING AS IT
LIFTS THROUGH THE UPPER GREAT LAKES. WHILE THE GUIDANCE IS
RELATIVELY CONSISTENT ON THE TRACK AND TIMING OF THE DEEPENING
LOW...THE GFS IS A MUCH STRONGER OUTLIER IN THE GUIDANCE
ENVELOPE...DEEPENING THE CENTRAL PRESSURE TO ARND 966MB BY MIDDAY
MONDAY...WHILE MUCH OF THE OTHER GUIDANCE ONLY DEEPENS THE LOW TO
ARND 980MB. WHILE THE GFS SOLUTION MAY BE TOO DEEP...LIKELY
DRAWING COLDER AIR INTO THE SYSTEM FASTER THAN THE OTHER
MODELS...OR TAPPING MORE NRN STREAM ENERGY...THERE WILL STILL
LIKELY BE A DEEP LOW DEVELOPING OVER THE UPPER GREAT LAKES SUNDAY
NIGHT INTO MONDAY...WHOSE CIRCULATION PATTERN WILL COVER A LARGE
EXPANSE FROM THE EAST-CENTRAL PLAINS TO NERN QUEBEC. A STRONG WLY-
NWLY GRADIENT WILL SET UP ON THE SWRN PERIPHERY OF THE
SYSTEM...LEADING TO STRONG...GUSTY WINDS ACROSS THE CWA FROM EARLY
MONDAY MORNING THROUGH LATE MONDAY EVENING. THE STRONGEST WINDS
SHOULD OCCUR FROM LATE MORNING THROUGH LATE EVENING...WITH
SUSTAINED WINDS OF 25-30 MPH AND PEAK GUSTS OF 35-40 MPH.
HOWEVER...IF THE SYSTEM EVOLVES A LITTLE DEEPER THAT THE CONSENSUS
GUIDANCE AND DEEPENS CLOSER TO THE OUTLIER GFS SOLUTION...WINDS
ACROSS THE AREA COULD REACH WIND ADVISORY LEVELS OF SUSTAINED
WINDS OF 30 MPH OR HIGHER OR GUSTS OF 45 MPH OR GREATER.
ALSO...AS THE SFC LOW BEGINS TO LIFT OUT TO THE NORTHEAST MONDAY
AFTERNOON...MUCH COOLER AIR WILL BEGIN TO FILTER ACROSS THE REGION.
AS THE PATTERN TRANSITIONS FROM ONE OF STRONG WARM ADVECTION SUNDAY
NIGHT TO STRONG COLD ADVECTION BY MONDAY MORNING...FOLLOWING THE
PASSAGE OF A STRONG ASSOCIATED COLD FRONT...LINGERING PCPN WILL
BEGIN TO TRANSITION FROM RAIN TO SNOW. SINCE THE COLD AIR SHOULD
EXTEND THROUGH THE ENTIRE ATMOSPHERE...THERE SHOULD BE A MORE
STRAIGHTFORWARD TRANSITION FROM RAIN TO SNOW WITH LITTLE CHANCE FOR
ANY FREEZING RAIN OR SLEET. THERE COLD BE SOME ISSUES WITH WATER
FLASH FREEZING ON ELEVATED SURFACES AS SUB-FREEZING AIR QUICKLY
FILTERS ACROSS THE REGION BY LATE MONDAY AFTERNOON.
THE STRONG COLD ADVECTION WILL PERSIST THROUGH THE NIGHT WITH
TEMPERATURES DROPPING TO THE LOWER TO MIDDLE 20S BY DAYBREAK TUESDAY
MORNING. THE PERSISTENT COLD ADVECTION WILL ALLOW FOR LITTLE
DIURNAL WARMING WITH HIGHS ON TUESDAY EXPECTED TO BE IN THE UPPER
20S TO ARND 30F OVER THE FAR SERN PORTIONS OF THE CWA. THERE BE SOME
MODERATION TO TEMPERATURES ON WEDNESDAY AS WEAK SFC RIDGING CROSSES
THE AREA ALLOWING TEMPERATURES TO RISE INTO THE MIDDLE 30S.
WEDNESDAY SHOULD BE THE WARMEST OF THE EXTENDED PERIOD. A SERIES OF
STRONG NORTHERN STREAM SHORTWAVES IS EXPECTED TO CARVE OUT A BROAD
LONGWAVE TROUGH OVER ERN CONUS FROM THE MISSISSIPPI VALLEY TO THE
EAST COAST. THE UPPER LEVEL PATTERN SHOULD DECREASE IN AMPLITUDE
THROUGH THE EXTENDED PERIOD...BUT THE LOCAL AREA IS EXPECTED TO
REMAIN UNDER GENERAL NWLY FLOW ALOFT...KEEPING A PERSISTENT FETCH OF
COLD AIR ACROSS THE AREA. BY LATE NEXT WEEK...HIGH TEMPERATURES WILL
STRUGGLE INTO THE LOWER TO MIDDLE 20S...WHILE OVERNIGHT LOWS DROP
INTO THE LOWER TO MIDDLE TEENS...WITH THE POSSIBILITY OF THE NWRN
PORTIONS OF THE CWA...INCLUDING THE ROCKFORD AREA DROPPING INTO THE
SINGLE DIGITS FRIDAY AND SATURDAY MORNING. THE SERIES OF SHORTWAVES
RIPPLING THROUGH THE NORTHWEST FLOW SHOULD BRING PERIODIC CHANCES
FOR SOME LIGHT SNOW...BUT CONFIDENCE IS LOW ON THE EXACT TIMING.
CONFIDENCE IS A LITTLE HIGHER THAT ANY SNOW THAT DOES OCCUR SHOULD
BE LIGHT AS THERE WILL BE LITTLE ENVIRONMENTAL MOISTURE OR SFC
FORCING. ANY SNOW GENERATION WILL HAVE TO RELY ON MID-LEVEL FORCING
AND MEAGER MOISTURE CONTENT.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* PATCHY IFR CIGS...TO LOW END MVFR CIGS THIS AFTN. LIKELY
TRENDING BACK TOWARDS IFR OVERNIGHT THRU SUN MORNING.
* VSBY WILL HOVER BETWEEN 3-6SM THIS AFTN...POSSIBLY FALLING TO
JUST UNDER 3SM OVERNIGHT THRU SUN MORNING.
* LOW-LEVEL WIND SHEAR DEVELOPING TONIGHT. ARND 2KFT AGL FROM THE
SOUTHWEST NEARING 45KT.
* RAIN SHOWERS DEVELOPING EARLY SUN MORNING...INCREASING IN
COVERAGE CLOSER TO MIDDAY.
BEACHLER
//DISCUSSION...UPDATED 18Z...
VERY MOIST AIR MASS CONTINUES TO FEED NORTHEAST ACROSS NORTHERN
IL/NORTHWEST IN AIRFIELDS THIS AFTERNOON. LITTLE IMPROVEMENT TO
THE CIGS IS EXPECTED...AS A RESULT HAVE HELD CIGS DOWN ARND LOW
END MVFR THIS AFTN AND WILL LIKELY TREND BACK TOWARDS IFR CONDS
OVERNIGHT. GENERALLY EXPECT CIGS ARND 500-900FT AGL THRU THE
OVERNIGHT HOURS. WIND DIR WILL NOT CHANGE MUCH THIS
AFTN/EVE/OVERNIGHT...MAINLY FROM THE SOUTH WITH SPEEDS ALSO NOT
CHANGING MUCH ARND 10-12KT. GIVEN HOW MOIST THE ATMOSPHERE
IS...PERIODIC ROUNDS OF DRIZZLE CAN BE EXPECTED THRU THIS
AFTN/EARLY EVE WILL A LULL LATE THIS EVE. WIND SHEAR IS ALSO
POISED TO DEVELOP THIS EVENING...WITH WINDS ARND 2KFT AGL FROM THE
SOUTHWEST INCREASING TO 40-45KT.
GUIDANCE HAS CONTINUED TO SUGGEST DEVELOPING RAIN SHOWERS AFT
MIDNIGHT/EARLY SUN...SO HAVE HELD ONTO THE MENTION OF LGT RAIN
EARLY SUN. THEN IT APPEARS THE BETER COVERAGE FOR PERHAPS MORE
STEADY RAIN WILL OCCUR LATE SUN MORNING...AND COULD PERSIST THRU
SUN AFTN.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN CIGS HOLDING AT LOW END MVFR...AND MEDIUM
CONFIDENCE ON TIMING CIGS TRENDING BACK TOWARDS IFR.
* HIGH CONFIDENCE IN WIND DIR/SPEED.
* MEDIUM CONFIDENCE IN LOW-LEVEL WIND SHEAR.
* HIGH CONFIDENCE IN DRIZZLE THRU THIS AFTN...THEN MEDIUM
CONFIDENCE IN TIMING OF ENDING THE MENTION OF DRIZZLE.
* HIGH CONFIDENCE IN LIGHT RAIN DEVELOPING EARLY SUN WITH BETTER
COVERAGE LATE SUN MORNING/AFTN. MEDIUM CONFIDENCE IN PRECISE
TIMING OF RAIN IMPACTING TAF SITES.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...RAIN AND IFR PROBABLE. SOUTHERLY WINDS.
MONDAY...CHANCE OF RAIN AND SNOW. STRONG WEST TO SOUTHWEST WINDS.
TUESDAY...MVFR CIGS POSSIBLE. WESTERLY WINDS.
WEDNESDAY...CHANCE OF SNOW AND MVFR. SOUTHWEST WINDS.
THURSDAY...FLURRIES AND MVFR POSSIBLE. NORTHWEST WINDS.
FRIDAY...VFR PROBABLE. SOUTHWEST WINDS.
MTF
&&
.MARINE...
231 PM...STRONG LOW PRESSURE WILL MOVE ALONG THE U.S. CANADIAN
BORDER TONIGHT AND BEGIN TO WEAKEN AS IT REACHES WESTERN LAKE
SUPERIOR SUNDAY AFTERNOON. ANOTHER LOW WILL DEVELOP OVER THE
SOUTHERN PLAINS TONIGHT AND MOVE NORTH TO SOUTHERN LAKE MICHIGAN
AS IT DEEPENS AND ABSORBS THE LOW OVER WESTERN LAKE SUPERIOR. THIS
LOW WILL THEN DEEPEN FURTHER AS IT REACHES EASTERN LAKE SUPERIOR
MONDAY MORNING. THERE STILL REMAINS SOME DIFFERENCES AMONG THE
MODELS REGARDING HOW STRONG THIS LOW WILL BECOME. THE DEEPEST OF
THE MODELS HAS A PRESSURE OF 28.5 INCHES MIDDAY MONDAY. CONFIDENCE
IS INCREASING FOR MID/HIGH END GALES SO WILL BE GOING WITH A GALE
WATCH FOR MONDAY AND MONDAY NIGHT. STORM FORCE GUSTS OR PREVAILING
WINDS ALSO REMAIN POSSIBLE. WINDS STEADILY DIMINISH TUESDAY AS
HIGH PRESSURE MOVES ACROSS THE SOUTHERN LAKES AND OHIO VALLEY.
ANOTHER LOW IS EXPECTED TO MOVE ACROSS THE LAKES REGION WEDNESDAY
INTO THURSDAY...BRINGING NORTHWEST WINDS TO 30KT ON THURSDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM SATURDAY.
GALE WATCH...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...6 AM MONDAY TO 3 AM TUESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...NOON MONDAY TO 3 AM TUESDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
252 PM CST Sat Nov 22 2014
.SHORT TERM...(Tonight)
ISSUED AT 252 PM CST SAT NOV 22 2014
Weakening 1031 mb high pressure drifting off eastern NC shore while
strong and deepening 985 mb low moving east into sw Sasketchewan.
This was giving a tight pressure gradient over central and southeast IL
this afternoon with very breezy ssw winds 12 to 22 mph and gusts of
25 to 30 mph. SSW winds advecting in much milder and more moist air
from western Gulf of Mexico with temperatures in the mid 50s to lower 60s
(warmest sw areas with Mount Carmel airport at 64F) and dewpoints in
the middle to upper 40s. Cloudy skies across much of central IL with
some breaks in clouds se of I-70 in southeast IL. Isolated light
rain showers over eastern IL this afternoon while showers more
numerous over sw IL from I-64 south into southern MO along and se of
I-44 where a few thunderstorm were a few hours ago. Mid level
moisture spreads northward tonight across areas se of the IL river
and this to increase chances of light rain showers though rainfall
amounts will be light due to weak lift/forcing. Also have patchy
drizzle with lower clouds over IL river valley tonight and areas of
fog overnight (currently getting fog over parts of nw IL and se IA).
Went a few degrees above similar MET/MAV guidance for lows tonight
in the mid to upper 40s due to cloud cover and southerly winds of
10-15 mph and gusts to 20 mph especially this evening.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 252 PM CST SAT NOV 22 2014
The vigorous short wave, lifting out of the southern plains will
phase with a northern stream system tomorrow; The related surface
system will strengthen over the CWA and lift northeast east tomorrow
night through Monday. The associated cold front with this system
will move through the area Monday night and bring the return to
colder air in the region for the beginning of the coming week. This
system is the main challenge with this forecast package this
afternoon. The resulting weather with this system will be for mostly
rain across the whole area tomorrow with the possibility of isolated
thunderstorms in southeastern IL, along and south of I-70, for
tomorrow afternoon through tomorrow evening. The dynamics of this
system do not look very strong, so severe storms are not expected in
southeast Illinois tomorrow afternoon or evening. Areas across the
north will see the areas of fog continuing through tomorrow and
tomorrow night. The fog will dissipate in the north once the low
pressure area moves northeast and the cold front moves through the
area, tomorrow night. The colder air that moves in Sunday night and
Monday, as the system deepens and moves northeast, will bring a
change to the p-type, resulting in rain mixing with snow in the west
Sunday night, and then becoming all snow by Monday. Snowfall
accumulations will be a half inch or less; since the pcpn will be
ending as the system moves northeast.
Temps will remain warm tomorrow but then fall from tomorrow night
through Monday night. Temps on Monday will be steady or slowly
falling in the afternoon, with the 24hr highs likely being around
midnight tomorrow night, and lows late Monday evening.
The remainder of the forecast period, through Saturday, will be
relatively dry. However, the models are bringing in a weak clipper
system Wed through Thur, that will bring a chance of snow to the
northern third of the CWA. Models are fairly consistent with the
location of the track of the low pressure area, but differ on
timing. So will still with a blend of the two models and keep the
chance of snow Wed and Wed night, as with previous forecast; and
then have a chance in the northeast parts for Thur to accommodate
the slower timing of the ECMWF.
Temps will warm some on Wed, ahead of the clipper system, but then
turn cold again after the system moves through and colder air
advects into the region again.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1155 AM CST SAT NOV 22 2014
MVFR ceilings at PIA and BMI most of this morning (just lifted to
VFR at PIA) while VFR ceilings along I-72 at midday. Meanwhile
isolated to scattered showers had shifted se of the central IL
airports at late morning. HRRR shows MVFR ceilings 2-3k ft
possible at times over central IL this afternoon especially at PIA
and BMI, and this model shifts these lower ceilings along with fog
further north of central IL this evening. Was more pestimistic
with keeping MVFR ceilings and vsbys around tonight and even lower
IFR ceilings at PIA and BMI Sunday morning. Rain showers to become
more likely later this evening/overnight with best chances
shifting into IL river valley by PIA late tonight and Sunday
morning. Breezy ssw winds 12-17 kts with gusts 18-25 kts into this
evening to veer sse Sunday morning and still gust again to 18-23
kts. Kept LLWS in TAFs again tonight until mid morning Sunday
with 2k ft sw winds of 40 kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...Auten
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
146 PM CST SAT NOV 22 2014
.UPDATE...
917 AM...MORNING UPDATE...TEMPERATURES HAVE WARMED INTO THE UPPER
30S AND LOWER 40S WITH THE THREAT OF FREEZING RAIN OVER AND LET
ADVISORY EXPIRE AT 9 AM.
FOCUS NOW SHIFTS TO THE POTENTIAL FOR DENSE FOG ACROSS THE FAR
NORTHERN AND NORTHWEST PORTIONS OF THE CWA TODAY AND TONIGHT.
VISIBILITIES CURRENTLY BETWEEN 1/2SM AND 2SM. NOT EXPECTING MUCH
IMPROVEMENT IN THESE AREAS TODAY SO ADDED FOG TO THE FORECAST...
GENERALLY NORTH OF I-80 BUT CONFIDENCE REGARDING HOW SOON DENSE
FOG MAY BECOME PREVAILING AND THEN HOW LONG IT WILL LAST IS STILL
LOW. BUT A DENSE FOG ADVISORY FOR PORTIONS OF THE NORTHERN CWA MAY
BE NEEDED LATER TODAY OR THIS EVENING. CMS
&&
.SHORT TERM...
315 AM CST
THROUGH TONIGHT...
THE PRIMARY CONCERNS WITH THE FORECAST CENTER ON FREEZING RAIN
THREAT EARLY THIS MORNING...THEN RAIN POTENTIAL AND AMOUNTS THROUGH
THE REST OF THE WEEKEND.
AN AREA OF SHOWERS IS MOVING QUICKLY NORTHEAST OVER THE IMMEDIATE
REGION AS OF 315 AM. THIS IS WITHIN STRENGTHENING FORCING FROM A
SHORT WAVE TROUGH...AND THIS GREATER LIFT IS COINCIDENT ON THE NOSE
OF A 45 KT LOW-LEVEL JET PER VAD WIND PROFILERS. OVERALL MUCH OF
THIS FORCING AND MODEST SHOWER ACTIVITY WILL CONTINUE TO SHIFT EAST
THROUGH SUNRISE. STEADILY RISING TEMPERATURES HAD LEVELED OFF SOME
VERY EARLY THIS MORNING WITH THE HEAVIER PRECIP INTENSITY...ALTHOUGH
A SLOW INCREASE SHOULD RESTART PRIOR TO DAYBREAK AND PERSIST THROUGH
TODAY AS WARM ADVECTION WINS OUT. TEMPERATURES OF 31 TO 33 AS OF
315 AM MAINLY REMAINED IN THE NORTHERN FORECAST AREA...INCLUDING
ROCKFORD AND THE NORTH CHICAGO METRO...AND PARTS OF NORTHWEST
INDIANA INCLUDING VALPARAISO. PAVEMENT TEMPERATURES FROM A HANDFUL
OF SOURCES VARIED SOME...BUT FOR THE MOST PART WERE ABOVE FREEZING
IN CHICAGO AND SOUTHWARD FROM THERE. SO WILL CONTINUE ADVISORY AS
IS FOR NOW AND MAKE A REASSESSMENT JUST PRIOR TO 6 AM TO SEE IF
ANY PARTS NEED TO CONTINUE TO 9 AM.
WHILE MUCH OF THE MODEST PRECIP SHOULD SHIFT EASTWARD EARLY THIS
MORNING...BROAD ASCENT IN THE MID-LEVELS WILL REMAIN WITH AN UPPER
SPEED MAXIMUM MOVING OVERHEAD. THIS PROBABLY WILL BE ENOUGH FOR
SCATTERED/INTERMITTENT SHOWERS ESPECIALLY THROUGH EARLY AFTERNOON.
IN THE LOWER-LEVELS...HIGH DEW POINT AIR WILL CONTINUE TO BE
ADVECTED NORTHWARD ESTABLISHING THE LOW CLOUDS. ISENTROPIC OMEGA
WITHIN THESE LOWEST LEVELS LOOKS TO SUPPORT AREAS OF DRIZZLE...AND
ALREADY SEEING INDICATIONS OF THIS NEAR THE DVN RDA. SO CONTINUE
AREAS OF DRIZZLE WORDING. TEMPERATURES WILL BE THE WARMEST THEY HAVE
BEEN SINCE LATE ON THE NIGHT OF NOVEMBER 10TH...WITH 40S EXPECTED
AREAWIDE AND EVEN 50 TAGGED SOUTH OF INTERSTATE 80 IN SOME
LOCATIONS. TONIGHT TEMPERATURES SHOULD BASICALLY HOLD STEADY AND
MAYBE EVEN RISE SOME. IF TEMPERATURES ARE ABLE TO DROP A FEW
DEGREES...THE THREAT FOR FOG BECOMES HIGHER...ALTHOUGH FORECAST
SOUNDINGS GENERALLY DO NOT LOOK TO SUPPORT ANYTHING DENSE GIVEN
THE ALREADY PRESENT LOW CLOUD DECK.
RAIN SHOULD BEGIN TO DEVELOP WITHIN GREATER MOISTURE ADVECTION AND
CONVERGENCE ACROSS CENTRAL ILLINOIS LATER TONIGHT AND SPREAD
NORTHWARD INTO THE FORECAST AREA. GREATER INTENSITY LOOKS TO BE
SEEN BEYOND TONIGHT INTO SUNDAY.
MTF
&&
.LONG TERM...
315 AM CST
SUNDAY ONWARD...
SUNDAY THE REGION WILL REMAIN IN A BROAD WARM AIR ADVECTION REGIME
AHEAD OF A PAIR OF TROUGHS APPROACHING FROM THE WEST. BROAD DEEP
SOUTHERLY FLOW WILL CONTINUE TO USHER WARMER AND INCREASINGLY MORE
MOIST AIR INTO THE REGION. BROAD ISENTROPIC ASCENT WILL CONTINUE TO
SUPPORT AT LEAST SOME OCNL SHOWERS OR DRIZZLE EARLY BEFORE BUILDING
INTO A STEADIER/HEAVIER RAIN LATER IN THE DAY AS THE STRONG SOUTHERN
STREAM SHORTWAVE BEGINS LIFTING NORTHEAST INTO THE REGION. IF EARLY
PORTION OF THE DAY ISNT TOO WET/SHOWERY THEN HIGHS COULD REACH WELL
INTO THE 50S...ESPECIALLY SOUTHERN CWA AS GUIDANCE IS FOCUSING THE
BETTER FORCING NORTH EARLY.
THE NORTHERN AND SOUTHERN STREAK SHORTWAVES ARE STILL PROGGED TO
BEGIN PHASING OVER THE WESTERN GREAT LAKES REGION SUNDAY NIGHT INTO
MONDAY. GUIDANCE CONTINUES TO SUGGEST THAT AN IMPRESSIVELY MOIST AIR
MASS WILL BE TRANSPORTED NORTH INTO THE REGION SUNDAY INTO SUNDAY.
GIVEN THE MAGNITUDE OF FORCING AND AMPLE MOISTURE WITH PWATS NEARING
2 STANDARD DEVIATIONS ABOVE AVERAGE SOME HEALTHY RAINFALL TOTALS
LOOK LIKELY...WITH AMOUNTS SUNDAY INTO SUNDAY NIGHT PROBABLY ENDING
UP CLOSE TO AN INCH. LONG DURATION OF THE PRECIP SHOULD RESULT IN
LITTLE MORE THAN MAYBE SOME MINOR PONDING OF WATER IN LOW SPOTS. RFC
CONTINGENCY FORECASTS DO SUGGEST SOME RESPECTABLE RISES ON AREA
RIVERS...THOUGH IF CURRENT QPF VERIFIES RIVERS WILL REMAIN BELOW
FLOOD STAGE.
AS NORTHERN AND SOUTHERN STREAM SYSTEMS PHASE GUIDANCE IS IN
AGREEMENT THAT THE SURFACE LOW WILL RAPIDLY...AND POTENTIALLY
EXPLOSIVELY IF THE GFS VERIFIES. THERE IS A FAIRLY LARGE SPREAD IN
MODEL GUIDANCE WRT JUST HOW DEEP THE LOW GETS MONDAY AFTERNOON WITH
THE GFS AND SEVERAL OF ITS ENSEMBLE MEMBERS IN THE BETWEEN 961 AND
966MB...WHILE THE ECMWF IS A STILL IMPRESSIVE BUT LESS EXTREME 979.
LACK OF STRONG HIGH PRESSURE IN THE WAKE OF THIS SYSTEM WILL
MITIGATE THE MAGNITUDE OF THE WINDS SOME...BUT LATEST GUIDANCE HAS
TRENDED STRONGER WITH WINDS AGAIN MONDAY. STILL POSSIBLE THERE WILL
BE SOME WAFFLING IN GUIDANCE FOR THE MONDAY TIME RANGE AS MODELS
OFTEN STRUGGLE WITH PHASING SYSTEMS...BUT HAVE FOLLOWED THE TREND
FROM THE DAY SHIFT OF STRONGER WINDS MONDAY WITH GUSTS OF 35-40 MPH
POSSIBLE. IF THE MORE EXTREME GFS MODEL CAMP VERIFIES THEN GUSTS
COULD NEAR ADVISORY CRITERIA MONDAY...A TREND WORTH WATCHING THE
NEXT COUPLE DAYS.
WARM CONVEYOR BELT PRECIP SHOULD GET SHUNTED NORTH OF THE AREA LATER
SUNDAY NIGHT...HOWEVER MODELS SUGGEST THAT DEFORMATION PRECIP COULD
POTENTIALLY WRAP AS FAR SOUTH AS OUR CWA MONDAY...ESPECIALLY
NORTHERN CWA. COLDER AIR WILL COME FLOODING IN ON THE STRONG
WESTERLY WINDS MEANING ANY DEFO PRECIP THAT DOES FALL WOULD
TRANSITION TO SNOW/SNOW SHOWERS MONDAY MORNING. FAR TOO SOON TO HAVE
MUCH CONFIDENCE IN ANY POTENTIAL ACCUMS...BUT BETTER THREAT OF SNOW
ACCUMS LOOKS TO REMAIN NORTH OF THE AREA WITH ACCUMS...IF
ANY...PROBABLY ON THE LIGHT SIDE IN OUR AREA.
STRATUS DECK LIKELY GETS LOCKED IN MONDAY NIGHT TEMPERING THE LOW
TEMPS A BIT BUT MAGNITUDE OF THE COLD AIR ADVECTION SHOULD STILL
ALLOW 20S ACROSS THE AREA. CLOUD COVER MAY STICK AROUND INTO A GOOD
CHUNK OF THE DAY TUESDAY AS THE HEART OF THE COLD AIR MASS TRAVERSES
THE AREA WHICH LOOKS TO RESULT IN VERY LITTLE TEMP RECOVERY FROM
OVERNIGHT LOWS TUESDAY MORNING.
BRIEF AND SOMEWHAT MUTED SHOT OF WARM AIR ADVECTION TUESDAY NIGHT
INTO WEDNESDAY SHOULD OCCUR AHEAD OF A CLIPPER SYSTEM...POTENTIALLY
BRINGING SOME LIGHT SNOW TO THE AREA WEDNESDAY. MEDIUM RANGE
GUIDANCE VARIES WITH RESPECT TO THE TRACK OF THIS SYSTEM SO
MAINTAINING POPS IN THE LOWER END OF THE CHANCE SPECTRUM FOR NOW.
APPEARS LIKELY THAT ANOTHER BLAST OF UNSEASONABLY COLD AIR WILL
FOLLOW THIS CLIPPER IN TIME FOR THANKSGIVING AND THE START OF THE
LONG HOLIDAY WEEKEND WITH HIGHS ONCE AGAIN HEADING BACK DOWN INTO
THE 20S.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* PATCHY IFR CIGS...TO LOW END MVFR CIGS THIS AFTN. LIKELY
TRENDING BACK TOWARDS IFR OVERNIGHT THRU SUN MORNING.
* VSBY WILL HOVER BETWEEN 3-6SM THIS AFTN...POSSIBLY FALLING TO
JUST UNDER 3SM OVERNIGHT THRU SUN MORNING.
* LOW-LEVEL WIND SHEAR DEVELOPING TONIGHT. ARND 2KFT AGL FROM THE
SOUTHWEST NEARING 45KT.
* RAIN SHOWERS DEVELOPING EARLY SUN MORNING...INCREASING IN
COVERAGE CLOSER TO MIDDAY.
BEACHLER
//DISCUSSION...UPDATED 18Z...
VERY MOIST AIR MASS CONTINUES TO FEED NORTHEAST ACROSS NORTHERN
IL/NORTHWEST IN AIRFIELDS THIS AFTERNOON. LITTLE IMPROVEMENT TO
THE CIGS IS EXPECTED...AS A RESULT HAVE HELD CIGS DOWN ARND LOW
END MVFR THIS AFTN AND WILL LIKELY TREND BACK TOWARDS IFR CONDS
OVERNIGHT. GENERALLY EXPECT CIGS ARND 500-900FT AGL THRU THE
OVERNIGHT HOURS. WIND DIR WILL NOT CHANGE MUCH THIS
AFTN/EVE/OVERNIGHT...MAINLY FROM THE SOUTH WITH SPEEDS ALSO NOT
CHANGING MUCH ARND 10-12KT. GIVEN HOW MOIST THE ATMOSPHERE
IS...PERIODIC ROUNDS OF DRIZZLE CAN BE EXPECTED THRU THIS
AFTN/EARLY EVE WILL A LULL LATE THIS EVE. WIND SHEAR IS ALSO
POISED TO DEVELOP THIS EVENING...WITH WINDS ARND 2KFT AGL FROM THE
SOUTHWEST INCREASING TO 40-45KT.
GUIDANCE HAS CONTINUED TO SUGGEST DEVELOPING RAIN SHOWERS AFT
MIDNIGHT/EARLY SUN...SO HAVE HELD ONTO THE MENTION OF LGT RAIN
EARLY SUN. THEN IT APPEARS THE BETER COVERAGE FOR PERHAPS MORE
STEADY RAIN WILL OCCUR LATE SUN MORNING...AND COULD PERSIST THRU
SUN AFTN.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN CIGS HOLDING AT LOW END MVFR...AND MEDIUM
CONFIDENCE ON TIMING CIGS TRENDING BACK TOWARDS IFR.
* HIGH CONFIDENCE IN WIND DIR/SPEED.
* MEDIUM CONFIDENCE IN LOW-LEVEL WIND SHEAR.
* HIGH CONFIDENCE IN DRIZZLE THRU THIS AFTN...THEN MEDIUM
CONFIDENCE IN TIMING OF ENDING THE MENTION OF DRIZZLE.
* HIGH CONFIDENCE IN LIGHT RAIN DEVELOPING EARLY SUN WITH BETTER
COVERAGE LATE SUN MORNING/AFTN. MEDIUM CONFIDENCE IN PRECISE
TIMING OF RAIN IMPACTING TAF SITES.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...RAIN AND IFR PROBABLE. SOUTHERLY WINDS.
MONDAY...CHANCE OF RAIN AND SNOW. STRONG WEST TO SOUTHWEST WINDS.
TUESDAY...MVFR CIGS POSSIBLE. WESTERLY WINDS.
WEDNESDAY...CHANCE OF SNOW AND MVFR. SOUTHWEST WINDS.
THURSDAY...FLURRIES AND MVFR POSSIBLE. NORTHWEST WINDS.
FRIDAY...VFR PROBABLE. SOUTHWEST WINDS.
MTF
&&
.MARINE...
325 AM CST
AN ACTIVE PATTERN OVER THE LAKE IS EXPECTED TO CONTINUE THROUGH THE
UPCOMING WEEK. THE SOUTHWEST GALES SEEN OVER THE LAKE EARLY THIS
MORNING WILL DIMINISH BY MID-LATE MORNING AS THE PRESSURE GRADIENT
SOMEWHAT DIMINISHES. SMALL CRAFT ADVISORY CRITERIA WINDS WILL
CONTINUE THOUGH ACROSS THE IL AND IN NEARSHORES A GOOD PART OF
THE DAY. IT DOES LOOK LIKE WIND SPEEDS WILL DIMINISH TO MORE 15-25
KT FOR THE EVENING AND THEN RE-INCREASE OVERNIGHT WHERE ANOTHER
ADVISORY MAY BE NEEDED.
MODERATELY STRONG SOUTHERLY FLOW WILL CONTINUE SUNDAY IN ADVANCE OF
THE COMPLEX LOW PRESSURE SYSTEM ORGANIZING TO OUR WEST. BY SUNDAY
NIGHT...LOW PRESSURE TRACKING EAST FROM THE NORTHERN PLAINS WILL
BEGIN TO MERGE WITH LOW PRESSURE TRACKING NORTHEAST FROM THE
SOUTHERN PLAINS. MODELS SUGGEST THIS PHASING OF THE TWO LOWS WILL
TAKE PLACE VERY NEAR LAKE MICHIGAN SUNDAY NIGHT WITH A BRIEF PERIOD
OF LIGHTER WINDS NEAR THE CENTER OF THE DEVELOPING STORM SYSTEM. THE
LOW IS FORECAST TO CONTINUE TO RAPIDLY INTENSIFY AS IT MOVES NORTH
MONDAY ALLOWING FOR WESTERLY GALES TO DEVELOP ON THE LAKE IN ITS
WAKE MONDAY. WHILE MODEL AGREE IN THE GENERAL IDEA OF A STRONG LOW
NORTH OF LAKE SUPERIOR BY MIDDAY MONDAY...THEY VARY CONSIDERABLY ON
HOW STRONG THE LOW WILL BE RANGING FROM 28.5 INCHES TO AROUND 29.0
INCHES. IF THE STRONGER SOLUTIONS WERE TO VERIFY THEN A PERIOD OF
STORM FORCE WEST WINDS COULD OCCUR MONDAY...DESPITE THE LACK OF ANY
STRONG HIGH PRESSURE MOVING IN BEHIND THE STORM. IF THE WEAKER
SOLUTIONS PAN OUT THEN LOWER END GALES WOULD STILL LIKELY OCCUR
MONDAY. IT IS LIKELY THAT A GALE WATCH WILL BE ISSUED FOR THE
MONDAY/MONDAY NIGHT TIME FRAME LATER TODAY. WINDS WILL EASE TUESDAY
AND BACK TO SOUTHERLY TUESDAY NIGHT INTO WEDNESDAY AHEAD OF A
CLIPPER BEFORE ANOTHER SHOT OF STRONG AND POSSIBLY GALE FORCE NORTH
OR NORTHWEST WINDS DEVELOP THURSDAY-ISH TIME FRAME.
MTF/IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM SATURDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1154 AM CST Sat Nov 22 2014
.UPDATE...
ISSUED AT 1045 AM CST SAT NOV 22 2014
Will update the forecast for warmer highs this afternoon as
temperatures running warmer, especially in far southeast IL with
Mount Carmel airport up to 61F at 10 am and Lawrenceville at 57F.
Much milder highs in the mid 50s to lower 60s, and mildest day
since Veterans Day Nov 11. Isolated to scattered rain showers to
occur mainly se of the IL river rest of today.
Breaks in low clouds by late morning especially along and south of
a Rushville to Lincoln to Champaign line. Isolated showers were
east of I-57 in eastern IL and lifting ne into Indiana. A few
showers and isolated thunderstorms was over southern MO and these
could lift ne into sw counties and southeast IL by this evening.
SPC has general risk of thunder later today sw of a Quincy to
Springfield to Taylorville line. Breezy ssw winds 12-18 mph and
gusts 18-25 mph bringing milder air in the upper 40s to mid 50s
(coolest readings ne counties), with Mount Carmel airport up to 61F.
Modified 1034 MB Canadian high pressure over the Carolinas and
strong 986 mb low pressure over southeast Alberta was giving a
breezy ssw winds gusting 20-30 mph with much milder and more
moist air over IL today. Streamflow originating from the western
gulf of Mexico has brought dewpoints up into the low to mid 40s
late this morning over central/se IL, a big jump from dewpoints in
the single digits and teens yesterday. Deeper mid level moisture
has shunted off to the east of IL this morning but models return
deeper mid level moisture into areas se of the IL river this
evening, so rain showers should increase in coverage tonight.
&&
.SHORT TERM...(Today)
ISSUED AT 318 AM CST SAT NOV 22 2014
Widespread showers associated with a passing short-wave have now
lifted N/NE into northern Illinois, leaving behind only isolated
showers across the KILX CWA early this morning. Central Illinois
will remain between the departing wave and a much stronger upstream
system today, resulting in limited synoptic lift and overall low
rain chances. In addition, forecast soundings indicate quite a bit
of mid-level drying in the wake of the initial short-wave, so
deep-layer moisture will be lacking for precip development as well.
As a result, have reduced PoPs into the chance category, with mainly
just very light showers or drizzle noted. Brisk southerly winds
will continue to bring warmer air into the region. Based on current
rate of temp rise, have gone at or above the warmest guidance
numbers, with afternoon highs reaching the lower to middle 50s.
&&
.LONG TERM...(Tonight through Friday)
ISSUED AT 318 AM CST SAT NOV 22 2014
After a lull in the precip today, rain chances will once again begin
to increase tonight as another short-wave approaches from the
southwest. After a full day of southerly flow, much deeper moisture
profiles will be in place by the time this particular feature
arrives. As a result, think showers will become likely across the
board overnight.
Main forecast challenges continue to revolve around the phasing of a
vigorous southern stream wave currently evident on water vapor
imagery over northwest Mexico and an approaching northern stream
system. The NAM is the only model that tends to keep the two
systems separate, so have rejected its solution in favor of the
GFS/ECMWF/GEM consensus. End result will be the development of
surface low pressure over Texas Saturday night that lifts
northeastward into Michigan by Monday morning. This particular
track will take the low along/east of the I-57 corridor Sunday
night. After the Saturday night wave exits the region, another
brief lull in precip chances may occur early Sunday morning before
much stronger lift arrives with the main system Sunday afternoon.
Given strong upper dynamics and copious amounts of atmospheric
moisture, will go with categorical PoPs across the board Sunday into
Sunday evening. While the strongest surface-based instability will
remain well to the S/SE from the Tennessee River Valley southward to
the Gulf Coast, think marginal elevated instability in the vicinity
of the deepening low pressure will be sufficient to mention isolated
thunder along/south of I-70 Sunday afternoon and evening.
Once low moves into the southern Great Lakes, strong CAA will spill
into the region late Sunday night into Monday. Most model solutions
agree that the cold air will arrive before the precip has a chance
to depart, so will continue to feature rain/snow-showers mainly
along/west of I-55 late Sunday night into Monday morning before the
low lifts further to the northeast and precip comes to an end.
After that, cold and generally dry weather will be on tap for the
remainder of the week. The only potential fly in the ointment is a
weak clipper system expected to come through by mid-week. Models
still show some minor timing discrepancies: however, signs are
pointing to Wednesday as the most favored time period for light
precip. WAA ahead of the approaching wave will likely boost temps
into the middle to upper 30s across much of the area, with lower 40s
possible far southeast. Given cold air aloft, will carry low chance
PoPs for light snow across the western half of the CWA Wednesday,
then across the east Wednesday night. Due to the weak/fast-moving
nature of this system and the marginally warm temps, am not
expecting much in the way of snow accumulation, with perhaps a
couple tenths of an inch at best. Thanksgiving Day still looks
cold and dry with highs ranging from the upper 20s north to the
middle 30s far south.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1155 AM CST SAT NOV 22 2014
MVFR ceilings at PIA and BMI most of this morning (just lifted to
VFR at PIA) while VFR ceilings along I-72 at midday. Meanwhile
isolated to scattered showers had shifted se of the central IL
airports at late morning. HRRR shows MVFR ceilings 2-3k ft
possible at times over central IL this afternoon especially at PIA
and BMI, and this model shifts these lower ceilings along with fog
further north of central IL this evening. Was more pestimistic
with keeping MVFR ceilings and vsbys around tonight and even lower
IFR ceilings at PIA and BMI Sunday morning. Rain showers to become
more likely later this evening/overnight with best chances
shifting into IL river valley by PIA late tonight and Sunday
morning. Breezy ssw winds 12-17 kts with gusts 18-25 kts into this
evening to veer sse Sunday morning and still gust again to 18-23
kts. Kept LLWS in TAFs again tonight until mid morning Sunday
with 2k ft sw winds of 40 kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
252 AM CST SAT NOV 22 2014
.UPDATE...
746 PM CST
MINOR CHANGES TO THE GOING FORECAST THIS EVENING...MAINLY SLOWING
TIMING OF PRECIP INTO THE REGION. DEWPOINTS REMAIN PRETTY DRY
ACROSS THE REGION WITH SINGLE DIGITS STILL IN PLACE NORTH OF I-80
AND LOW/MID TEENS TO THE SOUTH. REGIONAL RADAR MOSAIC SHOWS
SCATTERED SHOWERS MOVING ACROSS NE MO/SE IA INTO WEST CENTRAL IL
THIS EVENING AND SHOULD START TO OVERSPREAD OUR SOUTHWESTERN
COUNTIES BY AROUND 04Z OR SO...AND INTO THE CHICAGO AREA CLOSER TO
THE 06-07Z HOUR. LOWERED POPS A LITTLE MAINLY DUE TO LIMITED
COVERAGE NOTED UPSTREAM. WHILE TEMPERATURES HAVE SOME DOWNWARD
POTENTIAL FROM WET BULBING THIS EVENING...CLOUDS HAVE STARTED TO
MOVE OVERHEAD WITH A FEW SITES SHOWING TEMPS REBOUNDING A DEGREE
OR TWO...WITH MID/UPPER 30S NOT TOO FAR AWAY. LATEST RAP GUIDANCE
ACTUALLY HAS AIR TEMPERATURES RISING ABOVE FREEZING AROUND THE
ONSET OF PRECIP...SO IT APPEARS THE WINDOW OF POTENTIAL FREEZING
RAIN WILL REMAIN FAIRLY SHORT. WILL MAINTAIN CURRENT ADVISORY
TIMING AS EVEN A LIGHT GLAZE OF ICE CAN BE HAZARDOUS...BUT IF
ANYTHING WE MAY BE ABLE TO LET IT GO A LITTLE EARLY.
BMD
&&
.SHORT TERM...
352 PM CST
THROUGH TONIGHT...
CONDITIONS WILL REMAIN QUIET FOR THE REMAINDER OF THE AFTERNOON
UNDER MOSTLY CLEAR SKIES. LATEST SATELLITE IMAGERY SHOWS A DENSE
MASS OF CLOUD COVER ASSOCIATED WITH A SURGE OF MOISTURE CROSSING THE
MISSOURI VALLEY AND APPROACHING WRN IL. AT THE SURFACE...LATEST OBS
INDICATE DEWPOINTS RAPIDLY INCREASING INTO THE 40S AND 50S WITH THE
MOISTURE SURGE...WHILE DEWPOINTS OVER NRN IL/NWRN IN UNDER THE
MOSTLY CLEAR SKIES REMAIN IN THE SINGLE DIGITS TO THE LOWER TEENS.
THE PCPN SHIELD ASSOCIATED WITH THE APPROACHING SYSTEM WILL TAKE A
LITTLE TIME TO OVERCOME THE VERY DRY AIR IN PLACE...BUT UPSTREAM
TRENDS AND THE SHORT TERM MODEL GUIDANCE ALIGN WELL WITH THE TREND
TO BRING INCREASING POPS INTO THE FAR SWRN PORTIONS OF THE CWA AFTER
SUNSET AND THEN QUICKLY SPREADING TO THE NORTH AND EAST THROUGH THE
EVENING AND OVERNIGHT. THERE WILL BE A SLOW INCREASE IN SFC TEMPS
THROUGH THE NIGHT UNDER STRONG WARM ADVECTION DRIVEN BY A SWLY LOW
LEVEL JET TO 45KT. AVAILABLE DEEP LAYER MOISTURE WITH SYSTEM IS
LIMITED...SO ACTUAL QPF AMOUNTS EXPECTED SHOULD BE RELATIVELY
LIGHT. WILL MAINTAIN AND MAKE NO CHANGES TO THE GOING FREEZING RAIN
ADVISORY. WITH LIGHT QPF AMOUNTS EXPECTED...ANY ICE ACCUMULATION
SHOULD RANGE FROM A LIGHT GLAZING TO A LITTLE OVER A TENTH OF AN
INCH. THERE IS ALSO A CHANCE FOR SOME GLAZING AS EARLY AS 23Z-00Z
OVER THE PONTIAC AREA...WITH SOME LIGHT DRIZZLE OR LIGHT RAIN COMING
IN CONTACT WITH ROAD SURFACES AND WALKWAYS THAT ARE CURRENTLY BELOW
FREEZING DUE TO THE RECENT UNSEASONABLY COLD WEATHER. THROUGH THE
LATE EVENING AND INTO THE OVERNIGHT HOURS...THE FREEZING PCPN WILL
GRADUALLY CHANGE OVER TO A MIX OF FREEZING OR LIQUID TO ALL LIQUID
PCPN AS THE WARMER AIR SURGES INTO THE REGION LATE THIS EVENING AND
OVERNIGHT TONIGHT. THE FREEZING PCPN POTENTIAL SHOULD DIMINISH FROM
SOUTHWEST TO NORTHEAST AS THE WARMER AIR OVERSPREAD THE
REGION...WITH THE FREEZING PCPN POTENTIAL ENDING OVER THE FAR NERN
PORTIONS OF THE CWA...INCLUDING THE FAR NORTHERN PORTIONS OF THE
CHICAGO AREA BY DAYBREAK SATURDAY MORNING.
KREIN
&&
.LONG TERM...
352 PM CST
SATURDAY THROUGH FRIDAY...
FOR THE REMAINDER OF THE DAY ON SATURDAY...WITH LOW PRESSURE
DEEPENING OVER THE NRN PLAINS WHILE HIGH PRESSURE MOVES OFF THE
SOUTH EAST ATLANTIC COAST...THE PERSISTENT FETCH OF WARM...MOIST AIR
WILL CONTINUE TO STREAM OVER THE AREA...WITH LIGHT RAIN PERSISTING
THROUGH THE DAY. TEMPERATURES WILL CONTINUE TO INCREASE THROUGH THE
DAY ON SATURDAY WITH HIGHS RANGING FROM AROUND 50F OVER THE PONTIAC
AREA TO THE MIDDLE 40S OVER THE REMAINDER OF THE CWA. DEWPOINTS ARE
ALSO EXPECTED TO CONTINUE TO RISE THROUGH SATURDAY...REACHING INTO
THE MIDDLE 40S...WHICH WILL BE A STARK CONTRAST TO THE UNSEASONABLY
COLD...DRY AIR THAT HAS BEEN THE PREVAILING CONDITION FOR THE PAST
SEVERAL DAYS. WITH THE MAIN FOCUSING MECHANISM TO MAINTAIN THE PCPN
BEING WIDESPREAD...BUT GRADUAL...ISENTROPIC LIFT...RAINFALL AMOUNTS
WILL CONTINUE TO BE RELATIVELY LIGHT THROUGH SATURDAY NIGHT...WITH
WIDESPREAD AMOUNTS OF A COUPLE TENTHS OF AN INCH.
MORE SIGNIFICANT RAINFALL IS SETTING UP FOR SUNDAY AND INTO SUNDAY
NIGHT AS A STRONG SRN STREAM SHORTWAVE LIFTS OUT OF THE SOUTH HIGH
PLAINS PHASES WITH ANOTHER SHORTWAVE LIFTING FROM THE SOUTHWEST GULF
COAST REGION. THESE SYSTEM WILL RESULT IN A DEEPENING SFC LOW OVER
SRN IL BY SUNDAY EVENING AS A NRN STREAM SHORTWAVE TRACKS ACROSS THE
NRN PLAINS TO THE WRN GREAT LAKE REGION. THE SRN STREAM SYSTEM WILL
BE THE PRIMARY FOCUS FOR HEAVIER RAIN. THE MODELS CONTINUE TO
INDICATE ALMOST UNPRECEDENTED LEVELS OF DEEP LAYER MOISTURE FOR LATE
NOVEMBER...WITH PWATS INCREASING TO IN EXCESS OF 1 INCH THROUGH THE
DAY ON SUNDAY. WHILE ANY THUNDER REMAINS UNLIKELY DUE TO A LACK OF
INSOLATION UNDER PERSISTENT CLOUD COVER...THE UNUSUALLY HIGH
MOISTURE CONTENT SHOULD BRING AREAS OF FOG THROUGH SUNDAY AS WELL AS
SOME LOCALLY HEAVY RAINFALL. WIDESPREAD RAINFALL OF 1 TO 1.5 INCHES
IS POSSIBLE FOR SUNDAY THROUGH SUNDAY NIGHT WITH LOCALIZED AREAS OF
EVEN HEAVIER RAIN POSSIBLE IS SOME CONVECTIVE ELEMENTS CAN DEVELOP.
CONDITIONS WILL REMAIN MUCH WARMER/MOISTER THAN RECENT DAYS THROUGH
SUNDAY WITH HIGHS ONCE AGAIN EXPECTED TO BE IN THE UPPER 40S TO
AROUND 50F.
THE MODELS HAVE SETTLED INTO A RELATIVELY CONSISTENT SOLUTION OF
PHASING THE NRN AND SRN STREAM SHORTWAVES OVER THE ERN GREAT LAKES
BY MONDAY MORNING WITH A SFC LOW ARND 980MB DEVELOPING. AS THE LOW
DEEPENS FURTHER ON MONDAY...STRONG WEST WINDS WILL DEVELOP OVER THE
AREA WITH WINDS INCREASING TO ARND 25 MPH WITH 35MPH GUSTS.
CONSIDERING A POSSIBILITY THAT THE MODELS COULD EVEN BE UNDER
FORECASTING THE POTENTIAL DEEPENING OF THIS LOW...WHICH IS A
POSSIBILITY GIVEN THE LATE FALL CONTRAST OF WARM...MOIST GULF AIR
ASSOCIATED WITH THE SRN STREAM SYSTEM AND MUCH COLDER AIR WITH THE
NRN STREAM SYSTEM...THERE IS THE CHANCE THAT WIND ADVISORY CRITERIA
WINDS OF SUSTAINED 30 MPH WINDS WITH 45 MPH GUSTS MAY OCCUR ON
MONDAY.
THE DEEP SFC LOW IS EXPECTED TO LIFT OUT TO THE NORTHEAST MONDAY
NIGHT AND TUESDAY...WEAK HIGH PRESSURE WILL BUILD ACROSS THE PLAINS
AS THE SFC WHILE BROAD UPPER TROUGHING DEVELOPS OVER THE CNTRL
CONUS. THE UPPER LEVEL PATTERN IS EXPECTED TO BECOME MORE
AMPLIFIED...BUT SLOWLY PROGRESSIVE BY MIDWEEK THROUGH THE END OF NEXT
WEEK...THE AREA REMAINING UNDER PERSISTENT NWLY FLOW AND COLD
ADVECTION ALOFT. SO THE WEEKEND WARMUP SHOULD COME TO AN ABRUPT END
BY MONDAY AS A STRONG COLD FRONT PASSES THROUGH THE REGION AND
TEMPERATURES DROP BACK INTO THE UPPER 30S TO ARND 40F ON MONDAY WITH
HIGHS ONLY IN THE UPPER 20S TO LOWER 30S FOR TUESDAY. THROUGH THE
REMAINDER OF NEXT WEEK...THE TEMPERATURE TREND WILL GO BACK TO WELL
BELOW NORMAL...WITH HIGHS ON THANKSGIVING ONLY IN THE LOWER TO
MIDDLE 20S. A WEAK CLIPPER-TYPE SYSTEM DROPPING OUT OF THE NRN
ROCKIES ON TUESDAY IS EXPECTED TO DIVE INTO THE LOWER MISSISSIPPI
VALLEY BY WEDNESDAY AS ANOTHER WEAK SHORTWAVE DROPS THROUGH THE
UPPER GREAT LAKES. THIS COULD BRING SOME LIGHT SNOW FOR
WEDNESDAY...BUT THEN STRONG HIGH PRESSURE SHOULD BUILD ACROSS THE
MIDDLE MISSISSIPPI VALLEY THROUGH THE GREAT LAKES. THIS COULD SET
UP A WEAK PRESSURE GRADIENT PATTERN OVER THE REGION...BRINGING THE
POSSIBILITY FOR A LAKE EFFECT PLUME TO DEVELOP OVER LAKE MICHIGAN.
WHILE IT IS STILL WAY TOO EARLY TO CONSIDER THE FINER DETAILS OF
LAKE EFFECT SNOW ASSOCIATED WITH MESOSCALE BANDING OF A LAKE
PLUME...THE PATTERN WOULD BE CONDUCIVE FOR SUCH TYPE OF DEVELOPMENT.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* A SMALL CHANCE OF TEMPORARY LIGHT FZRA POSSIBLE PRIOR TO
11Z...THOUGH BASED ON PAVEMENT TEMPERATURES THIS SEEMS MORE
UNLIKELY.
* CIGS LOWERING TO IFR BY DAYBREAK AND THEN POTENTIALLY PERSISTING
AT THAT LEVEL THROUGH THE REMAINDER OF THE TAF.
* IFR VISIBILITY IN DRIZZLE THIS MORNING WITH INTERMITTENT
SHOWERS...ESPECIALLY THE MORNING AND EARLY AFTERNOON.
//DISCUSSION...UPDATED 06Z...
SCATTERED SHOWERS WILL MOVE NORTHEAST OVER THE REGION THROUGH 10Z-
12Z. COVERAGE OF THESE WILL LIKELY INCREASE SOME BUT OVERALL
REMAIN SCATTERED AND GIVEN THE FORCING...WILL ALSO REMAIN MAINLY
LIGHT IN INTENSITY. SOUTHERLY WINDS ARE CONTINUING TO STEER IN
GRADUALLY WARMING TEMPERATURES AS WE PASS THE MIDNIGHT HOUR. IT IS
LIKELY MOST OF THE AIRFIELDS AIR TEMPERATURES WILL REMAIN ABOVE
FREEZING AS SHOWER INTENSITY SHOULD NOT BE ENOUGH TO BRING
TEMPERATURES DOWN TO WET BULB VALUES. HOWEVER...PAVEMENT
TEMPERATURES ARE SLIGHTLY SLOWER TO RESPOND. THIS MAY LEAD TO
LIGHT FREEZING ON SURFACES BEFORE THEY WARM TO OVER 32. BY
DAYBREAK...THE SHOWER ACTIVITY SHOULD HAVE FURTHER DIMINISHED IN
COVERAGE WITH THE PASSAGE OF AN UPPER LEVEL DISTURBANCE...HOWEVER
MOISTENING LOW-LEVELS SHOULD PROVIDE AREAS OF DRIZZLE. IN
TANDEM...CIGS WILL BE FURTHER LOWERING INTO THE IFR CATEGORY AND
VISIBILITY MAY FOLLOW. IFR CIGS MAY PERSIST THROUGH ALL OF SATURDAY
AND EVEN IF THEY DO NOT THEY ARE LIKELY TO RETURN SATURDAY NIGHT.
RAIN SHOULD BE SPREADING NORTHWARD OVER THE AREA DURING OVERNIGHT
SATURDAY NIGHT.
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH IN SHOWERS...AT TIMES MODERATE IN INTENSITY...THROUGH 11Z
WITH INTERMITTENT SHOWERS IN DRIZZLE AFTER. CONFIDENCE IS HIGH
THAT FREEZING RAIN THREAT HAS DIMINISHED BASED ON WARMED
PAVEMENT TEMPERATURES.
* HIGH IN IFR CIGS THIS MORNING AND THAT THEY WILL FALL TO AT
LEAST 700 FT. LOW ON JUST HOW FAR THEY WILL DROP AND HOW LONG
THEY WILL PERSIST...WITH THE POTENTIAL IT COULD BE THE ENTIRE
TAF DURATION.
* MEDIUM IN DRIZZLE OCCURRING TODAY BUT LOW IN HOW FAR VISIBILITY
WILL DROP WITH IFR POSSIBLE.
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...RAIN. HEAVY AT TIMES. IFR LIKELY. GUSTY S TO SE WINDS.
MONDAY...CHANCE -RASN EARLY AND -SN LATER. MVFR CIGS POSSIBLE.
GUSTY W TO SW WINDS.
TUESDAY...CHANCE OF FLURRIES. MVFR CIGS PSBL. BREEZY WEST WINDS.
WEDNESDAY...LIGHT SNOW POSSIBLE. MVFR CIGS/VIS POSSIBLE. WEST TO
SOUTHWEST WINDS 10 KT OR LESS.
THANKSGIVING DAY...VFR LIKELY.
MTF
&&
.MARINE...
242 PM...HIGH PRESSURE OVER THE SOUTHERN LAKES AND OHIO VALLEY
WILL MOVE SOUTHEAST TONIGHT REACHING THE CAROLINA COAST ON
SATURDAY AS LOW PRESSURE MOVES ACROSS NORTHERN ONTARIO AND JAMES
BAY TONIGHT. THE GRADIENT BETWEEN THESE TWO SYSTEMS WILL STEADILY
INCREASE OVER LAKE MICHIGAN TONIGHT WITH GALE FORCE WINDS
EXPECTED...POSSIBLY GUSTING AS HIGH AS 45KTS ACROSS THE NORTHERN
PORTION OF THE LAKE. THE GRADIENT WILL BEGIN TO WEAKEN LATER
SATURDAY AFTERNOON INTO SATURDAY EVENING...BUT ANOTHER LOW MOVING
ACROSS THE NORTHERN PLAINS SATURDAY NIGHT INTO SUNDAY WILL TIGHTEN
THE SOUTHERLY GRADIENT AGAIN. THIS LOW WILL BEGIN TO WEAKEN SUNDAY
EVENING AND THEN BE ABSORBED BY ANOTHER STRONGER LOW WHICH WILL
DEVELOP OVER THE SOUTHERN PLAINS SATURDAY NIGHT INTO SUNDAY...THEN
MOVE NORTH ACROSS LAKE MICHIGAN SUNDAY NIGHT INTO MONDAY MORNING.
THIS LOW HAS BEEN FORECAST TO DEEPEN TO AS LOW AS 975MB NEAR LAKE
SUPERIOR FOR SEVERAL DAYS. IF THIS OCCURS...WESTERLY HIGH END
GALES TO 45 KTS WOULD LIKELY DEVELOP MONDAY WITH THE POTENTIAL FOR
SOME STORM FORCE WINDS OR GUSTS. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FREEZING RAIN ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012 UNTIL 9 AM SATURDAY.
FREEZING RAIN ADVISORY...ILZ019-ILZ020 UNTIL 6 AM SATURDAY.
IN...FREEZING RAIN ADVISORY...INZ002-INZ011 UNTIL 6 AM SATURDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM SATURDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM SATURDAY.
&&
$$
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
1143 PM CST FRI NOV 21 2014
.UPDATE...
746 PM CST
MINOR CHANGES TO THE GOING FORECAST THIS EVENING...MAINLY SLOWING
TIMING OF PRECIP INTO THE REGION. DEWPOINTS REMAIN PRETTY DRY
ACROSS THE REGION WITH SINGLE DIGITS STILL IN PLACE NORTH OF I-80
AND LOW/MID TEENS TO THE SOUTH. REGIONAL RADAR MOSAIC SHOWS
SCATTERED SHOWERS MOVING ACROSS NE MO/SE IA INTO WEST CENTRAL IL
THIS EVENING AND SHOULD START TO OVERSPREAD OUR SOUTHWESTERN
COUNTIES BY AROUND 04Z OR SO...AND INTO THE CHICAGO AREA CLOSER TO
THE 06-07Z HOUR. LOWERED POPS A LITTLE MAINLY DUE TO LIMITED
COVERAGE NOTED UPSTREAM. WHILE TEMPERATURES HAVE SOME DOWNWARD
POTENTIAL FROM WET BULBING THIS EVENING...CLOUDS HAVE STARTED TO
MOVE OVERHEAD WITH A FEW SITES SHOWING TEMPS REBOUNDING A DEGREE
OR TWO...WITH MID/UPPER 30S NOT TOO FAR AWAY. LATEST RAP GUIDANCE
ACTUALLY HAS AIR TEMPERATURES RISING ABOVE FREEZING AROUND THE
ONSET OF PRECIP...SO IT APPEARS THE WINDOW OF POTENTIAL FREEZING
RAIN WILL REMAIN FAIRLY SHORT. WILL MAINTAIN CURRENT ADVISORY
TIMING AS EVEN A LIGHT GLAZE OF ICE CAN BE HAZARDOUS...BUT IF
ANYTHING WE MAY BE ABLE TO LET IT GO A LITTLE EARLY.
BMD
&&
.SHORT TERM...
352 PM CST
THROUGH TONIGHT...
CONDITIONS WILL REMAIN QUIET FOR THE REMAINDER OF THE AFTERNOON
UNDER MOSTLY CLEAR SKIES. LATEST SATELLITE IMAGERY SHOWS A DENSE
MASS OF CLOUD COVER ASSOCIATED WITH A SURGE OF MOISTURE CROSSING THE
MISSOURI VALLEY AND APPROACHING WRN IL. AT THE SURFACE...LATEST OBS
INDICATE DEWPOINTS RAPIDLY INCREASING INTO THE 40S AND 50S WITH THE
MOISTURE SURGE...WHILE DEWPOINTS OVER NRN IL/NWRN IN UNDER THE
MOSTLY CLEAR SKIES REMAIN IN THE SINGLE DIGITS TO THE LOWER TEENS.
THE PCPN SHIELD ASSOCIATED WITH THE APPROACHING SYSTEM WILL TAKE A
LITTLE TIME TO OVERCOME THE VERY DRY AIR IN PLACE...BUT UPSTREAM
TRENDS AND THE SHORT TERM MODEL GUIDANCE ALIGN WELL WITH THE TREND
TO BRING INCREASING POPS INTO THE FAR SWRN PORTIONS OF THE CWA AFTER
SUNSET AND THEN QUICKLY SPREADING TO THE NORTH AND EAST THROUGH THE
EVENING AND OVERNIGHT. THERE WILL BE A SLOW INCREASE IN SFC TEMPS
THROUGH THE NIGHT UNDER STRONG WARM ADVECTION DRIVEN BY A SWLY LOW
LEVEL JET TO 45KT. AVAILABLE DEEP LAYER MOISTURE WITH SYSTEM IS
LIMITED...SO ACTUAL QPF AMOUNTS EXPECTED SHOULD BE RELATIVELY
LIGHT. WILL MAINTAIN AND MAKE NO CHANGES TO THE GOING FREEZING RAIN
ADVISORY. WITH LIGHT QPF AMOUNTS EXPECTED...ANY ICE ACCUMULATION
SHOULD RANGE FROM A LIGHT GLAZING TO A LITTLE OVER A TENTH OF AN
INCH. THERE IS ALSO A CHANCE FOR SOME GLAZING AS EARLY AS 23Z-00Z
OVER THE PONTIAC AREA...WITH SOME LIGHT DRIZZLE OR LIGHT RAIN COMING
IN CONTACT WITH ROAD SURFACES AND WALKWAYS THAT ARE CURRENTLY BELOW
FREEZING DUE TO THE RECENT UNSEASONABLY COLD WEATHER. THROUGH THE
LATE EVENING AND INTO THE OVERNIGHT HOURS...THE FREEZING PCPN WILL
GRADUALLY CHANGE OVER TO A MIX OF FREEZING OR LIQUID TO ALL LIQUID
PCPN AS THE WARMER AIR SURGES INTO THE REGION LATE THIS EVENING AND
OVERNIGHT TONIGHT. THE FREEZING PCPN POTENTIAL SHOULD DIMINISH FROM
SOUTHWEST TO NORTHEAST AS THE WARMER AIR OVERSPREAD THE
REGION...WITH THE FREEZING PCPN POTENTIAL ENDING OVER THE FAR NERN
PORTIONS OF THE CWA...INCLUDING THE FAR NORTHERN PORTIONS OF THE
CHICAGO AREA BY DAYBREAK SATURDAY MORNING.
KREIN
&&
.LONG TERM...
352 PM CST
SATURDAY THROUGH FRIDAY...
FOR THE REMAINDER OF THE DAY ON SATURDAY...WITH LOW PRESSURE
DEEPENING OVER THE NRN PLAINS WHILE HIGH PRESSURE MOVES OFF THE
SOUTH EAST ATLANTIC COAST...THE PERSISTENT FETCH OF WARM...MOIST AIR
WILL CONTINUE TO STREAM OVER THE AREA...WITH LIGHT RAIN PERSISTING
THROUGH THE DAY. TEMPERATURES WILL CONTINUE TO INCREASE THROUGH THE
DAY ON SATURDAY WITH HIGHS RANGING FROM AROUND 50F OVER THE PONTIAC
AREA TO THE MIDDLE 40S OVER THE REMAINDER OF THE CWA. DEWPOINTS ARE
ALSO EXPECTED TO CONTINUE TO RISE THROUGH SATURDAY...REACHING INTO
THE MIDDLE 40S...WHICH WILL BE A STARK CONTRAST TO THE UNSEASONABLY
COLD...DRY AIR THAT HAS BEEN THE PREVAILING CONDITION FOR THE PAST
SEVERAL DAYS. WITH THE MAIN FOCUSING MECHANISM TO MAINTAIN THE PCPN
BEING WIDESPREAD...BUT GRADUAL...ISENTROPIC LIFT...RAINFALL AMOUNTS
WILL CONTINUE TO BE RELATIVELY LIGHT THROUGH SATURDAY NIGHT...WITH
WIDESPREAD AMOUNTS OF A COUPLE TENTHS OF AN INCH.
MORE SIGNIFICANT RAINFALL IS SETTING UP FOR SUNDAY AND INTO SUNDAY
NIGHT AS A STRONG SRN STREAM SHORTWAVE LIFTS OUT OF THE SOUTH HIGH
PLAINS PHASES WITH ANOTHER SHORTWAVE LIFTING FROM THE SOUTHWEST GULF
COAST REGION. THESE SYSTEM WILL RESULT IN A DEEPENING SFC LOW OVER
SRN IL BY SUNDAY EVENING AS A NRN STREAM SHORTWAVE TRACKS ACROSS THE
NRN PLAINS TO THE WRN GREAT LAKE REGION. THE SRN STREAM SYSTEM WILL
BE THE PRIMARY FOCUS FOR HEAVIER RAIN. THE MODELS CONTINUE TO
INDICATE ALMOST UNPRECEDENTED LEVELS OF DEEP LAYER MOISTURE FOR LATE
NOVEMBER...WITH PWATS INCREASING TO IN EXCESS OF 1 INCH THROUGH THE
DAY ON SUNDAY. WHILE ANY THUNDER REMAINS UNLIKELY DUE TO A LACK OF
INSOLATION UNDER PERSISTENT CLOUD COVER...THE UNUSUALLY HIGH
MOISTURE CONTENT SHOULD BRING AREAS OF FOG THROUGH SUNDAY AS WELL AS
SOME LOCALLY HEAVY RAINFALL. WIDESPREAD RAINFALL OF 1 TO 1.5 INCHES
IS POSSIBLE FOR SUNDAY THROUGH SUNDAY NIGHT WITH LOCALIZED AREAS OF
EVEN HEAVIER RAIN POSSIBLE IS SOME CONVECTIVE ELEMENTS CAN DEVELOP.
CONDITIONS WILL REMAIN MUCH WARMER/MOISTER THAN RECENT DAYS THROUGH
SUNDAY WITH HIGHS ONCE AGAIN EXPECTED TO BE IN THE UPPER 40S TO
AROUND 50F.
THE MODELS HAVE SETTLED INTO A RELATIVELY CONSISTENT SOLUTION OF
PHASING THE NRN AND SRN STREAM SHORTWAVES OVER THE ERN GREAT LAKES
BY MONDAY MORNING WITH A SFC LOW ARND 980MB DEVELOPING. AS THE LOW
DEEPENS FURTHER ON MONDAY...STRONG WEST WINDS WILL DEVELOP OVER THE
AREA WITH WINDS INCREASING TO ARND 25 MPH WITH 35MPH GUSTS.
CONSIDERING A POSSIBILITY THAT THE MODELS COULD EVEN BE UNDER
FORECASTING THE POTENTIAL DEEPENING OF THIS LOW...WHICH IS A
POSSIBILITY GIVEN THE LATE FALL CONTRAST OF WARM...MOIST GULF AIR
ASSOCIATED WITH THE SRN STREAM SYSTEM AND MUCH COLDER AIR WITH THE
NRN STREAM SYSTEM...THERE IS THE CHANCE THAT WIND ADVISORY CRITERIA
WINDS OF SUSTAINED 30 MPH WINDS WITH 45 MPH GUSTS MAY OCCUR ON
MONDAY.
THE DEEP SFC LOW IS EXPECTED TO LIFT OUT TO THE NORTHEAST MONDAY
NIGHT AND TUESDAY...WEAK HIGH PRESSURE WILL BUILD ACROSS THE PLAINS
AS THE SFC WHILE BROAD UPPER TROUGHING DEVELOPS OVER THE CNTRL
CONUS. THE UPPER LEVEL PATTERN IS EXPECTED TO BECOME MORE
AMPLIFIED...BUT SLOWLY PROGRESSIVE BY MIDWEEK THROUGH THE END OF NEXT
WEEK...THE AREA REMAINING UNDER PERSISTENT NWLY FLOW AND COLD
ADVECTION ALOFT. SO THE WEEKEND WARMUP SHOULD COME TO AN ABRUPT END
BY MONDAY AS A STRONG COLD FRONT PASSES THROUGH THE REGION AND
TEMPERATURES DROP BACK INTO THE UPPER 30S TO ARND 40F ON MONDAY WITH
HIGHS ONLY IN THE UPPER 20S TO LOWER 30S FOR TUESDAY. THROUGH THE
REMAINDER OF NEXT WEEK...THE TEMPERATURE TREND WILL GO BACK TO WELL
BELOW NORMAL...WITH HIGHS ON THANKSGIVING ONLY IN THE LOWER TO
MIDDLE 20S. A WEAK CLIPPER-TYPE SYSTEM DROPPING OUT OF THE NRN
ROCKIES ON TUESDAY IS EXPECTED TO DIVE INTO THE LOWER MISSISSIPPI
VALLEY BY WEDNESDAY AS ANOTHER WEAK SHORTWAVE DROPS THROUGH THE
UPPER GREAT LAKES. THIS COULD BRING SOME LIGHT SNOW FOR
WEDNESDAY...BUT THEN STRONG HIGH PRESSURE SHOULD BUILD ACROSS THE
MIDDLE MISSISSIPPI VALLEY THROUGH THE GREAT LAKES. THIS COULD SET
UP A WEAK PRESSURE GRADIENT PATTERN OVER THE REGION...BRINGING THE
POSSIBILITY FOR A LAKE EFFECT PLUME TO DEVELOP OVER LAKE MICHIGAN.
WHILE IT IS STILL WAY TOO EARLY TO CONSIDER THE FINER DETAILS OF
LAKE EFFECT SNOW ASSOCIATED WITH MESOSCALE BANDING OF A LAKE
PLUME...THE PATTERN WOULD BE CONDUCIVE FOR SUCH TYPE OF DEVELOPMENT.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* TEMPORARY LIGHT FZRA POSSIBLE PRIOR TO 09Z-10Z...WITH GRADUALLY
WARMING TEMPERATURES LIKELY YIELDING TEMPORARY -SHRA AFTER THAT
POINT THROUGH DAYBREAK.
* CIGS GRADUALLY LOWERING TO IFR BY DAYBREAK AND POTENTIALLY
PERSISTING THROUGH THE REMAINDER OF THE TAF.
* IFR VISIBILITY IN DRIZZLE POSSIBLE SATURDAY...ESPECIALLY THE
MORNING AND EARLY AFTERNOON.
//DISCUSSION...UPDATED 06Z...
SCATTERED SHOWERS WILL MOVE NORTHEAST OVER THE REGION THROUGH 10Z-
12Z. COVERAGE OF THESE WILL LIKELY INCREASE SOME BUT OVERALL
REMAIN SCATTERED AND GIVEN THE FORCING...WILL ALSO REMAIN MAINLY
LIGHT IN INTENSITY. SOUTHERLY WINDS ARE CONTINUING TO STEER IN
GRADUALLY WARMING TEMPERATURES AS WE PASS THE MIDNIGHT HOUR. IT IS
LIKELY MOST OF THE AIRFIELDS AIR TEMPERATURES WILL REMAIN ABOVE
FREEZING AS SHOWER INTENSITY SHOULD NOT BE ENOUGH TO BRING
TEMPERATURES DOWN TO WET BULB VALUES. HOWEVER...PAVEMENT
TEMPERATURES ARE SLIGHTLY SLOWER TO RESPOND. THIS MAY LEAD TO
LIGHT FREEZING ON SURFACES BEFORE THEY WARM TO OVER 32. BY
DAYBREAK...THE SHOWER ACTIVITY SHOULD HAVE FURTHER DIMINISHED IN
COVERAGE WITH THE PASSAGE OF AN UPPER LEVEL DISTURBANCE...HOWEVER
MOISTENING LOW-LEVELS SHOULD PROVIDE AREAS OF DRIZZLE. IN
TANDEM...CIGS WILL BE FURTHER LOWERING INTO THE IFR CATEGORY AND
VISIBILITY MAY FOLLOW. IFR CIGS MAY PERSIST THROUGH ALL OF SATURDAY
AND EVEN IF THEY DO NOT THEY ARE LIKELY TO RETURN SATURDAY NIGHT.
RAIN SHOULD BE SPREADING NORTHWARD OVER THE AREA DURING OVERNIGHT
SATURDAY NIGHT.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH IN LIGHT SHOWERS OCCURRING AND TIMING BUT LOW IN WHETHER IT
WILL FREEZE AS AIR TEMPERATURES WILL LIKELY BE ABOVE 32 AND ANY
FREEZING WILL DEPEND HEAVILY ON PAVEMENT TEMPERATURES.
* HIGH IN IFR CIGS SATURDAY MORNING AND MEDIUM IN HOW FAR THEY
WILL DROP.
* MEDIUM IN DRIZZLE OCCURRING SATURDAY BUT LOW IN HOW FAR
VISIBILITY WILL DROP WITH IFR POSSIBLE.
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...RAIN. HEAVY AT TIMES. IFR LIKELY. GUSTY S TO SE WINDS.
MONDAY...CHANCE -RASN EARLY AND -SN LATER. MVFR CIGS POSSIBLE.
GUSTY W TO SW WINDS.
TUESDAY...CHANCE OF FLURRIES. MVFR CIGS PSBL. BREEZY WEST WINDS.
WEDNESDAY...LIGHT SNOW POSSIBLE. MVFR CIGS/VIS POSSIBLE. WEST TO
SOUTHWEST WINDS 10 KT OR LESS.
THANKSGIVING DAY...VFR LIKELY.
MTF
&&
.MARINE...
242 PM...HIGH PRESSURE OVER THE SOUTHERN LAKES AND OHIO VALLEY
WILL MOVE SOUTHEAST TONIGHT REACHING THE CAROLINA COAST ON
SATURDAY AS LOW PRESSURE MOVES ACROSS NORTHERN ONTARIO AND JAMES
BAY TONIGHT. THE GRADIENT BETWEEN THESE TWO SYSTEMS WILL STEADILY
INCREASE OVER LAKE MICHIGAN TONIGHT WITH GALE FORCE WINDS
EXPECTED...POSSIBLY GUSTING AS HIGH AS 45KTS ACROSS THE NORTHERN
PORTION OF THE LAKE. THE GRADIENT WILL BEGIN TO WEAKEN LATER
SATURDAY AFTERNOON INTO SATURDAY EVENING...BUT ANOTHER LOW MOVING
ACROSS THE NORTHERN PLAINS SATURDAY NIGHT INTO SUNDAY WILL TIGHTEN
THE SOUTHERLY GRADIENT AGAIN. THIS LOW WILL BEGIN TO WEAKEN SUNDAY
EVENING AND THEN BE ABSORBED BY ANOTHER STRONGER LOW WHICH WILL
DEVELOP OVER THE SOUTHERN PLAINS SATURDAY NIGHT INTO SUNDAY...THEN
MOVE NORTH ACROSS LAKE MICHIGAN SUNDAY NIGHT INTO MONDAY MORNING.
THIS LOW HAS BEEN FORECAST TO DEEPEN TO AS LOW AS 975MB NEAR LAKE
SUPERIOR FOR SEVERAL DAYS. IF THIS OCCURS...WESTERLY HIGH END
GALES TO 45 KTS WOULD LIKELY DEVELOP MONDAY WITH THE POTENTIAL FOR
SOME STORM FORCE WINDS OR GUSTS. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FREEZING RAIN ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ020-ILZ022 UNTIL 9 AM
SATURDAY.
FREEZING RAIN ADVISORY...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-
ILZ039 UNTIL 6 AM SATURDAY.
IN...FREEZING RAIN ADVISORY...INZ001-INZ002 UNTIL 9 AM SATURDAY.
FREEZING RAIN ADVISORY...INZ010-INZ011-INZ019 UNTIL 6 AM
SATURDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM SATURDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM SATURDAY.
&&
$$
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 INDIANAPOLIS IN
959 PM EST SUN NOV 23 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 307 PM EST SUN NOV 23 2014
AN AREA OF LOW PRESSURE AND A COLD FRONT WILL BRING RAIN TO CENTRAL
INDIANA TONIGHT INTO MONDAY. BEHIND THE FRONT WILL COME WINDY AND
MUCH COLDER CONDITIONS. ANOTHER SYSTEM COULD BRING SOME LIGHT RAIN
AND SNOW TO THE AREA ON WEDNESDAY. THANKSGIVING INTO SATURDAY WILL
BE COLD AND DRY BEFORE ANOTHER SYSTEM BRINGS LOW CHANCES FOR
PRECIPITATION SUNDAY.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 959 PM EST SUN NOV 23 2014
DUAL AREAS OF LOW PRESSURE CURRENTLY IN THE PROCESS OF COALESCING
ACROSS CENTRAL ILLINOIS AND INTENSIFYING. A WARM FRONT EXTENDS
SOUTHEAST FROM THE DOUBLE BARRELED LOW INTO THE SOUTHERN
APPALACHIANS WITH A LARGE AREA OF MODERATE TO OCCASIONALLY HEAVY
RAINFALL ENCOMPASSING MUCH OF THE FORECAST AREA NORTH OF THE
FRONT. TEMPS WERE IN THE LOWER AND MIDDLE 50S AS OF 0230Z.
FORECAST IS IN REALLY GOOD SHAPE...WITH JUST SOME MINOR
ADJUSTMENTS FOR THE REST OF THE OVERNIGHT. INITIAL POCKET OF DRY
AIR LIFTING UP THROUGH EASTERN COUNTIES RIGHT NOW WITH THE MORE
EXPANSIVE DRY SLOT SOUTH OF THE WARM FRONT IN THE LOWER OHIO
VALLEY. HEAVIEST AREA OF RAIN MOVING NORTH OUT OF THE INDY METRO
AREA AND WILL LIFT NORTH OUT OF THE FORECAST AREA BY 06Z. MANY
LOCATIONS ACROSS CENTRAL INDIANA ALREADY AROUND 1.50 INCHES FOR
THE DAY.
WRF AND HRRR BOTH HAVE A NICE HANDLE ON THE RAINFALL COVERAGE
WITH A 3-4 HOUR DRY SLOT EXPANDING ACROSS THE FORECAST AREA FROM
THE BETWEEN 05-10Z AS THE WARM FRONT LIFTS NORTH. WILL KEEP LOWER
POPS DURING THIS TIMEFRAME...THEN RAMP THEM BACK UP TOWARDS
DAYBREAK AS THE CONVECTION OVER SOUTHERN MISSOURI ARRIVES AHEAD OF
THE COLD FRONT. HAVE BACKED OFF ON ISOLATED THUNDER TO LATE
TONIGHT AND EARLY MONDAY MORNING AS THE CONVECTION ALONG THE COLD
FRONT TRACKS THROUGH THE AREA.
TEMPS SHOULD WARM A COUPLE MORE DEGREES OR REMAIN STEADY OVER THE
NEXT SEVERAL HOURS BEFORE BEGINNING TO SLIP BACK TOWARDS DAYBREAK
WITH THE ARRIVAL OF THE COLD FRONT. WINDS WILL BECOME GUSTY
OVERNIGHT AS WELL AS ALREADY SEEING OBS WITH GUSTS PUSHING 30MPH
IN WESTERN KENTUCKY.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
ISSUED AT 307 PM EST SUN NOV 23 2014
FOCUS IS ON WINDY CONDITIONS MONDAY AND ON ANY CHANCES FOR RAIN
THROUGH THE PERIOD. FOR THE MOST PART MODELS ARE CLOSE ENOUGH THAT A
BLEND CAN BE USED...BUT GFS LOOKS TOO FAST WITH WEDNESDAY/S SYSTEM.
RELIED LESS ON GFS THEN.
LOOKS LIKE THERE WILL BE SOME DECENT FORCING WITH THE COLD
FRONT...AND MOST MODELS ARE PUTTING OUT RAINFALL WITH THE FRONT AS
IT PASSES THROUGH. THUS WENT LIKELY POPS MOST AREAS MONDAY MORNING.
AS FRONT PASSES BY FORCING WILL WEAKEN SO LOWERED POPS AFTER IT GOES
BY.
FORCING WITH THE UPPER TROUGH WILL STILL BE CLOSE ENOUGH TO THE AREA
TO GO CHANCE POPS ACROSS THE NORTHWEST FORECAST AREA MONDAY
AFTERNOON AND SLIGHT CHANCE REMAINDER OF NORTH HALF. AS COLDER AIR
MOVES IN DURING THE DAY PRECIPITATION WILL MIX WITH AND CHANGE TO
SNOW. NOT EXPECTING ANY ACCUMULATION AT THIS TIME.
MAIN STORY MONDAY WILL BE THE WINDS. STRONG WINDS WILL BE NOT TOO
FAR OFF THE SURFACE...WITH 850MB WINDS OVER 50KT AND 925MB WINDS
OVER 40KT. SURFACE PRESSURE GRADIENT WILL BE TIGHT ACROSS THE AREA.
THESE PLUS COLD ADVECTION HELPING MIX THE WINDS DOWN WILL CREATE
WINDY CONDITIONS ACROSS THE ENTIRE AREA. SREF FORECASTS SHOW HIGH
CHANCES OF SUSTAINED WINDS OVER 25KT ACROSS PARTS OF THE AREA MONDAY
AS WELL.
STRONGEST WINDS LOOK TO BE ACROSS THE NORTHEAST FORECAST AREA IN THE
TIGHTER PRESSURE GRADIENT WHERE WIND GUSTS AROUND 45 MPH WILL BE
POSSIBLE. ELSEWHERE WINDS COULD GUST AROUND 40 MPH AND WILL BE CLOSE
TO ADVISORY CRITERIA. /GFS SHOWS EVEN HIGHER GUSTS POSSIBLE...WITH
GUSTS MORE WIDESPREAD THAN THE NAM/. AFTER COLLABORATING WITH
SURROUNDING OFFICES DECIDED TO GO WIND ADVISORY ACROSS ALL OF THE
AREA.
FOR MOST AREAS WENT 12Z-00Z...BUT IN THE NORTHEAST WHERE PRESSURE
GRADIENT WILL ARRIVE LATER AND REMAIN A FACTOR LONGER...WENT 14Z-03Z.
UPPER TROUGH COULD STILL BRING A FEW SNOW SHOWERS TO NORTHERN AREAS
MONDAY NIGHT. HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE AREA
TUESDAY INTO WEDNESDAY MORNING.
ANOTHER FRONT WILL BRING CHANCES FOR PRECIPITATION WEDNESDAY
AFTERNOON. UNCERTAINTIES IN TIMING AND FORCING LEADS TO ONLY LOW
POPS FOR NOW. BASED ON EXPECTED TEMPERATURES WENT MIXED RAIN AND
SNOW MOST AREAS.
LOOKING AT TEMPERATURES...ON MONDAY READINGS WILL FALL DURING THE
DAY. A MODEL BLEND LOOKS GOOD FOR LOWS MONDAY NIGHT. MAV MOS LOOKS
TOO WARM ON TUESDAY WITH EXPECTED CLOUD COVER. WENT CLOSER TO A
MODEL BLEND.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 224 PM EST SUN NOV 23 2014
A BROAD UPPER TROUGH MAY BRING MIX PRECIP CHANCES TO THE AREA AT THE
BEGINNING OF THE PERIOD AND THEN ZONAL FLOW WILL COMMENCE THROUGH
THE FIRST HALF OF NEXT WEEKEND. AN UPPER LEVEL DISTURBANCE IS NEXT
DUE TO IMPACT THE REGION SATURDAY NIGHT INTO SUNDAY WITH CHANCES FOR
RAIN/RAIN AND SNOW MIX/AND SNOW. ACCUMULATIONS APPEAR VERY LIGHT AT
THIS TIME AND THIS IS NOT A LOT OF CONFIDENCE THIS FAR OUT IN THE
EXTENDED SO STUCK WITH 20 PERCENT POPS. SUPERBLEND GUIDANCE
INITIALIZED WELL. ONLY NEED TO MAKE A FEW MINOR TWEAKS.
&&
.AVIATION /DISCUSSION FOR THE 24/03Z TAF UPDATE/...
ISSUED AT 927 PM EST SUN NOV 23 2014
NO CHANGES NECESSARY. PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 617 PM EST SUN NOV 23 2014
WIDESPREAD IFR THROUGH THE FIRST 12 TO 14 HOURS OF THE TAF
PERIOD...FOLLOWED BY WIDESPREAD MVFR AND THEN SOME IMPROVEMENT TO
BORDERLINE VFR TOMORROW AFTERNOON.
RAPIDLY STRENGTHENING LOW PRESSURE WILL MOVE THROUGH THE REGION
TONIGHT INTO TOMORROW. WIDESPREAD LIGHT TO MODERATE RAIN AND IFR
RESTRICTIONS NOTED AHEAD OF THE LOW...WHICH SHOULD PERSIST THROUGH
THE NIGHT.
COULD SEE SOME GUSTINESS OVERNIGHT AS THE LOW STRENGTHENS...BUT NOT
CONVINCED IT WILL BE PERSISTENT ENOUGH TO GO WITH MORE THAN A STRONG
SUSTAINED WIND. LOW LEVEL WIND SHEAR IS A MORE POTENT THREAT EAST OF
THE SITES WHERE THE LOW LEVEL JET WILL BE FAR MORE PRONOUNCED...AND
AREA VAD WIND PROFILES SUPPORT WINDS BELOW 2KFT NO MORE THAN 30-35KT
AT THIS TIME.
AS THE COLD FRONT PASSES TOMORROW MORNING AND THE SURFACE PRESSURE
GRADIENT TIGHTENS...LOW LEVEL WINDS WILL STRENGTHEN AND COLD
ADVECTION WILL HELP MIX SOME OF THIS DOWN TO THE SURFACE. WIND GUSTS
FROM THE WEST/SOUTHWEST MAY APPROACH AND EVEN OCCASIONALLY EXCEED
40KT AT THE SITES...ESPECIALLY TOMORROW AFTERNOON.
THUNDER WILL BE AT LEAST A MARGINAL THREAT WITH THE RAPID
DEVELOPMENT OF THE LOW...STRONG DYNAMICS...AND AT LEAST A SMALL
AMOUNT OF SHALLOW INSTABILITY...BUT WITH NO CONFIDENCE IN TIMING OR
PLACEMENT OF THE THREAT...CANNOT INCLUDE A MENTION AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 7 AM TO 7 PM EST MONDAY FOR INZ021-028>030-
035>037-039-043>048-051>057-060>065-067>072.
WIND ADVISORY FROM 9 AM TO 10 PM EST MONDAY FOR INZ031-038-
040>042-049.
&&
$$
SYNOPSIS...50
NEAR TERM...RYAN
SHORT TERM...50
LONG TERM...SMF
AVIATION...NIELD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1235 PM EST SAT NOV 22 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 337 AM EST SAT NOV 22 2014
A SERIES OF DISTURBANCES WILL PASS OVER CENTRAL INDIANA DURING THE
FORECAST PERIOD. THE FIRST SYSTEM AND ITS ASSOCIATED WARM FRONT
WILL IMPACT THE FORECAST AREA THROUGH MONDAY NIGHT WITH MAINLY
RAIN. AFTER A LULL IN ACTIVITY...ANOTHER UPPER LEVEL TROUGH WILL
BRING SNOW SHOWERS FOR WEDNESDAY AND THURSDAY WITH A COLDER AIR
MASS IN PLACE.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 920 AM EST SAT NOV 22 2014
SURFACE ANALYSIS LATE THIS MORNING SHOWS WARMER...SOUTHERLY FLOW
IN PLACE ACROSS INDIANA AS HIGH PRESSURE WAS CENTERED OVER THE
CAROLINAS. ABUNDANT CLOUD COVER WAS STREAMING NORTHEAST FROM THE
SOUTHERN PLAINS AND INTO THE OHIO VALLEY. HRRR CONTINUES TO
SUGGEST SCT LIGHT RAIN SHOWERS CONTINUING THROUGH THE DAY...BUILD
LESSENING IN COVERAGE BY LATE THIS AFTERNOON. UPPER SUPPORT IS
MINIMAL. 290K ISENTROPIC SURFACE CONTINUES TO SHOW BROAD
ISENTROPIC LIFT AMID ONGOING WARM AIR ADVECTION. SPECIFIC
HUMIDITIES CONTINUE TO RUN OVER 6 G/KG. THUS WILL KEEP ONGOING LOW
CHANCES FOR PRECIP THIS AFTERNOON AS COVER LOOKS TO REMAIN
SPOTTY. ONGOING FORECAST HANDLES THIS WELL AND ONLY MINOR CHANGES
HAVE BEEN MADE.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 405 AM EST SAT NOV 22 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD WILL BE THE HIGH PRECIP
CHANCES AS A SURFACE LOW TRAVERSES THE AREA.
PRECIP CHANCES WILL ONLY CONTINUE TO INCREASE TONIGHT THROUGH
TOMORROW AS SURFACE LOW PROVIDES BETTER LIFT. AS A RESULT...WILL
GO WITH POPS OF 100 PERCENT STARTING TOMORROW AFTERNOON THROUGH
TOMORROW NIGHT.
AS SYSTEM MOVES NORTH INTO THE GREAT LAKES REGION ON
MONDAY...PRECIP CHANCES WILL DECREASE FROM WEST TO EAST ACROSS
CENTRAL INDIANA...ALMOST COMPLETELY OUT OF THE AREA BY TUE 00Z. A
FEW LIGHT SNOW SHOWERS CAN BE EXPECTED OVER THE NORTHERN COUNTIES
SINCE COLDER AIR WILL HAVE ALREADY FILTERED IN BY THAT POINT...BUT
NO ACCUMULATIONS ARE EXPECTED SINCE MOST OF THE MOISTURE WILL HAVE
ALREADY EXITED THE AREA.
THE ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE WEEKEND WITH
HIGHS TOPPING OFF IN THE 50S ON SUNDAY. BUT THE COOLING TREND WILL
COMMENCE ON MONDAY AS HIGHS ONLY TOP OFF IN THE 40S OVER THE WESTERN
TIER OF COUNTIES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 337 AM EST SAT NOV 22 2014
MODELS INDICATE A BROAD UPPER TROUGH WILL BE ACROSS CENTRAL AND
EASTERN CANADA AS WELL AS THE UPPER MIDWEST AND GREAT LAKES. A
SURFACE LOW OVER SOUTHEAST CANADA TUESDAY WILL MOVE ON TO THE EAST
AND HIGH PRESSURE WILL MOVE EAST ACROSS OUR REGION TUESDAY NIGHT AND
EARLY WEDNESDAY. ANOTHER AREA OF LOW PRESSURE WILL AFFECT OUR
WEATHER AS IT MOVES EAST ACROSS THE NORTHERN PORTIONS OF ILLINOIS
AND INDIANA WEDNESDAY NIGHT AND THURSDAY. WILL MENTION A SLIGHT
CHANCE OF SNOW NORTHWEST LATE WEDNESDAY AND A CHANCE OF SNOW NORTH
AND CENTRAL AND A SLIGHT CHANCE OF SNOW OR MIXED PRECIPITATION FAR
SOUTH. DRY WEATHER WILL RETURN FRIDAY AS HIGH PRESSURE OVER THE
UPPER MIDWEST BUILDS OUR WAY.
IN REGARDS TO TEMPERATURES...MODELS HAVE TRENDED A LITTLE WARMER
LATE WEDNESDAY AND THURSDAY. HOWEVER THE GFS IS OVERDOING THIS AS
IT KEEPS THE ARCTIC AIR BOTTLED ACROSS SOUTHERN CANADA AND GREAT
LAKES. THE 00Z EURO AND GEMNH MODELS PULL MORE OF THIS COLD AIR
SOUTH INTO OUR ALL REGION ESPECIALLY THURSDAY. WITH THE GFS BEING SO
WARM...CUT MOS BLEND TEMPERATURES A LITTLE AROUND THURSDAY.
OTHERWISE...ONLY MINOR TWEAKS MADE TO TEMPERATURES IN MOST OTHER
PERIODS.
&&
.AVIATION /DISCUSSION FOR 221800Z TAF ISSUANCE/...
ISSUED AT 1234 PM EST SAT NOV 22 2014
VFR CONDITIONS WITH SCATTERED VERY LIGHT SHOWERS AND LOW LEVEL WIND
SHEAR SHOULD CONTINUE THROUGH THE AFTERNOON. LOW LEVEL JET SHOULD
WEAKEN SOME LATER THIS AFTERNOON ENOUGH TO DROP MENTION OF LLWS BY
AROUND 23Z. TIME HEIGHTS SHOW LOW LEVEL MOISTURE INCREASING DURING
THE OVERNIGHT AND EXPECT TO SEE MVFR CLOUD DECK DEVELOP BETWEEN
AROUND 9-12Z AND MORE RAIN TO DEVELOP AFTER THAT. RIGHT NOW WILL GO
WITH LOW END MVFR BUT WILL NEED TO WATCH FOR LOWER CEILINGS AS
SYSTEM APPROACHES.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...PUMA
SHORT TERM...TDUD
LONG TERM....JH
AVIATION...CP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
926 AM EST SAT NOV 22 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 337 AM EST SAT NOV 22 2014
A SERIES OF DISTURBANCES WILL PASS OVER CENTRAL INDIANA DURING THE
FORECAST PERIOD. THE FIRST SYSTEM AND ITS ASSOCIATED WARM FRONT
WILL IMPACT THE FORECAST AREA THROUGH MONDAY NIGHT WITH MAINLY
RAIN. AFTER A LULL IN ACTIVITY...ANOTHER UPPER LEVEL TROUGH WILL
BRING SNOW SHOWERS FOR WEDNESDAY AND THURSDAY WITH A COLDER AIR
MASS IN PLACE.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 920 AM EST SAT NOV 22 2014
SURFACE ANALYSIS LATE THIS MORNING SHOWS WARMER...SOUTHERLY FLOW
IN PLACE ACROSS INDIANA AS HIGH PRESSURE WAS CENTERED OVER THE
CAROLINAS. ABUNDANT CLOUD COVER WAS STREAMING NORTHEAST FROM THE
SOUTHERN PLAINS AND INTO THE OHIO VALLEY. HRRR CONTINUES TO
SUGGEST SCT LIGHT RAIN SHOWERS CONTINUING THROUGH THE DAY...BUILD
LESSENING IN COVERAGE BY LATE THIS AFTERNOON. UPPER SUPPORT IS
MINIMAL. 290K ISENTROPIC SURFACE CONTINUES TO SHOW BROAD
ISENTROPIC LIFT AMID ONGOING WARM AIR ADVECTION. SPECIFIC
HUMIDITIES CONTINUE TO RUN OVER 6 G/KG. THUS WILL KEEP ONGOING LOW
CHANCES FOR PRECIP THIS AFTERNOON AS COVER LOOKS TO REMAIN
SPOTTY. ONGOING FORECAST HANDLES THIS WELL AND ONLY MINOR CHANGES
HAVE BEEN MADE.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 405 AM EST SAT NOV 22 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD WILL BE THE HIGH PRECIP
CHANCES AS A SURFACE LOW TRAVERSES THE AREA.
PRECIP CHANCES WILL ONLY CONTINUE TO INCREASE TONIGHT THROUGH
TOMORROW AS SURFACE LOW PROVIDES BETTER LIFT. AS A RESULT...WILL
GO WITH POPS OF 100 PERCENT STARTING TOMORROW AFTERNOON THROUGH
TOMORROW NIGHT.
AS SYSTEM MOVES NORTH INTO THE GREAT LAKES REGION ON
MONDAY...PRECIP CHANCES WILL DECREASE FROM WEST TO EAST ACROSS
CENTRAL INDIANA...ALMOST COMPLETELY OUT OF THE AREA BY TUE 00Z. A
FEW LIGHT SNOW SHOWERS CAN BE EXPECTED OVER THE NORTHERN COUNTIES
SINCE COLDER AIR WILL HAVE ALREADY FILTERED IN BY THAT POINT...BUT
NO ACCUMULATIONS ARE EXPECTED SINCE MOST OF THE MOISTURE WILL HAVE
ALREADY EXITED THE AREA.
THE ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE WEEKEND WITH
HIGHS TOPPING OFF IN THE 50S ON SUNDAY. BUT THE COOLING TREND WILL
COMMENCE ON MONDAY AS HIGHS ONLY TOP OFF IN THE 40S OVER THE WESTERN
TIER OF COUNTIES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 337 AM EST SAT NOV 22 2014
MODELS INDICATE A BROAD UPPER TROUGH WILL BE ACROSS CENTRAL AND
EASTERN CANADA AS WELL AS THE UPPER MIDWEST AND GREAT LAKES. A
SURFACE LOW OVER SOUTHEAST CANADA TUESDAY WILL MOVE ON TO THE EAST
AND HIGH PRESSURE WILL MOVE EAST ACROSS OUR REGION TUESDAY NIGHT AND
EARLY WEDNESDAY. ANOTHER AREA OF LOW PRESSURE WILL AFFECT OUR
WEATHER AS IT MOVES EAST ACROSS THE NORTHERN PORTIONS OF ILLINOIS
AND INDIANA WEDNESDAY NIGHT AND THURSDAY. WILL MENTION A SLIGHT
CHANCE OF SNOW NORTHWEST LATE WEDNESDAY AND A CHANCE OF SNOW NORTH
AND CENTRAL AND A SLIGHT CHANCE OF SNOW OR MIXED PRECIPITATION FAR
SOUTH. DRY WEATHER WILL RETURN FRIDAY AS HIGH PRESSURE OVER THE
UPPER MIDWEST BUILDS OUR WAY.
IN REGARDS TO TEMPERATURES...MODELS HAVE TRENDED A LITTLE WARMER
LATE WEDNESDAY AND THURSDAY. HOWEVER THE GFS IS OVERDOING THIS AS
IT KEEPS THE ARCTIC AIR BOTTLED ACROSS SOUTHERN CANADA AND GREAT
LAKES. THE 00Z EURO AND GEMNH MODELS PULL MORE OF THIS COLD AIR
SOUTH INTO OUR ALL REGION ESPECIALLY THURSDAY. WITH THE GFS BEING SO
WARM...CUT MOS BLEND TEMPERATURES A LITTLE AROUND THURSDAY.
OTHERWISE...ONLY MINOR TWEAKS MADE TO TEMPERATURES IN MOST OTHER
PERIODS.
&&
.AVIATION /DISCUSSION FOR THE 22/15 TAF ISSUANCE/...
ISSUED AT 910 AM EST SAT NOV 22 2014
TWEAKED CURRENT CONDITIONS ONLY. PREVIOUS DISCUSSION FOLLOWS...
MOSTLY VFR CEILINGS WITH SCATTERED LIGHT SHOWERS WILL BE THE RULE.
HIGH PRESSURE OFF THE MID ATLANTIC COAST AND LOW PRESSURE MOVING
EAST ACROSS THE NORTHERN PLAINS WILL PRODUCE A BRISK SOUTHERLY FLOW.
TIME HEIGHT CHARTS INDICATE PLENTY OF LOW LEVEL MOISTURE. HOWEVER
CEILINGS UPSTREAM ARE MOSTLY ABOVE 3 THOUSAND FEET AND CEILINGS
AROUND 4 THOUSAND FEET SHOULD BE THE RULE UNTIL SUNDAY MORNING WITH
MVFR CEILINGS BEING THE RULE SUNDAY MORNING ON.
SCATTERED LIGHT SHOWERS WILL BE THE RULE THROUGH THE PERIODS AS GULF
MOISTURE CONTINUES TO FEED NORTH INTO OUR REGION.
A STRONG LOW LEVEL JET OF 50KT WORKING ACROSS THE AREA WILL RESULT
IN SOME LLWS WHICH HAS BEEN INCLUDED. THIS LOW LEVEL JET SHOULD
WEAKEN SOME BY LATE AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...PUMA
SHORT TERM...TDUD
LONG TERM....JH
AVIATION...JH/CP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1205 AM EST SAT NOV 22 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 332 PM EST FRI NOV 21 2014
HIGH PRESSURE WILL PUSH OFF TO THE EAST AS A WARM FRONT AND A STRONG
LOW PRESSURE SYSTEM ENTER FROM THE SOUTHWEST TONIGHT. THIS SYSTEM
WILL KEEP PRECIPITATION IN THE FORECAST THROUGH THE WEEKEND. IN ITS
WAKE...COLDER AND DRIER WEATHER WILL RETURN...THEN A UPPER LEVEL
SYSTEM WILL BRING CHANCES FOR SNOW TO THE AREA NEXT WEDNESDAY
THROUGH THURSDAY.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 953 PM EST FRI NOV 21 2014
PRECIP CONTINUES TO BE SLOW TO MOVE INTO THE AREA AND IS SPOTTY AT
BEST FOR THE MOMENT. HRRR DOES INDICATE AN EXPANSION IN COVERAGE
OVER THE NEXT SEVERAL HOURS BUT CONCURRENTLY BRINGS TEMPERATURES UP
AS IT MOVES THE PRECIP IN. HAVE ADJUSTED MIN TEMPS AND HOURLY TEMPS
AS THE WARM ADVECTION CONTINUES...MANY SITES IN THE SOUTHWEST HAVE
LIKELY ALREADY HIT THEIR MINS FOR THE NIGHT.
WILL CONTINUE TO CARRY FREEZING RAIN IN THE GRIDS WHERE THE HOURLY
TEMPS ARE AT OR BELOW 32 WITH A SMALL MARGIN OF RAIN OR FREEZING
RAIN OWING TO UNCERTAINTY...BUT THIS WILL RESULT IN A VERY SHORT
WINDOW OF ICING THREAT AT ANY ONE LOCATION...LIKELY 2-3 HOURS AT
MOST...MAYBE 4 HOURS IN THE NORTH OR NORTHEAST WHICH HAS A BIT
FURTHER TO GO TO THE FREEZING MARK.
PREVIOUS DISCUSSIONS FOLLOW.
ISSUED AT 657 PM EST FRI NOV 21 2014
WITH REGIONAL RADAR TRENDS VERY SLOW TO SHOW ANY ECHOES AT
ALL AND DEWPOINTS REMAINING VERY DRY ACROSS THE AREA...HAVE PUSHED
BACK POPS AT LEAST A FEW HOURS WITH THIS UPDATE...AND MAY NEED TO
PUSH THEM BACK EVEN MORE DEPENDING ON HOW THINGS EVOLVE OVER THE
NEXT FEW HOURS. HRRR DOES HAVE SOME PRECIP IN THE FAR SOUTHWEST BY
04Z. IT IS A RACE BETWEEN WARM ADVECTION AND PRECIP ONSET AT THIS
POINT TO DETERMINE WHETHER ANY FREEZING PRECIP WILL FALL. PREVIOUS
DISCUSSION FOLLOWS.
ISSUED AT 332 PM EST FRI NOV 21 2014
FOR THE REST OF THIS AFTERNOON AND EARLY EVENING EXPECT INCREASING
CLOUD COVER FROM SOUTHWEST TO NORTHEAST AS A FRONTAL SYSTEM DRAPED
MOVES CLOSER TO THE FORECAST AREA. MODELS ARE TIMING THE MOISTURE
FROM THIS SYSTEM TO ARRIVE EVEN SLOWER THAN EXPECTED WHICH WILL
IMPACT PRECIP TYPE OVERNIGHT WHERE ONCE WIDESPREAD FREEZING RAIN WAS
EXPECTED. THIS PERIOD OF LIGHT FREEZING RAIN LOOKS LIKE A MUCH
SMALLER WINDOW FOR CENTRAL INDIANA AS WARM AIR ADVECTION REALLY
KICKS IN LATER THIS EVENING AND SURFACE TEMPERATURES BEGIN TO RISE
TO ABOVE FREEZING. THIS COMBINED WITH THE MUCH SLOWER ONSET OF
PRECIP. THE MAIN WINDOW FOR -FZRA RAIN IS 9PM THROUGH 5AM...QUICKLY
CHANGING OVER TO RAIN FROM SW TO NE AS THE WARMER AIR ARRIVES. QPF
AMOUNTS STILL LOOK EXTREMELY LOW...ONLY A FEW HUNDREDTHS OF AN INCH.
OPTED NOT TO ISSUE ANY STATEMENTS NOR HEADLINES FOR THE -FZRA RAIN
BASED ON THIS LATEST GUIDANCE AND WILL CONTINUE TO MONITOR
CONDITIONS UPSTREAM TO SEE IF A SPECIAL WEATHER STATEMENT IS NEEDED.
IN COORDINATION WITH SURROUNDING OFFICES WILL CONTINUE TO MENTION
THE LIGHT FREEZING RAIN AND POTENTIALLY SLICK/ICY ROADS FOR A BRIEF
PERIOD OVERNIGHT IN THE HWO AND WX STORY.
LOW TEMPS WILL OCCUR EARLY THIS EVENING (RANGING FROM MID 20S TO MID
30S) AND QUICKLY INCREASE TO MID 30S TO LOW 40S BY 12Z SAT!
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 332 PM EST FRI NOV 21 2014
BY 10-12Z SATURDAY MORNING ALL THE POTENTIAL -FZRA WILL HAVE CHANGED
OVER TO RAIN. AND WARM AIR ADVECTION WILL CONTINUE TO FILTER INTO
THE AREA IN EARNEST THROUGH SATURDAY WITH HIGH TEMPERATURES COMING
IN EVEN WARMER THIS MODEL RUN WITH HIGHS RANGING FROM MID 40S
(NORTH) TO NEARLY THE MID 50S (FAR SOUTH COUNTIES) BY SAT 12Z
THE SURFACE LOW WILL CONTINUE ITS TRACK ACROSS THE MISSISSIPPI
VALLEY ON SATURDAY INTO SATURDAY NIGHT AND THERE CONTINUES TO LOOKS
LIKE A LULL DURING A GOOD PORTION OF THE DAY SATURDAY...SO BACK OFF
ON POPS OVER THE ENTIRE AREA. THE HIGHEST CHANCES FOR RAIN WILL BE
ON SUNDAY AS BEST LIFT FROM WARM FRONT AND LOW PRESSURE MOVES ACROSS
THE AREA. WILL CONTINUE WITH 100 PERCENT POPS...ESPECIALLY FOR THE
SECOND HALF OF SUNDAY.
IN TERMS OF TEMPS...AS MENTIONED ABOVE EXPECT HIGHS TO CLIMB INTO
THE 50S WITH DECENT WARM ADVECTION...AND LOWS TO BE IN THE 40S.
RAIN WILL SLOWLY BEGIN TO TAPER OFF ON MONDAY AS THE SYSTEM SLOWLY
MOST OFF TO THE EAST. COLD AIR WILL THEN MOVE BACK IN MONDAY
NIGHT IN THE WAKE OF THE FRONTAL PASSAGE. COULD SEE A FEW SNOW
SHOWERS IN THE NORTH AS WEAK WAVE MOVES THROUGH. FOR NOW INDICATED
A MIX OF -RA/SN LATE MONDAY AFTERNOON AND SLIGHT CHANCES FOR SNOW
SHOWERS OR FLURRIES ACROSS THE FAR NORTHERN TIER OF COUNTIES
MONDAY NIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 255 PM EST FRI NOV 21 2014
COLD AIR WILL MOVE BACK IN MONDAY NIGHT IN THE WAKE OF THE FRONTAL
PASSAGE. COULD SEE A FEW SNOW SHOWERS IN THE NORTH AS WEAK WAVE
MOVES THROUGH. KEPT CHANCE FOR FLURRIES GOING TUESDAY IN THE
NORTHERN HALF OR SO AS WELL WITH CYCLONIC UPPER FLOW. WEDNESDAY ON
MODELS ARE SHOWING SOME DECENT DIFFERENCES IN THE UPPER PATTERN AND
ENSEMBLES ARE PRETTY VARIABLE SO WILL JUST GO WITH INITIALIZATION.
TEMPERATURES DO SEEM TO BE COMING TOGETHER A LITTLE COOLER FOR THAT
TIME SO STUCK WITH SMALL CHANCES FOR SNOW FOR PRECIP TYPE. THERE IS
SOME HINT OF A WARMUP OUT BEYOND FRIDAY BUT THAT REMAINS TO BE SEEN.
&&
.AVIATION /DISCUSSION FOR THE 22/06Z TAFS/...
ISSUED AT 1205 AM EST SAT NOV 22 2014
VFR EXPECTED INITIALLY. A BRIEF PERIOD OF MVFR WILL BE
POSSIBLE FROM 08Z-12Z...BEFORE VFR CONDITIONS RETURN.
LIGHT FREEZING RAIN WILL BE POSSIBLE OVERNIGHT AT LAF.
ELSEWHERE...TEMPERATURES SHOULD WARM TO NEAR OR ABOVE FREEZING NEAR
PRECIP ONSET...SO ANY FREEZING PRECIP WILL LIKELY BE VERY BRIEF.
TIME HEIGHTS THEN CONTINUE TO SHOW PLENTIFUL LOWER LEVEL MOISTURE
THROUGH THE FORECAST PERIOD AMID WARM AIR ADVECTION WITHIN THE
COLUMN. THUS A RETURN TO VFR WILL BE EXPECTED AFT 12Z WITH SCT
SHOWERS IN THE AREA. A STRONG LLJ OF 50KT WORKING ACROSS THE AREA
MAY RESULT IN SOME LLWS WHICH HAS BEEN INCLUDED.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...CP
AVIATION...JP/NIELD/JH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1050 PM MST FRI NOV 21 2014
.UPDATE...
ISSUED AT 1050 PM MST FRI NOV 21 2014
REPORTS OF DENSE FOG WITH LOW VISIBILITY IN EASTERN ZONES HAS
PROMPTED ISSUANCE OF DENSE FOG ADVISORY FROM NOW INTO SATURDAY
MORNING AROUND 900 AM CST. NO OTHER CHANGES MADE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 138 PM MST FRI NOV 21 2014
MAIN CONCERNS ARE EXTENT OF FOG TONIGHT FOLLOWED BY HOW MUCH TO
WARM UP THE TEMPERATURES ON SATURDAY. LARGE AREA OF STRATUS AND
SOME FOG TO OUR SOUTH AND SOUTHEAST AT THIS TIME. RETURN FLOW WILL
BE IN PLACE BY THE TIME SUN GOES DOWN AND THE LOW LEVEL INVERSION
STRENGTHENS. SO WOULD EXPECT THIS MOISTURE TO BE ABLE TO RETURN
NORTH AND MOVE INTO THE AREA BEFORE THE WINDS SHIFT TO A WEST TO
SOUTHWEST DIRECTION BY LATER TONIGHT AS A SURFACE TROUGH MOVES
THROUGH.
HRRR FOLLOWED BY RAP HAVE BEEN DOING VERY WELL IN THE DEPICTION OF
THIS LOW LEVEL MOISTURE FIELD. BASED ON THAT AND THE OBSERVATIONS
TO OUR SOUTH...WENT AHEAD AND FOLLOWED THE HRRR/RAP VERY CLOSELY
FOR THE CLOUD COVER AND FOG FOR TONIGHT. FOG/LOW CLOUDS SHOULD
STAY IN THE EASTERN HALF TO TWO THIRDS OF THE AREA. IF HRRR ENDS
UP BEING RIGHT THERE COULD BE SOME DENSE FOG POSSIBLE IN THE FAR
EASTERN PORTION.
FOG AND STRATUS DECREASE LATE TONIGHT AND EARLY TOMORROW AS
SURFACE TROUGH MOVES THROUGH AND SHIFTS/INCREASES THE WINDS FROM
THE WEST. AT THIS TIME THE FOG SHOULD END BY MID MORNING. ONCE THE
FOG/CLOUDS CLEAR OFF THERE WILL BE PLENTIFUL SUNSHINE AND
DOWNSLOPE WINDS THROUGH 700 MB. COMBINATION OF DRY AIR MASS AND
GROUND COMBINED WITH THE ABUNDANT SUNSHINE AND DOWNSLOPE WINDS
WILL ALLOW FOR A GOOD WARMUP.
QUESTION IS HOW MUCH. THE NWP AND ESPECIALLY THE 2 METER GUIDANCE
HAS BEEN RUNNING COOL DURING THE LAST WEEK. AT THIS TIME WENT
ABOVE GUIDANCE IN MOST PLACES WITH 60S...MOSTLY MIDDLE AND UPPER
60S....ACROSS THE ENTIRE AREA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 210 PM MST FRI NOV 21 2014
FOR THE EXTENDED FORECAST PERIOD...VARIABLE WEATHER CONDITIONS ARE
EXPECTED THROUGHOUT DUE TO PASSING COLD FRONTS UNDER A NORTHWEST
FLOW REGIME. OVERALL...THE PATTERN REMAINS FAIRLY CONSISTENT WITH
LITTLE CHANCE OF MAJOR PRECIPITATION-PRODUCING SYSTEMS REACHING THE
REGION. PRIMARY CHANGE TO THIS EXTENDED PACKAGE WAS TO REMOVE
PRECIPITATION CHANCES FOR THANKSGIVING. MORE DETAILS ON THIS BELOW.
FOR SATURDAY NIGHT INTO SUNDAY MORNING...A STRONG COLD FRONT PASSAGE
IS ANTICIPATED. TEMPERATURES WILL BE SLOW TO FALL SATURDAY NIGHT DUE
TO INCREASING CLOUD COVER. THEN...A QUICK DROP IN TEMPERATURES AND
GUSTY NORTH WINDS ARE LIKELY IMMEDIATELY BEHIND THE FRONT. AS THE
FRONT PASSES THROUGH...THE ATMOSPHERE MOISTENS AT LOW LEVELS WHEN
THE COOLER AIR INTRUDES. THERE SHOULD BE ENOUGH MID-LEVEL LIFT AND
MOISTURE FOR RAIN/SNOW SHOWERS DEVELOPMENT BUT THE QUESTION OVER THE
PAST FEW FORECAST RUNS HAS BEEN WHETHER OR NOT THIS PRECIPITATION
REACHES THE GROUND. BASED ON LATEST GUIDANCE...THERE SHOULD BE A
SMALL WINDOW OF OPPORTUNITY FOR MEASURABLE PRECIPITATION TO REACH
THE GROUND AHEAD OF INCOMING POST-FRONTAL DRY AIR. THEREFORE...
PLACED A SLIGHT CHANCE FOR MEASURABLE PRECIPITATION INTO THE
FORECAST AND MAINTAINED SPRINKLES/FLURRIES MENTION SURROUNDING THE
SLIGHT CHANCE POPS.
MAIN STORY FOR THE REST OF SUNDAY THROUGH MONDAY SHOULD BE
BREEZY/WINDY CONDITIONS AND COOL TEMPERATURES. WITH PERSISTENT COLD
AIR ADVECTION AND POSSIBLE CLOUD COVER OVERHEAD...HAVE A HARD TIME
BELIEVING THAT THE REGION WILL BE ABLE TO REACH MEX/MET/ECE GUIDANCE
TEMPERATURES. WENT BELOW GUIDANCE FOR HIGH TEMPERATURES DUE TO THIS
THINKING. REGARDING THE WINDS...MODELS ARE NOT IN STRONG AGREEMENT
WITH RESPECT TO HOW STRONG THE WINDS WILL BE AND WHEN THE STRONGEST
WINDS WILL OCCUR. ANY POSSIBLE CLOUD COVER ALSO MESSES WITH
ANTICIPATED MIXING HEIGHTS SO HARD TO TELL HOW STRONG THE MIXED DOWN
GUSTS WILL BE AT THIS TIME. WITHOUT A STRONG CUT-OFF LOW PRESSURE
SYSTEM PRESENT...CURRENTLY DO NOT BELIEVE THAT THIS WILL BE A MAJOR
WIND EVENT. TYPICAL COLD/WINDY HIGH PLAINS DAYS ARE FORECAST WITH
NORTH WINDS 20-30 MPH...GUSTING TO 45 MPH AND HIGH TEMPERATURES IN
THE LOW TO UPPER 40S.
BEYOND MONDAY...A WEAK UPPER LEVEL DISTURBANCE MOVES THROUGH THE
HIGH PLAINS TUESDAY INTO TUESDAY NIGHT. THE CR INITIALIZATION
PROCEDURE DID NOT INCLUDE POPS AND WITH A DRY LAYER OF AIR AT THE
SURFACE...THOUGHT THIS WAS APPROPRIATE. POPS MAY NEED TO BE INCLUDED
AT A LATER TIME BUT MODEL CONSISTENCY WAS NOT STRONG ENOUGH FOR
INCLUSION WITH THIS RUN.
ANOTHER STRONG UPPER LEVEL DISTURBANCE SWINGS SOUTH OVER THE PLAINS
AND INTO THE MID-MISSISSIPPI VALLEY BY THURSDAY. THIS SYSTEM SHOULD
FORCE A BACKDOOR COLD FRONT INTO THE HIGH PLAINS. IT IS HARD TO TELL
HOW FAR SOUTHWEST THIS FRONT WILL REACH AND THERE IS A STRONG CHANCE
FOR A LARGE TEMPERATURE GRADIENT ACROSS THE REGION. CURRENT
THANKSGIVING FORECAST CALLS FOR A HIGH OF 38 DEGREES AT MCCOOK
NEBRASKA...44 AT GOODLAND KANSAS AND 52 AT KIT CARSON COLORADO.
MODELS TRENDED PRECIPITATION CHANCES FOR THANKSGIVING DOWN AND
BELIEVE THIS IS ACCURATE CONSIDERING A RIDGE OF HIGH PRESSURE WILL
BUILD IN FROM THE WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1024 PM MST FRI NOV 21 2014
FOR KGLD...VFR CONDITIONS WITH MIX OF SKC AND SCT-BKN150 AFT 12Z
SATURDAY. WINDS WSW AROUND 10KTS.
FOR KMCK...MAINLY VFR CONDITIONS WITH MIX OF SKC AND SCT-BKN150
AFT 14Z SATURDAY. MVFR FOG POSSIBLE DOWN TO 4SM AT TIMES FROM
08Z-12Z SATURDAY. WINDS WSW AROUND 10KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...DENSE FOG ADVISORY UNTIL 9 AM CST SATURDAY FOR KSZ002>004-
014>016-028-029.
CO...NONE.
NE...DENSE FOG ADVISORY UNTIL 9 AM CST SATURDAY FOR NEZ080-081.
&&
$$
UPDATE...JN
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1024 PM MST FRI NOV 21 2014
.UPDATE...
ISSUED AT 926 PM MST FRI NOV 21 2014
UPDATE TO ZONES SENT OUT TO ACCOMMODATE LATEST TEMP TRENDS FROM
AREA OBS. LOW LEVEL CLOUDS COVER STILL LINGERING OVER EASTERN
EDGES OF THE FORECAST AREA AND SHOULD CONTINUE TREK EASTWARD
OVERNIGHT. THIS WILL GIVE WAY TO MID LEVEL CLOUDS WHICH ARE
CURRENTLY CENTRAL/WESTERN AREAS. LATEST EASTERN ZONES OBS ARE
STARTING TO SHOW FOG DEVELOPING...SO HAVE LEFT THAT IN OVERNIGHT.
REST OF FORECAST ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 138 PM MST FRI NOV 21 2014
MAIN CONCERNS ARE EXTENT OF FOG TONIGHT FOLLOWED BY HOW MUCH TO
WARM UP THE TEMPERATURES ON SATURDAY. LARGE AREA OF STRATUS AND
SOME FOG TO OUR SOUTH AND SOUTHEAST AT THIS TIME. RETURN FLOW WILL
BE IN PLACE BY THE TIME SUN GOES DOWN AND THE LOW LEVEL INVERSION
STRENGTHENS. SO WOULD EXPECT THIS MOISTURE TO BE ABLE TO RETURN
NORTH AND MOVE INTO THE AREA BEFORE THE WINDS SHIFT TO A WEST TO
SOUTHWEST DIRECTION BY LATER TONIGHT AS A SURFACE TROUGH MOVES
THROUGH.
HRRR FOLLOWED BY RAP HAVE BEEN DOING VERY WELL IN THE DEPICTION OF
THIS LOW LEVEL MOISTURE FIELD. BASED ON THAT AND THE OBSERVATIONS
TO OUR SOUTH...WENT AHEAD AND FOLLOWED THE HRRR/RAP VERY CLOSELY
FOR THE CLOUD COVER AND FOG FOR TONIGHT. FOG/LOW CLOUDS SHOULD
STAY IN THE EASTERN HALF TO TWO THIRDS OF THE AREA. IF HRRR ENDS
UP BEING RIGHT THERE COULD BE SOME DENSE FOG POSSIBLE IN THE FAR
EASTERN PORTION.
FOG AND STRATUS DECREASE LATE TONIGHT AND EARLY TOMORROW AS
SURFACE TROUGH MOVES THROUGH AND SHIFTS/INCREASES THE WINDS FROM
THE WEST. AT THIS TIME THE FOG SHOULD END BY MID MORNING. ONCE THE
FOG/CLOUDS CLEAR OFF THERE WILL BE PLENTIFUL SUNSHINE AND
DOWNSLOPE WINDS THROUGH 700 MB. COMBINATION OF DRY AIR MASS AND
GROUND COMBINED WITH THE ABUNDANT SUNSHINE AND DOWNSLOPE WINDS
WILL ALLOW FOR A GOOD WARMUP.
QUESTION IS HOW MUCH. THE NWP AND ESPECIALLY THE 2 METER GUIDANCE
HAS BEEN RUNNING COOL DURING THE LAST WEEK. AT THIS TIME WENT
ABOVE GUIDANCE IN MOST PLACES WITH 60S...MOSTLY MIDDLE AND UPPER
60S....ACROSS THE ENTIRE AREA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 210 PM MST FRI NOV 21 2014
FOR THE EXTENDED FORECAST PERIOD...VARIABLE WEATHER CONDITIONS ARE
EXPECTED THROUGHOUT DUE TO PASSING COLD FRONTS UNDER A NORTHWEST
FLOW REGIME. OVERALL...THE PATTERN REMAINS FAIRLY CONSISTENT WITH
LITTLE CHANCE OF MAJOR PRECIPITATION-PRODUCING SYSTEMS REACHING THE
REGION. PRIMARY CHANGE TO THIS EXTENDED PACKAGE WAS TO REMOVE
PRECIPITATION CHANCES FOR THANKSGIVING. MORE DETAILS ON THIS BELOW.
FOR SATURDAY NIGHT INTO SUNDAY MORNING...A STRONG COLD FRONT PASSAGE
IS ANTICIPATED. TEMPERATURES WILL BE SLOW TO FALL SATURDAY NIGHT DUE
TO INCREASING CLOUD COVER. THEN...A QUICK DROP IN TEMPERATURES AND
GUSTY NORTH WINDS ARE LIKELY IMMEDIATELY BEHIND THE FRONT. AS THE
FRONT PASSES THROUGH...THE ATMOSPHERE MOISTENS AT LOW LEVELS WHEN
THE COOLER AIR INTRUDES. THERE SHOULD BE ENOUGH MID-LEVEL LIFT AND
MOISTURE FOR RAIN/SNOW SHOWERS DEVELOPMENT BUT THE QUESTION OVER THE
PAST FEW FORECAST RUNS HAS BEEN WHETHER OR NOT THIS PRECIPITATION
REACHES THE GROUND. BASED ON LATEST GUIDANCE...THERE SHOULD BE A
SMALL WINDOW OF OPPORTUNITY FOR MEASURABLE PRECIPITATION TO REACH
THE GROUND AHEAD OF INCOMING POST-FRONTAL DRY AIR. THEREFORE...
PLACED A SLIGHT CHANCE FOR MEASURABLE PRECIPITATION INTO THE
FORECAST AND MAINTAINED SPRINKLES/FLURRIES MENTION SURROUNDING THE
SLIGHT CHANCE POPS.
MAIN STORY FOR THE REST OF SUNDAY THROUGH MONDAY SHOULD BE
BREEZY/WINDY CONDITIONS AND COOL TEMPERATURES. WITH PERSISTENT COLD
AIR ADVECTION AND POSSIBLE CLOUD COVER OVERHEAD...HAVE A HARD TIME
BELIEVING THAT THE REGION WILL BE ABLE TO REACH MEX/MET/ECE GUIDANCE
TEMPERATURES. WENT BELOW GUIDANCE FOR HIGH TEMPERATURES DUE TO THIS
THINKING. REGARDING THE WINDS...MODELS ARE NOT IN STRONG AGREEMENT
WITH RESPECT TO HOW STRONG THE WINDS WILL BE AND WHEN THE STRONGEST
WINDS WILL OCCUR. ANY POSSIBLE CLOUD COVER ALSO MESSES WITH
ANTICIPATED MIXING HEIGHTS SO HARD TO TELL HOW STRONG THE MIXED DOWN
GUSTS WILL BE AT THIS TIME. WITHOUT A STRONG CUT-OFF LOW PRESSURE
SYSTEM PRESENT...CURRENTLY DO NOT BELIEVE THAT THIS WILL BE A MAJOR
WIND EVENT. TYPICAL COLD/WINDY HIGH PLAINS DAYS ARE FORECAST WITH
NORTH WINDS 20-30 MPH...GUSTING TO 45 MPH AND HIGH TEMPERATURES IN
THE LOW TO UPPER 40S.
BEYOND MONDAY...A WEAK UPPER LEVEL DISTURBANCE MOVES THROUGH THE
HIGH PLAINS TUESDAY INTO TUESDAY NIGHT. THE CR INITIALIZATION
PROCEDURE DID NOT INCLUDE POPS AND WITH A DRY LAYER OF AIR AT THE
SURFACE...THOUGHT THIS WAS APPROPRIATE. POPS MAY NEED TO BE INCLUDED
AT A LATER TIME BUT MODEL CONSISTENCY WAS NOT STRONG ENOUGH FOR
INCLUSION WITH THIS RUN.
ANOTHER STRONG UPPER LEVEL DISTURBANCE SWINGS SOUTH OVER THE PLAINS
AND INTO THE MID-MISSISSIPPI VALLEY BY THURSDAY. THIS SYSTEM SHOULD
FORCE A BACKDOOR COLD FRONT INTO THE HIGH PLAINS. IT IS HARD TO TELL
HOW FAR SOUTHWEST THIS FRONT WILL REACH AND THERE IS A STRONG CHANCE
FOR A LARGE TEMPERATURE GRADIENT ACROSS THE REGION. CURRENT
THANKSGIVING FORECAST CALLS FOR A HIGH OF 38 DEGREES AT MCCOOK
NEBRASKA...44 AT GOODLAND KANSAS AND 52 AT KIT CARSON COLORADO.
MODELS TRENDED PRECIPITATION CHANCES FOR THANKSGIVING DOWN AND
BELIEVE THIS IS ACCURATE CONSIDERING A RIDGE OF HIGH PRESSURE WILL
BUILD IN FROM THE WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1024 PM MST FRI NOV 21 2014
FOR KGLD...VFR CONDITIONS WITH MIX OF SKC AND SCT-BKN150 AFT 12Z
SATURDAY. WINDS WSW AROUND 10KTS.
FOR KMCK...MAINLY VFR CONDITIONS WITH MIX OF SKC AND SCT-BKN150
AFT 14Z SATURDAY. MVFR FOG POSSIBLE DOWN TO 4SM AT TIMES FROM
08Z-12Z SATURDAY. WINDS WSW AROUND 10KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
926 PM MST FRI NOV 21 2014
.UPDATE...
ISSUED AT 926 PM MST FRI NOV 21 2014
UPDATE TO ZONES SENT OUT TO ACCOMMODATE LATEST TEMP TRENDS FROM
AREA OBS. LOW LEVEL CLOUDS COVER STILL LINGERING OVER EASTERN
EDGES OF THE FORECAST AREA AND SHOULD CONTINUE TREK EASTWARD
OVERNIGHT. THIS WILL GIVE WAY TO MID LEVEL CLOUDS WHICH ARE
CURRENTLY CENTRAL/WESTERN AREAS. LATEST EASTERN ZONES OBS ARE
STARTING TO SHOW FOG DEVELOPING...SO HAVE LEFT THAT IN OVERNIGHT.
REST OF FORECAST ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 138 PM MST FRI NOV 21 2014
MAIN CONCERNS ARE EXTENT OF FOG TONIGHT FOLLOWED BY HOW MUCH TO
WARM UP THE TEMPERATURES ON SATURDAY. LARGE AREA OF STRATUS AND
SOME FOG TO OUR SOUTH AND SOUTHEAST AT THIS TIME. RETURN FLOW WILL
BE IN PLACE BY THE TIME SUN GOES DOWN AND THE LOW LEVEL INVERSION
STRENGTHENS. SO WOULD EXPECT THIS MOISTURE TO BE ABLE TO RETURN
NORTH AND MOVE INTO THE AREA BEFORE THE WINDS SHIFT TO A WEST TO
SOUTHWEST DIRECTION BY LATER TONIGHT AS A SURFACE TROUGH MOVES
THROUGH.
HRRR FOLLOWED BY RAP HAVE BEEN DOING VERY WELL IN THE DEPICTION OF
THIS LOW LEVEL MOISTURE FIELD. BASED ON THAT AND THE OBSERVATIONS
TO OUR SOUTH...WENT AHEAD AND FOLLOWED THE HRRR/RAP VERY CLOSELY
FOR THE CLOUD COVER AND FOG FOR TONIGHT. FOG/LOW CLOUDS SHOULD
STAY IN THE EASTERN HALF TO TWO THIRDS OF THE AREA. IF HRRR ENDS
UP BEING RIGHT THERE COULD BE SOME DENSE FOG POSSIBLE IN THE FAR
EASTERN PORTION.
FOG AND STRATUS DECREASE LATE TONIGHT AND EARLY TOMORROW AS
SURFACE TROUGH MOVES THROUGH AND SHIFTS/INCREASES THE WINDS FROM
THE WEST. AT THIS TIME THE FOG SHOULD END BY MID MORNING. ONCE THE
FOG/CLOUDS CLEAR OFF THERE WILL BE PLENTIFUL SUNSHINE AND
DOWNSLOPE WINDS THROUGH 700 MB. COMBINATION OF DRY AIR MASS AND
GROUND COMBINED WITH THE ABUNDANT SUNSHINE AND DOWNSLOPE WINDS
WILL ALLOW FOR A GOOD WARMUP.
QUESTION IS HOW MUCH. THE NWP AND ESPECIALLY THE 2 METER GUIDANCE
HAS BEEN RUNNING COOL DURING THE LAST WEEK. AT THIS TIME WENT
ABOVE GUIDANCE IN MOST PLACES WITH 60S...MOSTLY MIDDLE AND UPPER
60S....ACROSS THE ENTIRE AREA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 210 PM MST FRI NOV 21 2014
FOR THE EXTENDED FORECAST PERIOD...VARIABLE WEATHER CONDITIONS ARE
EXPECTED THROUGHOUT DUE TO PASSING COLD FRONTS UNDER A NORTHWEST
FLOW REGIME. OVERALL...THE PATTERN REMAINS FAIRLY CONSISTENT WITH
LITTLE CHANCE OF MAJOR PRECIPITATION-PRODUCING SYSTEMS REACHING THE
REGION. PRIMARY CHANGE TO THIS EXTENDED PACKAGE WAS TO REMOVE
PRECIPITATION CHANCES FOR THANKSGIVING. MORE DETAILS ON THIS BELOW.
FOR SATURDAY NIGHT INTO SUNDAY MORNING...A STRONG COLD FRONT PASSAGE
IS ANTICIPATED. TEMPERATURES WILL BE SLOW TO FALL SATURDAY NIGHT DUE
TO INCREASING CLOUD COVER. THEN...A QUICK DROP IN TEMPERATURES AND
GUSTY NORTH WINDS ARE LIKELY IMMEDIATELY BEHIND THE FRONT. AS THE
FRONT PASSES THROUGH...THE ATMOSPHERE MOISTENS AT LOW LEVELS WHEN
THE COOLER AIR INTRUDES. THERE SHOULD BE ENOUGH MID-LEVEL LIFT AND
MOISTURE FOR RAIN/SNOW SHOWERS DEVELOPMENT BUT THE QUESTION OVER THE
PAST FEW FORECAST RUNS HAS BEEN WHETHER OR NOT THIS PRECIPITATION
REACHES THE GROUND. BASED ON LATEST GUIDANCE...THERE SHOULD BE A
SMALL WINDOW OF OPPORTUNITY FOR MEASURABLE PRECIPITATION TO REACH
THE GROUND AHEAD OF INCOMING POST-FRONTAL DRY AIR. THEREFORE...
PLACED A SLIGHT CHANCE FOR MEASURABLE PRECIPITATION INTO THE
FORECAST AND MAINTAINED SPRINKLES/FLURRIES MENTION SURROUNDING THE
SLIGHT CHANCE POPS.
MAIN STORY FOR THE REST OF SUNDAY THROUGH MONDAY SHOULD BE
BREEZY/WINDY CONDITIONS AND COOL TEMPERATURES. WITH PERSISTENT COLD
AIR ADVECTION AND POSSIBLE CLOUD COVER OVERHEAD...HAVE A HARD TIME
BELIEVING THAT THE REGION WILL BE ABLE TO REACH MEX/MET/ECE GUIDANCE
TEMPERATURES. WENT BELOW GUIDANCE FOR HIGH TEMPERATURES DUE TO THIS
THINKING. REGARDING THE WINDS...MODELS ARE NOT IN STRONG AGREEMENT
WITH RESPECT TO HOW STRONG THE WINDS WILL BE AND WHEN THE STRONGEST
WINDS WILL OCCUR. ANY POSSIBLE CLOUD COVER ALSO MESSES WITH
ANTICIPATED MIXING HEIGHTS SO HARD TO TELL HOW STRONG THE MIXED DOWN
GUSTS WILL BE AT THIS TIME. WITHOUT A STRONG CUT-OFF LOW PRESSURE
SYSTEM PRESENT...CURRENTLY DO NOT BELIEVE THAT THIS WILL BE A MAJOR
WIND EVENT. TYPICAL COLD/WINDY HIGH PLAINS DAYS ARE FORECAST WITH
NORTH WINDS 20-30 MPH...GUSTING TO 45 MPH AND HIGH TEMPERATURES IN
THE LOW TO UPPER 40S.
BEYOND MONDAY...A WEAK UPPER LEVEL DISTURBANCE MOVES THROUGH THE
HIGH PLAINS TUESDAY INTO TUESDAY NIGHT. THE CR INITIALIZATION
PROCEDURE DID NOT INCLUDE POPS AND WITH A DRY LAYER OF AIR AT THE
SURFACE...THOUGHT THIS WAS APPROPRIATE. POPS MAY NEED TO BE INCLUDED
AT A LATER TIME BUT MODEL CONSISTENCY WAS NOT STRONG ENOUGH FOR
INCLUSION WITH THIS RUN.
ANOTHER STRONG UPPER LEVEL DISTURBANCE SWINGS SOUTH OVER THE PLAINS
AND INTO THE MID-MISSISSIPPI VALLEY BY THURSDAY. THIS SYSTEM SHOULD
FORCE A BACKDOOR COLD FRONT INTO THE HIGH PLAINS. IT IS HARD TO TELL
HOW FAR SOUTHWEST THIS FRONT WILL REACH AND THERE IS A STRONG CHANCE
FOR A LARGE TEMPERATURE GRADIENT ACROSS THE REGION. CURRENT
THANKSGIVING FORECAST CALLS FOR A HIGH OF 38 DEGREES AT MCCOOK
NEBRASKA...44 AT GOODLAND KANSAS AND 52 AT KIT CARSON COLORADO.
MODELS TRENDED PRECIPITATION CHANCES FOR THANKSGIVING DOWN AND
BELIEVE THIS IS ACCURATE CONSIDERING A RIDGE OF HIGH PRESSURE WILL
BUILD IN FROM THE WEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 433 PM MST FRI NOV 21 2014
KGLD WILL SEE VFR CONDITIONS THROUGH THE FORECAST PERIOD WITH A
MIX OF SKC-SCT150. WINDS SSW AROUND 10KTS.
KMCK WILL SEE MOSTLY VFR CONDITIONS WITH A MIX OF SKC AND
SCT150-250. BKN020 IS POSSIBLE FROM 02Z-04Z SAT. WINDS SOUTH
AROUND 10KTS...BECOMING WSW AROUND 10KTS BY 06Z SAT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...JN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
255 PM EST SAT NOV 22 2014
.UPDATE...
ISSUED AT 150 PM EST SAT NOV 22 2014
FRESHENED UP TEMPS WITH LATEST OBS IN MANY LOCATIONS IN THE UPPER 50S
TO LOWER 60S THIS AFTERNOON. OTHER THAN THAT NO MAJOR CHANGES PLANNED
THIS UPDATE.
UPDATE ISSUED AT 1050 AM EST SAT NOV 22 2014
TEMPERATURES IN THE NORTHERN PART OF THE CWA NEAR THE BLUEGRASS
CONTINUE TO WARM INTO THE LOWER 50S WHILE A FEW VALLEY SPOTS ACROSS
THE CWA CONTINUE TO STRUGGLE UP INTO THE LOWER 40S. THEREFORE DID
FRESHEN TEMPS/DEWPOINTS ACROSS THE REGION TO MATCH CURRENT
OBS. GIVEN ABUNDANT SUNSHINE AND RETURN FLOW FROM SURFACE HIGH
TEMPERATURES ARE STILL EXPECTED TO REACH THE UPPER 50S TO LOWER 60S
AREA WIDE TODAY. WSR-88D RADAR CONTINUES TO INDICATE SOME SPRINKLES
ACROSS THE FAR NORTH CWA/BLUEGRASS REGIONS THIS MORNING. THESE
RETURNS HAVE BEEN LIGHT IN MOST CASES AND EXPECT MUCH OF THE RETURNS
SEEN ON RADAR ARE PROBABLY NOT REACHING THE GROUND. HOWEVER DID OPT
TO KEEP SPRINKLES JUST A BIT LONGER IN THE NORTHERN TIP OF THE CWA
THIS MORNING INTO AROUND THE NOON TIME FRAME GIVEN THAT REGION WOULD
LIKELY SEE THE HIGHEST RADAR RETURNS.
UPDATE ISSUED AT 747 AM EST SAT NOV 22 2014
TEMPERATURES CONTINUE TO WARM ACROSS THE AREA...ESPECIALLY OUT IN THE
WEST...WHERE EKQ IS CURRENTLY REPORTING IN THE MID 40S. FURTHER
EAST...VALLEYS STILL REMAIN DECOUPLED...WITH THE PAINTSVILLE MESONET
STILL REPORTING 20 DEGREES AND OUR COOP IN INEZ REPORTING AT 21
DEGREES. THE RADAR CONTINUES TO SHOW LIGHT RETURNS SKIMMING BY THE
BLUEGRASS COUNTIES. FORTUNATELY...TEMPERATURES HAVE WARMED ABOVE
FREEZING FOR THE MAJORITY OF THE AREA...AND THE LATEST RADAR AND
SHORT RANGE MODEL GUIDANCE CONTINUES TO SUGGEST ONLY SPRINKLES FOR
THE NEXT FEW HOURS. AS SUCH...HAVE MERELY FRESHENED UP THE
HOURLY TEMPERATURE AND DEW POINT TRENDS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM EST SAT NOV 22 2014
THE LATEST SURFACE MAP FEATURES A LARGE AREA OF HIGH PRESSURE ACROSS
THE EASTERN CONUS...WITH LOW PRESSURE CRUISING THROUGH ONTARIO.
ALOFT...FAIRLY PROGRESSIVE FLOW IS IN PLACE...WITH A WEAKER SHORT
WAVE MOVING THROUGH THE OHIO VALLEY. A STRONGER VORT IS ROTATING
ALONG NORTHERN MEXICO...WHILE ADDITIONAL SHORT WAVE ENERGY IS MOVING
ACROSS THE PACIFIC NORTHWEST.
ANOTHER CHILLY NIGHT HAS BEEN ON TAP FOR EASTERN KENTUCKY...ALTHOUGH
NOT AS COLD AS LAST NIGHT. THERE ARE A FEW VALLEYS IN THE FAR EAST
REMAINING IN THE UPPER TEENS...WHILE LOW TO MID 20S ARE COMMON IN THE
BROADER VALLEYS. RIDGETOPS ARE IN THE 30S THANKS TO LIGHT SOUTH TO
SOUTHEAST WINDS. A DECENT 850 MB JET HAS DEVELOPED ACROSS THE OHIO VALLEY
OVERNIGHT...WITH LIGHT PRECIPITATION BREAKING OUT ACROSS MOST OF
INDIANA AND DOWN INTO WESTERN KENTUCKY. THE LATEST HRRR MAY SUPPORT A
FEW SPRINKLES ACROSS THE I-64 CORRIDOR TOWARDS DAWN...HOWEVER GIVEN
THE DRY AIR IN PLACE CHANCES OF MEASURABLE PRECIPITATION LOOK LOW.
ONCE THE SPRINKLES SKIRT BY TO THE NORTH EARLY THIS MORNING...DRY
CONDITIONS WILL REMAIN IN PLACE THANKS TO LOW LEVEL SOUTHEASTERLY
FLOW. HIGHS TODAY WILL APPROACH THE 60 DEGREE MARK IN
PLACES...TEMPERATURES THAT WE HAVE NOT SEEN IN ABOUT A WEEK AND A
HALF. MEANWHILE...NORTHERN STREAM SHORT WAVE ENERGY WILL TRAVERSE THE
U.S./CANADIAN BORDER...WHILE THE SOUTHERN STREAM VORT CONTINUES TO
SLIDE EAST. THE VORT WILL THEN SWING MORE NORTHEAST...REACHING THE
TENNESSEE VALLEY BY LATE IN THE DAY ON SUNDAY. THIS WILL RESULT IN
SURFACE LOW PRESSURE ORGANIZING ACROSS THE PLAINS...EVENTUALLY
CONGLOMERATING ACROSS THE OHIO VALLEY LATE IN THE PERIOD.
EASTERN KENTUCKY WILL ENJOY A MILDER NIGHT TONIGHT...AS WARM AIR
ADVECTION CONTINUES OUT AHEAD OF THE APPROACHING SYSTEM FROM THE
WEST. LOWS WILL BOTTOM OUT IN THE LOWER 30S IN THE MORE SHELTERED
VALLEYS IN THE EAST...WHILE OTHER LOCATIONS WILL SEE UPPER 30S AND
LOWER 40S. A WARM FRONT/MID-LEVEL SHORT WAVE WILL APPROACH THE AREA
FROM THE SOUTHWEST ON SUNDAY...WITH WIDESPREAD SHOWER ACTIVITY
BREAKING OUT ACROSS EASTERN KENTUCKY IN THE AFTERNOON. HAVE CONTINUED
TO DOWNPLAY THE QPF AMOUNTS IN THE FAR EAST WITH DOWNSLOPE FLOW IN
PLACE. DESPITE THE SHOWERS MOVING IN...HIGHS WILL MAKE IT BACK INTO
THE UPPER 50S AND LOWER 60S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 255 PM EST SAT NOV 22 2014
THE MODELS ARE IN REASONABLE AGREEMENT ALOFT AT THE START OF THE
EXTENDED PORTION OF THE FORECAST AND CARRY ON THAT WAY THROUGH
TUESDAY BEFORE THE ECMWF BREAKS RANK. IT TAKES A STRONG SHORTWAVE
FROM THE NORTHERN PLAINS INTO THE LOWER OHIO VALLEY IN CONTRAST TO
THE GFS VERSION THAT KEEP ITS ENERGY COINCIDENT WITH THE MAIN TROUGH
SWEEPING THROUGH THE AREA ON TUESDAY. THE GEM SORT OF SPLITS THE
DIFFERENCE WITH A SLOWER MAIN TROUGH BUT WITH LOWER HEIGHTS THROUGH
THE UPPER MIDWEST AND NORTHERN PLAINS. BY FRIDAY THE MODELS ARE QUITE
OUT OF SYNC WITH THE GEM/S LOW HEIGHTS HANGING BACK OVER THE MID
SECTION OF THE NATION WHILE THE ECMWF BODILY MOVES ITS SECONDARY
TROUGH TO THE EAST COAST AND THE GFS HAS A FLATTER TROUGH OVER THE
OHIO VALLEY. INTERESTINGLY ENOUGH THE GFS AND ECMWF DO GET BACK IN
STEP WITH EACH OTHER FOR THE WEEKEND AS THEY BOTH DEPICT NEARLY FLAT
NORTHWEST FLOW OVER THE AREA ALONG WITH WEAK ENERGY APPROACHING FROM
THE WEST COAST. GIVEN THE UNCERTAINTY WITH THE MID TO LATE PORTION OF
THE EXTENDED WILL FAVOR A BLENDED SOLUTION FOR WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE A GRADUAL COOL DOWN IN THE WAKE OF A
LARGE SYSTEM ROLLING INTO QUEBEC. A MOSTLY DRY COLD FRONT DOES CROSS
THE STATE ON MONDAY WITH A BKN BAND OF SHOWERS EXPECTED. THE DEEPER
MOISTURE FROM THIS SYSTEM/S WRAP AROUND SHOULD STAY OFF TO THE NORTH
AND EAST LEAVING MAINLY JUST SOME EXTRA CLOUDS AND LOW POPS BEHIND.
THE ECMWF AND GFS TAKE A WAVE UP THE SOUTHEAST COAST EARLY WEDNESDAY
BRUSHING BY EAST KENTUCKY TO THE EAST. AT THIS POINT...CANNOT RULE
OUT A FEW STRAY SHOWERS OF RAIN OR SNOW...MAINLY AT THE HIGHER
ELEVATIONS...SLIPPING INTO THE CWA AS THE LOW PASSES. BOTH THE GFS
AND ECMWF THEN TAKE A SFC LOW THROUGH THE GREAT LAKES WITH THE FORMER
MORE NORTHEAST AND STRONGER THAN THE LATTER. IT IS IN THE WAKE OF
THIS LOW...AND ITS RE-ENFORCING COLD FRONT...THAT THE COLDER AIR
FINALLY SURGES INTO EAST KENTUCKY...IN THE ECMWF...ALONG WITH SOME
UPSLOPE AND GREAT LAKES ENHANCED PCPN. THE GFS KEEPS THE WORST OF THE
COLD AIR TO THE NORTH OF THE AREA THROUGH THE END OF THE WEEK ALONG
WITH JUST SPOTTY PCPN CHANCES ALONG THE NEARBY BOUNDARY. SPLITTING
THE DIFFERENCE HERE MAKES FOR A COMPLICATED FORECAST...BUT THAT IS
THE BEST WE CAN DO WITHOUT A MODEL BREAK TOWARD ONE SOLUTION OR
THE OTHER. FOR THE START OF THE WEEKEND...HIGH PRESSURE WILL MOST
LIKELY KEEP THE PCPN AT BAY...GENERALLY OFF TO THE NORTH AND WEST BUT
IT DOES START TO PULL OFF TO THE SOUTHEAST AND MAY ALLOW SOMETHING TO
SLIP IN LATE.
THE CR GRID LOAD PROVIDED A GOOD START THROUGH THE EXTENDED FORECAST
WITH CHANGES MAINLY MADE TO FINE TUNE THE POPS EARLY ON. DID ALSO
MAKE SOME MINOR CHANGES TO THE LOWS BASED ON TERRAIN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 747 AM EST SAT NOV 22 2014
EXPECT VFR CONDITIONS TO HOLD ON THROUGH THE PERIOD. SOME PASSING LOW
CLOUDS BETWEEN 4 AND 5K FEET AGL WILL BE SEEN THIS MORNING...AND THEN
ONCE AGAIN BETWEEN 06 AND 12Z. OTHERWISE MOST CLOUD COVER WILL BE AT
OR ABOVE 10K FEET AGL. WINDS WILL REMAIN OUT OF THE SOUTH AND
SOUTHEAST...AT OR AROUND 5 KTS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...GEOGERIAN
LONG TERM...GREIF
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
153 PM EST SAT NOV 22 2014
.UPDATE...
ISSUED AT 150 PM EST SAT NOV 22 2014
FRESHENED UP TEMPS WITH LATEST OBS IN MANY LOCATIONS IN THE UPPER 50S
TO LOWER 60S THIS AFTERNOON. OTHER THAN THAT NO MAJOR CHANGES PLANNED
THIS UPDATE.
UPDATE ISSUED AT 1050 AM EST SAT NOV 22 2014
TEMPERATURES IN THE NORTHERN PART OF THE CWA NEAR THE BLUEGRASS
CONTINUE TO WARM INTO THE LOWER 50S WHILE A FEW VALLEY SPOTS ACROSS
THE CWA CONTINUE TO STRUGGLE UP INTO THE LOWER 40S. THEREFORE DID
FRESHEN TEMPS/DEWPOINTS ACROSS THE REGION TO MATCH CURRENT
OBS. GIVEN ABUNDANT SUNSHINE AND RETURN FLOW FROM SURFACE HIGH
TEMPERATURES ARE STILL EXPECTED TO REACH THE UPPER 50S TO LOWER 60S
AREA WIDE TODAY. WSR-88D RADAR CONTINUES TO INDICATE SOME SPRINKLES
ACROSS THE FAR NORTH CWA/BLUEGRASS REGIONS THIS MORNING. THESE
RETURNS HAVE BEEN LIGHT IN MOST CASES AND EXPECT MUCH OF THE RETURNS
SEEN ON RADAR ARE PROBABLY NOT REACHING THE GROUND. HOWEVER DID OPT
TO KEEP SPRINKLES JUST A BIT LONGER IN THE NORTHERN TIP OF THE CWA
THIS MORNING INTO AROUND THE NOON TIME FRAME GIVEN THAT REGION WOULD
LIKELY SEE THE HIGHEST RADAR RETURNS.
UPDATE ISSUED AT 747 AM EST SAT NOV 22 2014
TEMPERATURES CONTINUE TO WARM ACROSS THE AREA...ESPECIALLY OUT IN THE
WEST...WHERE EKQ IS CURRENTLY REPORTING IN THE MID 40S. FURTHER
EAST...VALLEYS STILL REMAIN DECOUPLED...WITH THE PAINTSVILLE MESONET
STILL REPORTING 20 DEGREES AND OUR COOP IN INEZ REPORTING AT 21
DEGREES. THE RADAR CONTINUES TO SHOW LIGHT RETURNS SKIMMING BY THE
BLUEGRASS COUNTIES. FORTUNATELY...TEMPERATURES HAVE WARMED ABOVE
FREEZING FOR THE MAJORITY OF THE AREA...AND THE LATEST RADAR AND
SHORT RANGE MODEL GUIDANCE CONTINUES TO SUGGEST ONLY SPRINKLES FOR
THE NEXT FEW HOURS. AS SUCH...HAVE MERELY FRESHENED UP THE
HOURLY TEMPERATURE AND DEW POINT TRENDS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM EST SAT NOV 22 2014
THE LATEST SURFACE MAP FEATURES A LARGE AREA OF HIGH PRESSURE ACROSS
THE EASTERN CONUS...WITH LOW PRESSURE CRUISING THROUGH ONTARIO.
ALOFT...FAIRLY PROGRESSIVE FLOW IS IN PLACE...WITH A WEAKER SHORT
WAVE MOVING THROUGH THE OHIO VALLEY. A STRONGER VORT IS ROTATING
ALONG NORTHERN MEXICO...WHILE ADDITIONAL SHORT WAVE ENERGY IS MOVING
ACROSS THE PACIFIC NORTHWEST.
