Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/17/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
520 PM MST FRI OCT 16 2015
.SYNOPSIS...
LOW PRESSURE WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE
REGION THROUGH THE WEEKEND...WITH THE POTENTIAL FOR LOCALLY HEAVY
RAIN AND GUSTY WINDS FROM THE STRONGEST STORMS. AFTER A BREAK ON
MONDAY...A SECOND PACIFIC LOW PRESSURE SYSTEM WILL BRING ANOTHER
CHANCE FOR RAIN AND COOLER TEMPERATURES DURING THE MIDDLE PORTION OF
NEXT WEEK...WITH A DRYING TREND FORECAST FOR THE END OF NEXT WEEK.
&&
.DISCUSSION...
/ISSUED 110 PM MST 16 OCTOBER 2015/
TONIGHT THROUGH SATURDAY NIGHT... LATEST SATELLITE AND RADAR LOOPS
ARE SHOWING THE DEVELOPMENT OF SHOWERS AND A FEW THUNDERSTORMS
ACROSS WESTERN AND EXTREME SOUTHERN ARIZONA...AS THE UPPER LOW THAT
BROUGHT LOCALLY HEAVY RAIN AND FLASH FLOODING TO PARTS OF SOUTHERN
CA BEGINS TO MOVE ACROSS SOUTH-CENTRAL CA. THE LATEST HRRR AND 4KM
NAM HIGH-RES MODELS CONTINUE TO SHOW THE DEVELOPMENT OF MORE
SHOWER/THUNDERSTORM ACTIVITY ACROSS SOUTH-CENTRAL ARIZONA LATER THIS
AFTERNOON AND EVENING...BEING TRIGGERED BY A JET MAX/SHORTWAVE THAT
CAN BE SEEN ON WV SATELLITE IMAGERY APPROACHING THE REGION FROM THE
SW...AS IT ROTATES AROUND THE MAIN UPPER-LEVEL TROF. AS FAR AS THE
POTENTIAL FOR FLASH FLOODING/SEVERE WEATHER IS CONCERNED...THE
LATEST SPC SREF FORECAST CONTINUES TO SHOW 0-6KM BULK SHEAR VALUES
ONLY RISING INTO THE 20-25KT RANGE THIS EVENING...WITH MUCAPES
VALUES REMAINING IN THE 500-1000 J/KG RANGE. THUS...IT APPEARS THAT
CHANCES FOR SEVERE STORMS APPEAR TO BE ON THE LOW SIDE...WITH GUSTY
WINDS AND HAIL BEING THE MAIN THREAT. HEAVY RAIN APPEARS TO BE MORE
OF A THREAT...WITH PWATS IN THE 1.00-1.50 INCH RANGE...WHICH IS 2-4
SD ABOVE THE MEAN FOR THIS TIME OF YEAR. ALTHOUGH FAIRLY RAPID STORM
MOTION SHOULD LIMIT RAINFALL AMOUNTS IN MOST CASES...TRAINING OF
STORMS IS POSSIBLE DUE TO FAIRLY UNIDIRECTIONAL FLOW THROUGH THE
COLUMN...WHICH COULD LOCALLY ENHANCE RAINFALL AMOUNTS.
ANOTHER...WEAKER SHORTWAVE WILL MOVE THROUGH THE AREA ON SATURDAY.
THERMODYNAMIC PARAMETERS AREN`T QUITE AS FAVORABLE FOR DEEP
CONVECTION ON SATURDAY BUT STILL IMPRESSIVE ENOUGH TO WARRANT POPS
THAT ARE WELL ABOVE CLIMO FOR MID OCTOBER. MUCH LIKE TODAY...IT
WOULD APPEAR SATURDAY AFTERNOON/EVENING WILL BE MORE ACTIVE THAN
SATURDAY MORNING ALTHOUGH MID LEVEL DRY ADVECTION WILL ALREADY BE
UNDERWAY BY THIS POINT AND AREAL COVERAGE SHOULD BE MUCH LESS THAN
FRIDAY.
SUNDAY THROUGH FRIDAY...
THE FORECAST FOR SUNDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK
WILL REMAIN RATHER UNSETTLED. ON SUNDAY...THE AFOREMENTIONED UPPER
LOW WILL BE SHIFTING OFF TO THE EAST OF OUR CWA...WITH RAINFALL
CHANCES ENDING FROM WEST TO EAST. AFTER A DRY DRY ON MONDAY AS
ANOTHER UPPER TROF PASSES OFF WELL TO OUR NORTH...THERE IS GROWING
CONSENSUS BETWEEN THE GLOBAL MODEL SUITES...AND MANY OF THEIR
RESPECTIVE MEMBERS...THAT A RATHER DEEP UPPER LOW WILL DROP
SOUTHEASTWARD INTO THE DESERT SW. ALTHOUGH AVAILABLE MOISTURE VALUES
WILL BE LESS THEN HAT WE ARE SEEING WITH THE CURRENT LOW CENTER THIS
IS AFFECTING OUR REGION...MUCH COLDER AIR ALOFT (500MB TEMPS IN THE
-16 TO -18C RANGE) AND STRONGER WINDS THROUGH THE COLUMN SHOULD
PROVIDE GREATER LIFT FOR SHOWER/THUNDERSTORM DEVELOPMENT.
THUS...HAVE DECIDED TO RAISE POPS AND COOL TEMPS DURING THIS
PERIOD...WITH LOWER DESERT HIGHS LIKELY FALLING INTO THE LOW-MID 80
RANGE BY WEDNESDAY. NEXT THURSDAY AND FRIDAY WILL LIKELY SEE
SOMEWHAT WARMER AND DRIER CONDITIONS AS THE UPPER LOW MOVES OFF TO
THE NORTHEAST.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
INCREASING MID/HIGH CLOUDS THROUGH THIS AFTERNOON WILL GRADUALLY
LOWER WITH 8-10K FT CIGS DEVELOPING LATER THIS AFTERNOON/EARLY
EVENING. RAIN AND THUNDERSTORM CHANCES WILL CONTINUE THROUGH 04Z
WITH ISOLATED THUNDERSTORMS PRODUCING LOCALLY GUSTY WINDS 20 TO 25
KTS AND POSSIBLE LOCALLY REDUCED VISIBILITY FROM BLOWING DUST.
LOCATIONS AROUND PHOENIX AND EASTWARD WILL BE IMPACTED THROUGH ABOUT
04Z BEFORE GREATLY IMPROVING. HAVE KEPT VCTS FOR ALL PHOENIX TAF
SITES.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
RAIN CHANCES WILL REMAIN MOSTLY ACROSS ARIZONA WITH SOME LIGHT
SHOWER ACTIVITY NEAR KBLH. CIGS AROUND 10K FT WILL LIKELY PERSIST
THROUGH THE AFTERNOON BEFORE LIFTING HIGHER THIS EVENING. EXPECTING
WINDS TO REMAIN MOSTLY CALM THROUGH THE EVENING HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UNSETTLED WEATHER EARLY NEXT WEEK WILL SLOWLY TRANSITION TO DRIER
CONDITIONS WITH SEVERAL DISTURBANCES PASSING THROUGH THE DISTRICT.
LIGHTER SHOWERS WILL FAVOR HIGHER TERRAIN LOCATIONS OF EASTERN
ARIZONA. AFTERNOON HUMIDITY VALUES IN A 25 TO 35 PERCENT RANGE EARLY
IN THE WEEK WILL ONLY DECREASE TO A 15 TO 25 PERCENT RANGE BY THE
MIDDLE AND END OF NEXT WEEK. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. A FEW STRONGER NORTHERLY WIND GUSTS DOWN THE LOWER
COLORADO RIVER VALLEY WILL BE POSSIBLE TUESDAY AND WEDNESDAY
AFTERNOON. OTHERWISE...WINDS WILL GENERALLY BE LIGHT AND NOT A FIRE
WEATHER IMPACT.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/LEINS
AVIATION...DEWEY
FIRE WEATHER...DEWEY
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
325 PM MST THU OCT 15 2015
...UPDATED AVIATION AND FIRE WEATHER...
.SYNOPSIS...
LOW PRESSURE...MOVING SLOWLY INLAND FROM THE PACIFIC IS EXPECTED TO
MOVE SLOWLY ACROSS THE REGION OVER THE NEXT FEW DAYS. SHOWER AND
THUNDERSTORM CHANCES ARE EXPECTED TO INCREASE FROM WEST TO EAST
TONIGHT AND FRIDAY...WITH THE BEST CHANCES FOR MEASURABLE RAINFALL
BEING FROM LATE FRIDAY INTO EARLY SATURDAY. AFTER A BIT OF A BREAK
FROM LATE SATURDAY INTO EARLY SUNDAY...A SECOND LOW CENTER IS THEN
EXPECTED TO BRING ANOTHER CHANCE FOR SHOWERS LATE SUNDAY. A SLOW
DRYING TREND WILL COMMENCE EARLY NEXT WEEK AS HIGH PRESSURE ATTEMPTS
TO BUILD BACK INTO THE REGION.
&&
.DISCUSSION...
TONIGHT THROUGH SATURDAY... THE UPPER LOW...WHICH HAS BROUGHT
SHOWERS AND A FEW THUNDERSTORMS TO PARTS OF SE CA TODAY IS NOW
BEGINNING TO MAKE LANDFALL ALONG THE SOUTHERN CA COAST NEAR POINT
CONCEPTION. THE LATEST MODEL SUITES ARE NOW SHOWING THAT THIS LOW
WILL MOVE VERY SLOWLY EASTWARD AND WEAKEN OVER THE NEXT 48
HOURS...NOT REACHING THE LOWER COLORADO RIVER VALLEY UNTIL LATE
MORNING ON SATURDAY. IT IS THEN FORECAST TO WEAKEN FURTHER INTO AN
OPEN WAVE...AND ACCELERATE EASTWARD ACROSS AZ FROM SATURDAY
AFTERNOON INTO EARLY SUNDAY AS THE NEXT UPSTREAM SHORTWAVE ACTS AS
A KICKER. AHEAD OF THIS LOW...DEEP SOUTHERLY FLOW CONTINUES TO PULL
MOISTURE NORTHWARD INTO THE REGION FROM THE SUBTROPICS. EMBEDDED
SHORTWAVES IN THIS SOUTHERLY FLOW ARE PROVIDING THE TRIGGER FOR
SHOWER/THUNDERSTORM DEVELOPMENT. THE 1ST SHORTWAVE...NOW
MOVING NORTHWARD INTO SOUTHERN NV...PRODUCED WIDESPREAD
SHOWER/THUNDERSTORM ACTIVITY ACROSS SE CA EARLY THIS MORNING. A
2ND WEAKER SHORTWAVE IS NOW TRIGGERING SHOWERS ACROSS PARTS OF SE
AZ. THE LATEST HRRR HIGH-RES MODEL RUN IS SHOWING THAT ISOLATED-
SCATTERED SHOWERS DEVELOPING AND SPREADING NORTHWARD AND EASTWARD
ACROSS SW AND SOUTH-CENTRAL AZ THROUGH THE REMAINDER OF THIS
AFTERNOON AND EVENING. THUNDERSTORM ACTIVITY APPEARS
ISOLATED AT BEST...AS THE AIRMASS REMAINS RATHER STABLE WITH 0-6
KM BULK SHEAR REMAINING MAINLY AOB 30 KTS...AND CAPE MAINLY AOB 500
J/KG.
FRIDAY AFTERNOON AND FRIDAY NIGHT LOOKS LIKE IT BE A MORE ACTIVE
PERIOD...AT LEAST ACROSS SW AND SOUTH-CENTRAL AZ AS THE UPPER
LOW/TROF APPROACHES FROM THE WEST. ALTHOUGH SHOWER ACTIVITY WILL
LIKELY BE FAIRLY WIDESPREAD ACROSS THE REGION...THUNDERSTORM
ACTIVITY WILL LIKELY BE LIMITED BY THE FACT THAT THE UPPER TROF WILL
BE WEAKENING AS IT APPROACHES...REDUCING THE AMOUNT OF WIND SHEAR
THROUGH THE COLUMN AND ALLOWING TEMPERATURES TO WARM A BIT ALOFT
NEAR THE UPPER LOW CENTER. HOWEVER...WITH CAPE VALUES RISING INTO
THE 500-1000 J/KG RANGE AND 0-6 KM BULK SHEAR APPROACHING 30
KTS...THE DEVELOPMENT OF A FEW SEVERE STORMS CANNOT BE RULED
OUT...ESPECIALLY IN/NEAR LOCATIONS THAT SEE BREAKS IN THE OVERCAST.
AS FAR AS TEMPERATURES ARE CONCERNED...A COOLING TREND IS STILL
EXPECTED ON FRIDAY AND SATURDAY DUE TO COOLER AIR ALOFT...INCREASED
CLOUDINESS...AND SHOWER ACTIVITY.
SUNDAY THROUGH WEDNESDAY...
FORECAST CONFIDENCE DURING THIS PERIOD CURRENTLY IS QUITE LOW...DUE
TO DIFFERENCES BETWEEN THE GLOBAL MODEL SUITES AND RUN-TO-RUN
DIFFERENCES WITHIN EACH MODEL SUITE CONCERNING THE DEVELOPMENT AND
MOVEMENT OF THE NEXT TWO UPPER LOW CENTERS THAT WILL BE AFFECTING
THE REGION DURING THIS PERIOD. THE 1ST UPPER LOW...WHICH IS EXPECTED
TO MOVE EASTWARD ACROSS THE GREAT BASIN ON SUNDAY AND MONDAY...IS
EXPECTED TO BRING MORE CHANCES FOR RAINFALL ACROSS CENTRAL AND
NORTHERN AZ...WITH THE BEST CHANCES LIKELY REMAINING NORTH OF OUR
CWA. THE SECOND UPPER LOW CENTER IS THEN FORECAST TO DROP
SOUTHEASTWARD ACROSS SE CA INTO NW MEXICO ON TUE AND WED. AT THIS
POINT...HAVE JUST LEFT OUR CURRENT MID AND LONG-RANGE POPS
ALONE...WHICH ARE NOW MAINLY IN THE SLIGHT CHANCE RANGE SUNDAY AND
MONDAY...THEN DWINDLE OFF AFTERWARDS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
MID/HIGH CLOUDS WILL INCREASE THROUGH TONIGHT...WITH CIGS FALLING AS
LOW AS 10K FT. PERIODIC VIRGA AND POSSIBLY A FEW LIGHT SHOWERS COULD
AFFECT TERMINALS...HOWEVER IMPACTS WOULD BE MINIMAL. SFC WINDS HAVE
MAINTAINED AN EASTERLY COMPONENT...HOWEVER SOME MEASURE OF A WEST
DRIFT WILL BE POSSIBLE LATER IN THE EVENING. CONFIDENCE IS ONLY LOW
TO MODERATE ON WIND SHIFTS. MORE CONCENTRATED SHOWERS AND EMBEDDED
THUNDERSTORMS MAY APPROACH CNTRL ARIZONA FRIDAY AFTERNOON.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SHOWERS AND EMBEDDED STORMS FORMING OVER THE BAJA SPINE WILL IMPACT
SOUTHEAST CALIFORNIA TERMINALS THIS EVENING INTO THE OVERNIGHT
HOURS. COVERAGE WILL LIKELY ONLY BE SCT SO HAVE ONLY INCLUDED A
VICINITY MENTION...FIRST AT KIPL THEN LATER AT KBLH. EVEN NEAR
TSRA...CIGS SHOULD REMAIN AOA 6K FT. TIMING OF SHRA/TSRA IS
MODERATE. OTHERWISE OUTSIDE OF THUNDERSTORMS...SFC WINDS WILL REMAIN
RATHER LIGHT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
UNSETTLED WEATHER EARLY NEXT WEEK WILL SLOWLY TRANSITION TO DRIER
CONDITIONS WITH SEVERAL DISTURBANCES PASSING THROUGH THE DISTRICT.
LIGHTER SHOWERS WILL FAVOR HIGHER TERRAIN LOCATIONS OF EASTERN
ARIZONA. AFTERNOON HUMIDITY VALUES IN A 25 TO 35 PERCENT RANGE EARLY
IN THE WEEK WILL ONLY DECREASE TO A 15 TO 25 PERCENT RANGE BY THE
MIDDLE AND END OF NEXT WEEK. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. A FEW STRONGER NORTHERLY WIND GUSTS DOWN THE LOWER
COLORADO RIVER VALLEY WILL BE POSSIBLE TUESDAY AND WEDNESDAY
AFTERNOON. OTHERWISE...WINDS WILL GENERALLY BE LIGHT AND NOT A FIRE
WEATHER IMPACT.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA
AVIATION...MO
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
220 PM MST THU OCT 15 2015
&&
.SYNOPSIS... LOW PRESSURE...MOVING SLOWLY INLAND FROM THE PACIFIC IS
EXPECTED TO MOVE SLOWLY ACROSS THE REGION OVER THE NEXT FEW DAYS.
SHOWER AND THUNDERSTORM CHANCES ARE EXPECTED TO INCREASE FROM WEST
TO EAST TONIGHT AND FRIDAY...WITH THE BEST CHANCES FOR MEASURABLE
RAINFALL BEING FROM LATE FRIDAY INTO EARLY SATURDAY. AFTER A BIT OF
A BREAK FROM LATE SATURDAY INTO EARLY SUNDAY...A SECOND LOW CENTER
IS THEN EXPECTED TO BRING ANOTHER CHANCE FOR SHOWERS LATE SUNDAY. A
SLOW DRYING TREND WILL COMMENCE EARLY NEXT WEEK AS HIGH PRESSURE
ATTEMPTS TO BUILD BACK INTO THE REGION.
&&
.DISCUSSION...
TONIGHT THROUGH SATURDAY... THE UPPER LOW...WHICH HAS BROUGHT
SHOWERS AND A FEW THUNDERSTORMS TO PARTS OF SE CA TODAY...IS NOW
BEGINNING TO MAKE LANDFALL ALONG THE SOUTHERN CA COAST NEAR POINT
CONCEPTION. THE LATEST MODEL SUITES ARE NOW SHOWING THAT THIS LOW
WILL MOVE VERY SLOWLY EASTWARD AND WEAKEN OVER THE NEXT 48
HOURS...NOT REACHING THE LOWER COLORADO RIVER VALLEY UNTIL LATE
MORNING ON SATURDAY. IT IS THEN FORECAST TO WEAKEN FURTHER...INTO AN
OPEN WAVE...AND ACCELERATE EASTWARD ACROSS AZ FROM SATURDAY
AFTERNOON INTO EARLY SUNDAY...AS THE NEXT UPSTREAM SHORTWAVE ACTS AS
A KICKER. AHEAD OF THIS LOW...DEEP SOUTHERLY FLOW CONTINUES TO PULL
MOISTURE NORTHWARD INTO THE REGION FROM THE SUBTROPICS. EMBEDDED
SHORTWAVES IN THIS SOUTHERLY FLOW IS PROVIDING THE TRIGGER FOR
SHOWER/THUNDERSTORM DEVELOPMENT. THE 1ST SHORTWAVE...THAT IS NOW
MOVING NORTHWARD INTO SOUTHERN NV...PRODUCED WIDESPREAD
SHOWER/THUNDERSTORM ACTIVITY ACROSS SE CA EARLY THIS MORNING. A
2ND...WEAKER SHORTWAVE IS NOW TRIGGERING SHOWERS ACROSS PARTS OF SE
AZ. THE LATEST HRRR HIGH-RES MODEL RUN IS SHOWING THAT ISOLATED-
SCATTERED SHOWERS DEVELOPING AND SPREADING NORTHWARD AND EASTWARD
ACROSS SW AND SOUTH-CENTRAL AZ THROUGH THE REMAINDER OF THIS
AFTERNOON AND EVENING. THUNDERSTORM ACTIVITY APPEARS IT WILL BE
ISOLATED AT BEST...AS THE AIRMASS REMAINS RATHER STABLE...WITH 0-6
KM BULK SHEAR REMAINING MAINLY AOB 30 KTS...AND CAPE MAINLY AOB 500
J/KG.
FRIDAY AFTERNOON AND FRIDAY NIGHT LOOKS LIKE IT BE A MORE ACTIVE
PERIOD...AT LEAST ACROSS SW AND SOUTH-CENTRAL AZ...AS THE UPPER
LOW/TROF APPROACHES FROM THE WEST. ALTHOUGH SHOWER ACTIVITY WILL
LIKELY BE FAIRLY WIDESPREAD ACROSS THE REGION...THUNDERSTORM
ACTIVITY WILL LIKELY BE LIMITED BY THE FACT THAT THE UPPER TROF WILL
BE WEAKENING AS IT APPROACHES...REDUCING THE AMOUNT OF WIND SHEAR
THROUGH THE COLUMN AND ALLOWING TEMPERATURES TO WARM A BIT ALOFT
NEAR THE UPPER LOW CENTER. HOWEVER...WITH CAPE VALUES RISING INTO
THE 500-1000 J/KG RANGE AND 0-6 KM BULK SHEAR APPROACHING 30
KTS...THE DEVELOPMENT OF A FEW SEVERE STORMS CANNOT BE RULED
OUT...ESPECIALLY IN/NEAR LOCATIONS THAT SEE BREAKS IN THE OVERCAST.
AS FAR AS TEMPERATURES ARE CONCERNED...A COOLING TREND IS STILL
EXPECTED ON FRIDAY AND SATURDAY DUE TO COOLER AIR ALOFT...INCREASED
CLOUDINESS...AND SHOWER ACTIVITY.
SUNDAY THROUGH WEDNESDAY...
FORECAST CONFIDENCE DURING THIS PERIOD CURRENTLY IS QUITE LOW...DUE
TO DIFFERENCES BETWEEN THE GLOBAL MODEL SUITES AND RUN-TO-RUN
DIFFERENCES WITHIN EACH MODEL SUITE CONCERNING THE DEVELOPMENT AND
MOVEMENT OF THE NEXT TWO UPPER LOW CENTERS THAT WILL BE AFFECTING
THE REGION DURING THIS PERIOD. THE 1ST UPPER LOW...WHICH IS EXPECTED
TO MOVE EASTWARD ACROSS THE GREAT BASIN ON SUNDAY AND MONDAY...IS
EXPECTED TO BRING MORE CHANCES FOR RAINFALL ACROSS CENTRAL AND
NORTHERN AZ...WITH THE BEST CHANCES LIKELY REMAINING NORTH OF OUR
CWA. THE SECOND UPPER LOW CENTER IS THEN FORECAST TO DROP
SOUTHEASTWARD ACROSS SE CA INTO NW MEXICO ON TUE AND WED. AT THIS
POINT...HAVE JUST LEFT OUR CURRENT MID AND LONG-RANGE POPS
ALONE...WHICH ARE NOW MAINLY IN THE SLIGHT CHANCE RANGE SUNDAY AND
MONDAY...THEN DWINDLE OFF AFTERWARDS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
UPPER LOW TO MOVE SLOWLY ACROSS THE AREA FROM THE WEST OVER THE NEXT
COUPLE OF DAYS LEADING TO INCREASING CHANCES FOR RAIN/STORMS. NOT
MUCH EXPECTED THRU THE AFTERNOON HOURS...JUST SOME MID/HI LEVEL
CLOUD DECKS. DO NOT EXPECT RAIN CHANCES OF CONSEQUENCE UNTIL THIS
EVENING. THUS HAVE ENTERED VCSH AFTER ABOUT 02Z FOR THE CENTRAL
DESERT TAF SITES. EXPECT CLOUD DECKS TO THICKEN/LOWER OVERNIGHT WITH
CIGS DOWN AROUND 10K BY FRIDAY MORNING. THERE MAY BE A STRAY
THUNDERSTORM MIXED IN TONIGHT BUT CHANCES TOO LOW TO MENTION IN THE
TAFS. WINDS AGAIN WILL BE ON THE LIGHT SIDE WITH TYPICAL DIURNAL
TENDENCIES.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
UPPER LOW MOVING SLOWLY EASTWARD ACROSS THE AREA THROUGH FRIDAY WILL
BRING A GOOD CHANCE OF SHOWERS WITH EMBEDDED STORMS...ESPECIALLY
THIS MORNING. DO NOT EXPECT OVERLY LOW CIGS...MOST SHOULD RANGE FROM
8K TO 12K FEET TODAY...UNLESS ESPECIALLY HEAVY/LONG LASTING SHOWERS
DEVELOP. MENTIONED -SHRA IN THE TAFS THROUGH 16Z WITH VCTS ALTHOUGH
SHOWERS COULD BE PREDOMINANT INTO THE AFTERNOON HOURS. STORMS SHOULD
BE ON THE ISOLATED SIDE THUS THE VICINITY WORDING. FOLLOWING THIS
EVENING MOST OF THE PRECIP SHOULD BE FOCUSED OVER AZ...THERE MAY BE
A LINGERING SHOWER BUT CHANCES TOO LOW TO CONTINUE MENTIONING IN THE
TAFS. WINDS SHOULD BE ON THE LIGHT SIDE FAVORING WEST TO NORTH.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
UNSETTLED WEATHER WILL CONTINUE THROUGH MOST OF THE WEEKEND...WITH
ANY WETTING RAINS FAVORING HIGHER TERRAIN AREAS OF CENTRAL ARIZONA
SATURDAY. WHILE DRIER WEATHER WILL GRADUALLY SPREAD INTO THE REGION
NEXT WEEK...A FEW LIGHTER SHOWERS MAY STILL BE POSSIBLE EARLY IN THE
WEEK. AFTERNOON HUMIDITY VALUES WILL REMAIN ELEVATED IN A 25 TO 35
PERCENT RANGE DURING THE WEEKEND...ONLY DRYING TO A 15 TO 25 PERCENT
RANGE BY THE MIDDLE OF NEXT WEEK. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. A FEW STRONGER EASTERLY RIDGE TOP AND GAP WIND GUSTS WILL
POSSIBLE SATURDAY OVER CENTRAL ARIZONA...AND NORTHERLY WIND GUSTS
DOWN THE LOWER COLORADO RIVER VALLEY TUESDAY AND WEDNESDAY.
OTHERWISE...WINDS WILL GENERALLY BE LIGHT AND NOT A FIRE WEATHER
IMPACT. EXPECT HIGH TEMPERATURES NEAR OR SLIGHTLY ABOVE SEASONAL
NORMALS EACH DAY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA
AVIATION...CB
FIRE WEATHER...MO/CB
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1102 PM PDT WED OCT 14 2015
.SYNOPSIS...AN UPPER LEVEL LOW PRESSURE AREA MOVING INLAND OVER
SOUTH-CENTRAL CALIFORNIA WILL CONTINUE TO GENERATE SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE SOUTHERN PORTION OF
OUR FORECAST AREA THROUGH THURSDAY. IN ADDITION...THE EASTERN
PORTION OF THE SAN FRANCISCO BAY AREA MAY SEE ISOLATED SHOWERS AND
THUNDERSTORMS TONIGHT. DRY CONDITIONS WILL RETURN BY FRIDAY.
GRADUAL COOLING IS ALSO FORECAST THROUGH FRIDAY. ANOTHER SYSTEM
APPROACHING FROM THE WEST WILL BRING A SLIGHT CHANCE OF
PRECIPITATION TO THE NORTH BAY ON SATURDAY.
&&
.DISCUSSION...AS OF 9:25 PM PDT WEDNESDAY...AN UPPER LOW IS
CENTERED ABOUT 150 MILES SOUTHWEST OF POINT CONCEPTION THIS
EVENING AND IS MOVING SLOWLY TO THE NORTHEAST. SCATTERED SHOWERS
AND THUNDERSTORMS DEVELOPED OVER MONTEREY AND SAN BENITO COUNTIES
THIS AFTERNOON AND HAVE CONTINUED THIS EVENING. A FEW STRONG
STORMS DEVELOPED OVER SOUTHERN AND WESTERN MONTEREY COUNTY WITH
NUMEROUS LIGHTNING STRIKES. BRIEF HEAVY DOWNPOURS HAVE BEEN
REPORTED WITH THE THUNDERSTORMS...BUT THESE STORMS HAVE BEEN
MOVING QUICKLY TO THE WEST-NORTHWEST WHICH HAS LIMITED RAINFALL
TOTALS TO ABOUT A TENTH OF AN INCH OR LESS. THE GREATEST RAINFALL
REPORT THUS FAR HAS BEEN IN CARMEL-BY-THE-SEA WHERE 0.15" HAS
FALLEN.
BY MID-EVENING SHOWER AND THUNDERSTORM ACTIVITY HAD DECREASED
ACROSS MONTEREY AND SAN BENITO COUNTIES...BUT SATELLITE AND RADAR
SHOW RENEWED CONVECTIVE DEVELOPMENT JUST TO THE SOUTHEAST OF OUR
CWA...MOVING TO THE NORTHWEST. AND...THE 00Z NAM SHOWS CONVECTIVE
PRECIP CONTINUING OVERNIGHT ACROSS THE SOUTHERN PORTION OF OUR
CWA. IN ADDITION...THE HRRR MODEL FORECASTS SCATTERED PRECIP
DEVELOPING ACROSS PORTIONS OF THE EAST AND SOUTH BAY
OVERNIGHT. THIS HRRR FORECAST IS BACKED-UP BY RECENT RADAR DATA
SHOWING ISOLATED SHOWERS DEVELOPING OVER THE SAN JOAQUIN
VALLEY...MOVING TO THE WEST-NORTHWEST AND APPROACHING THE EAST
BAY. A FORECAST UPDATE WAS JUST COMPLETED TO EXPAND SLIGHT
SHOWER/THUNDERSTORM CHANCES ACROSS MORE OF THE EASTERN AND
SOUTHERN SF BAY AREA OVERNIGHT.
SCATTERED CONVECTIVE PRECIPITATION IS EXPECTED TO PERSIST ACROSS
MONTEREY AND SAN BENITO COUNTIES THROUGH THURSDAY AND INTO
THURSDAY EVENING AS THE UPPER LOW CONTINUES ITS NORTHEASTWARD
DRIFT TOWARDS POINT CONCEPTION. SOME MODEL DATA SUGGESTS SOME OF
THIS CONVECTIVE PRECIPITATION MAY REACH INTO THE SOUTHERN AND
EASTERN PORTIONS OF THE SF BAY AREA ON THURSDAY. THERE MAY BE A
NEED TO EXPAND PRECIPITATION CHANCES FARTHER NORTH AND WEST FOR
THURSDAY DEPENDING ON WHAT THE CONSENSUS OF 00Z MODEL DATA LOOKS
LIKE.
TEMPERATURES REMAINED WELL ABOVE NORMAL TODAY...ESPECIALLY ACROSS
THE SF BAY AREA WHERE THERE WAS PLENTY OF SUN. TEMPERATURES ARE
EXPECTED TO GRADUALLY COOL THROUGH FRIDAY...BUT STILL REMAIN
WARMER THAN NORMAL...ESPECIALLY ACROSS THE NORTHERN PORTION OF OUR
FORECAST AREA.
PATCHY DENSE FOG FORMED NEAR THE COAST LATE THIS AFTERNOON...BUT
VISIBILITIES HAVE SINCE IMPROVED FROM MONTEREY BAY SOUTHWARD AS
CONVECTION HAS PRODUCED MIXING IN THE BOUNDARY LAYER.
HOWEVER...PATCHY DENSE COASTAL FOG CONTINUES ALONG THE SF BAY AREA
COAST. EXPECT PATCHY FOG TO CONTINUE OVERNIGHT AND INTO THURSDAY
MORNING...ESPECIALLY IN NORTHERN COASTAL AREAS MORE REMOVED FROM
THE CONVECTION.
FROM PREVIOUS DISCUSSION...THE LATEST FORECAST MODELS SHOW THE
MID/UPPER LEVEL LOW WILL REMAIN OVER SOUTHERN/CENTRAL CALIFORNIA
THROUGH FRIDAY...WITH MOST OF THE MOISTURE ON THE EAST SIDE OF THE
SYSTEM. THUS...EXPECTING GENERALLY DRY WEATHER CONDITIONS TO
RETURN ON FRIDAY. WITH COOLER TEMPERATURES ALOFT...SURFACE
CONDITIONS WILL ALSO BE ON A COOLING TREND THROUGH LATE WEEK.
BY THE WEEKEND...THE MODELS CONTINUE TO PUSH A BROAD MID/UPPER LEVEL
TROUGH INTO THE PACIFIC NORTHWEST. THIS WILL DRIVE A FRONTAL
BOUNDARY INTO THE SAN FRANCISCO/MONTEREY BAY REGION ON SATURDAY.
HOWEVER...THE LATEST MODEL OUTPUT CONTINUE TO SHOW LIMITED MOISTURE
ASSOCIATED WITH THE FRONTAL PASSAGE. AS A RESULT...HAVE KEPT ONLY A
SLIGHT CHANCE OF SHOWERS OVER THE NORTHERN PART OF THE REGION ON
SATURDAY. WORTH NOTING...THE CANADIAN MODEL CONTINUES TO BE THE MOST
AGGRESSIVE WITH A CLOSED LOW DEVELOPING ON THE SOUTHERN END OF THE
TROUGH...PUSHING INLAND OVER THE SAN FRANCISCO BAY AREA LATE
SATURDAY. THIS SOLUTION BRINGS LIGHT...BUT MORE WIDESPREAD
PRECIPITATION TO THE ENTIRE FORECAST AREA. AT THIS TIME...WILL TREND
TOWARD THE GFS AND ECMWF MODELS...SHOWING DRY CONDITIONS OVER THE
CENTRAL COAST. AS THIS TROUGH SHIFTS INLAND ON SUNDAY...DRY
CONDITIONS RETURN AND TEMPERATURES WARM EARLY NEXT WEEK AS HIGH
PRESSURE BUILDS OVER THE EASTERN PACIFIC.
&&
.AVIATION...AS OF 11:00 PM PDT WEDNESDAY...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS WILL CONTINUE TONIGHT AND THURSDAY. UPPER
LOW OFF CA COAST WILL DRIFT EASTWARD THROUGH THE PERIOD. MARINE
INVERSIONS HAVE DEEPENED TO ABOUT 1000 FEET SINCE THE AFTERNOON
THUS STRATUS AND/OR FOG LIKELY TO MOVE LOCALLY INLAND OVERNIGHT.
LOCAL IFR TONIGHT. KHAF REPORTING 1/2SM VSBY IN FOG AND 200 FOOT
CEILING.
VICINITY OF KSFO...VFR. LIGHT WINDS TONIGHT AND THURSDAY MORNING.
W-SW WIND 10 KNOTS THURSDAY AFTERNOON.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...AREA METARS INDICATING VFR. MORE
SHOWERS SEEN MOVING NW OVER MONTREY AND SAN BENITO COUNTIES WILL
HELP KEEP SUFFICIENT MIXING GOING A WHILE LONGER TONIGHT. HOWEVER
PATCHY FOG AND IFR POSSIBLY RETURNING AGAIN THURSDAY MORNING AS
THE BOUNDARY LAYER REMAINS NEAR SATURATION.
&&
.MARINE...AS OF 9:37 PM PDT WEDNESDAY...LOW PRESSURE AREA SW OF
THE CENTRAL COAST WILL DRIFT SLOWLY EAST OVERNIGHT INTO THURSDAY.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TO MOVE
NORTHWARD OVER THE COASTAL WATERS. LIGHT SOUTHERLY WINDS WILL
SWITCH TO NORTHWEST AND INCREASE FRIDAY THROUGH SUNDAY AS THE LOW
MOVES INLAND AND HIGH PRESSURE BUILDS OFF THE CALIFORNIA COAST.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE.
$$
PUBLIC FORECAST: DYKEMA/RGASS
AVIATION/MARINE: CANEPA
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
928 PM PDT WED OCT 14 2015
.SYNOPSIS...AN UPPER LEVEL LOW PRESSURE AREA MOVING INLAND OVER
SOUTH-CENTRAL CALIFORNIA WILL CONTINUE TO GENERATE SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE SOUTHERN PORTION OF
OUR FORECAST AREA THROUGH THURSDAY. IN ADDITION...THE EASTERN
PORTION OF THE SAN FRANCISCO BAY AREA MAY SEE ISOLATED SHOWERS AND
THUNDERSTORMS TONIGHT. DRY CONDITIONS WILL RETURN BY FRIDAY.
GRADUAL COOLING IS ALSO FORECAST THROUGH FRIDAY. ANOTHER SYSTEM
APPROACHING FROM THE WEST WILL BRING A SLIGHT CHANCE OF
PRECIPITATION TO THE NORTH BAY ON SATURDAY.
&&
.DISCUSSION...AS OF 9:25 PM PDT WEDNESDAY...AN UPPER LOW IS
CENTERED ABOUT 150 MILES SOUTHWEST OF POINT CONCEPTION THIS
EVENING AND IS MOVING SLOWLY TO THE NORTHEAST. SCATTERED SHOWERS
AND THUNDERSTORMS DEVELOPED OVER MONTEREY AND SAN BENITO COUNTIES
THIS AFTERNOON AND HAVE CONTINUED THIS EVENING. A FEW STRONG
STORMS DEVELOPED OVER SOUTHERN AND WESTERN MONTEREY COUNTY WITH
NUMEROUS LIGHTNING STRIKES. BRIEF HEAVY DOWNPOURS HAVE BEEN
REPORTED WITH THE THUNDERSTORMS...BUT THESE STORMS HAVE BEEN
MOVING QUICKLY TO THE WEST-NORTHWEST WHICH HAS LIMITED RAINFALL
TOTALS TO ABOUT A TENTH OF AN INCH OR LESS. THE GREATEST RAINFALL
REPORT THUS FAR HAS BEEN IN CARMEL-BY-THE-SEA WHERE 0.15" HAS
FALLEN.
BY MID-EVENING SHOWER AND THUNDERSTORM ACTIVITY HAD DECREASED
ACROSS MONTEREY AND SAN BENITO COUNTIES...BUT SATELLITE AND RADAR
SHOW RENEWED CONVECTIVE DEVELOPMENT JUST TO THE SOUTHEAST OF OUR
CWA...MOVING TO THE NORTHWEST. AND...THE 00Z NAM SHOWS CONVECTIVE
PRECIP CONTINUING OVERNIGHT ACROSS THE SOUTHERN PORTION OF OUR
CWA. IN ADDITION...THE HRRR MODEL FORECASTS SCATTERED PRECIP
DEVELOPING ACROSS PORTIONS OF THE EAST AND SOUTH BAY
OVERNIGHT. THIS HRRR FORECAST IS BACKED-UP BY RECENT RADAR DATA
SHOWING ISOLATED SHOWERS DEVELOPING OVER THE SAN JOAQUIN
VALLEY...MOVING TO THE WEST-NORTHWEST AND APPROACHING THE EAST
BAY. A FORECAST UPDATE WAS JUST COMPLETED TO EXPAND SLIGHT
SHOWER/THUNDERSTORM CHANCES ACROSS MORE OF THE EASTERN AND
SOUTHERN SF BAY AREA OVERNIGHT.
SCATTERED CONVECTIVE PRECIPITATION IS EXPECTED TO PERSIST ACROSS
MONTEREY AND SAN BENITO COUNTIES THROUGH THURSDAY AND INTO
THURSDAY EVENING AS THE UPPER LOW CONTINUES ITS NORTHEASTWARD
DRIFT TOWARDS POINT CONCEPTION. SOME MODEL DATA SUGGESTS SOME OF
THIS CONVECTIVE PRECIPITATION MAY REACH INTO THE SOUTHERN AND
EASTERN PORTIONS OF THE SF BAY AREA ON THURSDAY. THERE MAY BE A
NEED TO EXPAND PRECIPITATION CHANCES FARTHER NORTH AND WEST FOR
THURSDAY DEPENDING ON WHAT THE CONSENSUS OF 00Z MODEL DATA LOOKS
LIKE.
TEMPERATURES REMAINED WELL ABOVE NORMAL TODAY...ESPECIALLY ACROSS
THE SF BAY AREA WHERE THERE WAS PLENTY OF SUN. TEMPERATURES ARE
EXPECTED TO GRADUALLY COOL THROUGH FRIDAY...BUT STILL REMAIN
WARMER THAN NORMAL...ESPECIALLY ACROSS THE NORTHERN PORTION OF OUR
FORECAST AREA.
PATCHY DENSE FOG FORMED NEAR THE COAST LATE THIS AFTERNOON...BUT
VISIBILITIES HAVE SINCE IMPROVED FROM MONTEREY BAY SOUTHWARD AS
CONVECTION HAS PRODUCED MIXING IN THE BOUNDARY LAYER.
HOWEVER...PATCHY DENSE COASTAL FOG CONTINUES ALONG THE SF BAY AREA
COAST. EXPECT PATCHY FOG TO CONTINUE OVERNIGHT AND INTO THURSDAY
MORNING...ESPECIALLY IN NORTHERN COASTAL AREAS MORE REMOVED FROM
THE CONVECTION.
FROM PREVIOUS DISCUSSION...THE LATEST FORECAST MODELS SHOW THE
MID/UPPER LEVEL LOW WILL REMAIN OVER SOUTHERN/CENTRAL CALIFORNIA
THROUGH FRIDAY...WITH MOST OF THE MOISTURE ON THE EAST SIDE OF THE
SYSTEM. THUS...EXPECTING GENERALLY DRY WEATHER CONDITIONS TO
RETURN ON FRIDAY. WITH COOLER TEMPERATURES ALOFT...SURFACE
CONDITIONS WILL ALSO BE ON A COOLING TREND THROUGH LATE WEEK.
BY THE WEEKEND...THE MODELS CONTINUE TO PUSH A BROAD MID/UPPER LEVEL
TROUGH INTO THE PACIFIC NORTHWEST. THIS WILL DRIVE A FRONTAL
BOUNDARY INTO THE SAN FRANCISCO/MONTEREY BAY REGION ON SATURDAY.
HOWEVER...THE LATEST MODEL OUTPUT CONTINUE TO SHOW LIMITED MOISTURE
ASSOCIATED WITH THE FRONTAL PASSAGE. AS A RESULT...HAVE KEPT ONLY A
SLIGHT CHANCE OF SHOWERS OVER THE NORTHERN PART OF THE REGION ON
SATURDAY. WORTH NOTING...THE CANADIAN MODEL CONTINUES TO BE THE MOST
AGGRESSIVE WITH A CLOSED LOW DEVELOPING ON THE SOUTHERN END OF THE
TROUGH...PUSHING INLAND OVER THE SAN FRANCISCO BAY AREA LATE
SATURDAY. THIS SOLUTION BRINGS LIGHT...BUT MORE WIDESPREAD
PRECIPITATION TO THE ENTIRE FORECAST AREA. AT THIS TIME...WILL TREND
TOWARD THE GFS AND ECMWF MODELS...SHOWING DRY CONDITIONS OVER THE
CENTRAL COAST. AS THIS TROUGH SHIFTS INLAND ON SUNDAY...DRY
CONDITIONS RETURN AND TEMPERATURES WARM EARLY NEXT WEEK AS HIGH
PRESSURE BUILDS OVER THE EASTERN PACIFIC.
&&
.AVIATION...AS OF 6:17 PM PDT WEDNESDAY...LOW CENTER LOCATED
APPROX 300 MILES SW OF SANTA MARIA. SHOWER/T-STORM ACTIVITY MOSTLY
CONFINED TO MONTEREY COUNTY AT THE MOMENT BUT INSTABILITY LIFTING
NORTH DURING THE PERIOD. AREAS OF FOG LOCALLY DENSE FOG ALONG THE
COAST. MARINE INVERSIONS MOSTLY COMPRESSED TO A FEW HUNDRED FEET
DEEP BUT GRADUAL SURFACE TO LOW LEVEL COOLING SAN FRANCISCO
PENINSULA TO NORTH CENTRAL COAST OVERNIGHT ALLOWING FOR ADDITIONAL
LOCAL FOG INLAND INTRUSIONS. OTHERWISE INLAND CONDITIONS REMAINING
VFR.
VICINITY OF KSFO...VFR. W-NW WINDS NEAR 10 KNOTS BECOMING LIGHT/VARIABLE
THIS EVENING. WILL AMEND TAF AS NEEDED BASED ON POTENTIAL SHWR/ISOLATED
T-STORM DEVELOPMENT THIS EVENING AND/OR OVERNIGHT.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...RAPID WEATHER CHANGES FROM VICINITY
T-STORM BACK AT 2-3 PM... NOW 1/4 MILE IN FOG VV001 AT KMRY. STILL
CLEAR AOB 12K FEET PER KSNS AND KWVI ASOS. RADAR SHOWS SHWRS/T-STORMS
OVER CENTRAL AND SOUTHERN MONTEREY COUNTY LIFTING NW AT ABOUT
20-25 KNOTS...SOME VERTICAL MIXING LIKELY RETURNING TO WITH
SHOWERS IN VICINITY OF MONTEREY PENINSULA APPROX 03Z...COULD
EASILY GO RIGHT BACK TO VFR THIS EVENING. MORE FOG POSSIBLE LATE
AT NIGHT AS BOUNDARY LAYER SUPPORTIVE OF NEAR SATURATION OF AIR
MASS.
&&
.MARINE...AS OF 09:25 AM PDT WEDNESDAY...AN UPPER LEVEL LOW OFF
THE SOUTHERN CALIFORNIA COAST WILL BRING A SLIGHT CHANCE OF
THUNDERSTORMS TO THE SOUTHERN WATERS TODAY AND TONIGHT. LIGHT
SOUTHERLY WINDS WILL SWITCH TO NORTHWEST AND INCREASE FRIDAY
THROUGH SUNDAY AS THE LOW MOVES INLAND AND HIGH PRESSURE BUILDS
OFF THE CALIFORNIA COAST.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE.
$$
PUBLIC FORECAST: DYKEMA/RGASS
AVIATION: CANEPA
MARINE: W PI
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS ALBANY NY
354 PM EDT THU OCT 15 2015
.SYNOPSIS...
CLOUDS WILL INCREASE THIS EVENING AS A COLD FRONT
APPROACHES FROM THE GREAT LAKES REGION WHICH WILL CROSS THE REGION
LATE TONIGHT INTO TOMORROW WITH SOME RAIN SHOWERS. YET ANOTHER COLD
FRONT WILL PASS THROUGH THE REGION ON SATURDAY...AND THIS SYSTEM
WILL USHER IN MUCH COLDER AIR INTO THE REGION FOR THE WEEKEND...WITH
A FEW LINGERING RAIN AND MOUNTAIN SNOW SHOWERS POSSIBLE.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 353 PM EDT...A STORM SYSTEM OVER THE GREAT LAKES IS QUICKLY
MOVING EASTWARD TOWARDS THE REGION. ALTHOUGH SKIES ARE CURRENTLY
MOSTLY SUNNY...CLOUDS ARE QUICKLY APPROACHING WESTERN NY AND
ONTARIO. 12Z NAM12 AND 18Z 3KM HRRR GUIDANCE SUGGEST RAINFALL WILL
START ACROSS WESTERN AREAS BY 11 PM...AND SPREAD EASTWARD
OVERNIGHT. RAINFALL LOOKS FAIRLY LIGHT AND WILL ONLY LAST A FEW
HOURS AT ANY ONE PARTICULAR LOCATION. BEST CHANCE OF SEEING A
SHOWER WILL BE ACROSS NORTHERN AREAS...CLOSER TO THE BEST FORCING.
MOST AREAS WILL ONLY SEE A FEW HUNDREDTHS OF AN INCH...BUT PARTS
OF THE WESTERN ADIRONDACKS COULD SEE AS MUCH AS A THIRD OF AN
INCH.
WITH THE CLOUDS/PRECIP OVERNIGHT...TEMPS WILL BE A LITTLE WARMER
THAN LAST NIGHT. LOWS WILL GENERALLY BE IN THE MID 40S...ALTHOUGH
HIGH TERRAIN AREAS WILL FALL INTO THE UPPER 30S TO LOW 40S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
A COLD FRONT WILL BE EXITING THE REGION ON FRIDAY MORNING ACROSS
WESTERN NEW ENGLAND. THE BEST CHANCE FOR SEEING LINGERING RAIN
SHOWERS ON FRIDAY WILL BE ACROSS HIGH TERRAIN AND EASTERN AREAS ON
FRIDAY MORNING...WITH A PARTLY SUNNY SKY EXPECTED BY AFTERNOON FOR
MOST VALLEY AREAS. SOME CLOUDS MAY BE STILL BE AROUND FOR THE
HIGHER TERRAIN LOCATIONS. WEST WINDS WILL INCREASE BEHIND THE
BOUNDARY AND BE GUSTY AT TIMES...WITH SOME GUSTS OVER 25 MPH
POSSIBLE. DESPITE BEING BEHIND THE SFC BOUNDARY...GOOD MIXING WILL
STILL KEEP HIGH TEMPS SEASONABLE...WITH HIGHS IN THE MID 50S TO
LOW 60S FOR VALLEY AREAS. HIGH TERRAIN AREAS WILL BE A LITTLE
COOLER...WITH SOME 40S TO LOW 50S OVER THE ADIRONDACKS AND SRN
GREENS.
A REINFORCING SHOT OF COLD AIR LOOKS TO ARRIVE FOR FRI NIGHT INTO
SATURDAY...AS ANOTHER COLD FRONT CROSSES THE REGION. THIS WILL
USHER IN MUCH COLDER AIR ALOFT INTO THE REGION FOR THE
WEEKEND...WITH 850 HPA TEMPS DROPPING TO -10 DEGREES C BY SAT
NIGHT....AS A DEEP AND SHARP UPPER LEVEL TROUGH MOVES OVER THE
NORTHEAST.
SOME ADDITIONAL SHOWERS ARE POSSIBLE FOR FRI NIGHT INTO
SATURDAY...ESP ACROSS THE HIGH TERRAIN AREAS...AS THE SECONDARY
COLD FRONT AND CYCLONIC FLOW ALOFT ALLOWS FOR SOME MORE SHOWERS.
MOISTURE WILL BE MORE LIMITED WITH THIS BOUNDARY THAN THE PREVIOUS
ONE...SO PRECIP WILL BE FAIRLY SPOTTY. WITH THE COLDER AIR MOVING
IN ALOFT...SOME OF THESE SHOWERS COULD FALL AS SNOW SHOWERS FOR
THE HIGH TERRAIN AREAS...ESP FOR THE LATE NIGHT AND EARLY MORNING
HOURS WHEN THE BOUNDARY LAYER COOLS OFF. IT SHOULD REMAIN WARM
ENOUGH IN MOST VALLEY AREAS FOR PRECIP TO REMAIN AS RAIN
SHOWERS...BUT CAN/T RULE OUT SOME GRAUPEL WITHIN ANY SHOWERS THAT
HAVE A BRIEF HEAVIER INTENSITY. QPF WILL ONLY BE A FEW HUNDREDTHS
OF AN INCH...AND COVERAGE WILL BE FAIRLY SPOTTY...WITH THE BEST
CHANCE FOR NORTHERN AND HIGH TERRAIN AREAS. SKY COVER LOOKS MOSTLY
CLOUDY FOR MUCH OF THE REGION...ALTHOUGH FAR SOUTHEASTERN AREAS
WILL HAVE THE BEST CHANCE OF SEEING SOME BREAKS DUE TO
DOWNSLOPING. MIN TEMPS ON FRI NIGHT WILL GENERALLY BE IN THE
UPPER 30S FOR VALLEY AREAS...WITH LOW TO MID 30S FOR HIGH TERRAIN
LOCATIONS. HIGHS ON SATURDAY WILL BE IN THE MID 40S TO MID 50S FOR
MOST AREAS...WITH 30S OVER THE ADIRONDACKS. IT WILL CONTINUE TO BE
BREEZY ON SATURDAY...MAKING IT FEEL EVEN COLDER.
TEMPS WILL BE EVEN COLDER FOR SAT NIGHT...WITH THE ENTIRE REGION
FALLING BELOW FREEZING. THIS WON/T BE A TYPICAL RADIATIVE COOLING
NIGHT...AS A CHILLY NW BREEZE WILL CONTINUE WITH SOME PASSING
CLOUDS STILL AROUND /ALTHOUGH NOT AS MANY CLOUDS AS DURING THE
DAY SATURDAY/. A FREEZE WARNING WILL LIKELY BE NEEDED IN AREAS
WHERE THE GROWING SEASON IS STILL ONGOING /HUDSON VALLEY AND
SOUTHERN LITCHFIELD COUNTY CT/ AND WILL CONTINUE TO HIGHLIGHT THIS
THREAT IN THE HWO STATEMENT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
RESIDUAL RAIN/SNOW SHOWERS ARE POSSIBLE ACROSS HIGH TERRAIN NORTH
AND WEST OF THE IMMEDIATE CAPITAL REGION AS A UPPER LEVEL TROUGH
EXITS THE REGION TOWARD THE NEW ENGLAND COASTLINE DURING THE DAY ON
SUNDAY. OTHERWISE IMPROVING CONDITIONS ARE EXPECTED AS WE GO INTO
EARLY NEXT WEEK AS A LARGE SURFACE HIGH PRESSURE WILL MOVE INTO THE
REGION AS WE GO INTO MONDAY MORNING. AS THE CENTER OF THE SURFACE
LOW PRESSURE MOVES CLOSER INTO THE REGION MONDAY EVENING...WINDS
WILL SHIFT TO THE SOUTHWEST ADVECTING WARMER AIR FROM THE SOUTH INTO
THE REGION WHICH WILL BE IN PLACE THROUGHOUT THE REMAINDER OF THE
LONG TERM PERIOD AS H850 AND H925 TEMPS WILL MODIFY AND BY WEDNESDAY
RANGE FROM 4C TO 8C AND 6C TO 9C RESPECTIVELY. HIGH TEMPS ON SUNDAY
AND MONDAY WILL BE BELOW AVERAGE.
LATEST 15/12Z MODEL AND PROBAILISTIC GUIDANCE SHOW A STALLED FRONT
FROM THE OHIO VALLEY NORTHEAST INTO SOUTHERN ONTARIO AS WE GO INTO
THE DAY ON TUESDAY. THE 12Z MODEL RUNS OUTPUT DO DIFFER IN THE
EQUATORWARD EXTENT OF THE PRECIPITATION FROM TUESDAY INTO WEDNESDAY.
SLIGHT CHANCE TO CHANCE POPS ARE IN THE FORECAST FOR THE ENTIRE
REGION WITH THE BEST CHANCES ACROSS FAR NORTHERN AREAS. WITH NO
SUBSTANTIAL UPPER LEVEL DYNAMICS ALONG THE FRONT AND WITH THE FRONT
BEING STALLED IN CANADA TOO FAR REMOVED FROM OUR
REGION...PRECIPITATION CHANCES LOOK LOW OVERALL INTO THE MIDDLE OF
NEXT WEEK. FORECAST WILL BE MODIFIED AS WE GET CLOSER TO THE EVENT.
HIGH TEMPS TUESDAY AND WEDNESDAY WILL BE AT OR WELL ABOVE AVERAGE
ESPECIALLY AS WE GO INTO WEDNESDAY.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
A COLD FRONT WILL PASS THROUGH THE TAF SITES FROM WEST TO EAST LATE
TONIGHT...PRECEDED AND ACCOMPANIED BY SOME RAIN SHOWERS. COOLER
AIR...ALONG WITH CLOUDS AND ISOLATED SHOWERS/SPRINKLES WILL FOLLOW
IN THE WAKE OF THE FRONT THROUGH FRI MORNING.
VFR CONDITIONS WILL PERSIST THROUGH SUNSET. THEREAFTER...AS THE COLD
FRONT APPROACHES FROM THE W...A BAND OF RAIN SHOWERS SHOULD
PRECEDE/ACCOMPANY THE FRONT...AND SHOULD MOVE ACROSS THE KGFL/KALB
AND KPSF TAF SITES BETWEEN ROUGHLY 05Z-09Z/FRI. A BRIEF PERIOD OF
MVFR VSBYS COULD OCCUR...ALTHOUGH SINCE IT WILL BE QUITE
BRIEF...HAVE ONLY INDICATED VFR CONDITIONS AT THIS TIME. SHOWERS
SHOULD BE MORE ISOLATED AT KPOU...WHERE ONLY VCSH IS INDICATED.
IN THE WAKE OF THE FRONT...ISOLATED SHOWERS OR SPRINKLES MAY PERSIST
THROUGH MIDDAY FRIDAY...ESP AT KALB AND KPSF...WHERE VCSH IS
INDICATED. IN ADDITION...AREAS OF CLOUDS WILL OCCUR AT THESE TAF
SITES...WHICH COULD APPROACH MVFR CIGS AT TIMES.
WINDS WILL BACK INTO THE SOUTHWEST THIS AFTERNOON AT 5-10 KT. WINDS
MAY BRIEFLY BECOME LIGHT/VARIABLE AROUND AND AFTER SUNSET...EXCEPT
SHOULD REMAIN FROM THE SOUTH AND INCREASE TO 8-12 KT AT KALB WITH
SOME GUSTS UP TO 20 KT POSSIBLE. WINDS WILL BECOME SOUTHWEST TO WEST
IN THE WAKE OF THE FRONT TOWARD DAYBREAK FRIDAY AT 8-12 KT...THEN
BECOME MAINLY WEST BY MID MORNING AT 10-15 KT...WITH SOME GUSTS OF
25 KT OR GREATER POSSIBLE...ESP AT KALB AND KPSF.
WINDS MAY ALSO BECOME BRIEFLY GUSTY IN THE VICINITY OF ANY RAIN
SHOWERS TONIGHT.
OUTLOOK...
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
A COLD FRONT WILL CROSS THE REGION TONIGHT INTO TOMORROW MORNING
WITH SOME RAIN SHOWERS. RH VALUES WILL FALL TO 45 TO 60 PERCENT
OVER MUCH OF THE AREA TOMORROW AFTERNOON WITH A MIX OF SUN AND
CLOUDS. RH VALUES MAY STAY HIGHER IN THE ADIRONDACKS...WHERE MORE
CLOUDS ARE EXPECTED. WINDS WILL BECOME WEST AT 10 TO 20 MPH.
SOME ADDITIONAL RAIN AND MOUNTAIN SNOW SHOWERS ARE POSSIBLE OVER
THE WEEKEND. RH VALUES WILL FALL TO 35 TO 60 PERCENT ON
SATURDAY...AND 35 TO 50 PERCENT ON SUNDAY. THE LOWEST VALUES WILL
BE OVER THE MID HUDSON VALLEY AND NW CT...WITH THE HIGHEST VALUES
OVER THE WESTERN ADIRONDACKS. WEST TO NORTHWEST WINDS WILL BE 10
TO 25 MPH ON SATURDAY...AND NW AT 5 TO 15 MPH ON SUNDAY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THROUGH EARLY NEXT WEEK.
A COLD FRONT WILL CROSS THE REGION LATE TONIGHT INTO TOMORROW
MORNING WITH SOME RAIN SHOWERS...MAINLY FOR NORTHERN AREAS.
ANOTHER COLD FRONT WILL CROSS THROUGH THE AREA ON SATURDAY...WITH
SOME ADDITIONAL PRECIPITATION POSSIBLE.
ANY PRECIP THROUGH THE WEEKEND WILL BE RATHER LIGHT AND MAINLY
SCATTERED IN NATURE...AND COULD EVEN FALL AS SNOW SHOWERS OVER THE
HIGHEST TERRAIN AT TIMES. BASIN AVERAGE QPF WILL RANGE FROM JUST A
FEW HUNDREDTHS TO AS MUCH AS FOUR TENTHS OF AN INCH OVER THE
WESTERN ADIRONDACKS.
AS A RESULT...STREAM...CREEK...BROOK...LAKE...RESERVOIR...AND
RIVER LEVELS WILL GENERALLY REMAIN STEADY OR SLOWLY FALL THROUGH
EARLY NEXT WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...LFM
AVIATION...KL
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
858 AM EDT THU OCT 15 2015
.UPDATE...
