Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/24/13
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1035 AM MDT TUE OCT 22 2013
.UPDATE...
&&
.SHORT TERM...ONGOING FORECASTS LOOK GOOD. BATCH OF MID LEVEL
CLOUD OVER FAR NORTHEAST COLORADO MOVING SOUTHEAST. NEXT BATCH
OVER EASTERN WYOMING AND WESTERN NEBRASKA ALSO HEADING
SOUTHEAST...SHOULD BE CLIPPING THE NORTHEAST CORNER AROUND 18Z.
OTHERWISE...MAINLY CLEAR SKIES TO PREVAIL THROUGH THE AFTERNOON
AND EVENING. FORECAST SOUNDINGS AND THICKNESS PROGS SUGGEST HIGHS
ACROSS PLAINS TO WARM INTO THE 60S. ONLY MINOR TWEAKS TO
TEMPERATURE GRIDS AT THIS TIME.
.AVIATION...CURRENT TAF TRENDS SEEM ON TRACK. LIGHT SOUTHEAST
WINDS TO SHIFT TO THE NORTHEAST AROUND 19Z...THEN BACK TO
SOUTHEAST AT 23Z. SLIGHT CHANCE OF AN ANTICYCLONE DEVELOPING NEAR
THE DENVER AREA WHICH MAY KEEP WINDS SOUTHEAST THROUGH THE
AFTERNOON...LATEST HRRR AND RAP SHOW THIS FEATURE FAIRLY WEAK.
WILL MAINTAIN THE CURRENT TAF SOLUTION. VFR CONTINUES.
&&
.PREV DISCUSSION... /ISSUED 403 AM MDT TUE OCT 22 2013/
SHORT TERM...CURRENT SATELLITE IMAGERY SHOWS MID LEVEL CLOUD DECK
STILL HOLDING OVER THE NORTHEAST PLAINS. HOWEVER...THERE ARE SIGNS
OF EROSION FROM THE NORTHWEST AS UPSTREAM CLOUD BAND EXTENDING
INTO WYOMING WAS BEGINNING TO BREAK UP. AS A RESULT...EXPECT THE
NEARLY OVERCAST SKIES OVER THE NORTHEASTERN PLAINS TO SEE A
GRADUAL EROSION THROUGH THE MORNING HOURS LEAVING BEHIND MOSTLY
SUNNY SKIES BY AFTERNOON. FROM THE FRONT RANGE URBAN CORRIDOR
WESTWARD ACROSS THE MOUNTAINS...SKIES WILL BE MOSTLY SUNNY
THROUGH THE ENTIRE DAY. WARM ADVECTION WAS UNDERWAY AND WE EXPECT
ABOUT 4C WARMING FROM YESTERDAY. THIS ALONG WITH A WARMER START TO
THE DAY WILL HELP PUSH HIGHS CLOSE TO 10 DEGREES F WARMER. TODAY
WILL BE OUR FIRST DAY WITH AN ABOVE NORMAL HIGH SINCE OCT 13TH.
FOR TONIGHT...MOSTLY CLEAR SKIES AND LIGHT WINDS SHOULD ALLOW FOR
BETTER RADIATIONAL COOLING AND LOW TEMPS CLOSER TO NORMAL.
LONG TERM...A VERY STABLE RIDGE/TROUGH UPPER AIR PATTERN WILL
REMAIN IN POSITION OVER THE COUNTRY THROUGH THE END OF THE WEEK...
LEAVING COLORADO HIGH AND DRY THROUGH THE FORECAST PERIOD. LIGHT
TO MODERATE NORTHWESTERLY FLOW ALOFT WILL CONTINUE AS THE WESTERN
U.S. UPPER RIDGE IS HELD IN PLACE BY A DEEP TROUGH OVER THE GREAT
LAKES AND EASTERN CANADA. FOR WEDNESDAY AND THURSDAY...
TEMPERATURES WILL BE AROUND SEASONAL NORMALS...BUT THEN WARMER
TEMPERATURES ARE EXPECTED FOR THE WEEKEND. DRY CONDITIONS WILL
PREVAIL ACROSS THE FORECAST AREA.
A CHANGE IN THE UPPER PATTERN LOOKS TO BE IN THE OFFING FOR THE
FIRST PART OF NEXT WEEK. MODELS ARE OFFERING A PLETHORA OF
SOLUTIONS FOR NEXT MONDAY AFTERNOON. THE GFS OPERATIONAL RUN
SPREADS A STRONG PUSH OF CANADIAN AIR ACROSS THE NORTHERN AND
CENTRAL ROCKIES...WHILE THE ECMWF DEVELOPS A MORE CLOSED SYSTEM
OVER THE GREAT BASIN WHICH WOULD DELAY ANY COLD AIR MOVING INTO
COLORADO UNTIL THE UPPER LOW MOVES OVER THE STATE. IT IS HARD TO
TELL WHICH SOLUTION IS GOING TO BE RIGHT...SO FOR THE TIME BEING
WILL STICK WITH A SLIGHT CHANCE OF RAIN AND SNOW OVER THE FORECAST
AREA ON MONDAY WITH COOLER TEMPERATURES THAN OVER THE WEEKEND.
AVIATION...VFR CONDITIONS WILL PERSIST THROUGH TONIGHT. SLIGHTLY
ENHANCED DRAINAGE WEST/SOUTHWEST WINDS THIS MORNING WILL MOST
LIKELY TRANSITION TO LIGHT/VARIABLE BY 15Z-17Z...NORTHEAST BY
19Z-20Z...AND THEN SOUTHEAST BY 23Z-01Z. SPEEDS AFTER 15Z WILL BE
AROUND 10KTS OR LESS. THERE IS A CHANCE OF AN ANTICYCLONE
DEVELOPING WHICH WOULD PRODUCE A MORE SOUTHEASTERLY COMPONENT
DURING THE AFTERNOON. KBJC MAY SEE A FEW WESTERLY GUSTS TO AROUND
20KTS TIL 15Z.
HYDROLOGY...NO PRECIPITATION WILL OCCUR THROUGH THIS WEEKEND.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....DANKERS
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MIAMI FL
246 PM EDT TUE OCT 22 2013
.SHORT TERM (TONIGHT-THURSDAY NIGHT)...
THE LATEST WRF/HRRR MODEL SOLUTIONS INDICATE MAINLY
SCATTERED SEA BREEZE DRIVEN SHOWERS/TSTMS CONTINUING TO INITIATE
ACROSS PORTIONS OF THE AREA...THEN BECOMING CONCENTRATED OVER THE
NORTHEASTERN SECTIONS OF THE AREA OR AROUND THE LAKE REGION TO THE
PALM BEACH COAST THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS
BEFORE DIMINISHING. THE LATEST SHORT-RANGE MODEL GUIDANCE HAS
INITIALIZED WELL WITH THE CURRENT SYNOPTIC PATTERN AND GENERALLY
INDICATES THE ABOVE AVERAGE TEMPERATURES PERSISTING THROUGH
WEDNESDAY AS A COLD FRONT APPROACHES AND MOVES INTO THE LOCAL AREA.
OVERNIGHT LOWS ARE FORECAST TO DROP INTO THE 70S TONIGHT AND RETURN
TO THE MID TO UPPER 80S THROUGH THE AFTERNOON PERIOD
WEDNESDAY...WHICH IS AROUND 3-5 DEGREES WARMER THAN AVERAGE FOR THIS
PERIOD. MODEL SOUNDINGS AROUND THE LOCAL AREA INDICATE THE DEEP
SOUTHWEST FLOW ALONG WITH INCREASING DEEP LAYER MOISTURE CONTINUING
AHEAD OF THE SHORTWAVE TROUGH CURRENTLY MOVING OVER THE MS VALLEY
REGION. UPPER HEIGHTS WILL BEGIN TO FALL LATER TONIGHT THROUGH THE
END OF THE PERIOD AS THIS UPPER TROUGH APPROACHES AND MOVES OVER THE
EAST COAST. THE FRONTAL BOUNDARY IS FORECAST TO PUSH THROUGH THE
LOCAL AREA THROUGH THE DAY WEDNESDAY WITH THE LOW-LEVEL WINDS
FORECAST TO QUICKLY VEER AND INCREASE OUT OF THE NORTHEAST WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT. NORTHEAST WINDS WILL LIKELY BECOME
GUSTY THROUGH THIS TIME THURSDAY...ESPECIALLY OVER THE ADJACENT
MARINE AREAS AND ALONG THE EAST COAST. ALTHOUGH MUCH DRIER AND
COOLER AIR WILL BEGIN TO SPREAD SOUTH INTO PORTIONS OF THE AREA
THROUGH THE DAY THURSDAY...THE RAIN CHANCES WILL REMAIN UP OVER THE
SOUTHERN HALF OF THE LOCAL AREA WHERE MODEL PWATS REMAIN AROUND THE
2" MARK. IN ADDITION TO THE RAIN CHANCES THURSDAY...SOME TSTMS WILL
REMAIN POSSIBLE THROUGH THE FIRST HALF OF THE DAY OVER THESE
SOUTHERN AREAS.
.LONG TERM (FRIDAY-MONDAY)...
MODELS REMAIN IN AGREEMENT WITH A SECONDARY FRONT SURGING THROUGH
THE AREA FRIDAY BRINGING A MUCH DRIER AIR MASS INTO SOUTH FLORIDA
ALONG WITH BELOW NORMAL TEMPERATURES. FAIRLY WIDESPREAD 50S SHOULD
BE SEEN ACROSS INTERIOR AREAS BOTH SATURDAY AND SUNDAY MORNINGS
WITH HIGHS EACH DAY IN THE LOW 80S ACROSS THE EAST COAST.
LONG-RANGE MODELS INDICATE THAT THE DRY PATTERN WILL CONTINUE
ACROSS THE AREA INTO THE FIRST PART OF NEXT WEEK WITH NORTHEAST
SURFACE FLOW PREVAILING.
&&
.AVIATION...18Z TAFS OCT. 13 2013
CURRENTLY HAVE A FEW SHRA MOVING NNE ALONG THE EAST COAST SEA BREEZE
AND THIS TREND WILL LIKELY TO CONTINUE THROUGH THE AFTERNOON WITH
ADDITIONAL DEVELOPMENT OVER INLAND AREAS. THERE COULD ALSO BE A TSRA
OR TWO BUT OVERALL CONFIDENCE AND COVERAGE TOO LOW TO PLACE IN THE
FORECAST AT THIS TIME. SOME OF THE ACTIVITY COULD PERSIST INTO THE
EVENING, HOWEVER THE HRRR HINTS AT LITTLE ACTIVITY PAST 00Z. SOME
LOCATIONS COULD HAVE VERY BRIEF MVFR OR EVEN IFR BUT TIMING AND
EXACT LOCATION WITH LOW COVERAGE ALWAYS DIFFICULT TO FORECAST SO
LEFT LIMITED RESTRICTIONS FOR NOW AND WILL AMEND IF NECESSARY. MOST
OF THE CONVECTION WILL BE WELL EAST OF KAPF UNTIL LATER IN THE
FORECAST WHEN THE FRONT SHIFTS SOUTH AND MAY HAVE AN INCREASE IN
SHRA OVER THE GULF WATERS AFT 06Z.
KOB
&&
.MARINE...
LIGHT SOUTH-SOUTHEAST WINDS WILL SHIFT TO THE SOUTH-
SOUTHWEST LATER TONIGHT AHEAD OF AN APPROACHING COLD FRONT.
SCATTERED SHOWERS DEVELOPING OUT AHEAD OF THIS BOUNDARY WILL
REMAIN POSSIBLE THROUGH THE MID-WEEK TIME FRAME. DRIER AIR ALONG
WITH INCREASING WINDS AND SEAS ARE FORECAST TO SPREAD SOUTH OVER
THE MARINE AREAS IN THE WAKE OF THE FRONT BEGINNING THURSDAY AND
CONTINUING INTO THE UPCOMING WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 74 86 70 81 / 30 50 40 20
FORT LAUDERDALE 77 87 73 82 / 30 40 40 30
MIAMI 75 88 72 82 / 30 40 40 40
NAPLES 74 87 66 84 / 30 40 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...30/KOB
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
1031 AM EDT TUE OCT 22 2013
...FOGGY MORNING TRANSITIONS TO A SOGGY EVENING AS A COLD FRONT
APPROACHES...
.UPDATE...
MOIST AIRMASS AHEAD OF AN APPROACHING COLD FRONT PRODUCED PATCHES
OF DENSE FOG FOR PORTIONS OF THE EASTERN TAMPA BAY AREA THIS
MORNING...WITH AREAS OF FOG OVER MUCH OF WEST CENTRAL AND
SOUTHWEST FLORIDA THIS MORNING. AS THE DAYTIME HEATING
CONTINUES...EXPECT THE FOG TO IMPROVE AND THE LOW STRATUS CLOUDS
TO LIFT. ALLOWED DENSE FOG ADVISORY TO EXPIRE AT 10 AM...AND ISSUED
UPDATED ZONES TO REMOVE MENTIONS OF FOG.
OTHERWISE...06Z MAV GUIDANCE IS TRENDING TOWARDS THE RAINS AHEAD
OF THE FRONT ARRIVING FASTER AND AFFECTING THE TAMPA BAY AREA
SOUTHWARD SOONER. HAVE UPDATED THE FORECAST TO SHOW THESE ELEVATED
RAIN CHANCES. LINE OF RAIN CAN BE SEEN ON RADAR IN THE GULF ABOUT
TO ENTER THE TBW OUTER WATERS AND 07Z HRRR GUIDANCE SHOWS THE
POTENTIAL FOR A LINE OF SHOWERS FROM TAMPA BAY NORTHWARD LATE
AFTERNOON INTO THE EARLY EVENING. RAISED POPS AFTER 00Z AS
WELL...TO ACCOUNT FOR THE INCREASING CHANCE OF SOME RAIN OVERNIGHT
AS THE MAIN LINE MOVES THROUGH. WILL CONTINUE TO KEEP AN EYE ON
THESE TRENDS FOR THE NEXT FORECAST PACKAGE ISSUANCE LATER THIS
AFTERNOON.
&&
.AVIATION...
IFR/LIFR CIGS AND VSBYS AT KLAL AND MVFR VSBYS AT KTPA WILL ERODE
AWAY BY 15Z THIS MORNING WITH VFR EXPECTED AT ALL TERMINAL SITES
THE REMAINDER OF TODAY WITH AN INCREASE IN MID AND HIGH LEVEL CLOUDS
DURING THE AFTERNOON WITH SOME VCSH FROM KSRQ NORTH TO KTPA...KPIE
AND KLAL AFTER 22Z. CIGS AND VSBY WILL BEGIN TO LOWER TONIGHT WITH
CLOUDS THICKEN AND RAIN CHANCES INCREASE ACROSS THE REGION AHEAD OF
COLD FRONT...WITH MVFR CIGS DEVELOPING AT ALL SITES AFTER 23/09Z.
LIGHT AND VARIABLE WINDS WILL BECOME SOUTHWEST TO WEST AROUND 10 KNOTS
AFTER 15Z.
&&
.MARINE...
LINE OF RAIN MOVING INTO THE WATERS IN THE NEXT FEW HOURS. EXPECT
CONDITIONS TO DETERIORATE THROUGHOUT THE DAY. NO MAJOR CHANGES TO
THE FORECAST...EXPECTING STRONGER WINDS AND WAVES BEHIND THE FRONT
THAT COULD REACH CAUTIONARY...AND POSSIBLY ADVISORY...CRITERIA.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 86 74 84 63 / 50 70 40 10
FMY 89 75 87 68 / 30 60 60 40
GIF 89 72 84 62 / 50 60 40 10
SRQ 86 73 85 64 / 40 70 50 20
BKV 86 71 83 54 / 60 70 30 10
SPG 86 76 84 69 / 50 70 40 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...02/GARCIA
AVIATION...57/MCMICHAEL
AREA FORECAST DISCUSSION
NWS MIAMI FL
958 AM EDT TUE OCT 22 2013
.UPDATE...
THE MORNING SURFACE ANALYSIS SHOWED A FRONTAL BOUNDARY EXTENDING
WSW FROM CENTRAL FLORIDA TO THE SOUTHWEST GULF OF MEXICO AND A
WEAK RIDGE AXIS EXTENDING WWD ACROSS THE BAHAMAS. OBSERVATIONS
AROUND THE LOCAL AREA SHOWED LIGHT SSE WINDS AROUND THIS RIDGE
AXIS WITH DEWPOINTS IN THE MID 70S. ALTHOUGH THERE WERE SOME SMALL
PATCHES OF FOG AROUND AND JUST BEFORE DAYBREAK...THE LATEST
SATELLITE IMAGERY INDICATED THOSE AREAS HAVE BURNED OFF WITH
MOSTLY CLEAR SKIES. THE MORNING SOUNDING AT MIA SHOWED SSE LOW-
LEVEL WINDS VEERING TO THE SW ABOVE 850 MB AND A PWAT OF 1.75".
THE LATEST RUC ANALYSIS LINES UP WELL WITH THE CURRENT SYNOPTIC
PATTERN AND GENERALLY INDICATES THE DEEP LAYER MOISTURE INCREASING
THROUGH THE DAY AS AN UPPER TROUGH AND FRONTAL BOUNDARY APPROACH
THE AREA. THE LATEST WRF/HRRR MODEL SOLUTIONS INDICATE MAINLY
SCATTERED SEA BREEZE DRIVEN SHOWERS/TSTMS INITIATING ACROSS
PORTIONS OF THE AREA...THEN BECOMING CONCENTRATED OVER THE
NORTHEASTERN SECTIONS OF THE AREA OR AROUND THE LAKE REGION TO THE
PALM BEACH COAST THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS.
THE CURRENT FORECAST PACKAGE REMAINS ON TRACK WITH NO MAJOR UPDATES
NECESSARY AT THIS TIME. 85/AG
&&
.PREV DISCUSSION... /ISSUED 751 AM EDT TUE OCT 22 2013/
AVIATION...
TERMINAL KAPF COULD EXPERIENCE BRIEF PERIODS OF MINOR VISIBILITY
RESTRICTIONS AND SCT002 IN THE EARLY MORNING HOURS DUE TO FOG/LOW
STRATUS. BY 12Z- 13Z THE FOG/STRATUS SHOULD DISSIPATE BUT
REMAINING VFR. THUNDERSTORM ACTIVITY THIS AFTERNOON IS EXPECTED TO
BE ISOLATED AND MAINLY IN THE VICINITY OF TERMINAL KPBI BUT VCTS
NOT ASSIGNED WITH COVERAGE EXPECTED TO BE LOW.
BD/KOB
PREV DISCUSSION... /ISSUED 400 AM EDT TUE OCT 22 2013/
DISCUSSION...
SHOWERS AND THUNDERSTORMS FROM LAST EVENING HAVE DISSIPATED AND
GIVEN WAY TO MOSTLY CLEAR SKIES ACROSS THE AREA. DUE TO THE WET
GROUND AND A DIFFUSE BOUNDARY DRAPED ACROSS THE CENTRAL FLORIDA
PENINSULA...AREAS OF FOG WILL BE POSSIBLE THIS MORNING MAINLY
ACROSS INTERIOR AREAS.
MOISTURE RICH SOUTHWEST FLOW WILL CONTINUE THROUGH THE DAY WITH
CHANCES FOR AFTERNOON SHOWERS AND A FEW THUNDERSTORMS AGAIN MAINLY
ACROSS THE INTERIOR. HUMIDITY LEVELS WILL ALSO INCREASE AS A
RESULT WITH PWAT VALUES APPROACHING 2 INCHES.
THE FORECAST FOCUS WILL THEN TURN TO THE APPROACHING COLD FRONT
THAT IS EXPECTED TO ENTER THE AREA WEDNESDAY AFTERNOON. AS THE
FRONT PUSHES THROUGH...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP ALONG THE BOUNDARY. WITH PWATS NEARING 2.25 INCHES BY
WEDNESDAY EVENING...THE MAIN THREAT AT THIS TIME WITH ANY STORMS
WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL WEDNESDAY
AFTERNOON AND EVENING.
AS THE FRONT CLEARS THE AREA LATE WEDNESDAY NIGHT...MODELS STILL
INDICATE DEEP MOISTURE OVERRUNNING THE BOUNDARY WITH CONTINUED
SOUTHWEST FLOW ALOFT THROUGH THURSDAY. THIS WILL KEEP RAINFALL
CHANCES THROUGH THURSDAY WITH BETTER CHANCES TO THE SOUTH. MODELS
THEN STAY IN AGREEMENT WITH A SECONDARY FRONT SURGING THROUGH THE
AREA FRIDAY BRINGING A MUCH DRIER AIR MASS INTO SOUTH FLORIDA
ALONG WITH BELOW NORMAL TEMPERATURES. FAIRLY WIDESPREAD 50S SHOULD
BE SEEN ACROSS INTERIOR AREAS BOTH SATURDAY AND SUNDAY MORNINGS
WITH HIGHS EACH DAY IN THE LOW 80S ACROSS THE EAST COAST.
LONG RANGE MODELS INDICATE THAT THE DRY PATTERN WILL CONTINUE
ACROSS THE AREA INTO THE FIRST PART OF NEXT WEEK WITH NORTHEAST
SURFACE FLOW PREVAILING.
MARINE...
LIGHT SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH TONIGHT AHEAD OF
AN APPROACHING COLD FRONT. SCATTERED SHOWERS DEVELOPING OUT AHEAD
OF THIS BOUNDARY WILL REMAIN POSSIBLE THROUGH THE MID-WEEK TIME
FRAME. DRIER AIR ALONG WITH INCREASING WINDS AND SEAS ARE FORECAST
TO SPREAD SOUTH OVER THE MARINE AREAS IN THE WAKE OF THE FRONT
BEGINNING THURSDAY AND CONTINUING INTO THE UPCOMING WEEKEND.
AVIATION...
MAINLY VFR CONDITIONS ARE EXPECTED FOR ALL SOUTH FLORIDA
TERMINALS EARLY THIS MORNING. THERE COULD BE SOME PATCHY
FOG OR AREAS OF FOG EARLY THIS MORNING...BUT MAINLY EXPECTED IN
THE INTERIOR REGIONS. BUT WILL AMEND AS NECESSARY. LIGHT
SOUTHEASTERLY FLOW PREVAILS ACROSS THE REGION BUT COULD BE LIGHT
AND VARIABLE AT THE TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 72 87 73 / 30 30 50 30
FORT LAUDERDALE 87 76 87 74 / 20 20 50 40
MIAMI 88 75 87 75 / 20 20 50 40
NAPLES 88 73 87 71 / 20 30 50 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...30/KOB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
945 PM EDT WED OCT 23 2013
.SYNOPSIS...
HIGH PRESSURE AND A MUCH DRIER AIR MASS WILL MOVE INTO THE AREA
TONIGHT AND THEN PERSIST THROUGH THURSDAY. AN ARCTIC-LIKE COLD
FRONT WILL MOVE THROUGH ON FRIDAY WITH A LARGE AREA OF COOL HIGH
PRESSURE ENCOMPASSING THE REGION BEHIND IT. HIGH PRESSURE WILL
REMAIN THE DOMINANT FEATURE THROUGH EARLY NEXT WEEK ALTHOUGH
TEMPERATURES WILL BEGIN TO MODIFY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A CONSIDERABLY DRIER AND COOLER AIRMASS CONTINUES TO ADVECT INTO
THE REGION THIS EVENING IN THE WAKE OF A COLD FRONT. HIGH PRESSURE
IS FORECAST TO MOVE INTO WEST-CENTRAL GEORGIA BY SUNRISE...
ALLOWING FOR A GRADUAL RELAXING OF THE PRESSURE GRADIENT. SHOULD
SEE MODEST RADIATIONAL PROCESSES TAKE HOLD AS A RESULT...
ESPECIALLY ACROSS INTERIOR SOUTHEAST GEORGIA WHERE THE BOUNDARY
LAYER COULD COMPLETELY DECOUPLE. LOWS FROM THE UPPER 30S ACROSS
THE HIGHER TERRAIN OF JENKINS-SCREVEN-ALLENDALE COUNTIES TO THE
UPPER 40S/LOWER 50S AT THE BEACHES LOOK ON TARGET FOR NOW.
IT SHOULD BE NOTED THAT THE 23/18Z GFS BASED COOP GUIDANCE SHOWS A
FEW LOCATIONS SUCH AS SYLVANIA...ALLENDALE AND RIDGEVILLE DROPPING
TO 36/35/34 DEGREES RESPECTIVELY. GIVEN THIS IS THE FIRST REAL DOSE
OF COLD AIR FOR THE FALL SEASON...IT IS UNCLEAR HOW GUIDANCE IS
PERFORMING WITH THIS AIRMASS. PLAN TO LIMIT LOWS TO THE UPPER 30S
FOR NOW...ALTHOUGH A FEW MID 30S CAN NOT BE COMPLETELY RULED OUT.
ANY FROST THAT MAY DEVELOP WILL BE LIGHT AND VERY PATCHY GIVEN THE
MARGINAL CONDITIONS. FINALLY...THERE COULD BE SOME MESOSCALE LAKE
INFLUENCES IN THE MONCKS CORNER AREA OVERNIGHT. WITH A LIGHT NORTH
TO NORTHWEST FLOW EXPECTED TO PERSIST...THIS MAY BE JUST ENOUGH TO
ADVECT WARMER AIR FROM OFF LAKE MOULTRIE INTO THE CITY. THIS WILL
BE A TOUGH FORECAST POINT TO PIN DOWN...SO ADJUSTMENTS MAY BE
NEEDED WITH THE UPDATE EARLY THURSDAY MORNING.
THE FOLLOWING CHANGES WERE MADE FOR THE LATE EVENING UPDATE...
1. MADE MINOR ADJUSTMENTS TO HOURLY TEMPERATURES BASED ON 9 PM
OBSERVATIONS.
2. INCREASED WINDS TO 15-20 KT ON LAKE MOULTRIE AS WINDS ARE
EXPECTED TO SURGE SLIGHTLY OVER THE NEXT FEW HOURS AS A SECONDARY
DOSE OF COLD AIR ADVECTION OVERSPREADS THE REGION.
ALL OTHER GRIDDED ELEMENTS ARE ON TRACK.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
THURSDAY...THE AREA WILL REMAIN UNDER ZONAL FLOW WITH WNW WINDS OF
20-25 KT AROUND 850 MB. COLD ADVECTION WILL CONTINUE AS A 1025 MB
HIGH PRESSURE SYSTEM SHIFTS SOUTHEAST TOWARD THE SOUTHEAST STATES.
ANOTHER DAY OF CLEAR SKIES AND DRY AIR WILL OCCUR...WITH HIGH
TEMPERATURES AROUND 70 DEGREES. COOL TEMPS IN THE LOWER TO MIDDLE
40S EXPECTED THURSDAY NIGHT AS WEAK COLD ADVECTION CONTINUES.
AN ARCTIC-LIKE FRONT WILL DROP SOUTH THROUGH THE AREA FRIDAY MORNING
WITH AN EXPANSIVE COLD...DRY 1028 MB HIGH OVERSPREADING THE EASTERN
UNITED STATES. THE DOWNSLOPE INFLUENCE WEAKENS ON FRIDAY SO THERE
WILL BE LESS IN THE WAY OF COMPRESSIONAL HEATING TO OFFSET THE COLD
ADVECTION. THUS HIGH TEMPS WILL ONLY REACH THE MIDDLE 60S IN
SOUTHERN SC AND UPPER 60S IN SOUTHEAST GA.
FRIDAY NIGHT LOOKS TO BE THE COLDEST OF THE SEASON THUS FAR. COLD
HIGH PRESSURE SETTLING OVER THE AREA WITH CLEAR SKIES AND FAIRLY
LIGHT WINDS WILL ALLOW TEMPERATURES TO PLUMMET AFTER SUNSET. WE
LOWERED TEMPERATURES A FEW DEGREES...WITH READINGS AS LOW AS 34
DEGREES FAR INLAND TO AROUND 40 IN THE BELT CLOSER TO THE COAST.
GEOSTROPHIC WINDS WILL BE LESS THAN 15 KT OVERNIGHT...A BIT LOWER
FARTHER INLAND AS THE GRADIENT BECOMES LESS TIGHT. WITH OVERNIGHT
DEWPOINTS RANGING FROM 28-31...THERE STANDS A DECENT CHANCE THAT
SOME OF OUR RURAL INLAND ZONES MAY EXPERIENCE SCATTERED FROST SO WE
WILL INCLUDE THIS POSSIBILITY IN THE HAZARDOUS WEATHER OUTLOOK.
DESPITE SUNNY SKIES...SATURDAY WILL REMAIN COOL DUE TO THE COLD
AIRMASS IN PLACE SO HIGH TEMPS WILL ONLY REACH THE MIDDLE 60S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
FORECAST CONFIDENCE IN THE LONG TERM PERIOD CONTINUES TO BE GOOD.
OVERALL THE PERIOD WILL BE QUIET WITH SURFACE HIGH PRESSURE BEING
THE PRIMARY FEATURE. WEAK HIGH PRESSURE WILL COVER THE AREA FOR THE
LATTER PART OF THE WEEKEND AND INTO MONDAY. THIS WEAK PRESSURE
PATTERN WILL THEN EVENTUALLY BE REPLACED BY LOW LEVEL NORTHEAST FLOW
AS A STRONGER 1035 MB SURFACE HIGH BUILDS IN NORTHEAST OF THE REGION
BY TUESDAY. WE MAY SEE A SUBTLE COASTAL TROUGH DEVELOP OFFSHORE AND
GENERATE A FEW SHOWERS OVER THE WATERS...BUT LAND AREAS WILL REMAIN
DRY. TEMPS WILL GRADUALLY MODERATE BY EARLY NEXT WEEK...WITH HIGHS
IN THE MID 70S AND LOWS IN THE LOW/MID 50S.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
NO CONCERNS.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS FRIDAY.
&&
.MARINE...
TONIGHT...EXPANDED FLAGS INTO ALL NEARSHORE LEGS. HIGHER
RESOLUTION RAP AND H3R MODELS SHOW A STRONGER...SECONDARY WIND
SURGE WORKING DOWN THE COAST THIS EVENING AS ANOTHER PUSH OF COLD
AIR ADVECTION MOVES THROUGH. SHOULD SEE AT LEAST FREQUENT GUSTS TO
25 KT THROUGH ABOUT 2 AM. SEAS WILL RANGE FROM 2-4 FT NEARSHORE
WATERS TO 4-5 FT OFFSHORE WATERS.
THURSDAY THROUGH SUNDAY...CONDITIONS WILL START OUT RELATIVELY
QUIET ON THURSDAY AS WEAKER HIGH PRESSURE SITS ACROSS THE REGION.
THIS WILL CHANGE ON FRIDAY AS A STRONG COLD FRONT PUSHES THROUGH
THE REGION. MUCH COOLER AIR WILL RUSH ACROSS THE WARMER
WATERS...AND GOOD MIXING PROFILES WILL DEVELOP. NORTHWEST TO NORTH
WINDS WILL STEADILY STRENGTHEN THROUGH THE DAY FRIDAY AND
ESPECIALLY DURING THE EVENING HOURS. WE CURRENTLY SHOW WINDS/SEAS
JUST BELOW SMALL CRAFT ADVISORY THRESHOLDS THOUGH A BRIEF PERIOD
OF ADVISORY CONDITIONS IS POSSIBLE ON THE OFFSHORE GA WATERS LATE
FRIDAY INTO FRIDAY NIGHT. CONDITIONS WILL IMPROVE SATURDAY INTO
SUNDAY AS HIGH PRESSURE REMAINS IN CONTROL AND THE PRESSURE
GRADIENT RELAXES.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR AMZ350-352-
354-374.
&&
$$
ST/ECT
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
138 AM EDT TUE OCT 22 2013
.PREV DISCUSSION... /ISSUED 1039 PM EDT MON OCT 21 2013/
UPDATE...
ADJUSTED SLIGHT POPS ONCE AGAIN FARTHER NORTH THROUGH TONIGHT ACROSS
MUCH OF CENTRAL GEORGIA BASED ON COMBINATION OF PROGGED WEAK VORT
MAX LOCATION AND GENERAL CONSENSUS OF MODEL PRECIP...THOUGH A FEW
OUTLIERS INDICATING POTENTIAL ACROSS NORTH GEORGIA AS WELL. NOT
BUYING INTO THIS RIGHT NOW...THOUGH RECENT HISTORY IN A SIMILAR
SYSTEM PROVED OTHERWISE. WILL CONTINUE TO UPDATE AS
NECESSARY...THOUGH ANY RAIN TOTALS ARE EXPECTED TO BE LIGHT.
LATEST NAM CONDENSATION PRESSURE DEFICITS ARE A BIT LOWER AND MORE
EXPANSIVE THAN EARLIER SO HAVE EXPANDED SOUTHEASTERN FOG
POTENTIAL. REST OF FORECAST LOOKS TO BE ON TRACK AND PREVIOUS
DISCUSSION FOLLOWS...
BAKER
PREV DISCUSSION... /ISSUED 813 PM EDT MON OCT 21 2013/
PREV DISCUSSION... /ISSUED 232 PM EDT MON OCT 21 2013/
QUICK SHOT OF RAIN TUESDAY BEFORE COLDER AIR ARRIVES...
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
LATEST SURFACE ANALYSIS OF THE SOUTHEAST STATES SHOWS HIGH
PRESSURE RIDGE REMAINS IN CONTROL BUT INFLUENCE IS WEAKENING. THIS
IS DUE TO THE APPROACH OF AN UPPER LEVEL TROUGH WHICH RUC ANALYSIS
HAS SITUATED FROM EASTERN ILLINOIS THROUGH MISSOURI AND KANSAS AS
WELL AS ADDITIONAL RIPPLES OF UPPER LEVEL ENERGY CLOSER TO HOME
EMBEDDED IN BROADER TROUGH REGIME. AS FAR AS THE SENSIBLE WEATHER
THIS HAS PRODUCED AT THE SURFACE...PRETTY MUCH A MIXED BAG WITH
LOW CLOUDS IN VICINITY OF RIDGE AXIS AROUND ATHENS JUST STARTING
TO BREAK UP AND A MOSTLY SUNNY DAY ELSEWHERE WHICH IS QUICKLY
GIVING WAY TO INCREASED CIRRUS IN SW FLOW ALOFT. SOME LIGHT
RETURNS FORM THIS ON RADAR FOR SOUTHERN SECTIONS BUT NO EVIDENCE
ANY OF THIS IS REACHING THE GROUND JUST YET.
FOR TONIGHT...GULF COAST WAVE AT THE UPPER LEVELS WILL MOVE INTO
SOUTH GEORGIA THIS EVENING ALLOWING FOR INCREASED LIFT AND
MOISTURE BOTH AT THE MID LEVELS AND EVENTUALLY LOW LEVELS BY
DAYBREAK. IN FACT...MODELS INDICATE LOW CLOUDS REDEVELOPING ACROSS
THE SE ZONES WITH SOME POTENTIAL FOR REDUCED VSBY AS WELL PRIOR TO
DAYBREAK. EXPECT THICKENING CLOUD DECK AND AFOREMENTIONED LIFT TO
RESULT IN -RA WITH LOW END CHANCE ADVERTISED FOR NOW. THIS MAY
PROVE TO BE TOO LOW GIVEN THE AMOUNT OF OMEGA INDICATED BY THE
MODELS BUT HAVE AT LEAST RAMPED UP SOME 10 TO 20 PERCENT ABOVE
GUIDANCE.
SAME HOLDS TRUE FOR TUESDAY AS GUIDANCE POPS LOOK MUCH TOO LOW FOR
THE AMOUNT OF MOISTURE AND LIFT INDICATED BY THE
MODELS...ESPECIALLY THE NAM12. SETUP LOOKS AN AWFUL LOT LIKE THIS
PAST SATURDAY WHEN GUIDANCE HAD NO CLUE AND RAIN WAS MUCH MORE
WIDESPREAD THAN EXPECTED. WITH SECONDARY SHOT OF ENERGY COMING
ACROSS LATE IN THE DAY...FEEL LOW END CHANCE POPS AT LEAST ARE
WARRANTED AND THESE MAY NEED TO BE INCREASED FURTHER IF TRENDS
CONTINUE. ALSO WENT ON THE LOW SIDE OF GUIDANCE FOR TUE MAX TEMPS
BASED ON MORE PRECIP AND CLOUD COVER.
DEESE
LONG TERM /WEDNESDAY THROUGH MONDAY/...
VERY LITTLE CHANGES NEEDED TO THE EXTENDED FORECAST. BY WED MORNING
THE MAIN FRONTAL BOUNDARY WILL HAVE MOVED OFF THE GA/SC COAST WITH
HIGH PRESSURE BUILDING INTO THE REGION FROM THE CENTRAL PLAINS. A
COOLER AIRMASS WILL MOVE IN WITH THIS RIDGE AS WE WILL SE SOME OF
THE COOLEST TEMPS SO FAR THIS SEASON. LOW TEMPS THU MORNING EXPECTED
IN THE 30S AND 40S WITH HIGH TEMPS ONLY GETTING UP INTO THE 60S THU.
THIS COOL AIR REMAINS OVER THE REGION THROUGH THE END OF THE WEEK
AND EVEN GETS REINFORCED FRI/SAT AS ANOTHER STRONGER RIDGE MOVES IN
BEHIND A DRY COLD FRONT FROM THE NORTHERN PLAINS. SOME AREAS ACROSS
EXTREME N GA WILL SE BELOW FREEZING TEMPS SAT MORNING. TEMPS WILL
BEGIN TO REBOUND SUN/MON WILL SEE MAINLY BELOW SEASONAL NORMS WED
THROUGH SAT. NO PRECIP EXPECTED THIS WEEK.
01
&&
.AVIATION...
06Z UPDATE...
MAINLY VFR EARLY THIS MORNING...THOUGH EXPECT MVFR FOG TO DEVELOP
AT AHN/MCN. ISOLATED -RA/-SHRA OUT THERE AS WELL BUT NOT ENOUGH TO
INCLUDE IN ANY TAFS AT THIS POINT. CIGS DROP TO LOW VFR THROUGH
THE MORNING HOURS BUT WITH FAIRLY RAPID IMPROVEMENT LATE THIS
AFTERNOON AS THE FRONT PUSHES THROUGH. WINDS SW AND LIGHT TO BEGIN
WITH...VEERING TO W AND REMAINING AROUND 5KT /SLIGHTLY HIGHER AT
ATL/.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON POSSIBILITY OF -SHRA/-RA.
HIGH ON ALL OTHER ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 71 49 67 40 / 20 5 0 0
ATLANTA 71 49 63 40 / 20 5 0 0
BLAIRSVILLE 67 43 57 33 / 20 5 0 0
CARTERSVILLE 71 45 62 37 / 20 0 0 0
COLUMBUS 75 53 71 44 / 30 5 0 0
GAINESVILLE 70 48 62 38 / 20 5 0 0
MACON 74 48 72 42 / 30 5 0 0
ROME 71 44 62 37 / 20 0 0 0
PEACHTREE CITY 72 46 66 38 / 20 5 0 0
VIDALIA 75 55 75 44 / 40 20 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
238 PM CDT TUE OCT 22 2013
.DISCUSSION...
1035 AM CDT
RATHER IMPRESSIVE SYSTEM CONTINUES TO PUSH PRECIP TOWARD THE
FORECAST AREA LATE THIS MORNING. SURFACE ANALYSIS SHOWS LOW
PRESSURE CENTERED NEAR OR JUST NORTH OF KIRKSVILLE MISSOURI WITH
PRESSURE FALLS SUPPORTING A EAST-SOUTHEAST MOVEMENT OVER THE NEXT
FEW HOURS. WATER VAPOR IMAGERY SHOWS THE UPPER TROUGH/VORT MOVING
EASTWARD INTO NORTH CENTRAL ILLINOIS WHILE RADAR IMAGERY SHOWS A
BAND OF PRECIP WORKING EASTWARD ACROSS THE QUAD CITIES AND
EXTENDING SOUTHWARD DOWN THE MISSISSIPPI RIVER VALLEY. THE BULK OF
THE PRECIP SHIELD LINES UP WITH WITH NEAR TERM DEPICTIONS OF
850-700 MB FRONTOGENESIS ACROSS FAR EASTERN IOWA INTO WESTERN
ILLINOIS. RECENT OBS/WEBCAMS/REPORTS SHOW THAT MODERATE TO EVEN
HEAVY SNOW IS FALLING OVER THE QUAD CITIES WITH SEVERAL INCHES
QUICKLY ACCUMULATING ON GRASSY SURFACES/CARS/ROOFTOPS. THE CUTOFF
TO RAIN OCCURS PRETTY QUICKLY JUST SOUTH AND EAST OF THE QUAD
CITIES. ANOTHER BAND OF LIGHTER REFLECTIVITY EXTENDS FROM VINTON
IOWA EAST TO SAVANNA TO ROCHELLE AND NEAR DEKALB WHICH HAS BEEN A
MIX OF SNOW TO THE WEST WITH ROCHELLE NOW COMING IN WITH LIGHT
RAIN. THIS AREA IS FORCED FROM A HIGHER LEVEL...LINING UP WELL
WITH 700-600 MB FGEN. CLOUD BASES ARE STILL PRETTY HIGH WITH THIS
AREA SUGGESTING DRY AIR IS INHIBITING PRECIP FROM MAKING IT TO THE
GROUND BUT THIS FORCING IS EXPECTED TO REMAIN ORGANIZED AS IT
SHIFTS EASTWARD AND EVENTUALLY SLIGHTLY NORTHEASTWARD OVER
SOUTHERN LAKE MICHIGAN BY LATE AFTERNOON. EXPECT THAT SOME LIGHT
PRECIP...PROBABLY MOSTLY RAIN WILL FALL FROM THIS AREA INTO THE
MID AFTERNOON AFFECTING AREAS ALONG/NORTH OF THE INTERSTATE
88/INTERSTATE 290 CORRIDOR.
AS FOR THE MAIN BAND OF PRECIP...FGEN WILL CONTINUE TO SHIFT
EASTWARD AND FOCUS OVER THE CENTRAL/SOUTHERN CWA THROUGH THE
AFTERNOON. OVERALL AREA OF POPS FROM THE EARLIER FORECAST STILL
LOOKS GOOD FOCUSING THEM ALONG AND SOUTH OF INTERSTATE 80 WHICH
LATEST RADAR TRENDS ALSO SUPPORT. PRECIP TYPE WILL REMAIN THE
CHALLENGE WITH THE NARROW CORRIDOR OF MODERATE/HEAVY SNOW
CURRENTLY OCCURRING LIKELY TRANSLATING EASTWARD TOWARD THE WESTERN
CWA TOWARD EARLY AFTERNOON. TEMPS HAVE WARMED TO AROUND 40 BUT
WITH EVAPORATIVE COOLING AND THE INTENSE PRECIP TEMPS WILL LIKELY
FALL BACK INTO THE LOW/MID 30S AS THE BAND ARRIVES ASSUMING IT
MAINTAINS INTENSITY. THE MOST LIKELY AREA FOR SNOW LOOKS TO BE
RIGHT ALONG AND JUST SOUTH OF INTERSTATE 80 ACROSS SOUTHERN
LASALLE AND GRUNDY COUNTIES AND ALONG THE WILL/KANKAKEE BORDER
AREA GIVEN THAT TEMPS MAY REMAIN JUST COLD ENOUGH WITH PRECIP
INDUCED COOLING TO MAINTAIN SNOW. GRASSY AREAS WOULD BE THE MAIN
AREA OF ACCUMULATION WITH SOME BRIEF SLUSH ACCUMULATION ON LESS
TRAVELLED ROADWAYS POSSIBLE. UNFORTUNATELY...THERE IS STILL MUCH
UNCERTAINTY IN IF ALL SNOW WILL OCCUR FOR ANY LENGTH OF TIME GIVEN
THE MARGINAL TEMPS ETC. AHEAD OF THE PRECIP BUT THE ABOVE OUTLINED
AREA LOOKS MOST SUSCEPTIBLE. AREAS FURTHER SOUTH LOOK TO BE RAIN.
MDB
//PREV DISCUSSION...
343 AM CDT
USUALLY IT WOULD BE ANOTHER FEW WEEKS OR EVEN LONGER IN OUR
FORECAST AREA BEFORE INTERROGATING SEVERAL OF THE FORECAST
INGREDIENTS THAT WERE THE FOCUS THIS MORNING. CHALLENGES WERE
LOOKING AT PRECIP TYPE AND INTENSITY TODAY...TO SEE IF SOME PLACES
COULD GET SOME BRIEF ACCUMULATION NAMELY NEAR THE I-80 /FIRST SUCH
ACCUMULATION IN OVER 15 YEARS AND LONGER FOR SOME/...AND THEN
LOOKING AT LAKE EFFECT PRECIP POTENTIAL AND TYPE FOR MAINLY PORTER
COUNTY INDIANA LATE TONIGHT AND WEDNESDAY MORNING.
SYNOPSIS...VIGOROUS SHORT WAVE ENTERING WESTERN IA EARLY THIS
MORNING ON A 120+ JET IS BEGINNING TO CURL MORE SE AROUND THE BASE
OF THE LONG WAVE TROUGH RESPONSIBLE FOR OUR COLD LATE OCTOBER
SNAP. A SURFACE REFLECTION IS DEPICTED IN OBSERVATIONS WITH A
BROAD LOW ACROSS WESTERN IA WHICH WILL TIGHTEN AND DEEPEN THROUGH
THIS MORNING. SOME LIGHT RAIN IS SEEN ACROSS PARTS OF CENTRAL AND
WESTERN IA IN THE WARM AIR ADVECTION FLANK OF THIS CLIPPER.
MODEL PREFERENCE...MODEL GUIDANCE IS IN GOOD GENERAL AGREEMENT
OF THIS WAVE TRANSITIONING EAST SOUTHEAST THIS AFTERNOON ACROSS
CENTRAL IL WITH SOME VARIABILITY IN LATITUDE OF ITS KEY
FEATURES...WHICH OF COURSE DICTATE ALL THE KEY ELEMENTS SUCH AS
PLACEMENT OF HEAVIER PRECIP AND SUBTLE THERMAL DIFFERENCES THAT
INFLUENCE WHERE TRANSITION TO RA/SN MIGHT OCCUR. HAD LEANED A
LITTLE MORE TO THE 00Z NAM WHICH HAS VERY CLOSE SUPPORT BY THE 00Z
EC AND THE 03Z SREF MEAN. IT SHOULD BE NOTED THIS 00Z NAM HAD
SHIFTED SLIGHTLY FURTHER SOUTH THAN ITS PRECEDING 18Z RUN...AND
NOW THE 06Z SOLUTION HAS EVEN SHIFTED A BIT FURTHER SOUTH. THE
TREND FROM THAT OF TIGHTENING THE PRECIP GRADIENT ON THE NORTH
SIDE HAS ALSO BEEN NOTED WHICH MAKES GOOD SENSE WITH HOW THIS
SYSTEM IS ORIENTED AND ITS GENERALLY COMPACT NATURE AND QUICK
MOVEMENT. THE MAIN POINT WITH THIS IS IT BASICALLY KEEPS PRECIP
OUT OF CHICAGO. HAVE NOT GONE THAT SHARP BUT HAVE TIGHTENED THAT
NORTHERN GRADIENT.
TODAY AND TONIGHT...THE UPPER WARM AND MOIST ASCENT AHEAD OF THE
CLIPPER SHOULD LEAD TO A BLOSSOMING OF RADAR ECHOES ACROSS THE
WESTERN FORECAST AREA BY LATER THIS MORNING. GOOD CONVERGENCE AND
THERMAL GRADIENT TIGHTENING IN THE MID-LEVELS...WITH SUPPORTIVE
LAPSE RATES...WILL LIKELY CREATE SOME TEMPORARY MORE INTENSE WEST-
TO-EAST CORRIDORS. MOST HIGH RESOLUTION GUIDANCE BOTH LOCALLY AND
NATIONALLY TEND TO INDICATE THIS...ALTHOUGH AGAIN WITH
DISCREPANCIES IN HOW FAR NORTH...SOME AS FAR NORTH AS AROUND
I-88...OTHERS TOWARD PEORIA TO BLOOMINGTON/NORMAL. THIS HEAVIER
PRECIP IS IMPORTANT BECAUSE MARGINAL THERMAL PROFILES WOULD NEED
THE DIABATIC COOLING TO THE WET BULB /OR COOLER/ TO ENABLE SNOW TO
MIX IN TO THE SURFACE. HAVE GENERALLY FAVORED THE
LEE/LASALLE/LIVINGSTON COUNTIES THE MOST THIS AFTERNOON...AS THAT
CORRIDOR OF WET BULB COOLING AT THE SURFACE /TEMPS DROPPING INTO
THE MID 30S/ SHOULD BE SHIFTING SOUTHEAST THROUGH THOSE COUNTIES.
IF SNOW CAN MATERIALIZE...TEMPORARY RATES COULD CERTAINLY BE
ENOUGH TO BRING DOWN VISIBILITY QUICKLY...AND ITS POSSIBLE THOUGH
NOT REALLY FAVORED TO SEE SOME LIGHT SLUSHY ACCUMULATION. LATE IN
THE DAY AND THIS EVE THE PROFILES BECOME MORE SUPPORTIVE TO SEE A
MIX ACROSS THE WHOLE AREA...BUT THE OVERALL STRONGER FORCING IS
WEAKENING AS THE CLIPPER TRANSITIONS AWAY. SO REALLY NOT EXPECTING
ANY ACCUMULATION ELSEWHERE IF ANY OTHER PLACES CAN ACTUALLY CHANGE
OVER. IN MUCH OF THE CHICAGO METRO /OUTSIDE OF THE FAR SOUTHWEST
AND SOUTH/ THE PROFILES JUST APPEAR TOO WARM TO SUPPORT A LONG
CHANGEOVER IF ANY GIVEN MORNING MODERATION IN TEMPS.
LAKE EFFECT...IN THE WAKE OF THE CLIPPER AND ITS SURFACE LOW
REFLECTION MOVING INTO INDIANA...WINDS WILL TURN MORE NORTHERLY
AND DOWN THE FETCH OF THE LAKE. IT APPEARS THEIR IS A 6 TO 12 HOUR
WINDOW OF GOOD N-S CONVERGENCE INTO MAINLY NW IN. MODERATE TO
EXTREME LOW-LEVEL INSTABILITY WILL BE IN PLACE OVER THE LAKE
GIVEN 850MB TEMPERATURES OF -4C TO -6C. NAM PROFILES OVER THE LAKE
GIVEN MODIFIED PARCELS NEAR THE SURFACE LAKE TEMPERATURES SUPPORT
CLOUD DEPTHS OF 15K FT. ITS NOTED THIS MORNING THAT THE AIR
TEMPERATURE AT THE SOUTH BUOY IS ONLY 42 DESPITE A WATER
TEMPERATURE OF 60. SO THE INSTABILITY MAY NOT BE AS EXTREME AS SOME
MODIFIED GUIDANCE SHOWS...BUT STILL AMPLE FOR DECENT SHOWERS.
PRECIP TYPE IS A REAL CHALLENGE AND AGAIN BASED ON INTENSITY. IT
WOULD SEEM ALONG THE IMMEDIATE LAKE SHORE WITH ONSHORE FLOW IT
WOULD BE TOUGH TO GET EVEN A CHANGEOVER. INLAND THERE IS CERTAINLY
THAT CHANCE AND IF THE CONVERGENCE IS STRONG...THEN THAT
INSTABILITY WILL TRAIN INLAND POTENTIALLY CREATING A PROBLEM FOR
QUICK ACCUMULATION IF COLD ENOUGH WITH HEAVY SUSTAINED RATES.
HAVE ADDED UNDER AN INCH OF ACCUMULATION IN EASTERN PORTER
COUNTY...BUT CERTAINLY THE CHANCE IS THERE FOR MORE. FOR NOW
THOUGH...THERMAL PROFILES ARE AWFULLY MARGINAL AND WITH THE CAVEAT
OF ONSHORE FLOW POTENTIALLY LEADING TO RAIN SHOWERS FOR MUCH OF
THAT TIME.
BEYOND...MORE TRANQUIL CONDITIONS PREVAIL HOWEVER STILL UNDER
NORTHWEST FLOW ALOFT...SO BELOW NORMAL TEMPERATURES CONTINUE. THE
BACK SIDE OF THE TROUGH SHIFTS EAST AS DOES ITS JET...SO THE PATH
FOR SHORT WAVES WILL BE MORE TO THE NORTH AND EAST BY
THURSDAY...MEANING LESS OF A CHANCE FOR PRECIP. LAKE EFFECT
ORIENTATION LOOKS TO BE EAST OF OUR INDIANA COUNTIES ON MOST OF
THESE DAYS.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* RAIN MIXING WITH AND CHANGING OVER TO WET SNOW THIS AFTERNOON
AFTER 19 UTC.
* VIS TO DROP AS LOW AS 1-2 MILES AND CIGS AROUND 1,000 FT FOR A
PERIOD. BETTER CHANCES WILL BE AT MDW.
KJB
//DISCUSSION...UPDATED 18Z...
THE MAIN FORECAST CONCERNS THIS AFTERNOON IS THE SNOW THAT WILL BE
AFFECTING THE EASTERN TERMINALS THROUGH THE AFTERNOON. ALTHOUGH THE
SNOW SHOULD NOT RESULT IN ACCUMULATIONS ON RUNWAYS...IT COULD REDUCE
THE VISIBILITIES DOWN TO 1 TO 2 MILES FOR A PERIOD THIS
AFTERNOON...ALONG WITH CIGS AROUND 1,000 FEET...ESPECIALLY AT KMDW
AND KGYY.
IT STILL APPEARS THE HEAVIEST PRECIP WILL BE FAVORED SOUTH WITH THIS
SYSTEM. HOWEVER...THERE IS A BAND OF LIGHTER PRECIP MOVING ACROSS
NORTHERN ILLINOIS AND THIS WILL LIKELY AFFECT ALL THE TERMINALS TO
SOME POINT THIS AFTERNOON. I WENT WITH LOWER VIS AND CIGS AT KMDW
AND KGYY AS THEY STAND THE BEST CHANCES FOR SOME SLIGHTLY HEAVIER
PRECIP. IT COULD BEGIN AS SOME LIGHT RAIN INITIAL...BUT AS
EVAPORATION COOLING TAKES OVER IT SHOULD MIX WITH AND CHANCE OVER
THE SNOW. WITH SNOW LIKELY BECOMING THE MAIN PRECIP TYPE...THIS
SHOULD LEAD TO LOWER VISIBILITIES THAN PREVIOUSLY FORECAST.
WIND DIRECTIONS WILL BE A CHALLENGE THIS AFTERNOON...WITH THE LOW
MOVING TO THE SOUTH. IT APPEARS THEY WILL BE OUT OF THE SOUTHWEST
THROUGH THE AFTERNOON...THEN SHIFTING MORE NORTHWEST TONIGHT. WIND
SPEEDS SHOULD REMAIN AT OR LESS THEN 10KT.
CONDITIONS SHOULD IMPROVE THIS EVENING AS THE SYSTEM SHIFTS EAST OF
THE AREA.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN PRECIP AFFECTING THE TERMINALS WITH RAIN/SNOW
* MEDIUM CONFIDENCE IN PERIOD OF 1 TO 2 SM VIS RANGE THIS
AFTERNOON IN -SN...ESPECIALLY AT KMDW.
* LOW TO MEDIUM CONFIDENCE IN LOW MVFR CIGS AROUND 1,000 FT
THROUGH THE AFTERNOON...WITH IFR POSSIBLE.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT THROUGH FRIDAY...VFR.
SATURDAY...MVFR POSSIBLE LATE.
SUNDAY...VFR.
MONDAY...CHANCE OF RAIN.
JEE
&&
.MARINE...
237 PM CDT
FAIRLY STEADY STATE CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE
WEEK. LOW PRESSURE WILL CONTINUE TO SPIN AND GRADUALLY SHIFT EAST
OVER EASTERN CANADA WHILE HIGH PRESSURE BUILDS SOUTHEAST FROM THE
NORTHERN PLAINS TODAY TO THE LOWER TO MID MISSISSIPPI VALLEY BY
FRIDAY. THE PERSISTENT MODERATE NORTHWESTERLY GRADIENT THROUGH THE
PERIOD WILL RESULT IN NORTHWEST WINDS OF 15 TO 25 KT OVER MOST OF
THE LAKE THROUGH FRIDAY...WITH SOME MINOR UNDULATIONS AS WEAK
PERTURBATIONS MOVE THROUGH THE REGION. WITH TEMPORARY WEAKER WINDS
TODAY OVER THE SOUTHERN PORTIONS OF THE LAKE...WILL ALLOW THE SMALL
CRAFT ADVISORY TO EXPIRE FOR THIS AFTERNOON...BUT NORTHERLY WINDS
PICKING UP AGAIN OVERNIGHT WILL ALLOW WAVES TO ONCE AGAIN
GROW...THUS WILL HOIST A NEW SMALL CRAFT ADVISORY GOING INTO EFFECT
EARLY WEDNESDAY MORNING. LOW PRESSURE WILL DROP SOUTHEAST ACROSS THE
CANADIAN PRAIRIES AND OVER LAKE SUPERIOR EARLY SATURDAY WITH WINDS
AT LEAST BRIEFLY RETURNING TO SOUTHWEST FRIDAY NIGHT THROUGH LATE
MORNING SATURDAY. A FRONT SWEEPING ACROSS THE LAKE SATURDAY
AFTERNOON WILL THEN TURN WINDS BACK TO THE NORTHWEST THROUGH THE
REMAINDER OF THE WEEKEND. TRANSIENT HIGH PRESSURE QUICKLY MOVES
ACROSS THE LAKE MONDAY ALLOWING WINDS TO DIMINISH...BEFORE TURNING
SOUTHEASTERLY AGAIN AHEAD OF A BROAD AREA OF LOW PRESSURE DEVELOPING
OVER THE PLAINS.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...5 AM WEDNESDAY
TO 3 PM FRIDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...5 AM WEDNESDAY TO
10 PM WEDNESDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
222 PM CDT Tue Oct 22 2013
.DISCUSSION...
ISSUED 210 PM CDT Tue Oct 22 2013
Latest surface analysis has low pressure just north of Quincy with
a warm front extending from the low over extreme southwest Illinois.
A large area of rain extended mainly north and east of the surface
low with a narrow band of snow falling just north of our forecast
area to the Quad Cities where a couple of inches of wet snow
accumulated thru the morning hours. We did receive a report of some
snow in Altona in northern Knox county this morning but temperatures
were well into the 30s at that time.
The main forecast concern in the short term will be overnight low
temps the next several nights with the potential for widespread
freezing temperatures by tomorrow morning, and especially late Thu
night into Friday morning when surface high pressure will be
approaching our area. In the longer range...our cold pattern will
begin to break down as the deep vortext north of the Great Lakes
shifts off the north and east of the region by late in the weekend
and into early next week with our 500 mb flow turning more southwesterly
increasing not only our temperatures but also our rain chances.
SHORT TERM...Tonight through Friday
Surface low forecast by models to track east-southeast to near
Mattoon by early this evening, and then finally east of our forecast
area by midnight. With the track a bit further north than previous
forecasts had indicated, the low levels look to stay too warm to
support any snow before we lose the ice crystals in the upper portions
of the cloud. The better 700-500 mb QG forcing shifts off to our east
rather quickly early this evening with quite a bit of wrap around
moisture/clouds in the wake of the system. Forecast soundings and
time-height cross sections indicate some clearing taking place by
midnight over our northwest and then working east and south later
tonight. The NAM-WRF 850 temps showing some decent cold air advection
overnight as the surface wave shifts into Kentucky by Wednesday morning.
With the clear sky and diminishing winds overnight, it appears the setup
would support more widespread freezing temperatures than what was
experienced last night so went ahead and issued a Freeze Warning for
areas north of I-70. Morning lows will range from roughly 25 to 30
degrees over a larger area and for a longer duration than last night.
Cloud cover will be slower to clear out along and south of I-70 so
will hold off any headlines in that area tonight as lows dip into
the lower to middle 30s. Next fast moving clipper will track southeast
into the region by late Wednesday morning into the afternoon hours
with an increase in clouds during the day. However, the moisture and
lift associated with this upper wave is not nearly as strong as today`s
forcing, as a result, will continue with only slight chance pops during
the late morning thru the early evening hours. As far as overnight
temps late Wed night into Thursday morning, forecast soundings continue
to indicate quite a bit of low level moisture in the wake of the clipper
system on Wednesday, so guid temps not as cold as tonight across the
southeast with lows in the low to mid 30s once again. It appears the
better chance for widespread freezing temperatures in the southeast
would be on Friday morning as another cold high pressure area approaches
from the west. Morning lows will drop to between 27 and 30 degrees in
areas along and south of I-70, as a result, a Freeze Watch has been
issued for the far southeast for the early morning hours of Friday.
After a cold start on Friday, high pressure will keep the weather
cool and dry across the entire area as we head into the weekend.
LONG TERM...Saturday through Tuesday
Medium range models continue to suggest a major pattern change to
take place early next week as the deep vortex north of the Great
Lakes shifts off to our east and north. 500 mb heights will be on
the rise across our area in response to a trof that is forecast to
develop to our west and close off a low in the Rockies by late
Tuesday and track SSE into the southern Plains. This will bring in
much warmer air to the region with afternoon temperatures approaching
60 on Monday and well into the 60s by Tuesday. Shower chances will
begin to increase, especially Monday night through Tuesday as a
series of shortwaves are forecast to eject from the trof to our
southwest and track northeast into forecast area.
Smith
&&
.AVIATION...
ISSUED 1237 PM CDT Tue Oct 22 2013
Main aviation forecast challenges will be timing of potential IFR
ceilings into the area later this afternoon and evening...and
timing the clearing trend later tonight.
Low pressure currently over southeast Iowa will track E/SE across
central Illinois this afternoon...accompanied by a band of light
rain. Once the low passes, winds will swing around to the N/NE and
should pull IFR ceilings currently in place across much of Iowa
and northwest Illinois into the area. Model guidance is in
disagreement, with the GFS and NAM indicating MVFR or even VFR
ceilings persisting. Given latest satellite trends, prefer the
more pessimistic HRRR which brings the lower ceilings into central
Illinois behind the departing low. Based on HRRR timing, have
introduced IFR ceiling at KPIA by 21z, then further east to KCMI
by 02z. Clouds will be rather slow to clear tonight, with the HRRR
hanging on to IFR conditions until around midnight. Skies should
scatter at KPIA by 05z, then eastward to KCMI by around 10z.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH from late Thursday night through Friday morning FOR
ILZ062-063-066>068-071>073.
FREEZE WARNING from 1 AM to 8 AM CDT Wednesday FOR ILZ027>031-
036>038-040>057-061.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1220 PM CDT TUE OCT 22 2013
.UPDATE...
ISSUED AT 1215 PM CDT TUE OCT 22 2013
DESPITE WEAK FORCING...PRECIPITATION HAS LINGERED ACROSS MUCH OF
CWA THROUGH THE MORNING. THIS WILL CONTINUE TO PUSH SLOWLY
SOUTHEAST THROUGH THE REMAINDER OF THE AFTERNOON. HAVE THEREFORE
INCREASED POPS THROUGH THE AFTERNOON. IN ADDITION...WITH COLDER
AIR WORKING IN BEHIND SYSTEM PRECIPITATION HAS CHANGED TO SNOW
ACROSS MUCH OF CENTRAL IOWA...AND HAVE INTRODUCED POSSIBLE
ACCUMULATIONS NEAR 0.1 OF AN INCH A FEW COUNTIES FURTHER SOUTH.
&&
.SHORT TERM /TODAY/...
ISSUED AT 341 AM CDT TUE OCT 22 2013
MAIN CONCERN TODAY WILL OBVIOUSLY BE EVOLUTION OF CURRENT SYSTEM
PASSING THROUGH THE MO VALLEY. DAKOTAS SHORT WAVE/PV ANOMALY
CONTINUES TO STRENGTHEN AS IT APPROACHES WRN IA. ASSOCIATED PRECIP
IS CURRENTLY SOMEWHAT PATCHY...LIKELY DUE TO FAIRLY LOW STATIC
STABILITIES...BUT IS EXPECTED TO ORGANIZE SOMEWHAT MORE LATER THIS
MORNING. FORCING IS DEEP...DRIVEN KINEMATICALLY BY DPVA AND
DIVERGENCE IS LEFT EXIT REGION OF SASKATCHEWAN INTO HIGH PLAINS
JET SEGMENT. THERMODYNAMIC FORCING IS CENTERED INTO IA AND
CURRENTLY NOT THAT STRONG HOWEVER BUT MODELS DO STRENGTHEN THE
THETA-E ADVECTION AND FRONTOGENETICAL FORCING INTO THE MORNING.
THIS COUPLED FORCING WILL RESULT IN INCREASED DENDRITIC GROWTH ZONE
/DGZ/ UPWARD MOTION. MODEL DEPICTIONS OF THIS...LOOKING AT
290-300K ISENT LAYER...ARE SOMEWHAT PROBLEMATIC HOWEVER AND
AFOREMENTIONED LOW STATIC STABILITIES HAVE RESULTED IN COMPACT
MODEL BULLSEYES OF LIFT WHICH ARE DIFFICULT TO EASILY TRANSLATE
INTO HIGHER SNOW RATIOS AND RESULTANT SENSIBLE WEATHER. AREAS OF
HIGHER SNOW RATES MAY END UP BEING NEAR CONVECTIVE AND SOMEWHAT
ISOLATED. TO LOWER CONFIDENCE EVEN FURTHER...LOWEST 500M TEMPS
HOVER RIGHT AROUND CRITICAL RAIN/SNOW VALUES WHICH ARE CO-LOCATED
WITH THE DGZ LIFT. THIS MAKES RAIN/SNOW LINE UNCERTAIN AND WHETHER
THE DGZ OMEGA WILL BE REALIZED IN RAIN OR SNOW. TAKING A BLEND OF
THE HIGHER RES RAP AND NAM WOULD SUGGEST THE BEST LOCATION FOR
ACCUMULATING SNOWS WOULD BE SIMILAR TO PREVIOUS TRACK FROM NW IA
SEWD TO NEAR WATERLOO AND MARSHALLTOWN. STILL HAVE ACCUMS OF AN
INCH OR LESS...WITH A POCKET OF HIGHER AMOUNTS NEAR AN IOWA
FALLS/MARSHALLTOWN/WATERLOO TRIANGLE WHERE SNOW MAY BRIEFLY
INTENSIFY AROUND 12Z OR 15Z. CONFIDENCE IN SNOW AMOUNTS IS QUITE
LOW HOWEVER DUE TO CONCERNS ABOVE AND MELTING ISSUES WITH ROAD
SURFACE TEMPS STILL 35F OR HIGHER AND THE GROUND WARM AS WELL.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 341 AM CDT TUE OCT 22 2013
MAIN FORECAST CONCERN IS WITH WEAK SHORTWAVE TO BRING ADDITIONAL
PRECIP CHANCES ON WEDNESDAY AND THEN CONTINUED COLD TEMPERATURES
THROUGH THE END OF THE WORK WEEK AND INTO THE WEEKEND.
TONIGHT THROUGH WEDNESDAY...THE 22.00Z MODELS RUNS IN DECENT
AGREEMENT WITH BRINGING WEAK VORT MAX FURTHER SOUTH AND CAUSED
FOR A SHIFT IN POPS SOUTHWEST LEAVING THE NORTHEAST PORTIONS OF
THE FORECAST AREA DRY TOMORROW. THERE IS A SMALL WINDOW FOR SNOW
POTENTIAL DURING THE MORNING...ROUGHLY BETWEEN 12-15Z WEDNESDAY
WHEN THE COLUMN BECOMES SATURATED AND REMAINS BELOW
FREEZING AND ENOUGH FORCING IN THE SNOW GROWTH ZONE TO GENERATE
SNOW. THIS WILL BE MAINLY OVER WEST CENTRAL TO NORTHWEST IOWA.
HOWEVER...LOW CONFIDENCE WITH MUCH...IF ANY SNOW ACCUMULATION AS
SURFACE TEMPERATURES LOOK TO QUICKLY RISE ABOVE FREEZING AND
FORCING QUICKLY MOVES SOUTH. AS A RESULT...DECREASED SNOW AMOUNTS
TO LESS THAN HALF AN INCH. THETA-E ADVECTION AND ISENTROPIC LIFT
WILL QUICKLY MOVES FROM NORTHWEST IOWA TO SOUTHEAST IOWA DURING
THE DAY WEDNESDAY. NAM/GFS HAVE DECENT FRONTOGENETICAL FORCING
BETWEEN 750-600MB BY 12Z IN NORTHWEST IOWA AND THEN TRANSITION THE
FORCING INTO SOUTH-CENTRAL TO SOUTHEAST PORTIONS OF THE FORECAST
AREA BY 18Z. WITH THE QUICKER MOVEMENT OF THE SYSTEM...DECREASED
POPS OVER THE WEST AND NORTH PAST 21Z.
THURSDAY THROUGH MONDAY....LARGE SURFACE HIGH BUILDS INTO THE
REGION UNDERNEATH NORTHWEST FLOW ALOFT THROUGH SATURDAY BEFORE
THE GFS/ECMWF BRING A DRY COLD FRONT ACROSS THE STATE SOMETIME
SATURDAY. NEXT LONGWAVE TROUGH BEGINS TO DIG INTO THE WESTERN U.S.
BY EARLY NEXT WEEK PLACING AN INVERTED SURFACE TROUGH OVER IOWA BY
MONDAY. THIS WILL BE THE NEXT BEST CHANCE OF PRECIP TO THE
FORECAST AREA.
&&
.AVIATION...22/18Z
ISSUED AT 1215 PM CDT TUE OCT 22 2013
LIGHT PRECIPITATION WILL LINGER WITH MVFR CEILING AND VISIBILITIES
AT SITES...WITH EXCEPTION OF KMCW WHICH WILL REMAIN NORTH AND IN
VFR CONDITIONS. BEHIND PRECIPITATION CEILINGS WILL SLOWLY LIFT BACK
TO VFR CEILINGS...GENERALLY NEAR 00Z AT SITES. WINDS WILL SHIFT TO
THE WEST THROUGH THE PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...AWB
SHORT TERM...SMALL
LONG TERM...PODRAZIK
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
357 AM CDT TUE OCT 22 2013
.SHORT TERM /TODAY/...
ISSUED AT 341 AM CDT TUE OCT 22 2013
MAIN CONCERN TODAY WILL OBVIOUSLY BE EVOLUTION OF CURRENT SYSTEM
PASSING THROUGH THE MO VALLEY. DAKOTAS SHORT WAVE/PV ANOMALY
CONTINUES TO STRENGTHEN AS IT APPROACHES WRN IA. ASSOCIATED PRECIP
IS CURRENTLY SOMEWHAT PATCHY...LIKELY DUE TO FAIRLY LOW STATIC
STABILITIES...BUT IS EXPECTED TO ORGANIZE SOMEWHAT MORE LATER THIS
MORNING. FORCING IS DEEP...DRIVEN KINEMATICALLY BY DPVA AND
DIVERGENCE IS LEFT EXIT REGION OF SASKATCHEWAN INTO HIGH PLAINS
JET SEGMENT. THERMODYNAMIC FORCING IS CENTERED INTO IA AND
CURRENTLY NOT THAT STRONG HOWEVER BUT MODELS DO STRENGTHEN THE
THETA-E ADVECTION AND FRONTOGENETICAL FORCING INTO THE MORNING.
THIS COUPLED FORCING WILL RESULT IN INCREASED DENDRITIC GROWTH ZONE
/DGZ/ UPWARD MOTION. MODEL DEPICTIONS OF THIS...LOOKING AT
290-300K ISENT LAYER...ARE SOMEWHAT PROBLEMATIC HOWEVER AND
AFOREMENTIONED LOW STATIC STABILITIES HAVE RESULTED IN COMPACT
MODEL BULLSEYES OF LIFT WHICH ARE DIFFICULT TO EASILY TRANSLATE
INTO HIGHER SNOW RATIOS AND RESULTANT SENSIBLE WEATHER. AREAS OF
HIGHER SNOW RATES MAY END UP BEING NEAR CONVECTIVE AND SOMEWHAT
ISOLATED. TO LOWER CONFIDENCE EVEN FURTHER...LOWEST 500M TEMPS
HOVER RIGHT AROUND CRITICAL RAIN/SNOW VALUES WHICH ARE CO-LOCATED
WITH THE DGZ LIFT. THIS MAKES RAIN/SNOW LINE UNCERTAIN AND WHETHER
THE DGZ OMEGA WILL BE REALIZED IN RAIN OR SNOW. TAKING A BLEND OF
THE HIGHER RES RAP AND NAM WOULD SUGGEST THE BEST LOCATION FOR
ACCUMULATING SNOWS WOULD BE SIMILAR TO PREVIOUS TRACK FROM NW IA
SEWD TO NEAR WATERLOO AND MARSHALLTOWN. STILL HAVE ACCUMS OF AN
INCH OR LESS...WITH A POCKET OF HIGHER AMOUNTS NEAR AN IOWA
FALLS/MARSHALLTOWN/WATERLOO TRIANGLE WHERE SNOW MAY BRIEFLY
INTENSIFY AROUND 12Z OR 15Z. CONFIDENCE IN SNOW AMOUNTS IS QUITE
LOW HOWEVER DUE TO CONCERNS ABOVE AND MELTING ISSUES WITH ROAD
SURFACE TEMPS STILL 35F OR HIGHER AND THE GROUND WARM AS WELL.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 341 AM CDT TUE OCT 22 2013
MAIN FORECAST CONCERN IS WITH WEAK SHORTWAVE TO BRING ADDITIONAL
PRECIP CHANCES ON WEDNESDAY AND THEN CONTINUED COLD TEMPERATURES
THROUGH THE END OF THE WORK WEEK AND INTO THE WEEKEND.
TONIGHT THROUGH WEDNESDAY...THE 22.00Z MODELS RUNS IN DECENT
AGREEMENT WITH BRINGING WEAK VORT MAX FURTHER SOUTH AND CAUSED
FOR A SHIFT IN POPS SOUTHWEST LEAVING THE NORTHEAST PORTIONS OF
THE FORECAST AREA DRY TOMORROW. THERE IS A SMALL WINDOW FOR SNOW
POTENTIAL DURING THE MORNING...ROUGHLY BETWEEN 12-15Z WEDNESDAY
WHEN THE COLUMN BECOMES SATURATED AND REMAINS BELOW
FREEZING AND ENOUGH FORCING IN THE SNOW GROWTH ZONE TO GENERATE
SNOW. THIS WILL BE MAINLY OVER WEST CENTRAL TO NORTHWEST IOWA.
HOWEVER...LOW CONFIDENCE WITH MUCH...IF ANY SNOW ACCUMULATION AS
SURFACE TEMPERATURES LOOK TO QUICKLY RISE ABOVE FREEZING AND
FORCING QUICKLY MOVES SOUTH. AS A RESULT...DECREASED SNOW AMOUNTS
TO LESS THAN HALF AN INCH. THETA-E ADVECTION AND ISENTROPIC LIFT
WILL QUICKLY MOVES FROM NORTHWEST IOWA TO SOUTHEAST IOWA DURING
THE DAY WEDNESDAY. NAM/GFS HAVE DECENT FRONTOGENETICAL FORCING
BETWEEN 750-600MB BY 12Z IN NORTHWEST IOWA AND THEN TRANSITION THE
FORCING INTO SOUTH-CENTRAL TO SOUTHEAST PORTIONS OF THE FORECAST
AREA BY 18Z. WITH THE QUICKER MOVEMENT OF THE SYSTEM...DECREASED
POPS OVER THE WEST AND NORTH PAST 21Z.
THURSDAY THROUGH MONDAY....LARGE SURFACE HIGH BUILDS INTO THE
REGION UNDERNEATH NORTHWEST FLOW ALOFT THROUGH SATURDAY BEFORE
THE GFS/ECMWF BRING A DRY COLD FRONT ACROSS THE STATE SOMETIME
SATURDAY. NEXT LONGWAVE TROUGH BEGINS TO DIG INTO THE WESTERN U.S.
BY EARLY NEXT WEEK PLACING AN INVERTED SURFACE TROUGH OVER IOWA BY
MONDAY. THIS WILL BE THE NEXT BEST CHANCE OF PRECIP TO THE
FORECAST AREA.
&&
.AVIATION...22/06Z
ISSUED AT 1158 PM CDT MON OCT 21 2013
STORM SYSTEM STILL ON TRACK TO IMPACT THE AREA TONIGHT INTO
TUESDAY MORNING. KFOD AND KALO STILL HAVE POTENTIAL FOR IFR TO
MVFR CIGS AND VSBYS WITH SNOW. A PERIOD MVFR CIGS AND
PRECIPITATION ARE EXPECTED AT THE OTHER LOCATIONS AS WELL. A
SWITCH TO NORTHWEST WINDS AND RISING CIGS WILL ARRIVE BY THE
AFTERNOON.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...PODRAZIK
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS WICHITA KS
1154 AM CDT TUE OCT 22 2013
.UPDATE...
ISSUED AT 712 AM CDT TUE OCT 22 2013
THIS MORNING:
THE PURPOSE FOR THE UPDATE IS TWO-FOLD:
1) TO REMOVE SPRINKLES FROM PARTS OF CENTRAL & SOUTH-CENTRAL KS.
2) TO ADJUST CLOUD COVER TO REFLECT SATELLITE TRENDS TO FOCUS
CLOUD COVER OVER SE KS THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 333 AM CDT TUE OCT 22 2013
TODAY:
ADDED A FEW SPRINKLES THIS MORNING BASED ON RADAR/SURFACE
OBSERVATIONS...WITH RUC SHOWING TRANSIENT LIFT MOISTURE TRACKING
ACROSS EASTERN EDGE OF FORECAST AREA EARLY THIS MORNING.
OTHERWISE IT IS A CHALLENGING TEMPERATURE FORECAST WITH A LOT
RIDING ON WIND DIRECTION AND CLOUDS. RELATIVELY DRY AIRMASS AND
POSSIBLE DOWNSLOPE FLOW COULD REALLY BOOST TEMPERATURES THIS
AFTERNOON. GIVEN SLIGHT COOL BIAS YESTERDAY AND WHAT SHOULD BE
FAIRLY GOOD BREAKS IN CLOUDS LATER...WILL HEDGE A COUPLE DEGREES
WARMER TODAY AND HOPEFULLY MINIMIZE ERROR EITHER WAY.
TONIGHT:
RIDGE AXIS WILL SETTLE OVER AREA WITH A SHARP FALL IN TEMPERATURES
EARLY. SOME RETURN FLOW/CLOUDS MAY DEVELOP AFTER MIDNIGHT ACROSS
WESTERN SECTIONS. HOWEVER CONDITIONS APPEAR FAVORABLE FOR
WIDESPREAD FROST OVER FLINT HILLS/SOUTHEAST KS WHERE WINDS WILL
LIKELY REMAIN NEAR CALM ALL NIGHT. WILL HOIST HEADLINES FOR FROST
ADVISORY IN MOST LIKELY AREAS AND LET DAY SHIFT ADJUST WESTWARD IF
NEEDED.
WED-THU:
QUICK WARM-UP SHOULD COMMENCE ON WED WITH GOOD WARMING JUST AHEAD
OF NEXT FRONT THAT TRAVERSE MOST OF THE AREA DURING THE DAY.
