Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/13/16


AREA FORECAST DISCUSSION
NWS ALBANY NY
950 PM EST FRI FEB 12 2016 .SYNOPSIS... AN ARCTIC COLD FRONT WILL SWEEP ACROSS THE REGION OVERNIGHT WITH SCATTERED SNOW SHOWERS AND ISOLATED SNOW SQUALLS AHEAD OF IT. BEHIND THE ARCTIC COLD FRONT...THE COLDEST AIRMASS OF THE SEASON WILL BUILD ACROSS THE REGION FOR THE WEEKEND WITH BITTERLY COLD TEMPERATURES AND WIND CHILLS. A STORM SYSTEM MAY IMPACT THE REGION MONDAY INTO THE MID WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 949 PM EST...AN ARCTIC COLD FRONT WILL BE MOVING THROUGH THE REGION BTWN 04Z /11 PM/ AND 10Z /5 AM/ FROM NW TO SE. AHEAD OF THIS FRONTAL BOUNDARY THERE WILL BE SCATTERED SNOW SHOWERS AND PERHAPS A FEW EMBEDDED SNOW SQUALLS...ESPECIALLY NORTH AND WEST OF THE CAPITAL REGION. THE LATEST 3-KM HRRR SHOWS THE CURRENT BAND OF SNOW SHOWERS CURRENTLY WEST OF THE FCST ON THE LOCAL AND MOSAIC RADAR IMAGERY MOVING INTO THE MOHAWK VALLEY...ADIRONDACKS...AND CATSKILLS...AND THEN WEAKENING AS IT MOVES FURTHER DOWN STREAM TOWARDS THE HUDSON RIVER VALLEY. SNOWFALL AMOUNTS ARE EXPECTED TO BE ON THE LIGHT SIDE WITH GENERALLY A DUSTING TO 2 INCHES. THE HIGHER TOTALS WILL BE OVER THE WRN DACKS. ANY SNOW SQUALLS WOULD LIKELY REDUCE VISIBILITIES TO UNDER A QUARTER MILE BRIEFLY FOR A SHORT PERIOD OF TIME. SOME CHANGES WERE MADE TO THE POPS/CLOUDS/TEMPS BASED ON THE LATEST HRRR AND NAM12. IT WILL BE ANOTHER VERY COLD NIGHT...BUT NOT AS COLD AS THE TEMPERATURES LATER IN THE WEEKEND. LOWS OVERNIGHT WILL RANGE FROM 10 BELOW ZERO NORTHWEST AREAS TO 15 ABOVE ZERO SOUTHEAST TOWARDS NW CT AND THE MID HUDSON RIVER VALLEY. WINDS WILL ALSO INCREASE OVERNIGHT ACROSS THE FCST AREA WITH A WIND CHILL WARNING STARTING AT 3 AM FOR THE SOUTHERN ADIRONDACKS...WESTERN MOHAWK VALLEY...EASTERN CATSKILLS AND SOUTHERN VERMONT. THE JAIL BREAK OF ARCTIC AIR KICKS IN...AS THE WINDS BEHIND THE FRONT WILL BE MAINLY WEST TO SOUTHWEST AT 10 TO 20 MPH WITH GUSTS TO 30-40 MPH. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... WIND CHILL WARNINGS IN EFFECT FOR SATURDAY-SUNDAY MORNING FOR ALL OF EASTERN NEW YORK AND ADJACENT WESTERN NEW ENGLAND. THE COLDEST AIRMASS OF THE SEASON WILL BE WITH US OVER THE WEEKEND IN THE WAKE OF THE ARCTIC FRONT AS AN ARCTIC AREA OF HIGH PRESSURE SETTLES OVER THE REGION BY SUNDAY. H8 TEMPS DROP TO 27 TO 34 DEGREES BELOW ZERO BY SATURDAY EVENING. HAVE GONE WITH A NON- DIURNAL RANGE OF TEMPS ON SATURDAY AS THE LOWS FRIDAY NIGHT AND THE HIGHS ON SATURDAY SHOULD BE THE SAME WITH THE TEMPS DROPPING ALL DAY ON SATURDAY. TEMPS ARE EXPECTED TO DROP FROM 10 BELOW TO 15 ABOVE ZERO EARLY SATURDAY MORNING TO 15 BELOW ZERO TO 5 ABOVE ZERO BY EARLY SATURDAY EVENING. WIND CHILLS ON SATURDAY WILL RANGE FROM 10 BELOW TO 35 BELOW ZERO WITH NORTHWEST WINDS 10 TO 20 MPH WITH GUSTS 30 TO 40 MPH. SATURDAY NIGHT WILL BE ESPECIALLY BRUTAL AS AIR TEMPERATURES ARE EXPECTED TO DROP TO 5 BELOW TO NEAR 30 BELOW ZERO WITH WIND CHILL VALUES 25 BELOW TO NEAR 50 BELOW ZERO. SUNDAY INTO SUNDAY NIGHT...HIGH PRESSURE WILL MOVE OVER OUR REGION ON SUNDAY AND OFF THE EASTERN SEABOARD LATE SUNDAY NIGHT. WINDS WILL STILL BE FAIRLY STRONG ON SUNDAY MORNING BEFORE SUBSIDING LATER SUNDAY INTO SUNDAY NIGHT. HIGHS ON SUNDAY WILL BE IN THE ZERO TO 15 ABOVE ZERO RANGE WITH THE LOWS SUNDAY NIGHT BETWEEN 10 BELOW AND 5 ABOVE ZERO. MONDAY WILL FEATURE INCREASING CLOUDS AS THE NEXT SYSTEM STARTS TO TRACK NORTHEASTWARD FROM THE SOUTHEAST COAST. HIGHS WILL MODERATE ON MONDAY RANGING FROM THE UPPER TEENS NORTHWEST TO UPPER 20S SOUTHEAST WITH A CHANCE OF SNOW ACROSS THE SOUTHERN HALF OF THE FA LATE IN THE DAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A SIGNIFICANT STORM IS EXPECTED TO IMPACT THE REGION DURING THE EARLY PART OF THE EXTENDED PERIOD. THERE IS INCREASING CONFIDENCE AS TO THE TRACK AND INTENSITY OF THIS SYSTEM... AT LEAST IN ITS EARLY STAGES. TWO TO SIX INCH ACCUMULATIONS ARE EXPECTED MONDAY NIGHT... WHICH IS MORE OR LESS THE START OF THE EVENT. BEYOND THAT THERE IS STILL UNCERTAINTY AS TO PRECIPITATION TYPE AS THERE IS PLENTY OF MILD AIR TO BE DRAWN IN OUT AHEAD OF THIS SYSTEM...THUS THE EXACT TRACK AND INTENSITY WILL BE CRUCIAL. RIGHT NOW...THE TRACK IS EXPECTED TO BE FROM ABOUT CHARLOTTE NORTH CAROLINA THROUGH ALBANY. BECAUSE THE TRACK IS NOT SEEN AS GOING FAR ENOUGH TO THE EAST TO GIVE US AN ALL SNOW EVENT...INDICATIONS ARE PRECIPITATION WILL LIKELY CHANGE OVER TO RAIN FOR A TIME ON TUESDAY...PARTICULARLY OUTSIDE OF THE ADIRONDACKS...BEFORE EVERYTHING TAPERS OFF AS SNOW TUESDAY NIGHT. THERE IS THE POTENTIAL FOR VERY SIGNIFICANT ACCUMULATIONS...BUT ANY DECENT PERIOD OF RAIN...AS IS EXPECTED RIGHT NOW...WILL KEEP SNOW ACCUMULATIONS AT BAY. BROAD LAKE ENHANCEMENT ON INCREASING WESTERLY WINDS BEHIND THE DEPARTING STORM WILL KEEP SNOW SHOWERS OF LIGHT AMOUNTS GOING FOR MANY AREAS TUESDAY NIGHT...WITH MIXED RAIN AND SNOW SHOWERS FOR WEDNESDAY. BUT THE ACTIVITY WILL WIND DOWN RAPIDLY ON THURSDAY AS HIGH PRESSURE SETTLES IN...BUT WITHOUT THE EXTREME COLD WE/RE EXPECTING THIS WEEKEND. HIGH TEMPERATURES ARE EXPECTED TO RANGE FROM THE MID 30S THROUGH THE UPPER 40S ON TUESDAY...THE UPPER 20S TO AROUND 40 DEGREES ON WEDNESDAY...AND THE MID TEENS TO AROUND 30 DEGREES ON THURSDAY. FRIDAY HIGHS WILL REBOUND SOMEWHAT. OVERNIGHT LOWS MONDAY NIGHT WILL RANGE FROM THE UPPER TEENS IN THE MOUNTAINS TO THE UPPER 20S IN THE LOWER MID HUDSON VALLEY. TUESDAY NIGHT...THEY WILL RANGE FROM THE MID 20S IN THE WESTERN ADIRONDACKS...TO THE LOWER 30S DOWN THE HUDSON VALLEY. WEDNESDAY NIGHT WILL TURN SHARPLY COLDER...AND THURSDAY NIGHT WILL BE COLDEST...WITH LOWS RANGING FROM THE LOW SINGLE DIGITS IN THE WESTERN ADIRONDACKS...TO THE UPPER TEENS DOWN THE MID HUDSON VALLEY. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... A CLIPPER LOW WILL PASS NORTH OF THE REGION TONIGHT...AS THE ARCTIC COLD FRONT WILL MOVE THROUGH OVERNIGHT. A NW FLOW OF ARCTIC AIR WILL IMPACT THE REGION THROUGH THE DAY INTO THE NIGHT PERIOD WITH GUSTY WINDS. THE ARCTIC FRONT WILL FOCUS SOME ISOLATED TO SCATTERED SNOW SHOWERS OR A SQUALL FROM THE CAPITAL REGION NORTH...IMPACTING KGFL/KALB/KPSF BTWN 04Z-09Z. THE SNOW SHOWERS WILL BE FAIRLY ISOLATED TO SCATTERED IN COVERAGE DUE TO VERY LIMITED LOW-LEVEL MOISTURE. A VCSH WAS USED AT KALB/KPSF AFTER 05Z...AND A TEMPO WAS USED FOR MVFR CONDITIONS AT KGFL BTWN 04Z-06Z. VFR CONDITIONS WILL BE DOMINATE...ASIDE FOR SOME MVFR CIGS/VSBYS WITH ANY SNOW SHOWERS/ISOLD SQUALLS ESPECIALLY AT KPSF/KGFL. CIGS WILL BE MAINLY IN THE 4-9 KFT AGL RANGE. IN THE WAKE OF THE FRONT LATE TOMORROW MORNING...SOME LINGERING STRATOCUMULUS OR MID LEVEL CLOUDS WILL LINGER. OVERALL...VFR CONDITIONS WILL CONTINUE IN THE FRIGID NORTHWEST FLOW THROUGH THE PM. THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 4-10 KTS PRIOR TO MIDNIGHT...THEN VEER TO THE W TO NW AT 6-12 KTS BEFORE DAYBREAK WITH SOME GUSTS TO 20-25 KTS. THE WINDS WILL INCREASE IN THE WAKE OF THE ARCTIC FRONT LATE TOMORROW MORNING INTO THE AFTERNOON AT 12-20 KTS WITH SOME GUSTS AROUND 30 KTS...ESPECIALLY AT KALB/KPSF. OUTLOOK... SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SN. SUNDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SN. WASHINGTONS BIRTHDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...SN. MONDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... WITH BITTER COLD AIR IN PLACE...ICE COVERAGE ON RIVERS AND LAKES WILL CONTINUE TO INCREASE AND STRENGTHEN OVER THE NEXT FEW DAYS. A FEW LIGHT SNOW SHOWERS ARE POSSIBLE...MAINLY THIS EVENING...BUT THIS WILL AMOUNT TO LITTLE IF ANY HYDROLOGIC SIGNIFICANCE. HOWEVER...THERE IS THE POTENTIAL FOR A HEAVY PRECIPITATION EVENT TO IMPACT THE REGION FROM MONDAY NIGHT THROUGH WEDNESDAY. THERE REMAINS CONSIDERABLE UNCERTAINTY REGARDING THE TYPES OF PRECIPITATION THAT MAY OCCUR...WHICH WILL ULTIMATELY DEPEND ON THE EXACT TRACK OF THIS POTENTIAL STORM SYSTEM. AT THIS TIME...MODEL GUIDANCE IS SUGGESTING ONE TO THREE INCHES OF LIQUID EQUIVALENT COULD OCCUR...AND MUCH OF THIS COULD BE IN THE FORM OF RAIN. IF THIS RAIN WERE TO MATERIALIZE...IT COULD HAVE A HIGH IMPACT ON RIVERS AND STREAMS...ESP CONSIDERING THE GROUND WILL BE FULLY FROZEN BY THAT TIME...ALLOWING MUCH OF THE PRECIP TO BE RUNOFF. DETAILS WILL BECOME MORE CERTAIN OVER THE NEXT FEW DAYS. 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...WIND CHILL WARNING FROM 1 PM SATURDAY TO 1 PM EST SUNDAY FOR CTZ001-013. NY...WIND CHILL WARNING FROM 3 AM SATURDAY TO 1 PM EST SUNDAY FOR NYZ032-033-038-042-047-051-058-063-082. WIND CHILL WARNING FROM 1 PM SATURDAY TO 1 PM EST SUNDAY FOR NYZ039>041-043-048>050-052>054-059>061-064>066-083-084. MA...WIND CHILL WARNING FROM 1 PM SATURDAY TO 1 PM EST SUNDAY FOR MAZ001-025. VT...WIND CHILL WARNING FROM 3 AM SATURDAY TO 1 PM EST SUNDAY FOR VTZ013>015. && $$ SYNOPSIS...IRL/WASULA NEAR TERM...11/WASULA SHORT TERM...11 LONG TERM...ELH AVIATION...WASULA HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
714 PM EST FRI FEB 12 2016 .SYNOPSIS... AN ARCTIC COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT WITH SCATTERED SNOW SHOWERS AND ISOLATED SNOW SQUALLS AHEAD OF IT. BEHIND THE ARCTIC COLD FRONT...THE COLDEST AIRMASS OF THE SEASON WILL BUILD ACROSS THE REGION FOR THE WEEKEND WITH BITTERLY COLD TEMPERATURES AND WIND CHILLS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 635 PM EST...AN ARCTIC COLD FRONT WILL BE MOVING THROUGH THE REGION LATER THIS EVENING THROUGH THE OVERNIGHT HOURS. AHEAD OF THIS FRONTAL BOUNDARY THERE WILL BE SCATTERED SNOW SHOWERS AND PERHAPS A FEW EMBEDDED SNOW SQUALLS. SNOWFALL AMOUNTS ARE EXPECTED TO BE ON THE LIGHT SIDE WITH GENERALLY A DUSTING TO 2 INCHES. ANY SNOW SQUALLS WOULD LIKELY REDUCE VISIBILITY SIGNIFICANTLY FOR A SHORT PERIOD OF TIME. THE CLOUDS ARE TAKING THERE TIME FILLING IN NORTH AND EAST OF THE CAPITAL REGION...SO SOME MINOR CHANGES WERE MADE TO SKYCOVER PRIOR TO 10 PM...THE INITIAL SURGE OF SNOW SHOWERS/EMBEDDED SQUALLS IS MOVING EAST OF LAKES ONTARIO...AND ERIE...AND WILL REACH THE WRN DACKS BETWEEN 8-10 PM EST WITH THE LIGHT ACCUMS. THE LATEST 3-KM HRRR CONTINUES TO SHOW THIS BAND WEAKENING AS IT MOVES EAST OF THE DACKS AROUND MIDNIGHT. SOME MINOR CHANGES WERE ALSO MADE TO THE POP TRENDS. IT WILL BE ANOTHER COLD NIGHT...BUT NOT AS COLD AS THE TEMPERATURES LATER IN THE WEEKEND. LOWS OVERNIGHT WILL RANGE FROM 10 BELOW ZERO NORTHWEST TO 15 ABOVE ZERO SOUTHEAST. WINDS WILL ALSO INCREASE OVERNIGHT ACROSS THE FA WITH A WIND CHILL WARNING STARTING AT 3 AM FOR THE SOUTHERN ADIRONDACKS...WESTERN MOHAWK VALLEY...EASTERN CATSKILLS AND SOUTHERN VERMONT. WINDS BEHIND THE FRONT WILL BE MAINLY WEST TO SOUTHWEST AT 10 TO 20 MPH WITH GUSTS TO 30 MPH. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... WIND CHILL WARNINGS IN EFFECT FOR SATURDAY-SUNDAY MORNING FOR ALL OF EASTERN NEW YORK AND ADJACENT WESTERN NEW ENGLAND. THE COLDEST AIRMASS OF THE SEASON WILL BE WITH US OVER THE WEEKEND IN THE WAKE OF THE ARCTIC FRONT AS AN ARCTIC AREA OF HIGH PRESSURE SETTLES OVER THE REGION BY SUNDAY. H8 TEMPS DROP TO 27 TO 34 DEGREES BELOW ZERO BY SATURDAY EVENING. HAVE GONE WITH A NON- DIURNAL RANGE OF TEMPS ON SATURDAY AS THE LOWS FRIDAY NIGHT AND THE HIGHS ON SATURDAY SHOULD BE THE SAME WITH THE TEMPS DROPPING ALL DAY ON SATURDAY. TEMPS ARE EXPECTED TO DROP FROM 10 BELOW TO 15 ABOVE ZERO EARLY SATURDAY MORNING TO 15 BELOW ZERO TO 5 ABOVE ZERO BY EARLY SATURDAY EVENING. WIND CHILLS ON SATURDAY WILL RANGE FROM 10 BELOW TO 35 BELOW ZERO WITH NORTHWEST WINDS 10 TO 20 MPH WITH GUSTS 30 TO 40 MPH. SATURDAY NIGHT WILL BE ESPECIALLY BRUTAL AS AIR TEMPERATURES ARE EXPECTED TO DROP TO 5 BELOW TO NEAR 30 BELOW ZERO WITH WIND CHILL VALUES 25 BELOW TO NEAR 50 BELOW ZERO. SUNDAY INTO SUNDAY NIGHT...HIGH PRESSURE WILL MOVE OVER OUR REGION ON SUNDAY AND OFF THE EASTERN SEABOARD LATE SUNDAY NIGHT. WINDS WILL STILL BE FAIRLY STRONG ON SUNDAY MORNING BEFORE SUBSIDING LATER SUNDAY INTO SUNDAY NIGHT. HIGHS ON SUNDAY WILL BE IN THE ZERO TO 15 ABOVE ZERO RANGE WITH THE LOWS SUNDAY NIGHT BETWEEN 10 BELOW AND 5 ABOVE ZERO. MONDAY WILL FEATURE INCREASING CLOUDS AS THE NEXT SYSTEM STARTS TO TRACK NORTHEASTWARD FROM THE SOUTHEAST COAST. HIGHS WILL MODERATE ON MONDAY RANGING FROM THE UPPER TEENS NORTHWEST TO UPPER 20S SOUTHEAST WITH A CHANCE OF SNOW ACROSS THE SOUTHERN HALF OF THE FA LATE IN THE DAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A SIGNIFICANT STORM IS EXPECTED TO IMPACT THE REGION DURING THE EARLY PART OF THE EXTENDED PERIOD. THERE IS INCREASING CONFIDENCE AS TO THE TRACK AND INTENSITY OF THIS SYSTEM... AT LEAST IN ITS EARLY STAGES. TWO TO SIX INCH ACCUMULATIONS ARE EXPECTED MONDAY NIGHT... WHICH IS MORE OR LESS THE START OF THE EVENT. BEYOND THAT THERE IS STILL UNCERTAINTY AS TO PRECIPITATION TYPE AS THERE IS PLENTY OF MILD AIR TO BE DRAWN IN OUT AHEAD OF THIS SYSTEM...THUS THE EXACT TRACK AND INTENSITY WILL BE CRUCIAL. RIGHT NOW...THE TRACK IS EXPECTED TO BE FROM ABOUT CHARLOTTE NORTH CAROLINA THROUGH ALBANY. BECAUSE THE TRACK IS NOT SEEN AS GOING FAR ENOUGH TO THE EAST TO GIVE US AN ALL SNOW EVENT...INDICATIONS ARE PRECIPITATION WILL LIKELY CHANGE OVER TO RAIN FOR A TIME ON TUESDAY...PARTICULARLY OUTSIDE OF THE ADIRONDACKS...BEFORE EVERYTHING TAPERS OFF AS SNOW TUESDAY NIGHT. THERE IS THE POTENTIAL FOR VERY SIGNIFICANT ACCUMULATIONS...BUT ANY DECENT PERIOD OF RAIN...AS IS EXPECTED RIGHT NOW...WILL KEEP SNOW ACCUMULATIONS AT BAY. BROAD LAKE ENHANCEMENT ON INCREASING WESTERLY WINDS BEHIND THE DEPARTING STORM WILL KEEP SNOW SHOWERS OF LIGHT AMOUNTS GOING FOR MANY AREAS TUESDAY NIGHT...WITH MIXED RAIN AND SNOW SHOWERS FOR WEDNESDAY. BUT THE ACTIVITY WILL WIND DOWN RAPIDLY ON THURSDAY AS HIGH PRESSURE SETTLES IN...BUT WITHOUT THE EXTREME COLD WE/RE EXPECTING THIS WEEKEND. HIGH TEMPERATURES ARE EXPECTED TO RANGE FROM THE MID 30S THROUGH THE UPPER 40S ON TUESDAY...THE UPPER 20S TO AROUND 40 DEGREES ON WEDNESDAY...AND THE MID TEENS TO AROUND 30 DEGREES ON THURSDAY. FRIDAY HIGHS WILL REBOUND SOMEWHAT. OVERNIGHT LOWS MONDAY NIGHT WILL RANGE FROM THE UPPER TEENS IN THE MOUNTAINS TO THE UPPER 20S IN THE LOWER MID HUDSON VALLEY. TUESDAY NIGHT...THEY WILL RANGE FROM THE MID 20S IN THE WESTERN ADIRONDACKS...TO THE LOWER 30S DOWN THE HUDSON VALLEY. WEDNESDAY NIGHT WILL TURN SHARPLY COLDER...AND THURSDAY NIGHT WILL BE COLDEST...WITH LOWS RANGING FROM THE LOW SINGLE DIGITS IN THE WESTERN ADIRONDACKS...TO THE UPPER TEENS DOWN THE MID HUDSON VALLEY. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... A CLIPPER LOW WILL PASS NORTH OF THE REGION TONIGHT...AS THE ARCTIC COLD FRONT WILL MOVE THROUGH OVERNIGHT. A NW FLOW OF ARCTIC AIR WILL IMPACT THE REGION THROUGH THE DAY INTO THE NIGHT PERIOD WITH GUSTY WINDS. THE ARCTIC FRONT WILL FOCUS SOME ISOLATED TO SCATTERED SNOW SHOWERS OR A SQUALL FROM THE CAPITAL REGION NORTH...IMPACTING KGFL/KALB/KPSF BTWN 04Z-09Z. THE SNOW SHOWERS WILL BE FAIRLY ISOLATED TO SCATTERED IN COVERAGE DUE TO VERY LIMITED LOW-LEVEL MOISTURE. A VCSH WAS USED AT KALB/KPSF AFTER 05Z...AND A TEMPO WAS USED FOR MVFR CONDITIONS AT KGFL BTWN 04Z-06Z. VFR CONDITIONS WILL BE DOMINATE...ASIDE FOR SOME MVFR CIGS/VSBYS WITH ANY SNOW SHOWERS/ISOLD SQUALLS ESPECIALLY AT KPSF/KGFL. CIGS WILL BE MAINLY IN THE 4-9 KFT AGL RANGE. IN THE WAKE OF THE FRONT LATE TOMORROW MORNING...SOME LINGERING STRATOCUMULUS OR MID LEVEL CLOUDS WILL LINGER. OVERALL...VFR CONDITIONS WILL CONTINUE IN THE FRIGID NORTHWEST FLOW THROUGH THE PM. THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 4-10 KTS PRIOR TO MIDNIGHT...THEN VEER TO THE W TO NW AT 6-12 KTS BEFORE DAYBREAK WITH SOME GUSTS TO 20-25 KTS. THE WINDS WILL INCREASE IN THE WAKE OF THE ARCTIC FRONT LATE TOMORROW MORNING INTO THE AFTERNOON AT 12-20 KTS WITH SOME GUSTS AROUND 30 KTS...ESPECIALLY AT KALB/KPSF. OUTLOOK... SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SN. SUNDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SN. WASHINGTONS BIRTHDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...SN. MONDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... WITH BITTER COLD AIR IN PLACE...ICE COVERAGE ON RIVERS AND LAKES WILL CONTINUE TO INCREASE AND STRENGTHEN OVER THE NEXT FEW DAYS. A FEW LIGHT SNOW SHOWERS ARE POSSIBLE...MAINLY THIS EVENING...BUT THIS WILL AMOUNT TO LITTLE IF ANY HYDROLOGIC SIGNIFICANCE. HOWEVER...THERE IS THE POTENTIAL FOR A HEAVY PRECIPITATION EVENT TO IMPACT THE REGION FROM MONDAY NIGHT THROUGH WEDNESDAY. THERE REMAINS CONSIDERABLE UNCERTAINTY REGARDING THE TYPES OF PRECIPITATION THAT MAY OCCUR...WHICH WILL ULTIMATELY DEPEND ON THE EXACT TRACK OF THIS POTENTIAL STORM SYSTEM. AT THIS TIME...MODEL GUIDANCE IS SUGGESTING ONE TO THREE INCHES OF LIQUID EQUIVALENT COULD OCCUR...AND MUCH OF THIS COULD BE IN THE FORM OF RAIN. IF THIS RAIN WERE TO MATERIALIZE...IT COULD HAVE A HIGH IMPACT ON RIVERS AND STREAMS...ESP CONSIDERING THE GROUND WILL BE FULLY FROZEN BY THAT TIME...ALLOWING MUCH OF THE PRECIP TO BE RUNOFF. DETAILS WILL BECOME MORE CERTAIN OVER THE NEXT FEW DAYS. 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...WIND CHILL WARNING FROM 1 PM SATURDAY TO 1 PM EST SUNDAY FOR CTZ001-013. NY...WIND CHILL WARNING FROM 3 AM SATURDAY TO 1 PM EST SUNDAY FOR NYZ032-033-038-042-047-051-058-063-082. WIND CHILL WARNING FROM 1 PM SATURDAY TO 1 PM EST SUNDAY FOR NYZ039>041-043-048>050-052>054-059>061-064>066-083-084. MA...WIND CHILL WARNING FROM 1 PM SATURDAY TO 1 PM EST SUNDAY FOR MAZ001-025. VT...WIND CHILL WARNING FROM 3 AM SATURDAY TO 1 PM EST SUNDAY FOR VTZ013>015. && $$ SYNOPSIS...IRL/WASULA NEAR TERM...11/WASULA SHORT TERM...11 LONG TERM...ELH AVIATION...WASULA HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
635 PM EST FRI FEB 12 2016 .SYNOPSIS... AN ARCTIC COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT WITH SCATTERED SNOW SHOWERS AND ISOLATED SNOW SQUALLS AHEAD OF IT. BEHIND THE ARCTIC COLD FRONT...THE COLDEST AIRMASS OF THE SEASON WILL BUILD ACROSS THE REGION FOR THE WEEKEND WITH BITTERLY COLD TEMPERATURES AND WIND CHILLS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 634 PM EST...AN ARCTIC COLD FRONT WILL BE MOVING THROUGH THE REGION LATER THIS EVENING THROUGH THE OVERNIGHT HOURS. AHEAD OF THIS FRONTAL BOUNDARY THERE WILL BE SCATTERED SNOW SHOWERS AND PERHAPS A FEW EMBEDDED SNOW SQUALLS. SNOWFALL AMOUNTS ARE EXPECTED TO BE ON THE LIGHT SIDE WITH GENERALLY A DUSTING TO 2 INCHES. ANY SNOW SQUALLS WOULD LIKELY REDUCE VISIBILITY SIGNIFICANTLY FOR A SHORT PERIOD OF TIME. THE CLOUDS ARE TAKING THERE TIME FILLING IN NORTH AND EAST OF THE CAPITAL REGION...SO SOME MINOR CHANGES WERE MADE TO SKYCOVER PRIOR TO 10 PM...THE INITIAL SURGE OF SNOW SHOWERS/EMBEDDED SQUALLS IS MOVING EAST OF LAKES ONTARIO...AND ERIE...AND WILL REACH THE WRN DACKS BETWEEN 8-10 PM EST WITH THE LIGHT ACCUMS. THE LATEST 3-KM HRRR CONTINUES TO SHOW THIS BAND WEAKENING AS IT MOVES EAST OF THE DACKS AROUND MIDNIGHT. SOME MINOR CHANGES WERE ALSO MADE TO THE POP TRENDS. IT WILL BE ANOTHER COLD NIGHT...BUT NOT AS COLD AS THE TEMPERATURES LATER IN THE WEEKEND. LOWS OVERNIGHT WILL RANGE FROM 10 BELOW ZERO NORTHWEST TO 15 ABOVE ZERO SOUTHEAST. WINDS WILL ALSO INCREASE OVERNIGHT ACROSS THE FA WITH A WIND CHILL WARNING STARTING AT 3 AM FOR THE SOUTHERN ADIRONDACKS...WESTERN MOHAWK VALLEY...EASTERN CATSKILLS AND SOUTHERN VERMONT. WINDS BEHIND THE FRONT WILL BE MAINLY WEST TO SOUTHWEST AT 10 TO 20 MPH WITH GUSTS TO 30 MPH. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... WIND CHILL WARNINGS IN EFFECT FOR SATURDAY-SUNDAY MORNING FOR ALL OF EASTERN NEW YORK AND ADJACENT WESTERN NEW ENGLAND. THE COLDEST AIRMASS OF THE SEASON WILL BE WITH US OVER THE WEEKEND IN THE WAKE OF THE ARCTIC FRONT AS AN ARCTIC AREA OF HIGH PRESSURE SETTLES OVER THE REGION BY SUNDAY. H8 TEMPS DROP TO 27 TO 34 DEGREES BELOW ZERO BY SATURDAY EVENING. HAVE GONE WITH A NON- DIURNAL RANGE OF TEMPS ON SATURDAY AS THE LOWS FRIDAY NIGHT AND THE HIGHS ON SATURDAY SHOULD BE THE SAME WITH THE TEMPS DROPPING ALL DAY ON SATURDAY. TEMPS ARE EXPECTED TO DROP FROM 10 BELOW TO 15 ABOVE ZERO EARLY SATURDAY MORNING TO 15 BELOW ZERO TO 5 ABOVE ZERO BY EARLY SATURDAY EVENING. WIND CHILLS ON SATURDAY WILL RANGE FROM 10 BELOW TO 35 BELOW ZERO WITH NORTHWEST WINDS 10 TO 20 MPH WITH GUSTS 30 TO 40 MPH. SATURDAY NIGHT WILL BE ESPECIALLY BRUTAL AS AIR TEMPERATURES ARE EXPECTED TO DROP TO 5 BELOW TO NEAR 30 BELOW ZERO WITH WIND CHILL VALUES 25 BELOW TO NEAR 50 BELOW ZERO. SUNDAY INTO SUNDAY NIGHT...HIGH PRESSURE WILL MOVE OVER OUR REGION ON SUNDAY AND OFF THE EASTERN SEABOARD LATE SUNDAY NIGHT. WINDS WILL STILL BE FAIRLY STRONG ON SUNDAY MORNING BEFORE SUBSIDING LATER SUNDAY INTO SUNDAY NIGHT. HIGHS ON SUNDAY WILL BE IN THE ZERO TO 15 ABOVE ZERO RANGE WITH THE LOWS SUNDAY NIGHT BETWEEN 10 BELOW AND 5 ABOVE ZERO. MONDAY WILL FEATURE INCREASING CLOUDS AS THE NEXT SYSTEM STARTS TO TRACK NORTHEASTWARD FROM THE SOUTHEAST COAST. HIGHS WILL MODERATE ON MONDAY RANGING FROM THE UPPER TEENS NORTHWEST TO UPPER 20S SOUTHEAST WITH A CHANCE OF SNOW ACROSS THE SOUTHERN HALF OF THE FA LATE IN THE DAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A SIGNIFICANT STORM IS EXPECTED TO IMPACT THE REGION DURING THE EARLY PART OF THE EXTENDED PERIOD. THERE IS INCREASING CONFIDENCE AS TO THE TRACK AND INTENSITY OF THIS SYSTEM... AT LEAST IN ITS EARLY STAGES. TWO TO SIX INCH ACCUMULATIONS ARE EXPECTED MONDAY NIGHT... WHICH IS MORE OR LESS THE START OF THE EVENT. BEYOND THAT THERE IS STILL UNCERTAINTY AS TO PRECIPITATION TYPE AS THERE IS PLENTY OF MILD AIR TO BE DRAWN IN OUT AHEAD OF THIS SYSTEM...THUS THE EXACT TRACK AND INTENSITY WILL BE CRUCIAL. RIGHT NOW...THE TRACK IS EXPECTED TO BE FROM ABOUT CHARLOTTE NORTH CAROLINA THROUGH ALBANY. BECAUSE THE TRACK IS NOT SEEN AS GOING FAR ENOUGH TO THE EAST TO GIVE US AN ALL SNOW EVENT...INDICATIONS ARE PRECIPITATION WILL LIKELY CHANGE OVER TO RAIN FOR A TIME ON TUESDAY...PARTICULARLY OUTSIDE OF THE ADIRONDACKS...BEFORE EVERYTHING TAPERS OFF AS SNOW TUESDAY NIGHT. THERE IS THE POTENTIAL FOR VERY SIGNIFICANT ACCUMULATIONS...BUT ANY DECENT PERIOD OF RAIN...AS IS EXPECTED RIGHT NOW...WILL KEEP SNOW ACCUMULATIONS AT BAY. BROAD LAKE ENHANCEMENT ON INCREASING WESTERLY WINDS BEHIND THE DEPARTING STORM WILL KEEP SNOW SHOWERS OF LIGHT AMOUNTS GOING FOR MANY AREAS TUESDAY NIGHT...WITH MIXED RAIN AND SNOW SHOWERS FOR WEDNESDAY. BUT THE ACTIVITY WILL WIND DOWN RAPIDLY ON THURSDAY AS HIGH PRESSURE SETTLES IN...BUT WITHOUT THE EXTREME COLD WE/RE EXPECTING THIS WEEKEND. HIGH TEMPERATURES ARE EXPECTED TO RANGE FROM THE MID 30S THROUGH THE UPPER 40S ON TUESDAY...THE UPPER 20S TO AROUND 40 DEGREES ON WEDNESDAY...AND THE MID TEENS TO AROUND 30 DEGREES ON THURSDAY. FRIDAY HIGHS WILL REBOUND SOMEWHAT. OVERNIGHT LOWS MONDAY NIGHT WILL RANGE FROM THE UPPER TEENS IN THE MOUNTAINS TO THE UPPER 20S IN THE LOWER MID HUDSON VALLEY. TUESDAY NIGHT...THEY WILL RANGE FROM THE MID 20S IN THE WESTERN ADIRONDACKS...TO THE LOWER 30S DOWN THE HUDSON VALLEY. WEDNESDAY NIGHT WILL TURN SHARPLY COLDER...AND THURSDAY NIGHT WILL BE COLDEST...WITH LOWS RANGING FROM THE LOW SINGLE DIGITS IN THE WESTERN ADIRONDACKS...TO THE UPPER TEENS DOWN THE MID HUDSON VALLEY. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... VFR FLYING CONDITIONS ARE EXPECTED TO PREVAIL THROUGHOUT THE TAF PERIOD AS AN ARCTIC COLD FRONT AND SOME SCATTERED SNOW SHOWERS MOVE ACROSS THE REGION TONIGHT. THIS AFTERNOON...WINDS WILL BE S-SW AT AROUND 5-10 KTS. SKIES WILL FEATURE BKN/OVC PASSING CIRRUS WITH SOME FEW-SCT DIURNAL CU DEVELOPING LATE THIS AFTERNOON. CLOUDS WILL EVENTUALLY INCREASE THIS EVENING AS AN ARCTIC FRONTAL BOUNDARY STARTS TO APPROACH FROM THE EASTERN GREAT LAKES. TONIGHT INTO SATURDAY...THIS FRONTAL BOUNDARY MAY ALLOW FOR A ROGUE SNOW SHOWER OR SNOW SQUALL FOR LATE TONIGHT...MAINLY AFTER MIDNIGHT AT KALB AND KPSF...BUT AS EARLY AS 03Z AT KGFL. SNOW SHOWERS WILL BE FAIRLY SCATTERED IN COVERAGE DUE TO LIMITED MOISTURE IN PLACE...SO WILL ONLY ADDRESS WITH VCSH. DID NOT INCLUDE MENTION OF VCSH AT KPOU AS ANY SNOW SHOWER ACTIVITY IS EXPECTED TO STAY PRIMARILY NORTH. OTHERWISE...IT SHOULD CONTINUE TO BE VFR TONIGHT WITH BKN-OVC CIGS AROUND 4-8 KFT...AND SW WINDS AROUND 5 KTS. WINDS WILL EVENTUALLY SWITCH TO THE WEST BEHIND THE FRONTAL BOUNDARY TOWARDS 12Z SATURDAY AND INCREASE TO 10-15 KTS. WINDS WILL BE GUSTY AT TIMES BY THE END OF THE TAF PERIOD...IN THE 20-25 KNOT RANGE ESPECIALLY AT KALB. OUTLOOK... SATURDAY THROUGH SATURDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX. SUNDAY THROUGH SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. WASHINGTONS BIRTHDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SN. MONDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SN...SLEET. TUESDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...FZRA. && .HYDROLOGY... WITH BITTER COLD AIR IN PLACE...ICE COVERAGE ON RIVERS AND LAKES WILL CONTINUE TO INCREASE AND STRENGTHEN OVER THE NEXT FEW DAYS. A FEW LIGHT SNOW SHOWERS ARE POSSIBLE...MAINLY THIS EVENING...BUT THIS WILL AMOUNT TO LITTLE IF ANY HYDROLOGIC SIGNIFICANCE. HOWEVER...THERE IS THE POTENTIAL FOR A HEAVY PRECIPITATION EVENT TO IMPACT THE REGION FROM MONDAY NIGHT THROUGH WEDNESDAY. THERE REMAINS CONSIDERABLE UNCERTAINTY REGARDING THE TYPES OF PRECIPITATION THAT MAY OCCUR...WHICH WILL ULTIMATELY DEPEND ON THE EXACT TRACK OF THIS POTENTIAL STORM SYSTEM. AT THIS TIME...MODEL GUIDANCE IS SUGGESTING ONE TO THREE INCHES OF LIQUID EQUIVALENT COULD OCCUR...AND MUCH OF THIS COULD BE IN THE FORM OF RAIN. IF THIS RAIN WERE TO MATERIALIZE...IT COULD HAVE A HIGH IMPACT ON RIVERS AND STREAMS...ESP CONSIDERING THE GROUND WILL BE FULLY FROZEN BY THAT TIME...ALLOWING MUCH OF THE PRECIP TO BE RUNOFF. DETAILS WILL BECOME MORE CERTAIN OVER THE NEXT FEW DAYS. 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...WIND CHILL WARNING FROM 1 PM SATURDAY TO 1 PM EST SUNDAY FOR CTZ001-013. NY...WIND CHILL WARNING FROM 3 AM SATURDAY TO 1 PM EST SUNDAY FOR NYZ032-033-038-042-047-051-058-063-082. WIND CHILL WARNING FROM 1 PM SATURDAY TO 1 PM EST SUNDAY FOR NYZ039>041-043-048>050-052>054-059>061-064>066-083-084. MA...WIND CHILL WARNING FROM 1 PM SATURDAY TO 1 PM EST SUNDAY FOR MAZ001-025. VT...WIND CHILL WARNING FROM 3 AM SATURDAY TO 1 PM EST SUNDAY FOR VTZ013>015. && $$ SYNOPSIS...IRL/WASULA NEAR TERM...11/WASULA SHORT TERM...11 LONG TERM...ELH AVIATION...IRL HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
931 PM EST FRI FEB 12 2016 .SYNOPSIS... AN ARCTIC FRONT WILL CROSS THE AREA TONIGHT. HIGH PRESSURE WILL BUILD ACROSS THE AREA LATER THIS WEEKEND AND THEN MOVE EAST SUNDAY NIGHT. LOW PRESSURE WILL DEEPEN ACROSS THE LOWER MISSISSIPPI VALLEY MONDAY AND THEN MOVE ALONG THE APPALACHIANS TUESDAY AND THEN NORTH INTO CANADA WEDNESDAY. MORE HIGH PRESSURE WILL BUILD IN FOR THE END OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... ONE BAND OF SNOW SHOWERS IS EXITING OFF THE NJ CST. ANOTHER IS MOVG THRU ERN PA ATTM. THE HRRR INDICATES THIS AREA WILL DISSIPATE AS IT MOVES EWD. HOWEVER, THE HRRR DID NOT DO WELL WITH THE EARLIER BAND SO CONFIDENCE IS LOW. WILL KEEP HIGH POPS W AND LWR POPS FOR THE NEXT FEW HOURS FOR THIS BAND. A STRONG CDFNT WILL CROSS THE REGION LATE TONIGHT THEN A WIND SHIFT TO NORTHWEST AND GUSTY 20-30 MPH BY DAWN SATURDAY....POSSIBLE ISOLATED GUSTS 40-45 MPH AT SUNRISE PER ARRIVING STRONG CAA AND PRES RISES. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... WIND CHILL ADVY AND WIND ADVY POSTED IN ADDITION TO PRIOR WIND CHILL WARNING. SPS FROM YDY NO LONGER NEEDED. DEEPENING BOUNDARY LAYER MOMENTUM TRANSFER IS FEATURED ASSOCIATED WITH THE ONCOMING ARCTIC AIRMASS INVASION. LARGE LOW LVL LAPSE RATES AND BTV SNOW SQUALL PARAMETER INDICATING A POSSIBILITY OF FLURRIES OR SQUALLS BUT WILL THE SFC TT/TD SPREAD EXCEED 25F AND MAKE THOSE SQUALLS JUST VIRGA? SEEMS LIKE BEST CHC FOR A SQUALL WOULD BE THE MORNING AND IN THE REGION S OF THE PA TURNPIKE. AM THINKING OF GUSTS 50 MPH IN THE POCONOS AND ALSO SCATTERED 50 MPH GUSTS DEVELOPING IN THE KRDG-KPHL-KILG KACY AND NORTH SIDE OF DE BAY SLOT FOR THE AFTN. WIND ADVY ISSUED. NOT SURE HOW MANY NOTICED BUT THE NAM AND OP ECMWF HAVE BEEN A LITTLE CONSERVATIVE ON WIND. JUST LOOKS LIKE TOO DEEP A MIXED LAYER TO AVOID CONNECTING A FEW EDDIES OF 50 KT GUSTS DOWN FROM 6000 TO 7000 FT ALOFT. THE INVERSION SINKS TO NEAR 850 MB LATE IN THE DAY SATURDAY. STRONGEST WINDS ASIDE FROM THE INITIAL BURST NEAR 11-12Z, MAY BE LATE AFTN AND EVENING. FOR NOW WANTED TO LIMIT ADVY ONLY TO THE DAY AND IF ITS GUSTING 40 KT AT 3 PM SATURDAY, THEN SUSPECT IT CAN GUST 40-45 KT THROUGH 10 PM. CONFIDENCE ON VERIFICATION IS AVERAGE. THIS COULD BE OVERDONE BUT HAVE SEEN REPEATEDLY THE POCS WIND MATCH THE OVERWATER WIND NEAR 44065, AND NW FLOW STRONGEST GUSTS NEAR A RDG-PHL LINE. ALSO ADDED MD E SHORE ALONG THE STILL WARM CHES BAY AND DELAWARE ALONG THE BAY FROM WILMINGTON TO LEWES WHERE I THINK SOME HEFTY GUSTS COULD ADD TO THE CHILL. OTHERWISE WIDESPREAD GUSTS 40 MPH SATURDAY WITH PARTLY TO MOSTLY SUNNY SKIES .. TENDING TO CLEAR LATE DAY. WINDS WERE DERIVED FROM THE GFS, THE TEMPS FROM THE NAM MOS BLENDED WITH THE 2M TEMPS OF THE 12Z GFS/NAM. HRRX INDICATED NEAR 0 AT KMPO AT 17Z SATURDAY...WITHOUT A WIND CHILL. CANT SEE IT MORE THAN 17F AT PHL AT 18Z SAT...MAYBE EVEN A DEGREE OR 2 COLDER?. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... THE HEART OF THE ARCTIC AIR MASS WILL BE ACROSS THE AREA SATURDAY NIGHT AND INTO SUNDAY. DANGEROUSLY COLD TEMPERATURES AND WIND CHILL READINGS WILL BE ACROSS THE ENTIRE FORECAST AREA. NO PRECIPITATION IS EXPECTED. WINDS WILL DIMINISH THROUGH THE DAY SUNDAY. LOW TEMPERATURES SAT NIGHT AROUND -10 ACROSS THE FAR NORTH AND CLOSER TO 5 DEGREES ACROSS THE METRO PHILLY AREAS AND OVER THE DELMARVA. HIGH TEMPS SUNDAY IN THE TEENS MOST AREAS...BUT SINGLE DIGITS OVER THE SRN POCONOS. WIND CHILL READINGS -20 TO -32 FAR NORTH AND -5 TO -10 OVER THE DELMARVA. THE NEXT STORM SYSTEM WILL DEEPEN ACROSS THE SOUTH MONDAY AND MOVE UP THE INLAND EAST COAST TUESDAY/WEDNESDAY. THE TRACK OF THE SYSTEM THAT SEEMS TO BE COMING INTO BETTER AGREEMENT AMONGST THE OP MODELS FAVOR A LOW TRACK ACROSS THE CENTRAL/WESTERN PART OF OUR AREA. THIS WILL ALLOW A DECENT FLOW OF WARMER AIR TO OVERSPREAD THE REGION. THE PRECIPITATION WILL BEGIN ACROSS THE AREA MONDAY AS SNOW...BUT WILL CHANGE TO RAIN LATER MON NIGHT AND REMAIN MOSTLY RAIN TUESDAY. THE QPF COULD BE UP TO 2 INCHES OF RAIN IN MANY AREAS. THERE IS ALSO SOME CHC FOR AN ACCUMULATING SNOW MONDAY ACROSS (MOST LIKELY) ERN/NERN PA BEFORE THE CHANGE TO RAIN. EARLIEST PREDICTIONS FOR SNOW ACCUMS WOULD BE AROUND 1-3 INCHES AT THIS POINT. THE DETAILS WILL BE TUNED UP AS THE WEEKEND PROGRESSES. THE STORM MOVES UP INTO CANADA WEDNESDAY AND WILL BE FOLLOWED BY HIGH PRESSURE AND DRIER COOLER AIR FOR THE MIDDLE OF NEXT WEEK. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDS WILL CONTINUE. HOWEVER, BASED ON LATEST RADAR SHOWING SOME ENHANCED ECHOES, HAVE MOVED UP THE TIMING OF THE SHSN. MUCH OF ACTIVITY IS NOT REACHING THE GROUND, BUT AS CLOSE AS KPNE IS REPORTING SOME -SN. SO FAR THE SHSN HAS BEEN LIGHT ENOUGH TO BE VFR. HOWEVER, SOME MVFR CAN NOT BE RULED OUT, AND WILL CONTINUE TO INCLUDE IN THE FCSTS. SATURDAY...THE BIGGEST ISSUE AFFECTING AVIATION TRAVEL ON SATURDAY WILL BE THE WINDS. BEHIND THE AFOREMENTIONED COLD FRONT, THE WINDS WILL QUICKLY TURN TO THE WEST THEN NORTHWEST AND BECOME VERY GUSTY. SUSTAINED WINDS WILL BE AROUND 15-20 KNOTS BY 12-15Z AND INCREASE INTO THE AFTERNOON. WIND GUSTS FROM 25 KNOTS EARLY WILL INCREASE TO NEAR 40 KNOTS BY THE AFTERNOON. OUTLOOK... SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED. NORTHWEST WINDS 10 TO 25 KNOTS WITH GUSTS 30-35 KNOTS EARLY, DIMINISHING SOME OVERNIGHT INTO SUNDAY. GUSTS STILL 20-25 KNOTS OVERNIGHT INTO EARLY SUNDAY. MONDAY-MONDAY NIGHT...DEGRADING CONDITIONS WITH MVFR/IFR LIKELY THROUGH THE DAY MONDAY INTO MONDAY NIGHT. SNOW POSSIBLY BEGINNING MONDAY FOR MANY AREAS, POSSIBLY MIXING WITH RAIN AT TIMES FOR SOME AREAS. TUESDAY-TUESDAY NIGHT...WIDESPREAD MVFR/IFR CONDITIONS. WINDY. WEDNESDAY...IMPROVING CONDITIONS. WINDY. && .MARINE... LULL IN THE WIND AND SEAS WILL END SHORTLY AFTER MIDNIGHT. GALES AND FREEZING SPRAY WARNINGS-ADVISORIES POSTED. THE HEAVIEST FREEZING SPRAY WILL BE MIDNIGHT TO 7 AM ALONG THE SHORE WHERE SSTS NOW DOWN TO ABOUT 35-36F AND USED 35 FOR THE ZY THRESHOLD. ISOLATED 50 KT GUSTS POSSIBLE SATURDAY IN FUNNELED NW WIND DOWN DE BAY. OUTLOOK... SATURDAY-SATURDAY NIGHT...GALE WARNING CONTINUES WITH STRONG NORTHWEST FLOW ACROSS THE AREA. FREEZING SPRAY ADVISORY REMAINS IN EFFECT AS VERY COLD AIR AND STRONG WINDS WILL LEAD TO AT LEAST MODERATE FREEZING SPRAY. SUNDAY-SUNDAY NIGHT...GALE WARNING AND FREEZING SPRAY ADVISORY CONTINUE INTO SUNDAY MORNING. HOWEVER, WINDS WILL DIMINISH THROUGH THE DAY AND SUNDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE AREA. MONDAY...SUB-SCA CONDITIONS. MONDAY NIGHT-WEDNESDAY...SMALL CRAFT ADVISORY CONDITIONS LIKELY...GALES POSSIBLE AS STRONG LOW PRESSURE MOVES UP THE EAST COAST. && .HYDROLOGY... BEFORE EVERYONE HEADS INTO THE WEEKEND, I WANTED TO BRING NEXT WEEK`S STORM INTO LIGHT AND MENTION THAT THERE IS A POTENTIAL FOR FLOODING ACROSS THE HSA. THERE`S STILL A LOT THAT NEEDS TO UNFOLD, BUT THE 5-DAY WPC QPF OF 1.50 TO 2.50 INCHES OF LIQUID COMBINED WITH ANOTHER 0.25 TO 0.50 INCH OF SWE ON THE GROUND WOULD VERY LIKELY CAUSE NUISANCE LOW-LYING FLOODING AND POSSIBLY SOME MINOR TO MODERATE RIVER FLOODING (RIVERS ASSOCIATED WITH OUR FORECAST POINTS). THIS ASSUMES MOST, IF NOT ALL, THE PRECIPITATION FALLS AS RAIN. THE UNCERTAINTY THIS AFTERNOON IS LARGE. YESTERDAY AT THIS TIME, THE PRECIPITATION WAS HEAVIEST TUESDAY AND TUESDAY NIGHT. NOW IT`S LATE MONDAY NIGHT INTO TUESDAY. BESIDES TIMING, TRACK IS QUITE DIFFERENT BETWEEN THE GFS AND EURO WITH THE EURO BEING FURTHER WEST AND MORE LIQUIDY. TRACK WILL PLAY A ROLE IN TEMPS AND NOT ONLY AFFECT WHAT TYPE OF PRECIPITATION FALLS, BUT ALSO AFFECT WHAT REMAINING SWE MELTS. THERE`S ABOUT 0.25 TO 0.50 SCATTERED ACROSS THE AREA. I CAN SAY WE ARE IN A BETTER SPOT THAN ON THE 3RD AND 4TH WHEN THERE WAS IN EXCESS OF 2.00 OF SWE ALONG THE I-78 CORRIDOR. AS AN FYI, ONE OF THE MAIN REASONS WE DIDN`T SEE THE FLOODING, THAT MODELS SUGGESTED, ON THE 3RD AND 4TH WAS BECAUSE ALL THE SWE DID NOT RAPIDLY COME OUT OF THE SNOWPACK. SNOWMELT CAN BE A TOUGH NUT TO CRACK. WHILE THE LACK OF SWE IS LOOKING BETTER ACROSS THE HSA, NOT ALL THE RIVERS HAVE RECEDED BACK TO WHERE THEY WERE PRIOR TO THE 3RD. SO RIVERS WILL START HIGHER AND THE COLD THIS WEEKEND WILL SURELY GET THE GROUND HARD FOR A VERY EFFICIENT RUNOFF. SO THE TAKE AWAY HEADING INTO THE WEEKEND IS TO UNDERSTAND THAT IF THE MONDAY INTO TUESDAY (OR TUESDAY INTO WEDNESDAY) EVENT IS ALL LIQUID ACROSS THE AREA, LOW-LYING, POOR DRAINAGE FLOODING IS LIKELY AND MINOR TO MODERATE RIVER FLOODING IS POSSIBLE. IF THE PRECIPITATION STARTS OFF AS SNOW OR ICE, THE FLOODING THREAT DECREASES. IF ALL SNOW FALLS, WE`RE POTENTIALLY JUST KICKING THE CAN DOWN THE ROAD FOR FUTURE FLOODING. TIME WILL TELL. && .CLIMATE... NEAR RECORD COLD IS STILL EXPECTED FOR PORTIONS OF OUR AREA SUNDAY MORNING, DESPITE THE MOS GUIDANCE...AND BY FAR THE COLDEST AIR OF THE SEASON SO FAR. BEST CHANCE FOR RECORD EQUALING OR EXCEEDING FOR VALENTINES DAY: KABE, KTTN, KPHL AND KMPO. RECORD LOW MAX`S CAN ONLY OCCUR FOR THIS EVENT ON SUNDAY THE 14TH, IF THEN. THOSE HAVE BEEN ADDED RECENTLY BELOW. SITE 2015-16 COLDEST SO FAR RECORD LOW FEB. 14TH ----RER LOW MAX ---------------------- -------------------- ABE 8 -1 IN 1979 14-1979 ACY 10 -6 IN 1979 13-1979 PHL 12 +2 IN 1979 14-1979 ILG 12 -4 IN 1979 13-1979 RDG 10 -4 IN 1983 TTN 9 0 IN 1916 GED 13 -7 IN 1979 MPO -1 -12 IN 1970 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WIND CHILL ADVISORY FROM 6 PM SATURDAY TO 9 AM EST SUNDAY FOR PAZ060>062-070-071-101>106. WIND ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR PAZ054-055- 060-061-070-071-101>106. WIND CHILL WARNING FROM 6 AM SATURDAY TO 1 PM EST SUNDAY FOR PAZ054-055. NJ...WIND CHILL ADVISORY FROM 6 PM SATURDAY TO 9 AM EST SUNDAY FOR NJZ007>010-012>027. WIND ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR NJZ001-014- 016>027. WIND CHILL WARNING FROM 6 AM SATURDAY TO 1 PM EST SUNDAY FOR NJZ001. DE...WIND CHILL ADVISORY FROM 6 PM SATURDAY TO 9 AM EST SUNDAY FOR DEZ001-002. WIND ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR DEZ001>004. MD...WIND CHILL ADVISORY FROM 6 PM SATURDAY TO 9 AM EST SUNDAY FOR MDZ008-012. WIND ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR MDZ008-012- 015-020. MARINE...HEAVY FREEZING SPRAY WARNING FROM MIDNIGHT SATURDAY NIGHT TO 9 AM EST SUNDAY FOR ANZ450>453. GALE WARNING FROM 4 AM SATURDAY TO 10 AM EST SUNDAY FOR ANZ430- 431-450>455. FREEZING SPRAY ADVISORY FROM 4 AM SATURDAY TO 10 AM EST SUNDAY FOR ANZ430-431-454-455. && $$ SYNOPSIS...O`HARA NEAR TERM...DRAG/NIERENBERG SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG/NIERENBERG/O`HARA MARINE...DRAG/O`HARA HYDROLOGY... CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
955 AM EST THU FEB 11 2016 .SYNOPSIS... HIGH PRESSURE WILL BUILD EASTWARD INTO THE REGION TODAY AND THEN MOVE THROUGH THE REGION TONIGHT. AN ARCTIC COLD FRONTAL BOUNDARY WILL THEN MOVE THROUGH THE AREA FRIDAY NIGHT. BY SUNDAY, ANOTHER AREA OF HIGH PRESSURE WILL BUILD SOUTHWARD INTO THE REGION AS LOW PRESSURE FORMS ACROSS THE SOUTHERN UNITED STATES BY MONDAY. THIS AREA OF LOW PRESSURE WILL THEN TRACK UP THE EAST COAST TUESDAY INTO WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... 954 AM: MAY START HAMMERING I-80 AREA IN AN 11AM UPDATE...PENDING A LITTLE MORE MODEL GUIDANCE. HRRR TRYING TO LATCH ONTO SNOW SHOWERS IN MOST RECENT CYCLE...STILL WAY BEHIND REALITY. 930 AM ESTF: WE THINK 1 TO 2 INCHES POSSIBLE IN NARROW BANDS. ALREADY UNCONFIRMED REPORT 1.5". HANDLING WITH SPS`S AND VIGOROUSLY UPDATED LEGACY AND POINT CLICK PRODUCTS. SNOW MAP UPDATING NOW BUT STILL GENERAL LESS THAN 1". 730 AM ESTF: UPDATED FOR THE SNOW BAND IN SE PA INTO SW NJ. ITS PUTTING DOWN A DUSTING THAT IS CAUSING SOME TRAVEL DIFFICULTY. A NOWCAST IS POSTED AS WELL UPDATED SNOWMAP AND FORECASTS FOR THIS MORNING. NO MODEL HAS THIS..N PART ..IN PART LES BAND TRAILING INTO OUR AREA. IF WE SEE VSBY 1 MI OR LESS WE WILL UPGRADE TO AN SPS. OUR RADAR CONTINUES IN VCP31 TO BETTER SEE THE FINER DETAILS, PLUS ITS LOW TOP AND VERY LOW WATER CONTENT. FROM THE MID SHIFT BELOW... FOR A RELATIVELY QUIET WEATHER DAY, STILL HAVE THREE MAIN STORIES TO TALK ABOUT FOR THE TODAY PERIOD. SNOW...AS MENTIONED BY THE PREVIOUS SHIFT, LOW TO MID LEVEL LAPSE RATES WILL BE QUITE STEEP ACROSS THE POCONOS AND NORTHERN NJ THROUGH AT LEAST MID DAY. IN ADDITION, THE MID AND UPPER LEVEL SHORT WAVE TROUGH WILL BE CROSSING THE REGION THROUGH THIS TIME. THESE FACTORS ARE CONDUCIVE FOR SCATTERED SNOW SHOWERS, OR MAYBE EVEN A FAST MOVING SNOW SQUALL, ACROSS THE NORTHERN HALF OF OUR REGION. WITH PERSISTENT DRY AIR ADVECTION, MOISTURE IS LIMITED. SO EVEN THOUGH SNOW/LIQUID RATIOS COULD BE ABOVE NORMAL THANKS TO THE VERY COLD AIR IN PLACE, STILL EXPECT SNOW ACCUMULATIONS TO REMAIN BELOW ONE INCH. WINDS...A TIGHT PRESSURE GRADIENT WILL REMAIN OVER THE REGION THROUGH AT LEAST 18Z BEFORE IT STARTS TO DECREASE AS THE SURFACE LOW LIFTS FURTHER AWAY FROM OUR REGION. THUS, EXPECT WINDY CONDITIONS THROUGH THE DAY. AT THIS POINT THOUGH, WIND ADVISORY CONDITIONS (SUSTAINED WINDS OF AT LEAST 31 MPH FOR AT LEAST ONE HOUR OR GUSTS OF 46 MPH) ARE NOT ANTICIPATED, SINCE THE TIGHTEST PRESSURE GRADIENT WILL BE EARLY IN THE DAY BEFORE THE MIXING LAYER GETS VERY DEEP. HAVING SAID THAT THOUGH, THE GFS DOES SHOW THAT THE SUSTAINED CRITERIA COULD BE REACHED FOR LOCATIONS ADJACENT TO THE DE BAY, SINCE THE DIRECTION IS A FAVORED DIRECTION FOR THE FUNNELING EFFECT OVER THE BAY. IN ADDITION, VAD WIND PROFILES SHOW THAT 40 KT WINDS ARE ABOUT 4000 TO 5000 FT MSL. IF THE MIXING LAYER GETS DEEP ENOUGH, SOME OF THAT COULD MIX DOWN FOR THE HIGHEST TERRAIN IN THE POCONOS AND NW NJ. FOR NOW THOUGH, CONFIDENCE IS LOW THAT IT WILL BE REACHED SO WILL NOT ISSUE AN ADVISORY AT THIS TIME. COLD...TODAY BEGINS THE COLD STRETCH WHICH WE ARE EXPECTING TO CONTINUE INTO THE WEEKEND. WHILE TODAY WILL PROBABLY BE THE WARMEST OF THE NEXT 4 DAYS, THE REGION SHOULD STAY BELOW FREEZING, AND PORTIONS OF THE POCONOS AND NW NJ MAY NOT GET OUT OF THE TEENS. THIS WILL BE 15 TO 20 DEGREES BELOW NORMAL. GIVEN THE WINDY CONDITIONS, WIND CHILL VALUES ACROSS THE REGION WILL ONLY TOP OUT IN THE TEENS AT BEST. TONIGHT...HIGH BEGINS TO BUILD IN, AND CONSEQUENTLY WINDS DIMINISH, AND CLOUDS WILL DISSIPATE. AS A RESULT, SHOULD SEE CONSIDERABLE RADIATIONAL COOLING, WITH LOWS IN THE SINGLE DIGITS AND TEENS AND WIND CHILL VALUES IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... RIGHT NOW SIMILAR TO THE PRIOR FORECAST THROUGH ANTICIPATE BEEFING UP POPS LATE FRI DAY AFTERNOON IN THE POCONOS. NO CHANGES ATTM FOR FRI NIGHT. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... OUR UPDATED BRIEFING PACKAGE AT MIDDAY WILL INCLUDE MORE INFORMATION ON THE UPCOMING DANGEROUS COLD, INCLUDING A POSSIBLE WIND CHILL WATCH FOR SAT NIGHT WHICH IS ALREADY A HIGH CONFIDENCE LIKELIHOOD. THE EXTENDED WILL FEATURE BOTH THE PROSPECTS FOR THE COLDEST AIR OF THE SEASON CENTERED ON SUNDAY MORNING AND A STRENGTHENING LOW PRESSURE SYSTEM TRACKING UP THE EAST COAST EARLY NEXT WEEK. FRIDAY AND SATURDAY: HIGH PRESSURE WILL MOVE THROUGH THE REGION ON FRIDAY. THIS HIGH PRESSURE SYSTEM WILL GIVE WAY TO ANOTHER ARCTIC COLD FRONT FRIDAY NIGHT. THE COLD FRONT SHOULD PROVIDE ENOUGH LIFT AND MOISTURE FOR SOME SCATTERED SNOW SHOWERS TO DEVELOP. THESE MAY PRODUCE SOME LIGHT ACCUMULATIONS OF UNDER AN INCH. BEHIND THE FRONT, IT WILL BE A VERY COLD AND WINDY PERIOD WITH SOME ADDITIONAL SNOW SHOWERS AND/OR FLURRIES IN ASSOCIATION WITH THE NW FLOW OFF OF THE EASTERN GREAT LAKES. THE FAVORED REGIONS TO SEE SNOW SHOWERS ARE IN THE HIGH TERRAIN AREAS OF EASTERN PA AND NW NJ. BUFKIT ANALYSIS YIELDS THE POTENTIAL FOR 30-40 MPH GUSTS SATURDAY AFTERNOON ACROSS THE REGION WITH THE GFS BEING THE MOST AGGRESSIVE WITH THE GUST POTENTIAL. THE STRONG CAA WILL NOT ALLOW TEMPERATURES TO RISE MUCH DURING THE DAY. SATURDAY NIGHT THROUGH SUNDAY NIGHT: ANOTHER POTENT AREA OF ARCTIC HIGH PRESSURE WILL BUILD INTO THE REGION WITH THE COLDEST SHOT OF AIR OF THE SEASON SO FAR. MODELING HAS BEEN HOLDING STEADY ON THE IDEA THAT 850 MB TEMPERATURES LOOK TO DIVE BELOW -25C. WILL NUDGE TEMPERATURES A COUPLE OF DEGREES COOLER THAN MOST ENSEMBLE GUIDANCE THROUGH THE WEEKEND DUE TO THE DEGREE OF THE COLD AIR BEING MODELED. STRONG NORTHWEST WIND GUSTS, THOUGH NOT AS STRONG AS ON SATURDAY WILL CONTINUE IN THE WAKE OF THE DEPARTING SYSTEM. THE COLD AND WIND WILL RESULT IN WIND CHILLS FROM -10 TO -30 BELOW ZERO SATURDAY NIGHT AND SUNDAY MORNING. PLEASE TO MAKE SURE TO PREPARE FOR THE COLD WEATHER THAT IS COMING. PREPARATIONS INCLUDE CHECKING PIPES AND MAKING SURE YOUR VEHICLE IS IN GOOD WORKING CONDITION. LOW TEMPERATURES SUNDAY MORNING WILL LIKELY NEAR OR BELOW ZERO AS WELL. PLEASE REFER TO THE CLIMATE SECTION ON RECORD POTENTIAL. PRESIDENTS DAY THROUGH TUESDAY NIGHT: HIGH PRESSURE WILL GRADUALLY MOVE EAST OF THE REGION AND WILL GIVE WAY TO A STORM SYSTEM THAT IS CURRENTLY MODELED TO FORM ACROSS THE SOUTHERN UNITED STATES AND INTENSIFY AS IT MOVES UP THE EAST COAST. THE 00Z 2/11 OPERATIONAL MODELS HAVE NARROWED THE GOAL POSTS OF POSSIBLE TRACKS FROM EARLIER MODEL RUNS. THIS ALSO MATCHES OR IS JUST EAST OF THE 12Z 2/10 ECMWF ENSEMBLE MEAN TRACK. THIS TRACK GOES FROM SOUTH CENTRAL AL/GA NORTHEAST TO THE CAROLINA COASTLINE THEN DUE NORTH UP THE EAST COAST INTO SOUTHERN NEW ENGLAND. TWO MAIN FEATURES ARE PRESENT TO TRACK WITH REGARDS TO MODELS OR RESPECTIVE ENSEMBLES CHANGING THE FORECAST TRACK OF THIS SYSTEM IN FUTURE RUNS. THIS FIRST IS A LEADING SHORTWAVE WHICH MOVES INTO THE THE OHIO VALLEY ON MONDAY AND THE SECOND IS THE DEGREE OF MID- LEVEL HEIGHT RISES THAT OCCUR AHEAD OF THE STORM SYSTEM. A STRONGER SHORTWAVE WOULD TEND TO PUSH THE OVERALL TROUGH WITH THIS STORM FURTHER EAST. WHILE A WEAKER SHORTWAVE WOULD ALLOW FOR HIGHER MID- LEVEL HEIGHT RISES LEADING TO A FURTHER WEST TRACK OF THE LOW. RIGHT NOW THE FAVORED TRACK WOULD RESULT IN SNOW CHANGING TO RAIN ACROSS MOST OF THE REGION WITH THE HIGHEST CHANCES FOR PRECIPITATION MONDAY NIGHT AND TUESDAY. IT WILL LIKELY BE WINDY AS WELL WITH THE STRENGTHENING LOW PRESSURE SYSTEM TRACKING NEAR THE REGION. WEDNESDAY: THE REGION SHOULD GRADUALLY BEGIN TO CLEAR OUT AS ANOTHER HIGH PRESSURE SYSTEM BUILDS EASTWARD TOWARD THE REGION. SOME UNCERTAINTY THOUGH AS 2/11 00Z ECMWF BRINGS ANOTHER SYSTEM INTO THE REGION BY THIS PERIOD. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...VFR SCT-BKN AOA 4000 FT. BRIEF IFR CONDS IN SNOW SHOWERS VCNTY KPHL NORTH THROUGH KTTN, KABE, AND KRDG. TIMING UNCERTAIN AND HANDLING AS NEAR TERM FCST. THESE MESOSCALE BANDS DONT APPEAR TO BE WELL HANDLED BY OUR HRRR HRRRX PRODUCTS NOR RUC/RAP. NEW 12Z/11 NAM HAS A NEW BAND DEVELOPING NEAR AND N OF I-80 THIS AFTN. LATEST HRRR TRYING TO GRASP THE SITN. CERTAINLY VERY LARGE LOW LVL LAPSE RATES AS COLD POOL ALOFT TEMPORARILY LIFTS ENE. BASICALLY THERE APPEARS TO BE A LAKE EFFECT SNOW - MOISTURE PLUME CONNECTION TO THE STILL WIDE OPEN LERIE, THEN SEWD INTO SWRN PA AND FROM THERE EWD TO NEAR PHL. THAT MAY REFOCUS NEAR I-80 OR I-78 THIS AFTN. WEST WIND GUSTS INCREASING TO 30 KT BY 16Z. ISOLATED 35 KT POSSIBLE. TONIGHT...VFR SCT-BKN CLOUDS AOA 4000 FT DURING THE EVENING BECOMING CLEAR. GUSTY WNW WINDS 20-30 KT SLOWLY DIMINISHING DURING THE NIGHT. FRIDAY...VFR. OUTLOOK... FRIDAY NIGHT AND SATURDAY: MAINLY VFR, POSSIBLE MVFR RESTRICTIONS IN SCATTERED SNOW SHOWERS. NORTHWEST WINDS INCREASING SATURDAY FROM 15-25 KNOTS WITH GUSTS UP TO 40 KNOTS SATURDAY AFTERNOON. SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED. NORTHWEST WINDS 10 TO 25 KNOTS. MONDAY...VFR CONDITIONS FOR MOST OF THE DAY THEN BECOMING MVFR AND IFR BY EVENING WITH RAIN AND SNOW. && .MARINE... GALES IN PROGRESS AND GLW CONTINUES AS POSTED. AN SCA WILL BE NEEDED FOR MUCH IF NOT ALL OF THE OVER NIGHT HOURS ONCE THE GALES SUBSIDE. LIGHT FREEZING SPRAY IS OCCURRING AND CONTINUES TO BE EXPECTED ON THE BAY AS WELL AS THE NEAR COASTAL WATERS. OUTLOOK... OUR AFTERNOON MARINE PRODUCTS WILL HEADLINE A NEW HIGH CONFIDENCE GALE WATCH FOR THE PERIOD ROUGHLY 4 AM SATURDAY THROUGH 8 AM SUNDAY. SO WHILE, SEAS AND WINDS WILL START OUT FAIRLY LIGHT ON FRIDAY. HOWEVER, A QUICK RAMP UP IS EXPECTED AFTER THE PASSAGE OF AN ARCTIC COLD FRONTAL BOUNDARY FRIDAY NIGHT. NORTHWEST WINDS WILL INCREASE AND REACH GALE FORCE BY SATURDAY AND CONTINUE GALE FORCE THROUGH SATURDAY NIGHT. CONFIDENCE FOR GALES ON SATURDAY IS VERY HIGH. SEAS WILL RISE TO BETWEEN 5 AND 7 FEET FOR A PERIOD AS WELL ON SATURDAY. SEAS AND WINDS ARE EXPECTED TO DECREASE ON SUNDAY. WAVE HEIGHTS WILL LIKELY START INCREASING AGAIN BY MONDAY NIGHT IN RESPONSE TO A DEVELOPING LOW PRESSURE SYSTEM TO OUR SOUTH. && .CLIMATE... NEAR RECORD COLD IS EXPECTED FOR PORTIONS OF OUR AREA SUNDAY MORNING AND BY FAR THE COLDEST AIR OF THE SEASON SO FAR. ANTICIPATING TEMPS THROUGHOUT OUR FORECAST AREA WITHIN SEVERAL DEGREES OF ZERO (WIND IS THE EQUALIZER) ANYTIME FROM MIDNIGHT THROUGH 8 AM SUNDAY EXCEPT COLDER KMPO (NEAR -12F). THIS HAS BEEN ADVERTISED BY THE GFS/ECMWF 2M TEMPS CYCLICALLY SINCE AT LEAST THE 00Z/7 OPERATIONAL CYCLES. THEREFORE, BEST CHANCE FOR RECORD EQUALING OR EXCEEDING FOR VALENTINES DAY THE 14TH WOULD BE KABE, KTTN, KPHL AND KMPO. SNOW COVER MAY HELP A BIT I-95 NORTHWESTWARD...AND WE`LL SEE WHERE WE ARE WITH SNOW COVER BY THURSDAY EVENING. NEW DUSTINGS APPEAR ON THE WAY THROUGH FRIDAY NIGHT. PLEASE NOTE... GUIDANCE IN PART IS BEING CLIMO BIASED HIGHER THAN WHAT THE ONCOMING GFS/ECMWF LITERAL AIRMASS AND 2M TEMPS ARE INDICATING FOR SUNDAY MORNING. TEMPS SUNDAY MORNING IN THE URBAN AREAS SHOULD BE ABOUT 25 COLDER THAN NORMAL. THAT MEANS GUIDANCE TEMPS FOR PHL OF 5 AND 6 DEGREES APPEAR TOO WARM...ESPECIALLY WITH A NORMAL PHILADELPHIA LOW ON SUNDAY OF 28. HAVE SEEN THE 12Z/11 2M TEMPS FOR PHL...1 ABOVE RANGING DOWN TO -11 AT KMPO AND AM LIKING THOSE VALUES AS WITHIN 2F OF THE UPCOMING REALITY. RECORD LOW MAX`S CAN ONLY OCCUR FOR THIS EVENT ON SUNDAY THE 14TH, IF THEN. THOSE HAVE BEEN ADDED RECENTLY BELOW. SITE 2015-16 COLDEST SO FAR RECORD LOW FEB. 14TH ----RER LOW MAX ---------------------- -------------------- ABE 8 -1 IN 1979 14-1979 ACY 10 -6 IN 1979 13-1979 PHL 12 +2 IN 1979 14-1979 ILG 12 -4 IN 1979 13-1979 RDG 10 -4 IN 1983 TTN 9 0 IN 1916 GED 13 -7 IN 1979 MPO -1 -12 IN 1970 SO, THIS WILL BE WIND DRIVEN COLD WITH MANY AREAS EXPERIENCING WIND CHILL VALUES OF 15 TO 25 BELOW ZERO...POSSIBLY 30 BELOW IN THE HILLS AND MOUNTAINS OF NORTHWEST NEW JERSEY AND NORTHEAST PENNSYLVANIA. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...GALE WARNING UNTIL 1 AM EST FRIDAY FOR ANZ450>455. GALE WARNING UNTIL 11 PM EST THIS EVENING FOR ANZ430-431. && $$ SYNOPSIS...FRANCK NEAR TERM...DRAG 954 SHORT TERM...DRAG LONG TERM...GAINES AVIATION...DRAG/GAINES 954 MARINE...DRAG/GAINES CLIMATE...954