FORECAST REMAINS LARGELY ON TRACK THIS MORNING. SURFACE BOUNDARY
HAS PUSHED THROUGH THE AREA AND IS LOCATED ACROSS THE FAR SOUTHERN
TIP OF THE PENINSULA THIS MORNING. LIGHT NORTH FLOW IS ALREADY
SHOWING SIGNS OF VEERING TO THE NORTHEAST AS BROAD HIGH PRESSURE
BUILDS INTO THE SOUTHEAST US. TOTAL ATMOSPHERIC MOISTURE (PWAT)
REMAINS LOW...BETWEEN 0.9 TO 1.2 INCHES...WITH NEARLY ALL OF THE MOISTURE
TRAPPED BENEATH A STRONG INVERSION AT 850MB. DESPITE SLIGHT
AIRMASS MODIFICATION AS WINDS VEER ONSHORE TODAY...AND THE
INSISTENCE OF THE LOCAL WRF AND HRRR ON DEVELOPING SHOWERS ACROSS
SOUTHERN AREAS...HAVE KEPT THE FORECAST RAIN-FREE FOR TODAY.
PLENTY OF SUNSHINE AND THE SLIGHTLY DRIER AIR SHOULD ALLOW TEMPS
TO WARM QUICKLY TODAY...LOW-MID 80S ALONG THE COAST WITH 87-88F
EXPECTED FURTHER INLAND.
&&
.AVIATION...GENERALLY VFR EXPECTED NEXT 24 HOURS.
&&
.MARINE...NORTHERLY FLOW...UP TO 10-15 KNOTS...WILL GRADUALLY
VEER TO THE NORTHEAST THROUGH EARLY THIS AFTERNOON. SEAS 1-2 FEET
THIS MORNING...UP TO 3 FEET BY LATE AFTERNOON WELL OFFSHORE
THE VOLUSIA/BREVARD COUNTY COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 84 63 85 64 / 0 0 0 0
MCO 87 65 87 66 / 0 0 0 0
MLB 85 70 85 69 / 10 10 10 10
VRB 87 69 84 67 / 10 10 10 10
LEE 86 63 87 65 / 0 0 0 0
SFB 87 64 86 66 / 0 0 0 0
ORL 87 68 87 69 / 0 0 0 0
FPR 86 69 85 67 / 10 10 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECAST/AVIATION...ULRICH
IMPACT WEATHER UPDATE....VOLKMER
AREA FORECAST DISCUSSION
NWS MIAMI FL
208 AM EDT THU OCT 15 2015
.AVIATION...
SURFACE FLOW WILL VEER TO THE EAST FOR THURSDAY, INCREASING TO
AROUND 10 KTS THIS AFTERNOON. SHOWERS COULD BE MOVING ONSHORE
THIS MORNING, AS THE HRRR INDICATES, AFFECTING EAST COAST
TERMINALS THROUGH EARLY AFTERNOON. ACTIVITY REACHES THE GULF
COAST DURING THE AFTERNOON HOURS WITH SOME THUNDERSTORMS
POSSIBLE. SHWS MAY EXTEND INTO THE EVENING SO LEFT VCSH FOR THE
EAST COAST INTO TONIGHT. WINDS REMAIN NEAR 10KTS FLL/FXE.
&&
.PREV DISCUSSION... /ISSUED 755 PM EDT WED OCT 14 2015/
AVIATION...
ISOLD LGT/MDT SHRA HAVE DEVELOPED ALONG/NEAR THE SOUTHEAST FL
COAST...PROMPTING INCLUSION OF VCSH AT SOME EAST COAST TAF SITES
THROUGH 01-02Z. WEAK CONVERGENCE OF WINDS AT/NEAR SFC MAY CONTINUE
TO GIVE RISE TO ISOLD SHRA DEVELOPMENT THROUGH THE NEXT SEVERAL
HOURS...BUT IMPACTS AT TAF SITES APPEAR UNLIKELY AT THIS TIME.
ERLY WINDS WILL DEVELOP TOMORROW AT EAST COAST SITES AND SHRA MAY
DEVELOP ESPECIALLY AFTER ~18Z IN SE AREAS...WHICH WAS HANDLED
WITH VCSH FROM KTMB NEWRD TO KOPF TAF LOCATIONS.
/KDW
PREV DISCUSSION... /ISSUED 543 PM EDT WED OCT 14 2015/
UPDATE...
MADE SOME ADJUSTMENTS TO REFLECT CURRENT CONVECTIVE ACTIVITY.
OTHERWISE, NO MAJOR CHANGES. THE ATLANTIC SEA BREEZE DEVELOPED
FAIRLY STRONG THIS AFTERNOON, AND PUSHED WELL INLAND. IT HAS
ALLOWED SOME CONVECTIVE CELLS, INCLUDING A FEW THUNDERSTORMS TO
DEVELOP, MAINLY SOUTH OF FLORIDA CITY AND OFF THE COAST. WITH THE
LOSS OF INSOLATION, CONVECTIVE ACTIVITY SHOULD DIMINISH THIS
EVENING, WITH JUST A SLIGHT CHANCE OF A LIGHT SHOWER ALONG THE
ATLANTIC COAST THIS EVENING.
PREV DISCUSSION... /ISSUED 435 PM EDT WED OCT 14 2015/
DISCUSSION...
CONVECTION HAS HAD A DIFFICULT TIME INITIATING TODAY. A FEW
SHOWERS AND STORMS WERE ABLE TO DEVELOP OVER THE FAR SOUTHERN
AREA, SO HAVE REDUCED POPS EVEN FURTHER THAN PREVIOUS FORECASTS
HAD FOR THIS AFTERNOON.
FOR THE OVERALL WEATHER PATTERN FOR THE NEXT SEVERAL DAYS...THERE
IS AN UPPER LEVEL TROUGH TO THE NORTH, WITH A STRONG 500MB RIDGE
OVER THE WESTERN US. A SFC HIGH IS PROGGED TO MOVE TO THE
SOUTHEAST, OUT OF CANADA, TONIGHT, AND BE OVER THE NORTHERN PLAINS
BY FRIDAY MORNING. IT WILL THEN PROGRESS TO THE GREAT LAKES/OHIO
RIVER VALLEY AREA BY SATURDAY MORNING. THE 500MB TROUGH HOLDS ON
DURING THIS TIME, AT LEAST UNTIL SUNDAY NIGHT. THE SFC HIGH TREKS
TO THE EAST AND BY TUESDAY AFTERNOON, IT IS PROGGED TO BE OFF THE
MID ATLANTIC/ NEW ENGLAND COAST. THROUGH MONDAY, THE 500MB TROUGH
MOVES TO THE EAST AND A RIDGE BUILDS IN OVER THE SOUTHEAST US FOR
THE BEGINNING OF NEXT WEEK.
FOR THE MORE LOCAL EFFECTS...A STALLED BOUNDARY IS STILL OVER
SOUTH FLORIDA, WITH A COLD FRONT SLOWLY PROGRESSING TOWARDS THE
AREA, ALREADY OVER CENTRAL FLORIDA. MODELS SHOW THIS FRONT WILL
WEAKEN AND LOOKS TO END UP COMBINING WITH THE CURRENT BOUNDARY
OVER THE AREA, AND STALL AS WELL. THE EXACT LOCATION WILL LIKELY
BE CRUCIAL FOR CONVECTION OVER THE WEEKEND. THIS WILL LEAD TO A
HIGHER CONFIDENCE THAT AT LEAST SHOWERS WILL DEVELOP EACH DAY,
WITH A LOW CONFIDENCE AS TO WHERE. SO HAVE MOST OF THE CHANCE POPS
OVER THE SOUTHERN HALF OF THE CWA FOR NOW, WITH A FEW EXCEPTIONS
IN THE WESTERN INTERIOR. TOMORROW, AND ABOUT THREE QUARTERS OF
THE CWA WITH CHANCE POPS ON SATURDAY, MAINLY DUE TO LOCATION
UNCERTAINTY. MODELS DID GIVE LIKELY POPS OVER THE ATLANTIC WATERS
FOR FRIDAY, WHICH DO IMPACT THE ATLANTIC COASTAL AREAS AS WELL.
MODELS DO ALSO INDICATE ANOTHER WEAK FRONTAL BOUNDARY MOVING INTO
THE AREA ON SUNDAY. THIS WILL HELP TO KEEP A CHANCE OF RAIN IN THE
FORECAST INTO NEXT WEEK.
AS THE WEEKEND WEARS ON, THE SFC HIGH TO THE NORTH WILL NOT ONLY
TURN THE WIND TO THE NORTHEAST BY THE WEEKEND, BUT WILL BRING
BREEZY CONDITIONS TO SOUTH FLORIDA. BY SUNDAY, MODEL GUIDANCE IS
SHOWING SUSTAINED WIND BETWEEN 10 AND 15 KTS ACROSS THE MAINLAND
AND AROUND 20KTS OVER THE WATER. THIS WIND WILL CONTINUE TO SLOWLY
INCREASE FOR MONDAY, WITH 25-30 KTS CURRENTLY FORECAST OVER THE
ATLANTIC. OVER THE PENINSULA, THE INTERIOR HAS FORECAST WIND
SPEEDS OF 10-15 KTS, WITH THE METRO AREAS SEEING 15-20 KTS. THE
COASTAL COMMUNITIES, ESPECIALLY ALONG THE ATLANTIC COULD SEE 20-25
KTS MONDAY AFTERNOON.
BY THE MIDDLE OF THE WEEK, THE SFC HIGH WILL MOVE TO THE
NORTHEAST. AS IT DOES, IT WILL SLOWLY WEAKEN TO THE NORTH OF
SOUTH FLORIDA, ALLOWING THE PRESSURE GRADIENT OVER SOUTH FLORIDA
TO SLOWLY RELAX BY TUESDAY.
FOR TOMORROW, LOOKING AT SOME CONVECTIVE PARAMETERS, THEY ARE
PRETTY WEAK OVER THE MAINLAND ITSELF, WITH SOMEWHAT BETTER
CONDITIONS OVER THE COASTAL WATERS. THE GFS HAS ALMOST NO CAPE
OVER THE ENTIRE AREA THROUGH THE WEEKEND. THE NAM DOES HAVE PERIOD
OF CAPE OVER SOME OF THE CWA, BUT IS LIKELY OVERDONE, AS USUAL.
THE MODELS DO SHOW PWATS INCREASING THROUGH THE DAY TOMORROW TO
AROUND 2 INCHES. THERE IS THE BOUNDARY IN THE AREA, THERE IS IS A
FOCAL POINT FOR CONVECTION. BUT, NAM MODEL SOUNDINGS ARE SHOWING
THE LAPSE RATES TO BE LESS THAN 6 C/KM TOMORROW, AT MULTIPLE
LOCATIONS ACROSS THE CWA.
SO, GIVEN THE BOUNDARY AND INCREASING MOISTURE, WILL EXPECT SOME
CONVECTIVE DEVELOPMENT. WITH LIMITED CAPE, MOST LIKELY, THE
MAJORITY OF THE ACTIVITY WILL BE SHOWERS. SOME ISOLATED
THUNDERSTORMS MAY BE POSSIBLE, GIVEN THE BOUNDARY AND
THUNDERSTORM ACTIVITY ABLE TO DEVELOP TODAY AND THE ADDITIONAL
BOUNDARY MOVING IN.
SUMMING UP THE FORECAST FOR THE NEXT WEEK, IN ADDITION TO THE
STALLED BOUNDARY OVER THE AREA, THERE WILL BE A COUPLE OF FRONTS
THAT WILL MOVE INTO THE AREA OVER THE NEXT SEVERAL DAYS, KEEPING A
CHANCE OF RAIN AND POSSIBLY A THUNDERSTORM IN THE FORECAST. THE
FRONT ON SUNDAY WILL BE FOLLOWED BY A STRONG HIGH BUILDING TO THE
NORTH, WHICH, IN TURN, WILL BRING BREEZY CONDITIONS TO SOUTH
FLORIDA FOR SUNDAY AND MONDAY, BEFORE WEAKENING ON TUESDAY.
MARINE...
A STALLED FRONT WILL BRING CONTINUED CHANCES FOR SHOWERS AND
STORMS TONIGHT. ANOTHER BOUNDARY WILL MOVE INTO THE AREA TOMORROW,
SOMEWHAT ENHANCING THE CHANCES FOR SHOWERS AND STORMS FOR TOMORROW
AND SATURDAY. A SECOND FRONT WILL MOVE INTO THE AREA ON SUNDAY,
BRINGING INCREASING WIND SPEEDS TO THE REGION. THE WIND WILL BEGIN
TO TURN TOMORROW TO THE NORTHEAST. BY SUNDAY, THE WIND SPEED WILL
INCREASE TO 15-20 KTS, CAUSING BUILDING SEAS OVER THE WEEKEND. BY
MONDAY, THE WIND SPEED IS FORECAST TO INCREASE TO AROUND 25KTS.
BEING OUT OF THE NORTHEAST, THE INTERACTION WITH THE GULF STREAM
WITH CAUSE HIGH, SHORT PERIOD WAVES OF 10-12 FT, WITH OCCASIONAL
WAVES OF 14-15 FT IN THE GULF STREAM. CONDITIONS WILL VERY SLOWLY
IMPROVE AFTER MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 77 85 75 / 20 30 30 20
FORT LAUDERDALE 87 77 83 74 / 20 40 50 40
MIAMI 88 76 84 74 / 30 40 50 40
NAPLES 89 73 86 70 / 20 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...30/KOB
LONG TERM....30/KOB
AVIATION...21/KM
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1012 PM EDT FRI OCT 16 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 306 PM EDT FRI OCT 16 2015
STRONG HIGH PRESSURE WILL BRING DRY WEATHER TO THE OHIO
VALLEY THROUGH THE MIDDLE OF NEXT WEEK. THE COLDEST TEMPERATURES OF
THE SEASON ARE EXPECTED OVER THE WEEKEND WITH A HARD FREEZE LIKELY
FOR MANY AREAS. WARMER WEATHER WILL RETURN STARTING MONDAY AND
CONTINUE THROUGH THE WEEK...WITH THE PASSAGE OF A WEAK FRONT
BRINGING THE NEXT CHANCE FOR A FEW SHOWERS WEDNESDAY NIGHT AND
THURSDAY.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 931 PM EDT FRI OCT 16 2015
UPDATE...
NO CHANGES TO CURRENT FORECAST OR HEADLINES. ANY INCREASED CLOUD
COVERAGE OVER THE NORTHEAST PORTIONS OF THE FORECAST AREA IS
STILL EXPECTED TO HAVE A NEGLIGIBLE AFFECT ON OVERNIGHT LOWS.
TEMPERATURES SHOULD STILL GET CLOSE TO THE FREEZING MARK EVEN
OVER THOSE COUNTIES. UPDATED GRIDS HAVE BEEN SENT.
PREVIOUS DISCUSSION...
THE PRIMARY CHALLENGE FOR THE NEAR TERM IS THE POTENTIAL FOR NEAR-
FREEZING OR SUBFREEZING TEMPS LATE TONIGHT...AND ANY IMPACT FROM
LAKE MICHIGAN INDUCED CU/STRATOCU.
COLD DRY AIR WILL CONTINUE TO OVERSPREAD THE REGION TONIGHT WITH THE
STRONG HIGH PRESSURE SETTLING OVER THE MID MISSISSIPPI VALLEY. BULK
OF THE FORECAST AREA WILL REMAIN MOSTLY CLEAR WITH LIGHT WINDS TO
THE EAST OF THE HIGH CENTER LIKELY TO NOT DETER WIDESPREAD FROST
ACCRUAL AFTER MIDNIGHT.
COMBINATION OF A WAVE ALOFT REINFORCING THE UPPER TROUGH OVER THE
GREAT LAKES OVERNIGHT AND FAVORABLE LOW LEVEL FLOW OFF THE LAKES
WILL KEEP SOME FORM OF LOWER CLOUDS DRIFTING THROUGH NORTHERN
INDIANA AND POSSIBLY WORKING INTO THE NORTHEAST QUARTER OF THE
FORECAST AREA OVERNIGHT. NAM IS MOST AGGRESSIVE IN PUSHING DEEPER
MOISTURE IN THE 925-850MB LAYER INTO AREAS NORTHEAST OF THE INDY
METRO...AND THE RAP IS STARTING TO HINT AT THIS TOWARD DAWN AS WELL.
EVEN WITH BROKEN CLOUDS DRIFTING INTO NORTHEAST COUNTIES LATE...
THOSE AREAS ARE LIKELY TO EXPERIENCE ENOUGH TIME WITH MAINLY CLEAR
SKIES THIS EVENING THAT TEMPS SHOULD STILL MAKE A RUN TOWARDS THE
FREEZING MARK...WITH POTENTIAL TO GO LOWER IF LESS CLOUDS DEVELOP
THAN CURRENTLY THINKING. FOR THAT REASON...HAVE CHOSEN TO UPGRADE
THE ENTIRE FORECAST AREA TO A FREEZE WARNING OVERNIGHT. NOT EVERYONE
IS GOING TO GET TO 32 OR LOWER...BUT STILL FEEL A WIDESPREAD FROST
IS LIKELY FOR MUCH OF THE AREA.
TEMPS...LEANED TOWARDS LOW END OF MOS AND EVEN UNDERCUT IT BY A FEW
DEGREES IN SOME AREAS. WITH THE LACK OF SIGNIFICANT PRECIP OVER THE
LAST SEVERAL WEEKS...TEMP RESPONSE HAS OUTPACED MOS GUIDANCE ON BOTH
HIGHS AND LOWS THE LAST FEW DAYS. EVEN WITH POTENTIAL FOR SOME
CLOUDS LATE...THINK UPPER 20S AND LOWER 30S WILL BE COMMON FOR LOWS
OVERNIGHT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 306 PM EDT FRI OCT 16 2015
FORECAST CHALLENGES ARE ON TEMPS THROUGH THE PERIOD...INCLUDING THE
POTENTIAL FOR THE GROWING SEASON TO COME TO AN OFFICIAL END EARLY
SUNDAY MORNING.
AFOREMENTIONED STRONG HIGH PRESSURE WILL DRIFT ACROSS THE OHIO
VALLEY THROUGH THE SHORT TERM PERIOD...AND BE THE PRIMARY INFLUENCE
ON WEATHER FOR THE NEXT FEW DAYS. SCATTERED CU/STRATOCU MAY BE A BIT
MORE PREVALENT ON SATURDAY...ESPECIALLY ACROSS THE NORTHEAST HALF OF
THE FORECAST AREA...AS AN UPPER LEVEL WAVE PASSES THROUGH THE GREAT
LAKES AND SOUNDINGS/RH PROGS SUPPORT INCREASED MOISTURE IN THE 925-
850MB LAYER. ANY CU WILL DISSIPATE AROUND OR SHORTLY AFTER SUNSET
SATURDAY EVENING AS DRIER AIR AND DEEP SUBSIDENCE OVERSPREADS THE
REGION.
WITH THE HIGH CENTERED OVER THE AREA AND THE 850MB COLD POOL NEARBY
SATURDAY NIGHT...BEST CHANCE AT A WIDESPREAD HARD FREEZE OVER THE
AREA WILL EXIST. HAVE MAINTAINED THE FREEZE WATCH FOR SATURDAY
NIGHT/EARLY SUNDAY FOR NOW...BUT HAVE NO DOUBT THAT THIS WILL BE
UPGRADED TO A WARNING EITHER TONIGHT OR DURING THE DAY SATURDAY.
WARM ADVECTION WILL COMMENCE BEGINNING SUNDAY AND CONTINUE THROUGH
THE REST OF THE SHORT TERM WITH UPPER RIDGING EXPANDING INTO THE
MISSISSIPPI AND OHIO VALLEYS ON MONDAY. TIGHTENING SURFACE PRESSURE
GRADIENT WILL DEVELOP AND PRODUCE BREEZY SOUTHWEST FLOW MONDAY
BETWEEN THE HIGH JUST TO OUR EAST AND A COLD FRONT MOVING THROUGH
THE NORTHERN PLAINS.
TEMPS...GOING ALONG WITH TEMP BEHAVIOR LAST FEW DAYS...LEANED
TOWARDS FAR ENDS OF THE GUIDANCE ON BOTH HIGHS AND LOWS THROUGH MUCH
OF THE PERIOD. UNDERCUT MOS MOST EVERYWHERE SATURDAY NIGHT WITH MANY
AREAS BOTTOMING OUT IN THE 25 TO 30 DEGREE RANGE UNDER IDEAL
RADIATIONAL COOLING SETUP. HIGHS WILL RECOVER BACK INTO THE MID
AND UPPER 60S BY MONDAY AND SOME AREAS IN THE WABASH VALLEY COULD
MAKE A RUN AT 70.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 218 PM EDT FRI OCT 16 2015
MODELS ARE IN GOOD AGREEMENT ON UPPER RIDGING IN PLACE OVER THE AREA
TO BEGIN THE LONG TERM. SOLUTION SPREAD INCREASES BY MID WEEK WITH
DIFFERENCES IN TIMING/PLACEMENT OF A SHORTWAVE MOVING ACROSS THE
NORTHERN PLAINS AND THROUGH THE GREAT LAKES. ACCEPTED INITIALIZATION
WITH ONLY QUALITY CONTROL ADJUSTMENTS RESULTING IN SLIGHT CHANCE
POPS IN THE NORTHERN AND CENTRAL COUNTIES TAPERING TO DRY SOUTH.
TEMPERATURES WILL RUN SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE UPPER
60S TO LOWER 70S AND LOWS IN THE MID 40S TO LOWER 50S.
&&
.AVIATION /DISCUSSION FOR 170300Z IND TAF UPDATE/...
ISSUED AT 1012 PM EDT FRI OCT 16 2015
NO CHANGES NEEDED TO THE TAF.
PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 550 PM EDT FRI OCT 16 2015
HIGH CONFIDENCE THAT VERY DRY BOUNDARY LAYER UNDER HIGH PRESSURE
WILL RESULT IN VFR CONDITIONS THROUGH THE TAF PERIOD. GUSTY
NORTHWEST WINDS WILL DROP TO BELOW 10 KNOTS BY ISSUANCE TIME AND
BECOME LIGHT TO CALM LATE EVENING. THE WINDS WILL PICK UP TO AROUND
10 KNOTS TOMORROW AFTER 15Z...BUT MORE RELAXED PRESSURE
GRADIENT WILL DISCOURAGE GUSTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
FREEZE WARNING FROM 3 AM TO 10 AM EDT SATURDAY FOR INZ021-
028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...TDUD
SHORT TERM...RYAN
LONG TERM....CP
AVIATION...MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
944 PM EDT FRI OCT 16 2015
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 306 PM EDT FRI OCT 16 2015
STRONG HIGH PRESSURE WILL BRING DRY WEATHER TO THE OHIO
VALLEY THROUGH THE MIDDLE OF NEXT WEEK. THE COLDEST TEMPERATURES OF
THE SEASON ARE EXPECTED OVER THE WEEKEND WITH A HARD FREEZE LIKELY
FOR MANY AREAS. WARMER WEATHER WILL RETURN STARTING MONDAY AND
CONTINUE THROUGH THE WEEK...WITH THE PASSAGE OF A WEAK FRONT
BRINGING THE NEXT CHANCE FOR A FEW SHOWERS WEDNESDAY NIGHT AND
THURSDAY.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 931 PM EDT FRI OCT 16 2015
UPDATE...
NO CHANGES TO CURRENT FORECAST OR HEADLINES. ANY INCREASED CLOUD
COVERAGE OVER THE NORTHEAST PORTIONS OF THE FORECAST AREA IS
STILL EXPECTED TO HAVE A NEGLIGIBLE AFFECT ON OVERNIGHT LOWS.
TEMPERATURES SHOULD STILL GET CLOSE TO THE FREEZING MARK EVEN
OVER THOSE COUNTIES. UPDATED GRIDS HAVE BEEN SENT.
PREVIOUS DISCUSSION...
THE PRIMARY CHALLENGE FOR THE NEAR TERM IS THE POTENTIAL FOR NEAR-
FREEZING OR SUBFREEZING TEMPS LATE TONIGHT...AND ANY IMPACT FROM
LAKE MICHIGAN INDUCED CU/STRATOCU.
COLD DRY AIR WILL CONTINUE TO OVERSPREAD THE REGION TONIGHT WITH THE
STRONG HIGH PRESSURE SETTLING OVER THE MID MISSISSIPPI VALLEY. BULK
OF THE FORECAST AREA WILL REMAIN MOSTLY CLEAR WITH LIGHT WINDS TO
THE EAST OF THE HIGH CENTER LIKELY TO NOT DETER WIDESPREAD FROST
ACCRUAL AFTER MIDNIGHT.
COMBINATION OF A WAVE ALOFT REINFORCING THE UPPER TROUGH OVER THE
GREAT LAKES OVERNIGHT AND FAVORABLE LOW LEVEL FLOW OFF THE LAKES
WILL KEEP SOME FORM OF LOWER CLOUDS DRIFTING THROUGH NORTHERN
INDIANA AND POSSIBLY WORKING INTO THE NORTHEAST QUARTER OF THE
FORECAST AREA OVERNIGHT. NAM IS MOST AGGRESSIVE IN PUSHING DEEPER
MOISTURE IN THE 925-850MB LAYER INTO AREAS NORTHEAST OF THE INDY
METRO...AND THE RAP IS STARTING TO HINT AT THIS TOWARD DAWN AS WELL.
EVEN WITH BROKEN CLOUDS DRIFTING INTO NORTHEAST COUNTIES LATE...
THOSE AREAS ARE LIKELY TO EXPERIENCE ENOUGH TIME WITH MAINLY CLEAR
SKIES THIS EVENING THAT TEMPS SHOULD STILL MAKE A RUN TOWARDS THE
FREEZING MARK...WITH POTENTIAL TO GO LOWER IF LESS CLOUDS DEVELOP
THAN CURRENTLY THINKING. FOR THAT REASON...HAVE CHOSEN TO UPGRADE
THE ENTIRE FORECAST AREA TO A FREEZE WARNING OVERNIGHT. NOT EVERYONE
IS GOING TO GET TO 32 OR LOWER...BUT STILL FEEL A WIDESPREAD FROST
IS LIKELY FOR MUCH OF THE AREA.
TEMPS...LEANED TOWARDS LOW END OF MOS AND EVEN UNDERCUT IT BY A FEW
DEGREES IN SOME AREAS. WITH THE LACK OF SIGNIFICANT PRECIP OVER THE
LAST SEVERAL WEEKS...TEMP RESPONSE HAS OUTPACED MOS GUIDANCE ON BOTH
HIGHS AND LOWS THE LAST FEW DAYS. EVEN WITH POTENTIAL FOR SOME
CLOUDS LATE...THINK UPPER 20S AND LOWER 30S WILL BE COMMON FOR LOWS
OVERNIGHT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 306 PM EDT FRI OCT 16 2015
FORECAST CHALLENGES ARE ON TEMPS THROUGH THE PERIOD...INCLUDING THE
POTENTIAL FOR THE GROWING SEASON TO COME TO AN OFFICIAL END EARLY
SUNDAY MORNING.
AFOREMENTIONED STRONG HIGH PRESSURE WILL DRIFT ACROSS THE OHIO
VALLEY THROUGH THE SHORT TERM PERIOD...AND BE THE PRIMARY INFLUENCE
ON WEATHER FOR THE NEXT FEW DAYS. SCATTERED CU/STRATOCU MAY BE A BIT
MORE PREVALENT ON SATURDAY...ESPECIALLY ACROSS THE NORTHEAST HALF OF
THE FORECAST AREA...AS AN UPPER LEVEL WAVE PASSES THROUGH THE GREAT
LAKES AND SOUNDINGS/RH PROGS SUPPORT INCREASED MOISTURE IN THE 925-
850MB LAYER. ANY CU WILL DISSIPATE AROUND OR SHORTLY AFTER SUNSET
SATURDAY EVENING AS DRIER AIR AND DEEP SUBSIDENCE OVERSPREADS THE
REGION.
WITH THE HIGH CENTERED OVER THE AREA AND THE 850MB COLD POOL NEARBY
SATURDAY NIGHT...BEST CHANCE AT A WIDESPREAD HARD FREEZE OVER THE
AREA WILL EXIST. HAVE MAINTAINED THE FREEZE WATCH FOR SATURDAY
NIGHT/EARLY SUNDAY FOR NOW...BUT HAVE NO DOUBT THAT THIS WILL BE
UPGRADED TO A WARNING EITHER TONIGHT OR DURING THE DAY SATURDAY.
WARM ADVECTION WILL COMMENCE BEGINNING SUNDAY AND CONTINUE THROUGH
THE REST OF THE SHORT TERM WITH UPPER RIDGING EXPANDING INTO THE
MISSISSIPPI AND OHIO VALLEYS ON MONDAY. TIGHTENING SURFACE PRESSURE
GRADIENT WILL DEVELOP AND PRODUCE BREEZY SOUTHWEST FLOW MONDAY
BETWEEN THE HIGH JUST TO OUR EAST AND A COLD FRONT MOVING THROUGH
THE NORTHERN PLAINS.
TEMPS...GOING ALONG WITH TEMP BEHAVIOR LAST FEW DAYS...LEANED
TOWARDS FAR ENDS OF THE GUIDANCE ON BOTH HIGHS AND LOWS THROUGH MUCH
OF THE PERIOD. UNDERCUT MOS MOST EVERYWHERE SATURDAY NIGHT WITH MANY
AREAS BOTTOMING OUT IN THE 25 TO 30 DEGREE RANGE UNDER IDEAL
RADIATIONAL COOLING SETUP. HIGHS WILL RECOVER BACK INTO THE MID
AND UPPER 60S BY MONDAY AND SOME AREAS IN THE WABASH VALLEY COULD
MAKE A RUN AT 70.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 218 PM EDT FRI OCT 16 2015
MODELS ARE IN GOOD AGREEMENT ON UPPER RIDGING IN PLACE OVER THE AREA
TO BEGIN THE LONG TERM. SOLUTION SPREAD INCREASES BY MID WEEK WITH
DIFFERENCES IN TIMING/PLACEMENT OF A SHORTWAVE MOVING ACROSS THE
NORTHERN PLAINS AND THROUGH THE GREAT LAKES. ACCEPTED INITIALIZATION
WITH ONLY QUALITY CONTROL ADJUSTMENTS RESULTING IN SLIGHT CHANCE
POPS IN THE NORTHERN AND CENTRAL COUNTIES TAPERING TO DRY SOUTH.
TEMPERATURES WILL RUN SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE UPPER
60S TO LOWER 70S AND LOWS IN THE MID 40S TO LOWER 50S.
&&
.AVIATION /DISCUSSION FOR 170000Z TAF ISSUANCE/...
ISSUED AT 550 PM EDT FRI OCT 16 2015
HIGH CONFIDENCE THAT VERY DRY BOUNDARY LAYER UNDER HIGH PRESSURE
WILL RESULT IN VFR CONDITIONS THROUGH THE TAF PERIOD. GUSTY
NORTHWEST WINDS WILL DROP TO BELOW 10 KNOTS BY ISSUANCE TIME AND
BECOME LIGHT TO CALM LATE EVENING. THE WINDS WILL PICK UP TO AROUND
10 KNOTS TOMORROW AFTER 15Z...BUT MORE RELAXED PRESSURE
GRADIENT WILL DISCOURAGE GUSTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
FREEZE WARNING FROM 3 AM TO 10 AM EDT SATURDAY FOR INZ021-
028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...TDUD
SHORT TERM...RYAN
LONG TERM....CP
AVIATION...MK
AREA FORECAST DISCUSSION
NWS JACKSON KY
1040 PM EDT FRI OCT 16 2015
.UPDATE...
ISSUED AT 1040 PM EDT FRI OCT 16 2015
FORECAST REMAINS ON TRACK TONIGHT...SO DID A QUICK REFRESH TO THE
GRIDS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS.
UPDATE ISSUED AT 745 PM EDT FRI OCT 16 2015
WITH CLEAR SKIES...VALLEY TEMPS ARE DROPPING OFF QUICKLY THIS
EVENING SO NUDGED TEMPS DOWN TO REFLECT THIS TREND. STILL EXPECT
PATCHY FROST TONIGHT WITH LOWS AROUND FREEZING.
OTHERWISE...FORECAST REMAINS ON TRACK. SENT UPDATED GRIDS TO NDFD
AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 220 PM EDT FRI OCT 16 2015
...COLDEST AIR OF THE SEASON THUS FAR ARRIVES THIS WEEKEND...
17Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING INTO THE OHIO
VALLEY. THIS IS BRINGING COOLER AND DRIER AIR INTO EAST KENTUCKY
ON NORTHWEST TO NORTH WINDS OF AROUND 10 MPH WITH GUSTS TO 15
MPH. THE HIGH HAS ALSO CLEARED THE SKIES AND PLENTY OF SUNSHINE IS
SUPPORTING TEMPERATURES IN THE LOWER 60S ATTM WITH DEWPOINTS
MIXING DOWN INTO THE UPPER 20S AND LOWER 30S.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST AS THEY ALL EASE A TIGHTENING TROUGH TO
OUR NORTH...INTO THE GREAT LAKES AND THEN TO EASTERN CANADA.
HEIGHTS WILL FALL THROUGH THE OHIO VALLEY TONIGHT AND SATURDAY AS
THIS TROUGH PASSES...THOUGH ANY ENERGY ASSOCIATED WITH IT WILL
STAY NORTH OF KENTUCKY. GIVEN THE MODEL AGREEMENT HAVE FAVORED THE
HIGHER RESOLUTION HRRR AND NAM12 FOR WEATHER DETAILS...WITH
SPECIAL EMPHASIS ON THE COOP MOS FROM THE GFS FOR POINT BASED LOWS
EACH NIGHT.
SENSIBLE WEATHER WILL BE RATHER QUIET THROUGH THE WEEKEND WITH
THIS MAINLY A TEMPERATURE FORECAST AS EVEN THE CLOUDS WILL BE FEW
AND FAR BETWEEN. HOWEVER...A CANADIAN HIGH PRESSURE SYSTEM IN
PLACE DURING THIS TIME OF YEAR WILL ALSO MEAN CHILLY LOW
TEMPERATURES AND LIKELY FROST. IN FACT...THAT IS EXACTLY WHAT EAST
KENTUCKY IS FACING TONIGHT AND SATURDAY NIGHT. DO EXPECT
TEMPERATURES TO BE MORE UNIFORM TONIGHT THAN TOMORROW NIGHT WITH A
SMALL RIDGE TO VALLEY DIFFERENCE BY MORNING...THOUGH READINGS IN
THE VALLEYS WILL FALL INTO THE LOW 30S WITH AREAS OF FROST
FORMING INTO SATURDAY MORNING. FOR THIS REASON A FROST ADVISORY
HAS BEEN HOISTED TONIGHT FOR THE CWA. AFTER A COOL AND CLOUD FREE
DAY ANOTHER COLD NIGHT WILL SET UP SATURDAY NIGHT WITH A LARGER
RIDGE TO VALLEY TEMPERATURE SPLIT. THIS WILL LIKELY RESULT IN
TEMPS DOWN TO THE MID 20S IN THE SHELTERED VALLEYS AND NEAR
FREEZING ON THE RIDGES. THIS WILL ALSO BRING ABOUT WIDESPREAD
FROST AND POTENTIALLY END THE GROWING SEASON...CERTAINLY EXPECT
THAT TO BE THE CASE IN THE VALLEYS. ACCORDINGLY...WILL CONTINUE
THE FREEZE WATCH FOR SATURDAY NIGHT INTO SUNDAY MORNING.
USED THE SHORTBLEND GUIDANCE AS A STARTING POINT FOR T AND TD
GRIDS INTO SATURDAY MORNING WITH THE SUPERBLEND USED THEREAFTER.
DID MAKE SOME SIGNIFICANT CHANGES TO THE T GRIDS TONIGHT AND
SATURDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE TO VALLEY
DIFFERENCES. AS FOR POPS...WENT ZERO THROUGH THE SHORT TERM
PERIOD...IN LINE WITH ALL GUIDANCE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 215 PM EDT FRI OCT 16 2015
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE REGION THROUGH THE
EXTENDED PERIOD OF THE FORECAST WITH RIDGE/VALLEY SPLITS IN
TEMPERATURES. LOOKS LIKE SOME DRY AFTERNOONS SHAPING UP WITH RH`S
UNDER 25 PERCENT EACH DAY THROUGH AT LEAST WEDNESDAY. LOOKS LIKE
FREEZING TEMPERATURES CAN BE EXPECTED AGAIN SUNDAY NIGHT...SO WILL
LIKELY NEED TO CARRY SOME HEADLINES AGAIN SUNDAY NIGHT. AT THIS
POINT...WILL CONTINUE TO FOCUS ON FROST/FREEZE ISSUES IN THE SHORT
TERM. A WEAK FRONT WILL WASH OUT AS IT MOVES INTO THE OHIO RIVER
VALLEY ON THURSDAY...BUT MODELS CONTINUE TO TREND DRIER WITH THIS
FEATURE...SO WILL MAINTAIN A DRY FORECAST THROUGH NEXT FRIDAY.
OTHERWISE...EXPECT SLOWLY WARMING TEMPERATURES THROUGH NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 740 PM EDT FRI OCT 16 2015
NOW THAT THE FRONT IS WELL SOUTH OF THE AREA SKIES ARE CLEAR
THROUGH EAST KENTUCKY AND CONDITIONS WILL STAY VFR THROUGH THE TAF
PERIOD UNDER THE INFLUENCE OF COOL AND DRY HIGH PRESSURE. AFTER A
GUSTY AFTERNOON...WINDS WILL LESSEN TONIGHT TO BELOW 5 KTS FROM
THE NORTH. HOWEVER...EXPECT WINDS TO PICK BACK UP BY LATE SATURDAY
MORNING...WHERE UP TO 15 KTS GUSTS ARE POSSIBLE...STILL
ORIGINATING FROM THE NORTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 3 AM TO 9 AM EDT SATURDAY FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR
KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...JVM/GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
742 PM EDT FRI OCT 16 2015
.UPDATE...
ISSUED AT 745 PM EDT FRI OCT 16 2015
WITH CLEAR SKIES...VALLEY TEMPS ARE DROPPING OFF QUICKLY THIS
EVENING SO NUDGED TEMPS DOWN TO REFLECT THIS TREND. STILL EXPECT
PATCHY FROST TONIGHT WITH LOWS AROUND FREEZING.
OTHERWISE...FORECAST REMAINS ON TRACK. SENT UPDATED GRIDS TO NDFD
AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 220 PM EDT FRI OCT 16 2015
...COLDEST AIR OF THE SEASON THUS FAR ARRIVES THIS WEEKEND...
17Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING INTO THE OHIO
VALLEY. THIS IS BRINGING COOLER AND DRIER AIR INTO EAST KENTUCKY
ON NORTHWEST TO NORTH WINDS OF AROUND 10 MPH WITH GUSTS TO 15
MPH. THE HIGH HAS ALSO CLEARED THE SKIES AND PLENTY OF SUNSHINE IS
SUPPORTING TEMPERATURES IN THE LOWER 60S ATTM WITH DEWPOINTS
MIXING DOWN INTO THE UPPER 20S AND LOWER 30S.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST AS THEY ALL EASE A TIGHTENING TROUGH TO
OUR NORTH...INTO THE GREAT LAKES AND THEN TO EASTERN CANADA.
HEIGHTS WILL FALL THROUGH THE OHIO VALLEY TONIGHT AND SATURDAY AS
THIS TROUGH PASSES...THOUGH ANY ENERGY ASSOCIATED WITH IT WILL
STAY NORTH OF KENTUCKY. GIVEN THE MODEL AGREEMENT HAVE FAVORED THE
HIGHER RESOLUTION HRRR AND NAM12 FOR WEATHER DETAILS...WITH
SPECIAL EMPHASIS ON THE COOP MOS FROM THE GFS FOR POINT BASED LOWS
EACH NIGHT.
SENSIBLE WEATHER WILL BE RATHER QUIET THROUGH THE WEEKEND WITH
THIS MAINLY A TEMPERATURE FORECAST AS EVEN THE CLOUDS WILL BE FEW
AND FAR BETWEEN. HOWEVER...A CANADIAN HIGH PRESSURE SYSTEM IN
PLACE DURING THIS TIME OF YEAR WILL ALSO MEAN CHILLY LOW
TEMPERATURES AND LIKELY FROST. IN FACT...THAT IS EXACTLY WHAT EAST
KENTUCKY IS FACING TONIGHT AND SATURDAY NIGHT. DO EXPECT
TEMPERATURES TO BE MORE UNIFORM TONIGHT THAN TOMORROW NIGHT WITH A
SMALL RIDGE TO VALLEY DIFFERENCE BY MORNING...THOUGH READINGS IN
THE VALLEYS WILL FALL INTO THE LOW 30S WITH AREAS OF FROST
FORMING INTO SATURDAY MORNING. FOR THIS REASON A FROST ADVISORY
HAS BEEN HOISTED TONIGHT FOR THE CWA. AFTER A COOL AND CLOUD FREE
DAY ANOTHER COLD NIGHT WILL SET UP SATURDAY NIGHT WITH A LARGER
RIDGE TO VALLEY TEMPERATURE SPLIT. THIS WILL LIKELY RESULT IN
TEMPS DOWN TO THE MID 20S IN THE SHELTERED VALLEYS AND NEAR
FREEZING ON THE RIDGES. THIS WILL ALSO BRING ABOUT WIDESPREAD
FROST AND POTENTIALLY END THE GROWING SEASON...CERTAINLY EXPECT
THAT TO BE THE CASE IN THE VALLEYS. ACCORDINGLY...WILL CONTINUE
THE FREEZE WATCH FOR SATURDAY NIGHT INTO SUNDAY MORNING.
USED THE SHORTBLEND GUIDANCE AS A STARTING POINT FOR T AND TD
GRIDS INTO SATURDAY MORNING WITH THE SUPERBLEND USED THEREAFTER.
DID MAKE SOME SIGNIFICANT CHANGES TO THE T GRIDS TONIGHT AND
SATURDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE TO VALLEY
DIFFERENCES. AS FOR POPS...WENT ZERO THROUGH THE SHORT TERM
PERIOD...IN LINE WITH ALL GUIDANCE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 215 PM EDT FRI OCT 16 2015
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE REGION THROUGH THE
EXTENDED PERIOD OF THE FORECAST WITH RIDGE/VALLEY SPLITS IN
TEMPERATURES. LOOKS LIKE SOME DRY AFTERNOONS SHAPING UP WITH RH`S
UNDER 25 PERCENT EACH DAY THROUGH AT LEAST WEDNESDAY. LOOKS LIKE
FREEZING TEMPERATURES CAN BE EXPECTED AGAIN SUNDAY NIGHT...SO WILL
LIKELY NEED TO CARRY SOME HEADLINES AGAIN SUNDAY NIGHT. AT THIS
POINT...WILL CONTINUE TO FOCUS ON FROST/FREEZE ISSUES IN THE SHORT
TERM. A WEAK FRONT WILL WASH OUT AS IT MOVES INTO THE OHIO RIVER
VALLEY ON THURSDAY...BUT MODELS CONTINUE TO TREND DRIER WITH THIS
FEATURE...SO WILL MAINTAIN A DRY FORECAST THROUGH NEXT FRIDAY.
OTHERWISE...EXPECT SLOWLY WARMING TEMPERATURES THROUGH NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 740 PM EDT FRI OCT 16 2015
NOW THAT THE FRONT IS WELL SOUTH OF THE AREA SKIES ARE CLEAR
THROUGH EAST KENTUCKY AND CONDITIONS WILL STAY VFR THROUGH THE TAF
PERIOD UNDER THE INFLUENCE OF COOL AND DRY HIGH PRESSURE. AFTER A
GUSTY AFTERNOON...WINDS WILL LESSEN TONIGHT TO BELOW 5 KTS FROM
THE NORTH. HOWEVER...EXPECT WINDS TO PICK BACK UP BY LATE SATURDAY
MORNING...WHERE UP TO 15 KTS GUSTS ARE POSSIBLE...STILL
ORIGINATING FROM THE NORTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 3 AM TO 9 AM EDT SATURDAY FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR
KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...JVM/GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
655 PM EDT THU OCT 15 2015
.UPDATE...
ISSUED AT 655 PM EDT THU OCT 15 2015
SPRINKLES AND CLOUD COVER CONTINUE THEIR PUSH TOWARD CENTRAL
KENTUCKY THIS EVENING. BUT FOR THE NEAR TERM...SKIES WILL REMAIN
MOSTLY CLEAR AND THE GROUND WILL REMAIN DRY. THAT BEING
SAID...FORECAST REMAINS ON TRACK. DID A QUICK UPDATE TO ALIGN T/TD
GRIDS WITH OBS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM EDT THU OCT 15 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE NOW OVER EASTERN KENTUCKY AND
TENNESSEE WITH CLEAR SKIES...LIGHT WINDS...AND LOW DEWPOINTS IN
PLACE. TO THE NORTHWEST...A LOW PRESSURE AREA IS MOVING THROUGH
THE GREAT LAKES WITH A DRY COLD FRONT CUTTING SOUTHEAST ACROSS THE
UPPER MIDWEST AND MID MISSISSIPPI VALLEY. LOCALLY...THE FULL
SUNSHINE AND DRY AIR HAS ALLOWED TEMPERATURES TO CLIMB INTO THE
UPPER 60S AND LOWER 70S.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST. THEY ALL DEPICT THE BASE OF THE
BROAD NORTHEAST NORTH AMERICAN TROUGH SWEEPING INTO THE OHIO
VALLEY LATE TONIGHT IN CONJUNCTION WITH A SHORTWAVE ROUNDING ITS
WESTERN BASE. THIS WAVE...AND THE ENERGY ASSOCIATED WITH IT...
THEN PASSES OVER EASTERN KENTUCKY FRIDAY MORNING WITH THE WHOLE
TROUGH DESCENDING FURTHER SOUTH THROUGH THE OHIO VALLEY. GIVEN THE
GENERAL MODEL AGREEMENT HAVE FAVORED THE HIGHER RESOLUTION NAM12
AND HRRR FOR WX DETAILS.
SENSIBLE WEATHER WILL FEATURE A MOSTLY CLEAR EVENING WITH LIKELY A
QUICK DROP OFF IN TEMPERATURES FOR THE VALLEYS IN THIS DRY
ENVIRONMENT. THIS WILL SET UP A GOOD RIDGE TO VALLEY TEMPERATURE
SPLIT INTO THE EARLY MORNING HOURS BEFORE INCREASING CLOUDS...WITH
THE APPROACH OF A MOSTLY DRY COLD FRONT...HELP MIX OUT THE COLDER
VALLEY TEMPERATURES. THE FRONT WILL ALSO BRING A SMALL CHANCE FOR
STRAY SHOWERS...BUT MAINLY ONLY A FEW SPRINKLES...TO THE AREA LATE
TONIGHT INTO DAWN. THIS MINOR PCPN THREAT PASSES OUT OF EAST
KENTUCKY EARLY FRIDAY WITH CLEARING ALSO QUICKLY TAKING PLACE.
THANKS TO RETURNING SUNSHINE...HIGHS WILL REBOUND INTO THE LOW TO
MID 60S DESPITE POST FRONTAL CAA THROUGH THE DAY. THIS WILL SET
THE STAGE FOR A CHILLY NIGHT INTO SATURDAY MORNING WITH READINGS
SETTLING IN THE MID 30S FOR MANY VALLEY LOCATIONS AND FROST A GOOD
BET IN THESE SPOTS BY DAWN.
USED THE SHORTBLEND GUIDANCE AS A STARTING POINT INTO FRIDAY
MORNING...BUT DID NEED TO ADJUST THE T GRIDS TO REFLECT THE
VALLEY TEMPERATURE DROP OFF THIS EVENING. FOR THE REST OF THE
SHORT TERM...FOLLOWED THE SUPERBLEND FOR T AND TD GRIDS. AS FOR
POPS...ENDED UP SIMILAR TO RATHER LOW POPS TONIGHT INTO FRIDAY
MORNING AND LOW SINGLE DIGITS OUTSIDE OF THAT TIME FRAME.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EDT THU OCT 15 2015
...HARD FREEZE EXPECTED SATURDAY AND SUNDAY NIGHTS...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE EXTENDED FORECAST
PERIOD. HIGH PRESSURE WILL BUILD OVER THE REGION THROUGH THE
WEEKEND. GIVEN THE DEGREE OF DRY AIR IN PLACE WITH PW`S DROPPING TO
AROUND OF A QUARTER OF AN INCH BY DAYBREAK SUNDAY...FROST/FREEZE
CONCERNS ARE FRONT AND CENTER. MOS GUIDANCE HAS THE COLDER VALLEYS
DIPPING INTO THE MID 20S WHICH SEEMS REASONABLE GIVEN THE HIGH WILL
BE VIRTUALLY OVERHEAD. THUS...WILL CONTINUE TO HIGHLIGHT THE FREEZE
POTENTIAL IN THE HWO AND PLAN TO ISSUE AN SPS TO START HIGHLIGHTING
THE THREAT EVEN MORE. A FREEZE WATCH MAY BE NEEDED IN THE NEXT 24
HOURS. GIVEN THE COLD TEMPERATURES...WE SHOULD SEE FROST DEVELOPMENT
FAVORED OVER FOG...EXCEPT PERHAPS NEAR BODIES OF WATER. WHILE THE
HIGH WILL MOVE TO THE EAST BY SUNDAY NIGHT...GRADIENT WILL STILL
REMAIN SOMEWHAT WEAK TO SUPPORT SIMILAR TEMPERATURES IN THE VALLEYS.
THUS...IT LOOKS LIKE TWO CONSECUTIVE NIGHTS OF FREEZING TEMPERATURES
ARE LIKELY. AS THE HIGH CONTINUES TO SHIFT EAST INTO NEXT WEEK...THE
AIRMASS WILL MODERATE WITH THE THREAT OF FROST/FREEZE CONDITIONS
DEPARTING. DRY WEATHER WILL CONTINUE THROUGH THE WEEK. MODELS SHOW
ANOTHER WEAK FRONT DIVING SOUTH ACROSS THE AREA ON THURSDAY...BUT
12Z GFS HAD THIS FRONT DRY AND THE ECMWF KEEPS THE BETTER FORCING TO
THE NORTH. THUS...KEPT THE FORECAST DRY FOR NOW.
AS FOR TEMPERATURES THE PERIOD WILL START OUT WELL BELOW NORMAL WITH
SOME RECORD LOWS WITHIN REACH SATURDAY AND SUNDAY NIGHT...THEN
SLOWLY WARM AS WE HEAD THROUGH THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 230 PM EDT THU OCT 15 2015
WHILE CONDITIONS WILL BE VFR THROUGH THE PERIOD...A PASSING COLD
FRONT WILL BRING SOME LOWERING CEILINGS BETWEEN 06 AND 12Z. A
STRAY SHOWER CANNOT BE RULED OUT DURING THIS PASSAGE...BUT THE
VAST MAJORITY OF THE AREA WILL REMAIN DRY. WINDS WILL BE AT 5 TO
10 KTS OUT OF THE SOUTHWEST THIS AFTERNOON SHIFTING TO THE
NORTHWEST AND NORTH AFTER THE COLD FRONT PASSES LATE TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
330 PM EDT THU OCT 15 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM EDT THU OCT 15 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE NOW OVER EASTERN KENTUCKY AND
TENNESSEE WITH CLEAR SKIES...LIGHT WINDS...AND LOW DEWPOINTS IN
PLACE. TO THE NORTHWEST...A LOW PRESSURE AREA IS MOVING THROUGH
THE GREAT LAKES WITH A DRY COLD FRONT CUTTING SOUTHEAST ACROSS THE
UPPER MIDWEST AND MID MISSISSIPPI VALLEY. LOCALLY...THE FULL
SUNSHINE AND DRY AIR HAS ALLOWED TEMPERATURES TO CLIMB INTO THE
UPPER 60S AND LOWER 70S.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST. THEY ALL DEPICT THE BASE OF THE
BROAD NORTHEAST NORTH AMERICAN TROUGH SWEEPING INTO THE OHIO
VALLEY LATE TONIGHT IN CONJUNCTION WITH A SHORTWAVE ROUNDING ITS
WESTERN BASE. THIS WAVE...AND THE ENERGY ASSOCIATED WITH IT...
THEN PASSES OVER EASTERN KENTUCKY FRIDAY MORNING WITH THE WHOLE
TROUGH DESCENDING FURTHER SOUTH THROUGH THE OHIO VALLEY. GIVEN THE
GENERAL MODEL AGREEMENT HAVE FAVORED THE HIGHER RESOLUTION NAM12
AND HRRR FOR WX DETAILS.
SENSIBLE WEATHER WILL FEATURE A MOSTLY CLEAR EVENING WITH LIKELY A
QUICK DROP OFF IN TEMPERATURES FOR THE VALLEYS IN THIS DRY
ENVIRONMENT. THIS WILL SET UP A GOOD RIDGE TO VALLEY TEMPERATURE
SPLIT INTO THE EARLY MORNING HOURS BEFORE INCREASING CLOUDS...WITH
THE APPROACH OF A MOSTLY DRY COLD FRONT...HELP MIX OUT THE COLDER
VALLEY TEMPERATURES. THE FRONT WILL ALSO BRING A SMALL CHANCE FOR
STRAY SHOWERS...BUT MAINLY ONLY A FEW SPRINKLES...TO THE AREA LATE
TONIGHT INTO DAWN. THIS MINOR PCPN THREAT PASSES OUT OF EAST
KENTUCKY EARLY FRIDAY WITH CLEARING ALSO QUICKLY TAKING PLACE.
THANKS TO RETURNING SUNSHINE...HIGHS WILL REBOUND INTO THE LOW TO
MID 60S DESPITE POST FRONTAL CAA THROUGH THE DAY. THIS WILL SET
THE STAGE FOR A CHILLY NIGHT INTO SATURDAY MORNING WITH READINGS
SETTLING IN THE MID 30S FOR MANY VALLEY LOCATIONS AND FROST A GOOD
BET IN THESE SPOTS BY DAWN.
USED THE SHORTBLEND GUIDANCE AS A STARTING POINT INTO FRIDAY
MORNING...BUT DID NEED TO ADJUST THE T GRIDS TO REFLECT THE
VALLEY TEMPERATURE DROP OFF THIS EVENING. FOR THE REST OF THE
SHORT TERM...FOLLOWED THE SUPERBLEND FOR T AND TD GRIDS. AS FOR
POPS...ENDED UP SIMILAR TO RATHER LOW POPS TONIGHT INTO FRIDAY
MORNING AND LOW SINGLE DIGITS OUTSIDE OF THAT TIME FRAME.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EDT THU OCT 15 2015
...HARD FREEZE EXPECTED SATURDAY AND SUNDAY NIGHTS...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE EXTENDED FORECAST
PERIOD. HIGH PRESSURE WILL BUILD OVER THE REGION THROUGH THE
WEEKEND. GIVEN THE DEGREE OF DRY AIR IN PLACE WITH PW`S DROPPING TO
AROUND OF A QUARTER OF AN INCH BY DAYBREAK SUNDAY...FROST/FREEZE
CONCERNS ARE FRONT AND CENTER. MOS GUIDANCE HAS THE COLDER VALLEYS
DIPPING INTO THE MID 20S WHICH SEEMS REASONABLE GIVEN THE HIGH WILL
BE VIRTUALLY OVERHEAD. THUS...WILL CONTINUE TO HIGHLIGHT THE FREEZE
POTENTIAL IN THE HWO AND PLAN TO ISSUE AN SPS TO START HIGHLIGHTING
THE THREAT EVEN MORE. A FREEZE WATCH MAY BE NEEDED IN THE NEXT 24
HOURS. GIVEN THE COLD TEMPERATURES...WE SHOULD SEE FROST DEVELOPMENT
FAVORED OVER FOG...EXCEPT PERHAPS NEAR BODIES OF WATER. WHILE THE
HIGH WILL MOVE TO THE EAST BY SUNDAY NIGHT...GRADIENT WILL STILL
REMAIN SOMEWHAT WEAK TO SUPPORT SIMILAR TEMPERATURES IN THE VALLEYS.
THUS...IT LOOKS LIKE TWO CONSECUTIVE NIGHTS OF FREEZING TEMPERATURES
ARE LIKELY. AS THE HIGH CONTINUES TO SHIFT EAST INTO NEXT WEEK...THE
AIRMASS WILL MODERATE WITH THE THREAT OF FROST/FREEZE CONDITIONS
DEPARTING. DRY WEATHER WILL CONTINUE THROUGH THE WEEK. MODELS SHOW
ANOTHER WEAK FRONT DIVING SOUTH ACROSS THE AREA ON THURSDAY...BUT
12Z GFS HAD THIS FRONT DRY AND THE ECMWF KEEPS THE BETTER FORCING TO
THE NORTH. THUS...KEPT THE FORECAST DRY FOR NOW.
AS FOR TEMPERATURES THE PERIOD WILL START OUT WELL BELOW NORMAL WITH
SOME RECORD LOWS WITHIN REACH SATURDAY AND SUNDAY NIGHT...THEN
SLOWLY WARM AS WE HEAD THROUGH THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 230 PM EDT THU OCT 15 2015
WHILE CONDITIONS WILL BE VFR THROUGH THE PERIOD...A PASSING COLD
FRONT WILL BRING SOME LOWERING CEILINGS BETWEEN 06 AND 12Z. A
STRAY SHOWER CANNOT BE RULED OUT DURING THIS PASSAGE...BUT THE
VAST MAJORITY OF THE AREA WILL REMAIN DRY. WINDS WILL BE AT 5 TO
10 KTS OUT OF THE SOUTHWEST THIS AFTERNOON SHIFTING TO THE
NORTHWEST AND NORTH AFTER THE COLD FRONT PASSES LATE TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1236 AM CDT THU OCT 15 2015
.UPDATE...
ISSUED AT 807 PM CDT WED OCT 14 2015
A WEAK SFC TROF WAS JUST MOVING INTO NW WI AT 01Z. SOME MID AND
HIGH CLOUDS PERSISTED WITH THE TROF. MOSTLY CLEAR BEHIND THE TROF.
THE HRRR IS NOT DOING A VERY GOOD JOB ATTM AS IT CONTINUES TO
GENERATE SHOWERS WHERE THE MID CLOUDS ARE IN NW WI. NAM12/RAP KEEPS
THE AREA DRY THROUGH 12Z. THE ARW/NMM IS LEANING THIS WAY BUT
ATTEMPTS TO BRING IN SOME SHOWERS TO LAKE COUNTY AFTER 09Z. WILL
FOLLOW THE DRY APPROACH AND HAVE REMOVED POPS TONIGHT. ALSO LOWERED
THEM A BIT THURSDAY MORNING...BUT MAINTAINED THE POPS THE REST OF
THE MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 349 PM CDT WED OCT 14 2015
A COLD FRONT CURRENTLY PUSHING SOUTH OVER THE CANADIAN PRAIRIES WILL
REACH NORTHERN MINNESOTA TOMORROW MORNING. THE FRONT WILL QUICKLY
DROP ACROSS THE NORTHLAND THROUGH THE DAY...BRINGING FALLING OR
STEADY AFTERNOON TEMPERATURES AND GUSTY NORTHWEST WINDS OF 25-30 KTS.
CLOUDY SKIES AND SCATTERED INSTABILITY SHOWERS WILL ALSO ACCOMPANY
THE COLD AIR MASS TOMORROW.
GUIDANCE IS IN GOOD AGREEMENT H85 TEMPS THURSDAY MORNING BEGIN IN
THE SINGLE DIGITS...FALLING BELOW FREEZING ACROSS MUCH OF THE
NORTHLAND BY THE EVENING HOURS. MEANWHILE...H50 READINGS APPROACHING
NEGATIVE 30C WILL PROVIDE ENOUGH INSTABILITY TO TRIGGER SHOWERS.
