Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/20/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1134 AM MDT FRI OCT 18 2013
.UPDATE...
ISSUED AT 732 AM MDT FRI OCT 18 2013
UPDATED FRONT END OF FORECASTS TO REFLECT CURRENT OBSERVATIONS AND
TRENDS. NO MAJOR CHANGES TO FORECAST AT THIS TIME. LW
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 527 AM MDT FRI OCT 18 2013
...HIT AND RUN STORM ON THE WAY...
IT`S ON OUR DOORSTEP. THE SHORTWAVE THAT HAS BEEN HEADED OUR WAY IS
ABOUT TO ARRIVE. MULTIPLE LATE NIGHT TWEETS INDICATE SNOW HAS
SPREAD QUICKLY SOUTH ACROSS THE NORTHERN FRONT RANGE URBAN CORRIDOR
AND NORTHEAST PLAINS THIS MORNING. RADAR AND SURFACE REPORTS
INDICATE THAT SNOW HAS ALREADY SPREAD INTO THE CENTRAL
MOUNTAINS...INCLUDING LEADVILLE AND MONARCH PASS...AND IT IS JUST
NOW CROSSING THE PALMER DIVIDE INTO NORTHERN TELLER AND NORTHERN EL
PASO COUNTIES.
ALL FORECAST MODELS AGREE THAT SNOW WILL MOVE INTO TELLER AND EL
PASO COUNTIES THIS MORNING...WITH A MIXTURE OF RAIN AND SNOW SHOWERS
SPREADING SOUTH ACROSS THE REST OF THE EASTERN MOUNTAINS AND PLAINS.
THE GFS...AND TO A LESSER EXTENT...THE NAM HAVE BEEN GRADUALLY
TRENDING BACK TOWARD BETTER CHANCES FOR PRECIPITATION OVER THE
EASTERN MOUNTAINS AND PLAINS THAN THEY WERE 24 HOURS AGO.
ADDITIONALLY...SHORT RANGE FORECASTS OFF OF THE HIGH RESOLUTION
MODELS...INCLUDING THE HRRR AND THE WRF...ALSO SHOW AT LEAST SOME
PRECIPITATION SPREADING SOUTH ACROSS MOST OF THE EASTERN MOUNTAINS
AND PLAINS THIS MORNING. NONE OF THE MODELS HAVE ANYTHING VERY
HEAVY...BUT THEY DO HAVE SOME LIGHT TO LOCALLY MODERATE AMOUNTS.
RIGHT NOW...BEST BET IS FOR 1 TO 3 INCHES OF SNOW OVER THE CENTRAL
MOUNTAINS AND PIKES PEAK...LOCAL 1 TO 2 INCHES AMOUNTS ACROSS TELLER
AND EL PASO COUNTIES...AND GENERALLY AN INCH OR LESS ACROSS THE REST
OF THE EASTERN MOUNTAINS AND PLAINS. PRECIP BELOW 5500 FEET WILL
PROBABLY COME AS A MIXTURE OF RAIN AND SNOW SHOWERS...WHICH SHOULD
HELP TO LIMIT ACCUMULATIONS. ELEVATIONS ABOVE 5500 FEET WILL SEE
MOSTLY SNOW AND THE BEST CHANCES FOR ACCUMULATION.
SECOND ONLY TO THE PIKES PEAK REGION...THE FAR EASTERN PLAINS ALONG
THE KANSAS BORDER WILL SEE SOME OF THE BETTER ODDS FOR PRECIPITATION
TODAY. LIGHT SNOW IS ALREADY FALLING AT BURLINGTON AND RADAR SHOWS
DEVELOPING PRECIPITATION OVER NORTHEAST KIOWA COUNTY AT THIS TIME.
THIS DEVELOPMENT SHOULD CONTINUE SOUTHWARD THROUGH THE MORNING INTO
THE EARLY AFTERNOON HOURS. TEMPERATURES WILL BE A BIT BORDERLINE
FOR MUCH IN THE WAY OF SNOW ACCUMULATION...BUT COULD BE SOME SPOTTY
LIGHT AMOUNTS...ESPECIALLY ON GRASSY AREAS.
EVERYTHING SHIFTS EAST OF THE AREA AFTER ABOUT 2 OR 3 IN THE
AFTERNOON...SETTING THE STAGE FOR ANOTHER COLD NIGHT ACROSS SOUTHERN
COLORADO. A FREEZE WATCH REMAINS IN EFFECT FOR A LARGE PART OF
SOUTHEAST COLORADO FOR TONIGHT. LW
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 527 AM MDT FRI OCT 18 2013
NOT MANY METEOROLOGICAL LONGER TERM ADJUSTMENTS NEEDED FROM
EARLIER FORECAST THINKING AS A GENERALLY DRY AND MILD LONGER
TERM PATTERN IS EXPECTED TO DEVELOP OVER THE FORECAST DISTRICT.
FROM SATURDAY INTO THURSDAY...LATER COMPUTER SIMULATIONS CONTINUE
TO SUGGEST THAT A GENERALLY DRY AND MILD NORTHWESTERLY TO
NORTHERLY UPPER FLOW PATTERN WILL BE NOTED OVER THE CWFA THANKS TO
AN UPPER RIDGING PATTERN BUILDING OVER THE WESTERN UNITED STATES
DURING THIS TIME-FRAME.
AT THIS TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SHOWER
ACTIVITY DURING THE LONGER TERM OVER THE FORECAST DISTRICT WILL
OCCUR FROM LATER SUNDAY INTO MONDAY...ESPECIALLY OVER NORTHERN
SECTIONS AS AN UPPER DISTURBANCE INTERACTS WITH A SURFACE
NORTHERLY TO NORTHEASTERLY SURGE.
MAXIMUM AND MINIMUM TEMPERATURES DURING THE LONGER TERM SHOULD
BASICALLY RUN NEAR TO A FEW DEGREES ABOVE LATE OCTOBER
CLIMATOLOGICAL AVERAGES...ALTHOUGH TEMPERATURES BELOW SEASONAL
AVERAGES ARE ANTICIPATED MONDAY IN WAKE OF NORTHERLY/NORTHEASTERLY
SURGE AND UPPER DISTURBANCE. FINALLY...LOW-GRADE GRADIENT WINDS
ARE STILL ANTICIPATED OVER THE MAJORITY OF THE FORECAST DISTRICT
DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1130 AM MDT FRI OCT 18 2013
VFR CONDITIONS ARE EXPECTED THE REST OF THE DAY AT KCOS AND INTO
SATURDAY MORNING...ALTHOUGH SOME SCATTERED LOW CLOUDS WILL STILL
BE IN THE VCNTY THIS AFTERNOON. IFR CONDITIONS AT KPUB WILL
TRANSITION TO VFR AS THE CLOUD COVER DECREASE THIS AFTERNOON. KALS
WILL CONTINUE TO HAVE VFR CONDITIONS THROUGH SATURDAY
MORNING...WITH SOME GUSTY NW WINDS EXPECTED TO CONTINUE THROUGH
THE AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
COZ083-086-089-093>099.
&&
$$
UPDATE...LW
AVIATION...28
AREA FORECAST DISCUSSION
NWS PUEBLO CO
734 AM MDT FRI OCT 18 2013
.UPDATE...
ISSUED AT 732 AM MDT FRI OCT 18 2013
UPDATED FRONT END OF FORECASTS TO REFLECT CURRENT OBSERVATIONS AND
TRENDS. NO MAJOR CHANGES TO FORECAST AT THIS TIME. LW
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 527 AM MDT FRI OCT 18 2013
...HIT AND RUN STORM ON THE WAY...
IT`S ON OUR DOORSTEP. THE SHORTWAVE THAT HAS BEEN HEADED OUR WAY IS
ABOUT TO ARRIVE. MULTIPLE LATE NIGHT TWEETS INDICATE SNOW HAS
SPREAD QUICKLY SOUTH ACROSS THE NORTHERN FRONT RANGE URBAN CORRIDOR
AND NORTHEAST PLAINS THIS MORNING. RADAR AND SURFACE REPORTS
INDICATE THAT SNOW HAS ALREADY SPREAD INTO THE CENTRAL
MOUNTAINS...INCLUDING LEADVILLE AND MONARCH PASS...AND IT IS JUST
NOW CROSSING THE PALMER DIVIDE INTO NORTHERN TELLER AND NORTHERN EL
PASO COUNTIES.
ALL FORECAST MODELS AGREE THAT SNOW WILL MOVE INTO TELLER AND EL
PASO COUNTIES THIS MORNING...WITH A MIXTURE OF RAIN AND SNOW SHOWERS
SPREADING SOUTH ACROSS THE REST OF THE EASTERN MOUNTAINS AND PLAINS.
THE GFS...AND TO A LESSER EXTENT...THE NAM HAVE BEEN GRADUALLY
TRENDING BACK TOWARD BETTER CHANCES FOR PRECIPITATION OVER THE
EASTERN MOUNTAINS AND PLAINS THAN THEY WERE 24 HOURS AGO.
ADDITIONALLY...SHORT RANGE FORECASTS OFF OF THE HIGH RESOLUTION
MODELS...INCLUDING THE HRRR AND THE WRF...ALSO SHOW AT LEAST SOME
PRECIPITATION SPREADING SOUTH ACROSS MOST OF THE EASTERN MOUNTAINS
AND PLAINS THIS MORNING. NONE OF THE MODELS HAVE ANYTHING VERY
HEAVY...BUT THEY DO HAVE SOME LIGHT TO LOCALLY MODERATE AMOUNTS.
RIGHT NOW...BEST BET IS FOR 1 TO 3 INCHES OF SNOW OVER THE CENTRAL
MOUNTAINS AND PIKES PEAK...LOCAL 1 TO 2 INCHES AMOUNTS ACROSS TELLER
AND EL PASO COUNTIES...AND GENERALLY AN INCH OR LESS ACROSS THE REST
OF THE EASTERN MOUNTAINS AND PLAINS. PRECIP BELOW 5500 FEET WILL
PROBABLY COME AS A MIXTURE OF RAIN AND SNOW SHOWERS...WHICH SHOULD
HELP TO LIMIT ACCUMULATIONS. ELEVATIONS ABOVE 5500 FEET WILL SEE
MOSTLY SNOW AND THE BEST CHANCES FOR ACCUMULATION.
SECOND ONLY TO THE PIKES PEAK REGION...THE FAR EASTERN PLAINS ALONG
THE KANSAS BORDER WILL SEE SOME OF THE BETTER ODDS FOR PRECIPITATION
TODAY. LIGHT SNOW IS ALREADY FALLING AT BURLINGTON AND RADAR SHOWS
DEVELOPING PRECIPITATION OVER NORTHEAST KIOWA COUNTY AT THIS TIME.
THIS DEVELOPMENT SHOULD CONTINUE SOUTHWARD THROUGH THE MORNING INTO
THE EARLY AFTERNOON HOURS. TEMPERATURES WILL BE A BIT BORDERLINE
FOR MUCH IN THE WAY OF SNOW ACCUMULATION...BUT COULD BE SOME SPOTTY
LIGHT AMOUNTS...ESPECIALLY ON GRASSY AREAS.
EVERYTHING SHIFTS EAST OF THE AREA AFTER ABOUT 2 OR 3 IN THE
AFTERNOON...SETTING THE STAGE FOR ANOTHER COLD NIGHT ACROSS SOUTHERN
COLORADO. A FREEZE WATCH REMAINS IN EFFECT FOR A LARGE PART OF
SOUTHEAST COLORADO FOR TONIGHT. LW
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 527 AM MDT FRI OCT 18 2013
NOT MANY METEOROLOGICAL LONGER TERM ADJUSTMENTS NEEDED FROM
EARLIER FORECAST THINKING AS A GENERALLY DRY AND MILD LONGER
TERM PATTERN IS EXPECTED TO DEVELOP OVER THE FORECAST DISTRICT.
FROM SATURDAY INTO THURSDAY...LATER COMPUTER SIMULATIONS CONTINUE
TO SUGGEST THAT A GENERALLY DRY AND MILD NORTHWESTERLY TO
NORTHERLY UPPER FLOW PATTERN WILL BE NOTED OVER THE CWFA THANKS TO
AN UPPER RIDGING PATTERN BUILDING OVER THE WESTERN UNITED STATES
DURING THIS TIME-FRAME.
AT THIS TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SHOWER
ACTIVITY DURING THE LONGER TERM OVER THE FORECAST DISTRICT WILL
OCCUR FROM LATER SUNDAY INTO MONDAY...ESPECIALLY OVER NORTHERN
SECTIONS AS AN UPPER DISTURBANCE INTERACTS WITH A SURFACE
NORTHERLY TO NORTHEASTERLY SURGE.
MAXIMUM AND MINIMUM TEMPERATURES DURING THE LONGER TERM SHOULD
BASICALLY RUN NEAR TO A FEW DEGREES ABOVE LATE OCTOBER
CLIMATOLOGICAL AVERAGES...ALTHOUGH TEMPERATURES BELOW SEASONAL
AVERAGES ARE ANTICIPATED MONDAY IN WAKE OF NORTHERLY/NORTHEASTERLY
SURGE AND UPPER DISTURBANCE. FINALLY...LOW-GRADE GRADIENT WINDS
ARE STILL ANTICIPATED OVER THE MAJORITY OF THE FORECAST DISTRICT
DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 527 AM MDT FRI OCT 18 2013
FALL STORM SYSTEM WILL MOVE THROUGH CENTRAL AND EASTERN COLORADO
THROUGH EARLY AFTERNOON...AND THEN SHIFT EAST OF THE AREA AFTER
ABOUT 21Z. STORM SYSTEM WILL BRING SNOW SHOWERS TO THE CENTRAL
MOUNTAINS AND PIKES PEAK REGION 12Z-18Z...WITH ACTIVITY LINGERING
OVER THE EASTERN PLAINS AS LATE AS 21Z. AREAS OF MVFR/IFR/LIFR
CONDITIONS WILL BE POSSIBLE IN CLOUDS AND PRECIPITATION. THIS
INCLUDES THE KCOS TAF...AND WITH LESS CERTAINTY...THE KPUB TAF.
CONDITIONS WILL LIKELY RETURN TO VFR AT THESE 2 SITES...ROUGHLY
16Z-18Z...AS THE SYSTEM SHIFTS EAST OF THE AREA. KALS SHOULD BE
WEST OF THE ACTION WITH THIS EVENT...AND REMAIN VFR FOR THE
DURATION. THIS GOES FOR THE BULK OF THE SAN LUIS VALLEY AND
SOUTHWEST MOUNTAIN AREAS...WHERE ONLY SOME SPOTTY LIGHT RAIN AND
SNOW SHOWERS ARE EXPECTED WITH THIS PARTICULAR STORM. LW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
COZ083-086-089-093>099.
&&
$$
UPDATE...LW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
533 AM MDT FRI OCT 18 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 527 AM MDT FRI OCT 18 2013
...HIT AND RUN STORM ON THE WAY...
IT`S ON OUR DOORSTEP. THE SHORTWAVE THAT HAS BEEN HEADED OUR WAY IS
ABOUT TO ARRIVE. MULTIPLE LATE NIGHT TWEETS INDICATE SNOW HAS
SPREAD QUICKLY SOUTH ACROSS THE NORTHERN FRONT RANGE URBAN CORRIDOR
AND NORTHEAST PLAINS THIS MORNING. RADAR AND SURFACE REPORTS
INDICATE THAT SNOW HAS ALREADY SPREAD INTO THE CENTRAL
MOUNTAINS...INCLUDING LEADVILLE AND MONARCH PASS...AND IT IS JUST
NOW CROSSING THE PALMER DIVIDE INTO NORTHERN TELLER AND NORTHERN EL
PASO COUNTIES.
ALL FORECAST MODELS AGREE THAT SNOW WILL MOVE INTO TELLER AND EL
PASO COUNTIES THIS MORNING...WITH A MIXTURE OF RAIN AND SNOW SHOWERS
SPREADING SOUTH ACROSS THE REST OF THE EASTERN MOUNTAINS AND PLAINS.
THE GFS...AND TO A LESSER EXTENT...THE NAM HAVE BEEN GRADUALLY
TRENDING BACK TOWARD BETTER CHANCES FOR PRECIPITATION OVER THE
EASTERN MOUNTAINS AND PLAINS THAN THEY WERE 24 HOURS AGO.
ADDITIONALLY...SHORT RANGE FORECASTS OFF OF THE HIGH RESOLUTION
MODELS...INCLUDING THE HRRR AND THE WRF...ALSO SHOW AT LEAST SOME
PRECIPITATION SPREADING SOUTH ACROSS MOST OF THE EASTERN MOUNTAINS
AND PLAINS THIS MORNING. NONE OF THE MODELS HAVE ANYTHING VERY
HEAVY...BUT THEY DO HAVE SOME LIGHT TO LOCALLY MODERATE AMOUNTS.
RIGHT NOW...BEST BET IS FOR 1 TO 3 INCHES OF SNOW OVER THE CENTRAL
MOUNTAINS AND PIKES PEAK...LOCAL 1 TO 2 INCHES AMOUNTS ACROSS TELLER
AND EL PASO COUNTIES...AND GENERALLY AN INCH OR LESS ACROSS THE REST
OF THE EASTERN MOUNTAINS AND PLAINS. PRECIP BELOW 5500 FEET WILL
PROBABLY COME AS A MIXTURE OF RAIN AND SNOW SHOWERS...WHICH SHOULD
HELP TO LIMIT ACCUMULATIONS. ELEVATIONS ABOVE 5500 FEET WILL SEE
MOSTLY SNOW AND THE BEST CHANCES FOR ACCUMULATION.
SECOND ONLY TO THE PIKES PEAK REGION...THE FAR EASTERN PLAINS ALONG
THE KANSAS BORDER WILL SEE SOME OF THE BETTER ODDS FOR PRECIPITATION
TODAY. LIGHT SNOW IS ALREADY FALLING AT BURLINGTON AND RADAR SHOWS
DEVELOPING PRECIPITATION OVER NORTHEAST KIOWA COUNTY AT THIS TIME.
THIS DEVELOPMENT SHOULD CONTINUE SOUTHWARD THROUGH THE MORNING INTO
THE EARLY AFTERNOON HOURS. TEMPERATURES WILL BE A BIT BORDERLINE
FOR MUCH IN THE WAY OF SNOW ACCUMULATION...BUT COULD BE SOME SPOTTY
LIGHT AMOUNTS...ESPECIALLY ON GRASSY AREAS.
EVERYTHING SHIFTS EAST OF THE AREA AFTER ABOUT 2 OR 3 IN THE
AFTERNOON...SETTING THE STAGE FOR ANOTHER COLD NIGHT ACROSS SOUTHERN
COLORADO. A FREEZE WATCH REMAINS IN EFFECT FOR A LARGE PART OF
SOUTHEAST COLORADO FOR TONIGHT. LW
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 527 AM MDT FRI OCT 18 2013
NOT MANY METEOROLOGICAL LONGER TERM ADJUSTMENTS NEEDED FROM
EARLIER FORECAST THINKING AS A GENERALLY DRY AND MILD LONGER
TERM PATTERN IS EXPECTED TO DEVELOP OVER THE FORECAST DISTRICT.
FROM SATURDAY INTO THURSDAY...LATER COMPUTER SIMULATIONS CONTINUE
TO SUGGEST THAT A GENERALLY DRY AND MILD NORTHWESTERLY TO
NORTHERLY UPPER FLOW PATTERN WILL BE NOTED OVER THE CWFA THANKS TO
AN UPPER RIDGING PATTERN BUILDING OVER THE WESTERN UNITED STATES
DURING THIS TIME-FRAME.
AT THIS TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SHOWER
ACTIVITY DURING THE LONGER TERM OVER THE FORECAST DISTRICT WILL
OCCUR FROM LATER SUNDAY INTO MONDAY...ESPECIALLY OVER NORTHERN
SECTIONS AS AN UPPER DISTURBANCE INTERACTS WITH A SURFACE
NORTHERLY TO NORTHEASTERLY SURGE.
MAXIMUM AND MINIMUM TEMPERATURES DURING THE LONGER TERM SHOULD
BASICALLY RUN NEAR TO A FEW DEGREES ABOVE LATE OCTOBER
CLIMATOLOGICAL AVERAGES...ALTHOUGH TEMPERATURES BELOW SEASONAL
AVERAGES ARE ANTICIPATED MONDAY IN WAKE OF NORTHERLY/NORTHEASTERLY
SURGE AND UPPER DISTURBANCE. FINALLY...LOW-GRADE GRADIENT WINDS
ARE STILL ANTICIPATED OVER THE MAJORITY OF THE FORECAST DISTRICT
DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 527 AM MDT FRI OCT 18 2013
FALL STORM SYSTEM WILL MOVE THROUGH CENTRAL AND EASTERN COLORADO
THROUGH EARLY AFTERNOON...AND THEN SHIFT EAST OF THE AREA AFTER
ABOUT 21Z. STORM SYSTEM WILL BRING SNOW SHOWERS TO THE CENTRAL
MOUNTAINS AND PIKES PEAK REGION 12Z-18Z...WITH ACTIVITY LINGERING
OVER THE EASTERN PLAINS AS LATE AS 21Z. AREAS OF MVFR/IFR/LIFR
CONDITIONS WILL BE POSSIBLE IN CLOUDS AND PRECIPITATION. THIS
INCLUDES THE KCOS TAF...AND WITH LESS CERTAINTY...THE KPUB TAF.
CONDITIONS WILL LIKELY RETURN TO VFR AT THESE 2 SITES...ROUGHLY
16Z-18Z...AS THE SYSTEM SHIFTS EAST OF THE AREA. KALS SHOULD BE
WEST OF THE ACTION WITH THIS EVENT...AND REMAIN VFR FOR THE
DURATION. THIS GOES FOR THE BULK OF THE SAN LUIS VALLEY AND
SOUTHWEST MOUNTAIN AREAS...WHERE ONLY SOME SPOTTY LIGHT RAIN AND
SNOW SHOWERS ARE EXPECTED WITH THIS PARTICULAR STORM. LW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
COZ083-086-089-093>099.
&&
$$
AREA FORECAST DISCUSSION
NWS TAUNTON MA
655 AM EDT FRI OCT 18 2013
.SYNOPSIS...
AFTER SHOWERS AND CLOUDS CLEAR OUT EARLY THIS MORNING DRY WEATHER
RETURNS INTO EARLY NEXT WEEK...OTHER THAN A FEW SHOWERS POSSIBLE
SATURDAY NIGHT. UNSEASONABLY CHILLY WEATHER FOR LATE OCTOBER WILL
ARRIVE BY LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7 AM UPDATE...
COLD FRONT IS MOVING OFFSHORE ALONG THE EAST MASS COAST. SOME
LINGERING CLOUDS IN RI AND EASTERN MASS BUT MOSTLY OVER THE CAPE
AND ISLANDS. THESE CLOUDS SHOULD MOVE OFFSHORE THIS MORNING.
ANOTHER AREA OF CLOUDS MOVING FROM NEW YORK STATE INTO WESTERN
MASS AND VERMONT...AND WILL REACH PORTIONS OF CT AND SOUTHWEST NH
THIS MORNING. EXPECT THESE CLOUDS TO DIMINISH DURING THE MORNING.
FORECAST TEMPS AND DEWPTS WERE ABOUT 3F TOO COOL AT 6 AM. WE
ADJUSTED THEM HIGHER WITH HELP FROM THE HRRR FIELDS. NO CHANGE TO
FORECAST HIGH TEMPS AT THIS TIME.
PREVIOUS DISCUSSION...
GIVEN SKIES SHOULD TEND TOWARD SKC EVERYWHERE NOT LONG AFTER
SUNRISE...MIXING TO H85 IS EXPECTED AS A RIDGE OF HIGH PRES
APPROACHES FROM THE SW. TEMPS AT H85 AVERAGE AROUND +5C...SO
EXPECT ANOTHER MILD MID OCTOBER DAY WITH HIGH TEMPS IN THE UPPER
60S AND LOWER 70S. MAY FEEL A BIT COOLER HOWEVER...AS BRISK W FLOW
DEVELOPS. BL MIXING SHOULD BE ABLE TO TAP A 20-30 KT LLJ...SO WIND
GUSTS OF 20-30 MPH ARE POSSIBLE THROUGHOUT THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
RIDGE OF HIGH PRES BOTH AT THE SFC AND ALOFT WILL GRADUALLY CREST
OVER THE REGION DURING THE OVERNIGHT HOURS. DRY SOUNDINGS SUGGEST
MAINLY CLEAR TO PARTLY CLOUDY SKIES ARE A GOOD BET FOR THE
OVERNIGHT HOURS. MASS FIELDS ALSO SUPPORT A RAPIDLY SLACKENING PRES
GRADIENT AFTER 00Z...SO DO EXPECT A DECENT SETUP FOR OVERNIGHT
RADIATIONAL COOLING. THEREFORE...DESPITE WARM DAY TEMPS
TODAY...MINS ARE LIKELY TO DIP INTO THE LOW TO MID 40S AT SEVERAL
LOCATIONS /WARMER...CLOSER TO 50 IN URBAN AREAS/. WHILE THESE WILL
LIKELY FEEL COOL IN RELATION TO THE LAST COUPLE OF NIGHTS...THEY
ARE FAIRLY CLOSE TO NORMAL FOR THIS TIME OF YEAR.
SAT...
A SEASONABLY COOL START WITH A FAIR AMOUNT OF SUNSHINE WILL
GRADUALLY GIVE WAY TO INCREASING CLOUDINESS FROM BOTH THE S AND
THE W AS TWO SEPARATE SHORTWAVE APPROACH FROM EACH OF THESE
DIRECTIONS. ATTM...SAT SHOULD REMAIN MOSTLY DRY AS THESE WAVES
ARE UNLIKELY TO PHASE AND HIGH PRES RIDGING REMAINS IN CONTROL
WITH DECENT SUBSIDENCE ALOFT. MIXING LOOKS TO REACH CLOSE TO H85
AGAIN SUN...WITH TEMPS AT THIS LVL SIMILAR TO FRI. HOWEVER...THE
INCREASE IN LATE DAY CLOUDS AND A COOLER START MAY MITIGATE
DIURNAL TEMP INCREASE A BIT. THEREFORE...HAVE HIGHS A SHADE COOLER
THAN FRI. MAINLY MID TO UPPER 60S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
BIG PICTURE... THE PATTERN FOR NEXT WEEK IS DOMINATED BY
MIDCONTINENT UPPER TROUGH WHICH SHIFTS EASTWARD MIDWEEK. ONE
SHORTWAVE EJECTS FROM THE TROUGH AND MOVES ACROSS NEW ENGLAND
SATURDAY NIGHT/SUNDAY MORNING. A SECOND SHORTWAVE MOVES SOUTH FROM
THE CANADIAN ARCTIC AND THEN DIGS INTO THE BASE OF THE TROUGH MONDAY
NIGHT...THEN EJECTS THROUGH NEW ENGLAND TUESDAY/TUESDAY NIGHT. THIS
PATTERN FAVORS COLDER THAN NORMAL TEMPERATURES ESPECIALLY WEDNESDAY-
THURSDAY.
THE DAILIES...
SATURDAY NIGHT... THE FIRST SHORTWAVE NOTED ABOVE PUSHES A COLD
FRONT ACROSS THE REGION. BOTH GFS AND ECMWF SHOW A STRONG 140 KNOT
UPPER JET MOVING FROM THE OHIO VALLEY ACROSS NEW ENGLAND. NORTHERN
NEW ENGLAND IS FAVORED FOR UPPER VENTING IN THE LEFT EXIT REGION OF
THIS JET. THE TRAILING RIGHT ENTRANCE REGION OF THE JET MOVES ACROSS
SOUTHERN NEW ENGLAND DURING THE LATTER PART OF THE NIGHT. MODEL
CROSS SECTIONS ALSO SHOW A DEEP BUT THREADY COLUMN OF MOISTURE
LEADING THE COLD FRONT WITH A WEAK 1-2 MICROBAR/SEC LIFT. THIS
ALLOWS CONFIDENCE OF SCATTERED SHOWERS/CHANCE POPS WITH THE FRONTAL
PASSAGE BUT WITH HIGHER VALUES IN UPSTATE NY/VERMONT/NORTHERN NEW
HAMPSHIRE. THIS PATTERN BEARS RESEMBLANCE TO THE FRONTAL PASSAGE
OCCURRING AS THIS IS WRITTEN. TEMPS ARE A BLEND OF MOS VALUES.
SUNDAY... COLD ADVECTION ON WEST TO NORTHWEST WINDS WILL BRING
DRYING AND CLEARING SKIES. THE PASSING SHORTWAVE HAS A NOTICEABLE
COLD POOL THAT MOVES ACROSS NORTHERN NEW ENGLAND...AND WHICH COULD
CLIP OUR AREA ESPECIALLY NORTH OF THE MASS PIKE. MOISTURE FIELDS
SHOW 70+% RELATIVE HUMIDITY IN THE 800-900 MB LAYER. THE MOISTURE
AND DESTABILIZATION SHOULD LEAD TO SOME CLOUD DEVELOPMENT DURING THE
DAY. TEMPS ALOFT AT THE TOP OF THE MIXED LAYER SHOULD SUPPORT MAX
SURFACE TEMPS IN THE UPPER 50S TO MID 60S. WINDS IN THIS MIXED
LAYER ARE FORECAST AT 15-20 KNOTS WHICH IS MUCH HIGHER THAN MODEL
WIND GUST FORECASTS...WE BUMPED GUSTS UP ABOUT 5-8KTS TO REFLECT
THIS WIND POTENTIAL.
SUNDAY NIGHT...HIGH PRESSURE BUILDS IN FROM THE SOUTHWEST. THIS
SHOULD PROVIDE MOSTLY CLEAR SKIES AND LIGHT WINDS. DEWPOINTS WILL
BE IN THE MID 30S...SO MIN TEMPS SHOULD REACH THIS LEVEL ACROSS A
WIDE AREA. POTENTIAL FOR WIDESPREAD FROST.
MONDAY THROUGH THURSDAY... HIGH PRESSURE IN CONTROL MONDAY WITH DRY
COOL WEATHER. THE SECOND UPPER SHORTWAVE PUSHES A COLD FRONT ACROSS
NEW ENGLAND TUESDAY OR TUESDAY EVENING. UPPER SUPPORT IS SUFFICIENT
FOR SHOWERS BUT MOISTURE IS LIMITED. SO WE HAVE LOW-END CHANCE POPS.
THE UPPER TROUGH AND COLD POOL WILL LINGER IN THE VICINITY WEDNESDAY
AND THURSDAY WHICH MAY LEAD TO MORE SKY COVER THAN IS CURRENTLY IN
THE FORECAST. IT WILL ALSO MEAN COLDER TEMPS THAN ON MONDAY AND
TUESDAY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY/...
HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN EXACT TIMING OF
IMPROVEMENT THIS MORNING.
LINGERING CIGS 500-1000 FEET OVER THE CAPE AND ISLANDS AT SUNRISE.
BUT THE CLEARING LINE IS PROGRESSING EAST AND SHOULD MOVE OFFSHORE
BY 8 AM. A SECOND BATCH OF LOW CLOUDS OVER THE BERKSHIRES IS
MOVING INTO THE CT VALLEY. BUT EXPECT THE DOWNHILL MOTION TO WARM
THE AIR AND EVAPORATE THE LOWER PORTIONS OF THESE CLOUDS...SO
EXPECT VFR CIGS OVER THE CT VALLEY THIS MORNING. THESE CLOUDS
SHOULD BREAK AS THEY MOVE EAST. VFR THE REMAINDER OF THE DAY.
PATCHY FOG POSSIBLE TONIGHT IN THE USUAL PROTECTED VALLEYS. CIGS
AT OR BELOW 500 FEET IN FOG AREAS AND VSBYS 1 MILE OR LESS.
INCREASING CLOUDS SATURDAY AS A COLD FRONT APPROACHES FROM THE
GREAT LAKES. BUT MOSTLY HIGH-BASED CLOUDS THROUGH THE DAY. VFR
CONDITIONS EXPECTED.
WEST WINDS WILL DRAW GUSTS OF 20-30 KT TO THE
SURFACE...DIMINISHING THIS EVENING. WEAKER WIND TONIGHT AND SAT.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF TRENDS...WEST WINDS GUST
20-30 KT AT TIMES TODAY...ABOUT 10 TO 20 DEGREES EITHER SIDE OF
270.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS...WEST WINDS GUST UP TO
20-25 KT AT TIMES TODAY.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
MODERATE CONFIDENCE.
COLD FRONTS WILL MOVE ACROSS THE REGION ON SATURDAY NIGHT AND
TUESDAY WITH POTENTIAL MVFR/IFR CIGS/VSBYS IN SHOWERS EACH TIME.
OTHERWISE VFR THROUGH THE PERIOD. WEST TO NORTHWEST WINDS SUNDAY
MAY GUST AROUND 20 KNOTS. SOUTHWEST WINDS TUESDAY MAY GUST 20-25
KNOTS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE.
THROUGH TONIGHT...
BUILDING SEAS WILL CONTINUE RISE THROUGH MID AFTERNOON BUT THEN
BEGIN TO DECLINE UNDER WESTERLY BREEZES. SEAS WILL DROP BELOW 5 FT
ON OCEAN WATERS LATE TONIGHT. OTHERWISE...W WINDS INCREASE DURING
THE DAYLIGHT HOURS TODAY...WITH SOME GUSTS 25-30 KT
POSSIBLE...ESPECIALLY NEAR SHORES. SMALL CRAFT ADVISORIES CONTINUE
THROUGH THE DAY TODAY OVER ALL WATERS. THEN DROP OFF DURING THE
OVERNIGHT TONIGHT.
SATURDAY...
HIGH PRES OVER THE WATERS WILL LEAD TO GENERALLY QUIET BOATING
WEATHER...SEAS WILL REMAIN BELOW 5 FT AND SW WINDS GUST UP TO 15
KT.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
MODERATE CONFIDENCE
SATURDAY NIGHT-SUNDAY...A COLD FRONT MOVES ACROSS THE WATERS
SATURDAY NIGHT. WEST TO NORTHWEST WINDS TRAILING THE FRONT MAY GUST
TO 25 KNOTS ON SUNDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED.
MONDAY-TUESDAY...HIGH PRESSURE AND FAIR WEATHER MONDAY SHOULD KEEP
WINDS AND SEAS QUIET. AN APPROACHING COLD FRONT TUESDAY WILL BRING
SCATTERED SHOWERS. SOUTHWEST WINDS WILL INCREASE AHEAD OF THE FRONT
WITH GUSTS OF 25-30 KNOTS. THIS WILL BUILD SEAS WITH 5 TO 7 FOOT
HEIGHTS ON THE EXPOSED WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED
TUESDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
ANZ231>234-251.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS
EVENING FOR ANZ230-236.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT SATURDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...WTB/DOODY
NEAR TERM...WTB/DOODY
SHORT TERM...DOODY
LONG TERM...WTB
AVIATION...WTB/DOODY
MARINE...WTB/DOODY
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1015 PM EDT SAT OCT 19 2013
.SYNOPSIS...
DRYING WILL OCCUR BEHIND A COLD FRONT TONIGHT. HIGH PRESSURE WILL
DOMINATE SUNDAY INTO MONDAY. LOW PRESSURE WILL DEVELOP ON A
STALLED FRONTAL BOUNDARY OFFSHORE BY LATE MONDAY BRINGING ANOTHER
CHANCE FOR RAIN TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE LATEST ANALYSIS SHOWED DRY AIR ADVECTION. SCATTERED SHOWERS
AHEAD OF THE COLD FRONT HAVE SHIFTED EAST OF THE FORECAST AREA.
FURTHER DRYING WILL OCCUR BEHIND THE COLD FRONT DURING THE EARLY
MORNING HOURS. THERE MAY BE JUST ENOUGH MOISTURE FOR A FEW
ADDITIONAL SHOWERS AS THE COLD FRONT REACHES THE EAST PART OF THE
FORECAST AREA. THE HRRR INDICATES SHOWER COVERAGE INCREASING IN
THE LOWCOUNTRY. WE HAVE KEPT A SMALL SHOWER CHANCE IN THE EAST
PART OVERNIGHT. THE TEMPERATURE GUIDANCE MAY BE A LITTLE TOO COOL
BECAUSE OF MIXING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
DRY HIGH PRESSURE WILL BRING MORE SEASONABLE CONDITIONS TO THE
REGION. TEMPERATURES SHOULD BE CLOSE TO NORMAL WITH HIGHS IN THE
LOWER TO MIDDLE 70S. LOWS WILL BE BELOW NORMAL SUNDAY
NIGHT...FALLING INTO THE 40S IN MANY LOCATIONS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AN UPPER-LEVEL LOW OVER THE GREAT LAKES REGION WILL MOVE
NORTHEAST ACROSS EASTERN CANADA DURING THE EXTENDED PERIOD.
SURFACE HIGH PRESSURE WILL MOVE OFF THE EAST COAST MONDAY NIGHT AS
A COLD FRONT APPROACHES FROM THE WEST. ISENTROPIC LIFT/MOISTURE
FLUX WILL INCREASE FROM THE SOUTH DUE TO A STALLED FRONT ACROSS
THE GULF COAST STATES. ALSO FORCING WILL BE PROVIDED BY UPPER
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A STRENGTHENING JET.
THESE FACTORS WILL BRING A CHANCE OF SHOWERS TO THE FORECAST AREA
MONDAY NIGHT INTO TUESDAY. THE COLD FRONT WILL CROSS OUR AREA
BY LATE TUESDAY.
COOL AND DRY HIGH PRESSURE WILL RETURN WEDNESDAY THROUGH SATURDAY. EXPECT
BELOW NORMAL TEMPERATURES FOR THE LATTER HALF OF THE WEEK.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS.
A WEAK COLD FRONT WILL CROSS THE AREA AFTER 06Z TURNING WINDS MORE
NORTHERLY AND EVENTUALLY NORTHEASTERLY AFTER 12Z AS HIGH PRESSURE
BUILDS IN FROM THE NORTH. WESTERLY FLOW ABOVE THE SURFACE YIELDING
WEAK DOWNSLOPE COMPONENT WITH DRIER AIR WORKING IN SO DO NOT
EXPECT ANY RESTRICTIONS WITH THE FRONT OR POST FRONT. SHOWERS HAVE
ALL SHIFTED EAST OF THE AREA SO ONLY BROKEN MID AND HIGH CLOUDS
EXPECTED THROUGH THE PERIOD. LOW LEVEL JET OVERNIGHT WILL HELP
KEEP BOUNDARY LAYER MIXED PREVENTING FOG FORMATION. NORTHEAST
WINDS AROUND 5 TO 8 MPH AFTER 14Z.
EXTENDED AVIATION OUTLOOK...NO IMPACTS TO AVIATION EXPECTED
THROUGH MONDAY. A CHANCE OF SHOWERS AND ASSOCIATED RESTRICTIONS
TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
825 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. LOW PRESSURE
WILL DEVELOP ON A STALLED FRONTAL BOUNDARY OFFSHORE BY LATE MONDAY
BRINGING ANOTHER CHANCE FOR RAIN TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
CONVERGENCE ASSOCIATED WITH THE COLD FRONT AND A MID-LEVEL
SHORTWAVE TROUGH WERE HELPING TO SUPPORT A FEW SHOWERS IN THE EAST
PART OF THE FORECAST AREA. THE HRRR KEEPS SHOWERS IN THE EAST
PART FOR MUCH OF THE NIGHT. THE SPC WRF SHOWS ISOLATED SHOWERS
EXITING THE EAST PART BY MIDNIGHT. RADAR TRENDS SUPPORT THE FASTER
TIMING. EXPECT FURTHER DRYING BEHIND THE FRONT OVERNIGHT. THE
TEMPERATURE GUIDANCE MAY BE A LITTLE TOO COOL BECAUSE OF MIXING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
DRY HIGH PRESSURE WILL BRING MORE SEASONABLE CONDITIONS TO THE
REGION. TEMPERATURES SHOULD BE CLOSE TO NORMAL WITH HIGHS IN THE
LOWER TO MIDDLE 70S. LOWS WILL BE BELOW NORMAL SUNDAY
NIGHT...FALLING INTO THE 40S IN MANY LOCATIONS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AN UPPER-LEVEL LOW OVER THE GREAT LAKES REGION WILL MOVE
NORTHEAST ACROSS EASTERN CANADA DURING THE EXTENDED PERIOD.
SURFACE HIGH PRESSURE WILL MOVE OFF THE EAST COAST MONDAY NIGHT AS
A COLD FRONT APPROACHES FROM THE WEST. ISENTROPIC LIFT/MOISTURE
FLUX WILL INCREASE FROM THE SOUTH DUE TO A STALLED FRONT ACROSS
THE GULF COAST STATES. ALSO FORCING WILL BE PROVIDED BY UPPER
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A STRENGTHENING JET.
THESE FACTORS WILL BRING A CHANCE OF SHOWERS TO THE FORECAST AREA
MONDAY NIGHT INTO TUESDAY. THE COLD FRONT WILL CROSS OUR AREA
BY LATE TUESDAY.
COOL AND DRY HIGH PRESSURE WILL RETURN WEDNESDAY THROUGH SATURDAY. EXPECT
BELOW NORMAL TEMPERATURES FOR THE LATTER HALF OF THE WEEK.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS.
A WEAK COLD FRONT WILL CROSS THE AREA AFTER 06Z TURNING WINDS MORE
NORTHERLY AND EVENTUALLY NORTHEASTERLY AFTER 12Z AS HIGH PRESSURE
BUILDS IN FROM THE NORTH. WESTERLY FLOW ABOVE THE SURFACE YIELDING
WEAK DOWNSLOPE COMPONENT WITH DRIER AIR WORKING IN SO DO NOT
EXPECT ANY RESTRICTIONS WITH THE FRONT OR POST FRONT. SHOWERS HAVE
ALL SHIFTED EAST OF THE AREA SO ONLY BROKEN MID AND HIGH CLOUDS
EXPECTED THROUGH THE PERIOD. LOW LEVEL JET OVERNIGHT WILL HELP
KEEP BOUNDARY LAYER MIXED PREVENTING FOG FORMATION. NORTHEAST
WINDS AROUND 5 TO 8 MPH AFTER 14Z.
EXTENDED AVIATION OUTLOOK...NO IMPACTS TO AVIATION EXPECTED
THROUGH MONDAY. A CHANCE OF SHOWERS AND ASSOCIATED RESTRICTIONS
TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
745 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. LOW PRESSURE
WILL DEVELOP ON A STALLED FRONTAL BOUNDARY OFFSHORE BY LATE MONDAY
BRINGING ANOTHER CHANCE FOR RAIN TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
CONVERGENCE ASSOCIATED WITH THE COLD FRONT AND A MID-LEVEL
SHORTWAVE TROUGH WERE HELPING TO SUPPORT SCATTERED SHOWERS.
EXPECT COVERAGE WILL REMAIN SCATTERED BECAUSE OF LIMITED MOISTURE.
THE HRRR KEEPS SHOWERS IN THE EAST PART FOR MUCH OF THE NIGHT.
THE SPC WRF SHOWS ISOLATED SHOWERS EXITING THE EAST PART BY
MIDNIGHT. RADAR TRENDS SUPPORT THE FASTER TIMING. EXPECT FURTHER
DRYING BEHIND THE FRONT OVERNIGHT. THE TEMPERATURE GUIDANCE MAY BE
A LITTLE TOO COOL BECAUSE OF MIXING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
DRY HIGH PRESSURE WILL BRING MORE SEASONABLE CONDITIONS TO THE
REGION. TEMPERATURES SHOULD BE CLOSE TO NORMAL WITH HIGHS IN THE
LOWER TO MIDDLE 70S. LOWS WILL BE BELOW NORMAL SUNDAY
NIGHT...FALLING INTO THE 40S IN MANY LOCATIONS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AN UPPER-LEVEL LOW OVER THE GREAT LAKES REGION WILL MOVE
NORTHEAST ACROSS EASTERN CANADA DURING THE EXTENDED PERIOD.
SURFACE HIGH PRESSURE WILL MOVE OFF THE EAST COAST MONDAY NIGHT AS
A COLD FRONT APPROACHES FROM THE WEST. ISENTROPIC LIFT/MOISTURE
FLUX WILL INCREASE FROM THE SOUTH DUE TO A STALLED FRONT ACROSS
THE GULF COAST STATES. ALSO FORCING WILL BE PROVIDED BY UPPER
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A STRENGTHENING JET.
THESE FACTORS WILL BRING A CHANCE OF SHOWERS TO THE FORECAST AREA
MONDAY NIGHT INTO TUESDAY. THE COLD FRONT WILL CROSS OUR AREA
BY LATE TUESDAY.
COOL AND DRY HIGH PRESSURE WILL RETURN WEDNESDAY THROUGH SATURDAY. EXPECT
BELOW NORMAL TEMPERATURES FOR THE LATTER HALF OF THE WEEK.
&&
.AVIATION /00Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS.
A WEAK COLD FRONT WILL CROSS THE AREA AFTER 06Z TURNING WINDS MORE
NORTHERLY AND EVENTUALLY NORTHEASTERLY AFTER 12Z AS HIGH PRESSURE
BUILDS IN FROM THE NORTH. WESTERLY FLOW ABOVE THE SURFACE YIELDING
WEAK DOWNSLOPE COMPONENT WITH DRIER AIR WORKING IN SO DO NOT
EXPECT ANY RESTRICTIONS WITH THE FRONT OR POST FRONT. SHOWERS HAVE
ALL SHIFTED EAST OF THE AREA SO ONLY BROKEN MID AND HIGH CLOUDS
EXPECTED THROUGH THE PERIOD. LOW LEVEL JET OVERNIGHT WILL HELP
KEEP BOUNDARY LAYER MIXED PREVENTING FOG FORMATION. NORTHEAST
WINDS AROUND 5 TO 8 MPH AFTER 14Z.
EXTENDED AVIATION OUTLOOK...NO IMPACTS TO AVIATION EXPECTED
THROUGH MONDAY. A CHANCE OF SHOWERS AND ASSOCIATED RESTRICTIONS
TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1051 AM EDT FRI OCT 18 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE INTO THE AREA TODAY AND LINGER
TONIGHT...AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE FRONT. THE
FRONT WILL REMAIN POSITIONED ALONG THE SOUTHEAST COAST ON
SATURDAY...SHIFTING OFFSHORE SUNDAY AS HIGH PRESSURE BUILDS EARLY
NEXT WEEK. A WEAK WAVE OF LOW PRESSURE WILL MOVE NORTHEAST ALONG
THE REMNANT OFFSHORE FRONT THROUGH THE MIDDLE OF NEXT WEEK. MUCH
COOLER CANADIAN HIGH PRESSURE WILL MOVE IN FOR THE LATTER PART OF
THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST SURFACE ANALYSIS PLACES A TROUGH ALONG THE SOUTHEAST
COASTLINE THIS MORNING...WITH A WEAK FRONT HAVING PROGRESSED INTO
THE FORECAST AREA. MOISTURE CONVERGENCE ALONG THE FRONTAL ZONE HAS
ALLOWED A SWATH OF THICK CLOUD COVER TO SHIFT INTO THE REGION...AS
PRECIPITABLE WATER VALUES HAVE INCREASED TO AROUND 1.85 INCHES
ACCORDING TO THE CHARLESTON SOUNDING. LIMITED UPPER LEVEL SUPPORT
WITHIN SOME NEGATIVE VORTICITY ADVECTION HAS CONFINED SHOWER
ACTIVITY TO A NARROW LINE CURRENTLY STRETCHING FROM SOUTHERN
GEORGIA INTO CENTRAL SOUTH CAROLINA.
THE WEAK FRONT WILL REMAIN STALLED OVER THE FORECAST AREA DURING
THE DAYTIME HOURS AS IT BECOMES PARALLEL TO THE FLOW ALOFT AND
FEELS THE EFFECTS OF A BLOCKING RIDGE FAR TO THE EAST/SOUTHEAST.
DESPITE MOSTLY CLOUDY SKIES PREVAILING FOR MUCH OF THE
DAY...TEMPERATURES WILL RISE WELL ABOVE SEASONAL NORMALS DUE TO
PRE-FRONTAL COMPRESSION AND A MORE PERSISTENT WARM WESTERLY FLOW
REGIME AHEAD OF THE SLOWING FRONT. A SEABREEZE CIRCULATION WILL
ACTUALLY BECOME WELL-DEFINED AS A RESULT OF BOTH THESE WARMER
CONDITIONS AND THE WEAK PRESSURE PATTERN WITHIN THE SURFACE
TROUGH. THE MAIN QUESTION THEN BECOMES WHETHER INCREASED FORCING
PRODUCED BY THE COMBINED EFFECTS OF THE SEABREEZE...LINGERING
FRONT AND SURFACE TROUGH WILL BE SUFFICIENT TO SPREAD PRECIPITATION
COVERAGE ACROSS THE FORECAST AREA DURING THE NEXT SEVERAL HOURS.
SHORT RANGE MODEL SOLUTIONS VARY IN COVERAGE DETAILS AND FAVORED
LOCATIONS...YET THE GENERAL TREND IS FOR AT LEAST LIGHT SHOWER
ACTIVITY TO GENERALLY SHIFT EAST/NORTHEAST AS THE DAY
PROGRESSES...PERHAPS CONCENTRATING JUST INLAND OF THE COAST NEAR
THE SEABREEZE. ONGOING PRECIPITATION FORECAST APPEARS ON TRACK
WITH THIS SCENARIO...AND WILL LIKELY MAKE NO CHANGES WITH THE LATE
MORNING UPDATE. RAP MODEL FORECAST FOR THIS AFTERNOON HINTS AT A
SMALL AREA OF SLIGHTLY HIGHER INSTABILITY SLIPPING NORTH OF THE
ALTAMAHA RIVER IN GEORGIA...WHERE LESS CLOUD COVER CURRENTLY
PREVAILS THIS MORNING. THUS ISOLATED THUNDER COULD OCCUR GENERALLY
SOUTH OF INTERSTATE 16...ESPECIALLY WHERE AN INTERACTION WITH THE
SEABREEZE TAKES PLACE. HOWEVER...OVERALL RAINFALL AMOUNTS STILL
LOOK RATHER UNIMPRESSIVE IN THE 0.05 TO 0.15 INCH RANGE.
TONIGHT...A DEEP FEED OF SUB-TROPICAL MOISTURE WILL EXTEND ACROSS
THE SOUTHEAST STATES...RESULTING IN PRECIPITABLE WATER VALUES THAT
WILL CLIMB TO NEARLY 2 STANDARD DEVIATIONS ABOVE MID OCTOBER
LEVELS. THE COLD FRONT WILL INCH ITS WAY TOWARD THE
COAST...ALTHOUGH THIS WILL BE A LABORING PROCESS AS SHORT WAVE
ENERGY WILL ARRIVE FROM THE GULF AND TRIGGER THE DEVELOPMENT OF
WEAK LOW PRESSURE ALONG THE FRONT. WATER VAPOR SATELLITE IMAGERY
IS CLEARLY DEPICTING THE SHORT WAVE ENERGY AND FEED OF MOISTURE
FROM TEXAS AND OLD MEXICO. THE WAVE OF LOW PRESSURE WILL RIDE
NORTHEAST OVER THE EASTERN ZONES FROM ABOUT 03-09Z...BEFORE IT
LIFTS AWAY LATE. THIS WILL ALLOW FOR THE COLD FRONT TO FINALLY
SWING INTO THE NEARBY ATLANTIC BY 12Z SATURDAY. GIVEN BETTER
DYNAMICS ALOFT...HAVE INCREASED RAIN CHANCES INTO THE 30-60
PERCENT RANGE...GREATEST NEAR THE TRACK OF THE SURFACE WAVE OVER
EASTERN ZONES...MOST ESPECIALLY OVER CHARLESTON AND BERKELEY
COUNTIES. LOW TEMPERATURES WILL BE AT THE WARMEST LEVELS FOR THE
REMAINDER OF THE FORECAST PERIOD...DROPPING NO LOWER THAN THE
LOW/MID 60S INLAND...TO THE UPPER 60S TO AROUND 70 CLOSER TO THE
OCEAN.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY AND SATURDAY NIGHT...THE PERIOD BEGINS WITH MUCH OF THE
COUNTRY UNDER THE INFLUENCE OF A LONGWAVE MID/UPPER LEVEL TROUGH
CENTERED ALONG THE MS VALLEY. THE EMBEDDED SHORTWAVE WILL DAMPEN OUT
AS IT LIFTS TO THE NORTHEAST WITH THE FORECAST AREA REMAINING UNDER
SOUTHWEST FLOW ALOFT THROUGH THE PERIOD. A COLD FRONT WILL START THE
DAY IN THE VICINITY OF THE AREA...ROUGHLY ORIENTED ALONG THE
SOUTHEAST COASTLINE. THE FRONT WILL SHIFT EASTWARD THROUGH SATURDAY
NIGHT AS HIGH PRESSURE OVER THE SOUTHERN PLAINS BUILDS IN FROM THE
WEST. THE BEST TIME FOR PRECIP WILL BE SATURDAY MORNING ALONG THE SC
COASTLINE THANKS TO SOME LOW LEVEL ISENTROPIC LIFT AND THE PRESENCE
OF UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 130+ KT 300 MB
JET. THE TREND IS THEN FOR POPS TO DECREASE THROUGH THE DAY AS DRIER
AIR FILTERS IN AND THE FRONT SHIFTS OFFSHORE. I HAVE FAVORED POPS
ALONG THE COAST IN THE HIGH CHANCE RANGE WITH A SMALL AREA OF LIKELY
POPS FOR EASTERN BERKELEY AND CHARLESTON COUNTIES. TEMPS WILL BE
HELD DOWN THANKS TO PLENTIFUL CLOUDS AND MORNING PRECIP...KEEPING
HIGHS IN THE MID/UPPER 70S. OVERNIGHT...CLOUDS WILL GRADUALLY THIN
AND DECREASE IN COVERAGE WITH A PRIMARILY DRY FORECAST OVER LAND.
LOWS WILL FALL INTO THE UPPER 50S INLAND AND LOW 60S CLOSER TO THE
BEACHES.
SUNDAY THROUGH MONDAY...THE FLOW ALOFT WILL BECOME NEARLY ZONAL FOR
A TIME BEFORE STARTING TO AMPLIFY EARLY NEXT WEEK AS A DEEP CLOSED
LOW DIVES SOUTHWARD AND INTO THE GREAT LAKES REGION. HIGH PRESSURE
WILL EXPAND ACROSS THE REGION ON SUNDAY AND THEN SHIFT OFFSHORE
MONDAY. EXPECT A DRY AND TRANQUIL DAY ON SUNDAY. MONDAY WILL
GENERALLY BE QUIET AS WELL...THOUGH WITH THE HIGH SHIFTING OFFSHORE
THE REMNANT FRONT OVER THE ADJACENT WATERS WILL BEGIN TO SHIFT BACK
TOWARDS LAND. AS IT DOES SOME MOISTURE RETURN WILL SET UP AND WE MAY
EVEN SEE A FEW SHOWERS DEVELOPING ACROSS FAR SOUTHEAST GA NEAR THE
ALTAMAHA. SLIGHT CHANCE POPS TO CREEP IN FROM THE SOUTH...THOUGH
MUCH OF ANY ACTIVITY WILL BE LATE IN THE DAY. TEMPS WILL BE RIGHT
AROUND CLIMO WHICH MEANS MID/UPPER 70S IN MOST AREAS FOR HIGHS AND
LOW/MID 50S FOR LOWS.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
OVERALL CONFIDENCE IN THE LONG TERM PERIOD IS RELATIVELY GOOD. MOST
OF THE ACTIVITY IN THE PERIOD WILL BE EARLY ON...WITH THE LATTER
PORTION DOMINATED BY HIGH PRESSURE. THE AFOREMENTIONED REMNANT FRONT
WILL BE ORIENTED ALONG AND NEAR THE AREA MONDAY NIGHT INTO TUESDAY.
DEEP MOISTURE WILL INCREASE ACROSS THE REGION AND MUCH OF THE
FORCING WILL BE PROVIDED BY UPPER DIVERGENCE IN THE RIGHT ENTRANCE
REGION OF A STRENGTHENING JET THAT IS EXPECTED TO STRETCH FROM THE
SOUTHERN APPALACHIANS TO THE MID ATLANTIC. THE TIME PERIOD FOR THE
BEST CHANCES WILL OCCUR LATE MONDAY NIGHT AND INTO TUESDAY. POPS
HAVE BEEN KEPT IN THE HIGH CHANCE RANGE FOR NOW AND MAY NEED AN
UPWARD ADJUSTMENT IF THIS FORECAST SCENARIO CONTINUES TO PLAY OUT.
BY WEDNESDAY...EXPANSIVE CANADIAN HIGH PRESSURE WILL SINK SOUTHWARD
ACROSS THE PLAINS AND BEGIN TO BUILD INTO THE REGION. THIS WILL
BRING ABOUT CLEARING SKIES AND THE POTENTIAL FOR MUCH COOLER
TEMPERATURES. IN FACT...850 MB TEMPS ARE PROGGED TO FALL WELL INTO
THE SINGLE DIGITS AND BRING ABOUT THE COOLEST TEMPS OF THE SEASON
THUS FAR. IT IS WORTH NOTING THAT MODEL LOW LEVEL THICKNESS VALUES
WOULD ONLY SUPPORT LOW/MID 60S FOR HIGHS BY LATE IN THE WEEK.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
KCHS...A COLD FRONT WILL STALL IN THE VICINITY THROUGH
TONIGHT...AS A WAVE OF LOW PRESSURE RIDES NORTHEAST ALONG THE
FRONT. THIS WILL TRIGGER THE DEVELOPMENT OF SCATTERED SHRA WITH A
LOW-END CHANCE OF ISOLATED TSRA. ALTHOUGH PREFER TO KEEP FLIGHT
RESTRICTIONS OUT OF THE FORECAST AT THIS POINT DUE TO
TIMING/COVERAGE UNCERTAINTIES...PERIODIC MVFR WEATHER IS STILL
POSSIBLE. LATER TAF ISSUANCES WILL LIKELY BE ABLE TO BECOME MORE
DETERMINISTIC.
KSAV...VFR CONDITIONS WILL PREVAIL THROUGH LATE TODAY...UNTIL
SCATTERED SHRA AND ISOLATED TSRA DEVELOP IN ASSOCIATION WITH THE
SEA BREEZE AND AN APPROACHING COLD FRONT/WAVE OF LOW PRESSURE
INTO TONIGHT. THERE IS A LOW TO MODERATE RISK OF PERIODIC FLIGHT
RESTRICTIONS WITHIN ANY CONVECTION AND EVENTUALLY IN LATE NIGHT
MIST.
EXTENDED AVIATION...MVFR CONDITIONS MAY LINGER THROUGH SATURDAY
MORNING. VFR FOR SUNDAY AND MONDAY. ANOTHER ROUND OF RESTRICTIONS
WILL BE POSSIBLE ON TUESDAY AS A FRONT AFFECTS THE AREA.
&&
.MARINE...
TODAY AND TONIGHT...A WEAK PRESSURE PATTERN WILL PREVAIL...AS THE
LOCAL WATERS BECOME LOCATED BETWEEN A SLOW MOVING COLD FRONT TO
THE NW AND WEAKENING HIGH PRESSURE OFF TO THE SE. WINDS WILL BE
MAINLY SOUTH OR SOUTHWEST AT 15 KT OR LESS TODAY INTO EARLY
TONIGHT...THEN VEER AROUND TO THE SOUTHWEST AND WEST OVERNIGHT.
WIND SPEEDS WILL ALSO INCREASE A FEW KNOTS...AS A WEAK LOW LEVEL
JET CROSSES THE MARINE AREA. WAVE ENERGY IS MAINLY COMPRISED OF
8-10 SECOND SWELLS...AND WITH SIGNIFICANT WAVE HEIGHTS WILL ACHIEVE
NO MORE THAN 2 OR 3 FT. MARINERS ARE ADVISED THAT ISOLATED
THUNDERSTORMS COULD OCCUR TONIGHT IN ADVANCE OF THE COLD FRONT.
SATURDAY THROUGH WEDNESDAY...A COLD FRONT WILL WORK ITS WAY ACROSS
THE WATERS SATURDAY WITH HIGH PRESSURE BUILDING IN FROM THE WEST
ON SUNDAY. THE HIGH WILL REMAIN THE DOMINANT FEATURE THROUGH THE
WEEKEND...BEFORE THE FRONT WORKS ITS WAY BACK TOWARD THE AREA LATE
IN THE PERIOD. WIND/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY THRESHOLDS THROUGH THE PERIOD. WINDS WILL PRIMARILY SEE
SHIFTING DIRECTIONS AS THE HIGH BUILDS IN...PASSES BY TO THE
NORTH...AND THEN OFF THE MID ATLANTIC COAST. WINDS WILL
PREDOMINANTLY BECOME NE AND THEN E SUNDAY THROUGH MONDAY...THEN
AROUND TO THE NW BY MID WEEK.
&&
.TIDES/COASTAL FLOODING...
CONDITIONS WILL PROBABLY FALL SHORT OF COASTAL FLOODING CRITERIA
WITH THE EVENING HIGH TIDE...DESPITE THE OCCURRENCE OF THE FULL
HUNTERS MOON AT 2338 UTC.
ALTHOUGH WINDS WILL NOT BE MUCH OF A FACTOR...LINGERING
ASTRONOMICAL INFLUENCES WILL RESULT IN ELEVATED TIDES THIS
WEEKEND. WINDS WILL INCREASE AND VEER AROUND TO THE NORTHEAST
EARLY NEXT WEEK...COMPENSATING FOR THE WANING EFFECTS OF THE FULL
MOON. AS A RESULT...COASTAL FLOOD ADVISORIES ARE POSSIBLE INTO
MONDAY OR EVEN POSSIBLY TUESDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...WMS
SHORT TERM...BSH
LONG TERM...BSH
AVIATION...WMS
MARINE...WMS/BSH
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
222 AM EDT FRI OCT 18 2013
.PREV DISCUSSION... /ISSUED 731 PM EDT THU OCT 17 2013/
EVENING UPDATE...
THE COLD FRONT HAS JUST PUSHED SOUTH OF ATLANTA WITH PATCHY
SHOWERS...LIGHT RAIN AND DRIZZLE ALONG AND AHEAD OF THE FRONT... NOW
MOSTLY ACROSS CENTRAL GA. NOT SUFFICIENT LIFT NOR INSTABILITY TO
WARRANT MENTION OF THUNDER THE REST OF TONIGHT... SO HAVE UPDATED
ZONES TO REMOVE THUNDER WORDING. CLOUDS STRETCH WELL BACK INTO TN
AND NW AL... SO HAVE TWEAKED CLOUDS TO SHOW A SLOW SCATTERING OVER
NORTH GA THIS EVENING AND OVERNIGHT... THEN HELD ONTO MOSTLY CLOUDY
SKIES ACROSS MUCH OF CENTRAL GA THROUGH TONIGHT. ADJUSTED POPS TO
BETTER ALIGN WITH RADAR TRENDS. OTHERWISE... FORECAST IS ON TRACK
WITH SCATTERED SKIES AND COOLER LOWS IN THE 40S STILL EXPECTED TO
SPREAD INTO NORTH GA BY MORNING. /39
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
/ISSUED AT 344 PM EDT THU OCT 17 2013/
SHORT TERM MODELS IN FAIRLY GOOD AGREEMENT...SHOWING WEAKEN FRONT
WASHING OUT AS IT MOVES ACROSS THE FORECAST AREA THIS AFTERNOON AND
EVENING. LATEST RAP HAS INITIALIZED AREA OF SHOWERS WELL AND NEAR
TERM FORECAST WILL LEAN HEAVILY TOWARD RAP AS SHOWERS DISSIPATE IN
THE ATL AREA BY 4-5PM AND OVER THE GVL-AHN AREA BY THIS EVENING.
WILL GO AHEAD AND DROP MENTION OF THUNDER FROM FORECAST AS
INSTABILITY LIMITED AS WEAK WAVES MOVES ACROSS THE AREA THIS
AFTERNOON AND EVENING AND THE SHOWER ACTIVITY IS PUSHING OUT OF
FORECAST AREA AS THE SHORTWAVE APPROACHES. MODELS BRINGING DRIER AIR
INTO THE AREA THIS EVENING WITH CLEARING SKIES BY MORNING. LATEST
SATELLITE SHOWING CLOUDS CONTINUE BACK INTO PORTIONS OF MISSISSIPPI
AND EXPECT THAT WHILE THERE WILL BE DRYING WE CAN ALSO EXPECT SOME
COOL AREA STRATUS TO DEVELOP AS WELL. WILL COMPROMISE FOR NOW AND
SETTLED ON SCATTERING CLOUDS OUT THIS EVENING BUT DID NOT CLEAR THEM
OUT ALTOGETHER. BASED UPON HOLDING SOME CLOUDS IN HAVE GONE WARMER
THAN GUIDANCE TEMPERATURES BY A DEGREE OR SO OVERNIGHT WITH HIGHS
TOMORROW SLIGHTLY WARMER THAN TODAY.
ATWELL
LONG TERM /SATURDAY THROUGH THURSDAY/...
/ISSUED AT 344 PM EDT THU OCT 17 2013/
NO MAJOR CHANGES MADE TO THE EXTENDED FORECAST. MODELS CONSISTENT
INDICATING THE COLD FRONT WITH BE SE OF THE FORECAST AREA TO START
FRIDAY NIGHT. HOWEVER GFS/NAM/EUROPEAN SOMEWHAT DIFFERENT WITH THE
PLACEMENT OF THE DEEPER MOISTURE AXIS THROUGH THE NIGHT. GFS/NAM
SIMILAR WITH SPREADING DEEPER MOISTURE BACK OVER MAINLY CENTRAL GA
AND THE EUROPEAN IS MORE BROADLY SPREADING MOISTURE ACROSS THE
ENTIRE AREA BY NIGHTS END. ALL IN ALL THIS SEEMS TO KEEP BEST
SHOWER CHANCES ACROSS MAINLY CENTRAL GA. GFS/NAM KEEPS THE BEST
MOISTURE AND SHOWER CHANCES ACROSS CENTRAL GA FOR SATURDAY WHILE
THE EUROPEAN SPREADS MOISTURE AND SHOWER CHANCES ACROSS THE ENTIRE
AREA. EITHER WAY THE BEST CHANCES FOR SHOWERS WILL BE ACROSS
CENTRAL GA AND POSSIBLY PORTIONS OF N GA. THE MOISTURE COMING N
DUE MAINLY TO THE APPROACH OF A SHORT WAVE.
THE MOISTURE WILL HAVE EXITED ALL BUT THE FAR SE CWA TO START SUNDAY
BUT WILL EXIT THAT AREA QUICKLY. SURFACE HIGH PRESSURE MOVES INTO
THE ATLANTIC ON MONDAY WHICH BEGINS TO SPREAD MOISTURE INTO THE FAR
SE CWA WITH SMALL SHOWER CHANCES ASSOCIATED. A WEAK COLD FRONT MOVES
TO THE AREA ON TUESDAY WITH INCREASED SHOWER CHANCES ACROSS THE AREA
TUESDAY/TUESDAY NIGHT. SMALL SHOWER CHANCES WILL BE CONFINED TO THE
FAR SE CWA TO START THE DAY ON WEDNESDAY BEFORE ENDING.
TEMPERATURES WILL BE TRENDING TO A LITTLE BELOW NORMAL FOR MUCH OF
THE EXTENDED PERIOD.
BDL/01
01
&&
.AVIATION...
06Z UPDATE...
LATEST SURFACE ANALYSIS INDICATES THAT AT LEAST AS FAR AS THE WIND
SHIFT IS CONCERNED...COLD FRONT HAS MADE IT THROUGH ALL THE
TERMINALS. DRIER AIR MOVING IN IS MUCH DELAYED...ESPECIALLY LOW
LEVEL MOISTURE WHICH IS PRODUCING LIFR FOG OVER PORTIONS OF
ALABAMA AND TENNESSEE. GUIDANCE SUGGESTS MOST OF THIS WILL REMAIN
NORTH OF THE TERMINALS WITH JUST CONTINUED MVFR FOR ATL TAF SITES
THROUGH MID MORNING. FOR CSG AND MCN...POTENTIAL IS THERE FOR IFR
AND HAVE ADVERTISED IN 06Z SET FOR THE MORNING HOUR.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM TO HIGH CONFIDENCE ON ALL
ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 74 55 72 49 / 5 20 20 10
ATLANTA 73 59 71 49 / 5 10 20 10
BLAIRSVILLE 68 48 72 42 / 5 5 10 5
CARTERSVILLE 72 52 75 45 / 5 5 10 5
COLUMBUS 79 61 74 51 / 10 30 30 10
GAINESVILLE 69 56 74 48 / 5 5 20 5
MACON 77 61 74 51 / 10 40 30 10
ROME 73 50 75 43 / 5 5 10 5
PEACHTREE CITY 73 54 72 46 / 5 10 20 10
VIDALIA 82 65 77 59 / 30 50 30 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DEESE
LONG TERM....20
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1022 PM CDT SAT OCT 19 2013
.DISCUSSION...
927 PM CDT
NO CHANGES TO CURRENT FROST ADVISORY.
LATEST SATELLITE/RADAR IMAGERY DEPICTING CLOUD COVER ISOLATED
LIGHT SHOWERS STILL ACROSS THE CWA...ASSOCIATED WITH UPPER LEVEL
WAVE/TROUGH AND SURFACE REFLECTION. ALTHOUGH LATEST RAP ANALYSIS
IS INDICATING SOME PERSISTENT WEAK WAA ACROSS NORTH CENTRAL
ILLINOIS...THIS SHOULD WEAKEN OVER THE NEXT SEVERAL HOURS AS
TROUGH DEPARTS TO THE EAST. CLEARING SKIES AND DIMINISHING WINDS
SHOULD ALLOW FOR TEMPS TO STILL DROP OVERNIGHT...WITH THIS ALREADY
BEING OBSERVED IN LOCATIONS THAT SAW SOME PARTIAL CLEARING EARLY
ON. SO HAVE MADE MINOR ADJUSTMENTS TO TEMPS TONIGHT WITH CURRENT
ADVISORY LOCATION STILL APPEARING TO BE ON TRACK. DESPITE THIS
BEING THE PREFERRED LOCATION FOR BETTER FROST DEVELOPMENT...PATCHY
FROST CANNOT BE RULED OUT BRIEFLY LATE TONIGHT INTO EARLY SUNDAY
MORNING FOR THE REMAINDER OF THE CWA. ALSO...LATEST DEWPOINT
TRENDS COINCIDING WITH TEMPS TONIGHT COULD ALLOW FOR PATCHY
FOG...AND HAVE ADDED TO THE GRIDS PRIMARILY FOR NORTHERN ILLINOIS.
RODRIGUEZ
//PREV DISCUSSION...
243 PM CDT
REST OF THE WEEKEND...TONIGHT THROUGH SUNDAY NIGHT...
WEATHER TO BE CONTROLLED BY THE LARGE UPPER TROUGH EXTENDING
ACROSS WESTERN HUDSON BAY SOUTHWARD TO THE OZARKS EARLY THIS
AFTERNOON MOVING TO EASTERN CANADA AND NEW ENGLAND OVERNIGHT AND
DURING SUNDAY. THIS WILL ALLOW WEAK UPPER RIDGING TO OCCUR OVER
THE GREAT LAKES AND MIDWEST SUNDAY AS THIS UPPER TROUGH ROTATES
NORTHEASTWARD AND ANOTHER UPPER TROUGH DEEPENS OVER THE UPPER
MIDWEST AND THE UPPER AND MID MS VALLEY DURING SUNDAY AND SUNDAY
NIGHT.
HAVE RETAINED MENTION OF FROST ACROSS ACROSS NORTH CENTRAL AND
NORTHEAST IL OUTSIDE OF THE METRO AREA THOUGH CONFIDENCE IS NOT
PARTICULARLY HIGH AS WARM AIR ADVECTION CLOUDS CONTINUE TO SPREAD
FROM IA ACROSS NORTHERN IL LATER THIS AFTERNOON AND TONIGHT
SHOULD BE ENOUGH BREAKS DURING THE OVERNIGHT FOR AREAS OF FROST.
A BACKING AND INCREASING LOW LEVEL FLOW DURING SUNDAY WILL ALLOW
SOME MODERATION IN TEMPERATURES AS SIGNIFICANT WARM AIR ADVECTION
OCCURS. WHILE CLOUDS ARE EXPECTED TO GRADUALLY BE ON THE INCREASE
DURING THE DAY THE WARM AIR ADVECTION ITSELF SHOULD PUSH SUNDAY
HIGH TEMPERATURES UP TO THE UPPER 50S NORTH TO MID 60S SOUTHWEST.
DESPITE THE INCREASING CLOUDINESS AS THE UPPER WAVE ROTATES
ACROSS FROM THE NORTHERN PLAINS TO OVER MN AND IA ANY REAL THREAT
OF RAIN WILL REMAIN NORTH OF THE WI BORDER WHERE THE BEST FORCING
WILL BE. AS THE UPPER TROUGH MOVES TO WESTERN WI AND NORTHWEST
AND WEST CENTRAL IL DURING SUNDAY NIGHT POPS WILL RISE TO SLIGHT
CHANCE AS THE UPPER TROUGH APPROACHES AND AN ASSOCIATED COLD
FRONT PUSHES SOUTHEASTWARD ACROSS THE LOCAL FORECAST AREA.