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
930 AM EST THU FEB 11 2016 .SYNOPSIS... HIGH PRESSURE WILL BUILD EASTWARD INTO THE REGION TODAY AND THEN MOVE THROUGH THE REGION TONIGHT. AN ARCTIC COLD FRONTAL BOUNDARY WILL THEN MOVE THROUGH THE AREA FRIDAY NIGHT. BY SUNDAY, ANOTHER AREA OF HIGH PRESSURE WILL BUILD SOUTHWARD INTO THE REGION AS LOW PRESSURE FORMS ACROSS THE SOUTHERN UNITED STATES BY MONDAY. THIS AREA OF LOW PRESSURE WILL THEN TRACK UP THE EAST COAST TUESDAY INTO WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... 930 AM ESTF: WE THINK 1 TO 2 INCHES POSSIBLE IN NARROW BANDS. ALREADY UNCONFIRMED REPORT 1.5". HANDLING WITH SPS`S AND VIGOROUSLY UPDATED LEGACY AND POINT CLICK PRODUCTS. SNOW MAP UPDATING NOW BUT STILL GENERAL LESS THAN 1". 730 AM ESTF: UPDATED FOR THE SNOW BAND IN SE PA INTO SW NJ. ITS PUTTING DOWN A DUSTING THAT IS CAUSING SOME TRAVEL DIFFICULTY. A NOWCAST IS POSTED AS WELL UPDATED SNOWMAP AND FORECASTS FOR THIS MORNING. NO MODEL HAS THIS..N PART ..IN PART LES BAND TRAILING INTO OUR AREA. IF WE SEE VSBY 1 MI OR LESS WE WILL UPGRADE TO AN SPS. OUR RADAR CONTINUES IN VCP31 TO BETTER SEE THE FINER DETAILS, PLUS ITS LOW TOP AND VERY LOW WATER CONTENT. FROM THE MID SHIFT BELOW... FOR A RELATIVELY QUIET WEATHER DAY, STILL HAVE THREE MAIN STORIES TO TALK ABOUT FOR THE TODAY PERIOD. SNOW...AS MENTIONED BY THE PREVIOUS SHIFT, LOW TO MID LEVEL LAPSE RATES WILL BE QUITE STEEP ACROSS THE POCONOS AND NORTHERN NJ THROUGH AT LEAST MID DAY. IN ADDITION, THE MID AND UPPER LEVEL SHORT WAVE TROUGH WILL BE CROSSING THE REGION THROUGH THIS TIME. THESE FACTORS ARE CONDUCIVE FOR SCATTERED SNOW SHOWERS, OR MAYBE EVEN A FAST MOVING SNOW SQUALL, ACROSS THE NORTHERN HALF OF OUR REGION. WITH PERSISTENT DRY AIR ADVECTION, MOISTURE IS LIMITED. SO EVEN THOUGH SNOW/LIQUID RATIOS COULD BE ABOVE NORMAL THANKS TO THE VERY COLD AIR IN PLACE, STILL EXPECT SNOW ACCUMULATIONS TO REMAIN BELOW ONE INCH. WINDS...A TIGHT PRESSURE GRADIENT WILL REMAIN OVER THE REGION THROUGH AT LEAST 18Z BEFORE IT STARTS TO DECREASE AS THE SURFACE LOW LIFTS FURTHER AWAY FROM OUR REGION. THUS, EXPECT WINDY CONDITIONS THROUGH THE DAY. AT THIS POINT THOUGH, WIND ADVISORY CONDITIONS (SUSTAINED WINDS OF AT LEAST 31 MPH FOR AT LEAST ONE HOUR OR GUSTS OF 46 MPH) ARE NOT ANTICIPATED, SINCE THE TIGHTEST PRESSURE GRADIENT WILL BE EARLY IN THE DAY BEFORE THE MIXING LAYER GETS VERY DEEP. HAVING SAID THAT THOUGH, THE GFS DOES SHOW THAT THE SUSTAINED CRITERIA COULD BE REACHED FOR LOCATIONS ADJACENT TO THE DE BAY, SINCE THE DIRECTION IS A FAVORED DIRECTION FOR THE FUNNELING EFFECT OVER THE BAY. IN ADDITION, VAD WIND PROFILES SHOW THAT 40 KT WINDS ARE ABOUT 4000 TO 5000 FT MSL. IF THE MIXING LAYER GETS DEEP ENOUGH, SOME OF THAT COULD MIX DOWN FOR THE HIGHEST TERRAIN IN THE POCONOS AND NW NJ. FOR NOW THOUGH, CONFIDENCE IS LOW THAT IT WILL BE REACHED SO WILL NOT ISSUE AN ADVISORY AT THIS TIME. COLD...TODAY BEGINS THE COLD STRETCH WHICH WE ARE EXPECTING TO CONTINUE INTO THE WEEKEND. WHILE TODAY WILL PROBABLY BE THE WARMEST OF THE NEXT 4 DAYS, THE REGION SHOULD STAY BELOW FREEZING, AND PORTIONS OF THE POCONOS AND NW NJ MAY NOT GET OUT OF THE TEENS. THIS WILL BE 15 TO 20 DEGREES BELOW NORMAL. GIVEN THE WINDY CONDITIONS, WIND CHILL VALUES ACROSS THE REGION WILL ONLY TOP OUT IN THE TEENS AT BEST. && .SHORT TERM /FRIDAY/... HIGH BEGINS TO BUILD IN, AND CONSEQUENTLY WINDS DIMINISH, AND CLOUDS WILL DISSIPATE. AS A RESULT, SHOULD SEE CONSIDERABLE RADIATIONAL COOLING, WITH LOWS IN THE SINGLE DIGITS AND TEENS AND WIND CHILL VALUES IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... OUR UPDATED BRIEFING PACKAGE AT MIDDAY WILL INCLUDE MORE INFORMATION ON THE UPCOMING DANGEROUS COLD, INCLUDING A POSSIBLE WIND CHILL WATCH FOR SAT NIGHT WHICH IS ALREADY A HIGH CONFIDENCE LIKELIHOOD. THE EXTENDED WILL FEATURE BOTH THE PROSPECTS FOR THE COLDEST AIR OF THE SEASON CENTERED ON SUNDAY MORNING AND A STRENGTHENING LOW PRESSURE SYSTEM TRACKING UP THE EAST COAST EARLY NEXT WEEK. FRIDAY AND SATURDAY: HIGH PRESSURE WILL MOVE THROUGH THE REGION ON FRIDAY. THIS HIGH PRESSURE SYSTEM WILL GIVE WAY TO ANOTHER ARCTIC COLD FRONT FRIDAY NIGHT. THE COLD FRONT SHOULD PROVIDE ENOUGH LIFT AND MOISTURE FOR SOME SCATTERED SNOW SHOWERS TO DEVELOP. THESE MAY PRODUCE SOME LIGHT ACCUMULATIONS OF UNDER AN INCH. BEHIND THE FRONT, IT WILL BE A VERY COLD AND WINDY PERIOD WITH SOME ADDITIONAL SNOW SHOWERS AND/OR FLURRIES IN ASSOCIATION WITH THE NW FLOW OFF OF THE EASTERN GREAT LAKES. THE FAVORED REGIONS TO SEE SNOW SHOWERS ARE IN THE HIGH TERRAIN AREAS OF EASTERN PA AND NW NJ. BUFKIT ANALYSIS YIELDS THE POTENTIAL FOR 30-40 MPH GUSTS SATURDAY AFTERNOON ACROSS THE REGION WITH THE GFS BEING THE MOST AGGRESSIVE WITH THE GUST POTENTIAL. THE STRONG CAA WILL NOT ALLOW TEMPERATURES TO RISE MUCH DURING THE DAY. SATURDAY NIGHT THROUGH SUNDAY NIGHT: ANOTHER POTENT AREA OF ARCTIC HIGH PRESSURE WILL BUILD INTO THE REGION WITH THE COLDEST SHOT OF AIR OF THE SEASON SO FAR. MODELING HAS BEEN HOLDING STEADY ON THE IDEA THAT 850 MB TEMPERATURES LOOK TO DIVE BELOW -25C. WILL NUDGE TEMPERATURES A COUPLE OF DEGREES COOLER THAN MOST ENSEMBLE GUIDANCE THROUGH THE WEEKEND DUE TO THE DEGREE OF THE COLD AIR BEING MODELED. STRONG NORTHWEST WIND GUSTS, THOUGH NOT AS STRONG AS ON SATURDAY WILL CONTINUE IN THE WAKE OF THE DEPARTING SYSTEM. THE COLD AND WIND WILL RESULT IN WIND CHILLS FROM -10 TO -30 BELOW ZERO SATURDAY NIGHT AND SUNDAY MORNING. PLEASE TO MAKE SURE TO PREPARE FOR THE COLD WEATHER THAT IS COMING. PREPARATIONS INCLUDE CHECKING PIPES AND MAKING SURE YOUR VEHICLE IS IN GOOD WORKING CONDITION. LOW TEMPERATURES SUNDAY MORNING WILL LIKELY NEAR OR BELOW ZERO AS WELL. PLEASE REFER TO THE CLIMATE SECTION ON RECORD POTENTIAL. PRESIDENTS DAY THROUGH TUESDAY NIGHT: HIGH PRESSURE WILL GRADUALLY MOVE EAST OF THE REGION AND WILL GIVE WAY TO A STORM SYSTEM THAT IS CURRENTLY MODELED TO FORM ACROSS THE SOUTHERN UNITED STATES AND INTENSIFY AS IT MOVES UP THE EAST COAST. THE 00Z 2/11 OPERATIONAL MODELS HAVE NARROWED THE GOAL POSTS OF POSSIBLE TRACKS FROM EARLIER MODEL RUNS. THIS ALSO MATCHES OR IS JUST EAST OF THE 12Z 2/10 ECMWF ENSEMBLE MEAN TRACK. THIS TRACK GOES FROM SOUTH CENTRAL AL/GA NORTHEAST TO THE CAROLINA COASTLINE THEN DUE NORTH UP THE EAST COAST INTO SOUTHERN NEW ENGLAND. TWO MAIN FEATURES ARE PRESENT TO TRACK WITH REGARDS TO MODELS OR RESPECTIVE ENSEMBLES CHANGING THE FORECAST TRACK OF THIS SYSTEM IN FUTURE RUNS. THIS FIRST IS A LEADING SHORTWAVE WHICH MOVES INTO THE THE OHIO VALLEY ON MONDAY AND THE SECOND IS THE DEGREE OF MID- LEVEL HEIGHT RISES THAT OCCUR AHEAD OF THE STORM SYSTEM. A STRONGER SHORTWAVE WOULD TEND TO PUSH THE OVERALL TROUGH WITH THIS STORM FURTHER EAST. WHILE A WEAKER SHORTWAVE WOULD ALLOW FOR HIGHER MID- LEVEL HEIGHT RISES LEADING TO A FURTHER WEST TRACK OF THE LOW. RIGHT NOW THE FAVORED TRACK WOULD RESULT IN SNOW CHANGING TO RAIN ACROSS MOST OF THE REGION WITH THE HIGHEST CHANCES FOR PRECIPITATION MONDAY NIGHT AND TUESDAY. IT WILL LIKELY BE WINDY AS WELL WITH THE STRENGTHENING LOW PRESSURE SYSTEM TRACKING NEAR THE REGION. WEDNESDAY: THE REGION SHOULD GRADUALLY BEGIN TO CLEAR OUT AS ANOTHER HIGH PRESSURE SYSTEM BUILDS EASTWARD TOWARD THE REGION. SOME UNCERTAINTY THOUGH AS 2/11 00Z ECMWF BRINGS ANOTHER SYSTEM INTO THE REGION BY THIS PERIOD. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...VFR SCT-BKN AOA 4000 FT. BRIEF IFR CONDS IN SNOW SHOWERS VCNTY KPHL NORTH THROUGH TTN ABE AND RDG. TIMING UNCERTAIN AND HANDLING AS NEAR TERM FCST. THESE MESOSCALE BANDS DONT APPEAR TO BE WELL HANDLED BY OUR HRRR HRRRX PRODUCTS NOR RUC/RAP. NEW 12Z/11 NAM HAS A NEW BAND DEVELOPING NEAR AND N OF I-80 THIS AFTN. BASICALLY A LES CONNECTION FROM LERIE SEWD INTO SRN PA AND THEN EWD TO NEAR PHL. THAT MAY REFOCUS NEAR I80 OR I78 THIS AFTN. WEST WIND GUSTS INCREASING TO 30 KT BY 16Z. ISOLATED 35 KT POSSIBLE. TONIGHT...VFR SCT-BKN CLOUDS AOA 4000 FT DURING THE EVENING BECOMING CLEAR. GUSTY WNW WINDS 20-30 KT SLOWLY DIMINISHING DURING THE NIGHT. OUTLOOK... FRIDAY: VFR. FRIDAY NIGHT AND SATURDAY: MAINLY VFR, POSSIBLE MVFR RESTRICTIONS IN SCATTERED SNOW SHOWERS. NORTHWEST WINDS INCREASING SATURDAY FROM 15-25 KNOTS WITH GUSTS UP TO 40 KNOTS SATURDAY AFTERNOON. SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED. NORTHWEST WINDS 10 TO 25 KNOTS. MONDAY...VFR CONDITIONS FOR MOST OF THE DAY THEN BECOMING MVFR AND IFR BY EVENING WITH RAIN AND SNOW. && .MARINE... GALES IN PROGRESS AND GLW CONTINUES AS POSTED. AN SCA WILL BE NEEDED FOR MUCH IF NOT ALL OF THE OVER NIGHT HOURS ONCE THE GALES SUBSIDE. LIGHT FREEZING SPRAY IS OCCURRING AND CONTINUES TO BE EXPECTED ON THE BAY AS WELL AS THE NEAR COASTAL WATERS. OUTLOOK... OUR AFTERNOON MARINE PRODUCTS WILL HEADLINE A NEW HIGH CONFIDENCE GALE WATCH FOR THE PERIOD ROUGHLY 4 AM SATURDAY THROUGH 8 AM SUNDAY. SO WHILE, SEAS AND WINDS WILL START OUT FAIRLY LIGHT ON FRIDAY. HOWEVER, A QUICK RAMP UP IS EXPECTED AFTER THE PASSAGE OF AN ARCTIC COLD FRONTAL BOUNDARY FRIDAY NIGHT. NORTHWEST WINDS WILL INCREASE AND REACH GALE FORCE BY SATURDAY AND CONTINUE GALE FORCE THROUGH SATURDAY NIGHT. CONFIDENCE FOR GALES ON SATURDAY IS VERY HIGH. SEAS WILL RISE TO BETWEEN 5 AND 7 FEET FOR A PERIOD AS WELL ON SATURDAY. SEAS AND WINDS ARE EXPECTED TO DECREASE ON SUNDAY. WAVE HEIGHTS WILL LIKELY START INCREASING AGAIN BY MONDAY NIGHT IN RESPONSE TO A DEVELOPING LOW PRESSURE SYSTEM TO OUR SOUTH. && .CLIMATE... NEAR RECORD COLD IS EXPECTED FOR PORTIONS OF OUR AREA SUNDAY MORNING AND BY FAR THE COLDEST AIR OF THE SEASON SO FAR. ANTICIPATING TEMPS THROUGHOUT OUR FORECAST AREA WITHIN SEVERAL DEGREES OF ZERO (WIND IS THE EQUALIZER) ANYTIME FROM MIDNIGHT THROUGH 8 AM SUNDAY EXCEPT COLDER KMPO (NEAR -12F). THIS HAS BEEN ADVERTISED BY THE GFS/ECMWF 2M TEMPS CYCLICALLY SINCE AT LEAST THE 00Z/7 OPERATIONAL CYCLES. THEREFORE, BEST CHANCE FOR RECORD EQUALING OR EXCEEDING FOR VALENTINES DAY THE 14TH WOULD BE KABE, KTTN, KPHL AND KMPO. SNOW COVER MAY HELP A BIT I-95 NORTHWESTWARD...AND WE`LL SEE WHERE WE ARE WITH SNOW COVER BY THURSDAY EVENING. NEW DUSTINGS APPEAR ON THE WAY THROUGH FRIDAY NIGHT. AS AN ADDED NOTE HERE... GUIDANCE IN PART IS BEING CLIMO BIASED HIGHER THAN WHAT THE ONCOMING GFS/ECMWF LITERAL AIRMASS AND 2M TEMPS ARE INDICATING FOR SUNDAY MORNING. TEMPS SUNDAY MORNING IN THE URBAN AREAS SHOULD BE ABOUT 25 COLDER THAN NORMAL. THAT MEANS GUIDANCE TEMPS FOR PHL OF 5 AND 6 DEGREES APPEAR TOO WARM...ESPECIALLY WITH A NORMAL PHILADELPHIA LOW ON SUNDAY OF 28. RECORD LOW MAX`S CAN ONLY OCCUR FOR THIS EVENT ON SUNDAY THE 14TH, IF THEN. SITE 2015-16 COLDEST SO FAR RECORD LOW FEB. 14TH ----RER LOW MAX ---------------------- -------------------- ABE 8 -1 IN 1979 14-1979 ACY 10 -6 IN 1979 13-1979 PHL 12 +2 IN 1979 14-1979 ILG 12 -4 IN 1979 13-1979 RDG 10 -4 IN 1983 TTN 9 0 IN 1916 GED 13 -7 IN 1979 MPO -1 -12 IN 1970 SO, THIS WILL BE WIND DRIVEN COLD WITH MANY AREAS EXPERIENCING WIND CHILL VALUES OF 15 TO 25 BELOW ZERO...POSSIBLY 30 BELOW IN THE HILLS AND MOUNTAINS OF NORTHWEST NEW JERSEY AND NORTHEAST PENNSYLVANIA. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...GALE WARNING UNTIL 1 AM EST FRIDAY FOR ANZ450>455. GALE WARNING UNTIL 11 PM EST THIS EVENING FOR ANZ430-431. && $$ SYNOPSIS...FRANCK NEAR TERM...DRAG/JOHNSON 930A SHORT TERM...JOHNSON LONG TERM...GAINES AVIATION...DRAG/GAINES/JOHNSON 930A MARINE...DRAG/GAINES/JOHNSON 930A CLIMATE...
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
859 PM CST FRI FEB 12 2016 .UPDATE... ISSUED AT 859 PM CST FRI FEB 12 2016 Skies have become clear this evening and should remain that way the rest of the night. Any additional clouds will be very late tonight or early tomorrow morning and be cirrus clouds. Winds remain gusty and am expecting this to continue as forecast as well. Gusty winds will keep air mixed, but dewpoints are in the single digits over most of the area, so still think temps by morning will be in the single digits to just below zero in the northwest. Only change needed is to adjust cloud cover to better reflect current conditions. Update will be out shortly. && .SHORT TERM...(Tonight) ISSUED AT 255 PM CST FRI FEB 12 2016 A weak clipper system will exit southeast of central IL late this afternoon, with its diminishing area of very light snow/flurries se of the IL river ending soon, with best light snow chances east of IL over central IN. MVFR clouds already scattering nw of the IL river like at PIA and HRRR model handling this clearing well. These clouds to decrease se of the IL river during late afternoon/early evening, and over southeast IL by mid evening. Brisk NW winds of 15-25 mph and gusts to 30 mph will gradually diminish during the night, reaching 5-15 mph later tonight. Strong 1046 mb polar high pressure west of Lake Winnipeg Canada to settle se into MN/IA by sunrise Sat and bring a frigid night to the region. Lows by early Saturday morning range from around zero north of I-72 to 4-8F in southeast IL from I-70 southeast. Wind chills by dawn will range from 5-15 below zero with a few spots from I-74 north dipping to 15-17 below zero like at Bloomington, Galesburg and Champaign. Will hold off on a wind chill advisory overnight into mid Sat morning, but will issue SPS to address these bitter cold wind chills especially in our northern CWA. .LONG TERM...(Saturday through Friday) ISSUED AT 255 PM CST FRI FEB 12 2016 Very cold conditions expected to start the day Saturday across central and southeast Illinois as Arctic high pressure builds across the area. The relatively slight pressure gradient that will accompany the surface high should keep Wind Chill values warmer than advisory criteria for the most part, but high temperatures should only top out in the teens. Beyond the initially cold conditions, our attention turns to an approaching clipper system, which is likely to be the most significant weather system to impact the area over the next week. This clipper has trended faster in recent model runs, with snow now expected to start breaking locally after midnight Saturday night/Sunday morning. The system will be pushing into a very dry airmass which should limit the snow accumulation to some degree. However, fairly strong isentropic ascent and mixing ratios of 2-3 G/KG over at least a 12 hour period should be able to produce 2"=4" snow totals. In fact, would not be surprised if we need to boost accumulations further once the exact track of the system is more clear (it has trended s bit south in the latest runs). One other thing that will need to be monitored is that the moisture depth is progged to be rather shallow during the period of potential snow. This fact is also a reason to limit snow accumulations for now, and we also need to monitor the threat for freezing drizzle due to a potential lack of ice crystals. The faster trend of the clipper system should now have Monday ending up dry. Another weak clipper system may impact the area Tuesday into Tuesday night, but it does not appear significant at this time. After that, the next chance for precipitation should not occur before the end of the week. However, model agreement in the details of the late week system is weak at best. Temperatures should gradually be trending warmer next week, with well above normal temperatures likely by the end of the week (near 50 degrees for highs). If these trends hold, the late week system, if/when it impacts the area, should be a rain producer. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) ISSUED AT 518 PM CST FRI FEB 12 2016 VFR conditions will continue at all TAF sites next 24hrs. Clouds are clearing from the area so all sites will be SKC to start and then continue that way remainder of the night and into tomorrow morning. Models bring in some high cirrus tomorrow in advance of the next weather system, so have added SCT250 at all sites from morning and through the day. Main issue is the wind speeds...with gusty winds continuing this evening and into the overnight hours. Then winds taper and sites will loose the gusts. Tomorrow winds should be around 12kts of less. Wind direction will continue to be northwest through the next 24hrs. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Auten SHORT TERM...07 LONG TERM...BAK AVIATION...Auten
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
517 PM CST FRI FEB 12 2016 .SHORT TERM...(Tonight) ISSUED AT 255 PM CST FRI FEB 12 2016 A weak clipper system will exit southeast of central IL late this afternoon, with its diminishing area of very light snow/flurries se of the IL river ending soon, with best light snow chances east of IL over central IN. MVFR clouds already scattering nw of the IL river like at PIA and HRRR model handling this clearing well. These clouds to decrease se of the IL river during late afternoon/early evening, and over southeast IL by mid evening. Brisk NW winds of 15-25 mph and gusts to 30 mph will gradually diminish during the night, reaching 5-15 mph later tonight. Strong 1046 mb polar high pressure west of Lake Winnipeg Canada to settle se into MN/IA by sunrise Sat and bring a frigid night to the region. Lows by early Saturday morning range from around zero north of I-72 to 4-8F in southeast IL from I-70 southeast. Wind chills by dawn will range from 5-15 below zero with a few spots from I-74 north dipping to 15-17 below zero like at Bloomington, Galesburg and Champaign. Will hold off on a wind chill advisory overnight into mid Sat morning, but will issue SPS to address these bitter cold wind chills especially in our northern CWA. .LONG TERM...(Saturday through Friday) ISSUED AT 255 PM CST FRI FEB 12 2016 Very cold conditions expected to start the day Saturday across central and southeast Illinois as Arctic high pressure builds across the area. The relatively slight pressure gradient that will accompany the surface high should keep Wind Chill values warmer than advisory criteria for the most part, but high temperatures should only top out in the teens. Beyond the initially cold conditions, our attention turns to an approaching clipper system, which is likely to be the most significant weather system to impact the area over the next week. This clipper has trended faster in recent model runs, with snow now expected to start breaking locally after midnight Saturday night/Sunday morning. The system will be pushing into a very dry airmass which should limit the snow accumulation to some degree. However, fairly strong isentropic ascent and mixing ratios of 2-3 G/KG over at least a 12 hour period should be able to produce 2"=4" snow totals. In fact, would not be surprised if we need to boost accumulations further once the exact track of the system is more clear (it has trended s bit south in the latest runs). One other thing that will need to be monitored is that the moisture depth is progged to be rather shallow during the period of potential snow. This fact is also a reason to limit snow accumulations for now, and we also need to monitor the threat for freezing drizzle due to a potential lack of ice crystals. The faster trend of the clipper system should now have Monday ending up dry. Another weak clipper system may impact the area Tuesday into Tuesday night, but it does not appear significant at this time. After that, the next chance for precipitation should not occur before the end of the week. However, model agreement in the details of the late week system is weak at best. Temperatures should gradually be trending warmer next week, with well above normal temperatures likely by the end of the week (near 50 degrees for highs). If these trends hold, the late week system, if/when it impacts the area, should be a rain producer. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) ISSUED AT 518 PM CST FRI FEB 12 2016 VFR conditions will continue at all TAF sites next 24hrs. Clouds are clearing from the area so all sites will be SKC to start and then continue that way remainder of the night and into tomorrow morning. Models bring in some high cirrus tomorrow in advance of the next weather system, so have added SCT250 at all sites from morning and through the day. Main issue is the wind speeds...with gusty winds continuing this evening and into the overnight hours. Then winds taper and sites will loose the gusts. Tomorrow winds should be around 12kts of less. Wind direction will continue to be northwest through the next 24hrs. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...07 LONG TERM...BAK AVIATION...Auten
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
324 PM CST THU FEB 11 2016 .SHORT TERM...(Tonight) ISSUED AT 323 PM CST THU FEB 11 2016 A fast moving clipper will produce light snow starting this evening across western Illinois, with most of the focused lift overnight primarily remaining across our southwestern counties. The general trend in the 12z models has been to focus the better chances of measurable snowfall over our southwestern and southern counties. Have increased PoPs to likely in a narrow corridor southwest of a line from Jacksonville to Effingham, progressing from SW to SE with time overnight. The HRRR is the farthest southwest with the latest updated path of forcing for precip, with the NAM80, Canadian GEM, and ECMWF still extending at least some snow accumulation across all of our CWA except the far NE counties NE of CMI. The NAM12 is similar to the HRRR in limiting snow to the SW half of our CWA. Have reduced the PoPs in our N and NE counties, north of I-74, to slight chance. Chance PoPs were limited to generally south of a line from Galesburg to Lincoln to Paris. Snow amounts from Jacksonville to Effingham could reach between a half inch and one inch, with a dusting to a half inch as far north as Rushville to Lincoln to Decatur. South to southwest winds should remain less than 10 mph during the snowfall, so drifting should not be a big problem overnight. Low temps tonight will generally settle out in the mid-teens, as cloud cover limits the diurnal swing to only around a 10 degree drop- off. && .LONG TERM...(Friday through Thursday) ISSUED AT 323 PM CST THU FEB 11 2016 Friday may start out with a few lingering snow showers south of I-70, but little additional accumulation is expected after sunrise. The bigger story will be the arrival of very cold air on increasing northwest winds Friday afternoon, as strong pressure rises develop ahead of the surface high center. The tight pressure gradient will produce wind gusts over 30 mph at times, which could cause minor drifting of the snowfall from tonight, so slippery travel could develop from that Friday afternoon and evening. Wind chills late Friday night will drop very close to advisory levels of -15F north of Peoria, with wind chills below zero in all of our forecast area. Actual air temps will be range from zero to 8 above zero, but NW winds will remain strong enough to push wind chills well below zero. The next main concern will be the system for Sunday into Monday. Model differences remain with the 12z model updates. The Canadian GEM has started showing the splitting of energy as the trough reaches Illinois, similar to what the ECMWF was showing yesterday. The ECMWF has changed and now maintains the trough energy across Illinois Sunday evening, with total QPF amounts that support snow amounts of 1 to 2". The Canadian GEM QPF amounts support around 1 inch west of I-55, with little to no snow accum east of I-55. The GFS remains the only model that develops a distinct surface low/circulation that tracks across northern IL Sunday evening, with total QPF amounts that support snowfall of 4" to 7" in our northern counties, and 3-4" in the south. The 12z NAM now includes forecast info through 6 pm Sunday, and is showing plenty of snow as well, despite no surface low moving across IL. The NAM has 3-5" across our counties for just the first 12 hours of the event through 6 pm Sunday. We have increased PoPs into the likely category for Sunday nearly everywhere, and likely PoPs east of I-57 Sunday night. Our compromise forecast for QPF came out to 0.23-0.30", correlating to snowfall amounts of 2-4", with the higher totals from Peoria and north. There still remains quite a bit of uncertainty with how much moisture will fall, so updates to QPF and resultant snow accums are likely with subsequent model runs. The accumulating snows should primarily be done by Monday morning, but lingering light snow or flurries could continue into afternoon. If precip does linger into the afternoon, the snow may mix with or change to rain. All of the extended models show a low deepening south of Illinois on Monday, and progressing up into the Appalachian mountains Monday night, with precip mainly southeast of our area. However, the blended initialization kept slight chance PoPs in the eastern half of Illinois Monday night through Tuesday night, mainly due to that strong system. A warming trend is indicated for next week, as upper level ridging gradually pushes east into Illinois. We should see mid-level warming increase enough to support high temps climbing into the upper 30s to low 40s Tuesday and Wed, with sunshine and mid 40s to around 50 for Thursday. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 1155 AM CST THU FEB 11 2016 1030 MB Canadian high pressure over the upper MS river valley and ridging into eastern IA and nw IL will slide se into eastern IL and central/southern IN by 00Z/6 pm and into WV by 06Z/midnight tonight. Nearby high pressure will continue light winds through this evening across the central TAF sites. A northern stream short wave/Alberta clipper over western SD will track se across MO during this evening and into the TN valley by 12Z/6 am Friday. Models have trended further sw track with this clipper so best chances of light snow tonight have shifted sw into sw IL from SPI sw. Have light snow/flurries with vsbys 4-6 miles and MVFR ceilings spreading se along I-74 corridor 02-06Z. Steadier light snow and vsbys down to 2-3 miles at DEC and especially SPI from 03Z-05Z along with MVFR ceilings. Light snow chances should end late tonight from nw-se from 10-13Z as MVFR clouds linger. Light winds this evening to become WNW by dawn Friday and increase to 10-15 kts with gusts 15-20 kts after 15Z/9 am Fri. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Shimon LONG TERM...Shimon AVIATION...07
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1019 PM EST FRI FEB 12 2016 .SYNOPSIS... ISSUED AT 1016 PM EST FRI FEB 12 2016 ARCTIC AIR WILL CONTINUE TO SPREAD ACROSS THE REGION OVERNIGHT ACCOMPANIED BY GUSTY WINDS AND NUMEROUS LAKE EFFECT SNOW SHOWERS. THE LAKE EFFECT SNOW WILL MAINLY IMPACT SOUTHWEST MICHIGAN AND NORTH CENTRAL INDIANA WHERE 3 TO 6 INCHES OF ADDITIONAL ACCUMULATION ARE EXPECTED TONIGHT AND SATURDAY. LOWS TONIGHT WILL BE IN THE SINGLE DIGITS WITH HIGHS SATURDAY NEAR 15. && .UPDATE... ISSUED AT 734 PM EST FRI FEB 12 2016 POST FNTL SHSN WITHIN EMERGING ARCTIC AIRMASS QUITE INTENSE IN SPOTS YET THIS EVENING BUT WILL CONT TO DIMINISH AS UNSTABLE SFC BASED LAPSE RATES DECAY W/SUNSET. REGARDLESS GROWING QUITE CONCERNED W/UPSTREAM LAKE RESPONSE WITHIN EVOLVING/INTENSIFYING LL THERMAL TROUGH. GENERAL CONSOLIDATION IN BANDING NOTED OVR THE LAST 3 HOURS ALG A MUSKEGON TO ALLEGAN LINE...MIMICKING RECENT RAP MODEL INDICATIONS AS LL FLW VEERS CONSIDERABLY W/UPSTREAM EXTENT. THIS PRIMARY PLUME XPCD/MODELED TO INTENSIFY AS IT COMES SOUTH THROUGH LT EVENING BFR LOCKING IN WITHIN ROUGHLY ALG A SOUTH HAVEN...CASSOPOLIS...ELKHART...WARSAW LINE. BASED ON OBSVD RADAR TRENDS...SUSPECT NR 1" PER HOUR PEAK SNOWFALL RATES WHICH MAY REQUIRE SOME FORM OF HEADLINE ADJUSTMENT. WILL ATTM FOLLOW EVOLUTION OF THIS BAND THROUGH MID EVENING AND MAKE A DECISION IF NEEDED WELL BFR 11 PM. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 306 PM EST FRI FEB 12 2016 CDFNT MOVG RAPIDLY E-SE ACROSS THE CWA THIS AFTN ACCOMPANIED BY A BAND OF SNOW SHOWERS. LAKE EFFECT SNOW SHOWERS DVLPG BEHIND THE FRONT SHOULD GRDLY INTENSIFY THIS EVE AS CAA CONTS AND WINDS VEER FROM AROUND 300 DEGREES TO 340 DEGREES AS A SECONDARY CDFNT CURRENTLY OVER NRN LWR MI MOVES THROUGH OUR AREA. INVERSION BASE FORECAST TO PEAK LATE THIS EVE AROUND 6500FT WITH SIGNIFICANT LAKE INDUCED INSTABILITY (0-2KM THETA-E LAPSE RATES OVER THE LAKE AROUND -2.5C/KM). CONVECTION ALLOWING MODELS SUGGEST A DOMINANT BAND OR TWO WILL SET UP AROUND THIS TIME IMPACTING NORTHWEST PORTION OF OUR CWA. HWVR, THESE OPTIMAL CONDITIONS FOR LES SHOULD BE SHORT LIVED AS INVERSION FCST TO LOWER/LAKE INDUCED INSTABILITY DECREASE LATE TONIGHT AND THROUGH THE DAY SATURDAY. DGZ WILL ALSO BE VERY LOW GIVEN ARCTIC AIRMASS MOVG IN WHICH SHOULD LIMIT ACCUMS BLO WHAT OTRWS MIGHT BE EXPECTED. ONLY MINOR CHANGE MADE TO PREVIOUS FCST ACCUMS WITH TOTALS TONIGHT AND SATURDAY EXPECTED TO BE IN THE 3-6" RANGE IN THE ADVISORY AREA WITH 1-3" IN COUNTIES SURROUNDING ADVISORY AND <1" OVER THE REST OF THE CWA. LOCALLY HIGHER AMOUNTS PSBL IF DOMINANT BAND PERSISTS OVER ANY GIVEN AREA VERY LONG THIS EVENING. BOUNDARY LAYER WINDS FCST 15-25KT TONIGHT WHICH SHOULD CAUSE CONSIDERABLE BLOWING DRIFTING OF THE POWDERY LES, MAINLY IN THE NW ADVISORY AREA. LITTLE CHANGE MADE TO TEMPS WITH LOWS TONIGHT IN THE 0-5 RANGE NE AND SW WHERE SOME PARTIAL CLEARING EXPECTED AND 5-10 UNDER THE LAKE EFFECT CLOUD PLUME OVER MOST OF THE REST OF THE CWA, WITH HIGHS SATURDAY ONLY 12-16. MINIMUM WIND CHILLS TONIGHT AND SATURDAY MORNING EXPECTED TO BE IN THE -5 TO -15 RANGE. && .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 306 PM EST FRI FEB 12 2016 LAKE EFFECT SNOW WILL TAPER OFF SATURDAY EVENING AS LOW LEVEL RIDGE AXIS SHIFTS OVERHEAD AND INVERSION HEIGHTS LOWER. DGZ REMAINS ACTIVE IN THE 00-06Z TIMEFRAME SO SOME LIGHT FLURRIES/SNOW SHOWERS EXPECTED BUT ANY ADDITIONAL ACCUMULATION WILL BE VERY LIGHT. MAIN STORY FOR SATURDAY NIGHT WILL BE VERY COLD TEMPS. LIGHT WINDS...PARTIALLY CLEAR SKIES...AND FRESH SNOW WILL SUPPORT GOOD RADIATIONAL COOLING POTENTIAL IN SPOTS. GRADIENT WIND/WAA AND CLOUDS BEGIN TO INCREASE TOWARD 12Z BUT SHOULD STILL BE ENOUGH TIME FOR TEMPS TO DROP. KEPT CLOSE TO INHERITED FORECAST...WHICH IS ON THE COLD SIDE OF GUIDANCE...WITH LOWS AROUND ZERO. WILL LIKELY BE A HIGH DEGREE OF VARIANCE IN FINAL NUMBERS THOUGH...DEPENDING ON EXACT CLOUD TRENDS. CHANCE FOR LIGHT SNOW THEN QUICKLY RETURNS LATE SUNDAY AS NEXT SHORTWAVE ROTATES THROUGH THE REGION. CONFLUENT FLOW OVER THE EASTERN CONUS WILL INCREASINGLY SHEAR OUT AND WEAKEN THIS WAVE. CVA BECOMES NEGLIGIBLE BY SUNDAY NIGHT WITH JUST SOME BROAD/WEAK 280- 285K ISENTROPIC ASCENT. DO SEE A DECENT MOISTURE SURGE THOUGH WITH MIXING RATIOS OVER 2 G/KG. GIVEN STEADY...ALBEIT WEAK...ASCENT AND POTENTIAL FOR HIGHER THAN CLIMO SNOW RATIOS...COULD CHURN OUT 1-2" BY LATE MONDAY MORNING. BEST CHANCES FOR HIGHER AMOUNTS WILL BE IN OUR SOUTHWEST WHERE BETTER MOISTURE AND FORCING RESIDE. AFTER A BRIEF BREAK MONDAY NIGHT...THERE IS ANOTHER CHANCE FOR SNOW TUESDAY/TUESDAY NIGHT AS POTENT NORTHERN STREAM SHORTWAVE DIVES SOUTHEAST AND STRENGTHENS EAST COAST LOW. MODELS HAVE BEEN KEEPING PRECIP SHIELD OF PRIMARY LOW JUST EAST OF OUR CWA BUT CONTINUE TO STRUGGLE IMMENSELY WITH EXACT TRACK OF SECONDARY VORT MAX. CONFIDENCE IN SNOW CHANCES REMAINS LOW AT THIS POINT WITH PARENT JET ENERGY STILL WELL OUT OVER THE DATA-SPARSE NORTH PACIFIC. WILL CONTINUE TO WATCH THIS PERIOD AND ADJUST AS MODELS GET A BETTER HANDLE ON SITUATION. SOME MINOR LAKE EFFECT THEN POSSIBLE WEDNESDAY WITH MUCH WARMER TEMPS (AND POTENTIAL FOR RAIN) STILL EXPECTED BY THE END OF THE WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 651 PM EST FRI FEB 12 2016 PRIMARY LAKE SNOW BANDING ALREADY WELL UNDERWAY FROM STONY POINT SWD TO NR SAUGATUCK INLINE W/RAP TRENDS AS LL FLW CONTS TO VEER IN WAKE OF SW PASSAGE. GIVEN GOOD CONTINUITY OF NR TERM MODEL SIGNALS HAVE SHIFTED FWD TIME OF GREATEST IMPACT INVOF OF KSBN AND FULLY XPC A PD OF LIFR CONDS TO MANIFEST AFT 06Z. INLAND REACH OF THIS PRIMARY BAND MAY AFFECT FWA TERMINAL BRIEFLY PRIOR TO 06Z BUT OF QUITE LIMITED DURATION AND LEFT OUT ATTM. WILL AMEND ACCORDINGLY AS NEEDED. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 4 PM EST /3 PM CST/ SATURDAY FOR INZ003>005. MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST SATURDAY FOR MIZ077>079. OH...NONE. LM...HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST SATURDAY FOR LMZ043- 046. GALE WARNING UNTIL 7 AM EST SATURDAY FOR LMZ043-046. && $$ UPDATE...T SYNOPSIS...JT/SKIPPER SHORT TERM...JT LONG TERM...AGD AVIATION...T VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
735 PM EST FRI FEB 12 2016 .SYNOPSIS... ISSUED AT 306 PM EST FRI FEB 12 2016 AN ARCTIC FRONT WILL CONTINUE TO MOVE THROUGH THE AREA LATE THIS AFTERNOON ACCOMPANIED BY NUMEROUS SNOW SHOWERS. LAKE EFFECT SNOW AND BITTER COLD WILL FOLLOW THE ARCTIC FRONT TONIGHT AND SATURDAY. THE LAKE EFFECT SNOW WILL MAINLY IMPACT SOUTHWEST MICHIGAN AND NORTH CENTRAL INDIANA WHERE 3 TO 6 INCHES OF ADDITIONAL ACCUMULATION ARE EXPECTED TONIGHT AND SATURDAY. LOWS TONIGHT WILL BE IN THE SINGLE DIGITS WITH HIGHS SATURDAY NEAR 15. && .UPDATE... ISSUED AT 734 PM EST FRI FEB 12 2016 POST FNTL SHSN WITHIN EMERGING ARCTIC AIRMASS QUITE INTENSE IN SPOTS YET THIS EVENING BUT WILL CONT TO DIMINISH AS UNSTABLE SFC BASED LAPSE RATES DECAY W/SUNSET. REGARDLESS GROWING QUITE CONCERNED W/UPSTREAM LAKE RESPONSE WITHIN EVOLVING/INTENSIFYING LL THERMAL TROUGH. GENERAL CONSOLIDATION IN BANDING NOTED OVR THE LAST 3 HOURS ALG A MUSKEGON TO ALLEGAN LINE...MIMICKING RECENT RAP MODEL INDICATIONS AS LL FLW VEERS CONSIDERABLY W/UPSTREAM EXTENT. THIS PRIMARY PLUME XPCD/MODELED TO INTENSIFY AS IT COMES SOUTH THROUGH LT EVENING BFR LOCKING IN WITHIN ROUGHLY ALG A SOUTH HAVEN...CASSOPOLIS...ELKHART...WARSAW LINE. BASED ON OBSVD RADAR TRENDS...SUSPECT NR 1" PER HOUR PEAK SNOWFALL RATES WHICH MAY REQUIRE SOME FORM OF HEADLINE ADJUSTMENT. WILL ATTM FOLLOW EVOLUTION OF THIS BAND THROUGH MID EVENING AND MAKE A DECISION IF NEEDED WELL BFR 11 PM. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 306 PM EST FRI FEB 12 2016 CDFNT MOVG RAPIDLY E-SE ACROSS THE CWA THIS AFTN ACCOMPANIED BY A BAND OF SNOW SHOWERS. LAKE EFFECT SNOW SHOWERS DVLPG BEHIND THE FRONT SHOULD GRDLY INTENSIFY THIS EVE AS CAA CONTS AND WINDS VEER FROM AROUND 300 DEGREES TO 340 DEGREES AS A SECONDARY CDFNT CURRENTLY OVER NRN LWR MI MOVES THROUGH OUR AREA. INVERSION BASE FORECAST TO PEAK LATE THIS EVE AROUND 6500FT WITH SIGNIFICANT LAKE INDUCED INSTABILITY (0-2KM THETA-E LAPSE RATES OVER THE LAKE AROUND -2.5C/KM). CONVECTION ALLOWING MODELS SUGGEST A DOMINANT BAND OR TWO WILL SET UP AROUND THIS TIME IMPACTING NORTHWEST PORTION OF OUR CWA. HWVR, THESE OPTIMAL CONDITIONS FOR LES SHOULD BE SHORT LIVED AS INVERSION FCST TO LOWER/LAKE INDUCED INSTABILITY DECREASE LATE TONIGHT AND THROUGH THE DAY SATURDAY. DGZ WILL ALSO BE VERY LOW GIVEN ARCTIC AIRMASS MOVG IN WHICH SHOULD LIMIT ACCUMS BLO WHAT OTRWS MIGHT BE EXPECTED. ONLY MINOR CHANGE MADE TO PREVIOUS FCST ACCUMS WITH TOTALS TONIGHT AND SATURDAY EXPECTED TO BE IN THE 3-6" RANGE IN THE ADVISORY AREA WITH 1-3" IN COUNTIES SURROUNDING ADVISORY AND <1" OVER THE REST OF THE CWA. LOCALLY HIGHER AMOUNTS PSBL IF DOMINANT BAND PERSISTS OVER ANY GIVEN AREA VERY LONG THIS EVENING. BOUNDARY LAYER WINDS FCST 15-25KT TONIGHT WHICH SHOULD CAUSE CONSIDERABLE BLOWING DRIFTING OF THE POWDERY LES, MAINLY IN THE NW ADVISORY AREA. LITTLE CHANGE MADE TO TEMPS WITH LOWS TONIGHT IN THE 0-5 RANGE NE AND SW WHERE SOME PARTIAL CLEARING EXPECTED AND 5-10 UNDER THE LAKE EFFECT CLOUD PLUME OVER MOST OF THE REST OF THE CWA, WITH HIGHS SATURDAY ONLY 12-16. MINIMUM WIND CHILLS TONIGHT AND SATURDAY MORNING EXPECTED TO BE IN THE -5 TO -15 RANGE. && .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 306 PM EST FRI FEB 12 2016 LAKE EFFECT SNOW WILL TAPER OFF SATURDAY EVENING AS LOW LEVEL RIDGE AXIS SHIFTS OVERHEAD AND INVERSION HEIGHTS LOWER. DGZ REMAINS ACTIVE IN THE 00-06Z TIMEFRAME SO SOME LIGHT FLURRIES/SNOW SHOWERS EXPECTED BUT ANY ADDITIONAL ACCUMULATION WILL BE VERY LIGHT. MAIN STORY FOR SATURDAY NIGHT WILL BE VERY COLD TEMPS. LIGHT WINDS...PARTIALLY CLEAR SKIES...AND FRESH SNOW WILL SUPPORT GOOD RADIATIONAL COOLING POTENTIAL IN SPOTS. GRADIENT WIND/WAA AND CLOUDS BEGIN TO INCREASE TOWARD 12Z BUT SHOULD STILL BE ENOUGH TIME FOR TEMPS TO DROP. KEPT CLOSE TO INHERITED FORECAST...WHICH IS ON THE COLD SIDE OF GUIDANCE...WITH LOWS AROUND ZERO. WILL LIKELY BE A HIGH DEGREE OF VARIANCE IN FINAL NUMBERS THOUGH...DEPENDING ON EXACT CLOUD TRENDS. CHANCE FOR LIGHT SNOW THEN QUICKLY RETURNS LATE SUNDAY AS NEXT SHORTWAVE ROTATES THROUGH THE REGION. CONFLUENT FLOW OVER THE EASTERN CONUS WILL INCREASINGLY SHEAR OUT AND WEAKEN THIS WAVE. CVA BECOMES NEGLIGIBLE BY SUNDAY NIGHT WITH JUST SOME BROAD/WEAK 280- 285K ISENTROPIC ASCENT. DO SEE A DECENT MOISTURE SURGE THOUGH WITH MIXING RATIOS OVER 2 G/KG. GIVEN STEADY...ALBEIT WEAK...ASCENT AND POTENTIAL FOR HIGHER THAN CLIMO SNOW RATIOS...COULD CHURN OUT 1-2" BY LATE MONDAY MORNING. BEST CHANCES FOR HIGHER AMOUNTS WILL BE IN OUR SOUTHWEST WHERE BETTER MOISTURE AND FORCING RESIDE. AFTER A BRIEF BREAK MONDAY NIGHT...THERE IS ANOTHER CHANCE FOR SNOW TUESDAY/TUESDAY NIGHT AS POTENT NORTHERN STREAM SHORTWAVE DIVES SOUTHEAST AND STRENGTHENS EAST COAST LOW. MODELS HAVE BEEN KEEPING PRECIP SHIELD OF PRIMARY LOW JUST EAST OF OUR CWA BUT CONTINUE TO STRUGGLE IMMENSELY WITH EXACT TRACK OF SECONDARY VORT MAX. CONFIDENCE IN SNOW CHANCES REMAINS LOW AT THIS POINT WITH PARENT JET ENERGY STILL WELL OUT OVER THE DATA-SPARSE NORTH PACIFIC. WILL CONTINUE TO WATCH THIS PERIOD AND ADJUST AS MODELS GET A BETTER HANDLE ON SITUATION. SOME MINOR LAKE EFFECT THEN POSSIBLE WEDNESDAY WITH MUCH WARMER TEMPS (AND POTENTIAL FOR RAIN) STILL EXPECTED BY THE END OF THE WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 651 PM EST FRI FEB 12 2016 PRIMARY LAKE SNOW BANDING ALREADY WELL UNDERWAY FROM STONY POINT SWD TO NR SAUGATUCK INLINE W/RAP TRENDS AS LL FLW CONTS TO VEER IN WAKE OF SW PASSAGE. GIVEN GOOD CONTINUITY OF NR TERM MODEL SIGNALS HAVE SHIFTED FWD TIME OF GREATEST IMPACT INVOF OF KSBN AND FULLY XPC A PD OF LIFR CONDS TO MANIFEST AFT 06Z. INLAND REACH OF THIS PRIMARY BAND MAY AFFECT FWA TERMINAL BRIEFLY PRIOR TO 06Z BUT OF QUITE LIMITED DURATION AND LEFT OUT ATTM. WILL AMEND ACCORDINGLY AS NEEDED. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 4 PM EST /3 PM CST/ SATURDAY FOR INZ003>005. MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST SATURDAY FOR MIZ077>079. OH...NONE. LM...HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST SATURDAY FOR LMZ043- 046. GALE WARNING UNTIL 7 AM EST SATURDAY FOR LMZ043-046. && $$ UPDATE...T SYNOPSIS...JT SHORT TERM...JT LONG TERM...AGD AVIATION...T VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
327 PM CST THU FEB 11 2016 .SYNOPSIS... ISSUED AT 327 PM CST THU FEB 11 2016 HIGH PRESSURE CENTERED OVER THE EASTERN CWA THIS AFTERNOON AS LEADING TO CLEAR SKIES AND DRY WEATHER FOR MOST OF THE AREA. A FAST MOVING CLIPPER IS FORECAST TO AFFECT THE AREA LATER TODAY AND TONIGHT AND WILL BE THE MAIN FORECAST CONCERN IN THE SHORT TERM FORECAST. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 327 PM CST THU FEB 11 2016 MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES FOR SNOW ASSOCIATED WITH A FAST CLIPPER ACROSS THE AREA TODAY. DRY AIR IN PLACE WITH THE HIGH OVERHEAD WILL LIMIT OVERALL SNOWFALL TOTALS TO AROUND AN INCH...WITH LOCALLY HIGHER AMOUNTS JUST OVER AN INCH. HIRES GUIDANCE IS IN GOOD AGREEMENT THAT THIS WILL START NEAR 00Z AND BE OUT OF THE AREA BY 08Z. GUIDANCE TODAY HELD STRONG WITH THE CONSENSUS ON TIMING AND STRONGEST FORCING WILL REMAIN ACROSS OUR FAR SOUTHERN ZONES. WWD HAS AROUND AN INCH OF SNOW FOR THIS AREA AND OUR FORECAST REPRESENTS THIS. LATEST RUNS OF THE HRRR SUGGESTS THAT THE BEST SNOW WILL BE OUT OF THE AREA BY 06Z WITH LINGERING FLURRIES THROUGH 09Z ACROSS THE FAR SOUTHERN CWA. WINDS WILL REMAIN LIGHT SO LITTLE TO NO IMPACTS ARE EXPECTED FROM THIS SNOW. ANY SNOW THAT ACCUMULATES SHOULD BE DONE BY THE EARLY HOURS. FRIDAY WILL BE QUIET AND SLIGHTLY WARMER..WITH CLEARING SKIES. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 327 PM CST THU FEB 11 2016 FRIDAY NIGHT...LATEST SUITE OF 12Z RUN MODELS SUGGEST 1045 MB ARCTIC HIGH PRESSURE STILL ON TRACK TO SURGE DOWN THE UPPER TO MID MS RVR VALLEY FRI NIGHT INTO SAT WITH A SCOURING EFFECT. THIS FEATURE TO COLD DUMP LLVL TEMPS/THICKNESS VALUES TO PRODUCE SUB-ZERO LOWS ACRS MOST OF THE CWA...BUT SOME CONCERN THAT ONGOING MIXING SFC WINDS IN INCOMING HIGH PRESSURE GRADIENT TO LIMIT A COMPLETE BOTTOM OUT. BUT DUE TO BRUTE FORCE COLD AIR ADVECTION...WILL STILL GO WITH LOWS FROM 5 TO NEAR 10 BELOW ZERO ACRS THE NORTHWESTERN THIRD OF THE CWA...0 TO 5 BELOW ALONG AND NORTH OF I80...AND TO THE LOW SINGLE DIGITS ABOVE ZERO IN THE SOUTHERN CWA. SFC WINDS DECREASING TO 7-10 MPH TOWARD SUNRISE SAT STILL TO PRODUCE ADVISORY LEVEL WIND CHILLS ACRS AT LEAST THE NORTHWESTERN THIRD OF THE DVN CWA...AND POSSIBLY ALONG THE HWY 20 CORRIDOR IN NW IL. SATURDAY AND SUNDAY...THE ARCTIC HIGH OVERHEAD WILL MAKE FOR TEMPORARY CLEAR AND CALM/LIGHT WIND CONDITIONS FOR FIRST PART OF THE DAY SAT...WITH HIGH CLOUDS ON THE INCREASE AS THE AFTERNOON PROGRESSES. THIS AHEAD OF THE ORGANIZING SHORT WAVE UPPER TROF THAT WILL LOOK TO PROPAGATE TOWARD THE SOUTHWESTERN GRT LKS AND MID MS RVR VALLEY ON SUNDAY IN BROADENING WEST-NORTHWESTERLY STEERING FLOW. THE VARIOUS MEDIUM RANGE SOLUTIONS SUGGEST SOME TYPE OF ASSOCIATED WARM AIR ADVECTION WING OF SNOW WILL LOOK TO TRY TO GET INTO THE WESTERN OR SOUTHWESTERN CWA BY EARLY SAT EVENING...BUT FEEL MODELS MAY BE TOO QUICK WITH THIS TAKING INTO ACCOUNT STRENGTH OF DRY SFC RIDGE AXIS STILL ON THE MOVE OVER AND EAST OF THE CWA AT THAT TIME. BUT BY MIDNIGHT SAT NIGHT...BOTH THE 12Z RUN ECMWF AND GEM SUGGEST SOME LIGHT SNOW ACCUMS STARTING TO TAKE PLACE ALREADY IN THE FAR SOUTHWESTERN CWA. AGAIN SIDING WITH THE 12Z GEM/ECMWF WHICH ARE IN DECENT AGREEMENT...THE WAA WING OF SNOW AHEAD OF THE MAIN UPPER TROF WILL LOOK TO CONTINUE TO SPREAD EASTWARD ACRS MUCH OF THE WESTERN 2/3S OF THE CWA THROUGH 12Z SUNDAY...BUT MAY GET ERODED SOME AS IT DOES BY ONGOING DRY AIR IN PLACE AND ALSO SOME IMPACT OF MUCH OF THE INITIAL LIFT GOING INTO THE TOP-DOWN SATURATION PROCESS. THE LATEST GEM MAY HAVE THE BEST HANDLE ON THIS IDEA WITH JUST A DUSTING TO HALF INCH WEST OF THE MS RVR BY 12Z SUNDAY...BUT WILL GO WITH A FEW TENTHS TO NEAR AN INCH SOUTHWEST OF A LINE FROM DBQ...TO THE QUAD CITIES...AND TO MACOMB IN WESTERN IL. THEN THE MAIN SNOW EVENT WITH THE UPPER TROF WILL LOOK TO OCCUR ON SUNDAY AND WILL CONTINUE TO ADJUST POPS UP INTO LIKELY OR EVEN CATEGORICAL. BUT THE 12Z RUN AMERICAN MODELS/ESPECIALLY THE 12Z GFS/ WHICH HINT AT HIGH END ADVISORY OR EVEN LOW END WARNING CRITERIA AMOUNT SNOWS BY SUNDAY EVENING COMBINING THE TWO SNOW MAKING PROCESSES...SEEM TOO WET...TOO STRONG LOOKING AT MID AND UPPER LEVEL JET DYNAMICS MORE FAVORABLE TO THE SOUTH...AND THEIR DEEP SATURATION IN THE DENDRITIC GROWTH ZONE FOR MUCH OF SUNDAY MORNING INTO EARLY AFTERNOON. SO CURRENTLY FAVOR A BLEND OF THE 12Z GEM/ECMWF MOISTURE AND FORCING PROFILES WHICH SUGGEST MOST OF THE CWA TO GET 1-3 OR 2-4 INCHES OF SNOW BY SUNDAY EVENING. INCREASING SOUTH WINDS OF 15-20 MPH MAY PRODUCE SOME DRIFTING TROUBLE BY SUNDAY AFTERNOON AS WELL...SO THERE MAY BE A NEED FOR AN EVENTUAL ADVISORY EVEN WITH THE LIGHTER AMOUNTS PRODUCED BY THESE FAVORED SOLUTIONS. STILL 1-3 MORE MODEL RUNS NEEDED TO FURTHER DEFINE THIS SNOW EVENT FOR MORE CONFIDENCE. MONDAY THROUGH NEXT THU...AS THE PASSING TROF CONTINUES TO EVOLVE ALONG AND EAST OF THE REGION EARLY NEXT WEEK..RESULTANT MAJOR STORM SHOULD TAKE OFF WELL TO THE EAST/SOUTHEAST OF LOCAL AREA OF CONCERN. BUT THERE MAY BE SOME NUISANCE LIGHT SNOW AT TIMES ACRS THE AREA IN THE WAKE OF THE MAIN SYSTEM...OR EVEN A SECONDARY WEAK CLIPPER LATE MONDAY INTO TUE. LONGER RANGE INDICATIONS THEN SUGGEST THE CLIPPER INDUCING NORTHWESTERLIES WILL EVENTUALLY GIVE WAY TO MILDER UPPER RIDGING BY MID TO LATE NEXT WEEK...BUT THE TREND HAS BEEN TO DELAY IT/S ARRIVAL ESPECIALLY IF RE-ENFORCING TROFFINESS ESTABLISHES ACRS THE WESTERN GRT LKS TUE INTO WED LIKE SOME OF THE LATEST ENSEMBLES SUGGEST. ..12.. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1132 AM CST THU FEB 11 2016 VFR CONDITIONS GIVING WAY TO MVFR CIGS AND POSSIBLY IFR VSBYS DURING SNOW LATE THIS AFTERNOON AND THROUGH THE EVENING IS EXPECTED AT MOST TAF SITES. BRL HAS THE BEST CHANCE FOR SNOW. OTHERWISE WINDS SHOULD TURN TO THE SW AND THEN THE WNW LATE IN THE PERIOD INTO TOMORROW WHERE SOME STRONG SUSTAINED WINDS ARE POSSIBLE WITH GUSTS POSSIBLY TO 25KT. VFR CONDITIONS SHOULD RETURN BY 09Z AT MOST TAF SITES. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...12 AVIATION...GIBBS
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1119 AM CST THU FEB 11 2016 ...Updated for Aviation... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM CST THU FEB 11 2016 High pressure sinking south through the plains states will affect temperatures to the negative side over the next couple of days. Stratus was advancing across the Missouri valley into central Nebraska and northern Kansas. The latest HRRR model runs have continued to advect stratus of around 1000ft bases through the Hays area and perhaps as far south as Dodge City after 12 UTC. So stratus dissipation and local visibilities due to fog may be the main forecast problems of the morning influencing temperature trends. Afternoon highs will be not as warm today, however drier dew points and downslope trajectories should still help temperatures warm toward 70 in the far west. .LONG TERM...(Friday THROUGH Wednesday) ISSUED AT 346 AM CST THU FEB 11 2016 Very low precipitation probabilities were included associated with mainly a freezing drizzle and fog possibility on Friday night into very early Saturday morning, however, this only glances the northwest most sections of west central Kansas as the model signal is focused over the northwest part of the state. A general cooling trend each day ends by Sunday as the easterly surface wind gets whipped around from the west once again as a shortwave dives through the Northern Plains. A short period of weakly cyclonic flow aloft will continue into the Monday timeframe and pops may need to be revisited in the coming forecast cycles, but at this point the confidence is extremely low for precipitation chances. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON) ISSUED AT 1113 AM CST THU FEB 11 2016 Some low stratus at KHYS is forecast to dissipate early this afternoon, then reform early Friday am after 12Z as wind shifts back to the light north-northeast. Elsewhere expect VFR with light south to southwest winds shifting northwesterly at 5-12kt after 00-03Z as a weak surface trough moves across western Kansas. && .PRELIMINARY POINT TEMPS/POPS... DDC 57 31 51 22 / 0 0 0 10 GCK 61 29 53 24 / 0 0 0 10 EHA 67 33 59 29 / 0 0 0 10 LBL 63 31 58 26 / 0 0 0 10 HYS 49 30 42 20 / 0 0 0 20 P28 54 32 52 22 / 0 0 0 10 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Kruse
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