ANOTHER CHILLY NIGHT HAS BEEN ON TAP FOR EASTERN KENTUCKY...ALTHOUGH
NOT AS COLD AS LAST NIGHT. THERE ARE A FEW VALLEYS IN THE FAR EAST
REMAINING IN THE UPPER TEENS...WHILE LOW TO MID 20S ARE COMMON IN THE
BROADER VALLEYS. RIDGETOPS ARE IN THE 30S THANKS TO LIGHT SOUTH TO
SOUTHEAST WINDS. A DECENT 850 MB JET HAS DEVELOPED ACROSS THE OHIO VALLEY
OVERNIGHT...WITH LIGHT PRECIPITATION BREAKING OUT ACROSS MOST OF
INDIANA AND DOWN INTO WESTERN KENTUCKY. THE LATEST HRRR MAY SUPPORT A
FEW SPRINKLES ACROSS THE I-64 CORRIDOR TOWARDS DAWN...HOWEVER GIVEN
THE DRY AIR IN PLACE CHANCES OF MEASURABLE PRECIPITATION LOOK LOW.
ONCE THE SPRINKLES SKIRT BY TO THE NORTH EARLY THIS MORNING...DRY
CONDITIONS WILL REMAIN IN PLACE THANKS TO LOW LEVEL SOUTHEASTERLY
FLOW. HIGHS TODAY WILL APPROACH THE 60 DEGREE MARK IN
PLACES...TEMPERATURES THAT WE HAVE NOT SEEN IN ABOUT A WEEK AND A
HALF. MEANWHILE...NORTHERN STREAM SHORT WAVE ENERGY WILL TRAVERSE THE
U.S./CANADIAN BORDER...WHILE THE SOUTHERN STREAM VORT CONTINUES TO
SLIDE EAST. THE VORT WILL THEN SWING MORE NORTHEAST...REACHING THE
TENNESSEE VALLEY BY LATE IN THE DAY ON SUNDAY. THIS WILL RESULT IN
SURFACE LOW PRESSURE ORGANIZING ACROSS THE PLAINS...EVENTUALLY
CONGLOMERATING ACROSS THE OHIO VALLEY LATE IN THE PERIOD.
EASTERN KENTUCKY WILL ENJOY A MILDER NIGHT TONIGHT...AS WARM AIR
ADVECTION CONTINUES OUT AHEAD OF THE APPROACHING SYSTEM FROM THE
WEST. LOWS WILL BOTTOM OUT IN THE LOWER 30S IN THE MORE SHELTERED
VALLEYS IN THE EAST...WHILE OTHER LOCATIONS WILL SEE UPPER 30S AND
LOWER 40S. A WARM FRONT/MID-LEVEL SHORT WAVE WILL APPROACH THE AREA
FROM THE SOUTHWEST ON SUNDAY...WITH WIDESPREAD SHOWER ACTIVITY
BREAKING OUT ACROSS EASTERN KENTUCKY IN THE AFTERNOON. HAVE CONTINUED
TO DOWNPLAY THE QPF AMOUNTS IN THE FAR EAST WITH DOWNSLOPE FLOW IN
PLACE. DESPITE THE SHOWERS MOVING IN...HIGHS WILL MAKE IT BACK INTO
THE UPPER 50S AND LOWER 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 337 AM EST SAT NOV 22 2014
STILL SOME QUESTION AS TO HOW FAST THE TROUGH AXIS SHIFTS TO THE
NORTH SUNDAY EVENING. GFS IS MUCH MORE PROGRESSIVE ON BRINGING THE
DRY SLOT IN QUICKLY SUNDAY EVENING...WHILE THE ECMWF HOLDS IT BACK
EARLY ON. BASIC THINKING IS THAT EVEN IF THE DRY SLOT MOVES IN
FASTER...WE MAY STILL GET DEVELOPMENT INTO THE WARM SECTOR THROUGH
THE NIGHT OR POSSIBLY EVEN SOME MEASURABLE DRIZZLE. THUS...WILL
MAINTAIN HIGH CHANCE TO LIKELY POPS THROUGH THE FIRST HALF OF THE
NIGHT...WITH DRIZZLE BECOMING MORE LIKELY AS THE NIGHT PROGRESSES.
ON MONDAY...A SHARP COLD FRONT WILL PUSH INTO AND CROSS THE AREA.
THIS SHOULD AGAIN BRING HIGHER CHANCES FOR SHOWERS AS IT CROSSES THE
AREA THROUGH EARLY TO MID AFTERNOON. IN THE WAKE OF THE
FRONT...TEMPERATURES WILL TAKE A TUMBLE IN THE AFTERNOON AND EVENING
HOURS. AFTER CLIMBING INTO THE LOW 60S...TEMPERATURES BY THE EVENING
SHOULD SETTLE BACK INTO THE 40S. STILL LOOKS LIKE A WINDY DAY...WITH
925MB WINDS TOPPING 35 KNOTS AS THE FRONT CROSSES THE AREA. ANY
SHOWER ACTIVITY MAY ACTUALLY HELP TO MIX DOWN SOME ISOLATED HIGHER
GUSTS TO 40 OR 45 MPH.
SURFACE HIGH PRESSURE SHOULD MOVE INTO THE OHIO RIVER VALLEY MONDAY
NIGHT WITH DRY WEATHER RETURNING. ATTENTION WILL THEN TURN TO A
POSSIBLE NOREASTER AS AN AREA OF LOW PRESSURE MOVES UP THE EASTERN
US COAST. 00Z ECMWF HAS SHIFTED THE TRACK OF THIS LOW BACK TO THE
WEST...BRINGING MOISTURE INTO THE APPALACHIAN MOUNTAINS. GOING TO
MAINTAIN THE DRY FORECAST...BUT IF THIS SYSTEM TRENDS ANY FARTHER
WEST...MAY NEED TO INSERT SOME POPS BY WEDNESDAY.
MODELS REALLY DIVERGE THEREAFTER AS WE HEAD INTO THANKSGIVING DAY.
GFS BUILDS A RIDGE OVER THE OHIO RIVER VALLEY...SUGGESTING
TEMPERATURES MAY REACH INTO THE 50S...WHILE THE ECMWF DIGS OUT
ANOTHER SHARP TROUGH AND WOULD PUT TEMPERATURES MORE INTO THE 30S
WITH A GOOD CHANCE FOR SNOW. CLEARLY THIS IS A LARGE DIFFERENCE IN
THE MODELS...AND PUTS LOTS OF UNCERTAINTY ON THE THANKSGIVING
FORECAST AND BEYOND. FOR NOW...WILL GO WITH A COMPROMISED
FORECAST...WITH A SLIGHT EDGE TOWARDS THE COLDER ECMWF AS IT HAS
BEEN VERY CONSISTENT ON THE COLDER SOLUTION. WILL ALSO MAINTAIN LOW
POPS WEDNESDAY NIGHT INTO THURSDAY NIGHT...AND GO WITH A MIXTURE OF
RAIN/SNOW THROUGH THIS PERIOD. IT DOES LOOK REGARDLESS OF
THANKSGIVING DAY...MODELS POINT TO A MUCH COLDER END TO THE
WEEK...WITH TEMPERATURES STAYING WELL BELOW NORMAL INTO FRIDAY AND
SATURDAY. WE SHOULD SEE DRIER WEATHER FOR FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 747 AM EST SAT NOV 22 2014
EXPECT VFR CONDITIONS TO HOLD ON THROUGH THE PERIOD. SOME PASSING LOW
CLOUDS BETWEEN 4 AND 5K FEET AGL WILL BE SEEN THIS MORNING...AND THEN
ONCE AGAIN BETWEEN 06 AND 12Z. OTHERWISE MOST CLOUD COVER WILL BE AT
OR ABOVE 10K FEET AGL. WINDS WILL REMAIN OUT OF THE SOUTH AND
SOUTHEAST...AT OR AROUND 5 KTS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
1053 AM EST SAT NOV 22 2014
.UPDATE...
ISSUED AT 1050 AM EST SAT NOV 22 2014
TEMPERATURES IN THE NORTHERN PART OF THE CWA NEAR THE BLUEGRASS
CONTINUE TO WARM INTO THE LOWER 50S WHILE A FEW VALLEY SPOTS ACROSS
THE CWA CONTINUE TO STRUGGLE UP INTO THE LOWER 40S. THEREFORE DID
FRESHEN TEMPS/DEWPOINTS ACROSS THE REGION TO MATCH CURRENT
OBS. GIVEN ABUNDANT SUNSHINE AND RETURN FLOW FROM SURFACE HIGH
TEMPERATURES ARE STILL EXPECTED TO REACH THE UPPER 50S TO LOWER 60S
AREA WIDE TODAY. WSR-88D RADAR CONTINUES TO INDICATE SOME SPRINKLES
ACROSS THE FAR NORTH CWA/BLUEGRASS REGIONS THIS MORNING. THESE
RETURNS HAVE BEEN LIGHT IN MOST CASES AND EXPECT MUCH OF THE RETURNS
SEEN ON RADAR ARE PROBABLY NOT REACHING THE GROUND. HOWEVER DID OPT
TO KEEP SPRINKLES JUST A BIT LONGER IN THE NORTHERN TIP OF THE CWA
THIS MORNING INTO AROUND THE NOON TIME FRAME GIVEN THAT REGION WOULD
LIKELY SEE THE HIGHEST RADAR RETURNS.
UPDATE ISSUED AT 747 AM EST SAT NOV 22 2014
TEMPERATURES CONTINUE TO WARM ACROSS THE AREA...ESPECIALLY OUT IN THE
WEST...WHERE EKQ IS CURRENTLY REPORTING IN THE MID 40S. FURTHER
EAST...VALLEYS STILL REMAIN DECOUPLED...WITH THE PAINTSVILLE MESONET
STILL REPORTING 20 DEGREES AND OUR COOP IN INEZ REPORTING AT 21
DEGREES. THE RADAR CONTINUES TO SHOW LIGHT RETURNS SKIMMING BY THE
BLUEGRASS COUNTIES. FORTUNATELY...TEMPERATURES HAVE WARMED ABOVE
FREEZING FOR THE MAJORITY OF THE AREA...AND THE LATEST RADAR AND
SHORT RANGE MODEL GUIDANCE CONTINUES TO SUGGEST ONLY SPRINKLES FOR
THE NEXT FEW HOURS. AS SUCH...HAVE MERELY FRESHENED UP THE
HOURLY TEMPERATURE AND DEW POINT TRENDS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM EST SAT NOV 22 2014
THE LATEST SURFACE MAP FEATURES A LARGE AREA OF HIGH PRESSURE ACROSS
THE EASTERN CONUS...WITH LOW PRESSURE CRUISING THROUGH ONTARIO.
ALOFT...FAIRLY PROGRESSIVE FLOW IS IN PLACE...WITH A WEAKER SHORT
WAVE MOVING THROUGH THE OHIO VALLEY. A STRONGER VORT IS ROTATING
ALONG NORTHERN MEXICO...WHILE ADDITIONAL SHORT WAVE ENERGY IS MOVING
ACROSS THE PACIFIC NORTHWEST.
ANOTHER CHILLY NIGHT HAS BEEN ON TAP FOR EASTERN KENTUCKY...ALTHOUGH
NOT AS COLD AS LAST NIGHT. THERE ARE A FEW VALLEYS IN THE FAR EAST
REMAINING IN THE UPPER TEENS...WHILE LOW TO MID 20S ARE COMMON IN THE
BROADER VALLEYS. RIDGETOPS ARE IN THE 30S THANKS TO LIGHT SOUTH TO
SOUTHEAST WINDS. A DECENT 850 MB JET HAS DEVELOPED ACROSS THE OHIO VALLEY
OVERNIGHT...WITH LIGHT PRECIPITATION BREAKING OUT ACROSS MOST OF
INDIANA AND DOWN INTO WESTERN KENTUCKY. THE LATEST HRRR MAY SUPPORT A
FEW SPRINKLES ACROSS THE I-64 CORRIDOR TOWARDS DAWN...HOWEVER GIVEN
THE DRY AIR IN PLACE CHANCES OF MEASURABLE PRECIPITATION LOOK LOW.
ONCE THE SPRINKLES SKIRT BY TO THE NORTH EARLY THIS MORNING...DRY
CONDITIONS WILL REMAIN IN PLACE THANKS TO LOW LEVEL SOUTHEASTERLY
FLOW. HIGHS TODAY WILL APPROACH THE 60 DEGREE MARK IN
PLACES...TEMPERATURES THAT WE HAVE NOT SEEN IN ABOUT A WEEK AND A
HALF. MEANWHILE...NORTHERN STREAM SHORT WAVE ENERGY WILL TRAVERSE THE
U.S./CANADIAN BORDER...WHILE THE SOUTHERN STREAM VORT CONTINUES TO
SLIDE EAST. THE VORT WILL THEN SWING MORE NORTHEAST...REACHING THE
TENNESSEE VALLEY BY LATE IN THE DAY ON SUNDAY. THIS WILL RESULT IN
SURFACE LOW PRESSURE ORGANIZING ACROSS THE PLAINS...EVENTUALLY
CONGLOMERATING ACROSS THE OHIO VALLEY LATE IN THE PERIOD.
EASTERN KENTUCKY WILL ENJOY A MILDER NIGHT TONIGHT...AS WARM AIR
ADVECTION CONTINUES OUT AHEAD OF THE APPROACHING SYSTEM FROM THE
WEST. LOWS WILL BOTTOM OUT IN THE LOWER 30S IN THE MORE SHELTERED
VALLEYS IN THE EAST...WHILE OTHER LOCATIONS WILL SEE UPPER 30S AND
LOWER 40S. A WARM FRONT/MID-LEVEL SHORT WAVE WILL APPROACH THE AREA
FROM THE SOUTHWEST ON SUNDAY...WITH WIDESPREAD SHOWER ACTIVITY
BREAKING OUT ACROSS EASTERN KENTUCKY IN THE AFTERNOON. HAVE CONTINUED
TO DOWNPLAY THE QPF AMOUNTS IN THE FAR EAST WITH DOWNSLOPE FLOW IN
PLACE. DESPITE THE SHOWERS MOVING IN...HIGHS WILL MAKE IT BACK INTO
THE UPPER 50S AND LOWER 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 337 AM EST SAT NOV 22 2014
STILL SOME QUESTION AS TO HOW FAST THE TROUGH AXIS SHIFTS TO THE
NORTH SUNDAY EVENING. GFS IS MUCH MORE PROGRESSIVE ON BRINGING THE
DRY SLOT IN QUICKLY SUNDAY EVENING...WHILE THE ECMWF HOLDS IT BACK
EARLY ON. BASIC THINKING IS THAT EVEN IF THE DRY SLOT MOVES IN
FASTER...WE MAY STILL GET DEVELOPMENT INTO THE WARM SECTOR THROUGH
THE NIGHT OR POSSIBLY EVEN SOME MEASURABLE DRIZZLE. THUS...WILL
MAINTAIN HIGH CHANCE TO LIKELY POPS THROUGH THE FIRST HALF OF THE
NIGHT...WITH DRIZZLE BECOMING MORE LIKELY AS THE NIGHT PROGRESSES.
ON MONDAY...A SHARP COLD FRONT WILL PUSH INTO AND CROSS THE AREA.
THIS SHOULD AGAIN BRING HIGHER CHANCES FOR SHOWERS AS IT CROSSES THE
AREA THROUGH EARLY TO MID AFTERNOON. IN THE WAKE OF THE
FRONT...TEMPERATURES WILL TAKE A TUMBLE IN THE AFTERNOON AND EVENING
HOURS. AFTER CLIMBING INTO THE LOW 60S...TEMPERATURES BY THE EVENING
SHOULD SETTLE BACK INTO THE 40S. STILL LOOKS LIKE A WINDY DAY...WITH
925MB WINDS TOPPING 35 KNOTS AS THE FRONT CROSSES THE AREA. ANY
SHOWER ACTIVITY MAY ACTUALLY HELP TO MIX DOWN SOME ISOLATED HIGHER
GUSTS TO 40 OR 45 MPH.
SURFACE HIGH PRESSURE SHOULD MOVE INTO THE OHIO RIVER VALLEY MONDAY
NIGHT WITH DRY WEATHER RETURNING. ATTENTION WILL THEN TURN TO A
POSSIBLE NOREASTER AS AN AREA OF LOW PRESSURE MOVES UP THE EASTERN
US COAST. 00Z ECMWF HAS SHIFTED THE TRACK OF THIS LOW BACK TO THE
WEST...BRINGING MOISTURE INTO THE APPALACHIAN MOUNTAINS. GOING TO
MAINTAIN THE DRY FORECAST...BUT IF THIS SYSTEM TRENDS ANY FARTHER
WEST...MAY NEED TO INSERT SOME POPS BY WEDNESDAY.
MODELS REALLY DIVERGE THEREAFTER AS WE HEAD INTO THANKSGIVING DAY.
GFS BUILDS A RIDGE OVER THE OHIO RIVER VALLEY...SUGGESTING
TEMPERATURES MAY REACH INTO THE 50S...WHILE THE ECMWF DIGS OUT
ANOTHER SHARP TROUGH AND WOULD PUT TEMPERATURES MORE INTO THE 30S
WITH A GOOD CHANCE FOR SNOW. CLEARLY THIS IS A LARGE DIFFERENCE IN
THE MODELS...AND PUTS LOTS OF UNCERTAINTY ON THE THANKSGIVING
FORECAST AND BEYOND. FOR NOW...WILL GO WITH A COMPROMISED
FORECAST...WITH A SLIGHT EDGE TOWARDS THE COLDER ECMWF AS IT HAS
BEEN VERY CONSISTENT ON THE COLDER SOLUTION. WILL ALSO MAINTAIN LOW
POPS WEDNESDAY NIGHT INTO THURSDAY NIGHT...AND GO WITH A MIXTURE OF
RAIN/SNOW THROUGH THIS PERIOD. IT DOES LOOK REGARDLESS OF
THANKSGIVING DAY...MODELS POINT TO A MUCH COLDER END TO THE
WEEK...WITH TEMPERATURES STAYING WELL BELOW NORMAL INTO FRIDAY AND
SATURDAY. WE SHOULD SEE DRIER WEATHER FOR FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 747 AM EST SAT NOV 22 2014
EXPECT VFR CONDITIONS TO HOLD ON THROUGH THE PERIOD. SOME PASSING LOW
CLOUDS BETWEEN 4 AND 5K FEET AGL WILL BE SEEN THIS MORNING...AND THEN
ONCE AGAIN BETWEEN 06 AND 12Z. OTHERWISE MOST CLOUD COVER WILL BE AT
OR ABOVE 10K FEET AGL. WINDS WILL REMAIN OUT OF THE SOUTH AND
SOUTHEAST...AT OR AROUND 5 KTS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
747 AM EST SAT NOV 22 2014
.UPDATE...
ISSUED AT 747 AM EST SAT NOV 22 2014
TEMPERATURES CONTINUE TO WARM ACROSS THE AREA...ESPECIALLY OUT IN THE
WEST...WHERE EKQ IS CURRENTLY REPORTING IN THE MID 40S. FURTHER
EAST...VALLEYS STILL REMAIN DECOUPLED...WITH THE PAINTSVILLE MESONET
STILL REPORTING 20 DEGREES AND OUR COOP IN INEZ REPORTING AT 21
DEGREES. THE RADAR CONTINUES TO SHOW LIGHT RETURNS SKIMMING BY THE
BLUEGRASS COUNTIES. FORTUNATELY...TEMPERATURES HAVE WARMED ABOVE
FREEZING FOR THE MAJORITY OF THE AREA...AND THE LATEST RADAR AND
SHORT RANGE MODEL GUIDANCE CONTINUES TO SUGGEST ONLY SPRINKLES FOR
THE NEXT FEW HOURS. AS SUCH...HAVE MERELY FRESHENED UP THE
HOURLY TEMPERATURE AND DEW POINT TRENDS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM EST SAT NOV 22 2014
THE LATEST SURFACE MAP FEATURES A LARGE AREA OF HIGH PRESSURE ACROSS
THE EASTERN CONUS...WITH LOW PRESSURE CRUISING THROUGH ONTARIO.
ALOFT...FAIRLY PROGRESSIVE FLOW IS IN PLACE...WITH A WEAKER SHORT
WAVE MOVING THROUGH THE OHIO VALLEY. A STRONGER VORT IS ROTATING
ALONG NORTHERN MEXICO...WHILE ADDITIONAL SHORT WAVE ENERGY IS MOVING
ACROSS THE PACIFIC NORTHWEST.
ANOTHER CHILLY NIGHT HAS BEEN ON TAP FOR EASTERN KENTUCKY...ALTHOUGH
NOT AS COLD AS LAST NIGHT. THERE ARE A FEW VALLEYS IN THE FAR EAST
REMAINING IN THE UPPER TEENS...WHILE LOW TO MID 20S ARE COMMON IN THE
BROADER VALLEYS. RIDGETOPS ARE IN THE 30S THANKS TO LIGHT SOUTH TO
SOUTHEAST WINDS. A DECENT 850 MB JET HAS DEVELOPED ACROSS THE OHIO VALLEY
OVERNIGHT...WITH LIGHT PRECIPITATION BREAKING OUT ACROSS MOST OF
INDIANA AND DOWN INTO WESTERN KENTUCKY. THE LATEST HRRR MAY SUPPORT A
FEW SPRINKLES ACROSS THE I-64 CORRIDOR TOWARDS DAWN...HOWEVER GIVEN
THE DRY AIR IN PLACE CHANCES OF MEASURABLE PRECIPITATION LOOK LOW.
ONCE THE SPRINKLES SKIRT BY TO THE NORTH EARLY THIS MORNING...DRY
CONDITIONS WILL REMAIN IN PLACE THANKS TO LOW LEVEL SOUTHEASTERLY
FLOW. HIGHS TODAY WILL APPROACH THE 60 DEGREE MARK IN
PLACES...TEMPERATURES THAT WE HAVE NOT SEEN IN ABOUT A WEEK AND A
HALF. MEANWHILE...NORTHERN STREAM SHORT WAVE ENERGY WILL TRAVERSE THE
U.S./CANADIAN BORDER...WHILE THE SOUTHERN STREAM VORT CONTINUES TO
SLIDE EAST. THE VORT WILL THEN SWING MORE NORTHEAST...REACHING THE
TENNESSEE VALLEY BY LATE IN THE DAY ON SUNDAY. THIS WILL RESULT IN
SURFACE LOW PRESSURE ORGANIZING ACROSS THE PLAINS...EVENTUALLY
CONGLOMERATING ACROSS THE OHIO VALLEY LATE IN THE PERIOD.
EASTERN KENTUCKY WILL ENJOY A MILDER NIGHT TONIGHT...AS WARM AIR
ADVECTION CONTINUES OUT AHEAD OF THE APPROACHING SYSTEM FROM THE
WEST. LOWS WILL BOTTOM OUT IN THE LOWER 30S IN THE MORE SHELTERED
VALLEYS IN THE EAST...WHILE OTHER LOCATIONS WILL SEE UPPER 30S AND
LOWER 40S. A WARM FRONT/MID-LEVEL SHORT WAVE WILL APPROACH THE AREA
FROM THE SOUTHWEST ON SUNDAY...WITH WIDESPREAD SHOWER ACTIVITY
BREAKING OUT ACROSS EASTERN KENTUCKY IN THE AFTERNOON. HAVE CONTINUED
TO DOWNPLAY THE QPF AMOUNTS IN THE FAR EAST WITH DOWNSLOPE FLOW IN
PLACE. DESPITE THE SHOWERS MOVING IN...HIGHS WILL MAKE IT BACK INTO
THE UPPER 50S AND LOWER 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 337 AM EST SAT NOV 22 2014
STILL SOME QUESTION AS TO HOW FAST THE TROUGH AXIS SHIFTS TO THE
NORTH SUNDAY EVENING. GFS IS MUCH MORE PROGRESSIVE ON BRINGING THE
DRY SLOT IN QUICKLY SUNDAY EVENING...WHILE THE ECMWF HOLDS IT BACK
EARLY ON. BASIC THINKING IS THAT EVEN IF THE DRY SLOT MOVES IN
FASTER...WE MAY STILL GET DEVELOPMENT INTO THE WARM SECTOR THROUGH
THE NIGHT OR POSSIBLY EVEN SOME MEASURABLE DRIZZLE. THUS...WILL
MAINTAIN HIGH CHANCE TO LIKELY POPS THROUGH THE FIRST HALF OF THE
NIGHT...WITH DRIZZLE BECOMING MORE LIKELY AS THE NIGHT PROGRESSES.
ON MONDAY...A SHARP COLD FRONT WILL PUSH INTO AND CROSS THE AREA.
THIS SHOULD AGAIN BRING HIGHER CHANCES FOR SHOWERS AS IT CROSSES THE
AREA THROUGH EARLY TO MID AFTERNOON. IN THE WAKE OF THE
FRONT...TEMPERATURES WILL TAKE A TUMBLE IN THE AFTERNOON AND EVENING
HOURS. AFTER CLIMBING INTO THE LOW 60S...TEMPERATURES BY THE EVENING
SHOULD SETTLE BACK INTO THE 40S. STILL LOOKS LIKE A WINDY DAY...WITH
925MB WINDS TOPPING 35 KNOTS AS THE FRONT CROSSES THE AREA. ANY
SHOWER ACTIVITY MAY ACTUALLY HELP TO MIX DOWN SOME ISOLATED HIGHER
GUSTS TO 40 OR 45 MPH.
SURFACE HIGH PRESSURE SHOULD MOVE INTO THE OHIO RIVER VALLEY MONDAY
NIGHT WITH DRY WEATHER RETURNING. ATTENTION WILL THEN TURN TO A
POSSIBLE NOREASTER AS AN AREA OF LOW PRESSURE MOVES UP THE EASTERN
US COAST. 00Z ECMWF HAS SHIFTED THE TRACK OF THIS LOW BACK TO THE
WEST...BRINGING MOISTURE INTO THE APPALACHIAN MOUNTAINS. GOING TO
MAINTAIN THE DRY FORECAST...BUT IF THIS SYSTEM TRENDS ANY FARTHER
WEST...MAY NEED TO INSERT SOME POPS BY WEDNESDAY.
MODELS REALLY DIVERGE THEREAFTER AS WE HEAD INTO THANKSGIVING DAY.
GFS BUILDS A RIDGE OVER THE OHIO RIVER VALLEY...SUGGESTING
TEMPERATURES MAY REACH INTO THE 50S...WHILE THE ECMWF DIGS OUT
ANOTHER SHARP TROUGH AND WOULD PUT TEMPERATURES MORE INTO THE 30S
WITH A GOOD CHANCE FOR SNOW. CLEARLY THIS IS A LARGE DIFFERENCE IN
THE MODELS...AND PUTS LOTS OF UNCERTAINTY ON THE THANKSGIVING
FORECAST AND BEYOND. FOR NOW...WILL GO WITH A COMPROMISED
FORECAST...WITH A SLIGHT EDGE TOWARDS THE COLDER ECMWF AS IT HAS
BEEN VERY CONSISTENT ON THE COLDER SOLUTION. WILL ALSO MAINTAIN LOW
POPS WEDNESDAY NIGHT INTO THURSDAY NIGHT...AND GO WITH A MIXTURE OF
RAIN/SNOW THROUGH THIS PERIOD. IT DOES LOOK REGARDLESS OF
THANKSGIVING DAY...MODELS POINT TO A MUCH COLDER END TO THE
WEEK...WITH TEMPERATURES STAYING WELL BELOW NORMAL INTO FRIDAY AND
SATURDAY. WE SHOULD SEE DRIER WEATHER FOR FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 747 AM EST SAT NOV 22 2014
EXPECT VFR CONDITIONS TO HOLD ON THROUGH THE PERIOD. SOME PASSING LOW
CLOUDS BETWEEN 4 AND 5K FEET AGL WILL BE SEEN THIS MORNING...AND THEN
ONCE AGAIN BETWEEN 06 AND 12Z. OTHERWISE MOST CLOUD COVER WILL BE AT
OR ABOVE 10K FEET AGL. WINDS WILL REMAIN OUT OF THE SOUTH AND
SOUTHEAST...AT OR AROUND 5 KTS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
337 AM EST SAT NOV 22 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM EST SAT NOV 22 2014
THE LATEST SURFACE MAP FEATURES A LARGE AREA OF HIGH PRESSURE ACROSS
THE EASTERN CONUS...WITH LOW PRESSURE CRUISING THROUGH ONTARIO.
ALOFT...FAIRLY PROGRESSIVE FLOW IS IN PLACE...WITH A WEAKER SHORT
WAVE MOVING THROUGH THE OHIO VALLEY. A STRONGER VORT IS ROTATING
ALONG NORTHERN MEXICO...WHILE ADDITIONAL SHORT WAVE ENERGY IS MOVING
ACROSS THE PACIFIC NORTHWEST.
ANOTHER CHILLY NIGHT HAS BEEN ON TAP FOR EASTERN KENTUCKY...ALTHOUGH
NOT AS COLD AS LAST NIGHT. THERE ARE A FEW VALLEYS IN THE FAR EAST
REMAINING IN THE UPPER TEENS...WHILE LOW TO MID 20S ARE COMMON IN THE
BROADER VALLEYS. RIDGETOPS ARE IN THE 30S THANKS TO LIGHT SOUTH TO
SOUTHEAST WINDS. A DECENT 850 MB JET HAS DEVELOPED ACROSS THE OHIO VALLEY
OVERNIGHT...WITH LIGHT PRECIPITATION BREAKING OUT ACROSS MOST OF
INDIANA AND DOWN INTO WESTERN KENTUCKY. THE LATEST HRRR MAY SUPPORT A
FEW SPRINKLES ACROSS THE I-64 CORRIDOR TOWARDS DAWN...HOWEVER GIVEN
THE DRY AIR IN PLACE CHANCES OF MEASURABLE PRECIPITATION LOOK LOW.
ONCE THE SPRINKLES SKIRT BY TO THE NORTH EARLY THIS MORNING...DRY
CONDITIONS WILL REMAIN IN PLACE THANKS TO LOW LEVEL SOUTHEASTERLY
FLOW. HIGHS TODAY WILL APPROACH THE 60 DEGREE MARK IN
PLACES...TEMPERATURES THAT WE HAVE NOT SEEN IN ABOUT A WEEK AND A
HALF. MEANWHILE...NORTHERN STREAM SHORT WAVE ENERGY WILL TRAVERSE THE
U.S./CANADIAN BORDER...WHILE THE SOUTHERN STREAM VORT CONTINUES TO
SLIDE EAST. THE VORT WILL THEN SWING MORE NORTHEAST...REACHING THE
TENNESSEE VALLEY BY LATE IN THE DAY ON SUNDAY. THIS WILL RESULT IN
SURFACE LOW PRESSURE ORGANIZING ACROSS THE PLAINS...EVENTUALLY
CONGLOMERATING ACROSS THE OHIO VALLEY LATE IN THE PERIOD.
EASTERN KENTUCKY WILL ENJOY A MILDER NIGHT TONIGHT...AS WARM AIR
ADVECTION CONTINUES OUT AHEAD OF THE APPROACHING SYSTEM FROM THE
WEST. LOWS WILL BOTTOM OUT IN THE LOWER 30S IN THE MORE SHELTERED
VALLEYS IN THE EAST...WHILE OTHER LOCATIONS WILL SEE UPPER 30S AND
LOWER 40S. A WARM FRONT/MID-LEVEL SHORT WAVE WILL APPROACH THE AREA
FROM THE SOUTHWEST ON SUNDAY...WITH WIDESPREAD SHOWER ACTIVITY
BREAKING OUT ACROSS EASTERN KENTUCKY IN THE AFTERNOON. HAVE CONTINUED
TO DOWNPLAY THE QPF AMOUNTS IN THE FAR EAST WITH DOWNSLOPE FLOW IN
PLACE. DESPITE THE SHOWERS MOVING IN...HIGHS WILL MAKE IT BACK INTO
THE UPPER 50S AND LOWER 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 337 AM EST SAT NOV 22 2014
STILL SOME QUESTION AS TO HOW FAST THE TROUGH AXIS SHIFTS TO THE
NORTH SUNDAY EVENING. GFS IS MUCH MORE PROGRESSIVE ON BRINGING THE
DRY SLOT IN QUICKLY SUNDAY EVENING...WHILE THE ECMWF HOLDS IT BACK
EARLY ON. BASIC THINKING IS THAT EVEN IF THE DRY SLOT MOVES IN
FASTER...WE MAY STILL GET DEVELOPMENT INTO THE WARM SECTOR THROUGH
THE NIGHT OR POSSIBLY EVEN SOME MEASURABLE DRIZZLE. THUS...WILL
MAINTAIN HIGH CHANCE TO LIKELY POPS THROUGH THE FIRST HALF OF THE
NIGHT...WITH DRIZZLE BECOMING MORE LIKELY AS THE NIGHT PROGRESSES.
ON MONDAY...A SHARP COLD FRONT WILL PUSH INTO AND CROSS THE AREA.
THIS SHOULD AGAIN BRING HIGHER CHANCES FOR SHOWERS AS IT CROSSES THE
AREA THROUGH EARLY TO MID AFTERNOON. IN THE WAKE OF THE
FRONT...TEMPERATURES WILL TAKE A TUMBLE IN THE AFTERNOON AND EVENING
HOURS. AFTER CLIMBING INTO THE LOW 60S...TEMPERATURES BY THE EVENING
SHOULD SETTLE BACK INTO THE 40S. STILL LOOKS LIKE A WINDY DAY...WITH
925MB WINDS TOPPING 35 KNOTS AS THE FRONT CROSSES THE AREA. ANY
SHOWER ACTIVITY MAY ACTUALLY HELP TO MIX DOWN SOME ISOLATED HIGHER
GUSTS TO 40 OR 45 MPH.
SURFACE HIGH PRESSURE SHOULD MOVE INTO THE OHIO RIVER VALLEY MONDAY
NIGHT WITH DRY WEATHER RETURNING. ATTENTION WILL THEN TURN TO A
POSSIBLE NOREASTER AS AN AREA OF LOW PRESSURE MOVES UP THE EASTERN
US COAST. 00Z ECMWF HAS SHIFTED THE TRACK OF THIS LOW BACK TO THE
WEST...BRINGING MOISTURE INTO THE APPALACHIAN MOUNTAINS. GOING TO
MAINTAIN THE DRY FORECAST...BUT IF THIS SYSTEM TRENDS ANY FARTHER
WEST...MAY NEED TO INSERT SOME POPS BY WEDNESDAY.
MODELS REALLY DIVERGE THEREAFTER AS WE HEAD INTO THANKSGIVING DAY.
GFS BUILDS A RIDGE OVER THE OHIO RIVER VALLEY...SUGGESTING
TEMPERATURES MAY REACH INTO THE 50S...WHILE THE ECMWF DIGS OUT
ANOTHER SHARP TROUGH AND WOULD PUT TEMPERATURES MORE INTO THE 30S
WITH A GOOD CHANCE FOR SNOW. CLEARLY THIS IS A LARGE DIFFERENCE IN
THE MODELS...AND PUTS LOTS OF UNCERTAINTY ON THE THANKSGIVING
FORECAST AND BEYOND. FOR NOW...WILL GO WITH A COMPROMISED
FORECAST...WITH A SLIGHT EDGE TOWARDS THE COLDER ECMWF AS IT HAS
BEEN VERY CONSISTENT ON THE COLDER SOLUTION. WILL ALSO MAINTAIN LOW
POPS WEDNESDAY NIGHT INTO THURSDAY NIGHT...AND GO WITH A MIXTURE OF
RAIN/SNOW THROUGH THIS PERIOD. IT DOES LOOK REGARDLESS OF
THANKSGIVING DAY...MODELS POINT TO A MUCH COLDER END TO THE
WEEK...WITH TEMPERATURES STAYING WELL BELOW NORMAL INTO FRIDAY AND
SATURDAY. WE SHOULD SEE DRIER WEATHER FOR FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 105 AM EST SAT NOV 22 2014
BESIDES SOME PASSING CLOUD COVER FROM TIME TO TIME...MAINLY AT OR ABOVE
10K FEET AGL...VFR CONDITIONS WILL REIGN THROUGH THE PERIOD. WINDS
WILL REMAIN OUT OF THE SOUTH AND SOUTHEAST...REMAINING AT OR AROUND 5
KTS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
614 PM EST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 444 PM EST SUN NOV 23 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL
TROUGH ACROSS THE CENTRAL CONUS. THE MORE PROMINENT SHORTWAVE
TROUGHS WERE LOCATED OVER THE DAKOTAS...NEW MEXICO...AND NRN
MS. AT THE SFC...A TROUGH AND FRONTAL BOUNDARY EXTENDED FROM NE
MN THROUGH CNTRL IA TO LOW PRES OVER ERN OK. A BROAD SRLY FLOW OF
GULF MOISTURE INTO THE NRN LAKES HAS RESULTED IN AREAS OF DENSE FOG
OVER THE EXTENSIVE SNOW COVER. A WEAKER SHRTWV OVER WI AND
ASSOCIATED 850-700 MB FGEN SUPPORTED AN AREA OF RAIN THAT WAS
EXPANDING INTO SRN UPPER MI.
TONIGHT...EXPECT THAT THE RAIN WILL CONTINUE TO DEVELOP INTO UPPER
MI THIS EVENING...ESPECIALLY ACROSS THE SE HALF IN PROXIMITY TO THE
STRONGEST FGEN AND ISENTROPIC LIFT. ALTHOUGH AREAS OF DENSE FOG MAY
PERSIST INTO THIS EVENING...THE RAIN SHOULD HELP SCOUR OUT SOME OF
THE FOG FOR SLIGHTLY BETTER VSBY. BY LATE TONIGHT...THE RAIN IS
EXPECTED TO CONTINUE TO INCREASE IN COVERAGE/INTENSITY AS THE MID
LEVEL TROUGH DEEPENS...THE MS SHRTWV LIFTS TO THE GREAT LAKES WITH
INCREASING 700-500 MB QVECTOR CONV.
MONDAY...MODELS SUGGEST THAT THERE MAY BE A LULL IN THE PCPN
BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID LEVEL TROUGH MOVING
IN FROM THE UPPER MS VALLEY. AS THE DEEPENING SFC LOW NEAR THE
STRAITS AT 12Z/MON LIFTS QUICKLY TO THE NE THE COLDER AIR WILL ALSO
SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER TO SNOW
FROM 12Z-21Z FROM W TO EAST. THE PCPN CHANGEOVER WAS DELAYED
SLIGHTLY...PER MODEL TRENDS WITH A BLEND OF THE 12Z NAM AND REGIONAL
GEM 1000-850 LOW LEVEL THICKNESS USED FOR THE RAIN SNOW LINE. WITH
THE LOSS OF THE STRONGER LARGE SCALE FORCING/LIFT TIL AFTERNOON
MAINLY JUST LIGHT TO MODERATE LAKE ENAHANCED SNOW IS EXPECTED OVER
THE WEST HALF FOR NNW FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO
NEAR -8C WEST BY 18Z AND TO AROUND -12C ACROSS WEST AND CNTRL
LOCATIONS BY 00Z. SNOWFALL AMOUNTS IN THE 2 TO 4 RANGE WILL BE
POSSIBLE OVER THE WEST WITH ONLY AROUND AN INCH CENTRAL. A TIGHT
GRADIENT BEHIND THE LOW WILL BRING STRONG NRLY WINDS INTO THE AREA
PRODUCING SOME BLOWING AND DRIFTING SNOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 303 PM EST SUN NOV 23 2014
AT 00Z TUE...A SHORTWAVE WILL BE E OF THE CWA WITH THE ASSOCIATED
SFC LOW NEAR JAMES BAY. A WEAKENING UPPER TROUGH WILL BE OVER THE
FAR WRN CWA...WITH A RIDGE NW OF THE TROUGH. THE 12Z/23 NAM HAS COME
INTO BETTER AGREEMENT WITH 12Z/23 GFS AND 00Z/23 ECMWF IN SHOWING
LESS PHASING BETWEEN THE TWO FEATURES...AND THEREFORE HAVING MOST
/BUT NOT ALL/ OF THE SYNOPTIC SNOW NE OF THE CWA BY 00Z TUE. PRECIP
WILL BE ALL SNOW BY 00Z TUE AS 850MB TEMPS WILL FALL TO AOB -12C BY
12Z. WITH THE COLD AIRMASS...LAKE ENHANCEMENT WILL OCCUR IN NNW WIND
SNOWBELTS ALONG AND AHEAD OF THE TROUGH THAT WILL MOVE THROUGH THE
CWA BY 18Z TUE. BEHIND THE TROUGH...WINDS BECOME INCREASINGLY
ANTICYCLONIC...AND LOW LEVEL AIRMASS DRIER...AS THE RIDGE MOVES IN.
WILL CERTAINLY SEE DIMINISHING PRECIP COVERAGE/INTENSITY LATER TUE
INTO TUE NIGHT...BUT LES WILL NOT COMPLETELY END AS LOW LEVEL WINDS
FOCUS LES MORE OVER THE KEWEENAW PENINSULA. WNW WIND SNOWBELTS OF
THE NRN HURON MOUNTAINS AND OVER ALGER COUNTY WILL BE FAVORED FOR
THE GREATEST SNOWFALL AMOUNTS...WITH EXPECTATIONS OF 6-8 INCHES OF
SNOW MON NIGHT AND TUE IN THESE FAVORED LOCATIONS. ELSEWHERE NEAR
LAKE SUPERIOR AROUND 4 INCHES IS EXPECTED MON NIGHT/TUE...WITH LESS
AMOUNTS OF 1-3 INCHES INLAND. AFTER COORDINATION WITH SHORT TERM
SHIFT...LAKE EFFECT SNOW ADVISORIES HAVE BEEN ISSUED FOR ALL
COUNTIES ALONG LAKE SUPERIOR. AT LEAST FOR MON NIGHT/TUE...SNOW TO
LIQUID RATIOS SHOULD BE HIGH ENOUGH FOR THE LAKE EFFECT HEADLINE
INSTEAD OF WINTER WEATHER ADVISORIES. ALSO...BLOWING SNOW WILL OCCUR
ALONG LAKE SUPERIOR.
CONFIDENCE DECREASES SIGNIFICANTLY FOR WED THROUGH NEXT WEEKEND. FOR
WED INTO THU...MODELS AGREE IN SHOWING TWO SHORTWAVES MOVING INTO
THE CENTRAL CENTRAL U.S. WED...BUT DISAGREE ON THE
STRENGTH/TRACK/PHASING OF THE TWO WAVES...WHICH LEADS TO A WIDE
VARIETY OF SOLUTIONS FOR THE CWA. THE ECMWF PHASES THE WAVES OVER
THE REGION...WHICH LEADS TO A 1003MB SFC LOW MOVING FROM NEAR MPX AT
12Z WED TO LAKE HURON AT 12Z THU. THIS SOLUTION WOULD RESULT IN
SIGNIFICANT SNOWFALL AMOUNTS ACROSS THE CWA WED INTO THU. THE GFS
KEEP THE WAVES OUT OF PHASE AND THE SRN MOST WAVE MUCH FARTHER
S...LEAVING JUST A LITTLE LAKE ENHANCEMENT WED INTO WED NIGHT AS THE
NRN SHORTWAVE CROSSES THE AREA. OTHER MODELS HAVE VARYING SOLUTIONS
BETWEEN THESE TWO EXTREMES. NOT REALLY ABLE TO PICK BETWEEN THE
MODELS GIVEN THE NORMAL LOW CONFIDENCE WITH SHORTWAVE ENERGY AND
GENERALLY GOOD RUN TO RUN CONTINUITY OF THE GFS AND ECMWF WITH THIS
SYSTEM.
REGARDLESS OF SOLUTION...SHOULD SEE LES THU INTO THU NIGHT IN NW
WIND SNOWBELTS UNDER -18C TO -20C 850MB TEMPS. HOWEVER...THE GFS
THEN BRINGS WINDS OUT OF THE SW THU NIGHT AHEAD OF A STRONG CLIPPER
SYSTEM IT SHOWS MOVING INTO THE NRN PLAINS THU NIGHT AND ACROSS THE
CWA FRI NIGHT. ALL THE WHILE...THE ECMWF SHOWS A STRONG SFC HIGH
MOVING FROM THE NRN PLAINS TO THE MID MISSISSIPPI VALLEY. THE ECMWF
WOULD KEEP LES GOING IN NW-WNW SNOWBELTS THROUGH FRI...WHILE THE GFS
SOLUTION WOULD OBVIOUSLY NOT GIVEN THE CHANGE IN WINDS WITH THE SFC
LOW MOVING ACROSS THE CWA AND 850MB TEMPS INCREASE TO AROUND
0C...BUT DOES BRING LES BACK ON SAT BEHIND THE CLIPPER. MODELS DO
SHOW SOME AGREEMENT IN LOW LEVEL WINDS BECOMING FROM THE WSW BY SUN
WITH CONTINUED /BUT LIGHTER/ LES. WILL STICK CLOSER TO THE PREVIOUS
FORECAST GIVEN THE HIGH UNCERTAINTY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 613 PM EST SUN NOV 23 2014
WITH LOW LEVEL MOIST/WARM ADVECTION CONTINUING INTO THE
AREA...PERSISTENT LOW CIGS AND FOG WILL CONTINUE OVERNIGHT WITH
VLIFR TO LIFR CONDITIONS PERSISTING. AS A DEEP LOW PRESSURE SYSTEM
MOVES EAST OF THE AREA MONDAY MORNING WINDS WILL BECOME NORTH AND
QUICKLY STRENGTHEN WITH ANY RAIN CHANGING TO SNOW. LOW CIGS AND VIS
WILL CONTINUE AT ALL TAF SITES THROUGH THE FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 PM EST SUN NOV 23 2014
WINDS WILL BE VARIABLE TONIGHT AS TROUGH CROSSES LAKE SUPERIOR. A
DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR ON MONDAY.
NORTHERLY WINDS WILL INCREASE TO GALES 35-45 KTS BY MONDAY MORNING
INTO MONDAY NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS
TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 PM MONDAY TO 4 PM EST TUESDAY
FOR MIZ006-007-085.
DENSE FOG ADVISORY UNTIL 2 AM EST /1 AM CST/ MONDAY FOR
MIZ004>007-010>014-085.
LAKE EFFECT SNOW ADVISORY FROM 7 AM EST /6 AM CST/ MONDAY TO 7
AM EST /6 AM CST/ TUESDAY FOR MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM MONDAY TO 6 AM EST TUESDAY
FOR MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY FROM 1 PM MONDAY TO 1 PM EST TUESDAY
FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
603 PM EST SAT NOV 22 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 420 PM EST SAT NOV 22 2014
WV IMAGERY AND RUC ANALYSIS INDICATED ZONAL FLOW ACROSS THE NRN
CONUS WITH A STRONG 170 KNOT 250 MB JET MOVING INTO THE PAC NW. A
SHORTWAVE TROUGH WAS MOVING THROUGH SRN SASK AND NRN MT. A VIGOROUS
SRN SHORTWAVE TROUGH WAS LOCATED OVER WRN TEXAS. AT THE SFC...SRLY
FLOW PREVAILED FROM THE GULF TOWARD THE UPPER MS VALLEY AND NRN
LAKES BTWN HIGH PRES OVER THE MID ATLANTIC AND A 984 MB LOW INTO SRN
SASK. WAA HAS PUSHED TEMPS INTO THE MID AND UPPER 30S ACROSS UPPER
MI. ALTHOUGH THE LOW LEVEL MOISTURE THINNED OUT ENOUGH FOR SOME
SUNSHINE THIS AFTERNOON...ESPECIALLY IN DOWNSLOPE LOCATIONS...CLOUDS
OVER NRN WI AND WRN UPPER MI WERE FILLING IN AGAIN ACROSS THE AREA.
TONIGHT...ANY LINGERING DRY LOW LEVEL AIR WILL FILL IN TONIGHT WITH
STRONG LOW LEVEL MOISTURE ADVECTION THIS EVENING. SO...EXPECT BETTER
CHANCES FOR PCPN AS DRIZZLE OR POSSIBLY FREEZING DRIZZLE AS A
SUBSTANTIAL DRY LAYER REMAINS ABOVE 900 MB. SOME FOG WILL BE POSSIBLE
AS WELL AS DEWPOINTS CLIMB TO AROUND FREEZING OR SLIGHTLY ABOVE BY
LATE TONIGHT. EXPECT THE BEST CHANCE FOR DRIZZLE OVER CNTRL UPPER MI
WITH AN UPSLOPE LOW LEVEL WIND COMPONENT SUPPORT...AND OVER THE EAST
CWA WITH ADDED MOISTURE OFF OF LAKE MICHIGAN. TEMPS MAY DROP OFF TO
NEAR FREEZING THIS EVENING AND SLOWLY CLIMB OVERNIGHT.
HOWEVER...SINCE MANY ROAD SURFACES MAY STILL BE BELOW FREEZING...ANY
DRIZZLE THAT FALLS COULD CREATE ICY/SLIPPERY CONDITIONS ON UNTREATED
ROADS.
SUN...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
THE STRONG MOISTURE ADVECTION CONTINUES AND 850-700 MB FGEN
INCREASES. THE GREATEST CHANCE IS EXPECTED OVER THE EAST IN
PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS THE DRY
LAYER FILLS IN ANY DRIZZLE WILL CHANGE OVER TO RAIN BY MID TO LATE
AFTERNOON. TEMPS WILL CLIMB ABOVE NORMAL INTO THE LOW TO MID 40S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 426 PM EST SAT NOV 22 2014
QUITE AN ACTIVE START TO THE PERIOD AS THE PHASING OF NORTHERN AND
SOUTHERN ENERGY WILL BE UNDERWAY ACROSS THE UPPER GREAT LAKES.
MODERATE RAINFALL SUNDAY NIGHT WILL GIVE WAY TO A TRANSITION TO SNOW
ON MONDAY AS THE SYSTEM MOVES NE OF THE REGION. THE INGREDIENTS ARE
STILL THERE FOR MODERATE TO POSSIBLY HEAVY SNOW ACROSS AT LEAST THE
WESTERN CWA MONDAY AFTERNOON AND NIGHT. AFTER A REPRIEVE LATE
TUESDAY...A CLIPPER SYSTEM LOOKS TO BRING LIGHT TO POSSIBLY MODERATE
SNOWFALL WEDNESDAY AFTERNOON INTO THANKSGIVING.
SUNDAY NIGHT THROUGH MONDAY NIGHT...FIRST A LOOK AT THE OVERALL
SYNOPTIC PATTERN. TWO POTENT MID-LEVEL SHORTWAVES...ONE TRACKING
EASTWARD OVER THE NORTHERN PLAINS AND THE OTHER MOVING NORTHEASTWARD
NEAR SOUTHERN IL AT 00Z MONDAY WILL BEGIN TO MERGE ACROSS THE UPPER
GREAT LAKES. THE NORTHERN STREAM IS A BIT SLOWER REACHING THE REGION
THAN THE SOUTHERN STREAM...RESULTING IN A BROADENING OF THE TROUGH
BY MONDAY MORNING. MEANWHILE...A DEVELOPING MODEST COUPLED JET
PATTERN WILL DEVELOP OVER THE UPPER GREAT LAKES. THE SOUTHERN WAVE
WILL BE OF MOST INTEREST INITIALLY AS IT INDUCES A RAPIDLY DEEPENING
LOW OVER ILLINOIS AT THE START OF THE PERIOD. WITH THE 12/18Z NAM
RUNS COMING INTO BETTER AGREEMENT WITH THE OTHER MODELS...CONFIDENCE
IS NOW HIGHER REGARDING THE OVERALL EVOLUTION OF THE SYSTEM. THE SFC
LOW IS PROGGED TO TRACK NEAR THE STRAITS OF MACKINAC AROUND 12Z
MONDAY. THE GEM/NAM/ECMWF HINT AT A SLIGHT DEVIATION TO THE LEFT/NW
MONDAY MORNING...WITH THE LOW CROSSING NEAR SAULT STE MARIE. THIS
LOOKS REASONABLE AS THE INFLUENCE OF THE NORTHERN TROUGH APPROACHES.
A LINGERING TROUGH WILL THEN REMAIN ACROSS UPPER MI ON MONDAY AS THE
MID-LEVEL TROUGH AXIS REACHES THE REGION AND THE SFC LOW MOVES TO
JUST SE OF JAMES BAY.
NOW A LOOK AT THE OVERALL PRECIP TYPE AND INTENSITY. MID/UPPER-LEVEL
DYNAMICS AND LOW-LEVEL THERMODYNAMICS SUPPORT MODERATE RAIN ACROSS
MAINLY CENTRAL AND EASTERN UPPER MI SUNDAY NIGHT. THE RIGHT ENTRANCE
OF A DEVELOPING...ALBEIT ANTICYCLONICALLY CURVED...UPPER JET WILL
MAXIMIZE UPPER DIVERGENCE OVER CENTRAL AND EASTERN UPPER MI WHILE
MID-LEVEL Q-VECTOR CONVERGENCE PEAKS OVER NORTHERN LOWER MI.
MEANWHILE...LOW-LEVEL MOISTURE TRANSPORT WILL BE RATHER IMPRESSIVE
ACROSS THE EASTERN CWA...THEN QUICKLY DIMINISH TOWARD THE WESTERN
CWA. A SUFFICIENTLY DEEP LOW-LEVEL WARM LAYER WILL KEEP PRECIP ALL
RAIN ACROSS THE CWA...THOUGH A TRANSITION TO SNOW WILL BE UNDERWAY
LATE SUNDAY NIGHT ACROSS THE WEST AS CAA BEGINS BEHIND THE LOW. ALL
THIS TOGETHER FAVORS MODERATE RAIN ACROSS THE EAST HALF SUNDAY
NIGHT...WITH AN INITIALLY SHARP CUTOFF TO THE WEST BEFORE THE
NORTHERN WAVE APPROACHES OVERNIGHT.
CAA TAKING HOLD ON MONDAY WILL QUICKLY TRANSITION THE RAIN TO SNOW
FROM WEST TO EAST THROUGHOUT THE DAY. THERE ARE SOME INDICATIONS
THAT A LOW-LEVEL WARM LAYER MAY TRY TO WRAP AROUND THE BACK SIDE OF
THE LOW LATE MORNING MORNING INTO THE AFTERNOON. SOME SLEET MAY MIX
IN WITH THE RAIN/SNOW...BUT THE TRANSITION FROM ALL RAIN SNOW SHOULD
NOT TAKE MORE THAN AN HOUR OR TWO. THINK THAT EVEN THE SHORELINE
LOCATIONS SHOULD TRANSITION QUICKLY GIVEN THEN COLDER THAN AVERAGE
LAKE TEMPS. TRANSITION TIMES LOOK TO BE AROUND 09Z FOR IWD...12Z FOR
A LINE FROM HOUGHTON TO IRON RIVER...AND 15Z FOR A LINE FROM
MARQUETTE TO IMT. BY 21Z...ALL BUT POSSIBLY LUCE COUNTY SHOULD
TRANSITION TO SNOW.
A FAIRLY IMPRESSIVE MID-LEVEL FGEN/DEFORMATION ZONE WILL SET UP OVER
THE WESTERN CWA BY MONDAY AFTERNOON. WITH SOME SNOWFLAKE FRACTURING
FROM THE HIGHER WINDS AND THE MAX LIFT INITIALLY OCCURRING AT TEMPS
JUST A BIT WARMER THAN THE DGZ...SNOW RATIOS MAY REMAIN LOW /10 TO
1/ THROUGH MONDAY MORNING. AS TEMPS CONTINUE TO FALL IN TO THE
AFTERNOON SNOW RATIOS WILL BE ON THE RISE ACROSS THE WEST. LOW-LEVEL
WINDS AVERAGING OUT THE NORTH COMBINED WITH LAKE-850MB DELTA TEMPS
SURPASSING 10C SUPPORT DECENT LAKE-ENHANCEMENT FOR THE NORTH WIND
SNOW BELTS THROUGHOUT MONDAY. THIS PATTERN WILL CONTINUE INTO MONDAY
EVENING AS THE CONSOLIDATED TROUGH SLOWS OVER THE AREA AND KEEPS A
SFC TROUGH EXTENDED ACROSS MUCH OF EASTERN UPPER MI. ON TOP OF THE
SNOW...THE CAA WITH A STRONG WNW TO ESE ISALLOBARIC COMPONENT FROM
THE RAPIDLY DEEPENING LOW WILL YIELD A QUICK INCREASE IN WIND FROM
THE N/NNW.
WHEN ALL IS SAID AND DONE...SNOWFALL MONDAY AND MONDAY NIGHT IS
EXPECTED TO BE 6 TO 10 INCHES BASICALLY NORTH OF M-28 AND WEST OF
MARQUETTE. ELSEWHERE ACROSS THE CWA...2-4 INCHES IS EXPECTED.
HOWEVER...HIGHER AMOUNTS OF UP TO 6 INCHES WILL BE POSSIBLE FOR THE
NNW WIND SNOW BELTS FROM SHOT POINT TO GRAND MARAIS. THREW AROUND
THE IDEA OF A WINTER STORM WATCH FOR THE NW HALF...BUT DECIDED
AGAINST IT GIVEN SOME DETAILS IN QPF AND PLACEMENT OF FORCING THAT
NEED TO BE IRONED OUT. HOWEVER...WINTER WX ADVISORY CRITERIA SHOULD
BE MET. HAVE OPTED TO ISSUE A SPECIAL WX STATEMENT AT THIS TIME TO
HIGHLIGHT THE POTENTIAL...BUT ALSO NOTE THE UNCERTAINTY IN AMOUNTS.
MAIN IMPACTS WILL BE RATHER SLUSHY ROADS IN THE AFTERNOON FOLLOWED
BY BLOWING AND DRIFTING OF THE SNOW OVERNIGHT AS SNOW RATIOS
INCREASE.
TUESDAY THROUGH WEDNESDAY NIGHT...WEAK MID-LEVEL RIDGING...LOW-LEVEL
WAA AND INVERSION HEIGHTS FALLING BELOW 3KFT WILL PUT A QUICK END TO
THE LES FROM WEST TO EAST THROUGHOUT THE DAY. A CLIPPER SHORTWAVE
WILL TRACK SE INTO THE UPPER MS VALLEY LATE TUESDAY. THE SHORTWAVE
LOOKS TO GET CAUGHT UP IN A LARGER-SCALE TROUGH OVER HUDSON
BAY...ULTIMATELY SLOWING ITS PROGRESSING AND SHIFTING IT TO A ENE
TRACK. WHERE THIS TAKES PLACE WILL BE CRUCIAL FOR DETERMINING SNOW
PROBABILITY/AMOUNTS FOR THE CWA. THE GFS IS THE FASTEST...BRINGING
WIDESPREAD ACCUMULATING SNOW TO THE AREA LATE TUESDAY NIGHT INTO
WEDNESDAY AFTERNOON. THE ECMWF TAKES AN INITIALLY MORE AGGRESSIVE
EVOLUTION...RESULTING THE THE TROUGH DIGGING FARTHER SOUTHEAST
BEFORE PIVOTING ACROSS SOUTHERN LAKE/LOWER MI. WITH THIS
SCENARIO...MOST OF THE SNOW HOLDS OFF UNTIL WEDNESDAY NIGHT. THE GEM
FOLLOWS A SOLUTION IN THE MIDDLE...BUT LEANS MORE IN LINE WITH THE
GFS. ATTM...CANNOT REALLY PIN DOWN AMOUNTS AND EXACT TIMING...THOUGH
THE PROSPECTS FOR SEVERAL INCHES OF ACCUMULATING SNOW SOMETIME LATE
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT ARE GROWING.
THANKSGIVING...DEPENDING ON WHAT MODEL SOLUTION PANS
OUT...WIDESPREAD SNOW MAY LINGER THROUGH THE MORNING OR END BEFORE
DAYBREAK. EITHER WAY...CAA BEHIND THE CLIPPER SHOULD YIELD LES FOR
THE N/NNW WIND BELTS DURING THE DAY. IT STILL LOOKS COLD...WITH
TEMPS MORE IN LINE WITH CHRISTMAS RATHER THAN THANKSGIVING.
HOWEVER...WITH THE SLOWER SOLUTION...THE ECMWF HAS A HARDER TIME
BRINGING THE COLDEST AIR INTO THE REGION.
FRIDAY AND SATURDAY...LONG RANGE MODELS HAVE BACKED OFF SOMEWHERE ON
A TRANSITION TO A MORE ZONAL AND MILD PATTERN BEGINNING FRIDAY AND
DELAY IT UNTIL LATE IN THE WEEKEND. THE OVERALL PATTERN LOOKS QUIET
BESIDE SOME LES FOR THE WNW WIND SNOW BELTS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 603 PM EST SAT NOV 22 2014
LOW CLOUDS ARE THE MAIN FORECAST ISSUE INTO SUNDAY. CONTINUING
MOISTURE FLOWING INTO THE AREA SHOULD RESULT IN LOWERING OF CIGS
TONIGHT. BASED ON UPSTREAM CIGS THIS MORNING OVER IA/MN/WI...EXPECT
CIGS TO FALL TO IFR LATE TONIGHT...OR EVEN LIFR...AS THE MOIST
LOW-LEVELS WILL BE ONLY BE ADDED TO BY ADDITIONAL MOISTURE AND
HELPED ALONG BY DEVELOPING UPSLOPE FLOW AT KCMX AND KSAW. AT THESE
SITES....PROBABLY WILL SEE DRIZZLE AND FOG AS WELL WITH VSBY LIKELY
REACHING IFR LATE TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EST SAT NOV 22 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL MOVE
TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL INCREASE TO
GALES 40-45 KTS MONDAY AFTN INTO MONDAY NIGHT. WINDS DIMINISH TO 25
KTS OR LESS LATER TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS
ON THURSDAY AS COLD AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE
BUILDING OVER THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE
LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ248>250-265-266.
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ242>245-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
427 PM EST SAT NOV 22 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 420 PM EST SAT NOV 22 2014
WV IMAGERY AND RUC ANALYSIS INDICATED ZONAL FLOW ACROSS THE NRN
CONUS WITH A STRONG 170 KNOT 250 MB JET MOVING INTO THE PAC NW. A
SHORTWAVE TROUGH WAS MOVING THROUGH SRN SASK AND NRN MT. A VIGOROUS
SRN SHORTWAVE TROUGH WAS LOCATED OVER WRN TEXAS. AT THE SFC...SRLY
FLOW PREVAILED FROM THE GULF TOWARD THE UPPER MS VALLEY AND NRN
LAKES BTWN HIGH PRES OVER THE MID ATLANTIC AND A 984 MB LOW INTO SRN
SASK. WAA HAS PUSHED TEMPS INTO THE MID AND UPPER 30S ACROSS UPPER
MI. ALTHOUGH THE LOW LEVEL MOISTURE THINNED OUT ENOUGH FOR SOME
SUNSHINE THIS AFTERNOON...ESPECIALLY IN DOWNSLOPE LOCATIONS...CLOUDS
OVER NRN WI AND WRN UPPER MI WERE FILLING IN AGAIN ACROSS THE AREA.
TONIGHT...ANY LINGERING DRY LOW LEVEL AIR WILL FILL IN TONIGHT WITH
STRONG LOW LEVEL MOISTURE ADVECTION THIS EVENING. SO...EXPECT BETTER
CHANCES FOR PCPN AS DRIZZLE OR POSSIBLY FREEZING DRIZZLE AS A
SUBSTANTIAL DRY LAYER REMAINS ABOVE 900 MB. SOME FOG WILL BE POSSIBLE
AS WELL AS DEWPOINTS CLIMB TO AROUND FREEZING OR SLIGHTLY ABOVE BY
LATE TONIGHT. EXPECT THE BEST CHANCE FOR DRIZZLE OVER CNTRL UPPER MI
WITH AN UPSLOPE LOW LEVEL WIND COMPONENT SUPPORT...AND OVER THE EAST
CWA WITH ADDED MOISTURE OFF OF LAKE MICHIGAN. TEMPS MAY DROP OFF TO
NEAR FREEZING THIS EVENING AND SLOWLY CLIMB OVERNIGHT.
HOWEVER...SINCE MANY ROAD SURFACES MAY STILL BE BELOW FREEZING...ANY
DRIZZLE THAT FALLS COULD CREATE ICY/SLIPPERY CONDITIONS ON UNTREATED
ROADS.
SUN...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
THE STRONG MOISTURE ADVECTION CONTINUES AND 850-700 MB FGEN
INCREASES. THE GREATEST CHANCE IS EXPECTED OVER THE EAST IN
PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS THE DRY
LAYER FILLS IN ANY DRIZZLE WILL CHANGE OVER TO RAIN BY MID TO LATE
AFTERNOON. TEMPS WILL CLIMB ABOVE NORMAL INTO THE LOW TO MID 40S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 426 PM EST SAT NOV 22 2014
QUITE AN ACTIVE START TO THE PERIOD AS THE PHASING OF NORTHERN AND
SOUTHERN ENERGY WILL BE UNDERWAY ACROSS THE UPPER GREAT LAKES.
MODERATE RAINFALL SUNDAY NIGHT WILL GIVE WAY TO A TRANSITION TO SNOW
ON MONDAY AS THE SYSTEM MOVES NE OF THE REGION. THE INGREDIENTS ARE
STILL THERE FOR MODERATE TO POSSIBLY HEAVY SNOW ACROSS AT LEAST THE
WESTERN CWA MONDAY AFTERNOON AND NIGHT. AFTER A REPRIEVE LATE
TUESDAY...A CLIPPER SYSTEM LOOKS TO BRING LIGHT TO POSSIBLY MODERATE
SNOWFALL WEDNESDAY AFTERNOON INTO THANKSGIVING.
SUNDAY NIGHT THROUGH MONDAY NIGHT...FIRST A LOOK AT THE OVERALL
SYNOPTIC PATTERN. TWO POTENT MID-LEVEL SHORTWAVES...ONE TRACKING
EASTWARD OVER THE NORTHERN PLAINS AND THE OTHER MOVING NORTHEASTWARD
NEAR SOUTHERN IL AT 00Z MONDAY WILL BEGIN TO MERGE ACROSS THE UPPER
GREAT LAKES. THE NORTHERN STREAM IS A BIT SLOWER REACHING THE REGION
THAN THE SOUTHERN STREAM...RESULTING IN A BROADENING OF THE TROUGH
BY MONDAY MORNING. MEANWHILE...A DEVELOPING MODEST COUPLED JET
PATTERN WILL DEVELOP OVER THE UPPER GREAT LAKES. THE SOUTHERN WAVE
WILL BE OF MOST INTEREST INITIALLY AS IT INDUCES A RAPIDLY DEEPENING
LOW OVER ILLINOIS AT THE START OF THE PERIOD. WITH THE 12/18Z NAM
RUNS COMING INTO BETTER AGREEMENT WITH THE OTHER MODELS...CONFIDENCE
IS NOW HIGHER REGARDING THE OVERALL EVOLUTION OF THE SYSTEM. THE SFC
LOW IS PROGGED TO TRACK NEAR THE STRAITS OF MACKINAC AROUND 12Z
MONDAY. THE GEM/NAM/ECMWF HINT AT A SLIGHT DEVIATION TO THE LEFT/NW
MONDAY MORNING...WITH THE LOW CROSSING NEAR SAULT STE MARIE. THIS
LOOKS REASONABLE AS THE INFLUENCE OF THE NORTHERN TROUGH APPROACHES.
A LINGERING TROUGH WILL THEN REMAIN ACROSS UPPER MI ON MONDAY AS THE
MID-LEVEL TROUGH AXIS REACHES THE REGION AND THE SFC LOW MOVES TO
JUST SE OF JAMES BAY.
NOW A LOOK AT THE OVERALL PRECIP TYPE AND INTENSITY. MID/UPPER-LEVEL
DYNAMICS AND LOW-LEVEL THERMODYNAMICS SUPPORT MODERATE RAIN ACROSS
MAINLY CENTRAL AND EASTERN UPPER MI SUNDAY NIGHT. THE RIGHT ENTRANCE
OF A DEVELOPING...ALBEIT ANTICYCLONICALLY CURVED...UPPER JET WILL
MAXIMIZE UPPER DIVERGENCE OVER CENTRAL AND EASTERN UPPER MI WHILE
MID-LEVEL Q-VECTOR CONVERGENCE PEAKS OVER NORTHERN LOWER MI.
MEANWHILE...LOW-LEVEL MOISTURE TRANSPORT WILL BE RATHER IMPRESSIVE
ACROSS THE EASTERN CWA...THEN QUICKLY DIMINISH TOWARD THE WESTERN
CWA. A SUFFICIENTLY DEEP LOW-LEVEL WARM LAYER WILL KEEP PRECIP ALL
RAIN ACROSS THE CWA...THOUGH A TRANSITION TO SNOW WILL BE UNDERWAY
LATE SUNDAY NIGHT ACROSS THE WEST AS CAA BEGINS BEHIND THE LOW. ALL
THIS TOGETHER FAVORS MODERATE RAIN ACROSS THE EAST HALF SUNDAY
NIGHT...WITH AN INITIALLY SHARP CUTOFF TO THE WEST BEFORE THE
NORTHERN WAVE APPROACHES OVERNIGHT.
CAA TAKING HOLD ON MONDAY WILL QUICKLY TRANSITION THE RAIN TO SNOW
FROM WEST TO EAST THROUGHOUT THE DAY. THERE ARE SOME INDICATIONS
THAT A LOW-LEVEL WARM LAYER MAY TRY TO WRAP AROUND THE BACK SIDE OF
THE LOW LATE MORNING MORNING INTO THE AFTERNOON. SOME SLEET MAY MIX
IN WITH THE RAIN/SNOW...BUT THE TRANSITION FROM ALL RAIN SNOW SHOULD
NOT TAKE MORE THAN AN HOUR OR TWO. THINK THAT EVEN THE SHORELINE
LOCATIONS SHOULD TRANSITION QUICKLY GIVEN THEN COLDER THAN AVERAGE
LAKE TEMPS. TRANSITION TIMES LOOK TO BE AROUND 09Z FOR IWD...12Z FOR
A LINE FROM HOUGHTON TO IRON RIVER...AND 15Z FOR A LINE FROM
MARQUETTE TO IMT. BY 21Z...ALL BUT POSSIBLY LUCE COUNTY SHOULD
TRANSITION TO SNOW.
A FAIRLY IMPRESSIVE MID-LEVEL FGEN/DEFORMATION ZONE WILL SET UP OVER
THE WESTERN CWA BY MONDAY AFTERNOON. WITH SOME SNOWFLAKE FRACTURING
FROM THE HIGHER WINDS AND THE MAX LIFT INITIALLY OCCURRING AT TEMPS
JUST A BIT WARMER THAN THE DGZ...SNOW RATIOS MAY REMAIN LOW /10 TO
1/ THROUGH MONDAY MORNING. AS TEMPS CONTINUE TO FALL IN TO THE
AFTERNOON SNOW RATIOS WILL BE ON THE RISE ACROSS THE WEST. LOW-LEVEL
WINDS AVERAGING OUT THE NORTH COMBINED WITH LAKE-850MB DELTA TEMPS
SURPASSING 10C SUPPORT DECENT LAKE-ENHANCEMENT FOR THE NORTH WIND
SNOW BELTS THROUGHOUT MONDAY. THIS PATTERN WILL CONTINUE INTO MONDAY
EVENING AS THE CONSOLIDATED TROUGH SLOWS OVER THE AREA AND KEEPS A
SFC TROUGH EXTENDED ACROSS MUCH OF EASTERN UPPER MI. ON TOP OF THE
SNOW...THE CAA WITH A STRONG WNW TO ESE ISALLOBARIC COMPONENT FROM
THE RAPIDLY DEEPENING LOW WILL YIELD A QUICK INCREASE IN WIND FROM
THE N/NNW.
WHEN ALL IS SAID AND DONE...SNOWFALL MONDAY AND MONDAY NIGHT IS
EXPECTED TO BE 6 TO 10 INCHES BASICALLY NORTH OF M-28 AND WEST OF
MARQUETTE. ELSEWHERE ACROSS THE CWA...2-4 INCHES IS EXPECTED.
HOWEVER...HIGHER AMOUNTS OF UP TO 6 INCHES WILL BE POSSIBLE FOR THE
NNW WIND SNOW BELTS FROM SHOT POINT TO GRAND MARAIS. THREW AROUND
THE IDEA OF A WINTER STORM WATCH FOR THE NW HALF...BUT DECIDED
AGAINST IT GIVEN SOME DETAILS IN QPF AND PLACEMENT OF FORCING THAT
NEED TO BE IRONED OUT. HOWEVER...WINTER WX ADVISORY CRITERIA SHOULD
BE MET. HAVE OPTED TO ISSUE A SPECIAL WX STATEMENT AT THIS TIME TO
HIGHLIGHT THE POTENTIAL...BUT ALSO NOTE THE UNCERTAINTY IN AMOUNTS.
MAIN IMPACTS WILL BE RATHER SLUSHY ROADS IN THE AFTERNOON FOLLOWED
BY BLOWING AND DRIFTING OF THE SNOW OVERNIGHT AS SNOW RATIOS
INCREASE.
TUESDAY THROUGH WEDNESDAY NIGHT...WEAK MID-LEVEL RIDGING...LOW-LEVEL
WAA AND INVERSION HEIGHTS FALLING BELOW 3KFT WILL PUT A QUICK END TO
THE LES FROM WEST TO EAST THROUGHOUT THE DAY. A CLIPPER SHORTWAVE
WILL TRACK SE INTO THE UPPER MS VALLEY LATE TUESDAY. THE SHORTWAVE
LOOKS TO GET CAUGHT UP IN A LARGER-SCALE TROUGH OVER HUDSON
BAY...ULTIMATELY SLOWING ITS PROGRESSING AND SHIFTING IT TO A ENE
TRACK. WHERE THIS TAKES PLACE WILL BE CRUCIAL FOR DETERMINING SNOW
PROBABILITY/AMOUNTS FOR THE CWA. THE GFS IS THE FASTEST...BRINGING
WIDESPREAD ACCUMULATING SNOW TO THE AREA LATE TUESDAY NIGHT INTO
WEDNESDAY AFTERNOON. THE ECMWF TAKES AN INITIALLY MORE AGGRESSIVE
EVOLUTION...RESULTING THE THE TROUGH DIGGING FARTHER SOUTHEAST
BEFORE PIVOTING ACROSS SOUTHERN LAKE/LOWER MI. WITH THIS
SCENARIO...MOST OF THE SNOW HOLDS OFF UNTIL WEDNESDAY NIGHT. THE GEM
FOLLOWS A SOLUTION IN THE MIDDLE...BUT LEANS MORE IN LINE WITH THE
GFS. ATTM...CANNOT REALLY PIN DOWN AMOUNTS AND EXACT TIMING...THOUGH
THE PROSPECTS FOR SEVERAL INCHES OF ACCUMULATING SNOW SOMETIME LATE
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT ARE GROWING.
THANKSGIVING...DEPENDING ON WHAT MODEL SOLUTION PANS
OUT...WIDESPREAD SNOW MAY LINGER THROUGH THE MORNING OR END BEFORE
DAYBREAK. EITHER WAY...CAA BEHIND THE CLIPPER SHOULD YIELD LES FOR
THE N/NNW WIND BELTS DURING THE DAY. IT STILL LOOKS COLD...WITH
TEMPS MORE IN LINE WITH CHRISTMAS RATHER THAN THANKSGIVING.
HOWEVER...WITH THE SLOWER SOLUTION...THE ECMWF HAS A HARDER TIME
BRINGING THE COLDEST AIR INTO THE REGION.
FRIDAY AND SATURDAY...LONG RANGE MODELS HAVE BACKED OFF SOMEWHERE ON
A TRANSITION TO A MORE ZONAL AND MILD PATTERN BEGINNING FRIDAY AND
DELAY IT UNTIL LATE IN THE WEEKEND. THE OVERALL PATTERN LOOKS QUIET
BESIDE SOME LES FOR THE WNW WIND SNOW BELTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1244 PM EST SAT NOV 22 2014
LOW CLOUDS ARE THE MAIN FORECAST ISSUE INTO SUNDAY. ALTHOUGH THERE
WERE SOME BREAKS IN THE OVERECAST IN DOWNSLOPE AREAS IN CNTRL UPPER
MI EXPECT MVFR CIGS TO PERSIST AT THE TAF SITES THIS AFTERNOON.
CONTINUING MOISTURE FLOWING INTO THE AREA SHOULD RESULT IN LOWERING
OF CIGS TONIGHT. BASED ON UPSTREAM CIGS THIS MORNING OVER
IA/MN/WI...EXPECT CIGS TO FALL TO IFR LATE TONIGHT...OR EVEN
LIFR...AS THE MOIST LOW-LEVELS WILL BE ONLY BE ADDED TO BY
ADDITIONAL MOISTURE AND HELPED ALONG BY DEVELOPING UPSLOPE FLOW AT
KCMX AND KSAW. AT THESE SITES....PROBABLY WILL SEE DRIZZLE AND FOG
AS WELL WITH VSBY LIKELY REACHING IFR LATE TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EST SAT NOV 22 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL MOVE
TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL INCREASE TO
GALES 40-45 KTS MONDAY AFTN INTO MONDAY NIGHT. WINDS DIMINISH TO 25
KTS OR LESS LATER TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS
ON THURSDAY AS COLD AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE
BUILDING OVER THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE
LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ248>250-265-266.
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ242>245-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
421 PM EST SAT NOV 22 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 420 PM EST SAT NOV 22 2014
WV IMAGERY AND RUC ANALYSIS INDICATED ZONAL FLOW ACROSS THE NRN
CONUS WITH A STRONG 170 KNOT 250 MB JET MOVING INTO THE PAC NW. A
SHORTWAVE TROUGH WAS MOVING THROUGH SRN SASK AND NRN MT. A VIGOROUS
SRN SHORTWAVE TROUGH WAS LOCATED OVER WRN TEXAS. AT THE SFC...SRLY
FLOW PREVAILED FROM THE GULF TOWARD THE UPPER MS VALLEY AND NRN
LAKES BTWN HIGH PRES OVER THE MID ATLANTIC AND A 984 MB LOW INTO SRN
SASK. WAA HAS PUSHED TEMPS INTO THE MID AND UPPER 30S ACROSS UPPER
MI. ALTHOUGH THE LOW LEVEL MOISTURE THINNED OUT ENOUGH FOR SOME
SUNSHINE THIS AFTERNOON...ESPECIALLY IN DOWNSLOPE LOCATIONS...CLOUDS
OVER NRN WI AND WRN UPPER MI WERE FILLING IN AGAIN ACROSS THE AREA.
TONIGHT...ANY LINGERING DRY LOW LEVEL AIR WILL FILL IN TONIGHT WITH
STRONG LOW LEVEL MOISTURE ADVECTION THIS EVENING. SO...EXPECT BETTER
CHANCES FOR PCPN AS DRIZZLE OR POSSIBLY FREEZING DRIZZLE AS A
SUBSTANTIAL DRY LAYER REMAINS ABOVE 900 MB. SOME FOG WILL BE POSSIBLE
AS WELL AS DEWPOINTS CLIMB TO AROUND FREEZING OR SLIGHTLY ABOVE BY
LATE TONIGHT. EXPECT THE BEST CHANCE FOR DRIZZLE OVER CNTRL UPPER MI
WITH AN UPSLOPE LOW LEVEL WIND COMPONENT SUPPORT...AND OVER THE EAST
CWA WITH ADDED MOISTURE OFF OF LAKE MICHIGAN. TEMPS MAY DROP OFF TO
NEAR FREEZING THIS EVENING AND SLOWLY CLIMB OVERNIGHT.
HOWEVER...SINCE MANY ROAD SURFACES MAY STILL BE BELOW FREEZING...ANY
DRIZZLE THAT FALLS COULD CREATE ICY/SLIPPERY CONDITIONS ON UNTREATED
ROADS.
SUN...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
THE STRONG MOISTURE ADVECTION CONTINUES AND 850-700 MB FGEN
INCREASES. THE GREATEST CHANCE IS EXPECTED OVER THE EAST IN
PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS THE DRY
LAYER FILLS IN ANY DRIZZLE WILL CHANGE OVER TO RAIN BY MID TO LATE
AFTERNOON. TEMPS WILL CLIMB ABOVE NORMAL INTO THE LOW TO MID 40S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 559 AM EST SAT NOV 22 2014
A VERY ACTIVE WEEK IS IN STORE ACROSS THE UPPER GREAT LAKES AS A
POTENT PACIFIC SHORTWAVE DIGS SE AND CARVES OUT A MID-LVL TROUGH
OVER THE PLAINS. THIS WILL BRING A DECENT SURGE OF WARM AIR ACROSS
THE AREA THIS WEEKEND...RESULTING IN ABOVE-AVERAGE TEMPERATURES FOR
A SHORT PERIOD. FORCING AHEAD OF THE ASSOCIATED SFC LOW PRESSURE
SYSTEM WILL ALSO BRING A BATCH OF MODERATE RAIN ACROSS MAINLY
CENTRAL AND EASTERN UPPER MI SUNDAY NIGHT INTO MONDAY. A QUICK
TRANSITION BACK TO WINTER WILL THEN TAKE PLACE ON MONDAY INTO MONDAY
NIGHT AS THE TROUGH AND ASSOCIATED STRONG SURFACE LOW MOVE NORTHEAST
OF THE REGION...BRINGING STRONG CAA AND THE POTENTIAL FOR A MODERATE
TO HEAVY SNOWFALL ACROSS THE WESTERN CWA.
SUN INTO SUNDAY NIGHT...MODELS CONTINUE TO INDICATE LOW PRES RAPIDLY
DEVELOPING OVER THE SRN PLAINS LATE TONIGHT AND SUN IN RESPONSE TO
THE STRONG PACIFIC SHORTWAVE DIGGING INTO THE BASE OF THE SRN STREAM
TROUGH. MEANWHILE...ADDITIONAL ENERGY MOVING OUT OVER THE NRN PLAINS
WILL HELP PULL THIS SYSTEM NORTH AND WITH THE SUBSEQUENT PHASING THE
SFC LOW IS EXPECTED TO RAPIDLY DEEPEN BASICALLY BOMBING OUT INTO THE
970S MB BY THE TIME IT REACHES THE UPPER LAKES MON MORNING. THE
GFS/GEM-NH AND ECMWF ARE NOW ALL IN FAIRLY AGREEMENT SHOWING A SFC
LOW TRACK TOWARD THE MACKINAC STRAITS BY MON MORNING. THE 00Z RUNS
OF THE GEM-NH AND GFS SHOW A DEEPER LOW (IN THE LOW 970S) WHILE THE
ECMWF SHOWS A LOW PRES CENTER IN HIGH 970S. ALL MODELS SUGGEST THAT
PCPN ON THE FRONT SIDE OF THIS SYSTEM WILL BE ALL RAIN FOR UPPER MI
SUNDAY AFTERNOON INTO SUNDAY NIGHT. PCPN WILL LIKELY BE MORE IN THE
FORM OF DRIZZLE SUN MORNING AS SFC-BASED MOIST LAYER STAYS ABOVE
FREEZING WITH DRY AIR ALOFT IN THE DGZ REGION. MODELS FAIRLY
CONSISTENT SHOWING BEST SURGE OF RAIN INTO UPPER MI LATE SUNDAY INTO
SUN NIGHT. COUPLED UPPER JET STRUCTURE SUPPORTING THE RAPID
DEEPENING OF THE SFC LOW AND DEEP LAYER Q-VECT CONVERGENCE WILL
SUPPORT WIDESPREAD RAIN ACROSS THE CWA ON SUNDAY NIGHT. LOOK FOR THE
GREATEST PCPN...PERHAPS MORE THAN ONE INCH...TO OCCUR OVER THE ERN
COUNTIES WHERE THE BEST 850-700 MB MOISTURE TRANSPORT IS EXPECTED
CLOSER TO THE TRACK OF THE SFC LOW.
MON INTO MON NIGHT...AS THE SYSTEM LIFTS NNE AND THE COLUMN COOLS
UNDER FALLING HEIGHTS...MODELS INDICATE DEFORMATION/COMMA HEAD PCPN
SHIELD DEVELOPING. THE FCST CHALLENGE WILL BE DETERMINING THE
STRENGTH AND PERSISTENCE OF THIS DEFORMATION PCPN SHIELD AND WHERE
IT WILL SET UP. 00Z MODELS NOW HINTING THAT BEST DEFORMATION/MOST
PERSISTENT 700 MB FGEN FORCING WILL BE OVER THE WRN COUNTIES WHERE
PCPN WILL BE CHANGING OVER TO SNOW MON MORNING. WITH 850MB TEMPS
COOLING TO AROUND -12C LATE MON...LAKE ENHANCEMENT WILL ALSO COME
INTO PLAY. STILL HAVE THE WRN CWA PEGGED FOR THE POTENTIAL OF
MODERATE TO POTENTIALLY HEAVY SNOW MON INTO MON NIGHT ALONG WITH
BLUSTERY NW WINDS DEVELOPING BEHIND THE SYSTEM AND WILL CONTINUE TO
HIGHLIGHT IN HWO AND EHWO GRIDS. WITH MODEL AVERAGED QPF OF .5-.7
AND SNOW/WATER RATIOS NEAR 10/1 MON MORNING RAISING TO 20/1 LATE MON
NIGHT...HAVE COME UP WITH 24 HR SNOW TOTALS OF 7-9 INCHES OVER SOME
HIGHER TERRAIN LOCATIONS OF WEST FROM KIWD UP TO KCMX. THE SNOW/WIND
WILL SPREAD INTO THE ERN FCST AREA AS WELL...BUT WITH DEFORMATION
PCPN TENDING TO LIFT NE...SNOWFALL WILL LIKELY BE LIGHTER THAN OVER
THE W.
WITH 850MB TEMPS FM -12C TO -14C TUE...NW FLOW LAKE ENHANCEMENT WILL
TRANSITION TO PURE LES AS TROF SHIFTS E AND DEEP MOISTURE DEPARTS.
WITH A TREND TOWARD MORE ANTICYCLONIC FLOW...THERE WILL BE A
DIMINISHING OF NW FLOW LES THRU THE DAY NEAR THE LAKE...BUT WILL
MAINTAIN LIKELY TO CATEGORICAL POPS AT LEAST FOR THE MORNING OVER
THESE AREAS.
HEADING INTO WED/THU...AFTER A BRIEF BREAK FROM THE SNOW TUE NIGHT
...IT LOOKS LIKE THERE MAY BE A POTENTIAL FOR SOME MORE SNOW WED
INTO THANKSGIVING AS MEDIUM RANGE MODELS SHOW INDICATIONS OF A
CLIPPER SHORTWAVE DIVING THROUGH THE MIDWEST/GREAT LAKES REGION.
GFS IS QUITE A BIT QUICKER THAN THE ECMWF/GEM-NH/UKMET WITH THIS
WAVE AND SEEMS TO BE AN OUTLIER AT THIS POINT. THE ECMWF SOLN SHOWS
A BIT DEEPER SYSTEM AND MORE PROLONGED TROFFING INTO THE UPPER GREAT
LAKES WHICH WOULD LIKELY YIELD MORE SNOW. WILL HIGHLIGHT IN EHWO
GRIDS AT LEAST A LIMITED POTENTIAL FOR MODERATE SNOW ALONG THE LAKE
SUPERIOR COUNTIES.
BOTH THE ECMWF AND GEM-NH SHOW RIDGING WORKING IN FROM THE WEST BY
NEXT FRIDAY WHICH SHOULD ALLOW FOR A DIMINISHING TREND TO LES FOR NW
FLOW AREAS ALONG LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1244 PM EST SAT NOV 22 2014
LOW CLOUDS ARE THE MAIN FORECAST ISSUE INTO SUNDAY. ALTHOUGH THERE
WERE SOME BREAKS IN THE OVERECAST IN DOWNSLOPE AREAS IN CNTRL UPPER
MI EXPECT MVFR CIGS TO PERSIST AT THE TAF SITES THIS AFTERNOON.
CONTINUING MOISTURE FLOWING INTO THE AREA SHOULD RESULT IN LOWERING
OF CIGS TONIGHT. BASED ON UPSTREAM CIGS THIS MORNING OVER
IA/MN/WI...EXPECT CIGS TO FALL TO IFR LATE TONIGHT...OR EVEN
LIFR...AS THE MOIST LOW-LEVELS WILL BE ONLY BE ADDED TO BY
ADDITIONAL MOISTURE AND HELPED ALONG BY DEVELOPING UPSLOPE FLOW AT
KCMX AND KSAW. AT THESE SITES....PROBABLY WILL SEE DRIZZLE AND FOG
AS WELL WITH VSBY LIKELY REACHING IFR LATE TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EST SAT NOV 22 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL MOVE
TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL INCREASE TO
GALES 40-45 KTS MONDAY AFTN INTO MONDAY NIGHT. WINDS DIMINISH TO 25
KTS OR LESS LATER TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS
ON THURSDAY AS COLD AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE
BUILDING OVER THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE
LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ248>250-265-266.
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ242>245-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1243 AM EST SAT NOV 22 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 406 PM EST FRI NOV 21 2014
WV IMAGERY AND RUC ANALYSIS INDICATED ZONAL MID/UPPER LEVEL FLOW
THROUGH THE NW AND N CNTRL CONUS WITH A WEAK SHORTWAVE TROUGH OVER
NORTH DAKOTA. A VIGOROUS SRN STREAM SHRTWV WAS SLIDING THROUGH SW
ARIZONA. AT THE SFC...SW FLOW WAS INCREASING FROM THE UPPER MS VALLEY
INTO THE NRN LAKES AS THE PRES GRADIENT TIGHTENS BETWEEN A 995 MB LOW
OVER MANITOBA AND 1034 MB HIGH OVER THE OH VALLEY. WAA INTO THE
REGION HAS BROUGHT AN INCREASE IN MID CLOUDS ACROSS UPPER MI WITH
ANOTHER BATCH UPSTREAM FROM MN INTO CNTRL WI. THE LOWER CLOUDS
REMAINED WELL TO THE SOUTH OVER MO AND SRN IA.
TONIGHT...EXPECT THAT THE STRONG SSW LOW LEVEL WAA PATTERN WILL
RAPIDLY BRING LOW LEVEL MOISTURE TOWARD THE AREA TO SUPPORT LOWER
CLOUDS INTO THE CWA. ALTHOUGH THE LOW LEVEL ISENTROPIC LIFT WILL BE
MARGINAL TO PRODUCE PCPN...UPSLOPE FLOW INTO MUCH OF THE AREA SHOULD
BE ENOUGH TO SUPPORT SOME LIGHT PCPN...ESPECIALLY OVER THE EAST HALF
WHERE ADDITIONAL MOISTURE FROM LAKE MICHIGAN IS AVAILABLE. MODEL
SOUNDINGS SUGGEST THAT THE 3K-8K DRY/WARM LAYER WILL BE STRONG ENOUGH
TO LIMIT/PREVENT ICE CRYSTAL AVAILABILITY INTO THE LOWER MOIST LAYER.
SO...EXPECT -FZDZ WILL BE THE PREDOMINANT PCPN TYPE. EVEN THOUGH
LITTLE IF ANY MEASURABLE PCPN IS EXPECTED...EVEN A VERY THIN COATING
OF -FZDZ COULD RESULT IN HAZARDOUS CONDITIONS ON UNTREATED ROADS.
SAT...THE COMBINATION OF DAYTIME HEATING AND ADDITIONAL WAA WILL
PUSH TEMPS ABOVE FREEZING IN MOST AREAS BY NOON CHANGING ANY
LINGERING FREEZING DRIZZLE TO DRIZZLE. EXPECT THE PCPN CHANCES TO
DIMINISH AS THE LOW LEVEL WAA WEAKENS DURING THE LATE MORNING AND
AFTERNOON. OTHERWISE...TEMPS SHOULD CLIMB TO READINGS AT OR ABOVE
NORMAL IN THE MID TO UPPER 30S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 430 PM EST FRI NOV 21 2014
A VERY ACTIVE WEEK IS IN STORE ACROSS THE UPPER GREAT LAKES AS A
POTENT MID-LEVEL SYSTEM DIGS INTO THE NORTHERN ROCKIES/PLAINS. THIS
WILL BRING A DECENT SURGE OF WARM AIR ACROSS THE AREA BY LATE
WEEKEND...BRINGING THE AREA BACK INTO ABOVE-AVERAGE TEMPERATURES FOR
A SHORT PERIOD. WITH THIS WILL COME A DECENT ROUND OF RAIN ACROSS
MAINLY CENTRAL AND EASTERN UPPER MI SUNDAY NIGHT INTO MONDAY. A
QUICK TRANSITION BACK TO WINTER WILL THEN TAKE PLACE ON MONDAY AS
THE TROUGH AND ASSOCIATED STRONG SURFACE LOW MOVE NORTHEAST OF THE
REGION...BRINGING STRONG CAA AND THE POTENTIAL FOR A DECENT SNOWFALL
ACROSS THE WESTERN CWA.
SATURDAY NIGHT...AS WEAK MID-LEVEL RIDGING WORKS ACROSS THE UPPER
GREAT LAKES...THIS LOOKS TO BE THE QUIETEST PERIOD THROUGH AT LEAST
TUESDAY. SIGNIFICANTLY DRY AIR ABOVE 900 HPA AND THE LACK OF ANY
APPRECIABLE MID/UPPER-LEVEL FORCING SHOULD LIMIT ANY DEEPER PRECIP
POTENTIAL. THE ONLY CONCERN IS A CHANCE FOR DZ/FZDZ ASSOCIATED WITH
WEAK LOW-LEVEL WAA SOUTH LATE IN THE NIGHT.
SUNDAY AND MONDAY...SIGNIFICANT CHANGES ARE SET TO BEGIN SUNDAY AS
AN ACTIVE NORTHERN AND SOUTHERN STREAM TAKE AIM ON THE UPPER GREAT
LAKES. FIRST...A LOOK AT THE LARGE SCALE PICTURE. AS THE
AFOREMENTIONED TROUGH OVER THE NORTHERN ROCKIES TRACKS ESE TOWARD
THE UPPER MS VALLEY...ANOTHER TROUGH ACROSS TX SATURDAY EVENING WILL
EJECT NE INTO THE UPPER GREAT LAKES. THE MERGING PIECES OF ENERGY
COMBINED WITH A QUICKLY DEVELOPING 120KT UPPER JET STREAK WILL
INDUCE A SFC LOW SOMEWHERE FROM EASTERN UPPER MI TO NORTHERN LOWER
MI BY 12Z MONDAY.
UPPER MI FINDS ITSELF CAUGHT IN A CONVOLUTED PATTERN SUNDAY MORNING
BEFORE THE TWO SYSTEMS CONSOLIDATE OVER THE AREA. OVERALL SYNOPTIC
FORCING REMAINS LIMITED TO START THE DAY...BUT LOW-LEVEL MOISTURE
TRANSPORT RESULTING IN A DEEPENING MOIST LAYER WILL ALLOW FOR
INCREASING CHANCES OF FZDZ/DZ IN THE MORNING...AND RAIN THROUGHOUT
THE AFTERNOON. BEST CHANCES DURING THE DAY LOOK TO BE ACROSS THE
CENTRAL AND EASTERN CWA WITH UPSLOPE AND MOISTURE INFLUENCES FROM SE
WINDS OFF LAKE MI. TEMPS THROUGH THE MOIST LAYER WILL REMAIN WARM
ENOUGH FOR SUPER-COOLED LIQUID...INTRODUCING CONTINUED CONCERN FOR
FZDZ/FZRA IN THE MORNING. GIVEN OUR RECENT SUB-FREEZING
STRETCH...CLEARED ROADS MAY SEE SOME ICING EVEN AS TEMPS WARM INTO
THE 30S TO LOW 40S DURING THE DAY SUNDAY. LATEST MDOT ROAD SENSORS
ARE SHOWING SUB-FREEZING TEMPS DOWN AT LEAST 24 INCHES BELOW THE
ROAD AND SUB-20F TEMPS DOWN TO AT LEAST 6 INCHES FOR NEARLY ALL
UPPER MI HIGHWAYS. WILL THEREFORE EXTEND THE FZDZ/FZRA POTENTIAL
THROUGH SUNDAY MORNING UNTIL AIR TEMPS WARM WELL-ABOVE FREEZING
SUNDAY AFTERNOON.
SIGNIFICANT MOISTURE TRANSPORT/ISENTROPIC LIFT WILL FOCUS ACROSS THE
EAST HALF OF THE CWA LATE SUNDAY AFTERNOON THROUGH MUCH OF THE
NIGHT. MEANWHILE...DECENT LIFT UNDER THE RIGHT ENTRANCE OF THE UPPER
JET WILL SPREAD ACROSS THE AREA. THIS SHOULD BRING WIDESPREAD PRECIP
OVER THE ENTIRE CWA THROUGHOUT THE NIGHT. WARMING TEMPS THROUGHOUT
THE COLUMN WILL RESULT IN A PTYPE OF ALL RAIN FOR THE ENTIRE CWA
SUNDAY AFTERNOON AND EVENING...AND ALL BUT THE WESTERN CWA LATE
SUNDAY NIGHT. WITH THE DECENT FORCING AND SUFFICIENT
MOISTURE...RAINFALL AMOUNTS LATE SUNDAY AFTERNOON THROUGH MONDAY
MORNING ARE EXPECTED TO SURPASS 0.75IN ACROSS THE EAST HALF. THIS
MAY BE A LITTLE CONSERVATIVE...BUT WOULD LIKE TO SEE BETTER
MID-LEVEL SUPPORT IN CONJUNCTION WITH THE UPPER JET BEFORE
INCREASING PRECIP AMOUNTS ANY FURTHER.
LATE SUNDAY NIGHT INTO MONDAY STARTS THE TRANSITION BACK TO SNOW AS
THE SFC LOW REACHES EASTERN UPPER MI LATE SUNDAY NIGHT. AS THE
SOUTHERN AND NORTHERN STREAM MERGE...THE NEW DEEPER TROUGH NEARLY
STALLS OVER THE UPPER GREAT LAKES. AN IMPRESSIVE 140KT UPPER JET
OVER THE MID MS VALLEY COMBINED WITH THE DEPARTING 120KT JET MOVING
OVER QUEBEC WILL BE ENOUGH TO KEEP A DEEPER SFC LOW OVER
ONTARIO/QUEBEC. MEANWHILE...A COMPACT TROUGH NEAR SEATTLE SUNDAY
AFTERNOON WILL DIG INTO THE DEPARTING THE TROUGH...FURTHER SLOWING
ITS MOVEMENT. ALL OF THIS COMES TOGETHER TO PRODUCE A LAGGING
LOW-LEVEL TROUGH AND DEFORMATION ZONE OVER UPPER MI ON MONDAY AND
MONDAY NIGHT. WITH LAKE ENHANCEMENT KICKING IN WITH N/NNW
WINDS...THERE IS INCREASING POTENTIAL FOR MODERATE TO POSSIBLY HEAVY
SNOW ACROSS THE NORTHWEST HALF OF UPPER MI. THE 12Z NAM AND 12Z GFS
HAVE BOTH COME IN WITH MUCH HIGHER QPF ACROSS THE WESTERN AND
CENTRAL CWA ON MONDAY. THOUGH THE ECMWF TAKES THE LOW ACROSS
NORTHERN LOWER MI...THE MID/UPPER-LEVEL SUPPORT PAINTS HIGHER QPF
AMOUNTS ACROSS THE WESTERN CWA AS WELL. THE TRANSITION TO SNOW
SHOULD BE UNDERWAY ACROSS THE FAR WEST BY DAYBREAK MONDAY...THEN
CONTINUE PRESSING EASTWARD. BY EARLY AFTERNOON...ALL BUT SOME OF THE
SHORELINE LOCATIONS OF THE WEST HALF SHOULD CHANGE OVER TO SNOW.
WHILE THERE IS SOME UNCERTAINTY IN HOW QUICK SNOW RATIOS INCREASE
DURING THE DAY...SEVERAL INCHES OF SNOW SHOULD FALL FOR MOST OF THE
NW HALF OF THE CWA MONDAY AFTERNOON. DO NOT WANT TO COMPLETELY JUMP
ON BOARD WITH THE NEW GUIDANCE QUITE YET...BUT THERE IS ENOUGH
EVIDENCE TO AT LEAST INCREASE SNOW AMOUNTS A BIT. THE EASTERN CWA
SHOULD SEE AT LEAST SOME ACCUMULATIONS...BUT A LATER TRANSITION TO
ALL SNOW COMBINED WITH A LESS FAVORABLE LOCATION OF THE FORCING WILL
KEEP AMOUNTS LOWER. WILL NEED TO MONITOR THIS OVER THE NEXT COUPLE
DAYS AS AT LEAST SOME WINTER WX HEADLINES MAY BE NEEDED.
MONDAY NIGHT AND TUESDAY...MOISTURE CONTINUING TO WRAP AROUND
THE BACKSIDE OF THE DEPARTING LOW COMBINED WITH UPSLOPE AND LAKE
INFLUENCE WILL GENERATE SNOW FOR THE N TO NNW WIND SNOW BELTS.
ANOTHER SEVERAL INCHES OF SNOW WILL BE POSSIBLE MONDAY NIGHT. BY
TUESDAY...SOME DRIER AIR WILL BEGIN TO WORK IN FROM THE WEST AS
INVERSION HEIGHTS FALL BELOW 5KFT...CUTTING OFF MUCH OF THE RESIDUAL
LAKE EFFECT PRECIP.
WEDNESDAY THROUGH FRIDAY...ANOTHER TROUGH DIGGING OUT OF
NORTH-CENTRAL CANADA WILL MOVE SE ACROSS THE UPPER GREAT LAKES
TUESDAY NIGHT INTO WEDNESDAY. ACCUMULATING SNOW WILL BE POSSIBLE
WEDNESDAY WITH THIS SYSTEM...BUT ITS TRACK AND STRENGTH ARE TOO
VARIABLE IN THE MODELS TO PIN DOWN LOCATIONS AT THIS TIME. MUCH
COLDER AIR ARRIVES BEHIND THE LOW AND INDUCES LES FOR THE NNW WIND
SNOW BELTS WEDNESDAY NIGHT THROUGH THANKSGIVING. A SLOWLY MODERATING
850 HPA AIRMASS WITH TEMPS -15 TO -20C WILL RESULT IN THE WEATHER
FEELING MORE LIKE CHRISTMAS THAN THANKSGIVING AS HIGHS STRUGGLE TO
GET OUT OF THE TEENS FOR AT LEAST THE WEST AND CENTRAL. BY
FRIDAY...ANOTHER PATTERN CHANGE WILL BRING MODERATING CONDITIONS TO
END THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1243 AM EST SAT NOV 22 2014
LLWS IS EXPECTED AS THE LOW LEVEL JET REALLY INCREASES 1-2KFT ABOVE
THE SURFACE...ESPECIALLY AT KSAW OVERNIGHT. HAVE LEFT GUSTS UP TO
ACCOUNT FOR THIS. MVFR CLOUDS WILL BE PUSHING NORTH-NORTHEAST INTO
THE AREA TONIGHT. THIS WILL LEAD TO A QUICK DROP IN CEILINGS LATE
TONIGHT...WITH KSAW HAVING THE LOWEST VALUES THAT SHOULD FALL INTO
THE IFR RANGE LATE. WITH THESE LOW CLOUDS...THERE IS THE POTENTIAL
FOR LIGHT FREEZING DRIZZLE LATE TONIGHT...ESPECIALLY AT KSAW.
CURRENT SFC DEWPOINT DEPRESSIONS REMAIN HIGH THOUGH AT 10-15F...SO
WILL NOT MENTION FZDZ ATTM. CONDITIONS AT ALL SITES ON SAT WILL BE
LOW MVFR OR IFR AT ALL SITES AS LOW CLOUDS REMAIN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EST FRI NOV 21 2014
WINDS WILL CONTINUE TO INCREASE WITH A TIGHT PRES GRADIENT BETWEEN
LOW PRES OVER THE PLAINS AND A RIDGE OVER THE OH VALLEY.
WINDS TOT 30KTS WITH FREQUENT GALE FORCE GUSTS TO 35 KNOTS ARE
EXPECTED TONIGHT. THE PRESSURE GRADIENT WILL DECREASE SATURDAY INTO
SATURDAY NIGHT AS A TROUGH TRAILING THE CANADIAN LOW DROPS SOUTHEAST
OVER LAKE SUPERIOR. A DEVELOPING LOW IN THE CENTRAL/SOUTHERN PLAINS
ON SATURDAY NIGHT WILL LIFT NORTHEAST THROUGH THE GREAT LAKES REGION
TO NEAR THE STRAITS MONDAY MORNING AT AROUND 28.9 INCHES. AS THE LOW
LIFTS TO THE NORTHEAST ON MONDAY NORTHERLY GALES ARE LIKELY WHICH
COULD PERSIST THROUGH MONDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
263-264-266-267.
LAKE MICHIGAN...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LMZ248.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...07/JLA
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
353 PM CST SAT NOV 22 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 238 PM CST SAT NOV 22 2014
MAIN CONCERN DURING THE SHORT TERM PERIOD IS THE TREND OF STRATUS
AND THE POTENTIAL EXTENT OF FOG TONIGHT. A SECONDARY CONCERN IS WITH
PRECIP POTENTIAL TONIGHT INTO SUNDAY...THOUGH MODELS CONTINUE TO
SHOW PRECIP AMOUNTS BEING PRETTY UNDERWHELMING THROUGH SUNDAY ACROSS
THE ENTIRE MPX AREA...WITH DEEPER MOISTURE GOING ACROSS ERN WI AND
MICHIGAN.
EXTENSIVE STRATUS ACROSS ALL BUT THE NW PORTION OF THE MPX CWA HAS
HELD TEMPERATURES IN CHECK ALL DAY. LOOKING TO THE SOUTH...THERE ARE
A COUPLE OF MOISTURE SURGES HEADING OUR WAY. THE FIRST IS QUICKLY
MOVING INTO NRN IA AND WILL LIKELY BE TO THE I-90 CORRIDOR BY 00Z
THIS EVENING. IT IS CHARACTERIZED BY DEWPS IN THE 40S AND MORE
CONCERNING FOR THE CLOUD FORECAST TONIGHT...CLEAR SKIES. THE SECOND
MOISTURE SURGE IS JUST NOW GETTING TO I-80 AND IT IS ASSOCIATED WITH
DEWPS IN THE 50S...AND A RETURN TO LIFR STRATUS AND FOG. THE
ECMWF/GEM SHOW THIS SECOND MOISTURE SURGE AND ITS ASSOCIATED LOWER
50 DEWPS GETTING CLEAR UP TO I-90 SUNDAY MORNING BEFORE GETTING
SHUNTED OFF TO THE EAST. CERTAINLY DEWPS IN THE 40S WITH SNOW ON THE
GROUND FAVORS STRATUS CONTINUING THROUGH THE NIGHT AND THE CURRENT
FORECAST CERTAINLY READS THAT WAY...BUT WE WILL HAVE WATCH HOW THAT
CLEARING EVOLVES.
FOR FOG...ONE THING WE ARE POSITIVE ABOUT IS IT WILL BE HAZY TROUGH
THE NIGHT GIVEN DEWPS ABOVE FREEZING WITH SNOW ON THE GROUND. THERE
WAS TALK OF A DENSE FOG ADVISORY...BUT NOT CONFIDENT ENOUGH ON WHERE
TO PUT ONE OTHER THAN ANYONE UNDER STRATUS NOW...WHICH IS JUST ABOUT
OUR ENTIRE CWA AND DID NOT WANT TO ISSUE SUCH A LARGE ADVY AT THIS
POINT. ON TOP OF THAT...WE WILL BE MAINTAINING 8-12 KT WINDS THROUGH
THE NIGHT...SO THAT WILL SUPPLY A CERTAIN DEGREE OF MIXING AS WELL.
NOT TO MENTION WE HAVE THAT CLEARING RACING NORTH OUT OF IA. AT THIS
POINT...HIGHEST CONFIDENCE IN DENSE FOG IS WHERE OUR DEEPEST SNOW
RESIDES ACROSS THE NRN MPX CWA. THE HRRR WOULD SUPPORT THIS IDEA AS
IT DOES SHOW VSBYS IMPROVING THROUGH THE NIGHT ACROSS SRN MN AS THAT
SLUG OF SLIGHTLY DRIER AIR ACROSS IA WORKS INTO MN.
FOR TEMPERATURES...THEY MAY GO NOTHING BUT UP THROUGH THE NIGHT.
FIRST RUN OF THE HOURLY TEMPERATURE TOOL WITH THE LOCAL SUPERBLEND
BROUGHT A TEMPERATURE OF 53 TO ALBERT LEA BY 7Z TONIGHT. DID NOT GO
QUITE THAT AGGRESSIVE...BUT DO THINK MUCH OF THE AREA EAST OF A NEW
ULM TO MORA LINE WILL RISE INTO THE 40S OVERNIGHT. GIVEN THE MILD
START...ALSO GAVE HIGHS SUNDAY A BIT OF AN UPWARD NUDGE TO ABOUT A
50/50 BLEND BETWEEN THE PREVIOUS FORECAST AND THE 22.12 GEM/ECMWF.
THE GEM/ECMWF SHOW HIGHS IN THE LOW 50S FOR SE MN/WRN WI TOMORROW.
GIVEN THE EXTENSIVE CLOUD COVER...DO NOT THINK WE WILL GET THAT
HIGH...BUT DO HAVE HIGHS INTO THE MID/UPPER 40S FOR ALL BUT WRN AND
CENTRAL MN.
FOR PRECIP...THAT CONTINUES TO LOOK UNDERWHELMING. OUR BIGGEST
PROBLEM THROUGH TONIGHT CONTINUES TO BE THE FACT THAT THE ATMO CAN
NOT TAKE ON MUCH MORE MOISTURE BELOW 900 MB...BUT ABOVE THAT...ITS
BONE DRY. CONTINUED TO RUN WITH HIGHEST POPS SUNDAY OUT IN ERN AREAS
AS THEY WILL BE CLOSER TO THE H85 MOISTURE TRANSPORT...BUT LIKING
THE IDEA THE GFS/SREF/NMM/ARW SHOW OF A NARROW BAND OF RAIN CENTERED
ON FGEN IN THE H7-H6 LAYER COMING OUT OF SODAK TONIGHT AND WORKING
ACROSS SRN MN THROUGH SUNDAY MORNING. THE 22.18 HOPWRF MEMBERS ALSO
SHOW THIS BAND OF PRECIP BY 9Z /THE END OF THOSE RUNS/ MOVING INTO
THE WRN PORTION OF THE FSD FORECAST AREA...SIMILAR TO WHAT THE
MODELS MENTIONED ABOVE SHOW. DID BOOST POPS IN SW MN INTO THE HIGH
CHANCE CATEGORY SUNDAY MORNING FOR NOW. THIS MAY VERY WILL END UP
BEING THE BEST CHANCE AT SEEING MEASURABLE PRECIP WITH THIS SYSTEM
FOR MUCH OF OUR MN FORECAST AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 238 PM CST SAT NOV 22 2014
SUNDAY NIGHT THROUGH MONDAY WILL BRING A PERIOD OF STRONG WINDS
AND LIGHT PRECIPITATION TO THE FORECAST AREA...IN THE WAKE OF A
DEEPENING MID LATITUDE CYCLONE. THE STRONGEST WINDS ARE EXPECTED
ACROSS THE WESTERN FORECAST AREA AND THE HIGHEST POTENTIAL FOR
ACCUMULATING SNOW REMAINS ACROSS FAR EASTERN MN...BUT ESPECIALLY
IN WEST CENTRAL WI.
BY 00Z MONDAY...RAPID CYCLOGENESIS WILL BE ONGOING IN THE MID
MISSISSIPPI RIVER VALLEY IN RESPONSE TO A DEEP TROUGH DIGGING IN
ACROSS THE CENTRAL CONUS AND A LARGE AREA OF 120-150M 500MB 12-HR
HEIGHTS FALLS MOVING ACROSS THE AREA. THE AMOUNT OF DEEPENING IS
STILL QUITE VARIABLE DEPENDING ON WHICH 12Z SOLUTION ONE CHOOSES TO
FOLLOW. THE 22.12Z GFS IS BY FAR AND AWAY THE MOST AGGRESSIVE IN
STRENGTHENING THE LOW OVER THE SOUTHERN HALF OF LAKE MICHIGAN BY
06Z MONDAY TO 975MB...969MB OVER NORTHERN MICHIGAN BY 12Z...AND
966MB AS IT MOVES NORTH OF THE GREAT LAKES BY 18Z. THE NAM AND
ECMWF SEEM MORE REASONABLE WITH A BIT MORE MODEST DEEPENING.
TYPICALLY...THE KIND OF DEEPENING THE GFS IS SHOWING ONLY OCCURS
WITH VERY STRONG BAROCLINICITY AND/OR A NEGATIVELY TILTED UPPER
TROUGH. WE REALLY DON`T HAVE EITHER. THERE IS STRONG COLD
ADVECTION AND A DECENT TEMPERATURE GRADIENT ACROSS THE MID/UPPER
MISSISSIPPI VALLEY...BUT THEY SEEM MORE IN LINE WITH THE NAM/ECMWF
THAT ARE BIT MORE PROGRESSIVE WITH THE LOW AND NOT AS WOUND UP.
THEREFORE...WE DID NOT JUMP ON THE GFS SNOWFALL FORECAST THAT
WOULD GIVE 6-8" TO PORTIONS OF WEST CENTRAL WI. WE THINK THE
HEAVIEST PRECIP SHOULD BE EAST OF THE FORECAST AREA AND THE
DYNAMIC COOLING ON THE BACK SIDE OF THE LOW WILL BE WEAKER THAN
THE GFS INDICATES. IT IS NOTABLE THAT THE 22.15Z SREF AND GEM ALSO
SHOW THE POTENTIAL FOR SEVERAL INCHES OF SNOW NEAR OR JUST EAST OF
THE FORECAST AREA. THIS IS SOMETHING TO FOLLOW OVER THE NEXT 12-18
HOURS...BUT WE SIMPLY DIDN`T HAVE ENOUGH CONFIDENCE TO ISSUE A
WINTER STORM WATCH AT THIS POINT. FURTHERMORE...EVEN WITH THE
EXPECTED STRONG WINDS...THE WARM TODAY HAS LIKELY LIMITED THE
AMOUNT OF SNOW AVAILABLE FOR BLOWING AND DRIFTING. THERE WERE A
LOT OF HIGHS IN THE UPPER 30S AND LOWER 40S IN WESTERN MN TODAY.
THE NEXT SYSTEM TO WATCH ARRIVES ON WEDNESDAY AND THERE IS AGAIN
SIGNIFICANT DIFFERENCES BETWEEN THE GFS AND ECMWF. THE ECMWF HAS A
POTENT CLIPPER SYSTEM WITH 1-4" OF SNOW...IMPRESSIVE COLD
ADVECTION AND A TIGHT PRESSURE GRADIENT ON THE BACK SIDE OF THE
SYSTEM. THE 22.12Z ECMWF HAS SUSTAINED 25-30KTS NEAR THE ND/SD/MN
BORDER EARLY WEDNESDAY MORNING - QUITE IMPRESSIVE GIVEN ITS
COARSER RESOLUTION. THE GFS HAS A WEAK SURFACE TROUGH AND MUCH
LESS LIFT. THIS MID WEEK SYSTEM PRETTY MUCH LOCKS IN OUR CHANCE
FOR A WELL BELOW NORMAL THANKSGIVING. IT LOOKS VERY COLD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1148 AM CST SAT NOV 22 2014
IFR AND LOWER STRATUS CONTINUES TO SLOWLY CRAWL NW ACROSS
MN...STILL QUESTIONABLE WHETHER OR NOT IT REACHES AXN...BUT WITH
12Z TAF HAVING IT GETTING THERE...KEPT THAT TREND GOING. THESE
CIGS WILL ONLY MARGINALLY IMPROVE THROUGH THE AFTERNOON...LIKELY
JUST GOING FROM LIFR TO IFR BEFORE GOING BACK TO LIFR TONIGHT.
GIVEN CONTINUED SOUTH WINDS AND INCREASING MOISTURE OVER THE SNOW
THROUGH THE NIGHT...KEPT THE TREND FOR FG TONIGHT FROM 12Z TAFS
GOING. UNCERTAINTY STARTS TO INCREASE TOMORROW WITH THE POTENTIAL
FOR CIGS TO QUICKLY GO VFR. FOR NOW...TIMED IMPROVEMENT IN CIGS TO
WHEN WINDS ARE FORECAST TO SWING AROUND TO 240 DEGS OR GREATER.
SREF MVFR CIG PROBABILITY DROPS TO NEAR ZERO SUNDAY MORNING OUT
WEST...SO WE COULD VERY WELL SEE CIGS IMPROVE FASTER THAN
CURRENTLY INDICATED ACROSS MN. FOR PRECIP...LOOKING LIKE OUR BEST
CHANCE THIS TAF PERIOD WILL BE WITH A NARROW BAND OF RAIN THE
NMM/ARW/GFS/SREF SHOW COMING OUT OF SODAK LATE TONIGHT AND WORKING
ACROSS MN DURING THE MORNING.
KMSP...CONFIDENCE IS HIGH IN MINIMAL IMPROVEMENTS TO CIGS/VIS
THROUGH THE DAY. CONTINUED MOIST SRLY FLOW WILL ALSO LEAD TO A
LOWERING IN CONDITIONS TONIGHT...THOUGH THERE IS LESS CONFIDENCE
IN THE TIMING ON WHEN CIGS DROP BACK BELOW 005. 50/50 CONFIDENCE
ON THE FOG TEMPO GROUP...BUT WITH IT ALREADY IN THE TAF...LEFT IT
THERE. CONFIDENCE IS CONSIDERABLY LOWER THIS FAR OUT WITH
IMPROVEMENTS IN THE TAF BY SUNDAY AFTERNOON...BUT FOLLOWED THE
IDEA OF THE NAM/SREF ON THAT FOR NOW.
/OUTLOOK FOR KMSP/
MON...MVFR/IFR CIGS CHC -SN. WINDS NW 20G30 KT.
TUE...VFR. WINDS W 5-10 KT.
WED...MVFR/IFR CHC -SN. WINDS NW 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1245 PM CST SAT NOV 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM CST SAT NOV 22 2014
WARM AIR ADVECTION REGIME IS THE MAIN STORY OF THE SHORT TERM
PERIOD. BRISK SOUTHERLY WINDS HAVE ALLOWED TEMPERATURES TO CLIMB
ABOVE FREEZING /FOR THE FIRST TIME IN NEARLY TWO WEEKS/ OVERNIGHT
ACROSS SOUTHERN MN AND WESTERN WI. SURFACE DEW POINTS IN THE LOW
TO MID 30S CONTINUE TO PUSH NORTHWARD THROUGH IOWA AND WILL
CONTINUE FILLING IN ACROSS EASTERN MN AND WESTERN WI. WENT WITH A
PESSIMISTIC CLOUD/FOG FORECAST COMPARED TO MUCH OF THE GUIDANCE
WITH THE RELATIVE WARM AND MOIST AIR STREAMING NORTHWARD OVER THE
CURRENT SNOW PACK. DEW POINTS ACROSS WESTERN MN WILL LIKELY REMAIN
BELOW FREEZING THROUGH THE DAY AS THE BEST MOISTURE ADVECTION
STREAMING NORTHWARD TAKES AN EASTWARD TURN. MUCH OF SOUTHEASTERN
MN AND WESTERN WI ARE CURRENTLY SOCKED IN WITH LOW STRATUS AND
FOG...BUT MOSTLY CLEAR SKIES CAN BE FOUND TO THE WEST. THE HRRR
HAS PERFORMED WELL WITH THE COVERAGE OF THE CLOUDS/FOG...SO
WEIGHTED HEAVILY WITH THE HRRR IN THE SHORT RANGE FORECAST. THE
STRATUS DECK IS EXPECTED TO EXPAND SOME TO THE WEST THROUGH THE
MORNING...AND KEEP EASTERN MN AND WESTERN WI SOCKED IN THROUGH THE
DAY.
A COMPLICATED EVOLUTION OF THE FORECAST FOR TONIGHT THROUGH EARLY
SUNDAY MORNING. A NORTHERN STREAM SHORTWAVE WILL MOVE ACROSS
SOUTHERN CANADA TODAY AND MAKE IT TO MANITOBA TONIGHT.
MEANWHILE...THE SOUTHERN STREAM WAVE WILL BE PIVOTING OVER THE
SOUTHERN CONUS. THE BEST AREA OF LIFT WILL LARGELY REMAIN SOUTH OF
OUR AREA TONIGHT...BUT SOME MARGINAL LIFT ARRIVES TONIGHT AND WITH
SATURATED LOW LEVELS...DRIZZLE/LIGHT RAIN WILL BE POSSIBLE ACROSS
EASTERN MN AND WESTERN WI. WITH MODEL SOUNDINGS ALSO INDICATING A
VERY SATURATED NEAR SURFACE ENVIRONMENT...EXPANDED MENTION OF FOG IN
THE FORECAST...ESPECIALLY FOR WESTERN WI.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM CST SAT NOV 22 2014
A MILD START TO THE LONG TERM PERIOD PRIOR TO THE MERGING OF
NORTHERN AND SOUTHERN STREAM WAVES...AND THEN ANOTHER SURGE OF
ARCTIC AIR BLASTS THE REGION.
00Z MODEL SOLUTIONS WERE FAIRLY SIMILAR IN THEIR DEPICTION OF POPS
FOR SUNDAY...WITH THE FORECAST AREA BEING SOMEWHAT CAUGHT BETWEEN
THE TWO MAIN AREAS OF FORCING ASSOCIATED WITH THE AFOREMENTIONED
WAVES. THIS WILL MEAN SUNDAY WILL BE A FOGGY DAY WITH OVERCAST
SKIES...BUT THE BULK OF THE MEASURABLE PRECIP WILL REMAIN OUTSIDE
OF THE AREA ON SUNDAY. THE EXCEPTION WILL BE THE EASTERN FORECAST
AREA TOWARD EAU CLAIRE...WHICH WILL BE ON THE WESTERN EDGE OF THE
H85 MOISTURE TRANSPORT.
ON SUNDAY NIGHT...COLDER AIR BEGINS TO INFILTRATE THE AREA AS THE
PARENT SURFACE LOW LIFTS TO LAKE SUPERIOR. THE TWO PRIMARY
CONCERNS AS THIS OCCURS WILL BE VERY STRONG WINDS AND SNOW/BLOWING
SNOW. THE HIGHEST WINDS ARE FORECAST IN THE TYPICAL WEST/SOUTH
CENTRAL MN AREAS...WHERE MODELS INDICATE 40-45KTS AT THE TOP OF
THE CHANNEL. THE STRONGER FORCING FOR SNOW IS FORECAST TO BE A BIT
REMOVED FROM THE STRONGER WINDS /NORTHERN MN/WI/...SO IT REMAINS
TO BE SEEN HOW SIGNIFICANT VISIBILITY REDUCTIONS WILL BE GIVEN THE
SNOWPACK WILL HAVE ENDURED MELTING/RE-FREEZING/DRIZZLE.
WINDS SETTLE DOWN ON TUESDAY...THEN 850 MB TEMPS REDUCE TO AROUND
-15C LATE WEDNESDAY. ANOTHER WEAK WAVE CLIPS THE AREA ON
WEDNESDAY...BRINGING 20-30 PERCENT SNOW CHANCES. THESE VALUES
ARE AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AND TRANSLATE TO A
CHILLY THANKSGIVING DAY WITH HIGHS IN THE UPPER SINGLE DIGITS TO
MID TEENS. TEMPS REBOUND NICELY ON FRIDAY HOWEVER...WHEN HIGHS ARE
EXPECTED TO WARM INTO THE LOW/MID 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1148 AM CST SAT NOV 22 2014
IFR AND LOWER STRATUS CONTINUES TO SLOWLY CRAWL NW ACROSS
MN...STILL QUESTIONABLE WHETHER OR NOT IT REACHES AXN...BUT WITH
12Z TAF HAVING IT GETTING THERE...KEPT THAT TREND GOING. THESE
CIGS WILL ONLY MARGINALLY IMPROVE THROUGH THE AFTERNOON...LIKELY
JUST GOING FROM LIFR TO IFR BEFORE GOING BACK TO LIFR TONIGHT.
GIVEN CONTINUED SOUTH WINDS AND INCREASING MOISTURE OVER THE SNOW
THROUGH THE NIGHT...KEPT THE TREND FOR FG TONIGHT FROM 12Z TAFS
GOING. UNCERTAINTY STARTS TO INCREASE TOMORROW WITH THE POTENTIAL
FOR CIGS TO QUICKLY GO VFR. FOR NOW...TIMED IMPROVEMENT IN CIGS TO
WHEN WINDS ARE FORECAST TO SWING AROUND TO 240 DEGS OR GREATER.
SREF MVFR CIG PROBABILITY DROPS TO NEAR ZERO SUNDAY MORNING OUT
WEST...SO WE COULD VERY WELL SEE CIGS IMPROVE FASTER THAN
CURRENTLY INDICATED ACROSS MN. FOR PRECIP...LOOKING LIKE OUR BEST
CHANCE THIS TAF PERIOD WILL BE WITH A NARROW BAND OF RAIN THE
NMM/ARW/GFS/SREF SHOW COMING OUT OF SODAK LATE TONIGHT AND WORKING
ACROSS MN DURING THE MORNING.
KMSP...CONFIDENCE IS HIGH IN MINIMAL IMPROVEMENTS TO CIGS/VIS
THROUGH THE DAY. CONTINUED MOIST SRLY FLOW WILL ALSO LEAD TO A
LOWERING IN CONDITIONS TONIGHT...THOUGH THERE IS LESS CONFIDENCE
IN THE TIMING ON WHEN CIGS DROP BACK BELOW 005. 50/50 CONFIDENCE
ON THE FOG TEMPO GROUP...BUT WITH IT ALREADY IN THE TAF...LEFT IT
THERE. CONFIDENCE IS CONSIDERABLY LOWER THIS FAR OUT WITH
IMPROVEMENTS IN THE TAF BY SUNDAY AFTERNOON...BUT FOLLOWED THE
IDEA OF THE NAM/SREF ON THAT FOR NOW.
/OUTLOOK FOR KMSP/
MON...MVFR/IFR CIGS CHC -SN. WINDS NW 20G30 KT.
TUE...VFR. WINDS W 5-10 KT.
WED...MVFR/IFR CHC -SN. WINDS NW 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...SPD
LONG TERM...LS
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
555 AM CST SAT NOV 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM CST SAT NOV 22 2014
WARM AIR ADVECTION REGIME IS THE MAIN STORY OF THE SHORT TERM
PERIOD. BRISK SOUTHERLY WINDS HAVE ALLOWED TEMPERATURES TO CLIMB
ABOVE FREEZING /FOR THE FIRST TIME IN NEARLY TWO WEEKS/ OVERNIGHT
ACROSS SOUTHERN MN AND WESTERN WI. SURFACE DEW POINTS IN THE LOW
TO MID 30S CONTINUE TO PUSH NORTHWARD THROUGH IOWA AND WILL
CONTINUE FILLING IN ACROSS EASTERN MN AND WESTERN WI. WENT WITH A
PESSIMISTIC CLOUD/FOG FORECAST COMPARED TO MUCH OF THE GUIDANCE
WITH THE RELATIVE WARM AND MOIST AIR STREAMING NORTHWARD OVER THE
CURRENT SNOW PACK. DEW POINTS ACROSS WESTERN MN WILL LIKELY REMAIN
BELOW FREEZING THROUGH THE DAY AS THE BEST MOISTURE ADVECTION
STREAMING NORTHWARD TAKES AN EASTWARD TURN. MUCH OF SOUTHEASTERN
MN AND WESTERN WI ARE CURRENTLY SOCKED IN WITH LOW STRATUS AND
FOG...BUT MOSTLY CLEAR SKIES CAN BE FOUND TO THE WEST. THE HRRR
HAS PERFORMED WELL WITH THE COVERAGE OF THE CLOUDS/FOG...SO
WEIGHTED HEAVILY WITH THE HRRR IN THE SHORT RANGE FORECAST. THE
STRATUS DECK IS EXPECTED TO EXPAND SOME TO THE WEST THROUGH THE
MORNING...AND KEEP EASTERN MN AND WESTERN WI SOCKED IN THROUGH THE
DAY.
A COMPLICATED EVOLUTION OF THE FORECAST FOR TONIGHT THROUGH EARLY
SUNDAY MORNING. A NORTHERN STREAM SHORTWAVE WILL MOVE ACROSS
SOUTHERN CANADA TODAY AND MAKE IT TO MANITOBA TONIGHT.
MEANWHILE...THE SOUTHERN STREAM WAVE WILL BE PIVOTING OVER THE
SOUTHERN CONUS. THE BEST AREA OF LIFT WILL LARGELY REMAIN SOUTH OF
OUR AREA TONIGHT...BUT SOME MARGINAL LIFT ARRIVES TONIGHT AND WITH
SATURATED LOW LEVELS...DRIZZLE/LIGHT RAIN WILL BE POSSIBLE ACROSS
EASTERN MN AND WESTERN WI. WITH MODEL SOUNDINGS ALSO INDICATING A
VERY SATURATED NEAR SURFACE ENVIRONMENT...EXPANDED MENTION OF FOG IN
THE FORECAST...ESPECIALLY FOR WESTERN WI.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM CST SAT NOV 22 2014
A MILD START TO THE LONG TERM PERIOD PRIOR TO THE MERGING OF
NORTHERN AND SOUTHERN STREAM WAVES...AND THEN ANOTHER SURGE OF
ARCTIC AIR BLASTS THE REGION.
00Z MODEL SOLUTIONS WERE FAIRLY SIMILAR IN THEIR DEPICTION OF POPS
FOR SUNDAY...WITH THE FORECAST AREA BEING SOMEWHAT CAUGHT BETWEEN
THE TWO MAIN AREAS OF FORCING ASSOCIATED WITH THE AFOREMENTIONED
WAVES. THIS WILL MEAN SUNDAY WILL BE A FOGGY DAY WITH OVERCAST
SKIES...BUT THE BULK OF THE MEASURABLE PRECIP WILL REMAIN OUTSIDE
OF THE AREA ON SUNDAY. THE EXCEPTION WILL BE THE EASTERN FORECAST
AREA TOWARD EAU CLAIRE...WHICH WILL BE ON THE WESTERN EDGE OF THE
H85 MOISTURE TRANSPORT.
ON SUNDAY NIGHT...COLDER AIR BEGINS TO INFILTRATE THE AREA AS THE
PARENT SURFACE LOW LIFTS TO LAKE SUPERIOR. THE TWO PRIMARY
CONCERNS AS THIS OCCURS WILL BE VERY STRONG WINDS AND SNOW/BLOWING
SNOW. THE HIGHEST WINDS ARE FORECAST IN THE TYPICAL WEST/SOUTH
CENTRAL MN AREAS...WHERE MODELS INDICATE 40-45KTS AT THE TOP OF
THE CHANNEL. THE STRONGER FORCING FOR SNOW IS FORECAST TO BE A BIT
REMOVED FROM THE STRONGER WINDS /NORTHERN MN/WI/...SO IT REMAINS
TO BE SEEN HOW SIGNIFICANT VISIBILITY REDUCTIONS WILL BE GIVEN THE
SNOWPACK WILL HAVE ENDURED MELTING/RE-FREEZING/DRIZZLE.
WINDS SETTLE DOWN ON TUESDAY...THEN 850 MB TEMPS REDUCE TO AROUND
-15C LATE WEDNESDAY. ANOTHER WEAK WAVE CLIPS THE AREA ON
WEDNESDAY...BRINGING 20-30 PERCENT SNOW CHANCES. THESE VALUES
ARE AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AND TRANSLATE TO A
CHILLY THANKSGIVING DAY WITH HIGHS IN THE UPPER SINGLE DIGITS TO
MID TEENS. TEMPS REBOUND NICELY ON FRIDAY HOWEVER...WHEN HIGHS ARE
EXPECTED TO WARM INTO THE LOW/MID 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 542 AM CST SAT NOV 22 2014
WARM AND MOIST AIR CONTINUES ADVECTING NORTHWARD THIS MORNING AND
WILL PERSIST THROUGH THE PERIOD. WIDESPREAD LOW STRATUS AND FOG
WILL BE THE RULE AS LOW LEVEL SATURATION IS ONLY AIDED BY A
MELTING SNOW PACK AND SOUTHERLY MOISTURE ADVECTION. CHALLENGES LIE
IN TIMING OF IFR AND LIFR IMPACTS FOR EACH SITE...BUT OVERALL
EXPECT LOW CIGS TO REMAIN FOR THE EASTERN HALF TODAY...AS LOW
STRATUS SPREADS TO THE WEST SLOWLY AND WILL EVENTUALLY IMPACT ALL
TAF SITES. WESTERN SITES WILL SEE IMPROVEMENT FIRST AS DRIER AIR
LOOKS TO PUSH IN FROM THE DAKOTAS. THE FURTHER EAST YOU GO...THE
CONDITIONS WILL BE WORSE AND LAST LONGER. INCLUDED -DZ AT EAU
CLAIRE FOR TONIGHT AS MODEST LIFT MOVES THROUGH WESTERN WI. THE
ENTIRE ARE WILL BE SUSCEPTIBLE TO LOW VISIBILITIES IN FOG TONIGHT.
KMSP...IFR OR LOWER WILL BE COMMON...BUT CEILINGS MIGHT BE ABLE TO
SNEAK UP TO 1K FT THIS AFTERNOON BEFORE LOWERING AGAIN TONIGHT.
NOT TOO CONFIDENT IN THE VSBY FORECAST...ESPECIALLY TONIGHT. BUT
WANTED TO ADVERTISE THAT VIS COULD FALL QUITE LOW BY EARLY SUNDAY
MORNING. -DZ IS POSSIBLE TONIGHT BUT LOOKS MORE PROMISING
EAST...SO LEFT IT OUT OF THE TAF FOR NOW.
/OUTLOOK FOR KMSP/
SUN...MVFR/IFR WITH FZDZ/-RA POSSIBLE. WINDS SE 10 KT.
MON...MVFR/IFR WITH -SN/BLSN POSSIBLE. WINDS NW 25G30 KT.
TUES...VFR/MVFR WITH -SN POSSIBLE EARLY. WINDS NW 10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...SPD
LONG TERM...LS
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
440 AM CST SAT NOV 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM CST SAT NOV 22 2014
WARM AIR ADVECTION REGIME IS THE MAIN STORY OF THE SHORT TERM
PERIOD. BRISK SOUTHERLY WINDS HAVE ALLOWED TEMPERATURES TO CLIMB
ABOVE FREEZING /FOR THE FIRST TIME IN NEARLY TWO WEEKS/ OVERNIGHT
ACROSS SOUTHERN MN AND WESTERN WI. SURFACE DEW POINTS IN THE LOW
TO MID 30S CONTINUE TO PUSH NORTHWARD THROUGH IOWA AND WILL
CONTINUE FILLING IN ACROSS EASTERN MN AND WESTERN WI. WENT WITH A
PESSIMISTIC CLOUD/FOG FORECAST COMPARED TO MUCH OF THE GUIDANCE
WITH THE RELATIVE WARM AND MOIST AIR STREAMING NORTHWARD OVER THE
CURRENT SNOW PACK. DEW POINTS ACROSS WESTERN MN WILL LIKELY REMAIN
BELOW FREEZING THROUGH THE DAY AS THE BEST MOISTURE ADVECTION
STREAMING NORTHWARD TAKES AN EASTWARD TURN. MUCH OF SOUTHEASTERN
MN AND WESTERN WI ARE CURRENTLY SOCKED IN WITH LOW STRATUS AND
FOG...BUT MOSTLY CLEAR SKIES CAN BE FOUND TO THE WEST. THE HRRR
HAS PERFORMED WELL WITH THE COVERAGE OF THE CLOUDS/FOG...SO
WEIGHTED HEAVILY WITH THE HRRR IN THE SHORT RANGE FORECAST. THE
STRATUS DECK IS EXPECTED TO EXPAND SOME TO THE WEST THROUGH THE
MORNING...AND KEEP EASTERN MN AND WESTERN WI SOCKED IN THROUGH THE
DAY.
A COMPLICATED EVOLUTION OF THE FORECAST FOR TONIGHT THROUGH EARLY
SUNDAY MORNING. A NORTHERN STREAM SHORTWAVE WILL MOVE ACROSS
SOUTHERN CANADA TODAY AND MAKE IT TO MANITOBA TONIGHT.
MEANWHILE...THE SOUTHERN STREAM WAVE WILL BE PIVOTING OVER THE
SOUTHERN CONUS. THE BEST AREA OF LIFT WILL LARGELY REMAIN SOUTH OF
OUR AREA TONIGHT...BUT SOME MARGINAL LIFT ARRIVES TONIGHT AND WITH
SATURATED LOW LEVELS...DRIZZLE/LIGHT RAIN WILL BE POSSIBLE ACROSS
EASTERN MN AND WESTERN WI. WITH MODEL SOUNDINGS ALSO INDICATING A
VERY SATURATED NEAR SURFACE ENVIRONMENT...EXPANDED MENTION OF FOG IN
THE FORECAST...ESPECIALLY FOR WESTERN WI.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM CST SAT NOV 22 2014
A MILD START TO THE LONG TERM PERIOD PRIOR TO THE MERGING OF
NORTHERN AND SOUTHERN STREAM WAVES...AND THEN ANOTHER SURGE OF
ARCTIC AIR BLASTS THE REGION.
00Z MODEL SOLUTIONS WERE FAIRLY SIMILAR IN THEIR DEPICTION OF POPS
FOR SUNDAY...WITH THE FORECAST AREA BEING SOMEWHAT CAUGHT BETWEEN
THE TWO MAIN AREAS OF FORCING ASSOCIATED WITH THE AFOREMENTIONED
WAVES. THIS WILL MEAN SUNDAY WILL BE A FOGGY DAY WITH OVERCAST
SKIES...BUT THE BULK OF THE MEASURABLE PRECIP WILL REMAIN OUTSIDE
OF THE AREA ON SUNDAY. THE EXCEPTION WILL BE THE EASTERN FORECAST
AREA TOWARD EAU CLAIRE...WHICH WILL BE ON THE WESTERN EDGE OF THE
H85 MOISTURE TRANSPORT.
ON SUNDAY NIGHT...COLDER AIR BEGINS TO INFILTRATE THE AREA AS THE
PARENT SURFACE LOW LIFTS TO LAKE SUPERIOR. THE TWO PRIMARY
CONCERNS AS THIS OCCURS WILL BE VERY STRONG WINDS AND SNOW/BLOWING
SNOW. THE HIGHEST WINDS ARE FORECAST IN THE TYPICAL WEST/SOUTH
CENTRAL MN AREAS...WHERE MODELS INDICATE 40-45KTS AT THE TOP OF
THE CHANNEL. THE STRONGER FORCING FOR SNOW IS FORECAST TO BE A BIT
REMOVED FROM THE STRONGER WINDS /NORTHERN MN/WI/...SO IT REMAINS
TO BE SEEN HOW SIGNIFICANT VISIBILITY REDUCTIONS WILL BE GIVEN THE
SNOWPACK WILL HAVE ENDURED MELTING/RE-FREEZING/DRIZZLE.
WINDS SETTLE DOWN ON TUESDAY...THEN 850 MB TEMPS REDUCE TO AROUND
-15C LATE WEDNESDAY. ANOTHER WEAK WAVE CLIPS THE AREA ON
WEDNESDAY...BRINGING 20-30 PERCENT SNOW CHANCES. THESE VALUES
ARE AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AND TRANSLATE TO A
CHILLY THANKSGIVING DAY WITH HIGHS IN THE UPPER SINGLE DIGITS TO
MID TEENS. TEMPS REBOUND NICELY ON FRIDAY HOWEVER...WHEN HIGHS ARE
EXPECTED TO WARM INTO THE LOW/MID 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1046 PM CST FRI NOV 21 2014
LOW CLOUDS ARE CURRENTLY BEING ADVECTED NORTHWARD THROUGH SOUTHEAST
MN AND WESTERN WI. THIS STRATUS DECK WILL CONTINUE TO OVERSPREAD
EASTERN TERMINALS...WHERE IFR CIGS WILL DEVELOP WITHIN THE NEXT
COUPLE HOURS. THE LOW STRATUS DECK OVER EASTERN TERMINALS SHOULD
BUILD NORTHWESTWARD BY SATURDAY MORNING...AND IFR/LIFR CIGS COULD
DEVELOP OVER ALL TERMINALS BY THIS TIME. THE POTENTIAL FOR PATCHY
FOG ALSO EXISTS...AS THE HRRR AND HOPWRF SHOW VISIBILITIES LESS THAN
A MILE ACROSS THE REGION SATURDAY MORNING. WHILE THERE IS STILL SOME
DISAGREEMENT...MOST MODELS SHOW THE POTENTIAL FOR A PROLONGED PERIOD
OF IFR/LIFR CIGS AT ALL TERMINALS THROUGH SATURDAY EVENING AS WARM
MOIST AIR IS ADVECTED OVER THE SNOW PACK.
KMSP...IFR CIGS WILL DEVELOP WITHIN THE NEXT COUPLE HOURS AS A LOW
CLOUD DECK DEVELOPS. IFR/LIFR CIGS AND REDUCED VISIBILITIES ARE
LIKELY SATURDAY MORNING THROUGH THE EVENING AS LOW CLOUDS AND
POSSIBLY PATCHY FOG PERSIST. MEASURABLE PRECIP SHOULD REMAIN TO THE
SOUTHEAST ON SATURDAY WITH SOME PATCHY DRIZZLE POSSIBLE IN THE
EVENING...THOUGH CHANCES OF PRECIPITATION REMAIN LOW.
/OUTLOOK FOR KMSP/
SUN...MVFR/IFR WITH FZDZ/-RA POSSIBLE. WINDS SE 10 KT.
MON...MVFR/IFR WITH -SN/BLSN POSSIBLE. WINDS NW 25G30 KT.
TUES...VFR/MVFR WITH -SN POSSIBLE EARLY. WINDS NW 10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...SPD
LONG TERM...LS
AVIATION...ADL
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1137 PM CST FRI NOV 21 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 422 PM CST FRI NOV 21 2014
THERE ARE A COUPLE FORECAST CHALLENGES OVER THE NEXT FEW DAYS. THE
FIRST: IS THE SLIGHT CHANCE FOR LIGHT FREEZING RAIN OR FREEZING
DRIZZLE IN FAR EASTERN MN AND WEST CENTRAL WI TONIGHT. THE SECOND:
IS THE MIXED P-TYPE AND WIND EVENT SUNDAY INTO MONDAY.
THERE HAS BEEN A STEADY STREAM OF HIGH CLOUDS TODAY...BUT THERE IS A
LOW STRATUS DECK STREAMING NORTH ACROSS SOUTHERN NE/IA THIS
AFTERNOON. THESE CLOUDS ARE TIED TO LOW LEVEL MOISTURE ADVECTION OUT
AHEAD OF AN ADVANCING SHORTWAVE CURRENTLY TRANSVERSE THE NORTHERN
PLAINS THIS AFTERNOON. WE THINK THERE WILL BE DEEPER SATURATION AND
BETTER OMEGA TO THE SOUTH AND WEST OF THE FORECAST AREA THIS EVENING
AND TONIGHT /BASICALLY INN AREAS CURRENTLY UNDER A FREEZING RAIN
ADVISORY/. THE SREF PROBABILITIES OF FREEZING RAIN/DRIZZLE ARE ON
THE ORDER OF 40-80% IN THESE AREAS. LOCALLY...WE`RE NOT CONFIDENT IN
MUCH ELSE BESIDES A HEALTHY STRATUS DECK AND PERHAPS SOME LIGHT FOG
AS THE STRATUS LOWERS. WE MAINTAINED LOW PROBS OF PRECIP IN EASTERN
PORTIONS OF THE FORECAST AREA WITH A MIX...AND IT ONLY TAKES A SMALL
AMOUNT OF FREEZING RAIN/DRIZZLE TO CAUSE PROBLEMS...BUT AS OF RIGHT
NOW THE BETTER LIFT AND DEEPER MOISTURE IS SOUTHEAST OF THE FORECAST
AREA. WE FOLLOWED THE LATEST REFLECTIVITY TRENDS OF THE HRRR...WHICH
MATCH UP REASONABLY WELL WITH THE 0.5KM CONDENSATION PRESSURE
DEFICITS OFF THE 20Z-22Z RAP.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 422 PM CST FRI NOV 21 2014
SPLIT FLOW WILL KEEP THE AREA LARGELY DRY INTO SUNDAY AFTERNOON
AS THE SOUTHERN STREAM LIFTS A TROUGH NORTHWARD FROM THE SOUTHERN
PLAINS INTO THE MID MISSISSIPPI VALLEY ON SUNDAY WHILE A TROUGH
DIGS INTO THE NORTHERN HIGH PLAINS ALONG THE NORTHERN STREAM.
THE NEXT MOIST SURGE MOVES IN WITH A STRONG WARM FRONT SATURDAY
EVENING AND OVERNIGHT. MODEL SIGNALS OF WARM FRONTAL
LIFT...850MB MOISTURE TRANSPORT CONVERGENCE...AND MOISTURE
ADVECTION INDICATE A FAIRLY HIGH LIKELIHOOD OF RAIN...PROBABLY
HIGHER THAN GUIDANCE INDICATES. AT THIS TIME...IT APPEARS THE
MODEL CONSENSUS AGREES THAT ONLY MINOR PRECIPITATION WOULD GO INTO
SNOW SUNDAY NIGHT AS COLDER AIR MOVES IN. THE FORECAST
SOUNDINGS...ESPECIALLY OFF THE NAM SHOW 35-40KTS AT THE TOP OF THE
MIXED LAYER WITH STEEP LOW LEVEL LAPSE RATES FOR 12-15 HOURS
SUNDAY NIGHT AND MONDAY. THE CONDITION OF THE SNOWPACK WILL BE IN
QUESTION IN THE EAST WITH THE SLIGHTLY WARMER TEMPS AND CHANCE FOR
RAIN...BUT WESTERN MN WILL REMAIN MUCH COOLER AND WE COULD ALSO
PICK UP A HIGH RATIO 0.5-2.0" IN SPOTS...SO THE THREAT FOR BLOWING
SNOW IS STILL A CONCERN IN WESTERN MN. WINTER HEADLINES ARE STILL
POSSIBLE FOR THIS PERIOD. ANOTHER COLD PERIOD BEGINS MONDAY AND
CURRENT THANKSGIVING HIGHS ARE IN THE TEENS AS A COLD AIR MASS
SETTLES IN AFTER A WEAK SYSTEM WEDNESDAY. THIS AIR MASS IN THE
NAEFS AND GEFS IS ABOUT 2 STANDARD DEVIATIONS BELOW NORMAL FOR
THURSDAY. THE OPERATIONAL RUNS ARE ALSO QUITE COLD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1046 PM CST FRI NOV 21 2014
LOW CLOUDS ARE CURRENTLY BEING ADVECTED NORTHWARD THROUGH SOUTHEAST
MN AND WESTERN WI. THIS STRATUS DECK WILL CONTINUE TO OVERSPREAD
EASTERN TERMINALS...WHERE IFR CIGS WILL DEVELOP WITHIN THE NEXT
COUPLE HOURS. THE LOW STRATUS DECK OVER EASTERN TERMINALS SHOULD
BUILD NORTHWESTWARD BY SATURDAY MORNING...AND IFR/LIFR CIGS COULD
DEVELOP OVER ALL TERMINALS BY THIS TIME. THE POTENTIAL FOR PATCHY
FOG ALSO EXISTS...AS THE HRRR AND HOPWRF SHOW VISIBILITIES LESS THAN
A MILE ACROSS THE REGION SATURDAY MORNING. WHILE THERE IS STILL SOME
DISAGREEMENT...MOST MODELS SHOW THE POTENTIAL FOR A PROLONGED PERIOD
OF IFR/LIFR CIGS AT ALL TERMINALS THROUGH SATURDAY EVENING AS WARM
MOIST AIR IS ADVECTED OVER THE SNOW PACK.
KMSP...IFR CIGS WILL DEVELOP WITHIN THE NEXT COUPLE HOURS AS A LOW
CLOUD DECK DEVELOPS. IFR/LIFR CIGS AND REDUCED VISIBILITIES ARE
LIKELY SATURDAY MORNING THROUGH THE EVENING AS LOW CLOUDS AND
POSSIBLY PATCHY FOG PERSIST. MEASURABLE PRECIP SHOULD REMAIN TO THE
SOUTHEAST ON SATURDAY WITH SOME PATCHY DRIZZLE POSSIBLE IN THE
EVENING...THOUGH CHANCES OF PRECIPITATION REMAIN LOW.
/OUTLOOK FOR KMSP/
SUN...MVFR/IFR WITH FZDZ/-RA POSSIBLE. WINDS SE 10 KT.
MON...MVFR/IFR WITH -SN/BLSN POSSIBLE. WINDS NW 25G30 KT.
TUES...VFR/MVFR WITH -SN POSSIBLE EARLY. WINDS NW 10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...CLF
AVIATION...ADL
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
946 PM CST Sun Nov 23 2014
.UPDATE...
Issued at 944 PM CST SUN NOV 23 2014
Back edge of rain shield has accelerated eastward over the past hour
in line with the 00Z NAM and latest HRRR output. Will end the rain
faster from west to east. In addition, will limit any mention of snow
to the n central and northeastern counties where temperatures in the
upper 30s are advecting southeast out of central/south central IA.
Will leave in mention of minor snow accumulations for these areas.
&&
.SHORT TERM...(This Evening through Wednesday Afternoon)
Issued at 307 PM CST SUN NOV 23 2014
Rain showers will continue to fill in this afternoon and evening,
impacting the forecast area along and ahead of a southeastward-
moving cold front. Rainfall totals for this evening should be mainly
less than a half of an inch in most locations.
Main focus in the short term will be the potential for rain changing
over to snow overnight as a cold front pushes through the area and a
band of post-frontal precipitation pushes eastward over the falling
temperatures. Soundings begin to support snow in our far northwest
around 03z to 06z, but initially the surface warm layer will be too
thick for snow to make it to the surface. As the near-surface layer
cools, rain will begin to mix with and then eventually change over
to snow mainly between 06z and 12z tonight. Precipitation amounts
during this time are anywhere from trace to 0.20", but with the warm
temperatures ahead of the front and warm/wet surface conditions, it
will take a pretty aggressive snow rate to accumulate any snow. Have
painted an area of 0.5-0.75" snow across northeast MO where the
coldest post-frontal temperatures and highest snowfall rates are
expected as the band moves through, then have tapered snow amounts
to zero elsewhere. The post-frontal band is expected to exit the
region by 12z, then perhaps just a dusting of light snow could wrap
back into northeast MO during the late morning/afternoon hours.
Lows tonight should not drop far below freezing with the bulk of the
cold air waiting until after 12z to push into the region, but little
to no temperature rise is expected across northern MO on Monday as
cold air continues to filter in. Elsewhere, highs may recover a bit
into the lower 40s by mid afternoon.
The next system will be a quick clipper that dives from Alberta into
northeast Missouri on Tuesday night into Wednesday morning. Light
snow is possible across the northeastern half of the CWA with this
feature, but low moisture availability will limit potential snow
accumulations to just a few tenths of an inch.
.LONG TERM...(Wednesday Evening through Sunday)
Issued at 307 PM CST SUN NOV 23 2014
Much of the long-term (particularly into next weekend) is plagued
spatially and temporally with model discrepancies with the GFS,
ECMWF, and the GEM struggling to agree, although the 12Z ECMWF has
come into a bit of a better agreement with the 12Z GFS as compared
to the 00Z ECMWF run. Low amplitude ridging at the 500mb level
appears to dominate much of the center of the country behind an
exiting sharp trough, according to the latest GFS and ECMWF runs
whereas the GEM brings a shortwave trough racing down from Canada
into MT/ND before phasing into a larger wave dominating over
Ontario. Regardless of which solution ends up playing out, they do
all generally agree on zonal flow aloft with ripples riding through
behind the NW flow on the backside of the aforementioned exiting
trough.
Between the GFS and the ECMWF, the GFS appears to be much more
progressive aloft and at the surface as compared to the ECMWF. High
pressure sinking south behind an exiting surface low takes hold of
the forecast area on Thursday, then quickly scoots across the Ohio
Valley, leaving the door open for a frontal boundary to sweep
through behind the high, according to the GFS. The ECMWF solution is
messier and slower and diverges significantly from the GFS at the
surface by next weekend. Taking all of this into account, have kept
the forecast area dry for this forecast period given a lack of a
clear precip-generating signal, except for the GFS that brings the
front through on Saturday, but again is low confidence given the
vastly different solutions.