MONDAY THROUGH SATURDAY...
THE MODERATION IN TEMPERATURES WILL BE SHORT LIVED AS THE UPPER
FLOW STARTS TO RETURN TO STRONG NORTHWESTERLY ACROSS THE AREA BY
MONDAY NIGHT WITH A SERIES OF SHORT WAVES ROTATING THROUGH THE
UPPER TROUGH PROVIDING REINFORCING SHOTS OF VERY COOL AIR THROUGH
THE WEEK KEEPING HIGH TEMPERATURES DOWN TO MID 40S TO LOWER
50S...WITH LOWS FROM UPPER 20S TO MID 30S.
USING THE 12Z ECMWF AS A GOOD COMPROMISE BETWEEN MODEL SOLUTIONS
THE MAIN PERIODS FOR A THREAT OF PRECIPITATION ARE FROM LATER
TUESDAY INTO WEDNESDAY AS A SHORT WAVE APPROACHES AND MOVES
ACROSS THE AREA AND THEN NEXT SATURDAY AS AN UPPER TROUGH MOVES
EAST OVER THE UPPER MIDWEST AND THE MID AND LOWER MO VALLEY
REGIONS PUSHING ANOTHER COLD FRONT INTO THE LOCAL AREA DURING THE
DAY.
WITH THE TUESDAY-TUESDAY NIGHT SHORT WAVE TROUGH PASSAGE THE
COLUMN COOLS TO BELOW 0C ACROSS NORTH CENTRAL AND FAR NORTHEAST
IL DURING THURSDAY NIGHT SO ANY REMAINING RAIN MAY MIX WITH OR
CHANGE TO SNOW BEFORE ENDING.
WITH SEVERAL SHORT WAVES TO BE ROTATING THROUGH THE MEAN UPPER
TROUGH THERE COULD BE OTHER TIME-FRAMES WHEN THERE WOULD BE AT
LEAST A SLIGHT CHANCE TO LOW END CHANCE OF PRECIPITATION BUT
TIMING OF ANY ONE OF THESE SMALLER DISTURBANCES IS PRETTY MUCH
FUTILE THESE FEATURES TYPICALLY GET LOST IN THE NOISE OF THE
PROGS.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* PERIOD OF STRONG SOUTH WINDS PROBABLE SUNDAY AFTERNOON
IZZI
//DISCUSSION...UPDATED 03Z...
HAVE ADDED A PROB30 FOR SHRA SUNDAY EVENING FOR ORD...SOME OF THE
LATEST GUIDANCE COMING IN IS LOOKING A BIT MORE PROMISING FOR SOME
SHOWERS WITH THE COLD FRONT SUNDAY EVENING. ALSO...LATEST GUIDANCE
A BIT MORE SUPPORTIVE OF THE IDEA OF STRONG SOUTH WINDS SUNDAY
WHICH DOES AID IN CONFIDENCE IN THIS SCENARIO A BIT...THOUGH CLOUD
COVER IS WORRISOME.
IZZI
UPDATED 00Z...
UPPER DISTURBANCE PRODUCING SCTD SHRA AND VFR CIGS SHOULD MOVE
EAST OF THE REGION THIS EVENING WITH SHRA ENDING EARLY THIS
EVENING FOLLOWED BY AT LEAST PARTIAL CLEARING OVERNIGHT. VFR CIGS
ROLL BACK IN SUNDAY MORNING IN ADVANCE OF THE NEXT FAST MOVING
SYSTEM MOVING INTO THE REGION. FAST MOVING SURFACE LOW WILL TRACK
EAST ALONG IA/MN BORDER INTO SOUTHERN WI SUNDAY INTO SUNDAY
EVENING RESULTING IN LIGHT WINDS TONIGHT BECOMING SOUTH OR
SOUTHEAST SUNDAY MORNING BEFORE VEERING MORE SOUTH TO SOUTH-
SOUTHWEST SUNDAY AFTERNOON. WINDS WILL BE ON THE INCREASE LATE
SUNDAY MORNING AND PARTICULARLY SUNDAY AFTERNOON AS STRONG
PRESSURE FALLS EAST OF THE SFC LOW RESULT IN A HEALTHY INCREASE IN
WIND SPEEDS. DOES APPEAR AS THOUGH SKIES SHOULD BE OVC WHICH MAY
LIMIT MIXING AND RESULT STRENGTH AND GUSTINESS OF THE WINDS.
CONFIDENCE IS NOT HIGH BUT OPTED TO MAINTAIN 15G25KT FOR A PERIOD
SUNDAY AFTERNOON/EARLY EVENING. STRONG SOUTH WINDS WOULD CAUSE
PRETTY GOOD CROSSWIND FOR ORD AND DID NOT WANT TO FLIP-FLOP ON THE
FORECAST. WILL LIKELY BE SOME VIRGA IF NOT LIGHT SHOWERS/SPRINKLES
AROUND SUNDAY EVENING BUT IMPACT WILL BE MINIMAL AND COVERAGE LOW
SO KEPT PRECIP OUT OF THE TAFS.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM CONFIDENCE IN WINDS SUNDAY AFTERNOON
* HIGH CONFIDENCE IN REMAINDER OF THE FORECAST
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...MVFR CIGS LIKELY.
TUESDAY...MVFR CIGS POSSIBLE. CHANCE OF -RA OR -RSSN.
WEDNESDAY...MVFR CIGS POSSIBLE...MAINLY EARLY.
THURSDAY AND FRIDAY...PROBABLY VFR.
IZZI
&&
.MARINE...
334 PM CDT
A VERY ACTIVE PERIOD ON THE WAY ACROSS THE LAKE AS A SERIES OF LOW
PRESSURE SYSTEMS AND A UNSEASONABLY COLD AIR MASS COMBINE TO BRING
STRONG WINDS MOST OF THE FORECAST PERIOD. WEST WINDS OVER THE SOUTH
HALF WILL RAMP UP TO 30 KT THIS EVENING BEFORE DIMINISHING SOME
LATE. THERE WILL BE A BRIEF PERIOD OF LIGHTER SOUTH WINDS SUNDAY
MORNING BEFORE LOW PRESSURE APPROACHES FROM THE WEST LATER SUNDAY
AND SOUTHERLY WINDS INCREASE.
SOME UNCERTAINTY EXISTS AS TO THE TRACK AND TIMING OF THE LOW...BUT
THERE IS GOOD AGREEMENT AMONGST GUIDANCE FOR SOUTH TO SOUTHWEST
WINDS UP TO GALE FORCE SOMETIME SUNDAY EVENING INTO THE OVERNIGHT
FOR THE CENTRAL AND SOUTHERN PORTION OF THE LAKE. THEREFORE HAVE
ISSUED A GALE WATCH FOR THE CENTRAL AND SOUTH STARTING AT 00Z
SUNDAY. A VERY STRONG COLD FRONT WILL SWEEP ACROSS THE LAKE AS THE
LOW LIFTS TO EASTERN LAKE SUPERIOR BY EARLY MONDAY AND DEEPENS.
SOUTHWEST GALES WILL QUICKLY TRANSITION TO WESTERLY GALES ON THE
CENTRAL AND SOUTH...WHILE WESTERLY GALES WILL DEVELOP OVER THE NORTH
TOWARD EARLY MONDAY MORNING. A WINTER LIKE AIRMASS WILL POUR ACROSS
THE LAKE...SUPPORTING EXTREMELY UNSTABLE CONDITIONS AND EFFICIENT
MIXING. WEST GALES WILL INCREASE TO 40 KT ON THE NORTH PART OF THE
LAKE ON MONDAY...WITH 35 KT CONTINUING TO THE SOUTH. THERE THEN
APPEARS TO BE ANOTHER COLD FRONT OR SECONDARY SURGE OF COLD AIR
MONDAY NIGHT EXPECTED TO KEEP GALES GOING ON THE NORTH ALL THE WAY
INTO TUESDAY MORNING. THUS HAVE EXTENDED THE GALE WATCH THERE UNTIL
15Z TUESDAY.
FOR THE NEARSHORE WATERS...HAVE EXTENDED THE SMALL CRAFT ADVISORY
FOR GARY AND POINTS EAST UNTIL 9Z SUNDAY AS WAVES WILL BE SLOWER TO
SUBSIDE. WILL THEN LIKELY NEED A SMALL CRAFT ADVISORY FOR ALL THE
NEARSHORE ZONES SOMETIME SUNDAY EVENING THROUGH MONDAY
EVENING...THEN AT LEAST A PORTION OF THE INDIANA NEARSHORE ALL THE
WAY THROUGH TUESDAY EVENING DUE TO WAVES.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FROST ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012 UNTIL 8 AM SUNDAY.
IN...NONE.
LM...GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 PM
SUNDAY TO 4 AM TUESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...3 AM
MONDAY TO 10 AM TUESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
940 PM CDT SAT OCT 19 2013
.DISCUSSION...
927 PM CDT
NO CHANGES TO CURRENT FROST ADVISORY.
LATEST SATELLITE/RADAR IMAGERY DEPICTING CLOUD COVER ISOLATED
LIGHT SHOWERS STILL ACROSS THE CWA...ASSOCIATED WITH UPPER LEVEL
WAVE/TROUGH AND SURFACE REFLECTION. ALTHOUGH LATEST RAP ANALYSIS
IS INDICATING SOME PERSISTENT WEAK WAA ACROSS NORTH CENTRAL
ILLINOIS...THIS SHOULD WEAKEN OVER THE NEXT SEVERAL HOURS AS
TROUGH DEPARTS TO THE EAST. CLEARING SKIES AND DIMINISHING WINDS
SHOULD ALLOW FOR TEMPS TO STILL DROP OVERNIGHT...WITH THIS ALREADY
BEING OBSERVED IN LOCATIONS THAT SAW SOME PARTIAL CLEARING EARLY
ON. SO HAVE MADE MINOR ADJUSTMENTS TO TEMPS TONIGHT WITH CURRENT
ADVISORY LOCATION STILL APPEARING TO BE ON TRACK. DESPITE THIS
BEING THE PREFERRED LOCATION FOR BETTER FROST DEVELOPMENT...PATCHY
FROST CANNOT BE RULED OUT BRIEFLY LATE TONIGHT INTO EARLY SUNDAY
MORNING FOR THE REMAINDER OF THE CWA. ALSO...LATEST DEWPOINT
TRENDS COINCIDING WITH TEMPS TONIGHT COULD ALLOW FOR PATCHY
FOG...AND HAVE ADDED TO THE GRIDS PRIMARILY FOR NORTHERN ILLINOIS.
RODRIGUEZ
&&
.PREV DISCUSSION...
243 PM CDT
REST OF THE WEEKEND...TONIGHT THROUGH SUNDAY NIGHT...
WEATHER TO BE CONTROLLED BY THE LARGE UPPER TROUGH EXTENDING
ACROSS WESTERN HUDSON BAY SOUTHWARD TO THE OZARKS EARLY THIS
AFTERNOON MOVING TO EASTERN CANADA AND NEW ENGLAND OVERNIGHT AND
DURING SUNDAY. THIS WILL ALLOW WEAK UPPER RIDGING TO OCCUR OVER
THE GREAT LAKES AND MIDWEST SUNDAY AS THIS UPPER TROUGH ROTATES
NORTHEASTWARD AND ANOTHER UPPER TROUGH DEEPENS OVER THE UPPER
MIDWEST AND THE UPPER AND MID MS VALLEY DURING SUNDAY AND SUNDAY
NIGHT.
HAVE RETAINED MENTION OF FROST ACROSS ACROSS NORTH CENTRAL AND
NORTHEAST IL OUTSIDE OF THE METRO AREA THOUGH CONFIDENCE IS NOT
PARTICULARLY HIGH AS WARM AIR ADVECTION CLOUDS CONTINUE TO SPREAD
FROM IA ACROSS NORTHERN IL LATER THIS AFTERNOON AND TONIGHT
SHOULD BE ENOUGH BREAKS DURING THE OVERNIGHT FOR AREAS OF FROST.
A BACKING AND INCREASING LOW LEVEL FLOW DURING SUNDAY WILL ALLOW
SOME MODERATION IN TEMPERATURES AS SIGNIFICANT WARM AIR ADVECTION
OCCURS. WHILE CLOUDS ARE EXPECTED TO GRADUALLY BE ON THE INCREASE
DURING THE DAY THE WARM AIR ADVECTION ITSELF SHOULD PUSH SUNDAY
HIGH TEMPERATURES UP TO THE UPPER 50S NORTH TO MID 60S SOUTHWEST.
DESPITE THE INCREASING CLOUDINESS AS THE UPPER WAVE ROTATES
ACROSS FROM THE NORTHERN PLAINS TO OVER MN AND IA ANY REAL THREAT
OF RAIN WILL REMAIN NORTH OF THE WI BORDER WHERE THE BEST FORCING
WILL BE. AS THE UPPER TROUGH MOVES TO WESTERN WI AND NORTHWEST
AND WEST CENTRAL IL DURING SUNDAY NIGHT POPS WILL RISE TO SLIGHT
CHANCE AS THE UPPER TROUGH APPROACHES AND AN ASSOCIATED COLD
FRONT PUSHES SOUTHEASTWARD ACROSS THE LOCAL FORECAST AREA.
MONDAY THROUGH SATURDAY...
THE MODERATION IN TEMPERATURES WILL BE SHORT LIVED AS THE UPPER
FLOW STARTS TO RETURN TO STRONG NORTHWESTERLY ACROSS THE AREA BY
MONDAY NIGHT WITH A SERIES OF SHORT WAVES ROTATING THROUGH THE
UPPER TROUGH PROVIDING REINFORCING SHOTS OF VERY COOL AIR THROUGH
THE WEEK KEEPING HIGH TEMPERATURES DOWN TO MID 40S TO LOWER
50S...WITH LOWS FROM UPPER 20S TO MID 30S.
USING THE 12Z ECMWF AS A GOOD COMPROMISE BETWEEN MODEL SOLUTIONS
THE MAIN PERIODS FOR A THREAT OF PRECIPITATION ARE FROM LATER
TUESDAY INTO WEDNESDAY AS A SHORT WAVE APPROACHES AND MOVES
ACROSS THE AREA AND THEN NEXT SATURDAY AS AN UPPER TROUGH MOVES
EAST OVER THE UPPER MIDWEST AND THE MID AND LOWER MO VALLEY
REGIONS PUSHING ANOTHER COLD FRONT INTO THE LOCAL AREA DURING THE
DAY.
WITH THE TUESDAY-TUESDAY NIGHT SHORT WAVE TROUGH PASSAGE THE
COLUMN COOLS TO BELOW 0C ACROSS NORTH CENTRAL AND FAR NORTHEAST
IL DURING THURSDAY NIGHT SO ANY REMAINING RAIN MAY MIX WITH OR
CHANGE TO SNOW BEFORE ENDING.
WITH SEVERAL SHORT WAVES TO BE ROTATING THROUGH THE MEAN UPPER
TROUGH THERE COULD BE OTHER TIME-FRAMES WHEN THERE WOULD BE AT
LEAST A SLIGHT CHANCE TO LOW END CHANCE OF PRECIPITATION BUT
TIMING OF ANY ONE OF THESE SMALLER DISTURBANCES IS PRETTY MUCH
FUTILE THESE FEATURES TYPICALLY GET LOST IN THE NOISE OF THE
PROGS.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* PERIOD OF STRONG SOUTH WINDS POSSIBLE SUNDAY AFTERNOON
IZZI
//DISCUSSION...UPDATED 00Z...
UPPER DISTURBANCE PRODUCING SCTD SHRA AND VFR CIGS SHOULD MOVE
EAST OF THE REGION THIS EVENING WITH SHRA ENDING EARLY THIS
EVENING FOLLOWED BY AT LEAST PARTIAL CLEARING OVERNIGHT. VFR CIGS
ROLL BACK IN SUNDAY MORNING IN ADVANCE OF THE NEXT FAST MOVING
SYSTEM MOVING INTO THE REGION. FAST MOVING SURFACE LOW WILL TRACK
EAST ALONG IA/MN BORDER INTO SOUTHERN WI SUNDAY INTO SUNDAY
EVENING RESULTING IN LIGHT WINDS TONIGHT BECOMING SOUTH OR
SOUTHEAST SUNDAY MORNING BEFORE VEERING MORE SOUTH TO SOUTH-
SOUTHWEST SUNDAY AFTERNOON. WINDS WILL BE ON THE INCREASE LATE
SUNDAY MORNING AND PARTICULARLY SUNDAY AFTERNOON AS STRONG
PRESSURE FALLS EAST OF THE SFC LOW RESULT IN A HEALTHY INCREASE IN
WIND SPEEDS. DOES APPEAR AS THOUGH SKIES SHOULD BE OVC WHICH MAY
LIMIT MIXING AND RESULT STRENGTH AND GUSTINESS OF THE WINDS.
CONFIDENCE IS NOT HIGH BUT OPTED TO MAINTAIN 15G25KT FOR A PERIOD
SUNDAY AFTERNOON/EARLY EVENING. STRONG SOUTH WINDS WOULD CAUSE
PRETTY GOOD CROSSWIND FOR ORD AND DID NOT WANT TO FLIP-FLOP ON THE
FORECAST. WILL LIKELY BE SOME VIRGA IF NOT LIGHT SHOWERS/SPRINKLES
AROUND SUNDAY EVENING BUT IMPACT WILL BE MINIMAL AND COVERAGE LOW
SO KEPT PRECIP OUT OF THE TAFS.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* LOW CONFIDENCE IN WINDS SUNDAY AFTERNOON
* HIGH CONFIDENCE IN REMAINDER OF THE FORECAST
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...MVFR CIGS LIKELY.
TUESDAY...MVFR CIGS POSSIBLE. CHANCE OF -RA OR -RSSN.
WEDNESDAY...MVFR CIGS POSSIBLE...MAINLY EARLY.
THURSDAY AND FRIDAY...PROBABLY VFR.
IZZI
&&
.MARINE...
334 PM CDT
A VERY ACTIVE PERIOD ON THE WAY ACROSS THE LAKE AS A SERIES OF LOW
PRESSURE SYSTEMS AND A UNSEASONABLY COLD AIR MASS COMBINE TO BRING
STRONG WINDS MOST OF THE FORECAST PERIOD. WEST WINDS OVER THE SOUTH
HALF WILL RAMP UP TO 30 KT THIS EVENING BEFORE DIMINISHING SOME
LATE. THERE WILL BE A BRIEF PERIOD OF LIGHTER SOUTH WINDS SUNDAY
MORNING BEFORE LOW PRESSURE APPROACHES FROM THE WEST LATER SUNDAY
AND SOUTHERLY WINDS INCREASE.
SOME UNCERTAINTY EXISTS AS TO THE TRACK AND TIMING OF THE LOW...BUT
THERE IS GOOD AGREEMENT AMONGST GUIDANCE FOR SOUTH TO SOUTHWEST
WINDS UP TO GALE FORCE SOMETIME SUNDAY EVENING INTO THE OVERNIGHT
FOR THE CENTRAL AND SOUTHERN PORTION OF THE LAKE. THEREFORE HAVE
ISSUED A GALE WATCH FOR THE CENTRAL AND SOUTH STARTING AT 00Z
SUNDAY. A VERY STRONG COLD FRONT WILL SWEEP ACROSS THE LAKE AS THE
LOW LIFTS TO EASTERN LAKE SUPERIOR BY EARLY MONDAY AND DEEPENS.
SOUTHWEST GALES WILL QUICKLY TRANSITION TO WESTERLY GALES ON THE
CENTRAL AND SOUTH...WHILE WESTERLY GALES WILL DEVELOP OVER THE NORTH
TOWARD EARLY MONDAY MORNING. A WINTER LIKE AIRMASS WILL POUR ACROSS
THE LAKE...SUPPORTING EXTREMELY UNSTABLE CONDITIONS AND EFFICIENT
MIXING. WEST GALES WILL INCREASE TO 40 KT ON THE NORTH PART OF THE
LAKE ON MONDAY...WITH 35 KT CONTINUING TO THE SOUTH. THERE THEN
APPEARS TO BE ANOTHER COLD FRONT OR SECONDARY SURGE OF COLD AIR
MONDAY NIGHT EXPECTED TO KEEP GALES GOING ON THE NORTH ALL THE WAY
INTO TUESDAY MORNING. THUS HAVE EXTENDED THE GALE WATCH THERE UNTIL
15Z TUESDAY.
FOR THE NEARSHORE WATERS...HAVE EXTENDED THE SMALL CRAFT ADVISORY
FOR GARY AND POINTS EAST UNTIL 9Z SUNDAY AS WAVES WILL BE SLOWER TO
SUBSIDE. WILL THEN LIKELY NEED A SMALL CRAFT ADVISORY FOR ALL THE
NEARSHORE ZONES SOMETIME SUNDAY EVENING THROUGH MONDAY
EVENING...THEN AT LEAST A PORTION OF THE INDIANA NEARSHORE ALL THE
WAY THROUGH TUESDAY EVENING DUE TO WAVES.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FROST ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012...1 AM SUNDAY TO 8 AM SUNDAY.
IN...NONE.
LM...GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 PM
SUNDAY TO 4 AM TUESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...3 AM
MONDAY TO 10 AM TUESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS DES MOINES IA
322 PM CDT FRI OCT 18 2013
.SHORT TERM /TONIGHT/...
ISSUED AT 323 PM CDT FRI OCT 18 2013
IN A NEAR REPEAT OF YESTERDAY AFTERNOONS FORECAST...ANOTHER 500 MB
SHORTWAVE EMBEDDED IN THE MEAN CENTRAL NORTH AMERICAN LONGWAVE
TROUGH IS POISED TO TRACK THROUGH IOWA LATE TONIGHT AND INTO
TOMORROW MORNING. AS WITH ITS PREDECESSOR...FORCING AND MOISTURE
WILL BE SPARSE AND ANY RAIN SHOWERS OVERNIGHT WILL BE CONFINED TO
NORTHERN IOWA. THIS SCENARIO WAS HANDLED WELL BY THE HIGH RES WRF
ARW AND RAP...THUS USED A BLEND OF THESE TWO MODELS FOR THE
PRECIPITATION FORECAST. A SECOND IMPULSE/VORT MAX SLIDES DOWN THE
REAR FLANK OF THE LONGWAVE TROUGH IN WESTERN MINNESOTA AND NORTHWEST
IOWA TOWARDS THE END OF THE PERIOD. MOISTURE PROFILES ARE SLIGHTLY
MORE CONDUCIVE FOR RAINFALL AND HAVE INCREASED POPS ACCORDINGLY IN
THE NORTHWEST TOWARDS 12Z SAT.
290 TO 300K ISENTROPIC ACCENT GENERATED A BAND RAIN AND SNOW ACROSS
KANSAS AND NORTHERN MISSOURI TODAY. THE ASSOCIATED SHIELD OF
CIRROSTRATUS AND ALTOSTRATUS CLOUDS PROPAGATED INTO IOWA THIS
MORNING AND PUT A DAMPER ON HIGHS ACROSS THE SOUTHERN HALF OF THE
CWA. THIS SYSTEM WILL PULL ENE THIS EVENING AS THE UPPER LEVEL
TROUGH DIGS INTO THE CENTRAL PLAINS. THERE IS SOME UNCERTAINTY WITH
HOW MUCH OF THE CLOUD COVER OVER SOUTHERN IOWA WILL CLEAR OUT
BETWEEN THE 06 AND 12Z TIMEFRAME. BOTH THE NAM AND RAP SOUNDINGS
HINT AT SOME CLEARING TOWARDS MORNING...SO LOWERED MIN TEMPS IN THE
NISH VALLEY AND OTHER PORTIONS OF SOUTHWEST IOWA.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 323 PM CDT FRI OCT 18 2013
BROAD LONG WAVE TROF WILL REMAIN ENTRENCHED ACROSS THE EASTERN
HALF OF THE UNITED STATES DURING THIS FORECAST PERIOD.
THEREFORE...BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MUCH OF THE
NEXT WEEK. THERE WILL ALSO BE THREATS FOR LIGHT PRECIPITATION FROM
TIME TO TIME AS SYSTEMS PASS THROUGH THE STRONG NORTHWEST FLOW.
FIRST WEAK SYSTEM GLANCES THE NORTH TOMORROW MORNING ALTHOUGH THE
BULK OF THE FORCING WILL REMAIN NORTH OF IOWA. HAVE CONTINUED THE
THREAT FOR SOME ISOLATED/SCATTERED SHOWERS IN THE MORNING BUT WITH
SUBSIDENCE ARRIVING BY AFTERNOON...SHOULD SEE ANY ACTIVITY QUICKLY
ENDING. WARM ADVECTION INTO SUNDAY WILL MAKE IT THE WARMEST DAY
OVER THE NEXT WEEK. THE WARMER AIR IS AHEAD OF THE NEXT SYSTEM
DIVING SOUTHEAST INTO THE REGION. ONCE AGAIN...THE FORCING
ASSOCIATED WITH THIS SYTEM REMAINS NORTH OF IOWA WITH ANY PCPN
THREAT RESIDING NEAR THE MINNESOTA BORDER. STRONG COLD ADVECTION
WILL ARRIVE BY LATE IN THE DAY WITH A MUCH COLDER AIRMASS BECOMING
ESTABLISHED ACROSS THE STATE ON MONDAY. ONE FINAL SYSTEM DROPS
SOUTHEAST TOWARD THE STATE LATE MONDAY NIGHT INTO TUESDAY. THE
EURO IS MOST AGGRESSIVE WITH SATURATION AND LIFT ACROSS IOWA WITH
A FEW TENTHS OF PCPN ON TUESDAY. GIVEN RELATIVELY COLD THERMAL
PROFILES DURING THIS EVENT...WOULDNT BE SURPRISED TO SEE SOME SNOW
MIXED WITH RAIN WITH STRONG DYNAMICAL COOLING SUGGESTED BY THE
LIFT. THE COLDER AIRMASS WILL THEN REMAIN ESSENTIALL IN PLACE
THROUGH THE END OF NEXT WEEK. THIS SHOULD EFFECTIVELY END THE
GROWING SEASON ACROSS CENTRAL IOWA FOR THOSE LOCATIONS THAT HAVENT
ALREADY SEEN A FREEZE.
&&
.AVIATION...18/18Z
ISSUED AT 1240 PM CDT FRI OCT 18 2013
VFR CONDITIONS SHOULD PREVAIL OVER CENTRAL IOWA THROUGH MUCH OF
THE TAF PERIOD. A FRONT PUSHING SOUTHEAST MIGHT BRING SOME LOW
CLOUDS AND SHOWERS TO NORTHERN IOWA TOMORROW MORNING...BUT DRIER
AIR NEAR THE SURFACE SHOULD LIMIT THE EXTENT OF LOWER CEILINGS.
WINDS WILL REMAIN OUT OF THE WEST TO NORTHWEST THROUGH THE PERIOD
WITH DIURNAL FLUCTUATIONS IN WIND SPEED.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...COGIL
AVIATION...SKOW
AREA FORECAST DISCUSSION
NWS TOPEKA KS
307 PM CDT Fri Oct 18 2013
.SHORT TERM...(This Evening through Saturday)
Issued at 307 PM CDT FRI OCT 18 2013
20z water vapor imagery shows a shortwave propagating across the
state. The forcing from this wave has brought widespread rain and
snow with some light accumulations across portions of north central
KS. Surface obs indicate a mesoscale high is centered over southwest
KS. Areas where precipitation has persisted through the day have had
temps holding steadily in the 30s.
For tonight the forcing from the upper wave should move to the east
of the forecast area with precipitation coming to an end over east
central KS by mid evening. Snow is likely to remain mixed with the
precip, but since the intensity of the snowfall has been light due
to partial melting as it falls. accumulations should remain mainly
trace amounts. As the upper wave moves east, subsidence should
increase allowing skies to become mostly clear. Models do not show a
great deal of cold air advection overnight, but with dewpoints in
the lower 30s and 20s expected to move in think radiational cooling
could drop overnight lows to around 30 for most areas. Because of
this have issued a freeze warning. Saturday looks to be mostly sunny
and warmer as northwest flow aloft is free of shortwaves and
westerly low level flow advects warm air back into the region. All
the models are showing 850 temps in the +6 to +7C range with good
mixing of the boundary layer. This should yield highs in the lower
60s east to the mid 60s across north central KS.
.LONG TERM...(Saturday Night through Friday)
Issued at 307 PM CDT FRI OCT 18 2013
There were not many changes made to the medium and extended range
periods, though this is not because of high confidence. Strong
north-northwest flow over the central portions of the nation will be
the rule through these periods, with minor alterations in
trajectories of these winds and timing of waves moving through the
flow creating opportunities for much cooler northerly flow tapping
airmasses from Alaska or northern Canada, or warmer northwest flow
allowing modified continental air to push in from the west. MOS
temperature output from both the GFS and ECMWF ensembles showing
this issue with large spreads. Sunday still looking to be the
warmest with west to southwest low level flow from Saturday night
into at least early Sunday ahead of a cold front. Cold air advection
is not terribly strong immediately behind the front so despite
northwest winds taking hold over northwestern areas by mid afternoon
and considerable high clouds, still expect middle 60s to around 70
for maxes. Will keep temps a bit cooler than normal otherwise. Lows
still have the potential to be in the frost/freeze range, mainly
Monday night and Tuesday night. There is good agreement in one wave
rotating through the Central Plains late Monday night into late
Tuesday, and will keep small precipitation chances going with it.
Just how strong and moist this system will dictate how much cooling
can occur both before and after its passage.
&&
.AVIATION...(For the 18Z TAFs through 18Z Saturday Afternoon)
Issued at 1224 PM CDT FRI OCT 18 2013
NAM forecast soundings show only about the lowest 1000 ft above
freezing through the afternoon, so there remains the possibility
for mixed precip. RAP and HRRR are in reasonable agreement in the
precip pushing east of TOP and FOE around 00Z. For the most part,
think conditions will be VFR unless some Mixed precip moves in
temporarily lowering CIGS and VSBY to MVFR. Once the precip ends,
Conditions should be VFR with dry air and subsidence increasing
behind the upper wave.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING from 10 PM this evening to 9 AM CDT Saturday FOR
KSZ008>012-020>024-026-034>040-054>056-058-059.
&&
$$
SHORT TERM...Wolters
LONG TERM...65
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
118 PM MDT FRI OCT 18 2013
.UPDATE...
ISSUED AT 114 PM MDT FRI OCT 18 2013
UPDATED FORECAST FOR THE DEVELOPMENT OF RAIN SHOWERS AHEAD OF THE 500MB
TROUGH AXIS OUTSIDE OF THE HIGHER SNOWFALL AMOUNTS. THE T-Q INDEX
FROM THE RUC PLACES AN AREA OF BETTER INSTABILITY OVER THE
NORTHEAST PART OF THE AREA THIS AFTERNOON...SO AM ANTICIPATING THE
SHOWERS OVER THE NORTHERN PART OF THE AREA TO INCREASE IN
COVERAGE/INTENSITY. THE SHOWERS SHOULD COME TO AN END BY LATE
AFTERNOON OR EARLY EVENING WHEN SURFACE HEATING COMES TO AN END.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 200 AM MDT FRI OCT 18 2013
TODAY-TONIGHT...AS HAS BEEN ADVERTISED FOR A FEW DAYS AGO UPPER
DISTURBANCE WITH A MIX OF RAIN OR SNOW HAS MOVED THROUGH THE
NORTHWEST 1/2 OF THE FORECAST AREA EARLY THIS MORNING AND WILL
CONTINUE SOUTHEAST THROUGH THE DAY EXITING THE AREA SHORTLY BEFORE
SUNSET. PREVIOUS FORECAST HAD A REALLY GOOD HANDLE ON PRECIP TIMING
SO ONLY MINOR ADJUSTMENTS NEEDED. BIGGEST CHANGE WAS TO LOWER
SNOWFALL AMOUNTS A BIT. SREF SHOWING RATIOS AROUND 5:1 WHICH
PRODUCES AMOUNTS AROUND AN INCH EXCEPT IN YUMA...CHEYENNE KS AND
CO WHERE AROUND 2 INCHES EXPECTED. LATEST WEB CAM IN YUMA CO
SHOWING SNOW JUST NOW STARTING TO STICK TO THE ROADS WITH PERHAPS
AN INCH OR SO ON OTHER SURFACES...THIS MATCHES PRETTY WELL WITH
THE ONE TO TWO INCHES EXPECTED THROUGH 12Z. WILL LET THE WINTER
WEATHER ADVISORY CONTINUE GIVEN ITS THE FIRST SNOW OF THE SEASON
AND THE POSSIBILITY THAT PERHAPS A BIT HIGHER AMOUNTS ARE
POSSIBLE.
HIGHS TODAY UPPER 30S TO MID 40S IN FAR EASTERN COLORADO WITH MID
40S TO LOW 50S ELSEWHERE. LOWS TONIGHT MID 20S TO LOW 30S (WEST TO
EAST).
FOR SATURDAY THROUGH SUNDAY NIGHT THE FORECAST AREA WILL BE UNDER
NORTHWEST FLOW ALOFT. HIGH TEMPERATURES SATURDAY WARM INTO THE
UPPER 50S TO MID 60S WITH LOWS GENERALLY IN THE 30S. SOME COOLER
AIR MOVES THROUGH THE NORTHWEST 2/3 OF THE AREA SUNDAY AS AN UPPER
DISTURBANCE WITHIN THE LARGE UPPER TROUGH MOVES INTO THE AREA.
SHOULD SEE AN INCREASE IN CLOUDINESS AND POSSIBLY SOME LIGHT RAIN
AND/OR SNOW SUNDAY NIGHT. FOR NOW KEEPING THINGS DRY. HIGHS MID
50S TO AROUND 60 IN EASTERN COLORADO WITH LOW TO MID 60S
ELSEWHERE. LOWS SUNDAY NIGHT IN THE 30S.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 230 AM MDT FRI OCT 18 2013
MONDAY THROUGH THURSDAY...THE CWA REMAINS UNDER THE INFLUENCE OF THE
UPPER TROUGH OVER THE MIDWEST/CENTRAL PLAINS MONDAY THROUGH
WEDNESDAY...WITH THE UPPER RIDGE OVER THE ROCKIES MOVING EAST AND
BECOMING LESS AMPLIFIED AS IT APPROACHES THE CWA WEDNESDAY NIGHT INTO
THURSDAY. THE EXTENDED LOOKS DRY...SINCE MODELS NOW HAVE THE UPPER
TROUGH MOVING FURTHER EAST ON WEDNESDAY WITHOUT THE STRONGER VORT
LOBE ROTATING THROUGH THE EASTERN PART OF THE CWA EARLY WEDNESDAY
MORNING. CLOUD COVER WILL INCREASE ON TUESDAY WITH SOME WEAK
VORTICITY MOVING THROUGH THE CWA...WITH PARTLY CLOUDY SKIES
RETURNING DUE TO INCREASING SUBSIDENCE ON WEDNESDAY INTO THURSDAY AS
THE RIDGE MOVES OVER THE CWA.
MONDAY APPEARS TO BE THE COOLEST DAY AFTER THE COLD FROPA LATE
SUNDAY/EARLY MONDAY MORNING WITH HIGHS IN THE MID TO UPPER 50S.
TEMPERATURES SLOWLY WARM-UP THROUGHOUT THE EXTENDED...WHICH IS A
CHANGE FROM YESTERDAY`S MODEL RUNS. SINCE THE MODELS MOVE THE UPPER
TROUGH FURTHER EAST BY WEDNESDAY...THE COLD CANADIAN SURFACE HIGH IS
FURTHER EAST. THE UPPER RIDGE ALSO BEGINS TO MOVE IN ALONG WITH SMALL
HEIGHT RISES...SO HIGHS TUESDAY THROUGH THURSDAY WILL RISE FROM THE
LOW 60S TO THE MID TO UPPER 60S. LOW TEMPERATURES WILL REMAIN
SLIGHTLY ABOVE NORMAL IN THE UPPER 30S TO LOW 40S....DUE TO CLOUD
COVER OVERNIGHT FOR THE FIRST PART OF THE EXTENDED AND DUE TO SLOWLY
RISING TEMPERATURES LATER IN THE EXTENDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1122 AM MDT FRI OCT 18 2013
VFR CONDITIONS FORECAST FOR THE 18Z TAFS. CLOUDS WILL CONTINUE TO
MOVE SOUTHEAST TODAY RESULTING IN CLEARING SKIES. UPSTREAM OF KMCK
CEILINGS ARE MVFR. AM THINKING THE CEILINGS SHOULD RAISE ABOVE
MVFR BEFORE MOVING OVER KMCK. LATE TONIGHT FOG MAY DEVELOP OVER
AREAS THAT RECEIVED 2-3 INCHES OR MORE...SO HAVE INCLUDED A SLIGHT
REDUCTION IN VISIBILITY FOR KGLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...99
LONG TERM...ALW
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1224 PM CDT Fri Oct 18 2013
...AVIATION UPDATE...
.UPDATE...
Issued at 954 AM CDT FRI OCT 18 2013
Getting a few reports of big snow flakes mixing in with the rain
within the band of higher reflectivity. RAP13 soundings near MHK
shows the column above 2 KFT below freezing while the surface temp
remains around +3 to +6C. So the bright banding between 500 and
3000 ft is likely from snow melting. Intensity is expected to
remain on the light side, although cross sections suggested there
is some weak instability and the chance for a brief period of
stronger precip. As long as the intensity is light, no
accumulation of snow is anticipated. If a band of moderate precip
could lead to some light accumulations on grass since surface temps
are expected to hold in the lower 40s.
&&
.SHORT TERM...(Today and Tonight) Issued at 420 AM CDT FRI OCT 18
2013
Main focus for the short term is on the advancing shortwave that
will bring periods of rain showers across the region today. The
mid-level trough that is situated over central Canada and the
Dakotas will continue to dig further south into the Central Plains
today. Water vapor imagery at 09z showed the main shortwave on the
lee side of the Rockies with increasing moisture over northeast
Colorado and southwest Nebraska. As the trough deepens today, this
shortwave will progress southeastward into western Kansas and round
out around the base of the trough over southern Kansas before
ejecting into southern Missouri/northern Arkansas tonight as the
trough quickly pivots eastward. The regional radar loop showed
scattered precipitation developing across northwest Kansas and along
the KS/NE border early this morning, tracking eastward toward north
central Kansas. This precipitation was being supported by decent
mid-level forcing and some isentropic lift. With temperatures in
the lower to middle 30s, several locations in northwest Kansas were
reporting light snow with this activity early this morning.
For this morning, short-range models show some of this scattered
early morning activity extending eastward into portions of north
central Kansas, however this precipitation is expected to become
more widespread across central Kansas by mid/late morning as both
the mid-level forcing and isentropic lift in the 300K-310K layer
noticeably amplify. This decent forcing and lift will continue to
progress into east central and southeast Kansas through the
afternoon hours. Still one area of uncertainty is with regards to
how well or how quickly this shortwave will be able to overcome the
drier air in place over portions of northeast Kansas. Dewpoint
depressions this morning are roughly around 5F degrees, and model
soundings match up well with the mid-levels quickly saturating this
morning with a dry low-layer in place. Several short-range models
are trending a bit further north with the northern extent of the
precipitation today, compared to the last few runs of many synoptic
models. With the early morning precipitation trends across NW
Kansas, have trended the pop forecast today toward this more
northern solution. While the best potential for precipitation
continues to be focused generally along and south of interstate 70
due to the location of the best forcing and lift, have extended
low-end chance pops up to the KS/NE border today to account for the
potential of more widely scattered showers. As this mid-level trough
begins to quickly pivot eastward this afternoon, expect conditions
to dry out from northwest to southeast across the CWA during the
afternoon hours with a few lingering showers still possible
generally along and southeast of the I-35 corridor early this
evening. Since this will be a fairly fast-moving system, QPF amounts
should generally be less than one-quarter inch. As for temperatures,
early morning temperatures as of 09z ranged from the middle 30s to
lower 40s. As cloud cover quickly overspreads the area this morning,
it will significantly limit the amount of daytime heating that can
occur. In fact, expect the high temperatures for the day to be
reached by late morning/early afternoon with dropping temperatures
through the afternoon hours as precipitation overspreads the region
and northwesterly winds usher cooler air into the region. It is
worth noting that model soundings show the deep layer of saturation
today below 0C degrees. So while precipitation aloft will begin as
snow, it is expected to melt and reach the ground as rain as ground
temperatures should remain generally in the 3-6C degree range. High
temperatures today will struggle to get out of the 40s with readings
near 50F degrees possible near the NE/KS border.
For tonight, precipitation should be east of the area by midnight
with cloud cover quickly diminishing through the overnight hours.
These clearing skies combined with already cool temperatures will
allow for some decent radiational cooling and low temperatures
plummeting into the middle 30s and possibly even into the lower 30s
in some of the valleys. These conditions, combined with light
westerly winds will provide the potential for some patchy frost
across the entire CWA early Saturday morning.
.LONG TERM...(Saturday through Thursday)
Issued at 420 AM CDT FRI OCT 18 2013
The mid and long term time frame will be dominated by long wave
troughing over the Great Lakes region with fast, cold north to
northwest flow over the northern half of the Plains. Short wave
troughs will frequently move through the flow pattern, and while
the bulk of lift and moisture with these systems will be focused
northeast of the local forecast area, each trough will bring a
cold front through Kansas with reinforcing cold air. One of these
fast moving troughs appears that it will focus its energy a bit
farther southwest, closer to the local forecast area, on Tuesday.
Have added a slight chance of rain on Tuesday for this system, but
the remainder of the forecast is dry at this time.
Saturday and Sunday may be the warmest days of the coming week
with highs in the 60s as a period of warm advection is expected in
advance of a late Sunday cold front. Otherwise, expect high
temperatures only in the 50s on Monday through Wednesday, and
perhaps back into the lower 60s by the end of the week. There may
also be several chances for frost, or even freezing temperatures.
The primary uncertainty in forecasting a solid freeze on any given
night lies in the timing of the fast moving short wave troughs
and their impact on night time winds and cloud cover. Tuesday,
Wednesday, or Thursday morning all appear to be fine candidates
for a frost or freeze, if skies clear and winds become calm, but
model guidance is currently out of phase regarding timing of the
cold fronts and surface high pressure beyond Monday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Saturday Afternoon)
Issued at 1224 PM CDT FRI OCT 18 2013
NAM forecast soundings show only about the lowest 1000 ft above
freezing through the afternoon, so there remains the possibility
for mixed precip. RAP and HRRR are in reasonable agreement in the
precip pushing east of TOP and FOE around 00Z. For the most part,
think conditions will be VFR unless some Mixed precip moves in
temporarily lowering CIGS and VSBY to MVFR. Once the precip ends,
Conditions should be VFR with dry air and subsidence increasing
behind the upper wave.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...Hennecke
LONG TERM...Barjenbruch
AVIATION...Wolters
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1233 PM EDT FRI OCT 18 2013
.SYNOPSIS...
HIGH PRESSURE BUILDS BACK ACROSS THE AREA THROUGH SATURDAY BEFORE
A COLD FRONT BRINGS SHOWERS AND A SHOT OF COLDER AIR SATURDAY NIGHT.
HIGH PRESSURE BUILDS EAST THROUGH MONDAY BEFORE ANOTHER STRONGER
FRONT CROSSES THE AREA LATE TUESDAY. UNSETTLED WEATHER WILL
CONTINUE THROUGH THE END OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.UPDATE...
POPS HAVE BEEN DECREASED DRASTICALLY AS LEAST OF THE PRECIPITATION
MOVES OUT OF THE AREA. TEMPERATURES HAVE REACHED THE MID 60S WHERE
SUBSIDENCE WAS LOCATED THIS MORNING. THIS AREA IS NOW BECOMING
INCREASINGLY CLOUDY WITH COLD AIR STRATOCUMULUS AND SOME FAIR
WEATHER CUMULUS. MORE CLOUDY LOCATIONS ARE IN THE MID TO UPPER
50S. HAVE ADJUSTED TEMPERATURES SLIGHTLY FOR CURRENT TRENDS.
&&
.PREVIOUS DISCUSSION...
LATEST HRRR MODEL RUN CONTINUES TO SHOW THE SHOWER ACTIVITY
RAPIDLY EXITING THE FORECAST AREA THIS MORNING. ANY REMAINING
PRECIPITATION LIES EAST OF THE ME/NH LINE AS OF 11Z. WILL ADJUST
PROBABILITY OF PRECIPITATION ACCORDINGLY. WILL ALSO ALLOW FOR
ADJUSTMENTS TO THE WIND FIELDS AS DRAINAGE WINDS CONTINUE NORTH
AND EAST OF PORTLAND. FOG CONTINUES ACROSS THE REGION AS
WELL...HOWEVER VISIBILITIES WILL SLOWLY IMPROVE WITH TIME EARLY
THIS MORNING.
WITH COLD AIR ADVECTION AND INCREASING MIXING VALUES...WINDS MAY BE
GUSTY AT TIMES. TEMPERATURES WILL STILL MANAGE TO MAKE IT INTO THE
60S IN MOST AREAS. USED A BLEND OF MET/MAV GUIDANCE FOR DAYTIME
MAXES THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
MAINLY CLEAR SKIES WILL CONTINUE DURING THE OVERNIGHT
PERIOD...WITH STILL SOME UPSLOPE CLOUDINESS IN THE WNW FACING
HIGHER TERRAIN. THERE WILL BE SOME PATCHY FOG IN THE MORE
SHELTERED VALLEYS.
A WEAK AND FAST MOVING RIDGE OF HIGH PRESSURE WILL CROSS NORTHERN
NEW ENGLAND EARLY SATURDAY MORNING. THIS WILL BE FOLLOWED BY A
DISTURBANCE EMBEDDED IN THE INCREASING SW FLOW ALOFT. CLOUDS WILL
BE ON THE INCREASE DURING THE DAY AS A WEAK AREA OF LOW PRESSURE
FORMS OFF THE MID ATLANTIC COAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE MOVES OFFSHORE SATURDAY AND ALLOWS A WARMER
SOUTHWEST FLOW TO DEVELOP ACROSS THE AREA SATURDAY IN ADVANCE OF
THE NEXT FRONTAL SYSTEM WHICH WILL MOVE THROUGH THE REGION
SATURDAY NIGHT. SCATTERED SHOWERS WILL SPREAD ACROSS THE REGION
LATE SATURDAY AND SAT NIGHT IN ADVANCE OF THE COLD FRONT.
HIGH PRESSURE QUICKLY BUILDS IN FOR SUNDAY AND MONDAY.
TEMPERATURES STAY NEAR SEASONAL NORMALS WITH A FAIR AMOUNT OF
SUNSHINE.
THE NEXT FRONT IS EXPECTED TO MOVE ACROSS THE REGION LATE
TUESDAY INTO TUESDAY NIGHT. SHOWERS ONCE AGAIN CAN BE EXPECTED
ALONG AND AHEAD OF THE FRONT. BEHIND THE FRONT A MUCH COLDER AIR
MASS WILL FILTER ACROSS THE AREA WITH SNOW SHOWERS IN THE
MOUNTAINS EXPECTED ON WEDNESDAY. BY WED NIGHT OR THU NIGHT FROST
OR FREEZING CONDITIONS ARE EXPECTED TO REACH THE COASTAL AREAS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES WILL REMAIN LOW THROUGH
DAYBREAK AS A COLD FRONT PUSHES THROUGH. MANY SITES WILL SEE
IFR/LIFR CONDITIONS BETWEEN 08Z AND 14Z. CONDITIONS WILL RAPIDLY
IMPROVE THEREAFTER.
LONG TERM...
VFR SATURDAY. COULD SEE MVFR/IFR IN SHOWERS SATURDAY NIGHT.
SHOULD BE VFR AGAIN SUNDAY THROUGH EARLY TUESDAY.
&&
.MARINE...
SHORT TERM...SCA CONTINUES AND HAS BEEN EXTENDED THROUGH TONIGHT...AS
A COLD FRONTAL PASSAGE INCREASES WIND GUSTS AND WAVE HEIGHTS.
LONG TERM...
WINDS/SEAS TO REMAIN BLO SCA CONDS THROUGH MONDAY. WINDS/SEAS WILL
INCREASE AND REACH SCA CONDS TUES DUE TO AN INCRG SLY GRADIENT AHEAD
OF AN APPROACHING CDFNT. THE COLD FRONT MOVES ACROSS THE WATERS
TUES NIGHT WITH GSTY WLY WINDS BEHIND THE FROPA THAT WILL CONTINUE
THROUGH WED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ150-152-
154.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION
NWS GRAY ME
652 AM EDT FRI OCT 18 2013
.SYNOPSIS...
HIGH PRESSURE BUILDS BACK ACROSS THE AREA THROUGH SATURDAY BEFORE
A COLD FRONT BRINGS SHOWERS AND A SHOT OF COLDER AIR SATURDAY NIGHT.
HIGH PRESSURE BUILDS EAST THROUGH MONDAY BEFORE ANOTHER STRONGER
FRONT CROSSES THE AREA LATE TUESDAY. UNSETTLED WEATHER WILL
CONTINUE THROUGH THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
LATEST HRRR MODEL RUN CONTINUES TO SHOW THE SHOWER ACTIVITY
RAPIDLY EXITING THE FORECAST AREA THIS MORNING. ANY REMAINING
PRECIPITATION LIES EAST OF THE ME/NH LINE AS OF 11Z. WILL ADJUST
PROBABILITY OF PRECIPITATION ACCORDINGLY. WILL ALSO ALLOW FOR
ADJUSTMENTS TO THE WIND FIELDS AS DRAINAGE WINDS CONTINUE NORTH
AND EAST OF PORTLAND. FOG CONTINUES ACROSS THE REGION AS
WELL...HOWEVER VISIBILITIES WILL SLOWLY IMPROVE WITH TIME EARLY
THIS MORNING.
HYDRO SITUATION FOR THE GORHAM DAM...
HAVE EXTENDED THE FLASH FLOOD WATCH FOR THE GORHAM AREA FOR A
COUPLE MORE HOURS THIS MORNING AS WE AWAIT NEW INFORMATION ON THE
GORHAM DAM. FLASH FLOOD WATCH IS NOW IN EFFECT UNTIL 9 AM.
PREV DISC...
A FAST MOVING AREA OF LOW PRESSURE WILL RACE EAST OF OUR REGION
THIS MORNING. THIS WILL ALLOW FOR CLEARING SKIES INITIALLY OVER
DOWNSLOPE AREAS...FOLLOWED BY SLOW CLEARING IN THE MOUNTAINS.
WITH COLD AIR ADVECTION AND INCREASING MIXING VALUES...WINDS MAY BE
GUSTY AT TIMES. TEMPERATURES WILL STILL MANAGE TO MAKE IT INTO THE
60S IN MOST AREAS. USED A BLEND OF MET/MAV GUIDANCE FOR DAYTIME
MAXES THIS AFTERNOON.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
MAINLY CLEAR SKIES WILL CONTINUE DURING THE OVERNIGHT
PERIOD...WITH STILL SOME UPSLOPE CLOUDINES IN THE WNW FACING
HIGHER TERRAIN. THERE WILL BE SOME PATCHY FOG IN THE MORE
SHELTERED VALLEYS.
A WEAK AND FAST MOVING RIDGE OF HIGH PRESSURE WILL CROSS NORTHERN
NEW ENGLAND EARLY SATURDAY MORNING. THIS WILL BE FOLLOWED BY A
DISTURBANCE EMBEDDED IN THE INCREASEING SW FLOW ALOFT. CLOUDS WILL
BE ON THE INCREASE DURING THE DAY AS A WEAK AREA OF LOW PRESSURE
FORMS OFF THE MID ATLANTIC COAST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE MOVES OFFSHORE SATURDAY AND ALLOWS A WARMER SOUTHWEST
FLOW TO DEVELOP ACROSS THE AREA SATURDAY IN ADVANCE OF THE NEXT FRONTAL
SYSTEM WHICH WILL MOVE THROUGH THE REGION SATURDAY NIGHT.
SCATTERED SHOWERS WILL SPREAD ACROSS THE REGION LATE SATURDAY AND
SAT NIGHT IN ADVANCE OF THE COLD FRONT.
HIGH PRESSURE QUICKLY BUILDS IN FOR SUNDAY AND MONDAY.
TEMPERATURES STAY NEAR SEASONAL NORMALS WITH A FAIR AMOUNT OF
SUNSHINE.
THE NEXT FRONT IS EXPECTED TO MOVE ACROSS THE REGION LATE
TUESDAY INTO TUESDAY NIGHT. SHOWERS ONCE AGAIN CAN BE EXPECTED
ALONG AND AHEAD OF THE FRONT. BEHIND THE FRONT A MUCH COLDER AIR
MASS WILL FILTER ACROSS THE AREA WITH SNOW SHOWERS IN THE
MOUNTAINS EXPECTED ON WEDNESDAY. BY WED NIGHT OR THU NIGHT FROST
OR FREEZING CONDITIONS ARE EXPECTED TO REACH THE COASTAL AREAS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES WILL REMAIN LOW THROUGH
DAYBREAK AS A COLD FRONT PUSHES THROUGH. MANY SITES WILL SEE
IFR/LIFR CONDITIONS BETWEEN 08Z AND 14Z. CONDITIONS WILL RAPIDLY
IMPROVE THEREAFTER.
LONG TERM...
VFR SATURDAY. COULD SEE MVFR/IFR IN SHOWERS SATURDAY
NIGHT. SHOULD BE VFR AGAIN SUNDAY THROUGH EARLY TUESDAY.
&&
.MARINE...
SHORT TERM...SCA CONTINUES AND HAS BEEN EXTENDED THROUGH TONIGHT...AS
A COLD FRONTAL PASSAGE INCREASES WIND GUSTS AND WAVE HEIGHTS.
LONG TERM...
WINDS/SEAS TO REMAIN BLO SCA CONDS THROUGH MONDAY. WINDS/SEAS WILL
INCREASE AND REACH SCA CONDS TUES DUE TO AN INCRG SLY GRADIENT AHEAD
OF AN APPROACHING CDFNT. THE COLD FRONT MOVES ACROSS THE WATERS
TUES NIGHT WITH GSTY WLY WINDS BEHIND THE FROPA THAT WILL CONTINUE
THROUGH WED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...FLASH FLOOD WATCH UNTIL 9 AM EDT THIS MORNING FOR NHZ002.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ150-152-
154.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
828 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT CROSSES THE REGION AND MOVES OFF THE COAST OVERNIGHT.
HIGH PRESSURE SETTLES OVER THE MID ATLANTIC STATES SUNDAY AND
MOVES OFF THE COAST MONDAY. ANOTHER COLD FRONT WILL MOVE THROUGH
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
UPPER LEVEL ANALYSIS HAS A LONG WAVE TROUGH FROM CENTRAL CANADA
SOUTH THROUGH THE MISSISSIPPI VALLEY. SOUTHERN JET STREAM FROM
LOUISIANA TO THE MID ATLANTIC COAST WAS BRINGING MID LEVEL MOISTURE
ACROSS THE CWA. A COLD FRONT EXTENDED FROM LOW PRESSURE OVER THE
NORTHERN GREAT LAKES SOUTH THROUGH EASTERN OHIO AND INTO
MISSISSIPPI. A STATIONARY FRONT EXTENDED ALONG THE CAROLINA COAST
SOUTHWEST INTO THE GULF OF MEXICO.
THE MID LEVEL MOISTURE IN COMBINATION WITH A WEAK SURFACE/LOW LEVEL
TROUGH OVER EASTERN WV WAS RESULTING IN SCATTERED VERY LIGHT SHOWERS
ACROSS MUCH OF THE CWA. MODELS HAVE HANDLED THIS ACTIVITY RATHER
POORLY BUT THE RUC SEEMS TO HAVE THE BEST HANDLE ON IT CURRENTLY.
STARTING THE FORECAST THROUGH 00Z WITH AT LEAST 30 PERCENT POPS.
PCPN AMOUNTS WILL CONTINUE TO BE QUITE LIGHT...GENERALLY A FEW
HUNDREDTHS OF AN INCH AT THE MOST. DRIER AIR WILL GRADUALLY FILTER
IN FROM THE SW WITH A CHC FOR PCPN CONTINUING OVER NORTHERN PORTIONS
TIL 04Z AHEAD OF THE COLD FRONT.
THE COLD FRONT WILL BEGIN TO PASS THROUGH SHORTLY AFTER MIDNIGHT AND
REACH THE COAST BY AROUND 4 AM EDT. THIS WILL BRING SHARP CLEARING
AND SWEEP MUCH OF THE MOISTURE OFF TO THE EAST.
KEPT HOURLY TEMPERATURES ELEVATED THIS EVENING FROM A NORMAL DIURNAL
CURVE THEN LOWERED THEM MORE QUICKLY FOLLOWING THE FRONTAL PASSAGE.
MAINLY USED THE SREF FOR LOW TEMPERATURES SUNDAY MORNING WHICH
VERIFIED WELL FRIDAY MORNING. LOWS ARE FORECAST TO RANGE FROM THE
LWR 40S ACROSS THE PIEDMONT TO MID AND UPR 50S IN THE SE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SFC HIGH PRESSURE PERSISTS THROUGH SUNDAY/SUNDAY NIGHT AND SLIDES
OFFSHORE ON MONDAY. A MOSTLY CLEAR SKY AND COOL TEMPERATURES WILL
PERSIST. WITH HIGH PRESSURE OVER THE AREA SUNDAY...SUBSIDENCE WILL
HOLD TEMPERATURES DOWN FROM THEIR POTENTIAL. HIGHS ARE FORECAST TO
RANGE FROM AROUND 60 IN THE NORTHERN NECK AND THE MD EASTERN SHORE
TO THE MID 60S ALONG THE NC BORDER.
IDEAL RADIATIONAL COOLING WILL THEN BRING THE COOLEST NIGHT SO FAR
THIS SEASON. LOWS MONDAY MORNING RANGE FROM THE UPR 30S WELL INLAND
TO THE MID 40S AT THE COAST.
AS HIGH PRESSURE SLIDES OFF THE COAST...TEMPERATURES WARM A BIT
MONDAY WITH HIGHS IN THE MID TO UPR 60S. WITH THE SOUTHERLY WINDS
AND AN INCREASE IN CLOUDINESS...LOW TEMPERATURES WILL BE MILDER
TUESDAY MORNING...RANGING FROM THE MID 40S INLAND TO THE MID 50S
NEAR THE COAST.
DUE TO LOW PRESSURE DEVELOPMENT ON THE FRONT OFF THE CAROLINA
COAST...THERE IS A SLIGHT TO LOW CHC FOR RAIN OVER SE PORTIONS.
THERE IS UNCERTAINTY AS TO WHETHER THIS WILL EVEN MAKE IT INTO OUR
AREA. FOR NOW HAVE A 30 PERCENT CHANCE FOR SHOWERS NEAR THE
ALBEMARLE SOUND WITH 20 PERCENT POPS INTO SOUTHEAST VIRGINIA. HIGH
TEMPERATURES ACROSS THE AREA ON TUESDAY RANGE FROM 65 TO 70.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
WILL LEAN TOWARD THE 12Z ECMWF MODEL FOR THE EXTENDED PERIOD.
ANOTHER SRN STREAM WEAK LO PRES AREA WILL MOVE OFF THE SE AND MID
ATLC CST LATE TUE INTO WED MORNG...FOLLOWED BY A COLD FRONT
PUSHING OFF THE CST BY WED EVENG. THIS SCENARIO WILL PROVIDE A
SLGT CHC OR SML CHC FOR SHOWERS ACRS THE AREA. THEN...A VERY
DRY/COOL AIRMASS WILL DOMINATE THE REGION WED NGT THRU SAT...AS HI
PRES WILL BLD TWD AND INTO THE AREA FM THE W. MIN TEMPS WILL RANGE
FM THE LWR 40S TO LWR 50S WED MORNG...IN THE UPR 30S TO MID 40S
THU MORNG...AND MAINLY IN THE MID 30S TO LWR 40S FRI AND SAT
MORNGS. MAX TEMPS WILL MAINLY RANGE FM THE UPR 50S TO MID 60S THRU
THE PERIOD.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
MOISTURE FROM DEPARTING LOW PRESSURE OFF THE MID ATLANTIC COAST
AND AHEAD OF APPROACHING COLD FRONT HAS RESULTED IN SPORADIC IFR
CIGS PAST FEW HOURS ALONG WITH AREAS OF LIGHT RAIN. EXPECT THESE
CONDITIONS TO CONTINUE FOR THE NEXT 1-3 HRS EAST OF I-95 BEFORE
WINDS TURN MORE SW AHEAD OF THE FRONT. EXPECT DECREASING
CLOUDINESS ALONG WITH A WIND SHIFT TO THE N LATE TONIGHT.
OUTLOOK...VFR CONDITIONS EXPECTED SUN AND MON AS HIGH PRESSURE
BUILDS INTO THE AREA. ANOTHER WEAK SYSTEM PASSES OFF THE NC COAST
TUE AND COULD BRING CIGS DOWN TO 3K FT OR LESS AT KECG/KORF.
&&
.MARINE...
WILL MAINTAIN SCA HEADLINES FOR ALL ZNS EXCEPT SRN TWO CSTL WTRS.
A COLD FRONT WILL PUSH OFF THE CST TNGT...AS HI PRES BLDS IN FM
THE W. SSW WINDS LESS THAN 15 KT WILL SHIFT TO THE NW LATE TNGT
AND INCREASE TO 15 TO 25 KT...WITH GUSTS TO AROUND 30 KT BY SUN
MORNG. THIS NW OR N SURGE WILL LAST THRU SUN MORNG...THEN DIMINISH
RATHER QUICKLY SUN AFTN...AS SFC HI PRES BLDS RIGHT OVR THE AREA.
FAIRLY QUIET SUN NGT INTO TUE...AS FCST AREA WILL BE BETWEEN
ANOTHER SFC LO WELL TO THE S AND ANOTHER LO PRES SYSTEM MOVING
ACRS THE GRT LKS. A STRONG COLD FRONT WILL EVENTUALLY PUSH THRU
LATE WED/WED NGT...BRINGING ANOTHER ROUND OF SCA OR POSSIBLY EVEN
GALE CONDITIONS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO NOON EDT SUNDAY FOR
ANZ632>638-650-652-654.
SMALL CRAFT ADVISORY FROM 1 AM TO NOON EDT SUNDAY FOR ANZ630-
631.
&&
$$
SYNOPSIS...LSA
NEAR TERM...LSA
SHORT TERM...LSA
LONG TERM...TMG
AVIATION...MPR/DAP
MARINE...TMG
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
155 PM EDT FRI OCT 18 2013
.UPDATE...
ISSUED AT 1014 AM EDT FRI OCT 18 2013
SFC LOW CURRENTLY OVER EASTERN LK SUPERIOR BETWEEN CARIBOU ISLAND
AND WHITEFISH POINT. TROUGH EXTENDING WEST FROM THE LOW WITH NNW
WINDS ALREADY NEAR THE SHORE AT MQT AND PUSHING TOWARD MUNISING.
COOLING IN WAKE OF TROUGH IS SPILLING ACROSS LK SUPERIOR LEADING
TO INCREASING OVERWATER INSTABILITY. BASED ON H85 TEMPS FM RUC THE
DELTA T/S RIGHT NOW OVER LK SUPERIOR ARE 12-14C. SHOWERS STREAMING
IN OFF LK SUPERIOR BTWN MARQUETTE AND MUNISING ARE LIKELY A RESULT
OF INSTABILITY AND LOW-LEVEL CONVERGENCE. ELSEWHERE...WIDESPREAD
RAIN IS OCCURRING OVER MUCH OF THE NORTHERN CWA. RAIN AMOUNTS LIGHT
WITH AVAILABLE AUTOMATED STATIONS SHOWING ONLY A HUNDREDTH OR TWO IN
AN HOUR. AS SHORTWAVE TO THE WEST SLIDES ACROSS THROUGH EARLY THIS
AFTN AND INTERACTS WITH NNW CYCLONIC FLOW AND THE INCREASING
INSTABILITY...EXPECT SHOWERS OVER THE WEST TO INCREASE OVER THE
HIGHER TERRAIN. RUC13 MAY BE OVERDONE WITH ITS QPF AMOUNTS...BUT IS
PROBABLY ON THE RIGHT TRACK WITH AT LEAST THE AREAL DEPICTION. MAIN
ADJUSTMENT WAS TO INCREASE POPS ALL AREAS THROUGH THE MORNING FOR THE
WIDESPREAD LIGHT RAIN...THEN KEEP HIGHER POPS LONGER OVER THE WEST THIS
AFTN DUE TO THE LK EFFECT. PRECIP WILL TREND DOWN THIS EVENING AS SFC
TROUGH MOVES EAST OF THE AREA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EDT FRI OCT 18 2013
RAIN SHOWERS OVER THE WRN CWA AND PARTS OF MN AND WI ARE BEING
DRIVEN BY A COLD FRONT ALONG THE LEADING EDGE OF THE SHOWERS...SUCH
AS WHERE HIGHER RADAR REFLECTIVITIES AND GRADIENTS ARE OVER SCENTRAL
LAKE SUPERIOR/NCENTRAL UPPER MI AT THE CURRENT TIME /0730Z/. BEHIND
THE INITIAL COLD FRONTAL PRECIP...THE WIDESPREAD RAIN IS BEING
DRIVEN BY A SHORTWAVE NEAR MPX AND UPPER LEVEL HEIGHT FALLS FROM A
STRONG UPPER TROUGH PUSHING INTO THE REGION FROM THE N. EVEN WITH
SUB FREEZING 850MB TEMPS BEHIND THE COLD FRONT...THERE IS NO SNOW
BEING REPORTED AS LOW LEVEL TEMPS BELOW 850MB ARE TOO WARM FOR
FROZEN PRECIP TO MAKE IT TO THE GROUND. EXPECT BEST COVERAGE OF RAIN
TO BE OVER WRN UPPER MI THROUGH MOST OF THE MORNING AS THE COLD
FRONT OUTRUNS BEST UPPER LEVEL SUPPORT /KEEPING RAIN COVERAGE LOWER
AS THE FRONT MOVES E/ AND THE SHORTWAVE MOVES OVER WRN UPPER MI
AROUND 18Z.
BEHIND THE SHORTWAVE AND AHEAD OF THE UPPER TROUGH AXIS...A BRIEF
RIDGE PASSES THROUGH TONIGHT...WHICH SHOULD PROVIDE A LULL IN
PRECIP. HOWEVER...AFTER THE RIDGE PASSES...CONDITIONS BECOME MORE
FAVORABLE FOR LAKE EFFECT/ENHANCED PRECIP AS 850MB TEMPS WILL BE
AROUND -3C OVER THE RELATIVELY WARM 8-10C WATERS OF LAKE SUPERIOR
WITH NW LOW LEVEL WINDS. THINK THE INCREASE IN SHOWER COVERAGE WILL
BE LATE TONIGHT AFTER 03Z. WITH THE COLDER 850MB TEMPS...SOME SNOW
COULD MIX IN WITH THE RAIN LAT TONIGHT WHEN NEAR SFC TEMPS ARE
COOLER. STILL NOT EXPECTING ANY SNOWFALL ACCUMULATIONS IN THE SHORT
TERM..
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 507 AM EDT FRI OCT 18 2013
SATURDAY AND SATURDAY NIGHT...THE MODELS WERE IN REASONABLE
AGREEMENT IN DROPPING A SHORTWAVE INTO THE REGION WITH THE STRONGEST
850-500 MB QVECTOR CONV TO THE SOUTH OF UPPER MI. HOWEVER...THE
FORCING AHEAD OF THE SHRTWV ALONG WITH RELATIVELY STEEP 900-600 MB
LAPSE RATES WILL BE STRONG ENOUGH TO SUPPORT SCT/NMRS SHOWERS
SPREADING FROM WEST TO EAST THROUGH THE CWA. FCST SOUNDINGS SUGGEST
THAT A RAIN/SNOW MIX WILL BE POSSIBLE IN THE MORNING BEFORE DIURNAL
WARMING AND WEAK WAA CHANGES THE PCPN OVER TO RAIN. WITH MAINLY W OR
WNW WINDS BY SAT NIGHT AND 850 MB TEMPS DOWN TO AROUND -4C...THE BEST
CHANCE FOR ENHANCED SHOWERS ARE EXPECTED MAINLY OVER THE KEWEENAW AND
LOCATIONS EAST OF MUNISING.
SUN INTO MON...THE GFS AND ECMWF REMAINED IN GOOD AGREEMENT WITH A
STRONGER SHRTWV DROPPING TO THE SOUTH FROM NRN MANITOBA. AS THE
ASSOCIATED SFC LOW MOVES FROM WI TO ERN UPPER MI...AN AREA OF
285K-295 ISENTROPIC LIFT WILL SUPPORT AN AREA OF PCPN MOVING INTO SW
UPPER MI SUN AFTERNOON AND ACROSS THE CWA SUN NIGHT. FCST
SOUNDINGS...AND WET-BULB ZERO HEIGHTS SUPPORT POTENTIAL FOR
ACCUMULATING SNOW OVER THE HIGHER TERRAIN OF THE WEST HALF OF UPPER
MI. WITH ONLY LIGHT TO MODERATE SNOWFALL RATES EXPECTED...AND
RELATIVELY LOW SNOW/WATER RATIO VALUES AOB 10/1...ANY ACCUMULATIONS
SHOULD REMAIN MAINLY BELOW AN INCH. MODELS SHOWED GREATER
DIFFERENCES BY LATER MONDAY AS THE GFS WAS MORE AGGRESSIVE IN
DIGGING THE SHRTWV TO THE SOUTH ALLOWING LOW LEVEL WINDS TO VEER
MORE NRLY COMPARED TO THE ECMWF. EITHER SOLUTION SUGGESTS THAT WITH
DEEP MOISTURE AND CYCLONIC FLOW AND 850 MB TEMPS TO AROUND -6C...LAKE
ENHANCED PCPN WILL AFFECT THE NORTH HALF OF UPPER MI THROUGH MON
NIGHT. THERE SHOULD ALSO BE ENOUGH LOW LEVEL COLD AIR FOR SOME
ACCUMULATING SNOW...ESPECIALLY WHERE UPSLOPE NW TO NNW FLOW
PREVAILS. CONFIDENCE IN PCPN/SNOW AMOUNTS IS LOW GIVEN MODEL
DIFFERENCES WITH THE DETAILS OF LOW LEVEL WINDS.
TUE-THU...WITH THE MEAN LONG WAVE TROUGH POSITION REMAINING OVER THE
GREAT LAKES AND ERN CONUS...NW FLOW AND WEAK CLIPPER SHRTWVS ARE
EXPECTED TO MOVE THROUGH THE WRN LAKES. THIS WILL BRING PERIODS OF
LIGHT PCPN THAT WILL BE ENHANCED BY LAKE SUPERIOR AS 850 MB TEMPS
REMAIN IN THE -6C TO -9C RANGE. LOCATIONS FAVORED BY WNW TO NW FLOW
ARE LIKELY TO SEE THE GREATEST PCPN CHANCES. SOME ADDITIONAL
ACCUMULATING SNOW MAY BE POSSIBLE ALTHOUGH THE AS IS TYPICAL IN
EARLY SEASON LAKE EFFECT REGIMES...GRAUPEL WILL LIKELY ALSO BE MIXED
WITH ANY RAIN/SNOW SHOWERS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 152 PM EDT FRI OCT 18 2013
SHOWERS WITH VFR VSBY AND MVFR CIGS DIMINISH LATER TODAY AS LOW
PRESSURE MOVES TO THE EAST OF LK SUPERIOR. LOW CIGS MAY LINGER
THROUGH MUCH OF THE NIGHT BUT SHOULD SCATTER OUT LATER TONIGHT
AT CMX AND SAW. CLOUDS THICKEN ON SATURDAY WITH THE APPROACH
OF ANOTHER LOW PRESSURE SYSTEM. CONDITIONS WILL MAINLY STAY
VFR UNTIL LATER SATURDAY. SOME SHOWERS MAY START TO IMPACT IWD
BY LATE SATURDAY MORNING. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 507 AM EDT FRI OCT 18 2013
A TROUGH OF LOW PRESSURE AND ASSOCIATED COLD FRONT MOVING ACROSS
EASTERN LAKE SUPERIOR TODAY WILL SHIFT EASTWARD TODAY...WITH A BRIEF
RIDGE BUILDING BACK IN TONIGHT. WINDS JUST BEHIND THE FRONT MAY
BRIEFLY GUST TO 20 TO 30KTS FRIDAY INTO FRIDAY EVENING. DURING THE
DAY SATURDAY THROUGH MUCH OF SUNDAY ANOTHER AREA OF LOW PRESSURE
WILL APPROACH LAKE SUPERIOR...CAUSING THE PRESSURE GRADIENT TO
INCREASE ONCE AGAIN. THIS MAY CAUSE WINDS TO INCREASE TO 20 TO 30
KNOTS...ESPECIALLY SATURDAY NIGHT INTO SUNDAY. MONDAY NIGHT THROUGH
TUESDAY...ANOTHER...MORE INTENSE AREA OF LOW PRESSURE...IS SET TO
SHIFT INTO THE REGION ALLOWING WINDS TO INCREASE OVER THE LAKE ONCE
AGAIN. DURING THIS TIME FRAME WINDS MAY GUST TO NEAR GALES OF 35
KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...TITUS
LONG TERM...JLB
AVIATION...JLA
MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1016 AM EDT FRI OCT 18 2013
.UPDATE...