541 AM CST THU FEB 11 2016 ...Updated aviation discussion... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM CST THU FEB 11 2016 High pressure sinking south through the plains states will affect temperatures to the negative side over the next couple of days. Stratus was advancing across the Missouri valley into central Nebraska and northern Kansas. The latest HRRR model runs have continued to advect stratus of around 1000ft bases through the Hays area and perhaps as far south as Dodge City after 12 UTC. So stratus dissipation and local visibilities due to fog may be the main forecast problems of the morning influencing temperature trends. Afternoon highs will be not as warm today, however drier dew points and downslope trajectories should still help temperatures warm toward 70 in the far west. .LONG TERM...(Friday THROUGH Wednesday) ISSUED AT 346 AM CST THU FEB 11 2016 Very low precipitation probabilities were included associated with mainly a freezing drizzle and fog possibility on Friday night into very early Saturday morning, however, this only glances the northwest most sections of west central Kansas as the model signal is focused over the northwest part of the state. A general cooling trend each day ends by Sunday as the easterly surface wind gets whipped around from the west once again as a shortwave dives through the Northern Plains. A short period of weakly cyclonic flow aloft will continue into the Monday timeframe and pops may need to be revisited in the coming forecast cycles, but at this point the confidence is extremely low for precipitation chances. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING) ISSUED AT 541 AM CST THU FEB 11 2016 IFR stratus is currently spreading south toward central Kansas. It should be moving into the Hays area shortly after the beginning of this TAF issuance. The stratus should impact operations through the morning hours but should erode east of the area by midday. Do not see the stratus moving too much more to the southwest so Garden City and Dodge City should remain VFR. && .PRELIMINARY POINT TEMPS/POPS... DDC 57 31 51 22 / 0 0 0 10 GCK 61 29 53 24 / 0 0 0 10 EHA 66 33 59 29 / 0 0 0 10 LBL 62 31 58 26 / 0 0 0 10 HYS 49 30 42 20 / 0 0 0 20 P28 54 32 52 22 / 0 0 0 10 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Gerard
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
348 AM CST THU FEB 11 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM CST THU FEB 11 2016 High pressure sinking south through the plains states will affect temperatures to the negative side over the next couple of days. Stratus was advancing across the Missouri valley into central Nebraska and northern Kansas. The latest HRRR model runs have continued to advect stratus of around 1000ft bases through the Hays area and perhaps as far south as Dodge City after 12 UTC. So stratus dissipation and local visibilities due to fog may be the main forecast problems of the morning influencing temperature trends. Afternoon highs will be not as warm today, however drier dew points and downslope trajectories should still help temperatures warm toward 70 in the far west. .LONG TERM...(Friday THROUGH Wednesday) ISSUED AT 346 AM CST THU FEB 11 2016 Very low precipitation probabilities were included associated with mainly a freezing drizzle and fog possibility on Friday night into very early Saturday morning, however, this only glances the northwest most sections of west central Kansas as the model signal is focused over the northwest part of the state. A general cooling trend each day ends by Sunday as the easterly surface wind gets whipped around from the west once again as a shortwave dives through the Northern Plains. A short period of weakly cyclonic flow aloft will continue into the Monday timeframe and pops may need to be revisited in the coming forecast cycles, but at this point the confidence is extremely low for precipitation chances. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Thursday NIGHT) ISSUED AT 1134 PM CST WED FEB 10 2016 VFR category is forecast with fairly high confidence at GCK. However IFR category may be possible at HAYS toward the 11-14Z timeframe as the cooler airmass over the Missouri valley advects stratus clouds westward. Winds remain light through the period. && .PRELIMINARY POINT TEMPS/POPS... DDC 57 31 51 22 / 0 0 0 10 GCK 61 29 53 24 / 0 0 0 10 EHA 66 33 59 29 / 0 0 0 10 LBL 62 31 58 26 / 0 0 0 10 HYS 49 30 42 20 / 0 0 0 20 P28 54 32 52 22 / 0 0 0 10 && .DDC Watches/Warnings/Advisories...NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Russell
AREA FORECAST DISCUSSION
NWS GRAY ME
1024 PM EST FRI FEB 12 2016 .SYNOPSIS... AN ARCTIC COLD FRONT WILL CROSS THE REGION TONIGHT THROUGH SATURDAY USHERING IN THE COLDEST AIRMASS OF THE SEASON THUS FAR. AS THIS COLD AIR INTERACTS WITH A TROUGH OF LOW PRESSURE OVER THE GULF OF MAINE...A PERIOD OF MODERATE TO HEAVY SNOW WILL BE POSSIBLE ALONG THE MIDCOAST REGION OF MAINE. BEYOND THIS...THE COMBINATION OF COLD TEMPERATURES AND STRONG NORTHWEST WINDS WILL CAUSE DANGEROUSLY COLD WIND CHILLS SATURDAY NIGHT AND SUNDAY. TEMPERATURES WILL RAPIDLY MODERATE NEXT WEEK WITH A WINTRY MIX OF PRECIPITATION POTENTIALLY TRANSITIONING TO RAIN ON MONDAY NIGHT AND TUESDAY ALONG WITH STRONG SOUTHERLY WINDS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 1015 PM UPDATE...HAVE MADE THE TRANSITION TO WINTER STORM WARNINGS AND ADVISORIES FOR THE MID COAST OF MAINE BASED ON THE LATEST SREF...NAM...4 KM NAM...HRRR...AND RAP. MUCH IF NOT ALL OF THE EVENING GUIDANCE HAS SHIFTED TO THE SOUTHWEST WITH THE AXIS OF THE NORLUN TROF AND SUBSEQUENT HEAVY SNOW BAND. THERE IS STILL CONSIDERABLE UNCERTAINTY AS THERE ALWAYS IS RIGHT UP TO THE BUZZER WITH THESE MESOSCALE FEATURES. HOWEVER...BASED ON A BLEND OF GUIDANCE THAT REFLECTS A REAL SW TREND...FELT CONFIDENT ENOUGH TO SHIFT THE SNOW AXIS SOUTHWESTWARD AS WELL. THE RESULT IS A WINTER STORM WARNING FOR COASTAL WALDO AND KNOX COUNTIES. A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR INTERIOR WALDO AND LINCOLN COUNTIES. AGAIN...CONSIDERABLE UNCERTAINTY REMAINS...AND THERE IS EVEN SOME CHANCE THAT THE HEAVIEST SNOW REMAINS ON THE PENINSULAS AND ISLANDS...AND PERHAPS EVEN FURTHER EAST THAN THAT. IF IT APPEARS AS THOUGH THE HEAVIEST SNOW WILL SHIFT FURTHER NORTH AND WEST...THE ADVISORIES COULD BE UPGRADED TO WARNINGS. 635 PM UPDATE...HAVE CONTINUED TO POUR OVER LATEST OBERVATIONAL AND MESOSCALE MODEL DATA EARLY THIS EVENING TO TRY AND PIN DOWN THE FORMATION AND MOVEMENT OF AN INVERTED TROF THAT MAY BRING HEAVY SNOWFALL TO A PORTION OF THE MID COAST. UNFORTUNATELY AT THIS TIME IT IS A LITTLE TO EARLY TO SEE ANYTHING SIGNIFICANT IN THE LATEST OBSERVATIONAL DATA SUCH AS BUOYS AND RADAR. AS FAR AS THE MESOSCALE MODELS GO...THERE IS STILL A LOT OF SPREAD IN WHERE THIS BAND WILL /OR WILL NOT/ DEVELOP OVER LAND. THE LATEST RUNS OF THE NAM AND RGEM AS WELL AS THE 2.5 KM CANADIAN HIT KNOX AND WALDO COUNTIES PRETTY HARD. HOWEVER...THE LATEST RUNS OF THE HRRR AND RAP KEEP MUCH OF THE ACCUMULATING SNOWFALL OFFSHORE EXCEPT PERHAPS THE PENINSULAS AND ISLANDS OF THE MID COAST. WITH SO MUCH UNCERTAINTY REMAINING AND NO SIGN OF DEVELOPMENT YET IN OBSERVATIONAL DATA...CAN/T REALLY JUSTIFY A WINTER STORM WARNING. WILL HOLD ONTO THE WATCH FOR A FEW MORE HOURS. WILL LIKELY MAKE A DECISION BY 10 PM...AND IF THERE IS STILL A LOT OF UNCERAINTY BY THEN WE MAY JUST GO WITH AN ADVISORY AND LET THE NEXT SHIFT UPGRADE TO A WARNING IF NEED BE. PREVIOUSLY... HIGH IMPACT WEATHER POTENTIAL: SNOW DEVELOPS ALONG THE MIDCOAST OVERNIGHT. CURRENT PATTERN: EARLY AFTERNOON WATER VAPOR IMAGERY REVEALS RIDGE- TROUGH PATTERN ACROSS THE CONUS...WITH IMPRESSIVE PORTION OF THE POLAR VORTEX CURRENTLY CENTERED OVER JAMES BAY. SOUTH OF THIS FEATURE...WATER VAPOR IMAGERY DEFINES A DIGGING SHORTWAVE /DARKENING OF THE IMAGERY/ OVER THE NORTHERN OHIO VALLEY. THIS WILL HELP FORCE CYCLOGENESIS OFF THE MID ATLANTIC COAST THAT WILL RACE NORTHEAST WELL SOUTH AND EAST OF NEW ENGLAND THROUGH SATURDAY. A WEAKER SURFACE LOW IS CURRENTLY DEPICTED OVER THE EASTERN GREAT LAKES ASSOCIATED WITH FORCING AHEAD OF THE H5 LOW OVER JAMES BAY. AS THIS LATTER FEATURE DIVES SOUTH AND EAST TOWARDS NEW ENGLAND THIS WEEKEND...THE ASSOCIATED SURFACE LOW WILL BE ABSORBED INTO THE DEVELOPING SYSTEM OFFSHORE. OUR PRIMARY WEATHER IMPACTS WILL BE 1- WHAT HAPPENS BETWEEN THESE SYSTEMS AS IMPRESSIVE MID AND UPPER LEVEL FORCING COMBINES WITH VERY SUBSTANTIAL INSTABILITY OVER THE RELATIVELY WARM GULF OF MAINE WATERS AND 2- THE RAMIFICATIONS OF ARRIVING ARCTIC AIR. TEMPS AT H8 THIS MORNING WERE -35C OVER JAMES BAY WITH TEMPERATURES CLOSE TO THIS REACHING NEW ENGLAND ON SATURDAY...PRESENTING WIND CHILL CONCERNS AS IMPRESSIVE COLD ADVECTION DRIVES THIS AIR INTO THE REGION. TONIGHT: EXPECT A GENERAL INCREASE IN MID AND UPPER LEVEL CLOUDINESS PER A LOOK AT AFTERNOON VISIBLE SATELLITE IMAGERY AS WEAK WARM ADVECTION CONTINUES AHEAD OF APPROACHING SURFACE LOW NOW NORTH OF LAKE ONTARIO. FORCING FOR ASCENT WILL BE ON THE INCREASE WITH TOP DOWN SATURATION LIKELY BRINGING SNOW SHOWER ACTIVITY INTO THE MOUNTAINS OVERNIGHT. WE/LL TALK MORE ABOUT THE NORLUN EVENT IN THE SHORT TERM SECTION BELOW...BUT EXPERIMENTAL HRRR IS ON BOARD WITH THE 12Z GUIDANCE SUITE IN DEVELOPING LLEVEL CONVERGENCE IN THE VICINITY OF PENOBSCOT BAY BY MIDNIGHT TONIGHT...WITH SNOW DEVELOPING IN THIS REGION AND CONTINUING THROUGH THE MORNING. WITH A GOOD FLUFF FACTOR HELPING ACCUMULATIONS...COULD SEE 1-3 INCHES OVER KNOX/WALDO COUNTIES BY DAYBREAK. TEMPERATURES: WITH SOUTHWEST FLOW ONGOING AND CLOUDS ON THE INCREASE...TEMPERATURES WILL BE A GOOD BIT WARMER THAN THE PREVIOUS NIGHT BUT GIVEN THE CHILLY HIGHS OF TODAY...WILL CERTAINLY NOT BE WARM. EXPECT LOWS IN THE SINGLE DIGITS IN THE MOUNTAINS THROUGH THE LOWER TEENS ALONG THE COAST. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... SIGNIFICANT SNOW ALONG THE MID COAST BECOMING INCREASINGLY LIKELY SATURDAY... DANGEROUSLY COLD WIND CHILLS SATURDAY NIGHT THROUGHOUT THE REGION... HIGH IMPACT WEATHER POTENTIAL: HEAVY SNOW TOTALS POSSIBLE IN THE VICINITY OF PENOBSCOT BAY SATURDAY WITH ATTENTION THEN TURNING TO ADVISORY-WARNING LEVEL WIND CHILLS SATURDAY NIGHT. SATURDAY: CORE OF H5 LOW ALOFT SINKS FROM JAMES BAY AT DAYBREAK SOUTH AND EAST INTO NORTHERN NEW ENGLAND TOWARDS EVENING WITH T8S NEARING -30C OVER MY WESTERN ZONES BY 00Z/SUN. COL REGION BETWEEN LOW LEVEL REFLECTION OF THIS H5 LOW AND THE DEVELOPING SYSTEM WELL SOUTH AND EAST OF THE BENCHMARK APPEARS TO BE ALLOWING ALL THE INGREDIENTS FOR A BONA-FIDE NORLUN EVENT TO BE PRESENT AS THE H8 FLOW GOES SLACK ALONG WITH A DEVELOPING LLEVEL CONVERGENCE ZONE. THERE WILL BE AMPLE INSTABILITY IN THE LLEVELS WITH WATER SURFACE TO H8 DELTA TS NEAR -15 AND DELTA TS TO H7 NEARING -30C. THIS ALLOWS FOR A TREMENDOUS AMOUNT OF LLEVEL INSTABILITY...WITH OCEAN-INDUCED CAPE VALUES OF 500-1000 J/KG PORTRAYED ON THE 12Z NAM AND GFS. THIS COULD VERY WELL PROMOTE THUNDER WITH ANY SNOW BAND THAT DOES DEVELOP. SNOW RATIOS: THE DENDRITIC GROWTH ZONE WILL BE BELOW THE PRIMARY AREA OF LIFT DURING THE HEIGHT OF THE EVENT...BUT IT WILL STILL GET CLIPPED AND SEE NO REASON WHY WE CAN/T FORCE 15-20:1 RATIOS OUT OF THIS SETUP. THERE IS UNCANNY AGREEMENT IN THE 12Z SUITE /NAM-GFS-ECMWF-GEM/ ON THE PLACEMENT OF THE MESOSCALE BAND OVER PENOBSCOT BAY. WHILE THIS WOULD TEND TO SUGGEST ABOVE NORMAL CONFIDENCE...THE FACT THAT THIS IS A NORLUN EVENT BEGS CAUTION. A LOOK A THE 00Z NCAR ENSEMBLE SHOWS ABOUT 40% OF THE MEMBERS DIRECTLY IMPACTING OUR AREA. WOULD REALLY LIKE TO SEE THIS EVENT COME INTO THE NEAR TERM-HIGH RESOLUTION GUIDANCE WINDOW AND AS SUCH...WITH THE WORD OUT RIGHT NOW WITH THE WATCH...WILL LET THE EVENING SHIFT TAKE A FINAL LOOK AT THINGS BEFORE MAKING A FINAL DECISION ON WINTER STORM WARNINGS VS. WINTER WEATHER ADVISORIES. THAT BEING SAID...CERTAINLY CANNOT RULE OUT SOME 1 FOOT+ SNOWFALL AMOUNTS SOMEWHERE IN THE MID COAST REGION GIVEN THE SETUP ABOVE. TEMPERATURES: MAY RISE SLIGHTLY IN THE EARLY MORNING...BUT WILL THEN REVERSE COURSE AND FALL THROUGH THE AFTERNOON WITH ALL LOCATIONS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO BY EVENING. WIND CHILLS WILL REACH ADVISORY LEVELS IN THE MOUNTAINS IN THE AFTERNOON...WITH THE MOST DANGEROUS VALUES HOLDING OFF UNTIL SATURDAY NIGHT. NONETHELESS...WIND CHILLS WILL BECOME INCREASINGLY DANGEROUS BY LATE AFTERNOON/EVENING. WINDS: VERY IMPRESSIVE COLD AIR ADVECTION WILL YIELD STEEP LLEVEL LAPSE RATES...WHICH SHOULD BE ABLE TO MIX ANYTHING THE ATMOSPHERE HAS TO OFFER WIND-WISE IN THE LOWEST 5KFT. HIGHEST WINDS IN THE COLUMN ARE AROUND 30KTS /A BIT HIGHER OFFSHORE/ SO WILL PAINT GUSTS AROUND 30MPH INLAND /HIGHER ON THE HILLTOPS/ AND 30-40MPH ALONG THE COAST. NOTE: WINDS WILL NOT BE THIS STRONG IN THE VICINITY OF THE NORLUN TROUGH AND THUS SIGNIFICANT BLOWING/DRIFTING WILL NOT INITIALLY BE A PROBLEM. HOWEVER...BY SATURDAY EVENING...THERE WILL LIKELY BE SIGNIFICANT BLOWING/DRIFTING...AND WILL HAVE TO WATCH FOR THIS IF THE SNOW DOES MATERIALIZE. SATURDAY NIGHT: H5 LOW OPENS UP AND SHIFTS EAST WITH THE CORE OF THE COLDEST AIR ALOFT OVERHEAD UNDER CONTINUED STRONG NORTHWEST WINDS AS GRADIENT BETWEEN 1035 MB HIGH OVER THE GREAT LAKES COMBINES WITH OFFSHORE-MOVING NORLUN TO CONTINUE WINDS OF 15G25KTS. CONCERNS WILL TURN TO DANGEROUSLY COLD WIND CHILLS...WHICH SHOULD HAVE NO PROBLEM HITTING WARNING CRITERIA IN THE MOUNTAINS AND FOOTHILLS...BUT LIKELY REMAIN AT ADVISORY LEVELS ALONG THE COAST. AM HONESTLY A BIT SURPRISED IN THE MET/MAV LOW TEMPERATURE SPREAD AS WE SHOULD REMAIN WELL-MIXED THROUGH THE NIGHT. DID GIVE SOME NOD TO THE COLDER MET...WITH LOWS BELOW ZERO IN ALL LOCATIONS...AND PERHAPS AS LOW AS -20 IN THE MOUNTAINS. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HIGH IMPACT WEATHER: DANGEROUSLY COLD WIND CHILLS LINGER INTO AT LEAST SUNDAY MORNING. A STORM COULD BRING SNOW/FREEZING RAIN/RAIN TO THE REGION MONDAY NIGHT INTO TUESDAY NIGHT. STRONG WINDS ARE POSSIBLE WITH THIS SYSTEM AS WELL. DEEP PERSISTENT 500 TROUGH OVER THE ERN CONUS ON SUNDAY WILL SHIFT NE AND WEAKEN BY EARLY NEXT WEEK...AND THIS ALLOWS THE HEMISPHERIC WAVE PATTERN TO BECOME LESS AMPLIFIED WITH A HIGHER WAVE NUMBER. THE OVERALL +PNA PATTERN WEAKENS EARLY TO MID-WEEK...AND TRIES TO BREAK DOWN BY THE END OF THE WEEK. OF NOTE THOUGH...IS SRN STREAM WAVE THAT DIGS OVER S CENTRAL CONUS MON AND LIFTS NWD TUE AND WED AS NRN STREAM DIVES INTO IT AND THIS COULD PRODUCE THE HIGH IMPACT STORM OVER NEW ENGLAND AROUND TUESDAY. SUNDAY START IN THE THROES OF THE THE VERY COLD AIR MASS IN THE REGION WITH STRONG PRES GRAD IN PLACE AND GUSTY NW WINDS. THE DANGEROUS WIND CHILLS LINGER THRU THE MORNING BUT AS TEMPS WARM FROM LOWS BELOW ZERO EVERYWHERE...AND WITH PRES GRADIENT SLACKENING AS SFC HIGH BUILDS IN SHOULD SEE WIND CHILLS RISE TO MORE BEARABLE LVLS BY AFTERNOON. STILL...THE TAIL OF THE CAA WILL HOLD THRU MOST OF THE DAY AND HIGHS WILL STRUGGLE TO REACH ZERO IN THE N...AND TO REACH 10F IN THE SOUTH. AS THE SFC HIGH MOVES OVER THE REGION LOOK FOR DECOUPLING IN MOST PLACES AND VERY GIVEN GOOD RAD COOLING GIVEN COLD AIR IN PLACE AND A STARTING POINT NEAR OR BELOW ZERO. WENT BELOW SUPERBLEND FOR MINS IN MOST PLACES...AND SIGNIFICANTLY BELOW IN THE MORE SHELTERED SPOTS. THIS SHOULD BRINGUS LOWS 10 BELOW TO ZERO IN THE COASTAL PLAIN...WITH LOWS DROPPING TO -20 OR LOWER IN THE SHELTERED MOUNTAIN VALLEYS. ON MONDAY LOOK FOR WARMER AIR TO START WORKING IN...AND HIGHS REBOUND INTO THE TEENS TO MID 20S...WITH INCREASING CLOUDS IN THE AFTERNOON. THE NEXT SYSTEM MOVES IN ON MON NIGHT AND TUE. SOME DIFFERENCES IN THE MODEL AS TO HAVE FAR W THE SFC LOW TRACKS...WITH THE GFS AND GGEM PASSING IT S-N THRU THE MIDDLE OF ME...AND THE EURO AND GEFS MEAN BRINGING IT NWD ALONG THE NY/VT BORDER...WHICH WOULD BE THE WARMER SOLN...AND LIKELY LEAD TO SNOW TO FZRA/PL TO RAIN SOLN IN MANY SPOTS. THE MORE EASTERLY TRACK WOULD SEE SNOW LAST LONGER INTO THE STORM AWAY FROM THE COAST. P-TYPE WILL BE ONE OF THE BIG ISSUES WITH THIS SYSTEM AND CONFIDENCE IS LOW AS TO HOW IT WILL ALL UNFOLD. ONE THING TO NOTE IS THAT WE ARE COMING OUT OF VERY COLD AIRMASS...AND DESPITE THE BEST WINDS ABOVE THE INVERSION IT WILL BE SLOW TO BREAK OUT OF THAT LOW LVL COLD AIR...WHICH WILL PROBABLY HOLD ON LONGER THAN THE MODELS SUGGEST. ANOTHER ISSUE COULD BE STRONG WINDS...ALTHOUGH WITH THE INVERSION MAY BE TOUGH FOR THOSE WINDS TO MIX TO THE SFC...AT LEAST FOR ANY SIGNIFICANT LENGTH OF TIME. THE WHOLE SYSTEM WILL MOVE OUT LATE TUE NIGHT AND WED. COULD BUST OUT INTO WARMER AIR ON WED BEHIND THE SYSTEM WITH HIGHS CLIMBING INTO THE UPPER 30S TO LOW 40S. COLD FRONT SWINGS THRU WED NIGHT WITH UPPER LVL TROUGH ON THU AND TEMPS DROP BACK AGAIN...BELOW NORMAL...BUT NOT TOO FAR...WITH HIGHS IN THE 20S TO AROUND 30. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM...VFR UNDER MOSTLY CLEAR CONDITIONS ATTM. EXPECT DETERIORATING CONDITIONS THROUGH THE COMING TAF PERIOD WITH SNOW DEVELOPING OVERNIGHT AT RKD AND LIKELY AUG WITH IFR/LIFR RESTRICTIONS. FOR A PERIOD SATURDAY...INCH PER HOUR SNOWFALL RATES ARE POSSIBLE...MOST LIKELY AT RKD. FURTHER WEST...ARCTIC FRONT WILL BRING A ROUND OF SNOW SHOWERS...MOST LIKELY TO BRING RESTRICTIONS TO LEB/HIE...BUT BRIEF RESTRICTIONS ARE POSSIBLE SOUTH AND EAST OF THIS AS WELL. CONDITIONS IMPROVE SATURDAY NIGHT WITH VFR CONDITIONS RETURNING FOR SUNDAY. AFTER LIGHT WINDS OVERNIGHT...STRONG NORTHWEST WINDS /15G25KTS/ WILL DEVELOP BY LATE MORNING SATURDAY AND CONTINUE THROUGH SATURDAY NIGHT. LONG TERM...MAINLY VFR SUN THRU MON WITH GUSTY NW WINDS DIMINISHING DURING SUN AFTERNOON. COULD SEE EXTENDED PERIOD OF IFR OR LOWER IN SN/FZRA/RA MON NIGHT INTO TUE NIGHT. && .MARINE... SHORT TERM...WINDS/WAVES BELOW SMALL CRAFT LEVELS INTO TOMORROW MORNING BEFORE INTENSE COLD ADVECTION BEHIND AN ARCTIC COLD FRONT BRINGS A PERIOD OF GALES TO THE OUTER WATERS BY LATE SATURDAY AFTERNOON THROUGH SUNDAY MORNING WITH WINDS LIKELY REMAINING BELOW GALE FORCE IN THE BAYS. IN ADDITION...HEAVY FREEZING SPRAY WARNINGS HAVE BEEN HOISTED SATURDAY EVENING THROUGH SUNDAY MORNING GIVEN THE COMBINATION OF THE AFOREMENTIONED WINDS AND THE COLDEST AIRMASS OF THE SEASON THUS FAR. LONG TERM...NW WIND DIMINISH SLOWLY THRU SUNDAY...AS DOES INTENSITY OF FREEZING SPRAY...BUT WILL LKLY HOLD TO SCA WINDS THRU SUN EVE. AFTER A BRIEF BREAK IN THE WINDS ON MON AND MON NIGHT...LOOK FOR S WINDS TO REACH SCA LVLS EARLY TUE AND COULD REACH GALES BY TUE AFTERNOON AND EVE...BEFORE DIMINISHING WED. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...WIND CHILL WARNING FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR MEZ012>014-018>022. WIND CHILL WARNING FROM 7 PM SATURDAY TO 10 AM EST SUNDAY FOR MEZ007>009. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST SATURDAY NIGHT FOR MEZ022-026. WIND CHILL ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR MEZ023>028. WINTER STORM WARNING UNTIL MIDNIGHT EST SATURDAY NIGHT FOR MEZ027-028. NH...WIND CHILL WARNING FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR NHZ004>013-015. WIND CHILL WARNING FROM 7 PM SATURDAY TO 10 AM EST SUNDAY FOR NHZ001>003. WIND CHILL ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR NHZ014. MARINE...HEAVY FREEZING SPRAY WARNING FROM 7 PM SATURDAY TO NOON EST SUNDAY FOR ANZ150>154. SMALL CRAFT ADVISORY FROM NOON SATURDAY TO NOON EST SUNDAY FOR ANZ151-153. GALE WARNING FROM 4 PM SATURDAY TO NOON EST SUNDAY FOR ANZ150- 152-154. && $$ NEAR TERM UPDATE...EKSTER SHORT TERM...ARNOTT LONG TERM...CEMPA AVIATION...ARNOTT/CEMPA MARINE...ARNOTT/CEMPA
AREA FORECAST DISCUSSION
NWS GRAY ME
645 PM EST FRI FEB 12 2016 .SYNOPSIS... AN ARCTIC COLD FRONT WILL CROSS THE REGION TONIGHT THROUGH SATURDAY USHERING IN THE COLDEST AIRMASS OF THE SEASON THUS FAR. AS THIS COLD AIR INTERACTS WITH A TROUGH OF LOW PRESSURE OVER THE GULF OF MAINE...A PERIOD OF MODERATE TO HEAVY SNOW WILL BE POSSIBLE ALONG THE MIDCOAST REGION OF MAINE. BEYOND THIS...THE COMBINATION OF COLD TEMPERATURES AND STRONG NORTHWEST WINDS WILL CAUSE DANGEROUSLY COLD WIND CHILLS SATURDAY NIGHT AND SUNDAY. TEMPERATURES WILL RAPIDLY MODERATE NEXT WEEK WITH A WINTRY MIX OF PRECIPITATION POTENTIALLY TRANSITIONING TO RAIN ON MONDAY NIGHT AND TUESDAY ALONG WITH STRONG SOUTHERLY WINDS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 635 PM UPDATE...HAVE CONTINUED TO POUR OVER LATEST OBERVATIONAL AND MESOSCALE MODEL DATA EARLY THIS EVENING TO TRY AND PIN DOWN THE FORMATION AND MOVEMENT OF AN INVERTED TROF THAT MAY BRING HEAVY SNOWFALL TO A PORTION OF THE MID COAST. UNFORTUNATELY AT THIS TIME IT IS A LITTLE TO EARLY TO SEE ANYTHING SIGNIFICANT IN THE LATEST OBSERVATIONAL DATA SUCH AS BUOYS AND RADAR. AS FAR AS THE MESOSCALE MODELS GO...THERE IS STILL A LOT OF SPREAD IN WHERE THIS BAND WILL /OR WILL NOT/ DEVELOP OVER LAND. THE LATEST RUNS OF THE NAM AND RGEM AS WELL AS THE 2.5 KM CANADIAN HIT KNOX AND WALDO COUNTIES PRETTY HARD. HOWEVER...THE LATEST RUNS OF THE HRRR AND RAP KEEP MUCH OF THE ACCUMULATING SNOWFALL OFFSHORE EXCEPT PERHAPS THE PENINSULAS AND ISLANDS OF THE MID COAST. WITH SO MUCH UNCERTAINTY REMAINING AND NO SIGN OF DEVELOPMENT YET IN OBSERVATIONAL DATA...CAN/T REALLY JUSTIFY A WINTER STORM WARNING. WILL HOLD ONTO THE WATCH FOR A FEW MORE HOURS. WILL LIKELY MAKE A DECISION BY 10 PM...AND IF THERE IS STILL A LOT OF UNCERAINTY BY THEN WE MAY JUST GO WITH AN ADVISORY AND LET THE NEXT SHIFT UPGRADE TO A WARNING IF NEED BE. PREVIOUSLY... HIGH IMPACT WEATHER POTENTIAL: SNOW DEVELOPS ALONG THE MIDCOAST OVERNIGHT. CURRENT PATTERN: EARLY AFTERNOON WATER VAPOR IMAGERY REVEALS RIDGE- TROUGH PATTERN ACROSS THE CONUS...WITH IMPRESSIVE PORTION OF THE POLAR VORTEX CURRENTLY CENTERED OVER JAMES BAY. SOUTH OF THIS FEATURE...WATER VAPOR IMAGERY DEFINES A DIGGING SHORTWAVE /DARKENING OF THE IMAGERY/ OVER THE NORTHERN OHIO VALLEY. THIS WILL HELP FORCE CYCLOGENESIS OFF THE MID ATLANTIC COAST THAT WILL RACE NORTHEAST WELL SOUTH AND EAST OF NEW ENGLAND THROUGH SATURDAY. A WEAKER SURFACE LOW IS CURRENTLY DEPICTED OVER THE EASTERN GREAT LAKES ASSOCIATED WITH FORCING AHEAD OF THE H5 LOW OVER JAMES BAY. AS THIS LATTER FEATURE DIVES SOUTH AND EAST TOWARDS NEW ENGLAND THIS WEEKEND...THE ASSOCIATED SURFACE LOW WILL BE ABSORBED INTO THE DEVELOPING SYSTEM OFFSHORE. OUR PRIMARY WEATHER IMPACTS WILL BE 1- WHAT HAPPENS BETWEEN THESE SYSTEMS AS IMPRESSIVE MID AND UPPER LEVEL FORCING COMBINES WITH VERY SUBSTANTIAL INSTABILITY OVER THE RELATIVELY WARM GULF OF MAINE WATERS AND 2- THE RAMIFICATIONS OF ARRIVING ARCTIC AIR. TEMPS AT H8 THIS MORNING WERE -35C OVER JAMES BAY WITH TEMPERATURES CLOSE TO THIS REACHING NEW ENGLAND ON SATURDAY...PRESENTING WIND CHILL CONCERNS AS IMPRESSIVE COLD ADVECTION DRIVES THIS AIR INTO THE REGION. TONIGHT: EXPECT A GENERAL INCREASE IN MID AND UPPER LEVEL CLOUDINESS PER A LOOK AT AFTERNOON VISIBLE SATELLITE IMAGERY AS WEAK WARM ADVECTION CONTINUES AHEAD OF APPROACHING SURFACE LOW NOW NORTH OF LAKE ONTARIO. FORCING FOR ASCENT WILL BE ON THE INCREASE WITH TOP DOWN SATURATION LIKELY BRINGING SNOW SHOWER ACTIVITY INTO THE MOUNTAINS OVERNIGHT. WE/LL TALK MORE ABOUT THE NORLUN EVENT IN THE SHORT TERM SECTION BELOW...BUT EXPERIMENTAL HRRR IS ON BOARD WITH THE 12Z GUIDANCE SUITE IN DEVELOPING LLEVEL CONVERGENCE IN THE VICINITY OF PENOBSCOT BAY BY MIDNIGHT TONIGHT...WITH SNOW DEVELOPING IN THIS REGION AND CONTINUING THROUGH THE MORNING. WITH A GOOD FLUFF FACTOR HELPING ACCUMULATIONS...COULD SEE 1-3 INCHES OVER KNOX/WALDO COUNTIES BY DAYBREAK. TEMPERATURES: WITH SOUTHWEST FLOW ONGOING AND CLOUDS ON THE INCREASE...TEMPERATURES WILL BE A GOOD BIT WARMER THAN THE PREVIOUS NIGHT BUT GIVEN THE CHILLY HIGHS OF TODAY...WILL CERTAINLY NOT BE WARM. EXPECT LOWS IN THE SINGLE DIGITS IN THE MOUNTAINS THROUGH THE LOWER TEENS ALONG THE COAST. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... SIGNIFICANT SNOW ALONG THE MID COAST BECOMING INCREASINGLY LIKELY SATURDAY... DANGEROUSLY COLD WIND CHILLS SATURDAY NIGHT THROUGHOUT THE REGION... HIGH IMPACT WEATHER POTENTIAL: HEAVY SNOW TOTALS POSSIBLE IN THE VICINITY OF PENOBSCOT BAY SATURDAY WITH ATTENTION THEN TURNING TO ADVISORY-WARNING LEVEL WIND CHILLS SATURDAY NIGHT. SATURDAY: CORE OF H5 LOW ALOFT SINKS FROM JAMES BAY AT DAYBREAK SOUTH AND EAST INTO NORTHERN NEW ENGLAND TOWARDS EVENING WITH T8S NEARING -30C OVER MY WESTERN ZONES BY 00Z/SUN. COL REGION BETWEEN LOW LEVEL REFLECTION OF THIS H5 LOW AND THE DEVELOPING SYSTEM WELL SOUTH AND EAST OF THE BENCHMARK APPEARS TO BE ALLOWING ALL THE INGREDIENTS FOR A BONA-FIDE NORLUN EVENT TO BE PRESENT AS THE H8 FLOW GOES SLACK ALONG WITH A DEVELOPING LLEVEL CONVERGENCE ZONE. THERE WILL BE AMPLE INSTABILITY IN THE LLEVELS WITH WATER SURFACE TO H8 DELTA TS NEAR -15 AND DELTA TS TO H7 NEARING -30C. THIS ALLOWS FOR A TREMENDOUS AMOUNT OF LLEVEL INSTABILITY...WITH OCEAN-INDUCED CAPE VALUES OF 500-1000 J/KG PORTRAYED ON THE 12Z NAM AND GFS. THIS COULD VERY WELL PROMOTE THUNDER WITH ANY SNOW BAND THAT DOES DEVELOP. SNOW RATIOS: THE DENDRITIC GROWTH ZONE WILL BE BELOW THE PRIMARY AREA OF LIFT DURING THE HEIGHT OF THE EVENT...BUT IT WILL STILL GET CLIPPED AND SEE NO REASON WHY WE CAN/T FORCE 15-20:1 RATIOS OUT OF THIS SETUP. THERE IS UNCANNY AGREEMENT IN THE 12Z SUITE /NAM-GFS-ECMWF-GEM/ ON THE PLACEMENT OF THE MESOSCALE BAND OVER PENOBSCOT BAY. WHILE THIS WOULD TEND TO SUGGEST ABOVE NORMAL CONFIDENCE...THE FACT THAT THIS IS A NORLUN EVENT BEGS CAUTION. A LOOK A THE 00Z NCAR ENSEMBLE SHOWS ABOUT 40% OF THE MEMBERS DIRECTLY IMPACTING OUR AREA. WOULD REALLY LIKE TO SEE THIS EVENT COME INTO THE NEAR TERM-HIGH RESOLUTION GUIDANCE WINDOW AND AS SUCH...WITH THE WORD OUT RIGHT NOW WITH THE WATCH...WILL LET THE EVENING SHIFT TAKE A FINAL LOOK AT THINGS BEFORE MAKING A FINAL DECISION ON WINTER STORM WARNINGS VS. WINTER WEATHER ADVISORIES. THAT BEING SAID...CERTAINLY CANNOT RULE OUT SOME 1 FOOT+ SNOWFALL AMOUNTS SOMEWHERE IN THE MID COAST REGION GIVEN THE SETUP ABOVE. TEMPERATURES: MAY RISE SLIGHTLY IN THE EARLY MORNING...BUT WILL THEN REVERSE COURSE AND FALL THROUGH THE AFTERNOON WITH ALL LOCATIONS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO BY EVENING. WIND CHILLS WILL REACH ADVISORY LEVELS IN THE MOUNTAINS IN THE AFTERNOON...WITH THE MOST DANGEROUS VALUES HOLDING OFF UNTIL SATURDAY NIGHT. NONETHELESS...WIND CHILLS WILL BECOME INCREASINGLY DANGEROUS BY LATE AFTERNOON/EVENING. WINDS: VERY IMPRESSIVE COLD AIR ADVECTION WILL YIELD STEEP LLEVEL LAPSE RATES...WHICH SHOULD BE ABLE TO MIX ANYTHING THE ATMOSPHERE HAS TO OFFER WIND-WISE IN THE LOWEST 5KFT. HIGHEST WINDS IN THE COLUMN ARE AROUND 30KTS /A BIT HIGHER OFFSHORE/ SO WILL PAINT GUSTS AROUND 30MPH INLAND /HIGHER ON THE HILLTOPS/ AND 30-40MPH ALONG THE COAST. NOTE: WINDS WILL NOT BE THIS STRONG IN THE VICINITY OF THE NORLUN TROUGH AND THUS SIGNIFICANT BLOWING/DRIFTING WILL NOT INITIALLY BE A PROBLEM. HOWEVER...BY SATURDAY EVENING...THERE WILL LIKELY BE SIGNIFICANT BLOWING/DRIFTING...AND WILL HAVE TO WATCH FOR THIS IF THE SNOW DOES MATERIALIZE. SATURDAY NIGHT: H5 LOW OPENS UP AND SHIFTS EAST WITH THE CORE OF THE COLDEST AIR ALOFT OVERHEAD UNDER CONTINUED STRONG NORTHWEST WINDS AS GRADIENT BETWEEN 1035 MB HIGH OVER THE GREAT LAKES COMBINES WITH OFFSHORE-MOVING NORLUN TO CONTINUE WINDS OF 15G25KTS. CONCERNS WILL TURN TO DANGEROUSLY COLD WIND CHILLS...WHICH SHOULD HAVE NO PROBLEM HITTING WARNING CRITERIA IN THE MOUNTAINS AND FOOTHILLS...BUT LIKELY REMAIN AT ADVISORY LEVELS ALONG THE COAST. AM HONESTLY A BIT SURPRISED IN THE MET/MAV LOW TEMPERATURE SPREAD AS WE SHOULD REMAIN WELL-MIXED THROUGH THE NIGHT. DID GIVE SOME NOD TO THE COLDER MET...WITH LOWS BELOW ZERO IN ALL LOCATIONS...AND PERHAPS AS LOW AS -20 IN THE MOUNTAINS. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HIGH IMPACT WEATHER: DANGEROUSLY COLD WIND CHILLS LINGER INTO AT LEAST SUNDAY MORNING. A STORM COULD BRING SNOW/FREEZING RAIN/RAIN TO THE REGION MONDAY NIGHT INTO TUESDAY NIGHT. STRONG WINDS ARE POSSIBLE WITH THIS SYSTEM AS WELL. DEEP PERSISTENT 500 TROUGH OVER THE ERN CONUS ON SUNDAY WILL SHIFT NE AND WEAKEN BY EARLY NEXT WEEK...AND THIS ALLOWS THE HEMISPHERIC WAVE PATTERN TO BECOME LESS AMPLIFIED WITH A HIGHER WAVE NUMBER. THE OVERALL +PNA PATTERN WEAKENS EARLY TO MID-WEEK...AND TRIES TO BREAK DOWN BY THE END OF THE WEEK. OF NOTE THOUGH...IS SRN STREAM WAVE THAT DIGS OVER S CENTRAL CONUS MON AND LIFTS NWD TUE AND WED AS NRN STREAM DIVES INTO IT AND THIS COULD PRODUCE THE HIGH IMPACT STORM OVER NEW ENGLAND AROUND TUESDAY. SUNDAY START IN THE THROES OF THE THE VERY COLD AIR MASS IN THE REGION WITH STRONG PRES GRAD IN PLACE AND GUSTY NW WINDS. THE DANGEROUS WIND CHILLS LINGER THRU THE MORNING BUT AS TEMPS WARM FROM LOWS BELOW ZERO EVERYWHERE...AND WITH PRES GRADIENT SLACKENING AS SFC HIGH BUILDS IN SHOULD SEE WIND CHILLS RISE TO MORE BEARABLE LVLS BY AFTERNOON. STILL...THE TAIL OF THE CAA WILL HOLD THRU MOST OF THE DAY AND HIGHS WILL STRUGGLE TO REACH ZERO IN THE N...AND TO REACH 10F IN THE SOUTH. AS THE SFC HIGH MOVES OVER THE REGION LOOK FOR DECOUPLING IN MOST PLACES AND VERY GIVEN GOOD RAD COOLING GIVEN COLD AIR IN PLACE AND A STARTING POINT NEAR OR BELOW ZERO. WENT BELOW SUPERBLEND FOR MINS IN MOST PLACES...AND SIGNIFICANTLY BELOW IN THE MORE SHELTERED SPOTS. THIS SHOULD BRINGUS LOWS 10 BELOW TO ZERO IN THE COASTAL PLAIN...WITH LOWS DROPPING TO -20 OR LOWER IN THE SHELTERED MOUNTAIN VALLEYS. ON MONDAY LOOK FOR WARMER AIR TO START WORKING IN...AND HIGHS REBOUND INTO THE TEENS TO MID 20S...WITH INCREASING CLOUDS IN THE AFTERNOON. THE NEXT SYSTEM MOVES IN ON MON NIGHT AND TUE. SOME DIFFERENCES IN THE MODEL AS TO HAVE FAR W THE SFC LOW TRACKS...WITH THE GFS AND GGEM PASSING IT S-N THRU THE MIDDLE OF ME...AND THE EURO AND GEFS MEAN BRINGING IT NWD ALONG THE NY/VT BORDER...WHICH WOULD BE THE WARMER SOLN...AND LIKELY LEAD TO SNOW TO FZRA/PL TO RAIN SOLN IN MANY SPOTS. THE MORE EASTERLY TRACK WOULD SEE SNOW LAST LONGER INTO THE STORM AWAY FROM THE COAST. P-TYPE WILL BE ONE OF THE BIG ISSUES WITH THIS SYSTEM AND CONFIDENCE IS LOW AS TO HOW IT WILL ALL UNFOLD. ONE THING TO NOTE IS THAT WE ARE COMING OUT OF VERY COLD AIRMASS...AND DESPITE THE BEST WINDS ABOVE THE INVERSION IT WILL BE SLOW TO BREAK OUT OF THAT LOW LVL COLD AIR...WHICH WILL PROBABLY HOLD ON LONGER THAN THE MODELS SUGGEST. ANOTHER ISSUE COULD BE STRONG WINDS...ALTHOUGH WITH THE INVERSION MAY BE TOUGH FOR THOSE WINDS TO MIX TO THE SFC...AT LEAST FOR ANY SIGNIFICANT LENGTH OF TIME. THE WHOLE SYSTEM WILL MOVE OUT LATE TUE NIGHT AND WED. COULD BUST OUT INTO WARMER AIR ON WED BEHIND THE SYSTEM WITH HIGHS CLIMBING INTO THE UPPER 30S TO LOW 40S. COLD FRONT SWINGS THRU WED NIGHT WITH UPPER LVL TROUGH ON THU AND TEMPS DROP BACK AGAIN...BELOW NORMAL...BUT NOT TOO FAR...WITH HIGHS IN THE 20S TO AROUND 30. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM...VFR UNDER MOSTLY CLEAR CONDITIONS ATTM. EXPECT DETERIORATING CONDITIONS THROUGH THE COMING TAF PERIOD WITH SNOW DEVELOPING OVERNIGHT AT RKD AND LIKELY AUG WITH IFR/LIFR RESTRICTIONS. FOR A PERIOD SATURDAY...INCH PER HOUR SNOWFALL RATES ARE POSSIBLE...MOST LIKELY AT RKD. FURTHER WEST...ARCTIC FRONT WILL BRING A ROUND OF SNOW SHOWERS...MOST LIKELY TO BRING RESTRICTIONS TO LEB/HIE...BUT BRIEF RESTRICTIONS ARE POSSIBLE SOUTH AND EAST OF THIS AS WELL. CONDITIONS IMPROVE SATURDAY NIGHT WITH VFR CONDITIONS RETURNING FOR SUNDAY. AFTER LIGHT WINDS OVERNIGHT...STRONG NORTHWEST WINDS /15G25KTS/ WILL DEVELOP BY LATE MORNING SATURDAY AND CONTINUE THROUGH SATURDAY NIGHT. LONG TERM...MAINLY VFR SUN THRU MON WITH GUSTY NW WINDS DIMINISHING DURING SUN AFTERNOON. COULD SEE EXTENDED PERIOD OF IFR OR LOWER IN SN/FZRA/RA MON NIGHT INTO TUE NIGHT. && .MARINE... SHORT TERM...WINDS/WAVES BELOW SMALL CRAFT LEVELS INTO TOMORROW MORNING BEFORE INTENSE COLD ADVECTION BEHIND AN ARCTIC COLD FRONT BRINGS A PERIOD OF GALES TO THE OUTER WATERS BY LATE SATURDAY AFTERNOON THROUGH SUNDAY MORNING WITH WINDS LIKELY REMAINING BELOW GALE FORCE IN THE BAYS. IN ADDITION...HEAVY FREEZING SPRAY WARNINGS HAVE BEEN HOISTED SATURDAY EVENING THROUGH SUNDAY MORNING GIVEN THE COMBINATION OF THE AFOREMENTIONED WINDS AND THE COLDEST AIRMASS OF THE SEASON THUS FAR. LONG TERM...NW WIND DIMINISH SLOWLY THRU SUNDAY...AS DOES INTENSITY OF FREEZING SPRAY...BUT WILL LKLY HOLD TO SCA WINDS THRU SUN EVE. AFTER A BRIEF BREAK IN THE WINDS ON MON AND MON NIGHT...LOOK FOR S WINDS TO REACH SCA LVLS EARLY TUE AND COULD REACH GALES BY TUE AFTERNOON AND EVE...BEFORE DIMINISHING WED. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...WIND CHILL WARNING FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR MEZ012>014-018>022. WIND CHILL WARNING FROM 7 PM SATURDAY TO 10 AM EST SUNDAY FOR MEZ007>009. WIND CHILL ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR MEZ023>028. WINTER STORM WATCH FROM MIDNIGHT EST TONIGHT THROUGH SATURDAY EVENING FOR MEZ022-027-028. NH...WIND CHILL WARNING FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR NHZ004>013-015. WIND CHILL WARNING FROM 7 PM SATURDAY TO 10 AM EST SUNDAY FOR NHZ001>003. WIND CHILL ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR NHZ014. MARINE...HEAVY FREEZING SPRAY WARNING FROM 7 PM SATURDAY TO NOON EST SUNDAY FOR ANZ150>154. SMALL CRAFT ADVISORY FROM NOON SATURDAY TO NOON EST SUNDAY FOR ANZ151-153. GALE WARNING FROM 4 PM SATURDAY TO NOON EST SUNDAY FOR ANZ150- 152-154. && $$ NEAR TERM UPDATE...EKSTER SHORT TERM...ARNOTT LONG TERM...CEMPA AVIATION...ARNOTT/CEMPA MARINE...ARNOTT/CEMPA
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
632 PM EST FRI FEB 12 2016 .SYNOPSIS... AN ARCTIC FRONT WILL BRING SNOW SHOWERS TO THE AREA THROUGH SATURDAY. MUCH COLDER TEMPERATURES AND DANGEROUS WIND CHILLS WILL CONTINUE INTO THE WEEKEND. && .NEAR TERM /THROUGH SATURDAY/... BASED ON LATEST OBSERVATIONS AND RADAR TRENDS CURRENT TIMING OF POTENTIAL SQUALL CONDITIONS STILL LOOKS GOOD AS WV IMAGERY SHOWS THE JET CORE ROUNDING THE BASE OF THE LONGWAVE PIVOTING OVER THE AREA. NOT MUCH CHANGE IS NEEDED AT THIS TIME TO THE ONGOING FORECAST OTHER THAN MINOR ADJUSTMENTS TO HOURLY TEMPERATURES. PREV DISCUSSION FOLLOWS.. SHORTWAVE PIVOTING ALONG THE BASE OF THE UPPER TROUGH WILL SUPPORT INCREASING SNOW CHANCES IN THE RIDGES AHEAD OF THE ARCTIC FRONT PASSAGE PROGGED FOR THIS EVENING/OVERNIGHT. BOTH HI RES AND LONGER RANGE MODEL SOUNDINGS IN BUFKIT SUGGEST A PERIOD WHERE DEEP MOISTURE...IN A LAYER FROM ABOUT 600MB TO 850MB...WILL BE WELL WITHIN THE DENDRITIC GROWTH ZONE. THIS SHOULD SUPPORT EFFICIENT SNOWFALL FOR A PERIOD...WITH ADDITIONAL SNOW SHOWERS ANTICIPATED WITH AND BEHIND THE FRONT IN UPSLOPE SNOW UNTIL THE WHOLE BOUNDARY LAYER FALLS WELL BELOW THE GROWTH ZONE. WITH THIS IN MIND...A WINTER WEATHER ADVISORY WAS ISSUED FOR THE RIDGES OF PRESTON TUCKER AND GARRETT COUNTIES THROUGH SATURDAY MORNING. ELSEWHERE...THE MODEL GUIDANCE HAS CHANGED LITTLE WITH THE TIMING OF THE SNOW SHOWERS AND POTENTIAL SQUALLS AHEAD OF THE FRONT PROGGED FOR PASSAGE OVERNIGHT. EXPECT THE LINE TO BE INTO EASTERN OHIO AND NORTHWESTERN PA BY 00Z AND PITTSBURGH BY 03Z. VARIOUS RUNS OF THE HRRR AND TO A LESSER DEGREE OTHER SNOW SQUALLS PROGS SUGGEST THAT THERE WILL BE SOME WEAKENING AS THE LINE COMES ACROSS. GENERALLY ANTICIPATE A HALF TO AN INCH OF SNOW...WITH SLIGHTLY HIGHER AMOUNTS NORTH OF PITTSBURGH. BEHIND THE FRONT...STRONG COLD ADVECTION WILL STEEPEN LAPSE RATES AND PROVIDE FOR A PERIOD OF GUSTY WINDS AREAWIDE UNTIL LATE SATURDAY WITH MAXIMUM WIND IN THE BOUNDARY LAYER APPROACHING 25 TO 35KTS. THIS...ADDED TO TEMPERATURES FALLING INTO THE SINGLE DIGITS WILL LEAD TO WIND CHILL VALUES WELL BELOW ZERO. THIS SUPPORTS THE WIND CHILL ADVISORY THAT WAS ISSUED. 40MPH WIND GUSTS OVERNIGHT IN THE RIDGES WILL ALLOW VALUES TO GET VERY CLOSE TO WARNING CRITERIA BUT AT THIS POINT...THE WATCH HAS BEEN UPGRADED TO AN ADVISORY WITH SOME -25 VALUES POSSIBLE IN THE HIGHEST TERRAIN OF TUCKER COUNTY. IN ADDITION TO THE WIND...LAKE EFFECT SNOW SHOWERS WILL BE POSSIBLE IN NORTHWEST FLOW WITH MOST IF NOT ALL OF THE MODEL GUIDANCE SUGGESTING SEVERAL DUAL-LAKE SNOW BANDS. THE LATEST ITERATION OF MODELS HAS THE MORE PROMINENT BAND SHIFTED SLIGHTLY SOUTH FROM LAST NIGHT SO WITH UNCERTAINTY IN THE ACTUAL PLACEMENT OF SNOW BANDS...HAVE OPTED TO UPGRADE THE LAKE EFFECT SNOW WATCH FOR VENANGO COUNTY TO AN ADVISORY FOR MERCER...VENANGO...AND FOREST COUNTIES. ADDITIONAL LAKE PLUMES MAY SUPPORT SNOW BEYOND THESE ADVISORIES THROUGH SATURDAY AFTERNOON...BUT WITH UNCERTAINTY IN THEIR PLACEMENT...NO ADDITIONAL HEADLINES WERE ADDED. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO TAPER OFF AND SHIFT NORTHWARD AS A SURFACE RIDGE ATTEMPTS TO BUILD OVERHEAD FOR SUNDAY. THIS SHOULD ALLOW FOR THE WIND TO BACK OFF...WITH WIND CHILL CONCERNS DIMINISHING IN OHIO. HOWEVER...WITH THE HIGH PRESSURE AND LIGHT WIND...TEMPERATURES WILL FALL CLOSE TO OR BELOW ZERO SATURDAY NIGHT...SO ADVISORIES WILL REMAIN AS IS FOR THE REST OF THE CWA UNTIL SUNDAY MORNING. TEMPERATURES WILL MODERATE A FEW DEGREES ON SUNDAY WITH A RETURN OF SOUTHERLY FLOW AND SCATTERING OF THE CLOUDS. TEMPERATURE FORECAST WAS A BLEND OF GUIDANCE FOR BOTH PERIODS. && .LONG TERM /MONDAY THROUGH FRIDAY/... SHORTWAVE MOVING EAST ACROSS THE GREAT LAKES WILL BRING WARM ADVECTION ALONG WITH AN INCREASE IN DEEPER MOISTURE SUNDAY NIGHT INTO MONDAY. THIS WILL GIVE A PERIOD OF SNOW ESPECIALLY SOUTH OF PITTSBURGH WITH SOME ACCUMULATION EXPECTED. TEMPERATURES LOOK TO RISE LATER SUNDAY NIGHT AND WILL PUSH TO NEAR THE SEASONAL AVERAGE MONDAY. BY LATER MONDAY THROUGH TUESDAY A STRONG SOUTHERN STREAM SHORTWAVE WILL INDUCE LOW PRESSURE ALONG THE GULF COAST WHICH WILL QUICKLY MOVE ACROSS THE MID ATLANTIC STATES. MODELS STILL DIFFER ON EXACT TRACK BUT SYSTEM WILL CROSS THE SOUTHERN APPALACHIANS AND INTENSIFY AS IT MOVES TOWARD NEW ENGLAND BY TUESDAY NIGHT. POTENTIAL FOR SIGNIFICANT SNOW...BUT ALSO POTENTIAL FOR A MIX WITH RAIN OR ALL RAIN WHERE BETTER QPF IS FORECAST. FOR NOW HAVE NOT STRAYED FAR FROM PREVIOUS FORECAST ALTHOUGH EVEN THE WARMER ECMWF WRAPS COLD AIR BACK IN LATER TUESDAY SO HAVE KEPT MAINLY SNOW. SYSTEM EXITS TUESDAY NIGHT...BUT WILL BE FOLLOWED BY FAST MOVING CLIPPER SYSTEM WEDNESDAY WHICH WILL DELIVER ANOTHER PERIOD OF SNOW SHOWERS FOLLOWED BY A QUICK SHOT OF COLD AIR. HEIGHTS ALOFT THEN BEGIN TO RISE THURSDAY INTO FRIDAY WITH STRONG WARM ADVECTION...ESPECIALLY ON FRIDAY. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... MOST IMPORTANT FEATURE THROUGH THE BEGINNING OF THE TAFS WILL BE THE ARRIVAL OF AN ARCTIC FRONT. UPSTREAM OBSERVATIONS AT CLEVELAND SHOW 1/4SM VISIBILITY WITH HEAVY SNOW AND NORTHWEST WIND GUSTS TO 30KT. ALTHOUGH THE LINE OF SNOW SHOWERS ALONG THE FRONT WILL WEAKEN SOMEWHAT AS IT MOVES INLAND OFF LAKE ERIE...STILL THINK THAT WIDESPREAD 1/2 TO 1 MILE VISIBILITIES AND WIND GUSTS TO 25-30KT ARE POSSIBLE AT EACH TERMINAL AS THE LINE MOVES THROUGH. THIS LINE SHOULD HAVE MOVED THROUGH ALL LOCAL TERMINALS BY 06Z. ALTHOUGH SNOW WITH MVFR/IFR VISIBILITIES WILL CONTINUE OVERNIGHT BEHIND THE FRONT AT MOST TERMINALS...FKL IS LIKELY TO BE THE TERMINAL WITH THE LOWEST FLIGHT CONDITIONS DUE TO THE POTENTIAL OF A LAKE HURON- ERIE SNOWBAND TO SET UP WITH NORTHWEST WINDS. THE POTENTIAL FOR MODERATE SNOW WILL CONTINUE THERE THROUGH MUCH OF SATURDAY. ZZV COULD MANAGE TO EITHER SCATTER OUT OR HAVE CEILINGS LIFT TO VFR ON SATURDAY. WIND GUSTS TO 25 KT WILL CONTINUE BEHIND THE FRONT AND SHOULD LAST THROUGH THE TAF PERIOD. .OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/... LOW PRESSURE SYSTEMS WILL BRING WIDESPREAD RESTRICTIONS LATER SUNDAY NIGHT THROUGH WEDNESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY FOR MDZ001. WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ001. OH...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST SATURDAY FOR OHZ039-048-049-057>059-068-069. WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY FOR OHZ040-041-050. PA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY FOR PAZ007>009-013>016-020>023-029-031-073>076. LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST SATURDAY FOR PAZ007>009. WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST SATURDAY FOR WVZ003-004-012. WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY FOR WVZ001-002-021-509>514. WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR WVZ512>514. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
559 PM EST THU FEB 11 2016 .SYNOPSIS... SCATTERED SNOW SHOWERS SHOULD END TONIGHT AS HIGH PRESSURE BUILDS IN. A COLD FRONT WILL BRING MORE SNOW CHANCES FRIDAY AND SATURDAY...WITH MUCH COLDER TEMPERATURES FOR THE WEEKEND. && .NEAR TERM /THROUGH FRIDAY/... WITH 6PM UPDATE...TWEAKED HOURLY POPS AND TEMPERATURES...KEEPING SCATTERED SNOW SHOWERS IN THE FORECAST SLIGHTLY LONGER FOR THE TIER OF COUNTIES JUST NORTH OF PITTSBURGH WHERE ECHOES HAVE HELD ON THE LONGEST. ALTHOUGH THE VERY COLD AIR IS NOT EXPECTED TO MOVE INTO THE REGION UNTIL TOMORROW NIGHT...LATEST HRRR RUNS SUGGEST TEMPERATURES COULD PLUMMET ALONG INTERSTATE 80 IF SKIES MANAGE TO CLEAR OUT. THINK THE CLOUDS WILL HANG IN LONG ENOUGH TO PREVENT THIS FROM HAPPENING...BUT WILL KEEP AN EYE ON THIS THROUGHOUT THE NIGHT. PREVIOUS DISCUSSION FOLLOWS. SCATTERED LAKE ENHANCED SNOW SHOULD CONTINUE TO TAPER OFF THRU THE EVE AS MDL PROGGED AND OBSERVED UPSTREAM SOUNDINGS SHOW LWRG TEMP INVERSIONS...AND WKNG LAPSE RATES. BLDG HIGH PRESSURE SHOULD BRING CLRG SKIES TONIGHT. TEMPS SHOULD AVG AROUND 15 DEG BELOW SEASONAL LVLS USING THE LATEST NR TERM CONSENSUS BLENDED GUIDANCE. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... THE NEXT SHORTWAVE IS PROGGED TO CROSS THE LWR OH VLY/MID ATLANTIC RGN FRI BRINGING INCRG LGT SNOW CHCS. ANOTHER SHORTWAVE...AND ASSOCIATED COLD FRONT...IS EXPD TO CROSS THE RGN FRI EVE WITH BETTER CHCS FOR SNOW SHOWERS. THE SNOW SHOWERS SHOULD CONTINUE UNDER UPR TROFG AND LAKE/TERRAIN ENHANCEMENT LATER FRI NGT AND SAT...THOUGH ACCUMULATIONS ARE EXPD TO REMAIN BELOW ADVISORY CRITERIA AS DRY ARCTIC AIR RESULTS IN UNFAVORABLE MOISTURE CONTENT IN THE SNOW GROWTH RGN. BLDG HIGH PRESSURE SAT NGT/SUN SHOULD BRING DRY WEATHER. WIND WITH SUFFICIENT PRES GRADIENT AND COLD TEMPS FRIDAY NIGHT THRU SOMETIME SAT WILL LIKELY RESULT IN ADVISORY LVL WIND CHILLS ACRS MUCH OF THE AREA. DIMINISHING WINDS MAY PROVIDE FOR LESSER CHCS OF WIND CHILL ADVISORIES SAT NGT/ERLY SUN...THOUGH TEMPS NR OR BELOW ZERO ARE EXPD. TEMPS WERE MODIFIED SLIGHTLY FROM SUPERBLENDED GUIDANCE. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FAST MOVING SHORTWAVE WILL BRING A CHANCE FOR SNOW LATER SUNDAY NIGHT INTO MONDAY AS TEMPERATURES MOVE TOWARD SEASONAL AVERAGES TO START THE WEEK. MODELS HAVE DIFFERING SOLUTIONS FOR SOUTHERN STREAM STORM SYSTEM INTENSIFYING AND MOVING NORTHEAST LATER MONDAY INTO TUESDAY. SPLIT THE DIFFERENCE BETWEEN WPC PROGS AND THE SUPERBLEND...WITH HIGHEST POPS INTO THE SOUTHEAST RIDGES. THIS WILL BE FOLLOWED BY A CLIPPER TYPE SYSTEM WEDNESDAY WITH CHANCE POPS. TEMPERATURES WILL BE NEAR THE SEASONAL NORM. HIGH PRESSURE LOOKS TO GIVE A DRY DAY THURSDAY. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... SCT SNOW SHOWERS WILL STILL GIVE MVFR AT TIMES FOR NRN PORTS INTO LATE AFTERNOON...BEFORE HIGH PRESSURE TURNS THE FLOW AND BEGINS TO CLEAR SKIES THIS EVENING FOR VFR CONDITIONS. WEST WINDS 10-15KTS WILL SUBSIDE AFTER SUNSET. .OUTLOOK.../FRIDAY THROUGH TUESDAY/... RESTRICTIONS WILL BE POSSIBLE IN SNOW SHOWERS LATER FRIDAY INTO SATURDAY. THE NEXT CHANCE FOR WIDESPREAD IFR WILL BE WITH LOW PRESSURE MONDAY AND TUESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
316 PM CST THU FEB 11 2016 .SHORT TERM: (Through Late Tonight) Issued at 1230 PM CST Thu Feb 11 2016 A northwest flow shortwave now dropping southeastward into western SD will move quickly through our area tonight. Light snow will spread southeastward into northeast MO early this evening, then through the St Louis metro area around midnight. Still looking like a quick shot of dry, powdery snow with most places picking up to 1 inch of accumulation, but there may be a narrow band of 1-2 inches extending from near IRK southeast through the St Louis metro area. Latest NAM and HRRR model runs have the band a little further west than previous model runs. Most of the accumulating snow should shift southeast of our forecast area by 12Z Friday. Low temperatures will be similar to the previous night, and around 5 degrees below normal. GKS .LONG TERM: (Friday through Next Thursday) Issued at 316 PM CST Thu Feb 11 2016 A strong cold front will move southeastward through our forecast area on Friday with strengthening winds as the surface pressure gradient tightens as a strong 1040-1045 mb surface high builds southeastward into the area from the northern Plains behind the cold front. Temperatures may begin to fall in northeast MO behind the front already by Friday afternoon. Much colder temperatures are expected for Friday night and Saturday with wind chills down to around 10 below zero late Friday night and early Saturday morning across northeast MO and west central IL. Snow should spread southeastward into at least northeast MO and west central IL late Saturday night as low-mid level warm air advection increases ahead of an approaching northern stream shortwave. It still appears that the ECMWF model is a little too quick bringing precipitation into our forecast area already be Saturday afternoon and evening with an initially very dry boundary layer on the backside of the surface ridge. The better chance of precipitation should occur on Sunday as a southwesterly low level jet brings increasing low level moisture into our area ahead of the shortwave. It is too early to pin down exact snow totals, but it initially appears that 2-4 inches is possible across northeast MO and west central IL with lesser amounts of 1-2 inches further south for Saturday night and Sunday. Another round of precipitation is expected, mainly on Monday, as a southern stream shortwave and associated surface low pass south of our area. This precipitation should be confined mainly to southeast MO and southwest IL. With temperatures trending up as we head into the next work week there may also be precipitation type issues with a mix of snow, sleet and rain possible. Will keep the rest of the forecast dry with a warming trend, although the ECMWF model does depict some weaker weather systems bringing a brief period or two of light QPF to our area. The GFS model is dry for the remainder of the period after Monday with a dry cold frontal passage on Tuesday afternoon and evening. Both the GFS and ECMWF models depict a warm weather pattern by Thursday with upper level ridging over the region along with strong s-swly low level winds likely leading to well above normal temperatures. GKS && .AVIATION: (For the 18z TAFs through 18z Friday Afternoon) Issued at 1237 PM CST Thu Feb 11 2016 SC has dissipated over taf sites, so will see VFR conditions through early this evening as mid and high clouds stream in ahead of next clipper system. Timing still similar to last set of tafs with snow moving into KUIN/KCOU by 02z Friday and STL metro area by 04z Friday. With onset of light snow, will see cigs dip down to MVFR with brief IFR visbys as heavier bands of snow move through. Snow to taper off between 09z and 10z Friday for taf sites, though mvfr cigs to persist. KCOU on western periphery so should see mvfr cigs scatter out by 16z Friday. As for winds, to remain from the northeast to east as system moves through, then become light and variable. By mid morning on Friday, winds to pickup from the northwest. Specifics for KSTL: SC has dissipated over metro area, so will see VFR conditions through early this evening as mid and high clouds stream in ahead of next clipper system. Timing still similar to last set of tafs with snow moving into STL metro area by 04z Friday. With onset of light snow, will see cigs dip down to MVFR with brief IFR visbys as heavier bands of snow move through. Snow to taper off by 10z Friday, though mvfr cigs to persist for rest of taf forecast period. As for winds, to remain from the northeast to east as system moves through, then become light and variable by 10z Friday. By 17z Friday, winds to pickup from the northwest around 10 kts. Byrd && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1248 PM CST THU FEB 11 2016 .SHORT TERM: (Through Late Tonight) Issued at 1230 PM CST Thu Feb 11 2016 A northwest flow shortwave now dropping southeastward into western SD will move quickly through our area tonight. Light snow will spread southeastward into northeast MO early this evening, then through the St Louis metro area around midnight. Still looking like a quick shot of dry, powdery snow with most places picking up to 1 inch of accumulation, but there may be a narrow band of 1-2 inches extending from near IRK southeast through the St Louis metro area. Latest NAM and HRRR model runs have the band a little further west than previous model runs. Most of the accumulating snow should shift southeast of our forecast area by 12Z Friday. Low temperatures will be similar to the previous night, and around 5 degrees below normal. GKS .LONG TERM: (Tonight through Wednesday) Issued at 225 AM CST Thu Feb 11 2016 ...Light Snow Expected This Evening... Next shortwave will be diving southeast in a similar manner to yesterday`s and provide the area with another round of light snow. It appears that this snow will be a little later in its arrival with the main window of accumulation occurring from 6 pm to Midnight. Once again have about an inch, give or take a few tenths, of snow accumulation forecast from northeast Missouri to southwest Illinois. This includes the Greater St. Louis Metropolitan Area. Snow should taper off after midnight from northwest to southeast, with a few flurries possible Friday morning. Thereafter, a very cold air mass builds into the region Friday night and Saturday. Low temperatures below zero are certainly possible Saturday morning across the northern CWA. The arctic high pressure quickly moves east though and by Saturday night we could already have a band of warm advection snow racing across the CWA. Better chance of accumulating snow appears to occur on Sunday, but to be honest, medium range model guidance has been flip flopping all over the place with this system the past five days and still hasn`t landed on a common solution. Best to leave PoPs at a chance for the period in question and give it a few more runs before trying to nail down specifics. Warm up looks on tap next week as the pattern changes with highs in the 50s and maybe even 60s! CVKING && .AVIATION: (For the 18z TAFs through 18z Friday Afternoon) Issued at 1237 PM CST Thu Feb 11 2016 SC has dissipated over taf sites, so will see VFR conditions through early this evening as mid and high clouds stream in ahead of next clipper system. Timing still similar to last set of tafs with snow moving into KUIN/KCOU by 02z Friday and STL metro area by 04z Friday. With onset of light snow, will see cigs dip down to MVFR with brief IFR visbys as heavier bands of snow move through. Snow to taper off between 09z and 10z Friday for taf sites, though mvfr cigs to persist. KCOU on western periphery so should see mvfr cigs scatter out by 16z Friday. As for winds, to remain from the northeast to east as system moves through, then become light and variable. By mid morning on Friday, winds to pickup from the northwest. Specifics for KSTL: SC has dissipated over metro area, so will see VFR conditions through early this evening as mid and high clouds stream in ahead of next clipper system. Timing still similar to last set of tafs with snow moving into STL metro area by 04z Friday. With onset of light snow, will see cigs dip down to MVFR with brief IFR visbys as heavier bands of snow move through. Snow to taper off by 10z Friday, though mvfr cigs to persist for rest of taf forecast period. As for winds, to remain from the northeast to east as system moves through, then become light and variable by 10z Friday. By 17z Friday, winds to pickup from the northwest around 10 kts. Byrd && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