With respect to temperatures, they look to remain on the cooler side
of normal through the end of the week, but again, the forecast for
the temps from late Friday onward has low confidence given the
discussed model discrepancies.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 515 PM CST SUN NOV 23 2014
Cold front has made its way through the terminals area with increased
precipitation occurring along and behind the boundary. Will see
gradually improving ceilings as drier air filters in behind the
front. Gusty NW winds look to stay in place through the forecast
period. There is a chance of a rain/snow mix overnight though will
remain short-lived with no significant accumulation expected due to
warm surface temperatures. Once the precipitation clears out low-
level scattered layer will remain in place through the forecast
period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...Laflin
LONG TERM...lg
AVIATION...Welsh
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
347 PM CST Sat Nov 22 2014
.SHORT TERM: (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014
Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains. Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area. This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z. While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight. By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough. With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.
Britt
.LONG TERM: (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014
Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains. The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region. The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday. There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL. Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front. The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains. As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL. Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL. Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area. An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday. The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.
GKS
&&
.AVIATION: (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1235 PM CST Sat Nov 22 2014
Have added tempo groups for showers later this afternoon and early
this evening at the STL metro TAF sites as an area of showers over
southwest Missouri moves northeast. MVFR ceilings are expected
through 10-15Z when a steadier rain is expected to develop. Once
this steady rain moves into the area, IFR conditions are expected
on Sunday at all TAF sites.
Specifics for KSTL: Expect ceilings between 2000-3000ft through
22Z. Then an area of showers will move into the terminal from the
southwest which may cause ceilings to fall below 2000ft into the
early evening hours. Then expect most of the night to be dry with
just scattered showers in the area before lower ceilings and more
widespread showers move into the area after 09Z, with steady rain
and IFR conditions moving into the area by mid morning Sunday.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1235 PM CST Sat Nov 22 2014
.UPDATE:
Issued at 1234 PM CST Sat Nov 22 2014
Have updated forecast to include area of showers and isolated
thunderstorms that have moved into southeast Missouri as well as
far southwest Illinois. HRRR is also showing that area of showers
over far southwest Missouri will move into east central Missouri
and adjacent parts of Illinois late this afternoon and early this
evening. Increased chances to likely in both these locations.
Temperatures have already climbed into upper 50s and lower 60s in
most areas, so have increased high temperatures accordingly.
Britt
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 322 AM CST Sat Nov 22 2014
Main area of precipitation has moved out of region, though there is
some widely scattered activity as well as drizzle over northern
portions of forecast area early this morning. Next shortwave to
slide northeast through forecast area today, but precipitation will
continue to be scattered in nature. Some elevated instability over
southern portions of region this afternoon, so still could see
isolated thunder in this area. Otherwise, just scattered showers
under cloudy skies. Temperatures to be near normal or just above
normal in the mid 50s to low 60s.
Byrd
.LONG TERM: (Tonight through Friday)
Issued at 322 AM CST Sat Nov 22 2014
(Tonight-Monday)
Overall forecast trends still looking pretty good, and main
changes will be an attempt to fine-tune these trends.
This afternoon`s expected scattered coverage will likely linger into
this evening, but precipitation threat should ramp up considerably
late tonight and into Sunday as dynamics from strong upper system
working northeast from the southern plains and increasing moisture
begin to come into phase over the region. Like the trends suggested
by 00z model QPFs that by Sunday morning main focus of rain will
stretch from southwest into northeast Missouri, with this band of
rain then expanding and working east during the day. With the above
trends in mind, I`ve also attempted to minimize PoPs in our far e
counties until Sunday afternoon, as moisture and lift will be
somewhat limited in this part of the FA until then. Although
instability is progged by all models to remain quite limited due to
saturated AMS I`ve continued a mention of thunder over the Ozarks
tonight and into the southeast half of the CWA on Sunday.
All of the 00z output is continuing to suggest that as dynamics with
the first system pushes into the Ohio Valley on Sunday evening, a
secondary area of precip should develop in its wake as another
shortwave drops into the base of the longwave trof. Ptypes could
become an issue by late Sunday night on the back edge of this round
of precip as southward surge of cold air will be causing the
freezing levels to drop; however at this time not expecting any
major issues as forecast soundings suggest ams will get cold enough
to support snow just as the precip begins to wind down. Threat of
measurable precip with this secondary shortwave should come to an
end on Monday morning, although we do anticipate that some flurries
will linger into the afternoon over northern sections of the CWA
where cold advection and cyclonic low level flow will be the
strongest.
Today`s moderation in temps will persist into Sunday, but return
of cold air will mean more below average temperatures for the
start of the new week.
(Tuesday-Friday)
Surface ridge is expected to work across the region on Tuesday,
giving the FA chilly but dry late November weather. It still
appears that another fast moving shortwave digging into
progressive longwave trof will produce a quick shot of lift across
the region by Wednesday, but strongest dynamics will be north of
our area and moisture will be quite limited, so going slight
chance/low chance PoPs still look good at midweek.
Medium range solutions still leaving questions regarding sensible
weather trends heading into the Thanksgiving holiday. GFS is now
supported by the GEM in suggesting much less deepening of the
longwave trof over the eastern CONUS. This keeps baroclinicity
further north and allows the next fast moving shortwave to interact
with this thermal gradient, which would suggest a threat of some
light precip on Thanksgiving over northern sections of the CWA.
ECMWF is still deeper with the trof to our east, but its interesting
that its not as deep as was suggested in yesterday`s guidance, and
in fact has trended a bit more towards a flatter mid level flow.
For now will maintain dry forecast, but this trend will be
interesting to watch over the next few forecast cycles.
With the reintensification of the trof over the eastern CONUS temps
will remain well below normal during the latter half of the
upcoming work week, although exact extent of the cold will
obviously depend on the intensity of the trof. Highs primarily in
the 30s heading into Thursday and Friday look like a good starting
point for now.
Truett
&&
.AVIATION: (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1235 PM CST Sat Nov 22 2014
Have added tempo groups for showers later this afternoon and early
this evening at the STL metro TAF sites as an area of showers over
southwest Missouri moves northeast. MVFR ceilings are expected
through 10-15Z when a steadier rain is expected to develop. Once
this steady rain moves into the area, IFR conditions are expected
on Sunday at all TAF sites.
Specifics for KSTL: Expect ceilings between 2000-3000ft through
22Z. Then an area of showers will move into the terminal from the
southwest which may cause ceilings to fall below 2000ft into the
early evening hours. Then expect most of the night to be dry with
just scattered showers in the area before lower ceilings and more
widespread showers move into the area after 09Z, with steady rain
and IFR conditions moving into the area by mid morning Sunday.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1210 AM CST Sat Nov 22 2014
.UPDATE:
Issued at 1008 PM CST Fri Nov 21 2014
Weak lift and mid level moisture associated with a low-amplitude shortwave
currently located in western MO combined with lift via a southwesterly
LLJ has generated some showers this evening. These showers were
currenly located to the west of the MS river across southwest and
south central IL, moving to the northeast at 30-35 kts. The showers
should exit the CWA by midnight as the shortwave continues to
migrate eastward in the west-southwest flow aloft, also taking the
mid level moisture with it. In its wake during the overnight
hours, the atmosphere will be bottom heavy with moisture confined
to the low levels. This moisture stratification along with continued
weak ascent via low level WAA would support patchy light rain or
drizzle. Accordingly I have lowered pops a bit and refined the
precipitation mode.
Glass
&&
.SHORT TERM: (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014
Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains. There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri. Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois. Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence. At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area. Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.
Britt
.LONG TERM: (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014
At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area. The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains. There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region. A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL. Temperatures will be
much warmer this weekend and above normal for a change. Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front. There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region. The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region. Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday. Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US. The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF. A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.
GKS
&&
.AVIATION: (For the 06z TAFs through 06z Saturday Night)
Issued at 1134 PM CST Fri Nov 21 2014
MVFR conditions are expected to prevail overnight and for most of
tomorrow. Some improvement is possible at KCOU between 22/21z and
23/06z before conditions deteriorate again. Light drizzle is
possible overnight. Widespread rain is likely just beyond the end
of the 24-hr TAF period.
Specifics for KSTL: Although conditions may occasionally lift to
VFR for brief periods overnight, MVFR cigs are expected to prevail
until mid to late morning. Light drizzle is also possible.
Widespread rain is likely towards the end of the 30-hr TAF period
and beyond.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1131 PM CST Fri Nov 21 2014
.UPDATE...
Issued at 912 PM CST FRI NOV 21 2014
Trimmed back overnight PoPs as deeper moisture as noted in IR
satellite imagery and radar returns is peeling off to the northeast.
00z NAM and RUC h7 condensation pressure deficit progs support this
as does the miniscuel reflectivity returns on the HRRR. Bufr
soundings are more supportive of drizzle forming overnight. Will
stratify PoPs with best chances for rain over the southeast 1/3 of
the CWA. Deeper moisture doesn`t arrive from teh southwest until
later Saturday afternoon so until then think low chance PoPs the best
one can do.
&&
.DISCUSSION...
Issued at 309 PM CST FRI NOV 21 2014
Main concern in the short term will be fog, stratus, and light
showers as a broad area of warm air advection continues across the
region. Without a strong focus for lift, any precipitation tonight
into Saturday should be fairly light throughout the region. Dense
fog looks likely mainly across eastern Kansas and northwest MO where
moisture will remain fairly shallow; farther to the southeast, low
stratus and continued isolated showers seem more likely. May need a
dense fog advisory in far western and northwestern portions of the
CWA tonight, but will wait to see how efficiently fog develops later
this evening. Another round of dense fog looks possible on Saturday
night across far northern MO and especially further to the north in
IA, with continued stratus to the south.
Rain will become more widespread for Sunday as a shortwave trough
lifts out of the southern Plains and into eastern MO, and a surface
low tightens up over central portions of the state. Rain is most
likely and potential precipitation totals are highest across far
eastern portions of the CWA, but at least some rainfall is likely as
far west as the KC metro during the daylight hours. Timing for the
exit of this system is still a little uncertain, but rain should be
tapering off by late Sunday evening into the early morning hours
Monday. A second system is still also expected to sweep in from the
northern Plains on Sunday, bringing colder air into northern MO by
late Sunday and into the remainder of the state on Monday. Rain may
briefly mix with or change over to snow in northern MO late Sunday
night or early Monday as the first system departs and cold air
surges in, but warm/wet ground and depleted moisture will prevent
any snow accumulation.
Colder temperatures are expected Monday and Tuesday as the second
system continues to dive southeast and allows Canadian air to filter
into the central CONUS; then some brief warming is possible
Wednesday as that system departs. The latest 2 runs of both the EC
and GFS have finally come into much better alignment for Thursday
and Friday, indicating a rather cold but dry Thanksgiving, but a
quick warm up for Friday beyond the end of the period. Have removed
all PoPs beyond the weekend system, leaving the long-range forecast
period dry.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1118 PM CST FRI NOV 21 2014
Surface conditions beginning to degrade as moisture from the south
continues to work its way north. Will see the onset of fog
development during the overnight hours initiating IFR ceilings with
a period of LIFR ceiling heights shortly thereafter. Not much anticipated
in the way of precipitation other than light drizzle coupled with the
fog. IFR ceilings expected to persist throughout the morning while
increased chances of precipitation will commence in the afternoon.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
DISCUSSION...Laflin
AVIATION...Welsh
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1013 PM CST Fri Nov 21 2014
.UPDATE:
Issued at 1008 PM CST Fri Nov 21 2014
Weak lift and mid level moisture associated with a low-amplitude shortwave
currently located in western MO combined with lift via a southwesterly
LLJ has generated some showers this evening. These showers were
currenly located to the west of the MS river across southwest and
south central IL, moving to the northeast at 30-35 kts. The showers
should exit the CWA by midnight as the shortwave continues to
migrate eastward in the west-southwest flow aloft, also taking the
mid level moisture with it. In its wake during the overnight
hours, the atmosphere will be bottom heavy with moisture confined
to the low levels. This moisture stratification along with continued
weak ascent via low level WAA would support patchy light rain or
drizzle. Accordingly I have lowered pops a bit and refined the
precipitation mode.
Glass
&&
.SHORT TERM: (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014
Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains. There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri. Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois. Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence. At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area. Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.
Britt
.LONG TERM: (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014
At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area. The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains. There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region. A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL. Temperatures will be
much warmer this weekend and above normal for a change. Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front. There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region. The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region. Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday. Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US. The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF. A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.
GKS
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 522 PM CST Fri Nov 21 2014
MVFR cigs are expected to prevail overnight, however there may be
occasional brief periods of low-end VFR ceilings. Widely scattered
rain showers are possible through the period, especially at KCOU and
KUIN. A 50kt southwesterly LLJ will likely produce LLWS conditions
at all terminals between 05-14z.
Specifics for KSTL: MVFR cigs are expected to prevail overnight,
however there may be occasional brief periods of low-end VFR
ceilings. Widely scattered rain showers are possible through the
period. The highest rain chances at KSTL are expected beyond the
end of the 30-hr TAF period. A 50kt southwesterly low level jet
will likely produce LLWS conditions between 05-14z.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
323 PM MST SAT NOV 22 2014
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...
THIS AFTERNOON...A STRONG SURFACE LOW PRESSURE SYSTEM HAS DRAWN A
COLD FRONT THROUGH NORTHEAST MONTANA. WEST WINDS BEHIND THE SYSTEM
HAVE BEEN QUITE STRONG...TOPPING 30 MPH IN PLACES NEAR THE WESTERN
EDGE OF THE CWA. 750MB WINDS ARE QUITE STRONG AND SOME CLEARING
SKIES OUT WEST HAVE ALLOWED SOMEWHAT BETTER MIXING IN THAT AREA.
WINDS SHOULD EASE A LITTLE BIT AFTER DARK...HOWEVER...STRONG
SURFACE PRESSURE GRADIENT WILL KEEP WINDS IN THE MODERATE TO
STRONG LEVEL TONIGHT AND THROUGH TOMORROW AFTERNOON. WINDS WILL
VEER MORE NORTHERLY TONIGHT WITH STRONGER COLD ADVECTION.
INITIAL ROUND OF LIGHT RAIN SHOWERS HAS MOVED OFF EAST OF THE
AREA WITH SNOW SHOWERS EXPECTED THIS EVENING COMING DOWN FROM THE
NORTH ALONG THE CANADIAN BORDER. CLEARING BEHIND THIS INITIAL WAVE
IS RELATED TO Q-VECTOR DIVERGENCE AND DRY SLOT BEHIND POSITIVE
VORTICITY ADVECTION AREA. SNOW SHOWERS ARE IN WRAP AROUND AREA
AND OCCUR WITH COLD AIR ADVECTION TONIGHT. SNOW AMOUNTS ARE NOT
EXPECTED TO BE GREAT...WITH ANYWHERE FROM A HALF INCH TO 2 INCHES
EXPECTED THROUGH SUNDAY. HIGH RESOLUTION MODELS HAVE LESS SNOW
THAN THE SYNOPTIC MODELS. THE HRRR HAS ALMOST NONE. THE NAM...ON
THE OTHER HAND...HAS SOME LOCALIZED AREAS OF MODERATE SNOW. WITH
STRONG WINDS...AN INCH OF SNOW COULD BLOW AROUND ENOUGH TO CAUSE
TRAVEL DIFFICULTIES...SO ISSUED AN ADVISORY FOR BLOWING SNOW.
SYSTEM PROGRESSES FAIRLY QUICKLY EASTWARD AND SHOWERS LOOK TO END
LATE SUNDAY AFTERNOON. MARTIN
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
THE EXTENDED PERIOD WILL SEE A LONG-WAVE TROUGHS OVER THE EAST HALF
OF THE NATION AND CANADA. THESE TROUGHS WILL BE ANCHORED BY THE
PERSISTENT ARCTIC LOW OVER THE NUNAVUT TERRITORY OF CANADA. THIS
LOW WILL SEE SHORT-WAVE TROUGH ROTATE AROUND THE MAIN LOW CENTER.
THESE SHORT-WAVES WILL LARGELY DETERMINE TEMPERATURES FOR NORTHEAST
MONTANA THROUGH THE EXTENDED PERIOD. OFF TO THE WEST THERE WILL BE
AN EQUALLY PERSISTENT RIDGE THAT WILL LARGELY MAINTAIN NORTHWEST
FLOW ALOFT FOR OUR REGION.
TUESDAY EVENING NORTHEAST MONTANA WILL BE ON THE COLD SIDE OF THE
BOUNDARY BETWEEN THE WESTERN AND EASTERN AIR-MASSES. THERE WILL BE
MOVEMENT OF A SHORT-WAVE EXTENDING FROM THE CANADIAN LOW. IN
COINCIDENCE WILL BE A DISTURBANCE RIDGING OVER THE TOP OF THE RIDGE.
THE ACTION BETWEEN THESE TWO DISTURBANCES WILL AT FIRST BE A
SIGNIFICANT AMOUNT OF MOISTURE OVERRIDING THE LENGTH OF THE
BOUNDARY. THIS WILL PRODUCE RAIN OF THE WARM SIDE AND WINTRY MIX
ON THE EAST SIDE. THE MAIN FORECAST CHALLENGE OF THE EXTENDED
PERIOD WILL BE THE LOCATION OF THE BOUNDARY IN RELATION TO
NORTHEAST MONTANA. A DIFFERENCE OF JUST A FEW HUNDRED MILES WILL
MAKE A LARGE DIFFERENCE IN TEMPERATURES.
TUESDAY...BOTH THE GFS AND EC PLACE THE BOUNDARY JUST TO OUR WEST
WHICH WILL LEAD TO SLIGHTLY COOLER THAN NORMAL TEMPERATURES. THE
OVERRUNNING MOISTURE ALSO APPEARS TO BE RUNNING PRECIPITATION TO
OUR WEST.
TUESDAY NIGHT AND WEDNESDAY...THE BOUNDARY DRIFTS EAST AND
TIGHTENS PRECIPITATION SPREADS ACROSS NEMONT. THE PRECIPITATION
TYPE WILL BE DIFFICULT TO DETERMINE THIS FAR OUT...BUT IT WILL
LIKELY BE RAIN IN THE WEST AND SNOW IN THE NORTHEAST...WITH A
WINTRY MIX IN THE MIDDLE.
KEEPING IN MIND THAT THE MODELS HAVE BEEN GOING IN AND OUT OF
AGREEMENT...TEMPERATURES AND WX HAVE SOME UNCERTAINTY. BUT FOR
NOW SNOW AMOUNTS SUGGEST WINTER HEADLINES FOR THE MIDDLE OF NEXT
WEEK... WITH SNOW AMOUNTS RANGING FROM 1 TO 4 INCHES BY
THANKSGIVING MORNING.
THANKSGIVING DAY...BOTH MODELS SUGGEST ANOTHER COLD WAVE ROUNDING
THE ARCTIC LOW THAT WILL BACKDOOR ANOTHER COLD FRONT INTO NEMONT.
THIS WILL TURN THE PRECIPITATION TO ALL SNOW...MAINLY IN THE
SOUTHWEST PORTION OF THE CWA AND BRING ABOUT COLDER TEMPERATURES.
FRIDAY AND SATURDAY...THE BOUNDARY CONTINUES TO FLUCTUATE BUT WILL
LIKELY KEEP THE MAJORITY OF THE CWA IN THE COLD SECTION. THERE
WILL ALSO BE LESSOR AMOUNTS OF OVERRUNNING MOISTURE FOR ADDITIONAL
LIGHT SNOW.
SCT
PREVIOUS DISCUSSION...
MONDAY NIGHT THROUGH FRIDAY...PERSISTENT UPPER LOW OVER HUDSON
BAY AREA DURING PERIOD. UPPER LEVEL RIDGE OVER PACIFIC NW MONDAY
SLOWLY MOVES INTO NORTHERN ROCKIES AND FLATTENS OUT BY SATURDAY.
RIDGE AND ACCOMPANYING WEST WINDS PROVIDE SEASONABLY PLEASANT
TEMPERATURES TUESDAY.
WEDNESDAY SHORT WAVES SWEEPING DOWN THROUGH NORTHWEST FLOW WILL
BRING CHANCE OF RAIN AND SNOW TO NORTHEAST MONTANA. GFS40 AND
ECMWF/GFS13 BEGIN TO DIVERGE LATER WEDNESDAY HOWEVER. GFS40 DIGS
TROUGH SOUTHWARD ACROSS STATE WHILE ECMWF AND GFS13 TAKE SHORT WAVE
FURTHER EAST. WILL LEAN TOWARD MORE CONSISTENT AND DRIER ECMWF/GFS13
SOLUTIONS. BY THANKSGIVING DAY A RIDGE DEVELOPS OVER MONTANA WITH
A NORTHWEST FLOW ALOFT. EXPECT ONLY SLIGHT CHANCE RAIN AND SNOW
THROUGH REMAINDER OF PERIOD BENEATH WEAK RIDGE. TEMPERATURES WILL BE
SOMEWHAT COOLER AFTER TUESDAY AND WELL BELOW SEASONAL NORMALS.
EXPECT WINDS TO BE RELATIVELY LIGHT THROUGH THE PERIOD. BRITTON
&&
.AVIATION...
A FAST MOVING CLIPPER WILL SWEEP ACROSS THE REGION TONIGHT AND
SUNDAY MORNING. BOTH THE UPPER AND LOWER LEVEL LOWS CLOSE OFF
AND STACK UP OVER SOUTHERN SASKATCHEWAN. THE RESULTING COMPACT
CYCLONE WILL BECOME RATHER EFFICIENT IN PRODUCING VERY STRONG
WINDS TONIGHT AND SUNDAY MORNING OVER NORTHEAST MONTANA. THESE
NORTHWEST WINDS COULD RANGE FROM 20KT TO 30KT WITH GUSTS TO 45KT.
WITH LIGHT SNOW EXPECTED AND EXISTING SNOW ON THE GROUND...
BLOWING SNOW COULD BECOME AN ANOTHER ISSUE AFFECTING VISIBILITY...
ALONG WITH SNOW DRIFTS ACROSS RUNWAYS. WIND WILL TAPER OFF TO
AROUND 15KT SUNDAY AFTERNOON.
THE OTHER FEATURE OF THIS STORM WILL BE LOW-LEVEL OVERCAST...
PRODUCING MVFR/IFR CEILINGS...WITH LIGHT SNOW AT TIMES. WRAP-
AROUND SNOW COULD INCREASE THE CHANCES FOR HEAVIER...MEASURABLE
SNOW ON SUNDAY MORNING...TAPERING OFF IN THE AFTERNOON. ANY
TERMINAL WITH FALLING SNOW COULD TEMPORARILY SEE MVFR/IFR
VISIBILITIES.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 5 PM MST SUNDAY FOR CENTRAL AND
SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...GARFIELD...
MCCONE...PETROLEUM.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 2 PM MST
SUNDAY FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...DANIELS...DAWSON...EASTERN ROOSEVELT...GARFIELD...
MCCONE...NORTHERN PHILLIPS...NORTHERN VALLEY...PRAIRIE...
RICHLAND...SHERIDAN...SOUTHWEST PHILLIPS...WESTERN ROOSEVELT...
WIBAUX.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1200 AM CST SAT NOV 22 2014
.UPDATE...
ISSUED AT 1058 PM CST FRI NOV 21 2014
UPDATED THE FORECAST TONIGHT TO HIT THE FOG HEAVIER AND ADD A
LITTLE DRIZZLE TO MOST OF THE CWA. STRATUS HAS MADE IT FARTHER
NORTH THAN ORIGINALLY FORECAST. HRRR SEEMS TO HAVE A GOOD GRIP ON
THIS AND BEGINS TO MOVE THE STRATUS SOUTHEAST LATE TONIGHT BUT
HANGS ONTO IT IN OUR FAR SOUTHEAST INTO THE MORNING HOURS. THIS
WILL HOLD TEMPS UP DOWN THERE AND I HAVE RAISED LOWS. ANY
DRIZZLE/STRATUS WILL BE ABOVE FREEZING ACCORDING TO THE DEPENDABLE
HRRR AND I HAVE NO REASON TO DOUBT THIS...SO FREEZING DRIZZLE
SHOULD NOT BE A PROBLEM.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 345 PM CST FRI NOV 21 2014
HAVE SEEN QUIET CONDITIONS ACROSS THE CWA TODAY...WITH UPPER AIR
AND SATELLITE IMAGERY SHOWING A WEAK UPPER LEVEL DISTURBANCE
MAKING ITS WAY ACROSS THE REGION...WHILE A STRONGER LOW PRESSURE
SYSTEM SPINS OVER THE DESERT SW. AT THE SFC...THE CWA IS SET UP
BETWEEN HIGH PRESSURE CENTERED OVER THE ERN THIRD OF THE CONUS AND
A TROUGH OF LOW PRESSURE DRAPED THROUGH THE HIGH
PLAINS...RESULTING IN CONTINUED SRLY WINDS. VISIBLE SATELLITE
IMAGERY SHOWS A EXPANSIVE AREA OF LOW LEVEL STRATUS WHICH HAS BEEN
GRADUALLY MAKING ITS WAY NORTH THROUGH THE DAY...AND IN THE PAST
FEW HOURS HAS FINALLY MADE IT INTO THE SRN PORTIONS OF THE CWA.
THE LOWER LEVEL RH FIELDS OF THE RAP/NAM HAVE BEEN HANDLING ITS
PROGRESSION WELL TODAY. TEMPS HAVE WARMED A BIT MORE THAN EXPECTED
TODAY...3 PM OBS RANGE FROM THE LOWER 50S IN THE ODX/LXN/PHG
AREAS...MID TO UPPER 40S CENTRAL AND LOCATIONS EAST ALONG THE
STATE LINE...STILL SOME UPPER 30S IN THE NORTHEAST CORNER.
THROUGH THE OVERNIGHT HOURS TONIGHT INTO THE FIRST PART OF
SATURDAY MORNING...THE MAIN CONCERN IS GOING TO LIE WITH THIS
CLOUD COVER...AND FOG POTENTIAL. WILL STICK CLOSE TO THE NAM/RAP
FOR THE EVOLUTION OF THE LL STRATUS...WHICH KEEPS CREEPING IT
NORTH...THEN GIVES IT A SHOVE OFF TO THE EAST THROUGH THE EVENING
HOURS. EXPECTING LITTLE CHANGE WITH THE OVERALL SFC
PATTERN...WINDS REMAINING SRLY WITH SPEEDS ARND 10 MPH. MODELS
THIS MORNING STARTING SHOWING BETTER POTENTIAL FOR THE DEVELOPMENT
OF FOG...MAINLY ACROSS THE ERN HALF OF THE CWA...AREAS AFFECTED BY
STRATUS TODAY OR ON THE EDGE OF THE STRATUS TONIGHT. MET/MAV/LAV
NOT LENDING MUCH SUPPORT TO LOWER VISIBILITIES OR CEILINGS...BUT
DID INSERT A MENTION OF PATCHY AND AREAS OF FOG...MAINLY AFTER
MIDNIGHT. EVENING CREW WILL BE MONITORING TRENDS CLOSELY...AS
MODELS DEPICTED LOCATIONS OUTSIDE OF THE CWA BEING AFFECT
FIRST...WILL SEE HOW THINGS PLAY OUT.
FOR TOMORROW...OUTSIDE OF THE POSSIBILITY OF SOME LINGERING FOG IN
THE MORNING...DRY CONDITIONS ARE EXPECTED. THAT MAIN UPPER LEVEL
LOW PRESSURE SYSTEM SHIFTS OUT OF THE DESERT SW...BUT BY THE END
OF THE DAY STILL REMAINS WELL SOUTH OF THE CWA IN TX. AM BEING
OPTIMISTIC WITH THE CLOUD COVER DIMINISHING IN THE MORNING...WITH
MOSTLY CLEAR/PARTLY CLOUDY SKIES IN THE AFTERNOON. MODELS REMAIN
IN GOOD AGREEMENT SHOWING WARMER TEMPS /5+ DEGREES/ ALOFT MOVING
INTO THE REGION...AND WINDS ARE EXPECTED TO CONTINUE FROM THE
SOUTH /PERHAPS A TOUCH OF A WRLY COMPONENT/...SATURDAY STILL
LOOKING TO BE THE WARMEST DAY OF THE NEXT SEVERAL. WITH MANY
LOCATIONS EXCEEDING EXPECTATIONS TODAY...DID TREND HIGHS UP A
BIT...NEAR THE MAV GUIDANCE...WHICH BRINGS WIDESPREAD MID
50S...AND READINGS NEAR 60 IN THE FAR S/SWRN PORTIONS OF THE AREA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 PM CST FRI NOV 21 2014
CONTINUED DRY WEATHER IS EXPECTED THROUGH THE EXTENDED PERIODS WITH
TEMPERATURES FLUCTUATING NEAR OR JUST BELOW CLIMATOLOGY THROUGH
NEXT WEDNESDAY...FOLLOWED BY A BRIEF SHOT OF UNSEASONABLY COLD
AIR NEXT THURSDAY...WHICH WILL LIKELY HOLD DOWN HIGH TEMPERATURES
JUST BELOW FREEZING THANKSGIVING AFTERNOON.
LOOKING AT THE BIGGER PICTURE...AN UPPER LEVEL TROUGH CROSSING THE
NORTHERN ROCKIES SATURDAY NIGHT WILL STEER A COLD FRONT ACROSS THE
REGION ON SUNDAY...BRINGING GUSTY NORTHERLY WINDS AND COOLER
TEMPERATURES TO THE AREA TO FINISH OFF THE WEEKEND. WHILE THERE
WILL LIKELY BE SOME MOISTURE POOLING AHEAD OF THIS FRONT ACROSS
SOUTHEASTERN NEBRASKA AND PORTIONS OF KANSAS OVERNIGHT SATURDAY
THROUGH SUNDAY MORNING...OPTED TO KEEP THE FORECAST DRY AS THE NAM
WAS TOO AGGRESSIVE TRYING TO SQUEEZE OUT SOME LIGHT DRIZZLE THIS
MORNING ACROSS OUR LOCAL AREA...AND THINK THAT THIS IS ALSO THE
CASE FOR LATE SATURDAY NIGHT/EARLY SUNDAY MORNING...ESPECIALLY
SINCE THE AXIS OF THIS ACTIVITY IS EVEN FURTHER EAST THAN WHAT WAS
MODELED FOR TODAY. OTHERWISE...DO EXPECT AN INCREASE IN CLOUDS
FROM THE NORTHWEST SUNDAY MORNING WITH THE FRONT...WITH ANY POST
FRONTAL PRECIP EXPECTED TO REMAIN TO THE NORTH AND EAST OF THE
LOCAL AREA.
THE WARMEST DAY OF THE EXTENDED PERIODS IS EXPECTED TO BE SUNDAY
AFTERNOON...WHEN TEMPERATURES ARE EXPECTED TO CLIMB TO NEAR OR JUST
ABOVE CLIMATOLOGY. THEREAFTER...EXPECT PERSISTENT NORTHWESTERLY
FLOW TO CONTINUE ACROSS THE REGION THROUGH MID WEEK AS A RIDGE
OF HIGH PRESSURE STRENGTHENS ALONG THE WEST COAST...WITH THIS
GENERALLY COOL WEATHER PATTERN EXPECTED TO HOLD DOWN TEMPERATURES
IN THE MID 30S TO MID 40S ACROSS THE MUCH OF THE FORECAST AREA
THROUGH WEDNESDAY. AFTER THAT...TEMPERATURES ARE EXPECTED TO TAKE
A BRIEF PLUNGE ON THANKSGIVING DAY AS MODELS ARE KEYING IN ON A
REINFORCING SHOT OF COLD AIR WHICH WILL PLUNGE TEMPERATURES DOWN
10-15F FROM EARLIER IN THE WEEK. THANKFULLY...THE BRUNT OF THIS
COOLER AIRMASS WILL BE FOCUSED FURTHER EAST OF THE LOCAL
AREA...AND TEMPERATURES SHOULD MODERATE AFTER A DAY OR TWO...AS
THE RIDGE OF HIGH PRESSURE ACROSS THE WEST COAST BREAKS DOWN AND
MORE ZONAL FLOW BECOMES ESTABLISHED ALOFT. WHILE INITIALLY WE HAD
SOME SMALL CHANCES FOR SNOW WITH THIS SECONDARY SHOT OF COLD AIR
ON THANKSGIVING DAY...MODELS ARE NOW KEEPING THE AREA DRY AND
COMING INTO BETTER AGREEMENT...AND NO SIGNIFICANT CHANCE OF PRECIP
IS NOW ANTICIPATED THROUGH THE EXTENDED PERIODS.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1155 PM CST FRI NOV 21 2014
THE AVIATION FORECAST IS LOADED WITH CHALLENGES IN THE SHORT TERM
DUE TO A LOW STRATUS BANK THAT JUST PRIOR TO MIDNIGHT HAS BEEN
MEANDERING AROUND BETWEEN KGRI AND KEAR. KGRI IS SOCKED IN UNDER THE
LOW CLOUDS WHILE KEAR IS JUST WEST OF THE CLOUD SHIELD. THESE LOW
CLOUDS WILL CONTINUE TO MEANDER AROUND THE AREA TONIGHT AND THEN
SLIDE FURTHER EAST OF THE AREA...ESPECIALLY AFTER DAY BREAK. IN
ADDITION TO THE LOW CLOUDS...KGRI COULD ALSO SEE VISIBILITY
REDUCTIONS. THE WIND WILL NOT CHANGE MUCH AND WILL GENERALLY RANGE
FROM SOUTH TO SOUTHWEST THROUGH THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...ADP
LONG TERM...ROSSI
AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1100 PM CST FRI NOV 21 2014
.UPDATE...
ISSUED AT 1058 PM CST FRI NOV 21 2014
UPDATED THE FORECAST TONIGHT TO HIT THE FOG HEAVIER AND ADD A
LITTLE DRIZZLE TO MOST OF THE CWA. STRATUS HAS MADE IT FARTHER
NORTH THAN ORIGINALLY FORECAST. HRRR SEEMS TO HAVE A GOOD GRIP ON
THIS AND BEGINS TO MOVE THE STRATUS SOUTHEAST LATE TONIGHT BUT
HANGS ONTO IT IN OUR FAR SOUTHEAST INTO THE MORNING HOURS. THIS
WILL HOLD TEMPS UP DOWN THERE AND I HAVE RAISED LOWS. ANY
DRIZZLE/STRATUS WILL BE ABOVE FREEZING ACCORDING TO THE DEPENDABLE
HRRR AND I HAVE NO REASON TO DOUBT THIS...SO FREEZING DRIZZLE
SHOULD NOT BE A PROBLEM.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 345 PM CST FRI NOV 21 2014
HAVE SEEN QUIET CONDITIONS ACROSS THE CWA TODAY...WITH UPPER AIR
AND SATELLITE IMAGERY SHOWING A WEAK UPPER LEVEL DISTURBANCE
MAKING ITS WAY ACROSS THE REGION...WHILE A STRONGER LOW PRESSURE
SYSTEM SPINS OVER THE DESERT SW. AT THE SFC...THE CWA IS SET UP
BETWEEN HIGH PRESSURE CENTERED OVER THE ERN THIRD OF THE CONUS AND
A TROUGH OF LOW PRESSURE DRAPED THROUGH THE HIGH
PLAINS...RESULTING IN CONTINUED SRLY WINDS. VISIBLE SATELLITE
IMAGERY SHOWS A EXPANSIVE AREA OF LOW LEVEL STRATUS WHICH HAS BEEN
GRADUALLY MAKING ITS WAY NORTH THROUGH THE DAY...AND IN THE PAST
FEW HOURS HAS FINALLY MADE IT INTO THE SRN PORTIONS OF THE CWA.
THE LOWER LEVEL RH FIELDS OF THE RAP/NAM HAVE BEEN HANDLING ITS
PROGRESSION WELL TODAY. TEMPS HAVE WARMED A BIT MORE THAN EXPECTED
TODAY...3 PM OBS RANGE FROM THE LOWER 50S IN THE ODX/LXN/PHG
AREAS...MID TO UPPER 40S CENTRAL AND LOCATIONS EAST ALONG THE
STATE LINE...STILL SOME UPPER 30S IN THE NORTHEAST CORNER.
THROUGH THE OVERNIGHT HOURS TONIGHT INTO THE FIRST PART OF
SATURDAY MORNING...THE MAIN CONCERN IS GOING TO LIE WITH THIS
CLOUD COVER...AND FOG POTENTIAL. WILL STICK CLOSE TO THE NAM/RAP
FOR THE EVOLUTION OF THE LL STRATUS...WHICH KEEPS CREEPING IT
NORTH...THEN GIVES IT A SHOVE OFF TO THE EAST THROUGH THE EVENING
HOURS. EXPECTING LITTLE CHANGE WITH THE OVERALL SFC
PATTERN...WINDS REMAINING SRLY WITH SPEEDS ARND 10 MPH. MODELS
THIS MORNING STARTING SHOWING BETTER POTENTIAL FOR THE DEVELOPMENT
OF FOG...MAINLY ACROSS THE ERN HALF OF THE CWA...AREAS AFFECTED BY
STRATUS TODAY OR ON THE EDGE OF THE STRATUS TONIGHT. MET/MAV/LAV
NOT LENDING MUCH SUPPORT TO LOWER VISIBILITIES OR CEILINGS...BUT
DID INSERT A MENTION OF PATCHY AND AREAS OF FOG...MAINLY AFTER
MIDNIGHT. EVENING CREW WILL BE MONITORING TRENDS CLOSELY...AS
MODELS DEPICTED LOCATIONS OUTSIDE OF THE CWA BEING AFFECT
FIRST...WILL SEE HOW THINGS PLAY OUT.
FOR TOMORROW...OUTSIDE OF THE POSSIBILITY OF SOME LINGERING FOG IN
THE MORNING...DRY CONDITIONS ARE EXPECTED. THAT MAIN UPPER LEVEL
LOW PRESSURE SYSTEM SHIFTS OUT OF THE DESERT SW...BUT BY THE END
OF THE DAY STILL REMAINS WELL SOUTH OF THE CWA IN TX. AM BEING
OPTIMISTIC WITH THE CLOUD COVER DIMINISHING IN THE MORNING...WITH
MOSTLY CLEAR/PARTLY CLOUDY SKIES IN THE AFTERNOON. MODELS REMAIN
IN GOOD AGREEMENT SHOWING WARMER TEMPS /5+ DEGREES/ ALOFT MOVING
INTO THE REGION...AND WINDS ARE EXPECTED TO CONTINUE FROM THE
SOUTH /PERHAPS A TOUCH OF A WRLY COMPONENT/...SATURDAY STILL
LOOKING TO BE THE WARMEST DAY OF THE NEXT SEVERAL. WITH MANY
LOCATIONS EXCEEDING EXPECTATIONS TODAY...DID TREND HIGHS UP A
BIT...NEAR THE MAV GUIDANCE...WHICH BRINGS WIDESPREAD MID
50S...AND READINGS NEAR 60 IN THE FAR S/SWRN PORTIONS OF THE AREA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 PM CST FRI NOV 21 2014
CONTINUED DRY WEATHER IS EXPECTED THROUGH THE EXTENDED PERIODS WITH
TEMPERATURES FLUCTUATING NEAR OR JUST BELOW CLIMATOLOGY THROUGH
NEXT WEDNESDAY...FOLLOWED BY A BRIEF SHOT OF UNSEASONABLY COLD
AIR NEXT THURSDAY...WHICH WILL LIKELY HOLD DOWN HIGH TEMPERATURES
JUST BELOW FREEZING THANKSGIVING AFTERNOON.
LOOKING AT THE BIGGER PICTURE...AN UPPER LEVEL TROUGH CROSSING THE
NORTHERN ROCKIES SATURDAY NIGHT WILL STEER A COLD FRONT ACROSS THE
REGION ON SUNDAY...BRINGING GUSTY NORTHERLY WINDS AND COOLER
TEMPERATURES TO THE AREA TO FINISH OFF THE WEEKEND. WHILE THERE
WILL LIKELY BE SOME MOISTURE POOLING AHEAD OF THIS FRONT ACROSS
SOUTHEASTERN NEBRASKA AND PORTIONS OF KANSAS OVERNIGHT SATURDAY
THROUGH SUNDAY MORNING...OPTED TO KEEP THE FORECAST DRY AS THE NAM
WAS TOO AGGRESSIVE TRYING TO SQUEEZE OUT SOME LIGHT DRIZZLE THIS
MORNING ACROSS OUR LOCAL AREA...AND THINK THAT THIS IS ALSO THE
CASE FOR LATE SATURDAY NIGHT/EARLY SUNDAY MORNING...ESPECIALLY
SINCE THE AXIS OF THIS ACTIVITY IS EVEN FURTHER EAST THAN WHAT WAS
MODELED FOR TODAY. OTHERWISE...DO EXPECT AN INCREASE IN CLOUDS
FROM THE NORTHWEST SUNDAY MORNING WITH THE FRONT...WITH ANY POST
FRONTAL PRECIP EXPECTED TO REMAIN TO THE NORTH AND EAST OF THE
LOCAL AREA.
THE WARMEST DAY OF THE EXTENDED PERIODS IS EXPECTED TO BE SUNDAY
AFTERNOON...WHEN TEMPERATURES ARE EXPECTED TO CLIMB TO NEAR OR JUST
ABOVE CLIMATOLOGY. THEREAFTER...EXPECT PERSISTENT NORTHWESTERLY
FLOW TO CONTINUE ACROSS THE REGION THROUGH MID WEEK AS A RIDGE
OF HIGH PRESSURE STRENGTHENS ALONG THE WEST COAST...WITH THIS
GENERALLY COOL WEATHER PATTERN EXPECTED TO HOLD DOWN TEMPERATURES
IN THE MID 30S TO MID 40S ACROSS THE MUCH OF THE FORECAST AREA
THROUGH WEDNESDAY. AFTER THAT...TEMPERATURES ARE EXPECTED TO TAKE
A BRIEF PLUNGE ON THANKSGIVING DAY AS MODELS ARE KEYING IN ON A
REINFORCING SHOT OF COLD AIR WHICH WILL PLUNGE TEMPERATURES DOWN
10-15F FROM EARLIER IN THE WEEK. THANKFULLY...THE BRUNT OF THIS
COOLER AIRMASS WILL BE FOCUSED FURTHER EAST OF THE LOCAL
AREA...AND TEMPERATURES SHOULD MODERATE AFTER A DAY OR TWO...AS
THE RIDGE OF HIGH PRESSURE ACROSS THE WEST COAST BREAKS DOWN AND
MORE ZONAL FLOW BECOMES ESTABLISHED ALOFT. WHILE INITIALLY WE HAD
SOME SMALL CHANCES FOR SNOW WITH THIS SECONDARY SHOT OF COLD AIR
ON THANKSGIVING DAY...MODELS ARE NOW KEEPING THE AREA DRY AND
COMING INTO BETTER AGREEMENT...AND NO SIGNIFICANT CHANCE OF PRECIP
IS NOW ANTICIPATED THROUGH THE EXTENDED PERIODS.
&&
.AVIATION...(FOR THE 00Z KGRI/KEAR TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 539 PM CST FRI NOV 21 2014
MVFR STATUS WILL BE ON THE BRINK OF REACHING THE
TERMINALS...ESPECIALLY GRI. NUMERICAL MODELS INDICATE THAT STRATUS
WILL STOP JUST SHORT OF THE TERMINALS...COMING UP FROM THE
SOUTH...AND THEN SHOVE OFF TO THE EAST LATE TONIGHT AND INTO
SATURDAY. WIND MAY START WITH AN EAST COMPONENT...BUT VEER SOUTH
TONIGHT...AND WILL STAY LIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...ADP
LONG TERM...ROSSI
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1022 PM EST SUN NOV 23 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE AREA TONIGHT. A COLD FRONT
WILL APPROACH FROM THE WEST MONDAY AND MOVE OFFSHORE TUESDAY
MORNING. LOW PRESSURE WILL FORM ALONG THE FRONT AND MOVE NORTH ALONG
THE FRONT OFF THE NORTH CAROLINA COAST WEDNESDAY. HIGH PRESSURE WILL
BUILD INTO AREA THURSDAY. A WEAK FRONT WILL MOVE THROUGH FRIDAY WITH
HIGH PRESSURE BUILDING IN BEHIND IT. ANOTHER FRONT WILL MOVE THROUGH
SATURDAY NIGHT. HIGH PRESSURE WILL BE OVER THE AREA SUNDAY.
&&
.NEAR TERM /TONIGHT/...
AS OF 10 PM SUN...LATEST SFC ANALYSIS SHOWS WARM FRONT DRAPED
THROUGH NORTHERN SC. THE WARM FRONT WILL CONTINUE TO LIFT NORTH
THROUGH EASTERN NC TONIGHT. TWEAKED FORECAST SLIGHTLY BASED ON
LATEST TRENDS. LATEST RADAR IMAGERY SHOWS SHOWERS WITH EMBEDDED
TSTMS BEGINNING TO OVERSPREAD THE AREA FROM THE SW. MADE
ADJUSTMENTS TO POPS BASED ON HIGH RES MODELS...WITH HRRR DOING A
GOOD JOB HANDLING CURRENT ACTIVITY. STILL LOOKING AT A HIGH
SHEAR/LOW CAPE SETUP OVERNIGHT...WITH 0-6KM SHEAR 50-60KT WITH
LITTLE INSTABILITY. ALTHOUGH IF TIMING IS RIGHT COULD BE ENOUGH TO
SPARK A FEW STRONG TSTMS...ESP WITH INCREASING LOW LEVEL HELICITY
VALUES. WITH STRONG LIFT AND PWAT VALUES NEARING 1.75 INCHES
OVERNIGHT EXPECT PERIODS OF MODERATE TO HEAVY RAIN. MAIN THREATS
TONIGHT WILL CONTINUE TO BE THE POTENTIAL FOR HEAVY
RAIN...ISOLATED DAMAGING WINDS GUSTS AND AN ISOLATED TORNADO. AT
THIS TIME THINK BEST CHANCE FOR ANY SVR WX WILL BE BTWN 11PM-4AM.
WILL CONTINUE TO WATCH INITIAL AREA OF CONVECTION CURRENTLY OVER
COASTAL SE NC MOVING NE WHICH MAY MOVE ACROSS ONSLOW/CARTERET
COUNTIES IN THE NEXT HOUR OR TWO...WITH ADDITIONAL ACTIVITY BEHIND
IT. ALSO CANNOT RULE OUT ISOLATED STRONG CELLS MOVING IN OFF THE
WATERS WITH STRONG SELY FLOW.
EXPECT A NON DIURNAL TEMP CURVE OVERNIGHT...WITH LOWS LIKELY EARLY
IN THE LOW 60S...THEN INCREASING AFTER MIDNIGHT INTO THE
MID/UPPER 60S WITH GUSTY SLY FLOW.
&&
.SHORT TERM /MONDAY/...
AS OF 130 PM SUN...ANOTHER WAVE WILL DIG INTO THE CENTRAL US UPPER
TROUGH MONDAY PUSHING A COLD FRONT TOWARD EASTERN NORTH CAROLINA.
FORECAST SOUNDINGS SHOWING DRYING ABOVE 7H...BUT INSTABILITY AND
PRECIPITABLE WATERS REMAIN ELEVATED FOR A CONTINUED CHANCE OF
PRECIPITATION THROUGH THE DAY AHEAD OF THE ADVANCING COLD FRONT.
WITH DEEP SOUTH TO WEST FLOW...TEMPERATURES EXPECTED TO CLIMB INTO
THE MIDDLE TO UPPER 70S DURING THE AFTERNOON.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
AS OF 215 PM SUN...COLD FRONT WILL CROSS THE REGION MON NIGHT AND
DRIFT OFFSHORE TUE. DESPITE DECENT MOISTURE AHEAD OF THE FRONT
MDLS SHOW VERY LITTLE QPF AS FORCING IS LIMITED MON EVENING SO WL
JUST HAVE SMALL POPS IMD CST. AS FRONT DRIFTS OFF THE CST TUE WILL
CONT SMALL POP CST THRU EARLY AFTN. LATE TUE AS UPR TROF
APPROACHES FROM THE W WILL BEGIN TO SEE SFC LOW FORM WELL TO THE
S AND COULD SEE SOME LIGHT QPF LIFT N INTO THE AREA...WL KEEP POPS
LOW AS TIMING IN DOUBT. WILL REMAIN MILD MON NIGHT WITH LOWS
IN 50S TO NEAR 60 OBX. WEAK CAA TUE WITH HIGHS IN THE LOW TO MID
60S.
WET PERIOD IN STORE TUE NIGHT AND WED AS SFC LOW DEVELOPS TO THE S
TUE NIGHT AND LIFTS NNE NEAR CST WED. STRONG ISENT LIFT ASSOC WITH
THIS SYSTEM WILL LEAD TO WIDESPREAD RAIN DEVELOPING TUE NIGHT AND
CONT THRU THE DAY WED. HAVE CAT POPS MOST AREAS LATE TUE NIGHT AND
WED. N WINDS ON BACKSIDE OF LOW COULD BE QUITE GUSTY AND
TEMPS WILL BE COOL WITH HIGHS 45 TO 50 INLAND AND 50 TO 55 CST.
RAIN SHLD TAPER OFF AND END QUICKLY FROM SW TO NE WED EVENING AS
LOW QUICKLY DEPARTS TO THE NE. DECENT CAA BEHIND THE LOW WITH
TEMPS DROPPING INTO THE 30S MOST AREAS BY THU MORN.
COOL AND DRY WX EXPECTED THU THROUGH THE WEEKEND AS STRONG HIGH
PRES BUILDS IN FROM THE THE W. HIGHS MOSTLY IN THE 50S WITH LOWS
30S INLAND TO 40S BEACHES.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH MONDAY/...
AS OF 7 PM SUN...WIDESPREAD MVFR CONDITIONS CURRENTLY WITH SCT
LIGHT RAIN SHOWERS ACROSS THE AREA. EXPECT CONDITIONS TO CONTINUE
TO DETERIORATE TONIGHT AS WARM FRONT LIFTS THROUGH THE REGION
SHOWER ACTIVITY INCREASES. FORECAST SOUNDINGS/GUIDANCE/NARRE IN GOOD
AGREEMENT SHOWING IFR CEILINGS DEVELOPING BTWN 01-05Z...AND HAVE
MEDIUM TO HIGH CONFIDENCE BASED ON AGREEMENT AND OBS UPSTREAM.
BASED ON HIGH RES MODELS EXPECT PRECIP CHANCES TO INCREASE BTWN
03-06Z...AND ISOLATED TSTM WITH GUSTY WINDS WILL BE POSSIBLE BUT
WILL LEAVE MENTION OUT OF TAFS AT THIS TIME. CIGS COULD LIFT TO
MVFR AFTER PRECIP PUSHES THROUGH 08/09Z BUT WILL CONTINUE IFR. IFR
COULD LINGER INTO LATE MORNING/EARLY AFTERNOON BUT THINK GOOD
SOUTHERLY FLOW SHOULD ALLOW CEILINGS TO LIFT TO MVFR.
LONG TERM /MONDAY NIGHT THROUGH FRI/...
AS OF 215 PM SUN...MAINLY VFR EXPECTED MON NIGHT AND TUE AS COLD
FRONT DRIFTS ACROSS AND STALLS OFFSHORE. RAIN WILL OVERSPREAD THE
REGION TUE NIGHT AND CONT INTO WED...EXPECT WIDESPREAD MAINLY IFR
TO DVLP LATER TUE NIGHT AND CONT INTO WED EVENING. GUSTY NNE WINDS
ALSO EXPECTED ON BACKSIDE OF LOW WED. BY THU HIGH PRESSURE BUILDS
IN AND VFR CONDITIONS RETURN AND SHLD CONT INTO FRI.
&&
.MARINE...
SHORT TERM /THROUGH MONDAY/...
AS OF 10 PM SUN...LATEST OBS SHOW SE WINDS INCREASING TO 20-30KT
WITH GUSTS TO 35KT SOUTH OF HATTERAS. GALE WARNINGS CONTINUE FOR
ALL WATERS. CONDITIONS WILL CONTINUE TO DETERIORATE TONIGHT AS SE
WINDS INCREASE BECOMING SLY 20-30KT WITH GUSTS 35-45KT. SEAS
CURRENTLY RANGING FROM 4-8FT NORTH OF HATTERAS TO 7-13FT SOUTH
WILL CONTINUE TO BUILD...PEAKING AT 7-15FT OVERNIGHT AND EARLY
MONDAY. WARM FRONT EXPECTED TO BE NORTH OF THE WATERS DURING THE
EARLY MORNING HOURS WITH WINDS TURNING TO SOUTHWESTERLY AHEAD OF
AN APPROACHING COLD FRONT.
COLD FRONT WILL APPROACH THE WATERS DURING THE DAY MONDAY. GRADIENT
WILL BE LOOSENING SOME AS THE FRONT GETS CLOSER...ALLOWING
CONDITIONS TO FALL BELOW GALE CRITERION BY MID TO LATE AFTERNOON.
HOWEVER CONDITIONS WILL MOST LIKELY REMAIN IN THE SMALL CRAFT
ADVISORY RANGE THROUGH THE REMAINDER OF THE DAY WITH SOUTHWEST FLOW
AHEAD OF THE APPROACHING COLD FRONT.
LONG TERM /MONDAY NIGHT THROUGH FRI/...
AS OF 205 PM SUN...GUSTY SW WINDS 15 TO 25 KTS WILL CONT AHEAD OF
THE FRONT MON EVENING. WINDS WILL DIMINISH AND VEER TO WRLY LATE
MON NIGHT AS FRONT CROSSES. SEAS OF 6 TO 10 FT MON EVENING WILL
SUBSIDE TO 4 TO 7 FT TOWARD DAYBREAK TUE. WINDS WILL BECOME LIGHT
NW TUE MORN THEN NE 10 TO 15 KTS LATE TUE AS SFC LOW BEGINS TO
FORM TO THE S. SEAS WILL SUBSIDE TO 3 TO 5 FT TUE. AS LOW PRES
DEVELOPS TO THE S TUE NIGHT AND BEGINS TO LIFT N EXPECT NE WINDS
TO INCREASE OVERNIGHT REACHING NEAR 25 KTS BY DAYBREAK WED. AS
WINDS RAMP UP TUE NIGHT SEA WILL BUILD TO 6 TO 7 FEET. MDLS DIFFER
WITH LOW TRACK WED...ECMWF JUST INLAND...GFS NEAR COAST AND
NAM/SREF OFF THE CST. WL NOT CHANGE PREV FCST MUCH WITH MAINLY
JUST OFF CST TRACK KEEPING GUSTY NE TO N WINDS OVER THE REGION.
FOR NOW HAVE STRONG SCA WINDS HOWEVER DEPENDING ON TRACK COULD SEE
SOME GALE CONDITIONS DEVELOP JUST TOO MUCH UNCERTAINTY THIS FAR
OUT. THE STRONG NE WINDS WILL BUILD SEAS TO 8 TO 10 FEET OUTER
WTRS WED. THE LOW WILL DEPART TO THE NE WED NIGHT WITH GUSTY NW
WINDS BECOMING W AND DIMINISHING. SEAS WILL GRAD SUBSIDE TO 4 TO 7
FEET LATE WED NIGHT.
HIGH PRES BUILDING IN FROM THE W WILL LEAD TO WNW WINDS 15 TO 25
KTS THU INTO FRI WITH SEAS OVER OUTER WATERS CONT IN THE 4 TO 6
FOOT RANGE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...GALE WARNING UNTIL 10 AM EST MONDAY FOR AMZ130-131-135>137-150.
GALE WARNING UNTIL 1 PM EST MONDAY FOR AMZ152-154.
GALE WARNING UNTIL 10 AM EST MONDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...CGG
NEAR TERM...CGG/CQD
SHORT TERM...CGG
LONG TERM...RF
AVIATION...RF/CQD
MARINE...CGG/RF/CQD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1008 PM EST SUN NOV 23 2014
.SYNOPSIS...
MILD TEMPERATURES WITH UNSETTLED WEATHER IS EXPECTED TONIGHT INTO
MONDAY AS A WARM FRONT CROSSES THE AREA. A COLD FRONT WILL CROSS
THE COAST MONDAY NIGHT AND STALL OFFSHORE TUESDAY. COOL AND WET
CONDITIONS ARE EXPECTED WEDNESDAY...AS DEEPENING LOW PRESSURE MOVES
NORTH ALONG THE STALLED FRONT AND SKIRTS THE COAST. SKIES WILL
CLEAR OUT ON THANKSGIVING...WITH TEMPERATURES RUNNING SEVERAL
DEGREES BELOW NORMAL INTO THE COMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1000 PM SUNDAY...TWO CONVECTIVE BANDS ARE CROSSING THE AREA
CURRENTLY AND SHOULD DROP A GENERAL 0.4 TO 0.5 INCHES OF RAIN WITH
EMBEDDED HEAVIER AMOUNTS. AT THE SURFACE THE WARM FRONT APPEARS TO
BE THROUGH FLORENCE AND IS APPROACHING MYRTLE BEACH. LATEST HIGH-RES
MODELING INDICATES THE BOUNDARY SHOULD MOVE OR JUMP NORTHWARD VERY
QUICKLY WITH ALL OF OUR FORECAST AREA WITHIN THE WARM SECTOR BY
MIDNIGHT.
CONCERNING SEVERE WEATHER POTENTIAL...INSTABILITY REMAINS THE
LIMITING FACTOR. IN ORDER FOR CONVECTION TO BECOME SURFACE-BASED
ANALYSIS OF THE 03Z SOUNDINGS FROM THE 23Z RUC INDICATES WE NEED A
SURFACE TEMP/DEWPOINT OF 69 DEGREES F...EQUIVALENT TO A SURFACE
THETA-E VALUE OF 333K. ANYTHING LESS THAN THIS SHIFTS THE CONVECTIVE
ORIGIN POINT UPWARD OFF THE SURFACE WITH A CORRESPONDING REDUCTION
IN SEVERE WEATHER RISK. 02/03Z SURFACE OBS INDICATE WE DO NOT HAVE
REQUISITE THETA-E VALUES IN PLACE AT THE SURFACE TO SUPPORT
SURFACE-BASED CONVECTION...AND THEREFORE ALL OF THE CURRENT ACTIVITY
LIKELY REMAINS ELEVATED. THE DRY SLOT IS APPROACHING FROM THE WEST
AND SHOULD SPELL AN END TO THE SOLID PRECIPITATION SHIELD OVER THE
NEXT FEW HOURS...WITH ONLY SCATTERED SHOWERS CONTINUING LATE TONIGHT
INTO MONDAY MORNING. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
A WAVE OF HEAVY SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS EASTERN
GEORGIA AND NOW CROSSING THE SANTEE RIVER INTO SOUTH CAROLINA WILL
MOVE ACROSS THE EASTERN CAROLINAS SHORTLY. RAINFALL EARLIER TODAY
WAS MAINLY DUE TO ISENTROPIC UPGLIDE AS MOIST WARM ADVECTION WITHIN
THE 850-700 MB LAYER PRODUCED GENTLE UNIFORM LIFT. THE BATCH OF
PRECIPITATION TO BEGIN SHORTLY IS BEING FORCED BY EXCELLENT UPPER
DIVERGENCE WITHIN THE RIGHT-ENTRANCE REGION OF A 250 MB JET STREAK
MOVING NORTH THROUGH WESTERN NC/VA THIS EVENING.
A WARM FRONT CURRENTLY EXTENDING FROM NEAR BEAUFORT SC WESTWARD
ACROSS AUGUSTA GA WILL MOVE NORTHWARD AT A GOOD CLIP OVER THE NEXT
FEW HOURS...BRINGING A NEARLY TROPICAL AIRMASS NORTHWARD ACROSS THE
AREA. MODEST SURFACE BASED INSTABILITY ON THE ORDER OF 300-600 J/KG
SHOULD DEVELOP ACROSS AREAS WHERE TEMP/DEWPOINTS ARE ABLE TO REACH
70 DEGREES F. WHEN COMBINED WITH 0-1 KM HELICITY VALUES OF 400-600
M^2/S^2 THE POTENTIAL EXISTS FOR SOME OF THESE CELLS TO ROTATE. I
FEEL THE OVERALL SEVERE WEATHER RISK REMAINS LOW SINCE SURFACE-BASED
INSTABILITY SHOULD NOT DEVELOP UNTIL THE WARM FRONT ARRIVES AND
WINDS BELOW 925 MB VEER MORE SOUTHWESTERLY. THIS WILL MAKE THE
VERTICAL WIND PROFILE UNIDIRECTIONAL REDUCING THE POTENTIAL FOR
TORNADIC STORMS. IF TEMPS/DEWPOINTS REMAIN BELOW 70 F MODEL FORECAST
SOUNDINGS INDICATE THE BOUNDARY LAYER WOULD BE STABLE WITH
CONVECTION REMAINING ELEVATED AND THEREFORE INHERENTLY LESS
DANGEROUS. WE WILL MONITOR RADAR CLOSELY THROUGH THE EVENING
WATCHING FOR ANYTHING THAT MIGHT WARRANT A STATEMENT OR SEVERE
WEATHER WARNING.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...ODDLY MILD CONDITIONS TO ENGULF THE EASTERN
CAROLINAS MONDAY WITH STRONG WARM AIR ADVECTION PATTERN IN PLACE
AND A COLD FRONT AND UPPER TROUGH WEST OF THE FORECAST AREA. 65-70
TEMPERATURE RANGE TO GREET MOST AREAS DAYBREAK MONDAY...AS MAXIMUM
TEMPERATURES CLIMB INTO THE MIDDLE AND UPPER 70S...LIKELY UNDER A
CANOPY OF CLOUDS DUE TO EXTENT OF UPSTREAM CONVECTION. THE LOW-LVL
WIND FIELD REMAINS STRONG MONDAY...AND ANY SURFACE HEATING MONDAY
AFTERNOON COULD LEAD TO CONVECTION CAPABLE OF DAMAGING WIND...AND
EVEN SHOWERS WILL BRING LOCALLY STRONGER GUSTS. SPC MAINTAIN A LOW
END RISK NEAR THE COAST AHEAD OF A COLD FRONT.
TUESDAY A POST-FRONTAL DAY WHERE WEATHER HAZARDS WANE. THE UPSTREAM
TROUGH ALIGN HOWEVER WILL SUPPORT MORE IMPULSES RISING OUT OF THE
GULF. CYCLOGENESIS OFFSHORE OF NORTHERN FLORIDA OCCUR VERY LATE IN
THE PERIOD AND BECOME A WEATHER PLAYER BEYOND DAYBREAK WEDNESDAY AND
POP VALUES DO GRADUALLY RAMP UP TO THIS FEATURE LATE TUESDAY.
RECORD HIGH TEMPS MONDAY ARE ILM 79...FLO 83...CRE 76...LBT 78.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 4 PM SUNDAY...MAIN FOCUS FOR THE PERIOD REMAINS LOW PRESSURE
PASSING JUST OFF THE COAST WED. SHORTWAVE CROSSING THE WESTERN GULF
LATE TUE WILL ENHANCE SURFACE WAVE JUST OFF THE FL GULF COAST WED
MORNING. THIS LOW WILL TRAVEL NORTHEAST ALONG A STALLED BOUNDARY WED
INTO WED NIGHT WITH DEEP MOISTURE SPREADING OVER THE CAROLINAS. LOW
WILL REMAIN EAST OF THE COASTAL WATERS WITH INCREASING NORTHERLY
FLOW...CLOUD COVER...AND PERIODS OF HEAVY RAIN KEEPING TEMPERATURES
IN THE 40S FOR MUCH OF THE AREA. PRESENCE OF DEEP MOISTURE AND
STRONG LIFT/DIVERGENCE ALOFT WILL ENSURE PLENTY OF RAIN FALLS ACROSS
THE AREA WED. MID LEVEL TROUGH MOVES INTO THE AREA WED EVENING WITH
SIGNIFICANT AMOUNT OF DRY AIR MOVING IN...ENDING THE RAIN THREAT.
SUBTLE MID LEVEL TROUGHING IN THE WAKE OF THE EXITING SYSTEM REMAINS
OVER THE SOUTHEAST FRI...PUSHING A DRY COLD FRONT ACROSS THE AREA.
MID LEVEL PATTERN FLATTENS OUT FOR THE WEEKEND AND FLOW ALOFT
BECOMES PROGRESSIVE. HIGH PRESSURE BUILDING IN FOR THE WEEKEND
QUICKLY SHIFTS OFFSHORE WITH RETURN FLOW DEVELOPING AND TEMPS
CLIMBING BACK CLOSE TO CLIMO.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...A MIXTURE OF MVFR/IFR/POSSIBLE LIFR EXPECT TONIGHT AND
THROUGH THE OVERNIGHT HOURS AS UNSETTLED WEATHER ALLOWS FOR
SHRA/TSRA TO CREATE PERIODS OF HEAVY RAIN AND WIND...ALONG WITH LOW
CIGS AND FOG...TO AFFECT THE AREA. RAIN TAPERS OFF INTO THE EARLY
MORNING HOURS...THOUGH AREAS OF LOW CIGS AND FOG ARE ANTICIPATED
THROUGH THE PERIOD...WITH IMPROVEMENT TO VFR POSSIBLE INLAND DURING
THE AFTERNOON HOURS ON MONDAY.
LATEST RADAR IMAGERY DEPICTS LIGHT -SHRA MOVING ACROSS THE AREA THIS
EVENING WHILE OBS ARE REPORTING LOW CIGS AND AREAS OF FOG CREATING
MVFR/IFR AT ALL TAF SITES. WHILE ACTIVITY IS LIGHT NOW...SHOWERS AND
THUNDERSTORMS ARE POSSIBLE LATER TONIGHT INTO THE EARLY OVERNIGHT
HOURS...WITH ISOLATED SEVERE STORMS POSSIBLE. WITH ANY STRONGER
STORM COULD SEE HEAVY RAINFALL. AS FOR WINDS EXPECT SOUTHEASTERLY
AROUND 10 KTS WITH GUSTS UP TO 20 KTS...AND HIGHER GUSTS POSSIBLE IN
ANY TSRA. LATE OVERNIGHT...ANY SHRA/TSRA WILL TAPER OFF...BUT WILL
CONTINUING TO SEE DETERIORATED CONDITIONS AS LOW CIGS AND FOG
PERSISTS. WHILE LIFR CANNOT BE RULE OUT...OVERALL ANTICIPATE
MVFR/IFR. INTO MONDAY...WITH GUSTY SOUTHWEST WINDS...LOW CIGS WITH
AREAS OF FOG WILL PERSIST...THUS EXPECT MVFR/IFR. COULD SEE
IMPROVEMENT TO VFR IN THE AFTERNOON HOURS IN SPOTS...BUT TOWARDS THE
END OF THE PERIOD CONDITIONS WILL DETERIORATE BACK TO MVFR/IFR.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AFTERNOON
THROUGH WEDNESDAY NEAR THE COAST...WITH OCCASIONAL SHOWERS AND
MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY NIGHT...THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM SUNDAY...THE WARM FRONT APPEARS TO BE APPROACHING THE
MYRTLE BEACH VICINITY AS WINDS HAVE SHIFTED IN GEORGETOWN BUT
SOUTHEAST WINDS CONTINUE IN MYRTLE BEACH AND POINTS NORTHWARD ALONG
THE COAST. GUSTS OUT AT THE FRYING PAN SHOALS BUOY REMAIN ABOVE
GALE-FORCE...AND WINDS AT THE BEACHES NORTH OF CAPE FEAR ARE
APPROACHING GALE FORCE WITH 33 KNOTS RECENTLY REPORTED ON TOPSAIL
ISLAND (MESONET) AND 30 KNOTS AT MERCER PIER ON WRIGHTSVILLE BEACH.
SEAS ARE ALMOST FULLY DEVELOPED FOR THIS FETCH AND SPEED...13 FEET
OUT AT FRYING PAN SHOALS...10 FEET AT THE HARBOR BUOY SOUTH OF BALD
HEAD ISLAND...AND 9 FEET AT THE NEARSHORE WRIGHTSVILLE BEACH BUOY.
NO SIGNIFICANT CHANGES ARE NEEDED FOR THIS LATE-EVENING UPDATE.
PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
THE WARM FRONT HAS MOVED THROUGH SAVANNAH AND IS RACING UP THE COAST
AT A PRETTY GOOD CLIP. MOST RECENT MODELS ARE TOO FAST WITH THE
FRONTAL TIMING...BUT AMONG THOSE THAT SEEM TO HAVE A GOOD HANDLE
(21Z HRRR, 22Z RUC, 12Z ECMWF) THE LATEST THINKING IS FOR FRONT TO
CROSS THE SANTEE RIVER 8-9 PM...CAPE FEAR AROUND 11 PM...AND TO BE
NORTH OF TOPSAIL ISLAND BY MIDNIGHT. THE FRONT WILL BE HERALDED BY A
SHIFT FROM SOUTHEAST TO SOUTH WINDS. ANOTHER HEAVY WAVE OF SHOWERS
AND EMBEDDED THUNDERSTORMS IN EASTERN GEORGIA AND NOW CROSSING THE
SAVANNAH RIVER INTO SOUTH CAROLINA SHOULD ARRIVE IN THE NEXT COUPLE
OF HOURS. HEAVY RAINFALL AND LIGHTNING ARE THE LARGEST THREATS.
WINDS HAVE BEEN GUSTING OVER GALE FORCE AT THE FRYING PAN SHOALS
BUOY FOR THE PAST THREE HOURS. BUOY 41004 EAST OF CHARLESTON IS IN
THE SAME ENVIRONMENT AND HAS ALSO GUSTED OVER GALE FORCE EARLY THIS
EVENING. CLOSER TO SHORE THE COLDER OCEAN WATER TEMPERATURE ON THE
SHALLOW CONTINENTAL SHELF IS INDUCED A MUCH MORE STABLE ATMOSPHERIC
BOUNDARY LAYER WITH LESS WIND ABLE TO MIX DOWN FROM ALOFT. DESPITE
WINDS JUST 1000 FEET ABOVE THE SURFACE EXPECTED TO REACH 50 KNOTS
IN JUST A COUPLE HOURS...WIND SPEEDS DOWN AT THE OCEAN SURFACE
SHOULD REMAIN 20-30 KNOTS ACROSS THE SC WATERS...AND 25-35 KNOTS
ACROSS THE NC WATERS WITH A HIGHER GUSTS WELL AWAY FROM SHORE WHERE
WATER TEMPERATURES ARE STILL IN THE RELATIVELY MILD MID 60S.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...MONDAY MARINE CONDITIONS REMAIN DANGEROUS WITH
SEAS OF 5-9 FEET LIKELY AND HIGHEST AWAY FROM SHORE AND NEAR THE
FRYING PAN SHOALS. 20-30 KT SSW WINDS MONDAY...BECOMING WEST LATE
TUESDAY NIGHT OR EARLY MONDAY AS A SURFACE COLD FRONT MOVES ACROSS
THE WATERS. STRONG TSTMS REMAIN POSSIBLE MONDAY THROUGH TUESDAY
MORNING ON THE 0-20 NM WATERS. LARGE SSW-SE WAVES WILL MAKE UP THE
SEA SPECTRUM IN MIXED WAVE PERIODS OF 5-6 SECONDS AND 8-9 SECONDS.
IMPROVING CONDITIONS TUESDAY ALTHOUGH WAVE RECOVERY WILL STILL BE
UNDERWAY EARLY TUESDAY.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 4 PM SUNDAY...PERIOD OF HEADLINES SEEMS LIKELY WED INTO
WED NIGHT AS DEEPENING LOW PRESSURE PASSES JUST EAST OF THE
WATERS. WINDS WILL BACK FROM NORTH-NORTHEAST TO WEST WED INTO WED
NIGHT AS THE LOW LIFTS NORTHEAST. SPEEDS WILL PEAK IN THE 20 TO 25
KT RANGE WITH SEAS NEAR 20 NM FLIRTING WITH 6 TO 7 FT. OFFSHORE
FLOW WEAKENS LATE WED NIGHT INTO THU AS SURFACE HIGH TO THE WEST
BUILDS EAST. SPEEDS REMAIN CLOSE TO 15 KT THU WITH A SLIGHT
INCREASE FRI AS DRY COLD FRONT PASSES AND BRIEF COLD ADVECTION
DEVELOPS. AN OFFSHORE COMPONENT WILL KEEP SEAS WITHIN 20 NM IN THE
2 TO 4 FT RANGE THU AND FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ254-256.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST TUESDAY
FOR AMZ250-252.
GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR AMZ250-252.
&&
$$
SYNOPSIS...MJC/TRA
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...III
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
705 AM EST SAT NOV 22 2014
.SYNOPSIS...HIGH PRESSURE REMAINS OVER THE REGION TODAY INTO
TONIGHT. A STRONG LOW PRESSURE MOVING FROM THE SOUTHERN PLAINS INTO
THE GREAT LAKES SUNDAY WILL SPREAD MOISTURE OVER THE REGION DURING
THE DAY ON SUNDAY. ANOTHER COLD FRONT WILL MOVE EAST ACROSS MUCH OF
THE AREA MONDAY...WITH LOW PRESSURE MOVING ALONG THE SOUTHEAST COAST
TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SATURDAY...
THE LATEST SURFACE ANALYSIS SHOWED SURFACE HIGH PRESSURE OVER
CENTRAL NORTH CAROLINA...AND THE 00Z UPPER-AIR ANALYSIS NOTED VERY
DRY AIR AT 850MB WITH DEW POINT DEPRESSIONS WELL ABOVE 40C. THE
TEMPERATURE HAD FALLEN INTO THE UPPER TEENS AT LEAST AT KTDF...AND
WATCHING THE KRDU OVERNIGHT LOW SO FAR THE LOW WAS 25 AS OF THIS
WRITING. FOR TODAY...BUFR SOUNDINGS ARE CONTINUED DRY AND STABLE.
THE HRRR WRF FORECASTS NOTICEABLE HIGH CLOUDS TODAY...BUT OTHER
GUIDANCE SUCH AS THE CANADIAN CLOUD COVER MODEL...AND WHAT ONE WOULD
CONSIDER LOOKING AT THE UPPER-LEVEL RELATIVE HUMIDITY FORECASTS AND
BUFR SOUNDINGS...SUGGEST LESS. SATELLITE DATA UPSTREAM SUGGEST LESS
AS WELL...ALONG WITH THE JET LIFTING NORTH. UNDER EXPECTED SUNSHINE
HIGHS SHOULD BE 50 TO 55.
OVERNIGHT...CLOUDS SHOULD GRADUALLY INCREASE...BUT IT MAY BE A SLOW
INCREASE AS THE AIR MASS REMAINS DRY IN THE MEAN AT LEAST THROUGH
06Z MONDAY...AND MOISTURE ALOFT DOES NOT SHOW A STRONG INCREASE ON
BUFR SOUNDINGS UNTIL LATE TONIGHT. THE CANADIAN CLOUD COVER MODEL
ALSO SHOWS A SLOW AND GRADUAL INCREASE...AND EVEN A FEW AREAS OF
MOSTLY CLEAR TO PARTLY CLOUDY CONDITIONS ESPECIALLY NORTHEAST EVEN
LATE TONIGHT. OVERNIGHT LOWS WILL BE FORECAST ON THE COLD SIDE OF
GUIDANCE AND A FEW OF THESE LOWS MAY EVEN BE TOO HIGH IF LESS CLOUDS
OCCUR FOR LONGER PERIODS IN THE OVERNIGHT. UNDER THE WESTWARD
EXTENSION OF THE RIDGE...WINDS SHOULD BE LIGHT FOR MUCH OF THE NIGHT.
WILL KEEP A DRY FORECAST AS BOTH THE GFS AND NAM SEEM TO BE A LITTLE
SLOWER WITH THE APPROACH OF DEEPER MOISTURE. BY 12Z SUNDAY...THE NAM
IS FAIRLY MOIST ALOFT...BUT THE SUB-CLOUD LAYER REMAINS VERY DRY.
THE 850MB THETA-E GRADIENT IS JUST BEGINNING TO APPROACH CENTRAL
NORTH CAROLINA ON BOTH THE NAM AND GFS AT 12Z SUNDAY...AND THOSE
MODELS ARE ALSO SUBSIDENT AT THAT LAYER AT THAT TIME. DESPITE THE
DRY SUB-CLOUD LAYER...IF ANY PRECIPITATION WOULD OCCUR OVER THE FAR
SOUTHWEST PIEDMONT...FOR EXAMPLE...SUFFICIENT WARMING ALOFT PUSHES
THICKNESSES WELL INTO THE LIQUID CATEGORY...AND SURFACE WET BULB
TEMPERATURES ARE ABOVE FREEZING. IF ANYTHING DOES OCCUR...IT WOULD
BE VERY CLOSE TO 12Z SUNDAY AND THEN ALMOST CERTAINLY IN THE FORM OF
SPRINKLES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
THE NAM AND THE GFS ARE SLOW TO BRING IN GOOD LIFT TO CENTRAL NORTH
CAROLINA SUNDAY. HOWEVER...NUMEROUS PARAMETERS...INCLUDING 850MB
THETA-E...K INDICES...GENERAL 850MB LIFT...700MB VORTICITY...AMONG
OTHERS SUGGEST THAT PRECIPITATION WILL MOVE IN FROM THE SOUTHWEST
WITH THE GREATEST LIKELIHOOD OF RAIN IN CENTRAL NORTH CAROLINA FROM
ABOUT 18Z TO 05Z. HAVE CONFINED THE HIGHEST CHANCES IN THE GRIDDED
FORECAST FROM 20Z TO 04Z...AND SOME OF THE WRF GUIDANCE IS EVEN
SLOWER THAN THAT WITH THE ONSET PARTICULARLY FROM THE TRIANGLE NORTH
AND EAST. FUTURE FORECASTS MAY END UP TRENDING A LITTLE SLOWER...BUT
FOR PLANNING PURPOSES ANTICIPATE HIGH PROBABILITIES OF RAIN DURING
THE AFOREMENTIONED WINDOW.
CLOUDS SHOULD INCREASE...THOUGH THE UNCERTAINTY WITH THE ONSET OF
RAIN MAKES THE TEMPERATURE FORECAST CHALLENGING. EXCEPT IN THE
TRIAD...GUIDANCE HIGHS ARE RELATIVELY CLOSE...AND WILL PLAN TO GO
BETWEEN THERE. IF RAIN WOULD MOVE IN EARLIER...WOULD ALMOST
CERTAINLY LEAN TOWARD THE COOLER NAM BUT WITH SOME WRF GUIDANCE VOID
OF MUCH PRECIPITATION EVEN TO 18Z SUNDAY THINK AT LEAST A BLEND IS
WISE. IN TERMS OF THUNDER...BUFR SOUNDINGS PROVIDE FOR GREATEST
LAPSE RATES VERY LATE SUNDAY AFTERNOON THROUGH THE EVENING IN
ADVANCE OF A DRY SLOT WHICH BOTH THE NAM AND GFS BUFR SOUNDINGS
FORECAST MOVING IN FROM THE SOUTHWEST DURING THE NIGHT WITH
INCREASING 850MB SUBSIDENCE. 1000-500MB MUCAPE ON THE GFS IS LESS
THAN 200J/KG AND THE SHERBS3 IS LESS THAN ONE...BUT THE NAM IS
NOTICEABLY MORE UNSTABLE...ALTHOUGH IT IS DIFFICULT TO SEE SURFACE-
BASED CONCERNS ON THE NAM BUFR SOUNDINGS WITH A SLIGHT INVERSION
JUST OFF OF THE SURFACE. 0-3KM SHEAR AND HELICITY...AS EXPECTED...
ARE VERY HIGH AS WINDS JUST OFF OF THE SURFACE INCREASE GREATLY.
ADDED A SLIGHT CHANCE OF THUNDER DURING SUNDAY EVENING TO THE
FORECAST FOR THE INTERSTATE 95 CORRIDOR AS AT LEAST THERE IS A
SLIGHT CHANCE OF AT LEAST ELEVATED THUNDER...AND FOR THE HWO WILL
LIKELY ADD A MENTION OF AT LEAST WIND GUSTS TO 40MPH OR A LITTLE
HIGHER AS EVEN SHOWERS IN A RAPIDLY TIGHTENING SURFACE GRADIENT...
WITH 925MB WINDS APPROACHING 50KT...SHOULD RESULT IN A FEW QUITE
NOTICEABLE WIND GUSTS SIMPLY WITH PRECIPITATION. SPC HAS NOTED A
SLIGHT RISK OF SEVERE WEATHER WHERE THUNDER WILL BE ADDED TO THE
FORECAST AND WILL CERTAINLY NEED TO BE WATCHFUL OF INSTABILITY
TRENDS IN LATER FORECASTS...AS OTHER PARAMETERS ARE PLENTY HIGH
ENOUGH FOR ISOLATED SEVERE WEATHER. OVERNIGHT LOWS SUNDAY NIGHT NOT
MUCH DIFFERENT FROM THE HIGHS SUNDAY...STEADY TO RISING IN THE TRIAD
AND MAYBE A DIFFERENCE OF A DEGREE OR TWO ELSEWHERE IN GENERAL. -DJF
MONDAY AND MONDAY NIGHT...MID-LEVEL DRY AIR INTRUSION AND SUBSIDENCE
IN THE WAKE OF THE EXITING SHORTWAVE LIFTING OFF TO THE NORTH WILL
RESULT IN MOSTLY DRY CONDITIONS DURING THE DAY ON MONDAY. THE
TRAILING COLD FRONT WILL TRAVERSE THE AREA MONDAY EVENING/NIGHT BUT
AIRMASS IS JUST TOO DRY WITH LITTLE TO NO FORCING/LIFT ALOFT TO
SUPPORT POPS. TEMPERATURES MONDAY AFTERNOON IN THE PRE-FRONTAL WARM
SECTOR WILL WARM INTO THE UPPER 60S/NEAR 70 NW TO MID 70S SE. LOWS
MONDAY NIGHT WILL RANGE FROM LOWER 40S NW TO LOWER 50S SE AS CAA
SPREADS WEST TO EAST. -CBL
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
TUESDAY THROUGH WEDNESDAY: SOUTHERN STREAM TROUGH EMBEDDED AT THE
BASE OF THE AMPLIFYING LONG WAVE TROUGH WILL TRAVERSE THE GULF COAST
REGION ON TUESDAY AND THEN ACROSS THE SOUTHEAST ON WEDNESDAY. AFTER
A DRY START TO THE DAY ON TUESDAY...RAIN CHANCES WILL RETURN TUESDAY
EVENING/NIGHT AND INTO THE DAY ON WEDNESDAY AS WESTERN EDGE OF
DEEPER MOISTURE AXIS ATTENDANT TO OFFSHORE FRONTAL ZONE RETREATS
INLAND IN RESPONSE TO STRONG DPVA AND UPPER LEVEL DIVERGENCE WITHIN
THE RIGHT ENTRANCE REGION OF A 140-150KT JETSTREAK. BOTH THE GFS AND
EC CONTINUE TO TREND WETTER DURING THIS PERIOD WITH THE POTENTIAL
FOR CENTRAL AND EASTERN PORTIONS OF THE STATE TO RECEIVE SIGNIFICANT
RAINFALL. AS SUCH... WILL RAISE POPS TO CHANCE IN THE WEST TO LIKELY
IN THE EAST. NO P-TYPE ISSUES HERE WITH JUST A COLD RAIN FOR CENTRAL
NC. LOWS TUESDAY NIGHT IN THE MID/UPPER 30 NW TO LOWER 40S SE. HIGHS
WEDNESDAY IN THE 40S. PRECIP AND CLOUDS PULL OUT WEDNESDAY
EVENING/NIGHT WITH LOWS BACK DOWN INTO THE 30S.
THURSDAY AND FRIDAY: UNCERTAINTY REMAINS HIGH REGARDING THE APPROACH
OF THE NEXT BATCH OF SHORTWAVE ENERGY ROTATING EASTWARD WITHIN THE
BASE OF THE LONGWAVE TROUGH...WITH SOME GUIDANCE SUGGESTING A MID-
LEVEL SHORT WAVE MAY TRY TO CLOSE OFF OVER THE MID-ATLANTIC OR
CAROLINAS. ITS WORTH NOTING THAT NORTHERN STREAM SYSTEMS LIKE THIS
ARE OFTEN MOISTURE-STARVED... ESPECIALLY EAST OF THE MOUNTAINS.
GIVEN THERE HAS BEEN LITTLE CONTINUITY AMONG THE DETERMINISTIC
GUIDANCE ALONG WITH LARGE SPREAD AMONG THE ENSEMBLE MEMBERS...WILL
PLAY THE CONSERVATIVE APPROACH AND MAINTAIN A DRY FORECAST FOR
THURSDAY AND FRIDAY. IT LOOKS ALMOST CERTAIN HOWEVER THAT THIS
SYSTEM WILL DELIVER ANOTHER SHOT OF COLD ARCTIC AIR INTO THE
SOUTHEAST BY THE LATE WEEK AND INTO NEXT WEEKEND.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 705 AM SATURDAY...
FOR THE 12Z VALID TAF PERIOD...VFR CONDITIONS CONTINUE. LIGHT WINDS
THIS MORNING GRADUALLY VEER WITH A SLIGHT INCREASE IN WIND SPEEDS
AFTER SUNRISE...WITH SUSTAINED VALUES EXPECTED TO BE UNDER 10KT.
SURFACE WINDS UNDER HIGH PRESSURE BECOME LIGHT OR CALM AGAIN THIS
EVENING BACKING SLIGHTLY.
BEYOND THE 12Z VALID TAF PERIOD...CONDITIONS DETERIORATE SUNDAY AND
AS AREAS OF RAIN MOVE IN TO CENTRAL NORTH CAROLINA NUMEROUS AREAS OF
SUB-VFR...LIKELY IFR...CONDITIONS DEVELOP DURING THE DAY...
ESPECIALLY LATER IN THE DAY...CONTINUING AT LEAST INTO SUNDAY
EVENING. WINDS OFF OF THE SURFACE WILL ALSO INCREASE SUNDAY AND BY
SUNDAY NIGHT REACH OR EVEN EXCEED 50KT BY 2000FT WHICH COULD MAKE
LOW-LEVEL WIND SHEAR A PROBLEM BY LATE IN THE DAY INTO THE OVERNIGHT
HOURS. IMPROVING AVIATION CONDITIONS ARE POSSIBLE MONDAY AND WHILE
SOUTHWEST WINDS OFF THE SURFACE WILL NOT BE AS STRONG...A GUSTY
CHARACTER TO THE SURFACE WINDS CONTINUES. AS LOW PRESSURE MOVES
ALONG THE SOUTHEAST COAST TUESDAY INTO WEDNESDAY...UNCERTAINTY
INCREASES IN TERMS OF THE POTENTIAL FOR A RETURN TO A PERIOD OF SUB-
VFR CONDITIONS AND PRECIPITATION...ESPECIALLY EAST OF THE TRIAD. THE
NAM MODEL RETURNS THESE CONDITIONS MUCH FASTER TUESDAY...WHILE THE
GFS AND ECMWF ARE SLOWER...MORE OVERNIGHT TUESDAY INTO WEDNESDAY.
THE CURRENT THINKING IS TOWARD THE SLOWER SOLUTIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF/CBL
LONG TERM...CBL
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EST SAT NOV 22 2014
.SYNOPSIS...HIGH PRESSURE REMAINS OVER THE REGION TODAY INTO
TONIGHT. A STRONG LOW PRESSURE MOVING FROM THE SOUTHERN PLAINS INTO
THE GREAT LAKES SUNDAY WILL SPREAD MOISTURE OVER THE REGION DURING
THE DAY ON SUNDAY. ANOTHER COLD FRONT WILL MOVE EAST ACROSS MUCH OF
THE AREA MONDAY...WITH LOW PRESSURE MOVING ALONG THE SOUTHEAST COAST
TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SATURDAY...
THE LATEST SURFACE ANALYSIS SHOWED SURFACE HIGH PRESSURE OVER
CENTRAL NORTH CAROLINA...AND THE 00Z UPPER-AIR ANALYSIS NOTED VERY
DRY AIR AT 850MB WITH DEW POINT DEPRESSIONS WELL ABOVE 40C. THE
TEMPERATURE HAD FALLEN INTO THE UPPER TEENS AT LEAST AT KTDF...AND
WATCHING THE KRDU OVERNIGHT LOW SO FAR THE LOW WAS 25 AS OF THIS
WRITING. FOR TODAY...BUFR SOUNDINGS ARE CONTINUED DRY AND STABLE.
THE HRRR WRF FORECASTS NOTICEABLE HIGH CLOUDS TODAY...BUT OTHER
GUIDANCE SUCH AS THE CANADIAN CLOUD COVER MODEL...AND WHAT ONE WOULD
CONSIDER LOOKING AT THE UPPER-LEVEL RELATIVE HUMIDITY FORECASTS AND
BUFR SOUNDINGS...SUGGEST LESS. SATELLITE DATA UPSTREAM SUGGEST LESS
AS WELL...ALONG WITH THE JET LIFTING NORTH. UNDER EXPECTED SUNSHINE
HIGHS SHOULD BE 50 TO 55.
OVERNIGHT...CLOUDS SHOULD GRADUALLY INCREASE...BUT IT MAY BE A SLOW
INCREASE AS THE AIR MASS REMAINS DRY IN THE MEAN AT LEAST THROUGH
06Z MONDAY...AND MOISTURE ALOFT DOES NOT SHOW A STRONG INCREASE ON
BUFR SOUNDINGS UNTIL LATE TONIGHT. THE CANADIAN CLOUD COVER MODEL
ALSO SHOWS A SLOW AND GRADUAL INCREASE...AND EVEN A FEW AREAS OF
MOSTLY CLEAR TO PARTLY CLOUDY CONDITIONS ESPECIALLY NORTHEAST EVEN
LATE TONIGHT. OVERNIGHT LOWS WILL BE FORECAST ON THE COLD SIDE OF
GUIDANCE AND A FEW OF THESE LOWS MAY EVEN BE TOO HIGH IF LESS CLOUDS
OCCUR FOR LONGER PERIODS IN THE OVERNIGHT. UNDER THE WESTWARD
EXTENSION OF THE RIDGE...WINDS SHOULD BE LIGHT FOR MUCH OF THE NIGHT.
WILL KEEP A DRY FORECAST AS BOTH THE GFS AND NAM SEEM TO BE A LITTLE
SLOWER WITH THE APPROACH OF DEEPER MOISTURE. BY 12Z SUNDAY...THE NAM
IS FAIRLY MOIST ALOFT...BUT THE SUB-CLOUD LAYER REMAINS VERY DRY.
THE 850MB THETA-E GRADIENT IS JUST BEGINNING TO APPROACH CENTRAL
NORTH CAROLINA ON BOTH THE NAM AND GFS AT 12Z SUNDAY...AND THOSE
MODELS ARE ALSO SUBSIDENT AT THAT LAYER AT THAT TIME. DESPITE THE
DRY SUB-CLOUD LAYER...IF ANY PRECIPITATION WOULD OCCUR OVER THE FAR
SOUTHWEST PIEDMONT...FOR EXAMPLE...SUFFICIENT WARMING ALOFT PUSHES
THICKNESSES WELL INTO THE LIQUID CATEGORY...AND SURFACE WET BULB
TEMPERATURES ARE ABOVE FREEZING. IF ANYTHING DOES OCCUR...IT WOULD
BE VERY CLOSE TO 12Z SUNDAY AND THEN ALMOST CERTAINLY IN THE FORM OF
SPRINKLES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
THE NAM AND THE GFS ARE SLOW TO BRING IN GOOD LIFT TO CENTRAL NORTH
CAROLINA SUNDAY. HOWEVER...NUMEROUS PARAMETERS...INCLUDING 850MB
THETA-E...K INDICES...GENERAL 850MB LIFT...700MB VORTICITY...AMONG
OTHERS SUGGEST THAT PRECIPITATION WILL MOVE IN FROM THE SOUTHWEST
WITH THE GREATEST LIKELIHOOD OF RAIN IN CENTRAL NORTH CAROLINA FROM
ABOUT 18Z TO 05Z. HAVE CONFINED THE HIGHEST CHANCES IN THE GRIDDED
FORECAST FROM 20Z TO 04Z...AND SOME OF THE WRF GUIDANCE IS EVEN
SLOWER THAN THAT WITH THE ONSET PARTICULARLY FROM THE TRIANGLE NORTH
AND EAST. FUTURE FORECASTS MAY END UP TRENDING A LITTLE SLOWER...BUT
FOR PLANNING PURPOSES ANTICIPATE HIGH PROBABILITIES OF RAIN DURING
THE AFOREMENTIONED WINDOW.
CLOUDS SHOULD INCREASE...THOUGH THE UNCERTAINTY WITH THE ONSET OF
RAIN MAKES THE TEMPERATURE FORECAST CHALLENGING. EXCEPT IN THE
TRIAD...GUIDANCE HIGHS ARE RELATIVELY CLOSE...AND WILL PLAN TO GO
BETWEEN THERE. IF RAIN WOULD MOVE IN EARLIER...WOULD ALMOST
CERTAINLY LEAN TOWARD THE COOLER NAM BUT WITH SOME WRF GUIDANCE VOID
OF MUCH PRECIPITATION EVEN TO 18Z SUNDAY THINK AT LEAST A BLEND IS
WISE. IN TERMS OF THUNDER...BUFR SOUNDINGS PROVIDE FOR GREATEST
LAPSE RATES VERY LATE SUNDAY AFTERNOON THROUGH THE EVENING IN
ADVANCE OF A DRY SLOT WHICH BOTH THE NAM AND GFS BUFR SOUNDINGS
FORECAST MOVING IN FROM THE SOUTHWEST DURING THE NIGHT WITH
INCREASING 850MB SUBSIDENCE. 1000-500MB MUCAPE ON THE GFS IS LESS
THAN 200J/KG AND THE SHERBS3 IS LESS THAN ONE...BUT THE NAM IS
NOTICEABLY MORE UNSTABLE...ALTHOUGH IT IS DIFFICULT TO SEE SURFACE-
BASED CONCERNS ON THE NAM BUFR SOUNDINGS WITH A SLIGHT INVERSION
JUST OFF OF THE SURFACE. 0-3KM SHEAR AND HELICITY...AS EXPECTED...
ARE VERY HIGH AS WINDS JUST OFF OF THE SURFACE INCREASE GREATLY.
ADDED A SLIGHT CHANCE OF THUNDER DURING SUNDAY EVENING TO THE
FORECAST FOR THE INTERSTATE 95 CORRIDOR AS AT LEAST THERE IS A
SLIGHT CHANCE OF AT LEAST ELEVATED THUNDER...AND FOR THE HWO WILL
LIKELY ADD A MENTION OF AT LEAST WIND GUSTS TO 40MPH OR A LITTLE
HIGHER AS EVEN SHOWERS IN A RAPIDLY TIGHTENING SURFACE GRADIENT...
WITH 925MB WINDS APPROACHING 50KT...SHOULD RESULT IN A FEW QUITE
NOTICEABLE WIND GUSTS SIMPLY WITH PRECIPITATION. SPC HAS NOTED A
SLIGHT RISK OF SEVERE WEATHER WHERE THUNDER WILL BE ADDED TO THE
FORECAST AND WILL CERTAINLY NEED TO BE WATCHFUL OF INSTABILITY
TRENDS IN LATER FORECASTS...AS OTHER PARAMETERS ARE PLENTY HIGH
ENOUGH FOR ISOLATED SEVERE WEATHER. OVERNIGHT LOWS SUNDAY NIGHT NOT
MUCH DIFFERENT FROM THE HIGHS SUNDAY...STEADY TO RISING IN THE TRIAD
AND MAYBE A DIFFERENCE OF A DEGREE OR TWO ELSEWHERE IN GENERAL. -DJF
MONDAY AND MONDAY NIGHT...MID-LEVEL DRY AIR INTRUSION AND SUBSIDENCE
IN THE WAKE OF THE EXITING SHORTWAVE LIFTING OFF TO THE NORTH WILL
RESULT IN MOSTLY DRY CONDITIONS DURING THE DAY ON MONDAY. THE
TRAILING COLD FRONT WILL TRAVERSE THE AREA MONDAY EVENING/NIGHT BUT
AIRMASS IS JUST TOO DRY WITH LITTLE TO NO FORCING/LIFT ALOFT TO
SUPPORT POPS. TEMPERATURES MONDAY AFTERNOON IN THE PRE-FRONTAL WARM
SECTOR WILL WARM INTO THE UPPER 60S/NEAR 70 NW TO MID 70S SE. LOWS
MONDAY NIGHT WILL RANGE FROM LOWER 40S NW TO LOWER 50S SE AS CAA
SPREADS WEST TO EAST. -CBL
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
TUESDAY THROUGH WEDNESDAY: SOUTHERN STREAM TROUGH EMBEDDED AT THE
BASE OF THE AMPLIFYING LONG WAVE TROUGH WILL TRAVERSE THE GULF COAST
REGION ON TUESDAY AND THEN ACROSS THE SOUTHEAST ON WEDNESDAY. AFTER
A DRY START TO THE DAY ON TUESDAY...RAIN CHANCES WILL RETURN TUESDAY
EVENING/NIGHT AND INTO THE DAY ON WEDNESDAY AS WESTERN EDGE OF
DEEPER MOISTURE AXIS ATTENDANT TO OFFSHORE FRONTAL ZONE RETREATS
INLAND IN RESPONSE TO STRONG DPVA AND UPPER LEVEL DIVERGENCE WITHIN
THE RIGHT ENTRANCE REGION OF A 140-150KT JETSTREAK. BOTH THE GFS AND
EC CONTINUE TO TREND WETTER DURING THIS PERIOD WITH THE POTENTIAL
FOR CENTRAL AND EASTERN PORTIONS OF THE STATE TO RECEIVE SIGNIFICANT
RAINFALL. AS SUCH... WILL RAISE POPS TO CHANCE IN THE WEST TO LIKELY
IN THE EAST. NO P-TYPE ISSUES HERE WITH JUST A COLD RAIN FOR CENTRAL
NC. LOWS TUESDAY NIGHT IN THE MID/UPPER 30 NW TO LOWER 40S SE. HIGHS
WEDNESDAY IN THE 40S. PRECIP AND CLOUDS PULL OUT WEDNESDAY
EVENING/NIGHT WITH LOWS BACK DOWN INTO THE 30S.
THURSDAY AND FRIDAY: UNCERTAINTY REMAINS HIGH REGARDING THE APPROACH
OF THE NEXT BATCH OF SHORTWAVE ENERGY ROTATING EASTWARD WITHIN THE
BASE OF THE LONGWAVE TROUGH...WITH SOME GUIDANCE SUGGESTING A MID-
LEVEL SHORT WAVE MAY TRY TO CLOSE OFF OVER THE MID-ATLANTIC OR
CAROLINAS. ITS WORTH NOTING THAT NORTHERN STREAM SYSTEMS LIKE THIS
ARE OFTEN MOISTURE-STARVED... ESPECIALLY EAST OF THE MOUNTAINS.
GIVEN THERE HAS BEEN LITTLE CONTINUITY AMONG THE DETERMINISTIC
GUIDANCE ALONG WITH LARGE SPREAD AMONG THE ENSEMBLE MEMBERS...WILL
PLAY THE CONSERVATIVE APPROACH AND MAINTAIN A DRY FORECAST FOR
THURSDAY AND FRIDAY. IT LOOKS ALMOST CERTAIN HOWEVER THAT THIS
SYSTEM WILL DELIVER ANOTHER SHOT OF COLD ARCTIC AIR INTO THE
SOUTHEAST BY THE LATE WEEK AND INTO NEXT WEEKEND.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1250 AM SATURDAY...
FOR THE 06Z VALID TAF PERIOD...VFR CONDITIONS CONTINUE. LIGHT WINDS
THIS MORNING GRADUALLY VEER WITH A SLIGHT INCREASE IN WIND SPEEDS
AFTER SUNRISE...WITH SUSTAINED VALUES EXPECTED TO BE UNDER 10KT.
SURFACE WINDS UNDER HIGH PRESSURE BECOME LIGHT OR CALM AGAIN THIS
EVENING BACKING SLIGHTLY.
BEYOND THE 06Z VALID TAF PERIOD...CONDITIONS DETERIORATE SUNDAY AND
AS AREAS OF RAIN MOVE IN TO CENTRAL NORTH CAROLINA NUMEROUS AREAS OF
SUB-VFR...LIKELY IFR...CONDITIONS DEVELOP DURING THE DAY CONTINUING
AT LEAST INTO SUNDAY EVENING. WINDS OFF OF THE SURFACE WILL ALSO
INCREASE SUNDAY AND REACH OR EVEN EXCEED 50KT BY 2000FT WHICH COULD
MAKE LOW-LEVEL WIND SHEAR A PROBLEM BY LATE IN THE DAY INTO THE
OVERNIGHT HOURS. IMPROVING AVIATION CONDITIONS ARE POSSIBLE MONDAY
AND WHILE SOUTHWEST WINDS OFF THE SURFACE WILL NOT BE AS STRONG...A
GUSTY CHARACTER TO THE SURFACE WINDS CONTINUES. AS LOW PRESSURE
MOVES ALONG THE SOUTHEAST COAST TUESDAY INTO WEDNESDAY...UNCERTAINTY
INCREASES IN TERMS OF THE POTENTIAL FOR A RETURN TO A PERIOD OF SUB-
VFR CONDITIONS AND PRECIPITATION...ESPECIALLY EAST OF THE TRIAD. THE
NAM MODEL RETURNS THESE CONDITIONS MUCH FASTER TUESDAY...WHILE THE
GFS AND ECMWF ARE SLOWER...MORE OVERNIGHT TUESDAY INTO WEDNESDAY.
THE CURRENT THINKING IS TOWARD THE SLOWER SOLUTIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF/CBL
LONG TERM...CBL
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1153 PM CST FRI NOV 21 2014
.UPDATE...
ISSUED AT 1153 PM CST FRI NOV 21 2014
MADE SOME FURTHER TWEAKS TO CLOUDS AS MOST OF THE STRATUS MOVING
INTO THE NORTH HAS NOT HAD A HUGE SOUTHWARD PUSH AS OF YET. TEMPS
HAVE STAYED MILD AND SOME SPOTS ARE EVEN SEEING SOME DOWNSLOPE
WARMING. THIS INFLUENCE SHOULD WANE AS WINDS LIGHTEN.
UPDATE ISSUED AT 956 PM CST FRI NOV 21 2014
ADJUSTED CLOUD COVER A BIT FOR TIMING OF STRATUS COMING DOWN OUT
OF CANADA. MODEL SOUNDINGS FOR OUR NORTHEASTERN COUNTIES SHOW SOME
FAVORABLY FOR FREEZING DRIZZLE WITH A LOW LEVEL SATURATED LAYER
AND DRY AIR ALOFT. ON THE OTHER HAND...NOT MUCH RISING MOTION IN
SAID SATURATED LAYER AND LOOKING AT THE CLOUD LEVELS OBSERVED
UPSTREAM IN CANADA MOST ARE ABOVE 1000 FT. WOULD LIKE TO HAVE SOME
CLOSER DEW POINT DEPRESSIONS AND LOWER CEILINGS FOR DRIZZLE
FORMATION SO WILL KEEP MENTION OUT FOR NOW. WILL KEEP THE PATCHY
FOG MENTION IN THE NORTHWEST HOWEVER AS WINDS BEGIN TO GO LIGHT
AHEAD OF THE CLOUDS COMING IN AND THERE COULD BE SOME RADIATING
OUT A JUST SOME PATCHES OF FOG IN AREAS WHERE THERE WAS SNOW MELT
TODAY. ADJUSTED TEMPS UP A BIT AS MANY LOCATIONS HAVE BEEN STAYING
IN THE UPPER 20S TO 30S. THINK THERE WILL BE SOME FALLING BUT WITH
A FAIRLY WARM AIR MASS AND CLOUDS COMING IN LOWS WILL STAY IN THE
20S OVERNIGHT.
UPDATE ISSUED AT 644 PM CST FRI NOV 21 2014
WINDS WILL CONTINUE TO DIMINISH MAINLY IN THE NORTHWESTERN
COUNTIES WHERE THE TROUGH AXIS WILL ARRIVE LATER TONIGHT. WITH
LIGHT WINDS AND SOME DECENT RADIATING OUT...THINK SOME PATCHY FOG
IN SOME AREAS IS POSSIBLE. RAP HAS SOME LOW VIS IN THE NORTHWEST
SO KEPT A MENTION FOR THE DEVILS LAKE BASIN INTO THE NORTHERN RED
RIVER VALLEY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 323 PM CST FRI NOV 21 2014
SYSTEM TRACKING ACROSS SOUTHERN CANADA WILL CONTINUE EASTWARD
OVERNIGHT...RESULTING IN A WEAK COLD FRONT TO NEAR THE
INTERNATIONAL BORDER (MAIN RESULT WILL BE INCREASED CLOUD COVER).
THIS FEATURE WILL QUICKLY BE WASHED OUT AS THE NEXT SYSTEM
APPROACHES AND SOUTHERLY RETURN FLOW AGAIN DEVELOPS ON SATURDAY.
TEMPERATURES WILL BE THE MAIN CHALLENGE...WITH SATURDAY MAX TEMPS
SIMILAR OR EVEN SLIGHTLY WARMER (ESPECIALLY ACROSS THE SOUTHERN
FA) THAN TODAYS...BUT NOT SURE HOW MUCH WARMER.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 323 PM CST FRI NOV 21 2014
SATURDAY NIGHT-MONDAY...CONFIDENCE REMAINS LOW DURING THIS PERIOD
REGARDING HOW THE UPPER LOW WILL EVOLVE. MODELS ALL AGREE THAT THE
SOUTHERN SYSTEM WILL BE WELL EAST OF THE REGION...BUT COULD STILL
ACT TO SLOW DOWN THE NORTHERN WAVE THAT WILL AFFECT THIS REGION.
THE GFS IS SLIGHTLY QUICKER SATURDAY NIGHT AND INDICATES A BAND OF
PRECIP ASSOCIATED WITH 700MB CONVERGENCE/DEFORMATION. IF PRECIP
DOES OCCUR...IT COULD BE FREEZING RAIN/SLEET GIVEN THE WARM
TEMPERATURES ALOFT. DID INCLUDE A SCHC FOR MIXED PRECIP...BUT WITH
OTHER MODELS DRY (SLOWER) CANNOT GO WITH HIGHER POPS. THE UPPER
LOW THEN MOVES ACROSS THE REGION LATER SUNDAY INTO MONDAY. AS
THIS OCCURS...ANTICIPATE STRONG N/NW WINDS ALONG WITH SNOW
SHOWERS. AS OF NOW...WINDS ALONG AND WEST OF THE VALLEY SHOULD BE
30-40 MPH WITH HIGHER GUSTS (GIVEN EXPECTED COLD AIR
ADVECTION...SFC PRESSURE GRADIENT...AND WIND SPEEDS ALOFT). THESE
WINDS COMBINED WITH SNOW SHOWERS WOULD RESULT IN BRIEF PERIODS OF
SIGNIFICANTLY REDUCED VISIBILITY. ANY SNOW-PACK CURRENTLY ON THE
GROUND WILL NOT BE BLOW-ABLE WITH TEMPERATURES ABOVE FREEZING
DURING THE DAY TODAY...SATURDAY...AND POSSIBLY SUNDAY. SO...HOW
MUCH SNOW ACTUALLY FALLS WILL DETERMINE HOW WIDESPREAD THE BLOWING
SNOW IS DURING THIS PERIOD. STRONGEST FORCING WILL BE NORTH OF THE
INTERNATIONAL BORDER...AND GIVEN THE EXPECTED FORCING OVER THIS
REGION THINKING 1-2 INCHES AT MOST SOUTH OF THE INTERNATIONAL
BORDER (ALTHOUGH GFS INDICATES A STRONGER SYSTEM AND HIGHER QPF).
WILL CONTINUE TO MONITOR...BUT THE CURRENT MENTION IN THE HWO AND
WEATHER STORY SEEMS LIKE THE APPROPRIATE PRODUCTS AT THIS MOMENT
IN TIME.
MONDAY NIGHT-FRIDAY...500 MB TROUGH OVER THE GREAT LAKES REGION
MONDAY NIGHT INTO THURSDAY WITH FCST AREA ON THE COLD SIDE. CLOUDS
AND A CHANCE FOR SOME LIGHT SNOW WILL OCCUR TUESDAY INTO TUESDAY
NIGHT AHEAD OF A WEAK UPPER DISTURBANCE WHICH WILL MOVE THROUGH.
COLDEST AIRMASS AND HIGH PRESSURE SYSTEM TO ARRIVE WEDNESDAY-
THURSDAY. MODERATION OCCURS FRIDAY BUT LONG RANGE MODELS KEEP AREA
NEAR THE TIGHT BAROCLINIC ZONE BETWEEN COLD NORTH AND WARMER
SOUTHWEST. 12Z GFS/ECMWF SEEM IN GOOD AGREEMENT AND BLENDS WELL
WITH BLENDED MODEL DATA PROCEDURE. GOOD NEWS IS NO SIGNIFICANT
STORM SYSTEM FOR THE THANKSGIVING DAY TRAVEL PERIOD LOCALLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1153 PM CST FRI NOV 21 2014
STRATUS HAS STARTED TO CROSS THE CANADIAN BORDER BUT HAS STAYED
NORTH OF THE TAF SITES SO FAR. THE MODELS HAVE BEEN KEEPING THE
FRONTAL BOUNDARY AND LOWER CIGS FURTHER NORTH THAN PREVIOUS
RUNS...STAYING NORTH OF KGFK AND KBJI. THINK THAT THE MVFR STRATUS
MAY SEEP INTO KDVL AND KTVF FOR A WHILE THIS MORNING...BUT SHOULD
GO BACK TO VFR FOR A WHILE AS THE FRONT WASHES OUT SATURDAY
AFTERNOON. MORE MOISTURE COMING IN LATE IN THE PERIOD SHOULD BRING
CIGS BACK DOWN TO MVFR.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...TG
LONG TERM...TG/RIDDLE
AVIATION...JR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1046 PM EST SUN NOV 23 2014
.SYNOPSIS...
DEEPENING LOW PRESSURE WILL TRACK FROM THE LOWER MISSISSIPPI
VALLEY ACROSS THE GREAT LAKES ON MONDAY PUSHING A STRONG COLD
FRONT ACROSS THE AREA ON MONDAY WITH A SECOND COLD FRONT ON
TUESDAY. A WEAK LOW PRESSURE AREA AND A COLD FRONT WILL CROSS THE
LOWER GREAT LAKES LATER WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
WINDS WILL INCREASE OVERNIGHT AS LOW PRESSURE CONTINUES TO DEEPEN
AS IT TRACKS NORTH THROUGH THE CENTRAL GREAT LAKES. A WIND
ADVISORY REMAINS IN EFFECT FOR THE NORTHEAST LAKESHORE WITH THE
STRONGEST WINDS EXPECTED ACROSS NORTHERN ERIE PA COUNTY NEAR THE LAKESHORE.
THE HRRR SHOWS WINDS PEAKING BY ABOUT 2 AM IN THIS AREA THEN
DECREASING LATE TONIGHT AS THE WARM FRONT PASSES TO THE NORTH. EXPECT
THE STRONG WIND IN THE OTHER ADVISORY AREAS TO BE SOMEWHAT MORE
LOCALIZED WHERE DOWNSLOPING IS ENHANCED OFF THE HIGHER TERRIAN
AND SOME HELP FROM SHORELINE CONVERGENCE. WE HAVE ALREADY HAD A
WIND GUST TO 47 MPH AT LPR AND 41 MPH AT MFD. THESE FEW STRAY
GUSTS ABOVE 40 MPH ARE POSSIBLE OVERNIGHT BUT THINKING THEY WILL
STAY LIMITED ENOUGH TO NOT NEED TO EXPAND THE ADVISORY FOR THE
OVERNIGHT HOURS.
AS FOR THE HIGH WIND WATCH FOR MONDAY...A CORRIDOR OF THE
STRONGEST WINDS IS EXPECTED ACROSS NORTHWEST AND NORTH CENTRAL
OHIO BEHIND THE FRONT WHERE GUSTS OF 50-60 MPH ARE POSSIBLE.
ELSEWHERE IT LOOKS LIKE THE PEAK GUSTS MAY ONLY OCCUR WITH SHOWERS
SO COULD POSSIBLY BE HANDLED WITH A WIND ADVISORY AND SHORT FUSED CONVECTIVE
PRODUCTS IF NECESSARY. ALWAYS TOUGH THIS TIME OF YEAR TO DECIDE
BETWEEN SVR WARNINGS AND HIGH WIND WARNINGS. FEW CHANGES MADE WITH
THE UPDATE.
PREVIOUS DISCUSSION...RAIN SHOULD SPREAD ACROSS THE AREA TONIGHT
AS THE MAIN SHORT WAVE LIFTS OUT. THE SOUTH SOUTHEAST DOWN SLOPE
WIND LESSEN THE RAIN TO SOME EXTENT ACROSS NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA BUT EVERYONE SHOULD SEE A PERIOD OF
RAIN/SHOWERS.
THE LOW LEVEL JET IS PROGGED TO INCREASE DRAMATICALLY TONIGHT...
INCREASING TO 70-80 KNOTS. DOES NOT GET MUCH STRONGER THAN THAT. THE
WARM AIR ALOFT AND THE RAIN SHOULD DO A GOOD JOB AT KEEPING THE
LOWER LAYERS STABLE. THE MIXED LAYER IS PROGGED TO REMAIN RELATIVELY
SHALLOW TONIGHT...ONLY ABOUT 1K. WE CAN PROBABLY KEEP THE SOUTH
DOWN SLOPE WINDS IN CHECK. THAT BEING SAID...WE CAN STILL TAP
30-35 KNOT WINDS EVEN WITH THE STABLE CONDITIONS. CANNOT RULE OUT
THAT ROGUE 40 KNOT GUST SOMEWHERE BUT IN GENERAL WE SHOULD BE ABLE
TO STAY UNDER THE WIND ADVISORY/WARNING CRITERIA TONIGHT. THE
EXCEPTION WOULD BE ALONG THE EAST LAKESHORE FROM EAST OF MENTOR
THROUGH ERIE COUNTY PA. WILL NEED TO HAVE AN ADVISORY THERE
STARTING ABOUT 10 PM. JUST A LITTLE TOO EASY WITH THE DOWN SLOPE
COMPLIMENT TO GET TO 40 KNOTS OR MORE ESPECIALLY IN ERIE COUNTY PA.
TEMPS MAY DROP A FEW DEGREES WITH THE ONSET OF THE RAIN OTHERWISE
WITH THE STRONG SOUTH FLOW AND RISING DEWPOINTS...TEMPERATURES
WILL BE STEADY OR RISE TONIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
WIND WILL BE THE CONCERN ON MONDAY. WE START THE DAY WITH A 30-40
KNOTS AT 925 MB AND 60 KNOTS OR MORE AT 850 MB. AS STATED
ABOVE...THE RAIN WILL CREATE A RELATIVELY STABLE SITUATION IN THE
BOUNDARY LAYER EARLY ON...BUT THAT WILL ERODE ESPECIALLY WITH THE
ARRIVAL OF THE COLD FRONT. WE TYPICALLY CAN GET 60-70% MIXING IN
THIS TYPE OF SITUATION. THAT WOULD NECESSITATE A WIND ADVISORY...
WITH STRONG ISENTROPIC DESCENT AND LARGE PRESSURE RISES ARRIVING
(+6 TO +8 MB)...A SOUTHWEST WIND DIRECTION IN LINE WITH THE
MOMENTUM AND MOVEMENT OF THE SURFACE LOW....LITTLE LOW LEVEL SHEAR
AND THE POSSIBILITY OF A CONVECTIVE LINE OF SHOWERS WITH THE
FRONTAL PASSAGE...NOT TOO MENTION A FAVORABLE TIME OF DAY FOR
MAXIMUM MIXING...A WIND WARNING MAY BE NECESSARY. I WOULD FEEL
MORE CERTAIN IF THE COLD ADVECTION WAS STRONGER AND QUICKER. WILL
ISSUE A HIGH WIND WATCH AND KEEP THE OPTIONS OPEN FOR EITHER A
WIND ADVISORY OR A HIGH WIND WARNING FOR MONDAY AFTERNOON WITH THE
PASSAGE OF THE COLD FRONT...CONTINUING INTO THE EVENING.
WARM UNTIL THE FRONTAL PASSAGE ON MONDAY. HIGHS GENERALLY 55 TO
60 AHEAD OF THE FRONT.
SEASONABLY COLDER AIR WILL SWEEP IN BEHIND THE FRONT. TEMPERATURES
WILL LIKELY NOT DROP OFF TOO QUICKLY ON MONDAY AFTERNOON GIVEN
THE WELL MIXED NATURE OF THE AIR MASS AND THE CHANCE THAT A FEW
PEAKS OF SUNSHINE MIGHT DEVELOP. LOWS MONDAY NIGHT NEAR NORMAL IN
THE UPPER 20S/LOWER 30S.
THE FLOW WILL BE SOUTHWEST ON TUESDAY. NOT MUCH LAKE INFLUENCE
EXCEPT PERHAPS FROM ASHTABULA TO ERIE WHERE SOME SNOW
SHOWERS/FLURRIES MIGHT CLIP THE LAKESHORE. THE STRATOCUMULUS WILL
INCREASE DIURNALLY DURING THE DAY...PARTLY TO MOSTLY CLOUDY. HIGHS
IN THE 30S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MODELS CONTINUE WITH A COASTAL LOW OFF THE MID ATLANTIC COAST
WEDNESDAY EVENING...THEN DEEPENING AND TRACKING INTO NEWFOUNDLAND
THANKSGIVING DAY. TROUGH WILL REMAIN OVER THE EASTERN LAKES THROUGH
THURSDAY NIGHT. BEST MOISTURE IN THE WEST SO KEPT LIKELY POPS
ACROSS THE EASTERN CWA. COLDER AIR BEHIND THE CLIPPER DROPS THE
850MB TEMPS OVER LAKE ERIE TO -14C BY THURSDAY EVENING SO LAKE
EFFECT SNOW LIKELY...PRIMARILY IN THE SNOWBELT THURSDAY NIGHT. HIGH
PRESSURE MOVES OVER THE AREA FRIDAY CHOCKING OF LINGERING LAKE
EFFECT.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
A WARM FRONT OVER THE OHIO VALLEY WILL MOVE NORTH OVERNIGHT
SPREADING SHOWERS INTO THE AREA. A BREAK WILL OCCUR IN THE WARM
SECTOR ON MONDAY AND THEN A STRONG COLD FRONT WILL MOVE THROUGH.
SOME SHOWERS AND MAY BE EVEN AN ISOLATED THUNDERSTORM MAY OCCUR.
GUSTY SOUTHEAST TO SOUTH WINDS WILL OCCUR AT TIMES TONIGHT AS THE
LOW MOVES FROM THE MIDWEST TO THE UPPER PENINSULA OF MICHIGAN.
SOME LOW LEVEL WIND SHEAR MAY OCCUR THROUGH 06Z. OTHERWISE IT WILL
JUST BE MECHANICAL TURBULENCE.
ON MONDAY AS THE BAND OF SHOWERS MOVES THROUGH STRONG WINDS WILL
BE ASSOCIATED WITH THE FRONT AND BEHIND IT IN THE COLD ADVECTION.
.OUTLOOK...NON VFR TUESDAY AND THEN AGAIN WEDNESDAY NIGHT INTO
THURSDAY IN -SN.
&&
.MARINE...
ISSUED GALE WARNING FOR LAKE ERIE BEGINNING MONDAY MORNING.
MODELS CONTINUE TO DEEPEN THE OKLAHOMA LOW NORTH OVER LAKE
MICHIGAN TONIGHT LIFTING A WARM FRONT ACROSS THE LAKE. BY DAYBREAK
THE THE 925MB WINDS INCREASE TO 40-45 KNOTS...NOT SURE HOW MUCH
WILL MIX DOWN IN WAA PATTERN. STRONGEST WINDS EXPECTED IMMEDIATELY
AHEAD AND BEHIND THE ARCTIC FRONT. MODELS MOVE THE FRONT ACROSS
LAKE ERIE DURING MONDAY AFTERNOON. EXPECT 40 KNOT GALES...BUT 45
KNOT GALES NOT OUT OF THE QUESTION. THIS STRONG SOUTHWEST FLOW
WILL CREATE A LOW WATER SITUATION FOR THE WESTERN BASIN. WINDS ARE
EXPECTED TO REMAIN AT GALE FORCE INTO TUESDAY MORNING...THEN
SLOWLY DIMINISH TUESDAY NIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL NOON EST MONDAY FOR OHZ012-089.
HIGH WIND WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR OHZ011>014-020>023-031>033-038-089.
HIGH WIND WATCH FROM 10 AM EST MONDAY THROUGH MONDAY EVENING
FOR OHZ003-006>010-017>019-027>030-036-037-047.
PA...WIND ADVISORY UNTIL NOON EST MONDAY FOR PAZ001-002.
HIGH WIND WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR PAZ001>003.
MARINE...GALE WARNING FROM 9 AM MONDAY TO 4 PM EST TUESDAY FOR LEZ061-
145>149-165>169.
LOW WATER ADVISORY FROM 3 PM MONDAY TO 4 PM EST TUESDAY FOR
LEZ142>144-162>164.
GALE WARNING FROM 9 AM MONDAY TO 10 AM EST TUESDAY FOR
LEZ142>144-162>164.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KEC/KOSARIK
SHORT TERM...KOSARIK
LONG TERM...DJB
AVIATION...KIELTYKA
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1201 PM EST SAT NOV 22 2014
.SYNOPSIS...
FLOW BECOMES SOUTHWESTERLY TODAY...INCREASING SUNDAY FOR A WARMER
BUT WET WEEKEND. LOW PRESSURE BRINGS A WARM FRONT SUNDAY NIGHT...
FOLLOWED BY A COLD FRONT MONDAY WITH GOOD CHANCES FOR RAIN SHOWERS.
&&
.NEAR TERM /THROUGH SUNDAY/...
11AM UPDATE...ALLOWED FREEZING RAIN ADVISORY TO EXPIRE AS TEMPS
ARE QUICKLY CLIMBING ABOVE FREEZING.
PREVIOUS DISCUSSION...
LATEST RADAR TRENDS HAVE A SLUG OF MOISTURE MOVING TOWARDS WV AND
TEMPS ARE STILL IN THE MID TEENS. HRRR HAS THE SLUG DRYING OUT
EXCEPT FOR PORTIONS OF SE OHIO...SO WENT WITH A FREEZING RAIN
ADVISORY FOR A BRIEF PERIOD WHERE PRECIP WILL BE FALLING INTO A
COLD AIR MASS. OBSERVATION IN PERRY COUNTY AT 27 SO OPTED TO LEAVE
THEM OUT AS THE WARM AIR EXTENDS TO ABOUT PERRY CNTY. AFTER 9 AM
TEMPS SHOULD WARM ABOVE FREEZING AND THE FZRA THREAT WILL BE
GONE.
THEN A PLEASANT DRY...DAY WHERE TEMPERATURES REBOUND TO NORMAL.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
SHOWERS WILL CONTINUE THROUGH TO MONDAY MORNING WITH A WARM FRONT
LIFTING NORTH OVERNIGHT SUNDAY. THE WARM TEMPERATURES WILL BE SHORT
LIVED AS THE ASSOCIATED COLD FRONT MOVES EAST THROUGH THE FORECAST
AREA EARLY MONDAY. THE COLD FRONT WILL BRING ONLY A SLIGHT CHANCE
OF SHOWERS BEFORE EXITING MONDAY NIGHT. BEHIND THE FRONT...EXPECT
MOSTLY DRY BUT MUCH COOLER WEATHER.
WINDS ON MONDAY AND INTO TUESDAY WILL BE STRONG...PARTICULARLY ALONG
THE OHIO RIVER VALLEY AND AT HIGHER ELEVATIONS...WITH THE GFS
SHOWING 925MB WINDS OF UP TO 60 KTS OVER THE OHIO
VALLEY...HOWEVER...NOT CURRENTLY EXPECTING TO REACH ADVISORY
CRITERIA. WINDS SHOULD DIMINISH THROUGH THE PERIOD AS THE STRONGER
WINDS LIFT NORTH.
THE CONSRAW APPEARS TO HAVE A GOOD HANDLE ON THE NONDIURNAL
TEMPERATURES FOR MONDAY SO USED IT WITH JUST A FEW TWEAKS. LOWS
MONDAY MORNING WILL ONLY DIP INTO THE MID 50S BEFORE REACHING THE
HIGH BY AROUND 16Z.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
SHOWERS WILL BEGIN TO END ON MONDAY NIGHT AS THE TROUGH WEAKENS AND
MOVES EAST. MODEL TRENDS HAVE WAFFLED A BIT WITH NEITHER THE GFS
AND ECMWF STAYING WITH A GREAT SOLUTION. SHORTWAVES ARE MORE
EVIDENT IN DEEPER TROUGH EXHIBITED BY THE ECMWF...BUT THE GFS
CURRENTLY SHOWS A MORE WESTERN FLOW. TOOK A BLEND OF THE TWO MODELS
TO RESOLVE SOME OF THE DISAGREEMENT IN THE HOPES THE SOLUTIONS WILL
CONVERGE AS WE MOVE CLOSER IN TIME.
TEMPERATURES WILL COOL SIGNIFICANTLY BY TUESDAY WITH THE PASSAGE OF
A COLD FRONT. THESE COOLER TEMPERATURES COMBINED WITH LOW PRESSURE
MOVING EAST FROM THE GREAT LAKES WILL PROVIDE SOME OPPORTUNITY FOR
SOME SNOW SHOWERS ALONG THE OHIO RIVER EARLY
THURSDAY...TRANSITIONING TO RAIN BY AFTERNOON FOR THE LOWLANDS. THE
MOUNTAINS WILL CONTINUE TO HAVE A SLIGHT CHANCE OF SOME SNOW SHOWERS
THROUGH THE NIGHT.
&&
.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
QUIET VFR WEATHER. A BRIEF PERIOD OF FREEZING RAIN IS POSSIBLE IN
INTERIOR SE OHIO SAT MORNING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: LOW CHANCE OF MVFR CIGS ACROSS INTERIOR SE OHIO
SAT MORNING AND THE NRN WV MOUNTAINS SAT MIDDAY AND AFTERNOON.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SUNDAY...
IFR POSSIBLE ON EASTERN MOUNTAIN SLOPES AND ACROSS THE MIDDLE OHIO
VALLEY IN RAIN AND STRATUS LATE SUN INTO MON MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/MZ
NEAR TERM...MZ
SHORT TERM...ARJ
LONG TERM...LS
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1103 AM EST SAT NOV 22 2014
.SYNOPSIS...
FLOW BECOMES SOUTHWESTERLY TODAY...INCREASING SUNDAY FOR A WARMER
BUT WET WEEKEND. LOW PRESSURE BRINGS A WARM FRONT SUNDAY NIGHT...
FOLLOWED BY A COLD FRONT MONDAY WITH GOOD CHANCES FOR RAIN SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
11AM UPDATE...ALLOWED FREEZING RAIN ADVISORY TO EXPIRE AS TEMPS
ARE QUICKLY CLIMBING ABOVE FREEZING.
PREVIOUS DISCUSSION...
LATEST RADAR TRENDS HAVE A SLUG OF MOISTURE MOVING TOWARDS WV AND
TEMPS ARE STILL IN THE MID TEENS. HRRR HAS THE SLUG DRYING OUT
EXCEPT FOR PORTIONS OF SE OHIO...SO WENT WITH A FREEZING RAIN
ADVISORY FOR A BRIEF PERIOD WHERE PRECIP WILL BE FALLING INTO A
COLD AIR MASS. OBSERVATION IN PERRY COUNTY AT 27 SO OPTED TO LEAVE
THEM OUT AS THE WARM AIR EXTENDS TO ABOUT PERRY CNTY. AFTER 9 AM
TEMPS SHOULD WARM ABOVE FREEZING AND THE FZRA THREAT WILL BE
GONE.
THEN A PLEASANT DRY...DAY WHERE TEMPERATURES REBOUND TO NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AN APPROACHING LOW PRESSURE SYSTEM WILL LIFT FROM THE MISSISSIPPI
VALLEY...NORTH NORTHEAST INTO THE OH VALLEY AND WV SUNDAY AND
MONDAY. MODELS INDICATE WIND FLOW WILL TURN DEEP FROM THE SOUTH
SOUTHWEST...TO BRING MOIST AND WARM AIR MASS ON SUNDAY. A WARM
FRONT WILL MERGE FROM THIS FLOW TO PRODUCE AREAS OF RAIN SPREADING
FROM SOUTH TO NORTH.
WIND FLOW WILL INCREASE BY 00Z MONDAY...AS SUGGESTED BY H850 WINDS
FROM THE GFS/ECMWF OF ABOUT 65-70 KNOTS. UNDER ISENTROPIC
UP GLIDING...IT WILL BE MORE LIKELY FOR SOME OF THESE WINDS TO
CREATE GUSTY CONDITIONS OVER HIGHER ELEVATIONS.
AN ASSOCIATED COLD FRONT WILL CROSS WEST TO EAST EARLY MONDAY. WITH H850
TEMPERATURES AROUND 10C...EXPECT ALL PCPN TO FALL AS LIQUID.
THEREFORE...EXPECT ROUNDS OF SCATTERED TO NUMEROUS RAIN SHOWERS.
PW AROUND 1.25 INCHES AND STRONG DEEP LAYERED SHEAR COULD PRODUCE
A LOW CHANCE FOR THUNDER...BUT WILL KEEP MENTION OUT OF FORECAST.
COLDER AIR RUSHES IN BEHIND THE COLD FRONT DROPPING TO MINUS 6C BY
06 TUESDAY.
WENT CLOSE TO PREVIOUS TEMPERATURES...PERHAPS A LITTLE WARMER
SUNDAY INTO MONDAY DUE TO STRONG DEEP SOUTH SOUTHWESTERLY FLOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
SHOWERS WILL BEGIN TO END ON MONDAY NIGHT AS THE TROUGH WEAKENS AND
MOVES EAST. MODEL TRENDS HAVE WAFFLED A BIT WITH NEITHER THE GFS
AND ECMWF STAYING WITH A GREAT SOLUTION. SHORTWAVES ARE MORE
EVIDENT IN DEEPER TROUGH EXHIBITED BY THE ECMWF...BUT THE GFS
CURRENTLY SHOWS A MORE WESTERN FLOW. TOOK A BLEND OF THE TWO MODELS
TO RESOLVE SOME OF THE DISAGREEMENT IN THE HOPES THE SOLUTIONS WILL
CONVERGE AS WE MOVE CLOSER IN TIME.
TEMPERATURES WILL COOL SIGNIFICANTLY BY TUESDAY WITH THE PASSAGE OF
A COLD FRONT. THESE COOLER TEMPERATURES COMBINED WITH LOW PRESSURE
MOVING EAST FROM THE GREAT LAKES WILL PROVIDE SOME OPPORTUNITY FOR
SOME SNOW SHOWERS ALONG THE OHIO RIVER EARLY
THURSDAY...TRANSITIONING TO RAIN BY AFTERNOON FOR THE LOWLANDS. THE
MOUNTAINS WILL CONTINUE TO HAVE A SLIGHT CHANCE OF SOME SNOW SHOWERS
THROUGH THE NIGHT.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
QUIET VFR WEATHER. A BRIEF PERIOD OF FREEZING RAIN IS POSSIBLE IN
INTERIOR SE OHIO SAT MORNING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: LOW CHANCE OF MVFR CIGS ACROSS INTERIOR SE OHIO
SAT MORNING AND THE NRN WV MOUNTAINS SAT MIDDAY AND AFTERNOON.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SUNDAY...
IFR POSSIBLE ON EASTERN MOUNTAIN SLOPES AND ACROSS THE MIDDLE OHIO
VALLEY IN RAIN AND STRATUS LATE SUN INTO MON MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/JW
NEAR TERM...MZ/JW
SHORT TERM...ARJ
LONG TERM...LS
AVIATION...JW
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
828 AM EST SAT NOV 22 2014
.SYNOPSIS...
FLOW BECOMES SOUTHWESTERLY TODAY...INCREASING SUNDAY FOR A WARMER
BUT WET WEEKEND. LOW PRESSURE BRINGS A WARM FRONT SUNDAY NIGHT...
FOLLOWED BY A COLD FRONT MONDAY WITH GOOD CHANCES FOR RAIN SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
820 AM UPDATE...WARM ADVECTION A BIT SLOWER TO PICK UP THAN
PREVIOUSLY THOUGHT...SO LOWERED TEMPS FOR THE NEXT COUPLE HOURS.
THIS ALSO PROMPTED AN EXTENSION OF THE FREEZING RAIN ADVISORY
UNTIL 11 AM. HAVE RECEIVED A COUPLE CALLS FROM MORGAN COUNTY OHIO OF
FREEZING RAIN WITH ICE ON ROADS.
PREVIOUS DISCUSSION...
LATEST RADAR TRENDS HAVE A SLUG OF MOISTURE MOVING TOWARDS WV AND
TEMPS ARE STILL IN THE MID TEENS. HRRR HAS THE SLUG DRYING OUT
EXCEPT FOR PORTIONS OF SE OHIO...SO WENT WITH A FREEZING RAIN
ADVISORY FOR A BRIEF PERIOD WHERE PRECIP WILL BE FALLING INTO A
COLD AIR MASS. OBSERVATION IN PERRY COUNTY AT 27 SO OPTED TO LEAVE
THEM OUT AS THE WARM AIR EXTENDS TO ABOUT PERRY CNTY. AFTER 9 AM
TEMPS SHOULD WARM ABOVE FREEZING AND THE FZRA THREAT WILL BE
GONE.
THEN A PLEASANT DRY...DAY WHERE TEMPERATURES REBOUND TO NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AN APPROACHING LOW PRESSURE SYSTEM WILL LIFT FROM THE MISSISSIPPI
VALLEY...NORTH NORTHEAST INTO THE OH VALLEY AND WV SUNDAY AND
MONDAY. MODELS INDICATE WIND FLOW WILL TURN DEEP FROM THE SOUTH
SOUTHWEST...TO BRING MOIST AND WARM AIR MASS ON SUNDAY. A WARM
FRONT WILL MERGE FROM THIS FLOW TO PRODUCE AREAS OF RAIN SPREADING
FROM SOUTH TO NORTH.
WIND FLOW WILL INCREASE BY 00Z MONDAY...AS SUGGESTED BY H850 WINDS
FROM THE GFS/ECMWF OF ABOUT 65-70 KNOTS. UNDER ISENTROPIC
UP GLIDING...IT WILL BE MORE LIKELY FOR SOME OF THESE WINDS TO
CREATE GUSTY CONDITIONS OVER HIGHER ELEVATIONS.
AN ASSOCIATED COLD FRONT WILL CROSS WEST TO EAST EARLY MONDAY. WITH H850
TEMPERATURES AROUND 10C...EXPECT ALL PCPN TO FALL AS LIQUID.
THEREFORE...EXPECT ROUNDS OF SCATTERED TO NUMEROUS RAIN SHOWERS.
PW AROUND 1.25 INCHES AND STRONG DEEP LAYERED SHEAR COULD PRODUCE
A LOW CHANCE FOR THUNDER...BUT WILL KEEP MENTION OUT OF FORECAST.
COLDER AIR RUSHES IN BEHIND THE COLD FRONT DROPPING TO MINUS 6C BY
06 TUESDAY.
WENT CLOSE TO PREVIOUS TEMPERATURES...PERHAPS A LITTLE WARMER
SUNDAY INTO MONDAY DUE TO STRONG DEEP SOUTH SOUTHWESTERLY FLOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
SHOWERS WILL BEGIN TO END ON MONDAY NIGHT AS THE TROUGH WEAKENS AND
MOVES EAST. MODEL TRENDS HAVE WAFFLED A BIT WITH NEITHER THE GFS
AND ECMWF STAYING WITH A GREAT SOLUTION. SHORTWAVES ARE MORE
EVIDENT IN DEEPER TROUGH EXHIBITED BY THE ECMWF...BUT THE GFS
CURRENTLY SHOWS A MORE WESTERN FLOW. TOOK A BLEND OF THE TWO MODELS
TO RESOLVE SOME OF THE DISAGREEMENT IN THE HOPES THE SOLUTIONS WILL
CONVERGE AS WE MOVE CLOSER IN TIME.
TEMPERATURES WILL COOL SIGNIFICANTLY BY TUESDAY WITH THE PASSAGE OF
A COLD FRONT. THESE COOLER TEMPERATURES COMBINED WITH LOW PRESSURE
MOVING EAST FROM THE GREAT LAKES WILL PROVIDE SOME OPPORTUNITY FOR
SOME SNOW SHOWERS ALONG THE OHIO RIVER EARLY
THURSDAY...TRANSITIONING TO RAIN BY AFTERNOON FOR THE LOWLANDS. THE
MOUNTAINS WILL CONTINUE TO HAVE A SLIGHT CHANCE OF SOME SNOW SHOWERS
THROUGH THE NIGHT.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
QUIET VFR WEATHER. A BRIEF PERIOD OF FREEZING RAIN IS POSSIBLE IN
INTERIOR SE OHIO SAT MORNING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: LOW CHANCE OF MVFR CIGS ACROSS INTERIOR SE OHIO
SAT MORNING AND THE NRN WV MOUNTAINS SAT MIDDAY AND AFTERNOON.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z SUNDAY...
IFR POSSIBLE ON EASTERN MOUNTAIN SLOPES AND ACROSS THE MIDDLE OHIO
VALLEY IN RAIN AND STRATUS LATE SUN INTO MON MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR WVZ009.
OH...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR OHZ066-
067-075-076-083>086.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/JW
NEAR TERM...MZ/JW
SHORT TERM...ARJ
LONG TERM...LS
AVIATION...JW
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
648 AM EST SAT NOV 22 2014
.SYNOPSIS...
FLOW BECOMES SOUTHWESTERLY TODAY...INCREASING SUNDAY FOR A WARMER
BUT WET WEEKEND. LOW PRESSURE BRINGS A WARM FRONT SUNDAY NIGHT...
FOLLOWED BY A COLD FRONT MONDAY WITH GOOD CHANCES FOR RAIN SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
ADDED PERRY COUNTY UNDER FREEZING RAIN ADVISORY UNTIL 9 AM.
LATEST RADAR TRENDS HAVE A SLUG OF MOISTURE MOVING TOWARDS WV AND
TEMPS ARE STILL IN THE MID TEENS. HRRR HAS THE SLUG DRYING OUT
EXCEPT FOR PORTIONS OF SE OHIO...SO WENT WITH A FREEZING RAIN
ADVISORY FOR A BRIEF PERIOD WHERE PRECIP WILL BE FALLING INTO A
COLD AIR MASS. OBSERVATION IN PERRY COUNTY AT 27 SO OPTED TO LEAVE
THEM OUT AS THE WARM AIR EXTENDS TO ABOUT PERRY CNTY. AFTER 9 AM
TEMPS SHOULD WARM ABOVE FREEZING AND THE FZRA THREAT WILL BE
GONE.
THEN A PLEASANT DRY...DAY WHERE TEMPERATURES REBOUND TO NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AN APPROACHING LOW PRESSURE SYSTEM WILL LIFT FROM THE MISSISSIPPI
VALLEY...NORTH NORTHEAST INTO THE OH VALLEY AND WV SUNDAY AND
MONDAY. MODELS INDICATE WIND FLOW WILL TURN DEEP FROM THE SOUTH
SOUTHWEST...TO BRING MOIST AND WARM AIR MASS ON SUNDAY. A WARM
FRONT WILL MERGE FROM THIS FLOW TO PRODUCE AREAS OF RAIN SPREADING
FROM SOUTH TO NORTH.
WIND FLOW WILL INCREASE BY 00Z MONDAY...AS SUGGESTED BY H850 WINDS
FROM THE GFS/ECMWF OF ABOUT 65-70 KNOTS. UNDER ISENTROPIC
UP GLIDING...IT WILL BE MORE LIKELY FOR SOME OF THESE WINDS TO
CREATE GUSTY CONDITIONS OVER HIGHER ELEVATIONS.
AN ASSOCIATED COLD FRONT WILL CROSS WEST TO EAST EARLY MONDAY. WITH H850
TEMPERATURES AROUND 10C...EXPECT ALL PCPN TO FALL AS LIQUID.
THEREFORE...EXPECT ROUNDS OF SCATTERED TO NUMEROUS RAIN SHOWERS.
PW AROUND 1.25 INCHES AND STRONG DEEP LAYERED SHEAR COULD PRODUCE
A LOW CHANCE FOR THUNDER...BUT WILL KEEP MENTION OUT OF FORECAST.
COLDER AIR RUSHES IN BEHIND THE COLD FRONT DROPPING TO MINUS 6C BY
06 TUESDAY.
WENT CLOSE TO PREVIOUS TEMPERATURES...PERHAPS A LITTLE WARMER
SUNDAY INTO MONDAY DUE TO STRONG DEEP SOUTH SOUTHWESTERLY FLOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
SHOWERS WILL BEGIN TO END ON MONDAY NIGHT AS THE TROUGH WEAKENS AND
MOVES EAST. MODEL TRENDS HAVE WAFFLED A BIT WITH NEITHER THE GFS
AND ECMWF STAYING WITH A GREAT SOLUTION. SHORTWAVES ARE MORE
EVIDENT IN DEEPER TROUGH EXHIBITED BY THE ECMWF...BUT THE GFS
CURRENTLY SHOWS A MORE WESTERN FLOW. TOOK A BLEND OF THE TWO MODELS
TO RESOLVE SOME OF THE DISAGREEMENT IN THE HOPES THE SOLUTIONS WILL
CONVERGE AS WE MOVE CLOSER IN TIME.
TEMPERATURES WILL COOL SIGNIFICANTLY BY TUESDAY WITH THE PASSAGE OF
A COLD FRONT. THESE COOLER TEMPERATURES COMBINED WITH LOW PRESSURE
MOVING EAST FROM THE GREAT LAKES WILL PROVIDE SOME OPPORTUNITY FOR
SOME SNOW SHOWERS ALONG THE OHIO RIVER EARLY
THURSDAY...TRANSITIONING TO RAIN BY AFTERNOON FOR THE LOWLANDS. THE
MOUNTAINS WILL CONTINUE TO HAVE A SLIGHT CHANCE OF SOME SNOW SHOWERS
THROUGH THE NIGHT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
QUIET VFR WEATHER. A BRIEF PERIOD OF FREEZING RAIN IS POSSIBLE IN
INTERIOR SE OHIO SAT MORNING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: LOW CHANCE OF MVFR CIGS ACROSS INTERIOR SE OHIO
SAT MORNING AND THE NRN WV MOUNTAINS SAT MIDDAY AND AFTERNOON.
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
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z SUNDAY...
IFR POSSIBLE ON EASTERN MOUNTAIN SLOPES AND ACROSS THE MIDDLE OHIO
VALLEY IN RAIN AND STRATUS LATE SUN INTO MON MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR WVZ009.
OH...FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR OHZ066-
067-075-076-083>086.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/JW
NEAR TERM...JW
SHORT TERM...ARJ
LONG TERM...LS
AVIATION...JW
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
458 AM EST SAT NOV 22 2014
.SYNOPSIS...
FLOW BECOMES SOUTHWESTERLY TODAY...INCREASING SUNDAY FOR A WARMER
BUT WET WEEKEND. LOW PRESSURE BRINGS A WARM FRONT SUNDAY NIGHT...
FOLLOWED BY A COLD FRONT MONDAY WITH GOOD CHANCES FOR RAIN SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST RADAR TRENDS HAVE A SLUG OF MOISTURE MOVING TOWARDS WV AND
TEMPS ARE STILL IN THE MID TEENS. HRRR HAS THE SLUG DRYING OUT
EXCEPT FOR PORTIONS OF SE OHIO...SO WENT WITH A FREEZING RAIN
ADVISORY FOR A BRIEF PERIOD WHERE PRECIP WILL BE FALLING INTO A
COLD AIR MASS. OBSERVATION IN PERRY COUNTY AT 27 SO OPTED TO LEAVE
THEM OUT AS THE WARM AIR EXTENDS TO ABOUT PERRY CNTY. AFTER 9 AM
TEMPS SHOULD WARM ABOVE FREEZING AND THE FZRA THREAT WILL BE
GONE.
THEN A PLEASANT DRY...DAY WHERE TEMPERATURES REBOUND TO NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AN APPROACHING LOW PRESSURE SYSTEM WILL LIFT FROM THE MISSISSIPPI
VALLEY...NORTH NORTHEAST INTO THE OH VALLEY AND WV SUNDAY AND
MONDAY. MODELS INDICATE WIND FLOW WILL TURN DEEP FROM THE SOUTH
SOUTHWEST...TO BRING MOIST AND WARM AIR MASS ON SUNDAY. A WARM
FRONT WILL MERGE FROM THIS FLOW TO PRODUCE AREAS OF RAIN SPREADING
FROM SOUTH TO NORTH.
WIND FLOW WILL INCREASE BY 00Z MONDAY...AS SUGGESTED BY H850 WINDS
FROM THE GFS/ECMWF OF ABOUT 65-70 KNOTS. UNDER ISENTROPIC
UP GLIDING...IT WILL BE MORE LIKELY FOR SOME OF THESE WINDS TO
CREATE GUSTY CONDITIONS OVER HIGHER ELEVATIONS.
AN ASSOCIATED COLD FRONT WILL CROSS WEST TO EAST EARLY MONDAY. WITH H850
TEMPERATURES AROUND 10C...EXPECT ALL PCPN TO FALL AS LIQUID.
THEREFORE...EXPECT ROUNDS OF SCATTERED TO NUMEROUS RAIN SHOWERS.
PW AROUND 1.25 INCHES AND STRONG DEEP LAYERED SHEAR COULD PRODUCE
A LOW CHANCE FOR THUNDER...BUT WILL KEEP MENTION OUT OF FORECAST.
COLDER AIR RUSHES IN BEHIND THE COLD FRONT DROPPING TO MINUS 6C BY
06 TUESDAY.
WENT CLOSE TO PREVIOUS TEMPERATURES...PERHAPS A LITTLE WARMER
SUNDAY INTO MONDAY DUE TO STRONG DEEP SOUTH SOUTHWESTERLY FLOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
SHOWERS WILL BEGIN TO END ON MONDAY NIGHT AS THE TROUGH WEAKENS AND
MOVES EAST. MODEL TRENDS HAVE WAFFLED A BIT WITH NEITHER THE GFS
AND ECMWF STAYING WITH A GREAT SOLUTION. SHORTWAVES ARE MORE
EVIDENT IN DEEPER TROUGH EXHIBITED BY THE ECMWF...BUT THE GFS
CURRENTLY SHOWS A MORE WESTERN FLOW. TOOK A BLEND OF THE TWO MODELS
TO RESOLVE SOME OF THE DISAGREEMENT IN THE HOPES THE SOLUTIONS WILL
CONVERGE AS WE MOVE CLOSER IN TIME.
TEMPERATURES WILL COOL SIGNIFICANTLY BY TUESDAY WITH THE PASSAGE OF
A COLD FRONT. THESE COOLER TEMPERATURES COMBINED WITH LOW PRESSURE
MOVING EAST FROM THE GREAT LAKES WILL PROVIDE SOME OPPORTUNITY FOR
SOME SNOW SHOWERS ALONG THE OHIO RIVER EARLY
THURSDAY...TRANSITIONING TO RAIN BY AFTERNOON FOR THE LOWLANDS. THE
MOUNTAINS WILL CONTINUE TO HAVE A SLIGHT CHANCE OF SOME SNOW SHOWERS
THROUGH THE NIGHT.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
QUIET VFR WEATHER. A BRIEF PERIOD OF FREEZING RAIN IS POSSIBLE IN
INTERIOR SE OHIO SAT MORNING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: LOW CHANCE OF MVFR CIGS ACROSS INTERIOR SE OHIO
SAT MORNING AND THE NRN WV MOUNTAINS SAT MIDDAY AND AFTERNOON.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 11/22/14
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z SUNDAY...
IFR POSSIBLE ON EASTERN MOUNTAIN SLOPES AND ACROSS THE MIDDLE OHIO
VALLEY IN RAIN AND STRATUS LATE SUN INTO MON MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR WVZ009.
OH...FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR OHZ067-
075-076-083>086.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/JW
NEAR TERM...JW
SHORT TERM...ARJ
LONG TERM...LS
AVIATION...JW
AREA FORECAST DISCUSSION
NWS TULSA OK
312 PM CST SAT NOV 22 2014
.DISCUSSION...
ROUND 2 OF THE PRECIP IS ONGOING OVER THE REGION TODAY...WITHIN
THE WARM CONVEYOR OF THE UPPER CYCLONE CENTERED OVER THE RIO
GRANDE VALLEY ATTM. THE LATEST HRRR MAINTAINS THIS BAND OF RAIN
FROM SE/E CNTRL OK UP INTO NW AR THIS EVENING SO POPS HAVE BEEN
ADJUSTED FOR THE 00Z TO 06Z TIME FRAME. THERE SHOULD BE ANOTHER
ROUND OF PRECIP MAINLY IN THE EAST AFTER MIDNIGHT INTO SUNDAY AS
THE UPPER SYSTEM OPENS UP AND LIFTS NORTHEAST. MODEL SOUNDINGS
SHOW VERY LITTLE INSTABILITY...MORE OR LESS MOIST ADIABATIC THRU
THE ENTIRE TROPOSPHERE. THIS HAS VERIFIED IN CURRENT
OBSERVATIONS...THE LIGHTNING ACTIVITY THAT PEAKED THIS MORNING HAS
WANED COMPLETELY OVER E OK/NW AR. WHILE I CAN`T RULE OUT AN
ISOLATED LIGHTNING STRIKE OR TWO...NOT SURE IT IS WORTHY OF
ISOLATED STORM MENTION AND THUS HAVE LEFT IT OUT FOR TONIGHT.
THE NORTHERN AND SOUTHERN STREAMS OF THE WESTERLIES ARE FORECAST
TO MERGE OVER THE NEXT 24 TO 48 HOURS...AS A DEEP LONGWAVE TROUGH
DEVELOPS OVER THE CENTRAL CONUS. AS THIS EVOLUTION IS UNDERWAY...A
STRONG SHORTWAVE TROUGH WILL DIVE SOUTHEAST OVER THE
CENTRAL/SOUTHERN PLAINS SUNDAY AFTERNOON AND EVENING. STRONG LOW-
MID LEVEL COLD FRONTOGENESIS AND QG LIFT WILL FOCUS A BAND OF
PRECIP FROM NE OK INTO NW AR...WITH THE BEST CHANCES NEAR THE KS
AND MO BORDERS. LOW TO MID LEVEL LAPSE RATES STEEPEN DURING THE
AFTERNOON...WITH THE NAM SHOWING 500-800 J/KG OF MUCAPE. HAVE
THROWN IN THUNDER MENTION FOR SUNDAY AFTERNOON AND EVENING BASED
ON THIS DATA. ONCE THIS SYSTEM PASSES US BY...THE FORECAST WILL BE
DRY THRU DAY 7.
MILD TONIGHT AND TOMORROW THEN TEMPS WILL TAIL OFF TO NEAR OR
SLIGHTLY BELOW AVERAGE EARLY NEXT WEEK. SHOULD SEE ANOTHER WARMING
TREND MIDWEEK AHEAD OF A SHALLOW COLD SURGE BY THE END OF NEXT
WEEK. THANKSGIVING WEEKEND TRAVEL STILL LOOKS OK BASED ON TODAY`S
DATA.