ISSUED AT 1014 AM EDT FRI OCT 18 2013
SFC LOW CURRENTLY OVER EASTERN LK SUPERIOR BETWEEN CARIBOU ISLAND
AND WHITEFISH POINT. TROUGH EXTENDING WEST FROM THE LOW WITH NNW
WINDS ALREADY NEAR THE SHORE AT MQT AND PUSHING TOWARD MUNISING.
COOLING IN WAKE OF TROUGH IS SPILLING ACROSS LK SUPERIOR LEADING
TO INCREASING OVERWATER INSTABILITY. BASED ON H85 TEMPS FM RUC THE
DELTA T/S RIGHT NOW OVER LK SUPERIOR ARE 12-14C. SHOWERS STREAMING
IN OFF LK SUPERIOR BTWN MARQUETTE AND MUNISING ARE LIKELY A RESULT
OF INSTABILITY AND LOW-LEVEL CONVERGENCE. ELSEWHERE...WIDESPREAD
RAIN IS OCCURRING OVER MUCH OF THE NORTHERN CWA. RAIN AMOUNTS LIGHT
WITH AVAILABLE AUTOMATED STATIONS SHOWING ONLY A HUNDREDTH OR TWO IN
AN HOUR. AS SHORTWAVE TO THE WEST SLIDES ACROSS THROUGH EARLY THIS
AFTN AND INTERACTS WITH NNW CYCLONIC FLOW AND THE INCREASING
INSTABILITY...EXPECT SHOWERS OVER THE WEST TO INCREASE OVER THE
HIGHER TERRAIN. RUC13 MAY BE OVERDONE WITH ITS QPF AMOUNTS...BUT IS
PROBABLY ON THE RIGHT TRACK WITH AT LEAST THE AREAL DEPICTION. MAIN
ADJUSTMENT WAS TO INCREASE POPS ALL AREAS THROUGH THE MORNING FOR THE
WIDESPREAD LIGHT RAIN...THEN KEEP HIGHER POPS LONGER OVER THE WEST THIS
AFTN DUE TO THE LK EFFECT. PRECIP WILL TREND DOWN THIS EVENING AS SFC
TROUGH MOVES EAST OF THE AREA. &&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EDT FRI OCT 18 2013
RAIN SHOWERS OVER THE WRN CWA AND PARTS OF MN AND WI ARE BEING
DRIVEN BY A COLD FRONT ALONG THE LEADING EDGE OF THE SHOWERS...SUCH
AS WHERE HIGHER RADAR REFLECTIVITIES AND GRADIENTS ARE OVER SCENTRAL
LAKE SUPERIOR/NCENTRAL UPPER MI AT THE CURRENT TIME /0730Z/. BEHIND
THE INITIAL COLD FRONTAL PRECIP...THE WIDESPREAD RAIN IS BEING
DRIVEN BY A SHORTWAVE NEAR MPX AND UPPER LEVEL HEIGHT FALLS FROM A
STRONG UPPER TROUGH PUSHING INTO THE REGION FROM THE N. EVEN WITH
SUB FREEZING 850MB TEMPS BEHIND THE COLD FRONT...THERE IS NO SNOW
BEING REPORTED AS LOW LEVEL TEMPS BELOW 850MB ARE TOO WARM FOR
FROZEN PRECIP TO MAKE IT TO THE GROUND. EXPECT BEST COVERAGE OF RAIN
TO BE OVER WRN UPPER MI THROUGH MOST OF THE MORNING AS THE COLD
FRONT OUTRUNS BEST UPPER LEVEL SUPPORT /KEEPING RAIN COVERAGE LOWER
AS THE FRONT MOVES E/ AND THE SHORTWAVE MOVES OVER WRN UPPER MI
AROUND 18Z.
BEHIND THE SHORTWAVE AND AHEAD OF THE UPPER TROUGH AXIS...A BRIEF
RIDGE PASSES THROUGH TONIGHT...WHICH SHOULD PROVIDE A LULL IN
PRECIP. HOWEVER...AFTER THE RIDGE PASSES...CONDITIONS BECOME MORE
FAVORABLE FOR LAKE EFFECT/ENHANCED PRECIP AS 850MB TEMPS WILL BE
AROUND -3C OVER THE RELATIVELY WARM 8-10C WATERS OF LAKE SUPERIOR
WITH NW LOW LEVEL WINDS. THINK THE INCREASE IN SHOWER COVERAGE WILL
BE LATE TONIGHT AFTER 03Z. WITH THE COLDER 850MB TEMPS...SOME SNOW
COULD MIX IN WITH THE RAIN LAT TONIGHT WHEN NEAR SFC TEMPS ARE
COOLER. STILL NOT EXPECTING ANY SNOWFALL ACCUMULATIONS IN THE SHORT
TERM..
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 507 AM EDT FRI OCT 18 2013
SATURDAY AND SATURDAY NIGHT...THE MODELS WERE IN REASONABLE
AGREEMENT IN DROPPING A SHORTWAVE INTO THE REGION WITH THE STRONGEST
850-500 MB QVECTOR CONV TO THE SOUTH OF UPPER MI. HOWEVER...THE
FORCING AHEAD OF THE SHRTWV ALONG WITH RELATIVELY STEEP 900-600 MB
LAPSE RATES WILL BE STRONG ENOUGH TO SUPPORT SCT/NMRS SHOWERS
SPREADING FROM WEST TO EAST THROUGH THE CWA. FCST SOUNDINGS SUGGEST
THAT A RAIN/SNOW MIX WILL BE POSSIBLE IN THE MORNING BEFORE DIURNAL
WARMING AND WEAK WAA CHANGES THE PCPN OVER TO RAIN. WITH MAINLY W OR
WNW WINDS BY SAT NIGHT AND 850 MB TEMPS DOWN TO AROUND -4C...THE BEST
CHANCE FOR ENHANCED SHOWERS ARE EXPECTED MAINLY OVER THE KEWEENAW AND
LOCATIONS EAST OF MUNISING.
SUN INTO MON...THE GFS AND ECMWF REMAINED IN GOOD AGREEMENT WITH A
STRONGER SHRTWV DROPPING TO THE SOUTH FROM NRN MANITOBA. AS THE
ASSOCIATED SFC LOW MOVES FROM WI TO ERN UPPER MI...AN AREA OF
285K-295 ISENTROPIC LIFT WILL SUPPORT AN AREA OF PCPN MOVING INTO SW
UPPER MI SUN AFTERNOON AND ACROSS THE CWA SUN NIGHT. FCST
SOUNDINGS...AND WET-BULB ZERO HEIGHTS SUPPORT POTENTIAL FOR
ACCUMULATING SNOW OVER THE HIGHER TERRAIN OF THE WEST HALF OF UPPER
MI. WITH ONLY LIGHT TO MODERATE SNOWFALL RATES EXPECTED...AND
RELATIVELY LOW SNOW/WATER RATIO VALUES AOB 10/1...ANY ACCUMULATIONS
SHOULD REMAIN MAINLY BELOW AN INCH. MODELS SHOWED GREATER
DIFFERENCES BY LATER MONDAY AS THE GFS WAS MORE AGGRESSIVE IN
DIGGING THE SHRTWV TO THE SOUTH ALLOWING LOW LEVEL WINDS TO VEER
MORE NRLY COMPARED TO THE ECMWF. EITHER SOLUTION SUGGESTS THAT WITH
DEEP MOISTURE AND CYCLONIC FLOW AND 850 MB TEMPS TO AROUND -6C...LAKE
ENHANCED PCPN WILL AFFECT THE NORTH HALF OF UPPER MI THROUGH MON
NIGHT. THERE SHOULD ALSO BE ENOUGH LOW LEVEL COLD AIR FOR SOME
ACCUMULATING SNOW...ESPECIALLY WHERE UPSLOPE NW TO NNW FLOW
PREVAILS. CONFIDENCE IN PCPN/SNOW AMOUNTS IS LOW GIVEN MODEL
DIFFERENCES WITH THE DETAILS OF LOW LEVEL WINDS.
TUE-THU...WITH THE MEAN LONG WAVE TROUGH POSITION REMAINING OVER THE
GREAT LAKES AND ERN CONUS...NW FLOW AND WEAK CLIPPER SHRTWVS ARE
EXPECTED TO MOVE THROUGH THE WRN LAKES. THIS WILL BRING PERIODS OF
LIGHT PCPN THAT WILL BE ENHANCED BY LAKE SUPERIOR AS 850 MB TEMPS
REMAIN IN THE -6C TO -9C RANGE. LOCATIONS FAVORED BY WNW TO NW FLOW
ARE LIKELY TO SEE THE GREATEST PCPN CHANCES. SOME ADDITIONAL
ACCUMULATING SNOW MAY BE POSSIBLE ALTHOUGH THE AS IS TYPICAL IN
EARLY SEASON LAKE EFFECT REGIMES...GRAUPEL WILL LIKELY ALSO BE MIXED
WITH ANY RAIN/SNOW SHOWERS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 745 AM EDT FRI OCT 18 2013
A SHORTWAVE MOVING THROUGH THE REGION THIS MORNING WILL CONTINUE TO
PRODUCE RAIN SHOWERS AND REDUCED CIGS. EXPECT A SLOW IMPROVING TREND
TODAY AND ESPECIALLY TONIGHT AS A WEAK RIDGE QUICKLY MOVES THROUGH.
PRECIPITATION AND REDUCED CIGS THEN MOVE BACK IN LATE IN THE
FORECAST PERIOD FROM THE W /JUST INCLUDED AT IWD AT THIS TIME/ AS AN
UPPER TROUGH MOVES INTO THE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 507 AM EDT FRI OCT 18 2013
A TROUGH OF LOW PRESSURE AND ASSOCIATED COLD FRONT MOVING ACROSS
EASTERN LAKE SUPERIOR TODAY WILL SHIFT EASTWARD TODAY...WITH A BRIEF
RIDGE BUILDING BACK IN TONIGHT. WINDS JUST BEHIND THE FRONT MAY
BRIEFLY GUST TO 20 TO 30KTS FRIDAY INTO FRIDAY EVENING. DURING THE
DAY SATURDAY THROUGH MUCH OF SUNDAY ANOTHER AREA OF LOW PRESSURE
WILL APPROACH LAKE SUPERIOR...CAUSING THE PRESSURE GRADIENT TO
INCREASE ONCE AGAIN. THIS MAY CAUSE WINDS TO INCREASE TO 20 TO 30
KNOTS...ESPECIALLY SATURDAY NIGHT INTO SUNDAY. MONDAY NIGHT THROUGH
TUESDAY...ANOTHER...MORE INTENSE AREA OF LOW PRESSURE...IS SET TO
SHIFT INTO THE REGION ALLOWING WINDS TO INCREASE OVER THE LAKE ONCE
AGAIN. DURING THIS TIME FRAME WINDS MAY GUST TO NEAR GALES OF 35
KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...TITUS
LONG TERM...JLB
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1257 PM CDT Fri Oct 18 2013
.UPDATE:
Issued at 1239 PM CDT Fri Oct 18 2013
Coverage of rain has continued to expand this morning across ern KS
with a finger extending into nw and n cntrl MO. This finger exist
due to strong frontogenetical forcing. This forcing is expected to
work east across ne MO and w cntrl IL this aftn and continue into
the evening before weakening. This will cause this band to
continue to work slowly east this aftn and then dsspt this
evening. By 3Z, the forcing shifts south along the I70 corridor
which will cause the rest of the precip shield to overspread the
rest of the CWA overnight. This caused a fairly significant change
in the fcst. POPs were shifted north and increased for this aftn.
The other fcst elements seemed to be in decent shape.
2%
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 320 AM CDT Fri Oct 18 2013
A weak cold front was moving through the region early this morning,
but its only effect across the LSX CWA will be a wind shift from
southwest to northwest after fropa.
Early morning water vapor imagery along with recent RAP analyses of
the 1.5 PVU surface both depict a positively tilted trough over the
central CONUS with a couple of stout disturbances sliding down the
western side of the trough. Increasing large scale ascent ahead of
these vorticity centers will support scattered rain showers from
this afternoon into tonight. Since it may take some time to saturate
the initially dry air mass, precipitation chances look higher after
19/00z compared to earlier in the afternoon.
Kanofsky
.LONG TERM: (Tonight through Thursday)
Issued at 320 AM CDT Fri Oct 18 2013
Precipitation threat overnight is expected to transition from very
light showers during the early evening attempting to stream east-
northeast from mid MO, to a broader area of rain developing over
the southeast half of the CWA during the overnight hours as
upstream shortwave begins to push into mid Mississippi Valley and
the large scale ascent is realized over the CWA. Believe the NAM is
too far southeast with its QPF in the 06-12z time frame, as almost
all over solutions have northern fringes of QPF north of STL.
While specifics may be a bit off, the 3 hourly PoP trends from the
03z SREF look very reasonable.
This rain should wind down late tonight or very early Saturday
morning over our southeast counties as shortwave exits to the
east. The brief cool-down in the wake of this feature will quickly
give way to WAA in advance of the next shortwave from late
Saturday afternoon, with fairly strong warming forecast over most
of the CWA from late Saturday night into Sunday. By Sunday
afternoon all short range models are forecasting at least 8C 850mb
temps over the CWA, with thermal ridge extending from southeast
Kansas into ne MO possibly pushing temps to around 10C. Given this
trend have upped temps about a category from going forecasts, and
most areas should push the 70 degree mark.
Heading into the medium range, upper level trof is forecast to
deepen over the eastern CONUS in the wake of the aforementioned
shortwave, and this will bring even colder air into the region for
the start of the new week. The airmass that pushes into the area
Monday night and Tuesday will be the coldest so far of this fall,
and its certainly possible that the growing season could come to an
end in some areas either Tuesday or Wednesday morning. However, the
frost threat will depend on timing of surface ridge and any clouds
that advect into the region on the fairly dirty northwest flow, and
specifics with both the high and clouds are not clear at this time.
Based on progged 850mb temps it appears that during the
Tuesday-Thursday time frame highs will only be in the 50s with lows
in the 30s.
At this time have kept PoPs in the slight chance range with the
passage of the cold front Sunday night and Monday due to very
limited moisture. Have also continued slight chance PoPs over the
area on Tuesday night as another weak shortwave drops into the area.
Truett
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1239 PM CDT Fri Oct 18 2013
A strong upper level disturbance will affect the terminals this
period. Clouds and eventually rain will overspread the area NW to
SE from late this aftn near KUIN to the STL metro area shortly
before midnight. The rain should last 3-6 hrs with skies clearing
fairly quickly after the rain ends. There is the potential for IFR
CIGS with the precip but am not confident on timing and coverage
to include attm. With recent rainfall and clearing skies prior to
sunrise, think there may be a limited fog potential. The potential
is limited due to winds in the 5-10 kt range and drier air moving
into the area behind the rain. KCOU and KUIN have the best chance
of seeing fog due to the time skies are expected to be clear prior
to sunrise. Uncertainties preclude mentioning attm.
Specifics for KSTL:
MVFR CIGS fcst/VFR VSBY fcst. Clouds will increase this aftn and
evening with rain beginning before midnight and lasting several
hours. Skies should clear around sunrise.
2%
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1232 PM CDT Fri Oct 18 2013
.SHORT TERM...(Today through Sunday Night)
Issued at 405 AM CDT FRI OCT 18 2013
Long wave troughing persisted across the central CONUS early this
morning, and this pattern appears locked in for the next couple of
weeks. Embedded within the the large scale dip, the third in a
recent sequence of shortwave impulses was tracking southward
through Wyoming, and remains on track to target the southern half of
the CWA later today.
Front Range, CO radar shows an impressive band of snow expanding over
NE Colorado, while satellite imagery shows mid cloud rapidly
expanding eastward across srn Nebraska and most of Kansas. These
trends suggest that the axis of strong elevated frontogenesis will
likely come in a bit further north than earlier progged. This is
supported by a northward shift in the 00Z model solutions and more
recently the hourly RAP output.
For today, cloud cover will quickly overspread the CWA from west to east
this morning. Forecast soundings and model cross sections show a
rapid top- down saturation as sloped 700-500mb frontogenesis
increases in response to large scale height falls isentropic ascent.
Despite clear skies presently, precipitation could begin over ern
KS/west central MO as early noon. As discussed yesterday, the sub-
cloud layer will initially be very dry while 850-700mb temperatures
fall sharply as the shortwave approaches. In fact, if not for the
boundary layer, we would likely be dealing with wet snow!
Nonetheless, once the rain begins, surface temps will immediately
respond to diabatic cooling and fall back through the 40s. Hourly
temperatures reflect a non-diurnal curve for the afternoon.
Precipitation should reach a local maximum between 18-00Z, steadily
shifting southward with time as a small 700-500mb jet streak develops
and shifts the axis of greatest mid level forcing. QPF amounts will
average between one and two tenths of an inch, generally along and
south of I-70.
The mid level trough axis will quickly pivot across the CWA
overnight, with skies gradually clearing from west to east. Temps
will fall into the mid 30s by daybreak, and although conditions are
not optimal for a widespread frost, the moist boundary layer and
diminishing winds could enhance the potential. Next shift may want to
consider headlines for all or portions of the region tonight.
After a chilly day Saturday, strengthening west winds will develop
south of a progressive shortwave trough moving across the Upper
Midwest. Strong low level warm advection will begin Saturday night
and continue into Sunday, with a deep layer Chinook component
expected to rapidly spread some mild air eastward across the Plains.
Given upward trends in 850mb temp progs, have bumped highs into the
upper 60s to around 70 for Sunday, and made a significant increase
to the surface winds/gusts over the srn half of the CWA.
A dry cold front will sweep across the area Sunday night, leading to a
very challenging low temperature forecast that hinges entirely on
where the front ends up by 8AM. Current forecast projects a near 15
degree gradient from mid 30s along the Iowa border to near 50 across
mid Missouri, and significant adjustments remain possible.
.LONG TERM...(Monday through Thursday)
Issued at 403 AM CDT FRI OCT 18 2013
Later half of the forecast will continue the cool trend as negative
height anomalies persist across the Lower Missouri River Valley
through much of next week. As Monday arrives a significant trough
will be digging in across the center of the nation providing cold air
from the Canadian Plains with plenty of opportunity to rush south
through the northern and central Plains. Resulting cold air with the
northwest flow will keep temperatures ranging below normal through
the week. This is supported by 850mb model output which advertises
subzero centigrade temperatures sweeping into the region Monday, and
again Wednesday behind a small shortwave trough zipping through the
flow. This should make for some cool fall conditions next week with
highs only the 50s expected Monday through Wednesday. As for
overnight low, a bit of a frost might be in the offing. Overnight
lows will drop into the 30s Tuesday, Wednesday and Thursday
mornings. Currently, areas along and north of highway 36 look to
have the greatest chance for seeing repeated frost. Otherwise, have
included a silent slight chance for showers Wednesday into Thursday.
Models continue to advertise a shortwave trough zipping through the
northwest flow mid-week, providing a little reinforcing shot of cold
air for Thursday mornings lows. Models might be over doing the
amount of moisture, thus confusing low cloud cover with QPF, though
disturbances in the northwest flow often squeeze some light
precipitation out across eastern Kansas or Missouri. Have left the
silent slight chance POPs characterized as showers for now, though if
confidence in Tuesdays quick shortwave improves some consideration
might be needed for including snow in the precipitation forecast.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1232 PM CDT FRI OCT 18 2013
Areas of light to moderate rain will spread northeast early this
afternoon, before beginning to push southeastward during the late
afternoon and evening hours. Although ceilings are expected to stay
VFR, visibilities could briefly drop below 5 miles in the heavier
rain. Precipitation should end from northwest to southeast between
00z and 03z, leaving behind VFR conditions and light winds tonight.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Bookbinder
LONG TERM...Cutter
AVIATION...Laflin
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
631 AM CDT Fri Oct 18 2013
.SHORT TERM: (Through Late This Afternoon)
Issued at 320 AM CDT Fri Oct 18 2013
A weak cold front was moving through the region early this morning,
but its only effect across the LSX CWA will be a wind shift from
southwest to northwest after fropa.
Early morning water vapor imagery along with recent RAP analyses of
the 1.5 PVU surface both depict a positively tilted trough over the
central CONUS with a couple of stout disturbances sliding down the
western side of the trough. Increasing large scale ascent ahead of
these vorticity centers will support scattered rain showers from
this afternoon into tonight. Since it may take some time to saturate
the initially dry air mass, precipitation chances look higher after
19/00z compared to earlier in the afternoon.
Kanofsky
.LONG TERM: (Tonight through Thursday)
Issued at 320 AM CDT Fri Oct 18 2013
Precipitation threat overnight is expected to transition from very
light showers during the early evening attempting to stream east-
northeast from mid MO, to a broader area of rain developing over
the southeast half of the CWA during the overnight hours as
upstream shortwave begins to push into mid Mississippi Valley and
the large scale ascent is realized over the CWA. Believe the NAM is
too far southeast with its QPF in the 06-12z time frame, as almost
all over solutions have northern fringes of QPF north of STL.
While specifics may be a bit off, the 3 hourly PoP trends from the
03z SREF look very reasonable.
This rain should wind down late tonight or very early Saturday
morning over our southeast counties as shortwave exits to the
east. The brief cool-down in the wake of this feature will quickly
give way to WAA in advance of the next shortwave from late
Saturday afternoon, with fairly strong warming forecast over most
of the CWA from late Saturday night into Sunday. By Sunday
afternoon all short range models are forecasting at least 8C 850mb
temps over the CWA, with thermal ridge extending from southeast
Kansas into ne MO possibly pushing temps to around 10C. Given this
trend have upped temps about a category from going forecasts, and
most areas should push the 70 degree mark.
Heading into the medium range, upper level trof is forecast to
deepen over the eastern CONUS in the wake of the aforementioned
shortwave, and this will bring even colder air into the region for
the start of the new week. The airmass that pushes into the area
Monday night and Tuesday will be the coldest so far of this fall,
and its certainly possible that the growing season could come to an
end in some areas either Tuesday or Wednesday morning. However, the
frost threat will depend on timing of surface ridge and any clouds
that advect into the region on the fairly dirty northwest flow, and
specifics with both the high and clouds are not clear at this time.
Based on progged 850mb temps it appears that during the
Tuesday-Thursday time frame highs will only be in the 50s with lows
in the 30s.
At this time have kept PoPs in the slight chance range with the
passage of the cold front Sunday night and Monday due to very
limited moisture. Have also continued slight chance PoPs over the
area on Tuesday night as another weak shortwave drops into the area.
Truett
&&
.AVIATION: (For the 12z TAFs through 12z Saturday Morning)
Issued at 620 AM CDT Fri Oct 18 2013
MVFR ceilings are possible at KUIN for the next couple of hours
based on upstream satellite and METAR trends however conditions
should return to VFR by mid-morning. VFR conditions are expected
elsewhere along with increasing clouds during the day. Light rain
showers will spread eastward towards the terminals tonight,
however no cig/vis restrictions are forecast at this time due to
the initially dry air mass and the anticipated light rain
intensity.
Specifics for KSTL: VFR through at least the first 6 hours and
probably longer, although clouds will be increasing throughout the
day. Light rain showers are expected to develop across central MO
later tonight and spread eastward towards KSTL. No cig/vis
restrictions are forecast at this time due to the initially dry
air mass and the anticipated light rain intensity.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
627 AM CDT Fri Oct 18 2013
.SHORT TERM...(Today through Sunday Night)
Issued at 405 AM CDT FRI OCT 18 2013
Long wave troughing persisted across the central CONUS early this
morning, and this pattern appears locked in for the next couple of
weeks. Embedded within the the large scale dip, the third in a
recent sequence of shortwave impulses was tracking southward
through Wyoming, and remains on track to target the southern half of
the CWA later today.
Front Range, CO radar shows an impressive band of snow expanding over
NE Colorado, while satellite imagery shows mid cloud rapidly
expanding eastward across srn Nebraska and most of Kansas. These
trends suggest that the axis of strong elevated frontogenesis will
likely come in a bit further north than earlier progged. This is
supported by a northward shift in the 00Z model solutions and more
recently the hourly RAP output.
For today, cloud cover will quickly overspread the CWA from west to east
this morning. Forecast soundings and model cross sections show a
rapid top- down saturation as sloped 700-500mb frontogenesis
increases in response to large scale height falls isentropic ascent.
Despite clear skies presently, precipitation could begin over ern
KS/west central MO as early noon. As discussed yesterday, the sub-
cloud layer will initially be very dry while 850-700mb temperatures
fall sharply as the shortwave approaches. In fact, if not for the
boundary layer, we would likely be dealing with wet snow!
Nonetheless, once the rain begins, surface temps will immediately
respond to diabatic cooling and fall back through the 40s. Hourly
temperatures reflect a non-diurnal curve for the afternoon.
Precipitation should reach a local maximum between 18-00Z, steadily
shifting southward with time as a small 700-500mb jet streak develops
and shifts the axis of greatest mid level forcing. QPF amounts will
average between one and two tenths of an inch, generally along and
south of I-70.
The mid level trough axis will quickly pivot across the CWA
overnight, with skies gradually clearing from west to east. Temps
will fall into the mid 30s by daybreak, and although conditions are
not optimal for a widespread frost, the moist boundary layer and
diminishing winds could enhance the potential. Next shift may want to
consider headlines for all or portions of the region tonight.
After a chilly day Saturday, strengthening west winds will develop
south of a progressive shortwave trough moving across the Upper
Midwest. Strong low level warm advection will begin Saturday night
and continue into Sunday, with a deep layer Chinook component
expected to rapidly spread some mild air eastward across the Plains.
Given upward trends in 850mb temp progs, have bumped highs into the
upper 60s to around 70 for Sunday, and made a significant increase
to the surface winds/gusts over the srn half of the CWA.
A dry cold front will sweep across the area Sunday night, leading to a
very challenging low temperature forecast that hinges entirely on
where the front ends up by 8AM. Current forecast projects a near 15
degree gradient from mid 30s along the Iowa border to near 50 across
mid Missouri, and significant adjustments remain possible.
.LONG TERM...(Monday through Thursday)
Issued at 403 AM CDT FRI OCT 18 2013
Later half of the forecast will continue the cool trend as negative
height anomalies persist across the Lower Missouri River Valley
through much of next week. As Monday arrives a significant trough
will be digging in across the center of the nation providing cold air
from the Canadian Plains with plenty of opportunity to rush south
through the northern and central Plains. Resulting cold air with the
northwest flow will keep temperatures ranging below normal through
the week. This is supported by 850mb model output which advertises
subzero centigrade temperatures sweeping into the region Monday, and
again Wednesday behind a small shortwave trough zipping through the
flow. This should make for some cool fall conditions next week with
highs only the 50s expected Monday through Wednesday. As for
overnight low, a bit of a frost might be in the offing. Overnight
lows will drop into the 30s Tuesday, Wednesday and Thursday
mornings. Currently, areas along and north of highway 36 look to
have the greatest chance for seeing repeated frost. Otherwise, have
included a silent slight chance for showers Wednesday into Thursday.
Models continue to advertise a shortwave trough zipping through the
northwest flow mid-week, providing a little reinforcing shot of cold
air for Thursday mornings lows. Models might be over doing the
amount of moisture, thus confusing low cloud cover with QPF, though
disturbances in the northwest flow often squeeze some light
precipitation out across eastern Kansas or Missouri. Have left the
silent slight chance POPs characterized as showers for now, though if
confidence in Tuesdays quick shortwave improves some consideration
might be needed for including snow in the precipitation forecast.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 626 AM CDT FRI OCT 18 2013
VFR conditions will great the last day of the work week, however
these conditions might deteriorate as we transit the morning hours as
showers spread east across the region. Currently showers are expect
from east central Kansas through central Missouri around noon today.
This leaves the terminals in Kansas City with the highest potential
to see some rain with ceilings floating around the high end of the
MVFR range. Otherwise, northwest winds will adjust more to the
southwest behind the storms system that moves through today.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Bookbinder
LONG TERM...Cutter
AVIATION...Cutter
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
408 AM CDT Fri Oct 18 2013
.SHORT TERM...(Today through Sunday Night)
Issued at 405 AM CDT FRI OCT 18 2013
Long wave troughing persisted across the central CONUS early this
morning, and this pattern appears locked in for the next couple of
weeks. Embedded within the the large scale dip, the third in a
recent sequence of shortwave impulses was tracking southward
through Wyoming, and remains on track to target the southern half of
the CWA later today.
Front Range, CO radar shows an impressive band of snow expanding over
NE Colorado, while satellite imagery shows mid cloud rapidly
expanding eastward across srn Nebraska and most of Kansas. These
trends suggest that the axis of strong elevated frontogenesis will
likely come in a bit further north than earlier progged. This is
supported by a northward shift in the 00Z model solutions and more
recently the hourly RAP output.
For today, cloud cover will quickly overspread the CWA from west to east
this morning. Forecast soundings and model cross sections show a
rapid top- down saturation as sloped 700-500mb frontogenesis
increases in response to large scale height falls isentropic ascent.
Despite clear skies presently, precipitation could begin over ern
KS/west central MO as early noon. As discussed yesterday, the sub-
cloud layer will initially be very dry while 850-700mb temperatures
fall sharply as the shortwave approaches. In fact, if not for the
boundary layer, we would likely be dealing with wet snow!
Nonetheless, once the rain begins, surface temps will immediately
respond to diabatic cooling and fall back through the 40s. Hourly
temperatures reflect a non-diurnal curve for the afternoon.
Precipitation should reach a local maximum between 18-00Z, steadily
shifting southward with time as a small 700-500mb jet streak develops
and shifts the axis of greatest mid level forcing. QPF amounts will
average between one and two tenths of an inch, generally along and
south of I-70.
The mid level trough axis will quickly pivot across the CWA
overnight, with skies gradually clearing from west to east. Temps
will fall into the mid 30s by daybreak, and although conditions are
not optimal for a widespread frost, the moist boundary layer and
diminishing winds could enhance the potential. Next shift may want to
consider headlines for all or portions of the region tonight.
After a chilly day Saturday, strengthening west winds will develop
south of a progressive shortwave trough moving across the Upper
Midwest. Strong low level warm advection will begin Saturday night
and continue into Sunday, with a deep layer Chinook component
expected to rapidly spread some mild air eastward across the Plains.
Given upward trends in 850mb temp progs, have bumped highs into the
upper 60s to around 70 for Sunday, and made a significant increase
to the surface winds/gusts over the srn half of the CWA.
A dry cold front will sweep across the area Sunday night, leading to a
very challenging low temperature forecast that hinges entirely on
where the front ends up by 8AM. Current forecast projects a near 15
degree gradient from mid 30s along the Iowa border to near 50 across
mid Missouri, and significant adjustments remain possible.
.LONG TERM...(Monday through Thursday)
Issued at 403 AM CDT FRI OCT 18 2013
Later half of the forecast will continue the cool trend as negative
height anomalies persist across the Lower Missouri River Valley
through much of next week. As Monday arrives a significant trough
will be digging in across the center of the nation providing cold air
from the Canadian Plains with plenty of opportunity to rush south
through the northern and central Plains. Resulting cold air with the
northwest flow will keep temperatures ranging below normal through
the week. This is supported by 850mb model output which advertises
subzero centigrade temperatures sweeping into the region Monday, and
again Wednesday behind a small shortwave trough zipping through the
flow. This should make for some cool fall conditions next week with
highs only the 50s expected Monday through Wednesday. As for
overnight low, a bit of a frost might be in the offing. Overnight
lows will drop into the 30s Tuesday, Wednesday and Thursday
mornings. Currently, areas along and north of highway 36 look to
have the greatest chance for seeing repeated frost. Otherwise, have
included a silent slight chance for showers Wednesday into Thursday.
Models continue to advertise a shortwave trough zipping through the
northwest flow mid-week, providing a little reinforcing shot of cold
air for Thursday mornings lows. Models might be over doing the
amount of moisture, thus confusing low cloud cover with QPF, though
disturbances in the northwest flow often squeeze some light
precipitation out across eastern Kansas or Missouri. Have left the
silent slight chance POPs characterized as showers for now, though if
confidence in Tuesdays quick shortwave improves some consideration
might be needed for including snow in the precipitation forecast.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1130 PM CDT THU OCT 17 2013
Evening data packages show good continuity from previous model runs
and continue to spread an area of rain eastward across KS reaching
into west central MO around the noon hour. Best rain chances will be
along and south of the MO River with a high confidence of this
occurring. Made only minor changes on timing of rain into the KC
terminals with KSTJ remaining dry. Still anticipate a lowering of
VFR ceilings although the northern edge of MVFR ceilings could reach
as far north as KMKC. Won`t be able to make that decision until the
rain band sets up Friday morning.
Otherwise, after the rain exits west central MO by late afternoon
only expect VFR conditions with winds switching to the southwest
ahead of a fast moving surface trough. Could see some light rain move
into northwest MO Friday evening but not affect the terminals.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Bookbinder
LONG TERM...Cutter
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
324 AM CDT Fri Oct 18 2013
.SHORT TERM: (Through Late This Afternoon)
Issued at 320 AM CDT Fri Oct 18 2013
A weak cold front was moving through the region early this morning,
but its only effect across the LSX CWA will be a wind shift from
southwest to northwest after fropa.
Early morning water vapor imagery along with recent RAP analyses of
the 1.5 PVU surface both depict a positively tilted trough over the
central CONUS with a couple of stout disturbances sliding down the
western side of the trough. Increasing large scale ascent ahead of
these vorticity centers will support scattered rain showers from
this afternoon into tonight. Since it may take some time to saturate
the initially dry air mass, precipitation chances look higher after
19/00z compared to earlier in the afternoon.
Kanofsky
.LONG TERM: (Tonight through Thursday)
Issued at 320 AM CDT Fri Oct 18 2013
Precipitation threat overnight is expected to transition from very
light showers during the early evening attempting to stream east-
northeast from mid MO, to a broader area of rain developing over
the southeast half of the CWA during the overnight hours as
upstream shortwave begins to push into mid Mississippi Valley and
the large scale ascent is realized over the CWA. Believe the NAM is
too far southeast with its QPF in the 06-12z time frame, as almost
all over solutions have northern fringes of QPF north of STL.
While specifics may be a bit off, the 3 hourly PoP trends from the
03z SREF look very reasonable.
This rain should wind down late tonight or very early Saturday
morning over our southeast counties as shortwave exits to the
east. The brief cool-down in the wake of this feature will quickly
give way to WAA in advance of the next shortwave from late
Saturday afternoon, with fairly strong warming forecast over most
of the CWA from late Saturday night into Sunday. By Sunday
afternoon all short range models are forecasting at least 8C 850mb
temps over the CWA, with thermal ridge extending from southeast
Kansas into ne MO possibly pushing temps to around 10C. Given this
trend have upped temps about a category from going forecasts, and
most areas should push the 70 degree mark.
Heading into the medium range, upper level trof is forecast to
deepen over the eastern CONUS in the wake of the aforementioned
shortwave, and this will bring even colder air into the region for
the start of the new week. The airmass that pushes into the area
Monday night and Tuesday will be the coldest so far of this fall,
and its certainly possible that the growing season could come to an
end in some areas either Tuesday or Wednesady morning. However, the
frost threat will depend on timing of surface ridge and any clouds
that advect into the region on the fairly dirty northwest flow, and
specifics with both the high and clouds are not clear at this time.
Based on progged 850mb temps it appears that during the
Tuesday-Thursday time frame highs will only be in the 50s with lows
in the 30s.
At this time have kept PoPs in the slight chance range with the
passage of the cold front Sunday night and Monday due to very
limited moisture. Have also continued slight chance PoPs over the
area on Tuesday night as another weak shortwave drops into the area.
Truett
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1140 PM CDT Thu Oct 17 2013
VFR conditions will prevail thru the valid TAF period for most of
the sites. Exception is expected to be in KUIN where band of post-
frontal MVFR CIGs will affect the terminal late tonight and early
Friday morning. Otherwise, cold front over central IA and NW MO
will move thru the forecast area dry late tonight but will veer
surface winds from SW to W-NW. An approaching upper level
disturbance on Friday will result in increasing clouds in the
afternoon with light rain by late evening.
Specifics for KSTL: VFR conditions to prevail thru the valid
period. Surface winds will veer early Friday morning with a cold
front, expected to move thru dry, but will see clouds and rain
chances increase with approaching upper level disturbance late
Friday. Clouds and rain anticipated to exit before sunrise
Saturday morning.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1250 PM CDT FRI OCT 18 2013
.SYNOPSIS...
ISSUED AT 333 AM CDT FRI OCT 18 2013
H5 ANALYSIS FROM EARLIER THIS EVENING CONTINUES TO INDICATE A
LONGWAVE TROUGH OF LOW PRESSURE LOCATED ACROSS THE CONUS WITH
RIDGING OFF THE PACIFIC COAST OF THE US AND CANADA. RIDGING
EXTENDED FROM THE WESTERN ATLANTIC INTO GREENLAND. EMBEDDED
SHORTWAVES WERE NOTED ACROSS THE NORTHERN CONUS ATTM...WITH ONE
LOCATED OVER THE EASTERN DAKOTAS...AND A SECOND ACROSS THE
NORTHERN ROCKIES. THE SECOND FEATURE CONTINUES TO TRACK TO THE
SOUTH SOUTHEAST INTO WYOMING...COLORADO AND WESTERN PORTIONS OF
KANSAS THIS MORNING PER WV IMAGERY. ENHANCED FRONTOGENESIS ALONG
AN AXIS EXTENDING FROM CHEYENNE WYOMING INTO NWRN KS...HAS LED TO
RAIN AND SNOW SHOWERS ACROSS NERN COLORADO...SERN WYOMING...NWRN
KS...SWRN NEBRASKA AND THE SOUTHERN NEBRASKA PANHANDLE. ACROSS
SOUTHWESTERN NEBRASKA...SOME LIGHT SNOW WAS BEING REPORTED AT
IMPERIAL OVER THE PAST COUPLE OF HOURS...WITH ONLY A FEW
HUNDREDTHS OF AN INCH OF PRECIPITATION REPORTED. ELSEWHERE...COLD
TEMPERATURES WERE PRESENT ACROSS CENTRAL AND NORTH CENTRAL
NEBRASKA WITH 2 AM CDT READINGS RANGING FROM 25 AT BROKEN
BOW...TO 32 AT NORTH PLATTE AND ONEILL. VERY DRY AIR WAS IN PLACE
ACROSS NORTH CENTRAL NEBRASKA TONIGHT WITH DEW POINTS IN THE MID
20S. THIS DRY AIR EXTENDED WELL NORTH OF THE AREA INTO SOUTH
DAKOTA.
&&
.UPDATE...
ISSUED AT 1134 AM CDT FRI OCT 18 2013
UPDATE TO THE FORECAST TO ACCOUNT FOR THE CLEARING SKIES ACROSS
THE HEART OF THE SANDHILLS AND THE POTENTIAL OF LIGHT SHOWERS OF
RAIN ACROSS OUR FAR SOUTHWEST. UPSTREAM OBSERVATIONS/HIGHWAY CAMERAS AT
KSNY AND KIMB HAVE SHOWN -SN AT BOTH LOCATIONS AS INCREASING
CLOUDS INVADE FROM THE WEST WITH AN APPROACHING MID LEVEL WAVE.
THE HRRR WOULD SUGGEST THE PRECIPITATION THREAT ENDING ACROSS THE
SOUTHWEST AROUND 20Z...WILL GO WITH THIS IDEA. THE HRRR ALSO
INDICATES THE POTENTIAL OF ADDITIONAL -SHRA OR SPRINKLES LATER
THIS AFTERNOON FOR MUCH OF THE SANDHILLS REGION...IN AN
ATMOSPHERE CHARACTERIZED AS DRY BUT WITH STEEP LOWER LEVEL LAPSE
RATES. PREVIOUS FORECAST HAS THIS SITUATION HANDLED WELL WITH A
BROAD ISOLATED MENTION...THUS NO OTHER CHANGES NEEDED AT THIS
TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT FRI OCT 18 2013
THIS MORNING...PRECIPITATION WILL CONTINUE TO SHIFT TO THE SOUTH
AND EAST INTO EAST CENTRAL COLORADO AND NORTHERN KANSAS THROUGH
MIDDAY. AS OF FCST ISSUANCE TIME...THE NRN PERIPHERY OF
PRECIPITATION IS EXPECTED TO BE SOUTH OF THE NEBR PANHANDLE...AND
CONFINED TO PERKINS...CHASE...HAYES...WESTERN FRONTIER AND SWRN
LINCOLN COUNTIES. THIS AREA OF PCPN IS EXPECTED TO CLEAR THE SWRN
FCST AREA BY MID MORNING. FOR THE REST OF TODAY...A SECONDARY
SHORTWAVE WILL TRACK ACROSS THE DAKOTAS AND NEBRASKA THIS
AFTERNOON. INHERITED FORECAST HAD SLIGHT CHANCE POPS LATER THIS
MORNING AND THIS AFTERNOON ACROSS A LARGE CHUNK OF CENTRAL AND
NORTH CENTRAL NEBRASKA. DECIDED TO SCALE THIS BACK SOMEWHAT TO
MAINLY SPRINKLES...AND ISOLATED SHOWERS DURING THE MID TO LATE
AFTERNOON HOURS. FCST SOUNDINGS ACROSS THE CENTRAL AND NRN
CWA...CONTINUE TO INDICATE VERY DRY CONDS IN THE SURFACE TO
5000-7000 FT AGL LAYER...WITH LAYER PW`S A MERE .3 INCHES...SO
FEEL SPRINKLES ARE WARRANTED HERE. ACROSS FAR NORTHEASTERN
AREAS...WILL CONTINUE ISOLATED SHOWERS DURING THE MID TO LATE
AFTERNOON HOURS...AS STEEP LAPSE RATES REMAIN IN PLACE...AND
MOISTURE IS A LITTLE BETTER ACROSS THE NORTHEASTERN CWA. HIGHS
THIS AFTERNOON WILL RANGE FROM THE UPPER 40S IN THE
NORTHWEST...TO THE LOWER 50S ELSEWHERE. FOR TONIGHT...THE UPPER
LEVEL SHORTWAVE...WILL SLIDE EAST OF THE FORECAST AREA LEADING TO
CLEARING SKIES IN THE CENTRAL AND WEST...AS WELL AS COLD
TEMPERATURES. WITH DRY AIR IN PLACE AND FAIRLY LIGHT WESTERLY
WINDS...LOWS WILL BOTTOM OUT MID TO UPPER 20S IN THE
WEST...AROUND 30 IN THE CENTRAL AND LOWER 30S IN THE NORTHEAST
WHERE CLOUD COVER WILL BE MORE PREVALENT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 333 AM CDT FRI OCT 18 2013
SATURDAY AND SUNDAY THE EASTERN PAC RIDGE WILL SLOWLY SHIFT
ONSHORE AND BEGIN TO AMPLIFY...NOSING INTO WESTERN CANADA. FLOW
BECOMES NORTHWESTERLY THEN MORE NORTHERLY. A LONG WAVE TROUGH
WILL SET UP ACROSS THE GREAT LAKES REGION. THIS WILL BRING AN
ACTIVE PATTERN WITH SEVERAL DISTURBANCE TO MOVE ACROSS THE
NORTHERN PLAINS. TWO MAJOR CONCERNS WITH THE FORECAST FOR THE
WEEKEND INTO NEXT WEEK. AVAILABILITY OF MOISTURE IS ONE. 00Z KLBF
SOUNDING LAST NIGHT ONLY HAD 0.37 INCHES OF PWATS...AND NW FLOW
WILL CONTINUE TO LIMIT MOISTURE RETURN. EACH PASSING DISTURBANCE
WILL SEE STEEP LAPSE RATES AND POCKETS OF GOOD
FRONTOGENESIS...HOWEVER LACK OF MOISTURE IS EXPECTED TO RESULT IN
ONLY PASSING CLOUDS AND ISOLATE LIGHT RAIN/SNOW SHOWERS.
GENERALLY LIQUID DURING THE DAYTIME...WHILE OVERNIGHT MAY SEE A
MIX OF RAIN AND SNOW AS TEMPS DROP INTO THE LOWER TO MID 30S.
TIMING OF WAVES IS SUNDAY AND ANOTHER SUNDAY NIGHT INTO
MONDAY...FOLLOWED BY ONE MORE ON TUESDAY. THE RIDGE BY MID WEEK
WILL BEGIN TO PUSH THE WAVES FURTHER EAST AND SHOULD SEE DRY
CONDITIONS PREVAIL FOR REST OF THE WEEK. THE SECOND CONCERN
FOCUSES ON TEMPERATURES. COLD AIR WILL DEFINITELY BE DRAW OVER
THE GREAT LAKES...WHILE WARM AIR BUILDS ACROSS THE SW CONUS. THE
HIGH PLAINS WILL BE IN THE BATTLE GROUND WITH TEMPS HIGHLY
DEPENDENT ON CLOUD COVER AND THE WESTWARD PUSH OF THE COLD AIR.
THE MODELS ARE STRUGGLING WITH THE COLD AIR AT THE SFC NEXT
WEEK...EVIDENT BY THE LATEST MEX GUIDANCE. TUESDAY MOS GUIDANCE
TEMPS JUMPED FROM UPPER 40S TO LOWER 50S...TO THE LOWER AND MID
60S. OVER THE WEEKEND NOT EXPECTING TO MUCH VARIATION FROM MOS
GUIDANCE AS POCKETS OF CLOUDS TO KEEP HIGHS AT OR BELOW SEASONAL
NORMALS...MID TO UPPER 50S. BY MID WEEK...AS THE UPPER LEVEL
RIDGE INCREASES HEIGHTS...TEMPS SHOULD GO UP. WOULD BE MORE
CONCERNED ABOUT THE COLD AIR REMAINING IN PLACE IF THERE WAS A
SNOW PACK...HOWEVER WITH NOT SNOW WILL FAVOR A UPWARD TREND IN
THE FORECAST...TRENDING TOWARDS THE NEW GFS SOLUTION. STILL WOULD
LIKE TO SEE MORE CONSISTENCY WITH THE MODELS AS CONFIDENCE IS LOW
FOR THE MID NEXT WEEK FORECAST. TUESDAY AND WEDNESDAY MODEL 850
MB TEMPS HAVE A RANGE OF MORE THAN 10 DEGREES C AMONGST THE MANY
MEMBERS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1250 PM CDT FRI OCT 18 2013
AN UPPER LEVEL TROUGH OF LOW PRESSURE CONTINUES TO TRACK ACROSS
THE DAKOTAS TODAY...BRINGING INCREASING CLOUDINESS BACK ACROSS THE
SANDHILLS REGION OF NEBRASKA. THERE IS A SIGNAL FOR ISOLATED
SHOWERS THIS AFTERNOON...HOWEVER SHORT GUIDANCE IS SPLIT AS ENOUGH
DRY AIR IS IN PLACE TO LIMIT COVERAGE. THUS WILL MAINTAIN A DRY
FORECAST AT BOTH THE KLBF AND KVTN TERMINALS...AND UPDATE IF
NEEDED. WINDS TODAY WILL BE GUSTY AND OUT OF THE NORTHWEST...BUT
SHOULD WEAKEN OVERNIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JACOBS
SYNOPSIS...CLB
SHORT TERM...CLB
LONG TERM...MASEK
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1134 AM CDT FRI OCT 18 2013
.SYNOPSIS...
ISSUED AT 333 AM CDT FRI OCT 18 2013
H5 ANALYSIS FROM EARLIER THIS EVENING CONTINUES TO INDICATE A
LONGWAVE TROUGH OF LOW PRESSURE LOCATED ACROSS THE CONUS WITH
RIDGING OFF THE PACIFIC COAST OF THE US AND CANADA. RIDGING
EXTENDED FROM THE WESTERN ATLANTIC INTO GREENLAND. EMBEDDED
SHORTWAVES WERE NOTED ACROSS THE NORTHERN CONUS ATTM...WITH ONE
LOCATED OVER THE EASTERN DAKOTAS...AND A SECOND ACROSS THE
NORTHERN ROCKIES. THE SECOND FEATURE CONTINUES TO TRACK TO THE
SOUTH SOUTHEAST INTO WYOMING...COLORADO AND WESTERN PORTIONS OF
KANSAS THIS MORNING PER WV IMAGERY. ENHANCED FRONTOGENESIS ALONG
AN AXIS EXTENDING FROM CHEYENNE WYOMING INTO NWRN KS...HAS LED TO
RAIN AND SNOW SHOWERS ACROSS NERN COLORADO...SERN WYOMING...NWRN
KS...SWRN NEBRASKA AND THE SOUTHERN NEBRASKA PANHANDLE. ACROSS
SOUTHWESTERN NEBRASKA...SOME LIGHT SNOW WAS BEING REPORTED AT
IMPERIAL OVER THE PAST COUPLE OF HOURS...WITH ONLY A FEW
HUNDREDTHS OF AN INCH OF PRECIPITATION REPORTED. ELSEWHERE...COLD
TEMPERATURES WERE PRESENT ACROSS CENTRAL AND NORTH CENTRAL
NEBRASKA WITH 2 AM CDT READINGS RANGING FROM 25 AT BROKEN
BOW...TO 32 AT NORTH PLATTE AND ONEILL. VERY DRY AIR WAS IN PLACE
ACROSS NORTH CENTRAL NEBRASKA TONIGHT WITH DEW POINTS IN THE MID
20S. THIS DRY AIR EXTENDED WELL NORTH OF THE AREA INTO SOUTH
DAKOTA.
&&
.UPDATE...
ISSUED AT 1134 AM CDT FRI OCT 18 2013
UPDATE TO THE FORECAST TO ACCOUNT FOR THE CLEARING SKIES ACROSS
THE HEART OF THE SANDHILLS AND THE POTENTIAL OF LIGHT SHOWERS OF
RAIN ACROSS OUR FAR SOUTHWEST. UPSTREAM OBSERVATIONS/HIGHWAY CAMERAS AT
KSNY AND KIMB HAVE SHOWN -SN AT BOTH LOCATIONS AS INCREASING
CLOUDS INVADE FROM THE WEST WITH AN APPROACHING MID LEVEL WAVE.
THE HRRR WOULD SUGGEST THE PRECIPITATION THREAT ENDING ACROSS THE
SOUTHWEST AROUND 20Z...WILL GO WITH THIS IDEA. THE HRRR ALSO
INDICATES THE POTENTIAL OF ADDITIONAL -SHRA OR SPRINKLES LATER
THIS AFTERNOON FOR MUCH OF THE SANDHILLS REGION...IN AN
ATMOSPHERE CHARACTERIZED AS DRY BUT WITH STEEP LOWER LEVEL LAPSE
RATES. PREVIOUS FORECAST HAS THIS SITUATION HANDLED WELL WITH A
BROAD ISOLATED MENTION...THUS NO OTHER CHANGES NEEDED AT THIS
TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT FRI OCT 18 2013
THIS MORNING...PRECIPITATION WILL CONTINUE TO SHIFT TO THE SOUTH
AND EAST INTO EAST CENTRAL COLORADO AND NORTHERN KANSAS THROUGH
MIDDAY. AS OF FCST ISSUANCE TIME...THE NRN PERIPHERY OF
PRECIPITATION IS EXPECTED TO BE SOUTH OF THE NEBR PANHANDLE...AND
CONFINED TO PERKINS...CHASE...HAYES...WESTERN FRONTIER AND SWRN
LINCOLN COUNTIES. THIS AREA OF PCPN IS EXPECTED TO CLEAR THE SWRN
FCST AREA BY MID MORNING. FOR THE REST OF TODAY...A SECONDARY
SHORTWAVE WILL TRACK ACROSS THE DAKOTAS AND NEBRASKA THIS
AFTERNOON. INHERITED FORECAST HAD SLIGHT CHANCE POPS LATER THIS
MORNING AND THIS AFTERNOON ACROSS A LARGE CHUNK OF CENTRAL AND
NORTH CENTRAL NEBRASKA. DECIDED TO SCALE THIS BACK SOMEWHAT TO
MAINLY SPRINKLES...AND ISOLATED SHOWERS DURING THE MID TO LATE
AFTERNOON HOURS. FCST SOUNDINGS ACROSS THE CENTRAL AND NRN
CWA...CONTINUE TO INDICATE VERY DRY CONDS IN THE SURFACE TO
5000-7000 FT AGL LAYER...WITH LAYER PW`S A MERE .3 INCHES...SO
FEEL SPRINKLES ARE WARRANTED HERE. ACROSS FAR NORTHEASTERN
AREAS...WILL CONTINUE ISOLATED SHOWERS DURING THE MID TO LATE
AFTERNOON HOURS...AS STEEP LAPSE RATES REMAIN IN PLACE...AND
MOISTURE IS A LITTLE BETTER ACROSS THE NORTHEASTERN CWA. HIGHS
THIS AFTERNOON WILL RANGE FROM THE UPPER 40S IN THE
NORTHWEST...TO THE LOWER 50S ELSEWHERE. FOR TONIGHT...THE UPPER
LEVEL SHORTWAVE...WILL SLIDE EAST OF THE FORECAST AREA LEADING TO
CLEARING SKIES IN THE CENTRAL AND WEST...AS WELL AS COLD
TEMPERATURES. WITH DRY AIR IN PLACE AND FAIRLY LIGHT WESTERLY
WINDS...LOWS WILL BOTTOM OUT MID TO UPPER 20S IN THE
WEST...AROUND 30 IN THE CENTRAL AND LOWER 30S IN THE NORTHEAST
WHERE CLOUD COVER WILL BE MORE PREVALENT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 333 AM CDT FRI OCT 18 2013
SATURDAY AND SUNDAY THE EASTERN PAC RIDGE WILL SLOWLY SHIFT
ONSHORE AND BEGIN TO AMPLIFY...NOSING INTO WESTERN CANADA. FLOW
BECOMES NORTHWESTERLY THEN MORE NORTHERLY. A LONG WAVE TROUGH
WILL SET UP ACROSS THE GREAT LAKES REGION. THIS WILL BRING AN
ACTIVE PATTERN WITH SEVERAL DISTURBANCE TO MOVE ACROSS THE
NORTHERN PLAINS. TWO MAJOR CONCERNS WITH THE FORECAST FOR THE
WEEKEND INTO NEXT WEEK. AVAILABILITY OF MOISTURE IS ONE. 00Z KLBF
SOUNDING LAST NIGHT ONLY HAD 0.37 INCHES OF PWATS...AND NW FLOW
WILL CONTINUE TO LIMIT MOISTURE RETURN. EACH PASSING DISTURBANCE
WILL SEE STEEP LAPSE RATES AND POCKETS OF GOOD
FRONTOGENESIS...HOWEVER LACK OF MOISTURE IS EXPECTED TO RESULT IN
ONLY PASSING CLOUDS AND ISOLATE LIGHT RAIN/SNOW SHOWERS.
GENERALLY LIQUID DURING THE DAYTIME...WHILE OVERNIGHT MAY SEE A
MIX OF RAIN AND SNOW AS TEMPS DROP INTO THE LOWER TO MID 30S.
TIMING OF WAVES IS SUNDAY AND ANOTHER SUNDAY NIGHT INTO
MONDAY...FOLLOWED BY ONE MORE ON TUESDAY. THE RIDGE BY MID WEEK
WILL BEGIN TO PUSH THE WAVES FURTHER EAST AND SHOULD SEE DRY
CONDITIONS PREVAIL FOR REST OF THE WEEK. THE SECOND CONCERN
FOCUSES ON TEMPERATURES. COLD AIR WILL DEFINITELY BE DRAW OVER
THE GREAT LAKES...WHILE WARM AIR BUILDS ACROSS THE SW CONUS. THE
HIGH PLAINS WILL BE IN THE BATTLE GROUND WITH TEMPS HIGHLY
DEPENDENT ON CLOUD COVER AND THE WESTWARD PUSH OF THE COLD AIR.
THE MODELS ARE STRUGGLING WITH THE COLD AIR AT THE SFC NEXT
WEEK...EVIDENT BY THE LATEST MEX GUIDANCE. TUESDAY MOS GUIDANCE
TEMPS JUMPED FROM UPPER 40S TO LOWER 50S...TO THE LOWER AND MID
60S. OVER THE WEEKEND NOT EXPECTING TO MUCH VARIATION FROM MOS
GUIDANCE AS POCKETS OF CLOUDS TO KEEP HIGHS AT OR BELOW SEASONAL
NORMALS...MID TO UPPER 50S. BY MID WEEK...AS THE UPPER LEVEL
RIDGE INCREASES HEIGHTS...TEMPS SHOULD GO UP. WOULD BE MORE
CONCERNED ABOUT THE COLD AIR REMAINING IN PLACE IF THERE WAS A
SNOW PACK...HOWEVER WITH NOT SNOW WILL FAVOR A UPWARD TREND IN
THE FORECAST...TRENDING TOWARDS THE NEW GFS SOLUTION. STILL WOULD
LIKE TO SEE MORE CONSISTENCY WITH THE MODELS AS CONFIDENCE IS LOW
FOR THE MID NEXT WEEK FORECAST. TUESDAY AND WEDNESDAY MODEL 850
MB TEMPS HAVE A RANGE OF MORE THAN 10 DEGREES C AMONGST THE MANY
MEMBERS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 634 AM CDT FRI OCT 18 2013
AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL TRACK ACROSS THE
DAKOTAS AND NEBRASKA TODAY AND THIS EVENING...SPREADING ABUNDANT
MID LEVEL CLOUDINESS TO WESTERN AND NORTH CENTRAL NEBRASKA. FOR
THE KVTN TERMINAL...BROKEN CIGS AROUND 5000 FT AGL WILL BE
POSSIBLE THROUGH THIS AFTERNOON WITH BROKEN CIGS AROUND 10000 FT
AGL EXPECTED TONIGHT. FOR THE KLBF TERMINAL...BROKEN CIGS RANGING
FROM 7000 TO 15000 FT AGL ARE EXPECTED TODAY...WITH SCATTERED HIGH
CLOUDINESS POSSIBLE OVERNIGHT. WINDS TODAY WILL BE FROM THE WEST
NORTHWEST AT 10 TO 20 KTS...DECREASING TO UNDER 10 KTS TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JACOBS
SYNOPSIS...CLB
SHORT TERM...CLB
LONG TERM...MASEK
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1137 PM CDT THU OCT 17 2013
.AVIATION...06Z TAFS FOR KOMA...KLNK AND KOFK. VFR CONDITIONS
THROUGH THE PERIOD MID BROKEN MID DECK CLOUDS. COULD SEE A FEW
SPRINKLES AT ALL 3 TAF SITES...BY 22Z AT KOFK/KLNK AND 01Z AT
KOMA.
DEWALD
&&
.PREV DISCUSSION... /ISSUED 636 PM CDT THU OCT 17 2013/
AVIATION...00Z TAFS FOR KOMA...KLNK AND KOFK. MVFR CONDITIONS
PREVAIL EARLY IN THE TAF PERIOD...AND BIG QUESTION IS WHETHER
THESE LOWER CLOUDS WILL SCATTER OUT AS SURFACE HIGH PRESSURE
CONTINUES TO BUILD IN FROM THE WEST. OVERALL LOW CONFIDENCE ON
TIMING...BUT HAVE FORECAST 05Z...AND WILL ADJUST AS NECESSARY IF
CLOUDS DON`T SHOW ANY SIGNS OF BREAKING.
PREV DISCUSSION... /ISSUED 322 PM CDT THU OCT 17 2013/
SHORT TERM...TONIGHT THROUGH SUNDAY.
NORTHWESTERLY FLOW WITH A SERIES OF EMBEDDED WAVES WILL PREVAIL
OVER FORECAST AREA THROUGH THE WEEKEND WITH SOME WARMING EXPECTED.
FOR TONIGHT...FIRST IN SEVERAL WAVES WILL BE TRACKING FM DAKOTAS
INTO MINNESOTA SPREADING CLOUDS ACROSS AREA INTO EARLY TONIGHT
BEFORE PROBABLY DECREASING AFT 06Z. 18Z RAP AND 12Z 4KM WRF AND
SOME HOP WRF MEMBERS SUGGESTED SOME VERY LIGHT PRECIP COULD CLIP
NERN ZONES EARLY. ANOTHER WAVE MOVING TOWARD KS BY MORNING COULD
SPREAD SOME MID/HIGH CLOUDS TOWARD SRN AND ESPECIALLY SWRN ZONES
BY MORNING. THE VARIABLE CLOUDS...SOME WIND AND INITIALLY MODEST
DWPTS WL LEAD TO KEEPING MOST LOWS A BIT ABOVE GUIDANCE.
LITTLE CHANGE TO FRIDAY...KEPT IN SMALL POPS EXTREME SOUTH DUE TO
SRN WAVE...ALTHOUGH APPEARS BULK OF ANY PRECIP COULD REMAIN TO OUR
SOUTH. ALSO SHARP MID LVL TROUGH AXIS MOVING INTO ERN NEBRASKA
TOWARD 00Z COULD ALLOW SOME SHOWER DEVELOPMENT AS H5 TEMPS IN
MINUS UPPER 20S C MOVE OVER AREA. SPREAD SMALL CHANCES A BIT
FARTHER S. SOMEWHAT DISCOUNTED NAM IN DOWNSLOPE MOISTURE LACKING
FLOW BUT THIS COULD FACILITATE FUTURE CHANGES. DID TRIM TEMPS BACK
A FEW DEGREES DUE TO EXPECTED CLOUDS...BUT KEPT THEM ON HIGH SIDE
OF GUIDANCE.
AFTER TROUGH PASSES FRIDAY TEMPERATURES SHOULD BE WARMING SATURDAY
AND SUNDAY AHEAD OF A STRONGER WAVE THAT WILL ARRIVE LATE SUNDAY.
KEPT FORECAST DRY IN WARM ADVECTION AHEAD OF THIS WAVE...BUT CAN
NOT RULE OUT SOME NEED IN LATER FORECASTS. TRENDED MOST MAX
TEMPERATURES UPWARD BOTH DAYS TO REFLECT FORECAST H85 TEMPS...BUT
DIDN/T MIX TO THAT DEPTH DUE TO POSSIBLE CLOUDS.
CHERMOK
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY.
THE REGION WILL REMAIN IN NORTHWEST FLOW ALOFT AS A BROAD TROUGH
REMAINS IN PLACE TO OUR EAST WHILE AN AMPLIFIED RIDGE REMAINS OVER
THE WESTERN STATES. THIS WILL ALLOW A COLD CANADIAN AIRMASS TO DROP
INTO THE NORTHERN PLAINS AND UPPER MIDWEST. THERE CONTINUES TO BE
SOME DISAGREEMENT AS TO HOW FAR WEST THE COLD AIRMASS WILL
REACH...HOWEVER THE TREND CONTINUES TO BE COLD FOR NEXT WEEK WITH
HIGHS IN THE LOW 50S AND LOWS IN THE LOWER TO MID 30S. SOME WEAK
RECOVERY BY THURSDAY MAY BRING HIGHS UP INTO THE MID TO UPPER 50S.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1158 AM MDT FRI OCT 18 2013
.AVIATION...
18Z TAF CYCLE
EXPECTING MVFR/IFR CIGS FOR KTCC...KLVS AND REMAINDER OF EASTERN
PLAINS CENTRAL HIGHLANDS THROUGH LATE EVENING AS A SHALLOW BACKDOOR COLD
FRONT TRAVELS WSW TOWARD THE CENTRAL MTN CHAIN AND ACROSS THE SE
PLAINS. KABQ WILL EXPERIENCE BRIEF EASTERLY CANYON WINDS BETWEEN
03 AND 06Z. GUSTY NE WINDS BEHIND THE FRONT FOR KROW THIS
AFTERNOON. AS THE SFC HIGH SHIFTS SOUTHWEST LATE TONIGHT INTO
TOMORROW MORNING WINDS WILL DECREASE AS WEAKENING SFC HIGH TRAVELS
SE INTO SOUTHERN TX.
33
&&
.PREV DISCUSSION...330 AM MDT FRI OCT 18 2013...
SFC LOW/TROUGH ACROSS FAR EAST CENTRAL NM AND INTO THE ADJACENT
PORTION OF TX HAS CIRCULATED LOW LEVEL MOISTURE INTO SE NM WITH
ATTENDANT LOW CLOUDS/FOG OVER LEA/EDDY AND SE ROOSEVELT
COUNTIES...WHICH IS FARTHER WEST THAN WAS INDICATED 24 HRS AGO.
EXPECT THIS WILL MAKE A LITTLE MORE PROGRESS NORTH AND WWD BEFORE
THE COLD FRONT...CURRENTLY FROM CAO TO RTN...AND WITH IT/S
STRATUS...PUSHES FARTHER SOUTH. RUC INDICATES THE MOISTURE IN THE
SOUTHEAST SHOULD EXIT BY MID MORNING WHILE THE STRATUS CONTINUES TO
INVADE THE NE AND TO SOME EXTENT THE EAST CENTRAL. TODAY/S AREAL
COVERAGE OF POPS DIDN/T CHANGE MUCH FROM PREVIOUS MODEL RUNS.
FORECAST HIGHS HOWEVER DID COOL SEVERAL DEGREES IN THE NORTHEAST AND
EAST CENTRAL NO DOUBT IN PART TO THE EXTENSIVE LOW CLOUDS THAT MAY
LINGER THROUGH EARLY/MID AFTERNOON ACCORDING TO THE RUC. THE AREA
FROM RATON TO CLAYTON MAY NOT GET ANY WARMER THAN MID 40S...WHICH IS
20 TO 25 DEGREES BELOW NORMAL IF THE GUIDANCE IS CLOSE. OVERALL
HIGHS TODAY RANGE FROM NEAR NORMAL FAR SOUTHWEST TO 10 TO 15 DEGREES
BELOW AVERAGE FAR NORTHWEST TO THE FAR SOUTHEAST.
THE COOLER THAN AVERAGE HIGHS SET THE STAGE FOR POTENTIAL FOR NEAR
TO BELOW FREEZING LOWS TONIGHT. GUIDANCE FOR PORTIONS OF THE EAST
CENTRAL CLOSER TO THE TX BORDER AND ROW AREAS HAS COOLED A COUPLE
MORE DEGREES...SO A FREEZE WATCH WILL BE ISSUED. SOME LOW LEVEL
MOISTURE MAY BE PARKED ALONG THE EAST SLOPES OF THE CENTRAL MT CHAIN
THIS EVENING BUT DEWPOINTS STILL EVENTUALLY LOWER SUFFICIENTLY FOR
THE THREAT OF A FREEZE.
MODELS NOW INDICATE AT LEAST SOME POTENTIAL FOR AN EAST WIND TO
BREAK INTO THE MIDDLE RGV THIS EVENING...WHICH COMPLICATES A
FREEZE/NO FREEZE DECISION THAT MUCH MORE ESPECIALLY IN THE ABQ
METRO. CURRENT THOUGHTS ARE THE WIND COULD DIMINISH AFTER
MIDNIGHT...SO DECIDED TO ISSUE A FREEZE WATCH FOR THE MIDDLE AND
LOWER RGV AS WELL AS FOR THE UPPER TULAROSA VALLEY...WHERE SOME
LOCALES HAVE NOT YET FROZEN.
FOR THE REST OF THE WEEKEND...A WARMING TREND WILL COMMENCE WITH
HIGHS ACHIEVING NEAR NORMAL STATUS SUNDAY. ANOTHER FRONT COULD
ARRIVE IN THE EASTERN PLAINS AS SOON AS LATE SUNDAY...SO HIGHS WILL
BE KNOCKED DOWNWARD MONDAY. THIS FRONT LOOKS MORE LIKELY TO PRODUCE
AN EAST WIND INTO THE RGV EARLY MONDAY.
EXTENDED FORECAST MODEL TRENDS FOR MID TO LATE NEXT WEEK LEAN
TOWARDS MORE OF A RIDGE OVER NEW MEXICO. LATEST ECMWF DEPICTS A
DECENT SFC HIGH INVADING ERN NM DESPITE THE RIDGE WHILE THE GFS
LOCATES IT WELL TO THE EAST...WREAKING HAVOC ON FORECAST TEMPERATURE
DECISIONS. BOTH GFS AND ECMWF INDICATE A WEAK DISTURBANCE TRACKING
INTO WRN NM FROM THE WEST AROUND THURSDAY OF NEXT WEEK...NOT
CONFIDENT AT ALL IT WILL AMOUNT TO MUCH. IN ANY CASE WENT CLOSER TO
THE ECMWF SOLUTION FOR TEMPS AND WITH A GFS/ECMWF BLEND FOR POPS.
.FIRE WEATHER...
COOLER AIR WILL INVADE NEW MEXICO TODAY AS NORTHWEST FLOW ALOFT
DRAGS A TROUGH INTO THE STATE ALONG WITH A BACK DOOR SURFACE FRONT.
THE PLAINS WILL OBSERVE THE SHARPEST TEMPERATURE DIFFERENTIAL FROM
YESTERDAY ALONG WITH GUSTY NORTHEAST WINDS THROUGH THE DAY AS THE
FRONT SPILLS IN. THE CENTRAL TO WESTERN ZONES WILL ALSO BECOME
BREEZY TO WINDY WITH A NORTHWESTERLY DIRECTION. SURFACE GRADIENT
APPEARS A BIT STRONGER THAN PREVIOUS MODEL RUNS WERE
ADVERTISING...SO FORECAST SPEEDS WERE INCREASED TO REFLECT THIS.
VENTILATION RATES LOOK TO REMAIN GOOD TO EXCELLENT WITH THESE
STRONGER BOUNDARY LAYER BREEZES...BUT WINDS DO NOT APPEAR TO BE
CRITICALLY HIGH. DEWPOINTS DROP INTO THE LOWER TEENS AND SINGLE
DIGITS IN THE WEST CENTRAL TO SOUTHWESTERN ZONES OF THE FORECAST
AREA THIS AFTERNOON...DROPPING MINIMUM RH TO 12 TO 15 PERCENT. THIS
AREA OF CRITICALLY LOW RH WILL NOT BE JUXTAPOSED OVER THE AREA WHERE
THE STRONGEST WINDS WILL BE...AND THE COOLER TEMPERATURE REGIME DOES
NOT FIT INTO THE MOLD OF A CRITICAL FIRE WEATHER EVENT EITHER. MAX
TEMPERATURES WILL RUN ABOUT 8 TO 20 DEGREES BELOW NORMAL IN MOST
AREAS TODAY.
BETTER RH RECOVERY IS EXPECTED TONIGHT WITH COOLER TEMPERATURES.
DEWPOINTS MAY LOWER A BIT IN THE PLAINS BY TONIGHT...BUT THEY WILL
ACTUALLY RISE A BIT IN THE CENTRAL AREAS OF THE STATE. THIS WILL
ALLOW MOST OF THE NORTHERN AND EASTERN TIERS OF THE STATE TO OBSERVE
EXCELLENT RH RECOVERY WHILE CENTRAL TO WESTERN ZONES STAY IN THE
FAIR TO GOOD CATEGORIES. ANOTHER SIGNIFICANT ASPECT OF TONIGHT/S
FORECAST WILL BE THE POTENTIAL FOR FREEZING TEMPERATURES IN MUCH OF
THE EAST CENTRAL PLAINS WHERE THE FREEZING MARK HAS YET TO BE
REACHED. THIS WILL EXACERBATE FINE FUEL CURING. THERE WILL ALSO BE
POTENTIAL FOR FREEZING TEMPERATURES ALONG THE MIDDLE RIO GRANDE AND
TULAROSA VALLEYS...PRIMARILY IN THE LOWEST ELEVATIONS. SOME OF THESE
VALLEY AREAS HAVE FLIRTED WITH FREEZING ON A COUPLE OF OCCASIONS
THIS SEASON...BUT A WIDESPREAD HARD FREEZE HAS STILL NOT HAPPENED.
NORTHWEST FLOW WILL NOT BE AS STRONG ON SATURDAY...AND ONLY SOME
ISOLATED BREEZY TO WINDY CONDITIONS ARE EXPECTED OVER THE CENTRAL
HIGHLANDS. TEMPERATURES WILL WARM A FEW DEGREES IN MOST OF THE
FORECAST AREA AND SEVERAL DEGREES IN THE NORTHEASTERN PLAINS...BUT
STILL DAYTIME HIGHS IN ALL AREAS WILL FALL JUST SHY OF CLIMATOLOGY.
LOWEST DEWPOINTS WILL STAY CONFINED TO WEST CENTRAL NM
SATURDAY...BUT THESE WILL MIX AND ADVANCE EASTWARD INTO SUNDAY. THIS
WILL SPREAD SOME CRITICAL RH OVER THE CENTRAL HIGHLANDS WHERE A
BRIEF BOUT OF CRITICAL WINDS WILL ALSO DEVELOP SUNDAY AFTERNOON.