LATEST NAM/GFS BUFR SOUNDINGS CONTINUE TO SHOW CAPE IN THE SATURATED
LAYER ABOVE THE FREEZING LEVEL. ALTHOUGH MINIMAL...ITS ENOUGH TO
SUPPORT A BRIEF WINTRY MIX OF LIGHT RAIN/SNOW/GRAUPEL ACROSS THE
NORTHERN ZONES LATE IN THE DAY. PRECIPITATION AMOUNTS WILL BE LIGHT
WITH A DUSTING OF SNOW ACCUMULATION POSSIBLE IN THE HIGHER
ELEVATIONS OF LAKE AND COOK COUNTIES.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 PM CDT WED OCT 14 2015
THE UPPER LEVEL TROF WILL DIVE SOUTH ACROSS THE UPPER MIDWEST
THURSDAY NIGHT... CONTINUING TO DIG ACROSS THE OHIO RIVER VALLEY
FRIDAY AND SATURDAY BEFORE SLIDING EASTWARD SUNDAY. AT THE LOWER
LEVELS... SFC HIGH FROM SASKATCHEWAN WILL BUILD IN FROM THE WEST AND
WILL PERSIST THROUGH EARLY SUNDAY BEFORE ALSO MOVING EASTWARD TO THE
APPALACHIANS. THE COMBINATION BETWEEN THESE TWO FEATURES WILL BRING
IMPRESSIVE COLD AIR ADVECTION TO THE NORTHLAND... SETTING THE STAGE
FOR THE COLDEST NIGHT SO FAR THIS SEASON... WITH WIDESPREAD MID TO
UPPER 20S EXPECTED ACROSS MUCH OF THE NORTHLAND... AND AROUND
FREEZING NEAR LAKE SUPERIOR ON THURSDAY NIGHT. THE GFS HAS 850 MB
TEMPS PEGGED AROUND -6C TO -10C FOR MUCH OF THE GREAT LAKES REGION
DURING THIS TIME. THIS MAY BE THE FIRST HARD FREEZE FOR MANY
LAKESIDE AREAS. IN ADDITION... A DISTURBANCE ON THE WESTERN FRINGE OF
THE UPPER TROF THAT BROUGHT RAIN THE THE NORTHLAND THURSDAY
AFTERNOON WILL LINGER INTO THE NIGHT... AND WILL HAVE THE
POSSIBILITY OF CHANGING OVER TO SNOW SHOWERS ACROSS THE IRON RANGE
AND NORTHERN ARROWHEAD THURSDAY NIGHT.... AND ACROSS THE GOGEBIC
MOUNTAINS. THE COLD AIRMASS WILL LINGER FRIDAY WITH HIGHS IN THE
30S AND 40S EXPECTED... BUT A GRADUAL WARM UP IS EXPECTED AS THE
UPPER TROF MOVES EASTWARD LATE SUNDAY... TAKING THE COLD AIR WITH
IT... BRINGING BACK HIGHS IN THE 50S.
IN THE EXTENDED... UPPER LEVEL RIDGING RETURNS EARLY NEXT WEEK
BRINGING BACK AVERAGE TO ABOVE AVERAGE TEMPS AS A DISTURBANCE BRINGS
RAIN TO THE NORTHLAND MONDAY AFTERNOON... AND A COLD FRONT ARRIVES
TUESDAY COOLING TEMPS BACK DOWN TO THE MID 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1234 AM CDT THU OCT 15 2015
VFR AND LLWS AT THE OUT SET OF THE FORECAST WITH SOME MID CLOUDS
NEARBY. GUSTY NW WINDS AGAIN BY 15Z WITH APPROACHING COLD FRONT.
FRONT SHOULD MOVE PAST THE TERMINALS IN THE MORNING. A FEW SHOWERS
WILL ACCOMPANY THE FRONT...BUT TIMING IS DIFFICULT EXCEPT AT INL
AS SHOWERS WILL BE SPORADIC. HAVE A VCSH MENTION EXCEPT AT BRD
WHICH WILL NOT BE AFFECTED BY SHOWERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 39 54 29 41 / 0 20 10 0
INL 37 49 25 39 / 0 50 10 0
BRD 39 54 29 43 / 0 10 0 0
HYR 37 55 29 42 / 0 20 10 10
ASX 40 55 31 43 / 0 30 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...GRANING
LONG TERM...MCLOVIN
AVIATION...GSF/LE
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
748 PM PDT FRI OCT 16 2015
.SYNOPSIS...A SUCCESSION OF LOW PRESSURE SYSTEMS WILL BRING SHOWERS
AND THUNDERSTORMS AT TIMES TO MUCH OF THE REGION THROUGH SUNDAY
EVENING. ANOTHER LARGE CIRCULATION IS NOW EXPECTED TO DIVE INTO THE
GREAT BASIN MONDAY AND SETTLE OVER THE MOJAVE DESERT REGION TUESDAY
AND WEDNESDAY BRINGING UNSETTLED WEATHER WITH TEMPERATURES A LITTLE
BELOW NORMAL.
&&
.UPDATE...SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO DEVELOP AND
MOVE NORTH ACROSS THE REGION THIS EVENING. TWO MAIN EAST-WEST BANDS
OF CONCERN AT THIS TIME.
THE FIRST STRETCHES FROM NEAR BAKER CA EAST TOWARD FLAGSTAFF.
HEAVIER CELLS WITHIN THIS BAND HAVE HAD RAIN RATES OF AROUND 1.00"
PER HOUR...BUT WITH RELATIVELY QUICK STORM MOTION AND A LACK OF
SIGNIFICANT TRAINING THEY`VE ONLY MANAGED AROUND 0.25" OF TOTAL
RAINFALL AS THEY PASS. THIS BAND WILL CONTINUE TO MOVE NORTH INTO
SOUTHERN NEVADA...LIKELY DECREASING IN STRENGTH AS IT ENCOUNTERS
MORE STABLE AIR. STILL..THE LAS VEGAS AREA COULD SEE A FEW SHOWERS
OR ISOLATED THUNDERSTORMS BETWEEN ROUGHLY 830 AND 11 THIS EVENING.
THE SECOND BAND IS IN THE DEVELOPMENT STAGE OVER LA PAZ COUNTY. THIS
BAND IS LIKELY TO PUSH NORTH-NORTHWEST INTO MOHAVE AND EASTERN SAN
BERNARDINO COUNTIES OVER THE NEXT 2-4 HOURS. THERE IS FAIRLY GOOD
CLUSTERING OF MODELS SOLUTIONS INDICATING THAT THIS FEATURE WILL
PUSH INTO CLARK AND NORTHERN MOHAVE COUNTIES DURING THE EARLY
MORNING HOURS...THEN CONTINUING NORTH THROUGH THE REMAINDER OF THE
MORNING. SHORT RANGE RAP GUIDANCE INDICATES INCREASING LOW LEVEL
MOISTURE WITH THIS BAND...WHICH COULD RESULT IN MORE EFFICIENT RAIN
PRODUCTION AND HIGHER RAIN RATES. MODEST INSTABILITY WILL CONTINUE
TO ALLOW EMBEDDED THUNDERSTORMS TO DEVELOP IN THIS SECOND
BAND...MOST NOTABLY ALONG THE COLORADO RIVER VALLEY.
THE SHORT RANGE FORECAST HAS BEEN UPDATED TO REFLECT THE LATEST
TRENDS AND SHORT RANGE GUIDANCE. WILL CONTINUE TO MONITOR AND UPDATE
AS NEEDED.
ANOTHER ISSUE THAT WILL BE ADDRESSED OVERNIGHT IS THE POTENTIAL FOR
YET ANOTHER WAVE DIGGING SOUTH INTO THE REGION AND CONTINUING THE
WIDESPREAD SHOWER/THUNDERSTORM ACTIVITY INTO TUESDAY AND WEDNESDAY.
&&
.AVIATION...FOR MCCARRAN...SCATTERED SHOWERS CONTINUE TO DRIFT
ACROSS THE REGION. THE NEXT BATCH MAY IMPACT THE LAS VEGAS VALLEY
BETWEEN 300Z-600Z...WITH CIGS GENERALLY REMAINING ABOVE 6-8K FEET.
ISOLATED THUNDERSTORMS CANNOT BE RULED OUT. ADDITIONAL ROUNDS OF
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AFTER MIDNIGHT AND INTO
SATURDAY MORNING. CIGS COULD DROP TO 4-6K FEET WITH THESE STORMS.
WINDS ARE EXPECTED TO TREND TOWARD TYPICAL DIURNAL DIRECTIONS AT 8
KTS OR LESS BUT WILL GUST TO AROUND 20-25 KTS FROM VARYING
DIRECTIONS IN THE VICINITY OF STORMS. THE CHANCE FOR SHRA/TSRA WILL
CONTINUE THROUGH EARLY NEXT WEEK WITH SUNDAY AFTERNOON SEEING THE
MOST COVERAGE. CIGS/VSBYS REDUCED TO MVFR OR LOWER AT TIMES AS WELL
AS OCCASIONAL MOUNTAIN OBSCURATIONS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SHRA/TSRA ARE POSSIBLE THROUGH TONIGHT WITH THE MOST
COVERAGE ACROSS MOHAVE COUNTY. SHOWERS AND THUNDERSTORMS WILL BE
FAVORED OVER CLARK...LINCOLN AND MOHAVE COUNTIES ON SATURDAY. CIGS
WILL MAINLY BE 6K-10K FEET IN AND NEAR SHRA/TSRA OTHERWISE 10K-14K
FEET. VSBY MAY BE REDUCED TO MVFR OR LOWER WITH GUSTY AND ERRATIC
WINDS POSSIBLE IN AND NEAR ANY SHRA/TSRA. OTHERWISE EXPECT WINDS TO
TREND TOWARD TYPICAL DIURNAL DIRECTIONS AT 10 KTS OR LESS. MOUNTAIN
OBSCURATIONS ARE POSSIBLE. SHRA/TSRA ARE EXPECTED ONCE AGAIN ON
SUNDAY...WITH THE MOST COVERAGE EXPECTED ACROSS NYE, CLARK, LINCOLN
AND MOHAVE COUNTIES. CIGS/VSBY REDUCED TO MVFR OR LOWER AS WELL AS
MOUNTAIN OBSCURATIONS POSSIBLE.
&&
.PREV DISCUSSION...
320 PM PDT FRI OCT 16 2015
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT.
THE INGREDIENTS REMAIN IN PLACE FOR PERIODS OF SHOWERS AND EMBEDDED
THUNDERSTORMS TO DEVELOP OVER MUCH OF THE THE FORECAST AREA TONIGHT
THROUGH SUNDAY. LIGHT TO MODERATE SHOWERS WILL BE COMMON FOR MOST
AREAS. ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES OF 1.0-1.4 INCHES
WILL LEAD TO RAINFALL RATES OVER 1 INCH PER HOUR WITH SOME
THUNDERSTORMS. THE DIFFICULTY LIES IN PINNING DOWN WHEN SPECIFIC
AREAS WILL SEE SIGNIFICANT RAINFALL. THE FLASH FLOOD WATCH FOR
SOUTHERN NEVADA AND SURROUNDING ZONES IN NORTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA WILL REMAIN IN EFFECT THROUGH SUNDAY EVENING TO
HIGHLIGHT THIS POTENTIAL.
THE MODELS ARE IN GOOD GENERAL AGREEMENT WITH THE EVOLUTION OF THE
PATTERN THROUGH SUNDAY. THE TWO MAIN FEATURES THAT WILL DRIVE THE
WEATHER ARE THE UPPER LOW CURRENTLY OVER CENTRAL CALIFORNIA AND AN
EASTERN PACIFIC TROUGH WITH ITS BASE NEAR 35N/135W. THE CENTRAL
CALIFORNIA LOW IS FORECAST TO TRANSITION FROM A CLOSED CIRCULATION
TO AN OPEN SYSTEM TONIGHT AND BEGIN HEADING EAST IN RESPONSE TO THE
PACIFIC TROUGH. THIS WILL PRODUCE INCREASING UPWARD FORCING ACROSS
MOHAVE...CLARK AND LINCOLN COUNTIES LATE TONIGHT THROUGH SATURDAY
MORNING LEADING TO MORE EXTENSIVE SHOWERS AND EMBEDDED
THUNDERSTORMS. AS THE TROUGH AXIS PASSES SATURDAY AFTERNOON AND
EVENING...WE SHOULD SEE SHOWER COVERAGE DIMINISH.
THE NEXT TROUGH WILL THEN BEGIN TO EXERT ITS INFLUENCE EARLY SUNDAY
MORNING WITH A 50-60 KNOT CURVED JET MOVING OVER SOUTHERN
CALIFORNIA/NEVADA PRECEDING THE BASE OF THE TROUGH. BROAD UPWARD
FORCING WILL ACT ON SUBSTANTIAL LOW AND MID LEVEL MOISTURE LINGERING
OVER SOUTHERN NEVADA AND NORTHWEST ARIZONA TO PRODUCE THE MOST
EXTENSIVE PRECIPITATION COVERAGE OF THE WEEKEND. CONSIDERABLE SHEAR
WILL SUPPORT MORE ORGANIZED STORMS SUNDAY MOVING FROM SOUTHWEST TO
NORTHEAST. THE BROAD ENERGETIC TROUGH WILL SUPPORT SHOWERS AND
ISOLATED THUNDERSTORMS MUCH OF SUNDAY NIGHT THEN A DECREASE IN
COVERAGE FROM WEST TO EAST EARLY MONDAY MORNING. SNOW LEVELS WILL
ONLY LOWER TO AROUND 10000 FEET SUNDAY AFTERNOON AND NIGHT SO ONLY
THE HIGH PEAKS OF THE SOUTHERN SIERRA...WHITE MOUNTAINS AND SPRING
MOUNTAINS WILL SEE SOME SNOW. TEMPS WERE LOWERED A FEW DEGREE BASED
ON THE LATEST GUIDANCE WITH HIGHS RUNNING SEVERAL DEGREES BELOW
NORMAL.
.LONG TERM...MONDAY THROUGH FRIDAY.
THE 12Z MEDIUM RANGE MODELS ARE ALL IN QUITE GOOD AGREEMENT THAT
ANOTHER SHORTWAVE TROUGH APPROACHING THE PACIFIC NORTHWEST MONDAY
MORNING WILL DIVE INTO THE MEAN TROUGH LINGERING OVER NEVADA. THIS
ADDITIONAL SHOT OF ENERGY WILL SPIN IT UP INTO A CLOSED LOW CENTERED
OVER THE LOWER COLORADO RIVER VALLEY ALONG THE CALIFORNIA/ARIZONA
BORDER WHICH WILL BE NEARLY STATIONARY TUESDAY AND WEDNESDAY. THIS
WILL KEEP COOLER CONDITIONS AROUND THROUGH AT LEAST MID WEEK ALONG
WITH A CHANCE OF SHOWERS CONTINUING OVER NORTHWEST ARIZONA AND THE
COLORADO RIVER VALLEY AT THE LEAST. IT IS FORECAST TO SLOWLY PULL
AWAY THURSDAY LEAVING A DRY NORTHWEST FLOW IN ITS WAKE. THE LATEST
ECMWF INDICATES ANOTHER DEEP TROUGH DIVING INTO THE SOUTHWEST FRIDAY
INTO NEXT WEEKEND. IT COULD BE ANOTHER ACTIVE WEEKEND OF WEATHER.
&&
.CLIMATE...RECORD HIGH MINIMUM TEMPERATURES ARE ALSO POSSIBLE FOR
LAS VEGAS TODAY AND SATURDAY.
DATE VALUE/YEAR
-----------------------------
10/16 66/2010*
10/17 67/1991
* TIE FROM PREVIOUS YEARS.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE REQUIRED
THROUGH MONDAY.
&&
$$
UPDATE/AVIATION...WOLCOTT
PREV DISCUSSION...ADAIR
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS PORTLAND OR
859 PM PDT FRI OCT 16 2015
.SYNOPSIS...AN UPPER LEVEL TROUGH OFF THE COAST THIS EVENING WILL
CONTINUE TO DRIFT EAST TONIGHT. THE TROUGH EVENTUALLY SPLITS INTO TWO
PIECES SATURDAY...WITH THE STRONGEST PORTION SETTLING OFF THE FAR
SOUTH OREGON COAST SATURDAY EVENING. MOIST SOUTHEAST TO SOUTH FLOW
ALOFT TONIGHT THROUGH SATURDAY WILL ALLOW THE AIR MASS TO BECOME MORE
MOIST WITH TIME. THE UPPER LOW WILL PRODUCE SHOWERS THROUGH THE
WEEKEND. ANOTHER WEATHER SYSTEM IS EXPECTED TO IMPACT THE AREA
MONDAY. THIS SYSTEM COULD ALSO WEAKEN AS IT REACHES THE COAST. UPPER
LEVEL HIGH PRESSURE RETURNS TUESDAY AND MUCH OF WEDNESDAY. ANOTHER
FRONT IS EXPECTED ON THURSDAY.
&&
.SHORT TERM...FAIRLY COMPLEX WEATHER PATTERN DEVELOPING OVER THE
FORECAST AREA TONIGHT AND SATURDAY. WATER VAPOR IMAGERY SHOWS AN
ELONGATED UPPER TROUGH EXTENDING FROM ABOUT 50N 140W TO 35N 132W THIS
EVENING. APPEARS THAT A LOW CENTER IS DEVELOPING NEAR 40N 130W.
STRONG UPPER RIDGE CENTERED OVER THE NRN ROCKIES WITH ANOTHER TROUGH
AND ASSOCIATED LOW CENTER CIRCULATION CENTERED OVER CENTRAL AND SRN
CALIFORNIA. MEANWHILE...SOUTHEAST TO SOUTH FLOW ALOFT INTO THE
FORECAST AREA HAS ALLOWED THE AIR MASS TO BECOME MORE MOIST WITH
TIME. THE 00Z KSLE SOUNDING INDICATED 0.96 INCHES PRECIPITABLE WATER.
THERE HAVE BEEN A FEW LIGHTNING STRIKES IN NRN KLAMATH COUNTY EARLIER
THIS EVENING AND A COUPLE WELL OFFSHORE. KRTX DUAL-POL DOPPLER RADAR
STARTING TO SEE AN INCREASE IN 30DBZ OR GREATER RETURNS AFTER
02Z...WITH A FEW 40-45 DBZ ECHOES IN SOUTH-CENTRAL LINCOLN COUNTY AND
OVER THE CENTRAL OREGON CASCADES AND FOOTHILLS. ALSO...INFRA-RED
IMAGERY AT 03Z SHOWING COOLING CLOUD TOPS IN AN AREA FROM EASTERN
CLACKAMAS COUNTY TO SOUTHEAST LINN COUNTY. THIS LIKELY DUE TO
INTERACTION WITH THE REMNANTS OF THE THERMALLY-INDUCED SURFACE
TROUGH.
MAIN FORECAST CHALLENGE TONIGHT IS POPS. BASED ON LATEST SATELLITE
AND RADAR TRENDS...DECIDED TO UP POPS THIS EVEING AND OVERNIGHT AND
USE COVERAGE INSTEAD OF UNCERTAINTY TERMS. THERE DOES NOT APPEAR TO
BE ANY OBVIOUS SHORT-WAVE WITHIN THE SOUTHEAST TO SOUTH FLOW ALOFT TO
GENERATE EXTRA LIFT OR FORCING. THE NAM AND HRRR WANT TO GENERATE A
BAND OF SHOWER ACTIVITY FROM THE LANE COUNTY CASCADES NORTHWEST TO
THE FAR NORTH OREGON COAST BY 06Z THEN SLOWLY SHIFT THIS AREA NORTH
AND A LITTLE EAST. THE SPC STORM-SCALE ENSEMBLE OF OPPORTUNITY
...SSEO...SHOWS AN AREA FROM EASTERN LANE COUNTY TO WESTERN LINN
COUNTY AS A FAVORED AREA FOR SHOWER ACTIVITY BY 09Z.
THE 00Z NAM CONTINUES THE TREND OF THE PREVIOUS 12Z AND 18Z RUNS
SHOWING THE OFFSHORE UPPER TROUGH STRETCHING NORTH TO SOUTH TONIGHT
AND SATURDAY MORNING AS IT MOVES CLOSER TO THE COAST. THE 00Z NAM
SHOWS THE STRONGER SOUTHERN PIECE CLOSING OFF NEAR THE FAR SOUTH
OREGON COAST BY 03Z SUN. NAM ALSO IMPLIES DIFFLUENT 500 MB FLOW
SQUARELY OVER THE N WILLAMETTE VALLEY AND INTO THE SW WA LOWLANDS
LATE SAT AFTERNOON. MODELS CONTINUE TO IMPLY AN UNSEASONALLY MOIST
AIR MASS...WITH 1.3 INCH TOTAL PRECIPITABLE WATER VALUES. RAISED SAT
POPS A BIT MORE...BUT MID SHIFT MAY WANT TO GO EVEN HIGHER. THE UPPER
LOW SITS OVER SW OREGON AND FAR NW CALIFORNIA SAT NIGHT THEN SLOWLY
DRIFTS SE SUNDAY. MOST FAVORED TIME FRAME FOR GREATEST SHOWER
COVERAGE LOOKS TO BE SAT AFTERNOON THROUGH AND EVENING. SHOWERS
MAY BE HEAVY AT TIMES DUE TO THE ABNORMALLY MOIST AIR MASS AND WEAK
MID-LEVEL FLOW...BUT THE SPORADIC AND UNPREDICTABLE NATURE OF
SHOWERS RESULTS IN A VERY CHALLENGING AND LOW CONFIDENCE QPF
FORECAST.
THERE ARE SOME MODEL DISCREPANCIES WITH THE NEXT FRONT EXPECTED FOR
MONDAY...BUT LEANED TOWARDS THE MORE PERSISTENT ECMWF MODEL THAT
FORECASTS THE FRONT WILL SPREAD WIDESPREAD RAIN ACROSS SW WASHINGTON
AND NW OREGON MONDAY MORNING THROUGH MONDAY AFTERNOON. WEISHAAR
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY...POST FRONTAL SHOWERS
WILL SLOWLY TAPER OFF LATE MONDAY AS UPPER LEVEL RIDGING BEGINS TO
BUILD INTO THE PACIFIC NORTHWEST. THIS WILL BRING A BRIEF RETURN OF
DRY WEATHER TUESDAY AND MOST OF WEDNESDAY...WITH TEMPERATURES LIKELY
WARMING INTO THE UPPER 60S WEDNESDAY AFTERNOON ACROSS MUCH OF THE
INTERIOR VALLEY. THE RIDGE LOOKS TO SLOWLY BREAKDOWN AND MOVE EAST
THROUGH THE DAY WEDNESDAY AHEAD OF AN APPROACHING UPPER LEVEL
TROUGH. MODEL GUIDANCE CONTINUES TO SHOW A WEAK COLD FRONT MOVING
ACROSS THE REGION LATE WEDNESDAY/EARLY THURSDAY. THIS FRONT SHOULD
BRING THE RETURN OF SEASONAL TEMPERATURES AND SOME LIGHT RAIN TO THE
REGION. A DECENT COLD POOL ALOFT COULD ALSO ALLOW SNOW LEVELS TO
LOWER BELOW 6000 FT. A PROGRESSIVE WEATHER PATTERN LIKELY CONTINUES
THROUGH THE WEEKEND. /64
&&
.AVIATION...IFR CONDITIONS ALONG THE COAST SHOULD REMAIN IFR
OVERNIGHT...IMPROVING TO LOW MVFR WITH CIGS LIFTING AROUND MIDDAY
SATURDAY. INLAND AREAS...VFR PREVAILING TONIGHT WITH CIGS
LOWERING AFTER MIDNIGHT AS SHOWERS CONTINUE MOVING NORTHWARD INTO
THE AREA. SHOWERS FOR THE MOST PART ARE NOT REACHING THE GROUND
CURRENTLY...BUT AS THE LOWER LEVELS ACQUIRE MOISTURE OVERNIGHT
LIGHT SHOWERS WILL START TO MAKE IT TO THE GROUND. THIS WILL ALSO
CAUSE CIGS TO CONTINUE TO LOWER EARLY SATURDAY...WITH A SMALL
CHANCE CIGS DROP TO MVFR WITH SHOWERS AROUND 14Z-17Z. CIGS FAIRLY
SOLID THROUGH THE DAY SATURDAY...RISING TO AROUND 5000-7000 FT
INLAND. SCATTERED -SHRA CONTINUE THROUGH SATURDAY AFTERNOON.
KPDX AND APPROACHES...VFR CONDITIONS WITH CIGS GRADUALLY LOWERING
TO AROUND 5000 FT EARLY SATURDAY. CHANCE OF -SHRA INCREASES AFTER
MIDNIGHT...WITH SMALL CHANCE CIGS LOWER TO MVFR AROUND 14Z-17Z.
-MCCOY
&&
.MARINE...A WEAKENING FRONT CROSSES THE WATERS SATURDAY AND IS
LOOKING LIKE IT WILL SPIN UP A WEAK SURFACE LOW JUST OFF THE
CENTRAL OREGON COAST. LOW SHOULD SLOWLY MOVE ACROSS THE WATERS
MIDDAY SATURDAY THROUGH SATURDAY EVENING. WINDS SHOULD STAY AROUND
10 TO 15 KT...BUT A FEW GUSTS TO 20 KT POSSIBLE SATURDAY MORNING
OUT AHEAD OF THE LOW PRESSURE CENTER MAINLY IN THE CENTRAL OREGON
WATERS. WINDS SHOULD STAY BELOW SMALL CRAFT ADVISORY CRITERIA WITH
THIS SYSTEM. NEXT SYSTEM MOVES THROUGH EARLY MONDAY. THIS SYSTEM
HAS A BETTER CHANCE OF BRINGING SMALL CRAFT WINDS ACROSS THE
WATERS...BUT MODELS STILL DO NOT HAVE A GOOD HANDLE ON THE TRACK
OR STRENGTH OF THIS FEATURE AT THIS TIME.
SEAS CURRENTLY AROUND 3 FT WILL GRADUALLY BUILD OVERNIGHT AND
THROUGH THE DAY SATURDAY AS LARGER SWELL MOVES IN...REACHING 7 TO
8 FT SATURDAY NIGHT. SEAS SHOULD REMAIN BELOW 10 FT THROUGH THE
WEEKEND WITH BOTH THE FRONTAL SYSTEMS MOVING THROUGH. -MCCOY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
525 PM EDT THU OCT 15 2015
.SYNOPSIS...
AN AMPLIFIED UPPER LEVEL TROUGH OVER EASTERN CANADA WILL DOMINATE
THE REGIONAL WEATHER PATTERN THROUGH THE WEEKEND WITH TEMPERATURES
AVERAGING BELOW NORMAL. A WEAK FRONT WILL MOVE THROUGH TOMORROW
AND FROST/FREEZE CONDITIONS THIS WEEKEND WILL LIKELY BRING AN END
TO THE GROWING SEASON. THE SEASONABLY COLD NORTHWEST FLOW WILL
LOSE ITS GRIP ON THE AREA NEXT WEEK WITH FAIR WEATHER AND MILDER
TEMPERATURES EXPECTED THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE SUNNY DAY WILL GIVE WAY TO INCREASE FROM NW TO SE THIS
EVENING. A BREEZY WSW WIND WILL CONTINUE AS THE UPPER LEVEL TROUGH
DRAGS A FRONT ACROSS LAKE ERIE EARLY THIS EVENING.
THE LATEST HRRR BRINGS A LINE OF SHOWERS BEGINNING THROUGH THE NW
AND SWEEPING THROUGH CENTRAL PA AROUND 00Z. THIS LINE WILL BE OUT
AHEAD OF AN AREA OF LOW PRESSURE ASSOCIATED WITH THE TROUGH THAT
WILL MOVE QUICKLY ALONG THE CANADIAN BORDER FROM NORTHWEST
ONTARIO THROUGH THE ST. LAWRENCE VALLEY WITH THE BEFORE MENTIONED
TRAILING COLD FRONT CROSSING THE AREA TONIGHT INTO EARLY TOMORROW.
MOISTURE/PW VALUES AHEAD OF THE COLD FRONT ARE FCST TO REMAIN AT
OR BELOW NORMAL WHICH SUGGESTS FRONTAL SHOWERS WILL BE ON THE
LIGHT SIDE. 12Z MODEL CONSENSUS PLACES THE HIGHEST AMTS /0.35 INCH
OR LESS/ OVER FAR NW PA IN CLOSE PROXIMITY TO LAKE ERIE...WHICH
SHOULD ENHANCE MSTR FLUX TO SOME DEGREE AND POSSIBLY INDUCE SOME
MARGINAL INSTABILITY. THE DOWNSLOPE MEAN WESTERLY FLOW AND LACK OF
LOW LEVEL MSTR WILL MAKE IT DIFFICULT FOR SHOWER ACTIVITY TO REACH
THE FAR SE ZONES. A PERSISTENT WEST WIND AND POST-FRONTAL CLOUDS
SHOULD KEEP MIN TEMPS A FEW DEGREES ABOVE MODEL BLEND.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
ALL MDL DATA TRACKS COLD FRONT EAST OF THE AREA BY 12Z FRIDAY.
ADVECTION OF LOW PWAT AIR MASS IN WAKE OF FRONT SHOULD ENSURE A
DRY FRIDAY OVER MOST OF CENTRAL PA. HOWEVER...A SECONDARY
SHORTWAVE/COLD FRONT WILL BE DIVING SE FROM THE GRT LKS LATE IN
THE DAY...LIKELY SPREADING SCT SHOWERS INTO THE NW COUNTIES BY
LATE AFTN. ANY QPF FROM THESE SHOWERS SHOULD BE LIGHT. GEFS MEAN
925TEMPS ARND 5C SHOULD TRANSLATE TO MAX TEMPS FROM THE L50S OVR
THE NW MTNS...TO THE M60S ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A COOL SHOWERY REGIME WILL PERSIST AT THE BEGINNING OF THE EXTENDED
FORECAST PERIOD AS DEEP CANADIAN UPPER TROF TRACKS FROM EASTERN
ONTARIO AND WESTERN QUEBEC FRIDAY NIGHT THROUGH QUEBEC AND
NORTHERN NEW ENGLAND SATURDAY NIGHT AND SUNDAY...AND EAST OF
NEWFOUNDLAND BY LATE MONDAY AND TUESDAY. THIS TROF WILL DELIVER
THE CHILLIEST AIR OF THE SEASON THUS FAR AND A WIDESPREAD CHC OF
FLURRIES AND LIGHT SNOW SHOWERS TO WESTERN AND NORTHERN SECTIONS
LATER SATURDAY...SATURDAY NIGHT AND SUNDAY. IN ADDITION...A LAKE
SUPERIOR/HURON CONNECTION SHOULD SUPPORT A BAND OF MORE SOMEWHAT
MORE SUBSTANTIAL LAKE EFFECT SNOW SHOWERS ACROSS THE NW MTNS. AS
EARLIER NOTED...BLYR AND GROUND TEMPS WILL LIKELY REMAIN TOO WARM
FOR ACCUMS UNTIL SATURDAY NIGHT. SUSPECT THERE WILL BE A DUSTING
OF SNOW ACROSS THE NORTHWEST MOUNTAINS SATURDAY NIGHT INTO SUNDAY.
LITTLE CHANGE SEEN IN OVERALL DETAILS TODAY AS COLD POOL CROSSES
THE STATE SUNDAY...FOLLOWED BY LARGE SCALE RIDGING AND A RETURN TO
NICE FALL WEATHER FOR MONDAY AND TUESDAY. MAIN FORECAST ISSUE IS
ON THE COLD FOR SUNDAY MORNING...WHICH IS LIKELY TO END THE
GROWING SEASON FOR THE REST OF CENTRAL PA...AND ON TIMING OF
ARRIVAL OF APPROACHING FRONT TOWARDS MIDWEEK OR BEYOND AS SFC HIGH
REMAINS LODGED ALONG AND JUST OFF THE MID ATLANTIC COAST BY
WED/THU. INTRODUCED SLGT/CHC SHOWERS ON WEDNESDAY
AFTERNOON...WHICH LINGERS THU AND FRI AS SLOW MOVING FRONT SAGS
ACROSS THE REGION.
ALTHOUGH MUCH OF THE AREA WILL LIKELY EXPERIENCE A FREEZE SAT NIGHT...
STILL EXPECT THE COLDEST TEMPS TO OCCUR SUN NIGHT...AS SFC HIGH
BUILDS INTO THE REGION. CLEAR SKIES AND A LGT WIND SHOULD ALLOW
TEMPS TO FALL BLW FREEZING OVR NEARLY THE ENTIRE CWA WITH
WIDESPREAD FROST LIKELY.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
ONLY MINOR CHANGES TO 21Z TAFS.
EARLIER DISCUSSION BELOW.
ALL TAF SITES ARE VFR AND SHOULD REMAIN SO WITH FAIR WEATHER
STRATO CU THROUGH THE REST OF THE DAYLIGHT HOURS. AS A COLD FRONT
APPROACHES EXPECT CHANCES FOR PRECIPITATION TO INCREASE THIS EVENING.
MVFR CIGS AND VSBYS AT BFD WILL BE POSSIBLE AFTER 00Z...WITH PRE
FRONTAL CONVECTION POSSIBLE IN THE MOIST UNSTABLE FLOW. THE MAIN
FRONT WILL MOVE SEWD ACROSS THE AIRSPACE BTWN 00-12Z FRI
ACCOMPANIED BY SCT SHOWERS. MVFR CIGS ARE LKLY AT AND BEHIND THE
FRONT AND SHOULD LAST THROUGH THE WEEKEND OVER THE WRN AIRSPACE IN
COLD NW FLOW PATTERN.
OUTLOOK...
SAT-SUN...MVFR CIGS/-SHRASN WRN TAFS. LOW VFR CIGS CNTRL/EAST.
WIND GUSTS 15-20KTS FROM 280-310.
MON-TUE...VFR. NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CERU/STEINBUGL
NEAR TERM...CERU/STEINBUGL
SHORT TERM...FITZGERALD/CERU
LONG TERM...DEVOIR
AVIATION...CERU/MARTIN/STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
307 PM EDT THU OCT 15 2015
.SYNOPSIS...
AN AMPLIFIED UPPER LEVEL TROUGH OVER EASTERN CANADA WILL DOMINATE
THE REGIONAL WEATHER PATTERN THROUGH THE WEEKEND WITH TEMPERATURES
AVERAGING BELOW NORMAL. A WEAK FRONT WILL MOVE THROUGH TOMORROW
AND FROST/FREEZE CONDITIONS THIS WEEKEND WILL LIKELY BRING AN END
TO THE GROWING SEASON. THE SEASONABLY COLD NORTHWEST FLOW WILL
LOSE ITS GRIP ON THE AREA NEXT WEEK WITH FAIR WEATHER AND MILDER
TEMPERATURES EXPECTED THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE SUNNY DAY WILL GIVE WAY TO INCREASE FROM NW TO SE THIS
EVENING. A BREEZY WSW WIND WILL CONTINUE AS THE UPPER LEVEL TROUGH
DRAGS A FRONT ACROSS LAKE ERIE EARLY THIS EVENING.
THE LATEST HRRR BRINGS A LINE OF SHOWERS BEGINNING THROUGH THE NW
AND SWEEPING THROUGH CENTRAL PA AROUND 00Z. THIS LINE WILL BE OUT
AHEAD OF AN AREA OF LOW PRESSURE ASSOCIATED WITH THE TROUGH THAT WILL
MOVE QUICKLY ALONG THE CANADIAN BORDER FROM NORTHWEST ONTARIO
THROUGH THE ST. LAWRENCE VALLEY WITH THE BEFORE MENTIONED TRAILING
COLD FRONT CROSSING THE AREA TONIGHT INTO EARLY TOMORROW.
MOISTURE/PW VALUES AHEAD OF THE COLD FRONT ARE FCST TO REMAIN AT
OR BELOW NORMAL WHICH SUGGESTS FRONTAL SHOWERS WILL BE ON THE
LIGHT SIDE. 12Z MODEL CONSENSUS PLACES THE HIGHEST AMTS /0.35
INCH OR LESS/ OVER FAR NW PA IN CLOSE PROXIMITY TO LAKE
ERIE...WHICH SHOULD ENHANCE MSTR FLUX TO SOME DEGREE AND POSSIBLY
INDUCE SOME MARGINAL INSTABILITY. THE DOWNSLOPE MEAN WESTERLY FLOW
AND LACK OF LOW LEVEL MSTR WILL MAKE IT DIFFICULT FOR SHOWER
ACTIVITY TO REACH THE FAR SE ZONES. A PERSISTENT WEST WIND AND
POST-FRONTAL CLOUDS SHOULD KEEP MIN TEMPS A FEW DEGREES ABOVE
MODEL BLEND.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
ALL MDL DATA TRACKS COLD FRONT EAST OF THE AREA BY 12Z FRIDAY.
ADVECTION OF LOW PWAT AIR MASS IN WAKE OF FRONT SHOULD ENSURE A
DRY FRIDAY OVER MOST OF CENTRAL PA. HOWEVER...A SECONDARY
SHORTWAVE/COLD FRONT WILL BE DIVING SE FROM THE GRT LKS LATE IN
THE DAY...LIKELY SPREADING SCT SHOWERS INTO THE NW COUNTIES BY
LATE AFTN. ANY QPF FROM THESE SHOWERS SHOULD BE LIGHT. GEFS MEAN
925TEMPS ARND 5C SHOULD TRANSLATE TO MAX TEMPS FROM THE L50S OVR
THE NW MTNS...TO THE M60S ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A COOL SHOWERY REGIME WILL PERSIST AT THE BEGINNING OF THE EXTENDED
FORECAST PERIOD AS DEEP CANADIAN UPPER TROF TRACKS FROM EASTERN
ONTARIO AND WESTERN QUEBEC FRIDAY NIGHT THROUGH QUEBEC AND
NORTHERN NEW ENGLAND SATURDAY NIGHT AND SUNDAY...AND EAST OF
NEWFOUNDLAND BY LATE MONDAY AND TUESDAY. THIS TROF WILL DELIVER
THE CHILLIEST AIR OF THE SEASON THUS FAR AND A WIDESPREAD CHC OF
FLURRIES AND LIGHT SNOW SHOWERS TO WESTERN AND NORTHERN SECTIONS
LATER SATURDAY...SATURDAY NIGHT AND SUNDAY. IN ADDITION...A LAKE
SUPERIOR/HURON CONNECTION SHOULD SUPPORT A BAND OF MORE SOMEWHAT
MORE SUBSTANTIAL LAKE EFFECT SNOW SHOWERS ACROSS THE NW MTNS. AS
EARLIER NOTED...BLYR AND GROUND TEMPS WILL LIKELY REMAIN TOO WARM
FOR ACCUMS UNTIL SATURDAY NIGHT. SUSPECT THERE WILL BE A DUSTING
OF SNOW ACROSS THE NORTHWEST MOUNTAINS SATURDAY NIGHT INTO SUNDAY.
LITTLE CHANGE SEEN IN OVERALL DETAILS TODAY AS COLD POOL CROSSES
THE STATE SUNDAY...FOLLOWED BY LARGE SCALE RIDGING AND A RETURN TO
NICE FALL WEATHER FOR MONDAY AND TUESDAY. MAIN FORECAST ISSUE IS
ON THE COLD FOR SUNDAY MORNING...WHICH IS LIKELY TO END THE
GROWING SEASON FOR THE REST OF CENTRAL PA...AND ON TIMING OF
ARRIVAL OF APPROACHING FRONT TOWARDS MIDWEEK OR BEYOND AS SFC HIGH
REMAINS LODGED ALONG AND JUST OFF THE MID ATLANTIC COAST BY
WED/THU. INTRODUCED SLGT/CHC SHOWERS ON WEDNESDAY
AFTERNOON...WHICH LINGERS THU AND FRI AS SLOW MOVING FRONT SAGS
ACROSS THE REGION.
ALTHOUGH MUCH OF THE AREA WILL LIKELY EXPERIENCE A FREEZE SAT NIGHT...
STILL EXPECT THE COLDEST TEMPS TO OCCUR SUN NIGHT...AS SFC HIGH
BUILDS INTO THE REGION. CLEAR SKIES AND A LGT WIND SHOULD ALLOW
TEMPS TO FALL BLW FREEZING OVR NEARLY THE ENTIRE CWA WITH
WIDESPREAD FROST LIKELY.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
ALL TAF SITES ARE VFR AND SHOULD REMAIN SO WITH FAIR WEATHER
STRATO CU THROUGH THE REST OF THE DAYLIGHT HOURS. AS A COLD FRONT
APPROACHES EXPECT CHANCES FOR PRECIPITATION TO INCREASE THIS EVENING.
MVFR CIGS AND VSBYS AT BFD WILL BE POSSIBLE AFTER 00Z...WITH PRE
FRONTAL CONVECTION POSSIBLE IN THE MOIST UNSTABLE FLOW. THE MAIN
FRONT WILL MOVE SEWD ACROSS THE AIRSPACE BTWN 00-12Z FRI
ACCOMPANIED BY SCT SHOWERS. MVFR CIGS ARE LKLY AT AND BEHIND THE
FRONT AND SHOULD LAST THROUGH THE WEEKEND OVER THE WRN AIRSPACE IN
COLD NW FLOW PATTERN.
OUTLOOK...
SAT-SUN...MVFR CIGS/-SHRASN WRN TAFS. LOW VFR CIGS CNTRL/EAST.
WIND GUSTS 15-20KTS FROM 280-310.
MON...VFR. NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CERU/STEINBUGL
NEAR TERM...CERU/STEINBUGL
SHORT TERM...FITZGERALD/CERU
LONG TERM...DEVOIR
AVIATION...CERU/STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
257 PM EDT THU OCT 15 2015
.SYNOPSIS...
AN AMPLIFIED UPPER LEVEL TROUGH OVER EASTERN CANADA WILL DOMINATE
THE REGIONAL WEATHER PATTERN THROUGH THE WEEKEND WITH TEMPERATURES
AVERAGING BELOW NORMAL. A WEAK FRONT WILL MOVE THROUGH TOMORROW
AND FROST/FREEZE CONDITIONS THIS WEEKEND WILL LIKELY BRING AN END
TO THE GROWING SEASON. THE SEASONABLY COLD NORTHWEST FLOW WILL
LOSE ITS GRIP ON THE AREA NEXT WEEK WITH FAIR WEATHER AND MILDER
TEMPERATURES EXPECTED THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SUNNY DAY WILL GIVE WAY TO INCREASE FROM NW TO SE THIS
EVENING. A BREEZY WSW WIND WILL CONTINUE AS THE UPPER LEVEL TROUGH
DRAGS A FRONT ACROSS LAKE ERIE EARLY THIS EVENING.
THE LATEST HRRR BRINGS A LINE OF SHOWERS BEGINNING THROUGH THE NW
AND SWEEPING THROUGH CENTRAL PA AROUND 00Z. THIS LINE WILL BE OUT
AHEAD OF AN AREA OF LOW PRESSURE ASSOCIATED WITH THE TROUGH THAT WILL
MOVE QUICKLY ALONG THE CANADIAN BORDER FROM NORTHWEST ONTARIO
THROUGH THE ST. LAWRENCE VALLEY WITH THE BEFORE MENTIONED TRAILING
COLD FRONT CROSSING THE AREA TONIGHT INTO EARLY TOMORROW.
MOISTURE/PW VALUES AHEAD OF THE COLD FRONT ARE FCST TO REMAIN AT
OR BELOW NORMAL WHICH SUGGESTS FRONTAL SHOWERS WILL BE ON THE
LIGHT SIDE. 12Z MODEL CONSENSUS PLACES THE HIGHEST AMTS /0.35
INCH OR LESS/ OVER FAR NW PA IN CLOSE PROXIMITY TO LAKE
ERIE...WHICH SHOULD ENHANCE MSTR FLUX TO SOME DEGREE AND POSSIBLY
INDUCE SOME MARGINAL INSTABILITY. THE DOWNSLOPE MEAN WESTERLY FLOW
AND LACK OF LOW LEVEL MSTR WILL MAKE IT DIFFICULT FOR SHOWER
ACTIVITY TO REACH THE FAR SE ZONES. A PERSISTENT WEST WIND AND
POST-FRONTAL CLOUDS SHOULD KEEP MIN TEMPS A FEW DEGREES ABOVE
MODEL BLEND.
&&
.SHORT TERM /FRIDAY/...
ALL MDL DATA TRACKS COLD FRONT EAST OF THE AREA BY 12Z FRIDAY.
ADVECTION OF LOW PWAT AIR MASS IN WAKE OF FRONT SHOULD ENSURE A
DRY FRIDAY OVER MOST OF CENTRAL PA. HOWEVER...A SECONDARY
SHORTWAVE/COLD FRONT WILL BE DIVING SE FROM THE GRT LKS LATE IN
THE DAY...LIKELY SPREADING SCT SHOWERS INTO THE NW COUNTIES BY
LATE AFTN. ANY QPF FROM THESE SHOWERS SHOULD BE LIGHT. GEFS MEAN
925TEMPS ARND 5C SHOULD TRANSLATE TO MAX TEMPS FROM THE L50S OVR
THE NW MTNS...TO THE M60S ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AFOREMENTIONED SECONDARY COLD FRONT WILL PUSH THRU CENTRAL PA FRI
EVENING...USHERING IN THE CHILLIEST AIR MASS SO FAR THIS SEASON.
BEST LG SCALE FORCING AND ASSOC WITH SHORTWAVE WILL SKIRT THE NW
MTNS BTWN 00Z-06Z SAT...THUS THE HIGHEST POPS IN THE 80-90PCT
RANGE ARE PLACED UP THERE WITH A MARKEDLY LOWER CHC OF MEASURABLE
PRECIP FURTHER SE. MDL SOUNDINGS INDICATE SCT LAKE EFFECT SNOW
SHOWERS/FLURRIES ARE LIKELY ACROSS THE NW MTNS LATE FRIDAY NIGHT.
HOWEVER...FALLING INVERSION HGT AND DRY AIR MASS SHOULD RESULT IN
LIGHT PRECIP AMTS AND MARGINAL BLYR TEMPS/WARM GROUND WILL LIKELY
PRECLUDE ANY ACCUMS.
THE LARGE UPPER LEVEL TROUGH WILL SWING EASTWARD THROUGH THE
WEEKEND AND REINFORCING SHORTWAVES SHOULD HELP TO DEEPEN THE COLD
AIR WITH ANOMALOUS DEPARTURES REACHING -2.5SD BELOW THE MEAN OR
-5C TO -8C AT 850MB. DRYNESS OF ARRIVING AIR MASS /WITH NEG PWAT
ANOMALIES OF 1-2SD/ WILL LIMIT PRECIP TO SPRINKLES/FLURRIES FOR
MUCH OF CENTRAL PA. HOWEVER...LK HURON CONNECTION SHOULD SUPPORT A
BAND OF MORE SOMEWHAT MORE SUBSTANTIAL LAKE EFFECT SNOW SHOWERS
ACROSS THE NW MTNS. BLYR AND GROUND TEMPS WILL LIKELY REMAIN TOO
WARM FOR ACCUMS DURING SAT. HOWEVER...SUSPECT PORTIONS OF THE NW
MTNS WILL SEE A LIGHT ACCUM SAT NIGHT.
POOL OF COLDEST AIR ALOFT PASSES OVER THE STATE SUNDAY...LIKELY
RESULTING IN COVERAGE OF SHOWERS PEAKING SUNDAY AFTN DURING THE HOURS
OF MAX HEATING/INSTABILITY. MDL SOUNDINGS INDICATE PTYPE WILL BE
SHSN OVR THE MTNS AND SHRA ACROSS THE SUSQ VALLEY. NO ADDITIONAL
SNOW ACCUMS EXPECTED SUN AFTN OVR THE NW MTNS...AS TEMPS RISE TO
NEAR 40F OVR THE ALLEGHENIES. ALTHOUGH MUCH OF THE AREA WILL
LIKELY EXPERIENCE A FREEZE SAT NIGHT...EXPECT THE COLDEST TEMPS TO
OCCUR SUN NIGHT...AS SFC HIGH BUILDS INTO THE REGION. CLEAR SKIES
AND A LGT WIND SHOULD ALLOW TEMPS TO FALL BLW FREEZING OVR NEARLY
THE ENTIRE CWA WITH WIDESPREAD FROST LIKELY.
ALL MED RANGE GUIDANCE INDICATING FAIR WX AND MODERATING TEMPS
NEXT WEEK...AS UPPER TROUGH QUICKLY LIFTS OUT. SFC HIGH IS PROGGED
TO VERY SLOWLY PUSH OFF THE MID ATL COAST WITH RETURN SW FLOW
RETURNING TEMPS TO ABV NORMAL READINGS BY MIDWEEK.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
ALL TAF SITES ARE VFR AND SHOULD REMAIN SO WITH FAIR WEATHER
STRATO CU THROUGH THE REST OF THE DAYLIGHT HOURS. AS A COLD FRONT
APPROACHES EXPECT CHANCES FOR PRECIPITATION TO INCREASE THIS EVENING.
MVFR CIGS AND VSBYS AT BFD WILL BE POSSIBLE AFTER 00Z...WITH PRE
FRONTAL CONVECTION POSSIBLE IN THE MOIST UNSTABLE FLOW. THE MAIN
FRONT WILL MOVE SEWD ACROSS THE AIRSPACE BTWN 00-12Z FRI
ACCOMPANIED BY SCT SHOWERS. MVFR CIGS ARE LKLY AT AND BEHIND THE
FRONT AND SHOULD LAST THROUGH THE WEEKEND OVER THE WRN AIRSPACE IN
COLD NW FLOW PATTERN.
OUTLOOK...
SAT-SUN...MVFR CIGS/-SHRASN WRN TAFS. LOW VFR CIGS CNTRL/EAST.
WIND GUSTS 15-20KTS FROM 280-310.
MON...VFR. NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CERU/STEINBUGL
NEAR TERM...CERU/STEINBUGL
SHORT TERM...FITZGERALD/CERU
LONG TERM...FITZGERALD
AVIATION...CERU/STEINBUGL
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
116 AM CDT THU OCT 15 2015
.AVIATION...VFR CONDITIONS PREVAIL AS OF 06Z BUT ADDITIONAL
MOISTURE RETURN DUE TO SOUTHEAST WINDS WILL ALLOW FOR SOME MVFR
STRATUS DECKS TO DEVELOP KDRT 12-15Z THURSDAY MORNING. THIS LOWER
DECK WILL ALSO ENCROACH ON KSSF/KSAT 10-15Z AS WELL BUT MOISTURE
MAY BE JUST LIMITED ENOUGH NOT TO GO BKN. HAVE TRENDED CIG
FORECAST TOWARDS THE NAM BUFR SOUNDING AND HRRR OUTPUT OF A SCT020
DECK FOR KSAT/KSSF. SOME PATCHY GROUND FOG WILL ALLOW BE A
POSSIBILITY FOR SOUTHEAST COUNTIES BUT SHOULD NOT EFFECT CENTRAL
TAF SITES. AN ISSUE FOR KAUS WILL BE LIGHT SMOKE DURING THE
MORNING HOURS FROM THE WILDFIRE BURNING NEAR BASTROP. HAVE PLACED
SMOKE DIRECTLY IN THE TAF WORDING GIVEN PROJECTED SMOKE PLUME
TRAJECTORIES NEAR THE AIRPORT. EXPECT VFR TO PREVAIL BY LATE
MORNING THURSDAY WITH SKC CONDITIONS OUTSIDE OF SMOKE ISSUES NEAR
AND EAST OF KAUS. SURFACE WINDS WILL BE NEAR 5 KT OVERNIGHT FROM
THE SOUTHEAST AND THEN PICK UP TO 10-15 KT THIS AFTN. AN
OCCASIONAL UPPER TEEN GUST WILL BE POSSIBLE FROM THE SOUTHEAST AS
BETTER MIXING OCCURS THIS AFTN.
&&
PREV DISCUSSION... /ISSUED 316 PM CDT WED OCT 14 2015/
SHORT TERM (TODAY THROUGH THURSDAY)...
DRY WEATHER CONDITIONS ARE IN PLACE AND EXPECTED TO CONTINUE
THROUGH THURSDAY EVENING. LOW LEVEL MOISTURE IS FORECAST TO
INCREASE LATE TONIGHT INTO THURSDAY AS SOUTHERLY FLOW PREVAILS.
THE SPREADING OF ANY FIRES THAT DO OCCUR OR ARE ONGOING PRESENT A
CONCERN THROUGH EARLY THIS EVENING AS RELATIVE HUMIDITIES ARE IN
THE LOWER TEENS WITH VERY DRY AIRMASS IN PLACE. WINDS WILL
CONTINUE FROM THE SOUTHEAST AROUND 6 TO 8 MPH WITH GUSTS UP TO
15 MPH THROUGH ABOUT 7 PM.
MANY COUNTIES ACROSS THE REGION HAVE ENACTED BURN BANS AND WHILE
THESE SHOULD BE HEEDED AT ALL TIMES...IT WILL BE PARTICULARLY
IMPORTANT TO NOT START ANY FIRES FOR THE REST OF TODAY AND
THURSDAY AS THEY COULD HAVE THE POTENTIAL TO SPREAD QUICKLY AND
EFFICIENTLY. IF YOU HAPPEN TO NOTICE ANY SMALL GRASS FIRES OR
SMOKE...PLEASE INFORM YOUR LOCAL FIRE DEPARTMENT OR LOCAL LAW
ENFORCEMENT. SEE FIRE WEATHER FOR MORE INFORMATION.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
DRY WEATHER CONDITIONS CONTINUE THROUGH THE UPCOMING WEEKEND. A
WEAK FRONTAL BOUNDARY IS EXPECTED TO STALL TO THE NORTH OF THE
HILL COUNTRY ON FRIDAY. ANOTHER AND MORE SIGNIFICANT COLD FRONT IS
FORECAST TO PUSH ACROSS THE AREA ON WEDNESDAY WITH THE HELP OF AN
UPPER LEVEL DISTURBANCE THAT IS FORECAST TO PUSH EAST FROM THE
FOUR CORNERS REGION EARLY NEXT WEEK. THE GFS SOLUTION IS JUST A
BIT SLOWER THAN ECM...BUT OVERALL...FAIR TO GOOD AGREEMENT IS ON
PLACE FOR THE POTENTIAL FOR SCATTERED RAIN CHANCES.
FIRE WEATHER...
THE FIRE WEATHER CONCERN CONTINUES ACROSS THE HILL COUNTRY FOR
THURSDAY AS RELATIVE HUMIDITIES ARE FORECAST TO DECREASE TO THE
UPPER TEENS AND LOWER 20S DURING THE AFTERNOON. SOUTHERLY WINDS
ARE FORECAST TO INCREASE FROM THE MID MORNING HOURS ON THURSDAY
THROUGH THE AFTERNOON AND RANGE FROM 8 TO 11 MPH WITH GUSTS UP TO
15 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 93 62 91 62 87 / 0 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 92 58 90 58 87 / 0 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 93 61 91 61 89 / 0 0 0 0 0
BURNET MUNI AIRPORT 91 60 88 60 85 / 0 0 0 0 0
DEL RIO INTL AIRPORT 90 68 85 64 85 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 92 59 90 59 86 / 0 0 0 0 0
HONDO MUNI AIRPORT 92 62 89 61 88 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 92 61 91 61 87 / 0 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 92 59 91 60 87 / 0 0 0 0 0
SAN ANTONIO INTL AIRPORT 91 64 90 63 88 / 0 0 0 0 0
STINSON MUNI AIRPORT 92 64 90 63 90 / 0 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...ALLEN
SYNOPTIC/GRIDS...TB3
AREA FORECAST DISCUSSION
NWS SEATTLE WA
900 PM PDT WED OCT 14 2015...CORRECTED
.SYNOPSIS...HIGH PRESSURE ALOFT AND LOW LEVEL OFFSHORE FLOW WILL
PREVAIL OVER WESTERN WASHINGTON THROUGH THURSDAY EVENING RESULTING IN
A WARMING AND DRYING AIR MASS. WINDS WILL BECOME GUSTY ALONG THE
CASCADE FOOTHILLS NEAR THE ENTRANCES TO THE PASSES. THE NEXT RAIN
PRODUCING COLD FRONT WILL ARRIVE AT THE COAST ON FRIDAY NIGHT AND
SPREAD RAIN INLAND ON SATURDAY. A LULL IN RAINFALL IS EXPECTED
ON SATURDAY NIGHT AND SUNDAY MORNING WITH THE NEXT MORE ORGANIZED
AREA OF RAIN SPREADING ACROSS WESTERN WASHINGTON AROUND SUNDAY NIGHT.
&&
.SHORT TERM...AN UPPER LEVEL RIDGE AXIS JUST OFF THE PAC NW COAST
WILL AMPLIFY AND SHIFT EASTWARD...TRAVERSING THE REGION THURSDAY. AN
UPPER LEVEL TROUGH WILL DIG SWD AND ELONGATE OFFSHORE FURTHER
WEST...SETTING UP DEEP SLY FLOW ALOFT OVER THE AREA THROUGH
FRIDAY. THE COMBINATION OF SLY FLOW ALOFT...INCREASING LOW LEVEL
OFFSHORE GRADIENTS...AND RISING HEIGHTS SHOULD RESULT IN MUCH WARMER
TEMPERATURES ACROSS WRN WA THURSDAY AND FRIDAY. FORECAST HIGHS ARE
AROUND OR JUST ABOVE 70 ACROSS MUCH OF PUGET SOUND WITH A DRY
MOISTURE PROFILE IN THE LOWER TO MID LEVEL WITH EASTERLY DOWNSLOPE
AFFECTS. HIGH CLOUDS WILL BRUSH THE AREA AT TIMES BUT SHOULD NOT
HINDER HIGH TEMPERATURES ALL THAT MUCH. FOG WILL BE MORE LIMITED
THAN PAST MORNING WITH THE DRIER BREEZY EAST FLOW AND HIGHER
CLOUDS...WITH JUST THE MOST SHELTERED SPOTS LIKE AROUND OLYMPIA AND
THE SW INTERIOR SEEING SOME FOG EARLY THURSDAY MORNING.
LOW LEVEL EASTERLY GRADIENTS COULD BECOME STRONG FOR A PERIOD
THURSDAY. THE 18Z NAM GIVES A KSEA-KEAT GRADIENT NEAR +8 MB LATE
THURSDAY MORNING AND THE WRFGFS SHOWS SOME ISOLATED SPOTS OF 20-30
MPH WITH GUSTS 40-45 MPH NEAR THE CASCADE GAPS. STRONGEST WINDS
MAY STAY JUST INSIDE THE CASCADE ZONE BUT THE FOOTHILL ZONES COULD
SEE LOCALLY WINDY CONDITIONS THURSDAY NEAR THE GAPS...ESPECIALLY MID
MORNING TO EARLY AFTERNOON. WILL HOLD OFF ON A WIND ADVISORY
GIVEN HOW LOCALIZED AND BORDERLINE THESE WINDS WILL BE. THE 00Z RUN
OF THE WRFGFS...AND HRRR SHOULD GIVE A BETTER CLUE SO WILL LET THE
NEXT SHIFT DECIDE ON ANY CHANGES.
AFTER A COUPLE OF MILD DAYS...THE APPROACHING TROUGH WILL BECOME
NEGATIVE TILT AND PARTIALLY SPLIT. THE CURRENT 18Z GFS RUN GIVES
ABOUT A QUARTER INCH OF RAIN TO MUCH OF THE AREA AS THE FRONT PUSHES
THROUGH SATURDAY. HOWEVER...I SUSPECT MODELS WILL TREND TOWARD A
WEAKER SYSTEM AND LOWER QPF GIVE THE HIGH AMPLITUDE SPLIT AND STRENGTH
OF THE RIDGE. MERCER
.CLIMATE...THE PATTERN THROUGH FRIDAY WILL PRODUCE SOME OF OUR WARMER
TEMPERATURES IN OCTOBER. HISTORICALLY...THE AVERAGE DATE FOR THE LAST
70+ DAY DEGREE DAY OF THE YEAR AT SEA-TAC IS OCT 8. THE FORECAST
OF 70 AND 71 AT SEA-TAC TOMORROW AND FRIDAY WOULD BEAT THE AVERAGE BY
ABOUT A WEEK.
.LONG TERM...FROM PREVIOUS DISCUSSION...ONCE THE UPPER TROUGH AXIS
CROSSES WRN WA LATE SAT...A BRIEF SHORTWAVE RIDGE AND A LULL IN
PRECIP IS EXPECTED LATE SAT NGT AND SUNDAY MORNING.