LACY
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 56 64 35 55 / 50 50 20 10
FSM 55 71 39 55 / 80 50 10 10
MLC 57 68 37 58 / 80 20 10 10
BVO 55 64 34 54 / 50 70 20 10
FYV 54 66 34 49 / 80 70 50 10
BYV 53 65 35 49 / 80 80 50 10
MKO 55 67 35 54 / 70 40 30 10
MIO 54 65 34 51 / 70 80 50 10
F10 55 66 36 56 / 80 30 20 10
HHW 57 71 38 59 / 80 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
LONG TERM....30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1054 PM EST SUN NOV 23 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL PUSH NORTHWARD THROUGH THE GREAT LAKES
LATE TONIGHT AND MONDAY. IT WILL BRING A SLUG OF RAIN THROUGH THE
STATE TONIGHT. VERY WARM AND EVEN NEAR-RECORD WARM TEMPERATURES
ARE EXPECTED OVER MUCH OF THE AREA MONDAY...BEFORE THE COLD AIR
FOLLOWING THE GREAT LAKES LOW MOVES ACROSS LATE MONDAY AND MONDAY
NIGHT. A DEEPENING AREA OF LOW PRESSURE WILL MOVE NORTHWARD ALONG
THE MID ATLANTIC COAST WEDNESDAY. THERE IS A LOW CONFIDENCE AS TO
WHAT THE EXACT PATH OF THIS STORM WILL BE. HOWEVER...THE EASTERN
THIRD TO HALF OF THE STATE COULD HAVE A SIGNIFICANT SNOWFALL. COLD
AIR WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
TEMPS HAVE LEVELED OFF OR EVEN CLIMBED UP TO SEVERAL DEG F ACROSS
THE SUSQ VALLEY AS THE SE BREEZE PICKED UP OVER THE PAST FEW
HOURS /AND BROKE THE VERY SHALLOW SFCBASED INVERSION/...WHILE A
SEVERAL DEG F DROP IN TEMP WAS NOTED FURTHER SOUTH AND WEST AS
RAIN BEGAN TO FALL THROUGH AND COOL THE INITIALLY VERY DRY LLVLS.
RAIN SHIELD IS MARCHING NORTH-NORTHEAST ON SCHEDULE ACROSS THE CWA
LATE THIS EVENING...WITH 100 POPS FOR ALL AREAS WITHIN THE
UPCOMING 6 HOURS.
MINOR MODIFICATIONS TO TEMPS AND RAINFALL AMTS WERE MADE FOR THE
OVERNIGHT.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
LOW PRESSURE WILL DEEPEN SIGNIFICANTLY TO JUST UNDER 980MB AS IT
MOVES ACROSS THE UPPER GREAT LAKES DURING THE DAY. THE WARM AIR
AND MOISTURE ADVECTION THANKS TO A STRONG LOW LEVEL JET TO THE
EAST OF THIS STORM WILL PEAK LATE TONIGHT. PWATS ARE 1.25 TO 1.5
INCHES AROUND 06Z. THE SPEED OF MOVEMENT OF THE RAIN SHOULD
PRECLUDE ANY CONCERNS FOR HEAVY RAIN. GENERAL 0.50 INCHES QPF IS
IN THE FCST. HOWEVER...SOME INSTABILITY COULD DEVELOP TONIGHT IN
THE FAR SE. HAVE ADDED THE CHC OF TSRA IN THE SE TO GO ALONG WITH
THE 100POP OF RAIN/SHOWERS.
WINDS ALOFT GET UP TO 50 KTS OVER THE CENTRAL MTNS...BUT THE
GENERAL STABILITY OVER THE BULK OF THE AREA SHOULD KEEP GUSTS DOWN
DURING THE NIGHT. THE EXCEPTION COULD BE THE HIGHER PEAKS IN THE
WEST WHICH COULD BE GUSTY /INTO THE 20 PLUS KT RANGE/ THROUGH THE
NIGHT. TEMPS WILL LIKELY LEVEL-OFF OR EVEN RISE LATER TONIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
SUBSIDENCE/DRYING IMMEDIATELY BEHIND THE OVERNIGHT WAVE WILL START
THE BREAK-UP OF THE CLOUDS FROM S-N. HOWEVER...THE AMBIENT
MOISTURE WILL BE HIGH IN THE LLVLS AND FLOW OUT OF THE SOUTH
THROUGH THE COLUMN WILL MAKE IT DIFFICULT TO CLEAR THE NORTHERN
HALF OF THE AREA TOO RAPIDLY. THE SOUTH WILL LIKELY GET SOME
DECENT CLEARING AND THE WARM AIR AHEAD OF THE COLD FRONT WILL PUSH
TEMPS TO NEAR-RECORD LEVELS ON MONDAY AFTERNOON. WILL KEEP THE
NUMBERS SLIGHTLY LOWER THAN RECORDS...THOUGH. THIS IS DUE TO THE
UNCERTAINTY OF HOW MUCH SUN TIME WE WILL HAVE. THE BIGGEST TEMP
BUST POTENTIAL AREA /STAY TOO COOL VS FCST/ WILL BE THE
NORTHEASTERN MTNS. THEY COULD STAY TOO CLOUDY. THE INSTABILITY
COULD ALSO TOUCH OFF A FEW SHOWERS -MAINLY IN THE CENTRAL AND
NORTH. THE COLD FRONT SHOULD MOVE THROUGH LATER IN THE DAY AND
EARLY EVENING.
THE WINDS WILL BE THE OTHER STORY - ALONG WITH THE TEMPS. THE
WESTERN MOUNTAINS/ALLEGHENIES WILL BE THE GUSTIEST PLACE. MIXED-
WINDS WITH LITTLE DIRECTIONAL SHEAR OFF BUFKIT SOUNDINGS MAKE FOR
WIND GUSTS EASILY INTO THE UPPER 30KT RANGE...LIKELY INCREASING TO
OCNLY 40-43 KTS IN THE LATE AFTERNOON AND NIGHT. A WIND ADVISORY
WAS RECENTLY ISSUED FOR 17Z MONDAY - 09Z TUESDAY FOR THE NW MTNS
AND LAUREL HIGHLANDS.
THE PERIOD OF LIKELY HIGHEST GUSTS APPEAR TO BE NEAR...AND FOR SEVERAL
HOURS IN THE WAKE OF THE CFROPA /OR FROM 21Z MONDAY TO 05Z
TUESDAY/.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
POTENTIAL FOR SIG WINTER IMPACTS FROM LOW PRESSURE MOVING UP THE
EAST COAST ON WED/WED NIGHT. WILL CONTINUE TO INJECT
INTERPRETATION OF THE LATEST MODEL GUIDANCE WITH EACH 3-HOURLY
UPDATE TO GUIDE DECISION SUPPORT LEADING UP TO THE PRIME TRAVEL
PERIOD FOR THE THANKSGIVING HOLIDAY.
HIGHLY AMPLIFIED AND ACTIVE UPPER AIR PATTERN WILL BRING A PERIOD
OF ACTIVE WEATHER THROUGH THE COMING WEEK. THE 500MB CONFIGURATION
WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE
WESTERN ATLANTIC WITH A FULL-LATITUDE PERSISTENT TROUGH EBBING
AND FLOWING OVER THE CENTRAL AND EASTERN U.S.
AFTER THE EXIT OF MONDAY/S LOW PRESSURE AREA...COLDER TEMPS
RETURN ON BRISK W/SW FLOW FOR TUE DROPPING HIGHS SOME 20-25F FROM
PREV DAYS READINGS. WE/LL ALSO SEE THE RETURN OF LIGHT SNOW
SHOWERS IN THE WESTERN HIGHER TERRAIN.
THEN FOCUS WILL TURN TO A WAVE CURRENTLY DROPPING SE FROM BRITISH
COLUMBIA AND WASHINGTON STATE...WHICH WILL SPAWN AN AREA OF LOW
PRESSURE OVER THE SE US TUESDAY NIGHT...THAT WILL LIKELY MOVE
NORTH NORTHEASTWARD JUST OFF THE EAST COAST WEDNESDAY INTO
THURSDAY.
12Z/18Z OPERATIONAL AND GEFS RUNS ALONG WITH THE 21Z SREF ARE
BECOMING FAIRLY WELL CLUSTERED WITH RESPECT TO THE LOCATION OF THE
NEAR...TO SUB-1000 MB SFC LOW EARLY WED EVENING /NEAR...AND UP TO
ABOUT 200 NM EAST OF DELMARVA PENINSULA/.
THERE IS STILL MUCH UNCERTAINTY AT THIS 60-72 HOUR TIMEFRAME
BEFORE THE EVENT...WITH RESPECT TO THE EXACT TRACK OF THE SFC LOW
AND ASSOCIATED SNOW/RAIN AMOUNTS.
COLD AIR WILL BE IN PLACE WED MORNING AS A /WEAK/ HIGH PRESSURE
RIDGE RETREATS TO THE NORTH AHEAD OF THE APPROACHING LOW.
NORTHERLY FLOW OVER CENTRAL PA NOT PARTICULARLY STRONG IN ANY
MODEL...BUT A SHORTWAVE LOOKS POISED TO SLIDE IN FROM THE GREAT
LAKES ON WED TO ADD SOME SYNOPTIC LIFT TO A RAPIDLY DEEPENING AND
FAST MOVING SURFACE LOW.
THE 12Z ECMWF AND IT`S ENSEMBLE ARE VERY SIMILAR HUGGING THE SFC
LOW ALONG THE SHORELINE...WHILE US/CANADIAN MODELS AND THEIR
ENSEMBLES ARE FURTHER EAST BY 100-200 NM. EXPERIENCE SHOWS THAT
THE LACK OF A SIGNIFICANT BLOCKING HIGH TO OUR NORTH OR
NORTHEAST...FAVORS A MORE WESTERN TRACK /SIMILAR TO THE EC AND ITS
ENSEMBLE/. SHOULD THE WWD TREND CONTINUE EVEN FURTHER WITH AN
EARLIER INJECTION OF NRN STREAM ENERGY INTO THE SOUTHERN STREAM
SYSTEM...IT/S CONCEIVABLE THAT OUR FAR SE ZONES /NEAR KLNS AND
KMDT/ COULD EVEN SEE A MIX WITH SLEET AND RAIN FOR A PERIOD THAT
WOULD HOLD DOWN ACCUMULATIONS.
PRECIP MAY START OFF EARLY WED AS A MIX OF RAIN AND SNOW IN THE
SE...BUT COOLING TEMPS ALOFT SHOULD CONVERT ALL PRECIP OVER TO
SNOW BY MIDDAY. AS IS A GENERAL RULE WITH THESE TYPES OF EVENTS...
THERE WILL LIKELY BE A SHARP DROPOFF IN ACCUMULATIONS ON THE NW
EDGE OF THE HEAVIER SNOWS. BIGGEST POTENTIAL IMPACTS IN OUR CWA
WILL BE THE CENTRAL MTNS AND SUSQ VALLEY...WHERE POTENTIAL FOR A
SEVERAL HOUR PERIOD OF HEAVY ACCUMULATING SNOW WILL EXIST. BUT
AGAIN...SMALL CHANGES IN THE ULTIMATE TRACK COULD LEAD TO
MODIFICATIONS OF SNOWFALL FORECASTS. THE TAKE AWAY...THOUGH THE
DETAILS REMAIN UNCERTAIN...THERE WILL BE SIG IMPACTS TO TRAVEL
ALONG THE U.S. EAST COAST ON ONE OF THE BUSIEST DAYS OF THE YEAR
/WED/. PLAN ACCORDINGLY.
COLDER AIR REMAINS IN PLACE LATE IN THE WEEK AS SCT SNOW SHOWERS
RETURN TO THE WESTERN HIGHER TERRAIN. TEMPS LOOK TO GRADUALLY
MODIFY LATE WEEKEND HEADING INTO NEXT WEEK...WITH NO BIG STORM
SYSTEMS EXPECTED AFTER THANKSGIVING.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
A LOW PRES SYSTEM TRACKING NORTHWARD INTO THE GRT LKS WILL SPREAD
LOWERING CIGS AND RAIN ACROSS CENTRAL PA TONIGHT. REGIONAL RADAR
AT 00Z SHOWS THE RAIN ABOUT TO ENTER SOUTHERN PA AND LINEAR
EXTRAPOLATION SUGGESTS THE RAIN WILL OVERSPREAD ALL CENTRAL PA
AIRFIELDS BTWN 02Z-04Z. A BLEND OF LATEST LAMP GUIDANCE...SREF AND
HRRR MDL OUTPUT IMPLY CIGS WILL DROP TO IFR BTWN 04Z-06Z...JUST A
COUPLE HOURS AFTER THE RAIN BEGINS.
SOUTHERLY WINDS IN THE 1-2 KFT LAYER WILL BECOME VERY STRONG
OVERNIGHT...MAKING LLWS A NEAR CERTAINTY. SFC GUSTS OVERNIGHT WILL
BE HIGHEST AT KJST DUE TO IT/S RIDGETOP LOCATION. HRRR OUTPUT
SUGGESTS GUSTS BTWN 25-35KTS ARE POSS THERE BTWN 03Z-07Z. MUCH
LIGHTER SFC WINDS EXPECTED ELSEWHERE...WHICH WILL LEAD TO THE
LLWS.
EARLY LOW CIGS AND LINGERING DRIZZLE WILL GIVE WAY TO IMPROVING
CONDS BY LATE MONDAY AM...AS WARM FRONT LIFTS NORTH OF THE
REGION. GENERALLY VFR CONDS ARE ANTICIPATED MON AFTN. HOWEVER...A
COLD FRONT MOVING FROM THE WEST WILL BE ACCOMPANIED BY SCT LATE
DAY SHRA ACROSS THE W MTNS...POSSIBLY PRODUCING A BRIEF VSBY
REDUCTION AT KBFD OR KJST.
OUTLOOK...
TUE...NO SIG WX EXPECTED.
WED...SNOW/LOW VSBYS POSS EASTERN PA.
THU...-SHSN/REDUCED VSBYS POSS NW MTNS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON MONDAY TO 4 AM EST TUESDAY FOR
PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1036 PM EST SUN NOV 23 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL PUSH NORTHWARD THROUGH THE GREAT LAKES
LATE TONIGHT AND MONDAY. IT WILL BRING A SLUG OF RAIN THROUGH THE
STATE TONIGHT. VERY WARM AND EVEN NEAR-RECORD WARM TEMPERATURES
ARE EXPECTED OVER MUCH OF THE AREA MONDAY...BEFORE THE COLD AIR
FOLLOWING THE GREAT LAKES LOW MOVES ACROSS LATE MONDAY AND MONDAY
NIGHT. A DEEPENING AREA OF LOW PRESSURE WILL MOVE NORTHWARD ALONG
THE MID ATLANTIC COAST WEDNESDAY. THERE IS A LOW CONFIDENCE AS TO
WHAT THE EXACT PATH OF THIS STORM WILL BE. HOWEVER...THE EASTERN
THIRD TO HALF OF THE STATE COULD HAVE A SIGNIFICANT SNOWFALL. COLD
AIR WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
TEMPS WERE TRIMMED BY SEVERAL DEG F ACROSS THE SUSQ VALLEY THROUGH
THE EARLY NIGHTTIME HOURS...BEFORE SOUTHEASTERLY WINDS INCREASE
TO BREAK THE SHALLOW SFC BASED INVERSION.
OTHERWISE...ONLY MINOR MODIFICATIONS WERE MADE TO TEMPS AND THE
ONSET TIMING OF RAIN ARRIVING FROM THE SSW TONIGHT.
DID POST A WIND ADVISORY FOR THE WESTERN MTNS BEGINNING AT 17Z
MONDAY AND CONTINUING UNTIL ABOUT 10 HOURS AFTER THE CFROPA
/ENDING 09Z TUESDAY/.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
LOW PRESSURE WILL DEEPEN SIGNIFICANTLY TO JUST UNDER 980MB AS IT
MOVES ACROSS THE UPPER GREAT LAKES DURING THE DAY. THE WARM AIR
AND MOISTURE ADVECTION THANKS TO A STRONG LOW LEVEL JET TO THE
EAST OF THIS STORM WILL PEAK LATE TONIGHT. PWATS ARE 1.25 TO 1.5
INCHES AROUND 06Z. THE SPEED OF MOVEMENT OF THE RAIN SHOULD
PRECLUDE ANY CONCERNS FOR HEAVY RAIN. GENERAL 0.50 INCHES QPF IS
IN THE FCST. HOWEVER...SOME INSTABILITY COULD DEVELOP TONIGHT IN
THE FAR SE. HAVE ADDED THE CHC OF TSRA IN THE SE TO GO ALONG WITH
THE 100POP OF RAIN/SHOWERS.
WINDS ALOFT GET UP TO 50 KTS OVER THE CENTRAL MTNS...BUT THE
GENERAL STABILITY OVER THE BULK OF THE AREA SHOULD KEEP GUSTS DOWN
DURING THE NIGHT. THE EXCEPTION COULD BE THE HIGHER PEAKS IN THE
WEST WHICH COULD BE GUSTY /INTO THE 20 PLUS KT RANGE/ THROUGH THE
NIGHT. TEMPS WILL LIKELY LEVEL-OFF OR EVEN RISE LATER TONIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
SUBSIDENCE/DRYING IMMEDIATELY BEHIND THE OVERNIGHT WAVE WILL START
THE BREAK-UP OF THE CLOUDS FROM S-N. HOWEVER...THE AMBIENT
MOISTURE WILL BE HIGH IN THE LLVLS AND FLOW OUT OF THE SOUTH
THROUGH THE COLUMN WILL MAKE IT DIFFICULT TO CLEAR THE NORTHERN
HALF OF THE AREA TOO RAPIDLY. THE SOUTH WILL LIKELY GET SOME
DECENT CLEARING AND THE WARM AIR AHEAD OF THE COLD FRONT WILL PUSH
TEMPS TO NEAR-RECORD LEVELS ON MONDAY AFTERNOON. WILL KEEP THE
NUMBERS SLIGHTLY LOWER THAN RECORDS...THOUGH. THIS IS DUE TO THE
UNCERTAINTY OF HOW MUCH SUN TIME WE WILL HAVE. THE BIGGEST TEMP
BUST POTENTIAL AREA /STAY TOO COOL VS FCST/ WILL BE THE
NORTHEASTERN MTNS. THEY COULD STAY TOO CLOUDY. THE INSTABILITY
COULD ALSO TOUCH OFF A FEW SHOWERS -MAINLY IN THE CENTRAL AND
NORTH. THE COLD FRONT SHOULD MOVE THROUGH LATER IN THE DAY AND
EARLY EVENING.
THE WINDS WILL BE THE OTHER STORY - ALONG WITH THE TEMPS. THE
WESTERN MOUNTAINS/ALLEGHENIES WILL BE THE GUSTIEST PLACE. MIXED-
WINDS WITH LITTLE DIRECTIONAL SHEAR OFF BUFKIT SOUNDINGS MAKE FOR
WIND GUSTS EASILY INTO THE UPPER 30KT RANGE...LIKELY INCREASING TO
OCNLY 40-43 KTS IN THE LATE AFTERNOON AND NIGHT. A WIND ADVISORY
WAS RECENTLY ISSUED FOR 17Z MONDAY - 09Z TUESDAY FOR THE NW MTNS
AND LAUREL HIGHLANDS.
THE PERIOD OF LIKELY HIGHEST GUSTS APPEAR TO BE NEAR...AND FOR SEVERAL
HOURS IN THE WAKE OF THE CFROPA /OR FROM 21Z MONDAY TO 05Z
TUESDAY/.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
POTENTIAL FOR SIG WINTER IMPACTS FROM LOW PRESSURE MOVING UP THE
EAST COAST ON WED/WED NIGHT. WILL CONTINUE TO INJECT
INTERPRETATION OF THE LATEST MODEL GUIDANCE WITH EACH 3-HOURLY
UPDATE TO GUIDE DECISION SUPPORT LEADING UP TO THE PRIME TRAVEL
PERIOD FOR THE THANKSGIVING HOLIDAY.
HIGHLY AMPLIFIED AND ACTIVE UPPER AIR PATTERN WILL BRING A PERIOD
OF ACTIVE WEATHER THROUGH THE COMING WEEK. THE 500MB CONFIGURATION
WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE
WESTERN ATLANTIC WITH A FULL-LATITUDE PERSISTENT TROUGH EBBING
AND FLOWING OVER THE CENTRAL AND EASTERN U.S.
AFTER THE EXIT OF MONDAY/S LOW PRESSURE AREA...COLDER TEMPS
RETURN ON BRISK W/SW FLOW FOR TUE DROPPING HIGHS SOME 20-25F FROM
PREV DAYS READINGS. WE/LL ALSO SEE THE RETURN OF LIGHT SNOW
SHOWERS IN THE WESTERN HIGHER TERRAIN.
THEN FOCUS WILL TURN TO A WAVE CURRENTLY DROPPING SE FROM BRITISH
COLUMBIA AND WASHINGTON STATE...WHICH WILL SPAWN AN AREA OF LOW
PRESSURE OVER THE SE US TUESDAY NIGHT...THAT WILL LIKELY MOVE
NORTH NORTHEASTWARD JUST OFF THE EAST COAST WEDNESDAY INTO
THURSDAY.
12Z/18Z OPERATIONAL AND GEFS RUNS ALONG WITH THE 21Z SREF ARE
BECOMING FAIRLY WELL CLUSTERED WITH RESPECT TO THE LOCATION OF THE
NEAR...TO SUB-1000 MB SFC LOW EARLY WED EVENING /NEAR...AND UP TO
ABOUT 200 NM EAST OF DELMARVA PENINSULA/.
THERE IS STILL MUCH UNCERTAINTY AT THIS 60-72 HOUR TIMEFRAME
BEFORE THE EVENT...WITH RESPECT TO THE EXACT TRACK OF THE SFC LOW
AND ASSOCIATED SNOW/RAIN AMOUNTS.
COLD AIR WILL BE IN PLACE WED MORNING AS A /WEAK/ HIGH PRESSURE
RIDGE RETREATS TO THE NORTH AHEAD OF THE APPROACHING LOW.
NORTHERLY FLOW OVER CENTRAL PA NOT PARTICULARLY STRONG IN ANY
MODEL...BUT A SHORTWAVE LOOKS POISED TO SLIDE IN FROM THE GREAT
LAKES ON WED TO ADD SOME SYNOPTIC LIFT TO A RAPIDLY DEEPENING AND
FAST MOVING SURFACE LOW.
THE 12Z ECMWF AND IT`S ENSEMBLE ARE VERY SIMILAR HUGGING THE SFC
LOW ALONG THE SHORELINE...WHILE US/CANADIAN MODELS AND THEIR
ENSEMBLES ARE FURTHER EAST BY 100-200 NM. EXPERIENCE SHOWS THAT
THE LACK OF A SIGNIFICANT BLOCKING HIGH TO OUR NORTH OR
NORTHEAST...FAVORS A MORE WESTERN TRACK /SIMILAR TO THE EC AND ITS
ENSEMBLE/. SHOULD THE WWD TREND CONTINUE EVEN FURTHER WITH AN
EARLIER INJECTION OF NRN STREAM ENERGY INTO THE SOUTHERN STREAM
SYSTEM...IT/S CONCEIVABLE THAT OUR FAR SE ZONES /NEAR KLNS AND
KMDT/ COULD EVEN SEE A MIX WITH SLEET AND RAIN FOR A PERIOD THAT
WOULD HOLD DOWN ACCUMULATIONS.
PRECIP MAY START OFF EARLY WED AS A MIX OF RAIN AND SNOW IN THE
SE...BUT COOLING TEMPS ALOFT SHOULD CONVERT ALL PRECIP OVER TO
SNOW BY MIDDAY. AS IS A GENERAL RULE WITH THESE TYPES OF EVENTS...
THERE WILL LIKELY BE A SHARP DROPOFF IN ACCUMULATIONS ON THE NW
EDGE OF THE HEAVIER SNOWS. BIGGEST POTENTIAL IMPACTS IN OUR CWA
WILL BE THE CENTRAL MTNS AND SUSQ VALLEY...WHERE POTENTIAL FOR A
SEVERAL HOUR PERIOD OF HEAVY ACCUMULATING SNOW WILL EXIST. BUT
AGAIN...SMALL CHANGES IN THE ULTIMATE TRACK COULD LEAD TO
MODIFICATIONS OF SNOWFALL FORECASTS. THE TAKE AWAY...THOUGH THE
DETAILS REMAIN UNCERTAIN...THERE WILL BE SIG IMPACTS TO TRAVEL
ALONG THE U.S. EAST COAST ON ONE OF THE BUSIEST DAYS OF THE YEAR
/WED/. PLAN ACCORDINGLY.
COLDER AIR REMAINS IN PLACE LATE IN THE WEEK AS SCT SNOW SHOWERS
RETURN TO THE WESTERN HIGHER TERRAIN. TEMPS LOOK TO GRADUALLY
MODIFY LATE WEEKEND HEADING INTO NEXT WEEK...WITH NO BIG STORM
SYSTEMS EXPECTED AFTER THANKSGIVING.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
A LOW PRES SYSTEM TRACKING NORTHWARD INTO THE GRT LKS WILL SPREAD
LOWERING CIGS AND RAIN ACROSS CENTRAL PA TONIGHT. REGIONAL RADAR
AT 03Z SHOWS THE RAIN HAS OVERSPREAD THE SW HALF OF THE STATE AND
LINEAR EXTRAPOLATION SUGGESTS IT WILL REACH THE REST OF CENTRAL
PA BTWN 04Z-05Z. A BLEND OF LATEST LAMP GUIDANCE...SREF AND HRRR
MDL OUTPUT IMPLY CIGS WILL DROP TO IFR BTWN 04Z-06Z...JUST A
COUPLE HOURS AFTER THE RAIN BEGINS.
SOUTHERLY WINDS IN THE 1-2 KFT LAYER WILL BECOME VERY STRONG
OVERNIGHT...MAKING LLWS A NEAR CERTAINTY. SFC GUSTS OVERNIGHT WILL
BE HIGHEST AT KJST DUE TO IT/S RIDGETOP LOCATION. HRRR OUTPUT
SUGGESTS GUSTS BTWN 25-35KTS ARE POSS THERE BTWN 03Z-07Z. MUCH
LIGHTER SFC WINDS EXPECTED ELSEWHERE...WHICH WILL LEAD TO THE
LLWS.
EARLY LOW CIGS AND LINGERING DRIZZLE WILL GIVE WAY TO IMPROVING
CONDS BY LATE MONDAY AM...AS WARM FRONT LIFTS NORTH OF THE
REGION. GENERALLY VFR CONDS ARE ANTICIPATED MON AFTN. HOWEVER...A
COLD FRONT MOVING FROM THE WEST WILL BE ACCOMPANIED BY SCT LATE
DAY SHRA ACROSS THE W MTNS...POSSIBLY PRODUCING A BRIEF VSBY
REDUCTION AT KBFD OR KJST.
OUTLOOK...
TUE...NO SIG WX EXPECTED.
WED...SNOW/LOW VSBYS POSS EASTERN PA.
THU...-SHSN/REDUCED VSBYS POSS NW MTNS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON MONDAY TO 4 AM EST TUESDAY FOR
PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
859 PM EST SUN NOV 23 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL PUSH NORTHWARD THROUGH THE GREAT LAKES
LATE TONIGHT AND MONDAY. IT WILL BRING A SLUG OF RAIN THROUGH THE
STATE TONIGHT. VERY WARM AND EVEN NEAR-RECORD WARM TEMPERATURES
ARE EXPECTED OVER MUCH OF THE AREA MONDAY...BEFORE THE COLD AIR
FOLLOWING THE GREAT LAKES LOW MOVES ACROSS LATE MONDAY AND MONDAY
NIGHT. A DEEPENING AREA OF LOW PRESSURE WILL MOVE NORTHWARD ALONG
THE MID ATLANTIC COAST WEDNESDAY. THERE IS A LOW CONFIDENCE AS TO
WHAT THE EXACT PATH OF THIS STORM WILL BE. HOWEVER...THE EASTERN
THIRD TO HALF OF THE STATE COULD HAVE A SIGNIFICANT SNOWFALL. COLD
AIR WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
TEMPS WERE TRIMMED BY SEVERAL DEG F ACROSS THE SUSQ VALLEY THROUGH
THE EARLY NIGHTTIME HOURS...BEFORE SOUTHEASTERLY WINDS INCREASE
TO BREAK THE SHALLOW SFC BASED INVERSION.
OTHERWISE...ONLY MINOR MODIFICATIONS WERE MADE TO TEMPS AND THE
ONSET TIMING OF RAIN ARRIVING FROM THE SSW TONIGHT.
DID POST A WIND ADVISORY FOR THE WESTERN MTNS BEGINNING AT 17Z
MONDAY AND CONTINUING UNTIL ABOUT 10 HOURS AFTER THE CFROPA
/ENDING 09Z TUESDAY/.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
LOW PRESSURE WILL DEEPEN SIGNIFICANTLY TO JUST UNDER 980MB AS IT
MOVES ACROSS THE UPPER GREAT LAKES DURING THE DAY. THE WARM AIR
AND MOISTURE ADVECTION THANKS TO A STRONG LOW LEVEL JET TO THE
EAST OF THIS STORM WILL PEAK LATE TONIGHT. PWATS ARE 1.25 TO 1.5
INCHES AROUND 06Z. THE SPEED OF MOVEMENT OF THE RAIN SHOULD
PRECLUDE ANY CONCERNS FOR HEAVY RAIN. GENERAL 0.50 INCHES QPF IS
IN THE FCST. HOWEVER...SOME INSTABILITY COULD DEVELOP TONIGHT IN
THE FAR SE. HAVE ADDED THE CHC OF TSRA IN THE SE TO GO ALONG WITH
THE 100POP OF RAIN/SHOWERS.
WINDS ALOFT GET UP TO 50 KTS OVER THE CENTRAL MTNS...BUT THE
GENERAL STABILITY OVER THE BULK OF THE AREA SHOULD KEEP GUSTS DOWN
DURING THE NIGHT. THE EXCEPTION COULD BE THE HIGHER PEAKS IN THE
WEST WHICH COULD BE GUSTY /INTO THE 20 PLUS KT RANGE/ THROUGH THE
NIGHT. TEMPS WILL LIKELY LEVEL-OFF OR EVEN RISE LATER TONIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
SUBSIDENCE/DRYING IMMEDIATELY BEHIND THE OVERNIGHT WAVE WILL START
THE BREAK-UP OF THE CLOUDS FROM S-N. HOWEVER...THE AMBIENT
MOISTURE WILL BE HIGH IN THE LLVLS AND FLOW OUT OF THE SOUTH
THROUGH THE COLUMN WILL MAKE IT DIFFICULT TO CLEAR THE NORTHERN
HALF OF THE AREA TOO RAPIDLY. THE SOUTH WILL LIKELY GET SOME
DECENT CLEARING AND THE WARM AIR AHEAD OF THE COLD FRONT WILL PUSH
TEMPS TO NEAR-RECORD LEVELS ON MONDAY AFTERNOON. WILL KEEP THE
NUMBERS SLIGHTLY LOWER THAN RECORDS...THOUGH. THIS IS DUE TO THE
UNCERTAINTY OF HOW MUCH SUN TIME WE WILL HAVE. THE BIGGEST TEMP
BUST POTENTIAL AREA /STAY TOO COOL VS FCST/ WILL BE THE
NORTHEASTERN MTNS. THEY COULD STAY TOO CLOUDY. THE INSTABILITY
COULD ALSO TOUCH OFF A FEW SHOWERS -MAINLY IN THE CENTRAL AND
NORTH. THE COLD FRONT SHOULD MOVE THROUGH LATER IN THE DAY AND
EARLY EVENING.
THE WINDS WILL BE THE OTHER STORY - ALONG WITH THE TEMPS. THE
WESTERN MOUNTAINS/ALLEGHENIES WILL BE THE GUSTIEST PLACE. MIXED-
WINDS WITH LITTLE DIRECTIONAL SHEAR OFF BUFKIT SOUNDINGS MAKE FOR
WIND GUSTS EASILY INTO THE UPPER 30KT RANGE...LIKELY INCREASING TO
OCNLY 40-43 KTS IN THE LATE AFTERNOON AND NIGHT. A WIND ADVISORY
WAS RECENTLY ISSUED FOR 17Z MONDAY - 09Z TUESDAY FOR THE NW MTNS
AND LAUREL HIGHLANDS.
THE PERIOD OF LIKELY HIGHEST GUSTS APPEAR TO BE NEAR...AND FOR SEVERAL
HOURS IN THE WAKE OF THE CFROPA /OR FROM 21Z MONDAY TO 05Z
TUESDAY/.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
POTENTIAL FOR SIG WINTER IMPACTS FROM LOW PRESSURE MOVING UP THE
EAST COAST ON WED/WED NIGHT. WILL CONTINUE TO INJECT
INTERPRETATION OF THE LATEST MODEL GUIDANCE WITH EACH 3-HOURLY
UPDATE TO GUIDE DECISION SUPPORT LEADING UP TO THE PRIME TRAVEL
PERIOD FOR THE THANKSGIVING HOLIDAY.
HIGHLY AMPLIFIED AND ACTIVE UPPER AIR PATTERN WILL BRING A PERIOD
OF ACTIVE WEATHER THROUGH THE COMING WEEK. THE 500MB CONFIGURATION
WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE
WESTERN ATLANTIC WITH A FULL-LATITUDE PERSISTENT TROUGH EBBING
AND FLOWING OVER THE CENTRAL AND EASTERN U.S.
AFTER THE EXIT OF MONDAY/S LOW PRESSURE AREA...COLDER TEMPS
RETURN ON BRISK W/SW FLOW FOR TUE DROPPING HIGHS SOME 20-25F FROM
PREV DAYS READINGS. WE/LL ALSO SEE THE RETURN OF LIGHT SNOW
SHOWERS IN THE WESTERN HIGHER TERRAIN.
THEN FOCUS WILL TURN TO A WAVE CURRENTLY DROPPING SE FROM BRITISH
COLUMBIA AND WASHINGTON STATE...WHICH WILL SPAWN AN AREA OF LOW
PRESSURE OVER THE SE US TUESDAY NIGHT...THAT WILL LIKELY MOVE
NORTH NORTHEASTWARD JUST OFF THE EAST COAST WEDNESDAY INTO
THURSDAY.
12Z/18Z OPERATIONAL AND GEFS RUNS ALONG WITH THE 21Z SREF ARE
BECOMING FAIRLY WELL CLUSTERED WITH RESPECT TO THE LOCATION OF THE
NEAR...TO SUB-1000 MB SFC LOW EARLY WED EVENING /NEAR...AND UP TO
ABOUT 200 NM EAST OF DELMARVA PENINSULA/.
THERE IS STILL MUCH UNCERTAINTY AT THIS 60-72 HOUR TIMEFRAME
BEFORE THE EVENT...WITH RESPECT TO THE EXACT TRACK OF THE SFC LOW
AND ASSOCIATED SNOW/RAIN AMOUNTS.
COLD AIR WILL BE IN PLACE WED MORNING AS A /WEAK/ HIGH PRESSURE
RIDGE RETREATS TO THE NORTH AHEAD OF THE APPROACHING LOW.
NORTHERLY FLOW OVER CENTRAL PA NOT PARTICULARLY STRONG IN ANY
MODEL...BUT A SHORTWAVE LOOKS POISED TO SLIDE IN FROM THE GREAT
LAKES ON WED TO ADD SOME SYNOPTIC LIFT TO A RAPIDLY DEEPENING AND
FAST MOVING SURFACE LOW.
THE 12Z ECMWF AND IT`S ENSEMBLE ARE VERY SIMILAR HUGGING THE SFC
LOW ALONG THE SHORELINE...WHILE US/CANADIAN MODELS AND THEIR
ENSEMBLES ARE FURTHER EAST BY 100-200 NM. EXPERIENCE SHOWS THAT
THE LACK OF A SIGNIFICANT BLOCKING HIGH TO OUR NORTH OR
NORTHEAST...FAVORS A MORE WESTERN TRACK /SIMILAR TO THE EC AND ITS
ENSEMBLE/. SHOULD THE WWD TREND CONTINUE EVEN FURTHER WITH AN
EARLIER INJECTION OF NRN STREAM ENERGY INTO THE SOUTHERN STREAM
SYSTEM...IT/S CONCEIVABLE THAT OUR FAR SE ZONES /NEAR KLNS AND
KMDT/ COULD EVEN SEE A MIX WITH SLEET AND RAIN FOR A PERIOD THAT
WOULD HOLD DOWN ACCUMULATIONS.
PRECIP MAY START OFF EARLY WED AS A MIX OF RAIN AND SNOW IN THE
SE...BUT COOLING TEMPS ALOFT SHOULD CONVERT ALL PRECIP OVER TO
SNOW BY MIDDAY. AS IS A GENERAL RULE WITH THESE TYPES OF EVENTS...
THERE WILL LIKELY BE A SHARP DROPOFF IN ACCUMULATIONS ON THE NW
EDGE OF THE HEAVIER SNOWS. BIGGEST POTENTIAL IMPACTS IN OUR CWA
WILL BE THE CENTRAL MTNS AND SUSQ VALLEY...WHERE POTENTIAL FOR A
SEVERAL HOUR PERIOD OF HEAVY ACCUMULATING SNOW WILL EXIST. BUT
AGAIN...SMALL CHANGES IN THE ULTIMATE TRACK COULD LEAD TO
MODIFICATIONS OF SNOWFALL FORECASTS. THE TAKE AWAY...THOUGH THE
DETAILS REMAIN UNCERTAIN...THERE WILL BE SIG IMPACTS TO TRAVEL
ALONG THE U.S. EAST COAST ON ONE OF THE BUSIEST DAYS OF THE YEAR
/WED/. PLAN ACCORDINGLY.
COLDER AIR REMAINS IN PLACE LATE IN THE WEEK AS SCT SNOW SHOWERS
RETURN TO THE WESTERN HIGHER TERRAIN. TEMPS LOOK TO GRADUALLY
MODIFY LATE WEEKEND HEADING INTO NEXT WEEK...WITH NO BIG STORM
SYSTEMS EXPECTED AFTER THANKSGIVING.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
A LOW PRES SYSTEM TRACKING NORTHWARD INTO THE GRT LKS WILL SPREAD
LOWERING CIGS AND RAIN ACROSS CENTRAL PA TONIGHT. REGIONAL RADAR
AT 00Z SHOWS THE RAIN ABOUT TO ENTER SOUTHERN PA AND LINEAR
EXTRAPOLATION SUGGESTS THE RAIN WILL OVERSPREAD ALL CENTRAL PA
AIRFIELDS BTWN 02Z-04Z. A BLEND OF LATEST LAMP GUIDANCE...SREF AND
HRRR MDL OUTPUT IMPLY CIGS WILL DROP TO IFR BTWN 04Z-06Z...JUST A
COUPLE HOURS AFTER THE RAIN BEGINS.
SOUTHERLY WINDS IN THE 1-2 KFT LAYER WILL BECOME VERY STRONG
OVERNIGHT...MAKING LLWS A NEAR CERTAINTY. SFC GUSTS OVERNIGHT WILL
BE HIGHEST AT KJST DUE TO IT/S RIDGETOP LOCATION. HRRR OUTPUT
SUGGESTS GUSTS BTWN 25-35KTS ARE POSS THERE BTWN 03Z-07Z. MUCH
LIGHTER SFC WINDS EXPECTED ELSEWHERE...WHICH WILL LEAD TO THE
LLWS.
EARLY LOW CIGS AND LINGERING DRIZZLE WILL GIVE WAY TO IMPROVING
CONDS BY LATE MONDAY AM...AS WARM FRONT LIFTS NORTH OF THE
REGION. GENERALLY VFR CONDS ARE ANTICIPATED MON AFTN. HOWEVER...A
COLD FRONT MOVING FROM THE WEST WILL BE ACCOMPANIED BY SCT LATE
DAY SHRA ACROSS THE W MTNS...POSSIBLY PRODUCING A BRIEF VSBY
REDUCTION AT KBFD OR KJST.
OUTLOOK...
TUE...NO SIG WX EXPECTED.
WED...SNOW/LOW VSBYS POSS EASTERN PA.
THU...-SHSN/REDUCED VSBYS POSS NW MTNS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON MONDAY TO 4 AM EST TUESDAY FOR
PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...LAMBERT/DANGELO
NEAR TERM...LAMBERT/DANGELO
SHORT TERM...LAMBERT/DANGELO
LONG TERM...LAMBERT/RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
729 PM EST SUN NOV 23 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL PUSH NORTHWARD THROUGH THE GREAT LAKES
TONIGHT AND MONDAY. IT WILL BRING A SLUG OF RAIN THROUGH THE STATE
TONIGHT. VERY WARM AND EVEN NEAR-RECORD WARM TEMPERATURES ARE
EXPECTED OVER MUCH OF THE AREA MONDAY...BEFORE THE COLD AIR
FOLLOWING THE GREAT LAKES LOW MOVES ACROSS LATE MONDAY AND MONDAY
NIGHT. A DEEPENING AREA OF LOW PRESSURE WILL MOVE NORTHWARD ALONG
THE MID ATLANTIC COAST WEDNESDAY. THERE IS A LOW CONFIDENCE AS TO
WHAT THE EXACT PATH OF THIS STORM WILL BE. HOWEVER...THE EASTERN
THIRD TO HALF OF THE STATE COULD HAVE A SIGNIFICANT SNOWFALL.
COLD AIR WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
LOW PRESSURE WILL DEEPEN SIGNIFICANTLY TO LESS THAN 980MB AS IT
MOVES ACROSS THE UPPER GREAT LAKES ON MONDAY. THE WARM AIR AND
MOISTURE ADVECTION THANKS TO A STRONG LOW LEVEL JET TO THE EAST
OF THIS STORM WILL PEAK LATE TONIGHT. PWATS ARE 1.25 TO 1.5
INCHES AROUND 06Z. THE SPEED OF MOVEMENT OF THE RAIN SHOULD
PRECLUDE ANY CONCERNS FOR HEAVY RAIN. GENERAL 0.50 INCHES QPF IS
IN THE FCST. HOWEVER...SOME INSTABILITY COULD DEVELOP TONIGHT IN
THE FAR SE. HAVE ADDED A CHC MENTION OF TSRA IN THE SE TO GO
ALONG WITH THE 100POP OF RAIN/SHOWERS. WINDS ALOFT GET UP TO 50
KTS OVER THE CENTRAL MTNS...BUT THE GENERAL STABILITY OVER THE
BULK OF THE AREA SHOULD KEEP GUSTS DOWN DURING THE NIGHT. THE
EXCEPTION COULD BE THE HIGHER PEAKS IN THE WEST WHICH COULD BE
GUSTY THROUGH THE NIGHT. TEMPS WILL LIKELY FALL A FEW DEGS THIS
EVENING BEFORE LEVELING OFF OR EVEN RISING LATER TONIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
SUBSIDENCE/DRYING IMMEDIATELY BEHIND THE OVERNIGHT WAVE WILL START
THE BREAK-UP OF THE CLOUDS FROM S-N. HOWEVER...THE AMBIENT
MOISTURE WILL BE HIGH IN THE LLVLS AND FLOW OUT OF THE SOUTH
THROUGH THE COLUMN WILL MAKE IT DIFFICULT TO CLEAR THE NORTHERN
HALF OF THE AREA TOO RAPIDLY. THE SOUTH WILL LIKELY GET SOME
DECENT CLEARING AND THE WARM AIR AHEAD OF THE COLD FRONT WILL PUSH
TEMPS TO NEAR-RECORD LEVELS ON MONDAY AFTERNOON. WILL KEEP THE
NUMBERS SLIGHTLY LOWER THAN RECORDS...THOUGH. THIS IS DUE TO THE
UNCERTAINTY OF HOW MUCH SUN TIME WE WILL HAVE. THE BIGGEST TEMP
BUST POTENTIAL AREA /STAY TOO COOL VS FCST/ WILL BE THE
NORTHEASTERN MTNS. THEY COULD STAY TOO CLOUDY. THE INSTABILITY
COULD ALSO TOUCH OFF A FEW SHOWERS -MAINLY IN THE CENTRAL AND
NORTH. THE COLD FRONT SHOULD MOVE THROUGH LATER IN THE DAY AND
EARLY EVENING.
THE WINDS WILL BE THE OTHER STORY - ALONG WITH THE TEMPS. THE
WESTERN MOUNTAINS/ALLEGHENIES WILL BE THE GUSTIEST PLACE. MIXED-
WINDS WITH LITTLE DIRECTIONAL SHEAR OFF BUFKIT SOUNDS MAKE FOR
WIND GUSTS EASILY INTO THE 30S. WILL KEEP THE GUSTS BELOW 40KTS
FOR NOW.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
POTENTIAL FOR SIG WINTER IMPACTS FROM LOW PRESSURE MOVING UP THE
EAST COAST ON WED/WED NIGHT.
HIGHLY AMPLIFIED AND ACTIVE UPPER AIR PATTERN WILL BRING A PERIOD
OF ACTIVE WEATHER THROUGH THE COMING WEEK. THE 500MB CONFIGURATION
WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE
WESTERN ATLANTIC WITH A FULL-LATITUDE PERSISTANT TROUGH EBBING
AND FLOWING OVER THE CENTRAL AND EASTERN U.S.
AFTER THE EXIT OF MONDAY/S LOW PRESSURE AREA...COLDER TEMPS
RETURN ON BRISK W/SW FLOW FOR TUE DROPPING HIGHS SOME 20-25F FROM
PREV DAYS READINGS. WE/LL ALSO SEE THE RETURN OF LIGHT SNOW
SHOWERS IN THE WESTERN HIGHER TERRAIN.
THEN FOCUS WILL TURN TO A WAVE CURRENTLY DROPPING SE FROM BRITISH
COLUMBIA...WHICH WILL SPAWN A COASTAL MID ATLANTIC LOW THAT WILL
MOVE NORTHWARD JUST OFF THE EAST COAST WEDNESDAY INTO THURSDAY.
00Z/12Z MODEL RUNS CONTINUING ONGOING TREND OF ECMWF TRACKING
FURTHER WESTWARD THAN THE GFS/GEFS...WITH A SLIGHT OVERALL DRIFT
WESTWARD BY NEARLY ALL GUIDANCE OVER PAST 24HRS. KEEP IN MIND THAT
THOUGH FORECAST CONFIDENCE IN THE DEVELOPMENT OF THIS COASTAL LOW
IS HIGH...THE TRACK CONTINUES TO HAVE A LARGE DEGREE OF
UNCERTAINTY. THE LATEST MODEL GUIDANCE INDICATES THAT THE
POTENTIAL HAS INCREASED FOR POTENTIAL SIG SNOWFALL OVER EASTERN
THIRD OF PA WED/WED EVE. COLD AIR WILL BE IN PLACE WED MORNING AS
A WEAK HIGH PRESSURE RIDGE RETREATS TO THE NORTH AHEAD OF THE
APPROACHING LOW. NORTHERLY FLOW OVER CENTRAL PA NOT PARTICULARLY
STRONG IN ANY MODEL...BUT A SHORTWAVE LOOKS POISED TO SLIDE IN
FROM THE GREAT LAKES ON WED TO ADD SOME SYNOPTIC LIFT TO A RAPIDLY
DEEPENING AND FAST MOVING SURFACE LOW.
PRECIP MAY START OFF EARLY WED AS A MIX OF RAIN AND SNOW IN THE
SE...BUT COOLING TEMPS ALOFT WILL CONVERT ALL PRECIP OVER TO SNOW
BY MIDDAY. AS IS A GENERAL RULE WITH THESE TYPES OF EVENTS...
THERE WILL LIKELY BE A SHARP DROPOFF IN ACCUMULATIONS ON THE NW
EDGE OF THE HEAVIER SNOWS. BIGGEST POTENTIAL IMPACTS IN OUR CWA
WILL BE THE SUSQ VALLEY...WHERE POTENTIAL FOR A SEVERAL HOUR
PERIOD OF HEAVY ACCUMULATING SNOW WILL EXIST. BUT AGAIN...SMALL
CHANGES IN THE ULTIMATE TRACK COULD LEAD TO MODIFICATIONS OF
SNOWFALL FORECASTS. THE TAKE AWAY...THOUGH THE DETAILS REMAIN
UNCERTAIN...THERE WILL BE SIG IMPACTS TO TRAVEL ALONG THE U.S.
EAST COAST ON ONE OF THE BUSIEST DAYS OF THE YEAR /WED/. PLAN
ACCORDINGLY.
COLDER AIR REMAINS IN PLACE LATE WEEK AS SCT SNOW SHOWERS RETURN
TO THE WESTERN HIGHER TERRAIN. TEMPS LOOK TO GRADUALLY MODIFY LATE
WEEKEND HEADING INTO NEXT WEEK...WITH NO BIG STORM SYSTEMS EXPECTED
AFTER THANKSGIVING.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
A LOW PRES SYSTEM TRACKING NORTHWARD INTO THE GRT LKS WILL SPREAD
LOWERING CIGS AND RAIN ACROSS CENTRAL PA TONIGHT. REGIONAL RADAR
AT 00Z SHOWS THE RAIN ABOUT TO ENTER SOUTHERN PA AND LINEAR
EXTRAPOLATION SUGGESTS THE RAIN WILL OVERSPREAD ALL CENTRAL PA
AIRFIELDS BTWN 02Z-04Z. A BLEND OF LATEST LAMP GUIDANCE...SREF AND
HRRR MDL OUTPUT IMPLY CIGS WILL DROP TO IFR BTWN 04Z-06Z...JUST A
COUPLE HOURS AFTER THE RAIN BEGINS.
SOUTHERLY WINDS IN THE 1-2 KFT LAYER WILL BECOME VERY STRONG
OVERNIGHT...MAKING LLWS A NEAR CERTAINTY. SFC GUSTS OVERNIGHT WILL
BE HIGHEST AT KJST DUE TO IT/S RIDGETOP LOCATION. HRRR OUTPUT
SUGGESTS GUSTS BTWN 25-35KTS ARE POSS THERE BTWN 03Z-07Z. MUCH
LIGHTER SFC WINDS EXPECTED ELSEWHERE...WHICH WILL LEAD TO THE
LLWS.
EARLY LOW CIGS AND LINGERING DRIZZLE WILL GIVE WAY TO IMPROVING
CONDS BY LATE MONDAY AM...AS WARM FRONT LIFTS NORTH OF THE
REGION. GENERALLY VFR CONDS ARE ANTICIPATED MON AFTN. HOWEVER...A
COLD FRONT MOVING FROM THE WEST WILL BE ACCOMPANIED BY SCT LATE
DAY SHRA ACROSS THE W MTNS...POSSIBLY PRODUCING A BRIEF VSBY
REDUCTION AT KBFD OR KJST.
OUTLOOK...
TUE...NO SIG WX EXPECTED.
WED...SNOW/LOW VSBYS POSS EASTERN PA.
THU...-SHSN/REDUCED VSBYS POSS NW MTNS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
419 AM CST SAT NOV 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CST SAT NOV 22 2014
FOG AND STRATUS SHOULD PERSIST FROM NW IA INTO PART OF SW MN
INTO THE LATE MORNING WHEN LOW LEVEL SWRLY FLOW AND SOME
WARMING WILL BE SWEEPING IT OUT. FOG WILL CONTINUE TO GET
MARGINALLY DENSE IN SOME AREAS BUT WIDESPREAD DENSE FOG HAD NOT
DEVELOPED...AND WITH A CONTINUING DECENT LOW LEVEL FLOW IN THAT AREA
SUSPECT WE WILL NOT NEED A DENSE FOG ADVISORY...BUT OF COURSE WILL
MONITOR NEXT FEW HOURS. SOME VERY PATCHY SHALLOW FOG WILL
CONTINUE TO DEVELOP FURTHER WEST BUT DRIER AIR NOT MUCH ABOVE THE
SURFACE SHOULD PREVENT MUCH. ASIDE FROM SOME STRATUS LINGERING
FAR EAST INTO PERHAPS THE EARLY AFTERNOON...THE FORECAST AREA IS
EXPECTED TO BE MOSTLY SUNNY TODAY. TEMPERATURES OF COURSE WILL BE
MILD WITH A DECENT ROUND OF SNOWMELT. UPPER 30S NORTHEAST TO THE
LOWER 50S SOUTHWEST LOOKS GOOD FOR HIGHS.
TONIGHT WE EXPECT THAT THE STRATUS WILL REDEVELOP SOUTHEAST AS
HIGHER CLOUDS BEGIN TO INCREASE FROM THE WEST WITH APPROACHING
SYSTEM. THERE SEEMS TO BE ENOUGH MID LEVEL LIFT FOR A FEW LIGHT
SHOWERS TO SPREAD IN FROM THE WEST BUT MODELS ARE SHOWING FAIRLY DRY
AND WILL CONTINUE TO PLAY THE AIR BEING DRY ENOUGH TO PRECLUDE
PRECIPITATION THIS WAY THROUGH THE NIGHTTIME HOURS. THE INCREASE IN
LOW CLOUDS AND THEIR DEPTH OVER NORTHWEST IOWA SUGGESTS SOME DRIZZLE
POSSIBLE LATE TONIGHT...BUT THAT INCREASED DEPTH ALSO SUGGESTS
DROPLETS COULD BE BIG ENOUGH FOR MINIMALLY MEASURABLE LIGHT
RAIN...AND SINCE WE HAVE BEEN CARRYING LOW POPS...WILL CONTINUE
THEM FOR LATE TONIGHT...EVEN THOUGH MID LEVEL SUPPORT FOR RAIN
SEEMS FURTHER SOUTHEAST. TEMPERATURES WILL BE MILD WITH AREAS IN
SOUTHEAST SD NORTH OF INTERSTATE 90 MAYBE COOLING A DEGREE OR TWO
BELOW FREEZING. UNSURE OF THE DEGREE OF LATE NIGHT MIXING WITH
APPROACHING SYSTEM SO WILL NOT GET CUTE WITH ANY SUDDEN TEMPERATURE
JUMPS...BUT THEY COULD HAPPEN.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 415 AM CST SAT NOV 22 2014
DOMINANT FOCUS OF THE START OF THE LONGER TERM IS EVOLUTION OF THE
STRONG SYSTEM TO THE EAST HEADING INTO SUNDAY NIGHT AND MONDAY. AS
THE NORTHERN STREAM ENERGY COMPONENT APPROACHES ON SUNDAY...AT
LEAST A MINIMAL THREAT FOR SOME EARLY DAY PRECIPITATION AS VARIOUS
DEGREE OF SHARPNESS TO TROUGH BEGINS TO SLIDE ACROSS THE DAKOTAS.
IF NOT FOR A FEW MODELS/RUNS INDICATING THE MID LEVEL FRONTAL ZONE
ACTUALLY UNDERGOING WEAKENING HEADING ACROSS THE CWA DURING THE
MORNING...WOULD JUSTIFY PERHAPS STRONGER ON THE POPS FOR THE MORNING
AND EARLY AFTERNOON. THERE IS A BIT OF CONCERN ON PRECIPITATION
TYPE POTENTIAL WITH FAIRLY WARM TEMPS ALOFT BATTLING WHAT IS
CERTAIN TO BE A FAIRLY DECENT WET BULB IMPACT. PROBABLY A MIX OF
RAIN OR SNOW...OR EVEN ALL LIGHT SNOW IF CAN GET A BIT MORE
INTENSE OR BANDED PER NAM TYPE SOLUTION. FURTHER SOUTHEAST...
AHEAD OF THE LOW LEVEL WIND SHIFT...WILL LIKELY FIND A MURKY MESS
OF LOWER CLOUDS...SOME FOG...AND CHANCE OF DRIZZLE/LIGHT RAIN IN
THE EARLY MORNING. THIS WILL GET QUICKLY SHOVED ASIDE BY SHIFT IN
WINDS TO THE NORTHWEST. INITIALLY NOT A VERY STRONG COLD PUSH...
WHICH SHOULD ALLOW TEMPS TO RETURN TO THE LOWER 40S ACROSS THE
SOUTHEAST HALF. HOWEVER...COLDER AIR WILL REALLY START TO SURGE
INTO THE AREA DURING THE AFTERNOON...WITH A 6-8C DROP IN 925 HPA
TEMPS LIMITING MIXING BY MIDDAY NORTHWEST...MID AFTERNOON CENTRAL...
AND LATE DAY SOUTHEAST CWA...AND MOST CERTAINLY ENDING WITH A MORE
THAN TYPICAL LATE DAY DROP. WINDS WILL ALSO INCREASE TO 20 TO 30
MPH BY LATE DAY OVER MUCH OF SE SD.
OVERNIGHT IS WHEN THE MERGING OF THE SOUTHERN STREAM AND NORTHERN
STREAM ENERGY OCCURS...BUT WILL BE TO THE EAST...AND IMPACT WILL
BE MAINLY TO THE WIND FIELDS ACROSS THE AREA. GFS IS FAR STRONGER
WITH CYCLOGENESIS...SOMEWHAT FURTHER EASTWARD. WHATEVER SOLUTION
IS MORE CORRECT IN THE END...OUR AREA IS SURE TO EXPERIENCE VERY
STRONG AND GUSTY WINDS FROM 25 TO 45 MPH...AND A TENDENCY FOR THE
SUNDAY NIGHT INTO MONDAY PERIOD FOR SOME LIGHTER SNOWFALL TO CYCLE
SOUTHEASTWARD ACROSS THE AREA...ESPECIALLY SW MN. APPEARS THAT
TOTALS WILL CERTAINLY BE LIGHT AS DEEPER FORCING CONTINUES TO THE
EAST...BUT COULD SEE SOME HALF INCH OR BIT MORE AMOUNTS ACROSS
SOUTHWEST MINNESOTA BY THE TIME IT ENDS ON MONDAY EVENING.
DESPITE THE WINDS...DO NOT EXPECT ENOUGH NEW SNOWFALL TO CREATE
ANY BLOWING SNOW ISSUES...AND THE OLDER SNOW WILL BE WELL CRUSTED
FROM WARMING ABOVE FREEZING FOR A COUPLE DAYS.
FOR THE CRITICAL THANKSGIVING TRAVEL TIME...BY TUESDAY AND
WEDNESDAY...THE AGREEMENT IN THE LONGER WAVE PATTERN IS THERE IN
A GENERAL SENSE...BUT THE IMPORTANT DETAILS ARE VASTLY DIFFERENT.
MOST SOLUTIONS INDICATE A FAIRLY DISTINCT CLIPPER SYSTEM MOVING
FROM NORTH DAKOTA TOWARD CENTRAL MINNESOTA...BUT GFS IS ABOUT 6-9
HOURS QUICKER THAN EC/CANADIAN. TUESDAY WILL PUT CWA INTO A WARMER
SECTOR OF WAVE...AND WILL LIKELY SEE TEMPS PUSH INTO THE 35 TO 40
DEGREE RANGE OVER THE SOUTHWEST HALF OF THE AREA. HAVE PUSHED UP
TIMING FOR A BURST OF SNOWFALL WITHIN THE WARM AIR ADVECTION ZONE
TUESDAY NIGHT... BUT WITH THE STRONGER AND DEEPER FORCING
REMAINING JUST NORTHEAST OF THE AREA...HAVE KEPT THINGS AS A
CHANCE POP FOR THE TIME. THIS IS WHERE THINGS START TO DIVERGE
SIGNIFICANTLY...WITH EC SO AMPLIFIED WITH THIS CLIPPER WAVE THAT
THE THERMAL BOUNDARY IS DRIVEN SO FAR SOUTHWARD THAT ARCTIC RIDGE
TAKES OVER AND IS SIMPLY COLD AND DRY THROUGH THE END OF THE WEEK.
THE GFS/CANADIAN ARE NOT AS AMPLIFIED...GFS LEAST SO...AND THEN
FIND APPROACH OF THE NEXT SUBTLE NORTHERN STREAM WAVE IN A
FAVORABLE LOCATION TO INTERACT WITH THERMAL RIBBON...RESULTING IN
A BAND OF LIGHT PRECIPITATION ACROSS THE AREA...EITHER MAINLY
NORTH PER 00Z GFS...OR THROUGH THE HEART PER 06Z GFS...OR THE
MISSOURI VALLEY PER CANADIAN. QPF/SNOW RATIOS OF 18-20/1 WOULD
BRING PERHAPS 1 TO 3 INCHES OF SNOWFALL IN A WORST CASE AT THIS
POINT. COULD NOT GET A REGIONAL CONSENSUS ON INTRODUCING POPS WITH
INITIALIZATION GRIDS SUB MEASURABLE FOR MOST ON WEDNESDAY INTO
WEDNESDAY EVENING...SO HAVE DEFERRED TO LATER FORECASTS IN HOPES
GUIDANCE CONVERGES ENOUGH TO SUPPORT MORE REASONABLE POPS. ARCTIC
HIGH SETTLES SOUTHWARD THROUGH THANKSGIVING TO GIVE TEMPS WELL
BELOW NORMAL ONCE AGAIN...WITH A LITTLE RECOVERY EXPECTED FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY EVENING)
ISSUED AT 1052 PM CST FRI NOV 21 2014
FORECAST CONTINUES TO REMAIN A CHALLENGE TONIGHT INTO TOMORROW.
PRETTY CONFIDENT KHON REMAINS VFR...BUT STRATUS AND FOG CONCERNS
REMAIN EAST OF THE JAMES RIVER. WATCHING LARGE AREA OF LOW STRATUS
CONTINUE TO PUSH NORTH TOWARDS THE REGION...WITH MVFR CIGS INTO
KSUX. BASED ON MODEL SOUNDINGS AND UPSTREAM OBS...THINK THEY WILL
EVENTUALLY GET CIGS BELOW 500 FEET...AND COULD POSSIBLY ALSO SEE
DENSE FOG. LESS CERTAIN ABOUT KFSD...WHICH WILL LIKELY BE NEAR THE
WEST EDGE OF ANY STRATUS AND FOG. BASED ON THE LATEST RAP AND HRRR
WILL KEEP IFR CIGS INTO KFSD LATER TONIGHT...ALTHOUGH AGAIN
CONFIDENCE IS LOW. WHAT IS ALSO UNCERTAIN IS HOW QUICKLY THE STRATUS
AND FOG EXITS TOMORROW. STAYED ON THE OPTIMISTIC SIDE FOR NOW GIVEN
LOW CONFIDENCE...BUT WOULD NOT BE SURPRISED IF LOW CIGS AND VIS
STICK AROUND LONGER THAN CURRENTLY FORECAST...AS WINDS WILL STAY OUT
OF THE SOUTH SOUTHEAST THROUGH THE DAY.
SO IN SUMMARY...AT THE LEAST THINK NORTHWEST IOWA AND PORTIONS OF
SOUTHWEST MINNESOTA WILL SEE LOW STRATUS AND POTENTIALLY DENSE FOG
TONIGHT INTO EARLY TOMORROW. THIS COULD EXTEND AS FAR WEST AS THE
INTERSTATE 29 CORRIDOR. FOR NOW HAVE IMPROVEMENTS BY MID
MORNING...BUT THE POSSIBILITY IS DEFINITELY THERE THAT THESE
CONDITIONS LINGER INTO LATE MORNING OR EVEN EARLY AFTERNOON...WITH
CONDITIONS SLOWLY IMPROVING TO VFR FROM WEST TO EAST.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...CHAPMAN
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1053 PM CST FRI NOV 21 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 400 PM CST FRI NOV 21 2014
DIFFICULT LOW CONFIDENCE FORECAST IN THE NEAR TERM. TEMPERATURES
HAVE FINALLY RISEN ABOVE FREEZING IN MOST LOCATIONS ACROSS THE AREA.
THIS HAS PROMOTED AT LEAST A LITTLE BIT OF SNOW MELT. AREA OF
STRATUS THAT HAS BEEN CONTAINED ACROSS MISSOURI AND KANSAS IS NOW
CREEPING NORTHWARD...AND COULD IMPACT PORTIONS OF NORTHWEST IOWA
MAINLY EAST OF THE TAF SITES. ON THE BACK EDGE OF THE STRATUS...
HRRR...RAP AND SREF SUGGEST FOG WILL DEVELOP AFTER 06Z. TRIED TO
KEEP MENTION OF FOG SOUTH OF THE BUFFALO RIDGE WITH STRONG WINDS
LINGERING IN ELEVATED LOCATIONS. KEPT LOWS MILD NORTH OF THE BUFFALO
RIDGE WITH DOWNSLOPE EFFECT. ACROSS THE REST OF THE AREA...SIDED
FAIRLY CLOSE TO CONSENSUS.
STRONG WARMING ALOFT IS EXPECTED THROUGHOUT THE DAY ON
SATURDAY...THE QUESTION REMAINS THOUGH AS TO HOW MUCH OF THAT
WARMING WILL SURFACE. 925 HPA TEMPS WARM THROUGHOUT THE
DAY...STARTING NEAR 3 TO 5 C AND WARMING TO 5 TO 7C BY 00Z SUNDAY.
FOG AND/OR STRATUS MAY LINGER THROUGH THE MORNING HOURS...LIMITING
THE POTENTIAL TO WARM. WHERE THERE IS A VOID OF LOW CLOUDS...SHOULD
SEE SOME NICE WARMING WITH SOUTHWEST FLOW ACROSS THE AREA. STILL
WILL BE FAR FROM FULL MIXOUT...BUT LOOKS TO BE A RELATIVELY MILD DAY
WITH TEMPERATURES ABOVE NORMAL. EXPECT SNOW PACK TO CONTINUE TO
DWINDLE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 400 PM CST FRI NOV 21 2014
CLOUDS BUILD BACK INTO THE AREA SATURDAY EVENING AND NIGHT AHEAD OF
THE NEXT STORM SYSTEM EXPECTED TO IMPACT THE REGION SUNDAY THROUGH
MONDAY EVENING. SPLIT FLOW WILL KEEP THE AREA LARGELY DRY INTO
SUNDAY AFTERNOON AS THE SOUTHERN STREAM LIFTS A TROUGH NORTHWARD
FROM THE SOUTHERN PLAINS INTO THE MID MISSISSIPPI VALLEY ON SUNDAY
WHILE A TROUGH DIGS INTO THE NORTHERN HIGH PLAINS ALONG THE NORTHERN
STREAM. WITH THE FORECAST AREA STATIONED BETWEEN THESE TWO
AREAS...DRIER CONDITIONS WILL PREVAIL UNDER SOME MID TO HIGH CLOUDS.
A LITTLE LIGHT RAIN POSSIBLY MIXED WITH SOME NORTH IN THE NORTHEAST
MAY CREEP INTO OUR FAR EASTERN BORDER DURING THE DAY. IT LOOKS LIKE
THE BEST SUPPORT FOR ANY WET WEATHER WILL REMAIN EAST OF OF THE
FORECAST AREA. WITH SOMEWHAT BREEZY SOUTHWEST WINDS AND WARMER AIR
ALOFT SATURDAY NIGHT...TEMPERATURES WILL STAY MILD OVERNIGHT WITH
LOWS IN THE 30S. SUNDAY WILL REMAIN MILD AS WINDS TURN NORTHWESTERLY
AND BECOME WINDY BY AFTERNOON. TEMPERATURES WARM INTO THE MID 30S TO
MID 40S BEFORE THE COLD AIR BEGINS LEAKING BACK INTO THE REGION
SUNDAY NIGHT INTO MONDAY.
WITH THE NORTHERN STREAM WAVE SLIDING ACROSS THE NORTHERN PLAINS
SUNDAY EVENING THROUGH MONDAY...SOME LIGHT SNOW WILL SPREAD EAST
ACROSS THE AREA. MOISTURE DOES NOT LOOK TOO IMPRESSIVE WITH THIS
WAVE...HOWEVER SOME DECENT FRONTOGENESIS AND MODEST QG FORCING
SLIDING THROUGH THE AREA WILL ALLOW FOR SOME ISOLATED TO SCATTERED
LIGHT TO FALL. MOST AREAS WILL SEE LESS THAN HALF INCH...BUT COULD
BE A LITTLE HIGHER IN PARTS OF SOUTHWEST MINNESOTA. WITH BLUSTERY
WINDS...ANY SNOW THAT DOES FALL WILL BLOW AROUND...BUT ANY EXISTING
SNOW PACK SHOULD HAVE ENOUGH OF A CRUST TO NOT CAUSE ANY BLOWING
SNOW ISSUES.
MODELS SHOWING BETTER AGREEMENT HEADING INTO THE MIDDLE OF NEXT
WEEK. LEFT A LOW CHANCE FOR LIGHT SNOW MAINLY ACROSS OUR NORTHERN
HALF ON TUESDAY NIGHT AS ANOTHER FRONT DROPS THROUGH THE REGION. DRY
AND COLD WEATHER PERSISTS WEDNESDAY AND THURSDAY...WITH HIGHS
COOLING FURTHER INTO THE MID TEENS TO MID 20S. SHARP RIDGING OVER
THE INTERMOUNTAIN WEST EASES INTO THE PLAINS AND FLATTENS OUT...BUT
TEMPERATURES LOOK MUCH MILDER ON FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY EVENING)
ISSUED AT 1052 PM CST FRI NOV 21 2014
FORECAST CONTINUES TO REMAIN A CHALLENGE TONIGHT INTO TOMORROW.
PRETTY CONFIDENT KHON REMAINS VFR...BUT STRATUS AND FOG CONCERNS
REMAIN EAST OF THE JAMES RIVER. WATCHING LARGE AREA OF LOW STRATUS
CONTINUE TO PUSH NORTH TOWARDS THE REGION...WITH MVFR CIGS INTO
KSUX. BASED ON MODEL SOUNDINGS AND UPSTREAM OBS...THINK THEY WILL
EVENTUALLY GET CIGS BELOW 500 FEET...AND COULD POSSIBLY ALSO SEE
DENSE FOG. LESS CERTAIN ABOUT KFSD...WHICH WILL LIKELY BE NEAR THE
WEST EDGE OF ANY STRATUS AND FOG. BASED ON THE LATEST RAP AND HRRR
WILL KEEP IFR CIGS INTO KFSD LATER TONIGHT...ALTHOUGH AGAIN
CONFIDENCE IS LOW. WHAT IS ALSO UNCERTAIN IS HOW QUICKLY THE STRATUS
AND FOG EXITS TOMORROW. STAYED ON THE OPTIMISTIC SIDE FOR NOW GIVEN
LOW CONFIDENCE...BUT WOULD NOT BE SURPRISED IF LOW CIGS AND VIS
STICK AROUND LONGER THAN CURRENTLY FORECAST...AS WINDS WILL STAY OUT
OF THE SOUTH SOUTHEAST THROUGH THE DAY.
SO IN SUMMARY...AT THE LEAST THINK NORTHWEST IOWA AND PORTIONS OF
SOUTHWEST MINNESOTA WILL SEE LOW STRATUS AND POTENTIALLY DENSE FOG
TONIGHT INTO EARLY TOMORROW. THIS COULD EXTEND AS FAR WEST AS THE
INTERSTATE 29 CORRIDOR. FOR NOW HAVE IMPROVEMENTS BY MID
MORNING...BUT THE POSSIBILITY IS DEFINITELY THERE THAT THESE
CONDITIONS LINGER INTO LATE MORNING OR EVEN EARLY AFTERNOON...WITH
CONDITIONS SLOWLY IMPROVING TO VFR FROM WEST TO EAST.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
734 PM CST SUN NOV 23 2014
.DISCUSSION...
STRONG VORT AXIS MOVING THROUGH THE MID STATE AT THIS TIME WITH
WIDESPREAD SHOWER ACTIVITY. NOT MUCH IN THE WAY OF PRECIP COVERAGE
BACK TO OUR SOUTHWEST. HRRR SHOWS THAT PRECIP COVERAGE WILL
DECREASE MARKEDLY FROM SW TO NE OVER THE NEXT FEW HOURS.
HOWEVER...ADDITIONAL LIGHT SHOWER ACTIVITY WILL RETURN AFTER
OR JUST BEFORE MIDNIGHT. THEREFORE...CURRENT FCST LOOKS TO BE IN
GOOD SHAPE AS THE POPS WILL DROP DOWN INTO THE CHANCE CATEGORY AFT
MIDNIGHT.
AS FOR THE WIND ADVISORY...GRADIENT STILL LOOKS AS THOUGH IT WILL
BECOME TIGHTER TOWARD 12Z WHEN THE FRONT ROLLS THROUGH. CURRENT
SFC ANALYSIS SHOWS THAT PEAK WINDS ARE GENERALLY IN THE 25 TO 35
MPH RANGE.
SO BASICALLY...NO CHANGES AT THIS TIME TO THE FCST. WILL LIKELY
SEND OUT ANOTHER SET OF ZONES AND LOWER POPS TOWARD THE SOUTHWEST
ONCE THIS CURRENT BATCH OF SHOWERS LIFTS TO THE NORTHEAST.
WINDS MAY ACTUALLY BECOME A LITTLE STRONGER ONCE THE PRECIP FREE
AREA MOVES IN. TEMPS STILL LOOK TO BE IN GOOD SHAPE.
WILL ISSUE THE UPDATE A LITTLE LATER THIS EVENING AND BEGIN TO
LOWER POPS...SOME...ACROSS THE AREA.
&&
.PREV DISCUSSION... /ISSUED 609 PM CST SUN NOV 23 2014/
AVIATION 00Z DISCUSSION...
STORM SYSTEM TO PULL EAST OVERNIGHT. WE WILL STILL SEE SOME
RESIDUAL SHOWER ACTIVITY THROUGH THE EVENING HOURS BEFORE THE
PRECIP DECREASES IN COVERAGE AND INTENSITY. OTW...PRESSURE
GRADIENT WILL TIGHTEN OVERNIGHT AND WINDS WILL REMAIN BREEZY AND
GUSTY AT TIMES.
AS FOR CIGS...LOW LEVEL CLOUDINESS WILL PERSIST BUT CIGS WILL
LIFT SOME TOWARD THE END OF THE TAF PD.
PREV DISCUSSION... /ISSUED 340 PM CST SUN NOV 23 2014/
DISCUSSION...IT HAS BEEN A RAINY AND INCREASINGLY BREEZY DAY
ACROSS MID TN. AFTERNOON TEMPERATURES WERE IN THE MID TO UPPER
50S. THE MAIN RAIN SHIELD IS LIFTING ACROSS MID TN...AND SOME
BREAKS IN THE RAIN ARE MOVING INTO THE SW COUNTIES. THESE BREAKS
IN TE RAIN WILL SPREAD ACROSS MID TN OVER THE NEXT COUPLE OF
HOURS...BUT WE WILL KEEP HIGH POPS THROUGH THE EVENING AS RADAR
SHOWS MORE SHOWERS MOVING UP FROM THE SOUTHWEST. THE POPS WILL
DROP OFF MORE SIGNIFICANTLY LATE TONIGHT. NO THUNDERSTORMS HAVE
BEEN OBSERVED TODAY...BUT A LIGHTNING STRIKE OR 2 COULD OCCUR
EARLY THIS EVENING.
THE MAIN CONCERN FOR THIS EVENING THROUGH TONIGHT IS THE WIND
POTENTIAL. A VORT MAX AND SMALL SCALE SURFACE LOW PRESSURE CENTER
FROM WEST CENTRAL MS WILL ZIP UP THE MS RIVER LATE THIS AFTERNOON
AND EVENING...MEETING UP WITH A DEEPENING SYNOPTIC SCALE LOW
PRESSURE FROM OK. A LLJ WILL STRENGTHEN TO 50-60KT. SURFACE WIND
GUSTS WILL REACH OVER 40 MPH AT TIMES. THE MAIN TIME FOR THIS
WILL BE FROM 5 PM TO 10 PM...AND THESE STRONGER GUSTS WILL AFFECT
LOCATIONS MAINLY ALONG AND WEST OF I 65. WE HAVE ALREADY ISSUED A
WIND ADVISORY FOR THE MID STATE WEST OF THE PLATEAU.
FOR LATER TONIGHT THROUGH MONDAY...THE CONSOLIDATED LOW PRESSURE
SYSTEM WILL ACCELERATE ACROSS THE GREAT LAKES REGION AND INTO
EASTERN CANADA. EVEN THROUGH THE LOW WILL BE MOVING AWAY...IT WILL
STRENGTHEN...RESULTING IN STRONG WINDS ACROSS A WIDE AREA. FOR MID
TN...THIS MEANS THAT WINDS WILL INCREASE AGAIN TOWARD
DAYBREAK...WITH SPEEDS OF 20-30 MPH AND SOME 45 MPH THROUGH MONDAY
MORNING. GUSTS OF THAT STRENGTH COULD EASILY BRING DOWN SOME LIMBS
AND WEAKER TREES...AND CAUSE SCATTERED POWER OUTAGES. THERE WILL
CONTINUE TO BE A CHANCE FOR SCATTERED SHOWERS INTO MONDAY
MORNING...THEN DRIER AIR IS EXPECTED MONDAY AFTERNOON. WIND GUSTS
WILL TAPER OFF SLIGHTLY MONDAY AFTERNOON...BUT STILL FREQUENTLY
OVER 30 MPH UNDER PARTLY SUNNY SKIES.
DRY AND COOLER WX MOVES IN FOR MONDAY NIGHT...AND WILL STAY
THROUGH THE REST OF THE WEEK. THERE ARE A COUPLE OF MIDWEEK
SYSTEMS THAT NEED TO BE WATCHED FOR SOME SHOWER POTENTIAL.
MODELS HAVE BEEN VERY INCONSISTENT WITH THESE FEATURES...BUT IT
LOOKS LIKE THEY WILL NOT HAVE MUCH IMPACT ON MID TN. SO...AFTER A
VERY ACTIVE BEGINNING OF THIS WEEK...QUIET CONDITIONS ARE EXPECTED
FOR THE THANKSGIVING HOLIDAY WITH GENERALLY COOLER THAN NORMAL
TEMPS.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 53 57 34 50 / 80 20 0 0
CLARKSVILLE 51 55 32 45 / 80 20 0 0
CROSSVILLE 53 57 31 47 / 70 30 05 05
COLUMBIA 54 58 33 51 / 60 20 0 0
LAWRENCEBURG 52 57 32 51 / 50 20 0 0
WAVERLY 50 56 32 47 / 60 20 0 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST MONDAY FOR TNZ005>011-023>033-
056>064-075-077-093>095.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1149 AM CST SAT NOV 22 2014
.UPDATE...
18Z TAF DISCUSSION.
&&
.AVIATION...
VFR CONDITIONS EXPECTED TODAY WITH SCT STRATOCU AND BRISK SOUTH
WINDS WITH GUSTS TO AROUND 20 KTS IN AFTERNOON. CIGS BECOME MVFR
BY 23/10Z AND IFR BY 23/15Z AS STRONG MOISTURE ADVECTION
COMMENCES DUE TO POWERFUL SURFACE LOW TAKING SHAPE TO OUR WEST.
-SHRA NOT ANTICIPATED UNTIL AROUND 15Z AT ALL AIRPORTS...WITH
STRONG SE WINDS WITH GUSTS UP TO 30 KTS DEVELOPING BY END OF TAF
PERIOD.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 933 AM CST SAT NOV 22 2014/
UPDATE...
LATEST RADAR IMAGERY SHOWS A FEW LIGHT RAIN SHOWERS AND SPRINKLES
CONTINUE ACROSS NORTHWEST PARTS OF THE MID STATE. HRRR INDICATES
THIS ACTIVITY WILL CONTINUE THROUGH AROUND 18Z...SO EXPANDED
SLIGHT CHANCE POPS A BIT EASTWARD AND EXTENDED THROUGH THAT TIME.
PRECIP SHOULD MOVE OUT BY AFTERNOON WITH PARTLY CLOUDY SKIES AND
MUCH WARMER TEMPERATURES WITH HIGHS IN THE LOWER 60S. REST OF
FORECAST LOOKS GOOD AND ONLY MINOR TWEAKS WERE MADE.
SHAMBURGER
PREV DISCUSSION... /ISSUED 537 AM CST SAT NOV 22 2014/
UPDATE...FOR 12Z AVIATION FORECASTS.
AVIATION...
A FEW MORNING SPRINKLES IN NORTHWEST COUNTIES/CKV...OTHERWISE NO
PRECIPITATION TODAY. EXTENSIVE MID AND HIGH CLOUDS WILL CONTINUE
STREAMING ACROSS MIDDLE TN AHEAD OF A UPPER LEVEL STORM SYSTEM
THAT WILL APPROACH LATE TONIGHT AND SUNDAY. SFC WINDS WILL PICK UP
A LITTLE TODAY AS GRADIENTS TIGHTEN.
INCREASING MOISTURE WILL HELP DEVELOP LOW CLOUDS AFTER 00Z TONIGHT.
MVFR CIGS POSSIBLE AT BNA AND CKV TOWARD 12Z SUNDAY. HIGH CHANCE OF
RAIN AND MVFR/IFR CIGS SHORTLY AFTER THIS FORECAST CYCLE ENDS AT
12Z SUNDAY.
PREV DISCUSSION... /ISSUED 416 AM CST SAT NOV 22 2014/
DISCUSSION...
THE SURFACE RIDGE THAT HAS KEPT US DRY ACROSS THE MID-STATE THE LAST
COUPLE OF DAYS HAS MOVED OFF TO THE EAST. NOW SITTING OVER THE
MID-ATLANTIC STATES...IT HAS PUT THE SOUTHEAST U.S. INTO A
SOUTHEASTERLY BOUNDARY LAYER FLOW. COUPLED WITH A WEAK MID-LEVEL
DISTURBANCE MOVING ENE THROUGH THE MID-MISSISSIPPI/TN/OHIO
VALLEYS...THERE ARE A FEW SHOWERS ON THE RADAR. THE CATCH IS...IT`S
BEEN SO DRY AND THE ATMOSPHERE IS TAKING SO LONG TO SATURATE THAT
NOT MUCH OF THIS RAIN IS REACHING THE GROUND. KCKV SHOWED LIGHT
RAIN A COUPLE OF HOURS AGO...BUT THEY ONLY MEASURED A TRACE. THESE
RADAR REFLECTIVITIES SHOULD MOVE OFF TO THE NE THROUGH THE MORNING
HOURS...LEAVING PARTLY TO MOSTLY CLOUDY CONDITIONS ACROSS THE
STATE. THE MOST INTERESTING PART OF THE DAY WILL BE THE WINDS AS
THE PRESSURE GRADIENT TIGHTENS ACROSS MIDDLE TN. IT WILL BE BREEZY
AND MOST EVERYONE WILL WARM INTO THE 60S TODAY WITH MIDDLE TO UPPER
50S ON THE PLATEAU.
ALREADY IN ITS BEGINNING STAGES...AN INTENSE SHORTWAVE TROUGH IS
EXPECTED TO DEVELOP OVER THE DESERT SOUTHWEST TODAY. THIS SYSTEM
WILL BE OUR WEATHER MAKER ON SUNDAY. IN RESPONSE TO THIS SYSTEM
ROUNDING THE BASE OF THE LONGWAVE PATTERN...A SURFACE LOW WILL
DEVELOP OVER E TEXAS TONIGHT...MOVING NEWD...AND PASSING JUST TO THE
WEST OF US. UNFORTUNATELY...THIS PUTS US IN A PRECARIOUS POSITION.
THE UPPER LEVEL TROUGH SWINGS INTO A NEGATIVE TILT SUNDAY MORNING
AND BECAUSE OF THIS...THE SURFACE LOW DEEPENS PRETTY RAPIDLY. THIS
WILL RESULT IN A COUPLE OF THINGS...FIRST...IT WILL BE WINDY
SUNDAY. WHILE TODAY`S BREEZY CONDITIONS WILL RELAX A BIT TONIGHT...
THE SURFACE PRESSURE GRADIENT TIGHTENS BACK UP SIGNIFICANTLY AND WE
COULD SEE SUSTAINED WINDS OF 15-25 MPH WITH GUSTS TO 35 OR 40 MPH
ON SUNDAY. THIS WILL PUT US ON THE BRINK OF A WIND ADVISORY...
BUT THIS LIKELY WON`T BE ISSUED UNTIL LATER TODAY OR EVEN TONIGHT.
A SECOND RESULT OF THE QUICK INTENSIFICATION OF THIS SYSTEM IS THE
AMOUNT OF WIND SHEAR THAT WILL ENSUE. DEEP LAYER SHEAR OF 50-70
KTS IS LIKELY AND 0-3KM SRH VALUES OF 800-1000 M^2/S^2 MAY ALSO
OCCUR. THIS AMOUNT OF WIND SHEAR MIGHT ACTUALLY BE OUR SAVING
GRACE. BECAUSE OF THE SOUTHEAST BOUNDARY LAYER FLOW OVER THE NEXT
24-36 HOURS...RETURN MOISTURE SHOULD BE FAIRLY MODERATE AHEAD OF
THIS SYSTEM THIS FAR NORTH. IN FACT...THE 60 DEGREE DEW POINT LINE
SHOULD REMAIN SOUTH OF US. WITH SO MUCH WIND SHEAR AND RELATIVELY
LITTLE INSTABILITY...WE SHOULD REMAIN NORTH OF ANY WIDESPREAD
SEVERE WEATHER THREAT. WHAT WILL BE OF CONCERN IS THE 850MB JET
THAT IS PROGGED TO DEVELOP SUNDAY MORNING THAT COULD BE AS STRONG
AS 50 TO 75 KTS. THIS MEANS WE CAN`T RULE OUT THE POTENTIAL FOR AN
ISOLATED STRAIGHT LINE WIND THREAT WITH ANY THUNDERSTORMS THAT
DEVELOP. I WILL GO AHEAD AND HIGHLIGHT THIS ISOLATED WIND THREAT
IN THE HAZARDOUS WEATHER OUTLOOK THIS MORNING FOR SUNDAY...BUT
THIS SHOULD NOT BE A WIDESPREAD SEVERE WEATHER EVENT.
FROPA WILL BE A LITTLE DELAYED WITH THIS SYSTEM...OCCURRING THROUGH
THE MORNING HOURS ON MONDAY. SOME LIGHT RAIN MAY RESULT...BUT THE
BULK OF THE ACTIVITY SHOULD BE ON SUNDAY.
BELOW NORMAL TEMPERATURES WILL RETURN FOR THE REMAINDER OF THE
WEEK. DAYTIME HIGHS IN THE 40S ARE EXPECTED BY TUESDAY...WITH
OVERNIGHT LOWS IN THE 20S AND 30S...BUT WE SHOULD REMAIN DRY
THROUGHOUT THE WEEK.
UNGER
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
933 AM CST SAT NOV 22 2014
.UPDATE...
LATEST RADAR IMAGERY SHOWS A FEW LIGHT RAIN SHOWERS AND SPRINKLES
CONTINUE ACROSS NORTHWEST PARTS OF THE MID STATE. HRRR INDICATES
THIS ACTIVITY WILL CONTINUE THROUGH AROUND 18Z...SO EXPANDED
SLIGHT CHANCE POPS A BIT EASTWARD AND EXTENDED THROUGH THAT TIME.
PRECIP SHOULD MOVE OUT BY AFTERNOON WITH PARTLY CLOUDY SKIES AND
MUCH WARMER TEMPERATURES WITH HIGHS IN THE LOWER 60S. REST OF
FORECAST LOOKS GOOD AND ONLY MINOR TWEAKS WERE MADE.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 537 AM CST SAT NOV 22 2014/
UPDATE...FOR 12Z AVIATION FORECASTS.
AVIATION...
A FEW MORNING SPRINKLES IN NORTHWEST COUNTIES/CKV...OTHERWISE NO
PRECIPITATION TODAY. EXTENSIVE MID AND HIGH CLOUDS WILL CONTINUE
STREAMING ACROSS MIDDLE TN AHEAD OF A UPPER LEVEL STORM SYSTEM
THAT WILL APPROACH LATE TONIGHT AND SUNDAY. SFC WINDS WILL PICK UP
A LITTLE TODAY AS GRADIENTS TIGHTEN.
INCREASING MOISTURE WILL HELP DEVELOP LOW CLOUDS AFTER 00Z TONIGHT.
MVFR CIGS POSSIBLE AT BNA AND CKV TOWARD 12Z SUNDAY. HIGH CHANCE OF
RAIN AND MVFR/IFR CIGS SHORTLY AFTER THIS FORECAST CYCLE ENDS AT
12Z SUNDAY.
PREV DISCUSSION... /ISSUED 416 AM CST SAT NOV 22 2014/
DISCUSSION...
THE SURFACE RIDGE THAT HAS KEPT US DRY ACROSS THE MID-STATE THE LAST
COUPLE OF DAYS HAS MOVED OFF TO THE EAST. NOW SITTING OVER THE
MID-ATLANTIC STATES...IT HAS PUT THE SOUTHEAST U.S. INTO A
SOUTHEASTERLY BOUNDARY LAYER FLOW. COUPLED WITH A WEAK MID-LEVEL
DISTURBANCE MOVING ENE THROUGH THE MID-MISSISSIPPI/TN/OHIO
VALLEYS...THERE ARE A FEW SHOWERS ON THE RADAR. THE CATCH IS...IT`S
BEEN SO DRY AND THE ATMOSPHERE IS TAKING SO LONG TO SATURATE THAT
NOT MUCH OF THIS RAIN IS REACHING THE GROUND. KCKV SHOWED LIGHT
RAIN A COUPLE OF HOURS AGO...BUT THEY ONLY MEASURED A TRACE. THESE
RADAR REFLECTIVITIES SHOULD MOVE OFF TO THE NE THROUGH THE MORNING
HOURS...LEAVING PARTLY TO MOSTLY CLOUDY CONDITIONS ACROSS THE
STATE. THE MOST INTERESTING PART OF THE DAY WILL BE THE WINDS AS
THE PRESSURE GRADIENT TIGHTENS ACROSS MIDDLE TN. IT WILL BE BREEZY
AND MOST EVERYONE WILL WARM INTO THE 60S TODAY WITH MIDDLE TO UPPER
50S ON THE PLATEAU.
ALREADY IN ITS BEGINNING STAGES...AN INTENSE SHORTWAVE TROUGH IS
EXPECTED TO DEVELOP OVER THE DESERT SOUTHWEST TODAY. THIS SYSTEM
WILL BE OUR WEATHER MAKER ON SUNDAY. IN RESPONSE TO THIS SYSTEM
ROUNDING THE BASE OF THE LONGWAVE PATTERN...A SURFACE LOW WILL
DEVELOP OVER E TEXAS TONIGHT...MOVING NEWD...AND PASSING JUST TO THE
WEST OF US. UNFORTUNATELY...THIS PUTS US IN A PRECARIOUS POSITION.
THE UPPER LEVEL TROUGH SWINGS INTO A NEGATIVE TILT SUNDAY MORNING
AND BECAUSE OF THIS...THE SURFACE LOW DEEPENS PRETTY RAPIDLY. THIS
WILL RESULT IN A COUPLE OF THINGS...FIRST...IT WILL BE WINDY
SUNDAY. WHILE TODAY`S BREEZY CONDITIONS WILL RELAX A BIT TONIGHT...
THE SURFACE PRESSURE GRADIENT TIGHTENS BACK UP SIGNIFICANTLY AND WE
COULD SEE SUSTAINED WINDS OF 15-25 MPH WITH GUSTS TO 35 OR 40 MPH
ON SUNDAY. THIS WILL PUT US ON THE BRINK OF A WIND ADVISORY...
BUT THIS LIKELY WON`T BE ISSUED UNTIL LATER TODAY OR EVEN TONIGHT.
A SECOND RESULT OF THE QUICK INTENSIFICATION OF THIS SYSTEM IS THE
AMOUNT OF WIND SHEAR THAT WILL ENSUE. DEEP LAYER SHEAR OF 50-70
KTS IS LIKELY AND 0-3KM SRH VALUES OF 800-1000 M^2/S^2 MAY ALSO
OCCUR. THIS AMOUNT OF WIND SHEAR MIGHT ACTUALLY BE OUR SAVING
GRACE. BECAUSE OF THE SOUTHEAST BOUNDARY LAYER FLOW OVER THE NEXT
24-36 HOURS...RETURN MOISTURE SHOULD BE FAIRLY MODERATE AHEAD OF
THIS SYSTEM THIS FAR NORTH. IN FACT...THE 60 DEGREE DEW POINT LINE
SHOULD REMAIN SOUTH OF US. WITH SO MUCH WIND SHEAR AND RELATIVELY
LITTLE INSTABILITY...WE SHOULD REMAIN NORTH OF ANY WIDESPREAD
SEVERE WEATHER THREAT. WHAT WILL BE OF CONCERN IS THE 850MB JET
THAT IS PROGGED TO DEVELOP SUNDAY MORNING THAT COULD BE AS STRONG
AS 50 TO 75 KTS. THIS MEANS WE CAN`T RULE OUT THE POTENTIAL FOR AN
ISOLATED STRAIGHT LINE WIND THREAT WITH ANY THUNDERSTORMS THAT
DEVELOP. I WILL GO AHEAD AND HIGHLIGHT THIS ISOLATED WIND THREAT
IN THE HAZARDOUS WEATHER OUTLOOK THIS MORNING FOR SUNDAY...BUT
THIS SHOULD NOT BE A WIDESPREAD SEVERE WEATHER EVENT.
FROPA WILL BE A LITTLE DELAYED WITH THIS SYSTEM...OCCURRING THROUGH
THE MORNING HOURS ON MONDAY. SOME LIGHT RAIN MAY RESULT...BUT THE
BULK OF THE ACTIVITY SHOULD BE ON SUNDAY.
BELOW NORMAL TEMPERATURES WILL RETURN FOR THE REMAINDER OF THE
WEEK. DAYTIME HIGHS IN THE 40S ARE EXPECTED BY TUESDAY...WITH
OVERNIGHT LOWS IN THE 20S AND 30S...BUT WE SHOULD REMAIN DRY
THROUGHOUT THE WEEK.
UNGER
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION...CORRECTED
NWS AUSTIN/SAN ANTONIO TX
349 PM CST SAT NOV 22 2014
...THE RISK OF SEVERE WEATHER AND HEAVY RAIN CONTINUES
THROUGH THIS EVENING...
.SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
STRONG STORMS AND HEAVY RAIN WILL CONTINUE TO AFFECT MAINLY THE
EASTERN HALF OF SOUTH CENTRAL TEXAS FOR THE NEXT SEVERAL HOURS.
THE THREAT FOR STRONG TO SEVERE WEATHER STILL EXISTS THROUGH THIS
EVENING. A SECOND ROUND OF SHOWERS AND STORMS CURRENTLY ONGOING
ACROSS THE SERRANIAS DEL BURRO (NORTHEAST MEXICO) IS FORECAST TO
PUSH EASTWARD AND ACROSS MOST OF SOUTH CENTRAL TEXAS THIS EVENING.
THE HRRR AND TECH-TECH HIRES MODELS DEVELOP AN MCS AROUND 23Z/5 PM
THIS AFTERNOON WHILE A LINE OF SHOWERS AND STORMS FORM AHEAD OF A
SURFACE CONVERGENCE ZONE (WARM SECTOR). IF THIS SCENARIO PANS
OUT...STRONG TO SEVERE STORMS ARE POSSIBLE ACROSS THE RIO
GRANDE...ESPECIALLY ALONG AND WEST OF ROCKSPRINGS TO HONDO TO
PEARSALL LINE. A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH 10
PM TONIGHT FOR THE AREA ABOVE MENTIONED. MAIN WEATHER THREATS WILL
BE LARGE HAIL AND DAMAGING WINDS. CAN`T RULE OUT AN ISOLATED
TORNADO OR TWO. SOME OF THESE STRONG STORMS WILL PRODUCE HEAVY
DOWNSPOURS WITH RAINFALL ACCUMULATIONS UP TO ONE INCH PER HOUR.
THE MCS IS FORECAST TO COMBINE WITH THE SHOWERS AND STORMS
EXPECTED TO FORM ALONG THE CONVERGENCE ZONE AND MOVE EAST IN A
LINEAR FASHION...AFFECTING THE I-35 CORRIDOR AROUND 8 OR 9 PM THIS
EVENING. BY 9 PM...THE SYSTEM IS LIKELY TO TRANSITION TO A HEAVY
RAIN PRODUCER WITH STRONGER STORMS CAPABLE OF PRODUCING LARGE
HAIL. THE LINE OF STORMS WILL QUICKLY PUSH TO THE EAST BY MIDNIGHT
TONIGHT WITH RAIN CHANCES COMING TO AN END ACROSS THE ENTIRE AREA
BY 2 OR 3 AM SUNDAY. NEW RAINFALL AMOUNTS FOR THE TONIGHT PERIOD
COULD RANGE FROM 1 TO 2 INCHES AND UP TO 3 INCHES IN ISOLATED
PLACES.
ON SUNDAY...EXPECT MOSTLY SUNNY/CLEAR SKIES ACROSS SOUTH CENTRAL
TEXAS WITH BREEZY CONDITIONS. A PACIFIC COLD FRONT WILL PUSH
ACROSS THE REGION SUNDAY NIGHT INTO MONDAY.
&&
.LONG TERM (MONDAY THROUGH SATURDAY)...
THE WEATHER IS EXPECTED TO BE FAIRLY QUIET FOR MUCH OF NEXT WEEK. A
WEAK FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT
IS IN RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS.
THE WEATHER FOR THANKSGIVING SHOULD BE PRETTY SEASONAL WITH HIGHS
IN THE 60S AND LOWS IN THE 30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 55 78 45 64 40 / 60 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 54 77 43 64 37 / 70 0 - - -
NEW BRAUNFELS MUNI AIRPORT 55 79 45 66 40 / 60 0 - - -
BURNET MUNI AIRPORT 52 75 42 62 38 / 50 0 - - -
DEL RIO INTL AIRPORT 50 78 46 65 38 / 20 0 - - -
GEORGETOWN MUNI AIRPORT 54 75 43 62 38 / 60 0 - - -
HONDO MUNI AIRPORT 49 77 42 65 37 / 50 0 - - -
SAN MARCOS MUNI AIRPORT 53 78 44 65 39 / 70 0 - - -
LA GRANGE - FAYETTE REGIONAL 57 78 46 64 40 / 90 0 - - -
SAN ANTONIO INTL AIRPORT 54 78 46 66 41 / 50 0 - - -
STINSON MUNI AIRPORT 54 79 46 66 41 / 60 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...17
PUBLIC SERVICE/DATA COLLECTION...00
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
339 PM CST SAT NOV 22 2014
...THE RISK OF SEVERE WEATHER AND HEAVY RAIN CONTINUES
THROUGH THIS EVENING...
.SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
STRONG STORMS AND HEAVY RAIN WILL CONTINUE TO AFFECT MAINLY THE
EASTERN HALF OF SOUTH CENTRAL TEXAS FOR THE NEXT SEVERAL HOURS.
THE THREAT FOR STRONG TO SEVERE WEATHER STILL EXISTS THROUGH THIS
EVENING. A SECOND ROUND OF SHOWERS AND STORMS CURRENTLY ONGOING
ACROSS THE SERRANIAS DEL BURRO (NORTHEAST MEXICO) IS FORECAST TO
PUSH EASTWARD AND ACROSS MOST OF SOUTH CENTRAL TEXAS THIS EVENING.
THE HRRR AND TECH-TECH HIRES MODELS DEVELOP AN MCS AROUND 23Z/5 PM
THIS AFTERNOON WHILE A LINE OF SHOWERS AND STORMS FORM AHEAD OF A
SURFACE CONVERGENCE ZONE (WARM SECTOR). IF THIS SCENARIO PANS
OUT...STRONG TO SEVERE STORMS ARE POSSIBLE ACROSS THE RIO
GRANDE...ESPECIALLY ALONG AND WEST OF ROCKSPRINGS TO HONDO TO
PEARSALL LINE. A SEVERE THUNDERSTORM WARNING IS IN EFFECT THROUGH
10 PM TONIGHT FOR THE AREA ABOVE MENTIONED. MAIN WEATHER THREATS
WILL BE LARGE HAIL AND DAMAGING WINDS. CAN`T RULE OUT AN ISOLATED
TORNADO OR TWO. SOME OF THESE STRONG STORMS WILL PRODUCE HEAVY
DOWNSPOURS WITH RAINFALL ACCUMULATIONS UP TO ONE INCH PER HOUR.
THE MCS IS FORECAST TO COMBINE WITH THE SHOWERS AND STORMS
EXPECTED TO FORM ALONG THE CONVERGENCE ZONE AND MOVE EAST IN A
LINEAR FASHION...AFFECTING THE I-35 CORRIDOR AROUND 8 OR 9 PM THIS
EVENING. BY 9 PM...THE SYSTEM IS LIKELY TO TRANSITION TO A HEAVY
RAIN PRODUCER WITH STRONGER STORMS CAPABLE OF PRODUCING LARGE HAIL.
THE LINE OF STORMS WILL QUICKLY PUSH TO THE EAST BY MIDNIGHT
TONIGHT WITH RAIN CHANCES COMING TO AN END ACROSS THE ENTIRE AREA
BY 2 OR 3 AM SUNDAY. NEW RAINFALL AMOUNTS FOR THE TONIGHT PERIOD
COULD RANGE FROM 1 TO 2 INCHES AND UP TO 3 INCHES IN ISOLATED PLACES.
ON SUNDAY...EXPECT MOSTLY SUNNY/CLEAR SKIES ACROSS SOUTH CENTRAL
TEXAS WITH BREEZY CONDITIONS. A PACIFIC COLD FRONT WILL PUSH
ACROSS THE REGION SUNDAY NIGHT INTO MONDAY.
&&
.LONG TERM (MONDAY THROUGH SATURDAY)...
THE WEATHER IS EXPECTED TO BE FAIRLY QUIET FOR MUCH OF NEXT WEEK. A
WEAK FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT
IS IN RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS.
THE WEATHER FOR THANKSGIVING SHOULD BE PRETTY SEASONAL WITH HIGHS
IN THE 60S AND LOWS IN THE 30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 55 78 45 64 40 / 60 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 54 77 43 64 37 / 70 0 - - -
NEW BRAUNFELS MUNI AIRPORT 55 79 45 66 40 / 60 0 - - -
BURNET MUNI AIRPORT 52 75 42 62 38 / 50 0 - - -
DEL RIO INTL AIRPORT 50 78 46 65 38 / 20 0 - - -
GEORGETOWN MUNI AIRPORT 54 75 43 62 38 / 60 0 - - -
HONDO MUNI AIRPORT 49 77 42 65 37 / 50 0 - - -
SAN MARCOS MUNI AIRPORT 53 78 44 65 39 / 70 0 - - -
LA GRANGE - FAYETTE REGIONAL 57 78 46 64 40 / 90 0 - - -
SAN ANTONIO INTL AIRPORT 54 78 46 66 41 / 50 0 - - -
STINSON MUNI AIRPORT 54 79 46 66 41 / 60 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...17
PUBLIC SERVICE/DATA COLLECTION...00
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1223 PM CST SAT NOV 22 2014
.UPDATE...
PLEASE SEE THE 18Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ONGOING ACROSS
MUCH OF SOUTH CENTRAL TEXAS EARLY THIS AFTERNOON. THE MOST
CONCENTRATED ACTIVITY WILL BE ALONG AND EAST OF I-35 AND WE/LL
CONTINUE TO MENTION VCTS AND TEMPO TSRA THROUGH THE EARLY EVENING
HOURS. FARTHER WEST AT KDRT...THE BETTER CHANCE FOR TSRA WILL
LIKELY ARRIVE LATE AFTERNOON/EARLY EVENING. SHOWERS AND STORMS MAY
PERSIST ALONG THE I-35 CORRIDOR UNTIL MIDNIGHT...THEN CLEAR AS A
PACIFIC COLD FRONT MOVES THROUGH.
&&
.PREV DISCUSSION... /ISSUED 1052 AM CST SAT NOV 22 2014/
UPDATE...
A SLIGHT RISK OF STRONG TO SEVERE WEATHER CONTINUES ACROSS ALL OF
SOUTH CENTRAL TEXAS FOR THE REST OF TODAY INTO THE EVENING HOURS.
A POTENT UPPER LEVEL STORM SYSTEM LOCATED ACROSS NORTHEAST MEXICO
IS FORECAST TO PUSH EAST AND OVER CENTRAL TEXAS THIS AFTERNOON AND EVENING.
BEST LIFT/UPPER DYNAMIC IS TO THE SOUTHEAST OF THE SHEAR AXIS AND
ABOUT TO CROSS THE SERRANIAS DEL BURRIO MOUNTAINS(NORTHEAST
MEXICO). THIS AREA OF BEST UPPER FORCING WILL MOVE ACROSS THE RIO
GRANDE WITHIN THE NEXT FEW HOURS. LATEST SATELLITE IMAGES ARE
SHOWING SOME BREAKS IN THE CLOUDS OVER THE SOUTHWESTERN COUNTIES AND
THIS COULD ENHANCE STORMS DEVELOPMENT AND SEVERITY. FOR THE
EASTERN PART OF SOUTH CENTRAL TEXAS...CLOUDS ARE EXPECTED TO REMAIN
WITH NO BREAKS ANTICIPATED. THE MAIN WEATHER THREAT FOR ALL OF
SOUTH CENTRAL TEXAS TODAY....STILL LARGE HAIL AND DAMIGING GUST WINDS.
CAN`T RULE OUT AND ISOLATED TORNADO OR TWO MAINLY ACROSS THE
SOUTHWEST AND FAR SOUTHEASTERN COUNTIES. HOWEVER...LATEST HIRES MODELS
AND AREA FORECAST SOUNDINGS ARE INDICATING PWATS OF 1.37 TO 1.48
INCHES. THESE NUMBERS ARE ABOVE THE 2 STANDARD DEVIATIONS FOR THIS
TIME OF THE YEAR. THEREFORE...THE POTENTIAL FOR HEAVY RAIN IS
LIKELY OVER SOME AREAS MAINLY ALONG AND EAST OF A MOUNTAIN HOME TO
CASTROVILLE TO CAMPBELLTON LINE. AS OF NOW...ISOLATED RAIN RATES
OF 2 TO 4 INCHES PER HOURS ARE BEING DETECTED BY EWX RADAR OVER
GILLESPIE AND BLANCO COUNTIES. THIS TREND WILL CONTINUE THROUGH
THE AFTERNOON HOURS AS THE UPPER LEVEL STORM SYSTEM PUSHES TO THE
EAST. EXPECT LOCALIZED FLOODING ACROSS AREA
ROADS/HIGHWAYS/UNDERPASSES AND LOW LYING AND POOR DRAINAGE AREAS.
PREV DISCUSSION... /ISSUED 658 AM CST SAT NOV 22 2014/
UPDATE...
THE KDRT UPPER AIR SOUNDING JUST CAME IN AND IS SHOWING
SUBSTANTIAL MID-LEVEL LAPSE RATES ABOVE A LIFTING CAP. THIS CAP
SHOULD COMPLETELY ERODE SHORTLY AS LIFT CONTINUES TO OVERSPREAD
THE AREA. THE 700-500MB LAPSE RATES ON THE SOUNDING ARE PUSHING 9
C/KM. THE 500 TEMPERATURE COOLED FROM -12C TO -17C IN JUST 12
HOURS. WE ARE GETTING MORE CONCERNED WITH THE SEVERE HAIL
POTENTIAL FROM ANY STORMS WHICH ARE ABLE TO BECOME ROOTED AND
SUSTAINED. ANOTHER CONCERNING CHANGE IS REDEVELOPMENT SHOWING UP
ON THE HRRR. THE HRRR IS OUT NOW TO 1Z AND IS SHOWING
REDEVELOPMENT OF WHAT IS MOST LIKELY TO BE STRONG TO SEVERE
THUNDERSTORMS ALONG THE I-35 CORRIDOR BY 23-00Z. THIS WAS SHOWN
THE PAST SEVERAL DAYS FROM THE NAM...BUT NOW THAT THERE IS SUPPORT
FROM THE HRRR THERE MAY BE SOMETHING TO IT. UPDATED THE GRIDS TO
INCREASE POPS AFTER 00Z FOR AREAS NEAR THE I-35 CORRIDOR. ANOTHER
ASPECT TO THIS IS IF WE GET ANOTHER ROUND OF STORMS...FORECASTED
RAIN TOTALS WILL INCREASE AS WELL. UPDATED THE HWO TO MENTION
ISOLATED 5 INCH TOTALS AND LOCALIZED FLASH FLOODING.
HAMPSHIRE
PREV DISCUSSION... /ISSUED 529 AM CST SAT NOV 22 2014/
AVIATION DISCUSSION...FOR 12Z TAF PACKAGE...
SCATTERED TO POTENTIALLY WIDESPREAD THUNDERSTORMS WILL BE POSSIBLE
FOR MAINLY THE I35 CORRIDOR TERMINALS THROUGHOUT MUCH OF THE TAF
PERIOD. SHORT TERM MODELS SUGGEST THAT STORM DEVELOPMENT WILL
OCCUR LATE MORNING IN THE VICINITY OF ALL TERMINALS BUT THE
MAJORITY OF THE DEVELOPMENT SHOULD BE ABOUT 50 MILES WEST OF THE
I35 CORRIDOR AND EAST.
BEGINNING 18Z AND LASTING THROUGH 03Z...POTENTIALLY SEVERE
THUNDERSTORMS WILL IMPACT TERMINALS OFF AND ON. INCLUDED +TSRA
WITH IFR VIS TO ENCOMPASS THE MAIN IMPACTS TO THE TERMINALS. CIGS
SHOULD REMAIN AT MVFR LEVELS DURING THE DAY BUT MAY DIP TO IFR
DURING THE MORE SIGNIFICANT STORMS. EXPECT THESE IMPACTS TO EXIT
QUICKLY FROM THE AREA AFTER 03Z. THEN VFR SHOULD PREVAIL DURING
THE REMAINDER OF THE PERIOD.
NOTE FOR KDRT...MODELS SUGGEST A SECOND ROUND OF TSRA TO DEVELOP
IN THE VICINITY NEAR 00Z. THIS IS A RECENT BUT CONSISTENT
DEVELOPMENT IN THE MODELS SO INCLUDED PROB30 MENTION TO ACCOUNT
FOR THIS.
PREV DISCUSSION... /ISSUED 342 AM CST SAT NOV 22 2014/
SHORT TERM (TODAY THROUGH SUNDAY)...
LIGHT SHOWER ACTIVITY REMAINS SCATTERED AROUND THE AREA IN
RESPONSE TO CONTINUED WEAK LIFT ASSOCIATED WITH THE LOW-LEVEL JET.
THE JET IS STRONGEST ACROSS THE CENTRAL AND WESTERN ZONES AND THIS
IS WHERE THE HIGHEST CONCENTRATION OF ACTIVITY IS LOCATED. THE
POTENT UPPER LEVEL LOW IS CURRENTLY LOCATED OVER NORTHERN MEXICO
AND IT CONTINUES TO MOVE EAST. THE LARGE SCALE FORCING FOR ASCENT
CAN EASILY BE SEEN ON IR/WV SATELLITE IMAGERY AT THE PRESENT TIME.
THE FORCING IS SHOWN BY THE INCREASING MID-HIGH LEVEL CLOUDS THAT
ARE OVERSPREADING WEST TEXAS. THE MAIN UPPER FORCING SHOULD ARRIVE
TO SOUTH CENTRAL TEXAS LATER THIS MORNING AND CONTINUE THROUGH THE
AFTERNOON AND EVENING HOURS. UNTIL THE MAIN UPPER FOCUS FOR LIFT
ARRIVES...WE SHOULD ONLY CONTINUE TO SEE THIS ISOLATED TO
SCATTERED SHOWER ACTIVITY WITH PERHAPS AN ISOLATED THUNDERSTORM.
THUNDERSTORMS WILL MOST LIKELY BEGIN TO INCREASE IN COVERAGE IN
THE MID TO LATE MORNING HOURS AS THE UPPER LIFT ARRIVES. INITIALLY
THERE WILL BE ABOUT 1500 J/KG OF CAPE ACROSS THE WESTERN HALF OF
THE CWA WITH 30-35 KNOTS OF 0-6 KM SHEAR. CAPE VALUES WILL DROP
OFF TO 1000 J/KG OR LESS ACROSS THE EASTERN ZONES. THE INITIAL
DEVELOPMENT OF STORMS COULD LEAD TO WEAK SUPERCELLS IN THE WESTERN
HALF OF THE CWA IN THE AREA OF BEST INSTABILITY. HOWEVER...ONCE
ACTIVITY BECOMES MORE WIDESPREAD THIS AFTERNOON...THERE MAY END UP
BEING TOO MUCH ACTIVITY TO REALIZE THE PEAK CAPE VALUES. HIGH-RES
GUIDANCE IS CONSISTENTLY SHOWING A LARGE AREA OF PRECIP OVER THE
CWA THAT MOVES FROM WEST TO EAST AND OUT OF THE CWA BY 03Z. THE
SHERB PARAMETER WHICH IS DECENT IN PICKING UP SEVERE POTENTIAL FOR
THESE LOW CAPE/HIGH SHEAR ENVIRONMENTS /EASTERN ZONES/ IS LESS
THAN WHAT WAS FORECASTED YESTERDAY...BUT IS STILL NEAR THE
THRESHOLD TO SUPPORT THE NOTION FOR SOME POSSIBLE SEVERE WIND
GUSTS OUT OF ANY LINE SEGMENTS WHICH FORM WITHIN THE LARGE MASS OF
THUNDERSTORMS. CURRENT THINKING IS THAT INITIALLY...SOME
THUNDERSTORMS COULD PRODUCE MARGINALLY SEVERE HAIL MAINLY ACROSS
THE WESTERN HALF OF THE AREA DURING THE LATE MORNING AND INTO THE
EARLY AFTERNOON. THEN...SOME MARGINALLY SEVERE WIND GUSTS WOULD
BE THE MAIN MODE OF SEVERE CONVECTION FROM ANY POSSIBLE LINE
SEGMENTS IN THE EASTERN ZONES. THE RISK FOR TORNADOES IS NON-
ZERO...BUT LOW WITH THE BEST POTENTIAL BEING IN THE SOUTHEAST
ZONES...WHERE THE BEST LOW-LEVEL SHEAR IS LOCATED.
PW VALUES WILL RISE UP TO 1.5 INCHES ACROSS THE EASTERN AND
NORTHERN ZONES. THIS IS ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL
FOR THIS TIME OF THE YEAR. THEREFORE...WE COULD SEE LOCALLY HEAVY
RAINFALL...MAINLY ACROSS THESE MENTIONED AREAS. WPC DAY 1 QPF
VALUES RANGE FROM NEAR 1/4 OF AN INCH NEAR THE RIO GRANDE TO NEAR
2 INCHES IN OUR NORTHERN ZONES. THIS SEEMS REASONABLE...BUT SOME
ISOLATED LOCATIONS COULD RECEIVE UP TO 4 INCHES OF RAIN.
ALL ACTIVITY IS EXPECTED TO BE EAST OF THE AREA BY 3Z OR 9 PM.
WEST WINDS AT THE SURFACE WILL CONTINUE ON SUNDAY GIVING US A
DOWNSLOPE COMPONENT FROM WEST TO EAST. THIS USUALLY LEADS TO WARM
TEMPERATURES AND HIGHS SUNDAY WILL REACH THE MID 70S TO NEAR 80
DEGREES.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
THE WEATHER IN THE EXTENDED IS EXPECTED TO BE FAIRLY QUIET. A WEAK
FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT IS IN
RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS. THIS
FRONT WILL BE DRY AS MOISTURE WILL REMAIN SHUNTED OFF TO THE EAST.
THE REST OF THE WEEK WILL REMAIN DRY AND THE NEXT FRONT SHOULD
MOVE INTO THE AREA AROUND FRIDAY. THE WEATHER FOR THANKSGIVING
SHOULD BE PRETTY SEASONAL WITH HIGHS IN THE 60S AND LOWS IN THE
30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 69 55 78 45 64 / 100 60 0 - -
AUSTIN BERGSTROM INTL AIRPORT 71 54 77 43 64 / 100 70 0 - -
NEW BRAUNFELS MUNI AIRPORT 75 55 79 45 66 / 90 60 0 - -
BURNET MUNI AIRPORT 67 52 75 42 62 / 100 50 0 - -
DEL RIO INTL AIRPORT 73 50 78 46 65 / 40 20 0 - -
GEORGETOWN MUNI AIRPORT 68 54 75 43 62 / 100 60 0 - -
HONDO MUNI AIRPORT 73 49 77 42 65 / 70 50 0 - -
SAN MARCOS MUNI AIRPORT 70 53 78 44 65 / 90 70 0 - -
LA GRANGE - FAYETTE REGIONAL 73 57 78 46 64 / 90 90 0 - -
SAN ANTONIO INTL AIRPORT 75 54 78 46 66 / 80 60 0 - -
STINSON MUNI AIRPORT 76 54 79 46 66 / 80 60 0 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...17
PUBLIC SERVICE/DATA COLLECTION...00
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1120 AM CST SAT NOV 22 2014
.AVIATION...
AN UPPER LEVEL STORM SYSTEM WILL CONTINUE TO AFFECT THE REGION
TODAY. ALTHOUGH SCATTERED THUNDERSTORMS CURRENTLY SOUTHEAST OF
KLBB WILL CONTINUE TO MOVE TOWARDS KCDS...THIS ACTIVITY IS
EXPECTED TO TAKE A MORE EASTERLY MOVEMENT AND MAY NOT AFFECT THE
KCDS TERMINAL. WIDESPREAD LOW CIGS AND VISBYS ARE NOT EXPECTED TO
RETURN BUT THERE MAY BE A BRIEF REDUCTION IN FLIGHT CONDITIONS
THIS EVENING BEFORE WINDS TURN TO THE WEST-NORTHWEST. STRONG WINDS
ON THE BACK SIDE OF THIS SYSTEM WILL BEGIN TO INCREASE SURFACE
WINDS BY LATE SUNDAY MORNING AT BOTH TAF SITES. GIVEN THE TIME OF
YEAR...IT IS UNCLEAR ON WHETHER THERE WILL BE ANY VISBY
RESTRICTIONS DUE TO BLDU.
&&
.PREV DISCUSSION... /ISSUED 906 AM CST SAT NOV 22 2014/
UPDATE...
WATER VAPOR IMAGERY SHOWED AN AREA OF LIFT IN AN UPPER LEVEL
DIFFLUENT AREA MOVING OUT OF EXTREME SOUTHEASTERN NEW MEXICO INTO
THE SOUTHWESTERN SOUTH PLAINS. THIS LIFT WAS RESULTING IN SOME
THUNDERSTORM ACTIVITY WHERE SHORT TERM MODELS CURRENTLY SHOW NO
DEVELOPMENT. POPS HAVE BEEN RAISED FOR THE REMAINDER OF THE
MORNING IN ANTICIPATION FOR THIS ACTIVITY TO AFFECT THE SOUTHERN
SOUTH PLAINS. THIS LIFT IS THEN EXPECTED TO QUICKLY MOVE EAST THIS
AFTERNOON.
PREV DISCUSSION... /ISSUED 524 AM CST SAT NOV 22 2014/
AVIATION...
VLIFR FOG AND LIFR CLOUD DECKS HAVE DEVELOPED AT KCDS THIS
MORNING...WITH KLBB VIS DROPPING BELOW 10 SM AND FEW DECKS BELOW
2000 FT AGL. WILL EXPECT KLBB TO FURTHER DETERIORATE LATER THIS
MORNING TO MVFR FOG AND IFR DECKS. CONDITIONS WILL IMPROVE TO VFR
CATEGORY BY MID-MORNING. LIGHT AND VARIABLE WINDS WILL VEER TO THE
WEST SOUTHWEST THIS AFTN AND BECOME SLIGHTLY BREEZY TOWARDS THE
END OF TAF PERIOD.
PREV DISCUSSION... /ISSUED 214 AM CST SAT NOV 22 2014/
SHORT TERM...
MAIN FOCUS FOR THE SHORT TERM PERIOD CONTINUES TO BE THE UA LOW
DIGGING ESE ACROSS NWRN OLD MEXICO EARLY THIS MORNING...WHICH WILL
AID TO INCREASE PRECIP CHANCES LATER THIS MORNING.
AN AREA OF STRATUS AND FOGGY CONDITIONS ONCE AGAIN DEVELOPED ACROSS
ERN TEXAS AND OKLAHOMA PER 08Z METARS...THUS COINCIDING WITH THE
BEST SFC MOISTURE /DEWPOINTS IN THE 50S AND 60S/. LOW CLOUDS AND FOG
HAVE IMPACTED THE FAR SERN TX PANHANDLE...WHICH IS NOT SURPRISING
GIVEN A LOW TEMP-DEWPOINT SPREAD. THE HRRR SOLUTION HANDLED THE
EVOLUTION OF THE LOW CLOUDS AND FOG QUITE WELL YESTERDAY...AND SINCE
IT SHOWS A CONTINUAL WESTWARD DEVELOPMENT FOR THE NEXT SEVERAL HOURS
UNTIL MID-MORNING WHERE THEREAFTER CONDITIONS WILL IMPROVE...THIS
FORECAST PACKAGE WILL REFLECT THAT PROGRESSION.
AS PREVIOUSLY STATED...THE BEST MOISTURE AXIS WAS NOTED EAST OF THE
FA AND WITH THE AID OF A BIT OF UL SUPPORT FROM THE UA LOW ACROSS
NWRN OLD MEXICO...RADAR ANALYSIS DEPICTED SCATTERED SHOWERS
DEVELOPING ACROSS THE LOW ROLLING PLAINS AND BIG COUNTRY AREAS. WITH
THE LLJ PROGGED TO INCREASE TO 30-40 KTS ACROSS THE ROLLING PLAINS
WITHIN THE NEXT FEW HOURS COUPLED WITH INCREASING LARGE SCALE ASCENT
AND A MOISTENING ATMOSPHERE /PWATS INCREASING TO AOA 1.10
INCHES/...CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE
ON THE INCREASE PARTICULARLY ACROSS THE ROLLING PLAINS. SOME OF THIS
ACTIVITY COULD POSE A THREAT FOR MODERATE TO HEAVY RAINFALL AS
PWATS INCREASE TO ABOVE 1.00 INCH THROUGHOUT THIS MORNING.
FURTHERMORE...MID-LEVEL CAPE VALUES OF 1000-1500 J/KG COMBINED WITH
0-6 KM BULK SHEAR VALUES AOA 40 KTS...SUGGEST SOME OF THE ACTIVITY
COULD APPROACH STRONG LEVELS WITH HAIL BEING THE PRIMARY THREAT
/PARTICULARLY ACROSS THE LOW ROLLING PLAINS/. STORMS WILL LINGER INTO
EARLY AFTN WHERE THEREAFTER...MODEL SOUNDINGS EXHIBITING A DRYING
PROFILE AND THE UA LOW MOVING EAST TOWARDS SE TX WILL RESULT IN
PRECIP EXITING THE REGION. BY LATE THIS EVENING/EARLY TONIGHT...A
DEEPENING SFC LOW PROGRESSING EAST ACROSS THE CENTRAL PLAINS WILL
PROMOTE W-SW SFC WINDS TO BECOME SLIGHTLY BREEZY BY THE END OF THE
SHORT TERM PERIOD.
TEMPS WILL BE A FEW DEGREES ABOVE NORM TODAY /MIDDLE TO UPPER 60S/
FOLLOWED BY A RELATIVELY MILD NIGHT /UPPER 30S TO MIDDLE 40S/.
LONG TERM...
NO SIGNIFICANT CHANGES TO THE FCST THIS MORNING. MODELS REMAIN
CONSISTENT IN KEEPING THE SRN HIGH PLAINS UNDERNEATH NORTHWESTERLY
FLOW ALOFT. A COUPLE OF SHORT WAVE TROUGHS MOVING THROUGH THIS
UPPER FLOW WILL PRODUCE A COUPLE PERIODS OF BREEZY TO WINDY
CONDITIONS SUNDAY AND MONDAY...THE STRONGEST WINDS COMING SUNDAY
ACROSS THE SWRN HALF OF THE FCST AREA...POSSIBLY MEETING ADVISORY
CRITERIA FOR A PERIOD OF TIME DURING THE AFTERNOON HOURS. TEMPS
NEAR OR JUST BELOW SEASONAL NORMS WITH THE WARMEST DAYS LIKELY
BEING WEDNESDAY AND THURSDAY. STILL SOME MODEL SOLUTIONS SHOWING
A BRIEF INCURSION OF COLD AIR TOWARD FRIDAY...BUT CERTAINLY NOW
CONSENSUS IN THAT REGARD ATTM.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 67 38 53 23 49 / 10 0 10 10 0
TULIA 67 40 53 25 52 / 20 10 10 10 0
PLAINVIEW 67 41 56 26 53 / 20 10 10 10 0
LEVELLAND 66 42 60 27 53 / 20 0 0 10 0
LUBBOCK 66 43 61 27 54 / 50 10 0 10 0
DENVER CITY 65 41 62 28 53 / 30 0 0 10 0
BROWNFIELD 65 42 61 28 54 / 50 10 0 10 0
CHILDRESS 67 45 62 32 56 / 60 10 0 10 0
SPUR 67 45 63 35 58 / 60 10 0 10 0
ASPERMONT 69 46 66 34 58 / 80 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1052 AM CST SAT NOV 22 2014
.UPDATE...
A SLIGHT RISK OF STRONG TO SEVERE WEATHER CONTINUES ACROSS ALL OF
SOUTH CENTRAL TEXAS FOR THE REST OF TODAY INTO THE EVENING HOURS.
A POTENT UPPER LEVEL STORM SYSTEM LOCATED ACROSS NORTHEAST MEXICO
IS FORECAST TO PUSH EAST AND OVER CENTRAL TEXAS THIS AFTERNOON AND EVENING.
BEST LIFT/UPPER DYNAMIC IS TO THE SOUTHEAST OF THE SHEAR AXIS AND
ABOUT TO CROSS THE SERRANIAS DEL BURRIO MOUNTAINS(NORTHEAST
MEXICO). THIS AREA OF BEST UPPER FORCING WILL MOVE ACROSS THE RIO
GRANDE WITHIN THE NEXT FEW HOURS. LATEST SATELLITE IMAGES ARE
SHOWING SOME BREAKS IN THE CLOUDS OVER THE SOUTHWESTERN COUNTIES AND
THIS COULD ENHANCE STORMS DEVELOPMENT AND SEVERITY. FOR THE
EASTERN PART OF SOUTH CENTRAL TEXAS...CLOUDS ARE EXPECTED TO REMAIN
WITH NO BREAKS ANTICIPATED. THE MAIN WEATHER THREAT FOR ALL OF
SOUTH CENTRAL TEXAS TODAY....STILL LARGE HAIL AND DAMIGING GUST WINDS.
CAN`T RULE OUT AND ISOLATED TORNADO OR TWO MAINLY ACROSS THE
SOUTHWEST AND FAR SOUTHEASTERN COUNTIES. HOWEVER...LATEST HIRES MODELS
AND AREA FORECAST SOUNDINGS ARE INDICATING PWATS OF 1.37 TO 1.48
INCHES. THESE NUMBERS ARE ABOVE THE 2 STANDARD DEVIATIONS FOR THIS
TIME OF THE YEAR. THEREFORE...THE POTENTIAL FOR HEAVY RAIN IS
LIKELY OVER SOME AREAS MAINLY ALONG AND EAST OF A MOUNTAIN HOME TO
CASTROVILLE TO CAMPBELLTON LINE. AS OF NOW...ISOLATED RAIN RATES
OF 2 TO 4 INCHES PER HOURS ARE BEING DETECTED BY EWX RADAR OVER
GILLESPIE AND BLANCO COUNTIES. THIS TREND WILL CONTINUE THROUGH
THE AFTERNOON HOURS AS THE UPPER LEVEL STORM SYSTEM PUSHES TO THE
EAST. EXPECT LOCALIZED FLOODING ACROSS AREA
ROADS/HIGHWAYS/UNDERPASSES AND LOW LYING AND POOR DRAINAGE AREAS.
&&
.PREV DISCUSSION... /ISSUED 658 AM CST SAT NOV 22 2014/
UPDATE...
THE KDRT UPPER AIR SOUNDING JUST CAME IN AND IS SHOWING
SUBSTANTIAL MID-LEVEL LAPSE RATES ABOVE A LIFTING CAP. THIS CAP
SHOULD COMPLETELY ERODE SHORTLY AS LIFT CONTINUES TO OVERSPREAD
THE AREA. THE 700-500MB LAPSE RATES ON THE SOUNDING ARE PUSHING 9
C/KM. THE 500 TEMPERATURE COOLED FROM -12C TO -17C IN JUST 12
HOURS. WE ARE GETTING MORE CONCERNED WITH THE SEVERE HAIL
POTENTIAL FROM ANY STORMS WHICH ARE ABLE TO BECOME ROOTED AND
SUSTAINED. ANOTHER CONCERNING CHANGE IS REDEVELOPMENT SHOWING UP
ON THE HRRR. THE HRRR IS OUT NOW TO 1Z AND IS SHOWING
REDEVELOPMENT OF WHAT IS MOST LIKELY TO BE STRONG TO SEVERE
THUNDERSTORMS ALONG THE I-35 CORRIDOR BY 23-00Z. THIS WAS SHOWN
THE PAST SEVERAL DAYS FROM THE NAM...BUT NOW THAT THERE IS SUPPORT
FROM THE HRRR THERE MAY BE SOMETHING TO IT. UPDATED THE GRIDS TO
INCREASE POPS AFTER 00Z FOR AREAS NEAR THE I-35 CORRIDOR. ANOTHER
ASPECT TO THIS IS IF WE GET ANOTHER ROUND OF STORMS...FORECASTED
RAIN TOTALS WILL INCREASE AS WELL. UPDATED THE HWO TO MENTION
ISOLATED 5 INCH TOTALS AND LOCALIZED FLASH FLOODING.
HAMPSHIRE
PREV DISCUSSION... /ISSUED 529 AM CST SAT NOV 22 2014/
AVIATION DISCUSSION...FOR 12Z TAF PACKAGE...
SCATTERED TO POTENTIALLY WIDESPREAD THUNDERSTORMS WILL BE POSSIBLE
FOR MAINLY THE I35 CORRIDOR TERMINALS THROUGHOUT MUCH OF THE TAF
PERIOD. SHORT TERM MODELS SUGGEST THAT STORM DEVELOPMENT WILL
OCCUR LATE MORNING IN THE VICINITY OF ALL TERMINALS BUT THE
MAJORITY OF THE DEVELOPMENT SHOULD BE ABOUT 50 MILES WEST OF THE
I35 CORRIDOR AND EAST.
BEGINNING 18Z AND LASTING THROUGH 03Z...POTENTIALLY SEVERE
THUNDERSTORMS WILL IMPACT TERMINALS OFF AND ON. INCLUDED +TSRA
WITH IFR VIS TO ENCOMPASS THE MAIN IMPACTS TO THE TERMINALS. CIGS
SHOULD REMAIN AT MVFR LEVELS DURING THE DAY BUT MAY DIP TO IFR
DURING THE MORE SIGNIFICANT STORMS. EXPECT THESE IMPACTS TO EXIT
QUICKLY FROM THE AREA AFTER 03Z. THEN VFR SHOULD PREVAIL DURING
THE REMAINDER OF THE PERIOD.
NOTE FOR KDRT...MODELS SUGGEST A SECOND ROUND OF TSRA TO DEVELOP
IN THE VICINITY NEAR 00Z. THIS IS A RECENT BUT CONSISTENT
DEVELOPMENT IN THE MODELS SO INCLUDED PROB30 MENTION TO ACCOUNT
FOR THIS.
PREV DISCUSSION... /ISSUED 342 AM CST SAT NOV 22 2014/
SHORT TERM (TODAY THROUGH SUNDAY)...
LIGHT SHOWER ACTIVITY REMAINS SCATTERED AROUND THE AREA IN
RESPONSE TO CONTINUED WEAK LIFT ASSOCIATED WITH THE LOW-LEVEL JET.
THE JET IS STRONGEST ACROSS THE CENTRAL AND WESTERN ZONES AND THIS
IS WHERE THE HIGHEST CONCENTRATION OF ACTIVITY IS LOCATED. THE
POTENT UPPER LEVEL LOW IS CURRENTLY LOCATED OVER NORTHERN MEXICO
AND IT CONTINUES TO MOVE EAST. THE LARGE SCALE FORCING FOR ASCENT
CAN EASILY BE SEEN ON IR/WV SATELLITE IMAGERY AT THE PRESENT TIME.
THE FORCING IS SHOWN BY THE INCREASING MID-HIGH LEVEL CLOUDS THAT
ARE OVERSPREADING WEST TEXAS. THE MAIN UPPER FORCING SHOULD ARRIVE
TO SOUTH CENTRAL TEXAS LATER THIS MORNING AND CONTINUE THROUGH THE
AFTERNOON AND EVENING HOURS. UNTIL THE MAIN UPPER FOCUS FOR LIFT
ARRIVES...WE SHOULD ONLY CONTINUE TO SEE THIS ISOLATED TO
SCATTERED SHOWER ACTIVITY WITH PERHAPS AN ISOLATED THUNDERSTORM.
THUNDERSTORMS WILL MOST LIKELY BEGIN TO INCREASE IN COVERAGE IN
THE MID TO LATE MORNING HOURS AS THE UPPER LIFT ARRIVES. INITIALLY
THERE WILL BE ABOUT 1500 J/KG OF CAPE ACROSS THE WESTERN HALF OF
THE CWA WITH 30-35 KNOTS OF 0-6 KM SHEAR. CAPE VALUES WILL DROP
OFF TO 1000 J/KG OR LESS ACROSS THE EASTERN ZONES. THE INITIAL
DEVELOPMENT OF STORMS COULD LEAD TO WEAK SUPERCELLS IN THE WESTERN
HALF OF THE CWA IN THE AREA OF BEST INSTABILITY. HOWEVER...ONCE
ACTIVITY BECOMES MORE WIDESPREAD THIS AFTERNOON...THERE MAY END UP
BEING TOO MUCH ACTIVITY TO REALIZE THE PEAK CAPE VALUES. HIGH-RES
GUIDANCE IS CONSISTENTLY SHOWING A LARGE AREA OF PRECIP OVER THE
CWA THAT MOVES FROM WEST TO EAST AND OUT OF THE CWA BY 03Z. THE
SHERB PARAMETER WHICH IS DECENT IN PICKING UP SEVERE POTENTIAL FOR
THESE LOW CAPE/HIGH SHEAR ENVIRONMENTS /EASTERN ZONES/ IS LESS
THAN WHAT WAS FORECASTED YESTERDAY...BUT IS STILL NEAR THE
THRESHOLD TO SUPPORT THE NOTION FOR SOME POSSIBLE SEVERE WIND
GUSTS OUT OF ANY LINE SEGMENTS WHICH FORM WITHIN THE LARGE MASS OF
THUNDERSTORMS. CURRENT THINKING IS THAT INITIALLY...SOME
THUNDERSTORMS COULD PRODUCE MARGINALLY SEVERE HAIL MAINLY ACROSS
THE WESTERN HALF OF THE AREA DURING THE LATE MORNING AND INTO THE
EARLY AFTERNOON. THEN...SOME MARGINALLY SEVERE WIND GUSTS WOULD
BE THE MAIN MODE OF SEVERE CONVECTION FROM ANY POSSIBLE LINE
SEGMENTS IN THE EASTERN ZONES. THE RISK FOR TORNADOES IS NON-
ZERO...BUT LOW WITH THE BEST POTENTIAL BEING IN THE SOUTHEAST
ZONES...WHERE THE BEST LOW-LEVEL SHEAR IS LOCATED.
PW VALUES WILL RISE UP TO 1.5 INCHES ACROSS THE EASTERN AND
NORTHERN ZONES. THIS IS ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL
FOR THIS TIME OF THE YEAR. THEREFORE...WE COULD SEE LOCALLY HEAVY
RAINFALL...MAINLY ACROSS THESE MENTIONED AREAS. WPC DAY 1 QPF
VALUES RANGE FROM NEAR 1/4 OF AN INCH NEAR THE RIO GRANDE TO NEAR
2 INCHES IN OUR NORTHERN ZONES. THIS SEEMS REASONABLE...BUT SOME
ISOLATED LOCATIONS COULD RECEIVE UP TO 4 INCHES OF RAIN.
ALL ACTIVITY IS EXPECTED TO BE EAST OF THE AREA BY 3Z OR 9 PM.
WEST WINDS AT THE SURFACE WILL CONTINUE ON SUNDAY GIVING US A
DOWNSLOPE COMPONENT FROM WEST TO EAST. THIS USUALLY LEADS TO WARM
TEMPERATURES AND HIGHS SUNDAY WILL REACH THE MID 70S TO NEAR 80
DEGREES.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
THE WEATHER IN THE EXTENDED IS EXPECTED TO BE FAIRLY QUIET. A WEAK
FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT IS IN
RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS. THIS
FRONT WILL BE DRY AS MOISTURE WILL REMAIN SHUNTED OFF TO THE EAST.
THE REST OF THE WEEK WILL REMAIN DRY AND THE NEXT FRONT SHOULD
MOVE INTO THE AREA AROUND FRIDAY. THE WEATHER FOR THANKSGIVING
SHOULD BE PRETTY SEASONAL WITH HIGHS IN THE 60S AND LOWS IN THE
30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 69 56 80 46 64 / 100 60 0 - -
AUSTIN BERGSTROM INTL AIRPORT 71 56 80 46 64 / 100 70 0 - -
NEW BRAUNFELS MUNI AIRPORT 75 56 81 46 65 / 90 60 0 - -
BURNET MUNI AIRPORT 67 53 77 42 62 / 100 50 0 - -
DEL RIO INTL AIRPORT 73 51 80 46 65 / 40 20 0 - -
GEORGETOWN MUNI AIRPORT 68 55 78 44 62 / 100 60 0 - -
HONDO MUNI AIRPORT 73 53 78 45 64 / 70 50 0 - -
SAN MARCOS MUNI AIRPORT 70 56 80 45 64 / 90 70 0 - -
LA GRANGE - FAYETTE REGIONAL 73 57 79 46 64 / 90 90 0 - -
SAN ANTONIO INTL AIRPORT 75 55 80 46 65 / 80 60 0 - -
STINSON MUNI AIRPORT 76 56 81 47 66 / 80 60 0 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...17
PUBLIC SERVICE/DATA COLLECTION...00
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
906 AM CST SAT NOV 22 2014
.UPDATE...
WATER VAPOR IMAGERY SHOWED AN AREA OF LIFT IN AN UPPER LEVEL
DIFFLUENT AREA MOVING OUT OF EXTREME SOUTHEASTERN NEW MEXICO INTO
THE SOUTHWESTERN SOUTH PLAINS. THIS LIFT WAS RESULTING IN SOME
THUNDERSTORM ACTIVITY WHERE SHORT TERM MODELS CURRENTLY SHOW NO
DEVELOPMENT. POPS HAVE BEEN RAISED FOR THE REMAINDER OF THE
MORNING IN ANTICIPATION FOR THIS ACTIVITY TO AFFECT THE SOUTHERN
SOUTH PLAINS. THIS LIFT IS THEN EXPECTED TO QUICKLY MOVE EAST THIS
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 524 AM CST SAT NOV 22 2014/
AVIATION...
VLIFR FOG AND LIFR CLOUD DECKS HAVE DEVELOPED AT KCDS THIS
MORNING...WITH KLBB VIS DROPPING BELOW 10 SM AND FEW DECKS BELOW
2000 FT AGL. WILL EXPECT KLBB TO FURTHER DETERIORATE LATER THIS
MORNING TO MVFR FOG AND IFR DECKS. CONDITIONS WILL IMPROVE TO VFR
CATEGORY BY MID-MORNING. LIGHT AND VARIABLE WINDS WILL VEER TO THE
WEST SOUTHWEST THIS AFTN AND BECOME SLIGHTLY BREEZY TOWARDS THE
END OF TAF PERIOD.
PREV DISCUSSION... /ISSUED 214 AM CST SAT NOV 22 2014/
SHORT TERM...
MAIN FOCUS FOR THE SHORT TERM PERIOD CONTINUES TO BE THE UA LOW
DIGGING ESE ACROSS NWRN OLD MEXICO EARLY THIS MORNING...WHICH WILL
AID TO INCREASE PRECIP CHANCES LATER THIS MORNING.
AN AREA OF STRATUS AND FOGGY CONDITIONS ONCE AGAIN DEVELOPED ACROSS
ERN TEXAS AND OKLAHOMA PER 08Z METARS...THUS COINCIDING WITH THE
BEST SFC MOISTURE /DEWPOINTS IN THE 50S AND 60S/. LOW CLOUDS AND FOG
HAVE IMPACTED THE FAR SERN TX PANHANDLE...WHICH IS NOT SURPRISING
GIVEN A LOW TEMP-DEWPOINT SPREAD. THE HRRR SOLUTION HANDLED THE
EVOLUTION OF THE LOW CLOUDS AND FOG QUITE WELL YESTERDAY...AND SINCE
IT SHOWS A CONTINUAL WESTWARD DEVELOPMENT FOR THE NEXT SEVERAL HOURS
UNTIL MID-MORNING WHERE THEREAFTER CONDITIONS WILL IMPROVE...THIS
FORECAST PACKAGE WILL REFLECT THAT PROGRESSION.
AS PREVIOUSLY STATED...THE BEST MOISTURE AXIS WAS NOTED EAST OF THE
FA AND WITH THE AID OF A BIT OF UL SUPPORT FROM THE UA LOW ACROSS
NWRN OLD MEXICO...RADAR ANALYSIS DEPICTED SCATTERED SHOWERS
DEVELOPING ACROSS THE LOW ROLLING PLAINS AND BIG COUNTRY AREAS. WITH
THE LLJ PROGGED TO INCREASE TO 30-40 KTS ACROSS THE ROLLING PLAINS
WITHIN THE NEXT FEW HOURS COUPLED WITH INCREASING LARGE SCALE ASCENT
AND A MOISTENING ATMOSPHERE /PWATS INCREASING TO AOA 1.10
INCHES/...CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE
ON THE INCREASE PARTICULARLY ACROSS THE ROLLING PLAINS. SOME OF THIS
ACTIVITY COULD POSE A THREAT FOR MODERATE TO HEAVY RAINFALL AS
PWATS INCREASE TO ABOVE 1.00 INCH THROUGHOUT THIS MORNING.
FURTHERMORE...MID-LEVEL CAPE VALUES OF 1000-1500 J/KG COMBINED WITH
0-6 KM BULK SHEAR VALUES AOA 40 KTS...SUGGEST SOME OF THE ACTIVITY
COULD APPROACH STRONG LEVELS WITH HAIL BEING THE PRIMARY THREAT
/PARTICULARLY ACROSS THE LOW ROLLING PLAINS/. STORMS WILL LINGER INTO
EARLY AFTN WHERE THEREAFTER...MODEL SOUNDINGS EXHIBITING A DRYING
PROFILE AND THE UA LOW MOVING EAST TOWARDS SE TX WILL RESULT IN
PRECIP EXITING THE REGION. BY LATE THIS EVENING/EARLY TONIGHT...A
DEEPENING SFC LOW PROGRESSING EAST ACROSS THE CENTRAL PLAINS WILL
PROMOTE W-SW SFC WINDS TO BECOME SLIGHTLY BREEZY BY THE END OF THE
SHORT TERM PERIOD.
TEMPS WILL BE A FEW DEGREES ABOVE NORM TODAY /MIDDLE TO UPPER 60S/
FOLLOWED BY A RELATIVELY MILD NIGHT /UPPER 30S TO MIDDLE 40S/.
LONG TERM...
NO SIGNIFICANT CHANGES TO THE FCST THIS MORNING. MODELS REMAIN
CONSISTENT IN KEEPING THE SRN HIGH PLAINS UNDERNEATH NORTHWESTERLY
FLOW ALOFT. A COUPLE OF SHORT WAVE TROUGHS MOVING THROUGH THIS
UPPER FLOW WILL PRODUCE A COUPLE PERIODS OF BREEZY TO WINDY
CONDITIONS SUNDAY AND MONDAY...THE STRONGEST WINDS COMING SUNDAY
ACROSS THE SWRN HALF OF THE FCST AREA...POSSIBLY MEETING ADVISORY
CRITERIA FOR A PERIOD OF TIME DURING THE AFTERNOON HOURS. TEMPS
NEAR OR JUST BELOW SEASONAL NORMS WITH THE WARMEST DAYS LIKELY
BEING WEDNESDAY AND THURSDAY. STILL SOME MODEL SOLUTIONS SHOWING
A BRIEF INCURSION OF COLD AIR TOWARD FRIDAY...BUT CERTAINLY NOW
CONSENSUS IN THAT REGARD ATTM.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 67 38 53 23 49 / 10 0 10 10 0
TULIA 67 40 53 25 52 / 20 10 10 10 0
PLAINVIEW 67 41 56 26 53 / 20 10 10 10 0
LEVELLAND 66 42 60 27 53 / 20 0 0 10 0
LUBBOCK 66 43 61 27 54 / 50 10 0 10 0
DENVER CITY 65 41 62 28 53 / 30 0 0 10 0
BROWNFIELD 65 42 61 28 54 / 50 10 0 10 0
CHILDRESS 67 45 62 32 56 / 60 10 0 10 0
SPUR 67 45 63 35 58 / 60 10 0 10 0
ASPERMONT 69 46 66 34 58 / 80 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
658 AM CST SAT NOV 22 2014
.UPDATE...
THE KDRT UPPER AIR SOUNDING JUST CAME IN AND IS SHOWING
SUBSTANTIAL MID-LEVEL LAPSE RATES ABOVE A LIFTING CAP. THIS CAP
SHOULD COMPLETELY ERODE SHORTLY AS LIFT CONTINUES TO OVERSPREAD
THE AREA. THE 700-500MB LAPSE RATES ON THE SOUNDING ARE PUSHING 9
C/KM. THE 500 TEMPERATURE COOLED FROM -12C TO -17C IN JUST 12
HOURS. WE ARE GETTING MORE CONCERNED WITH THE SEVERE HAIL
POTENTIAL FROM ANY STORMS WHICH ARE ABLE TO BECOME ROOTED AND
SUSTAINED. ANOTHER CONCERNING CHANGE IS REDEVELOPMENT SHOWING UP
ON THE HRRR. THE HRRR IS OUT NOW TO 1Z AND IS SHOWING
REDEVELOPMENT OF WHAT IS MOST LIKELY TO BE STRONG TO SEVERE
THUNDERSTORMS ALONG THE I-35 CORRIDOR BY 23-00Z. THIS WAS SHOWN
THE PAST SEVERAL DAYS FROM THE NAM...BUT NOW THAT THERE IS SUPPORT
FROM THE HRRR THERE MAY BE SOMETHING TO IT. UPDATED THE GRIDS TO
INCREASE POPS AFTER 00Z FOR AREAS NEAR THE I-35 CORRIDOR. ANOTHER
ASPECT TO THIS IS IF WE GET ANOTHER ROUND OF STORMS...FORECASTED
RAIN TOTALS WILL INCREASE AS WELL. UPDATED THE HWO TO MENTION
ISOLATED 5 INCH TOTALS AND LOCALIZED FLASH FLOODING.
HAMPSHIRE
&&
.PREV DISCUSSION... /ISSUED 529 AM CST SAT NOV 22 2014/
AVIATION DISCUSSION...FOR 12Z TAF PACKAGE...
SCATTERED TO POTENTIALLY WIDESPREAD THUNDERSTORMS WILL BE POSSIBLE
FOR MAINLY THE I35 CORRIDOR TERMINALS THROUGHOUT MUCH OF THE TAF
PERIOD. SHORT TERM MODELS SUGGEST THAT STORM DEVELOPMENT WILL
OCCUR LATE MORNING IN THE VICINITY OF ALL TERMINALS BUT THE
MAJORITY OF THE DEVELOPMENT SHOULD BE ABOUT 50 MILES WEST OF THE
I35 CORRIDOR AND EAST.
BEGINNING 18Z AND LASTING THROUGH 03Z...POTENTIALLY SEVERE
THUNDERSTORMS WILL IMPACT TERMINALS OFF AND ON. INCLUDED +TSRA
WITH IFR VIS TO ENCOMPASS THE MAIN IMPACTS TO THE TERMINALS. CIGS
SHOULD REMAIN AT MVFR LEVELS DURING THE DAY BUT MAY DIP TO IFR
DURING THE MORE SIGNIFICANT STORMS. EXPECT THESE IMPACTS TO EXIT
QUICKLY FROM THE AREA AFTER 03Z. THEN VFR SHOULD PREVAIL DURING
THE REMAINDER OF THE PERIOD.
NOTE FOR KDRT...MODELS SUGGEST A SECOND ROUND OF TSRA TO DEVELOP
IN THE VICINITY NEAR 00Z. THIS IS A RECENT BUT CONSISTENT
DEVELOPMENT IN THE MODELS SO INCLUDED PROB30 MENTION TO ACCOUNT
FOR THIS.
PREV DISCUSSION... /ISSUED 342 AM CST SAT NOV 22 2014/
SHORT TERM (TODAY THROUGH SUNDAY)...
LIGHT SHOWER ACTIVITY REMAINS SCATTERED AROUND THE AREA IN
RESPONSE TO CONTINUED WEAK LIFT ASSOCIATED WITH THE LOW-LEVEL JET.
THE JET IS STRONGEST ACROSS THE CENTRAL AND WESTERN ZONES AND THIS
IS WHERE THE HIGHEST CONCENTRATION OF ACTIVITY IS LOCATED. THE
POTENT UPPER LEVEL LOW IS CURRENTLY LOCATED OVER NORTHERN MEXICO
AND IT CONTINUES TO MOVE EAST. THE LARGE SCALE FORCING FOR ASCENT
CAN EASILY BE SEEN ON IR/WV SATELLITE IMAGERY AT THE PRESENT TIME.
THE FORCING IS SHOWN BY THE INCREASING MID-HIGH LEVEL CLOUDS THAT
ARE OVERSPREADING WEST TEXAS. THE MAIN UPPER FORCING SHOULD ARRIVE
TO SOUTH CENTRAL TEXAS LATER THIS MORNING AND CONTINUE THROUGH THE
AFTERNOON AND EVENING HOURS. UNTIL THE MAIN UPPER FOCUS FOR LIFT
ARRIVES...WE SHOULD ONLY CONTINUE TO SEE THIS ISOLATED TO
SCATTERED SHOWER ACTIVITY WITH PERHAPS AN ISOLATED THUNDERSTORM.
THUNDERSTORMS WILL MOST LIKELY BEGIN TO INCREASE IN COVERAGE IN
THE MID TO LATE MORNING HOURS AS THE UPPER LIFT ARRIVES. INITIALLY
THERE WILL BE ABOUT 1500 J/KG OF CAPE ACROSS THE WESTERN HALF OF
THE CWA WITH 30-35 KNOTS OF 0-6 KM SHEAR. CAPE VALUES WILL DROP
OFF TO 1000 J/KG OR LESS ACROSS THE EASTERN ZONES. THE INITIAL
DEVELOPMENT OF STORMS COULD LEAD TO WEAK SUPERCELLS IN THE WESTERN
HALF OF THE CWA IN THE AREA OF BEST INSTABILITY. HOWEVER...ONCE
ACTIVITY BECOMES MORE WIDESPREAD THIS AFTERNOON...THERE MAY END UP
BEING TOO MUCH ACTIVITY TO REALIZE THE PEAK CAPE VALUES. HIGH-RES
GUIDANCE IS CONSISTENTLY SHOWING A LARGE AREA OF PRECIP OVER THE
CWA THAT MOVES FROM WEST TO EAST AND OUT OF THE CWA BY 03Z. THE
SHERB PARAMETER WHICH IS DECENT IN PICKING UP SEVERE POTENTIAL FOR
THESE LOW CAPE/HIGH SHEAR ENVIRONMENTS /EASTERN ZONES/ IS LESS
THAN WHAT WAS FORECASTED YESTERDAY...BUT IS STILL NEAR THE
THRESHOLD TO SUPPORT THE NOTION FOR SOME POSSIBLE SEVERE WIND
GUSTS OUT OF ANY LINE SEGMENTS WHICH FORM WITHIN THE LARGE MASS OF
THUNDERSTORMS. CURRENT THINKING IS THAT INITIALLY...SOME
THUNDERSTORMS COULD PRODUCE MARGINALLY SEVERE HAIL MAINLY ACROSS
THE WESTERN HALF OF THE AREA DURING THE LATE MORNING AND INTO THE
EARLY AFTERNOON. THEN...SOME MARGINALLY SEVERE WIND GUSTS WOULD
BE THE MAIN MODE OF SEVERE CONVECTION FROM ANY POSSIBLE LINE
SEGMENTS IN THE EASTERN ZONES. THE RISK FOR TORNADOES IS NON-
ZERO...BUT LOW WITH THE BEST POTENTIAL BEING IN THE SOUTHEAST
ZONES...WHERE THE BEST LOW-LEVEL SHEAR IS LOCATED.