THE NEXT COLD FRONT WILL ARRIVE SUNDAY NIGHT AND INTO MONDAY
MORNING. THIS BOUNDARY WILL LIKELY ADVANCE BEYOND THE CENTRAL
MOUNTAIN CHAIN AND INTO THE RIO GRANDE VALLEY...PRODUCING SOME GUSTY
WINDS ALONG THE BOUNDARY AND THROUGH CENTRAL GAPS/CANYONS WHILE
TEMPERATURES PLUMMET BACK BELOW AVERAGE.
OVERALL A DRIER AND MORE TRANQUIL PATTERN IS EXPECTED THROUGH
TUESDAY AND WEDNESDAY OF NEXT WEEK...HOWEVER THERE IS SOME
UNCERTAINTY REGARDING ANOTHER POTENTIAL FRONT. FORECAST MODELS HAVE
DIFFERING NOTIONS ON HOW THE UPPER RIDGE WILL BREAK DOWN...AND
MODELS HISTORICALLY HAVE SOME NOTORIOUS DEFICIENCIES IN THESE HIGH
AMPLITUDE PATTERNS.
52
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR THE
FOLLOWING ZONES...NMZ519-520-525-533>538.
&&
$$
SHY
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
550 AM MDT FRI OCT 18 2013
.AVIATION...
12Z TAF CYCLE
SOME LOW STRATUS CLOUDS AND PATCHY FOG HAVE DEVELOPED AGAIN IN THE
EAST CENTRAL TO SOUTHEASTERN PLAINS OF NEW MEXICO EARLY THIS
MORNING. MVFR TO IFR CEILINGS AND VISIBILITIES SHOULD STAY EAST OF
A KROW TO KCVS LINE WHERE LOW LAYER MOISTURE HAS BEEN TRANSPORTED.
IN THE NORTHEAST CORNER OF THE STATE A BACK DOOR COLD FRONT IS
INVADING WITH GUSTY WINDS NOTED ALONG AND BEHIND THE BOUNDARY.
ALSO...SOME LOWER CEILINGS OF GENERALLY 2000 TO 3000 FEET ARE
ACCOMPANYING THE FRONT. THESE CLOUDS IN THE NORTHEAST MAY PERSIST
AND EXPAND OVER THE REMAINDER OF THE NORTHEASTERN QUADRANT OF NEW
MEXICO THROUGH THE MID AFTERNOON WHILE THE LOWER STRATUS CLOUDS
AND FOG IN EAST CENTRAL AND SOUTHEASTERN AREAS SHOULD DISSIPATE
BEFORE 18/1800UTC. VFR CONDITIONS WILL PREVAIL ELSEWHERE WITH
MOSTLY CLEAR SKIES.
52
&&
.PREV DISCUSSION...330 AM MDT FRI OCT 18 2013...
SFC LOW/TROUGH ACROSS FAR EAST CENTRAL NM AND INTO THE ADJACENT
PORTION OF TX HAS CIRCULATED LOW LEVEL MOISTURE INTO SE NM WITH
ATTENDANT LOW CLOUDS/FOG OVER LEA/EDDY AND SE ROOSEVELT
COUNTIES...WHICH IS FARTHER WEST THAN WAS INDICATED 24 HRS AGO.
EXPECT THIS WILL MAKE A LITTLE MORE PROGRESS NORTH AND WWD BEFORE
THE COLD FRONT...CURRENTLY FROM CAO TO RTN...AND WITH IT/S
STRATUS...PUSHES FARTHER SOUTH. RUC INDICATES THE MOISTURE IN THE
SOUTHEAST SHOULD EXIT BY MID MORNING WHILE THE STRATUS CONTINUES TO
INVADE THE NE AND TO SOME EXTENT THE EAST CENTRAL. TODAY/S AREAL
COVERAGE OF POPS DIDN/T CHANGE MUCH FROM PREVIOUS MODEL RUNS.
FORECAST HIGHS HOWEVER DID COOL SEVERAL DEGREES IN THE NORTHEAST AND
EAST CENTRAL NO DOUBT IN PART TO THE EXTENSIVE LOW CLOUDS THAT MAY
LINGER THROUGH EARLY/MID AFTERNOON ACCORDING TO THE RUC. THE AREA
FROM RATON TO CLAYTON MAY NOT GET ANY WARMER THAN MID 40S...WHICH IS
20 TO 25 DEGREES BELOW NORMAL IF THE GUIDANCE IS CLOSE. OVERALL
HIGHS TODAY RANGE FROM NEAR NORMAL FAR SOUTHWEST TO 10 TO 15 DEGREES
BELOW AVERAGE FAR NORTHWEST TO THE FAR SOUTHEAST.
THE COOLER THAN AVERAGE HIGHS SET THE STAGE FOR POTENTIAL FOR NEAR
TO BELOW FREEZING LOWS TONIGHT. GUIDANCE FOR PORTIONS OF THE EAST
CENTRAL CLOSER TO THE TX BORDER AND ROW AREAS HAS COOLED A COUPLE
MORE DEGREES...SO A FREEZE WATCH WILL BE ISSUED. SOME LOW LEVEL
MOISTURE MAY BE PARKED ALONG THE EAST SLOPES OF THE CENTRAL MT CHAIN
THIS EVENING BUT DEWPOINTS STILL EVENTUALLY LOWER SUFFICIENTLY FOR
THE THREAT OF A FREEZE.
MODELS NOW INDICATE AT LEAST SOME POTENTIAL FOR AN EAST WIND TO
BREAK INTO THE MIDDLE RGV THIS EVENING...WHICH COMPLICATES A
FREEZE/NO FREEZE DECISION THAT MUCH MORE ESPECIALLY IN THE ABQ
METRO. CURRENT THOUGHTS ARE THE WIND COULD DIMINISH AFTER
MIDNIGHT...SO DECIDED TO ISSUE A FREEZE WATCH FOR THE MIDDLE AND
LOWER RGV AS WELL AS FOR THE UPPER TULAROSA VALLEY...WHERE SOME
LOCALES HAVE NOT YET FROZEN.
FOR THE REST OF THE WEEKEND...A WARMING TREND WILL COMMENCE WITH
HIGHS ACHIEVING NEAR NORMAL STATUS SUNDAY. ANOTHER FRONT COULD
ARRIVE IN THE EASTERN PLAINS AS SOON AS LATE SUNDAY...SO HIGHS WILL
BE KNOCKED DOWNWARD MONDAY. THIS FRONT LOOKS MORE LIKELY TO PRODUCE
AN EAST WIND INTO THE RGV EARLY MONDAY.
EXTENDED FORECAST MODEL TRENDS FOR MID TO LATE NEXT WEEK LEAN
TOWARDS MORE OF A RIDGE OVER NEW MEXICO. LATEST ECMWF DEPICTS A
DECENT SFC HIGH INVADING ERN NM DESPITE THE RIDGE WHILE THE GFS
LOCATES IT WELL TO THE EAST...WREAKING HAVOC ON FORECAST TEMPERATURE
DECISIONS. BOTH GFS AND ECMWF INDICATE A WEAK DISTURBANCE TRACKING
INTO WRN NM FROM THE WEST AROUND THURSDAY OF NEXT WEEK...NOT
CONFIDENT AT ALL IT WILL AMOUNT TO MUCH. IN ANY CASE WENT CLOSER TO
THE ECMWF SOLUTION FOR TEMPS AND WITH A GFS/ECMWF BLEND FOR POPS.
.FIRE WEATHER...
COOLER AIR WILL INVADE NEW MEXICO TODAY AS NORTHWEST FLOW ALOFT
DRAGS A TROUGH INTO THE STATE ALONG WITH A BACK DOOR SURFACE FRONT.
THE PLAINS WILL OBSERVE THE SHARPEST TEMPERATURE DIFFERENTIAL FROM
YESTERDAY ALONG WITH GUSTY NORTHEAST WINDS THROUGH THE DAY AS THE
FRONT SPILLS IN. THE CENTRAL TO WESTERN ZONES WILL ALSO BECOME
BREEZY TO WINDY WITH A NORTHWESTERLY DIRECTION. SURFACE GRADIENT
APPEARS A BIT STRONGER THAN PREVIOUS MODEL RUNS WERE
ADVERTISING...SO FORECAST SPEEDS WERE INCREASED TO REFLECT THIS.
VENTILATION RATES LOOK TO REMAIN GOOD TO EXCELLENT WITH THESE
STRONGER BOUNDARY LAYER BREEZES...BUT WINDS DO NOT APPEAR TO BE
CRITICALLY HIGH. DEWPOINTS DROP INTO THE LOWER TEENS AND SINGLE
DIGITS IN THE WEST CENTRAL TO SOUTHWESTERN ZONES OF THE FORECAST
AREA THIS AFTERNOON...DROPPING MINIMUM RH TO 12 TO 15 PERCENT. THIS
AREA OF CRITICALLY LOW RH WILL NOT BE JUXTAPOSED OVER THE AREA WHERE
THE STRONGEST WINDS WILL BE...AND THE COOLER TEMPERATURE REGIME DOES
NOT FIT INTO THE MOLD OF A CRITICAL FIRE WEATHER EVENT EITHER. MAX
TEMPERATURES WILL RUN ABOUT 8 TO 20 DEGREES BELOW NORMAL IN MOST
AREAS TODAY.
BETTER RH RECOVERY IS EXPECTED TONIGHT WITH COOLER TEMPERATURES.
DEWPOINTS MAY LOWER A BIT IN THE PLAINS BY TONIGHT...BUT THEY WILL
ACTUALLY RISE A BIT IN THE CENTRAL AREAS OF THE STATE. THIS WILL
ALLOW MOST OF THE NORTHERN AND EASTERN TIERS OF THE STATE TO OBSERVE
EXCELLENT RH RECOVERY WHILE CENTRAL TO WESTERN ZONES STAY IN THE
FAIR TO GOOD CATEGORIES. ANOTHER SIGNIFICANT ASPECT OF TONIGHT/S
FORECAST WILL BE THE POTENTIAL FOR FREEZING TEMPERATURES IN MUCH OF
THE EAST CENTRAL PLAINS WHERE THE FREEZING MARK HAS YET TO BE
REACHED. THIS WILL EXACERBATE FINE FUEL CURING. THERE WILL ALSO BE
POTENTIAL FOR FREEZING TEMPERATURES ALONG THE MIDDLE RIO GRANDE AND
TULAROSA VALLEYS...PRIMARILY IN THE LOWEST ELEVATIONS. SOME OF THESE
VALLEY AREAS HAVE FLIRTED WITH FREEZING ON A COUPLE OF OCCASIONS
THIS SEASON...BUT A WIDESPREAD HARD FREEZE HAS STILL NOT HAPPENED.
NORTHWEST FLOW WILL NOT BE AS STRONG ON SATURDAY...AND ONLY SOME
ISOLATED BREEZY TO WINDY CONDITIONS ARE EXPECTED OVER THE CENTRAL
HIGHLANDS. TEMPERATURES WILL WARM A FEW DEGREES IN MOST OF THE
FORECAST AREA AND SEVERAL DEGREES IN THE NORTHEASTERN PLAINS...BUT
STILL DAYTIME HIGHS IN ALL AREAS WILL FALL JUST SHY OF CLIMATOLOGY.
LOWEST DEWPOINTS WILL STAY CONFINED TO WEST CENTRAL NM
SATURDAY...BUT THESE WILL MIX AND ADVANCE EASTWARD INTO SUNDAY. THIS
WILL SPREAD SOME CRITICAL RH OVER THE CENTRAL HIGHLANDS WHERE A
BRIEF BOUT OF CRITICAL WINDS WILL ALSO DEVELOP SUNDAY AFTERNOON.
THE NEXT COLD FRONT WILL ARRIVE SUNDAY NIGHT AND INTO MONDAY
MORNING. THIS BOUNDARY WILL LIKELY ADVANCE BEYOND THE CENTRAL
MOUNTAIN CHAIN AND INTO THE RIO GRANDE VALLEY...PRODUCING SOME GUSTY
WINDS ALONG THE BOUNDARY AND THROUGH CENTRAL GAPS/CANYONS WHILE
TEMPERATURES PLUMMET BACK BELOW AVERAGE.
OVERALL A DRIER AND MORE TRANQUIL PATTERN IS EXPECTED THROUGH
TUESDAY AND WEDNESDAY OF NEXT WEEK...HOWEVER THERE IS SOME
UNCERTAINTY REGARDING ANOTHER POTENTIAL FRONT. FORECAST MODELS HAVE
DIFFERING NOTIONS ON HOW THE UPPER RIDGE WILL BREAK DOWN...AND
MODELS HISTORICALLY HAVE SOME NOTORIOUS DEFICIENCIES IN THESE HIGH
AMPLITUDE PATTERNS.
52
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR THE
FOLLOWING ZONES...NMZ519-520-525-533>538.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
330 AM MDT FRI OCT 18 2013
.DISCUSSION...
SFC LOW/TROUGH ACROSS FAR EAST CENTRAL NM AND INTO THE ADJACENT
PORTION OF TX HAS CIRCULATED LOW LEVEL MOISTURE INTO SE NM WITH
ATTENDANT LOW CLOUDS/FOG OVER LEA/EDDY AND SE ROOSEVELT
COUNTIES...WHICH IS FARTHER WEST THAN WAS INDICATED 24 HRS AGO.
EXPECT THIS WILL MAKE A LITTLE MORE PROGRESS NORTH AND WWD BEFORE
THE COLD FRONT...CURRENTLY FROM CAO TO RTN...AND WITH IT/S
STRATUS...PUSHES FARTHER SOUTH. RUC INDICATES THE MOISTURE IN THE
SOUTHEAST SHOULD EXIT BY MID MORNING WHILE THE STRATUS CONTINUES TO
INVADE THE NE AND TO SOME EXTENT THE EAST CENTRAL. TODAY/S AREAL
COVERAGE OF POPS DIDN/T CHANGE MUCH FROM PREVIOUS MODEL RUNS.
FORECAST HIGHS HOWEVER DID COOL SEVERAL DEGREES IN THE NORTHEAST AND
EAST CENTRAL NO DOUBT IN PART TO THE EXTENSIVE LOW CLOUDS THAT MAY
LINGER THROUGH EARLY/MID AFTERNOON ACCORDING TO THE RUC. THE AREA
FROM RATON TO CLAYTON MAY NOT GET ANY WARMER THAN MID 40S...WHICH IS
20 TO 25 DEGREES BELOW NORMAL IF THE GUIDANCE IS CLOSE. OVERALL
HIGHS TODAY RANGE FROM NEAR NORMAL FAR SOUTHWEST TO 10 TO 15 DEGREES
BELOW AVERAGE FAR NORTHWEST TO THE FAR SOUTHEAST.
THE COOLER THAN AVERAGE HIGHS SET THE STAGE FOR POTENTIAL FOR NEAR
TO BELOW FREEZING LOWS TONIGHT. GUIDANCE FOR PORTIONS OF THE EAST
CENTRAL CLOSER TO THE TX BORDER AND ROW AREAS HAS COOLED A COUPLE
MORE DEGREES...SO A FREEZE WATCH WILL BE ISSUED. SOME LOW LEVEL
MOISTURE MAY BE PARKED ALONG THE EAST SLOPES OF THE CENTRAL MT CHAIN
THIS EVENING BUT DEWPOINTS STILL EVENTUALLY LOWER SUFFICIENTLY FOR
THE THREAT OF A FREEZE.
MODELS NOW INDICATE AT LEAST SOME POTENTIAL FOR AN EAST WIND TO
BREAK INTO THE MIDDLE RGV THIS EVENING...WHICH COMPLICATES A
FREEZE/NO FREEZE DECISION THAT MUCH MORE ESPECIALLY IN THE ABQ
METRO. CURRENT THOUGHTS ARE THE WIND COULD DIMINISH AFTER
MIDNIGHT...SO DECIDED TO ISSUE A FREEZE WATCH FOR THE MIDDLE AND
LOWER RGV AS WELL AS FOR THE UPPER TULAROSA VALLEY...WHERE SOME
LOCALES HAVE NOT YET FROZEN.
FOR THE REST OF THE WEEKEND...A WARMING TREND WILL COMMENCE WITH
HIGHS ACHIEVING NEAR NORMAL STATUS SUNDAY. ANOTHER FRONT COULD
ARRIVE IN THE EASTERN PLAINS AS SOON AS LATE SUNDAY...SO HIGHS WILL
BE KNOCKED DOWNWARD MONDAY. THIS FRONT LOOKS MORE LIKELY TO PRODUCE
AN EAST WIND INTO THE RGV EARLY MONDAY.
EXTENDED FORECAST MODEL TRENDS FOR MID TO LATE NEXT WEEK LEAN
TOWARDS MORE OF A RIDGE OVER NEW MEXICO. LATEST ECMWF DEPICTS A
DECENT SFC HIGH INVADING ERN NM DESPITE THE RIDGE WHILE THE GFS
LOCATES IT WELL TO THE EAST...WREAKING HAVOC ON FORECAST TEMPERATURE
DECISIONS. BOTH GFS AND ECMWF INDICATE A WEAK DISTURBANCE TRACKING
INTO WRN NM FROM THE WEST AROUND THURSDAY OF NEXT WEEK...NOT
CONFIDENT AT ALL IT WILL AMOUNT TO MUCH. IN ANY CASE WENT CLOSER TO
THE ECMWF SOLUTION FOR TEMPS AND WITH A GFS/ECMWF BLEND FOR POPS.
&&
.FIRE WEATHER...
COOLER AIR WILL INVADE NEW MEXICO TODAY AS NORTHWEST FLOW ALOFT
DRAGS A TROUGH INTO THE STATE ALONG WITH A BACK DOOR SURFACE FRONT.
THE PLAINS WILL OBSERVE THE SHARPEST TEMPERATURE DIFFERENTIAL FROM
YESTERDAY ALONG WITH GUSTY NORTHEAST WINDS THROUGH THE DAY AS THE
FRONT SPILLS IN. THE CENTRAL TO WESTERN ZONES WILL ALSO BECOME
BREEZY TO WINDY WITH A NORTHWESTERLY DIRECTION. SURFACE GRADIENT
APPEARS A BIT STRONGER THAN PREVIOUS MODEL RUNS WERE
ADVERTISING...SO FORECAST SPEEDS WERE INCREASED TO REFLECT THIS.
VENTILATION RATES LOOK TO REMAIN GOOD TO EXCELLENT WITH THESE
STRONGER BOUNDARY LAYER BREEZES...BUT WINDS DO NOT APPEAR TO BE
CRITICALLY HIGH. DEWPOINTS DROP INTO THE LOWER TEENS AND SINGLE
DIGITS IN THE WEST CENTRAL TO SOUTHWESTERN ZONES OF THE FORECAST
AREA THIS AFTERNOON...DROPPING MINIMUM RH TO 12 TO 15 PERCENT. THIS
AREA OF CRITICALLY LOW RH WILL NOT BE JUXTAPOSED OVER THE AREA WHERE
THE STRONGEST WINDS WILL BE...AND THE COOLER TEMPERATURE REGIME DOES
NOT FIT INTO THE MOLD OF A CRITICAL FIRE WEATHER EVENT EITHER. MAX
TEMPERATURES WILL RUN ABOUT 8 TO 20 DEGREES BELOW NORMAL IN MOST
AREAS TODAY.
BETTER RH RECOVERY IS EXPECTED TONIGHT WITH COOLER TEMPERATURES.
DEWPOINTS MAY LOWER A BIT IN THE PLAINS BY TONIGHT...BUT THEY WILL
ACTUALLY RISE A BIT IN THE CENTRAL AREAS OF THE STATE. THIS WILL
ALLOW MOST OF THE NORTHERN AND EASTERN TIERS OF THE STATE TO OBSERVE
EXCELLENT RH RECOVERY WHILE CENTRAL TO WESTERN ZONES STAY IN THE
FAIR TO GOOD CATEGORIES. ANOTHER SIGNIFICANT ASPECT OF TONIGHT/S
FORECAST WILL BE THE POTENTIAL FOR FREEZING TEMPERATURES IN MUCH OF
THE EAST CENTRAL PLAINS WHERE THE FREEZING MARK HAS YET TO BE
REACHED. THIS WILL EXACERBATE FINE FUEL CURING. THERE WILL ALSO BE
POTENTIAL FOR FREEZING TEMPERATURES ALONG THE MIDDLE RIO GRANDE AND
TULAROSA VALLEYS...PRIMARILY IN THE LOWEST ELEVATIONS. SOME OF THESE
VALLEY AREAS HAVE FLIRTED WITH FREEZING ON A COUPLE OF OCCASIONS
THIS SEASON...BUT A WIDESPREAD HARD FREEZE HAS STILL NOT HAPPENED.
NORTHWEST FLOW WILL NOT BE AS STRONG ON SATURDAY...AND ONLY SOME
ISOLATED BREEZY TO WINDY CONDITIONS ARE EXPECTED OVER THE CENTRAL
HIGHLANDS. TEMPERATURES WILL WARM A FEW DEGREES IN MOST OF THE
FORECAST AREA AND SEVERAL DEGREES IN THE NORTHEASTERN PLAINS...BUT
STILL DAYTIME HIGHS IN ALL AREAS WILL FALL JUST SHY OF CLIMATOLOGY.
LOWEST DEWPOINTS WILL STAY CONFINED TO WEST CENTRAL NM
SATURDAY...BUT THESE WILL MIX AND ADVANCE EASTWARD INTO SUNDAY. THIS
WILL SPREAD SOME CRITICAL RH OVER THE CENTRAL HIGHLANDS WHERE A
BRIEF BOUT OF CRITICAL WINDS WILL ALSO DEVELOP SUNDAY AFTERNOON.
THE NEXT COLD FRONT WILL ARRIVE SUNDAY NIGHT AND INTO MONDAY
MORNING. THIS BOUNDARY WILL LIKELY ADVANCE BEYOND THE CENTRAL
MOUNTAIN CHAIN AND INTO THE RIO GRANDE VALLEY...PRODUCING SOME GUSTY
WINDS ALONG THE BOUNDARY AND THROUGH CENTRAL GAPS/CANYONS WHILE
TEMPERATURES PLUMMET BACK BELOW AVERAGE.
OVERALL A DRIER AND MORE TRANQUIL PATTERN IS EXPECTED THROUGH
TUESDAY AND WEDNESDAY OF NEXT WEEK...HOWEVER THERE IS SOME
UNCERTAINTY REGARDING ANOTHER POTENTIAL FRONT. FORECAST MODELS HAVE
DIFFERING NOTIONS ON HOW THE UPPER RIDGE WILL BREAK DOWN...AND
MODELS HISTORICALLY HAVE SOME NOTORIOUS DEFICIENCIES IN THESE HIGH
AMPLITUDE PATTERNS.
52
&&
.AVIATION...
06Z TAF CYCLE
VFR CONDITIONS SHOULD PREVAIL THROUGH THE NEXT 24 HOURS AT ALL
TAF SITES. BACK DOOR COLD FRONT IN FAR NE NOW WILL DROP SOUTH
AND WEST OVERNIGHT INTO FRIDAY. HAVE A WIND SHIFT IN KTCC AT 12Z
FRIDAY AND KROW AT 15Z FRIDAY. LOW CLOUDS...BKN030...ALREADY
FORMING AROUND CAO AND COULD IMPACT TCC LATER TONIGHT. NOT ENOUGH
CONFIDENCE TO PUT IN THE TAF THOUGH. GOOD CHANCE SE WIND AT SAF
SAF FROM 01Z TO 06Z FRIDAY EVENING AND BRIEF E WIND POSSIBLE IN
ABQ BETWEEN 02Z AND 06Z...PUT IN TEMPO GROUP FOR ABQ.
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 58 26 61 30 / 0 0 0 0
DULCE........................... 55 21 59 24 / 0 0 0 0
CUBA............................ 55 24 58 27 / 0 0 0 0
GALLUP.......................... 58 17 62 22 / 0 0 0 0
EL MORRO........................ 56 18 60 24 / 0 0 0 0
GRANTS.......................... 59 20 62 26 / 0 0 0 0
QUEMADO......................... 60 23 65 29 / 0 0 0 0
GLENWOOD........................ 70 30 71 35 / 0 0 0 0
CHAMA........................... 49 18 54 19 / 0 0 5 5
LOS ALAMOS...................... 55 26 59 29 / 0 0 0 0
PECOS........................... 53 26 59 29 / 5 5 5 0
CERRO/QUESTA.................... 50 17 56 19 / 5 5 5 5
RED RIVER....................... 43 17 48 23 / 10 5 5 5
ANGEL FIRE...................... 47 18 55 20 / 10 5 5 5
TAOS............................ 52 18 58 22 / 5 5 0 0
MORA............................ 50 21 59 26 / 5 5 5 5
ESPANOLA........................ 59 24 62 28 / 0 0 0 0
SANTA FE........................ 56 25 59 29 / 0 0 0 0
SANTA FE AIRPORT................ 58 27 61 32 / 0 0 0 0
ALBUQUERQUE FOOTHILLS........... 59 31 59 36 / 0 0 0 0
ALBUQUERQUE HEIGHTS............. 62 35 62 40 / 0 0 0 0
ALBUQUERQUE VALLEY.............. 64 29 63 37 / 0 0 0 0
ALBUQUERQUE WEST MESA........... 63 33 63 38 / 0 0 0 0
LOS LUNAS....................... 66 34 66 39 / 0 0 0 0
RIO RANCHO...................... 62 34 62 40 / 0 0 0 0
SOCORRO......................... 68 37 67 41 / 0 0 0 0
SANDIA PARK/CEDAR CREST......... 60 28 57 34 / 0 0 5 0
TIJERAS......................... 61 29 59 34 / 0 0 0 0
MORIARTY/ESTANCIA............... 59 27 61 31 / 0 0 5 0
CLINES CORNERS.................. 56 29 59 34 / 5 5 5 0
GRAN QUIVIRA.................... 61 29 62 34 / 0 5 5 0
CARRIZOZO....................... 66 32 64 36 / 0 0 0 0
RUIDOSO......................... 60 36 59 41 / 0 5 5 0
CAPULIN......................... 43 19 59 26 / 20 5 5 5
RATON........................... 46 21 62 28 / 20 5 5 5
SPRINGER........................ 50 22 62 30 / 10 5 5 5
LAS VEGAS....................... 51 23 62 32 / 5 5 5 5
CLAYTON......................... 44 30 65 36 / 20 5 5 5
ROY............................. 50 28 62 36 / 5 5 5 5
CONCHAS......................... 55 30 66 34 / 5 5 5 5
SANTA ROSA...................... 56 30 69 36 / 0 5 5 5
TUCUMCARI....................... 54 30 69 37 / 5 5 5 5
CLOVIS.......................... 55 30 64 37 / 5 5 5 5
PORTALES........................ 58 31 65 38 / 5 5 5 5
FORT SUMNER..................... 61 32 67 38 / 0 5 5 5
ROSWELL......................... 73 36 68 43 / 0 5 5 0
PICACHO......................... 69 33 67 39 / 0 5 5 0
ELK............................. 66 33 65 38 / 0 5 5 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR THE
FOLLOWING ZONES...NMZ519-520-525-533>538.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
743 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A LINGERING COLD FRONT OVER THE COASTAL CAROLINAS WILL MOVE OFF
SHORE AS HIGH PRESSURE BUILDS IN THROUGH SUNDAY. THE FRONT WILL
SHIFT BACK TOWARD THE COAST AS HIGH PRESSURE MOVES OFF TO THE
NORTHEAST LATE MONDAY INTO TUESDAY. COLDER HIGH PRESSURE WILL
SLOWLY BUILD INTO THE AREA MID THROUGH LATE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 6 PM SATURDAY...THE LATEST RADAR TRENDS SUGGEST FAVORABLE
DYNAMICS ALOFT ARE BEGINNING TO PLAY A ROLE IN THE UPTREND IN
SHOWER ACTIVITY PRESENTLY. AN UPPER JET CROSSING THE APPALACHIANS
IS PRODUCING A ZONE OF DIFFLUENCE ALOFT OVER CENTRAL CAROLINAS
WHICH IS GRADUALLY EDGING EASTWARD. INITIALLY HIGHER POP VALUES
THIS EVENING ARE PLACED ACROSS OUR WESTERN ZONES...SPREADING OVER
MUCH OF THE FORECAST AREA OVERNIGHT. INSTABILITY OVER THE REGION
REMAINS WEAK AND PRECIPITABLE WATERS HIGH...SO WILL MAINTAIN A
MENTION OF ISOLATED SHOWERS THROUGH 12Z SUNDAY. THE LATEST NAM
MODEL RUN DEPICTS EXPANDING STRATIFORM RAIN OVER THE EASTERN
CAROLINAS AFTER 6Z/2AM TONIGHT INTO DAYBREAK SUNDAY...AS MOISTURE
ALOFT FROM THE SW OVER-RUNS THE LEADING EDGE OF BUILDING HIGH
PRESSURE AND NORTHERLY WIND FLOW IN THE LOW-LEVELS. THIS IS
FEASIBLE AND THE ISENTROPIC OMEGA WOULD HELP SATURATE THE LOW AND
MID LEVELS. WITH THIS IN MIND WE MAY NEED TO BRING POP VALUES UP
WITH THE MID EVENING UPDATE FOR THE DAYBREAK SUNDAY TIME FRAME.
WILL ALSO NEED TO TAKE A CLOSER LOOK AT MINIMUMS FOR DAYBREAK
SUNDAY AS THE RUC UPDATES SUGGEST OVERNIGHT WILL REMAIN MILDER
THAN FORECAST WITH CLOUDS AND POTENTIAL STRATIFORM RAIN IN THE
PRE-DAWN HOURS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...COLD FRONT WILL SHIFT SLIGHTLY FURTHER
SOUTH AND EAST OFF THE COAST THROUGH SUNDAY AS HIGH PRESSURE
BUILDS IN BEHIND IT. THIS WILL ALLOW AREA TO DRY OUT THROUGH
SUNDAY. LOOKS LIKE DRYING OUT MAY BE SLOWER THAN PREVIOUS THOUGHT
WITH INCREASING SUNSHINE THROUGH THE LATE MORNING INTO EARLY
AFTERNOON FROM WEST TO EAST ACROSS FORECAST AREA. STILL A
DISCREPANCY OF 5 TO 10 DEGREES BETWEEN NAM AND MAV GUIDANCE FOR
DEWPOINT TEMPS SUNDAY AFTERNOON WITH THE NAM BEING DRIER. EITHER
WAY...SUNDAY LOOKS TO BE SHAPING UP TO BE A NICE FALL-LIKE DAY
WITH A GOOD DEAL OF AFTERNOON SUNSHINE.
THE HIGH PRESSURE WILL SLIP OFF THE DELMARVA COAST BY MONDAY
MORNING ALLOWING THIS LINGERING FRONT TO SHIFT BACK TOWARD THE
COAST PLAGUING THE AREA WITH CLOUDS AND PCP ONCE AGAIN. COASTAL
SECTIONS MAY BE INTO THE CLOUDS BY DAYBREAK BUT THE CLOUDS AND PCP
WILL SPREAD BACK TOWARD THE NORTH. PERTURBATIONS IN THE SOUTHWEST
FLOW ALOFT WILL AID IN GENERATING CLOUDS AND A WAVE OF LOW
PRESSURE AT THE SURFACE WILL ALSO MOVE ALONG THE BOUNDARY FROM
SOUTHWEST TO NORTHEAST INCREASING PCP CHANCES BY LATE MONDAY NIGHT.
EXPECT MORE IN THE WAY OF CLOUDS THROUGH MONDAY WITH LIGHT PCP
MAINLY OFF SHORE AND CLOSE TO THE COAST BY LATE DAY AND BETTER CHC
OF MEASURABLE PCP OVERNIGHT MONDAY.
COOL AND DRY AIR ADVECTION THROUGH SUNDAY WILL KEEP DAY TIME HIGHS
CLOSER TO 70 AND OVERNIGHT LOWS WILL DROP OUT IN MORE IDEAL
RADIATIONAL COOLING CONDITIONS. CLOUDS TOWARD DAYBREAK COULD
HAMPER TEMP FALLS BUT FOR NOW WILL KEEP WITH READINGS BETWEEN 45
AND 50 MOST PLACES. CLOUDS WILL KEEP TMPS SLIGHTLY COOLER ON
MONDAY ONCE AGAIN AND WARMER OVERNIGHT WITH READINGS IN THE MID
TO UPPER 50S BY MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...UNSETTLED WEATHER TO BEGIN THE PERIOD...BUT
THE STORY OF THE EXTENDED WILL FOCUS PRIMARILY ON THE COLD OUTBREAK
EXPECTED FOR THE END OF THE WEEK.
BROAD MID-LEVEL TROUGHING BEGINS TO SHARPEN AT THE START OF THE
PERIOD...BUT THE TROUGH AXIS REMAINS WEST OF THE LOCAL AREA ON
TUESDAY. THIS DRIVES MOIST SW FLOW THROUGH MUCH OF THE
COLUMN...WHICH IS TAPPED BY WEAK WAVES OF LOW PRESSURE WHICH WILL
MOVE ALONG A STALLED BOUNDARY JUST OFF THE SE COAST. THESE WILL WORK
TOGETHER TO CREATE DECENT PRECIP CHANCES TUESDAY. ONLY LIGHT RAIN IS
EXPECTED WITH .1 TO .25 QPF LIKELY...HIGHEST ALONG THE
COAST...BEFORE DRYING BEGINS LATE TUESDAY NIGHT AS SOME NVA DEVELOPS
ALOFT AND SURFACE FLOW VEERS TO THE W/NW.
THE REST OF THE PERIOD WILL BE DRY...BUT THE COOLEST AIR OF THE
SEASON IS EXPECTED TO FLOOD INTO THE CAROLINAS BEGINNING THURSDAY.
WEDNESDAY WILL BE A TRANSITIONAL DAY WITH DRYING OCCURRING...BUT CAA
DELAYED UNTIL LATE AS THE UPPER TROUGH AXIS MOVES EAST OF THE AREA.
WHILE THIS HAPPENS...STRONG CYCLOGENESIS OCCURS OFF THE NEW ENGLAND
COAST...WHICH DRIVES THE SECONDARY COLD FRONT OVER THE AREA AND
HELPS STRONG CAA DEVELOP IN ADVANCE OF A CANADIAN HIGH SINKING SOUTH
ACROSS THE CENTRAL PLAINS. THIS HIGH WILL THEN SLOWLY MIGRATE
EAST...BECOMING OVERHEAD THE CAROLINAS SATURDAY.
WHILE TUESDAY WILL BE UNSETTLED WITH TEMPS AROUND CLIMO...AND
WEDNESDAY WILL BE SIMILAR BUT DRY...MUCH COOLER AIR EXPECTED
THU-SAT. GUIDANCE DISAGREES ON JUST HOW COLD IT WILL GET HERE...BUT
ATTM SUPPORT THE COOLER GFS DUE TO STRONG CAA BEHIND THE LOW
PRESSURE OFF THE NE COAST. THIS DRAGS 850MB TEMPS BELOW
0C...SUPPORTING HIGHS IN THE MID 60S AND LOWS IN THE 40S. AS THE
HIGH MOVES OVERHEAD FRI INTO SAT...GRADIENT WILL RELAX...AND
SATURDAY MAY END UP BEING THE COLDEST OF THE PERIOD...WITH SATURDAY
MORNING LOWS IN SOME PLACES DROPPING INTO THE 30S.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...EXPECT VFR THROUGH THE VALID TAF PERIOD...THOUGH A BRIEF
PERIOD OF MVFR DUE TO LINGERING LOW CIG OVERNIGHT.
CONDITIONS ARE FAIRLY QUIET ACROSS THE AREA THIS EVENING AS LIGHT
SHOWERS...NEARLY CALM WINDS...AND MID TO HIGH LEVEL CLOUDS PUSH
ACROSS THE AREA AHEAD OF AN APPROACHING COLD FRONT. ANTICIPATE THE
WEAK SYSTEM TO PUSH THROUGH THE INLAND SITES AROUND 06Z...REACHING
THE COAST AROUND 09Z. COULD NOT RULE OUT SOME LOWERED CIGS AND LIGHT
RAIN ALONG THE COAST IN THE EARLY MORNING HOURS. ONCE THE FRONT
PUSHES THROUGH...VFR WILL PREVAIL AS CLOUDS WILL GRADUALLY SCATTER
OUT FROM WEST TO EAST. WINDS WILL SHIFT BECOMING
NORTH-NORTHWESTERLY...WITH GUSTY WINDS UP TO NEAR 18 KTS AS COLD AIR
ADVECTION MOVES INTO THE AREA. INTO THE EVENING HOURS...GUSTS WILL
SUBSIDE AND WINDS WILL BECOME NORTH-NORTHEAST AOB 11 KTS.
EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED. LIGHT RAIN DEVELOPING
TUESDAY MORNING INTO WEDNESDAY IN ASSOCIATION WITH AN APPROACHING
FRONTAL SYSTEM.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 PM SATURDAY...HIGH PRESSURE APPROACHING FROM THE WEST WILL
BRING A WIND-SHIFT TO NORTH TO THE COASTAL WATERS AROUND 2AM OVER
THE NC WATERS AND BY 5AM SOUTH CAROLINA WATERS. THIS SURGE OF
NORTH WIND WILL BRING INCREASING WIND SPEEDS OF 15 KT AND GUSTY
INTO EARLY SUNDAY...ALTHOUGH THE MAINLY NORTH TRAJECTORY/OFFSHORE
WILL KEEP SEAS RELATIVELY SMALL INSHORE...WITH LARGEST SEAS OUTER
PORTION. THE MODERATE NORTH CHOP WILL INTERACT WITH 2 FT OF ESE
WAVES IN 8-9 SECOND INTERVALS. SHOWERS AND ISOLATED TSTMS WILL BE
POSSIBLE OVERNIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY
NIGHT/... AS OF 3 PM SATURDAY...FRONT WILL BE SHIFTING SOUTH AND
EAST AND SHOULD CLEAR LOCAL WATERS BY SUNDAY MORNING. HIGH
PRESSURE WILL BUILD IN BEHIND IT WITH NORTHERLY WINDS AROUND 10 TO
15 KTS. WINDS WILL VEER AROUND TO THE NORTHEAST SUNDAY NIGHT INTO
MONDAY AS HIGH PRESSURE MOVES OFF THE DELMARVA COAST. MAY SEE
SLIGHT SPIKE IN WINDS AND SEAS SUNDAY NIGHT IN COOL AND DRY
ADVECTION. WINDS WILL WEAKEN THROUGH MONDAY INTO MONDAY NIGHT AS
FRONT SHIFTS BACK NORTHWEST TOWARD THE CAPE FEAR COAST. OVERALL
LIGHT WIND FLOW WILL MAINTAIN SEAS 2 TO 3 FT BUT MAY SEE A FEW 4
FTERS IN OUTER WATERS SUNDAY NIGHT.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...STALLED BOUNDARY ACROSS THE WATERS WILL KEEP
WINDS LIGHT AND GENERALLY OUT OF THE NORTH TUE. PASSAGE OF WEAK
SURFACE WAVE DURING THE DAY TUE MAY RESULT IN WINDS BECOMING MORE
VARIABLE BUT LITTLE CHANGE TO GRADIENT...AND THUS WIND SPEED...IS
EXPECTED. NORTHWEST FLOW DEVELOPS IN ERNEST WED WITH WINDS
BECOMING 10 TO 15 KT. WINDS COULD BECOME GUSTY WED NIGHT AS FIRST
ROUND OF COLD ADVECTION BEGINS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION...COR
NWS WILMINGTON NC
335 PM EDT FRI OCT 18 2013
.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL LIFT NORTHEAST ALONG A STALLED COLD
FRONT OVER THE COASTAL CAROLINAS TONIGHT INTO EARLY SATURDAY. HIGH
PRESSURE WILL FORCE THE FRONT TO OUR SOUTH SUNDAY AND MONDAY. THE
FRONT MAY RETURN NORTHWARD AS HIGH PRESSURE MOVES OFFSHORE MONDAY
NIGHT INTO TUESDAY. A LARGE AREA OF COOL HIGH PRESSURE WILL SLOWLY
BUILD INTO THE AREA LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...A SLOW EVOLUTION OF SHOWERS HAS MATERIALIZED
SO FAR ACROSS THE REGION...REMAINING ISOLATED THIS AFTERNOON AND
TRACKING PRIMARILY ACROSS OUR CENTRAL ZONES FROM SW TO NE. RAIN
PROBABILITIES AND QPF BOTH WILL TAKE A TURN UPWARD TONIGHT AS A
WAVE OF LOW PRESSURE TRACKS NE ALONG OUR COAST LATE TONIGHT INTO
EARLY SATURDAY. THIS DEVELOPING AREA OF LOW PRESSURE HAS EMERGED
AND CURRENTLY IS POSITIONED ALONG THE SE GEORGIA COAST.
A RIBBON OF ENHANCED PRECIPITABLE WATERS REMAINED STRETCHED ALONG
THE GA/SC COAST...TROPICAL MOISTURE REMNANTS OF FORMER PACIFIC
SYSTEM OCTAVE. FORCING AND INSTABILITY HAS REMAINED FEEBLE ACROSS
THE AREA AND THIS WILL CONTINUE INTO EVENING. CONVERGENCE HOWEVER
WILL BE ON THE UPSWING LATE TONIGHT THROUGH DAYBREAK SATURDAY AS
THE LOW PRESSURE WAVE NEARS AND TRACKS UP OUR COAST. THIS SHOULD
TAP INTO A RICH MOISTURE SOURCE TO PRODUCE MORE WIDESPREAD AND
HEAVIER SHOWERS. SINCE THE WAVE WILL TRACK NEAR AND ALONG THE
COAST LATE TONIGHT...THIS IS WHERE WE HAVE FAVORED THE HIGHER POP
VALUES. A MYRIAD OF QPF SOLUTIONS ARE OFFERED BUT BY CONSENSUS AND
WPC DEPICTIONS 0.25-0.50" INCHES OF RAIN REMAINS A GOOD BET ALONG
OUR COASTAL ZONES THROUGH DAYBREAK SATURDAY...WITH LESS AMOUNTS
AND MORE STRATIFORM TYPE -RA FARTHER INLAND AWAY FROM THE PASSING
WAVE. MINIMUMS SHOULD HOLD IN THE LOW TO MIDDLE 60S NEAR THE COAST
IN BETTER MIXING...WHILE DEEP INLAND AN INVERSION AND LOW-LEVEL
COOLING WILL BRING TEMPERATURES INTO THE UPPER 50S BY DAYBREAK
SATURDAY.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...WE WILL SEE A COMPLETE TRANSITION TO A DRIER
AND MORE FALL LIKE AIR MASS BY THE LATTER HALF OF THE WEEKEND. THE
FRONT STALLED ALONG THE COAST SATURDAY WILL GET A PUSH TO THE
SOUTHEAST BY SATURDAY NIGHT WITH COOLER AND DRIER AIR ADVECTING IN
OVERNIGHT SAT INTO SUNDAY. GFS SHOWS A SECONDARY COLD FRONT
EXTENDING DOWN FROM THE GREAT LAKES SAT EVENING. THIS FRONT WILL
PUSH SOUTHEAST DRIVING THE STALLED BOUNDARY TO THE SOUTHEAST AS
HIGH PRESSURE AT THE SURFACE BUILDS IN BEHIND IT BY SUNDAY.
STRONG LOW TO MID LEVEL WINDS OUT OF THE SOUTHWEST WILL KEEP A
DEEPER MOISTURE FEED INTO THE AREA THROUGH MUCH OF SAT
....MAINLY ALONG THE COAST. THIS WILL COMBINE WITH SOME UPPER
LEVEL DYNAMICS TO ENHANCE CHC OF PCP THROUGH AT LEAST EARLY SAT
AFTN. THEREFORE WILL KEEP CLOUDS AND POPS UP THROUGH EARLY SAT
AFTN AS PCP WATER VALUES REMAIN OVER 1.75 INCHES ALONG THE COAST.
EXPECT GREATEST CHC ALONG THE COAST AND WILL SHOW A GRADIENT TO
LOWER END POPS INLAND. EXPECT DRYING TREND THROUGH SAT AFTN INTO
SUNDAY.
AS BROAD MID TO UPPER TROUGH GIVES SECONDARY BOUNDARY A PUSH FROM
THE NW...WINDS WILL VEER AROUND IN THE LOW TO MID LEVELS BECOMING
W-NW AND NORTHERLY AT THE SURFACE THROUGH SAT NIGHT. THIS WILL
BRING PLENTY OF DRY AIR INTO AREA THROUGH THE LOW TO MID LEVELS.
PCP WATER VALUES DROP DOWN TO LESS THAN A HALF INCH THROUGH SUN
MORNING.
THE NORTHERLY SURGE OF DRY AND COOL AIR WILL BRING A GOOD 15 TO
20 DEGREE DROP IN DEWPOINT TEMPS. DEWPOINT TEMPS IN THE MID 60S
EARLY SATURDAY WILL DROP TO LESS THAN 50 DEGREES BY SUNDAY WITH
THE NAM SHOWING VALUES IN THE 30S. THE WINDS ALOFT WILL REMAIN
MORE WESTERLY THROUGH THE PERIOD AS BROAD UPPER TROUGH LIFTS TO
THE NORTHEAST AND RIDGE BUILDS UP FROM FLORIDA. THIS WILL PRODUCE
PLENTY OF DRY AIR AND SUBSIDENCE IN THE MID LEVELS WITH A COOL
NORTHERLY FLOW AT THE SURFACE KEEPING A SHALLOW COOL AIR MASS IN
PLACE ON SUNDAY. THE BROAD UPPER LEVEL FLOW OUT OF THE W-SW WILL
ALLOW SOME HIGH LEVEL MOISTURE AND CIRRUS CLOUDS TO STREAM
IN...BUT OVERALL EXPECT A DRY FALL LIKE SUNDAY.
THE SURFACE HIGH WILL PROGRESS SLOWLY EAST THROUGH EARLY MONDAY
KEEPING A COOL N-NE WIND FLOW. EXPECT FAIRLY DECENT RADIATIONAL
COOLING SUNDAY NIGHT IN CLEAR SKIES AND VERY LIGHT WINDS. THE
GRADIENT MAY REMAIN SLIGHTLY MORE PINCHED ALONG THE COAST ALLOWING
WINDS TO SPIKE UP OVERNIGHT WHICH IN TURN MAY COMBINE WITH WATER
TEMPS AROUND 70 TO KEEP TEMPS RIGHT ALONG THE COAST A LITTLE
HIGHER BUT OVERALL EXPECT TEMPS TO DROP OUT SUNDAY NIGHT WITH
READINGS MAKING IT DOWN NEAR 50 AND SOME 40S IN TRADITIONALLY
COOLER SPOTS ACROSS THE FORECAST AREA. THEREFORE TEMPS WILL START
OUT IN THE MID TO UPPER 70S ON SAT IN CLOUDS AND SHOWERS AND WILL
END IN THE LOW TO MID 70S IN A DRY AND COOLER AIR MASS ON SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...FIRST COLD OUTBREAK OF THE YEAR ANTICIPATED AT
THE END OF THE PERIOD AS A STRONG VORT AND COLD FRONT DIVE ACROSS
THE EASTERN HALF OF THE CONUS.
ONLY CHANCE FOR PRECIP OCCURS LATE MONDAY AND TUESDAY. A WAVE OF LOW
PRESSURE BENEATH A WEAK VORT IMPULSE DEVELOPS ALONG A BOUNDARY
STALLED OFFSHORE. THIS LOW PUSHES THE FRONT BACK TOWARDS THE
COAST...AND ASSOCIATED THETA-E RIDGING AND COLUMN SATURATION OCCURS
FROM SE TO NW. THIS PROMOTES THE POTENTIAL FOR LIGHT RAIN ACROSS THE
AREA...HIGHEST CHANCES ACROSS THE EASTERN HALF OF THE CWA. GFS AND
ECMWF DIFFER IN STRENGTH AND COVERAGE OF RAINFALL...AND WILL LEAN ON
THE DRIER ECMWF WHICH KEEPS THE MAJORITY OF THE RAINFALL OFFSHORE.
STILL...LATE MONDAY INTO EARLY WED WILL BE UNSETTLED WITH
CLOUDS/SHOWERS/AND TEMPS AROUND CLIMO.
SURGE OF COOL AIR PUSHES THE FRONT OFFSHORE BY WEDNESDAY...AND THIS
WILL BE THE LEADING EDGE OF MUCH COOLER AIR FOR THE END OF THE WEEK.
WHILE WEDNESDAY WILL BECOME SUNNY AND DRY...CAA THROUGH THE DAY WILL
KEEP TEMPS BELOW CLIMO. STRONG VORT THEN DIVES TOWARDS THE AREA
THURSDAY...AND IS REINFORCED ON FRIDAY. TEMPS WILL FALL TO WELL
BELOW NORMAL...AND BOTH THE ECMWF/GFS SHOW THE 850MB 0C LINE
APPROACHING THE NW CORNER OF THE CWA...WITH 1000-500MB THICKNESSES
DROPPING INTO THE 550`S. MEX/ECE NUMBERS ARE ALREADY SUGGESTING LOWS
FALLING INTO THE LOW 40S...AND THESE OF COURSE ARE BEING PULLED UP
BY CLIMO. TOO SOON TO SETTLE ON SPECIFICS FOR THE END OF NEXT
WEEK...BUT THE COLDEST AIR OF THE SEASON LOOKS LIKELY HEADING INTO
NEXT WEEKEND.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...FRONTAL BOUNDARY DRAPED OVER THE CWA WITH A MIXTURE OF
LOW AND MIDDLE CLOUDS ONGOING. SKIES WILL BE PREDOMINATELY VFR THIS
AFTERNOON...WITH AREAS OF MVFR. HRRR MODEL SHOWS A BAND OF LIGHT TO
MODERATE CONVECTION DEVELOPING AND TRAVELING NORTHEAST THROUGH
THE CENTRAL PORTION OF THE REGION. WENT WITH VCSH AT ALL TERMINALS
DUE TO THE PROXIMITY OF THE CONVECTION. LIGHT NORTHEAST FLOW WILL
BECOME SOUTHEASTERLY ALONG THE COAST. TONIGHT...SOME UNCERTAINTY
WITH RESPECT TO CEILINGS. STARTING TO LEAN TO THE NAM WHICH IS
MORE PESSIMISTIC WITH BOTH VISIBILITIES AND CEILINGS. COULD SEE
SOME WIDESPREAD IFR CONDITIONS AFTER MIDNIGHT. SATURDAY...FRONTAL
BOUNDARY WAVES BACK TO THE NORTH...WITH MAINLY STRATIFORM
PRECIPITATION EXPECTED ALONG THE COAST WITH SHOWERS MOVING OFF TO
THE NE THROUGH THE DAY.
EXTENDED OUTLOOK...PRECIPITATION ENDING LATE SATURDAY. VFR
DEVELOPING SUNDAY. LIGHT RAIN DEVELOPING TUESDAY MORNING INTO
WEDNESDAY WITH DEVELOPING FRONTAL SYSTEM.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...NO ADVISORIES PLANNED THROUGH DAYBREAK
SATURDAY DESPITE A WAVE OF LOW PRESSURE IMPACTING THE COASTAL
WATERS LATE TONIGHT. WINDS HOWEVER WILL BECOME CHANGEABLE WITH
LIGHT SE FLOW EARLY THIS EVENING...BECOMING SW AND INCREASING
TO 15 KT AND GUSTY AFTER MIDNIGHT AS THE WAVE CENTER MOVES
NEAR CAPE FEAR. SEAS MAINLY 2-3 FEET OVERNIGHT BUT UP TO 4 FT
OFFSHORE BETWEEN MIDNIGHT AND DAYBREAK SATURDAY. ISOLATED TSTMS
WILL BE POSSIBLE OVERNIGHT ACROSS OUR COASTAL WATERS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...A STALLED FRONT WILL KEEP WINDS WEST TO
SOUTHWEST EARLY SATURDAY. AS A WAVE ALONG FRONT MOVES OFF TO THE
NORTHEAST THE WINDS WILL SHIFT MORE WESTERLY THROUGH SAT AFTN, THEN
A SECONDARY BOUNDARY MOVES IN FROM THE NW SAT NIGHT DRIVING THE
STALLED FRONT TO THE SOUTH AND BRINGING WINDS AROUND TO THE NORTH
TO NORTHEAST THROUGH SUNDAY. HIGH PRESSURE WILL BUILD INTO THE
WATERS THROUGH SUNDAY MAINTAINING NORTHERLY WINDS THROUGH SUNDAY.
MODELS SHOWING DECENT SHALLOW COOL AND DRY PUSH WHICH MAY KICK UP
WITH THE SEAS A BIT IN NORTHERLY SURGE EARLY SUNDAY. FOR NOW WILL
HOLD WINDS AT 10 TO 15 KTS BUT MAY SEE A LARGER SPIKE THROUGH
SUNDAY INTO EARLY MONDAY. SEAS WILL SPIKE UP SAT MORNING AND AGAIN
SUNDAY...BUT SHOULD REMAIN LESS THAN 4 FT.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...SHIFTING WINDS MON AND TUE WILL FORTUNATELY
REMAIN RATHER LIGHT...AROUND 10 KTS (ALTHOUGH BRIEF INCREASE TO 15
KTS POSSIBLE EARLY IN THE PERIOD)...SHIFTING FROM NE MUCH OF
MONDAY...TO LIGHT AND VARIABLE...AND THEN W/NW ON TUESDAY. THESE
SHIFTING WINDS ARE DUE TO A STALLED BOUNDARY WHICH WILL WAVER NEAR
THE WATERS AS A WEAK LOW PRESSURE MOVES ALONG IT. AS THIS LOW MOVES
AWAY ON WEDNESDAY...IT DRAGS THE FRONT BACK SE AS A COLD
FRONT...WITH WINDS INCREASING TO 10-15 KTS FROM THE NW. WAVE HEIGHTS
WILL BE 2-3 FT EACH DAY THROUGH THE PERIOD...BUT WITH A WIND WAVE
SHIFTING TO FOLLOW THE MEAN DIRECTION EACH DAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 3 PM FRIDAY...CFW ISSUED FOR THE CAPE FEAR AT DOWNTOWN
WILMINGTON FOR MINOR FLOODING DUE TO ELEVATED ASTRONOMICAL TIDES.
THIS WILL BE COINCIDENT WITH THIS EVENINGS HIGH TIDE AND THE
ADVISORY WILL RUN FROM 9PM-11PM AS SEVERAL INCHES OF WATER BEGINS
TO COVER WATER STREET AND THE BATTLESHIP AREA...AND OTHER LOW-
LYING LOCATIONS ALONG THE LOWER CAPE FEAR RIVER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 9 PM TO 11 PM EDT THIS EVENING FOR
NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...MJC/DL
TIDES/COASTAL FLOODING...MJC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
100 PM EDT FRI OCT 18 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING AND THEN STALL
JUST OFFSHORE AS A WAVE OF LOW PRESSURE DEVELOPS TO OUR SOUTH AND
LIFTS NORTHEAST ALONG THE FRONT AND ACROSS THE AREA TONIGHT AND
SATURDAY MORNING. HIGH PRESSURE WILL FORCE THE FRONT TO OUR SOUTH
SUNDAY AND MONDAY. HIGH PRESSURE WILL MOVE OFFSHORE MONDAY NIGHT
AND TUESDAY AND THIS MAY ALLOW THE FRONT TO OUR SOUTH TO RETURN
NORTHWARD. A LARGE AREA OF COOL HIGH PRESSURE WILL SLOWLY BUILD
INTO THE AREA LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM FRIDAY...VARIABLE CLOUDINESS WILL STRADDLE THE
CENTRAL ZONES THIS MORNING AS BREAKS IN THE OVERCAST SAIL SWIFTLY
OVERHEAD FROM SW TO NE...BUT MOSTLY CLOUDY SKY CONDITION APPEARS
STILL ON TARGET FOR TODAY. THE CLOUD BREAKS ARE DISCONCERTING WITH
REGARD TO MAXIMUM TEMPERATURE FORECASTS TODAY...BUT MID AND MAYBE
A FEW UPPER 70S STILL LOOKS GOOD SINCE SUNSHINE WILL NOT LAST LONG
IN ANY ONE LOCATION. VWP SHOWING WSW WIND 20-30 KT BETWEEN 800-700
MB PRESENTLY. A RIBBON OF HIGH PRECIPITABLE WATER WAS STREAMING SW
TO NE WITH TROPICAL REMNANTS OF PACIFIC SYSTEM OCTAVE IN THE MIX.
CHS REPORTED 1.85 PWAT VALUES WITH THE 12Z UPPER AIR SOUNDING.
FORCING WILL REMAIN WEAK TODAY WITH ISOLATED SHOWERS ANTICIPATED.
FARTHER INLAND WEAK ISENTROPIC LIFT MAY RESULT IN LOWER CEILINGS
AND -RA/DZ ALONG THE LEADING EDGE OF HIGH PRESSURE BUILDING IN
BEHIND THE FRONT OVER OUR WESTERN AND NORTHERN ZONES...ALTHOUGH
AGAIN LOW QPFS EXPECTED MUCH OF TODAY.
TONIGHT UNFOLDS WITH A BUMP UPWARD IN RAIN CHANCES AND AMOUNTS AS
LOW-LEVEL CONVERGENCE INCREASES IN VICINITY OF A WAVE OF SURFACE
LOW PRESSURE ALONG THE FRONT. HOWEVER SINCE THIS FEATURE MAY
RESIDE OVER THE COASTAL WATERS WHILE MIGRATING NE...SHOWERS SHOULD
BECOME MOST FAVORED ALONG AND NEAR THE COASTAL ZONES TONIGHT INTO
SATURDAY MORNING WHERE HIGHER RAINFALL AMOUNTS COULD OCCUR DUE TO
THE RICH AMOUNTS OF MOISTURE AVAILABLE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...THE WEEKEND WILL SEE ONE WET DAY AND ONE DRY DAY
AS A FRONT AND MID LEVEL FORCING IMPACT THE AREA SATURDAY. 0000 UTC
GUIDANCE HAD TRENDED WETTER FOR SATURDAY ESPECIALLY ALONG COASTAL
AREAS VIA MID LEVEL FORCING COMPRISED OF JET DYNAMICS COUPLED WITH A
SURFACE FRONT. MOISTURE PROFILES HAVE SHAPED UP AS WELL WITH
PRECIPITABLE WATER VALUES NEARING TWO INCHES ALBEIT BRIEFLY ALONG
THE COAST. THIS SEEMS PLAUSIBLE LOOKING AT WATER VAPOR LOOPS
UPSTREAM. I INCREMENTALLY INCREASED THE ALREADY LIKELY POPS ALONG
THE COAST TO REPRESENT THIS TREND AND INCREASED POPS TO CHANCE
INLAND. THE BIG DIFFERENCE WILL BE QPF AMOUNTS WHICH WILL LIKELY BE
PALTRY INLAND BUT THE COASTAL AREAS COULD SCORE ONE HALF TO ONE
INCH. MODELS HAVE TRENDED DRIER FOR SUNDAY AND HAVE REMOVED ANY
MENTION OF POPS FOR SUNDAY AND SCALED BACK CLOUD COVER. HOWEVER WITH
THE SUBTROPICAL JET/SOUTHWEST FLOW INTACT AREAS OF MID AND HIGH
LEVEL CLOUDS WILL PRECLUDE A SUNNY TO MOSTLY SUNNY DAY. I MADE ONLY
MINOR MODIFICATIONS TO THE TEMPERATURE FORECAST WALKING BACK HIGHS
SATURDAY CITING THE INCREASED POPS. JUST THE OPPOSITE FOR SUNDAY
WITH DRIER CONDITIONS THEREFORE I TRENDED SLIGHTLY WARMER.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...MEDIUM RANGE GUIDANCE CONTINUES TO SHOW A BROAD
CYCLONIC FLOW ACROSS THE LOWER 48 THROUGH THE PERIOD. WE MAY GET
BRUSHED BY A SYSTEM THAT MOVES QUICKLY THROUGH THE SUBTROPICAL JET
LATE MONDAY AND TUESDAY AND LOW CHANCE POPS REMAIN IN THE FORECAST
FOR THIS TIME. INLAND COUNTIES MAY NOT SEE ANY IMPACTS FROM THIS
FEATURE. AFTER THIS A POTENT VORT DEEPENS THE LONG WAVE TROUGH AND
BRINGS ALONG WITH IT SOME OF THE COOLEST AIR OF THE SEASON. 850MB
TEMPERATURES AT LEAST FROM THE GFS DROP TO JUST OVER THE FREEZING
LEVEL. AS USUAL A MIXED BOUNDARY LAYER WILL MITIGATE MORNING LOWS
BUT PROBABLY A BIT TOO FAR OUT IN TIME TO FINE TUNE TEMPERATURES IN
DEPTH.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...FRONTAL BOUNDARY DRAPED OVER THE CWA WITH A MIXTURE OF
LOW AND MIDDLE CLOUDS ONGOING. SKIES WILL BE PREDOMINATELY VFR THIS
AFTERNOON...WITH AREAS OF MVFR. HRRR MODEL SHOWS A BAND OF LIGHT TO
MODERATE CONVECTION DEVELOPING AND TRAVELING NORTHEAST THROUGH
THE CENTRAL PORTION OF THE REGION. WENT WITH VCSH AT ALL TERMINALS
DUE TO THE PROXIMITY OF THE CONVECTION. LIGHT NORTHEAST FLOW WILL
BECOME SOUTHEASTERLY ALONG THE COAST. TONIGHT...SOME UNCERTAINTY
WITH RESPECT TO CEILINGS. STARTING TO LEAN TO THE NAM WHICH IS
MORE PESSIMISTIC WITH BOTH VISIBILITIES AND CEILINGS. COULD SEE
SOME WIDESPREAD IFR CONDITIONS AFTER MIDNIGHT. SATURDAY...FRONTAL
BOUNDARY WAVES BACK TO THE NORTH...WITH MAINLY STRATIFORM
PRECIPITATION EXPECTED ALONG THE COAST WITH SHOWERS MOVING OFF TO
THE NE THROUGH THE DAY.
EXTENDED OUTLOOK...PRECIPITATION ENDING LATE SATURDAY. VFR
DEVELOPING SUNDAY. LIGHT RAIN DEVELOPING TUESDAY MORNING INTO
WEDNESDAY WITH DEVELOPING FRONTAL SYSTEM.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM FRIDAY...A COLD FRONT WILL STALL NEAR THE COAST AS A
WAVE OF LOW PRESSURE BEGINS TO DEVELOP TO OUR S LATER TODAY. THE
FRONT WILL LIKELY RETROGRADE SLIGHTLY AS THE WAVE MIGRATES NE
ACROSS THE AREA TONIGHT. THIS WILL MAKE FOR A DIFFICULT WIND
DIRECTION FORECAST. WINDS ARE EXPECTED TO VEER TO THE N LATER THIS
MORNING. WINDS WILL BE FROM THE NE OR ENE FOR THE AFTERNOON HOURS
AND THEN VEER ALL THE WAY AROUND TO S AND SW OVERNIGHT. WIND
SPEEDS WILL BE 10 KT OR LESS...PERHAPS AS HIGH AS 10 TO 15 KT
TOWARD MORNING ACROSS THE OUTER WATERS ALONG AND AHEAD OF THE WAVE
OF LOW PRESSURE. SEAS WILL BE 2 TO 3 FT...WITH AROUND 4 FT AT
FRYING PAN SHOALS BUOY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...A STALLED FRONT WILL KEEP WINDS WEST TO
SOUTHWEST EARLY SATURDAY. AS A WAVE DEVELOPS AND MOVES TO THE
NORTHEAST OF THE AREA LATER IN THE DAY...WINDS WILL TAKE A MORE
CONSISTENT WESTERLY DIRECTION. WITH CLOUD COVER KEEPING SURFACE
TEMPERATURES IN CHECK...THE SEABREEZE SHOULD NOT DEVELOP. SPEEDS
WILL HOVER AROUND TEN KNOTS. HIGH PRESSURE...INITIALLY OVER THE
TENNESSEE VALLEY MOVES CLOSER SUNDAY TURNING WINDS TO THE NORTHEAST.
WITH SUBTLE COLD AIR ADVECTION...SPEEDS INCREASE TO 10-15 KNOTS BUT
PROBABLY MORE TOWARD THE LOWER END OF THE RANGE.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...INITIALLY WINDS WILL BE FROM THE NORTHEAST
ACROSS THE COASTAL WATERS IN A RANGE OF 10-15 KNOTS. WIND FIELDS
WILL DECREASE THROUGH THE DAY MONDAY INTO TUESDAY MORNING AS THE
GRADIENT WEAKENS CONSIDERABLY. LOW PRESSURE WILL MOVE WELL OFFSHORE
DURING THIS TIME. WINDS MAY NEED TO BE ADJUSTED DEPENDING ON THE
EXACT TRACK AND STRENGTH OF THIS FEATURE. A NORTHERLY FLOW WILL
ENSUE AFTER THE LOW MOVES BY AT THE END OF THE PERIOD. MODEST WIND
FIELDS CONTINUE TO EQUATE TO MINIMAL SEAS WITH GENERALLY 1-3 FEET.
&&
.TIDES/COASTAL FLOODING...
AS OF 3 AM FRIDAY...A COASTAL FLOOD ADVISORY IS IN EFFECT THIS
MORNING FOR PORTIONS OF THE CAPE FEAR RIVER. THE DOWNTOWN WILMINGTON
TIDE GAUGE IS EXPECTED TO PEAK AT ABOUT 6 FT. HIGH TIDE ALONG THE
RIVER IS AT 930 AM. ALONG THE BEACHES...WATER LEVELS WILL BE
ELEVATED ONCE AGAIN AND ACTION STAGES WILL LIKELY BE REACHED.
HOWEVER... GAUGES ARE NOT EXPECTED TO REACH MINOR COASTAL FLOOD
THRESHOLDS. HOWEVER...THERE MAY BE A FEW VERY LOW SPOTS NEAR THE
IMMEDIATE COAST THAT EXPERIENCE PONDING OF SALT WATER BETWEEN 630
AND 830 AM AS THE WATER COMES WELL UP ONTO THE BEACHES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL/MJC
TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
524 PM CDT FRI OCT 18 2013
.UPDATE...
ISSUED AT 524 PM CDT FRI OCT 18 2013
LATEST WATER VAPOR SHOWS A SHORTWAVE ALONG THE SOUTHERN SASKATCHEWAN
AND MANITOBA BORDER DIVING SOUTH WITH TIME. AN AREA OF VERTICAL
MOTION/H85-H3 OMEGA AHEAD OF THIS WAVE CONTINUES TO RESULT IN
SURFACE PRESSURE FALLS AND SCATTERED RAINSHOWERS IN NORTH CENTRAL
NORTH DAKOTA. THE LATEST HRRR FORECASTS THIS AREA TO SHIFT SOUTH
AND INCREASE IN AREAL COVERAGE FOR SOUTH CENTRAL NORTH DAKOTA
THROUGH 04Z. CONCUR WITH THIS IDEA PER LATEST RADAR RETURNS. THERE
COULD BE SOME SNOW OR GRAUPEL WITHIN HEAVIER CONVECTIVE SHOWERS
THIS EVENING AS THE SHALLOW SURFACE WARM LAYER COOLS WITH SUPERCOOLED
WATER DROPLETS DOMINATING ABOVE. MAIN FORECAST REMAINS ON TRACK
WITH MINOR UPDATES TO HOURLY GRIDDED DATA.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 251 PM CDT FRI OCT 18 2013
SMALL POCKETS OF LIGHT RAIN WILL CONTINUE TO DEVELOP AND PUSH
SOUTHEAST THROUGH THE AFTERNOON HOURS. THE HIGHEST PRECIPITATION
COVERAGE IS EXPECTED NORTHEAST OF A LINE FROM KENMARE TO BISMARCK AND
ELLENDALE. AS NEAR SURFACE TEMPS DROP OFF TONIGHT...EXPECT RAIN TO
BECOME MIXED WITH OR CHANGE OVER TO ALL SNOW. THERE MAY BE SOME
VERY MINOR ACCUMULATIONS ON GRASSY SURFACES...MAINLY FROM
BOTTINEAU...TO CARRINGTON AND JAMESTOWN.
ON SATURDAY...A WARM FRONT WILL PUSH INTO WESTERN NORTH DAKOTA
DURING THE MORNING HOURS. A BAROCLINIC ZONE NEAR THE BOUNDARY MAY
BE ENOUGH TO SUPPORT A FEW LIGHT SNOW SHOWERS...MAINLY DURING THE
MORNING HOURS. AGAIN...LITTLE OR NO ACCUMULATION IS EXPECTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 251 PM CDT FRI OCT 18 2013
THE LONG TERM FORECAST WILL BE DOMINATED BY NORTH/NORTHWEST FLOW
ALOFT WITH A TROUGH OVER EASTERN CANADA/US AND A WESTERN RIDGE OVER
WESTERN CANADA/US.
THE MAIN FOCUS IN THE LONG TERM WILL BE SNOW AMOUNTS IN THE
NORTHEAST PART OF THE FORECAST AREA...BOTTINEAU-ROLLA-RUGBY-HARVEY
LATE SATURDAY NIGHT INTO SUNDAY MORNING. OTHER THAN THAT THERE WILL
BE A CHANCE OF LIGHT PRECIPITATION MONDAY/MONDAY NIGHT.
REGARDING THIS SATURDAY NIGHT/SUNDAY CLIPPER EVENT...TODAY`S MODELS
ARE INDICATING WARM AIR ADVECTION AHEAD OF THE SURFACE CLIPPER -
ENOUGH SUCH THAT PRECIPITATION SATURDAY EVENING AND INTO VERY EARLY
SUNDAY MORNING WOULD BE AHEAD AND EAST OF THE SURFACE LOW AND IN THE
FORM OF RAIN. RAIN WOULD NOT BE CHANGING TO SNOW UNTIL ROUGHLY 3 AM
IN THE TURTLE MOUNTAINS...THOUGH FARTHER WEST THE CHANGE TO SNOW MAY
OCCUR AROUND MIDNIGHT SATURDAY NIGHT. A GOOD AMOUNT OF THE
PRECIPITATION ASSOCIATED WITH THIS SYSTEM IS PROGGED TO BEGIN LATE
AFTERNOON/EARLY EVENING...WITH THE BEST LIFT AND MORE INTENSE
PRECIPITATION OCCURRING BEFORE MIDNIGHT. THE SURFACE LOW IS PROGGED
TO MOVE SOUTH FROM SASKATCHEWAN AND CROSS THE NORTH DAKOTA BORDER
BETWEEN 10 PM AND MIDNIGHT. THUS THE BULK OF THE ASSOCIATED
PRECIPITATION SHOULD BE IN THE FORM OF RAIN.
REGARDING SNOW AMOUNTS...THE LATEST EXPECTATION IS THAT THE TURTLE
MOUNTAINS MAY RECEIVE UP TO 2 INCHES OF SNOW FROM SATURDAY NIGHT
THROUGH SUNDAY...WITH HALF AN INCH TO AN INCH IN THE SURROUNDING
AREAS FROM BOTTINEAU TO NORTHERN MCHENRY TO PIERCE COUNTIES. LESSER
AMOUNTS EXPECTED ACROSS NORTHWESTERN NORTH DAKOTA TO THE NORTHERN
JAMES RIVER VALLEY.
WINDY AS WELL SATURDAY NIGHT AND SUNDAY AS THE CLIPPER LOW MOVES
FROM THE NORTH CENTRAL TO SOUTHEASTERN NORTH DAKOTA. NORTHWEST WINDS
OF 20 TO 30 MPH EARLY SUNDAY MORNING IN THE WEST...AND DAYTIME
SUNDAY OVER WESTERN AND CENTRAL NORTH DAKOTA.
A NEXT WEAKER WAVE IS THROUGH ON MONDAY / TUESDAY...FOLLOWED BY THE
BUILDING H5 RIDGE WITH DRIER AND MORE SEASONAL TEMPERATURES. THE
REST OF THE LONG TERM WILL SEE HIGHS IN THE 30S AND 40S OVER CENTRAL
NORTH DAKOTA...AND 40S TO LOWER 50S OVER WESTERN NORTH DAKOTA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 524 PM CDT FRI OCT 18 2013
LOW VFR TO MVFR CIGS NEXT 24HR AS ISOLATED TO SCATTERED RAIN AND
SNOW SHOWERS MOVE FROM NORTH TO SOUTH. FOR THURSDAY EVENING...IT
APPEARS KBIS/KJMS WILL HAVE THE HIGHEST PROBABILITY FOR SHOWERS
WITH A VCSH IN THE REST OF THE TERMINALS. CIGS WILL LIFT TO VFR
SATURDAY AFTERNOON AS A WARM FRONT MOVES THROUGH CENTRAL NORTH
DAKOTA.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...RP KINNEY
LONG TERM...JV
AVIATION...KS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1132 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION THIS EVENING FOLLOWED
BY A VISIT FROM HIGH PRESSURE ON SUNDAY AND MONDAY. THE PATTERN
WILL TURN NOTICEABLY COOLER AND UNSETTLED NEXT WEEK AS AN UPPER
TROUGH ESTABLISHES ITSELF OVER THE EASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
REGIONAL RADAR LOOP AT 02Z SHOWS A DWINDLING LINE OF SHOWERS
ASSOC WITH COLD FRONT ENTERING THE SUSQ VALLEY. DESPITE A DECENT
AMT OF MOISTURE POOLING AHEAD OF FRONT...UPPER LVL SHORTWAVE AND
ASSOC LG SCALE FORCING IS LIFTING NORTH OF THE BORDER...SO LITTLE
CHC OF MORE THAN AN ISOLD SHOWER AS FRONT PUSHES THRU THE EASTERN
COUNTIES BTWN 02Z-04Z. LATEST RAP OUTPUT INDICATES CDFRONT WILL
CLEAR THE EASTERNMOST COUNTIES /SCHUYLKILL AND LANCASTER/ BY
MIDNIGHT. BEHIND FRONT...ONLY REMAINING PRECIP WILL BE IN THE
FORM OF LAKE EFFECT RAIN SHOWERS COMING OFF OF LK ERIE. CURRENT
RADAR TRENDS AND RAP/NAM OUTPUT SUGGEST SHOWERS ACROSS
WARREN/MCKEAN COS WILL SHIFT NORTH OF THE BORDER AFTER 06Z...AS
BLYR FLOW BACKS TO THE WSW.