TEMPERATURES WILL LIKELY FALL IN THE AFTERNOON ACROSS NORTHERN
HALF OF THE AREA AND WILL HAVE NON DIURNAL TEMPERATURES IN GRIDS.
TOUGH CALL ON TEMPERATURES WED NIGHT WITH WIND INITIALLY...BUT
WITH RIDGING BUILDING INTO AREA...MAY SEE TEMPERATURES TUMBLE
TOWARDS DAYBREAK...MOST LIKELY IN SOUTHEAST KS. COLD AIR ADVECTION
CONTINUES ON THU WITH MAXES 10-15 DEGREE COOLER THAN WED. LACK OF
MOISTURE SHOULD PRECLUDE ANY MENTION OF PRECIPITATION. -HOWERTON
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 333 AM CDT TUE OCT 22 2013
MEDIUM RANGE MODELS STILL IN FAIRLY GOOD AGREEMENT GIVEN THE
TYPICAL ISSUES OF TIMING SHORTWAVES IN NORTHWEST FLOW. RETURN
FLOW ON FRI...WITH COLD FRONT MOVING THROUGH ON SAT. RETURN FLOW
DEVELOPS SUN NIGHT AND PERSISTS INTO MON. SOME DIFFERENCES IN
TIMING OF FRONT...BUT SMALL CHANCES CERTAINLY JUSTIFIED ON MON
ACROSS SE KS. GIVEN RETURN OF CLOUDS AND INFLUX OF MOISTURE...HAVE
BUMPED UP LOWS FOR MON. DIURNAL RANGE MAY BE EVEN MORE LIMITED ON
MON IN SE KS WHERE LOW CLOUDS AND PRECIPITATION COULD PERSIST MOST
OF THE DAY. -HOWERTON
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1150 AM CDT TUE OCT 22 2013
NORTHWESTERLY WINDS WILL GUST TO 24-30 KT THIS AFTERNOON...BEFORE
DIMINISHING AND BECOMING LIGHT NORTHEASTERLY THIS EVENING. WINDS
WILL THEN BECOME SOUTH-SOUTHWESTERLY BY LATE WEDNESDAY MORNING.
SOME MID-LEVEL ALTOCUMULUS MAY AFFECT ESPECIALLY NORTHEASTERN KS
TONIGHT IN THE NORTHWEST FLOW ALOFT.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 70 39 71 38 / 0 0 0 0
HUTCHINSON 70 38 69 37 / 0 0 0 0
NEWTON 69 38 69 36 / 0 0 0 0
ELDORADO 69 35 69 36 / 10 0 0 0
WINFIELD-KWLD 71 37 73 38 / 0 0 0 0
RUSSELL 67 37 67 34 / 0 0 0 0
GREAT BEND 68 37 68 34 / 0 0 0 0
SALINA 67 36 69 36 / 0 0 0 0
MCPHERSON 69 37 69 36 / 0 0 0 0
COFFEYVILLE 69 36 69 38 / 10 0 0 0
CHANUTE 67 33 65 35 / 10 0 10 0
IOLA 65 32 65 35 / 10 0 10 0
PARSONS-KPPF 67 33 67 34 / 10 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 1 AM TO 9 AM CDT WEDNESDAY FOR KSZ052-053-
069>072-094>096-099-100.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
712 AM CDT TUE OCT 22 2013
.UPDATE...
ISSUED AT 712 AM CDT TUE OCT 22 2013
THIS MORNING:
THE PURPOSE FOR THE UPDATE IS TWO-FOLD:
1) TO REMOVE SPRINKLES FROM PARTS OF CENTRAL & SOUTH-CENTRAL KS.
2) TO ADJUST CLOUD COVER TO REFLECT SATELLITE TRENDS TO FOCUS
CLOUD COVER OVER SE KS THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 333 AM CDT TUE OCT 22 2013
TODAY:
ADDED A FEW SPRINKLES THIS MORNING BASED ON RADAR/SURFACE
OBSERVATIONS...WITH RUC SHOWING TRANSIENT LIFT MOISTURE TRACKING
ACROSS EASTERN EDGE OF FORECAST AREA EARLY THIS MORNING.
OTHERWISE IT IS A CHALLENGING TEMPERATURE FORECAST WITH A LOT
RIDING ON WIND DIRECTION AND CLOUDS. RELATIVELY DRY AIRMASS AND
POSSIBLE DOWNSLOPE FLOW COULD REALLY BOOST TEMPERATURES THIS
AFTERNOON. GIVEN SLIGHT COOL BIAS YESTERDAY AND WHAT SHOULD BE
FAIRLY GOOD BREAKS IN CLOUDS LATER...WILL HEDGE A COUPLE DEGREES
WARMER TODAY AND HOPEFULLY MINIMIZE ERROR EITHER WAY.
TONIGHT:
RIDGE AXIS WILL SETTLE OVER AREA WITH A SHARP FALL IN TEMPERATURES
EARLY. SOME RETURN FLOW/CLOUDS MAY DEVELOP AFTER MIDNIGHT ACROSS
WESTERN SECTIONS. HOWEVER CONDITIONS APPEAR FAVORABLE FOR
WIDESPREAD FROST OVER FLINT HILLS/SOUTHEAST KS WHERE WINDS WILL
LIKELY REMAIN NEAR CALM ALL NIGHT. WILL HOIST HEADLINES FOR FROST
ADVISORY IN MOST LIKELY AREAS AND LET DAY SHIFT ADJUST WESTWARD IF
NEEDED.
WED-THU:
QUICK WARM-UP SHOULD COMMENCE ON WED WITH GOOD WARMING JUST AHEAD
OF NEXT FRONT THAT TRAVERSE MOST OF THE AREA DURING THE DAY.
TEMPERATURES WILL LIKELY FALL IN THE AFTERNOON ACROSS NORTHERN
HALF OF THE AREA AND WILL HAVE NON DIURNAL TEMPERATURES IN GRIDS.
TOUGH CALL ON TEMPERATURES WED NIGHT WITH WIND INITIALLY...BUT
WITH RIDGING BUILDING INTO AREA...MAY SEE TEMPERATURES TUMBLE
TOWARDS DAYBREAK...MOST LIKELY IN SOUTHEAST KS. COLD AIR ADVECTION
CONTINUES ON THU WITH MAXES 10-15 DEGREE COOLER THAN WED. LACK OF
MOISTURE SHOULD PRECLUDE ANY MENTION OF PRECIPITATION. -HOWERTON
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 333 AM CDT TUE OCT 22 2013
MEDIUM RANGE MODELS STILL IN FAIRLY GOOD AGREEMENT GIVEN THE
TYPICAL ISSUES OF TIMING SHORTWAVES IN NORTHWEST FLOW. RETURN
FLOW ON FRI...WITH COLD FRONT MOVING THROUGH ON SAT. RETURN FLOW
DEVELOPS SUN NIGHT AND PERSISTS INTO MON. SOME DIFFERENCES IN
TIMING OF FRONT...BUT SMALL CHANCES CERTAINLY JUSTIFIED ON MON
ACROSS SE KS. GIVEN RETURN OF CLOUDS AND INFLUX OF MOISTURE...HAVE
BUMPED UP LOWS FOR MON. DIURNAL RANGE MAY BE EVEN MORE LIMITED ON
MON IN SE KS WHERE LOW CLOUDS AND PRECIPITATION COULD PERSIST MOST
OF THE DAY. -HOWERTON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 712 AM CDT TUE OCT 22 2013
EXCEPT FOR NW WINDS THAT WILL INCREASE TO 15-20KTS ~18Z ALL AREAS
TO SHOULD GOOD WEATHER WITH CLOUDINESS LIMITED TO ~8,000FT ALTOCU.
THE NW WINDS WILL QUICKLY DIMINISH EARLY THIS EVENING AS THEY SHIFT
SLOWLY TO THE N.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 68 39 71 38 / 0 0 0 0
HUTCHINSON 67 38 69 37 / 0 0 0 0
NEWTON 65 38 69 36 / 0 0 0 0
ELDORADO 66 35 69 36 / 10 0 0 0
WINFIELD-KWLD 68 37 73 38 / 0 0 0 0
RUSSELL 66 37 67 34 / 0 0 0 0
GREAT BEND 66 37 68 34 / 0 0 0 0
SALINA 66 36 69 36 / 0 0 0 0
MCPHERSON 66 37 69 36 / 0 0 0 0
COFFEYVILLE 68 36 69 38 / 10 0 0 0
CHANUTE 67 33 65 35 / 10 0 10 0
IOLA 65 32 65 35 / 10 0 10 0
PARSONS-KPPF 67 33 67 34 / 10 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 1 AM TO 9 AM CDT WEDNESDAY FOR KSZ052-053-
069>072-094>096-099-100.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS WICHITA KS
334 AM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 333 AM CDT TUE OCT 22 2013
TODAY:
ADDED A FEW SPRINKLES THIS MORNING BASED ON RADAR/SURFACE
OBSERVATIONS...WITH RUC SHOWING TRANSIENT LIFT MOISTURE TRACKING
ACROSS EASTERN EDGE OF FORECAST AREA EARLY THIS MORNING.
OTHERWISE IT IS A CHALLENGING TEMPERATURE FORECAST WITH A LOT
RIDING ON WIND DIRECTION AND CLOUDS. RELATIVELY DRY AIRMASS AND
POSSIBLE DOWNSLOPE FLOW COULD REALLY BOOST TEMPERATURES THIS
AFTERNOON. GIVEN SLIGHT COOL BIAS YESTERDAY AND WHAT SHOULD BE
FAIRLY GOOD BREAKS IN CLOUDS LATER...WILL HEDGE A COUPLE DEGREES
WARMER TODAY AND HOPEFULLY MINIMIZE ERROR EITHER WAY.
TONIGHT:
RIDGE AXIS WILL SETTLE OVER AREA WITH A SHARP FALL IN TEMPERATURES
EARLY. SOME RETURN FLOW/CLOUDS MAY DEVELOP AFTER MIDNIGHT ACROSS
WESTERN SECTIONS. HOWEVER CONDITIONS APPEAR FAVORABLE FOR
WIDESPREAD FROST OVER FLINT HILLS/SOUTHEAST KS WHERE WINDS WILL
LIKELY REMAIN NEAR CALM ALL NIGHT. WILL HOIST HEADLINES FOR FROST
ADVISORY IN MOST LIKELY AREAS AND LET DAY SHIFT ADJUST WESTWARD IF
NEEDED.
WED-THU:
QUICK WARM-UP SHOULD COMMENCE ON WED WITH GOOD WARMING JUST AHEAD
OF NEXT FRONT THAT TRAVERSE MOST OF THE AREA DURING THE DAY.
TEMPERATURES WILL LIKELY FALL IN THE AFTERNOON ACROSS NORTHERN
HALF OF THE AREA AND WILL HAVE NON DIURNAL TEMPERATURES IN GRIDS.
TOUGH CALL ON TEMPERATURES WED NIGHT WITH WIND INITIALLY...BUT
WITH RIDGING BUILDING INTO AREA...MAY SEE TEMPERATURES TUMBLE
TOWARDS DAYBREAK...MOST LIKELY IN SOUTHEAST KS. COLD AIR ADVECTION
CONTINUES ON THU WITH MAXES 10-15 DEGREE COOLER THAN WED. LACK OF
MOISTURE SHOULD PRECLUDE ANY MENTION OF PRECIPITATION. -HOWERTON
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 333 AM CDT TUE OCT 22 2013
MEDIUM RANGE MODELS STILL IN FAIRLY GOOD AGREEMENT GIVEN THE
TYPICAL ISSUES OF TIMING SHORTWAVES IN NORTHWEST FLOW. RETURN
FLOW ON FRI...WITH COLD FRONT MOVING THROUGH ON SAT. RETURN FLOW
DEVELOPS SUN NIGHT AND PERSISTS INTO MON. SOME DIFFERENCES IN
TIMING OF FRONT...BUT SMALL CHANCES CERTAINLY JUSTIFIED ON MON
ACROSS SE KS. GIVEN RETURN OF CLOUDS AND INFLUX OF MOISTURE...HAVE
BUMPED UP LOWS FOR MON. DIURNAL RANGE MAY BE EVEN MORE LIMITED ON
MON IN SE KS WHERE LOW CLOUDS AND PRECIPITATION COULD PERSIST MOST
OF THE DAY. -HOWERTON
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1141 PM CDT MON OCT 21 2013
FAIRLY QUIET VFR CONDITIONS ANTICIPATED THE NEXT 24 HOURS...WITH
GUSTY NORTHWEST WINDS TUESDAY THE PRIMARY CONCERN. LIGHT SOUTHWEST
WINDS ANTICIPATED TONIGHT...INCREASING SOME TOWARD DAYBREAK AND
GRADUALLY TURNING MORE WESTERLY. COLD FRONT WILL MOVE SOUTHEAST
ACROSS THE REGION TUESDAY MORNING...WITH STRONG/GUSTY NORTHWEST
WINDS IN ITS WAKE. FURTHERMORE...MID-LEVEL CLOUDS WILL BE ON THE
INCREASE FROM THE NORTHWEST OVERNIGHT...WITH SLIGHT CHANCE FOR A
FEW PASSING SPRINKLES FOR MAINLY RSL-SLN. DIURNAL CUMULUS AROUND
6000 FT AGL SHOULD PREVAIL ACROSS THE AREA BY TUESDAY AFTERNOON AS
COOLER AIR ALOFT SETTLES SOUTH.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 68 39 71 38 / 10 0 0 0
HUTCHINSON 67 38 69 37 / 10 0 0 0
NEWTON 65 38 69 36 / 10 0 0 0
ELDORADO 66 35 69 36 / 10 0 0 0
WINFIELD-KWLD 68 37 73 38 / 10 0 0 0
RUSSELL 66 37 67 34 / 0 0 0 0
GREAT BEND 66 37 68 34 / 0 0 0 0
SALINA 66 36 69 36 / 10 0 0 0
MCPHERSON 66 37 69 36 / 10 0 0 0
COFFEYVILLE 68 36 69 38 / 10 0 0 0
CHANUTE 67 33 65 35 / 10 0 10 0
IOLA 65 32 65 35 / 10 0 10 0
PARSONS-KPPF 67 33 67 34 / 10 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 1 AM TO 9 AM CDT WEDNESDAY FOR KSZ052-053-
069>072-094>096-099-100.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
944 PM EDT WED OCT 23 2013
.SYNOPSIS...
A SMALL AREA OF LOW PRESSURE WILL SLIDE WELL SOUTH OF THE REGION
THIS EVENING. AN UPPER LEVEL TROUGH WILL BUILD INTO THE EAST FROM
QUEBEC THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
943 PM UPDATE...CLOUDS ASSOCIATED WITH THE DEFORMATION ZONE WITH
LOW PRES WELL SE OF CAPE COD ARE BRUSHING SRN MAINE THIS EVENING.
THE RAIN ASSOCIATED WITH THE LOW WILL MOSTLY REMAIN OFFSHORE...BUT
MAY BRUSH THE ISLANDS AND COASTAL DOWNEAST FROM ABOUT 05-08Z WITH
A BIT OF -RA. THE LAST OF THE -RA WILL SHIFT WELL EAST OF THE AREA
WELL BEFORE DAYBREAK. CLOUDS IN THE NORTH HAVE BEEN BREAKING UP
WITH THE SKY CLEAR TO P/CLDY MOST AREAS FROM ABOUT KMLT NORTH.
MADE SOME TWEAKS TO THE SKY/POP/WX/WIND GRIDS BASED ON THE LATEST
SATELLITE AND RADAR TRENDS. ALSO LOADED THE PAST FEW HOURS OF
OBSERVED DATA AND INTERPOLATED THROUGH THE REMAINDER OF THE NIGHT.
630 PM UPDATE...THE REGIONAL RADARS ARE LOOKING MORE LIKE LATE
FALL THIS EVENING WITH LAKE EFFECT SHOWERS COMING OFF OF LAKES
ERIE AND ONTARIO WITH A BAND OF RAIN CLIPPING CAPE COD AND THE
ISLANDS FROM AN OFFSHORE STORM.
THE MAIN FORECAST CHALLENGE TONIGHT WILL BE HOW MUCH...IF
ANY...PRECIPITATION CLIPS THE DOWNEAST COAST LATE TONIGHT THROUGH
EARLY THU MORNING. DO HAVE SOME CONCERN IN THAT THE HRRR BRINGS AT
LEAST SOME LIGHT RAIN TO THE COAST AND THE SREF 6-HOUR POPS HAVE A
75 PCT CHANCE OF MEASURABLE RAIN ACROSS THE SOUTHEAST 1/4 OF THE
CWA. FOR THIS UPDATE WILL BEEF UP THE POPS TO LIKELY OVER THE
OUTER WATERS AND TO HIGH CHANCE ALONG THE COAST. IT IS STILL
POSSIBLE THAT THE POPS MAY NEED TO BE ADJUSTED UP FURTHER WITH
SUBSEQUENT UPDATE(S) THIS EVENING.
OTHERWISE...THE PAST FEW HOURS OF OBSERVED DATA WAS LOADED WITH
ONLY SOME MINOR TWEAKS TO THE REMAINING FORECAST ELEMENTS TONIGHT.
PREVIOUS DISCUSSION...
A SMALL WAVE OF LOW PRESSURE TRACKING WELL SOUTH OF THE AREA MAY
BRING SOME LIGHT RAIN TO THE DOWNEAST COAST THIS EVENING. THE LOW
WILL QUICKLY MOVE TO THE EAST, SOUTH OF NOVA SCOTIA LATER TONIGHT.
HIGH PRESSURE BUILDING TOWARD THE EAST COAST IN COMBINATION WITH
LOW PRESSURE OVER QUEBEC WILL BRING GUSTY WEST WINDS LATER TONIGHT
INTO THURSDAY. THIS WILL USHER IN SOME VERY CHILLY AIR AS A LARGE
UPPER LEVEL TROUGH MOVES IN. THURSDAY WILL LIKELY BEGIN PARTLY
CLOUDY TO MOSTLY CLEAR AS A WEAK SURFACE RIDGE MOVES OVER.
STRATOCUMULUS CLOUDS WILL THEN INCREASE FROM THE NORTHWEST
THURSDAY AFTERNOON AS MOISTURE IN THE TROUGH BEGINS TO FLOW INTO
THE REGION. SOME SHOWERS OF RAIN AND POSSIBLY WET SNOW IN THE
HIGHER ELEVATIONS MAY AFFECT NORTHERN AND WESTERN AREAS LATE IN
THE DAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
A TROF WILL CROSS THE REGION THURSDAY NIGHT...WITH ANOTHER TROF
CROSSING THE REGION FRIDAY. MOSTLY CLOUDY SKIES ALONG WITH A
SLIGHT CHANCE OF RAIN/SNOW SHOWERS ARE EXPECTED ACROSS THE NORTH
AND MOUNTAINS THURSDAY NIGHT AND FRIDAY...WITH GENERALLY PARTLY
CLOUDY SKIES DOWNEAST. HIGH PRESSURE WILL THEN BUILD EAST FRIDAY
NIGHT WITH PARTLY CLOUDY SKIES NORTH AND PARTLY CLOUDY/MOSTLY
CLEAR SKIES DOWNEAST. TEMPERATURES WILL BE AT NEAR NORMAL...TO
SLIGHTLY BELOW NORMAL...LEVELS THURSDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL CROSS THE REGION SATURDAY WHILE LOW PRESSURE
TRACKING NORTHEAST FROM THE GREAT LAKES DRAWS A COLD/OCCLUDED
FRONT TOWARD THE REGION. CLOUD COVER WILL INCREASE ACROSS THE
REGION LATER SATURDAY IN ADVANCE OF THE COLD/OCCLUDED FRONT. THE
COLD/OCCLUDED FRONT WILL THEN CROSS THE REGION SATURDAY NIGHT
THROUGH SUNDAY. FORECAST SOUNDINGS INDICATE THAT TEMPERATURES
ALOFT WOULD SUPPORT SNOW ACROSS MUCH OF THE FORECAST AREA SATURDAY
NIGHT. HOWEVER...BOUNDARY LAYER TEMPERATURES WILL REMAIN MARGINAL
FOR SNOW ACROSS MOSTLY NORTHERN/CENTRAL PORTIONS OF THE FORECAST
AREA. EXPECT A RAIN/SNOW MIX COULD TRANSITION TO MOSTLY SNOW
ACROSS NORTHERN PORTIONS OF THE FORECAST AREA SATURDAY
NIGHT...WITH A RAIN/SNOW MIX ACROSS CENTRAL AREAS AND MOSTLY RAIN
DOWNEAST. COULD HAVE LIGHT SNOW ACCUMULATIONS ACROSS NORTHERN
AREAS LATER SATURDAY NIGHT PARTICULARLY ACROSS HIGHER TERRAIN
AREAS. THE COLD/OCCLUDED FRONT WILL MOVE EAST EARLY SUNDAY WITH
STEADIER PRECIPITATION ENDING. COULD THEN HAVE LINGERING RAIN
SHOWERS ACROSS MOSTLY NORTHERN AREAS SUNDAY AFTERNOON...WITH A
SLIGHT CHANCE OF RAIN/SNOW SHOWERS SUNDAY NIGHT. A COLD FRONT THEN
CROSSES THE REGION MONDAY WITH A CHANCE OF RAIN/SNOW SHOWERS
ACROSS MOSTLY THE NORTH/MOUNTAINS. HIGH PRESSURE WILL THEN CROSS
THE REGION TUESDAY. UNCERTAINTY EXISTS TUESDAY NIGHT INTO
WEDNESDAY REGARDING WHETHER A POSSIBLE COLD FRONT CROSSES THE
REGION WITH A CHANCE OF SHOWERS OR WHETHER HIGH PRESSURE PERSISTS.
TEMPERATURES WILL REMAIN AT NEAR NORMAL...TO SLIGHTLY BELOW
NORMAL...LEVELS SATURDAY THROUGH WEDNESDAY.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE AREA TONIGHT AND
THURSDAY. THERE IS THE POTENTIAL THAT THERE COULD BE A SHORT
WINDOW OF MVFR CEILINGS AT KBHB OVERNIGHT IF THE AREA OF RAIN
OFFSHORE MOVES INTO THE AREA...BUT ODDS FAVOR CONDITIONS REMAINING
VFR. THE WIND WILL BECOME GUSTY THURSDAY AS COOLER AIR MOVES IN.
SHORT TERM: OCCASIONAL MVFR CONDITIONS ARE POSSIBLE ACROSS MOSTLY
THE NORTH AND MOUNTAINS THURSDAY NIGHT INTO FRIDAY...WITH VFR
CONDITIONS DOWNEAST. VFR CONDITIONS ARE EXPECTED ACROSS THE REGION
FRIDAY NIGHT INTO SATURDAY. MVFR/IFR CONDITIONS ARE THEN EXPECTED
ACROSS THE REGION SATURDAY NIGHT INTO EARLY SUNDAY. OCCASIONAL
MVFR CONDITIONS WILL LINGER ACROSS THE NORTH AND MOUNTAINS SUNDAY
NIGHT INTO MONDAY...WITH GENERALLY VFR CONDITIONS DOWNEAST.
&&
.MARINE...
NEAR TERM: A GALE WARNING IS IN EFFECT FOR THE OFFSHORE WATERS
FOR WEST WINDS GUSTING UP TO 35 KT THURSDAY AFTERNOON INTO
THURSDAY EVENING. A SCA IS IN EFFECT FOR THE INTRACOASTAL WATERS
THURSDAY AFTERNOON AND EVENING.
SHORT TERM: A GALE WARNING WILL REMAIN IN EFFECT FOR MUCH OF THE
WATERS EARLY THURSDAY NIGHT. GENERALLY SMALL CRAFT CONDITIONS ARE
THEN EXPECTED ACROSS THE WATERS LATER THURSDAY NIGHT INTO MONDAY.
VISIBILITIES COULD BE REDUCED IN RAIN SATURDAY NIGHT INTO SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON THURSDAY TO MIDNIGHT EDT
THURSDAY NIGHT FOR ANZ052.
GALE WARNING FROM NOON THURSDAY TO MIDNIGHT EDT THURSDAY NIGHT
FOR ANZ050-051.
&&
$$
NEAR TERM...BLOOMER/CB
SHORT TERM...NORCROSS
LONG TERM...NORCROSS
AVIATION...BLOOMER/CB/NORCROSS
MARINE...BLOOMER/CB/NORCROSS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
610 PM EDT TUE OCT 22 2013
.SYNOPSIS...
A COLD FRONT WILL PUSH EAST OF THE AREA TONIGHT THEN A SMALL AREA
OF LOW PRESSURE WILL SLIDE SOUTH OF THE REGION ON WEDNESDAY. A
LARGE TROUGH OF LOW PRESSURE WILL BUILD INTO THE EAST THURSDAY
INTO FRIDAY AS CHILLY AIR PUSHES DOWN FROM CANADA.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
610 PM UPDATE...LOW PRES JUST EAST OF JAMES BAY WILL REMAIN
QUASI-STATIONARY TONIGHT AND CONTINUE TO DEEPEN TO AROUND 985 MB
BY 12Z WED. A PRE-FRONTAL TROUGH STRETCHES FROM ERN AROOSTOOK
COUNTY TO NEAR BANGOR AT 22Z. THERE IS A LINE OF SHOWERS
ASSOCIATED WITH THIS TROUGH. THERE IS A SECOND LINE OF SHOWERS
WHICH ARE ASSOCIATED WITH A STRONG COLD THAT EXTENDS FROM AROUND
FT KENT TO GREENVILLE. THIS FRONT WILL SWEEP ACROSS THE REMAINDER
OF THE CWA THIS EVENING LIKELY MERGING WITH THE PRE-FRONTAL
TROUGH. THE LAST OF THE SHOWERS SHOULD EXIT SOUTHEAST WASHINGTON
COUNTY BY AROUND MIDNIGHT. IN THE WAKE OF THE FRONT A MUCH COLDER
AIR MASS WILL SPREAD ACROSS THE REGION OVERNIGHT. MADE SOME TWEAKS
TO POP/WX GRIDS BASED ON THE LATEST RADAR RETURNS. ALSO REMOVED
THE MENTION OF THUNDER FOR THIS EVENING AS THERE HAVE NOT BEEN ANY
CLOUD TO GROUND STRIKES NOR ANY IN CLOUD LIGHTNING.
PREVIOUS DISCUSSION...
AREA OF SHOWERS SETTING UP AHEAD OF THE APCHG COLD
FRONT PER THE 18Z RADAR TREND. 18Z SFC ANALYSIS SHOWS A PRE-
FRONTAL TROF OUR AHEAD OF THE COLD FRONT W/THE SHOWERS ALIGNED
W/THE BOUNDARY. THE LATEST HRRR WAS DOING QUITE WELL W/THE
PLACEMENT AND MOVEMENT OF THE PRECIP SHIELD. LAPS SOUNDINGS SHOWED
SOME DESTABILIZATION MAINLY ACROSS THE CENTRAL HIGHLANDS AND
INTERIOR DOWNEAST WHERE SOME HEATING AND THE BEST 0-6KM SHEAR
EXISTS. CONTINUED TO CARRY ISOLD TSTMS IN THESE AREAS THROUGH 00Z.
OTRW, SHOWERS AND GUSTY WINDS OF UP TO 35 MPH AREA POSSIBLE.
LATEST RADAR VELOCITY DID SHOW 40 KTS AT 6K FT ACROSS THE CENTRAL
HIGHLANDS AT 18Z. TEMPERATURES ARE PEAKED AND NOW WILL BEGIN TO
FALL BACK AFTER 00Z WHEN THE COLD FRONT ARRIVES. SHOWERS WILL BE
INTO NEW BRUNSWICK BY 02Z OR SO AND THEN PARTIAL CLEARING WILL
BEGIN LATER THIS EVENING INTO THE OVERNIGHT HOURS. CAA WILL BRING
BREEZY CONDITIONS FOR A WHILE UP THROUGH 06Z AND THEN WINDS WILL
DROP OFF AS THE GRADIENT LOOSENS. COLD AIR TO ARRIVE BY WEDNESDAY
MORNING W/READINGS BY 7 AM IN THE UPPER 20S TO AROUND 30 ACROSS
THE NORTH AND WEST AND LOW/MID 30S INTERIOR DOWNEAST AND THE
COAST. COLLABORATED W/NERFC AND LOWERED QPF AMOUNTS TO 0.15-0.30
ACROSS THE NORTHERN 1/2 OF THE CWA W/0.10 OR LESS FOR THE CENTRAL
HIGHLANDS AND INTERIOR DOWNEAST.
A CHILLY DAY ON WEDNESDAY W/SOME BRIEF RIDGING AND SUNSHINE. IT
WILL FEEL SOMEWHAT LIKE A SHOCK TO THE SYSTEM AS DAYTIME HIGHS ARE
EXPECTED TO BE IN THE UPPER 40S TO AROUND 50 NORTH AND WEST TO
LOWER 50S DOWNEAST. DECIDED ON THE ECMWFMOS/GMOS BLEND FOR
TEMPERATURES.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
A DEEP TROUGH MOVING INTO THE EAST WILL USHER IN SOME VERY CHILLY
AIR FOR THE LATTER PART OF THIS WEEK. A SMALL WAVE OF LOW PRESSURE
TRACKING OFF THE MID ATLANTIC COAST AND SLIDING WELL SOUTH OF THE
REGION MAY BRING SOME LIGHT RAIN TO DOWNEAST LOCATIONS EARLY
WEDNESDAY EVENING. OTHERWISE, WEDNESDAY NIGHT WILL BE PARTLY CLOUDY
AND BECOMING BREEZY AS THE GRADIENT SOUTH OF A LARGE LOW PRESSURE
SYSTEM MOVING INTO EASTERN CANADA BEGINS TO EFFECT THE REGION. THIS
WILL GIVE WAY TO A WINDY AND CHILLY DAY ON THURSDAY AS COLD AIR
PULLING AROUND THE LOW FLOWS INTO THE STATE. SKIES WILL RANGE FROM
PARTLY CLOUDY DOWNEAST TO OVERCAST IN STRATOCUMULUS CLOUDS ACROSS
THE NORTH AND SOME LIGHT RAIN, OR POSSIBLY SNOW SHOWERS, MAY AFFECT
NORTHERN AREAS ESPECIALLY OVER HIGHER ELEVATIONS. BREEZY AND CHILLY
CONDITIONS WITH A MOSTLY CLOUDY SKY NORTH AND PARTIAL CLOUDINESS
DOWNEAST WILL CONTINUE THURSDAY NIGHT INTO FRIDAY. SOME PATCHY LIGHT
SHOWERS OR FLURRIES ARE POSSIBLE IN THE HIGHER ELEVATIONS IN THE
WEST THURSDAY NIGHT OR FRIDAY. OTHERWISE, MAINLY DRY WEATHER WILL
CONTINUE OVER THE AREA INTO FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SHORTWAVE CASCADING INTO THE TROUGH FRIDAY NIGHT WILL DEVELOP LOW
PRESSURE IN THE GREAT LAKES ON SATURDAY. CHILLY AIR WILL BE IN PLACE
SATURDAY INTO SATURDAY EVENING AS THIS LOW APPROACHES WITH
INCREASING CLOUDS. PRECIPITATION WILL SPREAD ACROSS THE REGION
SATURDAY EVENING. CURRENT GUIDANCE INCLUDING THE GFS AND ECMWF ARE
INDICATING THE AIR WILL LIKELY BE COLD ENOUGH TO SUPPORT SOME WET
SNOW ACROSS THE NORTH AS THE PRECIPITATION MOVES IN SATURDAY EVENING.
THE ECMWF HAS LOW LEVEL CRITICAL THICKNESSES BELOW 1300 AT 1000-850
MB, COLD ENOUGH TO SUPPORT SNOW, ACROSS THE NORTHERN HALF OT THE
STATE SATURDAY EVENING. THE GFS HAS THE NORTHERN THIRD OF THE STATE
COLD ENOUGH FOR SNOW. ALL OF THE GFS ENSEMBLE MEMBERS SUPPORT
THICKNESSES COLD ENOUGH FOR SNOW OVER THE NORTH. THE CANADIAN MODEL,
HOWEVER, INDICATES THICKNESSES WILL BE TOO WARM FOR SNOW. THE AIR IS
EXPECTED TO WARM A BIT LATE SATURDAY NIGHT INTO SUNDAY MORNING AS
THE LOW CENTER TRACKS ACROSS THE NORTHERN PART OF THE STATE SO ANY
SNOW WOULD LIKELY TURN OVER TO RAIN. AN INCH OR TWO OF SNOW MAY FALL
ACROSS THE NORTHERN PART OF THE STATE BEFORE THE CHANGE OVER WITH
THE GREATEST CHANCES FOR SOME ACCUMULATION OVER ELEVATIONS ABOVE 700
FT. PRECIPITATION WILL END SUNDAY MORNING. ANOTHER SURGE OF CHILLY
AIR WILL FOLLOW THE SYSTEM EARLY NEXT WEEK AS HIGH PRESSURE BUILDS
IN FROM CANADA.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
NEAR TERM: A BRIEF PERIOD OF MVFR THIS EVENING W/THE COLD FROPA
AND THEN VFR RIGHT INTO WEDNESDAY.
SHORT TERM: CONDITIONS ARE EXPECTED TO IMPROVE TO VFR WEDNESDAY
NIGHT THEN BE VFR ON THURSDAY. CONDITIONS MAY LOWER TO MVFR IN
STRATOCUMULUS CLOUDS ACROSS THE NORTH LATE THURSDAY INTO THURSDAY
NIGHT AND REMAIN VFR DOWNEAST. VFR CONDITIONS ARE EXPECTED FRIDAY
INTO SATURDAY. CONDITIONS WILL THEN LOWER TO IFR IN PRECIPITATION
SATURDAY NIGHT.
&&
.MARINE...
NEAR TERM: SEAS HAVE CONTINUED TO BUILD THIS AFTERNOON AND ARE NOW
RUNNING AROUND 5 FT AT THE EASTERN MAINE SHELF AS OF 5 PM EDT. THE
SCA TO STAY UP THROUGH MIDNIGHT. EXPECTING GUSTS TO 25KT THROUGH
MIDNIGHT AND THEN GRADIENT IS EXPECTED TO WEAKEN AS THE COLD FRONT
PASSES THROUGH THE WATERS. SW WINDS EXPECTED TO SHIFT TO THE WNW
LATER TONIGHT INTO WEDNESDAY. WINDS WILL DROP OFF TO 10 KT BY 12Z
WEDNESDAY W/SEAS DROPPING OFF TO LESS THAN 3 FT.
SHORT TERM: A STRONG SCA OR POSSIBLY A GALE WILL BE NEEDED FOR
GUSTY WEST WINDS ON THURSDAY. AN SCA WILL LIKELY BE NEEDED
THURSDAY NIGHT. WINDS SHOULD THEN BE BELOW SCA FRIDAY AND
SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ050>052.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...BLOOMER
LONG TERM...BLOOMER
AVIATION...CB/HEWITT/BLOOMER
MARINE...CB/HEWITT/BLOOMER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
336 PM EDT TUE OCT 22 2013
.SYNOPSIS...
A COLD FRONT WILL PUSH EAST OF THE AREA TONIGHT THEN A SMALL AREA
OF LOW PRESSURE WILL SLIDE SOUTH OF THE REGION ON WEDNESDAY. A
LARGE TROUGH OF LOW PRESSURE WILL BUILD INTO THE EAST THURSDAY
INTO FRIDAY AS CHILLY AIR PUSHES DOWN FROM CANADA.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AREA OF SHOWERS SETTING UP AHEAD OF THE APCHG COLD FRONT PER THE
18Z RADAR TREND. 18Z SFC ANALYSIS SHOWS A PRE-FRONTAL TROF OUR
AHEAD OF THE COLD FRONT W/THE SHOWERS ALIGNED W/THE BOUNDARY. THE
LATEST HRRR WAS DOING QUITE WELL W/THE PLACEMENT AND MOVEMENT OF
THE PRECIP SHIELD. LAPS SOUNDINGS SHOWED SOME DESTABILIZATION
MAINLY ACROSS THE CENTRAL HIGHLANDS AND INTERIOR DOWNEAST WHERE
SOME HEATING AND THE BEST 0-6KM SHEAR EXISTS. CONTINUED TO CARRY
ISOLD TSTMS IN THESE AREAS THROUGH 00Z. OTRW, SHOWERS AND GUSTY
WINDS OF UP TO 35 MPH AREA POSSIBLE. LATEST RADAR VELOCITY DID
SHOW 40 KTS AT 6K FT ACROSS THE CENTRAL HIGHLANDS AT 18Z. TEMPERATURES
ARE PEAKED AND NOW WILL BEGIN TO FALL BACK AFTER 00Z WHEN THE COLD
FRONT ARRIVES. SHOWERS WILL BE INTO NEW BRUNSWICK BY 02Z OR SO AND
THEN PARTIAL CLEARING WILL BEGIN LATER THIS EVENING INTO THE OVERNIGHT
HOURS. CAA WILL BRING BREEZY CONDITIONS FOR A WHILE UP THROUGH 06Z
AND THEN WINDS WILL DROP OFF AS THE GRADIENT LOOSENS. COLD AIR TO
ARRIVE BY WEDNESDAY MORNING W/READINGS BY 7 AM IN THE UPPER 20S TO
AROUND 30 ACROSS THE NORTH AND WEST AND LOW/MID 30S INTERIOR
DOWNEAST AND THE COAST. COLLABORATED W/NERFC AND LOWERED QPF
AMOUNTS TO 0.15-0.30 ACROSS THE NORTHERN 1/2 OF THE CWA W/0.10 OR
LESS FOR THE CENTRAL HIGHLANDS AND INTERIOR DOWNEAST.
A CHILLY DAY ON WEDNESDAY W/SOME BRIEF RIDGING AND SUNSHINE. IT
WILL FEEL SOMEWHAT LIKE A SHOCK TO THE SYSTEM AS DAYTIME HIGHS ARE
EXPECTED TO BE IN THE UPPER 40S TO AROUND 50 NORTH AND WEST TO
LOWER 50S DOWNEAST. DECIDED ON THE ECMWFMOS/GMOS BLEND FOR
TEMPERATURES.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
A DEEP TROUGH MOVING INTO THE EAST WILL USHER IN SOME VERY CHILLY
AIR FOR THE LATTER PART OF THIS WEEK. A SMALL WAVE OF LOW PRESSURE
TRACKING OFF THE MID ATLANTIC COAST AND SLIDING WELL SOUTH OF THE
REGION MAY BRING SOME LIGHT RAIN TO DOWNEAST LOCATIONS EARLY
WEDNESDAY EVENING. OTHERWISE, WEDNESDAY NIGHT WILL BE PARTLY CLOUDY
AND BECOMING BREEZY AS THE GRADIENT SOUTH OF A LARGE LOW PRESSURE
SYSTEM MOVING INTO EASTERN CANADA BEGINS TO EFFECT THE REGION. THIS
WILL GIVE WAY TO A WINDY AND CHILLY DAY ON THURSDAY AS COLD AIR
PULLING AROUND THE LOW FLOWS INTO THE STATE. SKIES WILL RANGE FROM
PARTLY CLOUDY DOWNEAST TO OVERCAST IN STRATOCUMULUS CLOUDS ACROSS
THE NORTH AND SOME LIGHT RAIN, OR POSSIBLY SNOW SHOWERS, MAY AFFECT
NORTHERN AREAS ESPECIALLY OVER HIGHER ELEVATIONS. BREEZY AND CHILLY
CONDITIONS WITH A MOSTLY CLOUDY SKY NORTH AND PARTIAL CLOUDINESS
DOWNEAST WILL CONTINUE THURSDAY NIGHT INTO FRIDAY. SOME PATCHY LIGHT
SHOWERS OR FLURRIES ARE POSSIBLE IN THE HIGHER ELEVATIONS IN THE
WEST THURSDAY NIGHT OR FRIDAY. OTHERWISE, MAINLY DRY WEATHER WILL
CONTINUE OVER THE AREA INTO FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SHORTWAVE CASCADING INTO THE TROUGH FRIDAY NIGHT WILL DEVELOP LOW
PRESSURE IN THE GREAT LAKES ON SATURDAY. CHILLY AIR WILL BE IN PLACE
SATURDAY INTO SATURDAY EVENING AS THIS LOW APPROACHES WITH
INCREASING CLOUDS. PRECIPITATION WILL SPREAD ACROSS THE REGION
SATURDAY EVENING. CURRENT GUIDANCE INCLUDING THE GFS AND ECMWF ARE
INDICATING THE AIR WILL LIKELY BE COLD ENOUGH TO SUPPORT SOME WET
SNOW ACROSS THE NORTH AS THE PRICIPIATION MOVES IN SATURDAY EVENING.
THE ECMWF HAS LOW LEVEL CRITICAL THICKNESSES BELOW 1300 AT 1000-850
MB, COLD ENOUGH TO SUPPORT SNOW, ACROSS THE NORTHERN HALF OT THE
STATE SATURDAY EVENING. THE GFS HAS THE NORTHERN THIRD OF THE STATE
COLD ENOUGH FOR SNOW. ALL OF THE GFS ENSEMBLE MEMBERS SUPPORT
THICKNESSES COLD ENOUGH FOR SNOW OVER THE NORTH. THE CANADIAN MODEL,
HOWEVER, INDICATES THICKNESSES WILL BE TOO WARM FOR SNOW. THE AIR IS
EXPECTED TO WARM A BIT LATE SATURDAY NIGHT INTO SUNDAY MORNING AS
THE LOW CENTER TRACKS ACROSS THE NORTHERN PART OF THE STATE SO ANY
SNOW WOULD LIKELY TURN OVER TO RAIN. AN INCH OR TWO OF SNOW MAY FALL
ACROSS THE NORTHERN PART OF THE STATE BEFORE THE CHANGE OVER WITH
THE GREATEST CHANCES FOR SOME ACCUMULATION OVER ELEVATIONS ABOVE 700
FT. PRECIPITATION WILL END SUNDAY MORNING. ANOTHER SURGE OF CHILLY
AIR WILL FOLLOW THE SYSTEM EARLY NEXT WEEK AS HIGH PRESSURE BUILDS
IN FROM CANADA.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
NEAR TERM: A BRIEF PERIOD OF MVFR THIS EVENING W/THE COLD FROPA
AND THEN VFR RIGHT INTO WEDNESDAY.
SHORT TERM: CONDITIONS ARE EXPECTED TO IMPROVE TO VFR WEDNESDAY
NIGHT THEN BE VFR ON THURSDAY. CONDITIONS MAY LOWER TO MVFR IN
STRATOCUMULUS CLOUDS ACROSS THE NORTH LATE THURSDAY INTO THURSDAY
NIGHT AND REMAIN VFR DOWNEAST. VFR CONDITIONS ARE EXPECTED FRIDAY
INTO SATURDAY. CONDITIONS WILL THEN LOWER TO IFR IN PRECIPITATION
SATURDAY NIGHT.
&&
.MARINE...
NEAR TERM: SCA TO STAY UP THROUGH MIDNIGHT. GUSTS ARE UP TO 20KT
ATTM W/SEAS NOW UP TO 4 FT AS OF 18Z OBS. EXPECTING GUSTS TO 25KT
THROUGH MIDNIGHT AND THEN GRADIENT IS EXPECTED TO WEAKEN AS THE
COLD FRONT PASSES THROUGH THE WATERS. SW WINDS EXPECTED TO SHIFT
TO THE WNW LATER TONIGHT INTO WEDNESDAY. WINDS WILL DROP OFF TO 10
KT BY 12Z WEDNESDAY W/SEAS DROPPING OFF TO LESS THAN 3 FT.
SHORT TERM: A STRONG SCA OR POSSIBLY A GALE WILL BE NEEDED FOR
GUSTY WEST WINDS ON THURSDAY. AN SCA WILL LIKELY BE NEEDED
THURSDAY NIGHT. WINDS SHOULD THEN BE BELOW SCA FRIDAY AND
SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...BLOOMER
LONG TERM...BLOOMER
AVIATION...HEWITT/BLOOMER
MARINE...HEWITT/BLOOMER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
126 PM EDT TUE OCT 22 2013
.SYNOPSIS...
A COLD FRONT IS THEN EXPECTED TO MOVE ACROSS THE REGION THIS
EVENING. ANOTHER WEAK LOW PRES WILL MOVE EAST...NORTHEAST FROM THE
MID ATLANTIC STATES TO SOUTH OF NOVA SCOTIA ON WEDNESDAY.&&
.NEAR TERM /THROUGH TONIGHT/...
125 PM UPDATE...ADJUSTED THE PRECIP CHANCES TO ALIGN W/THE LATEST
RADAR TRENDS SHOWING 2 AREAS OF SHOWERS W/ONE AREA MOVING ACROSS
WASHINGTON COUNTY AND THE OTHER AREA(MORE OF A LINE) MOVING INTO
NORTHERN AND CENTRAL MAINE AHEAD OF THE COLD FRONT. THIS AREA
APPEARS TO BE ALIGNED W/A PRE-FRONTAL TROF AS INDICATED BY THE 16Z
SFC ANALYSIS. VELOCITY FIELDS INDICATE GUSTS TO 40 KTS AT 5KT FT.
THEREFORE, INCREASED WIND GUSTS THIS AFTERNOON TO 30 MPH AND MOVED
THREAT OF THUNDER S OF A CARIBOU TO BAXTER STATE LINE. THIS BASED
ON LATEST LAPS SOUNDINGS SHOWING ANY INSTABILITY S OF THE LINE.
PREVIOUS DISCUSSION... SOUTH FLOW WILL INCREASE AHEAD OF THE
APPROACHING FRONT, USHERING IN MOISTURE AND RELATIVELY MILD AIR.
THE GFS AND NAM INDICATE LAPSE RATES AROUND 6.5C/KM AND 0-6KM
SHEAR RUNNING AROUND 40 KT, BOTH OF WHICH WOULD HELP CONVECTION
SET UP. ALSO NOTE THAT THE LATEST HRRR HINTS AT A LINE OF HIGHER
REFLECTIVITY COINCIDENT WITH THE FRONT THIS AFTERNOON. HAVE
THEREFORE LEFT ISOLATED THUNDER IN THE FORECAST FOR THIS AFTERNOON
FOR MUCH OF THE FORECAST AREA, THOUGH DOWNEAST AREAS HAVE THE BEST
CHANCES OF ACTUALLY SEEING ANY THUNDERSTORMS. GIVEN THE
AFOREMENTIONED SHEAR, GUSTY WINDS WILL BE POSSIBLE IN ANY OF THE
STRONGER ACTIVITY, REGARDLESS OF WHETHER OR NOT THERE IS THUNDER.
OVERALL, EXPECT ABOUT A THIRD OF AN INCH OF RAIN AT MOST, WITH
MUCH OF THE AREA SEEING LESS THAN A QUARTER OF AN INCH BY TONIGHT.
FOR TONIGHT...THE FRONT WILL EXIT INTO NEW BRUNSWICK THIS EVENING,
WITH THE RAIN COMING TO A QUICK END THEREAFTER. MUCH COOLER AND
DRIER AIR WILL FOLLOW IN THE FRONT`S FOOTSTEPS, LEADING TO CLEARING
SKIES AND COOLING TEMPERATURES. OVERNIGHT LOWS WILL BE IN THE LOWER
30S NORTH, WITH THE USUAL COLD SPOTS ACROSS THE NORTHWEST DROPPING
INTO THE 20S. CENTRAL AND SOUTHERN AREAS WILL SEE MID 30S, WITH THE
COAST BOTTOMING OUT AROUND 40.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
MODELS CONT TO AGREE ON A WEAK LOW PRES SYSTEM WITH AN ALBERTA
CLIPPER LIKE S/WV FROM THE OH VLY MOVG ENE FROM THE MID ATLC
STATES WED TO S OF NOVA SCOTIA WED NGT. THIS SYSTEM WILL BRING
CLDNSS TO THE CNTRL AND DOWNEAST PTNS OF THE FA WED INTO WED EVE
ALG WITH THE POSSIBILITY OF LGT RNFL TO DOWNEAST TO PERHAPS AS FAR
N AS E CNTRL PTNS OF THE FA BY ERLY WED EVE. IN ANY EVENT... THE
BEST POTENTIAL OF RNFL WITH THIS SYS APPEARS TO BE FAR SE ME...
BUT EVEN HERE...6 HRLY QPF AMOUNTS LOOK TO BE LGT...AND THERE MAY
BE EVEN A SHARPER SE TO NW CUT-OFF OF PRECIP THEN WHAT WE INDICATE
WITH THE GFS (ONE OF THE MODELS IN THE BLEND WE USED) LIKELY TO
GENEROUS WITH QPF NWRD INTO ME WHERE LLVL DRY AIR MAY RESULT IN
SIG EVAPORATION. IN ANY EVENT...PRECIP FROM THIS LOW SHOULD EXIT
THE FA LATE WED NGT.
IN THE WAKE OF THIS LOW...MDT TO STRONG LLVL COLD ADVCN WILL BEGIN
ACROSS THE FA ERLY THU AND CONT INTO THU EVE. IN ADDITION...AN UPPER
LVL TROF WILL BRING SC TO SPCLY WRN AND NRN PTNS OF THE FA WITH
THE POSSIBILITY OF RN AND HIER TRRN SN SHWRS. AFT THE PASSAGE OF
THE UPPER TROF LATE THU NGT...WINDS SHOULD SUBSIDE SOMEWHAT AND
SHWRS SHOULD MSLY DISSIPATE TO SCT FLURRIES. BOTH DAY AND NGT TM
TEMPS WILL BE ON THE DECLINE EACH PD OF THE SHORT TERM AS
PROGRESSIVELY COLDER AIR CROSSES INTO THE FA FROM QB PROV.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
OVERALL CONTD CHILLY AND UNSETTLED OVR THE FA THRU THE LONG TERM
WITH SIG BLO NORMAL TEMPS.
FRI CONTS TO LOOK BREEZY AND CHILLY...BUT NOT AS BRISK AS THU.
CANNOT RULE OUT SCT FLURRIES OR SPRINKLES OVR THE W AND N...
BUT EVEN HERE THERE SHOULD BE PARTIAL CLRG FRI NGT AS A WEAK
SFC RIDGE BRIDGES INTO THE FA FROM THE OH VLY. SAT WILL BEGIN
BUT HI AND MID CLDNSS WILL INCREASE FROM THE W LATER IN THE DAY
ANOTHER ALBERTA CLIPPER S/WV MOVES TOWARD THE FA FROM THE GREAT
LKS.
DESPITE THE INITIAL SRLY LLVL WINDS THAT SETS UP WITH THE ONSET
OF PRECIP SAT NGT WITH THIS S/WV...THE COMBO OF EVAPORATIONAL AND
WEAK DYNAMIC COOLING FROM PRECIP FALLING FROM MID CLD LVL MAY
RESULT IN A CHG OVR OF LGT RN TO LGT WET SN LATE SAT NGT/ERLY SUN
MORN OVR NRN PTNS OF THE FA...SPCLY IF THE COLDER 00Z ECMWF
SOLUTION VERIFIES...WHICH IMPLIES A WEAK SECONDARY SPOT LOW ON THE
OCCLUSION PT BY ERLY SUN AFTN. FOR THIS REASON WE INTRODUCE A
CHC OF SN WITH THIS SYSTEM ACROSS THE N AND A MIX OF LGT RN/SN
OVR E CNTRL AND INTERIOR DOWNEAST PTNS OF THE FA LATE SAT NGT/ERLY
SUN MORN... WITH COASTAL DOWNEAST AREAS REMAINING LGT RN DUE TO
THE BL INFLUENCE OF MILD MARINE AIR ADVCTG OVR THIS AREA ON S
WINDS. ATTM...QPF LOOKS TO BE FAIRLY LGT...BUT CANNOT RULE OUT AN
INCH OR TWO OF WET SNFL OVR THE HIER TRRN OF THE NW...WITH LESSER
AMOUNTS S AND E.
ANY STEADY PRECIP SUN MORN SHOULD QUICKLY EXIT E OF THE FA BY
MIDDAY SUN AS THE S/WV TRACKS E OF THE FA...LEAVING MSLY SCT AFTN
RN SHWRS...POSSIBLY STILL MIXED WITH WET SN OVR VERY HIGH TRRN.
FAIR CONDITIONS WITH CLRG OVR THE SRN TWO THIRDS OF THE FA CAN BE
XPCTD SUN NGT WITH CONTD CHILLY CONDITIONS ON MON.
&&
.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: CONDITIONS WILL GENERALLY BE VFR THROUGH THIS MORNING,
THOUGH MVFR CEILINGS WILL BE LIKELY AT KFVE. SHOWERS WILL BE WINDING
DOWN FOR A BIT THIS MORNING, BUT THEY WILL RETURN THIS AFTERNOON
AS A COLD FRONT MOVES FROM WEST TO EAST. MVFR CEILINGS WILL
PREVAIL (IFR AT KFVE) AT THE NORTHERN TERMINALS, BUT KBGR AND KBHB
SHOULD REMAIN VFR THROUGH THE PERIOD. THE RAIN WILL END SHORTLY
AFTER 00Z, SO EXPECT CLOUDS TO LIFT TO VFR AT ALL SITES BY 06Z.
SHORT TO LONG TERM: VFR XPCTD WED INTO WED EVE FOR NRN TAF SITES
WITH MVFR POSSIBLE FOR DOWNEAST SITES DUE TO LOW CLGS AND
INTERMITTENT LGT RNFL WITH A DISTANT OFFSHORE ATLC LOW PRES SYSTEM.
VFR CONDITIONS SHOULD RETURN FOR DOWNEAST SITES WHILE NRN TAF SITES
BECOME MVFR VERY LATE WED NGT IN BKN-OVC SC AND ANY RN/SN SHWRS
WITH LLVL COLD ADVCN AND THE APCH OF AN UPPER TROF...AND THIS
TREND SHOULD CONT THRU THU NGT...AFT WHICH ALL SITES SHOULD BE VFR
FRI AFT THE PASSAGE OF THE UPPER TROF AND CONT SO THRU SAT.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM NOON
TODAY TO MIDNIGHT TONIGHT. SOUTH WINDS WILL INCREASE THROUGH THE
MORNING HOURS AHEAD OF AN APPROACHING COLD FRONT, BECOMING 15 TO
20 KT WITH GUSTS TO AROUND 25 KT BY LATE AFTERNOON. THIS WILL
ALLOW SEAS TO BUILD TO AROUND 5 FT. CONDITIONS WILL IMPROVE LATE
TONIGHT BEHIND THE FRONT.
SHORT TO LONG TERM: WE STILL XPCT MDT TO STRONG SCA CONDITIONS OVR
OUR WATERS THU INTO THU NGT WITH STRONG LLVL COLD ADVCN BEHIND A
DEVELOPING LOW PRES SYS OVR THE ERN MARITIMES. WINDS AND WVS WILL
DIMINISH BLO SCA CRITERIA ON FRI AS THE LOW MOVES INTO THE OPEN
ATLC...WITH BLO SCA CONDITIONS XPCTD TO LAST THRU SAT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS GAYLORD MI
711 PM EDT WED OCT 23 2013
.SYNOPSIS...
ISSUED AT 408 PM EDT WED OCT 23 2013
THE DEEP UPPER TROUGH AND ASSOCIATED COLD AIR WHICH MOVED OVER ONTARIO
EARLIER THIS WEEK...WILL REMAIN NEARLY STATIONARY ACROSS THE GREAT
LAKES THROUGH THE WEEKEND. THE UPPER TROUGH WILL COMBINE WITH A
SERIES OF WEAKER STORM SYSTEMS FORECAST TO SWEEP OVER THE GREAT
LAKES...TO GENERATE A WINTRY RAIN SNOW MIX OVER NORTHERN MICHIGAN
THROUGH THE WEEKEND. TEMPERATURES WILL REMAIN NEARLY SEASONAL TO
SLIGHTLY BELOW NORMAL INTO THE BEGINNING OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 647 PM EDT WED OCT 23 2013
POCKETS OF INTENSE LAKE EFFECT SNOW SHOWERS CONTINUE TO IMPACT
PORTIONS OF NORTHWEST LOWER MICHIGAN. ONE MID LEVEL SHORTWAVE
MOVING THROUGH THIS EVENING WITH ANOTHER MORE IMPRESSIVE WAVE
UPSTREAM TO ROTATE THROUGH THE AREA THURSDAY MORNING. ALSO SEEING
DEEPER MOISTURE ROTATING SOUTHWARD OUT OF CANADA AND TOWARD THE
AREA. VISIBILITIES DROPPING TO LESS THAN 1 MILE AT TIMES IN SOME
OF THE MORE INTENSE SNOW BANDS. LOW LEVEL FLOW WILL GRADUALLY
COME AROUND MORE NORTHWEST LATER TONIGHT WITH ENHANCED LOW LEVEL
CONVERGENCE ALONG THIS WIND SHIFT LIKELY FURTHER ENHANCING ACTIVITY
FOR A TIME. WE MAY SEE THE ACTIVITY DIMINISH FOR A TIME TONIGHT
BEFORE RAMPING UP AGAIN TOWARD THURSDAY MORNING WITH THE ARRIVAL
OF NEXT UPPER LEVEL WAVE/MOISTURE. HIGHER TERRAIN WILL LIKELY SEE
2-3 INCHES OF SNOW OVERNIGHT WITH A FEW HIGHER AMOUNTS POSSIBLE.
SINCE THIS IS THE FIRST BOUT OF WINTER WEATHER THAT MANY AREAS
HAVE SEEN AND EXPECTED SLICK SPOTS OF ROADS/AREAS OF REDUCED
VISIBILITIES...HAVE HOISTED AN ADVISORY FOR PORTIONS OF NORTHWEST LOWER
MICHIGAN THROUGH THURSDAY MORNING.
BANDS OF RAIN/SNOW SHOWER ACTIVITY ALSO ROTATING INTO EASTERN
PORTIONS OF CHIPPEWA COUNTY EARLY THIS EVENING. WITH FLOW
GRADUALLY EXPECTED TO VEER MORE NORTHWEST TONIGHT...IT SHOULD
PUSH THE ACTIVITY WEST OF THE SAULT WITH TIME. WILL MONITOR THAT
AREA BUT NOT ISSUE ANY ADVISORIES AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 408 PM EDT WED OCT 23 2013
CURRENTLY, THE SFC AND 500 MB LOWS ARE LOCATED EAST OF HUDSON BAY
WITH THE VARIOUS TROUGHS AT 500 MB, AND THE SFC ROTATING AROUND
THEM. THIS HAS CONTINUED THE NW FLOW LAKE EFFECT PATTERN OF THE LAST
2 DAYS. THE MAIN CONCERN WILL AGAIN BE THE PRECIPITATION TYPE
OVERNIGHT AS THE LAKE INFLUENCE HASN`T BEEN MUCH TO SLOW THE SNOW
MACHINE DOWN.
TONIGHT...WHILE THERE HAS BEEN RAIN MIXED IN AT THE SHORELINES, THE
MAJORITY OF THE DAY WAS SNOW SHOWERS IN THE HIGHER ELEVATIONS AND IN
SAULT STE. MARIE. WHILE THE WARM AIR AND RAIN WAS SHOWING UP OVER
WHITEFISH BAY, THE COOLER AIR STAYED IN AT ANJ WHERE THEY GOT 4.1
INCHES BY THE AFTERNOON. SO CONSIDERING THAT THE LES PATTERN WILL
CONTINUE TO BE NW INTO THE SOO FOR THE EVENING, WILL PUT MORE SNOW
INTO THE FORECAST THERE FOR THE EVENING AS THIS WINDS DOWN.
THIS EVENING IN N LOWER, THE DIURNAL RAIN/SNOW MIX (AND IT IS MOSTLY
RAIN) HAS BEEN FILLING THE RADAR THE LAST 2 HOURS WITH THE
INSTABILITY OF THE -32C 500 MB AIR IS OVER US. ADD TO THAT THE 850
MB -6C AIR AND WE HAVE BEEN GETTING CALLS ABOUT GRAUPEL ALL
AFTERNOON. ALL OF THIS WILL SETTLE DOWN ONCE THE SUN SETS AND THE
LAKE EFFECT BANDS BECOME MORE ORGANIZED INTO THE NW FLOW PATTERN.
DEPENDING ON HOW THIS TURNS OUT, THERE COULD BE LIGHT AMOUNTS IN NW
LOWER. THERE IS A LOW PROBABILITY FOR A MODERATE AMOUNT OF SNOW, BUT
THE MODELS ARE PRETTY BULLISH AT WARMING THINGS TO ABOVE -6C BY 0Z.
OVERNIGHT, 850 MB WARM TO ABOVE -5C ON THE NAM/WRF ABOVE -6C ON THE
GFS AND REMAINS BELOW -6C ON THE ECMWF. LOOKING AT THE HRRR ANALYSIS
NORTH OF LAKE SUPERIOR AS A POCKET OF -4C AIR THAT SHOULD BE
ROTATING SOUTH INTO THE UPPER GREAT LAKES OVERNIGHT. SO WILL GO WITH
THE AVERAGE OF THE MODELS WITH THE -5C AIR. WE`LL SEE IF THIS IS
RIGHT. IF THE TEMPERATURES WARM ENOUGH, THEN THE LAKES WILL HAVE
MORE INFLUENCE IN THE LOWER LEVELS AND MORE RAIN WILL MIX IN
OVERNIGHT. IF NOT, THEN THE SNOW AMOUNTS ARE ON THE LOW SIDE. BY 12Z
THE FLOW SHOULD HAVE CHANGED TO A NNW FLOW PATTERN AND SHUT OFF AT
ANJ AND WILL SHIFT SOME OF THE PRECIPITATION TOWARD THE WEST IN NW
LOWER SO THAT IT IS CLOSER TO TVC.
(10/24)THURSDAY...THE MODELS ALL SAY THAT THE NNW FLOW PATTERN
REMAINS BUT NOW THE ECMWF HAS THE WARMER 850 MB TEMPERATURES (BELOW
-6C. SO WILL MIX THE RAIN INTO THE SNOW AGAIN AND GO WITH ALL RAIN
BY THE AFTERNOON. IF THE NAM IS RIGHT THERE COULD BE RAIN ALL DAY.
IF THE GFS AND ECMWF ARE RIGHT THEN THERE WILL BE A BETTER MIX IN
THE MORNING, WITH THE AFTERNOON TURNING OUT WITH LAKE EFFECT RAIN.
I`M BANKING MORE TOWARD THE GFS/ECMWF SOLUTION AS THE NAM SEEMS TO
BE THE OUTLIER IN THIS CASE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 408 PM EDT WED OCT 23 2013
RECENT TRENDS...TEMPERATURES: 1-2F BELOW NORMAL LAST SEVEN DAYS...
BUT STILL SOLIDLY ABOVE AVERAGE FOR OCTOBER GIVEN OUR WARM FIRST
HALF (2-4+F ABOVE). PRECIPITATION/HYDROLOGY: LAST 7 DAYS 100-200
PERCENT OF NORMAL MUCH OF NORTHERN LOWER...200-300+ PERCENT OF
NORMAL ACROSS THE TIP OF THE MITT DUE TO RECENT LAKE EFFECT. DRIER
ACROSS EASTERN UPPER (25-75 PERCENT OF NORMAL CHIPPEWA COUNTY).
SIMILAR PERCENTAGES FOR TOTAL MONTH PRECIP DEPARTURES. RECENT
WETTER CONDITIONS ACROSS THE TIP OF THE MITT ALSO EVIDENT IN 30
DAY STANDARDIZED PRECIP INDEX ANALYSIS...ALONG WITH SOME DRYNESS
ACROSS EASTERN UPPER. RECENT PRECIP SURPLUS ALSO SHOWING UP IN
ABOVE NORMAL STREAMFLOWS WITHIN THE JORDAN/CHEBOYGAN/THUNDER BAY
RIVER BASINS.
SYNOPSIS...AMPLIFIED LONG WAVE TROUGH AXIS ACROSS CENTRAL NORTH
AMERICA...AND SUPPORTING +PNA RIDGE ALONG THE WEST COAST. PART OF A
BALANCED FOUR WAVE HEMISPHERIC PATTERN. UPPER LAKES REMAIN UNDER
THE INFLUENCE OF LOW PRESSURE OVER NORTHWEST QUEBEC...KEEPING SOME
SEMBLANCE OF CYCLONIC FLOW IN PLACE WHICH IS HELPING TO DRIVE
CONVECTIVE SHOWERS (BOTH OF THE LAKE AND DIURNAL VARIETY).
SYNOPTIC PATTERN OVER THE NEXT WEEK DOESN`T CHANGE MUCH INITIALLY AS
LONG WAVE FEATURES ARE PRETTY WELL ANCHORED IN PLACE. NORTHERN
PORTION OF A SPLIT SHORT WAVE TROUGH CURRENTLY OUT AROUND 145W WILL
CREST THE WEST COAST RIDGE AND DIG SOUTHEAST TOWARD THE UPPER
MIDWEST/UPPER GREAT LAKES BY THIS WEEKEND...HELPING REINFORCE THE
MEAN TROUGH POSITION. SOME CHANGES MAY BE IN THE OFFING FOR NEXT
WEEK...LIKELY SOMEWHAT IN RESPONSE TO THE EXTRATROPICAL TRANSITION
OF TYPHOON "FRANCISCO" WHICH HAS BEEN DRIFTING NORTHWEST TO THE
SOUTH OF JAPAN OVER THE LAST 24 HOURS. AS THE REMNANTS OF THIS
FEATURE GET ABSORBED INTO THE WESTERLIES...LOOKS AS IF IT WILL SEND
A TRAIN OF ENERGY EAST ACROSS THE PACIFIC AND RESULTING IN A SHARP
AMPLIFICATION OF RIDGING OVER THE NORTHEAST PACIFIC/WESTERN CANADA
EARLY NEXT WEEK. THIS IN TURN WILL ALLOW HEIGHT FALLS TO DROP INTO
THE WESTERN U.S...POSSIBLY IN THE FORM OF A SPLIT TROUGH WHICH COULD
BRING THE GREAT LAKES INTO MORE WEST/SOUTHWEST FLOW ALOFT WITHIN
SOUTHERN BRANCH OF THIS SPLIT.
LOW LEVEL WINDS THROUGH THURSDAY LOOK TO STILL BE DOMINATED BY BROAD
CYCLONIC CIRCULATION OVER EASTERN CANADA...AS A NARROW RIDGE OF HIGH
PRESSURE SLIDES DOWN THE PLAINS AND INTO THE MIDDLE/LOWER
MISSISSIPPI VALLEY BY FRIDAY. IN RESPONSE TO THIS...AND AHEAD OF A
WEAK LOW ASSOCIATED WITH DIGGING SHORT WAVE ENERGY OVER CENTRAL
CANADA...WINDS EXPECTED TO BACK SOUTHWEST AND WARM ADVECTION KICKS
IN FOR FRIDAY. SHORT WAVE TROUGH FORECAST TO CROSS MICHIGAN
SATURDAY WITH A QUICK REINFORCING PUSH OF COLDER AIR IN ITS WAKE.
AS FLOW SPLITS OUT WEST EARLY NEXT WEEK...NORTHERN BRANCH SHORT WAVE
TROUGH FORECAST TO PASS NORTH OF THE GREAT LAKES THOUGH MAY PUSH A
COLD FRONT INTO THE REGION. STRONGER HEIGHT FALLS INTO THE WEST AS
A COLD AIR MASS INVADES THE NORTHERN ROCKIES/INTERMOUNTAIN WEST.
ASSOCIATED POLAR HIGH EXPANDS EAST TOWARD THE GREAT LAKES BY MIDWEEK
AND SETS UP AN EXTENSIVE NORTH-SOUTH THERMAL GRADIENT ACROSS THE
CENTRAL U.S. THIS AREA WILL NEED TO BE WATCHED TOWARD THE MIDDLE
AND END OF NEXT WEEK FOR POTENTIAL DEVELOPMENT WITH A STRONG UPPER
TROUGH OVER THE GREAT BASIN.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...NEAR TERM FORECAST ISSUES WILL
CONTINUE TO DEAL WITH LINGERING LAKE CONVECTION AND IMPACTS OF
DEVELOPING WARM ADVECTION PATTERN FRIDAY. THURSDAY NIGHT LOOKS LIKE
MUCH OF THE SAME OF THE PAST SEVERAL DAYS WITH SYNOPTIC MOISTURE
DROPPING IN FROM THE NORTH WITH COLD AIR IN PLACE AND INVERSION
HEIGHTS STILL IN THE 700-800MB RANGE...SO MORE NORTHWEST FLOW LAKE
EFFECT SHOWERS FOCUSED PRIMARILY ON EASTERN UPPER AND NORTHWEST
LOWER (COVERAGE EXPECTED WANE DURING THE EVENING OVER SOUTHEAST
PORTION OF THE FORECAST AREA ESPECIALLY WITH LOSS OF DIURNAL
COMPONENT). PRECIPITATION TYPE SHOULD TRANSITION TOWARD MORE SNOW
ESPECIALLY INLAND FROM LAKE MICHIGAN/WHITEFISH BAY...COUPLE INCHES
OF SNOW A POSSIBILITY ACROSS PARTS OF NORTHWEST LOWER DEPENDING ON
HOW ORGANIZED THINGS GET. BOUNDARY LAYER WINDS WILL BE BACKING
FRIDAY...THOUGH RAIN/SNOW SHOWERS WILL BE ONGOING AT DAYBREAK FRIDAY
AND MAY GET SOME AUGMENTATION OF COVERAGE THROUGH DIURNAL HEATING
(GUIDANCE QPF IS DRIER THAN THIS IDEA...BUT GIVEN INERTIA ARGUMENTS
AND THE TYPICAL TENDENCY TO END LAKE INDUCED PRECIPITATION TOO
QUICKLY WILL NOT DRY THINGS OUT DURING THE AFTERNOON. IF IT
ENDS...CONSIDER IT A BONUS). LOW LEVEL WARM ADVECTION EXPECTED TO
STRENGTHEN FRIDAY NIGHT AS LOW LEVEL JET IMPINGES UPON THE UPPER
GREAT LAKES TO THE SOUTH OF THE APPROACHING SURFACE LOW OUT OF
NORTHWEST ONTARIO. EXPECT THIS TO SPREAD AN AREA OF PRECIPITATION
ACROSS NORTHERN MICHIGAN STARTING FRIDAY EVENING...PROBABLY MOSTLY
IN THE FORM OF RAIN THOUGH MAY START AS A MIX OR ALL SNOW ACROSS THE
HIGHER TERRAIN OF NORTHERN LOWER.
EXTENDED FORECAST (SATURDAY THROUGH WEDNESDAY)...SHARP THERMAL
TROUGHING ASSOCIATED WITH SHORT WAVE TROUGH PASSAGE SATURDAY...
COMBINED WITH SOME DEEPER LAYER SYNOPTIC MOISTURE EXPECTED TO
TRANSITION THINGS BACK OVER TO MORE LAKE/DIURNAL CONVECTIVE SHOWERS
DURING THE DAY. SHOULD BE A BREEZY DAY AS WELL WITH WINDS SWINGING
BACK AROUND TO THE WEST/NORTHWEST. SUNDAY WILL SEE NEXT SHORT WAVE
DIGGING SOUTHEAST ACROSS CENTRAL CANADA PUSHING THE NEXT COLD FRONT
TOWARD THE UPPER LAKES. THERE IS UNCERTAINTY REGARDING TIMING OF
THIS FEATURE AND HOW FAR SOUTH IT ULTIMATELY PUSHES BASED ON
STRENGTH OF SURFACE RIDGE AXIS PUSHING EAST ACROSS CANADA. ECMWF
MUCH MORE AGGRESSIVE AND PROBABLY NOT UNREASONABLE...GFS HAS BEEN
GOING BACK AND FORTH OVER THE PAST THREE RUNS. AT LEAST FOR SUNDAY
THERE SHOULD BE SOME RESIDUAL LAKE CONVECTION AROUND...BUT IF WE CAN
SHOVE THE NEXT COLD FRONT FAR ENOUGH SOUTH MAY FINALLY GET AWAY WITH
A SHOT AT A DRY DAY MONDAY. PATTERN SETS UP FAVORABLY FOR AN
OVERRUNNING PRECIP EVENT HEADING INTO TUESDAY...POSSIBLY DRY TO
START THE NEW WEDNESDAY FORECAST THOUGH PLENTY OF UNCERTAINTY
DEPENDING ON HOW UPSTREAM ENERGY EVOLVES (AND WITH TYPHOON
EXTRATROPICAL TRANSITION GETTING INVOLVED...PLENTY OF CHANGES
LIKELY). TEMPERATURES TO REMAIN BELOW NORMAL THROUGH THE EXTENDED
PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 647 PM EDT WED OCT 23 2013
MVFR CIGS/VSBYS WITH POCKETS OF IFR VSBYS WITHIN MORE INTENSE
RAIN/SNOW SHOWER ACTIVITY. WINDS FROM THE NORTHWEST AROUND 10
KNOTS WITH A FEW HIGHER GUSTS.
&&
.MARINE...
ISSUED AT 408 PM EDT WED OCT 23 2013
THE WINDS TOOK A BIT OF TIME TO START GUSTING TODAY DUE TO THE WEAK
GRADIENT, BUT ARE EXPECTED TO INCREASE A BIT TONIGHT AS THE NEXT SFC
TROUGH ROTATES INTO THE UPPER GREAT LAKES. HOWEVER, THE MAIN CONCERN
WILL BE THE WAVES OVER THE NEXT 36 HOURS AS THE NW WIND WILL
CONTINUE TO KEEP WAVE HEIGHT OVER 4 FEET WHICH IS SMALL CRAFT
CRITERIA. FRIDAY, IT LOOKS LIKE THE GRADIENT SLACKENS SO THAT THE
WINDS WILL DIMINISH AND THE WAVES WILL SUBSIDE.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EDT THURSDAY FOR MIZ019-
021-022-027-028.
LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LHZ346.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR LHZ345-347>349.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ341.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR LMZ323-342-
344>346.
LS...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LSZ322.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR LSZ321.
&&
$$
UPDATE...JK
SYNOPSIS...SWR
SHORT TERM...JSL
LONG TERM...JPB
AVIATION...JK
MARINE...JSL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
119 PM EDT TUE OCT 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EDT TUE OCT 22 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE INTO THE WRN CONUS AND
A BROAD DOWNSTREAM TROUGH OVER THE CNTRL AND ERN CONUS. A MID LEVEL
LOW JUST NORTH OF THE SAULT WAS LIFTING SLOWLY TO THE ENE. AT THE
SFC...LOW PRES WAS LOCATED A THE SRN END OF JAMES BAY WITH A TROUGH
EXTENDING TO THE SW THROUGH ERN LAKE SUPERIOR INTO ERN UPPER MI. AFTER A
BRIEF PERIOD OF MODERATE TO HEAVY SNOW ASSOCIATED WITH LOW LEVEL
CONV AHEAD OF THE TROUGH...WIND PARALLEL SNOW BANDS HAVE DEVELOPED
BUT WITH LESS ORGANIZED CONVECTIVE ELEMENTS. SNOWFALL AMOUNTS WERE
IN THE 1 TO 3 INCH RANGE OVER THE WEST DURING THE EVENING BUT HAVE
ONLY AMOUNTED TO LESS THAN INCH OVER N CNTRL UPPER MI NEAR NEGAUNEE.
WITH LOW LEVEL TEMPS NEAR FREEZING AND MILD AIR MOVING IN FROM THE
RELATIVELY WARM LAKE SUPERIOR...WATER TEMPS IN THE UPPER 40S...WET
BULB ZERO HEIGHTS HAVE REMAINED HIGH ENOUGH FOR THE SNOW TO CHANGE
BACK TO MAINLY RAIN OVER THE KEWEENAW AND ALONG LAKE SUPERIOR TO THE
EAST.
TODAY...EXPECT THE LAKE ENHANCED SNOW BANDS TO CONTINUE AS CAA DROPS
850 MB TEMPS FROM AROUND -7C TO NEAR -9C. HOWEVER...WITH DRIER AIR
MOVING INTO THE REGION AND LOWER INVERSION HEIGHTS IN THE PRESENCE OF
SYNOPTIC SCALE SUBSIDENCE BEHIND THE DEPARTING MID LEVEL LOW...THE
SNOW SHOWER INTENSITY/COVERAGE WILL DIMINISH THIS MORNING LEAVING
JUST SCT LIGHT SNOW/RAIN SHOWERS BY AFTERNOON.
TONIGHT...THE MODELS SUGGEST A WEAK SHORTWAVE TROUGH MAY SLIDE INTO
THE AREA. WITH 850 MB TEMPS REMAINING NEAR -8C...AN INCREASE IN
850-700 MB MOISTURE...AND MORE FAVORABLE LOW LEVEL CONV AS LAND
BREEZES DEVELOP...SNOW SHOWERS ARE EXPECTED TO INCREASE FOR
LOCATIONS FAVORED TY NW TO WNW FLOW. HOWEVER...GIVEN THE MARGINAL
INSTABILITY...ANY ACCUMULATIONS ARE EXPECTED TO REMAIN AT AN INCH OR
LESS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM EDT TUE OCT 22 2013
THE UPPER GREAT LAKES WILL STILL BE UNDER THE WESTERN SIDE OF THE
UPPER TROUGH AT THE START OF THE LONG TERM PERIOD...WHICH WILL
REMAIN IN PLACE THROUGH THURSDAY NIGHT. AT THE SURFACE...A LOW WILL
BE LOCATED TO THE EAST OF JAMES BAY AND HIGH PRESSURE WILL BE
SLIDING SOUTHEAST THROUGH THE NORTHERN PLAINS THROUGH THURSDAY. THIS
WILL ALLOW NORTHWEST FLOW TO BE PERSISTENT ON WEDNESDAY AND
THURSDAY. 850MB TEMPS DURING THIS PERIOD LOOK TO BE HOVERING RIGHT
AROUND -7 TO -8C AND WITH LAKE SUPERIOR TEMPS ON AVERAGE AROUND
8-9C...THERE IS PLENTY OF OVER LAKE INSTABILITY TO SUPPORT LAKE
EFFECT SHOWERS. ON WEDNESDAY MORNING...EXPECT THE WINDS TO BE NW TO
WNW...BEFORE A WEAK SURFACE TROUGH AND SHORTWAVE SWEEPS THROUGH
WEDNESDAY EVENING AND SHIFTS THE DIRECTION TO A MORE
NORTH-NORTHWESTERLY DIRECTION. WILL HAVE THE HIGHEST POPS EAST OF
GRAND MARAIS OVER THE EAST AND ALONG ALL OF THE HIGHER TERRAIN OVER
THE WEST FOR WEDNESDAY...THEN SHIFTING TO MORE TRADITIONAL NW-NNW
FLOW LOCATIONS FOR WEDNESDAY NIGHT (EG ALGER COUNTY OVER THE EAST).