1231 PM CST THU FEB 11 2016 .SHORT TERM: (Through Late Tonight) Issued at 1230 PM CST Thu Feb 11 2016 A northwest flow shortwave now dropping southeastward into western SD will move quickly through our area tonight. Light snow will spread southeastward into northeast MO early this evening, then through the St Louis metro area around midnight. Still looking like a quick shot of dry, powdery snow with most places picking up to 1 inch of accumulation, but there may be a narrow band of 1-2 inches extending from near IRK southeast through the St Louis metro area. Latest NAM and HRRR model runs have the band a little further west than previous model runs. Most of the accumulating snow should shift southeast of our forecast area by 12Z Friday. Low temperatures will be similar to the previous night, and around 5 degrees below normal. GKS .LONG TERM: (Tonight through Wednesday) Issued at 225 AM CST Thu Feb 11 2016 ...Light Snow Expected This Evening... Next shortwave will be diving southeast in a similar manner to yesterday`s and provide the area with another round of light snow. It appears that this snow will be a little later in its arrival with the main window of accumulation occurring from 6 pm to Midnight. Once again have about an inch, give or take a few tenths, of snow accumulation forecast from northeast Missouri to southwest Illinois. This includes the Greater St. Louis Metropolitan Area. Snow should taper off after midnight from northwest to southeast, with a few flurries possible Friday morning. Thereafter, a very cold air mass builds into the region Friday night and Saturday. Low temperatures below zero are certainly possible Saturday morning across the northern CWA. The arctic high pressure quickly moves east though and by Saturday night we could already have a band of warm advection snow racing across the CWA. Better chance of accumulating snow appears to occur on Sunday, but to be honest, medium range model guidance has been flip flopping all over the place with this system the past five days and still hasn`t landed on a common solution. Best to leave PoPs at a chance for the period in question and give it a few more runs before trying to nail down specifics. Warm up looks on tap next week as the pattern changes with highs in the 50s and maybe even 60s! CVKING && .AVIATION: (For the 12z TAFs through 12z Friday Morning) Issued at 544 AM CST Thu Feb 11 2016 VFR flight conditions expected today with band of cigs from 4-5kt feet stretching from northern MO into southern Il slowly sinking south this morning. In the wake of these clouds, mid-high clouds will move into the area this afternoon in advance of the next fast-moving system. Another band of light snow will spread into the region early this evening and exit the area after 09z. KUIN and the St. Louis region terminals will likely have a period of MVFR- IFR flight conditions. Impacts at KCOU are a bit more uncertain and MVFR conditions appear to be possible. Snow amounts will be similar to yesterdays event, averaging near 1 inch. Specifics for KSTL: VFR flight conditions are expected today with band of cigs from 4-5kt during the morning. In the wake of these clouds, mid-high clouds will move into the area this afternoon in advance of the next fast-moving system. Light snow will spread into the terminal mid-late evening and exit the area after 09z, bringing a period of MVFR-IFR flight conditions. Snow amounts will be similar to yesterdays event, averaging near 1 inch. Glass && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
534 PM CST FRI FEB 12 2016 .SYNOPSIS... ISSUED AT 330 PM CST FRI FEB 12 2016 ANALYSIS OF THE 18Z MSL DATA SHOWED HIGH PRESSURE FROM EASTERN SASKATCHEWAN TO EASTERN SOUTH DAKOTA. THERE WAS A QUASI-STATIONARY FRONT FROM NORTHWEST MONTANA...THROUGH EASTERN WYOMING...TO SOUTHEAST COLORADO. IN THE WATER VAPOR IMAGERY...A PLUME OF MID- LEVEL MOISTURE WAS INDICATED FROM THE PACIFIC OFF THE CALIFORNIA COAST...ACROSS THE ROCKIES...AND ACROSS THE NORTHERN PLAINS. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 330 PM CST FRI FEB 12 2016 ISENTROPIC UPGLIDE DEVELOPS IN THE 280-285K LAYER BY EARLY THIS EVENING IN SOUTHWEST NEBRASKA OVER THE STATIONARY FRONT. THE LIFT IS WEAK AND NOT IN A THICK LAYER IN THE SOUTHWEST AND THE WESTERN SANDHILLS. THIS WOULD BE CONDUCIVE FOR THE DEVELOPMENT OF LIGHT FREEZING DRIZZLE. BY EARLY SATURDAY...THE LIFT EXTENDS TO NEAR 500MB IN THE 290-305K LAYER AND INTO THE DENDRITIC GROWTH ZONE OVER CENTRAL AND NORTH CENTRAL NEBRASKA...THUS FAVORING LIGHT SNOW. BY EARLY AFTERNOON SATURDAY...THE LOW LEVEL TEMPERATURES WARM ENOUGH THAT THE THREAT OF FREEZING DRIZZLE DIMINISHES IN THE SANDHILLS AND SOUTHWEST BUT THE LOW STRATUS IS LIKELY TO CONTINUE THROUGH LATE SATURDAY AFTERNOON OR EARLY EVENING. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 330 PM CST FRI FEB 12 2016 MID TERM...SATURDAY NIGHT THROUGH MONDAY...IN THE MIDTERM...THE THREAT FOR LIGHT SNOW IN THE NORTH SATURDAY NIGHT...FOLLOWED BY A THREAT FOR LIGHT PCPN IN THE WEST SUNDAY NIGHT WILL BE THE MAIN FORECAST CONCERNS. FOR SATURDAY NIGHT...A MID LEVEL TROUGH WILL APPROACH THE WESTERN DAKOTAS SATURDAY EVENING. STRONG MID LEVEL FRONTOGENESIS AND DECENT MID LEVEL WAA WILL SPREAD EAST ACROSS SOUTH DAKOTA SATURDAY NIGHT. THIS WILL LEAD TO SNOWFALL ACROSS SOUTH DAKOTA. SOME WEAK LIFT WITH THIS SYSTEM WILL TRACK ACROSS FAR SRN SOUTH DAKOTA AND FAR NRN NEBRASKA IN ASSOCIATION WITH THIS MAIN UPPER LEVEL SYSTEM SATURDAY NIGHT...AND LOW CHANCES FOR LIGHT SNOW WERE RETAINED ROUGHLY NORTH OF A LINE FROM HAY SPRINGS TO EWING. ANY ACCUMULATIONS ACROSS NORTHERN NEBRASKA WILL BE VERY LIGHT...ON THE ORDER OF A HALF AN INCH TO AN INCH. AFTER MAINLY DRY CONDS ON SUNDAY...A JET STREAK AND SECONDARY MID LEVEL DISTURBANCE WILL DROP SOUTH FROM EASTERN WYOMING INTO NERN COLORADO AND WESTERN KANSAS. THESE LOCATIONS...ALONG WITH FAR SWRN NEBRASKA WILL BE IN THE FAVORABLE LEFT FRONT QUAD OF THE JET STREAK SUNDAY NIGHT...AND INSERTED SOME SLIGHT CHANCE POPS ACROSS FAR SWRN NEBRASKA. THIS SYSTEM WILL BE FAIRLY MOISTURE STARVED GIVEN THE EXITING SYSTEM SATURDAY NIGHT...SO WILL KEEP POPS AND QPF/S MINIMAL. ON MONDAY INTO MONDAY NIGHT...RIDGING WILL BUILD INTO THE NORTHERN ROCKIES...FORCING A WARM FRONT THROUGH THE DAKOTAS AND NORTHERN NEBRASKA. AS THIS FEATURE PROGRESSES EAST MONDAY NIGHT...A FAVORABLE SET UP FOR PCPN WILL EXIST ACROSS THE DAKOTAS...AND NORTHERN NEBRASKA. ATTM...THE BEST DYNAMICS WILL BE LOCATED OVER EASTERN SOUTH DAKOTA IN CLOSEST PROXIMITY TO THE LEFT FRONT QUAD OF THE JET. HOWEVER...WEAK LIFT IS NOTED WITH THIS FRONT OVER FAR NORTHWESTERN AND NORTHEASTERN PORTIONS OF THE FORECAST AREA MONDAY NIGHT. TEMPERATURES WILL BE WARM ENOUGH MONDAY EVENING TO SUPPORT ALL RAIN...WITH A RAIN SNOW MIX POSSIBLE OVERNIGHT AS TEMPERATURES BOTTOM OUT IN THE LOWER 30S. LONG RANGE...TUESDAY THROUGH FRIDAY...RIDGING ALOFT WILL BUILD INTO THE INTER MOUNTAIN WEST AND CENTRAL CONUS NEXT WEEK. THE RIDGE WILL AMPLIFY FURTHER BY THE END OF THE WEEK WITH VERY WARM AIR PUSHING INTO THE REGION. GUIDANCE TEMPERATURES HAVE TRENDED HIGHER THIS MORNING AND ARE HINTING AT 60S BY THE END OF NEXT WEEK. DECIDED TO TREND TEMPS HIGHER IN THE EXTENDED...BUT NOT AS WARM AS THE OPERATIONAL ECM AND MEX GUIDANCE IS INDICATING. THE ENSEMBLE SPREADS FOR TEMPS AFTER MIDWEEK NEXT WEEK BEGIN TO INCREASE...PARTICULARLY ON THURSDAY AND FRIDAY. WITH THIS IN MIND...WILL TAKE A MORE CONSERVATIVE APPROACH TO INCREASING HIGHS WITH THIS FCST PACKAGE. FWIW...H85 TEMPS THURSDAY AFTERNOON PEAK OUT AT AROUND 16 TO 18C ACROSS FAR SWRN NEBRASKA PER THE LATEST GFS AND ECMWF SOLNS. IF THIS VERIFIES...WE COULD SEE HIGHS NEXT THURSDAY APPROACHING THE 70 DEGREE MARK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 533 PM CST FRI FEB 12 2016 VFR CIGS ACROSS NCNTL NEB SHOULD FILL IN AND BECOME IFR IN LIGHT- FZDZSN AS UPSLOPE WINDS BECOME SOUTH AND SOUTHEAST THIS EVENING. MVFR/IFR CIGS ARE EXPECTED ELSEWHERE. THE RAP MODEL APPEARED TO HAVE THE BEST HANDLE ON THE PCPN. MVFR/IFR CIGS ARE EXPECTED SATURDAY. LIGHT -FZDZSN IS POSSIBLE AGAIN AS A WARM FRONT SHARPENS UP ACROSS WRN NEB. THE GFS LOOKED THE BEST IN THIS REGARD. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SPRINGER SHORT TERM...SPRINGER LONG TERM...BUTTLER AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1147 AM CST THU FEB 11 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CST THU FEB 11 2016 SATELLITE AND OBSERVATIONS SHOW STRATUS THAT HAS BEEN MOVING TO THE SOUTH ACROSS THE FORECAST AREA OVERNIGHT. SO FAR IT HAS MADE IT ACROSS MOST OF THE NEBRASKA PORTION OF THE FORECAST AREA AND WILL BE MOVING INTO THE KANSAS PORTION. THE FIRST CONCERN WITH THIS IS THERE WAS QUITE A BIT OF SNOW MELTING YESTERDAY SO THERE IS GOOD LOW LEVEL MOISTURE. WINDS HAVE BEEN FROM THE NORTH AND FAIRLY LIGHT. WITH THE EDGE OF THE STRATUS ACROSS THE AREA THERE COULD BE A LITTLE FOG. THE HRRR AND THE SREF BOTH HAVE THE LOWEST VISIBILITIES IN THE WEST. SO FAR THERE HAS BEEN LITTLE INDICATION OF ANY FOG. WILL KEEP SOME MENTION OF PATCHY FOG WITH A FEW AREAS OF FOG IN THE FAR WEST. WILL HAVE TO WATCH TO SEE IF THE VISIBILITY DROPS AS WE GET CLOSER TO SUNRISE. THE MAIN DIFFERENCE SEEMS TO BE THE MODELS THAT BRING THE LOWEST VISIBILITIES ALSO HAVE EASTERLY WINDS AND THE CURRENT WINDS ARE MORE NORTH. THERE COULD BE A LITTLE OF THE PATCHY FOG THAT LINGERS INTO THE MORNING HOURS. THE CLOUDS SHOULD HANG AROUND FOR MUCH OF THE DAY...BUT TOWARD THE END OF THE DAY THE CLOUDS SHOULD START TO RECEDE TO THE EAST AGAIN. TEMPERATURES WILL BE A LITTLE COOLER TODAY THAN YESTERDAY. ANOTHER WEAK COLD FRONT WILL MOVE THROUGH THE FORECAST AREA LATE THIS AFTERNOON AND EVENING. THIS SHOULD HELP TO MOVE THE CLOUDS OUT OF THE AREA...BUT TEMPERATURES WILL NOT BE VERY COLD BEHIND THE FRONT TONIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 350 AM CST THU FEB 11 2016 THE END OF THE WORK WEEK WILL BE SLIGHTLY COOLER AS SURFACE HIGH PRESSURE MOVES EAST ACROSS THE AREA. WINDS WILL BECOME SOUTHERLY FRIDAY NIGHT. THE PLAINS SITS UNDER NORTHWESTERLY UPPER LEVEL FLOW AND A DISTURBANCE WILL MOVE SOUTH INTO THE UPPER TROUGH OVER THE EAST CAUSING A CHANCE FOR LIGHT PRECIPITATION OVERNIGHT FRIDAY AND INTO SATURDAY. CONFIDENCE IS NOT OVERLY HIGH...THE LOWEST LEVELS REMAIN THE MOST SATURATED...BUT EARLY ON THERE IS ENOUGH DEPTH AND IT IS COLD ENOUGH TO BEGIN AS SNOW BEFORE FREEZING DRIZZLE LOOKS TO BE THE MAIN PRECIP TYPE. NOT EXPECTING MUCH IN THE WAY OF SNOW ACCUMULATION. DRYER AIR WILL MOVE IN FROM THE NORTHEAST ALLOWING OVERNIGHT TEMPERATURES FRIDAY NIGHT TO PLUMMET INTO THE SINGLE DIGITS AND TEENS...THE COLDEST NIGHT OF THE FORECAST. A MORE POTENT DISTURBANCE WILL DIVE ACROSS THE CENTRAL PLAINS SATURDAY NIGHT WHICH WILL AID IN THE DEVELOPMENT OF PRECIPITATION. THE BEST CHANCES FOR PRECIP LOOK TO BE OVER NORTH AND EASTERN NEBRASKA...BUT SOME LIGHT PRECIP MAY OCCUR OVER SOUTH CENTRAL NEBRASKA. THE COLUMN OF AIR WILL BE COLD ENOUGH FOR SNOW TO BE THE MAIN PRECIP TYPE WITH THIS. SUNDAY AFTER THIS DISTURBANCE MOVES OVERHEAD THE ASSOCIATED FRONT WILL CAUSE WINDS TO BECOME WESTERLY TO NORTHWESTERLY. DOWNSLOPE FLOW WILL AID TEMPERATURES TO RISE BACK INTO THE 40S ACROSS THE AREA. ANOTHER BRIEF DISTURBANCE WILL MOVE OVERHEAD SUNDAY NIGHT...THIS COULD BRING ANOTHER BRIEF CHANCE FOR PRECIP...BUT CONFIDENCE IS LOW ON THIS FEATURE. THE FIRST HALF OF THE WORK WEEK WILL HAVE A WARMING TREND AS UPPER LEVEL RIDGING BUILDS INTO THE AREA. TEMPERATURES WILL WARM EACH DAY FROM MONDAY THROUGH WEDNESDAY WITH HIGHS REACHING INTO THE 50S BY MID WEEK. && .AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1130 AM CST THU FEB 11 2016 PLENTY OF LOW LEVEL STRATUS WILL CONTINUE TO STREAM ACROSS THE REGION THROUGH THE SHORT TERM PERIODS. EXPECT IFR CIGS TO LIFT TO MVFR LEVELS LATE THIS AFTERNOON...ONLY TO DROP BACK DOWN TO IFR LEVELS DURING THE EVENING HOURS. WHILE MODELS ONCE AGAIN ARE INDICATING WE COULD SEE SOME LOWERED VSBYS...OPTED TO ONLY INCLUDE MVFR VSBYS FOR THE TIME BEING AS CONDITIONS DO NOT LOOK ANY MORE FAVORABLE FOR FOG DEVELOPMENT OVERNIGHT THAN THEY DID THIS MORNING. OTHERWISE...EXPECT WINDS TO SHIFT AND BECOME MORE NORTHERLY OVERNIGHT AS A COLD FRONT DROPS SOUTH ACROSS THE REGION...GENERALLY REMAINING 12KTS OF LESS THROUGH THE PERIOD. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...JCB LONG TERM...BILLINGS WRIGHT AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
524 AM CST THU FEB 11 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CST THU FEB 11 2016 SATELLITE AND OBSERVATIONS SHOW STRATUS THAT HAS BEEN MOVING TO THE SOUTH ACROSS THE FORECAST AREA OVERNIGHT. SO FAR IT HAS MADE IT ACROSS MOST OF THE NEBRASKA PORTION OF THE FORECAST AREA AND WILL BE MOVING INTO THE KANSAS PORTION. THE FIRST CONCERN WITH THIS IS THERE WAS QUITE A BIT OF SNOW MELTING YESTERDAY SO THERE IS GOOD LOW LEVEL MOISTURE. WINDS HAVE BEEN FROM THE NORTH AND FAIRLY LIGHT. WITH THE EDGE OF THE STRATUS ACROSS THE AREA THERE COULD BE A LITTLE FOG. THE HRRR AND THE SREF BOTH HAVE THE LOWEST VISIBILITIES IN THE WEST. SO FAR THERE HAS BEEN LITTLE INDICATION OF ANY FOG. WILL KEEP SOME MENTION OF PATCHY FOG WITH A FEW AREAS OF FOG IN THE FAR WEST. WILL HAVE TO WATCH TO SEE IF THE VISIBILITY DROPS AS WE GET CLOSER TO SUNRISE. THE MAIN DIFFERENCE SEEMS TO BE THE MODELS THAT BRING THE LOWEST VISIBILITIES ALSO HAVE EASTERLY WINDS AND THE CURRENT WINDS ARE MORE NORTH. THERE COULD BE A LITTLE OF THE PATCHY FOG THAT LINGERS INTO THE MORNING HOURS. THE CLOUDS SHOULD HANG AROUND FOR MUCH OF THE DAY...BUT TOWARD THE END OF THE DAY THE CLOUDS SHOULD START TO RECEDE TO THE EAST AGAIN. TEMPERATURES WILL BE A LITTLE COOLER TODAY THAN YESTERDAY. ANOTHER WEAK COLD FRONT WILL MOVE THROUGH THE FORECAST AREA LATE THIS AFTERNOON AND EVENING. THIS SHOULD HELP TO MOVE THE CLOUDS OUT OF THE AREA...BUT TEMPERATURES WILL NOT BE VERY COLD BEHIND THE FRONT TONIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 350 AM CST THU FEB 11 2016 THE END OF THE WORK WEEK WILL BE SLIGHTLY COOLER AS SURFACE HIGH PRESSURE MOVES EAST ACROSS THE AREA. WINDS WILL BECOME SOUTHERLY FRIDAY NIGHT. THE PLAINS SITS UNDER NORTHWESTERLY UPPER LEVEL FLOW AND A DISTURBANCE WILL MOVE SOUTH INTO THE UPPER TROUGH OVER THE EAST CAUSING A CHANCE FOR LIGHT PRECIPITATION OVERNIGHT FRIDAY AND INTO SATURDAY. CONFIDENCE IS NOT OVERLY HIGH...THE LOWEST LEVELS REMAIN THE MOST SATURATED...BUT EARLY ON THERE IS ENOUGH DEPTH AND IT IS COLD ENOUGH TO BEGIN AS SNOW BEFORE FREEZING DRIZZLE LOOKS TO BE THE MAIN PRECIP TYPE. NOT EXPECTING MUCH IN THE WAY OF SNOW ACCUMULATION. DRYER AIR WILL MOVE IN FROM THE NORTHEAST ALLOWING OVERNIGHT TEMPERATURES FRIDAY NIGHT TO PLUMMET INTO THE SINGLE DIGITS AND TEENS...THE COLDEST NIGHT OF THE FORECAST. A MORE POTENT DISTURBANCE WILL DIVE ACROSS THE CENTRAL PLAINS SATURDAY NIGHT WHICH WILL AID IN THE DEVELOPMENT OF PRECIPITATION. THE BEST CHANCES FOR PRECIP LOOK TO BE OVER NORTH AND EASTERN NEBRASKA...BUT SOME LIGHT PRECIP MAY OCCUR OVER SOUTH CENTRAL NEBRASKA. THE COLUMN OF AIR WILL BE COLD ENOUGH FOR SNOW TO BE THE MAIN PRECIP TYPE WITH THIS. SUNDAY AFTER THIS DISTURBANCE MOVES OVERHEAD THE ASSOCIATED FRONT WILL CAUSE WINDS TO BECOME WESTERLY TO NORTHWESTERLY. DOWNSLOPE FLOW WILL AID TEMPERATURES TO RISE BACK INTO THE 40S ACROSS THE AREA. ANOTHER BRIEF DISTURBANCE WILL MOVE OVERHEAD SUNDAY NIGHT...THIS COULD BRING ANOTHER BRIEF CHANCE FOR PRECIP...BUT CONFIDENCE IS LOW ON THIS FEATURE. THE FIRST HALF OF THE WORK WEEK WILL HAVE A WARMING TREND AS UPPER LEVEL RIDGING BUILDS INTO THE AREA. TEMPERATURES WILL WARM EACH DAY FROM MONDAY THROUGH WEDNESDAY WITH HIGHS REACHING INTO THE 50S BY MID WEEK. && .AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 521 AM CST THU FEB 11 2016 LOW STRATUS WILL CONTINUE ACROSS THE AREA THROUGH MUCH OF THE PERIOD. THE LOWEST CEILINGS WILL BE EARLY THIS MORNING THEN CEILINGS WILL INCREASE A LITTLE AND THERE COULD BE A FEW IN AND OUT PERIODS DURING THE AFTERNOON. HAVE SEEN LITTLE IN THE WAY OF FOG THIS MORNING SO HAVE LEFT IT OUT FOR NOW. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...JCB LONG TERM...BILLINGS WRIGHT AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
350 AM CST THU FEB 11 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CST THU FEB 11 2016 SATELLITE AND OBSERVATIONS SHOW STRATUS THAT HAS BEEN MOVING TO THE SOUTH ACROSS THE FORECAST AREA OVERNIGHT. SO FAR IT HAS MADE IT ACROSS MOST OF THE NEBRASKA PORTION OF THE FORECAST AREA AND WILL BE MOVING INTO THE KANSAS PORTION. THE FIRST CONCERN WITH THIS IS THERE WAS QUITE A BIT OF SNOW MELTING YESTERDAY SO THERE IS GOOD LOW LEVEL MOISTURE. WINDS HAVE BEEN FROM THE NORTH AND FAIRLY LIGHT. WITH THE EDGE OF THE STRATUS ACROSS THE AREA THERE COULD BE A LITTLE FOG. THE HRRR AND THE SREF BOTH HAVE THE LOWEST VISIBILITIES IN THE WEST. SO FAR THERE HAS BEEN LITTLE INDICATION OF ANY FOG. WILL KEEP SOME MENTION OF PATCHY FOG WITH A FEW AREAS OF FOG IN THE FAR WEST. WILL HAVE TO WATCH TO SEE IF THE VISIBILITY DROPS AS WE GET CLOSER TO SUNRISE. THE MAIN DIFFERENCE SEEMS TO BE THE MODELS THAT BRING THE LOWEST VISIBILITIES ALSO HAVE EASTERLY WINDS AND THE CURRENT WINDS ARE MORE NORTH. THERE COULD BE A LITTLE OF THE PATCHY FOG THAT LINGERS INTO THE MORNING HOURS. THE CLOUDS SHOULD HANG AROUND FOR MUCH OF THE DAY...BUT TOWARD THE END OF THE DAY THE CLOUDS SHOULD START TO RECEDE TO THE EAST AGAIN. TEMPERATURES WILL BE A LITTLE COOLER TODAY THAN YESTERDAY. ANOTHER WEAK COLD FRONT WILL MOVE THROUGH THE FORECAST AREA LATE THIS AFTERNOON AND EVENING. THIS SHOULD HELP TO MOVE THE CLOUDS OUT OF THE AREA...BUT TEMPERATURES WILL NOT BE VERY COLD BEHIND THE FRONT TONIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 350 AM CST THU FEB 11 2016 THE END OF THE WORK WEEK WILL BE SLIGHTLY COOLER AS SURFACE HIGH PRESSURE MOVES EAST ACROSS THE AREA. WINDS WILL BECOME SOUTHERLY FRIDAY NIGHT. THE PLAINS SITS UNDER NORTHWESTERLY UPPER LEVEL FLOW AND A DISTURBANCE WILL MOVE SOUTH INTO THE UPPER TROUGH OVER THE EAST CAUSING A CHANCE FOR LIGHT PRECIPITATION OVERNIGHT FRIDAY AND INTO SATURDAY. CONFIDENCE IS NOT OVERLY HIGH...THE LOWEST LEVELS REMAIN THE MOST SATURATED...BUT EARLY ON THERE IS ENOUGH DEPTH AND IT IS COLD ENOUGH TO BEGIN AS SNOW BEFORE FREEZING DRIZZLE LOOKS TO BE THE MAIN PRECIP TYPE. NOT EXPECTING MUCH IN THE WAY OF SNOW ACCUMULATION. DRYER AIR WILL MOVE IN FROM THE NORTHEAST ALLOWING OVERNIGHT TEMPERATURES FRIDAY NIGHT TO PLUMMET INTO THE SINGLE DIGITS AND TEENS...THE COLDEST NIGHT OF THE FORECAST. A MORE POTENT DISTURBANCE WILL DIVE ACROSS THE CENTRAL PLAINS SATURDAY NIGHT WHICH WILL AID IN THE DEVELOPMENT OF PRECIPITATION. THE BEST CHANCES FOR PRECIP LOOK TO BE OVER NORTH AND EASTERN NEBRASKA...BUT SOME LIGHT PRECIP MAY OCCUR OVER SOUTH CENTRAL NEBRASKA. THE COLUMN OF AIR WILL BE COLD ENOUGH FOR SNOW TO BE THE MAIN PRECIP TYPE WITH THIS. SUNDAY AFTER THIS DISTURBANCE MOVES OVERHEAD THE ASSOCIATED FRONT WILL CAUSE WINDS TO BECOME WESTERLY TO NORTHWESTERLY. DOWNSLOPE FLOW WILL AID TEMPERATURES TO RISE BACK INTO THE 40S ACROSS THE AREA. ANOTHER BRIEF DISTURBANCE WILL MOVE OVERHEAD SUNDAY NIGHT...THIS COULD BRING ANOTHER BRIEF CHANCE FOR PRECIP...BUT CONFIDENCE IS LOW ON THIS FEATURE. THE FIRST HALF OF THE WORK WEEK WILL HAVE A WARMING TREND AS UPPER LEVEL RIDGING BUILDS INTO THE AREA. TEMPERATURES WILL WARM EACH DAY FROM MONDAY THROUGH WEDNESDAY WITH HIGHS REACHING INTO THE 50S BY MID WEEK. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1120 PM CST WED FEB 10 2016 STRATUS CONTINUES TO PUSH SOUTH INTO THE TERMINAL AREAS IN THE NEXT FEW HOURS. EXPECT THE LOWEST CEILINGS TO BE A FEW HOURS EITHER SIDE OF SUNRISE. CEILINGS SHOULD INCREASE A LITTLE DURING THE DAY...BUT THE STRATUS SHOULD LINGER THROUGH MUCH OF THE PERIOD. DUE TO SNOW MELT TODAY...LIGHT WINDS AND THE EDGE OF THE STRATUS AROUND THE AREA...THERE COULD BE SOME FOG. THE LOCATION AND HOW DENSE IT GETS IS STILL IN QUESTION AT THIS TIME. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...JCB LONG TERM...BILLINGS WRIGHT AVIATION...JCB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
333 AM CST THU FEB 11 2016 .SYNOPSIS... ISSUED AT 333 AM CST THU FEB 11 2016 A BACKDOOR COLD FRONT HAS USHERED IN STRATUS ACROSS THE NORTHEASTERN HALF OF THE FA. SOME LIGHT FOG INDICATED AT THEDFORD AND PINE RIDGE AS OF 08Z. TEMPERATURES RANGING FROM THE MID 20S TO LOW 30S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CST THU FEB 11 2016 THE MAIN FORECAST CONCERNS WILL BE A DISTURBANCE DROPPING SOUTHEAST FROM THE DAKOTAS INTO NORTHEAST NEBRASKA TODAY AND THE EFFECTS THIS HAS ON HIGH TEMPERATURES. SURFACE LOW PRESSURE ON THE SOUTHWEST SIDE OF THE DISTURBANCE WILL VEER SURFACE WINDS TO THE WEST AND NORTHWEST ACROSS THE WESTERN HALF OF THE FA AND ALLOWING HIGHS TO RISE TO 45 TO 50 DEGREES. THE MORNING STRATUS SHOULD BREAK UP IN THE AFTERNOON WITH MAINLY HIGH CLOUDINESS LINGERING. FURTHER EAST...HIGHS FROM THE MID 30S TO LOW 40S AFFECTED BY SOUTHERLY WINDS AND PERSISTENT STRATUS. HAVE INTRODUCED A 20-30 POP ACROSS BOYD COUNTY AND FAR NRN HOLT COUNTY MAINLY BETWEEN 10 AM AND 3 PM ON THE FAR WESTERN EDGE OF THE DISTURBANCE. FOR TONIGHT...AN ARCTIC HIGH WILL BEGIN TO BUILD INTO THE REGION WITH STRATUS LIKELY TO PUSH BACK INTO WESTERN NEBRASKA. THERE COULD BE SOME VERY LIGHT PRECIPITATION AFTER MIDNIGHT AND SOUNDING PROFILES FAVOR SOME CHANCE FOR FREEZING DRIZZLE. HAVE NOT INTRODUCED MENTION YET...AND IF IT WOULD OCCUR IT WOULD FAVOR AREAS ACROSS THE NORTHEAST HALF OF THE FA. LOWS TONIGHT FROM THE UPPER 20S CENTRAL SANDHILLS AND SOUTHWEST TO NEAR 25 NORTH. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 333 AM CST THU FEB 11 2016 ARCTIC HIGH PRESSURE WILL BUILD SOUTHEAST ACROSS THE NORTHERN PLAINS ON FRIDAY AND WILL FORCE A FRONT SOUTHWEST ACROSS THE SANDHILLS. THE FORECAST CALLS FOR MUCH COOLER TEMPERATURES FRIDAY AFTERNOON...WITH HIGHS RANGING FROM THE MID TO UPPER 20S ACROSS OUR FAR NORTHEASTERN ZONES...TO NEAR 40 OVER THE HIGHEST TERRAIN OF THE SOUTHWEST. THE FRONT STALLS FRIDAY EVENING ACROSS SOUTHWEST NEB AND THE PANHANDLE AS A WEAK AREA OF MID LEVEL WARM AIR ADVECTION LIFTS EAST ATOP THE FRONT. PROXIMITY SOUNDINGS ACROSS THE SANDHILLS AND EASTERN PANHANDLE INITIALLY REVEAL SUFFICIENT MOISTURE AND FAVORABLE THERMAL PROFILES FOR ALL SNOW...BUT INTO THE OVERNIGHT SOUNDINGS FAVOR MORE LIGHT FREEZING DRIZZLE OVER SNOW. THE FOCUS OF THE DRIZZLE WILL SPREAD EAST TOWARD DAWN AND ON SATURDAY AS A WARM FRONT PUSHES EAST ACROSS THE SANDHILLS. TEMPERATURES ON SATURDAY WILL MODERATE SLIGHTLY BEHIND THE WARM FRONT...WITH HIGHS ANTICIPATED TO TOP OUT IN THE LOWER TO MID 40S ACROSS SW NEB AND THE EASTERN PANHANDLE. ACROSS NORTH CENTRAL NEBRASKA...THE LATEST GUIDANCE INDICATES HIGHS OF ONLY THE MID 20S. THE NEXT POTENTIAL PRECIPITATION PRODUCER ARRIVES OVER NORTHERN NEBRASKA SATURDAY NIGHT. THE BEST LIFT GENERALLY IS INDICATED ACROSS THE DAKOTAS...BUT THE ECMWF CONTINUES TO PUT DOWN QPF ACROSS THE NORTHERN ZONES. WILL RETAIN THE SLIGHT CHANCE TO LOW END CHANCE POPS ACROSS OUR NORTH. FOR SUNDAY AND BEYOND...THE SYSTEM EJECTS TO THE EAST...BUT FAVORABLE UPPER LEVEL DYNAMICS FOR ADDITIONAL LIGHT QPF CHANCES REMAIN ACROSS THE REGION. WARMING TEMPERATURES THOUGH ARE LIKELY AS LOWER AND MID LEVEL WAA SPREADS EAST FROM THE ROCKY MOUNTAIN WEST. BEYOND SUNDAY THE WARMING TEMPERATURES CONTINUE WITH HIGHS APPROACHING 60 SOUTH OF I80 BY TUESDAY. THE WARM TEMPERATURES LOOK TO REMAIN THROUGH AT LEAST MID-WEEK AS RIDGING PREVAILS TO THE WEST OF THE CWA. ARCTIC HIGH PRESSURE IS SHOWN TO DROP SOUTHEAST FROM THE CANADIAN PRAIRIES MID-WEEK...BUT THE GFS AND ECMWF ARE AT ODDS AS TO HOW FAR WEST THE COOL AIR BUILDS. FOR NOW WILL NOT MAKE ANY CHANGES TO THE BLENDED EXTENDED PROCEDURE...WHICH SUGGEST THE WARMER TEMPERATURES. PRECIPITATION CHANCES WILL BE LIMITED BEYOND SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1126 PM CST WED FEB 10 2016 THE RAP MODEL HAS DONE WELL WITH THE MVFR/IFR CIGS MOVING INTO NEB THIS EVENING AND IT IS THE BASIS FOR THE FORECAST. THE MODEL IS SIMILAR TO THE FASTER GFS AND SUGGESTS MOST OF THE FCST AREA WOULD BE VFR BY 22Z THURSDAY. LIFR IS POSSIBLE FOG OVERNIGHT ALONG I-80 AND HIGHWAY 61. MVFR/IFR IS GENERALLY EXPECTED FROM 16Z-20Z. MVFR CIGS MOVE IN AGAIN THURSDAY EVENING WITH THE NEXT ARCTIC FRONT. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...ROBERG SHORT TERM...ROBERG LONG TERM...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1126 PM CST WED FEB 10 2016 .SYNOPSIS... ISSUED AT 324 PM CST WED FEB 10 2016 MILD AIR HAS PUSHED INTO ALL OF WESTERN AND NORTH CENTRAL NEBRASKA THIS AFTERNOON AS THE ARCTIC FRONT HAS RETREATED EAST...ALL THE WAY TO FAR NORTHEASTERN NEBRASKA. WITH CLEAR SKIES AND WESTERLY WINDS...TEMPERATURES HAVE SURGED INTO THE UPPER 50S TO LOWER 60S OVER NON SNOW COVERED AREAS OF THE CENTRAL SANDHILLS AND PORTIONS OF NORTH CENTRAL NEBRASKA. OVER SNOW COVERED AREAS...TEMPERATURES WERE IN THE UPPER 40S TO LOWER 50S. THE H5 PATTERN TODAY REMAINED HIGHLY AMPLIFIED...AND HAS SHIFTED 100 TO 200 MILES FURTHER EAST TDY. RIDGING EXTENDED FROM SRN NEVADA...NORTH INTO SRN YUKON WHILE A TROUGH EXTENDED FROM THE NRN GREAT LAKES...SOUTH TO EASTERN PORTIONS OF THE GULF OF MEXICO AND SRN FLORIDA. IN BETWEEN THE TROUGH AND RIDGE...A TIGHT NWRLY H5 GRADIENT WAS NOTED AND EXTENDED FROM SASKATCHEWAN INTO THE BOOT HEEL OF MISSOURI. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 324 PM CST WED FEB 10 2016 TEMPS IN THE 50S AND 60S TODAY HAVE RESULTED IN SOME DECENT SNOW MELT. MEANWHILE A BACK DOOR COLD FRONT WILL DRIFT SW INTO THE REGION. THIS FRONT WILL STALL ACROSS CENTRAL NEBRASKA. THIS WILL CREATE SOME CONCERNS FOR TEMPS...AS WARM TEMPS TO THE WEST OF THE FRONT AND COOL TEMPS TO THE EAST. FOR NOW WILL MODEL BLEND THE LOCATION OF THE FRONT...WITH THE WEST AND SNOW FREE AREAS TO WARM TOMORROW AFTERNOON TO NEAR 50. LIKELY GOING TO HOLD IN THE 30S TO AROUND 40 IN THE EAST. FOR TONIGHT WILL AGAIN BE FOLLOWING THE MEANDERING FRONT. SOME SATURATION AND WEAK LIFT IN THE BL COULD BE ENOUGH FOR SOME FREEZING DRIZZLE ALONG AND EAST OF THE FRONT. THIS WILL MAINLY IMPACT N CENTRAL...ALTHOUGH CONFIDENCE IS LOW SO ONLY INCLUDED PATCHY WORDING. ELSEWHERE...THE ADDED MOISTURE IN THE BL FROM THE SNOW MELT SHOULD CREATE A RICH ENVIRONMENT FOR AT LEAST PATCHY FOG. WILL HAVE TO MONITOR FOR POSSIBLE PATCHY DENSE FOG. DEW PTS HAVE INCREASED INTO THE LOWER 30S...WHILE EXPECTED LOW TEMPS TONIGHT IN THE LOWER TO MID 20S. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 324 PM CST WED FEB 10 2016 MID TERM...THURSDAY NIGHT THROUGH SATURDAY...A COUPLE OF FORECAST CONCERNS HIGHLIGHT THE MID RANGE. THE FIRST IS TEMPERATURES...PARTICULARLY ON FRIDAY THROUGH SATURDAY...THEN THE THREAT FOR LIGHT SNOW FRIDAY...FOLLOWED BY A FREEZING DRIZZLE/LIGHT SNOW THREAT FOR LATE FRIDAY NIGHT INTO SATURDAY. FOR THURSDAY NIGHT...THE ARCTIC FRONT WILL BE ORIENTED ACROSS THE FAR NERN CWA. SURFACE LOW PRESSURE WILL TRACK ALONG THIS FRONT FROM WEST CENTRAL SOUTH DAKOTA INTO NERN NEBRASKA THURSDAY EVENING. AS THE LOW APPROACHES...WEAK LIFT ALONG THE FRONT WILL BE PRESENT IN BOYD AND NERN HOLT COUNTIES. WITH THIS IN MIND...DECIDED TO PLACE SOME SLIGHT CHANCE POPS FOR SNOW IN THESE AREAS. THE FRONT WILL SURGE NORTHEAST AHEAD OF THE LOWS TRACK...THEN QUICKLY SURGE SOUTHWEST OVERNIGHT AS THE SURFACE LOW TRACKS INTO SERN NEBRASKA. ARCTIC HIGH PRESSURE WILL BEGIN TO BUILD INTO THE EASTERN DAKOTAS LATE THURSDAY NIGHT INTO FRIDAY...FORCING THE ARCTIC FRONT SOUTHWEST INTO WESTERN AND NORTH CENTRAL NEBRASKA. BY FRIDAY EVENING...THE FRONT WILL BE ORIENTED ACROSS THE PANHANDLE. HIGHS WERE LOWERED SIGNIFICANTLY FOR FRIDAY AS THE FRONTAL TIMING IS NOW 6 TO 12 HRS EARLIER THAN WHAT WAS INDICATED WITH YESTERDAY/S MODEL SOLNS. THAT BEING SAID...WITH THE COMBINATION OF CLOUDS AND EASTERLY WINDS...HIGHS FRIDAY WILL BE STUCK IN THE 20S AND 30S. ON FRIDAY EVENING...THE FRONT WILL STALL ACROSS WESTERN NEBRASKA TEMPORARILY BEFORE TRACKING SLOWLY EAST OVERNIGHT. AT THE SAME TIME...A WEAK AREA OF MID LEVEL WARM AIR ADVECTION WILL LIFT EAST OVER THE FRONT AS A H750 WARM FRONT BEGINS TO PUSH INTO WESTERN PORTIONS OF THE FORECAST AREA. THERMAL PROFILES INITIALLY SUPPORT ALL SNOW FRIDAY NIGHT EAST OF THE PANHANDLE AND FIRST TIER OF COUNTIES FROM MERRIMAN TO HAYES CENTER. HOWEVER...WEST OF THIS LINE...FCST SOUNDINGS ARE INDICATIVE OF SOME FREEZING DRIZZLE POTENTIAL. THIS FREEZING DRIZZLE POTENTIAL WILL SPREAD EAST SATURDAY AS THE WARM FRONT PUSHES EAST ACROSS THE FORECAST AREA. BY SATURDAY AFTERNOON THE FZDZ THREAT WILL LIE PRIMARILY EAST OF A AINSWORTH TO TAYLOR LINE. HIGHS SATURDAY WILL RANGE FROM THE MID 20S IN THE FAR NORTHEASTERN CWA...TO LOWER 40S IN THE EASTERN PANHANDLE AND FAR SWRN NEBRASKA. LONG RANGE...SATURDAY NIGHT THROUGH WEDNESDAY...ON SATURDAY NIGHT...AN EMBEDDED SHORTWAVE WILL LIFT ACROSS THE DAKOTAS AND NORTHERN NEBRASKA. THE INHERITED FCST DID HAVE A MENTION OF LIGHT PCPN ACROSS THE NRN THIRD OF THE FORECAST AREA SAT NIGHT AND THIS WAS RETAINED IN THE CURRENT FORECAST. ON SUNDAY THE UPPER LEVEL SYSTEM WILL TRACK FROM NORTHERN NEBRASKA AND AND THE CENTRAL DAKOTAS INTO THE UPPER MISISSIPPI VALLEY. THERE WILL STILL BE A LIMITED THREAT FOR LIGHT RAIN OR SNOW ACROSS NORTHERN...THEN NORTHEASTERN NEBRASKA SUNDAY. DECIDED TO LEAVE POPS AT SLIGHT CHANCES FOR NOW...AS FORCING IS WEAK AND AVAILABLE MOISTURE IS LIMITED WITH THIS DISTURBANCE. AFTER SUNDAY...TEMPERATURES WILL CONTINUE TO CLIMB INTO MIDWEEK NEXT WEEK WITH HIGHS TRANSITIONING FROM THE 40S MONDAY...TO THE 50S TO AROUND 60 TUESDAY...THEN THE 50S FOR WEDNESDAY. THE PATTERN ALOFT WILL TRANSITION TO MORE OF A ZONAL PATTERN...WHICH WILL ALLOW WARMER PACIFIC AIR TO INFILTRATE THE CENTRAL PLAINS. ANY ARCTIC AIR NEXT WEEK...IS EXPECTED TO REMAIN WELL NORTH OF THE FORECAST AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1126 PM CST WED FEB 10 2016 THE RAP MODEL HAS DONE WELL WITH THE MVFR/IFR CIGS MOVING INTO NEB THIS EVENING AND IT IS THE BASIS FOR THE FORECAST. THE MODEL IS SIMILAR TO THE FASTER GFS AND SUGGESTS MOST OF THE FCST AREA WOULD BE VFR BY 22Z THURSDAY. LIFR IS POSSIBLE FOG OVERNIGHT ALONG I-80 AND HIGHWAY 61. MVFR/IFR IS GENERALLY EXPECTED FROM 16Z-20Z. MVFR CIGS MOVE IN AGAIN THURSDAY EVENING WITH THE NEXT ARCTIC FRONT. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BUTTLER SHORT TERM...MASEK LONG TERM...BUTTLER AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1124 PM CST WED FEB 10 2016 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 342 PM CST WED FEB 10 2016 AFTER A SEASONABLY NICE AFTERNOON...EXPECT TEMPERATURES TO RAPIDLY FALL BACK BELOW FREEZING THIS EVENING AS THE SUN GOES DOWN...WITH CLOUDS BEGINNING TO ROLL BACK IN ACROSS THE LOCAL AREA FROM THE NORTHEAST OVERNIGHT. COULD SEE SOME FOG DEVELOPMENT ON THE LEADING EDGE OF THIS STRATUS...AND OPTED TO INTRODUCE THIS INTO THE FORECAST AFTER ABOUT MIDNIGHT TONIGHT. WHILE THE BEST CHANCE FOR THE MORE DENSE FOG IS WEST OF THE LOCAL AREA...THE LATEST RUN OF THE HRRR IS INDICATING THIS MORE DENSE AREA OF FOG COULD AT LEAST CREEP IN ON OUR WESTERN COUNTIES TOWARDS DAYBREAK...AND THIS WILL BE SOMETHING FOR THE EVENING SHIFT TO MONITOR AS NEW MODEL DATA COMES IN. OTHERWISE...EXPECT LITTLE SHIFT IN THE OVERALL SYNOPTIC PATTERN THROUGH THE SHORT TERM PERIODS AS NORTHWESTERLY FLOW ALOFT WILL CONTINUE WITH A WEAK UPPER LEVEL WAVE MAKING ITS WAY OVER THE TOP OF THE UPPER LEVEL RIDGE AND TOWARDS THE LOCAL AREA TOMORROW AFTERNOON. AS THE LOW LEVEL FLOW TURNS MORE EASTERLY AND THEN SOUTHEASTERLY OVERNIGHT...EXPECT THE FRONTAL BOUNDARY TO OUR EAST TO INCH BACK ACROSS THE LOCAL AREA...BRINGING SIGNIFICANT LOW LEVEL STRATUS AND COOLER TEMPERATURES BACK TOWARDS THE REGION TOMORROW...WITH A MOSTLY CLOUDY DAY AND MORE SEASONAL TEMPERATURES EXPECTED FOR TOMORROW AFTERNOON. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 342 PM CST WED FEB 10 2016 MODELS ARE IN GOOD AGREEMENT AT THE START OF THE LONG TERM PERIOD THURSDAY NIGHT LOOKING AT THE OVERALL PICTURE...UPPER LEVEL NWRLY FLOW EXPECTED TO REMAIN IN PLACE ACROSS THE REGION. LOW PRESSURE OVER THE HUDSON BAY AREA KEEPS THE ERN CONUS UNDER BROAD TROUGHING...WHILE A RIDGE OF HIGH PRESSURE EXTENDS NORTH THROUGH THE ROCKIES. AT THIS POINT...KEPT THE FORECAST DRY THURS NIGHT AND FRIDAY...AS MODELS CONTINUE TO KEEP THE BETTER PRECIP CHANCES ASSOCIATED WITH AN UPPER LEVEL JET STREAK JUST OFF TO THE N/NE OF THE CWA. THE MAIN STORY THROUGH FRIDAY LIES WITH THE PASSAGE OF A COLD FRONT...BEING PUSHED SOUTH BY SHORTWAVE ENERGY SWINGING THROUGH TO THE N/NE. WHILE THE SFC PATTERN STARTS THE PERIOD OUT FAIRLY RELAXED...THIS FRONT WITH USHER IN NRLY WINDS BY SUNRISE FRIDAY...GRADUALLY TURNING MORE NERLY THROUGH THE DAY. COLDER AIR STARTS TO ADVECT INTO THE CWA...AND DID LOWER FORECAST HIGHS FOR FRIDAY...WITH NEAR 30 NOW IN THE NORTHEAST TO NEAR 40 IN THE SW. CONFIDENCE IN THIS WEEKEND...MAINLY REGARDING PRECIP CHANCES/LACK OF...IS NOT HIGH. OVERALL UPPER LEVEL REMAIN LOOKS TO REMAIN NORTHWESTERLY...BUT THERE IS BETTER POTENTIAL FOR THE CWA TO BE AFFECTED BY SHORTWAVE ENERGY MOVING THROUGH THE MAIN FLOW. LATE FRIDAY NIGHT INTO SATURDAY MORNING IS THE FIRST SHOT OF THIS ENERGY MOVING THROUGH...WITH MODELS ALSO SHOWING THE CWA SITTING ON THE ERN EDGE OF A 25-30KT LLJ SITTING OVER THE HIGH PLAINS. MODELS HINTING AT THE POTENTIAL FOR SOME LIGHT PRECIPITATION AFFECTING MAINLY WRN AND NRN PORTIONS OF THE CWA...WITH FORECAST SOUNDINGS DIFFERING SOME WITH THE OVERALL THICKNESS OF THE SATURATED LAYER...LEAVING THE QUESTION WHETHER THERE WOULD BE ANYTHING MEASURABLE...OR IF IT WOULD BE MORE FZDZ OR FLURRIES. HAVE A 20 POP/SNOW GOING AS WELL AS A SLGT CHANCE FOR FZDZ. ONLY KEPT THE MENTION GOING THROUGH THE FIRST HALF OF THE DAY...THOUGH IF YOU BELIEVE THE NAM QPF FIELDS THERE WOULD BE SOMETHING AROUND ALL DAY SATURDAY. AS FAR AS TEMPERATURES GO...SATURDAY STILL FORECAST TO BE THE COLDEST DAY OF THE LONG TERM PERIOD. BY SUNRISE SATURDAY...SFC HIGH PRESSURE IS EXPECTED TO BE LOCATED OVER NERN IA...WITH ERN PORTIONS OF THE CWA NOT TOO FAR AWAY FROM DOUBLE DIGIT BELOW ZERO TEMPS AT 850MB. EVEN WITH THE BRUNT OF THE COLDEST AIR OFF TO OUR EAST...FORECAST HIGHS CURRENTLY RANGE FROM NEAR 20 IN THE NORTHEAST TO LOWER 30S IN THE SW. LOOKING TO SUNDAY...THE FORECAST IS DRY...BUT AS MENTIONED ABOVE CONFIDENCE IS NOT HIGH. MODELS SHOW THE POTENTIAL FOR 1 /PERHAPS 2/ WEAK WAVES TO MOVE THROUGH THE PLAINS THROUGH SUNDAY NIGHT...JUST SOME DIFFERENCES IN LOCATION. WILL SEE HOW THINGS TREND BEFORE INSERTING POPS. EXPECTING TO SEE REBOUNDING TEMPS FOR SUNDAY AS THAT COLDER AIR PUSHES EAST AND WARMER TEMPS START TO BUILD IN...WITH 40S CURRENTLY FORECAST FOR MOST OF THE CWA. THROUGH THE FIRST HALF OF THE NEXT WORK WEEK...THE FORECAST REMAINS DRY...WITH MODELS IN PRETTY GOOD AGREEMENT SHOWING BROAD UPPER LEVEL RIDGING TAKING OVER THE WRN CONUS AND GRADUALLY BUILDING EAST. NICE WARM UP CURRENTLY GOING IN THE FORECAST...WITH 50S FORECAST FOR TUE/WED. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1120 PM CST WED FEB 10 2016 STRATUS CONTINUES TO PUSH SOUTH INTO THE TERMINAL AREAS IN THE NEXT FEW HOURS. EXPECT THE LOWEST CEILINGS TO BE A FEW HOURS EITHER SIDE OF SUNRISE. CEILINGS SHOULD INCREASE A LITTLE DURING THE DAY...BUT THE STRATUS SHOULD LINGER THROUGH MUCH OF THE PERIOD. DUE TO SNOW MELT TODAY...LIGHT WINDS AND THE EDGE OF THE STRATUS AROUND THE AREA...THERE COULD BE SOME FOG. THE LOCATION AND HOW DENSE IT GETS IS STILL IN QUESTION AT THIS TIME. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...ROSSI LONG TERM...ADP AVIATION...JCB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
302 PM EST THU FEB 11 2016 .SYNOPSIS... LAKE EFFECT SNOW WILL BE HEAVY AT TIMES THROUGH TONIGHT IN PARTS OF CENTRAL NEW YORK...GENERALLY SOUTHEAST OF LAKE ONTARIO. SCATTERED SNOW SHOWERS AND FLURRIES WILL OCCUR ELSEWHERE WITH LIGHT ACCUMULATIONS. A STRONG ARCTIC FRONT WILL DROP THROUGH THE REGION LATE FRIDAY...BRINGING THE COLDEST AIR MASS SINCE LAST WINTER. WIND CHILLS WILL BE DANGEROUSLY LOW...WELL BELOW ZERO...SATURDAY THROUGH SATURDAY NIGHT. A MODERATING TREND IS EXPECTED EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... UPDATED AT 1130 AM... MAIN LAKE EFFECT BANDS CONTINUE E-SE OF LAKE ONTARIO ON ABOUT A 290 FLOW LATE THIS MORNING WITH NUMEROUS SECONDARY WEAKER BANDS FARTHER SOUTH EXTENDING INTO NORTHERN PA. BANDS STILL APPEAR TO BE SHIFTING SLOWLY SOUTH AND ARE NEAR THE THRUWAY LATE THIS MORNING WITH STILL THE POTENTIAL FOR SOME HEAVY BANDS TO GET INTO THE CITIES OF SYRACUSE AND UTICA AT SOME POINT THIS AFTERNOON. STILL EXPECTING SEVERAL INCHES THIS AFTERNOON FROM NORTHERN ONONDAGA COUNTY EAST TO WEST CENTRAL ONEIDA COUNTY WITH LESS TO THE SOUTH. ATMOSPHERE UPSTREAM FROM THESE BANDS IS BECOMING INCREASINGLY DRY AND NO GOOD CONNECTION WITH LAKE HURON / GEORGIAN BAY CAN BE SEEN ON LATEST VISIBLE IMAGERY. ALSO DENDRITIC SNOW GROWTH POTENTIAL IS NOT OPTIMAL AS THE ATMOSPHERE HAS BECOME COLD ENOUGH SO THAT ONLY A SHALLOW LAYER ABOVE -20 C EXISTS BELOW 900 MB. WILL KEEP CURRENT WARNINGS AND ADVISORIES GOING THROUGH THIS AFTERNOON AS SNOW SHOWERS AND BLOWING SNOW WILL MAKE FOR HAZARDOUS TRAVEL... ALTHOUGH WARNING TYPE ACCUMULATIONS LOOK TO REMAIN JUST NORTH OF THE CITY OF SYRACUSE THROUGH TODAY... WITH JUST ANOTHER COUPLE OF INCHES IN THE ADVISORY AREAS TO THE SOUTH. TEMPERATURES ARE ONLY EXPECTED TO RISE A FEW DEGREES FROM CURRENT LEVELS WITH TEENS IN MOST AREAS TO NEAR 20 IN THE LOWER ELEVATIONS OF NORTHERN PA. PREVIOUS DISCUSSION IS BELOW. 315 AM UPDATE... WANTED TO SEND OUT AN "EARLY" UPDATE TO REFLECT ON THE CURRENT SITUATION REGARDING OUR LAKE EFFECT EVENT. WILL SEND OUT A SEPARATE AFD FOR THE SHORT TERM PERIOD TO GO OVER THE DANGEROUS COLD OVER THE WEEKEND. FIRST THINGS FIRST, THE LAKE EFFECT. SEE OUR WEBSITE FOR OUR LATEST SNOWFALL MAP THAT I JUST POSTED. WARNINGS AND ADVISORIES WILL REMAIN IN PLACE. I DID SHIFT THE HEAVIER AXIS OF SNOW FARTHER NORTH, TO REFLECT RADAR TRENDS FROM YESTERDAY EVENING THROUGH NOW. THE CHANGE WILL INCREASE AMOUNTS IN WEST CENTRAL ONEIDA COUNTY QUITE A BIT, WHILE DROPPING OFF SHARPLY TOWARD THE CITY OF UTICA. I KEPT NORTHERN ONONDAGA IN THE HIGHER AMOUNTS AS WELL, ALTHOUGH THEY WILL PROBABLY END UP BEING LOWER OVERALL THAN WEST CENTRAL ONEIDA. THE HIGHER TOTALS ACROSS NORTHERN ONONDAGA COUNTY IS A REFLECTION OF WHAT WE EXPECT TO COME, NOT UNDERSTANDING WE HAVEN`T SEE MUCH SNOW HERE YET. WHILE THE FORECAST GOING FORECAST IS LARGELY UNCHANGED FROM THIS POINT FORWARD, WE HAVEN`T SEE MUCH SNOW AT ALL FROM THE NEAR THE CITY OF SYRACUSE SOUTH. THUS I HAVE ADJUSTED TOTALS DOWN ACROSS SOUTHERN ONONDAGA/MADISON COUNTIES, ALONG WITH NORTHERN CORTLAND/CHENANGO/OTSEGO. WHILE THE BAND HAS BEEN MAINLY NORTH OF KSYR AND HAS EVEN WAVERED BACK INTO NORTHERN ONEIDA, CONFIDENCE IS HIGH THAT THE BAND WILL SINK SOUTH BETWEEN 09Z AND 12Z. THE LATEST HRRR AND RAP SOUNDINGS SHOW A MEAN WIND OF 275 NOW, ABRUPTLY SHIFTING TOWARD 290 BY 12Z, THEN LOCKING IN FOR THE REST OF THE DAY. KBUF RADAR SHOWS THE WESTERN SIDE OF THE BAND NEAR KROC IS ALREADY SHOWING SIGNS OF THIS CHANGE AND WILL FOLLOW. SO WHILE THE EVENT HAS PLAYED OUT WELL THUS FAR ACROSS WEST CENTRAL ONEIDA COUNTY, MANY IN METRO SYRACUSE AND ALONG THE THRUWAY MAY BE WONDERING WHAT LAKE SNOWS? DON`T LET YOUR GUARD DOWN YET AS HEAVIER SNOWS WILL SHIFT SOUTH TODAY. WITH INVERSION HEIGHTS GRADUALLY LOWERING TOWARD 5KFT BY LATE AFTERNOON, THE OVERALL INTENSITY WILL BE HIGHEST THIS MORNING, THEN A GRADUAL WEAKENING TREND INTO EARLY TONIGHT. SNOWFALL RATES THROUGH MID MORNING WILL STILL BE IN THE 1 TO 2"+ RANGE. THE FLOW REMAINS AROUND 290-300 THROUGH 06Z TONIGHT, BEFORE THE FLOW BACKS ENOUGH TOWARD THE SOUTHWEST TO LIFT THE BAND OUT OF OUR AREA TOWARD DAYBREAK FRIDAY. IN ALL A WIDESPREAD, LONG DURATION 6"+ LOOKS GOOD ACROSS MUCH OF CENTRAL NY, WITH CLOSER TO 1 1/2 FEET OVER WESTERN ONEIDA COUNTY. I CONTINUE TO MENTION BLOW AND DRIFTING SNOW WITHIN AND NEAR THE SNOW BANDS THEMSELVES. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... 4 AM UPDATE... OVERVIEW...SNOW SQUALLS LIKELY FRIDAY NIGHT ALONG AN ARCTIC FRONT THAT WILL DELIVER BRUTAL COLD SATURDAY AND SATURDAY NIGHT, WHICH WILL RIVAL WHAT WE SAW LAST FEBRUARY. FRIDAY/FRIDAY NIGHT....MOST OF FRIDAY WILL BE QUIET WITH A SOUTHWEST FLOW AHEAD OF AN ARCTIC FRONT. THIS FLOW WILL KEEP MOST OF THE AREA DRY THROUGH THE DAYLIGHT HOURS. FRIDAY EVENING THE ARCTIC FRONT WILL CROSS THE AREA BETWEEN 0Z AND 06Z SATURDAY. SNOW SQUALLS LOOK LIKELY, WITH THE POTENTIAL FOR POOR VISIBILITY AND SNOWFALL RATES OF MORE THAN AN INCH PER HOUR. MODEL SOUNDINGS SHOW STEEP LAPSE RATES OF MORE THAN 8.0 C/KM UP THROUGH 650 MB! IN ADDITION STRONG OMEGA (LIFT/RISING AIR IN THE ATMOSPHERE) IS FOUND WITH PLENTY OF MOISTURE RIGHT IN THE SNOW GROWTH REGION. THINK BIG FLAKES, HIGH EFFICIENCY OF ACCUMULATING SNOWS. WILL ADD CHANCE OF HEAVY SNOW FOR THE FRIDAY EVENING FORECAST. SNOWFALL AMOUNTS OF A FEW INCHES LIKELY BUT AGAIN IT WILL BE THE RATE OF FALL WHICH WILL CAUSE POOR VISIBILITIES AND DANGEROUS ROADS. SATURDAY/SATURDAY NIGHT...BRUTAL COLD. 850 TEMPS FALL TO BETWEEN -28C AND -30C! "OFFICIAL" HIGHS SATURDAY WILL BE IN THE TEENS AT MIDNIGHT FRIDAY NIGHT, WITH TEMPS FALLING INTO THE SINGLE DIGITS BY SATURDAY AFTERNOON. SOME AREAS WILL LIKELY DROP BELOW ZERO FOR TEMPS SATURDAY AFTERNOON, ESPECIALLY IN NY STATE! THIS ALONE IS COLD BUT A PRESSURE GRADIENT BETWEEN AN OCEAN STORM AND HIGH PRESSURE OVER THE MIDWEST WILL PRODUCE ENOUGH WIND FOR WIND CHILL READINGS BETWEEN -10 AND -30. WE WILL CONTINUE TO HIGHLIGHT THE HIGH CONFIDENCE FOR EXTREME COLD AND DANGEROUS WIND CHILLS IN OUR HWO, ON SOCIAL MEDIA, AND IN OUR ONLINE BRIEFING PACKAGE FOUND AT WEATHER.GOV/BGM UNDER WEATHER HAZARD BRIEFING AT THE BOTTOM OF THE PAGE. LOWS SATURDAY NIGHT WILL BE BELOW ZERO EVERYWHERE, WITH -20 READINGS POSSIBLE IN OUR COLDER SPOTS. IMPRESSIVE COLD AND THE ONLY SILVER LINING IS THE FACT IT WON`T LAST LONG. SEE BELOW FOR MORE ON MILDER WEATHER NEXT WEEK. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... 245 PM THU UPDATE... WE START OFF WELL SUBZERO DAWN SUNDAY. WINDS WILL BE SIGNIFICANTLY LESS THAN SATURDAY...YET STILL ENOUGH TO YIELD DANGEROUSLY LOW WIND CHILLS FOR AT LEAST THE FIRST HALF OF THE DAY BECAUSE IT WILL TAKE UNTIL LATE SUNDAY- SUNDAY NIGHT FOR HIGH PRESSURE TO ACTUALLY BUILD IN. LAKE MOISTURE STILL TRAPPED UNDER THE DEVELOPING SUBSIDENCE INVERSION WILL ALSO CONTINUE SCATTERED SNOW SHOWERS AND FLURRIES FROM STEUBEN COUNTY THROUGH THE FINGER LAKES TO SYRACUSE REGIONS...BUT WITH ONLY LIGHT DRY FLUFFY ACCUMULATIONS. HIGHS WILL ONLY BE IN THE SINGLE DIGITS TO AROUND 12 DEGREES. BUSY PATTERN COMES TOGETHER FOR MONDAY THROUGH WEDNESDAY. SHARP TROUGH FROM THIS WEEKEND LIFTS OUT...ONLY FOR MEAN UPPER TROUGH POSITIONING TO RETROGRADE SLIGHTLY WEST AS A NEW ONE DIGS INTO THE GREAT LAKES REGION. PHASING OF NORTHERN AND SOUTHERN STREAMS LOOKS LIKELY TO PRODUCE A LOW PRESSURE SYSTEM SOMEWHERE IN THE SOUTHEAST...WHICH THEN DEEPENS WHILE HEADING NORTHEAST. WITH RETROGRADED TROUGH...WARMER AIR WILL BE ABLE TO ADVECT IN AS THE SYSTEM APPROACHES. THE DEVIL IS IN THE DETAILS...AND WHILE THE MODELS AGREE ON EXISTENCE OF THE SYSTEM...THEY HAVE BEEN INCONSISTENT ON ITS TRACK AND AMOUNT OF WARM AIR RUN-TO-RUN AND MODEL-TO-MODEL. ONE THING THAT APPEARS MISSING IS HIGH PRESSURE IN THE NORTHEAST FOR ANCHORING THE COLD AIR...SO THE WARMER TREND IN LATEST GUIDANCE MAKES SENSE. ALL WE CAN SAY AT THIS POINT IS A FAIR AMOUNT OF PRECIPITATION IS LOOKING PROBABLE ESPECIALLY MONDAY NIGHT THROUGH TUESDAY NIGHT...BUT PRECIPITATION TYPE IS VERY QUESTIONABLE. STAY TUNED. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... LAKE EFFECT BANDS WITH IFR TO BELOW ALT MINS FOR VIS WILL CONTINUE TO IMPACT KSYR AND KRME THIS AFTERNOON...PERSISTING INTO EVENING FOR KSYR BEFORE LIFTING BACK BRIEFLY INTO KRME LATE TONIGHT BEFORE ENDING. BLSN WILL ALSO HAMPER VIS THIS AFTERNOON UNTIL THE WNW WINDS DIMINISH THIS EVENING...AND THEN BACK SOUTHWESTERLY FRIDAY MORNING /VRB TO SE KRME/. FURTHER SOUTH...THINNER BANDS WILL BRIEFLY VISIT THE OTHER NY TERMINALS...INCLUDING INTERMITTENT IFR VIS FOR KBGM THROUGH 20Z AND MVFR VIS FOR KITH. KAVP AND KELM WILL GET FLURRIES BUT LIKELY NON-RESTRICTING. EXCEPT FOR THE LINGERING KSYR-KRME ISSUES MENTIONED ABOVE...ALL TERMINALS GO VFR TONIGHT THROUGH FRIDAY MORNING. .OUTLOOK... FRI AFTN-NGT...VFR UNTIL STRONG ARCTIC FRONT BLASTS THROUGH WITH A PROBABLE LOW VIS SNOW SQUALL ROUGHLY 01Z SAT NW TO 07Z SAT SE. SAT...OCCASIONAL RESTRICTIONS FROM SCT -SHSN AND GUSTY WINDS/BLSN. SAT NGT-SUN...LAKE EFFECT SCT -SHSN AND ASSOCIATED BRIEF RESTRICTIONS KSYR AND PERHAPS KITH-KELM. MON-TUE...RESTRICTIONS IN POTENTIAL SNOW-TO-MIX AS AN EAST COAST SYSTEM MOVES THROUGH...BEST CHANCE MON NGT-TUE. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ016-017-044>046. LAKE EFFECT SNOW WARNING UNTIL 4 AM EST FRIDAY FOR NYZ009-018- 036-037. && $$ SYNOPSIS...HEDEN NEAR TERM...HEDEN/MSE SHORT TERM...HEDEN LONG TERM...MDP AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1253 PM EST THU FEB 11 2016 .SYNOPSIS... LAKE EFFECT SNOW WILL BE HEAVY AT TIMES THROUGH TONIGHT IN PARTS OF CENTRAL NEW YORK...GENERALLY SOUTHEAST OF LAKE ONTARIO. SCATTERED SNOW SHOWERS AND FLURRIES WILL OCCUR ELSEWHERE WITH LIGHT ACCUMULATIONS. A STRONG ARCTIC FRONT WILL DROP THROUGH THE REGION LATE FRIDAY...BRINGING THE COLDEST AIR MASS SINCE LAST WINTER. WIND CHILLS WILL BE DANGEROUSLY LOW...WELL BELOW ZERO...SATURDAY THROUGH SATURDAY NIGHT. A MODERATING TREND IS EXPECTED EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... UPDATED AT 1130 AM... MAIN LAKE EFFECT BANDS CONTINUE E-SE OF LAKE ONTARIO ON ABOUT A 290 FLOW LATE THIS MORNING WITH NUMEROUS SECONDARY WEAKER BANDS FARTHER SOUTH EXTENDING INTO NORTHERN PA. BANDS STILL APPEAR TO BE SHIFTING SLOWLY SOUTH AND ARE NEAR THE THRUWAY LATE THIS MORNING WITH STILL THE POTENTIAL FOR SOME HEAVY BANDS TO GET INTO THE CITIES OF SYRACUSE AND UTICA AT SOME POINT THIS AFTERNOON. STILL EXPECTING SEVERAL INCHES THIS AFTERNOON FROM NORTHERN ONONDAGA COUNTY EAST TO WEST CENTRAL ONEIDA COUNTY WITH LESS TO THE SOUTH. ATMOSPHERE UPSTREAM FROM THESE BANDS IS BECOMING INCREASINGLY DRY AND NO GOOD CONNECTION WITH LAKE HURON / GEORGIAN BAY CAN BE SEEN ON LATEST VISIBLE IMAGERY. ALSO DENDRITIC SNOW GROWTH POTENTIAL IS NOT OPTIMAL AS THE ATMOSPHERE HAS BECOME COLD ENOUGH SO THAT ONLY A SHALLOW LAYER ABOVE -20 C EXISTS BELOW 900 MB. WILL KEEP CURRENT WARNINGS AND ADVISORIES GOING THROUGH THIS AFTERNOON AS SNOW SHOWERS AND BLOWING SNOW WILL MAKE FOR HAZARDOUS TRAVEL... ALTHOUGH WARNING TYPE ACCUMULATIONS LOOK TO REMAIN JUST NORTH OF THE CITY OF SYRACUSE THROUGH TODAY... WITH JUST ANOTHER COUPLE OF INCHES IN THE ADVISORY AREAS TO THE SOUTH. TEMPERATURES ARE ONLY EXPECTED TO RISE A FEW DEGREES FROM CURRENT LEVELS WITH TEENS IN MOST AREAS TO NEAR 20 IN THE LOWER ELEVATIONS OF NORTHERN PA. PREVIOUS DISCUSSION IS BELOW. 