PW VALUES WILL RISE UP TO 1.5 INCHES ACROSS THE EASTERN AND
NORTHERN ZONES. THIS IS ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL
FOR THIS TIME OF THE YEAR. THEREFORE...WE COULD SEE LOCALLY HEAVY
RAINFALL...MAINLY ACROSS THESE MENTIONED AREAS. WPC DAY 1 QPF
VALUES RANGE FROM NEAR 1/4 OF AN INCH NEAR THE RIO GRANDE TO NEAR
2 INCHES IN OUR NORTHERN ZONES. THIS SEEMS REASONABLE...BUT SOME
ISOLATED LOCATIONS COULD RECEIVE UP TO 4 INCHES OF RAIN.
ALL ACTIVITY IS EXPECTED TO BE EAST OF THE AREA BY 3Z OR 9 PM.
WEST WINDS AT THE SURFACE WILL CONTINUE ON SUNDAY GIVING US A
DOWNSLOPE COMPONENT FROM WEST TO EAST. THIS USUALLY LEADS TO WARM
TEMPERATURES AND HIGHS SUNDAY WILL REACH THE MID 70S TO NEAR 80
DEGREES.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
THE WEATHER IN THE EXTENDED IS EXPECTED TO BE FAIRLY QUIET. A WEAK
FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT IS IN
RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS. THIS
FRONT WILL BE DRY AS MOISTURE WILL REMAIN SHUNTED OFF TO THE EAST.
THE REST OF THE WEEK WILL REMAIN DRY AND THE NEXT FRONT SHOULD
MOVE INTO THE AREA AROUND FRIDAY. THE WEATHER FOR THANKSGIVING
SHOULD BE PRETTY SEASONAL WITH HIGHS IN THE 60S AND LOWS IN THE
30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 69 56 80 46 64 / 100 60 0 - -
AUSTIN BERGSTROM INTL AIRPORT 71 56 80 46 64 / 100 70 0 - -
NEW BRAUNFELS MUNI AIRPORT 75 56 81 46 65 / 90 60 0 - -
BURNET MUNI AIRPORT 67 53 77 42 62 / 100 50 0 - -
DEL RIO INTL AIRPORT 73 51 80 46 65 / 40 20 0 - -
GEORGETOWN MUNI AIRPORT 68 55 78 44 62 / 100 60 0 - -
HONDO MUNI AIRPORT 73 53 78 45 64 / 70 50 0 - -
SAN MARCOS MUNI AIRPORT 70 56 80 45 64 / 90 70 0 - -
LA GRANGE - FAYETTE REGIONAL 73 57 79 46 64 / 90 90 0 - -
SAN ANTONIO INTL AIRPORT 75 55 80 46 65 / 80 60 0 - -
STINSON MUNI AIRPORT 76 56 81 47 66 / 80 60 0 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...03
SYNOPTIC/GRIDS...29
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
524 AM CST SAT NOV 22 2014
.AVIATION...
VLIFR FOG AND LIFR CLOUD DECKS HAVE DEVELOPED AT KCDS THIS
MORNING...WITH KLBB VIS DROPPING BELOW 10 SM AND FEW DECKS BELOW
2000 FT AGL. WILL EXPECT KLBB TO FURTHER DETERIORATE LATER THIS
MORNING TO MVFR FOG AND IFR DECKS. CONDITIONS WILL IMPROVE TO VFR
CATEGORY BY MID-MORNING. LIGHT AND VARIABLE WINDS WILL VEER TO THE
WEST SOUTHWEST THIS AFTN AND BECOME SLIGHTLY BREEZY TOWARDS THE
END OF TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 214 AM CST SAT NOV 22 2014/
SHORT TERM...
MAIN FOCUS FOR THE SHORT TERM PERIOD CONTINUES TO BE THE UA LOW
DIGGING ESE ACROSS NWRN OLD MEXICO EARLY THIS MORNING...WHICH WILL
AID TO INCREASE PRECIP CHANCES LATER THIS MORNING.
AN AREA OF STRATUS AND FOGGY CONDITIONS ONCE AGAIN DEVELOPED ACROSS
ERN TEXAS AND OKLAHOMA PER 08Z METARS...THUS COINCIDING WITH THE
BEST SFC MOISTURE /DEWPOINTS IN THE 50S AND 60S/. LOW CLOUDS AND FOG
HAVE IMPACTED THE FAR SERN TX PANHANDLE...WHICH IS NOT SURPRISING
GIVEN A LOW TEMP-DEWPOINT SPREAD. THE HRRR SOLUTION HANDLED THE
EVOLUTION OF THE LOW CLOUDS AND FOG QUITE WELL YESTERDAY...AND SINCE
IT SHOWS A CONTINUAL WESTWARD DEVELOPMENT FOR THE NEXT SEVERAL HOURS
UNTIL MID-MORNING WHERE THEREAFTER CONDITIONS WILL IMPROVE...THIS
FORECAST PACKAGE WILL REFLECT THAT PROGRESSION.
AS PREVIOUSLY STATED...THE BEST MOISTURE AXIS WAS NOTED EAST OF THE
FA AND WITH THE AID OF A BIT OF UL SUPPORT FROM THE UA LOW ACROSS
NWRN OLD MEXICO...RADAR ANALYSIS DEPICTED SCATTERED SHOWERS
DEVELOPING ACROSS THE LOW ROLLING PLAINS AND BIG COUNTRY AREAS. WITH
THE LLJ PROGGED TO INCREASE TO 30-40 KTS ACROSS THE ROLLING PLAINS
WITHIN THE NEXT FEW HOURS COUPLED WITH INCREASING LARGE SCALE ASCENT
AND A MOISTENING ATMOSPHERE /PWATS INCREASING TO AOA 1.10
INCHES/...CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE
ON THE INCREASE PARTICULARLY ACROSS THE ROLLING PLAINS. SOME OF THIS
ACTIVITY COULD POSE A THREAT FOR MODERATE TO HEAVY RAINFALL AS
PWATS INCREASE TO ABOVE 1.00 INCH THROUGHOUT THIS MORNING.
FURTHERMORE...MID-LEVEL CAPE VALUES OF 1000-1500 J/KG COMBINED WITH
0-6 KM BULK SHEAR VALUES AOA 40 KTS...SUGGEST SOME OF THE ACTIVITY
COULD APPROACH STRONG LEVELS WITH HAIL BEING THE PRIMARY THREAT
/PARTICULARLY ACROSS THE LOW ROLLING PLAINS/. STORMS WILL LINGER INTO
EARLY AFTN WHERE THEREAFTER...MODEL SOUNDINGS EXHIBITING A DRYING
PROFILE AND THE UA LOW MOVING EAST TOWARDS SE TX WILL RESULT IN
PRECIP EXITING THE REGION. BY LATE THIS EVENING/EARLY TONIGHT...A
DEEPENING SFC LOW PROGRESSING EAST ACROSS THE CENTRAL PLAINS WILL
PROMOTE W-SW SFC WINDS TO BECOME SLIGHTLY BREEZY BY THE END OF THE
SHORT TERM PERIOD.
TEMPS WILL BE A FEW DEGREES ABOVE NORM TODAY /MIDDLE TO UPPER 60S/
FOLLOWED BY A RELATIVELY MILD NIGHT /UPPER 30S TO MIDDLE 40S/.
LONG TERM...
NO SIGNFICANT CHANGES TO THE FCST THIS MORNING. MODELS REMAIN
CONSISTENT IN KEEPING THE SRN HIGH PLAINS UNDERNEATH NORTHWESTERLY
FLOW ALOFT. A COUPLE OF SHORT WAVE TROUGHS MOVING THROUGH THIS
UPPER FLOW WILL PRODUCE A COUPLE PERIODS OF BREEZY TO WINDY
CONDITIONS SUNDAY AND MONDAY...THE STRONGEST WINDS COMING SUNDAY
ACROSS THE SWRN HALF OF THE FCST AREA...POSSIBLY MEETING ADVISORY
CRITERIA FOR A PERIOD OF TIME DURING THE AFTERNOON HOURS. TEMPS
NEAR OR JUST BELOW SEASONAL NORMS WITH THE WARMEST DAYS LIKELY
BEING WEDNESDAY AND THURSDAY. STILL SOME MODEL SOLUTIONS SHOWING
A BRIEF INCURSION OF COLD AIR TOWARD FRIDAY...BUT CERTAINLY NOW
CONSENSUS IN THAT REGARD ATTM.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 67 38 53 23 49 / 10 0 10 10 0
TULIA 67 40 53 25 52 / 10 10 10 10 0
PLAINVIEW 67 41 56 26 53 / 20 10 10 10 0
LEVELLAND 66 42 60 27 53 / 20 0 0 10 0
LUBBOCK 66 43 61 27 54 / 20 10 0 10 0
DENVER CITY 65 41 62 28 53 / 20 0 0 10 0
BROWNFIELD 65 42 61 28 54 / 20 10 0 10 0
CHILDRESS 67 45 62 32 56 / 30 10 0 10 0
SPUR 67 45 63 35 58 / 50 10 0 10 0
ASPERMONT 69 46 66 34 58 / 80 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
214 AM CST SAT NOV 22 2014
.SHORT TERM...
MAIN FOCUS FOR THE SHORT TERM PERIOD CONTINUES TO BE THE UA LOW
DIGGING ESE ACROSS NWRN OLD MEXICO EARLY THIS MORNING...WHICH WILL
AID TO INCREASE PRECIP CHANCES LATER THIS MORNING.
AN AREA OF STRATUS AND FOGGY CONDITIONS ONCE AGAIN DEVELOPED ACROSS
ERN TEXAS AND OKLAHOMA PER 08Z METARS...THUS COINCIDING WITH THE
BEST SFC MOISTURE /DEWPOINTS IN THE 50S AND 60S/. LOW CLOUDS AND FOG
HAVE IMPACTED THE FAR SERN TX PANHANDLE...WHICH IS NOT SURPRISING
GIVEN A LOW TEMP-DEWPOINT SPREAD. THE HRRR SOLUTION HANDLED THE
EVOLUTION OF THE LOW CLOUDS AND FOG QUITE WELL YESTERDAY...AND SINCE
IT SHOWS A CONTINUAL WESTWARD DEVELOPMENT FOR THE NEXT SEVERAL HOURS
UNTIL MID-MORNING WHERE THEREAFTER CONDITIONS WILL IMPROVE...THIS
FORECAST PACKAGE WILL REFLECT THAT PROGRESSION.
AS PREVIOUSLY STATED...THE BEST MOISTURE AXIS WAS NOTED EAST OF THE
FA AND WITH THE AID OF A BIT OF UL SUPPORT FROM THE UA LOW ACROSS
NWRN OLD MEXICO...RADAR ANALYSIS DEPICTED SCATTERED SHOWERS
DEVELOPING ACROSS THE LOW ROLLING PLAINS AND BIG COUNTRY AREAS. WITH
THE LLJ PROGGED TO INCREASE TO 30-40 KTS ACROSS THE ROLLING PLAINS
WITHIN THE NEXT FEW HOURS COUPLED WITH INCREASING LARGE SCALE ASCENT
AND A MOISTENING ATMOSPHERE /PWATS INCREASING TO AOA 1.10
INCHES/...CHANCES FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE
ON THE INCREASE PARTICULARLY ACROSS THE ROLLING PLAINS. SOME OF THIS
ACTIVITY COULD POSE A THREAT FOR MODERATE TO HEAVY RAINFALL AS
PWATS INCREASE TO ABOVE 1.00 INCH THROUGHOUT THIS MORNING.
FURTHERMORE...MID-LEVEL CAPE VALUES OF 1000-1500 J/KG COMBINED WITH
0-6 KM BULK SHEAR VALUES AOA 40 KTS...SUGGEST SOME OF THE ACTIVITY
COULD APPROACH STRONG LEVELS WITH HAIL BEING THE PRIMARY THREAT
/PARTICULARLY ACROSS THE LOW ROLLING PLAINS/. STORMS WILL LINGER INTO
EARLY AFTN WHERE THEREAFTER...MODEL SOUNDINGS EXHIBITING A DRYING
PROFILE AND THE UA LOW MOVING EAST TOWARDS SE TX WILL RESULT IN
PRECIP EXITING THE REGION. BY LATE THIS EVENING/EARLY TONIGHT...A
DEEPENING SFC LOW PROGRESSING EAST ACROSS THE CENTRAL PLAINS WILL
PROMOTE W-SW SFC WINDS TO BECOME SLIGHTLY BREEZY BY THE END OF THE
SHORT TERM PERIOD.
TEMPS WILL BE A FEW DEGREES ABOVE NORM TODAY /MIDDLE TO UPPER 60S/
FOLLOWED BY A RELATIVELY MILD NIGHT /UPPER 30S TO MIDDLE 40S/.
&&
.LONG TERM...
NO SIGNFICANT CHANGES TO THE FCST THIS MORNING. MODELS REMAIN
CONSISTENT IN KEEPING THE SRN HIGH PLAINS UNDERNEATH NORTHWESTERLY
FLOW ALOFT. A COUPLE OF SHORT WAVE TROUGHS MOVING THROUGH THIS
UPPER FLOW WILL PRODUCE A COUPLE PERIODS OF BREEZY TO WINDY
CONDITIONS SUNDAY AND MONDAY...THE STRONGEST WINDS COMING SUNDAY
ACROSS THE SWRN HALF OF THE FCST AREA...POSSIBLY MEETING ADVISORY
CRITERIA FOR A PERIOD OF TIME DURING THE AFTERNOON HOURS. TEMPS
NEAR OR JUST BELOW SEASONAL NORMS WITH THE WARMEST DAYS LIKELY
BEING WEDNESDAY AND THURSDAY. STILL SOME MODEL SOLUTIONS SHOWING
A BRIEF INCURSION OF COLD AIR TOWARD FRIDAY...BUT CERTAINLY NOW
CONSENSUS IN THAT REGARD ATTM.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 66 38 53 26 48 / 10 0 10 10 0
TULIA 66 40 56 30 50 / 20 10 10 10 0
PLAINVIEW 66 42 58 31 51 / 20 10 10 10 0
LEVELLAND 65 43 60 31 51 / 20 10 10 10 0
LUBBOCK 66 44 61 32 52 / 30 10 10 10 0
DENVER CITY 65 42 63 31 52 / 20 10 10 10 0
BROWNFIELD 66 43 63 31 53 / 30 10 10 10 0
CHILDRESS 65 45 63 37 56 / 60 10 10 10 0
SPUR 67 48 65 37 56 / 60 10 0 10 0
ASPERMONT 67 49 67 39 57 / 80 20 0 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29/07
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1135 PM CST FRI NOV 21 2014
.UPDATE...
06Z TAF DISCUSSION IN AVIATION SECTION.
&&
.DISCUSSION...
MAIN CONCERN NEXT 6 HRS FOR SE TX TERMINALS WILL BE CIGS. CIG
RANGE FROM IFR TO VFR FOR AREA AIRPORTS. THINK ALL AREAS WILL HAVE
AT LEST MVFR CIGS AND POSSIBLY A FEW SHOWERS IN THE MORNING. THE
00Z NAM/GFS STILL SUPPORT 2 TIME FRAMES FOR CONVECTION WHICH THE
TAFS CAPTURE. THERE WILL BE SOME ADJUSTMENTS TO THE TAFS FOR
TIMING OF THE CONVECTION. FIRST ROUND STILL LOOKS ON TRACK FOR THE
LATER AFTERNOON HOURS. SECOND ROUND WILL BE ASSOCIATED WITH THE
UPPER LOW MOVING ACROSS THE AREA. LOOK FOR STORMS TO BE OUT OF THE
AREA BY 09Z SUN MORNING. CIGS SHOULD IMPROVE QUITE A BIT AFTER
PACIFIC FRONT PUSHES ACROSS THE AREA.
39
&&
.PREV DISCUSSION... /ISSUED 936 PM CST FRI NOV 21 2014/
DISCUSSION...
NO CHANGES TO THIS UPDATE. THE BEST WARM AIR AND MOISTURE
ADVECTION WAS TO THE WEST OF THE FORECAST AREA...GENERALLY ACROSS
THE CENTRAL PART OF THE STATE. THE 00Z NAM12 AND THE HRRR BOTH
KEEP ISOLATED TO SCATTERED RAIN CHANCES OVER THE FAR WESTERN
COUNTIES THROUGH ABOUT 3 AM. CHANCES RETURN BY LATE MORNING ON
SATURDAY.
THE MAIN EVENT STILL LOOKS TO OCCUR SATURDAY AFTERNOON AND
EVENING. THE 00Z NAM12 AND HRRR ARE A BIT SLOWER THAN THE 18Z
TEXAS TECH WRF. THE NAM12 AND HRRR PUSH AN INITIAL LINE OF STORMS
INTO SE TX DURING THE LATE AFTERNOON TO EARLY EVENING TIME PERIOD.
A SQUALL LINE THEN DEVELOPS AND MOVES OVERHEAD LATE EVENING INTO
THE OVERNIGHT PERIOD SATURDAY NIGHT. THE TEXAS TECH WRF IS ABOUT 3
HOURS OR SO QUICKER WITH THE TIMING. AFTER LOOKING OVER THE 00Z
NAMBUFR MODEL SOUNDINGS...THE CURRENT THINKING IS STILL IN LINE
WITH THE PREVIOUS REGARDING THE SEVERE THREAT -- A SLIGHT RISK
FOR SEVERE STORMS WITH DAMAGING WINDS AND HAIL THE MAIN THREATS
AND ISOLATED TORNADOES POSSIBLE.
40
PREV DISCUSSION... /ISSUED 554 PM CST FRI NOV 21 2014/
DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
COMPLICATED FORECAST FOR AVIATION CONCERNS THE NEXT 24-30HRS.
CIGS TONIGHT SHOULD MOSTLY BE MVFR FOR SE TX TERMINALS. THERE IS
SOME VFR CIGS ALONG THE COAST BUT THOSE SHOULD FILL BACK IN AT
MVFR LEVELS. ONLY QUESTION WILL BE IFR CIGS WHICH LOOK MORE
POSSIBLE OVER KCLL/KUTS/KCXO BUT COULD EASILY DEVELOP OVER THE
HOUSTON AREA IN THE MORNING. MAY NEED TO ADD A TEMPO GROUP FOR IFR
WITH 06Z TAFS SHOULD THERE BE MORE CONFIDENCE IN IFR DEVELOPING.
MVFR CIGS SHOULD REMAIN AND MAY BECOME VFR IN THE AFTERNOON BUT
NOT AS LIKELY. WILL STICK WITH NAM/GFS SOLUTIONS FOR CONVECTIVE
TRENDS AT THIS MOMENT. UPPER LOW OVER AZ SHOULD BE OVER RIO GRANDE
VALLEY NEAR DRT BY 00Z SUN. LEAD SHORTWAVE SHOULD MOVE OVER SE TX
BY THIS TIME OR END OF CURRENT TAF. WAVE MAY INITIATE ONE ROUND OF
TSRA FOR THE AREA. MAIN UPPER LOW THEN MOVES TO ACT/AUS BY 06Z BY
WHICH A 2ND ROUND OF CONVECTION MAY AFFECT THE AREA. ADDED PROB30
GROUP FOR IAH TO ACCOUNT FOR THIS TIMING. OBVIOUSLY TAFS WILL
UNDERGO SEVERAL CHANGES AS THIS SYSTEM EVOLVES BUT THE MAIN
HIGHLIGHT IS TO EXPECT CONVECTION TOMORROW AFTERNOON AND NIGHT TO
DISRUPT AIRPORT OPERATIONS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 62 74 58 78 47 / 30 90 80 0 0
HOUSTON (IAH) 62 76 61 79 51 / 20 80 90 0 0
GALVESTON (GLS) 65 74 66 78 56 / 20 70 90 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH SATURDAY AFTERNOON
FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 4 AM CST SUNDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
&&
$$
DISCUSSION...40
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1043 PM EST SUN NOV 23 2014
.SYNOPSIS...
A WARM FRONT EXPECTED TO SHIFT NORTH OF US OVERNIGHT...RESULTING
IN A WARMUP FOR MONDAY...AHEAD OF A COLD FRONT TO OUR WEST. THE COLD
FRONT MOVES THROUGH MONDAY NIGHT INTO TUESDAY...RETURNING
TEMPERATURES TO BELOW NORMAL FOR THE REST OF THE WEEK. A STORM
MOVES ALONG THE SOUTHEAST COAST MIDWEEK WHICH COULD LEAD TO A
WHITE THANKSGIVING FOR SOME.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 1020 PM EST SUNDAY...
SHIELD OF RAIN MOVING ACROSS FASTER AND THIS WAS HANDLED FAIRLY
WELL BY THE LATEST RUNS OF THE HRRR AND 18Z LOCAL WRF. WILL DRY
THINGS OUT FASTER THAN EARLIER FORECAST...WITH MODEL SOUNDING
SUGGESTING A SMALL 1-3 HOUR WIND OF DRIZZLE AS DEEPER MOISTURE
PULLS OUT LEAVING BEHIND SHALLOW MOISTURE BELOW 8H. WILL JUST SEE
SPOTTY SHOWERS OVERNIGHT INTO MONDAY MORNING.
AS FOR THE WINDS...THE CORE OF THE 8H JET IS OVERHEAD AND THE FLOW
WILL START TO SHIFT MORE SOUTH THEN SSW AFTER MIDNIGHT. THE ENDING
TIME FOR 1 AM STILL SEEMS REASONABLE. HAVE NOT REALLY HAD ANY
GUSTS OVER 50 MPH...THOUGH THE TAZEWELL MIDDLE SCHOOL WEATHERBUG
SITE DID SHOW A 60 MPH GUST EARLIER.
TEMPS HAVE BUMPED UP IN SOUTHSIDE VA/NW NC PIEDMONT AS WEDGE
DISSIPATES. THE THREAT OF THUNDER LOOKS LIMITED SO REMOVED IT AS
RAIN MOVING OUT SOON.
DRY SLOT AND CLEARING IS PROBLEMATIC BUT THINK THE MOUNTAIN EMPIRE
INTO SE WV AND PORTIONS OF THE NEW RIVER VALLEY AND TN/NC BORDER
AREA WILL SEE SUNSHINE IN THE MORNING WHILE LOW LVL MOISTURE
REMAINS BANKED INTO THE BLUE RIDGE A LITTLE WHILE...AND POINTS
EAST.
PREVIOUS VALID DISCUSSION...
BROAD UPPER LEVEL 500H TROUGH WILL ENCOMPASS MUCH OF THE CENTRAL
CONUS FOR MONDAY TO START THE WORKWEEK. A COLD FRONT WILL APPROACH
FROM THE WEST MONDAY. A WARM SECTOR SOUTHERLY WINDS WILL RESULT IN A
BREEZY MILD MONDAY. 1000-500MB THICKNESS VALUES OF 565-570DM AND
850H TEMPERATURES AROUND PLUS 10C SUPPORT SURFACE TEMPERATURES FROM
AROUND 60 DEGREES IN THE MOUNTAINS TO THE LOWER 70S IN THE PIEDMONT.
THE SURFACE COLD FRONT CROSSES THE MOUNTAINS LATE IN THE DAY... WITH
GFS SOLUTION A LITTLE QUICKER THAN THE NAM/ECMWF.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 338 PM EST SUNDAY...
ON MONDAY NIGHT LOW LEVEL MOISTURE IS BANKED UP AGAINST THE WESTERN
SLOPES OF THE APPALACHIANS. MODELS ERODE LOW LEVEL MOISTURE ON
TUESDAY MORNING.
OVERALL PATTERN THIS TIME FRAME IS FOR SPLIT FLOW WITH AN ACTIVE
NORTHERN STREAM ALONG THE CANADIAN/NORTHERN U.S. BORDER AND SOUTHERN
STREAM THAT HAS A STRONG SHORT WAVE AT THE BASE OF THE TROF OVER THE
LOWER MISSISSIPPI VALLEY BY LATE TUESDAY. EVOLUTION AND TIMING OF
LONG WAVE TROF FROM POSITIVE TILT TO NEGATIVE TILT AND AMOUNT OF
PHASING BETWEEN THE TWO JET STREAMS WILL IMPACT THE RESULTING TRACK
OF THE GULF TO EAST COAST SURFACE LOW AND LOCATION OF THE HEAVIEST
PRECIPITATION. AT THIS TIME SPREAD IN DIFFERENT MODELS IS LARGE.
HIGHEST CONFIDENCE IS WITH THE TIMING BUT MUCH LOWER WITH THE
LOCATION AND TYPE OF PRECIPITATION. WILL BE LEANING TOWARD BLEND OF
THE ECMWF AND GFS AS SUGGESTED BY WPC.
MODELS SHOW MID ATLANTIC REGION IN THE RIGHT REAR QUADRANT OF A 170
KNOT UPPER JET BY LATE TUESDAY NIGHT. AT THE SURFACE THE COLD FRONT
MOVES OFF THE EAST COAST MONDAY NIGHT THEN HIGH PRESSURE BUILDS FROM
THE TENNESSEE VALLEY INTO THE MID ATLANTIC STATES ON TUESDAY. LOW
PRESSURE DEVELOPS IN THE GULF OF MEXICO ON TUESDAY...THEN TRACKS
ACROSS FLORIDA TUESDAY NIGHT. THE LOW SHOULD BE OFF THE SOUTH
CAROLINA COAST ON WEDNESDAY MORNING AS IT MOVES NORTHEAST AND BEGINS
TO DEEPEN.
ONCE THE LOCATION OF THE PRECIPITATION IS DETERMINED...TEMPERATURES
WILL INFLUENCE WHAT TYPE OF PRECIPITATION WILL OCCUR. EVEN TAKING THE
COOLER MET/SREF GUIDANCE FOR TEMPERATURES ON TUESDAY NIGHT AND
WEDNESDAY...SURFACE VALUES MAY STILL BE TOO WARM EAST OF THE BLUE
RIDGE TO SUPPORT ANYTHING BUT RAIN. HAVE USED PARTIAL THICKNESS
VALUES...MAINLY FROM THE GFS/ECMWF TO PLACE RAIN/SNOW LINE. THIS
WILL CHANGE AS THE EVENT DRAWS CLOSER.
LOOKED AT PROBABILITY FOR SNOW AND CORRELATION WITH PAST ANALOG
EVENTS. APPEARS THERE IS AT LEAST THE POTENTIAL FOR SOME WINTER
PRECIPITATION. SINCE WEDNESDAY IS A MAJOR TRAVEL DAY WILL MENTION
POTENTIAL FOR WINTER PRECIPITATION IN THE HAZARDOUS WEATHER
OUTLOOK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 130 PM EST SUNDAY...
THIS PORTION OF THE FORECAST STARTS WITH THE AFTERMATH OF WHAT
UNFOLDS TUESDAY NIGHT INTO WEDNESDAY EVENING. GIVEN THERE STILL IS
GENEROUS UNCERTAINTY IN THOSE EVENTS...THE EVENTS AFTERWARDS ARE
EQUALLY CHALLENGING. THE GENERAL CONSENSUS IS FOR A LOW/TROUGH TO
DEEPEN ACROSS THE GREAT LAKES/OHIO VALLEY AS THE SYSTEM ALONG THE
COAST HEADS NORTHEAST...AND MAKES WAY FOR THE UPSTREAM SYSTEM TO
ENTER OUR REGION. THE PAST FEW DAYS...GUIDANCE HAS TRANSITIONED THIS
SYSTEM FROM A SLOWER...MORE AMPLIFIED SYSTEM INTO ONE THAT IS MORE
PROGRESSIVE AND THE BULK OF ITS ENERGY REMAINS NORTH OF THE REGION
AS IT MOVES EASTWARD. THAT TREND CONTINUES TODAY. OUR FORECAST WILL
REFLECT LITTLE CHANGE FROM THE PRIOR DURING THE THURSDAY THROUGH
FRIDAY TIMEFRAME. THE HIGHLIGHTS HERE ARE UPSLOPE RAIN/SNOW SHOWERS
ACROSS SOUTHEAST WEST VIRGINIA AND NEIGHBORING COUNTIES OF SOUTHWEST
VIRGINIA. A DECENT NORTHWEST FLOW WILL HELP CLOUDS TO A MINIMUM EAST
OF THE CREST OF THE BLUE RIDGE AND ADD A TOUCH OF A WARMING
INFLUENCE. PARTLY TO MOSTLY CLOUDY SKIES AND COOLER TEMPERATURES
WILL BE THE RULE FOR THE MOUNTAINS.
SATURDAY INTO SUNDAY THE REGION TRANSITIONS INTO MORE OF A ZONAL
PATTERN. THERE IS CONSISTENCY IN EACH MODEL CONCERNING THAT FEATURE.
WHAT VARIES SIGNIFICANTLY IS THE TIMING...TRACK AND SPEED OF A
DISTURBANCE MOVING WITHIN THIS ZONAL FLOW THAT MAY OR MAY NOT IMPACT
OUR REGION. AT THIS TIME...HAVE PLACED THE GREATEST FORECAST WEIGHT
ON A MODEL CONSENSUS THAT OFFERS A SMALL CHANCE OF LIGHT RAIN/SNOW
MAINLY IN THE WESTERN PARTS OF THE AREA SATURDAY NIGHT INTO EARLY
SUNDAY WITH TEMPERATURES TRENDING MILDER OVER THE WEEKEND.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
AS OF 650 PM EST SUNDAY...
WINDS...RAIN AND CLOUDS WILL HINDER AVIATION OPERATIONS
THROUGH THE MORNING MONDAY.
CIGS WILL BE VARIABLE IN THE IFR/MVFR RANGE WITH LIGHT TO MODERATE
RAIN EXPECTED THIS EVENING INTO EARLY OVERNIGHT. THINK THE DECENT
RAIN WILL BE EXITING AFTER MIDNIGHT IN THE WESTERN TAF
SITES/BLF/LWB...AND LYH/DAN AFTER 07Z. WITH IN SITU WEDGE IN PLACE
EARLY THIS EVENING AND STRONG LLJ...WILL SEE A PERIOD OF LOW LVL
WIND SHEAR WHICH ENDS AFTER MIDNIGHT...AT ALL SITES.
OVERNIGHT...MAIN ISSUE WILL BE WHETHER LEFTOVER MOISTURE CAN LEAD
TO FOG...BUT THINK WITH SOUTH TO SSW WINDS APPEARING TO STAY UP
WILL BE LIMITED IN FOG DEVELOPMENT. WILL KEEP CIGS MVFR THOUGH
OVER MUCH OF THE NIGHT THOUGH SEEING DRY SLOT INTO AL/GA MAY BRING
VFR CIGS OR EVEN SCATTERING THEM OUT IN BLF BY DAWN.
SW WINDS AHEAD OF THE COLD FRONT TO KEEP VFR AT ALL TAF SITES BY
LATE MONDAY MORNING. THE ISSUE WILL BE THE WINDS WITH 10-15 KT
SUSTAINED GUSTING TO 20-30 KNOTS AT TIMES.
WIND WILL TURN MORE WESTERLY LATE IN THE TAF PERIOD BUT LEFT THAT
OUT FOR NOW IN THE TAFS GIVEN SUCH AN ACTIVE FIRST 12-18 HOURS.
CONFIDENCE FOR SUB VFR THROUGH TONIGHT IS HIGH...BUT LOW ON TIMING
OF IFR VS MVFR WITH RESPECT TO CIG/VSBY...AGAIN FLUCTUATIONS WILL
OCCUR BASED ON RAINFALL INTENSITY.
CONFIDENCE IS HIGHER MONDAY WITH RETURN TO VFR MOST
LOCATIONS...WITH A SMALL WINDOW IN THE MORNING OF MVFR.
EXTENDED DISCUSSION...
WINDS WILL STAY GUSTY MONDAY NIGHT BEHIND COLD FRONT....WITH
POTENTIAL FOR SUB VFR CIGS IN THE MTNS...WHILE VFR IS EXPECTED TO
THE EAST. ANOTHER STORM SYSTEM IS EXPECTED TO MOVE UP THE
SOUTHEAST COAST BY EARLY WEDNESDAY WHICH MAY BRING WINTRY PRECIP
TO THE AREA ALONG WITH SUB VFR AT ALL SITES. LOOKS LIKE FLIGHTS
WILL BE IMPACTED GREATLY ACROSS THE MID ATLANTIC INTO THE
NORTHEAST WITH THIS SYSTEM WITH STRONG WINDS EXPECTED ALONG WITH
WIDESPREAD PRECIPITATION. AROUND HERE LOOKS LIKE WE WILL
EXPERIENCE SUB VFR AT LEAST WED INTO EARLY THANKSGIVING BEFORE
HIGH PRESSURE WORKS IN FROM THE WEST...THOUGH WINDS MAY STAY UP
THROUGH THU NIGHT...WITH UPSLOPE LOWER CIGS AT BLF/LWB.
&&
.EQUIPMENT...
AS OF 215 PM EST FRIDAY...
THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT
OF SERVICE UNTIL PARTS ARRIVE TO REPLACE THE SENSOR. UNTIL THEN
THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS
STAFFED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR VAZ007-009.
NC...NONE.
WV...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR WVZ042.
&&
$$
SYNOPSIS...KK/MBS/WP
NEAR TERM...KK/WP
SHORT TERM...AMS
LONG TERM...DS
AVIATION...KK/WP
EQUIPMENT...RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
704 PM EST SUN NOV 23 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH ACROSS THE REGION TONIGHT. THE RAIN
MAY BE HEAVY AT TIMES THIS EVENING AND EARLY TONIGHT...AND WINDS
WILL BECOME QUITE GUSTY ACROSS THE MOUNTAIN EMPIRE REGION AND
OTHER HIGH ELEVATIONS WEST OF THE BLUE RIDGE. UNSEASONABLY WARM
CONDITIONS ARE EXPECTED MONDAY IN THE WAKE OF THIS SYSTEM...BEFORE
A COLD FRONT MOVES THROUGH MONDAY NIGHT INTO TUESDAY...RETURNING
TEMPERATURES TO BELOW NORMAL FOR THE REST OF THE WEEK. THERE IS
THE POTENTIAL FOR A COASTAL STORM TO IMPACT PARTS OF THE MID
ATLANTIC FOR MID WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 630 PM EST SUNDAY...
WINDS HAVE BEEN GUSTING UP TO 35-40 KTS AT BLF AND WEST...AS CORE
OF LLJ MOVES ACROSS THE CENTRAL APPALACHIANS. A FEW MORE HOURS ARE
EXPECTED OF HIGHER WINDS IN THE FAVORED WRN SLOPES WITH A SE
COMPONENT TO THE WIND. NOT GOING TO ADD SUMMERS OR WESTERN
GREENBRIER TO AN ADVISORY BUT WE COULD SEE A SMALL WINDOW REST OF
THE EVENING WHERE HIGHER RIDGES COULD GUST TO 45 TO 50 MPH...BUT
BY MIDNIGHT FLOW TURNS MORE SOUTH TO SSW...WITH MAIN JET MOVING
OUT.
RADAR SHOWING MORE OF A SOLID AREA OF RAIN MOVING NWD ACROSS NC
INTO SW VA. THE 21Z HRRR SHOWING THIS FAIRLY WELL WITH THE LOCAL
WRF NOT TOO FAR OFF...AND ADJUSTED POPS THROUGH MIDNIGHT TO
ACCOUNT FOR BETTER THREAT IN THE WEST. REGIONAL RADAR SHOWS THE
DRY SLOT MOVING ACROSS ERN AL/WRN GA INTO SRN TN....WITH UPPER
SHORTWAVE PUSHING EAST OF MEMPHIS TN. SOLID SHIELD OF RAIN WILL BE
LIFTING ACROSS BETWEEN NOW AND 1 AM...AND SHOULD CLEAR OUR CWA
AFTER 1-2 AM.
ADJUSTED TEMPS DOWN ACROSS THE WEDGE AREAS THIS EVENING AS TEMPS
RUNNING COOLER THAN EARLIER FORECAST. STILL LOOKS LIKE WARM FRONT
LIFTING NORTH WITH WEDGE BREAKING UNDER THE MODERATE TO HEAVY RAIN
SHOULD CAUSE TEMPS TO STEADY OR SLIGHTLY RISE OVERNIGHT...PER
PREVIOUS FORECAST.
AS FAR AS SVR THREAT FORECAST EFFECTIVE SHEAR AND CAPE SUGGEST
THAT OUR CWA WILL BE OUTSIDE THE WIND THREAT...THOUGH SOME HIGHER
GUSTS COULD OCCUR AROUND MIDNIGHT SOUTH OF THE DAN/SOUTH BOSTON
AREA.
PREVIOUS VALID DISCUSSION...
WIND ADVISORY REMAINS IN EFFECT FOR THE COUNTIES OF TAZEWELL AND
SMYTH IN VIRGINIA AND MERCER IN WEST VIRGINIA.
BROAD UPPER LEVEL 500H TROUGH WILL ENCOMPASS MUCH OF THE CENTRAL
CONUS FOR MONDAY TO START THE WORKWEEK. A COLD FRONT WILL APPROACH
FROM THE WEST MONDAY. A WARM SECTOR SOUTHERLY WINDS WILL RESULT IN A
BREEZY MILD MONDAY. 1000-500MB THICKNESS VALUES OF 565-570DM AND
850H TEMPERATURES AROUND PLUS 10C SUPPORT SURFACE TEMPERATURES FROM
AROUND 60 DEGREES IN THE MOUNTAINS TO THE LOWER 70S IN THE PIEDMONT.
THE SURFACE COLD FRONT CROSSES THE MOUNTAINS LATE IN THE DAY... WITH
GFS SOLUTION A LITTLE QUICKER THAN THE NAM/ECMWF.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 338 PM EST SUNDAY...
ON MONDAY NIGHT LOW LEVEL MOISTURE IS BANKED UP AGAINST THE WESTERN
SLOPES OF THE APPALACHIANS. MODELS ERODE LOW LEVEL MOISTURE ON
TUESDAY MORNING.
OVERALL PATTERN THIS TIME FRAME IS FOR SPLIT FLOW WITH AN ACTIVE
NORTHERN STREAM ALONG THE CANADIAN/NORTHERN U.S. BORDER AND SOUTHERN
STREAM THAT HAS A STRONG SHORT WAVE AT THE BASE OF THE TROF OVER THE
LOWER MISSISSIPPI VALLEY BY LATE TUESDAY. EVOLUTION AND TIMING OF
LONG WAVE TROF FROM POSITIVE TILT TO NEGATIVE TILT AND AMOUNT OF
PHASING BETWEEN THE TWO JET STREAMS WILL IMPACT THE RESULTING TRACK
OF THE GULF TO EAST COAST SURFACE LOW AND LOCATION OF THE HEAVIEST
PRECIPITATION. AT THIS TIME SPREAD IN DIFFERENT MODELS IS LARGE.
HIGHEST CONFIDENCE IS WITH THE TIMING BUT MUCH LOWER WITH THE
LOCATION AND TYPE OF PRECIPITATION. WILL BE LEANING TOWARD BLEND OF
THE ECMWF AND GFS AS SUGGESTED BY WPC.
MODELS SHOW MID ATLANTIC REGION IN THE RIGHT REAR QUADRANT OF A 170
KNOT UPPER JET BY LATE TUESDAY NIGHT. AT THE SURFACE THE COLD FRONT
MOVES OFF THE EAST COAST MONDAY NIGHT THEN HIGH PRESSURE BUILDS FROM
THE TENNESSEE VALLEY INTO THE MID ATLANTIC STATES ON TUESDAY. LOW
PRESSURE DEVELOPS IN THE GULF OF MEXICO ON TUESDAY...THEN TRACKS
ACROSS FLORIDA TUESDAY NIGHT. THE LOW SHOULD BE OFF THE SOUTH
CAROLINA COAST ON WEDNESDAY MORNING AS IT MOVES NORTHEAST AND BEGINS
TO DEEPEN.
ONCE THE LOCATION OF THE PRECIPITATION IS DETERMINED...TEMPERATURES
WILL INFLUENCE WHAT TYPE OF PRECIPITATION WILL OCCUR. EVEN TAKING THE
COOLER MET/SREF GUIDANCE FOR TEMPERATURES ON TUESDAY NIGHT AND
WEDNESDAY...SURFACE VALUES MAY STILL BE TOO WARM EAST OF THE BLUE
RIDGE TO SUPPORT ANYTHING BUT RAIN. HAVE USED PARTIAL THICKNESS
VALUES...MAINLY FROM THE GFS/ECMWF TO PLACE RAIN/SNOW LINE. THIS
WILL CHANGE AS THE EVENT DRAWS CLOSER.
LOOKED AT PROBABILITY FOR SNOW AND CORRELATION WITH PAST ANALOG
EVENTS. APPEARS THERE IS AT LEAST THE POTENTIAL FOR SOME WINTER
PRECIPITATION. SINCE WEDNESDAY IS A MAJOR TRAVEL DAY WILL MENTION
POTENTIAL FOR WINTER PRECIPITATION IN THE HAZARDOUS WEATHER
OUTLOOK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 130 PM EST SUNDAY...
THIS PORTION OF THE FORECAST STARTS WITH THE AFTERMATH OF WHAT
UNFOLDS TUESDAY NIGHT INTO WEDNESDAY EVENING. GIVEN THERE STILL IS
GENEROUS UNCERTAINTY IN THOSE EVENTS...THE EVENTS AFTERWARDS ARE
EQUALLY CHALLENGING. THE GENERAL CONSENSUS IS FOR A LOW/TROUGH TO
DEEPEN ACROSS THE GREAT LAKES/OHIO VALLEY AS THE SYSTEM ALONG THE
COAST HEADS NORTHEAST...AND MAKES WAY FOR THE UPSTREAM SYSTEM TO
ENTER OUR REGION. THE PAST FEW DAYS...GUIDANCE HAS TRANSITIONED THIS
SYSTEM FROM A SLOWER...MORE AMPLIFIED SYSTEM INTO ONE THAT IS MORE
PROGRESSIVE AND THE BULK OF ITS ENERGY REMAINS NORTH OF THE REGION
AS IT MOVES EASTWARD. THAT TREND CONTINUES TODAY. OUR FORECAST WILL
REFLECT LITTLE CHANGE FROM THE PRIOR DURING THE THURSDAY THROUGH
FRIDAY TIMEFRAME. THE HIGHLIGHTS HERE ARE UPSLOPE RAIN/SNOW SHOWERS
ACROSS SOUTHEAST WEST VIRGINIA AND NEIGHBORING COUNTIES OF SOUTHWEST
VIRGINIA. A DECENT NORTHWEST FLOW WILL HELP CLOUDS TO A MINIMUM EAST
OF THE CREST OF THE BLUE RIDGE AND ADD A TOUCH OF A WARMING
INFLUENCE. PARTLY TO MOSTLY CLOUDY SKIES AND COOLER TEMPERATURES
WILL BE THE RULE FOR THE MOUNTAINS.
SATURDAY INTO SUNDAY THE REGION TRANSITIONS INTO MORE OF A ZONAL
PATTERN. THERE IS CONSISTENCY IN EACH MODEL CONCERNING THAT FEATURE.
WHAT VARIES SIGNIFICANTLY IS THE TIMING...TRACK AND SPEED OF A
DISTURBANCE MOVING WITHIN THIS ZONAL FLOW THAT MAY OR MAY NOT IMPACT
OUR REGION. AT THIS TIME...HAVE PLACED THE GREATEST FORECAST WEIGHT
ON A MODEL CONSENSUS THAT OFFERS A SMALL CHANCE OF LIGHT RAIN/SNOW
MAINLY IN THE WESTERN PARTS OF THE AREA SATURDAY NIGHT INTO EARLY
SUNDAY WITH TEMPERATURES TRENDING MILDER OVER THE WEEKEND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 650 PM EST SUNDAY...
WINDS...RAIN AND CLOUDS WILL HINDER AVIATION OPERATIONS
THROUGH THE MORNING MONDAY.
CIGS WILL BE VARIABLE IN THE IFR/MVFR RANGE WITH LIGHT TO MODERATE
RAIN EXPECTED THIS EVENING INTO EARLY OVERNIGHT. THINK THE DECENT
RAIN WILL BE EXITING AFTER MIDNIGHT IN THE WESTERN TAF
SITES/BLF/LWB...AND LYH/DAN AFTER 07Z. WITH IN SITU WEDGE IN PLACE
EARLY THIS EVENING AND STRONG LLJ...WILL SEE A PERIOD OF LOW LVL
WIND SHEAR WHICH ENDS AFTER MIDNIGHT...AT ALL SITES.
OVERNIGHT...MAIN ISSUE WILL BE WHETHER LEFTOVER MOISTURE CAN LEAD
TO FOG...BUT THINK WITH SOUTH TO SSW WINDS APPEARING TO STAY UP
WILL BE LIMITED IN FOG DEVELOPMENT. WILL KEEP CIGS MVFR THOUGH
OVER MUCH OF THE NIGHT THOUGH SEEING DRY SLOT INTO AL/GA MAY BRING
VFR CIGS OR EVEN SCATTERING THEM OUT IN BLF BY DAWN.
SW WINDS AHEAD OF THE COLD FRONT TO KEEP VFR AT ALL TAF SITES BY
LATE MONDAY MORNING. THE ISSUE WILL BE THE WINDS WITH 10-15 KT
SUSTAINED GUSTING TO 20-30 KNOTS AT TIMES.
WIND WILL TURN MORE WESTERLY LATE IN THE TAF PERIOD BUT LEFT THAT
OUT FOR NOW IN THE TAFS GIVEN SUCH AN ACTIVE FIRST 12-18 HOURS.
CONFIDENCE FOR SUB VFR THROUGH TONIGHT IS HIGH...BUT LOW ON TIMING
OF IFR VS MVFR WITH RESPECT TO CIG/VSBY...AGAIN FLUCTUATIONS WILL
OCCUR BASED ON RAINFALL INTENSITY.
CONFIDENCE IS HIGHER MONDAY WITH RETURN TO VFR MOST
LOCATIONS...WITH A SMALL WINDOW IN THE MORNING OF MVFR.
EXTENDED DISCUSSION...
WINDS WILL STAY GUSTY MONDAY NIGHT BEHIND COLD FRONT....WITH
POTENTIAL FOR SUB VFR CIGS IN THE MTNS...WHILE VFR IS EXPECTED TO
THE EAST. ANOTHER STORM SYSTEM IS EXPECTED TO MOVE UP THE
SOUTHEAST COAST BY EARLY WEDNESDAY WHICH MAY BRING WINTRY PRECIP
TO THE AREA ALONG WITH SUB VFR AT ALL SITES. LOOKS LIKE FLIGHTS
WILL BE IMPACTED GREATLY ACROSS THE MID ATLANTIC INTO THE
NORTHEAST WITH THIS SYSTEM WITH STRONG WINDS EXPECTED ALONG WITH
WIDESPREAD PRECIPITATION. AROUND HERE LOOKS LIKE WE WILL
EXPERIENCE SUB VFR AT LEAST WED INTO EARLY THANKSGIVING BEFORE
HIGH PRESSURE WORKS IN FROM THE WEST...THOUGH WINDS MAY STAY UP
THROUGH THU NIGHT...WITH UPSLOPE LOWER CIGS AT BLF/LWB.
&&
.EQUIPMENT...
AS OF 215 PM EST FRIDAY...
THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT
OF SERVICE UNTIL PARTS ARRIVE TO REPLACE THE SENSOR. UNTIL THEN
THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS
STAFFED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR VAZ007-009.
NC...NONE.
WV...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR WVZ042.
&&
$$
SYNOPSIS...KK/MBS
NEAR TERM...KK/WP
SHORT TERM...AMS
LONG TERM...DS
AVIATION...KK/WP
EQUIPMENT...RAB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
555 PM CST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
COMPLEX SHORT TERM PERIOD WITH MANY ISSUES TO DEAL WITH.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A VERY ACTIVE PATTERN OVER THE WEST HALF OF THE COUNTRY.
UPPER LOWS WERE PRESENT OVER NORTHERN MISSISSIPPI AND NORTH
DAKOTA...WHILE POTENT SHORTWAVES WERE NOTED IN SOUTHWEST OKLAHOMA...
NORTHERN NEW MEXICO AND OVER WASHINGTON STATE. THE FORECAST AREA
LIES IN SOUTHWEST FLOW...WHERE WATER VAPOR IMAGERY SHOWS A NICE WARM
CONVEYOR BELT OVER THE EAST HALF OF THE AREA. THIS TRANSLATES TO A
BAND OF RAIN FROM EASTERN IA THROUGH SOUTHWEST WI TO THE GRB AREA.
RAP PRECIPITABLE WATER VALUES ARE AROUND 1 INCH ALONG AND SOUTH OF
THE BAND...COMPARED TO 0.75 INCHES OVER OUR NORTHWEST CWA WHERE
CONDITIONS ARE DRY. ALTHOUGH ITS DRIER IN PRECIPITABLE WATER...
DRIZZLE AND/OR LIGHT RAIN HAS BEEN PRESENT DUE TO SATURATED LOW
LEVELS AND WEAK ISENTROPIC LIFT ON THE 285-290K SURFACES. TO THE
WEST...A COLD FRONT WAS PRESENT ALONG I-35 WITH A WEAKENING BAND OF
RAIN RIGHT BEHIND IT...ASSOCIATED WITH MID LEVEL FRONTOGENESIS.
TEMPERATURES AHEAD OF THE FRONT ACROSS THE FORECAST AREA WERE MAINLY
IN THE 40S TO LOW 50S...COLDEST OVER THE DEEPER SNOWPACK IN TAYLOR
COUNTY. IN THE WAKE OF THE FRONT...READINGS WERE IN THE 30S AND
40S...UNTIL ONE GETS INTO NORTH DAKOTA BEHIND A SECONDARY COLD FRONT
WHERE READINGS ARE IN THE TEENS AND 20S. LAST ITEM OF NOTE IS THE
SEA LEVEL PRESSURE MAP WHERE A LOW EXISTS NEAR MEMPHIS ON THE NORTH
SIDE OF THE UPPER LOW THERE...ANOTHER LOW WAS OVER NORTHERN MN
AHEAD OF THE NORTH DAKOTA UPPER LOW...AND FINALLY A THIRD LOW WAS
OVER NORTHEAST OKLAHOMA AHEAD OF THE POTENT SHORTWAVES.
MODEL WISE...THERE ARE STILL SOME DIFFERENCES THAT HAVE SIGNIFICANT
FORECAST IMPLICATIONS. MUCH OF THE DIFFERENCES WE HAVE SEEN LATELY
THAT CONTINUE INTO TODAY REVOLVE AROUND HANDLING THOSE POTENT
SHORTWAVES IN SOUTHWEST OKLAHOMA AND NORTHERN NEW MEXICO. THE
STRONGER SURFACE LOW SCENARIOS THAT WOULD IMPACT THE FORECAST AREA
WITH MORE SNOW...LIKE OBSERVED IN THE 23.00Z NAM...BROUGHT THESE
SHORTWAVES INTO NORTHERN IL BY 12Z MONDAY. THOSE SHORTWAVE TRACKS
ALSO SHOWED IN A COUPLED UPPER JET STRUCTURE WITH ANOTHER JET STREAK
OVER ONTARIO AND LAKE SUPERIOR. HOWEVER...THE 23.12Z
NAM/GFS/CANADIAN/ECMWF SUGGEST THESE SHORTWAVES WILL TRACK THROUGH
CENTRAL IL. SO WHAT HAPPENS INSTEAD IS A DOUBLE SURFACE LOW...ONE
ASSOCIATED WITH THE NORTHERN MISSISSIPPI UPPER LOW LIFTING THROUGH
LOWER MI AND A SECOND LOW LIFTING TROUGH NORTHERN IL AT 12Z MONDAY.
WITH THE POTENT SHORTWAVES. THERE STILL ARE THE 2 JET STREAKS...BUT
THEY ARE FAR ENOUGH APART TO PREVENT COUPLING AND THUS PREVENTING A
SINGLE SURFACE LOW. THIS FORECAST LEANS TOWARDS THIS NEWER MODEL
GROUP. EVEN THIS GROUP HAS DIFFERENCES...PRIMARILY WITH THE CANADIAN
PRODUCING A LOT MORE SNOW ON MONDAY AROUND AND EAST OF THE
MISSISSIPPI RIVER.
FOR TONIGHT...THE WARM CONVEYOR BELT / FRONTOGENESIS BAND PRODUCING
THE ONGOING RAIN OVER THE SOUTHEAST HALF OF THE FORECAST AREA
REMAINS POISED TO SHIFT EASTWARD THROUGH THE EVENING. THIS EASTWARD
MOVEMENT IS DUE TO THE UPPER AND SURFACE LOWS NEAR THE MEMPHIS AREA
LIFTING INTO LOWER MICHIGAN. HOWEVER...DRIZZLE AND/OR LIGHT RAIN
SHOULD CONTINUE ELSEWHERE AS SOUNDINGS DEPICT PLENTIFUL LOW TO MID
LEVEL VERTICAL MOTION AND SATURATION...SIMILAR TO WHAT IS GOING ON
NOW. ADDITIONALLY...THAT WEAKENING BAND OF MID-LEVEL FRONTOGENESIS
SEEN ALONG I-35 IS POISED TO GRADUALLY CROSS THE FORECAST AREA WITH
THE SURFACE COLD FRONT...AIDING IN PRECIPITATION GENERATION. IT MAY
NOT BE UNTIL 09Z FOR THE FAR WESTERN FORECAST AREA TO SEE AN END TO
THE PRECIPITATION. NOTE THE TYPE SHOULD BEGIN TO CHANGE OVER TO SNOW
AS COLDER AIR IN THE DAKOTAS GETS PULLED INTO THE FORECAST AREA. ANY
ACCUMULATIONS TONIGHT SHOULD BE VERY LIGHT...DUE TO LATE CHANGE-OVER
TIME AND WARM GROUND...AND CONFINED TO MOSTLY WEST OF THE
MISSISSIPPI RIVER.
FOR MONDAY...ATTENTION FOCUSES ON THE LOW AND POTENT SHORTWAVES
LIFTING THROUGH ILLINOIS AT 12Z MONDAY. THERE IS A STRONG CONSENSUS
FOR PRECIPITATION IN THE WAKE OF THE LOW...CORRELATED WITH A LEFT
EXIT REGION OF A JET STREAK COMING INTO THE OHIO VALLEY.
ADDITIONALLY...A STRONG POCKET OF MID LEVEL FRONTOGENESIS WITH
NEGATIVE EPV ABOVE FOLLOWS IN THE WAKE OF THE LOW. THAT
FRONTOGENESIS STRENGTHENS AS THE COLD AIR FROM THE DAKOTAS MEETS UP
WITH THE POTENT SHORTWAVES LIFTING NORTHEASTWARD...ALSO CAUSING A
SWITCHOVER TO SNOW. CONSENSUS...OUTSIDE OF THE CANADIAN...SUGGESTS
THE HEAVIER SNOW TRACKING THROUGH NORTHERN IL AND SOUTHERN
WI...CLIPPING GRANT AND RICHLAND COUNTIES...POSSIBLY JUNEAU AND
ADAMS TOO. BOTH SNOWFALL AMOUNTS AND BLOWING POTENTIAL ARE GOING TO
BE KEPT DOWN QUITE A BIT WITH SOUNDINGS DEPICTING A DEEP AGGREGATION
LAYER AND ONLY 50 MB OR SO OF DENDRITIC GROWTH ZONE. ADDITIONALLY...
WARM GROUND AND LACK OF SNOW WILL HELP LIMIT BLOWING. IN
COLLABORATION WITH MKX AND DVN...HAVE ISSUED A WINTER WEATHER
ADVISORY FOR GRANT AND RICHLAND. ELSEWHERE...THERE SHOULD STILL BE
SOME LIGHTER SNOW WITH A WEAKER MID LEVEL FRONTOGENESIS ZONE
MARCHING WEST TO EAST...AND DEEP SATURATION. AMOUNTS DO NOT WARRANT
AN ADVISORY ELSEWHERE AT THIS TIME.
IN THE FOG DEPARTMENT...CONDITIONS HAVE YET TO IMPROVE ACROSS
TAYLOR/CLARK COUNTIES. HI RES MODEL VISIBILITY PROGS...WHICH
ARE HANDLING THE FOG THERE WELL...DO NOT SHOW ANY CLEARING UP UNTIL
THE 06-09Z PERIOD WHEN WINDS START TO INCREASE. THEREFORE...HAVE
EXTENDED THE ADVISORY UNTIL 06Z. VISIBILITIES HAVE ALSO BEEN LOW
OVER THE FAR WESTERN FORECAST AREA...THOUGH THESE SHOULD IMPROVE
SOON AS THE WINDS PICK UP. WILL NEED TO KEEP AN EYE ON VISIBILITIES
THROUGH NORTHEAST IOWA AND SOUTHWEST/CENTRAL WI AS THE HEAVIER RAIN
MOVES OUT...WITH SOME SIGNAL THEY COULD DROP TO WARRANT AN ADVISORY.
LASTLY...REGARDING WINDS...SHOULD SEE SUSTAINED SPEEDS OF 15-30 MPH
WITH GUSTS MAYBE UP TO 40 MPH ON MONDAY. DO NOT SEE ANY WIND
ADVISORY NEED AT THIS TIME...THOUGH. THESE NORTHWEST WINDS WILL
RESULT IN A FALLING TEMPERATURE TREND FROM NOW THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
NO MATTER WHAT SOLUTION PANS OUT FOR MONDAY...THE TREND CONTINUES TO
BE FOR SNOW TO DIMINISH MONDAY NIGHT AS THE ENTIRE STORM SYSTEM
EXITS EASTWARD INTO QUEBEC. THERE IS SOME UNCERTAINTY ON HOW QUICK
THE SNOW EXITS...MAINLY DUE TO ONE MORE WEAK SHORTWAVE PASSING. WITH
STRATUS LINGERING IN THE DENDRITIC GROWTH ZONE...IT MAKES SENSE TO
CONTINUE TO CARRY PRECIPITATION CHANCES LONGER TOO THAN WHAT MODEL
QPF WOULD SAY FOR ENDING SNOW. BETTER CHANCE FOR CLEARING COMES IN
TUESDAY AS A SURGE OF DRIER...SUBSIDENT AIR COMES IN AHEAD OF A
SURFACE LOW AND SHORTWAVE DROPPING THROUGH THE DAKOTAS. IN FACT...WE
SHOULD GET INTO A WARM ADVECTION REGIME LATER IN THE DAY TO ALLOW
TEMPERATURES TO CLIMB INTO THE MID TO UPPER 20S.
THE SHORTWAVE TROUGH AND SURFACE LOW DROPPING THROUGH THE DAKOTAS
FOR TUESDAY NIGHT AND WEDNESDAY HAS BEEN TRENDING SOUTHWARD IN THE
23.12Z ECMWF...FOLLOWING THE 23.06Z/12Z GFS/NAM. THE 23.12Z CANADIAN
IS ABOUT THE ONLY MODEL NOW WITH THE MORE NORTHERN TRACK. HAVE
ADJUSTED THE FORECAST FOR A MORE SOUTHERN TRACK. DPVA PLUS A SURGE
OF WARM AIR ADVECTION LOOKS TO RESULTS IN A BRIEF BUT HEAVY SNOW
BAND AHEAD OF THE SURFACE LOW. WITH THE SOUTHERN TREND BUT OVERALL
GOOD CONSENSUS TO HAVE THE SNOW BAND...RAISED CHANCES ON WEDNESDAY
TO 60 ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA. MAY GET A
QUICK 1-2 INCHES OUT OF THE BAND...ENOUGH TO IMPACT TRAVEL.
A DRIER BUT COLDER FORECAST IS ON TAP FOR WEDNESDAY NIGHT AND
THANKSGIVING AS ARCTIC HIGH PRESSURE BUILDS INTO THE REGION. 925MB
TEMPS DOWN TO -12 TO -16C SHOULD RESULT IN HIGHS IN THE TEENS TO
MAYBE 20 AT BEST.
THE FORECAST AFTER THANKSGIVING BECAME MUCH MORE UNCERTAIN
TODAY. THERE ARE NOW INDICATIONS OF MORE TROUGHING DIGGING DOWN
THROUGH BRITISH COLUMBIA...WHICH HELPS TO TURN THE UPPER FLOW MORE
ZONAL...AND THUS SEND A WARMER PACIFIC AIRMASS TOWARDS US.
ADDITIONALLY...A WARM FRONT LOOKS TO MOVE THROUGH THE AREA ON
FRIDAY...WHICH COULD PRODUCE A LITTLE SNOW. NOW...THE 23.12Z
GFS/CANADIAN DRIVE A SHORTWAVE THROUGH THE REGION FRIDAY NIGHT AND
ALLOWS ARCTIC AIR TO RETURN FOR THE WEEKEND. THE 23.12Z ECMWF ALLOWS
THIS SHORTWAVE TO STAY FARTHER NORTH...KEEPING THE AREA IN THE WARM
SECTOR. FOR NOW...HAVE STAYED WITH THE CONSENSUS PRIOR TO THE NEW
ECMWF ARRIVAL...BUT THE WEEKEND TEMPS ARE DEFINITELY SUBJECT TO
CHANGE GREATLY. GENERALLY THE WEEKEND LOOKS DRY...THOUGH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 555 PM CST SUN NOV 23 2014
COMPLEXITIES - AND THUS CHALLENGES - REMAIN WHEN IT COMES TO VSBY
AND CIGS HEIGHTS. OVERALL...THE PERIOD OF IFR/MVFR CIGS AND VSBYS
SHOULD CONTINUE THROUGH SUNDAY...ALTHOUGH EXPECT A PERIOD OF
IMPROVEMENT IN VSBYS ON MONDAY.
AN AREA OF LOW PRESSURE WILL SLIDE SOUTH OF THE TAF SITES
TONIGHT...MOVING ACROSS THE EASTERN GREAT LAKES. A SFC FRONT HAS
MOVED EAST OF KRST ALREADY...AND WILL DO SO AT KLSE OVER THE NEXT
COUPLE HOURS. WINDS INCREASE SIGNIFICANTLY POST THE FRONT...AND WILL
STAY STRONG THROUGH MONDAY. EXPECT SOME GUSTINESS TOO.
WITH LOW SATURATION ABUNDANT...ANTICIPATE MOSTLY SUB 1 KFT CIGS
THROUGH THE NIGHT...WITH SOME SLIGHT IMPROVEMENT ON MONDAY. VSBYS
WILL BE VARIABLE DEPENDING ON WHEN ITS PRECIPITATING. GOOD LIFT
THROUGH THE NIGHT...AND RA/DZ SHOULD PERSIST. COLD AIR POST THE
FRONT THOUGH...AND THERE SHOULD BE A CHANGE OVER TO -SN OVERNIGHT.
ONE CAVEAT IS THAT RAP/HRRR/NAM BUFKIT SOUNDINGS ALL SHOWING A
POTENTIAL LOSS OF ICE AT KRST - WHICH WOULD MEAN FZDZ RATHER THAN
SN. ITS CLOSE AND WILL HAVE TO BE MONITORED. WILL STICK WITH -SN FOR
NOW.
LOOKING FOR SOME IMPROVEMENT IN VSBYS RELATED TO PCPN AS THE LOW
MOVES OFF EARLY MONDAY. HOWEVER...A BIT OF UPPER LEVEL ENERGY A LOFT
AND A SFC TROUGH WILL SWING BACK ACROSS THE REGION MONDAY
AFTERNOON/EVENING. THIS SHOULD BRING ANOTHER AREA OF SNOW...WITH
LIKELY MVFR/IFR VSBYS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 6 AM MONDAY TO MIDNIGHT CST MONDAY
NIGHT FOR WIZ055-061.
DENSE FOG ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
324 PM CST SAT NOV 22 2014
.SHORT TERM...
TONIGHT...FORECAST CONFIDENCE MEDIUM.
MAIN CONCERN WILL BE ON TIMING OF PRECIP AND HANDLING FOG TRENDS.
MILD AND MOIST FLOW WILL PERSIST ALL NIGHT. ISODROSOTHERM ANALYSIS
SHOWS THE MOIST AXIS POINTING RIGHT INTO SRN WI WITH A GRADUAL
ADVECTION PATTERN NOTED. MID LEVEL ACROSS HERE IS ZONAL WITH THE
MAIN UPPER LOW WELL SOUTH IN TX. LOWS WILL BE ESTABLISHED EARLY
THIS EVENING WITH POSITIVE TEMP ADVECTION LIKELY FOR MUCH OF THE
NIGHT. GUIDANCE HAS BEEN SENDING MIXED SIGNALS ON HOW DENSE FOG
GETS TONIGHT. WINDS INCREASE OFF THE DECK AND THAT MAY LIMIT
THINGS FROM GETTING OUT OF HAND IN A WIDESPREAD FASHION.
NEVERTHELESS EXPECT IT TO REMAIN FOGGY BUT WILL ELECT TO NOT ISSUE
A HEADLINE AT THIS TIME. OVERALL LOOKS CLOUDY...MILD...FOGGY WITH
SOME DRIZZLE AND PERHAPS A FEW SHOWERS. LATEST HRRR BRINGS A BAND
OF SHRA THROUGH HERE IN THE 03-07Z RANGE BUT THEN NOT MUCH AFTER
THAT THROUGH 12Z.
SUNDAY...FORECAST CONFIDENCE MEDIUM.
GRADUAL PROGRESSION AND AMPLIFICATION OF WESTERN TROUGH. THIS
KEEPS SRN WI IN A BROAD SSW UPPER FLOW. SHORTWAVE ACTION IN THIS
FLOW INCREASES ESP AFTER 18Z. WILL HAVE DEFINITE POPS. THERMAL
PROFILE SUPPORTS RAIN CWA WIDE. CLOUDS/RAIN WILL LIMIT TEMPS BUT
STILL EXPECT ENOUGH TEMP ADVECTION TO REACH AT LEAST THE LOW 50S
IN MANY LOCALES.
SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM.
STRONG CYCLOGENESIS IS EXPECTED FROM SW IL TO FAR ERN UPPER MI...AS
A SHORTWAVE TROUGH MOVES NORTH THROUGH THE GREAT LAKES AND A LARGER
SCALE UPPER TROUGH APPROACHES FROM THE PLAINS. A CONSENSUS OF
MODELS DEEPEN THE LOW TO 980 MB BY 12Z MON OVER FAR ERN UPPER MI
AND TAKE IT TO THE ONTARIO AND QUEBEC BORDER BY 00Z TUE. THE UPPER
WAVE AND WARM CONVEYOR BELT WILL BRING PWS OF ONE INCH AND
WIDESPREAD MDT RAINFALL SUN NT. RAINFALL FORECAST FOR SUN AFT
THROUGH THE NIGHT IS AROUND 1 INCH. 850-700 MB FRONTOGENESIS WILL
BE ON THE TRAILING END OF THE SYSTEM FOR MON AND MON NT AS THE
LARGE UPPER TROUGH SLOWLY MOVES ACROSS THE AREA. THUS EXPECT SOME
LIGHT SNOW ACCUM AS THE CHANGE TO SNOW OCCURS FROM WEST TO EAST
MON AM AND THE SNOW CONTINUES MON NT. ANY LINGERING LGT SNOW WILL
COME TO AN END TUE AM WITH POLAR HIGH PRESSURE BUILDING INTO WI
FOR THE AFT AND NIGHT. SFC TEMPS TO DROP THROUGHOUT THE DAY ON
MON ON BRISK WLY WINDS AND COLD ADVECTION. WELL BELOW NORMAL TEMPS
THEN RETURN FOR THE NEW WEEK.
.LONG TERM...WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE
MEDIUM.
A COUPLE SHORTWAVE TROUGHS WILL DIG SEWD FROM CANADA INTO THE
REGION FOR WED-THU AND ESTABLISH NW FLOW ALOFT FOR THE REMAINDER
OF THE WEEK. SFC LOW PRESSURE AND CHANCES OF LIGHT SNOW WILL
ACCOMPANY THE UPPER WAVES BUT THE TIMING IS UNCERTAIN. LIGHT SNOW
ACCUM IS LIKELY HOWEVER. VERY COLD TEMPS WILL CONTINUE DURING THIS
PERIOD.
&&
.AVIATION/00Z TAFS/...MAIN CONCERN WILL BE STRATUS/FOG TRENDS WITHIN
THE MILD AND MOIST REGIME THAT LASTS RIGHT INTO SUNDAY. PLENTY OF
WIND TAKES SHAPE UPSTAIRS WHICH RESULTS IN SOME LLWS CONDITIONS
OVERNIGHT. ATTM BELIEVE THIS WILL KEEP THE FOG FROM GETTING
PERSISTENTLY DENSE. BUT WILL HAVE SOME DENSE FOG POCKETS ACROSS THE
CWA...BUT CONFIDENCE LOW ON WIDESPREAD AT THIS TIME. LIFR CEILINGS
WILL PERSIST INTO SUNDAY AS RAIN BECOMES WIDESPREAD. THIS MAY HELP
TO FURTHER MIX VSBYS A BIT BUT STILL EXPECT IFR VSBYS WITH A FEW
LIFR VSBYS IN ANY DENSE FOG POCKETS.
&&
.MARINE...STILL LOOKING AT POTENTIAL FOR SOME HIGHER WAVES OFFSHORE
FROM SHEBOYGAN TOWARDS OPEN WATERS...SO WILL LET THE SMALL CRAFT GO
TIL THE 00Z END TIME THERE. NEXT CONCERN WILL BE INCREASING WINDS
FOR SUNDAY AND SUNDAY EVENING. APPEARS BORDERLINE SMALL CRAFT ATTM
AS SURFACE LOW MOVES INTO SRN IL BY 00Z. A SSE WIND DEVELOPS BUT
EXPECT WAVES/WINDS TO REMAIN JUST BELOW CRITERIA. MAIN CONCERN WILL
BE ONCE THE LOW STRENGTHENS AND LIFTS NORTH OF THE AREA MONDAY INTO
MONDAY EVENING. RATHER GUSTY WEST WINDS DEVELOP AND BUFKIT SOUNDINGS
SUPPORT SOME GALE CONDITIONS IN THIS REGIME. SO HAVE HOISTED A GALE
WATCH FROM MID MORNING MONDAY THOUGH MIDNIGHT MONDAY NIGHT. HIGHEST
WAVES TOWARDS OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR
LMZ643>646.
SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR LMZ643.
&&
$$
TONIGHT/SUNDAY AND AVIATION/MARINE...COLLAR
SUNDAY NIGHT THROUGH SATURDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
313 PM CST SAT NOV 22 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 313 PM CST SAT NOV 22 2014
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POWERFUL TROUGH OVER THE PACIFIC NORTHWEST...NOTED
BY A 155 KT JET NEAR 300MB ON THE 12Z MEDFORD OREGON RAOB. OTHER
FEATURES OF NOTE WERE AN UPPER LOW OVER THE BIG BEND REGION OF TEXAS
AND AN UPPER RIDGE OVER THE DAKOTAS AND MN. BELOW THE UPPER
RIDGE...WEST TO SOUTHWEST WINDS OF 20-30 KT FROM 925-850MB PER
PROFILER/VWP DATA HAS BEEN ADVECTING WARMER AIR INTO THE REGION.
925MB TEMPS HAVE RISEN FROM -1 TO 2C AT 12Z TO 2-6C AT 21Z.
HOWEVER...TAMDAR SOUNDINGS SHOW MUCH OF THIS WARMING HAS BEEN
STRENGTHENING A STRONG LOW LEVEL INVERSION...TRAPPING MOISTURE
ADVECTING NORTHWARD ON SOUTHERLY WINDS. DEWPOINTS PRESENTLY RANGE IN
THE 30S TO LOW 40S ACROSS THE FORECAST AREA...BUT 40S TO MID 50S
WERE LURKING ACROSS CENTRAL AND SOUTHERN IOWA. THE INCREASED
WARMING AND MOISTURE AT THE SURFACE HAS ALSO ALLOWED THE SNOWPACK TO
BEGIN TO WARM AND MELT...ADDING ADDITIONAL MOISTURE. WE HAVE SEEN
DENSE FOG EARLIER IN THE DAY...BUT DAYTIME MIXING PLUS WARMER AIR
COMING UP FROM THE SOUTH HAS HELPED TO RAISE VISIBILITIES FOR NOW.
FOR TONIGHT...IMPRESSIVE SURFACE TO 925MB WARM AND MOIST AIR
ADVECTION REMAINS PROGGED TO OCCUR ACROSS THE FORECAST AREA...AIDED
BY THE 925MB WINDS INCREASING TO 30-40 KT. 925MB TEMPS AND
DEWPOINTS BY 12Z SUNDAY CLIMB TO 8-10C...WITH MUCH OF THE JUMP
HAPPENING BETWEEN 00-06Z. THESE DEWPOINTS ARE 2-3 STANDARD
DEVIATIONS ABOVE NORMAL. HAD TO DO SOME MAJOR TEMP/DEWPOINT
ADJUSTMENTS TO HANDLE THIS WARM/MOIST AIR ADVECTION...FOLLOWING
MORE OF THE ECMWF/CANADIAN WHICH ARE NOT AFFECTED AS MUCH BY
SNOWPACK LIKE THE NAM IS. WITH ALL OF THIS WARMING AND MOISTURE
COMING ACROSS THE SNOWPACK...ANTICIPATE FAIRLY RAPID MELTING...
THROWING MORE MOISTURE INTO THE BOUNDARY LAYER. GIVEN AN
INVERSION HOLDING IN PLACE BETWEEN 850-900MB THIS EVENING...BELIEVE
WE SHOULD GET MORE FOG TO DEVELOP...POSSIBLY DENSE...SIMILAR TO WHAT
IS GOING ON RIGHT NOW IN SOUTH CENTRAL IA ON I-35 ON THE NOSE OF
THE MOISTURE SURGE. CONSIDERED GOING WITH AN ADVISORY...BUT
AFTERNOON TRENDS HAS REDUCED CONFIDENCE. ADVISORIES ARE STILL
POSSIBLE...THOUGH. OVERNIGHT...ALL THE FOG COULD DISSIPATE AS
THAT INVERSION WEAKENS...AS INDICATED IN RAP/HIRESARW VISIBILITY
FORECASTS. IN FACT...WE SHOULD HAVE THE AIRMASS OVER MISSOURI IN
PLACE WHICH FEATURES NO VISIBILITY RESTRICTION. SINCE THERE STILL
IS SNOWPACK...HAVE KEPT SOME FOG MENTION...BUT WE MAY NOT HAVE
MUCH SNOWPACK EXCEPT IN OUR NORTH BY THE TIME 12Z ROLLS AROUND.
ALONG WITH THE FOG...THE STRONG INCREASE OF LOW LEVEL MOISTURE IS
LIKELY TO LEAD TO AREAS- WIDESPREAD DRIZZLE...ESPECIALLY
OVERNIGHT.
ON SUNDAY...GOOD MODEL CONSENSUS EXISTS FOR DEEP TROUGHING TO FORM
ACROSS THE PLAINS BY 00Z...WHICH HELPS TO PULL NORTHEASTWARD THE
UPPER LOW NEAR TEXAS INTO SOUTHERN ILLINOIS. THE 22.12Z NAM IS THE
ONLY MODEL WHICH DOESNT PULL THE UPPER LOW NORTHEASTWARD...WHICH
APPEARS TO BE AN OUTLIER AND HAS BEEN DISCOUNTED. WITH THE APPROACH
OF BOTH THE UPPER TROUGH AND LOW IN THE AFTERNOON...DPVA FOR
VERTICAL MOTION INCREASES. THIS VERTICAL MOTION COMBINED WITH
PRECIPITABLE WATER CLIMBING TO 0.75-1 INCH...HIGHEST OVER THE
SOUTHEAST HALF OF THE FORECAST AREA...WILL LEAD TO AN INCREASE IN
SHOWER ACTIVITY...ESPECIALLY IN THE AFTERNOON. NOTE THAT THERE ARE
SIGNS FOR A FRONTOGENETIC BAND TO FORM STRETCHING SOUTHWEST TO
NORTHEAST ACROSS THE FORECAST AREA...WHICH MAY LEAD TO LESS
PRECIPITATION OVER THE FAR NORTHWEST SIDE OF THE FORECAST AREA.
OTHERWISE...ANY FOG FROM TONIGHT LOOKS TO DISSIPATE WEST TO EAST
THROUGH THE AFTERNOON...IN RESPONSE TO A COLD FRONT COMING INTO THE
WESTERN FORECAST AREA AND THE RAIN MOVING IN.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 313 PM CST SAT NOV 22 2014
SUNDAY NIGHT AND MONDAY...THIS PERIOD IS BECOMING MORE INTERESTING.
THERE ARE SIGNS IN THE 22.12Z GFS AND CANADIAN OF PHASING TAKING
PLACE...BETWEEN THE OVERALL UPPER TROUGH ACROSS THE PLAINS AND THE
CURRENT STRONG JET STREAK AT MEDFORD OREGON LIFTING INTO THE OHIO
VALLEY. THE GFS EVEN TAKES IT ONCE STEP FURTHER AND PHASES IN THE
TEXAS UPPER LOW. THE RESULT OF THE PHASING IS RAPID DEEPENING OF A
SURFACE LOW BETWEEN 00-12Z MONDAY MARCHING FROM MISSOURI TO NORTHERN
LAKE MICHIGAN. PRESSURES FALL FROM THE UPPER 980S TO LOW 970S OR
UPPER 960S MB. THE 22.09Z SREF NMMB MEMBERS AND SOME OF THE
CANADIAN ENSEMBLES ARE ALSO QUITE DEEP...EVEN MORESO THAN THE
GFS/CANADIAN. THESE DEEPER MODELS WOULD RESULT IN A TROWAL
OVER THE FORECAST AREA...LEADING TO A HEAVY SNOW BAND AND STRONG
WINDS. ALTHOUGH THERE HAS BEEN A TREND OF DEEPENING IN THE
AFOREMENTIONED MODELS...THE 22.12Z ECMWF REMAINS CONSISTENT IN A
MORE PROGRESSIVE/LESS PHASED SCENARIO. THE MODEL STILL HAS SNOW FOR
THE FORECAST AREA AFTER SOME EVENING RAIN...BUT THE F-GEN BAND IS
NOT NEARLY AS IMPRESSIVE. GIVEN THE CONSISTENCY IN THE ECMWF
AND THE MODEL BEING GENERALLY ONE OF THE BEST AT SYNOPTIC
VERIFICATION...FEEL IT IS DIFFICULT TO JUMP ON THE DEEP SCENARIOS
YET. THUS...THE FORECAST FOR SUNDAY NIGHT/MONDAY REMAINS LARGELY
UNCHANGED. DID BACK OFF THE BLOWING SNOW A BIT SINCE THE SNOWPACK
WILL BE GONE...ALLOWING ANY FALLING SNOW TO ACCUMULATE IN DITCHES
AND THUS LIMIT BLOWING. TEMPERATURE WISE...EXPECT A CONTINUOUS
FALLING TREND FROM SUNDAY NIGHT THROUGH MONDAY.
SNOW SHOULD GRADUALLY TAPER OFF MONDAY NIGHT AS THE LOW LIFTS
OFF TO THE NORTHEAST...BUT CONTINUED COLD AIR ADVECTION IS
ADVERTISED. 925MB TEMPS PLUNGE TO -10 TO -12C...WHICH SHOULD BRING
TEMPS DOWN INTO THE TEENS. TUESDAY FINALLY LOOKS LIKE A DRY
DAY...ASSOCIATED WITH SURFACE RIDGING COMING ACROSS AND AHEAD OF A
POTENT SHORTWAVE DROPPING INTO THE DAKOTAS. PRECIPITABLE WATER IS
QUITE DRY TOO...AROUND 0.2 OF AN INCH...WHICH SHOULD ALLOW ANY LOW
CLOUDS TO CLEAR TUESDAY MORNING. MORE HIGH CLOUDS ARE LIKELY TO
ARRIVE IN THE AFTERNOON...THOUGH. WITH 925MB TEMPS OF -8 TO -10C AT
18Z...HIGHS ONLY LOOK TO TOP OUT IN THE 20S.
TUESDAY NIGHT AND WEDNESDAY COULD BE INTERESTING AS WELL WITH THE
22.12Z ECMWF REMAINING CONSISTENT IN DRIVING A STORM SYSTEM
FROM THE DAKOTAS THROUGH THE REGION. THE 22.12Z/18Z NAM ARE SIMILAR
TOO...THOUGH THERE REALLY IS NO RESEMBLANCE OF THE SYSTEM IN THE
22.12Z GFS. THE 22.12Z CANADIAN IS LIKE A WEAKER NAM/ECMWF. SHOULD
THE ECMWF/NAM VERIFY...WE COULD BE LOOKING AT A 1-2 INCH
SNOWFALL...WHICH COULD IMPACT THANKSGIVING TRAVEL. FOR NOW HAVE TO
KEEP THE CHANCES LOWER...20-40...UNTIL BETTER MODEL AGREEMENT OCCURS.
HOWEVER WEDNESDAY PANS OUT...GOOD MODEL AGREEMENT EXISTS FOR ANOTHER
COLD SURGE TO DIVE INTO THE REGION FOR THANKSGIVING. 925MB TEMPS OF
-14 TO -16C ARE PROGGED...WHICH WOULD RESULT IN HIGHS ONLY IN THE
MID TEENS TO LOW 20S AT BEST. THIS COLD AIR LOOKS TO LINGER INTO THE
EARLY PART OF THE WEEKEND AS CANADIAN HIGH PRESSURE BUILDS IN.
GENERALLY CONDITIONS SHOULD BE DRY...THOUGH CANNOT RULE OUT A FEW
LIGHT SNOW PERIODS THAT DO NOT ACCUMULATE UP TO MUCH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1155 AM CST SAT NOV 22 2014
BIG PICTURE OF THIS FORECAST CYCLE FOR THE TAFS WAS ABUNDANT
MOISTURE AND SOUTHERLY WARM FLOW IN THE LOW LEVELS WILL PROMOTE
AN IFR FORECAST THROUGHOUT THE PERIOD. IT IS QUITE LIKELY WE WILL
SEE EXTENDED LIFR CONDITIONS IN THE OVERNIGHT AND MORNING SUNDAY.
WE WILL LIKELY SEE IFR CONDITIONS THROUGH COLD FRONT PASSAGE TIME
WHICH WILL COME SUNDAY NIGHT. HOWEVER...SHOULD SNOW OCCUR...IFR
CONDITIONS ARE EXPECTED SUNDAY NIGHT INTO MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BAUMGARDT
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
329 AM CST Mon Nov 24 2014
.SHORT TERM...(Today)
ISSUED AT 329 AM CST MON NOV 24 2014
Several short-term forecast challenges today, as a potent storm
system tracks through the area. Of particular concern are
strong/gusty winds behind a departing frontal boundary and the
potential for a light accumulation of snow across the W/NW KILX
CWA.
08z/2am surface analysis shows cold front extending from southern
Lake Michigan to the Ozarks. An area of low pressure along the
boundary over southeast Missouri is currently enhancing lift and
triggering a few thunderstorms along/south of the I-70 corridor.
This activity will push E/NE into Indiana by dawn. Further west, an
area of precipitation along/behind the front will continue to lift
northward, mainly impacting locations along/west of I-57. As colder
air streams into the region, the rain will gradually mix with and
change to snow by mid-morning. Based on upstream temp falls across
Iowa/Missouri, readings will drop into the middle 30s across the
Illinois River Valley by 12z/6am, then further east to the I-55
corridor by 15z/9am. At the same time, the precip will be pulling
northeastward out of the area, so there appears to be only a narrow
window of opportunity for snow across the W/NW. Will carry likely
to categorical PoPs across the western half of the CWA for rain
changing to snow this morning, with lower rain chances further east
and south across the remainder of the region. Main area of snow
will lift into northern Illinois by midday, with only a few
flurries/snow-showers persisting along/north of I-72 this
afternoon. Total snow accumulation will be limited due to light QPF
and marginally favorable temps. Around 1 inch is expected
along/north of a Canton to Bloomington-Normal line, with trace
amounts as far southeast as a Litchfield to Champaign-Urbana
line.
Other big story today will be the strong winds behind the cold
front. Upstream obs have already shown gusts as high as 30-40mph
and think these will translate eastward across central Illinois this
morning. Main question will be whether there may be a corridor of
enhanced winds approaching Wind Advisory criteria across the E/SE
CWA. Current MSAS analysis shows max 3-hour pressure rises of 6mb
over southern Missouri/northern Arkansas. Both the 00z and 06z runs
of the NAM have shown these rises tracking northeastward and
increasing to around 9mb over southeast Illinois later this
morning. HRRR 10m wind gust graphic also indicates increasing winds
ahead of the pressure change couplet as it moves across the
southeast CWA between 12z and 18z. Given this consistent signal,
think it is prudent to issue a Wind Advisory for locations
along/southeast of a Champaign to Taylorville line. While all of
central Illinois will experience wind gusts of 30 to 35 mph, this
particular area may see higher gusts exceeding 40 mph.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 329 AM CST MON NOV 24 2014
Low pressure will lift into the Great Lakes tonight, taking the bulk
of the precip with it. Wrap around moisture may brush across the
northern CWA, so have included scattered flurries in the forecast
this evening along/north of I-72. Forecast soundings indicate low
clouds will persist tonight and may even be slow to clear on
Tuesday, despite approaching surface ridge axis. Have therefore
slowed the clearing trend, with cloudy skies tonight followed by
decreasing clouds on Tuesday.
Fast-moving clipper system is still on target for mid-week, with
model consensus bringing the system across central Illinois on
Wednesday. This particular track is slightly further south than
previously advertised, so WAA ahead of the wave may not be quite as
pronounced as once thought. Even still, high temperatures will
climb well into the 30s and into the lower 40s across the southeast
CWA. End result will be light snow across the far north from the
Peoria area northward, a mix of light rain/snow across much of the
area, and mainly rain south of I-70. Due to the limited period of
light precip and warm temps, snow accumulations will be minimal.
Once this system passes to the east, another shot of cold air will
arrive for Thursday. After that, signs are still pointing to warmer
conditions by the end of the week, with temps climbing well into the
40s by Saturday. Both the GFS and ECMWF indicate a cold front will
drop through the region Saturday night, so temps will likely drop
back into the upper 30s/lower 40s by Sunday/Monday. Moisture will
be limited, so will maintain a dry FROPA at this time.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1147 PM CST SUN NOV 23 2014
The pair of surface low centers have merged and lifted to the NE
of our forecast area, with a trailing cold front to the SW across
IL into southeast Missouri. Drizzle, fog and low clouds are
lingering behind the departing low along that trough, with VLIFR
ceilings at BMI, and LIFR ceilings at the remaining TAF sites.
Expect ceilings to improve slightly with the return redevelopment
of showers well behind the low, but remaining LIFR until Monday
afternoon when levels possibly climb all the way to MVFR.
Cold air will filter into central IL late tonight and Monday
morning, causing the rain showers to mix with or change to light
snow from west to east toward 6 am for PIA/SPI, 8 am for BMI, and
10 am for CMI/DEC. As the precipitation becomes all snow, vsbys
could drop below 1 mile at PIA and BMI where snowfall accumulation
could climb up as high as 1 inch. Vsbys should remain 2-4 miles
farther south toward I-72 where snowfall will be lighter. Snowfall
rates will diminish quickly after 18z-19z, with high winds blowing
any snow around and possibly keeping visibility low at times.
Winds have already become SW behind the low. Pressure rises will
climb to 6 mb/3 hours in at least the southeast half of our
forecast area, which would include DEC/CMI. Wind speeds in our
southeast areas could climb as high as 30g40kt between 12z and 15z
this morning, with other areas 25g35kt. Those speeds could
continue into early afternoon, but we should see some decrease in
peak gusts as the afternoon progresses.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 6 PM CST this evening FOR ILZ044>046-052>057-
061>063-066>068-071>073.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
155 AM CST MON NOV 24 2014
.UPDATE...
FOR EVENING UPDATE...
ONLY MINOR ADJUSTMENTS MADE TO GOING FORECAST TONIGHT...PRIMARILY
TO ADD AREAS OF FOG ALONG THE LAKE AND ACROSS PARTS OF NORTHERN
ILLINOIS OVERNIGHT.
COMPLEX UPPER PATTERN CONTINUES TO EVOLVE ACROSS THE REGION THIS
EVENING AS A SERIES OF MID-LEVEL SHORT WAVES ROTATE THROUGH THE
LARGER-SCALE UPPER TROUGH OVER THE CENTRAL AND EASTERN PARTS OF
NORTH AMERICA. AT THE SURFACE...AN AREA OF LOW PRESSURE WITH A
COUPLE OF INDIVIDUAL LOW CENTERS WAS OVER IL AT 02Z/8 PM CST...
WITH STRONG (6 MB/3 HRS) SURFACE PRESSURE FALLS ACROSS MUCH OF THE
MIDWEST AND SOUTHERN GREAT LAKES REGION. THE LATEST MODEL GUIDANCE
CONTINUES TO CONSOLIDATE A SURFACE LOW OVER FAR NORTHEAST IL OVER
THE NEXT SEVERAL HOURS...LIFTING IT NORTHEAST AND DEEPENING IT
OVERNIGHT AND EARLY MONDAY AS IT PULLS AWAY FROM THE AREA.
REGIONAL RADAR MOSAICS INDICATE A LARGE SHIELD OF RAIN ACROSS THE
EASTERN HALF OF ILLINOIS AND MUCH OF THE GREAT LAKES REGION
PRIMARILY ASSOCIATED WITH A STRONG SHORT WAVE LIFTING NORTHEAST
CROSS THE OHIO VALLEY. ANOTHER AREA OF RAIN AND EMBEDDED THUNDER
WS NOTED BACK ACROSS THE LOWER MISSOURI VALLEY WITH ANOTHER STRONG
WAVE. RAIN MAY TAPER OFF TO OCCASIONAL LIGHT RAIN OR DRIZZLE
ACROSS SOME AREAS WITH A BIT OF A BREAK BETWEEN THE SOLID RAIN
WITH THESE SYSTEMS...THOUGH A PERSISTENT DRIZZLE WILL LIKELY MAKE
IT SEEM LIKE ITS RAINING MOST OF THE TIME ANYWAYS. IN ADDITION TO
THE RAIN...HIGH DEWPOINT AIR WRAPPING NORTHWESTWARD AHEAD OF THE
SURFACE LOW WAS PRODUCING FOG ACROSS SOUTHERN LAKE MICHIGAN WHERE
LAKE WATER TEMPS WERE IN THE MID-40S...AND AFFECTING AREAS ALONG
THE ILLINOIS SHORE. WILL ALSO LIKELY SEE SOME PATCHES OF FOG WHERE
PRECIP DIMINISHES TO DRIZZLE OVERNIGHT...ESPECIALLY IN BAGGY
PRESSURE GRADIENT AND WEAKER WINDS IN VICINITY OF THE SURFACE LOW.
WEST WINDS WILL KICK IN EARLY MONDAY MORNING AS THE LOW PULLS
NORTH AND A COLD FRONT PUSHES EAST ACROSS THE AREA. THIS SHOULD
HELP PUSH SOME OF THE FOG OUT EARLY IN THE MORNING. COLDER AIR AND
WIND GUSTS TO 40 MPH BECOME AN ISSUE DURING THE DAY...ALONG WITH
PRECIPITATION CHANGE FROM LIQUID TO FROZEN AS THE COLUMN COOLS.
POTENTIAL FOR A PERIOD OF MODERATE/LOCALLY HEAVY WET SNOW EXISTS
OVER NORTH CENTRAL/PARTS OF NORTHEAST IL WHERE SOUTHERN PERIPHERY
OF DEFORMATION BAND PASSES. CONFIDENCE NOT SUPER HIGH WITH AMOUNTS
AT THIS POINT...THOUGH NO CHANGES TO WSW HEADLINES AT THIS TIME.
RATZER
&&
.SHORT TERM...
244 PM CST
UNSEASONABLY WARM/MOIST AIRMASS CONTINUES TO ADVECT NORTH ACROSS THE
REGION THIS AFTN...AND LOOKS TO CONTINUE THROUGH TONIGHT. THE MAIN
CONCERN FOR THE OVERNIGHT WILL BE ON RAINFALL TOTALS AND IF THIS
WILL POSE ANY HYDRO CONCERNS.
STRONG WARM AIR ADVECTION THIS AFTERNOON HAS ALLOWED SFC TEMPS TO
WARM INTO THE 50S ACROSS MUCH OF THE FORECAST AREA WITH DEW POINTS
APPROACHING THE UPPER 40S/ARND 50. THE AXIS OF THE HEAVIER RAINFALL
THIS AFTN HAS SHIFTED TO THE NORTHWEST AND STRETCHES FROM CENTRAL
WISC SOUTHWEST THROUGH FAR EASTERN IOWA. HAVE NUDGED TEMPS OVERNIGHT
UP A TAD...AND EXPECT TEMPS TO REMAIN NEARLY CONSISTENT UNTIL CLOSER
TO DAYBREAK MON WHEN THE FRONTAL BOUNDARY BEGINS TO APPROACH THE
NORTHWEST CWFA. GUIDANCE CONTINUES TO SUGGEST THE LOW DROPPING
SOUTHEAST ACROSS THE UPPER MIDWEST AND THE SECONDARY ONE LIFTING
NORTH FROM THE SOUTHWEST...WILL CONVERGE ACROSS SOUTHWEST LOWER
MICHIGAN JUST BEFORE DAYBREAK MON. THE COLD FRONT WILL BE NEARING
THE WESTERN CWFA ARND DAYBREAK...AND STEADILY SLIDE EAST THRU THE
MORNING. ASSOCIATED WILL BE A SHARP THERMAL TROUGH THAT WILL CAUSE
TEMPS TO STEADILY FALL THROUGHOUT THE MORNING/AFTN. SO THE DAY MAY
START MILD...BUT BY MIDDAY THAT WILL CERTAINLY NOT BE THE CASE WITH
TEMPS GENERALLY IN THE UPR 20S/LOW 30S. PRECIP WILL BE QUICKLY
TRANSITIONING OVER FROM RAIN TO SNOW.
AS THE SNOW BEGINS MIDDAY ACROSS THE NORTHWEST...GUIDANCE HAS BEEN
RELATIVELY CONSISTENT THAT AT ONSET RATIOS WILL HOVER ARND 8:1 TO
9:1...THEN AS THE COLDER AIR ADVECTS IN THOSE RATIOS SHUD STEADILY
CLIMB TO 14:1-17:1 BY LATE MON AFTN/EARLY EVE. COMPOUNDING THE SETUP
WILL BE STEADILY INCREASING PRESSURE GRADIENT THAT WILL CREATE GUSTY
WINDS NEARING 30-35MPH. THERE IS A NARROW WINDOW WHERE SNOWFALL
RATES COULD NEAR 1-2"/HR FOR A COUPLE HOURS...MAINLY BETWEEN 2-4PM
CST AND MAINLY WEST OF A LASALLE TO CRYSTAL LAKE LINE. HAVE BUMPED
SNOW TOTALS UP TO 2-4" AND COULD SEE IN PORTIONS OF WINNEBAGO COUNTY
3-5" CLOSER TO THE WISC STATELINE IN NORTHERN WINNEBAGO COUNTY.
ELSEWHERE SNOW WILL BEGIN TO ACCUMULATE...BUT EXPECTING MUCH LESS
WITH PERHAPS AN INCH IN CHICAGO AND LESSER TOTALS FURTHER SOUTH.
500MB TROUGH AXIS PIVOTS OVERHEAD MON EVE...AND WILL SLOWLY BRING AN
END TO THE ACCUMULATING SNOW. THE BETTER MOISTURE WILL QUICKLY PEEL
OFF TO THE NORTHEAST LATE MON NGT...HOWEVER ENOUGH OMEGA/MOISTURE TO
KEEP MENTION OF LGT SNOW SHOWERS MON NGT.
OVERNIGHT LOWS MON DIP FALL TO THE LOW 20S TO MID 20S IN THE
SOUTHEAST.
BEACHLER
&&
.LONG TERM...
244 PM CST
TUESDAY THROUGH WEDNESDAY...
LARGE MID-LVL TROUGH WILL BE IN PLACE TUE/WED WITH A WEAK SFC RIDGE
LIFTING NORTH AND BRINGING A GRADUAL EROSION TO THE CLOUDS TUE
NGT/WED. UNFORTUNATELY THIS MAY BE SHORT LIVED AS GUIDANCE SUGGESTS
A QUICK SHORTWAVE WILL DROP SOUTH FROM CENTRAL CANADA INTO THE
NORTHERN PLAINS EARLY WED...AND APPROACH THE FORECAST AREA MIDDAY
WED. THIS SYSTEM COULD BRING ANOTHER PERIOD OF LIGHT SNOW WITH SOME
MINOR ACCUMULATIONS.
TEMPS TUE WILL REMAIN IN THE 20S...HOWEVER WITH SOME THINNING IN THE
CLOUDS FOR WED TEMPS COULD REBOUND INTO THE LOW/MID 30S. BUT IT WILL
HINGE UPON THE ARRIVAL OF THE NEXT MID-LVL WAVE AND CLOUD COVER.
THURSDAY THROUGH SATURDAY...
ENSEMBLES IN THE LONGER TERM CONTINUES TO POINT TOWARDS A TROUGH
CARVED OUT ACROSS THE GREAT LAKES/TENN VALLEY FOR THE SECOND HALF OF
THE WEEK...AND THEN BEGINS TO FLATTEN FOR THE SECOND HALF OF THE
WEEKEND. AT THIS TIME GUIDANCE SUGGESTS DRY AIR AND A SFC RIDGE
OVERHEAD FOR THANKSGIVING DAY. TEMPS WILL GENERALLY BE IN THE 20S
FOR THE BULK OF THE EXTENDED.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* IFR CIGS PERSIST THROUGH THE NIGHT AND MAY LOWER TO 300-400 FT.
* STEADY RAIN TURNS TO DRIZZLE OVERNIGHT WITH STEADIER RAIN
RETURNING AFTER DAYBREAK/MID MORNING.
* IFR VSBY LIKELY OVERNIGHT WITH OCCASIONAL VSBY BELOW 3/4SM.
HIGHER LIKELIHOOD FOR ORD THAN MDW.
* LIGHT/VARIABLE WINDS OVERNIGHT SHIFT WEST MONDAY MORNING THEN
SOUTHWEST WITH GUSTS TO 30 KT WITH A PERIOD OF 35 KT GUSTS
POSSIBLE MIDDAY/EARLY AFTERNOON.
* RAIN CHANGES TO SNOW MIDDAY/EARLY AFTERNOON...SOME LIGHT
ACCUMULATION POSSIBLE...ESPECIALLY LATER IN THE DAY.
* IFR CIGS LIFTING TO MVFR LATE THIS AFTERNOON
KMD
//DISCUSSION...UPDATED 06Z...
BAND OF LIGHT/OCCASIONALLY MODERATE RAIN IS LIFTING NORTHWEST
THROUGH THE TERMINALS EARLY THIS MORNING WITH WIDEPREAD IFR CIGS
AND LARGELY IFR/LIFR VSBYS WITH A SMALL CORRIDOR IN THE SOUTHWEST
FROM KIIK TO KMDW SOUTHEASTWARD. EXPECT VSBYS TO DROP ACROSS THE
AREA AS THE FIRST ROUND OF RAIN DISSIPATES SOME AND LIGHTER WINDS
CONTINUE.
THE NEXT BATCH OF PRECIPIATION IS FORECAST TO MOVE THROUGH JUST
AFTER DAYBREAK WITH INITIAL PRECIPITATION TYPE AS -RA. EXPECT CIGS
TO REMAIN IFR BUT PROBABLY LIFT SOME AS WEST WINDS BEGIN TO PICK
UP WITH LOW PRESSURE MOVING NORTHEASTWARD WITH -RASN MIX AROUND
15Z AT KRFD AND A FEW HOURS LATER IN THE CHICAGO AREA...TURNING TO
ALL -SN. MOISTURE WIL BE DECREASING FROM SOUTH TO NORTH AS THE
TRANSITION FROM -RA TO -SN OCCURS. THE HIGHEST LIKELIHOOD FOR
ACCUMS IS WEST OF THE MAIN CHICAGO TERMINALS TOWARD ROCKFORD...BUT
SOME ACCUMS ARE CERTAINLY STILL PLAUSIBLE EVERYWHERE. LOOKS LIKE A
MIX OF SNOW SHOWERS OR POSSIBLY MORE FLURRIES OVERNIGHT WITH AN
IFR TRANSITION TO MVFR.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH IN IFR CONTINUING WITH SOME LOWERING OVERNIGHT.
* HIGH CONFIDENCE IN STEADIER RAIN DIMINISHING TO DRIZZLE
OVERNIGHT WITH STEADIER RAIN RETURNING AFTER DAYBREAK/MID
MORNING.
* MEDIUM-HIGH CONFIDENCE IN VSBY FALLING TO IFR OVERNIGHT. LOW-
MEDIUM CONFIDENCE IN POTENTIAL TO GO BELOW 1SM...HIGHER
CONFIDENCE FOR ORD.
* HIGH CONFIDENCE IN WIND TRENDS TONIGHT BUT MEDIUM CONFIDENCE IN
DIRECTION/SPEED DETAILS.
* HIGH CONFIDENCE IN WIND FORECAST MONDAY AND 30+ KT GUSTS. MEDIUM
CONFIDENCE IN SPORADICALLY REACHING 35 KT OR SO.
* HIGH CONFIDENCE IN RAIN CHANGING TO SNOW BUT LOW CONFIDENCE IN
HOW MUCH PRECIP COVERAGE THERE WILL BE THROUGH THE
AFTERNOON/EVENING.
* HIGH CONFIDENCE ON CIG TRENDS...LOW-MEDIUM ON WHEN IFR LIFTS TO
MVFR AND HOW LONG MVFR LASTS.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...MVFR CIGS POSSIBLE WITH A FEW FLURRIES IN THE MORNING.
WEST WINDS.
WEDNESDAY...CHANCE OF SNOW. MVFR/IFR PSBL. SSE WINDS TURNING WEST.
THURSDAY...SCHC SNOW...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST WINDS.
MDB
&&
.MARINE...
154 AM CST
DEEPENING LOW PRESSURE IS PASSING OVER THE LAKE EARLY THIS MORNING
BRINGING A LULL IN WINDS AND WAVES. THE LOW WILL CONTINUE NORTHEAST
INTO SOUTHWEST QUEBEC LATER THIS AFTERNOON THEN REMAIN STEADY AS IT
PUSHES OFFSHORE OVER NOVA SCOTIA. A STRONG SOUTHWEST TO NORTHEAST
ORIENTED PRESSURE GRADIENT WILL REACH THE SOUTH TIP OF THE LAKE BY
15Z...THEN SPREAD OVER THE REMAINDER OF THE LAKE IN THE AFTERNOON.
GALES LOOK SOLID FOR THE SOUTH HALF OF THE THE LAKE...BUT DUE TO A
WEAKENING PRESSURE GRADIENT WITH TIME TODAY AND A MODEST HIGH
BUILDING INTO THE CANADIAN PRARIES AND UPPER MIDWEST...FEEL THAT
WINDS WILL LIKELY PEAK JUST UNDER GALES FOR THE NORTH HALF. A FEW
GALE FORCE GUSTS ARE POSSIBLE...ESPECIALLY LATE AFTERNOON/EARLY
EVENING.
WEAK HIGH PRESSSURE EXTENDING FROM THE NORTH TIP OF LAKE SUPERIOR TO
THE OHIO VALLEY PASSES OVER THE LAKE TUESDAY AFTERNOON. ANOTHER
WEAKENING LOW EMERGING FROM THE CANADIAN ROCKIES WILL PASS JUST
SOUTH OF THE TIP OF LAKE MICHIGAN WITH THE REMNANT INVERTED TROUGH
CLEARING THE LAKE BY THURSDAY MORNING. THIS WILL BE FOLLOWED BY WEAK
HIGH PRESSSURE FOR A FEW DAYS.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-
ILZ011...NOON MONDAY TO MIDNIGHT TUESDAY.
WINTER WEATHER ADVISORY...ILZ005-ILZ006-ILZ012...3 PM MONDAY TO
MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 AM MONDAY TO 3 AM TUESDAY.
&&
$$
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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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1147 PM CST Sun Nov 23 2014
.UPDATE...
ISSUED AT 910 PM CST SUN NOV 23 2014
Double low pressure centers have developed this evening, with one
circulation just northeast of Lawrenceville and another just west
of Galesburg. The trough connecting the two lows generally marks
the line of the back edge of steady rains and the onset of drizzle
and fog. Additional rains are approaching from across Missouri and
Iowa associated with increasing jet dynamics and a potential
vorticity anomaly. The return of steadier rains after midnight
from west to east will diminish fog and drizzle conditions as
winds steadily increase from the WSW. Colder air will approach
Illinois late tonight, but there will not be a deep enough layer
of cold air at the surface to change any rain to snow before
12z/6am in our counties. However, the blast of cold air will
quickly advance across IL Monday morning, with west winds
increasing to near wind advisory levels /30 mph sustained winds or
gusts to 45 mph/. Most areas should remain below those numbers, so
no wind advisory has been issued in our forecast area to this
point.
As the cold air changes any rain to snow, snow accums still look
possible generally north of a line from Rushville to Lincoln to
Bloomington, especially north of Peoria where up to an inch of
snow could accumulate. The snow will be blowing sideways as it
falls due to the strong winds, which will make it very difficult
to measure, and any accumulations on the ground will be blown
around as well. Visibility could drop to low levels during the
snows from mid morning to early afternoon, before snowfall rates
diminish during the afternoon.
Updates this evening have focused on weather grids through
tomorrow afternoon, and updated info is already available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 313 PM CST SUN NOV 23 2014
Deepening 993 mb low pressure between Oklahoma City and Tulsa at mid
afternoon will strengthen further as it ejects northeast across
central IL near or east of I-55 during this evening, and into
northern lower MI overnight at it deepens to 979 mb. Widespread
light to moderate rain showers have spread NNE across central/se IL
early this afternoon. Still no reports of thunder over IL but will
continue to carry isolated thunderstorms over eastern IL into this
evening as deepening low pressure approaches.
Showers will break up later this evening and overnight east of the
IL river while deformation zone of precipitation lingers west of the
IL river. Strong cold front sweeps across central and eastern IL
during overnight, passing through the Wabash river valley early
Monday morning. Light rain to mix with light snow nw of the IL river
late tonight and change to snow early Monday morning as temps fall
into the mid 30s. Temperatures currently in the low to mid 50s and
dewpoints are in the upper 40s and lower 50s. Lows tonight to range
from mid 30s from Peoria and Springfield west, to the mid to upper
40s near the IN/IL border with temps continue to drop Monday
morning. Southeast winds 10-17 mph and gusts of 18-25 mph this
afternoon to subside this evening to around 10 mph or less as low
pressure moves in. But as low deepens and pulls away from central/se
IL overnight, winds will turn westerly behind the cold front and
increase to 15-25 mph and gust 25 to 30 mph later tonight. RUC model
shows even higher wind gusts of 35-40 mph going into southeast IL
behind cold front early Monday morning around sunrise. MET/MAV
guidance shows strongest winds during the day Monday (strongest in
eastern IL) after 15Z/9 am Monday.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 313 PM CST SUN NOV 23 2014
The strong low pressure area will continue to lift northeast through
the Great Lakes area with a very strong pressure gradient behind the
system. In addition, gusty westerly winds and strong cold air
advection (CAA) will move into the area Monday. Expecting rain in
the eastern half of the CWA and a mix of rain and snow in the
western half,in the morning. Then as the CAA occurs, the all snow
line will move across the area from west to east, so that by early
afternoon, most of the CWA will be all snow, with the mix of rain
and snow only in the eastern parts of the CWA. By late afternoon,
the whole area will be cold enough for snow. As the system lifts
northeast through the day, the higher chances of pcpn will move from
southwest to northeast. So, the areas mostly likely to see any
accumulation of snow will be Northwest of I-55 during the morning and
then north of a Galesburg to Bloomington line during the afternoon.
Total snowfall accumulation expected tomorrow will be an inch or
more northwest of a Macomb to Pontiac line; and then lesser amounts
southeast of that line. Highest amounts are expected to be 1.5 to 2
inches north of a Galesburg to Lacon line.
The tight gradient behind this system will also bring very gusty
winds to the CWA tomorrow, beginning tomorrow morning and lasting
through the day. Sustained winds or around 25 mph with gusts between
35 and 40 mph will be possible across the whole area tomorrow. Will
not be issuing a wind advisory as it will be just below criteria.
However, would not be surprised if overnight shift issues one in the
morning. The gusty winds will also create blowing snow, mainly in
the northern parts of the CWA, so visibilities could be reduced at
times.
Pcpn will end by tomorrow night as the low pressure area lifts
northeast into Canada. After this system, dry weather is expected
for Monday night through Tue night as brief high pressure area moves
through the CWA. Then another clipper system is expected to move
through the area and bring another chance of rain and/or snow for
Wednesday. There will be some warm air ahead of this system so the
pcpn type could be a mix before it changes to all snow. Any
accumulations with this system will be confined to the north with a
half inch or less possible...at this time. The remainder of the
forecast should be dry with temps below normal, as Canadian high
pressure moves in and dominates the weather through the rest of the
week and into the weekend.
Temps will steady or slowly falling tomorrow due to the strong CAA
expected. Then temps will be cool/cold most of the rest of the
forecast, except for Wed, just ahead of the next clipper system.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1147 PM CST SUN NOV 23 2014
The pair of surface low centers have merged and lifted to the NE
of our forecast area, with a trailing cold front to the SW across
IL into southeast Missouri. Drizzle, fog and low clouds are
lingering behind the departing low along that trough, with VLIFR
ceilings at BMI, and LIFR ceilings at the remaining TAF sites.
Expect ceilings to improve slightly with the return redevelopment
of showers well behind the low, but remaining LIFR until Monday
afternoon when levels possibly climb all the way to MVFR.
Cold air will filter into central IL late tonight and Monday
morning, causing the rain showers to mix with or change to light
snow from west to east toward 6 am for PIA/SPI, 8 am for BMI, and
10 am for CMI/DEC. As the precipitation becomes all snow, vsbys
could drop below 1 mile at PIA and BMI where snowfall accumulation
could climb up as high as 1 inch. Vsbys should remain 2-4 miles
farther south toward I-72 where snowfall will be lighter. Snowfall
rates will diminish quickly after 18z-19z, with high winds blowing
any snow around and possibly keeping visibility low at times.
Winds have already become SW behind the low. Pressure rises will
climb to 6 mb/3 hours in at least the southeast half of our
forecast area, which would include DEC/CMI. Wind speeds in our
southeast areas could climb as high as 30g40kt between 12z and 15z
this morning, with other areas 25g35kt. Those speeds could
continue into early afternoon, but we should see some decrease in
peak gusts as the afternoon progresses.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...07
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1151 PM EST SUN NOV 23 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 307 PM EST SUN NOV 23 2014
AN AREA OF LOW PRESSURE AND A COLD FRONT WILL BRING RAIN TO CENTRAL
INDIANA TONIGHT INTO MONDAY. BEHIND THE FRONT WILL COME WINDY AND
MUCH COLDER CONDITIONS. ANOTHER SYSTEM COULD BRING SOME LIGHT RAIN
AND SNOW TO THE AREA ON WEDNESDAY. THANKSGIVING INTO SATURDAY WILL
BE COLD AND DRY BEFORE ANOTHER SYSTEM BRINGS LOW CHANCES FOR
PRECIPITATION SUNDAY.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 959 PM EST SUN NOV 23 2014
DUAL AREAS OF LOW PRESSURE CURRENTLY IN THE PROCESS OF COALESCING
ACROSS CENTRAL ILLINOIS AND INTENSIFYING. A WARM FRONT EXTENDS
SOUTHEAST FROM THE DOUBLE BARRELED LOW INTO THE SOUTHERN
APPALACHIANS WITH A LARGE AREA OF MODERATE TO OCCASIONALLY HEAVY
RAINFALL ENCOMPASSING MUCH OF THE FORECAST AREA NORTH OF THE
FRONT. TEMPS WERE IN THE LOWER AND MIDDLE 50S AS OF 0230Z.
FORECAST IS IN REALLY GOOD SHAPE...WITH JUST SOME MINOR
ADJUSTMENTS FOR THE REST OF THE OVERNIGHT. INITIAL POCKET OF DRY
AIR LIFTING UP THROUGH EASTERN COUNTIES RIGHT NOW WITH THE MORE
EXPANSIVE DRY SLOT SOUTH OF THE WARM FRONT IN THE LOWER OHIO
VALLEY. HEAVIEST AREA OF RAIN MOVING NORTH OUT OF THE INDY METRO
AREA AND WILL LIFT NORTH OUT OF THE FORECAST AREA BY 06Z. MANY
LOCATIONS ACROSS CENTRAL INDIANA ALREADY AROUND 1.50 INCHES FOR
THE DAY.
WRF AND HRRR BOTH HAVE A NICE HANDLE ON THE RAINFALL COVERAGE
WITH A 3-4 HOUR DRY SLOT EXPANDING ACROSS THE FORECAST AREA FROM
THE BETWEEN 05-10Z AS THE WARM FRONT LIFTS NORTH. WILL KEEP LOWER
POPS DURING THIS TIMEFRAME...THEN RAMP THEM BACK UP TOWARDS
DAYBREAK AS THE CONVECTION OVER SOUTHERN MISSOURI ARRIVES AHEAD OF
THE COLD FRONT. HAVE BACKED OFF ON ISOLATED THUNDER TO LATE
TONIGHT AND EARLY MONDAY MORNING AS THE CONVECTION ALONG THE COLD
FRONT TRACKS THROUGH THE AREA.
TEMPS SHOULD WARM A COUPLE MORE DEGREES OR REMAIN STEADY OVER THE
NEXT SEVERAL HOURS BEFORE BEGINNING TO SLIP BACK TOWARDS DAYBREAK
WITH THE ARRIVAL OF THE COLD FRONT. WINDS WILL BECOME GUSTY
OVERNIGHT AS WELL AS ALREADY SEEING OBS WITH GUSTS PUSHING 30MPH
IN WESTERN KENTUCKY.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
ISSUED AT 307 PM EST SUN NOV 23 2014
FOCUS IS ON WINDY CONDITIONS MONDAY AND ON ANY CHANCES FOR RAIN
THROUGH THE PERIOD. FOR THE MOST PART MODELS ARE CLOSE ENOUGH THAT A
BLEND CAN BE USED...BUT GFS LOOKS TOO FAST WITH WEDNESDAY/S SYSTEM.
RELIED LESS ON GFS THEN.
LOOKS LIKE THERE WILL BE SOME DECENT FORCING WITH THE COLD
FRONT...AND MOST MODELS ARE PUTTING OUT RAINFALL WITH THE FRONT AS
IT PASSES THROUGH. THUS WENT LIKELY POPS MOST AREAS MONDAY MORNING.
AS FRONT PASSES BY FORCING WILL WEAKEN SO LOWERED POPS AFTER IT GOES
BY.
FORCING WITH THE UPPER TROUGH WILL STILL BE CLOSE ENOUGH TO THE AREA
TO GO CHANCE POPS ACROSS THE NORTHWEST FORECAST AREA MONDAY
AFTERNOON AND SLIGHT CHANCE REMAINDER OF NORTH HALF. AS COLDER AIR
MOVES IN DURING THE DAY PRECIPITATION WILL MIX WITH AND CHANGE TO
SNOW. NOT EXPECTING ANY ACCUMULATION AT THIS TIME.
MAIN STORY MONDAY WILL BE THE WINDS. STRONG WINDS WILL BE NOT TOO
FAR OFF THE SURFACE...WITH 850MB WINDS OVER 50KT AND 925MB WINDS
OVER 40KT. SURFACE PRESSURE GRADIENT WILL BE TIGHT ACROSS THE AREA.
THESE PLUS COLD ADVECTION HELPING MIX THE WINDS DOWN WILL CREATE
WINDY CONDITIONS ACROSS THE ENTIRE AREA. SREF FORECASTS SHOW HIGH
CHANCES OF SUSTAINED WINDS OVER 25KT ACROSS PARTS OF THE AREA MONDAY
AS WELL.
STRONGEST WINDS LOOK TO BE ACROSS THE NORTHEAST FORECAST AREA IN THE
TIGHTER PRESSURE GRADIENT WHERE WIND GUSTS AROUND 45 MPH WILL BE
POSSIBLE. ELSEWHERE WINDS COULD GUST AROUND 40 MPH AND WILL BE CLOSE
TO ADVISORY CRITERIA. /GFS SHOWS EVEN HIGHER GUSTS POSSIBLE...WITH
GUSTS MORE WIDESPREAD THAN THE NAM/. AFTER COLLABORATING WITH
SURROUNDING OFFICES DECIDED TO GO WIND ADVISORY ACROSS ALL OF THE
AREA.
FOR MOST AREAS WENT 12Z-00Z...BUT IN THE NORTHEAST WHERE PRESSURE
GRADIENT WILL ARRIVE LATER AND REMAIN A FACTOR LONGER...WENT 14Z-03Z.
UPPER TROUGH COULD STILL BRING A FEW SNOW SHOWERS TO NORTHERN AREAS
MONDAY NIGHT. HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE AREA
TUESDAY INTO WEDNESDAY MORNING.
ANOTHER FRONT WILL BRING CHANCES FOR PRECIPITATION WEDNESDAY
AFTERNOON. UNCERTAINTIES IN TIMING AND FORCING LEADS TO ONLY LOW
POPS FOR NOW. BASED ON EXPECTED TEMPERATURES WENT MIXED RAIN AND
SNOW MOST AREAS.
LOOKING AT TEMPERATURES...ON MONDAY READINGS WILL FALL DURING THE
DAY. A MODEL BLEND LOOKS GOOD FOR LOWS MONDAY NIGHT. MAV MOS LOOKS
TOO WARM ON TUESDAY WITH EXPECTED CLOUD COVER. WENT CLOSER TO A
MODEL BLEND.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 224 PM EST SUN NOV 23 2014
A BROAD UPPER TROUGH MAY BRING MIX PRECIP CHANCES TO THE AREA AT THE
BEGINNING OF THE PERIOD AND THEN ZONAL FLOW WILL COMMENCE THROUGH
THE FIRST HALF OF NEXT WEEKEND. AN UPPER LEVEL DISTURBANCE IS NEXT
DUE TO IMPACT THE REGION SATURDAY NIGHT INTO SUNDAY WITH CHANCES FOR
RAIN/RAIN AND SNOW MIX/AND SNOW. ACCUMULATIONS APPEAR VERY LIGHT AT
THIS TIME AND THIS IS NOT A LOT OF CONFIDENCE THIS FAR OUT IN THE
EXTENDED SO STUCK WITH 20 PERCENT POPS. SUPERBLEND GUIDANCE
INITIALIZED WELL. ONLY NEED TO MAKE A FEW MINOR TWEAKS.
&&
.AVIATION /DISCUSSION FOR THE 24/06Z TAFS/...
ISSUED AT 1151 PM EST SUN NOV 23 2014
MVFR OR WORSE CONDITIONS TO PERSIST THROUGH AT LEAST THE FIRST 10-12
HOURS OF THE PERIOD.
RAPIDLY STRENGTHENING LOW PRESSURE MOVING THROUGH THE REGION TONIGHT
INTO TOMORROW. DRY PUNCH MOVING INTO THE AREA BUT ADDITIONAL SHOWERS
LIKELY AT TIMES LATER IN THE NIGHT INTO EARLY MORNING.
COULD SEE SOME GUSTINESS OVERNIGHT AS THE LOW STRENGTHENS. LOW LEVEL
WIND SHEAR IS A MORE POTENT THREAT EAST OF THE SITES WHERE THE LOW
LEVEL JET WILL BE FAR MORE PRONOUNCED...AND AREA VAD WIND PROFILES
SUPPORT WINDS BELOW 2KFT NO MORE THAN 30-35KT AT THIS TIME...AND
GUSTINESS IMPLIES SHEAR ANYWAY.
AS THE COLD FRONT PASSES TOMORROW MORNING AND THE SURFACE PRESSURE
GRADIENT TIGHTENS...LOW LEVEL WINDS WILL STRENGTHEN AND COLD
ADVECTION WILL HELP MIX SOME OF THIS DOWN TO THE SURFACE. WIND GUSTS
FROM THE WEST/SOUTHWEST MAY APPROACH AND EVEN OCCASIONALLY EXCEED
40KT AT THE SITES...ESPECIALLY TOMORROW AFTERNOON.
THUNDER WILL BE AT LEAST A MARGINAL THREAT WITH THE RAPID
DEVELOPMENT OF THE LOW...STRONG DYNAMICS...AND AT LEAST A SMALL
AMOUNT OF SHALLOW INSTABILITY...BUT WITH NO CONFIDENCE IN TIMING OR
PLACEMENT OF THE THREAT...CANNOT INCLUDE A MENTION AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 7 AM TO 7 PM EST MONDAY FOR INZ021-028>030-
035>037-039-043>048-051>057-060>065-067>072.
WIND ADVISORY FROM 9 AM TO 10 PM EST MONDAY FOR INZ031-038-
040>042-049.
&&
$$
SYNOPSIS...50
NEAR TERM...RYAN
SHORT TERM...50
LONG TERM...SMF
AVIATION...NIELD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
415 AM EST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 444 PM EST SUN NOV 23 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL
TROUGH ACROSS THE CENTRAL CONUS. THE MORE PROMINENT SHORTWAVE
TROUGHS WERE LOCATED OVER THE DAKOTAS...NEW MEXICO...AND NRN
MS. AT THE SFC...A TROUGH AND FRONTAL BOUNDARY EXTENDED FROM NE
MN THROUGH CNTRL IA TO LOW PRES OVER ERN OK. A BROAD SRLY FLOW OF
GULF MOISTURE INTO THE NRN LAKES HAS RESULTED IN AREAS OF DENSE FOG
OVER THE EXTENSIVE SNOW COVER. A WEAKER SHRTWV OVER WI AND
ASSOCIATED 850-700 MB FGEN SUPPORTED AN AREA OF RAIN THAT WAS
EXPANDING INTO SRN UPPER MI.
TONIGHT...EXPECT THAT THE RAIN WILL CONTINUE TO DEVELOP INTO UPPER
MI THIS EVENING...ESPECIALLY ACROSS THE SE HALF IN PROXIMITY TO THE
STRONGEST FGEN AND ISENTROPIC LIFT. ALTHOUGH AREAS OF DENSE FOG MAY
PERSIST INTO THIS EVENING...THE RAIN SHOULD HELP SCOUR OUT SOME OF
THE FOG FOR SLIGHTLY BETTER VSBY. BY LATE TONIGHT...THE RAIN IS
EXPECTED TO CONTINUE TO INCREASE IN COVERAGE/INTENSITY AS THE MID
LEVEL TROUGH DEEPENS...THE MS SHRTWV LIFTS TO THE GREAT LAKES WITH
INCREASING 700-500 MB QVECTOR CONV.
MONDAY...MODELS SUGGEST THAT THERE MAY BE A LULL IN THE PCPN
BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID LEVEL TROUGH MOVING
IN FROM THE UPPER MS VALLEY. AS THE DEEPENING SFC LOW NEAR THE
STRAITS AT 12Z/MON LIFTS QUICKLY TO THE NE THE COLDER AIR WILL ALSO
SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER TO SNOW
FROM 12Z-21Z FROM W TO EAST. THE PCPN CHANGEOVER WAS DELAYED
SLIGHTLY...PER MODEL TRENDS WITH A BLEND OF THE 12Z NAM AND REGIONAL
GEM 1000-850 LOW LEVEL THICKNESS USED FOR THE RAIN SNOW LINE. WITH
THE LOSS OF THE STRONGER LARGE SCALE FORCING/LIFT TIL AFTERNOON
MAINLY JUST LIGHT TO MODERATE LAKE ENAHANCED SNOW IS EXPECTED OVER
THE WEST HALF FOR NNW FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO
NEAR -8C WEST BY 18Z AND TO AROUND -12C ACROSS WEST AND CNTRL
LOCATIONS BY 00Z. SNOWFALL AMOUNTS IN THE 2 TO 4 RANGE WILL BE
POSSIBLE OVER THE WEST WITH ONLY AROUND AN INCH CENTRAL. A TIGHT
GRADIENT BEHIND THE LOW WILL BRING STRONG NRLY WINDS INTO THE AREA
PRODUCING SOME BLOWING AND DRIFTING SNOW.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON NOV 24 2014
LIGHT TO MODERATE LAKE EFFECT WILL BE ONGOING TO START TUESDAY MORNING
WITH DELTA T/S OVER 15C AND NNW LOW-LEVEL WINDS IN WAKE OF THE
DEPARTING SFC LOW PRESSURE TROUGH. INVERSIONS UP TO 5KFT DOES PUT MOST
OF THE CLOUD BEARING LAYER IN THE DGZ...BUT WITH INCREASING DRYING
AND SUBSIDENCE ALOFT AS MAIN SHORTWAVE MOVES EAST...EXPECT THE LAKE EFFECT
TO DIMINISH THROUGH THE DAY AS LOW-LEVEL WINDS BECOME ANTICYCLONIC
AS RIDGE MOVES IN. ENDING TIMES FOR CURRENT LAKE EFFECT ADVISORIES
SEEM GOOD BASED ON THE DIMINISHING TRENDS IN SNOW SHOWERS AND WINDS/BLSN.
TUESDAY NIGHT INTO WEDNESDAY ONE SHORTWAVE AND A LOW PRESSURE SYSTEM
IS EXPECTED TO DIP ESE FM THE NORTHERN PLAINS TOWARD THE MIDDLE
MISSISSIPPI RIVER VALLEY. SWATH OF SNOW SHOULD ACCOMPANY THIS LOW
PRESSURE AREA AND THAT SHOULD STAY MAINLY SOUTH OF UPPER MICHIGAN.
INVERTED SFC TROUGH WILL BE PRESENT TO THE NORTH OF THE MAIN SFC LOW
AND THAT WOULD EXTEND INTO UPR MICHIGAN. SHORTWAVE LIKELY TO BE THE
MAIN FOCUS FOR THE WEATHER OVR CWA ON WEDNESDAY INTO THANKSGIVING IS
IN THE NORTHERN STREAM AND SLIDES OVER THE AREA FM SOUTHERN MANITOBA
AND NORTHWEST ONTARIO IN THE AFTN. OVERALL...PREFER THE OVERALL IDEA
OFFERED BY THE NAM/GFS/ECMWF COMPARED TO THE GEM-NH AS THAT MODEL
SEEMS TOO PHASED WITH THE NORTHERN STREAM AND SOUTHERN STREAM
SHORTWAVES WITH THE RESULT THAT THE THE MAIN SFC LOW IS TOO FAR
NORTH. ECMWF CONTINUES TO SHOW SHARPER TROUGH/CONVERGENCE AND LAKE
ENHANCED SNOW FOR NORTHWEST CWA NOT UNTIL WED NIGHT THEN OVER NCNTRL
CWA ON THANKSGIVING DAY. GFS CONTINUES TO INDICATE WEAKER OVERALL
SYSTEM BUT DOES BRING THE NORTH WIND LAKE EFFECT SNOW SHOWERS IN
EARLIER...MORE SO ON WEDNESDAY AFTN INTO WEDNESDAY NIGHT. GIVEN COLD
POOL OF AIR TO NORTH OF THE SFC TROUGH WITH H85 TEMPS DOWN TO AS LOW
AS -20C THERE WILL BE CERTAINLY BE SOME LAKE EFFECT SNOW SHOWERS
WEDNESDAY INTO THANKSGIVING. IN ADDITION...WILL NEED TO WATCH LAKE
EFFECT OFF LK MICHIGAN IN THE S/SE WINDS AHEAD OF THE SFC TROUGH.
WINDS BACK STEADILY FROM LATE TUESDAY NIGHT INTO WEDNESDAY OVER
NORTHERN LK MICHIGAN. FORECAST SOUNDINGS POINT TO SCT LAKE EFFECT TO
EXPAND OVER MUCH OF THE EASTERN CWA BY LATE WEDNESDAY AS THE ONSHORE
FLOW IS ENHANCED BY THE LARGER SCALE LIFT AND MOISTURE FM THE NEARING
NORTHERN STREAM SHORTWAVE.
SHARPNESS OF SFC TROUGH AND EXTENT OF CONVERGENCE STILL UNCERTAIN
THOUGH WHICH AFFECTS INTENSITY/EXTENT OF THE LES BOTH OFF LK
SUPERIOR AND LK MICHIGAN AND ALSO THE STRENGTH OF WINDS/BLSN NEAR LK
SUPERIOR IN WAKE OF TROUGH. LATEST RUNS OF GFS AND ECMWF KEEP WITH
CONTINUITY COMPARED TO THEIR PREVIOUS RUNS...GIVING NO TREND TO
LATCH ON. THOSE THAT HAVE TRAVEL PLANS WEDNESDAY INTO THANKSGIVING
NEAR LK SUPERIOR AND ALSO OVER MOST OF THE EAST HALF OF UPR MICHIGAN
SHOULD BE AWARE THAT DURING THIS TIME FRAME THERE COULD AT LEAST
LOCALIZED HIGHER IMPACT WEATHER.
HIGH PRESSURE DIVING OVER THE PLAINS WITH RIDGING OVER NORTHERN
ONTARIO EVENTUALLY SHOULD WIN OUT LATER ON THANKSGIVING. THOUGH IF
THE STRONGER TROUGH FM ECMWF IS CORRECT...DIMINISHING TREND IN THE
LAKE EFFECT WOULD BE MORE ON THURSDAY NIGHT. ONCE THE SFC RIDGE
SLIDES EAST ON FRIDAY...UPPER FLOW FLATTENS OUT ALLOWING FOR WARM
AIR ADVECTION TO RAMP UP OVER THE PLAINS. INDICATIONS THAT AT LEAST
ONE SHORTWAVE WILL ALSO BE PROPELLING FROM THE NORTHERN PLAINS
TOWARD THE WESTERN GREAT LAKES. DECENT JET STREAK ALSO FCST OVER THE
PLAINS WHICH SHOULD ENHANCED LIFT ALONG THE TIGHT LOW-LEVEL
BAROCLINIC ZONE. SWATH OF AT LEAST LIGHT SNOW SHOULD RESULT
SOMEWHERE VCNTY OF NORTHERN PLAINS TO THE WESTERN GREAT LAKES.
CONSIDERING THE WAVE THAT WILL GENERATE THE SNOW IS STILL TO EMERGE
FROM UPPER TROUGH OVER NORTHERN PACIFIC VCNTY OF 40N/155W...GFS IS
CONSISTENT IN SHOWING THIS AND GEM-NH IS THERE AS WELL. ECMWF JUST
TRENDED THIS WAY WITH THE 23NOV/12Z RUN. PLENTY OF TIME TO LOOK AT
THE DETAILS BUT DOES APPEAR THAT PTYPE WILL STAY ONLY SNOW AS WARM
AIR AT H85 IS FORECAST TO REMAIN SOUTHWEST OF UPPER LAKES.
MIXED SIGNALS THAT COULD SEE SOME LGT MIXED PRECIP FRIDAY NIGHT INTO
SATURDAY AS THE H9-H8 WARM LAYER ARRIVES. COULD SEE SOME DRIZZLE AND
FOG ISSUES TOO THOUGH AT LEAST RIGHT NOW...GFS/ECMWF ARE NOT SHOWING
DWPNTS AS HIGH AS ARE CURRENTLY OCCURRING OVER AREA. REAL MODEL
DIFFERENCES TO CLOSE THE LONG TERM...WITH 23NOV/12Z ECMWF KEEPING
THE WARM SECTOR OVER THE AREA INTO SUNDAY...WHILE THE GFS SHOVES
SHARPER COLD FRONT OVER THE UPPER GREAT LAKES BY SUNDAY. AT 12Z
SUNDAY...H85 TEMPS VARY FROM -5C OFF THAT RUN OF ECMWF TO -24C
OFF THE GFS. LATEST ECMWF TRENDED TOWARD GFS AS IT NOW SHOWS H85
TEMP THAT SAME TIME OF -16C. USED A CONSENSUS OF THE MODELS UNTIL
THE DIFFERENCES ARE RESOLVED...BUT GIVEN THE TREND FM THE LATEST
ECMWF...WENT WITH A BIT HIGHER POPS AND LOWERED TEMPS SLIGHTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1233 AM EST MON NOV 24 2014
PERSISTENT LOW CIGS AND FOG WILL CONTINUE OVERNIGHT WITH VLIFR TO
LIFR CONDITIONS PERSISTING. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST
OF THE AREA MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY
STRENGTHEN WITH ANY RAIN CHANGING TO SNOW. LOW CIGS AND VIS WILL
CONTINUE AT ALL TAF SITES THROUGH THE REST OF THE FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 PM EST SUN NOV 23 2014
WINDS WILL BE VARIABLE TONIGHT AS TROUGH CROSSES LAKE SUPERIOR. A
DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR ON MONDAY.
NORTHERLY WINDS WILL INCREASE TO GALES 35-45 KTS BY MONDAY MORNING
INTO MONDAY NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS
TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR MIZ006-007-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM THIS MORNING TO 6 AM EST
TUESDAY FOR MIZ001-003-005-006.
LAKE EFFECT SNOW ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
TUESDAY FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 AM EST TUESDAY FOR
LSZ251-267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TODAY TO 9 PM EST /8 PM
CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1234 AM EST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 444 PM EST SUN NOV 23 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL
TROUGH ACROSS THE CENTRAL CONUS. THE MORE PROMINENT SHORTWAVE
TROUGHS WERE LOCATED OVER THE DAKOTAS...NEW MEXICO...AND NRN
MS. AT THE SFC...A TROUGH AND FRONTAL BOUNDARY EXTENDED FROM NE
MN THROUGH CNTRL IA TO LOW PRES OVER ERN OK. A BROAD SRLY FLOW OF
GULF MOISTURE INTO THE NRN LAKES HAS RESULTED IN AREAS OF DENSE FOG
OVER THE EXTENSIVE SNOW COVER. A WEAKER SHRTWV OVER WI AND
ASSOCIATED 850-700 MB FGEN SUPPORTED AN AREA OF RAIN THAT WAS
EXPANDING INTO SRN UPPER MI.
TONIGHT...EXPECT THAT THE RAIN WILL CONTINUE TO DEVELOP INTO UPPER
MI THIS EVENING...ESPECIALLY ACROSS THE SE HALF IN PROXIMITY TO THE
STRONGEST FGEN AND ISENTROPIC LIFT. ALTHOUGH AREAS OF DENSE FOG MAY
PERSIST INTO THIS EVENING...THE RAIN SHOULD HELP SCOUR OUT SOME OF
THE FOG FOR SLIGHTLY BETTER VSBY. BY LATE TONIGHT...THE RAIN IS
EXPECTED TO CONTINUE TO INCREASE IN COVERAGE/INTENSITY AS THE MID
LEVEL TROUGH DEEPENS...THE MS SHRTWV LIFTS TO THE GREAT LAKES WITH
INCREASING 700-500 MB QVECTOR CONV.
MONDAY...MODELS SUGGEST THAT THERE MAY BE A LULL IN THE PCPN
BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID LEVEL TROUGH MOVING
IN FROM THE UPPER MS VALLEY. AS THE DEEPENING SFC LOW NEAR THE
STRAITS AT 12Z/MON LIFTS QUICKLY TO THE NE THE COLDER AIR WILL ALSO
SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER TO SNOW
FROM 12Z-21Z FROM W TO EAST. THE PCPN CHANGEOVER WAS DELAYED
SLIGHTLY...PER MODEL TRENDS WITH A BLEND OF THE 12Z NAM AND REGIONAL
GEM 1000-850 LOW LEVEL THICKNESS USED FOR THE RAIN SNOW LINE. WITH
THE LOSS OF THE STRONGER LARGE SCALE FORCING/LIFT TIL AFTERNOON
MAINLY JUST LIGHT TO MODERATE LAKE ENAHANCED SNOW IS EXPECTED OVER
THE WEST HALF FOR NNW FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO
NEAR -8C WEST BY 18Z AND TO AROUND -12C ACROSS WEST AND CNTRL
LOCATIONS BY 00Z. SNOWFALL AMOUNTS IN THE 2 TO 4 RANGE WILL BE
POSSIBLE OVER THE WEST WITH ONLY AROUND AN INCH CENTRAL. A TIGHT
GRADIENT BEHIND THE LOW WILL BRING STRONG NRLY WINDS INTO THE AREA
PRODUCING SOME BLOWING AND DRIFTING SNOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 303 PM EST SUN NOV 23 2014
AT 00Z TUE...A SHORTWAVE WILL BE E OF THE CWA WITH THE ASSOCIATED
SFC LOW NEAR JAMES BAY. A WEAKENING UPPER TROUGH WILL BE OVER THE
FAR WRN CWA...WITH A RIDGE NW OF THE TROUGH. THE 12Z/23 NAM HAS COME
INTO BETTER AGREEMENT WITH 12Z/23 GFS AND 00Z/23 ECMWF IN SHOWING
LESS PHASING BETWEEN THE TWO FEATURES...AND THEREFORE HAVING MOST
/BUT NOT ALL/ OF THE SYNOPTIC SNOW NE OF THE CWA BY 00Z TUE. PRECIP
WILL BE ALL SNOW BY 00Z TUE AS 850MB TEMPS WILL FALL TO AOB -12C BY
12Z. WITH THE COLD AIRMASS...LAKE ENHANCEMENT WILL OCCUR IN NNW WIND
SNOWBELTS ALONG AND AHEAD OF THE TROUGH THAT WILL MOVE THROUGH THE
CWA BY 18Z TUE. BEHIND THE TROUGH...WINDS BECOME INCREASINGLY
ANTICYCLONIC...AND LOW LEVEL AIRMASS DRIER...AS THE RIDGE MOVES IN.
WILL CERTAINLY SEE DIMINISHING PRECIP COVERAGE/INTENSITY LATER TUE
INTO TUE NIGHT...BUT LES WILL NOT COMPLETELY END AS LOW LEVEL WINDS
FOCUS LES MORE OVER THE KEWEENAW PENINSULA. WNW WIND SNOWBELTS OF
THE NRN HURON MOUNTAINS AND OVER ALGER COUNTY WILL BE FAVORED FOR
THE GREATEST SNOWFALL AMOUNTS...WITH EXPECTATIONS OF 6-8 INCHES OF
SNOW MON NIGHT AND TUE IN THESE FAVORED LOCATIONS. ELSEWHERE NEAR
LAKE SUPERIOR AROUND 4 INCHES IS EXPECTED MON NIGHT/TUE...WITH LESS
AMOUNTS OF 1-3 INCHES INLAND. AFTER COORDINATION WITH SHORT TERM
SHIFT...LAKE EFFECT SNOW ADVISORIES HAVE BEEN ISSUED FOR ALL
COUNTIES ALONG LAKE SUPERIOR. AT LEAST FOR MON NIGHT/TUE...SNOW TO
LIQUID RATIOS SHOULD BE HIGH ENOUGH FOR THE LAKE EFFECT HEADLINE
INSTEAD OF WINTER WEATHER ADVISORIES. ALSO...BLOWING SNOW WILL OCCUR
ALONG LAKE SUPERIOR.
CONFIDENCE DECREASES SIGNIFICANTLY FOR WED THROUGH NEXT WEEKEND. FOR
WED INTO THU...MODELS AGREE IN SHOWING TWO SHORTWAVES MOVING INTO
THE CENTRAL CENTRAL U.S. WED...BUT DISAGREE ON THE
STRENGTH/TRACK/PHASING OF THE TWO WAVES...WHICH LEADS TO A WIDE
VARIETY OF SOLUTIONS FOR THE CWA. THE ECMWF PHASES THE WAVES OVER
THE REGION...WHICH LEADS TO A 1003MB SFC LOW MOVING FROM NEAR MPX AT
12Z WED TO LAKE HURON AT 12Z THU. THIS SOLUTION WOULD RESULT IN
SIGNIFICANT SNOWFALL AMOUNTS ACROSS THE CWA WED INTO THU. THE GFS
KEEP THE WAVES OUT OF PHASE AND THE SRN MOST WAVE MUCH FARTHER
S...LEAVING JUST A LITTLE LAKE ENHANCEMENT WED INTO WED NIGHT AS THE
NRN SHORTWAVE CROSSES THE AREA. OTHER MODELS HAVE VARYING SOLUTIONS
BETWEEN THESE TWO EXTREMES. NOT REALLY ABLE TO PICK BETWEEN THE
MODELS GIVEN THE NORMAL LOW CONFIDENCE WITH SHORTWAVE ENERGY AND
GENERALLY GOOD RUN TO RUN CONTINUITY OF THE GFS AND ECMWF WITH THIS
SYSTEM.
REGARDLESS OF SOLUTION...SHOULD SEE LES THU INTO THU NIGHT IN NW
WIND SNOWBELTS UNDER -18C TO -20C 850MB TEMPS. HOWEVER...THE GFS
THEN BRINGS WINDS OUT OF THE SW THU NIGHT AHEAD OF A STRONG CLIPPER
SYSTEM IT SHOWS MOVING INTO THE NRN PLAINS THU NIGHT AND ACROSS THE
CWA FRI NIGHT. ALL THE WHILE...THE ECMWF SHOWS A STRONG SFC HIGH
MOVING FROM THE NRN PLAINS TO THE MID MISSISSIPPI VALLEY. THE ECMWF
WOULD KEEP LES GOING IN NW-WNW SNOWBELTS THROUGH FRI...WHILE THE GFS
SOLUTION WOULD OBVIOUSLY NOT GIVEN THE CHANGE IN WINDS WITH THE SFC
LOW MOVING ACROSS THE CWA AND 850MB TEMPS INCREASE TO AROUND
0C...BUT DOES BRING LES BACK ON SAT BEHIND THE CLIPPER. MODELS DO
SHOW SOME AGREEMENT IN LOW LEVEL WINDS BECOMING FROM THE WSW BY SUN
WITH CONTINUED /BUT LIGHTER/ LES. WILL STICK CLOSER TO THE PREVIOUS
FORECAST GIVEN THE HIGH UNCERTAINTY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1233 AM EST MON NOV 24 2014
PERSISTENT LOW CIGS AND FOG WILL CONTINUE OVERNIGHT WITH VLIFR TO
LIFR CONDITIONS PERSISTING. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST
OF THE AREA MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY
STRENGTHEN WITH ANY RAIN CHANGING TO SNOW. LOW CIGS AND VIS WILL
CONTINUE AT ALL TAF SITES THROUGH THE REST OF THE FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 PM EST SUN NOV 23 2014
WINDS WILL BE VARIABLE TONIGHT AS TROUGH CROSSES LAKE SUPERIOR. A
DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR ON MONDAY.
NORTHERLY WINDS WILL INCREASE TO GALES 35-45 KTS BY MONDAY MORNING
INTO MONDAY NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS
TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
DENSE FOG ADVISORY UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR
MIZ001>007-009>014-084-085.
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR MIZ006-007-085.
LAKE EFFECT SNOW ADVISORY FROM 7 AM EST /6 AM CST/ THIS MORNING
TO 7 AM EST /6 AM CST/ TUESDAY FOR MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM THIS MORNING TO 6 AM EST
TUESDAY FOR MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
TUESDAY FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 AM EST TUESDAY FOR
LSZ251-267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM THIS MORNING TO 2 AM EST TUESDAY FOR
LSZ242>245-263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TODAY TO 9 PM EST /8 PM
CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1135 PM CST Sun Nov 23 2014
.UPDATE...
Issued at 944 PM CST SUN NOV 23 2014
Back edge of rain shield has accelerated eastward over the past hour
in line with the 00Z NAM and latest HRRR output. Will end the rain
faster from west to east. In addition, will limit any mention of snow
to the n central and northeastern counties where temperatures in the
upper 30s are advecting southeast out of central/south central IA.
Will leave in mention of minor snow accumulations for these areas.
&&
.SHORT TERM...(This Evening through Wednesday Afternoon)
Issued at 307 PM CST SUN NOV 23 2014
Rain showers will continue to fill in this afternoon and evening,
impacting the forecast area along and ahead of a southeastward-
moving cold front. Rainfall totals for this evening should be mainly
less than a half of an inch in most locations.
Main focus in the short term will be the potential for rain changing
over to snow overnight as a cold front pushes through the area and a
band of post-frontal precipitation pushes eastward over the falling
temperatures. Soundings begin to support snow in our far northwest
around 03z to 06z, but initially the surface warm layer will be too
thick for snow to make it to the surface. As the near-surface layer
cools, rain will begin to mix with and then eventually change over
to snow mainly between 06z and 12z tonight. Precipitation amounts
during this time are anywhere from trace to 0.20", but with the warm
temperatures ahead of the front and warm/wet surface conditions, it
will take a pretty aggressive snow rate to accumulate any snow. Have
painted an area of 0.5-0.75" snow across northeast MO where the
coldest post-frontal temperatures and highest snowfall rates are
expected as the band moves through, then have tapered snow amounts
to zero elsewhere. The post-frontal band is expected to exit the
region by 12z, then perhaps just a dusting of light snow could wrap
back into northeast MO during the late morning/afternoon hours.
Lows tonight should not drop far below freezing with the bulk of the
cold air waiting until after 12z to push into the region, but little
to no temperature rise is expected across northern MO on Monday as
cold air continues to filter in. Elsewhere, highs may recover a bit
into the lower 40s by mid afternoon.
The next system will be a quick clipper that dives from Alberta into
northeast Missouri on Tuesday night into Wednesday morning. Light
snow is possible across the northeastern half of the CWA with this
feature, but low moisture availability will limit potential snow
accumulations to just a few tenths of an inch.
.LONG TERM...(Wednesday Evening through Sunday)
Issued at 307 PM CST SUN NOV 23 2014
Much of the long-term (particularly into next weekend) is plagued
spatially and temporally with model discrepancies with the GFS,
ECMWF, and the GEM struggling to agree, although the 12Z ECMWF has
come into a bit of a better agreement with the 12Z GFS as compared
to the 00Z ECMWF run. Low amplitude ridging at the 500mb level
appears to dominate much of the center of the country behind an
exiting sharp trough, according to the latest GFS and ECMWF runs
whereas the GEM brings a shortwave trough racing down from Canada
into MT/ND before phasing into a larger wave dominating over
Ontario. Regardless of which solution ends up playing out, they do
all generally agree on zonal flow aloft with ripples riding through
behind the NW flow on the backside of the aforementioned exiting
trough.
Between the GFS and the ECMWF, the GFS appears to be much more
progressive aloft and at the surface as compared to the ECMWF. High
pressure sinking south behind an exiting surface low takes hold of
the forecast area on Thursday, then quickly scoots across the Ohio
Valley, leaving the door open for a frontal boundary to sweep
through behind the high, according to the GFS. The ECMWF solution is
messier and slower and diverges significantly from the GFS at the
surface by next weekend. Taking all of this into account, have kept
the forecast area dry for this forecast period given a lack of a
clear precip-generating signal, except for the GFS that brings the
front through on Saturday, but again is low confidence given the
vastly different solutions.
With respect to temperatures, they look to remain on the cooler side
of normal through the end of the week, but again, the forecast for
the temps from late Friday onward has low confidence given the
discussed model discrepancies.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1133 PM CST SUN NOV 23 2014
Back edge of rain shield will exit northeast and central MO by pre-
dawn hours of Monday morning. Could see a rain/snow mix or brief
change over to snow over far northeast MO but little if any accumulation.
Otherwise, main concern will be from gusty northwesterly winds. Tight
pressure gradient will gradually weaken from west to east on Monday
but boundary layer mixing could see winds ramp up higher during the
late morning and early afternoon hours. VFR cigs at all four
terminals but MVFR cigs possible Monday across northern MO. Also
can`t rule out widely scattered flurries over northern MO. Will see
winds diminish from west to east early Monday evening with clearing
from west to east.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...Laflin
LONG TERM...lg
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
240 AM CST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 240 AM CST MON NOV 24 2014
ALOFT: THE NEWLY REESTABLISHED LONGWAVE TROF AXIS WAS SHIFTING E
OF THE FCST AREA. BACK TO NW FLOW THRU TONIGHT. THE NEXT SHORTWAVE
TROF TO AFFECT THE FCST AREA WAS OVER BRITISH COLUMBIA. THIS TROF
WILL PASS THRU HERE TONIGHT WITH ONLY AN INCREASE IN HIGH CLOUDS.
SURFACE: THE FCST AREA WAS IN THE COLD SECTOR OF DEEP LOW PRES
OVER THE GREAT LAKES THIS MORNING. WE WILL REMAIN IN THE COLD
SECTOR THRU TONIGHT. WRN USA HIGH PRES WILL GRADUALLY BUILD IN
WITH CYCLONIC BOUNDARY LAYER FLOW BECOMING ANTICYCLONIC. ITS RIDGE
AXIS WILL PASS THRU AFTER MIDNIGHT. A CLIPPER WILL FORM OVER WRN
CANADA TONIGHT AND AN ASSOCIATED WARM FRONT WILL DEVELOP SOUTHWARD
INTO THE REGION.
NOW: TEMPS CONT STRUGGLING TO DROP. TEMPS ARE STILL IN THE 30S
ACROSS THE ENTIRE FCST AREA. SO LOW TEMPS WERE RAISED SVRL DEGS
FROM THE 4 PM FCST.
EARLY THIS MORNING: LOTS OF WRAP AROUND CLOUDS IN CYCLONIC NW
FLOW.
TODAY: CONTINUED WINDY. NW WINDS WILL GUST 30-35 KTS IN DOWNWARD
TRANSFER AS THE BOUNDARY LAYER BECOMES UNSTABLE. POTENTIAL PEAK
GUSTS AS HIGH AS 38 KTS PER BUFKIT MIXING ALGORITHM. USED GFS WITH
ITS DEEPER MIXING.
THE RAP/NAM/GFS AGREE THE WRN FRINGE OF THE WRAP-AROUND CLOUDS
WILL GRADUALLY SHIFT E OF THE FCST AREA LEAVING SKIES SUNNY.
SIMULATED IR IMAGERY FROM THE 4 KM NAM NEST SUGGESTS SOME PATCHES
OF CIRROSTRATUS WILL BEGIN MOVING IN FROM THE NW LATE AND THIS
IS REASONABLE BASED ON CURRENT SATELLITE...WITH THE NRN ROCKIES
SHORTWAVE TROF DIVING TO OUR W.
INTERNAL VERIFICATION SHOWS WE HAVE BEEN RUNNING TOO COOL ON HIGH
TEMPS RECENTLY. SO USED 06Z RAP TO NUDGE TEMPS UPWARD SLIGHTLY.
HIGHS WILL STILL BE 5-10F COLDER THAN NORMAL FOR MOST OF THE FCST
AREA.
TONIGHT: WINDS DROP OFF EARLY EVENING WITH DECOUPLING. PATCHES OF
CIRROSTRATUS CONT TO DRIFT THRU BUT SHOULD BE NO WORSE THAN
P/CLOUDY.
USED THE WEIGHTED CONSENSUS OF THE 3 BEST-VERIFYING TEMP GUIDES
FOR LOWS...WHICH FAVORED THE COLDER MOS TEMPS. JUST SLIGHTLY
COLDER THAN NORMAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 159 AM CST MON NOV 24 2014
THIS SECTION WILL UPDATE AROUND 4 AM.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z MON NIGHT)
ISSUED AT 1159 PM CST SUN NOV 23 2014
OVERNIGHT: VARIABLE MULTI-LAYERED VFR CLOUDS MOSTLY BETWEEN 4-10K
FT. THERE IS A LOW PROBABILITY FOR A TEMPO MVFR CEILING BETWEEN
2500-3000 FT...ESPECIALLY AT GRI. CONFIDENCE IS NOT HIGH ENOUGH
TO INCLUDE IN THE TAFS. NW WINDS WILL BE HIGHLY VARIABLE IN SPEEDS
AND GUSTS. DURING TIMES WHEN WINDS DECREASE TO 10-15 KTS...SOME
LLWS IS PROBABLE. OTHERWISE...WINDS WILL GUST UP TO 35 KTS AT
TIMES. CONFIDENCE: MEDIUM
MON: MULTI-LAYERED VFR CIGS WILL DIMINISH WITH GRADUAL CLEARING
DURING THE MORNING HRS. NW WINDS WILL GUST UP TO 30 KTS.