WILL CONTINUE TO SHOW DEFINITE POPS FOR THE FAVORED EASTERN CWA
LOCATIONS SINCE THE MODELS HAVE BEEN CONSISTENT ON THIS IDEA FOR THE
LAST COUPLE OF DAYS. WILL CONTINUE THE HIGH POPS FOR
THURSDAY...ALTHOUGH TEMPS MAY WARM A DEGREE. EVEN WITH THE
LIKELY/DEFINITE POPS FOR WEDNESDAY...DON/T EXPECT THE INTENSITY TO
BE AS STRONG AS LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT WHEN A
QUICK PERIOD OF DEEPER MOISTURE WITH THE SHORTWAVE AND SURFACE
TROUGH MOVES THROUGH. DEEP CLOUD LAYER (10-12KFT) AND LAKE INDUCED
CAPE VALUES OF 300-500 J/KG SUPPORT THE POTENTIAL FOR STRONGER LAKE
EFFECT SNOW BANDS ON WEDNESDAY NIGHT. THIS COULD EVEN END UP
PRODUCING MODERATE TO HEAVY SNOWFALL IN QUICK BURSTS...SIMILAR TO
WHAT WAS SEEN IN PORTIONS OF WESTERN UPPER MICHIGAN THIS
AFTERNOON/EVENING (JACOBSVILLE SAW 2.6IN IN 1HR).
THE MAIN LIMITING FACTORS FOR THIS EVENT WILL BE THE LOWER
SNOW RATIOS AND MID-UPPER 30S NEAR SURFACE TEMPERATURES. CONTINUE TO
THINK SNOW RATIOS WILL BE ON THE LOW END FOR TRADITIONAL LAKE EFFECT
EVENTS...SINCE THE CLOUD LAYER WILL BE AT OR BELOW THE DGZ.
THUS...WITH MUCH OF THE FORCING BELOW...WOULD EXPECT RATIOS TO BE IN
THE 10-13 TO 1 RANGE INSTEAD OF THE NORMAL 17-25 TO 1. IN
ADDITION...WITH UPPER 40 DEGREE WATER MODIFYING THE NEAR SURFACE
AIR...LOCATIONS NEAR LAKE SUPERIOR WILL BE HOVERING IN THE MID TO
EVEN UPPER 30S. THIS WILL TRY TO PUSH WETBULB ZERO VALUES UP TO
1KFT...WHICH WOULD BE ENOUGH FOR SOME MIXING OF RAIN/SNOW NEAR THE
SHORELINE. IN ADDITION...THOSE WARMER SURFACE TEMPERATURES WILL
ATTEMPT TO LIMIT THE SNOWFALL ACCUMULATION EXCEPT UNDER THE STRONGER
BANDS...WHERE THE RATE WILL COMPENSATE FOR THE WARMER TEMPS.
THEREFORE...PINNING DOWN SNOWFALL AMOUNTS WITH THE MULTIPLE FACTORS
IS TRICKY FOR THIS EARLY SEASON EVENT. IN GENERAL...THINK THE
SNOWFALL AMOUNTS DURING THE WEDNESDAY AFTERNOON/NIGHT PERIOD WILL
BE UNDER ADVISORY CRITERIA (GENERALLY 1-3INCH) WITH SOME LOCATIONS
SEEING ADVISORY AMOUNTS (3-4INCH) WHERE ANY STRONGER BANDS SETS UP.
ONE OTHER ITEM TO MENTION FOR THE WEDNESDAY AFTERNOON AND NIGHT
PERIOD IS THE POTENTIAL FOR SOME WATERSPOUTS OVER THE SOUTHEASTERN
PART OF LAKE SUPERIOR. WITH THE CONVECTIVE CLOUD DEPTH OF 10-12KFT
AND DELTA-T VALUES AROUND 16...THAT DOES PLACE THAT AREA ON THE
EDGE OF THE WATERSPOUT POTENTIAL ON THE SZILAGYI WATERSPOUT
NOMOGRAM. THUS...WILL PUT IN A SLIGHT CHANCE MENTION IN THAT AREA
AND THEN END IN BY THURSDAY MORNING SINCE THE MOISTURE DEPTH BEGINS
TO LESSEN.
THE UPPER TROUGH WILL FINALLY BEGIN SHIFTING EAST ON THURSDAY NIGHT
AND A HIGH PRESSURE RIDGE WILL BEGIN TO MOVE EAST INTO THE UPPER
GREAT LAKES. THIS WILL BRING DRIER AIR INTO THE CWA FROM WEST TO
EAST WHILE BACKING THE WINDS TO THE SOUTHWEST. THUS...EXPECT THE
ONGOING LAKE EFFECT PRECIPITATION TO DIMINISH OVER THE WEST AND
THEN SLOWLY DIMINISH AND SHIFT EAST OVER THE EASTERN CWA.
FORTUNATELY...THE MODELS HAVE COME INTO MUCH BETTER AGREEMENT WITH
THE SHORTWAVE ROUNDING THE UPPER RIDGE OVER THE WEST AND SLIDING
SOUTHEAST INTO THE UPPER GREAT LAKES REGION ON FRIDAY NIGHT INTO
SATURDAY. THIS CLIPPER SYSTEM (WITH THE LOW SLIDING ALONG THE
EASTERN SHORE OF LAKE SUPERIOR) SHOULD PRODUCE SOME PRECIPITATION
OVER THE CWA ON FRIDAY NIGHT AND HAVE THE HIGHEST POPS OVER THE
NORTHEAST HALF. THEN AFTER THE COLD FRONT MOVES THROUGH...EXPECT
THERE TO BE A PERIOD OF LAKE ENHANCED RAIN/SNOW IN THE NORTHWEST
WIND FAVORED LOCATIONS AS 850MB TEMPS FALL BACK TO -6C. WILL
HIGHLIGHT THE HIGHEST POPS IN THOSE LOCATIONS FOR SATURDAY AND THEN
GRADUALLY DIMINISH THEM SATURDAY NIGHT INTO SUNDAY...AS THE UPPER
TROUGH SHIFTS EAST AND HIGH PRESSURE MOVES OVER THE CWA. IT LOOKS
LIKE THE SUNDAY INTO SUNDAY NIGHT PERIOD WILL GIVE A LITTLE BIT OF A
REPRIVE TO THE UNSETTLED WEATHER THAT WE WILL SEE THIS WEEK. LATEST
TRENDS IN THE 00Z MODEL RUNS HAVE THE UPPER TROUGH THAT WILL BE
DIGGING OVER THE ROCKIES POTENTIALLY BECOMING CUTOFF OVER THE WEST
COAST. AS THIS OCCURS ON MONDAY...AN ELONGATED TROUGH ASSOCIATED
FROM A LOW IN THE CENTRAL PLAINS WILL SLOWLY MOVE EAST ACROSS THE
AREA. THIS WILL BE SOMETHING TO KEEP AN EYE ON...AS TEMPERATURES
WILL LIKELY BE COLD ENOUGH FOR SNOW ALOFT (ALTHOUGH SURFACE
TEMPERATURES ARE MARGINAL) AND IT COULD PRODUCE MEASURABLE SNOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 119 PM EDT TUE OCT 22 2013
EXPECT MVFR WX TO DOMINATE MOST OF THIS FCST PERIOD WITH LAKE EFFECT
SNOW SHOWERS. AT SAW...AS WINDS BACK TO THE WEST IN THE
EVENING...THIS WILL PUSH LAKE EFFECT CLOUDS OUT AND VFR CONDITIONS
WILL CONTINUE OVERNIGHT. AS WINDS PICK UP AGAIN...WEST WINDS PICK UP
AGAIN AND GUSTY WINDS WILL PUSH MVFR CLOUDS BACK IN AGAIN BY MID WED
MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EDT TUE OCT 22 2013
NORTH TO NORTHWEST GALES THIS MORNING ARE EXPECTED TO DIMINISH BY
AFTERNOON AS THE GRADIENT WEAKENS BEHIND A DEPARTING TROUGH.
HOWEVER...WITH PERSISTENT LOW PRES TO THE EAST AND RIDGE OVER THE
NORTHERN PLAINS...WINDS WILL BE LINGER IN THE 20 TO 30KT RANGE
THROUGH THE THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
100 PM EDT TUE OCT 22 2013
.AVIATION...
//DISCUSSION...
THE SPREAD OF STRATOCU ACROSS THE TAF SITES HAS DROPPED BKN CIGS TO
3-5 KFT. EXPECTING VFR FOR MOST OF THE PERIOD...EXCEPT A BRIEF DROP
TO MVFR OVERNIGHT IN DETROIT SITES AS A DISTURBANCE IS EXPECTED TO
BRING ISOLATED SHOWERS TO THE AREA. THE CONVECTIVE ELEMENT OF THE
CLOUD DECK WILL DISSIPATE TONIGHT...AROUND THE SAME TIME AN UPPER
WAVE BRINGS PRECIP CHANCES TO SRN SITES. EXPECTING THE 3 NRN SITES
TO CLEAR OUT AS THE CEILING LIFTS AND MORE DRY AIR WILL LEAD TO SCT
VFR FOR MUCH OF WED. COLD AIR INFILTRATING THE REGION WILL LEAD ANY
/UNLIKELY/ PRECIP TO BE A RASN MIX AT MBS EARLY WED.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THIS AFTERNOON INTO
THE OVERNIGHT PERIOD.
&&
.PREV DISCUSSION...ISSUED 347 AM EDT TUE OCT 22 2013
SHORT TERM... TODAY AND TONIGHT
CONFLUENT FLOW ALOFT THROUGH THE SOUTH FLANK OF THE UPPER LOW WILL
MAINTAIN THE MID LEVEL DRY SLOT OVER THE SOUTHERN GREAT LAKES FOR
MOST OF TODAY. THIS WILL KEEP THE INFLUENCE OF LAKE MICHIGAN SUBDUED
ON THIS SIDE OF THE STATE, ESPECIALLY IN TERMS OF PRECIPITATION AND
POSSIBLY EVEN CAUSING A DISRUPTION IN THE CLOUD FIELD. TRENDS IN LOW
LEVEL RH PROFILES IN THE NAM AND RAP MODELS INDICATE DRY AIR FROM
THE MIDWEST AS LOW AS 850 MB DURING THE MORNING WHICH COULD LEAD TO
SOME BREAKS IN THE LAKE CLOUD PATTERN OR A TENDENCY FOR THE CLOUDS
TO HUG CLOSER TO THE SHORELINE OVER SW LOWER EARLY IN THE DAY. THE
LATEST SATELLITE IMAGERY SUPPORTS A GENERAL PARTLY SUNNY START TO
THE DAY AND ALLOWS FOR SOME RENEWED STRATOCU FORMATION DUE TO
SURFACE HEATING AND BEFORE HIGH CLOUDS INCREASE WITH THE NEXT SHORT
WAVE LATE IN THE DAY. THE BREAKS OF SUNSHINE WILL HELP MAX TEMPS
RECOVER INTO THE MID AND UPPER 40S.
THE NEXT SHORT WAVE WILL ARRIVE OVER INDIANA FROM THE CENTRAL PLAINS
BY EVENING NEARLY IN PHASE WITH THE SECONDARY SURFACE TROUGH SLIDING
THROUGH THE NORTHERN GREAT LAKES. THE SURFACE TROUGH WILL MOVE
THROUGH SE MICHIGAN DURING THE LATE AFTERNOON AND EVENING WHILE THE
SHORT WAVE APPROACHES THE SOUTHERN MICHIGAN BORDER. THE COMBINATION
OF THESE TWO FEATURES WILL GIVE INSTABILITY OVER LAKE MICHIGAN A
CHANCE TO PERK UP, ALONG WITH BOUNDARY LAYER INSTABILITY DUE TO
SURFACE HEATING, FOR A CHANCE OF LIGHT RAIN SHOWERS DURING THE LATE
AFTERNOON. THE BEST CHANCE OF RAIN WILL BE DURING THE EVENING
GENERALLY SOUTH OF THE I-69 CORRIDOR WHERE THE NORTH FLANK OF THE
SHORT WAVE FORCING WILL INTERACT WITH THE SURFACE TROUGH. THIS
REFLECTS A SOUTHWARD MODEL ADJUSTMENT ON TRACK OF SHORT WAVE WITH
THE MID LEVEL TROWAL AXIS REMAINING SOUTH OF THE STATE LINE. MODEL
DEPICTIONS OF DCVA ARE TOO WEAK TO GO WITH ANYTHING GREATER THAN A
CHANCE POP BEFORE THE SYSTEM EXITS EASTWARD AFTER MIDNIGHT. MOST OF
THE OVERNIGHT HOURS WILL THEN BE DOMINATED BY RENEWED LOW LEVEL COLD
ADVECTION ON NW FLOW. BOTH THICKNESS FIELDS AND MODEL SOUNDINGS
INDICATE PRECIPITATION POTENTIAL ENDED BY THE TIME THE BOUNDARY
LAYER COOLS ENOUGH FOR SNOW, AND AS NORTHWEST FLOW CONFINES LAKE
EFFECT CLOSER TO LAKE MICHIGAN. MIN TEMPS NEAR THE FREEZING MARK
LOOK ON TARGET BY SUNRISE WEDNESDAY.
LONG TERM...
LONGWAVE TROUGHING ANCHORED BY A LARGE CLOSED LOW OVER THE GREAT
LAKES WILL MAINTAIN MOIST CYCLONIC FLOW OVER THE AREA UNTIL THE
DEPARTURE OF THE LOW TO THE NORTHEAST LATE IN THE WEEK. IN THE
MEANTIME, NORTHWEST GRADIENT FLOW AROUND THE EASTERN FLANK OF HIGH
PRESSURE BUILDING INTO THE CENTRAL CONUS WILL KEEP DAYTIME HIGHS IN
THE MID TO UPPER 40S BENEATH H85 TEMPS PROGGED TO HOVER AROUND -5C.
IN GENERAL, NORTHWEST FLOW WILL MINIMIZE CONCERN FOR LAKE EFFECT SHOWERS
TO ADVANCE INTO THE AREA AS CONVECTIVE PLUMES OFF OF LAKE MICHIGAN
WILL TEND TO BE SHUNTED TO OUR SOUTHWEST.
THE EXCEPTION WILL BE WEDNESDAY WHEN THE LOW LEVEL FLOW IS PROGGED
TO BACK TOWARD WESTERLY AHEAD OF AN APPROACHING SHORTWAVE. WITH THE
HELP OF DIURNAL HEATING, A DEEP CONVECTIVE BOUNDARY LAYER WITH
ORIGINS OVER LAKE MICHIGAN STANDS A DECENT CHANCE OF ADVECTING EAST
INTO THE AREA. CHANCE POPS THEREFORE REMAIN IN PLACE FOR WED
AFTERNOON, WITH THE BEST CHANCE FOR SHOWERS SOUTH OF I-69. LOW-LEVEL
FLOW WILL BACK TO A LESSER DEGREE ON WED NIGHT AS A SHEARED H5 PV
ANOMALY TRACKS ACROSS THE MI/OH BORDER. DYNAMIC FORCING ASSOCIATED
WITH THE WAVE ITSELF WARRANTS CHANCE POPS NEAR THE OHIO BORDER, BUT
POTENTIAL WILL BE LIMITED WITH THE DEEPER MOISTURE CONFINED TO THE
OHIO VALLEY.
MOIST CYCLONIC FLOW IN ADDITION TO CONTRIBUTIONS FROM LAKE
SUPERIOR/MICHIGAN WILL ENSURE A SUBSTANTIAL BOUNDARY LAYER
CONTRIBUTION TO A MOSTLY CLOUDY SKY CONDITION THAT IS FORECAST TO
PERSIST THROUGH AT LEAST THURSDAY NIGHT. INHERITED FORECAST LOWS
NEAR 30 FOR MOST AREAS STILL LOOK REASONABLE, BUT ANY POTENTIAL FOR
CLEARING WILL BE WORTH MONITORING AS A FEW HOURS OF GOOD RADIATING
WITHIN THE RESIDENT AIRMASS WOULD SEND TEMPS WELL INTO THE 20S.
SHORTWAVE RIDGING IN ADVANCE OF ANOTHER HIGH-LATITUDE WAVE WILL WORK
INTO THE AREA ON FRIDAY AGAINST A BACKDROP OF LARGER SCALE HEIGHT
RISES OWING TO EASTWARD PROGRESSION OF THE LONGWAVE TROUGH. HIGH
PRESSURE WILL BUILD INTO THE AREA AS A RESULT AND SHOULD HELP BREAK
UP BOUNDARY LAYER CLOUD COVER TO SOME EXTENT, BUT HIGHS WILL AGAIN
REMAIN IN THE 40S WITH THE THERMAL TROUGH PROGGED TO MAINTAIN ITS
GRIP ON THE AREA.
MARINE...
A SECONDARY SURGE OF COLD AIR SPREADING OVER THE GREAT LAKES TODAY
WILL REQUIRE GALE WARNINGS TO CONTINUE OVER NORTHERN AND CENTRAL
LAKE HURON. WARNINGS HAVE BEEN ADDED FOR SAGINAW BAY AS FREQUENT
GUSTS TO 35 KNOTS ARE NOW EXPECTED THERE AS THE WIND FUNNELS DOWN
THE CENTER OF THE BAY. SMALL CRAFT ADVISORIES WILL HOLD ALONG THE
SOUTHERN LAKE HURON NEARSHORE AREAS. THE STRONG WIND WILL KEEP
WATERSPOUT POTENTIAL LOW EVEN AS INSTABILITY INCREASES OVER THE
WATER TODAY WITH A BETTER CHANCE OVER THE OPEN WATERS OF LAKE HURON
TONIGHT AS THE WIND DIMINISHES. WIND SPEED WILL CONTINUE TO DIMINISH
TUESDAY NIGHT INTO WEDNESDAY BUT WILL REMAIN FROM THE NORTHWEST AND
WEST, MAINTAINING BELOW NORMAL TEMPERATURE THROUGH THE END OF THE
WEEK.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
GALE WARNING...LHZ361-LHZ362-LHZ363-LHZ421-LHZ422...UNTIL 8 PM
TUESDAY.
SMALL CRAFT ADVISORY...OUTER SAGINAW BAY...FROM 8 PM TUESDAY TO 8
AM WEDNESDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
SANILAC...UNTIL 8 AM WEDNESDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MM
SHORT TERM...BT
LONG TERM....JVC
MARINE.......BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
747 AM EDT TUE OCT 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EDT TUE OCT 22 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE INTO THE WRN CONUS AND
A BROAD DOWNSTREAM TROUGH OVER THE CNTRL AND ERN CONUS. A MID LEVEL
LOW JUST NORTH OF THE SAULT WAS LIFTING SLOWLY TO THE ENE. AT THE
SFC...LOW PRES WAS LOCATED A THE SRN END OF JAMES BAY WITH A TROUGH
EXTENDING TO THE SW THROUGH ERN LAKE SUPERIOR INTO ERN UPPER MI. AFTER A
BRIEF PERIOD OF MODERATE TO HEAVY SNOW ASSOCIATED WITH LOW LEVEL
CONV AHEAD OF THE TROUGH...WIND PARALLEL SNOW BANDS HAVE DEVELOPED
BUT WITH LESS ORGANIZED CONVECTIVE ELEMENTS. SNOWFALL AMOUNTS WERE
IN THE 1 TO 3 INCH RANGE OVER THE WEST DURING THE EVENING BUT HAVE
ONLY AMOUNTED TO LESS THAN INCH OVER N CNTRL UPPER MI NEAR NEGAUNEE.
WITH LOW LEVEL TEMPS NEAR FREEZING AND MILD AIR MOVING IN FROM THE
RELATIVELY WARM LAKE SUPERIOR...WATER TEMPS IN THE UPPER 40S...WET
BULB ZERO HEIGHTS HAVE REMAINED HIGH ENOUGH FOR THE SNOW TO CHANGE
BACK TO MAINLY RAIN OVER THE KEWEENAW AND ALONG LAKE SUPERIOR TO THE
EAST.
TODAY...EXPECT THE LAKE ENHANCED SNOW BANDS TO CONTINUE AS CAA DROPS
850 MB TEMPS FROM AROUND -7C TO NEAR -9C. HOWEVER...WITH DRIER AIR
MOVING INTO THE REGION AND LOWER INVERSION HEIGHTS IN THE PRESENCE OF
SYNOPTIC SCALE SUBSIDENCE BEHIND THE DEPARTING MID LEVEL LOW...THE
SNOW SHOWER INTENSITY/COVERAGE WILL DIMINISH THIS MORNING LEAVING
JUST SCT LIGHT SNOW/RAIN SHOWERS BY AFTERNOON.
TONIGHT...THE MODELS SUGGEST A WEAK SHORTWAVE TROUGH MAY SLIDE INTO
THE AREA. WITH 850 MB TEMPS REMAINING NEAR -8C...AN INCREASE IN
850-700 MB MOISTURE...AND MORE FAVORABLE LOW LEVEL CONV AS LAND
BREEZES DEVELOP...SNOW SHOWERS ARE EXPECTED TO INCREASE FOR
LOCATIONS FAVORED TY NW TO WNW FLOW. HOWEVER...GIVEN THE MARGINAL
INSTABILITY...ANY ACCUMULATIONS ARE EXPECTED TO REMAIN AT AN INCH OR
LESS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM EDT TUE OCT 22 2013
THE UPPER GREAT LAKES WILL STILL BE UNDER THE WESTERN SIDE OF THE
UPPER TROUGH AT THE START OF THE LONG TERM PERIOD...WHICH WILL
REMAIN IN PLACE THROUGH THURSDAY NIGHT. AT THE SURFACE...A LOW WILL
BE LOCATED TO THE EAST OF JAMES BAY AND HIGH PRESSURE WILL BE
SLIDING SOUTHEAST THROUGH THE NORTHERN PLAINS THROUGH THURSDAY. THIS
WILL ALLOW NORTHWEST FLOW TO BE PERSISTENT ON WEDNESDAY AND
THURSDAY. 850MB TEMPS DURING THIS PERIOD LOOK TO BE HOVERING RIGHT
AROUND -7 TO -8C AND WITH LAKE SUPERIOR TEMPS ON AVERAGE AROUND
8-9C...THERE IS PLENTY OF OVER LAKE INSTABILITY TO SUPPORT LAKE
EFFECT SHOWERS. ON WEDNESDAY MORNING...EXPECT THE WINDS TO BE NW TO
WNW...BEFORE A WEAK SURFACE TROUGH AND SHORTWAVE SWEEPS THROUGH
WEDNESDAY EVENING AND SHIFTS THE DIRECTION TO A MORE
NORTH-NORTHWESTERLY DIRECTION. WILL HAVE THE HIGHEST POPS EAST OF
GRAND MARAIS OVER THE EAST AND ALONG ALL OF THE HIGHER TERRAIN OVER
THE WEST FOR WEDNESDAY...THEN SHIFTING TO MORE TRADITIONAL NW-NNW
FLOW LOCATIONS FOR WEDNESDAY NIGHT (EG ALGER COUNTY OVER THE EAST).
WILL CONTINUE TO SHOW DEFINITE POPS FOR THE FAVORED EASTERN CWA
LOCATIONS SINCE THE MODELS HAVE BEEN CONSISTENT ON THIS IDEA FOR THE
LAST COUPLE OF DAYS. WILL CONTINUE THE HIGH POPS FOR
THURSDAY...ALTHOUGH TEMPS MAY WARM A DEGREE. EVEN WITH THE
LIKELY/DEFINITE POPS FOR WEDNESDAY...DON/T EXPECT THE INTENSITY TO
BE AS STRONG AS LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT WHEN A
QUICK PERIOD OF DEEPER MOISTURE WITH THE SHORTWAVE AND SURFACE
TROUGH MOVES THROUGH. DEEP CLOUD LAYER (10-12KFT) AND LAKE INDUCED
CAPE VALUES OF 300-500 J/KG SUPPORT THE POTENTIAL FOR STRONGER LAKE
EFFECT SNOW BANDS ON WEDNESDAY NIGHT. THIS COULD EVEN END UP
PRODUCING MODERATE TO HEAVY SNOWFALL IN QUICK BURSTS...SIMILAR TO
WHAT WAS SEEN IN PORTIONS OF WESTERN UPPER MICHIGAN THIS
AFTERNOON/EVENING (JACOBSVILLE SAW 2.6IN IN 1HR).
THE MAIN LIMITING FACTORS FOR THIS EVENT WILL BE THE LOWER
SNOW RATIOS AND MID-UPPER 30S NEAR SURFACE TEMPERATURES. CONTINUE TO
THINK SNOW RATIOS WILL BE ON THE LOW END FOR TRADITIONAL LAKE EFFECT
EVENTS...SINCE THE CLOUD LAYER WILL BE AT OR BELOW THE DGZ.
THUS...WITH MUCH OF THE FORCING BELOW...WOULD EXPECT RATIOS TO BE IN
THE 10-13 TO 1 RANGE INSTEAD OF THE NORMAL 17-25 TO 1. IN
ADDITION...WITH UPPER 40 DEGREE WATER MODIFYING THE NEAR SURFACE
AIR...LOCATIONS NEAR LAKE SUPERIOR WILL BE HOVERING IN THE MID TO
EVEN UPPER 30S. THIS WILL TRY TO PUSH WETBULB ZERO VALUES UP TO
1KFT...WHICH WOULD BE ENOUGH FOR SOME MIXING OF RAIN/SNOW NEAR THE
SHORELINE. IN ADDITION...THOSE WARMER SURFACE TEMPERATURES WILL
ATTEMPT TO LIMIT THE SNOWFALL ACCUMULATION EXCEPT UNDER THE STRONGER
BANDS...WHERE THE RATE WILL COMPENSATE FOR THE WARMER TEMPS.
THEREFORE...PINNING DOWN SNOWFALL AMOUNTS WITH THE MULTIPLE FACTORS
IS TRICKY FOR THIS EARLY SEASON EVENT. IN GENERAL...THINK THE
SNOWFALL AMOUNTS DURING THE WEDNESDAY AFTERNOON/NIGHT PERIOD WILL
BE UNDER ADVISORY CRITERIA (GENERALLY 1-3INCH) WITH SOME LOCATIONS
SEEING ADVISORY AMOUNTS (3-4INCH) WHERE ANY STRONGER BANDS SETS UP.
ONE OTHER ITEM TO MENTION FOR THE WEDNESDAY AFTERNOON AND NIGHT
PERIOD IS THE POTENTIAL FOR SOME WATERSPOUTS OVER THE SOUTHEASTERN
PART OF LAKE SUPERIOR. WITH THE CONVECTIVE CLOUD DEPTH OF 10-12KFT
AND DELTA-T VALUES AROUND 16...THAT DOES PLACE THAT AREA ON THE
EDGE OF THE WATERSPOUT POTENTIAL ON THE SZILAGYI WATERSPOUT
NOMOGRAM. THUS...WILL PUT IN A SLIGHT CHANCE MENTION IN THAT AREA
AND THEN END IN BY THURSDAY MORNING SINCE THE MOISTURE DEPTH BEGINS
TO LESSEN.
THE UPPER TROUGH WILL FINALLY BEGIN SHIFTING EAST ON THURSDAY NIGHT
AND A HIGH PRESSURE RIDGE WILL BEGIN TO MOVE EAST INTO THE UPPER
GREAT LAKES. THIS WILL BRING DRIER AIR INTO THE CWA FROM WEST TO
EAST WHILE BACKING THE WINDS TO THE SOUTHWEST. THUS...EXPECT THE
ONGOING LAKE EFFECT PRECIPITATION TO DIMINISH OVER THE WEST AND
THEN SLOWLY DIMINISH AND SHIFT EAST OVER THE EASTERN CWA.
FORTUNATELY...THE MODELS HAVE COME INTO MUCH BETTER AGREEMENT WITH
THE SHORTWAVE ROUNDING THE UPPER RIDGE OVER THE WEST AND SLIDING
SOUTHEAST INTO THE UPPER GREAT LAKES REGION ON FRIDAY NIGHT INTO
SATURDAY. THIS CLIPPER SYSTEM (WITH THE LOW SLIDING ALONG THE
EASTERN SHORE OF LAKE SUPERIOR) SHOULD PRODUCE SOME PRECIPITATION
OVER THE CWA ON FRIDAY NIGHT AND HAVE THE HIGHEST POPS OVER THE
NORTHEAST HALF. THEN AFTER THE COLD FRONT MOVES THROUGH...EXPECT
THERE TO BE A PERIOD OF LAKE ENHANCED RAIN/SNOW IN THE NORTHWEST
WIND FAVORED LOCATIONS AS 850MB TEMPS FALL BACK TO -6C. WILL
HIGHLIGHT THE HIGHEST POPS IN THOSE LOCATIONS FOR SATURDAY AND THEN
GRADUALLY DIMINISH THEM SATURDAY NIGHT INTO SUNDAY...AS THE UPPER
TROUGH SHIFTS EAST AND HIGH PRESSURE MOVES OVER THE CWA. IT LOOKS
LIKE THE SUNDAY INTO SUNDAY NIGHT PERIOD WILL GIVE A LITTLE BIT OF A
REPRIVE TO THE UNSETTLED WEATHER THAT WE WILL SEE THIS WEEK. LATEST
TRENDS IN THE 00Z MODEL RUNS HAVE THE UPPER TROUGH THAT WILL BE
DIGGING OVER THE ROCKIES POTENTIALLY BECOMING CUTOFF OVER THE WEST
COAST. AS THIS OCCURS ON MONDAY...AN ELONGATED TROUGH ASSOCIATED
FROM A LOW IN THE CENTRAL PLAINS WILL SLOWLY MOVE EAST ACROSS THE
AREA. THIS WILL BE SOMETHING TO KEEP AN EYE ON...AS TEMPERATURES
WILL LIKELY BE COLD ENOUGH FOR SNOW ALOFT (ALTHOUGH SURFACE
TEMPERATURES ARE MARGINAL) AND IT COULD PRODUCE MEASURABLE SNOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 746 AM EDT TUE OCT 22 2013
EXPECT MVFR WX TO DOMINATE MOST OF THIS FCST PERIOD WITH COLD NW
FLOW BETWEEN A DEPARTING LOW PRESSURE TROOUGH AND AN INCOMING RIDGE.
THE CLOSER APPROACH OF THE SFC RIDGE AND WEAKER PRES GRADIENT LATER
TODAY WILL ALLOW GUSTY NW WINDS TO DIMINISH. AT SAW LAKE EFFECT SNOW
SHOWERS WILL DIMINISH EARLY TODAY AND THEN VFR WX WILL RETURN THIS
AFTERNOON AS THE RIDGE APPROACHES WHILE LAKE MOISTURE KEEPS MVFR
CIGS AT CMX/IWD WITH PREVAILING NW WINDS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EDT TUE OCT 22 2013
NORTH TO NORTHWEST GALES THIS MORNING ARE EXPECTED TO DIMINISH BY
AFTERNOON AS THE GRADIENT WEAKENS BEHIND A DEPARTING TROUGH.
HOWEVER...WITH PERSISTENT LOW PRES TO THE EAST AND RIDGE OVER THE
NORTHERN PLAINS...WINDS WILL BE LINGER IN THE 20 TO 30KT RANGE
THROUGH THE THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MIZ005.
LAKE SUPERIOR...
GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LSZ264>267.
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
713 AM EDT TUE OCT 22 2013
.AVIATION...
//DISCUSSION...
DRY WESTERLY FLOW SCOURED OUT EVEN THE LAKE EFFECT STRATOCU FROM
LAKE MICHIGAN BEFORE SUNRISE LEAVING CLEAR CONDITIONS TO START THE
DAY. SUNSHINE AND SURFACE HEATING WILL THEN HELP CLOUDS REDEVELOP
DURING THE LATE MORNING WITH A VFR CEILING BACK IN PLACE FOR THE
AFTERNOON. A FAST MOVING LOW PRESSURE SYSTEM WILL ARRIVE FROM THE
CENTRAL PLAINS OVER INDIANA AND OHIO BY LATE AFTERNOON THROUGH
THIS EVENING. THIS SYSTEM COULD PRODUCE LIGHT RAIN IN THE DTW
TERMINAL CORRIDOR THROUGH LATE EVENING BUT NO RESTRICTION IS
EXPECTED OTHER THAN A CEILING BELOW 5000 FEET. BACKING LOW LEVEL
FLOW AFTER MIDNIGHT WILL THEN HELP STRATOCU DIMINISH AGAIN TOWARD
SUNRISE WEDNESDAY OVER ALL TERMINAL SITES.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET AFTER 15Z TUESDAY
WITH HIGHER CONFIDENCE AFTER 00Z.
&&
.PREV DISCUSSION...ISSUED 347 AM EDT TUE OCT 22 2013
SHORT TERM... TODAY AND TONIGHT
CONFLUENT FLOW ALOFT THROUGH THE SOUTH FLANK OF THE UPPER LOW WILL
MAINTAIN THE MID LEVEL DRY SLOT OVER THE SOUTHERN GREAT LAKES FOR
MOST OF TODAY. THIS WILL KEEP THE INFLUENCE OF LAKE MICHIGAN SUBDUED
ON THIS SIDE OF THE STATE, ESPECIALLY IN TERMS OF PRECIPITATION AND
POSSIBLY EVEN CAUSING A DISRUPTION IN THE CLOUD FIELD. TRENDS IN LOW
LEVEL RH PROFILES IN THE NAM AND RAP MODELS INDICATE DRY AIR FROM
THE MIDWEST AS LOW AS 850 MB DURING THE MORNING WHICH COULD LEAD TO
SOME BREAKS IN THE LAKE CLOUD PATTERN OR A TENDENCY FOR THE CLOUDS
TO HUG CLOSER TO THE SHORELINE OVER SW LOWER EARLY IN THE DAY. THE
LATEST SATELLITE IMAGERY SUPPORTS A GENERAL PARTLY SUNNY START TO
THE DAY AND ALLOWS FOR SOME RENEWED STRATOCU FORMATION DUE TO
SURFACE HEATING AND BEFORE HIGH CLOUDS INCREASE WITH THE NEXT SHORT
WAVE LATE IN THE DAY. THE BREAKS OF SUNSHINE WILL HELP MAX TEMPS
RECOVER INTO THE MID AND UPPER 40S.
THE NEXT SHORT WAVE WILL ARRIVE OVER INDIANA FROM THE CENTRAL PLAINS
BY EVENING NEARLY IN PHASE WITH THE SECONDARY SURFACE TROUGH SLIDING
THROUGH THE NORTHERN GREAT LAKES. THE SURFACE TROUGH WILL MOVE
THROUGH SE MICHIGAN DURING THE LATE AFTERNOON AND EVENING WHILE THE
SHORT WAVE APPROACHES THE SOUTHERN MICHIGAN BORDER. THE COMBINATION
OF THESE TWO FEATURES WILL GIVE INSTABILITY OVER LAKE MICHIGAN A
CHANCE TO PERK UP, ALONG WITH BOUNDARY LAYER INSTABILITY DUE TO
SURFACE HEATING, FOR A CHANCE OF LIGHT RAIN SHOWERS DURING THE LATE
AFTERNOON. THE BEST CHANCE OF RAIN WILL BE DURING THE EVENING
GENERALLY SOUTH OF THE I-69 CORRIDOR WHERE THE NORTH FLANK OF THE
SHORT WAVE FORCING WILL INTERACT WITH THE SURFACE TROUGH. THIS
REFLECTS A SOUTHWARD MODEL ADJUSTMENT ON TRACK OF SHORT WAVE WITH
THE MID LEVEL TROWAL AXIS REMAINING SOUTH OF THE STATE LINE. MODEL
DEPICTIONS OF DCVA ARE TOO WEAK TO GO WITH ANYTHING GREATER THAN A
CHANCE POP BEFORE THE SYSTEM EXITS EASTWARD AFTER MIDNIGHT. MOST OF
THE OVERNIGHT HOURS WILL THEN BE DOMINATED BY RENEWED LOW LEVEL COLD
ADVECTION ON NW FLOW. BOTH THICKNESS FIELDS AND MODEL SOUNDINGS
INDICATE PRECIPITATION POTENTIAL ENDED BY THE TIME THE BOUNDARY
LAYER COOLS ENOUGH FOR SNOW, AND AS NORTHWEST FLOW CONFINES LAKE
EFFECT CLOSER TO LAKE MICHIGAN. MIN TEMPS NEAR THE FREEZING MARK
LOOK ON TARGET BY SUNRISE WEDNESDAY.
LONG TERM...
LONGWAVE TROUGHING ANCHORED BY A LARGE CLOSED LOW OVER THE GREAT
LAKES WILL MAINTAIN MOIST CYCLONIC FLOW OVER THE AREA UNTIL THE
DEPARTURE OF THE LOW TO THE NORTHEAST LATE IN THE WEEK. IN THE
MEANTIME, NORTHWEST GRADIENT FLOW AROUND THE EASTERN FLANK OF HIGH
PRESSURE BUILDING INTO THE CENTRAL CONUS WILL KEEP DAYTIME HIGHS IN
THE MID TO UPPER 40S BENEATH H85 TEMPS PROGGED TO HOVER AROUND -5C.
IN GENERAL, NORTHWEST FLOW WILL MINIMIZE CONCERN FOR LAKE EFFECT SHOWERS
TO ADVANCE INTO THE AREA AS CONVECTIVE PLUMES OFF OF LAKE MICHIGAN
WILL TEND TO BE SHUNTED TO OUR SOUTHWEST.
THE EXCEPTION WILL BE WEDNESDAY WHEN THE LOW LEVEL FLOW IS PROGGED
TO BACK TOWARD WESTERLY AHEAD OF AN APPROACHING SHORTWAVE. WITH THE
HELP OF DIURNAL HEATING, A DEEP CONVECTIVE BOUNDARY LAYER WITH
ORIGINS OVER LAKE MICHIGAN STANDS A DECENT CHANCE OF ADVECTING EAST
INTO THE AREA. CHANCE POPS THEREFORE REMAIN IN PLACE FOR WED
AFTERNOON, WITH THE BEST CHANCE FOR SHOWERS SOUTH OF I-69. LOW-LEVEL
FLOW WILL BACK TO A LESSER DEGREE ON WED NIGHT AS A SHEARED H5 PV
ANOMALY TRACKS ACROSS THE MI/OH BORDER. DYNAMIC FORCING ASSOCIATED
WITH THE WAVE ITSELF WARRANTS CHANCE POPS NEAR THE OHIO BORDER, BUT
POTENTIAL WILL BE LIMITED WITH THE DEEPER MOISTURE CONFINED TO THE
OHIO VALLEY.
MOIST CYCLONIC FLOW IN ADDITION TO CONTRIBUTIONS FROM LAKE
SUPERIOR/MICHIGAN WILL ENSURE A SUBSTANTIAL BOUNDARY LAYER
CONTRIBUTION TO A MOSTLY CLOUDY SKY CONDITION THAT IS FORECAST TO
PERSIST THROUGH AT LEAST THURSDAY NIGHT. INHERITED FORECAST LOWS
NEAR 30 FOR MOST AREAS STILL LOOK REASONABLE, BUT ANY POTENTIAL FOR
CLEARING WILL BE WORTH MONITORING AS A FEW HOURS OF GOOD RADIATING
WITHIN THE RESIDENT AIRMASS WOULD SEND TEMPS WELL INTO THE 20S.
SHORTWAVE RIDGING IN ADVANCE OF ANOTHER HIGH-LATITUDE WAVE WILL WORK
INTO THE AREA ON FRIDAY AGAINST A BACKDROP OF LARGER SCALE HEIGHT
RISES OWING TO EASTWARD PROGRESSION OF THE LONGWAVE TROUGH. HIGH
PRESSURE WILL BUILD INTO THE AREA AS A RESULT AND SHOULD HELP BREAK
UP BOUNDARY LAYER CLOUD COVER TO SOME EXTENT, BUT HIGHS WILL AGAIN
REMAIN IN THE 40S WITH THE THERMAL TROUGH PROGGED TO MAINTAIN ITS
GRIP ON THE AREA.
MARINE...
A SECONDARY SURGE OF COLD AIR SPREADING OVER THE GREAT LAKES TODAY
WILL REQUIRE GALE WARNINGS TO CONTINUE OVER NORTHERN AND CENTRAL
LAKE HURON. WARNINGS HAVE BEEN ADDED FOR SAGINAW BAY AS FREQUENT
GUSTS TO 35 KNOTS ARE NOW EXPECTED THERE AS THE WIND FUNNELS DOWN
THE CENTER OF THE BAY. SMALL CRAFT ADVISORIES WILL HOLD ALONG THE
SOUTHERN LAKE HURON NEARSHORE AREAS. THE STRONG WIND WILL KEEP
WATERSPOUT POTENTIAL LOW EVEN AS INSTABILITY INCREASES OVER THE
WATER TODAY WITH A BETTER CHANCE OVER THE OPEN WATERS OF LAKE HURON
TONIGHT AS THE WIND DIMINISHES. WIND SPEED WILL CONTINUE TO DIMINISH
TUESDAY NIGHT INTO WEDNESDAY BUT WILL REMAIN FROM THE NORTHWEST AND
WEST, MAINTAINING BELOW NORMAL TEMPERATURE THROUGH THE END OF THE
WEEK.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
GALE WARNING...LHZ361-LHZ362-LHZ363-LHZ421-LHZ422...UNTIL 8 PM
TUESDAY.
SMALL CRAFT ADVISORY...OUTER SAGINAW BAY...FROM 8 PM TUESDAY TO 8
AM WEDNESDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
SANILAC...UNTIL 8 AM WEDNESDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
SHORT TERM...BT
LONG TERM....JVC
MARINE.......BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
521 AM EDT TUE OCT 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EDT TUE OCT 22 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE INTO THE WRN CONUS AND
A BROAD DOWNSTREAM TROUGH OVER THE CNTRL AND ERN CONUS. A MID LEVEL
LOW JUST NORTH OF THE SAULT WAS LIFTING SLOWLY TO THE ENE. AT THE
SFC...LOW PRES WAS LOCATED A THE SRN END OF JAMES BAY WITH A TROUGH
EXTENDING TO THE SW THROUGH ERN LAKE SUPERIOR INTO ERN UPPER MI. AFTER A
BRIEF PERIOD OF MODERATE TO HEAVY SNOW ASSOCIATED WITH LOW LEVEL
CONV AHEAD OF THE TROUGH...WIND PARALLEL SNOW BANDS HAVE DEVELOPED
BUT WITH LESS ORGANIZED CONVECTIVE ELEMENTS. SNOWFALL AMOUNTS WERE
IN THE 1 TO 3 INCH RANGE OVER THE WEST DURING THE EVENING BUT HAVE
ONLY AMOUNTED TO LESS THAN INCH OVER N CNTRL UPPER MI NEAR NEGAUNEE.
WITH LOW LEVEL TEMPS NEAR FREEZING AND MILD AIR MOVING IN FROM THE
RELATIVELY WARM LAKE SUPERIOR...WATER TEMPS IN THE UPPER 40S...WET
BULB ZERO HEIGHTS HAVE REMAINED HIGH ENOUGH FOR THE SNOW TO CHANGE
BACK TO MAINLY RAIN OVER THE KEWEENAW AND ALONG LAKE SUPERIOR TO THE
EAST.
TODAY...EXPECT THE LAKE ENHANCED SNOW BANDS TO CONTINUE AS CAA DROPS
850 MB TEMPS FROM AROUND -7C TO NEAR -9C. HOWEVER...WITH DRIER AIR
MOVING INTO THE REGION AND LOWER INVERSION HEIGHTS IN THE PRESENCE OF
SYNOPTIC SCALE SUBSIDENCE BEHIND THE DEPARTING MID LEVEL LOW...THE
SNOW SHOWER INTENSITY/COVERAGE WILL DIMINISH THIS MORNING LEAVING
JUST SCT LIGHT SNOW/RAIN SHOWERS BY AFTERNOON.
TONIGHT...THE MODELS SUGGEST A WEAK SHORTWAVE TROUGH MAY SLIDE INTO
THE AREA. WITH 850 MB TEMPS REMAINING NEAR -8C...AN INCREASE IN
850-700 MB MOISTURE...AND MORE FAVORABLE LOW LEVEL CONV AS LAND
BREEZES DEVELOP...SNOW SHOWERS ARE EXPECTED TO INCREASE FOR
LOCATIONS FAVORED TY NW TO WNW FLOW. HOWEVER...GIVEN THE MARGINAL
INSTABILITY...ANY ACCUMULATIONS ARE EXPECTED TO REMAIN AT AN INCH OR
LESS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM EDT TUE OCT 22 2013
THE UPPER GREAT LAKES WILL STILL BE UNDER THE WESTERN SIDE OF THE
UPPER TROUGH AT THE START OF THE LONG TERM PERIOD...WHICH WILL
REMAIN IN PLACE THROUGH THURSDAY NIGHT. AT THE SURFACE...A LOW WILL
BE LOCATED TO THE EAST OF JAMES BAY AND HIGH PRESSURE WILL BE
SLIDING SOUTHEAST THROUGH THE NORTHERN PLAINS THROUGH THURSDAY. THIS
WILL ALLOW NORTHWEST FLOW TO BE PERSISTENT ON WEDNESDAY AND
THURSDAY. 850MB TEMPS DURING THIS PERIOD LOOK TO BE HOVERING RIGHT
AROUND -7 TO -8C AND WITH LAKE SUPERIOR TEMPS ON AVERAGE AROUND
8-9C...THERE IS PLENTY OF OVER LAKE INSTABILITY TO SUPPORT LAKE
EFFECT SHOWERS. ON WEDNESDAY MORNING...EXPECT THE WINDS TO BE NW TO
WNW...BEFORE A WEAK SURFACE TROUGH AND SHORTWAVE SWEEPS THROUGH
WEDNESDAY EVENING AND SHIFTS THE DIRECTION TO A MORE
NORTH-NORTHWESTERLY DIRECTION. WILL HAVE THE HIGHEST POPS EAST OF
GRAND MARAIS OVER THE EAST AND ALONG ALL OF THE HIGHER TERRAIN OVER
THE WEST FOR WEDNESDAY...THEN SHIFTING TO MORE TRADITIONAL NW-NNW
FLOW LOCATIONS FOR WEDNESDAY NIGHT (EG ALGER COUNTY OVER THE EAST).
WILL CONTINUE TO SHOW DEFINITE POPS FOR THE FAVORED EASTERN CWA
LOCATIONS SINCE THE MODELS HAVE BEEN CONSISTENT ON THIS IDEA FOR THE
LAST COUPLE OF DAYS. WILL CONTINUE THE HIGH POPS FOR
THURSDAY...ALTHOUGH TEMPS MAY WARM A DEGREE. EVEN WITH THE
LIKELY/DEFINITE POPS FOR WEDNESDAY...DON/T EXPECT THE INTENSITY TO
BE AS STRONG AS LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT WHEN A
QUICK PERIOD OF DEEPER MOISTURE WITH THE SHORTWAVE AND SURFACE
TROUGH MOVES THROUGH. DEEP CLOUD LAYER (10-12KFT) AND LAKE INDUCED
CAPE VALUES OF 300-500 J/KG SUPPORT THE POTENTIAL FOR STRONGER LAKE
EFFECT SNOW BANDS ON WEDNESDAY NIGHT. THIS COULD EVEN END UP
PRODUCING MODERATE TO HEAVY SNOWFALL IN QUICK BURSTS...SIMILAR TO
WHAT WAS SEEN IN PORTIONS OF WESTERN UPPER MICHIGAN THIS
AFTERNOON/EVENING (JACOBSVILLE SAW 2.6IN IN 1HR).
THE MAIN LIMITING FACTORS FOR THIS EVENT WILL BE THE LOWER
SNOW RATIOS AND MID-UPPER 30S NEAR SURFACE TEMPERATURES. CONTINUE TO
THINK SNOW RATIOS WILL BE ON THE LOW END FOR TRADITIONAL LAKE EFFECT
EVENTS...SINCE THE CLOUD LAYER WILL BE AT OR BELOW THE DGZ.
THUS...WITH MUCH OF THE FORCING BELOW...WOULD EXPECT RATIOS TO BE IN
THE 10-13 TO 1 RANGE INSTEAD OF THE NORMAL 17-25 TO 1. IN
ADDITION...WITH UPPER 40 DEGREE WATER MODIFYING THE NEAR SURFACE
AIR...LOCATIONS NEAR LAKE SUPERIOR WILL BE HOVERING IN THE MID TO
EVEN UPPER 30S. THIS WILL TRY TO PUSH WETBULB ZERO VALUES UP TO
1KFT...WHICH WOULD BE ENOUGH FOR SOME MIXING OF RAIN/SNOW NEAR THE
SHORELINE. IN ADDITION...THOSE WARMER SURFACE TEMPERATURES WILL
ATTEMPT TO LIMIT THE SNOWFALL ACCUMULATION EXCEPT UNDER THE STRONGER
BANDS...WHERE THE RATE WILL COMPENSATE FOR THE WARMER TEMPS.
THEREFORE...PINNING DOWN SNOWFALL AMOUNTS WITH THE MULTIPLE FACTORS
IS TRICKY FOR THIS EARLY SEASON EVENT. IN GENERAL...THINK THE
SNOWFALL AMOUNTS DURING THE WEDNESDAY AFTERNOON/NIGHT PERIOD WILL
BE UNDER ADVISORY CRITERIA (GENERALLY 1-3INCH) WITH SOME LOCATIONS
SEEING ADVISORY AMOUNTS (3-4INCH) WHERE ANY STRONGER BANDS SETS UP.
ONE OTHER ITEM TO MENTION FOR THE WEDNESDAY AFTERNOON AND NIGHT
PERIOD IS THE POTENTIAL FOR SOME WATERSPOUTS OVER THE SOUTHEASTERN
PART OF LAKE SUPERIOR. WITH THE CONVECTIVE CLOUD DEPTH OF 10-12KFT
AND DELTA-T VALUES AROUND 16...THAT DOES PLACE THAT AREA ON THE
EDGE OF THE WATERSPOUT POTENTIAL ON THE SZILAGYI WATERSPOUT
NOMOGRAM. THUS...WILL PUT IN A SLIGHT CHANCE MENTION IN THAT AREA
AND THEN END IN BY THURSDAY MORNING SINCE THE MOISTURE DEPTH BEGINS
TO LESSEN.
THE UPPER TROUGH WILL FINALLY BEGIN SHIFTING EAST ON THURSDAY NIGHT
AND A HIGH PRESSURE RIDGE WILL BEGIN TO MOVE EAST INTO THE UPPER
GREAT LAKES. THIS WILL BRING DRIER AIR INTO THE CWA FROM WEST TO
EAST WHILE BACKING THE WINDS TO THE SOUTHWEST. THUS...EXPECT THE
ONGOING LAKE EFFECT PRECIPITATION TO DIMINISH OVER THE WEST AND
THEN SLOWLY DIMINISH AND SHIFT EAST OVER THE EASTERN CWA.
FORTUNATELY...THE MODELS HAVE COME INTO MUCH BETTER AGREEMENT WITH
THE SHORTWAVE ROUNDING THE UPPER RIDGE OVER THE WEST AND SLIDING
SOUTHEAST INTO THE UPPER GREAT LAKES REGION ON FRIDAY NIGHT INTO
SATURDAY. THIS CLIPPER SYSTEM (WITH THE LOW SLIDING ALONG THE
EASTERN SHORE OF LAKE SUPERIOR) SHOULD PRODUCE SOME PRECIPITATION
OVER THE CWA ON FRIDAY NIGHT AND HAVE THE HIGHEST POPS OVER THE
NORTHEAST HALF. THEN AFTER THE COLD FRONT MOVES THROUGH...EXPECT
THERE TO BE A PERIOD OF LAKE ENHANCED RAIN/SNOW IN THE NORTHWEST
WIND FAVORED LOCATIONS AS 850MB TEMPS FALL BACK TO -6C. WILL
HIGHLIGHT THE HIGHEST POPS IN THOSE LOCATIONS FOR SATURDAY AND THEN
GRADUALLY DIMINISH THEM SATURDAY NIGHT INTO SUNDAY...AS THE UPPER
TROUGH SHIFTS EAST AND HIGH PRESSURE MOVES OVER THE CWA. IT LOOKS
LIKE THE SUNDAY INTO SUNDAY NIGHT PERIOD WILL GIVE A LITTLE BIT OF A
REPRIVE TO THE UNSETTLED WEATHER THAT WE WILL SEE THIS WEEK. LATEST
TRENDS IN THE 00Z MODEL RUNS HAVE THE UPPER TROUGH THAT WILL BE
DIGGING OVER THE ROCKIES POTENTIALLY BECOMING CUTOFF OVER THE WEST
COAST. AS THIS OCCURS ON MONDAY...AN ELONGATED TROUGH ASSOCIATED
FROM A LOW IN THE CENTRAL PLAINS WILL SLOWLY MOVE EAST ACROSS THE
AREA. THIS WILL BE SOMETHING TO KEEP AN EYE ON...AS TEMPERATURES
WILL LIKELY BE COLD ENOUGH FOR SNOW ALOFT (ALTHOUGH SURFACE
TEMPERATURES ARE MARGINAL) AND IT COULD PRODUCE MEASURABLE SNOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 123 AM EDT TUE OCT 22 2013
ALTHOUGH THERE MAY BE SOME IFR CONDITIONS AT IWD/CMX EARLY THIS MRNG
WITH UPSLOPE GUSTY NW FLOW IN THE WAKE OF TROF PASSAGE...EXPECT MVFR
WX TO DOMINATE MOST OF THIS FCST PERIOD WITH CHILLY NW FLOW BTWN
DEPARTING LO PRES TROF AND INCOMING HI PRES RDG. CLOSER APRCH OF THE
SFC RDG/WEAKER PRES GRADIENT LATER TODAY WL ALLOW GUSTY NW WINDS TO
DIMINISH. AT SAW...VFR CONDITIONS EARLY WL GIVE WAY TO A PERIOD OF
MVFR CIGS WITH ARRIVAL OF DEEPER MSTR ACCOMPANYING THE TROF...BUT
VFR WX WL RETURN THIS AFTN WITH CLOSER APRCH OF RDG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EDT TUE OCT 22 2013
NORTH TO NORTHWEST GALES THIS MORNING ARE EXPECTED TO DIMINISH BY
AFTERNOON AS THE GRADIENT WEAKENS BEHIND A DEPARTING TROUGH.
HOWEVER...WITH PERSISTENT LOW PRES TO THE EAST AND RIDGE OVER THE
NORTHERN PLAINS...WINDS WILL BE LINGER IN THE 20 TO 30KT RANGE
THROUGH THE THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MIZ005.
LAKE SUPERIOR...
GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LSZ264>267.
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
347 AM EDT TUE OCT 22 2013
.SHORT TERM... TODAY AND TONIGHT
CONFLUENT FLOW ALOFT THROUGH THE SOUTH FLANK OF THE UPPER LOW WILL
MAINTAIN THE MID LEVEL DRY SLOT OVER THE SOUTHERN GREAT LAKES FOR
MOST OF TODAY. THIS WILL KEEP THE INFLUENCE OF LAKE MICHIGAN SUBDUED
ON THIS SIDE OF THE STATE, ESPECIALLY IN TERMS OF PRECIPITATION AND
POSSIBLY EVEN CAUSING A DISRUPTION IN THE CLOUD FIELD. TRENDS IN LOW
LEVEL RH PROFILES IN THE NAM AND RAP MODELS INDICATE DRY AIR FROM
THE MIDWEST AS LOW AS 850 MB DURING THE MORNING WHICH COULD LEAD TO
SOME BREAKS IN THE LAKE CLOUD PATTERN OR A TENDENCY FOR THE CLOUDS
TO HUG CLOSER TO THE SHORELINE OVER SW LOWER EARLY IN THE DAY. THE
LATEST SATELLITE IMAGERY SUPPORTS A GENERAL PARTLY SUNNY START TO
THE DAY AND ALLOWS FOR SOME RENEWED STRATOCU FORMATION DUE TO
SURFACE HEATING AND BEFORE HIGH CLOUDS INCREASE WITH THE NEXT SHORT
WAVE LATE IN THE DAY. THE BREAKS OF SUNSHINE WILL HELP MAX TEMPS
RECOVER INTO THE MID AND UPPER 40S.
THE NEXT SHORT WAVE WILL ARRIVE OVER INDIANA FROM THE CENTRAL PLAINS
BY EVENING NEARLY IN PHASE WITH THE SECONDARY SURFACE TROUGH SLIDING
THROUGH THE NORTHERN GREAT LAKES. THE SURFACE TROUGH WILL MOVE
THROUGH SE MICHIGAN DURING THE LATE AFTERNOON AND EVENING WHILE THE
SHORT WAVE APPROACHES THE SOUTHERN MICHIGAN BORDER. THE COMBINATION
OF THESE TWO FEATURES WILL GIVE INSTABILITY OVER LAKE MICHIGAN A
CHANCE TO PERK UP, ALONG WITH BOUNDARY LAYER INSTABILITY DUE TO
SURFACE HEATING, FOR A CHANCE OF LIGHT RAIN SHOWERS DURING THE LATE
AFTERNOON. THE BEST CHANCE OF RAIN WILL BE DURING THE EVENING
GENERALLY SOUTH OF THE I-69 CORRIDOR WHERE THE NORTH FLANK OF THE
SHORT WAVE FORCING WILL INTERACT WITH THE SURFACE TROUGH. THIS
REFLECTS A SOUTHWARD MODEL ADJUSTMENT ON TRACK OF SHORT WAVE WITH
THE MID LEVEL TROWAL AXIS REMAINING SOUTH OF THE STATE LINE. MODEL
DEPICTIONS OF DCVA ARE TOO WEAK TO GO WITH ANYTHING GREATER THAN A
CHANCE POP BEFORE THE SYSTEM EXITS EASTWARD AFTER MIDNIGHT. MOST OF
THE OVERNIGHT HOURS WILL THEN BE DOMINATED BY RENEWED LOW LEVEL COLD
ADVECTION ON NW FLOW. BOTH THICKNESS FIELDS AND MODEL SOUNDINGS
INDICATE PRECIPITATION POTENTIAL ENDED BY THE TIME THE BOUNDARY
LAYER COOLS ENOUGH FOR SNOW, AND AS NORTHWEST FLOW CONFINES LAKE
EFFECT CLOSER TO LAKE MICHIGAN. MIN TEMPS NEAR THE FREEZING MARK
LOOK ON TARGET BY SUNRISE WEDNESDAY.
&&
.LONG TERM...
LONGWAVE TROUGHING ANCHORED BY A LARGE CLOSED LOW OVER THE GREAT
LAKES WILL MAINTAIN MOIST CYCLONIC FLOW OVER THE AREA UNTIL THE
DEPARTURE OF THE LOW TO THE NORTHEAST LATE IN THE WEEK. IN THE
MEANTIME, NORTHWEST GRADIENT FLOW AROUND THE EASTERN FLANK OF HIGH
PRESSURE BUILDING INTO THE CENTRAL CONUS WILL KEEP DAYTIME HIGHS IN
THE MID TO UPPER 40S BENEATH H85 TEMPS PROGGED TO HOVER AROUND -5C.
IN GENERAL, NORTHWEST FLOW WILL MINIMIZE CONCERN FOR LAKE EFFECT SHOWERS
TO ADVANCE INTO THE AREA AS CONVECTIVE PLUMES OFF OF LAKE MICHIGAN
WILL TEND TO BE SHUNTED TO OUR SOUTHWEST.
THE EXCEPTION WILL BE WEDNESDAY WHEN THE LOW LEVEL FLOW IS PROGGED
TO BACK TOWARD WESTERLY AHEAD OF AN APPROACHING SHORTWAVE. WITH THE
HELP OF DIURNAL HEATING, A DEEP CONVECTIVE BOUNDARY LAYER WITH
ORIGINS OVER LAKE MICHIGAN STANDS A DECENT CHANCE OF ADVECTING EAST
INTO THE AREA. CHANCE POPS THEREFORE REMAIN IN PLACE FOR WED
AFTERNOON, WITH THE BEST CHANCE FOR SHOWERS SOUTH OF I-69. LOW-LEVEL
FLOW WILL BACK TO A LESSER DEGREE ON WED NIGHT AS A SHEARED H5 PV
ANOMALY TRACKS ACROSS THE MI/OH BORDER. DYNAMIC FORCING ASSOCIATED
WITH THE WAVE ITSELF WARRANTS CHANCE POPS NEAR THE OHIO BORDER, BUT
POTENTIAL WILL BE LIMITED WITH THE DEEPER MOISTURE CONFINED TO THE
OHIO VALLEY.
MOIST CYCLONIC FLOW IN ADDITION TO CONTRIBUTIONS FROM LAKE
SUPERIOR/MICHIGAN WILL ENSURE A SUBSTANTIAL BOUNDARY LAYER
CONTRIBUTION TO A MOSTLY CLOUDY SKY CONDITION THAT IS FORECAST TO
PERSIST THROUGH AT LEAST THURSDAY NIGHT. INHERITED FORECAST LOWS
NEAR 30 FOR MOST AREAS STILL LOOK REASONABLE, BUT ANY POTENTIAL FOR
CLEARING WILL BE WORTH MONITORING AS A FEW HOURS OF GOOD RADIATING
WITHIN THE RESIDENT AIRMASS WOULD SEND TEMPS WELL INTO THE 20S.
SHORTWAVE RIDGING IN ADVANCE OF ANOTHER HIGH-LATITUDE WAVE WILL WORK
INTO THE AREA ON FRIDAY AGAINST A BACKDROP OF LARGER SCALE HEIGHT
RISES OWING TO EASTWARD PROGRESSION OF THE LONGWAVE TROUGH. HIGH
PRESSURE WILL BUILD INTO THE AREA AS A RESULT AND SHOULD HELP BREAK
UP BOUNDARY LAYER CLOUD COVER TO SOME EXTENT, BUT HIGHS WILL AGAIN
REMAIN IN THE 40S WITH THE THERMAL TROUGH PROGGED TO MAINTAIN ITS
GRIP ON THE AREA.
&&
.MARINE...
A SECONDARY SURGE OF COLD AIR SPREADING OVER THE GREAT LAKES TODAY
WILL REQUIRE GALE WARNINGS TO CONTINUE OVER NORTHERN AND CENTRAL
LAKE HURON. WARNINGS HAVE BEEN ADDED FOR SAGINAW BAY AS FREQUENT
GUSTS TO 35 KNOTS ARE NOW EXPECTED THERE AS THE WIND FUNNELS DOWN
THE CENTER OF THE BAY. SMALL CRAFT ADVISORIES WILL HOLD ALONG THE
SOUTHERN LAKE HURON NEARSHORE AREAS. THE STRONG WIND WILL KEEP
WATERSPOUT POTENTIAL LOW EVEN AS INSTABILITY INCREASES OVER THE
WATER TODAY WITH A BETTER CHANCE OVER THE OPEN WATERS OF LAKE HURON
TONIGHT AS THE WIND DIMINISHES. WIND SPEED WILL CONTINUE TO DIMINISH
TUESDAY NIGHT INTO WEDNESDAY BUT WILL REMAIN FROM THE NORTHWEST AND
WEST, MAINTAINING BELOW NORMAL TEMPERATURE THROUGH THE END OF THE
WEEK.
&&
.AVIATION...ISSUED 1152 PM EDT MON OCT 21 2013
//DISCUSSION...
LAKE EFFECT STRATUS WILL BE THE PREDOMINANT CHALLENGE THIS FORECAST
AS THE SEASON GETS OFF TO A BIT OF AN EARLY START AS COLD...WESTERLY
FLOW BECOMES ESTABLISHED AROUND BASE OF EXPANSIVE UPPER TROUGH OVER
THE AREA. THE LOW LEVEL FLOW WILL BE SOUTHWEST OVERNIGHT IN ADVANCE
OF NEXT EMBEDDED SHORTWAVE TROUGH...WHICH WILL TEND TO FOCUS CIGS
FROM PTK NORTH WITH SCT STRATUS MUCH OF THE TIME YIP/DTW/DET. WITH
FLOW VEERING TO WEST AND THEN NORTHWEST TUESDAY INTO TUESDAY EVENING
WITH THE PASSAGE OF THIS SURFACE TROUGH...MVFR/LOWER VFR CIGS WILL
EXPAND BACK SOUTH TO COVER ALL TERMINALS.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILINGS AOB 5000 FEET AFTER 15Z TUESDAY WITH
HIGHER CONFIDENCE AFTER 00Z.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
GALE WARNING...LHZ361-LHZ362-LHZ363-LHZ421-LHZ422...UNTIL 8 PM
TUESDAY.
SMALL CRAFT ADVISORY...OUTER SAGINAW BAY...FROM 8 PM TUESDAY TO 8
AM WEDNESDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
SANILAC...UNTIL 8 AM WEDNESDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...BT
LONG TERM....JVC
MARINE.......BT
AVIATION.....DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
110 PM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT TUE OCT 22 2013
LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOW THE
UPPER LOW WHICH BROUGHT MUCH COLDER TEMPERATURES TO THE AREA
BEING SHUNTED INTO EASTERN ONTARIO AS A FEW REINFORCING SHORTWAVES
DROP SOUTHEAST THROUGH CENTRAL CANADA INTO THE HIGH PLAINS. THE
MAIN SHORTWAVE OF INTEREST FOR THE SHORT TERM CAN BE SEEN OVER
EASTERN SOUTH DAKOTA... AND IS HELPING TO GENERATE THE LIGHT PCPN
SEEN ON RADAR AND SURFACE OBS OVER FAR SOUTHWEST MINNESOTA...
EASTERN SOUTH DAKOTA... AND NORTHERN IOWA. MOST OF THIS ACTIVITY
LOOKS LIKE IT WILL REMAIN SOUTH OF OUR AREA THIS MORNING... SO
MAINLY JUST MENTIONED SOME FLURRIES OR LOW POPS WITH NO SNOWFALL
ACCUMULATIONS. OTHERWISE... TODAY LOOKS BENIGN ACROSS THE FORECAST
AREA... WITH SOME PEAKS OF SUN INTERSPERSED WITH LINGERING
STRATOCU. WE MAINTAIN SOMEWHAT OF A 925-850MB THERMAL TROUGH OVER
THE AREA TODAY... WHICH SHOULD KEEP PLENTY OF CLOUDS IN PLACE...
AND LATEST 11-3.9 MICRON IMAGERY SHOWS PLENTY OF CLOUDS TO THE
NORTH DROPPING SOUTH WITH TIME. HOWEVER... THERE ARE INDICATIONS
THAT THE BOUNDARY LAYER FLOW WILL BECOME MORE ANTICYCLONIC THIS
AFTERNOON... WHICH COULD WORK TO GENERATE SOME DECENT BREAKS IN
THE CLOUD COVER. PLAYED THINGS MORE PESSIMISTICALLY FOR NOW GIVEN
SATELLITE TRENDS AND FORECAST PROFILES... AND WENT WITH MOSTLY
CLOUDY SKIES FOR MUCH OF THE DAY INTO TONIGHT. THE NEXT SHORTWAVE
OF INTEREST WILL TAKE A VERY SIMILAR TRACK AS THIS MORNING/S...
AND LOOKS TO DROP BY TO OUR SOUTHWEST VERY LATE TONIGHT INTO
WEDNESDAY. AT THIS POINT... IT LOOKS LIKE ANY CHANCE FOR PCPN WILL
ONCE AGAIN BE CONFINED TO THE FAR SOUTHWEST/SOUTH... AND WILL
MAINLY BE ON WEDNESDAY. HOWEVER... DID INCLUDE SOME LOW POPS OVER
THE SOUTHWEST FOR VERY LATE TONIGHT AS SOME ISENTROPIC LIFT AND
FRONTOGENESIS START TO IMPINGE ON THE AREA. DID NOT MAKE ANY
SUBSTANTIVE CHANGES TO THE GOING TEMPERATURE FORECASTS... WHICH
WILL ONCE AGAIN BE QUITE A BIT BELOW NORMAL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 315 AM CDT TUE OCT 22 2013
EARLY MORNING WATER VAPOR IMAGERY WITH 500MB HEIGHTS AND WINDS
IDENTIFIED THE BROAD UPPER LEVEL RIDGE ORIENTED ALONG THE WEST
COAST OF NORTH AMERICA...WITH A DEEP TROUGH OVER THE GREAT LAKES
REGION. THE PV ANOMALY ASSOCIATED WITH THIS VORT MAX WILL DEVELOP
A CYCLONE ALONG THE EASTERN SHORE OF JAMES BAY...AND ANOMALOUSLY
COLD AIR WILL CONTINUE TO BE DRIVEN SOUTH ACROSS THE UPPER MIDWEST
FOR THE NEXT COUPLE OF DAYS.
MEANWHILE A TROPICAL PLUME OF MOISTURE ORIGINATING OVER SOUTHERN
MEXICO WAS STREAMING NORTHEASTWARD ACROSS THE EASTERN SEABOARD. BY
THURSDAY THIS SUBTROPICAL JET WILL PHASE WITH THE NORTHERN
STREAM TROUGH AND BOMB OUT A SUB 960MB SURFACE CYCLONE OFF THE
COAST OF NEWFOUNDLAND. THIS POWERFUL CYCLONE WILL CAUSE THE
NORTHERLY WINDS CURRENTLY IN PLACE ACROSS THE REGION TO BECOME
MORE WESTERLY BY THE END OF THE WEEK. FARTHER UPSTREAM SUBSIDENCE
WILL LEAD LEE SIDE WARMING ON THE FOOTHILLS OF THE ROCKIES...AND
THIS WARM AIR WILL MOVE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY
BY FRIDAY. IN FACT...THE 22.00 GEM/GFS/ECMWF ARE IN GOOD AGREEMENT
THAT THE SATURDAY 00Z RAB AT MSP SHOULD MEASURE ABOVE 0C AT H850.
NOT EXACTLY A HEAT WAVE...BUT SLIGHTLY MORE MILD NONE THE LESS.
THIS WARM UP WILL BE SHORT LIVED AS ANOTHER SHORTWAVE DRIVING THIS
LOW LEVEL WARM AIR ADVECTION WILL CAUSE A CYCLONE TO TRACK ACROSS
SOUTHERN CANADA...AND DRIVE A WEAK COLD FRONT THROUGH THE REGION.
THIS FRONTAL BOUNDARY WILL EVENTUALLY BECOME ORIENTED
EAST/WEST...AND SET THE STAGE FOR A POTENTIALLY SIGNIFICANT STORM
SYSTEM TO DEVELOP NEXT WEEK OVER THE MIDWEST.
IN SUMMARY...A FEW WEAK WAVED EMBEDDED IN NORTHWEST FLOW WILL KEEP
MID LEVEL CLOUDS IN TACT FOR MOST OF THIS WEEK...BUT NOTHING TO
MERIT HAVING ANY POPS IN THE FORECAST. TEMPERATURES WILL MODERATE
SLIGHTLY BY THE WEEKEND...BUT SHOULD STILL REMAIN BELOW
CLIMATOLOGY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1250 PM CDT TUE OCT 22 2013
STRATOCU CLOUDS CONTINUE TO PLAGUE THE TAF SITES WITH CEILINGS
BETWEEN UPPER-END MVFR AND MINIMAL VFR RANGES. CIGS EXPECTED TO
GRADUALLY LIFT WITH COVERAGE SLOWLY BECOMING SCATTERED TO BROKEN
IN THE LOWEST LAYER WHILE HIGHER CEILINGS REMAIN. STILL SOME
UNCERTAINTY AS TO HOW LONG SOME OF THE LOWER LAYERS/CEILINGS WILL
LINGER BUT SHORT-TERM MODELS PLUS OBSERVATION TRENDING PUTS THE
LOWER CLOUDS IN PLACE THRU MUCH OF THE AFTN BEFORE LIFTING THIS
EVE. MIDLVL CIGS WILL HOLD TNGT THRU TMRW IN THIS PERSISTENT NW
FLOW ALOFT. NO PRECIP EXPECTED AT ANY OF THE TAF SITES...THOUGH
KRWF MAY AGAIN BE SUBJECT SO SOME FLURRIES OR -SHSN BUT CHCS ARE
LOW. WINDS WILL REMAIN NW IN THE 5-10 KT RANGE.
KMSP...CEILINGS TO BOUNCE AROUND THE 3 KFT VFR/MVFR THRESHOLD FOR
A COUPLE OF HOURS OR SO AFTER 22/18Z...BUT WILL EVENTUALLY LIFT
INTO VFR BY LATE AFTN AND REMAIN AS SUCH THROUGHOUT THE REST OF
THIS TAF ISSUANCE. CEILINGS WILL REMAIN ABOVE 1700 FT...SO NO
SIGNIFICANT IMPACTS EXPECTED WITH ADVERTISED CEILINGS. WINDS
STARTING OUT FROM 350 DIRECTION WILL BACK TO 300-320 THIS EVE THRU
TMRW AFTN WITH SPEEDS IN THE 5-10 KT RANGE.
/OUTLOOK FOR KMSP/
THU...VFR. NW WIND 10KT.
THU NIGHT...VFR. NW WIND 10 KT BECMG W.
FRI...VFR. W WIND 5-10 KT BECMG SW 15-20 KT.
FRI NIGHT...MVFR CIGS PSBL LATE. SW WIND 10-20 KT BECMG W.
SAT...MVFR CIGS PSBL EARLY. NW WIND 15-20 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...
SHORT TERM...
LONG TERM...JRB
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
611 AM CDT TUE OCT 22 2013
.UPDATE...
ISSUED AT 611 AM CDT TUE OCT 22 2013
UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT TUE OCT 22 2013
LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOW THE UPPER
LOW WHICH BROUGHT MUCH COLDER TEMPERATURES TO THE AREA BEING SHUNTED
INTO EASTERN ONTARIO AS A FEW REINFORCING SHORTWAVES DROP SOUTHEAST
THROUGH CENTRAL CANADA INTO THE HIGH PLAINS. THE MAIN SHORTWAVE OF
INTEREST FOR THE SHORT TERM CAN BE SEEN OVER EASTERN SOUTH DAKOTA...
AND IS HELPING TO GENERATE THE LIGHT PCPN SEEN ON RADAR AND SURFACE
OBS OVER FAR SOUTHWEST MINNESOTA... EASTERN SOUTH DAKOTA... AND
NORTHERN IOWA. MOST OF THIS ACTIVITY LOOKS LIKE IT WILL REMAIN SOUTH
OF OUR AREA THIS MORNING... SO MAINLY JUST MENTIONED SOME FLURRIES
OR LOW POPS WITH NO SNOWFALL ACCUMULATIONS. OTHERWISE... TODAY LOOKS
BENIGN ACROSS THE FORECAST AREA... WITH SOME PEAKS OF SUN
INTERSPERSED WITH LINGERING STRATOCU. WE MAINTAIN SOMEWHAT OF A
925-850MB THERMAL TROUGH OVER THE AREA TODAY... WHICH SHOULD KEEP
PLENTY OF CLOUDS IN PLACE... AND LATEST 11-3.9 MICRON IMAGERY SHOWS
PLENTY OF CLOUDS TO THE NORTH DROPPING SOUTH WITH TIME. HOWEVER...
THERE ARE INDICATIONS THAT THE BOUNDARY LAYER FLOW WILL BECOME MORE
ANTICYCLONIC THIS AFTERNOON... WHICH COULD WORK TO GENERATE SOME
DECENT BREAKS IN THE CLOUD COVER. PLAYED THINGS MORE PESSIMISTICALLY
FOR NOW GIVEN SATELLITE TRENDS AND FORECAST PROFILES... AND WENT
WITH MOSTLY CLOUDY SKIES FOR MUCH OF THE DAY INTO TONIGHT. THE NEXT
SHORTWAVE OF INTEREST WILL TAKE A VERY SIMILAR TRACK AS THIS
MORNING/S... AND LOOKS TO DROP BY TO OUR SOUTHWEST VERY LATE TONIGHT
INTO WEDNESDAY. AT THIS POINT... IT LOOKS LIKE ANY CHANCE FOR PCPN
WILL ONCE AGAIN BE CONFINED TO THE FAR SOUTHWEST/SOUTH... AND WILL
MAINLY BE ON WEDNESDAY. HOWEVER... DID INCLUDE SOME LOW POPS OVER
THE SOUTHWEST FOR VERY LATE TONIGHT AS SOME ISENTROPIC LIFT AND
FRONTOGENESIS START TO IMPINGE ON THE AREA. DID NOT MAKE ANY
SUBSTANTIVE CHANGES TO THE GOING TEMPERATURE FORECASTS... WHICH WILL
ONCE AGAIN BE QUITE A BIT BELOW NORMAL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 315 AM CDT TUE OCT 22 2013
EARLY MORNING WATER VAPOR IMAGERY WITH 500MB HEIGHTS AND WINDS
IDENTIFIED THE BROAD UPPER LEVEL RIDGE ORIENTED ALONG THE WEST COAST
OF NORTH AMERICA...WITH A DEEP TROUGH OVER THE GREAT LAKES REGION.
THE PV ANOMALY ASSOCIATED WITH THIS VORT MAX WILL DEVELOP A CYCLONE
ALONG THE EASTERN SHORE OF JAMES BAY...AND ANOMALOUSLY COLD AIR WILL
CONTINUE TO BE DRIVEN SOUTH ACROSS THE UPPER MIDWEST FOR THE NEXT
COUPLE OF DAYS.
MEANWHILE A TROPICAL PLUME OF MOISTURE ORIGINATING OVER SOUTHERN
MEXICO WAS STREAMING NORTHEASTWARD ACROSS THE EASTERN SEABOARD. BY
THURSDAY THIS SUBTROPICAL JET WILL PHASE WITH THE NORTHERN STREAM
TROUGH AND BOMB OUT A SUB 960MB SURFACE CYCLONE OFF THE COAST OF NEW
FOUNDLAND. THIS POWERFUL CYCLONE WILL CAUSE THE NORTHERLY WINDS
CURRENTLY IN PLACE ACROSS THE REGION TO BECOME MORE WESTERLY BY THE
END OF THE WEEK. FARTHER UPSTREAM SUBSIDENCE WILL LEAD LEE SIDE
WARMING ON THE FOOTHILLS OF THE ROCKIES...AND THIS WARM AIR WILL
MOVE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY BY FRIDAY. IN
FACT...THE 22.00 GEM/GFS/ECMWF ARE IN GOOD AGREEMENT THAT THE
SATURDAY 00Z RAB AT MSP SHOULD MEASURE ABOVE 0C AT H850. NOT EXACTLY
A HEAT WAVE...BUT SLIGHTLY MORE MILD NONE THE LESS. THIS WARM UP WILL
BE SHORT LIVED AS ANOTHER SHORTWAVE DRIVING THIS LOW LEVEL WARM AIR
ADVECTION WILL CAUSE A CYCLONE TO TRACK ACROSS SOUTHERN CANADA...AND
DRIVE A WEAK COLD FRONT THROUGH THE REGION. THIS FRONTAL BOUNDARY
WILL EVENTUALLY BECOME ORIENTED EAST/WEST...AND SET THE STAGE FOR A
POTENTIALLY SIGNIFICANT STORM SYSTEM TO DEVELOP NEXT WEEK OVER THE
MIDWEST.
IN SUMMARY...A FEW WEAK WAVED EMBEDDED IN NORTHWEST FLOW WILL KEEP
MID LEVEL CLOUDS IN TACT FOR MOST OF THIS WEEK...BUT NOTHING TO
MERIT HAVING ANY POPS IN THE FORECAST. TEMPERATURES WILL MODERATE
SLIGHTLY BY THE WEEKEND...BUT SHOULD STILL REMAIN BELOW CLIMATOLOGY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 611 AM CDT TUE OCT 22 2013
MAIN AVIATION CONCERN IS STRATOCU ATTEMPTING TO SLIDE SOUTH INTO
THE AREA... WHICH IS CURRENTLY PRODUCING WIDESPREAD MVFR CEILINGS.