BOTH THE GFS AND ECMWF AGREE IN QUICKLY MOVING A SHORTWAVE
EASTWARD ACROSS WRN WA IN ZONAL FLOW FROM SUN AFTN THROUGH SUN
NGT. HOWEVER...THE ECMWF BRINGS HEAVIER AND MORE WIDESPREAD RAIN
WITH THIS FEATURE ON SUN NGT...WHILE THE GFS TRIES TO BREAK UP THE
AREA OF RAIN AS IT MOVES INLAND FROM THE COAST.
HIGHER HEIGHTS AND FLAT UPPER RIDGING WILL FOLLOW ON MON. THE AIR
MASS WILL REMAIN MOIST...BUT LARGE-SCALE LIFT TAKES A BREAK...SO A
RELATIVE LULL IN PRECIP IS EXPECTED LATE MON INTO TUE.
MODEL CONSISTENCY FALLS APART AFTER TUE...MAINLY IN TERMS OF
TIMING. THE ECMWF HANGS ON TO FLAT RIDGING NEXT WED WITH LESS
PRECIP. MEANWHILE THE GFS BRINGS IN THE NEXT TROUGH...WITH MORE
PRECIP AND SNOW LEVELS LOWERING OVER THE HIGHER NON-VOLCANIC
PEAKS. HANER
&&
.AVIATION...STABLE WLY FLOW ALOFT WILL BECOME SWLY THU AFTERNOON.
EXCEPT FOR OCCASIONAL CIRRUS...AND SHALLOW MORNING FOG IN THE
INTERIOR FROM ABOUT TACOMA SOUTHWARD...THE AIR MASS WILL BE DRY
THROUGH THU.
A 1030 MB HIGH CENTERED OVER CENTRAL BRITISH COLUMBIA WILL WEAKEN
AND MOVE EAST OF THE ROCKIES ON THURSDAY. IN RESPONSE TO THE HIGH TO
THE NORTHEAST...OFFSHORE FLOW WILL INCREASE LATE TONIGHT AND
THURSDAY MORNING...THEN WILL WEAKEN STARTING THURSDAY AFTERNOON.
THE OFFSHORE FLOW WILL KEEP THE LOWER AND MID LEVELS OF THE
ATMOSPHERE QUITE DRY...EXCEPT IN THE INTERIOR FROM ABOUT TACOMA
SOUTHWARD DURING THE LATE NIGHT AND MORNING HOURS WHERE AREAS OF
SHALLOW FOG CAN BE EXPECTED. FOG THAT FORMS WILL DISSIPATE BY 18Z.
EXPECT A 12 HOUR PERIOD OF EAST WINDS 20-30 KT WITH A SOME GUSTS TO
40 KT NEAR THE CASCADES...ESPECIALLY NEAR THE ENTRANCE TO SNOQUALMIE
AND STAMPEDE PASSES...FROM ABOUT 07Z-19Z THURSDAY. ALBRECHT
KSEA...PERIODS OF BKN250 WITH GOOD VISIBILITY THROUGH THU. WIND NE 7-
10 KT WILL TURN NLY AFTER 21Z THU. ALBRECHT.
&&
.MARINE...A 1030 MB HIGH OVER CENTRAL BRITISH COLUMBIA WILL SHIFT TO
THE EAST AND WEAKEN THURSDAY AFTERNOON. THIS HIGH WILL GIVE A PERIOD
OF MODERATE TO LOCALLY STRONG OFFSHORE FLOW LATE TONIGHT INTO MID
AFTERNOON THURSDAY. THE FLOW WILL TURN MORE SELY AND WEAKEN LATE
THURSDAY AFTERNOON. A SMALL CRAFT ADVISORY IS UP THROUGH 3 PM
THURSDAY FOR THE WEST ENTRANCE TO THE STRAIT OF JUAN DE FUCA AND FOR
THE COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT TO 10 NM.
A FRONT WILL APPROACH THE COASTAL WATERS ON FRIDAY THEN MOVE THROUGH
THE COASTAL AND INLAND WATERS ON SATURDAY. AT THIS TIME EXPECT SMALL
CRAFT ADVISORY WINDS TO BE LIMITED TO THE COASTAL WATERS WITH THIS
FRONT.
ANOTHER FRONT WILL MOVE THROUGH THE WATERS LATE SUNDAY OR SUNDAY
NIGHT. THIS FRONT WILL LIKELY BE ACCOMPANIED BY SMALL CRAFT ADVISORY
SOUTH TO SOUTHWEST WINDS OVER THE COASTAL WATERS...THE ENTRANCES TO
THE STRAIT OF JUAN DE FUCA...AND THE NORTHERN INLAND WATERS. ALBRECHT
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 3 PM PDT THURSDAY FOR COASTAL WATERS
FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-WEST ENTRANCE
U.S. WATERS STRAIT OF JUAN DE FUCA.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS SEATTLE WA
900 PM PDT WED OCT 14 2015
.SYNOPSIS...HIGH PRESSURE ALOFT AND LOW LEVEL OFFSHORE FLOW WILL
PREVAIL OVER WESTERN WASHINGTON THROUGH THURSDAY EVENING RESULTING IN
A WARMING AND DRYING AIR MASS. WINDS WILL BECOME GUSTY ALONG THE
CASCADE FOOTHILLS NEAR THE ENTRANCES TO THE PASSES. THE NEXT RAIN
PRODUCING COLD FRONT WILL ARRIVE AT THE COAST ON FRIDAY NIGHT AND
SPREAD RAIN INLAND ON SATURDAY. A LULL IN RAINFALL IS EXPECTED
ON SATURDAY NIGHT AND SUNDAY MORNING WITH THE NEXT MORE ORGANIZED
AREA OF RAIN SPREADING ACROSS WESTERN WASHINGTON AROUND SUNDAY NIGHT.
&&
.SHORT TERM...AN UPPER LEVEL RIDGE AXIS JUST OFF THE PAC NW COAST
WILL AMPLIFY AND SHIFT EASTWARD...TRAVERSING THE REGION SATURDAY. AN
UPPER LEVEL TROUGH WILL DIG SWD AND ELONGATE OFFSHORE FURTHER
WEST...SETTING UP DEEP SLY FLOW ALOFT OVER THE AREA THROUGH
FRIDAY. THE COMBINATION OF SLY FLOW ALOFT...INCREASING LOW LEVEL
OFFSHORE GRADIENTS...AND RISING HEIGHTS SHOULD RESULT IN MUCH WARMER
TEMPERATURES ACROSS WRN WA THURSDAY AND FRIDAY. FORECAST HIGHS ARE
AROUND OR JUST ABOVE 70 ACROSS MUCH OF PUGET SOUND WITH A DRY
MOISTURE PROFILE IN THE LOWER TO MID LEVEL WITH EASTERLY DOWNSLOPE
AFFECTS. HIGH CLOUDS WILL BRUSH THE AREA AT TIMES BUT SHOULD NOT
HINDER HIGH TEMPERATURES ALL THAT MUCH. FOG WILL BE MORE LIMITED
THAN PAST MORNING WITH THE DRIER BREEZY EAST FLOW AND HIGHER
CLOUDS...WITH JUST THE MOST SHELTERED SPOTS LIKE AROUND OLYMPIA AND
THE SW INTERIOR SEEING SOME FOG EARLY THURSDAY MORNING.
LOW LEVEL EASTERLY GRADIENTS COULD BECOME STRONG FOR A PERIOD
THURSDAY. THE 18Z NAM GIVES A KSEA-KEAT GRADIENT NEAR +8 MB LATE
THURSDAY MORNING AND THE WRFGFS SHOWS SOME ISOLATED SPOTS OF 20-30
MPH WITH GUSTS 40-45 MPH NEAR THE CASCADE GAPS. STRONGEST WINDS
MAY STAY JUST INSIDE THE CASCADE ZONE BUT THE FOOTHILL ZONES COULD
SEE LOCALLY WINDY CONDITIONS THURSDAY NEAR THE GAPS...ESPECIALLY MID
MORNING TO EARLY AFTERNOON. WILL HOLD OFF ON A WIND ADVISORY
GIVEN HOW LOCALIZED AND BORDERLINE THESE WINDS WILL BE. THE 00Z RUN
OF THE WRFGFS...AND HRRR SHOULD GIVE A BETTER CLUE SO WILL LET THE
NEXT SHIFT DECIDE ON ANY CHANGES.
AFTER A COUPLE OF MILD DAYS...THE APPROACHING TROUGH WILL BECOME
NEGATIVE TILT AND PARTIALLY SPLIT. THE CURRENT 18Z GFS RUN GIVES
ABOUT A QUARTER INCH OF RAIN TO MUCH OF THE AREA AS THE FRONT PUSHES
THROUGH SATURDAY. HOWEVER...I SUSPECT MODELS WILL TREND TOWARD A
WEAKER SYSTEM AND LOWER QPF GIVE THE HIGH AMPLITUDE SPLIT AND STRENGTH
OF THE RIDGE. MERCER
.CLIMATE...THE PATTERN THROUGH FRIDAY WILL PRODUCE SOME OF OUR WARMER
TEMPERATURES IN OCTOBER. HISTORICALLY...THE AVERAGE DATE FOR THE LAST
70+ DAY DEGREE DAY OF THE YEAR AT SEA-TAC IS OCT 8. THE FORECAST
OF 70 AND 71 AT SEA-TAC TOMORROW AND FRIDAY WOULD BEAT THE AVERAGE BY
ABOUT A WEEK.
.LONG TERM...FROM PREVIOUS DISCUSSION...ONCE THE UPPER TROUGH AXIS
CROSSES WRN WA LATE SAT...A BRIEF SHORTWAVE RIDGE AND A LULL IN
PRECIP IS EXPECTED LATE SAT NGT AND SUNDAY MORNING.
BOTH THE GFS AND ECMWF AGREE IN QUICKLY MOVING A SHORTWAVE
EASTWARD ACROSS WRN WA IN ZONAL FLOW FROM SUN AFTN THROUGH SUN
NGT. HOWEVER...THE ECMWF BRINGS HEAVIER AND MORE WIDESPREAD RAIN
WITH THIS FEATURE ON SUN NGT...WHILE THE GFS TRIES TO BREAK UP THE
AREA OF RAIN AS IT MOVES INLAND FROM THE COAST.
HIGHER HEIGHTS AND FLAT UPPER RIDGING WILL FOLLOW ON MON. THE AIR
MASS WILL REMAIN MOIST...BUT LARGE-SCALE LIFT TAKES A BREAK...SO A
RELATIVE LULL IN PRECIP IS EXPECTED LATE MON INTO TUE.
MODEL CONSISTENCY FALLS APART AFTER TUE...MAINLY IN TERMS OF
TIMING. THE ECMWF HANGS ON TO FLAT RIDGING NEXT WED WITH LESS
PRECIP. MEANWHILE THE GFS BRINGS IN THE NEXT TROUGH...WITH MORE
PRECIP AND SNOW LEVELS LOWERING OVER THE HIGHER NON-VOLCANIC
PEAKS. HANER
&&
.AVIATION...STABLE WLY FLOW ALOFT WILL BECOME SWLY THU AFTERNOON.
EXCEPT FOR OCCASIONAL CIRRUS...AND SHALLOW MORNING FOG IN THE
INTERIOR FROM ABOUT TACOMA SOUTHWARD...THE AIR MASS WILL BE DRY
THROUGH THU.
A 1030 MB HIGH CENTERED OVER CENTRAL BRITISH COLUMBIA WILL WEAKEN
AND MOVE EAST OF THE ROCKIES ON THURSDAY. IN RESPONSE TO THE HIGH TO
THE NORTHEAST...OFFSHORE FLOW WILL INCREASE LATE TONIGHT AND
THURSDAY MORNING...THEN WILL WEAKEN STARTING THURSDAY AFTERNOON.
THE OFFSHORE FLOW WILL KEEP THE LOWER AND MID LEVELS OF THE
ATMOSPHERE QUITE DRY...EXCEPT IN THE INTERIOR FROM ABOUT TACOMA
SOUTHWARD DURING THE LATE NIGHT AND MORNING HOURS WHERE AREAS OF
SHALLOW FOG CAN BE EXPECTED. FOG THAT FORMS WILL DISSIPATE BY 18Z.
EXPECT A 12 HOUR PERIOD OF EAST WINDS 20-30 KT WITH A SOME GUSTS TO
40 KT NEAR THE CASCADES...ESPECIALLY NEAR THE ENTRANCE TO SNOQUALMIE
AND STAMPEDE PASSES...FROM ABOUT 07Z-19Z THURSDAY. ALBRECHT
KSEA...PERIODS OF BKN250 WITH GOOD VISIBILITY THROUGH THU. WIND NE 7-
10 KT WILL TURN NLY AFTER 21Z THU. ALBRECHT.
&&
.MARINE...A 1030 MB HIGH OVER CENTRAL BRITISH COLUMBIA WILL SHIFT TO
THE EAST AND WEAKEN THURSDAY AFTERNOON. THIS HIGH WILL GIVE A PERIOD
OF MODERATE TO LOCALLY STRONG OFFSHORE FLOW LATE TONIGHT INTO MID
AFTERNOON THURSDAY. THE FLOW WILL TURN MORE SELY AND WEAKEN LATE
THURSDAY AFTERNOON. A SMALL CRAFT ADVISORY IS UP THROUGH 3 PM
THURSDAY FOR THE WEST ENTRANCE TO THE STRAIT OF JUAN DE FUCA AND FOR
THE COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT TO 10 NM.
A FRONT WILL APPROACH THE COASTAL WATERS ON FRIDAY THEN MOVE THROUGH
THE COASTAL AND INLAND WATERS ON SATURDAY. AT THIS TIME EXPECT SMALL
CRAFT ADVISORY WINDS TO BE LIMITED TO THE COASTAL WATERS WITH THIS
FRONT.
ANOTHER FRONT WILL MOVE THROUGH THE WATERS LATE SUNDAY OR SUNDAY
NIGHT. THIS FRONT WILL LIKELY BE ACCOMPANIED BY SMALL CRAFT ADVISORY
SOUTH TO SOUTHWEST WINDS OVER THE COASTAL WATERS...THE ENTRANCES TO
THE STRAIT OF JUAN DE FUCA...AND THE NORTHERN INLAND WATERS. ALBRECHT
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 3 PM PDT THURSDAY FOR COASTAL WATERS
FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-WEST ENTRANCE
U.S. WATERS STRAIT OF JUAN DE FUCA.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1037 PM CDT FRI OCT 16 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 229 PM CDT FRI OCT 16 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM CENTRAL CANADA TO THE WESTERN GULF OF
MEXICO EARLY THIS AFTERNOON. EAST OF THE RIDGE AXIS...COLD CYCLONIC
FLOW CONTINUES OVER THE WESTERN GREAT LAKES REGION. RECEIVED
SEVERAL REPORTS OF FLURRIES OVER CENTRAL AND NORTH-CENTRAL WI EARLY
THIS MORNING...BUT THOSE REPORTS DRIED UP BY LATE IN THE MORNING.
SCATTERED TO BROKEN CLOUDS ARE PREVAILING ACROSS MUCH OF THE REGION
EARLY THIS AFTERNOON...BUT THESE CLOUDS ARE GRADUALLY MIXING OUT
OVER CENTRAL WI. THIS TREND SHOULD SPREAD EAST FOR THE REST OF THE
AFTERNOON AWAY FROM THE LAKE EFFECT BELTS. LOOKING UPSTREAM...A
FAIRLY SOLID CLOUD MASS IS DIVING SOUTHEAST OVER THE LAKE
WINNIPEG/NORTHERN MINNESOTA REGION. CLOUDS AND TEMPS ARE THE MAIN
FORECAST CONCERNS IN THE SHORT TERM.
TONIGHT...CANADIAN HIGH PRESSURE WILL BE SHIFTING EAST ACROSS THE
NORTHERN MISSISSIPPI VALLEY AND INTO THE WESTERN GREAT LAKES. LOW
LEVEL WINDS WILL REMAIN OUT OF THE NORTHWEST...AND BRING IN
SCATTERED CLOUD COVER OFF LAKE SUPERIOR...WITH AREAS OF BROKEN
CLOUDS AT TIMES...INTO NORTH-CENTRAL AND PARTS OF NE WISCONSIN.
SCATTERED FLURRIES WILL LIKELY CONTINUE OVER THE NORTHERN HALF OF
VILAS CO. THEN MODELS PROJECT THE AREA OF OVERCAST OVER LAKE
WINNIPEG WILL ARRIVE AFTER MIDNIGHT INTO N-C WI. PERHAPS WILL SEE A
SLIGHT UPTICK IN ANY LAKE EFFECT SNOW SHOWERS IN THE SNOW BELTS.
ELSEWHERE...AC DECK OVER MINNESOTA LOOKS TO SLIDE SOUTH OF THE
REGION. SO SHOULD SEE CLEARING THIS EVENING OVER CENTRAL AND EAST-
CENTRAL WI AS DIURNAL HEATING IS LOST. LOW LEVEL WINDS SHOULD
REMAIN IN THE 15-20 KT RANGE...WHICH SHOULD BE GOOD FOR THE COLD
SPOTS TO BECOME CALM FOR PERIODS. REMAINED CONSERVATIVE WITH LOWS
HOWEVER...DUE TO UNCERTAINTY WITH CLOUD COVER. A HARD FREEZE/FROST
STILL LOOKS GOOD FOR THE FOX VALLEY/LAKESHORE.
SATURDAY...HIGH PRESSURE WILL SHIFT TOWARDS THE CENTRAL MISSISSIPPI
VALLEY. WINDS WILL START OUT FROM THE NORTHWEST..THEN BACK MORE
WESTERLY THROUGH THE DAY. AS A RESULT...ANY LAKE CLOUDS AND
FLURRIES ACROSS THE NORTH SHOULD RETREAT TOWARDS THE UPPER PENINSULA
THROUGH THE DAY. SHOULD STILL SEE SCATTERED TO BROKEN CLOUDS ACROSS
THE NORTHERN HALF OF THE FORECAST AREA FROM THE MOISTURE ORIGINATING
OVER LAKE WINNIPEG. HIGHS TO BE A FEW DEGREES WARMER THAN TODAYS
READINGS.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 229 PM CDT FRI OCT 16 2015
ANOTHER COLD NIGHT EXPECTED SATURDAY NIGHT AS THE SURFACE
RIDGE DRIFTS OVER THE GREAT LAKES REGION. ANTICIPATED CLEAR OR
CLEARING SKIES...LIGHT WINDS TO COMBINE WITH THE COOL DRY AIR
MASS TO POSSIBLY PRODUCE WIDESPREAD FREEZING TEMPERATURES AGAIN BY
SUNDAY MORNING. POSSIBLY ADDITIONAL FROST OR FREEZE HEADLINES WILL
BE NEEDED OVER EAST CENTRAL WISCONSIN.
RETURN FLOW DEVELOPS SUNDAY AND CONTINUES INTO MONDAY AS THE HIGH
PRESSURE RIDGE DRIFTS EAST. PROGS CONTINUE TO SUGGEST VERY LIGHT
SHOWERS DEVELOPING IN THE H850 WARM PROD REGION OVER NORTHEAST
WISCONSIN LATER MONDAY INTO MONDAY EVENING. SINCE THE AIR MASS
WILL BE MOISTURE STARVED INITIALLY...WILL FOCUS ANY LOW END CHC
POPS ALONG THE SURFACE FRONT.
FORECAST ISSUE TURNS TO WHERE THIS FRONT STALLS MONDAY NIGHT INTO
TUESDAY PRIOR TO A SURFACE WAVE TRACKING ALONG THIS FRONT TUESDAY
NIGHT INTO WEDNESDAY. CONSENSUS OF AVAILABLE 12Z PROGS SUGGESTS A
MORE SOUTHERN LOCATION OF THE FRONT LATE MONDAY INTO TUESDAY FOR
A DIMINISHED PCPN CHC TREND OR EVEN DRY AND CERTAINLY COOLER.
MEDIUM RANGE MODELS TARGETING THE BEST CHANCE OF RAIN TOWARD
MID WEEK OR TUESDAY NIGHT INTO WEDNESDAY EVENING AS THE SURFACE
WAVE TRACKS OVER SOUTHERN WISCONSIN.
HIGH PRESSURE TO SETTLE BACK INTO THE REGION FOR LATER IN THE WEEK
FOR A TURN TO DRIER CONDITIONS.
ABOVE NORMAL TEMPERATURES EXPECTED MONDAY. SINCE THE FRONT IS
EXPECTED TO SAG A BIT FURTHER SOUTH...TEMPERATURES LIKELY WILL BE
IN THE COOLER BUT CLOSER TO NORMAL RANGE.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1037 PM CDT FRI OCT 16 2015
VFR CONDITIONS EXPECTED TONIGHT THROUGH SATURDAY WITH
JUST SOME CLOUDS BETWEEN 4000 AND 6000 FEET DRIFTING ACROSS THE
AREA AT TIMES. THERE IS A SMALL CHANCE OF SOME LAKE EFFECT CLOUDS
AROUND 3000 FEET AND SNOW FLURRIES NORTH OF RHINELANDER LATE
TONIGHT AND EARLY SATURDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING UNTIL 9 AM CDT SATURDAY FOR WIZ022-038>040-
048>050.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
643 PM CDT FRI OCT 16 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 229 PM CDT FRI OCT 16 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM CENTRAL CANADA TO THE WESTERN GULF OF
MEXICO EARLY THIS AFTERNOON. EAST OF THE RIDGE AXIS...COLD CYCLONIC
FLOW CONTINUES OVER THE WESTERN GREAT LAKES REGION. RECEIVED
SEVERAL REPORTS OF FLURRIES OVER CENTRAL AND NORTH-CENTRAL WI EARLY
THIS MORNING...BUT THOSE REPORTS DRIED UP BY LATE IN THE MORNING.
SCATTERED TO BROKEN CLOUDS ARE PREVAILING ACROSS MUCH OF THE REGION
EARLY THIS AFTERNOON...BUT THESE CLOUDS ARE GRADUALLY MIXING OUT
OVER CENTRAL WI. THIS TREND SHOULD SPREAD EAST FOR THE REST OF THE
AFTERNOON AWAY FROM THE LAKE EFFECT BELTS. LOOKING UPSTREAM...A
FAIRLY SOLID CLOUD MASS IS DIVING SOUTHEAST OVER THE LAKE
WINNIPEG/NORTHERN MINNESOTA REGION. CLOUDS AND TEMPS ARE THE MAIN
FORECAST CONCERNS IN THE SHORT TERM.
TONIGHT...CANADIAN HIGH PRESSURE WILL BE SHIFTING EAST ACROSS THE
NORTHERN MISSISSIPPI VALLEY AND INTO THE WESTERN GREAT LAKES. LOW
LEVEL WINDS WILL REMAIN OUT OF THE NORTHWEST...AND BRING IN
SCATTERED CLOUD COVER OFF LAKE SUPERIOR...WITH AREAS OF BROKEN
CLOUDS AT TIMES...INTO NORTH-CENTRAL AND PARTS OF NE WISCONSIN.
SCATTERED FLURRIES WILL LIKELY CONTINUE OVER THE NORTHERN HALF OF
VILAS CO. THEN MODELS PROJECT THE AREA OF OVERCAST OVER LAKE
WINNIPEG WILL ARRIVE AFTER MIDNIGHT INTO N-C WI. PERHAPS WILL SEE A
SLIGHT UPTICK IN ANY LAKE EFFECT SNOW SHOWERS IN THE SNOW BELTS.
ELSEWHERE...AC DECK OVER MINNESOTA LOOKS TO SLIDE SOUTH OF THE
REGION. SO SHOULD SEE CLEARING THIS EVENING OVER CENTRAL AND EAST-
CENTRAL WI AS DIURNAL HEATING IS LOST. LOW LEVEL WINDS SHOULD
REMAIN IN THE 15-20 KT RANGE...WHICH SHOULD BE GOOD FOR THE COLD
SPOTS TO BECOME CALM FOR PERIODS. REMAINED CONSERVATIVE WITH LOWS
HOWEVER...DUE TO UNCERTAINTY WITH CLOUD COVER. A HARD FREEZE/FROST
STILL LOOKS GOOD FOR THE FOX VALLEY/LAKESHORE.
SATURDAY...HIGH PRESSURE WILL SHIFT TOWARDS THE CENTRAL MISSISSIPPI
VALLEY. WINDS WILL START OUT FROM THE NORTHWEST..THEN BACK MORE
WESTERLY THROUGH THE DAY. AS A RESULT...ANY LAKE CLOUDS AND
FLURRIES ACROSS THE NORTH SHOULD RETREAT TOWARDS THE UPPER PENINSULA
THROUGH THE DAY. SHOULD STILL SEE SCATTERED TO BROKEN CLOUDS ACROSS
THE NORTHERN HALF OF THE FORECAST AREA FROM THE MOISTURE ORIGINATING
OVER LAKE WINNIPEG. HIGHS TO BE A FEW DEGREES WARMER THAN TODAYS
READINGS.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 229 PM CDT FRI OCT 16 2015
ANOTHER COLD NIGHT EXPECTED SATURDAY NIGHT AS THE SURFACE
RIDGE DRIFTS OVER THE GREAT LAKES REGION. ANTICIPATED CLEAR OR
CLEARING SKIES...LIGHT WINDS TO COMBINE WITH THE COOL DRY AIR
MASS TO POSSIBLY PRODUCE WIDESPREAD FREEZING TEMPERATURES AGAIN BY
SUNDAY MORNING. POSSIBLY ADDITIONAL FROST OR FREEZE HEADLINES WILL
BE NEEDED OVER EAST CENTRAL WISCONSIN.
RETURN FLOW DEVELOPS SUNDAY AND CONTINUES INTO MONDAY AS THE HIGH
PRESSURE RIDGE DRIFTS EAST. PROGS CONTINUE TO SUGGEST VERY LIGHT
SHOWERS DEVELOPING IN THE H850 WARM PROD REGION OVER NORTHEAST
WISCONSIN LATER MONDAY INTO MONDAY EVENING. SINCE THE AIR MASS
WILL BE MOISTURE STARVED INITIALLY...WILL FOCUS ANY LOW END CHC
POPS ALONG THE SURFACE FRONT.
FORECAST ISSUE TURNS TO WHERE THIS FRONT STALLS MONDAY NIGHT INTO
TUESDAY PRIOR TO A SURFACE WAVE TRACKING ALONG THIS FRONT TUESDAY
NIGHT INTO WEDNESDAY. CONSENSUS OF AVAILABLE 12Z PROGS SUGGESTS A
MORE SOUTHERN LOCATION OF THE FRONT LATE MONDAY INTO TUESDAY FOR
A DIMINISHED PCPN CHC TREND OR EVEN DRY AND CERTAINLY COOLER.
MEDIUM RANGE MODELS TARGETING THE BEST CHANCE OF RAIN TOWARD
MID WEEK OR TUESDAY NIGHT INTO WEDNESDAY EVENING AS THE SURFACE
WAVE TRACKS OVER SOUTHERN WISCONSIN.
HIGH PRESSURE TO SETTLE BACK INTO THE REGION FOR LATER IN THE WEEK
FOR A TURN TO DRIER CONDITIONS.
ABOVE NORMAL TEMPERATURES EXPECTED MONDAY. SINCE THE FRONT IS
EXPECTED TO SAG A BIT FURTHER SOUTH...TEMPERATURES LIKELY WILL BE
IN THE COOLER BUT CLOSER TO NORMAL RANGE.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 643 PM CDT FRI OCT 16 2015
VFR CONDITIONS EXPECTED TONIGHT THROUGH SATURDAY WITH
JUST SOME CLOUDS BETWEEN 4000 AND 6000 FEET DRIFTING ACROSS THE
AREA AT TIMES. THERE IS A SMALL CHANCE OF SOME LAKE EFFECT CLOUDS
AROUND 3000 FEET NORTH OF RHINELANDER LATE TONIGHT AND EARLY
SATURDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM 10 PM THIS EVENING TO 9 AM CDT SATURDAY FOR
WIZ022-038>040-048>050.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......RDM
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 234 PM CDT THU OCT 15 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A
MODERATELY STRONG SHORTWAVE MOVING ACROSS NORTHERN WISCONSIN EARLY
THIS AFTERNOON. THIS SHORTWAVE IN CONCERT WITH STEEP LAPSE RATES
THROUGH 500MB IS GENERATING SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS THE UPPER PENINSULA AND THE NORTHERN HALF OF
WISCONSIN. SEVERAL REPORTS HAVE BEEN RECEIVED OF SMALL HAIL IN THE
STRONGER SHOWERS/STORMS. THESE SHOWERS WILL CONTINUE TO MOVE
SOUTHEAST ACROSS THE REGION FOR THE REST OF THE AFTERNOON AND HAVE
INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS ACROSS THE WHOLE FORECAST
AREA. BEHIND THE SHORTWAVE...AN ARCTIC COLD FRONT IS MOVING
SOUTHEAST JUST NORTH OF THE BOUNDARY WATERS OF MINNESOTA. SCATTERED
TO BROKEN CLOUD COVER EXISTS AHEAD AND BEHIND THE BOUNDARY...ALONG
WITH RAIN/SNOW SHOWERS. PRECIP TRENDS AND TEMPS ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...THE SHORTWAVE TROUGH WILL EXIT THE REGION BY EARLY IN THE
EVENING TAKING THE MORE WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS WITH IT. THE ARCTIC FRONT WILL LAG BEHIND THE
SHORTWAVE AND MAKE STEADY PROGRESS ACROSS THE REGION OVER THE COURSE
OF THE NIGHT. 850MB TEMPS WILL QUICKLY FALL TO MINUS 7-8C OVER
WESTERN LAKE SUPERIOR BY SHORTLY AFTER MIDNIGHT WHICH WILL PROMOTE
SCATTERED LAKE EFFECT RAIN AND SNOW SHOWERS OVER N-C WISCONSIN.
SHOULD SEE SCATTERED TO BROKEN CLOUDS ARRIVE ELSEWHERE AS THE COLDER
AIR FILTERS IN. MORE BREAKS IN THE CLOUDS CAN BE EXPECTED IN THE
DOWNSLOPING AREAS OF NE WISCONSIN. WITH A GUSTY NW WIND...LOWS TO
FALL INTO THE LOWER TO MIDDLE 30S. NO FROST/FREEZE HEADLINES FOR
THE FOX VALLEY AND LAKE SHORE TONIGHT DUE TO THE GUSTY WINDS.
FRIDAY...COLD ARCTIC AIR WILL BE ENTRENCHED ACROSS THE REGION. LAKE
EFFECT RAIN AND SNOW SHOWERS WILL CONTINUE ACROSS THE MORNING OVER N-
C WI. ELSEWHERE...SCT MORNING CLOUDS MAY TURN BROKEN FOR A PERIOD
LATE IN THE MORNING AND EARLY AFTERNOON AS LOW LEVEL LAPSE RATES
STEEPEN. BUT THERE WILL BE AMPLE DRY AIR ABOVE THE INVERSION WHICH
SHOULD CAUSE ANY DIURNAL CLOUDS TO GRADUALLY MIX OUT DURING THE
AFTERNOON. FLOW REMAINS ONSHORE OFF LAKE SUPERIOR...SO CLOUDS WILL
PERSIST LONGER OVER N-C WI. COOL HIGHS RANGING THROUGH THE 40S.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 234 PM CDT THU OCT 15 2015
CONTINUED COLD AIR ADVECTION FRIDAY NIGHT INTO SUNDAY WILL ALLOW
VERY CHILLY OVERNIGHT LOW TEMPERATURES. LAKE CLOUDS ALONG WITH
SMALL MIXED PCPN CHANCES MAY LINGER OVER THE FAR NORTH AND
NORTHEAST FRIDAY NIGHT...OTHERWISE THE DRYING AIR MASS WITH
SURFACE DEW POINT TEMPERATURES FALLING TO THE TEENS AND LOWER 20S
WILL EVENTUALLY PROVIDE CLEARING SKIES. THE PRIMARY ISSUE WILL BE
THE WIDESPREAD FREEZING TEMPERATURES...TEENS NORTH TO 20S CENTRAL
AND EAST CENTRAL WISCONSIN LATE FRIDAY NIGHT. WILL HOIST A FREEZE
WATCH FOR EAST CENTRAL WISCONSIN INCLUDING THE LAKESHORE REGION
FOR LATE FRIDAY NIGHT. AREAS RIGHT ALONG THE LAKE AND BAY WILL
LIKELY BE PROTECTED BUT INLAND AREAS OF DOOR WILL AT LEAST SEE A
GOOD FROST. DEPENDING ON WHAT HAPPENS SATURDAY MORNING...MORE
FROST AND FREEZE HEADLINES MAY BE NEEDED THE FOLLOWING NIGHT AS
THE SURFACE HIGH PRESSURE RIDGE DRIFTS OVER.
RETURN FLOW BEGINS LATER SUNDAY WITH THE SURFACE HIGH DRIFTING
EAST OF THE AREA. TEMPS MAY REBOUND CLOSER TO NORMAL SUNDAY AND
THEN ABOVE NORMAL MONDAY. SOME PROGS ATTEMPT TO BRING IN PCPN
MONDAY WITH THE WAA...BUT WILL KEEP A DRY FORECAST GOING FOR THE
START OF THE DAY DUE TO THE AIR MASS WILL NEED TO SATURATE FROM
THE RECENT INTRUSION OF LOW SURFACE DEWPOINTS.
PROGS INDICATE A FAIRLY PROGRESSIVE PATTERN NEXT WEEK. HOWEVER
MEDIUM RANGE MODELS TIMING SLOWLY DIVERT AS THE WEAK WEARS ON.
THE NEXT CHANCE OF PRECIPITATION WILL BE ASSOCIATED WITH A SHORT
WAVE TROUGH SLIDING OVER THE NORTHERN PLAINS TUESDAY INTO
WEDNESDAY. NARROW PLUME OF MOISTURE WITH THE BEST WAA WILL SLIDE
OVER THE AREA AHEAD OF THE COLD FRONT LATER TUESDAY INTO TUESDAY
NIGHT.
ONLY A GLANCING SHOT OF COOLER AIR TO BRUSH OVER THE NORTHERN
GREAT LAKES REGION WEDNESDAY NIGHT BEFORE A BROAD UPPER RIDGE
BUILDS OVER THE AREA AREA THURSDAY. ANOTHER DEVELOPING AND
POSSIBLE DEEPER SYSTEM TAKES AIM AT THE AREA LATE NEXT WEEK.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1208 PM CDT THU OCT 15 2015
LIGHT SHOWERS WILL IMPACT NORTHERN WISCONSIN THIS
AFTERNOON AHEAD OF A STRONG COLD FRONT. FLIGHT CONDITIONS ARE
EXPECTED TO REMAIN VFR ALTHOUGH WITH GUSTY NORTHWEST WINDS. THE
PASSAGE OF THE FRONT WILL BRING AN INFLUX OF LOW CLOUDS TO THE
REGION ALONG WITH RAIN AND SNOW SHOWERS INTO NORTHERN WI TONIGHT.
MVFR CIGS AND VSBYS ARE POSSIBLE AT RHI AFTER MIDNIGHT. UNCERTAINTY
IS TOO HIGH TO INCLUDE MVFR CONDITIONS AT OTHER TAF SITES THOUGH.
CIGS TO RISE WITH DAYTIME HEATING ON FRIDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM FRIDAY EVENING THROUGH SATURDAY MORNING FOR
WIZ022-038>040-048>050.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
148 AM MST SAT OCT 17 2015
.SYNOPSIS...
A SERIES OF SLOW MOVING LOW PRESSURE SYSTEMS WILL BRING ELEVATED
CHANCES OF SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH THE MIDDLE
OF NEXT WEEK. SHOWERS AND STORMS ARE POSSIBLE AGAIN TODAY AND
SUNDAY WITH A SLIGHT DRYING TREND ON MONDAY. THIS WILL BE SHORT
LIVED HOWEVER AS A SECOND LOW MOVES INTO THE DESERT SOUTHWEST ON
TUESDAY AND REMAINS IN PLACE THROUGH THURSDAY. DRIER AIR WILL MOVE
INTO THE AREA LATE NEXT WEEK.
&&
.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY REVEALS DIFFLUENT FLOW ACROSS MUCH
OF THE DESERT SOUTHWEST...WITH SEVERAL UPPER LOWS/SMALL-SCALE
SHORTWAVES IN/AROUND ARIZONA. A WEAK SHORTWAVE WAS NOTED ACROSS
SOUTHEAST CALIFORNIA AS OF 08Z...WITH ANOTHER MUCH STRONGER WAVE OVER
THE GULF OF CALIFORNIA. MEANWHILE ANOTHER LOW WAS DEEPENING OFF THE
COAST OF OREGON. ALL OF THESE WILL PLAY A ROLE IN THE WEATHER ACROSS
THE REGION AT VARIOUS TIMES THROUGH THE MIDDLE OF NEXT WEEK.
THE SOUTHERN-MOST SHORTWAVE OVER THE GULF OF CALIFORNIA IS FAIRLY
POTENT AND HAS SOME UPPER LEVEL SUPPORT TO WORK WITH...HAS DEEPENED
SOMEWHAT SINCE MIDNIGHT...AND IS LOCATED WITHIN AN AREA OF MODEST MID
LEVEL INSTABILITY. UNFORTUNATELY...IT HASN`T BEEN INITIALIZED
PARTICULARLY WELL BY ANY OF THE 00Z OR 06Z LARGE-SCALE DETERMINISTIC
MODELS. ONLY THE RAP AND THE HRRR /NOT SURPRISINGLY/ HAVE CORRECTLY
IDENTIFIED THIS FEATURE AND MATCH CURRENT RADAR/OBSERVATIONAL TRENDS.
EXPECTING SHOWERS AND STORMS TO CONTINUE TO BLOSSOM OVERNIGHT ACROSS
PORTIONS OF ARIZONA...BUT QUICKLY SHIFT EAST INTO NEW MEXICO LATER
TODAY. AS SUCH...I WILL MAINTAIN 20-30 POPS THIS MORNING TO ACCOUNT
FOR THE POSSIBILITY OF SHOWERS WITH THIS WAVE. MEANWHILE...THE WAVE
OVER THE LOWER COLORADO RIVER VALLEY WILL SHIFT EAST THIS AFTERNOON
AND INTERACT WITH A FAIRLY FAVORABLE ENVIRONMENT. THERMODYNAMIC
PARAMETERS ARE NOT AS IMPRESSIVE AS THEY WERE YESTERDAY...MLCAPES ARE
ONLY AROUND 250-500 J/KG AND DEEP LAYER /0-6KM/ SHEAR IS ONLY AROUND
15KTS. EXPECTING SOME ACTIVITY LATER THIS AFTERNOON INTO THE EVENING
HOURS...BUT PERHAPS NOT AS MUCH AS WHAT WAS SEEN ON FRIDAY.
SUNDAY AND MONDAY LOOK TO BE LESS ACTIVE STORM-WISE ALTHOUGH BROAD
SOUTHWESTERLY FLOW ALOFT...ELEVATED PWATS...MODEST INSTABILITY...AND
THE SUGGESTION OF WEAK/SUBTLE SHORTWAVES IN ALL OPERATIONAL MODELS COULD
STILL RESULT IN MOUNTAIN SHOWERS AND STORMS BOTH DAYS. MITIGATING
FACTORS ACROSS THE DESERTS SUCH AS INCREASED CLOUD COVER COULD LIMIT
INSTABILITY TO THE POINT WHERE MLCAPES ARE VIRTUALLY ZERO...BUT STILL
SEEMS THAT SLIGHTLY HIGHER THAN NORMAL POPS ARE WARRANTED /ESPECIALLY
EAST OF PHOENIX/.
MEANWHILE...THE LOW PRESENTLY WEST OF OREGON WILL MOVE INLAND AND
DIVE SOUTHWARD...EVENTUALLY STALLING ACROSS ARIZONA ON TUESDAY.
QUITE A BIT OF UNCERTAINTY REMAINS IN TERMS OF PRECIP CHANCES AS I
WOULD NORMALLY EXPECT IMPRESSIVE PWATS GIVEN THE POTENTIAL FOR STRONG
SOUTHERLY FLOW AHEAD OF THIS SYSTEM. WHILE IT SEEMS INCREASINGLY
LIKELY THAT SHOWERS WILL BE POSSIBLE TUESDAY THROUGH THURSDAY OF NEXT
WEEK...GEFS/NAEFS PWATS AREN`T PARTICULARLY HIGH AND AREN`T FORECAST
TO RISE MUCH ABOVE 1-2 STDEV ABOVE NORMAL /NOT EVEN INTO THE 90TH
PERCENTILE/. NAEFS POPS ONLY SHOWING 40-50 PERCENT MAX ON TUESDAY
WITH THE ARRIVAL OF THE LOW...THEN QUICKLY DROPPING OFF WEDNESDAY AND
THURSDAY. FOLLOWED THE NAEFS FAIRLY CLOSELY FOR NEXT WEEK AND WILL
HOLD SHORT OF BUMPING UP POPS MUCH FURTHER UNLESS PWATS TAKE A
NOTEWORTHY JUMP UPWARD. ALL DETERMINISTIC AND PROBABILISTIC MODELS
SUGGEST A RETURN TO DRY WESTERLY FLOW LATE IN THE WEEK INTO NEXT
WEEKEND.
AS FOR TEMPERATURES...ASIDE FROM TODAY MOST LOCATIONS SHOULD BE
LOOKING AT BELOW NORMAL TEMPERATURES THROUGH LATE NEXT WEEK COURTESY
OF UPPER LEVEL TROUGHING/INCREASED CLOUD COVER. WITH THE UPPER LOW
OVERHEAD ON TUESDAY...HIGHS COULD CONCEIVABLY STRUGGLE TO BREAK OUT
OF THE MID 80S PER LATEST CONSENSUS MODEL GUIDANCE AND TEMPERATURES
WERE LOWERED ACCORDINGLY NEXT WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SCT SHOWERS AND GUSTY E/NE SFC WINDS WILL BE THE PRIMARY AVIATION
CONCERNS THROUGH SATURDAY AFTERNOON. AN ISOLD TSRA COULD BE EMBEDDED
WITH THE SHOWERS...HOWEVER COVERAGE LOOKS VERY SPARSE. THE MOST
LIKELY TIME FRAME FOR SCT SHOWERS WILL BE THROUGH 08Z TONIGHT...THEN
AGAIN SATURDAY AFTERNOON. SFC WINDS SHOULD MAINTAIN A GENERAL
EASTERLY COMPONENT THROUGH THE PERIOD...THOUGH COULD OCCASIONAL
DRIFT BETWEEN NNE AND SE. STRONGER GUSTS ABOVE 20KT WILL BE LIKELY
LATE SATURDAY MORNING/EARLY AFTERNOON.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SHOWERS AND A FEW ISOLD THUNDERSTORMS TONIGHT WILL BE THE MAIN
AVIATION CONCERN...WITH IMPROVING CONDITIONS ON SATURDAY. KBLH WILL
BE MOST SUSCEPTIBLE TO TO PASSING STORMS...THOUGH LIMITED COVERAGE
PRECLUDES MENTION IN THIS TAF PACKAGE. SHIFTING VARIABLE SFC WINDS
WILL BE COMMON...AND OVERALL CONFIDENCE IN TIMING ANY SPECIFIC WIND
SHIFT IS RATHER LOW.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UNSETTLED WEATHER EARLY NEXT WEEK WILL SLOWLY TRANSITION TO DRIER
CONDITIONS WITH SEVERAL DISTURBANCES PASSING THROUGH THE DISTRICT.
LIGHTER SHOWERS WILL FAVOR HIGHER TERRAIN LOCATIONS OF EASTERN
ARIZONA. AFTERNOON HUMIDITY VALUES IN A 25 TO 35 PERCENT RANGE EARLY
IN THE WEEK WILL ONLY DECREASE TO A 15 TO 25 PERCENT RANGE BY THE
MIDDLE AND END OF NEXT WEEK. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. A FEW STRONGER NORTHERLY WIND GUSTS DOWN THE LOWER
COLORADO RIVER VALLEY WILL BE POSSIBLE TUESDAY AND WEDNESDAY
AFTERNOON. OTHERWISE...WINDS WILL GENERALLY BE LIGHT AND NOT A FIRE
WEATHER IMPACT.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...MO
FIRE WEATHER...DEWEY
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 PM MST FRI OCT 16 2015
.SYNOPSIS...EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
SATURDAY FOLLOWED BY LESS COVERAGE OF SHOWERS AND THUNDERSTORMS
SUNDAY INTO MONDAY. A LOW PRESSURE SYSTEM WILL THEN BRING A CHANCE
OF SHOWERS AND THUNDERSTORMS TUESDAY INTO WEDNESDAY. NEAR NORMAL
DAYTIME TEMPERATURES WILL PREVAIL THIS WEEKEND FOLLOWED BY BELOW
NORMAL HIGH TEMPERATURES BY MIDWEEK.
&&
.DISCUSSION...KEMX WSR-88D DETECTED NUMEROUS 30-60 DBZ ECHOES MOVING
NEWD ACROSS CENTRAL/ERN PIMA COUNTY...ERN SANTA CRUZ/WRN COCHISE
COUNTY...AND SE PINAL/SWRN GRAHAM COUNTY AT THIS TIME. PRECIP-FREE
CONDITIONS WERE ONGOING ACROSS WRN PIMA COUNTY...AND GENERALLY FROM
CENTRAL GRAHAM COUNTY INCLUDING SAFFORD NEWD TO THE WHITE MOUNTAINS.
IR SATELLITE IMAGERY INDICATED CLOUDY SKIES AREA-WIDE...AND THE
COLDEST CLOUD TOPS WERE GENERALLY WARMING DURING THE PAST 1-2 HOURS.
BASED ON SATELLITE/RADAR TRENDS...APPEARS THAT SHOWERS/TSTMS SHOULD
DECREASE MARKEDLY ACROSS THE TUCSON METRO AREA DURING THE NEXT 2-3
HOURS OR SO. HOWEVER...SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
TSTMS WILL LIKELY CONTINUE AT LEAST FOR MUCH OF THE REST OF TONIGHT
ACROSS COCHISE AND GRAHAM COUNTIES AND EVENTUALLY INTO GREENLEE
COUNTY. THE 17/03Z HRRR AND TO AN EXTENT THE 17/00Z NAM12 SUPPORTS
THIS NOTION.
THUS...SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS THE
REST OF TONIGHT ESPECIALLY ACROSS ERN SECTIONS. HAVE MAINTAINED JUST
A SLIGHT CHANCE OF SHOWERS/TSTMS INTO SAT MORNING ACROSS WRN PIMA
COUNTY. THE OFFICIAL FORECAST DEPICTS SCATTERED TO NUMEROUS SHOWERS/
TSTMS SAT AFTERNOON FROM TUCSON EAST AND SOUTH...AND ONLY ISOLATED
SHOWERS/TSTMS ACROSS WRN PIMA COUNTY. HIGH TEMPS SAT ARE FORECAST TO
AVERAGE WITHIN A DEGREE-OR-TWO OF NORMAL.
&&
.AVIATION...VALID THRU 18/06Z.
EXPECT NUMEROUS -SHRA AND SCATTERED -TSRA ESPECIALLY FROM KTUS
VICINITY EASTWARD THE REST OF TONIGHT. ISOLATED TO SCATTERED -TSRA/
-SHRA SATURDAY MORNING...THEN SCATTERED TO NUMEROUS -TSRA/-SHRA
RETURNING SATURDAY AFTERNOON INTO SATURDAY EVENING. MVFR CONDITIONS
AND BRIEF IFR CONDITIONS WILL OCCUR AT TIMES THRU THE PERIOD.
OTHERWISE...CLOUD DECKS WILL BE AROUND 8-12K FT AGL AND SURFACE WIND
WILL GENERALLY BE ELY/SELY AT 5-15 KTS WITH GUSTS TO AROUND 25 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS AGAIN SATURDAY FOLLOWED BY ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS SUNDAY INTO MONDAY. THERE IS A CHANCE OF
SHOWERS AND THUNDERSTORMS TUESDAY AND WEDNESDAY...THEN A DRYING
TREND WILL OCCUR THURSDAY INTO FRIDAY.
&&
.PREV DISCUSSION /100 PM MST/...SATURDAY WE HAVE THE MAIN UPPER
LEVEL TROUGH AXIS MOVING INTO THE AREA LATE IN THE DAY WHICH SHOULD
PROVIDE A FOCUS FOR CONVECTION. WHILE TIMING OF THIS MAY CHANGE A
SOME...AT THIS TIME IT LOOKS LIKE ANOTHER LINE OF CONVECTION MAY
DEVELOP OVER CENTRAL/EASTERN PIMA COUNTY AND MOVE EAST ACROSS THE
AREA THROUGH THE AFTERNOON. STILL HAVE SOME SHEAR AVAILABLE WITH THE
POTENTIAL FOR MORE CAPE SO THIS WILL NEED TO BE WATCHED FOR SOME
POTENTIALLY STRONG/SEVERE STORMS AND ALSO FOR POSSIBLE HEAVY RAINERS
THAT MAY MOVE ACROSS AREAS THAT GET DECENT RAINS THROUGH TONIGHT.
AS THE TROUGH AXIS SWINGS NE OF THE AREA SATURDAY NIGHT IT WILL TAKE
THAT BATCH OF PRECIPITATION WITH IT. HOWEVER...AS THEY SAY ON
TV...BUT WAIT THERE`S MORE. THE ATMOSPHERE IN ITS ATTEMPT TO BUILD A
LONG WAVE TROUGH ALONG THE WEST COAST IN THE LONG TERM /SEE 5-WAVE
HEIGHT FIELDS THROUGH THE NEXT 10-DAYS/ IT DROPS ANOTHER LOW ACROSS
CALIFORNIA AND SWINGS A VORT LOBE UP ACROSS WESTERN AZ BUT CLOSE
ENOUGH TO KICK OFF SOME CONVECTION ACROSS PARTS OF SE AZ SUNDAY
AFTERNOON AND EVENING. THIS WOULD PRIMARILY AFFECT THE AREA FROM
TUCSON EASTWARD.
BEYOND THAT IT GETS REALLY INTERESTING ONCE AGAIN. A MORE
SIGNIFICANT SHORT WAVE DROPS INTO THE BACK SIDE OF THE DEVELOPING
TROUGH MONDAY FORMING A SIGNIFICANT CUTOFF LOW OVER SOUTHERN
CALIFORNIA MONDAY NIGHT INTO TUESDAY. DEPENDING ON TIMING AND
PLACEMENT WILL LIKELY HAVE SOME CONVECTION TO DEAL WITH ON MONDAY
FOR PORTIONS OF SE AZ AND LIKELY EASTERN AREAS. THIS LOW IS THEN
FORECAST TO MEANDER ACROSS AZ THROUGH WEDNESDAY AND POSSIBLY
THURSDAY BEFORE LIFTING OUT TO THE NE. IF THIS INDEED PLAYS OUT LIKE
THIS WE WILL HAVE PLENTY OF OPPORTUNITIES FOR SHOWERS AND
THUNDERSTORMS TUESDAY AND WEDNESDAY TO GO ALONG WITH COOLING
TEMPERATURES. HAVE RAMPED UP POPS THROUGH THIS PERIOD TO REFLECT
THIS IDEA.
LOOKING EVEN FURTHER AHEAD...AS THE LONG WAVE TROUGH LOOKS TO
ESTABLISH ITSELF ACROSS THE WEST THERE IS A GOOD CHANCE WE WILL SEE
UNSETTLED WEATHER AT TIMES WELL INTO THE NEXT WEEKEND AND BEYOND.
THE EXPECTED WETTER THAN NORMAL WINTER MAY BE GETTING AN EARLY
START. CERNIGLIA
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1232 AM EDT SAT OCT 17 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 306 PM EDT FRI OCT 16 2015
STRONG HIGH PRESSURE WILL BRING DRY WEATHER TO THE OHIO
VALLEY THROUGH THE MIDDLE OF NEXT WEEK. THE COLDEST TEMPERATURES OF
THE SEASON ARE EXPECTED OVER THE WEEKEND WITH A HARD FREEZE LIKELY
FOR MANY AREAS. WARMER WEATHER WILL RETURN STARTING MONDAY AND
CONTINUE THROUGH THE WEEK...WITH THE PASSAGE OF A WEAK FRONT
BRINGING THE NEXT CHANCE FOR A FEW SHOWERS WEDNESDAY NIGHT AND
THURSDAY.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 931 PM EDT FRI OCT 16 2015
UPDATE...
NO CHANGES TO CURRENT FORECAST OR HEADLINES. ANY INCREASED CLOUD
COVERAGE OVER THE NORTHEAST PORTIONS OF THE FORECAST AREA IS
STILL EXPECTED TO HAVE A NEGLIGIBLE AFFECT ON OVERNIGHT LOWS.
TEMPERATURES SHOULD STILL GET CLOSE TO THE FREEZING MARK EVEN
OVER THOSE COUNTIES. UPDATED GRIDS HAVE BEEN SENT.
PREVIOUS DISCUSSION...
THE PRIMARY CHALLENGE FOR THE NEAR TERM IS THE POTENTIAL FOR NEAR-
FREEZING OR SUBFREEZING TEMPS LATE TONIGHT...AND ANY IMPACT FROM
LAKE MICHIGAN INDUCED CU/STRATOCU.
COLD DRY AIR WILL CONTINUE TO OVERSPREAD THE REGION TONIGHT WITH THE
STRONG HIGH PRESSURE SETTLING OVER THE MID MISSISSIPPI VALLEY. BULK
OF THE FORECAST AREA WILL REMAIN MOSTLY CLEAR WITH LIGHT WINDS TO
THE EAST OF THE HIGH CENTER LIKELY TO NOT DETER WIDESPREAD FROST
ACCRUAL AFTER MIDNIGHT.
COMBINATION OF A WAVE ALOFT REINFORCING THE UPPER TROUGH OVER THE
GREAT LAKES OVERNIGHT AND FAVORABLE LOW LEVEL FLOW OFF THE LAKES
WILL KEEP SOME FORM OF LOWER CLOUDS DRIFTING THROUGH NORTHERN
INDIANA AND POSSIBLY WORKING INTO THE NORTHEAST QUARTER OF THE
FORECAST AREA OVERNIGHT. NAM IS MOST AGGRESSIVE IN PUSHING DEEPER
MOISTURE IN THE 925-850MB LAYER INTO AREAS NORTHEAST OF THE INDY
METRO...AND THE RAP IS STARTING TO HINT AT THIS TOWARD DAWN AS WELL.
EVEN WITH BROKEN CLOUDS DRIFTING INTO NORTHEAST COUNTIES LATE...
THOSE AREAS ARE LIKELY TO EXPERIENCE ENOUGH TIME WITH MAINLY CLEAR
SKIES THIS EVENING THAT TEMPS SHOULD STILL MAKE A RUN TOWARDS THE
FREEZING MARK...WITH POTENTIAL TO GO LOWER IF LESS CLOUDS DEVELOP
THAN CURRENTLY THINKING. FOR THAT REASON...HAVE CHOSEN TO UPGRADE
THE ENTIRE FORECAST AREA TO A FREEZE WARNING OVERNIGHT. NOT EVERYONE
IS GOING TO GET TO 32 OR LOWER...BUT STILL FEEL A WIDESPREAD FROST
IS LIKELY FOR MUCH OF THE AREA.
TEMPS...LEANED TOWARDS LOW END OF MOS AND EVEN UNDERCUT IT BY A FEW
DEGREES IN SOME AREAS. WITH THE LACK OF SIGNIFICANT PRECIP OVER THE
LAST SEVERAL WEEKS...TEMP RESPONSE HAS OUTPACED MOS GUIDANCE ON BOTH
HIGHS AND LOWS THE LAST FEW DAYS. EVEN WITH POTENTIAL FOR SOME
CLOUDS LATE...THINK UPPER 20S AND LOWER 30S WILL BE COMMON FOR LOWS
OVERNIGHT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 306 PM EDT FRI OCT 16 2015
FORECAST CHALLENGES ARE ON TEMPS THROUGH THE PERIOD...INCLUDING THE
POTENTIAL FOR THE GROWING SEASON TO COME TO AN OFFICIAL END EARLY
SUNDAY MORNING.
AFOREMENTIONED STRONG HIGH PRESSURE WILL DRIFT ACROSS THE OHIO
VALLEY THROUGH THE SHORT TERM PERIOD...AND BE THE PRIMARY INFLUENCE
ON WEATHER FOR THE NEXT FEW DAYS. SCATTERED CU/STRATOCU MAY BE A BIT
MORE PREVALENT ON SATURDAY...ESPECIALLY ACROSS THE NORTHEAST HALF OF
THE FORECAST AREA...AS AN UPPER LEVEL WAVE PASSES THROUGH THE GREAT
LAKES AND SOUNDINGS/RH PROGS SUPPORT INCREASED MOISTURE IN THE 925-
850MB LAYER. ANY CU WILL DISSIPATE AROUND OR SHORTLY AFTER SUNSET
SATURDAY EVENING AS DRIER AIR AND DEEP SUBSIDENCE OVERSPREADS THE
REGION.
WITH THE HIGH CENTERED OVER THE AREA AND THE 850MB COLD POOL NEARBY
SATURDAY NIGHT...BEST CHANCE AT A WIDESPREAD HARD FREEZE OVER THE
AREA WILL EXIST. HAVE MAINTAINED THE FREEZE WATCH FOR SATURDAY
NIGHT/EARLY SUNDAY FOR NOW...BUT HAVE NO DOUBT THAT THIS WILL BE
UPGRADED TO A WARNING EITHER TONIGHT OR DURING THE DAY SATURDAY.
WARM ADVECTION WILL COMMENCE BEGINNING SUNDAY AND CONTINUE THROUGH
THE REST OF THE SHORT TERM WITH UPPER RIDGING EXPANDING INTO THE
MISSISSIPPI AND OHIO VALLEYS ON MONDAY. TIGHTENING SURFACE PRESSURE
GRADIENT WILL DEVELOP AND PRODUCE BREEZY SOUTHWEST FLOW MONDAY
BETWEEN THE HIGH JUST TO OUR EAST AND A COLD FRONT MOVING THROUGH
THE NORTHERN PLAINS.
TEMPS...GOING ALONG WITH TEMP BEHAVIOR LAST FEW DAYS...LEANED
TOWARDS FAR ENDS OF THE GUIDANCE ON BOTH HIGHS AND LOWS THROUGH MUCH
OF THE PERIOD. UNDERCUT MOS MOST EVERYWHERE SATURDAY NIGHT WITH MANY
AREAS BOTTOMING OUT IN THE 25 TO 30 DEGREE RANGE UNDER IDEAL
RADIATIONAL COOLING SETUP. HIGHS WILL RECOVER BACK INTO THE MID
AND UPPER 60S BY MONDAY AND SOME AREAS IN THE WABASH VALLEY COULD
MAKE A RUN AT 70.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 218 PM EDT FRI OCT 16 2015
MODELS ARE IN GOOD AGREEMENT ON UPPER RIDGING IN PLACE OVER THE AREA
TO BEGIN THE LONG TERM. SOLUTION SPREAD INCREASES BY MID WEEK WITH
DIFFERENCES IN TIMING/PLACEMENT OF A SHORTWAVE MOVING ACROSS THE
NORTHERN PLAINS AND THROUGH THE GREAT LAKES. ACCEPTED INITIALIZATION
WITH ONLY QUALITY CONTROL ADJUSTMENTS RESULTING IN SLIGHT CHANCE
POPS IN THE NORTHERN AND CENTRAL COUNTIES TAPERING TO DRY SOUTH.
TEMPERATURES WILL RUN SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE UPPER
60S TO LOWER 70S AND LOWS IN THE MID 40S TO LOWER 50S.
&&
.AVIATION /DISCUSSION FOR 170600Z TAF ISSUANCE/...
ISSUED AT 1232 AM EDT SAT OCT 17 2015
HIGH CONFIDENCE THAT DRY ATMOSPHERE AND HIGH PRESSURE WILL RESULT IN
VFR CONDITIONS THROUGH THE TAF PERIOD WITH JUST SOME LINGERING
CIRRUS AND PERHAPS SCT DIURNAL CU. NORTHWEST WINDS 6 KNOTS OR LESS
WILL INCREASE A BIT TO AROUND 10 KNOTS AFTER 15Z.