CONFIDENCE: HIGH
MON EVE: VFR WITH CIRROSTRATUS CIGS INVADING. NW WINDS DIMINISH
AND SETTLE AROUND 10 KTS. CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1255 AM EST MON NOV 24 2014
.SYNOPSIS...
MILD TEMPERATURES WITH UNSETTLED WEATHER IS EXPECTED TONIGHT INTO
MONDAY AS A WARM FRONT CROSSES THE AREA. A COLD FRONT WILL CROSS
THE COAST MONDAY NIGHT AND STALL OFFSHORE TUESDAY. COOL AND WET
CONDITIONS ARE EXPECTED WEDNESDAY...AS DEEPENING LOW PRESSURE
MOVES NORTH ALONG THE STALLED FRONT AND SKIRTS THE COAST. SKIES
WILL CLEAR OUT ON THANKSGIVING...WITH TEMPERATURES RUNNING SEVERAL
DEGREES BELOW NORMAL INTO THE COMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1 AM MONDAY...LINE OF STRONG CONVECTION HAS MOVED OFFSHORE
AND OTHER THAN A FEW LIGHT SHOWERS IT LOOKS LIKE WE ARE IN FOR A
LULL IN THE ACTION FOR THE REMAINDER OF THE OVERNIGHT PERIOD. HAVE
UPDATED FORECAST ACCORDINGLY. PREVIOUS DISCUSSION FOLLOWS:
TWO CONVECTIVE BANDS ARE CROSSING THE AREA CURRENTLY AND SHOULD
DROP A GENERAL 0.4 TO 0.5 INCHES OF RAIN WITH EMBEDDED HEAVIER
AMOUNTS. AT THE SURFACE THE WARM FRONT APPEARS TO BE THROUGH
FLORENCE AND IS APPROACHING MYRTLE BEACH. LATEST HIGH- RES
MODELING INDICATES THE BOUNDARY SHOULD MOVE OR JUMP NORTHWARD VERY
QUICKLY WITH ALL OF OUR FORECAST AREA WITHIN THE WARM SECTOR BY
MIDNIGHT.
CONCERNING SEVERE WEATHER POTENTIAL...INSTABILITY REMAINS THE
LIMITING FACTOR. IN ORDER FOR CONVECTION TO BECOME SURFACE-BASED
ANALYSIS OF THE 03Z SOUNDINGS FROM THE 23Z RUC INDICATES WE NEED A
SURFACE TEMP/DEWPOINT OF 69 DEGREES F...EQUIVALENT TO A SURFACE
THETA-E VALUE OF 333K. ANYTHING LESS THAN THIS SHIFTS THE CONVECTIVE
ORIGIN POINT UPWARD OFF THE SURFACE WITH A CORRESPONDING REDUCTION
IN SEVERE WEATHER RISK. 02/03Z SURFACE OBS INDICATE WE DO NOT HAVE
REQUISITE THETA-E VALUES IN PLACE AT THE SURFACE TO SUPPORT
SURFACE-BASED CONVECTION...AND THEREFORE ALL OF THE CURRENT ACTIVITY
LIKELY REMAINS ELEVATED. THE DRY SLOT IS APPROACHING FROM THE WEST
AND SHOULD SPELL AN END TO THE SOLID PRECIPITATION SHIELD OVER THE
NEXT FEW HOURS...WITH ONLY SCATTERED SHOWERS CONTINUING LATE TONIGHT
INTO MONDAY MORNING. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
A WAVE OF HEAVY SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS EASTERN
GEORGIA AND NOW CROSSING THE SANTEE RIVER INTO SOUTH CAROLINA WILL
MOVE ACROSS THE EASTERN CAROLINAS SHORTLY. RAINFALL EARLIER TODAY
WAS MAINLY DUE TO ISENTROPIC UPGLIDE AS MOIST WARM ADVECTION WITHIN
THE 850-700 MB LAYER PRODUCED GENTLE UNIFORM LIFT. THE BATCH OF
PRECIPITATION TO BEGIN SHORTLY IS BEING FORCED BY EXCELLENT UPPER
DIVERGENCE WITHIN THE RIGHT-ENTRANCE REGION OF A 250 MB JET STREAK
MOVING NORTH THROUGH WESTERN NC/VA THIS EVENING.
A WARM FRONT CURRENTLY EXTENDING FROM NEAR BEAUFORT SC WESTWARD
ACROSS AUGUSTA GA WILL MOVE NORTHWARD AT A GOOD CLIP OVER THE NEXT
FEW HOURS...BRINGING A NEARLY TROPICAL AIRMASS NORTHWARD ACROSS THE
AREA. MODEST SURFACE BASED INSTABILITY ON THE ORDER OF 300-600 J/KG
SHOULD DEVELOP ACROSS AREAS WHERE TEMP/DEWPOINTS ARE ABLE TO REACH
70 DEGREES F. WHEN COMBINED WITH 0-1 KM HELICITY VALUES OF 400-600
M^2/S^2 THE POTENTIAL EXISTS FOR SOME OF THESE CELLS TO ROTATE. I
FEEL THE OVERALL SEVERE WEATHER RISK REMAINS LOW SINCE SURFACE-BASED
INSTABILITY SHOULD NOT DEVELOP UNTIL THE WARM FRONT ARRIVES AND
WINDS BELOW 925 MB VEER MORE SOUTHWESTERLY. THIS WILL MAKE THE
VERTICAL WIND PROFILE UNIDIRECTIONAL REDUCING THE POTENTIAL FOR
TORNADIC STORMS. IF TEMPS/DEWPOINTS REMAIN BELOW 70 F MODEL FORECAST
SOUNDINGS INDICATE THE BOUNDARY LAYER WOULD BE STABLE WITH
CONVECTION REMAINING ELEVATED AND THEREFORE INHERENTLY LESS
DANGEROUS. WE WILL MONITOR RADAR CLOSELY THROUGH THE EVENING
WATCHING FOR ANYTHING THAT MIGHT WARRANT A STATEMENT OR SEVERE
WEATHER WARNING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...ODDLY MILD CONDITIONS TO ENGULF THE EASTERN
CAROLINAS MONDAY WITH STRONG WARM AIR ADVECTION PATTERN IN PLACE
AND A COLD FRONT AND UPPER TROUGH WEST OF THE FORECAST AREA. 65-70
TEMPERATURE RANGE TO GREET MOST AREAS DAYBREAK MONDAY...AS MAXIMUM
TEMPERATURES CLIMB INTO THE MIDDLE AND UPPER 70S...LIKELY UNDER A
CANOPY OF CLOUDS DUE TO EXTENT OF UPSTREAM CONVECTION. THE LOW-LVL
WIND FIELD REMAINS STRONG MONDAY...AND ANY SURFACE HEATING MONDAY
AFTERNOON COULD LEAD TO CONVECTION CAPABLE OF DAMAGING WIND...AND
EVEN SHOWERS WILL BRING LOCALLY STRONGER GUSTS. SPC MAINTAIN A LOW
END RISK NEAR THE COAST AHEAD OF A COLD FRONT.
TUESDAY A POST-FRONTAL DAY WHERE WEATHER HAZARDS WANE. THE UPSTREAM
TROUGH ALIGN HOWEVER WILL SUPPORT MORE IMPULSES RISING OUT OF THE
GULF. CYCLOGENESIS OFFSHORE OF NORTHERN FLORIDA OCCUR VERY LATE IN
THE PERIOD AND BECOME A WEATHER PLAYER BEYOND DAYBREAK WEDNESDAY AND
POP VALUES DO GRADUALLY RAMP UP TO THIS FEATURE LATE TUESDAY.
RECORD HIGH TEMPS MONDAY ARE ILM 79...FLO 83...CRE 76...LBT 78.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 4 PM SUNDAY...MAIN FOCUS FOR THE PERIOD REMAINS LOW PRESSURE
PASSING JUST OFF THE COAST WED. SHORTWAVE CROSSING THE WESTERN GULF
LATE TUE WILL ENHANCE SURFACE WAVE JUST OFF THE FL GULF COAST WED
MORNING. THIS LOW WILL TRAVEL NORTHEAST ALONG A STALLED BOUNDARY WED
INTO WED NIGHT WITH DEEP MOISTURE SPREADING OVER THE CAROLINAS. LOW
WILL REMAIN EAST OF THE COASTAL WATERS WITH INCREASING NORTHERLY
FLOW...CLOUD COVER...AND PERIODS OF HEAVY RAIN KEEPING TEMPERATURES
IN THE 40S FOR MUCH OF THE AREA. PRESENCE OF DEEP MOISTURE AND
STRONG LIFT/DIVERGENCE ALOFT WILL ENSURE PLENTY OF RAIN FALLS ACROSS
THE AREA WED. MID LEVEL TROUGH MOVES INTO THE AREA WED EVENING WITH
SIGNIFICANT AMOUNT OF DRY AIR MOVING IN...ENDING THE RAIN THREAT.
SUBTLE MID LEVEL TROUGHING IN THE WAKE OF THE EXITING SYSTEM REMAINS
OVER THE SOUTHEAST FRI...PUSHING A DRY COLD FRONT ACROSS THE AREA.
MID LEVEL PATTERN FLATTENS OUT FOR THE WEEKEND AND FLOW ALOFT
BECOMES PROGRESSIVE. HIGH PRESSURE BUILDING IN FOR THE WEEKEND
QUICKLY SHIFTS OFFSHORE WITH RETURN FLOW DEVELOPING AND TEMPS
CLIMBING BACK CLOSE TO CLIMO.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...A MIXTURE OF MVFR/IFR/POSSIBLE LIFR WILL PERSIST THROUGH
THE VALID TAF PERIOD AS LOW CIGS AND FOG AFFECT THE AREA.
THE REMAINDER OF THE RAINFALL CONTINUES TO PUSH EASTWARD ACROSS THE
AREA...TAPERING OF WEST TO EAST. HOWEVER...WILL CONTINUE TO SEE
DETERIORATED CONDITIONS AS LOW CIGS AND FOG PERSISTS CREATING
MVFR/IFR ALONG WITH PERIODS OF LIFR POSSIBLE. AFTER DAYBREAK...WITH
GUSTY SOUTHWEST WINDS...LOW CIGS WITH AREAS OF FOG WILL PERSIST
THROUGH MUCH OF THE DAY...THUS EXPECT MVFR/IFR. COULD SEE BRIEF
IMPROVEMENT TO VFR IN SOME LOCATIONS...BUT OVERALL EXPECT MVFR/IFR.
ISOLATED -SHRA ARE POSSIBLE THROUGHOUT THE DAY..
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AFTERNOON
THROUGH WEDNESDAY NEAR THE COAST...WITH OCCASIONAL SHOWERS AND
MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY NIGHT...THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1 AM MONDAY...SMALL CRAFT ADVISORY IN EFFECT ALTHOUGH ALL
STRONG CONVECTION HAS MOVED EAST OF THE WATERS. FORECAST UPDATED
ACCORDINGLY. PREVIOUS DISCUSSION FROM 10 PM FOLLOWS:
THE WARM FRONT APPEARS TO BE APPROACHING THE MYRTLE BEACH VICINITY
AS WINDS HAVE SHIFTED IN GEORGETOWN BUT SOUTHEAST WINDS CONTINUE IN
MYRTLE BEACH AND POINTS NORTHWARD ALONG THE COAST. GUSTS OUT AT THE
FRYING PAN SHOALS BUOY REMAIN ABOVE GALE-FORCE...AND WINDS AT THE
BEACHES NORTH OF CAPE FEAR ARE APPROACHING GALE FORCE WITH 33 KNOTS
RECENTLY REPORTED ON TOPSAIL ISLAND (MESONET) AND 30 KNOTS AT MERCER
PIER ON WRIGHTSVILLE BEACH. SEAS ARE ALMOST FULLY DEVELOPED FOR THIS
FETCH AND SPEED...13 FEET OUT AT FRYING PAN SHOALS...10 FEET AT THE
HARBOR BUOY SOUTH OF BALD HEAD ISLAND...AND 9 FEET AT THE NEARSHORE
WRIGHTSVILLE BEACH BUOY. NO SIGNIFICANT CHANGES ARE NEEDED FOR THIS
LATE-EVENING UPDATE. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
THE WARM FRONT HAS MOVED THROUGH SAVANNAH AND IS RACING UP THE COAST
AT A PRETTY GOOD CLIP. MOST RECENT MODELS ARE TOO FAST WITH THE
FRONTAL TIMING...BUT AMONG THOSE THAT SEEM TO HAVE A GOOD HANDLE
(21Z HRRR, 22Z RUC, 12Z ECMWF) THE LATEST THINKING IS FOR FRONT TO
CROSS THE SANTEE RIVER 8-9 PM...CAPE FEAR AROUND 11 PM...AND TO BE
NORTH OF TOPSAIL ISLAND BY MIDNIGHT. THE FRONT WILL BE HERALDED BY A
SHIFT FROM SOUTHEAST TO SOUTH WINDS. ANOTHER HEAVY WAVE OF SHOWERS
AND EMBEDDED THUNDERSTORMS IN EASTERN GEORGIA AND NOW CROSSING THE
SAVANNAH RIVER INTO SOUTH CAROLINA SHOULD ARRIVE IN THE NEXT COUPLE
OF HOURS. HEAVY RAINFALL AND LIGHTNING ARE THE LARGEST THREATS.
WINDS HAVE BEEN GUSTING OVER GALE FORCE AT THE FRYING PAN SHOALS
BUOY FOR THE PAST THREE HOURS. BUOY 41004 EAST OF CHARLESTON IS IN
THE SAME ENVIRONMENT AND HAS ALSO GUSTED OVER GALE FORCE EARLY THIS
EVENING. CLOSER TO SHORE THE COLDER OCEAN WATER TEMPERATURE ON THE
SHALLOW CONTINENTAL SHELF IS INDUCED A MUCH MORE STABLE ATMOSPHERIC
BOUNDARY LAYER WITH LESS WIND ABLE TO MIX DOWN FROM ALOFT. DESPITE
WINDS JUST 1000 FEET ABOVE THE SURFACE EXPECTED TO REACH 50 KNOTS
IN JUST A COUPLE HOURS...WIND SPEEDS DOWN AT THE OCEAN SURFACE
SHOULD REMAIN 20-30 KNOTS ACROSS THE SC WATERS...AND 25-35 KNOTS
ACROSS THE NC WATERS WITH A HIGHER GUSTS WELL AWAY FROM SHORE WHERE
WATER TEMPERATURES ARE STILL IN THE RELATIVELY MILD MID 60S.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...MONDAY MARINE CONDITIONS REMAIN DANGEROUS WITH
SEAS OF 5-9 FEET LIKELY AND HIGHEST AWAY FROM SHORE AND NEAR THE
FRYING PAN SHOALS. 20-30 KT SSW WINDS MONDAY...BECOMING WEST LATE
TUESDAY NIGHT OR EARLY MONDAY AS A SURFACE COLD FRONT MOVES ACROSS
THE WATERS. STRONG TSTMS REMAIN POSSIBLE MONDAY THROUGH TUESDAY
MORNING ON THE 0-20 NM WATERS. LARGE SSW-SE WAVES WILL MAKE UP THE
SEA SPECTRUM IN MIXED WAVE PERIODS OF 5-6 SECONDS AND 8-9 SECONDS.
IMPROVING CONDITIONS TUESDAY ALTHOUGH WAVE RECOVERY WILL STILL BE
UNDERWAY EARLY TUESDAY.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 4 PM SUNDAY...PERIOD OF HEADLINES SEEMS LIKELY WED INTO
WED NIGHT AS DEEPENING LOW PRESSURE PASSES JUST EAST OF THE
WATERS. WINDS WILL BACK FROM NORTH-NORTHEAST TO WEST WED INTO WED
NIGHT AS THE LOW LIFTS NORTHEAST. SPEEDS WILL PEAK IN THE 20 TO 25
KT RANGE WITH SEAS NEAR 20 NM FLIRTING WITH 6 TO 7 FT. OFFSHORE
FLOW WEAKENS LATE WED NIGHT INTO THU AS SURFACE HIGH TO THE WEST
BUILDS EAST. SPEEDS REMAIN CLOSE TO 15 KT THU WITH A SLIGHT
INCREASE FRI AS DRY COLD FRONT PASSES AND BRIEF COLD ADVECTION
DEVELOPS. AN OFFSHORE COMPONENT WILL KEEP SEAS WITHIN 20 NM IN THE
2 TO 4 FT RANGE THU AND FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...MJC
NEAR TERM...REK/TRA/MBB
SHORT TERM...MJC
LONG TERM...III
AVIATION...SGL
MARINE...MJC/REK/TRA/III/MBB
AREA FORECAST DISCUSSION...UPDATED
NWS WILMINGTON NC
1158 PM EST SUN NOV 23 2014
.SYNOPSIS...
MILD TEMPERATURES WITH UNSETTLED WEATHER IS EXPECTED TONIGHT INTO
MONDAY AS A WARM FRONT CROSSES THE AREA. A COLD FRONT WILL CROSS
THE COAST MONDAY NIGHT AND STALL OFFSHORE TUESDAY. COOL AND WET
CONDITIONS ARE EXPECTED WEDNESDAY...AS DEEPENING LOW PRESSURE MOVES
NORTH ALONG THE STALLED FRONT AND SKIRTS THE COAST. SKIES WILL
CLEAR OUT ON THANKSGIVING...WITH TEMPERATURES RUNNING SEVERAL
DEGREES BELOW NORMAL INTO THE COMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1000 PM SUNDAY...TWO CONVECTIVE BANDS ARE CROSSING THE AREA
CURRENTLY AND SHOULD DROP A GENERAL 0.4 TO 0.5 INCHES OF RAIN WITH
EMBEDDED HEAVIER AMOUNTS. AT THE SURFACE THE WARM FRONT APPEARS TO
BE THROUGH FLORENCE AND IS APPROACHING MYRTLE BEACH. LATEST HIGH-RES
MODELING INDICATES THE BOUNDARY SHOULD MOVE OR JUMP NORTHWARD VERY
QUICKLY WITH ALL OF OUR FORECAST AREA WITHIN THE WARM SECTOR BY
MIDNIGHT.
CONCERNING SEVERE WEATHER POTENTIAL...INSTABILITY REMAINS THE
LIMITING FACTOR. IN ORDER FOR CONVECTION TO BECOME SURFACE-BASED
ANALYSIS OF THE 03Z SOUNDINGS FROM THE 23Z RUC INDICATES WE NEED A
SURFACE TEMP/DEWPOINT OF 69 DEGREES F...EQUIVALENT TO A SURFACE
THETA-E VALUE OF 333K. ANYTHING LESS THAN THIS SHIFTS THE CONVECTIVE
ORIGIN POINT UPWARD OFF THE SURFACE WITH A CORRESPONDING REDUCTION
IN SEVERE WEATHER RISK. 02/03Z SURFACE OBS INDICATE WE DO NOT HAVE
REQUISITE THETA-E VALUES IN PLACE AT THE SURFACE TO SUPPORT
SURFACE-BASED CONVECTION...AND THEREFORE ALL OF THE CURRENT ACTIVITY
LIKELY REMAINS ELEVATED. THE DRY SLOT IS APPROACHING FROM THE WEST
AND SHOULD SPELL AN END TO THE SOLID PRECIPITATION SHIELD OVER THE
NEXT FEW HOURS...WITH ONLY SCATTERED SHOWERS CONTINUING LATE TONIGHT
INTO MONDAY MORNING. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
A WAVE OF HEAVY SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS EASTERN
GEORGIA AND NOW CROSSING THE SANTEE RIVER INTO SOUTH CAROLINA WILL
MOVE ACROSS THE EASTERN CAROLINAS SHORTLY. RAINFALL EARLIER TODAY
WAS MAINLY DUE TO ISENTROPIC UPGLIDE AS MOIST WARM ADVECTION WITHIN
THE 850-700 MB LAYER PRODUCED GENTLE UNIFORM LIFT. THE BATCH OF
PRECIPITATION TO BEGIN SHORTLY IS BEING FORCED BY EXCELLENT UPPER
DIVERGENCE WITHIN THE RIGHT-ENTRANCE REGION OF A 250 MB JET STREAK
MOVING NORTH THROUGH WESTERN NC/VA THIS EVENING.
A WARM FRONT CURRENTLY EXTENDING FROM NEAR BEAUFORT SC WESTWARD
ACROSS AUGUSTA GA WILL MOVE NORTHWARD AT A GOOD CLIP OVER THE NEXT
FEW HOURS...BRINGING A NEARLY TROPICAL AIRMASS NORTHWARD ACROSS THE
AREA. MODEST SURFACE BASED INSTABILITY ON THE ORDER OF 300-600 J/KG
SHOULD DEVELOP ACROSS AREAS WHERE TEMP/DEWPOINTS ARE ABLE TO REACH
70 DEGREES F. WHEN COMBINED WITH 0-1 KM HELICITY VALUES OF 400-600
M^2/S^2 THE POTENTIAL EXISTS FOR SOME OF THESE CELLS TO ROTATE. I
FEEL THE OVERALL SEVERE WEATHER RISK REMAINS LOW SINCE SURFACE-BASED
INSTABILITY SHOULD NOT DEVELOP UNTIL THE WARM FRONT ARRIVES AND
WINDS BELOW 925 MB VEER MORE SOUTHWESTERLY. THIS WILL MAKE THE
VERTICAL WIND PROFILE UNIDIRECTIONAL REDUCING THE POTENTIAL FOR
TORNADIC STORMS. IF TEMPS/DEWPOINTS REMAIN BELOW 70 F MODEL FORECAST
SOUNDINGS INDICATE THE BOUNDARY LAYER WOULD BE STABLE WITH
CONVECTION REMAINING ELEVATED AND THEREFORE INHERENTLY LESS
DANGEROUS. WE WILL MONITOR RADAR CLOSELY THROUGH THE EVENING
WATCHING FOR ANYTHING THAT MIGHT WARRANT A STATEMENT OR SEVERE
WEATHER WARNING.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...ODDLY MILD CONDITIONS TO ENGULF THE EASTERN
CAROLINAS MONDAY WITH STRONG WARM AIR ADVECTION PATTERN IN PLACE
AND A COLD FRONT AND UPPER TROUGH WEST OF THE FORECAST AREA. 65-70
TEMPERATURE RANGE TO GREET MOST AREAS DAYBREAK MONDAY...AS MAXIMUM
TEMPERATURES CLIMB INTO THE MIDDLE AND UPPER 70S...LIKELY UNDER A
CANOPY OF CLOUDS DUE TO EXTENT OF UPSTREAM CONVECTION. THE LOW-LVL
WIND FIELD REMAINS STRONG MONDAY...AND ANY SURFACE HEATING MONDAY
AFTERNOON COULD LEAD TO CONVECTION CAPABLE OF DAMAGING WIND...AND
EVEN SHOWERS WILL BRING LOCALLY STRONGER GUSTS. SPC MAINTAIN A LOW
END RISK NEAR THE COAST AHEAD OF A COLD FRONT.
TUESDAY A POST-FRONTAL DAY WHERE WEATHER HAZARDS WANE. THE UPSTREAM
TROUGH ALIGN HOWEVER WILL SUPPORT MORE IMPULSES RISING OUT OF THE
GULF. CYCLOGENESIS OFFSHORE OF NORTHERN FLORIDA OCCUR VERY LATE IN
THE PERIOD AND BECOME A WEATHER PLAYER BEYOND DAYBREAK WEDNESDAY AND
POP VALUES DO GRADUALLY RAMP UP TO THIS FEATURE LATE TUESDAY.
RECORD HIGH TEMPS MONDAY ARE ILM 79...FLO 83...CRE 76...LBT 78.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 4 PM SUNDAY...MAIN FOCUS FOR THE PERIOD REMAINS LOW PRESSURE
PASSING JUST OFF THE COAST WED. SHORTWAVE CROSSING THE WESTERN GULF
LATE TUE WILL ENHANCE SURFACE WAVE JUST OFF THE FL GULF COAST WED
MORNING. THIS LOW WILL TRAVEL NORTHEAST ALONG A STALLED BOUNDARY WED
INTO WED NIGHT WITH DEEP MOISTURE SPREADING OVER THE CAROLINAS. LOW
WILL REMAIN EAST OF THE COASTAL WATERS WITH INCREASING NORTHERLY
FLOW...CLOUD COVER...AND PERIODS OF HEAVY RAIN KEEPING TEMPERATURES
IN THE 40S FOR MUCH OF THE AREA. PRESENCE OF DEEP MOISTURE AND
STRONG LIFT/DIVERGENCE ALOFT WILL ENSURE PLENTY OF RAIN FALLS ACROSS
THE AREA WED. MID LEVEL TROUGH MOVES INTO THE AREA WED EVENING WITH
SIGNIFICANT AMOUNT OF DRY AIR MOVING IN...ENDING THE RAIN THREAT.
SUBTLE MID LEVEL TROUGHING IN THE WAKE OF THE EXITING SYSTEM REMAINS
OVER THE SOUTHEAST FRI...PUSHING A DRY COLD FRONT ACROSS THE AREA.
MID LEVEL PATTERN FLATTENS OUT FOR THE WEEKEND AND FLOW ALOFT
BECOMES PROGRESSIVE. HIGH PRESSURE BUILDING IN FOR THE WEEKEND
QUICKLY SHIFTS OFFSHORE WITH RETURN FLOW DEVELOPING AND TEMPS
CLIMBING BACK CLOSE TO CLIMO.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...A MIXTURE OF MVFR/IFR/POSSIBLE LIFR EXPECT TONIGHT AND
THROUGH THE OVERNIGHT HOURS AS UNSETTLED WEATHER ALLOWS FOR
SHRA/TSRA TO CREATE PERIODS OF HEAVY RAIN AND WIND...ALONG WITH LOW
CIGS AND FOG...TO AFFECT THE AREA. RAIN TAPERS OFF INTO THE EARLY
MORNING HOURS...THOUGH AREAS OF LOW CIGS AND FOG ARE ANTICIPATED
THROUGH THE PERIOD...WITH IMPROVEMENT TO VFR POSSIBLE INLAND DURING
THE AFTERNOON HOURS ON MONDAY.
LATEST RADAR IMAGERY DEPICTS LIGHT -SHRA MOVING ACROSS THE AREA THIS
EVENING WHILE OBS ARE REPORTING LOW CIGS AND AREAS OF FOG CREATING
MVFR/IFR AT ALL TAF SITES. WHILE ACTIVITY IS LIGHT NOW...SHOWERS AND
THUNDERSTORMS ARE POSSIBLE LATER TONIGHT INTO THE EARLY OVERNIGHT
HOURS...WITH ISOLATED SEVERE STORMS POSSIBLE. WITH ANY STRONGER
STORM COULD SEE HEAVY RAINFALL. AS FOR WINDS EXPECT SOUTHEASTERLY
AROUND 10 KTS WITH GUSTS UP TO 20 KTS...AND HIGHER GUSTS POSSIBLE IN
ANY TSRA. LATE OVERNIGHT...ANY SHRA/TSRA WILL TAPER OFF...BUT WILL
CONTINUING TO SEE DETERIORATED CONDITIONS AS LOW CIGS AND FOG
PERSISTS. WHILE LIFR CANNOT BE RULE OUT...OVERALL ANTICIPATE
MVFR/IFR. INTO MONDAY...WITH GUSTY SOUTHWEST WINDS...LOW CIGS WITH
AREAS OF FOG WILL PERSIST...THUS EXPECT MVFR/IFR. COULD SEE
IMPROVEMENT TO VFR IN THE AFTERNOON HOURS IN SPOTS...BUT TOWARDS THE
END OF THE PERIOD CONDITIONS WILL DETERIORATE BACK TO MVFR/IFR.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AFTERNOON
THROUGH WEDNESDAY NEAR THE COAST...WITH OCCASIONAL SHOWERS AND
MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY NIGHT...THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1158 PM SUNDAY...GALE WARNING IS EXPIRING AT MIDNIGHT FOR THE
NC WATERS...REPLACED BY A SMALL CRAFT ADVISORY. ANY RESIDUAL STRONG
WINDS WILL BE ASSOCIATED WITH CONVECTION AND WILL BE HANDLED BY
SPECIAL MARINE WARNINGS RATHER THAN SYNOPTIC GALE PRODUCTS. PREVIOUS
DISCUSSION FROM 1000 PM FOLLOWS...
THE WARM FRONT APPEARS TO BE APPROACHING THE MYRTLE BEACH VICINITY
AS WINDS HAVE SHIFTED IN GEORGETOWN BUT SOUTHEAST WINDS CONTINUE IN
MYRTLE BEACH AND POINTS NORTHWARD ALONG THE COAST. GUSTS OUT AT THE
FRYING PAN SHOALS BUOY REMAIN ABOVE GALE-FORCE...AND WINDS AT THE
BEACHES NORTH OF CAPE FEAR ARE APPROACHING GALE FORCE WITH 33 KNOTS
RECENTLY REPORTED ON TOPSAIL ISLAND (MESONET) AND 30 KNOTS AT MERCER
PIER ON WRIGHTSVILLE BEACH. SEAS ARE ALMOST FULLY DEVELOPED FOR THIS
FETCH AND SPEED...13 FEET OUT AT FRYING PAN SHOALS...10 FEET AT THE
HARBOR BUOY SOUTH OF BALD HEAD ISLAND...AND 9 FEET AT THE NEARSHORE
WRIGHTSVILLE BEACH BUOY. NO SIGNIFICANT CHANGES ARE NEEDED FOR THIS
LATE-EVENING UPDATE. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
THE WARM FRONT HAS MOVED THROUGH SAVANNAH AND IS RACING UP THE COAST
AT A PRETTY GOOD CLIP. MOST RECENT MODELS ARE TOO FAST WITH THE
FRONTAL TIMING...BUT AMONG THOSE THAT SEEM TO HAVE A GOOD HANDLE
(21Z HRRR, 22Z RUC, 12Z ECMWF) THE LATEST THINKING IS FOR FRONT TO
CROSS THE SANTEE RIVER 8-9 PM...CAPE FEAR AROUND 11 PM...AND TO BE
NORTH OF TOPSAIL ISLAND BY MIDNIGHT. THE FRONT WILL BE HERALDED BY A
SHIFT FROM SOUTHEAST TO SOUTH WINDS. ANOTHER HEAVY WAVE OF SHOWERS
AND EMBEDDED THUNDERSTORMS IN EASTERN GEORGIA AND NOW CROSSING THE
SAVANNAH RIVER INTO SOUTH CAROLINA SHOULD ARRIVE IN THE NEXT COUPLE
OF HOURS. HEAVY RAINFALL AND LIGHTNING ARE THE LARGEST THREATS.
WINDS HAVE BEEN GUSTING OVER GALE FORCE AT THE FRYING PAN SHOALS
BUOY FOR THE PAST THREE HOURS. BUOY 41004 EAST OF CHARLESTON IS IN
THE SAME ENVIRONMENT AND HAS ALSO GUSTED OVER GALE FORCE EARLY THIS
EVENING. CLOSER TO SHORE THE COLDER OCEAN WATER TEMPERATURE ON THE
SHALLOW CONTINENTAL SHELF IS INDUCED A MUCH MORE STABLE ATMOSPHERIC
BOUNDARY LAYER WITH LESS WIND ABLE TO MIX DOWN FROM ALOFT. DESPITE
WINDS JUST 1000 FEET ABOVE THE SURFACE EXPECTED TO REACH 50 KNOTS
IN JUST A COUPLE HOURS...WIND SPEEDS DOWN AT THE OCEAN SURFACE
SHOULD REMAIN 20-30 KNOTS ACROSS THE SC WATERS...AND 25-35 KNOTS
ACROSS THE NC WATERS WITH A HIGHER GUSTS WELL AWAY FROM SHORE WHERE
WATER TEMPERATURES ARE STILL IN THE RELATIVELY MILD MID 60S.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...MONDAY MARINE CONDITIONS REMAIN DANGEROUS WITH
SEAS OF 5-9 FEET LIKELY AND HIGHEST AWAY FROM SHORE AND NEAR THE
FRYING PAN SHOALS. 20-30 KT SSW WINDS MONDAY...BECOMING WEST LATE
TUESDAY NIGHT OR EARLY MONDAY AS A SURFACE COLD FRONT MOVES ACROSS
THE WATERS. STRONG TSTMS REMAIN POSSIBLE MONDAY THROUGH TUESDAY
MORNING ON THE 0-20 NM WATERS. LARGE SSW-SE WAVES WILL MAKE UP THE
SEA SPECTRUM IN MIXED WAVE PERIODS OF 5-6 SECONDS AND 8-9 SECONDS.
IMPROVING CONDITIONS TUESDAY ALTHOUGH WAVE RECOVERY WILL STILL BE
UNDERWAY EARLY TUESDAY.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 4 PM SUNDAY...PERIOD OF HEADLINES SEEMS LIKELY WED INTO
WED NIGHT AS DEEPENING LOW PRESSURE PASSES JUST EAST OF THE
WATERS. WINDS WILL BACK FROM NORTH-NORTHEAST TO WEST WED INTO WED
NIGHT AS THE LOW LIFTS NORTHEAST. SPEEDS WILL PEAK IN THE 20 TO 25
KT RANGE WITH SEAS NEAR 20 NM FLIRTING WITH 6 TO 7 FT. OFFSHORE
FLOW WEAKENS LATE WED NIGHT INTO THU AS SURFACE HIGH TO THE WEST
BUILDS EAST. SPEEDS REMAIN CLOSE TO 15 KT THU WITH A SLIGHT
INCREASE FRI AS DRY COLD FRONT PASSES AND BRIEF COLD ADVECTION
DEVELOPS. AN OFFSHORE COMPONENT WILL KEEP SEAS WITHIN 20 NM IN THE
2 TO 4 FT RANGE THU AND FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...MJC/TRA
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...III
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1146 PM EST SUN NOV 23 2014
.SYNOPSIS...
DEEPENING LOW PRESSURE WILL TRACK FROM THE LOWER MISSISSIPPI
VALLEY ACROSS THE GREAT LAKES ON MONDAY PUSHING A STRONG COLD
FRONT ACROSS THE AREA ON MONDAY WITH A SECOND COLD FRONT ON
TUESDAY. A WEAK LOW PRESSURE AREA AND A COLD FRONT WILL CROSS THE
LOWER GREAT LAKES LATER WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
WINDS WILL INCREASE OVERNIGHT AS LOW PRESSURE CONTINUES TO DEEPEN
AS IT TRACKS NORTH THROUGH THE CENTRAL GREAT LAKES. A WIND
ADVISORY REMAINS IN EFFECT FOR THE NORTHEAST LAKESHORE WITH THE
STRONGEST WINDS EXPECTED ACROSS NORTHERN ERIE PA COUNTY NEAR THE LAKESHORE.
THE HRRR SHOWS WINDS PEAKING BY ABOUT 2 AM IN THIS AREA THEN
DECREASING LATE TONIGHT AS THE WARM FRONT PASSES TO THE NORTH. EXPECT
THE STRONG WIND IN THE OTHER ADVISORY AREAS TO BE SOMEWHAT MORE
LOCALIZED WHERE DOWNSLOPING IS ENHANCED OFF THE HIGHER TERRAIN
AND SOME HELP FROM SHORELINE CONVERGENCE. WE HAVE ALREADY HAD A
WIND GUST TO 47 MPH AT LPR AND 41 MPH AT MFD. THESE FEW STRAY
GUSTS ABOVE 40 MPH ARE POSSIBLE OVERNIGHT BUT THINKING THEY WILL
STAY LIMITED ENOUGH TO NOT NEED TO EXPAND THE ADVISORY FOR THE
OVERNIGHT HOURS.
AS FOR THE HIGH WIND WATCH FOR MONDAY...A CORRIDOR OF THE
STRONGEST WINDS IS EXPECTED ACROSS NORTHWEST AND NORTH CENTRAL
OHIO BEHIND THE FRONT WHERE GUSTS OF 50-60 MPH ARE POSSIBLE.
ELSEWHERE IT LOOKS LIKE THE PEAK GUSTS MAY ONLY OCCUR WITH SHOWERS
SO COULD POSSIBLY BE HANDLED WITH A WIND ADVISORY AND SHORT FUSED CONVECTIVE
PRODUCTS IF NECESSARY. ALWAYS TOUGH THIS TIME OF YEAR TO DECIDE
BETWEEN SVR WARNINGS AND HIGH WIND WARNINGS. FEW CHANGES MADE WITH
THE UPDATE.
PREVIOUS DISCUSSION...RAIN SHOULD SPREAD ACROSS THE AREA TONIGHT
AS THE MAIN SHORT WAVE LIFTS OUT. THE SOUTH SOUTHEAST DOWN SLOPE
WIND LESSEN THE RAIN TO SOME EXTENT ACROSS NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA BUT EVERYONE SHOULD SEE A PERIOD OF
RAIN/SHOWERS.
THE LOW LEVEL JET IS PROGGED TO INCREASE DRAMATICALLY TONIGHT...
INCREASING TO 70-80 KNOTS. DOES NOT GET MUCH STRONGER THAN THAT. THE
WARM AIR ALOFT AND THE RAIN SHOULD DO A GOOD JOB AT KEEPING THE
LOWER LAYERS STABLE. THE MIXED LAYER IS PROGGED TO REMAIN RELATIVELY
SHALLOW TONIGHT...ONLY ABOUT 1K. WE CAN PROBABLY KEEP THE SOUTH
DOWN SLOPE WINDS IN CHECK. THAT BEING SAID...WE CAN STILL TAP
30-35 KNOT WINDS EVEN WITH THE STABLE CONDITIONS. CANNOT RULE OUT
THAT ROGUE 40 KNOT GUST SOMEWHERE BUT IN GENERAL WE SHOULD BE ABLE
TO STAY UNDER THE WIND ADVISORY/WARNING CRITERIA TONIGHT. THE
EXCEPTION WOULD BE ALONG THE EAST LAKESHORE FROM EAST OF MENTOR
THROUGH ERIE COUNTY PA. WILL NEED TO HAVE AN ADVISORY THERE
STARTING ABOUT 10 PM. JUST A LITTLE TOO EASY WITH THE DOWN SLOPE
COMPLIMENT TO GET TO 40 KNOTS OR MORE ESPECIALLY IN ERIE COUNTY PA.
TEMPS MAY DROP A FEW DEGREES WITH THE ONSET OF THE RAIN OTHERWISE
WITH THE STRONG SOUTH FLOW AND RISING DEWPOINTS...TEMPERATURES
WILL BE STEADY OR RISE TONIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
WIND WILL BE THE CONCERN ON MONDAY. WE START THE DAY WITH A 30-40
KNOTS AT 925 MB AND 60 KNOTS OR MORE AT 850 MB. AS STATED
ABOVE...THE RAIN WILL CREATE A RELATIVELY STABLE SITUATION IN THE
BOUNDARY LAYER EARLY ON...BUT THAT WILL ERODE ESPECIALLY WITH THE
ARRIVAL OF THE COLD FRONT. WE TYPICALLY CAN GET 60-70% MIXING IN
THIS TYPE OF SITUATION. THAT WOULD NECESSITATE A WIND ADVISORY...
WITH STRONG ISENTROPIC DESCENT AND LARGE PRESSURE RISES ARRIVING
(+6 TO +8 MB)...A SOUTHWEST WIND DIRECTION IN LINE WITH THE
MOMENTUM AND MOVEMENT OF THE SURFACE LOW....LITTLE LOW LEVEL SHEAR
AND THE POSSIBILITY OF A CONVECTIVE LINE OF SHOWERS WITH THE
FRONTAL PASSAGE...NOT TOO MENTION A FAVORABLE TIME OF DAY FOR
MAXIMUM MIXING...A WIND WARNING MAY BE NECESSARY. I WOULD FEEL
MORE CERTAIN IF THE COLD ADVECTION WAS STRONGER AND QUICKER. WILL
ISSUE A HIGH WIND WATCH AND KEEP THE OPTIONS OPEN FOR EITHER A
WIND ADVISORY OR A HIGH WIND WARNING FOR MONDAY AFTERNOON WITH THE
PASSAGE OF THE COLD FRONT...CONTINUING INTO THE EVENING.
WARM UNTIL THE FRONTAL PASSAGE ON MONDAY. HIGHS GENERALLY 55 TO
60 AHEAD OF THE FRONT.
SEASONABLY COLDER AIR WILL SWEEP IN BEHIND THE FRONT. TEMPERATURES
WILL LIKELY NOT DROP OFF TOO QUICKLY ON MONDAY AFTERNOON GIVEN
THE WELL MIXED NATURE OF THE AIR MASS AND THE CHANCE THAT A FEW
PEAKS OF SUNSHINE MIGHT DEVELOP. LOWS MONDAY NIGHT NEAR NORMAL IN
THE UPPER 20S/LOWER 30S.
THE FLOW WILL BE SOUTHWEST ON TUESDAY. NOT MUCH LAKE INFLUENCE
EXCEPT PERHAPS FROM ASHTABULA TO ERIE WHERE SOME SNOW
SHOWERS/FLURRIES MIGHT CLIP THE LAKESHORE. THE STRATOCUMULUS WILL
INCREASE DIURNALLY DURING THE DAY...PARTLY TO MOSTLY CLOUDY. HIGHS
IN THE 30S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MODELS CONTINUE WITH A COASTAL LOW OFF THE MID ATLANTIC COAST
WEDNESDAY EVENING...THEN DEEPENING AND TRACKING INTO NEWFOUNDLAND
THANKSGIVING DAY. TROUGH WILL REMAIN OVER THE EASTERN LAKES THROUGH
THURSDAY NIGHT. BEST MOISTURE IN THE WEST SO KEPT LIKELY POPS
ACROSS THE EASTERN CWA. COLDER AIR BEHIND THE CLIPPER DROPS THE
850MB TEMPS OVER LAKE ERIE TO -14C BY THURSDAY EVENING SO LAKE
EFFECT SNOW LIKELY...PRIMARILY IN THE SNOWBELT THURSDAY NIGHT. HIGH
PRESSURE MOVES OVER THE AREA FRIDAY CHOCKING OF LINGERING LAKE
EFFECT.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
A WARM FRONT OVER THE OHIO VALLEY WILL MOVE NORTH OVERNIGHT AND AS
THIS HAPPENS THE SHOWERS WILL DECREASE FROM THE SOUTH. A BREAK
WILL OCCUR IN THE WARM SECTOR ON MONDAY ESPECIALLY OVER NE OH AND
NW PA AND THEN A STRONG COLD FRONT WILL MOVE THROUGH. SOME SHOWERS
AND MAY BE EVEN AN ISOLATED THUNDERSTORM MAY OCCUR WITH THE
FRONTAL PASSAGE.
GUSTY SOUTHEAST TO SOUTH WINDS WILL OCCUR AT TIMES TONIGHT AS THE
LOW MOVES FROM THE MIDWEST TO THE UPPER PENINSULA OF MICHIGAN.
ON MONDAY AS THE BAND OF SHOWERS MOVES THROUGH STRONG WINDS WILL
BE ASSOCIATED WITH THE FRONT AND BEHIND IT IN THE COLD ADVECTION.
.OUTLOOK...NON VFR TUESDAY AND THEN AGAIN WEDNESDAY NIGHT INTO
THURSDAY IN SNOW.
&&
.MARINE...
ISSUED LOW WATER ADVISORY BEGINNING MONDAY AFTERNOON AND
CONTINUING INTO TUESDAY AFTERNOON. WATER LEVELS COULD GET AS LOW
AS 4 FEET BELOW LOW WATER DATUM. THE STRONG GALE FORCE SOUTHWEST
FLOW WILL CAUSE THIS.
PREVIOUS DISCUSSION...
ISSUED GALE WARNING FOR LAKE ERIE BEGINNING
MONDAY MORNING. MODELS CONTINUE TO DEEPEN THE OKLAHOMA LOW NORTH
OVER LAKE MICHIGAN TONIGHT LIFTING A WARM FRONT ACROSS THE LAKE.
BY DAYBREAK THE THE 925MB WINDS INCREASE TO 40-45 KNOTS...NOT SURE
HOW MUCH WILL MIX DOWN IN WAA PATTERN. STRONGEST WINDS EXPECTED
IMMEDIATELY AHEAD AND BEHIND THE ARCTIC FRONT. MODELS MOVE THE
FRONT ACROSS LAKE ERIE DURING MONDAY AFTERNOON. EXPECT 40 KNOT
GALES...BUT 45 KNOT GALES NOT OUT OF THE QUESTION. THIS STRONG
SOUTHWEST FLOW WILL CREATE A LOW WATER SITUATION FOR THE WESTERN
BASIN. WINDS ARE EXPECTED TO REMAIN AT GALE FORCE INTO TUESDAY
MORNING...THEN SLOWLY DIMINISH TUESDAY NIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL NOON EST MONDAY FOR OHZ012-089.
HIGH WIND WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR OHZ011>014-020>023-031>033-038-089.
HIGH WIND WATCH FROM 10 AM EST MONDAY THROUGH MONDAY EVENING
FOR OHZ003-006>010-017>019-027>030-036-037-047.
PA...WIND ADVISORY UNTIL NOON EST MONDAY FOR PAZ001-002.
HIGH WIND WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR PAZ001>003.
MARINE...GALE WARNING FROM 9 AM MONDAY TO 4 PM EST TUESDAY FOR LEZ061-
145>149-165>169.
LOW WATER ADVISORY FROM 3 PM MONDAY TO 4 PM EST TUESDAY FOR
LEZ142>144-162>164.
GALE WARNING FROM 9 AM MONDAY TO 10 AM EST TUESDAY FOR
LEZ142>144-162>164.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KEC/KOSARIK
SHORT TERM...KOSARIK
LONG TERM...DJB
AVIATION...KIELTYKA
MARINE...DJB/KIELTYKA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
414 AM EST MON NOV 24 2014
.SYNOPSIS...
NEAR-RECORD WARM TEMPERATURES ARE EXPECTED OVER MUCH OF THE AREA
TODAY...BEFORE COLD AIR ARRIVES TONIGHT BEHIND A DEPARTING LOW
PRESSURE SYSTEM. ANOTHER AREA OF LOW PRESSURE WILL MOVE ALONG THE
MID ATLANTIC COAST WEDNESDAY INTO THURSDAY... BRINGING A CHANCE OF
SIGNIFICANT SNOW TO THE EASTERN HALF OF PENNSYLVANIA. ANOTHER
SHOT OF COLD AIR WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
STEADY OR SLOWLY RISING TEMPERATURES ARE THE NORM THIS MORNING AS
WARM FRONT LIFTS ACROSS CENTRAL PA. STEADIEST AND HEAVIEST RAINFALL
HAS STREAKED NORTH AND EAST OF MY AREA AT THIS TIME ON THE NOSE OF
A 55-65KT 850 MB JET LIFTING INTO NY STATE. LIGHTER SHOWERS STILL
TRAVERSING THE HIGHER TERRAIN OF WESTERN PA AS WELL AS THE LOWER
SUSQ RIVER VALLEY...BUT THESE WILL DECREASE LATER THIS MORNING
AS THE WARM FRONT CONTINUES TO LIFT NORTH UPSTATE NY.
SHORT TERM CONCERN IS FOR STRONG GUSTY WINDS ACROSS THE HIGHER
ELEVS OF THE ALLEGHENIES LATER TODAY. STRONGLY COUPLED SOUTHWEST
WINDS SHOULD EASILY CREATE IN THE UPPER 30KT RANGE...LIKELY
INCREASING TO OCNLY 40-43 KTS IN THE LATE AFTERNOON AND NIGHT.
WIND ADVISORY REMAINS IN EFFECT 17Z-09Z TUESDAY FOR THE NW MTNS
AND LAUREL HIGHLANDS.
CLEARING AND STRONG MIXING WILL PUSH AFTERNOON TEMPS TO NEAR-
RECORD LEVELS. THE BIGGEST TEMP BUST POTENTIAL AREA /STAY TOO
COOL VS FCST/ WILL BE THE NORTHEASTERN MTNS. COLD FRONT TIMED TO
CROSS THE REGION LATE THIS AFTERNOON AND EVENING...BUT COOLING
WILL NOT BE SHARP AS DEEP NEARLY PARALLEL FLOW PROMOTES ONLY SLOW
SOUTHEAST PROGRESSION OF POST FRONTAL AIR MASS. AFTER A ROUND OF
EVENING SHOWERS...EXPECT THE REMAINDER OF TONIGHT TO BE DRY AS
COLD ADVECTION PERSISTS ON WSW FLOW. MINS WILL NOT BE VERY COLD...
ONLY RANGING FROM AROUND 30F NORTH TO THE LOWER 40S SOUTHEAST.
&&
.SHORT TERM /TUESDAY/...
BOUNDARY LAYER FLOW WILL SLOWLY BACK AND WEAKEN ON TUESDAY...WHILE A
WEAK AREA OF HIGH PRESSURE DRIFTS INTO THE OHIO VALLEY AND INTO
THE WRN PA TUESDAY NIGHT. TUESDAY WILL BE THE CALM BEFORE THE
STORM AS ALL EYES SHIFT SOUTHWARD FOR THE EVOLUTION OF WHAT COULD
BE THE FIRST WIDESPREAD SIGNIFICANT SNOWFALL ACROSS MUCH OF THE
EASTERN HALF OF CENTRAL PA WEDNESDAY.
COLD AIR WILL CONTINUE TO FILTER IN ALOFT...AND HIGHS TUESDAY WILL
BE SOME 20 DEGREES COOLER THAN THE NEAR RECORD READINGS OF MONDAY
AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
POTENTIAL FOR SIG WINTER IMPACTS FROM LOW PRESSURE MOVING UP THE
EAST COAST ON WED/WED NIGHT. WILL CONTINUE TO INJECT
INTERPRETATION OF THE LATEST MODEL GUIDANCE WITH EACH 3-HOURLY
UPDATE TO GUIDE DECISION SUPPORT LEADING UP TO THE PRIME TRAVEL
PERIOD FOR THE THANKSGIVING HOLIDAY.
HIGHLY AMPLIFIED AND ACTIVE UPPER AIR PATTERN WILL BRING A PERIOD
OF ACTIVE WEATHER THROUGH THE COMING WEEK. THE 500MB CONFIGURATION
WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE
WESTERN ATLANTIC WITH A FULL-LATITUDE PERSISTENT TROUGH EBBING
AND FLOWING OVER THE CENTRAL AND EASTERN U.S.
AFTER THE EXIT OF MONDAY/S LOW PRESSURE AREA...COLDER TEMPS
RETURN ON BRISK W/SW FLOW FOR TUE DROPPING HIGHS SOME 20-25F FROM
PREV DAYS READINGS. WE/LL ALSO SEE THE RETURN OF LIGHT SNOW
SHOWERS IN THE WESTERN HIGHER TERRAIN.
THEN FOCUS WILL TURN TO A WAVE CURRENTLY DROPPING SE FROM BRITISH
COLUMBIA AND WASHINGTON STATE...WHICH WILL SPAWN AN AREA OF LOW
PRESSURE OVER THE SE US TUESDAY NIGHT...THAT WILL LIKELY MOVE
NORTH NORTHEASTWARD JUST OFF THE EAST COAST WEDNESDAY INTO
THURSDAY.
12Z/18Z OPERATIONAL AND GEFS RUNS ALONG WITH THE 21Z SREF ARE
BECOMING FAIRLY WELL CLUSTERED WITH RESPECT TO THE LOCATION OF THE
NEAR...TO SUB-1000 MB SFC LOW EARLY WED EVENING /NEAR...AND UP TO
ABOUT 200 NM EAST OF DELMARVA PENINSULA/.
THERE IS STILL MUCH UNCERTAINTY AT THIS 60-72 HOUR TIMEFRAME
BEFORE THE EVENT...WITH RESPECT TO THE EXACT TRACK OF THE SFC LOW
AND ASSOCIATED SNOW/RAIN AMOUNTS.
COLD AIR WILL BE IN PLACE WED MORNING AS A /WEAK/ HIGH PRESSURE
RIDGE RETREATS TO THE NORTH AHEAD OF THE APPROACHING LOW.
NORTHERLY FLOW OVER CENTRAL PA NOT PARTICULARLY STRONG IN ANY
MODEL...BUT A SHORTWAVE LOOKS POISED TO SLIDE IN FROM THE GREAT
LAKES ON WED TO ADD SOME SYNOPTIC LIFT TO A RAPIDLY DEEPENING AND
FAST MOVING SURFACE LOW.
THE 12Z ECMWF AND IT`S ENSEMBLE ARE VERY SIMILAR HUGGING THE SFC
LOW ALONG THE SHORELINE...WHILE US/CANADIAN MODELS AND THEIR
ENSEMBLES ARE FURTHER EAST BY 100-200 NM. EXPERIENCE SHOWS THAT
THE LACK OF A SIGNIFICANT BLOCKING HIGH TO OUR NORTH OR
NORTHEAST...FAVORS A MORE WESTERN TRACK /SIMILAR TO THE EC AND ITS
ENSEMBLE/. SHOULD THE WWD TREND CONTINUE EVEN FURTHER WITH AN
EARLIER INJECTION OF NRN STREAM ENERGY INTO THE SOUTHERN STREAM
SYSTEM...IT/S CONCEIVABLE THAT OUR FAR SE ZONES /NEAR KLNS AND
KMDT/ COULD EVEN SEE A MIX WITH SLEET AND RAIN FOR A PERIOD THAT
WOULD HOLD DOWN ACCUMULATIONS.
PRECIP MAY START OFF EARLY WED AS A MIX OF RAIN AND SNOW IN THE
SE...BUT COOLING TEMPS ALOFT SHOULD CONVERT ALL PRECIP OVER TO
SNOW BY MIDDAY. AS IS A GENERAL RULE WITH THESE TYPES OF EVENTS...
THERE WILL LIKELY BE A SHARP DROP OFF IN ACCUMULATIONS ON THE NW
EDGE OF THE HEAVIER SNOWS. BIGGEST POTENTIAL IMPACTS IN OUR CWA
WILL BE THE CENTRAL MTNS AND SUSQ VALLEY...WHERE POTENTIAL FOR A
SEVERAL HOUR PERIOD OF HEAVY ACCUMULATING SNOW WILL EXIST. BUT
AGAIN...SMALL CHANGES IN THE ULTIMATE TRACK COULD LEAD TO
MODIFICATIONS OF SNOWFALL FORECASTS. THE TAKE AWAY...THOUGH THE
DETAILS REMAIN UNCERTAIN...THERE WILL BE SIG IMPACTS TO TRAVEL
ALONG THE U.S. EAST COAST ON ONE OF THE BUSIEST DAYS OF THE YEAR
/WED/. PLAN ACCORDINGLY.
COLDER AIR REMAINS IN PLACE LATE IN THE WEEK AS SCT SNOW SHOWERS
RETURN TO THE WESTERN HIGHER TERRAIN. TEMPS LOOK TO GRADUALLY
MODIFY LATE WEEKEND HEADING INTO NEXT WEEK...WITH NO BIG STORM
SYSTEMS EXPECTED AFTER THANKSGIVING.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A LOW PRESSURE SYSTEM TRACKING NORTHWARD INTO THE GRT LKS WILL
SPREAD LOWERING CIGS AND RAIN ACROSS CENTRAL PA TONIGHT. REGIONAL
RADAR AT 06Z SHOWS A DRY SLOT BEGINNING TO ENTER SOUTHWEST PA.
THIS WILL CAUSE CIGS AND VSBYS TO INCREASE...AND SHOULD LIFT
RESTRICTIONS SLOWLY. THE LOW LEVEL MOISTURE REMAINS HIGH AND
SOUTHERLY WINDS IN THE 1-2 KFT LAYER WILL BECOME VERY STRONG
OVERNIGHT...MAKING LLWS A NEAR CERTAINTY. SFC GUSTS OVERNIGHT WILL
BE HIGHEST AT KJST DUE TO IT/S RIDGETOP LOCATION. HRRR OUTPUT
SUGGESTS GUSTS BTWN 25-35KTS ARE POSSIBLE THERE UNTIL 09Z. MUCH
LIGHTER SFC WINDS EXPECTED ELSEWHERE...WHICH WILL LEAD TO THE
LLWS.
THE CONDITIONS LOOK TO IMPROVE QUICKER THAN PREVIOUSLY
MODELED...WHICH MEANS THE LOW CIGS AND LINGERING DRIZZLE WILL
GIVE WAY TO IMPROVING CONDS BY MID MONDAY AM...AS WARM FRONT
LIFTS NORTH OF THE REGION. GENERALLY VFR CONDS ARE ANTICIPATED
MONDAY AFTERNOON.
A COLD FRONT MOVING FROM THE WEST WILL BE ACCOMPANIED BY SCT LATE
DAY SHRA ACROSS THE W MTNS...POSSIBLY PRODUCING A BRIEF VSBY
REDUCTION AT KBFD OR KJST.
OUTLOOK...
TUE...NO SIG WX EXPECTED.
WED...SNOW/LOW VSBYS POSS EASTERN PA.
THU...-SHSN/REDUCED VSBYS POSS NW MTNS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 4 AM EST TUESDAY FOR
PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...DEVOIR/RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
110 AM EST MON NOV 24 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL PUSH NORTHWARD THROUGH THE GREAT LAKES
LATE TONIGHT AND MONDAY. IT WILL BRING A SLUG OF RAIN THROUGH THE
STATE TONIGHT. VERY WARM AND EVEN NEAR-RECORD WARM TEMPERATURES
ARE EXPECTED OVER MUCH OF THE AREA MONDAY...BEFORE THE COLD AIR
FOLLOWING THE GREAT LAKES LOW MOVES ACROSS LATE MONDAY AND MONDAY
NIGHT. A DEEPENING AREA OF LOW PRESSURE WILL MOVE NORTHWARD ALONG
THE MID ATLANTIC COAST WEDNESDAY. THERE IS A LOW CONFIDENCE AS TO
WHAT THE EXACT PATH OF THIS STORM WILL BE. HOWEVER...THE EASTERN
THIRD TO HALF OF THE STATE COULD HAVE A SIGNIFICANT SNOWFALL. COLD
AIR WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WARM FRONT LIFTING THROUGH THE VIRGINIAS EARLY THIS MORNING WITH
STRONG SOUTHERLY FLOW ALOFT. VIGOROUS UPPER TROF LIFTING THROUGH
CENTRAL AND EASTERN OHIO WITH WIDESPREAD LIGHT TO MODERATE RAIN
SHIELD EXTENDING FROM NORTHEAST OHIO THROUGH ALL BUT FAR SOUTHWEST
PA. BACK EDGE OF RAIN SHIELD MAKING STEADY PROGRESS NNE
AS PREVIOUSLY MENTIONED...FAST NORTHWARD PROPAGATION OF RAIN
PRECLUDES ANY CONCERNS FOR HEAVY RAIN. GENERAL 0.50 INCHES QPF IS
EXPECTED...BUT SOME HEAVIER AMOUNTS ARE POSSIBLE FAR SOUTHEAST
WHERE CONVECTIVE INSTABILITY IS PREVENT. KEPT MENTION OF T THERE
FOR THE OVERNIGHT.
WINDS ALOFT GET UP TO 50 KTS OVER THE CENTRAL MTNS...BUT THE
GENERAL STABILITY OVER THE BULK OF THE AREA SHOULD KEEP GUSTS DOWN
DURING THE NIGHT. THE EXCEPTION COULD BE THE HIGHER PEAKS IN THE
WEST WHICH COULD BE GUSTY /INTO THE 20 PLUS KT RANGE/ THROUGH THE
NIGHT. TEMPS WILL LIKELY LEVEL-OFF OR EVEN RISE LATER TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
SUBSIDENCE/DRYING IMMEDIATELY BEHIND THE OVERNIGHT WAVE WILL START
THE BREAK-UP OF THE CLOUDS FROM S-N. HOWEVER...THE AMBIENT
MOISTURE WILL BE HIGH IN THE LLVLS AND FLOW OUT OF THE SOUTH
THROUGH THE COLUMN WILL MAKE IT DIFFICULT TO CLEAR THE NORTHERN
HALF OF THE AREA TOO RAPIDLY. THE SOUTH WILL LIKELY GET SOME
DECENT CLEARING AND THE WARM AIR AHEAD OF THE COLD FRONT WILL PUSH
TEMPS TO NEAR-RECORD LEVELS ON MONDAY AFTERNOON. WILL KEEP THE
NUMBERS SLIGHTLY LOWER THAN RECORDS...THOUGH. THIS IS DUE TO THE
UNCERTAINTY OF HOW MUCH SUN TIME WE WILL HAVE. THE BIGGEST TEMP
BUST POTENTIAL AREA /STAY TOO COOL VS FCST/ WILL BE THE
NORTHEASTERN MTNS. THEY COULD STAY TOO CLOUDY. THE INSTABILITY
COULD ALSO TOUCH OFF A FEW SHOWERS -MAINLY IN THE CENTRAL AND
NORTH. THE COLD FRONT SHOULD MOVE THROUGH LATER IN THE DAY AND
EARLY EVENING.
THE WINDS WILL BE THE OTHER STORY - ALONG WITH THE TEMPS. THE
WESTERN MOUNTAINS/ALLEGHENIES WILL BE THE GUSTIEST PLACE. MIXED-
WINDS WITH LITTLE DIRECTIONAL SHEAR OFF BUFKIT SOUNDINGS MAKE FOR
WIND GUSTS EASILY INTO THE UPPER 30KT RANGE...LIKELY INCREASING TO
OCNLY 40-43 KTS IN THE LATE AFTERNOON AND NIGHT. A WIND ADVISORY
WAS RECENTLY ISSUED FOR 17Z MONDAY - 09Z TUESDAY FOR THE NW MTNS
AND LAUREL HIGHLANDS.
THE PERIOD OF LIKELY HIGHEST GUSTS APPEAR TO BE NEAR...AND FOR SEVERAL
HOURS IN THE WAKE OF THE CFROPA /OR FROM 21Z MONDAY TO 05Z
TUESDAY/.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
POTENTIAL FOR SIG WINTER IMPACTS FROM LOW PRESSURE MOVING UP THE
EAST COAST ON WED/WED NIGHT. WILL CONTINUE TO INJECT
INTERPRETATION OF THE LATEST MODEL GUIDANCE WITH EACH 3-HOURLY
UPDATE TO GUIDE DECISION SUPPORT LEADING UP TO THE PRIME TRAVEL
PERIOD FOR THE THANKSGIVING HOLIDAY.
HIGHLY AMPLIFIED AND ACTIVE UPPER AIR PATTERN WILL BRING A PERIOD
OF ACTIVE WEATHER THROUGH THE COMING WEEK. THE 500MB CONFIGURATION
WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE
WESTERN ATLANTIC WITH A FULL-LATITUDE PERSISTENT TROUGH EBBING
AND FLOWING OVER THE CENTRAL AND EASTERN U.S.
AFTER THE EXIT OF MONDAY/S LOW PRESSURE AREA...COLDER TEMPS
RETURN ON BRISK W/SW FLOW FOR TUE DROPPING HIGHS SOME 20-25F FROM
PREV DAYS READINGS. WE/LL ALSO SEE THE RETURN OF LIGHT SNOW
SHOWERS IN THE WESTERN HIGHER TERRAIN.
THEN FOCUS WILL TURN TO A WAVE CURRENTLY DROPPING SE FROM BRITISH
COLUMBIA AND WASHINGTON STATE...WHICH WILL SPAWN AN AREA OF LOW
PRESSURE OVER THE SE US TUESDAY NIGHT...THAT WILL LIKELY MOVE
NORTH NORTHEASTWARD JUST OFF THE EAST COAST WEDNESDAY INTO
THURSDAY.
12Z/18Z OPERATIONAL AND GEFS RUNS ALONG WITH THE 21Z SREF ARE
BECOMING FAIRLY WELL CLUSTERED WITH RESPECT TO THE LOCATION OF THE
NEAR...TO SUB-1000 MB SFC LOW EARLY WED EVENING /NEAR...AND UP TO
ABOUT 200 NM EAST OF DELMARVA PENINSULA/.
THERE IS STILL MUCH UNCERTAINTY AT THIS 60-72 HOUR TIMEFRAME
BEFORE THE EVENT...WITH RESPECT TO THE EXACT TRACK OF THE SFC LOW
AND ASSOCIATED SNOW/RAIN AMOUNTS.
COLD AIR WILL BE IN PLACE WED MORNING AS A /WEAK/ HIGH PRESSURE
RIDGE RETREATS TO THE NORTH AHEAD OF THE APPROACHING LOW.
NORTHERLY FLOW OVER CENTRAL PA NOT PARTICULARLY STRONG IN ANY
MODEL...BUT A SHORTWAVE LOOKS POISED TO SLIDE IN FROM THE GREAT
LAKES ON WED TO ADD SOME SYNOPTIC LIFT TO A RAPIDLY DEEPENING AND
FAST MOVING SURFACE LOW.
THE 12Z ECMWF AND IT`S ENSEMBLE ARE VERY SIMILAR HUGGING THE SFC
LOW ALONG THE SHORELINE...WHILE US/CANADIAN MODELS AND THEIR
ENSEMBLES ARE FURTHER EAST BY 100-200 NM. EXPERIENCE SHOWS THAT
THE LACK OF A SIGNIFICANT BLOCKING HIGH TO OUR NORTH OR
NORTHEAST...FAVORS A MORE WESTERN TRACK /SIMILAR TO THE EC AND ITS
ENSEMBLE/. SHOULD THE WWD TREND CONTINUE EVEN FURTHER WITH AN
EARLIER INJECTION OF NRN STREAM ENERGY INTO THE SOUTHERN STREAM
SYSTEM...IT/S CONCEIVABLE THAT OUR FAR SE ZONES /NEAR KLNS AND
KMDT/ COULD EVEN SEE A MIX WITH SLEET AND RAIN FOR A PERIOD THAT
WOULD HOLD DOWN ACCUMULATIONS.
PRECIP MAY START OFF EARLY WED AS A MIX OF RAIN AND SNOW IN THE
SE...BUT COOLING TEMPS ALOFT SHOULD CONVERT ALL PRECIP OVER TO
SNOW BY MIDDAY. AS IS A GENERAL RULE WITH THESE TYPES OF EVENTS...
THERE WILL LIKELY BE A SHARP DROP OFF IN ACCUMULATIONS ON THE NW
EDGE OF THE HEAVIER SNOWS. BIGGEST POTENTIAL IMPACTS IN OUR CWA
WILL BE THE CENTRAL MTNS AND SUSQ VALLEY...WHERE POTENTIAL FOR A
SEVERAL HOUR PERIOD OF HEAVY ACCUMULATING SNOW WILL EXIST. BUT
AGAIN...SMALL CHANGES IN THE ULTIMATE TRACK COULD LEAD TO
MODIFICATIONS OF SNOWFALL FORECASTS. THE TAKE AWAY...THOUGH THE
DETAILS REMAIN UNCERTAIN...THERE WILL BE SIG IMPACTS TO TRAVEL
ALONG THE U.S. EAST COAST ON ONE OF THE BUSIEST DAYS OF THE YEAR
/WED/. PLAN ACCORDINGLY.
COLDER AIR REMAINS IN PLACE LATE IN THE WEEK AS SCT SNOW SHOWERS
RETURN TO THE WESTERN HIGHER TERRAIN. TEMPS LOOK TO GRADUALLY
MODIFY LATE WEEKEND HEADING INTO NEXT WEEK...WITH NO BIG STORM
SYSTEMS EXPECTED AFTER THANKSGIVING.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A LOW PRESSURE SYSTEM TRACKING NORTHWARD INTO THE GRT LKS WILL
SPREAD LOWERING CIGS AND RAIN ACROSS CENTRAL PA TONIGHT. REGIONAL
RADAR AT 06Z SHOWS A DRY SLOT BEGINNING TO ENTER SOUTHWEST PA.
THIS WILL CAUSE CIGS AND VSBYS TO INCREASE...AND SHOULD LIFT
RESTRICTIONS SLOWLY. THE LOW LEVEL MOISTURE REMAINS HIGH AND
SOUTHERLY WINDS IN THE 1-2 KFT LAYER WILL BECOME VERY STRONG
OVERNIGHT...MAKING LLWS A NEAR CERTAINTY. SFC GUSTS OVERNIGHT WILL
BE HIGHEST AT KJST DUE TO IT/S RIDGETOP LOCATION. HRRR OUTPUT
SUGGESTS GUSTS BTWN 25-35KTS ARE POSSIBLE THERE UNTIL 09Z. MUCH
LIGHTER SFC WINDS EXPECTED ELSEWHERE...WHICH WILL LEAD TO THE
LLWS.
THE CONDITIONS LOOK TO IMPROVE QUICKER THAN PREVIOUSLY
MODELED...WHICH MEANS THE LOW CIGS AND LINGERING DRIZZLE WILL
GIVE WAY TO IMPROVING CONDS BY MID MONDAY AM...AS WARM FRONT
LIFTS NORTH OF THE REGION. GENERALLY VFR CONDS ARE ANTICIPATED
MONDAY AFTERNOON.
A COLD FRONT MOVING FROM THE WEST WILL BE ACCOMPANIED BY SCT LATE
DAY SHRA ACROSS THE W MTNS...POSSIBLY PRODUCING A BRIEF VSBY
REDUCTION AT KBFD OR KJST.
OUTLOOK...
TUE...NO SIG WX EXPECTED.
WED...SNOW/LOW VSBYS POSS EASTERN PA.
THU...-SHSN/REDUCED VSBYS POSS NW MTNS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 4 AM EST TUESDAY FOR
PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/DEVOIR/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1244 AM EST MON NOV 24 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL PUSH NORTHWARD THROUGH THE GREAT LAKES
LATE TONIGHT AND MONDAY. IT WILL BRING A SLUG OF RAIN THROUGH THE
STATE TONIGHT. VERY WARM AND EVEN NEAR-RECORD WARM TEMPERATURES
ARE EXPECTED OVER MUCH OF THE AREA MONDAY...BEFORE THE COLD AIR
FOLLOWING THE GREAT LAKES LOW MOVES ACROSS LATE MONDAY AND MONDAY
NIGHT. A DEEPENING AREA OF LOW PRESSURE WILL MOVE NORTHWARD ALONG
THE MID ATLANTIC COAST WEDNESDAY. THERE IS A LOW CONFIDENCE AS TO
WHAT THE EXACT PATH OF THIS STORM WILL BE. HOWEVER...THE EASTERN
THIRD TO HALF OF THE STATE COULD HAVE A SIGNIFICANT SNOWFALL. COLD
AIR WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WARM FRONT LIFTING THROUGH THE VIRGINIAS EARLY THIS MORNING WITH
STRONG SOUTHERLY FLOW ALOFT. VIGOROUS UPPER TROF LIFTING THROUGH
CENTRAL AND EASTERN OHIO WITH WIDESPREAD LIGHT TO MODERATE RAIN
SHIELD EXTENDING FROM NORTHEAST OHIO THROUGH ALL BUT FAR SOUTHWEST
PA. BACK EDGE OF RAIN SHIELD MAKING STEADY PROGRESS NNE
AS PREVIOUSLY MENTIONED...FAST NORTHWARD PROPOGATION OF RAIN
PRECLUDES ANY CONCERNS FOR HEAVY RAIN. GENERAL 0.50 INCHES QPF IS
EXPECTED...BUT SOME HEAVIER AMOUNTS ARE POSSIBLE FAR SOUTHEAST
WHERE CONVECTIVE INSTABILITY IS PREVENT. KEPT MENTION OF T THERE
FOR THE OVERNIGHT.
WINDS ALOFT GET UP TO 50 KTS OVER THE CENTRAL MTNS...BUT THE
GENERAL STABILITY OVER THE BULK OF THE AREA SHOULD KEEP GUSTS DOWN
DURING THE NIGHT. THE EXCEPTION COULD BE THE HIGHER PEAKS IN THE
WEST WHICH COULD BE GUSTY /INTO THE 20 PLUS KT RANGE/ THROUGH THE
NIGHT. TEMPS WILL LIKELY LEVEL-OFF OR EVEN RISE LATER TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
SUBSIDENCE/DRYING IMMEDIATELY BEHIND THE OVERNIGHT WAVE WILL START
THE BREAK-UP OF THE CLOUDS FROM S-N. HOWEVER...THE AMBIENT
MOISTURE WILL BE HIGH IN THE LLVLS AND FLOW OUT OF THE SOUTH
THROUGH THE COLUMN WILL MAKE IT DIFFICULT TO CLEAR THE NORTHERN
HALF OF THE AREA TOO RAPIDLY. THE SOUTH WILL LIKELY GET SOME
DECENT CLEARING AND THE WARM AIR AHEAD OF THE COLD FRONT WILL PUSH
TEMPS TO NEAR-RECORD LEVELS ON MONDAY AFTERNOON. WILL KEEP THE
NUMBERS SLIGHTLY LOWER THAN RECORDS...THOUGH. THIS IS DUE TO THE
UNCERTAINTY OF HOW MUCH SUN TIME WE WILL HAVE. THE BIGGEST TEMP
BUST POTENTIAL AREA /STAY TOO COOL VS FCST/ WILL BE THE
NORTHEASTERN MTNS. THEY COULD STAY TOO CLOUDY. THE INSTABILITY
COULD ALSO TOUCH OFF A FEW SHOWERS -MAINLY IN THE CENTRAL AND
NORTH. THE COLD FRONT SHOULD MOVE THROUGH LATER IN THE DAY AND
EARLY EVENING.
THE WINDS WILL BE THE OTHER STORY - ALONG WITH THE TEMPS. THE
WESTERN MOUNTAINS/ALLEGHENIES WILL BE THE GUSTIEST PLACE. MIXED-
WINDS WITH LITTLE DIRECTIONAL SHEAR OFF BUFKIT SOUNDINGS MAKE FOR
WIND GUSTS EASILY INTO THE UPPER 30KT RANGE...LIKELY INCREASING TO
OCNLY 40-43 KTS IN THE LATE AFTERNOON AND NIGHT. A WIND ADVISORY
WAS RECENTLY ISSUED FOR 17Z MONDAY - 09Z TUESDAY FOR THE NW MTNS
AND LAUREL HIGHLANDS.
THE PERIOD OF LIKELY HIGHEST GUSTS APPEAR TO BE NEAR...AND FOR SEVERAL
HOURS IN THE WAKE OF THE CFROPA /OR FROM 21Z MONDAY TO 05Z
TUESDAY/.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
POTENTIAL FOR SIG WINTER IMPACTS FROM LOW PRESSURE MOVING UP THE
EAST COAST ON WED/WED NIGHT. WILL CONTINUE TO INJECT
INTERPRETATION OF THE LATEST MODEL GUIDANCE WITH EACH 3-HOURLY
UPDATE TO GUIDE DECISION SUPPORT LEADING UP TO THE PRIME TRAVEL
PERIOD FOR THE THANKSGIVING HOLIDAY.
HIGHLY AMPLIFIED AND ACTIVE UPPER AIR PATTERN WILL BRING A PERIOD
OF ACTIVE WEATHER THROUGH THE COMING WEEK. THE 500MB CONFIGURATION
WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE
WESTERN ATLANTIC WITH A FULL-LATITUDE PERSISTENT TROUGH EBBING
AND FLOWING OVER THE CENTRAL AND EASTERN U.S.
AFTER THE EXIT OF MONDAY/S LOW PRESSURE AREA...COLDER TEMPS
RETURN ON BRISK W/SW FLOW FOR TUE DROPPING HIGHS SOME 20-25F FROM
PREV DAYS READINGS. WE/LL ALSO SEE THE RETURN OF LIGHT SNOW
SHOWERS IN THE WESTERN HIGHER TERRAIN.
THEN FOCUS WILL TURN TO A WAVE CURRENTLY DROPPING SE FROM BRITISH
COLUMBIA AND WASHINGTON STATE...WHICH WILL SPAWN AN AREA OF LOW
PRESSURE OVER THE SE US TUESDAY NIGHT...THAT WILL LIKELY MOVE
NORTH NORTHEASTWARD JUST OFF THE EAST COAST WEDNESDAY INTO
THURSDAY.
12Z/18Z OPERATIONAL AND GEFS RUNS ALONG WITH THE 21Z SREF ARE
BECOMING FAIRLY WELL CLUSTERED WITH RESPECT TO THE LOCATION OF THE
NEAR...TO SUB-1000 MB SFC LOW EARLY WED EVENING /NEAR...AND UP TO
ABOUT 200 NM EAST OF DELMARVA PENINSULA/.
THERE IS STILL MUCH UNCERTAINTY AT THIS 60-72 HOUR TIMEFRAME
BEFORE THE EVENT...WITH RESPECT TO THE EXACT TRACK OF THE SFC LOW
AND ASSOCIATED SNOW/RAIN AMOUNTS.
COLD AIR WILL BE IN PLACE WED MORNING AS A /WEAK/ HIGH PRESSURE
RIDGE RETREATS TO THE NORTH AHEAD OF THE APPROACHING LOW.
NORTHERLY FLOW OVER CENTRAL PA NOT PARTICULARLY STRONG IN ANY
MODEL...BUT A SHORTWAVE LOOKS POISED TO SLIDE IN FROM THE GREAT
LAKES ON WED TO ADD SOME SYNOPTIC LIFT TO A RAPIDLY DEEPENING AND
FAST MOVING SURFACE LOW.
THE 12Z ECMWF AND IT`S ENSEMBLE ARE VERY SIMILAR HUGGING THE SFC
LOW ALONG THE SHORELINE...WHILE US/CANADIAN MODELS AND THEIR
ENSEMBLES ARE FURTHER EAST BY 100-200 NM. EXPERIENCE SHOWS THAT
THE LACK OF A SIGNIFICANT BLOCKING HIGH TO OUR NORTH OR
NORTHEAST...FAVORS A MORE WESTERN TRACK /SIMILAR TO THE EC AND ITS
ENSEMBLE/. SHOULD THE WWD TREND CONTINUE EVEN FURTHER WITH AN
EARLIER INJECTION OF NRN STREAM ENERGY INTO THE SOUTHERN STREAM
SYSTEM...IT/S CONCEIVABLE THAT OUR FAR SE ZONES /NEAR KLNS AND
KMDT/ COULD EVEN SEE A MIX WITH SLEET AND RAIN FOR A PERIOD THAT
WOULD HOLD DOWN ACCUMULATIONS.
PRECIP MAY START OFF EARLY WED AS A MIX OF RAIN AND SNOW IN THE
SE...BUT COOLING TEMPS ALOFT SHOULD CONVERT ALL PRECIP OVER TO
SNOW BY MIDDAY. AS IS A GENERAL RULE WITH THESE TYPES OF EVENTS...
THERE WILL LIKELY BE A SHARP DROPOFF IN ACCUMULATIONS ON THE NW
EDGE OF THE HEAVIER SNOWS. BIGGEST POTENTIAL IMPACTS IN OUR CWA
WILL BE THE CENTRAL MTNS AND SUSQ VALLEY...WHERE POTENTIAL FOR A
SEVERAL HOUR PERIOD OF HEAVY ACCUMULATING SNOW WILL EXIST. BUT
AGAIN...SMALL CHANGES IN THE ULTIMATE TRACK COULD LEAD TO
MODIFICATIONS OF SNOWFALL FORECASTS. THE TAKE AWAY...THOUGH THE
DETAILS REMAIN UNCERTAIN...THERE WILL BE SIG IMPACTS TO TRAVEL
ALONG THE U.S. EAST COAST ON ONE OF THE BUSIEST DAYS OF THE YEAR
/WED/. PLAN ACCORDINGLY.
COLDER AIR REMAINS IN PLACE LATE IN THE WEEK AS SCT SNOW SHOWERS
RETURN TO THE WESTERN HIGHER TERRAIN. TEMPS LOOK TO GRADUALLY
MODIFY LATE WEEKEND HEADING INTO NEXT WEEK...WITH NO BIG STORM
SYSTEMS EXPECTED AFTER THANKSGIVING.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A LOW PRES SYSTEM TRACKING NORTHWARD INTO THE GRT LKS WILL SPREAD
LOWERING CIGS AND RAIN ACROSS CENTRAL PA TONIGHT. REGIONAL RADAR
AT 00Z SHOWS THE RAIN ABOUT TO ENTER SOUTHERN PA AND LINEAR
EXTRAPOLATION SUGGESTS THE RAIN WILL OVERSPREAD ALL CENTRAL PA
AIRFIELDS BTWN 02Z-04Z. A BLEND OF LATEST LAMP GUIDANCE...SREF AND
HRRR MDL OUTPUT IMPLY CIGS WILL DROP TO IFR BTWN 04Z-06Z...JUST A
COUPLE HOURS AFTER THE RAIN BEGINS.
SOUTHERLY WINDS IN THE 1-2 KFT LAYER WILL BECOME VERY STRONG
OVERNIGHT...MAKING LLWS A NEAR CERTAINTY. SFC GUSTS OVERNIGHT WILL
BE HIGHEST AT KJST DUE TO IT/S RIDGETOP LOCATION. HRRR OUTPUT
SUGGESTS GUSTS BTWN 25-35KTS ARE POSS THERE BTWN 03Z-07Z. MUCH
LIGHTER SFC WINDS EXPECTED ELSEWHERE...WHICH WILL LEAD TO THE
LLWS.
EARLY LOW CIGS AND LINGERING DRIZZLE WILL GIVE WAY TO IMPROVING
CONDS BY LATE MONDAY AM...AS WARM FRONT LIFTS NORTH OF THE
REGION. GENERALLY VFR CONDS ARE ANTICIPATED MON AFTN. HOWEVER...A
COLD FRONT MOVING FROM THE WEST WILL BE ACCOMPANIED BY SCT LATE
DAY SHRA ACROSS THE W MTNS...POSSIBLY PRODUCING A BRIEF VSBY
REDUCTION AT KBFD OR KJST.
OUTLOOK...
TUE...NO SIG WX EXPECTED.
WED...SNOW/LOW VSBYS POSS EASTERN PA.
THU...-SHSN/REDUCED VSBYS POSS NW MTNS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 4 AM EST TUESDAY FOR
PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/DEVOIR/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1128 PM CST SUN NOV 23 2014
.AVIATION 06Z DISCUSSION...
STORM SYSTEM TO CONTINUE PULLING EAST OVERNIGHT. WE WILL STILL SEE
A FEW RESIDUAL SHOWERS THROUGH THE EARLY MORNING HOURS.
OTW...PRECIP TO CONTINUE TO DIMINISH. PRESSURE GRADIENT WILL
TIGHTEN OVERNIGHT AND WINDS WILL REMAIN BREEZY AND GUSTY AT TIMES.
COLD FRONT TO PUSH THROUGH BETWEEN 12Z AND 15Z WITH WINDS SHIFTING
FROM SOUTHERLY TO SOUTHWESTERLY.
AS FOR CIGS...LOW LEVEL CLOUDINESS WILL PERSIST BUT CIGS WILL
LIFT SOME TOWARD THE END OF THE TAF PD.
&&
.PREV DISCUSSION... /ISSUED 734 PM CST SUN NOV 23 2014/
DISCUSSION...
STRONG VORT AXIS MOVING THROUGH THE MID STATE AT THIS TIME WITH
WIDESPREAD SHOWER ACTIVITY. NOT MUCH IN THE WAY OF PRECIP COVERAGE
BACK TO OUR SOUTHWEST. HRRR SHOWS THAT PRECIP COVERAGE WILL
DECREASE MARKEDLY FROM SW TO NE OVER THE NEXT FEW HOURS.
HOWEVER...ADDITIONAL LIGHT SHOWER ACTIVITY WILL RETURN AFTER
OR JUST BEFORE MIDNIGHT. THEREFORE...CURRENT FCST LOOKS TO BE IN
GOOD SHAPE AS THE POPS WILL DROP DOWN INTO THE CHANCE CATEGORY AFT
MIDNIGHT.
AS FOR THE WIND ADVISORY...GRADIENT STILL LOOKS AS THOUGH IT WILL
BECOME TIGHTER TOWARD 12Z WHEN THE FRONT ROLLS THROUGH. CURRENT
SFC ANALYSIS SHOWS THAT PEAK WINDS ARE GENERALLY IN THE 25 TO 35
MPH RANGE.
SO BASICALLY...NO CHANGES AT THIS TIME TO THE FCST. WILL LIKELY
SEND OUT ANOTHER SET OF ZONES AND LOWER POPS TOWARD THE SOUTHWEST
ONCE THIS CURRENT BATCH OF SHOWERS LIFTS TO THE NORTHEAST.
WINDS MAY ACTUALLY BECOME A LITTLE STRONGER ONCE THE PRECIP FREE
AREA MOVES IN. TEMPS STILL LOOK TO BE IN GOOD SHAPE.
WILL ISSUE THE UPDATE A LITTLE LATER THIS EVENING AND BEGIN TO
LOWER POPS...SOME...ACROSS THE AREA.
PREV DISCUSSION... /ISSUED 609 PM CST SUN NOV 23 2014/
AVIATION 00Z DISCUSSION...
STORM SYSTEM TO PULL EAST OVERNIGHT. WE WILL STILL SEE SOME
RESIDUAL SHOWER ACTIVITY THROUGH THE EVENING HOURS BEFORE THE
PRECIP DECREASES IN COVERAGE AND INTENSITY. OTW...PRESSURE
GRADIENT WILL TIGHTEN OVERNIGHT AND WINDS WILL REMAIN BREEZY AND
GUSTY AT TIMES.
AS FOR CIGS...LOW LEVEL CLOUDINESS WILL PERSIST BUT CIGS WILL
LIFT SOME TOWARD THE END OF THE TAF PD.
PREV DISCUSSION... /ISSUED 340 PM CST SUN NOV 23 2014/
DISCUSSION...IT HAS BEEN A RAINY AND INCREASINGLY BREEZY DAY
ACROSS MID TN. AFTERNOON TEMPERATURES WERE IN THE MID TO UPPER
50S. THE MAIN RAIN SHIELD IS LIFTING ACROSS MID TN...AND SOME
BREAKS IN THE RAIN ARE MOVING INTO THE SW COUNTIES. THESE BREAKS
IN TE RAIN WILL SPREAD ACROSS MID TN OVER THE NEXT COUPLE OF
HOURS...BUT WE WILL KEEP HIGH POPS THROUGH THE EVENING AS RADAR
SHOWS MORE SHOWERS MOVING UP FROM THE SOUTHWEST. THE POPS WILL
DROP OFF MORE SIGNIFICANTLY LATE TONIGHT. NO THUNDERSTORMS HAVE
BEEN OBSERVED TODAY...BUT A LIGHTNING STRIKE OR 2 COULD OCCUR
EARLY THIS EVENING.
THE MAIN CONCERN FOR THIS EVENING THROUGH TONIGHT IS THE WIND
POTENTIAL. A VORT MAX AND SMALL SCALE SURFACE LOW PRESSURE CENTER
FROM WEST CENTRAL MS WILL ZIP UP THE MS RIVER LATE THIS AFTERNOON
AND EVENING...MEETING UP WITH A DEEPENING SYNOPTIC SCALE LOW
PRESSURE FROM OK. A LLJ WILL STRENGTHEN TO 50-60KT. SURFACE WIND
GUSTS WILL REACH OVER 40 MPH AT TIMES. THE MAIN TIME FOR THIS
WILL BE FROM 5 PM TO 10 PM...AND THESE STRONGER GUSTS WILL AFFECT
LOCATIONS MAINLY ALONG AND WEST OF I 65. WE HAVE ALREADY ISSUED A
WIND ADVISORY FOR THE MID STATE WEST OF THE PLATEAU.
FOR LATER TONIGHT THROUGH MONDAY...THE CONSOLIDATED LOW PRESSURE
SYSTEM WILL ACCELERATE ACROSS THE GREAT LAKES REGION AND INTO
EASTERN CANADA. EVEN THROUGH THE LOW WILL BE MOVING AWAY...IT WILL
STRENGTHEN...RESULTING IN STRONG WINDS ACROSS A WIDE AREA. FOR MID
TN...THIS MEANS THAT WINDS WILL INCREASE AGAIN TOWARD
DAYBREAK...WITH SPEEDS OF 20-30 MPH AND SOME 45 MPH THROUGH MONDAY
MORNING. GUSTS OF THAT STRENGTH COULD EASILY BRING DOWN SOME LIMBS
AND WEAKER TREES...AND CAUSE SCATTERED POWER OUTAGES. THERE WILL
CONTINUE TO BE A CHANCE FOR SCATTERED SHOWERS INTO MONDAY
MORNING...THEN DRIER AIR IS EXPECTED MONDAY AFTERNOON. WIND GUSTS
WILL TAPER OFF SLIGHTLY MONDAY AFTERNOON...BUT STILL FREQUENTLY
OVER 30 MPH UNDER PARTLY SUNNY SKIES.
DRY AND COOLER WX MOVES IN FOR MONDAY NIGHT...AND WILL STAY
THROUGH THE REST OF THE WEEK. THERE ARE A COUPLE OF MIDWEEK
SYSTEMS THAT NEED TO BE WATCHED FOR SOME SHOWER POTENTIAL.
MODELS HAVE BEEN VERY INCONSISTENT WITH THESE FEATURES...BUT IT
LOOKS LIKE THEY WILL NOT HAVE MUCH IMPACT ON MID TN. SO...AFTER A
VERY ACTIVE BEGINNING OF THIS WEEK...QUIET CONDITIONS ARE EXPECTED
FOR THE THANKSGIVING HOLIDAY WITH GENERALLY COOLER THAN NORMAL
TEMPS.
13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST MONDAY FOR TNZ005>011-023>033-
056>064-075-077-093>095.
&&
$$
21
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
349 AM CST MON NOV 24 2014
.SHORT TERM /NOW THROUGH TUESDAY/...EXPANDED THE DENSE FOG
ADVISORY TO COVER ALL THE COASTAL AREAS AND GULF WATERS 0-20NM
EAST OF THE COASTLINE. DENSE MARINE FOG ADVECTED IN THROUGH THE
OVERNIGHT HOURS AND HAS CONTINUED ITS N-NW PROGRESSION EVEN
REACHING EASTERN HIDALGO COUNTY. DID ALSO EXTEND THE TIMING
THROUGH 12Z BASED ON THE HRRR NOT BRINGING FROPA THROUGH THE LOWER
VALLEY TILL 12Z AND STRONGER WINDS NOT UNTIL 14Z. SPEAKING OF THE
FRONT...11-3.9 MICRON SHOWS THE FRONT CLEARLY THROUGH MIDDLE TEXAS
COASTAL WATERS AS A FINE LINE OF LOWER STRATUS WITH KRKP AND KCRP
WIND DIRECTIONS SWITCHING TO THE NORTHWEST. EXTRAPOLATING USING
CURRENT SPEED PLACES THE FRONT IN THE LOWER VALLEY BY 12Z MATCHING
UP WITH THE HRRR.
NORTH WINDS WILL PICK UP AFTER THE FRONTAL PASSAGE WITH BREEZY
CONDITIONS THROUGH THE MORNING HOURS WITH WINDS DIMINISHING INTO THE
AFTERNOON HOURS. ALONG THE COAST THE WINDS WILL STAY UP A LITTLE
LONGER THAN MORE INLAND AREAS. WILL BE A NICE AND COOL DAY TODAY
WITH A SOME PASSING HIGH CLOUDS FROM TIME TO TIME. HIGHS WILL BE IN
THE UPPER 60S IN THE RANCHLANDS TO LOWER 70S IN THE VALLEY. SFC HIGH
PRESSURE BUILDS INTO CENTRAL TEXAS OVERNIGHT THEN SINK SOUTHWARDS ON
TUESDAY. WINDS WILL BE FAIRLY LIGHT TONIGHT INTO TUESDAY AND WILL
KEEP SOME CLOUDS CLOUDS AROUND WITH SOUTHWESTERLY FLOW IN THE
MID/UPPER LEVELS UNTIL THE 500MB TROUGH UPSTREAM SWINGS THROUGH
TUESDAY AFTERNOON. MET/MAV TEMPERATURES TONIGHT CAME IN COOLER SO
TRENDED OUR TEMPERATURES DOWNWARD A DEGREE OR TWO ESPECIALLY IN
OUTLYING AREAS. TUESDAY HIGHS ARE A REPEAT OF TODAY.
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...EXTENDED PERIOD
CONTINUES TO LOOK PRETTY QUIET AND LITTLE CHANGE WAS MADE TO THE
PRIOR FORECAST. ALL IN ALL A MILD AND FAIRLY DRY WEEK IS IN THE
WORKS. SHORTWAVE TROUGH WILL BE EXITING THE REGION TUESDAY NIGHT
WITH FLOW ALOFT VEERING TO THE NORTHWEST. THE NORTHWEST FLOW WILL
BRING DRY AIR OVER THE REGION...RESULTING IN MOSTLY CLEAR SKIES
TUESDAY NIGHT INTO THURSDAY. TUESDAY NIGHT WILL BE THE COLDEST OF THE
WEEK AS CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPERATURES TO FALL
INTO THE LOWER AND MID 40S. BELOW NORMAL TEMPERATURES WILL CONTINUE
WEDNESDAY THROUGH THURSDAY...WITH HIGHS IN THE LOWER 70S AND LOWS IN
THE MID TO UPPER 40S NORTH AND UPPER 40S TO LOWER 50S SOUTH.
TEMPERATURES AND CLOUD COVER BEGIN TO INCREASE ON FRIDAY AS MODERATE
SOUTHEASTERLY FLOW RETURNS. A 500 MB TROUGH/CUTOFF LOW DEVELOPS OVER
NORTHERN MEXICO ON THURSDAY AND SLOWLY NUDGES EAST THROUGH THE
WEEKEND. THE WEAK TROUGH COMBINED WITH THE INCREASED MOISTURE COULD
RESULT IN A FEW STREAMER SHOWERS OVER THE COASTAL WATERS ON SUNDAY.
&&
.MARINE...
NOW THROUGH TUESDAY...A FRONT WILL SWEEP ACROSS THE AREA EARLY
THIS MORNING WITH WINDS SWITCHING TO THE NORTH IN ITS WAKE. STRONG
NORTH WINDS WILL ROUGHEN SEAS AND A SMALL CRAFT ADVISORY HAS BEEN
ISSUED FOR THE GULF OF MEXICO WATERS OF THE LOWER TEXAS COAST
THROUGH MONDAY AFTERNOON. ROUGH SEAS WILL BECOME MORE MODERATE
MONDAY NIGHT INTO AS WIND SPEEDS DECREASE. HOWEVER...A SECONDARY
SURGE OF STRONGER WINDS LOOK TO INVADE AT LEAST THE 20-60NM WATERS
TUESDAY AROUND THE DEPARTING SYSTEM WHICH SMALL CRAFT ADVISORIES
MAY BE NEEDED FOR THE FAR OFFSHORE WATERS FOR SEAS RISING BACK UP
TO AROUND 7 FEET.
TUESDAY NIGHT THROUGH FRIDAY...NORTH WINDS TUESDAY EVENING WILL
BEGIN TO DIMINISH AND SEAS WILL BEGIN TO SUBSIDE AS THE PRESSURE
GRADIENT WEAKENS. SMALL CRAFT ADVISORIES MAY NEEDED TUESDAY NIGHT
FOR THE FAR OFFSHORE WATERS FOR SEAS OF 7 FEET. SEAS WILL CONTINUE
TO SUBSIDE THROUGH THE DAY WEDNESDAY. LIGHT TO MODERATE SOUTHEAST
WINDS AND LOW SEAS WILL PREVAIL THURSDAY AND FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 70 51 70 49 / 0 0 0 0
BROWNSVILLE 72 51 71 45 / 0 0 0 0
HARLINGEN 70 48 71 44 / 0 0 0 0
MCALLEN 71 47 72 43 / 0 0 0 0
RIO GRANDE CITY 71 47 70 42 / 0 0 0 0
SOUTH PADRE ISLAND 70 57 70 54 / 0 0 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR TXZ251-
254>257.
GM...DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR GMZ130-
132-135-150-155.
SMALL CRAFT ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR GMZ150-
155-170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55/58/CAMPBELL
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
320 AM CST MON NOV 24 2014
.SHORT TERM (TODAY THROUGH TUESDAY)...COOLER WEATHER ON THE WAY AS
THE COLD FRONT MOVES THROUGH SOUTH TEXAS EARLY THIS MORNING. TOO DRY
NEAR THE SURFACE FOR SHOWERS...AND THAT DRIER AIR IN THE LOWER AND
MID LEVELS REMAINS (MOISTENS UP 700MB AND ABOVE TONIGHT). PRETTY
POTENT UPPER TROUGH AND JET IMPACT AREA OVERNIGHT AND TUESDAY
MORNING...AND MOISTURE 700MB AND ABOVE DUE TO LIFT MAY PRODUCE A
SPRINKLE OR TWO OVER EXTREME EASTERN AREAS AND COASTAL WATERS
(MAINLY CLOUDS THOUGH). HOWEVER...SINCE SPRINKLES WILL NOT MENTION.
WILL GO WITH PARTLY TO MOSTLY CLOUDY SKIES TUESDAY MORNING AS THERE
SHOULD BE SUFFICIENT MID AND HIGH CLOUDS TO PRECLUDE SOME SUN AT
LEAST UNTIL THE AFTERNOON WHEN AREA GETS ON THE SUBSIDENCE SIDE OF
UPPER SYSTEM. AM GOING TO GO ON THE COOLER SIDE OF GUIDANCE FOR
TEMPERATURES TODAY AND TUESDAY...BUT MORE ON THE WARM SIDE FOR
TONIGHT AS MID AND HIGH CLOUDS WILL PREVENT TEMPERATURES FROM
FALLING TOO MUCH. WIND FORECAST GENERALLY A BLEND OF RUC13 AND
NAM12 FOR THE MORNING...THEN A BLEND OF THE NAM AND MOS FOR THE
AFTERNOON THROUGH TUESDAY.
&&
.MARINE (TODAY THROUGH TUESDAY)...WILL ADJUST SCA TO KEEP THE
NEARSHORE IN A BIT LONGER (TIL ABOUT NOON)...AND THE OFFSHORE TIL
ABOUT 5 PM...GIVEN WIND AND WAVE FORECAST. SCA CONDITIONS WILL
LIKELY DEVELOP AGAIN LATE TONIGHT OR TUESDAY. HOWEVER...WILL HOLD
OFF ON HAVING AN SCA FOR THAT AT THIS TIME SINCE 3RD PERIOD AND
WINDS AND WAVES WILL TAPER OFF SOME TONIGHT (AND BORDERLINE SCA AT
THAT). WILL LET NEXT SHIFT TAKE A PEEK AT THIS.
&&
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...GENERALLY BENIGN
FORECAST THROUGH THE LONG TERM PERIOD...BUT A FEW DETAILS TO
CONSIDER IN THE OVERALL PATTERN. UPPER LEVEL DISTURBANCE PUSHING
EAST OF THE AREA AT ONSET OF LONG TERM PERIOD. SHOULD BE CLEARING
OUT QUICKLY TUESDAY NIGHT...IF NOT ALREADY CLEARED LATE TUESDAY
AFTERNOON. VERY DRY AIR FILTERS IN WITH REINFORCING RIDGE WITH PWATS
WELL BELOW HALF INCH OVER MUCH OF THE AREA. A COUPLE OF WEAK
SHORTWAVES NOTED IN THE UPPER LEVEL PATTERN FRI EVENING AND SUNDAY.
CONFIDENT THAT AIR WILL STILL BE DRY FOR FRIDAY EVENING SHORT
WAVE...BUT SUNDAY WEAK DISTURBANCE COULD HAVE THE POTENTIAL FOR SOME
POPS AS A SOUTHERLY FLOW WILL HAVE DEVELOPED LATE IN THE WEEK. AT
THIS TIME WITH A MAINLY SOUTHERLY FLOW RATHER THAN SOUTHEAST...NOT
THINKING TOO HIGHLY OF SLIGHT CHANCE POPS SOME MODELS ARE
INDICATING. WILL KEEP THE FORECAST DRY AT THIS TIME.
TEMPS FOR THE WEEK SHOULD BE WAVERING AROUND NORMAL FOR HIGHS.
SLIGHTLY BELOW NORMAL LOWS ARE LIKELY EARLY IN THE WEEK WITH HIGH
PRESSURE AND CLEAR SKIES...BUT WILL WARM TO ABOVE NORMAL BY THE
WEEKEND AS MOISTURE GRADUALLY WORKS ITS WAY BACK IN.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 67 45 69 44 70 / 0 0 0 0 0
VICTORIA 65 41 64 41 70 / 0 10 10 0 0
LAREDO 68 48 69 41 73 / 0 0 0 0 0
ALICE 67 43 70 41 72 / 0 0 0 0 0
ROCKPORT 67 48 65 52 69 / 0 10 10 0 0
COTULLA 66 42 67 39 72 / 0 0 0 0 0
KINGSVILLE 68 44 69 42 72 / 0 0 0 0 0
NAVY CORPUS 67 52 68 50 69 / 0 10 10 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS
OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
GW/86...SHORT TERM
PZ/83...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS BLACKSBURG VA
100 AM EST MON NOV 24 2014
.SYNOPSIS...
A WARM FRONT EXPECTED TO SHIFT NORTH OF US OVERNIGHT...RESULTING
IN A WARMUP FOR MONDAY...AHEAD OF A COLD FRONT TO OUR WEST. THE COLD
FRONT MOVES THROUGH MONDAY NIGHT INTO TUESDAY...RETURNING
TEMPERATURES TO BELOW NORMAL FOR THE REST OF THE WEEK. A STORM
MOVES ALONG THE SOUTHEAST COAST MIDWEEK WHICH COULD LEAD TO A
WHITE THANKSGIVING FOR SOME.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1257 AM EST MONDAY...
QUICK UPDATE TO DROP THE GOING WIND ADVISORY OVER THE WEST AS
EXPECTING WINDS TO TURN MORE SW SHORTLY WITH SOME DECREASE IN
SPEEDS OVERNIGHT. ALSO WITH THE FAST EXODUS OF THE RAINFALL...CUT
WAY BACK TO JUST LOW POPS FOR THE MOST PART THROUGH MORNING GIVEN
DRYING ALOFT AND LITTLE RESIDUAL FOCUS.
PREVIOUS DISCUSSION AS OF 1020 PM EST SUNDAY...
SHIELD OF RAIN MOVING ACROSS FASTER AND THIS WAS HANDLED FAIRLY
WELL BY THE LATEST RUNS OF THE HRRR AND 18Z LOCAL WRF. WILL DRY
THINGS OUT FASTER THAN EARLIER FORECAST...WITH MODEL SOUNDING
SUGGESTING A SMALL 1-3 HOUR WIND OF DRIZZLE AS DEEPER MOISTURE
PULLS OUT LEAVING BEHIND SHALLOW MOISTURE BELOW 8H. WILL JUST SEE
SPOTTY SHOWERS OVERNIGHT INTO MONDAY MORNING.
AS FOR THE WINDS...THE CORE OF THE 8H JET IS OVERHEAD AND THE FLOW
WILL START TO SHIFT MORE SOUTH THEN SSW AFTER MIDNIGHT. THE ENDING
TIME FOR 1 AM STILL SEEMS REASONABLE. HAVE NOT REALLY HAD ANY
GUSTS OVER 50 MPH...THOUGH THE TAZEWELL MIDDLE SCHOOL WEATHERBUG
SITE DID SHOW A 60 MPH GUST EARLIER.
TEMPS HAVE BUMPED UP IN SOUTHSIDE VA/NW NC PIEDMONT AS WEDGE
DISSIPATES. THE THREAT OF THUNDER LOOKS LIMITED SO REMOVED IT AS
RAIN MOVING OUT SOON.
DRY SLOT AND CLEARING IS PROBLEMATIC BUT THINK THE MOUNTAIN EMPIRE
INTO SE WV AND PORTIONS OF THE NEW RIVER VALLEY AND TN/NC BORDER
AREA WILL SEE SUNSHINE IN THE MORNING WHILE LOW LVL MOISTURE
REMAINS BANKED INTO THE BLUE RIDGE A LITTLE WHILE...AND POINTS
EAST.
PREVIOUS VALID DISCUSSION...
BROAD UPPER LEVEL 500H TROUGH WILL ENCOMPASS MUCH OF THE CENTRAL
CONUS FOR MONDAY TO START THE WORKWEEK. A COLD FRONT WILL APPROACH
FROM THE WEST MONDAY. A WARM SECTOR SOUTHERLY WINDS WILL RESULT IN A
BREEZY MILD MONDAY. 1000-500MB THICKNESS VALUES OF 565-570DM AND
850H TEMPERATURES AROUND PLUS 10C SUPPORT SURFACE TEMPERATURES FROM
AROUND 60 DEGREES IN THE MOUNTAINS TO THE LOWER 70S IN THE PIEDMONT.
THE SURFACE COLD FRONT CROSSES THE MOUNTAINS LATE IN THE DAY... WITH
GFS SOLUTION A LITTLE QUICKER THAN THE NAM/ECMWF.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 338 PM EST SUNDAY...
ON MONDAY NIGHT LOW LEVEL MOISTURE IS BANKED UP AGAINST THE WESTERN
SLOPES OF THE APPALACHIANS. MODELS ERODE LOW LEVEL MOISTURE ON
TUESDAY MORNING.
OVERALL PATTERN THIS TIME FRAME IS FOR SPLIT FLOW WITH AN ACTIVE
NORTHERN STREAM ALONG THE CANADIAN/NORTHERN U.S. BORDER AND SOUTHERN
STREAM THAT HAS A STRONG SHORT WAVE AT THE BASE OF THE TROF OVER THE
LOWER MISSISSIPPI VALLEY BY LATE TUESDAY. EVOLUTION AND TIMING OF
LONG WAVE TROF FROM POSITIVE TILT TO NEGATIVE TILT AND AMOUNT OF
PHASING BETWEEN THE TWO JET STREAMS WILL IMPACT THE RESULTING TRACK
OF THE GULF TO EAST COAST SURFACE LOW AND LOCATION OF THE HEAVIEST
PRECIPITATION. AT THIS TIME SPREAD IN DIFFERENT MODELS IS LARGE.
HIGHEST CONFIDENCE IS WITH THE TIMING BUT MUCH LOWER WITH THE
LOCATION AND TYPE OF PRECIPITATION. WILL BE LEANING TOWARD BLEND OF
THE ECMWF AND GFS AS SUGGESTED BY WPC.
MODELS SHOW MID ATLANTIC REGION IN THE RIGHT REAR QUADRANT OF A 170
KNOT UPPER JET BY LATE TUESDAY NIGHT. AT THE SURFACE THE COLD FRONT
MOVES OFF THE EAST COAST MONDAY NIGHT THEN HIGH PRESSURE BUILDS FROM
THE TENNESSEE VALLEY INTO THE MID ATLANTIC STATES ON TUESDAY. LOW
PRESSURE DEVELOPS IN THE GULF OF MEXICO ON TUESDAY...THEN TRACKS
ACROSS FLORIDA TUESDAY NIGHT. THE LOW SHOULD BE OFF THE SOUTH
CAROLINA COAST ON WEDNESDAY MORNING AS IT MOVES NORTHEAST AND BEGINS
TO DEEPEN.
ONCE THE LOCATION OF THE PRECIPITATION IS DETERMINED...TEMPERATURES
WILL INFLUENCE WHAT TYPE OF PRECIPITATION WILL OCCUR. EVEN TAKING THE
COOLER MET/SREF GUIDANCE FOR TEMPERATURES ON TUESDAY NIGHT AND
WEDNESDAY...SURFACE VALUES MAY STILL BE TOO WARM EAST OF THE BLUE
RIDGE TO SUPPORT ANYTHING BUT RAIN. HAVE USED PARTIAL THICKNESS
VALUES...MAINLY FROM THE GFS/ECMWF TO PLACE RAIN/SNOW LINE. THIS
WILL CHANGE AS THE EVENT DRAWS CLOSER.
LOOKED AT PROBABILITY FOR SNOW AND CORRELATION WITH PAST ANALOG
EVENTS. APPEARS THERE IS AT LEAST THE POTENTIAL FOR SOME WINTER
PRECIPITATION. SINCE WEDNESDAY IS A MAJOR TRAVEL DAY WILL MENTION
POTENTIAL FOR WINTER PRECIPITATION IN THE HAZARDOUS WEATHER
OUTLOOK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 130 PM EST SUNDAY...
THIS PORTION OF THE FORECAST STARTS WITH THE AFTERMATH OF WHAT
UNFOLDS TUESDAY NIGHT INTO WEDNESDAY EVENING. GIVEN THERE STILL IS
GENEROUS UNCERTAINTY IN THOSE EVENTS...THE EVENTS AFTERWARDS ARE
EQUALLY CHALLENGING. THE GENERAL CONSENSUS IS FOR A LOW/TROUGH TO
DEEPEN ACROSS THE GREAT LAKES/OHIO VALLEY AS THE SYSTEM ALONG THE
COAST HEADS NORTHEAST...AND MAKES WAY FOR THE UPSTREAM SYSTEM TO
ENTER OUR REGION. THE PAST FEW DAYS...GUIDANCE HAS TRANSITIONED THIS
SYSTEM FROM A SLOWER...MORE AMPLIFIED SYSTEM INTO ONE THAT IS MORE
PROGRESSIVE AND THE BULK OF ITS ENERGY REMAINS NORTH OF THE REGION
AS IT MOVES EASTWARD. THAT TREND CONTINUES TODAY. OUR FORECAST WILL
REFLECT LITTLE CHANGE FROM THE PRIOR DURING THE THURSDAY THROUGH
FRIDAY TIMEFRAME. THE HIGHLIGHTS HERE ARE UPSLOPE RAIN/SNOW SHOWERS
ACROSS SOUTHEAST WEST VIRGINIA AND NEIGHBORING COUNTIES OF SOUTHWEST
VIRGINIA. A DECENT NORTHWEST FLOW WILL HELP CLOUDS TO A MINIMUM EAST
OF THE CREST OF THE BLUE RIDGE AND ADD A TOUCH OF A WARMING
INFLUENCE. PARTLY TO MOSTLY CLOUDY SKIES AND COOLER TEMPERATURES
WILL BE THE RULE FOR THE MOUNTAINS.
SATURDAY INTO SUNDAY THE REGION TRANSITIONS INTO MORE OF A ZONAL
PATTERN. THERE IS CONSISTENCY IN EACH MODEL CONCERNING THAT FEATURE.
WHAT VARIES SIGNIFICANTLY IS THE TIMING...TRACK AND SPEED OF A
DISTURBANCE MOVING WITHIN THIS ZONAL FLOW THAT MAY OR MAY NOT IMPACT
OUR REGION. AT THIS TIME...HAVE PLACED THE GREATEST FORECAST WEIGHT
ON A MODEL CONSENSUS THAT OFFERS A SMALL CHANCE OF LIGHT RAIN/SNOW
MAINLY IN THE WESTERN PARTS OF THE AREA SATURDAY NIGHT INTO EARLY
SUNDAY WITH TEMPERATURES TRENDING MILDER OVER THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 1150 PM EST SUNDAY...
RAIN HAS MOVED OUT OF THE REGION WITH SPOTTY DRIZZLE AND ISOLATED
SHOWERS REMAINING INTO EARLY MORNING. OVERALL LOOKING AT MVFR/IFR
CIGS WITH LOW LVL WIND SHEAR EARLY ON...THEN LLJ SHIFTS OUT BY
DAWN WITH CIGS STARTING TO LIFT THROUGH LATE MONDAY MORNING AS THE
SFC FLOW TURNS SSW TO SW. GUSTY WINDS AND VFR CIGS SHOULD OCCUR
MOST OF THE DAY MONDAY...WITH WINDS STARTING TO WIND DOWN LATER IN
THE DAY. WITH FRONTAL BOUNDARY MOVING IN CIGS SHOULD BE STAYING
HOVERING NEAR MVFR/VFR HEIGHTS WITH CONFIDENCE LOW AS MODELS VARY
ON DEPTH OF MOISTURE INTO MONDAY EVENING.
EXTENDED DISCUSSION...
WINDS WILL STAY GUSTY MONDAY NIGHT BEHIND COLD FRONT....WITH
POTENTIAL FOR SUB VFR CIGS IN THE MTNS...WHILE VFR IS EXPECTED TO
THE EAST. ANOTHER STORM SYSTEM IS EXPECTED TO MOVE UP THE
SOUTHEAST COAST BY EARLY WEDNESDAY WHICH MAY BRING WINTRY PRECIP
TO THE AREA ALONG WITH SUB VFR AT ALL SITES. LOOKS LIKE FLIGHTS
WILL BE IMPACTED GREATLY ACROSS THE MID ATLANTIC INTO THE
NORTHEAST WITH THIS SYSTEM WITH STRONG WINDS EXPECTED ALONG WITH
WIDESPREAD PRECIPITATION. AROUND HERE LOOKS LIKE WE WILL
EXPERIENCE SUB VFR AT LEAST WED INTO EARLY THANKSGIVING BEFORE
HIGH PRESSURE WORKS IN FROM THE WEST...THOUGH WINDS MAY STAY UP
THROUGH THU NIGHT...WITH UPSLOPE LOWER CIGS AT BLF/LWB.
&&
.EQUIPMENT...
AS OF 215 PM EST FRIDAY...
THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT
OF SERVICE UNTIL PARTS ARRIVE TO REPLACE THE SENSOR. UNTIL THEN
THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS
STAFFED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KK/MBS/WP
NEAR TERM...JH/KK/WP
SHORT TERM...AMS
LONG TERM...DS
AVIATION...KK/WP
EQUIPMENT...RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1153 PM EST SUN NOV 23 2014
.SYNOPSIS...
A WARM FRONT EXPECTED TO SHIFT NORTH OF US OVERNIGHT...RESULTING
IN A WARMUP FOR MONDAY...AHEAD OF A COLD FRONT TO OUR WEST. THE COLD
FRONT MOVES THROUGH MONDAY NIGHT INTO TUESDAY...RETURNING
TEMPERATURES TO BELOW NORMAL FOR THE REST OF THE WEEK. A STORM
MOVES ALONG THE SOUTHEAST COAST MIDWEEK WHICH COULD LEAD TO A
WHITE THANKSGIVING FOR SOME.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 1020 PM EST SUNDAY...
SHIELD OF RAIN MOVING ACROSS FASTER AND THIS WAS HANDLED FAIRLY
WELL BY THE LATEST RUNS OF THE HRRR AND 18Z LOCAL WRF. WILL DRY
THINGS OUT FASTER THAN EARLIER FORECAST...WITH MODEL SOUNDING
SUGGESTING A SMALL 1-3 HOUR WIND OF DRIZZLE AS DEEPER MOISTURE
PULLS OUT LEAVING BEHIND SHALLOW MOISTURE BELOW 8H. WILL JUST SEE
SPOTTY SHOWERS OVERNIGHT INTO MONDAY MORNING.
AS FOR THE WINDS...THE CORE OF THE 8H JET IS OVERHEAD AND THE FLOW
WILL START TO SHIFT MORE SOUTH THEN SSW AFTER MIDNIGHT. THE ENDING
TIME FOR 1 AM STILL SEEMS REASONABLE. HAVE NOT REALLY HAD ANY
GUSTS OVER 50 MPH...THOUGH THE TAZEWELL MIDDLE SCHOOL WEATHERBUG
SITE DID SHOW A 60 MPH GUST EARLIER.
TEMPS HAVE BUMPED UP IN SOUTHSIDE VA/NW NC PIEDMONT AS WEDGE
DISSIPATES. THE THREAT OF THUNDER LOOKS LIMITED SO REMOVED IT AS
RAIN MOVING OUT SOON.
DRY SLOT AND CLEARING IS PROBLEMATIC BUT THINK THE MOUNTAIN EMPIRE
INTO SE WV AND PORTIONS OF THE NEW RIVER VALLEY AND TN/NC BORDER
AREA WILL SEE SUNSHINE IN THE MORNING WHILE LOW LVL MOISTURE
REMAINS BANKED INTO THE BLUE RIDGE A LITTLE WHILE...AND POINTS
EAST.
PREVIOUS VALID DISCUSSION...
BROAD UPPER LEVEL 500H TROUGH WILL ENCOMPASS MUCH OF THE CENTRAL
CONUS FOR MONDAY TO START THE WORKWEEK. A COLD FRONT WILL APPROACH
FROM THE WEST MONDAY. A WARM SECTOR SOUTHERLY WINDS WILL RESULT IN A
BREEZY MILD MONDAY. 1000-500MB THICKNESS VALUES OF 565-570DM AND
850H TEMPERATURES AROUND PLUS 10C SUPPORT SURFACE TEMPERATURES FROM
AROUND 60 DEGREES IN THE MOUNTAINS TO THE LOWER 70S IN THE PIEDMONT.
THE SURFACE COLD FRONT CROSSES THE MOUNTAINS LATE IN THE DAY... WITH
GFS SOLUTION A LITTLE QUICKER THAN THE NAM/ECMWF.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 338 PM EST SUNDAY...
ON MONDAY NIGHT LOW LEVEL MOISTURE IS BANKED UP AGAINST THE WESTERN
SLOPES OF THE APPALACHIANS. MODELS ERODE LOW LEVEL MOISTURE ON
TUESDAY MORNING.
OVERALL PATTERN THIS TIME FRAME IS FOR SPLIT FLOW WITH AN ACTIVE
NORTHERN STREAM ALONG THE CANADIAN/NORTHERN U.S. BORDER AND SOUTHERN
STREAM THAT HAS A STRONG SHORT WAVE AT THE BASE OF THE TROF OVER THE
LOWER MISSISSIPPI VALLEY BY LATE TUESDAY. EVOLUTION AND TIMING OF
LONG WAVE TROF FROM POSITIVE TILT TO NEGATIVE TILT AND AMOUNT OF
PHASING BETWEEN THE TWO JET STREAMS WILL IMPACT THE RESULTING TRACK
OF THE GULF TO EAST COAST SURFACE LOW AND LOCATION OF THE HEAVIEST
PRECIPITATION. AT THIS TIME SPREAD IN DIFFERENT MODELS IS LARGE.
HIGHEST CONFIDENCE IS WITH THE TIMING BUT MUCH LOWER WITH THE
LOCATION AND TYPE OF PRECIPITATION. WILL BE LEANING TOWARD BLEND OF
THE ECMWF AND GFS AS SUGGESTED BY WPC.
MODELS SHOW MID ATLANTIC REGION IN THE RIGHT REAR QUADRANT OF A 170
KNOT UPPER JET BY LATE TUESDAY NIGHT. AT THE SURFACE THE COLD FRONT
MOVES OFF THE EAST COAST MONDAY NIGHT THEN HIGH PRESSURE BUILDS FROM
THE TENNESSEE VALLEY INTO THE MID ATLANTIC STATES ON TUESDAY. LOW
PRESSURE DEVELOPS IN THE GULF OF MEXICO ON TUESDAY...THEN TRACKS
ACROSS FLORIDA TUESDAY NIGHT. THE LOW SHOULD BE OFF THE SOUTH
CAROLINA COAST ON WEDNESDAY MORNING AS IT MOVES NORTHEAST AND BEGINS
TO DEEPEN.
ONCE THE LOCATION OF THE PRECIPITATION IS DETERMINED...TEMPERATURES
WILL INFLUENCE WHAT TYPE OF PRECIPITATION WILL OCCUR. EVEN TAKING THE
COOLER MET/SREF GUIDANCE FOR TEMPERATURES ON TUESDAY NIGHT AND
WEDNESDAY...SURFACE VALUES MAY STILL BE TOO WARM EAST OF THE BLUE
RIDGE TO SUPPORT ANYTHING BUT RAIN. HAVE USED PARTIAL THICKNESS
VALUES...MAINLY FROM THE GFS/ECMWF TO PLACE RAIN/SNOW LINE. THIS
WILL CHANGE AS THE EVENT DRAWS CLOSER.
LOOKED AT PROBABILITY FOR SNOW AND CORRELATION WITH PAST ANALOG
EVENTS. APPEARS THERE IS AT LEAST THE POTENTIAL FOR SOME WINTER
PRECIPITATION. SINCE WEDNESDAY IS A MAJOR TRAVEL DAY WILL MENTION
POTENTIAL FOR WINTER PRECIPITATION IN THE HAZARDOUS WEATHER
OUTLOOK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 130 PM EST SUNDAY...
THIS PORTION OF THE FORECAST STARTS WITH THE AFTERMATH OF WHAT
UNFOLDS TUESDAY NIGHT INTO WEDNESDAY EVENING. GIVEN THERE STILL IS
GENEROUS UNCERTAINTY IN THOSE EVENTS...THE EVENTS AFTERWARDS ARE
EQUALLY CHALLENGING. THE GENERAL CONSENSUS IS FOR A LOW/TROUGH TO
DEEPEN ACROSS THE GREAT LAKES/OHIO VALLEY AS THE SYSTEM ALONG THE
COAST HEADS NORTHEAST...AND MAKES WAY FOR THE UPSTREAM SYSTEM TO
ENTER OUR REGION. THE PAST FEW DAYS...GUIDANCE HAS TRANSITIONED THIS
SYSTEM FROM A SLOWER...MORE AMPLIFIED SYSTEM INTO ONE THAT IS MORE
PROGRESSIVE AND THE BULK OF ITS ENERGY REMAINS NORTH OF THE REGION
AS IT MOVES EASTWARD. THAT TREND CONTINUES TODAY. OUR FORECAST WILL
REFLECT LITTLE CHANGE FROM THE PRIOR DURING THE THURSDAY THROUGH
FRIDAY TIMEFRAME. THE HIGHLIGHTS HERE ARE UPSLOPE RAIN/SNOW SHOWERS
ACROSS SOUTHEAST WEST VIRGINIA AND NEIGHBORING COUNTIES OF SOUTHWEST
VIRGINIA. A DECENT NORTHWEST FLOW WILL HELP CLOUDS TO A MINIMUM EAST
OF THE CREST OF THE BLUE RIDGE AND ADD A TOUCH OF A WARMING
INFLUENCE. PARTLY TO MOSTLY CLOUDY SKIES AND COOLER TEMPERATURES
WILL BE THE RULE FOR THE MOUNTAINS.
SATURDAY INTO SUNDAY THE REGION TRANSITIONS INTO MORE OF A ZONAL
PATTERN. THERE IS CONSISTENCY IN EACH MODEL CONCERNING THAT FEATURE.
WHAT VARIES SIGNIFICANTLY IS THE TIMING...TRACK AND SPEED OF A
DISTURBANCE MOVING WITHIN THIS ZONAL FLOW THAT MAY OR MAY NOT IMPACT
OUR REGION. AT THIS TIME...HAVE PLACED THE GREATEST FORECAST WEIGHT
ON A MODEL CONSENSUS THAT OFFERS A SMALL CHANCE OF LIGHT RAIN/SNOW
MAINLY IN THE WESTERN PARTS OF THE AREA SATURDAY NIGHT INTO EARLY
SUNDAY WITH TEMPERATURES TRENDING MILDER OVER THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 1150 PM EST SUNDAY...
RAIN HAS MOVED OUT OF THE REGION WITH SPOTTY DRIZZLE AND ISOLATED
SHOWERS REMAINING INTO EARLY MORNING. OVERALL LOOKING AT MVFR/IFR
CIGS WITH LOW LVL WIND SHEAR EARLY ON...THEN LLJ SHIFTS OUT BY
DAWN WITH CIGS STARTING TO LIFT THROUGH LATE MONDAY MORNING AS THE
SFC FLOW TURNS SSW TO SW. GUSTY WINDS AND VFR CIGS SHOULD OCCUR
MOST OF THE DAY MONDAY...WITH WINDS STARTING TO WIND DOWN LATER IN
THE DAY. WITH FRONTAL BOUNDARY MOVING IN CIGS SHOULD BE STAYING
HOVERING NEAR MVFR/VFR HEIGHTS WITH CONFIDENCE LOW AS MODELS VARY
ON DEPTH OF MOISTURE INTO MONDAY EVENING.
EXTENDED DISCUSSION...
WINDS WILL STAY GUSTY MONDAY NIGHT BEHIND COLD FRONT....WITH
POTENTIAL FOR SUB VFR CIGS IN THE MTNS...WHILE VFR IS EXPECTED TO
THE EAST. ANOTHER STORM SYSTEM IS EXPECTED TO MOVE UP THE
SOUTHEAST COAST BY EARLY WEDNESDAY WHICH MAY BRING WINTRY PRECIP
TO THE AREA ALONG WITH SUB VFR AT ALL SITES. LOOKS LIKE FLIGHTS
WILL BE IMPACTED GREATLY ACROSS THE MID ATLANTIC INTO THE
NORTHEAST WITH THIS SYSTEM WITH STRONG WINDS EXPECTED ALONG WITH
WIDESPREAD PRECIPITATION. AROUND HERE LOOKS LIKE WE WILL
EXPERIENCE SUB VFR AT LEAST WED INTO EARLY THANKSGIVING BEFORE
HIGH PRESSURE WORKS IN FROM THE WEST...THOUGH WINDS MAY STAY UP
THROUGH THU NIGHT...WITH UPSLOPE LOWER CIGS AT BLF/LWB.
&&
.EQUIPMENT...
AS OF 215 PM EST FRIDAY...
THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT
OF SERVICE UNTIL PARTS ARRIVE TO REPLACE THE SENSOR. UNTIL THEN
THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS
STAFFED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR VAZ007-009.
NC...NONE.
WV...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR WVZ042.
&&
$$
SYNOPSIS...KK/MBS/WP
NEAR TERM...KK/WP
SHORT TERM...AMS
LONG TERM...DS
AVIATION...KK/WP
EQUIPMENT...RAB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
330 AM CST MON NOV 24 2014
.UPDATE...
ISSUED AT 330 AM CST MON NOV 24 2014
HAVE EXPANDED WINTER WEATHER ADVISORY AND HOISTED A WINTER STORM
WARNING FOR PORTIONS OF THE ARX FORECAST AREA. SEE
WATCH/WARNING/ADVISORY SECTION BELOW.
CURRENTLY...A DEEPENING LOW WAS LOCATED OVER LOWER MICHIGAN WITH
NORTHWEST WINDS ON THE BACKSIDE...STARTING TO DRAW COLDER AIR IN
OVER THE ARX FORECAST AREA. RADAR/SURFACE OBSEVATIONS SHOWING MAINLY
AREAS OF RAIN EAST OF THE MISSISSIPPI RIVER WHILE WEST OF THE
MISSISSIPPI...RAIN WAS CHANGING/HAS MADE THE CHANGE OVER TO SNOW.
WATER VAPOR IMAGERY SHOWING A VERY POTENT MID-LEVEL SHORTWAVE TROUGH
EJECTING NORTHEAST OUT OF NORTHEAST MISSOURI. PLAN ON THIS WAVE
LIFTING NORTHEAST ACROSS WISCONSIN TODAY WITH STRENGTHENING 700-
500MB FRONTOGENESIS. IN ADDITION...BUFKIT SOUNDING/-12 TO -18C OMEGA
FOR GOOD DENDRITIC GROWTH WILL BE BLOSSOMING FOR AREA EAST OF THE
MISSISSIPPI RIVER LATER THIS MORNING THROUGH THE AFTERNOON FOR SOME
GOOD SNOW RATES. COULD SEE SNOW RATES OF 1/2-1 INCH/HR. RIGHT
NOW...LOOKS LIKE AREAS OF CENTRAL WI WOULD BE IMPACTED THE MOST WITH
INDICATIONS OF SNOW TOTALS AROUND 6 INCHES FOR JUNEAU/ADAMS COUNTIES
FROM LATER THIS MORNING INTO TONIGHT. FARTHER WEST...TO THE
MISSISSIPPI RIVER VALLEY...IT APPERAS ANYWHERE FROM 3-5 INCHES OF
ACCUMULATION CAN BE EXPECTED THIS MORNING INTO THIS
EVENING...TAPERING OFF BY MIDNIGHT. WEST OF THE MISSISSIPPI RIVER
VALLEY...WHICH WILL BE DISPLACED FROM THE BETTER STORM
DYNAMICS...PLAN ON SNOW TOTALS TODAY THROUGH THIS EVENING OF 1-2
INCHES. TO COMPLICATE MATTERS LOOKS LIKE GUSTY NORTHWEST WINDS OF 15
TO 25 MPH WITH GUSTS AROUND 35 MPH OVER MORE WIND PRONE AREAS WILL
PRODUCE SOME BLOWING AND DRIFTING OF THE SNOW.
AS SUCH...HOISTED A WINTER STORM WARNING FOR JUNEAU/ADAMS COUNTY IN
CENTRAL WISCONSIN VALID 9 AM TODAY THROUGH 6 AM TUESDAY AND EXPANDED
THE WINTER WEATHER ADVISORY...TO INCLUDE COUNTIES BORDERING THE
MISSISSIPPI UP TO THE WARNING IN CENTRAL WI.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
COMPLEX SHORT TERM PERIOD WITH MANY ISSUES TO DEAL WITH.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A VERY ACTIVE PATTERN OVER THE WEST HALF OF THE COUNTRY.
UPPER LOWS WERE PRESENT OVER NORTHERN MISSISSIPPI AND NORTH
DAKOTA...WHILE POTENT SHORTWAVES WERE NOTED IN SOUTHWEST OKLAHOMA...
NORTHERN NEW MEXICO AND OVER WASHINGTON STATE. THE FORECAST AREA
LIES IN SOUTHWEST FLOW...WHERE WATER VAPOR IMAGERY SHOWS A NICE WARM
CONVEYOR BELT OVER THE EAST HALF OF THE AREA. THIS TRANSLATES TO A
BAND OF RAIN FROM EASTERN IA THROUGH SOUTHWEST WI TO THE GRB AREA.
RAP PRECIPITABLE WATER VALUES ARE AROUND 1 INCH ALONG AND SOUTH OF
THE BAND...COMPARED TO 0.75 INCHES OVER OUR NORTHWEST CWA WHERE
CONDITIONS ARE DRY. ALTHOUGH ITS DRIER IN PRECIPITABLE WATER...
DRIZZLE AND/OR LIGHT RAIN HAS BEEN PRESENT DUE TO SATURATED LOW
LEVELS AND WEAK ISENTROPIC LIFT ON THE 285-290K SURFACES. TO THE
WEST...A COLD FRONT WAS PRESENT ALONG I-35 WITH A WEAKENING BAND OF
RAIN RIGHT BEHIND IT...ASSOCIATED WITH MID LEVEL FRONTOGENESIS.
TEMPERATURES AHEAD OF THE FRONT ACROSS THE FORECAST AREA WERE MAINLY
IN THE 40S TO LOW 50S...COLDEST OVER THE DEEPER SNOWPACK IN TAYLOR
COUNTY. IN THE WAKE OF THE FRONT...READINGS WERE IN THE 30S AND
40S...UNTIL ONE GETS INTO NORTH DAKOTA BEHIND A SECONDARY COLD FRONT
WHERE READINGS ARE IN THE TEENS AND 20S. LAST ITEM OF NOTE IS THE
SEA LEVEL PRESSURE MAP WHERE A LOW EXISTS NEAR MEMPHIS ON THE NORTH
SIDE OF THE UPPER LOW THERE...ANOTHER LOW WAS OVER NORTHERN MN
AHEAD OF THE NORTH DAKOTA UPPER LOW...AND FINALLY A THIRD LOW WAS
OVER NORTHEAST OKLAHOMA AHEAD OF THE POTENT SHORTWAVES.
MODEL WISE...THERE ARE STILL SOME DIFFERENCES THAT HAVE SIGNIFICANT
FORECAST IMPLICATIONS. MUCH OF THE DIFFERENCES WE HAVE SEEN LATELY
THAT CONTINUE INTO TODAY REVOLVE AROUND HANDLING THOSE POTENT
SHORTWAVES IN SOUTHWEST OKLAHOMA AND NORTHERN NEW MEXICO. THE
STRONGER SURFACE LOW SCENARIOS THAT WOULD IMPACT THE FORECAST AREA
WITH MORE SNOW...LIKE OBSERVED IN THE 23.00Z NAM...BROUGHT THESE
SHORTWAVES INTO NORTHERN IL BY 12Z MONDAY. THOSE SHORTWAVE TRACKS
ALSO SHOWED IN A COUPLED UPPER JET STRUCTURE WITH ANOTHER JET STREAK
OVER ONTARIO AND LAKE SUPERIOR. HOWEVER...THE 23.12Z
NAM/GFS/CANADIAN/ECMWF SUGGEST THESE SHORTWAVES WILL TRACK THROUGH
CENTRAL IL. SO WHAT HAPPENS INSTEAD IS A DOUBLE SURFACE LOW...ONE
ASSOCIATED WITH THE NORTHERN MISSISSIPPI UPPER LOW LIFTING THROUGH
LOWER MI AND A SECOND LOW LIFTING TROUGH NORTHERN IL AT 12Z MONDAY.
WITH THE POTENT SHORTWAVES. THERE STILL ARE THE 2 JET STREAKS...BUT
THEY ARE FAR ENOUGH APART TO PREVENT COUPLING AND THUS PREVENTING A
SINGLE SURFACE LOW. THIS FORECAST LEANS TOWARDS THIS NEWER MODEL
GROUP. EVEN THIS GROUP HAS DIFFERENCES...PRIMARILY WITH THE CANADIAN
PRODUCING A LOT MORE SNOW ON MONDAY AROUND AND EAST OF THE
MISSISSIPPI RIVER.
FOR TONIGHT...THE WARM CONVEYOR BELT / FRONTOGENESIS BAND PRODUCING
THE ONGOING RAIN OVER THE SOUTHEAST HALF OF THE FORECAST AREA
REMAINS POISED TO SHIFT EASTWARD THROUGH THE EVENING. THIS EASTWARD
MOVEMENT IS DUE TO THE UPPER AND SURFACE LOWS NEAR THE MEMPHIS AREA
LIFTING INTO LOWER MICHIGAN. HOWEVER...DRIZZLE AND/OR LIGHT RAIN
SHOULD CONTINUE ELSEWHERE AS SOUNDINGS DEPICT PLENTIFUL LOW TO MID
LEVEL VERTICAL MOTION AND SATURATION...SIMILAR TO WHAT IS GOING ON
NOW. ADDITIONALLY...THAT WEAKENING BAND OF MID-LEVEL FRONTOGENESIS
SEEN ALONG I-35 IS POISED TO GRADUALLY CROSS THE FORECAST AREA WITH
THE SURFACE COLD FRONT...AIDING IN PRECIPITATION GENERATION. IT MAY
NOT BE UNTIL 09Z FOR THE FAR WESTERN FORECAST AREA TO SEE AN END TO
THE PRECIPITATION. NOTE THE TYPE SHOULD BEGIN TO CHANGE OVER TO SNOW
AS COLDER AIR IN THE DAKOTAS GETS PULLED INTO THE FORECAST AREA. ANY
ACCUMULATIONS TONIGHT SHOULD BE VERY LIGHT...DUE TO LATE CHANGE-OVER
TIME AND WARM GROUND...AND CONFINED TO MOSTLY WEST OF THE
MISSISSIPPI RIVER.
FOR MONDAY...ATTENTION FOCUSES ON THE LOW AND POTENT SHORTWAVES
LIFTING THROUGH ILLINOIS AT 12Z MONDAY. THERE IS A STRONG CONSENSUS
FOR PRECIPITATION IN THE WAKE OF THE LOW...CORRELATED WITH A LEFT
EXIT REGION OF A JET STREAK COMING INTO THE OHIO VALLEY.
ADDITIONALLY...A STRONG POCKET OF MID LEVEL FRONTOGENESIS WITH
NEGATIVE EPV ABOVE FOLLOWS IN THE WAKE OF THE LOW. THAT
FRONTOGENESIS STRENGTHENS AS THE COLD AIR FROM THE DAKOTAS MEETS UP
WITH THE POTENT SHORTWAVES LIFTING NORTHEASTWARD...ALSO CAUSING A
SWITCHOVER TO SNOW. CONSENSUS...OUTSIDE OF THE CANADIAN...SUGGESTS
THE HEAVIER SNOW TRACKING THROUGH NORTHERN IL AND SOUTHERN
WI...CLIPPING GRANT AND RICHLAND COUNTIES...POSSIBLY JUNEAU AND
ADAMS TOO. BOTH SNOWFALL AMOUNTS AND BLOWING POTENTIAL ARE GOING TO
BE KEPT DOWN QUITE A BIT WITH SOUNDINGS DEPICTING A DEEP AGGREGATION
LAYER AND ONLY 50 MB OR SO OF DENDRITIC GROWTH ZONE. ADDITIONALLY...
WARM GROUND AND LACK OF SNOW WILL HELP LIMIT BLOWING. IN
COLLABORATION WITH MKX AND DVN...HAVE ISSUED A WINTER WEATHER
ADVISORY FOR GRANT AND RICHLAND. ELSEWHERE...THERE SHOULD STILL BE
SOME LIGHTER SNOW WITH A WEAKER MID LEVEL FRONTOGENESIS ZONE
MARCHING WEST TO EAST...AND DEEP SATURATION. AMOUNTS DO NOT WARRANT
AN ADVISORY ELSEWHERE AT THIS TIME.
IN THE FOG DEPARTMENT...CONDITIONS HAVE YET TO IMPROVE ACROSS
TAYLOR/CLARK COUNTIES. HI RES MODEL VISIBILITY PROGS...WHICH
ARE HANDLING THE FOG THERE WELL...DO NOT SHOW ANY CLEARING UP UNTIL
THE 06-09Z PERIOD WHEN WINDS START TO INCREASE. THEREFORE...HAVE
EXTENDED THE ADVISORY UNTIL 06Z. VISIBILITIES HAVE ALSO BEEN LOW
OVER THE FAR WESTERN FORECAST AREA...THOUGH THESE SHOULD IMPROVE
SOON AS THE WINDS PICK UP. WILL NEED TO KEEP AN EYE ON VISIBILITIES
THROUGH NORTHEAST IOWA AND SOUTHWEST/CENTRAL WI AS THE HEAVIER RAIN
MOVES OUT...WITH SOME SIGNAL THEY COULD DROP TO WARRANT AN ADVISORY.
LASTLY...REGARDING WINDS...SHOULD SEE SUSTAINED SPEEDS OF 15-30 MPH
WITH GUSTS MAYBE UP TO 40 MPH ON MONDAY. DO NOT SEE ANY WIND
ADVISORY NEED AT THIS TIME...THOUGH. THESE NORTHWEST WINDS WILL
RESULT IN A FALLING TEMPERATURE TREND FROM NOW THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
NO MATTER WHAT SOLUTION PANS OUT FOR MONDAY...THE TREND CONTINUES TO
BE FOR SNOW TO DIMINISH MONDAY NIGHT AS THE ENTIRE STORM SYSTEM
EXITS EASTWARD INTO QUEBEC. THERE IS SOME UNCERTAINTY ON HOW QUICK
THE SNOW EXITS...MAINLY DUE TO ONE MORE WEAK SHORTWAVE PASSING. WITH
STRATUS LINGERING IN THE DENDRITIC GROWTH ZONE...IT MAKES SENSE TO
CONTINUE TO CARRY PRECIPITATION CHANCES LONGER TOO THAN WHAT MODEL
QPF WOULD SAY FOR ENDING SNOW. BETTER CHANCE FOR CLEARING COMES IN
TUESDAY AS A SURGE OF DRIER...SUBSIDENT AIR COMES IN AHEAD OF A
SURFACE LOW AND SHORTWAVE DROPPING THROUGH THE DAKOTAS. IN FACT...WE
SHOULD GET INTO A WARM ADVECTION REGIME LATER IN THE DAY TO ALLOW
TEMPERATURES TO CLIMB INTO THE MID TO UPPER 20S.
THE SHORTWAVE TROUGH AND SURFACE LOW DROPPING THROUGH THE DAKOTAS
FOR TUESDAY NIGHT AND WEDNESDAY HAS BEEN TRENDING SOUTHWARD IN THE
23.12Z ECMWF...FOLLOWING THE 23.06Z/12Z GFS/NAM. THE 23.12Z CANADIAN
IS ABOUT THE ONLY MODEL NOW WITH THE MORE NORTHERN TRACK. HAVE
ADJUSTED THE FORECAST FOR A MORE SOUTHERN TRACK. DPVA PLUS A SURGE
OF WARM AIR ADVECTION LOOKS TO RESULTS IN A BRIEF BUT HEAVY SNOW
BAND AHEAD OF THE SURFACE LOW. WITH THE SOUTHERN TREND BUT OVERALL
GOOD CONSENSUS TO HAVE THE SNOW BAND...RAISED CHANCES ON WEDNESDAY
TO 60 ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA. MAY GET A
QUICK 1-2 INCHES OUT OF THE BAND...ENOUGH TO IMPACT TRAVEL.
A DRIER BUT COLDER FORECAST IS ON TAP FOR WEDNESDAY NIGHT AND
THANKSGIVING AS ARCTIC HIGH PRESSURE BUILDS INTO THE REGION. 925MB
TEMPS DOWN TO -12 TO -16C SHOULD RESULT IN HIGHS IN THE TEENS TO
MAYBE 20 AT BEST.
THE FORECAST AFTER THANKSGIVING BECAME MUCH MORE UNCERTAIN
TODAY. THERE ARE NOW INDICATIONS OF MORE TROUGHING DIGGING DOWN
THROUGH BRITISH COLUMBIA...WHICH HELPS TO TURN THE UPPER FLOW MORE
ZONAL...AND THUS SEND A WARMER PACIFIC AIRMASS TOWARDS US.
ADDITIONALLY...A WARM FRONT LOOKS TO MOVE THROUGH THE AREA ON
FRIDAY...WHICH COULD PRODUCE A LITTLE SNOW. NOW...THE 23.12Z
GFS/CANADIAN DRIVE A SHORTWAVE THROUGH THE REGION FRIDAY NIGHT AND
ALLOWS ARCTIC AIR TO RETURN FOR THE WEEKEND. THE 23.12Z ECMWF ALLOWS
THIS SHORTWAVE TO STAY FARTHER NORTH...KEEPING THE AREA IN THE WARM
SECTOR. FOR NOW...HAVE STAYED WITH THE CONSENSUS PRIOR TO THE NEW
ECMWF ARRIVAL...BUT THE WEEKEND TEMPS ARE DEFINITELY SUBJECT TO
CHANGE GREATLY. GENERALLY THE WEEKEND LOOKS DRY...THOUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1100 PM CST SUN NOV 23 2014
EXPECTING RAIN TO CHANGE OVER TO SNOW BEFORE 08Z FOR KRST...AND
CLOSE TO 12Z FOR KLSE. CIGS WILL REMAIN SUB 1 KFT THROUGH THE
MORNING...WITH A GRADUAL...SMALL BUMP UP FOR THE AFTERNOON/EVENING.
MODELS SUGGESTING A POSSIBLE BRIEF BREAK IN PCPN/INTENSITY/COVERAGE
COULD OCCUR EARLY MORNING...WITH ANOTHER PIECE OF UPPER LEVEL
ENERGY/SFC TROUGH BRINGING ANOTHER ROUND OF LOW VSBY -SN FOR LATE
MORNING/AFTERNOON. IMPACTS WOULD BE FELT MORE AT KLSE. SHOULD SEE
VSBY IMPROVEMENT BY THE EVENING. ACCUMULATIONS UP TO 3 INCHES
POSSIBLE AT KLSE...LESSER AMOUNTS AT KRST.
STRONG AND GUSTY NORTHWEST WINDS WILL PERSIST THROUGH THE DAY AND
INTO THE EVENING HOURS OF MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ017-
029-032>034-041-042-053>055-061.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO 6 AM CST TUESDAY
FOR WIZ043-044.
MN...WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING UNTIL
MIDNIGHT CST TONIGHT FOR MNZ088-096.
IA...WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING UNTIL
MIDNIGHT CST TONIGHT FOR IAZ011-030.
&&
$$
UPDATE...DAS
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CST SUN NOV 23 2014
.UPDATED...
1100 PM CST SUN NOV 23 2014
DENSE FOG PERSISTING ACROSS NORTHERN WI...AND A GOOD PORTION OF
CENTRAL WI. CHECKING WITH AREA DISPATCHES...VISIBILITY REMAINS POOR
AND TRAVEL CONTINUES TO BE IMPACTED. HAVE OPTED TO EXPAND AND EXTEND
THE DENSE FOG ADVISORY THROUGH 3 AM...AND INCLUDED A CHUNK OF
CENTRAL WI. EXPECT IMPROVEMENT IN THE 2 TO 4 AM TIME FRAME AS A COLD
FRONT SWEEPS IN WITH STRONG NORTHWEST WINDS BEHIND IT.
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
COMPLEX SHORT TERM PERIOD WITH MANY ISSUES TO DEAL WITH.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A VERY ACTIVE PATTERN OVER THE WEST HALF OF THE COUNTRY.
UPPER LOWS WERE PRESENT OVER NORTHERN MISSISSIPPI AND NORTH
DAKOTA...WHILE POTENT SHORTWAVES WERE NOTED IN SOUTHWEST OKLAHOMA...
NORTHERN NEW MEXICO AND OVER WASHINGTON STATE. THE FORECAST AREA
LIES IN SOUTHWEST FLOW...WHERE WATER VAPOR IMAGERY SHOWS A NICE WARM
CONVEYOR BELT OVER THE EAST HALF OF THE AREA. THIS TRANSLATES TO A
BAND OF RAIN FROM EASTERN IA THROUGH SOUTHWEST WI TO THE GRB AREA.
RAP PRECIPITABLE WATER VALUES ARE AROUND 1 INCH ALONG AND SOUTH OF
THE BAND...COMPARED TO 0.75 INCHES OVER OUR NORTHWEST CWA WHERE
CONDITIONS ARE DRY. ALTHOUGH ITS DRIER IN PRECIPITABLE WATER...
DRIZZLE AND/OR LIGHT RAIN HAS BEEN PRESENT DUE TO SATURATED LOW
LEVELS AND WEAK ISENTROPIC LIFT ON THE 285-290K SURFACES. TO THE
WEST...A COLD FRONT WAS PRESENT ALONG I-35 WITH A WEAKENING BAND OF
RAIN RIGHT BEHIND IT...ASSOCIATED WITH MID LEVEL FRONTOGENESIS.
TEMPERATURES AHEAD OF THE FRONT ACROSS THE FORECAST AREA WERE MAINLY
IN THE 40S TO LOW 50S...COLDEST OVER THE DEEPER SNOWPACK IN TAYLOR
COUNTY. IN THE WAKE OF THE FRONT...READINGS WERE IN THE 30S AND
40S...UNTIL ONE GETS INTO NORTH DAKOTA BEHIND A SECONDARY COLD FRONT
WHERE READINGS ARE IN THE TEENS AND 20S. LAST ITEM OF NOTE IS THE
SEA LEVEL PRESSURE MAP WHERE A LOW EXISTS NEAR MEMPHIS ON THE NORTH
SIDE OF THE UPPER LOW THERE...ANOTHER LOW WAS OVER NORTHERN MN
AHEAD OF THE NORTH DAKOTA UPPER LOW...AND FINALLY A THIRD LOW WAS
OVER NORTHEAST OKLAHOMA AHEAD OF THE POTENT SHORTWAVES.
MODEL WISE...THERE ARE STILL SOME DIFFERENCES THAT HAVE SIGNIFICANT
FORECAST IMPLICATIONS. MUCH OF THE DIFFERENCES WE HAVE SEEN LATELY
THAT CONTINUE INTO TODAY REVOLVE AROUND HANDLING THOSE POTENT
SHORTWAVES IN SOUTHWEST OKLAHOMA AND NORTHERN NEW MEXICO. THE
STRONGER SURFACE LOW SCENARIOS THAT WOULD IMPACT THE FORECAST AREA
WITH MORE SNOW...LIKE OBSERVED IN THE 23.00Z NAM...BROUGHT THESE
SHORTWAVES INTO NORTHERN IL BY 12Z MONDAY. THOSE SHORTWAVE TRACKS
ALSO SHOWED IN A COUPLED UPPER JET STRUCTURE WITH ANOTHER JET STREAK
OVER ONTARIO AND LAKE SUPERIOR. HOWEVER...THE 23.12Z
NAM/GFS/CANADIAN/ECMWF SUGGEST THESE SHORTWAVES WILL TRACK THROUGH
CENTRAL IL. SO WHAT HAPPENS INSTEAD IS A DOUBLE SURFACE LOW...ONE
ASSOCIATED WITH THE NORTHERN MISSISSIPPI UPPER LOW LIFTING THROUGH
LOWER MI AND A SECOND LOW LIFTING TROUGH NORTHERN IL AT 12Z MONDAY.
WITH THE POTENT SHORTWAVES. THERE STILL ARE THE 2 JET STREAKS...BUT
THEY ARE FAR ENOUGH APART TO PREVENT COUPLING AND THUS PREVENTING A
SINGLE SURFACE LOW. THIS FORECAST LEANS TOWARDS THIS NEWER MODEL
GROUP. EVEN THIS GROUP HAS DIFFERENCES...PRIMARILY WITH THE CANADIAN
PRODUCING A LOT MORE SNOW ON MONDAY AROUND AND EAST OF THE
MISSISSIPPI RIVER.
FOR TONIGHT...THE WARM CONVEYOR BELT / FRONTOGENESIS BAND PRODUCING
THE ONGOING RAIN OVER THE SOUTHEAST HALF OF THE FORECAST AREA
REMAINS POISED TO SHIFT EASTWARD THROUGH THE EVENING. THIS EASTWARD
MOVEMENT IS DUE TO THE UPPER AND SURFACE LOWS NEAR THE MEMPHIS AREA
LIFTING INTO LOWER MICHIGAN. HOWEVER...DRIZZLE AND/OR LIGHT RAIN
SHOULD CONTINUE ELSEWHERE AS SOUNDINGS DEPICT PLENTIFUL LOW TO MID
LEVEL VERTICAL MOTION AND SATURATION...SIMILAR TO WHAT IS GOING ON
NOW. ADDITIONALLY...THAT WEAKENING BAND OF MID-LEVEL FRONTOGENESIS
SEEN ALONG I-35 IS POISED TO GRADUALLY CROSS THE FORECAST AREA WITH
THE SURFACE COLD FRONT...AIDING IN PRECIPITATION GENERATION. IT MAY
NOT BE UNTIL 09Z FOR THE FAR WESTERN FORECAST AREA TO SEE AN END TO
THE PRECIPITATION. NOTE THE TYPE SHOULD BEGIN TO CHANGE OVER TO SNOW
AS COLDER AIR IN THE DAKOTAS GETS PULLED INTO THE FORECAST AREA. ANY
ACCUMULATIONS TONIGHT SHOULD BE VERY LIGHT...DUE TO LATE CHANGE-OVER
TIME AND WARM GROUND...AND CONFINED TO MOSTLY WEST OF THE
MISSISSIPPI RIVER.
FOR MONDAY...ATTENTION FOCUSES ON THE LOW AND POTENT SHORTWAVES
LIFTING THROUGH ILLINOIS AT 12Z MONDAY. THERE IS A STRONG CONSENSUS
FOR PRECIPITATION IN THE WAKE OF THE LOW...CORRELATED WITH A LEFT
EXIT REGION OF A JET STREAK COMING INTO THE OHIO VALLEY.
ADDITIONALLY...A STRONG POCKET OF MID LEVEL FRONTOGENESIS WITH
NEGATIVE EPV ABOVE FOLLOWS IN THE WAKE OF THE LOW. THAT
FRONTOGENESIS STRENGTHENS AS THE COLD AIR FROM THE DAKOTAS MEETS UP
WITH THE POTENT SHORTWAVES LIFTING NORTHEASTWARD...ALSO CAUSING A
SWITCHOVER TO SNOW. CONSENSUS...OUTSIDE OF THE CANADIAN...SUGGESTS
THE HEAVIER SNOW TRACKING THROUGH NORTHERN IL AND SOUTHERN
WI...CLIPPING GRANT AND RICHLAND COUNTIES...POSSIBLY JUNEAU AND
ADAMS TOO. BOTH SNOWFALL AMOUNTS AND BLOWING POTENTIAL ARE GOING TO
BE KEPT DOWN QUITE A BIT WITH SOUNDINGS DEPICTING A DEEP AGGREGATION
LAYER AND ONLY 50 MB OR SO OF DENDRITIC GROWTH ZONE. ADDITIONALLY...