THE SHORTWAVE TO OUR SOUTHWEST IS PRODUCING SOME LIGHT PCPN... BUT
IT WILL STAY SOUTH OF TAF SITES... WITH SOME VFR CEILINGS BEING
THE ONLY THING IT SHOULD PRODUCE. CURRENT THINKING IS THAT THE
MVFR CEILINGS WILL DROP SOUTH ACROSS ALL BUT KRWF... BUT WILL THEN
START TO RISE THROUGH THE DAY... AND PROBABLY SCATTER OUT DURING
THE EVENING HOURS. HOWEVER... THERE IS A FAIR DEGREE OF
UNCERTAINLY ON HOW STUBBORN THE CLOUDS WILL BE... AND THERE/S A
CHANCE FOR SOME DECENT BREAKS TODAY BUT ALSO FOR THINGS TO STICK
AROUND LONGER TONIGHT.
KMSP...MAIN CONCERN IS WITH CEILINGS DROPPING IN FROM THE NORTH.
IT APPEARS THEY WILL PRODUCE MVFR CONDITIONS FOR A GOOD PART OF
THE DAY... BUT WILL BE ABOVE 017 SO IMPACTS SHOULD BE MINIMAL. THE
SCATTERING OUT ADVERTISED FOR TONIGHT COULD EASILY OCCUR SOONER OR
LATER BY SEVERAL HOURS WITH MUCH DEPENDING UPON HOW MUCH RESIDUAL
MOISTURE WINDS UP TRAPPED BENEATH A SUBSIDENCE INVERSION AND AT
WHAT LEVEL THAT INVERSION MANIFESTS.
/OUTLOOK FOR KMSP/
WEDNESDAY AFTERNOON THROUGH THURSDAY...VFR. NORTHWEST WIND AROUND 10KT.
THURSDAY NIGHT...VFR. NORTHWEST WIND AROUND 10 KT BECOMING WEST.
FRIDAY...VFR. WEST WIND 5 TO 10 KT BECOMING SOUTHWEST 15 TO 20 KT.
FRIDAY NIGHT...MVFR CEILINGS POSSIBLE LATE. SOUTHWEST WIND 10 TO
20 KT BECOMING WEST.
SATURDAY...MVFR CEILINGS POSSIBLE EARLY. NORTHWEST WIND 15 TO 20
KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...
SHORT TERM...
LONG TERM...JRB
AVIATION...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
319 AM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT TUE OCT 22 2013
LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOW THE UPPER
LOW WHICH BROUGHT MUCH COLDER TEMPERATURES TO THE AREA BEING SHUNTED
INTO EASTERN ONTARIO AS A FEW REINFORCING SHORTWAVES DROP SOUTHEAST
THROUGH CENTRAL CANADA INTO THE HIGH PLAINS. THE MAIN SHORTWAVE OF
INTEREST FOR THE SHORT TERM CAN BE SEEN OVER EASTERN SOUTH DAKOTA...
AND IS HELPING TO GENERATE THE LIGHT PCPN SEEN ON RADAR AND SURFACE
OBS OVER FAR SOUTHWEST MINNESOTA... EASTERN SOUTH DAKOTA... AND
NORTHERN IOWA. MOST OF THIS ACTIVITY LOOKS LIKE IT WILL REMAIN SOUTH
OF OUR AREA THIS MORNING... SO MAINLY JUST MENTIONED SOME FLURRIES
OR LOW POPS WITH NO SNOWFALL ACCUMULATIONS. OTHERWISE... TODAY LOOKS
BENIGN ACROSS THE FORECAST AREA... WITH SOME PEAKS OF SUN
INTERSPERSED WITH LINGERING STRATOCU. WE MAINTAIN SOMEWHAT OF A
925-850MB THERMAL TROUGH OVER THE AREA TODAY... WHICH SHOULD KEEP
PLENTY OF CLOUDS IN PLACE... AND LATEST 11-3.9 MICRON IMAGERY SHOWS
PLENTY OF CLOUDS TO THE NORTH DROPPING SOUTH WITH TIME. HOWEVER...
THERE ARE INDICATIONS THAT THE BOUNDARY LAYER FLOW WILL BECOME MORE
ANTICYCLONIC THIS AFTERNOON... WHICH COULD WORK TO GENERATE SOME
DECENT BREAKS IN THE CLOUD COVER. PLAYED THINGS MORE PESSIMISTICALLY
FOR NOW GIVEN SATELLITE TRENDS AND FORECAST PROFILES... AND WENT
WITH MOSTLY CLOUDY SKIES FOR MUCH OF THE DAY INTO TONIGHT. THE NEXT
SHORTWAVE OF INTEREST WILL TAKE A VERY SIMILAR TRACK AS THIS
MORNING/S... AND LOOKS TO DROP BY TO OUR SOUTHWEST VERY LATE TONIGHT
INTO WEDNESDAY. AT THIS POINT... IT LOOKS LIKE ANY CHANCE FOR PCPN
WILL ONCE AGAIN BE CONFINED TO THE FAR SOUTHWEST/SOUTH... AND WILL
MAINLY BE ON WEDNESDAY. HOWEVER... DID INCLUDE SOME LOW POPS OVER
THE SOUTHWEST FOR VERY LATE TONIGHT AS SOME ISENTROPIC LIFT AND
FRONTOGENESIS START TO IMPINGE ON THE AREA. DID NOT MAKE ANY
SUBSTANTIVE CHANGES TO THE GOING TEMPERATURE FORECASTS... WHICH WILL
ONCE AGAIN BE QUITE A BIT BELOW NORMAL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 315 AM CDT TUE OCT 22 2013
EARLY MORNING WATER VAPOR IMAGERY WITH 500MB HEIGHTS AND WINDS
IDENTIFIED THE BROAD UPPER LEVEL RIDGE ORIENTED ALONG THE WEST COAST
OF NORTH AMERICA...WITH A DEEP TROUGH OVER THE GREAT LAKES REGION.
THE PV ANOMALY ASSOCIATED WITH THIS VORT MAX WILL DEVELOP A CYCLONE
ALONG THE EASTERN SHORE OF JAMES BAY...AND ANOMALOUSLY COLD AIR WILL
CONTINUE TO BE DRIVEN SOUTH ACROSS THE UPPER MIDWEST FOR THE NEXT
COUPLE OF DAYS.
MEANWHILE A TROPICAL PLUME OF MOISTURE ORIGINATING OVER SOUTHERN
MEXICO WAS STREAMING NORTHEASTWARD ACROSS THE EASTERN SEABOARD. BY
THURSDAY THIS SUBTROPICAL JET WILL PHASE WITH THE NORTHERN STREAM
TROUGH AND BOMB OUT A SUB 960MB SURFACE CYCLONE OFF THE COAST OF NEW
FOUNDLAND. THIS POWERFUL CYCLONE WILL CAUSE THE NORTHERLY WINDS
CURRENTLY IN PLACE ACROSS THE REGION TO BECOME MORE WESTERLY BY THE
END OF THE WEEK. FARTHER UPSTREAM SUBSIDENCE WILL LEAD LEE SIDE
WARMING ON THE FOOTHILLS OF THE ROCKIES...AND THIS WARM AIR WILL
MOVE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY BY FRIDAY. IN
FACT...THE 22.00 GEM/GFS/ECMWF ARE IN GOOD AGREEMENT THAT THE
SATURDAY 00Z RAB AT MSP SHOULD MEASURE ABOVE 0C AT H850. NOT EXACTLY
A HEAT WAVE...BUT SLIGHTLY MORE MILD NONE THE LESS. THIS WARM UP WILL
BE SHORT LIVED AS ANOTHER SHORTWAVE DRIVING THIS LOW LEVEL WARM AIR
ADVECTION WILL CAUSE A CYCLONE TO TRACK ACROSS SOUTHERN CANADA...AND
DRIVE A WEAK COLD FRONT THROUGH THE REGION. THIS FRONTAL BOUNDARY
WILL EVENTUALLY BECOME ORIENTED EAST/WEST...AND SET THE STAGE FOR A
POTENTIALLY SIGNIFICANT STORM SYSTEM TO DEVELOP NEXT WEEK OVER THE
MIDWEST.
IN SUMMARY...A FEW WEAK WAVED EMBEDDED IN NORTHWEST FLOW WILL KEEP
MID LEVEL CLOUDS IN TACT FOR MOST OF THIS WEEK...BUT NOTHING TO
MERIT HAVING ANY POPS IN THE FORECAST. TEMPERATURES WILL MODERATE
SLIGHTLY BY THE WEEKEND...BUT SHOULD STILL REMAIN BELOW CLIMATOLOGY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1057 PM CDT MON OCT 21 2013
SKIES HAVE CLEARED ACROSS A GOOD PART OF WEST CENTRAL AND CENTRAL
MN INTO SOUTHERN MN AND WISCONSIN...BUT NEXT SOUTHWARD SURGE OF
CLOUDS SEEMS TO BE TAKING PLACE PER SATELLITE AND OBS. LAMP DATA
SUGGEST SOME POTENTIAL FOR MVFR CEILINGS INTO OUR NORTHERN AND
EASTERN TAF SITES AFTER 09Z-10Z... AND ESPECIALLY AT KRNH AND
KEAU. OBS FROM PARK RAPIDS...BRAINERD INTO NWRN WISC DO SHOW A
BROAD AREA OF CEILINGS AROUND O15-025. HAVE ALSO ADDED SOME MVFR
AT KAXN BASEED ON OBS EVEN THOUGH MODEL DATA ARE NOT AS BULLISH ON
IT. NOT SURE WHAT TO MAKE OF EXPANSIVE MOISTURE TUESDAY
EVENING...PATTERN DOES NOT SEEM CONDUCIVE AS SHOULD BE SOME MODEST
SUBSIDENCE LATER TUESDAY AFTERNOON INTO THE EVENING.
AND IN SW MN...CLIPPER MENTIONED IN SHORT-TERM WILL LIKELY PASS
FAR ENOUGH WEST AND SOUTH OF KRWF TO ONLY BRING SOME OVC MID LEVEL
CLOUDS. LIGHT SNOW SHOULD BE FARTHER SOUTH AND WEST. FEW FLURRIES
AT BEST AT KRWF.
KMSP...MOSTLY CLEAR SHORTLY AFTER MIDNIGHT BUT THEN CEILINGS AROUND
045 SHOULD DROP SOUTHWARD AND MAY WELL CLIP KMSP. THIS WILL MOST
LIKELY ARRIVE AFTER 11Z. THERE ARE A COUPLE HINTS IN SOME MODEL
DATA THAT CEILINGS MAY EVEN DROP TO 2500 OR SO AROUND 11Z...BUT
NOT AT ALL CONFIDENT IN THIS...AND HAVE NOT ADDED ANY MVFR CEILINGS.
BUT IT IS SOMETHING TO WATCH FOR.
/OUTLOOK FOR KMSP/
WED...VFR. SW WIND LESS THAN 5 KT BECMG NW 5-10 KT.
THU...VFR. NW WIND 10-15 KT.
FRI...VFR. SW WIND 10 KT INCRG TO 15 TO 20 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...99
LONG TERM...JRB
AVIATION...TDK
AREA FORECAST DISCUSSION
NWS BILLINGS MT
319 PM MDT TUE OCT 22 2013
.SHORT TERM...VALID FOR WED AND THU...
UPPER RIDGE OVER THE WESTERN CONUS WILL REMAIN DOMINANT FOR THE
REGION THROUGH THE SHORT TERM PERIOD...THUS GENERALLY QUIET
WEATHER WILL CONTINUE FOR THE NEXT FEW DAYS. DRY DOWNSLOPE WARMING
HAS ALLOWED FOR TEMPS TODAY TO GET INTO THE 60S...WITH 68 DEGREES
AT LIVINGSTON AT 3PM. WEAK SHORTWAVE IN ALBERTA WILL DROP THROUGH
THE NW FLOW ALOFT AND ALLOW FOR A FRONTAL PASSAGE LATE TONIGHT AND
COOLER CANADIAN AIR TO OOZE INTO OUR AREA FOR TOMORROW...WITH A
SHIFT TO EASTERLY WINDS. ACCOMPANYING THIS FROPA WILL BE ENOUGH
SHALLOW MOISTURE TO BRING A FEW LIGHT SHOWERS OR SPRINKLES TO
MAINLY OUR EAST LATE TONIGHT INTO WEDNESDAY MORNING. COULD BE SOME
STRATUS BACKDOOR INTO OUR CENTRAL PARTS AND PERHAPS FOOTHILLS
WEDNESDAY MORNING...AND WILL NEED TO KEEP WATCH OF THIS...THOUGH
LATEST RAP IS NOT AGGRESSIVE WITH THIS AT ALL. EITHER WAY...EXPECT
COOLER TEMPS WEDNESDAY WITH HIGHS A GOOD 10 DEGREES LESS THAN
TODAY. THIS WILL TRANSLATE TO A CHILLIER WEDNESDAY NIGHT...
ESPECIALLY FOR OUR FAR EAST PER SFC RIDGING AND LOW LEVEL DRYING.
HAVE ADJUSTED LOW TEMPS AND DEWPTS FOR THIS.
COOLISH AIRMASS WITH EAST WINDS WILL PERSIST TO THURSDAY THOUGH
HEIGHTS WILL BEGIN TO RISE AGAIN FROM THE WEST. COULD SEE 60
DEGREES IN OUR WEST THURSDAY AFTERNOON...WITH ONSET OF WEAK LEE
SIDE TROFFING BY THURSDAY NIGHT.
JKL
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
UPPER RIDGING/DRY NW FLOW WILL BE OVER THE REGION THROUGH SAT.
MODELS CONTINUE TO DIG A STRONG SHORTWAVE INTO THE PACIFIC NW SUN
AND SUN NIGHT. THE GFS MAINLY DIGS IT SOUTH OF THE REGION AS AN OPEN
WAVE THROUGH VERY LATE MON. MEANWHILE...THE ECMWF DIGS STRONG
SHORTWAVE/JET ENERGY THROUGH THE REGION SUN NIGHT...DEVELOPING AN
UPPER LEVEL LOW JUST SW OF THE REGION MON...WHERE IT MEANDERS FOR
ABOUT 18 TO 24 HRS BEFORE SLOWLY SINKING SOUTH. BOTH MODELS BRING
PRECIPITATION INTO THE AREA LATE SUN INTO SUN EVENING BEHIND THE
COLD FRONT. 850 MB TEMPERATURES ARE FORECAST TO BE WELL BELOW
ZERO DEGREES C BY 12Z MON. THESE TEMPERATURES WILL REMAIN OVER THE
REGION THROUGH TUE. BOTH MODEL SOLUTIONS BRING STRONG UPPER LEVEL
JET ENERGY/DIVERGENCE AND LOW/MID LEVEL FRONTOGENESIS THROUGH THE
CWA SUN NIGHT INTO MON...WITH A PROLONGED PERIOD OF UPSLOPE
FLOW...SO A PROLONGED SNOW EVENT IS LOOKING MORE AND MORE LIKELY.
BECAUSE MODELS ARE IN SLIGHTLY BETTER AGREEMENT...I DID INCREASE
THE CHANCE OF SNOW A BIT SUN NIGHT INTO MON...ESPECIALLY IN
FAVORED UPSLOPE REGIONS SUCH AS THE RED LODGE FOOTHILLS...THE
SHERIDAN FOOTHILLS/BIG HORN MTNS AND SOUTHEAST MONTANA FROM BIG
HORN COUNTY E TOWARDS POWDER RIVER COUNTY. STILL...IT IS SEVERAL
DAYS OUT...SO THERE REMAINS A GOOD DEAL OF UNCERTAINTY WITH THIS
POTENTIAL SNOW EVENT.
DID RAISE TEMPS A FEW DEGREES FRI AND SAT WITH UPPER LEVEL
RIDGING LOOKING MORE LIKELY...THUS HIGHS ARE EXPECTED TO REACH
UPPER 50S TO MID 60S. SUN LOOKS TO BE A TRANSITION DAY AS THE
FRONT MOVES THROUGH...WITH UNSEASONABLY CHILLY HIGHS MON...IN THE
20S AND 30S. STC
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL OVER THE AREA TODAY AND TONIGHT. A
WEAK COLD FRONT WILL SWITCH THE WINDS TO A MORE N TO NE DIRECTION
EARLY WED MORNING...INCREASING THE POTENTIAL FOR AREAS OF MVFR
CEILINGS WED MORNING THROUGH EARLY WED AFTERNOON. STC
&&
.PRELIMINARY POINT TEMP/POPS...
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 040/053 033/055 040/063 040/063 038/053 028/032 018/032
00/B 00/U 00/U 00/U 02/W 55/S 41/B
LVM 033/055 029/061 036/063 035/064 035/052 026/034 011/031
00/B 00/U 00/U 00/U 03/W 55/S 32/J
HDN 036/053 029/057 034/064 035/064 038/054 029/034 021/032
00/B 00/U 00/U 00/U 02/W 56/S 41/B
MLS 040/051 028/052 033/062 035/062 038/056 029/034 022/034
02/W 00/B 00/U 00/U 01/B 45/S 31/B
4BQ 038/051 028/053 034/062 036/062 037/057 030/034 023/031
02/W 00/B 00/U 00/U 01/B 45/S 42/J
BHK 037/047 023/047 030/058 034/059 035/054 028/033 021/033
22/W 00/U 00/U 00/U 01/B 34/S 31/B
SHR 036/052 030/058 034/063 033/063 034/056 028/028 013/027
00/B 00/U 00/U 00/U 01/B 56/S 43/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
620 PM CDT WED OCT 23 2013
.SYNOPSIS...
ISSUED AT 313 PM CDT WED OCT 23 2013
H5 ANALYSIS THIS MORNING HAS A CLOSED LOW OVER NRN
QUEBEC...WITH A TROUGH OF LOW PRESSURE EXTENDING SWD INTO GEORGIA
AND FLORIDA. RIDGING WAS PRESENT ACROSS THE PACIFIC COAST...WITH A
CLOSED LOW LOCATED OFF THE SRN CALIFORNIA COAST. ACROSS THE NRN
ROCKIES AND CENTRAL AND NORTHERN PLAINS...BROAD NWRLY FLOW CONTINUED
WITH A STRONG JET STREAK EXTENDING FROM EASTERN MONTANA INTO THE SRN
APPALACHIANS. AT THE SURFACE...LOW PRESSURE WAS PRESENT OVER SOUTH
CENTRAL NEBRASKA WITH A FRONT EXTENDING FROM THE NORTHERN PANHANDLE
INTO SERN NEBRASKA. CLOUDS WERE COMMON NORTH OF THIS FEATURE WITH
MAINLY CLEAR SKIES ACROSS SWRN NEBRASKA. TEMPERATURES AS OF 2 PM CDT
RANGED FROM A COOL 49 DEGREES AT ONEILL TO 67 AT IMPERIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 313 PM CDT WED OCT 23 2013
QUIET NIGHT EXPECTED ACROSS THE HIGH PLAINS. NOT MUCH HAS CHANGED IN
THE UPPER LEVELS OVER THE PAST FEW DAYS...AS HIGH PRESSURE RIDGE TO
THE WEST AND A DEEP TROUGH TO THE EAST. MID/HIGH LEVEL CLOUDS
CONTINUE TO STREAM TO THE SE ALONG THE FAST MOVING NW FLOW. AT THE
SFC A WEAK COLD FRONT IS MOVING SOUTHEAST ACROSS THE AREA. AS
SLIGHTLY COOLER AIR SHIFTS SOUTH ACROSS THE AREA...EXPECT THE CLOUDS
TO SPREAD A LITTLE FURTHER TO THE WEST. TEMPS TONIGHT ARE TRICKY AS
PARTLY CLOUDY SKIES ARE EXPECTED. WINDS SHOULD DECOUPLE AND BECOME
NEARLY CALM...AND WHERE THERE IS ANY CLEARING TEMPS WILL DROP
QUICKLY. HOWEVER AS THE CLOUDS RETURN THE TEMPS WILL JUMP UP.
FORECAST IS FOR POCKETS OF CLEARING...AND LOW TEMPS SHOULD DIP INTO
THE UPPER 20S TO LOWER 30S. TEMPS COOLER TOMORROW AS MORE CLOUDS ARE
EXPECTED AND RIDGE IS SUPPRESSED SLIGHTLY...HIGHS ONLY REBOUND INTO
THE UPPER 40S...N CENTRAL...TO LOWER AND MID 50S...ELSEWHERE. MEAGER
MOISTURE IS NOT COMBATED WITH THE STEEP LAPSE RATES WE HAVE SEEN
LATELY FOR AFTERNOON SHOWERS...THUS FORECAST IS DRY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 313 PM CDT WED OCT 23 2013
THURSDAY NIGHT THROUGH SATURDAY...THE MAIN FORECASTING
CHALLENGE THROUGH SATURDAY IS TEMPERATURES...AS NWRLY FLOW ALOFT
CONTINUES OVER THE NEXT 36 TO 84 HOURS. FOR THURSDAY NIGHT...HIGH
PRESSURE WILL TRACK SOUTHEAST INTO THE LOWER MISSOURI VALLEY. THIS
WILL RESULT IN SRLY WINDS TOWARD 12Z FRIDAY. MID LEVEL
CLOUDINESS...WHICH WILL BE PREVALENT ACROSS THE CENTRAL AND WESTERN
CWA THURSDAY...WILL TRACK EAST AND DISSIPATE THURSDAY NIGHT AS THE
RIGHT REAR QUAD OF THE JET SHIFTS EAST INTO THE UPPER MISSISSIPPI
VALLEY. WITH LIGHT SRLY WINDS EXPECTED FRIDAY MORNING...DECIDED TO
KEEP LOWS IN THE LOWER 30S. FOR FRIDAY...SRLY WINDS WILL INCREASE ON
THE BACK SIDE OF THE EXITING HIGH...AND EAST OF A DEVELOPING TROUGH
OF LOW PRESSURE ACROSS THE FRONT RANGES OF COLORADO AND EASTERN
WYOMING. THE SRLY FLOW WILL CONTINUE TO PUSH WARMER AIR INTO THE
FORECAST AREA FRIDAY. BY 21Z FRIDAY...H85 TEMPS RANGE FROM 7C IN THE
NORTHEAST...TO AROUND 12C IN THE SOUTHWEST. THESE TEMPS WERE SIMILAR
TO THE 12Z GFS OUTPUT...SO FEEL CONFIDENT IN ONGOING FCST OF UPPER
50S IN THE EAST AND MID 60S IN THE SOUTH. UTILIZED A BLEND OF MAV
AND MET GUIDANCE FOR HIGHS DURING THE FRIDAY PERIOD...AS THE NAM IS
ABOUT 6 HOURS SLOWER IN FORCING THE COLD AIRMASS EAST...AND ACTUALLY
HAS THE WARMEST H85 TEMPS FRIDAY EVENING VS. FRIDAY AFTERNOON. ON
FRIDAY NIGHT...A REINFORCING SHOT OF COLD AIR WILL PUSH INTO
NEBRASKA FROM THE DAKOTAS. BOTH THE NAM AND GFS PUSH THE BULK OF THE
COLDER AIR INTO THE FORECAST AREA BY 12Z SATURDAY. HOWEVER...THE NAM
IS SLIGHTLY COLDER IN THE NORTHEAST COMPARED TO THE GFS SOLN...WHILE
THE GFS IS COLDER IN THE SOUTHWEST COMPARED TO THE NAM SOLN. THE NAM
SOLN HAS A TIGHTER TEMPERATURE GRADIENT ACROSS THE CWA SATURDAY AND
GIVEN THE SHALLOW NATURE OF THE COLD AIRMASS...SEEMS MORE BELIEVABLE
ATTM. WITH THIS IN MIND...UTILIZED THE NAM 21Z H85 TEMPS FOR HIGHS
SATURDAY...WHICH YIELDED LOWER 50S IN THE NORTHEAST TO MIDDLE 60S IN
THE FAR SOUTHWEST.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...THE MAIN FORECASTING
CHALLENGE IN THE LONG TERM CONTINUES TO LIE WITH FRONTAL TIMING OF A
STRONG ARCTIC COLD FRONT AND ASSOCIATED PRECIPITATION MONDAY
NIGHT/TUESDAY AND BEYOND BASED ON THE TRACK OF THE UPPER LEVEL
SYSTEM TRAILING THE COLD FRONT. FOR SUNDAY...WARM AIR WILL SURGE
INTO SOUTHWESTERN AND WESTERN NEBRASKA IN ADVANCE OF AN APPG ARCTIC
COLD FRONT. H85 TEMPS WILL SURGE INTO THE LOWER TO MIDDLE TEENS
SUNDAY AFTERNOON...RESULTING IN HIGHS IN THE 60S TO LOWER TO MIDDLE
70S. ON MONDAY...A STRONG ARCTIC COLD FRONT WILL TRACK ACROSS
WESTERN AND NORTH CENTRAL NEBRASKA. TEMPS WILL VARY WIDELY MONDAY
WITH 50S IN THE SOUTH AND 40S IN THE NORTH. THERE IS SOME TIMING
DIFFERENCES BETWEEN THE GFS AND LATEST EURO SOLN WITH THE EURO
PUSHING THE FRONT THROUGH THE FORECAST AREA MONDAY MORNING VS. MID
DAY MONDAY AS IS DEPICTED IN THE GFS. WITH THE DIFFERENCES...DECIDED
TO LEAVE HIGHS AS IS FOR MONDAY AND CONTINUE TO MONITOR THE LATEST
FORECAST TRENDS. FOR MONDAY NIGHT THROUGH WEDNESDAY...AN UPPER LEVEL
TROUGH WILL DROP SOUTH INTO THE CENTRAL ROCKIES...EMERGING ONTO THE
SOUTHERN PLAINS LATE WEDNESDAY INTO THURSDAY. WEAK ISENTROPIC LIFT
DEVELOPS MONDAY NIGHT...AND PERSISTS INTO WEDNESDAY ACROSS WESTERN
AND NORTH CENTRAL NEBRASKA. WILL CONTINUE MENTION OF RAIN OR SNOW
MONDAY NIGHT THROUGH WEDNESDAY...BUT WILL KEEP POPS ON THE LOW SIDE
AS QPF`S ARE NOT EXPECTED TO BE SIGNIFICANT ACROSS THE FA FOR THE
EVENT. THIS IS DUE TO THE POSITIVE TILT OF THE MAIN UPPER LEVEL
TROUGH...AND THE INITIAL FROPA...WHICH SHOVES THE BEST MOISTURE WELL
EAST OF THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 618 PM CDT WED OCT 23 2013
THE NAM AND THE RAP MODELS SHOW MVFR CIGS DEVELOPING NORTH
TONIGHT. THESE LOW CIGS SHOULD SPREAD SOUTH AND WEST BY MORNING.
MVFR/IFR MAY PERSIST INTO THE AFTN ALONG AND WEST OF HIGHWAY 61
WHILE VFR DEVELOPS ALONG AND EAST OF HIGHWAY 83.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...MASEK
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
254 PM CDT TUE OCT 22 2013
.SHORT TERM...TONIGHT THROUGH FRIDAY.
THE FIRST CLIPPER SYSTEM WAS MOVING WELL SOUTHEAST OF THE REGION
THIS AFTERNOON. MEANWHILE...THE NEXT CLIPPER WAS NOTED COMING OUT
OF ALBERTA. 12Z UPPER AIR CHARTS SHOWED ABOUT 20 METER HEIGHT
FALLS AT 500 MB...WITH SATURATION AT 700 MB. THIS WILL CONTINUE TO
DIVE SOUTHEAST...AND COULD BRING SOME PRECIP TO NORTHEAST NEBRASKA
LATE TONIGHT AFTER 09Z...ALTHOUGH LATEST 18Z RUN OF THE RAP AND
12Z ECMWF SUGGEST THAT MEASURABLE PRECIP COULD EVEN HOLD OFF UNTIL
AFTER 12Z IN NORTHEAST NEBRASKA. THERMAL PROFILES SUGGEST THIS
COULD BE A RAIN/SNOW MIXTURE ALONG THE NE/SD BORDER REGION.
CLIPPER THEN CONTINUES TO MOVE EAST SOUTHEAST AND BRINGS PRECIP
CHANCES DOWN THE MISSOURI RIVER THROUGH THE MORNING AND INTO THE
AFTERNOON...WHERE IT COULD BE A RAIN/SNOW MIXTURE EARLY IN THE
MORNING IN NEBRASKA AND NORTHWEST IOWA...BUT AS TEMPS WARM...LIKELY
BECOMING ALL RAIN BY 15Z AND BEYOND. NOT EXPECTING ANY ACCUMULATION
THOUGH...JUST A RAIN/SNOW MIX POSSIBLE. PRECIP CHANCES WILL CONTINUE
TO WIND DOWN THROUGH THE AFTERNOON AND END ALTOGETHER BY WEDNESDAY
EVENING. THE NAM ALSO HAD A SLIGHTLY MORE WESTERN TRACK...WHICH
SEEMED TO BE TOO FAR WEST GIVEN THE PLACEMENT OF THE DYNAMICS.
BEYOND THEN...NO REAL WEATHER CONCERNS AS HIGH PRESSURE SETTLES
ACROSS THE PLAINS. THIS WILL RESULT IN A COUPLE OF COLD NIGHTS
WEDNESDAY NIGHT...AND EVEN A COUPLE OF DEGREES COLDER THURSDAY
THAN WEDNESDAY NIGHT WITH MOSTLY CLEAR SKIES. DAYTIME TEMPS DO
REBOUND INTO THE MID/UPPER 50S BY FRIDAY AS SOUTHWEST FLOW RETURNS
TO THE REGION.
DEWALD
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY. EXTENDED MODELS MAINTAIN
SIMILAR TRENDS IN BREAKING DOWN THE WESTERN RIDGE OVER THE WEEKEND
AS UPPER WAVE DROPS INTO THE NORTHERN ROCKIES WITH DRY AND GENERALLY
MILD CONDITIONS THROUGH THIS TIME.
PATTERN TURNS MORE ACTIVE EARLY NEXT WEEK. SOME TIMING ISSUES SHOW
UP ON MONDAY WITH COLD FRONT THAT MOVES THROUGH THE AREA WITH A
BLENDED SOLUTION USED FOR THE FORECAST. ECMWF HOLDS A STRONGER UPPER
WAVE FURTHER TO THE NORTHWEST THAN THE MORE PROGRESSIVE AND LESS
AMPLIFIED GFS THROUGH TUESDAY. CHANCE POPS WERE CONTINUED FOR MONDAY
INTO TUESDAY WITH PRECIP TYPE LESS CERTAIN DEPENDING ON TIMING OF
THE COLDER AIR.
FOBERT
&&
.AVIATION...18Z TAFS FOR KOMA...KOFK...KLNK. CIGS ARE VARIABLE
BETWEEN FL009-FL035...SO MAINLY MVFR...WITH SOME PATCHY IFR AND
LOW VFR CIGS. MVFR CONDITIONS ARE EXPECTED TO MIX OUT AND CIGS
WILL BECOME MORE VFR DURING THE 19Z-21Z PERIOD AND CLOUDS SHOULD
SCATTER OUT THIS EVENING. NORTHWEST SURFACE WINDS WILL ALSO BE
VARIABLE...WITH 8-14KT WINDS AT KOFK AND KOMA...AND STRONGER
10-18KT SUSTAINED WINDS WITH HIGHER GUSTS AT KLNK THRU 00Z.
SURFACE HIGH PRESSURE WILL BUILD IN WITH DIMINISHING WINDS. A WEAK
WEATHER DISTURBANCE WILL BRING INCREASING MID CLOUDS AFTER 06Z
WITH A RAIN/SNOW MIX POSSIBLE AT KOFK/KOMA. FOR NOW WILL CONSIDER
MENTIONING A PROB30 IN THOSE TAF WED AM.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
125 PM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM CDT TUE OCT 22 2013
MAIN FORECAST CONCERNS WILL BE LIGHT SHOWERS OR SPRINKLES THIS
MORNING AND TEMPERATURES.
CURRENT RADAR TRENDS SHOW THAT THE SPRINKLES OR LIGHT SHOWERS
HAVE MOVED INTO THE SOUTHEAST HALF OR SO OF THE FORECAST AREA
EARLY THIS MORNING. SATELLITE SHOWS A FEW BREAKS IN THE
CLOUDS...BUT MOSTLY CLOUDY SKIES WILL PERSIST. THE CLOUD COVER HAS
HELPED TO KEEP TEMPERATURES A LITTLE ON THE WARMER SIDE.
MODELS HAVE HAD SOME LIGHT SHOWERS OR SPRINKLES MOVING THROUGH
THE FORECAST AREA DURING THE MORNING. THE NAM AND GFS INDICATE
THAT THESE WILL CONTINUE INTO THE MORNING AND BE GONE BY MID
DAY...BUT THE HRRR AND 4KM WRF ARE A LITTLE QUICKER TO MOVE THINGS
THROUGH THE AREA AND INDICATE THAT THE PRECIPITATION COULD BE DONE
AS EARLY AS BY SUN RISE THIS MORNING. WITH THE CURRENT LOCATION OF
THE SPRINKLES ON THE RADAR AM INCLINED TO BELIEVE THE SHORT TERM
MODELS AND BRING AN EARLY END TO THE PRECIPITATION. BASED ON THE
MOVEMENT OF THE PRECIPITATION...THE RETURNS ON THE RADAR AND
PRECIPITATION AMOUNTS AS IT MOVES OVER EXPECT THAT SPRINKLES WILL
BE THE EXTENT OF THE PRECIPITATION.
THE SURFACE PRESSURE GRADIENT TIGHTENS FOR A WHILE THIS MORNING
AND THE WINDS AT 850MB ARE 25 TO 35 KTS DURING THE MORNING AND
INTO THE AFTERNOON HOURS. EXPECT THERE TO BE BREEZY CONDITIONS
DURING THE LATE MORNING INTO EARLY AFTERNOON BEFORE WINDS DIMINISH
AS THE SUN GOES DOWN THIS AFTERNOON. CLOUDS WILL BE MORE PREVALENT
IN THE NORTHEAST PART OF THE FORECAST AREA AND WILL KEEP
TEMPERATURES ON THE LOWER SIDE WHILE A LITTLE MORE SUN AND WARMER
TEMPERATURES ALOFT WILL ALLOW FOR SOME WARMER TEMPERATURES IN THE
SOUTHWEST.
SOME CLOUD COVER WILL CONTINUE ACROSS THE AREA THROUGH THE NIGHT
TONIGHT...BUT DESPITE THE CLOUDS TEMPERATURES ACROSS THE AREA WILL
BE COOLER THAN TONIGHT AS THE WIND DIMINISHES AND A FEW BREAKS IN
THE CLOUDS MOVE THROUGH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 425 AM CDT TUE OCT 22 2013
BIGGEST CHALLENGE WILL BE DETERMINING TEMPERATURES.
THE LONG TERM MODELS CONTINUE TO FORECAST NORTHWEST FLOW AT THE
BEGINNING OF THE LONG TERM FORECAST AS WE WILL BE SITUATED BETWEEN A
BROAD SYNOPTIC LONGWAVE TROUGH TO THE EAST AND A RIDGE ALONG THE
WEST COAST...WITH AN EMBEDDED CUTOFF LOW OFF THE SOUTHERN CALIFORNIA
COAST. THE UPPER LEVEL PATTERN WILL BE HIGHLY AMPLIFIED TO BEGIN THE
LONG TERM.
THERE COULD BE JUST ENOUGH INFLUENCE LEFT FROM A SHORTWAVE TROUGH
FORECAST TO GIVE US A SHOT AT SOME LIGHT PRECIPITATION IN OUR FAR
NORTHEAST AS THE SHORTWAVE TROUGH DEPARTS TO THE SOUTHEAST. THIS SEEMS
TO BE A NEAR COPY OF WHAT HAS HAPPENED OVERNIGHT AND INTO THIS
MORNING...EXCEPT ENERGY WILL BE A BIT FARTHER TO THE
EAST...LESSENING OUR CHANCES OF MUCH PRECIPITATION AND HAVE KEPT IT
OUT OF THE FORECAST...ANTICIPATING THAT ANY PRECIPITATION WILL BE
JUST TO THE EAST. MODELS INDICATE CONSIDERABLE HEIGHT RISES BEHIND
THE COLD FRONT ASSOCIATED WITH THE AFOREMENTIONED WAVE AND I HAVE
INCREASED WIND SPEEDS ACCORDINGLY. FOR THE MOST PART...I KEPT HIGH
TEMPERATURES CLOSE TO PREVIOUS FORECASTS. I HAVE LOWERED
TEMPERATURES A FEW DEGREES FOR WEDNESDAY NIGHT AS SKY COVER SHOULD
BE RELATIVELY SCANT AND WIND SPEEDS SLACKEN. THIS COULD BE THE FIRST
HARD FREEZE FOR MANY AREAS OF THE CWA. ALSO...THURSDAY NIGHT COULD
BE TRICKY FOR LOW TEMPERATURES AS RETURN FLOW COULD CAUSE
TEMPERATURES TO STEADY OUT OR EVEN RISE BY OVERNIGHT...ESPECIALLY
SOUTHWEST. IN FACT...OUR SOUTHWEST MAY NOT COOL THAT MUCH AT ALL AS
WARM AIR ADVECTION TAKES OVER THERE FIRST. AS A RESULT...LOW
TEMPERATURES HAVE BEEN RAISED IN OUR FAR SOUTHWEST TO THE MID 30S TO
NEAR 40...WHILE CENTRAL AND EASTERN AREAS WILL HAVE LOWS IN THE MID
TO UPPER 20S...AND AGAIN...WITH TEMPERATURES BECOME STEADY OR SLOWLY
RISING BY THE OVERNIGHT HOURS.
TEMPERATURES WILL BE RATHER SEASONABLE FOR THE MOST PART FOR THE
REST OF THE LONG TERM. FRIDAY NIGHT LOOKS LIKE THE WARMEST BEFORE
ANOTHER COOL SHOT OF AIR COMES IN WITH ANOTHER WAVE. PATTERN STILL
SHOULD BECOME MORE QUASI-ZONAL BY SUNDAY...AS MODELS HAVE BEEN
ADVERTISING FOR AWHILE. THIS IS A RESULT OF A MORE SIGNIFICANT
SHORTWAVE TROUGH ENTERING THE PACIFIC NORTHWEST. THERE COULD BE A
NOTICEABLE WARM-UP IN ADVANCE OF THIS WAVE...BUT I AM GETTING MIXED
SIGNALS FROM OPERATION AND ENSEMBLE PREDICTIONS AND I FIND IT BEST
TO STICK WITH THE INITIAL ALLBLEND GRIDS. THE FORECAST ESSENTIALLY
STAYS DRY THROUGH MONDAY AS TIMING OF THIS WAVE STILL KEEPS IT FAR
ENOUGH AWAY TO BRING IN MUCH PRECIPITATION TO OUR AREA AND A COLD
FRONT SHOULD BE FAR ENOUGH EAST TO KEEP ANYTHING THAT DEVELOPS ALONG
IT TO OUR EAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 119 PM CDT TUE OCT 22 2013
A BRISK NORTHWEST WIND WILL CONTINUE THROUGH THE AFTERNOON BUT
SHOULD QUICKLY DIE DOWN AFTER SUNSET AND EVEN BECOME LIGHT AND
VARIABLE WITHIN ONE TO TWO HOURS AFTER SUNSET. THE WIND WILL
BECOME MORE SOUTHERLY TO SOUTHWESTERLY BY DAWN ON WEDNESDAY AND
REMAIN FAIRLY LIGHT THROUGH WEDNESDAY MORNING. CLOUDS WILL BE
PRESENT THROUGHOUT THE PERIOD...ALTHOUGH THE CLOUDS SHOULD BE HIGH
ENOUGH TO KEEP CEILINGS VFR.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...HEINLEIN
AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
620 AM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM CDT TUE OCT 22 2013
MAIN FORECAST CONCERNS WILL BE LIGHT SHOWERS OR SPRINKLES THIS
MORNING AND TEMPERATURES.
CURRENT RADAR TRENDS SHOW THAT THE SPRINKLES OR LIGHT SHOWERS
HAVE MOVED INTO THE SOUTHEAST HALF OR SO OF THE FORECAST AREA
EARLY THIS MORNING. SATELLITE SHOWS A FEW BREAKS IN THE
CLOUDS...BUT MOSTLY CLOUDY SKIES WILL PERSIST. THE CLOUD COVER HAS
HELPED TO KEEP TEMPERATURES A LITTLE ON THE WARMER SIDE.
MODELS HAVE HAD SOME LIGHT SHOWERS OR SPRINKLES MOVING THROUGH
THE FORECAST AREA DURING THE MORNING. THE NAM AND GFS INDICATE
THAT THESE WILL CONTINUE INTO THE MORNING AND BE GONE BY MID
DAY...BUT THE HRRR AND 4KM WRF ARE A LITTLE QUICKER TO MOVE THINGS
THROUGH THE AREA AND INDICATE THAT THE PRECIPITATION COULD BE DONE
AS EARLY AS BY SUN RISE THIS MORNING. WITH THE CURRENT LOCATION OF
THE SPRINKLES ON THE RADAR AM INCLINED TO BELIEVE THE SHORT TERM
MODELS AND BRING AN EARLY END TO THE PRECIPITATION. BASED ON THE
MOVEMENT OF THE PRECIPITATION...THE RETURNS ON THE RADAR AND
PRECIPITATION AMOUNTS AS IT MOVES OVER EXPECT THAT SPRINKLES WILL
BE THE EXTENT OF THE PRECIPITATION.
THE SURFACE PRESSURE GRADIENT TIGHTENS FOR A WHILE THIS MORNING
AND THE WINDS AT 850MB ARE 25 TO 35 KTS DURING THE MORNING AND
INTO THE AFTERNOON HOURS. EXPECT THERE TO BE BREEZY CONDITIONS
DURING THE LATE MORNING INTO EARLY AFTERNOON BEFORE WINDS DIMINISH
AS THE SUN GOES DOWN THIS AFTERNOON. CLOUDS WILL BE MORE PREVALENT
IN THE NORTHEAST PART OF THE FORECAST AREA AND WILL KEEP
TEMPERATURES ON THE LOWER SIDE WHILE A LITTLE MORE SUN AND WARMER
TEMPERATURES ALOFT WILL ALLOW FOR SOME WARMER TEMPERATURES IN THE
SOUTHWEST.
SOME CLOUD COVER WILL CONTINUE ACROSS THE AREA THROUGH THE NIGHT
TONIGHT...BUT DESPITE THE CLOUDS TEMPERATURES ACROSS THE AREA WILL
BE COOLER THAN TONIGHT AS THE WIND DIMINISHES AND A FEW BREAKS IN
THE CLOUDS MOVE THROUGH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 425 AM CDT TUE OCT 22 2013
BIGGEST CHALLENGE WILL BE DETERMINING TEMPERATURES.
THE LONG TERM MODELS CONTINUE TO FORECAST NORTHWEST FLOW AT THE
BEGINNING OF THE LONG TERM FORECAST AS WE WILL BE SITUATED BETWEEN A
BROAD SYNOPTIC LONGWAVE TROUGH TO THE EAST AND A RIDGE ALONG THE
WEST COAST...WITH AN EMBEDDED CUTOFF LOW OFF THE SOUTHERN CALIFORNIA
COAST. THE UPPER LEVEL PATTERN WILL BE HIGHLY AMPLIFIED TO BEGIN THE
LONG TERM.
THERE COULD BE JUST ENOUGH INFLUENCE LEFT FROM A SHORTWAVE TROUGH
FORECAST TO GIVE US A SHOT AT SOME LIGHT PRECIPITATION IN OUR FAR
NORTHEAST AS THE SHORTWAVE TROUGH DEPARTS TO THE SOUTHEAST. THIS SEEMS
TO BE A NEAR COPY OF WHAT HAS HAPPENED OVERNIGHT AND INTO THIS
MORNING...EXCEPT ENERGY WILL BE A BIT FARTHER TO THE
EAST...LESSENING OUR CHANCES OF MUCH PRECIPITATION AND HAVE KEPT IT
OUT OF THE FORECAST...ANTICIPATING THAT ANY PRECIPITATION WILL BE
JUST TO THE EAST. MODELS INDICATE CONSIDERABLE HEIGHT RISES BEHIND
THE COLD FRONT ASSOCIATED WITH THE AFOREMENTIONED WAVE AND I HAVE
INCREASED WIND SPEEDS ACCORDINGLY. FOR THE MOST PART...I KEPT HIGH
TEMPERATURES CLOSE TO PREVIOUS FORECASTS. I HAVE LOWERED
TEMPERATURES A FEW DEGREES FOR WEDNESDAY NIGHT AS SKY COVER SHOULD
BE RELATIVELY SCANT AND WIND SPEEDS SLACKEN. THIS COULD BE THE FIRST
HARD FREEZE FOR MANY AREAS OF THE CWA. ALSO...THURSDAY NIGHT COULD
BE TRICKY FOR LOW TEMPERATURES AS RETURN FLOW COULD CAUSE
TEMPERATURES TO STEADY OUT OR EVEN RISE BY OVERNIGHT...ESPECIALLY
SOUTHWEST. IN FACT...OUR SOUTHWEST MAY NOT COOL THAT MUCH AT ALL AS
WARM AIR ADVECTION TAKES OVER THERE FIRST. AS A RESULT...LOW
TEMPERATURES HAVE BEEN RAISED IN OUR FAR SOUTHWEST TO THE MID 30S TO
NEAR 40...WHILE CENTRAL AND EASTERN AREAS WILL HAVE LOWS IN THE MID
TO UPPER 20S...AND AGAIN...WITH TEMPERATURES BECOME STEADY OR SLOWLY
RISING BY THE OVERNIGHT HOURS.
TEMPERATURES WILL BE RATHER SEASONABLE FOR THE MOST PART FOR THE
REST OF THE LONG TERM. FRIDAY NIGHT LOOKS LIKE THE WARMEST BEFORE
ANOTHER COOL SHOT OF AIR COMES IN WITH ANOTHER WAVE. PATTERN STILL
SHOULD BECOME MORE QUASI-ZONAL BY SUNDAY...AS MODELS HAVE BEEN
ADVERTISING FOR AWHILE. THIS IS A RESULT OF A MORE SIGNIFICANT
SHORTWAVE TROUGH ENTERING THE PACIFIC NORTHWEST. THERE COULD BE A
NOTICEABLE WARM-UP IN ADVANCE OF THIS WAVE...BUT I AM GETTING MIXED
SIGNALS FROM OPERATION AND ENSEMBLE PREDICTIONS AND I FIND IT BEST
TO STICK WITH THE INITIAL ALLBLEND GRIDS. THE FORECAST ESSENTIALLY
STAYS DRY THROUGH MONDAY AS TIMING OF THIS WAVE STILL KEEPS IT FAR
ENOUGH AWAY TO BRING IN MUCH PRECIPITATION TO OUR AREA AND A COLD
FRONT SHOULD BE FAR ENOUGH EAST TO KEEP ANYTHING THAT DEVELOPS ALONG
IT TO OUR EAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 620 AM CDT TUE OCT 22 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH MAINLY MID
LEVEL CLOUDS IN AND OUT. WINDS ARE EXPECTED TO INCREASE DURING THE
DAY WITH THE STRONGEST WINDS LATE THIS MORNING INTO EARLY THIS
AFTERNOON. BY EVENING THE WINDS WILL START TO DIMINISH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...HEINLEIN
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
426 AM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM CDT TUE OCT 22 2013
MAIN FORECAST CONCERNS WILL BE LIGHT SHOWERS OR SPRINKLES THIS
MORNING AND TEMPERATURES.
CURRENT RADAR TRENDS SHOW THAT THE SPRINKLES OR LIGHT SHOWERS
HAVE MOVED INTO THE SOUTHEAST HALF OR SO OF THE FORECAST AREA
EARLY THIS MORNING. SATELLITE SHOWS A FEW BREAKS IN THE
CLOUDS...BUT MOSTLY CLOUDY SKIES WILL PERSIST. THE CLOUD COVER HAS
HELPED TO KEEP TEMPERATURES A LITTLE ON THE WARMER SIDE.
MODELS HAVE HAD SOME LIGHT SHOWERS OR SPRINKLES MOVING THROUGH
THE FORECAST AREA DURING THE MORNING. THE NAM AND GFS INDICATE
THAT THESE WILL CONTINUE INTO THE MORNING AND BE GONE BY MID
DAY...BUT THE HRRR AND 4KM WRF ARE A LITTLE QUICKER TO MOVE THINGS
THROUGH THE AREA AND INDICATE THAT THE PRECIPITATION COULD BE DONE
AS EARLY AS BY SUN RISE THIS MORNING. WITH THE CURRENT LOCATION OF
THE SPRINKLES ON THE RADAR AM INCLINED TO BELIEVE THE SHORT TERM
MODELS AND BRING AN EARLY END TO THE PRECIPITATION. BASED ON THE
MOVEMENT OF THE PRECIPITATION...THE RETURNS ON THE RADAR AND
PRECIPITATION AMOUNTS AS IT MOVES OVER EXPECT THAT SPRINKLES WILL
BE THE EXTENT OF THE PRECIPITATION.
THE SURFACE PRESSURE GRADIENT TIGHTENS FOR A WHILE THIS MORNING
AND THE WINDS AT 850MB ARE 25 TO 35 KTS DURING THE MORNING AND
INTO THE AFTERNOON HOURS. EXPECT THERE TO BE BREEZY CONDITIONS
DURING THE LATE MORNING INTO EARLY AFTERNOON BEFORE WINDS DIMINISH
AS THE SUN GOES DOWN THIS AFTERNOON. CLOUDS WILL BE MORE PREVALENT
IN THE NORTHEAST PART OF THE FORECAST AREA AND WILL KEEP
TEMPERATURES ON THE LOWER SIDE WHILE A LITTLE MORE SUN AND WARMER
TEMPERATURES ALOFT WILL ALLOW FOR SOME WARMER TEMPERATURES IN THE
SOUTHWEST.
SOME CLOUD COVER WILL CONTINUE ACROSS THE AREA THROUGH THE NIGHT
TONIGHT...BUT DESPITE THE CLOUDS TEMPERATURES ACROSS THE AREA WILL
BE COOLER THAN TONIGHT AS THE WIND DIMINISHES AND A FEW BREAKS IN
THE CLOUDS MOVE THROUGH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 425 AM CDT TUE OCT 22 2013
BIGGEST CHALLENGE WILL BE DETERMINING TEMPERATURES.
THE LONG TERM MODELS CONTINUE TO FORECAST NORTHWEST FLOW AT THE
BEGINNING OF THE LONG TERM FORECAST AS WE WILL BE SITUATED BETWEEN A
BROAD SYNOPTIC LONGWAVE TROUGH TO THE EAST AND A RIDGE ALONG THE
WEST COAST...WITH AN EMBEDDED CUTOFF LOW OFF THE SOUTHERN CALIFORNIA
COAST. THE UPPER LEVEL PATTERN WILL BE HIGHLY AMPLIFIED TO BEGIN THE
LONG TERM.
THERE COULD BE JUST ENOUGH INFLUENCE LEFT FROM A SHORTWAVE TROUGH
FORECAST TO GIVE US A SHOT AT SOME LIGHT PRECIPITATION IN OUR FAR
NORTHEAST AS THE SHORTWAVE TROUGH DEPARTS TO THE SOUTHEAST. THIS SEEMS
TO BE A NEAR COPY OF WHAT HAS HAPPENED OVERNIGHT AND INTO THIS
MORNING...EXCEPT ENERGY WILL BE A BIT FARTHER TO THE
EAST...LESSENING OUR CHANCES OF MUCH PRECIPITATION AND HAVE KEPT IT
OUT OF THE FORECAST...ANTICIPATING THAT ANY PRECIPITATION WILL BE
JUST TO THE EAST. MODELS INDICATE CONSIDERABLE HEIGHT RISES BEHIND
THE COLD FRONT ASSOCIATED WITH THE AFOREMENTIONED WAVE AND I HAVE
INCREASED WIND SPEEDS ACCORDINGLY. FOR THE MOST PART...I KEPT HIGH
TEMPERATURES CLOSE TO PREVIOUS FORECASTS. I HAVE LOWERED
TEMPERATURES A FEW DEGREES FOR WEDNESDAY NIGHT AS SKY COVER SHOULD
BE RELATIVELY SCANT AND WIND SPEEDS SLACKEN. THIS COULD BE THE FIRST
HARD FREEZE FOR MANY AREAS OF THE CWA. ALSO...THURSDAY NIGHT COULD
BE TRICKY FOR LOW TEMPERATURES AS RETURN FLOW COULD CAUSE
TEMPERATURES TO STEADY OUT OR EVEN RISE BY OVERNIGHT...ESPECIALLY
SOUTHWEST. IN FACT...OUR SOUTHWEST MAY NOT COOL THAT MUCH AT ALL AS
WARM AIR ADVECTION TAKES OVER THERE FIRST. AS A RESULT...LOW
TEMPERATURES HAVE BEEN RAISED IN OUR FAR SOUTHWEST TO THE MID 30S TO
NEAR 40...WHILE CENTRAL AND EASTERN AREAS WILL HAVE LOWS IN THE MID
TO UPPER 20S...AND AGAIN...WITH TEMPERATURES BECOME STEADY OR SLOWLY
RISING BY THE OVERNIGHT HOURS.
TEMPERATURES WILL BE RATHER SEASONABLE FOR THE MOST PART FOR THE
REST OF THE LONG TERM. FRIDAY NIGHT LOOKS LIKE THE WARMEST BEFORE
ANOTHER COOL SHOT OF AIR COMES IN WITH ANOTHER WAVE. PATTERN STILL
SHOULD BECOME MORE QUASI-ZONAL BY SUNDAY...AS MODELS HAVE BEEN
ADVERTISING FOR AWHILE. THIS IS A RESULT OF A MORE SIGNIFICANT
SHORTWAVE TROUGH ENTERING THE PACIFIC NORTHWEST. THERE COULD BE A
NOTICEABLE WARM-UP IN ADVANCE OF THIS WAVE...BUT I AM GETTING MIXED
SIGNALS FROM OPERATION AND ENSEMBLE PREDICTIONS AND I FIND IT BEST
TO STICK WITH THE INITIAL ALLBLEND GRIDS. THE FORECAST ESSENTIALLY
STAYS DRY THROUGH MONDAY AS TIMING OF THIS WAVE STILL KEEPS IT FAR
ENOUGH AWAY TO BRING IN MUCH PRECIPITATION TO OUR AREA AND A COLD
FRONT SHOULD BE FAR ENOUGH EAST TO KEEP ANYTHING THAT DEVELOPS ALONG
IT TO OUR EAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1225 AM CDT TUE OCT 22 2013
LOW TO MID LEVEL CLOUDS WILL MOVE THROUGH THE KGRI TERMINAL AREA
THROUGH THE PERIOD. CEILINGS SHOULD REMAIN VFR. THE MAIN QUESTION
IS WHETHER THE LIGHT SHOWERS OR SPRINKLES WILL FALL AT THE KGRI
TERMINAL. THERE ARE A FEW OUT THERE EARLY THIS MORNING AND THERE
COULD BE A FEW DROPS THAT FALL...BUT THAT WOULD BE THE MOST. WINDS
WILL BE GUSTY DURING THE MORNING BUT START TO DIMINISH DURING THE
LATE AFTERNOON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...HEINLEIN
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
305 AM EDT TUE OCT 22 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL TRACK INTO QUEBEC
TONIGHT. SHOWERS WILL ACCOMPANY A COLD FRONT MOVING THROUGH THE
AREA EARLY TUESDAY MORNING. BEHIND THE FRONT MUCH COLDER AIR WILL
SPREAD OVER THE NORTHEAST FOR THE REMAINDER OF THE WEEK. CLOUDY
AND SHOWERY CONDITIONS CAN BE EXPECTED...WITH LAKE EFFECT RAIN
MIXING WITH SNOW OVER THE HIGHER TERRAIN IN NORTH CENTRAL NEW
YORK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1230 AM UPDATE...SFC COLD FRONT JUST WEST OF BUFFALO WITH LEADING
EDGE OF SHOWERS REACHING THE GENESEE VALLEY ATTM. BASED ON CURRENT
RADAR TRENDS AND LATEST MODEL GUIDANCE SLOWED SHOWERS MOVING INTO
REGION BY 2-3 HOURS. SHOWERS WILL REACH WESTERN FA BY 07Z-08Z,
CENTRAL FA 10Z-12Z AND EASTERN SECTIONS 12Z-14Z. WILL CONTINUE
WITH LIKELY/CAT POPS FOR MUCH OF CENTRAL NY AND CHC/SLIGHT CHC FOR
NE PA.
715 PM UPDATE...
NO CHGS NEEDED TO GRIDS AT THIS TIME. SFC LOPRES TRACKING ACRS
SRN ONTARIO AT THIS TIME WITH ATTENDANT CDFNT DRAPED ACRS OHIO.
PCPN IS SLOWLY TREKING EAST ALONG IT. LATEST RUN OF HRRR AND HIRES
NMM INDICATES THIS LINE OF PCPN SHUD NOT HIT WRN ZONES UNTIL AFT
06Z AND MAY NEED TO ADJUST TIMING BACK BY AN HR OR TWO BUT WL WAIT
UNTIL NEXT UPDATE. OVRNGT MINS LOOK TO BE REASONABLE WITH HRLY
TEMPS RIGHT ON TARGET AT THIS TIME.
PREV DISCUSSION BLO...
BROAD SOUTHWEST FLOW AHEAD OF A CLOSED LOW MOVING ACROSS SOUTHERN
CANADA WILL CONTINUE THROUGH THIS EVENING. A SURFACE COLD FRONT
APPROACHING FROM THE WESTERN LAKES LOOKS TO MOVE INTO THE REGION
VERY LATE IN THIS PERIOD. THE MAIN FOCUS TO FORECAST ADJUSTMENTS
IS TO GRADUALLY SLOW THE ONSET OF RAINFALL WITH THIS FEATURE AS
THE PATTERN IS SUGGESTING MAINLY ANA-FRONTAL CHARACTERISTICS WITH
PRECIP MAINLY ALONG AND BEHIND THE FRONT AS SUPPORTING ENERGY
ALOFT RIDES PARALLEL TO THE BOUNDARY. THE PREVIOUS FORECAST WAS
HANDLING THIS TREND WELL...SO ONLY MADE AN HOUR OR TWO TIMING
ADJUSTMENT. GIVEN THE INCRG CLOUDS AND MIXING FROM AN ACTIVE WIND
FIELD...THE TEMPS SHOULD REMAIN FAIRLY MILD OVERNIGHT IN THE 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE PERIOD OF RAINFALL ASSOCIATED WITH THE FRONTAL PASSAGE LOOKS
TO BE FAIRLY BRIEF FOR ANY ONE LOCATION WITH ABOUT 2-4 HOURS WORTH
OF RAIN EARLY TUESDAY MORNING BEFORE THE FRONT SWEEPS EAST WITH
SINKING MOTION AND DRYING WORKING ACROSS THE AREA DURING BY EARLY
AFTERNOON. AS THE FRONT MAKES IT/S WAY EAST...WE HAVE NOTED TRENDS
IN THE SYSTEM WEAKENING AS IT MOVES FROM THE FINGER LAKES TO THE
CATSKILLS. IN ADDITION TO QUICKLY MOVING POP TRENDS ACROSS THE
AREA...WILL ALSO DIMINISH THE CHANCES WITH TIME AND IN
FACT...THERE LOOKS TO BE VERY LITTLE ASIDE FROM SCATTERED ACTIVITY
OVER OUR SOUTHERN ZONES. ALSO...WITH THE FLOW SHIFTING TO THE
WSW-W...THERE MAY EVEN BE A FAIR AMOUNT OF BREAKS IN THE CLOUDS
DEVELOPING WITH AREAS OF SUNSHINE DURING THE LATTER PART OF THE DAY.
FROM TUESDAY NIGHT THROUGH THURSDAY...THE PATTERN REMAINS VERY
ACTIVE WITH THE ATMOSPHERE ALSO COOLING AND BECOMING CONDITIONALLY
UNSTABLE TO LAKE EFFECT THRESHOLDS. TEMPERATURES LOOK TO BE
BRIEFLY BELOW NORMAL WITH HIGHS POSSIBLY NOT CLIMBING OUT OF THE
40S ON WEDS-THURS. INITIALLY...ANY LAKE DEVELOPMENT OF SHOWERS OR
FLURRIES WILL REMAIN TO OUR NORTH ON TUESDAY NIGHT...BUT SHIFTING
FLOW TO THE WEST AND NORTHWEST BEGINS TO TARGET OUR NORTHERN
COUNTIES AS WE HEAD INTO WEDNESDAY THROUGH THURSDAY. THE PASSAGE
OF SEVERAL WAVES UP UPPER ENERGY WILL CAUSE FLUCTUATIONS IN THE
BOUNDARY LAYER STEERING FLOW WITH ANY BANDING OF RAIN/SNOW SHOWERS
OSCILLATING ACROSS THE EASTERN LAKES AND MOHAWK VALLEY.
MUCH OF THE PRECIPITATION THAT FALLS IS FORECAST TO BE LIGHT
ACROSS THE REGION WITH AMOUNTS GENERALLY SUFFICIENT TO MAINLY
WETTING THE PAVEMENT. ORGANIZED BANDS EAST OF THE LAKES COULD
CONTRIBUTE TO A BIT MORE. BOUNDARY LAYER...AND SURFACE TEMPERATURES
LATER WEDNESDAY NIGHT MAY BE SUFFICIENT FOR THE FIRST MINOR SNOW
ACCUMULATIONS OF THE SEASON WHICH WOULD BE AT ELEVATIONS SUCH AS
THE TUG HILL OR TULLY-HEIBERGS OF CNY. EARLY THOUGHTS ON THIS
RIGHT NOW SUGGEST AN INCH OR LESS ON GRASSY SURFACES BY THURSDAY
MORNING. ELSEWHERE...GENERALLY RAIN SHOWERS CAN BE EXPECTED FROM
TIME TO TIME WITH WET FLAKES MIXED IN ACROSS CNY AND NORTHERN PA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
3 AM UPDATE...
GRIDS ADJUSTED TO ACCOUNT FOR WPC AND MODEL TRENDS. LITTLE CHANGE.
UPPER TROUGH PATTERN LATE WEEK INTO WEEKEND...LOOKS TO SHIFT
TEMPORARILY INTO A FLATTER W OR WSW FLOW ALOFT BY EARLY NEXT WEEK.
THIS WILL ALLOW TEMPERATURES TO EDGE UP CLOSER TO CLIMATOLOGY...AND
A BREAK IN PRECIPITATION CHANCES SUNDAY NIGHT THROUGH AT LEAST
MONDAY NIGHT. UNTIL THEN...UNSETTLED CHILLY CYCLONIC FLOW WITH
GREAT LAKES HELPING TO YIELD SCATTERED -SHRA/-SHSN MAINLY IN
CENTRAL NY.
PREVIOUS DISCUSSION...
LTL CHG TO PREV FCST WITH UNSETTLED AND MUCH COOLER CONDITIONS DUE
TO LAKE EFFECT SHRA/SHSN AND PASSING S/WV`S OR CLIPPER TYPE
SYSTEMS. UPR HGTS BEGIN TO RISE LATE IN THE PD AS SFC HI PRES BUILDS
IN FROM THE OH VLY OFFERING HOPE FOR SOME RELIEF BY MON. TIMING
OF THE WAVES AND LOW LVL FLOW ORIENTATION FOR LE PCPN TUFF TO
PINPOINT AT THIS TIME FRAME BUT THERE APPEARS TO BE SOME AGREEMENT
THAT LOW LVL FLOW WILL BGM MORE NWLY ON FRI...ALLOWING ACTIVITY TO
DROP SWD INTO CNTRL NY. USED WPC MED RNG GDNC AS A START...WITH
SOME ENHANCEMENTS TO CLD/POP GRIDS MAINLY DAYS 4-5.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
06Z UPDATE...
MAIN WEATHER FEATURE OF INTEREST IS A COLD FRONT SET TO MOVE WEST
TO EAST ACROSS THE TERMINALS 10Z-15Z...AND A VFR CIG HAS ALREADY
FORMED AHEAD OF IT. FRONT WILL COME THROUGH WITH LIMITED
MOISTURE...THUS ONLY KNOCKING TERMINALS /EXCEPT KAVP/ DOWN
TEMPORARILY INTO MVFR WITH FRONTAL PASSAGE AND LIGHT SHOWERS. SEE
TAFS FOR SPECIFIC TIMING. BRIEF FUEL ALTERNATE MVFR ALSO POSSIBLE
HILLTOP TERMINALS KBGM-KITH. WINDS TO VEER FROM S-SSW TO W-WNW AS
FRONT PASSES. 4-5 KFT AGL CIG LATE MORNING-EARLY AFTERNOON...THEN
DRYNESS OF AIR MASS WILL SCATTER THINGS OUT BY LATE AFTERNOON INTO
EVENING.
OUTLOOK...
LATE TUE NGT...VFR.
WED/THU/FRI/SAT...TIMES OF MVFR CIGS AND SCT -SHRA MAINLY CENTRAL
NY TERMINALS WITH MOISTURE OFF OF GREAT LAKES. -SHSN MAY MIX IN AT
TIMES LATE NIGHT-EARLY MORNING.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JAB
NEAR TERM...JAB/PVN/RRM
SHORT TERM...JAB
LONG TERM...MDP
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
149 AM EDT TUE OCT 22 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL TRACK INTO QUEBEC
TONIGHT. SHOWERS WILL ACCOMPANY A COLD FRONT MOVING THROUGH THE
AREA EARLY TUESDAY MORNING. BEHIND THE FRONT MUCH COLDER AIR WILL
SPREAD OVER THE NORTHEAST FOR THE REMAINDER OF THE WEEK. CLOUDY
AND SHOWERY CONDITIONS CAN BE EXPECTED...WITH LAKE EFFECT RAIN
MIXING WITH SNOW OVER THE HIGHER TERRAIN IN NORTH CENTRAL NEW
YORK.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...SFC COLD FRONT JUST WEST OF BUFFALO WITH LEADING
EDGE OF SHOWERS REACHING THE GENESEE VALLEY ATTM. BASED ON CURRENT
RADAR TRENDS AND LATEST MODEL GUIDANCE SLOWED SHOWERS MOVING INTO
REGION BY 2-3 HOURS. SHOWERS WILL REACH WESTERN FA BY 07Z-08Z,
CENTRAL FA 10Z-12Z AND EASTERN SECTIONS 12Z-14Z. WILL CONTINUE
WITH LIKELY/CAT POPS FOR MUCH OF CENTRAL NY AND CHC/SLIGHT CHC FOR
NE PA.
715 PM UPDATE...
NO CHGS NEEDED TO GRIDS AT THIS TIME. SFC LOPRES TRACKING ACRS
SRN ONTARIO AT THIS TIME WITH ATTENDANT CDFNT DRAPED ACRS OHIO.
PCPN IS SLOWLY TREKING EAST ALONG IT. LATEST RUN OF HRRR AND HIRES
NMM INDICATES THIS LINE OF PCPN SHUD NOT HIT WRN ZONES UNTIL AFT
06Z AND MAY NEED TO ADJUST TIMING BACK BY AN HR OR TWO BUT WL WAIT
UNTIL NEXT UPDATE. OVRNGT MINS LOOK TO BE REASONABLE WITH HRLY
TEMPS RIGHT ON TARGET AT THIS TIME.
PREV DISCUSSION BLO...
BROAD SOUTHWEST FLOW AHEAD OF A CLOSED LOW MOVING ACROSS SOUTHERN
CANADA WILL CONTINUE THROUGH THIS EVENING. A SURFACE COLD FRONT
APPROACHING FROM THE WESTERN LAKES LOOKS TO MOVE INTO THE REGION
VERY LATE IN THIS PERIOD. THE MAIN FOCUS TO FORECAST ADJUSTMENTS
IS TO GRADUALLY SLOW THE ONSET OF RAINFALL WITH THIS FEATURE AS
THE PATTERN IS SUGGESTING MAINLY ANA-FRONTAL CHARACTERISTICS WITH
PRECIP MAINLY ALONG AND BEHIND THE FRONT AS SUPPORTING ENERGY
ALOFT RIDES PARALLEL TO THE BOUNDARY. THE PREVIOUS FORECAST WAS
HANDLING THIS TREND WELL...SO ONLY MADE AN HOUR OR TWO TIMING
ADJUSTMENT. GIVEN THE INCRG CLOUDS AND MIXING FROM AN ACTIVE WIND
FIELD...THE TEMPS SHOULD REMAIN FAIRLY MILD OVERNIGHT IN THE 40S.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
THE PERIOD OF RAINFALL ASSOCIATED WITH THE FRONTAL PASSAGE LOOKS
TO BE FAIRLY BRIEF FOR ANY ONE LOCATION WITH ABOUT 2-4 HOURS WORTH
OF RAIN EARLY TUESDAY MORNING BEFORE THE FRONT SWEEPS EAST WITH
SINKING MOTION AND DRYING WORKING ACROSS THE AREA DURING BY EARLY
AFTERNOON. AS THE FRONT MAKES IT/S WAY EAST...WE HAVE NOTED TRENDS
IN THE SYSTEM WEAKENING AS IT MOVES FROM THE FINGER LAKES TO THE
CATSKILLS. IN ADDITION TO QUICKLY MOVING POP TRENDS ACROSS THE
AREA...WILL ALSO DIMINISH THE CHANCES WITH TIME AND IN
FACT...THERE LOOKS TO BE VERY LITTLE ASIDE FROM SCATTERED ACTIVITY
OVER OUR SOUTHERN ZONES. ALSO...WITH THE FLOW SHIFTING TO THE
WSW-W...THERE MAY EVEN BE A FAIR AMOUNT OF BREAKS IN THE CLOUDS
DEVELOPING WITH AREAS OF SUNSHINE DURING THE LATTER PART OF THE DAY.
FROM TUESDAY NIGHT THROUGH THURSDAY...THE PATTERN REMAINS VERY
ACTIVE WITH THE ATMOSPHERE ALSO COOLING AND BECOMING CONDITIONALLY
UNSTABLE TO LAKE EFFECT THRESHOLDS. TEMPERATURES LOOK TO BE
BRIEFLY BELOW NORMAL WITH HIGHS POSSIBLY NOT CLIMBING OUT OF THE
40S ON WEDS-THURS. INITIALLY...ANY LAKE DEVELOPMENT OF SHOWERS OR
FLURRIES WILL REMAIN TO OUR NORTH ON TUESDAY NIGHT...BUT SHIFTING
FLOW TO THE WEST AND NORTHWEST BEGINS TO TARGET OUR NORTHERN
COUNTIES AS WE HEAD INTO WEDNESDAY THROUGH THURSDAY. THE PASSAGE
OF SEVERAL WAVES UP UPPER ENERGY WILL CAUSE FLUCTUATIONS IN THE
BOUNDARY LAYER STEERING FLOW WITH ANY BANDING OF RAIN/SNOW SHOWERS
OSCILLATING ACROSS THE EASTERN LAKES AND MOHAWK VALLEY.
MUCH OF THE PRECIPITATION THAT FALLS IS FORECAST TO BE LIGHT
ACROSS THE REGION WITH AMOUNTS GENERALLY SUFFICIENT TO MAINLY
WETTING THE PAVEMENT. ORGANIZED BANDS EAST OF THE LAKES COULD
CONTRIBUTE TO A BIT MORE. BOUNDARY LAYER...AND SURFACE TEMPERATURES
LATER WEDNESDAY NIGHT MAY BE SUFFICIENT FOR THE FIRST MINOR SNOW
ACCUMULATIONS OF THE SEASON WHICH WOULD BE AT ELEVATIONS SUCH AS
THE TUG HILL OR TULLY-HEIBERGS OF CNY. EARLY THOUGHTS ON THIS
RIGHT NOW SUGGEST AN INCH OR LESS ON GRASSY SURFACES BY THURSDAY
MORNING. ELSEWHERE...GENERALLY RAIN SHOWERS CAN BE EXPECTED FROM
TIME TO TIME WITH WET FLAKES MIXED IN ACROSS CNY AND NORTHERN PA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LTL CHG TO PREV FCST WITH UNSETTLED AND MUCH COOLER CONDITIONS DUE
TO LAKE EFFECT SHRA/SHSN AND PASSING S/WV`S OR CLIPPER TYPE
SYSTEMS. UPR HGTS BEGIN TO RISE LATE IN THE PD AS SFC HI PRES BUILDS
IN FROM THE OH VLY OFFERING HOPE FOR SOME RELIEF BY MON. TIMING
OF THE WAVES AND LOW LVL FLOW ORIENTATION FOR LE PCPN TUFF TO
PINPOINT AT THIS TIME FRAME BUT THERE APPEARS TO BE SOME AGREEMENT
THAT LOW LVL FLOW WILL BGM MORE NWLY ON FRI...ALLOWING ACTIVITY TO
DROP SWD INTO CNTRL NY. USED WPC MED RNG GDNC AS A START...WITH
SOME ENHANCEMENTS TO CLD/POP GRIDS MAINLY DAYS 4-5.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
06Z UPDATE...
MAIN WEATHER FEATURE OF INTEREST IS A COLD FRONT SET TO MOVE WEST
TO EAST ACROSS THE TERMINALS 10Z-15Z...AND A VFR CIG HAS ALREADY
FORMED AHEAD OF IT. FRONT WILL COME THROUGH WITH LIMITED
MOISTURE...THUS ONLY KNOCKING TERMINALS /EXCEPT KAVP/ DOWN
TEMPORARILY INTO MVFR WITH FRONTAL PASSAGE AND LIGHT SHOWERS. SEE
TAFS FOR SPECIFIC TIMING. BRIEF FUEL ALTERNATE MVFR ALSO POSSIBLE
HILLTOP TERMINALS KBGM-KITH. WINDS TO VEER FROM S-SSW TO W-WNW AS
FRONT PASSES. 4-5 KFT AGL CIG LATE MORNING-EARLY AFTERNOON...THEN
DRYNESS OF AIR MASS WILL SCATTER THINGS OUT BY LATE AFTERNOON INTO
EVENING.
OUTLOOK...
LATE TUE NGT...VFR.
WED/THU/FRI/SAT...TIMES OF MVFR CIGS AND SCT -SHRA MAINLY CENTRAL
NY TERMINALS WITH MOISTURE OFF OF GREAT LAKES. -SHSN MAY MIX IN AT
TIMES LATE NIGHT-EARLY MORNING.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JAB
NEAR TERM...JAB/PVN/RRM
SHORT TERM...JAB
LONG TERM...
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1232 AM EDT TUE OCT 22 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL TRACK INTO QUEBEC
TONIGHT. SHOWERS WILL ACCOMPANY A COLD FRONT MOVING THROUGH THE
AREA EARLY TUESDAY MORNING. BEHIND THE FRONT MUCH COLDER AIR WILL
SPREAD OVER THE NORTHEAST FOR THE REMAINDER OF THE WEEK. CLOUDY
AND SHOWERY CONDITIONS CAN BE EXPECTED...WITH LAKE EFFECT RAIN
MIXING WITH SNOW OVER THE HIGHER TERRAIN IN NORTH CENTRAL NEW
YORK.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...SFC COLD FRONT JUST WEST OF BUFFALO WITH LEADING
EDGE OF SHOWERS REACHING THE GENESEE VALLEY ATTM. BASED ON CURRENT
RADAR TRENDS AND LATEST MODEL GUIDANCE SLOWED SHOWERS MOVING INTO
REGION BY 2-3 HOURS. SHOWERS WILL REACH WESTERN FA BY 07Z-08Z,
CENTRAL FA 10Z-12Z AND EASTERN SECTIONS 12Z-14Z. WILL CONTINUE
WITH LIKELY/CAT POPS FOR MUCH OF CENTRAL NY AND CHC/SLIGHT CHC FOR
NE PA.
715 PM UPDATE...
NO CHGS NEEDED TO GRIDS AT THIS TIME. SFC LOPRES TRACKING ACRS
SRN ONTARIO AT THIS TIME WITH ATTENDANT CDFNT DRAPED ACRS OHIO.
PCPN IS SLOWLY TREKING EAST ALONG IT. LATEST RUN OF HRRR AND HIRES
NMM INDICATES THIS LINE OF PCPN SHUD NOT HIT WRN ZONES UNTIL AFT
06Z AND MAY NEED TO ADJUST TIMING BACK BY AN HR OR TWO BUT WL WAIT
UNTIL NEXT UPDATE. OVRNGT MINS LOOK TO BE REASONABLE WITH HRLY
TEMPS RIGHT ON TARGET AT THIS TIME.
PREV DISCUSSION BLO...
BROAD SOUTHWEST FLOW AHEAD OF A CLOSED LOW MOVING ACROSS SOUTHERN
CANADA WILL CONTINUE THROUGH THIS EVENING. A SURFACE COLD FRONT
APPROACHING FROM THE WESTERN LAKES LOOKS TO MOVE INTO THE REGION
VERY LATE IN THIS PERIOD. THE MAIN FOCUS TO FORECAST ADJUSTMENTS
IS TO GRADUALLY SLOW THE ONSET OF RAINFALL WITH THIS FEATURE AS
THE PATTERN IS SUGGESTING MAINLY ANA-FRONTAL CHARACTERISTICS WITH
PRECIP MAINLY ALONG AND BEHIND THE FRONT AS SUPPORTING ENERGY
ALOFT RIDES PARALLEL TO THE BOUNDARY. THE PREVIOUS FORECAST WAS
HANDLING THIS TREND WELL...SO ONLY MADE AN HOUR OR TWO TIMING
ADJUSTMENT. GIVEN THE INCRG CLOUDS AND MIXING FROM AN ACTIVE WIND
FIELD...THE TEMPS SHOULD REMAIN FAIRLY MILD OVERNIGHT IN THE 40S.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
THE PERIOD OF RAINFALL ASSOCIATED WITH THE FRONTAL PASSAGE LOOKS
TO BE FAIRLY BRIEF FOR ANY ONE LOCATION WITH ABOUT 2-4 HOURS WORTH
OF RAIN EARLY TUESDAY MORNING BEFORE THE FRONT SWEEPS EAST WITH
SINKING MOTION AND DRYING WORKING ACROSS THE AREA DURING BY EARLY
AFTERNOON. AS THE FRONT MAKES IT/S WAY EAST...WE HAVE NOTED TRENDS
IN THE SYSTEM WEAKENING AS IT MOVES FROM THE FINGER LAKES TO THE
CATSKILLS. IN ADDITION TO QUICKLY MOVING POP TRENDS ACROSS THE
AREA...WILL ALSO DIMINISH THE CHANCES WITH TIME AND IN
FACT...THERE LOOKS TO BE VERY LITTLE ASIDE FROM SCATTERED ACTIVITY
OVER OUR SOUTHERN ZONES. ALSO...WITH THE FLOW SHIFTING TO THE
WSW-W...THERE MAY EVEN BE A FAIR AMOUNT OF BREAKS IN THE CLOUDS
DEVELOPING WITH AREAS OF SUNSHINE DURING THE LATTER PART OF THE DAY.