315 AM UPDATE... WANTED TO SEND OUT AN "EARLY" UPDATE TO REFLECT ON THE CURRENT SITUATION REGARDING OUR LAKE EFFECT EVENT. WILL SEND OUT A SEPARATE AFD FOR THE SHORT TERM PERIOD TO GO OVER THE DANGEROUS COLD OVER THE WEEKEND. FIRST THINGS FIRST, THE LAKE EFFECT. SEE OUR WEBSITE FOR OUR LATEST SNOWFALL MAP THAT I JUST POSTED. WARNINGS AND ADVISORIES WILL REMAIN IN PLACE. I DID SHIFT THE HEAVIER AXIS OF SNOW FARTHER NORTH, TO REFLECT RADAR TRENDS FROM YESTERDAY EVENING THROUGH NOW. THE CHANGE WILL INCREASE AMOUNTS IN WEST CENTRAL ONEIDA COUNTY QUITE A BIT, WHILE DROPPING OFF SHARPLY TOWARD THE CITY OF UTICA. I KEPT NORTHERN ONONDAGA IN THE HIGHER AMOUNTS AS WELL, ALTHOUGH THEY WILL PROBABLY END UP BEING LOWER OVERALL THAN WEST CENTRAL ONEIDA. THE HIGHER TOTALS ACROSS NORTHERN ONONDAGA COUNTY IS A REFLECTION OF WHAT WE EXPECT TO COME, NOT UNDERSTANDING WE HAVEN`T SEE MUCH SNOW HERE YET. WHILE THE FORECAST GOING FORECAST IS LARGELY UNCHANGED FROM THIS POINT FORWARD, WE HAVEN`T SEE MUCH SNOW AT ALL FROM THE NEAR THE CITY OF SYRACUSE SOUTH. THUS I HAVE ADJUSTED TOTALS DOWN ACROSS SOUTHERN ONONDAGA/MADISON COUNTIES, ALONG WITH NORTHERN CORTLAND/CHENANGO/OTSEGO. WHILE THE BAND HAS BEEN MAINLY NORTH OF KSYR AND HAS EVEN WAVERED BACK INTO NORTHERN ONEIDA, CONFIDENCE IS HIGH THAT THE BAND WILL SINK SOUTH BETWEEN 09Z AND 12Z. THE LATEST HRRR AND RAP SOUNDINGS SHOW A MEAN WIND OF 275 NOW, ABRUPTLY SHIFTING TOWARD 290 BY 12Z, THEN LOCKING IN FOR THE REST OF THE DAY. KBUF RADAR SHOWS THE WESTERN SIDE OF THE BAND NEAR KROC IS ALREADY SHOWING SIGNS OF THIS CHANGE AND WILL FOLLOW. SO WHILE THE EVENT HAS PLAYED OUT WELL THUS FAR ACROSS WEST CENTRAL ONEIDA COUNTY, MANY IN METRO SYRACUSE AND ALONG THE THRUWAY MAY BE WONDERING WHAT LAKE SNOWS? DON`T LET YOUR GUARD DOWN YET AS HEAVIER SNOWS WILL SHIFT SOUTH TODAY. WITH INVERSION HEIGHTS GRADUALLY LOWERING TOWARD 5KFT BY LATE AFTERNOON, THE OVERALL INTENSITY WILL BE HIGHEST THIS MORNING, THEN A GRADUAL WEAKENING TREND INTO EARLY TONIGHT. SNOWFALL RATES THROUGH MID MORNING WILL STILL BE IN THE 1 TO 2"+ RANGE. THE FLOW REMAINS AROUND 290-300 THROUGH 06Z TONIGHT, BEFORE THE FLOW BACKS ENOUGH TOWARD THE SOUTHWEST TO LIFT THE BAND OUT OF OUR AREA TOWARD DAYBREAK FRIDAY. IN ALL A WIDESPREAD, LONG DURATION 6"+ LOOKS GOOD ACROSS MUCH OF CENTRAL NY, WITH CLOSER TO 1 1/2 FEET OVER WESTERN ONEIDA COUNTY. I CONTINUE TO MENTION BLOW AND DRIFTING SNOW WITHIN AND NEAR THE SNOW BANDS THEMSELVES. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... 4 AM UPDATE... OVERVIEW...SNOW SQUALLS LIKELY FRIDAY NIGHT ALONG AN ARCTIC FRONT THAT WILL DELIVER BRUTAL COLD SATURDAY AND SATURDAY NIGHT, WHICH WILL RIVAL WHAT WE SAW LAST FEBRUARY. FRIDAY/FRIDAY NIGHT....MOST OF FRIDAY WILL BE QUIET WITH A SOUTHWEST FLOW AHEAD OF AN ARCTIC FRONT. THIS FLOW WILL KEEP MOST OF THE AREA DRY THROUGH THE DAYLIGHT HOURS. FRIDAY EVENING THE ARCTIC FRONT WILL CROSS THE AREA BETWEEN 0Z AND 06Z SATURDAY. SNOW SQUALLS LOOK LIKELY, WITH THE POTENTIAL FOR POOR VISIBILITY AND SNOWFALL RATES OF MORE THAN AN INCH PER HOUR. MODEL SOUNDINGS SHOW STEEP LAPSE RATES OF MORE THAN 8.0 C/KM UP THROUGH 650 MB! IN ADDITION STRONG OMEGA (LIFT/RISING AIR IN THE ATMOSPHERE) IS FOUND WITH PLENTY OF MOISTURE RIGHT IN THE SNOW GROWTH REGION. THINK BIG FLAKES, HIGH EFFICIENCY OF ACCUMULATING SNOWS. WILL ADD CHANCE OF HEAVY SNOW FOR THE FRIDAY EVENING FORECAST. SNOWFALL AMOUNTS OF A FEW INCHES LIKELY BUT AGAIN IT WILL BE THE RATE OF FALL WHICH WILL CAUSE POOR VISIBILITIES AND DANGEROUS ROADS. SATURDAY/SATURDAY NIGHT...BRUTAL COLD. 850 TEMPS FALL TO BETWEEN -28C AND -30C! "OFFICIAL" HIGHS SATURDAY WILL BE IN THE TEENS AT MIDNIGHT FRIDAY NIGHT, WITH TEMPS FALLING INTO THE SINGLE DIGITS BY SATURDAY AFTERNOON. SOME AREAS WILL LIKELY DROP BELOW ZERO FOR TEMPS SATURDAY AFTERNOON, ESPECIALLY IN NY STATE! THIS ALONE IS COLD BUT A PRESSURE GRADIENT BETWEEN AN OCEAN STORM AND HIGH PRESSURE OVER THE MIDWEST WILL PRODUCE ENOUGH WIND FOR WIND CHILL READINGS BETWEEN -10 AND -30. WE WILL CONTINUE TO HIGHLIGHT THE HIGH CONFIDENCE FOR EXTREME COLD AND DANGEROUS WIND CHILLS IN OUR HWO, ON SOCIAL MEDIA, AND IN OUR ONLINE BRIEFING PACKAGE FOUND AT WEATHER.GOV/BGM UNDER WEATHER HAZARD BRIEFING AT THE BOTTOM OF THE PAGE. LOWS SATURDAY NIGHT WILL BE BELOW ZERO EVERYWHERE, WITH -20 READINGS POSSIBLE IN OUR COLDER SPOTS. IMPRESSIVE COLD AND THE ONLY SILVER LINING IS THE FACT IT WON`T LAST LONG. SEE BELOW FOR MORE ON MILDER WEATHER NEXT WEEK. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... 430 PM UPDATE... ONLY SOME MODERATION IN TEMPERATURES EXPECTED SUNDAY AS ARCTIC HIGH SLIDES EAST RIGHT OVER THE AREA BY LATE DAY. WINDS WILL BE SIGNIFICANTLY LESS...YET WE START THE DAY WITH SUBZERO TEMPERATURES SO VERY COLD ANYWAYS. STILL EXPECT SOME LAKE EFFECT, THOUGH THIS WILL TEND TO BE DIMINISHING THROUGH THE DAY HAS THE HIGH MOVES IN. HIGHS LOOK TO RANGE FROM THE SINGLE DIGITS THROUGH MUCH OF THE CATSKILLS NORTH TO THE TUG HILL WITH LOW TO MID TEENS ELSEWHERE. PATTERN WILL BE PROGRESSIVE ENOUGH FOR CORE OF ARCTIC AIR TO MOVE OUT EARLY NEXT WEEK WITH MORE SIGNIFICANT MODERATION BACK TO AT LEAST SEASONAL. MODELS INDICATE THE NEXT UPPER TROUGH MOVING INTO THE EAST WITH LOW PRESSURE DEVELOPMENT BUT THERE IS MODEL DISAGREEMENT ON TIMING, TRACK, AND INTENSITY. FOR NOW, INDICATE CHANCE OF SNOW IN GRIDS FOR MONDAY THROUGH WEDNESDAY BUT THERE IS A CHANCE LOW COULD TRACK FAR ENOUGH WEST TO BRING RAIN TO SOME AREAS AS EARLY AS TUESDAY. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... LAKE EFFECT BANDS WITH IFR TO BELOW ALT MINS FOR VIS WILL CONTINUE TO IMPACT KSYR AND KRME THIS AFTERNOON...PERSISTING INTO EVENING FOR KSYR BEFORE LIFTING BACK BRIEFLY INTO KRME LATE TONIGHT BEFORE ENDING. BLSN WILL ALSO HAMPER VIS THIS AFTERNOON UNTIL THE WNW WINDS DIMINISH THIS EVENING...AND THEN BACK SOUTHWESTERLY FRIDAY MORNING /VRB TO SE KRME/. FURTHER SOUTH...THINNER BANDS WILL BRIEFLY VISIT THE OTHER NY TERMINALS...INCLUDING INTERMITTENT IFR VIS FOR KBGM THROUGH 20Z AND MVFR VIS FOR KITH. KAVP AND KELM WILL GET FLURRIES BUT LIKELY NON-RESTRICTING. EXCEPT FOR THE LINGERING KSYR-KRME ISSUES MENTIONED ABOVE...ALL TERMINALS GO VFR TONIGHT THROUGH FRIDAY MORNING. .OUTLOOK... FRI AFTN-NGT...VFR UNTIL STRONG ARCTIC FRONT BLASTS THROUGH WITH A PROBABLE LOW VIS SNOW SQUALL ROUGHLY 01Z SAT NW TO 07Z SAT SE. SAT...OCCASIONAL RESTRICTIONS FROM SCT -SHSN AND GUSTY WINDS/BLSN. SAT NGT-SUN...LAKE EFFECT SCT -SHSN AND ASSOCIATED BRIEF RESTRICTIONS KSYR AND PERHAPS KITH-KELM. MON-TUE...RESTRICTIONS IN POTENTIAL SNOW AS AN EAST COAST SYSTEM MOVES THROUGH...BEST CHANCE MON NGT-TUE. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ016-017-044>046. LAKE EFFECT SNOW WARNING UNTIL 4 AM EST FRIDAY FOR NYZ009-018- 036-037. && $$ SYNOPSIS...HEDEN NEAR TERM...HEDEN/MSE SHORT TERM...HEDEN LONG TERM...MDP AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1152 AM EST THU FEB 11 2016 .SYNOPSIS... LAKE EFFECT SNOW WILL BE HEAVY AT TIMES THROUGH TONIGHT IN PARTS OF CENTRAL NEW YORK...GENERALLY SOUTHEAST OF LAKE ONTARIO. SCATTERED SNOW SHOWERS AND FLURRIES WILL OCCUR ELSEWHERE WITH LIGHT ACCUMULATIONS. A STRONG ARCTIC FRONT WILL DROP THROUGH THE REGION LATE FRIDAY...BRINGING THE COLDEST AIR MASS SINCE LAST WINTER. WIND CHILLS WILL BE DANGEROUSLY LOW...WELL BELOW ZERO...SATURDAY THROUGH SATURDAY NIGHT. A MODERATING TREND IS EXPECTED EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... UPDATED AT 1130 AM... MAIN LAKE EFFECT BANDS CONTINUE E-SE OF LAKE ONTARIO ON ABOUT A 290 FLOW LATE THIS MORNING WITH NUMEROUS SECONDARY WEAKER BANDS FARTHER SOUTH EXTENDING INTO NORTHERN PA. BANDS STILL APPEAR TO BE SHIFTING SLOWLY SOUTH AND ARE NEAR THE THRUWAY LATE THIS MORNING WITH STILL THE POTENTIAL FOR SOME HEAVY BANDS TO GET INTO THE CITIES OF SYRACUSE AND UTICA AT SOME POINT THIS AFTERNOON. STILL EXPECTING SEVERAL INCHES THIS AFTERNOON FROM NORTHERN ONONDAGA COUNTY EAST TO WEST CENTRAL ONEIDA COUNTY WITH LESS TO THE SOUTH. ATMOSPHERE UPSTREAM FROM THESE BANDS IS BECOMING INCREASINGLY DRY AND NO GOOD CONNECTION WITH LAKE HURON / GEORGIAN BAY CAN BE SEEN ON LATEST VISIBLE IMAGERY. ALSO DENDRITIC SNOW GROWTH POTENTIAL IS NOT OPTIMAL AS THE ATMOSPHERE HAS BECOME COLD ENOUGH SO THAT ONLY A SHALLOW LAYER ABOVE -20 C EXISTS BELOW 900 MB. WILL KEEP CURRENT WARNINGS AND ADVISORIES GOING THROUGH THIS AFTERNOON AS SNOW SHOWERS AND BLOWING SNOW WILL MAKE FOR HAZARDOUS TRAVEL... ALTHOUGH WARNING TYPE ACCUMULATIONS LOOK TO REMAIN JUST NORTH OF THE CITY OF SYRACUSE THROUGH TODAY... WITH JUST ANOTHER COUPLE OF INCHES IN THE ADVISORY AREAS TO THE SOUTH. TEMPERATURES ARE ONLY EXPECTED TO RISE A FEW DEGREES FROM CURRENT LEVELS WITH TEENS IN MOST AREAS TO NEAR 20 IN THE LOWER ELEVATIONS OF NORTHERN PA. PREVIOUS DISCUSSION IS BELOW. 315 AM UPDATE... WANTED TO SEND OUT AN "EARLY" UPDATE TO REFLECT ON THE CURRENT SITUATION REGARDING OUR LAKE EFFECT EVENT. WILL SEND OUT A SEPARATE AFD FOR THE SHORT TERM PERIOD TO GO OVER THE DANGEROUS COLD OVER THE WEEKEND. FIRST THINGS FIRST, THE LAKE EFFECT. SEE OUR WEBSITE FOR OUR LATEST SNOWFALL MAP THAT I JUST POSTED. WARNINGS AND ADVISORIES WILL REMAIN IN PLACE. I DID SHIFT THE HEAVIER AXIS OF SNOW FARTHER NORTH, TO REFLECT RADAR TRENDS FROM YESTERDAY EVENING THROUGH NOW. THE CHANGE WILL INCREASE AMOUNTS IN WEST CENTRAL ONEIDA COUNTY QUITE A BIT, WHILE DROPPING OFF SHARPLY TOWARD THE CITY OF UTICA. I KEPT NORTHERN ONONDAGA IN THE HIGHER AMOUNTS AS WELL, ALTHOUGH THEY WILL PROBABLY END UP BEING LOWER OVERALL THAN WEST CENTRAL ONEIDA. THE HIGHER TOTALS ACROSS NORTHERN ONONDAGA COUNTY IS A REFLECTION OF WHAT WE EXPECT TO COME, NOT UNDERSTANDING WE HAVEN`T SEE MUCH SNOW HERE YET. WHILE THE FORECAST GOING FORECAST IS LARGELY UNCHANGED FROM THIS POINT FORWARD, WE HAVEN`T SEE MUCH SNOW AT ALL FROM THE NEAR THE CITY OF SYRACUSE SOUTH. THUS I HAVE ADJUSTED TOTALS DOWN ACROSS SOUTHERN ONONDAGA/MADISON COUNTIES, ALONG WITH NORTHERN CORTLAND/CHENANGO/OTSEGO. WHILE THE BAND HAS BEEN MAINLY NORTH OF KSYR AND HAS EVEN WAVERED BACK INTO NORTHERN ONEIDA, CONFIDENCE IS HIGH THAT THE BAND WILL SINK SOUTH BETWEEN 09Z AND 12Z. THE LATEST HRRR AND RAP SOUNDINGS SHOW A MEAN WIND OF 275 NOW, ABRUPTLY SHIFTING TOWARD 290 BY 12Z, THEN LOCKING IN FOR THE REST OF THE DAY. KBUF RADAR SHOWS THE WESTERN SIDE OF THE BAND NEAR KROC IS ALREADY SHOWING SIGNS OF THIS CHANGE AND WILL FOLLOW. SO WHILE THE EVENT HAS PLAYED OUT WELL THUS FAR ACROSS WEST CENTRAL ONEIDA COUNTY, MANY IN METRO SYRACUSE AND ALONG THE THRUWAY MAY BE WONDERING WHAT LAKE SNOWS? DON`T LET YOUR GUARD DOWN YET AS HEAVIER SNOWS WILL SHIFT SOUTH TODAY. WITH INVERSION HEIGHTS GRADUALLY LOWERING TOWARD 5KFT BY LATE AFTERNOON, THE OVERALL INTENSITY WILL BE HIGHEST THIS MORNING, THEN A GRADUAL WEAKENING TREND INTO EARLY TONIGHT. SNOWFALL RATES THROUGH MID MORNING WILL STILL BE IN THE 1 TO 2"+ RANGE. THE FLOW REMAINS AROUND 290-300 THROUGH 06Z TONIGHT, BEFORE THE FLOW BACKS ENOUGH TOWARD THE SOUTHWEST TO LIFT THE BAND OUT OF OUR AREA TOWARD DAYBREAK FRIDAY. IN ALL A WIDESPREAD, LONG DURATION 6"+ LOOKS GOOD ACROSS MUCH OF CENTRAL NY, WITH CLOSER TO 1 1/2 FEET OVER WESTERN ONEIDA COUNTY. I CONTINUE TO MENTION BLOW AND DRIFTING SNOW WITHIN AND NEAR THE SNOW BANDS THEMSELVES. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... 4 AM UPDATE... OVERVIEW...SNOW SQUALLS LIKELY FRIDAY NIGHT ALONG AN ARCTIC FRONT THAT WILL DELIVER BRUTAL COLD SATURDAY AND SATURDAY NIGHT, WHICH WILL RIVAL WHAT WE SAW LAST FEBRUARY. FRIDAY/FRIDAY NIGHT....MOST OF FRIDAY WILL BE QUIET WITH A SOUTHWEST FLOW AHEAD OF AN ARCTIC FRONT. THIS FLOW WILL KEEP MOST OF THE AREA DRY THROUGH THE DAYLIGHT HOURS. FRIDAY EVENING THE ARCTIC FRONT WILL CROSS THE AREA BETWEEN 0Z AND 06Z SATURDAY. SNOW SQUALLS LOOK LIKELY, WITH THE POTENTIAL FOR POOR VISIBILITY AND SNOWFALL RATES OF MORE THAN AN INCH PER HOUR. MODEL SOUNDINGS SHOW STEEP LAPSE RATES OF MORE THAN 8.0 C/KM UP THROUGH 650 MB! IN ADDITION STRONG OMEGA (LIFT/RISING AIR IN THE ATMOSPHERE) IS FOUND WITH PLENTY OF MOISTURE RIGHT IN THE SNOW GROWTH REGION. THINK BIG FLAKES, HIGH EFFICIENCY OF ACCUMULATING SNOWS. WILL ADD CHANCE OF HEAVY SNOW FOR THE FRIDAY EVENING FORECAST. SNOWFALL AMOUNTS OF A FEW INCHES LIKELY BUT AGAIN IT WILL BE THE RATE OF FALL WHICH WILL CAUSE POOR VISIBILITIES AND DANGEROUS ROADS. SATURDAY/SATURDAY NIGHT...BRUTAL COLD. 850 TEMPS FALL TO BETWEEN -28C AND -30C! "OFFICIAL" HIGHS SATURDAY WILL BE IN THE TEENS AT MIDNIGHT FRIDAY NIGHT, WITH TEMPS FALLING INTO THE SINGLE DIGITS BY SATURDAY AFTERNOON. SOME AREAS WILL LIKELY DROP BELOW ZERO FOR TEMPS SATURDAY AFTERNOON, ESPECIALLY IN NY STATE! THIS ALONE IS COLD BUT A PRESSURE GRADIENT BETWEEN AN OCEAN STORM AND HIGH PRESSURE OVER THE MIDWEST WILL PRODUCE ENOUGH WIND FOR WIND CHILL READINGS BETWEEN -10 AND -30. WE WILL CONTINUE TO HIGHLIGHT THE HIGH CONFIDENCE FOR EXTREME COLD AND DANGEROUS WIND CHILLS IN OUR HWO, ON SOCIAL MEDIA, AND IN OUR ONLINE BRIEFING PACKAGE FOUND AT WEATHER.GOV/BGM UNDER WEATHER HAZARD BRIEFING AT THE BOTTOM OF THE PAGE. LOWS SATURDAY NIGHT WILL BE BELOW ZERO EVERYWHERE, WITH -20 READINGS POSSIBLE IN OUR COLDER SPOTS. IMPRESSIVE COLD AND THE ONLY SILVER LINING IS THE FACT IT WON`T LAST LONG. SEE BELOW FOR MORE ON MILDER WEATHER NEXT WEEK. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... 430 PM UPDATE... ONLY SOME MODERATION IN TEMPERATURES EXPECTED SUNDAY AS ARCTIC HIGH SLIDES EAST RIGHT OVER THE AREA BY LATE DAY. WINDS WILL BE SIGNIFICANTLY LESS...YET WE START THE DAY WITH SUBZERO TEMPERATURES SO VERY COLD ANYWAYS. STILL EXPECT SOME LAKE EFFECT, THOUGH THIS WILL TEND TO BE DIMINISHING THROUGH THE DAY HAS THE HIGH MOVES IN. HIGHS LOOK TO RANGE FROM THE SINGLE DIGITS THROUGH MUCH OF THE CATSKILLS NORTH TO THE TUG HILL WITH LOW TO MID TEENS ELSEWHERE. PATTERN WILL BE PROGRESSIVE ENOUGH FOR CORE OF ARCTIC AIR TO MOVE OUT EARLY NEXT WEEK WITH MORE SIGNIFICANT MODERATION BACK TO AT LEAST SEASONAL. MODELS INDICATE THE NEXT UPPER TROUGH MOVING INTO THE EAST WITH LOW PRESSURE DEVELOPMENT BUT THERE IS MODEL DISAGREEMENT ON TIMING, TRACK, AND INTENSITY. FOR NOW, INDICATE CHANCE OF SNOW IN GRIDS FOR MONDAY THROUGH WEDNESDAY BUT THERE IS A CHANCE LOW COULD TRACK FAR ENOUGH WEST TO BRING RAIN TO SOME AREAS AS EARLY AS TUESDAY. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... LE SNOW BAND IS XPCTD TO DROP SWRD ACROSS RME AND STALL IN THE SYR AREA FOR SVRL HRS TODAY. THIS WEILL BRING BRIEF IFR CONDS TO RME...AND PROLONGED IFR CIGS AND VSBY TO SYR FOR MUCH OF THE DAY. ELSEWHERE...SCT SNOW SHWRS WILL BRING BRIEF LWR CONDS BUT MUCH OF THE DAY WILL BE VFR ELSEWHERE. BAND IS XPCTD TO LIFT NWRD LTR THIS EVE LVG VFR CONDS AT ALL STATIONS. .OUTLOOK... FRI THRU SUN...VARIABLE CEILING AND VSBY RESTRICTIONS DUE TO PERIODS OF WIDESPREAD LIGHT SNOW AND BANDS OF MORE INTENSE LAKE EFFECT SNOW...ESPECIALLY NORTHERN HALF. LESS COVERAGE AND TIME AFFECTED FOR THE SOUTHERN AREAS. MON...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ016-017-044>046. LAKE EFFECT SNOW WARNING UNTIL 4 AM EST FRIDAY FOR NYZ009-018- 036-037. && $$ SYNOPSIS...HEDEN NEAR TERM...HEDEN/MSE SHORT TERM...HEDEN LONG TERM...MDP AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1101 AM EST THU FEB 11 2016 .SYNOPSIS... COLD WEST-NORTHWESTERLY FLOW WILL REMAIN IN PLACE ACROSS THE LOWER GREAT LAKES WITH AREAS OF LAKE EFFECT SNOW TODAY. TONIGHT AND FRIDAY...AHEAD OF THE ARCTIC FRONT SOUTHWESTERLY FLOW WILL DEVELOP SHIFTING LAKE EFFECT SNOWS BACK NORTHWARD ACROSS BUFFALO AND WATERTOWN AREAS. BEHIND THE ARCTIC FRONT EXPECT DANGEROUSLY COLD TEMPERATURES AND WIND CHILLS THROUGH SATURDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... A WEST-NORTHWESTERLY FLOW OF COLD AIR WILL CONTINUE LAKE EFFECT SNOWS EAST-SOUTHEAST OF THE LAKES TODAY IN A MULTIBANDED ORIENTATION DUE TO SHORTER FETCH ACROSS THE LAKES. HIGH PRESSURE OVER THE OHIO VALLEY WILL EXPAND NORTH AND EAST THROUGH THIS AFTERNOON AND SHOULD WEAKEN THE LAKE SNOWS SOME FROM WHAT WE SAW LAST NIGHT AS THE CAPPING INVERSION LOWERS TO AROUND 8KFT. KBUF RADAR SHOWS A NARROW BAND OF SNOW WITH A GEORGIAN BAY CONNECTION EXTENDING FROM NIAGARA COUNTY SOUTHEAST TO NORTHERN ERIE...GENESEE AND LIVINGSTON COUNTIES. THIS SHOULD CONTINUE TO SETTLE SOUTH THROUGH THIS MORNING WHICH WOULD BRING IT ACROSS METRO BUFFALO AND INTO WYOMING COUNTIES. THIS BAND COULD BRING A BRIEF PERIOD OF INTENSE SNOWS WITH REDUCED VISIBILITY AND A QUICK FRESH COATING OF MAYBE AN INCH OF SNOW AS IT SHIFTS SOUTH. ACROSS THE SOUTHERN LAKE ONTARIO SHORELINE MULTIPLE NARROW BANDS OF LAKE EFFECT SNOW WILL CONTINUE TO IMPACT THE SOUTHERN SHORELINE COUNTIES WHERE WARNINGS WILL REMAIN UP. AN ADDITIONAL INCH OR TWO OF SNOW IS POSSIBLE FROM NIAGARA EAST TO MONROE COUNTIES FROM THESE LAKE SNOWS. FURTHER SOUTH...LAKE SNOWS HAVE LARGELY SETTLED SOUTH TOWARD ERIE PA WITH JUST SOME SCATTERED SNOW SHOWERS ACROSS THE SOUTHERN TIER. THE LATEST HRRR MODEL INDICATES THE NARROW BAND OF SNOW NEAR ERIE WILL SHIFT BACK NORTH ACROSS CHAUTAUQUA AND CATTARAUGUS COUNTIES THIS AFTERNOON WITH A POTENTIAL FOR 2-3 ADDITIONAL INCHES OF SNOW WHICH IS WHY THE LAKE EFFECT SNOW WARNINGS WILL REMAIN IN EFFECT DESPITE THIS THE CURRENT LULL IN ACTIVITY. KTYX RADAR CONTINUES TO SHOW SEVERAL NARROW BANDS OF LAKE EFFECT SNOW IMPACTING NORTHEAST WAYNE...NORTHERN CAYUGA AND OSWEGO COUNTY WHICH MAY BRING AN ADDITIONAL 1-3 INCHES THROUGH TODAY. THERE ARE ALSO SOME LIGHT SNOW SHOWERS FURTHER NORTH DRIFTING ACROSS JEFFERSON AND LEWIS COUNTIES WHICH SHOULD ONLY BRING UP TO AN ADDITIONAL INCH THROUGH TODAY. OUTSIDE OF THE MAIN LAKE EFFECT SNOW AREAS...THE REMAINDER OF THE REGION WILL JUST EXPERIENCE MUCH LIGHTER AND MUCH MORE SCATTERED TRANSIENT LAKE AND OROGRAPHICALLY-DRIVEN LIGHT SNOW SHOWERS...WITH ONLY MINOR ADDITIONAL ACCUMULATIONS EXPECTED. OTHERWISE IT WILL BE COLD AND ON THE BRISK SIDE AGAIN...WITH DAYTIME HIGHS ONLY RANGING FROM AROUND 10 ABOVE ACROSS THE HIGHEST TERRAIN TO THE MID TEENS ELSEWHERE. TONIGHT...A CONTINUED WEST-NORTHWESTERLY FLOW WILL CONTINUE TO MAINTAIN WEAKER LAKE SNOWS SOUTHEAST OF THE LAKES FOR A GOOD PORTION OF THIS EVENING...WITH THIS ACTIVITY BEING HELD MORE IN CHECK BY THE AFOREMENTIONED LOWERING CAPPING INVERSION... WHICH WILL RUN BETWEEN 3 AND 5 KFT OFF LAKE ERIE...AND WILL DROP TO BETWEEN 4 AND 5 KFT OFF LAKE ONTARIO. AFTER THAT TIME...GRADUAL BACKING OF THE LOW LEVEL FLOW TO WESTERLY AND THEN WEST-SOUTHWESTERLY IN ADVANCE OF AN APPROACHING ARCTIC FRONT WILL RESULT IN THE LAKE BANDS SLOWLY MIGRATING NORTHWARD THROUGH THE BALANCE OF THE NIGHT... WITH THE LAKE ERIE ACTIVITY REACHING THE BUFFALO SOUTHTOWNS...AND THE LAKE ONTARIO LAKE SNOWS REACHING THE TUG HILL REGION BY DAYBREAK. WHILE A CONTINUED LOWER CAP AND INCREASING AMOUNTS OF DIRECTIONAL SHEAR BELOW IT SHOULD KEEP THE MIGRATING LAKE SNOWS FROM BECOMING TERRIBLY ORGANIZED...THE GRADUALLY INCREASING FETCH ACROSS BOTH LAKES SHOULD ALLOW FOR AT LEAST SOME INCREASE IN STRENGTH LATE...ENOUGH FOR THE BANDS TO PRODUCE AN ADDITIONAL INCH OR TWO OF ACCUMULATION DURING THEIR NORTHWARD MIGRATION. AT THIS POINT IT APPEARS THAT THE MORE SIGNIFICANT ACCUMULATIONS FROM THESE WILL HOLD OFF UNTIL DURING THE DAY ON FRIDAY...WHEN DEEPENING MOISTURE AND A RISING CAP OUT IN ADVANCE OF THE APPROACHING ARCTIC BOUNDARY SHOULD ALLOW FOR A NOTEWORTHY UPTICK IN BAND ORGANIZATION...MORE ON WHICH IS DISCUSSED IN THE SHORT TERM SECTION BELOW. OUTSIDE OF THE LAKE SNOWS...EXPECT A QUIET AND LARGELY DRY NIGHT TONIGHT...WITH LOWS RANGING FROM AROUND ZERO ACROSS THE NORTH COUNTRY TO THE 5 TO 10 ABOVE RANGE ELSEWHERE. GIVEN A DEVELOPING WARM AIR ADVECTION REGIME...THESE WILL LIKELY OCCUR AROUND MIDNIGHT...BEFORE GIVING WAY TO SLOWLY RISING TEMPERATURES OVERNIGHT. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... LAKE SNOWS WILL REORGANIZE AND INTENSIFY FRIDAY AS THE FLOW BACKS TO SOUTHWEST IN RESPONSE TO A WEAK LOW DROPPING SOUTH FROM CANADA AND AHEAD OF THE ADVANCING ARCTIC BOUNDARY. OFF LAKE ERIE...FORECAST SOUNDINGS CONTINUE TO SHOW A FAIRLY WELL ALIGNED SOUTHWEST FLOW LOW LEVEL FLOW DEVELOPING EARLY FRIDAY. INITIALLY MOISTURE WILL BE LIMITED...BUT WITH THE APPROACH OF THE LOW AND LONG FETCH DOWN THE LAKE...EXPECT A FAIRLY CONSOLIDATED AND INTENSE LAKE EFFECT BAND TO DEVELOP. CONSENSUS HIGH RESOLUTION GUIDANCE CONTINUES TO REFLECT THESE TRENDS. THE RGEM ALONG WITH THE NAM/GFS ALL SUGGEST A STRONG CONVERGENCE SHOULD CONTINUE TO LIFT NORTHWARD INTO BUFFALO METRO AREA DURING THE DAY FRIDAY. FAVORABLE LAKE PARAMETERS WILL EXIST WITH PLENTY OF OVER-LAKE INSTABILITY AS INVERSION HEIGHTS APPROACH 10K FEET WITHIN A WELL ALIGNED SOUTHWEST FLOW...WITH THE BAND POSSIBLY EXTENDING INLAND ACROSS WYOMING AND GENESEE COUNTIES...AND EVEN PERHAPS AS FAR NORTH AS NIAGARA AND ORLEANS COUNTIES IF THE FLOW CAN BACK ENOUGH. FOR NOW WILL MAINTAIN THE LAKE EFFECT SNOW DUE TO UNCERTAINTIES IN THE EXACT PLACEMENT OF THE HEAVIEST BAND. OFF LAKE ONTARIO...A WELL ALIGNED SOUTHWESTERLY FLOW IS FORECAST TO DEVELOP FRIDAY SIMILAR TO LAKE ERIE. THIS WILL NOT ONLY TAP INTO MOISTURE FROM AN APPROACHING SHORTWAVE...BUT ALSO MOISTURE FROM WHATEVER FORMS OFF LAKE ERIE. THIS WILL BRING THE POTENTIAL FOR SIGNIFICANT SNOWS ON FRIDAY INTO FRIDAY NIGHT FOR WATERTOWN AND VICINITY...WITH THE BAND POSSIBLY EXTENDING INLAND ACROSS NORTHERN LEWIS COUNTY. 850 MB TEMPERATURES AROUND -16C AND INVERSION HEIGHTS FORECAST TO RISE TO NEARLY 15K FT AND A FAVORABLY DENDRITIC SNOW GROWTH ZONE SHOULD PROVIDE FAVORABLE PARAMETERS FOR SIGNIFICANT SNOWS. WILL MAINTAIN THE LAKE EFFECT SNOW WATCH FOR JEFFERSON COUNTY AND ADD LEWIS COUNTY WITH THE POTENTIAL FOR SIGNIFICANT LAKE SNOWS REACHING THE NORTHERN PART OF THE COUNTY. ON FRIDAY EVENING...A POWERFUL ARCTIC FRONT WILL SURGE SOUTH ACROSS THE REGION. THIS ARCTIC FRONT WILL LIKELY CAPTURE AND MERGE WITH THE LAKE EFFECT SNOW BAND OFF LAKE ONTARIO...WITH A VERY HEAVY SNOW SQUALL PASSING SOUTH ACROSS THE EASTERN LAKE ONTARIO REGION. THIS WILL LIKELY PRODUCE AN INCH OR TWO OF SNOW IN MANY AREAS...WITH LOCALLY HIGHER AMOUNTS SOUTHEAST OF THE LAKES WHERE THE LAKE CONTRIBUTION MAXIMIZES. BEHIND THE ARCTIC FRONT...MULTIPLE STREAMERS OF LAKE EFFECT SNOW SHOWERS WILL DEVELOP SOUTH OF THE LAKES LATE FRIDAY NIGHT AS FLOW BECOMES NORTHWEST AND EVENTUALLY NORTH NORTHWEST. THE FRONT WILL ALSO USHER IN BITTERLY COLD TEMPERATURES WHICH WILL BE BELOW ZERO IN MOST AREAS BY DAYBREAK SATURDAY. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... A FRIGID ARCTIC AIRMASS WILL TAKE HOLD OF THE EASTERN GREAT LAKES AND NEW ENGLAND THIS WEEKEND. A CONSENSUS OF 12Z GUIDANCE DROPS 850MB TEMPERATURES TO AROUND -30C AT BUFFALO DURING THE DAY AT BUFFALO...WITH -33C ACROSS THE EASTERN LAKE ONTARIO REGION. THE COLDEST TEMPERATURE EVER RECORDED AT 850MB ON A KBUF SOUNDING IN THE MONTH OF FEBRUARY IS -28C...AND THE COLDEST EVER RECORDED FOR ANY MONTH IS -32C. THIS WILL RESULT IN BITTERLY COLD TEMPERATURES DURING THE DAY SATURDAY WITH DAYTIME TEMPERATURES STRUGGLING TO RISE ABOVE ZERO. DAYTIME HIGHS WILL ALMOST CERTAINLY BE BELOW ZERO IN THE EASTERN LAKE ONTARIO REGION. PERSISTENT WINDS OF 10 TO 15 MPH ON SATURDAY NIGHT WILL LIMIT RADIATIONAL COOLING...BUT EVEN SO IT WILL BE VERY COLD WITH BELOW ZERO LOWS REGION-WIDE. LOWS OF -20F OR COLDER ARE POSSIBLE ACROSS THE NORTH COUNTRY WITH NO MODERATING LAKE INFLUENCE. THE COMBINATION OF MODERATE WINDS AND FRIGID TEMPERATURES WILL PRODUCE DANGEROUSLY COLD WIND CHILLS LATE FRIDAY NIGHT THROUGH EARLY SUNDAY MORNING. ISSUING A WIND CHILL WATCH FOR THE ENTIRE CWA...AREAS NEAR THE LAKESHORES MAY ONLY REACH ADVISORY CRITERIA HOWEVER NEED TO HIGHLIGHT THIS DANGEROUSLY COLD WEATHER. THE FRIGID NORTH FLOW OVER THE LAKES WILL PRODUCE WIDESPREAD LAKE EFFECT SNOW SHOWERS ACROSS WESTERN AND CENTRAL NY. DESPITE THE EXTREME INSTABILITY...AIRMASSES THIS COLD ARE ALSO VERY DRY AND TEMPERATURES BECOME TOO COLD FOR DENDRITES. THIS WILL FORCE SNOWFLAKES TO BE VERY SMALL AND LIMIT ACCUMULATIONS...ALTHOUGH SEVERAL INCHES ARE LIKELY SOUTH OF BOTH LAKES. THE LAKE EFFECT SNOW WILL DIMINISH IN COVERAGE AND INTENSITY SUNDAY. 12Z GUIDANCE IS A BIT FASTER MOVING THE SURFACE RIDGE ACROSS THE REGION...WITH LAKE EFFECT SNOW LIKELY TO TAPER OFF BY SUNDAY NIGHT. AFTER THIS THERE IS GENERAL MODEL AGREEMENT THAT TEMPERATURES WILL WARM BACK TO NEAR NORMAL EARLY NEXT WEEK. HOWEVER...THE 12Z ECMWF IS SIGNIFICANTLY DIFFERENT FROM THE GFS/GGEM. THE ECMWF HAS CONSISTENTLY DEVELOPED A STRONG WAVE OF LOW PRESSURE WITH SIGNIFICANT QPF ACROSS OUR REGION WHICH WOULD FALL AS RAIN OR SNOW. THE GGEM/GFS HAVE THIS SYSTEM BUT KEEP IT WELL TO OUR EAST...AND INSTEAD ARE A BIT COLDER WITH A CHANCE FOR LIGHT SNOW SHOWERS. THE FORECAST WILL REFLECT A CONSENSUS BETWEEN THIS GUIDANCE...WITH NEAR NORMAL TEMPERATURES AND CHANCE POPS. && .AVIATION /16Z THURSDAY THROUGH MONDAY/... LAKE EFFECT SNOWS AND ATTENDANT IFR/LIFR WILL BE FOUND EAST- SOUTHEAST OF THE LAKES TODAY AND INTO THIS EVENING...WITH MVFR/VFR CONDITIONS AND MUCH MORE SCATTERED SNOW SHOWERS PREVAILING ELSEWHERE. EXPECT THE MOST SIGNIFICANT LAKE SNOWS OF THE DAY TO COME THIS MORNING...WITH THE ACTIVITY THEN GRADUALLY WEAKENING FROM WEST TO EAST THIS AFTERNOON AND EVENING IN CONJUNCTION WITH DIMINISHING UPSTREAM CONNECTIONS...THE INTRUSION OF DRIER AIR ALOFT...AND A LOWERING CAPPING INVERSION. FROM THE LATE EVENING HOURS ON THROUGH THE REMAINDER OF TONIGHT... GRADUAL BACKING OF THE LOW LEVEL FLOW TO WESTERLY AND THEN WEST- SOUTHWESTERLY IN ADVANCE OF AN APPROACHING ARCTIC FRONT WILL RESULT IN WEAKER LAKE SNOWS SLOWLY MIGRATING NORTHWARD...WITH THE LAKE ERIE ACTIVITY REACHING THE BUFFALO SOUTHTOWNS...AND THE LAKE ONTARIO LAKE SNOWS REACHING THE TUG HILL REGION BY 12Z FRIDAY. EXPECT IFR/MVFR TO PREVAIL WITHIN THE MIGRATING LAKE SNOWS...WITH GENERAL VFR CONDITIONS THE RULE ELSEWHERE. OUTLOOK... FRIDAY...IFR/MVFR WITH SNOW SHOWERS LIKELY...AND AREAS OF HEAVIER LAKE EFFECT SNOW EAST/NORTHEAST OF THE LAKES. SATURDAY...IFR/MVFR IN LAKE EFFECT SNOW SHOWERS SOUTH OF THE LAKES... WITH MVFR/VFR ACROSS THE NORTH COUNTRY. SUNDAY...A CHANCE OF IFR/MVFR IN WEAKENING LAKE EFFECT SNOW SHOWERS SOUTH OF THE LAKES...OTHERWISE MVFR/VFR. MONDAY...MAINLY VFR WITH A CHANCE OF SNOW SHOWERS. && .MARINE... A BRISK FLOW OF PROGRESSIVELY COLDER ARCTIC AIR WILL CONTINUE TO OVERSPREAD THE REGION THROUGH THE WEEKEND...RESULTING IN A PROLONGED PERIOD OF ADVISORY-WORTHY WINDS AND WAVES ACROSS THE LOWER LAKES. IN ADDITION TO THE ABOVE...THE PASSAGE OF AN ARCTIC COLD FRONT LATER FRIDAY AFTERNOON AND FRIDAY EVENING WILL ALSO USHER IN A TRULY FRIGID AIRMASS FOR LATER FRIDAY NIGHT AND THE UPCOMING WEEKEND...WHICH IN CONJUNCTION WITH THE AFOREMENTIONED WINDS WILL RESULT IN A GREATLY HEIGHTENED POTENTIAL FOR HEAVY FREEZING SPRAY. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH LATE FRIDAY NIGHT FOR NYZ007-008. WIND CHILL WATCH FROM LATE FRIDAY NIGHT THROUGH SUNDAY MORNING FOR NYZ001>008-010>014-019>021-085. LAKE EFFECT SNOW WARNING UNTIL 4 AM EST FRIDAY FOR NYZ004>006. LAKE EFFECT SNOW WARNING UNTIL 4 PM EST THIS AFTERNOON FOR NYZ001>003-019-020. LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH FRIDAY EVENING FOR NYZ012-019-020-085. LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH FRIDAY EVENING FOR NYZ010-011. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ020. SMALL CRAFT ADVISORY UNTIL 7 PM EST SATURDAY FOR LEZ040- 041. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LOZ030. SMALL CRAFT ADVISORY UNTIL 7 PM EST SATURDAY FOR LOZ042>045. && $$ SYNOPSIS...AR/JJR NEAR TERM...JJR/SMITH SHORT TERM...LEVAN/TMA LONG TERM...APFFEL/LEVAN AVIATION...JJR/SMITH MARINE...JJR/SMITH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1029 AM EST THU FEB 11 2016 .SYNOPSIS... A GENERAL WEST-NORTHWESTERLY FLOW OF COLD AIR WILL CONTINUE ACROSS THE LOWER GREAT LAKES TODAY AND INTO THIS EVENING...WHICH WILL MAINTAIN AREAS OF LAKE EFFECT SNOW SOUTHEAST OF THE LAKES. WINDS WILL THEN TURN MORE SOUTHWESTERLY LATER TONIGHT AND FRIDAY OUT IN ADVANCE OF AN APPROACHING ARCTIC COLD FRONT...RESULTING IN THE LAKE SNOWS LIFTING NORTHWARD TO THE BUFFALO AND WATERTOWN AREAS. THE ARCTIC FRONT ITSELF WILL THEN CROSS THE REGION LATE FRIDAY AFTERNOON AND FRIDAY EVENING WHILE BRINGING A BURST OF SNOW TO MOST AREAS... WITH DOWNRIGHT FRIGID CONDITIONS AND DANGEROUSLY COLD WIND CHILLS THEN FOLLOWING IN ITS WAKE FOR FRIDAY NIGHT THROUGH SATURDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... A WEST-NORTHWESTERLY FLOW OF COLD AIR WILL CONTINUE LAKE EFFECT SNOWS EAST-SOUTHEAST OF THE LAKES TODAY IN A MULTIBANDED ORIENTATION DUE TO SHORTER FETCH ACROSS THE LAKES. HIGH PRESSURE OVER THE OHIO VALLEY WILL EXPAND NORTH AND EAST THROUGH THIS AFTERNOON AND SHOULD WEAKEN THE LAKE SNOWS SOME FROM WHAT WE SAW LAST NIGHT AS THE CAPPING INVERSION LOWERS TO AROUND 8KFT. KBUF RADAR SHOWS A NARROW BAND OF SNOW WITH A GEORGIAN BAY CONNECTION EXTENDING FROM NIAGARA COUNTY SOUTHEAST TO NORTHERN ERIE...GENESEE AND LIVINGSTON COUNTIES. THIS SHOULD CONTINUE TO SETTLE SOUTH THROUGH THIS MORNING WHICH WOULD BRING IT ACROSS METRO BUFFALO AND INTO WYOMING COUNTIES. THIS BAND COULD BRING A BRIEF PERIOD OF INTENSE SNOWS WITH REDUCED VISIBILITY AND A QUICK FRESH COATING OF MAYBE AN INCH OF SNOW AS IT SHIFTS SOUTH. ACROSS THE SOUTHERN LAKE ONTARIO SHORELINE MULTIPLE NARROW BANDS OF LAKE EFFECT SNOW WILL CONTINUE TO IMPACT THE SOUTHERN SHORELINE COUNTIES WHERE WARNINGS WILL REMAIN UP. AN ADDITIONAL INCH OR TWO OF SNOW IS POSSIBLE FROM NIAGARA EAST TO MONROE COUNTIES FROM THESE LAKE SNOWS. FURTHER SOUTH...LAKE SNOWS HAVE LARGELY SETTLED SOUTH TOWARD ERIE PA WITH JUST SOME SCATTERED SNOW SHOWERS ACROSS THE SOUTHERN TIER. THE LATEST HRRR MODEL INDICATES THE NARROW BAND OF SNOW NEAR ERIE WILL SHIFT BACK NORTH ACROSS CHAUTAUQUA AND CATTARAUGUS COUNTIES THIS AFTERNOON WITH A POTENTIAL FOR 2-3 ADDITIONAL INCHES OF SNOW WHICH IS WHY THE LAKE EFFECT SNOW WARNINGS WILL REMAIN IN EFFECT DESPITE THIS THE CURRENT LULL IN ACTIVITY. KTYX RADAR CONTINUES TO SHOW SEVERAL NARROW BANDS OF LAKE EFFECT SNOW IMPACTING NORTHEAST WAYNE...NORTHERN CAYUGA AND OSWEGO COUNTY WHICH MAY BRING AN ADDITIONAL 1-3 INCHES THROUGH TODAY. THERE ARE ALSO SOME LIGHT SNOW SHOWERS FURTHER NORTH DRIFTING ACROSS JEFFERSON AND LEWIS COUNTIES WHICH SHOULD ONLY BRING UP TO AN ADDITIONAL INCH THROUGH TODAY. OUTSIDE OF THE MAIN LAKE EFFECT SNOW AREAS...THE REMAINDER OF THE REGION WILL JUST EXPERIENCE MUCH LIGHTER AND MUCH MORE SCATTERED TRANSIENT LAKE AND OROGRAPHICALLY-DRIVEN LIGHT SNOW SHOWERS...WITH ONLY MINOR ADDITIONAL ACCUMULATIONS EXPECTED. OTHERWISE IT WILL BE COLD AND ON THE BRISK SIDE AGAIN...WITH DAYTIME HIGHS ONLY RANGING FROM AROUND 10 ABOVE ACROSS THE HIGHEST TERRAIN TO THE MID TEENS ELSEWHERE. TONIGHT...A CONTINUED WEST-NORTHWESTERLY FLOW WILL CONTINUE TO MAINTAIN WEAKER LAKE SNOWS SOUTHEAST OF THE LAKES FOR A GOOD PORTION OF THIS EVENING...WITH THIS ACTIVITY BEING HELD MORE IN CHECK BY THE AFOREMENTIONED LOWERING CAPPING INVERSION... WHICH WILL RUN BETWEEN 3 AND 5 KFT OFF LAKE ERIE...AND WILL DROP TO BETWEEN 4 AND 5 KFT OFF LAKE ONTARIO. AFTER THAT TIME...GRADUAL BACKING OF THE LOW LEVEL FLOW TO WESTERLY AND THEN WEST-SOUTHWESTERLY IN ADVANCE OF AN APPROACHING ARCTIC FRONT WILL RESULT IN THE LAKE BANDS SLOWLY MIGRATING NORTHWARD THROUGH THE BALANCE OF THE NIGHT... WITH THE LAKE ERIE ACTIVITY REACHING THE BUFFALO SOUTHTOWNS...AND THE LAKE ONTARIO LAKE SNOWS REACHING THE TUG HILL REGION BY DAYBREAK. WHILE A CONTINUED LOWER CAP AND INCREASING AMOUNTS OF DIRECTIONAL SHEAR BELOW IT SHOULD KEEP THE MIGRATING LAKE SNOWS FROM BECOMING TERRIBLY ORGANIZED...THE GRADUALLY INCREASING FETCH ACROSS BOTH LAKES SHOULD ALLOW FOR AT LEAST SOME INCREASE IN STRENGTH LATE...ENOUGH FOR THE BANDS TO PRODUCE AN ADDITIONAL INCH OR TWO OF ACCUMULATION DURING THEIR NORTHWARD MIGRATION. AT THIS POINT IT APPEARS THAT THE MORE SIGNIFICANT ACCUMULATIONS FROM THESE WILL HOLD OFF UNTIL DURING THE DAY ON FRIDAY...WHEN DEEPENING MOISTURE AND A RISING CAP OUT IN ADVANCE OF THE APPROACHING ARCTIC BOUNDARY SHOULD ALLOW FOR A NOTEWORTHY UPTICK IN BAND ORGANIZATION...MORE ON WHICH IS DISCUSSED IN THE SHORT TERM SECTION BELOW. OUTSIDE OF THE LAKE SNOWS...EXPECT A QUIET AND LARGELY DRY NIGHT TONIGHT...WITH LOWS RANGING FROM AROUND ZERO ACROSS THE NORTH COUNTRY TO THE 5 TO 10 ABOVE RANGE ELSEWHERE. GIVEN A DEVELOPING WARM AIR ADVECTION REGIME...THESE WILL LIKELY OCCUR AROUND MIDNIGHT...BEFORE GIVING WAY TO SLOWLY RISING TEMPERATURES OVERNIGHT. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... LAKE SNOWS WILL REORGANIZE AND INTENSIFY FRIDAY AS THE FLOW BACKS TO SOUTHWEST IN RESPONSE TO A WEAK LOW DROPPING SOUTH FROM CANADA AND AHEAD OF THE ADVANCING ARCTIC BOUNDARY. OFF LAKE ERIE...FORECAST SOUNDINGS CONTINUE TO SHOW A FAIRLY WELL ALIGNED SOUTHWEST FLOW LOW LEVEL FLOW DEVELOPING EARLY FRIDAY. INITIALLY MOISTURE WILL BE LIMITED...BUT WITH THE APPROACH OF THE LOW AND LONG FETCH DOWN THE LAKE...EXPECT A FAIRLY CONSOLIDATED AND INTENSE LAKE EFFECT BAND TO DEVELOP. CONSENSUS HIGH RESOLUTION GUIDANCE CONTINUES TO REFLECT THESE TRENDS. THE RGEM ALONG WITH THE NAM/GFS ALL SUGGEST A STRONG CONVERGENCE SHOULD CONTINUE TO LIFT NORTHWARD INTO BUFFALO METRO AREA DURING THE DAY FRIDAY. FAVORABLE LAKE PARAMETERS WILL EXIST WITH PLENTY OF OVER-LAKE INSTABILITY AS INVERSION HEIGHTS APPROACH 10K FEET WITHIN A WELL ALIGNED SOUTHWEST FLOW...WITH THE BAND POSSIBLY EXTENDING INLAND ACROSS WYOMING AND GENESEE COUNTIES...AND EVEN PERHAPS AS FAR NORTH AS NIAGARA AND ORLEANS COUNTIES IF THE FLOW CAN BACK ENOUGH. FOR NOW WILL MAINTAIN THE LAKE EFFECT SNOW DUE TO UNCERTAINTIES IN THE EXACT PLACEMENT OF THE HEAVIEST BAND. OFF LAKE ONTARIO...A WELL ALIGNED SOUTHWESTERLY FLOW IS FORECAST TO DEVELOP FRIDAY SIMILAR TO LAKE ERIE. THIS WILL NOT ONLY TAP INTO MOISTURE FROM AN APPROACHING SHORTWAVE...BUT ALSO MOISTURE FROM WHATEVER FORMS OFF LAKE ERIE. THIS WILL BRING THE POTENTIAL FOR SIGNIFICANT SNOWS ON FRIDAY INTO FRIDAY NIGHT FOR WATERTOWN AND VICINITY...WITH THE BAND POSSIBLY EXTENDING INLAND ACROSS NORTHERN LEWIS COUNTY. 850 MB TEMPERATURES AROUND -16C AND INVERSION HEIGHTS FORECAST TO RISE TO NEARLY 15K FT AND A FAVORABLY DENDRITIC SNOW GROWTH ZONE SHOULD PROVIDE FAVORABLE PARAMETERS FOR SIGNIFICANT SNOWS. WILL MAINTAIN THE LAKE EFFECT SNOW WATCH FOR JEFFERSON COUNTY AND ADD LEWIS COUNTY WITH THE POTENTIAL FOR SIGNIFICANT LAKE SNOWS REACHING THE NORTHERN PART OF THE COUNTY. ON FRIDAY EVENING...A POWERFUL ARCTIC FRONT WILL SURGE SOUTH ACROSS THE REGION. THIS ARCTIC FRONT WILL LIKELY CAPTURE AND MERGE WITH THE LAKE EFFECT SNOW BAND OFF LAKE ONTARIO...WITH A VERY HEAVY SNOW SQUALL PASSING SOUTH ACROSS THE EASTERN LAKE ONTARIO REGION. THIS WILL LIKELY PRODUCE AN INCH OR TWO OF SNOW IN MANY AREAS...WITH LOCALLY HIGHER AMOUNTS SOUTHEAST OF THE LAKES WHERE THE LAKE CONTRIBUTION MAXIMIZES. BEHIND THE ARCTIC FRONT...MULTIPLE STREAMERS OF LAKE EFFECT SNOW SHOWERS WILL DEVELOP SOUTH OF THE LAKES LATE FRIDAY NIGHT AS FLOW BECOMES NORTHWEST AND EVENTUALLY NORTH NORTHWEST. THE FRONT WILL ALSO USHER IN BITTERLY COLD TEMPERATURES WHICH WILL BE BELOW ZERO IN MOST AREAS BY DAYBREAK SATURDAY. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... A FRIGID ARCTIC AIRMASS WILL TAKE HOLD OF THE EASTERN GREAT LAKES AND NEW ENGLAND THIS WEEKEND. A CONSENSUS OF 12Z GUIDANCE DROPS 850MB TEMPERATURES TO AROUND -30C AT BUFFALO DURING THE DAY AT BUFFALO...WITH -33C ACROSS THE EASTERN LAKE ONTARIO REGION. THE COLDEST TEMPERATURE EVER RECORDED AT 850MB ON A KBUF SOUNDING IN THE MONTH OF FEBRUARY IS -28C...AND THE COLDEST EVER RECORDED FOR ANY MONTH IS -32C. THIS WILL RESULT IN BITTERLY COLD TEMPERATURES DURING THE DAY SATURDAY WITH DAYTIME TEMPERATURES STRUGGLING TO RISE ABOVE ZERO. DAYTIME HIGHS WILL ALMOST CERTAINLY BE BELOW ZERO IN THE EASTERN LAKE ONTARIO REGION. PERSISTENT WINDS OF 10 TO 15 MPH ON SATURDAY NIGHT WILL LIMIT RADIATIONAL COOLING...BUT EVEN SO IT WILL BE VERY COLD WITH BELOW ZERO LOWS REGION-WIDE. LOWS OF -20F OR COLDER ARE POSSIBLE ACROSS THE NORTH COUNTRY WITH NO MODERATING LAKE INFLUENCE. THE COMBINATION OF MODERATE WINDS AND FRIGID TEMPERATURES WILL PRODUCE DANGEROUSLY COLD WIND CHILLS LATE FRIDAY NIGHT THROUGH EARLY SUNDAY MORNING. ISSUING A WIND CHILL WATCH FOR THE ENTIRE CWA...AREAS NEAR THE LAKESHORES MAY ONLY REACH ADVISORY CRITERIA HOWEVER NEED TO HIGHLIGHT THIS DANGEROUSLY COLD WEATHER. THE FRIGID NORTH FLOW OVER THE LAKES WILL PRODUCE WIDESPREAD LAKE EFFECT SNOW SHOWERS ACROSS WESTERN AND CENTRAL NY. DESPITE THE EXTREME INSTABILITY...AIRMASSES THIS COLD ARE ALSO VERY DRY AND TEMPERATURES BECOME TOO COLD FOR DENDRITES. THIS WILL FORCE SNOWFLAKES TO BE VERY SMALL AND LIMIT ACCUMULATIONS...ALTHOUGH SEVERAL INCHES ARE LIKELY SOUTH OF BOTH LAKES. THE LAKE EFFECT SNOW WILL DIMINISH IN COVERAGE AND INTENSITY SUNDAY. 12Z GUIDANCE IS A BIT FASTER MOVING THE SURFACE RIDGE ACROSS THE REGION...WITH LAKE EFFECT SNOW LIKELY TO TAPER OFF BY SUNDAY NIGHT. AFTER THIS THERE IS GENERAL MODEL AGREEMENT THAT TEMPERATURES WILL WARM BACK TO NEAR NORMAL EARLY NEXT WEEK. HOWEVER...THE 12Z ECMWF IS SIGNIFICANTLY DIFFERENT FROM THE GFS/GGEM. THE ECMWF HAS CONSISTENTLY DEVELOPED A STRONG WAVE OF LOW PRESSURE WITH SIGNIFICANT QPF ACROSS OUR REGION WHICH WOULD FALL AS RAIN OR SNOW. THE GGEM/GFS HAVE THIS SYSTEM BUT KEEP IT WELL TO OUR EAST...AND INSTEAD ARE A BIT COLDER WITH A CHANCE FOR LIGHT SNOW SHOWERS. THE FORECAST WILL REFLECT A CONSENSUS BETWEEN THIS GUIDANCE...WITH NEAR NORMAL TEMPERATURES AND CHANCE POPS. && .AVIATION /16Z THURSDAY THROUGH MONDAY/... LAKE EFFECT SNOWS AND ATTENDANT IFR/LIFR WILL BE FOUND EAST- SOUTHEAST OF THE LAKES TODAY AND INTO THIS EVENING...WITH MVFR/VFR CONDITIONS AND MUCH MORE SCATTERED SNOW SHOWERS PREVAILING ELSEWHERE. EXPECT THE MOST SIGNIFICANT LAKE SNOWS OF THE DAY TO COME THIS MORNING...WITH THE ACTIVITY THEN GRADUALLY WEAKENING FROM WEST TO EAST THIS AFTERNOON AND EVENING IN CONJUNCTION WITH DIMINISHING UPSTREAM CONNECTIONS...THE INTRUSION OF DRIER AIR ALOFT...AND A LOWERING CAPPING INVERSION. FROM THE LATE EVENING HOURS ON THROUGH THE REMAINDER OF TONIGHT... GRADUAL BACKING OF THE LOW LEVEL FLOW TO WESTERLY AND THEN WEST- SOUTHWESTERLY IN ADVANCE OF AN APPROACHING ARCTIC FRONT WILL RESULT IN WEAKER LAKE SNOWS SLOWLY MIGRATING NORTHWARD...WITH THE LAKE ERIE ACTIVITY REACHING THE BUFFALO SOUTHTOWNS...AND THE LAKE ONTARIO LAKE SNOWS REACHING THE TUG HILL REGION BY 12Z FRIDAY. EXPECT IFR/MVFR TO PREVAIL WITHIN THE MIGRATING LAKE SNOWS...WITH GENERAL VFR CONDITIONS THE RULE ELSEWHERE. OUTLOOK... FRIDAY...IFR/MVFR WITH SNOW SHOWERS LIKELY...AND AREAS OF HEAVIER LAKE EFFECT SNOW EAST/NORTHEAST OF THE LAKES. SATURDAY...IFR/MVFR IN LAKE EFFECT SNOW SHOWERS SOUTH OF THE LAKES... WITH MVFR/VFR ACROSS THE NORTH COUNTRY. SUNDAY...A CHANCE OF IFR/MVFR IN WEAKENING LAKE EFFECT SNOW SHOWERS SOUTH OF THE LAKES...OTHERWISE MVFR/VFR. MONDAY...MAINLY VFR WITH A CHANCE OF SNOW SHOWERS. && .MARINE... A BRISK FLOW OF PROGRESSIVELY COLDER ARCTIC AIR WILL CONTINUE TO OVERSPREAD THE REGION THROUGH THE WEEKEND...RESULTING IN A PROLONGED PERIOD OF ADVISORY-WORTHY WINDS AND WAVES ACROSS THE LOWER LAKES. IN ADDITION TO THE ABOVE...THE PASSAGE OF AN ARCTIC COLD FRONT LATER FRIDAY AFTERNOON AND FRIDAY EVENING WILL ALSO USHER IN A TRULY FRIGID AIRMASS FOR LATER FRIDAY NIGHT AND THE UPCOMING WEEKEND...WHICH IN CONJUNCTION WITH THE AFOREMENTIONED WINDS WILL RESULT IN A GREATLY HEIGHTENED POTENTIAL FOR HEAVY FREEZING SPRAY. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH LATE FRIDAY NIGHT FOR NYZ007-008. WIND CHILL WATCH FROM LATE FRIDAY NIGHT THROUGH SUNDAY MORNING FOR NYZ001>008-010>014-019>021-085. LAKE EFFECT SNOW WARNING UNTIL 4 AM EST FRIDAY FOR NYZ004>006. LAKE EFFECT SNOW WARNING UNTIL 4 PM EST THIS AFTERNOON FOR NYZ001>003-019-020. LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH FRIDAY EVENING FOR NYZ012-019-020-085. LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH FRIDAY EVENING FOR NYZ010-011. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ020. SMALL CRAFT ADVISORY UNTIL 7 PM EST SATURDAY FOR LEZ040- 041. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LOZ030. SMALL CRAFT ADVISORY UNTIL 7 PM EST SATURDAY FOR LOZ042>045. && $$ SYNOPSIS...JJR NEAR TERM...JJR/SMITH SHORT TERM...TMA LONG TERM...APFFEL/LEVAN AVIATION...JJR/SMITH MARINE...JJR/SMITH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
639 AM EST THU FEB 11 2016 .SYNOPSIS... LAKE EFFECT SNOW WILL BE HEAVY AT TIMES THROUGH TONIGHT IN PARTS OF CENTRAL NEW YORK...GENERALLY SOUTHEAST OF LAKE ONTARIO. SCATTERED SNOW SHOWERS AND FLURRIES WILL OCCUR ELSEWHERE WITH LIGHT ACCUMULATIONS. A STRONG ARCTIC FRONT WILL DROP THROUGH THE REGION LATE FRIDAY...BRINGING THE COLDEST AIR MASS SINCE LAST WINTER. WIND CHILLS WILL BE DANGEROUSLY LOW...WELL BELOW ZERO...SATURDAY THROUGH SATURDAY NIGHT. A MODERATING TREND IS EXPECTED EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 315 AM UPDATE... WANTED TO SEND OUT AN "EARLY" UPDATE TO REFLECT ON THE CURRENT SITUATION REGARDING OUR LAKE EFFECT EVENT. WILL SEND OUT A SEPARATE AFD FOR THE SHORT TERM PERIOD TO GO OVER THE DANGEROUS COLD OVER THE WEEKEND. FIRST THINGS FIRST, THE LAKE EFFECT. SEE OUR WEBSITE FOR OUR LATEST SNOWFALL MAP THAT I JUST POSTED. WARNINGS AND ADVISORIES WILL REMAIN IN PLACE. I DID SHIFT THE HEAVIER AXIS OF SNOW FARTHER NORTH, TO REFLECT RADAR TRENDS FROM YESTERDAY EVENING THROUGH NOW. THE CHANGE WILL INCREASE AMOUNTS IN WEST CENTRAL ONEIDA COUNTY QUITE A BIT, WHILE DROPPING OFF SHARPLY TOWARD THE CITY OF UTICA. I KEPT NORTHERN ONONDAGA IN THE HIGHER AMOUNTS AS WELL, ALTHOUGH THEY WILL PROBABLY END UP BEING LOWER OVERALL THAN WEST CENTRAL ONEIDA. THE HIGHER TOTALS ACROSS NORTHERN ONONDAGA COUNTY IS A REFLECTION OF WHAT WE EXPECT TO COME, NOT UNDERSTANDING WE HAVEN`T SEE MUCH SNOW HERE YET. WHILE THE FORECAST GOING FORECAST IS LARGELY UNCHANGED FROM THIS POINT FORWARD, WE HAVEN`T SEE MUCH SNOW AT ALL FROM THE NEAR THE CITY OF SYRACUSE SOUTH. THUS I HAVE ADJUSTED TOTALS DOWN ACROSS SOUTHERN ONONDAGA/MADISON COUNTIES, ALONG WITH NORTHERN CORTLAND/CHENANGO/OTSEGO. WHILE THE BAND HAS BEEN MAINLY NORTH OF KSYR AND HAS EVEN WAVERED BACK INTO NORTHERN ONEIDA, CONFIDENCE IS HIGH THAT THE BAND WILL SINK SOUTH BETWEEN 09Z AND 12Z. THE LATEST HRRR AND RAP SOUNDINGS SHOW A MEAN WIND OF 275 NOW, ABRUPTLY SHIFTING TOWARD 290 BY 12Z, THEN LOCKING IN FOR THE REST OF THE DAY. KBUF RADAR SHOWS THE WESTERN SIDE OF THE BAND NEAR KROC IS ALREADY SHOWING SIGNS OF THIS CHANGE AND WILL FOLLOW. SO WHILE THE EVENT HAS PLAYED OUT WELL THUS FAR ACROSS WEST CENTRAL ONEIDA COUNTY, MANY IN METRO SYRACUSE AND ALONG THE THRUWAY MAY BE WONDERING WHAT LAKE SNOWS? DON`T LET YOUR GUARD DOWN YET AS HEAVIER SNOWS WILL SHIFT SOUTH TODAY. WITH INVERSION HEIGHTS GRADUALLY LOWERING TOWARD 5KFT BY LATE AFTERNOON, THE OVERALL INTENSITY WILL BE HIGHEST THIS MORNING, THEN A GRADUAL WEAKENING TREND INTO EARLY TONIGHT. SNOWFALL RATES THROUGH MID MORNING WILL STILL BE IN THE 1 TO 2"+ RANGE. THE FLOW REMAINS AROUND 290-300 THROUGH 06Z TONIGHT, BEFORE THE FLOW BACKS ENOUGH TOWARD THE SOUTHWEST TO LIFT THE BAND OUT OF OUR AREA TOWARD DAYBREAK FRIDAY. IN ALL A WIDESPREAD, LONG DURATION 6"+ LOOKS GOOD ACROSS MUCH OF CENTRAL NY, WITH CLOSER TO 1 1/2 FEET OVER WESTERN ONEIDA COUNTY. I CONTINUE TO MENTION BLOW AND DRIFTING SNOW WITHIN AND NEAR THE SNOW BANDS THEMSELVES. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... 4 AM UPDATE... OVERVIEW...SNOW SQUALLS LIKELY FRIDAY NIGHT ALONG AN ARCTIC FRONT THAT WILL DELIVER BRUTAL COLD SATURDAY AND SATURDAY NIGHT, WHICH WILL RIVAL WHAT WE SAW LAST FEBRUARY. FRIDAY/FRIDAY NIGHT....MOST OF FRIDAY WILL BE QUIET WITH A SOUTHWEST FLOW AHEAD OF AN ARCTIC FRONT. THIS FLOW WILL KEEP MOST OF THE AREA DRY THROUGH THE DAYLIGHT HOURS. FRIDAY EVENING THE ARCTIC FRONT WILL CROSS THE AREA BETWEEN 0Z AND 06Z SATURDAY. SNOW SQUALLS LOOK LIKELY, WITH THE POTENTIAL FOR POOR VISIBILITY AND SNOWFALL RATES OF MORE THAN AN INCH PER HOUR. MODEL SOUNDINGS SHOW STEEP LAPSE RATES OF MORE THAN 8.0 C/KM UP THROUGH 650 MB! IN ADDITION STRONG OMEGA (LIFT/RISING AIR IN THE ATMOSPHERE) IS FOUND WITH PLENTY OF MOISTURE RIGHT IN THE SNOW GROWTH REGION. THINK BIG FLAKES, HIGH EFFICIENCY OF ACCUMULATING SNOWS. WILL ADD CHANCE OF HEAVY SNOW FOR THE FRIDAY EVENING FORECAST. SNOWFALL AMOUNTS OF A FEW INCHES LIKELY BUT AGAIN IT WILL BE THE RATE OF FALL WHICH WILL CAUSE POOR VISIBILITIES AND DANGEROUS ROADS. SATURDAY/SATURDAY NIGHT...BRUTAL COLD. 850 TEMPS FALL TO BETWEEN -28C AND -30C! "OFFICIAL" HIGHS SATURDAY WILL BE IN THE TEENS AT MIDNIGHT FRIDAY NIGHT, WITH TEMPS FALLING INTO THE SINGLE DIGITS BY SATURDAY AFTERNOON. SOME AREAS WILL LIKELY DROP BELOW ZERO FOR TEMPS SATURDAY AFTERNOON, ESPECIALLY IN NY STATE! THIS ALONE IS COLD BUT A PRESSURE GRADIENT BETWEEN AN OCEAN STORM AND HIGH PRESSURE OVER THE MIDWEST WILL PRODUCE ENOUGH WIND FOR WIND CHILL READINGS BETWEEN -10 AND -30. WE WILL CONTINUE TO HIGHLIGHT THE HIGH CONFIDENCE FOR EXTREME COLD AND DANGEROUS WIND CHILLS IN OUR HWO, ON SOCIAL MEDIA, AND IN OUR ONLINE BRIEFING PACKAGE FOUND AT WEATHER.GOV/BGM UNDER WEATHER HAZARD BRIEFING AT THE BOTTOM OF THE PAGE. LOWS SATURDAY NIGHT WILL BE BELOW ZERO EVERYWHERE, WITH -20 READINGS POSSIBLE IN OUR COLDER SPOTS. IMPRESSIVE COLD AND THE ONLY SILVER LINING IS THE FACT IT WON`T LAST LONG. SEE BELOW FOR MORE ON MILDER WEATHER NEXT WEEK. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... 430 PM UPDATE... ONLY SOME MODERATION IN TEMPERATURES EXPECTED SUNDAY AS ARCTIC HIGH SLIDES EAST RIGHT OVER THE AREA BY LATE DAY. WINDS WILL BE SIGNIFICANTLY LESS...YET WE START THE DAY WITH SUBZERO TEMPERATURES SO VERY COLD ANYWAYS. STILL EXPECT SOME LAKE EFFECT, THOUGH THIS WILL TEND TO BE DIMINISHING THROUGH THE DAY HAS THE HIGH MOVES IN. HIGHS LOOK TO RANGE FROM THE SINGLE DIGITS THROUGH MUCH OF THE CATSKILLS NORTH TO THE TUG HILL WITH LOW TO MID TEENS ELSEWHERE. PATTERN WILL BE PROGRESSIVE ENOUGH FOR CORE OF ARCTIC AIR TO MOVE OUT EARLY NEXT WEEK WITH MORE SIGNIFICANT MODERATION BACK TO AT LEAST SEASONAL. MODELS INDICATE THE NEXT UPPER TROUGH MOVING INTO THE EAST WITH LOW PRESSURE DEVELOPMENT BUT THERE IS MODEL DISAGREEMENT ON TIMING, TRACK, AND INTENSITY. FOR NOW, INDICATE CHANCE OF SNOW IN GRIDS FOR MONDAY THROUGH WEDNESDAY BUT THERE IS A CHANCE LOW COULD TRACK FAR ENOUGH WEST TO BRING RAIN TO SOME AREAS AS EARLY AS TUESDAY. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... LE SNOW BAND IS XPCTD TO DROP SWRD ACROSS RME AND STALL IN THE SYR AREA FOR SVRL HRS TODAY. THIS WEILL BRING BRIEF IFR CONDS TO RME...AND PROLONGED IFR CIGS AND VSBY TO SYR FOR MUCH OF THE DAY. ELSEWHERE...SCT SNOW SHWRS WILL BRING BRIEF LWR CONDS BUT MUCH OF THE DAY WILL BE VFR ELSEWHERE. BAND IS XPCTD TO LIFT NWRD LTR THIS EVE LVG VFR CONDS AT ALL STATIONS. .OUTLOOK... FRI THRU SUN...VARIABLE CEILING AND VSBY RESTRICTIONS DUE TO PERIODS OF WIDESPREAD LIGHT SNOW AND BANDS OF MORE INTENSE LAKE EFFECT SNOW...ESPECIALLY NORTHERN HALF. LESS COVERAGE AND TIME AFFECTED FOR THE SOUTHERN AREAS. MON...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ016-017-044>046. LAKE EFFECT SNOW WARNING UNTIL 4 AM EST FRIDAY FOR NYZ009-018- 036-037. && $$ SYNOPSIS...HEDEN NEAR TERM...HEDEN SHORT TERM...HEDEN LONG TERM...MDP AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