CLEARING SKIES ALREADY DEVELOPING EAST OF THE MTNS AT 02Z AND
EXPECT THAT TREND TO CONTINUE OVERNIGHT...AS DRIER WEST FLOW
OVERSPREADS CENTRAL PA. STRATOCU MAY LINGER FOR A WHILE ACROSS THE
LAUREL HIGHLANDS...BUT EXPECT CLEARING EVEN THERE LATE TONIGHT.
THE INITIALLY GUSTY WEST WINDS SHOULD SLACKEN LATE TONIGHT...AS
HIGH PRES RIDGE BUILDS IN FROM THE OHIO VALLEY. BLEND OF LATEST
LAMP AND RAP GUIDANCE SUGGEST TEMPS WILL BOTTOM OUT IN THE M30S
ACROSS THE ALLEGHENY PLATEAU...TO THE L40S OVR THE SUSQ VALLEY.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE WILL PASS JUST SOUTH OF THE STATE ON SUNDAY...PROVIDING
THE AREA WITH SEASONABLY COOL AND DRY WX. ALTHOUGH A WSW BLYR FLOW
WILL KEEP LINGERING LAKE EFFECT ACTIVITY NORTH OF THE
BORDER...COLD TEMPS ALOFT SHOULD YIELD A GOOD AMT OF DIURNAL
STRATOCU ACROSS THE NW MTNS. WIND WILL INCREASE A BIT FROM A MORNING
LULL...AS THE ATMOS MIXES. MDL SOUNDINGS SUPPORT AFTN GUSTS BTWN
20-25KTS ACROSS THE NW MTNS...AND BTWN 10-15KTS ACROSS THE LOWER
SUSQ VALLEY.
HIGH TEMPS UNDER THE RATHER HOMOGENEOUS 0C-M2C 8H TEMPS WILL BE
ALMOST ENTIRELY DEPENDENT ON ELEVATION AND DOWNSLOPE WARMING.
MAXES SHOULD BE CLOSE TO 50F IN THE NW MTNS AND NEAR 60F IN THE
VALLEYS/LOWER ELEVS OF THE SUSQ VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
CENTRAL PA WILL BE ON NORTHERN EDGE OF ERODING HIGH PRESSURE RIDGE
SUN NIGHT INTO MON...WITH A WARM FRONT LIFTING THROUGH OHIO VALLEY
AND SKIRTING W PA. THIS WILL KEEP WEATHER FAIR AND MILD...WITH
HIGHS MONDAY SLIPPING INTO THE 60S /ABOUT 4-8F ABOVE NORMAL/.
THINGS START TO GO DOWNHILL MONDAY NIGHT AS NEW ENERGY STARTS
DIVING OUT OF SOUTHERN CANADA ON THE WAY TO CARVING OUT A LARGE
SCALE PERSISTENT TROF OVER THE EASTERN U.S. A BUILDING RIDGE OVER
THE WEST COAST WILL HELP DEEPEN AN ADVANCING LOW...WHICH WILL
DELIVER A STEADY FEED OF INCREASINGLY MORE CHILLY AIR ACROSS THE
UPPER MIDWEST NEXT WEEK. THIS COLD AIR WILL PROPAGATE INTO THE
LOWER LAKES AND LOCAL AREA IN THE WAKE OF A COLD FRONTAL BOUNDARY
PROGGED FOR TUESDAY...AND REINFORCED BY SECONDARY TROUGH ON
WEDNESDAY /AS ANOTHER LOW FORMS ALONG THE BOUNDARY AND SLIDES
ACROSS MID ATLANTIC STATES JUST TO OUR SOUTH BEFORE SLIDING OFF
THE COAST OF NEW ENGLAND/.
SOME DIFFERENCES CONTINUE IN MODEL SOLUTIONS STARTING AROUND
WEDNESDAY WHEN THE ECMWF BRINGS A STRONG SHORTWAVE OUT OF THE
OHIO VALLEY. THE OPERATIONAL GFS AND THE GEFS /PREVIOUSLY WITH A
FLATTER TROUGH/ ARE COMING MORE IN LINE WITH THE EC...WHICH WILL
INCREASE OUR POP CHANCES FOR WED WITH A STEADY LIGHT RAIN POSS.
AFTER THAT...CYCLONIC FLOW WILL CONTINUE TO ALLOW INCREASINGLY
COOLER AIR TO FILTER IN ON NW FLOW. PLENTY OF COLD ADVECTION
STRATOCU AND LAKE/OROGRAPHIC SHOWERS LOOKING LIKELY IN THE HIGHER
WESTERN TERRAIN MID/LATE WEEK...WITH DOWNSLOPE COMPONENT TO WINDS
KEEPING PRECIP AT A MIN FOR THE SE. LOW LEVEL TEMPS GET COLD
ENOUGH /850MB TEMPS DIP BELOW 0C/ THAT LIGHT SHOWERS COULD BE
MIXED WITH WET SNOW DURING THE CHILLIEST PART OF THE DAY AND
OVERNIGHT.
HIGH PRESSURE BUILDS IN LOW LEVELS FOR THE WEEKEND...BRINGING
QUITE CHILLY MORNING TEMPS. BUT AN OVERALL MORE SETTLED WEATHER
PATTERN. REINFORCING SHOT OF COLDER AIR POSS EARLY NEXT WEEK.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
COLD FRONT JUST ABOUT TO CLEAR LAST OF TAF LOCATIONS OF KMDT AND
KLNS DURING THE NEXT HOUR. A BAND OF MVFR TO ISOLATED IFR CIGS
ACCOMPANIES THE FRONT...AND EXTENDS FOR 75 TO 100 MILES BEHIND
THE FRONT. THIS BAND OF CLOUDS WILL CONTINUE TO SWEEP
EASTWARD...AND EXPECT MOST AIRFIELDS TO RETURN TO VFR CONDITIONS
BETWEEN 04Z AND 08Z. EXCEPTION WILL BE KBFD...WHERE LAKE EFFECT
SHOWERS CONTINUE TO STREAM ACROSS THE NORTHWEST COUNTIES. THIS
WILL KEEP MVFR TO IFR CIGS OVER KBFD MOST OF THE NIGHT. WHILE
KJST HAS CLEARED AS OF 04Z...WILL HAVE TO WATCH FOR REDEVELOPMENT
OF LOWER CLOUDS WITH MOIST UPSLOPE WESTERLY FLOW FOR THE NEXT
SEVERAL HOURS.
ON SUNDAY...HIGH PRESSURE BUILDS IN WEST OF THE AREA FROM THE
TENNESSEE VALLEY...BUT STAYS FAR ENOUGH AWAY TO KEEP SOME GRADIENT
WIND...GENERALLY 10 TO 15 KTS...DURING THE DAY. OTHERWISE...AFTER
SOME LINGERING LOWER CIGS EARLY AT KBFD AND KJST...VFR CONDITIONS
EXPECTED SUNDAY.
MONDAY LOOKS FAIR/VFR AS HIGH PRESSURE SLIDES TO THE EAST COAST
AND RETURN FLOW BEGINS. MORE COLD AIR ARRIVES WITH THE NEXT COLD
FRONT MON NIGHT AND TUESDAY.
OUTLOOK...
TUE...FROPA. MVFR/IFR POSS DUE TO SHOWERS/CLOUDS...ESP NW.
WED...MVFR POSS IN SHRA...ESP NW.
THURS...BREEZY...MVFR CLOUDS/SHRA N/W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO/FITZGERALD
LONG TERM...RXR
AVIATION...JUNG
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1035 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION THIS EVENING FOLLOWED
BY A VISIT FROM HIGH PRESSURE ON SUNDAY AND MONDAY. THE PATTERN
WILL TURN NOTICEABLY COOLER AND UNSETTLED NEXT WEEK AS AN UPPER
TROUGH ESTABLISHES ITSELF OVER THE EASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
REGIONAL RADAR LOOP AT 02Z SHOWS A DWINDLING LINE OF SHOWERS
ASSOC WITH COLD FRONT ENTERING THE SUSQ VALLEY. DESPITE A DECENT
AMT OF MOISTURE POOLING AHEAD OF FRONT...UPPER LVL SHORTWAVE AND
ASSOC LG SCALE FORCING IS LIFTING NORTH OF THE BORDER...SO LITTLE
CHC OF MORE THAN AN ISOLD SHOWER AS FRONT PUSHES THRU THE EASTERN
COUNTIES BTWN 02Z-04Z. LATEST RAP OUTPUT INDICATES CDFRONT WILL
CLEAR THE EASTERNMOST COUNTIES /SCHUYLKILL AND LANCASTER/ BY
MIDNIGHT. BEHIND FRONT...ONLY REMAINING PRECIP WILL BE IN THE
FORM OF LAKE EFFECT RAIN SHOWERS COMING OFF OF LK ERIE. CURRENT
RADAR TRENDS AND RAP/NAM OUTPUT SUGGEST SHOWERS ACROSS
WARREN/MCKEAN COS WILL SHIFT NORTH OF THE BORDER AFTER 06Z...AS
BLYR FLOW BACKS TO THE WSW.
CLEARING SKIES ALREADY DEVELOPING EAST OF THE MTNS AT 02Z AND
EXPECT THAT TREND TO CONTINUE OVERNIGHT...AS DRIER WEST FLOW
OVERSPREADS CENTRAL PA. STRATOCU MAY LINGER FOR A WHILE ACROSS THE
LAUREL HIGHLANDS...BUT EXPECT CLEARING EVEN THERE LATE TONIGHT.
THE INITIALLY GUSTY WEST WINDS SHOULD SLACKEN LATE TONIGHT...AS
HIGH PRES RIDGE BUILDS IN FROM THE OHIO VALLEY. BLEND OF LATEST
LAMP AND RAP GUIDANCE SUGGEST TEMPS WILL BOTTOM OUT IN THE M30S
ACROSS THE ALLEGHENY PLATEAU...TO THE L40S OVR THE SUSQ VALLEY.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE WILL PASS JUST SOUTH OF THE STATE ON SUNDAY...PROVIDING
THE AREA WITH SEASONABLY COOL AND DRY WX. ALTHOUGH A WSW BLYR FLOW
WILL KEEP LINGERING LAKE EFFECT ACTIVITY NORTH OF THE
BORDER...COLD TEMPS ALOFT SHOULD YIELD A GOOD AMT OF DIURNAL
STRATOCU ACROSS THE NW MTNS. WIND WILL INCREASE A BIT FROM A MORNING
LULL...AS THE ATMOS MIXES. MDL SOUNDINGS SUPPORT AFTN GUSTS BTWN
20-25KTS ACROSS THE NW MTNS...AND BTWN 10-15KTS ACROSS THE LOWER
SUSQ VALLEY.
HIGH TEMPS UNDER THE RATHER HOMOGENEOUS 0C-M2C 8H TEMPS WILL BE
ALMOST ENTIRELY DEPENDENT ON ELEVATION AND DOWNSLOPE WARMING.
MAXES SHOULD BE CLOSE TO 50F IN THE NW MTNS AND NEAR 60F IN THE
VALLEYS/LOWER ELEVS OF THE SUSQ VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
CENTRAL PA WILL BE ON NORTHERN EDGE OF ERODING HIGH PRESSURE RIDGE
SUN NIGHT INTO MON...WITH A WARM FRONT LIFTING THROUGH OHIO VALLEY
AND SKIRTING W PA. THIS WILL KEEP WEATHER FAIR AND MILD...WITH
HIGHS MONDAY SLIPPING INTO THE 60S /ABOUT 4-8F ABOVE NORMAL/.
THINGS START TO GO DOWNHILL MONDAY NIGHT AS NEW ENERGY STARTS
DIVING OUT OF SOUTHERN CANADA ON THE WAY TO CARVING OUT A LARGE
SCALE PERSISTENT TROF OVER THE EASTERN U.S. A BUILDING RIDGE OVER
THE WEST COAST WILL HELP DEEPEN AN ADVANCING LOW...WHICH WILL
DELIVER A STEADY FEED OF INCREASINGLY MORE CHILLY AIR ACROSS THE
UPPER MIDWEST NEXT WEEK. THIS COLD AIR WILL PROPAGATE INTO THE
LOWER LAKES AND LOCAL AREA IN THE WAKE OF A COLD FRONTAL BOUNDARY
PROGGED FOR TUESDAY...AND REINFORCED BY SECONDARY TROUGH ON
WEDNESDAY /AS ANOTHER LOW FORMS ALONG THE BOUNDARY AND SLIDES
ACROSS MID ATLANTIC STATES JUST TO OUR SOUTH BEFORE SLIDING OFF
THE COAST OF NEW ENGLAND/.
SOME DIFFERENCES CONTINUE IN MODEL SOLUTIONS STARTING AROUND
WEDNESDAY WHEN THE ECMWF BRINGS A STRONG SHORTWAVE OUT OF THE
OHIO VALLEY. THE OPERATIONAL GFS AND THE GEFS /PREVIOUSLY WITH A
FLATTER TROUGH/ ARE COMING MORE IN LINE WITH THE EC...WHICH WILL
INCREASE OUR POP CHANCES FOR WED WITH A STEADY LIGHT RAIN POSS.
AFTER THAT...CYCLONIC FLOW WILL CONTINUE TO ALLOW INCREASINGLY
COOLER AIR TO FILTER IN ON NW FLOW. PLENTY OF COLD ADVECTION
STRATOCU AND LAKE/OROGRAPHIC SHOWERS LOOKING LIKELY IN THE HIGHER
WESTERN TERRAIN MID/LATE WEEK...WITH DOWNSLOPE COMPONENT TO WINDS
KEEPING PRECIP AT A MIN FOR THE SE. LOW LEVEL TEMPS GET COLD
ENOUGH /850MB TEMPS DIP BELOW 0C/ THAT LIGHT SHOWERS COULD BE
MIXED WITH WET SNOW DURING THE CHILLIEST PART OF THE DAY AND
OVERNIGHT.
HIGH PRESSURE BUILDS IN LOW LEVELS FOR THE WEEKEND...BRINGING
QUITE CHILLY MORNING TEMPS. BUT AN OVERALL MORE SETTLED WEATHER
PATTERN. REINFORCING SHOT OF COLDER AIR POSS EARLY NEXT WEEK.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
COLD FRONT EVIDENT ON RADAR THIS EVENING...EXTENDING FROM ABOUT
KBFD TO KJST AT 00Z. FRONT WILL SWEEP THROUGH CENTRAL AIRFIELDS
DURING THE NEXT 3 HOURS OR SO. EXPECT A BAND OF MVFR TO ISOLATED
IFR CIGS TO ACCOMPANY THE FRONT. PRECIPITATION SHOULD END RAPIDLY
AFTER FROPA...WITH IMPROVING CIGS. DO EXPECT MVFR CIGS TO PERSIST
IN KBFD AND KJST WELL AFTER MIDNIGHT...WITH MOIST UPSLOPE WESTERLY
FLOW.
ON SUNDAY...HIGH PRESSURE BUILDS IN WEST OF THE AREA FROM THE
TENNESSEE VALLEY...BUT STAYS FAR ENOUGH AWAY TO KEEP SOME GRADIENT
WIND...GENERALLY 10 TO 15 KTS...DURING THE DAY. OTHERWISE...AFTER
SOME LINGERING LOWER CIGS EARLY AT KBFD AND KJST...VFR CONDITIONS
EXPECTED SUNDAY.
MONDAY LOOKS FAIR/VFR AS HIGH PRESSURE SLIDES TO THE EAST COAST
AND RETURN FLOW BEGINS. MORE COLD AIR ARRIVES WITH THE NEXT COLD
FRONT MON NIGHT AND TUESDAY.
OUTLOOK...
TUE...FROPA. MVFR/IFR POSS DUE TO SHOWERS/CLOUDS...ESP NW.
WED...MVFR POSS IN SHRA...ESP NW.
THURS...BREEZY...MVFR CLOUDS/SHRA N/W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO/FITZGERALD
LONG TERM...RXR
AVIATION...JUNG
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
909 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION THIS EVENING FOLLOWED
BY A VISIT FROM HIGH PRESSURE ON SUNDAY AND MONDAY. THE PATTERN
WILL TURN NOTICEABLY COOLER AND UNSETTLED NEXT WEEK AS AN UPPER
TROUGH ESTABLISHES ITSELF OVER THE EASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
EVENING REGIONAL RADAR LOOP SHOWS A DWINDLING LINE OF SHOWERS
ASSOC WITH COLD FRONT OVR THE CENTRAL MTNS. DESPITE A DECENT AMT
OF MOISTURE POOLING AHEAD OF FRONT...UPPER LVL SHORTWAVE AND ASSOC
LG SCALE FORCING IS LIFTING NORTH OF THE BORDER...SO EXPECT LINE
OF SHOWERS TO CONTINUE DISSIPATING AS IT PUSHES THRU THE EASTERN
COUNTIES BTWN 01Z-03Z. LATEST RAP OUTPUT INDICATES CDFRONT WILL
CLEAR THE EASTERNMOST COUNTIES /SCHUYLKILL AND LANCASTER/ BY
MIDNIGHT. BEHIND FRONT...ONLY CHC OF PRECIP WILL BE FROM LAKE
EFFECT BAND AFFECTING THE NW MTNS. CURRENT RADAR TRENDS AND
RAP/NAM OUTPUT SUGGEST A GOOD CHC OF SHOWERS ACROSS NW WARREN
COUNTY BTWN 01Z-06Z...AFTER WHICH BACKING BLYR FLOW SHOULD SHIFT
BAND NORTH OF THE BORDER.
CLEARING SHOULD TAKE PLACE OVER THE DOWNSLOPE AREAS OF THE CWA IN
THE POST-FRONTAL FLOW. THE INITIALLY GUSTY WEST WINDS SHOULD
SLACKEN LATE TONIGHT AS HIGH PRES RIDGE BUILDS IN FROM THE OHIO
VALLEY. BLEND OF LATEST LAMP AND RAP GUIDANCE SUGGEST TEMPS WILL
BOTTOM OUT IN THE M30S ACROSS THE ALLEGHENY PLATEAU...TO THE L40S
OVR THE SUSQ VALLEY.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE WILL PASS JUST SOUTH OF THE STATE ON SUNDAY...PROVIDING
THE AREA WITH SEASONABLY COOL AND DRY WX. ALTHOUGH A WSW BLYR FLOW
WILL KEEP LINGERING LAKE EFFECT ACTIVITY NORTH OF THE
BORDER...COLD TEMPS ALOFT SHOULD YIELD A GOOD AMT OF DIURNAL
STRATOCU ACROSS THE NW MTNS. WIND WILL INCREASE A BIT FROM A MORNING
LULL...AS THE ATMOS MIXES. MDL SOUNDINGS SUPPORT AFTN GUSTS BTWN
20-25KTS ACROSS THE NW MTNS...AND BTWN 10-15KTS ACROSS THE LOWER
SUSQ VALLEY.
HIGH TEMPS UNDER THE RATHER HOMOGENEOUS 0C-M2C 8H TEMPS WILL BE
ALMOST ENTIRELY DEPENDENT ON ELEVATION AND DOWNSLOPE WARMING.
MAXES SHOULD BE CLOSE TO 50F IN THE NW MTNS AND NEAR 60F IN THE
VALLEYS/LOWER ELEVS OF THE SUSQ VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
CENTRAL PA WILL BE ON NORTHERN EDGE OF ERODING HIGH PRESSURE RIDGE
SUN NIGHT INTO MON...WITH A WARM FRONT LIFTING THROUGH OHIO VALLEY
AND SKIRTING W PA. THIS WILL KEEP WEATHER FAIR AND MILD...WITH
HIGHS MONDAY SLIPPING INTO THE 60S /ABOUT 4-8F ABOVE NORMAL/.
THINGS START TO GO DOWNHILL MONDAY NIGHT AS NEW ENERGY STARTS
DIVING OUT OF SOUTHERN CANADA ON THE WAY TO CARVING OUT A LARGE
SCALE PERSISTENT TROF OVER THE EASTERN U.S. A BUILDING RIDGE OVER
THE WEST COAST WILL HELP DEEPEN AN ADVANCING LOW...WHICH WILL
DELIVER A STEADY FEED OF INCREASINGLY MORE CHILLY AIR ACROSS THE
UPPER MIDWEST NEXT WEEK. THIS COLD AIR WILL PROPAGATE INTO THE
LOWER LAKES AND LOCAL AREA IN THE WAKE OF A COLD FRONTAL BOUNDARY
PROGGED FOR TUESDAY...AND REINFORCED BY SECONDARY TROUGH ON
WEDNESDAY /AS ANOTHER LOW FORMS ALONG THE BOUNDARY AND SLIDES
ACROSS MID ATLANTIC STATES JUST TO OUR SOUTH BEFORE SLIDING OFF
THE COAST OF NEW ENGLAND/.
SOME DIFFERENCES CONTINUE IN MODEL SOLUTIONS STARTING AROUND
WEDNESDAY WHEN THE ECMWF BRINGS A STRONG SHORTWAVE OUT OF THE
OHIO VALLEY. THE OPERATIONAL GFS AND THE GEFS /PREVIOUSLY WITH A
FLATTER TROUGH/ ARE COMING MORE IN LINE WITH THE EC...WHICH WILL
INCREASE OUR POP CHANCES FOR WED WITH A STEADY LIGHT RAIN POSS.
AFTER THAT...CYCLONIC FLOW WILL CONTINUE TO ALLOW INCREASINGLY
COOLER AIR TO FILTER IN ON NW FLOW. PLENTY OF COLD ADVECTION
STRATOCU AND LAKE/OROGRAPHIC SHOWERS LOOKING LIKELY IN THE HIGHER
WESTERN TERRAIN MID/LATE WEEK...WITH DOWNSLOPE COMPONENT TO WINDS
KEEPING PRECIP AT A MIN FOR THE SE. LOW LEVEL TEMPS GET COLD
ENOUGH /850MB TEMPS DIP BELOW 0C/ THAT LIGHT SHOWERS COULD BE
MIXED WITH WET SNOW DURING THE CHILLIEST PART OF THE DAY AND
OVERNIGHT.
HIGH PRESSURE BUILDS IN LOW LEVELS FOR THE WEEKEND...BRINGING
QUITE CHILLY MORNING TEMPS. BUT AN OVERALL MORE SETTLED WEATHER
PATTERN. REINFORCING SHOT OF COLDER AIR POSS EARLY NEXT WEEK.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
COLD FRONT EVIDENT ON RADAR THIS EVENING...EXTENDING FROM ABOUT
KBFD TO KJST AT 00Z. FRONT WILL SWEEP THROUGH CENTRAL AIRFIELDS
DURING THE NEXT 3 HOURS OR SO. EXPECT A BAND OF MVFR TO ISOLATED
IFR CIGS TO ACCOMPANY THE FRONT. PRECIPITATION SHOULD END RAPIDLY
AFTER FROPA...WITH IMPROVING CIGS. DO EXPECT MVFR CIGS TO PERSIST
IN KBFD AND KJST WELL AFTER MIDNIGHT...WITH MOIST UPSLOPE WESTERLY
FLOW.
ON SUNDAY...HIGH PRESSURE BUILDS IN WEST OF THE AREA FROM THE
TENNESSEE VALLEY...BUT STAYS FAR ENOUGH AWAY TO KEEP SOME GRADIENT
WIND...GENERALLY 10 TO 15 KTS...DURING THE DAY. OTHERWISE...AFTER
SOME LINGERING LOWER CIGS EARLY AT KBFD AND KJST...VFR CONDITIONS
EXPECTED SUNDAY.
MONDAY LOOKS FAIR/VFR AS HIGH PRESSURE SLIDES TO THE EAST COAST
AND RETURN FLOW BEGINS. MORE COLD AIR ARRIVES WITH THE NEXT COLD
FRONT MON NIGHT AND TUESDAY.
OUTLOOK...
TUE...FROPA. MVFR/IFR POSS DUE TO SHOWERS/CLOUDS...ESP NW.
WED...MVFR POSS IN SHRA...ESP NW.
THURS...BREEZY...MVFR CLOUDS/SHRA N/W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO/FITZGERALD
LONG TERM...RXR
AVIATION...JUNG
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
826 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION THIS EVENING FOLLOWED
BY A VISIT FROM HIGH PRESSURE ON SUNDAY AND MONDAY. THE PATTERN
WILL TURN NOTICEABLY COOLER AND UNSETTLED NEXT WEEK AS AN UPPER
TROUGH ESTABLISHES ITSELF OVER THE EASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
EARLY EVENING REGIONAL RADAR LOOP SHOWING WIDESPREAD SHOWERS
FALLING ACROSS MOST OF CENTRAL PA...ALONG AXIS OF SOUTHERLY LL
JET/HIGHEST PWATS AHEAD OF APPROACHING COLD FRONT. FINE LINE OF
HIGHER RETURNS ALONG COLD FRONT NOTED ON THE OH/PA BORDER. AS CD
FRONT SWEEPS EAST...WOULDN/T BE SURPRISED TO SEE A COUPLE
LIGHTNING STRIKES ACROSS NORTH CENTRAL PA...WHERE NR TERM MDLS
PLACE SOME MARGINAL INSTABILITY.
LATEST RAP OUTPUT TIMES CDFRONT INTO THE W MTNS ARND 01Z AND
CLEARING THE EASTERNMOST COUNTIES /SCHUYLKILL AND LANCASTER/ BY
MIDNIGHT. WESTERLY FLOW OF MUCH DRIER AIR BEHIND THE FRONT WILL
SHUT OFF RAINFALL OVER NEARLY ALL OF THE AREA LATER THIS
EVENING...WITH THE POSSIBLE EXCEPTION OF THE NW MTNS...WHERE LAKE
EFFECT -SHRA COULD LINGER BEHIND FRONT. A MID-LAKE BAND WILL
PROBABLY DEVELOP ON GOOD INSTABILITY UNDER THE COLD AIR...AND WRLY
FLOW WILL MAKE IT JUST BRUSH AREAS N OF ROUTE 6 TONIGHT AND INTO
SUN MORNING.
CLEARING SHOULD TAKE PLACE OVER THE DOWNSLOPE AREAS OF THE CWA IN
THE POST-FRONTAL FLOW. THE INITIALLY GUSTY WEST WINDS WILL STAY UP
FOR MUCH OF THE NIGHT...BUT COULD SLACKEN IN THE DEEPER VALLEYS.
WILL LEAVE OUT MENTIONS OF VALLEY FOG AT THIS POINT WITH DEWPOINTS
FALLING INTO THE 30S AND WIND STILL GOING ALL NIGHT. BUT IT IS
TOUGH TO KEEP IT FROM FORMING WHEN AIR TEMP IS IN THE 30S AND
WATER MUCH WARMER.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE TO THE SOUTH OF THE STATE LOOKS VERY SIMILAR TO WHAT
THE PATTERN WAS ON FRIDAY. BUT...MUCH LESS MOISTURE AROUND...SO
THIS SHOULD LEAD TO MORE SUNSHINE. DIURNAL CU IS LIKELY OVER THE
HIGHER ELEVATIONS OF THE ALLEGHENIES...BUT COVERAGE SHOULD BE SCT
AT WORST. THE CLOUDS AND ANY SPRINKLES IN THE FAR NRN TIER SHOULD
LIFT TO THE NORTH THROUGH THE MORNING AND LEAVE A FAIR DAY THERE
AS WELL. WIND WILL INCREASE A BIT FROM ANY MORNING LULL AS THE
ATMOS MIXES. MAXES UNDER THE RATHER HOMOGENEOUS 0C-M2C 8H TEMPS
WILL BE ALMOST ENTIRELY DEPENDENT ON ELEVATION AND DOWNSLOPE
WARMING. THUS...MAXES CLOSE TO 50F IN THE NW MTS AND NEAR 60F IN
THE VALLEYS/LOWER ELEVS OF THE SUSQ VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
CENTRAL PA WILL BE ON NORTHERN EDGE OF ERODING HIGH PRESSURE RIDGE
SUN NIGHT INTO MON...WITH A WARM FRONT LIFTING THROUGH OHIO VALLEY
AND SKIRTING W PA. THIS WILL KEEP WEATHER FAIR AND MILD...WITH
HIGHS MONDAY SLIPPING INTO THE 60S /ABOUT 4-8F ABOVE NORMAL/.
THINGS START TO GO DOWNHILL MONDAY NIGHT AS NEW ENERGY STARTS
DIVING OUT OF SOUTHERN CANADA ON THE WAY TO CARVING OUT A LARGE
SCALE PERSISTENT TROF OVER THE EASTERN U.S. A BUILDING RIDGE OVER
THE WEST COAST WILL HELP DEEPEN AN ADVANCING LOW...WHICH WILL
DELIVER A STEADY FEED OF INCREASINGLY MORE CHILLY AIR ACROSS THE
UPPER MIDWEST NEXT WEEK. THIS COLD AIR WILL PROPAGATE INTO THE
LOWER LAKES AND LOCAL AREA IN THE WAKE OF A COLD FRONTAL BOUNDARY
PROGGED FOR TUESDAY...AND REINFORCED BY SECONDARY TROUGH ON
WEDNESDAY /AS ANOTHER LOW FORMS ALONG THE BOUNDARY AND SLIDES
ACROSS MID ATLANTIC STATES JUST TO OUR SOUTH BEFORE SLIDING OFF
THE COAST OF NEW ENGLAND/.
SOME DIFFERENCES CONTINUE IN MODEL SOLUTIONS STARTING AROUND
WEDNESDAY WHEN THE ECMWF BRINGS A STRONG SHORTWAVE OUT OF THE
OHIO VALLEY. THE OPERATIONAL GFS AND THE GEFS /PREVIOUSLY WITH A
FLATTER TROUGH/ ARE COMING MORE IN LINE WITH THE EC...WHICH WILL
INCREASE OUR POP CHANCES FOR WED WITH A STEADY LIGHT RAIN POSS.
AFTER THAT...CYCLONIC FLOW WILL CONTINUE TO ALLOW INCREASINGLY
COOLER AIR TO FILTER IN ON NW FLOW. PLENTY OF COLD ADVECTION
STRATOCU AND LAKE/OROGRAPHIC SHOWERS LOOKING LIKELY IN THE HIGHER
WESTERN TERRAIN MID/LATE WEEK...WITH DOWNSLOPE COMPONENT TO WINDS
KEEPING PRECIP AT A MIN FOR THE SE. LOW LEVEL TEMPS GET COLD
ENOUGH /850MB TEMPS DIP BELOW 0C/ THAT LIGHT SHOWERS COULD BE
MIXED WITH WET SNOW DURING THE CHILLIEST PART OF THE DAY AND
OVERNIGHT.
HIGH PRESSURE BUILDS IN LOW LEVELS FOR THE WEEKEND...BRINGING
QUITE CHILLY MORNING TEMPS. BUT AN OVERALL MORE SETTLED WEATHER
PATTERN. REINFORCING SHOT OF COLDER AIR POSS EARLY NEXT WEEK.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
COLD FRONT EVIDENT ON RADAR THIS EVENING...EXTENDING FROM ABOUT
KBFD TO KJST AT 00Z. FRONT WILL SWEEP THROUGH CENTRAL AIRFIELDS
DURING THE NEXT 3 HOURS OR SO. EXPECT A BAND OF MVFR TO ISOLATED
IFR CIGS TO ACCOMPANY THE FRONT. PRECIPITATION SHOULD END RAPIDLY
AFTER FROPA...WITH IMPROVING CIGS. DO EXPECT MVFR CIGS TO PERSIST
IN KBFD AND KJST WELL AFTER MIDNIGHT...WITH MOIST UPSLOPE WESTERLY
FLOW.
ON SUNDAY...HIGH PRESSURE BUILDS IN WEST OF THE AREA FROM THE
TENNESSEE VALLEY...BUT STAYS FAR ENOUGH AWAY TO KEEP SOME GRADIENT
WIND...GENERALLY 10 TO 15 KTS...DURING THE DAY. OTHERWISE...AFTER
SOME LINGERING LOWER CIGS EARLY AT KBFD AND KJST...VFR CONDITIONS
EXPECTED SUNDAY.
MONDAY LOOKS FAIR/VFR AS HIGH PRESSURE SLIDES TO THE EAST COAST
AND RETURN FLOW BEGINS. MORE COLD AIR ARRIVES WITH THE NEXT COLD
FRONT MON NIGHT AND TUESDAY.
OUTLOOK...
TUE...FROPA. MVFR/IFR POSS DUE TO SHOWERS/CLOUDS...ESP NW.
WED...MVFR POSS IN SHRA...ESP NW.
THURS...BREEZY...MVFR CLOUDS/SHRA N/W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...DANGELO/FITZGERALD
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...JUNG
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1127 AM EDT FRI OCT 18 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD IN THIS AFTERNOON.
HOWEVER...THE FAIR WEATHER WILL BE SHORT-LIVED AS THE WEATHER
PATTERN WILL BE UNSETTLED OVER THE NEXT WEEK AS A SERIES OF FRONTS
MOVE THROUGH THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
CLOUDS ARE DISSIPATING AND SLIDING ENE. RH PROGS DO INDICATE A
GRADUAL DRYING...AND HAVE FOLLOWED RUC SKY FOR THE NEXT 12 HRS.
MID-LAKE BAND SHOULD REMAIN JUST TO THE NORTH OF THE NY BORDER.
SFC HIGH TO THE SOUTH WILL EAT AWAY AT THE CLOUDS. BUT UPSLOPE
FLOW COMPONENT AND PROXIMITY TO THE HIGH AND RELATED SUBSIDENCE
WILL DICTATE THE DEGREE AND RAPIDITY OF CLEARING.
WELL MIXED MDL SOUNDINGS ARE SUPPORTIVE OF WEST WINDS BTWN
10-20KTS...BUT THESE SHOULD GET A LITTLE LIGHTER ON THE WHOLE
DURING THE LATE AFTN. TEMPS STILL EXPECTED TO TOP OUT IN THE
M50S-M60S...PRETTY CLOSE TO NORMAL FOR MID OCT.
THE OVERNIGHT WILL BE FAIR AND DRY WITH JUST A FEW HIGH CLOUDS
STARTING TO INVADE THE NW TOWARD MORNING. IT WILL NOT BE
PARTICULARLY COLD...WITH LOWS IN THE 40S BEING NEAR OR EVEN
SLIGHTLY WARMER THAN NORMAL.
&&
.SHORT TERM /SATURDAY/...
A NEW COLD FRONT WILL APPROACH THE REGION SATURDAY SPREADING
MORE SHOWERS OUR WAY...ESPECIALLY LATER IN THE MORNING INTO THE
AFTERNOON. THE ATMOSPHERE WILL NOT HAVE MUCH TIME TO RECOVER SO
THE FRONT WILL NOT HAVE A GREAT DEAL OF MOISTURE TO WORK WITH.
MARGINALLY STEEP MID LEVEL LAPSE RATES SHOULD PROVIDE JUST ENOUGH
INSTABILITY TO GIVE MOST AREAS SOME LIGHT SHOWERS. ENSEMBLE QPF
SHOWS AMOUNTS GENERALLY .10" OR LESS WITH THE NW HAVING A LOW
PROBABILITY OF AS MUCH AS .25" IN SOME SPOTS.
THE MAIN THING TO BE SAID OF THE NEXT COLD FRONT IS THAT WILL BE
THE HARBINGER OF A COOLER MORE UNSETTLED PATTERN SETTING UP FOR
THE NEXT WEEK OR SO.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A SIGNIFICANT PATTERN CHANGE IS IN STORE FOR THE REGION DURING THE
EXTENDED PERIOD WITH MUCH OF THE EAST COAST COMING UNDER THE
INFLUENCE OF AN ANOMALOUSLY DEEP UPPER TROUGH THAT WILL MOVE OUR
WAY OUT OF THE GR LAKES. A STRONG TYPHOON THAT PASSED EAST OF
JAPAN SEVERAL DAYS AGO IS NOW BEING ABSORBED INTO THE FLOW OVER
THE NORTHERN PACIFIC...HELPING PUMP UP THE WESTERN NORTH AMERICAN
RIDGE. THIS WILL HELP DELIVER INCREASINGLY CHILLY AIR DOWN INTO
FIRST THE UPPER MID WEST AND EVENTUALLY INTO THE LOWER LAKES AND
LOCAL AREA BY THE TUESDAY-WEDNESDAY TIMEFRAME.
PRECIP CHANCES WILL BE MANY...BUT MAINLY FROM MOISTURE-STARVED
CLIPPER TYPE SYSTEMS. TIMING WITH THESE ALWAYS PRESENTS A
PROBLEM...BUT WITH THE COLD AIR EXPECTED TO MOVE OUR WAY...ANY
LIGHT SHOWERS THAT FALL DURING THE COLD PART OF THE DAY COULD
ACTUALLY MIX WITH SOME WET SNOW. AN EARLY SEASON REMINDER OF WHAT
IS IN STORE.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
ONE THICKER/LONGER BAND OF CLOUDS ALONG THE MIDDLE OF THE LAKE AND
NOW SLIDING TO THE NORTH. CLOUD BASES NOT LIFTING ALL THAT MUCH
WITH STRONG COLD ADVECTION AND ONLY BALANCED SFC HEATING. OVERALL
AREA/COVERAGE OF CLOUDS IS ON THE DECREASE THOUGH. EXPECT VFR FOR
UNV - AND PERHAPS JST AS THEY LOSE THEIR THICKEST CLOUD COVER.
DIURNAL CU IS POPPING TO PARTIALLY REPLACE THE STRATUS THOUGH.
SHOULD STAY BREEZY THROUGH THE DAY WITH THE SFC HIGH TO OUR SOUTH
AND WESTERLIES JUST AS CLOSE.
ANOTHER COLD FRONT WILL BRING A CHANCE OF SHOWERS TO THE AREA ON
SATURDAY INTO SUNDAY MORNING. GUSTY WINDS AND LAKE EFFECT CLOUDS
WILL BE LIKELY EARLY SUNDAY...BULK OF THE SHOWERS WILL BE NORTH OF
OUR AREA...PERHAPS AN ISSUE FOR MAINLY N PA...SPOTS LIKE BFD
EARLY.
THE NEXT COLD FRONT MOVES IN LATE MONDAY INTO TUE. THIS AIRMASS
WILL BE COLDER AND DEEPER...THUS MORE OF THE WAY OF LAKE EFFECT
CLOUDS AND SHOWERS WILL PERSIST INTO MID WEEK.
OUTLOOK...
SAT...BECOMING CLOUDY WITH SHOWERS...MVFR AND POCKETS OF IFR.
SUN...MVFR CIGS/CHC OF LK EFFECT RAIN SHOWERS MAINLY NW. VFR
ELSEWHERE.
MON...NO SIG WX. TUE...FROPA. MVFR/IFR POSS DUE TO
SHOWERS/CLOUDS...ESP NW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...DANGELO
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...DANGELO/MARTIN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
345 PM CDT FRI OCT 18 2013
.DISCUSSION...
WIDESPREAD SHOWERS WITH ISOLATED THUNDER HAVE BEEN GOING ON OVER
THE WATERS TODAY. ISOLATED TO SCATTERED COVERAGE HAS BEEN OBSERVED
ALONG THE COASTAL COUNTIES. THIS IS ALL IN THANKS TO WIDESPREAD
ISENTROPIC LIFT. THE 850MB MOISTURE AXIS HAS CONTINUED TO PUSH TO
THE NORTHEAST FROM THE SOUTHWEST THIS AFTERNOON ALLOWING FOR MORE
OF THE RAIN TO REACH THE GROUND THIS AFTERNOON. INSTABILITY
REMAINS LIMITED THOUGH SO THUNDER LOOKS TO BE ISOLATED. A SOUNDING
FROM KCLL AT 15Z SHOWS A SATURATED LAYER JUST ABOVE 800MB TO ABOUT
600MB. INSTABILITY IS LIMITED. LOW LEVEL DRY AIR SHOULD START TO
ERODE AS THE THE WARM FRONT LIFTS NORTHWARDS.
COMPARING A 250MB HAND ANALYSIS FROM THIS MORNING THE ECMWF SEEMS
TO HAVE THE POSITION OF THE JET BEST. BOTH MODELS ARE CLOSE
THOUGH. EITHER WAY SOUTHEAST TEXAS IS IN THE RRQ OR DIVERGENT
REGION OF THE JET STREAK. THIS IN COMBINATION WITH A COLD FRONT
WILL HELP PROVIDE THE LIFTING MECHANISMS FOR RAIN THROUGH THE
EVENING HOURS. THE TEXAS TECH WRF HAS PRECIP LIMITED WITH THE
FRONT WHILE THE HRRR HAS WIDESPREAD RAIN AHEAD OF THE FRONT. BOTH
MODELS SEEMED TO HAVE INITIALIZED WELL. GIVEN SPOTTY COVERAGE NOW
HAVE LEANED TOWARDS THE WETTER SOLUTION. WAS A BIT HESITANT THOUGH
GIVEN WIDESPREAD CONVECTION ONGOING OVER WATERS. THIS COULD HINDER
THE DEVELOPMENT INLAND. BEHIND THIS FRONT BOTH ECMWF AND GFS
POSITION THE SURFACE HIGH PRESSURE OVER CENTRAL TEXAS SUNDAY
MORNING. THIS WILL ALLOW TEMPERATURES TO DROP INTO THE 40S FOR
MOST INLAND LOCATIONS.
THIS FRONT WILL AGAIN BE SHORT LIVED THOUGH AS IT BEGINS TO PULL
NORTHWARDS ON MONDAY. A SIMILAR SET UP TO THIS EVENING WILL AGAIN
BE ON TAP MONDAY NIGHT INTO TUESDAY. THE GFS AND ECMWF APPEAR TO
BE IN AGREEMENT WITH THE BEST UPPER LEVEL DIVERGENCE TO BE OFF THE
COAST AND THEN MOVING INTO LA. BEHIND THIS FRONT A SURFACE HIGH
PRESSURE WILL MOVE DOWN ALLOWING FOR PLEASANT CONDITIONS BEHIND
THE FRONT. THE GFS AND ECMWF HAVE THE BULK OF THE HIGH PRESSURE
MOVING OFF TOWARDS THE EAST IN ASSOCIATION WITH THE LONG WAVE
TROUGH. THIS SHOULD STILL ALLOW FOR NICE CONDITIONS TO CONTINUE
THOUGH THE REMAINDER OF THE WORK WEEK. 23
&&
.MARINE...
DIFFICULT MARINE FORECAST THIS AFTERNOON...AND MARINERS ARE URGED
TO CLOSELY MONITOR THE WEATHER AND WEATHER FORECASTS OVER THE NEXT
SEVERAL DAYS FOR POSSIBLE CHANGES. WINDS THAT HAVE BEEN AT CAUTION
LEVELS OFF THE COAST FOR SEVERAL HOURS NOW SHOULD COME DOWN LATER
THIS AFTERNOON AND THIS EVENING AS THE NEXT COLD FRONT APPROACHES
THE AREA. AFTER THE FRONTAL PASSAGE LATE TONIGHT THROUGH EARLY
TOMORROW MORNING...WINDS ARE EXPECTED TO STRENGTHEN AGAIN TO CAUTION
LEVELS FOR THE BAYS AND CLOSE TO ADVISORY LEVELS OFF THE COAST.
INSTEAD OF CARRYING FLAGS THIS AFTERNOON THEN LOWERING THEM THIS
EVENING THEN RAISING THEM AGAIN BEFORE SUNRISE...DECIDED TO JUST
KEEP FLAGS UP THROUGH TOMORROW AS THIS STORM SYSTEM AND ASSOCIATED
SHOWERS AND THUNDERSTORMS MOVE ON THROUGH. WINDS AND SEAS SHOULD
COME DOWN LATE SATURDAY AFTERNOON AND ON INTO SATURDAY NIGHT...THEN
PICK UP AGAIN ON MONDAY NIGHT AND TUESDAY AFTER THE PASSAGE OF THE
NEXT STORM SYSTEM AND COLD FRONT. ELEVATED WINDS AND SEAS EXPECTED
TO THEN PERSIST INTO THE MIDDLE OF THE WEEK SHOULD COME DOWN DURING
THE SECOND HALF OF THE WEEK AS HIGH PRESSURE BUILDS INTO THE AREA
AND THE GRADIENT RELAXES. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 53 69 47 75 58 / 60 20 10 0 20
HOUSTON (IAH) 59 73 50 78 60 / 60 30 10 0 20
GALVESTON (GLS) 68 75 62 76 68 / 70 50 10 10 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION FROM LATE TONIGHT THROUGH
SATURDAY AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY FROM 4 AM TO 6 PM CDT SATURDAY FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH LATE TONIGHT FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1134 PM CDT THU OCT 17 2013
.AVIATION...
EXPECT RAPIDLY DETERIORATING CONDITIONS AT LBB SHORTLY AFTER
MIDNIGHT AS LOW CIGS AND EVENTUALLY SOME DENSE FOG EMERGE IN A
VERY MOIST UPSLOPE REGIME. HAVE ALREADY NOTICED FEW CLOUDS AROUND
1500 FT AT LBB WITH LIGHT FOG REPORTED AT PVW. SATELLITE SHOWS A
DENSE LAYER OF MVFR AND IFR CIGS NEAR MIDLAND THAT WILL EXPAND
NORTH THROUGH THE NIGHT...SO OVERALL THIS PATTERN FAVORS IFR/LIFR
CIGS WITH OCCASIONAL DENSE FOG AND DRIZZLE ON THE CAPROCK. CDS
WILL FARE COMPARABLY BETTER WITH PREDOMINANTLY MVFR CIGS FOR THE
BETTER PART OF THE DAY.
WE STILL EXPECT VFR CONDS TO RETURN TO LBB AROUND 18Z OR SO ONCE
MOIST SOUTH WINDS VEER WESTERLY AHEAD OF A COLD FRONT. BUMPED
FROPA TIME BACK A TOUCH AT BOTH LBB AND CDS...BUT STILL KEPT NLY
GUSTS AROUND 30 KNOTS FOR MID-TO-LATE AFTERNOON. OUTSIDE OF A
STRAY SHRA BEHIND THE FRONT NEAR CDS...PRECIP WILL BE LIMITED.
&&
.PREV DISCUSSION... /ISSUED 932 PM CDT THU OCT 17 2013/
UPDATE...
UPDATED TO BOOST LOW CLOUD COVERAGE AFTER MIDNIGHT AND ALSO TO ADD
MENTION OF FOG AND DRIZZLE ON THE CAPROCK EARLY FRI MORNING. THE
02Z SURFACE PATTERN PAINTS A PRETTY CLASSIC PICTURE FOR SUCH A
SCENARIO LATER TONIGHT AS DEWPOINTS IN THE PERMIAN BASIN ARE
ALREADY PUSHING 60 DEGREES WITH TEMPS ON THE SOUTH PLAINS IN THE
MID AND UPPER 50S. LATEST NAM AND RECENT RUNS OF THE RAP ARE
CONSISTENT IN BREAKING OUT STRATUS AROUND 09Z ACROSS MUCH OF THE
CAPROCK AND WESTERN PERMIAN BASIN...A BIT SIMILAR TO WHAT WE SAW
LAST NIGHT IN SERN NEW MEXICO. MODEL SOUNDINGS SHOW SUFFICIENTLY
THICK STRATUS HERE FOR DRIZZLE BY 12Z AND THIS IS REFLECTED BY THE
NAM`S SPOTTY LIGHT QPF. DENSE FOG POTENTIAL IS A BIT LESS
CERTAIN...BUT THIS WILL BE REVISITED BY THE MIDNIGHT SHIFT.
ALSO REMOVED SHOWER MENTION ON THE CAPROCK FROM 12-17Z FRI AS
DRIZZLE WOULD BE THE MOST WE CAN SQUEEZE OUT BEFORE THE COLD FRONT
AND A BRIEF WINDOW FOR SHOWERS DEVELOP EARLY IN THE AFTERNOON JUST
BEHIND THE FRONT. GIVEN MILD LOWS AND MOIST ADVECTION...RAISED
OVERNIGHT LOWS SEVERAL DEGREES ON THE CAPROCK WHILE KEEPING AREAS
FARTHER EAST INTACT IN LIGHT OF DRIER AIR CHARACTERIZED BY
DEWPOINTS IN THE LOW/MID 40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 38 55 28 64 39 / 10 10 0 0 0
TULIA 47 53 32 65 41 / 10 20 10 0 0
PLAINVIEW 48 57 32 65 41 / 10 20 10 0 0
LEVELLAND 49 61 33 66 41 / 10 10 10 0 0
LUBBOCK 50 58 34 65 42 / 10 20 10 0 0
DENVER CITY 51 64 35 65 43 / 0 10 10 10 0
BROWNFIELD 52 63 35 65 43 / 10 10 10 0 0
CHILDRESS 51 56 36 69 44 / 20 30 20 0 0
SPUR 50 63 37 67 44 / 10 20 20 10 0
ASPERMONT 51 66 38 67 45 / 10 30 20 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
331 AM MDT SUN OCT 20 2013
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 331 AM MDT SUN OCT 20 2013
A FAST MOVING SHORTWAVE IN THE NORTHWESTERLIES WILL IMPACT THE
NORTHERN AND PORTIONS OF THE CENTRAL MOUNTAINS TODAY. HIGH
CLOUDS AHEAD OF THE SYSTEM BEGAN SWEEPING OVER THE NORTH LAST
EVENING. EXPECT SHOWERS WILL HOLD OFF UNTIL AFTER 12Z PER
CONSENSUS OF GFS40...NAM12...RAP13...AND HRRR MODELS. THEREFORE
...PARED BACK POPS EARLY THIS MORNING.
AS THE SHORTWAVE SWEEPS SOUTHEASTWARD ACROSS SOUTHWEST WYOMING
SHOWERS WILL DEVELOP OVER THE ELKHEADS AROUND SUNRISE. THIS
ACTIVITY WILL SPREAD TO THE PARK AND GORE RANGES...FLAT TOPS...AND
ELK MOUNTAINS AS THE AXIS OF THE SHORTWAVE SWEEPS INTO NORTHWEST
COLORADO THIS AFTERNOON. UPWARD FORCING...OROGRAPHIC LIFT AND
SUFFICIENTLY STEEP LAPSE RATES WILL BRING ACCUMULATING SNOW TO
THE NORTHERN AND CENTRAL MOUNTAINS. SNOW LEVELS WILL SETTLE AROUND
MOUNTAIN BASES IN THE NORTH AND NEAR 8500 FEET IN THE CENTRAL
MOUNTAINS THIS AFTERNOON. MOISTURE LACKING WITH THIS SYSTEM SO
WILL CONTINUE WITH 1 TO 2 INCH ACCUMULATIONS IN THE MOUNTAIN AREAS
MENTIONED PREVIOUSLY. LOWER ELEVATIONS EAST OF KCAG-KASE LINE
COULD SEE BRIEF SHOWERS BUT CHANCES NOT GREAT GIVEN LIMITED
MOISTURE.
ELSEWHERE...EXPECT DRY WEATHER TO CONTINUE WITH PARTLY SUNNY TO
MOSTLY SUNNY SKIES AND HIGHS CONTINUING TO RUN A BIT COOL FOR THIS
TIME OF YEAR. A PUSH OF COOLER AIR COMBINED WITH CLOUDS AND
SHOWERS WILL DECREASE TEMPERATURES AROUND 5 DEGREES ACROSS NORTH-
CENTRAL COLORADO THIS AFTERNOON.
SNOW GRADUALLY TAPERS OFF OVERNIGHT FROM THE NORTH AS THE BULK OF
PRECIPITATION HANGS OVER THE DIVIDE THROUGH THE MORNING HOURS
MONDAY WITH FAVORABLE WIND DIRECTION FOR LINGERING LIGHT SNOW
STRETCHING ALONG THE CENTRAL MOUNTAIN CORRIDOR. SNOW LEVEL WILL
DECREASE TO AROUND 6500 FEET BY EARLY MONDAY MORNING WITH THE
ADVECTION OF COLD NORTHERLY AIR. 1 TO 3 INCHES OF SNOW IS EXPECTED
OVER THE NORTHERN MOUNTAINS AND PORTIONS OF THE CENTRAL MOUNTAINS
THROUGH EARLY MONDAY MORNING...WITH THE POTENTIAL FOR LOCALLY
HIGHER AMOUNTS. THE SHORTWAVE IS FORECAST TO PROGRESS TO THE VERY
EASTERN PART OF CENTRAL COLORADO BY NOON MONDAY...SO ALL
PRECIPITATION IS EXPECTED TO HAVE CEASED OVER THE DIVIDE WITH
BRISK NORTHERLY AIR FILTERING IN BEHIND IN AN AREA OF SUBSIDENCE.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 331 AM MDT SUN OCT 20 2013
CLEAR SKIES AND SLIGHTLY BELOW NORMAL TEMPERATURES WILL REIGN AS
HIGH PRESSURE BUILDS INTO THE REGION MONDAY NIGHT. WINDS WILL
REMAIN LIGHT...ALLOWING INVERSIONS TO DEVELOP IN VALLEY BOTTOMS
OVERNIGHT AND KEEP LOW TEMPERATURES BELOW NORMAL.
A WEAK MID-LEVEL LOW PRESSURE TROUGH OVER THE WEST COAST UNDERCUTS
THE RIDGE...MOVING EASTWARD ACROSS THE GREAT BASIN AND DESERT
SOUTHWEST TUESDAY NIGHT THROUGH THURSDAY. MODELS TAKE THE BULK OF
THE ENERGY ASSOCIATED WITH THIS FEATURE SOUTH OF THE FORECAST AREA
FROM THURSDAY NIGHT INTO FRIDAY BEFORE PUSHING IT ONTO THE
SOUTHERN PLAINS SATURDAY. LATEST ECMWF FARTHER SOUTH WITH THIS
FEATURE THAN YESTERDAY/S 00Z RUN WHICH LIMITS CHANCES FOR ANY
SENSIBLE WEATHER OVER THE SAN JUANS FRIDAY. LESS ENERGETIC GFS
SHOWED LITTLE CHANGE AND ALSO DRY FRIDAY. AS A RESULT...KEPT
MENTION OF PRECIPITATION CHANCES OUT OF THE FORECAST THROUGHOUT
THE ENTIRE EXTENDED PERIOD. EXPECT TEMPERATURES WILL HOVER NEAR
NORMAL THROUGH THE COMING WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 331 AM MDT SUN OCT 20 2013
A SOUTHEASTWARD PROPAGATING UPPER LEVEL DISTURBANCE WILL BRUSH
NORTH-CENTRAL COLORADO TODAY. SNOW WILL DEVELOP OVER THE ELKHEAD
MOUNTAINS THIS MORNING THEN SPREADS SOUTHEAST WHILE INCREASING IN
INTENSITY THIS AFTERNOON. AS A RESULT...EXPECT AREAS OF MOUNTAIN
OBSCURATION OVER THE ELKHEAD...PARK...AND PORTIONS OF THE PARK
RANGE THIS MORNING...BECOMING WIDESPREAD THIS AFTERNOON. THERE IS
A SLIGHT CHANCE THAT KCAG...KEEO...KHDN...KSBS...AND KEGE WILL
EXPERIENCE BRIEF MVFR CIGS IN LIGHT SHOWERS FROM 18Z TO 00Z.
ELSEWHERE...EXPECT VFR CONDITIONS TO PERSIST THROUGH THE NEXT 24
HOURS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...NL/JAM
LONG TERM...JAM/NL
AVIATION...NL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1219 AM CDT SUN OCT 20 2013
.DISCUSSION...
927 PM CDT
NO CHANGES TO CURRENT FROST ADVISORY.
LATEST SATELLITE/RADAR IMAGERY DEPICTING CLOUD COVER ISOLATED
LIGHT SHOWERS STILL ACROSS THE CWA...ASSOCIATED WITH UPPER LEVEL
WAVE/TROUGH AND SURFACE REFLECTION. ALTHOUGH LATEST RAP ANALYSIS
IS INDICATING SOME PERSISTENT WEAK WAA ACROSS NORTH CENTRAL
ILLINOIS...THIS SHOULD WEAKEN OVER THE NEXT SEVERAL HOURS AS
TROUGH DEPARTS TO THE EAST. CLEARING SKIES AND DIMINISHING WINDS
SHOULD ALLOW FOR TEMPS TO STILL DROP OVERNIGHT...WITH THIS ALREADY
BEING OBSERVED IN LOCATIONS THAT SAW SOME PARTIAL CLEARING EARLY
ON. SO HAVE MADE MINOR ADJUSTMENTS TO TEMPS TONIGHT WITH CURRENT
ADVISORY LOCATION STILL APPEARING TO BE ON TRACK. DESPITE THIS
BEING THE PREFERRED LOCATION FOR BETTER FROST DEVELOPMENT...PATCHY
FROST CANNOT BE RULED OUT BRIEFLY LATE TONIGHT INTO EARLY SUNDAY
MORNING FOR THE REMAINDER OF THE CWA. ALSO...LATEST DEWPOINT
TRENDS COINCIDING WITH TEMPS TONIGHT COULD ALLOW FOR PATCHY
FOG...AND HAVE ADDED TO THE GRIDS PRIMARILY FOR NORTHERN ILLINOIS.
RODRIGUEZ
//PREV DISCUSSION...
243 PM CDT
REST OF THE WEEKEND...TONIGHT THROUGH SUNDAY NIGHT...
WEATHER TO BE CONTROLLED BY THE LARGE UPPER TROUGH EXTENDING
ACROSS WESTERN HUDSON BAY SOUTHWARD TO THE OZARKS EARLY THIS
AFTERNOON MOVING TO EASTERN CANADA AND NEW ENGLAND OVERNIGHT AND
DURING SUNDAY. THIS WILL ALLOW WEAK UPPER RIDGING TO OCCUR OVER
THE GREAT LAKES AND MIDWEST SUNDAY AS THIS UPPER TROUGH ROTATES
NORTHEASTWARD AND ANOTHER UPPER TROUGH DEEPENS OVER THE UPPER
MIDWEST AND THE UPPER AND MID MS VALLEY DURING SUNDAY AND SUNDAY
NIGHT.
HAVE RETAINED MENTION OF FROST ACROSS ACROSS NORTH CENTRAL AND
NORTHEAST IL OUTSIDE OF THE METRO AREA THOUGH CONFIDENCE IS NOT
PARTICULARLY HIGH AS WARM AIR ADVECTION CLOUDS CONTINUE TO SPREAD
FROM IA ACROSS NORTHERN IL LATER THIS AFTERNOON AND TONIGHT
SHOULD BE ENOUGH BREAKS DURING THE OVERNIGHT FOR AREAS OF FROST.
A BACKING AND INCREASING LOW LEVEL FLOW DURING SUNDAY WILL ALLOW
SOME MODERATION IN TEMPERATURES AS SIGNIFICANT WARM AIR ADVECTION
OCCURS. WHILE CLOUDS ARE EXPECTED TO GRADUALLY BE ON THE INCREASE
DURING THE DAY THE WARM AIR ADVECTION ITSELF SHOULD PUSH SUNDAY
HIGH TEMPERATURES UP TO THE UPPER 50S NORTH TO MID 60S SOUTHWEST.
DESPITE THE INCREASING CLOUDINESS AS THE UPPER WAVE ROTATES
ACROSS FROM THE NORTHERN PLAINS TO OVER MN AND IA ANY REAL THREAT
OF RAIN WILL REMAIN NORTH OF THE WI BORDER WHERE THE BEST FORCING
WILL BE. AS THE UPPER TROUGH MOVES TO WESTERN WI AND NORTHWEST
AND WEST CENTRAL IL DURING SUNDAY NIGHT POPS WILL RISE TO SLIGHT
CHANCE AS THE UPPER TROUGH APPROACHES AND AN ASSOCIATED COLD
FRONT PUSHES SOUTHEASTWARD ACROSS THE LOCAL FORECAST AREA.
MONDAY THROUGH SATURDAY...
THE MODERATION IN TEMPERATURES WILL BE SHORT LIVED AS THE UPPER
FLOW STARTS TO RETURN TO STRONG NORTHWESTERLY ACROSS THE AREA BY
MONDAY NIGHT WITH A SERIES OF SHORT WAVES ROTATING THROUGH THE
UPPER TROUGH PROVIDING REINFORCING SHOTS OF VERY COOL AIR THROUGH
THE WEEK KEEPING HIGH TEMPERATURES DOWN TO MID 40S TO LOWER
50S...WITH LOWS FROM UPPER 20S TO MID 30S.
USING THE 12Z ECMWF AS A GOOD COMPROMISE BETWEEN MODEL SOLUTIONS
THE MAIN PERIODS FOR A THREAT OF PRECIPITATION ARE FROM LATER
TUESDAY INTO WEDNESDAY AS A SHORT WAVE APPROACHES AND MOVES
ACROSS THE AREA AND THEN NEXT SATURDAY AS AN UPPER TROUGH MOVES
EAST OVER THE UPPER MIDWEST AND THE MID AND LOWER MO VALLEY
REGIONS PUSHING ANOTHER COLD FRONT INTO THE LOCAL AREA DURING THE
DAY.
WITH THE TUESDAY-TUESDAY NIGHT SHORT WAVE TROUGH PASSAGE THE
COLUMN COOLS TO BELOW 0C ACROSS NORTH CENTRAL AND FAR NORTHEAST
IL DURING THURSDAY NIGHT SO ANY REMAINING RAIN MAY MIX WITH OR
CHANGE TO SNOW BEFORE ENDING.
WITH SEVERAL SHORT WAVES TO BE ROTATING THROUGH THE MEAN UPPER
TROUGH THERE COULD BE OTHER TIME-FRAMES WHEN THERE WOULD BE AT
LEAST A SLIGHT CHANCE TO LOW END CHANCE OF PRECIPITATION BUT
TIMING OF ANY ONE OF THESE SMALLER DISTURBANCES IS PRETTY MUCH
FUTILE THESE FEATURES TYPICALLY GET LOST IN THE NOISE OF THE
PROGS.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PERIOD OF STRONG SOUTH WINDS WITH GUSTS AROUND 25 KT THIS
AFTERNOON AND POSSIBLY INTO THIS EVE.
* SCATTERED -SHRA WITH POSSIBLE TEMPORARY MVFR CONDITIONS THIS
EVE.
* GUSTY WEST WINDS LATE SUNDAY NIGHT.
//DISCUSSION...UPDATED 06Z...
TEMPORARY RIDGING WILL PREVAIL THROUGH SUNRISE BEFORE SOUTHERLY
WINDS ENSUE. THESE WILL INCREASE IN SPEED THIS AFTERNOON AS STRONG
LOW PRESSURE DEVELOPS ACROSS THE UPPER MISSISSIPPI VALLEY. SOME
PERIODIC GUSTINESS MAY CONTINUE IN THE EVE. AS A STRONG COLD FRONT
WRAPS AROUND THIS LOW AND APPROACHES THE TAF SITES THIS
EVE...SCATTERED SHOWERS ARE ALSO POSSIBLE. IF THESE
MATERIALIZE...TEMPORARY MVFR CONDITIONS COULD EASILY ACCOMPANY
THEM. THE STRONG COLD FRONT WILL MOVE FROM WEST TO EAST ACROSS THE
TAF SITES SUNDAY NIGHT AND TURN THE WINDS WESTERLY WITH A RE-
INCREASE IN GUSTINESS. A BRIEF PERIOD OF MVFR CIGS ARE ALSO
POSSIBLE WITH THIS FEATURE.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN WINDS THIS AFTERNOON AND TONIGHT. HIGH CONFIDENCE THAT
WINDS WILL BE BETWEEN 160 AND 210 THIS AFTERNOON.
* LOW IN SHRA THIS EVE AND POSSIBLE MVFR CONDITIONS.
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...MVFR CIGS LIKELY.
TUESDAY...MVFR CIGS POSSIBLE. CHANCE OF -RA OR -RSSN.
WEDNESDAY...MVFR CIGS POSSIBLE...MAINLY EARLY.
THURSDAY AND FRIDAY...PROBABLY VFR.
MTF/IZZI
&&
.MARINE...
334 PM CDT
A VERY ACTIVE PERIOD ON THE WAY ACROSS THE LAKE AS A SERIES OF LOW
PRESSURE SYSTEMS AND A UNSEASONABLY COLD AIR MASS COMBINE TO BRING
STRONG WINDS MOST OF THE FORECAST PERIOD. WEST WINDS OVER THE SOUTH
HALF WILL RAMP UP TO 30 KT THIS EVENING BEFORE DIMINISHING SOME
LATE. THERE WILL BE A BRIEF PERIOD OF LIGHTER SOUTH WINDS SUNDAY
MORNING BEFORE LOW PRESSURE APPROACHES FROM THE WEST LATER SUNDAY
AND SOUTHERLY WINDS INCREASE.
SOME UNCERTAINTY EXISTS AS TO THE TRACK AND TIMING OF THE LOW...BUT
THERE IS GOOD AGREEMENT AMONGST GUIDANCE FOR SOUTH TO SOUTHWEST
WINDS UP TO GALE FORCE SOMETIME SUNDAY EVENING INTO THE OVERNIGHT
FOR THE CENTRAL AND SOUTHERN PORTION OF THE LAKE. THEREFORE HAVE
ISSUED A GALE WATCH FOR THE CENTRAL AND SOUTH STARTING AT 00Z
SUNDAY. A VERY STRONG COLD FRONT WILL SWEEP ACROSS THE LAKE AS THE
LOW LIFTS TO EASTERN LAKE SUPERIOR BY EARLY MONDAY AND DEEPENS.
SOUTHWEST GALES WILL QUICKLY TRANSITION TO WESTERLY GALES ON THE
CENTRAL AND SOUTH...WHILE WESTERLY GALES WILL DEVELOP OVER THE NORTH
TOWARD EARLY MONDAY MORNING. A WINTER LIKE AIRMASS WILL POUR ACROSS
THE LAKE...SUPPORTING EXTREMELY UNSTABLE CONDITIONS AND EFFICIENT
MIXING. WEST GALES WILL INCREASE TO 40 KT ON THE NORTH PART OF THE
LAKE ON MONDAY...WITH 35 KT CONTINUING TO THE SOUTH. THERE THEN
APPEARS TO BE ANOTHER COLD FRONT OR SECONDARY SURGE OF COLD AIR
MONDAY NIGHT EXPECTED TO KEEP GALES GOING ON THE NORTH ALL THE WAY
INTO TUESDAY MORNING. THUS HAVE EXTENDED THE GALE WATCH THERE UNTIL
15Z TUESDAY.
FOR THE NEARSHORE WATERS...HAVE EXTENDED THE SMALL CRAFT ADVISORY
FOR GARY AND POINTS EAST UNTIL 9Z SUNDAY AS WAVES WILL BE SLOWER TO
SUBSIDE. WILL THEN LIKELY NEED A SMALL CRAFT ADVISORY FOR ALL THE
NEARSHORE ZONES SOMETIME SUNDAY EVENING THROUGH MONDAY
EVENING...THEN AT LEAST A PORTION OF THE INDIANA NEARSHORE ALL THE
WAY THROUGH TUESDAY EVENING DUE TO WAVES.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FROST ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012 UNTIL 8 AM SUNDAY.
IN...NONE.
LM...GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 PM
SUNDAY TO 4 AM TUESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...3 AM
MONDAY TO 10 AM TUESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM SUNDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
512 AM EDT SUN OCT 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 510 AM EDT SUN OCT 20 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE OFF THE WEST COAST AND
A BROAD MID/UPPER LEVEL TROUGH ACROSS THE CNTRL AND ERN CONUS. ONE
UPSTREAM SHORTWAVE TROUGH WAS LOCATED OVER THE DAKOTAS WHILE ANOTHER
STRONGER PV ANOMALY WAS DROPPING TO THE SSE THROUGH CNTRL MANITOBA.
290K ISENTROPIC LIFT AHEAD OF A SFC LOW OVER THE CNTRL DAKOTAS
SUPPORTED AREAS OF RAIN OVER THE ERN DAKOTAS INTO WRN MN. 850 MB
TEMPS AROUND -4C HELPED TO MAINTAIN A LAKE INDUCED TROUGH OVER LAKE
SUPERIOR IN THE LIGHT WIND REGIME. ISOLD LAKE EFFECT -SHRA LINGERED
INTO NW UPPER MI AND ERN LAKE SUPERIOR.
THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE SHORTWAVES AND
SFC LOW MOVING INTO THE WRN GREAT LAKES. AS THE SFC LOW TRACKS FROM
WRN MN SUNDAY MORNING TO THE SE END OF LAKE SUPERIOR EARLY MON
MORNING...DEEP LAYER QVECTOR CONV AND 285K-295K ISENTROPIC LIFT WILL
SUPPORT AN AREA OF PCPN MOVING INTO SW UPPER MI SUN AFTERNOON AND
ACROSS THE CWA SUN NIGHT. PCPN AMOUNTS IN THE 0.25 TO 0.50 INCH
RANGE ARE EXPECTED. MODEL FCST SOUNDINGS...AND WET-BULB ZERO HEIGHTS
SUPPORT THE POTENTIAL FOR A SOME SNOW ACCUMULATION OVER THE HIGHER
TERRAIN OF THE WEST HALF OF UPPER MI. WITH ONLY LIGHT TO MODERATE
SNOWFALL RATES EXPECTED...AND RELATIVELY LOW SNOW/WATER RATIO VALUES
BELOW 10/1...ANY SNOW ACCUMULATION SHOULD GENERALLY REMAIN AT OR
BELOW 2 INCHES. THERE MAY ALSO BE SOME ADDITIONAL LAKE ENHANCED SNOW
INTO NW UPPER MI LATE AS WNW WINDS STRENGTHEN BEHIND THE LOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 337 AM EDT SUN OCT 20 2013
AN ACTIVE WEATHER PATTERN IS IN STORE FOR THE UPPER GREAT LAKES
REGION FOR THE UPCOMING WORK WEEK. THE UPPER TROUGH THAT IS
AFFECTING THE UPPER GREAT LAKES WILL BE RE-ENFORCED BY A SHORTWAVE
CURRENTLY DROPPING SOUTH OVER LAKE WINNIPEG. THIS WAVE WILL CATCH
UP WITH THE SURFACE LOW AND SHORTWAVE IN SOUTHERN MINNESOTA
(CURRENTLY IN WESTERN NORTH DAKOTA) AND INTENSIFY THE LOW TONIGHT
AS THE SHORTWAVES PHASE...CAUSING THE LOW TO LIFT NORTHEAST AND
OVER EASTERN LAKE SUPERIOR BY 12Z MONDAY. MODELS SEEM TO BE COMING
INTO BETTER AGREEMENT ON THE TRACK/INTENSITY OF THE LOW AS IT MOVES
NORTH FROM EASTERN LAKE SUPERIOR ON MONDAY...WHILE LEAVING A
SURFACE TROUGH BACK OVER THE LAKE THROUGH MONDAY NIGHT.
EXPECT THE INITIAL SURGE OF PRECIPITATION THAT MOVES THROUGH SUNDAY
AFTERNOON/NIGHT TO BE PUSHING NORTHEAST OF UPPER MICHIGAN.
THUS...WITH COLD AIR SURGING EAST ACROSS UPPER MICHIGAN UNDER THE
GUSTY WESTERLY FLOW...EXPECT THE MAIN WEATHER TO START MONDAY TO BE
WESTERLY WIND LAKE ENHANCED PRECIPITATION. THIS IS DUE TO 850MB
TEMPS FALLING TO -8C OVER WESTERN UPPER MICHIGAN BY 18Z MONDAY.