FROM TUESDAY NIGHT THROUGH THURSDAY...THE PATTERN REMAINS VERY
ACTIVE WITH THE ATMOSPHERE ALSO COOLING AND BECOMING CONDITIONALLY
UNSTABLE TO LAKE EFFECT THRESHOLDS. TEMPERATURES LOOK TO BE
BRIEFLY BELOW NORMAL WITH HIGHS POSSIBLY NOT CLIMBING OUT OF THE
40S ON WEDS-THURS. INITIALLY...ANY LAKE DEVELOPMENT OF SHOWERS OR
FLURRIES WILL REMAIN TO OUR NORTH ON TUESDAY NIGHT...BUT SHIFTING
FLOW TO THE WEST AND NORTHWEST BEGINS TO TARGET OUR NORTHERN
COUNTIES AS WE HEAD INTO WEDNESDAY THROUGH THURSDAY. THE PASSAGE
OF SEVERAL WAVES UP UPPER ENERGY WILL CAUSE FLUCTUATIONS IN THE
BOUNDARY LAYER STEERING FLOW WITH ANY BANDING OF RAIN/SNOW SHOWERS
OSCILLATING ACROSS THE EASTERN LAKES AND MOHAWK VALLEY.
MUCH OF THE PRECIPITATION THAT FALLS IS FORECAST TO BE LIGHT
ACROSS THE REGION WITH AMOUNTS GENERALLY SUFFICIENT TO MAINLY
WETTING THE PAVEMENT. ORGANIZED BANDS EAST OF THE LAKES COULD
CONTRIBUTE TO A BIT MORE. BOUNDARY LAYER...AND SURFACE TEMPERATURES
LATER WEDNESDAY NIGHT MAY BE SUFFICIENT FOR THE FIRST MINOR SNOW
ACCUMULATIONS OF THE SEASON WHICH WOULD BE AT ELEVATIONS SUCH AS
THE TUG HILL OR TULLY-HEIBERGS OF CNY. EARLY THOUGHTS ON THIS
RIGHT NOW SUGGEST AN INCH OR LESS ON GRASSY SURFACES BY THURSDAY
MORNING. ELSEWHERE...GENERALLY RAIN SHOWERS CAN BE EXPECTED FROM
TIME TO TIME WITH WET FLAKES MIXED IN ACROSS CNY AND NORTHERN PA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LTL CHG TO PREV FCST WITH UNSETTLED AND MUCH COOLER CONDITIONS DUE
TO LAKE EFFECT SHRA/SHSN AND PASSING S/WV`S OR CLIPPER TYPE
SYSTEMS. UPR HGTS BEGIN TO RISE LATE IN THE PD AS SFC HI PRES BUILDS
IN FROM THE OH VLY OFFERING HOPE FOR SOME RELIEF BY MON. TIMING
OF THE WAVES AND LOW LVL FLOW ORIENTATION FOR LE PCPN TUFF TO
PINPOINT AT THIS TIME FRAME BUT THERE APPEARS TO BE SOME AGREEMENT
THAT LOW LVL FLOW WILL BGM MORE NWLY ON FRI...ALLOWING ACTIVITY TO
DROP SWD INTO CNTRL NY. USED WPC MED RNG GDNC AS A START...WITH
SOME ENHANCEMENTS TO CLD/POP GRIDS MAINLY DAYS 4-5.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
00Z UPDATE...
VFR CONDITIONS WILL PREVAIL THROUGH THE EARLY EVENING AHEAD OF AN
APPROACHING COLD FRONT FROM THE WEST. WINDS WILL WEAKEN QUICKLY
AFTER SUNSET AS WE LOSE MIXING FROM THE SUN AND REMAIN UNDER 12
KNOTS. THE COLD FRONT WILL MOVE FROM W TO E EARLY TUESDAY MORNING
FORCING THE WINDS TO TRANSITION FROM A SOUTHERLY FLOW TO A
WEST/NORTHWESTERLY FLOW. LIGHT RAIN SHOWERS WILL ACCOMPANY THIS
FRONT AND CAUSE RESTRICTIONS OF MVFR CIGS AND VISBYS AT KRME...
KSYR... AND KITH THROUGH 15Z TUESDAY MORNING. THE REMAINING TAFS
SITES ARE EXPECTED TO REMAIN VFR AS THE FRONT PASSES WITH LIGHT RAIN
SHOWERS. WINDS TUESDAY AFTERNOON WILL PICK UP CAUSING LINGERING MVFR
CIGS TO LIFT TO VFR.
OUTLOOK...
TUE NGT...VFR.
WED/THU/FRI/SAT...MVFR AND OCNL IFR IN -SHRA/-SHSN....MAINLY ACRS CNTRL
NY AFFECTING RME/SYR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JAB
NEAR TERM...JAB/PVN/RRM
SHORT TERM...JAB
LONG TERM...
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1025 PM EDT WED OCT 23 2013
.SYNOPSIS...
COOLER AIR IS ON THE WAY AS ANOTHER COLD FRONT APPROACHES THE REGION
AND PUSHES OFF THE COAST FRIDAY MORNING. BELOW NORMAL TEMPERATURES
ARE EXPECTED THROUGH THE WEEKEND...AND THE FIRST FROST OR FREEZE OF
THE SEASON COULD OCCUR FRIDAY NIGHT INTO EARLY SATURDAY MORNING. A
SLOW WARMING TREND WILL BEGIN SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM WEDNESDAY...A BROAD UPPER TROUGH COVERS THE EASTERN
HALF OF THE NATION THIS EVENING. THE COOLEST AIRMASS OF THIS FALL
SEASON IS SPREADING DOWN TO THE EAST COAST BEACHES...AND WELL-
BELOW NORMAL TEMPERATURES SHOULD CONTINUE INTO SATURDAY. AT THE
SURFACE HIGH PRESSURE IS CENTERED OVER THE WESTERN DAKOTAS BUT
EXTENDS A RIDGE AXIS INTO THE MID-SOUTH REGION.
850 MB TEMPERATURES ARE FALLING RAPIDLY AND SHOULD END UP BETWEEN
+3C AND +7C ACROSS THE AREA BY DAYBREAK THURSDAY. AS THE COLDER AIR
BUILDS IN THERE IS A REGION OF TIGHTENED PRESSURE GRADIENT
DISCERNIBLE ON SURFACE MAPS ACROSS THE INTERIOR COASTAL PLAIN AND
EASTERN PIEDMONT REGION. THIS SHOULD SHIFT TO THE COAST OVER THE
NEXT FEW HOURS THEN OFFSHORE...BRINGING A BRIEF (2-3 HOUR) PERIOD
OF GUSTY WINDS FOLLOWING BY QUICKLY FALLING TEMPERATURES. ALMOST
ALL MODELS SHOW THIS...AND THE LATEST FEW HRRR RUNS SHOW
ANTICIPATED TRENDS WITH WINDS AND TEMPERATURES QUITE WELL.
NO SIGNIFICANT CHANGES HAVE BEEN MADE TO FORECAST LOWS...STILL
EXPECTED TO RANGE FROM THE LOWER 40S ALONG THE COAST TO THE UPPER
30S INLAND. EVEN THOUGH INLAND WINDS SHOULD BECOME RATHER LIGHT (5
MPH OR LESS) LATE...THERE SHOULD BE INSUFFICIENT HUMIDITY TO
PRODUCE FROST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...EARLY ON IN THE SHORT TERM PERIOD A
CONFLUENT H5 PATTERN WILL EXIST ACROSS THE NATION/S MID-SECTION
WITH TROFFING ACROSS THE GREAT LAKES INTO NEW ENGLAND. THE
VORTICITY IN THIS SCENARIO IS HIGHLY CHANNELED...NEVERTHELESS THIS
SETUP WILL LEAD TO ANOTHER REINFORCEMENT OF COOLER/DRIER AIR INTO
THE CAROLINAS BY FRIDAY. TIME HEIGHT CROSS SECTIONS INDICATE A DRY
COLUMN WILL PREVAIL...THE EXCEPTION IS A BRIEF PERIOD OF
INCREASING LOW-LEVEL MOISTURE THURSDAY NIGHT INTO FRIDAY MORNING.
THIS INCREASE IN MOISTURE IS LIKELY IN RESPONSE TO BACKING LOW-
LEVEL WINDS JUST AHEAD OF THE NEXT FRONT/SURGE. BY FRIDAY
AFTERNOON EXPECT CLEAR SKIES...AND A DECOUPLED WIND FIELD BY
FRIDAY EVENING WHICH WILL SET THE STAGE FOR OPTIMAL RADIATIONAL
COOLING. THE TYPICAL COOL SPOTS WILL LIKELY DROP TO AT OR BELOW
FREEZING DURING THIS TIME FRAME...WITH MID 30S EXPECTED MOST OTHER
LOCATIONS (UPPER 30S TO AROUND 40 AT THE COAST). THESE ARE THE
COOLEST TEMPERATURES THUS FAR THIS FALL...AND FROST IS ALSO A
POSSIBILITY...ESPECIALLY AWAY FROM THE WARMER COAST. OVERALL
DURING FRIDAY NIGHT THE MIN TEMPERATURES WILL BE WELL BELOW
CLIMATOLOGY...WHICH ARE UPPER 40S THIS TIME OF YEAR.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...LOW LEVEL THERMAL TROUGH/COLD AIR TONGUE
CROSSES THE REGION ON SATURDAY...850MB TEMPS GENERALLY ABOUT 2-3C TO
START THE DAY. WARM AIR ADVECTION THROUGH THE AFTERNOON WARMS THE
LAYER TO 6-7C. AT THE SURFACE HOWEVER HIGH PRESSURE HANGS ON LONG
ENOUGH TO KEEP WINDS LIGHT AND VARIABLE ENOUGH TO KEEP THESE TEMPS
FROM MIXING TO THE SURFACE AND ANOTHER VERY CHILLY DAY EXPECTED. THE
OVERALL HIGHER THETA AIR WILL BE REALIZED AT THE SURFACE SATURDAY
NIGHT THOUGH AS LOWS SHOULD BE CLOSE TO 40...NOT AS CHILLY AS THE
PRIOR TWO BUT STILL A GOOD 10-15 BELOW CLIMO. A LIGHT SOUTH WIND
DEVELOPS ON SUNDAY AND THERE SHOULD BE DEEPER MIXING ALLOWING FOR
HIGHS MUCH CLOSER TO BUT STILL A LITTLE SHY OF NORMAL. A DISSIPATING
BACKDOOR COLD FRONT WILL SLIP THROUGH LATE SUNDAY WITH FAR TOO
LITTLE MOISTURE TO WORK WITH TO CAUSE MUCH MORE THAN JUST A WIND
SHIFT. FOR THE REMAINDER OF THE PERIOD MID LEVEL FLOW WILL BE NEARLY
ZONAL AND QUITE WEAK AS THE LARGE TROUGHINESS OVER EASTERN CANADA
WEAKENS CONSIDERABLY AND SOME INCREASING AMPLITUDE TAKES SHAPE OUT
WEST...KEEPING OUT WEATHER DRY AND SEASONABLE.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THE FORECAST
PERIOD. CLEAR SKIES OVERNIGHT WITH A RADIATIONAL INVERSION. WINDS
MAY NOT GO COMPLETELY CALM AS THERE WILL BE A LOW LEVEL JET MOVING
THROUGH OVERNIGHT THAT WILL KEEP WINDS AT 5-10KTS. THERE WILL ALSO
BE SOME RENEWED COLD AIR ADVECTION THAT MAY MIX THINGS A BIT.
THURSDAY...LIGHT NORTHWEST FLOW WITH SCATTERED SKIES. A SOUTHWEST
RESULTANT IS POSSIBLE ALONG THE COAST AFTER 18Z.
EXTENDED OUTLOOK...VFR WILL PREVAIL THROUGH THE EXTENDED PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM WEDNESDAY...HIGH PRESSURE CENTERED IN THE WESTERN
DAKOTAS EXTENDS A RIDGE AXIS INTO THE MID-SOUTH REGION...WHILE LOW
PRESSURE WELL OFF THE NEW ENGLAND COAST PUSHES FARTHER OFFSHORE. A
REGION OF STRONG WINDS (25-35 KNOTS) 1000-2000 FEET ABOVE GROUND
LEVEL CURRENTLY EXISTS ACROSS THE EASTERN CAROLINAS...AND SHOULD
PUSH OFFSHORE IN THE NEXT HOUR. SINCE MARINE AIR TEMPERATURES ARE
A GOOD 10 DEGREES WARMER THAN INLAND TEMPERATURES...I ANTICIPATE
THESE STRONGER WINDS TO BE MIXED DOWN TO THE OCEAN SURFACE WITH
SUSTAINED WINDS SOON INCREASING TO 20-25 KNOTS WITH GUSTS NEAR
30 KNOTS.
THE LATEST SEVERAL RUNS OF THE HRRR AND RUC MODELS DEPICT THIS
SURGE OF NORTHWEST WINDS QUITE WELL...AND ARE THE BASIS FOR THIS
UPDATE. I HAVE EXPANDED THE SMALL CRAFT ADVISORY SOUTHWARD TO
INCLUDE ALL OF MY SOUTH CAROLINA WATERS...AND HAVE EXTENDED THE
ENDING TIME OF THE ADVISORY TO 2 A.M. AFTER 2 A.M. WIND SPEEDS
WILL DIMINISH AS WIND DIRECTIONS VEER MORE NORTHERLY. NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO WAVE HEIGHT FORECASTS WHICH
STILL RANGE FROM 2-4 FT ALONG MOST OF THE COAST...EXCEPT FOR AN
AREA OF 5-FOOTERS AWAY FROM SHORE NEAR CAPE FEAR.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...SURGE OF COOL AIR WILL WANE THURSDAY
MORNING AS A SURFACE RIDGE AXIS BUILDS ACROSS THE COASTAL WATERS.
THE RESULT WILL BE A DECREASE IN THE OFFSHORE FLOW BY THE AFTERNOON.
THE NEXT REINFORCING SHOT OF COOL AIR WILL ARRIVE FRIDAY MORNING
ALLOWING THE WINDS TO VEER AROUND TO A NORTHERLY DIRECTION AND
INCREASE AGAIN IN THE WAKE OF THE FRONT. THE OFFSHORE FLOW WILL
CREATE A FETCH LIMITATION IN THE LOCAL WAVE GROWTH THUS A RANGE OF
SEAS WILL EXIST THROUGH MUCH OF THE SHORT TERM PERIOD.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE BUILDS IN ON SATURDAY
BRINGING A MUCH DECREASING WIND AND POSSIBLY SOME LATE DAY
VARIABILITY IN THE OTHERWISE NORTHERLY FLOW. THE CENTER OF THE HIGH
SHIFTS WESTWARD AS IT WEAKENS SATURDAY NIGHT INTO SUNDAY LEADING TO
A BIT OF A BACKING. THIS WILL THEN BE FOLLOWED BY A DISSIPATING
BACKDOOR COLD FRONT COMING THROUGH FROM THE NORTH SUNDAY NIGHT.
NORTHERLY FLOW RETURNS BEHIND THIS BOUNDARY AS ANOTHER LARGE HIGH
STARTS TO BUILD IN FROM THE NORTH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR AMZ250-252-
254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...SRP
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
712 PM EDT WED OCT 23 2013
.SYNOPSIS...
COOLER AIR IS ON THE WAY AS ANOTHER COLD FRONT APPROACHES THE REGION
AND PUSHES OFF THE COAST FRIDAY MORNING. BELOW NORMAL TEMPERATURES
ARE EXPECTED THROUGH THE WEEKEND...AND THE FIRST FROST OR FREEZE OF
THE SEASON COULD OCCUR FRIDAY NIGHT INTO EARLY SATURDAY MORNING. A
SLOW WARMING TREND WILL BEGIN SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 715 PM WEDNESDAY...EVERYTHING IS ON-TRACK FOR THE COLDEST
NIGHT OF THE SEASON SO FAR. HIGH PRESSURE CENTERED BACK OVER THE
NORTHERN PLAINS IS PUSHING CHILLY DRY AIR SOUTH ACROSS MOST OF THE
EASTERN HALF OF THE NATION. ANY CHANGES TO THE FORECAST ARE MINOR.
PREVIOUS DISCUSSION FROM 300 PM FOLLOWS...
BEAUTIFUL SUNSHINE AND BREEZY CONDITIONS PREVAIL ACROSS THE AREA
THIS AFTERNOON AS A DRY/COOL AIRMASS HAS SETTLED INTO THE REGION.
THIS DRY AIRMASS WILL CONTINUE THROUGH THE PERIOD AS THE THE LARGE
AMPLITUDE MID-LEVEL TROUGH PROGRESSES OVERHEAD...AND ESSENTIALLY
CUTS OFF OUR MOISTURE SUPPLY FROM BOTH THE GULF OF MEXICO AND
ATLANTIC OCEAN.
FEW/SCT CU FIELD IS PROGRESSING NICELY THROUGH THE AREA AS SEEN FROM
LATEST VISIBLE SATELLITE IMAGERY. THANKS TO LOWER OPACITY OF CLOUD
COVER...PLENTY OF SUNSHINE HAS ALLOWED FOR TEMPS TO ALREADY REACH
INTO THE LOWER 70S. PROJECT FOR TEMPS TO CLIMB JUST A FEW MORE
DEGREES...WITH SOME AREAS REACHING MID 70S...BEFORE THEY BEGIN THEIR
DOWNWARD TREND FOR THE DAY. AS FOR OVERNIGHT LOWS...DECENT
RADIATIONAL COOLING WILL GO INTO EFFECT AS MOSTLY CLEAR SKIES AND
DRY CONDITIONS PREVAIL. ANTICIPATE MOST INLAND AREAS TO DIP INTO THE
MID TO UPPER 30S. ALONG THE COAST...EXPECT LOW 40S JUST ALONG THE
COAST WITH POSSIBLE UPPER 30S JUST ON THE CUSP AS A FAVORABLE SETUP
FOR A DECENT LAND BREEZE WILL ALLOW FOR COLDER TEMPERATURES TO REACH
CLOSER TO THE COAST.
A TIGHTENED PRESSURE GRADIENT AND CAA HAVE ALLOWED FOR SUSTAINED
WEST WINDS AOB 15 KTS WITH GUSTS JUST BELOW 25 KTS SO FAR TODAY.
WINDS WILL VEER BECOMING WNW AS A DETERIORATING WEAK FRONT/PIEDMONT
TROUGH MOVE THROUGH AND THE HIGH PRESSURE SETTLES IN. GUSTS WILL
SUBSIDE...AND SUSTAINED WINDS WILL DROP TO AOB 10 KTS LATER THIS
EVENING. EXPECT FOR WINDS TO BECOME LIGHT OVERNIGHT ACROSS MOST OF
THE AREA...WITH UP TO 8 KTS SUSTAINED ALONG THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...EARLY ON IN THE SHORT TERM PERIOD A
CONFLUENT H5 PATTERN WILL EXIST ACROSS THE NATION/S MID-SECTION WITH
TROFFING ACROSS THE GREAT LAKES INTO NEW ENGLAND. THE VORTICITY IN
THIS SCENARIO IS HIGHLY CHANNELED...NEVERTHELESS THIS SETUP WILL
LEAD TO ANOTHER REINFORCEMENT OF COOLER/DRIER AIR INTO THE CAROLINAS
BY FRIDAY. TIME HEIGHT CROSS SECTIONS INDICATE A DRY COLUMN WILL
PREVAIL...THE EXCEPTION IS A BRIEF PERIOD OF INCREASING LOW-LEVEL
MOISTURE THURSDAY NIGHT INTO FRIDAY MORNING. THIS INCREASE IN
MOISTURE IS LIKELY IN RESPONSE TO BACKING LOW-LEVEL WINDS JUST AHEAD
OF THE NEXT FRONT/SURGE. BY FRIDAY AFTERNOON EXPECT CLEAR
SKIES...AND A DECOUPLED WIND FIELD BY FRIDAY EVENING WHICH WILL SET
THE STAGE FOR OPTIMAL RADIATIONAL COOLING. THE TYPICAL COOL SPOTS
WILL LIKELY DROP TO AT OR BELOW FREEZING DURING THIS TIME
FRAME...WITH MID 30S EXPECTED MOST OTHER LOCATIONS (UPPER 30S TO
AROUND 40 AT THE COAST). THESE ARE THE COOLEST TEMPERATURES THUS FAR
THIS FALL...AND FROST IS ALSO A POSSIBILITY...ESPECIALLY AWAY FROM
THE WARMER COAST. OVERALL DURING FRIDAY NIGHT THE MIN TEMPERATURES
WILL BE WELL BELOW CLIMATOLOGY...WHICH ARE UPPER 40S THIS TIME OF
YEAR.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...LOW LEVEL THERMAL TROUGH/COLD AIR TONGUE
CROSSES THE REGION ON SATURDAY...850MB TEMPS GENERALLY ABOUT 2-3C TO
START THE DAY. WARM AIR ADVECTION THROUGH THE AFTERNOON WARMS THE
LAYER TO 6-7C. AT THE SURFACE HOWEVER HIGH PRESSURE HANGS ON LONG
ENOUGH TO KEEP WINDS LIGHT AND VARIABLE ENOUGH TO KEEP THESE TEMPS
FROM MIXING TO THE SURFACE AND ANOTHER VERY CHILLY DAY EXPECTED. THE
OVERALL HIGHER THETA AIR WILL BE REALIZED AT THE SURFACE SATURDAY
NIGHT THOUGH AS LOWS SHOULD BE CLOSE TO 40...NOT AS CHILLY AS THE
PRIOR TWO BUT STILL A GOOD 10-15 BELOW CLIMO. A LIGHT SOUTH WIND
DEVELOPS ON SUNDAY AND THERE SHOULD BE DEEPER MIXING ALLOWING FOR
HIGHS MUCH CLOSER TO BUT STILL A LITTLE SHY OF NORMAL. A DISSIPATING
BACKDOOR COLD FRONT WILL SLIP THROUGH LATE SUNDAY WITH FAR TOO
LITTLE MOISTURE TO WORK WITH TO CAUSE MUCH MORE THAN JUST A WIND
SHIFT. FOR THE REMAINDER OF THE PERIOD MID LEVEL FLOW WILL BE NEARLY
ZONAL AND QUITE WEAK AS THE LARGE TROUGHINESS OVER EASTERN CANADA
WEAKENS CONSIDERABLY AND SOME INCREASING AMPLITUDE TAKES SHAPE OUT
WEST...KEEPING OUT WEATHER DRY AND SEASONABLE.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THE FORECAST
PERIOD. CLEAR SKIES OVERNIGHT WITH A RADIATIONAL INVERSION. WINDS
MAY NOT GO COMPLETELY CALM AS THERE WILL BE A LOW LEVEL JET MOVING
THROUGH OVERNIGHT THAT WILL KEEP WINDS AT 5-10KTS. THERE WILL ALSO
BE SOME RENEWED COLD AIR ADVECTION THAT MAY MIX THINGS A BIT.
THURSDAY...LIGHT NORTHWEST FLOW WITH SCATTERED SKIES. A SOUTHWEST
RESULTANT IS POSSIBLE ALONG THE COAST AFTER 18Z.
EXTENDED OUTLOOK...VFR WILL PREVAIL THROUGH THE EXTENDED PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 715 PM WEDNESDAY...18Z SYNOPTIC MODELS PLUS LATEST HIGH-RES
MODELS (HRRR AND RUC) INDICATE A SHORT-LIVED SURGE OF NORTHWEST
WINDS SHOULD DEVELOP IN THE 01Z-04Z (9 PM TO MIDNIGHT EDT)
WINDOW...COURTESY OF A DECOUPLING BOUNDARY LAYER ACROSS THE INTERIOR
EASTERN CAROLINAS. AS THIS REGION OF STRONGER WINDS ALOFT (1000-2000
FT AGL) BLOWS OUT ACROSS THE COASTAL WATERS AND ENCOUNTERS A WARMER
BETTER-MIXED LAYER HEATED BY THE OCEAN BELOW...WINDS SHOULD INCREASE
TO 20-25 KNOTS ACROSS THE NC WATERS AND TO A VERY SOLID 20 KNOTS
ACROSS THE SC WATERS. THE HRRR ACTUALLY SHOWS SCA CONDITIONS
DEVELOPING ACROSS THE SC WATERS...BUT I HAVE BLENDED DOWN WITH OTHER
MODELS WHICH MAINTAINS THE CURRENT ADVISORY STRUCTURE. SEAS CLOSELY
MATCH PREVIOUS FORECAST. PREVIOUS DISCUSSION FROM 300 PM FOLLOWS...
SCA CONTINUES TO BE IN EFFECT FOR AMZ-250 (PENDER/NEW HANOVER) AND
AMZ-252 (BRUNSWICK) DUE MOSTLY TO WNW WINDS WITH SUSTAINED SPEEDS OF
20 TO 25 KTS...AS WELL AS SEAS UP TO 6 FT ALONG THE COASTAL/OFFSHORE
WATERS BOUNDARY NEAR CAPE FEAR. FOR THE SC WATERS...SCEC CONTINUES
FOR THE SC WATERS...CONDITIONS HAVE BEEN DOWNGRADED TO A SCEC FOR
AMZ-254 (HORRY) AND AMZ-256 (GEORGETOWN) WITH WNW WINDS 15 TO 20 KTS
AND SEAS 2 TO 5 FT.
INTO TONIGHT...WINDS WILL GRADUALLY SHIFT TO THE WEST-NORTHWEST AS A
DISSIPATING WEAK FRONT/SHORTWAVE PUSHES THROUGH AND HIGH PRESSURE
CONTINUES TO BUILD INTO THE AREA. SEAS WILL GRADUALLY
SUBSIDE...BECOMING OVERALL 2 TO 4 FT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...SURGE OF COOL AIR WILL WANE THURSDAY
MORNING AS A SURFACE RIDGE AXIS BUILDS ACROSS THE COASTAL WATERS.
THE RESULT WILL BE A DECREASE IN THE OFFSHORE FLOW BY THE AFTERNOON.
THE NEXT REINFORCING SHOT OF COOL AIR WILL ARRIVE FRIDAY MORNING
ALLOWING THE WINDS TO VEER AROUND TO A NORTHERLY DIRECTION AND
INCREASE AGAIN IN THE WAKE OF THE FRONT. THE OFFSHORE FLOW WILL
CREATE A FETCH LIMITATION IN THE LOCAL WAVE GROWTH THUS A RANGE OF
SEAS WILL EXIST THROUGH MUCH OF THE SHORT TERM PERIOD.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE BUILDS IN ON SATURDAY
BRINGING A MUCH DECREASING WIND AND POSSIBLY SOME LATE DAY
VARIABILITY IN THE OTHERWISE NORTHERLY FLOW. THE CENTER OF THE HIGH
SHIFTS WESTWARD AS IT WEAKENS SATURDAY NIGHT INTO SUNDAY LEADING TO
A BIT OF A BACKING. THIS WILL THEN BE FOLLOWED BY A DISSIPATING
BACKDOOR COLD FRONT COMING THROUGH FROM THE NORTH SUNDAY NIGHT.
NORTHERLY FLOW RETURNS BEHIND THIS BOUNDARY AS ANOTHER LARGE HIGH
STARTS TO BUILD IN FROM THE NORTH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR
AMZ250-252.
&&
$$
NEAR TERM...SGL/TRA
SHORT TERM...SRP
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
352 PM EDT TUE OCT 22 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT AND MOVE THROUGH
THE AREA ON WEDNESDAY. COOL HIGH PRESSURE WILL THEN BUILD INTO THE
AREA THURSDAY. ANOTHER COLD FRONT WILL MOVE THROUGH THE AREA
FRIDAY WITH HIGH PRESSURE BUILDING BACK IN FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 335 PM TUESDAY...MID CLOUDS CONTINUE TO STREAM INTO THE
REGION WITH SOME PATCHY LIGHT RAIN. PER THE 3KM HRRR AND 4KM NSSL
WRF AND RAP MODELS...THE BEST CHANCE OF PRECIPITATION WILL OCCUR
DURING THE LATE EVENING AND ESPECIALLY BETWEEN 06Z AND 12Z. WITH A
DRY SUB-CLOUD LAYER...IT WILL TAKE AWHILE FOR THE LOWER LEVELS TO
MOISTEN. QPF TOTALS WILL BE VERY LIGHT...AVERAGING ONLY A FEW
HUNDREDTHS OF AN INCH. WITH MAX TEMPS REMAINING IN THE 60S
TODAY...MINIMUM TEMPS WILL BE COOL TONIGHT WITH LOWS IN THE LOWER
TO MIDDLE 50S OVER MOST AREAS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
AS OF 340 PM TUESDAY...WITH THE FRONT APPROACHING DURING THE
MORNING HOURS ON WEDNESDAY...WILL CONTINUE A SLIGHT CHC OF LIGHT
RAINFALL MAINLY NEAR THE COAST. ONCE AGAIN...QPF TOTALS WILL BE
VERY LIGHT. THE FRONT SHOULD MOVE OFFSHORE BY EARLY AFTERNOON WITH
GUSTY W/WNW WINDS...WITH SKIES BECOMING MOSTLY CLEAR BY 18Z TO 20Z
IN THE AFTERNOON.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS OF 3 PM TUE...HIGH PRES WILL BUILD IN FROM THE WEST WED NIGHT
BRINGING A MUCH COOLER AND DRIER AIRMASS. CAA BRINGS LIGHT MIXING
THROUGH MUCH OF THE OVERNIGHT BUT COULD SEE SOME DECOUPLING LATE
SETTING UP BETTER RADIATIONAL COOLING. EXPECT LOWS TO RANGE FROM
THE UPPER 30S INLAND TO AROUND 50 OBX. WINDS BACK TO THE W THU
AHEAD OF MUCH STRONGER COLD FRONT AND DEEPER SHORTWAVE SET TO MOVE
THROUGH ON FRI. HIGHS SHOULD BE IN THE LOWER 60S THU. LOWS THU
NIGHT WILL GENERALLY BE IN THE LOW 40S TO AROUND 50 OBX. A COLD
BLAST OF ARCTIC AIR WILL ARRIVE ON FRI AS STRONG BUT MOSTLY DRY
COLD FRONT PUSHES THROUGH IN THE MORNING. DID ADD SLIGHT CHANCE
POPS AFTER MIDNIGHT THU NIGHT INTO FRI MORNING AS MODELS SHOWING
LIGHT QPF. MODEL SOUNDING SHOWING MOISTURE CONFINED TO BELOW 700MB
WHILE REMAINING VERY DRY IN THE DENDRITIC GROWTH ZONE SO RAINFALL
AMOUNTS WILL BE LIGHT...GENERALLY LESS THAN 0.05". ARCTIC HIGH
PRES BUILDS INTO THE REGION LATE FRI THROUGH THE WEEKEND. HIGH
TEMPS WILL ONLY CLIMB TO AROUND 55-60 FRI AND SAT...WHICH WILL
BE ABOUT 10-15 DEGREES BELOW CLIMO. EXCELLENT RADIATIONAL COOLING
CONDITIONS EXPECTED WITH CLEAR SKIES...CALM WINDS...AND VERY LOW
TD VALUES WILL ALLOW TEMPS TO PLUMMET WELL DOWN INTO THE LOW TO
MID 30S AWAY FROM THE COAST. WILL LIKELY SEE FROST FOR AREAS AWAY
FROM THE COAST WITH THESE TEMPERATURES. A MODIFYING TREND BEGINS
SUN AS HIGH TRANSLATES EASTWARD THOUGH TEMPS LOOK TO REMAIN BELOW
CLIMO INTO EARLY NEXT WEEK AS BELOW AVG HEIGHTS REMAIN ACROSS THE
EASTERN CONUS.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
SHORT TERM /TONIGHT AND WEDNESDAY/...
AS OF 1250 PM TUESDAY...MID LEVEL OVERCAST DOMINATES THE REGION
THIS AFTERNOON BUT CLOUD DECKS SHOULD LOWER LATER THIS EVENING
INTO TONIGHT AS THE SUB-CLOUD LAYER MOISTENS. WILL STAY
CONSERVATIVE FOR NOW AND KEEP CEILINGS AT THE MVFR LEVEL LATE
TONIGHT INTO EARLY WEDNESDAY WITH SPOTTY LIGHT SHOWERS EXPECTED.
SKIES SHOULD CLEAR BY LATE MORNING ON WEDNESDAY AS A STRONG COLD
FRONT SURGES BY THE AREA.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 3 PM TUE...PRED VFR CONDITIONS EXPECTED THROUGH THE PERIOD.
GENERALLY LIGHT WINDS THU ALTHOUGH ANOTHER STRONG BUT MAINLY DRY
COLD FRONT WILL MOVE THROUGH EARLY FRI WITH STRONG CAA BRINGING
GUSTY NORTHWEST WINDS AGAIN FRI AFTERNOON.
&&
.MARINE...
SHORT TERM /TONIGHT AND WEDNESDAY/...
AS OF 350 PM TUESDAY...WINDS SHOULD BE W/SW TONIGHT AND CONTINUE
MAINLY AT 10 KNOTS OR LESS WITH SEAS GENERALLY 2 TO 3 FEET. STRONG
APPROACHING COLD FRONT ON WEDNESDAY WILL LEAD TO SW WINDS
INCREASING TO 15 TO 20 KNOTS DURING THE MORNING...THEN WITH A GOOD
CAA SURGE BEHIND THE COLD FRONT...EXPECT NORTHERLY WINDS OF 15 TO
20 KNOTS WITH FREQUENT GUSTS TO 25 KNOTS. SEAS WILL RESPOND PER
LOCAL NWPS MODEL...BUILDING TO 5 TO 6 FEET...ESPECIALLY OVER THE
CENTRAL WATERS. GIVEN THE GUSTY WINDS AND BUILDING SEAS...HAVE
INITIATED A SMALL CRAFT ADVISORY FOR ALL WATERS BEGINNING AROUND
16Z ON WEDNESDAY AND CONTINUING INTO WEDNESDAY EVENING/NIGHT.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 3 PM TUE...ONGOING SCA TO START THE LONG TERM WITH STRONG
HIGH PRES BUILDS IN FROM THE WEST BRINGING FREQUENT GUSTS TO 25KT
ACROSS ALL WATERS/SOUNDS AND SEAS UP TO 6 FT ACROSS THE OUTER
PORTIONS OF THE WATERS. GRADIENTS QUICKLY RELAX THROUGH THE
OVERNIGHT WITH WINDS/SEAS EXPECTED TO DROP BELOW SCA CRITERIA ALL
WATERS BY 10Z. ANOTHER STRONG COLD FRONT WILL MOVE THROUGH THE
WATERS EARLY FRIDAY WITH SCA CONDITIONS ONCE AGAIN POSSIBLE WITH
STRONG CAA. EXPECT NNW WINDS TO INCREASE TO 15-25KT AND SEAS TO
BUILD TO 3-6FT...HIGHEST NORTH OF OCRACOKE. WEEKEND SHOULD FEATURE
LIGHTER WINDS...AOB 15KT...AS CANADIAN HIGH PRES BUILDS OVER THE
AREA.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON WEDNESDAY TO MIDNIGHT EDT
WEDNESDAY NIGHT FOR AMZ130-135-156-158.
SMALL CRAFT ADVISORY FROM NOON WEDNESDAY TO 6 AM EDT THURSDAY
FOR AMZ150-152-154.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...SK
AVIATION...CTC/SK
MARINE...CTC/SK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1233 PM CDT TUE OCT 22 2013
.UPDATE...
ISSUED AT 1233 PM CDT TUE OCT 22 2013
RADAR RETURNS AND FLURRIES ARE NOW OCCURRING ACROSS THE NORTHERN
RED RIVER VALLEY...AND WILL EXPAND THE FLURRY MENTION EVEN FURTHER
WEST. IN FACT...THE RAP SHOWS POSSIBLE FLURRIES ACROSS MUCH OF THE
REGION THROUGH THE OVERNIGHT HOURS...AND ADJUSTED ACCORDINGLY.
LAKE EFFECT SNOW HAS NEVER MATERIALIZED (WINDS TOO WEAK)...AND
REMOVED THE SCATTERED SNOW SHOWERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT TUE OCT 22 2013
500 MB UPPER LOW OVER EASTERN LAKE SUPERIOR. STILL HAVE NORTHERLY
FLOW OVER THE AREA BUT WITH WEAK HIGH OVER WESTERN MANITOBA SFC
FLOW IS WEAK AND WITH INVERSION AT 850 MB AND SOME TRAPPED
MOISTURE BELOW THAT CLOUDS WILL BE THE GENERAL RULE THROUGH
WEDNESDAY. SOME BREAKS HERE AND THERE THOUGH. SFC FLOW AROUND LAKE
OF THE WOODS HAVE NOT BE CONDUCIVE FOR ANY LAKE EFFECT SNOW
SHOWERS AS WINDS HAVE BEEN CALM OR VARIABLE UNDER 5 KTS. NOT SURE
ANY CHANGE TODAY...BUT DID KEEP LOW POPS FOR SCT SNOW SHOWERS
AROUND THIS AREA TODAY AS SNOW SHOWERS ARE EVIDENT ON SOUTH END OF
LAKE WINNIPEG OFF CANADIAN RADAR. NO ECHOES SHOWING UP ON DRYDEN
ONT RADAR NEAREST TO LAKE OF THE WOODS REGION.
OTHERWISE...OTHER THAN THE CLOUDS...NEXT CLIPPER TYPE SYSTEM
ENTERING CNTRL ALBERTA WILL TRACK RATHER SIMILAR TO THIS PAST ONE
BUT APPEARS PRETTY WEAK. PREV FCST SEEMED A BIT TOO FAR EAST WITH
PRECIP TONIGHT INTO WED SO TRIMMED BACK A BIT AND EVEN THEN MOST
00Z MODELS KEEP ANY REAL -SN WEST OF OUR FCST AREA. 850 MB TEMPS
CHANGE LITTLE...SO EXPECT ABOUT THE SAME TEMPS FOR HIGHS TODAY AND
WED AS ON MONDAY...BUT DUE TO WARMER START WITH CLOUDS MAYBE A
DEGREE OR TWO WARMER THAN ON MONDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM CDT TUE OCT 22 2013
UPPER LOW WILL MOVE EAST AND THEN NORTHEAST THRU QUEBEC AND 500 MB
FLOW WILL FLATTEN OVER THE NRN PLAINS/SRN CANADIAN PRAIRIES. 850
MB WARM ADV WILL SPREAD EAST THRU THE RRV WED NIGHT INTO NW MN
THURSDAY. WILL HAVE SOME FLURRIES MENTIONED WITH THIS AS ALL
MODELS PAINT SOME VERY LOW QPF.
FOR FRIDAY THROUGH MONDAY...LONG WAVE UPPER AIR PATTERN DOES NOT
CHANGE MUCH THIS PERIOD. LONG WAVE UPPER LEVEL RIDGE REMAINS OVER
WESTERN NORTH AMERICA AND AN UPPER LEVEL TROUGH REMAINS OVER
EASTERN NORTH AMERICA. EASTERN LONG WAVE TROUGH DOES WEAKEN A BIT
THROUGH THE PERIOD HOWEVER WESTERN RIDGE MAINTAINS ITS INTENSITY.
THE GFS AND ECMWF WERE IN REASONABLE AGREEMENT AT 84 HOURS WITH THE
GFS SLIGHTLY FASTER. UPPER AIR PATTERN SPLITS BY THE END OF THE
PERIOD WITH THE ECMWF FASTER THAN THE GFS WITH THE NORTHERN FLOW AND
THE GFS FASTER THAN THE ECMWF WITH THE SOUTHERN FLOW. WILL BLEND THE
GFS AND ECMWF.
WILL TRIM BACK LOW POPS IN THE FAR NORTHEAST ZONES FRI...SUN AND
TUE.
LITTLE CHANGE TO TEMPS FROM YESTERDAYS RUN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1233 PM CDT TUE OCT 22 2013
KIND OF A PERSISTENCE FORECAST THIS TIME AROUND. NOT A HIGH
CONFIDENCE FORECAST IN TERMS OF NAILING CEILING HEIGHTS BUT PRETTY
CONFIDENT IN KEEPING SOME SORT OF CEILINGS AROUND. THERE HAS BEEN A
LOT OF BOUNCING AROUND IN CEILING HEIGHTS THIS MORNING AND AM TRYING
NOT TO CHASE TOO MUCH. WILL GO PREDOMINANT MVFR BUT COULD SEE
BOUNCING BETWEEN VFR AND IFR. HAVE SEEN SOME LOWER VSBYS DUE TO
LIGHT SNOW SHOWERS BUT WILL NOT MENTION ANY AT THIS POINT DUE TO LOW
PROBABILITY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...HOPPES/RIDDLE
AVIATION...GODON
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1026 AM CDT TUE OCT 22 2013
.UPDATE...
ISSUED AT 952 AM CDT TUE OCT 22 2013
UPDATE FOR MINOR ADJUSTMENTS TO POPS THIS AFTERNOON AND TONIGHT.
HAVE DELAYED LIGHT RAIN IN THE FAR NORTHWEST UNTIL LATE AFTERNOON.
THE BULK OF THE PRECIPITATION IS EXPECTED AFTER 00Z THIS EVENING.
THE FAR SOUTHWEST SHOULD BE WARM ENOUGH IN THE LOW LEVELS TO
REMAIN MOSTLY RAIN...WHILE A SWATH OF LIGHT SNOW IS EXPECTED
MAINLY EAST OF HIGHWAY 22. ACCUMULATIONS SHOULD BE UNDER AN INCH.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT TUE OCT 22 2013
MAIN CONCERN IN THE SHORT TERM FORECAST PERIOD WILL BE MORE
PRECIPITATION CHANCES LATER THIS AFTERNOON / TONIGHT.
EARLY MORNING RADAR MOSAIC SHOWED LIGHT RETURNS MOVING ACROSS
SOUTH CENTRAL NORTH DAKOTA. THE OVERALL TREND HAS BEEN FOR THE
AREA OF PRECIPITATION TO DIMINISH OVER THE PAST COUPLE HOURS AND
THIS IS IN LINE WITH MOST SHORT TERM MODEL SOLUTIONS.
THE NEXT UPPER WAVE ARRIVES LATER THIS AFTERNOON / TONIGHT.
THE NAM / GFS SUGGEST THE STRONGER FORCING WILL NOT ARRIVE UNTIL
AFTER 18Z AND WILL DELAY POPS ACCORDINGLY. THE PRECIPITATION CHANCES
SHOULD SPREAD FROM NORTHWEST TO SOUTHEAST IN CONCERT WITH THE BEST
FORCING / VERTICAL MOTION...AND THIS TREND IS ALREADY WELL COVERED
IN THE POP GRIDS. THERMAL PROFILES AGAIN SUGGEST EITHER RAIN OR
SNOW WILL BE THE MAIN PRECIPITATION TYPES. SIMILAR TO MONDAY...HAVE
USED 35F AS THE ALL SNOW THRESHOLD TRANSITIONING TO RAIN AT 38F.
SNOW AMOUNTS WILL GENERALLY STAY LESS THAN HALF AN INCH.
LOOKING AT TEMPERATURES...HAVE KEPT HIGHS FOR TODAY WELL BELOW
NORMAL AGAIN. WILL GO WITH MID 30S TO NEAR 40 EAST...TO MID 40S TO
LOW 50S WEST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 309 AM CDT TUE OCT 22 2013
THE PERSISTENT NORTHWEST FLOW ALOFT INDUCED BY AN UPPER RIDGE ACROSS
THE ROCKIES AND A LONGWAVE TROUGH IN SOUTHEAST CANADA AND INTO THE
GREAT LAKES/OHIO VALLEY WILL LIFT NORTHEAST THROUGH THE PERIOD. THIS
WILL SHIFT THE MAIN JET AND PROLONGED PERIOD OF UPPER SHORTWAVES
FURTHER EAST THURSDAY THROUGH SATURDAY. WARM AIR ADVECTION WILL
INCREASE FRIDAY AND SATURDAY...AHEAD OF THE NEXT ALBERTA CLIPPER
WHICH IS SLATED FOR SUNDAY AFTERNOON INTO MONDAY. MUCH COLDER
TEMPERATURES BEHIND THE CLIPPER ARE FORECAST FOR MONDAY AND TUESDAY.
FOR WEDNESDAY...A SHORTWAVE WILL SLIDE SOUTHEAST ACROSS THE TURTLE
MOUNTAINS AND INTO THE JAMES RIVER VALLEY BY AFTERNOON. A CHANCE FOR
MAINLY SNOW SHOWERS IN THE MORNING AND A RAIN/SNOW MIX POSSIBLE IN
THE AFTERNOON IN THE FAR SOUTH AS THE WAVE DEPARTS. COLD H85 AIR IN
THE TURTLE MOUNTAINS AND ACROSS EAST CENTRAL NORTH DAKOTA MAY YIELD
FLURRIES OR A SNOW SHOWER WEDNESDAY AFTERNOON.
FOR THURSDAY THROUGH SATURDAY...NORTHWEST FLOW RELAXES AS THE
STRONGEST HEIGHT GRADIENT SHIFTS EAST. A BRIEF TRANSITION TO WARM
AIR ADVECTION COMMENCES FRIDAY AND MAINTAINS A PRESENCE INTO SUNDAY.
WILL MAINTAIN A DRY FORECAST DURING THIS TIME WITH A MODERATING
TREND FRIDAY AS HIGHS WILL RISE INTO THE 50S MOST AREAS EXCEPT IN
THE TURTLE MOUNTAINS. EXPECT HIGHS IN THE 40S TO LOWER 50S SATURDAY
AND SUNDAY.
FOR SUNDAY AFTERNOON THROUGH MONDAY...A POTENT ALBERTA CLIPPER WILL
MAKE ITS WAY INTO WESTERN/CENTRAL NORTH DAKOTA. H85 TEMPS TAKE A
DIGGER FROM AROUND +8C SUNDAY AFTERNOON TO -10C MONDAY AFTERNOON.
UNCERTAINTY AT THIS TIME REVOLVES AROUND PRECIPITATION TOTALS. BOTH
THE GFS AND ECMWF ADVERTISE MOSTLY POST FRONTAL PRECIPITATION/SNOW.
THE DIFFERENCE IS THAT THE ECMWF IS MORE AGGRESSIVE IN AMOUNTS AND
IS SLOWEST TO MOVE THROUGH...WHILE THE GFS IS QUICKEST AND LESS
ROBUST. AT THIS TIME...JUST LOOKING AT SNOWFALL AMOUNTS THE GFS
WOULD PROBABLY NOT WARRANT WINTER WEATHER HEADLINES BUT THE ECMWF
WOULD. CONSIDERING OVERALL IMPACTS...ENOUGH EVIDENCE IN BOTH MODELS
FOR A WINTER HEADLINE. WILL TAKE A SLOW APPROACH AND BEGIN TO
ADVERTISE THIS SYSTEM IN THE HAZARDOUS WEATHER OUTLOOK. WILL MONITOR
AND ADJUST IN THE COMING DAYS AS THE LONG RANGE MODELS COME INTO
BETTER AGREEMENT. TUESDAY LOOKS DRY BUT REMAINS COLD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 615 AM CDT TUE OCT 22 2013
A WIDE VARIETY OF CONDITIONS EXIST EARLY THIS MORNING ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. EVERYTHING FROM IFR TO VFR IS
BEING REPORTED. IT APPEARS THE IFR CONDITIONS ARE TIED TO A
FRONTAL BOUNDARY LOCATED FROM NORTHWEST NORTH DAKOTA INTO CENTRAL
SOUTH DAKOTA. THE LATEST HRRR SUGGESTS A MAJORITY OF THE IFR
CONDITIONS SHOULD NOT MOVE MUCH THIS MORNING BEFORE A GRADUAL
IMPROVING TREND TAKES HOLD. WILL STAY WITH MVFR OR VFR THIS
MORNING...AND SHOW SOME IMPROVEMENT INTO THE AFTERNOON. ANOTHER
CHANCE OF PRECIPITATION ARRIVES THIS AFTERNOON NEAR KISN...THEN
SPREADS SOUTHEAST TONIGHT. WILL TREND TO MVFR AGAIN AS THE
PRECIPITATION SPREADS ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RP KINNEY
SHORT TERM...CK
LONG TERM...KS
AVIATION...CK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
615 AM CDT TUE OCT 22 2013
.UPDATE...
ISSUED AT 615 AM CDT TUE OCT 22 2013
LATEST FOG/STRATUS SHOWS IFR/MVFR CIGS WITH PATCHY FOG ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. STATIONARY FRONTAL SYSTEM
STRETCHED FROM NEAR MOOSE JAW CANADA...TO TIOGA AND GLEN ULLIN
AND INTO PIERRE SOUTH DAKOTA. VERY WEAK RADAR RETURNS SHOWING UP
NEAR AND ALONG THIS CONVERGENCE ZONE. THE CURRENT FORECAST HAS
THIS HANDLED WELL AND ONLY MINOR UPDATES TO HOURLY SENSIBLE
WEATHER ELEMENTS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT TUE OCT 22 2013
MAIN CONCERN IN THE SHORT TERM FORECAST PERIOD WILL BE MORE
PRECIPITATION CHANCES LATER THIS AFTERNOON / TONIGHT.
EARLY MORNING RADAR MOSAIC SHOWED LIGHT RETURNS MOVING ACROSS
SOUTH CENTRAL NORTH DAKOTA. THE OVERALL TREND HAS BEEN FOR THE
AREA OF PRECIPITATION TO DIMINISH OVER THE PAST COUPLE HOURS AND
THIS IS IN LINE WITH MOST SHORT TERM MODEL SOLUTIONS.
THE NEXT UPPER WAVE ARRIVES LATER THIS AFTERNOON / TONIGHT.
THE NAM / GFS SUGGEST THE STRONGER FORCING WILL NOT ARRIVE UNTIL
AFTER 18Z AND WILL DELAY POPS ACCORDINGLY. THE PRECIPITATION CHANCES
SHOULD SPREAD FROM NORTHWEST TO SOUTHEAST IN CONCERT WITH THE BEST
FORCING / VERTICAL MOTION...AND THIS TREND IS ALREADY WELL COVERED
IN THE POP GRIDS. THERMAL PROFILES AGAIN SUGGEST EITHER RAIN OR
SNOW WILL BE THE MAIN PRECIPITATION TYPES. SIMILAR TO MONDAY...HAVE
USED 35F AS THE ALL SNOW THRESHOLD TRANSITIONING TO RAIN AT 38F.
SNOW AMOUNTS WILL GENERALLY STAY LESS THAN HALF AN INCH.
LOOKING AT TEMPERATURES...HAVE KEPT HIGHS FOR TODAY WELL BELOW
NORMAL AGAIN. WILL GO WITH MID 30S TO NEAR 40 EAST...TO MID 40S TO
LOW 50S WEST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 309 AM CDT TUE OCT 22 2013
THE PERSISTENT NORTHWEST FLOW ALOFT INDUCED BY AN UPPER RIDGE ACROSS
THE ROCKIES AND A LONGWAVE TROUGH IN SOUTHEAST CANADA AND INTO THE
GREAT LAKES/OHIO VALLEY WILL LIFT NORTHEAST THROUGH THE PERIOD. THIS
WILL SHIFT THE MAIN JET AND PROLONGED PERIOD OF UPPER SHORTWAVES
FURTHER EAST THURSDAY THROUGH SATURDAY. WARM AIR ADVECTION WILL
INCREASE FRIDAY AND SATURDAY...AHEAD OF THE NEXT ALBERTA CLIPPER
WHICH IS SLATED FOR SUNDAY AFTERNOON INTO MONDAY. MUCH COLDER
TEMPERATURES BEHIND THE CLIPPER ARE FORECAST FOR MONDAY AND TUESDAY.
FOR WEDNESDAY...A SHORTWAVE WILL SLIDE SOUTHEAST ACROSS THE TURTLE
MOUNTAINS AND INTO THE JAMES RIVER VALLEY BY AFTERNOON. A CHANCE FOR
MAINLY SNOW SHOWERS IN THE MORNING AND A RAIN/SNOW MIX POSSIBLE IN
THE AFTERNOON IN THE FAR SOUTH AS THE WAVE DEPARTS. COLD H85 AIR IN
THE TURTLE MOUNTAINS AND ACROSS EAST CENTRAL NORTH DAKOTA MAY YIELD
FLURRIES OR A SNOW SHOWER WEDNESDAY AFTERNOON.
FOR THURSDAY THROUGH SATURDAY...NORTHWEST FLOW RELAXES AS THE
STRONGEST HEIGHT GRADIENT SHIFTS EAST. A BRIEF TRANSITION TO WARM
AIR ADVECTION COMMENCES FRIDAY AND MAINTAINS A PRESENCE INTO SUNDAY.
WILL MAINTAIN A DRY FORECAST DURING THIS TIME WITH A MODERATING
TREND FRIDAY AS HIGHS WILL RISE INTO THE 50S MOST AREAS EXCEPT IN
THE TURTLE MOUNTAINS. EXPECT HIGHS IN THE 40S TO LOWER 50S SATURDAY
AND SUNDAY.
FOR SUNDAY AFTERNOON THROUGH MONDAY...A POTENT ALBERTA CLIPPER WILL
MAKE ITS WAY INTO WESTERN/CENTRAL NORTH DAKOTA. H85 TEMPS TAKE A
DIGGER FROM AROUND +8C SUNDAY AFTERNOON TO -10C MONDAY AFTERNOON.
UNCERTAINTY AT THIS TIME REVOLVES AROUND PRECIPITATION TOTALS. BOTH
THE GFS AND ECMWF ADVERTISE MOSTLY POST FRONTAL PRECIPITATION/SNOW.
THE DIFFERENCE IS THAT THE ECMWF IS MORE AGGRESSIVE IN AMOUNTS AND
IS SLOWEST TO MOVE THROUGH...WHILE THE GFS IS QUICKEST AND LESS
ROBUST. AT THIS TIME...JUST LOOKING AT SNOWFALL AMOUNTS THE GFS
WOULD PROBABLY NOT WARRANT WINTER WEATHER HEADLINES BUT THE ECMWF
WOULD. CONSIDERING OVERALL IMPACTS...ENOUGH EVIDENCE IN BOTH MODELS
FOR A WINTER HEADLINE. WILL TAKE A SLOW APPROACH AND BEGIN TO
ADVERTISE THIS SYSTEM IN THE HAZARDOUS WEATHER OUTLOOK. WILL MONITOR
AND ADJUST IN THE COMING DAYS AS THE LONG RANGE MODELS COME INTO
BETTER AGREEMENT. TUESDAY LOOKS DRY BUT REMAINS COLD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 615 AM CDT TUE OCT 22 2013
A WIDE VARIETY OF CONDITIONS EXIST EARLY THIS MORNING ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. EVERYTHING FROM IFR TO VFR IS
BEING REPORTED. IT APPEARS THE IFR CONDITIONS ARE TIED TO A
FRONTAL BOUNDARY LOCATED FROM NORTHWEST NORTH DAKOTA INTO CENTRAL
SOUTH DAKOTA. THE LATEST HRRR SUGGESTS A MAJORITY OF THE IFR
CONDITIONS SHOULD NOT MOVE MUCH THIS MORNING BEFORE A GRADUAL
IMPROVING TREND TAKES HOLD. WILL STAY WITH MVFR OR VFR THIS
MORNING...AND SHOW SOME IMPROVEMENT INTO THE AFTERNOON. ANOTHER
CHANCE OF PRECIPITATION ARRIVES THIS AFTERNOON NEAR KISN...THEN
SPREADS SOUTHEAST TONIGHT. WILL TREND TO MVFR AGAIN AS THE
PRECIPITATION SPREADS ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...CK
LONG TERM...KS
AVIATION...CK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1032 PM EDT WED OCT 23 2013
.SYNOPSIS...
COLD AIR WILL CONTINUE TO FILTER INTO THE REGION ON NORTHWEST WINDS.
FLOW OFF THE GREAT LAKES AND A SECONDARY COLD FRONT WILL BRING PERIODS
OF RAIN AND SNOW SHOWERS TONIGHT INTO THURSDAY. HIGH PRESSURE OF
CANADIAN ORIGIN WILL BUILD INTO THE REGION PROVIDING ANOTHER ROUND
OF SUB-FREEZING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
SHOWER ACTIVITY HAS DIMINISHED TO ALL BUT A COUPLE VERY LIGHT
RETURNS IN THE FAR NORTH. REGIONAL RADAR MOSAIC STILL SHOWS
SCATTERED LAKE EFFECT ACTIVITY STREAMING OFF SOUTHEASTERN LAKE
MICHIGAN. LATEST HI-RES MODEL GUIDANCE GENERALLY DOES NOT SUPPORT
THIS ACTIVITY MAKING ITS WAY INTO OHIO...BUT OPTED TO MAINTAIN A
SLIGHT CHANCE OF SHOWERS /RAIN CHANGING TO SNOW/ ACROSS THE FAR
NORTHERN CWA TONIGHT. OTHER MAIN CONCERN TONIGHT IS CLOUD COVER
AND ITS EFFECTS ON LOW TEMPERATURES AND THE FREEZE WARNING.
EARLIER THIS EVENING CLOUDS HAD SCATTERED OUT NICELY ACROSS MUCH
OF THE AREA WHICH ALLOWED TEMPS TO QUICKLY DROP INTO THE MID 30S
IN THE CLEAR SLOTS. CURRENT SATELLITE IMAGERY SHOWS A MID LEVEL
CLOUD DECK STREAMING IN FROM INDIANA AND TEMPS HAVE JUMPED UP A
DEGREE OR TWO WHERE THESE CLOUDS HAVE MOVED IN. THE 00Z NAM AND
01Z RAP SEEM TO HAVE A GOOD HANDLE ON CURRENT CLOUD COVER AND
WOULD SEEM TO SUGGEST PARTLY TO MOSTLY CLOUDY SKIES TONIGHT. WILL
HAVE TO MONITOR TRENDS OVERNIGHT BUT FEEL THAT CURRENT WEAK COLD
ADVECTION REGIME MAY STILL ALLOW TEMPERATURES TO DROP INTO THE
LOWER 30S IN MOST LOCATIONS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
A DEEP MEAN TROF OVER THE EASTERN CONUS WILL CONTINUE TO INFLUENCE
OUR WEATHER. NORTHWEST FLOW WILL CONTINUE...AND ADDITIONAL SHOWERS
WILL BE POSSIBLE THURSDAY OFF THE GREAT LAKES. ALSO...A S/W
PASSING THRU THE MEAN TROF MAY LEAD TO SHOWERS ACRS THE SRN ZONES.
CONSIDERABLE CLOUDINESS CAN BE EXPECTED WITH TEMPERATURES CLOSE TO
20 DEGREES BELOW NORMAL. HIGHS ON THURSDAY ARE EXPECTED TO BE
RANGE FROM THE LOWER 40S NORTH TO THE MID/UPR 40S SOUTH.
THE UPPER LEVEL TROF WILL BEGIN TO SHIFT EAST...AS SFC HIGH
PRESSURE BUILDS EASTWARD TOWARD OUR AREA. THIS HIGH SHOULD ALLOW
SOME CLEARING THURSDAY NIGHT...WHILE WINDS BECOME VERY LIGHT. THIS
WOULD ALLOW TEMPERATURES TO DROP INTO THE UPPER 20S...WITH A HARD
FREEZE LIKELY ACRS ALL COUNTIES.
THE SFC HIGH WILL BUILD SE BECOMING CENTERED OVER TN ON FRIDAY...
PROVIDING MOSTLY SUNNY TO PARTLY CLOUDY SKY CONDITIONS. AFTER A
COLD START TO THE DAY...HIGHS ARE EXPECTED TO ONLY REACH THE UPPER
40S.
THE COLD HIGH WILL CONTINUE TO INFLUENCE OUR WEATHER WITH SKIES
BECOMING MOSTLY CLEAR FRIDAY NIGHT. LOWS ARE EXPECTED TO BE IN THE
UPPER 20S TO LOWER 30S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
FOR SATURDAY...HIGH PRESSURE WILL BE MOVING EAST AS A COLD FRONT
CROSSES THE GREAT LAKES. THIS SCENARIO WILL MEAN INCREASING CLOUDS
AND WINDS BUT PROBABLY NO PRECIPITATION. HIGH PRESSURE AND PARTLY
CLOUDY SKIES WILL RETURN ON SUNDAY. THE HIGH WILL MAINTAIN DRY
WEATHER ON MONDAY EVEN AS ANOTHER COLD FRONT MOVES THROUGH THE
EASTERN GREAT LAKES.
WEATHER WILL CHANGE STARTING TUESDAY. A SLOW MOVING FRONTAL BOUNDARY
WILL FORM TO THE WEST AND THEN PROPAGATE INTO THE ILN AREA. THIS
WILL BRING THE LIKELIHOOD FOR SHOWERS BY TUESDAY NIGHT...WITH THE
CHANCE OF SHOWERS CONTINUING THROUGH WEDNESDAY AS THE FRONT MEANDERS
OVER THE REGION.
THE TREND OF BELOW NORMAL TEMPERATURES WILL PERSIST ON SATURDAY AND
SUNDAY WITH HIGHS FORECAST TO BE IN THE LOW TO MID 50S. READINGS MAY
RISE CLOSE TO NORMAL INTO THE LOW 60S BY TUESDAY AS WARM ADVECTION
OCCURS NEAR THE FRONT.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
SHOWER ACTIVITY CONTINUES TO DIMINISH ACROSS THE AREA. EXPECT MAINLY
DRY CONDITIONS FOR THE REST OF TONIGHT AS HIGH PRESSURE NOSES IN
FROM THE SOUTH. MID LEVEL CLOUDS HAVE SCATTERED OUT ACROSS MUCH
OF THE AREA BUT SATELLITE SHOWS PLENTY OF LOW/MID LEVEL CLOUDS
JUST OFF TO THE WEST ACROSS INDIANA/ILLINOIS THAT WILL EVENTUALLY
WORK THEIR WAY INTO OUR AREA OVERNIGHT. AS A DISTURBANCE ROUNDS
THE BASE OF AN UPPER LEVEL TROUGH THURSDAY MORNING...A WEAK COLD
FRONT WILL SLIDE THROUGH THE TAF SITES. THESE FEATURES ARE
EXPECTED TO BRING AN MVFR CLOUD DECK INTO THE AREA BY LATE MORNING
AND POSSIBLY A FEW LIGHT RAIN/SNOW SHOWERS. BEST CHANCE FOR ANY
PRECIP LOOKS TO BE ACROSS THE SOUTH SO INCLUDED MENTION OF VCSH
FOR SOUTHERN TERMINALS. CIGS EXPECTED TO RETURN TO VFR BY MID TO
LATE AFTERNOON. WINDS WILL BE LIGHT OUT OF THE WEST TONIGHT...
SHIFTING TO THE SW THURSDAY MORNING AND PICKING UP TO 10-15 KNOTS
OUT OF THE NW BY AFTERNOON ONCE THE FRONT MOVES THROUGH. VSBYS
WILL REMAIN VFR THROUGH THE TAF PERIOD.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FREEZE WARNING FROM 2 AM TO 10 AM EDT THURSDAY FOR OHZ026-034-
035-042>046-051>056-060>065-070>074-077>082-088.
KY...FREEZE WARNING FROM 2 AM TO 10 AM EDT THURSDAY FOR KYZ089>100.
IN...FREEZE WARNING FROM 2 AM TO 10 AM EDT THURSDAY FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...AR
NEAR TERM...KURZ
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...KURZ
AREA FORECAST DISCUSSION
NWS PORTLAND OR
226 PM PDT TUE OCT 22 2013
.SYNOPSIS...STRONG BLOCKING HIGH PRESSURE RIDGE ALOFT WILL CONTINUE
TO BE THE DOMINANT FEATURE FOR THE NEXT FEW DAYS...WHICH WILL
MAINTAIN STRONG VALLEY INVERSIONS. AN UPPER LOW TRAPPED WITHIN THE
RIDGE DRIFTS TO VANCOUVER ISLAND BY THU AFTERNOON AND THEN REMAINS
NEARLY STATIONARY UNTIL SAT. OFFSHORE LOW-LEVEL FLOW WEAKENS TONIGHT
AND WED. LONGER RANGE MODELS ARE HINTING AT A CHANGE TO A COOLER
REGIME LATE IN THE WEEKEND AND EARLY NEXT WEEK.
&&
.SHORT TERM...TONIGHT THROUGH FRIDAY...
THE LARGE-SCALE PATTERN REMAINS UNCHANGED...WITH A STRONG UPPER LEVEL
RIDGE CENTERED ALONG THE BRITISH COLUMBIA COAST THROUGH ABOUT KAST
AND ALONG THE CASCADES. WATER VAPOR IMAGERY SHOWS A TRAPPED UPPER LOW
AT 43N 130W. THE LARGE-SCALE FEATURES WILL SHOW VERY LITTLE CHANGE
THROUGH THU. THE MAIN CHANGE WILL BE THE TRAPPED LOW. MODELS SHOW IT
DRIFTING TO VANCOUVER ISLAND BY 18Z THU.
THE BIGGER CHANGES WILL OCCUR ON THE SMALLER SCALE. STRATUS SURGE HAS
WORKED ITS WAY TO THE S WA COAST AS OF 20Z...BUT NOT ENOUGH INLAND
PENETRATION TO REACH KTMK. KAST WEBCAMS SHOWING SOME LOW STRATUS JUST
TO THE WEST JUST BEFORE 20Z. 12Z NAM12 MODEL DOES NOT SEEM TO HAVE A
GOOD FEEL FOR THIS LOW-LEVEL MOISTURE...AT LEAST LOOKING AT THE 975MB
LEVEL. OBVIOUSLY THIS MOISTURE IS BELOW 975MB.THE 17Z HRRR 2M RH
FIELD SEEMS TO HAVE A PRETTY DECENT HANDLE ON THE STRATUS. IT SHOWS
THE LOW CLOUDS ALONG THE BEACHES PUNCHING INTO THE MAJOR COASTAL
RIVER DRAINAGES AROUND SUNSET.
THE OTHER SMALL-SCALE FEATURE OF NOTE IS THE OFFSHORE FLOW. THE
KTTD-KDLS GRADIENT WAS AROUND -5.5 MB LATE THIS MORNING. 20Z
SEA-LEVEL PRESSURE READING AT KDLS NOT AVAILABLE DUE TO MAINTENANCE
ON THE SENSOR(S). THE 20Z KPDX-KTTD GRADIENT WAS 1.0 MB...WHICH IS
TYPICALLY TOO HIGH FOR EAST WIND TO SURFACE AT KPDX. CROWN POINT WIND
SENSOR STILL GUSTING TO 45 MPH. NAM MAINTAINS THIS OFFSHORE FLOW
TONIGHT...THEN WEAKENS IT WED. THE COMBINATION OF INVERSIONS AND THE
LOW-LEVEL OFFSHORE FLOW WILL MAKE INLAND TEMPERATURE FORECASTING
SOMEWHAT TRICKY. CASCADES AND HIGHER ELEVATIONS OF THE COAST RANGE
WILL REMAIN BALMY...EVEN AT NIGHT. TEMPERATURES IN VALLEYS...LOWEST
CASCADE FOOTHILLS...AND AREAS AT THE WEST END OF THE GORGE WILL BE
MOST TRICKY.
EXPECT THE STRATUS TO PERSIST ALONG THE COAST AT LEAST WED AND THU.
LEFT IN THE MENTION OF THE POSSIBILITY OF DRIZZLE LATE TONIGHT...
ALTHOUGH IT SEEMS THE BETTER CHANCE MIGHT BE WED NIGHT IF THE MARINE
LAYER CONTINUES TO DEEPEN. A MUDDLED SYNOPTIC PATTERN DEVELOPS THU
NIGHT AND FRI. THE STRAY CUT-OFF LOW CONTINUES TO HANG OUT AROUND
VANCOUVER ISLAND...WHILE A MUCH STRONGER LOW REACHES 37N 132W...WITH
STRONG HIGH PRESSURE ALOFT OVER THE PAC NW. FLAT SURFACE GRADIENTS
THU NIGHT AND FRI WILL HELP TO STRENGTHEN THE INVERSIONS AND ALLOW
VALLEY FOG AND STRATUS COVERAGE TO INCREASE. WEISHAAR
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...EXPECT DRY AND MILD
CONDITIONS TO PREVAIL THROUGH THE WEEKEND AS HIGH PRESSURE REMAINS
IN CONTROL. NIGHT TIME FOG FORMATION WILL BE THE PRIMARY ISSUE FOR
THE AREA THROUGH THE EXTENDED PERIOD. LATE SUNDAY THE UPPER FLOW
BECOMES AMPLIFIED AND MERIDIONAL AS A SHORTWAVE DIGS SOUTH TOWARD
THE GREAT BASIN FROM ALBERTA. AT THIS TIME IT DOES NOT APPEAR THAT
ANY MOISTURE WILL MAKE IT INTO OUR AREA FROM THIS LOW...HOWEVER THE
POTENTIAL IS THERE FOR AN IMPACT ON TEMPERATURES. HOW MUCH OF AN
IMPACT WILL DEPEND ON HOW CLOSE THIS WAVE GETS TO THE COLUMBIA RIVER
GORGE. IF IT PROGRESSES CLOSER THAN CURRENT MODELS DEPICT...THEN
EASTERLY WINDS THROUGH THE GORGE WILL BE STRONGER AND TEMPERATURES
COOLER THAN CURRENTLY FORECAST. HIGH PRESSURE ALOFT RETURNS TUESDAY.
BURGESS
&&
.AVIATION...MOSTLY VFR CONDITIONS PREVAIL THROUGH ABOUT 00Z THIS
EVENING. THE CENTRAL OREGON COAST WILL REMAIN UNDER IFR/LIFR LOW
MARINE CLOUDS...BUT MAY BRIEFLY LIFT TO MVFR FROM 21Z-00Z.
OTHERWISE...OFFSHORE FLOW WEAKENS TONIGHT WHICH WILL ALLOW MORE
EXTENSIVE LIFR LOW CLOUDS/FOG TO DEVELOP ALONG THE COAST AND
INLAND AFTER 06Z.
KPDX AND APPROACHES...VFR THROUGH 06Z. MARINE STRATUS WILL PUSH
ALONG THE COLUMBIA RIVER TONIGHT AS OFFSHORE FLOW WEAKENS...
BRINGING IFR/LIFR STRATUS/FOG AFTER 08Z. /27
&&
.MARINE...LITTLE CHANGE FOR THE MARINE ENVIRONMENT FOR THIS WEEK.
RATHER TRANQUIL WEATHER PREVAILS...WITH WINDS 15 KT OR LESS. SEAS
RUNNING 6 TO 7 FT THROUGH THIS EVENING...BUT WILL SUBSIDE BACK TO
3 TO 5 FT ON WED...AND HOLD AT THAT RANGE THROUGH FRI. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
914 PM MDT WED OCT 23 2013
.UPDATE...
ISSUED AT 911 PM MDT WED OCT 23 2013
LATEST SATELLITE LOOP SUGGEST MORE CLOUDS WILL HANG AROUND
OVERNIGHT THAN PREVIOUS THOUGHT...WHICH IS IN LINE WITH 00Z KUNR
SOUNDING AND LATEST RAP GUIDANCE. UPDATE SHORTLY.
&&
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 210 PM MDT WED OCT 23 2013
UPPER LEVEL ANALYSIS HAS VERY AMPLIFIED FLOW WITH LARGE RIDGE OVER
THE WESTERN CONUS AND LARGE TROF OVER THE EASTERN CONUS. FAST
NORTHWEST FLOW CONTINUES IN BETWEEN THESE TWO FEATURES OVER THE
NORTHERN PLAINS...WITH MOSTLY CLOUDY SKIES PREVAILING.
TEMPERATURES ARE IN THE 40S AND LOWER 50S WITH BREEZY NORTH WINDS
ACROSS THE SOUTH DAKOTA PLAINS.
TONIGHT...WESTERN UPPER LEVEL RIDGE SLOWLY SHIFTS EAST INTO THE
GREAT BASIN AREA WHILE CANADIAN HIGH PRESSURE NOSES INTO THE
NORTHERN PLAINS. CLOUD COVER SHOULD BE ON THE DECREASE TONIGHT
WITH SKIES CLEARING AFTER MIDNIGHT. WITH LIGHT WINDS
EXPECTED...LOW TEMPERATURES SHOULD FALL INTO THE 20S ACROSS THE
AREA.
THURSDAY...UPPER RIDGE NUDGES A LITTLE FURTHER EAST AS SURFACE
HIGH SETTLES OVER THE NORTHERN PLAINS. MOSTLY SUNNY SKIES ARE
EXPECTED WITH TEMPERATURES REMAINING COOL. HIGHS WILL REMAIN IN
THE 40S TO LOWER 50S.
THURSDAY NIGHT...UPPER RIDGE EXPANDS ACROSS THE ROCKIES AS SURFACE
HIGH PRESSURE SLIDES INTO THE UPPER MIDWEST. LIGHT WINDS BECOME
SOUTHERLY AS RETURN FLOW PICKS UP ON THE BACKSIDE OF THE HIGH.
SKIES WILL REMAIN CLEAR WITH LOW TEMPERATURES SLIGHTLY MILDER
OVERNIGHT...IN THE MID 20S TO MID 30S.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 210 PM MDT WED OCT 23 2013
UPPER RIDGE OVER THE WESTERN CONUS WILL BRING DRY WEATHER AND
SLIGHTLY WARMER THAN AVERAGE TEMPERATURES FROM FRIDAY THROUGH THE
WEEKEND. ALTHOUGH THE MEDIUM RANGE MODELS DIFFER IN THE DETAILS AT
THIS POINT...MOST AGREE IN SHOWING AN UPPER TROUGH AFFECTING THE
FORECAST AREA EARLY NEXT WEEK...BRINGING MUCH COLDER TEMPERATURES
AND A GOOD CHANCE FOR SNOW EARLY NEXT WEEK. THERE IS POTENTIAL FOR
SOME AREAS TO RECEIVE AT LEAST SEVERAL INCHES OF
SNOWFALL...ESPECIALLY ACROSS NORTHEASTERN WY INTO PORTIONS OF
WESTERN SD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 911 PM MDT WED OCT 23 2013
AREAS MVFR CIGS WILL CONTINUE FROM THE BLACK HILLS AREA...NORTH
AND EASTWARD ACROSS THE PLAINS THROUGH EARLY THURSDAY. AREAS IFR
CONDITIONS ARE ALSO POSSIBLE IN THESE AREAS OVERNIGHT INTO EARLY
THURSDAY. VFR CONDITIONS ARE GENERALLY EXPECTED TO THE SOUTHWEST
OF THE BLACK HILLS...AND THEN OVER THE REST OF THE AREA AS CLOUDS
THIN/LIFT AS THE DAY PROGRESSES THURSDAY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...HELGESON
SHORT TERM...15
LONG TERM...26
AVIATION...HELGESON
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
119 PM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 422 AM CDT TUE OCT 22 2013
CLIPPER SYSTEM MOVING ACROSS THE AREA THIS MORNING. LOOKS LIKE
ENOUGH UPPER LEVEL ENERGY HANGS AROUND TO KEEP THE PRECIPITATION
GOING A BIT LONGER THIS MORNING THAN PREVIOUSLY FORECAST. NAM...HRRR
AND RAP ALL SUGGEST LIGHT PRECIPITATION WILL LINGER THROUGH 15Z IN
SIOUX FALLS AND 17Z OR SO ACROSS PORTIONS OF NORTHWEST IOWA. WOULD
EXPECT THIS TO BE PREDOMINATELY LIGHT SNOW ALONG AND NORTHEAST OF A
HURON TO SIOUX FALLS TO SPENCER IOWA LINE...WITH A FEW SNOWFLAKES
EVEN POTENTIALLY MIXING IN AS FAR SOUTH AS AREAS JUST NORTH OF THE
MISSOURI RIVER. THE AFTERNOON HOURS WILL BE DRY...WITH SKIES
BECOMING PARTLY SUNNY. EXPECTING GOOD MIXING AGAIN...AND BASED ON
HOW WARM WE WERE ABLE TO GET YESTERDAY...WENT AHEAD AND BUMPED HIGHS
UP A FEW DEGREES FOR TODAY...MAINLY LOW AND MID 40S.
ANOTHER CLIPPER SYSTEM WILL DROP SOUTHEAST TOWARDS THE AREA LATER
TONIGHT INTO WEDNESDAY. TEMPERATURES TONIGHT ARE TRICKY. WITH CALM
WINDS LOCATIONS IN THE EAST SHOULD DROP RAPIDLY IN THE EVENING
HOURS. MEANWHILE AS CLOUDS INCREASE FROM WEST TO EAST TEMPERATURES
WILL BEGIN TO RISE. TRIED TO SHOW THIS IN THE GRIDS...BUT WOULD NOT
BE SURPRISED IF LOCATIONS EATS OF INTERSTATE 29 END UP A BIT COLDER
THAN CURRENTLY FORECAST. THE CLIPPER SYSTEM ITSELF SEEMS TO BE
TRENDING SOUTHWEST. FOLLOWING A CONSENSUS OF THE NAM...GFS...ECMWF
AND HI RES MODELS SEEMS LIKE A GOOD CALL AT THIS POINT. OVERALL WOULD
THINK THE OVERALL EVOLUTION WILL BE SIMILAR TO WHAT HAPPENED WITH THE
CURRENT SYSTEM...A BROAD AREA OF LIGHT PRECIP AND A EMBEDDED BAND OF
HIGHER QPF ASSOCIATED WITH MID LEVEL FRONTOGENESIS. 500 TO 300 MB Q
VECTOR CONVERGENCE A BIT STRONGER WITH THE SYSTEM TONIGHT...LIKELY
OWING TO A STRONGER UPPER JET. SO WOULD NOT BE SURPRISED IF QPF
AMOUNTS END UP A BIT HIGHER OVERALL. PRECIPITATION TYPE IS AGAIN AN
ISSUE. LOOKS PRETTY SIMILAR TO THIS MORNINGS EVENT IN THAT AN AREA
OF SNOW WILL BE LIKELY ON THE NORTHERN EDGE OF THE BAND. BOUNDARY
LAYER IS A BIT WARMER...SUGGESTING THE AREA THAT SEES MAINLY SNOW
WILL PROBABLY BE PRETTY SMALL. AGAIN ONLY THINKING WE SEE A COATING
TO AN INCH OF ACCUMULATION. WOULD THINK ANYWHERE ALONG AND NORTHEAST
OF A HURON TO SIOUX FALLS TO SIOUX CITY LINE WOULD SEE THE BEST
CHANCE OF THIS LIGHT ACCUMULATION. WILL CONTINUE TO MONITOR
TRENDS...AS IF THINGS WORKS OUT JUST RIGHT...COULD SEE A NARROW AREA
OF 1 TO 2 INCHES OF SNOW...BUT GIVEN THE MARGINAL THERMAL PROFILE
AND QPF PLACEMENT UNCERTAINTY...CONFIDENCE REMAINS LOW. STILL SOME
TIMING DIFFERENCES AS WELL...BUT GENERALLY LOOKS LIKE THE PRECIP
WILL ENTER OUR WEST AROUND 08Z AND APPROACH INTERSTATE 29 AROUND
11Z. PRECIP WILL EXIT BY LATE MORNING OR EARLY AFTERNOON. SKIES WILL
REMAIN MOSTLY CLOUDY THROUGH THE AFTERNOON...WITH ANOTHER DAY OF
HIGHS ONLY IN THE 40S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 422 AM CDT TUE OCT 22 2013
LESS ACTIVE PATTERN RETURNS TO THE AREA WEDNESDAY NIGHT AS WAVE EXITS
TO THE SOUTHEAST. STILL IN COOL NORTHWEST FLOW INTO THURSDAY...SO
WELL BELOW NORMAL TEMPERATURES WILL STICK AROUND FOR ONE MORE DAY.