HOWEVER...WEAKENING SURFACE PRESSURE GRADIENT WILL DISCOURAGE
AFTERNOON GUSTS. WINDS WILL BECOME LIGHT NORTHWEST OR CALM AFTER
23Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
FREEZE WARNING FROM 3 AM TO 10 AM EDT SATURDAY FOR INZ021-
028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...TDUD
SHORT TERM...RYAN
LONG TERM....CP
AVIATION...MK
AREA FORECAST DISCUSSION
NWS JACKSON KY
132 AM EDT SAT OCT 17 2015
.UPDATE...
ISSUED AT 132 AM EDT SAT OCT 17 2015
HIGH PRESSURE CONTINUES TO MOVE SE INTO THE REGION AT THIS
OVERNIGHT HOUR. GRIDS ARE IN GOOD SHAPE SO JUST SOME UPDATES TO
THE TEMP/DEWS/WINDS TO INCORPORATE LATEST OBS AND TRENDS.
UPDATE ISSUED AT 1040 PM EDT FRI OCT 16 2015
FORECAST REMAINS ON TRACK TONIGHT...SO DID A QUICK REFRESH TO THE
GRIDS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS.
UPDATE ISSUED AT 745 PM EDT FRI OCT 16 2015
WITH CLEAR SKIES...VALLEY TEMPS ARE DROPPING OFF QUICKLY THIS
EVENING SO NUDGED TEMPS DOWN TO REFLECT THIS TREND. STILL EXPECT
PATCHY FROST TONIGHT WITH LOWS AROUND FREEZING.
OTHERWISE...FORECAST REMAINS ON TRACK. SENT UPDATED GRIDS TO NDFD
AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 220 PM EDT FRI OCT 16 2015
...COLDEST AIR OF THE SEASON THUS FAR ARRIVES THIS WEEKEND...
17Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING INTO THE OHIO
VALLEY. THIS IS BRINGING COOLER AND DRIER AIR INTO EAST KENTUCKY
ON NORTHWEST TO NORTH WINDS OF AROUND 10 MPH WITH GUSTS TO 15
MPH. THE HIGH HAS ALSO CLEARED THE SKIES AND PLENTY OF SUNSHINE IS
SUPPORTING TEMPERATURES IN THE LOWER 60S ATTM WITH DEWPOINTS
MIXING DOWN INTO THE UPPER 20S AND LOWER 30S.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST AS THEY ALL EASE A TIGHTENING TROUGH TO
OUR NORTH...INTO THE GREAT LAKES AND THEN TO EASTERN CANADA.
HEIGHTS WILL FALL THROUGH THE OHIO VALLEY TONIGHT AND SATURDAY AS
THIS TROUGH PASSES...THOUGH ANY ENERGY ASSOCIATED WITH IT WILL
STAY NORTH OF KENTUCKY. GIVEN THE MODEL AGREEMENT HAVE FAVORED THE
HIGHER RESOLUTION HRRR AND NAM12 FOR WEATHER DETAILS...WITH
SPECIAL EMPHASIS ON THE COOP MOS FROM THE GFS FOR POINT BASED LOWS
EACH NIGHT.
SENSIBLE WEATHER WILL BE RATHER QUIET THROUGH THE WEEKEND WITH
THIS MAINLY A TEMPERATURE FORECAST AS EVEN THE CLOUDS WILL BE FEW
AND FAR BETWEEN. HOWEVER...A CANADIAN HIGH PRESSURE SYSTEM IN
PLACE DURING THIS TIME OF YEAR WILL ALSO MEAN CHILLY LOW
TEMPERATURES AND LIKELY FROST. IN FACT...THAT IS EXACTLY WHAT EAST
KENTUCKY IS FACING TONIGHT AND SATURDAY NIGHT. DO EXPECT
TEMPERATURES TO BE MORE UNIFORM TONIGHT THAN TOMORROW NIGHT WITH A
SMALL RIDGE TO VALLEY DIFFERENCE BY MORNING...THOUGH READINGS IN
THE VALLEYS WILL FALL INTO THE LOW 30S WITH AREAS OF FROST
FORMING INTO SATURDAY MORNING. FOR THIS REASON A FROST ADVISORY
HAS BEEN HOISTED TONIGHT FOR THE CWA. AFTER A COOL AND CLOUD FREE
DAY ANOTHER COLD NIGHT WILL SET UP SATURDAY NIGHT WITH A LARGER
RIDGE TO VALLEY TEMPERATURE SPLIT. THIS WILL LIKELY RESULT IN
TEMPS DOWN TO THE MID 20S IN THE SHELTERED VALLEYS AND NEAR
FREEZING ON THE RIDGES. THIS WILL ALSO BRING ABOUT WIDESPREAD
FROST AND POTENTIALLY END THE GROWING SEASON...CERTAINLY EXPECT
THAT TO BE THE CASE IN THE VALLEYS. ACCORDINGLY...WILL CONTINUE
THE FREEZE WATCH FOR SATURDAY NIGHT INTO SUNDAY MORNING.
USED THE SHORTBLEND GUIDANCE AS A STARTING POINT FOR T AND TD
GRIDS INTO SATURDAY MORNING WITH THE SUPERBLEND USED THEREAFTER.
DID MAKE SOME SIGNIFICANT CHANGES TO THE T GRIDS TONIGHT AND
SATURDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE TO VALLEY
DIFFERENCES. AS FOR POPS...WENT ZERO THROUGH THE SHORT TERM
PERIOD...IN LINE WITH ALL GUIDANCE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 215 PM EDT FRI OCT 16 2015
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE REGION THROUGH THE
EXTENDED PERIOD OF THE FORECAST WITH RIDGE/VALLEY SPLITS IN
TEMPERATURES. LOOKS LIKE SOME DRY AFTERNOONS SHAPING UP WITH RH`S
UNDER 25 PERCENT EACH DAY THROUGH AT LEAST WEDNESDAY. LOOKS LIKE
FREEZING TEMPERATURES CAN BE EXPECTED AGAIN SUNDAY NIGHT...SO WILL
LIKELY NEED TO CARRY SOME HEADLINES AGAIN SUNDAY NIGHT. AT THIS
POINT...WILL CONTINUE TO FOCUS ON FROST/FREEZE ISSUES IN THE SHORT
TERM. A WEAK FRONT WILL WASH OUT AS IT MOVES INTO THE OHIO RIVER
VALLEY ON THURSDAY...BUT MODELS CONTINUE TO TREND DRIER WITH THIS
FEATURE...SO WILL MAINTAIN A DRY FORECAST THROUGH NEXT FRIDAY.
OTHERWISE...EXPECT SLOWLY WARMING TEMPERATURES THROUGH NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 121 AM EDT SAT OCT 17 2015
HIGH PRESSURE CONTINUES TO BUILD SOUTH ACROSS THE REGION. THIS
COUPLED WITH DRY AIR WILL HELP MAINTAIN VFR CONDITIONS THROUGH
THE TAF PERIOD. DID MAINTAIN THE SCT050 DECK IN THE AFTERNOON GIVEN
A WAVE COMES THROUGH AND SOUNDINGS INDICATE ENOUGH MOISTURE. WINDS
WILL REMAIN LIGHT FOR THE MOST PART...HOWEVER FEW GUSTS OUT OF THE
NORTH AT 10 TO 15 KTS CAN NOT BE RULED OUT WITH DECENT MIXING
BASED ON FORECAST SOUNDINGS GENERALLY AFTER SUNRISE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...DJ
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
121 AM EDT SAT OCT 17 2015
.UPDATE...
ISSUED AT 1040 PM EDT FRI OCT 16 2015
FORECAST REMAINS ON TRACK TONIGHT...SO DID A QUICK REFRESH TO THE
GRIDS. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS.
UPDATE ISSUED AT 745 PM EDT FRI OCT 16 2015
WITH CLEAR SKIES...VALLEY TEMPS ARE DROPPING OFF QUICKLY THIS
EVENING SO NUDGED TEMPS DOWN TO REFLECT THIS TREND. STILL EXPECT
PATCHY FROST TONIGHT WITH LOWS AROUND FREEZING.
OTHERWISE...FORECAST REMAINS ON TRACK. SENT UPDATED GRIDS TO NDFD
AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 220 PM EDT FRI OCT 16 2015
...COLDEST AIR OF THE SEASON THUS FAR ARRIVES THIS WEEKEND...
17Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING INTO THE OHIO
VALLEY. THIS IS BRINGING COOLER AND DRIER AIR INTO EAST KENTUCKY
ON NORTHWEST TO NORTH WINDS OF AROUND 10 MPH WITH GUSTS TO 15
MPH. THE HIGH HAS ALSO CLEARED THE SKIES AND PLENTY OF SUNSHINE IS
SUPPORTING TEMPERATURES IN THE LOWER 60S ATTM WITH DEWPOINTS
MIXING DOWN INTO THE UPPER 20S AND LOWER 30S.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST AS THEY ALL EASE A TIGHTENING TROUGH TO
OUR NORTH...INTO THE GREAT LAKES AND THEN TO EASTERN CANADA.
HEIGHTS WILL FALL THROUGH THE OHIO VALLEY TONIGHT AND SATURDAY AS
THIS TROUGH PASSES...THOUGH ANY ENERGY ASSOCIATED WITH IT WILL
STAY NORTH OF KENTUCKY. GIVEN THE MODEL AGREEMENT HAVE FAVORED THE
HIGHER RESOLUTION HRRR AND NAM12 FOR WEATHER DETAILS...WITH
SPECIAL EMPHASIS ON THE COOP MOS FROM THE GFS FOR POINT BASED LOWS
EACH NIGHT.
SENSIBLE WEATHER WILL BE RATHER QUIET THROUGH THE WEEKEND WITH
THIS MAINLY A TEMPERATURE FORECAST AS EVEN THE CLOUDS WILL BE FEW
AND FAR BETWEEN. HOWEVER...A CANADIAN HIGH PRESSURE SYSTEM IN
PLACE DURING THIS TIME OF YEAR WILL ALSO MEAN CHILLY LOW
TEMPERATURES AND LIKELY FROST. IN FACT...THAT IS EXACTLY WHAT EAST
KENTUCKY IS FACING TONIGHT AND SATURDAY NIGHT. DO EXPECT
TEMPERATURES TO BE MORE UNIFORM TONIGHT THAN TOMORROW NIGHT WITH A
SMALL RIDGE TO VALLEY DIFFERENCE BY MORNING...THOUGH READINGS IN
THE VALLEYS WILL FALL INTO THE LOW 30S WITH AREAS OF FROST
FORMING INTO SATURDAY MORNING. FOR THIS REASON A FROST ADVISORY
HAS BEEN HOISTED TONIGHT FOR THE CWA. AFTER A COOL AND CLOUD FREE
DAY ANOTHER COLD NIGHT WILL SET UP SATURDAY NIGHT WITH A LARGER
RIDGE TO VALLEY TEMPERATURE SPLIT. THIS WILL LIKELY RESULT IN
TEMPS DOWN TO THE MID 20S IN THE SHELTERED VALLEYS AND NEAR
FREEZING ON THE RIDGES. THIS WILL ALSO BRING ABOUT WIDESPREAD
FROST AND POTENTIALLY END THE GROWING SEASON...CERTAINLY EXPECT
THAT TO BE THE CASE IN THE VALLEYS. ACCORDINGLY...WILL CONTINUE
THE FREEZE WATCH FOR SATURDAY NIGHT INTO SUNDAY MORNING.
USED THE SHORTBLEND GUIDANCE AS A STARTING POINT FOR T AND TD
GRIDS INTO SATURDAY MORNING WITH THE SUPERBLEND USED THEREAFTER.
DID MAKE SOME SIGNIFICANT CHANGES TO THE T GRIDS TONIGHT AND
SATURDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE TO VALLEY
DIFFERENCES. AS FOR POPS...WENT ZERO THROUGH THE SHORT TERM
PERIOD...IN LINE WITH ALL GUIDANCE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 215 PM EDT FRI OCT 16 2015
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE REGION THROUGH THE
EXTENDED PERIOD OF THE FORECAST WITH RIDGE/VALLEY SPLITS IN
TEMPERATURES. LOOKS LIKE SOME DRY AFTERNOONS SHAPING UP WITH RH`S
UNDER 25 PERCENT EACH DAY THROUGH AT LEAST WEDNESDAY. LOOKS LIKE
FREEZING TEMPERATURES CAN BE EXPECTED AGAIN SUNDAY NIGHT...SO WILL
LIKELY NEED TO CARRY SOME HEADLINES AGAIN SUNDAY NIGHT. AT THIS
POINT...WILL CONTINUE TO FOCUS ON FROST/FREEZE ISSUES IN THE SHORT
TERM. A WEAK FRONT WILL WASH OUT AS IT MOVES INTO THE OHIO RIVER
VALLEY ON THURSDAY...BUT MODELS CONTINUE TO TREND DRIER WITH THIS
FEATURE...SO WILL MAINTAIN A DRY FORECAST THROUGH NEXT FRIDAY.
OTHERWISE...EXPECT SLOWLY WARMING TEMPERATURES THROUGH NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 121 AM EDT SAT OCT 17 2015
HIGH PRESSURE CONTINUES TO BUILD SOUTH ACROSS THE REGION. THIS
COUPLED WITH DRY AIR WILL HELP MAINTAIN VFR CONDITIONS THROUGH
THE TAF PERIOD. DID MAINTAIN THE SCT050 DECK IN THE AFTERNOON GIVEN
A WAVE COMES THROUGH AND SOUNDINGS INDICATE ENOUGH MOISTURE. WINDS
WILL REMAIN LIGHT FOR THE MOST PART...HOWEVER FEW GUSTS OUT OF THE
NORTH AT 10 TO 15 KTS CAN NOT BE RULED OUT WITH DECENT MIXING
BASED ON FORECAST SOUNDINGS GENERALLY AFTER SUNRISE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
245 AM CDT SAT OCT 17 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 245 AM CDT SAT OCT 17 2015
SATELLITE LOOP SHOWS AREA OF MID CLOUDS HAS BEEN EXPANDING
SOUTHWARD ACROSS EASTERN NEBRASKA AND WESTERN IOWA LIKELY
LIMITING FROST POTENTIAL FOR THE AREA THIS MORNING. RAP 700 RH
ALSO SHOWS THIS TREND THROUGH 15Z. PLAN TO KEEP ADVISORY GOING
FOR NOW BUT MENTION MORE LIMITED EXTENT IN WORDING OF STATEMENT.
LITTLE CHANGE OTHERWISE TO REMAINDER OF THE FORECAST THROUGH
MONDAY WITH WARMING TREND AND DRY CONDITIONS STILL ON TRACK.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 245 AM CDT SAT OCT 17 2015
EXTENDED PERIOD CONTINUES TO SHOW SIGNS OF A MORE ACTIVE PATTERN
AS CLOSED LOW OVER THE FAR SOUTHWEST GRADUALLY OPENS AND PHASES
WITH THE NORTHERN STREAM BY LATE IN THE PERIOD. GOOD MOISTURE
FETCH DEVELOPS ACROSS THE CENTRAL PART OF THE NATION IN ADVANCE
OF THE TROUGH WITH AN INCREASING CHANCE OF SHOWERS FOR THE AREA
DURING THE PERIOD AS THIS SYSTEM DEVELOPS. THE SOUTHERLY FLOW
WILL ALSO HELP TO MAINTAIN ABOVE NORMAL TEMPERATURES DURING THIS
TIME.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1145 PM CDT FRI OCT 16 2015
EXPECT VFR CONDITIONS THROUGH THE PERIOD. THE BKN-OVC MID LEVEL
CLOUDS CURRENTLY OVER KOMA AND KLNK WILL CONTINUE TO PUSH SEWD THE
NEXT FEW HOURS...THEN LOOK FOR SCT MID OR HIGH LEVEL CLOUDS AT ALL
THREE SITES. SOUTHEAST WINDS WILL SLOWLY INCREASE SAT MORNING...
PROBABLY BECOMING A BIT GUSTY DURING THE AFTERNOON FOR KOFK AND
POSSIBLY FOR KLNK.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR IAZ043-055-056-
069-079-080-090-091.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
954 PM PDT FRI OCT 16 2015
.SYNOPSIS...A SUCCESSION OF LOW PRESSURE SYSTEMS WILL BRING SHOWERS
AND THUNDERSTORMS AT TIMES TO MUCH OF THE REGION THROUGH SUNDAY
EVENING. ANOTHER LARGE CIRCULATION IS NOW EXPECTED TO DIVE INTO THE
GREAT BASIN MONDAY AND SETTLE OVER THE MOJAVE DESERT REGION TUESDAY
AND WEDNESDAY BRINGING UNSETTLED WEATHER WITH TEMPERATURES A LITTLE
BELOW NORMAL.
&&
.UPDATE...MADE A COUPLE MORE TWEAKS TO THE PRECIP FORECAST TO
ACCOUNT FOR THE SECOND BAND OF SHOWERS/STORMS MOVING NORTH INTO SAN
BERNARDINO AND MOHAVE COUNTIES AT THIS TIME. THE EXTENT OF THE BAND
IS A BIT FARTHER WEST THAN PREVIOUSLY EXPECTED AND TIMING IS
SLIGHTLY SLOWER. ADJUSTMENTS HAVE BEEN MADE AND UPDATED FORECAST IS
OUT. CELLS WITHIN THIS BAND WERE NOTABLY STRONGER OVER LA PAZ AND
RIVERSIDE COUNTY...BUT DEVELOPMENT HAS DECREASED SLIGHTLY AS IT
ENTERS OUR FORECAST AREA. STILL...STORMS WILL BE VERY EFFICIENT RAIN
PRODUCERS AND WILL BE MONITORED CLOSELY FOR FLASH FLOODING.
&&
.PREV UPDATE...748 PM PDT FRI OCT 16 2015...SHOWERS AND ISOLATED
THUNDERSTORMS CONTINUE TO DEVELOP AND MOVE NORTH ACROSS THE REGION
THIS EVENING. TWO MAIN EAST-WEST BANDS OF CONCERN AT THIS TIME.
THE FIRST STRETCHES FROM NEAR BAKER CA EAST TOWARD FLAGSTAFF.
HEAVIER CELLS WITHIN THIS BAND HAVE HAD RAIN RATES OF AROUND 1.00"
PER HOUR...BUT WITH RELATIVELY QUICK STORM MOTION AND A LACK OF
SIGNIFICANT TRAINING THEY`VE ONLY MANAGED AROUND 0.25" OF TOTAL
RAINFALL AS THEY PASS. THIS BAND WILL CONTINUE TO MOVE NORTH INTO
SOUTHERN NEVADA...LIKELY DECREASING IN STRENGTH AS IT ENCOUNTERS
MORE STABLE AIR. STILL..THE LAS VEGAS AREA COULD SEE A FEW SHOWERS
OR ISOLATED THUNDERSTORMS BETWEEN ROUGHLY 830 AND 11 THIS EVENING.
THE SECOND BAND IS IN THE DEVELOPMENT STAGE OVER LA PAZ COUNTY. THIS
BAND IS LIKELY TO PUSH NORTH-NORTHWEST INTO MOHAVE AND EASTERN SAN
BERNARDINO COUNTIES OVER THE NEXT 2-4 HOURS. THERE IS FAIRLY GOOD
CLUSTERING OF MODELS SOLUTIONS INDICATING THAT THIS FEATURE WILL
PUSH INTO CLARK AND NORTHERN MOHAVE COUNTIES DURING THE EARLY
MORNING HOURS...THEN CONTINUING NORTH THROUGH THE REMAINDER OF THE
MORNING. SHORT RANGE RAP GUIDANCE INDICATES INCREASING LOW LEVEL
MOISTURE WITH THIS BAND...WHICH COULD RESULT IN MORE EFFICIENT RAIN
PRODUCTION AND HIGHER RAIN RATES. MODEST INSTABILITY WILL CONTINUE
TO ALLOW EMBEDDED THUNDERSTORMS TO DEVELOP IN THIS SECOND
BAND...MOST NOTABLY ALONG THE COLORADO RIVER VALLEY.
THE SHORT RANGE FORECAST HAS BEEN UPDATED TO REFLECT THE LATEST
TRENDS AND SHORT RANGE GUIDANCE. WILL CONTINUE TO MONITOR AND UPDATE
AS NEEDED.
ANOTHER ISSUE THAT WILL BE ADDRESSED OVERNIGHT IS THE POTENTIAL FOR
YET ANOTHER WAVE DIGGING SOUTH INTO THE REGION AND CONTINUING THE
WIDESPREAD SHOWER/THUNDERSTORM ACTIVITY INTO TUESDAY AND WEDNESDAY.
&&
.AVIATION...FOR MCCARRAN...SCATTERED SHOWERS CONTINUE TO DRIFT
ACROSS THE REGION. THE NEXT BATCH MAY IMPACT THE LAS VEGAS VALLEY
BETWEEN 300Z-600Z...WITH CIGS GENERALLY REMAINING ABOVE 6-8K FEET.
ISOLATED THUNDERSTORMS CANNOT BE RULED OUT. ADDITIONAL ROUNDS OF
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AFTER MIDNIGHT AND INTO
SATURDAY MORNING. CIGS COULD DROP TO 4-6K FEET WITH THESE STORMS.
WINDS ARE EXPECTED TO TREND TOWARD TYPICAL DIURNAL DIRECTIONS AT 8
KTS OR LESS BUT WILL GUST TO AROUND 20-25 KTS FROM VARYING
DIRECTIONS IN THE VICINITY OF STORMS. THE CHANCE FOR SHRA/TSRA WILL
CONTINUE THROUGH EARLY NEXT WEEK WITH SUNDAY AFTERNOON SEEING THE
MOST COVERAGE. CIGS/VSBYS REDUCED TO MVFR OR LOWER AT TIMES AS WELL
AS OCCASIONAL MOUNTAIN OBSCURATIONS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SHRA/TSRA ARE POSSIBLE THROUGH TONIGHT WITH THE MOST
COVERAGE ACROSS MOHAVE COUNTY. SHOWERS AND THUNDERSTORMS WILL BE
FAVORED OVER CLARK...LINCOLN AND MOHAVE COUNTIES ON SATURDAY. CIGS
WILL MAINLY BE 6K-10K FEET IN AND NEAR SHRA/TSRA OTHERWISE 10K-14K
FEET. VSBY MAY BE REDUCED TO MVFR OR LOWER WITH GUSTY AND ERRATIC
WINDS POSSIBLE IN AND NEAR ANY SHRA/TSRA. OTHERWISE EXPECT WINDS TO
TREND TOWARD TYPICAL DIURNAL DIRECTIONS AT 10 KTS OR LESS. MOUNTAIN
OBSCURATIONS ARE POSSIBLE. SHRA/TSRA ARE EXPECTED ONCE AGAIN ON
SUNDAY...WITH THE MOST COVERAGE EXPECTED ACROSS NYE, CLARK, LINCOLN
AND MOHAVE COUNTIES. CIGS/VSBY REDUCED TO MVFR OR LOWER AS WELL AS
MOUNTAIN OBSCURATIONS POSSIBLE.
&&
.PREV DISCUSSION...
320 PM PDT FRI OCT 16 2015
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT.
THE INGREDIENTS REMAIN IN PLACE FOR PERIODS OF SHOWERS AND EMBEDDED
THUNDERSTORMS TO DEVELOP OVER MUCH OF THE THE FORECAST AREA TONIGHT
THROUGH SUNDAY. LIGHT TO MODERATE SHOWERS WILL BE COMMON FOR MOST
AREAS. ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES OF 1.0-1.4 INCHES
WILL LEAD TO RAINFALL RATES OVER 1 INCH PER HOUR WITH SOME
THUNDERSTORMS. THE DIFFICULTY LIES IN PINNING DOWN WHEN SPECIFIC
AREAS WILL SEE SIGNIFICANT RAINFALL. THE FLASH FLOOD WATCH FOR
SOUTHERN NEVADA AND SURROUNDING ZONES IN NORTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA WILL REMAIN IN EFFECT THROUGH SUNDAY EVENING TO
HIGHLIGHT THIS POTENTIAL.
THE MODELS ARE IN GOOD GENERAL AGREEMENT WITH THE EVOLUTION OF THE
PATTERN THROUGH SUNDAY. THE TWO MAIN FEATURES THAT WILL DRIVE THE
WEATHER ARE THE UPPER LOW CURRENTLY OVER CENTRAL CALIFORNIA AND AN
EASTERN PACIFIC TROUGH WITH ITS BASE NEAR 35N/135W. THE CENTRAL
CALIFORNIA LOW IS FORECAST TO TRANSITION FROM A CLOSED CIRCULATION
TO AN OPEN SYSTEM TONIGHT AND BEGIN HEADING EAST IN RESPONSE TO THE
PACIFIC TROUGH. THIS WILL PRODUCE INCREASING UPWARD FORCING ACROSS
MOHAVE...CLARK AND LINCOLN COUNTIES LATE TONIGHT THROUGH SATURDAY
MORNING LEADING TO MORE EXTENSIVE SHOWERS AND EMBEDDED
THUNDERSTORMS. AS THE TROUGH AXIS PASSES SATURDAY AFTERNOON AND
EVENING...WE SHOULD SEE SHOWER COVERAGE DIMINISH.
THE NEXT TROUGH WILL THEN BEGIN TO EXERT ITS INFLUENCE EARLY SUNDAY
MORNING WITH A 50-60 KNOT CURVED JET MOVING OVER SOUTHERN
CALIFORNIA/NEVADA PRECEDING THE BASE OF THE TROUGH. BROAD UPWARD
FORCING WILL ACT ON SUBSTANTIAL LOW AND MID LEVEL MOISTURE LINGERING
OVER SOUTHERN NEVADA AND NORTHWEST ARIZONA TO PRODUCE THE MOST
EXTENSIVE PRECIPITATION COVERAGE OF THE WEEKEND. CONSIDERABLE SHEAR
WILL SUPPORT MORE ORGANIZED STORMS SUNDAY MOVING FROM SOUTHWEST TO
NORTHEAST. THE BROAD ENERGETIC TROUGH WILL SUPPORT SHOWERS AND
ISOLATED THUNDERSTORMS MUCH OF SUNDAY NIGHT THEN A DECREASE IN
COVERAGE FROM WEST TO EAST EARLY MONDAY MORNING. SNOW LEVELS WILL
ONLY LOWER TO AROUND 10000 FEET SUNDAY AFTERNOON AND NIGHT SO ONLY
THE HIGH PEAKS OF THE SOUTHERN SIERRA...WHITE MOUNTAINS AND SPRING
MOUNTAINS WILL SEE SOME SNOW. TEMPS WERE LOWERED A FEW DEGREE BASED
ON THE LATEST GUIDANCE WITH HIGHS RUNNING SEVERAL DEGREES BELOW
NORMAL.
.LONG TERM...MONDAY THROUGH FRIDAY.
THE 12Z MEDIUM RANGE MODELS ARE ALL IN QUITE GOOD AGREEMENT THAT
ANOTHER SHORTWAVE TROUGH APPROACHING THE PACIFIC NORTHWEST MONDAY
MORNING WILL DIVE INTO THE MEAN TROUGH LINGERING OVER NEVADA. THIS
ADDITIONAL SHOT OF ENERGY WILL SPIN IT UP INTO A CLOSED LOW CENTERED
OVER THE LOWER COLORADO RIVER VALLEY ALONG THE CALIFORNIA/ARIZONA
BORDER WHICH WILL BE NEARLY STATIONARY TUESDAY AND WEDNESDAY. THIS
WILL KEEP COOLER CONDITIONS AROUND THROUGH AT LEAST MID WEEK ALONG
WITH A CHANCE OF SHOWERS CONTINUING OVER NORTHWEST ARIZONA AND THE
COLORADO RIVER VALLEY AT THE LEAST. IT IS FORECAST TO SLOWLY PULL
AWAY THURSDAY LEAVING A DRY NORTHWEST FLOW IN ITS WAKE. THE LATEST
ECMWF INDICATES ANOTHER DEEP TROUGH DIVING INTO THE SOUTHWEST FRIDAY
INTO NEXT WEEKEND. IT COULD BE ANOTHER ACTIVE WEEKEND OF WEATHER.
&&
.CLIMATE...RECORD HIGH MINIMUM TEMPERATURES ARE ALSO POSSIBLE FOR
LAS VEGAS TODAY AND SATURDAY.
DATE VALUE/YEAR
-----------------------------
10/16 66/2010*
10/17 67/1991
* TIE FROM PREVIOUS YEARS.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE REQUIRED
THROUGH MONDAY.
&&
$$
UPDATE/AVIATION...WOLCOTT
PREV DISCUSSION...ADAIR
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
413 AM EDT SAT OCT 17 2015
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL PRODUCE MUCH BELOW
NORMAL TEMPERATURES ALONG WITH SCATTERED RAIN AND SNOW SHOWERS. SNOW
ACCUMULATIONS OF A DUSTING TO 3 INCHES IS EXPECTED ABOVE 1500
FEET. TEMPERATURES WILL HOLD MAINLY IN THE 30S MOUNTAINS AND 40S
VALLEYS TODAY WITH LOWS IN THE 20S TO MID 30S TONIGHT. SOME AREAS
OF FROST ARE LIKELY IN THE CHAMPLAIN VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 345 AM EDT SATURDAY...WATER VAPOR SHOWS A DEEP MID/UPPER
LEVEL TROUGH OF LOW PRESSURE ACROSS THE NORTHEAST UNITED STATES.
SEVERAL DISTURBANCES IN THE FLOW ALOFT WILL CONTINUE TO IMPACT OUR
REGION THROUGH SUNDAY...WITH AREAS OF RAIN AND SNOW SHOWERS. AS
SURFACE LOW PRESSURE TRACKS INTO NORTHERN MAINE TODAY...EXPECT
WINDS TO SHIFT TO THE NORTHWEST BY 15Z...WHICH WILL HELP REFOCUS
PRECIPITATION ACROSS THE UPSLOPE REGIONS OF THE NORTHERN DACKS AND
CENTRAL/NORTHERN GREEN MOUNTAINS. THE NAM12/BTV 4KM AND HRRR SHOW
FAVORABLE MOISTURE AND WIND DIRECTION FOR TERRAIN DRIVEN UPSLOPE
PRECIPITATION FROM 12Z THROUGH 18Z TODAY. HOWEVER...SOUNDINGS SHOW
DEPTH OF 925MB TO 700MB MOISTURE DECREASES BY 21Z TODAY...AS
NORTHWEST WINDS ADVECT DRIER AIR INTO THE REGION. THIS WILL
DECREASE AREAL COVERAGE OF UPSLOPE PRECIPITATION BY EVENING...WITH
JUST FLURRIES POSSIBLE OVERNIGHT TONIGHT. QPF AMOUNTS VARY GREATLY
DEPENDING UPON THE MODEL WITH LATEST 00Z BTV 4KM SHOWING 0.60 ALL
SNOW AT JAY PEAK WHILE GFS HAS AROUND 0.35...AND THE NAM12 IS ONLY
0.10. GIVEN TRACK OF SURFACE LOW PRESSURE NORTH OF OUR CWA AND
LACK OF ATLANTIC MOISTURE ADVECTING INTO THE SYSTEM WITH NO CLOSED
UPPER LEVELS...THINKING QPF WILL BE ON THE LIGHTER SIDE. AMOUNTS
WILL RANGE FROM A TRACE TO COUPLE HUNDRETHS IN THE VALLEY TO A
0.25 OR SO FROM MOUNT MANSFIELD TO JAY PEAK...AND SIMILAR ACROSS
THE NORTHERN DACKS. AT 12Z THIS MORNING THERMAL PROFILES SHOW SNOW
LEVELS AROUND 1800 FEET ACROSS THE DACKS AND NEAR 2200 FEET IN
THE CENTRAL GREENS...BUT WITH STRONG LOW LEVEL COLD AIR ADVECTION
ON BRISK NORTHWEST WINDS...THERMAL PROFILES CONTINUE TO
COOL...WITH SNOW LEVELS DROPPING AROUND 1500 FEET BY MIDDAY.
BOUNDARY LAYER TEMPS BETWEEN 3 AND 4C AND LACK OF SIGNIFICANT
MOISTURE IN THE CHAMPLAIN VALLEY WILL LIMIT SNOW ACCUMULATION...MAYBE
A FEW WET SNOW FLAKES WITH THE HEAVIER SHOWERS. THINKING
ACCUMULATIONS WILL RANGE FROM 2 TO 4 INCHES SUMMITS OF THE DACKS
AND THE NORTHERN GREEN MOUNTAINS FROM JAY PEAK TO SUGARBUSH TO A
DUSTING TO 2 INCHES HIGHER MOUNTAIN VALLEYS ABOVE 1500 FEET. TEMPS
WILL RANGE FROM THE MID/UPPER 20S SUMMITS TO LOWER/MID 40S
CHAMPLAIN VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 345 AM EDT SATURDAY...FORECAST CONCERN TONIGHT WILL BE
TEMPERATURES AND POTENTIAL FOR FREEZE IN THE CHAMPLAIN VALLEY
WHERE THE GROWING SEASON CONTINUES. HAVE NOTED ON SOUNDING STRONG
BOUNDARY LAYER MIXING WITH WINDS OF 5 TO 10 KNOTS EXPECTED AS
REGION IS UNDER LOW LEVEL COLD AIR ADVECTION ON NORTHWEST FLOW.
ALSO...WITH DEEP MID/UPPER LEVEL TROUGH...COLD AIR ALOFT..AND WARM
LAKE CHAMPLAIN WATER...EXPECT SOME CLOUDS ACROSS THE CHAMPLAIN
VALLEY...HOLDING TEMPERATURES IN THE UPPER 20S TO MID 30SNEAR THE
LAKE. GIVEN THE CONDITIONS ABOVE...NOT THINKING A FROST WILL
DEVELOP...BUT MORE ALONG THE LINES OF A FREEZE...BUT WILL LET DAY
SHIFT DECIDE ON ANY POTENTIAL HEADLINES. ELSEWHERE...TEMPERATURES
WILL RANGE FROM THE UPPER TEENS MOUNTAIN SUMMITS TO MID 20S SAINT
LAWRENCE VALLEY AND PARTS OF CENTRAL VT. A FEW LEFTOVER MOUNTAIN
FLURRIES WILL BE POSSIBLE...BUT MOISTURE PROGGES ARE VERY DRY SO
ANY PRECIPITATION WILL BE LIGHT.
SUNDAY WILL FEATURE MID/UPPER LEVEL TROF WITH THE CORE OF THE
COLDEST AIR DIRECTLY OVERHEAD. THIS WILL RESULT IN THE COLDEST DAY
OF WEEKEND...WITH PROGGED 850MB TEMPERATURES BETWEEN -8C AND -10C.
THESE PROFILES WITH BRISK NORTHWEST WINDS OF 10 TO 20 KNOTS WILL
RESULT IN HIGHS ONLY IN THE UPPER 20S TO LOWER 30S MOUNTAIN TOWNS TO
NEAR 40F CHAMPLAIN AND SAINT LAWRENCE VALLEYS. SOUNDINGS SHOW VERY
STEEP LOW LEVEL LAPSE RATES OVER THE MOUNTAINS WITH SOME AVAILABLE
MOISTURE BETWEEN 900MB AND 700MB. THIS INSTABILITY...MOISTURE...AND
UPSLOPE FLOW SHOULD BE ENOUGH TO SUPPORT CONVECTIVE TYPE SNOW
SHOWERS...ESPECIALLY IN THE MOUNTAINS. GIVEN THESE INGREDIENTS WILL
MENTION HIGH CHANCE POPS IN THE MOUNTAINS AND SLIGHT CHANCE IN THE
VALLEYS FOR SUNDAY AFTERNOON...WITH A QUICK DUSTING TO 1 INCH
POSSIBLE IN THE HEAVIER CONVECTIVE ELEMENTS OVER THE MOUNTAINS.
SUNDAY NIGHT WILL BE THE COLDEST NIGHT OF THE SEASON FOR ALL
LOCATIONS ACROSS THE NORTH COUNTRY. 1030MB HIGH PRESSURE AXIS WILL
BE DIRECTLY OVERHEAD WITH PROGGED 850MB TEMPS NEAR -10C. THIS WILL
RESULT IN CLEAR SKIES AND LIGHT WINDS WITH TEMPERATURES RANGING FROM
NEAR 10F SLK/COLDER VALLEYS OF THE NORTHEAST KINGDOM TO MID/UPPER
TEENS MOUNTAIN TOWNS TO LOWER/MID 20S CHAMPLAIN/SAINT LAWRENCE
VALLEYS. A WIDESPREAD FROST IS EXPECTED ON SUNDAY NIGHT/MONDAY
MORNING ACROSS THE ENTIRE CHAMPLAIN VALLEY.
TEMPERATURES WILL REBOUND QUICKLY ON MONDAY WITH DEVELOPING
SOUTHWEST FLOW AND WARM AIR ADVECTION. PROGGED 850MB TEMPS WARM TO
NEAR 0C BY 00Z TUESDAY...PRODUCING HIGHS BACK INTO THE UPPER 30S
MOUNTAINS TO UPPER 40S WARMER VALLEYS. DRY CONDITIONS WILL PREVAIL
WITH BUILDING RIDGE ALOFT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 410 AM EDT SATURDAY...DEEP SOUTHWESTERLY FLOW PREVAILS ACROSS
NORTH COUNTRY MONDAY NIGHT IN ADVANCE OF SHORTWAVE AND ASSOCIATED
COLD FRONT APPROACHING FROM THE NORTHERN GREAT LAKES REGION.
EXPECT INCREASING CLOUDS OVERNIGHT WITH A CHANCE OF SHOWERS AFTER
MIDNIGHT...MAINLY ACROSS NORTHERN AREAS. CHANCE OF SHOWERS
AREAWIDE ON TUESDAY AS THE SHORTWAVE PASSES TO OUR NORTH AND COLD
FRONT WEAKENS WHILE DEPRESSING SOUTH ACROSS FORECAST AREA. DRIER
CONDITIONS FOR TUESDAY NIGHT INTO WEDNESDAY AS HIGH PRESSURE
ATTEMPTS TO BUILD BACK INTO THE REGION FROM THE NORTH. GFS AND
ECMWF THEN GO THEIR SEPARATE WAYS FOR LATER IN THE WEEK. GFS
MAINTAINS HIGH PRESSURE OVER THE AREA FOR MOST OF THE PERIOD WHILE
ECMWF CONTINUES TO SUGGEST THAT A DISTURBANCE WILL DEEPEN WHILE
MOVING SOUTHEAST FROM ONTARIO. HAVE STAYED CLOSE TO OUR EARLIER
FORECAST WHICH INCLUDED CHANCE OF SHOWERS WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...ALTHOUGH THIS FORECAST CONTAINS A HIGH DEGREE OF
UNCERTAINTY. DRIER CONDITIONS THEN EXPECTED FOR FRIDAY WHICH BOTH
GFS AND ECMWF SUGGEST WOULD CONTINUE INTO NEXT WEEKEND. MAX
TEMPERATURES EACH DAY MOSTLY IN THE 50S IN THE VALLEYS...WITHIN A
FEW DEGREES OF NORMAL.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY....AS TROUGH OF LOW PRESSURE MOVES INTO THE
REGION IT WILL BRING LIGHT RAIN SHOWERS TO THE AREA OVERNIGHT WITH
OCNL MVFR CEILINGS. ALSO...TEMPERATURE PROFILES COOL SUFFICIENTLY
FOR A CHANGE TO SNOW SHOWERS AT SLK BETWEEN 08-12Z. COULD SEE
OCCASIONAL IFR CONDITIONS AT SLK DURING SNOW SHOWERS BTWN 10-18Z.
WINDS BECOMING SOUTHWEST 5-10KTS OVERNIGHT THEN WEST TO NORTHWEST
10-15KTS WITH GUSTS 20-22KTS DURING SATURDAY.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
ISOLD TO SCATTERED RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS ARE
EXPECTED INTO THE FIRST HALF OF SUNDAY. MAINLY VFR CONDITIONS IN
THE VALLEYS WITH OCNL MVFR AND BRIEF IFR POSSIBLE AT MPV/SLK IN
ANY SNOW SHOWERS. THEREAFTER...SURFACE HIGH PRESSURE BUILDS IN
FROM THE WEST AND BECOMES REESTABLISHED OVER THE AREA WITH MAINLY
VFR CONDITIONS EXPECTED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
343 AM EDT SAT OCT 17 2015
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL PRODUCE MUCH BELOW
NORMAL TEMPERATURES ALONG WITH SCATTERED RAIN AND SNOW SHOWERS. SNOW
ACCUMULATIONS OF A DUSTING TO 3 INCHES IS EXPECTED ABOVE 1500
FEET. TEMPERATURES WILL HOLD MAINLY IN THE 30S MOUNTAINS AND 40S
VALLEYS TODAY WITH LOWS IN THE 20S TO MID 30S TONIGHT. SOME AREAS
OF FROST ARE LIKELY IN THE CHAMPLAIN VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 345 AM EDT SATURDAY...WATER VAPOR SHOWS A DEEP MID/UPPER
LEVEL TROUGH OF LOW PRESSURE ACROSS THE NORTHEAST UNITED STATES.
SEVERAL DISTURBANCES IN THE FLOW ALOFT WILL CONTINUE TO IMPACT OUR
REGION THROUGH SUNDAY...WITH AREAS OF RAIN AND SNOW SHOWERS. AS
SURFACE LOW PRESSURE TRACKS INTO NORTHERN MAINE TODAY...EXPECT
WINDS TO SHIFT TO THE NORTHWEST BY 15Z...WHICH WILL HELP REFOCUS
PRECIPITATION ACROSS THE UPSLOPE REGIONS OF THE NORTHERN DACKS AND
CENTRAL/NORTHERN GREEN MOUNTAINS. THE NAM12/BTV 4KM AND HRRR SHOW
FAVORABLE MOISTURE AND WIND DIRECTION FOR TERRAIN DRIVEN UPSLOPE
PRECIPITATION FROM 12Z THROUGH 18Z TODAY. HOWEVER...SOUNDINGS SHOW
DEPTH OF 925MB TO 700MB MOISTURE DECREASES BY 21Z TODAY...AS
NORTHWEST WINDS ADVECT DRIER AIR INTO THE REGION. THIS WILL
DECREASE AREAL COVERAGE OF UPSLOPE PRECIPITATION BY EVENING...WITH
JUST FLURRIES POSSIBLE OVERNIGHT TONIGHT. QPF AMOUNTS VARY GREATLY
DEPENDING UPON THE MODEL WITH LATEST 00Z BTV 4KM SHOWING 0.60 ALL
SNOW AT JAY PEAK WHILE GFS HAS AROUND 0.35...AND THE NAM12 IS ONLY
0.10. GIVEN TRACK OF SURFACE LOW PRESSURE NORTH OF OUR CWA AND
LACK OF ATLANTIC MOISTURE ADVECTING INTO THE SYSTEM WITH NO CLOSED
UPPER LEVELS...THINKING QPF WILL BE ON THE LIGHTER SIDE. AMOUNTS
WILL RANGE FROM A TRACE TO COUPLE HUNDRETHS IN THE VALLEY TO A
0.25 OR SO FROM MOUNT MANSFIELD TO JAY PEAK...AND SIMILAR ACROSS
THE NORTHERN DACKS. AT 12Z THIS MORNING THERMAL PROFILES SHOW SNOW
LEVELS AROUND 1800 FEET ACROSS THE DACKS AND NEAR 2200 FEET IN
THE CENTRAL GREENS...BUT WITH STRONG LOW LEVEL COLD AIR ADVECTION
ON BRISK NORTHWEST WINDS...THERMAL PROFILES CONTINUE TO
COOL...WITH SNOW LEVELS DROPPING AROUND 1500 FEET BY MIDDAY.
BOUNDARY LAYER TEMPS BETWEEN 3 AND 4C AND LACK OF SIGNIFICANT
MOISTURE IN THE CHAMPLAIN VALLEY WILL LIMIT SNOW ACCUMULATION...MAYBE
A FEW WET SNOW FLAKES WITH THE HEAVIER SHOWERS. THINKING
ACCUMULATIONS WILL RANGE FROM 2 TO 4 INCHES SUMMITS OF THE DACKS
AND THE NORTHERN GREEN MOUNTAINS FROM JAY PEAK TO SUGARBUSH TO A
DUSTING TO 2 INCHES HIGHER MOUNTAIN VALLEYS ABOVE 1500 FEET. TEMPS
WILL RANGE FROM THE MID/UPPER 20S SUMMITS TO LOWER/MID 40S
CHAMPLAIN VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 345 AM EDT SATURDAY...FORECAST CONCERN TONIGHT WILL BE
TEMPERATURES AND POTENTIAL FOR FREEZE IN THE CHAMPLAIN VALLEY
WHERE THE GROWING SEASON CONTINUES. HAVE NOTED ON SOUNDING STRONG
BOUNDARY LAYER MIXING WITH WINDS OF 5 TO 10 KNOTS EXPECTED AS
REGION IS UNDER LOW LEVEL COLD AIR ADVECTION ON NORTHWEST FLOW.
ALSO...WITH DEEP MID/UPPER LEVEL TROUGH...COLD AIR ALOFT..AND WARM
LAKE CHAMPLAIN WATER...EXPECT SOME CLOUDS ACROSS THE CHAMPLAIN
VALLEY...HOLDING TEMPERATURES IN THE UPPER 20S TO MID 30SNEAR THE
LAKE. GIVEN THE CONDITIONS ABOVE...NOT THINKING A FROST WILL
DEVELOP...BUT MORE ALONG THE LINES OF A FREEZE...BUT WILL LET DAY
SHIFT DECIDE ON ANY POTENTIAL HEADLINES. ELSEWHERE...TEMPERATURES
WILL RANGE FROM THE UPPER TEENS MOUNTAIN SUMMITS TO MID 20S SAINT
LAWRENCE VALLEY AND PARTS OF CENTRAL VT. A FEW LEFTOVER MOUNTAIN
FLURRIES WILL BE POSSIBLE...BUT MOISTURE PROGGES ARE VERY DRY SO
ANY PRECIPITATION WILL BE LIGHT.
SUNDAY WILL FEATURE MID/UPPER LEVEL TROF WITH THE CORE OF THE
COLDEST AIR DIRECTLY OVERHEAD. THIS WILL RESULT IN THE COLDEST DAY
OF WEEKEND...WITH PROGGED 850MB TEMPERATURES BETWEEN -8C AND -10C.
THESE PROFILES WITH BRISK NORTHWEST WINDS OF 10 TO 20 KNOTS WILL
RESULT IN HIGHS ONLY IN THE UPPER 20S TO LOWER 30S MOUNTAIN TOWNS TO
NEAR 40F CHAMPLAIN AND SAINT LAWRENCE VALLEYS. SOUNDINGS SHOW VERY
STEEP LOW LEVEL LAPSE RATES OVER THE MOUNTAINS WITH SOME AVAILABLE
MOISTURE BETWEEN 900MB AND 700MB. THIS INSTABILITY...MOISTURE...AND
UPSLOPE FLOW SHOULD BE ENOUGH TO SUPPORT CONVECTIVE TYPE SNOW
SHOWERS...ESPECIALLY IN THE MOUNTAINS. GIVEN THESE INGREDIENTS WILL
MENTION HIGH CHANCE POPS IN THE MOUNTAINS AND SLIGHT CHANCE IN THE
VALLEYS FOR SUNDAY AFTERNOON...WITH A QUICK DUSTING TO 1 INCH
POSSIBLE IN THE HEAVIER CONVECTIVE ELEMENTS OVER THE MOUNTAINS.
SUNDAY NIGHT WILL BE THE COLDEST NIGHT OF THE SEASON FOR ALL
LOCATIONS ACROSS THE NORTH COUNTRY. 1030MB HIGH PRESSURE AXIS WILL
BE DIRECTLY OVERHEAD WITH PROGGED 850MB TEMPS NEAR -10C. THIS WILL
RESULT IN CLEAR SKIES AND LIGHT WINDS WITH TEMPERATURES RANGING FROM
NEAR 10F SLK/COLDER VALLEYS OF THE NORTHEAST KINGDOM TO MID/UPPER
TEENS MOUNTAIN TOWNS TO LOWER/MID 20S CHAMPLAIN/SAINT LAWRENCE
VALLEYS. A WIDESPREAD FROST IS EXPECTED ON SUNDAY NIGHT/MONDAY
MORNING ACROSS THE ENTIRE CHAMPLAIN VALLEY.
TEMPERATURES WILL REBOUND QUICKLY ON MONDAY WITH DEVELOPING
SOUTHWEST FLOW AND WARM AIR ADVECTION. PROGGED 850MB TEMPS WARM TO
NEAR 0C BY 00Z TUESDAY...PRODUCING HIGHS BACK INTO THE UPPER 30S
MOUNTAINS TO UPPER 40S WARMER VALLEYS. DRY CONDITIONS WILL PREVAIL
WITH BUILDING RIDGE ALOFT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 343 PM EDT FRIDAY...RELATIVELY QUIET WEATHER PATTERN
ANTICIPATED FOR THE EXTENDED FORECAST PERIOD...WITH MODERATING
TEMPERATURES. MID-LEVEL TROUGH AXIS WILL SHIFT EAST OF NEW ENGLAND
ON MONDAY WITH SURFACE RIDGE AXIS BUILDING EASTWARD INTO THE NERN
CONUS. THIS SYSTEM WILL BRING PLEASANT CONDITIONS AND SOME
POTENTIAL FOR AT LEAST PARTLY SUNNY CONDITIONS ON MONDAY. THE 12Z
GFS SUGGESTS RIDGE AXIS WILL SHIFT EAST OF VERMONT BY MONDAY
AFTN...ALLOWING FOR DEVELOPMENT OF S-SW RETURN FLOW. AFTER A
CHILLY MORNING MONDAY...THIS SHOULD ALLOW TEMPERATURES TO MODERATE
INTO THE 44-48F RANGE BY MID AFTN. A WEAK FRONTAL ZONE SAGGING
SEWD FROM ONTARIO MAY BRING A FEW RAIN SHOWERS MONDAY NIGHT INTO
EARLY TUESDAY...FOLLOWED BY A WEAK RIDGE IN PLACE TUESDAY NIGHT
INTO WEDNESDAY. SHOULD SEE HIGH TEMPERATURES BACK INTO THE LOW TO
MID 50S FOR TUESDAY AND WEDNESDAY. NEXT TROUGH AXIS IN WNWLY FLOW
WILL BRING CHANCES FOR RAIN SHOWERS WEDNESDAY NIGHT INTO THURSDAY
(POPS 30-50% RANGE). A STRONGER MID-UPPER LEVEL RIDGE IS
ANTICIPATED LATE IN THE WEEK...AND COULD BRING A MORE SIGNIFICANT
WARMING/DRYING TREND FRIDAY/SATURDAY.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY....AS TROUGH OF LOW PRESSURE MOVES INTO THE
REGION IT WILL BRING LIGHT RAIN SHOWERS TO THE AREA OVERNIGHT WITH
OCNL MVFR CEILINGS. ALSO...TEMPERATURE PROFILES COOL SUFFICIENTLY
FOR A CHANGE TO SNOW SHOWERS AT SLK BETWEEN 08-12Z. COULD SEE
OCCASIONAL IFR CONDITIONS AT SLK DURING SNOW SHOWERS BTWN 10-18Z.
WINDS BECOMING SOUTHWEST 5-10KTS OVERNIGHT THEN WEST TO NORTHWEST
10-15KTS WITH GUSTS 20-22KTS DURING SATURDAY.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
ISOLD TO SCATTERED RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS ARE
EXPECTED INTO THE FIRST HALF OF SUNDAY. MAINLY VFR CONDITIONS IN
THE VALLEYS WITH OCNL MVFR AND BRIEF IFR POSSIBLE AT MPV/SLK IN
ANY SNOW SHOWERS. THEREAFTER...SURFACE HIGH PRESSURE BUILDS IN
FROM THE WEST AND BECOMES REESTABLISHED OVER THE AREA WITH MAINLY
VFR CONDITIONS EXPECTED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...BANACOS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
905 AM MST SAT OCT 17 2015
&&
.SYNOPSIS...
A SERIES OF SLOW MOVING LOW PRESSURE SYSTEMS WILL BRING ELEVATED
CHANCES OF SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH THE MIDDLE
OF NEXT WEEK. SHOWERS AND STORMS ARE POSSIBLE AGAIN TODAY AND
SUNDAY WITH A SLIGHT DRYING TREND ON MONDAY. THIS WILL BE SHORT
LIVED HOWEVER AS A SECOND LOW MOVES INTO THE DESERT SOUTHWEST ON
TUESDAY AND REMAINS IN PLACE THROUGH THURSDAY. DRIER AIR WILL MOVE
INTO THE AREA LATE NEXT WEEK.
&&
.DISCUSSION... A WEAK SHORTWAVE...WHICH IS THE REMAINS OF THE UPPER
LOW CENTER THAT BROUGHT LOCALLY HEAVY RAIN TO PARTS OF SOUTHERN CA
OVER THE LAST FEW DAYS...CAN BE SEEN ON SATELLITE IMAGERY MOVING
EASTWARD ACROSS SOUTHWEST ARIZONA. THIS SHORTWAVE CURRENTLY IS
TRIGGERING ISOLATED-SCATTERED SHOWER/THUNDERSTORM ACTIVITY ACROSS LA
PAZ AND EASTERN YUMA COUNTIES. THE LATEST HRRR HIGH-RES MODEL RUN IS
NOW SHOWING THAT THE SHOWER/THUNDERSTORM ACTIVITY WILL LIKELY
DIMINISH SOMEWHAT AS WE GO THROUGH THE LATE MORNING HOURS...BUT
REDEVELOP THIS AFTERNOON FARTHER TO THE EAST...OVER SOUTH-CENTRAL AZ
AS THE AFOREMENTIONED SHORTWAVE MOVES INTO THAT REGION AND OUTFLOWS
FROM STORMS OVER SE AZ MOVES INTO THAT REGION. HOWEVER...IT STILL
APPEARS THAT THE CONVECTIVE ACTIVITY THIS AFTERNOON WILL BE MUCH
LESS INTENSE/WIDESPREAD THEN WHAT WE SAW YESTERDAY...DUE TO LESS
AVAILABLE MOISTURE AND INSTABILITY...BUT THERE STILL COULD A FEW
STRONGER CELLS THIS AFTERNOON...WHICH COULD PRODUCE BRIEF HEAVY
DOWNPOURS AND LOCALLY GUSTY WINDS. AS FAR AS THE VERY SHORT-TERM
FORECAST IS CONCERNED...OTHER THAN RAISING POPS INTO THE SLIGHT
CHANCE RANGE OVER SW AZ...INHERITED GRIDDED AND ZONE FORECASTS ARE
HOLDING UP WELL.
&&
.PREVIOUS DISCUSSION... EARLY MORNING WATER VAPOR IMAGERY REVEALS
DIFFLUENT FLOW ACROSS MUCH OF THE DESERT SOUTHWEST...WITH SEVERAL
UPPER LOWS/SMALL-SCALE SHORTWAVES IN/AROUND ARIZONA. A WEAK
SHORTWAVE WAS NOTED ACROSS SOUTHEAST CALIFORNIA AS OF 08Z...WITH
ANOTHER MUCH STRONGER WAVE OVER THE GULF OF CALIFORNIA. MEANWHILE
ANOTHER LOW WAS DEEPENING OFF THE COAST OF OREGON. ALL OF THESE WILL
PLAY A ROLE IN THE WEATHER ACROSS THE REGION AT VARIOUS TIMES
THROUGH THE MIDDLE OF NEXT WEEK.
THE SOUTHERN-MOST SHORTWAVE OVER THE GULF OF CALIFORNIA IS FAIRLY
POTENT AND HAS SOME UPPER LEVEL SUPPORT TO WORK WITH...HAS DEEPENED
SOMEWHAT SINCE MIDNIGHT...AND IS LOCATED WITHIN AN AREA OF MODEST MID
LEVEL INSTABILITY. UNFORTUNATELY...IT HASN`T BEEN INITIALIZED
PARTICULARLY WELL BY ANY OF THE 00Z OR 06Z LARGE-SCALE DETERMINISTIC
MODELS. ONLY THE RAP AND THE HRRR /NOT SURPRISINGLY/ HAVE CORRECTLY
IDENTIFIED THIS FEATURE AND MATCH CURRENT RADAR/OBSERVATIONAL TRENDS.
EXPECTING SHOWERS AND STORMS TO CONTINUE TO BLOSSOM OVERNIGHT ACROSS
PORTIONS OF ARIZONA...BUT QUICKLY SHIFT EAST INTO NEW MEXICO LATER
TODAY. AS SUCH...I WILL MAINTAIN 20-30 POPS THIS MORNING TO ACCOUNT
FOR THE POSSIBILITY OF SHOWERS WITH THIS WAVE. MEANWHILE...THE WAVE
OVER THE LOWER COLORADO RIVER VALLEY WILL SHIFT EAST THIS AFTERNOON
AND INTERACT WITH A FAIRLY FAVORABLE ENVIRONMENT. THERMODYNAMIC
PARAMETERS ARE NOT AS IMPRESSIVE AS THEY WERE YESTERDAY...MLCAPES ARE
ONLY AROUND 250-500 J/KG AND DEEP LAYER /0-6KM/ SHEAR IS ONLY AROUND
15KTS. EXPECTING SOME ACTIVITY LATER THIS AFTERNOON INTO THE EVENING
HOURS...BUT PERHAPS NOT AS MUCH AS WHAT WAS SEEN ON FRIDAY.
SUNDAY AND MONDAY LOOK TO BE LESS ACTIVE STORM-WISE ALTHOUGH BROAD
SOUTHWESTERLY FLOW ALOFT...ELEVATED PWATS...MODEST INSTABILITY...AND
THE SUGGESTION OF WEAK/SUBTLE SHORTWAVES IN ALL OPERATIONAL MODELS COULD
STILL RESULT IN MOUNTAIN SHOWERS AND STORMS BOTH DAYS. MITIGATING
FACTORS ACROSS THE DESERTS SUCH AS INCREASED CLOUD COVER COULD LIMIT
INSTABILITY TO THE POINT WHERE MLCAPES ARE VIRTUALLY ZERO...BUT STILL
SEEMS THAT SLIGHTLY HIGHER THAN NORMAL POPS ARE WARRANTED /ESPECIALLY
EAST OF PHOENIX/.
MEANWHILE...THE LOW PRESENTLY WEST OF OREGON WILL MOVE INLAND AND
DIVE SOUTHWARD...EVENTUALLY STALLING ACROSS ARIZONA ON TUESDAY.
QUITE A BIT OF UNCERTAINTY REMAINS IN TERMS OF PRECIP CHANCES AS I
WOULD NORMALLY EXPECT IMPRESSIVE PWATS GIVEN THE POTENTIAL FOR STRONG
SOUTHERLY FLOW AHEAD OF THIS SYSTEM. WHILE IT SEEMS INCREASINGLY
LIKELY THAT SHOWERS WILL BE POSSIBLE TUESDAY THROUGH THURSDAY OF NEXT
WEEK...GEFS/NAEFS PWATS AREN`T PARTICULARLY HIGH AND AREN`T FORECAST
TO RISE MUCH ABOVE 1-2 STDEV ABOVE NORMAL /NOT EVEN INTO THE 90TH
PERCENTILE/. NAEFS POPS ONLY SHOWING 40-50 PERCENT MAX ON TUESDAY
WITH THE ARRIVAL OF THE LOW...THEN QUICKLY DROPPING OFF WEDNESDAY AND
THURSDAY. FOLLOWED THE NAEFS FAIRLY CLOSELY FOR NEXT WEEK AND WILL
HOLD SHORT OF BUMPING UP POPS MUCH FURTHER UNLESS PWATS TAKE A
NOTEWORTHY JUMP UPWARD. ALL DETERMINISTIC AND PROBABILISTIC MODELS
SUGGEST A RETURN TO DRY WESTERLY FLOW LATE IN THE WEEK INTO NEXT
WEEKEND.