415 AM EST THU FEB 11 2016 .SYNOPSIS... LAKE EFFECT SNOW WILL BE HEAVY AT TIMES THROUGH TONIGHT IN PARTS OF CENTRAL NEW YORK...GENERALLY SOUTHEAST OF LAKE ONTARIO. SCATTERED SNOW SHOWERS AND FLURRIES WILL OCCUR ELSEWHERE WITH LIGHT ACCUMULATIONS. A STRONG ARCTIC FRONT WILL DROP THROUGH THE REGION LATE FRIDAY...BRINGING THE COLDEST AIR MASS SINCE LAST WINTER. WIND CHILLS WILL BE DANGEROUSLY LOW...WELL BELOW ZERO...SATURDAY THROUGH SATURDAY NIGHT. A MODERATING TREND IS EXPECTED EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 315 AM UPDATE... WANTED TO SEND OUT AN "EARLY" UPDATE TO REFLECT ON THE CURRENT SITUATION REGARDING OUR LAKE EFFECT EVENT. WILL SEND OUT A SEPARATE AFD FOR THE SHORT TERM PERIOD TO GO OVER THE DANGEROUS COLD OVER THE WEEKEND. FIRST THINGS FIRST, THE LAKE EFFECT. SEE OUR WEBSITE FOR OUR LATEST SNOWFALL MAP THAT I JUST POSTED. WARNINGS AND ADVISORIES WILL REMAIN IN PLACE. I DID SHIFT THE HEAVIER AXIS OF SNOW FARTHER NORTH, TO REFLECT RADAR TRENDS FROM YESTERDAY EVENING THROUGH NOW. THE CHANGE WILL INCREASE AMOUNTS IN WEST CENTRAL ONEIDA COUNTY QUITE A BIT, WHILE DROPPING OFF SHARPLY TOWARD THE CITY OF UTICA. I KEPT NORTHERN ONONDAGA IN THE HIGHER AMOUNTS AS WELL, ALTHOUGH THEY WILL PROBABLY END UP BEING LOWER OVERALL THAN WEST CENTRAL ONEIDA. THE HIGHER TOTALS ACROSS NORTHERN ONONDAGA COUNTY IS A REFLECTION OF WHAT WE EXPECT TO COME, NOT UNDERSTANDING WE HAVEN`T SEE MUCH SNOW HERE YET. WHILE THE FORECAST GOING FORECAST IS LARGELY UNCHANGED FROM THIS POINT FORWARD, WE HAVEN`T SEE MUCH SNOW AT ALL FROM THE NEAR THE CITY OF SYRACUSE SOUTH. THUS I HAVE ADJUSTED TOTALS DOWN ACROSS SOUTHERN ONONDAGA/MADISON COUNTIES, ALONG WITH NORTHERN CORTLAND/CHENANGO/OTSEGO. WHILE THE BAND HAS BEEN MAINLY NORTH OF KSYR AND HAS EVEN WAVERED BACK INTO NORTHERN ONEIDA, CONFIDENCE IS HIGH THAT THE BAND WILL SINK SOUTH BETWEEN 09Z AND 12Z. THE LATEST HRRR AND RAP SOUNDINGS SHOW A MEAN WIND OF 275 NOW, ABRUPTLY SHIFTING TOWARD 290 BY 12Z, THEN LOCKING IN FOR THE REST OF THE DAY. KBUF RADAR SHOWS THE WESTERN SIDE OF THE BAND NEAR KROC IS ALREADY SHOWING SIGNS OF THIS CHANGE AND WILL FOLLOW. SO WHILE THE EVENT HAS PLAYED OUT WELL THUS FAR ACROSS WEST CENTRAL ONEIDA COUNTY, MANY IN METRO SYRACUSE AND ALONG THE THRUWAY MAY BE WONDERING WHAT LAKE SNOWS? DON`T LET YOUR GUARD DOWN YET AS HEAVIER SNOWS WILL SHIFT SOUTH TODAY. WITH INVERSION HEIGHTS GRADUALLY LOWERING TOWARD 5KFT BY LATE AFTERNOON, THE OVERALL INTENSITY WILL BE HIGHEST THIS MORNING, THEN A GRADUAL WEAKENING TREND INTO EARLY TONIGHT. SNOWFALL RATES THROUGH MID MORNING WILL STILL BE IN THE 1 TO 2"+ RANGE. THE FLOW REMAINS AROUND 290-300 THROUGH 06Z TONIGHT, BEFORE THE FLOW BACKS ENOUGH TOWARD THE SOUTHWEST TO LIFT THE BAND OUT OF OUR AREA TOWARD DAYBREAK FRIDAY. IN ALL A WIDESPREAD, LONG DURATION 6"+ LOOKS GOOD ACROSS MUCH OF CENTRAL NY, WITH CLOSER TO 1 1/2 FEET OVER WESTERN ONEIDA COUNTY. I CONTINUE TO MENTION BLOW AND DRIFTING SNOW WITHIN AND NEAR THE SNOW BANDS THEMSELVES. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... 4 AM UPDATE... OVERVIEW...SNOW SQUALLS LIKELY FRIDAY NIGHT ALONG AN ARCTIC FRONT THAT WILL DELIVER BRUTAL COLD SATURDAY AND SATURDAY NIGHT, WHICH WILL RIVAL WHAT WE SAW LAST FEBRUARY. FRIDAY/FRIDAY NIGHT....MOST OF FRIDAY WILL BE QUIET WITH A SOUTHWEST FLOW AHEAD OF AN ARCTIC FRONT. THIS FLOW WILL KEEP MOST OF THE AREA DRY THROUGH THE DAYLIGHT HOURS. FRIDAY EVENING THE ARCTIC FRONT WILL CROSS THE AREA BETWEEN 0Z AND 06Z SATURDAY. SNOW SQUALLS LOOK LIKELY, WITH THE POTENTIAL FOR POOR VISIBILITY AND SNOWFALL RATES OF MORE THAN AN INCH PER HOUR. MODEL SOUNDINGS SHOW STEEP LAPSE RATES OF MORE THAN 8.0 C/KM UP THROUGH 650 MB! IN ADDITION STRONG OMEGA (LIFT/RISING AIR IN THE ATMOSPHERE) IS FOUND WITH PLENTY OF MOISTURE RIGHT IN THE SNOW GROWTH REGION. THINK BIG FLAKES, HIGH EFFICIENCY OF ACCUMULATING SNOWS. WILL ADD CHANCE OF HEAVY SNOW FOR THE FRIDAY EVENING FORECAST. SNOWFALL AMOUNTS OF A FEW INCHES LIKELY BUT AGAIN IT WILL BE THE RATE OF FALL WHICH WILL CAUSE POOR VISIBILITIES AND DANGEROUS ROADS. SATURDAY/SATURDAY NIGHT...BRUTAL COLD. 850 TEMPS FALL TO BETWEEN -28C AND -30C! "OFFICIAL" HIGHS SATURDAY WILL BE IN THE TEENS AT MIDNIGHT FRIDAY NIGHT, WITH TEMPS FALLING INTO THE SINGLE DIGITS BY SATURDAY AFTERNOON. SOME AREAS WILL LIKELY DROP BELOW ZERO FOR TEMPS SATURDAY AFTERNOON, ESPECIALLY IN NY STATE! THIS ALONE IS COLD BUT A PRESSURE GRADIENT BETWEEN AN OCEAN STORM AND HIGH PRESSURE OVER THE MIDWEST WILL PRODUCE ENOUGH WIND FOR WIND CHILL READINGS BETWEEN -10 AND -30. WE WILL CONTINUE TO HIGHLIGHT THE HIGH CONFIDENCE FOR EXTREME COLD AND DANGEROUS WIND CHILLS IN OUR HWO, ON SOCIAL MEDIA, AND IN OUR ONLINE BRIEFING PACKAGE FOUND AT WEATHER.GOV/BGM UNDER WEATHER HAZARD BRIEFING AT THE BOTTOM OF THE PAGE. LOWS SATURDAY NIGHT WILL BE BELOW ZERO EVERYWHERE, WITH -20 READINGS POSSIBLE IN OUR COLDER SPOTS. IMPRESSIVE COLD AND THE ONLY SILVER LINING IS THE FACT IT WON`T LAST LONG. SEE BELOW FOR MORE ON MILDER WEATHER NEXT WEEK. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... 430 PM UPDATE... ONLY SOME MODERATION IN TEMPERATURES EXPECTED SUNDAY AS ARCTIC HIGH SLIDES EAST RIGHT OVER THE AREA BY LATE DAY. WINDS WILL BE SIGNIFICANTLY LESS...YET WE START THE DAY WITH SUBZERO TEMPERATURES SO VERY COLD ANYWAYS. STILL EXPECT SOME LAKE EFFECT, THOUGH THIS WILL TEND TO BE DIMINISHING THROUGH THE DAY HAS THE HIGH MOVES IN. HIGHS LOOK TO RANGE FROM THE SINGLE DIGITS THROUGH MUCH OF THE CATSKILLS NORTH TO THE TUG HILL WITH LOW TO MID TEENS ELSEWHERE. PATTERN WILL BE PROGRESSIVE ENOUGH FOR CORE OF ARCTIC AIR TO MOVE OUT EARLY NEXT WEEK WITH MORE SIGNIFICANT MODERATION BACK TO AT LEAST SEASONAL. MODELS INDICATE THE NEXT UPPER TROUGH MOVING INTO THE EAST WITH LOW PRESSURE DEVELOPMENT BUT THERE IS MODEL DISAGREEMENT ON TIMING, TRACK, AND INTENSITY. FOR NOW, INDICATE CHANCE OF SNOW IN GRIDS FOR MONDAY THROUGH WEDNESDAY BUT THERE IS A CHANCE LOW COULD TRACK FAR ENOUGH WEST TO BRING RAIN TO SOME AREAS AS EARLY AS TUESDAY. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... LE BAND WILL LINGER IN THE SYR/RME CORRIDOR AND BRING OCNL IFR CONDS INTO THU. BAND IS XPCTD TO GRADUALLY SLIP SOPUTH AND WILL BRING OCNL MVFR CIGS AND VSBYS TO ITH ANBD BGM LTR IN THE DAY. WEAKENING FLOW AND DRIER AIR WILL ERODE THE LAKE EFFECT LVG GNRL VFR CONDS TO ALL STATIONS AFT 00Z. GUSTY WEST WNDS TODAY WILL BECOME LGTR AFT SUNSET THIS EVE. .OUTLOOK... THU NGT THROUGH SUN...VARIABLE CEILING AND VSBY RESTRICTIONS DUE TO PERIODS OF WIDESPREAD LIGHT SNOW AND BANDS OF MORE INTENSE LAKE EFFECT SNOW...ESPECIALLY NORTHERN HALF. LESS COVERAGE AND TIME AFFECTED FOR THE SOUTHERN AREAS. MON...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ016-017-044>046. LAKE EFFECT SNOW WARNING UNTIL 4 AM EST FRIDAY FOR NYZ009-018- 036-037. && $$ SYNOPSIS...HEDEN NEAR TERM...HEDEN SHORT TERM...HEDEN LONG TERM...MDP AVIATION...DGM/PCF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
320 AM EST THU FEB 11 2016 .SYNOPSIS... LAKE EFFECT SNOW WILL BE HEAVY AT TIMES TONIGHT THROUGH THURSDAY IN PARTS OF CENTRAL NEW YORK...GENERALLY SOUTHEAST OF LAKE ONTARIO. SCATTERED SNOW SHOWERS AND FLURRIES WILL OCCUR ELSEWHERE WITH LIGHT ACCUMULATIONS. A STRONG ARCTIC FRONT WILL DROP THROUGH THE REGION LATE FRIDAY...BRINGING THE COLDEST AIR MASS SINCE LAST WINTER. WIND CHILLS WILL BE DANGEROUSLY LOW...WELL BELOW ZERO...SATURDAY THROUGH SATURDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... 315 AM UPDATE... WANTED TO SEND OUT AN "EARLY" UPDATE TO REFLECT ON THE CURRENT SITUATION REGARDING OUR LAKE EFFECT EVENT. WILL SEND OUT A SEPARATE AFD FOR THE SHORT TERM PERIOD TO GO OVER THE DANGEROUS COLD OVER THE WEEKEND. FIRST THINGS FIRST, THE LAKE EFFECT. SEE OUR WEBSITE FOR OUR LATEST SNOWFALL MAP THAT I JUST POSTED. WARNINGS AND ADVISORIES WILL REMAIN IN PLACE. I DID SHIFT THE HEAVIER AXIS OF SNOW FARTHER NORTH, TO REFLECT RADAR TRENDS FROM YESTERDAY EVENING THROUGH NOW. THE CHANGE WILL INCREASE AMOUNTS IN WEST CENTRAL ONEIDA COUNTY QUITE A BIT, WHILE DROPPING OFF SHARPLY TOWARD THE CITY OF UTICA. I KEPT NORTHERN ONONDAGA IN THE HIGHER AMOUNTS AS WELL, ALTHOUGH THEY WILL PROBABLY END UP BEING LOWER OVERALL THAN WEST CENTRAL ONEIDA. THE HIGHER TOTALS ACROSS NORTHERN ONONDAGA COUNTY IS A REFLECTION OF WHAT WE EXPECT TO COME, NOT UNDERSTANDING WE HAVEN`T SEE MUCH SNOW HERE YET. WHILE THE FORECAST GOING FORECAST IS LARGELY UNCHANGED FROM THIS POINT FORWARD, WE HAVEN`T SEE MUCH SNOW AT ALL FROM THE NEAR THE CITY OF SYRACUSE SOUTH. THUS I HAVE ADJUSTED TOTALS DOWN ACROSS SOUTHERN ONONDAGA/MADISON COUNTIES, ALONG WITH NORTHERN CORTLAND/CHENANGO/OTSEGO. WHILE THE BAND HAS BEEN MAINLY NORTH OF KSYR AND HAS EVEN WAVERED BACK INTO NORTHERN ONEIDA, CONFIDENCE IS HIGH THAT THE BAND WILL SINK SOUTH BETWEEN 09Z AND 12Z. THE LATEST HRRR AND RAP SOUNDINGS SHOW A MEAN WIND OF 275 NOW, ABRUPTLY SHIFTING TOWARD 290 BY 12Z, THEN LOCKING IN FOR THE REST OF THE DAY. KBUF RADAR SHOWS THE WESTERN SIDE OF THE BAND NEAR KROC IS ALREADY SHOWING SIGNS OF THIS CHANGE AND WILL FOLLOW. SO WHILE THE EVENT HAS PLAYED OUT WELL THUS FAR ACROSS WEST CENTRAL ONEIDA COUNTY, MANY IN METRO SYRACUSE AND ALONG THE THRUWAY MAY BE WONDERING WHAT LAKE SNOWS? DON`T LET YOUR GUARD DOWN YET AS HEAVIER SNOWS WILL SHIFT SOUTH TODAY. WITH INVERSION HEIGHTS GRADUALLY LOWERING TOWARD 5KFT BY LATE AFTERNOON, THE OVERALL INTENSITY WILL BE HIGHEST THIS MORNING, THEN A GRADUAL WEAKENING TREND INTO EARLY TONIGHT. SNOWFALL RATES THROUGH MID MORNING WILL STILL BE IN THE 1 TO 2"+ RANGE. THE FLOW REMAINS AROUND 290-300 THROUGH 06Z TONIGHT, BEFORE THE FLOW BACKS ENOUGH TOWARD THE SOUTHWEST TO LIFT THE BAND OUT OF OUR AREA TOWARD DAYBREAK FRIDAY. IN ALL A WIDESPREAD, LONG DURATION 6"+ LOOKS GOOD ACROSS MUCH OF CENTRAL NY, WITH CLOSER TO 1 1/2 FEET OVER WESTERN ONEIDA COUNTY. I CONTINUE TO MENTION BLOW AND DRIFTING SNOW WITHIN AND NEAR THE SNOW BANDS THEMSELVES. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... 430 PM UPDATE... MAIN ATTENTION TURNS TO A SIGNIFICANT BLAST OF ARCTIC AIR...THE COLDEST SINCE LAST WINTER...WHICH WILL PRODUCE DANGEROUSLY LOW WIND CHILLS BY SATURDAY. BEFORE THAT...LAKE EFFECT SNOW WILL CONTINUE INTO THURSDAY EVENING ACROSS THE WARNING ZONES...BUT OVERNIGHT THE LOW LEVEL FLOW WILL BACK WELL AHEAD OF NEXT FRONT...WHICH WILL DIMINISH AND SHIFT LAKE EFFECT SNOW NORTH OF THE AREA. FRIDAY...SURFACE LOW WILL TRACK FROM THE UPPER GREAT LAKES EAST ACROSS NEARBY SOUTHERN CANADA AND DRAG AN ARCTIC FRONT THROUGH THE REGION FRIDAY EVENING. THE FRONT LOOKS PRIMED TO PICK UP GREAT LAKES MOISTURE AS IT DROPS. IT LOOKS QUITE PROBABLE THAT THE FRONT WILL BE ACCOMPANIED BY A PRETTY STOUT SNOW SQUALL FRIDAY EVENING. WHILE IT MAY ONLY PRODUCE A QUICK INCH OR SO OF ACCUMULATION...IT WILL LIKELY COME DOWN VERY ABRUPTLY. FORECAST MODELS IN GREAT OVERALL AGREEMENT ON 500 MB TROUGH AND ASSOCIATED UPPER LOW DROPPING INTO THE NORTHEAST WITH 1000-500 MB THICKNESS PROGGED TO ONLY BE AROUND 490 DM AND 850 MB TEMPS AROUND -30 C...ABOUT AS COLD AS IS SEEN AROUND HERE. VERY RUDE AWAKENING SATURDAY MORNING...WITH WIND CHILLS ALREADY WELL BELOW ZERO...AND ACTUAL TEMPERATURES MAINLY SINGLE DIGITS AND FALLING THROUGH THE DAY. WIND CHILLS TEENS-20S BELOW ZERO ARE FIGURED BY SATURDAY AFTERNOON...SOME PLACES EVEN COLDER SATURDAY NIGHT. UNPROTECTED VULNERABLE PLUMBING MAY EXPERIENCE FREEZING/BREAKING...AND ANYONE NOT TAKING PROPER PRECAUTIONS OUTSIDE COULD EXPERIENCE FROSTBITE HYPOTHERMIA. THIS ARCTIC AIR MASS SHOULD BE TAKEN SERIOUSLY. DENDRITIC GROWTH LAYER WILL ACTUALLY CRASH TO THE GROUND IN THIS ARCTIC AIR MASS...SO LAKE EFFECT WILL BE LIMITED YET DRY FLUFFY FLURRIES CAN BE EXPECTED OUT OF JUST ABOUT ANY CLOUD. SATURDAY NIGHT WILL BE THE COLDEST NIGHT WITH WIDESPREAD SUBZERO LOWS EXPECTED...POSSIBLY EVEN MINUS DOUBLE DIGIT LOWS...ESPECIALLY IN EASTERN ZONES NORTH THROUGH ONEIDA COUNTY. WINDS LOOK TO STAY UP DUE TO CONTINUING GRADIENT BETWEEN LOW TO THE EAST AND HIGH TO THE WEST AND THIS WILL MAKE IT FEEL EVEN COLDER BUT MAY ACT TO LIMIT TEMPS FROM BOTTOMING OUT TO REALLY EXTREME VALUES. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... 430 PM UPDATE... ONLY SOME MODERATION IN TEMPERATURES EXPECTED SUNDAY AS ARCTIC HIGH SLIDES EAST RIGHT OVER THE AREA BY LATE DAY. WINDS WILL BE SIGNIFICANTLY LESS...YET WE START THE DAY WITH SUBZERO TEMPERATURES SO VERY COLD ANYWAYS. STILL EXPECT SOME LAKE EFFECT, THOUGH THIS WILL TEND TO BE DIMINISHING THROUGH THE DAY HAS THE HIGH MOVES IN. HIGHS LOOK TO RANGE FROM THE SINGLE DIGITS THROUGH MUCH OF THE CATSKILLS NORTH TO THE TUG HILL WITH LOW TO MID TEENS ELSEWHERE. PATTERN WILL BE PROGRESSIVE ENOUGH FOR CORE OF ARCTIC AIR TO MOVE OUT EARLY NEXT WEEK WITH MORE SIGNIFICANT MODERATION BACK TO AT LEAST SEASONAL. MODELS INDICATE THE NEXT UPPER TROUGH MOVING INTO THE EAST WITH LOW PRESSURE DEVELOPMENT BUT THERE IS MODEL DISAGREEMENT ON TIMING, TRACK, AND INTENSITY. FOR NOW, INDICATE CHANCE OF SNOW IN GRIDS FOR MONDAY THROUGH WEDNESDAY BUT THERE IS A CHANCE LOW COULD TRACK FAR ENOUGH WEST TO BRING RAIN TO SOME AREAS AS EARLY AS TUESDAY. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... LE BAND WILL LINGER IN THE SYR/RME CORRIDOR AND BRING OCNL IFR CONDS INTO THU. BAND IS XPCTD TO GRADUALLY SLIP SOPUTH AND WILL BRING OCNL MVFR CIGS AND VSBYS TO ITH ANBD BGM LTR IN THE DAY. WEAKENING FLOW AND DRIER AIR WILL ERODE THE LAKE EFFECT LVG GNRL VFR CONDS TO ALL STATIONS AFT 00Z. GUSTY WEST WNDS TODAY WILL BECOME LGTR AFT SUNSET THIS EVE. .OUTLOOK... THU NGT THROUGH SUN...VARIABLE CEILING AND VSBY RESTRICTIONS DUE TO PERIODS OF WIDESPREAD LIGHT SNOW AND BANDS OF MORE INTENSE LAKE EFFECT SNOW...ESPECIALLY NORTHERN HALF. LESS COVERAGE AND TIME AFFECTED FOR THE SOUTHERN AREAS. MON...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ016-017-044>046. LAKE EFFECT SNOW WARNING UNTIL 4 AM EST FRIDAY FOR NYZ009-018- 036-037. && $$ SYNOPSIS...RRM NEAR TERM...HEDEN SHORT TERM...MDP LONG TERM...MDP AVIATION...DGM/PCF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
940 PM EST FRI FEB 12 2016 .SYNOPSIS...ARCTIC HIGH PRESSURE WILL BUILD OVER THE REGION OVER THE WEEKEND. A DEVELOPING STORM SYSTEM WILL APPROACH FROM THE WEST SUNDAY NIGHT AND THEN MOVE EASTWARD THROUGH THE AREA MONDAY THROUGH TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 940 PM FRIDAY... STARTING TO FINALLY SEE BETTER WEST TO EAST CLEARING OF MOISTURE AROUND 6000-7000 FT AS A JET ON THE BACK SIDE OF THE UPPER TROUGH APPROACHES AND NORTHWEST FLOW STRENGTHENS. LOW-LEVEL MOISTURE IS STILL MORE PREVALENT ON THE COASTAL PLAIN WHERE SOME SUB-1000 FT STRATUS IS LINGERING. A PERIOD OF PATCHY FOG MAY DEVELOP IN THE SOUTHERN COASTAL PLAIN AS THE HIGHER LEVEL CLOUDS CLEARING (HINTED AT BY SREF PROBS AND KFAY/KGSB RAP SOUNDINGS)...BUT IT WOULD LIKELY BE BRIEF...PRIOR TO 06Z...WITH A NORTHWEST WIND AND COLD ADVECTION FORECAST TO SLOWLY STRENGTHEN AFTER MIDNIGHT. OTHERWISE...WHILE WE MAY SEE A SOME PATCHES OF STRATOCU DRIFT ACROSS THE AREA GIVEN ALL THE MOISTURE BANKED UPSTREAM OF THE MOUNTAINS...CLEARING SKIES AND COLD ADVECTION WILL PUSH LOWS INTO THE LOWER 20S NORTH AND WEST TO UPPER 20S SOUTH AND EAST. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 300 PM FRIDAY... AS EAST COAST TROUGH TRIES TO PULL OFF THE COAST...VERY STRONG COLD AIR ADVECTION WILL ENSUE BEHIND THE EXITING COASTAL SYSTEM. WITH VERY STRONG PRESSURE GRADIENT ACROSS THE AREA...COLD TEMPERATURES AND STRONG WINDS WILL BE THE FORECAST PROBLEM OF THE DAY. EXPECT WINDS TO REMAIN SUSTAINED OUT OF THE NORTH OR NORTHWEST AT 10-15 KTS WITH GUSTS OF 25-30 KTS FOR MUCH OF THE DAYLIGHT HOURS. AFTER SUNSET GUSTS WILL SUBSIDE. HIGH TEMPERATURES ONLY IN THE LOW TO MID 30S AND WITH WIND CHILL VALUES IN THE UPPER 10S TO LOW 20S FOR MUCH OF THE DAY. AS AN ASIDE...WITH THE COLD BUT ALSO DRY AIRMASS IN PLACE...MIN RH VALUES WILL DIP DOWN INTO THE LOW 20S. COMBINE THESE VALUES WITH THE HIGHER WINDS AND THERE WILL BE A SMALL INCREASE IN FIRE DANGER SATURDAY IN OUR SOUTHERN COUNTIES THAT MAY SQUEAK INTO THE LOWER 40S. SATURDAY NIGHT WILL SEE THE GUSTS SLACK OFF BUT SUSTAINED WINDS TO REMAIN UP IN THE 5 TO 10 KT RANGE KEEP THINGS MIXED A LITTLE. COMBINE THIS WITH VERY COLD EXPECTED LOW TEMPERATURES IN THE LOW TO MID TEENS...WIND CHILL VALUES SATURDAY NIGHT WILL RESIDE IN THE 5-10 DEGREE RANGE. PREPARATIONS SHOULD BE MADE NOW TO PROTECT ANYTHING SUSCEPTIBLE TO THE COLD WIND CHILLS...ESPECIALLY PETS. SOME CLOUDS WILL BEGIN TO APPROACH THE AREA LATE SATURDAY NIGHT INTO SUNDAY MORNING FROM THE WEST IN ADVANCE OF THE NEXT STORM SYSTEM. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 315 PM FRIDAY... ...STORM SYSTEM LIKELY TO BRING WINTRY WEATHER THREAT SUN NIGHT/MON FOLLOWED BY HEAVY RAIN THREAT AND A FEW STORMS MON NIGHT/TUE... SUNDAY: CONTINUED CHILLY WITH THE ARCTIC HIGH PRESSURE EXTENDING FROM THE ERN GREAT LAKES DOWN THROUGH NC. WILL HAVE INCREASING CLOUDS AHEAD OF THE APPROACHING STORM... AS OUR MID LEVEL FLOW SHIFTS FROM FAST NORTHWESTERLY TO WEST-SOUTHWEST... A FUNCTION OF PACIFIC NORTHWEST ENERGY DIVING INTO AN INITIALLY FLAT/BROAD CENTRAL CONUS TROUGH CAUSING ITS AMPLIFICATION. STATISTICAL GUIDANCE STILL SUPPORTS HIGHS FROM 29 NE TO 35 SW. -GIH SUN NIGHT THROUGH TUE: OVERVIEW: CONFIDENCE IS BEGINNING TO INCREASE REGARDING THE TIMING... MOST PROBABLE PRECIP TYPE PATTERN... AND PRIMARY WEATHER THREATS FOR THE INCOMING SYSTEM. LATEST GUIDANCE SHOWS A BIT QUICKER ONSET... WITH PRECIP ARRIVING IN THE NRN/WRN CWA SUN NIGHT... AS WELL AS A SLIGHTLY EARLIER DEPARTURE ON TUE. LONGWAVE TROUGHING WILL CONTINUE TO AMPLIFY ALONG THE MISS VALLEY AS NRN STREAM ENERGY DROPS INTO ITS BASE OVER THE GULF STATES... CULMINATING IN A NARROW DEEP SHORTWAVE TROUGH TAKING ON A POSITIVE TILT AS IT SWINGS ENE INTO THE CAROLINAS. AT THE SURFACE... THE POLAR HIGH SITUATED OVER THE NORTHEAST AND MIDATLANTIC STATES SUN NIGHT CONTINUES TO PUSH STEADILY NORTHEAST AND OFFSHORE THROUGH MON... WHILE A COASTAL FRONT FORMS ALONG THE CAROLINA COAST EXTENDING BACK TO DEVELOPING LOW PRESSURE OVER THE CENTRAL GULF STATES. THIS LOW THEN TRACKS EAST THEN NE THROUGH WRN NC MON NIGHT/TUE MORNING BEFORE MOVING QUICKLY INTO THE NORTHEAST STATES... WITH A TRAILING FRONT SWEEPING THROUGH CENTRAL/ERN NC BY EARLY TUE AFTERNOON. PRECIPITATION CHANCES: THE INITIAL PROCESSES TO FORCE ASCENT SUNDAY NIGHT INTO EARLY MONDAY INCLUDING DPVA AND MOIST ISENTROPIC UPGLIDE ARE RATHER WEAK AND FOCUSED PRIMARILY ON WRN AND NRN PORTIONS OF CENTRAL NC. WILL TREND POPS UP TO LIKELY NW AND RETAIN HIGH CHANCES ACROSS THE SOUTH AND EAST SUN NIGHT INTO MON MORNING... WITH QPF FAIRLY LIGHT... UNDER A QUARTER INCH MAINLY IN THE NW. BUT THIS CHANGES QUICKLY WITH THE ADDITION OF STRONG UPPER DIVERGENCE (DUE TO IDEALLY JUXTAPOSED POLAR AND SUBTROPICAL JETS) AND VIGOROUS LOW LEVEL MOISTURE TRANSPORT EAST OF THE LOW. WILL RAMP UP POPS FURTHER TO CATEGORICAL WEST/LIKELY EAST LATE MON... THEN TO CATEGORICAL EVERYWHERE MON NIGHT THROUGH TUE MORNING... ENDING SW TO NE TUE AFTERNOON. PTYPES: USING THE TOP-DOWN METHODOLOGY WITH CONSIDERATION OF THE INITIALLY VERY COLD/DENSE NATURE OF THE SURFACE AIR MASS... THE INITIAL COLD AIR ALOFT GIVING WAY TO A WARM NOSE... AND THE STRONG LOW LEVEL WARM ADVECTION APT TO DISLODGE THIS SURFACE AIR MASS GRADUALLY FROM SE TO NW MON EVENING... EXPECT THIS TO START AS MOSTLY LIGHT SNOW WITH PERHAPS PATCHY LIGHT SLEET SUN NIGHT ACROSS THE NRN AND WRN CWA... FOLLOWED BY A SLOW STEADY TRANSITION FROM SSE TO NNW TO FREEZING RAIN/SLEET THEN TO ALL RAIN... WITH THE FAR NW COUNTIES INCLUDING THE TRIAD THE LAST TO SEE AN END TO THE WINTRY PRECIP MON EVENING. TENTATIVE ACCUMULATIONS ARE UP TO ONE TO TWO HUNDREDTHS OF AN INCH OF ICING (TRACE AMOUNTS) FOR MUCH OF THE CWA... AND SNOW TOTALS OF 1-3" NW QUARTER WITH AN INCH OR LESS ELSEWHERE... ALL OF WHICH SHOULD BE QUICKLY SWEPT AWAY BY MODERATE TO POTENTIALLY HEAVY RAINFALL LATE MON NIGHT INTO TUE MORNING. RAINFALL TOTALS AND STORM POTENTIAL: AT THIS TIME STORM TOTAL LIQUID QPF IS EXPECTED TO BE 1-2" WITH LOCALLY HIGHER AMOUNTS POSSIBLE... GIVEN THE HIGH WATER CONTENT AND STRONG LIFT MON NIGHT/TUE MORNING. BASED ON THE ANTECEDENT CONDITIONS AND SEVERAL RIVERS AND CREEKS RUNNING HIGH... A FLOOD WATCH MAY BE NEEDED FOR SOME PORTION OF THE AREA. ALSO... WHILE LAPSE RATES ARE UNLIKELY TO BE VERY IMPRESSIVE... THE STRONG AND FOCUSED LIFT POSSIBLE WITH THIS SYSTEM AND WARMING LOW LEVELS ESPECIALLY IN THE SANDHILLS AND COASTAL PLAIN MAY SUPPORT A FEW LIGHTNING STRIKES ON TUE. TEMPS: EXPECT LOWS SUN NIGHT OF 22-26. TEMPS SHOULD SLOWLY RISE MON THROUGH MON NIGHT... REACHING THE LOW 30S NW TO LOW 40S SE LATE MON... RISING TO THE MID 30S NW TO MID 40S SE MON NIGHT... AND PEAKING AT 48-56 TUE PRIOR TO FRONTAL PASSAGE. WED THROUGH FRI: WE MAY SEE A PERTURBATION SWING THROUGH THE LONGWAVE ERN TROUGH BASE ACROSS VA ON WED... BUT MODELS VARY ON THE STRENGTH AND LATITUDE OF ANY SUCH WAVE... AND REGARDLESS THE MOISTURE WILL BE LIMITED YIELDING NO IMPACTS ON CENTRAL NC OTHER THAN SOME CLOUDS ACROSS THE NORTH. OTHERWISE... THIS PERIOD WILL FEATURE A TRANSITION AWAY FROM WRN RIDGE/ERN TROUGH OVER THE CONUS... AS FLAT RIDGING BUILDS OVER THE GULF/SOUTHEAST STATES FROM THE WEST... WITH A NET RESULT OF DRY WEATHER AND NEAR TO SLIGHTLY ABOVE NORMAL TEMPS FOR CENTRAL NC. -GIH && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... AS OF 730 PM FRIDAY... 24 HOUR TAF PERIOD: ASIDE FROM LINGERING IFR/MVFR CEILINGS THROUGH 01- 02Z AT THE FAY TERMINAL...VFR CONDITIONS WILL PREVAIL AT ALL TERMINALS FOR THE DURATION OF THE TAF PERIOD. THE ONLY AVIATION CONCERN WILL BE GUSTY NORTHWEST WINDS DURING THE DAY SATURDAY (ESP MORNING)...IN THE WAKE OF AN ARCTIC COLD FRONTAL PASSAGE LATE TONIGHT. EXPECT WINDS TO INCREASE TO ~15 KT WITH GUSTS UP TO 25 KT DURING THE STRONGEST COLD ADVECTION (09-15Z)...REMAINING STEADY AT 12-16 KT FOR THE REMAINDER OF THE DAY. WINDS WILL DECREASE TO 5-10 KT AFTER SUNSET SAT EVENING. LOOKING AHEAD: VFR CONDITIONS WILL PREVAIL THROUGH MID-DAY SUNDAY AS AN ARCTIC AIRMASS ADVECTS INTO/OVER THE REGION. HIGH PRESSURE WILL QUICKLY MOVE OFFSHORE...WITH MVFR CEILINGS RETURNING FROM WEST-EAST SUNDAY EVENING/NIGHT IN ASSOC/W A STRENGTHENING SOUTHERLY RETURN FLOW. CONFIDENCE IN THE FORECAST DECREASES SIGNIFICANTLY EARLY NEXT WEEK...HOWEVER...ADVERSE CONDITIONS IN THE FORM OF LOW CEILINGS AND PRECIPITATION (PERHAPS MIXED PTYPE) WILL BE POSSIBLE. -VINCENT && .CLIMATE... HERE ARE THE RECORD LOWS AND RECORD LOW MAXIMUM TEMPERATURES FOR SAT FEB 13TH AND SUN FEB 14TH AT GSO... RDU... AND FAY: REC YR REC YR LOW LOW MAX ---------------------------------------------- GSO: 02/13 11 1955 31 1986 02/14 6 1905 22 1914 RDU: 02/13 4 1899 10 1899 02/14 -2 1899 27 1916 FAY: 02/13 14 1973 32 1955 02/14 12 1968 33 1916 && .RAH WATCHES/WARNINGS/ADVISORIES... NONE && $$ SYNOPSIS...HARTFIELD NEAR TERM...SMITH SHORT TERM...ELLIS LONG TERM...HARTFIELD AVIATION...VINCENT CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1145 PM CST WED FEB 10 2016 .UPDATE... ISSUED AT 1145 PM CST WED FEB 10 2016 REGIONAL RADAR SHOWS REFLECTIVITYS INCREASING ACROSS SOUTHWEST SASKATCHEWAN AND INTO EASTERN MONTANA. SOME ENHANCEMENT ALSO SHOWING UP IN NORTHWEST NORTH DAKOTA. 00Z MODEL GUIDANCE IN GOOD AGREEMENT WITH LIGHT SNOW DEVELOPING NORTHWEST TO SOUTHEAST OVERNIGHT. THUS LIGHT SNOW WILL BE INTO WILLISTON WITHIN THE NEXT HOUR OR TWO...AND THEN INTO BISMARCK AROUND 6AM CST THURSDAY. THE LEFT EXIT REGION OF A JET STREAK PROPAGATING ACROSS CENTRAL MONTANA WILL PROVIDE LARGE SCALE ASCENT UNTIL MID AFTERNOON THURSDAY. THUS LIKELY TO CATEGORICAL POPS WEST AND SOUTH CENTRAL LATE TONIGHT INTO THURSDAY. NAM/RAP/HRRR BUFKIT SOUNDINGS ALL POINT TO A QUICK SATURATION THROUGH THE COLUMN OVERNIGHT. THUS RISK OF PATCHY LIGHT FREEZING DRIZZLE WILL WANE FROM WEST TO EAST THROUGH 12Z THURSDAY. UPDATE ISSUED AT 932 PM CST WED FEB 10 2016 MAIN UPDATE LATE THIS EVENING WAS TO ADD A MENTION OF PATCHY FREEZING DRIZZLE BACK TO THE FORECAST THIS EVENING. LOWER LAYERS HAVE BEEN MOISTENING UP ACROSS THE NORTHWEST INTO THE WEST CENTRAL. ALSO RECEIVED A REPORT OF LIGHT FREEZING DRIZZLE AT GRASSY BUTTE. LATEST RAP BUFKIT SOUNDINGS DO SUPPORT A PERIOD OF DRIZZLE MAINLY BEFORE MIDNIGHT ACROSS THIS AREA...BEFORE THE ENTIRE COLUMN MOISTENS. THUS ADDED A MENTION BACK TO THE NORTHWEST THROUGH 06Z AND THEN SHIFTED IT INTO THE SOUTHWEST THROUGH 09Z. TEMPERATURES LOOK REASONABLE. ROLLA IN THE FAR NORTH CENTRAL HAS DROPPED TO ZERO IN A SMALL CLEAR PATCH AND COULD DROP A FEW MORE DEGREES. TREND THOUGH IS FOR STEADY OR SLOWLY RISING TEMPERATURES AS CLOUDS INCREASE FROM THE WEST. UPDATE ISSUED AT 637 PM CST WED FEB 10 2016 SURFACE LOW PRESSURE THAT MOVED THROUGH THE AREA LAST NIGHT INTO TODAY HAS MOVED WELL SOUTH. HIGH PRESSURE CONTINUES TO DROP SOUTH FROM MANITOBA INTO EASTERN NORTH DAKOTA AND MINNESOTA...WHILE A LEE SIDE TROUGH IS TAKING SHAPE OVER THE NORTHERN AND CANADIAN ROCKIES. THE SURFACE TROUGH WILL MOVE INTO EASTERN MONTANA TONIGHT AND COMBINED WITH SHORTWAVE ENERGY ALONG THE BAROCLINIC ZONE WILL PRODUCE LIGHT SNOW WHICH IS EXPECTED TO SPREAD INTO WESTERN NORTH DAKOTA AFTER MIDNIGHT. UNTIL THEN...T/TD SPREAD REMAIN PRETTY HIGH ACROSS THE WEST WITH WIDESPREAD STRATUS OVER ALL BUT THE FAR SOUTHWEST CORNER OF THE STATE. THUS THINK THE RISK OF FREEZING DRIZZLE THIS EVENING IS MINIMAL. AS WE HEAD INTO THE OVERNIGHT HOURS...MOISTURE INCREASES THROUGHOUT THE ATMOSPHERIC COLUMN AND DRY LAYERS ALOFT...CONDUCIVE TO DRIZZLE QUICKLY MOISTEN UP. THUS HAVE ALSO REMOVED THE MENTION OF DRIZZLE AFTER MIDNIGHT. WILL KEEP A MENTION OF FOG AS SURFACE MOISTURE WILL INCREASE AS WE MOVE INTO THE OVERNIGHT HOURS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 254 PM CST WED FEB 10 2016 CURRENT SURFACE ANALYSIS PLACES LOW/BOUNDARY STRETCHING THROUGH WESTERN NORTH DAKOTA INTO CENTRAL SOUTH DAKOTA/NEBRASKA WHILE HIGH REMAINS OVER THE GREAT BASIN. UPPER LEVEL ANALYSIS PLACES BROAD RIDGE OVER THE WESTERN CONUS WITH BROAD TROUGH OVER THE EASTERN CONUS BRINGING FAST NORTHWESTERLY FLOW OVER OUR AREA. SOME LIGHT SNOW LINGERS OVER EASTERN PORTIONS OF THE AREA AS RIGHT ENTRANCE REGION OF AN UPPER JET STREAK WORKS ITS WAY OFF TO THE SOUTHEAST. FOR THE REST OF THIS AFTERNOON INTO TONIGHT...SOME LIGHT SNOW MAY LINGER OVER THE EASTERN PART OF THE AREA THROUGH THE AFTERNOON AS THE AFOREMENTIONED JET CONTINUES ON ITS WAY. CLOUDY CONDITIONS WILL REMAIN OVER THE AREA...WHILE OVER THE SOUTHWEST LATEST FORECAST SOUNDINGS SUGGEST SOME FOG WITH PATCHY FREEZING DRIZZLE MAY DEVELOP. LATER TONIGHT BROAD SHORT WAVE MOVES INTO THE REGION RESULTING IN AN ELONGATED AREA OF MODEST LIFT OVER WESTERN PARTS OF NORTH DAKOTA. THEREFORE...EXPECT SOME LIGHT SNOW TO DEVELOP AND GRADUALLY SPREAD SOUTHERLY. FOR THURSDAY...BROAD AREA OF MODEST LIFT SPREADS EASTERLY INTO CENTRAL PARTS OF NORTH DAKOTA WITH THE GREATEST CHANCES FOR SNOW SPREADING FROM WEST CENTRAL TO SOUTH CENTRAL PORTIONS OF THE STATE WHERE A BROAD SWATH OF 1 TO 3 INCHES MAY FALL. OVER THE FAR SOUTHWEST...WARMER CONDITIONS MAY LEAD TO PERIODS OF RAIN DEVELOPING BY MID-DAY INTO THE AFTERNOON. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 254 PM CST WED FEB 10 2016 AN ACTIVE WEATHER PATTERN CONTINUES THROUGH THE LONG TERM. NORTHWEST FLOW WILL CONTINUE INTO THE WEEKEND. THIS WILL BRING SEVERAL WAVES ACROSS THE REGION. THE FIRST WAVE IS EXPECTED TO ARRIVE THURSDAY. AS THE BAROCLINIC ZONE SHIFTS WEST...SNOW WILL LIKELY OVERSPREAD WESTERN AND SOUTH CENTRAL NORTH DAKOTA. HOWEVER...ONLY MINOR ACCUMULATIONS ARE EXPECTED...GENERALLY AROUND ONE INCH. THE NEXT WAVE IS EXPECTED TO IMPACT NORTH DAKOTA BEGINNING FRIDAY NIGHT AND PERSIST THROUGH SUNDAY MORNING. THIS WAVE IS EXPECTED TO BRING A LITTLE MORE MOISTURE TO THE REGION THAN PREVIOUS SYSTEMS AS THIS WAVE WILL HAVE MORE OF A PACIFIC COMPONENT TO IT. WHILE FORCING DOES NOT APPEAR TOO STRONG WITH THIS WAVE...PERSISTENT LIGHT SNOW WITH BROAD SCALE LIFT OVER A 36 HOUR PERIOD COULD BRING SNOWFALL AMOUNTS INTO THE 2 TO 4 INCH RANGE. MODELS ARE JUST BEGINNING TO COME INTO BETTER AGREEMENT ON THE EVOLUTION OF THIS SYSTEM...SO DETAILS WILL BE FURTHER REFINED OVER THE NEXT COUPLE OF DAYS AND AMOUNTS/PRECIP TYPE COULD CHANGE QUITE A BIT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1145 PM CST WED FEB 10 2016 LIGHT SNOW AND FOG WILL RESULT IN CIGS/VSBYS TO DETERIORATE INTO THE IFR/LIFR RANGE AT KISN/KDIK/KBIS 06Z-12Z THURSDAY AND CONTINUE UNTIL AROUND 00Z FRIDAY. KMOT AND KJMS WILL REMAIN ON THE EASTERN FRINGE OF THE LIGHT SNOW/PRECIPITATION SHIELD...THUS VSBYS WILL REMAIN IN THE MVFR TO VFR CATEGORY...WHILE CIGS WILL BE IN THE MVFR RANGE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KS SHORT TERM...JJS LONG TERM...AJ AVIATION...KS
AREA FORECAST DISCUSSION
NWS MEDFORD OR
241 PM PST THU FEB 11 2016 .DISCUSSION...SKIES ARE THINNING OUT IN THE WAKE OF THE WEAK SHORTWAVE THAT MOVED THROUGH THE AREA THIS MORNING. THIS IS IN RESPONSE TO AN UPPER RIDGE BUILDING AHEAD OF A DEEPENING TROUGH NEAR 35N/140W. THIS SHOULD SLOW DOWN THE EASTWARD PROGRESSION OF THE FRONT LATE TONIGHT. CURRENT HRRR MODEL SUGGEST THIS AND IS IN LINE WITH THE NAM AND GFS. THEREFORE HAVE ADJUSTED POPS DOWN FOR THIS EVENING AND TONIGHT, KEEPING THE BEST CHANCE FOR ANY RAIN OVER THE MARINE WATERS AND ALONG THE COAST, NORTH OF CAPE BLANCO. I DON`T THINK RAINFALL WILL MAKE MUCH IF ANY PROGRESS INLAND TONIGHT, BUT STILL KEPT IN A SLIGHT CHANCE TO CHANCE ALONG THE SOUTH COAST AND IN PORTIONS OF COOS AND NORTHWEST DOUGLAS COUNTY. SKIES SHOULD REMAIN MOSTLY CLEAR THROUGH THIS EVENING BEFORE INCREASING AHEAD OF THE COLD FRONT TONIGHT. THE COLD FRONT WILL REACH THE COAST FRIDAY MORNING, THEN MOVING ONSHORE DURING THE DAY FRIDAY. THIS WILL BRING THE BEST CHANCE FOR MEASURABLE RAIN WITH MOST OF THE RAIN CENTERED ALONG THE COASTAL MOUNTAINS AND CASCADES. EVEN THEN, QPF AMOUNTS ARE NOT EXPECTED TO BE SIGNIFICANT AND MODELS HAVE BEEN TRENDING LOWER WITH QPF AMOUNTS. SNOW LEVELS WILL LOWER ON FRIDAY, BUT WILL REMAIN ABOVE ALL THE PASSES THROUGH FRIDAY. A MOIST WESTERLY FLOW WILL SET UP FRIDAY NIGHT WITH A WEAK SHORT WAVE MOVING THROUGH. MOST SHOWERS ARE EXPECTED TO REMAIN ALONG AND WEST OF THE CASCADES, BUT THEY ARE EXPECTED TO BE LIGHT WITH SNOW LEVELS BETWEEN 4500 AND 5000 FEET. THEREFORE WERE NOT EXPECTING MUCH, IF ANY IMPACT ON ANY OF THE ROADS IN THE CASCADES. 500 MB HEIGHTS INCREASE SOME AS WEAK RIDGING BUILDS INTO THE AREA SATURDAY. CONDITIONS SHOULD BE DRY DURING THE DAY, THEN A WARM FRONT WILL ARRIVE SATURDAY NIGHT BRINGING STEADY LIGHT TO MODERATE PRECIPITATION. THE BEST CHANCE FOR HEAVIER PRECIPITATION WILL BE IN THE NORTHERN PART OF THE AREA SATURDAY EVENING, THEN THE FOCUS WILL SHIFT SOUTH SATURDAY NIGHT THROUGH SUNDAY. SNOW LEVELS SATURDAY NIGHT WILL INCREASE AND LIKELY BE ABOVE ALL THE PASSES THROUGH SUNDAY. THE UPPER RIDGE WILL BUILD BACK INTO THE AREA SUNDAY NIGHT WITH RAIN DECREASING, THEN ENDING FROM SOUTH TO NORTH. -PETRUCELLI .LONG TERM DISCUSSION...MONDAY THROUGH THURSDAY. MODELS AND THE ENSEMBLE PLOTS START IN REMARKABLY GOOD AGREEMENT MONDAY WITH AN UPPER LEVEL RIDGE OVER THE WEST COAST SHUNTING SYSTEMS JUST TO THE NORTH OF THE FORECAST AREA. IT IS NOT UNTIL WEDNESDAY MORNING THAT THE MODEL PLOTS SHOW ANY SIGNIFICANT DIVERGENCE...BUT THE MAIN DIFFERENCES ARE WITH TIMING OF THE SHIFTING OF THE UPPER LEVEL RIDGE TO THE EAST. THE GFS IS SLIGHTLY FASTER ON WEDNESDAY BRINGING PRECIPITATION ONTO THE COAST WEDNESDAY MORNING, WITH THE ECMWF BRINGING IT IN IN THE AFTERNOON. FROM THERE THE OVERALL PATTERN OF AN UPPER LEVEL TROUGH OVER THE WEST COAST REMAINS FOR ALL OF THE PLOTS...BUT THAT IS THE ONLY AGREEMENT WITH PLOTS ALL OVER THE PLACE WITH DEPTH AND PLACEMENT OF THESE UPPER TROUGHS. WITH THIS IN MIND HAVE GONE WITH THE ENSEMBLE MEAN POPS FOR THE REMAINDER OF THE EXTENDED FORECAST. -SVEN && .AVIATION...FOR THE 12/00Z TAF CYCLE... VFR CONDITIONS WILL PREVAIL INTO TONIGHT. AREAS OF MVFR CIGS/VSBYS IN LIGHT RAIN WILL DEVELOP ALONG THE COAST LATE TONIGHT AND SPREAD INLAND TO THE CASCADES DURING THE DAY FRIDAY WITH AREAS OF HIGHER TERRAIN BECOMING OBSCURED. -JRS && .MARINE...UPDATED 200 PM PST THU FEB 11 2016...MIXED WEST SWELL AT 19 TO 20 SECONDS AND SOUTHWEST SWELL AT 10 TO 11 SECONDS WILL BECOME WESTERLY AT 17 TO 18 SECONDS TONIGHT...THEN REMAIN WESTERLY WITH A GRADUALLY DIMINISHING PERIOD THROUGH SUNDAY. COMBINED SEAS WILL BUILD TO 13 TO 14 FEET THROUGH FRIDAY MORNING...SUBSIDE TO 12 FEET FRIDAY AFTERNOON THROUGH SATURDAY...REBUILD TO 12 TO 13 FEET SATURDAY NIGHT...THEN SUBSIDE BELOW 10 FEET SUNDAY AFTERNOON. A WEAK COLD FRONT WILL MOVE ONSHORE FRIDAY MORNING...AND THIS WILL BRING SMALL CRAFT WINDS TO THE NORTHERN OUTER WATERS TONIGHT. OFFSHORE HIGH PRESSURE WILL BUILD FRIDAY...THEN WEAKEN SATURDAY. A SLIGHTLY STRONGER COLD FRONT WILL MOVE ONSHORE SATURDAY NIGHT. OFFSHORE HIGH PRESSURE WILL REBUILD SUNDAY...THEN WEAKEN TUESDAY AS A STRONGER FRONT APPROACHES THE AREA. -JRS && .MFR WATCHES/WARNINGS/ADVISORIES... OR... CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY FOR PZZ350-356-370-376. SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 4 AM PST FRIDAY FOR PZZ370. $$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
902 AM PST THU FEB 11 2016 .DISCUSSION...THE WEAK SHORTWAVE THAT BROUGHT ISOLATED LIGHT SHOWERS IS MOVING NORTHEAST AND SHOULD BE OUT OF THE FORECAST AREA IN THE NEXT COUPLE OF HOURS TAKING ALL THE SHOWERS WITH IT. IN IT`S WAKE SOME CLEARING IS DEVELOPING IN NORTHERN CAL AND SOUTHWEST OREGON AND SOME OF THIS COULD MAKE IT INTO OUR AREA LATE THIS MORNING INTO THIS AFTERNOON. THE LATEST HRRR MODEL SUGGEST MOST HOURS AND LOCATIONS WILL BE DRY THIS AFTERNOON. THE GFS AND NAM ALSO SHOW SIMILAR SOLUTIONS. THEREFORE, POPS WILL BE LOWERED FOR THIS AFTERNOON. DRY CONDITIONS ARE EXPECTED FOR MOST OF TONIGHT, THEN A COLD FRONT WILL REACH THE COAST EARLY FRIDAY MORNING, THEN MOVE ONSHORE DURING THE DAY FRIDAY. -PETRUCELLI && .AVIATION...FOR THE 11/12Z TAF CYCLE... VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS THE VALLEYS AND PRIMARY AIRFIELDS THROUGH THE TAF PERIOD. A WARM FRONT MOVING THROUGH THIS MORNING INTO EARLY AFTERNOON WILL RESULT IN SOME LIGHT SHOWER ACTIVITY. EXPECT SOME PARTIAL TERRAIN OBSCURATIONS THIS MORNING INTO THE EARLY AFTERNOON MAINLY FROM THE CASCADES WESTWARD, AND GREATEST OVER THE COAST RANGE. A BRIEF PERIOD OF MVFR IS POSSIBLE ALONG THE COAST LATE THIS MORNING THROUGH EARLY AFTERNOON. BTL && .MARINE...UPDATED 305 AM PST THU FEB 11 2016...LONG PERIOD WEST SWELL WILL BUILD TODAY THROUGH FRIDAY AND THEN PERSIST THROUGH SATURDAY. A WARM FRONT WILL MOVE THROUGH TODAY FOLLOWED BY INCREASING SOUTH WINDS AHEAD OF A COLD FRONT TONIGHT. THIS COLD FRONT WILL MOVE THROUGH LATE TONIGHT THROUGH FRIDAY MORNING. AFTER A BREAK ON FRIDAY AND MOST OF SATURDAY ANOTHER FRONT WILL MOVE THROUGH SATURDAY NIGHT INTO SUNDAY. HIGH PRESSURE IS THEN LIKELY TO REBUILD ALONG THE WEST COAST EARLY NEXT WEEK BEFORE A STRONGER FRONT ARRIVES WEDNESDAY THROUGH THURSDAY. BTL && .PREV DISCUSSION... /ISSUED 354 AM PST THU FEB 11 2016/ SHORT TERM...A SHORTWAVE RIDING UP THROUGH THE SOUTHWEST FLOW ALOFT HAS KICKED OFF A FEW SHOWERS OVER OUR AREA THIS MORNING. NO RAIN HAS HIT ANY OF THE OBSERVING SITES YET, BUT RADAR SHOWS ISOLATED SHOWERS DRIFTING THROUGH RIGHT NOW. SHOWER COVERAGE WILL INCREASE THIS MORNING AS THE MAIN PART OF THE SHORTWAVE ARRIVES, AND RADAR IS SHOWING A LOT MORE SHOWERS OFF THE NW CALIFORNIA COAST MOVING OUR WAY. MODELS SHOW THESE SHOWERS BEING CONFINED MOSTLY TO THE CASCADE CREST AND WEST SIDE, BUT SOME SHOWERS CERTAINLY COULD DRIFT OVER ONTO THE EAST SIDE. POPS HAVE BEEN RAISED THIS MORNING. WE WILL PROBABLY SEE AT LEAST SOME LINGERING SHOWERS THIS AFTERNOON AND EVENING AS A WEAK COLD FRONT APPROACHES. THIS COLD FRONT WILL MOVE ONSHORE TONIGHT AND FRIDAY MORNING AND BRING LIGHT RAIN TO MOST WEST SIDE LOCATIONS AS IT MOVES INLAND FRIDAY. WE`RE NOT EXPECTING A LOT OF RAIN WITH VALLEY LOCATIONS PROBABLY ONLY SEEING A FEW HUNDREDTHS OF RAIN. HOWEVER, MOUNTAIN LOCATIONS COULD SEE UP TO A QUARTER OF AN INCH OF RAIN. SNOW LEVELS WILL BE HIGH (ABOVE 8000 FEET MOST OF THE DAY), SO IT WILL BE RAIN EXCEPT AT THE HIGHEST PEAKS. SNOW MAY MAKE IT DOWN TO CRATER LAKE AND MT ASHLAND BY DAY`S END, BUT MOST OF THE PRECIPITATION WILL HAVE ALREADY FALLEN BY THEN. POPS WERE RAISED TO AT LEAST LIKELY ON THE WEST SIDE FOR FRIDAY. SATURDAY SHOULD BE A BIT OF A BREAK WITH LEFTOVER MORNING SHOWERS OVER THE NORTH DECREASING THROUGH THE DAY. ELSEWHERE, THE DAY OUGHT TO BE DRY. THE PREVIOUS SHIFT`S THINKING REGARDING SUNDAY`S SYSTEM STILL LOOKS REASONABLE AND THE PREVIOUS LONG TERM DISCUSSION FOLLOWS. THE ONE CHANGE MADE TO THE EXTENDED FORECAST THIS MORNING WAS TO RAISE POPS ON SUNDAY. -WRIGHT LONG TERM...SUNDAY THROUGH WEDNESDAY...A WARM FRONT WITH GOOD ISENTROPIC ASCENT WILL RIDE OVER THE TOP OF A FLAT RIDGE ON SUNDAY. THIS COMBINED WITH DEEP ONSHORE WEST-NORTHWEST FLOW WILL RESULT IN RAIN, FOCUSED ON NORTH AND WEST FACING TERRAIN ALONG AND WEST OF THE CASCADES WITH LIGHTER RAIN IN THE VALLEYS. RAIN CHANCES DIMINISH SOUTH AND EAST OF THE MOUNTAINS. SNOW LEVELS WILL BE WELL ABOVE THE MAJOR PASSES AND LIKELY ABOVE 8000 FEET IN MOST AREAS. THE WARM FRONT WILL SHIFT NORTHWARD IN THE AFTERNOON AND ISENTROPIC LIFT WILL EASE...EFFECTIVELY SHUTTING OFF RAINFALL FROM SOUTH TO NORTH ACROSS THE CWA LATE SUNDAY AFTERNOON AND NIGHT. MODELS INDICATE THE RIDGE WILL STRENGTHEN A BIT OVER THE AREA MONDAY WITH MOST, IF NOT ALL PRECIPITATION REMAINING TO THE NORTH OF THE CWA. MODELS DIFFER A BIT WITH RESPECT TO ANOTHER SHORTWAVE RIDING OVER THE RIDGE MONDAY NIGHT INTO TUESDAY. THE GFS KEEPS IT WAY TO THE NORTH WHERE IT WOULD HAVE NO IMPACT ON OUR WEATHER. THE ECMWF THOUGH HAS IT FARTHER SOUTH. DUE TO THE UNCERTAINTY, WE HAVE INDICATED SLIGHT CHANCE TO CHANCE POPS FROM THE COAST TO THE CASCADES AND NORTH OF THE UMPQUA DIVIDE. IT SHOULD STAY DRY IN THE ROGUE VALLEY. CONFIDENCE IS FAIRLY HIGH THAT THE NEXT SIGNIFICANT UPPER TROUGH TO IMPACT THE AREA WILL ARRIVE TUESDAY NIGHT INTO WEDNESDAY. THE SURFACE COLD FRONT WILL BE JUST OFFSHORE LATE TUESDAY NIGHT, THEN MOVE ACROSS THE AREA WEDNESDAY INTO WEDNESDAY NIGHT. RAIN IS LIKELY FROM THE COAST TO THE CASCADES WITH HIGH CHANCES EVEN OVER THE EAST SIDE. SNOW LEVELS START OUT HIGH AHEAD OF THE FRONT, BUT COULD DROP DOWN TO 3000 FEET BEHIND THE FRONT BY THURSDAY MORNING. -SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR... CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY FOR PZZ350-356-370-376. SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 4 AM PST FRIDAY FOR PZZ350-370. $$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
434 PM EST THU FEB 11 2016 .SYNOPSIS... A PERSISTENT NORTHWEST WIND WILL KEEP LAKE EFFECT AND UPSLOPE SNOW SHOWERS GOING THE REST OF THIS AFTERNOON. AN ARCTIC BLAST WILL DELIVER THE COLDEST AIR OF THE SEASON FOR VALENTINES WEEKEND. THE ARCTIC FRONTAL BOUNDARY WILL BE ACCOMPANIED BY A ROUND OF BLINDING SNOW SQUALLS LATE FRIDAY AND FRIDAY NIGHT...FOLLOWED BY DANGEROUS COLD AND VERY LOW WIND CHILLS THAT ARE EXPECTED TO IMPACT THE AREA SATURDAY INTO SUNDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... NUMEROUS...NARROW BANDS OF SNOW SHOWERS AND BRIEF SQUALLS CONTINUE TO STREAM SE AND WELL INLAND FROM THE GLAKES THIS AFTERNOON...MAKING IT ALL THE WAY INTO PORTIONS OF THE LOWER SUSQ VALLEY REGION /AND IN FACT...RIGHT TO THE MID ATLANTIC SEABOARD/. BRIEF...REDUCED VSBYS TO BETWEEN 1/4-1/2SM WILL IMPACT TRAVEL WITHIN THESE NARROW SNOW BANDS THAT COULD DROP UP TO ONE INCH OF FLUFF IN JUST A 30 MINUTE PERIOD. 18Z HRRR COMBINED WITH A LOOK AT THE LOW-MID LEVEL LAPSE RATES VIA THE NAM INDICATE THAT THE SNOW SHOWERS/BRIEF SQUALLS WILL CONTINUE UNTIL 23 THU-01Z FRIDAY BEFORE QUICKLY DISSIPATING AS THE SUBSIDENCE INVERSION DROPS FROM 7-8 KFT AGL...TO UNDER 4 KFT AGL. WILL MAINTAIN CURRENT WINTER WEATHER ADVISORIES OVER THE LAURELS AND WRN MTNS...AND LES WARNINGS AND ADVISORIES FOR THE FAR NW SNOWBELT WHERE PERSISTENT UPSLOPE AND LES SNOWS ARE EXPECTED TO CONTINUE INTO THIS EVENING. THE WIND WILL MAKE IT FEEL MUCH COLDER LATE TDY WITH WIND CHILLS BETWEEN -10 AND +10 ACROSS THE ENTIRE AREA. THE BLUSTERY CONDITIONS WILL JUST BE A TASTE OF WHAT LOOKS LIKE IS ON THE HORIZON FOR LATER FRIDAY NIGHT RIGHT INTO SUNDAY. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... SFC HIGH PRESSURE WILL SLIDE SOUTH OF THE STATE LATE TONIGHT BRINGING GRADUAL CLEARING. FLURRIES AND SCATTERED SNOW SHOWERS WILL LIFT NORTH EARLY TONIGHT AND BE CONFINED MAINLY TO THE NORTHERN TIER BY AROUND MIDNIGHT. TEMPS DROP INTO THE SINGLE DIGITS TONIGHT AS SOME CLEARING TAKES PLACE IN THE NW...BUT THE CALM AIR IN THE SE COULD CAUSE THE TEMPS THERE TO BECOME COLDER IN A FEW OF THE PERENNIAL COLD RURAL AREAS...SUCH AS SEG AND THV - MAKING THEM 3-5F COLDER THAN THE SURROUNDING LOCALES. THE FIRST PART OF FRIDAY SHOULD BE QUIET WITH PARTLY TO MOSTLY SUNNY SKIES AND RELATIVELY LIGHT WSW WIND. CLOUDS WILL QUICKLY INCREASE FROM THE SW AS SOME MEAGER WARM ADVECTION KICKS IN AHEAD OF THE WELL- ADVERTISED ARCTIC FRONT. SOME LIGHT SNOW/SNOW SHOWERS WILL DEVELOP DURING THE AFTN...BUT ACCUMS SHOULD BE MEAGER /GENERALLY UNDER 1/2 INCH. TEMPS WILL TRY TO GET INTO THE 20S ALL OVER BUT THE PERSISTENT CLOUD COVER IN THE NW WILL LIKELY LIMIT THEM TO THE UPPER TEENS. ARCTIC FRONT AND AN EXPANSIVE AREA OF STEEP 850-700 MB LAPSE RATES GREATER THAN 8C/KM WILL PLOW ACROSS THE STATE LATE FRIDAY IN THE NW...AND AFTER DARK - FRIDAY NIGHT ELSEWHERE. THIS SHOULD BE ONE OF THOSE ONCE IN A YEAR /OR SEVERAL YEAR/ EVENTS COMPLETE WITH DANGEROUS BLINDING SNOW SQUALLS CREATING WIDESPREAD TRAFFIC/TRAVEL PROBLEMS...FROM THE COMBINED EFFECT OF HEAVY FALLING AND BLOWING SNOW - AMOUNTING TO BETWEEN 1-3 INCHES IN A SHORT 30 TO 60 MINUTE PERIOD. THUNDER WAS ALSO MENTIONED IN THE GRIDDED WEATHER FIELDS...ESP ACROSS THE NW HALF OF THE STATE BASED ON THE LATE DAY/EVENING TIMING OF THE ARCTIC FROPA. WIND CHILLS DIP TO UNDER ADVISORY CRITERIA /-15F/ EARLY SAT MORNING ACROSS THE NRN MTNS...AND DROP TO NEAR OR SEVERAL DEG F BELOW ZERO ELSEWHERE BY THEN. && .LONG TERM /SATURDAY THROUGH THURSDAY/... *IMPACT WEATHER HIGHLIGHTS: FRIGID TEMPERATURES AND DANGEROUS WIND CHILLS FOR VALENTINES WEEKEND. POTENTIAL WINTER STORM EARLY NEXT WEEK. POLAR VORTEX DIVING INTO NORTHERN NEW ENGLAND WILL DELIVER THE COLDEST AIR OF THE SEASON WITH ARCTIC BLAST INTO CENTRAL PA SAT- SUN. THE GLOBAL MODELS AND ENSEMBLES KEEP A MEAN TROUGH IN PLACE OVER THE EASTERN US INTO THE MIDDLE OF NEXT WEEK. THE MOST NOTABLE FEATURE DURING THE PERIOD WILL BE A LOW PRESSURE SYSTEM TRACKING UP THE EAST COAST ON TUESDAY. THE LATEST 11/12Z MODEL GUIDANCE HAS TRENDED WEST WITH THE LOW TRACK...BUT THERE IS STILL A DECENT SPREAD. AT THIS TIME PRECIPITATION WITH THIS SYSTEM APPEARS LIKELY MON-TUE BUT THE TRACK WILL ULTIMATELY DETERMINE PRECIPITATION TYPE. NEXT WEEK SHOULD END ON A MILDER NOTE. THE COLDEST AIRMASS OF THE 2015-16 WINTER SEASON REMAINS POISED TO ARRIVE THIS WEEKEND...AS A BLAST OF ARCTIC AIR DELIVERS A SHORT DURATION COLD OUTBREAK TO CENTRAL PENNSYLVANIA. SNOW SQUALLS ARE LIKELY WITH THE ARCTIC FRONTAL PASSAGE FRIDAY NIGHT INTO SATURDAY. MAX/MIN TEMPERATURE DEPARTURES OF -20 TO -25 DEGREES BELOW CLIMO ARE FCST SATURDAY AND SUNDAY. MINIMUM TEMPERATURES SATURDAY NIGHT INTO EARLY SUNDAY MORNING RANGE FROM 0F IN THE LOWER SUSQ. VALLEY TO -10F IN THE NORTHWEST ALLEGHENIES. THE FRIGID TEMPERATURES COMBINED WITH DANGEROUS WIND CHILLS /-10 TO -25 BELOW ZERO/ WILL RESULT IN AN INCREASED RISK FOR FROSTBITE AND HYPOTHERMIA. A WIND CHILL WATCH WAS ISSUED FOR NORTHERN PA WHERE CONFIDENCE IS HIGH IN REACHING -25F WIND CHILLS. WIND CHILL HEADLINES ARE A GOOD BET IN LATER SHIFTS FOR THE REMAINDER OF THE AREA AND PRECAUTIONS SHOULD BE MADE NOW TO PROTECT/PREPARE FOR THE UPCOMING COLD SNAP. A MODERATION (WARMING TREND) IS EXPECTED INTO EARLY NEXT WEEK. THE MODEL SPREAD HAS NARROWED A BIT CONCERNING A POTENTIAL WINTER STORM SYSTEM IMPACTING THE MID ATLC/NORTHEAST NEXT MON-TUE. THE 11/12Z OPERATIONAL EC REMAINS ON THE WWD EDGE OF THE ENVELOPE FOLLOWED BY THE CANADIAN GEM AND GFS/GEFS. THE GFS/GEFS HAVE BOTH TRENDED WWD FROM THE PREVIOUS RUN. CONFIDENCE REMAINS LOW ON PTYPES BUT ALL THE MODELS ARE SIGNALING A SIGNIFICANT QPF EVENT...AND THEREFORE HAVE INCREASED POPS IN THE THE LKLY RANGE FOR DAY 5.5-6 /MON NGT-TUESDAY/. && .AVIATION /22Z THURSDAY THROUGH TUESDAY/... LAKE ENHANCED OROGRAPHIC SNOW WILL RESULT IN MAINLY IFR VSBYS AT KBFD/KJST AND POSSIBLY MVFR AT AOO...THROUGH THE FIRST HALF OF THE EVENING. THESE CONDITIONS WILL GRADUALLY IMPROVE WHEN THE MEAN LLVL WIND BACKS FROM THE NW...TO A MORE WESTERLY DIRECTION AS HIGH PRESSURE SLIDES BY JUST TO OUR SOUTH ACROSS THE MIDDLE OHIO RIVER VALLEY...BY 06Z. THROUGHOUT THE CENTRAL RIDGE...THE VALLEY REGION...AND OVER THE SUSQ VALLEY AIRFIELDS...EXPECT MAINLY VFR CONDITIONS. THE SNOW BANDS COULD POSSIBLY BRING IPT AT UNV TO MFR CIGS THROUGH 03Z...WITH EVEN SOME VERY BRIEF IFR IN THE HEAVIER SNOW SHOWERS AND SQUALLS. A TIGHT PRES GRADIENT WILL BRING GUSTY WINDS UP TO 35KTS FOR THE REST OF THIS AFTERNOON AND EARLY EVENING AS DIURNAL HEATING/MIXING WITHIN THE RATHER DEEP BOUNDARY LAYER ALLOWS STRONGER WINDS ALOFT TO MIX TO GROUND LEVEL. ARRIVAL OF SFC RIDGE SHOULD BRING WIDESPREAD VFR CONDS AND DIMINISHING WIND TO CENTRAL PA THIS EVENING...AND CONTINUING THROUGH AT LEAST THE FIRST HALF OF FRIDAY. OUTLOOK... FRI...PM SHSN/VIS REDUCTIONS LIKELY...ESP W MTNS. PERIODS OF LIFR/VLIFR IN INTENSE SNOW SQUALLS LATE FRIDAY /NW/ AND FRIDAY NIGHT EARLY SAT MORNING CENTRAL AND SE. SAT...WINDY. SHSN/REDUCED VIS POSS W MTNS...MAINLY AM. SUN...NO SIG WX EXPECTED. MON...PM SNOW POSSIBLE. MON NIGHT AND TUE...SNOW LIKELY NW HALF OF PENN...WITH RAIN OR SNOW IN THE SE. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ005. WIND CHILL WATCH FROM LATE FRIDAY NIGHT THROUGH SUNDAY MORNING FOR PAZ004>006-037-041-042. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ004. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ010-017-024-033. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