ANTICIPATE FAIR AMOUNT OF HEATING-DRIVEN CUMULUS IN OUR NORTHEAST
THURSDAY AFTERNOON BASED ON FORECAST SOUNDINGS...WITH SOME MODELS
SQUEEZING OUT A FEW SPRINKLES. HAVE NOT INCLUDED ANY PRECIP MENTION
AT THIS TIME...BUT EVEN IF THEY DO OCCUR...SHOULD BE SPOTTY AND VERY
LIGHT. NORTHWEST WINDS BECOMING GUSTY WITH THE GOOD MIXING AS WELL...
WITH BOTH CLOUDS AND WIND DIMINISHING IN THE EVENING AS SURFACE RIDGE
PUSHES INTO THE CWA FROM THE WEST. TEMPERATURES WEDNESDAY NIGHT AND
THURSDAY NIGHT LIKELY TO BE IN THE MID-UPPER 20S MOST AREAS...WITH
HIGHS THURSDAY AGAIN IN THE 40S.
LONGER RANGE FRIDAY THROUGH MONDAY FEATURES WESTERN CONUS RIDGE
NUDGING EASTWARD THROUGH THE WEEKEND. STRONG WARMING ALOFT ON FRIDAY
NOT LIKELY TO BE FULLY REALIZED AT THE SURFACE...THOUGH MOST AREAS
SHOULD AT LEAST WARM BACK INTO THE 50S...WITH SOME LOWER 60S NOT OUT
OF THE QUESTION IN OUR SOUTHWEST. UPPER WAVE DROPPING FROM CENTRAL
CANADA INTO THE WESTERN GREAT LAKES FRIDAY NIGHT/SATURDAY WILL DRAG A
COOL FRONT SOUTHEAST THROUGH THE NORTHERN PLAINS. MODELS NOW TRENDING
BACK TOWARD HOLDING THE COLDEST OF AIR WITH THIS SYSTEM NORTHEAST OF
OUR AREA...THOUGH WILL LIKELY STILL SEE HIGHS SATURDAY KNOCKED BACK A
FEW DEGREES FROM FRIDAYS READINGS...UPPER 40S IN SOUTHWEST MINNESOTA
TO MID 50S IN OUR SOUTHWEST. ANOTHER PUSH OF WARMER AIR ALOFT SHOULD
HELP HIGHS SUNDAY CLIMB BACK INTO THE 50S TO MAYBE LOWER 60S. THIS
AHEAD OF STRONGER WAVE SLATED TO AFFECT THE REGION EARLY NEXT WEEK.
MODELS DIFFERING ON TIMING SLIGHTLY...WITH GFS FASTER/COOLER THAN
ECMWF BY LATE MONDAY...THOUGH BOTH MODELS CURRENTLY HOLD OFF BETTER
PRECIP CHANCE FOR MOST OF OUR AREA UNTIL MONDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 116 PM CDT TUE OCT 22 2013
CEILINGS WILL CONTINUE TO IMPROVE THROUGH THE AFTERNOON HOURS
SETTLING IN ON THE LOW END SIDE OF VFR. CONDITIONS ARE EXPECTED TO
BECOME PARTLY CLOUDY THIS EVENING...WITH CEILINGS LOWERING INTO
THE MVFR RANGE OVERNIGHT AS ANOTHER FAST MOVING WAVE MOVES THROUGH
THE AREA. APPEARS AS THOUGH THERE IS A LIMITED AMOUNT OF ICE
PRODUCTION IN THE CLOUDS...WHICH SHOULD LIMIT SNOW FALL AMOUNTS
AND REDUCTIONS TO VISIBILITY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...JH
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
618 AM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 422 AM CDT TUE OCT 22 2013
CLIPPER SYSTEM MOVING ACROSS THE AREA THIS MORNING. LOOKS LIKE
ENOUGH UPPER LEVEL ENERGY HANGS AROUND TO KEEP THE PRECIPITATION
GOING A BIT LONGER THIS MORNING THAN PREVIOUSLY FORECAST. NAM...HRRR
AND RAP ALL SUGGEST LIGHT PRECIPITATION WILL LINGER THROUGH 15Z IN
SIOUX FALLS AND 17Z OR SO ACROSS PORTIONS OF NORTHWEST IOWA. WOULD
EXPECT THIS TO BE PREDOMINATELY LIGHT SNOW ALONG AND NORTHEAST OF A
HURON TO SIOUX FALLS TO SPENCER IOWA LINE...WITH A FEW SNOWFLAKES
EVEN POTENTIALLY MIXING IN AS FAR SOUTH AS AREAS JUST NORTH OF THE
MISSOURI RIVER. THE AFTERNOON HOURS WILL BE DRY...WITH SKIES
BECOMING PARTLY SUNNY. EXPECTING GOOD MIXING AGAIN...AND BASED ON
HOW WARM WE WERE ABLE TO GET YESTERDAY...WENT AHEAD AND BUMPED HIGHS
UP A FEW DEGREES FOR TODAY...MAINLY LOW AND MID 40S.
ANOTHER CLIPPER SYSTEM WILL DROP SOUTHEAST TOWARDS THE AREA LATER
TONIGHT INTO WEDNESDAY. TEMPERATURES TONIGHT ARE TRICKY. WITH CALM
WINDS LOCATIONS IN THE EAST SHOULD DROP RAPIDLY IN THE EVENING
HOURS. MEANWHILE AS CLOUDS INCREASE FROM WEST TO EAST TEMPERATURES
WILL BEGIN TO RISE. TRIED TO SHOW THIS IN THE GRIDS...BUT WOULD NOT
BE SURPRISED IF LOCATIONS EATS OF INTERSTATE 29 END UP A BIT COLDER
THAN CURRENTLY FORECAST. THE CLIPPER SYSTEM ITSELF SEEMS TO BE
TRENDING SOUTHWEST. FOLLOWING A CONSENSUS OF THE NAM...GFS...ECMWF
AND HI RES MODELS SEEMS LIKE A GOOD CALL AT THIS POINT. OVERALL WOULD
THINK THE OVERALL EVOLUTION WILL BE SIMILAR TO WHAT HAPPENED WITH THE
CURRENT SYSTEM...A BROAD AREA OF LIGHT PRECIP AND A EMBEDDED BAND OF
HIGHER QPF ASSOCIATED WITH MID LEVEL FRONTOGENESIS. 500 TO 300 MB Q
VECTOR CONVERGENCE A BIT STRONGER WITH THE SYSTEM TONIGHT...LIKELY
OWING TO A STRONGER UPPER JET. SO WOULD NOT BE SURPRISED IF QPF
AMOUNTS END UP A BIT HIGHER OVERALL. PRECIPITATION TYPE IS AGAIN AN
ISSUE. LOOKS PRETTY SIMILAR TO THIS MORNINGS EVENT IN THAT AN AREA
OF SNOW WILL BE LIKELY ON THE NORTHERN EDGE OF THE BAND. BOUNDARY
LAYER IS A BIT WARMER...SUGGESTING THE AREA THAT SEES MAINLY SNOW
WILL PROBABLY BE PRETTY SMALL. AGAIN ONLY THINKING WE SEE A COATING
TO AN INCH OF ACCUMULATION. WOULD THINK ANYWHERE ALONG AND NORTHEAST
OF A HURON TO SIOUX FALLS TO SIOUX CITY LINE WOULD SEE THE BEST
CHANCE OF THIS LIGHT ACCUMULATION. WILL CONTINUE TO MONITOR
TRENDS...AS IF THINGS WORKS OUT JUST RIGHT...COULD SEE A NARROW AREA
OF 1 TO 2 INCHES OF SNOW...BUT GIVEN THE MARGINAL THERMAL PROFILE
AND QPF PLACEMENT UNCERTAINTY...CONFIDENCE REMAINS LOW. STILL SOME
TIMING DIFFERENCES AS WELL...BUT GENERALLY LOOKS LIKE THE PRECIP
WILL ENTER OUR WEST AROUND 08Z AND APPROACH INTERSTATE 29 AROUND
11Z. PRECIP WILL EXIT BY LATE MORNING OR EARLY AFTERNOON. SKIES WILL
REMAIN MOSTLY CLOUDY THROUGH THE AFTERNOON...WITH ANOTHER DAY OF
HIGHS ONLY IN THE 40S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 422 AM CDT TUE OCT 22 2013
LESS ACTIVE PATTERN RETURNS TO THE AREA WEDNESDAY NIGHT AS WAVE EXITS
TO THE SOUTHEAST. STILL IN COOL NORTHWEST FLOW INTO THURSDAY...SO
WELL BELOW NORMAL TEMPERATURES WILL STICK AROUND FOR ONE MORE DAY.
ANTICIPATE FAIR AMOUNT OF HEATING-DRIVEN CUMULUS IN OUR NORTHEAST
THURSDAY AFTERNOON BASED ON FORECAST SOUNDINGS...WITH SOME MODELS
SQUEEZING OUT A FEW SPRINKLES. HAVE NOT INCLUDED ANY PRECIP MENTION
AT THIS TIME...BUT EVEN IF THEY DO OCCUR...SHOULD BE SPOTTY AND VERY
LIGHT. NORTHWEST WINDS BECOMING GUSTY WITH THE GOOD MIXING AS WELL...
WITH BOTH CLOUDS AND WIND DIMINISHING IN THE EVENING AS SURFACE RIDGE
PUSHES INTO THE CWA FROM THE WEST. TEMPERATURES WEDNESDAY NIGHT AND
THURSDAY NIGHT LIKELY TO BE IN THE MID-UPPER 20S MOST AREAS...WITH
HIGHS THURSDAY AGAIN IN THE 40S.
LONGER RANGE FRIDAY THROUGH MONDAY FEATURES WESTERN CONUS RIDGE
NUDGING EASTWARD THROUGH THE WEEKEND. STRONG WARMING ALOFT ON FRIDAY
NOT LIKELY TO BE FULLY REALIZED AT THE SURFACE...THOUGH MOST AREAS
SHOULD AT LEAST WARM BACK INTO THE 50S...WITH SOME LOWER 60S NOT OUT
OF THE QUESTION IN OUR SOUTHWEST. UPPER WAVE DROPPING FROM CENTRAL
CANADA INTO THE WESTERN GREAT LAKES FRIDAY NIGHT/SATURDAY WILL DRAG A
COOL FRONT SOUTHEAST THROUGH THE NORTHERN PLAINS. MODELS NOW TRENDING
BACK TOWARD HOLDING THE COLDEST OF AIR WITH THIS SYSTEM NORTHEAST OF
OUR AREA...THOUGH WILL LIKELY STILL SEE HIGHS SATURDAY KNOCKED BACK A
FEW DEGREES FROM FRIDAYS READINGS...UPPER 40S IN SOUTHWEST MINNESOTA
TO MID 50S IN OUR SOUTHWEST. ANOTHER PUSH OF WARMER AIR ALOFT SHOULD
HELP HIGHS SUNDAY CLIMB BACK INTO THE 50S TO MAYBE LOWER 60S. THIS
AHEAD OF STRONGER WAVE SLATED TO AFFECT THE REGION EARLY NEXT WEEK.
MODELS DIFFERING ON TIMING SLIGHTLY...WITH GFS FASTER/COOLER THAN
ECMWF BY LATE MONDAY...THOUGH BOTH MODELS CURRENTLY HOLD OFF BETTER
PRECIP CHANCE FOR MOST OF OUR AREA UNTIL MONDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 612 AM CDT TUE OCT 22 2013
AREA OF LIGHT RAIN AND SNOW WILL DISSIPATE AND EXIT THE AREA BY LATE
MORNING. CIGS IN THE LIFR TO MVFR RANGE WILL SLOWLY LIFT THROUGH THE
MORNING...AND SHOULD BECOME VFR BY MID TO LATE AFTERNOON. BRIEF
VISIBILITY REDUCTIONS INTO THE 2SM TO 4SM RANGE WILL BE POSSIBLE IN
SNOW THROUGH MID MORNING AS WELL. VFR CONDITIONS SHOULD PREVAIL MOST
OF TONIGHT. HOWEVER...ANOTHER LOW PRESSURE SYSTEM WILL BRING A RETURN
TO THE LIGHT RAIN OR SNOW THREAT LATE TONIGHT INTO WEDNESDAY MORNING.
AGAIN WOULD EXPECT CIGS TO DROP WITH THIS FEATURE. FOR NOW KEPT THE
TAFS MVFR AT KHON AND VFR AT KFSD AND KSUX GIVEN UNCERTAINTY OF
TIMING AND PLACEMENT OF PRECIPITATION SHIELD. ALTHOUGH WOULD EXPECT
CIGS TO LOWER INTO THE MVFR TO IFR RANGE AT SOME POINT LATE TONIGHT OR
EARLY WEDNESDAY WHERE THE AREA OF PRECIPITATION MOVES ACROSS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...JH
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
422 AM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 422 AM CDT TUE OCT 22 2013
CLIPPER SYSTEM MOVING ACROSS THE AREA THIS MORNING. LOOKS LIKE
ENOUGH UPPER LEVEL ENERGY HANGS AROUND TO KEEP THE PRECIPITATION
GOING A BIT LONGER THIS MORNING THAN PREVIOUSLY FORECAST. NAM...HRRR
AND RAP ALL SUGGEST LIGHT PRECIPITATION WILL LINGER THROUGH 15Z IN
SIOUX FALLS AND 17Z OR SO ACROSS PORTIONS OF NORTHWEST IOWA. WOULD
EXPECT THIS TO BE PREDOMINATELY LIGHT SNOW ALONG AND NORTHEAST OF A
HURON TO SIOUX FALLS TO SPENCER IOWA LINE...WITH A FEW SNOWFLAKES
EVEN POTENTIALLY MIXING IN AS FAR SOUTH AS AREAS JUST NORTH OF THE
MISSOURI RIVER. THE AFTERNOON HOURS WILL BE DRY...WITH SKIES
BECOMING PARTLY SUNNY. EXPECTING GOOD MIXING AGAIN...AND BASED ON
HOW WARM WE WERE ABLE TO GET YESTERDAY...WENT AHEAD AND BUMPED HIGHS
UP A FEW DEGREES FOR TODAY...MAINLY LOW AND MID 40S.
ANOTHER CLIPPER SYSTEM WILL DROP SOUTHEAST TOWARDS THE AREA LATER
TONIGHT INTO WEDNESDAY. TEMPERATURES TONIGHT ARE TRICKY. WITH CALM
WINDS LOCATIONS IN THE EAST SHOULD DROP RAPIDLY IN THE EVENING
HOURS. MEANWHILE AS CLOUDS INCREASE FROM WEST TO EAST TEMPERATURES
WILL BEGIN TO RISE. TRIED TO SHOW THIS IN THE GRIDS...BUT WOULD NOT
BE SURPRISED IF LOCATIONS EATS OF INTERSTATE 29 END UP A BIT COLDER
THAN CURRENTLY FORECAST. THE CLIPPER SYSTEM ITSELF SEEMS TO BE
TRENDING SOUTHWEST. FOLLOWING A CONSENSUS OF THE NAM...GFS...ECMWF
AND HI RES MODELS SEEMS LIKE A GOOD CALL AT THIS POINT. OVERALL WOULD
THINK THE OVERALL EVOLUTION WILL BE SIMILAR TO WHAT HAPPENED WITH THE
CURRENT SYSTEM...A BROAD AREA OF LIGHT PRECIP AND A EMBEDDED BAND OF
HIGHER QPF ASSOCIATED WITH MID LEVEL FRONTOGENESIS. 500 TO 300 MB Q
VECTOR CONVERGENCE A BIT STRONGER WITH THE SYSTEM TONIGHT...LIKELY
OWING TO A STRONGER UPPER JET. SO WOULD NOT BE SURPRISED IF QPF
AMOUNTS END UP A BIT HIGHER OVERALL. PRECIPITATION TYPE IS AGAIN AN
ISSUE. LOOKS PRETTY SIMILAR TO THIS MORNINGS EVENT IN THAT AN AREA
OF SNOW WILL BE LIKELY ON THE NORTHERN EDGE OF THE BAND. BOUNDARY
LAYER IS A BIT WARMER...SUGGESTING THE AREA THAT SEES MAINLY SNOW
WILL PROBABLY BE PRETTY SMALL. AGAIN ONLY THINKING WE SEE A COATING
TO AN INCH OF ACCUMULATION. WOULD THINK ANYWHERE ALONG AND NORTHEAST
OF A HURON TO SIOUX FALLS TO SIOUX CITY LINE WOULD SEE THE BEST
CHANCE OF THIS LIGHT ACCUMULATION. WILL CONTINUE TO MONITOR
TRENDS...AS IF THINGS WORKS OUT JUST RIGHT...COULD SEE A NARROW AREA
OF 1 TO 2 INCHES OF SNOW...BUT GIVEN THE MARGINAL THERMAL PROFILE
AND QPF PLACEMENT UNCERTAINTY...CONFIDENCE REMAINS LOW. STILL SOME
TIMING DIFFERENCES AS WELL...BUT GENERALLY LOOKS LIKE THE PRECIP
WILL ENTER OUR WEST AROUND 08Z AND APPROACH INTERSTATE 29 AROUND
11Z. PRECIP WILL EXIT BY LATE MORNING OR EARLY AFTERNOON. SKIES WILL
REMAIN MOSTLY CLOUDY THROUGH THE AFTERNOON...WITH ANOTHER DAY OF
HIGHS ONLY IN THE 40S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 422 AM CDT TUE OCT 22 2013
LESS ACTIVE PATTERN RETURNS TO THE AREA WEDNESDAY NIGHT AS WAVE EXITS
TO THE SOUTHEAST. STILL IN COOL NORTHWEST FLOW INTO THURSDAY...SO
WELL BELOW NORMAL TEMPERATURES WILL STICK AROUND FOR ONE MORE DAY.
ANTICIPATE FAIR AMOUNT OF HEATING-DRIVEN CUMULUS IN OUR NORTHEAST
THURSDAY AFTERNOON BASED ON FORECAST SOUNDINGS...WITH SOME MODELS
SQUEEZING OUT A FEW SPRINKLES. HAVE NOT INCLUDED ANY PRECIP MENTION
AT THIS TIME...BUT EVEN IF THEY DO OCCUR...SHOULD BE SPOTTY AND VERY
LIGHT. NORTHWEST WINDS BECOMING GUSTY WITH THE GOOD MIXING AS WELL...
WITH BOTH CLOUDS AND WIND DIMINISHING IN THE EVENING AS SURFACE RIDGE
PUSHES INTO THE CWA FROM THE WEST. TEMPERATURES WEDNESDAY NIGHT AND
THURSDAY NIGHT LIKELY TO BE IN THE MID-UPPER 20S MOST AREAS...WITH
HIGHS THURSDAY AGAIN IN THE 40S.
LONGER RANGE FRIDAY THROUGH MONDAY FEATURES WESTERN CONUS RIDGE
NUDGING EASTWARD THROUGH THE WEEKEND. STRONG WARMING ALOFT ON FRIDAY
NOT LIKELY TO BE FULLY REALIZED AT THE SURFACE...THOUGH MOST AREAS
SHOULD AT LEAST WARM BACK INTO THE 50S...WITH SOME LOWER 60S NOT OUT
OF THE QUESTION IN OUR SOUTHWEST. UPPER WAVE DROPPING FROM CENTRAL
CANADA INTO THE WESTERN GREAT LAKES FRIDAY NIGHT/SATURDAY WILL DRAG A
COOL FRONT SOUTHEAST THROUGH THE NORTHERN PLAINS. MODELS NOW TRENDING
BACK TOWARD HOLDING THE COLDEST OF AIR WITH THIS SYSTEM NORTHEAST OF
OUR AREA...THOUGH WILL LIKELY STILL SEE HIGHS SATURDAY KNOCKED BACK A
FEW DEGREES FROM FRIDAYS READINGS...UPPER 40S IN SOUTHWEST MINNESOTA
TO MID 50S IN OUR SOUTHWEST. ANOTHER PUSH OF WARMER AIR ALOFT SHOULD
HELP HIGHS SUNDAY CLIMB BACK INTO THE 50S TO MAYBE LOWER 60S. THIS
AHEAD OF STRONGER WAVE SLATED TO AFFECT THE REGION EARLY NEXT WEEK.
MODELS DIFFERING ON TIMING SLIGHTLY...WITH GFS FASTER/COOLER THAN
ECMWF BY LATE MONDAY...THOUGH BOTH MODELS CURRENTLY HOLD OFF BETTER
PRECIP CHANCE FOR MOST OF OUR AREA UNTIL MONDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1006 PM CDT MON OCT 21 2013
DEVELOPMENT OF MVFR CEILINGS ON TRACK AS PRECIPITATION BAND WORKS
INTO THE AREA LATE EVENING. WILL CONTINUE TO SEE SOUTHEAST SPREAD
IN MVFR CEILINGS...AND WITH RAIN MIXING WITH OR CHANGING TO SNOW FOR
KHON/KFSD AREAS EASTWARD...WILL SEE PERIODS OF IFR VISIBILITIES
AND CEILINGS AS WELL. EVENTUALLY...CEILINGS WILL BEGIN TO LIFT AS
FLOW TURNS NORTHERLY AND DRIVES LOWER LEVEL DRY AIR SOUTHWARD
DURING THE MORNING HOURS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...JH
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
855 PM CDT WED OCT 23 2013
.UPDATE...
SEVERAL ISSUES WITH FORECAST FOR TONIGHT INCLUDING
TEMPERATURES...SKY COVER...FREEZE WARNING ON THE PLATEAU...AND
EVEN PRECIPITATION. TEMPERATURES HAVE DROPPED RAPIDLY THIS
EVENING WITH MUCH OF THE CWA EAST OF I-65 OUTSIDE OF THE URBAN
NASHVILLE METRO ALREADY IN THE MID 30S PER SURFACE OBS.
HOWEVER...SATELLITE IMAGERY SHOWS THICK MID/HIGH LEVEL CLOUD COVER
NOW ENTERING THE CWA AND SPREADING QUICKLY SOUTHEASTWARD...AND
ONCE CLOUDS COVER A PARTICULAR LOCATION TEMPERATURES SHOULD REMAIN
NEARLY STEADY REMAINDER OF THE NIGHT. BASED ON THIS
REASONING...WILL NOT EXPAND THE FREEZE WARNING WESTWARD TO INCLUDE
MORE COUNTIES ALTHOUGH WAS TEMPTED TO DO SO...BUT DID BUMP UP
TIMING OF FREEZE WARNING START TO 06Z. ALSO ADJUSTED SKY COVER AND
OTHER GRIDS BASED ON LATEST OBS AND TRENDS. RADAR IMAGERY ALSO
SHOWING SOME LIGHT RAIN ACROSS SOUTHERN ILLINOIS SPREADING ACROSS
CENTRAL KENTUCKY AT THIS HOUR. HRRR AND WRF MODELS INDICATE THIS
PRECIP SHOULD REMAIN NORTH OF THE CWA TONIGHT...BUT A STRAY
FLURRY IS NOT COMPLETELY OUT OF THE QUESTION ON THE NORTHERN
PLATEAU. CHANCE IS TOO REMOTE TO MENTION IN THE FORECAST.
ALTHOUGH HAVE NOT HAD MUCH OF A CHANCE TO LOOK AT TEMPERATURES
THE NEXT TWO NIGHTS...LATEST MAV/MET MOS STILL INDICATE POTENTIAL
FOR WIDESPREAD FREEZING TEMPERATURES FOR NEARLY ALL OF MIDDLE
TENNESSEE BOTH THURSDAY AND FRIDAY NIGHTS. TIME HEIGHT
MOISTURE/OMEGA FIELDS SHOW THAT CLOUDS SHOULD NOT BE A FACTOR IN
TEMPS THURSDAY NIGHT...BUT CIRRUS COULD BE A FACTOR ON FRIDAY
NIGHT. NO CHANGES WERE MADE TO INHERITED FREEZE WATCH FOR
THURSDAY NIGHT.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 635 PM CDT WED OCT 23 2013/
AVIATION UPDATE...FOR 00Z TAF PACKAGE...
IR SATELLITE TRENDS CONTINUE TO INDICATE BKN DECK OF 10KFT
CEILINGS ON THE APPROACH FROM THE NW. BELIEVE THIS WILL PREVAIL
THROUGH FIRST 12 HOURS OF TAF PERIOD FOR KCKV AND KBNA. CEILINGS
SHOULD DROP BY MID MORNING AS MOISTURE CONTINUES TO MOVE IN AND
MOISTEN THE COLUMN. COULD BE NEAR MVFR CEILINGS BY AROUND 14Z BUT
KEPT OFFICIAL FORECAST JUST ABOVE FOR NOW.
PREV DISCUSSION... /ISSUED 238 PM CDT WED OCT 23 2013/
DISCUSSION...HIGH PRESSURE NOW BUILDING INTO MIDDLE TENNESSEE
FROM THE WEST, WITH A SCT-BKN CU FIELD COVERING THE NE HALF OF
MIDDLE TENNESSEE THIS AFTERNOON. DESPITE A STRONG NW BREEZE MOST
OF THE DAY, SURFACE PRESSURE GRADIENT IS STARTING TO BREAK DOWN
NOW, SO WINDS HAVE BEGUN TO DIMINISH. EXPECT MOST OF MIDDLE
TENNESSEE TO REMAIN PARTLY TO MOSTLY CLOUDY OVERNIGHT AND THURSDAY
AHEAD OF THE 850 MB TROUGH. DESPITE THIS, TEMPERATURES ALONG THE
CUMBERLAND PLATEAU WILL DROP TO OR BELOW FREEZING TONIGHT, HENCE
THE EARLIER FREEZE WARNING. THE HIGH CENTER WILL GRADUALLY WORK
ITS WAY EASTWARD AS THE MID STATE REMAINS UNDER A COLD AIR MASS.
WITH THE COLD ADVECTION PATTERN EXPECTED TO LAST INTO THE WEEKEND,
FREEZING OVERNIGHT TEMPERATURES WILL BECOME MORE PREVALENT
TOMORROW AND FRIDAY NIGHT, WITH RETURN FLOW PICKING UP ON SATURDAY
AND BRINGING WARMER AIR. HIGHS ON TUESDAY AND WEDNESDAY OF NEXT
WEEK WILL LIKELY HIT THE LOWERS 70`S AHEAD OF THE NEXT BIG SYSTEM,
WHICH THE ECMWF BRINGS THROUGH ON THURSDAY AND THE GFS ON FRIDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY MORNING FOR
TNZ005>011-022>034-056>066-075-077>080-093>095.
FREEZE WARNING FROM 1 AM TO 9 AM CDT THURSDAY FOR TNZ011-032>034-
065-066-078>080.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1050 PM CDT WED OCT 23 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 246 PM CDT WED OCT 23 2013
LATEST RADAR/SATELLITE IMAGERY AND RUC ANALYSIS SHOW A DEEP TROUGH
POSITIONED OVER THE NORTHEAST HALF OF THE UNITED STATES. AMPLE
CLOUD COVER IS ROTATING THROUGH AND AROUND THIS TROUGH WITH SOME
DIURNAL ENHANCEMENT LEADING TO INSTABILITY SNOW AND RAIN SHOWERS
ACROSS THE STATE. MOST OF THE PRECIP HAS REMAINED OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN...BUT THINK SOME SHOWERS REACH INTO THE FOX
VALLEY AND DOOR COUNTY LATER THIS AFTERNOON. BEING DIURNALLY
ENHANCED...SHOWERS AWAY FROM THE SNOW BELTS SHOULD THEN DIMINISH
EARLY THIS EVENING. DUE TO NORTHWEST FLOW PERSISTING...LAKE EFFECT
SNOW SHOWERS AND ACCUMULATION POSSIBILITIES ARE THE MAIN FORECAST
CONCERNS.
TONIGHT...VERY LITTLE CHANGES TONIGHT COMPARED TO THE PAST COUPLE
NIGHTS. COLD CYCLONIC FLOW WILL REMAIN PRESENT THROUGH THE COLUMN
WITH PLENTY OF STRATUS UPSTREAM WHICH WILL LEAD TO A BROKEN CLOUD
DECK. 1000-850MB WINDS DO VEER TO A 330 DIRECTION OVER LAKE
SUPERIOR BY MID TO LATE EVENING...WHICH IS FAVORABLE FOR LAKE EFFECT
PRECIP OVER NORTH-CENTRAL WISCONSIN. COMBINED WITH DELTA T/S AROUND
18C AND AMPLE MOISTURE IN THE 850-700MB LAYER...SHOULD SEE
ACCUMULATING SNOW SHOWERS WITHIN THE SNOW BELTS. PROGGED SOUNDINGS
SHOW THE SATURATED LEVEL BARELY REACHING THE DENDRITIC GROWTH
ZONE...SO SNOW RATIOS SHOULD REMAIN RELATIVELY LOW COMPARED TO WHAT
THEY TYPICALLY ARE IN A LAKE EFFECT SCENARIO. ACCUMULATIONS TWO
NIGHTS AGO MAXED OUT IN THE 2-3 INCH RANGE OVER NORTHERN VILAS
COUNTY...SO THATS ABOUT WHAT IM EXPECTING TONIGHT. WIND SPEEDS ARE
ONLY AROUND 15 KNOTS...SO LOCATIONS OVER THE SOUTHERN HALF OF THE
COUNTY MAY ONLY SEE AN INCH OR LESS. LOWS FIRMLY IN THE 20S.
THURSDAY...LAKE EFFECT SNOW SHOWERS WILL BE ONGOING OVER
NORTH-CENTRAL WISCONSIN...BUT SHOULD BE GRADUALLY WINDING DOWN OVER
THE COURSE OF THE MORNING AS WINDS BACK AROUND AGAIN. WILL SHOW
ANOTHER HALF INCH TO AN INCH IN THE FORECAST. ELSEWHERE...ANOTHER
DAY LIKE TODAY...WITH PARTLY TO MOSTLY CLOUDY SKIES AND ISOLATED TO
SCATTERED FLURRIES AND SPRINKLES. LOW LEVEL TEMPS ARE A DEGREE OR
SO COLDER THAN TODAY SO WILL DROP MAX TEMPS APPROPRIATELY. HIGHS IN
THE MID 30S NORTHWEST TO MID 40S SOUTHEAST.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 246 PM CDT WED OCT 23 2013
LAKE EFFECT SNOW SHOWERS SHOULD CONTINUE FOR AWHILE
THURSDAY NIGHT IN VILAS COUNTY UNTIL WIND FIELD WEAKENS AND
BECOMES MORE WESTERLY AND LOSES FETCH. EXPECT ACCUMULATIONS TO BE
LESS THAN AN INCH. BREEZY AND SLIGHTLY WARMER FRIDAY IN WARM
ADVECTION AHEAD OF THE NEXT COLD FRONT. MODELS HAVE A STRONG LOW
LEVEL JET ACROSS NORTHEAST WISCONSIN FRIDAY NIGHT BUT DRY AIR WILL
HINDER PRECIPITATION PRODUCTION. KEPT A CHANCE OF RAIN OR SNOW IN
THE NORTHEAST PART OF THE FORECAST AREA. A COLD FRONT MOVES
THROUGH SATURDAY MORNING WITH GUSTY WINDS POSSIBLE AS COLD AIR
DEEPENS DURING THE DAY. LAKE EFFECT SNOW POTENTIAL WILL INCREASE
IN NORTHCENTRAL WISCONSIN SATURDAY AFTERNOON AND EVENING AS THE
AIR BECOMES MORE UNSTABLE. A COUPLE OF INCHES LOOK LIKELY AT THIS
POINT. DRY WEATHER EXPECTED SUNDAY AS SURFACE HIGH BUILDS IN. THEN
MODELS DIFFER ON WHAT HAPPENS MONDAY AND TUESDAY AS UPPER FLOW
SPLITS AND A INVERTED TROUGH SETS UP TO OUR SOUTHWEST. LOOKS LIKE
THE BEST PRECIPITATION WILL STAY TO OUR SOUTH THROUGH MIDWEEK.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1042 PM CDT WED OCT 23 2013
NORTHWEST FLOW WILL REMAIN IN PLACE THROUGH THE PERIOD...WITH
ISOLATED TO SCATTERED SHOWER ACTIVITY TIED TO WEAK DISTURBANCES IN
FLOW AND/OR AFTN INSTABILITY WITH COLD AIR OVERHEAD. MAINLY VFR
CIGS...LOWERING THROUGH THE NIGHT. EXCEPTION IS CLOSER TO LAKE
SUPERIOR...WITH LAKE EFFECT SHOWERS EXPECTED TO INCREASE AFTER
MIDNIGHT WITH CIGS FALLING INTO MVFR CAT. SHOWER ACTIVITY TO
DECREASE LATE MORNING THU AS WINDS BACK WEST WITH HIGH EDGING IN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......TE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
644 PM CDT WED OCT 23 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 246 PM CDT WED OCT 23 2013
LATEST RADAR/SATELLITE IMAGERY AND RUC ANALYSIS SHOW A DEEP TROUGH
POSITIONED OVER THE NORTHEAST HALF OF THE UNITED STATES. AMPLE
CLOUD COVER IS ROTATING THROUGH AND AROUND THIS TROUGH WITH SOME
DIURNAL ENHANCEMENT LEADING TO INSTABILITY SNOW AND RAIN SHOWERS
ACROSS THE STATE. MOST OF THE PRECIP HAS REMAINED OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN...BUT THINK SOME SHOWERS REACH INTO THE FOX
VALLEY AND DOOR COUNTY LATER THIS AFTERNOON. BEING DIURNALLY
ENHANCED...SHOWERS AWAY FROM THE SNOW BELTS SHOULD THEN DIMINISH
EARLY THIS EVENING. DUE TO NORTHWEST FLOW PERSISTING...LAKE EFFECT
SNOW SHOWERS AND ACCUMULATION POSSIBILITIES ARE THE MAIN FORECAST
CONCERNS.
TONIGHT...VERY LITTLE CHANGES TONIGHT COMPARED TO THE PAST COUPLE
NIGHTS. COLD CYCLONIC FLOW WILL REMAIN PRESENT THROUGH THE COLUMN
WITH PLENTY OF STRATUS UPSTREAM WHICH WILL LEAD TO A BROKEN CLOUD
DECK. 1000-850MB WINDS DO VEER TO A 330 DIRECTION OVER LAKE
SUPERIOR BY MID TO LATE EVENING...WHICH IS FAVORABLE FOR LAKE EFFECT
PRECIP OVER NORTH-CENTRAL WISCONSIN. COMBINED WITH DELTA T/S AROUND
18C AND AMPLE MOISTURE IN THE 850-700MB LAYER...SHOULD SEE
ACCUMULATING SNOW SHOWERS WITHIN THE SNOW BELTS. PROGGED SOUNDINGS
SHOW THE SATURATED LEVEL BARELY REACHING THE DENDRITIC GROWTH
ZONE...SO SNOW RATIOS SHOULD REMAIN RELATIVELY LOW COMPARED TO WHAT
THEY TYPICALLY ARE IN A LAKE EFFECT SCENARIO. ACCUMULATIONS TWO
NIGHTS AGO MAXED OUT IN THE 2-3 INCH RANGE OVER NORTHERN VILAS
COUNTY...SO THATS ABOUT WHAT IM EXPECTING TONIGHT. WIND SPEEDS ARE
ONLY AROUND 15 KNOTS...SO LOCATIONS OVER THE SOUTHERN HALF OF THE
COUNTY MAY ONLY SEE AN INCH OR LESS. LOWS FIRMLY IN THE 20S.
THURSDAY...LAKE EFFECT SNOW SHOWERS WILL BE ONGOING OVER
NORTH-CENTRAL WISCONSIN...BUT SHOULD BE GRADUALLY WINDING DOWN OVER
THE COURSE OF THE MORNING AS WINDS BACK AROUND AGAIN. WILL SHOW
ANOTHER HALF INCH TO AN INCH IN THE FORECAST. ELSEWHERE...ANOTHER
DAY LIKE TODAY...WITH PARTLY TO MOSTLY CLOUDY SKIES AND ISOLATED TO
SCATTERED FLURRIES AND SPRINKLES. LOW LEVEL TEMPS ARE A DEGREE OR
SO COLDER THAN TODAY SO WILL DROP MAX TEMPS APPROPRIATELY. HIGHS IN
THE MID 30S NORTHWEST TO MID 40S SOUTHEAST.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 246 PM CDT WED OCT 23 2013
LAKE EFFECT SNOW SHOWERS SHOULD CONTINUE FOR AWHILE
THURSDAY NIGHT IN VILAS COUNTY UNTIL WIND FIELD WEAKENS AND
BECOMES MORE WESTERLY AND LOSES FETCH. EXPECT ACCUMULATIONS TO BE
LESS THAN AN INCH. BREEZY AND SLIGHTLY WARMER FRIDAY IN WARM
ADVECTION AHEAD OF THE NEXT COLD FRONT. MODELS HAVE A STRONG LOW
LEVEL JET ACROSS NORTHEAST WISCONSIN FRIDAY NIGHT BUT DRY AIR WILL
HINDER PRECIPITATION PRODUCTION. KEPT A CHANCE OF RAIN OR SNOW IN
THE NORTHEAST PART OF THE FORECAST AREA. A COLD FRONT MOVES
THROUGH SATURDAY MORNING WITH GUSTY WINDS POSSIBLE AS COLD AIR
DEEPENS DURING THE DAY. LAKE EFFECT SNOW POTENTIAL WILL INCREASE
IN NORTHCENTRAL WISCONSIN SATURDAY AFTERNOON AND EVENING AS THE
AIR BECOMES MORE UNSTABLE. A COUPLE OF INCHES LOOK LIKELY AT THIS
POINT. DRY WEATHER EXPECTED SUNDAY AS SURFACE HIGH BUILDS IN. THEN
MODELS DIFFER ON WHAT HAPPENS MONDAY AND TUESDAY AS UPPER FLOW
SPLITS AND A INVERTED TROUGH SETS UP TO OUR SOUTHWEST. LOOKS LIKE
THE BEST PRECIPITATION WILL STAY TO OUR SOUTH THROUGH MIDWEEK.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 640 PM CDT WED OCT 23 2013
NORTHWEST FLOW WILL REMAIN IN PLACE THROUGH THE PERIOD...WITH
ISOLATED TO SCATTERED SHOWER ACTIVITY TIED TO WEAK DISTURBANCES IN
FLOW AND/OR AFTN INSTABILITY WITH COLD AIR OVERHEAD. SHOWERS
MAINLY SNOW THIS AFTN...WILL CONTINUE ACTIVITY INTO THE EVENING.
MAINLY VFR CIGS...LOWERING THROUGH THE NIGHT. EXCEPTION IS CLOSER
TO LAKE SUPERIOR...WITH LAKE EFFECT EXPECTED TO INCREASE THROUGH
THE NIGHT WITH CIGS FALLING INTO MVFR CAT. &&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......TE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1222 PM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT TUE OCT 22 2013
AT 3 AM...A BAND OF LIGHT RAIN AND SNOW EXTENDED FROM CENTRAL IOWA
NORTHWEST TO SOUTHEAST SOUTH DAKOTA. THIS PRECIPITATION IS LOCATED
IN AN AREA OF 900 TO 700 MB FRONTOGENESIS THAT HAS DEVELOP AHEAD
OF A SHORT WAVE TROUGH LOCATED OVER EASTERN SOUTH DAKOTA. THE MESO
MODELS SUGGEST THAT THIS FORCING ALONG WITH THE 280-290K
ISENTROPIC LIFT WILL REMAIN JUST SOUTH AND WEST OF THE FORECAST
AREA. IN ADDITION WITH THE 280-290K CONDENSATION PRESSURE DEFICITS
RUNNING BETWEEN 20 AND 50 MB...THERE MAY BE SOME SATURATION ISSUES
IN NORTHEAST IOWA. RAP BUFKIT SOUNDINGS SHOW THAT THERE WILL BE A
VERY BRIEF PERIOD WHERE THE OMEGA WILL INTERSECT THE DENDRITIC
GROWTH ZONE...BUT ALSO AT THIS TIME THERE IS STILL QUITE A BIT OF
DRY AIR BELOW 800 MB. IT DEFINITELY LOOKS BETTER AS ONE HEADS
SOUTH TO WATERLOO IOWA. DUE TO THIS...KEPT A 20 TO 40 PERCENT
CHANCE OF RAIN AND SNOW BORDERING THE DES MOINES AND DAVENPORT
COUNTY WARNING AREAS BETWEEN 22.10Z AND 22.20Z. THESE TIMES WERE
BASED ON THE MESO MODELS. LIQUID AMOUNTS WILL BE LESS THAN A TENTH
OF AN INCH AND SNOW AMOUNTS WILL BE LESS THAN A HALF INCH SOUTH OF
A ST ANSGAR IOWA TO PLATTEVILLE WISCONSIN.
FOR THIS EVENING...THE MODELS CONTINUE TO SHOW STEEP /7 TO 7.5
C/KM/ SURFACE TO 700 MB LAPSE RATES ACROSS THE FORECAST AREA. THIS
WILL LIKELY KEEP SOME MID CLOUDS ACROSS THE FORECAST AREA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 340 AM CDT TUE OCT 22 2013
ON WEDNESDAY...THE 22.00Z MODELS SHOW THAT ANOTHER SHORT WAVE
TROUGH WILL MOVE SOUTHEAST ACROSS WESTERN AND SOUTHERN IOWA. AS A
RESULT...MUCH OF THE FRONTOGENETIC FORCING AND 280-290K ISENTROPIC
LIFT STAY WELL WEST AND SOUTH OF THE FORECAST AREA. WITH NOT MUCH
LIFT AND 280-290K CONDENSATION PRESSURE DEFICITS RUNNING BETWEEN
30 AND 50 MB... TOOK OUT THE PRECIPITATION CHANCES OUT OF
NORTHEAST IOWA AND SOUTHWEST WISCONSIN.
LIKE THE 21.12Z MODELS...THE 22.00Z MODELS ARE CONTINUING TO TREND
THAT THAT THE WESTERN PERIPHERY OF THE LONG WAVE TROUGH OVER
EASTERN CANADA WILL SHIFT A BIT FURTHER EAST AND THIS WILL SHIFT
THE STORM TRACK INTO THE MINNESOTA ARROWHEAD AND EASTERN WISCONSIN.
AS RESULT...IT DOES NOT LOOK LIKE WE WILL SEE ANOTHER SURGE OF
COLD INTO THE REGION FOR THE WEEKEND. THIS WILL ALLOW TEMPERATURES
TO WARM CLOSER TO NORMAL. IN ADDITION...PRECIPITATION CHANCES LOOK
TO MAINLY TO OUR NORTH AND EAST. HOWEVER CANNOT COMPLETELY TAKE
OUT THE PRECIPITATION CHANCES ACROSS NORTH CENTRAL WISCONSIN...SO
KEPT A 20 PERCENT CHANCE OF RAIN AND SNOW IN TAYLOR COUNTY FOR
FRIDAY NIGHT INTO SATURDAY.
LOOKING AHEAD TO EARLY NEXT WEEK...THE MODELS ARE NOW SHOWING THAT
THE WESTERN RIDGE WILL RETROGRADE WEST AND THAT A LONG WAVE
TROUGH WILL DEVELOP OVER THE INTER MOUNTAIN REGION. AS THIS OCCURS...
THE UPPER LEVEL WINDS WILL SHIFT TO THE WEST AND SOUTHWEST. THIS
WILL ALLOW EVEN WARMER AIR AIR TO MOVE BACK INTO THE AREA. THIS
COULD BE OUR FIRST TASTE OF INDIAN SUMMER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1222 PM CDT TUE OCT 22 2013
DEEP...COLD CYCLONIC NORTHWEST FLOW WILL REMAIN OVER THE AREA
THROUGH MUCH OF THE WEEK. THE LOWER LEVEL NORTH AND NORTHWEST FLOW
IN THIS PATTERN WILL PULL INCREASING LOWER LEVEL MOISTURE SOUTHWARD
AND ACROSS THE TAF SITES FOR THIS AFTERNOON INTO WED. CIGS UPSTREAM
ARE MVFR IN THE 1500-2500 FT RANGE. WITH DIURNAL WARMING/MIXING THIS
AFTERNOON...THESE CIGS EXPECTED TO LIFT INTO THE 3000-3500 FT RANGE
BY LATE IN THE DAY. STEEPER LAPSE RATES AND MDT NORTHWEST WINDS IN
THE 925-800MB RANGE TONIGHT SHOULD KEEP CIGS IN THE 3000-3500FT
RANGE OVERNIGHT. MODEL SOUNDINGS AND RH PROGS ALSO INDICATE STRATO-
CU CIGS TONIGHT SHOULD MAINLY BE VFR. LOWER LEVEL MOISTURE INCREASES
EVEN MORE FOR WED BUT MODEL SOUNDINGS CONTINUE TO SHOW STEEP LOW
LEVEL LAPSE RATES AND DEEPER MIXING TO KEEP CIGS MAINLY VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
609 AM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT TUE OCT 22 2013
AT 3 AM...A BAND OF LIGHT RAIN AND SNOW EXTENDED FROM CENTRAL IOWA
NORTHWEST TO SOUTHEAST SOUTH DAKOTA. THIS PRECIPITATION IS LOCATED
IN AN AREA OF 900 TO 700 MB FRONTOGENESIS THAT HAS DEVELOP AHEAD
OF A SHORT WAVE TROUGH LOCATED OVER EASTERN SOUTH DAKOTA. THE MESO
MODELS SUGGEST THAT THIS FORCING ALONG WITH THE 280-290K
ISENTROPIC LIFT WILL REMAIN JUST SOUTH AND WEST OF THE FORECAST
AREA. IN ADDITION WITH THE 280-290K CONDENSATION PRESSURE DEFICITS
RUNNING BETWEEN 20 AND 50 MB...THERE MAY BE SOME SATURATION ISSUES
IN NORTHEAST IOWA. RAP BUFKIT SOUNDINGS SHOW THAT THERE WILL BE A
VERY BRIEF PERIOD WHERE THE OMEGA WILL INTERSECT THE DEDRITIC
GROWTH ZONE...BUT ALSO AT THIS TIME THERE IS STILL QUITE A BIT OF
DRY AIR BELOW 800 MB. IT DEFINITELY LOOKS BETTER AS ONE HEADS
SOUTH TO WATERLOO IOWA. DUE TO THIS...KEPT A 20 TO 40 PERCENT
CHANCE OF RAIN AND SNOW BORDERING THE DES MOINES AND DAVENPORT
COUNTY WARNING AREAS BETWEEN 22.10Z AND 22.20Z. THESE TIMES WERE
BASED ON THE MESO MODELS. LIQUID AMOUNTS WILL BE LESS THAN A TENTH
OF AN INCH AND SNOW AMOUNTS WILL BE LESS THAN A HALF INCH SOUTH OF
A ST ANSGAR IOWA TO PLATTEVILLE WISCONSIN.
FOR THIS EVENING...THE MODELS CONTINUE TO SHOW STEEP /7 TO 7.5
C/KM/ SURFACE TO 700 MB LAPSE RATES ACROSS THE FORECAST AREA. THIS
WILL LIKELY KEEP SOME MID CLOUDS ACROSS THE FORECAST AREA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 340 AM CDT TUE OCT 22 2013
ON WEDNESDAY...THE 22.00Z MODELS SHOW THAT ANOTHER SHORT WAVE
TROUGH WILL MOVE SOUTHEAST ACROSS WESTERN AND SOUTHERN IOWA. AS A
RESULT...MUCH OF THE FRONTOGENETIC FORCING AND 280-290K ISENTROPIC
LIFT STAY WELL WEST AND SOUTH OF THE FORECAST AREA. WITH NOT MUCH
LIFT AND 280-290K CONDENSATION PRESSURE DEFICITS RUNNING BETWEEN
30 AND 50 MB... TOOK OUT THE PRECIPITATION CHANCES OUT OF
NORTHEAST IOWA AND SOUTHWEST WISCONSIN.
LIKE THE 21.12Z MODELS...THE 22.00Z MODELS ARE CONTINUING TO TREND
THAT THAT THE WESTERN PERIPHERY OF THE LONG WAVE TROUGH OVER
EASTERN CANADA WILL SHIFT A BIT FURTHER EAST AND THIS WILL SHIFT
THE STORM TRACK INTO THE MINNESOTA ARROWHEAD AND EASTERN WISCONSIN.
AS RESULT...IT DOES NOT LOOK LIKE WE WILL SEE ANOTHER SURGE OF
COLD INTO THE REGION FOR THE WEEKEND. THIS WILL ALLOW TEMPERATURES
TO WARM CLOSER TO NORMAL. IN ADDITION...PRECIPITATION CHANCES LOOK
TO MAINLY TO OUR NORTH AND EAST. HOWEVER CANNOT COMPLETELY TAKE
OUT THE PRECIPITATION CHANCES ACROSS NORTH CENTRAL WISCONSIN...SO
KEPT A 20 PERCENT CHANCE OF RAIN AND SNOW IN TAYLOR COUNTY FOR
FRIDAY NIGHT INTO SATURDAY.
LOOKING AHEAD TO EARLY NEXT WEEK...THE MODELS ARE NOW SHOWING THAT
THE WESTERN RIDGE WILL RETROGRADE WEST AND THAT A LONG WAVE
TROUGH WILL DEVELOP OVER THE INTER MOUNTAIN REGION. AS THIS OCCURS...
THE UPPER LEVEL WINDS WILL SHIFT TO THE WEST AND SOUTHWEST. THIS
WILL ALLOW EVEN WARMER AIR AIR TO MOVE BACK INTO THE AREA. THIS
COULD BE OUR FIRST TASTE OF INDIAN SUMMER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 608 AM CDT TUE OCT 22 2013
CLOUD SHIELD ASSOCIATED WITH THE AREA OF LOW PRESSURE OVER
NEBRASKA HAS FOR THE MOST PART STAYED TO THE SOUTH OF BOTH TAF
SITES. HIGHER LEVEL CLOUDS ARE MAKING SLOW EASTWARD PROGRESS AND
ARE EXPECTED TO SPREAD ACROSS BOTH TAF SITES THROUGH THE MORNING.
AS THE DAY PROGRESSES AND THE SURFACE LOW MOVES ACROSS IOWA TOWARD
ILLINOIS...IT IS EXPECTED TO START PULLING DOWN THE LOW LEVEL
MOISTURE IN PLACE OVER NORTHERN MINNESOTA AND WISCONSIN. THIS
SHOULD INITIALLY RESULT IN VFR CEILINGS THIS AFTERNOON AND
EVENTUALLY GOING TO MVFR DURING THE EVENING. SOMEWHAT CONCERNED
THAT THE CEILINGS COULD GO MVFR THIS AFTERNOON AS THESE CURRENTLY
RESIDE OVER NORTHERN WISCONSIN INTO CENTRAL MINNESOTA.
HOWEVER...THINK THE MIXED LAYER WILL GET DEEP ENOUGH BEFORE THE
MOISTURE ARRIVES TO MAKE THE INITIAL CEILINGS BE VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
341 AM CDT TUE OCT 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT TUE OCT 22 2013
AT 3 AM...A BAND OF LIGHT RAIN AND SNOW EXTENDED FROM CENTRAL IOWA
NORTHWEST TO SOUTHEAST SOUTH DAKOTA. THIS PRECIPITATION IS LOCATED
IN AN AREA OF 900 TO 700 MB FRONTOGENESIS THAT HAS DEVELOP AHEAD
OF A SHORT WAVE TROUGH LOCATED OVER EASTERN SOUTH DAKOTA. THE MESO
MODELS SUGGEST THAT THIS FORCING ALONG WITH THE 280-290K
ISENTROPIC LIFT WILL REMAIN JUST SOUTH AND WEST OF THE FORECAST
AREA. IN ADDITION WITH THE 280-290K CONDENSATION PRESSURE DEFICITS
RUNNING BETWEEN 20 AND 50 MB...THERE MAY BE SOME SATURATION ISSUES
IN NORTHEAST IOWA. RAP BUFKIT SOUNDINGS SHOW THAT THERE WILL BE A
VERY BRIEF PERIOD WHERE THE OMEGA WILL INTERSECT THE DEDRITIC
GROWTH ZONE...BUT ALSO AT THIS TIME THERE IS STILL QUITE A BIT OF
DRY AIR BELOW 800 MB. IT DEFINITELY LOOKS BETTER AS ONE HEADS
SOUTH TO WATERLOO IOWA. DUE TO THIS...KEPT A 20 TO 40 PERCENT
CHANCE OF RAIN AND SNOW BORDERING THE DES MOINES AND DAVENPORT
COUNTY WARNING AREAS BETWEEN 22.10Z AND 22.20Z. THESE TIMES WERE
BASED ON THE MESO MODELS. LIQUID AMOUNTS WILL BE LESS THAN A TENTH
OF AN INCH AND SNOW AMOUNTS WILL BE LESS THAN A HALF INCH SOUTH OF
A ST ANSGAR IOWA TO PLATTEVILLE WISCONSIN.
FOR THIS EVENING...THE MODELS CONTINUE TO SHOW STEEP /7 TO 7.5
C/KM/ SURFACE TO 700 MB LAPSE RATES ACROSS THE FORECAST AREA. THIS
WILL LIKELY KEEP SOME MID CLOUDS ACROSS THE FORECAST AREA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 340 AM CDT TUE OCT 22 2013
ON WEDNESDAY...THE 22.00Z MODELS SHOW THAT ANOTHER SHORT WAVE
TROUGH WILL MOVE SOUTHEAST ACROSS WESTERN AND SOUTHERN IOWA. AS A
RESULT...MUCH OF THE FRONTOGENETIC FORCING AND 280-290K ISENTROPIC
LIFT STAY WELL WEST AND SOUTH OF THE FORECAST AREA. WITH NOT MUCH
LIFT AND 280-290K CONDENSATION PRESSURE DEFICITS RUNNING BETWEEN
30 AND 50 MB... TOOK OUT THE PRECIPITATION CHANCES OUT OF
NORTHEAST IOWA AND SOUTHWEST WISCONSIN.
LIKE THE 21.12Z MODELS...THE 22.00Z MODELS ARE CONTINUING TO TREND
THAT THAT THE WESTERN PERIPHERY OF THE LONG WAVE TROUGH OVER
EASTERN CANADA WILL SHIFT A BIT FURTHER EAST AND THIS WILL SHIFT
THE STORM TRACK INTO THE MINNESOTA ARROWHEAD AND EASTERN WISCONSIN.
AS RESULT...IT DOES NOT LOOK LIKE WE WILL SEE ANOTHER SURGE OF
COLD INTO THE REGION FOR THE WEEKEND. THIS WILL ALLOW TEMPERATURES
TO WARM CLOSER TO NORMAL. IN ADDITION...PRECIPITATION CHANCES LOOK
TO MAINLY TO OUR NORTH AND EAST. HOWEVER CANNOT COMPLETELY TAKE
OUT THE PRECIPITATION CHANCES ACROSS NORTH CENTRAL WISCONSIN...SO
KEPT A 20 PERCENT CHANCE OF RAIN AND SNOW IN TAYLOR COUNTY FOR
FRIDAY NIGHT INTO SATURDAY.
LOOKING AHEAD TO EARLY NEXT WEEK...THE MODELS ARE NOW SHOWING THAT
THE WESTERN RIDGE WILL RETROGRADE WEST AND THAT A LONG WAVE
TROUGH WILL DEVELOP OVER THE INTER MOUNTAIN REGION. AS THIS OCCURS...
THE UPPER LEVEL WINDS WILL SHIFT TO THE WEST AND SOUTHWEST. THIS
WILL ALLOW EVEN WARMER AIR AIR TO MOVE BACK INTO THE AREA. THIS
COULD BE OUR FIRST TASTE OF INDIAN SUMMER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1151 PM CDT MON OCT 21 2013
VFR CONDITIONS EXPECTED THROUGH THE PERIOD AS A WEATHER SYSTEM
TRAVELS SOUTH OF THE TAFS. PROLONGED NORTHWEST FLOW AND THE
WEATHER SYSTEM IN IOWA WILL WILL BRING CLOUDS OF THE VFR VARIETY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1152 PM CDT MON OCT 21 2013
.UPDATE...
ISSUED AT 938 PM CDT MON OCT 21 2013
HAVE BEEN FOLLOWING THE TRENDS OF THE HRRR AND RAP ALL EVENING
AND THE 22.00Z NAM HAS NOW COME IN AS WELL...ALL WITH THE SNOW
STRIPE FURTHER SOUTH IN IA BY 1-2 COUNTIES. HAVE TRENDED THE
FORECAST THAT WAY WITH REDUCED PRECIPITATION CHANCES...AND LESS
SNOWFALL /NOW ABOUT 0.5 INCHES VERSUS 1 INCH/ IN FAR SOUTH. WITH
CLEAR SKIES AND SOME LOW-LEVEL RIDGING AND LIGHT WIND...HAVE ALSO COOLED
LOW TEMPERATURES ACROSS THE SOUTH TOO.
FORECAST SHOULD BE UP TO THE WEB SITE AND IN PRODUCTS SHORTLY.
UPDATE ISSUED AT 702 PM CDT MON OCT 21 2013
HAVE BEEN MONITORING CURRENT CONDITIONS ACROSS THE DAKOTAS AND INTO
IOWA...AS WELL AS MODEL FORECASTS WITH THE SNOW SWATH COMING
THROUGH IA/MN LATER TONIGHT. OVERALL OPINION IS THAT THIS WILL BE
A PRETTY NARROW BAND OF INTENSE LIFT WITH THE HIGHEST PROBABILITY
OF SNOW TO THE SOUTH OF THE FORECAST AREA. LATEST HRRR RUNS ARE
SLOWING THE ONSET OF THE SNOW JUST SOUTH OF THE FORECAST
AREA...BUT REALLY AGREE WELL WITH THE LATEST RUC RUNS AND 21.18Z
NAM. THIS WILL BE A CLOSE ONE...WITH THE BAND AFFECTING WATERLOO
AND DUBUQUE. 21.18Z NAM COBB DATA SUGGESTS ABOUT 5 INCHES OF
SNOWFALL THERE...BUT THIS DOES NOT TAKE INTO ACCOUNT MELTING. 21.18Z
GFS COBB MUCH MORE TAME WITH ABOUT AN INCH. SNOW RATES IN THE
BAND WILL CAUSE ACCUMULATIONS AND SEEMS DMX/DVN WITH A 1-3 INCH
BAND SEEMS RIGHT FROM SIOUX FALLS SD TO THE QUAD CITIES IA. OELWEIN
TO NORTH DUBUQUE HAVE THE BEST CHANCE OF SEEING AN INCH IN THE LA
CROSSE FORECAST AREA.
FORECAST ACROSS THE SOUTH LOOKS GOOD AND HAVE NOT CHANGED IT AT
THIS TIME. HAVE DECREASED CLOUDS FOR THE EVENING WITH CLEARING
WORKING IN SOUTH OF I-94. WINDS WILL DROP OFF QUICKLY THIS EVENING
AND THINKING THERE WILL BE ENOUGH TO HOLD TEMPS ABOVE DEWPOINTS
BEFORE CLOUDS ARRIVE FROM THE WEST. BUT...FOG HAS CROSSED MY MIND
WEST OF MISS RIVER WHERE SURFACE RIDGING IS BUILDING IN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 307 PM CDT MON OCT 21 2013
THE MAIN FOCUS FOR TONIGHT INTO TOMORROW IS WITH THE CHANCES FOR
AN ACCUMULATING SNOW ACROSS NORTHEAST IOWA.
CURRENTLY...A CLOSED MID LEVEL LOW IS DRIFTING EAST ACROSS
NORTHERN MINNESOTA WHILE A BROAD SURFACE LOW IS CENTERED OVER
EASTERN ONTARIO. THE BROAD CYCLONIC FLOW EXTENDS ACROSS MUCH OF
THE UPPER MISSISSIPPI RIVER VALLEY AND HAS LEAD TO AN EXTENSIVE
STRATOCUMULUS FIELD THAT ALSO HAS PRODUCED SOME OCCASIONAL VERY
LIGHT FLURRIES. THE MORE INTENSE SNOW SHOWERS HAVE BEEN FURTHER
NORTH CLOSER TO THE CLOSED MID LEVEL LOW AND SURFACE INVERTED
TROUGH NEAR LAKE SUPERIOR. GIVEN THE CELLULAR LOOK TO THE CLOUDS
AND THAT WEAK SURFACE HIGH PRESSURE WILL BE MOVING IN...SOME
CLEARING MAY TAKE PLACE FOR A PERIOD THIS EVENING BEFORE THE NEXT
SYSTEM MOVES IN AND BRINGS HIGH LEVEL CLOUD COVER IN WITH IT.
THIS NEXT SYSTEM IS CURRENTLY IN SOUTH CENTRAL CANADA AND WILL
DIVE SOUTHEAST ACROSS THE DAKOTAS ON INTO IOWA TONIGHT INTO
TOMORROW MORNING. A NARROW BAND OF PRECIPITATION WILL ACCOMPANY
THIS LOW WITH THE BEST LOW LEVEL FRONTOGENESIS STAYING JUST
SOUTHWEST OF THE FORECAST AREA IN CENTRAL/EASTERN IOWA. THE 21.12Z
MODEL SUITE IS ALL IN GOOD AGREEMENT WITH THE TIMING/TRACK OF THIS
SYSTEM WITH SOME LIGHT PRECIPITATION MAKING IT INTO NORTHEAST
IOWA...MAINLY FROM CHARLES CITY TO OELWEIN. THERMAL PROFILES SHOW
THAT THERE IS ICE PRESENT THROUGHOUT THE EVENT AND THAT IT WILL BE
COLD ENOUGH TO BE ALL SNOW AS WELL. WITH THE BETTER FORCING TO THE
SOUTH...ONLY EXPECT SOME VERY MINOR ACCUMULATIONS AT A HALF INCH
OR LESS IN THAT CHARLES CITY TO OELWEIN CORRIDOR. THE MAIN PERIOD
FOR THIS SNOW APPEARS TO BE BETWEEN ABOUT 3AM AND 9AM TUESDAY
MORNING BEFORE THE SYSTEM TRACKS TO THE SOUTHEAST OF THE REGION.
TEMPERATURES WILL TEMPORARILY IMPROVE FOR A BRIEF PERIOD TUESDAY
AS 850MB TEMPERATURES GO FROM AROUND -8C AT PRESENT UP TO -4C
BEFORE THE NEXT COLD SURGE DROPS THEM BACK DOWN TO AROUND -8C IN
THE AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 307 PM CDT MON OCT 21 2013
ANOTHER MID LEVEL SHORT WAVE TROUGH WILL DIVE SOUTH ALONG THE
WESTERN PERIPHERY OF THE LONG WAVE TROUGH THAT IS STUCK ACROSS THE
NORTHEASTERN US AND EASTERN CANADA ON WEDNESDAY. THIS WILL BRING
ANOTHER SURFACE LOW WITH PRECIPITATION THROUGH CENTRAL IOWA WITH
THE QUESTION BEING WHETHER ANY OF IT WILL GET INTO NORTHEAST IOWA.
THE TREND APPEARS TO BE TAKING THIS ONE FURTHER TO THE SOUTH THAN
THE LOW COMING THROUGH TONIGHT. THERE IS ENOUGH OF A POSSIBILITY
THAT SOME OF THIS PRECIPITATION COULD GET INTO NORTHEAST IOWA...SO
HAVE LEFT SOME SMALL CHANCES FOR A SNOW CHANGING TO RAIN MIX IN
THERE. WITH THIS SYSTEM COMING THROUGH THE REGION MORE SO DURING
THE DAY THAN OVERNIGHT...SURFACE TEMPERATURES WILL LIKELY WARM
ENOUGH TO CAUSE THAT CHANGE OVER.
THE REST OF THE WEEK LOOKS TO STAY ON THE COLD SIDE WITH 850MB
TEMPERATURES IN THE -6C TO -8C RANGE UNTIL FRIDAY WHEN SOME LOW
LEVEL WARM ADVECTION FINALLY KICKS IN AS THE UPPER TROUGH BREAKS
DOWN AND SHIFTS EAST. THE WAA WILL BEGIN AS ANOTHER SHORT WAVE
DIVES INTO THE GREAT LAKES FRIDAY/SATURDAY. THE 21.12Z GFS IS A
TAD FASTER WITH THIS FEATURE THAN THE 21.12Z ECMWF AND BRINGS
TEMPS BACK DOWN A BIT FASTER AS WELL. IF THE ECMWF PANS
OUT...HIGHS ON SATURDAY COULD BE A LITTLE HIGHER IN THE
50S...PARTICULARLY IN NORTHEAST IOWA/SOUTHWEST WISCONSIN.
THE LONG TERM GUIDANCE HAS THEN COME AROUND TO SHOW SOME BROAD
TROUGHING DEVELOPING IN THE NORTHWESTERN US WHICH WILL LEAD TO AN
ELONGATED SURFACE LOW FORMING ACROSS THE CENTRAL PLAINS SUNDAY
NIGHT INTO MONDAY. THIS FEATURE WILL BE OUR NEXT SHOT FOR A
WIDESPREAD RAIN EVENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1151 PM CDT MON OCT 21 2013
VFR CONDITIONS EXPECTED THROUGH THE PERIOD AS A WEATHER SYSTEM
TRAVELS SOUTH OF THE TAFS. PROLONGED NORTHWEST FLOW AND THE
WEATHER SYSTEM IN IOWA WILL WILL BRING CLOUDS OF THE VFR VARIETY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
330 AM EDT THU OCT 24 2013
.DISCUSSION...
...MUCH DRIER AND COOLER WEATHER WILL CONTINUE...
...CHOPPY CONDITIONS OVER THE ATLANTIC AND GULF STREAM...
CURRENT...
COLD FRONT HAS PUSHED SOUTH OF THE PENINSULA THIS MORNING. SURFACE
HIGH PRESSURE WITH NORTH TO NNE FLOW IS BUILDING SOUTHWARD IN ITS
WAKE. UPPER FLOW IS HIGHLY DIVGT OVHD AS AREA IS FIRMLY IN RR QUAD
OF 120-140KT JETSTREAK AND IS COMBINING WITH LARGE SWATH OF RH
VALUES AOA 80 PCT AOA 600MB TO PRODUCE A HIGH CLOUD (CI/CS/AS)
CANOPY WHICH HAS THICKENED AND BECOME MUCH MORE WIDESPREAD OVER THE
PENINSULA SINCE 00Z. THIS IS TEMPERING THE NOCTURNAL TEMPERATURE
FALL BY A SOLID 2-5F DEGREES ACROSS THE ENTIRETY OF THE CWA...AND
SUSPECT ACTUAL MINS WILL WIND UP BEING A CAT OR SO HIGHER THAN
PREVIOUSLY ADVERTISED.
TODAY/TONIGHT...
MODIFIED COOL ADVECTION PATTERN WILL CONTINUE AS N-NNW DRAINAGE
WINDS GRADUALLY VEER TO NNE-NE DURING THE DAY. UPPER LEVEL PROGS
SHOW UPPER DIVG WILL BE SLOW TO WEAKEN WHILE RH VALUES ABOVE H50
CONTINUE TO SUPPORT SIGNIFICANT OPAQUE HIGH CLOUD COVER MOST OF THE
DAY....POSSIBLY ERODING SOME LATE ACROSS THE NORTH. CERTAINLY...IR
SATELLITE SHOWS OVERCAST TO BROKEN CONDITIONS WELL UPSTREAM COVERING
THE EASTERN GOMEX. WITH THAT IN MIND...WENT AHEAD AND MAKE
SIGNIFICANT INCREASE IN PCT COVERAGE OF OPAQUE CLOUD COVER AND
TWEAKED WORDING TO SHOW CONSIDERABLE HIGH CLOUDS FOR ALL AREAS
TODAY. TEMPS WILL PEAK OUT IN THE 70S...AND IF CLOUDS REMAIN THICK
ENOUGH TO BLOCK OUT SIGNIF SUN...DAY SHIFT MAY NEED TO SHAVE A
COUPLE DEGS FROM THOSE NUMBERS.
EXPECT HIGH CLOUDS TO ERODE AND THIN OUT THIS EVENING INTO TONIGHT.
COULD SEE SOME MARINE "COOL AIR" SC BEGIN TO IMPINGE ON COASTAL
AREAS AS SFC-H85 WINDS BECOME ONSHORE. THIS WILL DEPEND UPON THE
EXTENT OF THEIR GENERATION IMMEDIATELY UPSTREAM OVER THE STILL WARM
ATLC SHELF WATERS/GULF STREAM. MINS GENERALLY IN THE U50S/L60S WITH
SOME M50S NEAR THE OCALA FOREST/LAKE GEORGE REGION.
FRI-SAT...
A POLAR AIRMASS BUILDING DOWN THE LEE SIDE OF THE NRN ROCKIES WILL
REINFORCE AN H100-H70 ANTICYCLONE CENTERED NEAR THE TX/LA BORDER BY
DAYBREAK FRI. THE RESULTING DOME OF HIGH PRES WILL BLANKET MOST OF
THE CONUS E OF THE HIGH PLAINS AND WILL BE THE DOMINANT WX FEATURE
FOR CENTRAL FL THRU THE END OF THE WEEK. A STABLE AND SUBSIDING
AIRMASS WITH MAX PWAT VALUES AOB 0.9" WILL PRECLUDE ANY MEANINGFUL
SKY COVER IN THE FCST...LET ALONE ANY PRECIP.
NRLY FLOW WILL PREVAIL THRU THE H100-H70 LYR...SLOWLY VEERING TO THE
NE BLO H85 AS THE HIGH PRES RIDGE DRIFTS ACRS THE DEEP SOUTH WHILE
SLOWLY WEAKENING. COOL AIR ADVECTION GENERATED BY THIS FLOW REGIME
WILL KEEP TEMPS BLO CLIMO AVG. AFTN TEMPS WILL RANGE FROM THE M/U70S
ALONG THE COAST TO THE U70S/L80S INTERIOR. PREDAWN TEMPS WILL HAVE A
WIDER RANGE AS THE DVLPG NE SFC WINDS PUSH OCEAN MODIFIED AIR
ONSHORE ALONG THE SPACE AND TREASURE COAST...KEEPING READINGS IN THE
L/M60S. MCLR SKIES AND LIGHT WINDS OVER THE INTERIOR WILL RESULT IN
STRONG RADIATIONAL COOLING THAT WILL ALLOW A LIGHT DRAINAGE FLOW
WILL DEVELOP...ALLOWING MINS TO FALL INTO THE M50S N OF I-4 AND INTO
THE U50S ALONG THE NORTH SHORE OF LAKE OKEECHOBEE.
SUN-WED...
HI PRES RIDGE OVER THE DEEP SOUTH WILL LIFT INTO THE MID ATLC AND
MERGE WITH A NEW CANADIAN RIDGE OVER THE ERN SEABOARD EARLY NEXT
WEEK. AS A RESULT...SHALLOW NE FLOW ON SUN WILL DEEPEN THRU TUE
BEFORE VEERING TO THE E ON WED. THE ONSHORE FLOW WILL ALLOW OCEAN
MOISTURE TO PUSH BACK ACRS THE EAST CENTRAL PENINSULA...ALLOWING THE
DRY AND STABLE AIRMASS TO MODIFY.
NEITHER GFS/ECMWF NUMERICAL MODELS INDICATE MUCH IN THE WAY OF
PRECIP WITH THIS DVLPG WX PATTERN...BOTH PREFER TO KEEP POPS LARGELY
AOB 15PCT. HOWEVER...PERSISTENT E/NE FLOW PATTERNS SUCH AS THIS
INVARIABLY MANAGE TO PUSH LCL MOISTURE POCKETS ONSHORE FROM TIME TO
TIME...RESULTING IN ISOLD COVERAGE. ANY SUCH PRECIP WOULD HAVE
MINIMAL IMPACT AS NE FLOW PATTERNS DO NOT SUPPORT DEEP CONVECTION IN
CENTRAL FL.
THE ONSHORE FLOW WILL PUSH ENOUGH OCEAN MOISTURE ONSHORE TO ALLOW
SFC DEWPOINTS TO CLIMB INTO THE L/M60S OVER THE INTERIOR...M/U60S
ALONG THE COAST...INTO EARLY NEXT WEEK. THE RESULTING WARMING TREND
WILL PUSH MAX TEMPS BACK TO NEAR CLIMO AVG IN THE L/M80S. MIN TEMPS
WILL WARM INTO THE L/M60S INTERIOR AND N OF THE CAPE...AND INTO THE
U60S/L70S ALONG THE SPACE AND TREASURE COASTS BY THE MIDDLE OF NEXT
WEEK.
&&
.AVIATION...VFR WITH AOA BKN-OVC150 ALL SITES.
&&
.MARINE...
TODAY/TONIGHT...CHOPPY BOATING CONDITIONS IN STORE WITH NRLY FLOW
OF AROUND 15KT THIS MORNING SUBSIDING IN THE AFTERNOON. SHORT PERIOD
WIND CHOP WILL PRODUCE SEAS OF 3-4FT NEAR SHORE...AND AROUND 5FT IN
THE GULF STREAM. WINDS AND SEAS WILL DECREASE JUST A BIT FROM LATE
AFTERNOON INTO TONIGHT. PLANE TO KEEP CAUTIONARY STATEMENT FOR THE
GULF STREAM UP THIS MORNING DUE TO THE VERY STEEP AND CHOPPY SEAS.
FRI-SAT...POOR BOATING CONDITIONS TO END THE WEEK AS A LARGE HI PRES
RIDGE BUILDS FROM THE MIDWEST INTO THE DEEP SOUTH. POSITION OF THE
RIDGE WILL GENERATE A MODERATE TO FRESH N/NE BREEZE ON FRI...BCMG
GENTLE TO MODERATE FROM THE NE ON SAT. SEAS BUILDING FROM 2-4FT TO
3-5FT ON FRI...HOLDING STEADY THRU SAT. WHILE TOTAL SEA HEIGHTS ARE
EXPECTED TO REMAIN BLO THE NEED FOR ANY STATEMENTS...SIGNIFICANT
WIND CHOP IS EXPECTED DUE TO THE OPPOSING NERLY BREEZE AND SRLY GULF
STREAM COMPONENT. SEAS WILL BE TREACHEROUS.
SUN-MON...RIDGING OVER THE DEEP SOUTH/NRN GOMEX WILL MAINTAIN A
GENTLE TO MODERATE NE BREEZE INTO EARLY NEXT WEEK. WINDS MAY FRESHEN
OVER THE S OF SEBASTIAN INLET LATE MON AFTN AS THE RIDGE INTERACTS
WITH AN ERLY WAVE OVER THE CENTRAL BAHAMAS. SEAS 3-4FT EARLY SUN...
BUILDING TO 4-5FT OVER THE OFFSHORE LEG LATE BY LATE MON NIGHT.
&&
.FIRE WEATHER...
MARGINALLY LOW MIN RH VALUES BOTTOMING IN THE M-U30S TODAY FOR AN
HOUR OR TWO NORTH OF THE INTERSTATE 4 CORRIDOR. STRONG ADVECTION OF
EVEN DRIER AIR WILL OCCUR THROUGH FRI AFTN THAT WILL PUSH LOW SFC RH
VALUES BLO 35PCT FOR 4-6HRS NEAR AND NORTH OF THE I-4 CORRIDOR. RH
VALUES WILL RECOVER BACK ABV 40PCT OVER THE WEEKEND AS SFC/TRANSPORT
WINDS VEER TO THE NE AND PUSH OCEAN MODIFIED AIR BACK ACRS THE
STATE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 75 57 78 59 / 0 0 0 10
MCO 76 58 81 58 / 0 0 0 10
MLB 76 62 78 63 / 0 0 10 10
VRB 77 64 80 62 / 0 0 10 10
LEE 76 58 80 55 / 0 0 0 10
SFB 77 58 81 58 / 0 0 0 10
ORL 78 59 81 58 / 0 0 0 10
FPR 77 64 80 63 / 0 0 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...CRISTALDI
LONG TERM....BRAGAW
AVIATION...CRISTALDI
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
103 AM EDT THU OCT 24 2013
.SYNOPSIS...
HIGH PRESSURE AND A MUCH DRIER AIR MASS WILL MOVE INTO THE AREA
TONIGHT AND THEN PERSIST THROUGH THURSDAY. AN ARCTIC-LIKE COLD
FRONT WILL MOVE THROUGH ON FRIDAY WITH A LARGE AREA OF COOL HIGH
PRESSURE ENCOMPASSING THE REGION BEHIND IT. HIGH PRESSURE WILL
REMAIN THE DOMINANT FEATURE THROUGH EARLY NEXT WEEK ALTHOUGH
TEMPERATURES WILL BEGIN TO MODIFY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A CONSIDERABLY DRIER AND COOLER AIRMASS CONTINUES TO ADVECT INTO
THE REGION OVERNIGHT. HIGH PRESSURE IS FORECAST TO MOVE INTO
WEST-CENTRAL GEORGIA BY SUNRISE...ALLOWING FOR A GRADUAL RELAXING
OF THE PRESSURE GRADIENT. SHOULD SEE MODEST RADIATIONAL PROCESSES
TAKE HOLD AS A RESULT...ESPECIALLY ACROSS INTERIOR SOUTHEAST
GEORGIA WHERE THE BOUNDARY LAYER COULD COMPLETELY DECOUPLE. LOWS
FROM THE UPPER 30S ACROSS THE HIGHER TERRAIN OF JENKINS-SCREVEN-
ALLENDALE COUNTIES TO THE UPPER 40S/LOWER 50S AT THE BEACHES LOOK
ON TARGET FOR NOW.
MIDNIGHT UPDATE TWEAKED A FEW TEMPS AND DEW POINTS...ALL OTHER
GRIDDED ELEMENTS ON TRACK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
THURSDAY...THE AREA WILL REMAIN UNDER ZONAL FLOW WITH WNW WINDS OF
20-25 KT AROUND 850 MB. COLD ADVECTION WILL CONTINUE AS A 1025 MB
HIGH PRESSURE SYSTEM SHIFTS SOUTHEAST TOWARD THE SOUTHEAST STATES.
ANOTHER DAY OF CLEAR SKIES AND DRY AIR WILL OCCUR...WITH HIGH
TEMPERATURES AROUND 70 DEGREES. COOL TEMPS IN THE LOWER TO MIDDLE
40S EXPECTED THURSDAY NIGHT AS WEAK COLD ADVECTION CONTINUES.
AN ARCTIC-LIKE FRONT WILL DROP SOUTH THROUGH THE AREA FRIDAY MORNING
WITH AN EXPANSIVE COLD...DRY 1028 MB HIGH OVERSPREADING THE EASTERN
UNITED STATES. THE DOWNSLOPE INFLUENCE WEAKENS ON FRIDAY SO THERE
WILL BE LESS IN THE WAY OF COMPRESSIONAL HEATING TO OFFSET THE COLD
ADVECTION. THUS HIGH TEMPS WILL ONLY REACH THE MIDDLE 60S IN
SOUTHERN SC AND UPPER 60S IN SOUTHEAST GA.