AS FOR TEMPERATURES...ASIDE FROM TODAY MOST LOCATIONS SHOULD BE
LOOKING AT BELOW NORMAL TEMPERATURES THROUGH LATE NEXT WEEK COURTESY
OF UPPER LEVEL TROUGHING/INCREASED CLOUD COVER. WITH THE UPPER LOW
OVERHEAD ON TUESDAY...HIGHS COULD CONCEIVABLY STRUGGLE TO BREAK OUT
OF THE MID 80S PER LATEST CONSENSUS MODEL GUIDANCE AND TEMPERATURES
WERE LOWERED ACCORDINGLY NEXT WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
ISOLATED SHOWERS AND GUSTY E/NE SFC WINDS WILL BE THE PRIMARY
AVIATION CONCERNS THROUGH THIS AFTERNOON. AN ISOLD TSRA COULD BE
EMBEDDED WITH THE SHOWERS...HOWEVER COVERAGE LOOKS VERY SPARSE. THE
MOST LIKELY TIME FRAME FOR SCT SHOWERS WILL BE THROUGH 14Z
THIS MORNING...AND THEN AGAIN LATE THIS AFTERNOON AND EARLY EVENING.
SFC WINDS SHOULD MAINTAIN A GENERAL EASTERLY COMPONENT THROUGH THE
PERIOD...THOUGH COULD OCCASIONAL DRIFT BETWEEN NNE AND SE. STRONGER
GUSTS ABOVE 20KT WILL BE LIKELY LATE THIS MORNING/EARLY AFTERNOON.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
DECREASING CHANCES OF SHOWERS AND THUNDERSTORMS TODAY...TOO LIMITED
COVERAGE FOR INCLUDING IN TAFS AT THIS TIME. SHIFTING VARIABLE SFC
WINDS WILL BE COMMON...AND OVERALL CONFIDENCE IN TIMING ANY SPECIFIC
WIND SHIFT IS RATHER LOW.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UNSETTLED WEATHER EARLY NEXT WEEK WILL SLOWLY TRANSITION TO DRIER
CONDITIONS WITH SEVERAL DISTURBANCES PASSING THROUGH THE DISTRICT.
LIGHTER SHOWERS WILL FAVOR HIGHER TERRAIN LOCATIONS OF EASTERN
ARIZONA. AFTERNOON HUMIDITY VALUES IN A 25 TO 35 PERCENT RANGE EARLY
IN THE WEEK WILL ONLY DECREASE TO A 15 TO 25 PERCENT RANGE BY THE
MIDDLE AND END OF NEXT WEEK. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. A FEW STRONGER NORTHERLY WIND GUSTS DOWN THE LOWER
COLORADO RIVER VALLEY WILL BE POSSIBLE TUESDAY AND WEDNESDAY
AFTERNOON. OTHERWISE...WINDS WILL GENERALLY BE LIGHT AND NOT A FIRE
WEATHER IMPACT.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/LEINS
AVIATION...KUHLMAN
FIRE WEATHER...DEWEY
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
513 AM MST SAT OCT 17 2015
.UPDATE...UPDATED AVIATION DISCUSSION...
&&
.SYNOPSIS...
A SERIES OF SLOW MOVING LOW PRESSURE SYSTEMS WILL BRING ELEVATED
CHANCES OF SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH THE MIDDLE
OF NEXT WEEK. SHOWERS AND STORMS ARE POSSIBLE AGAIN TODAY AND
SUNDAY WITH A SLIGHT DRYING TREND ON MONDAY. THIS WILL BE SHORT
LIVED HOWEVER AS A SECOND LOW MOVES INTO THE DESERT SOUTHWEST ON
TUESDAY AND REMAINS IN PLACE THROUGH THURSDAY. DRIER AIR WILL MOVE
INTO THE AREA LATE NEXT WEEK.
&&
.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY REVEALS DIFFLUENT FLOW ACROSS MUCH
OF THE DESERT SOUTHWEST...WITH SEVERAL UPPER LOWS/SMALL-SCALE
SHORTWAVES IN/AROUND ARIZONA. A WEAK SHORTWAVE WAS NOTED ACROSS
SOUTHEAST CALIFORNIA AS OF 08Z...WITH ANOTHER MUCH STRONGER WAVE OVER
THE GULF OF CALIFORNIA. MEANWHILE ANOTHER LOW WAS DEEPENING OFF THE
COAST OF OREGON. ALL OF THESE WILL PLAY A ROLE IN THE WEATHER ACROSS
THE REGION AT VARIOUS TIMES THROUGH THE MIDDLE OF NEXT WEEK.
THE SOUTHERN-MOST SHORTWAVE OVER THE GULF OF CALIFORNIA IS FAIRLY
POTENT AND HAS SOME UPPER LEVEL SUPPORT TO WORK WITH...HAS DEEPENED
SOMEWHAT SINCE MIDNIGHT...AND IS LOCATED WITHIN AN AREA OF MODEST MID
LEVEL INSTABILITY. UNFORTUNATELY...IT HASN`T BEEN INITIALIZED
PARTICULARLY WELL BY ANY OF THE 00Z OR 06Z LARGE-SCALE DETERMINISTIC
MODELS. ONLY THE RAP AND THE HRRR /NOT SURPRISINGLY/ HAVE CORRECTLY
IDENTIFIED THIS FEATURE AND MATCH CURRENT RADAR/OBSERVATIONAL TRENDS.
EXPECTING SHOWERS AND STORMS TO CONTINUE TO BLOSSOM OVERNIGHT ACROSS
PORTIONS OF ARIZONA...BUT QUICKLY SHIFT EAST INTO NEW MEXICO LATER
TODAY. AS SUCH...I WILL MAINTAIN 20-30 POPS THIS MORNING TO ACCOUNT
FOR THE POSSIBILITY OF SHOWERS WITH THIS WAVE. MEANWHILE...THE WAVE
OVER THE LOWER COLORADO RIVER VALLEY WILL SHIFT EAST THIS AFTERNOON
AND INTERACT WITH A FAIRLY FAVORABLE ENVIRONMENT. THERMODYNAMIC
PARAMETERS ARE NOT AS IMPRESSIVE AS THEY WERE YESTERDAY...MLCAPES ARE
ONLY AROUND 250-500 J/KG AND DEEP LAYER /0-6KM/ SHEAR IS ONLY AROUND
15KTS. EXPECTING SOME ACTIVITY LATER THIS AFTERNOON INTO THE EVENING
HOURS...BUT PERHAPS NOT AS MUCH AS WHAT WAS SEEN ON FRIDAY.
SUNDAY AND MONDAY LOOK TO BE LESS ACTIVE STORM-WISE ALTHOUGH BROAD
SOUTHWESTERLY FLOW ALOFT...ELEVATED PWATS...MODEST INSTABILITY...AND
THE SUGGESTION OF WEAK/SUBTLE SHORTWAVES IN ALL OPERATIONAL MODELS COULD
STILL RESULT IN MOUNTAIN SHOWERS AND STORMS BOTH DAYS. MITIGATING
FACTORS ACROSS THE DESERTS SUCH AS INCREASED CLOUD COVER COULD LIMIT
INSTABILITY TO THE POINT WHERE MLCAPES ARE VIRTUALLY ZERO...BUT STILL
SEEMS THAT SLIGHTLY HIGHER THAN NORMAL POPS ARE WARRANTED /ESPECIALLY
EAST OF PHOENIX/.
MEANWHILE...THE LOW PRESENTLY WEST OF OREGON WILL MOVE INLAND AND
DIVE SOUTHWARD...EVENTUALLY STALLING ACROSS ARIZONA ON TUESDAY.
QUITE A BIT OF UNCERTAINTY REMAINS IN TERMS OF PRECIP CHANCES AS I
WOULD NORMALLY EXPECT IMPRESSIVE PWATS GIVEN THE POTENTIAL FOR STRONG
SOUTHERLY FLOW AHEAD OF THIS SYSTEM. WHILE IT SEEMS INCREASINGLY
LIKELY THAT SHOWERS WILL BE POSSIBLE TUESDAY THROUGH THURSDAY OF NEXT
WEEK...GEFS/NAEFS PWATS AREN`T PARTICULARLY HIGH AND AREN`T FORECAST
TO RISE MUCH ABOVE 1-2 STDEV ABOVE NORMAL /NOT EVEN INTO THE 90TH
PERCENTILE/. NAEFS POPS ONLY SHOWING 40-50 PERCENT MAX ON TUESDAY
WITH THE ARRIVAL OF THE LOW...THEN QUICKLY DROPPING OFF WEDNESDAY AND
THURSDAY. FOLLOWED THE NAEFS FAIRLY CLOSELY FOR NEXT WEEK AND WILL
HOLD SHORT OF BUMPING UP POPS MUCH FURTHER UNLESS PWATS TAKE A
NOTEWORTHY JUMP UPWARD. ALL DETERMINISTIC AND PROBABILISTIC MODELS
SUGGEST A RETURN TO DRY WESTERLY FLOW LATE IN THE WEEK INTO NEXT
WEEKEND.
AS FOR TEMPERATURES...ASIDE FROM TODAY MOST LOCATIONS SHOULD BE
LOOKING AT BELOW NORMAL TEMPERATURES THROUGH LATE NEXT WEEK COURTESY
OF UPPER LEVEL TROUGHING/INCREASED CLOUD COVER. WITH THE UPPER LOW
OVERHEAD ON TUESDAY...HIGHS COULD CONCEIVABLY STRUGGLE TO BREAK OUT
OF THE MID 80S PER LATEST CONSENSUS MODEL GUIDANCE AND TEMPERATURES
WERE LOWERED ACCORDINGLY NEXT WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
ISOLATED SHOWERS AND GUSTY E/NE SFC WINDS WILL BE THE PRIMARY
AVIATION CONCERNS THROUGH THIS AFTERNOON. AN ISOLD TSRA COULD BE
EMBEDDED WITH THE SHOWERS...HOWEVER COVERAGE LOOKS VERY SPARSE. THE
MOST LIKELY TIME FRAME FOR SCT SHOWERS WILL BE THROUGH 14Z
THIS MORNING...AND THEN AGAIN LATE THIS AFTERNOON AND EARLY EVENING.
SFC WINDS SHOULD MAINTAIN A GENERAL EASTERLY COMPONENT THROUGH THE
PERIOD...THOUGH COULD OCCASIONAL DRIFT BETWEEN NNE AND SE. STRONGER
GUSTS ABOVE 20KT WILL BE LIKELY LATE THIS MORNING/EARLY AFTERNOON.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
DECREASING CHANCES OF SHOWERS AND THUNDERSTORMS TODAY...TOO LIMITED
COVERAGE FOR INCLUDING IN TAFS AT THIS TIME. SHIFTING VARIABLE SFC
WINDS WILL BE COMMON...AND OVERALL CONFIDENCE IN TIMING ANY SPECIFIC
WIND SHIFT IS RATHER LOW.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UNSETTLED WEATHER EARLY NEXT WEEK WILL SLOWLY TRANSITION TO DRIER
CONDITIONS WITH SEVERAL DISTURBANCES PASSING THROUGH THE DISTRICT.
LIGHTER SHOWERS WILL FAVOR HIGHER TERRAIN LOCATIONS OF EASTERN
ARIZONA. AFTERNOON HUMIDITY VALUES IN A 25 TO 35 PERCENT RANGE EARLY
IN THE WEEK WILL ONLY DECREASE TO A 15 TO 25 PERCENT RANGE BY THE
MIDDLE AND END OF NEXT WEEK. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. A FEW STRONGER NORTHERLY WIND GUSTS DOWN THE LOWER
COLORADO RIVER VALLEY WILL BE POSSIBLE TUESDAY AND WEDNESDAY
AFTERNOON. OTHERWISE...WINDS WILL GENERALLY BE LIGHT AND NOT A FIRE
WEATHER IMPACT.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...KUHLMAN
FIRE WEATHER...DEWEY
AREA FORECAST DISCUSSION
NWS TUCSON AZ
322 AM MST SAT OCT 17 2015
.SYNOPSIS...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CAN BE
EXPECTED AGAIN TODAY FOLLOWED BY LESS COVERAGE OF SHOWERS AND
THUNDERSTORMS SUNDAY INTO MONDAY. A LOW PRESSURE SYSTEM WILL THEN
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY INTO WEDNESDAY.
NEAR NORMAL DAYTIME TEMPERATURES WILL PREVAIL THIS WEEKEND FOLLOWED
BY BELOW NORMAL HIGH TEMPERATURES BY MIDWEEK.
&&
.DISCUSSION...ANOTHER BATCH OF SHOWERS AND THUNDERSTORMS HAD
DEVELOPED ACROSS SANTA CRUZ...COCHISE...AND EASTERN PIMA COUNTY
EARLY THIS MORNING. AUTOMATED GAUGES WERE SHOWING SOME DECENT
RAINFALL RATES WITH A FEW OF THE STRONGER THUNDERSTORMS BUT THE
RATHER FAST MOVEMENT OF THEM SHOULD LESSEN THE THREAT OF FLASH
FLOODING. HOWEVER...TRAINING CELLS IN A FEW SPOT ACROSS WESTERN
COCHISE INTO SANTA CRUZ COUNTIES WILL LIKELY BE A CONCERN THIS
MORNING. THAT SAID...LATEST HRRR SOLUTIONS KEEP MOST OF THE AREA
UNDER THE THREAT OF SHOWERS AND THUNDERSTORMS TODAY AS THE UPPER
TROUGH AXIS SWINGS THROUGH THE STATE. THEREAFTER...THE RAIN CHANCES
LOWER SIGNIFICANTLY LATER TONIGHT INTO SUNDAY AND MONDAY.
HOWEVER...MORE RAIN WILL BE ON THE WAY TUESDAY AS ANOTHER SYSTEM
DROPS SOUTH INTO SOUTHERN CALIFORNIA AND THEN HANGS OUT NEAR ARIZONA
THROUGH LATE WEDNESDAY OR EARLY THURSDAY. HIGH TEMPERATURES WILL
EVENTUALLY LOWER TO READINGS SLIGHTLY BELOW NORMAL AROUND TUESDAY
AND WEDNESDAY AS THE NEXT SYSTEM ARRIVES.
&&
.AVIATION...VALID THRU 18/12Z.
SCTD -SHRA/TSRA. MVFR AND BRIEF IFR CONDS WILL OCCUR AT TIMES THRU
THE PERIOD. OTHERWISE...CLOUD DECKS WILL BE AROUND 8-12K FT AGL AND
SFC WIND WILL GENERALLY BE ELY/SELY AT 5-15 KTS WITH GUSTS TO AROUND
25 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...SHOWERS AND ISOLATED THUNDERSTORMS TODAY WITH LESS
AREAL COVERAGE OF STORMS SUNDAY AND MONDAY. UNSETTLED WEATHER WILL
CONTINUE TUESDAY AND WEDNESDAY WITH ANOTHER CHANCE OF SHOWERS AND
THUNDERSTORMS. DRY CONDITIONS IS EXPECTED THURSDAY AND FRIDAY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
447 AM PDT SAT OCT 17 2015
.SYNOPSIS... A PACIFIC WEATHER SYSTEM WILL MOVE INTO NORTHERN AND
CENTRAL CALIFORNIA TODAY. THIS SYSTEM MAY PRODUCE A FEW SHOWERS
LATER THIS MORNING INTO THE AFTERNOON AS A FRONT GOES ACROSS. IN
ADDITION...THERE IS A CHANCE OF ISOLATED THUNDERSTORMS IN THE
AFTERNOON AND EVENING AS MORE UNSTABLE AIR MOVES IN BEHIND THE
FRONT. TEMPERATURES ARE FORECAST TO COOL BACK TO NEAR NORMAL BY
SUNDAY AND MONDAY...AND THEN WARM BACK A BIT ABOVE SEASONAL NORMS
BY THE MIDDLE OF NEXT WEEK AS HIGH PRESSURE BUILDS OVER
CALIFORNIA.
&&
.DISCUSSION...AS OF 3:10 AM PDT SATURDAY...KMUX RADAR IS SHOWING
AN INCREASE IN ECHOES OFF THE SONOMA COAST THIS MORNING WHICH ARE
OUT IN ADVANCE OF A COLD FRONT THAT WILL MOVE THROUGH OUR CWA
LATER TODAY. MODELS BRING A FEW LIGHT SHOWERS ACROSS OUR AREA AT
THE SAME TIME ALTHOUGH LAST FEW MODEL RUNS HAVE TRENDED DRIER WITH
SOME SHOWING VIRTUALLY NO RAINFALL THROUGH NOON. AS THE FRONT
MOVES THROUGH STARTING LATE IN THE AFTERNOON MORE UNSTABLE AIR
WILL FILTER IN BEHIND IT. THIS WILL LIKELY GIVE US OUR BEST SHOT
OF GETTING TIPS OF THE BUCKET AND POSSIBLY A FEW THUNDERSTORMS AS
WELL. CURRENTLY LOOKS LIKE THE BEST BET WILL BE OVER THE EASTERN
CWA WHERE LIFTED VALUES DROP DOWN TO LESS THAN NEGATIVE 1.5.
OVERALL FORECAST WAS ONLY SLIGHTLY ADJUSTED FROM THE PREVIOUS
SHIFT. ALMOST ALL SHOWERS SHOULD END BY MIDNIGHT.
NEXT WEEK GENERALLY LOOK VERY QUIET WEATHER WISE AS A RIDGE OF
HIGH PRESSURE BUILDS OFF THE COAST THROUGH AT LEAST WEDNESDAY,
AND POSSIBLY THROUGH THROUGH THURSDAY. TEMPS WILL GENERALLY RETURN
TO WARMER THAN NORMAL LEVELS BY TUESDAY DUE TO THE RIDGE AND
OFFSHORE FLOW. THE RIDGE WILL BREAK DOWN BY THE END OF THE WEEK
LEADING TO COOLER TEMPS ALTHOUGH RAINFALL SHOULD STAY WELL TO THE
NORTH.
&&
.AVIATION...AS OF 04:45 PM PDT SATURDAY... WIDESPREAD MVFR CIGS AS
DEEP MARINE LAYER PUSHES INLAND AHEAD OF APPROACHING UPPER
TROUGH. VCSH FOR NORTH BAY THROUGH THE MORNING... BUT NO THREAT
OF WET RUNWAYS AS RAINFALL AMOUNTS SHOULD BE LIMITED. ONSHORE
WINDS 10 TO 20 KT. MVFR CIGS WILL PERSIST AT SOME TAF SITES
THROUGH MOST OF THE DAY BEFORE LOWERING TO IFR CIGS LATE SATURDAY
NIGHT.
VICINITY OF KSFO...MVFR CIGS THROUGH THE MORNING. IFR CIGS AFTER
10Z SUN. PEAK ONSHORE WINDS 15 TO 20 KT SAT AFTERNOON.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR POSBL THROUGH THE DAY. IFR CIGS
POSBL AFTER 02Z SUN. ONSHORE WINDS 5 TO 10 KT.
&&
.MARINE...AS OF 10:40 PM PDT FRIDAY...AN UPPER LEVEL LOW WILL
MOVE INTO NORTHERN CALIFORNIA ON SATURDAY. HIGH PRESSURE WILL
BUILD OFF THE CALIFORNIA COAST BEHIND THE LOW RESULTING IN
INCREASING NORTHWEST WINDS SATURDAY NIGHT AND SUNDAY. WINDS WILL
DECREASE OVER THE INNER WATERS EARLY NEXT WEEK AS THE HIGH SHIFTS
NORTH AND THERMAL TROUGH MOVES TO THE COAST.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 4 PM
&&
$$
PUBLIC FORECAST: BELL
AVIATION: DRP
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
Area Forecast Discussion
National Weather Service Sacramento CA
430 AM PDT SAT OCT 17 2015
SYNOPSIS...
An unsettled weekend with cool temperatures and
showers/thunderstorms. This will give way to a breezy beginning
of the week with warming temperatures.
&&
.DISCUSSION
Quite an eventful overnight shift. A North-South line of
showers/thunderstorms began to develop after 1 am. By 2 am, this
line generally impacted valley areas between Modesto up towards
Red Bluff with the Sacramento region getting hit the hardest.
Multiple reports of lightning with brief, heavy downpours in and
around the Sac Metro region. The Downtown Sacramento rain gauge
measured over 0.30" between 1-2 am. By 3 am, the gauge had
measured 0.38" of rain. This line gradually moved northeastward
and by 3:15 am, it looked like part of the line was headed towards
the Butte Wildfire Scar. Between 3:30-3:45 am, the showers were
diminishing on radar just west of the scar. Hourly rate of rain
with these cells is below debris flow critera for the burn scar,
but we will continue to monitor this morning. As of 4:30 am there
were almost 200 lightning strikes between the Modesto to Oroville
area and including the Western Sierra slopes.
Instability will continue through tonight. Have added slight
chance of thunderstorms to the Western Sierra Slope Foothills and
Mountains between 5 am to 11 am since that`s where the line of
showers/thunderstorms is currently located and the HRRR also
indicates activity in that region this morning. In the afternoon,
HRRR shows a isolated shower activity in the valley, but it will
be hit or miss. Daytime highs today will be near to a couple
degrees below normal for this time of year with valley highs in
the mid 70s, mountains in the 50s and 60s.
The low lingers over NorCal into Sunday and shower activity should be
limited to the higher elevations of the Sierra. Daytime highs will
be similar to today...near to a little below normal. By Monday
morning the low will be northeast of our region and a warming
trend begins with dry weather. More notable warming occurs Tuesday
as daytime highs around 10 degrees above normal with valley highs
back around the mid 80s. JBB
&&
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)
The extended period starts out dry under a ridge of high pressure
between a low centered over northern Baja and another trough in
the Gulf of Alaska. Wedmesday will likely be the warmest day with
daytime highs expected to come in between 5 and 10 degrees above
normal. A small scale upper trough is forecast to pass through the
Pacific Northwest on Thursday. This should bring a little cooling
but daytime highs are still likely to remain several degrees above
normal. Extended models begin to deviate on Friday in regards to
another upper trough digging out of the Gulf of Alaska. Both models
put this system over the Pacific Northwest coast by Friday
afternoon but GFS somewhat deeper bringing precipitation to the
far northern portions of California while the ECMWF is more
shallow with the system keeping any precip well north of the
state. GFS would indicate the possibility of some shower activity
northern zones next Saturday while the ECMWF would keep the region
dry. Have kept slight threat of precipitation over the northern
zones Saturday in coordination with 00z GFS and surrounding
offices. This represents a trend of pulling precipitation farther
northward and quick look at 06z GFS shows this trend continuing.
If this trend continues...may end up removing precip from forecast
all together next weekend. Either way...cooler temperatures still
in store for end of the week although daytime highs are still
likely to remain at least a little above normal.
&&
.AVIATION...
Mainly VFR conditions today all TAF sites but widespread showers
and thunderstorms are possible through about 06z Sunday. Surface
winds south to southwest today sustained below 15 knots except
strong and variable near thunderstorms. More variable winds after
06Z.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
622 AM CDT SAT OCT 17 2015
...Updated Aviation Discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT SAT OCT 17 2015
Today, we have a major adjustment for high temperatures, especially
across our eastern counties, say east of the highway 283 corridor,
where lingering stratus into the afternoon will significantly impact
the highs for the day. The far west will still have enough
insolation for highs to reach the mid 70s, however the coolest areas
will be from Hays to Stafford. Clouds could break up in the central
counties by late afternoon, past peak heating.
An upper ridge will gradually build eastward across the Central
Plains through the weekend, as the surface high pressure shifts from
the upper Midwest into the Ohio valley. As a result, today and into
sunday will see a gradual shift to increasing winds speeds both days,
and more downslope on Sunday as surface troughing develops over
eastern Colorado. This will also reflect in higher temperatures going
forward into Sunday. Overnight lows could be tougher to forecast in
the presence of difficult to predict stratus layers. For tonight,
the NAM is far cooler than other modes and guidance. With the
generally warmer airmass coming into early next week, lows will be
back in the 50s Sunday night.
.LONG TERM...(Sunday THROUGH Friday)
ISSUED AT 320 AM CDT SAT OCT 17 2015
Overnight lows will continue to be in the 50s through around
midweek, with less certainty heading into the end of the week.
Recent runs of the GFS and ECMWF models seem to have slowed the
timing of the strong upper low moving into the desert southwest and
subsequent intense surge of isentropically forced rain/convection
for the central/southern Plains region into the Thursday night or
Friday timeframe. As a result, pops were adjusted to account for
this trend.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Sunday MORNING)
ISSUED AT 621 AM CDT SAT OCT 17 2015
06z NAM BUFR soundings along with the latest RAP and HRRR were all
in good agreement with low VFR ceilings giving way to clearing
skies from west to east late this morning and early this
afternoon. Gusty southeast winds at near 20 knots will also be
developing by late morning as 30 knot winds in the 900mb to 850mb
level mixes down to the surface and surface pressures falls along
the lee of the Rockies.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 70 51 79 57 / 0 0 0 0
GCK 74 52 79 57 / 0 0 0 0
EHA 77 54 77 55 / 0 0 0 0
LBL 75 53 79 57 / 0 0 0 0
HYS 64 49 80 59 / 0 0 0 0
P28 66 49 77 56 / 0 0 0 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
612 AM CDT SAT OCT 17 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 245 AM CDT SAT OCT 17 2015
SATELLITE LOOP SHOWS AREA OF MID CLOUDS HAS BEEN EXPANDING
SOUTHWARD ACROSS EASTERN NEBRASKA AND WESTERN IOWA LIKELY
LIMITING FROST POTENTIAL FOR THE AREA THIS MORNING. RAP 700 RH
ALSO SHOWS THIS TREND THROUGH 15Z. PLAN TO KEEP ADVISORY GOING
FOR NOW BUT MENTION MORE LIMITED EXTENT IN WORDING OF STATEMENT.
LITTLE CHANGE OTHERWISE TO REMAINDER OF THE FORECAST THROUGH
MONDAY WITH WARMING TREND AND DRY CONDITIONS STILL ON TRACK.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 245 AM CDT SAT OCT 17 2015
EXTENDED PERIOD CONTINUES TO SHOW SIGNS OF A MORE ACTIVE PATTERN
AS CLOSED LOW OVER THE FAR SOUTHWEST GRADUALLY OPENS AND PHASES
WITH THE NORTHERN STREAM BY LATE IN THE PERIOD. GOOD MOISTURE
FETCH DEVELOPS ACROSS THE CENTRAL PART OF THE NATION IN ADVANCE
OF THE TROUGH WITH AN INCREASING CHANCE OF SHOWERS FOR THE AREA
DURING THE PERIOD AS THIS SYSTEM DEVELOPS. THE SOUTHERLY FLOW
WILL ALSO HELP TO MAINTAIN ABOVE NORMAL TEMPERATURES DURING THIS
TIME.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 611 AM CDT SAT OCT 17 2015
VFR CONDITIONS EXPECTED THRU THE FCST PD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR IAZ043-055-056-
069-079-080-090-091.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1021 AM EDT SAT OCT 17 2015
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL PRODUCE MUCH BELOW
NORMAL TEMPERATURES ALONG WITH SCATTERED RAIN AND SNOW SHOWERS. SNOW
ACCUMULATIONS OF A DUSTING TO 3 INCHES IS EXPECTED ABOVE 1500
FEET. TEMPERATURES WILL HOLD MAINLY IN THE 30S MOUNTAINS AND 40S
VALLEYS TODAY WITH LOWS IN THE 20S TO MID 30S TONIGHT. SOME AREAS
OF FROST ARE LIKELY IN THE CHAMPLAIN VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1020 AM EDT SATURDAY...GOING FORECAST IS IN GREAT SHAPE
WITH JUST A FEW TWEAKS NEEDED TO POPS AND TEMPS FOR THE NEXT FEW
HOURS. OTHERWISE, REMAINDER OF FORECAST REMAIN INTACT.
PREVIOUS DISCUSSION...HAVE INCREASED HOURLY TEMPS BY 2 TO 4
DEGREES ACROSS PARTS OF THE CHAMPLAIN VALLEY AND NORTHERN/CENTRAL
VT BASED ON CURRENT OBSERVATIONS. CURRENT SURFACE ANALYSIS SHOWS
COLD FRONT ACROSS THE CHAMPLAIN VALLEY WITH WINDS JUST SHIFTING TO
THE WEST AT BURLINGTON,VT. RADAR SHOWS SCATTERED RAIN AND MOUNTAIN
SNOW SHOWERS ACROSS NORTHERN NEW YORK AND INTO PARTS OF NORTHERN
VT. HAVE NOTED SLK HAS 4SM -SHSN WITH A TEMP OF 34F. EXPECTING
SNOWFALL ACCUMULATIONS ABOVE 1500 FEET TODAY OF A DUSTING TO
SEVERAL INCHES POSSIBLE. JUST GOT A REPORT FROM STOWE MOUNTAIN
THAT WET SNOW FLAKES ARE OCCURRING AT 1500 FEET. ALL IS COVERED
WELL IN CURRENT FORECAST....GIVEN THE MAGNITUDE OF COLD AIR
ADVECTION THINKING TEMPERATURES WILL HOLD STEADY OR FALL SLIGHTLY
TODAY. WHITEFACE ALREADY DOWN TO 25F WITH BRISK NORTHWEST WINDS.
WATER VAPOR SHOWS A DEEP MID/UPPER LEVEL TROUGH OF LOW PRESSURE
ACROSS THE NORTHEAST UNITED STATES. SEVERAL DISTURBANCES IN THE
FLOW ALOFT WILL CONTINUE TO IMPACT OUR REGION THROUGH
SUNDAY...WITH AREAS OF RAIN AND SNOW SHOWERS. AS SURFACE LOW
PRESSURE TRACKS INTO NORTHERN MAINE TODAY...EXPECT WINDS TO SHIFT
TO THE NORTHWEST BY 15Z...WHICH WILL HELP REFOCUS PRECIPITATION
ACROSS THE UPSLOPE REGIONS OF THE NORTHERN DACKS AND
CENTRAL/NORTHERN GREEN MOUNTAINS. THE NAM12/BTV 4KM AND HRRR SHOW
FAVORABLE MOISTURE AND WIND DIRECTION FOR TERRAIN DRIVEN UPSLOPE
PRECIPITATION FROM 12Z THROUGH 18Z TODAY. HOWEVER...SOUNDINGS SHOW
DEPTH OF 925MB TO 700MB MOISTURE DECREASES BY 21Z TODAY...AS
NORTHWEST WINDS ADVECT DRIER AIR INTO THE REGION. THIS WILL
DECREASE AREAL COVERAGE OF UPSLOPE PRECIPITATION BY EVENING...WITH
JUST FLURRIES POSSIBLE OVERNIGHT TONIGHT. QPF AMOUNTS VARY GREATLY
DEPENDING UPON THE MODEL WITH LATEST 00Z BTV 4KM SHOWING 0.60 ALL
SNOW AT JAY PEAK WHILE GFS HAS AROUND 0.35...AND THE NAM12 IS ONLY
0.10. GIVEN TRACK OF SURFACE LOW PRESSURE NORTH OF OUR CWA AND
LACK OF ATLANTIC MOISTURE ADVECTING INTO THE SYSTEM WITH NO CLOSED
UPPER LEVELS...THINKING QPF WILL BE ON THE LIGHTER SIDE. AMOUNTS
WILL RANGE FROM A TRACE TO COUPLE HUNDRETHS IN THE VALLEY TO A
0.25 OR SO FROM MOUNT MANSFIELD TO JAY PEAK...AND SIMILAR ACROSS
THE NORTHERN DACKS. AT 12Z THIS MORNING THERMAL PROFILES SHOW SNOW
LEVELS AROUND 1800 FEET ACROSS THE DACKS AND NEAR 2200 FEET IN THE
CENTRAL GREENS...BUT WITH STRONG LOW LEVEL COLD AIR ADVECTION ON
BRISK NORTHWEST WINDS...THERMAL PROFILES CONTINUE TO COOL...WITH
SNOW LEVELS DROPPING AROUND 1500 FEET BY MIDDAY. BOUNDARY LAYER
TEMPS BETWEEN 3 AND 4C AND LACK OF SIGNIFICANT MOISTURE IN THE
CHAMPLAIN VALLEY WILL LIMIT SNOW ACCUMULATION...MAYBE A FEW WET
SNOW FLAKES WITH THE HEAVIER SHOWERS. THINKING ACCUMULATIONS WILL
RANGE FROM 2 TO 4 INCHES SUMMITS OF THE DACKS AND THE NORTHERN
GREEN MOUNTAINS FROM JAY PEAK TO SUGARBUSH TO A DUSTING TO 2
INCHES HIGHER MOUNTAIN VALLEYS ABOVE 1500 FEET. TEMPS WILL RANGE
FROM THE MID/UPPER 20S SUMMITS TO LOWER/MID 40S CHAMPLAIN VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 345 AM EDT SATURDAY...FORECAST CONCERN TONIGHT WILL BE
TEMPERATURES AND POTENTIAL FOR FREEZE IN THE CHAMPLAIN VALLEY
WHERE THE GROWING SEASON CONTINUES. HAVE NOTED ON SOUNDING STRONG
BOUNDARY LAYER MIXING WITH WINDS OF 5 TO 10 KNOTS EXPECTED AS
REGION IS UNDER LOW LEVEL COLD AIR ADVECTION ON NORTHWEST FLOW.
ALSO...WITH DEEP MID/UPPER LEVEL TROUGH...COLD AIR ALOFT..AND WARM
LAKE CHAMPLAIN WATER...EXPECT SOME CLOUDS ACROSS THE CHAMPLAIN
VALLEY...HOLDING TEMPERATURES IN THE UPPER 20S TO MID 30SNEAR THE
LAKE. GIVEN THE CONDITIONS ABOVE...NOT THINKING A FROST WILL
DEVELOP...BUT MORE ALONG THE LINES OF A FREEZE...BUT WILL LET DAY
SHIFT DECIDE ON ANY POTENTIAL HEADLINES. ELSEWHERE...TEMPERATURES
WILL RANGE FROM THE UPPER TEENS MOUNTAIN SUMMITS TO MID 20S SAINT
LAWRENCE VALLEY AND PARTS OF CENTRAL VT. A FEW LEFTOVER MOUNTAIN
FLURRIES WILL BE POSSIBLE...BUT MOISTURE PROGGES ARE VERY DRY SO
ANY PRECIPITATION WILL BE LIGHT.
SUNDAY WILL FEATURE MID/UPPER LEVEL TROF WITH THE CORE OF THE
COLDEST AIR DIRECTLY OVERHEAD. THIS WILL RESULT IN THE COLDEST DAY
OF WEEKEND...WITH PROGGED 850MB TEMPERATURES BETWEEN -8C AND -10C.
THESE PROFILES WITH BRISK NORTHWEST WINDS OF 10 TO 20 KNOTS WILL
RESULT IN HIGHS ONLY IN THE UPPER 20S TO LOWER 30S MOUNTAIN TOWNS TO
NEAR 40F CHAMPLAIN AND SAINT LAWRENCE VALLEYS. SOUNDINGS SHOW VERY
STEEP LOW LEVEL LAPSE RATES OVER THE MOUNTAINS WITH SOME AVAILABLE
MOISTURE BETWEEN 900MB AND 700MB. THIS INSTABILITY...MOISTURE...AND
UPSLOPE FLOW SHOULD BE ENOUGH TO SUPPORT CONVECTIVE TYPE SNOW
SHOWERS...ESPECIALLY IN THE MOUNTAINS. GIVEN THESE INGREDIENTS WILL
MENTION HIGH CHANCE POPS IN THE MOUNTAINS AND SLIGHT CHANCE IN THE
VALLEYS FOR SUNDAY AFTERNOON...WITH A QUICK DUSTING TO 1 INCH
POSSIBLE IN THE HEAVIER CONVECTIVE ELEMENTS OVER THE MOUNTAINS.
SUNDAY NIGHT WILL BE THE COLDEST NIGHT OF THE SEASON FOR ALL
LOCATIONS ACROSS THE NORTH COUNTRY. 1030MB HIGH PRESSURE AXIS WILL
BE DIRECTLY OVERHEAD WITH PROGGED 850MB TEMPS NEAR -10C. THIS WILL
RESULT IN CLEAR SKIES AND LIGHT WINDS WITH TEMPERATURES RANGING FROM
NEAR 10F SLK/COLDER VALLEYS OF THE NORTHEAST KINGDOM TO MID/UPPER
TEENS MOUNTAIN TOWNS TO LOWER/MID 20S CHAMPLAIN/SAINT LAWRENCE
VALLEYS. A WIDESPREAD FROST IS EXPECTED ON SUNDAY NIGHT/MONDAY
MORNING ACROSS THE ENTIRE CHAMPLAIN VALLEY.
TEMPERATURES WILL REBOUND QUICKLY ON MONDAY WITH DEVELOPING
SOUTHWEST FLOW AND WARM AIR ADVECTION. PROGGED 850MB TEMPS WARM TO
NEAR 0C BY 00Z TUESDAY...PRODUCING HIGHS BACK INTO THE UPPER 30S
MOUNTAINS TO UPPER 40S WARMER VALLEYS. DRY CONDITIONS WILL PREVAIL
WITH BUILDING RIDGE ALOFT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 410 AM EDT SATURDAY...DEEP SOUTHWESTERLY FLOW PREVAILS ACROSS
NORTH COUNTRY MONDAY NIGHT IN ADVANCE OF SHORTWAVE AND ASSOCIATED
COLD FRONT APPROACHING FROM THE NORTHERN GREAT LAKES REGION.
EXPECT INCREASING CLOUDS OVERNIGHT WITH A CHANCE OF SHOWERS AFTER
MIDNIGHT...MAINLY ACROSS NORTHERN AREAS. CHANCE OF SHOWERS
AREAWIDE ON TUESDAY AS THE SHORTWAVE PASSES TO OUR NORTH AND COLD
FRONT WEAKENS WHILE DEPRESSING SOUTH ACROSS FORECAST AREA. DRIER
CONDITIONS FOR TUESDAY NIGHT INTO WEDNESDAY AS HIGH PRESSURE
ATTEMPTS TO BUILD BACK INTO THE REGION FROM THE NORTH. GFS AND
ECMWF THEN GO THEIR SEPARATE WAYS FOR LATER IN THE WEEK. GFS
MAINTAINS HIGH PRESSURE OVER THE AREA FOR MOST OF THE PERIOD WHILE
ECMWF CONTINUES TO SUGGEST THAT A DISTURBANCE WILL DEEPEN WHILE
MOVING SOUTHEAST FROM ONTARIO. HAVE STAYED CLOSE TO OUR EARLIER
FORECAST WHICH INCLUDED CHANCE OF SHOWERS WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...ALTHOUGH THIS FORECAST CONTAINS A HIGH DEGREE OF
UNCERTAINTY. DRIER CONDITIONS THEN EXPECTED FOR FRIDAY WHICH BOTH
GFS AND ECMWF SUGGEST WOULD CONTINUE INTO NEXT WEEKEND. MAX
TEMPERATURES EACH DAY MOSTLY IN THE 50S IN THE VALLEYS...WITHIN A
FEW DEGREES OF NORMAL.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 12Z SUNDAY...TROUGH OF LOW PRESSURE WILL BRING LIGHT RAIN
SHOWERS TO THE AREA THIS MORNING WITH OCNL MVFR CEILINGS. TEMPERATURE
PROFILES COOL ENOUGH FOR SNOW SHOWERS AT SLK. EXPECT OCCASIONAL
IFR CONDITIONS AT SLK IN SNOW SHOWERS TILL ABOUT 18Z. VFR
CONDITIONS AT MOST SITES LATER THIS AFTERNOON/TONIGHT...EXCEPT
MVFR PSBL AT TIMES AT SLK/MPV IN LIGHT SNOW SHOWERS.
WINDS BECOMING WEST TO NORTHWEST 10-15KTS WITH GUSTS 20-22KTS TODAY
THEN DIMINISHING TO NORTHWEST AROUND 5 KTS TONIGHT.
OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...
ISOLD TO SCATTERED RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS ARE
EXPECTED INTO THE FIRST HALF OF SUNDAY. MAINLY VFR CONDITIONS IN
THE VALLEYS WITH OCNL MVFR AND BRIEF IFR POSSIBLE AT MPV/SLK IN
ANY SNOW SHOWERS. THEREAFTER...SURFACE HIGH PRESSURE BUILDS IN
FROM THE WEST AND BECOMES REESTABLISHED OVER THE AREA WITH MAINLY
VFR CONDITIONS EXPECTED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...LAHIFF/TABER
SHORT TERM...TABER
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
736 AM EDT SAT OCT 17 2015
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL PRODUCE MUCH BELOW
NORMAL TEMPERATURES ALONG WITH SCATTERED RAIN AND SNOW SHOWERS. SNOW
ACCUMULATIONS OF A DUSTING TO 3 INCHES IS EXPECTED ABOVE 1500
FEET. TEMPERATURES WILL HOLD MAINLY IN THE 30S MOUNTAINS AND 40S
VALLEYS TODAY WITH LOWS IN THE 20S TO MID 30S TONIGHT. SOME AREAS
OF FROST ARE LIKELY IN THE CHAMPLAIN VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 708 AM EDT SATURDAY...HAVE INCREASED HOURLY TEMPS BY 2 TO 4
DEGREES ACROSS PARTS OF THE CHAMPLAIN VALLEY AND NORTHERN/CENTRAL
VT BASED ON CURRENT OBSERVATIONS. CURRENT SURFACE ANALYSIS SHOWS
COLD FRONT ACROSS THE CHAMPLAIN VALLEY WITH WINDS JUST SHIFTING TO
THE WEST AT BURLINGTON,VT. RADAR SHOWS SCATTERED RAIN AND MOUNTAIN
SNOW SHOWERS ACROSS NORTHERN NEW YORK AND INTO PARTS OF NORTHERN
VT. HAVE NOTED SLK HAS 4SM -SHSN WITH A TEMP OF 34F. EXPECTING
SNOWFALL ACCUMULATIONS ABOVE 1500 FEET TODAY OF A DUSTING TO
SEVERAL INCHES POSSIBLE. JUST GOT A REPORT FROM STOWE MOUNTAIN
THAT WET SNOW FLAKES ARE OCCURRING AT 1500 FEET. ALL IS COVERED
WELL IN CURRENT FORECAST....GIVEN THE MAGNITUDE OF COLD AIR
ADVECTION THINKING TEMPERATURES WILL HOLD STEADY OR FALL SLIGHTLY
TODAY. WHITEFACE ALREADY DOWN TO 25F WITH BRISK NORTHWEST WINDS.
WATER VAPOR SHOWS A DEEP MID/UPPER LEVEL TROUGH OF LOW PRESSURE
ACROSS THE NORTHEAST UNITED STATES. SEVERAL DISTURBANCES IN THE
FLOW ALOFT WILL CONTINUE TO IMPACT OUR REGION THROUGH
SUNDAY...WITH AREAS OF RAIN AND SNOW SHOWERS. AS SURFACE LOW
PRESSURE TRACKS INTO NORTHERN MAINE TODAY...EXPECT WINDS TO SHIFT
TO THE NORTHWEST BY 15Z...WHICH WILL HELP REFOCUS PRECIPITATION
ACROSS THE UPSLOPE REGIONS OF THE NORTHERN DACKS AND
CENTRAL/NORTHERN GREEN MOUNTAINS. THE NAM12/BTV 4KM AND HRRR SHOW
FAVORABLE MOISTURE AND WIND DIRECTION FOR TERRAIN DRIVEN UPSLOPE
PRECIPITATION FROM 12Z THROUGH 18Z TODAY. HOWEVER...SOUNDINGS SHOW
DEPTH OF 925MB TO 700MB MOISTURE DECREASES BY 21Z TODAY...AS
NORTHWEST WINDS ADVECT DRIER AIR INTO THE REGION. THIS WILL
DECREASE AREAL COVERAGE OF UPSLOPE PRECIPITATION BY EVENING...WITH
JUST FLURRIES POSSIBLE OVERNIGHT TONIGHT. QPF AMOUNTS VARY GREATLY
DEPENDING UPON THE MODEL WITH LATEST 00Z BTV 4KM SHOWING 0.60 ALL
SNOW AT JAY PEAK WHILE GFS HAS AROUND 0.35...AND THE NAM12 IS ONLY
0.10. GIVEN TRACK OF SURFACE LOW PRESSURE NORTH OF OUR CWA AND
LACK OF ATLANTIC MOISTURE ADVECTING INTO THE SYSTEM WITH NO CLOSED
UPPER LEVELS...THINKING QPF WILL BE ON THE LIGHTER SIDE. AMOUNTS
WILL RANGE FROM A TRACE TO COUPLE HUNDRETHS IN THE VALLEY TO A
0.25 OR SO FROM MOUNT MANSFIELD TO JAY PEAK...AND SIMILAR ACROSS
THE NORTHERN DACKS. AT 12Z THIS MORNING THERMAL PROFILES SHOW SNOW
LEVELS AROUND 1800 FEET ACROSS THE DACKS AND NEAR 2200 FEET IN THE
CENTRAL GREENS...BUT WITH STRONG LOW LEVEL COLD AIR ADVECTION ON
BRISK NORTHWEST WINDS...THERMAL PROFILES CONTINUE TO COOL...WITH
SNOW LEVELS DROPPING AROUND 1500 FEET BY MIDDAY. BOUNDARY LAYER
TEMPS BETWEEN 3 AND 4C AND LACK OF SIGNIFICANT MOISTURE IN THE
CHAMPLAIN VALLEY WILL LIMIT SNOW ACCUMULATION...MAYBE A FEW WET
SNOW FLAKES WITH THE HEAVIER SHOWERS. THINKING ACCUMULATIONS WILL
RANGE FROM 2 TO 4 INCHES SUMMITS OF THE DACKS AND THE NORTHERN
GREEN MOUNTAINS FROM JAY PEAK TO SUGARBUSH TO A DUSTING TO 2
INCHES HIGHER MOUNTAIN VALLEYS ABOVE 1500 FEET. TEMPS WILL RANGE
FROM THE MID/UPPER 20S SUMMITS TO LOWER/MID 40S CHAMPLAIN VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 345 AM EDT SATURDAY...FORECAST CONCERN TONIGHT WILL BE
TEMPERATURES AND POTENTIAL FOR FREEZE IN THE CHAMPLAIN VALLEY
WHERE THE GROWING SEASON CONTINUES. HAVE NOTED ON SOUNDING STRONG
BOUNDARY LAYER MIXING WITH WINDS OF 5 TO 10 KNOTS EXPECTED AS
REGION IS UNDER LOW LEVEL COLD AIR ADVECTION ON NORTHWEST FLOW.
ALSO...WITH DEEP MID/UPPER LEVEL TROUGH...COLD AIR ALOFT..AND WARM
LAKE CHAMPLAIN WATER...EXPECT SOME CLOUDS ACROSS THE CHAMPLAIN
VALLEY...HOLDING TEMPERATURES IN THE UPPER 20S TO MID 30SNEAR THE
LAKE. GIVEN THE CONDITIONS ABOVE...NOT THINKING A FROST WILL
DEVELOP...BUT MORE ALONG THE LINES OF A FREEZE...BUT WILL LET DAY
SHIFT DECIDE ON ANY POTENTIAL HEADLINES. ELSEWHERE...TEMPERATURES
WILL RANGE FROM THE UPPER TEENS MOUNTAIN SUMMITS TO MID 20S SAINT
LAWRENCE VALLEY AND PARTS OF CENTRAL VT. A FEW LEFTOVER MOUNTAIN
FLURRIES WILL BE POSSIBLE...BUT MOISTURE PROGGES ARE VERY DRY SO
ANY PRECIPITATION WILL BE LIGHT.
SUNDAY WILL FEATURE MID/UPPER LEVEL TROF WITH THE CORE OF THE
COLDEST AIR DIRECTLY OVERHEAD. THIS WILL RESULT IN THE COLDEST DAY
OF WEEKEND...WITH PROGGED 850MB TEMPERATURES BETWEEN -8C AND -10C.
THESE PROFILES WITH BRISK NORTHWEST WINDS OF 10 TO 20 KNOTS WILL
RESULT IN HIGHS ONLY IN THE UPPER 20S TO LOWER 30S MOUNTAIN TOWNS TO
NEAR 40F CHAMPLAIN AND SAINT LAWRENCE VALLEYS. SOUNDINGS SHOW VERY
STEEP LOW LEVEL LAPSE RATES OVER THE MOUNTAINS WITH SOME AVAILABLE
MOISTURE BETWEEN 900MB AND 700MB. THIS INSTABILITY...MOISTURE...AND
UPSLOPE FLOW SHOULD BE ENOUGH TO SUPPORT CONVECTIVE TYPE SNOW
SHOWERS...ESPECIALLY IN THE MOUNTAINS. GIVEN THESE INGREDIENTS WILL
MENTION HIGH CHANCE POPS IN THE MOUNTAINS AND SLIGHT CHANCE IN THE
VALLEYS FOR SUNDAY AFTERNOON...WITH A QUICK DUSTING TO 1 INCH
POSSIBLE IN THE HEAVIER CONVECTIVE ELEMENTS OVER THE MOUNTAINS.
SUNDAY NIGHT WILL BE THE COLDEST NIGHT OF THE SEASON FOR ALL
LOCATIONS ACROSS THE NORTH COUNTRY. 1030MB HIGH PRESSURE AXIS WILL
BE DIRECTLY OVERHEAD WITH PROGGED 850MB TEMPS NEAR -10C. THIS WILL
RESULT IN CLEAR SKIES AND LIGHT WINDS WITH TEMPERATURES RANGING FROM
NEAR 10F SLK/COLDER VALLEYS OF THE NORTHEAST KINGDOM TO MID/UPPER
TEENS MOUNTAIN TOWNS TO LOWER/MID 20S CHAMPLAIN/SAINT LAWRENCE
VALLEYS. A WIDESPREAD FROST IS EXPECTED ON SUNDAY NIGHT/MONDAY
MORNING ACROSS THE ENTIRE CHAMPLAIN VALLEY.
TEMPERATURES WILL REBOUND QUICKLY ON MONDAY WITH DEVELOPING
SOUTHWEST FLOW AND WARM AIR ADVECTION. PROGGED 850MB TEMPS WARM TO
NEAR 0C BY 00Z TUESDAY...PRODUCING HIGHS BACK INTO THE UPPER 30S
MOUNTAINS TO UPPER 40S WARMER VALLEYS. DRY CONDITIONS WILL PREVAIL
WITH BUILDING RIDGE ALOFT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 410 AM EDT SATURDAY...DEEP SOUTHWESTERLY FLOW PREVAILS ACROSS
NORTH COUNTRY MONDAY NIGHT IN ADVANCE OF SHORTWAVE AND ASSOCIATED
COLD FRONT APPROACHING FROM THE NORTHERN GREAT LAKES REGION.
EXPECT INCREASING CLOUDS OVERNIGHT WITH A CHANCE OF SHOWERS AFTER
MIDNIGHT...MAINLY ACROSS NORTHERN AREAS. CHANCE OF SHOWERS
AREAWIDE ON TUESDAY AS THE SHORTWAVE PASSES TO OUR NORTH AND COLD
FRONT WEAKENS WHILE DEPRESSING SOUTH ACROSS FORECAST AREA. DRIER
CONDITIONS FOR TUESDAY NIGHT INTO WEDNESDAY AS HIGH PRESSURE
ATTEMPTS TO BUILD BACK INTO THE REGION FROM THE NORTH. GFS AND
ECMWF THEN GO THEIR SEPARATE WAYS FOR LATER IN THE WEEK. GFS
MAINTAINS HIGH PRESSURE OVER THE AREA FOR MOST OF THE PERIOD WHILE
ECMWF CONTINUES TO SUGGEST THAT A DISTURBANCE WILL DEEPEN WHILE
MOVING SOUTHEAST FROM ONTARIO. HAVE STAYED CLOSE TO OUR EARLIER
FORECAST WHICH INCLUDED CHANCE OF SHOWERS WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...ALTHOUGH THIS FORECAST CONTAINS A HIGH DEGREE OF
UNCERTAINTY. DRIER CONDITIONS THEN EXPECTED FOR FRIDAY WHICH BOTH
GFS AND ECMWF SUGGEST WOULD CONTINUE INTO NEXT WEEKEND. MAX
TEMPERATURES EACH DAY MOSTLY IN THE 50S IN THE VALLEYS...WITHIN A
FEW DEGREES OF NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 12Z SUNDAY...TROUGH OF LOW PRESSURE WILL BRING LIGHT RAIN
SHOWERS TO THE AREA THIS MORNING WITH OCNL MVFR CEILINGS. TEMPERATURE
PROFILES COOL ENOUGH FOR SNOW SHOWERS AT SLK. EXPECT OCCASIONAL
IFR CONDITIONS AT SLK IN SNOW SHOWERS TILL ABOUT 18Z. VFR
CONDITIONS AT MOST SITES LATER THIS AFTERNOON/TONIGHT...EXCEPT
MVFR PSBL AT TIMES AT SLK/MPV IN LIGHT SNOW SHOWERS.
WINDS BECOMING WEST TO NORTHWEST 10-15KTS WITH GUSTS 20-22KTS TODAY
THEN DIMINISHING TO NORTHWEST AROUND 5 KTS TONIGHT.
OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...
ISOLD TO SCATTERED RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS ARE
EXPECTED INTO THE FIRST HALF OF SUNDAY. MAINLY VFR CONDITIONS IN
THE VALLEYS WITH OCNL MVFR AND BRIEF IFR POSSIBLE AT MPV/SLK IN
ANY SNOW SHOWERS. THEREAFTER...SURFACE HIGH PRESSURE BUILDS IN
FROM THE WEST AND BECOMES REESTABLISHED OVER THE AREA WITH MAINLY
VFR CONDITIONS EXPECTED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
721 AM EDT SAT OCT 17 2015
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL PRODUCE MUCH BELOW
NORMAL TEMPERATURES ALONG WITH SCATTERED RAIN AND SNOW SHOWERS. SNOW
ACCUMULATIONS OF A DUSTING TO 3 INCHES IS EXPECTED ABOVE 1500
FEET. TEMPERATURES WILL HOLD MAINLY IN THE 30S MOUNTAINS AND 40S
VALLEYS TODAY WITH LOWS IN THE 20S TO MID 30S TONIGHT. SOME AREAS
OF FROST ARE LIKELY IN THE CHAMPLAIN VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 708 AM EDT SATURDAY...HAVE INCREASED HOURLY TEMPS BY 2 TO 4
DEGREES ACROSS PARTS OF THE CHAMPLAIN VALLEY AND NORTHERN/CENTRAL
VT BASED ON CURRENT OBSERVATIONS. CURRENT SURFACE ANALYSIS SHOWS
COLD FRONT ACROSS THE CHAMPLAIN VALLEY WITH WINDS JUST SHIFTING TO
THE WEST AT BURLINGTON,VT. RADAR SHOWS SCATTERED RAIN AND MOUNTAIN
SNOW SHOWERS ACROSS NORTHERN NEW YORK AND INTO PARTS OF NORTHERN
VT. HAVE NOTED SLK HAS 4SM -SHSN WITH A TEMP OF 34F. EXPECTING
SNOWFALL ACCUMULATIONS ABOVE 1500 FEET TODAY OF A DUSTING TO
SEVERAL INCHES POSSIBLE. JUST GOT A REPORT FROM STOWE MOUNTAIN
THAT WET SNOW FLAKES ARE OCCURRING AT 1500 FEET. ALL IS COVERED
WELL IN CURRENT FORECAST....GIVEN THE MAGNITUDE OF COLD AIR
ADVECTION THINKING TEMPERATURES WILL HOLD STEADY OR FALL SLIGHTLY
TODAY. WHITEFACE ALREADY DOWN TO 25F WITH BRISK NORTHWEST WINDS.
WATER VAPOR SHOWS A DEEP MID/UPPER LEVEL TROUGH OF LOW PRESSURE
ACROSS THE NORTHEAST UNITED STATES. SEVERAL DISTURBANCES IN THE
FLOW ALOFT WILL CONTINUE TO IMPACT OUR REGION THROUGH
SUNDAY...WITH AREAS OF RAIN AND SNOW SHOWERS. AS SURFACE LOW
PRESSURE TRACKS INTO NORTHERN MAINE TODAY...EXPECT WINDS TO SHIFT
TO THE NORTHWEST BY 15Z...WHICH WILL HELP REFOCUS PRECIPITATION
ACROSS THE UPSLOPE REGIONS OF THE NORTHERN DACKS AND
CENTRAL/NORTHERN GREEN MOUNTAINS. THE NAM12/BTV 4KM AND HRRR SHOW
FAVORABLE MOISTURE AND WIND DIRECTION FOR TERRAIN DRIVEN UPSLOPE
PRECIPITATION FROM 12Z THROUGH 18Z TODAY. HOWEVER...SOUNDINGS SHOW
DEPTH OF 925MB TO 700MB MOISTURE DECREASES BY 21Z TODAY...AS
NORTHWEST WINDS ADVECT DRIER AIR INTO THE REGION. THIS WILL
DECREASE AREAL COVERAGE OF UPSLOPE PRECIPITATION BY EVENING...WITH
JUST FLURRIES POSSIBLE OVERNIGHT TONIGHT. QPF AMOUNTS VARY GREATLY
DEPENDING UPON THE MODEL WITH LATEST 00Z BTV 4KM SHOWING 0.60 ALL
SNOW AT JAY PEAK WHILE GFS HAS AROUND 0.35...AND THE NAM12 IS ONLY
0.10. GIVEN TRACK OF SURFACE LOW PRESSURE NORTH OF OUR CWA AND
LACK OF ATLANTIC MOISTURE ADVECTING INTO THE SYSTEM WITH NO CLOSED
UPPER LEVELS...THINKING QPF WILL BE ON THE LIGHTER SIDE. AMOUNTS
WILL RANGE FROM A TRACE TO COUPLE HUNDRETHS IN THE VALLEY TO A
0.25 OR SO FROM MOUNT MANSFIELD TO JAY PEAK...AND SIMILAR ACROSS
THE NORTHERN DACKS. AT 12Z THIS MORNING THERMAL PROFILES SHOW SNOW
LEVELS AROUND 1800 FEET ACROSS THE DACKS AND NEAR 2200 FEET IN THE
CENTRAL GREENS...BUT WITH STRONG LOW LEVEL COLD AIR ADVECTION ON
BRISK NORTHWEST WINDS...THERMAL PROFILES CONTINUE TO COOL...WITH
SNOW LEVELS DROPPING AROUND 1500 FEET BY MIDDAY. BOUNDARY LAYER
TEMPS BETWEEN 3 AND 4C AND LACK OF SIGNIFICANT MOISTURE IN THE
CHAMPLAIN VALLEY WILL LIMIT SNOW ACCUMULATION...MAYBE A FEW WET
SNOW FLAKES WITH THE HEAVIER SHOWERS. THINKING ACCUMULATIONS WILL
RANGE FROM 2 TO 4 INCHES SUMMITS OF THE DACKS AND THE NORTHERN
GREEN MOUNTAINS FROM JAY PEAK TO SUGARBUSH TO A DUSTING TO 2
INCHES HIGHER MOUNTAIN VALLEYS ABOVE 1500 FEET. TEMPS WILL RANGE
FROM THE MID/UPPER 20S SUMMITS TO LOWER/MID 40S CHAMPLAIN VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 345 AM EDT SATURDAY...FORECAST CONCERN TONIGHT WILL BE
TEMPERATURES AND POTENTIAL FOR FREEZE IN THE CHAMPLAIN VALLEY
WHERE THE GROWING SEASON CONTINUES. HAVE NOTED ON SOUNDING STRONG
BOUNDARY LAYER MIXING WITH WINDS OF 5 TO 10 KNOTS EXPECTED AS
REGION IS UNDER LOW LEVEL COLD AIR ADVECTION ON NORTHWEST FLOW.