422 PM EST THU FEB 11 2016 .SYNOPSIS... A PERSISTENT NORTHWEST WIND WILL KEEP LAKE EFFECT AND UPSLOPE SNOW SHOWERS GOING THE REST OF THIS AFTERNOON. AN ARCTIC BLAST WILL DELIVER THE COLDEST AIR OF THE SEASON FOR VALENTINES WEEKEND. THE ARCTIC FRONTAL BOUNDARY WILL BE ACCOMPANIED BY A ROUND OF BLINDING SNOW SQUALLS LATE FRIDAY AND FRIDAY NIGHT...FOLLOWED BY DANGEROUS COLD AND VERY LOW WIND CHILLS THAT ARE EXPECTED TO IMPACT THE AREA SATURDAY INTO SUNDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... NUMEROUS...NARROW BANDS OF SNOW SHOWERS AND BRIEF SQUALLS CONTINUE TO STREAM SE AND WELL INLAND FROM THE GLAKES THIS AFTERNOON...MAKING IT ALL THE WAY INTO PORTIONS OF THE LOWER SUSQ VALLEY REGION /AND IN FACT...RIGHT TO THE MID ATLANTIC SEABOARD/. BRIEF...REDUCED VSBYS TO BETWEEN 1/4-1/2SM WILL IMPACT TRAVEL WITHIN THESE NARROW SNOW BANDS THAT COULD DROP UP TO ONE INCH OF FLUFF IN JUST A 30 MINUTE PERIOD. 18Z HRRR COMBINED WITH A LOOK AT THE LOW-MID LEVEL LAPSE RATES VIA THE NAM INDICATE THAT THE SNOW SHOWERS/BRIEF SQUALLS WILL CONTINUE UNTIL 23 THU-01Z FRIDAY BEFORE QUICKLY DISSIPATING AS THE SUBSIDENCE INVERSION DROPS FROM 7-8 KFT AGL...TO UNDER 4 KFT AGL. WILL MAINTAIN CURRENT WINTER WEATHER ADVISORIES OVER THE LAURELS AND WRN MTNS...AND LES WARNINGS AND ADVISORIES FOR THE FAR NW SNOWBELT WHERE PERSISTENT UPSLOPE AND LES SNOWS ARE EXPECTED TO CONTINUE INTO THIS EVENING. THE WIND WILL MAKE IT FEEL MUCH COLDER LATE TDY WITH WIND CHILLS BETWEEN -10 AND +10 ACROSS THE ENTIRE AREA. THE BLUSTERY CONDITIONS WILL JUST BE A TASTE OF WHAT LOOKS LIKE IS ON THE HORIZON FOR LATER FRIDAY NIGHT RIGHT INTO SUNDAY. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... SFC HIGH PRESSURE WILL SLIDE SOUTH OF THE STATE LATE TONIGHT BRINGING GRADUAL CLEARING. FLURRIES AND SCATTERED SNOW SHOWERS WILL LIFT NORTH EARLY TONIGHT AND BE CONFINED MAINLY TO THE NORTHERN TIER BY AROUND MIDNIGHT. TEMPS DROP INTO THE SINGLE DIGITS TONIGHT AS SOME CLEARING TAKES PLACE IN THE NW...BUT THE CALM AIR IN THE SE COULD CAUSE THE TEMPS THERE TO BECOME COLDER IN A FEW OF THE PERENNIAL COLD RURAL AREAS...SUCH AS SEG AND THV - MAKING THEM 3-5F COLDER THAN THE SURROUNDING LOCALES. THE FIRST PART OF FRIDAY SHOULD BE QUIET WITH PARTLY TO MOSTLY SUNNY SKIES AND RELATIVELY LIGHT WSW WIND. CLOUDS WILL QUICKLY INCREASE FROM THE SW AS SOME MEAGER WARM ADVECTION KICKS IN AHEAD OF THE WELL- ADVERTISED ARCTIC FRONT. SOME LIGHT SNOW/SNOW SHOWERS WILL DEVELOP DURING THE AFTN...BUT ACCUMS SHOULD BE MEAGER /GENERALLY UNDER 1/2 INCH. TEMPS WILL TRY TO GET INTO THE 20S ALL OVER BUT THE PERSISTENT CLOUD COVER IN THE NW WILL LIKELY LIMIT THEM TO THE UPPER TEENS. ARCTIC FRONT AND AN EXPANSIVE AREA OF STEEP 850-700 MB LAPSE RATES GREATER THAN 8C/KM WILL PLOW ACROSS THE STATE LATE FRIDAY IN THE NW...AND AFTER DARK - FRIDAY NIGHT ELSEWHERE. THIS SHOULD BE ONE OF THOSE ONCE IN A YEAR /OR SEVERAL YEAR/ EVENTS COMPLETE WITH DANGEROUS BLINDING SNOW SQUALLS CREATING WIDESPREAD TRAFFIC/TRAVEL PROBLEMS...FROM THE COMBINED EFFECT OF HEAVY FALLING AND BLOWING SNOW - AMOUNTING TO BETWEEN 1-3 INCHES IN A SHORT 30 TO 60 MINUTE PERIOD. THUNDER WAS ALSO MENTIONED IN THE GRIDDED WEATHER FIELDS...ESP ACROSS THE NW HALF OF THE STATE BASED ON THE LATE DAY/EVENING TIMING OF THE ARCTIC FROPA. WIND CHILLS DIP TO UNDER ADVISORY CRITERIA /-15F/ EARLY SAT MORNING ACROSS THE NRN MTNS...AND DROP TO NEAR OR SEVERAL DEG F BELOW ZERO ELSEWHERE BY THEN. && .LONG TERM /SATURDAY THROUGH THURSDAY/... *IMPACT WEATHER HIGHLIGHTS: FRIGID TEMPERATURES AND DANGEROUS WIND CHILLS FOR VALENTINES WEEKEND. POTENTIAL WINTER STORM EARLY NEXT WEEK. POLAR VORTEX DIVING INTO NORTHERN NEW ENGLAND WILL DELIVER THE COLDEST AIR OF THE SEASON WITH ARCTIC BLAST INTO CENTRAL PA SAT- SUN. THE GLOBAL MODELS AND ENSEMBLES KEEP A MEAN TROUGH IN PLACE OVER THE EASTERN US INTO THE MIDDLE OF NEXT WEEK. THE MOST NOTABLE FEATURE DURING THE PERIOD WILL BE A LOW PRESSURE SYSTEM TRACKING UP THE EAST COAST ON TUESDAY. THE LATEST 11/12Z MODEL GUIDANCE HAS TRENDED WEST WITH THE LOW TRACK...BUT THERE IS STILL A DECENT SPREAD. AT THIS TIME PRECIPITATION WITH THIS SYSTEM APPEARS LIKELY MON-TUE BUT THE TRACK WILL ULTIMATELY DETERMINE PRECIPITATION TYPE. NEXT WEEK SHOULD END ON A MILDER NOTE. THE COLDEST AIRMASS OF THE 2015-16 WINTER SEASON REMAINS POISED TO ARRIVE THIS WEEKEND...AS A BLAST OF ARCTIC AIR DELIVERS A SHORT DURATION COLD OUTBREAK TO CENTRAL PENNSYLVANIA. SNOW SQUALLS ARE LIKELY WITH THE ARCTIC FRONTAL PASSAGE FRIDAY NIGHT INTO SATURDAY. MAX/MIN TEMPERATURE DEPARTURES OF -20 TO -25 DEGREES BELOW CLIMO ARE FCST SATURDAY AND SUNDAY. MINIMUM TEMPERATURES SATURDAY NIGHT INTO EARLY SUNDAY MORNING RANGE FROM 0F IN THE LOWER SUSQ. VALLEY TO -10F IN THE NORTHWEST ALLEGHENIES. THE FRIGID TEMPERATURES COMBINED WITH DANGEROUS WIND CHILLS /-10 TO -25 BELOW ZERO/ WILL RESULT IN AN INCREASED RISK FOR FROSTBITE AND HYPOTHERMIA. A WIND CHILL WATCH WAS ISSUED FOR NORTHERN PA WHERE CONFIDENCE IS HIGH IN REACHING -25F WIND CHILLS. WIND CHILL HEADLINES ARE A GOOD BET IN LATER SHIFTS FOR THE REMAINDER OF THE AREA AND PRECAUTIONS SHOULD BE MADE NOW TO PROTECT/PREPARE FOR THE UPCOMING COLD SNAP. A MODERATION (WARMING TREND) IS EXPECTED INTO EARLY NEXT WEEK. THE MODEL SPREAD HAS NARROWED A BIT CONCERNING A POTENTIAL WINTER STORM SYSTEM IMPACTING THE MID ATLC/NORTHEAST NEXT MON-TUE. THE 11/12Z OPERATIONAL EC REMAINS ON THE WWD EDGE OF THE ENVELOPE FOLLOWED BY THE CANADIAN GEM AND GFS/GEFS. THE GFS/GEFS HAVE BOTH TRENDED WWD FROM THE PREVIOUS RUN. CONFIDENCE REMAINS LOW ON PTYPES BUT ALL THE MODELS ARE SIGNALING A SIGNIFICANT QPF EVENT...AND THEREFORE HAVE INCREASED POPS IN THE THE LKLY RANGE FOR DAY 5.5-6 /MON NGT-TUESDAY/. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... LAKE ENHANCED OROGRAPHIC SNOW WILL RESULT IN MAINLY IFR VSBYS AT KBFD/KJST THROUGH THIS AFTERNOON. THESE CONDITIONS WILL GRADUALLY IMPROVE BEGINNING THIS EVENING WHEN THE MEAN LLVL WIND BACKS FROM THE NW...TO A MORE WESTERLY DIRECTION AS HIGH PRESSURE SLIDES BY JUST TO OUR SOUTH ACROSS THE MIDDLE OHIO RIVER VALLEY. THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION AND OVER THE SUSQ VALLEY AIRFIELDS...MAINLY VFR AT 19Z...MAY DROP BRIEFLY TO UPPER MVFR CIGS AND VSBYS...WITH EVEN SOME VERY BRIEF IFR IN THE HEAVIER SNOW SHOWERS AND SQUALLS. A TIGHT PRES GRADIENT WILL BRING GUSTY WINDS UP TO 25KTS FOR THE REST OF THIS AFTERNOON AS DIURNAL HEATING/MIXING WITHIN THE RATHER DEEP BOUNDARY LAYER ALLOWS STRONGER WINDS ALOFT TO MIX TO GROUND LEVEL. ARRIVAL OF SFC RIDGE SHOULD BRING WIDESPREAD VFR CONDS AND DIMINISHING WIND TO CENTRAL PA THIS EVENING...AND CONTINUING THROUGH AT LEAST THE FIRST HALF OF FRIDAY. OUTLOOK... FRI...PM SHSN/VIS REDUCTIONS LIKELY...ESP W MTNS. PERIODS OF LIFR/VLIFR IN INTENSE SNOW SQUALLS LATE FRIDAY /NW/ AND FRIDAY NIGHT EARLY SAT MORNING CENTRAL AND SE. SAT...WINDY. SHSN/REDUCED VIS POSS W MTNS...MAINLY AM. SUN...NO SIG WX EXPECTED. MON...PM SNOW POSSIBLE. MON NIGHT AND TUE...SNOW LIKELY NW HALF OF PENN...WITH RAIN OR SNOW IN THE SE. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ005. WIND CHILL WATCH FROM LATE FRIDAY NIGHT THROUGH SUNDAY MORNING FOR PAZ004>006-037-041-042. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ004. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ010-017-024-033. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
305 PM EST THU FEB 11 2016 .SYNOPSIS... A PERSISTENT NORTHWEST WIND WILL KEEP LAKE EFFECT AND UPSLOPE SNOW SHOWERS GOING THE REST OF THIS AFTERNOON. AN ARCTIC BLAST WILL DELIVER THE COLDEST AIR OF THE SEASON FOR VALENTINES WEEKEND. THE ARCTIC FRONTAL BOUNDARY WILL BE ACCOMPANIED BY A ROUND OF BLINDING SNOW SQUALLS LATE FRIDAY AND FRIDAY NIGHT... FOLLOWED BY DANGEROUS COLD AND VERY LOW WIND CHILLS THAT ARE EXPECTED TO IMPACT THE AREA SATURDAY INTO SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... NUMEROUS...NARROW BANDS OF SNOW SHOWERS AND BRIEF SQUALLS CONTINUE TO STREAM SE AND WELL INLAND FROM THE GLAKES THIS AFTERNOON...MAKING IT ALL THE WAY INTO PORTIONS OF THE LOWER SUSQ VALLEY REGION /AND IN FACT...RIGHT TO THE MID ATLANTIC SEABOARD/. BRIEF...REDUCED VSBYS TO BETWEEN 1/4-1/2SM WILL IMPACT TRAVEL WITHIN THESE NARROW SNOW BANDS THAT COULD DROP UP TO ONE INCH OF FLUFF IN JUST A 30 MINUTE PERIOD. 18Z HRRR COMBINED WITH A LOOK AT THE LOW-MID LEVEL LAPSE RATES VIA THE NAM INDICATE THAT THE SNOW SHOWERS/BRIEF SQUALLS WILL CONTINUE UNTIL 23 THU-01Z FRIDAY BEFORE QUICKLY DISSIPATING AS THE SUBSIDENCE INVERSION DROPS FROM 7-8 KFT AGL...TO UNDER 4 KFT AGL. WILL MAINTAIN CURRENT WINTER WEATHER ADVISORIES OVER THE LAURELS AND WRN MTNS...AND LES WARNINGS AND ADVISORIES FOR THE FAR NW SNOWBELT WHERE PERSISTENT UPSLOPE AND LES SNOWS ARE EXPECTED TO CONTINUE INTO THIS EVENING. THE WIND WILL MAKE IT FEEL MUCH COLDER LATE TDY WITH WIND CHILLS BETWEEN -10 AND +10 ACROSS THE ENTIRE AREA. THE BLUSTERY CONDITIONS WILL JUST BE A TASTE OF WHAT LOOKS LIKE IS ON THE HORIZON FOR LATER FRIDAY NIGHT RIGHT INTO SUNDAY. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... SFC HIGH PRESSURE WILL SLIDE SOUTH OF THE STATE LATE TONIGHT BRINGING GRADUAL CLEARING. FLURRIES AND SCATTERED SNOW SHOWERS WILL LIFT NORTH EARLY TONIGHT AND BE CONFINED MAINLY TO THE NORTHERN TIER BY AROUND MIDNIGHT. TEMPS DROP INTO THE SINGLE DIGITS TONIGHT AS SOME CLEARING TAKES PLACE IN THE NW...BUT THE CALM AIR IN THE SE COULD CAUSE THE TEMPS THERE TO BECOME COLDER IN A FEW OF THE PERENNIAL COLD RURAL AREAS...SUCH AS SEG AND THV - MAKING THEM 3-5F COLDER THAN THE SURROUNDING LOCALES. THE FIRST PART OF FRIDAY SHOULD BE QUIET WITH PARTLY TO MOSTLY SUNNY SKIES AND RELATIVELY LIGHT WSW WIND. CLOUDS WILL QUICKLY INCREASE FROM THE SW AS SOME MEAGER WARM ADVECTION KICKS IN AHEAD OF THE WELL- ADVERTISED ARCTIC FRONT. SOME LIGHT SNOW/SNOW SHOWERS WILL DEVELOP DURING THE AFTN...BUT ACCUMS SHOULD BE MEAGER /GENERALLY UNDER 1/2 INCH. TEMPS WILL TRY TO GET INTO THE 20S ALL OVER BUT THE PERSISTENT CLOUD COVER IN THE NW WILL LIKELY LIMIT THEM TO THE UPPER TEENS. ARCTIC FRONT AND AN EXPANSIVE AREA OF STEEP 850-700 MB LAPSE RATES GREATER THAN 8C/KM WILL PLOW ACROSS THE STATE LATE FRIDAY IN THE NW...AND AFTER DARK - FRIDAY NIGHT ELSEWHERE. THIS SHOULD BE ONE OF THOSE ONCE IN A YEAR /OR SEVERAL YEAR/ EVENTS COMPLETE WITH DANGEROUS BLINDING SNOW SQUALLS CREATING WIDESPREAD TRAFFIC/TRAVEL PROBLEMS...FROM THE COMBINED EFFECT OF HEAVY FALLING AND BLOWING SNOW - AMOUNTING TO BETWEEN 1-3 INCHES IN A SHORT 30 TO 60 MINUTE PERIOD. THUNDER WAS ALSO MENTIONED IN THE GRIDDED WEATHER FIELDS...ESP ACROSS THE NW HALF OF THE STATE BASED ON THE LATE DAY/EVENING TIMING OF THE ARCTIC FROPA. WIND CHILLS DIP TO UNDER ADVISORY CRITERIA /-15F/ EARLY SAT MORNING ACROSS THE NRN MTNS...AND DROP TO NEAR OR SEVERAL DEG F BELOW ZERO ELSEWHERE BY THEN. && .LONG TERM /SATURDAY THROUGH THURSDAY/... *IMPACT WEATHER HIGHLIGHTS: SNOW SQUALLS LIKELY WITH ARCTIC FRONT FRIDAY NIGHT-SATURDAY. FRIGID TEMPERATURES AND DANGEROUS WIND CHILLS FOR VALENTINES WEEKEND. POLAR VORTEX DIVES FROM HUDSON BAY SOUTHEAST ACROSS QUEBEC AND NORTHERN NEW ENGLAND THURSDAY-SUNDAY. THE GLOBAL MODELS AND ENSEMBLE MEANS KEEP A `MILDER` TROUGH PATTERN IN PLACE OVER THE EASTERN US INTO NEXT WEEK. EMERGENCE OF SOUTHERN STREAM SHORTWAVE AND ITS INTERACTION WITH THE NORTHERN STREAM FLOW CREATES THE POTENTIAL FOR WINTER PRECIPITATION MON-WED BUT WITH A HIGH DEGREE OF UNCERTAINTY/LOW CONFIDENCE. A PATTERN SHIFT TO PACIFIC ZONAL-TO SOUTHWEST FLOW ALOFT WITH RISING/ABOVE NORMAL HEIGHTS IS FCST BY THE END OF NEXT WEEK. THIS FAVORS A RETURN TO MILDER WEATHER. LAKE EFFECT AND UPSLOPE SNOW SHOWERS CONTINUE INTO THE WEEKEND BEFORE TAPERING OFF ON SUNDAY...AS ARCTIC HIGH BUILDS OVER THE REGION. ADDITIONAL LIGHT SNOW ACCUMULATIONS ARE LIKELY IN THE FAVORED NORTHWEST SNOWBELT AND HIGHER TERRAIN ALONG THE ALLEGHENIES/LAUREL HIGHLANDS. THE COLDEST AIRMASS OF THE 2015-16 WINTER SEASON REMAINS POISED TO ARRIVE THIS WEEKEND...AS A BLAST OF ARCTIC AIR DELIVERS A SHORT DURATION COLD OUTBREAK TO CENTRAL PENNSYLVANIA. SNOW SQUALLS ARE LIKELY WITH THE ARCTIC FRONTAL PASSAGE FRIDAY NIGHT INTO SATURDAY. MAX/MIN TEMPERATURE DEPARTURES OF -20 TO -25 DEGREES BELOW CLIMO ARE FCST SATURDAY AND SUNDAY. MINIMUM TEMPERATURES SATURDAY NIGHT INTO EARLY SUNDAY MORNING RANGE FROM 0F IN THE LOWER SUSQ. VALLEY TO -10F IN THE NORTHWEST ALLEGHENIES. THE FRIGID TEMPERATURES COMBINED WITH DANGEROUS WIND CHILLS /-10 TO -25 BELOW ZERO/ WILL RESULT IN AN INCREASED RISK FOR FROSTBITE AND HYPOTHERMIA. WIND CHILL HEADLINES ARE A GOOD BET AND PRECAUTIONS SHOULD BE MADE NOW TO PROTECT/PREPARE FOR THE UPCOMING COLD SNAP. A MODERATION (WARMING TREND) IS EXPECTED INTO EARLY NEXT WEEK. THERE IS STILL A LOT OF SPREAD CONCERNING A POTENTIAL STORM SYSTEM IMPACTING THE NORTHEAST EARLY NEXT WEEK. THE OPERATIONAL EC REMAINS MORE BULLISH THAN THE GFS IN DEVELOPING A SIGNIFICANT CYCLONE AND HAS TRENDED EVEN FURTHER TO THE WEST WITH IS 10/12Z RUN. CONFIDENCE REMAINS LOW BUT THE SYSTEM WILL NEED TO BE MONITORED. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... LAKE ENHANCED OROGRAPHIC SNOW WILL RESULT IN MAINLY IFR VSBYS AT KBFD/KJST THROUGH THIS AFTERNOON. THESE CONDITIONS WILL GRADUALLY IMPROVE BEGINNING THIS EVENING WHEN THE MEAN LLVL WIND BACKS FROM THE NW...TO A MORE WESTERLY DIRECTION AS HIGH PRESSURE SLIDES BY JUST TO OUR SOUTH ACROSS THE MIDDLE OHIO RIVER VALLEY. THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION AND OVER THE SUSQ VALLEY AIRFIELDS...MAINLY VFR AT 19Z...MAY DROP BRIEFLY TO UPPER MVFR CIGS AND VSBYS...WITH EVEN SOME VERY BRIEF IFR IN THE HEAVIER SNOW SHOWERS AND SQUALLS. A TIGHT PRES GRADIENT WILL BRING GUSTY WINDS UP TO 25KTS FOR THE REST OF THIS AFTERNOON AS DIURNAL HEATING/MIXING WITHIN THE RATHER DEEP BOUNDARY LAYER ALLOWS STRONGER WINDS ALOFT TO MIX TO GROUND LEVEL. ARRIVAL OF SFC RIDGE SHOULD BRING WIDESPREAD VFR CONDS AND DIMINISHING WIND TO CENTRAL PA THIS EVENING...AND CONTINUING THROUGH AT LEAST THE FIRST HALF OF FRIDAY. OUTLOOK... FRI...PM SHSN/VIS REDUCTIONS LIKELY...ESP W MTNS. PERIODS OF LIFR/VLIFR IN INTENSE SNOW SQUALLS LATE FRIDAY /NW/ AND FRIDAY NIGHT EARLY SAT MORNING CENTRAL AND SE. SAT...WINDY. SHSN/REDUCED VIS POSS W MTNS...MAINLY AM. SUN...NO SIG WX EXPECTED. MON...PM SNOW POSSIBLE. MON NIGHT AND TUE...SNOW LIKELY NW HALF OF PENN...WITH RAIN OR SNOW IN THE SE. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ005. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ004. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ010-017-024-033. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1206 PM EST THU FEB 11 2016 .SYNOPSIS... A PERSISTENT NORTHWEST WIND WILL KEEP LAKE EFFECT AND UPSLOPE SNOW SHOWERS GOING THROUGH THIS AFTERNOON. AN ARCTIC BLAST WILL DELIVER THE COLDEST AIR OF THE SEASON FOR VALENTINES WEEKEND...PRECEDED BY A ROUND OF BLINDING SNOW SQUALLS LATE FRIDAY AND FRIDAY NIGHT...AND FOLLOWED BY DANGEROUS COLD AND VERY LOW WIND CHILLS THAT ARE EXPECTED TO IMPACT THE AREA SATURDAY INTO SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MULTIPLE NARROW BANDS OF SNOW SQUALLS CONTINUE TO STREAM SE AND WELL INLAND FROM THE GLAKES LATE THIS MORNING...MAKING IT ALL THE WAY INTO PORTIONS OF THE LOWER SUSQ VALLEY REGION /AND IN FACT...RIGHT TO THE MID ATLANTIC SEABOARD/. BRIEF...GREATLY REDUCED VSBYS POSE A SIGNIF IMPACT TO TRAVEL WITHIN THESE NARROW BUT RATHER INTENSE SNOW BANDS THAT COULD DROP UP TO ONE INCH OF FLUFF IN JUST A 15-20 MINUTE PERIOD. LATEST...15Z HRRR COMBINED WITH A LOOK AT THE LOW-MID LEVEL LAPSE RATES VIA THE NAM INDICATE THAT THE TARGET AREA FOR ONE OR TWO EXTENSIVE/INTENSE SQUALL BANDS SHOULD SHIFT TO THE NE HALF OF THE CWA THIS AFTERNOON AS MEAN BLYR WINDS BACK JUST 5-10 DEGREES. THESE SNOW BANDS WILL CONTINUE TO HAVE A GOOD DUAL LAKE CONNECTION FLOWING OVER THE LONG AXIS OF LAKE HURON. WILL FORECAST MAINLY A COATING TO ONE INCH ALONG AND NORTH OF A LINE FROM KUNV TO KSEG...HOWEVER SOME LOCATIONS IN THE CENTRAL MTNS AND WEST BRANCH/MIDDLE SUSQ VALLEY COULD SEE ANOTHER QUICK 2-3 INCHES OF FLUFFY/WIND BLOWN SNOW BETWEEN 14Z AND 23Z. SOME LOCATIONS MAY NEED TO BE PLACED IN A SHORT FUSED WINT WEATHER ADVIS DEPENDING ON EXACTLY WHERE THIS MESOSCALE FEATURE SETS UP. WILL BE MONITORING RADAR TRENDS AND HIGH RES MESO MODELS CLOSELY THIS AFTERNOON. WILL MAINTAIN CURRENT WINTER WEATHER ADVISORIES OVER THE LAURELS AND WRN MTNS...AND LES WARNINGS AND ADVISORIES FOR THE FAR NW SNOWBELT WHERE PERSISTENT UPSLOPE AND LES SNOWS ARE EXPECTED TO CONTINUE INTO THIS EVENING BEFORE THE MEAN LLVL FLOW BACKS MORE TO THE WEST AND THE SUBSIDENCE INVERSION BEGINS TO DROP QUICKLY FROM 7-8 KFT AGL...TO UNDER 4 KFT AGL. THE WIND WILL MAKE IT FEEL MUCH COLDER TODAY WITH WIND CHILLS BETWEEN -10 AND +10 ACROSS THE ENTIRE AREA ALL DAY LONG. THE BLUSTERY CONDITIONS WILL JUST BE A TASTE OF WHAT LOOKS LIKE IS ON THE HORIZON FOR SATURDAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... THE SNOW SHOWERS DO BEGIN TO TAPER OFF IN THE LATE AFTN AND EVENING. THE ACCUMS SHOULD BECOME NEGLIGABLE NOT TOO LONG AFTER SUNSET. THE END TIMING OF THE ADVYS/WARNING WILL BE KEPT AS IS AT 03Z. HOWEVER...MANY PLACES S OF ELK CO WILL SEE JUST A FLURRY OR TWO IN THE EVENING. TEMPS DROP INTO THE SINGLE DIGITS TONIGHT AS SOME CLEARING TAKES PLACE IN THE NW...BUT THE CALM AIR IN THE SE COULD CAUSE THE TEMPS THERE TO BECOME COLDER. SNOW PACK AND CALM AIR DO WONDERS TO MAKE IT COLDER THAN WE THINK IT WILL BE. WILL PAINT IN A DIP AROUND THE TYPICAL FRIDGES OF SEG AND THV - MAKING THEM 3-5F COLDER THAN THE SURROUNDING LOCALES. THE FIRST PART OF FRIDAY SHOULD BE QUIET SAVE A QUICK INCREASE IN CLOUDS FROM THE SW AS SOME MEAGER WARM ADVECTION KICKS IN AHEAD OF THE WELL-ADVERTISED ARCTIC FRONT. SOME LIGHT SNOW WILL PROBABLY BREAK OUT/SLIDE IN DURING THE AFTN. TEMPS WILL TRY TO GET INTO THE 20S ALL OVER BUT THE PERSISTENT CLOUD COVER IN THE NW WILL LIKELY KEEP THEM U20. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... *IMPACT WEATHER HIGHLIGHTS: SNOW SQUALLS LIKELY WITH ARCTIC FRONT FRIDAY NIGHT-SATURDAY. FRIGID TEMPERATURES AND DANGEROUS WIND CHILLS FOR VALENTINES WEEKEND. POLAR VORTEX DIVES FROM HUDSON BAY SOUTHEAST ACROSS QUEBEC AND NORTHERN NEW ENGLAND THURSDAY-SUNDAY. THE GLOBAL MODELS AND ENSEMBLE MEANS KEEP A `MILDER` TROUGH PATTERN IN PLACE OVER THE EASTERN US INTO NEXT WEEK. EMERGENCE OF SOUTHERN STREAM SHORTWAVE AND ITS INTERACTION WITH THE NORTHERN STREAM FLOW CREATES THE POTENTIAL FOR WINTER PRECIPITATION MON-WED BUT WITH A HIGH DEGREE OF UNCERTAINTY/LOW CONFIDENCE. A PATTERN SHIFT TO PACIFIC ZONAL-TO SOUTHWEST FLOW ALOFT WITH RISING/ABOVE NORMAL HEIGHTS IS FCST BY THE END OF NEXT WEEK. THIS FAVORS A RETURN TO MILDER WEATHER. LAKE EFFECT AND UPSLOPE SNOW SHOWERS CONTINUE INTO THE WEEKEND BEFORE TAPERING OFF ON SUNDAY...AS ARCTIC HIGH BUILDS OVER THE REGION. ADDITIONAL LIGHT SNOW ACCUMULATIONS ARE LIKELY IN THE FAVORED NORTHWEST SNOWBELT AND HIGHER TERRAIN ALONG THE ALLEGHENIES/LAUREL HIGHLANDS. THE COLDEST AIRMASS OF THE 2015-16 WINTER SEASON REMAINS POISED TO ARRIVE THIS WEEKEND...AS A BLAST OF ARCTIC AIR DELIVERS A SHORT DURATION COLD OUTBREAK TO CENTRAL PENNSYLVANIA. SNOW SQUALLS ARE LIKELY WITH THE ARCTIC FRONTAL PASSAGE FRIDAY NIGHT INTO SATURDAY. MAX/MIN TEMPERATURE DEPARTURES OF -20 TO -25 DEGREES BELOW CLIMO ARE FCST SATURDAY AND SUNDAY. MINIMUM TEMPERATURES SATURDAY NIGHT INTO EARLY SUNDAY MORNING RANGE FROM 0F IN THE LOWER SUSQ. VALLEY TO -10F IN THE NORTHWEST ALLEGHENIES. THE FRIGID TEMPERATURES COMBINED WITH DANGEROUS WIND CHILLS /-10 TO -25 BELOW ZERO/ WILL RESULT IN AN INCREASED RISK FOR FROSTBITE AND HYPOTHERMIA. WIND CHILL HEADLINES ARE A GOOD BET AND PRECAUTIONS SHOULD BE MADE NOW TO PROTECT/PREPARE FOR THE UPCOMING COLD SNAP. A MODERATION (WARMING TREND) IS EXPECTED INTO EARLY NEXT WEEK. THERE IS STILL A LOT OF SPREAD CONCERNING A POTENTIAL STORM SYSTEM IMPACTING THE NORTHEAST EARLY NEXT WEEK. THE OPERATIONAL EC REMAINS MORE BULLISH THAN THE GFS IN DEVELOPING A SIGNIFICANT CYCLONE AND HAS TRENDED EVEN FURTHER TO THE WEST WITH IS 10/12Z RUN. CONFIDENCE REMAINS LOW BUT THE SYSTEM WILL NEED TO BE MONITORED. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... LAKE ENHANCED OROGRAPHIC SNOW WILL RESULT IN MAINLY IFR VSBYS AT KBFD/KJST THROUGH THIS AFTERNOON. THESE OCNDITIONS WILL GRADUALLY IMPROVE BEGINNING THIS EVENING WHEN THE MEAN LLVL WINDS BACKS FROM THE NW...TO A MORE WESTERLY DIRECTION AS HIGH PRESSURE SLIDES BY JUST TO OUR SOUTH ACROSS THE MIDDLE OHIO RIVER VALLEY. THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION AND OVER THE SUSQ VALLEY AIRFIELDS...MAINLY VFR AT 17Z...WILL LIKELY DROP TO FREQUENT MVFR CIGS AND VSBYS...WITH EVEN SOME VERY BRIEF IFR IN THE HEAVIER SNOW SHOWERS AND SQUALLS. A TIGHT PRES GRADIENT WILL BRING GUSTY WINDS UP TO 25KTS THIS AFTERNOON AS DIURNAL HEATING/MIXING WITHIN DEEPENING BOUNDARY ALLOWS WINDS ALOFT TO MIX TO GROUND LEVEL. ARRIVAL OF SFC RIDGE SHOULD BRING WIDESPREAD VFR CONDS AND DIMINISHING WIND TO CENTRAL PA THIS EVENING. OUTLOOK... FRI...PM SHSN/VIS REDUCTIONS LIKELY...ESP W MTNS. SAT...WINDY. SHSN/REDUCED VIS POSS W MTNS...MAINLY AM. SUN...NO SIG WX EXPECTED. MON...PM SNOW POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ005. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ004. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ010-017-024-033. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...DANGELO/LAMBERT LONG TERM...STEINBUGL AVIATION...ROSS/LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1035 AM EST THU FEB 11 2016 .SYNOPSIS... A PERSISTENT NORTHWEST WIND WILL KEEP LAKE EFFECT AND UPSLOPE SNOW SHOWERS GOING ALL DAY. AN ARCTIC BLAST WILL DELIVER THE COLDEST AIR OF THE SEASON FOR VALENTINES WEEKEND WITH DANGEROUS COLD AND WIND CHILLS EXPECTED TO IMPACT THE AREA SATURDAY INTO SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 840 AM UPDATE... MULTIPLE NARROW BANDS OF SNOW SQUALLS CONTINUE TO STREAM SE AND WELL INLAND FROM THE GLAKES THIS MORNING...MAKING IT ALL THE WAY INTO PORTIONS OF THE LOWER SUSQ VALLEY REGION. BRIEF...GREATLY REDUCED VSBYS POSE A SIGNIF IMPACT TO TRAVEL WITHIN THESE VERY NARROW BUT RATHER INTENSE SNOW BANDS THAT COULD DROP UP TO ONE INCH OF FLUFF IN JUST A 15-20 MINUTE PERIOD. LATEST HRRR AND LOW-MID LEVEL LAPSE RATES VIA THE NAM INDICATE THAT THE TARGET AREA FOR ONE OR TWO EXTENSIVE/INTENSE SQUALL BANDS SHOULD SHIFT TO THE NE HALF OF THE CWA THIS AFTERNOON AS MEAN BLYR WINDS BACK JUST 5-10 DEGREES. THESE SNOW BANDS WILL CONTINUE TO HAVE A GOOD DUAL LAKE CONNECTION FLOWING OVER THE LONG AXIS OF LAKE HURON. WILL FORECAST MAINLY A COATING TO ONE INCH ALONG AND NORTH OF A LINE FROM KUNV TO KSEG...HOWEVER SOME LOCATIONS IN THE CENTRAL MTNS AND WEST BRANCH/MIDDLE SUSQ VALLEY COULD SEE ANOTHER QUICK 2-3 INCHES OF FLUFFY/WIND BLOWN SNOW BETWEEN 14Z AND 23Z. SOME LOCATIONS MAY NEED TO BE PLACED IN A SHORT FUSED WINT WEATHER ADVIS DEPENDING ON EXACTLY WHERE THIS MESOSCALE FEATURE SETS UP. WILL MAINTAIN CURRENT WINTER WEATHER ADVISORIES OVER THE LAURELS AND WRN MTNS...AND LES WARNINGS AND ADVISORIES FOR THE FAR NW SNOWBELT. THE WIND WILL MAKE IT FEEL MUCH COLDER TODAY WITH WIND CHILLS BETWEEN -10 AND +10 ACROSS THE ENTIRE AREA ALL DAY LONG. THE BLUSTERY CONDITIONS WILL JUST BE A TASTE OF WHAT LOOKS LIKE IS ON THE HORIZON FOR SATURDAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... THE SNOW SHOWERS DO BEGIN TO TAPER OFF IN THE LATE AFTN AND EVENING. THE ACCUMS SHOULD BECOME NEGLIGABLE NOT TOO LONG AFTER SUNSET. THE END TIMING OF THE ADVYS/WARNING WILL BE KEPT AS IS AT 03Z. HOWEVER...MANY PLACES S OF ELK CO WILL SEE JUST A FLURRY OR TWO IN THE EVENING. TEMPS DROP INTO THE SINGLE DIGITS TONIGHT AS SOME CLEARING TAKES PLACE IN THE NW...BUT THE CALM AIR IN THE SE COULD CAUSE THE TEMPS THERE TO BECOME COLDER. SNOW PACK AND CALM AIR DO WONDERS TO MAKE IT COLDER THAN WE THINK IT WILL BE. WILL PAINT IN A DIP AROUND THE TYPICAL FRIDGES OF SEG AND THV - MAKING THEM 3-5F COLDER THAN THE SURROUNDING LOCALES. THE FIRST PART OF FRIDAY SHOULD BE QUIET SAVE A QUICK INCREASE IN CLOUDS FROM THE SW AS SOME MEAGER WARM ADVECTION KICKS IN AHEAD OF THE WELL-ADVERTISED ARCTIC FRONT. SOME LIGHT SNOW WILL PROBABLY BREAK OUT/SLIDE IN DURING THE AFTN. TEMPS WILL TRY TO GET INTO THE 20S ALL OVER BUT THE PERSISTENT CLOUD COVER IN THE NW WILL LIKELY KEEP THEM U20. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... *IMPACT WEATHER HIGHLIGHTS: SNOW SQUALLS LIKELY WITH ARCTIC FRONT FRIDAY NIGHT-SATURDAY. FRIGID TEMPERATURES AND DANGEROUS WIND CHILLS FOR VALENTINES WEEKEND. POLAR VORTEX DIVES FROM HUDSON BAY SOUTHEAST ACROSS QUEBEC AND NORTHERN NEW ENGLAND THURSDAY-SUNDAY. THE GLOBAL MODELS AND ENSEMBLE MEANS KEEP A `MILDER` TROUGH PATTERN IN PLACE OVER THE EASTERN US INTO NEXT WEEK. EMERGENCE OF SOUTHERN STREAM SHORTWAVE AND ITS INTERACTION WITH THE NORTHERN STREAM FLOW CREATES THE POTENTIAL FOR WINTER PRECIPITATION MON-WED BUT WITH A HIGH DEGREE OF UNCERTAINTY/LOW CONFIDENCE. A PATTERN SHIFT TO PACIFIC ZONAL-TO SOUTHWEST FLOW ALOFT WITH RISING/ABOVE NORMAL HEIGHTS IS FCST BY THE END OF NEXT WEEK. THIS FAVORS A RETURN TO MILDER WEATHER. LAKE EFFECT AND UPSLOPE SNOW SHOWERS CONTINUE INTO THE WEEKEND BEFORE TAPERING OFF ON SUNDAY...AS ARCTIC HIGH BUILDS OVER THE REGION. ADDITIONAL LIGHT SNOW ACCUMULATIONS ARE LIKELY IN THE FAVORED NORTHWEST SNOWBELT AND HIGHER TERRAIN ALONG THE ALLEGHENIES/LAUREL HIGHLANDS. THE COLDEST AIRMASS OF THE 2015-16 WINTER SEASON REMAINS POISED TO ARRIVE THIS WEEKEND...AS A BLAST OF ARCTIC AIR DELIVERS A SHORT DURATION COLD OUTBREAK TO CENTRAL PENNSYLVANIA. SNOW SQUALLS ARE LIKELY WITH THE ARCTIC FRONTAL PASSAGE FRIDAY NIGHT INTO SATURDAY. MAX/MIN TEMPERATURE DEPARTURES OF -20 TO -25 DEGREES BELOW CLIMO ARE FCST SATURDAY AND SUNDAY. MINIMUM TEMPERATURES SATURDAY NIGHT INTO EARLY SUNDAY MORNING RANGE FROM 0F IN THE LOWER SUSQ. VALLEY TO -10F IN THE NORTHWEST ALLEGHENIES. THE FRIGID TEMPERATURES COMBINED WITH DANGEROUS WIND CHILLS /-10 TO -25 BELOW ZERO/ WILL RESULT IN AN INCREASED RISK FOR FROSTBITE AND HYPOTHERMIA. WIND CHILL HEADLINES ARE A GOOD BET AND PRECAUTIONS SHOULD BE MADE NOW TO PROTECT/PREPARE FOR THE UPCOMING COLD SNAP. A MODERATION (WARMING TREND) IS EXPECTED INTO EARLY NEXT WEEK. THERE IS STILL A LOT OF SPREAD CONCERNING A POTENTIAL STORM SYSTEM IMPACTING THE NORTHEAST EARLY NEXT WEEK. THE OPERATIONAL EC REMAINS MORE BULLISH THAN THE GFS IN DEVELOPING A SIGNIFICANT CYCLONE AND HAS TRENDED EVEN FURTHER TO THE WEST WITH IS 10/12Z RUN. CONFIDENCE REMAINS LOW BUT THE SYSTEM WILL NEED TO BE MONITORED. && .AVIATION /16Z THURSDAY THROUGH MONDAY/... LAKE ENHANCED OROGRAPHIC SNOW WILL RESULT IN MAINLY IFR VSBYS AT KBFD/KJST FEW NEXT SEVERAL HOURS. DRYING/DOWNSLOPING FLOW WILL RESULT IN PROGRESSIVELY MORE FAVORABLE CONDS EAST OF THE MTNS...WITH OCNL MVFR CIGS/FLURRIES POSSIBLE AT KAOO/KUNV AND A HIGH CONFIDENCE OF PREDOMINATELY VFR CONDS AT KIPT/KMDT/KLNS. SFC RIDGE BUILDING IN FROM THE OHIO VALLEY SHOULD CAUSE LAKE EFFECT SNOW SHOWERS TO DWINDLE THIS AFTN...WITH PREDOMINANTLY MVFR CONDS RETURNING TO KBFD/KJST AND VFR ELSEWHERE. A TIGHT PRES GRADIENT WILL BRING GUSTY WINDS UP TO 25KTS THIS AFTERNOON AS DIURNAL HEATING/MIXING WITHIN DEEPENING BOUNDARY ALLOWS WINDS ALOFT TO MIX TO GROUND LEVEL. ARRIVAL OF SFC RIDGE SHOULD BRING WIDESPREAD VFR CONDS AND DIMINISHING WIND TO CENTRAL PA THIS EVENING. OUTLOOK... FRI...PM SHSN/VIS REDUCTIONS LIKELY...ESP W MTNS. SAT...WINDY. SHSN/REDUCED VIS POSS W MTNS...MAINLY AM. SUN...NO SIG WX EXPECTED. MON...PM SNOW POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ005. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ004. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ010-017-024-033. && $$ SYNOPSIS...DANGELO/LAMBERT NEAR TERM...DANGELO/LAMBERT SHORT TERM...DANGELO LONG TERM...STEINBUGL AVIATION...ROSS/FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
856 AM EST THU FEB 11 2016 .SYNOPSIS... A PERSISTENT NORTHWEST WIND WILL KEEP LAKE EFFECT AND UPSLOPE SNOW SHOWERS GOING ALL DAY. AN ARCTIC BLAST WILL DELIVER THE COLDEST AIR OF THE SEASON FOR VALENTINES WEEKEND WITH DANGEROUS COLD AND WIND CHILLS EXPECTED TO IMPACT THE AREA SATURDAY INTO SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 840 AM UPDATE... MULTIPLE NARROW BANDS OF SNOW SQUALLS CONTINUE TO STREAM SE AND WELL INLAND FROM THE GLAKES THIS MORNING...MAKING IT ALL THE WAY INTO PORTIONS OF THE LOWER SUSQ VALLEY REGION. BRIEF...GREATLY REDUCED VSBYS POSE A SIGNIF IMPACT TO TRAVEL WITHIN THESE VERY NARROW BUT RATHER INTENSE SNOW BANDS THAT COULD DROP UP TO ONE INCH OF FLUFF IN JUST A 15-20 MINUTE PERIOD. LATEST HRRR AND LOW-MID LEVEL LAPSE RATES VIA THE NAM INDICATE THAT THE TARGET AREA FOR ONE OR TWO EXTENSIVE/INTENSE SQUALL BANDS SHOULD SHIFT TO THE NE HALF OF THE CWA THIS AFTERNOON AS MEAN BLYR WINDS BACK JUST 5-10 DEGREES. THESE SNOW BANDS WILL CONTINUE TO HAVE A GOOD DUAL LAKE CONNECTION FLOWING OVER THE LONG AXIS OF LAKE HURON. WILL FORECAST MAINLY A COATING TO ONE INCH ALONG AND NORTH OF A LINE FROM KUNV TO KSEG...HOWEVER SOME LOCATIONS IN THE CENTRAL MTNS AND WEST BRANCH/MIDDLE SUSQ VALLEY COULD SEE ANOTHER QUICK 2-3 INCHES OF FLUFFY/WIND BLOWN SNOW BETWEEN 14Z AND 23Z. SOME LOCATIONS MAY NEED TO BE PLACED IN A SHORT FUSED WINT WEATHER ADVIS DEPENDING ON EXACTLY WHERE THIS MESOSCALE FEATURE SETS UP. WILL MAINTAIN CURRENT WINTER WEATHER ADVISORIES OVER THE LAURELS AND WRN MTNS...AND LES WARNINGS AND ADVISORIES FOR THE FAR NW SNOWBELT. THE WIND WILL MAKE IT FEEL MUCH COLDER TODAY WITH WIND CHILLS BETWEEN -10 AND +10 ACROSS THE ENTIRE AREA ALL DAY LONG. THE BLUSTERY CONDITIONS WILL JUST BE A TASTE OF WHAT LOOKS LIKE IS ON THE HORIZON FOR SATURDAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... THE SNOW SHOWERS DO BEGIN TO TAPER OFF IN THE LATE AFTN AND EVENING. THE ACCUMS SHOULD BECOME NEGLIGABLE NOT TOO LONG AFTER SUNSET. THE END TIMING OF THE ADVYS/WARNING WILL BE KEPT AS IS AT 03Z. HOWEVER...MANY PLACES S OF ELK CO WILL SEE JUST A FLURRY OR TWO IN THE EVENING. TEMPS DROP INTO THE SINGLE DIGITS TONIGHT AS SOME CLEARING TAKES PLACE IN THE NW...BUT THE CALM AIR IN THE SE COULD CAUSE THE TEMPS THERE TO BECOME COLDER. SNOW PACK AND CALM AIR DO WONDERS TO MAKE IT COLDER THAN WE THINK IT WILL BE. WILL PAINT IN A DIP AROUND THE TYPICAL FRIDGES OF SEG AND THV - MAKING THEM 3-5F COLDER THAN THE SURROUNDING LOCALES. THE FIRST PART OF FRIDAY SHOULD BE QUIET SAVE A QUICK INCREASE IN CLOUDS FROM THE SW AS SOME MEAGER WARM ADVECTION KICKS IN AHEAD OF THE WELL-ADVERTISED ARCTIC FRONT. SOME LIGHT SNOW WILL PROBABLY BREAK OUT/SLIDE IN DURING THE AFTN. TEMPS WILL TRY TO GET INTO THE 20S ALL OVER BUT THE PERSISTENT CLOUD COVER IN THE NW WILL LIKELY KEEP THEM U20. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... *IMPACT WEATHER HIGHLIGHTS: SNOW SQUALLS LIKELY WITH ARCTIC FRONT FRIDAY NIGHT-SATURDAY. FRIGID TEMPERATURES AND DANGEROUS WIND CHILLS FOR VALENTINES WEEKEND. POLAR VORTEX DIVES FROM HUDSON BAY SOUTHEAST ACROSS QUEBEC AND NORTHERN NEW ENGLAND THURSDAY-SUNDAY. THE GLOBAL MODELS AND ENSEMBLE MEANS KEEP A `MILDER` TROUGH PATTERN IN PLACE OVER THE EASTERN US INTO NEXT WEEK. EMERGENCE OF SOUTHERN STREAM SHORTWAVE AND ITS INTERACTION WITH THE NORTHERN STREAM FLOW CREATES THE POTENTIAL FOR WINTER PRECIPITATION MON-WED BUT WITH A HIGH DEGREE OF UNCERTAINTY/LOW CONFIDENCE. A PATTERN SHIFT TO PACIFIC ZONAL-TO SOUTHWEST FLOW ALOFT WITH RISING/ABOVE NORMAL HEIGHTS IS FCST BY THE END OF NEXT WEEK. THIS FAVORS A RETURN TO MILDER WEATHER. LAKE EFFECT AND UPSLOPE SNOW SHOWERS CONTINUE INTO THE WEEKEND BEFORE TAPERING OFF ON SUNDAY...AS ARCTIC HIGH BUILDS OVER THE REGION. ADDITIONAL LIGHT SNOW ACCUMULATIONS ARE LIKELY IN THE FAVORED NORTHWEST SNOWBELT AND HIGHER TERRAIN ALONG THE ALLEGHENIES/LAUREL HIGHLANDS. THE COLDEST AIRMASS OF THE 2015-16 WINTER SEASON REMAINS POISED TO ARRIVE THIS WEEKEND...AS A BLAST OF ARCTIC AIR DELIVERS A SHORT DURATION COLD OUTBREAK TO CENTRAL PENNSYLVANIA. SNOW SQUALLS ARE LIKELY WITH THE ARCTIC FRONTAL PASSAGE FRIDAY NIGHT INTO SATURDAY. MAX/MIN TEMPERATURE DEPARTURES OF -20 TO -25 DEGREES BELOW CLIMO ARE FCST SATURDAY AND SUNDAY. MINIMUM TEMPERATURES SATURDAY NIGHT INTO EARLY SUNDAY MORNING RANGE FROM 0F IN THE LOWER SUSQ. VALLEY TO -10F IN THE NORTHWEST ALLEGHENIES. THE FRIGID TEMPERATURES COMBINED WITH DANGEROUS WIND CHILLS /-10 TO -25 BELOW ZERO/ WILL RESULT IN AN INCREASED RISK FOR FROSTBITE AND HYPOTHERMIA. WIND CHILL HEADLINES ARE A GOOD BET AND PRECAUTIONS SHOULD BE MADE NOW TO PROTECT/PREPARE FOR THE UPCOMING COLD SNAP. A MODERATION (WARMING TREND) IS EXPECTED INTO EARLY NEXT WEEK. THERE IS STILL A LOT OF SPREAD CONCERNING A POTENTIAL STORM SYSTEM IMPACTING THE NORTHEAST EARLY NEXT WEEK. THE OPERATIONAL EC REMAINS MORE BULLISH THAN THE GFS IN DEVELOPING A SIGNIFICANT CYCLONE AND HAS TRENDED EVEN FURTHER TO THE WEST WITH IS 10/12Z RUN. CONFIDENCE REMAINS LOW BUT THE SYSTEM WILL NEED TO BE MONITORED. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... LAKE ENHANCED OROGRAPHIC SNOW WILL RESULT IN PREDOMINANTLY IFR VSBYS AT KBFD/KJST THIS MORNING. DRYING/DOWNSLOPING FLOW WILL RESULT IN PROGRESSIVELY MORE FAVORABLE CONDS EAST OF THE MTNS...WITH OCNL MVFR CIGS/FLURRIES POSSIBLE AT KAOO/KUNV AND A HIGH CONFIDENCE OF PREDOMINATELY VFR CONDS AT KIPT/KMDT/KLNS. SFC RIDGE BUILDING IN FROM THE OHIO VALLEY SHOULD CAUSE LAKE EFFECT SNOW SHOWERS TO DWINDLE BY THIS AFTN...WITH PREDOMINANTLY MVFR CONDS RETURNING TO KBFD/KJST AND VFR ELSEWHERE. A TIGHT PRES GRADIENT OVR THE REGION IS ALREADY PRODUCING GUSTS IN EXCESS OF 20KTS ACROSS PARTS OF CENTRAL PA AT 12Z...AND MDL SOUNDINGS INDICATE GUSTS TO ARND 25KTS WILL BECOME WIDESPREAD BY LATE AM...AS DIURNAL HEATING/MIXING WITHIN DEEPENING BOUNDARY ALLOWS WINDS ALOFT TO MIX TO GROUND LEVEL. ARRIVAL OF SFC RIDGE SHOULD BRING WIDESPREAD VFR CONDS AND DIMINISHING WIND TO CENTRAL PA THIS EVENING. OUTLOOK... FRI...PM SHSN/VIS REDUCTIONS LIKELY...ESP W MTNS. SAT...WINDY. SHSN/REDUCED VIS POSS W MTNS...MAINLY AM. SUN...NO SIG WX EXPECTED. MON...PM SNOW POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ005. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ004. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ010-017-024-033. && $$ SYNOPSIS...DANGELO/LAMBERT NEAR TERM...DANGELO/LAMBERT SHORT TERM...DANGELO LONG TERM...STEINBUGL AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
248 AM EST THU FEB 11 2016 .SYNOPSIS... A PERSISTENT NORTHWEST FLOW WILL BRING A PROLONGED PERIOD OF LAKE EFFECT AND UPSLOPE SNOW SHOWERS THROUGHOUT THE NORTHWEST SNOWBELT AND ACROSS THE LAUREL HIGHLANDS. AN ARCTIC BLAST WILL DELIVER THE COLDEST AIR OF THE SEASON FOR VALENTINES WEEKEND WITH DANGEROUS COLD AND WIND CHILLS EXPECTED TO IMPACT THE AREA SATURDAY INTO SUNDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... IN THE NEAR TERM...OUR LINE OF SNOW SHOWERS AND SQUALLS HAS BEGUN TO WEAKEN AND BECOME MORE DISORGANIZED...MORE OR LESS ALONG THE LINES OF THE HIGH RES MESO MODELS. STILL LOOKING AT THE POSSIBILITY OF A QUICK COATING OF SNOW IN A FEW LOCATIONS AS THIS FEATURE SLIDES OFF TO THE SOUTHEAST. FOR THE LARGER PICTURE...PERSISTENT UPSLOPE SNOW SHOWERS AND FREQUENT LES FROM MEANDERING SNOW BANDS ACROSS THE FAR NW ZONES WILL BRING AN ADDITIONAL 1 TO 2 INCHES EVERY 4 TO 6 HOURS THROUGH TONIGHT...THOUGH PORTIONS OF NW WARREN COUNTY COULD SEE NEARLY DOUBLE THOSE SNOWFALL RATES. THE WELL-ALIGNED SFC-800 MB FLOW FROM ABOUT 270 DEGREES...WILL VEER TO ABOUT 295 DEG OVERNIGHT AS A SECONDARY COLD FRONT SWINGS SE THROUGH THE AREA. BASED ON THE MODERATELY STRONG...WELL ALIGNED...AND PERSISTENT 280-290 DEG FLOW THROUGH ABOUT 04Z FRIDAY...WE EXTENDED THE WINTER WX AND LES ADVISORIES AND WARNINGS OUT IN TIME THROUGH 03Z FRIDAY...AND EXPANDED THE WINT WX ADVIS NORTH TO COVER ELK AND CLEARFIELD COUNTIES. LATER TONIGHT...LOOK FOR VARIABLE AMOUNTS OF CLOUDS WITH SCATTERED FLURRIES ACROSS THE SUSQ VALLEY AND SOUTHERN TIER...WHILE A FEW BRIEF SNOW SHOWERS IN NARROW NW-SE STREAMERS OFF LAKE ERIE COULD ADD AN ADDITIONAL LIGHT COATING FROM KAOO TO KUNV. LOWS TONIGHT WILL VARY FROM 5-10F ACROSS THE NORTHERN AND WESTERN MTNS...TO THE UPPER TEENS IN THE SUSQ VALLEY. WIND CHILLS COULD DIP TO NEAR -10F AT TIMES LATE TONIGHT ACROSS THE NRN AND WRN MTNS...AND IN THE ZERO TO 10 ABOVE RANGE ACROSS THE CENTRAL AND SE ZONES...BUT WILL BE A GOOD 5 TO 10 DEG F ABOVE WIND CHILL ADVISORY CRITERIA IN ANY OF THESE LOCATIONS. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/... PERSISTENT...MEAN BLYR FLOW FROM 280-290 DEGREES WILL LEAD TO WIDESPREAD STRATO CU WITH CLOUD TEMPS ACROSS MUCH OF CENTRAL PENN FALLING WITHIN THE FAVORABLE DGZ OF -12 TO -18C. THIS WILL LEAD TO WIDESPREAD FLURRIES AND BRIEF SNOW SHOWERS FROM NARROW...AND SLOWLY MEANDERING BANDS. MESOSCALE MODELS SUCH AS THE HRRR AND 3 KM NCAR ENSEMBLE WILL PLAY AN IMPORTANT ROLE IN FORECASTING THE LOCATION...MVMT...AND SNOW FROM THESE FAIRLY WELL- ORGANIZED BUT NARROW SNOW BANDS THAT WILL REACH INTO THE CENTRAL RIDGE AND VALLEY REGION AT TIMES. ADDITIONAL SNOW ACCUMS OF A FEW TO SEVERAL INCHES WILL OCCUR DURING THE DAYLIGHT HOURS THURSDAY ACROSS THE NW MTNS AND LAUREL HIGHLANDS WHERE THE WINT WX AND LES ADVISORIES...AND LES WARNINGS WILL CONTINUE. MAX TEMPS THURSDAY WILL BE ONLY 12-25F WHICH IS AROUND 15 DEG F BELOW NORMAL FOR THIS TIME OF YEAR. THE BULK OF THE MORE SIGNIFICANT SNOW SHOWERS/LES SHOULD TAPER OFF/LIFT TO THE NORTH...CLOSELY HUGGING THE I-90 CORRIDOR AS MEAN BLYR WINDS BACK MORE TO THE WSW AFTER MIDNIGHT. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... *IMPACT WEATHER HIGHLIGHTS: SNOW SQUALLS LIKELY WITH ARCTIC FRONT FRIDAY NIGHT-SATURDAY. FRIGID TEMPERATURES AND DANGEROUS WIND CHILLS FOR VALENTINES WEEKEND. POLAR VORTEX DIVES FROM HUDSON BAY SOUTHEAST ACROSS QUEBEC AND NORTHERN NEW ENGLAND THURSDAY-SUNDAY. THE GLOBAL MODELS AND ENSEMBLE MEANS KEEP A `MILDER` TROUGH PATTERN IN PLACE OVER THE EASTERN US INTO NEXT WEEK. EMERGENCE OF SOUTHERN STREAM SHORTWAVE AND ITS INTERACTION WITH THE NORTHERN STREAM FLOW CREATES THE POTENTIAL FOR WINTER PRECIPITATION MON-WED BUT WITH A HIGH DEGREE OF UNCERTAINTY/LOW CONFIDENCE. A PATTERN SHIFT TO PACIFIC ZONAL-TO SOUTHWEST FLOW ALOFT WITH RISING/ABOVE NORMAL HEIGHTS IS FCST BY THE END OF NEXT WEEK. THIS FAVORS A RETURN TO MILDER WEATHER. LAKE EFFECT AND UPSLOPE SNOW SHOWERS CONTINUE INTO THE WEEKEND BEFORE TAPERING OFF ON SUNDAY...AS ARCTIC HIGH BUILDS OVER THE REGION. ADDITIONAL LIGHT SNOW ACCUMULATIONS ARE LIKELY IN THE FAVORED NORTHWEST SNOWBELT AND HIGHER TERRAIN ALONG THE ALLEGHENIES/LAUREL HIGHLANDS. THE COLDEST AIRMASS OF THE 2015-16 WINTER SEASON REMAINS POISED TO ARRIVE THIS WEEKEND...AS A BLAST OF ARCTIC AIR DELIVERS A SHORT DURATION COLD OUTBREAK TO CENTRAL PENNSYLVANIA. SNOW SQUALLS ARE LIKELY WITH THE ARCTIC FRONTAL PASSAGE FRIDAY NIGHT INTO SATURDAY. MAX/MIN TEMPERATURE DEPARTURES OF -20 TO -25 DEGREES BELOW CLIMO ARE FCST SATURDAY AND SUNDAY. MINIMUM TEMPERATURES SATURDAY NIGHT INTO EARLY SUNDAY MORNING RANGE FROM 0F IN THE LOWER SUSQ. VALLEY TO -10F IN THE NORTHWEST ALLEGHENIES. THE FRIGID TEMPERATURES COMBINED WITH DANGEROUS WIND CHILLS /-10 TO -25 BELOW ZERO/ WILL RESULT IN AN INCREASED RISK FOR FROSTBITE AND HYPOTHERMIA. WIND CHILL HEADLINES ARE A GOOD BET AND PRECAUTIONS SHOULD BE MADE NOW TO PROTECT/PREPARE FOR THE UPCOMING COLD SNAP. A MODERATION (WARMING TREND) IS EXPECTED INTO EARLY NEXT WEEK. THERE IS STILL A LOT OF SPREAD CONCERNING A POTENTIAL STORM SYSTEM IMPACTING THE NORTHEAST EARLY NEXT WEEK. THE OPERATIONAL EC REMAINS MORE BULLISH THAN THE GFS IN DEVELOPING A SIGNIFICANT CYCLONE AND HAS TRENDED EVEN FURTHER TO THE WEST WITH IS 10/12Z RUN. CONFIDENCE REMAINS LOW BUT THE SYSTEM WILL NEED TO BE MONITORED. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... LAKE ENHANCED OROGRAPHIC SNOW WILL RESULT IN PREDOMINANTLY IFR VSBYS AT KBFD/KJST THIS MORNING. A SLOW MOVING SFC TROUGH LYING ACROSS CENTRAL PA WILL ALSO PRODUCE OCNL IFR VSBYS AT KUNV UNTIL IT/S PASSAGE ARND 11Z. AFTER PASSAGE OF SFC TROUGH...EXPECT A TYPICAL LAKE EFFECT REGIME BTWN 11Z-17Z...WITH PREDOMINANTLY IFR VSBYS FROM LGT SNOW AT KBFD/KJST...POSSIBLE MVFR CIGS AT KAOO/KUNV AND A HIGH CONFIDENCE OF VFR CONDS AT THE LOWER ELEV AIRFIELDS FURTHER EAST...INCLUDING KIPT/KMDT/KLNS. SFC RIDGE BUILDING IN FROM THE OHIO VALLEY SHOULD CAUSE LAKE EFFECT SNOW SHOWERS TO DWINDLE BY THIS AFTN...WITH PREDOMINANTLY MVFR CONDS RETURNING TO KBFD/KJST AND VFR ELSEWHERE. A TIGHT PRES GRADIENT OVR THE REGION IS ALREADY PRODUCING GUSTS IN EXCESS OF 25KTS AT KJST EARLY THIS AM...AND MDL SOUNDINGS INDICATE SIMILAR GUSTS WILL DEVELOP ACROSS THE REST OF CENTRAL PA BY LATE AM...AS DIURNAL HEATING/MIXING WITHIN DEEPENING BOUNDARY ALLOWS WINDS ALOFT TO MIX TO GROUND LEVEL. ARRIVAL OF SFC RIDGE SHOULD BRING WIDESPREAD VFR CONDS AND DIMINISHING WIND TO CENTRAL PA THIS EVENING. OUTLOOK... FRI...PM SHSN/VIS REDUCTIONS LIKELY...ESP W MTNS. SAT...WINDY. SHSN/REDUCED VIS POSS W MTNS...MAINLY AM. SUN...NO SIG WX EXPECTED. MON...PM SNOW POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ005. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ004. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ010-017-024-033. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1200 AM EST THU FEB 11 2016 .SYNOPSIS... A PERSISTENT NORTHWEST FLOW WILL BRING A PROLONGED PERIOD OF LAKE EFFECT AND UPSLOPE SNOW SHOWERS THROUGHOUT THE NORTHWEST SNOWBELT AND ACROSS THE LAUREL HIGHLANDS. AN ARCTIC BLAST WILL DELIVER THE COLDEST AIR OF THE SEASON FOR VALENTINES WEEKEND WITH DANGEROUS COLD AND WIND CHILLS EXPECTED TO IMPACT THE AREA SATURDAY INTO SUNDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... IN THE NEAR TERM...OUR LINE OF SNOW SHOWERS AND SQUALLS HAS BEGUN TO WEAKEN AND BECOME MORE DISORGANIZED...MORE OR LESS ALONG THE LINES OF THE HIGH RES MESO MODELS. STILL LOOKING AT THE POSSIBILITY OF A QUICK COATING OF SNOW IN A FEW LOCATIONS AS THIS FEATURE SLIDES OFF TO THE SOUTHEAST. FOR THE LARGER PICTURE...PERSISTENT UPSLOPE SNOW SHOWERS AND FREQUENT LES FROM MEANDERING SNOW BANDS ACROSS THE FAR NW ZONES WILL BRING AN ADDITIONAL 1 TO 2 INCHES EVERY 4 TO 6 HOURS THROUGH TONIGHT...THOUGH PORTIONS OF NW WARREN COUNTY COULD SEE NEARLY DOUBLE THOSE SNOWFALL RATES. THE WELL-ALIGNED SFC-800 MB FLOW FROM ABOUT 270 DEGREES...WILL VEER TO ABOUT 295 DEG OVERNIGHT AS A SECONDARY COLD FRONT SWINGS SE THROUGH THE AREA. BASED ON THE MODERATELY STRONG...WELL ALIGNED...AND PERSISTENT 280-290 DEG FLOW THROUGH ABOUT 04Z FRIDAY...WE EXTENDED THE WINTER WX AND LES ADVISORIES AND WARNINGS OUT IN TIME THROUGH 03Z FRIDAY...AND EXPANDED THE WINT WX ADVIS NORTH TO COVER ELK AND CLEARFIELD COUNTIES. LATER TONIGHT...LOOK FOR VARIABLE AMOUNTS OF CLOUDS WITH SCATTERED FLURRIES ACROSS THE SUSQ VALLEY AND SOUTHERN TIER...WHILE A FEW BRIEF SNOW SHOWERS IN NARROW NW-SE STREAMERS OFF LAKE ERIE COULD ADD AN ADDITIONAL LIGHT COATING FROM KAOO TO KUNV. LOWS TONIGHT WILL VARY FROM 5-10F ACROSS THE NORTHERN AND WESTERN MTNS...TO THE UPPER TEENS IN THE SUSQ VALLEY. WIND CHILLS COULD DIP TO NEAR -10F AT TIMES LATE TONIGHT ACROSS THE NRN AND WRN MTNS...AND IN THE ZERO TO 10 ABOVE RANGE ACROSS THE CENTRAL AND SE ZONES...BUT WILL BE A GOOD 5 TO 10 DEG F ABOVE WIND CHILL ADVISORY CRITERIA IN ANY OF THESE LOCATIONS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... PERSISTENT...MEAN BLYR FLOW FROM 280-290 DEGREES WILL LEAD TO WIDESPREAD STRATO CU WITH CLOUD TEMPS ACROSS MUCH OF CENTRAL PENN FALLING WITHIN THE FAVORABLE DGZ OF -12 TO -18C. THIS WILL LEAD TO WIDESPREAD FLURRIES AND BRIEF SNOW SHOWERS FROM NARROW...AND SLOWLY MEANDERING BANDS. MESOSCALE MODELS SUCH AS THE HRRR AND 3 KM NCAR ENSEMBLE WILL PLAY AN IMPORTANT ROLE IN FORECASTING THE LOCATION...MVMT...AND SNOW FROM THESE FAIRLY WELL- ORGANIZED BUT NARROW SNOW BANDS THAT WILL REACH INTO THE CENTRAL RIDGE AND VALLEY REGION AT TIMES. ADDITIONAL SNOW ACCUMS OF A FEW TO SEVERAL INCHES WILL OCCUR DURING THE DAYLIGHT HOURS THURSDAY ACROSS THE NW MTNS AND LAUREL HIGHLANDS WHERE THE WINT WX AND LES ADVISORIES...AND LES WARNINGS WILL CONTINUE. MAX TEMPS THURSDAY WILL BE ONLY 12-25F WHICH IS AROUND 15 DEG F BELOW NORMAL FOR THIS TIME OF YEAR. THE BULK OF THE MORE SIGNIFICANT SNOW SHOWERS/LES SHOULD TAPER OFF/LIFT TO THE NORTH...CLOSELY HUGGING THE I-90 CORRIDOR AS MEAN BLYR WINDS BACK MORE TO THE WSW AFTER MIDNIGHT. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... *IMPACT WEATHER HIGHLIGHTS: SNOW SQUALLS LIKELY WITH ARCTIC FRONT FRIDAY NIGHT-SATURDAY. FRIGID TEMPERATURES AND DANGEROUS WIND CHILLS FOR VALENTINES WEEKEND. POLAR VORTEX DIVES FROM HUDSON BAY SOUTHEAST ACROSS QUEBEC AND NORTHERN NEW ENGLAND THURSDAY-SUNDAY. THE GLOBAL MODELS AND ENSEMBLE MEANS KEEP A `MILDER` TROUGH PATTERN IN PLACE OVER THE EASTERN US INTO NEXT WEEK. EMERGENCE OF SOUTHERN STREAM SHORTWAVE AND ITS INTERACTION WITH THE NORTHERN STREAM FLOW CREATES THE POTENTIAL FOR WINTER PRECIPITATION MON-WED BUT WITH A HIGH DEGREE OF UNCERTAINTY/LOW CONFIDENCE. A PATTERN SHIFT TO PACIFIC ZONAL-TO SOUTHWEST FLOW ALOFT WITH RISING/ABOVE NORMAL HEIGHTS IS FCST BY THE END OF NEXT WEEK. THIS FAVORS A RETURN TO MILDER WEATHER. LAKE EFFECT AND UPSLOPE SNOW SHOWERS CONTINUE INTO THE WEEKEND BEFORE TAPERING OFF ON SUNDAY...AS ARCTIC HIGH BUILDS OVER THE REGION. ADDITIONAL LIGHT SNOW ACCUMULATIONS ARE LIKELY IN THE FAVORED NORTHWEST SNOWBELT AND HIGHER TERRAIN ALONG THE ALLEGHENIES/LAUREL HIGHLANDS. THE COLDEST AIRMASS OF THE 2015-16 WINTER SEASON REMAINS POISED TO ARRIVE THIS WEEKEND...AS A BLAST OF ARCTIC AIR DELIVERS A SHORT DURATION COLD OUTBREAK TO CENTRAL PENNSYLVANIA. SNOW SQUALLS ARE LIKELY WITH THE ARCTIC FRONTAL PASSAGE FRIDAY NIGHT INTO SATURDAY. MAX/MIN TEMPERATURE DEPARTURES OF -20 TO -25 DEGREES BELOW CLIMO ARE FCST SATURDAY AND SUNDAY. MINIMUM TEMPERATURES SATURDAY NIGHT INTO EARLY SUNDAY MORNING RANGE FROM 0F IN THE LOWER SUSQ. VALLEY TO -10F IN THE NORTHWEST ALLEGHENIES. THE FRIGID TEMPERATURES COMBINED WITH DANGEROUS WIND CHILLS /-10 TO -25 BELOW ZERO/ WILL RESULT IN AN INCREASED RISK FOR FROSTBITE AND HYPOTHERMIA. WIND CHILL HEADLINES ARE A GOOD BET AND PRECAUTIONS SHOULD BE MADE NOW TO PROTECT/PREPARE FOR THE UPCOMING COLD SNAP. A MODERATION (WARMING TREND) IS EXPECTED INTO EARLY NEXT WEEK. THERE IS STILL A LOT OF SPREAD CONCERNING A POTENTIAL STORM SYSTEM IMPACTING THE NORTHEAST EARLY NEXT WEEK. THE OPERATIONAL EC REMAINS MORE BULLISH THAN THE GFS IN DEVELOPING A SIGNIFICANT CYCLONE AND HAS TRENDED EVEN FURTHER TO THE WEST WITH IS 10/12Z RUN. CONFIDENCE REMAINS LOW BUT THE SYSTEM WILL NEED TO BE MONITORED. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... OVERALL VFR CIGS AND VBSYS WILL BEGIN TO DOMINATE OVERNIGHT. THE SNOW CONVECTION SWITCHED FROM A WAVE TO A LINEAR BAND FEATURE. THE HRRR DID A DECENT JOB OF SHOWING THE SWITCH...HOWEVER FAILED TO SHOW THE INTENSITY. THE BIGGEST ISSUE WILL BE THE GUSTY WINDS INTERACTION WITH ANY SNOW...WHICH COULD THEN BRING MVFR OR LOWER VSBYS. THE BAND SHOULD BRIEFLY MOVE OVER UNV...BETWEEN 05 TO 07Z. OTHERWISE VFR SHOULD DOMINATE THROUGH THE CENTRAL AND WESTERN TAF SITES. BFD AND JST SHOULD REMAIN MAINLY MVFR WITH PERIODS OF IFR POSSIBLE THROUGH THE FIRST HALF OF TOMORROW MORNING AND WILL SLOWLY FADE BY TOMORROW EVENING. OUTLOOK... THU/THU NIGHT...MVFR WITH PERIODS OF IFR IN -SHSN ACROSS THE WRN PENN MTNS. MAINLY VFR ELSEWHERE. FRI...MVFR IN -SHSN...MAINLY LATE WITH STRONG COLD FRONT. SAT...MVFR IN -SHSN W MTNS. VFR OTHERWISE. WINDY. SUN...MVFR IN -SHSN IN W MTNS EARLY...OTHERWISE VFR. MON...VFR POSSIBLE EARLY ACROSS THE EASTERN HALF OF PENN...THEN LOWERING AND THICKENING CLOUDS LIKELY WITH A FEW PERIODS OF SNOW POSSIBLE...YIELDING MVFR TO IFR VSBYS AND CIGS. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THURSDAY FOR PAZ005. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THURSDAY FOR PAZ004. WINTER WEATHER ADVISORY UNTIL 10 PM EST THURSDAY FOR PAZ010- 017-024-033. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LAMBERT LONG TERM...STEINBUGL AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
914 PM CST FRI FEB 12 2016 .DISCUSSION...DEWPOINT TEMPERATURES HAVE RISEN TO THE UPPER 50S TO NEAR 60 OVER THE COASTAL PLAINS THIS EVENING. WINDS WILL CONTINUE TO DIMINISH TONIGHT AS A WEAK FRONTAL BOUNDARY FROM NORTH OF HOUSTON TO SOUTH OF SAN ANTONIO REMAINS ESSENTIAL QUASISTATIONARY TONIGHT. TEMP-DEWPOINT DEPRESSIONS WERE THE LOWEST AROUND THE MID COAST AT 03Z. 00Z HRRR ALONG WITH 00Z NAM SHOW FOG WILL FORM OVER THE MID COAST REGION INITIALLY JUST AFTER 06Z AND SPREAD WESTWARD INTO THE BRUSH COUNTRY OVERNIGHT. ADDED CALHOUN AND ARANSAS COUNTIES INTO THE DENSE FOG ADVISORY. MAY NEED TO HAVE ADVISORY FOR WEBB AND LA SALLE COUNTIES LATER TONIGHT BUT NOT CONFIDENT ENOUGH AT THIS POINT TO INCLUDE IN THE ADVISORY. && .PREV DISCUSSION... /ISSUED 601 PM CST FRI FEB 12 2016/ DISCUSSION...SEE AVIATION SECTION FOR 00Z TAFS. AVIATION...SEA BREEZE BOUNDARY WILL CONTINUE TO PUSH INLAND DURING THE EVENING HOURS...ALREADY PAST VCT AND ALI. HIGHER BOUNDARY LAYER MOISTURE WILL BE OVER THE COASTAL PLAINS INTO THE EASTERN BRUSH COUNTRY BY 06Z WHILE WINDS BECOME LIGHT. FOG/MVFR VSBYS EXPECTED TO DEVELOP 05-06Z IN THIS REGION WITH CONDITIONS DETERIORATING TO LIFR WITH DENSE FOG BY 07-08Z AND CONTINUE UNTIL AROUND 15Z. EXPECT THE LOW CLOUDS AND FOG/IFR CIGS AND MVFR VSBYS WILL REACH LRD AREA BY 11Z WITH LIFR VSBYS POSSIBLE IN NEAR DENSE FOG. VSBYS ARE EXPECTED TO IMPROVE BY 15-16Z TO VFR WITH MVFR CIGS HOLDING OVER VCT AREA THROUGH THE LATE MORNING BEFORE LIFTING. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 55 74 57 78 56 / 0 10 10 10 0 VICTORIA 50 71 54 75 57 / 0 10 10 10 10 LAREDO 54 82 55 83 53 / 0 0 0 0 0 ALICE 52 78 54 82 55 / 0 0 10 10 0 ROCKPORT 56 70 60 73 60 / 0 10 10 10 10 COTULLA 50 80 54 83 51 / 0 0 0 0 0 KINGSVILLE 52 77 54 78 56 / 0 0 0 10 10 NAVY CORPUS 56 71 60 73 59 / 0 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...DENSE FOG ADVISORY FROM 2 AM TO 10 AM CST SATURDAY FOR THE FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...DUVAL...GOLIAD... JIM WELLS...KLEBERG...LIVE OAK...MCMULLEN...NUECES... REFUGIO...SAN PATRICIO...VICTORIA. GM...NONE. && $$ TMT/89...SHORT TERM
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1141 PM CST WED FEB 10 2016 .AVIATION... VFR IS EXPECTED TO PREVAIL FOR THE 06Z TAFS. THE THOU/TIAH/KHGX VAD WIND PROFILERS ARE ALL SHOWING SOUTHWESTERLY WINDS INCREASING TO 35 TO 40 KNOTS AROUND 2000 FT AGL. HOUSTON IAH RAP FORECAST WIND PROFILES SHOW THESE WINDS MAINTAINING THIS INTENSITY JUST OFF THE SURFACE THROUGH 12Z AND THIS RAISES CONCERNS FOR AT LEAST BRIEF LLWS CONDITIONS FOR THE HOUSTON TERMINALS. AMENDMENTS TO INCLUDE LLWS MAY BE NEEDED IF SURFACE WINDS BECOME LIGHTER THAN CURRENTLY ANTICIPATED. OTHERWISE LIGHT SOUTHERLY/SOUTHWESTERLY WINDS OVERNIGHT WILL INCREASE TO 10 TO 15 KNOTS DURING THE DAY ON THURSDAY... WITH DAYTIME MIXING ALLOWING STRONGER GUSTS AROUND 20 TO POSSIBLY 25 KNOTS TO REACH THE SURFACE. AFTER 12/06Z... PATCHY RADIATION FOG DEVELOPMENT MAY IMPACT THE TERMINALS WITH AT LEAST TEMPORARY VISIBILITY/CEILING RESTRICTIONS POSSIBLE. HUFFMAN && .PREV DISCUSSION... /ISSUED 706 PM CST WED FEB 10 2016/ DISCUSSION... CLEAR SKIES AND A COOL NIGHT AHEAD. SOUTHWEST WINDS WILL CONTINUE MOST OF THE NIGHT ESPECIALLY ACROSS THE NORTHERN AND NORTHWESTERN AREAS. TWEAKED THE MIN TEMPS DOWN A DEGREE IN THE EAST WHERE THE AIR IS A LITTLE DRIER AND LIGHTER WINDS AND COOLER START TO THE EVENING...VERY MINOR CHANGES. MAY NEED TO DO AN UPDATE FOR SOME PATCHY SHALLOW FOG IN THE SW AREAS AROUND EDNA/WHARTON/PALACIOS/WEST COLUMBIA. MODEL SOUNDINGS SHOWING SOME VERY SHALLOW SATURATION OCCURRING BUT ATTM THINKING JUST ENOUGH WIND MAY KEEP ANY FOG AT BAY. 45 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 46 76 50 73 50 / 0 0 0 0 0 HOUSTON (IAH) 47 76 53 76 53 / 0 0 0 0 0 GALVESTON (GLS) 53 70 57 71 56 / 0 0 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CST THURSDAY FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...45 AVIATION/MARINE...14