WARM GROUND AND LACK OF SNOW WILL HELP LIMIT BLOWING. IN
COLLABORATION WITH MKX AND DVN...HAVE ISSUED A WINTER WEATHER
ADVISORY FOR GRANT AND RICHLAND. ELSEWHERE...THERE SHOULD STILL BE
SOME LIGHTER SNOW WITH A WEAKER MID LEVEL FRONTOGENESIS ZONE
MARCHING WEST TO EAST...AND DEEP SATURATION. AMOUNTS DO NOT WARRANT
AN ADVISORY ELSEWHERE AT THIS TIME.
IN THE FOG DEPARTMENT...CONDITIONS HAVE YET TO IMPROVE ACROSS
TAYLOR/CLARK COUNTIES. HI RES MODEL VISIBILITY PROGS...WHICH
ARE HANDLING THE FOG THERE WELL...DO NOT SHOW ANY CLEARING UP UNTIL
THE 06-09Z PERIOD WHEN WINDS START TO INCREASE. THEREFORE...HAVE
EXTENDED THE ADVISORY UNTIL 06Z. VISIBILITIES HAVE ALSO BEEN LOW
OVER THE FAR WESTERN FORECAST AREA...THOUGH THESE SHOULD IMPROVE
SOON AS THE WINDS PICK UP. WILL NEED TO KEEP AN EYE ON VISIBILITIES
THROUGH NORTHEAST IOWA AND SOUTHWEST/CENTRAL WI AS THE HEAVIER RAIN
MOVES OUT...WITH SOME SIGNAL THEY COULD DROP TO WARRANT AN ADVISORY.
LASTLY...REGARDING WINDS...SHOULD SEE SUSTAINED SPEEDS OF 15-30 MPH
WITH GUSTS MAYBE UP TO 40 MPH ON MONDAY. DO NOT SEE ANY WIND
ADVISORY NEED AT THIS TIME...THOUGH. THESE NORTHWEST WINDS WILL
RESULT IN A FALLING TEMPERATURE TREND FROM NOW THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
NO MATTER WHAT SOLUTION PANS OUT FOR MONDAY...THE TREND CONTINUES TO
BE FOR SNOW TO DIMINISH MONDAY NIGHT AS THE ENTIRE STORM SYSTEM
EXITS EASTWARD INTO QUEBEC. THERE IS SOME UNCERTAINTY ON HOW QUICK
THE SNOW EXITS...MAINLY DUE TO ONE MORE WEAK SHORTWAVE PASSING. WITH
STRATUS LINGERING IN THE DENDRITIC GROWTH ZONE...IT MAKES SENSE TO
CONTINUE TO CARRY PRECIPITATION CHANCES LONGER TOO THAN WHAT MODEL
QPF WOULD SAY FOR ENDING SNOW. BETTER CHANCE FOR CLEARING COMES IN
TUESDAY AS A SURGE OF DRIER...SUBSIDENT AIR COMES IN AHEAD OF A
SURFACE LOW AND SHORTWAVE DROPPING THROUGH THE DAKOTAS. IN FACT...WE
SHOULD GET INTO A WARM ADVECTION REGIME LATER IN THE DAY TO ALLOW
TEMPERATURES TO CLIMB INTO THE MID TO UPPER 20S.
THE SHORTWAVE TROUGH AND SURFACE LOW DROPPING THROUGH THE DAKOTAS
FOR TUESDAY NIGHT AND WEDNESDAY HAS BEEN TRENDING SOUTHWARD IN THE
23.12Z ECMWF...FOLLOWING THE 23.06Z/12Z GFS/NAM. THE 23.12Z CANADIAN
IS ABOUT THE ONLY MODEL NOW WITH THE MORE NORTHERN TRACK. HAVE
ADJUSTED THE FORECAST FOR A MORE SOUTHERN TRACK. DPVA PLUS A SURGE
OF WARM AIR ADVECTION LOOKS TO RESULTS IN A BRIEF BUT HEAVY SNOW
BAND AHEAD OF THE SURFACE LOW. WITH THE SOUTHERN TREND BUT OVERALL
GOOD CONSENSUS TO HAVE THE SNOW BAND...RAISED CHANCES ON WEDNESDAY
TO 60 ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA. MAY GET A
QUICK 1-2 INCHES OUT OF THE BAND...ENOUGH TO IMPACT TRAVEL.
A DRIER BUT COLDER FORECAST IS ON TAP FOR WEDNESDAY NIGHT AND
THANKSGIVING AS ARCTIC HIGH PRESSURE BUILDS INTO THE REGION. 925MB
TEMPS DOWN TO -12 TO -16C SHOULD RESULT IN HIGHS IN THE TEENS TO
MAYBE 20 AT BEST.
THE FORECAST AFTER THANKSGIVING BECAME MUCH MORE UNCERTAIN
TODAY. THERE ARE NOW INDICATIONS OF MORE TROUGHING DIGGING DOWN
THROUGH BRITISH COLUMBIA...WHICH HELPS TO TURN THE UPPER FLOW MORE
ZONAL...AND THUS SEND A WARMER PACIFIC AIRMASS TOWARDS US.
ADDITIONALLY...A WARM FRONT LOOKS TO MOVE THROUGH THE AREA ON
FRIDAY...WHICH COULD PRODUCE A LITTLE SNOW. NOW...THE 23.12Z
GFS/CANADIAN DRIVE A SHORTWAVE THROUGH THE REGION FRIDAY NIGHT AND
ALLOWS ARCTIC AIR TO RETURN FOR THE WEEKEND. THE 23.12Z ECMWF ALLOWS
THIS SHORTWAVE TO STAY FARTHER NORTH...KEEPING THE AREA IN THE WARM
SECTOR. FOR NOW...HAVE STAYED WITH THE CONSENSUS PRIOR TO THE NEW
ECMWF ARRIVAL...BUT THE WEEKEND TEMPS ARE DEFINITELY SUBJECT TO
CHANGE GREATLY. GENERALLY THE WEEKEND LOOKS DRY...THOUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1100 PM CST SUN NOV 23 2014
EXPECTING RAIN TO CHANGE OVER TO SNOW BEFORE 08Z FOR KRST...AND
CLOSE TO 12Z FOR KLSE. CIGS WILL REMAIN SUB 1 KFT THROUGH THE
MORNING...WITH A GRADUAL...SMALL BUMP UP FOR THE AFTERNOON/EVENING.
MODELS SUGGESTING A POSSIBLE BRIEF BREAK IN PCPN/INTENSITY/COVERAGE
COULD OCCUR EARLY MORNING...WITH ANOTHER PIECE OF UPPER LEVEL
ENERGY/SFC TROUGH BRINGING ANOTHER ROUND OF LOW VSBY -SN FOR LATE
MORNING/AFTERNOON. IMPACTS WOULD BE FELT MORE AT KLSE. SHOULD SEE
VSBY IMPROVEMENT BY THE EVENING. ACCUMULATIONS UP TO 3 INCHES
POSSIBLE AT KLSE...LESSER AMOUNTS AT KRST.
STRONG AND GUSTY NORTHWEST WINDS WILL PERSIST THROUGH THE DAY AND
INTO THE EVENING HOURS OF MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 3 AM CST MONDAY FOR WIZ017-029-034-
042>044.
WINTER WEATHER ADVISORY FROM 6 AM MONDAY TO MIDNIGHT CST MONDAY
NIGHT FOR WIZ055-061.
MN...NONE.
IA...NONE.
&&
$$
UPDATED......RIECK
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
808 AM CST MON NOV 24 2014
.SHORT TERM...
313 AM CST
THROUGH TONIGHT...
COMPLEX STORM SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH
TONIGHT WITH A TRANSITION FROM MILD AND RAINY TOWARD COLD AND
POTENTIALLY SNOWY LIKELY TO TAKE PLACE LATER THIS MORNING.
DEEPENING SURFACE LOW FROM CENTRAL LAKE MICHIGAN EAST INTO LOWER
MICHIGAN WILL CONTINUE TO LIFT NORTHEAST TODAY AND DEEPEN FURTHER.
COLD FRONT TRAILING THIS BROAD LOW IS CROSSING THE MISSISSIPPI RIVER
NOW AND WILL STEADILY MARCH EAST ACROSS OUR CWA THIS MORNING
RESULTING IN STEADILY FALLING TEMPERATURES FROM THE POINT OF FROPA
THROUGH TONIGHT.
THE PRIMARY DEFORMATION ZONE WITH THIS SYSTEM IS MOVING OUT OF THE
AREA AT THIS TIME...HOWEVER THERE ARE A COUPLE ADDITIONAL VORTICITY
MAXIMA UPSTREAM. THE FIRST WELL DEFINED VORT IS NEAR STL WITH A SLUG
OF RAIN AND EVEN A COUPLE OF ISOLATED THUNDERSTORMS. THIS VORT IS
PROGGED TO SHEAR ENE CENTRAL ILLINOIS INTO NORTHERN OHIO TODAY. A
SECOND VORT MAX IS LOCATED UPSTREAM OVER KANSAS AND PIVOTING AROUND
THE BASE OF THE TROUGH AND EVENTUALLY PHASE WITH THE SHEARING OUT
VORT OVER INDIANA AND OHIO THIS AFTERNOON. AS THIS PROCESS TAKES
PLACE...THE RAIN ASSOCIATED WITH VORT ONE WILL SPREAD NORTHEAST
ACROSS OUR CWA THIS MORNING. AS THE SECOND VORT BEGINS TO PHASE WITH
THE FIRST A ZONE OF MID-LEVEL FRONTOGENESIS WILL DEVELOP ACROSS THE
LOWER LAKES THIS AFTERNOON AND ALLOW PRECIP WITH FIRST VORT TO
MAINTAIN ITSELF AND EVEN DEVELOP UPSTREAM (WESTWARD) INTO FAR
NORTHERN ILLINOIS AND ESPECIALLY INTO SOUTHERN WISCONSIN.
GUIDANCE HAS ALL SHIFTED NORTHWARD WITH THIS PROCESS COMPARED WITH
EARLIER RUNS AND ITS DIFFICULT TO FIND ANY MODEL THAT STILL SUPPORTS
THE 3-5" FORECAST TOTALS WE HAVE GOING IN THE ADVISORY AREA. AM VERY
LEARY ABOUT OVER CORRECTING THINGS SO DID A LOT OF FUZZY MATH AND
FUDGING OF GRIDS TO MAINTAIN AMOUNTS IN THE 2-5" RANGE IN THE
ADVISORY AREA...THOUGH SUSPECT MAJORITY OF THE ADVISORY AREA WILL
END UP WITH TOTALS ON THE BOTTOM END OF THE RANGE. SOUTH OF THE
ADVISORY AREA STILL THINK THERE COULD BE A CHANGEOVER TO SNOW BEFORE
THE DEFORMATION AXIS SHIFTS NORTHWARD AND PRECIP TAPER OFF THIS
AFTERNOON. IF CHANGE OVER ISNT FAST ENOUGH THEN COULD END UP WITH
JUST A TRACE OF SNOW...THOUGH FASTER CHANGE OVER AND BRIEF HEAVIER
INTENSITY COULD SUPPORT AMOUNTS AROUND AN INCH. BEFORE THE ENTIRE
CHANNELED VORT MAX TRANSLATES NORTHEAST OUT OF THE AREA COULD SEE
WESTERN EXTENT OF THE AXIS PIVOT BACK SOUTHWARD A BIT THIS AFTERNOON
INTO OUR NORTHWEST CWA...AND THIS WOULD BE NECESSARY TO GET FORECAST
AMOUNTS.
STRONG WESTERLY WINDS DEVELOP THIS MORNING BEHIND THE COLD FRONT AND
WILL CONTINUE INTO THIS EVENING. THE WINDS WILL WHIP AROUND ANY
FALLING SNOW LEADING TO GREATER REDUCTIONS IN VSBY. IN ADDITION...AS
TEMPS CONTINUE TO FALL FARTHER BELOW FREEZING LATER THIS AFTERNOON
SOME OF THE SNOW ON THE GROUND COULD GET BLOWN AROUND AS SNOW LIKELY
BECOMES MORE POWDERY IN NATURE.
IZZI
&&
.LONG TERM...
313 AM CST
TUESDAY ONWARD...
EXPANSIVE STRATUS DECK LIKELY TO BECOME ESTABLISHED OVER THE AREA
TUESDAY AND WHILE LOW LEVEL FLOW WILL BEGIN TO TRANSITION TO
ANTICYCLONIC TUESDAY AFTERNOON AHEAD OF THE NEXT CLIPPER...NOT SURE
HOW MUCH CLEARING THERE WILL BE AS DRY AIR ADVECTION WILL BE WEAK
WITH DIMINISHING FLOW. IN ADDITION...SUBSIDENCE WILL FURTHER SHARPEN
THE INVERSION CLOUDS ARE TRAPPED BENEATH SO HAVE INCREASED SKY COVER
TUESDAY AND NO LONGER SHOW ANY SUBSTANTIAL CLEARING BEFORE THE MID
WEEK CLIPPER COMES ZIPPING DOWN. GIVEN THE ANTICIPATED CLOUD COVER
HAVE GONE WITH SMALLER DIURNAL TEMP SWINGS WITH CLOUDS PROBABLY
KEEPING TEMPS UP A SMIDGE OVER GUIDANCE AT NIGHT AND A BIT LOWER
DURING THE DAY.
SPEAKING OF THE MID WEEK CLIPPER...GUIDANCE REMAINS INCONSISTENT RUN
TO RUN AND MODEL TO MODEL. THERE HAS BEEN A DISTINCT SOUTHWARD SHIFT
IN GUIDANCE WITH THIS SYSTEM WHICH IF IT WERE TO PAN OUT WOULD PLACE
THE ACCUMULATING SNOW OVER MAINLY OUR SOUTHERN CWA AND POTENTIALLY
BYPASS NORTHERN CWA. THIS CLIPPER IS ORIGINATING AS A PIECE OF
ENERGY BREAKING OFF AN UPPER LOW NEAR THE NORTHERN ALEUTIANS AND
SEEING AS IT HADNT EVEN BROKEN OFF THE LOW AND BEEN WELL SAMPLED YET
AM NOT READY TO THROW MY EGGS IN THE MORE SOUTHERLY TRACK BASKET
JUST YET. BY 12Z WEDNESDAY THE GFS ENSEMBLES HAVE SURFACE LOW
POSITIONS RANGING FROM WESTERN WISCONSIN TO NORTHWEST ARKANSAS...SO
NEEDLESS TO SAY FURTHER CHANGES ARE LIKELY THE NEXT SEVERAL GUIDANCE
CYCLES WITH THIS SYSTEM AND IT IS TOO SOON TO WRITE OFF THE THREAT
OF LIGHT ACCUMULATING SNOW ANYWHERE IN OUR CWA.
ANOTHER INTERESTING TWIST IN THE LATEST MEDIUM RANGE GUIDANCE IS
LESS OF A COLD INTRUSION IN THE WAKE OF THIS CLIPPER FOLLOWED BY A
RAPID TRANSITION TO ZONAL FLOW BY FRIDAY AND INTO THE WEEKEND.
GFS...GEM...AND ECMWF ALL TRACK A SFC LOW OF VARYING STRENGTHS
ACROSS THE UPPER GREAT LAKES SATURDAY PLACING OUR AREA IN WHAT WOULD
BE A VERY MILD SOUTHERLY FLOW. THE 00Z ECMWF THERMAL FIELDS WOULD
SUPPORT HIGHS WELL INTO THE 50S BY SATURDAY...BUT OBVIOUSLY DIDN`T
MAKE THAT DRASTIC OF A CHANGE TO THE GOING FORECAST BUT IF MODELS
REMAIN CONSISTENT WITH THIS LATEST TREND THEN A MILD WEEKEND COULD
BE ON TAP FOR THE REGION.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* IFR CIGS PERSIST THROUGH THE COMING HOURS AND MAY LOWER TO 500 FT
AT TIMES.
* STEADIER RAIN RETURNING JUST AFTER DAYBREAK.
* SOUTHWEST WINDS TO 10 KT SHIFT WEST THIS MORNING THEN SOUTHWEST
WITH GUSTS TO 30 KT WITH A PERIOD OF 35 KT GUSTS POSSIBLE
MIDDAY/EARLY AFTERNOON.
* RAIN CHANGES TO SNOW LATE MORNING..SOME LIGHT ACCUMULATION
POSSIBLE...ESPECIALLY AROUND MIDDAY. LIGHTER -SHSN CONTINUE INTO
THE EVENING WITH SOME ADDITIONAL LIGHT ACCUMULATIONS.
* IFR CIGS LIFTING TO MVFR THIS AFTERNOON.
KMD/BEACHLER
//DISCUSSION...UPDATED 12Z...
THE NEXT BATCH OF PRECIPIATION IS FORECAST TO MOVE TSHORTLY WITH INITIAL
PRECIPITATION TYPE AS -RA. EXPECT CIGS TO REMAIN IFR BUT PROBABLY
LIFT SOME AS WEST WINDS BEGIN TO PICK UP WITH LOW PRESSURE MOVING
NORTHEASTWARD WITH -RASN MIX AROUND 15Z AT KRFD AND A FEW HOURS
LATER IN THE CHICAGO AREA...TURNING TO ALL -SN AROUND 18Z OR SO. THE
COLD AIR IS MAKING A GOOD RUN AT THE AREA SO SPED UP THE TIMING TO
TRANSITION TO -SN. MOISTURE WIL BE DECREASING FROM SOUTH TO NORTH
AS THE TRANSITION FROM -RA TO -SN OCCURS...SO SOME UNCERTAINTY AS
TO HOW LONG THE MODERATE SNOW WILL LAST THE HIGHEST LIKELIHOOD
FOR ACCUMS IS WEST AND NORTH OF THE MAIN CHICAGO TERMINALS TOWARD
ROCKFORD...BUT SOME ACCUMS ARE CERTAINLY STILL PLAUSIBLE
EVERYWHERE..ESPECIALLY IN THE 17Z-20Z TIME FRAME BEFORE THE MAIN
BATCH OF PRECIPITATION SHIFTS NORTHWARD. EXPECT IFR IN THE FIRST
SHOT OF SNOW THEN A TRANSITION TO MVFR WITH LIGHTER SNOW THROUGH
THE AFTERNOON. DURING THIS SAME TIME WINDS WILL BE RAMPING UP WITH
GUSTS TO 30 KT LIKELY...AND POSSIBLY GUSTS TO 35 KT FOR A TIME.
AFTERWARDS...WINDS SLOWLY SUBSIDE...AND THEN A FEW SNOW SHOWERS BUT
MOST LIKELY POSSIBLY JUST FLURRIES OVERNIGHT OR EVEN DRY CONDITIONS
WITH MVFR AND BREEZY WEST WINDS.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH IN IFR CONTINUING WITH SOME LOWERING IN MODERATE RAIN THIS
MORNING.
* MEDIUM-HIGH CONFIDENCE IN VSBY HOLDING AT MVFR THOUGH OCCASIONAL
IFR MIXED IN. MVFR/IFR IN FIRST BATCH OF SNOW.
* HIGH CONFIDENCE IN WIND FORECAST MONDAY AND 30+ KT GUSTS. MEDIUM
CONFIDENCE IN SPORADICALLY REACHING 35 KT OR SO.
* HIGH CONFIDENCE IN RAIN CHANGING TO SNOW BUT LOW CONFIDENCE IN
HOW MUCH PRECIP COVERAGE THERE WILL BE THROUGH THE
AFTERNOON/EVENING.
* HIGH CONFIDENCE ON CIG TRENDS...LOW-MEDIUM ON WHEN IFR LIFTS TO
MVFR AND HOW LONG MVFR LASTS.
KMD/BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...SCHC SNOW. OTHERWISE VFR. SOUTHEAST TO EAST WINDS.
THURSDAY...A FEW FLURRIES POSSIBLE...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST-SOUTHWEST WINDS.
SUNDAY...VFR. NORTH WINDS.
KMD
&&
.MARINE...
154 AM CST
DEEPENING LOW PRESSURE IS PASSING OVER THE LAKE EARLY THIS MORNING
BRINGING A LULL IN WINDS AND WAVES. THE LOW WILL CONTINUE NORTHEAST
INTO SOUTHWEST QUEBEC LATER THIS AFTERNOON THEN REMAIN STEADY AS IT
PUSHES OFFSHORE OVER NOVA SCOTIA. A STRONG SOUTHWEST TO NORTHEAST
ORIENTED PRESSURE GRADIENT WILL REACH THE SOUTH TIP OF THE LAKE BY
15Z...THEN SPREAD OVER THE REMAINDER OF THE LAKE IN THE AFTERNOON.
GALES LOOK SOLID FOR THE SOUTH HALF OF THE THE LAKE...BUT DUE TO A
WEAKENING PRESSURE GRADIENT WITH TIME TODAY AND A MODEST HIGH
BUILDING INTO THE CANADIAN PRARIES AND UPPER MIDWEST...FEEL THAT
WINDS WILL LIKELY PEAK JUST UNDER GALES FOR THE NORTH HALF. A FEW
GALE FORCE GUSTS ARE POSSIBLE...ESPECIALLY LATE AFTERNOON/EARLY
EVENING.
WEAK HIGH PRESSSURE EXTENDING FROM THE NORTH TIP OF LAKE SUPERIOR TO
THE OHIO VALLEY PASSES OVER THE LAKE TUESDAY AFTERNOON. ANOTHER
WEAKENING LOW EMERGING FROM THE CANADIAN ROCKIES WILL PASS JUST
SOUTH OF THE TIP OF LAKE MICHIGAN WITH THE REMNANT INVERTED TROUGH
CLEARING THE LAKE BY THURSDAY MORNING. THIS WILL BE FOLLOWED BY WEAK
HIGH PRESSSURE FOR A FEW DAYS.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012 UNTIL MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM TUESDAY.
&&
$$
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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WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
543 AM CST Mon Nov 24 2014
.SHORT TERM...(Today)
ISSUED AT 329 AM CST MON NOV 24 2014
Several short-term forecast challenges today, as a potent storm
system tracks through the area. Of particular concern are
strong/gusty winds behind a departing frontal boundary and the
potential for a light accumulation of snow across the W/NW KILX
CWA.
08z/2am surface analysis shows cold front extending from southern
Lake Michigan to the Ozarks. An area of low pressure along the
boundary over southeast Missouri is currently enhancing lift and
triggering a few thunderstorms along/south of the I-70 corridor.
This activity will push E/NE into Indiana by dawn. Further west, an
area of precipitation along/behind the front will continue to lift
northward, mainly impacting locations along/west of I-57. As colder
air streams into the region, the rain will gradually mix with and
change to snow by mid-morning. Based on upstream temp falls across
Iowa/Missouri, readings will drop into the middle 30s across the
Illinois River Valley by 12z/6am, then further east to the I-55
corridor by 15z/9am. At the same time, the precip will be pulling
northeastward out of the area, so there appears to be only a narrow
window of opportunity for snow across the W/NW. Will carry likely
to categorical PoPs across the western half of the CWA for rain
changing to snow this morning, with lower rain chances further east
and south across the remainder of the region. Main area of snow
will lift into northern Illinois by midday, with only a few
flurries/snow-showers persisting along/north of I-72 this
afternoon. Total snow accumulation will be limited due to light QPF
and marginally favorable temps. Around 1 inch is expected
along/north of a Canton to Bloomington-Normal line, with trace
amounts as far southeast as a Litchfield to Champaign-Urbana
line.
Other big story today will be the strong winds behind the cold
front. Upstream obs have already shown gusts as high as 30-40mph
and think these will translate eastward across central Illinois this
morning. Main question will be whether there may be a corridor of
enhanced winds approaching Wind Advisory criteria across the E/SE
CWA. Current MSAS analysis shows max 3-hour pressure rises of 6mb
over southern Missouri/northern Arkansas. Both the 00z and 06z runs
of the NAM have shown these rises tracking northeastward and
increasing to around 9mb over southeast Illinois later this
morning. HRRR 10m wind gust graphic also indicates increasing winds
ahead of the pressure change couplet as it moves across the
southeast CWA between 12z and 18z. Given this consistent signal,
think it is prudent to issue a Wind Advisory for locations
along/southeast of a Champaign to Taylorville line. While all of
central Illinois will experience wind gusts of 30 to 35 mph, this
particular area may see higher gusts exceeding 40 mph.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 329 AM CST MON NOV 24 2014
Low pressure will lift into the Great Lakes tonight, taking the bulk
of the precip with it. Wrap around moisture may brush across the
northern CWA, so have included scattered flurries in the forecast
this evening along/north of I-72. Forecast soundings indicate low
clouds will persist tonight and may even be slow to clear on
Tuesday, despite approaching surface ridge axis. Have therefore
slowed the clearing trend, with cloudy skies tonight followed by
decreasing clouds on Tuesday.
Fast-moving clipper system is still on target for mid-week, with
model consensus bringing the system across central Illinois on
Wednesday. This particular track is slightly further south than
previously advertised, so WAA ahead of the wave may not be quite as
pronounced as once thought. Even still, high temperatures will
climb well into the 30s and into the lower 40s across the southeast
CWA. End result will be light snow across the far north from the
Peoria area northward, a mix of light rain/snow across much of the
area, and mainly rain south of I-70. Due to the limited period of
light precip and warm temps, snow accumulations will be minimal.
Once this system passes to the east, another shot of cold air will
arrive for Thursday. After that, signs are still pointing to warmer
conditions by the end of the week, with temps climbing well into the
40s by Saturday. Both the GFS and ECMWF indicate a cold front will
drop through the region Saturday night, so temps will likely drop
back into the upper 30s/lower 40s by Sunday/Monday. Moisture will
be limited, so will maintain a dry FROPA at this time.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 534 AM CST MON NOV 24 2014
A strong cold front has surged across the central Illinois
terminals within the past few hours. Strong westerly winds, with
gusts approaching 35-40 kts at times, will linger through the day
before diminishing this evening. The lingering precipitation
wrapping in behind the front will quickly change over to snow this
morning before ending around midday. IFR or low end MVFR conditions
to start the period will climb into or further into the MVFR
category as the snow comes to an end. While it is possible cigs
may improve to VFR tonight, the better odds are that they will
remain in the MVFR category.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 6 PM CST this evening FOR ILZ044>046-052>057-
061>063-066>068-071>073.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Bak
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
542 AM CST MON NOV 24 2014
.SHORT TERM...
313 AM CST
THROUGH TONIGHT...
COMPLEX STORM SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH
TONIGHT WITH A TRANSITION FROM MILD AND RAINY TOWARD COLD AND
POTENTIALLY SNOWY LIKELY TO TAKE PLACE LATER THIS MORNING.
DEEPENING SURFACE LOW FROM CENTRAL LAKE MICHIGAN EAST INTO LOWER
MICHIGAN WILL CONTINUE TO LIFT NORTHEAST TODAY AND DEEPEN FURTHER.
COLD FRONT TRAILING THIS BROAD LOW IS CROSSING THE MISSISSIPPI RIVER
NOW AND WILL STEADILY MARCH EAST ACROSS OUR CWA THIS MORNING
RESULTING IN STEADILY FALLING TEMPERATURES FROM THE POINT OF FROPA
THROUGH TONIGHT.
THE PRIMARY DEFORMATION ZONE WITH THIS SYSTEM IS MOVING OUT OF THE
AREA AT THIS TIME...HOWEVER THERE ARE A COUPLE ADDITIONAL VORTICITY
MAXIMA UPSTREAM. THE FIRST WELL DEFINED VORT IS NEAR STL WITH A SLUG
OF RAIN AND EVEN A COUPLE OF ISOLATED THUNDERSTORMS. THIS VORT IS
PROGGED TO SHEAR ENE CENTRAL ILLINOIS INTO NORTHERN OHIO TODAY. A
SECOND VORT MAX IS LOCATED UPSTREAM OVER KANSAS AND PIVOTING AROUND
THE BASE OF THE TROUGH AND EVENTUALLY PHASE WITH THE SHEARING OUT
VORT OVER INDIANA AND OHIO THIS AFTERNOON. AS THIS PROCESS TAKES
PLACE...THE RAIN ASSOCIATED WITH VORT ONE WILL SPREAD NORTHEAST
ACROSS OUR CWA THIS MORNING. AS THE SECOND VORT BEGINS TO PHASE WITH
THE FIRST A ZONE OF MID-LEVEL FRONTOGENESIS WILL DEVELOP ACROSS THE
LOWER LAKES THIS AFTERNOON AND ALLOW PRECIP WITH FIRST VORT TO
MAINTAIN ITSELF AND EVEN DEVELOP UPSTREAM (WESTWARD) INTO FAR
NORTHERN ILLINOIS AND ESPECIALLY INTO SOUTHERN WISCONSIN.
GUIDANCE HAS ALL SHIFTED NORTHWARD WITH THIS PROCESS COMPARED WITH
EARLIER RUNS AND ITS DIFFICULT TO FIND ANY MODEL THAT STILL SUPPORTS
THE 3-5" FORECAST TOTALS WE HAVE GOING IN THE ADVISORY AREA. AM VERY
LEARY ABOUT OVER CORRECTING THINGS SO DID A LOT OF FUZZY MATH AND
FUDGING OF GRIDS TO MAINTAIN AMOUNTS IN THE 2-5" RANGE IN THE
ADVISORY AREA...THOUGH SUSPECT MAJORITY OF THE ADVISORY AREA WILL
END UP WITH TOTALS ON THE BOTTOM END OF THE RANGE. SOUTH OF THE
ADVISORY AREA STILL THINK THERE COULD BE A CHANGEOVER TO SNOW BEFORE
THE DEFORMATION AXIS SHIFTS NORTHWARD AND PRECIP TAPER OFF THIS
AFTERNOON. IF CHANGE OVER ISNT FAST ENOUGH THEN COULD END UP WITH
JUST A TRACE OF SNOW...THOUGH FASTER CHANGE OVER AND BRIEF HEAVIER
INTENSITY COULD SUPPORT AMOUNTS AROUND AN INCH. BEFORE THE ENTIRE
CHANNELED VORT MAX TRANSLATES NORTHEAST OUT OF THE AREA COULD SEE
WESTERN EXTENT OF THE AXIS PIVOT BACK SOUTHWARD A BIT THIS AFTERNOON
INTO OUR NORTHWEST CWA...AND THIS WOULD BE NECESSARY TO GET FORECAST
AMOUNTS.
STRONG WESTERLY WINDS DEVELOP THIS MORNING BEHIND THE COLD FRONT AND
WILL CONTINUE INTO THIS EVENING. THE WINDS WILL WHIP AROUND ANY
FALLING SNOW LEADING TO GREATER REDUCTIONS IN VSBY. IN ADDITION...AS
TEMPS CONTINUE TO FALL FARTHER BELOW FREEZING LATER THIS AFTERNOON
SOME OF THE SNOW ON THE GROUND COULD GET BLOWN AROUND AS SNOW LIKELY
BECOMES MORE POWDERY IN NATURE.
IZZI
&&
.LONG TERM...
313 AM CST
TUESDAY ONWARD...
EXPANSIVE STRATUS DECK LIKELY TO BECOME ESTABLISHED OVER THE AREA
TUESDAY AND WHILE LOW LEVEL FLOW WILL BEGIN TO TRANSITION TO
ANTICYCLONIC TUESDAY AFTERNOON AHEAD OF THE NEXT CLIPPER...NOT SURE
HOW MUCH CLEARING THERE WILL BE AS DRY AIR ADVECTION WILL BE WEAK
WITH DIMINISHING FLOW. IN ADDITION...SUBSIDENCE WILL FURTHER SHARPEN
THE INVERSION CLOUDS ARE TRAPPED BENEATH SO HAVE INCREASED SKY COVER
TUESDAY AND NO LONGER SHOW ANY SUBSTANTIAL CLEARING BEFORE THE MID
WEEK CLIPPER COMES ZIPPING DOWN. GIVEN THE ANTICIPATED CLOUD COVER
HAVE GONE WITH SMALLER DIURNAL TEMP SWINGS WITH CLOUDS PROBABLY
KEEPING TEMPS UP A SMIDGE OVER GUIDANCE AT NIGHT AND A BIT LOWER
DURING THE DAY.
SPEAKING OF THE MID WEEK CLIPPER...GUIDANCE REMAINS INCONSISTENT RUN
TO RUN AND MODEL TO MODEL. THERE HAS BEEN A DISTINCT SOUTHWARD SHIFT
IN GUIDANCE WITH THIS SYSTEM WHICH IF IT WERE TO PAN OUT WOULD PLACE
THE ACCUMULATING SNOW OVER MAINLY OUR SOUTHERN CWA AND POTENTIALLY
BYPASS NORTHERN CWA. THIS CLIPPER IS ORIGINATING AS A PIECE OF
ENERGY BREAKING OFF AN UPPER LOW NEAR THE NORTHERN ALEUTIANS AND
SEEING AS IT HADNT EVEN BROKEN OFF THE LOW AND BEEN WELL SAMPLED YET
AM NOT READY TO THROW MY EGGS IN THE MORE SOUTHERLY TRACK BASKET
JUST YET. BY 12Z WEDNESDAY THE GFS ENSEMBLES HAVE SURFACE LOW
POSITIONS RANGING FROM WESTERN WISCONSIN TO NORTHWEST ARKANSAS...SO
NEEDLESS TO SAY FURTHER CHANGES ARE LIKELY THE NEXT SEVERAL GUIDANCE
CYCLES WITH THIS SYSTEM AND IT IS TOO SOON TO WRITE OFF THE THREAT
OF LIGHT ACCUMULATING SNOW ANYWHERE IN OUR CWA.
ANOTHER INTERESTING TWIST IN THE LATEST MEDIUM RANGE GUIDANCE IS
LESS OF A COLD INTRUSION IN THE WAKE OF THIS CLIPPER FOLLOWED BY A
RAPID TRANSITION TO ZONAL FLOW BY FRIDAY AND INTO THE WEEKEND.
GFS...GEM...AND ECMWF ALL TRACK A SFC LOW OF VARYING STRENGTHS
ACROSS THE UPPER GREAT LAKES SATURDAY PLACING OUR AREA IN WHAT WOULD
BE A VERY MILD SOUTHERLY FLOW. THE 00Z ECMWF THERMAL FIELDS WOULD
SUPPORT HIGHS WELL INTO THE 50S BY SATURDAY...BUT OBVIOUSLY DIDN`T
MAKE THAT DRASTIC OF A CHANGE TO THE GOING FORECAST BUT IF MODELS
REMAIN CONSISTENT WITH THIS LATEST TREND THEN A MILD WEEKEND COULD
BE ON TAP FOR THE REGION.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* IFR CIGS PERSIST THROUGH THE COMING HOURS AND MAY LOWER TO 500 FT
AT TIMES.
* STEADIER RAIN RETURNING JUST AFTER DAYBREAK.
* SOUTHWEST WINDS TO 10 KT SHIFT WEST THIS MORNING THEN SOUTHWEST
WITH GUSTS TO 30 KT WITH A PERIOD OF 35 KT GUSTS POSSIBLE
MIDDAY/EARLY AFTERNOON.
* RAIN CHANGES TO SNOW LATE MORNING..SOME LIGHT ACCUMULATION
POSSIBLE...ESPECIALLY AROUND MIDDAY. LIGHTER -SHSN CONTINUE INTO
THE EVENING WITH SOME ADDITIONAL LIGHT ACCUMULATIONS.
* IFR CIGS LIFTING TO MVFR THIS AFTERNOON.
KMD
//DISCUSSION...UPDATED 12Z...
THE NEXT BATCH OF PRECIPIATION IS FORECAST TO MOVE TSHORTLY WITH INITIAL
PRECIPITATION TYPE AS -RA. EXPECT CIGS TO REMAIN IFR BUT PROBABLY
LIFT SOME AS WEST WINDS BEGIN TO PICK UP WITH LOW PRESSURE MOVING
NORTHEASTWARD WITH -RASN MIX AROUND 15Z AT KRFD AND A FEW HOURS
LATER IN THE CHICAGO AREA...TURNING TO ALL -SN AROUND 18Z OR SO. THE
COLD AIR IS MAKING A GOOD RUN AT THE AREA SO SPED UP THE TIMING TO
TRANSITION TO -SN. MOISTURE WIL BE DECREASING FROM SOUTH TO NORTH
AS THE TRANSITION FROM -RA TO -SN OCCURS...SO SOME UNCERTAINTY AS
TO HOW LONG THE MODERATE SNOW WILL LAST THE HIGHEST LIKELIHOOD
FOR ACCUMS IS WEST AND NORTH OF THE MAIN CHICAGO TERMINALS TOWARD
ROCKFORD...BUT SOME ACCUMS ARE CERTAINLY STILL PLAUSIBLE
EVERYWHERE..ESPECIALLY IN THE 17Z-20Z TIME FRAME BEFORE THE MAIN
BATCH OF PRECIPITATION SHIFTS NORTHWARD. EXPECT IFR IN THE FIRST
SHOT OF SNOW THEN A TRANSITION TO MVFR WITH LIGHTER SNOW THROUGH
THE AFTERNOON. DURING THIS SAME TIME WINDS WILL BE RAMPING UP WITH
GUSTS TO 30 KT LIKELY...AND POSSIBLY GUSTS TO 35 KT FOR A TIME.
AFTERWARDS...WINDS SLOWLY SUBSIDE...AND THEN A FEW SNOW SHOWERS BUT
MOST LIKELY POSSIBLY JUST FLURRIES OVERNIGHT OR EVEN DRY CONDITIONS
WITH MVFR AND BREEZY WEST WINDS.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH IN IFR CONTINUING WITH SOME LOWERING IN MODERATE RAIN THIS
MORNING.
* MEDIUM-HIGH CONFIDENCE IN VSBY HOLDING AT MVFR THOUGH OCCASIONAL
IFR MIXED IN. MVFR/IFR IN FIRST BATCH OF SNOW.
* HIGH CONFIDENCE IN WIND FORECAST MONDAY AND 30+ KT GUSTS. MEDIUM
CONFIDENCE IN SPORADICALLY REACHING 35 KT OR SO.
* HIGH CONFIDENCE IN RAIN CHANGING TO SNOW BUT LOW CONFIDENCE IN
HOW MUCH PRECIP COVERAGE THERE WILL BE THROUGH THE
AFTERNOON/EVENING.
* HIGH CONFIDENCE ON CIG TRENDS...LOW-MEDIUM ON WHEN IFR LIFTS TO
MVFR AND HOW LONG MVFR LASTS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...SCHC SNOW. OTHERWISE VFR. SOUTHEAST TO EAST WINDS.
THURSDAY...A FEW FLURRIES POSSIBLE...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST-SOUTHWEST WINDS.
SUNDAY...VFR. NORTH WINDS.
KMD
&&
.MARINE...
154 AM CST
DEEPENING LOW PRESSURE IS PASSING OVER THE LAKE EARLY THIS MORNING
BRINGING A LULL IN WINDS AND WAVES. THE LOW WILL CONTINUE NORTHEAST
INTO SOUTHWEST QUEBEC LATER THIS AFTERNOON THEN REMAIN STEADY AS IT
PUSHES OFFSHORE OVER NOVA SCOTIA. A STRONG SOUTHWEST TO NORTHEAST
ORIENTED PRESSURE GRADIENT WILL REACH THE SOUTH TIP OF THE LAKE BY
15Z...THEN SPREAD OVER THE REMAINDER OF THE LAKE IN THE AFTERNOON.
GALES LOOK SOLID FOR THE SOUTH HALF OF THE THE LAKE...BUT DUE TO A
WEAKENING PRESSURE GRADIENT WITH TIME TODAY AND A MODEST HIGH
BUILDING INTO THE CANADIAN PRARIES AND UPPER MIDWEST...FEEL THAT
WINDS WILL LIKELY PEAK JUST UNDER GALES FOR THE NORTH HALF. A FEW
GALE FORCE GUSTS ARE POSSIBLE...ESPECIALLY LATE AFTERNOON/EARLY
EVENING.
WEAK HIGH PRESSSURE EXTENDING FROM THE NORTH TIP OF LAKE SUPERIOR TO
THE OHIO VALLEY PASSES OVER THE LAKE TUESDAY AFTERNOON. ANOTHER
WEAKENING LOW EMERGING FROM THE CANADIAN ROCKIES WILL PASS JUST
SOUTH OF THE TIP OF LAKE MICHIGAN WITH THE REMNANT INVERTED TROUGH
CLEARING THE LAKE BY THURSDAY MORNING. THIS WILL BE FOLLOWED BY WEAK
HIGH PRESSSURE FOR A FEW DAYS.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012...9 AM MONDAY TO MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 AM MONDAY TO 3 AM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
329 AM CST Mon Nov 24 2014
.SHORT TERM...(Today)
ISSUED AT 329 AM CST MON NOV 24 2014
Several short-term forecast challenges today, as a potent storm
system tracks through the area. Of particular concern are
strong/gusty winds behind a departing frontal boundary and the
potential for a light accumulation of snow across the W/NW KILX
CWA.
08z/2am surface analysis shows cold front extending from southern
Lake Michigan to the Ozarks. An area of low pressure along the
boundary over southeast Missouri is currently enhancing lift and
triggering a few thunderstorms along/south of the I-70 corridor.
This activity will push E/NE into Indiana by dawn. Further west, an
area of precipitation along/behind the front will continue to lift
northward, mainly impacting locations along/west of I-57. As colder
air streams into the region, the rain will gradually mix with and
change to snow by mid-morning. Based on upstream temp falls across
Iowa/Missouri, readings will drop into the middle 30s across the
Illinois River Valley by 12z/6am, then further east to the I-55
corridor by 15z/9am. At the same time, the precip will be pulling
northeastward out of the area, so there appears to be only a narrow
window of opportunity for snow across the W/NW. Will carry likely
to categorical PoPs across the western half of the CWA for rain
changing to snow this morning, with lower rain chances further east
and south across the remainder of the region. Main area of snow
will lift into northern Illinois by midday, with only a few
flurries/snow-showers persisting along/north of I-72 this
afternoon. Total snow accumulation will be limited due to light QPF
and marginally favorable temps. Around 1 inch is expected
along/north of a Canton to Bloomington-Normal line, with trace
amounts as far southeast as a Litchfield to Champaign-Urbana
line.
Other big story today will be the strong winds behind the cold
front. Upstream obs have already shown gusts as high as 30-40mph
and think these will translate eastward across central Illinois this
morning. Main question will be whether there may be a corridor of
enhanced winds approaching Wind Advisory criteria across the E/SE
CWA. Current MSAS analysis shows max 3-hour pressure rises of 6mb
over southern Missouri/northern Arkansas. Both the 00z and 06z runs
of the NAM have shown these rises tracking northeastward and
increasing to around 9mb over southeast Illinois later this
morning. HRRR 10m wind gust graphic also indicates increasing winds
ahead of the pressure change couplet as it moves across the
southeast CWA between 12z and 18z. Given this consistent signal,
think it is prudent to issue a Wind Advisory for locations
along/southeast of a Champaign to Taylorville line. While all of
central Illinois will experience wind gusts of 30 to 35 mph, this
particular area may see higher gusts exceeding 40 mph.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 329 AM CST MON NOV 24 2014
Low pressure will lift into the Great Lakes tonight, taking the bulk
of the precip with it. Wrap around moisture may brush across the
northern CWA, so have included scattered flurries in the forecast
this evening along/north of I-72. Forecast soundings indicate low
clouds will persist tonight and may even be slow to clear on
Tuesday, despite approaching surface ridge axis. Have therefore
slowed the clearing trend, with cloudy skies tonight followed by
decreasing clouds on Tuesday.
Fast-moving clipper system is still on target for mid-week, with
model consensus bringing the system across central Illinois on
Wednesday. This particular track is slightly further south than
previously advertised, so WAA ahead of the wave may not be quite as
pronounced as once thought. Even still, high temperatures will
climb well into the 30s and into the lower 40s across the southeast
CWA. End result will be light snow across the far north from the
Peoria area northward, a mix of light rain/snow across much of the
area, and mainly rain south of I-70. Due to the limited period of
light precip and warm temps, snow accumulations will be minimal.
Once this system passes to the east, another shot of cold air will
arrive for Thursday. After that, signs are still pointing to warmer
conditions by the end of the week, with temps climbing well into the
40s by Saturday. Both the GFS and ECMWF indicate a cold front will
drop through the region Saturday night, so temps will likely drop
back into the upper 30s/lower 40s by Sunday/Monday. Moisture will
be limited, so will maintain a dry FROPA at this time.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1147 PM CST SUN NOV 23 2014
The pair of surface low centers have merged and lifted to the NE
of our forecast area, with a trailing cold front to the SW across
IL into southeast Missouri. Drizzle, fog and low clouds are
lingering behind the departing low along that trough, with VLIFR
ceilings at BMI, and LIFR ceilings at the remaining TAF sites.
Expect ceilings to improve slightly with the return redevelopment
of showers well behind the low, but remaining LIFR until Monday
afternoon when levels possibly climb all the way to MVFR.
Cold air will filter into central IL late tonight and Monday
morning, causing the rain showers to mix with or change to light
snow from west to east toward 6 am for PIA/SPI, 8 am for BMI, and
10 am for CMI/DEC. As the precipitation becomes all snow, vsbys
could drop below 1 mile at PIA and BMI where snowfall accumulation
could climb up as high as 1 inch. Vsbys should remain 2-4 miles
farther south toward I-72 where snowfall will be lighter. Snowfall
rates will diminish quickly after 18z-19z, with high winds blowing
any snow around and possibly keeping visibility low at times.
Winds have already become SW behind the low. Pressure rises will
climb to 6 mb/3 hours in at least the southeast half of our
forecast area, which would include DEC/CMI. Wind speeds in our
southeast areas could climb as high as 30g40kt between 12z and 15z
this morning, with other areas 25g35kt. Those speeds could
continue into early afternoon, but we should see some decrease in
peak gusts as the afternoon progresses.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 6 PM CST this evening FOR ILZ044>046-052>057-
061>063-066>068-071>073.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1025 AM EST MON NOV 24 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 340 AM EST MON NOV 24 2014
COLDER AIR WILL RETURN TO CENTRAL INDIANA LATER TODAY BEHIND THE
LOW PRESSURE SYSTEM AND COLD FRONT CURRENTLY IMPACTING THE AREA.
AS A RESULT...RAIN WILL TRANSITION TO SNOW LATE THIS
AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL. AFTER A
CHILLY BUT DRY DAY TOMORROW...ANOTHER SYSTEM WILL BRING LIGHT RAIN
AND SNOW ON WEDNESDAY. FURTHER OUT...THANKSGIVING DAY INTO THE
WEEKEND WILL BE COLD BUT DRY...AND PRECIPITATION WILL RETURN AGAIN
ON SUNDAY.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 1016 AM EST MON NOV 24 2014
FOR THE UPDATE...REMOVED THUNDER CHANCES WITH THE COLD FRONT
THROUGH THE AREA AND ALL THUNDER OFF TO THE EAST. DECREASED POPS
THIS AFTERNOON ACROSS THE NORTH BUT ADDED SOME LOW POPS TO THE
SOUTH BASED ON RECENT RUNS OF THE HRRR AND RAP AND WEAK WAVE
APPROACHING FROM THE SOUTHWEST. ALSO TRANSITIONED TO RAIN SNOW MIX A LITTLE
FASTER IN THE NORTHWEST BASED ON CURRENT OBS OF SNOW IN
ILLINOIS...BUT STILL THINK THE MAJORITY OF THAT WILL HEAD OFF TO
THE NORTHEAST AND MISS THE FORECAST AREA. STILL NOT EXPECTING MUCH
IF ANY ACCUMULATION. BUMPED HIGH END OF WIND GUSTS UP TO 50 MPH IN
THE NPW. TEMPERATURES WILL FALL FOR THE REMAINDER OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM PERIOD WILL BE THE STRONG
SOUTHWEST WINDS...AS WELL AS PRECIP CHANCES AND TYPES.
AN AREA OF LOW PRESSURE IS CURRENTLY POSITIONED OVER LOWER
MICHIGAN WITH A WARM FRONT STRETCHING ACROSS OHIO...AND A TRAILING
COLD FRONT TRACKING ACROSS ILLINOIS. CURRENT RADAR MOSAIC SHOWS
SCATTERED SHOWERS WITH A FEW ISOLATED THUNDERSTORMS OVER MUCH OF
ILLINOIS AND THE SOUTHERN HALF OF CENTRAL INDIANA. FORCING FROM
THE COLD FRONT WILL JUSTIFY LIKELY POPS THROUGH LATE MORNING.
HOWEVER...BEST FORCING WILL BECOME CONFINED TO THE NORTHERN
COUNTIES THIS AFTERNOON AS UPPER TROUGH MOVES THROUGH THE AREA. AS
A RESULT...WILL ONLY CARRY MENTION OF PRECIP OVER THE NORTHERN
HALF OF CENTRAL INDIANA INTO TONIGHT...AND WILL GO WITH A DRY
FORECAST ACROSS THE SOUTHERN HALF. RAIN WILL TRANSITION TO SNOW
LATE THIS AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL
SINCE MOST MOISTURE WILL BE OUT OF THE AREA.
TEMPS WILL START OUT IN THE 50S THIS MORNING...BUT QUICKLY FALL
INTO THE MID 30S THROUGH THE COURSE OF THE DAY AS COLDER AIR
ENTERS THE AREA. TONIGHT...OVERNIGHT LOWS WILL FALL INTO THE UPPER
20S...STUCK CLOSE TO GUIDANCE.
A WIND ADVISORY REMAINS IN EFFECT FOR ALL OF CENTRAL INDIANA TODAY
AS PRESSURE GRADIENT TIGHTENS. SUSTAINED SPEEDS OUT OF THE
SOUTHWEST ARE EXPECTED TO BE BETWEEN 20 TO 25 MPH WITH GUSTS UP TO
45 MPH AT TIMES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 340 AM EST MON NOV 24 2014
DRY AND COOLER WEATHER WILL PREVAIL ON TUESDAY. HOWEVER...THE
PATTERN WILL BECOME MORE ACTIVE AGAIN BY WEDNESDAY AS AN UPPER
TROUGH TRACKS ACROSS THE LOWER MIDWEST. PRECIP SHOULD BE IN THE
FORM OF RAIN ACROSS THE SOUTHERN HALF OF CENTRAL INDIANA ON
WEDNESDAY WITH A RAIN/SNOW MIX OVER THE NORTHERN HALF. AS TEMPS
FALL ON WEDNESDAY NIGHT THOUGH...PRECIP WILL TRANSITION TO SNOW.
MODELS HAVE THIS DISTURBANCE MOVING THROUGH QUICKLY THOUGH...SO
SNOW ACCUMULATIONS SHOULD BE RELATIVELY LOW...LESS THAN AN INCH.
HIGH TEMPS THROUGH THE SHORT TERM PERIOD WILL BE IN THE 30S WITH
LOWS IN THE 20S. THE MAV CONTINUES TO LOOK A TAD TOO WARM...SO
STUCK CLOSER TO A MODEL BLEND.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 340 AM EST MON NOV 24 2014
IN THE LONG TERM MODELS INDICATE A PROGRESSIVE SOMEWHAT ZONAL UPPER
FLOW. A BROAD UPPER TROUGH ACROSS EASTERN CANADA AND THE GREAT LAKES
THURSDAY WILL MOVE ON TO THE EAST TO BE REPLACED BY A WEAKER UPPER
TROUGH BY THE END OF DAY 7.
FOR THANKSGIVING DAY ADDED A CHANCE OF FLURRIES OVER THE EASTERN
HALF OF OUR REGION AS AN UPPER DISTURBANCE MOVES FROM THE UPPER OHIO
VALLEY TO THE EAST COAST. OTHERWISE...DRY WEATHER WILL BE THE RULE
THROUGH FRIDAY NIGHT AS HIGH PRESSURE MOVES OVER THE UPPER MI9WEST
MOVES ACROSS OUR REGION LATE THURSDAY NIGHT AND FRIDAY AND ON TO THE
EAST COAST. SOME MODELS INDICATE LOW CHANCE POPS ACROSS OUR FAR
NORTH FRIDAY...BUT HAVE DECIDED TO KEEP IT DRY FOR NOW.
OVER THE WEEKEND MODELS INDICATE INCREASING WARM ADVECTION AS LOW
PRESSURE MOVES INTO THE PLAINS. THEY ALL GENERATE SOME PRECIP
BEGINNING SATURDAY AND CONTINUING IT THROUGH SUNDAY AS A WARM FRONT
MOVES INTO THE MID MISSISSIPPI VALLEY AND A COLD FRONT APPROACHES
FROM THE UPPER MIDWEST BY SUNDAY.
MODELS HAVE TERNED A LITTLE WARMER OVER THE WEEKEND AND ANY
PRECIPITATION SHOULD BE MOSTLY LIQUID. CONCERNING TEMPERATURES WENT
WITH A MOS BLEND EARLY ON AND SLIGHTLY ABOVE OVER THE WEEKEND AS
WARM ADVECTION INCREASES.
&&
.AVIATION /DISCUSSION FOR THE 241200Z TAF ISSUANCE...
ISSUED AT 923 AM EST MON NOV 24 2014
1420Z UPDATE...VERY FEW CHANGES NEEDED WITH THIS MORNING/S UPDATE.
ONLY NEEDED TO TWEAK THE WINDS AND REMOVE -SHRA AND REPLACE WITH
VCSH FOR THE NEXT FEW HOURS. PREVIOUS DISCUSSION FOLLOWS.
MVFR CEILINGS WITH WORSE CONDITIONS AT TIMES THIS MORNING. GUSTY
WINDS WILL BE THE RULE UNTIL LATE TONIGHT.
RADAR INDICATES NUMEROUS SHOWERS ACROSS THE AREA. A FEW
THUNDERSTORMS COULD AFFECT KIND AND KBMG FOR THE 1ST HOUR BEFORE
THEY MOVE ON TO THE EAST.
MEANWHILE STRONG LOW PRESSURE WAS OVER THE NORTHERN GREAT LAKES AND
A COLD FRONT EXTENDED SOUTH ALONG THE INDIANA ILLINOIS BORDER. THIS
COLD FRONT WILL MOVE RAPIDLY EAST ACROSS INDIANA THIS MORNING. RADAR
LOOPS AND MODELS INDICATE SHOWERS SHOULD DIMINISH BY LATE MORNING.
CEILINGS MAY IMPROVE A LITTLE...BUT WILL MOST LIKELY REMAIN MVFR
CEILINGS THIS AFTERNOON AND WELL INTO TONIGHT.
MORE SIGNIFICANT WILL BE STRONG WEST TO SOUTHWEST WINDS UP TO 25
KNOTS AND GUSTS UP TO 35 KNOTS BY LATE MORNING AND THIS AFTERNOON.
WINDS WILL DECREASE SOME TONIGHT AS PRESSURE GRADIENT RELAXES A
LITTLE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR INZ021-028>030-
035>037-039-043>048-051>057-060>065-067>072.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ031-038-
040>042-049.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....JH
AVIATION...SMF/JH
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AREA FORECAST DISCUSSION
NWS CARIBOU ME
557 AM EST MON NOV 24 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL CROSS THE GREAT LAKES AND MOVE NORTHEAST
INTO QUEBEC PROVINCE TODAY. A COLD FRONT WILL CROSS THE REGION
TONIGHT...WITH A SECOND COLD FRONT CROSSING THE REGION TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
555 AM UPDATE...THE RAIN`S ON ITS WAY...CURRENTLY MOVING INTO FAR
WESTERN MAINE. TEMPERATUERES LOOK TO BE ABOVE FREEZING JUST ABOUT
EVERYWHERE, EXCEPT A FEW COLD SPOTS IN CENTRAL PENOBSCOT/SOUTHERN
PISCATAQUIS COUNTY. EXPECT TEMPERATURES TO CONTINUE TO RISE PRIOR
TO THE RAIN`S ARRIVAL (TEMPS ALREADY IN THE LOWER 40S AT KBGR), SO
DON`T ANTICIPATE MUCH, IF ANY, FROZEN PRECIPITATION TO OCCUR. THE
FORECAST HAS THIS COVERED, SO NO MAJOR CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...LOW PRESSURE CURRENTLY CENTERED NEAR
SOUTHERN LAKE MICHIGAN WILL CONTINUE TO LIFT NORTHEAST INTO
ONTARIO TODAY AND EVENTUALLY INTO QUEBEC THIS EVENING, DEEPENING
AS IT DOES SO. MILD AIR WILL SPREAD INTO NORTHERN NEW ENGLAND ON
THE STRONG SOUTHWEST FLOW AHEAD OF THE LOW AND ITS ATTENDANT
OCCLUDED FRONT. THE SWATH OF FRONTAL/WARM ADVECTION RAIN IS MOVING
INTO EASTERN NEW YORK AND WESTERN NEW ENGLAND EARLY THIS MORNING
AND WILL CONTINUE TO PUSH EASTWARD THROUGH THE DAY. THIS SYSTEM IS
A FAST MOVER, SO THE FRONTAL PASSAGE WILL BE A QUICK ONE. EXPECT
THE RAIN TO MOVE INTO WESTERN SECTIONS OF OUR FORECAST AREA BY
MID-MORNING AND TO EXIT INTO NEW BRUNSWICK BY MID-EVENING, AS
INDICATED BY THE LATEST HRRR MODEL GUIDANCE. THE FRONT ITSELF
WON`T MOVE THROUGH UNTIL A BIT LATER IN THE EVENING, AND WITH
PLENTY OF LOW-LEVEL MOISTURE AROUND, THERE`LL STILL BE THE CHANCE
FOR FOG AND DRIZZLE THROUGH MIDNIGHT OR SO. RAINFALL TOTALS WILL
BE A QUARTER TO A HALF INCH, WITH SOME OF THE UPSLOPE REGIONS IN
THE CENTRAL HIGHLANDS GETTING UP TO THREE-QUARTERS OF AN INCH. THE
OTHER CONCERN WITH THIS SYSTEM IS THE POTENTIAL FOR GUSTY WINDS,
ESPECIALLY ALONG THE DOWNEAST COAST. GUSTS OF 40 MPH WILL BE
POSSIBLE, WHICH MAY CAUSE SOME DOWNED LIMBS OR TREES AND PERHAPS
ISOLATED POWER OUTAGES. TEMPERATURES WILL BE QUITE MILD TODAY AND
TONIGHT; HIGHS WILL RANGE FROM AROUND 50 TO AROUND 55. GUIDANCE IS
EVEN INDICATING THAT TEMPERATURES WILL HOLD STEADY OR EVEN RISE
OVERNIGHT, ONLY FALLING LATE ONCE THE FRONT HAS MOVED THROUGH.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
COLD LLVL ADVCN WILL BE CONTG THRU TUE BEHIND A SECONDARY COLD
FRONT. SKIES WILL BEGIN MCLR TO PTLY CLDY TUE MORN...WITH MORE IN
THE WAY OF BKN-OVC SC AND A SLGT CHC OF SN SHWRS FOR NRN PTNS OF
THE FA LATE TUE INTO TUE NGT AS WHATS LEFT OF AN UPPER TROF SLIDES
EWRD MSLY N OF THE REGION. TEMPS WILL HOLD STEADY THE FIRST FEW
HRS OF TUE MORN...THEN BEGIN TO FALL...SPCLY ACROSS THE N. OVRNGT
TEMPS WILL BE COLDER THAN MON NGT...BUT STILL ABV NORMAL FOR LOWS
ERLY WED MORN.
WED WILL BEGIN PTLY CLDY MOST LCTNS...BUT HI AND MID CLDNSS FROM
THE SFC LOW ADVCG NEWRD FROM THE SE STATES WILL OVRSPRD THE REGION
FROM SW TO NE DURG THE DAY. THE LEADING EDGE OF PRECIP WILL REACH
DOWNEAST AREAS BY MID AFTN AND AT LEAST INTO E CNTRL PTNS OF THE
REGION BY THE BEGINNING OF EVENING. HI TEMPS WED WILL BE ABOUT 10
TO 15 DEG COLDER THAN HI TEMPS TUE. PRECIP MAY BRIEFLY BEGIN AS
LGT RN OR A MIX OF LGT RN/SN OVR DOWNEAST AREAS...BUT EVAPORATIONAL
AND DYNAMIC COOLING FROM ALF SHOULD CHG ANY RN TO ALL SN BY EVE...
XCPT PERHAPS ALG THE IMMEDIATE COAST AND OUTER ISLANDS WHERE RN OR
MIXED RN AND SNOW COULD ON UNTIL LATE TNGT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WE NOTED THAT THE 00Z DTMNSTC ECMWF HAS SHIFTED THE TRACK OF THE
COASTAL LOW FURTHER E THAN RECENT PAST RUNS...NOW TAKING THE LOW
INTO THE ERN BAY OF FUNDY. MEANWHILE...THE 00Z DTMNSTC GFS RUN IS
ALSO A SLIGHTLY MORE E WITH THE TRACK OF THIS SYSTEM COMPARED TO
YSTDY ATTM...ALG WITH THE CORRESPONDING GFS ENSM...BOTH TAKING
THE LOW ALG THE S COAST OF NOVA SCOTIA BY THU MORN. IF THE GFS...
WHICH REPRESENTS THE MIDDLE OF MODELS WITH REGARD TO THE TRACK IS
CORRECT...THE BEST POTENTIAL OF HVY SNFL WED NGT INTO THU MORN
WOULD BE OVR DOWNEAST TO PERHAPS AS FAR N AS E CNTRL PTNS OF THE
FA. GIVEN THE UNCERTAINTIES WITH THIS SYSTEM...WHICH INCLUDES
DIFFICULTIES OF GAGING THE AMPLITUDE OF THE SRN JET STREAM S/WV
SUPPORTING THE SFC LOW AND THE POTENTIAL OF ANY PHASING FROM NRN
JET STREAM S/WV ENERGY...IT IS TO ERLY TO ISSUE ANY WNTR STM
WATCHES ATTM...AND IT IS POSSIBLE THAT THE CONSENSUS MODEL TRACK
COULD SHIFT A LITTLE FURTHER E WITH FUTURE MODEL RUNS. IN ANY
EVENT...WE WILL CONT TO ADVERTISE THIS EVENT IN OUR HAZ WX OUTLOOK
AND HIGHLIGHT A BETTER POTENTIAL OF POSSIBLE WATCHES FOR SPCLY
DOWNEAST AND E CNTRL PTNS OF THE REGION.
OTHERWISE...ANY STEADY SNFL OVR PTNS OF THE FA THU MORN SHOULD
WIND DOWN TO SCT SN SHWRS THU AFTN AS THE SFC LOW TRACKS ENE FROM
NOVA SCOTIA. LEFT OVR LLVL MOISTURE FROM THE EXITING SFC LOW AND
A FOLLOW-UP S/WV FROM S CNTRL CAN WILL KEEP THE CHC OF SN SHWRS
SPCLY FOR THE N HLF OF THE FA THU NGT INTO FRI BEFORE SKIES
FINALLY BECOME CLR TO PTLY CLDY FRI NGT. SEMI-ARCTIC AIR FOLLOWS
THE CAN S/WV FOR FRI NGT. ANOTHER S/WV FROM CNTRL CAN WILL LIKELY
BRING MORE SN SHWR ACTIVITY TO THE REGION LATER SAT INTO SUN AS IT
APCHS AND TRACKS MSLY N OF THE REGION. ENOUGH RETURN SRLY LLVL
WARM ADVCN COULD OCCUR FOR SN SHWRS TO MIX WITH OR CHG TO RN SHWRS
OVR THE S HLF OF THE REGION SUN BEFORE A STRONG COLD FRONT CROSSES
THE REGION BY LATE SUN.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
NEAR TERM: MVFR CONDITIONS ARE EXPECTED TO PREVAIL THIS MORNING,
THEN GIVE WAY TO IFR BY EARLY AFTERNOON AS RAIN SPREADS INTO THE
REGION. THE RAIN WILL TAPER OFF TO SHOWERS BY 00Z, BUT LOWERED
CEILINGS AND REDUCED VISIBILITIES WILL LINGER THROUGH 06Z DUE TO
FOG AND DRIZZLE.
SHORT TO LONG TERM: VFR XPCTD TUE THRU WED MORN...WITH MVFR SC
CLGS POSSIBLE FAR NRN TAF SITES FROM LATE TUE INTO WED.
OTHERWISE...IFR-LIFR IN SN WILL SPREAD NEWRD ACROSS DOWNEAST
SITES LATE WED AND CONT NEWRD THRU THE REMAINDER OF THE TAF SITES
OVRNGT WED. IFR IN SN WILL CONT THU MORN ACROSS NRN TAF SITES...BUT
WILL IMPROVE TO MVFR OVR DOWNEAST SITES. CONDITIONS WILL THEN
IMPROVE TO MVFR NRN TAF SITES IN SC CLGS AND SN SHWR VSBYS THU
AFTN THRU FRI AND IMPROVE TO VFR OVR DOWNEAST SITES.
&&
.MARINE...
NEAR TERM: A GALE WARNING REMAINS IN EFFECT FOR TODAY AND TONIGHT. LOW
PRESSURE MOVING UP WELL TO THE NORTHWEST OF THE WATERS WILL ALLOW
WINDS AND WAVES TO BUILD THIS MORNING, WITH GUSTS TO AROUND 40 KT
POSSIBLE. SEAS WILL BUILD TO 8 TO 12 FEET.
SHORT TO LONG TERM: SCA WINDS AND WV HTS WILL CONT TUE WITH WSW
WIND FETCH AND THEN TAPER TUE NGT. AFT A BRIEF BREAK WED MORN...
WINDS AND SEAS WILL AGAIN INCREASE TO AT LEAST SCA RANGE BY LATE
WED WITH THE APCH OF THE COASTAL LOW FROM THE SW AND CONT OVRNGT
WED INTO THU AS THE LOW TRACKS TOWARD THE MARITIMES. GALE
CONDITIONS ARE POSSIBLE...BUT GIVEN UNCERTAINTIES WITH THE
TRACK AND STRENGTH OF THIS LOW...ITS TO EARLY TO COMMIT WITH
GALE FORCE WINDS WED NGT AND THU ATTM. KEPT CLOSE TO WW3 WV
GUIDANCE FOR WV HTS THIS UPDATE.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST TUESDAY FOR
ANZ050>052.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HASTINGS/VJN
MARINE...HASTINGS/VJN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
728 AM EST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 537 AM EST MON NOV 24 2014
WV IMAGERY AND RUC ANALYSIS SHOWS A MID-UPR LEVEL TROUGH OVER THE
NRN/CENTRAL PLAINS WITH A COUPLE OF STRONG SHORTWAVES OUT AHEAD OF
THIS TROUGH IN A SW FLOW. ONE SHORTWAVE WAS MOVING ACROSS LAKE HURON
NEARLY CO-LOCATED WITH THE 980 MB SFC LOW WHILE ANOTHER SHORTWAVE
WAS TRIGGERING THUNDERSTORMS AS IT LIFTED THROUGH SRN IL AND SRN IN.
DEFORMATION PCPN SHIELD IN COMMA HEAD OF LAKE HURON SHORTWAVE HAS
BEEN RESPONSIBLE FOR THE LIGHT PCPN OVER MUCH OF WEST AND CENTRAL
UPPER MI THIS MORNING WITH SOME MODERATE RAIN OVER ERN UPPER MI. THE
RAIN OVER THE EXISTING SNOW PACK CONTINUES TO SUPPORT AREAS OF FOG
BUT VSBYS OVER MOST AREAS HAVE RISEN ENOUGH TO CANCEL DENSE FOG
ADVISORY.
TODAY...MODELS AND REGIONAL RADAR IMAGERY SUGGEST THAT THERE MAY BE
A LULL IN THE PCPN BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID
LEVEL TROUGH MOVING IN FROM THE UPPER MS VALLEY/NRN PLAINS. AS THE
DEEPENING SFC LOW OVER LAKE HURON LIFTS QUICKLY NE THE COLDER AIR
WILL ALSO SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER
TO SNOW FROM 12Z-21Z FROM W TO EAST PER MODEL SNDGS AND 1000-850 MB
LOW-LVL LEVEL THICKNESS. WITH THE LOSS OF THE STRONGER LARGE SCALE
FORCING/DEEP LAYER Q-VECT CONVERGENCE TIL AFTERNOON EXPECT MAINLY
JUST LIGHT TO MODERATE LAKE ENHANCED SNOW OVER THE WEST HALF FOR NNW
FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO NEAR -8C WEST BY 18Z
AND TO AROUND -12C ACROSS WEST AND NCNTRL LOCATIONS BY 00Z. EXPECT
SNOWFALL AMOUNTS IN THE 2 TO 3 RANGE OVER THE WEST WITH GENERALLY
1-2 INCHES NCNTRL...EXCEPT UP TO 3 INCHES POSSIBLE OVER THE HURON
MOUNTAIN AREA. A TIGHT GRADIENT BEHIND THE LOW WILL BRING STRONG
NRLY WINDS WITH GUSTS TO 30-40 MPH PRODUCING SOME BLOWING AND
DRIFTING SNOW.
TONIGHT...MODELS CONTINUE TO SHOW DEEP MOISTURE/Q-VECTOR CONVERGENCE
AS MID-LVL TROUGH LINGERS OVER THE AREA. ALSO MODEL SOUNDINGS
SUGGEST THE POTENTIAL FOR GOOD SNOW GROWTH AT LEAST THIS EVENING AS
BEST MODEL OMEGA/LIFT INTERSECTS DGZ. CONVERGENT NNW FLOW WILL FAVOR
3-5 INCH ACCUMULATIONS OVER THE HIGHER TERRAIN OF THE WEST AND
NCNTRL COUNTIES WITH PERHAPS ISOLATED 6 INCH AMOUNTS POSSIBLE OVER
THE HURON MOUNTAINS. LAKE ENHANCED SNOW MAY TAPER OFF OVER THE WRN
COUNTIES LATE TONIGHT AS BEST FORCING/Q-VECT CONV BEGINS TO SHIFT
EAST.
CURRENT LAKE EFFECT SNOW ADVISORIES STILL ON TRACK FOR ALL OF WEST
AND NORTH CENTRAL UPPER MI WITH THE GREATEST SNOW TOTAL
ACCUMULATIONS OF 5 TO 9 INCHES EXPECTED OVER HIGHER TERRAIN
LOCATIONS NEAR LAKE SUPERIOR INTO TUESDAY. SOME ISOLATED 10" AMOUNTS
MAY BE POSSIBLE OVER THE HURON MOUNTAINS AIDED BY UPSLOPE FM THE
HIGHER TERRAIN THERE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON NOV 24 2014
LIGHT TO MODERATE LAKE EFFECT WILL BE ONGOING TO START TUESDAY MORNING
WITH DELTA T/S OVER 15C AND NNW LOW-LEVEL WINDS IN WAKE OF THE
DEPARTING SFC LOW PRESSURE TROUGH. INVERSIONS UP TO 5KFT DOES PUT MOST
OF THE CLOUD BEARING LAYER IN THE DGZ...BUT WITH INCREASING DRYING
AND SUBSIDENCE ALOFT AS MAIN SHORTWAVE MOVES EAST...EXPECT THE LAKE EFFECT
TO DIMINISH THROUGH THE DAY AS LOW-LEVEL WINDS BECOME ANTICYCLONIC
AS RIDGE MOVES IN. ENDING TIMES FOR CURRENT LAKE EFFECT ADVISORIES
SEEM GOOD BASED ON THE DIMINISHING TRENDS IN SNOW SHOWERS AND WINDS/BLSN.
TUESDAY NIGHT INTO WEDNESDAY ONE SHORTWAVE AND A LOW PRESSURE SYSTEM
IS EXPECTED TO DIP ESE FM THE NORTHERN PLAINS TOWARD THE MIDDLE
MISSISSIPPI RIVER VALLEY. SWATH OF SNOW SHOULD ACCOMPANY THIS LOW
PRESSURE AREA AND THAT SHOULD STAY MAINLY SOUTH OF UPPER MICHIGAN.
INVERTED SFC TROUGH WILL BE PRESENT TO THE NORTH OF THE MAIN SFC LOW
AND THAT WOULD EXTEND INTO UPR MICHIGAN. SHORTWAVE LIKELY TO BE THE
MAIN FOCUS FOR THE WEATHER OVR CWA ON WEDNESDAY INTO THANKSGIVING IS
IN THE NORTHERN STREAM AND SLIDES OVER THE AREA FM SOUTHERN MANITOBA
AND NORTHWEST ONTARIO IN THE AFTN. OVERALL...PREFER THE OVERALL IDEA
OFFERED BY THE NAM/GFS/ECMWF COMPARED TO THE GEM-NH AS THAT MODEL
SEEMS TOO PHASED WITH THE NORTHERN STREAM AND SOUTHERN STREAM
SHORTWAVES WITH THE RESULT THAT THE THE MAIN SFC LOW IS TOO FAR
NORTH. ECMWF CONTINUES TO SHOW SHARPER TROUGH/CONVERGENCE AND LAKE
ENHANCED SNOW FOR NORTHWEST CWA NOT UNTIL WED NIGHT THEN OVER NCNTRL
CWA ON THANKSGIVING DAY. GFS CONTINUES TO INDICATE WEAKER OVERALL
SYSTEM BUT DOES BRING THE NORTH WIND LAKE EFFECT SNOW SHOWERS IN
EARLIER...MORE SO ON WEDNESDAY AFTN INTO WEDNESDAY NIGHT. GIVEN COLD
POOL OF AIR TO NORTH OF THE SFC TROUGH WITH H85 TEMPS DOWN TO AS LOW
AS -20C THERE WILL BE CERTAINLY BE SOME LAKE EFFECT SNOW SHOWERS
WEDNESDAY INTO THANKSGIVING. IN ADDITION...WILL NEED TO WATCH LAKE
EFFECT OFF LK MICHIGAN IN THE S/SE WINDS AHEAD OF THE SFC TROUGH.
WINDS BACK STEADILY FROM LATE TUESDAY NIGHT INTO WEDNESDAY OVER
NORTHERN LK MICHIGAN. FORECAST SOUNDINGS POINT TO SCT LAKE EFFECT TO
EXPAND OVER MUCH OF THE EASTERN CWA BY LATE WEDNESDAY AS THE ONSHORE
FLOW IS ENHANCED BY THE LARGER SCALE LIFT AND MOISTURE FM THE NEARING
NORTHERN STREAM SHORTWAVE.
SHARPNESS OF SFC TROUGH AND EXTENT OF CONVERGENCE STILL UNCERTAIN
THOUGH WHICH AFFECTS INTENSITY/EXTENT OF THE LES BOTH OFF LK
SUPERIOR AND LK MICHIGAN AND ALSO THE STRENGTH OF WINDS/BLSN NEAR LK
SUPERIOR IN WAKE OF TROUGH. LATEST RUNS OF GFS AND ECMWF KEEP WITH
CONTINUITY COMPARED TO THEIR PREVIOUS RUNS...GIVING NO TREND TO
LATCH ON. THOSE THAT HAVE TRAVEL PLANS WEDNESDAY INTO THANKSGIVING
NEAR LK SUPERIOR AND ALSO OVER MOST OF THE EAST HALF OF UPR MICHIGAN
SHOULD BE AWARE THAT DURING THIS TIME FRAME THERE COULD AT LEAST
LOCALIZED HIGHER IMPACT WEATHER.
HIGH PRESSURE DIVING OVER THE PLAINS WITH RIDGING OVER NORTHERN
ONTARIO EVENTUALLY SHOULD WIN OUT LATER ON THANKSGIVING. THOUGH IF
THE STRONGER TROUGH FM ECMWF IS CORRECT...DIMINISHING TREND IN THE
LAKE EFFECT WOULD BE MORE ON THURSDAY NIGHT. ONCE THE SFC RIDGE
SLIDES EAST ON FRIDAY...UPPER FLOW FLATTENS OUT ALLOWING FOR WARM
AIR ADVECTION TO RAMP UP OVER THE PLAINS. INDICATIONS THAT AT LEAST
ONE SHORTWAVE WILL ALSO BE PROPELLING FROM THE NORTHERN PLAINS
TOWARD THE WESTERN GREAT LAKES. DECENT JET STREAK ALSO FCST OVER THE
PLAINS WHICH SHOULD ENHANCED LIFT ALONG THE TIGHT LOW-LEVEL
BAROCLINIC ZONE. SWATH OF AT LEAST LIGHT SNOW SHOULD RESULT
SOMEWHERE VCNTY OF NORTHERN PLAINS TO THE WESTERN GREAT LAKES.
CONSIDERING THE WAVE THAT WILL GENERATE THE SNOW IS STILL TO EMERGE
FROM UPPER TROUGH OVER NORTHERN PACIFIC VCNTY OF 40N/155W...GFS IS
CONSISTENT IN SHOWING THIS AND GEM-NH IS THERE AS WELL. ECMWF JUST
TRENDED THIS WAY WITH THE 23NOV/12Z RUN. PLENTY OF TIME TO LOOK AT
THE DETAILS BUT DOES APPEAR THAT PTYPE WILL STAY ONLY SNOW AS WARM
AIR AT H85 IS FORECAST TO REMAIN SOUTHWEST OF UPPER LAKES.
MIXED SIGNALS THAT COULD SEE SOME LGT MIXED PRECIP FRIDAY NIGHT INTO
SATURDAY AS THE H9-H8 WARM LAYER ARRIVES. COULD SEE SOME DRIZZLE AND
FOG ISSUES TOO THOUGH AT LEAST RIGHT NOW...GFS/ECMWF ARE NOT SHOWING
DWPNTS AS HIGH AS ARE CURRENTLY OCCURRING OVER AREA. REAL MODEL
DIFFERENCES TO CLOSE THE LONG TERM...WITH 23NOV/12Z ECMWF KEEPING
THE WARM SECTOR OVER THE AREA INTO SUNDAY...WHILE THE GFS SHOVES
SHARPER COLD FRONT OVER THE UPPER GREAT LAKES BY SUNDAY. AT 12Z
SUNDAY...H85 TEMPS VARY FROM -5C OFF THAT RUN OF ECMWF TO -24C
OFF THE GFS. LATEST ECMWF TRENDED TOWARD GFS AS IT NOW SHOWS H85
TEMP THAT SAME TIME OF -16C. USED A CONSENSUS OF THE MODELS UNTIL
THE DIFFERENCES ARE RESOLVED...BUT GIVEN THE TREND FM THE LATEST
ECMWF...WENT WITH A BIT HIGHER POPS AND LOWERED TEMPS SLIGHTLY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 721 AM EST MON NOV 24 2014
EXPECT LIFR CIGS TO PERSIST THROUGH THIS MORNING. AS A DEEP LOW
PRESSURE SYSTEM MOVES NORTHEAST OF THE AREA THIS MORNING WINDS WILL
BECOME NNW AND QUICKLY STRENGTHEN WITH ANY RAIN CHANGING TO SNOW.
CIGS MAY IMPROVE SOME THRU PD WITH INCREASED MIXING FROM INFLUX OF
COLDER AIR AND STRONGER WINDS. EXPECT LOWER IFR VSBY ONCE HEAVIER SNOW
SETS UP THIS AFTERNOON INTO THIS EVENING WITH IMPROVEMENT LATE
TONIGHT FROM WEST AS RIDGE BEGINS TO BUILD IN AND SNOW TAPERS OFF.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 537 AM EST MON NOV 24 2014
A DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR TODAY. NORTHERLY
WINDS WILL INCREASE TO GALES 35-45 KTS BY THIS MORNING INTO MONDAY
NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS WED NIGHT INTO THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
THERE MAY BE A BRIEF PD OF GALES TO 35 KNOTS OVER NCNTRL LAKE
SUPERIOR WED NIGHT. WINDS WILL DECREASE TO LESS THAN 25 KNOTS THU
NIGHT INTO FRI AS A HIGH PRES RIDGE MOVES OVER THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR MIZ006-007-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM THIS MORNING TO 6 AM EST
TUESDAY FOR MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
TUESDAY FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 AM EST TUESDAY FOR
LSZ251-267.
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ246>250-265-266.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TODAY TO 9 PM EST /8 PM
CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
538 AM EST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 537 AM EST MON NOV 24 2014
WV IMAGERY AND RUC ANALYSIS SHOWS A MID-UPR LEVEL TROUGH OVER THE
NRN/CENTRAL PLAINS WITH A COUPLE OF STRONG SHORTWAVES OUT AHEAD OF
THIS TROUGH IN A SW FLOW. ONE SHORTWAVE WAS MOVING ACROSS LAKE HURON
NEARLY CO-LOCATED WITH THE 980 MB SFC LOW WHILE ANOTHER SHORTWAVE
WAS TRIGGERING THUNDERSTORMS AS IT LIFTED THROUGH SRN IL AND SRN IN.
DEFORMATION PCPN SHIELD IN COMMA HEAD OF LAKE HURON SHORTWAVE HAS
BEEN RESPONSIBLE FOR THE LIGHT PCPN OVER MUCH OF WEST AND CENTRAL
UPPER MI THIS MORNING WITH SOME MODERATE RAIN OVER ERN UPPER MI. THE
RAIN OVER THE EXISTING SNOW PACK CONTINUES TO SUPPORT AREAS OF FOG
BUT VSBYS OVER MOST AREAS HAVE RISEN ENOUGH TO CANCEL DENSE FOG
ADVISORY.
TODAY...MODELS AND REGIONAL RADAR IMAGERY SUGGEST THAT THERE MAY BE
A LULL IN THE PCPN BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID
LEVEL TROUGH MOVING IN FROM THE UPPER MS VALLEY/NRN PLAINS. AS THE
DEEPENING SFC LOW OVER LAKE HURON LIFTS QUICKLY NE THE COLDER AIR
WILL ALSO SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER
TO SNOW FROM 12Z-21Z FROM W TO EAST PER MODEL SNDGS AND 1000-850 MB
LOW-LVL LEVEL THICKNESS. WITH THE LOSS OF THE STRONGER LARGE SCALE
FORCING/DEEP LAYER Q-VECT CONVERGENCE TIL AFTERNOON EXPECT MAINLY
JUST LIGHT TO MODERATE LAKE ENHANCED SNOW OVER THE WEST HALF FOR NNW
FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO NEAR -8C WEST BY 18Z
AND TO AROUND -12C ACROSS WEST AND NCNTRL LOCATIONS BY 00Z. EXPECT
SNOWFALL AMOUNTS IN THE 2 TO 3 RANGE OVER THE WEST WITH GENERALLY
1-2 INCHES NCNTRL...EXCEPT UP TO 3 INCHES POSSIBLE OVER THE HURON
MOUNTAIN AREA. A TIGHT GRADIENT BEHIND THE LOW WILL BRING STRONG
NRLY WINDS WITH GUSTS TO 30-40 MPH PRODUCING SOME BLOWING AND
DRIFTING SNOW.
TONIGHT...MODELS CONTINUE TO SHOW DEEP MOISTURE/Q-VECTOR CONVERGENCE
AS MID-LVL TROUGH LINGERS OVER THE AREA. ALSO MODEL SOUNDINGS
SUGGEST THE POTENTIAL FOR GOOD SNOW GROWTH AT LEAST THIS EVENING AS
BEST MODEL OMEGA/LIFT INTERSECTS DGZ. CONVERGENT NNW FLOW WILL FAVOR
3-5 INCH ACCUMULATIONS OVER THE HIGHER TERRAIN OF THE WEST AND
NCNTRL COUNTIES WITH PERHAPS ISOLATED 6 INCH AMOUNTS POSSIBLE OVER
THE HURON MOUNTAINS. LAKE ENHANCED SNOW MAY TAPER OFF OVER THE WRN
COUNTIES LATE TONIGHT AS BEST FORCING/Q-VECT CONV BEGINS TO SHIFT
EAST.
CURRENT LAKE EFFECT SNOW ADVISORIES STILL ON TRACK FOR ALL OF WEST
AND NORTH CENTRAL UPPER MI WITH THE GREATEST SNOW TOTAL
ACCUMULATIONS OF 5 TO 9 INCHES EXPECTED OVER HIGHER TERRAIN
LOCATIONS NEAR LAKE SUPERIOR INTO TUESDAY. SOME ISOLATED 10" AMOUNTS
MAY BE POSSIBLE OVER THE HURON MOUNTAINS AIDED BY UPSLOPE FM THE
HIGHER TERRAIN THERE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON NOV 24 2014
LIGHT TO MODERATE LAKE EFFECT WILL BE ONGOING TO START TUESDAY MORNING
WITH DELTA T/S OVER 15C AND NNW LOW-LEVEL WINDS IN WAKE OF THE
DEPARTING SFC LOW PRESSURE TROUGH. INVERSIONS UP TO 5KFT DOES PUT MOST
OF THE CLOUD BEARING LAYER IN THE DGZ...BUT WITH INCREASING DRYING
AND SUBSIDENCE ALOFT AS MAIN SHORTWAVE MOVES EAST...EXPECT THE LAKE EFFECT
TO DIMINISH THROUGH THE DAY AS LOW-LEVEL WINDS BECOME ANTICYCLONIC
AS RIDGE MOVES IN. ENDING TIMES FOR CURRENT LAKE EFFECT ADVISORIES
SEEM GOOD BASED ON THE DIMINISHING TRENDS IN SNOW SHOWERS AND WINDS/BLSN.
TUESDAY NIGHT INTO WEDNESDAY ONE SHORTWAVE AND A LOW PRESSURE SYSTEM
IS EXPECTED TO DIP ESE FM THE NORTHERN PLAINS TOWARD THE MIDDLE
MISSISSIPPI RIVER VALLEY. SWATH OF SNOW SHOULD ACCOMPANY THIS LOW
PRESSURE AREA AND THAT SHOULD STAY MAINLY SOUTH OF UPPER MICHIGAN.
INVERTED SFC TROUGH WILL BE PRESENT TO THE NORTH OF THE MAIN SFC LOW
AND THAT WOULD EXTEND INTO UPR MICHIGAN. SHORTWAVE LIKELY TO BE THE
MAIN FOCUS FOR THE WEATHER OVR CWA ON WEDNESDAY INTO THANKSGIVING IS
IN THE NORTHERN STREAM AND SLIDES OVER THE AREA FM SOUTHERN MANITOBA
AND NORTHWEST ONTARIO IN THE AFTN. OVERALL...PREFER THE OVERALL IDEA
OFFERED BY THE NAM/GFS/ECMWF COMPARED TO THE GEM-NH AS THAT MODEL
SEEMS TOO PHASED WITH THE NORTHERN STREAM AND SOUTHERN STREAM
SHORTWAVES WITH THE RESULT THAT THE THE MAIN SFC LOW IS TOO FAR
NORTH. ECMWF CONTINUES TO SHOW SHARPER TROUGH/CONVERGENCE AND LAKE
ENHANCED SNOW FOR NORTHWEST CWA NOT UNTIL WED NIGHT THEN OVER NCNTRL
CWA ON THANKSGIVING DAY. GFS CONTINUES TO INDICATE WEAKER OVERALL
SYSTEM BUT DOES BRING THE NORTH WIND LAKE EFFECT SNOW SHOWERS IN
EARLIER...MORE SO ON WEDNESDAY AFTN INTO WEDNESDAY NIGHT. GIVEN COLD
POOL OF AIR TO NORTH OF THE SFC TROUGH WITH H85 TEMPS DOWN TO AS LOW
AS -20C THERE WILL BE CERTAINLY BE SOME LAKE EFFECT SNOW SHOWERS
WEDNESDAY INTO THANKSGIVING. IN ADDITION...WILL NEED TO WATCH LAKE
EFFECT OFF LK MICHIGAN IN THE S/SE WINDS AHEAD OF THE SFC TROUGH.
WINDS BACK STEADILY FROM LATE TUESDAY NIGHT INTO WEDNESDAY OVER
NORTHERN LK MICHIGAN. FORECAST SOUNDINGS POINT TO SCT LAKE EFFECT TO
EXPAND OVER MUCH OF THE EASTERN CWA BY LATE WEDNESDAY AS THE ONSHORE
FLOW IS ENHANCED BY THE LARGER SCALE LIFT AND MOISTURE FM THE NEARING
NORTHERN STREAM SHORTWAVE.
SHARPNESS OF SFC TROUGH AND EXTENT OF CONVERGENCE STILL UNCERTAIN
THOUGH WHICH AFFECTS INTENSITY/EXTENT OF THE LES BOTH OFF LK
SUPERIOR AND LK MICHIGAN AND ALSO THE STRENGTH OF WINDS/BLSN NEAR LK
SUPERIOR IN WAKE OF TROUGH. LATEST RUNS OF GFS AND ECMWF KEEP WITH
CONTINUITY COMPARED TO THEIR PREVIOUS RUNS...GIVING NO TREND TO
LATCH ON. THOSE THAT HAVE TRAVEL PLANS WEDNESDAY INTO THANKSGIVING
NEAR LK SUPERIOR AND ALSO OVER MOST OF THE EAST HALF OF UPR MICHIGAN
SHOULD BE AWARE THAT DURING THIS TIME FRAME THERE COULD AT LEAST
LOCALIZED HIGHER IMPACT WEATHER.
HIGH PRESSURE DIVING OVER THE PLAINS WITH RIDGING OVER NORTHERN
ONTARIO EVENTUALLY SHOULD WIN OUT LATER ON THANKSGIVING. THOUGH IF
THE STRONGER TROUGH FM ECMWF IS CORRECT...DIMINISHING TREND IN THE
LAKE EFFECT WOULD BE MORE ON THURSDAY NIGHT. ONCE THE SFC RIDGE
SLIDES EAST ON FRIDAY...UPPER FLOW FLATTENS OUT ALLOWING FOR WARM
AIR ADVECTION TO RAMP UP OVER THE PLAINS. INDICATIONS THAT AT LEAST
ONE SHORTWAVE WILL ALSO BE PROPELLING FROM THE NORTHERN PLAINS
TOWARD THE WESTERN GREAT LAKES. DECENT JET STREAK ALSO FCST OVER THE
PLAINS WHICH SHOULD ENHANCED LIFT ALONG THE TIGHT LOW-LEVEL
BAROCLINIC ZONE. SWATH OF AT LEAST LIGHT SNOW SHOULD RESULT
SOMEWHERE VCNTY OF NORTHERN PLAINS TO THE WESTERN GREAT LAKES.
CONSIDERING THE WAVE THAT WILL GENERATE THE SNOW IS STILL TO EMERGE
FROM UPPER TROUGH OVER NORTHERN PACIFIC VCNTY OF 40N/155W...GFS IS
CONSISTENT IN SHOWING THIS AND GEM-NH IS THERE AS WELL. ECMWF JUST
TRENDED THIS WAY WITH THE 23NOV/12Z RUN. PLENTY OF TIME TO LOOK AT
THE DETAILS BUT DOES APPEAR THAT PTYPE WILL STAY ONLY SNOW AS WARM
AIR AT H85 IS FORECAST TO REMAIN SOUTHWEST OF UPPER LAKES.
MIXED SIGNALS THAT COULD SEE SOME LGT MIXED PRECIP FRIDAY NIGHT INTO
SATURDAY AS THE H9-H8 WARM LAYER ARRIVES. COULD SEE SOME DRIZZLE AND
FOG ISSUES TOO THOUGH AT LEAST RIGHT NOW...GFS/ECMWF ARE NOT SHOWING
DWPNTS AS HIGH AS ARE CURRENTLY OCCURRING OVER AREA. REAL MODEL
DIFFERENCES TO CLOSE THE LONG TERM...WITH 23NOV/12Z ECMWF KEEPING
THE WARM SECTOR OVER THE AREA INTO SUNDAY...WHILE THE GFS SHOVES
SHARPER COLD FRONT OVER THE UPPER GREAT LAKES BY SUNDAY. AT 12Z
SUNDAY...H85 TEMPS VARY FROM -5C OFF THAT RUN OF ECMWF TO -24C
OFF THE GFS. LATEST ECMWF TRENDED TOWARD GFS AS IT NOW SHOWS H85
TEMP THAT SAME TIME OF -16C. USED A CONSENSUS OF THE MODELS UNTIL
THE DIFFERENCES ARE RESOLVED...BUT GIVEN THE TREND FM THE LATEST
ECMWF...WENT WITH A BIT HIGHER POPS AND LOWERED TEMPS SLIGHTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1233 AM EST MON NOV 24 2014
PERSISTENT LOW CIGS AND FOG WILL CONTINUE OVERNIGHT WITH VLIFR TO
LIFR CONDITIONS PERSISTING. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST
OF THE AREA MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY
STRENGTHEN WITH ANY RAIN CHANGING TO SNOW. LOW CIGS AND VIS WILL
CONTINUE AT ALL TAF SITES THROUGH THE REST OF THE FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 537 AM EST MON NOV 24 2014
A DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR TODAY. NORTHERLY
WINDS WILL INCREASE TO GALES 35-45 KTS BY THIS MORNING INTO MONDAY
NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS WED NIGHT INTO THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
THERE MAY BE A BRIEF PD OF GALES TO 35 KNOTS OVER NCNTRL LAKE
SUPERIOR WED NIGHT. WINDS WILL DECREASE TO LESS THAN 25 KNOTS THU
NIGHT INTO FRI AS A HIGH PRES RIDGE MOVES OVER THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR MIZ006-007-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM THIS MORNING TO 6 AM EST
TUESDAY FOR MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
TUESDAY FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 AM EST TUESDAY FOR
LSZ251-267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TODAY TO 9 PM EST /8 PM
CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
529 AM CST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 529 AM CST MON NOV 24 2014
...NW WINDS GUST 35-40 MPH WITH ISOLATED G45 WITH DIMINISHING
CLOUDS IN MOSTLY COLDER THAN NORMAL TEMPS...
ALOFT: THE NEWLY REESTABLISHED LONGWAVE TROF AXIS WAS SHIFTING E
OF THE FCST AREA. BACK TO NW FLOW THRU TONIGHT. THE NEXT SHORTWAVE
TROF TO AFFECT THE FCST AREA WAS OVER BRITISH COLUMBIA. THIS TROF
WILL PASS THRU HERE TONIGHT WITH ONLY AN INCREASE IN HIGH CLOUDS.
SURFACE: THE FCST AREA WAS IN THE COLD SECTOR OF DEEP LOW PRES
OVER THE GREAT LAKES THIS MORNING. WE WILL REMAIN IN THE COLD
SECTOR THRU TONIGHT. WRN USA HIGH PRES WILL GRADUALLY BUILD IN
WITH CYCLONIC BOUNDARY LAYER FLOW BECOMING ANTICYCLONIC. ITS RIDGE
AXIS WILL PASS THRU AFTER MIDNIGHT. A CLIPPER WILL FORM OVER WRN
CANADA TONIGHT AND AN ASSOCIATED WARM FRONT WILL DEVELOP SOUTHWARD
INTO THE REGION.
529 AM: LOTS OF WRAP AROUND CLOUDS IN CYCLONIC NW FLOW...N AND E
OF THE TRI-CITIES. STILL CANT RULE OUT A STRAY FLURRY ALTHOUGH
HAVE NOT SEEN ANY IN REGIONAL OBS RECENTLY.
BBW MEASURED A G39 KTS AT 421 AM. THAT IS INDICATIVE OF WHAT OUR
MAX WIND POTENTIAL IS TODAY ONCE CONVECTIVE MIXING COMMENCES.
TODAY: CONTINUED WINDY. NW WINDS WILL GUST 30-35 KTS IN DOWNWARD
TRANSFER AS THE BOUNDARY LAYER BECOMES UNSTABLE. POTENTIAL PEAK
GUSTS AS HIGH AS 40 KTS PER BUFKIT MIXING ALGORITHM. USED GFS
WITH ITS DEEPER MIXING.
THE RAP/NAM/GFS AGREE THE WRN FRINGE OF THE WRAP-AROUND CLOUDS
WILL GRADUALLY SHIFT E OF THE FCST AREA LEAVING SKIES SUNNY.
SIMULATED IR IMAGERY FROM THE 4 KM NAM NEST SUGGESTS SOME PATCHES
OF CIRROSTRATUS WILL BEGIN MOVING IN FROM THE NW LATE AND THIS
IS REASONABLE BASED ON CURRENT SATELLITE...WITH THE NRN ROCKIES
SHORTWAVE TROF DIVING TO OUR W.
INTERNAL VERIFICATION SHOWS WE HAVE BEEN RUNNING TOO COOL ON HIGH
TEMPS RECENTLY. SO USED 06Z RAP TO NUDGE TEMPS UPWARD SLIGHTLY.
HIGHS WILL STILL BE 5-10F COLDER THAN NORMAL FOR MOST OF THE FCST
AREA.
TONIGHT: WINDS DROP OFF EARLY EVENING WITH DECOUPLING. PATCHES OF
CIRROSTRATUS CONT TO DRIFT THRU BUT SHOULD BE NO WORSE THAN
P/CLOUDY.
USED THE WEIGHTED CONSENSUS OF THE 3 BEST-VERIFYING TEMP GUIDES
FOR LOWS...WHICH FAVORED THE COLDER MOS TEMPS. JUST SLIGHTLY
COLDER THAN NORMAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 407 AM CST MON NOV 24 2014
THE BIG HOLIDAY WEEKEND IS FAST APPROACHING AND NO TRAVEL
PROBLEMS ARE EXPECTED ACROSS NEBRASKA AND KANSAS. ALWAYS REMEMBER
YOU CAN CHECK WWW.WEATHER.GOV FOR THE LATEST WEATHER CONDITIONS
AND FORECAST FOR ANYWHERE IN THE COUNTRY WHERE YOU MIGHT BE
TRAVELING TO THIS HOLIDAY WEEKEND.
THE BIGGEST CONCERN FOR OUR AREA DURING THE HOLIDAY WEEKEND WILL
CENTER AROUND SEVERAL BIG TEMPERATURE SWINGS.
TUESDAY...THIS SHOULD BE A WARMER DAY WITH LIGHTER WINDS. THE
STRONG NORTHWEST WIND OF SUNDAY AND MONDAY WILL GIVE WAY TO A MORE
GENTLE SOUTHWESTERLY BREEZE THAT WILL HELP TO WARM HIGHS INTO THE
MID AND UPPER 40S ACROSS MOST NEBRASKA ZONES TO THE LOWER 50S
ACROSS PORTIONS OF NORTHERN KANSAS. THERE ARE SOME MODEL
DIFFERENCES WITH THE 00Z GFS TRYING TO BRING THE NEXT COLD FRONT
INTO NEBRASKA ZONES BY TUESDAY AFTERNOON ALONG WITH SOME SPRINKLES
AND SLIGHTLY COOLER AIR. HOWEVER...THE 00Z NAM AND 00Z GFS ARE
BOTH SLOWER WITH THE COLD FRONT AND ARE DRY. THIS FORECAST LEANS
TOWARDS THE ECMWF/NAM SOLUTION.
TUESDAY NIGHT INTO WEDNESDAY...COOLER AIR WILL FILTER INTO OUR
REGION BEHIND A COLD FRONT. WE CAN NOT RULE OUT A FLURRY OR
TWO...BUT GIVEN MOST FORECAST MODELS ARE COMPLETELY DRY...WE WILL
KEEP THE FORECAST DRY AND WITHHOLD ANY FLURRIES FOR NOW. FORECAST
MODELS ARE NOT AS COLD WITH THIS AIRMASS AS THEY WERE SEVERAL DAYS
AGO AND EXPECT HIGHS ON WEDNESDAY SHOULD STILL REACH THE UPPER 30S
ACROSS NORTHEASTERN ZONES TO THE MID 40S OVER NORTH CENTRAL
KANSAS.
THANKSGIVING...UNFORTUNATELY THE HOLIDAY ITSELF APPEARS TO THE BE
COLDEST DAY OF THE WEEKEND AS THE COOLER AIR THAT SETTLES IN ON
WEDNESDAY MAY HANG AROUND THROUGH THANKSGIVING DAY.
HOWEVER...FORECAST MODELS HAVE BEEN TRENDING WARMER AND SO WOULD
NOT BE SURPRISED IF OUR FORECAST HIGHS ON THANKSGIVING DAY
EVENTUALLY GET RAISED SOME. FOR NOW WILL CONTINUE TO GO WITH THE
OVERALL SUPERBLEND OF MODELS...WHICH RESULTS IN HIGHS IN THE MID
30S IN THE TRI-CITIES...TO THE LOWER AND MID 40S OVER NORTHERN
KANSAS.
FRIDAY THROUGH SUNDAY...THE OVERALL UPPER FLOW BECOMES MORE ZONAL
WITH THE REAL COLD AIR BOXED UP IN CANADA. THIS WILL ALSO KEEP THE
STORM TRACK WELL TO OUR NORTH RESULTING IN CONTINUED DRY
CONDITIONS. THERE IS GOOD CONFIDENCE IN FRIDAY BEING A VERY NICE
DAY WITH HIGHS LIKELY AROUND 50 IN THE TRI-CITIES TO THE MID AND
UPPER 50S OVER NORTH CENTRAL KANSAS WITH JUST A LIGHT SOUTHWEST
WIND. SATURDAY IS MUCH MORE UNCERTAIN WITH A COLD FRONT ON OUR
DOOR STEP. THE LATEST 00Z ECMWF IS SLOWER WITH THE COLD FRONT AND
INDICATES THAT HIGHS ON SATURDAY MAY BE EVEN WARMER THAN ON FRIDAY
POSSIBLY REACHING INTO THE 60S...BUT THE 00Z GFS IS MUCH QUICKER
WITH THE COLD FRONT AND WOULD HAVE TEMPERATURES FALLING THROUGH
THE 30S SATURDAY AFTERNOON. OUR OFFICIAL FORECAST IS CURRENTLY
SOMEWHERE IN THE MIDDLE WITH A HIGH DEGREE OF UNCERTAINTY AT THIS
TIME. CONFIDENCE REALLY DOES NOT IMPROVE MUCH ON SUNDAY AS THERE
IS UNCERTAINTY WITH REGARD TO HOW COLD THE NEXT AIR MASS WILL BE.
THE 00Z GFS AND 00Z ECMWF HAVE BOTH TRENDED DOWNWARD AND WOULD
RESULT IN HIGHS ONLY IN THE 20S ON SUNDAY WHILE OUR FORECAST STILL
IS INCORPORATING RECENT RUNS THAT WERE WARMER AND IS CALLING FOR
HIGHS IN THE 30S AND 40S. BASICALLY...EXPECT FORECAST CHANGES IN
THE COMING DAYS AS THE UNCERTAINTY ISSUES GET IRONED OUT.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z TUE MORNING)
ISSUED AT 529 AM CST MON NOV 24 2014
TODAY: A PERIOD OF 2000-2500 FT MVFR CIGS APPEARS LIKELY FOR 2-3
HRS THIS MORNING. HIGHEST PROBABILITY AT GRI WHERE WE MADE IT
PREVAILING. CONFIDENCE IS LOWER AT EAR WHERE THE WRN EDGE OF THIS
DECK OF STRATOCU MAY JUST SKIRT THE AIRPORT FOR A TIME. SO HANDLED
WITH JUST A TEMPO GROUP THERE. OTHERWISE...VFR CLEARING AFTER
15Z. NW WINDS WILL GUST 27-32 KTS WITH POTENTIAL FOR A PKWND OF 40
KTS. BBW GUSTED TO 39 KTS LAST HOUR. CONFIDENCE: HIGH
TONIGHT: VFR PATCHES OF PRIMARILY SCT CIRROSTRATUS. NW WINDS
RAPIDLY DIMINISH 23Z-01Z TO AROUND 10 KTS AND THEN GRADUALLY SHIFT
THRU WNW TO W UNDER 10 KTS AFTER 06Z. CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
408 AM CST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 240 AM CST MON NOV 24 2014
ALOFT: THE NEWLY REESTABLISHED LONGWAVE TROF AXIS WAS SHIFTING E
OF THE FCST AREA. BACK TO NW FLOW THRU TONIGHT. THE NEXT SHORTWAVE
TROF TO AFFECT THE FCST AREA WAS OVER BRITISH COLUMBIA. THIS TROF
WILL PASS THRU HERE TONIGHT WITH ONLY AN INCREASE IN HIGH CLOUDS.
SURFACE: THE FCST AREA WAS IN THE COLD SECTOR OF DEEP LOW PRES
OVER THE GREAT LAKES THIS MORNING. WE WILL REMAIN IN THE COLD
SECTOR THRU TONIGHT. WRN USA HIGH PRES WILL GRADUALLY BUILD IN
WITH CYCLONIC BOUNDARY LAYER FLOW BECOMING ANTICYCLONIC. ITS RIDGE
AXIS WILL PASS THRU AFTER MIDNIGHT. A CLIPPER WILL FORM OVER WRN
CANADA TONIGHT AND AN ASSOCIATED WARM FRONT WILL DEVELOP SOUTHWARD
INTO THE REGION.
NOW: TEMPS CONT STRUGGLING TO DROP. TEMPS ARE STILL IN THE 30S
ACROSS THE ENTIRE FCST AREA. SO LOW TEMPS WERE RAISED SVRL DEGS
FROM THE 4 PM FCST.
EARLY THIS MORNING: LOTS OF WRAP AROUND CLOUDS IN CYCLONIC NW
FLOW.
TODAY: CONTINUED WINDY. NW WINDS WILL GUST 30-35 KTS IN DOWNWARD
TRANSFER AS THE BOUNDARY LAYER BECOMES UNSTABLE. POTENTIAL PEAK
GUSTS AS HIGH AS 38 KTS PER BUFKIT MIXING ALGORITHM. USED GFS WITH
ITS DEEPER MIXING.
THE RAP/NAM/GFS AGREE THE WRN FRINGE OF THE WRAP-AROUND CLOUDS
WILL GRADUALLY SHIFT E OF THE FCST AREA LEAVING SKIES SUNNY.
SIMULATED IR IMAGERY FROM THE 4 KM NAM NEST SUGGESTS SOME PATCHES
OF CIRROSTRATUS WILL BEGIN MOVING IN FROM THE NW LATE AND THIS
IS REASONABLE BASED ON CURRENT SATELLITE...WITH THE NRN ROCKIES
SHORTWAVE TROF DIVING TO OUR W.
INTERNAL VERIFICATION SHOWS WE HAVE BEEN RUNNING TOO COOL ON HIGH
TEMPS RECENTLY. SO USED 06Z RAP TO NUDGE TEMPS UPWARD SLIGHTLY.
HIGHS WILL STILL BE 5-10F COLDER THAN NORMAL FOR MOST OF THE FCST
AREA.
TONIGHT: WINDS DROP OFF EARLY EVENING WITH DECOUPLING. PATCHES OF
CIRROSTRATUS CONT TO DRIFT THRU BUT SHOULD BE NO WORSE THAN
P/CLOUDY.
USED THE WEIGHTED CONSENSUS OF THE 3 BEST-VERIFYING TEMP GUIDES
FOR LOWS...WHICH FAVORED THE COLDER MOS TEMPS. JUST SLIGHTLY
COLDER THAN NORMAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 407 AM CST MON NOV 24 2014
THE BIG HOLIDAY WEEKEND IS FAST APPROACHING AND NO TRAVEL PROBLEMS
ARE EXPECTED ACROSS NEBRASKA AND KANSAS. ALWAYS REMEMBER YOU CAN
CHECK WWW.WEATHER.GOV FOR THE LATEST WEATHER CONDITIONS AND FORECAST
FOR ANYWHERE IN THE COUNTRY WHERE YOU MIGHT BE TRAVELING TO THIS
HOLIDAY WEEKEND.
THE BIGGEST CONCERN FOR OUR AREA DURING THE HOLIDAY WEEKEND WILL
CENTER AROUND SEVERAL BIG TEMPERATURE SWINGS.
TUESDAY...THIS SHOULD BE A WARMER DAY WITH LIGHTER WINDS. THE STRONG
NORTHWEST WIND OF SUNDAY AND MONDAY WILL GIVE WAY TO A MORE GENTLE
SOUTHWESTERLY BREEZE THAT WILL HELP TO WARM HIGHS INTO THE MID AND
UPPER 40S ACROSS MOST NEBRASKA ZONES TO THE LOWER 50S ACROSS
PORTIONS OF NORTHERN KANSAS. THERE ARE SOME MODEL DIFFERENCES WITH
THE 00Z GFS TRYING TO BRING THE NEXT COLD FRONT INTO NEBRASKA ZONES
BY TUESDAY AFTERNOON ALONG WITH SOME SPRINKLES AND SLIGHTLY COOLER
AIR. HOWEVER...THE 00Z NAM AND 00Z GFS ARE BOTH SLOWER WITH THE COLD
FRONT AND ARE DRY. THIS FORECAST LEANS TOWARDS THE ECMWF/NAM
SOLUTION.
TUESDAY NIGHT INTO WEDNESDAY...COOLER AIR WILL FILTER INTO OUR
REGION BEHIND A COLD FRONT. WE CAN NOT RULE OUT A FLURRY OR
TWO...BUT GIVEN MOST FORECAST MODELS ARE COMPLETELY DRY...WE WILL
KEEP THE FORECAST DRY AND WITHHOLD ANY FLURRIES FOR NOW. FORECAST
MODELS ARE NOT AS COLD WITH THIS AIRMASS AS THEY WERE SEVERAL DAYS
AGO AND EXPECT HIGHS ON WEDNESDAY SHOULD STILL REACH THE UPPER 30S
ACROSS NORTHEASTERN ZONES TO THE MID 40S OVER NORTH CENTRAL KANSAS.
THANKSGIVING...UNFORTUNATELY THE HOLIDAY ITSELF APPEARS TO THE BE
COLDEST DAY OF THE WEEKEND AS THE COOLER AIR THAT SETTLES IN ON
WEDNESDAY MAY HANG AROUND THROUGH THANKSGIVING DAY.
HOWEVER...FORECAST MODELS HAVE BEEN TRENDING WARMER AND SO WOULD NOT
BE SURPRISED IF OUR FORECAST HIGHS ON THANKSGIVING DAY EVENTUALLY
GET RAISED SOME. FOR NOW WILL CONTINUE TO GO WITH THE OVERALL
SUPERBLEND OF MODELS...WHICH RESULTS IN HIGHS IN THE MID 30S IN THE
TRI-CITIES...TO THE LOWER AND MID 40S OVER NORTHERN KANSAS.
FRIDAY THROUGH SUNDAY...THE OVERALL UPPER FLOW BECOMES MORE ZONAL
WITH THE REAL COLD AIR BOXED UP IN CANADA. THIS WILL ALSO KEEP THE
STORM TRACK WELL TO OUR NORTH RESULTING IN CONTINUED DRY CONDITIONS.
THERE IS GOOD CONFIDENCE IN FRIDAY BEING A VERY NICE DAY WITH HIGHS
LIKELY AROUND 50 IN THE TRI-CITIES TO THE MID AND UPPER 50S OVER
NORTH CENTRAL KANSAS WITH JUST A LIGHT SOUTHWEST WIND. SATURDAY IS
MUCH MORE UNCERTAIN WITH A COLD FRONT ON OUR DOOR STEP. THE LATEST
00Z ECMWF IS SLOWER WITH THE COLD FRONT AND INDICATES THAT HIGHS ON
SATURDAY MAY BE EVEN WARMER THAN ON FRIDAY POSSIBLY REACHING INTO
THE 60S...BUT THE 00Z GFS IS MUCH QUICKER WITH THE COLD FRONT AND
WOULD HAVE TEMPERATURES FALLING THROUGH THE 30S SATURDAY AFTERNOON.
OUR OFFICIAL FORECAST IS CURRENTLY SOMEWHERE IN THE MIDDLE WITH A
HIGH DEGREE OF UNCERTAINTY AT THIS TIME. CONFIDENCE REALLY DOES NOT
IMPROVE MUCH ON SUNDAY AS THERE IS UNCERTAINTY WITH REGARD TO HOW
COLD THE NEXT AIR MASS WILL BE. THE 00Z GFS AND 00Z ECMWF HAVE BOTH
TRENDED DOWNWARD AND WOULD RESULT IN HIGHS ONLY IN THE 20S ON SUNDAY
WHILE OUR FORECAST STILL IS INCORPORATING RECENT RUNS THAT WERE
WARMER AND IS CALLING FOR HIGHS IN THE 30S AND 40S.
BASICALLY...EXPECT FORECAST CHANGES IN THE COMING DAYS AS THE
UNCERTAINTY ISSUES GET IRONED OUT.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z MON NIGHT)
ISSUED AT 1159 PM CST SUN NOV 23 2014
OVERNIGHT: VARIABLE MULTI-LAYERED VFR CLOUDS MOSTLY BETWEEN 4-10K
FT. THERE IS A LOW PROBABILITY FOR A TEMPO MVFR CEILING BETWEEN
2500-3000 FT...ESPECIALLY AT GRI. CONFIDENCE IS NOT HIGH ENOUGH
TO INCLUDE IN THE TAFS. NW WINDS WILL BE HIGHLY VARIABLE IN SPEEDS
AND GUSTS. DURING TIMES WHEN WINDS DECREASE TO 10-15 KTS...SOME
LLWS IS PROBABLE. OTHERWISE...WINDS WILL GUST UP TO 35 KTS AT
TIMES. CONFIDENCE: MEDIUM
MON: MULTI-LAYERED VFR CIGS WILL DIMINISH WITH GRADUAL CLEARING
DURING THE MORNING HRS. NW WINDS WILL GUST UP TO 30 KTS.
CONFIDENCE: HIGH
MON EVE: VFR WITH CIRROSTRATUS CIGS INVADING. NW WINDS DIMINISH
AND SETTLE AROUND 10 KTS. CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
941 AM EST MON NOV 24 2014
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP EAST ACROSS THE REGION TODAY...BRINGING
SHOWERS ALONG WITH WINDY CONDITIONS. MUCH COLDER AIR WILL RUSH IN
BEHIND THE FRONT AND WILL LINGER FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FCST FOCUS TODAY REVOLVES AROUND STRONG WINDS AND CONVECTION THIS
MORNING. STRONG SFC LOW OVER THE NRN GREAT TO CONTINUE TO DEEPEN
AS IT TRACKS NE INTO SRN CANADA. 60 KT SWRLY LLJ PIVOTING THRU
THE AREA TODAY. RAP SHOWING BLYR CAPE OF 350 J/KG ACRS W CENTRAL
OHIO EARLY THIS MORNING. THIS MARGINAL INSTBY AHD OF SFC COLD FRONT
COMBINED WITH THE STRONG DYNAMICS HAS LED TO THE DEVELOPMENT OF A
BROKEN LINE OF CONVECTION. SOME OF THE STORMS WERE TRANSLATING
WINDS UP TO 45 KTS TO THE SFC. AN ISOLATED SVR WIND GUST OF 50 KTS
OR GREATER IN A STRONGER STORM CAN NOT BE RULED OUT.
THIS MARGINAL INSTBY WEAKENS AND PIVOTS TO THE NE THIS MORNING.
CURRENT FCST HAS GOOD HANDLE TAKING THIS CHANCE OF THUNDER EAST
AND THEN DIMINISHING.
SFC PRESSURE GRADIENT TIGHTENS WITH FROPA IN STRONG CAA THIS
MORNING INTO EARLY AFTERNOON. 50 TO 60 KT LOW LEVEL WILL GET
PULLED DOWN IN THE POST FRONTAL COLD ADVECTION. HAVE INCREASED
SUSTAINED WINDS AND BUMPED UP GUSTS INTO THE UPPER 40 KT RANGE.
EXPECT WINDS TO BE IN THE HIGH END WIND ADVISORY RANGE. THEREFORE...
HAVE KEPT CURRENT WIND ADVISORY HEADLINE GOING.
AFTER MORNING HIGHS IN IN STRONG LOW LEVEL CAA EXPECT EARLY HIGHS
WITH TEMPERATURES FALLING TO LATE AFTN READINGS RANGING FROM THE LOWER
40S NW TO THE LOWER 50S SE. HAVE ADJUSTED AFTERNOON TEMPS A LTL COLDER
IN THIS CAA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
BY EVENING THE PRESSURE GRADIENT WILL BEGIN TO WEAKEN AND THE
WINDS WILL GRADUALLY SLOW DOWN. LEFT OVER WRAP AROUND SHOWERS WILL
CHANGE OVER TO SNOW AS THICKNESSES FALL. THERE SHOULDNT BE ANY
APPRECIABLE ACCUMULATIONS.
BY TUESDAY MORNING SURFACE HIGH PRESSURE WILL BEGIN TO BUILD IN
AND SHOULD PROVIDE DRY WEATHER...ALTHOUGH A FEW SNOW SHOWERS MAY
LINGER OVER FAR NORTHERN LOCATIONS.
ON TUESDAY NIGHT...THE REGION WILL BE IN BETWEEN SYSTEMS...AS
ENERGY IN THE SRN STREAM AFFECTS THE EAST COAST AND ANOTHER S/W IS
DIGGING DOWN THROUGH THE PLAINS. MODELS ARE SHOWING A WIDE RANGE
IN THE STRENGTH AND PATH OF THIS SYSTEM. RIGHT NOW THE CONSENSUS
IS THAT THE REGION WILL REMAIN DRY ON WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FOCUS SHIFTS TO WEAKENING CLIPPER LOW DROPPING SE FROM THE UPPER
MS VLY WED AFTN THRU THE OHIO VALLEY WED NIGHT. NUMERICAL MODELS
HAVE BEEN FLIPPING BACK AND FORTH REGARDING HOW FAR SOUTH THIS
SYSTEM DIGS AND TIMING. LATEST DETERMINISTIC RUNS TAKING WEAK SFC
WAVE FROM CENTRAL IL LATE WED AFTN THRU THE TRI-STATE REGION WED
NIGHT. WILL BRING SNOW IN WED EVENING AND CONTINUE INTO THURSDAY.
SOME PCPN MIX WILL BE POSSIBLE ACRS THE SOUTHEAST. HIGHS ON
THURSDAY TO RANGE FROM THE LOWER/MID 30S NW TO LOWER 40 SE.
IN NORTHWEST FLOW AND CAA SOME LINGERING SNOW SHOWERS PSBL THURSDAY
NIGHT. SFC HIGH PRESSURE TO QUICKLY BUILD ACRS THE REGION EARLY ON
FRIDAY WITH A RETURN FLOW DEVELOPING BY AFTN. WAA PCPN TO DEVELOP
DURG THE AFTN WITH THE BULK OF PCPN STAYING TO OUR NORTH. WILL KEEP
AREA DRY THRU FRIDAY NIGHT. CONTD COLD TEMPERATURES WITH HIGHS ON
FRIDAY TO RANGING FROM THE LOWER 30S NW TO THE UPR 30S SE.
WAA PCPN LOOKS TO DEVELOP SAT AFTN BUT WITH MORE UNCERTAINTY
CREEPING INTO THE FCST REGARDING PLACEMENT/TIMING WILL LIMIT POPS TO
SLIGHT CHANCE OF SHOWERS. THE RAIN COULD MIX OR CHANGE TO SNOW SAT
NIGHT. GFS SOLN APPEARS TOO QUICK WITH COLD FRONTAL PASSAGE. WILL
TREND SOLN CLOSER TO SLOWER ECMWF WITH FRONT HOLDING OFF UNTIL EARLY
MONDAY. IN WAA SECTOR CHANCE OF SHOWERS WILL CONTINUE SUNDAY.
TEMPERATURES WILL MODERATE WITH HIGHS ON SUNDAY FROM UPPER 30S
NORTHWEST TO THE UPPER 40S SOUTH.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
CONVECTIVE BAND OF SHOWERS OVER CENTRAL INDIANA MAY SKIRT KDAY FOR
A PERIOD OF TIME THIS MORNING SO CHANGED VCSH TO VCTS AND HAVE AN
HOUR OF TEMPO TS HERE. REMAINING TAF SITES WILL LIKELY NOT GET
INTO THE DEEP CONVECTION AS THIS AREA IS SLATED TO MOVE NORTHEAST
FROM DAYTON AREA AS THE LARGE SCALE FORCING LIFTS NORTHEAST WITH
THE EJECTING LOW PRESSURE CENTER.
MVFR CIGS WILL BE PREVALENT IN THE 2-3KFT RANGE INTO TONIGHT WITH
SOME BREAKUP NOTED AWAY FROM KDAY AFTER ABOUT 5 OR 6. A TRAILING
EDGE OF THE SURFACE TROUGH AND CONTINUED PLACEMENT OF A VORT AXIS
AT H5 OVER THE AREA WOULD HAVE LOW STRATOCU CONTINUE AT KDAY BUT
NOT NEARLY AS LIKELY DURING THE OVERNIGHT HOURS ELSEWHERE. WINDS
WILL ALSO EXHIBIT A MARKED DECREASE TONIGHT.
OUTLOOK...MVFR CIGS POSSIBLE INTO TUESDAY. MVFR CIGS/VSBYS POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR OHZ026-034-035-
042>046-051>056-060>065-070>074-077>082-088.
KY...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR KYZ089>100.
IN...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ050-058-059-
066-073>075-080.
&&
$$
SYNOPSIS...CONIGLIO/SITES
NEAR TERM...AR/SITES
SHORT TERM...SITES
LONG TERM...AR
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
548 AM CST MON NOV 24 2014
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...COLD FRONT IS CURRENTLY SLICING THROUGH SOUTHERN
CAMERON COUNTY WITH DENSE FOG REMAINING OVER THE BRO TERMINAL
CURRENTLY WITH CONDITIONS SLOWLY IMPROVING AT THE HRL TERMINAL.
FRONT SHOULD PASS THROUGH THE BRO TERMINAL AROUND 12Z WITH
VIS/CIGS SLOWLY IMPROVING THROUGH 13Z. VFR SHOULD RETURN TO
BRO/HRL TERMINALS BY 1330Z. GUSTY NORTHERLY WINDS EXPECTED BEHIND
THE FRONT AND THROUGH MOST OF THE DAY WITH DECREASING WINDS
TOWARDS SUNSET. SHOULD EXPERIENCE PLENTY OF HIGH LEVEL CLOUDS BUT
NOT MUCH IN THE WAY OF LOW/MID CLOUDS AS THE ATMOSPHERE SHOULD
REMAIN DRY IN THESE LEVELS.
&&
.PREV DISCUSSION... /ISSUED 349 AM CST MON NOV 24 2014/
SHORT TERM /NOW THROUGH TUESDAY/...EXPANDED THE DENSE FOG
ADVISORY TO COVER ALL THE COASTAL AREAS AND GULF WATERS 0-20NM
EAST OF THE COASTLINE. DENSE MARINE FOG ADVECTED IN THROUGH THE
OVERNIGHT HOURS AND HAS CONTINUED ITS N-NW PROGRESSION EVEN
REACHING EASTERN HIDALGO COUNTY. DID ALSO EXTEND THE TIMING
THROUGH 12Z BASED ON THE HRRR NOT BRINGING FROPA THROUGH THE LOWER
VALLEY TILL 12Z AND STRONGER WINDS NOT UNTIL 14Z. SPEAKING OF THE
FRONT...11-3.9 MICRON SHOWS THE FRONT CLEARLY THROUGH MIDDLE TEXAS
COASTAL WATERS AS A FINE LINE OF LOWER STRATUS WITH KRKP AND KCRP
WIND DIRECTIONS SWITCHING TO THE NORTHWEST. EXTRAPOLATING USING
CURRENT SPEED PLACES THE FRONT IN THE LOWER VALLEY BY 12Z MATCHING
UP WITH THE HRRR.
NORTH WINDS WILL PICK UP AFTER THE FRONTAL PASSAGE WITH BREEZY
CONDITIONS THROUGH THE MORNING HOURS WITH WINDS DIMINISHING INTO THE
AFTERNOON HOURS. ALONG THE COAST THE WINDS WILL STAY UP A LITTLE
LONGER THAN MORE INLAND AREAS. WILL BE A NICE AND COOL DAY TODAY
WITH A SOME PASSING HIGH CLOUDS FROM TIME TO TIME. HIGHS WILL BE IN
THE UPPER 60S IN THE RANCHLANDS TO LOWER 70S IN THE VALLEY. SFC HIGH
PRESSURE BUILDS INTO CENTRAL TEXAS OVERNIGHT THEN SINK SOUTHWARDS ON
TUESDAY. WINDS WILL BE FAIRLY LIGHT TONIGHT INTO TUESDAY AND WILL
KEEP SOME CLOUDS CLOUDS AROUND WITH SOUTHWESTERLY FLOW IN THE
MID/UPPER LEVELS UNTIL THE 500MB TROUGH UPSTREAM SWINGS THROUGH
TUESDAY AFTERNOON. MET/MAV TEMPERATURES TONIGHT CAME IN COOLER SO
TRENDED OUR TEMPERATURES DOWNWARD A DEGREE OR TWO ESPECIALLY IN
OUTLYING AREAS. TUESDAY HIGHS ARE A REPEAT OF TODAY.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...EXTENDED PERIOD
CONTINUES TO LOOK PRETTY QUIET AND LITTLE CHANGE WAS MADE TO THE
PRIOR FORECAST. ALL IN ALL A MILD AND FAIRLY DRY WEEK IS IN THE
WORKS. SHORTWAVE TROUGH WILL BE EXITING THE REGION TUESDAY NIGHT
WITH FLOW ALOFT VEERING TO THE NORTHWEST. THE NORTHWEST FLOW WILL
BRING DRY AIR OVER THE REGION...RESULTING IN MOSTLY CLEAR SKIES
TUESDAY NIGHT INTO THURSDAY. TUESDAY NIGHT WILL BE THE COLDEST OF THE
WEEK AS CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPERATURES TO FALL
INTO THE LOWER AND MID 40S. BELOW NORMAL TEMPERATURES WILL CONTINUE
WEDNESDAY THROUGH THURSDAY...WITH HIGHS IN THE LOWER 70S AND LOWS IN
THE MID TO UPPER 40S NORTH AND UPPER 40S TO LOWER 50S SOUTH.
TEMPERATURES AND CLOUD COVER BEGIN TO INCREASE ON FRIDAY AS MODERATE
SOUTHEASTERLY FLOW RETURNS. A 500 MB TROUGH/CUTOFF LOW DEVELOPS OVER
NORTHERN MEXICO ON THURSDAY AND SLOWLY NUDGES EAST THROUGH THE
WEEKEND. THE WEAK TROUGH COMBINED WITH THE INCREASED MOISTURE COULD
RESULT IN A FEW STREAMER SHOWERS OVER THE COASTAL WATERS ON SUNDAY.
MARINE...
NOW THROUGH TUESDAY...A FRONT WILL SWEEP ACROSS THE AREA EARLY
THIS MORNING WITH WINDS SWITCHING TO THE NORTH IN ITS WAKE. STRONG
NORTH WINDS WILL ROUGHEN SEAS AND A SMALL CRAFT ADVISORY HAS BEEN
ISSUED FOR THE GULF OF MEXICO WATERS OF THE LOWER TEXAS COAST
THROUGH MONDAY AFTERNOON. ROUGH SEAS WILL BECOME MORE MODERATE
MONDAY NIGHT INTO AS WIND SPEEDS DECREASE. HOWEVER...A SECONDARY
SURGE OF STRONGER WINDS LOOK TO INVADE AT LEAST THE 20-60NM WATERS
TUESDAY AROUND THE DEPARTING SYSTEM WHICH SMALL CRAFT ADVISORIES
MAY BE NEEDED FOR THE FAR OFFSHORE WATERS FOR SEAS RISING BACK UP
TO AROUND 7 FEET.
TUESDAY NIGHT THROUGH FRIDAY...NORTH WINDS TUESDAY EVENING WILL
BEGIN TO DIMINISH AND SEAS WILL BEGIN TO SUBSIDE AS THE PRESSURE
GRADIENT WEAKENS. SMALL CRAFT ADVISORIES MAY NEEDED TUESDAY NIGHT
FOR THE FAR OFFSHORE WATERS FOR SEAS OF 7 FEET. SEAS WILL CONTINUE
TO SUBSIDE THROUGH THE DAY WEDNESDAY. LIGHT TO MODERATE SOUTHEAST
WINDS AND LOW SEAS WILL PREVAIL THURSDAY AND FRIDAY.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
TXZ254>257.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL NOON CST TODAY FOR GMZ130-
132-135.
DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR GMZ130-
132-150.
SMALL CRAFT ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR GMZ150-
155-170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
514 AM CST MON NOV 24 2014
.DISCUSSION...SEE 12Z AVIATION DISCUSSION.
&&
.AVIATION...VFR. GUSTY NORTH WINDS EASTERN TAFS TODAY WILL
DIMINISH LATER THIS AFTERNOON. MID/HIGH CLOUD COVER IS EXPECTED
OVERNIGHT WITH UPPER LEVEL DISTURBANCE. WINDS MAY PICK UP A TAD
WITH IT TOO...BUT NOTHING ABOVE 11 KNOTS EXPECTED ON AVERAGE.
&&
.PREV DISCUSSION... /ISSUED 320 AM CST MON NOV 24 2014/
SHORT TERM (TODAY THROUGH TUESDAY)...COOLER WEATHER ON THE WAY AS
THE COLD FRONT MOVES THROUGH SOUTH TEXAS EARLY THIS MORNING. TOO DRY
NEAR THE SURFACE FOR SHOWERS...AND THAT DRIER AIR IN THE LOWER AND
MID LEVELS REMAINS (MOISTENS UP 700MB AND ABOVE TONIGHT). PRETTY
POTENT UPPER TROUGH AND JET IMPACT AREA OVERNIGHT AND TUESDAY
MORNING...AND MOISTURE 700MB AND ABOVE DUE TO LIFT MAY PRODUCE A
SPRINKLE OR TWO OVER EXTREME EASTERN AREAS AND COASTAL WATERS
(MAINLY CLOUDS THOUGH). HOWEVER...SINCE SPRINKLES WILL NOT MENTION.
WILL GO WITH PARTLY TO MOSTLY CLOUDY SKIES TUESDAY MORNING AS THERE
SHOULD BE SUFFICIENT MID AND HIGH CLOUDS TO PRECLUDE SOME SUN AT
LEAST UNTIL THE AFTERNOON WHEN AREA GETS ON THE SUBSIDENCE SIDE OF
UPPER SYSTEM. AM GOING TO GO ON THE COOLER SIDE OF GUIDANCE FOR
TEMPERATURES TODAY AND TUESDAY...BUT MORE ON THE WARM SIDE FOR
TONIGHT AS MID AND HIGH CLOUDS WILL PREVENT TEMPERATURES FROM
FALLING TOO MUCH. WIND FORECAST GENERALLY A BLEND OF RUC13 AND
NAM12 FOR THE MORNING...THEN A BLEND OF THE NAM AND MOS FOR THE
AFTERNOON THROUGH TUESDAY.
MARINE (TODAY THROUGH TUESDAY)...WILL ADJUST SCA TO KEEP THE
NEARSHORE IN A BIT LONGER (TIL ABOUT NOON)...AND THE OFFSHORE TIL
ABOUT 5 PM...GIVEN WIND AND WAVE FORECAST. SCA CONDITIONS WILL
LIKELY DEVELOP AGAIN LATE TONIGHT OR TUESDAY. HOWEVER...WILL HOLD
OFF ON HAVING AN SCA FOR THAT AT THIS TIME SINCE 3RD PERIOD AND
WINDS AND WAVES WILL TAPER OFF SOME TONIGHT (AND BORDERLINE SCA AT
THAT). WILL LET NEXT SHIFT TAKE A PEEK AT THIS.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...GENERALLY BENIGN
FORECAST THROUGH THE LONG TERM PERIOD...BUT A FEW DETAILS TO
CONSIDER IN THE OVERALL PATTERN. UPPER LEVEL DISTURBANCE PUSHING
EAST OF THE AREA AT ONSET OF LONG TERM PERIOD. SHOULD BE CLEARING
OUT QUICKLY TUESDAY NIGHT...IF NOT ALREADY CLEARED LATE TUESDAY
AFTERNOON. VERY DRY AIR FILTERS IN WITH REINFORCING RIDGE WITH PWATS
WELL BELOW HALF INCH OVER MUCH OF THE AREA. A COUPLE OF WEAK
SHORTWAVES NOTED IN THE UPPER LEVEL PATTERN FRI EVENING AND SUNDAY.
CONFIDENT THAT AIR WILL STILL BE DRY FOR FRIDAY EVENING SHORT
WAVE...BUT SUNDAY WEAK DISTURBANCE COULD HAVE THE POTENTIAL FOR SOME
POPS AS A SOUTHERLY FLOW WILL HAVE DEVELOPED LATE IN THE WEEK. AT
THIS TIME WITH A MAINLY SOUTHERLY FLOW RATHER THAN SOUTHEAST...NOT
THINKING TOO HIGHLY OF SLIGHT CHANCE POPS SOME MODELS ARE
INDICATING. WILL KEEP THE FORECAST DRY AT THIS TIME.
TEMPS FOR THE WEEK SHOULD BE WAVERING AROUND NORMAL FOR HIGHS.
SLIGHTLY BELOW NORMAL LOWS ARE LIKELY EARLY IN THE WEEK WITH HIGH
PRESSURE AND CLEAR SKIES...BUT WILL WARM TO ABOVE NORMAL BY THE
WEEKEND AS MOISTURE GRADUALLY WORKS ITS WAY BACK IN.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 67 45 69 44 70 / 0 0 0 0 0
VICTORIA 65 41 64 41 70 / 0 10 10 0 0
LAREDO 68 48 69 41 73 / 0 0 0 0 0
ALICE 67 43 70 41 72 / 0 0 0 0 0
ROCKPORT 67 48 65 52 69 / 0 10 10 0 0
COTULLA 66 42 67 39 72 / 0 0 0 0 0
KINGSVILLE 68 44 69 42 72 / 0 0 0 0 0
NAVY CORPUS 67 52 68 50 69 / 0 10 10 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS
OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1207 PM CST MON NOV 24 2014
.UPDATE...1109 AM CST
NO CHANGES TO GOING WINTER WEATHER ADVISORY. DUAL POL HAS SHOWN
PROGRESSION OF RAIN/SNOW LINE NICELY THIS MORNING AS COLD AIR HAS
WRAPPED IN FROM SOUTHWEST. HAVE OBSERVED SLUSHY ACCUMULATION ON
PAVEMENT HERE AT OFFICE AND ALSO RECEIVING SIMILAR REPORTS VIA
SPOTTERS AND SOCIAL MEDIA. AS SECONDARY DEFORMATION AXIS LIFTS
NORTH...CONDITIONS WILL LIKELY IMPROVE FOR SOUTHWEST CHI METRO TO
DOWNTOWN WITHIN NEXT ONE TO TWO HOURS. MEANWHILE...WORST OF
CONDITIONS WILL SETTLE INTO FAR NORTHERN IL...INCLUDING NORTH AND
NORTHWEST CHICAGO METRO AND ROCKFORD AREA. GIVEN VISIBILITY IN
HEAVIEST PORTION OF BAND DOWN AROUND 1/4 MILES AS OF 11AM...WIND
AND SNOW ACCUMS ON ROADWAY WILL RESULT IN HAZARDOUS TRAVEL AS
TEMPERATURES CONTINUE TO FALL TO AND BELOW FREEZING. IT APPEARS
SOME PORTIONS OF NORTHWEST/NORTH CENTRAL IL HAVE ALREADY RECEIVED
ONE INCH OR SO OF ACCUMULATION...SO STILL LOOKING AT ACCUMULATIONS
GENERALLY IN THE 2 TO 4 INCH RANGE IN THE ADVISORY AREA.
STRONG WESTERLY WINDS ARE AN ISSUE AREA WIDE...BUT PARTICULARLY IN
SOUTH/SOUTHEAST CWA WHERE MAX 3 HR PRESSURE RISES ~8MB ARE
FOCUSING. EXPECT WIND GUSTS TO 40 TO 45 MPH THROUGH EARLY TO MID
AFTERNOON. WILL HOLD OFF ON ISSUING AN ADVISORY...AS EXPECTING
ONLY SPORADIC GUSTS TO 45 MPH.
RC
&&
.SHORT TERM...
313 AM CST
THROUGH TONIGHT...
COMPLEX STORM SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH
TONIGHT WITH A TRANSITION FROM MILD AND RAINY TOWARD COLD AND
POTENTIALLY SNOWY LIKELY TO TAKE PLACE LATER THIS MORNING.
DEEPENING SURFACE LOW FROM CENTRAL LAKE MICHIGAN EAST INTO LOWER
MICHIGAN WILL CONTINUE TO LIFT NORTHEAST TODAY AND DEEPEN FURTHER.
COLD FRONT TRAILING THIS BROAD LOW IS CROSSING THE MISSISSIPPI RIVER
NOW AND WILL STEADILY MARCH EAST ACROSS OUR CWA THIS MORNING
RESULTING IN STEADILY FALLING TEMPERATURES FROM THE POINT OF FROPA
THROUGH TONIGHT.
THE PRIMARY DEFORMATION ZONE WITH THIS SYSTEM IS MOVING OUT OF THE
AREA AT THIS TIME...HOWEVER THERE ARE A COUPLE ADDITIONAL VORTICITY
MAXIMA UPSTREAM. THE FIRST WELL DEFINED VORT IS NEAR STL WITH A SLUG
OF RAIN AND EVEN A COUPLE OF ISOLATED THUNDERSTORMS. THIS VORT IS
PROGGED TO SHEAR ENE CENTRAL ILLINOIS INTO NORTHERN OHIO TODAY. A
SECOND VORT MAX IS LOCATED UPSTREAM OVER KANSAS AND PIVOTING AROUND
THE BASE OF THE TROUGH AND EVENTUALLY PHASE WITH THE SHEARING OUT
VORT OVER INDIANA AND OHIO THIS AFTERNOON. AS THIS PROCESS TAKES
PLACE...THE RAIN ASSOCIATED WITH VORT ONE WILL SPREAD NORTHEAST
ACROSS OUR CWA THIS MORNING. AS THE SECOND VORT BEGINS TO PHASE WITH
THE FIRST A ZONE OF MID-LEVEL FRONTOGENESIS WILL DEVELOP ACROSS THE
LOWER LAKES THIS AFTERNOON AND ALLOW PRECIP WITH FIRST VORT TO
MAINTAIN ITSELF AND EVEN DEVELOP UPSTREAM (WESTWARD) INTO FAR
NORTHERN ILLINOIS AND ESPECIALLY INTO SOUTHERN WISCONSIN.
GUIDANCE HAS ALL SHIFTED NORTHWARD WITH THIS PROCESS COMPARED WITH
EARLIER RUNS AND ITS DIFFICULT TO FIND ANY MODEL THAT STILL SUPPORTS
THE 3-5" FORECAST TOTALS WE HAVE GOING IN THE ADVISORY AREA. AM VERY
LEARY ABOUT OVER CORRECTING THINGS SO DID A LOT OF FUZZY MATH AND
FUDGING OF GRIDS TO MAINTAIN AMOUNTS IN THE 2-5" RANGE IN THE
ADVISORY AREA...THOUGH SUSPECT MAJORITY OF THE ADVISORY AREA WILL
END UP WITH TOTALS ON THE BOTTOM END OF THE RANGE. SOUTH OF THE
ADVISORY AREA STILL THINK THERE COULD BE A CHANGEOVER TO SNOW BEFORE
THE DEFORMATION AXIS SHIFTS NORTHWARD AND PRECIP TAPER OFF THIS
AFTERNOON. IF CHANGE OVER ISNT FAST ENOUGH THEN COULD END UP WITH
JUST A TRACE OF SNOW...THOUGH FASTER CHANGE OVER AND BRIEF HEAVIER
INTENSITY COULD SUPPORT AMOUNTS AROUND AN INCH. BEFORE THE ENTIRE
CHANNELED VORT MAX TRANSLATES NORTHEAST OUT OF THE AREA COULD SEE
WESTERN EXTENT OF THE AXIS PIVOT BACK SOUTHWARD A BIT THIS AFTERNOON
INTO OUR NORTHWEST CWA...AND THIS WOULD BE NECESSARY TO GET FORECAST
AMOUNTS.
STRONG WESTERLY WINDS DEVELOP THIS MORNING BEHIND THE COLD FRONT AND
WILL CONTINUE INTO THIS EVENING. THE WINDS WILL WHIP AROUND ANY
FALLING SNOW LEADING TO GREATER REDUCTIONS IN VSBY. IN ADDITION...AS
TEMPS CONTINUE TO FALL FARTHER BELOW FREEZING LATER THIS AFTERNOON
SOME OF THE SNOW ON THE GROUND COULD GET BLOWN AROUND AS SNOW LIKELY
BECOMES MORE POWDERY IN NATURE.
IZZI
&&
.LONG TERM...
313 AM CST
TUESDAY ONWARD...
EXPANSIVE STRATUS DECK LIKELY TO BECOME ESTABLISHED OVER THE AREA
TUESDAY AND WHILE LOW LEVEL FLOW WILL BEGIN TO TRANSITION TO
ANTICYCLONIC TUESDAY AFTERNOON AHEAD OF THE NEXT CLIPPER...NOT SURE
HOW MUCH CLEARING THERE WILL BE AS DRY AIR ADVECTION WILL BE WEAK
WITH DIMINISHING FLOW. IN ADDITION...SUBSIDENCE WILL FURTHER SHARPEN
THE INVERSION CLOUDS ARE TRAPPED BENEATH SO HAVE INCREASED SKY COVER
TUESDAY AND NO LONGER SHOW ANY SUBSTANTIAL CLEARING BEFORE THE MID
WEEK CLIPPER COMES ZIPPING DOWN. GIVEN THE ANTICIPATED CLOUD COVER
HAVE GONE WITH SMALLER DIURNAL TEMP SWINGS WITH CLOUDS PROBABLY
KEEPING TEMPS UP A SMIDGE OVER GUIDANCE AT NIGHT AND A BIT LOWER
DURING THE DAY.
SPEAKING OF THE MID WEEK CLIPPER...GUIDANCE REMAINS INCONSISTENT RUN
TO RUN AND MODEL TO MODEL. THERE HAS BEEN A DISTINCT SOUTHWARD SHIFT
IN GUIDANCE WITH THIS SYSTEM WHICH IF IT WERE TO PAN OUT WOULD PLACE
THE ACCUMULATING SNOW OVER MAINLY OUR SOUTHERN CWA AND POTENTIALLY
BYPASS NORTHERN CWA. THIS CLIPPER IS ORIGINATING AS A PIECE OF
ENERGY BREAKING OFF AN UPPER LOW NEAR THE NORTHERN ALEUTIANS AND
SEEING AS IT HADNT EVEN BROKEN OFF THE LOW AND BEEN WELL SAMPLED YET
AM NOT READY TO THROW MY EGGS IN THE MORE SOUTHERLY TRACK BASKET
JUST YET. BY 12Z WEDNESDAY THE GFS ENSEMBLES HAVE SURFACE LOW
POSITIONS RANGING FROM WESTERN WISCONSIN TO NORTHWEST ARKANSAS...SO
NEEDLESS TO SAY FURTHER CHANGES ARE LIKELY THE NEXT SEVERAL GUIDANCE
CYCLES WITH THIS SYSTEM AND IT IS TOO SOON TO WRITE OFF THE THREAT
OF LIGHT ACCUMULATING SNOW ANYWHERE IN OUR CWA.
ANOTHER INTERESTING TWIST IN THE LATEST MEDIUM RANGE GUIDANCE IS
LESS OF A COLD INTRUSION IN THE WAKE OF THIS CLIPPER FOLLOWED BY A
RAPID TRANSITION TO ZONAL FLOW BY FRIDAY AND INTO THE WEEKEND.
GFS...GEM...AND ECMWF ALL TRACK A SFC LOW OF VARYING STRENGTHS
ACROSS THE UPPER GREAT LAKES SATURDAY PLACING OUR AREA IN WHAT WOULD
BE A VERY MILD SOUTHERLY FLOW. THE 00Z ECMWF THERMAL FIELDS WOULD
SUPPORT HIGHS WELL INTO THE 50S BY SATURDAY...BUT OBVIOUSLY DIDN`T
MAKE THAT DRASTIC OF A CHANGE TO THE GOING FORECAST BUT IF MODELS
REMAIN CONSISTENT WITH THIS LATEST TREND THEN A MILD WEEKEND COULD
BE ON TAP FOR THE REGION.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* PATCHY IFR CIGS SLOWLY LIFTING TO LOW END MVFR ARND 20Z.
* MVFR VSBYS WITH LGT SNOW...LIFTING TO VFR AS SNOW BEGINS TO
DIMINISH TO FLURRIES AFT 00Z.
* WEST WINDS 20-24KT WITH GUSTS 30-35KT.
BEACHLER
//DISCUSSION...UPDATED 18Z...
RAIN QUICKLY CHANGED OVER TO ALL SNOW LATE THIS MORNING...WITH A
FEW BANDS OF MODERATE SNOW REDUCING VSBYS TO 1/2SM TEMPORARILY AT
ORD/MDW/RFD. BASED ON RADAR TRENDS THE HEAVIEST PRECIP WAS QUICKLY
LIFTING NORTHEAST OF ORD/MDW...AND SHUD ALLOW VSBYS TO RETURN TO
ABOVE 1SM BY 19Z. CIGS WILL REMAIN ARND IFR CONDS...BUT SHUD
IMPROVE TO LOW END MVFR CONDS SHORTLY AFT THE HEAVIER SNOW ENDS.
THEN MVFR CIGS WILL LIKELY PERSIST THRU THIS EVE UNTIL MUCH DRIER
AIR ARRIVES AND CIGS BEGIN TO SCATTER OUT TO BKN DECK
OVERNIGHT/EARLY TUE. WINDS WILL CONTINUE TO BE GUSTY FROM THE
WEST. SUSTAINED WINDS HAVE REMAINED ARND 20-24KT WITH GUSTS
APPROACHING 34-38KT AT TIMES.
AS THE PRESSURE BEGINS TO INCREASE TONIGHT...WINDS WILL STEADILY
DIMINISH BUT REMAIN WESTERLY THROUGH THE OVERNIGHT HOURS. CURRENT
INDICATIONS ARE THAT SCATTERED FLURRIES WILL CONTINUE UNTIL ARND
MIDNIGHT.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN THE VSBYS IMPROVING ABOVE 1SM ARND 19Z.
* MEDIUM CONFIDENCE IN TIMING OF CIGS LIFTING FROM LOW END MVFR TO
VFR CONDS OVERNIGHT.
* HIGH CONFIDENCE IN THE STEADIER HEAVIER SNOW ENDING BEFORE
20Z...WITH MEDIUM/HIGH CONFIDENCE IN THE ACCUMULATING SNOW
ENDING BY 23Z.
* LOW CONFIDENCE IN PRECISE ENDING TIME OF LGT SNOW/FLURRIES ARND
6Z.
* HIGH CONFIDENCE IN WIND DIR/SPEED/GUSTS FORECAST. MEDIUM/HIGH
CONFIDENCE IN TIMING OF GUSTS ENDING.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...SCHC SNOW. OTHERWISE VFR. SOUTHEAST TO EAST WINDS.
THURSDAY...A FEW FLURRIES POSSIBLE...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST-SOUTHWEST WINDS.
SUNDAY...VFR. NORTH WINDS.
KMD
&&
.MARINE...
154 AM CST
DEEPENING LOW PRESSURE IS PASSING OVER THE LAKE EARLY THIS MORNING
BRINGING A LULL IN WINDS AND WAVES. THE LOW WILL CONTINUE NORTHEAST
INTO SOUTHWEST QUEBEC LATER THIS AFTERNOON THEN REMAIN STEADY AS IT
PUSHES OFFSHORE OVER NOVA SCOTIA. A STRONG SOUTHWEST TO NORTHEAST
ORIENTED PRESSURE GRADIENT WILL REACH THE SOUTH TIP OF THE LAKE BY
15Z...THEN SPREAD OVER THE REMAINDER OF THE LAKE IN THE AFTERNOON.
GALES LOOK SOLID FOR THE SOUTH HALF OF THE THE LAKE...BUT DUE TO A
WEAKENING PRESSURE GRADIENT WITH TIME TODAY AND A MODEST HIGH
BUILDING INTO THE CANADIAN PRARIES AND UPPER MIDWEST...FEEL THAT
WINDS WILL LIKELY PEAK JUST UNDER GALES FOR THE NORTH HALF. A FEW
GALE FORCE GUSTS ARE POSSIBLE...ESPECIALLY LATE AFTERNOON/EARLY
EVENING.
WEAK HIGH PRESSSURE EXTENDING FROM THE NORTH TIP OF LAKE SUPERIOR TO
THE OHIO VALLEY PASSES OVER THE LAKE TUESDAY AFTERNOON. ANOTHER
WEAKENING LOW EMERGING FROM THE CANADIAN ROCKIES WILL PASS JUST
SOUTH OF THE TIP OF LAKE MICHIGAN WITH THE REMNANT INVERTED TROUGH
CLEARING THE LAKE BY THURSDAY MORNING. THIS WILL BE FOLLOWED BY WEAK
HIGH PRESSSURE FOR A FEW DAYS.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012 UNTIL MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1148 AM CST Mon Nov 24 2014
.UPDATE...
ISSUED AT 1045 AM CST MON NOV 24 2014
Updated the forecast to adjust winds and precipitation chances
today. Kept the wind advisory going into the afternoon for eastern
IL but will likely be able to cancel early as very strong and
still deepening 977 mb low pressure over eastern Ontario pulls
ne away from the Great Lakes region. Still getting some sustained
winds 25 to 30 mph with gusts of 35 to 45 mph in our ne counties
late this morning. Light snow north of I-72 is starting to
diminish and expect this trend to continue into this afternoon as
light snow chances diminish to slight chance and flurries. Highs
have already been reached early this morning with current temps
ranging from 30F at Galesburg to 45F at Mount Carmel airport.
Temps to mostly be in the low to mid 30s today and settle into the
upper 30s to near 40F in southeast IL this afternoon.
&&
.SHORT TERM...(Today)
ISSUED AT 329 AM CST MON NOV 24 2014
Several short-term forecast challenges today, as a potent storm
system tracks through the area. Of particular concern are
strong/gusty winds behind a departing frontal boundary and the
potential for a light accumulation of snow across the W/NW KILX
CWA.
08z/2am surface analysis shows cold front extending from southern
Lake Michigan to the Ozarks. An area of low pressure along the
boundary over southeast Missouri is currently enhancing lift and
triggering a few thunderstorms along/south of the I-70 corridor.
This activity will push E/NE into Indiana by dawn. Further west, an
area of precipitation along/behind the front will continue to lift
northward, mainly impacting locations along/west of I-57. As colder
air streams into the region, the rain will gradually mix with and
change to snow by mid-morning. Based on upstream temp falls across
Iowa/Missouri, readings will drop into the middle 30s across the
Illinois River Valley by 12z/6am, then further east to the I-55
corridor by 15z/9am. At the same time, the precip will be pulling
northeastward out of the area, so there appears to be only a narrow
window of opportunity for snow across the W/NW. Will carry likely
to categorical PoPs across the western half of the CWA for rain
changing to snow this morning, with lower rain chances further east
and south across the remainder of the region. Main area of snow
will lift into northern Illinois by midday, with only a few
flurries/snow-showers persisting along/north of I-72 this
afternoon. Total snow accumulation will be limited due to light QPF
and marginally favorable temps. Around 1 inch is expected
along/north of a Canton to Bloomington-Normal line, with trace
amounts as far southeast as a Litchfield to Champaign-Urbana
line.
Other big story today will be the strong winds behind the cold
front. Upstream obs have already shown gusts as high as 30-40mph
and think these will translate eastward across central Illinois this
morning. Main question will be whether there may be a corridor of
enhanced winds approaching Wind Advisory criteria across the E/SE
CWA. Current MSAS analysis shows max 3-hour pressure rises of 6mb
over southern Missouri/northern Arkansas. Both the 00z and 06z runs
of the NAM have shown these rises tracking northeastward and
increasing to around 9mb over southeast Illinois later this
morning. HRRR 10m wind gust graphic also indicates increasing winds
ahead of the pressure change couplet as it moves across the
southeast CWA between 12z and 18z. Given this consistent signal,
think it is prudent to issue a Wind Advisory for locations
along/southeast of a Champaign to Taylorville line. While all of
central Illinois will experience wind gusts of 30 to 35 mph, this
particular area may see higher gusts exceeding 40 mph.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 329 AM CST MON NOV 24 2014
Low pressure will lift into the Great Lakes tonight, taking the bulk
of the precip with it. Wrap around moisture may brush across the
northern CWA, so have included scattered flurries in the forecast
this evening along/north of I-72. Forecast soundings indicate low
clouds will persist tonight and may even be slow to clear on
Tuesday, despite approaching surface ridge axis. Have therefore
slowed the clearing trend, with cloudy skies tonight followed by
decreasing clouds on Tuesday.