FRIDAY NIGHT LOOKS TO BE THE COLDEST OF THE SEASON THUS FAR. COLD
HIGH PRESSURE SETTLING OVER THE AREA WITH CLEAR SKIES AND FAIRLY
LIGHT WINDS WILL ALLOW TEMPERATURES TO PLUMMET AFTER SUNSET. WE
LOWERED TEMPERATURES A FEW DEGREES...WITH READINGS AS LOW AS 34
DEGREES FAR INLAND TO AROUND 40 IN THE BELT CLOSER TO THE COAST.
GEOSTROPHIC WINDS WILL BE LESS THAN 15 KT OVERNIGHT...A BIT LOWER
FARTHER INLAND AS THE GRADIENT BECOMES LESS TIGHT. WITH OVERNIGHT
DEWPOINTS RANGING FROM 28-31...THERE STANDS A DECENT CHANCE THAT
SOME OF OUR RURAL INLAND ZONES MAY EXPERIENCE SCATTERED FROST SO WE
WILL INCLUDE THIS POSSIBILITY IN THE HAZARDOUS WEATHER OUTLOOK.
DESPITE SUNNY SKIES...SATURDAY WILL REMAIN COOL DUE TO THE COLD
AIRMASS IN PLACE SO HIGH TEMPS WILL ONLY REACH THE MIDDLE 60S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
FORECAST CONFIDENCE IN THE LONG TERM PERIOD CONTINUES TO BE GOOD.
OVERALL THE PERIOD WILL BE QUIET WITH SURFACE HIGH PRESSURE BEING
THE PRIMARY FEATURE. WEAK HIGH PRESSURE WILL COVER THE AREA FOR THE
LATTER PART OF THE WEEKEND AND INTO MONDAY. THIS WEAK PRESSURE
PATTERN WILL THEN EVENTUALLY BE REPLACED BY LOW LEVEL NORTHEAST FLOW
AS A STRONGER 1035 MB SURFACE HIGH BUILDS IN NORTHEAST OF THE REGION
BY TUESDAY. WE MAY SEE A SUBTLE COASTAL TROUGH DEVELOP OFFSHORE AND
GENERATE A FEW SHOWERS OVER THE WATERS...BUT LAND AREAS WILL REMAIN
DRY. TEMPS WILL GRADUALLY MODERATE BY EARLY NEXT WEEK...WITH HIGHS
IN THE MID 70S AND LOWS IN THE LOW/MID 50S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
VFR. LIGHT WINDS.
EXTENDED AVIATION OUTLOOK...VFR. BREEZY CONDITIONS FRIDAY.
&&
.MARINE...
OVERNIGHT...HIGHER RESOLUTION RAP AND H3R MODELS SHOW A
STRONGER SECONDARY WIND SURGE WORKING DOWN THE COAST EARLY
THIS MORNING AS ANOTHER PUSH OF COLD AIR ADVECTION MOVES THROUGH.
SHOULD SEE AT LEAST FREQUENT GUSTS TO 25 KT THROUGH ABOUT 3-4 AM.
SEAS WILL RANGE FROM 2-4 FT NEARSHORE WATERS TO 4-5 FT OFFSHORE
WATERS. WE EXTENDED ADVISORIES FOR 3 MORE HOURS UNTIL TRENDS
INDICATE THAT THE LAST SURGE HAD BEGUN TO EBB.
THURSDAY THROUGH SUNDAY...CONDITIONS WILL START OUT RELATIVELY
QUIET ON THURSDAY AS WEAKER HIGH PRESSURE SITS ACROSS THE REGION.
THIS WILL CHANGE ON FRIDAY AS A STRONG COLD FRONT PUSHES THROUGH
THE REGION. MUCH COOLER AIR WILL RUSH ACROSS THE WARMER
WATERS...AND GOOD MIXING PROFILES WILL DEVELOP. NORTHWEST TO NORTH
WINDS WILL STEADILY STRENGTHEN THROUGH THE DAY FRIDAY AND
ESPECIALLY DURING THE EVENING HOURS. WE CURRENTLY SHOW WINDS/SEAS
JUST BELOW SMALL CRAFT ADVISORY THRESHOLDS THOUGH A BRIEF PERIOD
OF ADVISORY CONDITIONS IS POSSIBLE ON THE OFFSHORE GA WATERS LATE
FRIDAY INTO FRIDAY NIGHT. CONDITIONS WILL IMPROVE SATURDAY INTO
SUNDAY AS HIGH PRESSURE REMAINS IN CONTROL AND THE PRESSURE
GRADIENT RELAXES.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR
AMZ350-352-354-374.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...JRL
LONG TERM...BSH
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS GOODLAND KS
229 AM MDT THU OCT 24 2013
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 229 AM MDT THU OCT 24 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS NW FLOW STILL IN PLACE
ACROSS NORTHERN AND CENTRAL PLAINS WITH CONFLUENT FLOW OVER THE
CENTRAL ROCKIES. AT THE SURFACE A COLD FRONT HAS STALLED ALONG THE
FRONT RANGE...EXTENDING SOUTH ACROSS THE TEXAS PANHANDLE.
IN THE NEAR TERM...DESPITE LITTLE IN THE WAY OF DEVELOPMENT SO FAR
EARLY THIS MORNING PATCHY FOG/STRATUS STILL SEEMS REASONABLE OVER
WESTERN LOCATIONS WITH TEMPS BEGINNING TO COOL TO WITH A FEW
DECREES OF TD VALUES. NAM/RAP/HRRR STILL SHOW BL MOISTURE
APPROACHING SATURATION IN THE WEST...WITH SOME VISIBILITY
RESTRICTIONS ADVERTISED BY MET GUIDANCE AND NAM. NOT REALLY
CONFIDENT IN COVERAGE...SO I PLAN ON LEAVING ONGOING FORECAST IN
PLACE.
WITH STORM TRACKS WELL NORTH AND SOUTH OF OUR CWA...AND
DRY AIR MASS (BELOW 700MB) IN PLACE OVER OUR CWA THROUGH SATURDAY
NIGHT I EXPECT DRY CONDITIONS TO CONTINUE. TEMPS TODAY WILL BE
ABOUT 10-15F COOLER THAN YESTERDAY (VALUES IN THE 50S)...WITH
COOLER POST FRONTAL AIR MASS IN PLACE. AS A SHORTWAVE TROUGH
PASSES OVER THE NORTHERN PLAINS FRIDAY AND CLOSED LOW OVER
SOUTHERN PLAINS (BOTH OUTSIDE OF OUR AREA OF CONCERN...WE WILL
BEGINNING OT SEE A SHIFT IN THE UPPER PATTERN ALLOWING FOR A
STRENGTHENING OF THE LEE TROUGH AND LIFTING OF A WARM FRONT OVER
OUR CWA. IN RESPONSE BREEZY/MILD CONDITIONS ARE EXPECTED
FRIDAY...WITH ONLY MID-HIGH CLOUDS IN OUR SOUTH. A COLD FRONT WILL
THEN DROP SOUTH BY SATURDAY MORNING WITH A BREEZY NW WIND DURING
THE MORNING HOURS. TEMPS MAY BE A LITTLE COOLER...HOWEVER THERE IS
NOT A LARGE DROP IN TEMPS ALOFT BEHIND THIS FROPA SO WE WILL
LIKELY STAY NEAR SEASONAL VALUES (60S).
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 229 AM MDT THU OCT 24 2013
SUMMARY...DRY AND MILD TO START NEXT WEEK BEFORE BECOMING COLDER
WITH A CHANCE OF WINTRY PRECIP BY MID-WEEK.
SUNDAY...FORECAST HAS BEEN LOOKING LIKE A LOCK FOR THE PAST FEW DAYS
WITH HIGHS IN THE LOW 70S UNDER THE INFLUENCE OF SOME MINOR RIDGING
AND WARM AIR ADVECTION.
MONDAY...A TRANSITIONAL DAY...PROBABLY. GUIDANCE HAS BEEN VERY
INCONSISTENT WITH THE MON-TUES-WED PERIOD FOR THE PAST FEW
DAYS...AND THE 00Z SUITE IS NOT ANY BETTER THAN EARLIER CYCLES.
GEM/ECMWF DEPICT THE COLD FRONT PUSHING SOUTH MONDAY INTO EARLY
TUESDAY...WHILE THE GFS DELAYS THE ARRIVAL UNTIL LATE TUESDAY.
BECAUSE OF THIS THE GFS DEPICTS A MILDER MONDAY WHILE OTHER GUIDANCE
INDICATES INCREASING CLOUDINESS AND ARRIVAL OF THE COLD LIMITING
HIGH TEMPS. THE GEFS MEMBERS SHOW A LARGE SPREAD...INCLUDING
DEPICTING SOLUTIONS MORE IN LINE WITH OTHER GUIDANCE. ULTIMATELY AM
THINKING IT WILL TURN OUT SOMEWHERE IN THE MIDDLE WITH WEAK WAA IN
EASTERN PARTS OF THE CWA AND INCREASING CLOUDS IN THE WEST.
TUESDAY AND WEDNESDAY...VERY LITTLE CONFIDENCE WHATSOEVER FOR THE
REST OF THE WEEK. GEFS/ECMWF ENS ARE ALL OVER THE PLACE...AND AS WPC
POINTS OUT BY TUES THE SYNOPTIC SOLUTIONS ARE MORE THAN 1000 MILES
APART AND THE SPREAD ONLY GROWS FROM THERE. BECAUSE OF THIS
UNUSUALLY LARGE SPREAD BELIEVE A MODEL CONSENSUS IS THE BEST
FORECAST AT THIS POINT. IT LOOKS LIKE THERE WILL BE A SURGE OF COLD
MID-WEEK THAT MAY BE ASSOCIATED WITH WINTRY PRECIP...BUT SINCE THE
EVEN THE LARGE SCALE PATTERN IS DIFFICULT TO PIN DOWN DID NOT SPEND
TOO MUCH TIME WITH WEATHER GRIDS AND SPECIFIC TIMING. SOME SOLUTIONS
INDICATE A DEEP ENOUGH MOISTURE PROFILE TO SUPPORT SOME PERIODS OF
RAIN/SNOW...BUT OTHERS ARE COMPLETELY DRY. THAT SAID...DO HAVE A
LITTLE CONFIDENCE IN TEMPS AS THE COLD WILL BE WIDESPREAD AND LAST
THROUGH THE END OF THE WEEK...BUT TEMPS WILL NOT BE OUT OF THE
ORDINARY...WITH THE COLDEST LOWS OVER THE WEEK IN THE 20S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 521 PM MDT WED OCT 23 2013
VFR CONDITIONS CAN BE EXPECTED FOR THE FIRST PART OF THE TAF
PERIOD...WITH POSSIBLE MVFR IN THE MORNING. BASED ON BUFKIT
SOUNDINGS...MODELS SEEM TO AGREE THAT BOTH TAF SITES WILL HAVE
LOW CEILINGS IN THE MORNING AS LIGHT WINDS...SUBSIDENCE...AND
SATURATED LOW LEVELS WILL BE PRESENT OVER BOTH SITES. NAM GUIDANCE
WENT VERY HEAVY WITH FOG OVER KGLD...BUT HAD NO FOG FOR
KMCK...WHILE OTHER GUIDANCE DID NOT SEEM TO MENTION FOG.
CONSIDERING IF BOTH TAF SITES HAVE LIGHT AND VARIABLE WINDS...WENT
AHEAD AND PUT FOG IN FOR KMCK. ONLY REDUCED VISIBILITY TO 3SM
SINCE THE NAM GUIDANCE SEEMED TO BE A BIT TOO HEAVY ON REDUCING
VISIBILITY. CEILINGS AND VISIBILITY SHOULD RETURN TO VFR MID-LATE
MORNING WITH WINDS STAYING FAIRLY LIGHT OUT OF THE SOUTHEAST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JJM
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS CARIBOU ME
108 AM EDT THU OCT 24 2013
.SYNOPSIS...
A SMALL AREA OF LOW PRESSURE WILL SLIDE WELL SOUTH OF THE REGION
THIS EVENING. AN UPPER LEVEL TROUGH WILL BUILD INTO THE EAST FROM
QUEBEC THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1245 AM: LATEST OBSVD TEMPS WERE USED TO UPDATE FCST HRLY TEMPS TO
UNCHGD FCST LOWS AT 6 AM THU. OTHERWISE...WE DID SOME PRELIM WORK
TO INCREASE POPS ACROSS THE N AND W FOR RN/SN SHWRS FOR THU AFTN
INTO ERLY EVE.
943 PM UPDATE: CLOUDS ASSOCIATED WITH THE DEFORMATION ZONE WITH
LOW PRES WELL SE OF CAPE COD ARE BRUSHING SRN MAINE THIS EVENING.
THE RAIN ASSOCIATED WITH THE LOW WILL MOSTLY REMAIN OFFSHORE...BUT
MAY BRUSH THE ISLANDS AND COASTAL DOWNEAST FROM ABOUT 05-08Z WITH
A BIT OF -RA. THE LAST OF THE -RA WILL SHIFT WELL EAST OF THE AREA
WELL BEFORE DAYBREAK. CLOUDS IN THE NORTH HAVE BEEN BREAKING UP
WITH THE SKY CLEAR TO P/CLDY MOST AREAS FROM ABOUT KMLT NORTH.
MADE SOME TWEAKS TO THE SKY/POP/WX/WIND GRIDS BASED ON THE LATEST
SATELLITE AND RADAR TRENDS. ALSO LOADED THE PAST FEW HOURS OF
OBSERVED DATA AND INTERPOLATED THROUGH THE REMAINDER OF THE NIGHT.
630 PM UPDATE: THE REGIONAL RADARS ARE LOOKING MORE LIKE LATE FALL
THIS EVENING WITH LAKE EFFECT SHOWERS COMING OFF OF LAKES ERIE AND
ONTARIO WITH A BAND OF RAIN CLIPPING CAPE COD AND THE ISLANDS FROM
AN OFFSHORE STORM.
ORGNL DISC: THE MAIN FORECAST CHALLENGE TONIGHT WILL BE HOW
MUCH...IF ANY...PRECIPITATION CLIPS THE DOWNEAST COAST LATE
TONIGHT THROUGH EARLY THU MORNING. DO HAVE SOME CONCERN IN THAT
THE HRRR BRINGS AT LEAST SOME LIGHT RAIN TO THE COAST AND THE SREF
6-HOUR POPS HAVE A 75 PCT CHANCE OF MEASURABLE RAIN ACROSS THE
SOUTHEAST 1/4 OF THE CWA. FOR THIS UPDATE WILL BEEF UP THE POPS TO
LIKELY OVER THE OUTER WATERS AND TO HIGH CHANCE ALONG THE COAST.
IT IS STILL POSSIBLE THAT THE POPS MAY NEED TO BE ADJUSTED UP
FURTHER WITH SUBSEQUENT UPDATE(S) THIS EVENING.
OTHERWISE...THE PAST FEW HOURS OF OBSERVED DATA WAS LOADED WITH
ONLY SOME MINOR TWEAKS TO THE REMAINING FORECAST ELEMENTS TONIGHT.
PREVIOUS DISCUSSION...
A SMALL WAVE OF LOW PRESSURE TRACKING WELL SOUTH OF THE AREA MAY
BRING SOME LIGHT RAIN TO THE DOWNEAST COAST THIS EVENING. THE LOW
WILL QUICKLY MOVE TO THE EAST, SOUTH OF NOVA SCOTIA LATER TONIGHT.
HIGH PRESSURE BUILDING TOWARD THE EAST COAST IN COMBINATION WITH
LOW PRESSURE OVER QUEBEC WILL BRING GUSTY WEST WINDS LATER TONIGHT
INTO THURSDAY. THIS WILL USHER IN SOME VERY CHILLY AIR AS A LARGE
UPPER LEVEL TROUGH MOVES IN. THURSDAY WILL LIKELY BEGIN PARTLY
CLOUDY TO MOSTLY CLEAR AS A WEAK SURFACE RIDGE MOVES OVER.
STRATOCUMULUS CLOUDS WILL THEN INCREASE FROM THE NORTHWEST
THURSDAY AFTERNOON AS MOISTURE IN THE TROUGH BEGINS TO FLOW INTO
THE REGION. SOME SHOWERS OF RAIN AND POSSIBLY WET SNOW IN THE
HIGHER ELEVATIONS MAY AFFECT NORTHERN AND WESTERN AREAS LATE IN
THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
A TROF WILL CROSS THE REGION THURSDAY NIGHT...WITH ANOTHER TROF
CROSSING THE REGION FRIDAY. MOSTLY CLOUDY SKIES ALONG WITH A
SLIGHT CHANCE OF RAIN/SNOW SHOWERS ARE EXPECTED ACROSS THE NORTH
AND MOUNTAINS THURSDAY NIGHT AND FRIDAY...WITH GENERALLY PARTLY
CLOUDY SKIES DOWNEAST. HIGH PRESSURE WILL THEN BUILD EAST FRIDAY
NIGHT WITH PARTLY CLOUDY SKIES NORTH AND PARTLY CLOUDY/MOSTLY
CLEAR SKIES DOWNEAST. TEMPERATURES WILL BE AT NEAR NORMAL...TO
SLIGHTLY BELOW NORMAL...LEVELS THURSDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE WILL CROSS THE REGION SATURDAY WHILE LOW PRESSURE
TRACKING NORTHEAST FROM THE GREAT LAKES DRAWS A COLD/OCCLUDED
FRONT TOWARD THE REGION. CLOUD COVER WILL INCREASE ACROSS THE
REGION LATER SATURDAY IN ADVANCE OF THE COLD/OCCLUDED FRONT. THE
COLD/OCCLUDED FRONT WILL THEN CROSS THE REGION SATURDAY NIGHT
THROUGH SUNDAY. FORECAST SOUNDINGS INDICATE THAT TEMPERATURES
ALOFT WOULD SUPPORT SNOW ACROSS MUCH OF THE FORECAST AREA SATURDAY
NIGHT. HOWEVER...BOUNDARY LAYER TEMPERATURES WILL REMAIN MARGINAL
FOR SNOW ACROSS MOSTLY NORTHERN/CENTRAL PORTIONS OF THE FORECAST
AREA. EXPECT A RAIN/SNOW MIX COULD TRANSITION TO MOSTLY SNOW
ACROSS NORTHERN PORTIONS OF THE FORECAST AREA SATURDAY
NIGHT...WITH A RAIN/SNOW MIX ACROSS CENTRAL AREAS AND MOSTLY RAIN
DOWNEAST. COULD HAVE LIGHT SNOW ACCUMULATIONS ACROSS NORTHERN
AREAS LATER SATURDAY NIGHT PARTICULARLY ACROSS HIGHER TERRAIN
AREAS. THE COLD/OCCLUDED FRONT WILL MOVE EAST EARLY SUNDAY WITH
STEADIER PRECIPITATION ENDING. COULD THEN HAVE LINGERING RAIN
SHOWERS ACROSS MOSTLY NORTHERN AREAS SUNDAY AFTERNOON...WITH A
SLIGHT CHANCE OF RAIN/SNOW SHOWERS SUNDAY NIGHT. A COLD FRONT THEN
CROSSES THE REGION MONDAY WITH A CHANCE OF RAIN/SNOW SHOWERS
ACROSS MOSTLY THE NORTH/MOUNTAINS. HIGH PRESSURE WILL THEN CROSS
THE REGION TUESDAY. UNCERTAINTY EXISTS TUESDAY NIGHT INTO
WEDNESDAY REGARDING WHETHER A POSSIBLE COLD FRONT CROSSES THE
REGION WITH A CHANCE OF SHOWERS OR WHETHER HIGH PRESSURE PERSISTS.
TEMPERATURES WILL REMAIN AT NEAR NORMAL...TO SLIGHTLY BELOW
NORMAL...LEVELS SATURDAY THROUGH WEDNESDAY.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE AREA TONIGHT AND
THURSDAY. THERE IS THE POTENTIAL THAT THERE COULD BE A SHORT
WINDOW OF MVFR CEILINGS AT KBHB OVERNIGHT IF THE AREA OF RAIN
OFFSHORE MOVES INTO THE AREA...BUT ODDS FAVOR CONDITIONS REMAINING
VFR. THE WIND WILL BECOME GUSTY THURSDAY AS COOLER AIR MOVES IN.
SHORT TERM: OCCASIONAL MVFR CONDITIONS ARE POSSIBLE ACROSS MOSTLY
THE NORTH AND MOUNTAINS THURSDAY NIGHT INTO FRIDAY...WITH VFR
CONDITIONS DOWNEAST. VFR CONDITIONS ARE EXPECTED ACROSS THE REGION
FRIDAY NIGHT INTO SATURDAY. MVFR/IFR CONDITIONS ARE THEN EXPECTED
ACROSS THE REGION SATURDAY NIGHT INTO EARLY SUNDAY. OCCASIONAL
MVFR CONDITIONS WILL LINGER ACROSS THE NORTH AND MOUNTAINS SUNDAY
NIGHT INTO MONDAY...WITH GENERALLY VFR CONDITIONS DOWNEAST.
&&
.MARINE...
NEAR TERM: A GALE WARNING IS IN EFFECT FOR THE OFFSHORE WATERS
FOR WEST WINDS GUSTING UP TO 35 KT THURSDAY AFTERNOON INTO
THURSDAY EVENING. A SCA IS IN EFFECT FOR THE INTRACOASTAL WATERS
THURSDAY AFTERNOON AND EVENING.
SHORT TERM: A GALE WARNING WILL REMAIN IN EFFECT FOR MUCH OF THE
WATERS EARLY THURSDAY NIGHT. GENERALLY SMALL CRAFT CONDITIONS ARE
THEN EXPECTED ACROSS THE WATERS LATER THURSDAY NIGHT INTO MONDAY.
VISIBILITIES COULD BE REDUCED IN RAIN SATURDAY NIGHT INTO SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO MIDNIGHT EDT TONIGHT
FOR ANZ052.
GALE WARNING FROM NOON TODAY TO MIDNIGHT EDT TONIGHT FOR
ANZ050-051.
&&
$$
NEAR TERM...VJN
SHORT TERM...NORCROSS
LONG TERM...NORCROSS
AVIATION...VJN/NORCROSS
MARINE...VJN/NORCROSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
144 AM EDT THU OCT 24 2013
.SYNOPSIS...
COOLER AIR IS ON THE WAY AS ANOTHER COLD FRONT APPROACHES THE REGION
AND PUSHES OFF THE COAST FRIDAY MORNING. BELOW NORMAL TEMPERATURES
ARE EXPECTED THROUGH THE WEEKEND...AND THE FIRST FROST OR FREEZE OF
THE SEASON COULD OCCUR FRIDAY NIGHT INTO EARLY SATURDAY MORNING. A
SLOW WARMING TREND WILL BEGIN SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:45 AM THURSDAY...CLEAR AND COLD EARLY THIS MORNING WHICH
IS EXACTLY AS EXPECTED. LATEST OBS SHOW MID TO UPPER 40S MOST
PLACES...EVEN CLOSE TO THE COAST. NO CHANGES ANTICIPATED TO THE
NEAR TERM FORECAST. PREVIOUS DISCUSSION FOLLOWS:
A BROAD UPPER TROUGH COVERS THE EASTERN HALF OF THE NATION THIS
EVENING. THE COOLEST AIRMASS OF THIS FALL SEASON IS SPREADING DOWN
TO THE EAST COAST BEACHES...AND WELL- BELOW NORMAL TEMPERATURES
SHOULD CONTINUE INTO SATURDAY. AT THE SURFACE HIGH PRESSURE IS
CENTERED OVER THE WESTERN DAKOTAS BUT EXTENDS A RIDGE AXIS INTO
THE MID-SOUTH REGION.
850 MB TEMPERATURES ARE FALLING RAPIDLY AND SHOULD END UP BETWEEN
+3C AND +7C ACROSS THE AREA BY DAYBREAK THURSDAY. AS THE COLDER AIR
BUILDS IN THERE IS A REGION OF TIGHTENED PRESSURE GRADIENT
DISCERNIBLE ON SURFACE MAPS ACROSS THE INTERIOR COASTAL PLAIN AND
EASTERN PIEDMONT REGION. THIS SHOULD SHIFT TO THE COAST OVER THE
NEXT FEW HOURS THEN OFFSHORE...BRINGING A BRIEF (2-3 HOUR) PERIOD
OF GUSTY WINDS FOLLOWING BY QUICKLY FALLING TEMPERATURES. ALMOST
ALL MODELS SHOW THIS...AND THE LATEST FEW HRRR RUNS SHOW
ANTICIPATED TRENDS WITH WINDS AND TEMPERATURES QUITE WELL.
NO SIGNIFICANT CHANGES HAVE BEEN MADE TO FORECAST LOWS...STILL
EXPECTED TO RANGE FROM THE LOWER 40S ALONG THE COAST TO THE UPPER
30S INLAND. EVEN THOUGH INLAND WINDS SHOULD BECOME RATHER LIGHT (5
MPH OR LESS) LATE...THERE SHOULD BE INSUFFICIENT HUMIDITY TO
PRODUCE FROST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...EARLY ON IN THE SHORT TERM PERIOD A
CONFLUENT H5 PATTERN WILL EXIST ACROSS THE NATION/S MID-SECTION
WITH TROFFING ACROSS THE GREAT LAKES INTO NEW ENGLAND. THE
VORTICITY IN THIS SCENARIO IS HIGHLY CHANNELED...NEVERTHELESS THIS
SETUP WILL LEAD TO ANOTHER REINFORCEMENT OF COOLER/DRIER AIR INTO
THE CAROLINAS BY FRIDAY. TIME HEIGHT CROSS SECTIONS INDICATE A DRY
COLUMN WILL PREVAIL...THE EXCEPTION IS A BRIEF PERIOD OF
INCREASING LOW-LEVEL MOISTURE THURSDAY NIGHT INTO FRIDAY MORNING.
THIS INCREASE IN MOISTURE IS LIKELY IN RESPONSE TO BACKING LOW-
LEVEL WINDS JUST AHEAD OF THE NEXT FRONT/SURGE. BY FRIDAY
AFTERNOON EXPECT CLEAR SKIES...AND A DECOUPLED WIND FIELD BY
FRIDAY EVENING WHICH WILL SET THE STAGE FOR OPTIMAL RADIATIONAL
COOLING. THE TYPICAL COOL SPOTS WILL LIKELY DROP TO AT OR BELOW
FREEZING DURING THIS TIME FRAME...WITH MID 30S EXPECTED MOST OTHER
LOCATIONS (UPPER 30S TO AROUND 40 AT THE COAST). THESE ARE THE
COOLEST TEMPERATURES THUS FAR THIS FALL...AND FROST IS ALSO A
POSSIBILITY...ESPECIALLY AWAY FROM THE WARMER COAST. OVERALL
DURING FRIDAY NIGHT THE MIN TEMPERATURES WILL BE WELL BELOW
CLIMATOLOGY...WHICH ARE UPPER 40S THIS TIME OF YEAR.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...LOW LEVEL THERMAL TROUGH/COLD AIR TONGUE
CROSSES THE REGION ON SATURDAY...850MB TEMPS GENERALLY ABOUT 2-3C TO
START THE DAY. WARM AIR ADVECTION THROUGH THE AFTERNOON WARMS THE
LAYER TO 6-7C. AT THE SURFACE HOWEVER HIGH PRESSURE HANGS ON LONG
ENOUGH TO KEEP WINDS LIGHT AND VARIABLE ENOUGH TO KEEP THESE TEMPS
FROM MIXING TO THE SURFACE AND ANOTHER VERY CHILLY DAY EXPECTED. THE
OVERALL HIGHER THETA AIR WILL BE REALIZED AT THE SURFACE SATURDAY
NIGHT THOUGH AS LOWS SHOULD BE CLOSE TO 40...NOT AS CHILLY AS THE
PRIOR TWO BUT STILL A GOOD 10-15 BELOW CLIMO. A LIGHT SOUTH WIND
DEVELOPS ON SUNDAY AND THERE SHOULD BE DEEPER MIXING ALLOWING FOR
HIGHS MUCH CLOSER TO BUT STILL A LITTLE SHY OF NORMAL. A DISSIPATING
BACKDOOR COLD FRONT WILL SLIP THROUGH LATE SUNDAY WITH FAR TOO
LITTLE MOISTURE TO WORK WITH TO CAUSE MUCH MORE THAN JUST A WIND
SHIFT. FOR THE REMAINDER OF THE PERIOD MID LEVEL FLOW WILL BE NEARLY
ZONAL AND QUITE WEAK AS THE LARGE TROUGHINESS OVER EASTERN CANADA
WEAKENS CONSIDERABLY AND SOME INCREASING AMPLITUDE TAKES SHAPE OUT
WEST...KEEPING OUT WEATHER DRY AND SEASONABLE.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THE FORECAST
PERIOD. CLEAR SKIES OVERNIGHT WITH A RADIATIONAL INVERSION. WINDS
MAY NOT GO COMPLETELY CALM AS THERE WILL BE A LOW LEVEL JET MOVING
THROUGH OVERNIGHT THAT WILL KEEP WINDS AT 5-10KTS. THERE WILL ALSO
BE SOME RENEWED COLD AIR ADVECTION THAT MAY MIX THINGS A BIT.
THURSDAY...LIGHT NORTHWEST FLOW WITH SCATTERED SKIES. A SOUTHWEST
GRADIENT IS POSSIBLE IN THE AFTERNOON WITH A WEAK SURFACE LOW.
EXTENDED OUTLOOK...VFR WILL PREVAIL THROUGH THE EXTENDED PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:45 AM THURSDAY...WINDS AND SEAS HAVE FALLEN BACK BELOW
ADVISORY CRITERIA...SO WILL ALLOW SCA TO EXPIRE ON TIME AT 2 AM.
LATEST OBS SHOW 2 TO 4 FT SEAS WITH NW WINDS IN THE 15 TO 20 KT
RANGE WITHIN 20 NM. PREVIOUS DISCUSSION FOLLOWS:
HIGH PRESSURE CENTERED IN THE WESTERN DAKOTAS EXTENDS A RIDGE AXIS
INTO THE MID-SOUTH REGION...WHILE LOW PRESSURE WELL OFF THE NEW
ENGLAND COAST PUSHES FARTHER OFFSHORE. A REGION OF STRONG WINDS
(25-35 KNOTS) 1000-2000 FEET ABOVE GROUND LEVEL CURRENTLY EXISTS
ACROSS THE EASTERN CAROLINAS...AND SHOULD PUSH OFFSHORE IN THE
NEXT HOUR. SINCE MARINE AIR TEMPERATURES ARE A GOOD 10 DEGREES
WARMER THAN INLAND TEMPERATURES...I ANTICIPATE THESE STRONGER
WINDS TO BE MIXED DOWN TO THE OCEAN SURFACE WITH SUSTAINED WINDS
SOON INCREASING TO 20-25 KNOTS WITH GUSTS NEAR 30 KNOTS.
THE LATEST SEVERAL RUNS OF THE HRRR AND RUC MODELS DEPICT THIS
SURGE OF NORTHWEST WINDS QUITE WELL...AND ARE THE BASIS FOR THIS
UPDATE. I HAVE EXPANDED THE SMALL CRAFT ADVISORY SOUTHWARD TO
INCLUDE ALL OF MY SOUTH CAROLINA WATERS...AND HAVE EXTENDED THE
ENDING TIME OF THE ADVISORY TO 2 A.M. AFTER 2 A.M. WIND SPEEDS
WILL DIMINISH AS WIND DIRECTIONS VEER MORE NORTHERLY. NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO WAVE HEIGHT FORECASTS WHICH
STILL RANGE FROM 2-4 FT ALONG MOST OF THE COAST...EXCEPT FOR AN
AREA OF 5-FOOTERS AWAY FROM SHORE NEAR CAPE FEAR.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...SURGE OF COOL AIR WILL WANE THURSDAY
MORNING AS A SURFACE RIDGE AXIS BUILDS ACROSS THE COASTAL WATERS.
THE RESULT WILL BE A DECREASE IN THE OFFSHORE FLOW BY THE AFTERNOON.
THE NEXT REINFORCING SHOT OF COOL AIR WILL ARRIVE FRIDAY MORNING
ALLOWING THE WINDS TO VEER AROUND TO A NORTHERLY DIRECTION AND
INCREASE AGAIN IN THE WAKE OF THE FRONT. THE OFFSHORE FLOW WILL
CREATE A FETCH LIMITATION IN THE LOCAL WAVE GROWTH THUS A RANGE OF
SEAS WILL EXIST THROUGH MUCH OF THE SHORT TERM PERIOD.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE BUILDS IN ON SATURDAY
BRINGING A MUCH DECREASING WIND AND POSSIBLY SOME LATE DAY
VARIABILITY IN THE OTHERWISE NORTHERLY FLOW. THE CENTER OF THE HIGH
SHIFTS WESTWARD AS IT WEAKENS SATURDAY NIGHT INTO SUNDAY LEADING TO
A BIT OF A BACKING. THIS WILL THEN BE FOLLOWED BY A DISSIPATING
BACKDOOR COLD FRONT COMING THROUGH FROM THE NORTH SUNDAY NIGHT.
NORTHERLY FLOW RETURNS BEHIND THIS BOUNDARY AS ANOTHER LARGE HIGH
STARTS TO BUILD IN FROM THE NORTH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT EARLY THIS MORNING FOR
AMZ250-252-254-256.
&&
$$
NEAR TERM...REK/TRA
MARINE...REK/TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
135 AM EDT THU OCT 24 2013
.SYNOPSIS...
COLD AIR WILL CONTINUE TO FILTER INTO THE REGION ON NORTHWEST WINDS.
FLOW OFF THE GREAT LAKES AND A SECONDARY COLD FRONT WILL BRING PERIODS
OF RAIN AND SNOW SHOWERS TONIGHT INTO THURSDAY. HIGH PRESSURE OF
CANADIAN ORIGIN WILL BUILD INTO THE REGION PROVIDING ANOTHER ROUND
OF SUB-FREEZING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SHOWER ACTIVITY HAS DIMINISHED TO ALL BUT A COUPLE VERY LIGHT
RETURNS IN THE FAR NORTH. REGIONAL RADAR MOSAIC STILL SHOWS
SCATTERED LAKE EFFECT ACTIVITY STREAMING OFF SOUTHEASTERN LAKE
MICHIGAN. LATEST HI-RES MODEL GUIDANCE GENERALLY DOES NOT SUPPORT
THIS ACTIVITY MAKING ITS WAY INTO OHIO...BUT OPTED TO MAINTAIN A
SLIGHT CHANCE OF SHOWERS /RAIN CHANGING TO SNOW/ ACROSS THE FAR
NORTHERN CWA TONIGHT. OTHER MAIN CONCERN TONIGHT IS CLOUD COVER
AND ITS EFFECTS ON LOW TEMPERATURES AND THE FREEZE WARNING.
EARLIER THIS EVENING CLOUDS HAD SCATTERED OUT NICELY ACROSS MUCH
OF THE AREA WHICH ALLOWED TEMPS TO QUICKLY DROP INTO THE MID 30S
IN THE CLEAR SLOTS. CURRENT SATELLITE IMAGERY SHOWS A MID LEVEL
CLOUD DECK STREAMING IN FROM INDIANA AND TEMPS HAVE JUMPED UP A
DEGREE OR TWO WHERE THESE CLOUDS HAVE MOVED IN. THE 00Z NAM AND
01Z RAP SEEM TO HAVE A GOOD HANDLE ON CURRENT CLOUD COVER AND
WOULD SEEM TO SUGGEST PARTLY TO MOSTLY CLOUDY SKIES TONIGHT. WILL
HAVE TO MONITOR TRENDS OVERNIGHT BUT FEEL THAT CURRENT WEAK COLD
ADVECTION REGIME MAY STILL ALLOW TEMPERATURES TO DROP INTO THE
LOWER 30S IN MOST LOCATIONS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
A DEEP MEAN TROF OVER THE EASTERN CONUS WILL CONTINUE TO INFLUENCE
OUR WEATHER. NORTHWEST FLOW WILL CONTINUE...AND ADDITIONAL SHOWERS
WILL BE POSSIBLE THURSDAY OFF THE GREAT LAKES. ALSO...A S/W
PASSING THRU THE MEAN TROF MAY LEAD TO SHOWERS ACRS THE SRN ZONES.
CONSIDERABLE CLOUDINESS CAN BE EXPECTED WITH TEMPERATURES CLOSE TO
20 DEGREES BELOW NORMAL. HIGHS ON THURSDAY ARE EXPECTED TO BE
RANGE FROM THE LOWER 40S NORTH TO THE MID/UPR 40S SOUTH.
THE UPPER LEVEL TROF WILL BEGIN TO SHIFT EAST...AS SFC HIGH
PRESSURE BUILDS EASTWARD TOWARD OUR AREA. THIS HIGH SHOULD ALLOW
SOME CLEARING THURSDAY NIGHT...WHILE WINDS BECOME VERY LIGHT. THIS
WOULD ALLOW TEMPERATURES TO DROP INTO THE UPPER 20S...WITH A HARD
FREEZE LIKELY ACRS ALL COUNTIES.
THE SFC HIGH WILL BUILD SE BECOMING CENTERED OVER TN ON FRIDAY...
PROVIDING MOSTLY SUNNY TO PARTLY CLOUDY SKY CONDITIONS. AFTER A
COLD START TO THE DAY...HIGHS ARE EXPECTED TO ONLY REACH THE UPPER
40S.
THE COLD HIGH WILL CONTINUE TO INFLUENCE OUR WEATHER WITH SKIES
BECOMING MOSTLY CLEAR FRIDAY NIGHT. LOWS ARE EXPECTED TO BE IN THE
UPPER 20S TO LOWER 30S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
FOR SATURDAY...HIGH PRESSURE WILL BE MOVING EAST AS A COLD FRONT
CROSSES THE GREAT LAKES. THIS SCENARIO WILL MEAN INCREASING CLOUDS
AND WINDS BUT PROBABLY NO PRECIPITATION. HIGH PRESSURE AND PARTLY
CLOUDY SKIES WILL RETURN ON SUNDAY. THE HIGH WILL MAINTAIN DRY
WEATHER ON MONDAY EVEN AS ANOTHER COLD FRONT MOVES THROUGH THE
EASTERN GREAT LAKES.
WEATHER WILL CHANGE STARTING TUESDAY. A SLOW MOVING FRONTAL BOUNDARY
WILL FORM TO THE WEST AND THEN PROPAGATE INTO THE ILN AREA. THIS
WILL BRING THE LIKELIHOOD FOR SHOWERS BY TUESDAY NIGHT...WITH THE
CHANCE OF SHOWERS CONTINUING THROUGH WEDNESDAY AS THE FRONT MEANDERS
OVER THE REGION.
THE TREND OF BELOW NORMAL TEMPERATURES WILL PERSIST ON SATURDAY AND
SUNDAY WITH HIGHS FORECAST TO BE IN THE LOW TO MID 50S. READINGS MAY
RISE CLOSE TO NORMAL INTO THE LOW 60S BY TUESDAY AS WARM ADVECTION
OCCURS NEAR THE FRONT.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
LIGHT SHOWERS NEAR THE OHIO RIVER WILL SHIFT AWAY FROM THE TAF
SITES BY 07Z. SOME BRIEF MVFR CIGS WILL BE POSSIBLE THROUGH THAT
TIME...MAINLY AT KLUK. OTHERWISE...VFR DECK AROUND 5 TO 8 KFT IS
EXPECTED ACROSS THE AREA THROUGH 15Z. A WEAK DISTURBANCE
MOVING WEST TO EAST ACROSS THE OHIO RIVER MIDDAY WILL BRING
INCREASING CHANCES FOR MVFR CIGS AND SCATTERED SHOWERS TO THE
MAJORITY OF THE TAF SITES. KCMH/KLCK MAY BE FAR ENOUGH NORTH TO
KEEP VFR CIGS AND AVOID SHOWER ACTIVITY FROM THIS
DISTURBANCE. ADDITIONAL SHOWERS ARE POSSIBLE OFF THE GREAT
LAKES...BUT SHOULD STAY NORTH OF KCMH/KLCK. CIGS ARE EXPECTED TO
IMPROVE TO VFR BEHIND THE DISTURBANCE DURING THE EVENING. SKIES
MAY STAY MOSTLY CLOUDY WELL INTO THE LATE EVENING AS A LARGE
AMOUNT OF LOW LEVEL MOISTURE REMAINS IN PLACE.
OUTLOOK...MVFR CIGS POSSIBLE SATURDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR OHZ026-034-035-
042>046-051>056-060>065-070>074-077>082-088.
KY...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR KYZ089>100.
IN...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR INZ050-058-059-
066-073>075-080.
&&
$$
SYNOPSIS...AR
NEAR TERM...KURZ
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...LATTO
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1154 PM CDT WED OCT 23 2013
.AVIATION UPDATE...FOR 06Z TAF PACKAGE...
IR SATELLITE CONTINUES TO INDICATE ONSET OF HIGH CEILINGS AT KCKV
AND KBNA. KCSV WILL BE SEEING THE CLOUD COVER IN FIRST COUPLE
HOURS OF TAF PERIOD. CEILINGS WILL DECREASE OVER NEXT 6 HOURS BUT
SHOULD STAY ABOVE MVFR HEIGHTS. VFR EXPECTED TO PREVAIL THROUGHOUT.
&&
.PREV DISCUSSION... /ISSUED 855 PM CDT WED OCT 23 2013/
UPDATE...
SEVERAL ISSUES WITH FORECAST FOR TONIGHT INCLUDING
TEMPERATURES...SKY COVER...FREEZE WARNING ON THE PLATEAU...AND
EVEN PRECIPITATION. TEMPERATURES HAVE DROPPED RAPIDLY THIS
EVENING WITH MUCH OF THE CWA EAST OF I-65 OUTSIDE OF THE URBAN
NASHVILLE METRO ALREADY IN THE MID 30S PER SURFACE OBS.
HOWEVER...SATELLITE IMAGERY SHOWS THICK MID/HIGH LEVEL CLOUD COVER
NOW ENTERING THE CWA AND SPREADING QUICKLY SOUTHEASTWARD...AND
ONCE CLOUDS COVER A PARTICULAR LOCATION TEMPERATURES SHOULD REMAIN
NEARLY STEADY REMAINDER OF THE NIGHT. BASED ON THIS
REASONING...WILL NOT EXPAND THE FREEZE WARNING WESTWARD TO INCLUDE
MORE COUNTIES ALTHOUGH WAS TEMPTED TO DO SO...BUT DID BUMP UP
TIMING OF FREEZE WARNING START TO 06Z. ALSO ADJUSTED SKY COVER AND
OTHER GRIDS BASED ON LATEST OBS AND TRENDS. RADAR IMAGERY ALSO
SHOWING SOME LIGHT RAIN ACROSS SOUTHERN ILLINOIS SPREADING ACROSS
CENTRAL KENTUCKY AT THIS HOUR. HRRR AND WRF MODELS INDICATE THIS
PRECIP SHOULD REMAIN NORTH OF THE CWA TONIGHT...BUT A STRAY
FLURRY IS NOT COMPLETELY OUT OF THE QUESTION ON THE NORTHERN
PLATEAU. CHANCE IS TOO REMOTE TO MENTION IN THE FORECAST.
ALTHOUGH HAVE NOT HAD MUCH OF A CHANCE TO LOOK AT TEMPERATURES
THE NEXT TWO NIGHTS...LATEST MAV/MET MOS STILL INDICATE POTENTIAL
FOR WIDESPREAD FREEZING TEMPERATURES FOR NEARLY ALL OF MIDDLE
TENNESSEE BOTH THURSDAY AND FRIDAY NIGHTS. TIME HEIGHT
MOISTURE/OMEGA FIELDS SHOW THAT CLOUDS SHOULD NOT BE A FACTOR IN
TEMPS THURSDAY NIGHT...BUT CIRRUS COULD BE A FACTOR ON FRIDAY
NIGHT. NO CHANGES WERE MADE TO INHERITED FREEZE WATCH FOR
THURSDAY NIGHT.
SHAMBURGER
PREV DISCUSSION... /ISSUED 635 PM CDT WED OCT 23 2013/
AVIATION UPDATE...FOR 00Z TAF PACKAGE...
IR SATELLITE TRENDS CONTINUE TO INDICATE BKN DECK OF 10KFT
CEILINGS ON THE APPROACH FROM THE NW. BELIEVE THIS WILL PREVAIL
THROUGH FIRST 12 HOURS OF TAF PERIOD FOR KCKV AND KBNA. CEILINGS
SHOULD DROP BY MID MORNING AS MOISTURE CONTINUES TO MOVE IN AND
MOISTEN THE COLUMN. COULD BE NEAR MVFR CEILINGS BY AROUND 14Z BUT
KEPT OFFICIAL FORECAST JUST ABOVE FOR NOW.
PREV DISCUSSION... /ISSUED 238 PM CDT WED OCT 23 2013/
DISCUSSION...HIGH PRESSURE NOW BUILDING INTO MIDDLE TENNESSEE
FROM THE WEST, WITH A SCT-BKN CU FIELD COVERING THE NE HALF OF
MIDDLE TENNESSEE THIS AFTERNOON. DESPITE A STRONG NW BREEZE MOST
OF THE DAY, SURFACE PRESSURE GRADIENT IS STARTING TO BREAK DOWN
NOW, SO WINDS HAVE BEGUN TO DIMINISH. EXPECT MOST OF MIDDLE
TENNESSEE TO REMAIN PARTLY TO MOSTLY CLOUDY OVERNIGHT AND THURSDAY
AHEAD OF THE 850 MB TROUGH. DESPITE THIS, TEMPERATURES ALONG THE
CUMBERLAND PLATEAU WILL DROP TO OR BELOW FREEZING TONIGHT, HENCE
THE EARLIER FREEZE WARNING. THE HIGH CENTER WILL GRADUALLY WORK
ITS WAY EASTWARD AS THE MID STATE REMAINS UNDER A COLD AIR MASS.
WITH THE COLD ADVECTION PATTERN EXPECTED TO LAST INTO THE WEEKEND,
FREEZING OVERNIGHT TEMPERATURES WILL BECOME MORE PREVALENT
TOMORROW AND FRIDAY NIGHT, WITH RETURN FLOW PICKING UP ON SATURDAY
AND BRINGING WARMER AIR. HIGHS ON TUESDAY AND WEDNESDAY OF NEXT
WEEK WILL LIKELY HIT THE LOWERS 70`S AHEAD OF THE NEXT BIG SYSTEM,
WHICH THE ECMWF BRINGS THROUGH ON THURSDAY AND THE GFS ON FRIDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY MORNING FOR
TNZ005>011-022>034-056>066-075-077>080-093>095.
FREEZE WARNING UNTIL 9 AM CDT THURSDAY FOR TNZ011-032>034-065-
066-078>080.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS GOODLAND KS
527 AM MDT THU OCT 24 2013
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 229 AM MDT THU OCT 24 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS NW FLOW STILL IN PLACE
ACROSS NORTHERN AND CENTRAL PLAINS WITH CONFLUENT FLOW OVER THE
CENTRAL ROCKIES. AT THE SURFACE A COLD FRONT HAS STALLED ALONG THE
FRONT RANGE...EXTENDING SOUTH ACROSS THE TEXAS PANHANDLE.
IN THE NEAR TERM...DESPITE LITTLE IN THE WAY OF DEVELOPMENT SO FAR
EARLY THIS MORNING PATCHY FOG/STRATUS STILL SEEMS REASONABLE OVER
WESTERN LOCATIONS WITH TEMPS BEGINNING TO COOL TO WITH A FEW
DECREES OF TD VALUES. NAM/RAP/HRRR STILL SHOW BL MOISTURE
APPROACHING SATURATION IN THE WEST...WITH SOME VISIBILITY
RESTRICTIONS ADVERTISED BY MET GUIDANCE AND NAM. NOT REALLY
CONFIDENT IN COVERAGE...SO I PLAN ON LEAVING ONGOING FORECAST IN
PLACE.
WITH STORM TRACKS WELL NORTH AND SOUTH OF OUR CWA...AND
DRY AIR MASS (BELOW 700MB) IN PLACE OVER OUR CWA THROUGH SATURDAY
NIGHT I EXPECT DRY CONDITIONS TO CONTINUE. TEMPS TODAY WILL BE
ABOUT 10-15F COOLER THAN YESTERDAY (VALUES IN THE 50S)...WITH
COOLER POST FRONTAL AIR MASS IN PLACE. AS A SHORTWAVE TROUGH
PASSES OVER THE NORTHERN PLAINS FRIDAY AND CLOSED LOW OVER
SOUTHERN PLAINS (BOTH OUTSIDE OF OUR AREA OF CONCERN...WE WILL
BEGINNING OT SEE A SHIFT IN THE UPPER PATTERN ALLOWING FOR A
STRENGTHENING OF THE LEE TROUGH AND LIFTING OF A WARM FRONT OVER
OUR CWA. IN RESPONSE BREEZY/MILD CONDITIONS ARE EXPECTED
FRIDAY...WITH ONLY MID-HIGH CLOUDS IN OUR SOUTH. A COLD FRONT WILL
THEN DROP SOUTH BY SATURDAY MORNING WITH A BREEZY NW WIND DURING
THE MORNING HOURS. TEMPS MAY BE A LITTLE COOLER...HOWEVER THERE IS
NOT A LARGE DROP IN TEMPS ALOFT BEHIND THIS FROPA SO WE WILL
LIKELY STAY NEAR SEASONAL VALUES (60S).
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 229 AM MDT THU OCT 24 2013
SUMMARY...DRY AND MILD TO START NEXT WEEK BEFORE BECOMING COLDER
WITH A CHANCE OF WINTRY PRECIP BY MID-WEEK.
SUNDAY...FORECAST HAS BEEN LOOKING LIKE A LOCK FOR THE PAST FEW DAYS
WITH HIGHS IN THE LOW 70S UNDER THE INFLUENCE OF SOME MINOR RIDGING
AND WARM AIR ADVECTION.
MONDAY...A TRANSITIONAL DAY...PROBABLY. GUIDANCE HAS BEEN VERY
INCONSISTENT WITH THE MON-TUES-WED PERIOD FOR THE PAST FEW
DAYS...AND THE 00Z SUITE IS NOT ANY BETTER THAN EARLIER CYCLES.
GEM/ECMWF DEPICT THE COLD FRONT PUSHING SOUTH MONDAY INTO EARLY
TUESDAY...WHILE THE GFS DELAYS THE ARRIVAL UNTIL LATE TUESDAY.
BECAUSE OF THIS THE GFS DEPICTS A MILDER MONDAY WHILE OTHER GUIDANCE
INDICATES INCREASING CLOUDINESS AND ARRIVAL OF THE COLD LIMITING
HIGH TEMPS. THE GEFS MEMBERS SHOW A LARGE SPREAD...INCLUDING
DEPICTING SOLUTIONS MORE IN LINE WITH OTHER GUIDANCE. ULTIMATELY AM
THINKING IT WILL TURN OUT SOMEWHERE IN THE MIDDLE WITH WEAK WAA IN
EASTERN PARTS OF THE CWA AND INCREASING CLOUDS IN THE WEST.
TUESDAY AND WEDNESDAY...VERY LITTLE CONFIDENCE WHATSOEVER FOR THE
REST OF THE WEEK. GEFS/ECMWF ENS ARE ALL OVER THE PLACE...AND AS WPC
POINTS OUT BY TUES THE SYNOPTIC SOLUTIONS ARE MORE THAN 1000 MILES
APART AND THE SPREAD ONLY GROWS FROM THERE. BECAUSE OF THIS
UNUSUALLY LARGE SPREAD BELIEVE A MODEL CONSENSUS IS THE BEST
FORECAST AT THIS POINT. IT LOOKS LIKE THERE WILL BE A SURGE OF COLD
MID-WEEK THAT MAY BE ASSOCIATED WITH WINTRY PRECIP...BUT SINCE THE
EVEN THE LARGE SCALE PATTERN IS DIFFICULT TO PIN DOWN DID NOT SPEND
TOO MUCH TIME WITH WEATHER GRIDS AND SPECIFIC TIMING. SOME SOLUTIONS
INDICATE A DEEP ENOUGH MOISTURE PROFILE TO SUPPORT SOME PERIODS OF
RAIN/SNOW...BUT OTHERS ARE COMPLETELY DRY. THAT SAID...DO HAVE A
LITTLE CONFIDENCE IN TEMPS AS THE COLD WILL BE WIDESPREAD AND LAST
THROUGH THE END OF THE WEEK...BUT TEMPS WILL NOT BE OUT OF THE
ORDINARY...WITH THE COLDEST LOWS OVER THE WEEK IN THE 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 527 AM MDT THU OCT 24 2013
STRATUS HAS DEVELOPED OVER CENTRAL NEBRASKA OVERNIGHT WITH CIGS
3-3.5KFT REPORTED EARLY THIS MORNING. COULDNT RULE OUT CIGS
DROPPING TO MVFR CIGS AT KMCK BEFORE 15KT...SO INCLUDED TEMPO
GROUP. ITS HARD TO SAY HOW WIDESPREAD VIS RESTRICTIONS WITH FOG
WILL BE AT KGLD...WITH GUIDANCE NOT SHOWING MUCH AT THIS POINT.
STILL LOOKS LIKE A GOOD SET UP FOR FOG DEVELOPMENT ACROSS EASTERN
COLORADO AND WESTERN KANSAS. VIS ALREADY DROPPING TO AROUND 5-6SM
AT KGLD...SO WILL INTRODUCE MVFR GROUP AND MONITOR. WINDS SHOULD
REMAIN 12KT OR LESS OUT OF THE SOUTHEAST AT BOTH SITES
TODAY...WITH WINDS SHIFTING TO THE SOUTH-SOUTHWEST AFTER 09Z AT
KGLD AS LEE TROUGH BUILDS IN EASTERN COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JJM
AVIATION...DR
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1105 AM EDT THU OCT 24 2013
.UPDATE...
ISSUED AT 1105 AM EDT THU OCT 24 2013
14Z SFC ANALYSIS SHOWS CYCLONIC FLOW OVER EAST KENTUCKY CONNECTED TO
A BROAD AREA OF LOW PRESSURE OFF TO THE NORTHEAST. THIS LOW CONTINUES
TO SEND COLD AIR INTO THE REGION...ALONG WITH PLENTY OF LOW AND MID
LEVEL CLOUDS. AS A RESULT...DO NOT ANTICIPATE MUCH OF A DIURNAL RISE
TODAY...GENERALLY LESS THAN 10 DEGREES. IN ADDITION...THERE IS SOME
VERY LIGHT PCPN FALLING...FROM THE CLOUDS BLANKETING EAST
KENTUCKY...MAINLY IN THE FORM OF FLURRIES AND SPRINKLES. FLURRIES
HAVE BEEN REPORTED IN HARLAN AND LETCHER COUNTIES OVER THE PAST COUPLE
OF HOURS. THE LATEST HRRR AND NAM12 DO SHOW SOME LIGHT QPF FALLING OVER
PARTS OF EAST KENTUCKY THIS AFTERNOON AND INTO THE EVENING. THE
LATEST MID LEVEL SHORT WAVE PASSING THROUGH THIS AFTERNOON WILL BRING
A POCKET OF GOOD LIFT AND THIS SHOULD ENHANCE THE PCPN...GENERATING
A MORE CONVECTIVE LOOK AND FEEL TO THE RETURNS LATER THIS AFTERNOON
AND INTO THE EVENING. ANY SHOWER ACTIVITY WILL TAKE PLACE IN AN
ENVIRONMENT WITH SUB FREEZING TEMPERATURES JUST OFF THE SFC AND
THEREFORE COULD BE MIXED AT TIMES WITH SNOW OR SLEET. JUST ISOLATED
TO SCATTERED SHOWERS ARE EXPECTED...THOUGH...SO ACCUMULATION WILL NOT
BE AN ISSUE EVEN IN PLACES THAT MANAGE TO SEE A DECENT SHOWER.
ALSO...ROAD SFC TEMPERATURES...AND AIR TEMPERATURES BELOW 3500
FEET...WILL REMAIN WELL ABOVE FREEZING. WILL UPDATE THE FORECAST TO
FINE TUNE THE HIGH TEMPS AND FLATTEN THE DIURNAL CURVE. WILL ALSO
ADJUST THE POPS TOWARD THE LATEST GUIDANCE FROM THE NAM12 AND HRRR.
LOOKING AHEAD TO TONIGHT...THE MODELS HAVE NEARLY UNIFORMLY COME IN
COLDER FOR LOWS...ESPECIALLY IN THE WEST...SO WILL BE CONTINUING THE
FREEZE WARNING THERE. IT ALSO APPEARS THAT WE GET COLD ENOUGH IN THE
EAST TONIGHT TO GO AHEAD AND UPGRADE THEM TO A WARNING. LOOK FOR
UPDATES TO THE HWO...ZONES...AND NPW TO COME OUT SHORTLY...JUST AFTER
THE UPDATED GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 718 AM EDT THU OCT 24 2013
FRESHENED UP THE HOURLY TEMPERATURES...DEW POINTS...AND SKY COVER TO
JIVE BETTER WITH THE LATEST TRENDS IN OBSERVATIONS. OTHERWISE...THE
FORECAST REMAINS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 352 AM EDT THU OCT 24 2013
TEMPERATURES HAVE BEEN SLOWLY RISING OVERNIGHT THANKS TO THICKER
CLOUDS MOVING IN FROM THE NORTHWEST IN BROAD ONGOING CYCLONIC FLOW
ACROSS THE OHIO VALLEY. SINCE MOST LOCATIONS HAVE RISEN ABOVE
FREEZING...WITH THE EXCEPTION OF THE HIGHER ELEVATIONS IN THE
SOUTHEAST...HAVE CANCELLED THE FREEZE WARNING FOR THIS MORNING.
ONE MORE UPPER LEVEL IMPULSE WILL MOVE IN FROM THE NORTHWEST AND
BRING ISOLATED TO SCATTERED PRECIPITATION TO THE AREA...MAINLY THIS
AFTERNOON INTO THIS EVENING. STILL CAN NOT RULE OUT A FEW FLAKES EVEN
IN SOME OF THE VALLEYS IN THE EAST TOWARDS DUSK...HOWEVER NO
ACCUMULATION WILL OCCUR. THE HIGHEST TERRAIN BORDERING VIRGINIA
COULD SEE A DUSTING TO A QUARTER OF AN INCH OF SNOW ACCUMULATION.
THE LIGHT PRECIPITATION WILL LINGER LONGEST IN THE FAR EAST WITH THE
AID OF UPSLOPE FLOW...BUT LOOKS TO TAPER OFF BY AROUND MIDNIGHT.
TEMPERATURES WILL BOTTOM OUT WELL BELOW FREEZING FOR MOST AREAS
TONIGHT. AS SUCH...HAVE ISSUED A FREEZE WARNING FOR ALL BUT THE FAR
EAST...WHERE CLOUDS WILL LINGER THE LONGEST. GIVEN THE UNCERTAINTY
FOR THOSE LOCATIONS...WENT WITH A FREEZE WATCH.
RISING HEIGHTS AND AN AREA OF SURFACE HIGH PRESSURE WILL BRING A
MOSTLY SUNNY DAY TO EASTERN KENTUCKY ON FRIDAY. HIGHS WILL STILL BE
WELL BELOW NORMAL...GENERALLY IN THE MID TO UPPER 40S WITH THE COLD
AND FROSTY START TO THE DAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 329 AM EDT THU OCT 24 2013
ON FRIDAY NIGHT...THE MODELS ARE FORECASTING A TROUGH MOVING OFF THE
EAST COAST AND ANOTHER SHORT WAVE MOVING TO THE EAST SOUTHEAST JUST
ENTERING THE GREAT LAKES. AT THE SURFACE EASTERN KENTUCKY IS ON THE
BACK SIDE OF A SURFACE HIGH WITH A COLD FRONT EXTENDING FROM THE
GREAT LAKES TO THE PLAINS. THIS FRONT WILL BE PRETTY DRY AND WILL BE
FALLING APART AS IT MOVES ACROSS THE AREA ON SATURDAY NIGHT. THE
UPPER TROUGH FROM THE GREAT LAKES WILL MOVE ACROSS THE AREA BY
SUNDAY MORNING. THE UPPER FLOW BECOMES MORE ZONAL ON MONDAY AND AT
THE SURFACE A STATIONARY FRONT WILL EXTEND FROM LAKE ERIE TO NORTHERN
MISSOURI. THIS FRONT IS FORECAST TO APPROACH THE AREA ON TUESDAY AND
THEN MOVE ACROSS THE AREA BY TUESDAY NIGHT. THIS FRONT WILL THEN
MOVE BACK TO THE NORTH AS A WARM FRONT ON WEDNESDAY. THE FORECAST
AFTER MONDAY BECOMES VERY IFFY DUE TO THE UPPER LOW WHICH IS OFF THE
WEST COAST THAT IS FORECAST TO KICK ACROSS THE MOUNTAINS AND MOVE
TOWARD THE AREA. THE MODELS VARY GREATLY WITH THE MOVEMENT OF THE
UPPER LOW WHICH IS NOT A SURPRISE AS THIS TYPE OF TRANSITION IS
USUALLY PROBLEMATIC FOR THE MODELS. WILL BE WAITING TO SEE A LITTLE
BETTER MODEL AGREEMENT AND RUN TO RUN CONSISTENCY BEFORE CONFIDENCE
INCREASES FOR THE TUESDAY TO WEDNESDAY TIMEFRAME. FOR
TEMPERATURES...JUST NUDGES THE TEMPS TOWARD THE CONSENSUS MODEL
BLEND FOR NOW. WILL STAY WITH THE FREEZE WATCH FOR FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 718 AM EDT THU OCT 24 2013
ANOTHER UPPER LEVEL DISTURBANCE WILL BRING ISOLATED TO SCATTERED
PRECIPITATION TO THE AREA. ELEVATIONS ABOVE 2500 FEET WILL SEE SOME
SNOW MIX IN...WITH SNOW POSSIBLY BEING SEEN IN THE VALLEYS AFTER DUSK
IN THE FAR EAST...WHERE THE LIGHT SHOWERS WILL PERSIST THE LONGEST.
MOST LOCATIONS WILL SEE VFR CONDITIONS HOLD THROUGH THE PERIOD.
STRATOCU WILL RANGE FROM 3 TO 5K FEET AGL...ALTHOUGH ANY MORE
INTENSE SHOWER COULD TEMPORARILY LOWER THE CEILINGS DOWN TO MVFR
LEVELS...ESPECIALLY IN THE HIGHER TERRAIN IN THE EAST. WINDS WILL PICK
UP DURING THE DAY FROM THE WEST AT AROUND 10 KTS...WITH GUSTS IN THE
15 TO 20 KT RANGE...BEFORE DIMINISHING BY DUSK. SKIES WILL GRADUALLY
CLEAR OUT FROM WEST TO EAST LATER TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING FOR
KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.
FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106-108-109-111-112-114>117.
FREEZE WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR KYZ107-
110-113-118>120.
&&
$$
UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...JJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS BUFFALO NY
933 AM EDT THU OCT 24 2013
.SYNOPSIS...
COLD WESTERLY WINDS OVER LAKES ERIE AND ONTARIO ARE ALLOWING LAKE
EFFECT RAIN AND SNOW SHOWERS TODAY. A LULL IN LAKE EFFECT WILL OCCUR
EARLY FRIDAY BEFORE ANOTHER ROUND GETS GOING FRIDAY NIGHT.
ACCUMULATING LAKE SNOWS WILL OCCUR ACROSS THE TUG HILL...WESTERN
ADIRONDACKS AND HIGHER ELEVATIONS OF THE WESTERN SOUTHERN TIER. THE
UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH THE WEEKEND WITH
ANOTHER COLD FRONT BRINGING RAIN AND SNOW SHOWERS AND A THIRD ROUND
OF LAKE EFFECT LATE SATURDAY NIGHT. BELOW NORMAL TEMPERATURES WILL
CONTINUE RIGHT THROUGH THIS UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
FIRST ACCUMULATING LAKE EFFECT SNOW EVENT FOR THIS SEASON IN
UNDERWAY THIS MORNING SOUTHEAST OF LAKES ONTARIO AND ERIE. THE
SNOW IS HIGHLY ELEVATION DEPENDENT WITH RAIN OR A RAIN/SNOW MIX
BEING REPORTED AT LOWER ELEVATIONS.
OFF LAKE ONTARIO...
RADAR IMAGERY IS SHOWING A FAIRLY ORGANIZED BAND OF LAKE EFFECT IN
PLACE ACROSS OSWEGO COUNTY EXTENDING INTO ONEIDA. A SECOND NARROWER
BAND OF LAKE EFFECT HAS RECENTLY FORMED TO THE NORTH OF THE MAIN
BAND STREAMING ACROSS THE OSWEGO/JEFFERSON COUNTY BORDER INTO
CENTRAL LEWIS COUNTY. THE POSITION OF THE LAKE BANDS ARE A BIT
FURTHER SOUTH THAN PREVIOUS FORECASTS EXPECTED. WITH THE MAIN BAND
FOCUSED SOUTH OF THE TUG HILL...THIS MAY END UP KEEPING SNOW
ACCUMULATIONS SEVERAL INCHES BELOW WHAT WAS EXPECTED WITH A MORE
INTENSE BAND FURTHER NORTH ACROSS THE TUG. RADAR DERIVED ECHO TOPS
SHOWING THE AVERAGE HEIGHT/EQUILIBRIUM LEVEL IS AROUND 14-15 KFT.
THE SHALLOWER THAN EXPECTED NATURE OF THE LAKE BANDS HAS NOT
PRODUCED ANY RECENT LIGHTNING ACTIVITY BUT A FEW STROKES WERE
OBSERVED IN THE PRE-DAWN HOURS. RECENT MESOSCALE MODELS INCLUDING
THE HRRR AND RGEM FORECAST THE LAKE BAND TO LIFT NORTH FOR A FEW
HOURS THIS AFTERNOON AHEAD OF AN UPSTREAM MID-LEVEL TROUGH WEST OF
THE LAKES. BASED ON THIS GUIDANCE WILL KEEP CURRENT LAKE ADVISORY
AND WARNING IN EFFECT BUT CONTINUE TO MONITOR. WARMING TEMPS WILL
MAKE IT MORE DIFFICULT FOR SNOW TO FALL AT THE HIGHER ELEVATIONS BUT
DYNAMIC PROCESS WITHIN THE BAND MAY CONTINUE TO ALLOW FOR ALL SNOW.
OFF LAKE ERIE...
LAKE EFFECT IS MORE DISORGANIZED WITH AN MORE UNFAVORABLE FETCH
ACROSS THE LAKE. TWO DISORGANIZED BANDS ARE FOUND SOUTH OF BUFFALO.
ONE ACROSS SOUTHERN ERIE COUNTY AND THE OTHER CLOSER TO THE NY/PA
BORDER. A FEW REPORTS HAVE BEEN RECEIVED WITH 2-3 SLUSHY INCHES
ACROSS THE HIGHER TERRAIN. NOT EXPECTING MUCH MORE ADDITIONAL
ACCUMULATION DUE TO DISORGANIZED NATURE OF THE BANDS. RADAR ECHO
TOPS HERE SHOWING CONVECTION EVEN MORE SHALLOW ONLY AVERAGING AROUND
10KFT.
THIS AFTERNOON/EVENING...
EXPECT ALL BANDS OF LAKE EFFECT TO BECOME MORE CELLULAR IN NATURE
AND DISORGANIZED GOING INTO THE AFTERNOON AS THE HIGHER SUN ANGLE
CREATES SOME TURBULENT MIXING. A MID-LEVEL TROUGH JUST UPSTREAM OF
THE LOWER LAKES WILL SLOWLY SHIFT SOUTHEAST THROUGH THE DAY. THE
LAKE EFFECT BANDS SHOULD EVENTUALLY MAKE A LARGER SHIFT SOUTH GOING
INTO THE EVENING AS FLOW VEERS NORTHWESTERLY IN THE WAKE OF THIS
TROUGH.
TONIGHT...THE ONTARIO LAKE EFFECT BAND WILL SHIFT TO THE SOUTH SHORE
OF LAKE ONTARIO AND INLAND TO CENTRAL NY...WITH PRECIP AFFECTING
METRO ROCHESTER AND SYRACUSE...AND POSSIBLY AS FAR WESTWARD AS
NIAGARA COUNTY. SOME MODELS SUGGEST THE UPSTREAM CONNECTIONS WILL
ALLOW THE LAKE BAND TO AFFECT THE ENTIRE SOUTH SHORE OF LAKE ONTARIO
AFTER MIDNIGHT. LIKEWISE A SOUTHWARD DRIFT TO THE LAKE EFFECT PRECIP
OFF LAKE ERIE...WITH A LAKE HURON CONNECTION TAKING THE STRONGER
CORE OF THE BAND OUT OF OUR FORECAST AREA AND INTO THE ERIE PA
VICINITY. STILL EXPECT ANOTHER COATING OF SNOW ON THE HILLS OF
SOUTHERN CHAUTAUQUA COUNTY OVERNIGHT. LOWS TONIGHT WILL BE IN THE
LOWER TO MID 30S WITH MORE EXTENSIVE CLOUD COVER BLANKETING THE
REGION WITH LAKE INDUCED CLOUDS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
SHORT TERM FORECAST CONCERNS WILL CONTINUE TO DEAL WITH LINGERING
LAKE CONVECTION AND IMPACTS OF DEVELOPING WARM ADVECTION PATTERN
SATURDAY.
FRIDAY AND FRIDAY NIGHT LOOKS LIKE MUCH OF THE SAME AS THE PAST
COUPLE OF DAYS WITH SYNOPTIC MOISTURE AND COLD AIR REMAINING IN
PLACE AND INVERSION HEIGHTS STILL IN THE 15K-20K FOOT RANGE. EARLY
FRIDAY...ON GOING NORTHWEST FLOW LAKE EFFECT SHOWERS FOCUSED
PRIMARILY FROM ROCHESTER TO SYRACUSE OFF LAKE ONTARIO AND ACROSS
INTERIOR SECTIONS OF THE WESTERN SOUTHERN TIER OFF LAKE ERIE.
COVERAGE IS EXPECTED TO WANE DURING THE DAY WITH THE LOSS OF THE
DIURNAL COMPONENT. PRECIPITATION TYPE SHOULD BE MAINLY SNOW INLAND
FROM BOTH LAKES DURING THE MORNING HOURS WITH PERHAPS AN INCH
DEPENDING ON HOW ORGANIZED THE ACTIVITY IS.
BOUNDARY LAYER WINDS WILL BE BACKING LATER FRIDAY AND FRIDAY NIGHT
AS WEAK UPPER LEVEL RIDGING BUILDS IN. SOME DRY AIR ENTRAINMENT AND
LOWERING EQUILIBRIUM LEVELS WILL MAKE THE ENVIRONMENT LESS FAVORABLE
FOR LAKE EFFECT...ALTHOUGH WITH WHAT ACTIVITY THAT DOES GET
GENERATED WILL BE WORKING NORTHWARD WITH THE BACKING FLOW.
SATURDAY...LOW LEVEL WARM ADVECTION IS EXPECTED TO STRENGTHEN AS LOW
LEVEL JET IMPINGES UPON THE LOWER GREAT LAKES TO THE SOUTH OF THE
APPROACHING SURFACE LOW MOVING OUT OF NORTHWEST ONTARIO. THIS WILL
END THE LAKE EFFECT...BUT SPREAD AN AREA OF PRECIPITATION ACROSS
WESTERN AND CENTRAL NEW YORK DURING THE DAY INTO SATURDAY NIGHT...
LIKELY IN THE FORM OF RAIN ALTHOUGH MAY START AS A MIX OR ALL SNOW
ACROSS THE HIGHER TERRAIN.
THE STRENGTH OF THE LOW LEVEL JET WILL YIELD A WINDY DAY SATURDAY...
ESPECIALLY ACROSS THE NIAGARA FRONTIER WHERE THE POTENTIAL EXISTS
FOR WIND GUSTS OF 40 MPH OR GREATER.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LOW PRESSURE ASSOCIATED WITH AN EXITING SHORTWAVE WILL LIFT INTO
NORTHERN QUEBEC ON SUNDAY. THIS WILL SET UP A BRIEF LAKE EFFECT
EVENT EAST OF LAKE ONTARIO...WITH RAIN OR SNOW SHOWERS POSSIBLE.
EXPECT MORE SPARSE SHOWERS ACROSS THE SOUTHERN TIER. ALL OF THIS
SHOULD TAPER OFF LATE SUNDAY NIGHT AS HIGH PRESSURE NOSES TOWARD OUR
REGION.
ON MONDAY...OUR REGION WILL BE IN BETWEEN HIGH PRESSURE NEAR
PENNSYLVANIA AND A SHORTWAVE PASSING TO THE NORTH. THE 12Z GFS/GGEM
SUGGEST RIDGING WILL BE AMPLE TO KEEP WESTERN NEW YORK DRY...WITH
THE 12Z ECMWF FORECASTING A GLANCING BLOW BY THE SHORTWAVE. WITH THE
POSSIBILITY OF LAKE ENHANCEMENT DUE TO A WESTERLY FLOW AND MEAN 850
MB TEMPS OF -3C...WILL CARRY CHANCE POPS EAST OF LAKE ONTARIO.
ELSEWHERE WILL PROBABLY REMAIN DRY...WITH SEASONABLE TEMPERATURES
TOPPING OUT IN THE 50S.
A WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE EXITING SHORTWAVE WILL
STALL NEAR LAKE ONTARIO. THIS COMBINED WITH A NE FLOW SHOULD RESULT
IN SOME LINGERING CLOUDS...BUT LITTLE IN THE WAY OF
PRECIPITATION ON MONDAY NIGHT OR TUESDAY. AFTER THIS...A DEEP UPPER
LEVEL TROF IS FORECAST TO DROP ACROSS THE WESTERN U.S. WHICH WILL
SET UP A WSW FLOW ALOFT. BOTH THE 12Z GFS/ECMWF LIFT A WEAK SURFACE
LOW TOWARD OUR REGION TUESDAY NIGHT INTO WEDNESDAY...BUT DIFFER ON
TIMING WITH THE GFS NOTABLY FASTER. THIS WILL BRING A CHANCE OF RAIN
TUESDAY NIGHT AND WEDNESDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
COLD WEST-NORTHWEST WINDS WILL CONTINUE TO PRODUCE LAKE EFFECT
CLOUDINESS AND PRECIPITATION DOWNWIND OF LAKES ERIE AND ONTARIO.
KJHW WILL EXPERIENCE THE GREATEST IMPACT FROM LAKE EFFECT
CONDITIONS...WITH SNOW SHOWERS TRANSITIONING TO RAIN SHOWERS DURING
THE DAY...AND A RAIN/SNOW MIX THIS EVENING. IFR CONDITIONS WILL
CONTINUE TO BE IN PLACE THROUGH THE MORNING BUT MAY LIFT TO MVFR
THIS AFTERNOON. OUTSIDE OF LAKE EFFECT BANDS...CONDITIONS WILL
REMAIN VFR. TONIGHT IFR WILL RETURN TO KJHW AS THE LAKE EFFECT
SHIFTS SOUTH TOWARD KERI WITH THE APPROACH OF MID-LEVEL DISTURBANCE.
OUTLOOK...
FRIDAY...VFR/MVFR WITH SCATTERED SHOWERS.
SATURDAY...MVFR WITH SHOWERS.
SUNDAY AND MONDAY...VFR/MVFR WITH SCATTERED LAKE EFFECT SHOWERS.
&&
.MARINE...
SMALL CRAFT ADVISORIES REMAIN IN EFFECT FOR VIRTUALLY ALL OF THE
FORECAST ZONES WITH THE EXCEPTION OF THE LOWER NIAGARA AND UPPER
SAINT LAWRENCE RIVERS AS THE LOWER GREAT LAKES REMAIN UNDER COLD
NORTHWEST FLOW THAT IS GENERATING GUSTY WINDS. WAVES WILL BUILD
THROUGH TODAY AS WINDS BACK TO THE WEST AND FETCH INCREASES ACROSS
THE LAKES WITH WAVES BUILDING AS HIGH AS 7 FEET ON LAKE ERIE AND 9
FEET ON LAKE ONTARIO BEFORE BEGINNING TO SUBSIDE TONIGHT AS FLOW
ONCE AGAIN BACKS TO THE NORTHWEST AND BEGINS TO DIMINISH.
HIGH PRESSURE NOSING INTO THE GREAT LAKES FROM THE MIDWESTERN STATES
THIS WEEKEND WILL PROVIDE A BRIEF RESPITE FRIDAY BEFORE FRESHENING
SOUTHWESTERLY FLOW FRIDAY NIGHT WILL LIKELY BRING ANOTHER ROUND OF
SMALL CRAFT ADVISORIES WITH A POTENTIAL FOR GALES SATURDAY AS A
STRONG AREA OF LOW PRESSURE TRACKS NORTH OF THE GREAT LAKES. COLD
AIR BEHIND THIS SYSTEM WILL LIKELY KEEP SMALL CRAFT ADVISORY LEVEL
WINDS/WAVES ON THE LAKES THROUGH THE REST OF THE WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
NYZ006.
LAKE EFFECT SNOW WARNING UNTIL 11 PM EDT THIS EVENING FOR
NYZ008.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT FRIDAY FOR LEZ020-040-041.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT FRIDAY FOR
LOZ043-044.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT FRIDAY FOR LOZ042-045.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...TMA
LONG TERM...APFFEL
AVIATION...SMITH
MARINE...SMITH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
609 AM CDT THU OCT 24 2013
.UPDATE...
ISSUED AT 609 AM CDT THU OCT 24 2013
LATEST FOG/STRATUS LOOP ALONG WITH SURFACE OBSERVATIONS SHOW AN
AREA OF MVFR CIGS/MOSTLY CLOUDY TO CLOUDY SKIES ACROSS NORTHERN
NORTH DAKOTA MOVING SOUTHEAST WITH TIME. THE BEST MODEL THAT FITS
THE CURRENT LOCATION/SCENARIO IS THE HRRR CLOUD BASE HEIGHT/CEILING.
THE OVERALL TREND IS FOR AN EXPANSION OF THE MOSTLY CLOUDY SKIES
INTO CENTRAL AND PORTIONS OF SOUTHERN NORTH DAKOTA....INCLUDING
THE SOUTHWEST AND THE JAMES RIVER VALLEY IN PARTICULAR THROUGH MID
MORNING. A GRADUAL THINNING AND DISSIPATION IS FORECAST INTO THE
AFTERNOON. MAIN UPDATE WAS TO INCREASE SKY GRIDS THROUGH 18Z. REST
OF FORECAST ELEMENTS REMAIN ON TRACK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT THU OCT 24 2013
THE MAIN FOCUS OF THE SHORT TERM PORTION OF THE FORECAST IS THE
EXTENT OF CLOUD COVER FOR TODAY.
CURRENTLY...A SURFACE HIGH PRESSURE RIDGE AXIS EXTENDED FROM
NORTHWESTERN SASKATCHEWAN TO WESTERN NORTH DAKOTA INTO CENTRAL SOUTH
DAKOTA. SATELLITE LOOP CONTINUED TO SHOW A LARGE AREA OF LOW CLOUDS
- THOUGH NOT COMPLETELY OVERCAST - OVER MOST OF MANITOBA AND
SASKATCHEWAN...EAST OF THE HIGH PRESSURE RIDGE. THE LOW CLOUDS HAD
ENTERED FAR NORTH CENTRAL NORTH DAKOTA...MAINLY BOTTINEAU AND
ROLETTE COUNTIES. THE MODELS HINT AT MVFR CLOUDS OVER SOUTHWESTERN
SASKATCHEWAN. THERE WAS ALSO A BAND OF CLOUDS ON THE WESTERN SIDE OF
THE HIGH PRESSURE RIDGE AXIS...OVER SOUTHWESTERN
SASKATCHEWAN/SOUTHERN ALBERTA/EASTERN MONTANA TO THE BLACK HILLS IN
SOUTH DAKOTA.