ALSO...WITH DEEP MID/UPPER LEVEL TROUGH...COLD AIR ALOFT..AND WARM
LAKE CHAMPLAIN WATER...EXPECT SOME CLOUDS ACROSS THE CHAMPLAIN
VALLEY...HOLDING TEMPERATURES IN THE UPPER 20S TO MID 30SNEAR THE
LAKE. GIVEN THE CONDITIONS ABOVE...NOT THINKING A FROST WILL
DEVELOP...BUT MORE ALONG THE LINES OF A FREEZE...BUT WILL LET DAY
SHIFT DECIDE ON ANY POTENTIAL HEADLINES. ELSEWHERE...TEMPERATURES
WILL RANGE FROM THE UPPER TEENS MOUNTAIN SUMMITS TO MID 20S SAINT
LAWRENCE VALLEY AND PARTS OF CENTRAL VT. A FEW LEFTOVER MOUNTAIN
FLURRIES WILL BE POSSIBLE...BUT MOISTURE PROGGES ARE VERY DRY SO
ANY PRECIPITATION WILL BE LIGHT.
SUNDAY WILL FEATURE MID/UPPER LEVEL TROF WITH THE CORE OF THE
COLDEST AIR DIRECTLY OVERHEAD. THIS WILL RESULT IN THE COLDEST DAY
OF WEEKEND...WITH PROGGED 850MB TEMPERATURES BETWEEN -8C AND -10C.
THESE PROFILES WITH BRISK NORTHWEST WINDS OF 10 TO 20 KNOTS WILL
RESULT IN HIGHS ONLY IN THE UPPER 20S TO LOWER 30S MOUNTAIN TOWNS TO
NEAR 40F CHAMPLAIN AND SAINT LAWRENCE VALLEYS. SOUNDINGS SHOW VERY
STEEP LOW LEVEL LAPSE RATES OVER THE MOUNTAINS WITH SOME AVAILABLE
MOISTURE BETWEEN 900MB AND 700MB. THIS INSTABILITY...MOISTURE...AND
UPSLOPE FLOW SHOULD BE ENOUGH TO SUPPORT CONVECTIVE TYPE SNOW
SHOWERS...ESPECIALLY IN THE MOUNTAINS. GIVEN THESE INGREDIENTS WILL
MENTION HIGH CHANCE POPS IN THE MOUNTAINS AND SLIGHT CHANCE IN THE
VALLEYS FOR SUNDAY AFTERNOON...WITH A QUICK DUSTING TO 1 INCH
POSSIBLE IN THE HEAVIER CONVECTIVE ELEMENTS OVER THE MOUNTAINS.
SUNDAY NIGHT WILL BE THE COLDEST NIGHT OF THE SEASON FOR ALL
LOCATIONS ACROSS THE NORTH COUNTRY. 1030MB HIGH PRESSURE AXIS WILL
BE DIRECTLY OVERHEAD WITH PROGGED 850MB TEMPS NEAR -10C. THIS WILL
RESULT IN CLEAR SKIES AND LIGHT WINDS WITH TEMPERATURES RANGING FROM
NEAR 10F SLK/COLDER VALLEYS OF THE NORTHEAST KINGDOM TO MID/UPPER
TEENS MOUNTAIN TOWNS TO LOWER/MID 20S CHAMPLAIN/SAINT LAWRENCE
VALLEYS. A WIDESPREAD FROST IS EXPECTED ON SUNDAY NIGHT/MONDAY
MORNING ACROSS THE ENTIRE CHAMPLAIN VALLEY.
TEMPERATURES WILL REBOUND QUICKLY ON MONDAY WITH DEVELOPING
SOUTHWEST FLOW AND WARM AIR ADVECTION. PROGGED 850MB TEMPS WARM TO
NEAR 0C BY 00Z TUESDAY...PRODUCING HIGHS BACK INTO THE UPPER 30S
MOUNTAINS TO UPPER 40S WARMER VALLEYS. DRY CONDITIONS WILL PREVAIL
WITH BUILDING RIDGE ALOFT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 410 AM EDT SATURDAY...DEEP SOUTHWESTERLY FLOW PREVAILS ACROSS
NORTH COUNTRY MONDAY NIGHT IN ADVANCE OF SHORTWAVE AND ASSOCIATED
COLD FRONT APPROACHING FROM THE NORTHERN GREAT LAKES REGION.
EXPECT INCREASING CLOUDS OVERNIGHT WITH A CHANCE OF SHOWERS AFTER
MIDNIGHT...MAINLY ACROSS NORTHERN AREAS. CHANCE OF SHOWERS
AREAWIDE ON TUESDAY AS THE SHORTWAVE PASSES TO OUR NORTH AND COLD
FRONT WEAKENS WHILE DEPRESSING SOUTH ACROSS FORECAST AREA. DRIER
CONDITIONS FOR TUESDAY NIGHT INTO WEDNESDAY AS HIGH PRESSURE
ATTEMPTS TO BUILD BACK INTO THE REGION FROM THE NORTH. GFS AND
ECMWF THEN GO THEIR SEPARATE WAYS FOR LATER IN THE WEEK. GFS
MAINTAINS HIGH PRESSURE OVER THE AREA FOR MOST OF THE PERIOD WHILE
ECMWF CONTINUES TO SUGGEST THAT A DISTURBANCE WILL DEEPEN WHILE
MOVING SOUTHEAST FROM ONTARIO. HAVE STAYED CLOSE TO OUR EARLIER
FORECAST WHICH INCLUDED CHANCE OF SHOWERS WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...ALTHOUGH THIS FORECAST CONTAINS A HIGH DEGREE OF
UNCERTAINTY. DRIER CONDITIONS THEN EXPECTED FOR FRIDAY WHICH BOTH
GFS AND ECMWF SUGGEST WOULD CONTINUE INTO NEXT WEEKEND. MAX
TEMPERATURES EACH DAY MOSTLY IN THE 50S IN THE VALLEYS...WITHIN A
FEW DEGREES OF NORMAL.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY....AS TROUGH OF LOW PRESSURE MOVES INTO THE
REGION IT WILL BRING LIGHT RAIN SHOWERS TO THE AREA OVERNIGHT WITH
OCNL MVFR CEILINGS. ALSO...TEMPERATURE PROFILES COOL SUFFICIENTLY
FOR A CHANGE TO SNOW SHOWERS AT SLK BETWEEN 08-12Z. COULD SEE
OCCASIONAL IFR CONDITIONS AT SLK DURING SNOW SHOWERS BTWN 10-18Z.
WINDS BECOMING SOUTHWEST 5-10KTS OVERNIGHT THEN WEST TO NORTHWEST
10-15KTS WITH GUSTS 20-22KTS DURING SATURDAY.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
ISOLD TO SCATTERED RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS ARE
EXPECTED INTO THE FIRST HALF OF SUNDAY. MAINLY VFR CONDITIONS IN
THE VALLEYS WITH OCNL MVFR AND BRIEF IFR POSSIBLE AT MPV/SLK IN
ANY SNOW SHOWERS. THEREAFTER...SURFACE HIGH PRESSURE BUILDS IN
FROM THE WEST AND BECOMES REESTABLISHED OVER THE AREA WITH MAINLY
VFR CONDITIONS EXPECTED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
917 AM EDT SAT OCT 17 2015
.SYNOPSIS...A REINFORCING COLD FRONT WILL MOVE THROUGH THE AREA
TONIGHT. COLD HIGH PRESSURE WILL BUILD INTO THE REGION AND SETTLE
ACROSS THE AREA SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 915 AM SATURDAY...
A BAND OF HIGH SC AND LOW AC WAS LOCATED OVER THE FAR SOUTHEAST PART
OF CENTRAL NORTH CAROLINA EARLY THIS MORNING...IN CENTRAL NORTH
CAROLINA SOUTH OF KCTZ TOWARD HARRELLS. ASSOCIATED WITH A SHALLOW
VOLUME OF MOISTURE AROUND 800MB...THE RAP SUGGESTS THAT 800MB
MOISTURE MOVES OFF TO THE SOUTHEAST THIS MORNING...AND RAP SOUNDINGS
FROM NEAR KFAY FORECAST DRYING AROUND 800MB THIS MORNING AND INTO
THE AFTERNOON. OTHERWISE...AHEAD OF A MID-LEVEL TROUGH SHOWN ON
WATER VAPOR IMAGERY MOVING EAST TOWARD THE CAROLINAS...WHILE THERE
SHOULD BE UPPER-LEVEL DIFFLUENCE TODAY THE WATER VAPOR IMAGERY SHOWS
GOOD DRY AIR OVER CENTRAL NORTH CAROLINA AND RAP SOUNDINGS INDICATE
CONSIDERABLE DRY AIR IN THE COLUMN. K INDICES ARE NEGATIVE...AND
850MB THETA-E VALUES DECREASE DURING THE DAY...ESPECIALLY SOUTHEAST.
WITH MIXING...THE 12Z GSO AND RAP FORECAST SOUNDINGS SUGGEST A FEW
GUSTS POSSIBLE AROUND 15KT...ESPECIALLY TOWARD THE TRIAD AND
TRIANGLE. 1000-850MB THICKNESSES AND THE TEMPERATURE FORECAST FROM
THOSE COINCIDE WITH THE CONSENSUS OF MOS GUIDANCE...MID TO UPPER 60S
IN THE NORTHWEST PIEDMONT AND MOSTLY AROUND 70 ELSEWHERE...SOLID
LOWER 70S TOWARD KFAY AND KCTZ.
TONIGHT...A SECONDARY REINFORCING COLD IS EXPECTED TO MOVE THROUGH
THE AREA THIS EVENING INTO TONIGHT... AS ANOTHER S/W IN THE L/W
TROUGH MOVES ACROSS THE NORTHEAST U.S. THE FRONT SHOULD BE DRY AND
ONLY DELIVER A COLDER/DRIER AIRMASS TO CENTRAL NC...ALONG WITH AND
INCREASE IN WINDS THIS EVENING INTO EARLY SUNDAY MORNING. WINDS WILL
BEGIN TO WEAKEN CLOSER TO DAYBREAK SUNDAY ACROSS THE NORTHERN PART
OF THE CWA. HOWEVER...WITH EXPECTED LOW TEMPS A BIT WARMER THAN
PREVIOUS FORECASTS AND DEWPOINT DEPRESSIONS EXPECTED TO BE A BIT
HIGHER WILL NOT ISSUE A FROST ADVISORY AT THIS TIME. LOW TEMPS ARE
EXPECTED TO RANGE FROM THE MID TO UPPER 30S...WITH A FEW LOCATIONS
ACROSS THE SOUTH/SOUTHEAST NEAR 40. EXPECT SOME OF THE MORE
SHELTERED RURAL USUAL COLD LOCATIONS ACROSS THE NORTH MAY SEE SOME
PATCHY FROST THOUGH.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM SATURDAY...
CANADIAN HIGH PRESSURE WILL BUILD ACROSS THE REGION ON SUNDAY INTO
SUNDAY NIGHT IN THE WAKE OF THE COLD FRONT. THIS WILL USHER IN MUCH
COOLER/COLDER AIR INTO CENTRAL NC. DESPITE SUNNY SKIES... HIGH TEMPS
WILL STRUGGLE TO REACH 60 DEGREES. EXPECT HIGH TEMPS WILL RANGE FROM
THE MID TO UPPER 50S... WITH A FEW LOCATIONS ACROSS FAR SOUTHERN
PORTIONS OF CENTRAL NC TOUCHING 60 DEGREES SUNDAY AFTERNOON. WITH
THE PRESSURE GRADIENT WEAKENING OVER THE AREA NEAR DAYBREAK MONDAY
MORNING WE WILL LIKELY SEE THE COLDEST TEMPS OF THE SEASON TO DATE.
LOW TEMPS BY MONDAY MORNING ARE EXPECTED TO BE IN LOW TO MID 30S. AT
LEAST A FROST ADVISORY SEEMS LIKELY AREAWIDE FUTURE FORECASTS...
WITH POTENTIALLY EVEN A FREEZE WARNING ACROSS THE PIEDMONT AND
NORTHERN COASTAL PLAIN.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...
DRY WEATHER WEATHER WILL PERSIST THROUGH THE LONG TERM AS BROAD/FLAT
UPPER LEVEL RIDGE CONTINUES OVER THE DEEP SOUTH THROUGH THE TN
VALLEY...AND ASSOCIATED SFC RIDGE EXTENDS SW-NE ACROSS CENTRAL NC.
LOW LEVEL THICKNESSES AT THE START OF THE PERIOD AVERAGE A SOLID 30-
35M BELOW NORMAL...YIELDING MAX TEMPS MONDAY IN THE 50S TO AROUND
60. AIR MASS MODIFIES TUESDAY THROUGH WEDNESDAY WITH TEMPS RETURNING
TO NEAR NORMAL LEVELS (UPPER 60S-LOWER 70S) BY MID WEEK.
UPPER RIDGE AMPLIFIES FROM THE DEEP SOUTH INTO THE LOWER GREAT LAKES
THURSDAY INTO FRIDAY IN RESPONSE TO A DEEPENING UPPER LEVEL LOW OVER
THE DESERT SW. THIS WILL CAUSE OUR UPPER LEVEL FLOW TO BECOME NWLY.
THIS SET-UP WILL CAUSE A S/W TO CROSS SOUTHERN NEW ENGLAND-NORTHERN
MID ATLANTIC THURSDAY. THIS FEATURE WILL PROPEL A SURFACE COLD FRONT
SEWD INTO CENTRAL NC THURSDAY NIGHT THROUGH FRIDAY MORNING. MODEL
GUIDANCE HAS BEEN FAIRLY CONSISTENT WITH THE TIMING OF THIS SURFACE
FEATURE.
MOISTURE ADVECTION AHEAD OF THE SFC FRONT THURSDAY NIGHT IS WEAK AT
BEST SO EXPECT NOTHING MORE THAN PATCHY CLOUDINESS ASSOCIATED WITH
THE FRONTAL PASSAGE. NLY FLOW BEHIND THE FRONT WILL USHER IN A FRESH
BATCH OF COOLER AIR FOR THE WEEKEND.
EXPECT THURSDAY TO BE THE WARMEST DAY IN THE UPCOMING WEEK AS
THICKNESSES AVERAGE 5-8M ABOVE NORMAL SUPPORTIVE OF AFTERNOON TEMPS
IN THE 70-75 DEGREE RANGE. A SLIGHT COOL DOWN EXPECTED FRIDAY AS SFC
FLOW BEGINS TO ADVECT THE COOLER AIR MASS INTO THE REGION.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
AS OF 915 AM SATURDAY...
24-HR TAF PERIOD: VFR CONDITIONS ARE EXPECTED THROUGH THE 24 HOUR
TAF PERIOD AS A HIGH PRESSURE EXTENDS INTO THE AREA AHEAD OF ANOTHER
COLD FRONT...WHICH IS PROGGED TO CROSS THE AREA THIS EVENING INTO
TONIGHT. SUSTAINED WINDS WILL GENERALLY BE OUT OF THE NORTHWEST TO
NORTH DURING THE PERIOD...FROM 7 TO 12 MPH FROM MID MORNING UNTIL
LATE EVENING/EARLY SUNDAY MORNING. THERE SHOULD BE A FEW DAYTIME
GUSTS IN THE TEENS MPH TODAY. DRIER AIR ADVECTING INTO THE AREA
BEHIND THE FRONT SHOULD PREVENT ANY SUB-VFR CONDITIONS DURING THE
PRE-DAWN HOURS OF SUNDAY.
OUTLOOK: VFR CONDITIONS ARE EXPECTED TO RULE THROUGH THE MAJORITY OF
NEXT WEEK AS CANADIAN HIGH PRESSURE SETTLES DIRECTLY OVER THE
REGION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...77
NEAR TERM...DJF/77
SHORT TERM...77
LONG TERM...WSS
AVIATION...77/DJF/VINCENT
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
953 AM EDT SAT OCT 17 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE MIDWEST WILL PUSH EAST ACROSS
OHIO SUNDAY AND TO THE EAST COAST MONDAY. A COLD FRONT WILL DROP
SOUTHEAST TO NEAR LAKE ERIE BY TUESDAY NIGHT AND STALL. LOW PRESSURE
WILL MOVE EAST ALONG THE FRONT TO LAKE ONTARIO BY THURSDAY MORNING
PULLING THE FRONT SOUTHEAST ACROSS THE AREA. HIGH PRESSURE WILL
BUILD SOUTHEAST INTO LAKE ERIE BY FRIDAY THEN SLOWLY SHIFT INTO NEW
ENGLAND ON THE WEEKEND.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
CURRENT FORECAST LOOKS REASONABLE SO ONLY MINOR CHANGES ARE
PLANNED FOR THE DAY AS AN UNSEASONABLY COOL DAY IS EXPECTED ALONG
WITH LAKE EFFECT SHOWERS IN THE SNOWBELT. ANOTHER SHORT WAVE IS
EXPECTED TO DIG SOUTHEAST ACROSS THE REGION TODAY AND HELP PRODUCE
UPWARD MOTION ESPECIALLY OVER AND DOWNWIND OF LAKE ERIE. 12 UTC
SOUNDING AT DTX SHOWS A WELL MIXED LAYER TO 6500 FT AND RADAR
MOSAIC SHOWS CONVECTION MOVING FROM LAKE HURON SOUTHEAST ACROSS
LAKE ERIE TOWARD AND OVER NE OHIO AND NW PA. THE HRRR AND OTHER
CONVECTION ALLOWING MODELS CONTINUE THIS ACTIVITY TODAY WHICH IS
REASONABLE. SO WE WILL CONTINUE THE HIGH POPS IN THAT REGION. IT
SHOULD WARM ENOUGH THAT ANY MIXED PRECIPITATION SHOULD BE ALL
LIQUID THIS AFTERNOON.
CURRENT TEMPERATURE FORECAST LOOK ON TRACK FOR TODAY SO NO CHANGES
PLANNED.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE LAST
REINFORCING FRONT/TROUGH WILL DROP SE INTO THE CWA BY DAYBREAK.
EXPECT LAKE ENHANCED SHRA...MIXED WITH GRAUPEL AND SNOW TO REMAIN
LIKELY IN THE SNOWBELT INTO SUNDAY THEN START TO LESSEN AND SHIFT
EAST AS HIGH PRESSURE FINALLY PUSHES EAST OVER OHIO BY SUN EVENING.
THE COLDEST AIR ALOFT WILL BE OVER THE AREA TONIGHT SO WILL HAVE THE
BEST SHOT AT SEEING MORE SNOW MIXED IN SO HAVE ACCUMULATION UP TO AN
INCH FOR INLAND NW PA TONIGHT INTO SUN MORNING. SINCE MOST OF THE
PRECIP SHOULD BE RAIN...SOME AREAS IN NW PA COULD SEE AN INCH OR SO
OF RAINFALL LOCALLY FROM SAT INTO SUN BUT THIS SHOULDN`T CAUSE
FLOODING PROBLEMS.
ONCE AGAIN THERE IS UNCERTAINTY AS TO HOW FAR SW THE CLOUD COVER
WILL BE TONIGHT AND HOW THIS WILL AFFECT WHO SEES FREEZING TEMPS.
SHOULD HAVE ENOUGH OF A LACK OF CLOUDS FOR THE SW HALF TO SEE
FREEZING TEMPS TONIGHT. ALSO...IN THE NORMALLY COLDER AREAS IN THE
INLAND EAST DON`T SEE TEMPS GETTING DOWN BELOW FREEZING IF THE
CLOUDS REMAIN AS EXPECTED. WILL LET BEST COLLABORATION DETERMINE
WHETHER ANY FREEZE HEADLINES WILL BE ISSUED FOR THAT AREA. SINCE WE
ARE RUNNING ONLY ONE HEADLINE FOR FROST/FREEZE AT A TIME...WE WILL
EVALUATE THE SITUATION AFTER THIS MORNING`S HEADLINE EXPIRES AT 9 AM
AND DETERMINE COURSE OF ACTION FOR TONIGHT.
WITH MORE SUNSHINE WEST AND CENTRAL ON SUN SHOULD SEE HIGHS START TO
MODERATE A FEW DEGREES WARMER WHILE NW PA LIKELY SEE LITTLE CHANGE.
THE HIGH CROSSES THE AREA SUN NIGHT PROVIDING DRY CONDITIONS AFTER A
FEW POSSIBLE LINGERING EVENING SHRA IN THE FAR EAST. THIS WILL
LIKELY BE THE COLDEST NIGHT IN THE EAST PART OF THE CWA DUE TO
CLEARING SKIES AND LIGHT WINDS SO MAY HAVE MORE FREEZE HEADLINES TO
PUT OUT FOR THIS.
INCREASING SOUTH TO SW WINDS ON MON WILL FINALLY BRING WARMER AIR
INTO THE AREA WITH HIGHS GETTING BACK CLOSE TO NORMAL AND MAYBE EVEN
A FEW DEGREES ABOVE NORMAL BY TUE AS THE RELATIVELY WARM FLOW
CONTINUES. HELPING TO BUFFER DOWN THE HIGHS ON TUE WILL BE ADDED
WARM ADVECTION CLOUDS AIDED BY A WEAK UPPER S/W MOVING EAST THRU THE
LAKES WHICH ALSO ACTS TO BRING A COLD FRONT SE TO NEAR LAKE ERIE BY
TUE NIGHT. COULD SEE A FEW ISOLATED SHRA AS FAR SOUTH AS LAKE ERIE
BY LATE MON NIGHT BUT A LITTLE BETTER CHC WILL OCCUR ON TUE AND EVEN
MORE SO TUE NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
NOT MANY CHANGES TO THE LONG TERM THIS MORNING. IT STILL LOOKS
LIKE MOST OF THE PRECIP ON WEDNESDAY WILL REMAIN NORTH OF THE AREA
AS THE FRONTAL BOUNDARY MOVES BACK NORTH. BETTER CHANCES FOR
PRECIP WILL COME WEDNESDAY NIGHT AS THE FRONT SAGS SOUTHEAST
ACROSS THE AREA. WILL SEE SOME LINGERING INSTABILITY SHOWERS IN
THE EAST INTO THURSDAY BUT THE REMAINDER OF THE PERIOD WILL BE DRY
AFTER THAT. WEDNESDAY WILL BE A WARM DAY AND EVEN THURSDAY AND
FRIDAY WILL AVERAGE A LITTLE ABOVE NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
LOT`S OF CLOUDS REMAIN ACROSS THE AREA THIS MORNING. JUST ONE
NARROW AREA OF CLEAR SKIES REMAIN AS CLOUDS HAVE MOVED BACK OVER
NW OHIO. GIVEN THE COLD AIR ALOFT EXPECT BKN TO OVC CIGS ALL DAY
MOST AREAS. THE PRECIP IS CURRENTLY LIMITED BUT THE LATEST
GUIDANCE COMING IN CONTINUES TO SHOW IT BLOSSOMING OVER NE OH AND
NW PA LATER THIS MORNING. CIGS SHOULD REMAIN VFR EXCEPT IN THE
STEADIER PRECIP. EXPECT SKIES TO SCATTER OUT FROM WEST TO EAST
TONIGHT. W TO NW FLOW WILL INCREASE AS THE SUN COMES UP WITH GUSTS
TO 20 KNOTS LIKELY MOST AREAS BY MIDDAY. WINDS WILL DIMINISH AFTER
00Z.
.OUTLOOK...NON-VFR POSSIBLE MAINLY NE OH AND NW PA INTO SUNDAY.
&&
.MARINE...
WINDS HAVE COME DOWN SLIGHTLY BUT STILL SEEING A LOT OF
SPEEDS IN THE UPPER TEENS SO WILL LEAVE THE SMALL CRAFT HEADLINES GO
AS PLANNED. PER COORDINATION WITH BUF WILL GO AHEAD AN ADD A
WATERSPOUT MENTION TO THE LAKE FOR TODAY GIVEN THE INSTABILITY. NOT
EXPECTING THE COLD AIR TYPE FUNNELS GIVEN THE WINDS SPEEDS BUT ANY
OF THE STRONGER CONVECTION ON THE LAKE COULD PRODUCE A SPOUT. BEST
CHANCES FOR THIS WILL BE IN THE EAST. TROUGHINESS WILL REMAIN ON
THE LAKE THROUGH SUNDAY SO MORE PRECIP IS POSSIBLE THEN.
HOWEVER...WIND SPEEDS WILL BEGIN TO COME DOWN AS HIGH PRESSURE
BUILDS IN FROM THE SOUTHWEST. BY SUNDAY EVENING SPEEDS SHOULD BE
UNDER 10 KNOTS ALL AREAS WITH SOUTHERLY FLOW DEVELOPING ON MONDAY.
A PRETTY STRONG PRESSURE GRADIENT WILL GET ESTABLISHED EARLY IN THE
WORKWEEK SO MAY EVENTUALLY NEED MORE SMALL CRAFT HEADLINES IN THE
STRONG SOUTH TO SOUTHWEST FLOW. THIS FLOW WILL CONTINUE TO A
FRONTAL BOUNDARY STALLS OUT NEAR THE LAKE SOMETIME LATE TUESDAY OR
EARLY WEDNESDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ145>149.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LEZ144.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...LAPLANTE
SHORT TERM...ADAMS
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
130 PM MST SAT OCT 17 2015
&&
.SYNOPSIS...
A SERIES OF SLOW MOVING LOW PRESSURE SYSTEMS WILL BRING ELEVATED
CHANCES OF SHOWERS AND THUNDERSTORMS TO THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. SHOWERS AND STORMS ARE POSSIBLE ACROSS SOUTH
CENTRAL AZ TONIGHT AND SUNDAY AS THE FIRST LOW PRESSURE SYSTEM
PASSES ACROSS THE REGION...WITH A MODEST DRYING TREND ON MONDAY
THIS WILL BE SHORT LIVED HOWEVER AS A SECOND LOW MOVES INTO THE
DESERT SOUTHWEST ON TUESDAY AND REMAINS IN PLACE THROUGH THURSDAY.
DRIER AIR WILL THEN MOVE INTO THE AREA LATE NEXT WEEK.
&&
.DISCUSSION...
.TONIGHT THROUGH MONDAY... THE UPPER LOW...WHICH HAS NOW WEAKENED
INTO AN OPEN WAVE...IS NOW STEADILY MOVING EASTWARD ACROSS WESTERN AZ
THIS HOUR. AHEAD OF THE TROF AXIS...AN AREA OF SCATTERED SHOWERS AND
THUNDERSTORMS IS NOW MOVING ACROSS THE GREATER PHOENIX AREA.
ALTHOUGH A FEW AREAS HAVE/WILL LIKELY SEEN BRIEF HEAVY
DOWNPOURS...WITH 88D RADAR RAINFALL ESTIMATES OF OVER 1/2 INCH IN A
FEW ISOLATED SPOTS...MOST OF THE STORMS HAVE/WILL LIKELY BEEN MUCH
WEAKER THEN WHAT WE SAW YESTERDAY...DUE TO LESS AVAILABLE MOISTURE
AND SHEAR THROUGH THE COLUMN. BEHIND THIS CURRENT LINE OF STORMS...A
CLEARING TREND CAN BE SEEN ON SATELLITE IMAGERY OVER WESTERN AZ AS
DRIER AIR MOVES INTO THE REGION. HOWEVER...HAVE DECIDED TO LEAVE
CHANCE POPS IN THE GRIDS ACROSS SOUTH-CENTRAL AZ THROUGH THIS
EVENING SINCE THE HRRR HIGH-RES MODEL CONTINUES TO SHOW SOME EARLY
EVENING ACTIVITY...LIKELY BEING TRIGGERED BY OUTFLOWS FROM
THUNDERSTORMS THAT ARE FORECAST TO DEVELOP OVER THE TUCSON AREA.
MUCH OF SUNDAY LOOKS LIKE IT WILL BE DRY IN MOST AREAS...ALTHOUGH
THE COMBINATION OF LINGERING MOISTURE AND UPSLOPE SOUTHWESTERLY FLOW
COULD TRIGGER SOME SHOWER ACTIVITY AGAIN ON SUNDAY AFTERNOON ACROSS
SOUTH-CENTRAL AZ...MAINLY OVER THE HIGHER TERRAIN EAST OF PHOENIX.
MONDAY LOOKS LIKE IT WILL BE EVEN DRIER...AS WEAK SHORTWAVE RIDGING
BUILDS BRIEFLY OVER THE REGION AHEAD OF THE NEXT UPPER TROF. OUTSIDE
OF PERHAPS A FEW SHOWERS OVER THE HIGHER TERRAIN NORTH AND EAST OF
PHOENIX...THE ONLY OTHER PLACE THAT COULD SEE SOME ISOLATED SHOWERS
IS OVER THE HIGHER TERRAIN OF LA PAZ COUNTY...AS LOW-LEVEL SOUTHERLY
FLOW PULLS A SURGE OF MOISTURE NORTHWARD FROM THE GULF OF
CALIFORNIA. HIGH TEMPERATURES ON SUNDAY AND MONDAY APPEAR THAT THEY
WILL BE NEAR...OR JUST SLIGHTLY ABOVE NORMAL.
.TUESDAY THROUGH THURSDAY...
FURTHER COOLING...AND ANOTHER CHANCE FOR RAINFALL APPEARS TO BE ON
THE WAY FOR THIS TIME PERIOD. THE GFS...EURO...AND MANY OF THEIR
EMSEMBLE MEMBERS ARE NOW SHOWING A RATHER DEEP UPPER TROF DIGGING
SOUTHEASTWARD INTO THE LOWER COLORADO RIVER VALLEY BY LATE
TUESDAY...THEN WOBBLING VERY SLOWLY EASTWARD ACROSS SOUTHERN AZ ON
WEDNESDAY AND THURSDAY AS IT TEMPORARILY GETS CUT OFF FOR THE MAIN
POLAR JET. ALTHOUGH THIS SYSTEM WILL BE A PRETTY DYNAMIC ONE...WITH
COLDER AIR ALOFT (500MB TEMPS IN THE -15C TO -16C RANGE) THAN WHAT
WE ARE SEEING WITH THE CURRENT SYSTEM...MOISTURE WITH THIS NEW
SYSTEM APPEARS IT WILL BE MORE LIMITED...WITH PWATS MAINLY IN THE
0.70-1.00 INCH RANGE AT MOST...WHICH IS LIKELY DUE TO THE SYSTEM/S
MORE NORTHERLY ORIGIN OVER THE NE PACIFIC...WHICH WILL LIKELY LIMIT
RAINFALL CHANCES/COVERAGE. STILL...IT APPEARS THAT SHOWER CHANCES
WILL BE AT LEAST IN THE CHANCE-LIKELY RANGE...WITH THE BEST CHANCES
BEING LATE TUESDAY/EARLY WEDNESDAY OVER SOUTH-CENTRAL AZ. ALONG WITH
THE RETURN OF SHOWER CHANCES...IT APPEARS TEMPERATURES WILL LIKELY
FALL BELOW NORMAL DURING THIS PERIOD...WITH THE CONSENSUS GUIDANCE
SHOWING LOWER DESERT HIGHS IN THE LOW-MID 80S EACH DAY...WHICH COULD
TURN OUT TO BE EVEN COOLER IF IT TURNS OUT WE GET MORE RAIN/CLOUDS
THEN WE CURRENTLY EXPECT.
FRIDAY AND SATURDAY... AT THIS TIME...IT APPEARS THAT THIS WILL BE A
DRY COUPLE OF DAYS...WITH SLIGHTLY WARMER TEMPERATURES...AS THE MAIN
TROF MOVES OFF TO THE EAST AND FLAT RIDGING BUILDS OVER THE REGION
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
ISOLATED SHOWERS AND GUSTY E/NE SFC WINDS WILL BE THE PRIMARY
AVIATION CONCERNS THROUGH THIS AFTERNOON. AN ISOLD TSRA COULD BE
EMBEDDED WITH THE SHOWERS...HOWEVER COVERAGE LOOKS VERY SPARSE. THE
MOST LIKELY TIME FRAME FOR SCT SHOWERS WILL BE THROUGH 14Z
THIS MORNING...AND THEN AGAIN LATE THIS AFTERNOON AND EARLY EVENING.
SFC WINDS SHOULD MAINTAIN A GENERAL EASTERLY COMPONENT THROUGH THE
PERIOD...THOUGH COULD OCCASIONAL DRIFT BETWEEN NNE AND SE. STRONGER
GUSTS ABOVE 20KT WILL BE LIKELY LATE THIS MORNING/EARLY AFTERNOON.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
DECREASING CHANCES OF SHOWERS AND THUNDERSTORMS TODAY...TOO LIMITED
COVERAGE FOR INCLUDING IN TAFS AT THIS TIME. SHIFTING VARIABLE SFC
WINDS WILL BE COMMON...AND OVERALL CONFIDENCE IN TIMING ANY SPECIFIC
WIND SHIFT IS RATHER LOW.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UNSETTLED WEATHER EARLY NEXT WEEK WILL SLOWLY TRANSITION TO DRIER
CONDITIONS WITH SEVERAL DISTURBANCES PASSING THROUGH THE DISTRICT.
LIGHTER SHOWERS WILL FAVOR HIGHER TERRAIN LOCATIONS OF EASTERN
ARIZONA. AFTERNOON HUMIDITY VALUES IN A 25 TO 35 PERCENT RANGE EARLY
IN THE WEEK WILL ONLY DECREASE TO A 15 TO 25 PERCENT RANGE BY THE
MIDDLE AND END OF NEXT WEEK. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. A FEW STRONGER NORTHERLY WIND GUSTS DOWN THE LOWER
COLORADO RIVER VALLEY WILL BE POSSIBLE TUESDAY AND WEDNESDAY
AFTERNOON. OTHERWISE...WINDS WILL GENERALLY BE LIGHT AND NOT A FIRE
WEATHER IMPACT.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA
AVIATION...KUHLMAN
FIRE WEATHER...DEWEY
AREA FORECAST DISCUSSION
NWS TUCSON AZ
940 AM MST SAT OCT 17 2015
.SYNOPSIS...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL
OCCUR INTO TONIGHT FOLLOWED BY LESS COVERAGE OF SHOWERS AND
THUNDERSTORMS SUNDAY AND ESPECIALLY MONDAY. A LOW PRESSURE SYSTEM
WILL THEN BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY INTO
WEDNESDAY. EXPECT DRY CONDITIONS TO RETURN LATE NEXT WEEK.
&&
.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 30-60 DBZ ECHOES
EXTENDING FROM NEAR SILVER BELL SEWD TO JUST SOUTH OF TUCSON...AND
FURTHER SEWD INTO SWRN COCHISE COUNTY AT THIS TIME. A FEW LIGHTNING
STRIKES WERE DETECTED WITH THE ECHOES AROUND SILVER BELL.
OTHERWISE...IR/VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATED MOSTLY CLOUDY TO CLOUDY SKIES ACROSS SE ARIZONA. A TIGHT
SURFACE PRESSURE GRADIENT HAS PRODUCED A GENERAL ELY/SELY SURFACE
WIND REGIME...AND A WIND GUST OF 34 KTS WAS RECORDED AT KTUS AT
750 AM MST.
A RELATIVELY DRY PERIOD SHOULD OCCUR THE REST OF THIS MORNING.
HOWEVER...17/12Z NAM12...SEVERAL HRRR SOLUTIONS AND THE 17/06Z UNIV
OF ARIZONA WRF-NAM WERE QUITE SIMILAR IN DEPICTING SHOWERS/TSTMS TO
DEVELOP EARLY THIS AFTERNOON. THE FAVORED LOCALES FOR THIS
DEVELOPMENT APPEARS TO BE MAINLY WEST-TO-SOUTH OF TUCSON. THE MID-
LEVEL STEERING FLOW SUPPORTS NELY STORM MOTIONS. SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO OCCUR INTO THIS
EVENING. THE LEAST FAVORED AREA FOR SHOWERS/TSTMS WILL BE ACROSS WRN
PIMA COUNTY.
THERE HAS BEEN A DELAY WITH THE BULK OF THE 17/12Z MODEL SUITE.
THUS...MORE DETAIL TO OCCUR IN THE AFTERNOON DISCUSSION.
OTHERWISE...THERE ARE NO UPDATES NECESSARY AT THIS TIME. PLEASE
REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 18/18Z.
SCATTERED -SHRA THIS MORNING THEN NUMEROUS TSRA/SHRA THIS AFTERNOON
AND EVENING. SCATTERED -SHRA AND ISOLATED -TSRA WILL OCCUR LATE
TONIGHT INTO SUNDAY MORNING ESPECIALLY FROM KTUS VICINITY EASTWARD
TO THE NEW MEXICO BORDER. MVFR CONDITIONS AND BRIEF IFR CONDITIONS
WILL OCCUR AT TIMES INTO SUNDAY MORNING. OTHERWISE...CLOUD DECKS
WILL BE AROUND 8-12K FT AGL AND SURFACE WIND WILL GENERALLY BE
ELY/SELY AT 8-20 KTS WITH GUSTS OF 20-30 KTS. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...SHOWERS AND ISOLATED THUNDERSTORMS TODAY WITH LESS
COVERAGE OF STORMS SUNDAY AND MONDAY. UNSETTLED WEATHER WILL
CONTINUE TUESDAY AND WEDNESDAY WITH ANOTHER CHANCE OF SHOWERS AND
THUNDERSTORMS. DRY CONDITIONS ARE FORECAST TO RETURN BY FRIDAY.
&&
.PREV DISCUSSION /322 AM MST/...THEREAFTER...THE RAIN CHANCES LOWER
SIGNIFICANTLY SUNDAY AND MONDAY. HOWEVER...MORE RAIN WILL BE ON THE
WAY TUESDAY AS ANOTHER SYSTEM DROPS SOUTH INTO SOUTHERN CALIFORNIA
AND THEN HANGS OUT NEAR ARIZONA THROUGH LATE WEDNESDAY OR EARLY
THURSDAY. HIGH TEMPERATURES WILL EVENTUALLY LOWER TO READINGS
SLIGHTLY BELOW NORMAL AROUND TUESDAY AND WEDNESDAY AS THE NEXT
SYSTEM ARRIVES.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
130 PM PDT SAT OCT 17 2015
.SYNOPSIS...
A LOW PRESSURE TROUGH ALONG THE WEST COAST AND MOIST ONSHORE FLOW
WILL CONTINUE WIDESPREAD NIGHT AND MORNING LOW CLOUDS...FOG...AND
PATCHY DRIZZLE WEST OF THE MOUNTAINS...AND A CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE MOUNTAINS AND DESERTS THROUGH TUESDAY. LOW
PRESSURE IS FORECAST TO DEVELOP OVER THE LOWER COLORADO RIVER VALLEY
BY THE MIDDLE OF NEXT WEEK. THIS SHOULD RESULT IN DRYING...AND
WARMER WEATHER INTO NEXT WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
AFTER PARTIAL CLEARING THIS MORNING...LOW CLOUDS RAPIDLY REDEVELOPED
WEST OF THE MTS TODAY. THE LOW CLOUDS WERE WIDESPREAD ACROSS SAN
DIEGO AND ORANGE COUNTIES AT MIDDAY...WHILE THE INLAND EMPIRE WAS
MOSTLY CLEAR. CLOUDS WERE ALSO THICK OVER THE MTN CRESTS AND
OFFSHORE. ISOLATED RADAR ECHOES HAD POPPED BY 1 PM ON THE MTN SLOPES
AND FURTHER DEVELOPMENT IS LIKELY THROUGH EARLY EVENING. SURFACE
PRESSURE GRADIENTS WERE 3 MBS OR LESS TO/FROM THE DESERTS. WINDS
WERE GENERALLY LIGHT.
LATEST HRRR MODEL STILL SHOWS CONSIDERABLE SHWR/TSTM DEVELOPMENT
THIS AFTERNOON ALONG AND JUST WEST OF THE MTS. WITH HIGH SFC
DEWPOINTS IN PLACE AND PW WELL OVER ONE INCH IN MANY AREAS...EXPECT
TO SEE SOME DEVELOPMENT INTO THE EARLY EVENING. AFTER SUNSET...
DEEP MOISTURE IN PLACE SHOULD RESULT IN WIDESPREAD LOW CLOUDS
WITH PATCHY DRIZZLE AND FOG INLAND TO THE COASTAL SLOPES. A FEW
SHOWERS AND ISOLATED THUNDERSTORMS WILL STILL BE POSSIBLE...MAINLY
NEAR THE MTS. LOCALLY HEAVY RAIN IS POSSIBLE. SIMILAR WEATHER IS
EXPECTED ON SUN/MON.
WATER VAPOR IMAGERY SHOWED A STRONG CIRCULATION OFF THE NOCAL COAST
THIS MORNING. THIS SYSTEM WILL DIG SOUTH THROUGH TUE...AND MAY CUT
OFF OVER THE LOWER COLORADO RIVER VALLEY FOR A TIME MIDWEEK. SOME
WRAP AROUND MOISTURE CONTINUES A THREAT OF SHWRS IN THE MTS/DESERTS
THROUGH WED AFTERNOON...OTHERWISE EXPECT DRY WEATHER WITH THE UPPER
LOW IN THIS POSITION. SOME GUSTY OFFSHORE FLOW MAY DEVELOP TUE/WED
OVER NORTHERN PORTIONS OF THE CWA AS WELL...BUT MODELS DO NOT SHOW
IT PERSISTING OR BECOMING WIDESPREAD. RELATIVE HUMIDITY REMAINS
MODERATE AS WELL.
CONFIDENCE LOWERS IN THE EXTENDED PERIOD AS THE GLOBAL MODEL
SOLUTIONS DIVERGE. BASED ON THE LATEST 12Z GFS/ECMWF RUNS...EXPECT
DRY AND SEASONAL...TO SLIGHTLY WARMER THAN AVERAGE WEATHER FOR THE
LATTER HALF OF NEXT WEEK.
&&
.AVIATION...
172030Z...COASTS/VALLEYS...SCATTERED LOW CLOUDS RANGING FROM 1500 FT
MSL TO 3500 FT MSL ARE BANKED UP AGAINST THE COASTAL MOUNTAIN
FOOTHILLS. THESE LOW CLOUDS ARE EXPECTED TO THICKEN AND BECOME
BKN/OVC TONIGHT...FILLING THE COASTAL BASIN. LIGHT DRIZZLE IS
POSSIBLE AFTER AROUND 0600Z. THIS CLOUD DECK WILL ONCE AGAIN
SCATTERED OUT BETWEEN 18/1600Z-1900Z.
MOUNTAINS/DESERTS...SCT CLOUDS IN THE 7000-12000 FT MSL LAYER IN THE
MOUNTAINS. A FEW SHOWERS AND THUNDERSTORMS WILL CONTINUE TO
DEVELOP...MAINLY OVER ELEVATED TERRAIN...THROUGH THIS EVENING.
BASES 5000-8000 FT MSL...TOPS 15000 FT MSL AND CB TOPS TO 35000 FT
MSL. THESE STORMS MAY PRODUCE GUSTY DOWNDRAFT WINDS OF 25-35 KT. VIS
LOCALLY REDUCED TO 3-5SM IN HEAVIER SHRA/TSRA.
&&
.MARINE...
130 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH WEDNESDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH FROM NOON PDT TODAY THROUGH THIS EVENING FOR
APPLE AND LUCERNE VALLEYS-SAN BERNARDINO COUNTY MOUNTAINS.
PZ...NONE.
&&
$$
PUBLIC...JAD
AVIATION/MARINE...JT
AREA FORECAST DISCUSSION...CORRECTED
NWS GOODLAND KS
138 PM MDT SAT OCT 17 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 137 PM MDT SAT OCT 17 2015
EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS INDICATED LONGWAVE
TROUGH ACROSS THE EASTERN US WITH RIDGING ACROSS THE PLAINS AND
INTO THE NORTHERN ROCKIES. A CLOSED UPPER LOW IS OFF THE NORTHERN
CALIFORNIA COAST. SURFACE LOW PRESSURE HAS DEVELOPED OVER NORTH
CENTRAL COLORADO WITH TIGHT SOUTHERLY GRADIENT ACROSS THE PLAINS
RESPONSIBLE FOR BREEZY-WINDY CONDITIONS ACROSS OUR CWA.
TONIGHT-SUNDAY...CLOSED LOW OFF PACIFIC NW WILL SHIFT TOWARDS THE
GREAT BASIN AND WITH A WEAKER SHORTWAVE TROUGH ROTATING AROUND
NORTHERN EDGE OF UPPER RIDGE INTO THE NORTHERN PLAINS. WEAK
FORCING WILL BE RESPONSIBLE FOR PERIODS OF HIGH CLOUD COVER
OTHERWISE A DEEP DRY LAYER IN PLACE WILL PREVENT PRECIP
DEVELOPMENT IN OUR CWA THROUGH SUNDAY AFTERNOON. LEE TROUGH WILL
SHIFT EAST OVER OUR CWA WITH INCREASING WAA AND UNSEASONABLY WARM
TEMPERATURES RETURNING. BASED ON MIXING HEIGHTS/TEMPS ALOFT WE
SHOULD SEE HIGHS AROUND 80F WHICH IS ABOUT 15F ABOVE NORMAL
SUNDAY. LOWS TONIGHT WILL BE TRICKY AS A RESULT OF A MODERATELY
STRONG LLJ INCREASING BL MIXING...HOWEVER LOCATIONS IN THE NORTH
AND ALONG VALLEYS SHOULD STILL BE ABLE TO DECOUPLE AND COOL TO
AROUND 40F.
WE MAY ALSO SEE A PERIOD OF LIGHT FOG DEVELOP ALONG VALLEYS/LOW
AREAS IN OUR NW ALONG SURFACE TROUGH AS LOW LEVEL MOISTURE
INCREASES. CONFIDENCE WAS TOO LOW AT THIS TIME TO INCLUDE MENTION
DUE TO EXPECTED MIXING...BUT WE WILL NEED TO MONITOR.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 116 PM MDT SAT OCT 17 2015
THE CENTRAL HIGH PLAINS WILL BE UNDER SOUTHWESTERLY TO SOUTHERLY
FLOW ALOFT THE ENTIRE LONG PERIOD AHEAD OF A SLOW MOVING TROUGH
SET TO MOVE OUT OF THE DESERT SOUTHWEST LATE IN THE WEEK. THE
LOWER LEVELS WILL GRADUALLY MOISTEN WITH THE FIRST CHANCE OF
PRECIPITATION OCCURRING TUESDAY NIGHT MAINLY SOUTH OF THE
INTERSTATE THEN SPREADING OVER THE REST OF THE AREA ON WEDNESDAY.
RAIN CHANCES WILL CONTINUE THROUGH THE END OF THE PERIOD WITH A
SERIES OF DISTURBANCES EJECTING OUT OF THE SOUTHWEST. MODELS
SUGGEST AREAS OF HEAVY RAIN POSSIBLE THURSDAY THROUGH THURSDAY
NIGHT AS THE MAIN LIFT MOVES OVER THE AREA. THE CLOUDS AND
PRECIPITATION WILL ALSO RESULT IN COOLER TEMPERATURES FOR THE END
OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1139 AM MDT SAT OCT 17 2015
VFR CONDITIONS SHOULD CONTINUE THROUGH THE TAF PERIOD AT BOTH
KGLD AND KMCK. SOME GUIDANCE IS HINTING AT FOG DEVELOPMENT AS
HIGHER LOW LEVEL MOISTURE ADVECTS NORTH ALONG SURFACE TROUGH AXIS
ORIENTATED ALONG KS/CO BORDER OVERNIGHT. THERE IS VERY LITTLE
CONSISTENCY WITH THIS AND BL WINDS SHOULD BE HIGH ENOUGH TO LIMIT
CHANCES FOR LOWER VIS/CIG AT EITHER TERMINAL. GUSTY SOUTH WINDS
(AROUND 20KT) SHOULD BEGIN TO SHIFT EAST AND DECREASE TO AROUND
12KT OR LESS BY 00Z. LOW LEVEL JET INCREASES OVERNIGHT AND WILL
RESULT IN STRONG LOW LEVEL WIND SHEER DEVELOPING AT BOTH
TERMINALS. AS THE SURFACE TROUGH SHIFTS EAST WIND SHEER SHOULD
DECREASE BY 10-12Z (WEST TO EAST).
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS JACKSON KY
200 PM EDT SAT OCT 17 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 200 PM EDT SAT OCT 17 2015
17Z SFC ANALYSIS SHOWS HIGH PRESSURE SETTLING INTO THE MID
MISSISSIPPI VALLEY WITH ITS INFLUENCE STRETCHING WELL EAST INTO
THE OHIO VALLEY. THIS HAS LED TO A DRY AIR MASS OVER EASTERN
KENTUCKY ALONG WITH AMPLE MORNING SUNSHINE. THESE FACTORS
CONTRIBUTED TO TEMPERATURES REBOUNDING INTO THE MIDDLE AND UPPER
50S BY EARLY THIS AFTERNOON. DEVELOPING CU TO THE NORTH WILL
LIMIT ADDITIONAL HEATING THERE...BUT THE SOUTH COULD RISE ANOTHER
COUPLE OF DEGREES FOR HIGHS. DEWPOINTS...MEANWHILE...ARE IN THE
UPPER 20S AND LOWER 30S YIELDING RH VALUES DOWN NEAR 30 PERCENT
IN THE SOUTH AND CLOSER TO 40 PERCENT NORTH. WINDS HAVE BEEN
GENERALLY OUT OF THE NORTH AT 5 TO 10 MPH.
THE MODELS REMAIN IN EXCELLENT AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST AS THEY ALL GRADUALLY MOVE A BROAD
AND RELATIVELY DEEP TROUGH THE NORTHEASTERN PARTS OF NORTH
AMERICA. IN THE WAKE OF THIS TROUGH DEPARTING THE OHIO VALLEY...
HEIGHTS WILL RISE OVER KENTUCKY SUNDAY INTO MONDAY MORNING. GIVEN
THIS AGREEMENT HAVE FOLLOWED THE WEATHER DETAILS...FEW THAT THERE
ARE...FROM THE HRRR AND NAM12. DID AGAIN LEAN HEAVILY ON THE GFS
BASED COOP MOS TO HELP HIT OUR VALLEY COLD SPOTS TONIGHT AND
SUNDAY NIGHT.
SENSIBLE WEATHER WILL FEATURE A COLD NIGHT UNDER MOSTLY CLEAR
SKIES...ONCE THE NORTHERN CU FADES AROUND SUNSET. GOOD RADIATIONAL
COOLING UNDER THE INVERSION WILL RESULT IN VALLEY TEMPS FALLING
INTO THE MIDDLE 20S WHILE RIDGES SETTLE INTO THE LOWER 30S. THESE
LOW TEMPS WILL WARRANT A FREEZE WARNING WITH THE POTENTIAL TO END
THE GROWING SEASON THROUGHOUT THE CWA...IN ADDITION TO ANTICIPATED
WIDESPREAD FROST. PATCHY DENSE FOG IN THE RIVER VALLEYS IS ALSO
LIKELY TO FORM GIVEN WHAT WE SAW THIS MORNING. AFTER COORDINATION
WITH THE UK AG WX CENTER YESTERDAY WILL CONTINUE FROST/FREEZE
HEADLINES INTO MONDAY MORNING REGARDLESS OF HOW COLD IT GETS
TONIGHT. FOLLOWING ANOTHER COOL DAY ON SUNDAY...CONDITIONS SIMILAR
TO TONIGHT WILL SET THE STAGE FOR ANOTHER ROUND OF FREEZING
TEMPERATURES IN THE VALLEYS...ESPECIALLY THE EASTERN ONES. SO...
THIS NECESSITATES ANOTHER FREEZE WARNING FOR LATE SUNDAY NIGHT
INTO MONDAY MORNING. AGAIN FROST WILL BE PREVALENT THROUGHOUT THE
AREA ALONG WITH PATCHY FOG IN THE RIVER VALLEYS.
AGAIN USED THE SHORTBLEND GUIDANCE AS A STARTING POINT FOR THE T
AND TD GRIDS INTO SUNDAY MORNING WITH THE SUPERBLEND USED
THEREAFTER. DID MAKE SOME SIGNIFICANT CHANGES TO THE T GRIDS
TONIGHT AND SUNDAY NIGHT TO ACCOUNT FOR THE ANTICIPATED RIDGE TO
VALLEY DIFFERENCES. AS FOR POPS...AGAIN WENT ZERO THROUGH THE
SHORT TERM PERIOD...IN LINE WITH ALL GUIDANCE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 200 PM EDT SAT OCT 17 2015
HIGH PRESSURE WILL DOMINATE THROUGH THE EXTENDED PORTION OF THE
FORECAST...PROVIDING DRY WEATHER AND WARMING TEMPERATURES THROUGH
THE FIRST HALF OF THE UPCOMING WEEK. GIVEN THE DEGREE OF DRY
WEATHER...HAVE OPTED TO TREND TEMPERATURES SLIGHTLY ABOVE GUIDANCE
FOR HIGHS EACH DAY...WHILE STAYING UNDER GUIDANCE FOR LOWS AT
NIGHT...ESPECIALLY IN THE VALLEYS. THIS MEANS WE SHOULD SEE HIGHS
AT OR ABOVE 70 FROM TUESDAY ONWARD...MAKING FOR A VERY PLEASANT
STRETCH OF WEATHER. A WASHED OUT FRONTAL BOUNDARY WILL DROP SOUTH
ACROSS THE AREA ON THURSDAY...BUT THE FEATURE CONTINUES TO TREND
WEAKER...AND WILL LIKELY HAVE MINIMAL IMPACT ON THE WEATHER ACROSS
EASTERN KENTUCKY. HIGH PRESSURE WILL THEN QUICKLY REBUILD AS WE HEAD
INTO NEXT WEEKEND...WITH THE MILD WEATHER CONTINUING INTO NEXT
WEEKEND.
MAIN WEATHER IMPACT WE WILL SEE THIS WEEK...IS THE CONTINUATION OF
THE DRY CONDITIONS WITH AFTERNOON RELATIVE HUMIDITIES FALLING TO
BETWEEN 20 AND 30 PERCENT. ITS LIKELY A FEW RH READINGS INTO THE
TEENS MAY BE POSSIBLE. WILL CONTINUE TO HIGHLIGHT THE LOW AFTERNOON
RELATIVE HUMIDITIES IN THE FIRE WEATHER FORECAST. FORTUNATELY...THE
GRADIENT SHOULD REMAIN WEAK ENOUGH TO LIMIT OVERALL WIND POTENTIAL
THROUGH THE WEEK...KEEPING WINDS UNDER 10 MPH. CONTINUED TO RUN
DEWPOINTS UNDER GUIDANCE EACH AFTERNOON AS MODELS TYPICALLY DON`T
HANDLE DEWPOINTS WELL IN THE AFTERNOON WITH GOOD MIXING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 110 PM EDT SAT OCT 17 2015
HIGH PRESSURE WILL REMAIN FIRMLY IN CONTROL OF THE WEATHER
THROUGH THE PERIOD. THIS WILL BRING VFR CONDITIONS TO EASTERN
KENTUCKY. AT LEAST THE NORTHERN SITES MAY SEE A FEW CLOUDS AT 5KT
FEET THIS AFTERNOON. WINDS WILL GENERALLY BE OUT OF THE NORTH AT
5 TO 10 KTS THROUGH THE REST OF THE AFTERNOON...LIGHT OVERNIGHT
AND THEN AROUND 5 KTS OUT OF THE NORTHWEST FOR THE FIRST PART OF
SUNDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM 3 AM TO 9 AM EDT SUNDAY FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
FREEZE WARNING FROM 3 AM TO 9 AM EDT MONDAY FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1210 PM CDT SAT OCT 17 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 245 AM CDT SAT OCT 17 2015
SATELLITE LOOP SHOWS AREA OF MID CLOUDS HAS BEEN EXPANDING
SOUTHWARD ACROSS EASTERN NEBRASKA AND WESTERN IOWA LIKELY
LIMITING FROST POTENTIAL FOR THE AREA THIS MORNING. RAP 700 RH
ALSO SHOWS THIS TREND THROUGH 15Z. PLAN TO KEEP ADVISORY GOING
FOR NOW BUT MENTION MORE LIMITED EXTENT IN WORDING OF STATEMENT.
LITTLE CHANGE OTHERWISE TO REMAINDER OF THE FORECAST THROUGH
MONDAY WITH WARMING TREND AND DRY CONDITIONS STILL ON TRACK.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 245 AM CDT SAT OCT 17 2015
EXTENDED PERIOD CONTINUES TO SHOW SIGNS OF A MORE ACTIVE PATTERN
AS CLOSED LOW OVER THE FAR SOUTHWEST GRADUALLY OPENS AND PHASES
WITH THE NORTHERN STREAM BY LATE IN THE PERIOD. GOOD MOISTURE
FETCH DEVELOPS ACROSS THE CENTRAL PART OF THE NATION IN ADVANCE
OF THE TROUGH WITH AN INCREASING CHANCE OF SHOWERS FOR THE AREA
DURING THE PERIOD AS THIS SYSTEM DEVELOPS. THE SOUTHERLY FLOW
WILL ALSO HELP TO MAINTAIN ABOVE NORMAL TEMPERATURES DURING THIS
TIME.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1207 PM CDT SAT OCT 17 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD.
SOUTHEASTERLY WINDS WILL INCREASE THIS AFTERNOON BEFORE CALMING
DOWN THIS EVENING. GUSTIER WINDS WILL BE POSSIBLE AT ALL SITES
LATE SUNDAY MORNING AS WELL.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...KG
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
700 PM EDT SAT OCT 17 2015
.SYNOPSIS...
A STRONG BUT DRY COLD FRONT WILL MOVE THROUGH TONIGHT. HIGH
PRESSURE WILL BUILD OVER THE AREA THIS WEEKEND THROUGH MUCH OF
NEXT WEEK. THE NEXT FRONTAL SYSTEM WILL APPROACH THE REGION LATE
NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
AS OF 7 PM SAT...KAKQ RADAR INDICATES NEXT COLD FRONT DRAPED W-E
ACROSS SE VA. TOA TOOL INDICATES THE FRONT MOVING INTO NORTHERN
CWA AFTER 02Z THIS EVENING. MODELS IN EXCELLENT AGREEMENT ON NEXT
SURGE OF CAA COMMENCING THIS EVENING. UPSTREAM THICKNESSES ARE
FALLING ACROSS THE INTERIOR CAROLINAS EARLY EVENING...WITH LOW
LEVEL WINDS VEERING NORTH. USED A BLEND OF HIGH RES MODELS TO
FCST WINDS OVERNIGHT...AND SHOULD SEE ENOUGH DRY/COLD ADVECTION
AND LOW LEVEL MIXING TO PRECLUDE ANY FOG DEVELOPMENT. A WIDE RANGE
OF LOWS EXPECTED...WITH UPR 30S INLAND TO LOW 50S OBX...WHERE WIND
ADVECTING OVER THE RELATIVELY WARM WATERS WILL KEEP TEMPS UP HERE.
&&
.SHORT TERM /SUNDAY/...
AS OF 330 PM SAT...DEEP/COLD TROUGH AXIS PROGGED TO MOVE ACROSS
EASTERN CONUS ON SUNDAY WITH SFC HIGH PRES BUILDING INTO THE OHIO
VALLEY. LOW LEVEL THICKNESS VALS ON PAR WITH MOS GUID FORECASTING
CHILLY MAX TEMPS IN THE UPR 50S TO NEAR 60...COOLEST NORTH.
CONTINUED CAA AND NORTH WINDS WILL MAKE IT FEEL QUITE BRISK
DESPITE FULL SUNSHINE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 330 PM SAT...MINOR ADJUSTMENTS TO TEMPS DURING PERIOD.
MODELS REMAIN IN GOOD AGREEMENT THAT RIDGING SFC AND ALOFT WILL
CONTINUE THROUGH MID WEEK...FOLLOWED BY ANOTHER DRY COLD FRONTAL
PASSAGE FRIDAY.
MAIN SIGNIFICANT WX THREAT DURING PERIOD WILL BE PSBL FROST SUN
NIGHT AND AGAIN MON NIGHT. MODEL GDNC CONTINUES TO INDICATE
COLDEST TEMPS SUN NIGHT WTIH LOWS 33-36 DEGS FOR NORMALLY COLDER
AREAS ALONG AND W OF HWY 17. COULD EVEN SEE SOME 32 DEG READINGS
IN ISOLATED AREAS BUT NOT EXPECTED TO BE WDSPRD ENOUGH TO WARRANT
FREEZE WATCH...BUT FROST ADVSY LIKELY TO BE ISSUED WITH NEXT FULL
FCST PACKAGE AROUND 4 AM SUNDAY. GOOD RADIATIONAL COOLING
CONDITIONS LIKELY AGAIN MON NIGHT WITH SFC HIGH CENTER OVER AREA
RESULTING IN LIGHT WINDS ALL THE WAY TO COAST. MOS GDNC INDICATING
LOWS MID TO UPR 30S FOR MOST INLAND AREAS...AND COULD SEE SCT
FROST THREAT EVEN CLOSER TO COAST THAN ON SUN NIGHT.