Fast-moving clipper system is still on target for mid-week, with
model consensus bringing the system across central Illinois on
Wednesday. This particular track is slightly further south than
previously advertised, so WAA ahead of the wave may not be quite as
pronounced as once thought. Even still, high temperatures will
climb well into the 30s and into the lower 40s across the southeast
CWA. End result will be light snow across the far north from the
Peoria area northward, a mix of light rain/snow across much of the
area, and mainly rain south of I-70. Due to the limited period of
light precip and warm temps, snow accumulations will be minimal.
Once this system passes to the east, another shot of cold air will
arrive for Thursday. After that, signs are still pointing to warmer
conditions by the end of the week, with temps climbing well into the
40s by Saturday. Both the GFS and ECMWF indicate a cold front will
drop through the region Saturday night, so temps will likely drop
back into the upper 30s/lower 40s by Sunday/Monday. Moisture will
be limited, so will maintain a dry FROPA at this time.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1150 AM CST MON NOV 24 2014
Light snow showers and flurries will occur into mid afternoon over
mainly northern TAF sites of PIA and BMI where MVFR vsbys 3-5 miles
to occur at times. Have just flurries further south along I-72 TAF
sites this afternoon with vsbys generally above 5 miles. MVFR overcast
ceilings to continue through tonight with BMI as low as 900 ft at
midday. Strong and deeping 976 mb low pressure near the
Ontario/Quebec province line continue to pull northeast away from
the Great Lakes region as it lifts across Quebec but still have
cyclonic flow over IL through tonight. This will likely keep
broken to overcast low clouds over central IL through tonight and
have ceilings lifting up to VFR during mid/late Tue morning.
Strong WSW winds 17-25 kts and gusts of 28-35 kts early this
afternoon to gradually diminish later this afternoon and evening
reaching speeds of 10-15 kts after 02Z with west winds around 10
kts overnight into Tue morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 6 PM CST this evening FOR ILZ044>046-052>057-
061>063-066>068-071>073.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1109 AM CST MON NOV 24 2014
.UPDATE...
1109 AM CST
NO CHANGES TO GOING WINTER WEATHER ADVISORY. DUAL POL HAS SHOWN
PROGRESSION OF RAIN/SNOW LINE NICELY THIS MORNING AS COLD AIR HAS
WRAPPED IN FROM SOUTHWEST. HAVE OBSERVED SLUSHY ACCUMULATION ON
PAVEMENT HERE AT OFFICE AND ALSO RECEIVING SIMILAR REPORTS VIA
SPOTTERS AND SOCIAL MEDIA. AS SECONDARY DEFORMATION AXIS LIFTS
NORTH...CONDITIONS WILL LIKELY IMPROVE FOR SOUTHWEST CHI METRO TO
DOWNTOWN WITHIN NEXT ONE TO TWO HOURS. MEANWHILE...WORST OF
CONDITIONS WILL SETTLE INTO FAR NORTHERN IL...INCLUDING NORTH AND
NORTHWEST CHICAGO METRO AND ROCKFORD AREA. GIVEN VISIBILITY IN
HEAVIEST PORTION OF BAND DOWN AROUND 1/4 MILES AS OF 11AM...WIND
AND SNOW ACCUMS ON ROADWAY WILL RESULT IN HAZARDOUS TRAVEL AS
TEMPERATURES CONTINUE TO FALL TO AND BELOW FREEZING. IT APPEARS
SOME PORTIONS OF NORTHWEST/NORTH CENTRAL IL HAVE ALREADY RECEIVED
ONE INCH OR SO OF ACCUMULATION...SO STILL LOOKING AT ACCUMULATIONS
GENERALLY IN THE 2 TO 4 INCH RANGE IN THE ADVISORY AREA.
STRONG WESTERLY WINDS ARE AN ISSUE AREA WIDE...BUT PARTICULARLY IN
SOUTH/SOUTHEAST CWA WHERE MAX 3 HR PRESSURE RISES ~8MB ARE
FOCUSING. EXPECT WIND GUSTS TO 40 TO 45 MPH THROUGH EARLY TO MID
AFTERNOON. WILL HOLD OFF ON ISSUING AN ADVISORY...AS EXPECTING
ONLY SPORADIC GUSTS TO 45 MPH.
RC
&&
.SHORT TERM...
313 AM CST
THROUGH TONIGHT...
COMPLEX STORM SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH
TONIGHT WITH A TRANSITION FROM MILD AND RAINY TOWARD COLD AND
POTENTIALLY SNOWY LIKELY TO TAKE PLACE LATER THIS MORNING.
DEEPENING SURFACE LOW FROM CENTRAL LAKE MICHIGAN EAST INTO LOWER
MICHIGAN WILL CONTINUE TO LIFT NORTHEAST TODAY AND DEEPEN FURTHER.
COLD FRONT TRAILING THIS BROAD LOW IS CROSSING THE MISSISSIPPI RIVER
NOW AND WILL STEADILY MARCH EAST ACROSS OUR CWA THIS MORNING
RESULTING IN STEADILY FALLING TEMPERATURES FROM THE POINT OF FROPA
THROUGH TONIGHT.
THE PRIMARY DEFORMATION ZONE WITH THIS SYSTEM IS MOVING OUT OF THE
AREA AT THIS TIME...HOWEVER THERE ARE A COUPLE ADDITIONAL VORTICITY
MAXIMA UPSTREAM. THE FIRST WELL DEFINED VORT IS NEAR STL WITH A SLUG
OF RAIN AND EVEN A COUPLE OF ISOLATED THUNDERSTORMS. THIS VORT IS
PROGGED TO SHEAR ENE CENTRAL ILLINOIS INTO NORTHERN OHIO TODAY. A
SECOND VORT MAX IS LOCATED UPSTREAM OVER KANSAS AND PIVOTING AROUND
THE BASE OF THE TROUGH AND EVENTUALLY PHASE WITH THE SHEARING OUT
VORT OVER INDIANA AND OHIO THIS AFTERNOON. AS THIS PROCESS TAKES
PLACE...THE RAIN ASSOCIATED WITH VORT ONE WILL SPREAD NORTHEAST
ACROSS OUR CWA THIS MORNING. AS THE SECOND VORT BEGINS TO PHASE WITH
THE FIRST A ZONE OF MID-LEVEL FRONTOGENESIS WILL DEVELOP ACROSS THE
LOWER LAKES THIS AFTERNOON AND ALLOW PRECIP WITH FIRST VORT TO
MAINTAIN ITSELF AND EVEN DEVELOP UPSTREAM (WESTWARD) INTO FAR
NORTHERN ILLINOIS AND ESPECIALLY INTO SOUTHERN WISCONSIN.
GUIDANCE HAS ALL SHIFTED NORTHWARD WITH THIS PROCESS COMPARED WITH
EARLIER RUNS AND ITS DIFFICULT TO FIND ANY MODEL THAT STILL SUPPORTS
THE 3-5" FORECAST TOTALS WE HAVE GOING IN THE ADVISORY AREA. AM VERY
LEARY ABOUT OVER CORRECTING THINGS SO DID A LOT OF FUZZY MATH AND
FUDGING OF GRIDS TO MAINTAIN AMOUNTS IN THE 2-5" RANGE IN THE
ADVISORY AREA...THOUGH SUSPECT MAJORITY OF THE ADVISORY AREA WILL
END UP WITH TOTALS ON THE BOTTOM END OF THE RANGE. SOUTH OF THE
ADVISORY AREA STILL THINK THERE COULD BE A CHANGEOVER TO SNOW BEFORE
THE DEFORMATION AXIS SHIFTS NORTHWARD AND PRECIP TAPER OFF THIS
AFTERNOON. IF CHANGE OVER ISNT FAST ENOUGH THEN COULD END UP WITH
JUST A TRACE OF SNOW...THOUGH FASTER CHANGE OVER AND BRIEF HEAVIER
INTENSITY COULD SUPPORT AMOUNTS AROUND AN INCH. BEFORE THE ENTIRE
CHANNELED VORT MAX TRANSLATES NORTHEAST OUT OF THE AREA COULD SEE
WESTERN EXTENT OF THE AXIS PIVOT BACK SOUTHWARD A BIT THIS AFTERNOON
INTO OUR NORTHWEST CWA...AND THIS WOULD BE NECESSARY TO GET FORECAST
AMOUNTS.
STRONG WESTERLY WINDS DEVELOP THIS MORNING BEHIND THE COLD FRONT AND
WILL CONTINUE INTO THIS EVENING. THE WINDS WILL WHIP AROUND ANY
FALLING SNOW LEADING TO GREATER REDUCTIONS IN VSBY. IN ADDITION...AS
TEMPS CONTINUE TO FALL FARTHER BELOW FREEZING LATER THIS AFTERNOON
SOME OF THE SNOW ON THE GROUND COULD GET BLOWN AROUND AS SNOW LIKELY
BECOMES MORE POWDERY IN NATURE.
IZZI
&&
.LONG TERM...
313 AM CST
TUESDAY ONWARD...
EXPANSIVE STRATUS DECK LIKELY TO BECOME ESTABLISHED OVER THE AREA
TUESDAY AND WHILE LOW LEVEL FLOW WILL BEGIN TO TRANSITION TO
ANTICYCLONIC TUESDAY AFTERNOON AHEAD OF THE NEXT CLIPPER...NOT SURE
HOW MUCH CLEARING THERE WILL BE AS DRY AIR ADVECTION WILL BE WEAK
WITH DIMINISHING FLOW. IN ADDITION...SUBSIDENCE WILL FURTHER SHARPEN
THE INVERSION CLOUDS ARE TRAPPED BENEATH SO HAVE INCREASED SKY COVER
TUESDAY AND NO LONGER SHOW ANY SUBSTANTIAL CLEARING BEFORE THE MID
WEEK CLIPPER COMES ZIPPING DOWN. GIVEN THE ANTICIPATED CLOUD COVER
HAVE GONE WITH SMALLER DIURNAL TEMP SWINGS WITH CLOUDS PROBABLY
KEEPING TEMPS UP A SMIDGE OVER GUIDANCE AT NIGHT AND A BIT LOWER
DURING THE DAY.
SPEAKING OF THE MID WEEK CLIPPER...GUIDANCE REMAINS INCONSISTENT RUN
TO RUN AND MODEL TO MODEL. THERE HAS BEEN A DISTINCT SOUTHWARD SHIFT
IN GUIDANCE WITH THIS SYSTEM WHICH IF IT WERE TO PAN OUT WOULD PLACE
THE ACCUMULATING SNOW OVER MAINLY OUR SOUTHERN CWA AND POTENTIALLY
BYPASS NORTHERN CWA. THIS CLIPPER IS ORIGINATING AS A PIECE OF
ENERGY BREAKING OFF AN UPPER LOW NEAR THE NORTHERN ALEUTIANS AND
SEEING AS IT HADNT EVEN BROKEN OFF THE LOW AND BEEN WELL SAMPLED YET
AM NOT READY TO THROW MY EGGS IN THE MORE SOUTHERLY TRACK BASKET
JUST YET. BY 12Z WEDNESDAY THE GFS ENSEMBLES HAVE SURFACE LOW
POSITIONS RANGING FROM WESTERN WISCONSIN TO NORTHWEST ARKANSAS...SO
NEEDLESS TO SAY FURTHER CHANGES ARE LIKELY THE NEXT SEVERAL GUIDANCE
CYCLES WITH THIS SYSTEM AND IT IS TOO SOON TO WRITE OFF THE THREAT
OF LIGHT ACCUMULATING SNOW ANYWHERE IN OUR CWA.
ANOTHER INTERESTING TWIST IN THE LATEST MEDIUM RANGE GUIDANCE IS
LESS OF A COLD INTRUSION IN THE WAKE OF THIS CLIPPER FOLLOWED BY A
RAPID TRANSITION TO ZONAL FLOW BY FRIDAY AND INTO THE WEEKEND.
GFS...GEM...AND ECMWF ALL TRACK A SFC LOW OF VARYING STRENGTHS
ACROSS THE UPPER GREAT LAKES SATURDAY PLACING OUR AREA IN WHAT WOULD
BE A VERY MILD SOUTHERLY FLOW. THE 00Z ECMWF THERMAL FIELDS WOULD
SUPPORT HIGHS WELL INTO THE 50S BY SATURDAY...BUT OBVIOUSLY DIDN`T
MAKE THAT DRASTIC OF A CHANGE TO THE GOING FORECAST BUT IF MODELS
REMAIN CONSISTENT WITH THIS LATEST TREND THEN A MILD WEEKEND COULD
BE ON TAP FOR THE REGION.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* WEST WINDS TO 10 KT WITH GUSTS TO 30 KT WITH A PERIOD OF 35 KT
GUSTS POSSIBLE MIDDAY/EARLY AFTERNOON.
* SOME LIGHT ACCUMULATION POSSIBLE...ESPECIALLY AROUND MIDDAY.
LIGHTER -SHSN CONTINUE INTO THE EVENING WITH SOME ADDITIONAL
LIGHT ACCUMULATIONS.
* PATCHY IFR TRENDING TO MVFR CIGS.
KMD/BEACHLER
//DISCUSSION...UPDATED 12Z...
THE NEXT BATCH OF PRECIPIATION IS FORECAST TO MOVE TSHORTLY WITH INITIAL
PRECIPITATION TYPE AS -RA. EXPECT CIGS TO REMAIN IFR BUT PROBABLY
LIFT SOME AS WEST WINDS BEGIN TO PICK UP WITH LOW PRESSURE MOVING
NORTHEASTWARD WITH -RASN MIX AROUND 15Z AT KRFD AND A FEW HOURS
LATER IN THE CHICAGO AREA...TURNING TO ALL -SN AROUND 18Z OR SO. THE
COLD AIR IS MAKING A GOOD RUN AT THE AREA SO SPED UP THE TIMING TO
TRANSITION TO -SN. MOISTURE WIL BE DECREASING FROM SOUTH TO NORTH
AS THE TRANSITION FROM -RA TO -SN OCCURS...SO SOME UNCERTAINTY AS
TO HOW LONG THE MODERATE SNOW WILL LAST THE HIGHEST LIKELIHOOD
FOR ACCUMS IS WEST AND NORTH OF THE MAIN CHICAGO TERMINALS TOWARD
ROCKFORD...BUT SOME ACCUMS ARE CERTAINLY STILL PLAUSIBLE
EVERYWHERE..ESPECIALLY IN THE 17Z-20Z TIME FRAME BEFORE THE MAIN
BATCH OF PRECIPITATION SHIFTS NORTHWARD. EXPECT IFR IN THE FIRST
SHOT OF SNOW THEN A TRANSITION TO MVFR WITH LIGHTER SNOW THROUGH
THE AFTERNOON. DURING THIS SAME TIME WINDS WILL BE RAMPING UP WITH
GUSTS TO 30 KT LIKELY...AND POSSIBLY GUSTS TO 35 KT FOR A TIME.
AFTERWARDS...WINDS SLOWLY SUBSIDE...AND THEN A FEW SNOW SHOWERS BUT
MOST LIKELY POSSIBLY JUST FLURRIES OVERNIGHT OR EVEN DRY CONDITIONS
WITH MVFR AND BREEZY WEST WINDS.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN WIND SPEED/DIR/GUSTS.
* HIGH CONFIDENCE IN PRECIP TYPE BEING ALL SNOW BY 18Z.
* HIGH CONFIDENCE ON CIG TRENDS.
KMD/BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...SCHC SNOW. OTHERWISE VFR. SOUTHEAST TO EAST WINDS.
THURSDAY...A FEW FLURRIES POSSIBLE...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST-SOUTHWEST WINDS.
SUNDAY...VFR. NORTH WINDS.
KMD
&&
.MARINE...
154 AM CST
DEEPENING LOW PRESSURE IS PASSING OVER THE LAKE EARLY THIS MORNING
BRINGING A LULL IN WINDS AND WAVES. THE LOW WILL CONTINUE NORTHEAST
INTO SOUTHWEST QUEBEC LATER THIS AFTERNOON THEN REMAIN STEADY AS IT
PUSHES OFFSHORE OVER NOVA SCOTIA. A STRONG SOUTHWEST TO NORTHEAST
ORIENTED PRESSURE GRADIENT WILL REACH THE SOUTH TIP OF THE LAKE BY
15Z...THEN SPREAD OVER THE REMAINDER OF THE LAKE IN THE AFTERNOON.
GALES LOOK SOLID FOR THE SOUTH HALF OF THE THE LAKE...BUT DUE TO A
WEAKENING PRESSURE GRADIENT WITH TIME TODAY AND A MODEST HIGH
BUILDING INTO THE CANADIAN PRARIES AND UPPER MIDWEST...FEEL THAT
WINDS WILL LIKELY PEAK JUST UNDER GALES FOR THE NORTH HALF. A FEW
GALE FORCE GUSTS ARE POSSIBLE...ESPECIALLY LATE AFTERNOON/EARLY
EVENING.
WEAK HIGH PRESSSURE EXTENDING FROM THE NORTH TIP OF LAKE SUPERIOR TO
THE OHIO VALLEY PASSES OVER THE LAKE TUESDAY AFTERNOON. ANOTHER
WEAKENING LOW EMERGING FROM THE CANADIAN ROCKIES WILL PASS JUST
SOUTH OF THE TIP OF LAKE MICHIGAN WITH THE REMNANT INVERTED TROUGH
CLEARING THE LAKE BY THURSDAY MORNING. THIS WILL BE FOLLOWED BY WEAK
HIGH PRESSSURE FOR A FEW DAYS.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012 UNTIL MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM TUESDAY.
&&
$$
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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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1046 AM CST Mon Nov 24 2014
.UPDATE...
ISSUED AT 1045 AM CST MON NOV 24 2014
Updated the forecast to adjust winds and precipitation chances
today. Kept the wind advisory going into the afternoon for eastern
IL but will likely be able to cancel early as very strong and
still deepening 977 mb low pressure over eastern Ontario pulls
ne away from the Great Lakes region. Still getting some sustained
winds 25 to 30 mph with gusts of 35 to 45 mph in our ne counties
late this morning. Light snow north of I-72 is starting to
diminish and expect this trend to continue into this afternoon as
light snow chances diminish to slight chance and flurries. Highs
have already been reached early this morning with current temps
ranging from 30F at Galesburg to 45F at Mount Carmel airport.
Temps to mostly be in the low to mid 30s today and settle into the
upper 30s to near 40F in southeast IL this afternoon.
&&
.SHORT TERM...(Today)
ISSUED AT 329 AM CST MON NOV 24 2014
Several short-term forecast challenges today, as a potent storm
system tracks through the area. Of particular concern are
strong/gusty winds behind a departing frontal boundary and the
potential for a light accumulation of snow across the W/NW KILX
CWA.
08z/2am surface analysis shows cold front extending from southern
Lake Michigan to the Ozarks. An area of low pressure along the
boundary over southeast Missouri is currently enhancing lift and
triggering a few thunderstorms along/south of the I-70 corridor.
This activity will push E/NE into Indiana by dawn. Further west, an
area of precipitation along/behind the front will continue to lift
northward, mainly impacting locations along/west of I-57. As colder
air streams into the region, the rain will gradually mix with and
change to snow by mid-morning. Based on upstream temp falls across
Iowa/Missouri, readings will drop into the middle 30s across the
Illinois River Valley by 12z/6am, then further east to the I-55
corridor by 15z/9am. At the same time, the precip will be pulling
northeastward out of the area, so there appears to be only a narrow
window of opportunity for snow across the W/NW. Will carry likely
to categorical PoPs across the western half of the CWA for rain
changing to snow this morning, with lower rain chances further east
and south across the remainder of the region. Main area of snow
will lift into northern Illinois by midday, with only a few
flurries/snow-showers persisting along/north of I-72 this
afternoon. Total snow accumulation will be limited due to light QPF
and marginally favorable temps. Around 1 inch is expected
along/north of a Canton to Bloomington-Normal line, with trace
amounts as far southeast as a Litchfield to Champaign-Urbana
line.
Other big story today will be the strong winds behind the cold
front. Upstream obs have already shown gusts as high as 30-40mph
and think these will translate eastward across central Illinois this
morning. Main question will be whether there may be a corridor of
enhanced winds approaching Wind Advisory criteria across the E/SE
CWA. Current MSAS analysis shows max 3-hour pressure rises of 6mb
over southern Missouri/northern Arkansas. Both the 00z and 06z runs
of the NAM have shown these rises tracking northeastward and
increasing to around 9mb over southeast Illinois later this
morning. HRRR 10m wind gust graphic also indicates increasing winds
ahead of the pressure change couplet as it moves across the
southeast CWA between 12z and 18z. Given this consistent signal,
think it is prudent to issue a Wind Advisory for locations
along/southeast of a Champaign to Taylorville line. While all of
central Illinois will experience wind gusts of 30 to 35 mph, this
particular area may see higher gusts exceeding 40 mph.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 329 AM CST MON NOV 24 2014
Low pressure will lift into the Great Lakes tonight, taking the bulk
of the precip with it. Wrap around moisture may brush across the
northern CWA, so have included scattered flurries in the forecast
this evening along/north of I-72. Forecast soundings indicate low
clouds will persist tonight and may even be slow to clear on
Tuesday, despite approaching surface ridge axis. Have therefore
slowed the clearing trend, with cloudy skies tonight followed by
decreasing clouds on Tuesday.
Fast-moving clipper system is still on target for mid-week, with
model consensus bringing the system across central Illinois on
Wednesday. This particular track is slightly further south than
previously advertised, so WAA ahead of the wave may not be quite as
pronounced as once thought. Even still, high temperatures will
climb well into the 30s and into the lower 40s across the southeast
CWA. End result will be light snow across the far north from the
Peoria area northward, a mix of light rain/snow across much of the
area, and mainly rain south of I-70. Due to the limited period of
light precip and warm temps, snow accumulations will be minimal.
Once this system passes to the east, another shot of cold air will
arrive for Thursday. After that, signs are still pointing to warmer
conditions by the end of the week, with temps climbing well into the
40s by Saturday. Both the GFS and ECMWF indicate a cold front will
drop through the region Saturday night, so temps will likely drop
back into the upper 30s/lower 40s by Sunday/Monday. Moisture will
be limited, so will maintain a dry FROPA at this time.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 534 AM CST MON NOV 24 2014
A strong cold front has surged across the central Illinois
terminals within the past few hours. Strong westerly winds, with
gusts approaching 35-40 kts at times, will linger through the day
before diminishing this evening. The lingering precipitation
wrapping in behind the front will quickly change over to snow this
morning before ending around midday. IFR or low end MVFR conditions
to start the period will climb into or further into the MVFR
category as the snow comes to an end. While it is possible cigs
may improve to VFR tonight, the better odds are that they will
remain in the MVFR category.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 6 PM CST this evening FOR ILZ044>046-052>057-
061>063-066>068-071>073.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Bak
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
315 PM EST MON NOV 24 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 340 AM EST MON NOV 24 2014
COLDER AIR WILL RETURN TO CENTRAL INDIANA LATER TODAY BEHIND THE
LOW PRESSURE SYSTEM AND COLD FRONT CURRENTLY IMPACTING THE AREA.
AS A RESULT...RAIN WILL TRANSITION TO SNOW LATE THIS
AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL. AFTER A
CHILLY BUT DRY DAY TOMORROW...ANOTHER SYSTEM WILL BRING LIGHT RAIN
AND SNOW ON WEDNESDAY. FURTHER OUT...THANKSGIVING DAY INTO THE
WEEKEND WILL BE COLD BUT DRY...AND PRECIPITATION WILL RETURN AGAIN
ON SUNDAY.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 1016 AM EST MON NOV 24 2014
FOR THE UPDATE...REMOVED THUNDER CHANCES WITH THE COLD FRONT
THROUGH THE AREA AND ALL THUNDER OFF TO THE EAST. DECREASED POPS
THIS AFTERNOON ACROSS THE NORTH BUT ADDED SOME LOW POPS TO THE
SOUTH BASED ON RECENT RUNS OF THE HRRR AND RAP AND WEAK WAVE
APPROACHING FROM THE SOUTHWEST. ALSO TRANSITIONED TO RAIN SNOW MIX A LITTLE
FASTER IN THE NORTHWEST BASED ON CURRENT OBS OF SNOW IN
ILLINOIS...BUT STILL THINK THE MAJORITY OF THAT WILL HEAD OFF TO
THE NORTHEAST AND MISS THE FORECAST AREA. STILL NOT EXPECTING MUCH
IF ANY ACCUMULATION. BUMPED HIGH END OF WIND GUSTS UP TO 50 MPH IN
THE NPW. TEMPERATURES WILL FALL FOR THE REMAINDER OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM PERIOD WILL BE THE STRONG
SOUTHWEST WINDS...AS WELL AS PRECIP CHANCES AND TYPES.
AN AREA OF LOW PRESSURE IS CURRENTLY POSITIONED OVER LOWER
MICHIGAN WITH A WARM FRONT STRETCHING ACROSS OHIO...AND A TRAILING
COLD FRONT TRACKING ACROSS ILLINOIS. CURRENT RADAR MOSAIC SHOWS
SCATTERED SHOWERS WITH A FEW ISOLATED THUNDERSTORMS OVER MUCH OF
ILLINOIS AND THE SOUTHERN HALF OF CENTRAL INDIANA. FORCING FROM
THE COLD FRONT WILL JUSTIFY LIKELY POPS THROUGH LATE MORNING.
HOWEVER...BEST FORCING WILL BECOME CONFINED TO THE NORTHERN
COUNTIES THIS AFTERNOON AS UPPER TROUGH MOVES THROUGH THE AREA. AS
A RESULT...WILL ONLY CARRY MENTION OF PRECIP OVER THE NORTHERN
HALF OF CENTRAL INDIANA INTO TONIGHT...AND WILL GO WITH A DRY
FORECAST ACROSS THE SOUTHERN HALF. RAIN WILL TRANSITION TO SNOW
LATE THIS AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL
SINCE MOST MOISTURE WILL BE OUT OF THE AREA.
TEMPS WILL START OUT IN THE 50S THIS MORNING...BUT QUICKLY FALL
INTO THE MID 30S THROUGH THE COURSE OF THE DAY AS COLDER AIR
ENTERS THE AREA. TONIGHT...OVERNIGHT LOWS WILL FALL INTO THE UPPER
20S...STUCK CLOSE TO GUIDANCE.
A WIND ADVISORY REMAINS IN EFFECT FOR ALL OF CENTRAL INDIANA TODAY
AS PRESSURE GRADIENT TIGHTENS. SUSTAINED SPEEDS OUT OF THE
SOUTHWEST ARE EXPECTED TO BE BETWEEN 20 TO 25 MPH WITH GUSTS UP TO
45 MPH AT TIMES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 340 AM EST MON NOV 24 2014
DRY AND COOLER WEATHER WILL PREVAIL ON TUESDAY. HOWEVER...THE
PATTERN WILL BECOME MORE ACTIVE AGAIN BY WEDNESDAY AS AN UPPER
TROUGH TRACKS ACROSS THE LOWER MIDWEST. PRECIP SHOULD BE IN THE
FORM OF RAIN ACROSS THE SOUTHERN HALF OF CENTRAL INDIANA ON
WEDNESDAY WITH A RAIN/SNOW MIX OVER THE NORTHERN HALF. AS TEMPS
FALL ON WEDNESDAY NIGHT THOUGH...PRECIP WILL TRANSITION TO SNOW.
MODELS HAVE THIS DISTURBANCE MOVING THROUGH QUICKLY THOUGH...SO
SNOW ACCUMULATIONS SHOULD BE RELATIVELY LOW...LESS THAN AN INCH.
HIGH TEMPS THROUGH THE SHORT TERM PERIOD WILL BE IN THE 30S WITH
LOWS IN THE 20S. THE MAV CONTINUES TO LOOK A TAD TOO WARM...SO
STUCK CLOSER TO A MODEL BLEND.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 232 PM EST MON NOV 24 2014
ZONAL FLOW WILL COMMENCE THROUGH THE FIRST HALF OF THE
WEEKEND...KEEPING CONDITIONS MAINLY DRY. THE NEXT SYSTEM IS DUE TO
IMPACT THE REGION SATURDAY NIGHT INTO SUNDAY NIGHT WITH CHANCES FOR
RAIN...AND EVEN A RAIN/SNOW MIX POSSIBLE OVER THE NORTHERN COUNTIES
SUNDAY NIGHT. PRECIP ACCUMULATIONS STILL LOOK VERY LIGHT AT THIS
TIME SO LEFT POPS AT SLIGHT TO LOW END CHANCES. SUPERBLEND GUIDANCE
INITIALIZED WELL. ONLY NEED TO MAKE A FEW MINOR TWEAKS.
&&
.AVIATION /DISCUSSION FOR 242100Z TAF UPDATE/...
ISSUED AT 315 PM EST MON NOV 24 2014
MVFR CEILINGS WILL PREVAIL THROUGH THE ENTIRE PERIOD. INDICATED
EITHER A PREVAILING -SHSN OR A TEMPO GROUP UNTIL EVENING TO
ACCOUNT FOR THE SCATTERED LIGHT SNOW SHOWERS WHICH ARE DEVELOPING
OVER CENTRAL INDIANA. PER RECENT OBS NOT EXPECTING ANY REDUCTIONS
IN VISIBILITY...HOWEVER IT/S POSSIBLE A FEW STRONGER SHSN MAY
BRIEFLY DROP CONDITIONS TO MVFR AT A FEW OF THE SITES.
GUSTY WINDS WILL CONTINUE UNTIL LATE TONIGHT. STRONG WEST TO
SOUTHWEST WINDS UP TO 25 KNOTS AND GUSTS 30 TO 40 KNOTS WILL
CONTINUE THROUGH THIS AFTERNOON. WINDS WILL DECREASE SOME THIS
EVENING AS THE PRESSURE GRADIENT RELAXES A LITTLE...THEN BECOME 10
KT OR LESS BY EARLY TUESDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR INZ021-028>030-
035>037-039-043>048-051>057-060>065-067>072.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ031-038-
040>042-049.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....SMF
AVIATION...SMF/JK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
233 PM EST MON NOV 24 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 340 AM EST MON NOV 24 2014
COLDER AIR WILL RETURN TO CENTRAL INDIANA LATER TODAY BEHIND THE
LOW PRESSURE SYSTEM AND COLD FRONT CURRENTLY IMPACTING THE AREA.
AS A RESULT...RAIN WILL TRANSITION TO SNOW LATE THIS
AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL. AFTER A
CHILLY BUT DRY DAY TOMORROW...ANOTHER SYSTEM WILL BRING LIGHT RAIN
AND SNOW ON WEDNESDAY. FURTHER OUT...THANKSGIVING DAY INTO THE
WEEKEND WILL BE COLD BUT DRY...AND PRECIPITATION WILL RETURN AGAIN
ON SUNDAY.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 1016 AM EST MON NOV 24 2014
FOR THE UPDATE...REMOVED THUNDER CHANCES WITH THE COLD FRONT
THROUGH THE AREA AND ALL THUNDER OFF TO THE EAST. DECREASED POPS
THIS AFTERNOON ACROSS THE NORTH BUT ADDED SOME LOW POPS TO THE
SOUTH BASED ON RECENT RUNS OF THE HRRR AND RAP AND WEAK WAVE
APPROACHING FROM THE SOUTHWEST. ALSO TRANSITIONED TO RAIN SNOW MIX A LITTLE
FASTER IN THE NORTHWEST BASED ON CURRENT OBS OF SNOW IN
ILLINOIS...BUT STILL THINK THE MAJORITY OF THAT WILL HEAD OFF TO
THE NORTHEAST AND MISS THE FORECAST AREA. STILL NOT EXPECTING MUCH
IF ANY ACCUMULATION. BUMPED HIGH END OF WIND GUSTS UP TO 50 MPH IN
THE NPW. TEMPERATURES WILL FALL FOR THE REMAINDER OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM PERIOD WILL BE THE STRONG
SOUTHWEST WINDS...AS WELL AS PRECIP CHANCES AND TYPES.
AN AREA OF LOW PRESSURE IS CURRENTLY POSITIONED OVER LOWER
MICHIGAN WITH A WARM FRONT STRETCHING ACROSS OHIO...AND A TRAILING
COLD FRONT TRACKING ACROSS ILLINOIS. CURRENT RADAR MOSAIC SHOWS
SCATTERED SHOWERS WITH A FEW ISOLATED THUNDERSTORMS OVER MUCH OF
ILLINOIS AND THE SOUTHERN HALF OF CENTRAL INDIANA. FORCING FROM
THE COLD FRONT WILL JUSTIFY LIKELY POPS THROUGH LATE MORNING.
HOWEVER...BEST FORCING WILL BECOME CONFINED TO THE NORTHERN
COUNTIES THIS AFTERNOON AS UPPER TROUGH MOVES THROUGH THE AREA. AS
A RESULT...WILL ONLY CARRY MENTION OF PRECIP OVER THE NORTHERN
HALF OF CENTRAL INDIANA INTO TONIGHT...AND WILL GO WITH A DRY
FORECAST ACROSS THE SOUTHERN HALF. RAIN WILL TRANSITION TO SNOW
LATE THIS AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL
SINCE MOST MOISTURE WILL BE OUT OF THE AREA.
TEMPS WILL START OUT IN THE 50S THIS MORNING...BUT QUICKLY FALL
INTO THE MID 30S THROUGH THE COURSE OF THE DAY AS COLDER AIR
ENTERS THE AREA. TONIGHT...OVERNIGHT LOWS WILL FALL INTO THE UPPER
20S...STUCK CLOSE TO GUIDANCE.
A WIND ADVISORY REMAINS IN EFFECT FOR ALL OF CENTRAL INDIANA TODAY
AS PRESSURE GRADIENT TIGHTENS. SUSTAINED SPEEDS OUT OF THE
SOUTHWEST ARE EXPECTED TO BE BETWEEN 20 TO 25 MPH WITH GUSTS UP TO
45 MPH AT TIMES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 340 AM EST MON NOV 24 2014
DRY AND COOLER WEATHER WILL PREVAIL ON TUESDAY. HOWEVER...THE
PATTERN WILL BECOME MORE ACTIVE AGAIN BY WEDNESDAY AS AN UPPER
TROUGH TRACKS ACROSS THE LOWER MIDWEST. PRECIP SHOULD BE IN THE
FORM OF RAIN ACROSS THE SOUTHERN HALF OF CENTRAL INDIANA ON
WEDNESDAY WITH A RAIN/SNOW MIX OVER THE NORTHERN HALF. AS TEMPS
FALL ON WEDNESDAY NIGHT THOUGH...PRECIP WILL TRANSITION TO SNOW.
MODELS HAVE THIS DISTURBANCE MOVING THROUGH QUICKLY THOUGH...SO
SNOW ACCUMULATIONS SHOULD BE RELATIVELY LOW...LESS THAN AN INCH.
HIGH TEMPS THROUGH THE SHORT TERM PERIOD WILL BE IN THE 30S WITH
LOWS IN THE 20S. THE MAV CONTINUES TO LOOK A TAD TOO WARM...SO
STUCK CLOSER TO A MODEL BLEND.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 232 PM EST MON NOV 24 2014
ZONAL FLOW WILL COMMENCE THROUGH THE FIRST HALF OF THE
WEEKEND...KEEPING CONDITIONS MAINLY DRY. THE NEXT SYSTEM IS DUE TO
IMPACT THE REGION SATURDAY NIGHT INTO SUNDAY NIGHT WITH CHANCES FOR
RAIN...AND EVEN A RAIN/SNOW MIX POSSIBLE OVER THE NORTHERN COUNTIES
SUNDAY NIGHT. PRECIP ACCUMULATIONS STILL LOOK VERY LIGHT AT THIS
TIME SO LEFT POPS AT SLIGHT TO LOW END CHANCES. SUPERBLEND GUIDANCE
INITIALIZED WELL. ONLY NEED TO MAKE A FEW MINOR TWEAKS.
&&
.AVIATION /DISCUSSION FOR THE 241800Z TAF ISSUANCE...
ISSUED AT 1152 AM EST MON NOV 24 2014
MVFR CEILINGS WILL PREVAIL THROUGH THE ENTIRE PERIOD WITH IFR
CONDITIONS POSSIBLE IN ANY MODERATE SNOW SHOWERS THROUGH THIS
AFTERNOON. INDICATED EITHER A PREVAILING -SHSN OR A TEMPO GROUP
FOR THE FIRST 3-4 HOURS OF THE TAF PERIOD TO ACCOUNT FOR THE
SCATTERED LIGHT SNOW SHOWERS AND/OR FLURRIES WHICH ARE DEVELOPING
OVER CENTRAL INDIANA. PER RECENT OBS NOT EXPECTING ANY REDUCTIONS
IN VIS...HOWEVER IT/S POSSIBLE A FEW STRONGER SHSN MAY POP UP AND
BRIEFLY DROP CONDITIONS TO IFR AT A FEW OF THE SITES. CHANCES NOT
HIGH/CONFIDENT ENOUGH TO INCLUDE THIS AT THIS TIME...BUT IT/S A
POSSIBILITY.
GUSTY WINDS WILL CONTINUE UNTIL LATE TONIGHT. STRONG WEST TO
SOUTHWEST WINDS UP TO 25 KNOTS AND GUSTS 30 TO 40 KNOTS WILL
CONTINUE THROUGH THIS AFTERNOON. WINDS WILL DECREASE SOME THIS
EVENING AS THE PRESSURE GRADIENT RELAXES A LITTLE...THEN BECOME 10
KT OR LESS BY EARLY TUESDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR INZ021-028>030-
035>037-039-043>048-051>057-060>065-067>072.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ031-038-
040>042-049.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....SMF
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1200 PM EST MON NOV 24 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 340 AM EST MON NOV 24 2014
COLDER AIR WILL RETURN TO CENTRAL INDIANA LATER TODAY BEHIND THE
LOW PRESSURE SYSTEM AND COLD FRONT CURRENTLY IMPACTING THE AREA.
AS A RESULT...RAIN WILL TRANSITION TO SNOW LATE THIS
AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL. AFTER A
CHILLY BUT DRY DAY TOMORROW...ANOTHER SYSTEM WILL BRING LIGHT RAIN
AND SNOW ON WEDNESDAY. FURTHER OUT...THANKSGIVING DAY INTO THE
WEEKEND WILL BE COLD BUT DRY...AND PRECIPITATION WILL RETURN AGAIN
ON SUNDAY.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 1016 AM EST MON NOV 24 2014
FOR THE UPDATE...REMOVED THUNDER CHANCES WITH THE COLD FRONT
THROUGH THE AREA AND ALL THUNDER OFF TO THE EAST. DECREASED POPS
THIS AFTERNOON ACROSS THE NORTH BUT ADDED SOME LOW POPS TO THE
SOUTH BASED ON RECENT RUNS OF THE HRRR AND RAP AND WEAK WAVE
APPROACHING FROM THE SOUTHWEST. ALSO TRANSITIONED TO RAIN SNOW MIX A LITTLE
FASTER IN THE NORTHWEST BASED ON CURRENT OBS OF SNOW IN
ILLINOIS...BUT STILL THINK THE MAJORITY OF THAT WILL HEAD OFF TO
THE NORTHEAST AND MISS THE FORECAST AREA. STILL NOT EXPECTING MUCH
IF ANY ACCUMULATION. BUMPED HIGH END OF WIND GUSTS UP TO 50 MPH IN
THE NPW. TEMPERATURES WILL FALL FOR THE REMAINDER OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM PERIOD WILL BE THE STRONG
SOUTHWEST WINDS...AS WELL AS PRECIP CHANCES AND TYPES.
AN AREA OF LOW PRESSURE IS CURRENTLY POSITIONED OVER LOWER
MICHIGAN WITH A WARM FRONT STRETCHING ACROSS OHIO...AND A TRAILING
COLD FRONT TRACKING ACROSS ILLINOIS. CURRENT RADAR MOSAIC SHOWS
SCATTERED SHOWERS WITH A FEW ISOLATED THUNDERSTORMS OVER MUCH OF
ILLINOIS AND THE SOUTHERN HALF OF CENTRAL INDIANA. FORCING FROM
THE COLD FRONT WILL JUSTIFY LIKELY POPS THROUGH LATE MORNING.
HOWEVER...BEST FORCING WILL BECOME CONFINED TO THE NORTHERN
COUNTIES THIS AFTERNOON AS UPPER TROUGH MOVES THROUGH THE AREA. AS
A RESULT...WILL ONLY CARRY MENTION OF PRECIP OVER THE NORTHERN
HALF OF CENTRAL INDIANA INTO TONIGHT...AND WILL GO WITH A DRY
FORECAST ACROSS THE SOUTHERN HALF. RAIN WILL TRANSITION TO SNOW
LATE THIS AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL
SINCE MOST MOISTURE WILL BE OUT OF THE AREA.
TEMPS WILL START OUT IN THE 50S THIS MORNING...BUT QUICKLY FALL
INTO THE MID 30S THROUGH THE COURSE OF THE DAY AS COLDER AIR
ENTERS THE AREA. TONIGHT...OVERNIGHT LOWS WILL FALL INTO THE UPPER
20S...STUCK CLOSE TO GUIDANCE.
A WIND ADVISORY REMAINS IN EFFECT FOR ALL OF CENTRAL INDIANA TODAY
AS PRESSURE GRADIENT TIGHTENS. SUSTAINED SPEEDS OUT OF THE
SOUTHWEST ARE EXPECTED TO BE BETWEEN 20 TO 25 MPH WITH GUSTS UP TO
45 MPH AT TIMES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 340 AM EST MON NOV 24 2014
DRY AND COOLER WEATHER WILL PREVAIL ON TUESDAY. HOWEVER...THE
PATTERN WILL BECOME MORE ACTIVE AGAIN BY WEDNESDAY AS AN UPPER
TROUGH TRACKS ACROSS THE LOWER MIDWEST. PRECIP SHOULD BE IN THE
FORM OF RAIN ACROSS THE SOUTHERN HALF OF CENTRAL INDIANA ON
WEDNESDAY WITH A RAIN/SNOW MIX OVER THE NORTHERN HALF. AS TEMPS
FALL ON WEDNESDAY NIGHT THOUGH...PRECIP WILL TRANSITION TO SNOW.
MODELS HAVE THIS DISTURBANCE MOVING THROUGH QUICKLY THOUGH...SO
SNOW ACCUMULATIONS SHOULD BE RELATIVELY LOW...LESS THAN AN INCH.
HIGH TEMPS THROUGH THE SHORT TERM PERIOD WILL BE IN THE 30S WITH
LOWS IN THE 20S. THE MAV CONTINUES TO LOOK A TAD TOO WARM...SO
STUCK CLOSER TO A MODEL BLEND.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 340 AM EST MON NOV 24 2014
IN THE LONG TERM MODELS INDICATE A PROGRESSIVE SOMEWHAT ZONAL UPPER
FLOW. A BROAD UPPER TROUGH ACROSS EASTERN CANADA AND THE GREAT LAKES
THURSDAY WILL MOVE ON TO THE EAST TO BE REPLACED BY A WEAKER UPPER
TROUGH BY THE END OF DAY 7.
FOR THANKSGIVING DAY ADDED A CHANCE OF FLURRIES OVER THE EASTERN
HALF OF OUR REGION AS AN UPPER DISTURBANCE MOVES FROM THE UPPER OHIO
VALLEY TO THE EAST COAST. OTHERWISE...DRY WEATHER WILL BE THE RULE
THROUGH FRIDAY NIGHT AS HIGH PRESSURE MOVES OVER THE UPPER MI9WEST
MOVES ACROSS OUR REGION LATE THURSDAY NIGHT AND FRIDAY AND ON TO THE
EAST COAST. SOME MODELS INDICATE LOW CHANCE POPS ACROSS OUR FAR
NORTH FRIDAY...BUT HAVE DECIDED TO KEEP IT DRY FOR NOW.
OVER THE WEEKEND MODELS INDICATE INCREASING WARM ADVECTION AS LOW
PRESSURE MOVES INTO THE PLAINS. THEY ALL GENERATE SOME PRECIP
BEGINNING SATURDAY AND CONTINUING IT THROUGH SUNDAY AS A WARM FRONT
MOVES INTO THE MID MISSISSIPPI VALLEY AND A COLD FRONT APPROACHES
FROM THE UPPER MIDWEST BY SUNDAY.
MODELS HAVE TERNED A LITTLE WARMER OVER THE WEEKEND AND ANY
PRECIPITATION SHOULD BE MOSTLY LIQUID. CONCERNING TEMPERATURES WENT
WITH A MOS BLEND EARLY ON AND SLIGHTLY ABOVE OVER THE WEEKEND AS
WARM ADVECTION INCREASES.
&&
.AVIATION /DISCUSSION FOR THE 241800Z TAF ISSUANCE...
ISSUED AT 1152 AM EST MON NOV 24 2014
MVFR CEILINGS WILL PREVAIL THROUGH THE ENTIRE PERIOD WITH IFR
CONDITIONS POSSIBLE IN ANY MODERATE SNOW SHOWERS THROUGH THIS
AFTERNOON. INDICATED EITHER A PREVAILING -SHSN OR A TEMPO GROUP
FOR THE FIRST 3-4 HOURS OF THE TAF PERIOD TO ACCOUNT FOR THE
SCATTERED LIGHT SNOW SHOWERS AND/OR FLURRIES WHICH ARE DEVELOPING
OVER CENTRAL INDIANA. PER RECENT OBS NOT EXPECTING ANY REDUCTIONS
IN VIS...HOWEVER IT/S POSSIBLE A FEW STRONGER SHSN MAY POP UP AND
BRIEFLY DROP CONDITIONS TO IFR AT A FEW OF THE SITES. CHANCES NOT
HIGH/CONFIDENT ENOUGH TO INCLUDE THIS AT THIS TIME...BUT IT/S A
POSSIBILITY.
GUSTY WINDS WILL CONTINUE UNTIL LATE TONIGHT. STRONG WEST TO
SOUTHWEST WINDS UP TO 25 KNOTS AND GUSTS 30 TO 40 KNOTS WILL
CONTINUE THROUGH THIS AFTERNOON. WINDS WILL DECREASE SOME THIS
EVENING AS THE PRESSURE GRADIENT RELAXES A LITTLE...THEN BECOME 10
KT OR LESS BY EARLY TUESDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR INZ021-028>030-
035>037-039-043>048-051>057-060>065-067>072.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ031-038-
040>042-049.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....JH
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
334 PM EST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 325 PM EST MON NOV 24 2014
19Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING NORTHEAST
AWAY FROM THE GREAT LAKES. FROM THIS...A STRONG...BUT NOW DRY...COLD
FRONT IS PRESSING THROUGH EAST KENTUCKY. AHEAD OF THIS BOUNDARY...
STRONG SOUTHWEST WINDS ARE GUSTING ROUTINELY INTO THE 35 TO 45 MPH
RANGE WITH A FEW GUSTS EXCEEDING 50 MPH. THE OFFICE HAS RECEIVED
NUMEROUS REPORTS OF TREE DAMAGE AND POWER OUTAGES DUE TO THE WINDS.
THESE WINDS HAVE ALSO SUPPORTED TEMPERATURES IN THE UPPER 60S AND
LOWER 70S WITH DEWPOINTS IN THE MID 40S FOR MUCH OF THE AFTERNOON AND
THEY REMAIN THERE IN FAR EASTERN KENTUCKY. HOWEVER...ON THE OTHER
SIDE OF THE BOUNDARY THE WINDS REMAIN SOUTHWEST BUT ARE NOT QUITE AS
STRONG AND ARE BRINGING IN A DIFFERENT AIR MASS. AS SUCH...
TEMPERATURES DROPPING THROUGH THE 50S ARE NOW REACHING THE WESTERN
EXTENT OF THE CWA ALONG WITH DEWPOINTS HEADED FOR THE 30S. THE WINDS
REMAIN AT ADVISORY LEVEL IN THE EAST BUT ARE NOT QUITE THERE IN THE
WEST. AS THEY FURTHER SETTLE WE WILL LIKELY BE ABLE TO DROP THE
ADVISORY EARLY. FOR NOW...THOUGH...WILL CONTINUE TO LET IT RIDE FOR
THE ENTIRE CWA THROUGH 00Z.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE DEEP...AND FULL-
LATITUDE...TROUGH CROSSING THE OHIO VALLEY AND GREAT LAKES TODAY INTO
TUESDAY. HOWEVER...A SOUTHWESTERN EXTENT OF THE LARGER TROUGH WILL
REMAIN STRETCHED INTO SOUTHWESTERN TEXAS AND IT IS THIS SECTION
THAT TIGHTENS UP AND MOVES EAST LATER TUESDAY. THE SOUTHERN
ENERGY...IN CONJUNCTION WITH SOME MOVING THROUGH THE MID MISSISSIPPI
VALLEY WILL SWEEP THROUGH THE DEEP SOUTH AND ACROSS THE TENNESSEE
VALLEY ON TUESDAY NIGHT. OF NOTE ALSO...A CLUSTER OF ENERGY WILL BE
RIDING SOUTHEAST THROUGH THE CENTRAL PLAINS AT DAWN WEDNESDAY. WITH
THE MODEL AGREEMENT HAVE FAVORED THE NAM12 AND HRRR INITIALLY AND
THEN A BLEND OF THE ECMWF AND NAM12 FOR WX DETAILS INTO WEDNESDAY
MORNING.
SENSIBLE WEATHER WILL FEATURE WINDS SETTLING DOWN THIS EVENING FROM
WEST TO EAST AS THE GRADIENT RELAXES. IT WILL ALSO MEAN A COOLER
EVENING...BUT NOWHERE NEAR AS COLD AS IT HAS BEEN OF LATE. TUESDAY
WILL CERTAINLY BE A COOLER DAY BUT A QUIETER ONE AS WE WILL BE
BETWEEN SYSTEMS. A DEVELOPING SFC LOW ALONG THE SOUTHEAST COAST WILL
START TO SPREAD HIGH CLOUDS INTO THE AREA FROM THE SOUTHEAST BY
EVENING. LOOK FOR THESE TO THICKEN AND LOWER WITH TIME THAT NIGHT AS
THE SOUTHEAST PORTION OF THE CWA IS BRUSHED BY THE PCPN SHIELD FROM
THIS NASCENT COASTAL SYSTEM. HAVE CONTINUED THE THREAT OF RAIN OR
SNOW PRIMARILY IN THE COUNTIES BORDERING VIRGINIA...BUT NOT
ANTICIPATING MUCH IN THE WAY OF ACCUMULATIONS EXCEPT PERHAPS A TOUCH
OF IT JUST ON THE PEAK OF BLACK MOUNTAIN.
USED THE BCCONSSHORT AS A STARTING POINT FOR T/TD/WINDS THROUGH THE
NEXT 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR
TERRAIN BASED ADJUSTMENTS TONIGHT AND TUESDAY NIGHT TO THE LOWS. AS
FOR POPS...ENDED UP CLOSE TO A BLEND OF THE MAV AND MET NUMBERS FOR
TUESDAY NIGHT AND DRY OTHERWISE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 PM EST MON NOV 24 2014
THERE WILL BE A DEVELOPING SURFACE LOW OFF THE CAROLINA COAST BEGINNING
THE PERIOD AND THE FRONTOGENESIS IS AIDED BY A BROAD TROUGH/EMBEDDED
SHORTWAVE ENERGY SWING THROUGH THE EASTERN U.S. THOROUGH THE PERIOD.
THIS COASTAL LOW IS EXPECTED TO MOVE NE ALONG THE ATLANTIC SEABOARD
WEDNESDAY INTO THURSDAY. ANOTHER EMBEDDED SHORTWAVE WILL EXIT THE
UPPER PLAINS AND DROP SE INTO THE OHIO AND TENNESSEE VALLEYS
WEDNESDAY NIGHT INTO THURSDAY. SURFACE HIGH WILL BUILD EAST LATER
THURSDAY INTO FRIDAY. UPPER LEVELS WILL BEGIN TO BECOME MORE ZONAL
WITH SURFACE FRONT DEVELOPING ACROSS PORTIONS OF THE OHIO VALLEY
GOING INTO SUNDAY INTO MONDAY.
SENSIBLE WEATHER... GIVEN SYNOPTIC SETUP LOW PRESSURE MOVING ALONG
THE ATLANTIC COAST COULD BRING SLIGHT TO CHANCES MAINLY RAIN/SNOW
SHOWERS ACROSS THE EASTERN AND SOUTHEASTERN PORTIONS OF THE REGION
EARLY WEDNESDAY...BEFORE TRANSITIONING TO RAIN SHOWERS THROUGH THE
DAY WEDNESDAY. THIS LOW WILL TRACK NORTH AND EAST WHILE AFOREMENTIONED
DISTURBANCE DROPS SE ACROSS THE REGION WEDNESDAY NIGHT. THERE IS
BETTER AGREEMENT WITH MODELS SO DID OPT TO BRING POPS UP A BIT FOR
THIS SYSTEM. THIS SYSTEM IS EXPECTED TO BRING SLIGHT TO CHANCE
RAIN/SNOW SHOWERS ACROSS EASTERN KY WEDNESDAY NIGHT. THURSDAY MUCH OF
THE REGION WILL WARM UP SO EXPECT MOST OF THE ACTIVITY WILL
TRANSITION TO RAIN SHOWERS BEFORE EXITING THE REGION LATE IN THE DAY
ON THURSDAY. AFTER THIS IT IS EXPECTED TO BE QUIET AND MOSTLY CLEAR
CONDITIONS TIL WE GET TO THE SATURDAY TIME FRAME. DURING THIS TIME
MODELS ARE NOT IN GOOD AGREEMENT ON TIMING/DEVELOPMENT OF NEXT
SYSTEM. RIGHT NOW THINKING WILL ONLY GO WITH SLIGHT CHANCES OF RAIN
SHOWERS SATURDAY...THEN TRANSITION TO SLIGHT/CHANCE RAINS SHOWERS AS
FRONT SLOW PROGRESSES SOUTH ACROSS THE REGION GOING INTO SUNDAY AND
MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 105 PM EST MON NOV 24 2014
A STRONG...BUT MOSTLY DRY...COLD FRONT IS CROSSING THROUGH EASTERN
KENTUCKY. FROM THIS...LITTLE MORE THAN A SPRINKLE WILL BE POSSIBLE AT
THE TAF SITES THROUGH THE REST OF THE DAY. MID LEVEL CIGS WILL
EVENTUALLY BREAK UP BY LATE IN THE DAY...BUT NOT BEFORE A FEW MVFR
CIGS DRIFT THROUGH THE NORTHERN SITES...POST FRONTAL. LATE TONIGHT
AND THROUGH THE DAY TUESDAY THE SKIES WILL BE VFR. THE MAIN AVIATION
IMPACT WILL BE STRONG AND GUSTY SOUTHWEST WINDS THROUGH EARLY
EVENING. SOUTHWEST WIND GUSTS ARE OCCASIONALLY REACHING 40 KNOTS IN
PLACES THIS AFTERNOON WITH THIS EXPECTED TO CONTINUE FOR AT LEAST
SEVERAL MORE HOURS. WHILE WINDS SHOULD DIMINISH INTO THE
EVENING...FOLLOWING FROPA...THEY COULD REMAIN GUSTY IN SOME PLACES
THROUGH MIDNIGHT BEFORE BECOMING LIGHT AND VARIABLE INTO THE DAY
TUESDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 PM EST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 358 PM EST MON NOV 24 2014
COLD AIR IS RAPIDLY MOVING ACROSS UPPER MICHIGAN. MOST PLACES EXCEPT
THE FAR SOUTH AND EAST HAVE TURNED OVER TO SNOW AS 850MB TEMPS
RAPIDLY DROP TO -12C OR LOWER BEHIND THE SFC LOW. OTHER THAN NEAR
LAKE SUPERIOR...THE REST OF THE AREA IS UNDER A LULL OF
PRECIPITATION BEHIND THE FIRST UPPER DISTURBANCE RAPIDLY MOVING NE
INTO CANADA. HOWEVER...THE SECOND WAVE OF ENERGY CURRENTLY STILL
OVER THE IOWA AND SRN WI WILL MOVE TOWARD THE AREA THIS EVENING.
MODERATE MID LEVEL Q-VECTOR CONVERGENCE ALONG WITH MODERATE
850-700MB FRONTOGENETIC FORCING OWED TO THE MID LEVEL DEFORMATION
AXIS WILL MOVE ACROSS WI AND ACROSS THE FAR SOUTHERN PART OF THE
FORECAST AREA TONIGHT. THIS WILL ALLOW FOR A PERIOD OF SYSTEM SNOW
TO SPREAD ACROSS AREAS GENERALLY ALONG AND SOUTH OF U.S. 2 IN
MENOMINEE AND DELTA COUNTIES TONIGHT. RAPID UPDATE NWP SUGGEST UP TO
0.50 INCH OF LIQUID TONIGHT /WITH THE LATEST HRRR SUGGESTING UP TO
0.75 INCH/. BUT GIVEN THAT THE SYSTEM WILL BE MOVING FAIRLY FAST TO
THE NE AND 700MB SPECIFIC HUMIDITY VALUES ARE AT MOST 3 G/KM THIS
EVENING...AM EXPECTING QPF OF SLIGHTLY LESS THAN 0.50 INCH. WITH
SNOW RATIOS RISING TO 10-15:1 THIS EVENING...THIS WOULD SUGGEST THAT
FAR SOUTHERN MENOMINEE COUNTY COULD SEE 4-6 INCHES OF SNOW STARTING
LATE THIS AFTERNOON AND CONTINUING INTO OVERNIGHT. AS SUCH...HAVE
OPTED TO ISSUE A WINTER WEATHER ADVY FOR MENOMINEE COUNTY...FOCUSING
ON AREAS MAINLY SOUTH OF US 2. AM CURRENTLY THINKING THAT SYSTEM
PCPN WILL DIMINISH OVER A RELATIVELY SHORT DISTANCE TO THE
NORTH...SO AS OF NOW WILL LEAVE DICKINSON AND DELTA COUNTIES OUT OF
THE WINTER WEATHER ADVY.
AS FOR THE REMAINDER OF THE AREA...NO MAJOR CHANGES TO THE FORECAST
PLANNED. AS THE COLDER AIR MOVES ACROSS THE AREA THIS
EVENING...EXPECT BETTER LES BANDS TO DEVELOP IN THE N-NW
FLOW...SIMILAR TO WHAT IS OCCURRING AT IWD RIGHT NOW. CURRENT SNOW
RATIOS ARE FAIRLY LOW...GENERALLY 10-15:1 DUE TO THE SNOW GROWTH
REGION STILL FAIRLY HIGH. AS THE COLDER AIR MOVES IN...THE
EXPECTATION IS THAT THE SNOW RATIOS WILL BECOME HIGHER...CLOSER TO
20:1. AS SUCH...WILL MAINTAIN ALL LAKE EFFECT SNOW ADVISORIES AS
IS...WITH SIMILAR FORECAST AMOUNTS EXPECTED. STILL EXPECTING STORM
TOTAL OF 5-8 INCHES ACROSS THE GOGEBIC RANGE...4-7 INCHES
KEWEENAW...4-9 INCHES N-CENTRAL UPPER MI...AND 4-7 INCHES EAST OF
MARQUETTE. BLOWING SNOW NEAR LAKE SUPERIOR WILL STILL BE A PROBLEM
WITH SOME GUSTS IN EXCESS OF 30 MPH.
THE LES SHOULD GRADUALLY DIMINISH FROM WEST TO EAST LATE TONIGHT
INTO TUESDAY BEHIND THE UPPER TROUGH WHICH MOVES THROUGH LATE
TONIGHT. BEHIND THIS TROUGH...WEAK SFC RIDGING BUILDS IN ALONG WITH
BACKING PBL WINDS AND A DRIER AIRMASS ALLOWING FOR ANY REMAINING LES
TO SHIFT TO THE KEWEENAW AND ACROSS THE OPEN LAKE TUE AFTN. AS
SUCH...WILL MAINTAIN CHANCE POPS FOR THE ENTIRE DAY ACROSS THE
KEWEENAW BUT END THE POPS ACROSS THE FAR WEST. WILL MAINTAIN HIGHER
POPS EAST DUE TO W-NW FLOW HANGING ON FOR MUCH OF THE DAY THERE
ALONG WITH DEEPER MOISTURE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 408 PM EST MON NOV 24 2014
MAIN FCST CONCERNS IN THE LONGER TERM WL BE FOCUSED ON THE POTENTIAL
FOR AT LEAST SOME MARGINAL ADVY LES TOTALS ON WED INTO EARLY
THANKSGIVING ASSOCIATED WITH A SHRTWV DIGGING SEWD THRU THE UPR LKS.
FORTUNATELY FOR THOSE INTERESTED IN TRAVEL ON THANKSGIVING...MODELS
HAVE CONTINUED TREND TOWARD LESS PHASING BTWN A PAIR OF SHRTWVS THAT
WL LIMIT THE POTENTIAL FOR HEAVIER SN AWAY FM LK SUP. TEMPS WL RUN
BLO TO WELL BLO NORMAL ON TUE NGT INTO FRI WITH AN UPR TROF
DEEPENING OVER ERN NAMERICA. AS THIS TROF GIVES WAY TO A MORE ZONAL
FLOW THIS WEEKEND...A MORE CHANGEABLE PATTERN WL DOMINATE WITH
WARMER AIR IN STORE FOR SAT.
TUE NGT...A WEAK SFC HI PRES UNDER SUBTLE SHRTWV RDGING/AREA OF DEEP
LYR QVECTOR DVGC WL DOMINATE MOST OF THE NGT AND BRING DRY WX TO
MOST OF THE CWA. THE BEST CHC FOR SOME PCPN WL BE OVER THE NW CWA
NEAR A STATIONARY FNT ORIENTED W-E OVER LK SUP. H85 TEMPS ANRD -13C
MAY SUPPORT A LK EFFECT COMPONENT...ESPECIALLY LATE WHEN SOME DPVA/
DEEP LYR QVECTOR CNVGC IN ADVANCE OF A SHRTWV DIGGING SEWD TOWARD
THE CNDN/MN BORDER IS FCST TO ARRIVE. EXPECT THE LOWEST MIN TEMPS
OVER THE INTERIOR SCENTRAL AND E WHERE THE NEGATIVE DYNAMICS SHOULD
LINGER THRU THE NGT IN THE PRESENCE OF PWAT UNDER 0.25 INCH AND
MINIMIZE CLD COVER EXCEPT FOR SOME HIER CLDS SPILLING INTO UPR MI
AHEAD OF THE INCOMING SHRWTV.
WED...SHRTWV APRCHG FM THE NW IS FCST TO MOVE INTO WRN LK SUP BY 00Z
THU...WITH DPVA/DEEP LYR QVECTOR CNVGC INVADING UPR MI. BUT SINCE
THE MODELS HAVE TRENDED TOWARD LESS PHASING BTWN THIS SHRTWV AND
ANOTHER STRONGER DISTURBANCE DIGGING SEWD IN THE MID MS RIVER VALLEY
THAT WL ROB THE AREA OF DEEPER MSTR AND LEAVE PWAT NO HIER THAN
ABOUT 0.25-0.30 INCH...ACCOMPANYING SN OVER THE CWA SHOULD BE
RELATIVELY LGT. THE BEST CHC FOR MORE SN WL BE IN THE N WIND SN
BELTS NEAR LK SUP AS THE H925 FLOW SHIFTS TO THE N COINCIDENT WITH
PASSING NRN SHRTWV AND ALLOWS FOR SOME LES AS H85 TEMPS FALL TO ARND
-15C OVER THE NW BY 00Z WED. SN TOTALS IN THAT AREA MAY ALSO BE
BOOSTED A BIT BY RATHER DEEP DGZ BTWN ABOUT 4-9K FT MSL EVEN THOUGH
MORE SHARPER UVV IS NOT FCST WITHIN THAT LYR. NOT OUT OF THE
QUESTION THE FLOW MAY BACK SUFFICIENTLY TO THE SW IN ADVANCE OF THE
SHRTWV TO ALLOW FOR A PERIOD OF SOME LK EFFECT SN OFF LK MI INTO THE
SE CWA IN THE PRESENCE OF H85 TEMPS NEAR -10C.
WED NGT...STEADY NNW WIND IN THE WAKE OF PASSING SHRTWV IS FCST TO
ADVECT H85 TEMPS AS LO AS -20C OVER THE KEWEENAW BY 12Z THU. THERE
MAY BE SOME ADVY LVL LES IN THE FAVORED SN BELTS AS THERE WL BE A
PERIOD WHERE THE FAVORABLE CAA/CYC NNW FLOW IS COINCIDENT WITH
DEEPER MSTR/SOME DEEP LYR QVECTOR CNVGC THAT WL LIKELY BRING SOME
LIGHTER SN EVEN TO THE SCENTRAL. THE ARRIVAL OF SOME DNVA/DEEP LYR
QVECTOR DVGC LATER AT NGT IS PROGGED TO SHARPLY LOWER INVRN BASE
TOWARD H85...WHICH SHOULD BRING ABOUT A DIMINISHING TREND IN THE LES
OVER AT LEAST THE W HALF. THE 12Z GFS IS FASTEST WITH THIS
DIMINISHING TREND.
THANKSGIVING/THU NGT...THE LLVL FLOW IS PROGGED TO BACK STEADILY AND
TURN MORE ACYC ON THANKSGIVING WITH SFC HI PRES MOVING TOWARD WI
LATE IN THE DAY UNDER HGT RISES/DNVA IN ADVANCE OF APRCHG SHRTWV
RDG. THE RESULT WL BE SHIFTING/DIMINISHING LES BANDS...ESPECIALLY
OVER THE W HALF. THE LES WL BE MORE PERSISTENT IN THE FAVORED SN
BELTS E OF MARQUETTE...BUT LO INVRN BASE BLO H85 SHOWN ON THE FCST
SDNGS UNDER THE NEGATIVE DYNAMICS WL LIMIT SN TOTALS. AS THE SFC
RDG AXIS SHIFTS TO THE E AND THE FLOW BACKS TO THE W-SW...LINGERING
LES WL SHIFT OUT INTO LK SUP ON THU NGT. TEMPS COULD FALL QUICKLY IN
THE EVNG BEFORE MORE HI CLDS ASSOCIATED WITH DVLPG ISENTROPIC ASCENT
OVERSPREAD THE AREA W-E.
FRI INTO SAT...AS THE UPR TROF IN ERN NAMERICA SHIFTS TO THE E...THE
FLOW OVER THE CONUS/SRN CANADA WL BECOME MORE ZONAL. DVLPG LLVL SW
FLOW/ISENTROPIC ASCENT OVER THE GREAT LKS ON THE NW FLANK OF SFC HI
PRES SHIFTING INTO THE SRN MID ATLANTIC STATES THAT WL BE FORCING
THIS CHANGE IN THE UPR PATTERN IS PROGGED BY MOST OF THE MEDIUM
RANGE GUIDANCE IS FCST TO BRING ABOUT SOME INCRSG MID LVL MSTR/PCPN
ON FRI TO THE NE OF AN H85 WARM FNT STRETCHING FM THE NRN PLAINS
INTO MN. THE LATEST MODEL GUIDANCE HINTS THE HEAVIER PCPN ASSOCIATED
WITH THIS WARM AIR RETURN ON FRI MAY FALL TO THE SW IN WI. EXPECT
THE HIER POPS OVER THE ERN CWA WITH SW FLOW OF COLD AIR OFF LK MI
ALLOWING FOR SOME LES INTO THAT AREA ON FRI. AS A SHRTWV WITHIN THE
ZONAL FLOW SHIFTS EWD NEAR THE CNDN BORDER...A SFC LO PRES WL SHIFT
EWD AND JUST N OF LK SUP ON SAT. MOST OF THE GUIDANCE SHOWS H85
TEMPS RISING TO AOA 0C OVER AT LEAST THE S HALF OF THE CWA ON SAT...
INDICATING THE POTENTIAL FOR SOME MIXED PCPN. GFS FCST SDNGS SHOW AN
ELEVATED WARM LYR...SO INCLUDED A MENTION OF SOME FREEZING RA OVER
THE SCENTRAL WHERE THE WARM WEDGE H85 TEMPS ARE OVER 0C. THE MODELS
SUCH AS THE 12Z GFS AND ESPECIALLY THE 12Z CND THAT SHOW THE DEEPEST
SFC LO/FARTHER N TRACK ACTUALLY INDICATE UPR MI MIGHT SEE SOME DRY
SLOTTING AS THE H85 WARM FNT SHIFTS TO THE N OF THE CWA AND H85
TEMPS RISE AS HI AS 5-6C...SO POPS WL BE LOWEST OVER THE S.
SUN/MON...AS THE SHRTWV/SFC LO SHIFT INTO QUEBEC SAT NGT/SUN...
ATTENDANT COLD FNT WL SWING THRU UPR MI AND BRING A RETURN OF COLDER
AIR AND SOME LES FOR SUN. TRAILING HI PRES WL PASS TRHU THE CENTRAL
GREAT LKS ON SUN NGT...ENDING THIS LES. AS THE HI SHIFTS TOWARD NEW
ENGLAND...EXPECT A RETURN SW FLOW OF WARMER AIR TO DVLP ON MON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 239 PM EST MON NOV 24 2014
IFR TO LIFR CONDITIONS WILL PERSIST THIS AFTERNOON AS LAKE EFFECT
SNOW REDUCES VSBYS TO LESS THAN A MILE AT CMX/IWD. SAW STILL
MVFR...BUT EXPECT IFR CONDITIONS TO COMMENCE THERE AS WELL WHEN THE
BETTER LAKE EFFECT SNOW BANDS DEVELOP. IFR CONDITIONS WILL COTNINUE
THROUGH THE OVERNIGHT BEFORE IMPROVING TO MVFR ON TUESDAY AS DRIER
AIR MOVES IN. ALL SITES WILL ALSO SEE NORTH-NORTHEAST WINDS GUST TO
30+ KT THROUGH THIS EVENING CAUSING SOME BLSN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 PM EST MON NOV 24 2014
STRONG LOW PRESSURE NEAR SAULT STE MARIE JUST SOUTH OF JAMES BAY
WILL RAPIDLY MOVE INTO NRN QUEBEC TONIGHT. N-NW GALES WILL PERSIST
ACROSS THE LAKE TONIGHT...THEN SUBSIDE RATHER QUICKLY TUESDAY
MORNING. GENERALLY QUIET WEATHER EXPECTED FOR THE REMAINDER OF THE
WEEK...ALTHOUGH A LOW PRESSURE SYSTEM MOVING SOUTH OF THE LAKE WED
INTO WED NIGHT MAY ALLOW FOR N-NE WINDS TO GUST TO NEAR GALE FORCE.
HIGH PRESSURE BY THE WEEKEND SHOULD ALLOW FOR WINDS LESS THAN 20 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST TUESDAY FOR MIZ006-007-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY UNTIL 6 AM EST TUESDAY FOR MIZ001-003-
005>007.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 5 AM CST TUESDAY FOR MIZ012.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ246>251-265>267.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING UNTIL 9 PM EST /8 PM CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...KC
AVIATION...MRD
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
359 PM EST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 358 PM EST MON NOV 24 2014
COLD AIR IS RAPIDLY MOVING ACROSS UPPER MICHIGAN. MOST PLACES EXCEPT
THE FAR SOUTH AND EAST HAVE TURNED OVER TO SNOW AS 850MB TEMPS
RAPIDLY DROP TO -12C OR LOWER BEHIND THE SFC LOW. OTHER THAN NEAR
LAKE SUPERIOR...THE REST OF THE AREA IS UNDER A LULL OF
PRECIPITATION BEHIND THE FIRST UPPER DISTURBANCE RAPIDLY MOVING NE
INTO CANADA. HOWEVER...THE SECOND WAVE OF ENERGY CURRENTLY STILL
OVER THE IOWA AND SRN WI WILL MOVE TOWARD THE AREA THIS EVENING.
MODERATE MID LEVEL Q-VECTOR CONVERGENCE ALONG WITH MODERATE
850-700MB FRONTOGENETIC FORCING OWED TO THE MID LEVEL DEFORMATION
AXIS WILL MOVE ACROSS WI AND ACROSS THE FAR SOUTHERN PART OF THE
FORECAST AREA TONIGHT. THIS WILL ALLOW FOR A PERIOD OF SYSTEM SNOW
TO SPREAD ACROSS AREAS GENERALLY ALONG AND SOUTH OF U.S. 2 IN
MENOMINEE AND DELTA COUNTIES TONIGHT. RAPID UPDATE NWP SUGGEST UP TO
0.50 INCH OF LIQUID TONIGHT /WITH THE LATEST HRRR SUGGESTING UP TO
0.75 INCH/. BUT GIVEN THAT THE SYSTEM WILL BE MOVING FAIRLY FAST TO
THE NE AND 700MB SPECIFIC HUMIDITY VALUES ARE AT MOST 3 G/KM THIS
EVENING...AM EXPECTING QPF OF SLIGHTLY LESS THAN 0.50 INCH. WITH
SNOW RATIOS RISING TO 10-15:1 THIS EVENING...THIS WOULD SUGGEST THAT
FAR SOUTHERN MENOMINEE COUNTY COULD SEE 4-6 INCHES OF SNOW STARTING
LATE THIS AFTERNOON AND CONTINUING INTO OVERNIGHT. AS SUCH...HAVE
OPTED TO ISSUE A WINTER WEATHER ADVY FOR MENOMINEE COUNTY...FOCUSING
ON AREAS MAINLY SOUTH OF US 2. AM CURRENTLY THINKING THAT SYSTEM
PCPN WILL DIMINISH OVER A RELATIVELY SHORT DISTANCE TO THE
NORTH...SO AS OF NOW WILL LEAVE DICKINSON AND DELTA COUNTIES OUT OF
THE WINTER WEATHER ADVY.
AS FOR THE REMAINDER OF THE AREA...NO MAJOR CHANGES TO THE FORECAST
PLANNED. AS THE COLDER AIR MOVES ACROSS THE AREA THIS
EVENING...EXPECT BETTER LES BANDS TO DEVELOP IN THE N-NW
FLOW...SIMILAR TO WHAT IS OCCURRING AT IWD RIGHT NOW. CURRENT SNOW
RATIOS ARE FAIRLY LOW...GENERALLY 10-15:1 DUE TO THE SNOW GROWTH
REGION STILL FAIRLY HIGH. AS THE COLDER AIR MOVES IN...THE
EXPECTATION IS THAT THE SNOW RATIOS WILL BECOME HIGHER...CLOSER TO
20:1. AS SUCH...WILL MAINTAIN ALL LAKE EFFECT SNOW ADVISORIES AS
IS...WITH SIMILAR FORECAST AMOUNTS EXPECTED. STILL EXPECTING STORM
TOTAL OF 5-8 INCHES ACROSS THE GOGEBIC RANGE...4-7 INCHES
KEWEENAW...4-9 INCHES N-CENTRAL UPPER MI...AND 4-7 INCHES EAST OF
MARQUETTE. BLOWING SNOW NEAR LAKE SUPERIOR WILL STILL BE A PROBLEM
WITH SOME GUSTS IN EXCESS OF 30 MPH.
THE LES SHOULD GRADUALLY DIMINISH FROM WEST TO EAST LATE TONIGHT
INTO TUESDAY BEHIND THE UPPER TROUGH WHICH MOVES THROUGH LATE
TONIGHT. BEHIND THIS TROUGH...WEAK SFC RIDGING BUILDS IN ALONG WITH
BACKING PBL WINDS AND A DRIER AIRMASS ALLOWING FOR ANY REMAINING LES
TO SHIFT TO THE KEWEENAW AND ACROSS THE OPEN LAKE TUE AFTN. AS
SUCH...WILL MAINTAIN CHANCE POPS FOR THE ENTIRE DAY ACROSS THE
KEWEENAW BUT END THE POPS ACROSS THE FAR WEST. WILL MAINTAIN HIGHER
POPS EAST DUE TO W-NW FLOW HANGING ON FOR MUCH OF THE DAY THERE
ALONG WITH DEEPER MOISTURE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON NOV 24 2014
LIGHT TO MODERATE LAKE EFFECT WILL BE ONGOING TO START TUESDAY MORNING
WITH DELTA T/S OVER 15C AND NNW LOW-LEVEL WINDS IN WAKE OF THE
DEPARTING SFC LOW PRESSURE TROUGH. INVERSIONS UP TO 5KFT DOES PUT MOST
OF THE CLOUD BEARING LAYER IN THE DGZ...BUT WITH INCREASING DRYING
AND SUBSIDENCE ALOFT AS MAIN SHORTWAVE MOVES EAST...EXPECT THE LAKE EFFECT
TO DIMINISH THROUGH THE DAY AS LOW-LEVEL WINDS BECOME ANTICYCLONIC
AS RIDGE MOVES IN. ENDING TIMES FOR CURRENT LAKE EFFECT ADVISORIES
SEEM GOOD BASED ON THE DIMINISHING TRENDS IN SNOW SHOWERS AND WINDS/BLSN.
TUESDAY NIGHT INTO WEDNESDAY ONE SHORTWAVE AND A LOW PRESSURE SYSTEM
IS EXPECTED TO DIP ESE FM THE NORTHERN PLAINS TOWARD THE MIDDLE
MISSISSIPPI RIVER VALLEY. SWATH OF SNOW SHOULD ACCOMPANY THIS LOW
PRESSURE AREA AND THAT SHOULD STAY MAINLY SOUTH OF UPPER MICHIGAN.
INVERTED SFC TROUGH WILL BE PRESENT TO THE NORTH OF THE MAIN SFC LOW
AND THAT WOULD EXTEND INTO UPR MICHIGAN. SHORTWAVE LIKELY TO BE THE
MAIN FOCUS FOR THE WEATHER OVR CWA ON WEDNESDAY INTO THANKSGIVING IS
IN THE NORTHERN STREAM AND SLIDES OVER THE AREA FM SOUTHERN MANITOBA
AND NORTHWEST ONTARIO IN THE AFTN. OVERALL...PREFER THE OVERALL IDEA
OFFERED BY THE NAM/GFS/ECMWF COMPARED TO THE GEM-NH AS THAT MODEL
SEEMS TOO PHASED WITH THE NORTHERN STREAM AND SOUTHERN STREAM
SHORTWAVES WITH THE RESULT THAT THE THE MAIN SFC LOW IS TOO FAR
NORTH. ECMWF CONTINUES TO SHOW SHARPER TROUGH/CONVERGENCE AND LAKE
ENHANCED SNOW FOR NORTHWEST CWA NOT UNTIL WED NIGHT THEN OVER NCNTRL
CWA ON THANKSGIVING DAY. GFS CONTINUES TO INDICATE WEAKER OVERALL
SYSTEM BUT DOES BRING THE NORTH WIND LAKE EFFECT SNOW SHOWERS IN
EARLIER...MORE SO ON WEDNESDAY AFTN INTO WEDNESDAY NIGHT. GIVEN COLD
POOL OF AIR TO NORTH OF THE SFC TROUGH WITH H85 TEMPS DOWN TO AS LOW
AS -20C THERE WILL BE CERTAINLY BE SOME LAKE EFFECT SNOW SHOWERS
WEDNESDAY INTO THANKSGIVING. IN ADDITION...WILL NEED TO WATCH LAKE
EFFECT OFF LK MICHIGAN IN THE S/SE WINDS AHEAD OF THE SFC TROUGH.
WINDS BACK STEADILY FROM LATE TUESDAY NIGHT INTO WEDNESDAY OVER
NORTHERN LK MICHIGAN. FORECAST SOUNDINGS POINT TO SCT LAKE EFFECT TO
EXPAND OVER MUCH OF THE EASTERN CWA BY LATE WEDNESDAY AS THE ONSHORE
FLOW IS ENHANCED BY THE LARGER SCALE LIFT AND MOISTURE FM THE NEARING
NORTHERN STREAM SHORTWAVE.
SHARPNESS OF SFC TROUGH AND EXTENT OF CONVERGENCE STILL UNCERTAIN
THOUGH WHICH AFFECTS INTENSITY/EXTENT OF THE LES BOTH OFF LK
SUPERIOR AND LK MICHIGAN AND ALSO THE STRENGTH OF WINDS/BLSN NEAR LK
SUPERIOR IN WAKE OF TROUGH. LATEST RUNS OF GFS AND ECMWF KEEP WITH
CONTINUITY COMPARED TO THEIR PREVIOUS RUNS...GIVING NO TREND TO
LATCH ON. THOSE THAT HAVE TRAVEL PLANS WEDNESDAY INTO THANKSGIVING
NEAR LK SUPERIOR AND ALSO OVER MOST OF THE EAST HALF OF UPR MICHIGAN
SHOULD BE AWARE THAT DURING THIS TIME FRAME THERE COULD AT LEAST
LOCALIZED HIGHER IMPACT WEATHER.
HIGH PRESSURE DIVING OVER THE PLAINS WITH RIDGING OVER NORTHERN
ONTARIO EVENTUALLY SHOULD WIN OUT LATER ON THANKSGIVING. THOUGH IF
THE STRONGER TROUGH FM ECMWF IS CORRECT...DIMINISHING TREND IN THE
LAKE EFFECT WOULD BE MORE ON THURSDAY NIGHT. ONCE THE SFC RIDGE
SLIDES EAST ON FRIDAY...UPPER FLOW FLATTENS OUT ALLOWING FOR WARM
AIR ADVECTION TO RAMP UP OVER THE PLAINS. INDICATIONS THAT AT LEAST
ONE SHORTWAVE WILL ALSO BE PROPELLING FROM THE NORTHERN PLAINS
TOWARD THE WESTERN GREAT LAKES. DECENT JET STREAK ALSO FCST OVER THE
PLAINS WHICH SHOULD ENHANCED LIFT ALONG THE TIGHT LOW-LEVEL
BAROCLINIC ZONE. SWATH OF AT LEAST LIGHT SNOW SHOULD RESULT
SOMEWHERE VCNTY OF NORTHERN PLAINS TO THE WESTERN GREAT LAKES.
CONSIDERING THE WAVE THAT WILL GENERATE THE SNOW IS STILL TO EMERGE
FROM UPPER TROUGH OVER NORTHERN PACIFIC VCNTY OF 40N/155W...GFS IS
CONSISTENT IN SHOWING THIS AND GEM-NH IS THERE AS WELL. ECMWF JUST
TRENDED THIS WAY WITH THE 23NOV/12Z RUN. PLENTY OF TIME TO LOOK AT
THE DETAILS BUT DOES APPEAR THAT PTYPE WILL STAY ONLY SNOW AS WARM
AIR AT H85 IS FORECAST TO REMAIN SOUTHWEST OF UPPER LAKES.
MIXED SIGNALS THAT COULD SEE SOME LGT MIXED PRECIP FRIDAY NIGHT INTO
SATURDAY AS THE H9-H8 WARM LAYER ARRIVES. COULD SEE SOME DRIZZLE AND
FOG ISSUES TOO THOUGH AT LEAST RIGHT NOW...GFS/ECMWF ARE NOT SHOWING
DWPNTS AS HIGH AS ARE CURRENTLY OCCURRING OVER AREA. REAL MODEL
DIFFERENCES TO CLOSE THE LONG TERM...WITH 23NOV/12Z ECMWF KEEPING
THE WARM SECTOR OVER THE AREA INTO SUNDAY...WHILE THE GFS SHOVES
SHARPER COLD FRONT OVER THE UPPER GREAT LAKES BY SUNDAY. AT 12Z
SUNDAY...H85 TEMPS VARY FROM -5C OFF THAT RUN OF ECMWF TO -24C
OFF THE GFS. LATEST ECMWF TRENDED TOWARD GFS AS IT NOW SHOWS H85
TEMP THAT SAME TIME OF -16C. USED A CONSENSUS OF THE MODELS UNTIL
THE DIFFERENCES ARE RESOLVED...BUT GIVEN THE TREND FM THE LATEST
ECMWF...WENT WITH A BIT HIGHER POPS AND LOWERED TEMPS SLIGHTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 239 PM EST MON NOV 24 2014
IFR TO LIFR CONDITIONS WILL PERSIST THIS AFTERNOON AS LAKE EFFECT
SNOW REDUCES VSBYS TO LESS THAN A MILE AT CMX/IWD. SAW STILL
MVFR...BUT EXPECT IFR CONDITIONS TO COMMENCE THERE AS WELL WHEN THE
BETTER LAKE EFFECT SNOW BANDS DEVELOP. IFR CONDITIONS WILL COTNINUE
THROUGH THE OVERNIGHT BEFORE IMPROVING TO MVFR ON TUESDAY AS DRIER
AIR MOVES IN. ALL SITES WILL ALSO SEE NORTH-NORTHEAST WINDS GUST TO
30+ KT THROUGH THIS EVENING CAUSING SOME BLSN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 PM EST MON NOV 24 2014
STRONG LOW PRESSURE NEAR SAULT STE MARIE JUST SOUTH OF JAMES BAY
WILL RAPIDLY MOVE INTO NRN QUEBEC TONIGHT. N-NW GALES WILL PERSIST
ACROSS THE LAKE TONIGHT...THEN SUBSIDE RATHER QUICKLY TUESDAY
MORNING. GENERALLY QUIET WEATHER EXPECTED FOR THE REMAINDER OF THE
WEEK...ALTHOUGH A LOW PRESSURE SYSTEM MOVING SOUTH OF THE LAKE WED
INTO WED NIGHT MAY ALLOW FOR N-NE WINDS TO GUST TO NEAR GALE FORCE.
HIGH PRESSURE BY THE WEEKEND SHOULD ALLOW FOR WINDS LESS THAN 20 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST TUESDAY FOR MIZ006-007-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY UNTIL 6 AM EST TUESDAY FOR MIZ001-003-
005>007.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 5 AM CST TUESDAY FOR MIZ012.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ246>251-265>267.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING UNTIL 9 PM EST /8 PM CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...JLA
AVIATION...MRD
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
240 PM EST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 537 AM EST MON NOV 24 2014
WV IMAGERY AND RUC ANALYSIS SHOWS A MID-UPR LEVEL TROUGH OVER THE
NRN/CENTRAL PLAINS WITH A COUPLE OF STRONG SHORTWAVES OUT AHEAD OF
THIS TROUGH IN A SW FLOW. ONE SHORTWAVE WAS MOVING ACROSS LAKE HURON
NEARLY CO-LOCATED WITH THE 980 MB SFC LOW WHILE ANOTHER SHORTWAVE
WAS TRIGGERING THUNDERSTORMS AS IT LIFTED THROUGH SRN IL AND SRN IN.
DEFORMATION PCPN SHIELD IN COMMA HEAD OF LAKE HURON SHORTWAVE HAS
BEEN RESPONSIBLE FOR THE LIGHT PCPN OVER MUCH OF WEST AND CENTRAL
UPPER MI THIS MORNING WITH SOME MODERATE RAIN OVER ERN UPPER MI. THE
RAIN OVER THE EXISTING SNOW PACK CONTINUES TO SUPPORT AREAS OF FOG
BUT VSBYS OVER MOST AREAS HAVE RISEN ENOUGH TO CANCEL DENSE FOG
ADVISORY.
TODAY...MODELS AND REGIONAL RADAR IMAGERY SUGGEST THAT THERE MAY BE
A LULL IN THE PCPN BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID
LEVEL TROUGH MOVING IN FROM THE UPPER MS VALLEY/NRN PLAINS. AS THE
DEEPENING SFC LOW OVER LAKE HURON LIFTS QUICKLY NE THE COLDER AIR
WILL ALSO SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER
TO SNOW FROM 12Z-21Z FROM W TO EAST PER MODEL SNDGS AND 1000-850 MB
LOW-LVL LEVEL THICKNESS. WITH THE LOSS OF THE STRONGER LARGE SCALE
FORCING/DEEP LAYER Q-VECT CONVERGENCE TIL AFTERNOON EXPECT MAINLY
JUST LIGHT TO MODERATE LAKE ENHANCED SNOW OVER THE WEST HALF FOR NNW
FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO NEAR -8C WEST BY 18Z
AND TO AROUND -12C ACROSS WEST AND NCNTRL LOCATIONS BY 00Z. EXPECT
SNOWFALL AMOUNTS IN THE 2 TO 3 RANGE OVER THE WEST WITH GENERALLY
1-2 INCHES NCNTRL...EXCEPT UP TO 3 INCHES POSSIBLE OVER THE HURON
MOUNTAIN AREA. A TIGHT GRADIENT BEHIND THE LOW WILL BRING STRONG
NRLY WINDS WITH GUSTS TO 30-40 MPH PRODUCING SOME BLOWING AND
DRIFTING SNOW.
TONIGHT...MODELS CONTINUE TO SHOW DEEP MOISTURE/Q-VECTOR CONVERGENCE
AS MID-LVL TROUGH LINGERS OVER THE AREA. ALSO MODEL SOUNDINGS
SUGGEST THE POTENTIAL FOR GOOD SNOW GROWTH AT LEAST THIS EVENING AS
BEST MODEL OMEGA/LIFT INTERSECTS DGZ. CONVERGENT NNW FLOW WILL FAVOR
3-5 INCH ACCUMULATIONS OVER THE HIGHER TERRAIN OF THE WEST AND
NCNTRL COUNTIES WITH PERHAPS ISOLATED 6 INCH AMOUNTS POSSIBLE OVER
THE HURON MOUNTAINS. LAKE ENHANCED SNOW MAY TAPER OFF OVER THE WRN
COUNTIES LATE TONIGHT AS BEST FORCING/Q-VECT CONV BEGINS TO SHIFT
EAST.
CURRENT LAKE EFFECT SNOW ADVISORIES STILL ON TRACK FOR ALL OF WEST
AND NORTH CENTRAL UPPER MI WITH THE GREATEST SNOW TOTAL
ACCUMULATIONS OF 5 TO 9 INCHES EXPECTED OVER HIGHER TERRAIN
LOCATIONS NEAR LAKE SUPERIOR INTO TUESDAY. SOME ISOLATED 10" AMOUNTS
MAY BE POSSIBLE OVER THE HURON MOUNTAINS AIDED BY UPSLOPE FM THE
HIGHER TERRAIN THERE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON NOV 24 2014
LIGHT TO MODERATE LAKE EFFECT WILL BE ONGOING TO START TUESDAY MORNING
WITH DELTA T/S OVER 15C AND NNW LOW-LEVEL WINDS IN WAKE OF THE
DEPARTING SFC LOW PRESSURE TROUGH. INVERSIONS UP TO 5KFT DOES PUT MOST
OF THE CLOUD BEARING LAYER IN THE DGZ...BUT WITH INCREASING DRYING
AND SUBSIDENCE ALOFT AS MAIN SHORTWAVE MOVES EAST...EXPECT THE LAKE EFFECT
TO DIMINISH THROUGH THE DAY AS LOW-LEVEL WINDS BECOME ANTICYCLONIC
AS RIDGE MOVES IN. ENDING TIMES FOR CURRENT LAKE EFFECT ADVISORIES
SEEM GOOD BASED ON THE DIMINISHING TRENDS IN SNOW SHOWERS AND WINDS/BLSN.
TUESDAY NIGHT INTO WEDNESDAY ONE SHORTWAVE AND A LOW PRESSURE SYSTEM
IS EXPECTED TO DIP ESE FM THE NORTHERN PLAINS TOWARD THE MIDDLE
MISSISSIPPI RIVER VALLEY. SWATH OF SNOW SHOULD ACCOMPANY THIS LOW
PRESSURE AREA AND THAT SHOULD STAY MAINLY SOUTH OF UPPER MICHIGAN.
INVERTED SFC TROUGH WILL BE PRESENT TO THE NORTH OF THE MAIN SFC LOW
AND THAT WOULD EXTEND INTO UPR MICHIGAN. SHORTWAVE LIKELY TO BE THE
MAIN FOCUS FOR THE WEATHER OVR CWA ON WEDNESDAY INTO THANKSGIVING IS
IN THE NORTHERN STREAM AND SLIDES OVER THE AREA FM SOUTHERN MANITOBA
AND NORTHWEST ONTARIO IN THE AFTN. OVERALL...PREFER THE OVERALL IDEA
OFFERED BY THE NAM/GFS/ECMWF COMPARED TO THE GEM-NH AS THAT MODEL
SEEMS TOO PHASED WITH THE NORTHERN STREAM AND SOUTHERN STREAM
SHORTWAVES WITH THE RESULT THAT THE THE MAIN SFC LOW IS TOO FAR
NORTH. ECMWF CONTINUES TO SHOW SHARPER TROUGH/CONVERGENCE AND LAKE
ENHANCED SNOW FOR NORTHWEST CWA NOT UNTIL WED NIGHT THEN OVER NCNTRL
CWA ON THANKSGIVING DAY. GFS CONTINUES TO INDICATE WEAKER OVERALL
SYSTEM BUT DOES BRING THE NORTH WIND LAKE EFFECT SNOW SHOWERS IN
EARLIER...MORE SO ON WEDNESDAY AFTN INTO WEDNESDAY NIGHT. GIVEN COLD
POOL OF AIR TO NORTH OF THE SFC TROUGH WITH H85 TEMPS DOWN TO AS LOW
AS -20C THERE WILL BE CERTAINLY BE SOME LAKE EFFECT SNOW SHOWERS
WEDNESDAY INTO THANKSGIVING. IN ADDITION...WILL NEED TO WATCH LAKE
EFFECT OFF LK MICHIGAN IN THE S/SE WINDS AHEAD OF THE SFC TROUGH.
WINDS BACK STEADILY FROM LATE TUESDAY NIGHT INTO WEDNESDAY OVER
NORTHERN LK MICHIGAN. FORECAST SOUNDINGS POINT TO SCT LAKE EFFECT TO
EXPAND OVER MUCH OF THE EASTERN CWA BY LATE WEDNESDAY AS THE ONSHORE
FLOW IS ENHANCED BY THE LARGER SCALE LIFT AND MOISTURE FM THE NEARING
NORTHERN STREAM SHORTWAVE.
SHARPNESS OF SFC TROUGH AND EXTENT OF CONVERGENCE STILL UNCERTAIN
THOUGH WHICH AFFECTS INTENSITY/EXTENT OF THE LES BOTH OFF LK
SUPERIOR AND LK MICHIGAN AND ALSO THE STRENGTH OF WINDS/BLSN NEAR LK
SUPERIOR IN WAKE OF TROUGH. LATEST RUNS OF GFS AND ECMWF KEEP WITH
CONTINUITY COMPARED TO THEIR PREVIOUS RUNS...GIVING NO TREND TO
LATCH ON. THOSE THAT HAVE TRAVEL PLANS WEDNESDAY INTO THANKSGIVING
NEAR LK SUPERIOR AND ALSO OVER MOST OF THE EAST HALF OF UPR MICHIGAN
SHOULD BE AWARE THAT DURING THIS TIME FRAME THERE COULD AT LEAST
LOCALIZED HIGHER IMPACT WEATHER.
HIGH PRESSURE DIVING OVER THE PLAINS WITH RIDGING OVER NORTHERN
ONTARIO EVENTUALLY SHOULD WIN OUT LATER ON THANKSGIVING. THOUGH IF
THE STRONGER TROUGH FM ECMWF IS CORRECT...DIMINISHING TREND IN THE
LAKE EFFECT WOULD BE MORE ON THURSDAY NIGHT. ONCE THE SFC RIDGE
SLIDES EAST ON FRIDAY...UPPER FLOW FLATTENS OUT ALLOWING FOR WARM
AIR ADVECTION TO RAMP UP OVER THE PLAINS. INDICATIONS THAT AT LEAST
ONE SHORTWAVE WILL ALSO BE PROPELLING FROM THE NORTHERN PLAINS
TOWARD THE WESTERN GREAT LAKES. DECENT JET STREAK ALSO FCST OVER THE
PLAINS WHICH SHOULD ENHANCED LIFT ALONG THE TIGHT LOW-LEVEL
BAROCLINIC ZONE. SWATH OF AT LEAST LIGHT SNOW SHOULD RESULT
SOMEWHERE VCNTY OF NORTHERN PLAINS TO THE WESTERN GREAT LAKES.
CONSIDERING THE WAVE THAT WILL GENERATE THE SNOW IS STILL TO EMERGE
FROM UPPER TROUGH OVER NORTHERN PACIFIC VCNTY OF 40N/155W...GFS IS
CONSISTENT IN SHOWING THIS AND GEM-NH IS THERE AS WELL. ECMWF JUST
TRENDED THIS WAY WITH THE 23NOV/12Z RUN. PLENTY OF TIME TO LOOK AT
THE DETAILS BUT DOES APPEAR THAT PTYPE WILL STAY ONLY SNOW AS WARM
AIR AT H85 IS FORECAST TO REMAIN SOUTHWEST OF UPPER LAKES.
MIXED SIGNALS THAT COULD SEE SOME LGT MIXED PRECIP FRIDAY NIGHT INTO
SATURDAY AS THE H9-H8 WARM LAYER ARRIVES. COULD SEE SOME DRIZZLE AND
FOG ISSUES TOO THOUGH AT LEAST RIGHT NOW...GFS/ECMWF ARE NOT SHOWING
DWPNTS AS HIGH AS ARE CURRENTLY OCCURRING OVER AREA. REAL MODEL
DIFFERENCES TO CLOSE THE LONG TERM...WITH 23NOV/12Z ECMWF KEEPING
THE WARM SECTOR OVER THE AREA INTO SUNDAY...WHILE THE GFS SHOVES
SHARPER COLD FRONT OVER THE UPPER GREAT LAKES BY SUNDAY. AT 12Z
SUNDAY...H85 TEMPS VARY FROM -5C OFF THAT RUN OF ECMWF TO -24C
OFF THE GFS. LATEST ECMWF TRENDED TOWARD GFS AS IT NOW SHOWS H85
TEMP THAT SAME TIME OF -16C. USED A CONSENSUS OF THE MODELS UNTIL
THE DIFFERENCES ARE RESOLVED...BUT GIVEN THE TREND FM THE LATEST
ECMWF...WENT WITH A BIT HIGHER POPS AND LOWERED TEMPS SLIGHTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 239 PM EST MON NOV 24 2014
IFR TO LIFR CONDITIONS WILL PERSIST THIS AFTERNOON AS LAKE EFFECT
SNOW REDUCES VSBYS TO LESS THAN A MILE AT CMX/IWD. SAW STILL
MVFR...BUT EXPECT IFR CONDITIONS TO COMMENCE THERE AS WELL WHEN THE
BETTER LAKE EFFECT SNOW BANDS DEVELOP. IFR CONDITIONS WILL COTNINUE
THROUGH THE OVERNIGHT BEFORE IMPROVING TO MVFR ON TUESDAY AS DRIER
AIR MOVES IN. ALL SITES WILL ALSO SEE NORTH-NORTHEAST WINDS GUST TO
30+ KT THROUGH THIS EVENING CAUSING SOME BLSN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 537 AM EST MON NOV 24 2014
A DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR TODAY. NORTHERLY
WINDS WILL INCREASE TO GALES 35-45 KTS BY THIS MORNING INTO MONDAY
NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS WED NIGHT INTO THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
THERE MAY BE A BRIEF PD OF GALES TO 35 KNOTS OVER NCNTRL LAKE
SUPERIOR WED NIGHT. WINDS WILL DECREASE TO LESS THAN 25 KNOTS THU
NIGHT INTO FRI AS A HIGH PRES RIDGE MOVES OVER THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST TUESDAY FOR MIZ006-007-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY UNTIL 6 AM EST TUESDAY FOR MIZ001-003-
005>007.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ246>250-265-266.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING UNTIL 9 PM EST /8 PM CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...MRD
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
ISSUED BY NATIONAL WEATHER SERVICE LA CROSSE WI
249 PM CST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 249 PM CST MON NOV 24 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT TROUGH COMING INTO CENTRAL BRITISH COLUMBIA ON TOP
OF EAST PACIFIC RIDGING...AND MORE TROUGHING COVERING MUCH OF
CENTRAL NORTH AMERICA. WITHIN THIS BROAD TROUGH...A SHORTWAVE WAS
PRESENT OVER EASTERN IOWA/NORTHERN IL...WHICH DPVA FROM IT COMBINED
WITH A BAND OF MID LEVEL FRONTOGENESIS HAS ALLOWED A BAND OF SNOW TO
PERSIST FROM WESTERN INTO SOUTHERN WI. ADDITIONAL SNOW SHOWERS HAVE
BEEN TAKING PLACE ACROSS MUCH OF MN INTO IA...MOSTLY ASSOCIATED WITH
INSTABILITY PRODUCED FROM COOL MID LEVEL TEMPS ALOFT AND RELATIVELY
WARMER TEMPS/DEWPOINTS AT THE SURFACE. RAP 700MB TEMPS SHOWED
READING IN THE -12 TO -13C RANGE...MEANWHILE SURFACE TEMPS HAVE
COOLED INTO THE TEENS AND 20S...WARMEST IN WESTERN WI. A TIGHT
PRESSURE GRADIENT IN PLACE...BETWEEN A SURFACE RIDGE OVER THE
WESTERN PLAINS AND A LOW PRESSURE TROUGH IN NORTHERN LOWER MI...HAS
PRODUCED GUSTS OF 30-40 MPH. THE STRONGEST GUSTS HAVE BEEN CONFINED
TO SOUTHWEST AND SOUTH CENTRAL MN WHERE THE DEEPEST MIXING HAS BEEN
TAKING PLACE. FARTHER TO THE WEST...A LARGE EXPANSE OF CLEARING
DOMINATES A LOT OF THE PLAINS...ASSOCIATED WITH THE SURFACE RIDGE
AND VERY DRY AIR. PRECIPITABLE WATER VALUES THERE ARE IN THE 0.1-0.2
INCH RANGE.
THE FOCUS FOR ATTENTION BEGINS TO SHIFT TO THAT POTENT TROUGH OVER
CENTRAL BRITISH COLUMBIA. GOOD MODEL CONSENSUS EXISTS FOR THE TROUGH
TO DIG DOWN INTO THE WESTERN DAKOTAS BY 00Z WEDNESDAY...ALLOWING
WEAK RIDGING TO BUILD OVER THE FORECAST AREA. ADDITIONALLY...THE
NEXT POTENT TROUGH WILL HELP PUSH THE CURRENT SHORTWAVE TROUGH AND
700MB COOL AIR SITUATED OVER THE FORECAST AREA OFF TO THE EAST.
FOR TONIGHT...ANTICIPATING SNOW SHOWERS OVER MINNESOTA TO DIMINISH
QUICKLY THIS EVENING WITH LOSS OF DAYTIME HEATING. FIGURE
SOMEWHERE AROUND 03Z THEY SHOULD HAVE ENDED...IN AGREEMENT WITH A
LOT OF HI RESOLUTION MODEL GUIDANCE. THE SNOW OVER WESTERN WI WILL
TAKE LONGER TO END BEING ASSOCIATED WITH THE MID LEVEL
FRONTOGENESIS BAND THERE...SOMEWHERE AROUND 06Z. CURRENT WINTER
WEATHER ADVISORY END TIME STILL LOOKS GOOD. REGARDING THE WIND
ADVISORY...PRESENT WINDS ARE MARGINAL TO KEEP IT GOING.
HOWEVER...SINCE CONDITIONS REMAIN BRISK FOR THE REST OF THE
AFTERNOON AND WINDS ARE STILL ON TRACK TO DIMINISH THIS
EVENING...PLAN ON LETTING THE WIND ADVISORY EXPIRE AT 6 PM. CLEARING
ACROSS THE PLAINS SHOULD MAKE ITS WAY WEST TO EAST ACROSS A LOT OF
THE FORECAST AREA...PERHAPS EVEN INTO WESTERN WI BY 12Z. THE
CLEARING COMBINED WITH A WEAKENING PRESSURE GRADIENT AND ALREADY
COOL TEMPERATURES SHOULD ALLOW READINGS TO DIP INTO THE SINGLE
DIGITS OVER WEST-CENTRAL MN. TEENS ARE LIKELY ELSEWHERE WITH MORE
CLOUDS AND WIND. IT SHOULD BE NOTED THAT MORE CLOUDS ARE LIKELY TO
COME INTO WESTERN SECTIONS OF THE FORECAST AREA BY 12Z...AHEAD OF
THE APPROACHING POTENT TROUGH.
ON TUESDAY...CLOUDS WILL MARCH THEIR WAY WEST TO EAST ACROSS THE
FORECAST AREA AGAIN AS THE POTENT TROUGH MOVES INTO THE WESTERN
DAKOTAS. ANY PRECIPITATION DOES LOOK TO REMAIN TO THE WEST PRIOR TO
00Z WEDNESDAY...THOUGH. ALTHOUGH THERE MIGHT BE MORE CLOUDS...
INCREASING SOUTHWESTERLY FLOW AHEAD OF THE AFTERNOON SHOULD HELP
GIVE TEMPERATURES A BOOST. IN FACT...925MB READINGS CLIMB FROM
AROUND -10C AT 12Z TO -4 TO -7C BY 00Z...WARMEST NEAR MANKATO AND
NEW ULM. MOST LOCATIONS SHOULD SEE HIGHS IN THE 20S...WITH 30S
POSSIBLE NEAR THE MN RIVER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 249 PM CST MON NOV 24 2014
MAIN FOCUS STARTING OFF THE PERIOD IS THE POTENT SHORTWAVE TROUGH
CURRENTLY IN CENTRAL BRITISH COLUMBIA. THERE HAS BEEN A MAJOR TREND
OVER THE PAST 2 DAYS TO DIG THIS TROUGH FARTHER SOUTHWEST...
ESPECIALLY IN THE ECMWF. THIS TREND APPEARS TO BE RELATED TO THE
CURRENT CENTRAL NORTH AMERICA TROUGH BEING MORE AMPLIFIED THAN
PREVIOUSLY PROGGED. AS A RESULT OF THIS TREND...THERE IS A CHANCE
SUGGESTED BY THE 24.12Z GFS THAT MUCH OF THE AREA COULD BE MISSED BY
THIS SYSTEM. THIS WOULD BE GOOD NEWS FOR TRAVELERS. IN THE GFS...THE
SHORTWAVE TROUGH AND ITS ASSOCIATED SURFACE LOW DIVE DOWN TO NEAR
THE KANSAS CITY AREA BY 12Z...WITH THE ISENTROPIC LIFT/MID LEVEL
FRONTOGENESIS ZONE BRUSHING THE MN RIVER VALLEY WITH SOME SNOW
BETWEEN 06-18Z WEDNESDAY. HAVE TRENDED THE FORECAST DRIER TO ACCOUNT
FOR THE MODEL TREND...BUT QPF AND POPS MAY NEED TO BE REDUCED
FURTHER. TEMPERATURES SHOULD NOT DROP MUCH TUESDAY NIGHT WITH THE
CLOUDS IN PLACE AND EVEN SOME SLIGHT WARM ADVECTION POSSIBLE. FOR
WEDNESDAY...HIGHS ARE LIKELY TO OCCUR BY NOON AS COLD ADVECTION
LOOKS TO COMMENCE IN THE WAKE OF THE TROUGH. THE AMOUNT OF ADVECTION
DEPENDS ON HOW FAR SOUTH THE TROUGH DIGS...THUS THESE READINGS ARE
SUBJECT TO CHANGE.
DRY AND COLDER CONDITIONS REMAIN PROGGED TO AFFECT THE AREA FOR
WEDNESDAY NIGHT AND THANKSGIVING...AS ARCTIC HIGH PRESSURE MOVES IN
FROM THE NORTHWEST. 925MB TEMPS TOPPING OUT IN THE -10 TO -16C RANGE
WILL ONLY ALLOW FOR HIGHS IN THE TEENS.
A PATTERN CHANGE IS IN THE OFFERING FOR THURSDAY NIGHT INTO EARLY
NEXT WEEK WITH MODELS ADVERTISING A SERIES OF TROUGHS MOVING INTO
THE WESTERN U.S.. THIS RESULTS IN A MORE ZONAL FLOW PATTERN
DOWNSTREAM TO EVENTUALLY SOUTHWESTERLY EARLY NEXT WEEK. THE SWITCH
TO ZONAL FLOW RESULTS IN A WARM ADVECTION REGIME THURSDAY NIGHT AND
FRIDAY. ON THE NOSE OF THE WARM ADVECTION...A MID-LEVEL
FRONTOGENESIS SNOWFALL BAND LOOKS TO SETUP FROM THE DAKOTAS THROUGH
MINNESOTA AND WISCONSIN. EXACT PLACEMENT AND AMOUNTS ARE YET TO BE
DETERMINED...BUT THE FOCUS RIGHT NOW GENERALLY APPEARS ALONG/NORTH
OF I-94. THE WARM FRONT LOOKS TO LIFT THROUGH MUCH OF THE FORECAST
AREA FRIDAY NIGHT. THEN FOR SATURDAY...A SHORTWAVE CROSSES THE AREA
IN THE ZONAL FLOW...SENDING A COLD FRONT THROUGH. THIS PERIOD COULD
BE TRICKY FOR HIGHS. IF THE FRONT IS SLOWER...HIGHS COULD EASILY TOP
OUT IN THE 40S. HOWEVER...AT THE CURRENT SPEED...UPPER 20S TO MID
30S SEEM MORE REASONABLE. DESPITE THE ZONAL FLOW...AN ARCTIC LOW
LEVEL INTRUSION LOOKS TO AFFECT THE AREA FOR SATURDAY NIGHT AND
SUNDAY...ACCOMPANIED BY ARCTIC HIGH PRESSURE...NOTED BY 925MB TEMPS
ABOUT 5C COLDER THAN AT 850MB. THOSE 925MB TEMPS ON SUNDAY RANGING
FROM -10 TO -15C MEANS BACK TO HIGHS IN THE TEENS. WE SHOULD BEGIN
TO DISLODGE THE COLD AIR ON MONDAY WITH THE UPPER FLOW TURNING
SOUTHWESTERLY...ALLOWING FOR A REBOUND BACK INTO THE 20S FOR HIGHS.
CONDITIONS LOOK TO REMAIN DRY FOR MONDAY WITH ARCTIC HIGH PRESSURE
IN PLACE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1137 AM CST MON NOV 24 2014
MIX OF CONDITIONS TODAY AS DEFORMATION SNOW BAND CONTINUES TO IMPACT
WESTERN WISCONSIN WITH SNOW SHOWERS AND STRONG NORTHWEST WINDS
IMPACTING MINNESOTA. MVFR AND IFR CONDITIONS PREVAIL.
POCKET OF STEEPER LAPSE RATES PRODUCING CONVECTIVE SNOW SHOWERS
ACROSS CENTRAL MINNESOTA WILL CONTINUE TO SHIFT SOUTH AND SOUTHEAST
AROUND UPPER SYSTEM WITH OTHER AREAS OF LIGHT SNOW MOVING SOUTH AS
WELL. WILL HAVE TO ACCOUNT FOR OCCASIONAL LOWER VISIBILITIES THIS
AFTERNOON YET BEFORE SYSTEM EXITS TO THE EAST...ALTHOUGH CEILINGS
RELATIVELY STABLE.
SHORT BREAK BEHIND THIS SYSTEM SO WILL ATTEMPT TO TIME CLEARING IN
FROM THE WEST...ALBEIT DELAYED A LITTLE FROM EARLIER TRENDS.
MEANWHILE ANOTHER SHORT WAVE TROUGH ENTERS THE PICTURE QUICKLY
TUESDAY SO WILL SEE INCREASE IN CLOUDS IN WESTERN MINNESOTA TOWARDS
LATTER PART OF FORECAST...WITH VFR CONDITIONS.
KMSP...
MSP BETWEEN SNOW SHOWERS TO THE WEST AND DEFORMATION SNOW
AREA AREA TO THE EAST. THESE MVFR CONDITIONS WILL GIVE WAY TO LIGHT
SNOW SPREADING IN FROM THE NORTH THIS AFTERNOON WHICH COULD CREATE
POCKETS OF IFR. BY EVENING SYSTEM SHOULD PUSH FAR ENOUGH EAST
LEAVING JUST MVFR CEILINGS WITH SLOW BREAK UP IN CLOUDS FROM WEST TO
EAST OVERNIGHT. WINDS WILL ALSO BEGIN TO DECREASE OUT OF THE
NORTHWEST AND BACK TO MORE SOUTHWEST DIRECTION ON TUESDAY...AHEAD OF
NEXT WAVE.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS W 5-10 KT BECOMING SE.
WED...MVFR/IFR CHC -SN EARLY. WINDS NW 10-15KTS.
THU...VFR. WINDS LIGHT/VARIABLE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ054>056-064-065-
073>075-082>084-091>093.
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ016-
026>028.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...SHEA
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1138 AM CST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 529 AM CST MON NOV 24 2014
...NW WINDS GUST 35-40 MPH WITH ISOLATED G45 WITH DIMINISHING
CLOUDS IN MOSTLY COLDER THAN NORMAL TEMPS...
ALOFT: THE NEWLY REESTABLISHED LONGWAVE TROF AXIS WAS SHIFTING E
OF THE FCST AREA. BACK TO NW FLOW THRU TONIGHT. THE NEXT SHORTWAVE
TROF TO AFFECT THE FCST AREA WAS OVER BRITISH COLUMBIA. THIS TROF
WILL PASS THRU HERE TONIGHT WITH ONLY AN INCREASE IN HIGH CLOUDS.
SURFACE: THE FCST AREA WAS IN THE COLD SECTOR OF DEEP LOW PRES
OVER THE GREAT LAKES THIS MORNING. WE WILL REMAIN IN THE COLD
SECTOR THRU TONIGHT. WRN USA HIGH PRES WILL GRADUALLY BUILD IN
WITH CYCLONIC BOUNDARY LAYER FLOW BECOMING ANTICYCLONIC. ITS RIDGE
AXIS WILL PASS THRU AFTER MIDNIGHT. A CLIPPER WILL FORM OVER WRN
CANADA TONIGHT AND AN ASSOCIATED WARM FRONT WILL DEVELOP SOUTHWARD
INTO THE REGION.
529 AM: LOTS OF WRAP AROUND CLOUDS IN CYCLONIC NW FLOW...N AND E
OF THE TRI-CITIES. STILL CANT RULE OUT A STRAY FLURRY ALTHOUGH
HAVE NOT SEEN ANY IN REGIONAL OBS RECENTLY.
BBW MEASURED A G39 KTS AT 421 AM. THAT IS INDICATIVE OF WHAT OUR
MAX WIND POTENTIAL IS TODAY ONCE CONVECTIVE MIXING COMMENCES.
TODAY: CONTINUED WINDY. NW WINDS WILL GUST 30-35 KTS IN DOWNWARD
TRANSFER AS THE BOUNDARY LAYER BECOMES UNSTABLE. POTENTIAL PEAK
GUSTS AS HIGH AS 40 KTS PER BUFKIT MIXING ALGORITHM. USED GFS
WITH ITS DEEPER MIXING.
THE RAP/NAM/GFS AGREE THE WRN FRINGE OF THE WRAP-AROUND CLOUDS
WILL GRADUALLY SHIFT E OF THE FCST AREA LEAVING SKIES SUNNY.
SIMULATED IR IMAGERY FROM THE 4 KM NAM NEST SUGGESTS SOME PATCHES
OF CIRROSTRATUS WILL BEGIN MOVING IN FROM THE NW LATE AND THIS
IS REASONABLE BASED ON CURRENT SATELLITE...WITH THE NRN ROCKIES
SHORTWAVE TROF DIVING TO OUR W.
INTERNAL VERIFICATION SHOWS WE HAVE BEEN RUNNING TOO COOL ON HIGH
TEMPS RECENTLY. SO USED 06Z RAP TO NUDGE TEMPS UPWARD SLIGHTLY.
HIGHS WILL STILL BE 5-10F COLDER THAN NORMAL FOR MOST OF THE FCST
AREA.
TONIGHT: WINDS DROP OFF EARLY EVENING WITH DECOUPLING. PATCHES OF
CIRROSTRATUS CONT TO DRIFT THRU BUT SHOULD BE NO WORSE THAN
P/CLOUDY.
USED THE WEIGHTED CONSENSUS OF THE 3 BEST-VERIFYING TEMP GUIDES
FOR LOWS...WHICH FAVORED THE COLDER MOS TEMPS. JUST SLIGHTLY
COLDER THAN NORMAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 407 AM CST MON NOV 24 2014
THE BIG HOLIDAY WEEKEND IS FAST APPROACHING AND NO TRAVEL
PROBLEMS ARE EXPECTED ACROSS NEBRASKA AND KANSAS. ALWAYS REMEMBER
YOU CAN CHECK WWW.WEATHER.GOV FOR THE LATEST WEATHER CONDITIONS
AND FORECAST FOR ANYWHERE IN THE COUNTRY WHERE YOU MIGHT BE
TRAVELING TO THIS HOLIDAY WEEKEND.
THE BIGGEST CONCERN FOR OUR AREA DURING THE HOLIDAY WEEKEND WILL
CENTER AROUND SEVERAL BIG TEMPERATURE SWINGS.
TUESDAY...THIS SHOULD BE A WARMER DAY WITH LIGHTER WINDS. THE
STRONG NORTHWEST WIND OF SUNDAY AND MONDAY WILL GIVE WAY TO A MORE
GENTLE SOUTHWESTERLY BREEZE THAT WILL HELP TO WARM HIGHS INTO THE
MID AND UPPER 40S ACROSS MOST NEBRASKA ZONES TO THE LOWER 50S
ACROSS PORTIONS OF NORTHERN KANSAS. THERE ARE SOME MODEL
DIFFERENCES WITH THE 00Z GFS TRYING TO BRING THE NEXT COLD FRONT
INTO NEBRASKA ZONES BY TUESDAY AFTERNOON ALONG WITH SOME SPRINKLES
AND SLIGHTLY COOLER AIR. HOWEVER...THE 00Z NAM AND 00Z GFS ARE
BOTH SLOWER WITH THE COLD FRONT AND ARE DRY. THIS FORECAST LEANS
TOWARDS THE ECMWF/NAM SOLUTION.
TUESDAY NIGHT INTO WEDNESDAY...COOLER AIR WILL FILTER INTO OUR
REGION BEHIND A COLD FRONT. WE CAN NOT RULE OUT A FLURRY OR
TWO...BUT GIVEN MOST FORECAST MODELS ARE COMPLETELY DRY...WE WILL
KEEP THE FORECAST DRY AND WITHHOLD ANY FLURRIES FOR NOW. FORECAST
MODELS ARE NOT AS COLD WITH THIS AIRMASS AS THEY WERE SEVERAL DAYS
AGO AND EXPECT HIGHS ON WEDNESDAY SHOULD STILL REACH THE UPPER 30S
ACROSS NORTHEASTERN ZONES TO THE MID 40S OVER NORTH CENTRAL
KANSAS.
THANKSGIVING...UNFORTUNATELY THE HOLIDAY ITSELF APPEARS TO THE BE
COLDEST DAY OF THE WEEKEND AS THE COOLER AIR THAT SETTLES IN ON
WEDNESDAY MAY HANG AROUND THROUGH THANKSGIVING DAY.
HOWEVER...FORECAST MODELS HAVE BEEN TRENDING WARMER AND SO WOULD
NOT BE SURPRISED IF OUR FORECAST HIGHS ON THANKSGIVING DAY
EVENTUALLY GET RAISED SOME. FOR NOW WILL CONTINUE TO GO WITH THE
OVERALL SUPERBLEND OF MODELS...WHICH RESULTS IN HIGHS IN THE MID
30S IN THE TRI-CITIES...TO THE LOWER AND MID 40S OVER NORTHERN
KANSAS.
FRIDAY THROUGH SUNDAY...THE OVERALL UPPER FLOW BECOMES MORE ZONAL
WITH THE REAL COLD AIR BOXED UP IN CANADA. THIS WILL ALSO KEEP THE
STORM TRACK WELL TO OUR NORTH RESULTING IN CONTINUED DRY
CONDITIONS. THERE IS GOOD CONFIDENCE IN FRIDAY BEING A VERY NICE
DAY WITH HIGHS LIKELY AROUND 50 IN THE TRI-CITIES TO THE MID AND
UPPER 50S OVER NORTH CENTRAL KANSAS WITH JUST A LIGHT SOUTHWEST
WIND. SATURDAY IS MUCH MORE UNCERTAIN WITH A COLD FRONT ON OUR
DOOR STEP. THE LATEST 00Z ECMWF IS SLOWER WITH THE COLD FRONT AND
INDICATES THAT HIGHS ON SATURDAY MAY BE EVEN WARMER THAN ON FRIDAY
POSSIBLY REACHING INTO THE 60S...BUT THE 00Z GFS IS MUCH QUICKER
WITH THE COLD FRONT AND WOULD HAVE TEMPERATURES FALLING THROUGH
THE 30S SATURDAY AFTERNOON. OUR OFFICIAL FORECAST IS CURRENTLY
SOMEWHERE IN THE MIDDLE WITH A HIGH DEGREE OF UNCERTAINTY AT THIS
TIME. CONFIDENCE REALLY DOES NOT IMPROVE MUCH ON SUNDAY AS THERE
IS UNCERTAINTY WITH REGARD TO HOW COLD THE NEXT AIR MASS WILL BE.
THE 00Z GFS AND 00Z ECMWF HAVE BOTH TRENDED DOWNWARD AND WOULD
RESULT IN HIGHS ONLY IN THE 20S ON SUNDAY WHILE OUR FORECAST STILL
IS INCORPORATING RECENT RUNS THAT WERE WARMER AND IS CALLING FOR
HIGHS IN THE 30S AND 40S. BASICALLY...EXPECT FORECAST CHANGES IN
THE COMING DAYS AS THE UNCERTAINTY ISSUES GET IRONED OUT.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1125 AM CST MON NOV 24 2014
GUSTY NORTHWEST WILL BE THE MAIN CONCERN FOR THE TAF PERIOD
THROUGH THE AFTERNOON HOURS. NORTHWEST WINDS OF 20 TO 25KTS AND
GUSTS OF 30KTS ARE FORECAST UNTIL THE GRADIENT RELAXES THIS
EVENING. CLOUD COVER IS EXPECTED TO THICKEN TOWARD TUESDAY MORNING
AND HAVE KEPT CIGS AT VFR.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
113 PM EST MON NOV 24 2014
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP EAST ACROSS THE REGION TODAY...BRINGING
SHOWERS ALONG WITH WINDY CONDITIONS. MUCH COLDER AIR WILL RUSH IN
BEHIND THE FRONT AND WILL LINGER FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FCST FOCUS TODAY REVOLVES AROUND STRONG WINDS AND CONVECTION THIS
MORNING. STRONG SFC LOW OVER THE NRN GREAT TO CONTINUE TO DEEPEN
AS IT TRACKS NE INTO SRN CANADA. 60 KT SWRLY LLJ PIVOTING THRU
THE AREA TODAY. RAP SHOWING BLYR CAPE OF 350 J/KG ACRS W CENTRAL
OHIO EARLY THIS MORNING. THIS MARGINAL INSTBY AHD OF SFC COLD FRONT
COMBINED WITH THE STRONG DYNAMICS HAS LED TO THE DEVELOPMENT OF A
BROKEN LINE OF CONVECTION. SOME OF THE STORMS WERE TRANSLATING
WINDS UP TO 45 KTS TO THE SFC. AN ISOLATED SVR WIND GUST OF 50 KTS
OR GREATER IN A STRONGER STORM CAN NOT BE RULED OUT.
THIS MARGINAL INSTBY WEAKENS AND PIVOTS TO THE NE THIS MORNING.
CURRENT FCST HAS GOOD HANDLE TAKING THIS CHANCE OF THUNDER EAST
AND THEN DIMINISHING.
SFC PRESSURE GRADIENT TIGHTENS WITH FROPA IN STRONG CAA THIS
MORNING INTO EARLY AFTERNOON. 50 TO 60 KT LOW LEVEL WILL GET
PULLED DOWN IN THE POST FRONTAL COLD ADVECTION. HAVE INCREASED
SUSTAINED WINDS AND BUMPED UP GUSTS INTO THE UPPER 40 KT RANGE.
EXPECT WINDS TO BE IN THE HIGH END WIND ADVISORY RANGE. THEREFORE...
HAVE KEPT CURRENT WIND ADVISORY HEADLINE GOING.
AFTER MORNING HIGHS IN IN STRONG LOW LEVEL CAA EXPECT EARLY HIGHS
WITH TEMPERATURES FALLING TO LATE AFTN READINGS RANGING FROM THE LOWER
40S NW TO THE LOWER 50S SE. HAVE ADJUSTED AFTERNOON TEMPS A LTL COLDER
IN THIS CAA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
BY EVENING THE PRESSURE GRADIENT WILL BEGIN TO WEAKEN AND THE
WINDS WILL GRADUALLY SLOW DOWN. LEFT OVER WRAP AROUND SHOWERS WILL
CHANGE OVER TO SNOW AS THICKNESSES FALL. THERE SHOULDNT BE ANY
APPRECIABLE ACCUMULATIONS.
BY TUESDAY MORNING SURFACE HIGH PRESSURE WILL BEGIN TO BUILD IN
AND SHOULD PROVIDE DRY WEATHER...ALTHOUGH A FEW SNOW SHOWERS MAY
LINGER OVER FAR NORTHERN LOCATIONS.
ON TUESDAY NIGHT...THE REGION WILL BE IN BETWEEN SYSTEMS...AS
ENERGY IN THE SRN STREAM AFFECTS THE EAST COAST AND ANOTHER S/W IS
DIGGING DOWN THROUGH THE PLAINS. MODELS ARE SHOWING A WIDE RANGE
IN THE STRENGTH AND PATH OF THIS SYSTEM. RIGHT NOW THE CONSENSUS
IS THAT THE REGION WILL REMAIN DRY ON WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FOCUS SHIFTS TO WEAKENING CLIPPER LOW DROPPING SE FROM THE UPPER
MS VLY WED AFTN THRU THE OHIO VALLEY WED NIGHT. NUMERICAL MODELS
HAVE BEEN FLIPPING BACK AND FORTH REGARDING HOW FAR SOUTH THIS
SYSTEM DIGS AND TIMING. LATEST DETERMINISTIC RUNS TAKING WEAK SFC
WAVE FROM CENTRAL IL LATE WED AFTN THRU THE TRI-STATE REGION WED
NIGHT. WILL BRING SNOW IN WED EVENING AND CONTINUE INTO THURSDAY.
SOME PCPN MIX WILL BE POSSIBLE ACRS THE SOUTHEAST. HIGHS ON
THURSDAY TO RANGE FROM THE LOWER/MID 30S NW TO LOWER 40 SE.
IN NORTHWEST FLOW AND CAA SOME LINGERING SNOW SHOWERS PSBL THURSDAY
NIGHT. SFC HIGH PRESSURE TO QUICKLY BUILD ACRS THE REGION EARLY ON
FRIDAY WITH A RETURN FLOW DEVELOPING BY AFTN. WAA PCPN TO DEVELOP
DURG THE AFTN WITH THE BULK OF PCPN STAYING TO OUR NORTH. WILL KEEP
AREA DRY THRU FRIDAY NIGHT. CONTD COLD TEMPERATURES WITH HIGHS ON
FRIDAY TO RANGING FROM THE LOWER 30S NW TO THE UPR 30S SE.
WAA PCPN LOOKS TO DEVELOP SAT AFTN BUT WITH MORE UNCERTAINTY
CREEPING INTO THE FCST REGARDING PLACEMENT/TIMING WILL LIMIT POPS TO
SLIGHT CHANCE OF SHOWERS. THE RAIN COULD MIX OR CHANGE TO SNOW SAT
NIGHT. GFS SOLN APPEARS TOO QUICK WITH COLD FRONTAL PASSAGE. WILL
TREND SOLN CLOSER TO SLOWER ECMWF WITH FRONT HOLDING OFF UNTIL EARLY
MONDAY. IN WAA SECTOR CHANCE OF SHOWERS WILL CONTINUE SUNDAY.
TEMPERATURES WILL MODERATE WITH HIGHS ON SUNDAY FROM UPPER 30S
NORTHWEST TO THE UPPER 40S SOUTH.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
MOST OF THE SHOWER ACTIVITY HAS MOVED OUT OF THE TAF SITES.
HANDLED ANY REMAINING LIGHT SHOWER ACTIVITY WITH A VCSH THIS
AFTERNOON. WINDS WILL CONTINUE TO BE GUSTY THROUGH THE EVENING
HOURS WITH THE GREATEST GUSTS THIS AFTERNOON. WIND GUSTS IN EXCESS
OF 30 TO 40 KNOTS WILL BE POSSIBLE DURING THIS TIME. SOME LESSER
WIND GUSTS WILL CONTINUE INTO TONIGHT BEFORE TAPERING OFF. MVFR
AND VFR CIGS ARE AROUND THE AREA THIS AFTERNOON. EXPECT VFR OR
MVFR CIGS THROUGH THE TAF PERIOD.
OUTLOOK...MVFR CIGS POSSIBLE INTO TUESDAY. MVFR CIGS/VSBYS POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR OHZ026-034-035-
042>046-051>056-060>065-070>074-077>082-088.
KY...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR KYZ089>100.
IN...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ050-058-059-
066-073>075-080.
&&
$$
SYNOPSIS...CONIGLIO/SITES
NEAR TERM...AR/SITES
SHORT TERM...SITES
LONG TERM...AR
AVIATION...NOVAK
AREA FORECAST DISCUSSION
NWS MEDFORD OR
950 AM PST MON NOV 24 2014
.DISCUSSION...CURRENT VISIBLE IMAGE SHOWS SCATTERED HIGH CLOUDS
OVER THE EASTERN PART OF THE REGION AND LOW CLOUDS IN THE VALLEYS.
MORE CLOUDS FROM AN APPROACHING WARM FRONT ARE OFFSHORE AND ARE
EXPECTED TO MOVE INLAND LATER THIS MORNING. THE NAM AND RAP ARE IN
GOOD AGREEMENT HOLDING OFF ANY WARM FRONTAL PRECIPITATION UNTIL
LATE IN THE AFTERNOON AND MOST CONFINED TO WEST OF THE CASCADES.
THUS HAVE TRIMMED BACK POPS FOR THIS MORNING AND AFTERNOON TO
BETTER REFLECT THE TIMING. QPF AMOUNTS TODAY SHOULD ALSO BE
LIGHT. EVEN THE COAST RANGE AND CASCADES WILL PROBABLY GET LESS
THAN A TENTH OF AN INCH BY THIS EVENING. THE WARM FRONT WILL MOVE
THROUGH THIS EVENING AND BRING A BETTER CHANCE OF LIGHT STEADY
PRECIPITATION MAINLY NORTH OF HIGHWAY 140 AND NORTH OF THE UMPQUA
DIVIDE. -PETRUCELLI
&&
.AVIATION...IFR CIGS/VIS REMAIN IN THE ILLINOIS, ROGUE AND
SISKIYOU COUNTY VALLEYS AND IT COULD REMAIN THAT WAY THROUGH EARLY
AFTERNOON BEFORE BREAKING OUT. EVEN THEN IT MAY ONLY BE FOR A
BRIEF TIME. ELSEWHERE VFR CONDITIONS ARE EXPECTED THROUGH THIS
AFTERNOON. MVFR AND LOCAL IFR CIGS RETURN WITH MOUNTAIN
OBSCUATIONS THIS EVENING AND TONIGHT AS A WARM FRONT MOVES INTO
THE AREA. EAST OF THE CASCADES...VFR CONDITIONS WILL CONTINUE
INTO TONIGHT, BUT THERE IS A CHANCE FOR LOW CLOUDS AND FOG TO
DEVELOP IN SOME OF THE BASINS, INCLUDING KLMT. -PETRUCELLI
&&
.MARINE...UPDATED 5 AM PST SUN NOV 23 2014...A WARM FRONT WILL MOVE
OVER THE WATERS THIS AFTERNOON INTO EARLY THIS EVENING. STEEP
MODERATE WEST SWELL WILL SLOWLY SUBSIDE TODAY...BUT THE FRONT WILL
BRING SMALL CRAFT WINDS TO THE AREA THIS AFTERNOON INTO EARLY THIS
EVENING. SO...SEAS WILL REMAIN STEEP WITH CHOPPY SEAS DEVELOPING
TODAY. WINDS AND SEAS WILL BOTH SUBSIDE TONIGHT. OFFSHORE HIGH
PRESSURE WILL REBUILD TUESDAY AND WEAKEN WEDNESDAY. A COLD FRONT
WILL MOVE ACROSS THE WATERS WEDNESDAY NIGHT INTO THURSDAY...FOLLOWED
BY ANOTHER ONE FRIDAY. /CC
&&
.PREV DISCUSSION... /ISSUED 333 AM PST MON NOV 24 2014/
DISCUSSION...
FOR THANKSGIVING TRAVELERS, WE EXPECT SOME LIGHT PRECIPITATION
TODAY THROUGH TUESDAY, WITH NO SNOWY ROADS EXCEPT POSSIBLY A
DUSTING IN THE DIAMOND AND CRATER LAKE AREAS THIS AFTERNOON.
AFTER A DRY BREAK WEDNESDAY, WE EXPECT WETTER WEATHER TO ARRIVE
BEGINNING THANKSGIVING DAY AND THEN PERSISTING THROUGH NEXT
WEEKEND INTO EARLY NEXT WEEK. SNOW LEVELS ARE LIKELY TO REMAIN
ABOVE MAJOR MOUNTAIN PASS ROADWAYS THROUGH EARLY NEXT SUNDAY, BUT
THEN MAY START COMING DOWN. SNOW IMPACTS LOOK POSSIBLE PER THE
LATEST NUMERICAL MODEL GUIDANCE NEXT SUNDAY NIGHT INTO EARLY NEXT
WEEK.
THE SNOW DEPTH AT CRATER LAKE NATIONAL PARK HEADQUARTERS
YESTERDAY MORNING WAS REPORTED TO BE 22 INCHES, WHICH IS 91.6% OF
THE 1931-2000 HISTORICAL AVERAGE. OVER THE NEXT WEEK WE ARE
EXPECTING A WARMING TREND THAT IS LIKELY TO CONSOLIDATE THE SNOW
ON THE GROUND ACROSS THE MOUNTAINS. A COOLER PERIOD IS EXPECTED
TO BEGIN AGAIN SOMETIME LATE NEXT WEEKEND TO EARLY NEXT WEEK TIME
FRAME WITH SNOW ACCUMULATION LIKELY.
TODAY THROUGH TUESDAY WARM AIR WILL OVERRUN THE COOLER AIR MASS IN
PLACE RESULTING IN PLENTY OF CLOUD COVER AND SOME LIGHT
PRECIPITATION. MODELS VARY QUITE A BIT ON AMOUNTS, EXTENT, AND
DURATION, BUT EXPECT MOST OF THE PRECIPITATION TO BE IN THE OREGON
CASCADES, COAST RANGE, COAST, AND UMPQUA BASIN. THESE AREAS MAY
GET A TENTH TO A QUARTER OF AN INCH OF WATER, BUT MOST AREAS WILL
SEE A FEW HUNDREDTHS TO A TRACE OF RAIN.
TUESDAY THROUGH THURSDAY WARM AIR ALOFT WILL DEVELOP AN INVERSION
OVER THE VALLEYS. HOW WARM IT WILL GET IN THE VALLEYS WILL DEPEND
ON HOW COOL IT GETS THE NIGHT BEFORE, WHICH WILL BE MODULATED BY
CLOUD COVER AND WIND. AS TIME GOES BY, THE NEXT STORM SYSTEM IN
THE PACIFIC WILL BEGIN TO DRAW AIR INTO IT RESULTING IN SOUTH AND
EAST WINDS ACROSS THE AREA THAT ARE LIKELY TO DISRUPT AND
EVENTUALLY MIX OUT VALLEY INVERSIONS. THIS SHOULD YIELD SOME
HIGHS IN THE 55-65F RANGE FOR MOST VALLEYS, WHICH IS 5-15F ABOVE
NORMAL.
THANKSGIVING DAY THROUGH THE WEEKEND WE EXPECT RAIN TO DEVELOP AS
A FRONTAL SYSTEM ARRIVES, SLOWS, STALLS, AND THEN PROGRESSES
THROUGH THE AREA. THIS WILL RESULT IN HIGH SNOW LEVELS WITH
INCREASINGLY WET WEATHER ACROSS THE REGION. THIS IS LIKELY TO
TRANSITION TO A COOLER AND WETTER PATTERN AROUND THE LATE SUNDAY-
MONDAY TIME FRAME, WHEN SNOW LEVELS MAY REACH DOWN TO SOME OF THE
PRIMARY MOUNTAIN PASSES AND POSSIBLY THE EAST SIDE, AT TIMES. BTL
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 PM PST THIS EVENING FOR
PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST THIS
EVENING FOR PZZ350-356-370-376.
$$
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1131 AM CST MON NOV 24 2014
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...FAVORABLE FLYING CONDITIONS ARE FORECAST THE NEXT 24
HOURS WITH MODERATE NORTH WINDS AND DRYING LOW LEVELS. A THIRD
NIGHT OF FOG IS NOT CURRENTLY FORECAST AS SURFACE CONDITIONS
SHOULD BE TOO DRY. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 548 AM CST MON NOV 24 2014/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...COLD FRONT IS CURRENTLY SLICING THROUGH SOUTHERN
CAMERON COUNTY WITH DENSE FOG REMAINING OVER THE BRO TERMINAL
CURRENTLY WITH CONDITIONS SLOWLY IMPROVING AT THE HRL TERMINAL.
FRONT SHOULD PASS THROUGH THE BRO TERMINAL AROUND 12Z WITH
VIS/CIGS SLOWLY IMPROVING THROUGH 13Z. VFR SHOULD RETURN TO
BRO/HRL TERMINALS BY 1330Z. GUSTY NORTHERLY WINDS EXPECTED BEHIND
THE FRONT AND THROUGH MOST OF THE DAY WITH DECREASING WINDS
TOWARDS SUNSET. SHOULD EXPERIENCE PLENTY OF HIGH LEVEL CLOUDS BUT
NOT MUCH IN THE WAY OF LOW/MID CLOUDS AS THE ATMOSPHERE SHOULD
REMAIN DRY IN THESE LEVELS.
PREV DISCUSSION... /ISSUED 349 AM CST MON NOV 24 2014/
SHORT TERM /NOW THROUGH TUESDAY/...EXPANDED THE DENSE FOG
ADVISORY TO COVER ALL THE COASTAL AREAS AND GULF WATERS 0-20NM
EAST OF THE COASTLINE. DENSE MARINE FOG ADVECTED IN THROUGH THE
OVERNIGHT HOURS AND HAS CONTINUED ITS N-NW PROGRESSION EVEN
REACHING EASTERN HIDALGO COUNTY. DID ALSO EXTEND THE TIMING
THROUGH 12Z BASED ON THE HRRR NOT BRINGING FROPA THROUGH THE LOWER
VALLEY TILL 12Z AND STRONGER WINDS NOT UNTIL 14Z. SPEAKING OF THE
FRONT...11-3.9 MICRON SHOWS THE FRONT CLEARLY THROUGH MIDDLE TEXAS
COASTAL WATERS AS A FINE LINE OF LOWER STRATUS WITH KRKP AND KCRP
WIND DIRECTIONS SWITCHING TO THE NORTHWEST. EXTRAPOLATING USING
CURRENT SPEED PLACES THE FRONT IN THE LOWER VALLEY BY 12Z MATCHING
UP WITH THE HRRR.
NORTH WINDS WILL PICK UP AFTER THE FRONTAL PASSAGE WITH BREEZY
CONDITIONS THROUGH THE MORNING HOURS WITH WINDS DIMINISHING INTO THE
AFTERNOON HOURS. ALONG THE COAST THE WINDS WILL STAY UP A LITTLE
LONGER THAN MORE INLAND AREAS. WILL BE A NICE AND COOL DAY TODAY
WITH A SOME PASSING HIGH CLOUDS FROM TIME TO TIME. HIGHS WILL BE IN
THE UPPER 60S IN THE RANCHLANDS TO LOWER 70S IN THE VALLEY. SFC HIGH
PRESSURE BUILDS INTO CENTRAL TEXAS OVERNIGHT THEN SINK SOUTHWARDS ON
TUESDAY. WINDS WILL BE FAIRLY LIGHT TONIGHT INTO TUESDAY AND WILL
KEEP SOME CLOUDS CLOUDS AROUND WITH SOUTHWESTERLY FLOW IN THE
MID/UPPER LEVELS UNTIL THE 500MB TROUGH UPSTREAM SWINGS THROUGH
TUESDAY AFTERNOON. MET/MAV TEMPERATURES TONIGHT CAME IN COOLER SO
TRENDED OUR TEMPERATURES DOWNWARD A DEGREE OR TWO ESPECIALLY IN
OUTLYING AREAS. TUESDAY HIGHS ARE A REPEAT OF TODAY.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...EXTENDED PERIOD
CONTINUES TO LOOK PRETTY QUIET AND LITTLE CHANGE WAS MADE TO THE
PRIOR FORECAST. ALL IN ALL A MILD AND FAIRLY DRY WEEK IS IN THE
WORKS. SHORTWAVE TROUGH WILL BE EXITING THE REGION TUESDAY NIGHT
WITH FLOW ALOFT VEERING TO THE NORTHWEST. THE NORTHWEST FLOW WILL
BRING DRY AIR OVER THE REGION...RESULTING IN MOSTLY CLEAR SKIES
TUESDAY NIGHT INTO THURSDAY. TUESDAY NIGHT WILL BE THE COLDEST OF THE
WEEK AS CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPERATURES TO FALL
INTO THE LOWER AND MID 40S. BELOW NORMAL TEMPERATURES WILL CONTINUE
WEDNESDAY THROUGH THURSDAY...WITH HIGHS IN THE LOWER 70S AND LOWS IN
THE MID TO UPPER 40S NORTH AND UPPER 40S TO LOWER 50S SOUTH.
TEMPERATURES AND CLOUD COVER BEGIN TO INCREASE ON FRIDAY AS MODERATE
SOUTHEASTERLY FLOW RETURNS. A 500 MB TROUGH/CUTOFF LOW DEVELOPS OVER
NORTHERN MEXICO ON THURSDAY AND SLOWLY NUDGES EAST THROUGH THE
WEEKEND. THE WEAK TROUGH COMBINED WITH THE INCREASED MOISTURE COULD
RESULT IN A FEW STREAMER SHOWERS OVER THE COASTAL WATERS ON SUNDAY.
MARINE...
NOW THROUGH TUESDAY...A FRONT WILL SWEEP ACROSS THE AREA EARLY
THIS MORNING WITH WINDS SWITCHING TO THE NORTH IN ITS WAKE. STRONG
NORTH WINDS WILL ROUGHEN SEAS AND A SMALL CRAFT ADVISORY HAS BEEN
ISSUED FOR THE GULF OF MEXICO WATERS OF THE LOWER TEXAS COAST
THROUGH MONDAY AFTERNOON. ROUGH SEAS WILL BECOME MORE MODERATE
MONDAY NIGHT INTO AS WIND SPEEDS DECREASE. HOWEVER...A SECONDARY
SURGE OF STRONGER WINDS LOOK TO INVADE AT LEAST THE 20-60NM WATERS
TUESDAY AROUND THE DEPARTING SYSTEM WHICH SMALL CRAFT ADVISORIES
MAY BE NEEDED FOR THE FAR OFFSHORE WATERS FOR SEAS RISING BACK UP
TO AROUND 7 FEET.
TUESDAY NIGHT THROUGH FRIDAY...NORTH WINDS TUESDAY EVENING WILL
BEGIN TO DIMINISH AND SEAS WILL BEGIN TO SUBSIDE AS THE PRESSURE
GRADIENT WEAKENS. SMALL CRAFT ADVISORIES MAY NEEDED TUESDAY NIGHT
FOR THE FAR OFFSHORE WATERS FOR SEAS OF 7 FEET. SEAS WILL CONTINUE
TO SUBSIDE THROUGH THE DAY WEDNESDAY. LIGHT TO MODERATE SOUTHEAST
WINDS AND LOW SEAS WILL PREVAIL THURSDAY AND FRIDAY.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL NOON CST TODAY FOR GMZ130-
132-135.
SMALL CRAFT ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR GMZ150-
155-170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/61
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
342 PM CST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CST MON NOV 24 2014
A PROGRESSIVE AND ENERGETIC FLOW PERSISTS OVER THE CONUS THROUGH
THIS WEEK WITH AN EVOLUTION TO MORE OF A ZONAL OR BROAD FLAT RIDGE
IN THE LARGE SCALE. PREDICTABILITY OVER THE PAST WEEKEND HAS BEEN
LOW...AS SEEN BY THE SHORT RANGE VARIABILITY IN HOW THIS CURRENT
SNOW EVENT TRANSPIRED. NOT PRETTY. THIS WILL CONTINUE THROUGH THE
WEEK...AND CONFIDENCE IS LOW IN TIMING AND PLACEMENT OF WEATHER
SYSTEMS.
LATEST SNOW AMOUNTS IN CENTRAL WISCONSIN ARE IN THE 3 TO 5 INCH
RANGE WITH WINDS CAUSING SOME MEASUREMENT DIFFICULTY. RADAR
INDICATING THAT MOST OF THE CENTRAL WI AREA SHOULD CONTINUE TO
DIMINISH IN INTENSITY AS SNOW SHIELD MOVES NORTHEAST. THE LATEST
RAP TRENDS INDICATE A STRENGTHENING 600-700MB WEAK-MODERATE
FRONTOGENESIS BAND WILL DEVELOP N-S OVER CENTRAL WI LATER THIS
AFTERNOON WHICH COULD BUMP THE RATES A BIT ON WEST END OF THE
SCHIELD. BUT...THAT RAP FRONTOGENESIS GUIDANCE IN THE MID-LEVELS
HAS NOT PROVIDED MUCH FOR SENSIBLE SNOW INCREASE OR BANDING FOR
THIS ENVIRONMENT. OVERALL...FROM TRENDS AND WHAT HAS FALLEN...SNOW
WILL SLOWLY SHIFT EAST THIS EVENING...DIMINISHING. HAVE LOWER
STORM TOTAL AMOUNTS IN CENTRAL WISCONSIN...MORE AROUND 4.5 TO 5
INCHES...AND AFTER COLLABORATION WITH MKX...HAVE DOWNGRADED THE
WARNING TO ADVISORY.
WINDS WILL CONTINUE THROUGH THE EVENING TO CAUSE ROADS TO BE
COVERED AND SNOW PLOW CAMS IN NORTHEAST IA SUGGEST THE ROADS ARENT
TOO CLEAN YET. SO...HAVE DECIDED TO LET THE ENTIRE ADVISORY
CONTINUE THROUGH MIDNIGHT.
WATER VAPOR IMAGERY SHOWING A SHORTWAVE TROUGH DROPPING THROUGH MN
AND RADAR INDICATES SOME SNOW SHOWERS THERE. THIS SHOULD NOT
AMOUNT TO MUCH BUT A BRIEF SNOW SHOWER PERIOD AND MAYBE A BIT OF
VSBY REDUCTION /1-2SM/...BUT NOT A HAZARD GENERALLY. HOWEVER AN
AREA EXISTS AHEAD OF THE SHORTWAVE TROUGH IN MN AND THE HIGHER
LEVEL CLOUD WITH THE SNOW SCHIELD THAT IS PROMOTING SOME FZDZ.
THIS IS FROM SERN MN INTO SWRN WI. SHERIFFS HAVE HAD FZDZ IN GRANT
COUNTY...AND EARLIER IN NERN IA. MOST OF THIS FZDZ SHOULD OCCUR
IN THE ADVISORY AREA AND FOR THE NEXT FEW HOURS AS THE DEEP SNOW
SHOWERS MOVING IN WILL SHIFT THE PRECIPITATION TYPE VIA SEEDER-
FEEDER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CST MON NOV 24 2014
A FAIRLY TRANQUIL PERIOD FOR THE WEEK REALLY WITH A COLDER THAN
NORMAL PERIOD UNDER THE DEEP LONG WAVE TROUGH....BUT AS THIS
BECOMES MORE ZONAL...THE AREA WILL SEE CYCLES OF WARM ADVECTION
AND PRECIPITATION CHANCES...CYCLONE PASSAGE...AND COLD AIR PUSHES.
THE FIRST SHORTWAVE TROUGH COMES ON WEDNESDAY...A HEAVIER TRAVEL
DAY. THIS SHORTWAVE IS COMING INTO BRITISH COLUMBIA COAST
CURRENTLY ON THE POLEWARD SIDE OF A 155 KT 250 MB JET PER 12Z
RAOBS. A PRETTY VIGOROUS SYSTEM THAT DIGS SOUTHEAST IN THE
LONGWAVE TROUGH. THIS WILL BE A 1-2 INCH SNOW MAKER BUT THE TRACK
IS THE QUESTION. HAVE GENERALLY KEPT THE SAME FORECAST AS PREVIOUS
WITH MOSTLY A SRN MN AND NERN IA SYSTEM. CONFIDENCE ON THE TRACK
IS NOT HIGH YET WITH COMPLEX SYSTEM OVER GREAT LAKES AND TOTAL
ENERGY OVER THE CONUS RIGHT NOW. NEW GFS PARALLEL RUN INTENSIFIES
THE NWRLY FLOW ENERGY MORE AND BRINGS MORE SNOW TO THE NORTH...BUT
IS AN OUTLIER. BEHIND THIS SYSTEM...COLD AIR COMES IN FOR
THANKSGIVING...BUT A QUITE WEATHER DAY.
ANOTHER SYSTEM MOVES IN FRIDAY AND IF MY CONFIDENCE IS LOW ON THE
TRACK FOR WEDNESDAY...FRIDAYS WARM ADVECTION SWATH OF SNOW OR
WINTER MIX IS LOWER. GOOD MEDIUM RANGE GUIDANCE CONSENSUS ON THE
TRACK RIGHT NOW...BUT THAT DOESNT MEAN IT WILL BE CORRECT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1212 PM CST MON NOV 24 2014
BULK OF HEAVIEST SNOW HAS SHIFTED EAST OF THE AIRFIELDS. IN FACT
KRST DEVOID OF SNOW FOR THE TIME BEING. RADAR LOOPS INDICATE THE
BACK EDGE OF THE MAIN SNOW AREA SHOULD PUSH EAST OF KLSE THIS
AFTERNOON...BUT MODEL TRENDS SUGGEST THAT BACK EDGE WILL SLOW OR
EVEN STALL FOR A TIME. MEANWHILE...BRISK NORTHERLY WINDS ON THE
BACK SIDE OF THE SYSTEM WAS SENDING SOME SNOW SOUTHWARD ACROSS MN
AND THAT LOOKS TO MOVE ACROSS THIS AFTERNOON AND EVENING. FOR THE
MOST PART TAFS WERE ISSUED TAKING THESE FACTORS INTO ACCOUNT. BUT
ONE OTHER CONCERN IS THE POTENTIAL FOR FREEZING DRIZZLE. THIS IS
OCCURRING ACROSS PARTS OF EASTERN IA WHERE THE DEEPER CLOUD AND
SUPPLY OF ICE HAS MOVED OUT. FEELING FOR THE TAF LOCATIONS WAS
THAT THIS SHOULD NOT IMPACT THEM AS THE ICE CLOUD SOURCE WOULD
LINGER LONG ENOUGH FOR THE CLOUD INFLUENCE FROM THE NORTHERLY
SOURCE TO ARRIVE. BY TUESDAY MORNING...SKIES SHOULD BE CLEARING
AS THE SYSTEM FINALLY PULLS AWAY.
LAST CONCERN IS BRISK NORTHWEST WIND. EXPECT SPEEDS TO CONTINUE IN
THE 15-20 KT RANGE WITH GUSTS UP AROUND 30KTS THROUGH THE EVENING
BEFORE DIMINISHING AS THE INFLUENCE FROM THE STORM COMPLEX WANES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ017-
029-032>034-041>044-053>055-061.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ088-
096.
IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ011-
030.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...MW