WILL HIGHLIGHT THE HIGHEST POPS OVER THE HIGHER TERRAIN FROM THE
KEWEENAW THROUGH THE GOGEBIC RANGE AND ALSO OVER THE HURON
MOUNTAINS. WESTERLY WINDS LOOK TO BACK SLIGHTLY IN THE AFTERNOON
AHEAD OF TROUGH DROPPING SOUTH ACROSS WESTERN LAKE SUPERIOR DURING
THE LATE AFTERNOON. THIS MAY CAUSE THE BEST PRECIPITATION TO BE
FOCUSED MORE OVER THE KEWEENAW DURING THE AFTERNOON. THEREFORE...DID
OPT TO TRIM POP/QPF AMOUNTS OVER GOGEBIC/ONTONAGON COUNTIES SOME
DURING THE AFTERNOON HOURS. SINCE WETBULB ZERO VALUES FALL OVER THE
WEST AS THE COLD AIR SURGES EAST ACROSS THE U.P. EXPECT PRECIP TO
FALL AS SNOW OVER THE WEST...BUT COULD MIX WITH RAIN AT TIMES NEAR
LAKE SUPERIOR. SNOWFALL AMOUNTS DURING THE MORNING AND MOST OF THE
AFTERNOON SHOULD BE LIGHT...WITH LOCATIONS SEEING AMOUNTS UNDER AN
INCH. OVER THE REST OF UPPER MICHIGAN DURING THIS PERIOD...EXPECT
BREEZY WESTERLY WINDS AND CLOUDY CONDITIONS...BUT LITTLE TO NO
PRECIPITATION IS EXPECTED. THE BEST OPPORTUNITY WOULD BE OVER THE
EAST RIGHT ALONG THE LAKE SUPERIOR/MICHIGAN SHORELINES AS LAKE
ENHANCED PRECIPITATION WILL TRY TO PARALLEL THOSE AREAS.
THEN TOWARDS SUNSET...THE SURFACE TROUGH WILL DROP SOUTH ONTO THE
WESTERN U.P. SHORELINE AND BRING AN ENHANCED AREA OF CONVERGENCE
AND PRECIPITATION. EXPECT THERE TO BE MODERATE TO HEAVY
PRECIPITATION AS THIS TROUGH SLIDES THROUGH THE WESTERN U.P. DURING
THE EVENING HOURS AND THEN THROUGH CENTRAL UPPER MICHIGAN DURING
THE OVERNIGHT HOURS. 850MB TEMPS WILL ACTUALLY WARM A COUPLE
DEGREES BEHIND THE TROUGH...BUT THE DEEP MOISTURE AND CYCLONIC
FLOW ON THE BACK SIDE OF THE SURFACE AND 850MB LOW...ALONG WITH
UPSLOPE WINDS...WILL SUPPORT LAKE ENHANCED PRECIPITATION THROUGH A
GOOD PORTION OF THE NIGHT OVER THE WESTERN CWA AND INTO TUESDAY
MORNING OVER THE NORTH CENTRAL CWA. THE PRECIPITATION DURING THIS
PERIOD SHOULD FALL AS SNOW EXCEPT FOR LOCATIONS RIGHT ALONG THE
LAKE SUPERIOR SHORELINE WHERE THE NORTH-NORTHWEST WINDS WOULD
PRODUCE SOME HEAT TRANSFER FROM THE LAKE AND LEAD TO SOME RAIN/SNOW
MIX. AS FOR RATIOS/AMOUNTS...THINKING THE SNOW RATIOS WILL BE AROUND
OR JUST BELOW 10-1 WITH THE BEST FORCING BEING BELOW THE DGZ AND
SNOW FLAKES FALLING FROM ALOFT CLUMPING TOGETHER AS THEY REACH THE
STRONG UPWARD MOTION NEAR THE SURFACE. AS FOR QPF AMOUNTS...HPC
INDICATES NAM IS THE COLDER SOLUTION IN THE MID LEVELS (BY AROUND
2C) BEHIND THE LOW...WHICH MAY BE PART OF THE REASON IT IS MUCH
HIGHER ON QPF AMOUNTS WITH THE LAKE ENHANCED SNOW BEHIND THE
TROUGH. SINCE THE HIGHER RESOLUTION OF THE NAM AND 4KM
NEST PICK UP THE TERRAIN ENHANCEMENT...DID BLEND THAT
WITH THE PREFERRED WARMER AND COARSER MODELS FOR QPF
MONDAY AFTERNOON THROUGH TUESDAY MORNING. THIS CREATES
24HR VALUES OF 0.5-0.75IN FROM IRONWOOD THROUGH THE
KEWEENAW AND ALSO OVER THE WESTERN SIDE OF THE HURON
MOUNTAINS. AT 10-1 SLR VALUE...SNOWFALL AMOUNTS IN THE 3-6 INCH
RANGE SEEM REASONABLE IN THOSE AREAS AFTER FACTORING SOME
MELTING INITIALLY ON MONDAY WHEN THE SNOWFALL RATES ARE LIGHTER.
THAT SEEMS TO FIT IN WITH OUR ADVISORY CRITERIA AND WILL LIKELY END
UP JUST UNDER THE 6INCH IN 12HR MARK FOR WARNINGS. CIPS TOP ANALOGS
(BASED OFF THE SLIGHTLY COLDER NAM SOLUTION) SHOW MEAN SNOWFALL
AMOUNTS OF 4-8 INCHES OF A 72HR PERIOD AND PROBABILITIES OF SEEING
6IN OF SNOW AROUND 60 PERCENT. THINK THE FORECAST MATCHES UP PRETTY
WELL WITH THAT IDEA (ALONG WITH HPC GUIDANCE) AND WILL CONTINUE TO
HIGHLIGHT THIS MEASUREABLE SNOW EVENT IN THE HWO AND ISSUE AN SPS TO
HIGHTEN THE AWARENESS.
SURFACE TROUGH WILL QUICKLY SHIFT EAST OF THE AREA ON
TUESDAY...AS AN AREA OF HIGH PRESSURE SLIDES INTO THE NORTHERN
PLAINS. EXPECT A DIMINISHING PRECIPITATION TREND FROM WEST TO EAST
ACROSS THE CWA WITH THE DEEPER MOISTURE DEPARTING. THROUGH THE REST
OF THE WEEK...EXPECT NORTHWESTERLY FLOW TO BE IN PLACE AS THE LOW
SITS OVER QUEBEC AND A SERIES OF HIGHS DROP SOUTHEAST THROUGH THE
NORTHERN PLAINS. 850MB TEMPS THROUGH THE REST OF THE PERIOD SHOULD
BE RIGHT AROUND -8C WHICH LEADS TO PLENTY OF LAKE INSTABILITY. WILL
CONTINUE TO HIGHLIGHT CHANCE POPS OR HIGHER IN THE TRADITIONAL
NORTHWEST FLOW LOCATIONS THROUGH FRIDAY. HIGHEST POPS AND POTENTIAL
FOR ACCUMULATION SNOWFALL WILL BE OVER THE EASTERN U.P. WITH THE
LONGER FETCH AND CLOSER PROXIMITY TO THE BETTER MOISTURE UNDER THE
UPPER LOW. THERE WILL BE A COUPLE BRIEF PERIODS WHERE THE LAKE
EFFECT PRECIPITATION WILL PICKUP AS WEAK SHORTWAVES AND BETTER
MOISTURE SWEEP THROUGH. CIPS TOP ANALOGS FOR THE MID WEEK PERIOD
UNDER PERSISTENT LAKE EFFECT SNOWFALL SHOWS PROBABILITY FOR 4IN OF
SNOW IN A 72HR PERIOD BEING AROUND 60 PERCENT IN THE TRADITIONAL
FAVORED NORTHWEST FLOW LOCATIONS. BEING THAT IS OVER A 3 DAY
PERIOD...THING THOSE VALUES ARE REASONABLE WITH LIGHT ACCUMULATIONS
OCCURRING THROUGH THE END OF THE WORK WEEK.
THE UPPER TROUGHS INFLUENCE ON THE UPPER GREAT LAKES LOOKS TO
WEAKEN THIS WEEKEND AS IT SHIFTS EAST INTO THE NEW ENGLAND STATES.
BUT ANOTHER SHORTWAVE ROUNDING THE UPPER RIDGE OVER THE ROCKIES
WILL TRY TO MOVE INTO THE AREA FOR THE SECOND HALF OF THE WEEKEND.
WILL JUST GO WITH A GENERAL CONSENSUS AND HAVE CHANCE POPS WITH
TEMPERATURES REMAINING BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 129 AM EDT SUN OCT 20 2013
WITH AN UPSLOPE W WIND COMPONENT AND FAIRLY MOIST/CHILLY AIRMASS
FLOWING OVER THE RELATIVELY WARM WATERS OF WRN LK SUP...SOME LO CLDS
AND AT LEAST OCNL MVFR CIGS WL IMPACT IWD AND ESPECIALLY CMX THRU
MUCH OF THE NGT. DOWNSLOPE NATURE OF THE FLOW SHOULD MAINTAIN VFR
CONDITIONS AT SAW. ARRIVAL OF WEAK HI PRES RDG SHOULD BRING VFR WX
TO ALL THE SITES FOR MUCH OF THE DAY SUN...BUT THICKER CLDS/RA WL
ARRIVE SW TO NE SUN AFTN/EVNG AHEAD OF LO PRES MOVING THRU THE UPR
LKS. EXPECT CONDITIONS TO DETERIORATE TO MVFR AT ALL 3 SITES AND
EVEN IFR AT IWD UNDER STEADY RA WITH UPSLOPE N WIND.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 510 AM EDT SUN OCT 20 2013
LOW PRESSURE MOVEING OUT OF THE DAKOTAS WILL BEGIN TO INTENSIFY OVER
THE UPPER MISSISSIPPI VALLEY TODAY AND THEN MOVE THROUGH THE UPPER
GREAT LAKES TONIGHT AND MONDAY. AS THIS OCCURS...WINDS WILL
STRENGTHEN ACROSS THE LAKE...FIRST OUT OF THE SOUTH TO SOUTHEAST
AHEAD OF THE LOW THIS EVENING AND THEN OUT OF THE WEST BEHIND THE
LOW LATE TONIGHT INTO MONDAY. THERE STILL ARE SOME DIFFERENCES
IN THE EXACT TRACK AND STRENGTH OF THE LOW AS IT MOVES ACROSS LAKE
SUPERIOR ON MONDAY...SO WIND SPEED/DIRECTIONS ARE STILL UNCERTAIN.
AT THIS TIME...IT APPEARS THE STRONGEST WINDS WILL BE BEHIND THE LOW
ON MONDAY AND MONDAY NIGHT...WHEN WEST GALES TO 35-40KTS VEERING TO
THE NORTH ARE EXPECTED. ONCE THE LOW DEPARTS THE AREA...EXPECT
NORTHWESTERLY WINDS UP TO 25KTS TO REMAIN OVER LAKE SUPERIOR INTO
WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH TUESDAY AFTERNOON FOR
LSZ265>267.
GALE WATCH FROM MONDAY EVENING THROUGH TUESDAY MORNING FOR
LSZ264.
GALE WATCH FROM MONDAY MORNING THROUGH TUESDAY MORNING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
338 AM EDT SUN OCT 20 2013
.SYNOPSIS...
ISSUED AT 335 AM EDT SUN OCT 20 2013
COOL WEATHER WITH PERIODS OF LAKE EFFECT SHOWERS WILL CONTINUE
INTO NEXT WEEK...AS A BROAD TROUGH OF LOW PRESSURE REMAINS OVER THE
GREAT LAKES. EVEN COLDER AIR WILL ENGULF THE GREAT LAKES AND UPPER
MIDWEST BY MONDAY...AS ANOTHER WEAK STORM SYSTEM EXITS NORTHEAST
INTO QUEBEC EARLY IN THE WORK WEEK. TEMPERATURES MAY GET COLD ENOUGH
TO BRING THE FIRST SNOWFALL OF THE SEASON...ESPECIALLY TO INTERIOR
SECTIONS OF EASTERN UPPER AND NORTHERN LOWER MICHIGAN.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 335 AM EDT SUN OCT 20 2013
MUCH DISCUSSED DEEP TROUGHING CONTINUES TO DOMINATE GREAT LAKES
WEATHER AT THIS EARLY HOUR...DOWNSTREAM OF EQUALLY IMPRESSIVE
RIDGING POCKING UP AND BEYOND THE NORTHWEST TERRITORIES. SUBTLE WAVE
TRAVERSING WITHIN THIS FLOW...NOW IN THE PROCESS OF FURTHER
DEAMPLIFYING AND CUTTING ACROSS THE NORTHERN LAKES. THIS...COMBINED
WITH STILL MORE THAN SUPPORTIVE OVER-WATER INSTABILITY (H8
TEMPERATURES RIGHT AROUND -2C PER HIGH RES RAP AND 00Z SOUNDING
ANALYSIS)...CONTINUES TO KICK OFF LAKE ENHANCED RAIN SHOWERS OFF
NORTHERN LAKE MICHIGAN (EVEN HAD SOME LEGITIMATE SNOWFLAKES MIX IN
WITH THE RAIN HERE ON TOP OF THE HILL). OTHERWISE...A RATHER QUIET
AND TOUCH CHILLY NIGHT...WITH CURRENT READINGS MAINLY IN THE 30S AND
LOWER 40S. MAIN SYSTEM OF INTEREST THROUGH THE SHORT TERM IS WELL
DEFINED SHORTWAVE/VORT LOBE DROPPING STRAIGHT SOUTH THROUGH CENTRAL
MANITOBA. THIS SYSTEM WILL DRUM UP A RATHER RESPECTABLE AREA OF LOW
PRESSURE TONIGHT AS IT DROPS INTO MINNESOTA. GOOD MID LEVEL SUPPORT
AND LOW LEVEL ENERGY SUPPLIED BY WARM LAKE WATERS WILL HELP DEEPEN
THIS SURFACE LOW AS IT MOVES UP INTO EASTERN LAKE SUPERIOR BY MONDAY
MORNING. THIS SYSTEM WILL BRING MORE WIDESPREAD RAINS HEADING INTO
TONIGHT...AND PERHAPS A GALE EVENT ON PARTS OF THE BIG WATERS. SHORT
TERM FORECAST CONCERNS CENTER ON ADDRESSING THE IMPACTS OF THIS
SYSTEM.
BY AND LARGE...A RATHER NON-EVENTFUL WEATHER DAY EXPECTED TODAY.
CURRENT OVERHEAD WAVE WILL HAVE EXITED STAGE RIGHT BY
SUNRISE...LEAVING PURE LAKE PROCESSES FOR ANY ADDITIONAL SHOWER
DEVELOPMENT THROUGH MID AFTERNOON. EXPECT THERE WILL BE SOME ONGOING
TO START THE DAY...ESPECIALLY ALONG THE NORTHWEST LOWER COASTLINE
WHERE WIND CONVERGENCE WILL BE MAXIMIZED. LAKE PROCESSES WILL BE A
DOWNWARD ONE HEADING THROUGH THE DAY AS WINDS BACK SOUTHERLY AND
WEAK MID LEVEL RIDGING BUILDS OVERHEAD. ATTENTION LATE THIS
AFTERNOON INTO THE OVERNIGHT TURNS TO STRONG WAA RESPONSE AHEAD OF
EARLIER MENTIONED DEEPENING SURFACE LOW. RATHER IMPRESSIVE
ISENTROPIC UPGLIDE SIGNATURE VIA FORCED ASCENT ON NOSE OF 40+ KNOT
LOW LEVEL JET...WITH WELL OVER HALF INCH PWATS ALSO SURGING NORTH
INTO THE AREA WITH THIS JET. ABOVE LOOKS TO KICK OFF A RATHER LARGE
AREA OF RAIN...WHICH WILL SPREAD RAPIDLY NORTHEAST ACROSS OUR AREA
LATE THIS AFTERNOON INTO THIS EVENING. PER FULL 00Z GUIDANCE
ANALYSIS...MAY AMP UP RAIN CHANCES SOME SOUTHWEST THIRD OF THE AREA
AFTER 21Z TODAY...WITH INHERITED CATEGORICAL WORDING INTO THIS
EVENING LOOKING GREAT. DRY SLOT PUNCHES IN FROM THE SOUTHWEST
THROUGH THE OVERNIGHT...LIKELY ABRUPTLY ENDING RAINS AS IT DOES SO.
MAY SEE SOME LAKE SHOWERS ATTEMPT TO FIRE FAR NORTHERN LAKE MICHIGAN
TOWARDS MORNING WHERE MOISTURE WILL REMAIN DEEPER AND POST-COLD
FRONT CAA REGIME ONCE AGAIN DROPS H8 READINGS TO JUST BELOW 0C.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 335 AM EDT SUN OCT 20 2013
CLASSIC LATE AUTUMN WX WILL REMAIN IN PLACE FOR THE UPCOMING
WEEK...A BIT AHEAD OF SCHEDULE. PLENTY OF UPPER TROFFING WILL REMAIN
IN PLACE IN CENTRAL CANADA AND ADJOINING PARTS OF THE STATES. THE
LOWEST HEIGHTS WILL BE OVERHEAD MONDAY EVENING...AS AN UPPER LOW
CROSSES EASTERN SUPERIOR. HOWEVER...HEIGHT RECOVERY AFTER THAT LOW
EJECTS TO THE NE WILL BE ANEMIC. THAT WILL MAINTAIN MIXED PRECIP AS
A SIGNIFICANT FORECAST CONCERN...ESPECIALLY DURING THE LATE NIGHT/
EARLY MORNING HOURS. PRECIP TRENDS ARE THE MAIN CONCERN.
MONDAY...500MB LOW MOVES FROM INL TO MQT. 999MB SURFACE LOW OVER
EASTERN SUPERIOR WILL LIFT NE TO SSW OF JAMES BAY...WITH A NEW LOW
SPINNING UP ALONG A SECONDARY COLD FRONT IN CENTRAL SUPERIOR DURING
THE AFTERNOON. THE BACK EDGE OF THE WARM CONVEYOR BELT WILL BE ABOUT
TO EXIT NE LOWER MI AT 12Z...WITH DRIER MID LEVEL AIR IN THE PROCESS
OF POURING INTO NORTHERN LOWER. HOWEVER...OVERLAKE INSTABILITY WILL
BE INCREASING CONSIDERABLY AS COLDER LOW LEVEL AIR POURS IN. 850MB
TEMPS OVER NORTHERN LAKE MI WILL NEAR -6C BY 18Z...-8C BY 00Z.
MEANWHILE...EASTERN UPPER WILL REMAIN ON THE SOUTHERN PERIPHERY OF
THE DEEPER WRAPAROUND MOISTURE.
COULD STILL BE SOME FRONTAL SHRA IN FAR EASTERN SECTIONS TO START
THE MORNING. SCT SHRA WILL GET GOING IN WSW-FLOW AREAS (ESPECIALLY
FROM LEELANAU NORTHWARD) DURING THE MORNING...AS WELL AS IN EASTERN
UPPER. THESE COULD BECOME MORE NUMEROUS IN THE AFTERNOON...AS
INSTABILITY INCREASES (DELTA T/S IN THE LOWER 20S) AND THE CORE OF
THE DRY SLOT MOVES EAST. 1000-850MB WINDS WILL VEER TO THE WEST
DURING THE AFTERNOON...WITH INVERSION HEIGHTS A REASONABLY HEALTHY
6-7K FT. WILL INTRODUCE A SMALL CHANCE FOR A MIX VERY LATE IN THE
DAY IN THE INTERIOR OF EASTERN UPPER...WHERE THE SURFACE-BASED
MELTING LAYER IS NARROWING BELOW 1K FT.
MAX TEMPS IN THE 40S (TO LOWER 50S NE LOWER) AND EARLY...WITH
FALLING TEMPS IN THE PM. BRISK TO WINDY...ESPECIALLY NEAR LAKE MI.
MON NIGHT/TUESDAY...UPPER LOW WILL GRADUALLY LIFT OUT TOWARD JAMES
BAY...THOUGH WITH A SUBSTANTIAL SHORTWAVE ROUNDING IT/S SOUTHERN
FLANK LATE MONDAY NIGHT. THAT WILL DRIVE THE SECONDARY FRONT INTO
EASTERN UPPER MI LATE MONDAY NIGHT...AND ACROSS THE REST OF THE
FORECAST AREA ON TUESDAY. 1000-850MB WINDS WILL BRIEFLY BACK MORE
WSW AGAIN JUST AHEAD OF THIS TROF...ALLOWING THE INITIAL 850MB
THERMAL TROF TO MOVE EAST AND BOOSTING 850MB TEMPS TO -5C. WINDS
RAPIDLY VEER NW BEHIND THE TROF...AND COLD ADVECTION RESUMES. AFTER
CONTINUED LOW-END-ISH LAKE EFFECT MONDAY EVENING (THOUGH WITH MORE
SNOW MIXING IN AS DIURNAL HEATING IS LOST)...PRECIP WILL
SUBSTANTIALLY RAMP UP OVERNIGHT AS THE SECONDARY FRONT AND SHARP
1000-850MB CONVERGENCE ARRIVES. SLUSHY ACCUMS UP TO AN INCH SEEM A
DISTINCT POSSIBILITY MONDAY NIGHT NEAR GLR/BOYNE CITY/MANCELONA...
AND IN WESTERN CHIP. TUESDAY WILL SEE A WOBBLY NW FLOW...BUT WITH
MID-LEVEL DRYING/SUBSIDENCE AS THE VORT LOBE MOVES EAST. SOME LAKE
EFFECT WILL CONTINUE...ESPECIALLY IN THE MORNING...WITH DISRUPTIVE
DIURNAL HEATING DISORGANIZING THINGS IN THE PM. SOME SLOPPY LIGHT
ACCUMS ARE AGAIN POSSIBLE IN THE MOST FAVORED AREAS OF BOTH
PENINSULAS IN THE MORNING.
MIN TEMPS WITHIN A FEW DEGREES OF 30F. MAX TEMPS NEAR 40F TO THE MID
40S. AND IT WILL REMAIN BRISK TO WINDY.
REST OF THE FORECAST...FEW CHANGES NEEDED...AS COLD AND SHOWERY WX
WILL PERSIST AS CURRENTLY FORECAST. NEW ECMWF IS FLAT-OUT COLD
STRAIGHT THRU 240HRS. (PROBABLY BEST FOR MOTHER NATURE TO GET THIS
OUT OF HER SYSTEM NOW.)
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1100 PM EDT SAT OCT 19 2013
SCT/NMRS LAKE ENHANCED RAIN SHOWERS WILL CONTINUE TO IMPACT NRN
LWR MICHIGAN TAF SITES THRU SUNDAY NIGHT THANKS TO DEEP CYCLONIC
FLOW...COLD AIR ACTIVATING THE LAKES AND AMPLE LOW LEVEL MOISTURE.
OVERALL...CIGS WILL REMAIN LOW VFR...BUT MAY BRIEFLY DROP TO HIGH
MVFR WITHIN SOME OF THE HEAVIER SHOWER ACTIVITY. WESTERLY WINDS
UNDER 10 KTS TONIGHT WILL SHIFT TO THE S/SW ON SUNDAY AHEAD OF
DEEPENING LOW PRESSURE SLIDING INTO THE UPPER MISSISSIPPI VALLEY.
&&
.MARINE...
ISSUED AT 335 AM EDT SUN OCT 20 2013
RELATIVELY LIGHT WINDS THIS MORNING GIVES WAY TO
INCREASINGLY GUSTY SOUTH FLOW LATER THIS AFTERNOON...AND ESPECIALLY
TONIGHT...AS LOW PRESSURE INTENSIFIES AND PUSHES INTO EASTERN LAKE
SUPERIOR BY MONDAY MORNING. TIGHTENING PRESSURE GRADIENT AND ONSET
OF IMPRESSIVE SURGE OF CAA WILL LEAD TO VERY GUSTY WEST TO SOUTHWEST
WINDS DURING THE DAY MONDAY...WITH THE STRONGEST WINDS EXPECTED OVER
NORTHERN LAKE MICHIGAN. GALE FORCE WIND GUSTS APPEAR INCREASINGLY
LIKELY...RESULTING IN AN UPGRADE TO INHERITED NORTHERN LAKE MICHIGAN
GALE WATCH TO A WARNING. IN ADDITION...WIND GUST MAY REACH GALE
FORCE ACROSS WHITEFISH BAY AND THE ST. MARYS RIVER LATER MONDAY
MORNING THROUGH THE AFTERNOON. CONFIDENCE NOT HIGH ENOUGH TO WARRANT
A GALE WARNING...BUT ENOUGH CONCERN TO HOIST A GALE WATCH FOR THESE
AREAS. ADDITIONAL SCA/S WILL LIKELY BE NEEDED FOR OTHER NEARSHORE
ZONES...BUT WILL FOCUS ON GALE CONDITIONS AND PUNT ADVISORY
ISSUANCES TO FUTURE FORECAST SHIFTS. WELCOME TO FALL ON THE GREAT
LAKES!
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...GALE WARNING FROM 5 AM MONDAY TO 11 AM EDT TUESDAY FOR LHZ345.
LM...GALE WARNING FROM 5 AM MONDAY TO 11 AM EDT TUESDAY FOR LMZ341-
342-344>346.
LS...GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR LSZ321-
322.
&&
$$
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...MR
MARINE...MB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
435 AM CDT SUN OCT 20 2013
.SHORT/LONG TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 433 AM CDT SUN OCT 20 2013
PERSISTENT NORTHWEST FLOW WILL REMAIN IN TACT THROUGHOUT THE
PERIOD...LEADING TO BELOW NORMAL TEMPERATURES AND PERIODIC CHANCES
FOR LIGHT PRECIP. GIVEN THE COLD AIR EXPECTED TO BE IN PLACE...WILL
SEE THE POTENTIAL FOR FROZEN PRECIP CARRY ON THROUGH NEXT WEEK.
ARGUABLY THE MOST INTRIGUING FEATURE IN THE EXTENDED IS THE CLIPPER
SYSTEM CURRENTLY APPROACHING THE UPPER MIDWEST. THE LATEST HIRES
MODELS PORTRAY MORE OF A SOUTHERLY TRACK...SO HAVE BROUGHT THE
HIGHEST POPS AND QPF SOUTH TO REFLECT THIS TREND. HOWEVER...BUFR
FORECAST SOUNDINGS OFF THE RAP ONLY HAVE AROUND AN INCH OF SNOW AT
MORA...AND BRAINERD...WITH LESS AT ALEXANDRIA AND ST CLOUD. THE NAM
IS CONTINUES TO ADVERTISE 4 INCHES AT MORA...BUT THIS IS LIKELY
OVERDONE CONSIDERING THAT ACCORDING TO THE NAM AS OF 5AM 1-2 INCHES
SHOULD HAVE ALREADY FALLEN AT FARGO..AND THEY HAVE YET TO RECEIVE
ANY SNOW. THE MAIN REASON FOR THE SLOW CHANGEOVER SEEMS TO BE THE
LACK OF STRONG FGEN AND FOCUSED VERTICAL MOTION IN THE WAA
REGIME...RATHER GRADUAL ISENTROPIC ASCENT WAS THE DRIVING FORCE
BEHIND THE PRECIP. THROUGHOUT THE MORNING HOURS...THE NAM DOES
INCREASE THE FGEN FORCING...WHILE THE RAP IS WEAKER. AFTER WEEDING
THROUGH THE DIFFERENT SCENARIOS...DO NOT HAVE THE CONFIDENCE IN ANY
SNOWFALL AMOUNTS EXCEEDING 3 INCHES DESPITE THE SOUTHERLY SHIFT IN
QPF. RATHER SHOULD SEE A MODEST BAND OF SNOW TRACK NORTH OF
I-94...WITH PERHAPS AN INCH OR 2 ON GRASSY SURFACES THIS
MORNING...BEFORE TRANSITIONING TO MORE OF RAIN/SNOW OR EVEN ALL RAIN
MIX LATER THIS AFTERNOON AS 1)THE BOUNDARY LAYER WARMS...AND 2) WE
LOSE THE DEEP SATURATION AND TRANSITION TO MORE OF LIGHT
RAIN/DRIZZLE SCENARIO.
BRISK NORTHWEST WINDS WILL FOLLOW ONCE THIS SYSTEM MOVES EASTWARD AS
COOLER AIR AS EVIDENT BY THE -7 TO -10C H850 TEMPS ADVECT ACROSS THE
REGION SUNDAY NIGHT INTO MONDAY. THE NORTHWEST FLOW WILL PERSIST
ACROSS THE REGION...WITH A FEW SHORTWAVES TRACKING DOWN THE POLEWARD
SIDE OF THE JET. THESE WILL INDUCE LOW LEVEL CIRCULATIONS...THE NEXT
OF WHICH IS EXPECTED TO TRACK SOUTHWEST OF THE CWA ALONG THE
MISSOURI RIVER VALLEY MONDAY NIGHT INTO TUESDAY. COLD AIR WILL AGAIN
BE REINFORCED BEHIND THIS SYSTEM...WILL NO WARM UP POTENTIAL IN
SIGHT UNTIL PERHAPS THE END OF THE WEEK AS ANOTHER WAVE MOVES ACROSS
THE REGION. DEPENDING ON THE TRACK OF THIS SYSTEM...THE UPPER
MIDWEST COULD SEE ONE DAY OF WARMER TEMPERATURES...BUT THE GUIDANCE
IS CONSISTENT THAT THIS WILL BE SHORT LIVED AS ANOTHER ARCTIC
AIRMASS WILL FOLLOW BEHIND THIS PASSING WAVE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1141 PM CDT SAT OCT 19 2013
A COMPLEX TAF PERIOD IS AHEAD AS A CLIPPER SYSTEM DIVES SOUTHEAST
ACROSS SOUTHERN MINNESOTA SUNDAY. PRECIPITATION WILL BEGIN TO
PUSH INTO WESTERN MN LATE TONIGHT AND SPREAD EAST INTO WISCONSIN
LATE SUNDAY MORNING. THERMAL PROFILES INDICATE SNOW FOR MUCH OF
CENTRAL MN...WITH A BIT OF SNOW POSSIBLE AT THE ONSET ACROSS
EASTERN MN AND WESTERN WI. THINK TEMPERATURES ARE OVERDONE ON
MOS...WHICH LEADS TO LOWER RH NEAR THE SURFACE AND THUS HIGHER
CIGS. WENT MUCH MORE PESSIMISTIC WITH THE CIGS NORTH OF THE LOW
TRACK AS INDICATED BY FORECAST SOUNDINGS AND HOPWRF MODEL.
KMSP...ONSET OF PRECIP CONTINUES TO LOOK LIKE 13 OR 14Z WITH SNOW
POSSIBLY MIXED WITH THE RAIN FOR A BRIEF TIME. BIGGEST
UNCERTAINTY WILL BE CIGS SUNDAY. THE WARM FRONT WILL BISECT THE
METRO AND MSP WILL BE SOMEWHERE BETWEEN THE IFR CIGS TO THE NORTH
AND VFR OR MVFR CIGS TO THE SOUTH IN THE WARMER AIR. A SLIGHT
NORTHWARD SHIFT OF THE FORECAST TRACK HAS LED TO A CONTINUATION
OF MVFR CIGS.
/OUTLOOK FOR KMSP/
MON...VFR WITH -RA/SN POSSIBLE. WINDS NW AT 15G25KT.
TUE...VFR WITH MVFR CIGS POSSIBLE EARLY. WINDS NW AT 5-10 KTS.
WED...MVFR CIGS POSSIBLE. WINDS W AT 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...JRB
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
204 AM EDT SUN OCT 20 2013
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION THIS EVENING FOLLOWED
BY A VISIT FROM HIGH PRESSURE ON SUNDAY AND MONDAY. THE PATTERN
WILL TURN NOTICEABLY COOLER AND UNSETTLED NEXT WEEK AS AN UPPER
TROUGH ESTABLISHES ITSELF OVER THE EASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
REGIONAL RADAR LOOP AT 02Z SHOWS A DWINDLING LINE OF SHOWERS
ASSOC WITH COLD FRONT ENTERING THE SUSQ VALLEY. DESPITE A DECENT
AMT OF MOISTURE POOLING AHEAD OF FRONT...UPPER LVL SHORTWAVE AND
ASSOC LG SCALE FORCING IS LIFTING NORTH OF THE BORDER...SO LITTLE
CHC OF MORE THAN AN ISOLD SHOWER AS FRONT PUSHES THRU THE EASTERN
COUNTIES BTWN 02Z-04Z. LATEST RAP OUTPUT INDICATES CDFRONT WILL
CLEAR THE EASTERNMOST COUNTIES /SCHUYLKILL AND LANCASTER/ BY
MIDNIGHT. BEHIND FRONT...ONLY REMAINING PRECIP WILL BE IN THE
FORM OF LAKE EFFECT RAIN SHOWERS COMING OFF OF LK ERIE. CURRENT
RADAR TRENDS AND RAP/NAM OUTPUT SUGGEST SHOWERS ACROSS
WARREN/MCKEAN COS WILL SHIFT NORTH OF THE BORDER AFTER 06Z...AS
BLYR FLOW BACKS TO THE WSW.
CLEARING SKIES ALREADY DEVELOPING EAST OF THE MTNS AT 02Z AND
EXPECT THAT TREND TO CONTINUE OVERNIGHT...AS DRIER WEST FLOW
OVERSPREADS CENTRAL PA. STRATOCU MAY LINGER FOR A WHILE ACROSS
THE LAUREL HIGHLANDS...BUT EXPECT CLEARING EVEN THERE LATE
TONIGHT. THE INITIALLY GUSTY WEST WINDS SHOULD SLACKEN LATE
TONIGHT...AS HIGH PRES RIDGE BUILDS IN FROM THE OHIO VALLEY. BLEND
OF LATEST LAMP AND RAP GUIDANCE SUGGEST TEMPS WILL BOTTOM OUT IN
THE M30S ACROSS THE ALLEGHENY PLATEAU...TO THE L40S OVR THE SUSQ
VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
HIGH PRESSURE WILL PASS JUST SOUTH OF THE STATE ON SUNDAY...PROVIDING
THE AREA WITH SEASONABLY COOL AND DRY WX. ALTHOUGH A WSW BLYR FLOW
WILL KEEP LINGERING LAKE EFFECT ACTIVITY NORTH OF THE
BORDER...COLD TEMPS ALOFT SHOULD YIELD A GOOD AMT OF DIURNAL
STRATOCU ACROSS THE NW MTNS. WIND WILL INCREASE A BIT FROM A MORNING
LULL...AS THE ATMOS MIXES. MDL SOUNDINGS SUPPORT AFTN GUSTS BTWN
20-25KTS ACROSS THE NW MTNS...AND BTWN 10-15KTS ACROSS THE LOWER
SUSQ VALLEY.
HIGH TEMPS UNDER THE RATHER HOMOGENEOUS 0C-M2C 8H TEMPS WILL BE
ALMOST ENTIRELY DEPENDENT ON ELEVATION AND DOWNSLOPE WARMING.
MAXES SHOULD BE CLOSE TO 50F IN THE NW MTNS AND NEAR 60F IN THE
VALLEYS/LOWER ELEVS OF THE SUSQ VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
CENTRAL PA WILL BE ON NORTHERN EDGE OF ERODING HIGH PRESSURE RIDGE
SUN NIGHT INTO MON...WITH A WARM FRONT LIFTING THROUGH OHIO VALLEY
AND SKIRTING W PA. THIS WILL KEEP WEATHER FAIR AND MILD...WITH
HIGHS MONDAY SLIPPING INTO THE 60S /ABOUT 4-8F ABOVE NORMAL/.
THINGS START TO GO DOWNHILL MONDAY NIGHT AS NEW ENERGY STARTS
DIVING OUT OF SOUTHERN CANADA ON THE WAY TO CARVING OUT A LARGE
SCALE PERSISTENT TROF OVER THE EASTERN U.S. A BUILDING RIDGE OVER
THE WEST COAST WILL HELP DEEPEN AN ADVANCING LOW...WHICH WILL
DELIVER A STEADY FEED OF INCREASINGLY MORE CHILLY AIR ACROSS THE
UPPER MIDWEST NEXT WEEK. THIS COLD AIR WILL PROPAGATE INTO THE
LOWER LAKES AND LOCAL AREA IN THE WAKE OF A COLD FRONTAL BOUNDARY
PROGGED FOR TUESDAY...AND REINFORCED BY SECONDARY TROUGH ON
WEDNESDAY /AS ANOTHER LOW FORMS ALONG THE BOUNDARY AND SLIDES
ACROSS MID ATLANTIC STATES JUST TO OUR SOUTH BEFORE SLIDING OFF
THE COAST OF NEW ENGLAND/.
SOME DIFFERENCES CONTINUE IN MODEL SOLUTIONS STARTING AROUND
WEDNESDAY WHEN THE ECMWF BRINGS A STRONG SHORTWAVE OUT OF THE
OHIO VALLEY. THE OPERATIONAL GFS AND THE GEFS /PREVIOUSLY WITH A
FLATTER TROUGH/ ARE COMING MORE IN LINE WITH THE EC...WHICH WILL
INCREASE OUR POP CHANCES FOR WED WITH A STEADY LIGHT RAIN POSS.
AFTER THAT...CYCLONIC FLOW WILL CONTINUE TO ALLOW INCREASINGLY
COOLER AIR TO FILTER IN ON NW FLOW. PLENTY OF COLD ADVECTION
STRATOCU AND LAKE/OROGRAPHIC SHOWERS LOOKING LIKELY IN THE HIGHER
WESTERN TERRAIN MID/LATE WEEK...WITH DOWNSLOPE COMPONENT TO WINDS
KEEPING PRECIP AT A MIN FOR THE SE. LOW LEVEL TEMPS GET COLD
ENOUGH /850MB TEMPS DIP BELOW 0C/ THAT LIGHT SHOWERS COULD BE
MIXED WITH WET SNOW DURING THE CHILLIEST PART OF THE DAY AND
OVERNIGHT.
HIGH PRESSURE BUILDS IN LOW LEVELS FOR THE WEEKEND...BRINGING
QUITE CHILLY MORNING TEMPS. BUT AN OVERALL MORE SETTLED WEATHER
PATTERN. REINFORCING SHOT OF COLDER AIR POSS EARLY NEXT WEEK.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
MOST OF THE SHOWERS OFF LAKE ERIE WILL BE NORTH OF OUR AREA...
BUT CLOUDS WILL LINGER INTO LATE MORNING OR EARLY AFT...GIVEN
THE STRONG FLOW OF COLD AIR OVER THE LAKE. THE AIRMASS IS COLD
ENOUGH TO RESLULT IN RADAR RETURNS OF ALMOST 50 DBZ ALONG THE
LAKE ERIE SHORELINE.
ANYWAY...AS WINDS SHIFT MORE TO THE SW THIS AFTERNOON AND
WEAKEN...CLOUDS WILL THIN OUT.
CLOUDS INCREASE ACROSS THE AREA BY MONDAY MORNING...AS ANOTHER
LOW PRESSURE SYSTEM LIFTS NE ACROSS THE LOWER LAKES REGION.
SOME SHOWERS WILL BE POSSIBLE LATER MONDAY AFT INTO TUE...AS
THE NEXT COLD FRONT MOVES ACROSS THE AREA.
OUTLOOK...
TUE...FROPA. MVFR/IFR POSS DUE TO SHOWERS/CLOUDS...ESP NW.
WED...MVFR POSS IN SHRA...ESP NW.
THURS...BREEZY...MVFR CLOUDS/SHRA N/W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO/FITZGERALD
LONG TERM...RXR
AVIATION...JUNG/MARTIN
AREA FORECAST DISCUSSION
NWS MIAMI FL
1022 AM EDT SUN OCT 20 2013
.UPDATE...
DO NOT PLAN ANY CHANGES TO MORNING UPDATES WITH THE 12Z MFL
SOUNDING INDICATING SUBSIDENCE CAP STILL IN PLACE WITH A STABLE
LAYER BETWEEN 800 AND 650 MB. ATMOSPHERE ALSO REMAINS QUITE DRY
WITH PWAT AT AROUND 1.5 INCHES. THE LOWER LAYERS HAVE MOISTENED UP
WITH DEW POINTS BACK INTO THE LOWER AND MID 70S SO CU FIELD
ALREADY FORMING AND COULD HAVE SOME EARLY ONSET OF LOW TOPPED
SHOWERS AND IF ANY CAN OVERCOME THE CAP, THEN A THUNDERSTORM
CANNOT BE RULED OUT WITH QUITE A BIT OF LIGHTNING LATE YESTERDAY
OVER WESTERN PALM BEACH COUNTY. THE HRRR DOES SHOW THIS TREND WITH
LATE AFTERNOON CONVECTION OVER THE SAME AREA. WILL WAIT FOR
EARLIER THIS AFTERNOON, BUT MAY NEED TO EXPAND THE CHANCE POP
COVERAGE A LITTLER FARTHER TO THE EAST BUT NOTHING MORE DRASTIC
THAN THAT PLANNED AT THIS TIME.
KOB
&&
.PREV DISCUSSION... /ISSUED 657 AM EDT SUN OCT 20 2013/
AVIATION...
A WEAK, DIFFUSE BOUNDARY ACROSS THE FLORIDA PENINSULA HAS BEEN A
FOCAL POINT FOR SOME ISOLATED TO SCATTERED SHOWERS. THIS BOUNDARY
WILL CONTINUE TO AFFECT THE WEATHER TODAY, WITH A CHANCE OF
SHOWERS, MAINLY IN THE LAKE REGION OF SOUTH FLORIDA, WHICH SHOULD
NOT IMPACT ANY TAF SITES. HOWEVER, THERE IS A VERY LOW POSSIBILITY
THAT A BRIEF CONVECTIVE CELL COULD IMPACT ANY GIVEN TAF SITE.
OTHERWISE, VFR CONDITIONS ARE EXPECTED. ALSO, BEING SOUTH OF THE
BOUNDARY WILL KEEP WINDS GENERALLY SOUTHERLY TODAY, PICKING UP TO
5 TO 10 KTS. THEY WILL GO LIGHT AND VARIABLE AGAIN TONIGHT.
PREV DISCUSSION... /ISSUED 358 AM EDT SUN OCT 20 2013/
DISCUSSION...
A WEAK SURFACE TROUGH JUST WEST OF THE FLORIDA KEYS CONTINUES TO
GENERATE A FEW SHOWERS WEST AND SOUTH OF KEY WEST EARLY THIS
MORNING. THIS TROUGH IS EXPECTED TO LINGER THROUGH THE DAY AND ACT
AS A FOCUS FOR ADDITIONAL SHOWERS MAINLY ACROSS THE GULF WATERS.
FOR SOUTH FLORIDA...SHOWERS AND POSSIBLY A FEW THUNDERSTORMS WILL
AGAIN BE POSSIBLE THROUGH THE AFTERNOON HOURS. SOUTHWEST FLOW
ALOFT WILL CONTINUE TO FUNNEL LOW LEVEL MOISTURE INTO THE AREA.
THIS COMBINED WITH WEAK SEA BREEZE INTERACTIONS SHOULD BE ENOUGH
TO SPARK A FEW SHOWERS AND STORMS MAINLY ACROSS THE INTERIOR.
FOR MONDAY INTO TUESDAY...UPPER RIDGING ENTRENCHED ACROSS THE
FLORIDA PENINSULA WILL SLOWLY BEGIN TO BREAK DOWN AS A BROAD H5
SHORTWAVE BEGINS TO SWING DOWN THROUGH THE MIDSOUTH STATES. SLIGHT
CHANCES FOR AFTERNOON SHOWERS AND A FEW THUNDERSTORMS WILL BE
PREVALENT EACH DAY AS A SLIGHTLY DEEPER MOISTURE AXIS PUSHES INTO
SOUTH FLORIDA AHEAD OF AN APPROACHING COLD FRONT.
THE COLD FRONT IS STILL EXPECTED TO PUSH INTO THE SOUTH FLORIDA
AREA BY WEDNESDAY. MODELS TEND TO BE IN GOOD AGREEMENT ON THE
TIMING OF THE FRONTAL PASSAGE. NORTH TO NORTHEASTERLY SURFACE FLOW
WILL THEN PREVAIL AND INCREASE THROUGH THE END OF THE WEEK DUE TO
A RATHER TIGHT PRESSURE GRADIENT BETWEEN LOWER PRESSURE TO THE
SOUTH AND STRONG HIGH PRESSURE ACROSS THE SOUTHEAST STATES. THIS
WILL ALLOW NOTICEABLY MILDER TEMPERATURES TO FILTER ACROSS THE AREA
THURSDAY INTO NEXT WEEKEND. WOULD NOT BE SURPRISED TO SEE MORNING
LOWS IN THE 50S ACROSS INTERIOR AREAS FRIDAY MORNING.
THE SOUTHWARD EXTENT OF THE DRY AIR PUSH IN THE WAKE OF THE FRONTAL
PASSAGE IS UNCLEAR AT THIS TIME. BOTH THE GFS AND ECMWF SEEM TO
KEEP AN OVERRUNNING MOISTURE AXIS JUST SOUTH OF THE AREA ACROSS THE
FLORIDA STRAITS. ANY FLUCTUATION OVER THE NEXT FEW DAYS WOULD
GREATLY INFLUENCE RAIN CHANCES TOWARD THE END OF THE WEEK.
SUBSEQUENT MODEL RUNS WILL NEED TO BE MONITORED CLOSELY FOR
CONSISTENCY.
MARINE...
TRANQUIL MARINE CONDITIONS WILL CONTINUE INTO EARLY NEXT WEEK WITH
A PREVAILING E-SE WIND AT 10 KNOTS OR LESS WITH CORRESPONDING SEAS
AT 3 FEET OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 75 88 74 / 20 10 20 20
FORT LAUDERDALE 88 78 88 77 / 20 20 20 20
MIAMI 87 77 88 76 / 20 20 20 20
NAPLES 88 74 87 72 / 20 10 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1036 AM EDT SUN OCT 20 2013
.SYNOPSIS...
ISSUED AT 335 AM EDT SUN OCT 20 2013
COOL WEATHER WITH PERIODS OF LAKE EFFECT SHOWERS WILL CONTINUE
INTO NEXT WEEK...AS A BROAD TROUGH OF LOW PRESSURE REMAINS OVER THE
GREAT LAKES. EVEN COLDER AIR WILL ENGULF THE GREAT LAKES AND UPPER
MIDWEST BY MONDAY...AS ANOTHER WEAK STORM SYSTEM EXITS NORTHEAST
INTO QUEBEC EARLY IN THE WORK WEEK. TEMPERATURES MAY GET COLD ENOUGH
TO BRING THE FIRST SNOWFALL OF THE SEASON...ESPECIALLY TO INTERIOR
SECTIONS OF EASTERN UPPER AND NORTHERN LOWER MICHIGAN.
&&
.UPDATE...
ISSUED AT 1036 AM EDT SUN OCT 20 2013
GOT A BIT OF A BREAK DURING THE OVERNIGHT HOURS WITH CLOUDS THINNING/
CLEARING OUT OVER A GOOD PART OF CWA...WELL DOWNWIND OF THE LAKES.
BUT MEANWHILE...LAKE AGGREGATE TROUGH ANALYZED FROM WESTERN LAKE
SUPERIOR DOWN INTO NRN LAKE MICHIGAN THIS MORNING. MESOSCALE SFC
LOW HAS DEVELOPED OVER NRN LAKE MICHIGAN GIVEN THE WEAKER SYNOPTIC
WIND REGIME/SHORELINE ORIENTATION AND OFFSHORE WIND COMPONENT. A
FEW POCKETS OF LAKE INDUCED SHOWERS LINGER WITHIN THIS FEATURE
ACROSS NRN LAKE MICHIGAN (CAN SEE THE LOW LEVEL SPIN IN THE RADAR
DATA...PUSHING UP INTO PARTS OF NW LOWER INTO THE STRAITS AND
EASTERN UPPER.
REST OF TODAY...POTENT SHORT WAVE AND POCKET OF COLDEST AIR OF THE
SEASON ON TRACK TO DROP INTO THE UPPER MIDWEST...THAT WILL
ULTIMATELY DRIVE A DEEPENING SFC LOW/POTENT COLD FRONT THROUGH THE
REGION...LATE TONIGHT AND MONDAY MORNING. AHEAD OF THIS DEVELOPING
SYSTEM...LOW LEVEL FLOW WILL BACK MORE SOUTHERLY AS WE GO THROUGH
THE AFTERNOON...PUSHING REMAINING LAKE INDUCED SHOWERS UP THROUGH
EASTERN UPPER MICHIGAN. PULSE OF LOW-MID LEVEL WARM ADVECTION
FORCING AHEAD OF THAT DEVELOPING SYSTEM ALREADY PRODUCING A BAND
OF PRECIP EXPANDING INTO WESTERN WISCONSIN THIS MORNING. FORCING
LOOKING TO DEVELOP INTO THE W/SW PART OF THE CWA BY LATE
AFTERNOON. GOING FORECAST ALREADY HAS CHANCY POPS OVER THE SW
COUNTIES AND A SLIVER OF EASTERN UPPER MICHIGAN...WHICH LOOKS FINE
FOR NOW.
HAVE TWEAKED SKY FORECASTS FOR THE BALANCE OF THE DAY BASED ON
TRENDS...TO HAVE A LITTLE MORE SUNSHINE THROUGH MIDDAY. ALSO
TWEAKED TEMP CURVE FOR TONIGHT. BIG SURGE OF WARM AIR ALOFT AND
INCREASING SOUTHERLY WINDS SHOULD ACTUALLY RESULT IN FLAT LINE OR
EVEN WARMING TEMPS TONIGHT. JUST HOW WARM DEPENDS ON HOW FAR NORTH
THE SFC WARM FRONT CAN GET...BUT CAN ENVISION SOME LOCATIONS
PUSHING THE HIGH 40S TO NEAR 50 OVERNIGHT...BEFORE IT ALL CRASHES
ON MONDAY WITH FROPA.
UPDATE ISSUED AT 657 AM EDT SUN OCT 20 2013
CLOUDS HAVE OPENED UP CONSIDERABLY IN PARTS OF NE LOWER AND EASTERN
UPPER MI. THIS WILL TEND TO SELF-DESTRUCT WITH HEATING TODAY...THE
SUB-800MB AIRMASS REMAINS ON THE MOIST SIDE. SOME ADJUSTMENTS MADE
TO EARLY-MORNING CLOUD COVER.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 335 AM EDT SUN OCT 20 2013
MUCH DISCUSSED DEEP TROUGHING CONTINUES TO DOMINATE GREAT LAKES
WEATHER AT THIS EARLY HOUR...DOWNSTREAM OF EQUALLY IMPRESSIVE
RIDGING POCKING UP AND BEYOND THE NORTHWEST TERRITORIES. SUBTLE WAVE
TRAVERSING WITHIN THIS FLOW...NOW IN THE PROCESS OF FURTHER
DEAMPLIFYING AND CUTTING ACROSS THE NORTHERN LAKES. THIS...COMBINED
WITH STILL MORE THAN SUPPORTIVE OVER-WATER INSTABILITY (H8
TEMPERATURES RIGHT AROUND -2C PER HIGH RES RAP AND 00Z SOUNDING
ANALYSIS)...CONTINUES TO KICK OFF LAKE ENHANCED RAIN SHOWERS OFF
NORTHERN LAKE MICHIGAN (EVEN HAD SOME LEGITIMATE SNOWFLAKES MIX IN
WITH THE RAIN HERE ON TOP OF THE HILL). OTHERWISE...A RATHER QUIET
AND TOUCH CHILLY NIGHT...WITH CURRENT READINGS MAINLY IN THE 30S AND
LOWER 40S. MAIN SYSTEM OF INTEREST THROUGH THE SHORT TERM IS WELL
DEFINED SHORTWAVE/VORT LOBE DROPPING STRAIGHT SOUTH THROUGH CENTRAL
MANITOBA. THIS SYSTEM WILL DRUM UP A RATHER RESPECTABLE AREA OF LOW
PRESSURE TONIGHT AS IT DROPS INTO MINNESOTA. GOOD MID LEVEL SUPPORT
AND LOW LEVEL ENERGY SUPPLIED BY WARM LAKE WATERS WILL HELP DEEPEN
THIS SURFACE LOW AS IT MOVES UP INTO EASTERN LAKE SUPERIOR BY MONDAY
MORNING. THIS SYSTEM WILL BRING MORE WIDESPREAD RAINS HEADING INTO
TONIGHT...AND PERHAPS A GALE EVENT ON PARTS OF THE BIG WATERS. SHORT
TERM FORECAST CONCERNS CENTER ON ADDRESSING THE IMPACTS OF THIS
SYSTEM.
BY AND LARGE...A RATHER NON-EVENTFUL WEATHER DAY EXPECTED TODAY.
CURRENT OVERHEAD WAVE WILL HAVE EXITED STAGE RIGHT BY
SUNRISE...LEAVING PURE LAKE PROCESSES FOR ANY ADDITIONAL SHOWER
DEVELOPMENT THROUGH MID AFTERNOON. EXPECT THERE WILL BE SOME ONGOING
TO START THE DAY...ESPECIALLY ALONG THE NORTHWEST LOWER COASTLINE
WHERE WIND CONVERGENCE WILL BE MAXIMIZED. LAKE PROCESSES WILL BE A
DOWNWARD ONE HEADING THROUGH THE DAY AS WINDS BACK SOUTHERLY AND
WEAK MID LEVEL RIDGING BUILDS OVERHEAD. ATTENTION LATE THIS
AFTERNOON INTO THE OVERNIGHT TURNS TO STRONG WAA RESPONSE AHEAD OF
EARLIER MENTIONED DEEPENING SURFACE LOW. RATHER IMPRESSIVE
ISENTROPIC UPGLIDE SIGNATURE VIA FORCED ASCENT ON NOSE OF 40+ KNOT
LOW LEVEL JET...WITH WELL OVER HALF INCH PWATS ALSO SURGING NORTH
INTO THE AREA WITH THIS JET. ABOVE LOOKS TO KICK OFF A RATHER LARGE
AREA OF RAIN...WHICH WILL SPREAD RAPIDLY NORTHEAST ACROSS OUR AREA
LATE THIS AFTERNOON INTO THIS EVENING. PER FULL 00Z GUIDANCE
ANALYSIS...MAY AMP UP RAIN CHANCES SOME SOUTHWEST THIRD OF THE AREA
AFTER 21Z TODAY...WITH INHERITED CATEGORICAL WORDING INTO THIS
EVENING LOOKING GREAT. DRY SLOT PUNCHES IN FROM THE SOUTHWEST
THROUGH THE OVERNIGHT...LIKELY ABRUPTLY ENDING RAINS AS IT DOES SO.
MAY SEE SOME LAKE SHOWERS ATTEMPT TO FIRE FAR NORTHERN LAKE MICHIGAN
TOWARDS MORNING WHERE MOISTURE WILL REMAIN DEEPER AND POST-COLD
FRONT CAA REGIME ONCE AGAIN DROPS H8 READINGS TO JUST BELOW 0C.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 335 AM EDT SUN OCT 20 2013
CLASSIC LATE AUTUMN WX WILL REMAIN IN PLACE FOR THE UPCOMING
WEEK...A BIT AHEAD OF SCHEDULE. PLENTY OF UPPER TROFFING WILL REMAIN
IN PLACE IN CENTRAL CANADA AND ADJOINING PARTS OF THE STATES. THE
LOWEST HEIGHTS WILL BE OVERHEAD MONDAY EVENING...AS AN UPPER LOW
CROSSES EASTERN SUPERIOR. HOWEVER...HEIGHT RECOVERY AFTER THAT LOW
EJECTS TO THE NE WILL BE ANEMIC. THAT WILL MAINTAIN MIXED PRECIP AS
A SIGNIFICANT FORECAST CONCERN...ESPECIALLY DURING THE LATE NIGHT/
EARLY MORNING HOURS. PRECIP TRENDS ARE THE MAIN CONCERN.
MONDAY...500MB LOW MOVES FROM INL TO MQT. 999MB SURFACE LOW OVER
EASTERN SUPERIOR WILL LIFT NE TO SSW OF JAMES BAY...WITH A NEW LOW
SPINNING UP ALONG A SECONDARY COLD FRONT IN CENTRAL SUPERIOR DURING
THE AFTERNOON. THE BACK EDGE OF THE WARM CONVEYOR BELT WILL BE ABOUT
TO EXIT NE LOWER MI AT 12Z...WITH DRIER MID LEVEL AIR IN THE PROCESS
OF POURING INTO NORTHERN LOWER. HOWEVER...OVERLAKE INSTABILITY WILL
BE INCREASING CONSIDERABLY AS COLDER LOW LEVEL AIR POURS IN. 850MB
TEMPS OVER NORTHERN LAKE MI WILL NEAR -6C BY 18Z...-8C BY 00Z.
MEANWHILE...EASTERN UPPER WILL REMAIN ON THE SOUTHERN PERIPHERY OF
THE DEEPER WRAPAROUND MOISTURE.
COULD STILL BE SOME FRONTAL SHRA IN FAR EASTERN SECTIONS TO START
THE MORNING. SCT SHRA WILL GET GOING IN WSW-FLOW AREAS (ESPECIALLY
FROM LEELANAU NORTHWARD) DURING THE MORNING...AS WELL AS IN EASTERN
UPPER. THESE COULD BECOME MORE NUMEROUS IN THE AFTERNOON...AS
INSTABILITY INCREASES (DELTA T/S IN THE LOWER 20S) AND THE CORE OF
THE DRY SLOT MOVES EAST. 1000-850MB WINDS WILL VEER TO THE WEST
DURING THE AFTERNOON...WITH INVERSION HEIGHTS A REASONABLY HEALTHY
6-7K FT. WILL INTRODUCE A SMALL CHANCE FOR A MIX VERY LATE IN THE
DAY IN THE INTERIOR OF EASTERN UPPER...WHERE THE SURFACE-BASED
MELTING LAYER IS NARROWING BELOW 1K FT.
MAX TEMPS IN THE 40S (TO LOWER 50S NE LOWER) AND EARLY...WITH
FALLING TEMPS IN THE PM. BRISK TO WINDY...ESPECIALLY NEAR LAKE MI.
MON NIGHT/TUESDAY...UPPER LOW WILL GRADUALLY LIFT OUT TOWARD JAMES
BAY...THOUGH WITH A SUBSTANTIAL SHORTWAVE ROUNDING IT/S SOUTHERN
FLANK LATE MONDAY NIGHT. THAT WILL DRIVE THE SECONDARY FRONT INTO
EASTERN UPPER MI LATE MONDAY NIGHT...AND ACROSS THE REST OF THE
FORECAST AREA ON TUESDAY. 1000-850MB WINDS WILL BRIEFLY BACK MORE
WSW AGAIN JUST AHEAD OF THIS TROF...ALLOWING THE INITIAL 850MB
THERMAL TROF TO MOVE EAST AND BOOSTING 850MB TEMPS TO -5C. WINDS
RAPIDLY VEER NW BEHIND THE TROF...AND COLD ADVECTION RESUMES. AFTER
CONTINUED LOW-END-ISH LAKE EFFECT MONDAY EVENING (THOUGH WITH MORE
SNOW MIXING IN AS DIURNAL HEATING IS LOST)...PRECIP WILL
SUBSTANTIALLY RAMP UP OVERNIGHT AS THE SECONDARY FRONT AND SHARP
1000-850MB CONVERGENCE ARRIVES. SLUSHY ACCUMS UP TO AN INCH SEEM A
DISTINCT POSSIBILITY MONDAY NIGHT NEAR GLR/BOYNE CITY/MANCELONA...
AND IN WESTERN CHIP. TUESDAY WILL SEE A WOBBLY NW FLOW...BUT WITH
MID-LEVEL DRYING/SUBSIDENCE AS THE VORT LOBE MOVES EAST. SOME LAKE
EFFECT WILL CONTINUE...ESPECIALLY IN THE MORNING...WITH DISRUPTIVE
DIURNAL HEATING DISORGANIZING THINGS IN THE PM. SOME SLOPPY LIGHT
ACCUMS ARE AGAIN POSSIBLE IN THE MOST FAVORED AREAS OF BOTH
PENINSULAS IN THE MORNING.
MIN TEMPS WITHIN A FEW DEGREES OF 30F. MAX TEMPS NEAR 40F TO THE MID
40S. AND IT WILL REMAIN BRISK TO WINDY.
REST OF THE FORECAST...FEW CHANGES NEEDED...AS COLD AND SHOWERY WX
WILL PERSIST AS CURRENTLY FORECAST. NEW ECMWF IS FLAT-OUT COLD
STRAIGHT THRU 240HRS. (PROBABLY BEST FOR MOTHER NATURE TO GET THIS
OUT OF HER SYSTEM NOW.)
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 657 AM EDT SUN OCT 20 2013
SCT/NMRS LAKE ENHANCED RAIN SHOWERS WILL CONTINUE TO IMPACT NRN
LWR MICHIGAN TAF SITES THRU SUNDAY NIGHT THANKS TO DEEP CYCLONIC
FLOW...COLD AIR ACTIVATING THE LAKES AND AMPLE LOW LEVEL MOISTURE.
OVERALL...CIGS WILL REMAIN LOW VFR...BUT MAY BRIEFLY DROP TO HIGH
MVFR WITHIN SOME OF THE HEAVIER SHOWER ACTIVITY...ESPECIALLY
TONIGHT. WESTERLY WINDS UNDER 10 KTS TONIGHT WILL SHIFT TO THE
S/SW ON SUNDAY AHEAD OF DEEPENING LOW PRESSURE SLIDING INTO THE
UPPER MISSISSIPPI VALLEY. LLWS TONIGHT AT ALL TAF SITES FOR PART
OF TONIGHT.
&&
.MARINE...
ISSUED AT 335 AM EDT SUN OCT 20 2013
RELATIVELY LIGHT WINDS THIS MORNING GIVES WAY TO
INCREASINGLY GUSTY SOUTH FLOW LATER THIS AFTERNOON...AND ESPECIALLY
TONIGHT...AS LOW PRESSURE INTENSIFIES AND PUSHES INTO EASTERN LAKE
SUPERIOR BY MONDAY MORNING. TIGHTENING PRESSURE GRADIENT AND ONSET
OF IMPRESSIVE SURGE OF CAA WILL LEAD TO VERY GUSTY WEST TO SOUTHWEST
WINDS DURING THE DAY MONDAY...WITH THE STRONGEST WINDS EXPECTED OVER
NORTHERN LAKE MICHIGAN. GALE FORCE WIND GUSTS APPEAR INCREASINGLY
LIKELY...RESULTING IN AN UPGRADE TO INHERITED NORTHERN LAKE MICHIGAN
GALE WATCH TO A WARNING. IN ADDITION...WIND GUST MAY REACH GALE
FORCE ACROSS WHITEFISH BAY AND THE ST. MARYS RIVER LATER MONDAY
MORNING THROUGH THE AFTERNOON. CONFIDENCE NOT HIGH ENOUGH TO WARRANT
A GALE WARNING...BUT ENOUGH CONCERN TO HOIST A GALE WATCH FOR THESE
AREAS. ADDITIONAL SCA/S WILL LIKELY BE NEEDED FOR OTHER NEARSHORE
ZONES...BUT WILL FOCUS ON GALE CONDITIONS AND PUNT ADVISORY
ISSUANCES TO FUTURE FORECAST SHIFTS. WELCOME TO FALL ON THE GREAT
LAKES!
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...GALE WARNING FROM 5 AM MONDAY TO 11 AM EDT TUESDAY FOR LHZ345.
LM...GALE WARNING FROM 5 AM MONDAY TO 11 AM EDT TUESDAY FOR LMZ341-
342-344>346.
LS...GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR LSZ321-
322.
&&
$$
UPDATE...BA
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...JZ
MARINE...MB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
734 AM EDT SUN OCT 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 510 AM EDT SUN OCT 20 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE OFF THE WEST COAST AND
A BROAD MID/UPPER LEVEL TROUGH ACROSS THE CNTRL AND ERN CONUS. ONE
UPSTREAM SHORTWAVE TROUGH WAS LOCATED OVER THE DAKOTAS WHILE ANOTHER
STRONGER PV ANOMALY WAS DROPPING TO THE SSE THROUGH CNTRL MANITOBA.
290K ISENTROPIC LIFT AHEAD OF A SFC LOW OVER THE CNTRL DAKOTAS
SUPPORTED AREAS OF RAIN OVER THE ERN DAKOTAS INTO WRN MN. 850 MB
TEMPS AROUND -4C HELPED TO MAINTAIN A LAKE INDUCED TROUGH OVER LAKE
SUPERIOR IN THE LIGHT WIND REGIME. ISOLD LAKE EFFECT -SHRA LINGERED
INTO NW UPPER MI AND ERN LAKE SUPERIOR.
THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE SHORTWAVES AND
SFC LOW MOVING INTO THE WRN GREAT LAKES. AS THE SFC LOW TRACKS FROM
WRN MN SUNDAY MORNING TO THE SE END OF LAKE SUPERIOR EARLY MON
MORNING...DEEP LAYER QVECTOR CONV AND 285K-295K ISENTROPIC LIFT WILL
SUPPORT AN AREA OF PCPN MOVING INTO SW UPPER MI SUN AFTERNOON AND
ACROSS THE CWA SUN NIGHT. PCPN AMOUNTS IN THE 0.25 TO 0.50 INCH
RANGE ARE EXPECTED. MODEL FCST SOUNDINGS...AND WET-BULB ZERO HEIGHTS
SUPPORT THE POTENTIAL FOR A SOME SNOW ACCUMULATION OVER THE HIGHER
TERRAIN OF THE WEST HALF OF UPPER MI. WITH ONLY LIGHT TO MODERATE
SNOWFALL RATES EXPECTED...AND RELATIVELY LOW SNOW/WATER RATIO VALUES
BELOW 10/1...ANY SNOW ACCUMULATION SHOULD GENERALLY REMAIN AT OR
BELOW 2 INCHES. THERE MAY ALSO BE SOME ADDITIONAL LAKE ENHANCED SNOW
INTO NW UPPER MI LATE AS WNW WINDS STRENGTHEN BEHIND THE LOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 337 AM EDT SUN OCT 20 2013
AN ACTIVE WEATHER PATTERN IS IN STORE FOR THE UPPER GREAT LAKES
REGION FOR THE UPCOMING WORK WEEK. THE UPPER TROUGH THAT IS
AFFECTING THE UPPER GREAT LAKES WILL BE RE-ENFORCED BY A SHORTWAVE
CURRENTLY DROPPING SOUTH OVER LAKE WINNIPEG. THIS WAVE WILL CATCH
UP WITH THE SURFACE LOW AND SHORTWAVE IN SOUTHERN MINNESOTA
(CURRENTLY IN WESTERN NORTH DAKOTA) AND INTENSIFY THE LOW TONIGHT
AS THE SHORTWAVES PHASE...CAUSING THE LOW TO LIFT NORTHEAST AND
OVER EASTERN LAKE SUPERIOR BY 12Z MONDAY. MODELS SEEM TO BE COMING
INTO BETTER AGREEMENT ON THE TRACK/INTENSITY OF THE LOW AS IT MOVES
NORTH FROM EASTERN LAKE SUPERIOR ON MONDAY...WHILE LEAVING A
SURFACE TROUGH BACK OVER THE LAKE THROUGH MONDAY NIGHT.
EXPECT THE INITIAL SURGE OF PRECIPITATION THAT MOVES THROUGH SUNDAY
AFTERNOON/NIGHT TO BE PUSHING NORTHEAST OF UPPER MICHIGAN.
THUS...WITH COLD AIR SURGING EAST ACROSS UPPER MICHIGAN UNDER THE
GUSTY WESTERLY FLOW...EXPECT THE MAIN WEATHER TO START MONDAY TO BE
WESTERLY WIND LAKE ENHANCED PRECIPITATION. THIS IS DUE TO 850MB
TEMPS FALLING TO -8C OVER WESTERN UPPER MICHIGAN BY 18Z MONDAY.
WILL HIGHLIGHT THE HIGHEST POPS OVER THE HIGHER TERRAIN FROM THE
KEWEENAW THROUGH THE GOGEBIC RANGE AND ALSO OVER THE HURON
MOUNTAINS. WESTERLY WINDS LOOK TO BACK SLIGHTLY IN THE AFTERNOON
AHEAD OF TROUGH DROPPING SOUTH ACROSS WESTERN LAKE SUPERIOR DURING
THE LATE AFTERNOON. THIS MAY CAUSE THE BEST PRECIPITATION TO BE
FOCUSED MORE OVER THE KEWEENAW DURING THE AFTERNOON. THEREFORE...DID
OPT TO TRIM POP/QPF AMOUNTS OVER GOGEBIC/ONTONAGON COUNTIES SOME
DURING THE AFTERNOON HOURS. SINCE WETBULB ZERO VALUES FALL OVER THE
WEST AS THE COLD AIR SURGES EAST ACROSS THE U.P. EXPECT PRECIP TO
FALL AS SNOW OVER THE WEST...BUT COULD MIX WITH RAIN AT TIMES NEAR
LAKE SUPERIOR. SNOWFALL AMOUNTS DURING THE MORNING AND MOST OF THE
AFTERNOON SHOULD BE LIGHT...WITH LOCATIONS SEEING AMOUNTS UNDER AN
INCH. OVER THE REST OF UPPER MICHIGAN DURING THIS PERIOD...EXPECT
BREEZY WESTERLY WINDS AND CLOUDY CONDITIONS...BUT LITTLE TO NO
PRECIPITATION IS EXPECTED. THE BEST OPPORTUNITY WOULD BE OVER THE
EAST RIGHT ALONG THE LAKE SUPERIOR/MICHIGAN SHORELINES AS LAKE
ENHANCED PRECIPITATION WILL TRY TO PARALLEL THOSE AREAS.
THEN TOWARDS SUNSET...THE SURFACE TROUGH WILL DROP SOUTH ONTO THE
WESTERN U.P. SHORELINE AND BRING AN ENHANCED AREA OF CONVERGENCE
AND PRECIPITATION. EXPECT THERE TO BE MODERATE TO HEAVY
PRECIPITATION AS THIS TROUGH SLIDES THROUGH THE WESTERN U.P. DURING
THE EVENING HOURS AND THEN THROUGH CENTRAL UPPER MICHIGAN DURING
THE OVERNIGHT HOURS. 850MB TEMPS WILL ACTUALLY WARM A COUPLE
DEGREES BEHIND THE TROUGH...BUT THE DEEP MOISTURE AND CYCLONIC
FLOW ON THE BACK SIDE OF THE SURFACE AND 850MB LOW...ALONG WITH
UPSLOPE WINDS...WILL SUPPORT LAKE ENHANCED PRECIPITATION THROUGH A
GOOD PORTION OF THE NIGHT OVER THE WESTERN CWA AND INTO TUESDAY
MORNING OVER THE NORTH CENTRAL CWA. THE PRECIPITATION DURING THIS
PERIOD SHOULD FALL AS SNOW EXCEPT FOR LOCATIONS RIGHT ALONG THE
LAKE SUPERIOR SHORELINE WHERE THE NORTH-NORTHWEST WINDS WOULD
PRODUCE SOME HEAT TRANSFER FROM THE LAKE AND LEAD TO SOME RAIN/SNOW
MIX. AS FOR RATIOS/AMOUNTS...THINKING THE SNOW RATIOS WILL BE AROUND
OR JUST BELOW 10-1 WITH THE BEST FORCING BEING BELOW THE DGZ AND
SNOW FLAKES FALLING FROM ALOFT CLUMPING TOGETHER AS THEY REACH THE
STRONG UPWARD MOTION NEAR THE SURFACE. AS FOR QPF AMOUNTS...HPC
INDICATES NAM IS THE COLDER SOLUTION IN THE MID LEVELS (BY AROUND
2C) BEHIND THE LOW...WHICH MAY BE PART OF THE REASON IT IS MUCH
HIGHER ON QPF AMOUNTS WITH THE LAKE ENHANCED SNOW BEHIND THE
TROUGH. SINCE THE HIGHER RESOLUTION OF THE NAM AND 4KM
NEST PICK UP THE TERRAIN ENHANCEMENT...DID BLEND THAT
WITH THE PREFERRED WARMER AND COARSER MODELS FOR QPF
MONDAY AFTERNOON THROUGH TUESDAY MORNING. THIS CREATES
24HR VALUES OF 0.5-0.75IN FROM IRONWOOD THROUGH THE
KEWEENAW AND ALSO OVER THE WESTERN SIDE OF THE HURON
MOUNTAINS. AT 10-1 SLR VALUE...SNOWFALL AMOUNTS IN THE 3-6 INCH
RANGE SEEM REASONABLE IN THOSE AREAS AFTER FACTORING SOME
MELTING INITIALLY ON MONDAY WHEN THE SNOWFALL RATES ARE LIGHTER.
THAT SEEMS TO FIT IN WITH OUR ADVISORY CRITERIA AND WILL LIKELY END
UP JUST UNDER THE 6INCH IN 12HR MARK FOR WARNINGS. CIPS TOP ANALOGS
(BASED OFF THE SLIGHTLY COLDER NAM SOLUTION) SHOW MEAN SNOWFALL
AMOUNTS OF 4-8 INCHES OF A 72HR PERIOD AND PROBABILITIES OF SEEING
6IN OF SNOW AROUND 60 PERCENT. THINK THE FORECAST MATCHES UP PRETTY
WELL WITH THAT IDEA (ALONG WITH HPC GUIDANCE) AND WILL CONTINUE TO
HIGHLIGHT THIS MEASUREABLE SNOW EVENT IN THE HWO AND ISSUE AN SPS TO
HIGHTEN THE AWARENESS.