TEMPS WILL GRADUALLY MODERATE TUE-THU WITH RIDGING ALOFT WHILE SFC
HIGH EXTENDS OVER AREA FROM OFFSHORE. LOWS WILL BE IN 40S AND 50S
WITH HIGHS IN THE 70S.
FRIDAY TO SATURDAY...12Z GFS AND ECMWF HAVE COME INTO BETTER
AGREEMENT WITH ANOTHER DRY COLD FRONT MOVING THROUGH EARLY FRIDAY
FOLLOWED BY HIGH PRES RIDING IN FROM N FRI NIGHT AND SAT. TEMPS
WILL DROP BACK INTO 40S FRI NIGHT WITH HIGHS IN 60S FOR SAT.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH 18Z SUNDAY/...
AS OF 7 PM SAT...PRED VFR EXPECTED THROUGH THE PERIOD WITH SUNNY
SKIES...LIGHT N/NW WINDS 5-10KT. WILL ADD NON CONVECTIVE LLWS TO
ALL TERMINALS TONIGHT AS STRONG NORTHERLY WINDS DEVELOP JUST OFF
THE SURFACE. WINDS WILL MIX TO THE SURFACE BY MID MORNING SUNDAY
AND BECOME A BIT GUSTY 14-18 KT.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 330 PM SAT...HIGH CONFIDENCE OF VFR CONDITIONS WILL
CONTINUE THROUGH THIS PERIOD AS HIGH PRESSURE DOMINATES THE
REGION.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY...
AS OF 7 PM SAT...LATEST OBS INDICATE NORTH WINDS CONTINUING IN
THE 5-10 KT RANGE EARLY EVENING WITH SOME HIGHER GUSTS. STRONG
COLD AIR ADVECTION WILL COMMENCE THIS EVENING WITH SCA HEADLINES
ON TRACK TO BEGIN JUST PRIOR TO MIDNIGHT. TOA TOOL INDICATES COLD
FRONT DRAPED W-E ACROSS SE VA AND PROGGED TO MOVE INTO NORTHERN
WATERS AND ALBEMARLE SOUND JUST AFTER 02Z. USED A BLEND OF HIGH
RES MODELS INCLUDING THE HRRR TO FCST WINDS. WINDS INC TO SCA
RANGE THIS EVENING AND WILL PEAK LATE TONIGHT IN THE 20-25 KT
RANGE WITH SOME GUSTS TO 30 KT FOR ALL WATERS AND
SOUNDS...EXCLUDING THE BAY...PAMLICO...AND NEUSE RIVERS...THOUGH
OCNL GUSTS TO 25 KT ARE CERTAINLY POSSIBLE PER HRRR FCST. SEAS
WILL BUILD DRAMATICALLY TONIGHT AND PEAK IN THE 5 TO 8 FT
RANGE...HIGHEST OUTER CENTRAL AND NRN WATERS. WINDS WILL COME DOWN
A BIT TO 10-20 KT ON SUNDAY BUT SEAS WILL REMAIN ELEVATED ABOVE 6
FT.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 330 PM SAT...MODELS REMAIN IN GOOD AGREEMENT WITH FINAL CAA
SURGE PRODUCING N-NE WINDS 20-25 KT OVER MOST OF WATERS SUN NIGHT
INTO MONDAY...AND EXTENDED SCA HEADLINES ACCORDINGLY. WINDS
DIMINISH QUICKLY LATE MON AND MON NIGHT. SFC RIDGE AXIS EXTENDING
W TO E ACROSS WATERS WILL LEAD TO LIGHT AND SOMEWHAT VRBL
CONDITIONS TUE-THU.
LATEST WAVE GDNC SUPPORTS PREVIOUS FCST WTIH SEAS BUILDING TO 5-7
FT SUN NIGHT...THEN SUBSIDING ON MONDAY WITH DIMINISHING WINDS.
HEIGHTS MAINLY 2-3 FT TUE-THU.
&&
.CLIMATE...
RECORD MIN TEMPS FOR 10/19 (MONDAY)
LOCATION TEMP/YEAR
NEW BERN 33/1948 (KEWN ASOS)
CAPE HATTERAS 39/1978 (KHSE ASOS)
GREENVILLE 33/1970 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 37/1967 (COOP - NOT KMRH ASOS)
KINSTON 30/1973 (COOP - NOT KISO AWOS)
JACKSONVILLE 36/1992 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
MONDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
SUNDAY FOR AMZ130-131.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
MONDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 PM EDT
MONDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...JBM
AVIATION...JBM/TL
MARINE...JBM/TL
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
634 PM EDT SAT OCT 17 2015
.SYNOPSIS...CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION FROM
THE NORTHWEST TONIGHT AND SUNDAY...THEN SETTLE OVER THE CAROLINAS
THROUGH MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM SATURDAY...
A MID-LEVEL TROUGH CONTINUED TO MAKE PROGRESS TOWARD CENTRAL NORTH
CAROLINA ON WATER VAPOR IMAGERY AS A COLD FRONT MOVED SOUTH ACROSS
VIRGINIA. THIS FRONT WILL USHER INTO CENTRAL NORTH CAROLINA A SURGE
OF COOLER THICKNESSES TONIGHT. THETA-E VALUES REMAIN DRY...AND
PRECIPITABLE WATER VALUES FALL TO NEAR A QUARTER-INCH AS K INDICES
ARE VERY NEGATIVE. IT IS ANTICIPATED THAT...WITH THE PASSAGE OF THE
MID-LEVEL TROUGH AND THE COLD FRONT...ALONG WITH THE SURGE IN COOLER
THICKNESSES AND A MODEST 700MB SHORTWAVE...LOW-LEVEL WINDS SHOULD
INCREASE MODESTLY OR AT LEAST REMAIN STEADY AND NOTICEABLE THROUGH
THE EVENING AND THE EARLY PART OF THE OVERNIGHT. HOWEVER...LATE
TONIGHT...THE CONSENSUS OF THE GUIDANCE SUGGESTS THAT WINDS SHOULD
DIMINISH SUFFICIENTLY ALONG AND WEST OF A LINE FROM ABOUT ALBEMARLE
TO HENDERSON THAT LOW TEMPERATURES...IN THE DRY AIR...COULD GET TO
34 TO 36 IN MANY SPOTS. THE RAP SURFACE GRADIENT ACTUALLY BECOMES
QUITE SLACK BY AROUND 07Z OR SO IN THE NORTHWEST PIEDMONT. GIVEN
THESE EXPECTED CONDITIONS...WILL ISSUE A FROST ADVISORY FOR THAT
AREA. CURRENTLY THINK THAT THE IMMEDIATE TRIAD CITIES WILL HAVE A
HARDER TIME COOLING ENOUGH TO GET MUCH FROST...AS WELL AS THE
INTERIOR OF CITIES SUCH AS CHAPEL HILL AND DURHAM...BUT OUTLYING
AREAS OF THEIR COUNTIES COULD CERTAINLY BE AFFECTED. FARTHER EAST
OVER THE NORTHERN COASTAL PLAIN...THERE SHOULD BE SOME AREAS OF MID
30S BUT WINDS SHOULD STAY UP A LITTLE LONGER. THANKS TO ADJACENT
OFFICES FOR THE COORDINATION WITH REGARD TO THE ADVISORY.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 230 PM SATURDAY...
PRECIPITABLE WATER VALUES REMAIN LOW SUNDAY AND SUNDAY NIGHT...NEAR
A QUARTER-INCH...WITH NEGATIVE K INDICES AND SUBSIDENCE...AND UPPER-
LEVEL CONFLUENCE PARTICULARLY FROM SUNDAY AFTERNOON THROUGH SUNDAY
NIGHT. 850MB RELATIVE HUMIDITY VALUES ARE EXPECTED TO DIMINISH EVEN
A LITTLE FURTHER LATE SUNDAY NIGHT. WITH CLEAR CONDITIONS AND A
SLACK GRADIENT AS THE SURFACE RIDGE CONTINUES TO BUILD IN FROM THE
NORTHWEST...ALONG WITH DIMINISHING 925MB WINDS...QUITE COOL
TEMPERATURES ARE LIKELY LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING.
HIGH TEMPERATURES SUNDAY WILL STRUGGLE TO GET INTO THE UPPER 50S AND
SHOULD END UP...OVERALL ACROSS CENTRAL NORTH CAROLINA...JUST AROUND
60. OVERNIGHT SUNDAY...THE COMBINATION OF CLEAR SKIES...LIGHT
WINDS...AND DRY AIR SHOULD ALLOW TEMPERATURES TO FALL READILY. WHILE
NOT EXPECTING A HARD FREEZE...ANTICIPATE QUITE A FEW 31S AND 32S
PARTICULARLY OUTSIDE OF THE LARGER CITIES WEST OF A LINE FROM ABOUT
KMEB TO SCOTLAND NECK. FOR THIS FORECAST...WILL ISSUE A FREEZE WATCH
FOR ALL OF CENTRAL NORTH CAROLINA EXCEPT THE FAR SOUTHEAST AND
EASTERN ZONES...WHERE OVERNIGHT LOWS SHOULD BE A LITTLE ABOVE
FREEZING OVERALL AND LOW-LEVEL WINDS FOR MUCH OF THE NIGHT SHOULD BE
JUST A TRIFLE MORE NOTICEABLE. THIS FORECAST WILL NOT FEATURE ANY
RECORD LOWS AT KGSO...KRDU...OR KFAY...BUT IT WILL BE CLOSE
ESPECIALLY AT KRDU...WHERE THE MAV MOS FORECASTS A LOW TEMPERATURE
EARLY MONDAY MORNING JUST A DEGREE ABOVE THE RECORD OF FREEZING...
SET BACK IN 1948.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 100 PM SATURDAY...
MON THROUGH TUE NIGHT EARLY MON MORNING IS LIKELY TO PRESENT US WITH
THE CHILLIEST TEMPS OF THIS STRETCH. THE COLD SURFACE RIDGE WILL
REMAIN EXTENDED ACROSS CENTRAL NC DURING THE PERIOD... WHILE
UNDERGOING STEADY SLOW AIR MASS MODIFICATION. CLOUDS WILL BE FEW IN
NUMBER TO NONE THROUGH TUE NIGHT AS HEIGHTS BUILD ALOFT OVER THE
GULF AND SOUTHEAST STATES (A FUNCTION OF A DEEPENING LOW OVER NW MEX
AND ADJACENT CA/AZ) WITH DEEP DRY AIR AND SUBSIDENCE OVER NC... AND
EVEN THE PASSAGE OF A WEAK VORTICITY MAX LATE MON NIGHT INTO TUE
MORNING WILL HAVE LITTLE NO MOISTURE TO WORK WITH... YIELDING A FEW
HIGH THIN CLOUDS AT MOST. A SHALLOW BUT DRY ADIABATIC MIXED LAYER
MON ALONG WITH STATISTICAL GUIDANCE AND ANOMALOUSLY LOW THICKNESSES
(STARTING THE DAY AROUND 45-50 M BELOW NORMAL) SUGGESTS HIGHS OF 56-
62. WIND SPEEDS SHOULD ONCE AGAIN DROP TO 0-2 KTS MON NIGHT WITH
DECOUPLING... AND WITH CLEAR SKIES... EXPECT LOWS OF 32-38. OUTLYING
AREAS HAVE ONE MORE SHOT AT SOME FROST. MORE OF THE SAME TUE WITH
DEEPLY DRY AND STABLE AIR... ALTHOUGH THE SURFACE RIDGE WILL BE
LOSING STEAM OVERHEAD... GIVING WAY TO ENOUGH LOW LEVEL WARMING TO
PUSH THICKNESSES UP TO JUST 20-25 M BELOW NORMAL... AS THE WARMER
AIR ALOFT FINALLY STARTS TO WORK DOWN TO THE SURFACE. HIGHS 64-68.
ANOTHER GOOD NIGHT OF RADIATIONAL COOLING TUE NIGHT... BUT THE
DEWPOINTS WILL BE HIGHER WITH THE MODIFIED AIR MASS... ESPECIALLY IN
THE SE CWA. LOWS 38-45.
WED-SAT: WARM FOR A COUPLE OF DAYS... THEN BACK TO A LITTLE BELOW
NORMAL FOR A COUPLE OF DAYS... BUT STILL NO SIGNIFICANT PRECIP IN
SIGHT. THE MID LEVEL RIDGE COVERING THE GULF COAST/GULF STATES AND
SOUTHEAST STATES WED STARTS TO RETROGRADE IN RESPONSE TO POLAR-
STREAM SHORTWAVE ENERGY DIVING SE THROUGH NEW ENGLAND/NORTHEAST
STATES LATE THU/THU NIGHT... AND PASSAGE AT THE SURFACE OF AN
ASSOCIATED BACKDOOR COLD FRONT THROUGH NC. THE ENHANCED NW FLOW
ALOFT SHOULD BRING SOME POCKETS OF WEAK VORTICITY DOWN THROUGH NC
THU NIGHT... BUT ONCE AGAIN THERE IS NO OPPORTUNITY FOR SUBSTANTIAL
MOISTURE ADVECTION... INDICATING LITTLE IN THE WAY OF SKY COVER. THE
LONE EXCEPTION MAY BE EARLY FRI ACROSS THE SOUTH AND WEST WHERE LOW
LEVEL ATLANTIC-SOURCE MOIST UPGLIDE COULD HELP GENERATE SOME
STRATOCU. BUT OTHERWISE... ANY MOISTURE IS TOO SHALLOW OR FLEETING
FOR ANY MEASURABLE PRECIP... AND EXPECT JUST PARTLY CLOUDY SKIES AT
WORST LATE THU NIGHT INTO EARLY FRI. HIGHS IN THE LOW-MID 70S
WED/THU... SLIPPING BACK TO THE MID 60S TO AROUND 70 FRI/SAT.
WARMEST LOWS THU NIGHT IN THE UPPER 40S TO LOWER 50S... BUT
OTHERWISE EXPECT LOWS IN THE MID 40S TO NEAR 50. -GIH
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 635 PM SATURDAY...
24-HR TAF PERIOD: HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE TAF
PERIOD. CLEAR SKIES AND A LIGHT NORTHERLY WIND WILL PREVAIL
OVERNIGHT AS CANADIAN HIGH PRESSURE BUILDS TOWARD THE REGION FROM
THE NORTHWEST. NORTHERLY WINDS WILL INCREASE A FEW HRS AFTER SUNRISE
SUN...BECOMING 7-12 KT WITH GUSTS UP TO 15-20 KT THROUGH THE
AFTERNOON. WINDS WILL RAPIDLY DECREASE TO ~5 KT AN HOUR OR TWO PRIOR
TO SUNSET SUN EVENING IN ASSOC/W THE NOCTURNAL INVERSION.
LOOKING AHEAD: EXCELLENT AVIATION WEATHER /VFR CONDITIONS/ ARE
EXPECTED TO PERSIST THROUGH MID-LATE WEEK AS CANADIAN HIGH PRESSURE
SETTLES DIRECTLY OVER THE REGION. -VINCENT
&&
.CLIMATE...
RECORD LOW TEMPERATURES FOR OCTOBER 19...
KGSO...28 DEGREES IN 1948.
KRDU...32 DEGREES IN 1948.
KFAY...32 DEGREES IN 1931.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE SUNDAY NIGHT THROUGH EARLY MONDAY MORNING FOR
NCZ007>011-021>027-038>042-073>077-083-084.
FROST ADVISORY FROM 4 AM TO 9 AM EDT SUNDAY FOR NCZ007>009-
021>025-038-039-073.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...HARTFIELD
AVIATION...VINCENT
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
430 PM EDT SAT OCT 17 2015
.SYNOPSIS...
A STRONG BUT DRY COLD FRONT WILL MOVE THROUGH TONIGHT. HIGH
PRESSURE WILL BUILD OVER THE AREA THIS WEEKEND THROUGH MUCH OF
NEXT WEEK. THE NEXT FRONTAL SYSTEM WILL APPROACH THE REGION LATE
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 330 PM SAT...LAST MILD DAY TODAY AS A STRONG BUT DRY COLD
FRONT WILL PUSH THROUGH TONIGHT.
MODELS IN EXCELLENT AGREEMENT ON NEXT SURGE OF CAA COMMENCING THIS
EVENING. UPSTREAM THICKNESSES ARE FALLING ACROSS THE INTERIOR
CAROLINAS THIS AFTERNOON...WITH LOW LEVEL WINDS VEERING NORTH TO
NORTHWEST. USED A BLEND OF HIGH RES MODELS TO FCST WINDS
OVERNIGHT...AND SHOULD SEE ENOUGH DRY/COLD ADVECTION AND LOW
LEVEL MIXING TO PRECLUDE ANY FOG DEVELOPMENT. A WIDE RANGE OF LOWS
EXPECTED...WITH UPR 30S INLAND TO LOW 50S OBX...WHERE WIND
ADVECTING OVER THE RELATIVELY WARM WATERS WILL KEEP TEMPS UP HERE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AS OF 330 PM SAT...DEEP/COLD TROUGH AXIS PROGGED TO MOVE ACROSS
EASTERN CONUS ON SUNDAY WITH SFC HIGH PRES BUILDING INTO THE OHIO
VALLEY. LOW LEVEL THICKNESS VALS ON PAR WITH MOS GUID FORECASTING
CHILLY MAX TEMPS IN THE UPR 50S TO NEAR 60...COOLEST NORTH.
CONTINUED CAA AND NORTH WINDS WILL MAKE IT FEEL QUITE BRISK
DESPITE FULL SUNSHINE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 330 PM SAT...MINOR ADJUSTMENTS TO TEMPS DURING PERIOD.
MODELS REMAIN IN GOOD AGREEMENT THAT RIDGING SFC AND ALOFT WILL
CONTINUE THROUGH MID WEEK...FOLLOWED BY ANOTHER DRY COLD FRONTAL
PASSAGE FRIDAY.
MAIN SIGNIFICANT WX THREAT DURING PERIOD WILL BE PSBL FROST SUN
NIGHT AND AGAIN MON NIGHT. MODEL GDNC CONTINUES TO INDICATE
COLDEST TEMPS SUN NIGHT WTIH LOWS 33-36 DEGS FOR NORMALLY COLDER
AREAS ALONG AND W OF HWY 17. COULD EVEN SEE SOME 32 DEG READINGS
IN ISOLATED AREAS BUT NOT EXPECTED TO BE WDSPRD ENOUGH TO WARRANT
FREEZE WATCH...BUT FROST ADVSY LIKELY TO BE ISSUED WITH NEXT FULL
FCST PACKAGE AROUND 4 AM SUNDAY. GOOD RADIATIONAL COOLING
CONDITIONS LIKELY AGAIN MON NIGHT WITH SFC HIGH CENTER OVER AREA
RESULTING IN LIGHT WINDS ALL THE WAY TO COAST. MOS GDNC INDICATING
LOWS MID TO UPR 30S FOR MOST INLAND AREAS...AND COULD SEE SCT
FROST THREAT EVEN CLOSER TO COAST THAN ON SUN NIGHT.
TEMPS WILL GRADUALLY MODERATE TUE-THU WITH RIDGING ALOFT WHILE SFC
HIGH EXTENDS OVER AREA FROM OFFSHORE. LOWS WILL BE IN 40S AND 50S
WITH HIGHS IN THE 70S.
FRIDAY TO SATURDAY...12Z GFS AND ECMWF HAVE COME INTO BETTER
AGREEMENT WITH ANOTHER DRY COLD FRONT MOVING THROUGH EARLY FRIDAY
FOLLOWED BY HIGH PRES RIDING IN FROM N FRI NIGHT AND SAT. TEMPS
WILL DROP BACK INTO 40S FRI NIGHT WITH HIGHS IN 60S FOR SAT.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH 18Z SUNDAY/...
AS OF 1 PM SAT...PRED VFR EXPECTED THROUGH THE PERIOD WITH SUNNY
SKIES...LIGHT N/NW WINDS 5-10KT. WILL ADD NON CONVECTIVE LLWS TO
ALL TERMINALS TONIGHT AS STRONG NORTHERLY WINDS DEVELOP JUST OFF
THE SURFACE. WINDS WILL MIX TO THE SURFACE BY MID MORNING SUNDAY
AND BECOME A BIT GUSTY 14-18 KT.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 330 PM SAT...HIGH CONFIDENCE OF VFR CONDITIONS WILL
CONTINUE THROUGH THIS PERIOD AS HIGH PRESSURE DOMINATES THE
REGION.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY...
AS OF 330 PM SAT...LATEST OBS INDICATE NORTH WINDS CONTINUING IN
THE 5-10 KT RANGE THIS AFTERNOON WITH SOME HIGHER GUSTS. STRONG
COLD AIR ADVECTION WILL COMMENCE THIS EVENING WITH SCA HEADLINES
ON TRACK TO BEGIN JUST PRIOR TO MIDNIGHT. USED A BLEND OF HIGH RES
MODELS INCLUDING THE HRRR TO FCST WINDS. WINDS INC TO SCA RANGE
THIS EVENING AND WILL PEAK LATE TONIGHT IN THE 20-25 KT RANGE WITH
SOME GUSTS TO 30 KT FOR ALL WATERS AND SOUNDS...EXCLUDING THE
BAY...PAMLICO...AND NEUSE RIVERS...THOUGH OCNL GUSTS TO 25 KT ARE
CERTAINLY POSSIBLE PER HRRR FCST. SEAS WILL BUILD DRAMATICALLY
TONIGHT AND PEAK IN THE 5 TO 8 FT RANGE...HIGHEST OUTER CENTRAL
AND NRN WATERS. WINDS WILL COME DOWN A BIT TO 10-20 KT ON SUNDAY
BUT SEAS WILL REMAIN ELEVATED ABOVE 6 FT.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 330 PM SAT...MODELS REMAIN IN GOOD AGREEMENT WITH FINAL CAA
SURGE PRODUCING N-NE WINDS 20-25 KT OVER MOST OF WATERS SUN NIGHT
INTO MONDAY...AND EXTENDED SCA HEADLINES ACCORDINGLY. WINDS
DIMINISH QUICKLY LATE MON AND MON NIGHT. SFC RIDGE AXIS EXTENDING
W TO E ACROSS WATERS WILL LEAD TO LIGHT AND SOMEWHAT VRBL
CONDITIONS TUE-THU.
LATEST WAVE GDNC SUPPORTS PREVIOUS FCST WTIH SEAS BUILDING TO 5-7
FT SUN NIGHT...THEN SUBSIDING ON MONDAY WITH DIMINISHING WINDS.
HEIGHTS MAINLY 2-3 FT TUE-THU.
&&
.CLIMATE...
RECORD MIN TEMPS FOR 10/19 (MONDAY)
LOCATION TEMP/YEAR
NEW BERN 33/1948 (KEWN ASOS)
CAPE HATTERAS 39/1978 (KHSE ASOS)
GREENVILLE 33/1970 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 37/1967 (COOP - NOT KMRH ASOS)
KINSTON 30/1973 (COOP - NOT KISO AWOS)
JACKSONVILLE 36/1992 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
MONDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
SUNDAY FOR AMZ130-131.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
MONDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 PM EDT
MONDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...JBM
AVIATION...JBM/TL
MARINE...JBM/TL
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
330 PM EDT SAT OCT 17 2015
.SYNOPSIS...
A STRONG BUT DRY COLD FRONT WILL MOVE THROUGH TONIGHT. HIGH
PRESSURE WILL BUILD OVER THE AREA THIS WEEKEND THROUGH MUCH OF
NEXT WEEK. THE NEXT DRY FRONTAL SYSTEM WILL APPROACH THE REGION
LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM SAT...LAST MILD DAY TODAY AS A STRONG BUT DRY COLD
FRONT WILL PUSH THROUGH TONIGHT.
MODELS IN EXCELLENT AGREEMENT ON NEXT SURGE OF CAA COMMENCING THIS
EVENING. UPSTREAM THICKNESSES ARE FALLING ACROSS THE INTERIOR
CAROLINAS THIS AFTERNOON...WITH LOW LEVEL WINDS VEERING NORTH TO
NORTHWEST. USED A BLEND OF HIGH RES MODELS TO FCST WINDS
OVERNIGHT...AND SHOULD SEE ENOUGH DRY/COLD ADVECTION AND LOW
LEVEL MIXING TO PRECLUDE ANY FOG DEVELOPMENT. A WIDE RANGE OF LOWS
EXPECTED...WITH UPR 30S INLAND TO LOW 50S OBX...WHERE WIND
ADVECTING OVER THE RELATIVELY WARM WATERS WILL KEEP TEMPS UP HERE.
&&
.SHORT TERM /SUNDAY/...
AS OF 330 PM SAT...DEEP/COLD TROUGH AXIS PROGGED TO MOVE ACROSS
EASTERN CONUS ON SUNDAY WITH SFC HIGH PRES BUILDING INTO THE OHIO
VALLEY. LOW LEVEL THICKNESS VALS ON PAR WITH MOS GUID FORECASTING
CHILLY MAX TEMPS IN THE UPR 50S TO NEAR 60...COOLEST NORTH.
CONTINUED CAA AND NORTH WINDS WILL MAKE IT FEEL QUITE BRISK
DESPITE FULL SUNSHINE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 345 AM SAT...NO SIGNIFICANT CHANGES DURING THIS FORECAST
PERIOD AS MODELS REMAIN IN AGREEMENT AS THE MAIN STORY WILL BE
HIGH PRESSURE AND DRY CONDITIONS WILL PERSISTING THROUGH MUCH OF
NEXT WEEK.
SUNDAY AND MONDAY...EXPECT BELOW NORMAL TEMPERATURES AS UPPER
LEVEL TROF CROSSES THE AREA... MEANWHILE SFC HIGH PRESSURE BUILDS
IN FROM THE NW AND OVER THE AREA BY MONDAY. SUNDAY WILL START OUT
CHILLY AS CAA HAS MOVED INTO THE REGION...BUT MONDAY MORNING LOOKS
LIKE IT WILL BE EVEN COOLER THAN SUNDAY. EXPECT MONDAY LOWS IN THE
LOW/MID 30S...WITH POSSIBLE FROST. TEMPERATURES WILL WARM UP INTO
THE UPPER 50 TO LOW 60S FOR BOTH DAYS.
TUESDAY THROUGH THURSDAY...AS SFC HIGH PRESSURE SLIDES OFF THE
COAST ON TUESDAY...THE UPPER LEVEL RIDGE BUILDS INTO THE REGION.
THIS WILL ALLOW FOR TEMPERATURES TO INCREASE SLIGHTLY...BUT REMAIN
DRY. HIGH TEMPERATURES WILL RISE INTO THE 60S TUES AND THEN INTO
THE 70S WED/THURS AS SOUTHERLY FLOW RETURNS BACK. THURSDAY...THERE
IS A SLIGHT CHANCE OF SHOWERS MAINLY OVER THE COASTAL WATERS.
FRIDAY TO SATURDAY...MODELS START TO DISAGREE AS 00Z GFS BRINGS A
THE COLD FRONT FASTER THAN ECMWF. WENT WITH WPC
AGREEMENT...BRINGING THE DRY COLD FRONT FRIDAY AND SFC HIGH
PRESSURE BUILDING INTO THE AREA SATURDAY.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM SAT...PRED VFR EXPECTED THROUGH THE PERIOD WITH SUNNY
SKIES...LIGHT N/NW WINDS 5-10KT. WILL ADD NON CONVECTIVE LLWS TO
ALL TERMINALS TONIGHT AS STRONG NORTHERLY WINDS DEVELOP JUST OFF
THE SURFACE. WINDS WILL MIX TO THE SURFACE BY MID MORNING SUNDAY
AND BECOME A BIT GUSTY 14-18 KT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM SAT...HIGH CONFIDENCE OF VFR CONDITIONS WILL
CONTINUE THROUGH THIS PERIOD AS HIGH PRESSURE DOMINATES THE
REGION.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 330 PM SAT...LATEST OBS INDICATE NORTH WINDS CONTINUING IN
THE 5-10 KT RANGE THIS AFTERNOON WITH SOME HIGHER GUSTS. STRONG
COLD AIR ADVECTION WILL COMMENCE THIS EVENING WITH SCA HEADLINES
ON TRACK TO BEGIN JUST PRIOR TO MIDNIGHT. USED A BLEND OF HIGH RES
MODELS INCLUDING THE HRRR TO FCST WINDS. WINDS INC TO SCA RANGE
THIS EVENING AND WILL PEAK LATE TONIGHT IN THE 20-25 KT RANGE WITH
SOME GUSTS TO 30 KT FOR ALL WATERS AND SOUNDS...EXCLUDING THE
BAY...PAMLICO...AND NEUSE RIVERS...THOUGH OCNL GUSTS TO 25 KT ARE
CERTAINLY POSSIBLE PER HRRR FCST. SEAS WILL BUILD DRAMATICALLY
TONIGHT AND PEAK IN THE 5 TO 8 FT RANGE...HIGHEST OUTER CENTRAL
AND NRN WATERS. WINDS WILL COME DOWN A BIT TO 10-20 KT ON SUNDAY
BUT SEAS WILL REMAIN ELEVATED ABOVE 6 FT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 350 AM SAT...CAA WILL BE IN PLACE ACROSS THE COASTAL
WATERS... THEREFORE EXPECTING 15-20 KNOTS SUNDAY AND THEN 15-25
KNOTS INTO MONDAY MORNING WITH SEAS 4 TO 7 FT NORTH OF CAPE
LOOKOUT AND 3 TO 5 FEET SOUTH. BOTH NWPS AND WW3 HAVE AN AGREEMENT
WITH WAVES SUBSIDING QUICKER ON MONDAY NIGHT INTO TUESDAY AS HIGH
PRESSURE IS OVER THE AREA...RESULTING IN LIGHT AND VARIABLE
CONDITIONS AND SEAS 2 TO 3 FEET.
&&
.CLIMATE...
RECORD MIN TEMPS FOR 10/19 (MONDAY)
LOCATION TEMP/YEAR
NEW BERN 33/1948 (KEWN ASOS)
CAPE HATTERAS 39/1978 (KHSE ASOS)
GREENVILLE 33/1970 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 37/1967 (COOP - NOT KMRH ASOS)
KINSTON 30/1973 (COOP - NOT KISO AWOS)
JACKSONVILLE 36/1992 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
SUNDAY FOR AMZ130-131-135.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT
MONDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 4 PM EDT
SUNDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...BM
AVIATION...TL/BM
MARINE...TL/BM
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
230 PM EDT SAT OCT 17 2015
.SYNOPSIS...A DRY COLD FRONT MOVES SOUTH ACROSS THE AREA THROUGH
TONIGHT. COLD HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE FRONT.
HIGH PRESSURE WILL REMAIN OVER THE REGION AT LEAST THROUGH THE
MIDDLE OF THE WEEK AS TEMPERATURES RETURN TO THE NORMAL RANGE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM SATURDAY...
A MID-LEVEL TROUGH CONTINUED TO MAKE PROGRESS TOWARD CENTRAL NORTH
CAROLINA ON WATER VAPOR IMAGERY AS A COLD FRONT MOVED SOUTH ACROSS
VIRGINIA. THIS FRONT WILL USHER INTO CENTRAL NORTH CAROLINA A SURGE
OF COOLER THICKNESSES TONIGHT. THETA-E VALUES REMAIN DRY...AND
PRECIPITABLE WATER VALUES FALL TO NEAR A QUARTER-INCH AS K INDICES
ARE VERY NEGATIVE. IT IS ANTICIPATED THAT...WITH THE PASSAGE OF THE
MID-LEVEL TROUGH AND THE COLD FRONT...ALONG WITH THE SURGE IN COOLER
THICKNESSES AND A MODEST 700MB SHORTWAVE...LOW-LEVEL WINDS SHOULD
INCREASE MODESTLY OR AT LEAST REMAIN STEADY AND NOTICEABLE THROUGH
THE EVENING AND THE EARLY PART OF THE OVERNIGHT. HOWEVER...LATE
TONIGHT...THE CONSENSUS OF THE GUIDANCE SUGGESTS THAT WINDS SHOULD
DIMINISH SUFFICIENTLY ALONG AND WEST OF A LINE FROM ABOUT ALBEMARLE
TO HENDERSON THAT LOW TEMPERATURES...IN THE DRY AIR...COULD GET TO
34 TO 36 IN MANY SPOTS. THE RAP SURFACE GRADIENT ACTUALLY BECOMES
QUITE SLACK BY AROUND 07Z OR SO IN THE NORTHWEST PIEDMONT. GIVEN
THESE EXPECTED CONDITIONS...WILL ISSUE A FROST ADVISORY FOR THAT
AREA. CURRENTLY THINK THAT THE IMMEDIATE TRIAD CITIES WILL HAVE A
HARDER TIME COOLING ENOUGH TO GET MUCH FROST...AS WELL AS THE
INTERIOR OF CITIES SUCH AS CHAPEL HILL AND DURHAM...BUT OUTLYING
AREAS OF THEIR COUNTIES COULD CERTAINLY BE AFFECTED. FARTHER EAST
OVER THE NORTHERN COASTAL PLAIN...THERE SHOULD BE SOME AREAS OF MID
30S BUT WINDS SHOULD STAY UP A LITTLE LONGER. THANKS TO ADJACENT
OFFICES FOR THE COORDINATION WITH REGARD TO THE ADVISORY.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 230 PM SATURDAY...
PRECIPITATBLE WATER VALUES REMAIN LOW SUNDAY AND SUNDAY NIGHT...NEAR
A QUARTER-INCH...WITH NEGATIVE K INDICES AND SUBSIDENCE...AND UPPER-
LEVEL CONFLUENCE PARTICULARLY FROM SUNDAY AFTERNOON THROUGH SUNDAY
NIGHT. 850MB RELATIVE HUMIDITY VALUES ARE EXPECTED TO DIMINISH EVEN
A LITTLE FURTHER LATE SUNDAY NIGHT. WITH CLEAR CONDITIONS AND A
SLACK GRADIENT AS THE SURFACE RIDGE CONTINUES TO BUILD IN FROM THE
NORTHWEST...ALONG WITH DIMINISHING 925MB WINDS...QUITE COOL
TEMPERATURES ARE LIKELY LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING.
HIGH TEMPERATURES SUNDAY WILL STRUGGLE TO GET INTO THE UPPER 50S AND
SHOULD END UP...OVERALL ACROSS CENTRAL NORTH CAROLINA...JUST AROUND
60. OVERNIGHT SUNDAY...THE COMBINATION OF CLEAR SKIES...LIGHT
WINDS...AND DRY AIR SHOULD ALLOW TEMPERATURES TO FALL READILY. WHILE
NOT EXPECTING A HARD FREEZE...ANTICIPATE QUITE A FEW 31S AND 32S
PARTICULARLY OUTSIDE OF THE LARGER CITIES WEST OF A LINE FROM ABOUT
KMEB TO SCOTLAND NECK. FOR THIS FORECAST...WILL ISSUE A FREEZE WATCH
FOR ALL OF CENTRAL NORTH CAROLINA EXCEPT THE FAR SOUTHEAST AND
EASTERN ZONES...WHERE OVERNIGHT LOWS SHOULD BE A LITTLE ABOVE
FREEZING OVERALL AND LOW-LEVEL WINDS FOR MUCH OF THE NIGHT SHOULD BE
JUST A TRIFLE MORE NOTICEABLE. THIS FORECAST WILL NOT FEATURE ANY
RECORD LOWS AT KGSO...KRDU...OR KFAY...BUT IT WILL BE CLOSE
ESPECIALLY AT KRDU...WHERE THE MAV MOS FORECASTS A LOW TEMPERATURE
EARLY MONDAY MORNING JUST A DEGREE ABOVE THE RECORD OF FREEZING...
SET BACK IN 1948.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 100 PM SATURDAY...
MON THROUGH TUE NIGHT EARLY MON MORNING IS LIKELY TO PRESENT US WITH
THE CHILLIEST TEMPS OF THIS STRETCH. THE COLD SURFACE RIDGE WILL
REMAIN EXTENDED ACROSS CENTRAL NC DURING THE PERIOD... WHILE
UNDERGOING STEADY SLOW AIR MASS MODIFICATION. CLOUDS WILL BE FEW IN
NUMBER TO NONE THROUGH TUE NIGHT AS HEIGHTS BUILD ALOFT OVER THE
GULF AND SOUTHEAST STATES (A FUNCTION OF A DEEPENING LOW OVER NW MEX
AND ADJACENT CA/AZ) WITH DEEP DRY AIR AND SUBSIDENCE OVER NC... AND
EVEN THE PASSAGE OF A WEAK VORTICITY MAX LATE MON NIGHT INTO TUE
MORNING WILL HAVE LITTLE NO MOISTURE TO WORK WITH... YIELDING A FEW
HIGH THIN CLOUDS AT MOST. A SHALLOW BUT DRY ADIABATIC MIXED LAYER
MON ALONG WITH STATISTICAL GUIDANCE AND ANOMALOUSLY LOW THICKNESSES
(STARTING THE DAY AROUND 45-50 M BELOW NORMAL) SUGGESTS HIGHS OF 56-
62. WIND SPEEDS SHOULD ONCE AGAIN DROP TO 0-2 KTS MON NIGHT WITH
DECOUPLING... AND WITH CLEAR SKIES... EXPECT LOWS OF 32-38. OUTLYING
AREAS HAVE ONE MORE SHOT AT SOME FROST. MORE OF THE SAME TUE WITH
DEEPLY DRY AND STABLE AIR... ALTHOUGH THE SURFACE RIDGE WILL BE
LOSING STEAM OVERHEAD... GIVING WAY TO ENOUGH LOW LEVEL WARMING TO
PUSH THICKNESSES UP TO JUST 20-25 M BELOW NORMAL... AS THE WARMER
AIR ALOFT FINALLY STARTS TO WORK DOWN TO THE SURFACE. HIGHS 64-68.
ANOTHER GOOD NIGHT OF RADIATIONAL COOLING TUE NIGHT... BUT THE
DEWPOINTS WILL BE HIGHER WITH THE MODIFIED AIR MASS... ESPECIALLY IN
THE SE CWA. LOWS 38-45.
WED-SAT: WARM FOR A COUPLE OF DAYS... THEN BACK TO A LITTLE BELOW
NORMAL FOR A COUPLE OF DAYS... BUT STILL NO SIGNIFICANT PRECIP IN
SIGHT. THE MID LEVEL RIDGE COVERING THE GULF COAST/GULF STATES AND
SOUTHEAST STATES WED STARTS TO RETROGRADE IN RESPONSE TO POLAR-
STREAM SHORTWAVE ENERGY DIVING SE THROUGH NEW ENGLAND/NORTHEAST
STATES LATE THU/THU NIGHT... AND PASSAGE AT THE SURFACE OF AN
ASSOCIATED BACKDOOR COLD FRONT THROUGH NC. THE ENHANCED NW FLOW
ALOFT SHOULD BRING SOME POCKETS OF WEAK VORTICITY DOWN THROUGH NC
THU NIGHT... BUT ONCE AGAIN THERE IS NO OPPORTUNITY FOR SUBSTANTIAL
MOISTURE ADVECTION... INDICATING LITTLE IN THE WAY OF SKY COVER. THE
LONE EXCEPTION MAY BE EARLY FRI ACROSS THE SOUTH AND WEST WHERE LOW
LEVEL ATLANTIC-SOURCE MOIST UPGLIDE COULD HELP GENERATE SOME
STRATOCU. BUT OTHERWISE... ANY MOISTURE IS TOO SHALLOW OR FLEETING
FOR ANY MEASURABLE PRECIP... AND EXPECT JUST PARTLY CLOUDY SKIES AT
WORST LATE THU NIGHT INTO EARLY FRI. HIGHS IN THE LOW-MID 70S
WED/THU... SLIPPING BACK TO THE MID 60S TO AROUND 70 FRI/SAT.
WARMEST LOWS THU NIGHT IN THE UPPER 40S TO LOWER 50S... BUT
OTHERWISE EXPECT LOWS IN THE MID 40S TO NEAR 50. -GIH
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 130 PM SATURDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE 18Z VALID TAF PERIOD. THERE
WILL BE A FEW WIND GUSTS IN THE TEENS KNOTS THIS AFTERNOON...AND
THEN AGAIN WITH MIXING ON SUNDAY...THERE SHOULD BE MORE WIND GUSTS
IN THE TEENS TO NEAR 20 KNOTS ACROSS CENTRAL NORTH CAROLINA. BEYOND
THE 18Z VALID TAF PERIOD...VFR CONDITIONS ARE EXPECTED THROUGH
WEDNESDAY...AND LARGELY INTO THURSDAY. THE LATEST GFS GUIDANCE
SUGGESTS...TOWARD KFAY...THE POTENTIAL FOR A PERIOD OF CEILINGS NEAR
MVFR OVERNIGHT WEDNESDAY INTO THURSDAY MORNING.
&&
.CLIMATE...
RECORD LOW TEMPERATURES FOR OCTOBER 19...
KGSO...28 DEGREES IN 1948.
KRDU...32 DEGREES IN 1948.
KFAY...32 DEGREES IN 1931.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE SUNDAY NIGHT THROUGH EARLY MONDAY MORNING FOR
NCZ007>011-021>027-038>042-073>077-083-084.
FROST ADVISORY FROM 4 AM TO 9 AM EDT SUNDAY FOR NCZ007>009-
021>025-038-039-073.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...HARTFIELD
AVIATION...DJF
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 PM EDT SAT OCT 17 2015
.SYNOPSIS...A DRY COLD FRONT MOVES SOUTH ACROSS THE AREA THROUGH
TONIGHT. COLD HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE FRONT.
HIGH PRESSURE WILL REMAIN OVER THE REGION AT LEAST THROUGH THE
MIDDLE OF THE WEEK AS TEMPERATURES RETURN TO THE NORMAL RANGE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 915 AM SATURDAY...
A BAND OF HIGH SC AND LOW AC WAS LOCATED OVER THE FAR SOUTHEAST PART
OF CENTRAL NORTH CAROLINA EARLY THIS MORNING...IN CENTRAL NORTH
CAROLINA SOUTH OF KCTZ TOWARD HARRELLS. ASSOCIATED WITH A SHALLOW
VOLUME OF MOISTURE AROUND 800MB...THE RAP SUGGESTS THAT 800MB
MOISTURE MOVES OFF TO THE SOUTHEAST THIS MORNING...AND RAP SOUNDINGS
FROM NEAR KFAY FORECAST DRYING AROUND 800MB THIS MORNING AND INTO
THE AFTERNOON. OTHERWISE...AHEAD OF A MID-LEVEL TROUGH SHOWN ON
WATER VAPOR IMAGERY MOVING EAST TOWARD THE CAROLINAS...WHILE THERE
SHOULD BE UPPER-LEVEL DIFFLUENCE TODAY THE WATER VAPOR IMAGERY SHOWS
GOOD DRY AIR OVER CENTRAL NORTH CAROLINA AND RAP SOUNDINGS INDICATE
CONSIDERABLE DRY AIR IN THE COLUMN. K INDICES ARE NEGATIVE...AND
850MB THETA-E VALUES DECREASE DURING THE DAY...ESPECIALLY SOUTHEAST.
WITH MIXING...THE 12Z GSO AND RAP FORECAST SOUNDINGS SUGGEST A FEW
GUSTS POSSIBLE AROUND 15KT...ESPECIALLY TOWARD THE TRIAD AND
TRIANGLE. 1000-850MB THICKNESSES AND THE TEMPERATURE FORECAST FROM
THOSE COINCIDE WITH THE CONSENSUS OF MOS GUIDANCE...MID TO UPPER 60S
IN THE NORTHWEST PIEDMONT AND MOSTLY AROUND 70 ELSEWHERE...SOLID
LOWER 70S TOWARD KFAY AND KCTZ.
TONIGHT...A SECONDARY REINFORCING COLD IS EXPECTED TO MOVE THROUGH
THE AREA THIS EVENING INTO TONIGHT... AS ANOTHER S/W IN THE L/W
TROUGH MOVES ACROSS THE NORTHEAST U.S. THE FRONT SHOULD BE DRY AND
ONLY DELIVER A COLDER/DRIER AIRMASS TO CENTRAL NC...ALONG WITH AND
INCREASE IN WINDS THIS EVENING INTO EARLY SUNDAY MORNING. WINDS WILL
BEGIN TO WEAKEN CLOSER TO DAYBREAK SUNDAY ACROSS THE NORTHERN PART
OF THE CWA. HOWEVER...WITH EXPECTED LOW TEMPS A BIT WARMER THAN
PREVIOUS FORECASTS AND DEWPOINT DEPRESSIONS EXPECTED TO BE A BIT
HIGHER WILL NOT ISSUE A FROST ADVISORY AT THIS TIME. LOW TEMPS ARE
EXPECTED TO RANGE FROM THE MID TO UPPER 30S...WITH A FEW LOCATIONS
ACROSS THE SOUTH/SOUTHEAST NEAR 40. EXPECT SOME OF THE MORE
SHELTERED RURAL USUAL COLD LOCATIONS ACROSS THE NORTH MAY SEE SOME
PATCHY FROST THOUGH.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM SATURDAY...
CANADIAN HIGH PRESSURE WILL BUILD ACROSS THE REGION ON SUNDAY INTO
SUNDAY NIGHT IN THE WAKE OF THE COLD FRONT. THIS WILL USHER IN MUCH
COOLER/COLDER AIR INTO CENTRAL NC. DESPITE SUNNY SKIES... HIGH TEMPS
WILL STRUGGLE TO REACH 60 DEGREES. EXPECT HIGH TEMPS WILL RANGE FROM
THE MID TO UPPER 50S... WITH A FEW LOCATIONS ACROSS FAR SOUTHERN
PORTIONS OF CENTRAL NC TOUCHING 60 DEGREES SUNDAY AFTERNOON. WITH
THE PRESSURE GRADIENT WEAKENING OVER THE AREA NEAR DAYBREAK MONDAY
MORNING WE WILL LIKELY SEE THE COLDEST TEMPS OF THE SEASON TO DATE.
LOW TEMPS BY MONDAY MORNING ARE EXPECTED TO BE IN LOW TO MID 30S. AT
LEAST A FROST ADVISORY SEEMS LIKELY AREAWIDE FUTURE FORECASTS...
WITH POTENTIALLY EVEN A FREEZE WARNING ACROSS THE PIEDMONT AND
NORTHERN COASTAL PLAIN.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 100 PM SATURDAY...
MON THROUGH TUE NIGHT EARLY MON MORNING IS LIKELY TO PRESENT US WITH
THE CHILLIEST TEMPS OF THIS STRETCH. THE COLD SURFACE RIDGE WILL
REMAIN EXTENDED ACROSS CENTRAL NC DURING THE PERIOD... WHILE
UNDERGOING STEADY SLOW AIR MASS MODIFICATION. CLOUDS WILL BE FEW IN
NUMBER TO NONE THROUGH TUE NIGHT AS HEIGHTS BUILD ALOFT OVER THE
GULF AND SOUTHEAST STATES (A FUNCTION OF A DEEPENING LOW OVER NW MEX
AND ADJACENT CA/AZ) WITH DEEP DRY AIR AND SUBSIDENCE OVER NC... AND
EVEN THE PASSAGE OF A WEAK VORTICITY MAX LATE MON NIGHT INTO TUE
MORNING WILL HAVE LITTLE NO MOISTURE TO WORK WITH... YIELDING A FEW
HIGH THIN CLOUDS AT MOST. A SHALLOW BUT DRY ADIABATIC MIXED LAYER
MON ALONG WITH STATISTICAL GUIDANCE AND ANOMALOUSLY LOW THICKNESSES
(STARTING THE DAY AROUND 45-50 M BELOW NORMAL) SUGGESTS HIGHS OF 56-
62. WIND SPEEDS SHOULD ONCE AGAIN DROP TO 0-2 KTS MON NIGHT WITH
DECOUPLING... AND WITH CLEAR SKIES... EXPECT LOWS OF 32-38. OUTLYING
AREAS HAVE ONE MORE SHOT AT SOME FROST. MORE OF THE SAME TUE WITH
DEEPLY DRY AND STABLE AIR... ALTHOUGH THE SURFACE RIDGE WILL BE
LOSING STEAM OVERHEAD... GIVING WAY TO ENOUGH LOW LEVEL WARMING TO
PUSH THICKNESSES UP TO JUST 20-25 M BELOW NORMAL... AS THE WARMER
AIR ALOFT FINALLY STARTS TO WORK DOWN TO THE SURFACE. HIGHS 64-68.
ANOTHER GOOD NIGHT OF RADIATIONAL COOLING TUE NIGHT... BUT THE
DEWPOINTS WILL BE HIGHER WITH THE MODIFIED AIR MASS... ESPECIALLY IN
THE SE CWA. LOWS 38-45.
WED-SAT: WARM FOR A COUPLE OF DAYS... THEN BACK TO A LITTLE BELOW
NORMAL FOR A COUPLE OF DAYS... BUT STILL NO SIGNIFICANT PRECIP IN
SIGHT. THE MID LEVEL RIDGE COVERING THE GULF COAST/GULF STATES AND
SOUTHEAST STATES WED STARTS TO RETROGRADE IN RESPONSE TO POLAR-
STREAM SHORTWAVE ENERGY DIVING SE THROUGH NEW ENGLAND/NORTHEAST
STATES LATE THU/THU NIGHT... AND PASSAGE AT THE SURFACE OF AN
ASSOCIATED BACKDOOR COLD FRONT THROUGH NC. THE ENHANCED NW FLOW
ALOFT SHOULD BRING SOME POCKETS OF WEAK VORTICITY DOWN THROUGH NC
THU NIGHT... BUT ONCE AGAIN THERE IS NO OPPORTUNITY FOR SUBSTANTIAL
MOISTURE ADVECTION... INDICATING LITTLE IN THE WAY OF SKY COVER. THE
LONE EXCEPTION MAY BE EARLY FRI ACROSS THE SOUTH AND WEST WHERE LOW
LEVEL ATLANTIC-SOURCE MOIST UPGLIDE COULD HELP GENERATE SOME
STRATOCU. BUT OTHERWISE... ANY MOISTURE IS TOO SHALLOW OR FLEETING
FOR ANY MEASURABLE PRECIP... AND EXPECT JUST PARTLY CLOUDY SKIES AT
WORST LATE THU NIGHT INTO EARLY FRI. HIGHS IN THE LOW-MID 70S
WED/THU... SLIPPING BACK TO THE MID 60S TO AROUND 70 FRI/SAT.
WARMEST LOWS THU NIGHT IN THE UPPER 40S TO LOWER 50S... BUT
OTHERWISE EXPECT LOWS IN THE MID 40S TO NEAR 50. -GIH
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 130 PM SATURDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE 18Z VALID TAF PERIOD. THERE
WILL BE A FEW WIND GUSTS IN THE TEENS KNOTS THIS AFTERNOON...AND
THEN AGAIN WITH MIXING ON SUNDAY...THERE SHOULD BE MORE WIND GUSTS
IN THE TEENS TO NEAR 20 KNOTS ACROSS CENTRAL NORTH CAROLINA. BEYOND
THE 18Z VALID TAF PERIOD...VFR CONDITIONS ARE EXPECTED THROUGH
WEDNESDAY...AND LARGELY INTO THURSDAY. THE LATEST GFS GUIDANCE
SUGGESTS...TOWARD KFAY...THE POTENTIAL FOR A PERIOD OF CEILINGS NEAR
MVFR OVERNIGHT WEDNESDAY INTO THURSDAY MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/77
SHORT TERM...77
LONG TERM...HARTFIELD
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
132 PM EDT SAT OCT 17 2015
.SYNOPSIS...A DRY COLD FRONT MOVES SOUTH ACROSS THE AREA THROUGH
TONIGHT. COLD HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE FRONT.
HIGH PRESSURE WILL REMAIN OVER THE REGION AT LEAST THROUGH THE
MIDDLE OF THE WEEK AS TEMPERATURES RETURN TO THE NORMAL RANGE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 915 AM SATURDAY...
A BAND OF HIGH SC AND LOW AC WAS LOCATED OVER THE FAR SOUTHEAST PART
OF CENTRAL NORTH CAROLINA EARLY THIS MORNING...IN CENTRAL NORTH
CAROLINA SOUTH OF KCTZ TOWARD HARRELLS. ASSOCIATED WITH A SHALLOW
VOLUME OF MOISTURE AROUND 800MB...THE RAP SUGGESTS THAT 800MB
MOISTURE MOVES OFF TO THE SOUTHEAST THIS MORNING...AND RAP SOUNDINGS
FROM NEAR KFAY FORECAST DRYING AROUND 800MB THIS MORNING AND INTO
THE AFTERNOON. OTHERWISE...AHEAD OF A MID-LEVEL TROUGH SHOWN ON
WATER VAPOR IMAGERY MOVING EAST TOWARD THE CAROLINAS...WHILE THERE
SHOULD BE UPPER-LEVEL DIFFLUENCE TODAY THE WATER VAPOR IMAGERY SHOWS
GOOD DRY AIR OVER CENTRAL NORTH CAROLINA AND RAP SOUNDINGS INDICATE
CONSIDERABLE DRY AIR IN THE COLUMN. K INDICES ARE NEGATIVE...AND
850MB THETA-E VALUES DECREASE DURING THE DAY...ESPECIALLY SOUTHEAST.
WITH MIXING...THE 12Z GSO AND RAP FORECAST SOUNDINGS SUGGEST A FEW
GUSTS POSSIBLE AROUND 15KT...ESPECIALLY TOWARD THE TRIAD AND
TRIANGLE. 1000-850MB THICKNESSES AND THE TEMPERATURE FORECAST FROM
THOSE COINCIDE WITH THE CONSENSUS OF MOS GUIDANCE...MID TO UPPER 60S
IN THE NORTHWEST PIEDMONT AND MOSTLY AROUND 70 ELSEWHERE...SOLID
LOWER 70S TOWARD KFAY AND KCTZ.
TONIGHT...A SECONDARY REINFORCING COLD IS EXPECTED TO MOVE THROUGH
THE AREA THIS EVENING INTO TONIGHT... AS ANOTHER S/W IN THE L/W
TROUGH MOVES ACROSS THE NORTHEAST U.S. THE FRONT SHOULD BE DRY AND
ONLY DELIVER A COLDER/DRIER AIRMASS TO CENTRAL NC...ALONG WITH AND
INCREASE IN WINDS THIS EVENING INTO EARLY SUNDAY MORNING. WINDS WILL
BEGIN TO WEAKEN CLOSER TO DAYBREAK SUNDAY ACROSS THE NORTHERN PART
OF THE CWA. HOWEVER...WITH EXPECTED LOW TEMPS A BIT WARMER THAN
PREVIOUS FORECASTS AND DEWPOINT DEPRESSIONS EXPECTED TO BE A BIT
HIGHER WILL NOT ISSUE A FROST ADVISORY AT THIS TIME. LOW TEMPS ARE
EXPECTED TO RANGE FROM THE MID TO UPPER 30S...WITH A FEW LOCATIONS
ACROSS THE SOUTH/SOUTHEAST NEAR 40. EXPECT SOME OF THE MORE
SHELTERED RURAL USUAL COLD LOCATIONS ACROSS THE NORTH MAY SEE SOME
PATCHY FROST THOUGH.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM SATURDAY...
CANADIAN HIGH PRESSURE WILL BUILD ACROSS THE REGION ON SUNDAY INTO
SUNDAY NIGHT IN THE WAKE OF THE COLD FRONT. THIS WILL USHER IN MUCH
COOLER/COLDER AIR INTO CENTRAL NC. DESPITE SUNNY SKIES... HIGH TEMPS
WILL STRUGGLE TO REACH 60 DEGREES. EXPECT HIGH TEMPS WILL RANGE FROM
THE MID TO UPPER 50S... WITH A FEW LOCATIONS ACROSS FAR SOUTHERN
PORTIONS OF CENTRAL NC TOUCHING 60 DEGREES SUNDAY AFTERNOON. WITH
THE PRESSURE GRADIENT WEAKENING OVER THE AREA NEAR DAYBREAK MONDAY
MORNING WE WILL LIKELY SEE THE COLDEST TEMPS OF THE SEASON TO DATE.
LOW TEMPS BY MONDAY MORNING ARE EXPECTED TO BE IN LOW TO MID 30S. AT
LEAST A FROST ADVISORY SEEMS LIKELY AREAWIDE FUTURE FORECASTS...
WITH POTENTIALLY EVEN A FREEZE WARNING ACROSS THE PIEDMONT AND
NORTHERN COASTAL PLAIN.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...
DRY WEATHER WEATHER WILL PERSIST THROUGH THE LONG TERM AS BROAD/FLAT
UPPER LEVEL RIDGE CONTINUES OVER THE DEEP SOUTH THROUGH THE TN
VALLEY...AND ASSOCIATED SFC RIDGE EXTENDS SW-NE ACROSS CENTRAL NC.
LOW LEVEL THICKNESSES AT THE START OF THE PERIOD AVERAGE A SOLID 30-
35M BELOW NORMAL...YIELDING MAX TEMPS MONDAY IN THE 50S TO AROUND
60. AIR MASS MODIFIES TUESDAY THROUGH WEDNESDAY WITH TEMPS RETURNING
TO NEAR NORMAL LEVELS (UPPER 60S-LOWER 70S) BY MID WEEK.
UPPER RIDGE AMPLIFIES FROM THE DEEP SOUTH INTO THE LOWER GREAT LAKES
THURSDAY INTO FRIDAY IN RESPONSE TO A DEEPENING UPPER LEVEL LOW OVER
THE DESERT SW. THIS WILL CAUSE OUR UPPER LEVEL FLOW TO BECOME NWLY.
THIS SET-UP WILL CAUSE A S/W TO CROSS SOUTHERN NEW ENGLAND-NORTHERN
MID ATLANTIC THURSDAY. THIS FEATURE WILL PROPEL A SURFACE COLD FRONT
SEWD INTO CENTRAL NC THURSDAY NIGHT THROUGH FRIDAY MORNING. MODEL
GUIDANCE HAS BEEN FAIRLY CONSISTENT WITH THE TIMING OF THIS SURFACE
FEATURE.
MOISTURE ADVECTION AHEAD OF THE SFC FRONT THURSDAY NIGHT IS WEAK AT
BEST SO EXPECT NOTHING MORE THAN PATCHY CLOUDINESS ASSOCIATED WITH
THE FRONTAL PASSAGE. NLY FLOW BEHIND THE FRONT WILL USHER IN A FRESH
BATCH OF COOLER AIR FOR THE WEEKEND.
EXPECT THURSDAY TO BE THE WARMEST DAY IN THE UPCOMING WEEK AS
THICKNESSES AVERAGE 5-8M ABOVE NORMAL SUPPORTIVE OF AFTERNOON TEMPS
IN THE 70-75 DEGREE RANGE. A SLIGHT COOL DOWN EXPECTED FRIDAY AS SFC
FLOW BEGINS TO ADVECT THE COOLER AIR MASS INTO THE REGION.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 130 PM SATURDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE 18Z VALID TAF PERIOD. THERE
WILL BE A FEW WIND GUSTS IN THE TEENS KNOTS THIS AFTERNOON...AND
THEN AGAIN WITH MIXING ON SUNDAY...THERE SHOULD BE MORE WIND GUSTS
IN THE TEENS TO NEAR 20 KNOTS ACROSS CENTRAL NORTH CAROLINA. BEYOND
THE 18Z VALID TAF PERIOD...VFR CONDITIONS ARE EXPECTED THROUGH
WEDNESDAY...AND LARGELY INTO THURSDAY. THE LATEST GFS GUIDANCE
SUGGESTS...TOWARD KFAY...THE POTENTIAL FOR A PERIOD OF CEILINGS NEAR
MVFR OVERNIGHT WEDNESDAY INTO THURSDAY MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/77
SHORT TERM...77
LONG TERM...WSS
AVIATION...DJF