THE SURFACE RIDGE AXIS IS PROGGED TO MOVE SOUTHEASTWARD TODAY. THE
MODELS OFFER DIFFERENT SOLUTIONS REGARDING LAYER MOISTURE
FIELDS...MAKING THE CLOUD COVER A LOW CONFIDENCE FORECAST.
HOWEVER...USING A BLEND OF THE MODELS DO NOT ENVISION A MOSTLY SUNNY
DAY - BUT MORE VARIABLE CLOUDINESS IN NATURE. HAVE LOWERED EXPECTED
HIGH TEMPERATURES FOR TODAY AS A RESULT - BUT ONLY SLIGHTLY - WITH
HIGHS IN THE LOWER 40S NORTHWEST THROUGH SOUTHEAST...AND MID 40S IN
SOUTHWESTERN NORTH DAKOTA.
TONIGHT AS THE SURFACE HIGH AXIS MOVES SOUTH AND EAST OF THE
FORECAST AREA...WINDS SHOULD BECOME SOUTHERLY/SOUTHWESTERLY OVER
WESTERN NORTH DAKOTA DURING THE EVENING...WITH WARM AIR ADVECTION
MOVING IN FROM THE WEST. EXPECT MINIMUM TEMPERATURES FOR TONIGHT TO
OCCUR DURING THE EVENING OVER WESTERN NORTH DAKOTA...WITH RISING
TEMPERATURES AFTER MIDNIGHT. CENTRAL NORTH DAKOTA WILL LIKELY SEE
STEADY TEMPERATURES AFTER MIDNIGHT. LOWS TONIGHT FROM THE MID 20S IN
THE JAMES RIVER VALLEY TO THE LOWER 30S IN THE WEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 340 AM CDT THU OCT 24 2013
A PROGRESSIVE FLOW CONTINUES WITH A BRIEF PERIOD OF WARMER AIR
FRIDAY...TURNING COOLER SATURDAY AND SUNDAY...FOLLOWED BY MUCH
COLDER AIR MONDAY THROUGH WEDNESDAY. UNCERTAINTY REMAINS HIGH IN
REGARDS TO POTENTIAL PLACEMENT OF SNOWFALL
ACCUMULATION...AMOUNTS...AND TIMING.
FOR FRIDAY...NORTHWEST FLOW ALOFT CONTINUES WITH A DRY COLD FRONT
SHIFTING THROUGH THE WEST IN THE MORNING...THEN CENTRAL NORTH DAKOTA
DURING THE AFTERNOON. NAM/GFS BUFKIT SOUNDINGS SUGGEST NEAR ADVISORY
WIND CRITERIA WITH SUSTAINED NORTHWEST WINDS BEHIND THE FRONT OF
NEAR 30 MPH ALONG AND NORTH OF HIGHWAY 2. WILL MAKE A MENTION OF
THIS IN THE HAZARDOUS WEATHER OUTLOOK AND LET SUBSEQUENT SHIFTS
LOOK AT THIS WITH THE LATEST SOUNDINGS FOR A POSSIBLE WIND
ADVISORY FRIDAY AFTERNOON. RIGHT NOW EXPECTING NORTHWEST WINDS OF
30 MPH WITH GUSTS TO 40 MPH. WINDS WILL BE WEAKER SOUTH OF HIGHWAY
2...BUT WILL REMAIN IN THE BREEZY CATEGORY. THE COOLER AIR BEHIND
THE FRONT WILL NOT REALLY MAKE A DENT UNTIL LATE AFTERNOON AND
INTO FRIDAY NIGHT. THUS AS IS THE CASE MANY TIMES...ADIABATIC
MIXING WILL ALLOW THE WARMER AIR ALOFT TO TRANSLATE TO THE SURFACE
THROUGH MID AFTERNOON WITH HIGHS PEAKING BETWEEN 50F AND 60F
BEFORE THE MAIN COLD AIR ADVECTION KICKS IN FRIDAY EVENING/NIGHT.
FOR SATURDAY AND SUNDAY...COLD AIR ADVECTION THROUGH MOST OF
SATURDAY WILL TRANSITION TO WARM AIR ADVECTION SATURDAY
EVENING/NIGHT WHICH IS AHEAD OF A STRONG ALBERTA TYPE CLIPPER COLD
FRONT. SATURDAY WILL BE DRY AND SLIGHTLY COOLER OVERALL...FOLLOWED
BY A NORTH TO SOUTH COLD FRONTAL PASSAGE SUNDAY. POST FRONTAL SNOW
STILL LOOKS ON TRACK FOR SUNDAY NIGHT AND MONDAY. HOWEVER THE MAIN
FOCUS LOOKS TO BE IN THE WEST AND SOUTHWEST WITH LIGHTER AMOUNTS
ACROSS CENTRAL NORTH DAKOTA.
FOR MONDAY AND TUESDAY...DESPITE COLD AIR IN PLACE FOR ALL
SNOW...UNCERTAINTY REMAINS IN REGARDS TO THE MOVEMENT OF THE
AFOREMENTIONED BAROCLINIC ZONE THAT INITIALLY RESIDES ALONG THE LEE
OF THE NORTHERN ROCKIES. THE GFS STEADILY PROGRESSES IT EAST
RESULTING IN WIDESPREAD SNOWS MONDAY NIGHT THROUGH TUESDAY NIGHT.
THE ECMWF IS SIMILAR INITIALLY...WITH SNOW IN THE WEST SUNDAY
EVENING THROUGH MONDAY EVENING...BUT SHUNTS THE MAIN BAROCLINIC ZONE
SOUTH AND EAST WITH SOME LIGHT SNOWFALL POTENTIAL JUST CROSSING
THE SOUTHERN BORDER MONDAY NIGHT. THE OVERALL TREND IN SNOWFALL
ACCUMULATION VIA THE ECMWF PAST FEW RUNS IS A SHIFT FURTHER WEST.
WILL MAKE NO CHANGES TO THE ALLBLEND SOLUTION FOR THE EXTENDED
GIVEN THE HIGH UNCERTAINTY. HIGH TEMPERATURES MONDAY AND TUESDAY
WILL BE IN THE LOWER 30S...WITH OVERNIGHT LOWS BETWEEN 15F AND 25.
FOR WEDNESDAY...HIGH PRESSURE DOMINATES WITH DRY AND CONTINUED COLD
CONDITIONS WITH HIGHS IN THE UPPER 30S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 609 AM CDT THU OCT 24 2013
A LARGE AREA OF MVFR CLOUD SHIELD OVER MOST OF MANITOBA AND MOST OF
NORTHERN AND SOUTHEASTERN SASKATCHEWAN CONTINUED MOVING SOUTHEAST
AND THE SOUTHERN EXTENT OF THE CLOUDS WAS OVER THE NORTHERN THIRD OF
NORTH DAKOTA. EXPECT KISN/KMOT TO HAVE MVFR CIGS UNTIL AROUND
16Z-18Z...THEN VFR CONDITIONS. FARTHER SOUTH...EXPECT MVFR CIGS TO
MOVE OVER KDIK/KBIS/KJMS AND THESE TAF SITES REMAIN MVFR UNTIL
AROUND 00Z. VFR OVERNIGHT TONIGHT WITH CALM WINDS BECOMING SOUTH.
SOME MVFR CIGS POSSIBLE OVER KDIK AFT 06Z WITH CLOUDS FORMING ON THE
BOUNDARY OF THE WARM ADVECTION MOVING IN FROM THE WEST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...JV
LONG TERM...KS
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
954 AM EDT THU OCT 24 2013
.SYNOPSIS...
A TROUGH WILL REMAIN OVER THE GREAT LAKES REGION THROUGH TONIGHT.
THE SURFACE TROUGH WILL WEAKEN ON FRIDAY AS HIGH PRESSURE BUILDS
OVER THE OHIO VALLEY. ANOTHER LOW PRESSURE SYSTEM WILL TRAVERSE THE
UPPER GREAT LAKES ON SATURDAY AND PUSH A COLD FRONT SOUTH ACROSS THE
AREA SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LAKE EFFECT SNOW CONTINUES ACROSS THE SNOWBELT THIS MORNING WITH
THE REGION FIRMLY IN THE GRIP OF A DEEP UPPER TROUGH. 12Z SOUNDINGS
ACROSS THE REGION SHOW AN IMPRESSIVELY DEEP WELL MIXED LAYER
EXTENDING FROM SURFACE TO NEAR 700 MB OR 10,000 FEET FROM DTX TO
PIT. THIS LAYER IS RATHER MOIST AS WELL. THE DEEP WELL MIXED LAYER
IS ALLOWING THE DEEPER LAKE EFFECT CONVECTION FROM LAKE MICHIGAN
TO PROGRESS WELL INLAND AND HELP DEEPEN THE MIXED LAYER OVER LAKE
ERIE. CLOUD TOP TEMPERATURES OF -20 TO -25C ARE EVIDENT ON THE IR
SATELLITE IMAGERY SO GOOD DENDRITE SNOWFLAKE GROW SHOULD OCCUR THIS
MORNING WITH THE LAKE EFFECT SNOW BANDS. THE LAKE EFFECT IS NEARLY
ALL SNOW THIS MORNING EVEN AT THE ERIE LAKE SHORE DESPITE A WARM
LAKE OF 10-15C. THIS MILD LAKE TEMPERATURE WITH 500 MB TEMPS DOWN
TO -32C HAS CREATED A SURFACE TO 500 MB TEMPERATURE DIFFERENCE OVER
40C WHICH IS A GOOD INDICATOR OF THUNDER POTENTIAL.
THE HRRR IS INDICATING A 4-6 INCH ACCUMULATION IN GAGA COUNTY
THROUGH 17Z WHICH SEEMS REASONABLE GIVEN THE INSTABILITY AND
CURRENT PLACEMENT OF LES BANDS. WE HAVE UPGRADED THE ADVISORY TO A
LAKE EFFECT SNOW WARNING. DIURNAL WARMING THIS AFTERNOON SHOULD
MAKE THE LES CONVECTION MORE CELLULAR AND SHOULD ALLOW FOR THE
SNOW TO MIX WITH OR CHANGE TO MOSTLY RAIN. ALTHOUGH WE WILL NEED TO
EXAMINE THIS MORE CLOSELY. HAVE LOWER MAX TEMPERATURES IN THE SNOW
BELT A FEW DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
GOOD COVERAGE OF RAIN AND SNOW SHOWERS WILL CONTINUE TONIGHT IN NE
OHIO/NW PA...ESPECIALLY IN THE SNOW BELT AREA. PRECIPITATION WILL
GRADUALLY TRANSITION FROM RAIN TO SNOW THIS EVENING AWAY FROM THE
LAKESHORE. DRIER AIR WILL INTRUDE FROM THE WEST WITH THE FLOW
STARTING TO BACK AND SHIFTING THE PRECIPITATION BACK TO THE
NORTHEAST FOR THE OVERNIGHT HOURS. ACCUMULATIONS WILL BE POSSIBLE
ONCE AGAIN WITH AN INCH OR TWO OF WET SLUSH. WE WILL HAVE TO WATCH
FOR A CONNECTION TO LAKE HURON DIRECTED TOWARDS NW PA. IF THIS
HAPPENS WE COULD SEE SOME HIGHER ACCUMULATIONS BUT WILL CARRY 1 TO
3 INCHES IN THE FORECAST FOR NOW. A FREEZE IS POSSIBLE FOR ALL BUT
THE LAKESHORE AREAS AGAIN TONIGHT WITH A HARD FREEZE POSSIBLE AS
YOU GET CLOSER TO CENTRAL OHIO.
THE FLOW CONTINUES TO BACK ON FRIDAY WITH PRECIPITATION BECOMING
MORE CONFINED TO THE LAKESHORE AREAS THROUGHOUT THE DAY. KEPT
POPS PRETTY HIGH GIVEN THE FAVORABLE INSTABILITY OVER THE LAKE BUT
WILL HAVE TO WATCH HOW FAST MID-LEVELS DRY OUT AS RIDGE STARTS TO
BUILD ALOFT.
SURFACE HIGH PRESSURE WILL BUILD OVER THE OHIO VALLEY FRIDAY AND
FRIDAY NIGHT...THEN SHIFT TO THE SOUTHEAST ON SATURDAY. WE GET A
BRIEF SHOT OF WARM ADVECTION AHEAD OF THE NEXT COLD FRONT WITH
TEMPERATURES NEAR 50 ON SATURDAY. THE NEXT COLD FRONT WILL MOVE
THROUGH SATURDAY NIGHT WITH HIGHS DROPPING BACK INTO THE 40S AGAIN
ON SUNDAY.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
MORE MINOR CHANGES TO THE LONG TERM THIS MORNING. MONDAY STILL
LOOKS TO BE DRY. THE NEW MODELS ARE SLOWER THAN LAST NIGHT WITH THE
SYSTEM MOVING OUT OF THE PLAINS NEXT TUESDAY. IT APPEARS THAT MUCH
OF TUESDAY WILL ALSO BE DRY WITH RAIN MOVING IN LATE TUESDAY AND
CONTINUING WEDNESDAY. HAVE FINED TUNED THE PRECIP CHANCES A
LITTLE. BIGGEST CHANGE IS TO LOWER PRECIP CHANCES TUESDAY...
ESPECIALLY IN THE EAST...AND TO BUMP THEM UP FOR WEDNESDAY. HAVE
ALSO BUMPED HIGH TEMPS UP A COUPLE OF DEGREES AS THERE SHOULD BE A
GOOD PUSH OF WARM AIR ADVECTION WITH THIS SYSTEM.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A BAND OF SNOW CONTINUES TO AFFECT PORTIONS OF NE OH AND NW PA
THIS MORNING. IT APPEARS THAT THE BAND WILL STAY JUST NORTH OF
KCLE SO WILL TRY FOR A DRY FORECAST. IT APPEARS THAT SNOW WILL
MOVE INTO KYNG SHORTLY AND ACTIVITY EXPECTED AT KERI IN A BIT. TEMPS
SHOULD WARM ENOUGH BY LATE MORNING TO CHANGE ALL OF THE PRECIP
BACK TO RAIN. CIGS FOR THE MOST PART WILL BE VFR BUT SOME PATCHES
OF MVFR ARE LIKELY. SOME MVFR CLOUDS HAVE MADE IT TO KTOL FROM
LAKE MICHIGAN. THESE SHOULD GO AWAY IN A COUPLE OF HOURS.
IMPROVING CONDITIONS ARE EXPECTED THE SECOND HALF OF THE PERIOD
WITH SKIES LIKELY BECOMING SCT OR SKC IN THE WEST. WESTERLY FLOW
WILL INCREASE THIS MORNING WITH GUSTS TO 20 KNOTS LIKELY THROUGH
THE AFTERNOON.
OUTLOOK...NON-VFR POSSIBLE THURSDAY NIGHT THROUGH FRIDAY IN RAIN
AND SNOW SHOWERS MAINLY NE OH/NW PA AND AGAIN SATURDAY NIGHT INTO
SUNDAY.
&&
.MARINE...
WILL NEED SMALL CRAFT ADVISORIES IN THE EAST FOR THE FORESEEABLE
FUTURE AS SUSTAINED WESTERLY WINDS WILL CONTINUE. WILL LET THE
SMALL CRAFT GO IN THE WESTERN BASIN AS PLANNED. WINDS WILL BECOME
SOUTHWEST LATE FRIDAY INTO SATURDAY AHEAD OF AN APPROACHING COLD
FRONT. EXPECT INCREASING SPEEDS AS THE FRONT APPROACHES BUT NO GALE
HEADLINES NEEDED AS THE STRONG FLOW ALOFT SHOULD HAVE A HARD TIME
MIXING DOWN TO THE SURFACE. THE FLOW WILL RETURN TO THE WEST OR
NORTHWEST BEHIND THE COLD FRONT WHICH WILL MOVE THROUGH LATE IN THE
DAY. THE FLOW WILL BECOME LIGHT AND VARIABLE FOR A TIME ON SUNDAY
BUT BY MONDAY WINDS WILL BE FROM THE EAST. THIS WILL HAPPEN IN
RESPONSE TO A STRONG LOW PRESSURE SYSTEM TAKING SHAPE OVER THE
PLAINS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR
OHZ011-012-014-022-023-089.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EDT THIS AFTERNOON FOR
OHZ013.
PA...LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR
PAZ001>003.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR LEZ145>149.
&&
$$
SYNOPSIS...KEC
NEAR TERM...LAPLANTE
SHORT TERM...LAPLANTE
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1149 AM MDT THU OCT 24 2013
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 229 AM MDT THU OCT 24 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS NW FLOW STILL IN PLACE
ACROSS NORTHERN AND CENTRAL PLAINS WITH CONFLUENT FLOW OVER THE
CENTRAL ROCKIES. AT THE SURFACE A COLD FRONT HAS STALLED ALONG THE
FRONT RANGE...EXTENDING SOUTH ACROSS THE TEXAS PANHANDLE.
IN THE NEAR TERM...DESPITE LITTLE IN THE WAY OF DEVELOPMENT SO FAR
EARLY THIS MORNING PATCHY FOG/STRATUS STILL SEEMS REASONABLE OVER
WESTERN LOCATIONS WITH TEMPS BEGINNING TO COOL TO WITH A FEW
DECREES OF TD VALUES. NAM/RAP/HRRR STILL SHOW BL MOISTURE
APPROACHING SATURATION IN THE WEST...WITH SOME VISIBILITY
RESTRICTIONS ADVERTISED BY MET GUIDANCE AND NAM. NOT REALLY
CONFIDENT IN COVERAGE...SO I PLAN ON LEAVING ONGOING FORECAST IN
PLACE.
WITH STORM TRACKS WELL NORTH AND SOUTH OF OUR CWA...AND
DRY AIR MASS (BELOW 700MB) IN PLACE OVER OUR CWA THROUGH SATURDAY
NIGHT I EXPECT DRY CONDITIONS TO CONTINUE. TEMPS TODAY WILL BE
ABOUT 10-15F COOLER THAN YESTERDAY (VALUES IN THE 50S)...WITH
COOLER POST FRONTAL AIR MASS IN PLACE. AS A SHORTWAVE TROUGH
PASSES OVER THE NORTHERN PLAINS FRIDAY AND CLOSED LOW OVER
SOUTHERN PLAINS (BOTH OUTSIDE OF OUR AREA OF CONCERN...WE WILL
BEGINNING OT SEE A SHIFT IN THE UPPER PATTERN ALLOWING FOR A
STRENGTHENING OF THE LEE TROUGH AND LIFTING OF A WARM FRONT OVER
OUR CWA. IN RESPONSE BREEZY/MILD CONDITIONS ARE EXPECTED
FRIDAY...WITH ONLY MID-HIGH CLOUDS IN OUR SOUTH. A COLD FRONT WILL
THEN DROP SOUTH BY SATURDAY MORNING WITH A BREEZY NW WIND DURING
THE MORNING HOURS. TEMPS MAY BE A LITTLE COOLER...HOWEVER THERE IS
NOT A LARGE DROP IN TEMPS ALOFT BEHIND THIS FROPA SO WE WILL
LIKELY STAY NEAR SEASONAL VALUES (60S).
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 229 AM MDT THU OCT 24 2013
SUMMARY...DRY AND MILD TO START NEXT WEEK BEFORE BECOMING COLDER
WITH A CHANCE OF WINTRY PRECIP BY MID-WEEK.
SUNDAY...FORECAST HAS BEEN LOOKING LIKE A LOCK FOR THE PAST FEW DAYS
WITH HIGHS IN THE LOW 70S UNDER THE INFLUENCE OF SOME MINOR RIDGING
AND WARM AIR ADVECTION.
MONDAY...A TRANSITIONAL DAY...PROBABLY. GUIDANCE HAS BEEN VERY
INCONSISTENT WITH THE MON-TUES-WED PERIOD FOR THE PAST FEW
DAYS...AND THE 00Z SUITE IS NOT ANY BETTER THAN EARLIER CYCLES.
GEM/ECMWF DEPICT THE COLD FRONT PUSHING SOUTH MONDAY INTO EARLY
TUESDAY...WHILE THE GFS DELAYS THE ARRIVAL UNTIL LATE TUESDAY.
BECAUSE OF THIS THE GFS DEPICTS A MILDER MONDAY WHILE OTHER GUIDANCE
INDICATES INCREASING CLOUDINESS AND ARRIVAL OF THE COLD LIMITING
HIGH TEMPS. THE GEFS MEMBERS SHOW A LARGE SPREAD...INCLUDING
DEPICTING SOLUTIONS MORE IN LINE WITH OTHER GUIDANCE. ULTIMATELY AM
THINKING IT WILL TURN OUT SOMEWHERE IN THE MIDDLE WITH WEAK WAA IN
EASTERN PARTS OF THE CWA AND INCREASING CLOUDS IN THE WEST.
TUESDAY AND WEDNESDAY...VERY LITTLE CONFIDENCE WHATSOEVER FOR THE
REST OF THE WEEK. GEFS/ECMWF ENS ARE ALL OVER THE PLACE...AND AS WPC
POINTS OUT BY TUES THE SYNOPTIC SOLUTIONS ARE MORE THAN 1000 MILES
APART AND THE SPREAD ONLY GROWS FROM THERE. BECAUSE OF THIS
UNUSUALLY LARGE SPREAD BELIEVE A MODEL CONSENSUS IS THE BEST
FORECAST AT THIS POINT. IT LOOKS LIKE THERE WILL BE A SURGE OF COLD
MID-WEEK THAT MAY BE ASSOCIATED WITH WINTRY PRECIP...BUT SINCE THE
EVEN THE LARGE SCALE PATTERN IS DIFFICULT TO PIN DOWN DID NOT SPEND
TOO MUCH TIME WITH WEATHER GRIDS AND SPECIFIC TIMING. SOME SOLUTIONS
INDICATE A DEEP ENOUGH MOISTURE PROFILE TO SUPPORT SOME PERIODS OF
RAIN/SNOW...BUT OTHERS ARE COMPLETELY DRY. THAT SAID...DO HAVE A
LITTLE CONFIDENCE IN TEMPS AS THE COLD WILL BE WIDESPREAD AND LAST
THROUGH THE END OF THE WEEK...BUT TEMPS WILL NOT BE OUT OF THE
ORDINARY...WITH THE COLDEST LOWS OVER THE WEEK IN THE 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1149 AM MDT THU OCT 24 2013
LOW STRATUS WITH CEILINGS IN THE MVFR CATEGORY WILL CONTINUE THIS
AFTERNOON AT BOTH GLD AND MCK WITH CEILINGS GRADUALLY RISING. GLD
HAS BEEN SCATTERED TO BROKEN OVER THE LAST COUPLE OF HOURS BUT A
TREND TOWARD BROKEN OR OVERCAST IS EXPECTED BASED ON SATELLITE
AND UPSTREAM OBS. THE TAF GENERALLY REFLECTS OB TRENDS AND SHORT
TERM MODEL GUIDANCE AND MAY BE SLIGHTLY OPTIMISTIC WITH REGARDS TO
DIMINISHING SKY COVER LATE THIS AFTERNOON OR EVENING. ADDITIONAL
AMENDMENTS MAY BE NEEDED TO ADJUST TIMING OF MVFR CATEGORY OVER
THE NEXT SEVERAL HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JJM
AVIATION...BRB
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
150 PM EDT THU OCT 24 2013
.UPDATE...
ISSUED AT 145 PM EDT THU OCT 24 2013
DID AN UPDATE MAINLY TO FINE TUNE TEMPERATURES THOUGH THE REST OF
THE AFTERNOON. ALSO TWEAKED POPS AND HONED IN ON THE BEST CHANCES OF
PCPN OCCURRING DURING THE EARLY EVENING HOURS. UPDATES HAVE BEEN SENT
TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1105 AM EDT THU OCT 24 2013
14Z SFC ANALYSIS SHOWS CYCLONIC FLOW OVER EAST KENTUCKY CONNECTED TO
A BROAD AREA OF LOW PRESSURE OFF TO THE NORTHEAST. THIS LOW CONTINUES
TO SEND COLD AIR INTO THE REGION...ALONG WITH PLENTY OF LOW AND MID
LEVEL CLOUDS. AS A RESULT...DO NOT ANTICIPATE MUCH OF A DIURNAL RISE
TODAY...GENERALLY LESS THAN 10 DEGREES. IN ADDITION...THERE IS SOME
VERY LIGHT PCPN FALLING...FROM THE CLOUDS BLANKETING EAST
KENTUCKY...MAINLY IN THE FORM OF FLURRIES AND SPRINKLES. FLURRIES
HAVE BEEN REPORTED IN HARLAN AND LETCHER COUNTIES OVER THE PAST COUPLE
OF HOURS. THE LATEST HRRR AND NAM12 DO SHOW SOME LIGHT QPF FALLING OVER
PARTS OF EAST KENTUCKY THIS AFTERNOON AND INTO THE EVENING. THE
LATEST MID LEVEL SHORT WAVE PASSING THROUGH THIS AFTERNOON WILL BRING
A POCKET OF GOOD LIFT AND THIS SHOULD ENHANCE THE PCPN...GENERATING
A MORE CONVECTIVE LOOK AND FEEL TO THE RETURNS LATER THIS AFTERNOON
AND INTO THE EVENING. ANY SHOWER ACTIVITY WILL TAKE PLACE IN AN
ENVIRONMENT WITH SUB FREEZING TEMPERATURES JUST OFF THE SFC AND
THEREFORE COULD BE MIXED AT TIMES WITH SNOW OR SLEET. JUST ISOLATED
TO SCATTERED SHOWERS ARE EXPECTED...THOUGH...SO ACCUMULATION WILL NOT
BE AN ISSUE EVEN IN PLACES THAT MANAGE TO SEE A DECENT SHOWER.
ALSO...ROAD SFC TEMPERATURES...AND AIR TEMPERATURES BELOW 3500
FEET...WILL REMAIN WELL ABOVE FREEZING. WILL UPDATE THE FORECAST TO
FINE TUNE THE HIGH TEMPS AND FLATTEN THE DIURNAL CURVE. WILL ALSO
ADJUST THE POPS TOWARD THE LATEST GUIDANCE FROM THE NAM12 AND HRRR.
LOOKING AHEAD TO TONIGHT...THE MODELS HAVE NEARLY UNIFORMLY COME IN
COLDER FOR LOWS...ESPECIALLY IN THE WEST...SO WILL BE CONTINUING THE
FREEZE WARNING THERE. IT ALSO APPEARS THAT WE GET COLD ENOUGH IN THE
EAST TONIGHT TO GO AHEAD AND UPGRADE THEM TO A WARNING. LOOK FOR
UPDATES TO THE HWO...ZONES...AND NPW TO COME OUT SHORTLY...JUST AFTER
THE UPDATED GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 718 AM EDT THU OCT 24 2013
FRESHENED UP THE HOURLY TEMPERATURES...DEW POINTS...AND SKY COVER TO
JIVE BETTER WITH THE LATEST TRENDS IN OBSERVATIONS. OTHERWISE...THE
FORECAST REMAINS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 352 AM EDT THU OCT 24 2013
TEMPERATURES HAVE BEEN SLOWLY RISING OVERNIGHT THANKS TO THICKER
CLOUDS MOVING IN FROM THE NORTHWEST IN BROAD ONGOING CYCLONIC FLOW
ACROSS THE OHIO VALLEY. SINCE MOST LOCATIONS HAVE RISEN ABOVE
FREEZING...WITH THE EXCEPTION OF THE HIGHER ELEVATIONS IN THE
SOUTHEAST...HAVE CANCELLED THE FREEZE WARNING FOR THIS MORNING.
ONE MORE UPPER LEVEL IMPULSE WILL MOVE IN FROM THE NORTHWEST AND
BRING ISOLATED TO SCATTERED PRECIPITATION TO THE AREA...MAINLY THIS
AFTERNOON INTO THIS EVENING. STILL CAN NOT RULE OUT A FEW FLAKES EVEN
IN SOME OF THE VALLEYS IN THE EAST TOWARDS DUSK...HOWEVER NO
ACCUMULATION WILL OCCUR. THE HIGHEST TERRAIN BORDERING VIRGINIA
COULD SEE A DUSTING TO A QUARTER OF AN INCH OF SNOW ACCUMULATION.
THE LIGHT PRECIPITATION WILL LINGER LONGEST IN THE FAR EAST WITH THE
AID OF UPSLOPE FLOW...BUT LOOKS TO TAPER OFF BY AROUND MIDNIGHT.
TEMPERATURES WILL BOTTOM OUT WELL BELOW FREEZING FOR MOST AREAS
TONIGHT. AS SUCH...HAVE ISSUED A FREEZE WARNING FOR ALL BUT THE FAR
EAST...WHERE CLOUDS WILL LINGER THE LONGEST. GIVEN THE UNCERTAINTY
FOR THOSE LOCATIONS...WENT WITH A FREEZE WATCH.
RISING HEIGHTS AND AN AREA OF SURFACE HIGH PRESSURE WILL BRING A
MOSTLY SUNNY DAY TO EASTERN KENTUCKY ON FRIDAY. HIGHS WILL STILL BE
WELL BELOW NORMAL...GENERALLY IN THE MID TO UPPER 40S WITH THE COLD
AND FROSTY START TO THE DAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 329 AM EDT THU OCT 24 2013
ON FRIDAY NIGHT...THE MODELS ARE FORECASTING A TROUGH MOVING OFF THE
EAST COAST AND ANOTHER SHORT WAVE MOVING TO THE EAST SOUTHEAST JUST
ENTERING THE GREAT LAKES. AT THE SURFACE EASTERN KENTUCKY IS ON THE
BACK SIDE OF A SURFACE HIGH WITH A COLD FRONT EXTENDING FROM THE
GREAT LAKES TO THE PLAINS. THIS FRONT WILL BE PRETTY DRY AND WILL BE
FALLING APART AS IT MOVES ACROSS THE AREA ON SATURDAY NIGHT. THE
UPPER TROUGH FROM THE GREAT LAKES WILL MOVE ACROSS THE AREA BY
SUNDAY MORNING. THE UPPER FLOW BECOMES MORE ZONAL ON MONDAY AND AT
THE SURFACE A STATIONARY FRONT WILL EXTEND FROM LAKE ERIE TO NORTHERN
MISSOURI. THIS FRONT IS FORECAST TO APPROACH THE AREA ON TUESDAY AND
THEN MOVE ACROSS THE AREA BY TUESDAY NIGHT. THIS FRONT WILL THEN
MOVE BACK TO THE NORTH AS A WARM FRONT ON WEDNESDAY. THE FORECAST
AFTER MONDAY BECOMES VERY IFFY DUE TO THE UPPER LOW WHICH IS OFF THE
WEST COAST THAT IS FORECAST TO KICK ACROSS THE MOUNTAINS AND MOVE
TOWARD THE AREA. THE MODELS VARY GREATLY WITH THE MOVEMENT OF THE
UPPER LOW WHICH IS NOT A SURPRISE AS THIS TYPE OF TRANSITION IS
USUALLY PROBLEMATIC FOR THE MODELS. WILL BE WAITING TO SEE A LITTLE
BETTER MODEL AGREEMENT AND RUN TO RUN CONSISTENCY BEFORE CONFIDENCE
INCREASES FOR THE TUESDAY TO WEDNESDAY TIMEFRAME. FOR
TEMPERATURES...JUST NUDGES THE TEMPS TOWARD THE CONSENSUS MODEL
BLEND FOR NOW. WILL STAY WITH THE FREEZE WATCH FOR FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 150 PM EDT THU OCT 24 2013
THE NEXT IN THE SERIES OF UPPER LEVEL DISTURBANCES WILL BRING
ISOLATED TO SCATTERED PRECIPITATION TO THE AREA LATE THIS AFTERNOON
AND THROUGH THE FIRST PART OF THE EVENING. ELEVATIONS ABOVE 2500 FEET
WILL SEE SOME SNOW MIX IN...WITH SNOW POSSIBLY BEING SEEN ELSEWHERE
IN THE FAR EAST DURING THE EVENING...WHERE SCATTERED SHOWERS WILL
PERSIST THE LONGEST. MOST LOCATIONS WILL SEE VFR CONDITIONS THROUGH
THE PERIOD...THOUGH DO EXPECT SOME STRATOCU DOWN INTO THE MVFR RANGE
FOR A TIME AROUND SUNSET BEFORE THESE BREAK UP TOWARD MIDNIGHT FROM
WEST TO EAST. BREEZY WEST TO NORTHWEST WINDS AT 10 TO 15 KTS WILL
SWITCH MORE TO THE NORTH LATER THIS EVENING AND SETTLE DOWN ONCE THE
SHOWERS MOVES OUT OF THE AREA. MOSTLY CLEAR CONDITIONS AND LIGHT
WINDS WILL BE THE RULE FOR FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING FOR
KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.
FREEZE WARNING FROM 2 AM TO 10 AM EDT FRIDAY FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...JJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
112 PM EDT THU OCT 24 2013
.SYNOPSIS...
ISSUED AT 340 AM EDT THU OCT 24 2013
THE DEEP UPPER TROUGH AND ASSOCIATED COLD AIR WHICH MOVED OVER
ONTARIO EARLIER THIS WEEK...WILL REMAIN NEARLY STATIONARY ACROSS THE
GREAT LAKES THROUGH THE WEEKEND. THE UPPER TROUGH WILL COMBINE WITH
A SERIES OF WEAKER STORM SYSTEMS FORECAST TO SWEEP OVER THE GREAT
LAKES...TO GENERATE A WINTRY RAIN SNOW MIX OVER NORTHERN MICHIGAN
THROUGH THE WEEKEND. TEMPERATURES WILL REMAIN NEARLY SEASONAL TO
SLIGHTLY BELOW NORMAL INTO THE BEGINNING OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 111 PM EDT THU OCT 24 2013
LAKE EFFECT CONTINUES AS EXPECTED...WITH PRECIP TYPE MAINLY RAIN
NOW NEAR THE COAST...AND STILL MORE OF A RAIN/SNOW MIX
INLAND...BUT WITH EVEN GAYLORD RECENTLY REPORTING JUST RAIN
OUTSIDE OF HEAVIER ECHOES. LATEST RAP GUIDANCE SUGGESTS MELTING
LAYERS JUST A TAD HIGHER THAN EARLIER FORECAST...AND NOT TERRIBLY
SURPRISING GIVEN THAT IT IS STILL OCTOBER AFTER ALL. NOT REALLY A
BIG DEAL SINCE ANY SNOW THROUGH LATE AFTERNOON WON`T ACCUMULATE
ANYWAY...WITH GOING HIGHS STILL LOOKING ON TRACK...THOUGH MAY HAVE
TO LOWER A FEW DEGREES HIGHEST SPOTS.
UPDATE ISSUED AT 1009 AM EDT THU OCT 24 2013
STEADY AS SHE GOES. FAIRLY CLASSIC LAKE EFFECT SETUP STILL IN
PLACE THIS MORNING AS WELL-DISCUSSED BY THE MID SHIFT
FORECASTER...FEATURING BROAD UPPER TROUGHING AND COLD AIR (H8
TEMP RIGHT AROUND -6C PER 12Z APX RAOB) FIRMLY ENTRENCHED ACROSS
THE REGION. NOTABLE LOWER LEVEL TROUGH FEATURE IS CURRENTLY
MEANDERING ASHORE FROM LAKE MICHIGAN...AND HAS NO DOUBT HELPED TO
INDUCE A BIT OF AN ADDITIONAL FLARE-UP OF ACTIVITY THE PAST FEW
HOURS...WITH SOME DOWNRIGHT HEAVY SNOWS NOTED IN A COUPLE
BANDS...ENHANCED BY A NICE CROSS-HAIR SIGNATURE THROUGH THE DGZ
(I.E. SOME BIG FLAKES AT TIMES). HAVE SEEN SOME DECENT TOTALS IN
THE 2-4" RANGE OVERNIGHT UP ACROSS THE HIGH SPOTS...INCLUDING
ROUGHLY 3" HERE AT THE OFFICE.
THE TREND OF SOME BEEFIER BANDS WILL CONTINUE FOR ANOTHER FEW
HOURS BEFORE DIURNAL PROCESSES TAKE HOLD...ESPECIALLY IN THE
ABSENCE OF ANY DEEPER LAYER SHEAR (ONLY ABOUT 15-ISH KNOTS) TO
HELP HOLD BANDING TOGETHER THROUGH THE DAY. SUBTLE LOSS OF MID
LEVEL TROUGHING WILL ALSO AID IN A SLOW BREAKDOWN OF THE BETTER
LAKE EFFECT PATTERN...BUT HAVE NO DOUBTS THAT BOUTS OF PRECIP WILL
CONTINUE DOWNWIND OF THE GREAT LAKES RIGHT ON THROUGH THE DAY.
JUST LIKE YESTERDAY...WILL PROBABLY SEE MAINLY FROZEN PRECIP UP
OVER THE HIGHER TERRAIN THERE THE SURFACE- BASED MELTING LAYER
WILL ONLY BE 1KFT THICK AT BEST...WITH MAINLY RAIN NEAR THE
COAST...THOUGH WITH PROBABLY SOME RIMED SNOWFLAKES/GRAUPEL IN ANY
HEAVIER SHOWERS. THINK THE MAJORITY OF THE ACCUMULATING SNOW IS
JUST ABOUT DONE AT THE MOMENT (SAVE FOR ONE OR TWO PERSISTENT
BANDS - ONE IN PARTICULAR OVER OTSEGO COUNTY)...AND PROBABLY SAFE
TO LET THE LES ADVISORY EXPIRE ON TIME AT 11AM. OUTSIDE OF
THAT...JUST SOME COSMETIC CHANGES...WITH GOING HIGHS MAINLY
LOW/MID 40S LOOKING JUST FINE.
UPDATE ISSUED AT 612 AM EDT THU OCT 24 2013
ADDED MANISTEE...BENZIE...LEELANAU AND GRAND TRAVERSE COUNTIES TO
THE LAKE EFFECT SNOW ADVISORY. RADAR RETURNS THERE HAVE BEEN JUST
AS IMPRESSIVE AS ANYWHERE. IT`S DIFFICULT...AS SHORELINE OBS HAVE
BEEN PREDOMINANTLY RAIN. HOWEVER...TEMPERATURES JUST INLAND HAVE
QUICKLY DIPPED INTO THE LOWER 30S...AND ESPECIALLY IN THE HIGHER
TERRAIN...SNOW IS LIKELY THE DOMINANT WEATHER TYPE WITH
ACCUMULATIONS. THE SNOW IS HEAVY TOO...AND SOME TREES MAY HAVE
LIMBS SNAP DUE TO THE WEIGHT OF THE SNOW.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 340 AM EDT THU OCT 24 2013
CURRENTLY...LAKE EFFECT RAIN/SNOW SHOWERS ARE INTENSIFYING AND
BECOMING MORE NUMEROUS. THE ALREADY FAVORABLE LAKE EFFECT
CONDITIONS OF COLD AIR OVER THE WARMER WATERS/DEEP INSTABILITY AND
APPRECIABLE MOISTURE ARE GETTING ENHANCED WITH AN APPROACHING SFC
TROUGH/GREATER LOW LEVEL CONVERGENCE...AS WELL AS ADDITIONAL
MOISTURE BEING THROWN INTO THE ATMOSPHERE. THIS ADDITIONAL
MOISTURE IS VERIFIED ON LATEST SATELLITE IMAGERY ROTATING
SOUTHWARD BEHIND THE SFC TROUGH...AND ASSOCIATED MID LEVEL TROUGH.
THE RAIN AND SNOW SHOWERS HAVE ALSO TRIED TO BAND A BIT MORE AS
THE LOW LEVEL FLOW HAS INCREASED AHEAD OF THE SFC TROUGH. COMBINED
WITH THE INCREASED INTENSITIES...HAS RESULTED IN SKIES ACTUALLY
CLEARING A BIT BETWEEN THE BANDS ACROSS THE ADVISORY COUNTIES. THE
STRONGER CELLS WERE MOST LIKELY...AND ACCORDING TO AREA
OBSERVATIONS...BRINGING JUST SNOW...EVEN TO COMMUNITIES CLOSE TO
THE WARMER LAKE MICHIGAN/WHITEFISH BAY WATERS. THAT SAID...THERE
WERE STILL MANY LOCATIONS...ESPECIALLY ACROSS NW LOWER...WHERE
TEMPERATURES WERE IN THE MIDDLE AND UPPER 30S. THIS HAS PRESENTED
A MORE DIFFICULT SCENARIO FOR DECENT ACCUMULATIONS TO OCCUR. THE
TROUGH HAS PASSED THROUGH MUCH OF EASTERN UPPER...AND A WEDGE OF
DRIER AIR AND SUBSIDENCE BEHIND THE SFC TROUGH HAS CALMED THINGS
DOWN UP THERE. THE LOCATION FOR THE BETTER SNOWFALL WILL CONTINUE
TO BE WHERE ADVERTISED...IN THE COLDER AREAS OF THE HIGHER TERRAIN
OF NW LOWER MICHIGAN...WHERE CURRENT SNOWS WERE MOST INTENSE...AND
ALSO WHERE THE SNOWFALL IS EXPECTED TO INTENSIFY EVEN MORE OVER
THE NEXT SEVERAL HOURS.
TODAY...THE LAKE EFFECT SNOW ADVISORY WILL CONTINUE THROUGH MOST
OF THIS MORNING DUE TO THE AFOREMENTIONED EXPECTATIONS IN SNOW
SHOWER INTENSITY...AND RIGHT DURING THE MORNING COMMUTE. THERE IS
SOME SLIGHT 1C WARMING SEEN AHEAD/WITH THE SFC TROUGH...WHICH MAY
SERVE TO LOWER SNOW-LIQUID RATIOS AND KEEP TEMPS UP JUST A TOUCH.
HOWEVER...THIS SEEMS MINOR AND DID NOT LET THAT ENTER INTO THE
SNOWFALL EXPECTATIONS OF 1 TO 3 INCHES OF WET SLUSHY SNOW FOR MOST
AREAS IN THE ADVISORY THROUGH THIS MORNING. THERE WILL ALSO BE
LOCALIZED HIGHER AMOUNTS OF SNOW...MAINLY IN THE HIGHER
TERRAIN...WHERE IT HAS BEEN COLDEST...AND FURTHEST AWAY FROM THE
WARMING INFLUENCE OF LAKE MICHIGAN. ACROSS EASTERN UPPER...AFTER A
PERIOD OF DOWNTIME IN THE SUBSIDENCE REGIME/DRYING BEHIND THE
TROUGH...THERE IS AN EXPECTATION FOR MORE NUMEROUS LAKE EFFECT
SNOW SHOWERS TO DEVELOP THROUGH THE DAY. AS THE LATE MORNING AND
AFTER WEARS ON HOWEVER...ANY ADDITIONAL ACCUMULATIONS WILL BE
INSIGNIFICANT. THIS GOES FOR NW LOWER MICHIGAN AS WELL...DESPITE
DEEPEST MOISTURE LINGERING THROUGH MOST OF THE DAY...AND MOST
WIDESPREAD RAIN/SNOW SHOWERS CONTINUING. HIGHS AGAIN IN THE LOWER
TO MIDDLE 40S.
TONIGHT...MINOR MID LEVEL RIDGING OVER THE REGION..AND WINDS
BECOMING LESS CYCLONIC IN THE 1000-850MB LAYER...ALTHOUGH STILL
MOSTLY UNIDIRECTIONAL OUT OF THE NW. MOISTURE IS STILL RELATIVELY
DEEP WITH INVERSION HEIGHTS STILL AT 8KFT OR SO. IT`S GONNA KEEP
PRODUCING PERIODIC MAINLY CELLULAR RAIN AND SNOW SHOWERS...WITH
SNOW BEING THE DEAL ON THE HIGHER TERRAIN. WITHOUT SIGNIFICANT
UPPER LEVEL FORCING OR LOW LEVEL CONVERGENCE ENHANCEMENTS THROUGH
MUCH OF THE NIGHT...SNOWFALL ISN`T EXPECTED TO BE AS GREAT. MAYBE
A COUPLE OF INCHES...CENTERED IN/AROUND THE INTERSECTION OF
OTSEGO/ANTRIM/KALKASKA AND CRAWFORD COUNTIES. SOMETHING TO WATCH
WILL BE THE ARRIVAL OF THE NEXT MID LEVEL TROUGH TOWARD
12Z/DAYBREAK/LATE LATE TONIGHT. THIS FEATURE IS ADVERTISING SOME
WEAK MID/UPPER LEVEL -DIVQ AND ENHANCED LOW LEVEL CONVERGENCE.
MAY NOT PLAY A HUGE PART IN SNOWFALL AMOUNTS WITH THE VERY LATE
ARRIVAL...BUT AN UPTICK IN COVERAGE/INTENSITY IS DEFINITELY
POSSIBLE FOR THE MORNING COMMUTE.
&&
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT THU OCT 24 2013
CHILLY...DAMP WEATHER SET TO CONTINUE FOR THE NEXT SEVERAL DAYS AS
DEEP LAYER TROUGHING REMAINS PROMINENT ACROSS THE GREAT LAKES. COLD
AIR LOOKS TO BE TEMPORARILY REINFORCED HEADING INTO THE END OF THE
WEEKEND AS A RATHER INTENSE CLIPPER SYSTEM CUTS THROUGH THE
REGION...BRINGING ADDITIONAL RAIN/SNOW CHANCES. LARGE SCALE PATTERN
STILL LOOKS TO UNDERGO SOME CHANGES HEADING INTO NEXT WORK WEEK (IN
NO SMALL PART TO THE EVENTUAL INGEST OF REMNANTS OF CURRENT FAR WEST
PACIFIC TYPHOON "FRANCISCO" INTO THE FLOW REGIME)...WITH RAPID EAST
PACIFIC RIDGE AMPLIFICATION. THIS SLIGHT WEST DISPLACEMENT OF CURRENT
WESTERN NOAM RIDGING WILL ALLOW STRONG ENERGY TO DIVE INTO THE
INTERMOUNTAIN WEST...FORCING DOWNSTREAM SPLIT FLOW DEVELOPMENT AND
DISPLACEMENT OF NORTHERN STREAM BACK INTO CANADA. WHILE COLDEST AIR
WILL RETREAT NORTH AS THIS OCCURS...STILL LOOKING AT A CONTINUATION
OF BELOW NORMAL TEMPERATURES RIGHT THROUGH THIS FORECAST PERIOD.
FORECAST CONCERNS CONTINUE TO CENTER ON ADDITIONAL RAIN AND SNOW
CHANCES...BOTH SYNOPTIC AND LAKE-DRIVEN...AS WELL AS TEMPERATURE
TRENDS.
AFTER A MULTI-PERIOD OF NEAR STEADY-STATE W TO NW LAKE EFFECT...
WINDS WILL QUICKLY BACK FRIDAY AHEAD OF EARLIER MENTIONED CLIPPER
SYSTEM. EARLY MORNING WNW LAKE EFFECT WILL STEADILY TRANSITION TO A
WEST TO SOUTHWEST FLOW PATTERN THROUGH THE DAY. BACKING WIND
FIELDS...DEPARTURE OF SYNOPTIC MOISTURE SUPPORT...AND LOWERING
INVERSION HEIGHTS ALL SUGGEST JUST LIGHT ACTIVITY. COLD THERMAL
PROFILES CONTINUE TO SUPPORT RAIN/SNOW MIXTURE ACROSS INTERIOR
REGIONS. EXCELLENT GUIDANCE SUPPORT FOR CLIPPER SYSTEM TO PASS OFF
TO OUR NORTH FRIDAY NIGHT INTO SATURDAY...WITH ITS TRAILING COLD
FRONT CUTTING ACROSS NORTHERN MICHIGAN DURING THE DAY SATURDAY. BEST
FORCED ASCENT EXPECTED TO REMAIN TO OUR NORTH WHERE MID LEVEL
DYNAMICS ARE MAXIMIZED. NOT A WHOLE LOT OF MOISTURE FOR INCOMING
FRONT TO ACT UPON. HOWEVER...OVER-WATER INSTABILITY REMAINS...AND
FORCED MOISTURE FLUX OF THE WATERS SHOULD ALLOW FOR A GOOD CHANCE OF
SHOWER...FIRST IN LEADING WAA REGIME...FOLLOWED BY FORCED FRONTAL
CONVERGENCE. THERMAL PROFILES REMAIN MARGINAL FOR RAIN/SNOW MIXTURE
ACROSS THE HIGHLANDS...WITH RAIN ELSEWHERE. POST-FRONTAL CAA REGIME
BRINGS ANOTHER ROUND OF LAKE EFFECT RAIN AND SNOW SHOWERS TO END THE
WEEKEND.
UNCERTAINTY REMAINS RATHER HIGH HEADING THROUGH NEXT WORK WEEK AS
EARLIER MENTIONED PATTERN CHANGE DEVELOPS. STRONG MID LEVEL CONFLUENCE
AXIS SUPPORTS STRONG SURFACE HIGH PRESSURE TO SETTLE ACROSS THE
NORTHERN LAKES RIGHT THROUGH MID WEEK. LAST SEVERAL RUNS OF THE
ECMWF HAS HAD THIS IDEA...AND ALSO SUPPORTS A SLOWER EJECTION OF
SOUTHWEST CONUS UPPER LOW. ABOVE LENDS CREDENCE FOR A SOUTHWARD
DISPLACED BAROCLINIC ZONE...FAR ENOUGH SOUTH TO SUPPORT DRY WEATHER
ACROSS OUR AREA UNTIL THE END OF THE WEEK (PERHAPS A FEW LIGHT
SHOWERS/SNOW SHOWERS SUNDAY NIGHT ALONG MOISTURE STARVED COLD
FRONT). LATEST GFS MUCH QUICKER EJECTING THIS WESTERN ENERGY AND
ALSO HAS BAROCLINIC AXIS MUCH FURTHER NORTH...BRINGING RAINS INTO
OUR AREA AS QUICKLY AS TUESDAY. SOUTHWEST CONUS ENERGY OFTEN SLOWER
TO EJECT THAN ANTICIPATED...WHICH FAVORS THE SLOWER END OF THE
GUIDANCE SPECTRUM. WILL TREND TOWARD THIS LESS AGGRESSIVE
SCENARIO...KEEPING JUST SLIGHT CHANCE RAIN MENTION TUESDAY AND
TUESDAY NIGHT...BELIEVING MAIN ACTION WILL STAY WELL TO OUR
SOUTHWEST UNTIL THE END OF THE WEEK (IF NOT A TOUCH LATER).
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 111 PM EDT THU OCT 24 2013
TYPICAL LAKE EFFECT SETUP WILL CONTINUE INTO TONIGHT...THOUGH WITH
A BIT LESS OVERALL COVERAGE EXPECTED THAN THE PAST 24 HOURS.
SHOULD STILL SEE PREDOMINANTLY SCATTERED TO OCCASIONALLY NUMEROUS RAIN
AT THE TERMINAL SITES...AND MAINLY CLOSE TO LAKE MICHIGAN
(PLN/TVC/MBL)...WITH CEILINGS MAINLY IN THE LOW END OF VFR
RANGE...THOUGH PERHAPS BRIEFLY DIPPING TO MVFR WITHIN ANY HEAVIER
SHOWERS. WINDS WILL GET A LITTLE GUSTY THROUGH EARLY EVENING...BUT
BECOME LIGHT OVERNIGHT...WITH PERHAPS SOME INLAND CLEARING TOWARD
APN AS THE FLOW GETS QUITE LIGHT AFTER 07Z. AN DECREASE IN RAIN
SHOWERS IS EXPECTED LATE TONIGHT INTO FRIDAY...WITH A FURTHER
INCREASE IN MID LEVEL CLOUDS AHEAD OF OUR NEXT APPROACHING WEATHER
SYSTEM.
&&
.MARINE...
ISSUED AT 340 AM EDT THU OCT 24 2013
PRETTY HAZARDOUS MARINE CONDITIONS WITH ONGOING SMALL CRAFT
ADVISORIES FOR MANY OF THE NEARSHORE WATERS THROUGH TODAY...AND
FOR LAKE MICHIGAN THROUGH TONIGHT. WINDS DO SUBSIDE FRIDAY...BUT
QUICKLY INCREASE BY FRIDAY NIGHT AND SATURDAY...WHILE BACKING OUT
OF THE SW IN ADVANCE OF LOW PRESSURE SET TO CROSS LAKE SUPERIOR.
GALE FORCE WINDS WILL BE POSSIBLE FOR MOST ALL OF LAKE
MICHIGAN...AND FOR PORTIONS OF THE LAKE HURON NEARSHORES. WINDS
ARE THEN EXPECTED TO SUBSIDE SUNDAY INTO THE BEGINNING OF THE NEXT
WORK WEEK.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LHZ345-
347>349.
GALE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY AFTERNOON FOR
LHZ349.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LMZ323-342-
344>346.
GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR
LMZ341-342-344>346.
LS...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LSZ321.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...MB
SHORT TERM...SD
LONG TERM...MB
AVIATION...LAWRENCE
MARINE...SD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1254 PM CDT THU OCT 24 2013
.UPDATE...
ISSUED AT 1255 PM CDT THU OCT 24 2013
UPDATE IS FOR SKY COVER TRENDS TODAY. AN AREA OF STRATUS CONTINUES
TO DROP SOUTH THIS AFTERNOON. LATEST SATELLITE SHOWS THE WESTERN
EDGE OF THE STRATUS OVER EASTERN MONTANA ERODING. HAVE UPDATED
THE SKY CONDITIONS WITH THE LATEST 16 UTC RUC MODEL RUN AS IT HAS
THE BEST GRASP OF THE CURRENT CLOUD COVER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT THU OCT 24 2013
THE MAIN FOCUS OF THE SHORT TERM PORTION OF THE FORECAST IS THE
EXTENT OF CLOUD COVER FOR TODAY.
CURRENTLY...A SURFACE HIGH PRESSURE RIDGE AXIS EXTENDED FROM
NORTHWESTERN SASKATCHEWAN TO WESTERN NORTH DAKOTA INTO CENTRAL SOUTH
DAKOTA. SATELLITE LOOP CONTINUED TO SHOW A LARGE AREA OF LOW CLOUDS
- THOUGH NOT COMPLETELY OVERCAST - OVER MOST OF MANITOBA AND
SASKATCHEWAN...EAST OF THE HIGH PRESSURE RIDGE. THE LOW CLOUDS HAD
ENTERED FAR NORTH CENTRAL NORTH DAKOTA...MAINLY BOTTINEAU AND
ROLETTE COUNTIES. THE MODELS HINT AT MVFR CLOUDS OVER SOUTHWESTERN
SASKATCHEWAN. THERE WAS ALSO A BAND OF CLOUDS ON THE WESTERN SIDE OF
THE HIGH PRESSURE RIDGE AXIS...OVER SOUTHWESTERN
SASKATCHEWAN/SOUTHERN ALBERTA/EASTERN MONTANA TO THE BLACK HILLS IN
SOUTH DAKOTA.
THE SURFACE RIDGE AXIS IS PROGGED TO MOVE SOUTHEASTWARD TODAY. THE
MODELS OFFER DIFFERENT SOLUTIONS REGARDING LAYER MOISTURE
FIELDS...MAKING THE CLOUD COVER A LOW CONFIDENCE FORECAST.
HOWEVER...USING A BLEND OF THE MODELS DO NOT ENVISION A MOSTLY SUNNY
DAY - BUT MORE VARIABLE CLOUDINESS IN NATURE. HAVE LOWERED EXPECTED
HIGH TEMPERATURES FOR TODAY AS A RESULT - BUT ONLY SLIGHTLY - WITH
HIGHS IN THE LOWER 40S NORTHWEST THROUGH SOUTHEAST...AND MID 40S IN
SOUTHWESTERN NORTH DAKOTA.
TONIGHT AS THE SURFACE HIGH AXIS MOVES SOUTH AND EAST OF THE
FORECAST AREA...WINDS SHOULD BECOME SOUTHERLY/SOUTHWESTERLY OVER
WESTERN NORTH DAKOTA DURING THE EVENING...WITH WARM AIR ADVECTION
MOVING IN FROM THE WEST. EXPECT MINIMUM TEMPERATURES FOR TONIGHT TO
OCCUR DURING THE EVENING OVER WESTERN NORTH DAKOTA...WITH RISING
TEMPERATURES AFTER MIDNIGHT. CENTRAL NORTH DAKOTA WILL LIKELY SEE
STEADY TEMPERATURES AFTER MIDNIGHT. LOWS TONIGHT FROM THE MID 20S IN
THE JAMES RIVER VALLEY TO THE LOWER 30S IN THE WEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 340 AM CDT THU OCT 24 2013
A PROGRESSIVE FLOW CONTINUES WITH A BRIEF PERIOD OF WARMER AIR
FRIDAY...TURNING COOLER SATURDAY AND SUNDAY...FOLLOWED BY MUCH
COLDER AIR MONDAY THROUGH WEDNESDAY. UNCERTAINTY REMAINS HIGH IN
REGARDS TO POTENTIAL PLACEMENT OF SNOWFALL
ACCUMULATION...AMOUNTS...AND TIMING.
FOR FRIDAY...NORTHWEST FLOW ALOFT CONTINUES WITH A DRY COLD FRONT
SHIFTING THROUGH THE WEST IN THE MORNING...THEN CENTRAL NORTH DAKOTA
DURING THE AFTERNOON. NAM/GFS BUFKIT SOUNDINGS SUGGEST NEAR ADVISORY
WIND CRITERIA WITH SUSTAINED NORTHWEST WINDS BEHIND THE FRONT OF
NEAR 30 MPH ALONG AND NORTH OF HIGHWAY 2. WILL MAKE A MENTION OF
THIS IN THE HAZARDOUS WEATHER OUTLOOK AND LET SUBSEQUENT SHIFTS
LOOK AT THIS WITH THE LATEST SOUNDINGS FOR A POSSIBLE WIND
ADVISORY FRIDAY AFTERNOON. RIGHT NOW EXPECTING NORTHWEST WINDS OF
30 MPH WITH GUSTS TO 40 MPH. WINDS WILL BE WEAKER SOUTH OF HIGHWAY
2...BUT WILL REMAIN IN THE BREEZY CATEGORY. THE COOLER AIR BEHIND
THE FRONT WILL NOT REALLY MAKE A DENT UNTIL LATE AFTERNOON AND
INTO FRIDAY NIGHT. THUS AS IS THE CASE MANY TIMES...ADIABATIC
MIXING WILL ALLOW THE WARMER AIR ALOFT TO TRANSLATE TO THE SURFACE
THROUGH MID AFTERNOON WITH HIGHS PEAKING BETWEEN 50F AND 60F
BEFORE THE MAIN COLD AIR ADVECTION KICKS IN FRIDAY EVENING/NIGHT.
FOR SATURDAY AND SUNDAY...COLD AIR ADVECTION THROUGH MOST OF
SATURDAY WILL TRANSITION TO WARM AIR ADVECTION SATURDAY
EVENING/NIGHT WHICH IS AHEAD OF A STRONG ALBERTA TYPE CLIPPER COLD
FRONT. SATURDAY WILL BE DRY AND SLIGHTLY COOLER OVERALL...FOLLOWED
BY A NORTH TO SOUTH COLD FRONTAL PASSAGE SUNDAY. POST FRONTAL SNOW
STILL LOOKS ON TRACK FOR SUNDAY NIGHT AND MONDAY. HOWEVER THE MAIN
FOCUS LOOKS TO BE IN THE WEST AND SOUTHWEST WITH LIGHTER AMOUNTS
ACROSS CENTRAL NORTH DAKOTA.
FOR MONDAY AND TUESDAY...DESPITE COLD AIR IN PLACE FOR ALL
SNOW...UNCERTAINTY REMAINS IN REGARDS TO THE MOVEMENT OF THE
AFOREMENTIONED BAROCLINIC ZONE THAT INITIALLY RESIDES ALONG THE LEE
OF THE NORTHERN ROCKIES. THE GFS STEADILY PROGRESSES IT EAST
RESULTING IN WIDESPREAD SNOWS MONDAY NIGHT THROUGH TUESDAY NIGHT.
THE ECMWF IS SIMILAR INITIALLY...WITH SNOW IN THE WEST SUNDAY
EVENING THROUGH MONDAY EVENING...BUT SHUNTS THE MAIN BAROCLINIC ZONE
SOUTH AND EAST WITH SOME LIGHT SNOWFALL POTENTIAL JUST CROSSING
THE SOUTHERN BORDER MONDAY NIGHT. THE OVERALL TREND IN SNOWFALL
ACCUMULATION VIA THE ECMWF PAST FEW RUNS IS A SHIFT FURTHER WEST.
WILL MAKE NO CHANGES TO THE ALLBLEND SOLUTION FOR THE EXTENDED
GIVEN THE HIGH UNCERTAINTY. HIGH TEMPERATURES MONDAY AND TUESDAY
WILL BE IN THE LOWER 30S...WITH OVERNIGHT LOWS BETWEEN 15F AND 25.
FOR WEDNESDAY...HIGH PRESSURE DOMINATES WITH DRY AND CONTINUED COLD
CONDITIONS WITH HIGHS IN THE UPPER 30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1255 PM CDT THU OCT 24 2013
A WIDESPREAD LAYER OF STATUS WITH CEILINGS AT OR NEAR MVFR
CONDITIONS IS OVER ALL TAF SITES IN CENTRAL AND WESTERN NORTH
DAKOTA. EXPECT THIS LAYER TO SLOWLY ERODE WEST TO EAST THROUGH THE
AFTERNOON AND EVENING...AS SOME SIGNS OF EROSION OF THE CLOUD LAYER
IS ALREADY SHOWING ACROSS EASTERN MONTANA. WINDS WILL ALSO
TRANSITION FROM NORTHWEST TO SOUTHERLY FROM WEST TO EAST
OVERNIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MM
SHORT TERM...JV
LONG TERM...KS
AVIATION...MM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
259 PM CDT THU OCT 24 2013
.TONIGHT AND FRIDAY...FORECAST CONFIDENCE IS LOW TO MEDIUM.
BROKEN STRATUS/STRATOCUMULUS CLOUDS SHOULD CONTINUE TO LINGER INTO
THE EVENING ACROSS THE AREA INTO THE AFTERNOON...AS AREA FORECAST
SOUNDINGS CONTINUE TO SHOW WEAK LOW LEVEL INSTABILITY AND GOOD LOW
LEVEL MOISTURE.
SOME SPRINKLES AND FLURRIES MAY SHIFT THROUGH THE AREA INTO EARLY
EVENING. MORE ORGANIZED RAIN/SNOW SHOWERS OVER NORTHEAST WISCONSIN
ARE WITHIN COLD 500MB TEMPERATURE AREA OF AROUND 30 DEGREES BELOW
ZERO CELSIUS. THESE MAY CLIP THE FAR NORTHEAST COUNTIES INTO EARLY
EVENING IF THEY HOLD TOGETHER...THOUGH MOST SHOULD STAY NORTHEAST OF
THE AREA.
MAIN ISSUE WILL BE CLOUD TRENDS AND LOWS LATER TONIGHT INTO EARLY
FRIDAY MORNING. HRRR MODEL SHOWING CURRENT CLOUDS UPSTREAM OF THE
AREA MIXING OUT DURING THE EVENING...WITH MOSTLY CLEAR SKIES LATER
TONIGHT. THIS WOULD ALLOW LOWS TO DROP QUITE A BIT...AS WINDS WEAKEN
LATER TONIGHT. HOWEVER...SOMEWHAT SIMILAR SETUP YESTERDAY RESULTED
IN CLOUDS LINGERING THROUGH THE NIGHT. TRICKY CLOUD FORECAST.
FOR NOW...WENT WITH A COMPROMISE WITH NEIGHBORING OFFICES AND KEPT
SOME CLOUDS LATER TONIGHT AND EARLY FRIDAY MORNING. LOWS WERE KEPT
IN THE MID TO UPPER 20S ACROSS THE AREA. THESE COULD DROP LOWER IF
CLOUDS CLEAR OUT.
SOME STRATOCUMULUS SHOULD DEVELOP WITH DAYTIME HEATING ON
FRIDAY...MORE SO IN THE NORTHEAST PORTIONS OF THE AREA. SOUTHWEST
WINDS WILL GRADUALLY INCREASE DURING THE DAY...BECOMING GUSTY BY
AFTERNOON. HIGHS WILL BE A BIT WARMER WITH SOME WARM AIR
ADVECTION...IN THE MID TO UPPER 40S.
.FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE IS HIGH.
A SHARP TROF/COLD FRONT DIVES INTO THE AREA FRIDAY NIGHT...REACHING
THE SOUTHEAST CORNER OF THE FORECAST AREA BY 12Z SATURDAY. THE
PRESSURE GRADIENT IS IMPRESSIVE AHEAD OF THE FRONT AND WE/D BE
NEAR WIND ADVISORY LEVELS IF IT WAS OCCURRING DURING THE DAYTIME.
BUT...THERE SHOULD BE ENOUGH OF A LOW LEVEL INVERSION FRIDAY NIGHT TO
LIMIT MIXING OF THE HIGHER WINDS ALOFT. MOISTURE LOOKS LIMITED AND
FOR THE MOST PART...THE TROF/FRONT SHOULD COME THROUGH DRY. THE
WARM AIR ADVECTION/FRONTOGENESIS ALONG AND AHEAD OF THE FRONT IS
DECENT SO FOR NOW WILL JUST PUT IN SOME SPRINKLES ACROSS THE
NORTHEAST CWA LATE FRIDAY NIGHT. SATURDAY LOOKS CLOUDY...BREEZY AND COLD
IN THE WAKE OF THE FRONT.
.SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE IS MEDIUM TO
HIGH.
HIGH PRESSURE WILL KEEP IT QUIET BUT STILL CHILLY...HIGHS STILL IN
THE 40S.
.SUNDAY NIGHT AND MONDAY...FORECAST CONFIDENCE IS MEDIUM.
ANOTHER DRY COLD FRONT IS EXPECTED TO SLIDE THROUGH THE AREA
SUNDAY NIGHT. NORTHEAST WINDS ON MONDAY...ALONG WITH DELTA T/S
OVER LAKE MICHIGAN APPROACHING 15C COULD RESULT IN SOME LAKE
EFFECT SPRINKLES ACROSS THE SOUTHEAST. TOO WARM FOR ANY SNOW.
.MONDAY NIGHT AND BEYOND...FORECAST CONFIDENCE IS LOW TO MEDIUM.
MODEL DISAGREEMENT INCREASES HEADING INTO THIS PERIOD. THE COLD
FRONT THAT CAME THROUGH SUNDAY NIGHT WILL LAY OUT A STRONG BAROCLINIC
ZONE STRETCHING FROM THE GREAT LAKES BACK WEST THROUGH IOWA AND
NEBRASKA. CYCLOGENESIS KICKS IN OVER THE CENTRAL HIGH PLAINS AND
LOW PRESSURE IS FORECAST TO INTENSIFY AS IT LIFTS NORTHEAST INTO
OUR AREA. THE GFS/ECMWF/GEM ARE DISAGREEING ON THE TIMING OF THE
INITIAL PRECIP ARRIVAL WITH THE GFS THE FASTEST OF THE THREE. THE
INITIAL RAIN COULD ARRIVE LATE MONDAY NIGHT. THE MODELS HAVE COME
INTO BETTER AGREEMENT WITH TRENDS IN THE WAKE OF THE FIRST LOW
THAT COMES THROUGH TUESDAY THROUGH TUESDAY NIGHT. WE COULD SEE DRY
WEATHER ON WEDNESDAY AS HIGH PRESSURE BRIEFLY BUILDS IN...BUT
WE/LL KEEP A CHANCE IN THE FORECAST GIVEN THE UNCERTAINTY. THEN A
SECONDARY LOW PRESSURE SYSTEM IS EXPECTED TO ROLL THROUGH SOMETIME
DURING THE WEDNESDAY NIGHT/THURSDAY TIME FRAME. ALL OF THIS WILL
BE RAIN...NO SNOW MIXING IN AS WELL AS NO THUNDER. RAINFALL
AMOUNTS FOR THE FIRST ROUND ARE ONLY ON THE ORDER OF ABOUT 1/4
INCH OF RAIN. OVERALL...A RATHER UNSETTLE PERIOD OF WEATHER NEXT
WEEK.
&&
.AVIATION/00Z TAFS/...
VFR CEILINGS ARE EXPECTED TO LINGER INTO THIS EVENING ACROSS TAF
SITES. OUTSIDE SHOT AT MVFR CEILINGS...BUT WILL NOT MENTION IN TAFS
DUE TO SPORADIC NATURE. SCATTERED SPRINKLES AND FLURRIES ARE
POSSIBLE INTO EARLY EVENING AS WELL. BRISK NORTHWEST WINDS WITH
GUSTS TO AROUND 15 KNOTS ARE EXPECTED UNTIL SUNSET...THEN WILL BACK
WEST AND WEAKEN SOMEWHAT TONIGHT.
TRICKY CLOUD FORECAST FOR LATER TONIGHT AND EARLY FRIDAY. CLOUDS MAY
DIMINISH LATER TONIGHT AND EARLY FRIDAY MORNING...AS DRIER AIR WORKS
INTO THE REGION. HOWEVER...CLOUDS LINGERED LAST NIGHT WITH A
SOMEWHAT SIMILAR SETUP. FOR NOW...KEPT SCATTERED WORDING FOR LATER
TONIGHT INTO FRIDAY MORNING.
MAINLY SCATTERED VFR CEILINGS WITH DIURNAL CUMULUS ARE EXPECTED BY
FRIDAY AFTERNOON WITH DAYTIME HEATING. SOUTHWEST WINDS WILL INCREASE
AND BECOME GUSTY BY AFTERNOON. GUSTS TO AROUND 20 KNOTS ARE POSSIBLE
DURING THE AFTERNOON.
&&
.MARINE...
NORTHWEST WINDS OF 10 TO 20 KNOTS ARE EXPECTED INTO EARLY THIS
EVENING...WITH SOME GUSTS TO 25 KNOTS NEAR AND OVER THE OPEN WATERS
OF LAKE MICHIGAN. 2 TO 4 FOOT WAVES...HIGHEST TOWARD THE OPEN
WATERS...ARE ALSO EXPECTED. WILL NOT ISSUE A SMALL CRAFT
ADVISORY...AS HIGHEST GUSTS SHOULD BE NEAR OR OVER THE OPEN WATERS.
GALE WATCH CONTINUES FOR FRIDAY NIGHT INTO SATURDAY MORNING ACROSS
THE NEARSHORE WATERS. TIGHT PRESSURE GRADIENT DEVELOPS ACROSS THE
AREA DURING THIS TIME...WITH 35 KNOT WINDS JUST ABOVE THE SURFACE
POSSIBLY MIXING DOWNWARD. COULD SEE SLIGHTLY HIGHER GUSTS IF 40 PLUS
KNOT WINDS FROM 1000 FEET ABOVE THE SURFACE MIX DOWN. WINDS ARE
EXPECTED TO REMAIN SOUTHWESTERLY DURING THIS TIME...SO HIGH WAVES
SHOULD BE OVER THE OPEN WATERS.
SMALL CRAFT ADVISORY LEVEL WINDS SHOULD LINGER LATER SATURDAY INTO
SATURDAY NIGHT...WITH BRISK NORTHWEST WINDS. AS THE PRESSURE
GRADIENT WEAKENS...WINDS WILL SUBSIDE BY LATER SATURDAY NIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY MORNING FOR
LMZ643>646.
&&
$$
TONIGHT/FRIDAY AND AVIATION/MARINE...WOOD
FRIDAY NIGHT THROUGH THURSDAY...DAVIS
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 258 PM CDT THU OCT 24 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A DEEP UPPER
TROUGH MOVING VERY LITTLE OVER THE NORTHEAST UNITED STATES...WHILE
SURFACE CYCLONIC FLOW EXTENDS INTO NORTH DAKOTA. LIKE
YESTERDAY...DIURNAL CU FILLED IN THE HOLES IN THE BROKEN CLOUD
DECK...WITH SOME RAIN AND SNOW SHOWERS DEVELOPING MAINLY OVER
NORTHEAST WISCONSIN. MEANWHILE...LAKE EFFECT SNOW SHOWERS CONTINUE
TO IMPACT NORTH-CENTRAL WISCONSIN WHERE VISIBILITIES SPORADICALLY
FALL TO A HALF MILE. NO REPORTS OF ANY SIGNIFICANT ACCUMS...AND
WEBCAMS ONLY SHOW WET ROADWAYS. EVEN FARTHER WEST...SURFACE HIGH
PRESSURE EXTENDS ACROSS THE GREAT PLAINS. AS THIS SURFACE HIGH
MOVES EAST AND THE DEEP UPPER TROUGH DEPARTS...LAKE EFFECT SNOW
IMPACTS AND CLOUD TRENDS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE DEEP UPPER TROUGH WILL FINALLY BEGIN TO DEPART THE
REGION LATE TONIGHT...WHILE THE SURFACE RIDGE AXIS WILL MOVE ACROSS
THE NORTHERN MISSISSIPPI VALLEY AND WESTERN WISCONSIN AT THE SAME
TIME. UNTIL THIS RIDGE AXIS ARRIVES...COLD NORTHWEST FLOW WILL
CONTINUE TO PREVAIL WHICH WILL KEEP SCATTERED LAKE EFFECT SNOW
SHOWERS GOING ACROSS NORTH-CENTRAL WISCONSIN. WIND TRAJECTORIES
ARE MORE WESTERLY THAN LAST NIGHT...SO ACCUMS SHOULD GENERALLY BE
UNDER AN INCH. ELSEWHERE...PLENTY OF CLOUD COVER UPSTREAM TO ROTATE
ACROSS THE REGION WHICH SHOULD KEEP SKIES ON THE BKN TO OVC SIDE
UNTIL LATE. SOME HOLES ARE LIKELY TO DEVELOP...MORE LIKELY OVER
NORTHEAST WISCONSIN IN THE DOWNSLOPING AREAS. LOW TEMPS REMAIN
DIFFICULT...DUE TO THE NATURE OF THE CLOUD COVER. WHERE HOLES
FORM...TEMPS ARE LIKELY TO BE COLDER THAN THE SURROUNDING AREAS.
WILL RAISE MIN TEMPS A DEGREE OR TWO.
THURSDAY...THE SURFACE RIDGE AXIS WILL QUICKLY MOVE ACROSS THE STATE
DURING THE MORNING. AS WINDS BACK TO THE SOUTHWEST...ANY LINGERING
LOW CLOUDS SHOULD BE ON THE WAY OUT AS DRIER AIR ADVECTS FROM THE
WEST. THE DRIER AIR SHOULD PREVENT SHOWERS FROM DEVELOPING DESPITE
THE WARM/MOIST ADVECTION DEVELOPING IN THE AFTERNOON. HOWEVER...MID AND HIGH
CLOUDS WILL BE ON THE INCREASE THROUGH THE DAY AHEAD OF A SOUTHEAST
MOVING SURFACE LOW OVER WESTERN ONTARIO. SOUTHWEST WINDS WILL TURN
A BIT BREEZY DURING THE AFTERNOON WITH DECENT MIXING. HIGHS WILL BE
RANGING THROUGH THE 40S.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 258 PM CDT THU OCT 24 2013
STRENGTHENING SURFACE LOW MOVING ACROSS SOUTHERN
ONTARIO AND LAKE SUPERIOR WILL PRODUCE A STRONG LOW LEVEL JET
FRIDAY NIGHT AND EARLY SATURDAY AND KEEP THE ATMOSPHERE WELL MIXED
AND HOLD TEMPERATURES UP FROM WHERE THEY HAVE BEEN LATELY.
IMPRESSIVE LOW LEVEL CONVERGENCE COMBINED WITH SUBSTANTIAL UPPER
LEVEL SUPPORT SHOULD NORMALLY MAKE FOR A NICE LINE OF SHOWERS AND
THUNDERSTORMS BUT THE AIR IS VERY DRY WITH PRECIPITABLE WATER ONLY
.3 TO .5 INCHES FRIDAY NIGHT. SO ONLY SCATTERED OR ISOLATED
SHOWERS EXPECTED.
THE COLD FRONT MOVES THROUGH EARLY SATURDAY BUT THE AIR IS NOT AS
COLD BEHIND IT AS THE LAST COUPLE OF FRONTS. IN ADDITION 925 AND
850MB WINDS ARE ONLY FAVORABLE FOR LAKE EFFECT SNOW SATURDAY
AFTERNOON AND EVENING SO DO NOT EXPECT MUCH SNOW IN THE NORTH WOODS
SNOWBELT REGION AS A RESULT. MAINLY DRY SUNDAY AND MONDAY WITH
TEMPERATURES A FEW DEGREES BELOW NORMAL AS LARGE SURFACE HIGH
BUILDS IN FROM THE NORTHWEST.
THE GFS BRINGS A SURFACE LOW FROM THE OKLAHOMA AND TEXAS
PANHANDLES MONDAY AFTERNOON TO CHICAGO TUESDAY NIGHT AND WOULD
BRING MOSTLY RAIN TO THE AREA TUESDAY AFTERNOON AND EVENING WHILE
THE ECMWF HAS A MUCH WEAKER INVERTED TROUGH TUESDAY NIGHT THAT
WOULD BRING ONLY LIGHT RAIN TO THE SOUTHEAST HALF OF THE FORECAST
AREA.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1219 PM CDT THU OCT 24 2013
COLD NORTHWEST FLOW OFF LAKE SUPERIOR WILL CONTINUE TO IMPACT
NORTH-CENTRAL WISCONSIN WITH BANDS OF SNOW SHOWERS. OVERALL
INTENSITY OF THE BANDS SHOULD WANE THIS AFTERNOON...BUT OCCASIONAL
IFR VSBYS/CIGS ARE POSSIBLE IN THE MORE INTENSE BANDS.
OTHERWISE...MVFR CIGS OVER CENTRAL AND NORTH-CENTRAL WISCONSIN
SHOULD RISE TO VFR STATUS DURING THE AFTERNOON. NOT MUCH HOPE FOR
THE BKN CONDITIONS TO CLEAR UNTIL LATE TONIGHT WHEN THE LOW LEVEL
RIDGE AXIS APPROACHES. ON THE WEST SIDE OF THIS RIDGE AXIS...DRIER
AIR WILL PUSH ACROSS THE STATE LATE TONIGHT THROUGH THE
MORNING...WHICH WILL END THE LAKE EFFECT SNOW SHOWERS...AND BRING
CLEARING SKIES. STRENGTHENING SOUTHWEST WINDS WILL BRING LLWS INTO
THE REGION BY LATE TOMORROW AFTERNOON AND EVENING.
&&
.MARINE...
ISSUED AT 258 PM CDT THU OCT 24 2013
SOUTHWEST WINDS WILL BE QUICKLY INCREASING FRIDAY AFTERNOON WITH
GALES POSSIBLE FRIDAY EVENING THROUGH EARLY SATURDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC
MARINE.........RDM