SURFACE TROUGH WILL QUICKLY SHIFT EAST OF THE AREA ON
TUESDAY...AS AN AREA OF HIGH PRESSURE SLIDES INTO THE NORTHERN
PLAINS. EXPECT A DIMINISHING PRECIPITATION TREND FROM WEST TO EAST
ACROSS THE CWA WITH THE DEEPER MOISTURE DEPARTING. THROUGH THE REST
OF THE WEEK...EXPECT NORTHWESTERLY FLOW TO BE IN PLACE AS THE LOW
SITS OVER QUEBEC AND A SERIES OF HIGHS DROP SOUTHEAST THROUGH THE
NORTHERN PLAINS. 850MB TEMPS THROUGH THE REST OF THE PERIOD SHOULD
BE RIGHT AROUND -8C WHICH LEADS TO PLENTY OF LAKE INSTABILITY. WILL
CONTINUE TO HIGHLIGHT CHANCE POPS OR HIGHER IN THE TRADITIONAL
NORTHWEST FLOW LOCATIONS THROUGH FRIDAY. HIGHEST POPS AND POTENTIAL
FOR ACCUMULATION SNOWFALL WILL BE OVER THE EASTERN U.P. WITH THE
LONGER FETCH AND CLOSER PROXIMITY TO THE BETTER MOISTURE UNDER THE
UPPER LOW. THERE WILL BE A COUPLE BRIEF PERIODS WHERE THE LAKE
EFFECT PRECIPITATION WILL PICKUP AS WEAK SHORTWAVES AND BETTER
MOISTURE SWEEP THROUGH. CIPS TOP ANALOGS FOR THE MID WEEK PERIOD
UNDER PERSISTENT LAKE EFFECT SNOWFALL SHOWS PROBABILITY FOR 4IN OF
SNOW IN A 72HR PERIOD BEING AROUND 60 PERCENT IN THE TRADITIONAL
FAVORED NORTHWEST FLOW LOCATIONS. BEING THAT IS OVER A 3 DAY
PERIOD...THING THOSE VALUES ARE REASONABLE WITH LIGHT ACCUMULATIONS
OCCURRING THROUGH THE END OF THE WORK WEEK.
THE UPPER TROUGHS INFLUENCE ON THE UPPER GREAT LAKES LOOKS TO
WEAKEN THIS WEEKEND AS IT SHIFTS EAST INTO THE NEW ENGLAND STATES.
BUT ANOTHER SHORTWAVE ROUNDING THE UPPER RIDGE OVER THE ROCKIES
WILL TRY TO MOVE INTO THE AREA FOR THE SECOND HALF OF THE WEEKEND.
WILL JUST GO WITH A GENERAL CONSENSUS AND HAVE CHANCE POPS WITH
TEMPERATURES REMAINING BELOW NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 733 AM EDT SUN OCT 20 2013
ARRIVAL OF A WEAK HIGH PRESSURE RIDGE SHOULD BRING VFR CONDITIONS TO
ALL THE SITES FOR MUCH OF THE DAY TODAY...BUT THICKER CLOUDS AND
RAIN WILL ARRIVE SW TO NE SUN AFTERNOON AND EVENING AHEAD OF LOW
PRES MOVING THROUGH THE UPPER LAKES. EXPECT CONDITIONS TO
DETERIORATE TO MVFR AT ALL 3 SITES AND EVEN IFR AT IWD UNDER STEADY
RA WITH UPSLOPE NE WIND. SAW AND CMX ARE ALSO EXPECTED TO DROP TO
IFR WITH THE PERSISTENT LIGHT RAIN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 510 AM EDT SUN OCT 20 2013
LOW PRESSURE MOVEING OUT OF THE DAKOTAS WILL BEGIN TO INTENSIFY OVER
THE UPPER MISSISSIPPI VALLEY TODAY AND THEN MOVE THROUGH THE UPPER
GREAT LAKES TONIGHT AND MONDAY. AS THIS OCCURS...WINDS WILL
STRENGTHEN ACROSS THE LAKE...FIRST OUT OF THE SOUTH TO SOUTHEAST
AHEAD OF THE LOW THIS EVENING AND THEN OUT OF THE WEST BEHIND THE
LOW LATE TONIGHT INTO MONDAY. THERE STILL ARE SOME DIFFERENCES
IN THE EXACT TRACK AND STRENGTH OF THE LOW AS IT MOVES ACROSS LAKE
SUPERIOR ON MONDAY...SO WIND SPEED/DIRECTIONS ARE STILL UNCERTAIN.
AT THIS TIME...IT APPEARS THE STRONGEST WINDS WILL BE BEHIND THE LOW
ON MONDAY AND MONDAY NIGHT...WHEN WEST GALES TO 35-40KTS VEERING TO
THE NORTH ARE EXPECTED. ONCE THE LOW DEPARTS THE AREA...EXPECT
NORTHWESTERLY WINDS UP TO 25KTS TO REMAIN OVER LAKE SUPERIOR INTO
WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH TUESDAY AFTERNOON FOR
LSZ265>267.
GALE WATCH FROM MONDAY EVENING THROUGH TUESDAY MORNING FOR
LSZ264.
GALE WATCH FROM MONDAY MORNING THROUGH TUESDAY MORNING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
700 AM EDT SUN OCT 20 2013
.SYNOPSIS...
ISSUED AT 335 AM EDT SUN OCT 20 2013
COOL WEATHER WITH PERIODS OF LAKE EFFECT SHOWERS WILL CONTINUE
INTO NEXT WEEK...AS A BROAD TROUGH OF LOW PRESSURE REMAINS OVER THE
GREAT LAKES. EVEN COLDER AIR WILL ENGULF THE GREAT LAKES AND UPPER
MIDWEST BY MONDAY...AS ANOTHER WEAK STORM SYSTEM EXITS NORTHEAST
INTO QUEBEC EARLY IN THE WORK WEEK. TEMPERATURES MAY GET COLD ENOUGH
TO BRING THE FIRST SNOWFALL OF THE SEASON...ESPECIALLY TO INTERIOR
SECTIONS OF EASTERN UPPER AND NORTHERN LOWER MICHIGAN.
&&
.UPDATE...
ISSUED AT 657 AM EDT SUN OCT 20 2013
CLOUDS HAVE OPENED UP CONSIDERABLY IN PARTS OF NE LOWER AND EASTERN
UPPER MI. THIS WILL TEND TO SELF-DESTRUCT WITH HEATING TODAY...THE
SUB-800MB AIRMASS REMAINS ON THE MOIST SIDE. SOME ADJUSTMENTS MADE
TO EARLY-MORNING CLOUD COVER.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 335 AM EDT SUN OCT 20 2013
MUCH DISCUSSED DEEP TROUGHING CONTINUES TO DOMINATE GREAT LAKES
WEATHER AT THIS EARLY HOUR...DOWNSTREAM OF EQUALLY IMPRESSIVE
RIDGING POCKING UP AND BEYOND THE NORTHWEST TERRITORIES. SUBTLE WAVE
TRAVERSING WITHIN THIS FLOW...NOW IN THE PROCESS OF FURTHER
DEAMPLIFYING AND CUTTING ACROSS THE NORTHERN LAKES. THIS...COMBINED
WITH STILL MORE THAN SUPPORTIVE OVER-WATER INSTABILITY (H8
TEMPERATURES RIGHT AROUND -2C PER HIGH RES RAP AND 00Z SOUNDING
ANALYSIS)...CONTINUES TO KICK OFF LAKE ENHANCED RAIN SHOWERS OFF
NORTHERN LAKE MICHIGAN (EVEN HAD SOME LEGITIMATE SNOWFLAKES MIX IN
WITH THE RAIN HERE ON TOP OF THE HILL). OTHERWISE...A RATHER QUIET
AND TOUCH CHILLY NIGHT...WITH CURRENT READINGS MAINLY IN THE 30S AND
LOWER 40S. MAIN SYSTEM OF INTEREST THROUGH THE SHORT TERM IS WELL
DEFINED SHORTWAVE/VORT LOBE DROPPING STRAIGHT SOUTH THROUGH CENTRAL
MANITOBA. THIS SYSTEM WILL DRUM UP A RATHER RESPECTABLE AREA OF LOW
PRESSURE TONIGHT AS IT DROPS INTO MINNESOTA. GOOD MID LEVEL SUPPORT
AND LOW LEVEL ENERGY SUPPLIED BY WARM LAKE WATERS WILL HELP DEEPEN
THIS SURFACE LOW AS IT MOVES UP INTO EASTERN LAKE SUPERIOR BY MONDAY
MORNING. THIS SYSTEM WILL BRING MORE WIDESPREAD RAINS HEADING INTO
TONIGHT...AND PERHAPS A GALE EVENT ON PARTS OF THE BIG WATERS. SHORT
TERM FORECAST CONCERNS CENTER ON ADDRESSING THE IMPACTS OF THIS
SYSTEM.
BY AND LARGE...A RATHER NON-EVENTFUL WEATHER DAY EXPECTED TODAY.
CURRENT OVERHEAD WAVE WILL HAVE EXITED STAGE RIGHT BY
SUNRISE...LEAVING PURE LAKE PROCESSES FOR ANY ADDITIONAL SHOWER
DEVELOPMENT THROUGH MID AFTERNOON. EXPECT THERE WILL BE SOME ONGOING
TO START THE DAY...ESPECIALLY ALONG THE NORTHWEST LOWER COASTLINE
WHERE WIND CONVERGENCE WILL BE MAXIMIZED. LAKE PROCESSES WILL BE A
DOWNWARD ONE HEADING THROUGH THE DAY AS WINDS BACK SOUTHERLY AND
WEAK MID LEVEL RIDGING BUILDS OVERHEAD. ATTENTION LATE THIS
AFTERNOON INTO THE OVERNIGHT TURNS TO STRONG WAA RESPONSE AHEAD OF
EARLIER MENTIONED DEEPENING SURFACE LOW. RATHER IMPRESSIVE
ISENTROPIC UPGLIDE SIGNATURE VIA FORCED ASCENT ON NOSE OF 40+ KNOT
LOW LEVEL JET...WITH WELL OVER HALF INCH PWATS ALSO SURGING NORTH
INTO THE AREA WITH THIS JET. ABOVE LOOKS TO KICK OFF A RATHER LARGE
AREA OF RAIN...WHICH WILL SPREAD RAPIDLY NORTHEAST ACROSS OUR AREA
LATE THIS AFTERNOON INTO THIS EVENING. PER FULL 00Z GUIDANCE
ANALYSIS...MAY AMP UP RAIN CHANCES SOME SOUTHWEST THIRD OF THE AREA
AFTER 21Z TODAY...WITH INHERITED CATEGORICAL WORDING INTO THIS
EVENING LOOKING GREAT. DRY SLOT PUNCHES IN FROM THE SOUTHWEST
THROUGH THE OVERNIGHT...LIKELY ABRUPTLY ENDING RAINS AS IT DOES SO.
MAY SEE SOME LAKE SHOWERS ATTEMPT TO FIRE FAR NORTHERN LAKE MICHIGAN
TOWARDS MORNING WHERE MOISTURE WILL REMAIN DEEPER AND POST-COLD
FRONT CAA REGIME ONCE AGAIN DROPS H8 READINGS TO JUST BELOW 0C.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 335 AM EDT SUN OCT 20 2013
CLASSIC LATE AUTUMN WX WILL REMAIN IN PLACE FOR THE UPCOMING
WEEK...A BIT AHEAD OF SCHEDULE. PLENTY OF UPPER TROFFING WILL REMAIN
IN PLACE IN CENTRAL CANADA AND ADJOINING PARTS OF THE STATES. THE
LOWEST HEIGHTS WILL BE OVERHEAD MONDAY EVENING...AS AN UPPER LOW
CROSSES EASTERN SUPERIOR. HOWEVER...HEIGHT RECOVERY AFTER THAT LOW
EJECTS TO THE NE WILL BE ANEMIC. THAT WILL MAINTAIN MIXED PRECIP AS
A SIGNIFICANT FORECAST CONCERN...ESPECIALLY DURING THE LATE NIGHT/
EARLY MORNING HOURS. PRECIP TRENDS ARE THE MAIN CONCERN.
MONDAY...500MB LOW MOVES FROM INL TO MQT. 999MB SURFACE LOW OVER
EASTERN SUPERIOR WILL LIFT NE TO SSW OF JAMES BAY...WITH A NEW LOW
SPINNING UP ALONG A SECONDARY COLD FRONT IN CENTRAL SUPERIOR DURING
THE AFTERNOON. THE BACK EDGE OF THE WARM CONVEYOR BELT WILL BE ABOUT
TO EXIT NE LOWER MI AT 12Z...WITH DRIER MID LEVEL AIR IN THE PROCESS
OF POURING INTO NORTHERN LOWER. HOWEVER...OVERLAKE INSTABILITY WILL
BE INCREASING CONSIDERABLY AS COLDER LOW LEVEL AIR POURS IN. 850MB
TEMPS OVER NORTHERN LAKE MI WILL NEAR -6C BY 18Z...-8C BY 00Z.
MEANWHILE...EASTERN UPPER WILL REMAIN ON THE SOUTHERN PERIPHERY OF
THE DEEPER WRAPAROUND MOISTURE.
COULD STILL BE SOME FRONTAL SHRA IN FAR EASTERN SECTIONS TO START
THE MORNING. SCT SHRA WILL GET GOING IN WSW-FLOW AREAS (ESPECIALLY
FROM LEELANAU NORTHWARD) DURING THE MORNING...AS WELL AS IN EASTERN
UPPER. THESE COULD BECOME MORE NUMEROUS IN THE AFTERNOON...AS
INSTABILITY INCREASES (DELTA T/S IN THE LOWER 20S) AND THE CORE OF
THE DRY SLOT MOVES EAST. 1000-850MB WINDS WILL VEER TO THE WEST
DURING THE AFTERNOON...WITH INVERSION HEIGHTS A REASONABLY HEALTHY
6-7K FT. WILL INTRODUCE A SMALL CHANCE FOR A MIX VERY LATE IN THE
DAY IN THE INTERIOR OF EASTERN UPPER...WHERE THE SURFACE-BASED
MELTING LAYER IS NARROWING BELOW 1K FT.
MAX TEMPS IN THE 40S (TO LOWER 50S NE LOWER) AND EARLY...WITH
FALLING TEMPS IN THE PM. BRISK TO WINDY...ESPECIALLY NEAR LAKE MI.
MON NIGHT/TUESDAY...UPPER LOW WILL GRADUALLY LIFT OUT TOWARD JAMES
BAY...THOUGH WITH A SUBSTANTIAL SHORTWAVE ROUNDING IT/S SOUTHERN
FLANK LATE MONDAY NIGHT. THAT WILL DRIVE THE SECONDARY FRONT INTO
EASTERN UPPER MI LATE MONDAY NIGHT...AND ACROSS THE REST OF THE
FORECAST AREA ON TUESDAY. 1000-850MB WINDS WILL BRIEFLY BACK MORE
WSW AGAIN JUST AHEAD OF THIS TROF...ALLOWING THE INITIAL 850MB
THERMAL TROF TO MOVE EAST AND BOOSTING 850MB TEMPS TO -5C. WINDS
RAPIDLY VEER NW BEHIND THE TROF...AND COLD ADVECTION RESUMES. AFTER
CONTINUED LOW-END-ISH LAKE EFFECT MONDAY EVENING (THOUGH WITH MORE
SNOW MIXING IN AS DIURNAL HEATING IS LOST)...PRECIP WILL
SUBSTANTIALLY RAMP UP OVERNIGHT AS THE SECONDARY FRONT AND SHARP
1000-850MB CONVERGENCE ARRIVES. SLUSHY ACCUMS UP TO AN INCH SEEM A
DISTINCT POSSIBILITY MONDAY NIGHT NEAR GLR/BOYNE CITY/MANCELONA...
AND IN WESTERN CHIP. TUESDAY WILL SEE A WOBBLY NW FLOW...BUT WITH
MID-LEVEL DRYING/SUBSIDENCE AS THE VORT LOBE MOVES EAST. SOME LAKE
EFFECT WILL CONTINUE...ESPECIALLY IN THE MORNING...WITH DISRUPTIVE
DIURNAL HEATING DISORGANIZING THINGS IN THE PM. SOME SLOPPY LIGHT
ACCUMS ARE AGAIN POSSIBLE IN THE MOST FAVORED AREAS OF BOTH
PENINSULAS IN THE MORNING.
MIN TEMPS WITHIN A FEW DEGREES OF 30F. MAX TEMPS NEAR 40F TO THE MID
40S. AND IT WILL REMAIN BRISK TO WINDY.
REST OF THE FORECAST...FEW CHANGES NEEDED...AS COLD AND SHOWERY WX
WILL PERSIST AS CURRENTLY FORECAST. NEW ECMWF IS FLAT-OUT COLD
STRAIGHT THRU 240HRS. (PROBABLY BEST FOR MOTHER NATURE TO GET THIS
OUT OF HER SYSTEM NOW.)
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 657 AM EDT SUN OCT 20 2013
SCT/NMRS LAKE ENHANCED RAIN SHOWERS WILL CONTINUE TO IMPACT NRN
LWR MICHIGAN TAF SITES THRU SUNDAY NIGHT THANKS TO DEEP CYCLONIC
FLOW...COLD AIR ACTIVATING THE LAKES AND AMPLE LOW LEVEL MOISTURE.
OVERALL...CIGS WILL REMAIN LOW VFR...BUT MAY BRIEFLY DROP TO HIGH
MVFR WITHIN SOME OF THE HEAVIER SHOWER ACTIVITY...ESPECIALLY
TONIGHT. WESTERLY WINDS UNDER 10 KTS TONIGHT WILL SHIFT TO THE
S/SW ON SUNDAY AHEAD OF DEEPENING LOW PRESSURE SLIDING INTO THE
UPPER MISSISSIPPI VALLEY. LLWS TONIGHT AT ALL TAF SITES FOR PART
OF TONIGHT.
&&
.MARINE...
ISSUED AT 335 AM EDT SUN OCT 20 2013
RELATIVELY LIGHT WINDS THIS MORNING GIVES WAY TO
INCREASINGLY GUSTY SOUTH FLOW LATER THIS AFTERNOON...AND ESPECIALLY
TONIGHT...AS LOW PRESSURE INTENSIFIES AND PUSHES INTO EASTERN LAKE
SUPERIOR BY MONDAY MORNING. TIGHTENING PRESSURE GRADIENT AND ONSET
OF IMPRESSIVE SURGE OF CAA WILL LEAD TO VERY GUSTY WEST TO SOUTHWEST
WINDS DURING THE DAY MONDAY...WITH THE STRONGEST WINDS EXPECTED OVER
NORTHERN LAKE MICHIGAN. GALE FORCE WIND GUSTS APPEAR INCREASINGLY
LIKELY...RESULTING IN AN UPGRADE TO INHERITED NORTHERN LAKE MICHIGAN
GALE WATCH TO A WARNING. IN ADDITION...WIND GUST MAY REACH GALE
FORCE ACROSS WHITEFISH BAY AND THE ST. MARYS RIVER LATER MONDAY
MORNING THROUGH THE AFTERNOON. CONFIDENCE NOT HIGH ENOUGH TO WARRANT
A GALE WARNING...BUT ENOUGH CONCERN TO HOIST A GALE WATCH FOR THESE
AREAS. ADDITIONAL SCA/S WILL LIKELY BE NEEDED FOR OTHER NEARSHORE
ZONES...BUT WILL FOCUS ON GALE CONDITIONS AND PUNT ADVISORY
ISSUANCES TO FUTURE FORECAST SHIFTS. WELCOME TO FALL ON THE GREAT
LAKES!
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...GALE WARNING FROM 5 AM MONDAY TO 11 AM EDT TUESDAY FOR LHZ345.
LM...GALE WARNING FROM 5 AM MONDAY TO 11 AM EDT TUESDAY FOR LMZ341-
342-344>346.
LS...GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR LSZ321-
322.
&&
$$
UPDATE...JZ
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...JZ
MARINE...MB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
654 AM CDT SUN OCT 20 2013
.SHORT/LONG TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 433 AM CDT SUN OCT 20 2013
PERSISTENT NORTHWEST FLOW WILL REMAIN IN TACT THROUGHOUT THE
PERIOD...LEADING TO BELOW NORMAL TEMPERATURES AND PERIODIC CHANCES
FOR LIGHT PRECIP. GIVEN THE COLD AIR EXPECTED TO BE IN PLACE...WILL
SEE THE POTENTIAL FOR FROZEN PRECIP CARRY ON THROUGH NEXT WEEK.
ARGUABLY THE MOST INTRIGUING FEATURE IN THE EXTENDED IS THE CLIPPER
SYSTEM CURRENTLY APPROACHING THE UPPER MIDWEST. THE LATEST HIRES
MODELS PORTRAY MORE OF A SOUTHERLY TRACK...SO HAVE BROUGHT THE
HIGHEST POPS AND QPF SOUTH TO REFLECT THIS TREND. HOWEVER...BUFR
FORECAST SOUNDINGS OFF THE RAP ONLY HAVE AROUND AN INCH OF SNOW AT
MORA...AND BRAINERD...WITH LESS AT ALEXANDRIA AND ST CLOUD. THE NAM
IS CONTINUES TO ADVERTISE 4 INCHES AT MORA...BUT THIS IS LIKELY
OVERDONE CONSIDERING THAT ACCORDING TO THE NAM AS OF 5AM 1-2 INCHES
SHOULD HAVE ALREADY FALLEN AT FARGO..AND THEY HAVE YET TO RECEIVE
ANY SNOW. THE MAIN REASON FOR THE SLOW CHANGEOVER SEEMS TO BE THE
LACK OF STRONG FGEN AND FOCUSED VERTICAL MOTION IN THE WAA
REGIME...RATHER GRADUAL ISENTROPIC ASCENT WAS THE DRIVING FORCE
BEHIND THE PRECIP. THROUGHOUT THE MORNING HOURS...THE NAM DOES
INCREASE THE FGEN FORCING...WHILE THE RAP IS WEAKER. AFTER WEEDING
THROUGH THE DIFFERENT SCENARIOS...DO NOT HAVE THE CONFIDENCE IN ANY
SNOWFALL AMOUNTS EXCEEDING 3 INCHES DESPITE THE SOUTHERLY SHIFT IN
QPF. RATHER SHOULD SEE A MODEST BAND OF SNOW TRACK NORTH OF
I-94...WITH PERHAPS AN INCH OR 2 ON GRASSY SURFACES THIS
MORNING...BEFORE TRANSITIONING TO MORE OF RAIN/SNOW OR EVEN ALL RAIN
MIX LATER THIS AFTERNOON AS 1)THE BOUNDARY LAYER WARMS...AND 2) WE
LOSE THE DEEP SATURATION AND TRANSITION TO MORE OF LIGHT
RAIN/DRIZZLE SCENARIO.
BRISK NORTHWEST WINDS WILL FOLLOW ONCE THIS SYSTEM MOVES EASTWARD AS
COOLER AIR AS EVIDENT BY THE -7 TO -10C H850 TEMPS ADVECT ACROSS THE
REGION SUNDAY NIGHT INTO MONDAY. THE NORTHWEST FLOW WILL PERSIST
ACROSS THE REGION...WITH A FEW SHORTWAVES TRACKING DOWN THE POLEWARD
SIDE OF THE JET. THESE WILL INDUCE LOW LEVEL CIRCULATIONS...THE NEXT
OF WHICH IS EXPECTED TO TRACK SOUTHWEST OF THE CWA ALONG THE
MISSOURI RIVER VALLEY MONDAY NIGHT INTO TUESDAY. COLD AIR WILL AGAIN
BE REINFORCED BEHIND THIS SYSTEM...WILL NO WARM UP POTENTIAL IN
SIGHT UNTIL PERHAPS THE END OF THE WEEK AS ANOTHER WAVE MOVES ACROSS
THE REGION. DEPENDING ON THE TRACK OF THIS SYSTEM...THE UPPER
MIDWEST COULD SEE ONE DAY OF WARMER TEMPERATURES...BUT THE GUIDANCE
IS CONSISTENT THAT THIS WILL BE SHORT LIVED AS ANOTHER ARCTIC
AIRMASS WILL FOLLOW BEHIND THIS PASSING WAVE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 621 AM CDT SUN OCT 20 2013
A COMPLEX AND MESSY TAF PERIOD IS AHEAD AS A CLIPPER SYSTEM DIVES
SOUTHEAST ACROSS SOUTHERN MINNESOTA TODAY. PRECIPITATION CONTINUES
TO MOVE EAST AND IS NOW APPROACHING KMSP. IT SHOULD BEGIN AS
SNOW...CHANGE QUICKLY TO RAIN WITH MAYBE SOME SNOW MIXED IN AT THE
TAF SITES FOR AN HOUR OR SO THIS MORNING AS WELL AS SOME
DRIZZLE. DONT REALLY HAVE STRONG UPWARD VERTICAL MOTION SO DO NOT
EXPECT DYNAMIC COOLING OF ANY SORT TO FOUL UP THE PRECIPITATION
TYPE. BOUNDARY LAYER TEMPS WARM THIS MORNING WITH WARM AIR
ADVECTION IN PLACE AND THERMAL PROFILES SUPPORT A QUICK CHANGE
FROM SNOW TO RAIN. QUICK PEEK AT THE KMPX SOUNDING SHOWS A LOT
MORE MOISTURE ABOVE 700MB AS COMPARED TO LAST EVENINGS SOUNDING.
HIGH RES MODELS INDICATE DRY AIR TO WORK IN FROM THE SOUTHWEST
AFTER 20Z AND AS A RESULT PRECIP SHOULD END AROUND 20-21Z IN MOST
AREAS...MAYBE SOME DRIZZLE CONTINUING AT AXN/STC AND OVER INTO
WESTERN WISCONSIN. GUIDANCE WANTS TO RAISE CIGS TOO MUCH FOR THE
EVENING AND OVERNIGHT HOURS. MUCH DRIER AIR COMES IN ALOFT HOWEVER
THE LOWEST 4000 FEET OF THE ATMOSPHERE REMAIN QUITE MOIST SO WILL
HOLD ON TO MVRF CIGS THROUGH THE PERIOD. WINDS WILL BE QUITE GUSTY
AT AXN/RWF THIS AFTERNOON AND EARLY EVENING.
KMSP...ONSET OF PRECIP WILL OCCUR BY 12Z AND THAT SHOULD BE
SNOW PELLETS...SNOW AND OR DRIZZLE. AFTER 13Z WILL SEE A MIX AT
TIMES OF RAIN AND SNOW AND ALL RAIN BY 14Z AS THE BOUNDARY LEVEL
WARMS SLIGHTLY. WARM AIR ADVECTION PATTERN FEATURES A SLOW UPWARD
ASCENT OF AIR HENCE THE OPPORTUNITIES FOR DRIZZLE OR LIGHT RAIN.
BIGGEST UNCERTAINTY WILL BE CIGS TODAY THROUGH MONDAY MORNING. WAS
OPTIMISTIC FOR TODAY AND PESSIMISTIC FOR THE OVERNIGHT HOURS AS
COMPARED TO GUIDANCE. HOWEVER COULD EASILY SEE LOWER CIGS THIS
MORNING AND AFTERNOON AND THAT WILL HAVE TO BE WATCHED CLOSELY AS
THE WARM FRONT WILL BE JUST NORTH OF THE METRO AND MSP WILL BE
SOMEWHERE BETWEEN THE IFR CIGS TO THE NORTH AND VFR OR MVFR CIGS
TO THE SOUTH IN THE WARMER AIR.
/OUTLOOK FOR KMSP/
MON...MVFR IN AM...VFR IN AFTERNOON. WINDS NW AT 10-15KT.
TUE...VFR WITH MVFR CIGS POSSIBLE EARLY. WINDS NW AT 5-10 KTS.
WED...MVFR CIGS POSSIBLE. WINDS W AT 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...JRB
AVIATION...DRL
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
716 AM CDT SUN OCT 20 2013
.UPDATE...
DENSE FOG HAS FORMED OVER A FEW OF THE NORTHERN COUNTIES AND IN
SPOTTY LOCATIONS NEAR JANESVILLE AND ALONG THE WISCONSIN RIVER
VALLEY. HRRR HAS FOG LIFTING AROUND 10 AM. GIVEN SUNRISE IS COMING
AND MARGINAL LENGTH OF ABOUT 3 HOURS...DECIDED TO GO WITH SPECIAL
WEATHER STATEMENT RATHER THAN ZERO LEAD TIME DENSE FOG ADVISORY.
TEMPERATURES ARE RIGHT AROUND FREEZING SO SOME RIMING AND SLIPPERY
SPOTS POSSIBLE.
MEANWHILE FROST AND FROZEN DEW DID FORM AT THE BUZZER WITH THE FOG
HELPING THINGS OUT. WILL LET FROST ADVISORY EXPIRE ON TIME.
&&
.PREV DISCUSSION... /ISSUED 336 AM CDT SUN OCT 20 2013/
TODAY...FORECAST CONFIDENCE IS HIGH.
STRONG UPSTREAM SHORTWAVE TROUGH DIGGING INTO LONG WAVE TROUGH
POSITION TODAY. THIS ALLOWS FLOW TO TURN FROM NORTHWEST TO
WESTERLY DURING THE DAY ALOFT.
SURFACE LOW OF CLIPPER LIKE SYSTEM CURRENTLY EAST OF BIS ND
EXPECTED TO MOVE FROM SOUTHEAST SOUTH DAKOTA TO SOUTHERN MINNESOTA
THIS MORNING...THEN MOVE INTO CENTRAL WISCONSIN THIS AFTERNOON.
DECENT BAROCLINIC ZONE WITH THIS FEATURE WITH STRONG WARM
ADVECTION SPREADING ACROSS WISCONSIN DURING THE DAY. THE STRONGEST
WARM ADVECTION AND DEEPEST MOISTURE IS SHOWN TO CLIP THE FAR NORTH
DURING THE DAY...SO MUCH OF THE DAY MAY BE DRY IN THE SOUTH.
THE LACK OF RAIN IN THE SOUTH AND STRONG WARM ADVECTION REGIME
COULD RESULT IN TEMPERATURES WELL INTO THE 50S AND PERHAPS EVEN
LOWER 60S ALONG THE ILLINOIS BORDER.
STRONG MOISTURE TRANSPORT DEVELOPS JUST AHEAD OF SURFACE COLD
FRONT IN THE LATE AFTERNOON...WITH MODELS SHOWING RAPID INCREASE
IN MOISTURE IN THE SOUTHEAST. PRECIPITABLE WATERS RISE TO ABOUT
0.75" AND THE MODELS SHOW ADDITIONAL BANDS OF PRECIPITATION
FORMING AT THE BUZZER BEFORE THE FRONT MOVES THROUGH IN THE
EVENING. TIMING OF THIS WILL BE CRITICAL AS IT WILL RUN ITS COURSE
BETWEEN ABOUT 21-03Z...MAKING POP FORECASTS SOMEWHAT TRICKY.
TONIGHT...FORECAST CONFIDENCE IS HIGH.
DEEP CLOSED LOW DIGS INTO NORTHERN MINNESOTA WITH -34C 500 MB COLD
CORE. THIS RESULTS IN 70 METER HEIGHT FALLS CENTERED NEAR LAKE
SUPERIOR. SURFACE LOW TURNS TO THE NORTHEAST AND DEEPENS AS IT
MOVES ACROSS THE UP INTO EASTERN LAKE SUPERIOR. THIS USHERS IN
SIGNIFICANT COLD ADVECTION...SUBSIDENCE...AND DEEP DRYING.
LINGERING RAIN IN THE EVENING SHOULD QUICKLY MOVE EAST.
MONDAY THROUGH TUESDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
SHORT TERM MODELS IN DECENT AGREEMENT WITH FEATURES DURING THIS
PERIOD...THOUGH THEY DO SHOW SOME DIFFERENCES. DEEP LOW PRESSURE
SHIFTS FROM EASTERN LAKE SUPERIOR INTO ONTARIO CANADA
MONDAY...THEN BRINGS A SURFACE TROUGH SOUTHEAST THROUGH NORTHEAST
WISCONSIN MONDAY NIGHT.
DEEP 500MB LOW SHIFTS FROM NORTHERN/NORTHEAST MINNESOTA TO EASTERN
LAKE SUPERIOR MONDAY...THEN TO THE EAST MONDAY NIGHT.
GFS/ECMWF/CANADIAN BRING STRONG VORTICITY MAXIMUM EASTWARD BUT
JUST NORTH OF THE AREA MONDAY...WITH SHEARED VORTICITY IN THE AREA
MONDAY NIGHT. THE NAM BRINGS THESE FEATURES SOUTHEAST THROUGH THE
AREA LATER MONDAY AND MONDAY NIGHT. SIDED MORE WITH
GFS/ECMWF/CANADIAN MODELS DURING THIS TIME.
AREA FORECAST SOUNDINGS SHOWING DIURNAL CUMULUS CLOUDS
MONDAY...THEN CLEARING OUT SOMEWHAT MONDAY NIGHT. THERE MAY BE
SOME MIDDLE TO HIGH CLOUDS MONDAY NIGHT...THOUGH CONFIDENCE IS LOW
AT THIS TIME. TIGHT PRESSURE GRADIENT MONDAY WILL ALLOW FOR GUSTY
WEST WINDS...WITH GRADIENT REMAINING FAIRLY TIGHT MONDAY NIGHT.
COOL HIGHS IN THE 40S ARE EXPECTED MONDAY PER 925MB TEMPERATURE
FIELDS AND COLD AIR ADVECTION REGIME. THEY SHOULD DROP LOW ENOUGH
MONDAY NIGHT FOR UPPER 20S TO LOWER 30S ACROSS THE ENTIRE
AREA...ALLOWING FOR A KILLING FREEZE ACROSS THE AREA. DAY SHIFT
SHOULD CONSIDER A FREEZE WATCH FOR MONDAY NIGHT...AND WILL
CONTINUE TO HIGHLIGHT IN HAZARDOUS WEATHER OUTLOOK.
GFS HAS TRENDED A BIT SOUTHWARD WITH THE PASSING LOW PRESSURE
SYSTEM TUESDAY INTO TUESDAY EVENING. 00Z ECMWF ALSO IS SHOWING A
SIMILAR LOW TRACK...WITH QPF JUST CLIPPING THE SOUTHWEST COUNTIES
TUESDAY. THEY BOTH BRING A SHORTWAVE TROUGH THROUGH THE AREA AT
00Z WEDNESDAY. THE NAM/CANADIAN MODELS KEEP THE LOW AND ASSOCIATED
QPF TO THE SOUTHWEST OF THE AREA. ADDED LOW POPS IN THE FAR
SOUTHWEST COUNTIES TUESDAY GIVEN THE GFS/ECMWF LOW TRACKS.
KEPT THE DRY FORECAST GOING ELSEWHERE TUESDAY INTO TUESDAY NIGHT.
KEPT ANY POPS WITH POSSIBLE LAKE EFFECT PRECIPITATION OVER THE
NEARSHORE WATERS ONLY TUESDAY NIGHT...AS LOW LEVEL WINDS LOOK TO
REMAIN PARALLEL TO SHORE AT BEST.
COOL HIGHS IN THE 40S LINGER WITH DIURNAL CUMULUS TUESDAY...WITH
ANOTHER COLD NIGHT/KILLING FREEZE TUESDAY NIGHT IN THE UPPER
20S TO LOWER 30S.
WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE IS MEDIUM.
ECMWF/GFS SHOWING SIMILAR GENERAL TRENDS DURING THIS PERIOD...WITH
SOME DIFFERENCES IN SPECIFIC FEATURES. THEY SHOW A GENERAL
NORTHWEST FLOW AT 500MB CONTINUING ACROSS THE REGION WEDNESDAY
INTO FRIDAY...WITH SEVERAL SHEARED VORTICITY MAXIMA PASSING
THROUGH.
HIGH PRESSURE SYSTEMS SHIFT SOUTHEAST ACROSS THE NORTHERN AND
CENTRAL PLAINS DURING THIS TIME...MAINTAINING THE COLD AIRMASS
OVER THE REGION. GFS FORECAST SOUNDINGS SHOWING SOME DIURNAL
CUMULUS DEVELOPMENT EACH DAY...WITH LIMITED MOISTURE.
THUS...PERIOD SHOULD BE FAIRLY DRY.
GFS THEN BRINGS LOW PRESSURE SOUTHEAST ACROSS THE REGION FRIDAY
NIGHT AND SATURDAY...WITH A STRONG SHORTWAVE TROUGH PASSAGE. THE
ECMWF KEEPS THE AREA DRY FRIDAY NIGHT...WITH THE SHORTWAVE TROUGH
PASSING THROUGH THE REGION SATURDAY. THE SURFACE LOW TAKES A
SIMILAR PATH TO THE GFS...BUT IS ABOUT 12 TO 18 HOURS SLOWER. BOTH
SYSTEMS BRING QPF TO THE AREA. GIVEN SOME UNCERTAINTY HERE...USED
CONSENSUS POPS AND TEMPERATURES FOR THIS PERIOD.
AVIATION/12Z TAFS/...
PATCHY FOG MAY IMPACT THE TAF SITES BRIEFLY THIS MORNING WITH
LIGHT WINDS UNDER WEAK SURFACE HIGH.
MUCH OF THE RAIN WILL STAY NORTH OF THE TAF SITES THIS AFTERNOON
AND WILL BE DEVELOPING OVER SOUTHERN WISCONSIN AHEAD OF THE COLD
FRONT LATE IN THE AFTERNOON AND EARLY IN THE EVENING. THERE IS
SUFFICIENT LOW LEVEL DRY AIR TO KEEP CEILINGS IN VFR RANGE IF IT
DOES RAIN.
WINDS WILL INCREASE FROM THE SOUTH TODAY AND THEN TURN WESTERLY
TONIGHT AND BECOME GUSTY IN THE WAKE OF THE COLD FRONT.
MARINE...
STRONG PRESSURE FALLS IN THE LATE AFTERNOON AND EVENING AHEAD OF
THE SURFACE LOW WILL USHER IN GUSTY SOUTH TO SOUTHWEST WINDS THAT
WILL RAPIDLY INCREASE LATE IN THE AFTERNOON. THE WINDS WILL TURN
TO THE SOUTHWEST AND THEN WEST TONIGHT AND THEN NORTHWEST MONDAY
AND TUESDAY. THE COLD FRONT WILL CROSS LAKE MICHIGAN LATER
TONIGHT.
IT WILL BE UNSTABLE AS THE COLD AIR POURS IN TONIGHT SO EXPECT
GUSTY WINDS AND HIGH WAVES IN THE COASTAL WATERS REQUIRING THE
ISSUANCE OF SMALL CRAFT ADVISORY FROM TONIGHT INTO TUESDAY
MORNING. GALE FORCE WINDS ARE EXPECTED AND MUCH HIGHER WAVES
TOWARD OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR WIZ046-047-051-
052-056>060-062>072.
LM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM CDT TUESDAY
FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...CRAVEN
MONDAY THROUGH SATURDAY...WOOD
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
234 PM MDT SUN OCT 20 2013
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 233 PM MDT SUN OCT 20 2013
IN NW FLOW ALOFT THE INITIAL VORTICITY MAXIMUM HAS PASSED TO THE
SE OF THE STEAMBOAT-VAIL LINE PRODUCING ENHANCEMENT EAST OF VAIL
PASS THIS EARLY AFTERNOON. SNOTELS SHOW 2 INCHES IN THE MTNS EAST
OF STEAMBOAT SPRINGS WITH HIGHER AMOUNTS IN THE PARK RANGE NEAR
THE WYOMING BORDER. SNOW ACCUMULATION LEVEL THIS AFTERNOON IS
AROUND 9KFT THERE. SOME LESS ORGANIZED ENERGY WILL ROLL OVER THE
ELKHEADS-PARK-GORE RANGES THIS AFTERNOON BUT THIS FORCING ENDS BY
SUNSET. LITTLE EXTRA ACCUMULATION IS EXPECTED EXCEPT PERHAPS IN
THE HIGHEST ELEVATIONS OF THE ZIRKEL WILDERNESS. THE 18Z RAP AND
HRRR END SHOWERS BY 6PM BUT THE NAM HOLDS ONTO SOME LIGHT
OROGRAPHIC SNOW ON NORTH-FACING SLOPES INTO THE EVENING. ALL AGREE
ITS ALL DONE BY MIDNIGHT. THEREFORE HAVE CUT BACK POPS FOR
TONIGHT.
SOME LOW-MID CLOUDS WILL LINGER OVERNIGHT MAINLY EAST OF A LINE
FROM CRAIG SOUTH TO MONARCH PASS. OTHERWISE PARTIALLY CLEARING
SKIES WILL KEEP TEMPERATURES BELOW NORMAL TONIGHT AND MONDAY.
WITH THE PASSING OF THESE FINAL DISTURBANCES THIS EVENING THE
WEST COAST RIDGE RELAXES INTO THE INTERMOUNTAIN WEST. BENIGN AND
DRY NW FLOW CONTINUES THROUGH MONDAY NIGHT AND BEYOND.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 233 PM MDT SUN OCT 20 2013
DRY WITH A GRADUAL WARMING TREND AS THE LARGE-SCALE PATTERN CHANGES
LITTLE. A BLOCKING UPPER RIDGE NEAR THE WEST COAST DRIFTS OVER THE
GREAT BASIN BY MIDWEEK BEFORE RETREATING BACK WESTWARD...WHILE A
LARGE TROUGH REMAINS OVER THE CENTRAL AND EASTERN PART OF THE
COUNTRY. NORTHWEST FLOW ON TUESDAY BECOMES WEST TO SOUTHWEST
WEDNESDAY-THURSDAY AS A WEAK WAVE UNDERCUTS THE RIDGE AND CROSSES
THE SOUTHERN GREAT BASIN...SWITCHING BACK TO NORTHWEST FRIDAY AS THE
WAVE PASSES BY TO OUR SOUTH. THIS WILL BRING SOME CLOUDS TO CENTRAL
AND SOUTHERN PARTS OF THE FORECAST AREA BUT LITTLE OR NO
PRECIPITATION...AND WILL KEEP THE FORECAST DRY. DAYTIME TEMPERATURES
WILL BE NEAR TO A LITTLE ABOVE NORMAL WHILE THE NIGHTS AVERAGE NEAR
NORMAL.
AN UPPER LOW IS EXPECTED TO PINCH OFF FROM THE NORTHERN JET
STREAM OVER THE NERN PACIFIC OCEAN AND GRADUALLY SETTLE OFF THE CA
COAST AND UNDERNEATH THE RIDGE BY LATE FRIDAY. MODELS OFTEN HAVE
DIFFICULTY HANDLING THESE CUT-OFF LOWS...AND THE GFS AND ECMWF
SHOW DIFFERENT SOLUTIONS BY NEXT MONDAY. BOTH INDICATE DRY WEATHER
STILL NEXT WEEKEND SO WILL CONTINUE WITH THAT FOR NOW...BUT
CONFIDENCE IS LOWERING BY SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 233 PM MDT SUN OCT 20 2013
EXPECT AREAS OF MOUNTAIN OBSCURATION OVER THE
ELKHEAD...PARK...GORE...AND PORTIONS OF THE ELK RANGES THIS
AFTERNOON. THERE IS A SLIGHT CHANCE THAT KCAG...KEEO...
KHDN...KSBS...AND KEGE WILL EXPERIENCE BRIEF MVFR CIGS IN LIGHT
SHOWERS THROUGH 03Z THEN VFR CONDITIONS WILL DOMINATE.
ELSEWHERE...EXPECT VFR CONDITIONS TO PERSIST THROUGH THE NEXT 24
HOURS AND BEYOND.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JOE
LONG TERM...JAD
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1111 AM MDT SUN OCT 20 2013
.UPDATE...
ISSUED AT 1110 AM MDT SUN OCT 20 2013
SNOW SHOWERS HAVE WORKED INTO NW COLORADO THIS EARLY MORNING.
SPOTTERS BETWEEN STEAMBOAT SPRINGS AND CLARK REPORT SNOW
FLURRIES. SNOTEL SITES HAVE NOT RESPONDED YET AND ARE HOVERING
NEAR 32 DEGREES. THE MORNING MODELS ARE CONSISTENT WITH PREVIOUS
RUNS PRODUCING 1-3 INCHES IN THE ELKHEAD AND ZIRKEL MOUNTAINS WITH
LESS INTO THE PARK AND FLATTOPS MOUNTAINS...WITH SOME LIGHT SNOW
INTO THE ELK MTNS THROUGH THE AFTERNOON INCLUDING INDEPENDENCE AND
COTTONWOOD PASSES. CRAIG MAY SEE A FLURRY...AND PUT A SLIGHT
CHANCE OF SHOWERS IN THE I-70 CORRIDOR EAST OF GLENWOOD SPRINGS.
THE BEST FORCING PASSES OVER THE ELKHEADS THIS AFTERNOON BUT COLD
ADVECTIVE NW FLOW MAY PRODUCE LIGHT SNOW ACROSS THE MENTIONED
NORTHERN CO MTNS THROUGH THE EVENING HOURS WHEN THE -22C COLD CORE
PASSES. SOME CLOUDS WILL LINGER OVERNIGHT IN NW CO... OTHERWISE
CLEARING SKIES WILL KEEP TEMPERATURES BELOW NORMAL TONIGHT AND
MONDAY.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 331 AM MDT SUN OCT 20 2013
A FAST MOVING SHORTWAVE IN THE NORTHWESTERLIES WILL IMPACT THE
NORTHERN AND PORTIONS OF THE CENTRAL MOUNTAINS TODAY. HIGH
CLOUDS AHEAD OF THE SYSTEM BEGAN SWEEPING OVER THE NORTH LAST
EVENING. EXPECT SHOWERS WILL HOLD OFF UNTIL AFTER 12Z PER
CONSENSUS OF GFS40...NAM12...RAP13...AND HRRR MODELS. THEREFORE
...PARED BACK POPS EARLY THIS MORNING.
AS THE SHORTWAVE SWEEPS SOUTHEASTWARD ACROSS SOUTHWEST WYOMING
SHOWERS WILL DEVELOP OVER THE ELKHEADS AROUND SUNRISE. THIS
ACTIVITY WILL SPREAD TO THE PARK AND GORE RANGES...FLAT TOPS...AND
ELK MOUNTAINS AS THE AXIS OF THE SHORTWAVE SWEEPS INTO NORTHWEST
COLORADO THIS AFTERNOON. UPWARD FORCING...OROGRAPHIC LIFT AND
SUFFICIENTLY STEEP LAPSE RATES WILL BRING ACCUMULATING SNOW TO
THE NORTHERN AND CENTRAL MOUNTAINS. SNOW LEVELS WILL SETTLE AROUND
MOUNTAIN BASES IN THE NORTH AND NEAR 8500 FEET IN THE CENTRAL
MOUNTAINS THIS AFTERNOON. MOISTURE LACKING WITH THIS SYSTEM SO
WILL CONTINUE WITH 1 TO 2 INCH ACCUMULATIONS IN THE MOUNTAIN AREAS
MENTIONED PREVIOUSLY. LOWER ELEVATIONS EAST OF KCAG-KASE LINE
COULD SEE BRIEF SHOWERS BUT CHANCES NOT GREAT GIVEN LIMITED
MOISTURE.
ELSEWHERE...EXPECT DRY WEATHER TO CONTINUE WITH PARTLY SUNNY TO
MOSTLY SUNNY SKIES AND HIGHS CONTINUING TO RUN A BIT COOL FOR THIS
TIME OF YEAR. A PUSH OF COOLER AIR COMBINED WITH CLOUDS AND
SHOWERS WILL DECREASE TEMPERATURES AROUND 5 DEGREES ACROSS NORTH-
CENTRAL COLORADO THIS AFTERNOON.
SNOW GRADUALLY TAPERS OFF OVERNIGHT FROM THE NORTH AS THE BULK OF
PRECIPITATION HANGS OVER THE DIVIDE THROUGH THE MORNING HOURS
MONDAY WITH FAVORABLE WIND DIRECTION FOR LINGERING LIGHT SNOW
STRETCHING ALONG THE CENTRAL MOUNTAIN CORRIDOR. SNOW LEVEL WILL
DECREASE TO AROUND 6500 FEET BY EARLY MONDAY MORNING WITH THE
ADVECTION OF COLD NORTHERLY AIR. 1 TO 3 INCHES OF SNOW IS EXPECTED
OVER THE NORTHERN MOUNTAINS AND PORTIONS OF THE CENTRAL MOUNTAINS
THROUGH EARLY MONDAY MORNING...WITH THE POTENTIAL FOR LOCALLY
HIGHER AMOUNTS. THE SHORTWAVE IS FORECAST TO PROGRESS TO THE VERY
EASTERN PART OF CENTRAL COLORADO BY NOON MONDAY...SO ALL
PRECIPITATION IS EXPECTED TO HAVE CEASED OVER THE DIVIDE WITH
BRISK NORTHERLY AIR FILTERING IN BEHIND IN AN AREA OF SUBSIDENCE.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 331 AM MDT SUN OCT 20 2013
CLEAR SKIES AND SLIGHTLY BELOW NORMAL TEMPERATURES WILL REIGN AS
HIGH PRESSURE BUILDS INTO THE REGION MONDAY NIGHT. WINDS WILL
REMAIN LIGHT...ALLOWING INVERSIONS TO DEVELOP IN VALLEY BOTTOMS
OVERNIGHT AND KEEP LOW TEMPERATURES BELOW NORMAL.
A WEAK MID-LEVEL LOW PRESSURE TROUGH OVER THE WEST COAST UNDERCUTS
THE RIDGE...MOVING EASTWARD ACROSS THE GREAT BASIN AND DESERT
SOUTHWEST TUESDAY NIGHT THROUGH THURSDAY. MODELS TAKE THE BULK OF
THE ENERGY ASSOCIATED WITH THIS FEATURE SOUTH OF THE FORECAST AREA
FROM THURSDAY NIGHT INTO FRIDAY BEFORE PUSHING IT ONTO THE
SOUTHERN PLAINS SATURDAY. LATEST ECMWF FARTHER SOUTH WITH THIS
FEATURE THAN YESTERDAY/S 00Z RUN WHICH LIMITS CHANCES FOR ANY
SENSIBLE WEATHER OVER THE SAN JUANS FRIDAY. LESS ENERGETIC GFS
SHOWED LITTLE CHANGE AND ALSO DRY FRIDAY. AS A RESULT...KEPT
MENTION OF PRECIPITATION CHANCES OUT OF THE FORECAST THROUGHOUT
THE ENTIRE EXTENDED PERIOD. EXPECT TEMPERATURES WILL HOVER NEAR
NORMAL THROUGH THE COMING WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1110 AM MDT SUN OCT 20 2013
IN NW FLOW ALOFT A WEAK PASSING DISTURBANCE WILL BRUSH NORTH-
CENTRAL COLORADO THROUGH THIS AFTERNOON AND THIS EVENING. SNOW HAS
DEVELOPED EAST OF A LINE FROM KCAG SE TO KASE AND WILL INCREASE IN
INTENSITY THIS AFTERNOON. EXPECT AREAS OF MOUNTAIN OBSCURATION
OVER THE ELKHEAD...PARK...GORE...AND PORTIONS OF THE ELK RANGES
THIS AFTERNOON. THERE IS A SLIGHT CHANCE THAT KCAG...KEEO...
KHDN...KSBS...AND KEGE WILL EXPERIENCE BRIEF MVFR CIGS IN LIGHT
SHOWERS THROUGH 06Z. ELSEWHERE...EXPECT VFR CONDITIONS TO PERSIST
THROUGH THE NEXT 24 HOURS AND BEYOND.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JOE
SHORT TERM...NL/JAM
LONG TERM...JAM/NL
AVIATION...NL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
342 PM EDT SUN OCT 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 510 AM EDT SUN OCT 20 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE OFF THE WEST COAST AND
A BROAD MID/UPPER LEVEL TROUGH ACROSS THE CNTRL AND ERN CONUS. ONE
UPSTREAM SHORTWAVE TROUGH WAS LOCATED OVER THE DAKOTAS WHILE ANOTHER
STRONGER PV ANOMALY WAS DROPPING TO THE SSE THROUGH CNTRL MANITOBA.
290K ISENTROPIC LIFT AHEAD OF A SFC LOW OVER THE CNTRL DAKOTAS
SUPPORTED AREAS OF RAIN OVER THE ERN DAKOTAS INTO WRN MN. 850 MB
TEMPS AROUND -4C HELPED TO MAINTAIN A LAKE INDUCED TROUGH OVER LAKE
SUPERIOR IN THE LIGHT WIND REGIME. ISOLD LAKE EFFECT -SHRA LINGERED
INTO NW UPPER MI AND ERN LAKE SUPERIOR.
THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE SHORTWAVES AND
SFC LOW MOVING INTO THE WRN GREAT LAKES. AS THE SFC LOW TRACKS FROM
WRN MN SUNDAY MORNING TO THE SE END OF LAKE SUPERIOR EARLY MON
MORNING...DEEP LAYER QVECTOR CONV AND 285K-295K ISENTROPIC LIFT WILL
SUPPORT AN AREA OF PCPN MOVING INTO SW UPPER MI SUN AFTERNOON AND
ACROSS THE CWA SUN NIGHT. PCPN AMOUNTS IN THE 0.25 TO 0.50 INCH
RANGE ARE EXPECTED. MODEL FCST SOUNDINGS...AND WET-BULB ZERO HEIGHTS
SUPPORT THE POTENTIAL FOR A SOME SNOW ACCUMULATION OVER THE HIGHER
TERRAIN OF THE WEST HALF OF UPPER MI. WITH ONLY LIGHT TO MODERATE
SNOWFALL RATES EXPECTED...AND RELATIVELY LOW SNOW/WATER RATIO VALUES
BELOW 10/1...ANY SNOW ACCUMULATION SHOULD GENERALLY REMAIN AT OR
BELOW 2 INCHES. THERE MAY ALSO BE SOME ADDITIONAL LAKE ENHANCED SNOW
INTO NW UPPER MI LATE AS WNW WINDS STRENGTHEN BEHIND THE LOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 342 PM EDT SUN OCT 20 2013
MON NIGHT...MODELS SHOW THE ELONGATED SFC TROUGH FM LOW JUST SOUTH
OF JAMES BAY WILL BE SITUATED OVER NRN LAKE SUPERIOR ON MONDAY. AS
THE STRONG SHORTWAVE/CLOSED MID-UPR LVL LOW FM MANITOBA BEGINS TO
MOVE ACROSS LAKE SUPERIOR AND UPPER MI MON NIGHT THIS WILL PROPEL
THE SFC TROF ACROSS WRN LAKE SUPERIOR AND WRN UPR MI MON EVENING AND
ACROSS ERN LAKE SUPERIOR AND CENTRAL/ERN UPR MI LATE MON NIGHT. THE
TIMING OF THIS TROUGH WILL BE IMPORTANT AS WINDS WILL SHIFT FM
WESTERLY TO NNW AND BRING STRONGLY CONVERGENT CYCLONIC FLOW TO FOCUS
LAKE EFFECT SHOWERS INTO WESTERN UPPER MI MON EVENING AND ACROSS THE
REST OF THE NORTH HALF UPPER MI LATE MON NIGHT. 850 MB TEMPS AROUND
-6C OVER LAKE SUPERIOR ALONG WITH DEEP MOISTURE AND STRONG CYCLONIC
FLOW WILL RESULT IN PLENTY OF LAKE ENHANCED PCPN OVER THE NORTHERN
HALF OF THE UPPER MI MON NIGHT INTO TUE MORNING. MODEL SOUNDINGS
INDICATE THERE SHOULD BE ENOUGH LOW LEVEL COLD AIR FOR AT LEAST
SEVERAL INCHES OF WET ACCUMULATING SNOW OVER THE HIGHER TERRAIN OF
WEST HALF OF UPPER MI...ESPECIALLY WHERE UPSLOPE NW TO NNW FLOW
PREVAILS. CONFIDENCE IN SNOW AMOUNTS IS STILL ONLY AVERAGE GIVEN THE
MODEL DIFFERENCES WITH TIMING OF THE TROUGH AND SHIFT OF LOW LEVEL
WINDS. THE BEST CHANCE FOR SIGNIFICANT SNOW ACCUMULATIONS WILL BE
OVER THE HIGHER TERRAIN OF THE WEST FROM NEAR IRONWOOD TROUGH
ROCKLAND TO TWIN LAKES AND MOHAWK AND OVER THE HURON MOUNTAINS OF
BARAGA AND MARQUETTE COUNTIES. SOME ACCUMULATING SNOW WILL ALSO BE
LIKELY FROM THE HURON MOUNTAINS TO NEGAUNEE MON NIGHT.
AT THIS POINT...IT APPEARS THAT SNOW ACCUMULATION WILL STAY BELOW
WARNING CRITERIA FOR TWO MAIN REASONS. ONE...MODEL SNDGS SUGGEST THE
BEST DENDRITIC SNOW GROWTH LAYER WILL BE ABOVE THE BEST MODEL
OMEGA/LIFT WITH SYSTEM WHICH WILL LIKELY LIMIT SNOW/WATER RATIOS TO
AROUND 8/1. TWO...MODEL DEEP LAYER Q-VECT CONV INDICATES THAT THE
BEST ENHANCEMENT/SYNOPTIC SCALE FORCING FOR LAKE SNOW SHOWERS WILL
BE BEFORE THE PASSAGE OF THE TROUGH OR BEFORE THE WINDS SHIFT FROM W
TO NNW. I DON`T DOUBT THAT THERE COULD BE A QUICK INCH OR TWO OF
SNOW WITH GOOD CONVERGENCE AND A BAND OF HEAVIER SNOW RIGHT ALONG
THE TROUGH PASSAGE. BUT AFTER THE TROUGH PASSAGE...PURE LAKE EFFECT
WILL TAKE OVER...AND GIVEN THAT 850 MB TEMPS FALL AT BEST TO -7C
OVER WRN LAKE SUPERIOR EQUATING TO A LAKE DELTA-T OF 16C...WOULD
EXPECT NO MORE THAN UP TO 3 INCHES OF ADDITIONAL ACCUMULATION AT
BEST THROUGH TUE MORNING OVER FAVORED HIGHER TERRAIN LOCATIONS. FOR
THIS REASON WILL NOT ISSUE A WATCH BUT WILL CONTINUE TO HIGHLIGHT
SNOW ACCUMULATION IN A SPS.
TUE-FRI...WITH THE MEAN LONG WAVE TROUGH REMAINING OVER THE GREAT
LAKES AND ERN CONUS...NW FLOW AND A SERIES OF WEAK CLIPPER SHRTWVS
ARE EXPECTED TO MOVE THROUGH THE UPPER LAKES. THIS WILL BRING
PERIODS OF SNOW SHOWERS...MIXED WITH RAIN AT TIMES...THAT WILL BE
ENHANCED BY LAKE SUPERIOR AS 850 MB TEMPS CONTINUE TO FALL INTO THE
-8C TO -10C RANGE. LOCATIONS GENERALLY FAVORED BY NW FLOW WILL SEE
BEST CHANCE FOR PCPN. SOME ADDITIONAL ACCUMULATING SNOW IS POSSIBLE
AND AS IS TYPICAL IN EARLY SEASON LAKE EFFECT REGIMES...GRAUPEL WILL
LIKELY ALSO BE MIXED WITH ANY RAIN/SNOW SHOWERS. LAKE EFFECT PCPN
WILL DIMINISH BY FRIDAY AS UPPER TROUGH MOVES EAST AND RIDGING
BUILDS IN FM THE WEST.
NEXT WEEKEND...MODELS SHOW PLENTY OF VARIABILITY OUT TO DAYS 6 AND 7
OF THE FCST. ALL MODELS SHOW ANOTHER CLIPPER SHORTWAVE ROUNDING THE
WRN CONUS RIDGE AND DIVING INTO THE NRN PLAINS AND UPPER GREAT LAKES
REGION BUT TRACK AND TIMING OF SHORTWAVE IS UNCERTAIN AT THIS TIME.
FOR NOW WILL GO WITH A GENERAL CONSENSUS FCST AND INCLUDE CHC POPS
FOR RAIN/SNOW SHOWERS AND TEMPS REMAINING BLO NORMAL FOR NEXT
SAT-SUN. THE 00Z ECMWF ADVERTISES YET ANOTHER CLIPPER SHORTWAVE
MOVING IN FOR THE EARLY PART OF THE FOLLOWING WORK WEEK WHICH WOULD
USHER IN THE COLDEST AIRMASS YET OF THE SEASON WITH 850 MB TEMPS
FALLING AOB -12C. IF THIS SOLUTION HOLDS TRUE...THE LAST FEW DAYS OF
OCTOBER WILL FEATURE CONTINUED BELOW NORMAL TEMPS AND MORE LAKE
EFFECT PCPN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 242 PM EDT SUN OCT 20 2013
TIMING OF THE APPROACHING SNOW AND LOWER CEILINGS HAS BEEN VERY
TRICKY TODAY...MADE TRICKIER BY FOG/STRATUS THIS MORNING ACROSS THE
HIGHER ELEVATIONS OF THE W HALF OF UPPER MI. THIS MAINLY INFLUENCED
SAW...WHICH WAS RIGHT ON THE CLEARING LINE THANKS TO LIGHT DOWNSLOPE
WINDS MUCH OF THE MORNING. CEILINGS HAVE BEEN HOVERING BETWEEN HIGH
END MVFR AND VFR EARLY THIS AFTERNOON...WITH THE RAIN/SNOW LINE AND
MVFR TO IFR CEILINGS NEARING FROM N CENTRAL WI THIS AFTERNOON.
EXPECT DETERIORATING CONDITIONS AT ALL 3 SITES...WITH RAIN SLOWLY
MIXING WITH SNOW OVERNIGHT. THE MIX OF RAIN AND SNOW WILL LIKELY
CHANGE OVER TO ALL SNOW AT IWD SHORTLY BEFORE DAYBREAK AS COOLER AIR
RUSHES IN ON FAVORABLE W-NW WINDS. THE CHANGE OVER SHOULD TAKE A
COUPLE MORE HOURS AT CMX...WITH A LOW TEMP IN THE MID 30S OVERNIGHT.
STRONGER W WINDS WILL BE COMMON STARTING 09-15Z W TO E...WITH GUSTS
OF 25-30KTS /STRONGEST AT CMX/...AS CEILINGS SLOWLY IMPROVE AS THE
BULK OF THE MOISTURE EXITS AS THE SFC LOW PUSHES INTO E QUEBEC.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 510 AM EDT SUN OCT 20 2013
LOW PRESSURE MOVEING OUT OF THE DAKOTAS WILL BEGIN TO INTENSIFY OVER
THE UPPER MISSISSIPPI VALLEY TODAY AND THEN MOVE THROUGH THE UPPER
GREAT LAKES TONIGHT AND MONDAY. AS THIS OCCURS...WINDS WILL
STRENGTHEN ACROSS THE LAKE...FIRST OUT OF THE SOUTH TO SOUTHEAST
AHEAD OF THE LOW THIS EVENING AND THEN OUT OF THE WEST BEHIND THE
LOW LATE TONIGHT INTO MONDAY. THERE STILL ARE SOME DIFFERENCES
IN THE EXACT TRACK AND STRENGTH OF THE LOW AS IT MOVES ACROSS LAKE
SUPERIOR ON MONDAY...SO WIND SPEED/DIRECTIONS ARE STILL UNCERTAIN.
AT THIS TIME...IT APPEARS THE STRONGEST WINDS WILL BE BEHIND THE LOW
ON MONDAY AND MONDAY NIGHT...WHEN WEST GALES TO 35-40KTS VEERING TO
THE NORTH ARE EXPECTED. ONCE THE LOW DEPARTS THE AREA...EXPECT
NORTHWESTERLY WINDS UP TO 25KTS TO REMAIN OVER LAKE SUPERIOR INTO
WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH TUESDAY AFTERNOON FOR
LSZ265>267.
GALE WATCH FROM MONDAY EVENING THROUGH TUESDAY MORNING FOR
LSZ264.
GALE WATCH FROM MONDAY MORNING THROUGH TUESDAY MORNING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...KF
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
243 PM EDT SUN OCT 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 510 AM EDT SUN OCT 20 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE OFF THE WEST COAST AND
A BROAD MID/UPPER LEVEL TROUGH ACROSS THE CNTRL AND ERN CONUS. ONE
UPSTREAM SHORTWAVE TROUGH WAS LOCATED OVER THE DAKOTAS WHILE ANOTHER
STRONGER PV ANOMALY WAS DROPPING TO THE SSE THROUGH CNTRL MANITOBA.
290K ISENTROPIC LIFT AHEAD OF A SFC LOW OVER THE CNTRL DAKOTAS
SUPPORTED AREAS OF RAIN OVER THE ERN DAKOTAS INTO WRN MN. 850 MB
TEMPS AROUND -4C HELPED TO MAINTAIN A LAKE INDUCED TROUGH OVER LAKE
SUPERIOR IN THE LIGHT WIND REGIME. ISOLD LAKE EFFECT -SHRA LINGERED
INTO NW UPPER MI AND ERN LAKE SUPERIOR.
THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE SHORTWAVES AND
SFC LOW MOVING INTO THE WRN GREAT LAKES. AS THE SFC LOW TRACKS FROM
WRN MN SUNDAY MORNING TO THE SE END OF LAKE SUPERIOR EARLY MON
MORNING...DEEP LAYER QVECTOR CONV AND 285K-295K ISENTROPIC LIFT WILL
SUPPORT AN AREA OF PCPN MOVING INTO SW UPPER MI SUN AFTERNOON AND
ACROSS THE CWA SUN NIGHT. PCPN AMOUNTS IN THE 0.25 TO 0.50 INCH
RANGE ARE EXPECTED. MODEL FCST SOUNDINGS...AND WET-BULB ZERO HEIGHTS
SUPPORT THE POTENTIAL FOR A SOME SNOW ACCUMULATION OVER THE HIGHER
TERRAIN OF THE WEST HALF OF UPPER MI. WITH ONLY LIGHT TO MODERATE
SNOWFALL RATES EXPECTED...AND RELATIVELY LOW SNOW/WATER RATIO VALUES
BELOW 10/1...ANY SNOW ACCUMULATION SHOULD GENERALLY REMAIN AT OR
BELOW 2 INCHES. THERE MAY ALSO BE SOME ADDITIONAL LAKE ENHANCED SNOW
INTO NW UPPER MI LATE AS WNW WINDS STRENGTHEN BEHIND THE LOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 337 AM EDT SUN OCT 20 2013
AN ACTIVE WEATHER PATTERN IS IN STORE FOR THE UPPER GREAT LAKES
REGION FOR THE UPCOMING WORK WEEK. THE UPPER TROUGH THAT IS
AFFECTING THE UPPER GREAT LAKES WILL BE RE-ENFORCED BY A SHORTWAVE
CURRENTLY DROPPING SOUTH OVER LAKE WINNIPEG. THIS WAVE WILL CATCH
UP WITH THE SURFACE LOW AND SHORTWAVE IN SOUTHERN MINNESOTA
(CURRENTLY IN WESTERN NORTH DAKOTA) AND INTENSIFY THE LOW TONIGHT
AS THE SHORTWAVES PHASE...CAUSING THE LOW TO LIFT NORTHEAST AND
OVER EASTERN LAKE SUPERIOR BY 12Z MONDAY. MODELS SEEM TO BE COMING
INTO BETTER AGREEMENT ON THE TRACK/INTENSITY OF THE LOW AS IT MOVES
NORTH FROM EASTERN LAKE SUPERIOR ON MONDAY...WHILE LEAVING A
SURFACE TROUGH BACK OVER THE LAKE THROUGH MONDAY NIGHT.
EXPECT THE INITIAL SURGE OF PRECIPITATION THAT MOVES THROUGH SUNDAY
AFTERNOON/NIGHT TO BE PUSHING NORTHEAST OF UPPER MICHIGAN.
THUS...WITH COLD AIR SURGING EAST ACROSS UPPER MICHIGAN UNDER THE
GUSTY WESTERLY FLOW...EXPECT THE MAIN WEATHER TO START MONDAY TO BE
WESTERLY WIND LAKE ENHANCED PRECIPITATION. THIS IS DUE TO 850MB
TEMPS FALLING TO -8C OVER WESTERN UPPER MICHIGAN BY 18Z MONDAY.
WILL HIGHLIGHT THE HIGHEST POPS OVER THE HIGHER TERRAIN FROM THE
KEWEENAW THROUGH THE GOGEBIC RANGE AND ALSO OVER THE HURON
MOUNTAINS. WESTERLY WINDS LOOK TO BACK SLIGHTLY IN THE AFTERNOON
AHEAD OF TROUGH DROPPING SOUTH ACROSS WESTERN LAKE SUPERIOR DURING
THE LATE AFTERNOON. THIS MAY CAUSE THE BEST PRECIPITATION TO BE
FOCUSED MORE OVER THE KEWEENAW DURING THE AFTERNOON. THEREFORE...DID
OPT TO TRIM POP/QPF AMOUNTS OVER GOGEBIC/ONTONAGON COUNTIES SOME
DURING THE AFTERNOON HOURS. SINCE WETBULB ZERO VALUES FALL OVER THE
WEST AS THE COLD AIR SURGES EAST ACROSS THE U.P. EXPECT PRECIP TO
FALL AS SNOW OVER THE WEST...BUT COULD MIX WITH RAIN AT TIMES NEAR
LAKE SUPERIOR. SNOWFALL AMOUNTS DURING THE MORNING AND MOST OF THE
AFTERNOON SHOULD BE LIGHT...WITH LOCATIONS SEEING AMOUNTS UNDER AN
INCH. OVER THE REST OF UPPER MICHIGAN DURING THIS PERIOD...EXPECT
BREEZY WESTERLY WINDS AND CLOUDY CONDITIONS...BUT LITTLE TO NO
PRECIPITATION IS EXPECTED. THE BEST OPPORTUNITY WOULD BE OVER THE
EAST RIGHT ALONG THE LAKE SUPERIOR/MICHIGAN SHORELINES AS LAKE
ENHANCED PRECIPITATION WILL TRY TO PARALLEL THOSE AREAS.
THEN TOWARDS SUNSET...THE SURFACE TROUGH WILL DROP SOUTH ONTO THE
WESTERN U.P. SHORELINE AND BRING AN ENHANCED AREA OF CONVERGENCE
AND PRECIPITATION. EXPECT THERE TO BE MODERATE TO HEAVY
PRECIPITATION AS THIS TROUGH SLIDES THROUGH THE WESTERN U.P. DURING
THE EVENING HOURS AND THEN THROUGH CENTRAL UPPER MICHIGAN DURING
THE OVERNIGHT HOURS. 850MB TEMPS WILL ACTUALLY WARM A COUPLE
DEGREES BEHIND THE TROUGH...BUT THE DEEP MOISTURE AND CYCLONIC
FLOW ON THE BACK SIDE OF THE SURFACE AND 850MB LOW...ALONG WITH
UPSLOPE WINDS...WILL SUPPORT LAKE ENHANCED PRECIPITATION THROUGH A
GOOD PORTION OF THE NIGHT OVER THE WESTERN CWA AND INTO TUESDAY
MORNING OVER THE NORTH CENTRAL CWA. THE PRECIPITATION DURING THIS
PERIOD SHOULD FALL AS SNOW EXCEPT FOR LOCATIONS RIGHT ALONG THE
LAKE SUPERIOR SHORELINE WHERE THE NORTH-NORTHWEST WINDS WOULD
PRODUCE SOME HEAT TRANSFER FROM THE LAKE AND LEAD TO SOME RAIN/SNOW
MIX. AS FOR RATIOS/AMOUNTS...THINKING THE SNOW RATIOS WILL BE AROUND
OR JUST BELOW 10-1 WITH THE BEST FORCING BEING BELOW THE DGZ AND
SNOW FLAKES FALLING FROM ALOFT CLUMPING TOGETHER AS THEY REACH THE
STRONG UPWARD MOTION NEAR THE SURFACE. AS FOR QPF AMOUNTS...HPC
INDICATES NAM IS THE COLDER SOLUTION IN THE MID LEVELS (BY AROUND
2C) BEHIND THE LOW...WHICH MAY BE PART OF THE REASON IT IS MUCH
HIGHER ON QPF AMOUNTS WITH THE LAKE ENHANCED SNOW BEHIND THE
TROUGH. SINCE THE HIGHER RESOLUTION OF THE NAM AND 4KM
NEST PICK UP THE TERRAIN ENHANCEMENT...DID BLEND THAT
WITH THE PREFERRED WARMER AND COARSER MODELS FOR QPF
MONDAY AFTERNOON THROUGH TUESDAY MORNING. THIS CREATES
24HR VALUES OF 0.5-0.75IN FROM IRONWOOD THROUGH THE
KEWEENAW AND ALSO OVER THE WESTERN SIDE OF THE HURON
MOUNTAINS. AT 10-1 SLR VALUE...SNOWFALL AMOUNTS IN THE 3-6 INCH
RANGE SEEM REASONABLE IN THOSE AREAS AFTER FACTORING SOME
MELTING INITIALLY ON MONDAY WHEN THE SNOWFALL RATES ARE LIGHTER.
THAT SEEMS TO FIT IN WITH OUR ADVISORY CRITERIA AND WILL LIKELY END
UP JUST UNDER THE 6INCH IN 12HR MARK FOR WARNINGS. CIPS TOP ANALOGS
(BASED OFF THE SLIGHTLY COLDER NAM SOLUTION) SHOW MEAN SNOWFALL
AMOUNTS OF 4-8 INCHES OF A 72HR PERIOD AND PROBABILITIES OF SEEING
6IN OF SNOW AROUND 60 PERCENT. THINK THE FORECAST MATCHES UP PRETTY
WELL WITH THAT IDEA (ALONG WITH HPC GUIDANCE) AND WILL CONTINUE TO
HIGHLIGHT THIS MEASUREABLE SNOW EVENT IN THE HWO AND ISSUE AN SPS TO
HIGHTEN THE AWARENESS.
SURFACE TROUGH WILL QUICKLY SHIFT EAST OF THE AREA ON
TUESDAY...AS AN AREA OF HIGH PRESSURE SLIDES INTO THE NORTHERN
PLAINS. EXPECT A DIMINISHING PRECIPITATION TREND FROM WEST TO EAST
ACROSS THE CWA WITH THE DEEPER MOISTURE DEPARTING. THROUGH THE REST
OF THE WEEK...EXPECT NORTHWESTERLY FLOW TO BE IN PLACE AS THE LOW
SITS OVER QUEBEC AND A SERIES OF HIGHS DROP SOUTHEAST THROUGH THE
NORTHERN PLAINS. 850MB TEMPS THROUGH THE REST OF THE PERIOD SHOULD
BE RIGHT AROUND -8C WHICH LEADS TO PLENTY OF LAKE INSTABILITY. WILL
CONTINUE TO HIGHLIGHT CHANCE POPS OR HIGHER IN THE TRADITIONAL
NORTHWEST FLOW LOCATIONS THROUGH FRIDAY. HIGHEST POPS AND POTENTIAL
FOR ACCUMULATION SNOWFALL WILL BE OVER THE EASTERN U.P. WITH THE
LONGER FETCH AND CLOSER PROXIMITY TO THE BETTER MOISTURE UNDER THE
UPPER LOW. THERE WILL BE A COUPLE BRIEF PERIODS WHERE THE LAKE
EFFECT PRECIPITATION WILL PICKUP AS WEAK SHORTWAVES AND BETTER
MOISTURE SWEEP THROUGH. CIPS TOP ANALOGS FOR THE MID WEEK PERIOD
UNDER PERSISTENT LAKE EFFECT SNOWFALL SHOWS PROBABILITY FOR 4IN OF
SNOW IN A 72HR PERIOD BEING AROUND 60 PERCENT IN THE TRADITIONAL
FAVORED NORTHWEST FLOW LOCATIONS. BEING THAT IS OVER A 3 DAY
PERIOD...THING THOSE VALUES ARE REASONABLE WITH LIGHT ACCUMULATIONS
OCCURRING THROUGH THE END OF THE WORK WEEK.
THE UPPER TROUGHS INFLUENCE ON THE UPPER GREAT LAKES LOOKS TO
WEAKEN THIS WEEKEND AS IT SHIFTS EAST INTO THE NEW ENGLAND STATES.
BUT ANOTHER SHORTWAVE ROUNDING THE UPPER RIDGE OVER THE ROCKIES
WILL TRY TO MOVE INTO THE AREA FOR THE SECOND HALF OF THE WEEKEND.
WILL JUST GO WITH A GENERAL CONSENSUS AND HAVE CHANCE POPS WITH
TEMPERATURES REMAINING BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 242 PM EDT SUN OCT 20 2013
TIMING OF THE APPROACHING SNOW AND LOWER CEILINGS HAS BEEN VERY
TRICKY TODAY...MADE TRICKIER BY FOG/STRATUS THIS MORNING ACROSS THE
HIGHER ELEVATIONS OF THE W HALF OF UPPER MI. THIS MAINLY INFLUENCED
SAW...WHICH WAS RIGHT ON THE CLEARING LINE THANKS TO LIGHT DOWNSLOPE
WINDS MUCH OF THE MORNING. CEILINGS HAVE BEEN HOVERING BETWEEN HIGH
END MVFR AND VFR EARLY THIS AFTERNOON...WITH THE RAIN/SNOW LINE AND
MVFR TO IFR CEILINGS NEARING FROM N CENTRAL WI THIS AFTERNOON.
EXPECT DETERIORATING CONDITIONS AT ALL 3 SITES...WITH RAIN SLOWLY
MIXING WITH SNOW OVERNIGHT. THE MIX OF RAIN AND SNOW WILL LIKELY
CHANGE OVER TO ALL SNOW AT IWD SHORTLY BEFORE DAYBREAK AS COOLER AIR
RUSHES IN ON FAVORABLE W-NW WINDS. THE CHANGE OVER SHOULD TAKE A
COUPLE MORE HOURS AT CMX...WITH A LOW TEMP IN THE MID 30S OVERNIGHT.
STRONGER W WINDS WILL BE COMMON STARTING 09-15Z W TO E...WITH GUSTS
OF 25-30KTS /STRONGEST AT CMX/...AS CEILINGS SLOWLY IMPROVE AS THE
BULK OF THE MOISTURE EXITS AS THE SFC LOW PUSHES INTO E QUEBEC.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 510 AM EDT SUN OCT 20 2013
LOW PRESSURE MOVEING OUT OF THE DAKOTAS WILL BEGIN TO INTENSIFY OVER
THE UPPER MISSISSIPPI VALLEY TODAY AND THEN MOVE THROUGH THE UPPER
GREAT LAKES TONIGHT AND MONDAY. AS THIS OCCURS...WINDS WILL
STRENGTHEN ACROSS THE LAKE...FIRST OUT OF THE SOUTH TO SOUTHEAST
AHEAD OF THE LOW THIS EVENING AND THEN OUT OF THE WEST BEHIND THE
LOW LATE TONIGHT INTO MONDAY. THERE STILL ARE SOME DIFFERENCES
IN THE EXACT TRACK AND STRENGTH OF THE LOW AS IT MOVES ACROSS LAKE
SUPERIOR ON MONDAY...SO WIND SPEED/DIRECTIONS ARE STILL UNCERTAIN.
AT THIS TIME...IT APPEARS THE STRONGEST WINDS WILL BE BEHIND THE LOW
ON MONDAY AND MONDAY NIGHT...WHEN WEST GALES TO 35-40KTS VEERING TO
THE NORTH ARE EXPECTED. ONCE THE LOW DEPARTS THE AREA...EXPECT
NORTHWESTERLY WINDS UP TO 25KTS TO REMAIN OVER LAKE SUPERIOR INTO
WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH TUESDAY AFTERNOON FOR
LSZ265>267.
GALE WATCH FROM MONDAY EVENING THROUGH TUESDAY MORNING FOR
LSZ264.
GALE WATCH FROM MONDAY MORNING THROUGH TUESDAY MORNING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KF
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
202 PM EDT SUN OCT 20 2013
.SYNOPSIS...
ISSUED AT 335 AM EDT SUN OCT 20 2013
COOL WEATHER WITH PERIODS OF LAKE EFFECT SHOWERS WILL CONTINUE
INTO NEXT WEEK...AS A BROAD TROUGH OF LOW PRESSURE REMAINS OVER THE
GREAT LAKES. EVEN COLDER AIR WILL ENGULF THE GREAT LAKES AND UPPER
MIDWEST BY MONDAY...AS ANOTHER WEAK STORM SYSTEM EXITS NORTHEAST
INTO QUEBEC EARLY IN THE WORK WEEK. TEMPERATURES MAY GET COLD ENOUGH
TO BRING THE FIRST SNOWFALL OF THE SEASON...ESPECIALLY TO INTERIOR
SECTIONS OF EASTERN UPPER AND NORTHERN LOWER MICHIGAN.
&&
.UPDATE...
ISSUED AT 201 PM EDT SUN OCT 20 2013
SCT-BKN STCU DECK HAS EXPANDED ACROSS THE CWA OVER THE LAST FEW
HOURS...LEADING TO PARTLY SUNNY SKIES FOR MOST AREAS. REMAINING
SMALL BATCH OF LAKE INDUCED SHOWERS CONTINUES TO WORK UP THROUGH
THE STRAITS INTO EASTERN UPPER MICHIGAN...AS ANTICIPATED. BUT DRY
WEATHER ELSEWHERE.
UPSTREAM...SFC LOW PRESSURE SLIDING SOUTHEASTWARD THROUGH THE
UPPER MIDWEST IN RESPONSE TO SMALL UPPER JET CORE PUSHING ACROSS
IOWA...AND SUBSTANTIALLY STRONGER SHORT WAVE ENERGY DIVING
SOUTHWARD OUT OF SOUTH-CENTRAL CANADA. INCREASING WARM ADVECTION
AHEAD OF THE LOW ALREADY PUSHING A BAND OF PRECIP THROUGH
WISCONSIN. THIS BATCH OF WARM ADVECTION FORCED PRECIP WILL PIVOT
SW-NE UP INTO NRN MICHIGAN OVER THE NEXT FEW HOURS LEADING TO A
PERIOD RAINFALL ACROSS THE CWA THIS EVENING. MAIN PERIOD OF
RAINFALL LOOKING TO OCCUR BETWEEN 00Z AND 06Z AS SUBSTANTIALLY
WARM AIR SURGES UP INTO NRN MICHIGAN. WILL CATCH A BIT OF A BREAK
DURING THE OVERNIGHT HOURS BEFORE STRONG SHORT WAVE DRIVES ACROSS NRN
MICHIGAN LATE OVERNIGHT THROUGH MONDAY MORNING...AND WRAP AROUND
MOISTURE/COLDER AIR ROTATE INTO THE REGION. TRANSITION DAY ON
MONDAY.
UPDATE ISSUED AT 1036 AM EDT SUN OCT 20 2013
GOT A BIT OF A BREAK DURING THE OVERNIGHT HOURS WITH CLOUDS THINNING/
CLEARING OUT OVER A GOOD PART OF CWA...WELL DOWNWIND OF THE LAKES.
BUT MEANWHILE...LAKE AGGREGATE TROUGH ANALYZED FROM WESTERN LAKE
SUPERIOR DOWN INTO NRN LAKE MICHIGAN THIS MORNING. MESOSCALE SFC
LOW HAS DEVELOPED OVER NRN LAKE MICHIGAN GIVEN THE WEAKER SYNOPTIC
WIND REGIME/SHORELINE ORIENTATION AND OFFSHORE WIND COMPONENT. A
FEW POCKETS OF LAKE INDUCED SHOWERS LINGER WITHIN THIS FEATURE
ACROSS NRN LAKE MICHIGAN (CAN SEE THE LOW LEVEL SPIN IN THE RADAR
DATA...PUSHING UP INTO PARTS OF NW LOWER INTO THE STRAITS AND
EASTERN UPPER.
REST OF TODAY...POTENT SHORT WAVE AND POCKET OF COLDEST AIR OF THE
SEASON ON TRACK TO DROP INTO THE UPPER MIDWEST...THAT WILL
ULTIMATELY DRIVE A DEEPENING SFC LOW/POTENT COLD FRONT THROUGH THE
REGION...LATE TONIGHT AND MONDAY MORNING. AHEAD OF THIS DEVELOPING
SYSTEM...LOW LEVEL FLOW WILL BACK MORE SOUTHERLY AS WE GO THROUGH
THE AFTERNOON...PUSHING REMAINING LAKE INDUCED SHOWERS UP THROUGH
EASTERN UPPER MICHIGAN. PULSE OF LOW-MID LEVEL WARM ADVECTION
FORCING AHEAD OF THAT DEVELOPING SYSTEM ALREADY PRODUCING A BAND
OF PRECIP EXPANDING INTO WESTERN WISCONSIN THIS MORNING. FORCING
LOOKING TO DEVELOP INTO THE W/SW PART OF THE CWA BY LATE
AFTERNOON. GOING FORECAST ALREADY HAS CHANCY POPS OVER THE SW
COUNTIES AND A SLIVER OF EASTERN UPPER MICHIGAN...WHICH LOOKS FINE
FOR NOW.
HAVE TWEAKED SKY FORECASTS FOR THE BALANCE OF THE DAY BASED ON
TRENDS...TO HAVE A LITTLE MORE SUNSHINE THROUGH MIDDAY. ALSO
TWEAKED TEMP CURVE FOR TONIGHT. BIG SURGE OF WARM AIR ALOFT AND
INCREASING SOUTHERLY WINDS SHOULD ACTUALLY RESULT IN FLAT LINE OR
EVEN WARMING TEMPS TONIGHT. JUST HOW WARM DEPENDS ON HOW FAR NORTH
THE SFC WARM FRONT CAN GET...BUT CAN ENVISION SOME LOCATIONS
PUSHING THE HIGH 40S TO NEAR 50 OVERNIGHT...BEFORE IT ALL CRASHES
ON MONDAY WITH FROPA.
UPDATE ISSUED AT 657 AM EDT SUN OCT 20 2013
CLOUDS HAVE OPENED UP CONSIDERABLY IN PARTS OF NE LOWER AND EASTERN
UPPER MI. THIS WILL TEND TO SELF-DESTRUCT WITH HEATING TODAY...THE
SUB-800MB AIRMASS REMAINS ON THE MOIST SIDE. SOME ADJUSTMENTS MADE
TO EARLY-MORNING CLOUD COVER.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 335 AM EDT SUN OCT 20 2013
MUCH DISCUSSED DEEP TROUGHING CONTINUES TO DOMINATE GREAT LAKES
WEATHER AT THIS EARLY HOUR...DOWNSTREAM OF EQUALLY IMPRESSIVE
RIDGING POCKING UP AND BEYOND THE NORTHWEST TERRITORIES. SUBTLE WAVE
TRAVERSING WITHIN THIS FLOW...NOW IN THE PROCESS OF FURTHER
DEAMPLIFYING AND CUTTING ACROSS THE NORTHERN LAKES. THIS...COMBINED
WITH STILL MORE THAN SUPPORTIVE OVER-WATER INSTABILITY (H8
TEMPERATURES RIGHT AROUND -2C PER HIGH RES RAP AND 00Z SOUNDING
ANALYSIS)...CONTINUES TO KICK OFF LAKE ENHANCED RAIN SHOWERS OFF
NORTHERN LAKE MICHIGAN (EVEN HAD SOME LEGITIMATE SNOWFLAKES MIX IN
WITH THE RAIN HERE ON TOP OF THE HILL). OTHERWISE...A RATHER QUIET
AND TOUCH CHILLY NIGHT...WITH CURRENT READINGS MAINLY IN THE 30S AND
LOWER 40S. MAIN SYSTEM OF INTEREST THROUGH THE SHORT TERM IS WELL
DEFINED SHORTWAVE/VORT LOBE DROPPING STRAIGHT SOUTH THROUGH CENTRAL
MANITOBA. THIS SYSTEM WILL DRUM UP A RATHER RESPECTABLE AREA OF LOW
PRESSURE TONIGHT AS IT DROPS INTO MINNESOTA. GOOD MID LEVEL SUPPORT
AND LOW LEVEL ENERGY SUPPLIED BY WARM LAKE WATERS WILL HELP DEEPEN
THIS SURFACE LOW AS IT MOVES UP INTO EASTERN LAKE SUPERIOR BY MONDAY
MORNING. THIS SYSTEM WILL BRING MORE WIDESPREAD RAINS HEADING INTO
TONIGHT...AND PERHAPS A GALE EVENT ON PARTS OF THE BIG WATERS. SHORT
TERM FORECAST CONCERNS CENTER ON ADDRESSING THE IMPACTS OF THIS
SYSTEM.
BY AND LARGE...A RATHER NON-EVENTFUL WEATHER DAY EXPECTED TODAY.
CURRENT OVERHEAD WAVE WILL HAVE EXITED STAGE RIGHT BY
SUNRISE...LEAVING PURE LAKE PROCESSES FOR ANY ADDITIONAL SHOWER
DEVELOPMENT THROUGH MID AFTERNOON. EXPECT THERE WILL BE SOME ONGOING
TO START THE DAY...ESPECIALLY ALONG THE NORTHWEST LOWER COASTLINE
WHERE WIND CONVERGENCE WILL BE MAXIMIZED. LAKE PROCESSES WILL BE A
DOWNWARD ONE HEADING THROUGH THE DAY AS WINDS BACK SOUTHERLY AND
WEAK MID LEVEL RIDGING BUILDS OVERHEAD. ATTENTION LATE THIS
AFTERNOON INTO THE OVERNIGHT TURNS TO STRONG WAA RESPONSE AHEAD OF
EARLIER MENTIONED DEEPENING SURFACE LOW. RATHER IMPRESSIVE
ISENTROPIC UPGLIDE SIGNATURE VIA FORCED ASCENT ON NOSE OF 40+ KNOT
LOW LEVEL JET...WITH WELL OVER HALF INCH PWATS ALSO SURGING NORTH
INTO THE AREA WITH THIS JET. ABOVE LOOKS TO KICK OFF A RATHER LARGE
AREA OF RAIN...WHICH WILL SPREAD RAPIDLY NORTHEAST ACROSS OUR AREA
LATE THIS AFTERNOON INTO THIS EVENING. PER FULL 00Z GUIDANCE
ANALYSIS...MAY AMP UP RAIN CHANCES SOME SOUTHWEST THIRD OF THE AREA
AFTER 21Z TODAY...WITH INHERITED CATEGORICAL WORDING INTO THIS
EVENING LOOKING GREAT. DRY SLOT PUNCHES IN FROM THE SOUTHWEST
THROUGH THE OVERNIGHT...LIKELY ABRUPTLY ENDING RAINS AS IT DOES SO.
MAY SEE SOME LAKE SHOWERS ATTEMPT TO FIRE FAR NORTHERN LAKE MICHIGAN
TOWARDS MORNING WHERE MOISTURE WILL REMAIN DEEPER AND POST-COLD
FRONT CAA REGIME ONCE AGAIN DROPS H8 READINGS TO JUST BELOW 0C.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 335 AM EDT SUN OCT 20 2013
CLASSIC LATE AUTUMN WX WILL REMAIN IN PLACE FOR THE UPCOMING
WEEK...A BIT AHEAD OF SCHEDULE. PLENTY OF UPPER TROFFING WILL REMAIN
IN PLACE IN CENTRAL CANADA AND ADJOINING PARTS OF THE STATES. THE
LOWEST HEIGHTS WILL BE OVERHEAD MONDAY EVENING...AS AN UPPER LOW
CROSSES EASTERN SUPERIOR. HOWEVER...HEIGHT RECOVERY AFTER THAT LOW
EJECTS TO THE NE WILL BE ANEMIC. THAT WILL MAINTAIN MIXED PRECIP AS
A SIGNIFICANT FORECAST CONCERN...ESPECIALLY DURING THE LATE NIGHT/
EARLY MORNING HOURS. PRECIP TRENDS ARE THE MAIN CONCERN.
MONDAY...500MB LOW MOVES FROM INL TO MQT. 999MB SURFACE LOW OVER
EASTERN SUPERIOR WILL LIFT NE TO SSW OF JAMES BAY...WITH A NEW LOW
SPINNING UP ALONG A SECONDARY COLD FRONT IN CENTRAL SUPERIOR DURING
THE AFTERNOON. THE BACK EDGE OF THE WARM CONVEYOR BELT WILL BE ABOUT
TO EXIT NE LOWER MI AT 12Z...WITH DRIER MID LEVEL AIR IN THE PROCESS
OF POURING INTO NORTHERN LOWER. HOWEVER...OVERLAKE INSTABILITY WILL
BE INCREASING CONSIDERABLY AS COLDER LOW LEVEL AIR POURS IN. 850MB
TEMPS OVER NORTHERN LAKE MI WILL NEAR -6C BY 18Z...-8C BY 00Z.
MEANWHILE...EASTERN UPPER WILL REMAIN ON THE SOUTHERN PERIPHERY OF
THE DEEPER WRAPAROUND MOISTURE.
COULD STILL BE SOME FRONTAL SHRA IN FAR EASTERN SECTIONS TO START
THE MORNING. SCT SHRA WILL GET GOING IN WSW-FLOW AREAS (ESPECIALLY
FROM LEELANAU NORTHWARD) DURING THE MORNING...AS WELL AS IN EASTERN
UPPER. THESE COULD BECOME MORE NUMEROUS IN THE AFTERNOON...AS
INSTABILITY INCREASES (DELTA T/S IN THE LOWER 20S) AND THE CORE OF
THE DRY SLOT MOVES EAST. 1000-850MB WINDS WILL VEER TO THE WEST
DURING THE AFTERNOON...WITH INVERSION HEIGHTS A REASONABLY HEALTHY
6-7K FT. WILL INTRODUCE A SMALL CHANCE FOR A MIX VERY LATE IN THE
DAY IN THE INTERIOR OF EASTERN UPPER...WHERE THE SURFACE-BASED
MELTING LAYER IS NARROWING BELOW 1K FT.
MAX TEMPS IN THE 40S (TO LOWER 50S NE LOWER) AND EARLY...WITH
FALLING TEMPS IN THE PM. BRISK TO WINDY...ESPECIALLY NEAR LAKE MI.
MON NIGHT/TUESDAY...UPPER LOW WILL GRADUALLY LIFT OUT TOWARD JAMES
BAY...THOUGH WITH A SUBSTANTIAL SHORTWAVE ROUNDING IT/S SOUTHERN
FLANK LATE MONDAY NIGHT. THAT WILL DRIVE THE SECONDARY FRONT INTO
EASTERN UPPER MI LATE MONDAY NIGHT...AND ACROSS THE REST OF THE
FORECAST AREA ON TUESDAY. 1000-850MB WINDS WILL BRIEFLY BACK MORE
WSW AGAIN JUST AHEAD OF THIS TROF...ALLOWING THE INITIAL 850MB
THERMAL TROF TO MOVE EAST AND BOOSTING 850MB TEMPS TO -5C. WINDS
RAPIDLY VEER NW BEHIND THE TROF...AND COLD ADVECTION RESUMES. AFTER
CONTINUED LOW-END-ISH LAKE EFFECT MONDAY EVENING (THOUGH WITH MORE
SNOW MIXING IN AS DIURNAL HEATING IS LOST)...PRECIP WILL
SUBSTANTIALLY RAMP UP OVERNIGHT AS THE SECONDARY FRONT AND SHARP
1000-850MB CONVERGENCE ARRIVES. SLUSHY ACCUMS UP TO AN INCH SEEM A
DISTINCT POSSIBILITY MONDAY NIGHT NEAR GLR/BOYNE CITY/MANCELONA...
AND IN WESTERN CHIP. TUESDAY WILL SEE A WOBBLY NW FLOW...BUT WITH
MID-LEVEL DRYING/SUBSIDENCE AS THE VORT LOBE MOVES EAST. SOME LAKE
EFFECT WILL CONTINUE...ESPECIALLY IN THE MORNING...WITH DISRUPTIVE
DIURNAL HEATING DISORGANIZING THINGS IN THE PM. SOME SLOPPY LIGHT
ACCUMS ARE AGAIN POSSIBLE IN THE MOST FAVORED AREAS OF BOTH
PENINSULAS IN THE MORNING.
MIN TEMPS WITHIN A FEW DEGREES OF 30F. MAX TEMPS NEAR 40F TO THE MID
40S. AND IT WILL REMAIN BRISK TO WINDY.
REST OF THE FORECAST...FEW CHANGES NEEDED...AS COLD AND SHOWERY WX
WILL PERSIST AS CURRENTLY FORECAST. NEW ECMWF IS FLAT-OUT COLD
STRAIGHT THRU 240HRS. (PROBABLY BEST FOR MOTHER NATURE TO GET THIS
OUT OF HER SYSTEM NOW.)
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 201 PM EDT SUN OCT 20 2013
VFR CONDITIONS ANTICIPATED THROUGH THE BALANCE OF THE AFTERNOON
HOURS WITH SCT-BKN CLOUDS.
LOW PRESSURE OVER THE UPPER MIDWEST WINDS UP THIS AFTERNOON BEFORE
SWINGING UP THROUGH THE REGION TONIGHT. SURGE OF WARM AIR AND RESULTING
RAINFALL ARRIVES EARLY THIS EVENING AHEAD OF THE LOW...LOWERING CIGS/VSBYS
TO MVFR FOR MUCH OF THE EVENING HOURS. LOW LEVEL WIND SHEAR ALSO A
GOOD BET THIS EVENING AS LOW LEVEL WINDS RAMP UP.
MAIN BATCH OF RAINFALL EXITS QUICKLY OVERNIGHT...AFTER 06Z...BUT
WITH VFR CIGS PERSISTING THROUGH THE BALANCE OF THE NIGHT. COLD
FRONT SWEEPS THROUGH MONDAY MORNING LEADING TO GUSTIER WESTERLY
WINDS THROUGH MONDAY. MVFR CIGS PERSIST WITH SHOWERS NEAR LAKE
MICHIGAN.
&&
.MARINE...
ISSUED AT 335 AM EDT SUN OCT 20 2013
RELATIVELY LIGHT WINDS THIS MORNING GIVES WAY TO
INCREASINGLY GUSTY SOUTH FLOW LATER THIS AFTERNOON...AND ESPECIALLY
TONIGHT...AS LOW PRESSURE INTENSIFIES AND PUSHES INTO EASTERN LAKE
SUPERIOR BY MONDAY MORNING. TIGHTENING PRESSURE GRADIENT AND ONSET
OF IMPRESSIVE SURGE OF CAA WILL LEAD TO VERY GUSTY WEST TO SOUTHWEST
WINDS DURING THE DAY MONDAY...WITH THE STRONGEST WINDS EXPECTED OVER
NORTHERN LAKE MICHIGAN. GALE FORCE WIND GUSTS APPEAR INCREASINGLY
LIKELY...RESULTING IN AN UPGRADE TO INHERITED NORTHERN LAKE MICHIGAN
GALE WATCH TO A WARNING. IN ADDITION...WIND GUST MAY REACH GALE
FORCE ACROSS WHITEFISH BAY AND THE ST. MARYS RIVER LATER MONDAY
MORNING THROUGH THE AFTERNOON. CONFIDENCE NOT HIGH ENOUGH TO WARRANT
A GALE WARNING...BUT ENOUGH CONCERN TO HOIST A GALE WATCH FOR THESE
AREAS. ADDITIONAL SCA/S WILL LIKELY BE NEEDED FOR OTHER NEARSHORE
ZONES...BUT WILL FOCUS ON GALE CONDITIONS AND PUNT ADVISORY
ISSUANCES TO FUTURE FORECAST SHIFTS. WELCOME TO FALL ON THE GREAT
LAKES!
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...GALE WARNING FROM 5 AM MONDAY TO 11 AM EDT TUESDAY FOR LHZ345.
LM...GALE WARNING FROM 5 AM MONDAY TO 11 AM EDT TUESDAY FOR LMZ341-
342-344>346.
LS...GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR LSZ321-
322.
&&
$$
UPDATE...BA
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...BA
MARINE...MB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
146 PM EDT SUN OCT 20 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 344 AM EDT SUN OCT 20 2013
INTERVALS OF SHOWERS WILL CONTINUE THROUGH THE MAJORITY OF THE WEEK
THIS WEEK AS A STRONG SURGE OF COLD CANADIAN AIR TAKES HOLD OF THE
AREA. WAVES OF LOW PRESSURE WILL COMBINE WITH LAKE EFFECT TO BRING
THE OCCASIONAL SHOWERS TO THE AREA. COLD ENOUGH AIR IS EXPECTED TO
MOVE IN TO ALLOW FOR SOME SNOW TO MIX IN AT TIMES WITH THE RAIN
SHOWERS. HIGHS WILL LIKELY REMAIN ONLY IN THE 40S MANY TIMES THIS
WEEK.
&&
.UPDATE...
ISSUED AT 1205 PM EDT SUN OCT 20 2013
I ADDED THUNDERSTORMS TO OUR ZONE FORECASTS TONIGHT. AFTER
LOOKING AT THE 1000 J/KG OF MOST UNSTABLE CAPE OVER LAKE MICHIGAN
EARLY THIS EVENING. RAP AND NAM SOUNDINGS THIS EVENING INTO THE
OVERNIGHT SHOW NO INVERSION TO CAPE THE INSTABILITY...WHICH IS
UNLIKE LAST NIGHT WHEN WE HAD THUNDERSTORMS BUT THE INSTABILITY WAS
CAPED AROUND 120000 FT. THE SOUNDINGS GIVE EQUILIBRIUM LEVELS AS
HIGH AS 350000 FT THIS EVENING. THE CAPE IS SKINNY...BUT GIVEN
THE 50 KNOT LOW LEVEL JET THAT POKES INTO OUR SOUTHWEST CWA BETWEEN
8 PM AND 11 PM... PLUS OUR AREA BEING IN THE EXIT REGION OF THE
POLAR JET TONIGHT. THE NAM THUNDERSTORMS PROBABILITY PROG HAS
NUMBERS AS HIGH AS 60 PCT OVER LAKE MICHIGAN AND 40 PCT INLAND
NORTH OF HOLLAND TO US-131 JUST BEFORE MIDNIGHT. THE SPC 03Z SREF
ALSO FORECASTS THUNDERSTORMS OVER LAKE MICHIGAN INTO SOUTHWEST
LOWER MICHIGAN SIMILAR TO THE NAM THUNDERSTORM PROP CHART. ALL OF
THIS TELLS ME WE SHOULD SEE THUNDERSTORMS DEVELOPING OVER LAKE
MICHIGAN EARLY TONIGHT THEY WILL THEN MOVE INLAND DURING THE MID
EVENING HOURS JUST AHEAD OF THE COLD FRONT. DUE TO THE SOUTHWEST
WINDS THE BEST INSTABILITY (AIDED BY THE WARMTH OF LAKE MICHIGAN)
WILL MOSTLY BE NORTH OF A LINE FROM HOLLAND TO ALMA.
I ALSO INCREASED THE POP TONIGHT SINCE THERE IS LITTLE QUESTION
GIVEN THE WARM LAKE AND DYNAMICS PLUS A DECENT SHOT AT DEEP
MOISTURE THAT THERE WILL BE SHOWERS TONIGHT. ANY STORMS MAY HAVE
SMALL HAIL GIVEN THE FREEZING LEVEL BEING BELOW 7000 FT.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 344 AM EDT SUN OCT 20 2013
PCPN TRENDS AND TYPE ARE THE MAIN FOCUS OF THE FCST PACKAGE TODAY.
THE SHOWER ACTIVITY THAT WAS WIDESPREAD ACROSS THE AREA LAST EVENING
IS SCATTERING OUT AND DISSIPATING EARLY THIS MORNING. THIS IS DUE TO
MAINLY THE UPPER FLOW TRANSITIONING TO ANTI-CYCLONIC AS THE LAST
SHORT WAVE IN THIS SEQUENCE IS NOW LIFTING TO THE E/NE THIS MORNING.
WE EXPECT THE SHOWER ACTIVITY TO PRETTY MUCH END FOR A FEW HOURS AS
SHORT WAVE RIDGING BUILDS IN AND WE LOSE THE LOW LEVEL MOISTURE.
SOME BREAKS IN THE CLOUDS WILL BE LIKELY ONCE AGAIN...HOWEVER JUST
AS THE LOW LEVEL MOISTURE MOVES OUT...MID AND HIGH LEVEL MOISTURE
FROM THE NEXT SYSTEM MOVES RIGHT IN.
THE NEXT SYSTEM IN THE SEQUENCE WILL BE BRINGING PCPN TO THE FAR NW
CORNER OF THE CWFA AS EARLY AS LATE THIS AFTERNOON. THIS WAVE IS
CURRENTLY LOCATED NORTH OF LAKE WINNIPEG AND DROPPING SOUTHEAST
QUICKLY. IT WILL MERGE WITH ANOTHER SHORT WAVE COMING INTO THE
DAKOTAS. THE TRACK OF THE SHORT WAVE AND SFC LOW WILL FAVOR THE NRN
SECTION OF THE CWFA FOR THE BEST PCPN CHCS. IT DOES LOOK LIKE THE
ENTIRE CWFA WILL HAVE A CHC OF RAIN AS THE COLD FRONT PASSES THROUGH
THE AREA VERY LATE TONIGHT AND MON MORNING.
THE THREAT OF LAKE EFFECT RAIN SHOWERS WILL BE THERE ON MON WITH
DELTA T/S EXPECTING TO BE AROUND 20C. THE THREAT DOES NOT LOOK TO BE
VERY BIG HOWEVER AS THE DRY SLOT WILL AFFECT THE AREA BEHIND THE
FRONT. MOISTURE PROFILES INDICATE THAT THEY WILL BE DEEP ENOUGH FOR
SOME PCPN TO BE GENERATED AS THE DGZ WILL BARELY BE SATURATED.
INVERSION HEIGHTS ARE SOMEWHAT LOW AS THE UPPER LOW AND CORE OF THE
CYCLONIC FLOW STAYS MAINLY NORTH OF THE AREA.
THE THREAT OF SHOWERS WILL CONTINUE TO BE POSSIBLE MON NIGHT AND
EARLY TUE. THIS IS THE PERIOD WHEN IT LOOKS LIKE WE WILL SEE A
POTENTIAL OF PCPN MIXING WITH OR CHANGING TO SNOW WITH H850 TEMPS
DROPPING TO ALMOST -7C AND FREEZING LEVELS DROPPING BELOW 2000 FT.
THE BEST POTENTIAL OF SEEING SOME SNOW WILL BE UP ACROSS CENTRAL
LOWER MICHIGAN AT THE HIGHER ELEVATIONS. IN ADDITION TO THE
POSSIBILITY OF SNOW...WE CAN NOT RULE OUT THUNDER ALONG THE
LAKESHORE WITH LAKE MODIFIED PARCELS GENERATING OVER 1000 J/KG OF
CAPE AND PARCELS REACHING TO -20C ISOTHERM. WATERSPOUTS WILL ALSO
REMAIN POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 344 AM EDT SUN OCT 20 2013
THERE SEEMS TO BE NO END IN SIGHT TO THE COOL AND UNSETTLED PATTERN
AS DEEP UPPER TROUGHING PERSISTS OVER THE GREAT LAKES REGION THROUGH
ALL OF NEXT WEEK. TEMPERATURES WILL AVERAGE AROUND 10 DEGREES BELOW
NORMAL.
H8 TEMPS ARE PROGGED TO REMAIN RIGHT AROUND -6C THROUGH MOST OF THE
WEEK CREATING EXTREME LAKE INSTABILITY WITH DELTA T/S IN EXCESS OF
20C. OCCASIONAL SHORTWAVES PIVOTING THROUGH THE REGION WILL
PERIODICALLY BOOST INVERSION HEIGHTS AND BRING SLUGS OF DEEPER
MOISTURE THROUGH WHICH WILL ENHANCE THE SHOWER ACTIVITY.
THE FREEZING LEVEL WILL BE AROUND 1500 FT SO WOULD EXPECT TO SEE A
MIXTURE OF RAIN/SNOW/GRAUPEL... ESPECIALLY INLAND FROM WARMING
EFFECTS OF LK MI INCLUDING THE HWY 131 CORRIDOR. SOME ACCUMULATING
WET SNOW LOOKS TO BE A REALISTIC THREAT FOR WEDNESDAY THROUGH
THURSDAY NIGHT WHEN BOTH THE GFS AND ECMWF INDICATE THAT WE WILL BE
ON THE CYCLONIC SHEAR SIDE OF THE UPPER JET CORE WHICH WILL BE
POSITIONED TO OUR WEST AND SOUTH.
WARM ADVECTION IS CURRENTLY PROGGED FOR NEXT SATURDAY AHEAD OF A
SYSTEM DROPPING DOWN FROM THE NORTHWEST. THIS WOULD END THE LAKE
EFFECT TEMPORARILY BUT THE CHANCE OF RAIN WILL CONTINUE DUE TO
ISENTROPIC LIFT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 146 PM EDT SUN OCT 20 2013
VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THIS EVENING EVEN
THOUGH A FEW RAIN SHOWERS WILL BE MOVING IN. THERE IS THE OUTSIDE
CHANCE THAT A THUNDERSTORM COULD MOVE THROUGH THE TAF SITES AFTER
00Z...BUT THESE ARE EXPECTED TO BE VERY ISOLATED AND THEY WERE
NOT PUT IN THE TAFS AT THIS POINT.
A STRONG COLD FRONT WILL APPROACH TOWARD DAYBREAK MON. THERE
SHOULD BE A PERIOD OF MVFR AS THIS FRONT COMES THROUGH...ALONG
WITH SCATTERED SHOWERS. THIS SHOULD IMPROVE TO VFR TOWARD MID DAY
MON.
WINDS WILL BE INCREASING THIS EVENING AND CONTINUE INTO MON AS THE
FRONT COMES THROUGH. SSW WINDS AROUND 15 KTS WILL SHIFT TO THE
WEST TOWARD DAYBREAK.
PILOTS SHOULD ALSO KEEP IN MIND THE RISK OF IN-CLOUD ICING INTO
MON. FREEZING LEVELS WILL BE DROPPING AFTER 12Z BEHIND THE COLD
FRONT...TO 2K TO 3K FEET. CLOUD TOPS WILL BE AROUND 6K FEET. IN-
CLOUD TEMPS WILL CONTINUE TO BECOME MORE FAVORABLE FOR ICING
BEYOND 18Z MON.
&&
.MARINE...
ISSUED AT 1205 PM EDT SUN OCT 20 2013
I CONTINUED THE SMALL CRAFT ADVISORY INTO THIS EVENING AND THE
GALE WARNING TONIGHT AND MONDAY. IT SEEMS TO ME THROUGH THAT THE
WINDS WILL START TO DIMINISH MONDAY AFTERNOON. WE MAY BE ABLE TO
DROP THE GALES BY MID AFTERNOON MONDAY.
WATER SPOUTS WILL BE AN ISSUE ONCE THE WINDS DIMINISH BELOW
GALES... SO I CONTINUED THE WATER SPOUTS IN THE NEAR SHORE FOR
MONDAY NIGHT.
&&
.HYDROLOGY...
ISSUED AT 344 AM EDT SUN OCT 20 2013
WE ARE NOT ANTICIPATING ANY HYDROLOGY ISSUES IN THE NEXT WEEK. THE
MAJORITY OF THE PCPN OVER THE NEXT WEEK WILL BE IN THE FORM OF
SCATTERED SHOWERS. THIS TYPE OF PATTERN IS NOT CONDUCIVE FOR HEAVY
RAINFALL WITH PRECIPITABLE WATERS RUNNING AROUND AVERAGE FOR THIS
TIME OF YEAR. MOST LOCATIONS WILL NOT SEE PCPN OVER HALF AN INCH
OVER THE NEXT FEW DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ844>849.
GALE WARNING FROM 8 PM THIS EVENING TO 5 AM EDT TUESDAY FOR
LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...JK
HYDROLOGY...NJJ
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1205 PM EDT SUN OCT 20 2013
LATEST UPDATE...
UPDATE/MARINE
.SYNOPSIS...
ISSUED AT 344 AM EDT SUN OCT 20 2013
INTERVALS OF SHOWERS WILL CONTINUE THROUGH THE MAJORITY OF THE WEEK
THIS WEEK AS A STRONG SURGE OF COLD CANADIAN AIR TAKES HOLD OF THE
AREA. WAVES OF LOW PRESSURE WILL COMBINE WITH LAKE EFFECT TO BRING
THE OCCASIONAL SHOWERS TO THE AREA. COLD ENOUGH AIR IS EXPECTED TO
MOVE IN TO ALLOW FOR SOME SNOW TO MIX IN AT TIMES WITH THE RAIN
SHOWERS. HIGHS WILL LIKELY REMAIN ONLY IN THE 40S MANY TIMES THIS
WEEK.
&&
.UPDATE...
ISSUED AT 1205 PM EDT SUN OCT 20 2013
I ADDED THUNDERSTORMS TO OUR ZONE FORECASTS TONIGHT. AFTER
LOOKING AT THE 1000 J/KG OF MOST UNSTABLE CAPE OVER LAKE MICHIGAN
EARLY THIS EVENING. RAP AND NAM SOUNDINGS THIS EVENING INTO THE
OVERNIGHT SHOW NO INVERSION TO CAPE THE INSTABILITY...WHICH IS
UNLIKE LAST NIGHT WHEN WE HAD THUNDERSTORMS BUT THE INSTABILITY WAS
CAPED AROUND 120000 FT. THE SOUNDINGS GIVE EQUILIBRIUM LEVELS AS
HIGH AS 350000 FT THIS EVENING. THE CAPE IS SKINNY...BUT GIVEN
THE 50 KNOT LOW LEVEL JET THAT POKES INTO OUR SOUTHWEST CWA BETWEEN
8 PM AND 11 PM... PLUS OUR AREA BEING IN THE EXIT REGION OF THE
POLAR JET TONIGHT. THE NAM THUNDERSTORMS PROBABILITY PROG HAS
NUMBERS AS HIGH AS 60 PCT OVER LAKE MICHIGAN AND 40 PCT INLAND
NORTH OF HOLLAND TO US-131 JUST BEFORE MIDNIGHT. THE SPC 03Z SREF
ALSO FORECASTS THUNDERSTORMS OVER LAKE MICHIGAN INTO SOUTHWEST
LOWER MICHIGAN SIMILAR TO THE NAM THUNDERSTORM PROP CHART. ALL OF
THIS TELLS ME WE SHOULD SEE THUNDERSTORMS DEVELOPING OVER LAKE
MICHIGAN EARLY TONIGHT THEY WILL THEN MOVE INLAND DURING THE MID
EVENING HOURS JUST AHEAD OF THE COLD FRONT. DUE TO THE SOUTHWEST
WINDS THE BEST INSTABILITY (AIDED BY THE WARMTH OF LAKE MICHIGAN)
WILL MOSTLY BE NORTH OF A LINE FROM HOLLAND TO ALMA.
I ALSO INCREASED THE POP TONIGHT SINCE THERE IS LITTLE QUESTION
GIVEN THE WARM LAKE AND DYNAMICS PLUS A DECENT SHOT AT DEEP
MOISTURE THAT THERE WILL BE SHOWERS TONIGHT. ANY STORMS MAY HAVE
SMALL HAIL GIVEN THE FREEZING LEVEL BEING BELOW 7000 FT.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 344 AM EDT SUN OCT 20 2013
PCPN TRENDS AND TYPE ARE THE MAIN FOCUS OF THE FCST PACKAGE TODAY.
THE SHOWER ACTIVITY THAT WAS WIDESPREAD ACROSS THE AREA LAST EVENING
IS SCATTERING OUT AND DISSIPATING EARLY THIS MORNING. THIS IS DUE TO
MAINLY THE UPPER FLOW TRANSITIONING TO ANTI-CYCLONIC AS THE LAST
SHORT WAVE IN THIS SEQUENCE IS NOW LIFTING TO THE E/NE THIS MORNING.
WE EXPECT THE SHOWER ACTIVITY TO PRETTY MUCH END FOR A FEW HOURS AS
SHORT WAVE RIDGING BUILDS IN AND WE LOSE THE LOW LEVEL MOISTURE.
SOME BREAKS IN THE CLOUDS WILL BE LIKELY ONCE AGAIN...HOWEVER JUST
AS THE LOW LEVEL MOISTURE MOVES OUT...MID AND HIGH LEVEL MOISTURE
FROM THE NEXT SYSTEM MOVES RIGHT IN.
THE NEXT SYSTEM IN THE SEQUENCE WILL BE BRINGING PCPN TO THE FAR NW
CORNER OF THE CWFA AS EARLY AS LATE THIS AFTERNOON. THIS WAVE IS
CURRENTLY LOCATED NORTH OF LAKE WINNIPEG AND DROPPING SOUTHEAST
QUICKLY. IT WILL MERGE WITH ANOTHER SHORT WAVE COMING INTO THE
DAKOTAS. THE TRACK OF THE SHORT WAVE AND SFC LOW WILL FAVOR THE NRN
SECTION OF THE CWFA FOR THE BEST PCPN CHCS. IT DOES LOOK LIKE THE
ENTIRE CWFA WILL HAVE A CHC OF RAIN AS THE COLD FRONT PASSES THROUGH
THE AREA VERY LATE TONIGHT AND MON MORNING.
THE THREAT OF LAKE EFFECT RAIN SHOWERS WILL BE THERE ON MON WITH
DELTA T/S EXPECTING TO BE AROUND 20C. THE THREAT DOES NOT LOOK TO BE
VERY BIG HOWEVER AS THE DRY SLOT WILL AFFECT THE AREA BEHIND THE
FRONT. MOISTURE PROFILES INDICATE THAT THEY WILL BE DEEP ENOUGH FOR
SOME PCPN TO BE GENERATED AS THE DGZ WILL BARELY BE SATURATED.
INVERSION HEIGHTS ARE SOMEWHAT LOW AS THE UPPER LOW AND CORE OF THE
CYCLONIC FLOW STAYS MAINLY NORTH OF THE AREA.
THE THREAT OF SHOWERS WILL CONTINUE TO BE POSSIBLE MON NIGHT AND
EARLY TUE. THIS IS THE PERIOD WHEN IT LOOKS LIKE WE WILL SEE A
POTENTIAL OF PCPN MIXING WITH OR CHANGING TO SNOW WITH H850 TEMPS
DROPPING TO ALMOST -7C AND FREEZING LEVELS DROPPING BELOW 2000 FT.
THE BEST POTENTIAL OF SEEING SOME SNOW WILL BE UP ACROSS CENTRAL
LOWER MICHIGAN AT THE HIGHER ELEVATIONS. IN ADDITION TO THE
POSSIBILITY OF SNOW...WE CAN NOT RULE OUT THUNDER ALONG THE
LAKESHORE WITH LAKE MODIFIED PARCELS GENERATING OVER 1000 J/KG OF
CAPE AND PARCELS REACHING TO -20C ISOTHERM. WATERSPOUTS WILL ALSO
REMAIN POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 344 AM EDT SUN OCT 20 2013
THERE SEEMS TO BE NO END IN SIGHT TO THE COOL AND UNSETTLED PATTERN
AS DEEP UPPER TROUGHING PERSISTS OVER THE GREAT LAKES REGION THROUGH
ALL OF NEXT WEEK. TEMPERATURES WILL AVERAGE AROUND 10 DEGREES BELOW
NORMAL.
H8 TEMPS ARE PROGGED TO REMAIN RIGHT AROUND -6C THROUGH MOST OF THE
WEEK CREATING EXTREME LAKE INSTABILITY WITH DELTA T/S IN EXCESS OF
20C. OCCASIONAL SHORTWAVES PIVOTING THROUGH THE REGION WILL
PERIODICALLY BOOST INVERSION HEIGHTS AND BRING SLUGS OF DEEPER
MOISTURE THROUGH WHICH WILL ENHANCE THE SHOWER ACTIVITY.
THE FREEZING LEVEL WILL BE AROUND 1500 FT SO WOULD EXPECT TO SEE A
MIXTURE OF RAIN/SNOW/GRAUPEL... ESPECIALLY INLAND FROM WARMING
EFFECTS OF LK MI INCLUDING THE HWY 131 CORRIDOR. SOME ACCUMULATING
WET SNOW LOOKS TO BE A REALISTIC THREAT FOR WEDNESDAY THROUGH
THURSDAY NIGHT WHEN BOTH THE GFS AND ECMWF INDICATE THAT WE WILL BE
ON THE CYCLONIC SHEAR SIDE OF THE UPPER JET CORE WHICH WILL BE
POSITIONED TO OUR WEST AND SOUTH.
WARM ADVECTION IS CURRENTLY PROGGED FOR NEXT SATURDAY AHEAD OF A
SYSTEM DROPPING DOWN FROM THE NORTHWEST. THIS WOULD END THE LAKE
EFFECT TEMPORARILY BUT THE CHANCE OF RAIN WILL CONTINUE DUE TO
ISENTROPIC LIFT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 750 AM EDT SUN OCT 20 2013
HIGH CONFIDENCE EXISTS FOR WIDESPREAD VFR CONDITIONS TODAY. THE
NEXT WEATHER MAKER ARRIVES AFTER 00Z TONIGHT WITH WIDESPREAD
SHOWERS AND MVFR CONDITIONS DEVELOPING AT KMKG AND KGRR BY
03Z-06Z. THE SHOWERS SHOULD SPREAD INLAND OVER THE REST OF THE
AREA AFTER 06Z TONIGHT... ALTHOUGH CONDITIONS SOUTH AND EAST OF
GRR WILL LIKELY REMAIN VFR AS THE SHOWERS SHOULD NOT BE AS HEAVY
AND PERSISTENT AS THEY WILL BE AT KMKG AND KGRR. WINDS WILL
INCREASE OUT OF THE SOUTH TO 10 TO 20 KNOTS LATER THIS AFTERNOON
AND BECOME SOUTHWEST OVERNIGHT.
&&
.MARINE...
ISSUED AT 1205 PM EDT SUN OCT 20 2013
I CONTINUED THE SMALL CRAFT ADVISORY INTO THIS EVENING AND THE
GALE WARNING TONIGHT AND MONDAY. IT SEEMS TO ME THROUGH THAT THE
WINDS WILL START TO DIMINISH MONDAY AFTERNOON. WE MAY BE ABLE TO
DROP THE GALES BY MID AFTERNOON MONDAY.
WATER SPOUTS WILL BE AN ISSUE ONCE THE WINDS DIMINISH BELOW
GALES... SO I CONTINUED THE WATER SPOUTS IN THE NEAR SHORE FOR
MONDAY NIGHT.
&&
.HYDROLOGY...
ISSUED AT 344 AM EDT SUN OCT 20 2013
WE ARE NOT ANTICIPATING ANY HYDROLOGY ISSUES IN THE NEXT WEEK. THE
MAJORITY OF THE PCPN OVER THE NEXT WEEK WILL BE IN THE FORM OF
SCATTERED SHOWERS. THIS TYPE OF PATTERN IS NOT CONDUCIVE FOR HEAVY
RAINFALL WITH PRECIPITABLE WATERS RUNNING AROUND AVERAGE FOR THIS
TIME OF YEAR. MOST LOCATIONS WILL NOT SEE PCPN OVER HALF AN INCH
OVER THE NEXT FEW DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ844>849.
GALE WARNING FROM 8 PM THIS EVENING TO 5 AM EDT TUESDAY FOR
LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...NJJ
MARINE...WDM
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
131 PM CDT SUN OCT 20 2013
.SHORT/LONG TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 433 AM CDT SUN OCT 20 2013
PERSISTENT NORTHWEST FLOW WILL REMAIN IN TACT THROUGHOUT THE
PERIOD...LEADING TO BELOW NORMAL TEMPERATURES AND PERIODIC CHANCES
FOR LIGHT PRECIP. GIVEN THE COLD AIR EXPECTED TO BE IN PLACE...WILL
SEE THE POTENTIAL FOR FROZEN PRECIP CARRY ON THROUGH NEXT WEEK.
ARGUABLY THE MOST INTRIGUING FEATURE IN THE EXTENDED IS THE CLIPPER
SYSTEM CURRENTLY APPROACHING THE UPPER MIDWEST. THE LATEST HIRES
MODELS PORTRAY MORE OF A SOUTHERLY TRACK...SO HAVE BROUGHT THE
HIGHEST POPS AND QPF SOUTH TO REFLECT THIS TREND. HOWEVER...BUFR
FORECAST SOUNDINGS OFF THE RAP ONLY HAVE AROUND AN INCH OF SNOW AT
MORA...AND BRAINERD...WITH LESS AT ALEXANDRIA AND ST CLOUD. THE NAM
IS CONTINUES TO ADVERTISE 4 INCHES AT MORA...BUT THIS IS LIKELY
OVERDONE CONSIDERING THAT ACCORDING TO THE NAM AS OF 5AM 1-2 INCHES
SHOULD HAVE ALREADY FALLEN AT FARGO..AND THEY HAVE YET TO RECEIVE
ANY SNOW. THE MAIN REASON FOR THE SLOW CHANGEOVER SEEMS TO BE THE
LACK OF STRONG FGEN AND FOCUSED VERTICAL MOTION IN THE WAA
REGIME...RATHER GRADUAL ISENTROPIC ASCENT WAS THE DRIVING FORCE
BEHIND THE PRECIP. THROUGHOUT THE MORNING HOURS...THE NAM DOES
INCREASE THE FGEN FORCING...WHILE THE RAP IS WEAKER. AFTER WEEDING
THROUGH THE DIFFERENT SCENARIOS...DO NOT HAVE THE CONFIDENCE IN ANY
SNOWFALL AMOUNTS EXCEEDING 3 INCHES DESPITE THE SOUTHERLY SHIFT IN
QPF. RATHER SHOULD SEE A MODEST BAND OF SNOW TRACK NORTH OF
I-94...WITH PERHAPS AN INCH OR 2 ON GRASSY SURFACES THIS
MORNING...BEFORE TRANSITIONING TO MORE OF RAIN/SNOW OR EVEN ALL RAIN
MIX LATER THIS AFTERNOON AS 1)THE BOUNDARY LAYER WARMS...AND 2) WE
LOSE THE DEEP SATURATION AND TRANSITION TO MORE OF LIGHT
RAIN/DRIZZLE SCENARIO.
BRISK NORTHWEST WINDS WILL FOLLOW ONCE THIS SYSTEM MOVES EASTWARD AS
COOLER AIR AS EVIDENT BY THE -7 TO -10C H850 TEMPS ADVECT ACROSS THE
REGION SUNDAY NIGHT INTO MONDAY. THE NORTHWEST FLOW WILL PERSIST
ACROSS THE REGION...WITH A FEW SHORTWAVES TRACKING DOWN THE POLEWARD
SIDE OF THE JET. THESE WILL INDUCE LOW LEVEL CIRCULATIONS...THE NEXT
OF WHICH IS EXPECTED TO TRACK SOUTHWEST OF THE CWA ALONG THE
MISSOURI RIVER VALLEY MONDAY NIGHT INTO TUESDAY. COLD AIR WILL AGAIN
BE REINFORCED BEHIND THIS SYSTEM...WILL NO WARM UP POTENTIAL IN
SIGHT UNTIL PERHAPS THE END OF THE WEEK AS ANOTHER WAVE MOVES ACROSS
THE REGION. DEPENDING ON THE TRACK OF THIS SYSTEM...THE UPPER
MIDWEST COULD SEE ONE DAY OF WARMER TEMPERATURES...BUT THE GUIDANCE
IS CONSISTENT THAT THIS WILL BE SHORT LIVED AS ANOTHER ARCTIC
AIRMASS WILL FOLLOW BEHIND THIS PASSING WAVE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1259 PM CDT SUN OCT 20 2013
THIS TAF CYCLE HAS PROVED DIFFICULT...WITH A FEW AMENDMENTS/
CORRECTIONS REQUIRED WITHIN MINUTES OF THE INITIAL SET BEING
ISSUED. A DRY SLOT ACROSS SOUTH CENTRAL MN HAS BROUGHT VFR
CONDITIONS THERE TEMPORARILY...BUT IT IS ALREADY BEGINNING TO FILL
BACK IN WITH CLOUDS ON THE BACKSIDE OF THE LOW WHICH ARE ACCELERATING
EASTWARD. CIGS WITHIN THIS AREA OF WRAP AROUND CLOUDS ARE SOLIDLY
MVFR...WITH SOME LOCATIONS AS LOW AS IFR...PARTICULARLY OVER
NORTHEASTERN SOUTH DAKOTA AND WEST CENTRAL MN. FURTHER EAST...SNOW
CONTINUES ACROSS EAST CENTRAL MN WHERE VSBYS REMAIN LESS THAN 1
MILE. THE STEADY PRECIPITATION WILL TAPER OFF EARLY THIS
AFTERNOON WITH THE TAF SITES BECOMING MAINLY SPORADIC -RA OR -DZ
FOR THE REST OF THE AFTERNOON. CONFIDENCE REMAINS QUITE LOW WITH
REGARD TO HOW LOW CIGS WILL BECOME THIS EVENING BEFORE DRIER AIR
ARRIVES FROM EASTERN NORTH DAKOTA. MUCH OF THE GUIDANCE APPEARS
TOO OPTIMISTIC GIVEN CURRENT CONDITIONS SO WILL CONTINUE THE TREND
DOWNWARD INTO EARLY EVENING. THE DRIER AIR SHOULD ERODE THE LOWER
CIGS OVERNIGHT AND MONDAY MORNING.
KMSP...THE SHORT STINT OF VFR CIGS IS OVER FOR NOW. CIGS CONTINUE
TO CRASH TO THE WEST WITH MVFR AND SUB 017 CIGS EXPECTED A LITTLE
LATER THIS AFTERNOON. EVENTUALLY DRIER AIR WILL ERODE THE LOWER
CIGS OVERNIGHT...BUT CONFIDENCE IS QUITE LOW AS TO WHEN THIS WILL
OCCUR.
/OUTLOOK FOR KMSP/
MON NIGHT...VFR. WINDS WNW 5-10 KTS.
TUE...VFR WITH MVFR CIGS POSSIBLE EARLY. WINDS NW AT 10 KTS.
WED...MVFR CIGS POSSIBLE. WINDS NW AT 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...JRB
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
316 PM CDT SUN OCT 20 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 316 PM CDT SUN OCT 20 2013
CHALLENGES THROUGH THE PERIOD INCLUDE LOW END PRECIPITATION CHANCES
AND TEMPERATURES. GFS/NAM/ECMWF/GEM IN REASONABLE AGREEMENT AND
WILL FOLLOW AND BLENDED MODEL SOLUTION.
20 UTC SURFACE ANALYSIS SHOWS THE SURFACE LOW SOUTHWEST OF
MINNEAPOLIS AND MOST OF ITS ASSOCIATED PRECIPITATION ACROSS THE MN
ARROWHEAD INTO NORTHWEST WI. A COUPLE SURFACE OBS ACROSS WEST
CENTRAL MN STILL REPORTING LIGHT RAIN...BUT WITH VISIBILITY OF 10
SM...MOST LIKELY JUST SOME LINGERING SPRINKLES. WILL CONTINUE THIS
DRYING TREND INTO THE EARLY EVENING WITH ONLY SOME 20 POPS ACROSS
THE LAKE OF THE WOODS REGION OVERNIGHT AS THE SURFACE LOW PIVOTS
BACK TO THE NORTH AND ITS INVERTED TROUGH PINWHEELS ABOUT THE
INTERNATIONAL BORDER.
THERE IS ABUNDANT CLOUD COVER UPSTREAM...BUT IT IS MORE CELLULAR
IN NATURE...SO IT/S DIFFICULT TO SAY HOW MUCH CLEARING WILL OCCUR
OVERNIGHT...ESPECIALLY WHEN THE RAP 925 HPA RH SHOWS SATURATED
CONDITIONS THROUGH MONDAY MORNING. WILL SHOW SOME CLEARING WEST OF
THE VALLEY BY 12 UTC MONDAY...BUT THIS MAY BE OVERLY OPTIMISTIC.
EITHER WAY...WITH HIGHS THIS AFTERNOON IN THE 30S...NIGHTTIME
LOWS IN THE 20S SEEM REASONABLE.
BEST CHANCE FOR PRECIPITATION MONDAY WILL CONTINUE ACROSS THE LAKE
OF THE WOODS REGION WITH ALL OTHER AREAS DRY. SHOULD SEE A BIT
MORE SUN TO THE SOUTH AND WEST...BUT COLD AIR MASS WILL KEEP
HIGH TEMPERATURES IN THE 30S. NORTH-NORTHWEST WIND WILL PERSIST...
BUT WITH A WEAKENING PRESSURE GRADIENT...SHOULD BE A BIT LOWER
FROM 10 TO 15 MPH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 316 PM CDT SUN OCT 20 2013
CANADIAN HIGH PRESSURE DIVES SOUTH ACROSS THE NORTHERN PLAINS
TUESDAY AND WEDNESDAY FOR MOSTLY DRY CONDITIONS. HOWEVER...
PERSISTENT CYCLONIC FLOW ALOFT COMBINED WITH HIGHER MID-LEVEL
MOISTURE WILL RESULT IN QUITE A BIT OF CLOUDS. MID-LEVEL THERMAL
RIDGE WILL NUDGE EASTWARD...ALLOWING FOR A LITTLE WARMING EACH
DAY...SO THAT HIGHS BY WEDNESDAY SHOULD APPROACH 40 DEGREES. THIS
IS STILL 10 TO 15 DEGREES BELOW MID-LATE OCTOBER NORMALS.
WED NIGHT-SUNDAY...NORTHWEST FLOW ALOFT THOUGH THE PERIOD. 12Z
MODELS ARE IN GOOD AGREEMENT INITIALLY...BUT QUICKLY DISAGREE WITH A
STRONGER WAVE FRIDAY INTO SUNDAY. THE GFS/GEM ARE MUCH QUICKER AND
FURTHER WEST WITH THIS WAVE THAN THE ECMWF. THE GFS/GEM BRING PRECIP
INTO NORTHWEST MINNESOTA WITH THIS FEATURE...WHILE THE ECMWF IS
BASICALLY DRY THROUGH THE PERIOD. TEMPERATURES WOULD ALSO BE
AFFECTED WITH EXACTLY WHERE THIS WAVE TRACKS. THE BLEND OF MODELS IS
LIKELY THE BEST COURSE OF ACTION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 117 PM CDT SUN OCT 20 2013
THE GENERAL TREND WILL BE IMPROVING CONDITIONS THROUGH THE PERIOD.
FOLLOWED THE 15Z RAP FOR GUIDANCE ON TIMING THE IMPROVEMENT. SITES
ALONG AND WEST OF THE VALLEY EXPECTED TO EVENTUALLY BE VFR BY LATER
THIS EVENING...WHILE SITES EAST OF THE VALLEY WILL LIKELY REMAIN
MVFR. GUSTY NORTHERLY WINDS THIS AFTERNOON WILL SUBSIDE A BIT
TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...ROGERS
LONG TERM...ROGERS/TG
AVIATION...TG
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
117 PM CDT SUN OCT 20 2013
.UPDATE...
ISSUED AT 117 PM CDT SUN OCT 20 2013
WILL ALLOW THE REMAINING COUNTIES IN THE WINTER WEATHER ADVISORY
TO EXPIRE AT 1 PM CDT. PERIODS OF LIGHT RAIN OR SNOW ARE POSSIBLE
THIS AFTERNOON MAINLY ACROSS SOUTHEAST ND INTO WEST CENTRAL MN...
BUT NOT EXPECTING MUCH IF ANY ADDITIONAL SNOW ACCUMULATION.
VISIBILITIES HAVE RISEN ABOVE A MILE AND SURFACE TEMPERATURES NOW
IN THE MID TO UPPER 30S ARE HELPING PRECIPITATION CHANGE BACK TO
RAIN. SOME SLICK SPOTS ON AREA ROADWAYS STILL POSSIBLE...SO
MOTORISTS SHOULD DRIVE WITH CAUTION.
CLOUDS ARE STARTING TO BREAK ACROSS THE DEVILS LAKE BASIN AND
PORTIONS OF THE FAR NORTHERN VALLEY...BUT WITH LOW CONVECTIVE
TEMPERATURES AND CYCLONIC FLOW ALOFT...THINK THERE SHOULD BE A
FAIR AMOUNT OF CU TO FILL BACK-IN. NORTHERLY WINDS NOW INCREASING
TO NEAR 20 KTS ALONG AND WEST OF THE RED RIVER VALLEY AND THIS IS
HANDLED WELL IN CURRENT GRIDS. REST OF THE FORECAST IN GOOD SHAPE
WITH NO CHANGES AT THIS TIME.
UPDATE ISSUED AT 1023 AM CDT SUN OCT 20 2013
MAIN QUESTION THIS MORNING IS WHAT TO DO WITH ONGOING WINTER
WEATHER ADVISORY. AREA WEBCAMS SHOW WET ROADWAYS WITH LITTLE TO
NO SNOW ACCUMULATION. THE MAJORITY OF MORNING SNOW REPORTS HAVE
BEEN A HALF INCH OR LESS ON GRASSY SURFACES AND DO NOT ANTICIPATE
MUCH MORE ACCUMULATION WITH CURRENT VISIBILITIES ABOVE ONE MILE.
THE EXCEPTION BEING IN THE PARK RAPIDS/WADENA/DETROIT LAKES AREA
WHERE SOME ACCUMULATION ON ROADWAYS IS VISIBLE ON MNDOT WEBCAMS.
RAP/HRRR/LOCAL WRF SUGGEST THESE AREAS STAND THE BEST CHANCE OF
ADDITIONAL SNOW THROUGH THE MORNING AS THE SURFACE LOW RAPIDLY
MOVES INTO SOUTH-CENTRAL MN. ANOTHER 1-2 INCHES IS NOT OUT OF THE
QUESTION. ALL THIS SAID...WILL CANCEL THE ADVISORY ACROSS ALL OF
EASTERN ND AND MOST OF NORTHWEST MN...LEAVING IT INTACT FOR AREAS
SOUTH AND EAST OF A LINE FROM FERGUS FALLS TO MAHNOMEN TO JUST
SOUTH OF BEMIDJI. ROADS MAY STILL BE SLICK...HOWEVER...WITH
SURFACE TEMPERATURES AT OR JUST ABOVE FREEZING. ADJUSTED POPS TO
FOLLOW THIS THINKING...BUT REST OF FORECAST IS IN GOOD SHAPE WITH
NO MAJOR CHANGES AT THIS TIME.
UPDATE ISSUED AT 635 AM CDT SUN OCT 20 2013
THE CHALLENGE FOR THIS UPDATE WILL BE WINTER WEATHER HEADLINES.
THIS VERY CHALLENGING EVENT CONTINUES TO UNFOLD...WITH SNOW NOW
OCCURRING AT THE OFFICE HERE AND SNOW TO THE NORTH OF US. IT IS
STILL RAIN IN THE FARGO AREA...BUT OBS JUST EAST OF FARGO INTO THE
PKD/BJI/FSE AREA ARE ALL SNOW. OVER THE NEXT FEW HOURS...COLDER
AIR SHOULD CHANGE RAIN TO SNOW IN THE FARGO AREA. WE HAVE HAD A
REPORT OF AROUND AN INCH IN NE ND...WITH TEMPS AROUND FREEZING.
NOT EXPECTING TOO MUCH SNOW ACCUMULATION FOR MOST OF ND
COUNTIES WITH WARM GROUND TEMPS AND FAIRLY WEAK SNOW RATES...BUT
AN INCH OF SNOW AND SOME ICY ROADS POSSIBLE THIS MORNING. EXPECT
THE 1-2 INCH AMOUNTS IN THE HIGHER TERRAIN AWAY FROM THE VALLEY
FLOOR IN ND AND MN. THERE SHOULD BE A BETTER CHANCE AT A FEW INCHES
OF SNOW FROM MAHNOMEN TO PKD...AND THE ADVY LOOKS GOOD HERE. CAN/T
EVEN RULE OUT AN INCH OR SO FROM FSE EAST TO BJI...BUT FOR NOW
WON/T EXPAND ADVISORY BUT MONITOR. THEREFORE...FOR NOW WON/T
ADJUST THE ADVISORY AND WE WILL CONTINUE TO MONITOR THROUGH THE
MORNING FOR ANY NEEDED CHANGES.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 345 AM CDT SUN OCT 20 2013
THE MAIN CHALLENGE THIS MORNING WILL BE CURRENT HEADLINES AND
PRECIP FOR THE REST OF TONIGHT AND SUNDAY. MODELS HAVE COME INTO
BETTER AGREEMENT WITH THE OVERALL TRACK OF THE QPF BAND...BUT
STILL SOME DIFFERENCES IN THERMAL FIELDS EVEN WITH MESOSCALE
MODELS. THEREFORE...STILL SOME QUESTIONS AS TO WHO ACTUALLY GETS
SOME ACCUMULATION.
FOR THE NEAR TERM...GETTING JUST PLAIN RAIN AT THE OFFICE AND THIS
WILL LIMIT ANY SNOW ACCUMS AT LEAST INITIALLY. THERE IS SOME MINOR
ACCUMS LIKELY NEAR LANGDON SINCE THEY HAVE BEEN 32 FOR THE PAST
FEW HOURS AND VSBYS BELOW 3SM. ALSO...WHEN LOOKING AT DUAL POL
DATA...IT SEEMS THE CHANGEOVER TO SNOW AROUND AND NORTH OF GFK
SHOULD OCCUR BY 9Z. WE WILL MONITOR CLOSELY THROUGH THE MORNING
HOURS...AND MAY NEED TO CANCEL PORTIONS OF THE ADVISORY IF SNOW
ACCUMS DO NOT OCCUR. TEMPS WILL STILL FALL BELOW FREEZING THROUGH
THE PRE DAWN HOURS IN THE NORTHERN VALLEY...AND SOME SLICK SPOTS
ON ROADS ARE POSSIBLE.
EARLY THIS MORNING AND TODAY...EXPECT MOST OF THE PRECIPITATION
TO HAVE CHANGED OVER TO SNOW BY 12Z...EXCEPT PERHAPS IN THE FAR
SOUTH WHERE MAINLY RAIN SHOULD FALL. THERE SHOULD BE A TIME WHERE
SOME SNOW ACCUMULATES MAINLY NORTH OF A DEVILS LAKE TO FARGO TO
PARK RAPIDS LINE FROM AROUND 10Z-15Z. THERE COULD BE A FEW REPORTS
OF AN INCH...PERHAPS 2...BUT WITH WARM BOUNDARY LAYER TEMPS
LIMITING SNOW FALL INITIALLY...ACCUMS SHOULD BE LIGHT. WE WILL
CONTINUE TO MONITOR ANY EXPECTED CHANGES IN THIS THINKING...SINCE
ELEVATION WILL PLAY A ROLE IN SNOW ACCUMS AS THE BAND PROGRESSES
INTO MN EARLY THIS MORNING. THERE IS ALSO AN AREA IN EASTERN POLK
COUNTY INTO SOUTHERN CLEARWATER/BELTRAMI COUNTIES WHERE TEMPS ARE
BELOW FREEZING. IF RAIN OCCURS HERE INITIALLY...COULD BE SOME
ICING...ALTHOUGH LOOKING AT RWIS SITES SHOWS ROAD SFC TEMPS ARE IN
THE MID 30S...SO FOR NOW WON/T EXTEND ADVISORY EAST BUT WILL
MONITOR. NORTHERLY WINDS WILL INCREASE BEHIND THE FRONT AND GUST
OVER 30 MPH IN THE VALLEY...AND IT WILL BE A BLUSTERY DAY. AFTER
18Z...EXPECT MORE OF A RAIN/SNOW MIX IN THE EAST AND ANY POTENTIAL
FOR ACCUMS SHOULD END.
FOR TONIGHT AND MONDAY...EXPECT THE POTENTIAL FOR SOME WRAPAROUND
LIGHT SNOWS MAINLY IN THE EAST. TEMPS WILL CONTINUE TO BE VERY
COLD...WITH WINDS FAIRLY STRONG TONIGHT AND MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 AM CDT SUN OCT 20 2013
FOR MONDAY NIGHT THROUGH TUE NIGHT...IT SHOULD BE MAINLY DRY WITH
PERHAPS A FEW LIGHT SNOW SHOWERS IN THE FAR NORTHEAST MON NIGHT.
IT WILL REMAIN COLD WITH TEMPS WELL BELOW NORMAL.
FOR WEDNESDAY-SATURDAY...LITTLE CHANGE IN THE LONGWAVE PATTERN IS
ANTICIPATED THROUGH NEXT WEEKEND. WITH STRONG POSITIVE 500 MB HEIGHT
ANOMALIES INTO THE NORTHEAST PACIFIC AND TROUGHING INTO THE EASTERN
CONUS...THE NORTHERN PLAINS WILL REMAIN UNDER CHILLY NORTHWEST FLOW
ALOFT. SHORTWAVE TROUGHS RIDING THE PERIPHERY OF THE WESTERN CONUS
RIDGE WILL DIVE SOUTHWARD...ALLOWING REINFORCING SURGES OF COOL AIR
TO SPILL INTO THE REGION...WITH DAY-TO-DAY TEMP VARIATIONS DEPENDENT ON
THE TIMING OF THESE WAVES. HOWEVER...TEMPS LOOK TO REMAIN PRIMARILY
BELOW NORMAL. NO SIGNIFICANT PRECIPITATION IS EXPECTED...WITH ONLY
LOW CHANCES FOR SOME LIGHT RAIN/SNOW ASSOCIATED WITH ANY PROGRESSIVE
SHORTWAVE TROUGHS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 117 PM CDT SUN OCT 20 2013
THE GENERAL TREND WILL BE IMPROVING CONDITIONS THROUGH THE PERIOD.
FOLLOWED THE 15Z RAP FOR GUIDANCE ON TIMING THE IMPROVEMENT. SITES
ALONG AND WEST OF THE VALLEY EXPECTED TO EVENTUALLY BE VFR BY LATER
THIS EVENING...WHILE SITES EAST OF THE VALLEY WILL LIKELY REMAIN
MVFR. GUSTY NORTHERLY WINDS THIS AFTERNOON WILL SUBSIDE A BIT
TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...DK
LONG TERM...DK/MAKOWSKI
AVIATION...TG