AREA FORECAST DISCUSSION
NWS PORTLAND OR
342 AM PST THU FEB 11 2016 .SYNOPSIS...SOUTHWEST WASHINGTON AND NORTHWEST OREGON REMAIN IN THE SOUTHWEST FLOW ALOFT BETWEEN AN UPPER RIDGE INLAND OVER EASTERN WASHINGTON AND OREGON AND A LOW PRESSURE SYSTEM OUT NEAR 140W. A WEAK WARM FRONTAL BOUNDARY WILL LIFT NORTH TODAY...FOLLOWED BY THE ASSOCIATED COLD FRONT MOVING ONSHORE TONIGHT AND THROUGH THE FORECAST AREA ON FRIDAY. SNOW LEVELS WILL DROP DOWN TO PASS ELEVATIONS FRIDAY NIGHT AS ANOTHER DISTURBANCE MOVES THROUGH FOR SHOWERS. ANOTHER WARM FRONT WILL MOVE IN LATE SATURDAY AND SATURDAY NIGHT FOR MORE RAIN AND FOR SOME SNOW IN THE MOUNTAINS...THEN LINGER THROUGH SUNDAY AND PRODUCE MORE RAIN WHILE SNOW LEVELS RISE IN THE CASCADES. THE WARM FRONT WILL MOVE MOSTLY NORTH OF THE AREA SUNDAY NIGHT AND MONDAY. ANOTHER COLD FRONT WILL BRING SOME RAIN EARLY NEXT WEEK BEFORE THE MAIN COLDER UPPER TROUGH MOVES THROUGH MID TO LATE NEXT WEEK WITH FALLING SNOW LEVELS IN THE MOUNTAINS. && .SHORT TERM...A FRONTAL BOUNDARY FROM THE WEAK SYSTEM THAT MOVED THROUGH WEDNESDAY REMAINED OVER SOUTHWEST WASHINGTON AND NORTHWEST OREGON OVERNIGHT...AND IS FORECAST TO LIFT NORTH AS A WARM FRONT TODAY AND EARLY TONIGHT. THIS WILL BRING SOME AREAS OF RAIN TO SOUTHWEST WASHINGTON AND NORTHWEST OREGON AT TIMES TODAY INTO TONIGHT...ESPECIALLY ALONG THE COAST AND IN THE NORTH INTERIOR AREAS. ECHOES HAVE BEGUN PICKING UP OFF THE NORTH OREGON COAST ALREADY EARLY THIS MORNING...AND THIS MAY BE THE MAIN BOUNDARY. PRECIPITATION WILL MOVE NORTH INTO WESTERN WASHINGTON TODAY AND THIS EVENING...BUT WILL PROBABLY LINGER FROM ABOUT PORTLAND NORTH INLAND. THE ASSOCIATED COLD FRONT OUT AROUND 135W THIS MORNING IS FORECAST TO APPROACH THE COAST TONIGHT AND MOVE THROUGH IN THE INLAND AREAS IN THE MORNING AND EARLY AFTERNOON ON FRIDAY...AND SHOULD BE EAST OF THE CASCADES BY 4 PM FRIDAY. SNOW LEVELS WILL BE WELL ABOVE THE CASCADE PASSES FOR MOST OF THIS EVENT. SNOW LEVELS FALL TO BELOW THE PASSES FRIDAY NIGHT BEHIND THE FRONT AND AS A SHORT WAVE MOVES THROUGH THAT WILL PRODUCE A DECENT SHOT OF SHOWERS FRIDAY NIGHT AN SATURDAY MORNING. SNOW AMOUNTS LOOK A LITTLE BELOW ADVISORY AMOUNTS AT THIS POINT. THIS IS FORECAST TO BE FOLLOWED BY A WARM FRONT THAT WILL APPROACH THE COAST LATE SATURDAY AND BE OVER THE FORECAST AREA SATURDAY NIGHT AND SUNDAY. THE MODELS SHOW TWO GOOD WAVES MOVING ALONG THE WARM FRONT DURING THIS TIME FRAME...ONE SATURDAY NIGHT AND THE OTHER ON SUNDAY. SNOW LEVELS IN THE CASCADES WILL START BELOW THE CASCADE PASSES SATURDAY NIGHT BUT LIKELY RISE WELL ABOVE THE PASSES ON SUNDAY. THE BEST CHANCE OF SEEING ADVISORY AMOUNTS WOULD BE SATURDAY NIGHT BEFORE THE SNOW LEVEL RISES...ESPECIALLY IN THE NORTH CASCADES. TOLLESON .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS... SATURDAY NIGHT THROUGH WEDNESDAY...THE PROGRESSIVE WEATHER PATTERN WILL PERSIST INTO NEXT WEEK. MODELS CONTINUE TO SHOW A FRONT MOVING ACROSS THE PAC NW LATE SATURDAY/EARLY SUNDAY. HAVE INCREASED POPS ACROSS MUCH OF THE REGION SATURDAY EVENING TO ACCOUNT FOR THE FASTER TIMING OF THE ECMWF. NOT EXPECTING TO SEE A LOT OF CASCADE SNOW WITH THIS FRONT AS SNOW LEVELS QUICKLY RISE ABOVE 7000 FT EARLY SUNDAY. WE COULD SEE A BRIEF BREAK FROM THE RAIN MONDAY AS A TRANSIENT UPPER LEVEL RIDGE MOVES ACROSS THE REGION...BUT WILL MAINTAIN CHANCE POPS DUE TO SOME LINGERING INSTABILITY. A WEAK SHORTWAVE COULD BRING SOME LIGHT SHOWERS TUESDAY. ANOTHER FRONT ARRIVES LATE TUESDAY AND SHOULD BRING MORE RAIN AND CASCADE SNOW TO THE REGION...WITH SNOW LEVELS LOWERING TO AROUND 3500 FT WEDNESDAY AFTERNOON. TEMPS LOOK TO REMAIN SLIGHTLY ABOVE NORMAL THROUGH THE FORECAST...BUT WILL TREND COOLER AFTER MONDAY. /64 && .AVIATION...VFR ACROSS THE BOARD AT THIS HOUR.WITH CLOUD COVER LIKELY INHIBITING ANY POTENTIAL FOR WIDESPREAD FOG DEVELOPMENT. 00Z GFS20 TIME HEIGHTS ARE PROVING TO BE THE BEST CIG GUIDANCE OF THE AVAILABLE OPTIONS DURING THE DRY WEATHER OVER THE LAST COUPLE DAYS. CIGS MAY LOWER CLOSER TO 050 EARLY THIS MORNING BUT APPEAR TO GET STUCK THERE. MODELS HAVE CONTINUED TO WEAKEN THE INCOMING FRONT AND LAMP GUIDANCE CONTINUES TO TREND AWAY FROM IFR VSBY IMPACTS AT THE COASTAL TAF SITES OF KAST AND KONP AND ARE KEEPING CONDS AS MVFR CIG/VSBY IMPACTS. INLAND TAF TERMINALS DO NOT REACH MVFR FOR VERY LONG, IF AT ALL DURING THE NEXT 24 HOURS. KPDX AND APPROACHES...VFR CONDITIONS ARE THE MOST LIKELY SCENARIO THROUGH THE NEXT 24 HOURS. CIGS LOWERING TO MVFR OF 025-030 UNDER RAIN BANDS TODAY ARE POSSIBLE BUT ONLY GIVE ABOUT A 10-20 PCT CHANCE. BROAD OFFSHORE FLOW WILL BRING EASTERLY OUTFLOW WINDS FROM THE GORGE TODAY. /JBONK && .MARINE...NO SIGNIFICANTLY LARGE CHANGES TO THE FORECAST. ENP IS GENERALLY ON TRACK WITH THE INCOMING SWELL AS 10 FT COMBINED SEAS REACHED BUOY 89 AS OF THE 0200 HOUR. STILL COULD EXTEND THE SCA FOR SEAS OUT THROUGH SUNDAY AFTERNOON PER ENP GUIDANCE BUT PREFER TO KEEP IT COVERED FOR THE PERIODS OF HIGHER CONFIDENCE AT THIS TIME. CONFUSED SEAS WILL PREVAIL THROUGH THE BETTER PART OF THE EVENING BEFORE A SINGULAR WESTERLY SWELL WILL DOMINATE. DID LOWER WINDS FOR THIS FIRST WARM FRONTAL PERIOD AS THE SURFACE LOW WILL PIVOT NORTH AND WELL OFFSHORE WITH THE ASSOCIATED SURFACE TROUGH AND TIGHTEST PRESSURE GRADIENT MAINLY STAYING OVER THE OFFSHORE WATERS. IT WILL STILL COVER A DECENT PORTION OF THE OUTER WATERS. ITS SOMEWHAT QUESTIONABLE WHETHER THE INNER WATERS WILL GET MANY GUSTS ABOVE 21 KT TODAY BUT DONT FEEL CONFIDENT ENOUGH TO PULL DOWN THE ADVISORY. NEXT EVENT ON THE HORIZON APPEARS TO BE A POTENTIAL GALE EVENT SATURDAY NIGHT. MODELS HAVE COME INTO BETTER AGREEMENT THOUGH STILL DIFFER IN THE DETAILS. DECIDED TO TAKE A 50/50 BLEND OF THE GFS AND ECMWF WINDS FIELDS. THIS APPROACH YIELDED PEAK GUSTS 35-37 KTS SATURDAY NIGHT. PREFER TO SEE CONTINUED CONSISTENCY GIVEN THE WISHY-WASHY AND DECAYING STRENGTH NATURE OF THE MODELS OVER THE LAST COUPLE EVENTS. AFTER THAT...SEE A COUPLE SHORTER SCA TYPE EVENTS FOR NEXT WEEK. /JBONK && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 4 AM PST FRIDAY FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM-WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST SATURDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR WINDS FROM 4 PM THIS AFTERNOON TO 4 AM PST FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 10 NM-COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 10 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 9 AM PST THIS MORNING. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 4 PM THIS AFTERNOON TO 11 PM PST THIS EVENING. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion National Weather Service Spokane WA 307 AM PST THU FEB 11 2016 .SYNOPSIS... A warm front will move across the Inland Northwest today and tonight spreading a chance of rain across much of the area with snow levels at the highest mountain elevation except near the north Cascades. This front will be followed by the passage of a cold front on Friday which will bring another chance of precipitation to much of the area as well as slightly lower snow levels. Unsettled weather will continue through the weekend into early next week with valley rain, high mountain snow and breezy winds expected. Temperatures will be quite mild on Monday with many locations seeing highs in the mid 50s to low 60s. && .DISCUSSION... Today and tonight...The weather during this period will generally revolve around a developing warm front. As of 2am, the water vapor looper was showing a broad swath of moisture oriented from NNE-SSW right off the coast. Meanwhile the upper level ridge of high pressure remains poised over the Inland NW. The ridge is expected to amplify slightly over the area today and tonight, as height falls continue develop off the coast. Despite the presence of the ridge we should see the first chance of precipitation this week, the question is how soon will it develop and what will most of it fall as. Looking closely at the latest radar mosaics it appears the front will come through in two swaths. The first was responsible for the east-west band of light echoes extending along the WA/OR border and moving slowly northeastward. This one will likely weaken as it moves farther northward with weakening isentropic ascent, especially over the eastern third of Washington and north Idaho. If anything falls out of this band it will likely be very light. Over central Washington, the chances for measurable precipitation are a little better due to slightly deeper moisture combined with weak upslope flow into the Cascades. We suspect most of the precipitation will fall as rain, however north of Lake Chelan current wet-bulb temperatures are below freezing and they may not climb much this morning. So we expect to see primarily snow. The second surge of precipitation will bring a much better chance of measurable precipitation. This wave is likely a reflection of a compact shortwave located over northern California moving steadily northward. The HRRR suggests this second band will track into the Wenatchee and Moses Lake area around midday and then into NE Washington and north Idaho by late afternoon or early evening. Snow levels climb steadily with this portion of the warm front. Wet-bulb zero heights reach 6000 feet or higher across the entire forecast area save a small portion of the north Cascades mainly impacting the Methow Valley. It`s a tough call as to how effective the cold air damming will be in this area as the surrounding air mass is awfully warm. The 850 mb flow maintains a weak upslope orientation at least through early Friday which is favorable for keeping snow levels locally down to the valley floor, however surface temperature per bufkit profiles hover near or slightly above freezing. We put several inches of snow in the forecast across the upper Methow Valley however that`s assuming any snow which falls is able to accumulate rather than melting as it falls. Confidence is not high due to the precarious temperature profiles. Elsewhere we are much more confident about primarily a rain event. Rainfall totals should range from .15-35 inches across the northern mountains and extending into the northern Idaho Panhandle, with lighter amounts across southern Washington and the central Panhandle. Near the Cascades, precipitation amounts could range from 0.30-0.70 inches. For Friday, the ridge finally gives way and a sw-ne oriented upper level jet pokes into the southern portions of the region by midday. This will turn the steady warm frontal precipitation to more of a showery regime with most of the precipitation occurring near the cold front. The cold front will likely end the precipitation threat in the lee of the Cascades during the morning hours as the upslope flow turns to a downslope westerly regime. Meanwhile we expect the shower coverage to increase over the eastern third of Washington and over the Panhandle during the afternoon as the front destabilizes the atmosphere and enhances any orographic ascent. Generally speaking the precipitation amounts from the cold front will be lighter than whats produced from the warm front. Temperatures will remain milder both days over the eastern third of Washington and the Idaho Panhandle with highs in the 40s to middle 50s. Cooler temperatures will remain a fixture over central Washington today due to the cold air damming with highs in the 30s to lower 40s. The cold front should enhance mixing on Friday bringing an end to the inversions with highs climbing into the upper 30s to middle 40s. fx Friday night through Wednesday...A mild and unsettled weather pattern is expected this weekend through at least the middle of next week. Initially a slightly cooler air mass will move in Friday night and Saturday as an upper trough passes through. Mid level westerly flow will favor most of these showers for the Cascade crest and Idaho Panhandle. Snow levels by Saturday morning lower to 3000-4000 feet with snow showers expected over the mountain passes. Then an atmospheric river of subtropical moisture becomes aimed at the area Saturday night into Sunday. This will bring more rain and snow with snow levels rapidly rising from 2500-4000 feet initially early Sunday to 6000-7000 feet Monday as a warm front passes through. The atmospheric river begins to lift north Sunday night into Monday to near or just north of the Canadian border by Monday afternoon. Strong mid level westerly flow throughout this event will favor moderate to heavy precipitation for the Cascade crest and in the mountains of the Idaho Panhandle with added orographic lift...with mainly light amounts over Central and Eastern Washington as a strong rain shadow develops. Meanwhile Monday into Tuesday a surface low tracking into southern BC will result in a strengthening south- southwest winds which combined with the warmer air mass will lead to increased snow melt for areas that have snow currently. 850mb winds increasing to 30-45 kts will likely result in breezy to windy conditions over the region...especially the Upper Columbia Basin, Spokane area, and Palouse. JW && .AVIATION... 06Z TAFS: Weak wave exiting the forecast area this evening but a few lingering spotty showers remain. The ridge still remains in place with abundant low level moisture and overnight and early morning temperatures not too far from their dewpints...therfore another repeat of MVFR/IFR low stratus ceilings and IFR/LIFR fog remains in store overnight tonight and early Thursday Morning. Another weak disturbance will bring more light precipitation to the aviation area tomorrow. /Pelatti && .PRELIMINARY POINT TEMPS/POPS... Spokane 45 38 47 34 45 35 / 10 60 70 50 40 60 Coeur d`Alene 46 37 47 36 45 34 / 10 70 70 70 60 70 Pullman 51 40 52 38 47 36 / 20 30 40 60 40 70 Lewiston 55 44 57 41 54 40 / 10 20 30 50 30 60 Colville 40 34 41 33 43 35 / 10 80 80 50 50 60 Sandpoint 41 35 41 34 42 34 / 10 80 80 90 60 70 Kellogg 42 37 43 35 39 33 / 10 70 60 90 80 90 Moses Lake 46 38 49 34 52 38 / 20 50 40 30 10 40 Wenatchee 39 34 44 33 47 35 / 50 80 50 20 10 50 Omak 38 35 37 30 42 33 / 30 90 70 30 20 40 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...Air Stagnation Advisory until 10 AM PST Saturday for East Slopes Northern Cascades-Moses Lake Area-Northeast Mountains- Okanogan Highlands-Okanogan Valley-Upper Columbia Basin- Waterville Plateau-Wenatchee Area. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS LOS ANGELES/OXNARD CA
1022 PM PST FRI FEB 12 2016 .SYNOPSIS... A WEAK UPPER LEVEL TROUGH PASSING TO THE NORTH WILL PROVIDE A BRIEF BREAK FROM THE RECORD HEAT THIS WEEKEND. A BUILDING RIDGE ALOFT AND GUSTY OFFSHORE WINDS BRING A RETURN OF RECORD HEAT EARLY NEXT WEEK. A SECOND UPPER LEVEL LOW WILL SUPPORT MUCH COOLER CONDITIONS WITH THE CHANCE OF RAIN LATE WEDNESDAY INTO THURSDAY. && .SHORT TERM...(FRI-MON) UPPER LEVEL TROUGH MOVING INTO NORTHERN CALIFORNIA TONIGHT WITH RIDGE AXIS SLIDING WELL EAST OF OUR AREA. THIS HAS RESULTED IN SLIGHT ONSHORE TRENDS THIS EVENING...WITH CURRENT LAX-DAGGETT GRADIENT AT -1.9 MB. SATELLITE IMAGERY SHOWING AREAS OF LOW CLOUDS AND DENSE FOG ACROSS PORTIONS OF THE COASTAL WATERS (WHICH WAS HIGHLIGHTED WITH A MARINE WEATHER STATEMENT)...LOCALLY EXTENDING INTO THE CENTRAL COAST THIS EVENING. MOST OF THE FOG OFFSHORE OF LOS ANGELES COUNTY IS FORMING NEAR CATALINA ISLAND AND THE SAN PEDRO CHANNEL. BUT CONDITIONS ARE COMING TOGETHER FOR SOME PATCHY DENSE FOG JUST ABOUT ANYWHERE ALONG THE IMMEDIATE COAST TONIGHT...AND HAVE INCLUDED THAT IN ZONE UPDATE. COMBINATION OF SHALLOW/STRONG MARINE INVERSION...WEAKENING PRESSURE GRADIENTS...AND COASTAL DEWPOINTS RISING INTO THE MID 50S IS REASONING FOR POTENTIAL DENSE FOG ALONG IMMEDIATE COAST. AS THE TROUGH MOVES INLAND ON SATURDAY...THERE IS SOME INCREASING NORTHERLY FLOW SETTING UP ACROSS THE FORECAST AREA...ESPECIALLY TOMORROW NIGHT. INLAND AREAS NOT SHOWING A WHOLE LOT OF COOLING ON SATURDAY AT 950 MB LEVEL...SO BUMPED UP MOST VALLEY TEMPERATURES A FEW DEGREES IN EVENING UPDATE. TAKING A GLANCE AT THE 00Z NAM MODEL...SEEING ANOTHER RESURGENCE OF OFFSHORE FLOW FROM SUNDAY THROUGH TUESDAY WITH UPPER LEVEL RIDGE REBUILDING OVER THE AREA. STILL LOOKING LIKE STRONGEST OFFSHORE WIND PUSH WILL BE SUNDAY NIGHT INTO MONDAY WITH WIDESPREAD ADVISORIES LIKELY ACROSS VENTURA AND LOS ANGELES COUNTIES. WITH PROJECTED LAX-DAGGETT GRADIENT APPROACHING -7 MB ON SUNDAY MORNING AND SOME UPPER LEVEL WIND/THERMAL SUPPORT...COULD SEE SOME ISOLATED WIND GUSTS UP TO 60 MPH IN THE FAVORED MOUNTAIN AREAS. THE OFFSHORE WINDS WITH LOW HUMIDITIES AND WARM TEMPERATURES WILL BRING ANOTHER ROUND OF ELEVATED FIRE DANGER SUNDAY THROUGH TUESDAY. THE OTHER BIG STORY WILL CONTINUE TO BE THE UNUSUALLY HOT TEMPERATURES EXPECTED SUNDAY THROUGH TUESDAY...WITH MANY COASTAL/VALLEY AREAS EXPECTED TO CLIMB WELL INTO THE 80S AND LOWER 90S. ON SUNDAY...COULD SEE A COUPLE OF RECORDS BROKEN THEN EVEN BETTER CHANCE OF RECORDS BEING SET ON MONDAY AND TUESDAY. .LONG TERM...(TUE-FRI) FOR THE EXTENDED...12Z MODELS START OUT IN DECENT SYNOPTIC AGREEMENT...BUT DIVERGE LATER IN THE PERIOD. AT UPPER LEVELS RIDGE WILL LINGER ON TUESDAY THEN A TROUGH WILL APPROACH AND MOVES ACROSS THE WEST COAST WEDNESDAY THROUGH FRIDAY. NEAR THE SURFACE WEAK OFFSHORE FLOW WILL PREVAIL ON TUESDAY THEN SHIFT TO ONSHORE WEDNESDAY THROUGH FRIDAY. FORECAST-WISE...TUESDAY WILL BE AN UNREMARKABLE DAY WITH CLEAR SKIES...LIGHT OFFSHORE BREEZES AND HIGH TEMPERATURES WELL ABOVE NORMAL. FOR WEDNESDAY AND THURSDAY...THE MODELS DIVERGE NOTICEABLY LEADING TO A LOW CONFIDENCE FORECAST. THE ECMWF MOVES A TROUGH ACROSS THE AREA WEDNESDAY/THURSDAY AND GENERATES A DECENT RAIN EVENT FOR THE AREA. CONVERSELY...THE GFS IS MUCH LESS BULLISH WITH THIS TROUGH...HARDLY SPITTING OUT ANY PRECIPITATION. WITH SUCH MODELS DIFFERENCES...WILL NOT DEVIATE FROM PREVIOUS FORECAST THINKING WHICH INCLUDED CHANCE/SLIGHT CHANCE POPS FOR THE AREA WEDNESDAY AND THURSDAY. HOPEFULLY...MODELS WILL COME INTO SOME BETTER AGREEMENT OVER THE NEXT COUPLE OF DAYS. BY THURSDAY NIGHT AND FRIDAY...BOTH MODELS PUSH TROUGH EAST OF THE AREA AND INDICATE DRY CONDITIONS. && .AVIATION...13/0600Z. AT 0530Z...AT KLAX...THERE WAS A SURFACE BASED INVERSION LAYER TO 1700 FEET WITH A TEMP OF 24 DEG C. FOR COASTAL TAF SITES INCLUDING KSMX & KPRB...LOW CONFIDENCE IN THE 06Z TAFS THROUGH 16Z DUE THE POSSIBILITY OF FOG/LOW CLOUDS. EXPECT IFR TO LIFR WITH LOCALIZED VLIFR IN AREAS WHERE FOG/LOW CLOUDS DO DEVELOP. MODERATE TO HIGH CONFIDENCE FOR THE REMAINDER OF THE TAF PERIOD. INLAND TAF SITES...HIGH CONFIDENCE IN 06Z CAVU TAFS. KLAX...LOW CONFIDENCE IN 06Z TAF THROUGH 16Z DUE TO THE POSSIBILITY OF LOW FOG AND LOW CLOUDS. THERE IS A 40 PERCENT CHANCE OF LIFR TO VLIFR CIGS/VSBYS DUE TO FOG/LOW CLOUDS THROUGH 16Z. MODERATE CONFIDENCE IN THE REMAINDER OF THE TAF PERIOD. KBUR...HIGH CONFIDENCE IN 06Z CAVU TAF. && .MARINE...12/800 PM... A MARINE WEATHER STATEMENT WAS ISSUED THIS EVENING FOR THE POSSIBILITY OF DENSE FOG FOR ALL AREAS THROUGH SATURDAY MORNING. PLEASE SEE MWSLOX FOR DETAILS. FOR THE OUTER WATERS...THERE IS HIGH CONFIDENCE IN SMALL CRAFT ADVISORY (SCA) CONDITIONS THROUGH LATE SUNDAY NIGHT DUE TO EITHER SCA WINDS OR A 10-13 FT...LONG PERIOD W-NW SWELL. THE STRONGEST N-NW WINDS ACROSS THE OUTER WATERS ARE EXPECTED SATURDAY AFTERNOON AND NIGHT...WHEN THERE COULD BE SOME LOCAL GALE FORCE WINDS. SCA WINDS COULD LINGER INTO MONDAY...BUT SHOULD WEAKEN CONSIDERABLY BY TUESDAY. FOR THE INNER WATERS N OF PT CONCEPTION...THERE IS HIGH CONFIDENCE IN SCA CONDITIONS FOR HAZARDOUS SEAS THROUGH SUNDAY EVENING. THIS IS DUE TO THE 10-13 FT...LONG PERIOD W-NW SWELL. WINDS WILL GENERALLY REMAIN BELOW SCA CRITERIA...THROUGH THE FORECAST PERIOD...BUT THERE COULD BE SOME LOCAL N-NE GUSTS TO 25 KT SATURDAY EVENING THROUGH MONDAY EVENING. FOR THE INNER WATERS S OF PT CONCEPTION...THERE IS GOOD CONFIDENCE THAT WINDS AND SEAS WILL REMAIN BELOW SCA CRITERIA THROUGH SUNDAY AFTERNOON. HOWEVER...SOME 10 FT SEAS ARE POSSIBLE IN WESTERN PORTIONS OF THE SANTA BARBARA CHANNEL THROUGH SATURDAY AFTERNOON...DUE TO THE LONG PERIOD SWELL. THERE IS ALSO A CHANCE FOR SOME ISOLATED NE WIND GUSTS TO 25 KT ON SUNDAY MORNING BETWEEN SANTA MONICA AND VENTURA. STRONGER NE WINDS ARE EXPECTED LATE SUNDAY NIGHT INTO MONDAY...WHEN A SCA MAY BE NEEDED. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...HIGH SURF ADVISORY IN EFFECT UNTIL 9 AM PST SUNDAY FOR ZONES 34-35. (SEE LAXCFWLOX). BEACH HAZARDS STATEMENT IN EFFECT THROUGH SUNDAY MORNING FOR ZONE 39. (SEE LAXCFWLOX). HIGH SURF ADVISORY IN EFFECT UNTIL NOON PST SUNDAY FOR ZONES 40-41-87. (SEE LAXCFWLOX). PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IN EFFECT UNTIL 9 PM PST SUNDAY FOR ZONE 645. (SEE LAXMWWLOX). SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PST MONDAY FOR ZONES 670-673-676. (SEE LAXMWWLOX). && $$ PUBLIC...GOMBERG AVIATION...MUNROE/DB MARINE...SUKUP SYNOPSIS...MUNROE WEATHER.GOV/LOSANGELES
  [top] Area Forecast Discussion National Weather Service Sacramento CA 1015 PM PST FRI FEB 12 2016 .SYNOPSIS... Dry and mild weather through early next week with well above normal temperatures. Wetter and cooler weather pattern expected middle to latter portion of next week. && .DISCUSSION... Upper trof moving through Norcal with weakening surface front. CI/CS streaming into Interior NorCal is now sagging SEwd with upper trof. Moisture profiles from BUFKIT show high cloudiness eroding/ dissipating around 12z at the TAF sites in the Srn Sac/Nrn SJV with winds turning NW. This should limit/preclude widespread fog production. Subjective analysis is the HRRR is likely hitting the ) VSBYS too hard in the Vly Sat morning...and believe the fog will not be as dense or cover as much area as forecast. The patchy fog wording currently in the zones should suffice. JHM Heights and thicknesses progged to increase over the weekend as upper ridge amplifies off the West Coast. High temperatures forecast mainly in the lower 70s Saturday for the Central Valley, which is upwards of 10 to 12 degrees above normal and at record values for KSAC/KSCK. Some short lived patchy morning valley fog will continue to be possible over the weekend from Sacramento southward. Another weak weather system rides over the ridge Sunday with some light overrunning precip possible into far northern portions of CA. However associated precip continues to be modeled north of our forecast area. Surface high pressure building through Oregon into the Great Basin will result in some locally breezy northerly wind from Sunday afternoon into Monday. High temps expected to slowly trend up over the weekend into Monday. Max Ts in the Central Valley expected in the mid to upper 70s Sun/Mon with readings continuing right around record values for the Sacramento and Stockton areas. PCH .EXTENDED DISCUSSION (Tuesday THROUGH Friday) Conditions will remain dry through Tuesday. On Wednesday, NorCal transitions into a wet pattern as a trough impacts the west coast. Both the GFS & ECMWF models agree that this storm will start impacting our region by Wednesday evening. However, the challenge with this system is that the models disagree on the details. The GFS shows a quickly moving trough that weakens by Thursday morning and puts our region back into a dry, ridging pattern by Thursday afternoon/evening. The ECMWF indicates a stronger, wetter trough that keeps a threat of precipitation in our CWA through Thursday evening. Have medium confidence that interior NorCal will get light to moderate rain/snow Wednesday evening into Thursday afternoon with snow levels around 5000 ft. The models continue to diverge on Friday with the GFS maintaining a dry ridge while the ECMWF brings in another wave of precipitation that impacts area north of Interstate 80. Confidence is lower, but have kept lingering chances of precipitation through Friday until models come into better agreement. JBB && .AVIATION... SWly flow alf vrg to NWly Sat. Vrbl clds AOA FL120 for Intr NorCal nxt 24 hrs with VFR conds exc isold MVFR/IFR/LIFR poss in Srn Sac/Nrn San Joaquin vlys in BR/FG btwn 10z-18z Sat. && .STO Watches/Warnings/Advisories... None. && $$
AREA FORECAST DISCUSSION
NWS ALBANY NY
1235 AM EST SAT FEB 13 2016 .SYNOPSIS... AN ARCTIC COLD FRONT WILL SWEEP ACROSS THE REGION OVERNIGHT WITH ISOLATED TO SCATTERED SNOW SHOWERS AHEAD OF IT. BEHIND THE ARCTIC COLD FRONT...THE COLDEST AIRMASS OF THE SEASON WILL BUILD ACROSS THE REGION FOR THE WEEKEND WITH BITTERLY COLD TEMPERATURES AND WIND CHILLS. A STORM SYSTEM MAY IMPACT THE REGION MONDAY INTO THE MID WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1235 AM EST...AN ARCTIC COLD FRONT WAS POSITIONED JUST NORTH AND WEST OF THE FORECAST AREA AND POISED TO MOVE SOUTHWARD THROUGH THE OVERNIGHT HOURS. THE FRONT WILL BE MOVING THROUGH THE REGION BETWEEN 1 AM AND 6 AM FROM NW TO SE. AHEAD OF THIS FRONTAL BOUNDARY THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS...ALTHOUGH THE INTENSITY AND COVERAGE OF SNOW SHOWERS HAS DECREASED OVER THE PAST FEW HOURS REMOVED FROM THE MOISTURE SOURCE /LAKE ONTARIO/. THE LATEST 3-KM HRRR SHOWS SNOW SHOWERS WEAKENING AS THEY TRACK SOUTHEASTWARD THROUGH THE AREA ASSOCIATED WITH THE BOUNDARY. SNOWFALL AMOUNTS ARE EXPECTED TO BE ON THE LIGHT SIDE WITH GENERALLY A DUSTING TO 2 INCHES. THE HIGHER TOTALS WILL BE OVER THE WRN DACKS. IT WILL BE ANOTHER VERY COLD NIGHT...BUT NOT AS COLD AS TEMPERATURES WILL BE LATER IN THE WEEKEND. LOWS OVERNIGHT WILL RANGE FROM 10 BELOW ZERO NORTHWEST AREAS TO 15 ABOVE ZERO SOUTHEAST TOWARDS NW CT AND THE MID HUDSON RIVER VALLEY. WINDS WILL ALSO INCREASE OVERNIGHT ACROSS THE FCST AREA WITH A WIND CHILL WARNING STARTING AT 3 AM FOR THE SOUTHERN ADIRONDACKS...WESTERN MOHAWK VALLEY...EASTERN CATSKILLS AND SOUTHERN VERMONT. THE JAIL BREAK OF ARCTIC AIR KICKS IN...AS THE WINDS BEHIND THE FRONT WILL BE MAINLY WEST TO SOUTHWEST AT 10 TO 20 MPH WITH GUSTS TO 30-40 MPH. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/... WIND CHILL WARNINGS IN EFFECT FOR SATURDAY-SUNDAY MORNING FOR ALL OF EASTERN NEW YORK AND ADJACENT WESTERN NEW ENGLAND. THE COLDEST AIRMASS OF THE SEASON WILL BE WITH US OVER THE WEEKEND IN THE WAKE OF THE ARCTIC FRONT AS AN ARCTIC AREA OF HIGH PRESSURE SETTLES OVER THE REGION BY SUNDAY. H8 TEMPS DROP TO 27 TO 34 DEGREES BELOW ZERO BY SATURDAY EVENING. HAVE GONE WITH A NON- DIURNAL RANGE OF TEMPS ON SATURDAY AS THE LOWS FRIDAY NIGHT AND THE HIGHS ON SATURDAY SHOULD BE THE SAME WITH THE TEMPS DROPPING ALL DAY ON SATURDAY. TEMPS ARE EXPECTED TO DROP FROM 10 BELOW TO 15 ABOVE ZERO EARLY SATURDAY MORNING TO 15 BELOW ZERO TO 5 ABOVE ZERO BY EARLY SATURDAY EVENING. WIND CHILLS ON SATURDAY WILL RANGE FROM 10 BELOW TO 35 BELOW ZERO WITH NORTHWEST WINDS 10 TO 20 MPH WITH GUSTS 30 TO 40 MPH. SATURDAY NIGHT WILL BE ESPECIALLY BRUTAL AS AIR TEMPERATURES ARE EXPECTED TO DROP TO 5 BELOW TO NEAR 30 BELOW ZERO WITH WIND CHILL VALUES 25 BELOW TO NEAR 50 BELOW ZERO. SUNDAY INTO SUNDAY NIGHT...HIGH PRESSURE WILL MOVE OVER OUR REGION ON SUNDAY AND OFF THE EASTERN SEABOARD LATE SUNDAY NIGHT. WINDS WILL STILL BE FAIRLY STRONG ON SUNDAY MORNING BEFORE SUBSIDING LATER SUNDAY INTO SUNDAY NIGHT. HIGHS ON SUNDAY WILL BE IN THE ZERO TO 15 ABOVE ZERO RANGE WITH THE LOWS SUNDAY NIGHT BETWEEN 10 BELOW AND 5 ABOVE ZERO. MONDAY WILL FEATURE INCREASING CLOUDS AS THE NEXT SYSTEM STARTS TO TRACK NORTHEASTWARD FROM THE SOUTHEAST COAST. HIGHS WILL MODERATE ON MONDAY RANGING FROM THE UPPER TEENS NORTHWEST TO UPPER 20S SOUTHEAST WITH A CHANCE OF SNOW ACROSS THE SOUTHERN HALF OF THE FA LATE IN THE DAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A SIGNIFICANT STORM IS EXPECTED TO IMPACT THE REGION DURING THE EARLY PART OF THE EXTENDED PERIOD. THERE IS INCREASING CONFIDENCE AS TO THE TRACK AND INTENSITY OF THIS SYSTEM... AT LEAST IN ITS EARLY STAGES. TWO TO SIX INCH ACCUMULATIONS ARE EXPECTED MONDAY NIGHT... WHICH IS MORE OR LESS THE START OF THE EVENT. BEYOND THAT THERE IS STILL UNCERTAINTY AS TO PRECIPITATION TYPE AS THERE IS PLENTY OF MILD AIR TO BE DRAWN IN OUT AHEAD OF THIS SYSTEM...THUS THE EXACT TRACK AND INTENSITY WILL BE CRUCIAL. RIGHT NOW...THE TRACK IS EXPECTED TO BE FROM ABOUT CHARLOTTE NORTH CAROLINA THROUGH ALBANY. BECAUSE THE TRACK IS NOT SEEN AS GOING FAR ENOUGH TO THE EAST TO GIVE US AN ALL SNOW EVENT...INDICATIONS ARE PRECIPITATION WILL LIKELY CHANGE OVER TO RAIN FOR A TIME ON TUESDAY...PARTICULARLY OUTSIDE OF THE ADIRONDACKS...BEFORE EVERYTHING TAPERS OFF AS SNOW TUESDAY NIGHT. THERE IS THE POTENTIAL FOR VERY SIGNIFICANT ACCUMULATIONS...BUT ANY DECENT PERIOD OF RAIN...AS IS EXPECTED RIGHT NOW...WILL KEEP SNOW ACCUMULATIONS AT BAY. BROAD LAKE ENHANCEMENT ON INCREASING WESTERLY WINDS BEHIND THE DEPARTING STORM WILL KEEP SNOW SHOWERS OF LIGHT AMOUNTS GOING FOR MANY AREAS TUESDAY NIGHT...WITH MIXED RAIN AND SNOW SHOWERS FOR WEDNESDAY. BUT THE ACTIVITY WILL WIND DOWN RAPIDLY ON THURSDAY AS HIGH PRESSURE SETTLES IN...BUT WITHOUT THE EXTREME COLD WE/RE EXPECTING THIS WEEKEND. HIGH TEMPERATURES ARE EXPECTED TO RANGE FROM THE MID 30S THROUGH THE UPPER 40S ON TUESDAY...THE UPPER 20S TO AROUND 40 DEGREES ON WEDNESDAY...AND THE MID TEENS TO AROUND 30 DEGREES ON THURSDAY. FRIDAY HIGHS WILL REBOUND SOMEWHAT. OVERNIGHT LOWS MONDAY NIGHT WILL RANGE FROM THE UPPER TEENS IN THE MOUNTAINS TO THE UPPER 20S IN THE LOWER MID HUDSON VALLEY. TUESDAY NIGHT...THEY WILL RANGE FROM THE MID 20S IN THE WESTERN ADIRONDACKS...TO THE LOWER 30S DOWN THE HUDSON VALLEY. WEDNESDAY NIGHT WILL TURN SHARPLY COLDER...AND THURSDAY NIGHT WILL BE COLDEST...WITH LOWS RANGING FROM THE LOW SINGLE DIGITS IN THE WESTERN ADIRONDACKS...TO THE UPPER TEENS DOWN THE MID HUDSON VALLEY. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... A CLIPPER LOW WILL PASS NORTH OF THE REGION THROUGH THE EARLY MORNING HOURS...AS THE ASSOCIATED ARCTIC COLD FRONT TRACKS THROUGH. A NW FLOW OF ARCTIC AIR WILL IMPACT THE REGION THROUGH THE DAY INTO THE NIGHT PERIOD WITH GUSTY WINDS. THE ARCTIC FRONT WILL FOCUS SOME ISOLATED TO SCATTERED SNOW SHOWERS OR A SQUALL FROM THE CAPITAL REGION NORTH...IMPACTING KGFL/KALB/KPSF BETWEEN 04Z-09Z. THE SNOW SHOWERS WILL BE FAIRLY ISOLATED TO SCATTERED IN COVERAGE DUE TO VERY LIMITED LOW-LEVEL MOISTURE. A VCSH WAS USED AT KALB/KPSF/KGFL THROUGH ABOUT 10-11Z. VFR CONDITIONS WILL BE DOMINATE...ASIDE FOR SOME MVFR CIGS/VSBYS WITH ANY SNOW SHOWERS/ISOLD SQUALLS ESPECIALLY AT KPSF/KGFL. CIGS WILL BE MAINLY IN THE 4-9 KFT AGL RANGE. IN THE WAKE OF THE FRONT AFTER DAYBREAK...SOME LINGERING STRATOCUMULUS OR MID LEVEL CLOUDS WILL LINGER. OVERALL...VFR CONDITIONS WILL CONTINUE IN THE FRIGID NORTHWEST FLOW THROUGH THE PM. THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 4-10 KTS PRIOR TO THE FRONTAL PASSAGE BEFORE DAYBREAK...THEN VEER TO THE W TO NW AT 6- 12 KTS WITH SOME GUSTS TO 20-25 KTS. THE WINDS WILL INCREASE IN THE WAKE OF THE ARCTIC FRONT LATE IN THE MORNING INTO THE AFTERNOON AT 12-20 KTS WITH SOME GUSTS AROUND 30 KTS...ESPECIALLY AT KALB/KPSF. WINDS WILL SLOWLY DIMINISH DURING THE EVENING BUT WILL STILL BE GUSTY. THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 4-10 KTS PRIOR TO MIDNIGHT...THEN VEER TO THE W TO NW AT 6-12 KTS BEFORE DAYBREAK WITH SOME GUSTS TO 20-25 KTS. THE WINDS WILL INCREASE IN THE WAKE OF THE ARCTIC FRONT LATE TOMORROW MORNING INTO THE AFTERNOON AT 12-20 KTS WITH SOME GUSTS AROUND 30 KTS...ESPECIALLY AT KALB/KPSF. OUTLOOK... SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SN. SUNDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SN. WASHINGTONS BIRTHDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...SN. MONDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... WITH BITTER COLD AIR IN PLACE...ICE COVERAGE ON RIVERS AND LAKES WILL CONTINUE TO INCREASE AND STRENGTHEN OVER THE NEXT FEW DAYS. A FEW LIGHT SNOW SHOWERS ARE POSSIBLE...MAINLY THIS EVENING...BUT THIS WILL AMOUNT TO LITTLE IF ANY HYDROLOGIC SIGNIFICANCE. HOWEVER...THERE IS THE POTENTIAL FOR A HEAVY PRECIPITATION EVENT TO IMPACT THE REGION FROM MONDAY NIGHT THROUGH WEDNESDAY. THERE REMAINS CONSIDERABLE UNCERTAINTY REGARDING THE TYPES OF PRECIPITATION THAT MAY OCCUR...WHICH WILL ULTIMATELY DEPEND ON THE EXACT TRACK OF THIS POTENTIAL STORM SYSTEM. AT THIS TIME...MODEL GUIDANCE IS SUGGESTING ONE TO THREE INCHES OF LIQUID EQUIVALENT COULD OCCUR...AND MUCH OF THIS COULD BE IN THE FORM OF RAIN. IF THIS RAIN WERE TO MATERIALIZE...IT COULD HAVE A HIGH IMPACT ON RIVERS AND STREAMS...ESP CONSIDERING THE GROUND WILL BE FULLY FROZEN BY THAT TIME...ALLOWING MUCH OF THE PRECIP TO BE RUNOFF. DETAILS WILL BECOME MORE CERTAIN OVER THE NEXT FEW DAYS. 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...WIND CHILL WARNING FROM 1 PM THIS AFTERNOON TO 1 PM EST SUNDAY FOR CTZ001-013. NY...WIND CHILL WARNING UNTIL 1 PM EST SUNDAY FOR NYZ032-033-038- 042-047-051-058-063-082. WIND CHILL WARNING FROM 1 PM THIS AFTERNOON TO 1 PM EST SUNDAY FOR NYZ039>041-043-048>050-052>054-059>061-064>066-083- 084. MA...WIND CHILL WARNING FROM 1 PM THIS AFTERNOON TO 1 PM EST SUNDAY FOR MAZ001-025. VT...WIND CHILL WARNING UNTIL 1 PM EST SUNDAY FOR VTZ013>015. && $$ SYNOPSIS...IRL/WASULA NEAR TERM...11/JPV/WASULA SHORT TERM...11 LONG TERM...ELH AVIATION...NAS HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
349 AM EST SAT FEB 13 2016 .DISCUSSION... ...POOR TO HAZARDOUS BOATING CONDITIONS THIS WEEKEND... TODAY-TONIGHT... LATEST ANALYSIS SHOWS A DRY COLD FRONT PUSHING INTO THE PANHANDLE... A LITTLE SLOWER THAN ANTICIPATED. THE 00Z KJAX/KTAE RAOBS INDICATE PWATS ONLY ARND 0.75"...WHILE LATEST SAT PICS SHOW A FEW CLOUD BANDS DVLPG AHEAD OF THE FRONT IN TANDEM WITH A BAND OF H100-H85 DEWPOINT DEPRESSIONS BTWN 3-5C OVER THE NRN PENINSULA. AHEAD OF THE FRONT... HOWEVER...A DRY/STABLE AIRMASS REMAINS IN PLACE. THE 00Z RAOBS AT KXMR/KTBW/KMFL MEASURED PWAT VALUES ARND 0.50"...WHILE RAP ANALYSIS INDICATES H100-H85 DEWPOINT DEPRESSIONS BTWN 5-7C ALONG THE I-4 CORRIDOR...ARND 15C OVER LAKE OKEECHOBEE AND THE TREASURE COAST. AS EXPECTED...THE APPROACHING FRONTAL TROF HAS ERODED THE H100-H70 RIDGE/ANTICYCLONE AXIS THAT WAS IN PLACE OVER THE FL PENINSULA ON FRI. THE RIDGE HAS EFFECTIVELY SPLIT IN TWO WITH THE WRN HALF RETROGRADING INTO THE WRN GOMEX...THE ERN HALF PUSHING WELL E OF THE BAHAMA BANK TO MERGE WITH THE ATLC SUBTROPICAL RIDGE. THIS WILL LEAVE THE FRONT WITH LITTLE IMPEDANCE TO SLOW ITS FORWARD MOTION... ESPECIALLY GIVEN THE RAP40 INDICATES AVG H100-H70 FLOW BEHIND IT IS NW AT 25-30KTS. ANOTHER QUIET WX DAY IN STORE AS FRONTAL MOISTURE IS SIMPLY TOO LOW TO SUPPORT THE FORMATION OF ANYTHING MORE THAN A LOW LVL CLOUD DECK...MEAN RH VALUES THRU THE H100-H85 LYR ARE AOB 80PCT. FURTHERMORE...RAOBS SHOW A LINGERING SUBSIDENCE INVERSION IN THE H90-H80 LYR THAT WILL PANCAKE ANY CLOUD DECK BLO 5KFT. TEMPS WILL BE A BIT ON THE COOL SIDE FROM BREVARD/OSCEOLA CO NWD ONCE THE FRONT PUSHES THRU AS NWRLY FLOW DVLPS...KEEPING AFTN READINGS IN THE L/M60S DESPITE NEAR FULL SUN. TREASURE COAST/LAKE OKEECHOBEE AREAS WELL HAVE TIME TO WARM INTO THE L70S BEFORE THE FROPA...BUT EVEN THESE WILL BE 3-5F BLO AVG. TIGHTENING PGRAD BEHIND THE FRONT WILL ALLOW NRLY WINDS TO PERSIST OVERNIGHT...RESULTING IN A COOL AIR ADVECTION PATTERN THAT WILL ALLOW MIN TEMPS TO FALL INTO THE L/M40S W OF I-95. MARINE INFLUENCE WILL KEEP COASTAL TEMPS A FEW DEGS WARMER...GENERALLY U40S/L50S. SUNDAY... A HIGH PRESSURE RIDGE ALONG THE EASTERN SEABOARD WILL SHIFT OFFSHORE. AN EARLY MORNING COASTAL TROUGH WILL EXIST THEN DISSIPATE...GIVING WAY TO AN EASTERLY WIND FLOW IN THE AFTERNOON. THE AIR MASS WILL INITIALLY BE VERY DRY SO COASTAL RAIN CHANCES LOOK TO BE 10-15 PERCENT. WILL LEAVE SMALL POPS ALONG THE IMMEDIATE COAST THROUGH SUNDAY NIGHT. FORECAST SOUNDINGS ARE STILL SUPPORTIVE OF STRATOCUMULUS SPREADING INLAND FROM THE ATLANTIC. SO DESPITE THE MORE MILD EAST WIND FLOW...THIS CLOUDINESS SHOULD KEEP DAYTIME HIGHS A LITTLE BELOW THOSE FROM TODAY...MAINLY MID 60S NORTH AND UPPER 60S SOUTH. ONSHORE LOW LEVEL WINDS WILL KEEP OVERNIGHT LOWS MORE MILD...LOWER 50S NORTH INTERIOR AND UPPER 50S SOUTH COAST. MON INTO EARLY TUE... THIS PERIOD IS THE MAIN ITEM OF INTEREST FOR THE UPCOMING WEEK. A SHORTWAVE TROUGH IS FORECAST TO MOVE ACROSS THE SOUTHERN STATES AND SPIN UP A SURFACE LOW. THE 00Z GFS SHOWS A WEAKER SYSTEM FARTHER NORTH THAN 24 HOURS AGO. HENCE THE LOCAL LOW LEVEL WIND FIELDS ARE FORECAST TO BE WEAKER. PRECIPITABLE WATER IS STILL SHOWN TO ONLY RECOVER TO ABOUT 1.3 INCHES WITH SURFACE DEW POINTS IN THE UPPER 50S TO LOWER 60S. MOS POPS HAVE BACKED OFF TO 30-40 PERCENT FOR MON NIGHT. THE ECMWF ALSO SHOWS A WEAKER SYSTEM BUT THE POP VALUES ARE A LOT HIGHER THAN THE GFS. DO NOT WANT TO MAKE SIGNIFICANT CHANGES TO THE FORECAST JUST YET AS THE SUBTROPICAL JET CORE WILL BE NEARBY AND TEMPS ALOFT WILL BE QUITE COLD...SO EXPECT THAT THERE COULD BE ENOUGH SUPPORT FOR CONVECTION OVER THE GULF OF MEXICO TO SPREAD WELL INLAND. HAVE TRIMMED POPS BACK TO 50 PERCENT FOR MON NIGHT BUT KEPT SLIGHT CHANCE FOR THUNDER. RECENT WEAKER MODEL SOLUTIONS FOR THIS SYSTEM SUGGEST SOME SHOWER CHANCES MAY LINGER INTO TUE. REST OF WEEK... COLD FRONT IS FORECAST TO PUSH EAST OF THE AREA TUE OR TUE NIGHT... BRINGING DRYING AND WEAK COLD AIR ADVECTION. A SURFACE HIGH PRESSURE RIDGE WILL THEN BUILD FROM THE MIDWEST TO OFF THE ATLANTIC SEABOARD BY SAT...WITH A RIDGE AXIS SETTLING INTO THE LOCAL AREA. TEMPS LOOK CLOSE TO NORMAL. LATE WEEK ONSHORE FLOW SHOULD PUSH A FEW SHOWERS TOWARDS THE COAST...BUT POPS ARE TOO LOW TO MENTION. OTHERWISE IT LOOKS DRY. && .AVIATION...THRU 14/12Z SFC WINDS: THRU 13/12Z...W/SW 4-8KTS. BTWN 13/12Z-13/15Z BCMG N/NW 8-12KTS. BTWN 13/15Z-13/23Z...N/NW 12-15KTS OCNL G18-22KTS. BTWN 13/23Z-14/02Z...BCMG N 4-7KTS. VSBY/WX/CIGS: VFR ALL SITES. && .MARINE... TODAY-TONIGHT...POOR BOATING CONDITIONS AS A DRY COLD FRONT PUSHES THRU THE LCL ATLC WATERS. A MODERATE TO FRESH WRLY BREEZE THRU DAYBREAK WILL VEER TO N/NW BY MIDDAY AS THE FRONT PUSHES THRU. ROUGH SEAS AS WINDS MAKE THE SHIFT FROM AN OFFSHORE COMPONENT TO A NRLY COMPONENT THAT WILL BLOW OPPOSITE TO THE GULF STREAM CURRENT. PREVAILING WAVE HEIGHTS INCREASING FROM 2-4FT TO 4-6FT NEARSHORE... AND FROM 4-6FT TO 5-7FT OFFSHORE. STEEP WAVES WITH DOMINANT PDS BTWN 5-7SEC. CURRENT ADVISORY/CAUTION ORIENTATION LOOKS FINE FOR NOW... BUT MAY NEED TO EXPAND THE ADVISORY TO INCLUDE NEARSHORE TREASURE COAST WATERS BY LATE AFTN DUE TO THE GULF STREAM`S CLOSER PROXIMITY TO THE COAST. SUN-MON...BREEZY NORTHEAST/EAST WINDS SUN WILL VEER TO SOUTHEAST ON MON. THIS WILL KEEP CONDITIONS POOR FOR SMALL CRAFT OPERATION. MON NIGHT-WED...BREEZY SOUTH FLOW IS INDICATED FOR MON NIGHT. THIS WILL TRANSPORT MOISTURE NORTHWARD AND BRING A CHANCE OF SHOWERS AND A SLIGHT CHANCE FOR STORMS. MODELS DIFFER A BIT ON THE TUE- WED WINDS BUT OVERALL THE TREND IS FOR A WEAKER FRONTAL PASSAGE. && .PRELIMINARY POINT TEMPS/POPS... DAB 60 45 63 54 / 0 0 20 20 MCO 68 44 67 54 / 0 0 10 10 MLB 67 50 65 58 / 0 0 20 20 VRB 69 51 68 58 / 0 0 20 20 LEE 65 41 66 52 / 0 0 10 10 SFB 65 43 66 53 / 0 0 10 10 ORL 67 44 66 53 / 0 0 10 10 FPR 69 52 68 58 / 0 0 20 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR SEBASTIAN INLET TO JUPITER INLET 20-60 NM. SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM. && $$ SHORT TERM...BRAGAW LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
316 AM EST SAT FEB 13 2016 .SYNOPSIS... 08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS BROAD BUT AMPLIFIED UPPER LEVEL TROUGHING IN PLACE OVER THE EASTERN THIRD OF THE NATION. TROUGH IS ANCHORED BY A BROAD AND COLD UPPER LOW OVER EASTERN CANADA. FURTHER UPSTREAM WE FIND RIDGING THROUGH THE INTER-MOUNTAIN WEST...AND SHORTWAVE ENERGY ARRIVING OVER THE PACIFIC NORTHWEST/BRITISH COLUMBIA. BACK TO HOME...OUR REGION RESIDES WITHIN DEEP LAYER NW FLOW ON THE BACKSIDE OF THE EASTERN LONGWAVE TROUGH. SHORTWAVE ENERGY EMBEDDED WITHIN THE FLOW HAS EXITED OFF THE GA/CAROLINA COAST EARLY THIS MORNING. THIS PUSH IS DRIVING A WEAK COLD FRONT AT THE SURFACE DOWN FROM THE NORTH INTO THE FLORIDA PENINSULA. THE COLD FRONT IS CURRENTLY DROPPING SOUTH OVER THE NATURE COAST ZONES...AND SHOULD REACH THE I-4 CORRIDOR TOWARD SUNRISE...AND THEN EXIT SOUTH OF FORT MYERS BY MIDDAY. THIS IS A DRY FRONTAL PASSAGE WITH VERY LITTLE ATMOSPHERIC MOISTURE ABOVE 850MB. NARROW BAND OF LOW 2-4KFT CLOUDS LEADS THE FRONT...BUT THAT IS JUST ABOUT IT. THE FRONT WILL BE MOST MARKED BY A WIND SHIFT TO THE NORTH. LIKELY TO SEE SOME PATCHY FOG DEVELOPMENT IN THE PRE-DAWN HOURS AS WE GET SOME LOW LEVEL MOISTURE POOLING AHEAD OF THE FRONTAL BOUNDARY. THIS FOG MAY RESULT IN SOME TRICKY SPOTS FOR THE MORNING COMMUTE...BUT IT WILL NOT LAST LONG ONCE THE SUN COMES UP DUE TO THE COMBINATION OF DIURNAL MIXING...DRY AIR ADVECTION BEHIND THE FRONT. && .SHORT TERM (TODAY THROUGH SUNDAY)... AS MENTIONED IN THE SYNOPSIS...WEAK COLD FRONT WILL CROSS THE REGION THIS MORNING...AND BE SOUTH OF OUR ZONES BY THE AFTERNOON HOURS. THE AIRMASS CHANGE BEHIND THIS FRONT IS A BIT COOLER...BUT THE BIGGER CHANGE WILL BE IN THE MOISTURE AS DEWPOINTS QUICKLY DROP FROM NORTH TO SOUTH DURING THE DAY. IN FACT...AFTERNOON HIGH TEMPS WILL BE GENERALLY SEASONABLE...RANGING FROM THE LOWER 60S FAR NORTH TO THE MID/UPPER 60S CENTRAL...AND INTO THE LOWER 70S SOUTH. AFTER THE EARLY BAND OF CLOUDS...SKIES WILL BE MOSTLY SUNNY FOR THE MAJORITY OF THE DAY. THE FORECAST FOR TONIGHT IS COLDER...MAINLY DUE TO THE DRY AIR THAT WILL BE IN PLACE. HIGH PRESSURE DOES BUILD IN FROM THE NORTH...BUT THE RIDGE CENTER STAYS UP OVER THE MID-ATLANTIC STATES AND NEVER REALLY ALLOWS THE GRADIENT TO SLACKEN SUFFICIENTLY FOR IDEAL RADIATIONAL COOLING OVER OUR ZONES. AT THE VERY LEAST...THE RADIATIVE PROCESS WILL BE SLOWED...AND DOUBT MOST PLACES (OTHER THAN EXTREMELY WELL SHELTERED LOCATIONS) WILL BE ABLE TO DECOUPLE OVERNIGHT. SO...WHILE THE WIND MAY HELP KEEP MORE LOCATIONS ABOVE FREEZING...IT WILL LOWER THE POTENTIAL WIND CHILL VALUES FOR EARLY SUNDAY MORNING. DEEPEST INTO THE AIRMASS AND BEST POTENTIAL FOR RADIATIVE PROCESSES WILL BE OUR FAR NORTHERN ZONES. ALLOW INTERIOR LEVY COUNTY TO TOUCH 32 BRIEFLY AT DAWN...BUT OTHERWISE KEEP TEMPS ABOVE FREEZING. RANGE LOW TEMPS FROM THESE LOWER 30S OVER LEVY COUNTY...TO THE UPPER 30S/LOWER 40S BY THE I-4 CORRIDOR...AND GENERALLY IN THE LOWER/MID 40S FURTHER SOUTH. LOCATIONS SUCH AS SOUTHERN PINELLAS COUNTY AND THE ISLANDS/CAPES OF CHARLOTTE HARBOR WILL BE A BIT WARMER WITH NORTHEAST FLOW OFF WATER. AGAIN THOUGH...WINDS WILL NOT BE STRONG...BUT WILL NOT BE CALM EITHER. WIND CHILL VALUES ARE CURRENTLY FORECAST TO DROP INTO THE 30S LATE TONIGHT AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS COUNTIES. NORTH OF BROOKSVILLE...WIND CHILL VALUES MAY BRIEFLY DROP INTO THE 20S. HIGH PRESSURE SHIFTS OFF THE ATLANTIC SEABOARD DURING SUNDAY...SHIFTING OUR WINDS TO THE EAST. THIS FLOW WILL BRING A SLOW INCREASE IN LOW LEVEL MOISTURE BACK ACROSS THE PENINSULA FROM THE ATLANTIC. FOR OUR FORECAST...THIS MAINLY JUST MEANS A RETURN TO A SCT CUMULUS FIELD FOR THE AFTERNOON HOURS. MANY GUIDANCE MEMBERS ARE SHOWING SOME CONVERGENCE SHOWERS ALONG THE FLORIDA EAST COAST ON SUNDAY THAT WILL ATTEMPT TO MIGRATE INLAND. NOT COMPLETELY SOLD ON THIS POTENTIAL AS THE MOISTURE DEPTH IS REALLY LACKING. HOWEVER...WILL ADD MENTION OF A FEW ISOLATED SPRINKLES AFTER 18Z SUNDAY ACROSS FAR EASTERN POLK/HIGHLANDS COUNTIES. ANY SPRINKLES WILL HAVE LIMITED TO NO IMPACT ON ANY OUTDOOR ACTIVITIES. TEMPERATURES REGION-WIDE FOR SUNDAY SHOULD RECOVER FROM THE CHILLY MORNING TEMPS TO THE 60S FOR THE AFTERNOON. && .LONG TERM (MONDAY THROUGH NEXT FRIDAY)... AN UPPER TROUGH INITIALLY FROM MANITOBA TO THE WESTERN GULF OF MEXICO WILL SHARPEN AND SHIFT INTO THE EASTERN COASTAL STATES TUE...AS A SURFACE LOW FORMS ON THE GULF COAST AND TRACKS TO THE MID- ATLANTIC STATES. THE LOW TRAILS A COLD FRONT INTO THE EASTERN GULF MON NIGHT AND ACROSS FL TUE. AS THE UPPER TROUGH AND SURFACE LOW MOVE EAST A RIDGE OF HIGH PRESSURE ALONG THEE EASTERN SEABOARD SLIDES EAST. AS IT DOES THE LOW LEVEL FLOW VEERS FROM EASTERLY TO SOUTHERLY BY MON NIGHT...HELPING TO MOISTEN THE ATMOSPHERE ALTHOUGH MODELS ONLY INCREASE PWAT VALUES INTO THE 1 TO 1.5 INCH RANGE. BUT THIS WILL BE ENOUGH ALONG WITH THE UPPER TROUGH AND COLD FRONT FOR SHOWERS AND THUNDERSTORMS...STARTING MON AFTERNOON THEN ENDING TUE AS THE FRONT EXITS TO THE EAST. THE GREATEST ODDS OF SHOWERS AND STORMS WILL BE MON NIGHT AND EARLY TUE MORNING. CURRENTLY THE BEST DYNAMICS FOR SEVERE STORMS APPEAR TO STAY NORTH OF THE AREA. FOR WED THROUGH FRI - THE UPPER TROUGH SLOWLY SLIPS OFFSHORE AS AN UPPER RIDGE BUILDS NORTHWARD OVER THE WESTERN STATES THEN MOVES ACROSS THE EASTERN STATES AS IT FLATTENS SOME. SURFACE HIGH PRESSURE BUILDS IN OVER THE MID-MISSISSIPPI VALLEY THEN MIGRATES TO THE ATLANTIC COAST WATERS. A DRY AND STABLE AIRMASS WILL BE IN PLACE TEMPERATURES RUNNING CLOSE TO SEASONAL. WINDS REMAIN RATHER MODEST...ONLY BRIEFLY APPROACHING 20 KNOTS ON THE GULF MON AND TUE AHEAD OF THE FRONT. && .AVIATION... A NARROW BAND OF BKN MVFR CIGS WILL CONTINUE TO DROP SOUTH THROUGH THE REGION EARLY THIS MORNING IN ADVANCE OF A WEAK COLD FRONT. THIS FRONT WILL CROSS THE TAMPA BAY AREA AROUND SUNRISE...AND THEN PASS SOUTH OF KFMY/KRSW LATER IN THE MORNING. WINDS SHIFT NORTHERLY BEHIND THIS FRONT...AND THE NORTHEASTERLY TONIGHT. A BRIEF PERIOD OF MVFR CIGS IS POSSIBLE AHEAD OF THE FRONT...WITH PATCHY FOG ALSO DEVELOPING BEFORE DAWN. A PERIOD OF IFR/MVFR VIS IS ALSO POSSIBLE THROUGH 13Z...WITH KLAL/KPGD MOST LIKELY TO SEE THE VIS RESTRICTIONS. PREVAILING VFR CONDITIONS ARE THEN FORECAST THROUGH 12Z SUNDAY. && .MARINE... A WEAK COLD FRONT DROPS SOUTHWARD THROUGH THE FORECAST WATERS THIS MORNING. WINDS WILL SHIFT TO THE NORTH BEHIND THIS FRONT REACHING CAUTIONARY LEVELS AT TIMES...OUTSIDE OF THE BAYS AND HARBORS. HIGH PRESSURE MOVING NORTH OF THE REGION TONIGHT WILL SHIFT WINDS TO THE NORTHEAST...WITH THE POTENTIAL FOR A MORE WIDESPREAD PERIOD OF CAUTIONARY LEVEL WINDS. WINDS SHIFT EAST ON SUNDAY AND DIMINISH BELOW HEADLINE CRITERIA BY THE AFTERNOON HOURS. THE NEXT COLD FRONT CROSSES THE EASTERN GULF OF MEXICO MONDAY NIGHT AND EARLY TUESDAY. WINDS CURRENTLY ARE NOT EXPECTED TO REACH HEADLINE CRITERIA BEHIND THIS FRONT THROUGH THE DAYLIGHT HOURS OF WEDNESDAY. && .FIRE WEATHER... A MUCH DRIER AIRMASS WILL ARRIVE ON NORTHERLY WINDS TODAY IN THE WAKE OF A WEAK COLD FRONT. WITH THE DRY AIR...RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP BELOW 35 PERCENT FOR SEVERAL HOURS THIS AFTERNOON AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS COUNTIES. NORTH OF THE I-4 CORRIDOR...RELATIVE HUMIDITY IS EXPECTED TO DROP INTO THE 20S FOR A TIME. ALTHOUGH IT WILL BE DRY...RED FLAG CONDITIONS ARE NOT FORECAST AS ERC VALUES REMAIN AT OR BELOW 25...AND WINDS WILL STAY BELOW CRITICAL LEVELS. LOW LEVEL MOISTURE BEGINS TO INCREASE DURING SUNDAY ON LIGHT EASTERLY FLOW...AND THIS MOISTURE RETURN CONTINUES INTO MONDAY. AFTER THIS AFTERNOON...CRITICAL LEVELS OF RELATIVE HUMIDITY ARE NOT EXPECTED THROUGH THE EARLY PORTION OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... TPA 65 43 68 54 / 0 0 0 0 FMY 73 47 72 55 / 0 0 0 0 GIF 69 43 66 53 / 0 0 10 10 SRQ 67 44 68 54 / 0 0 0 0 BKV 65 38 67 49 / 0 0 0 0 SPG 65 48 67 56 / 0 0 0 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR COASTAL CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL SARASOTA. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...MROCZKA LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1128 PM CST FRI FEB 12 2016 .UPDATE... ISSUED AT 859 PM CST FRI FEB 12 2016 Skies have become clear this evening and should remain that way the rest of the night. Any additional clouds will be very late tonight or early tomorrow morning and be cirrus clouds. Winds remain gusty and am expecting this to continue as forecast as well. Gusty winds will keep air mixed, but dewpoints are in the single digits over most of the area, so still think temps by morning will be in the single digits to just below zero in the northwest. Only change needed is to adjust cloud cover to better reflect current conditions. Update will be out shortly. && .SHORT TERM...(Tonight) ISSUED AT 255 PM CST FRI FEB 12 2016 A weak clipper system will exit southeast of central IL late this afternoon, with its diminishing area of very light snow/flurries se of the IL river ending soon, with best light snow chances east of IL over central IN. MVFR clouds already scattering nw of the IL river like at PIA and HRRR model handling this clearing well. These clouds to decrease se of the IL river during late afternoon/early evening, and over southeast IL by mid evening. Brisk NW winds of 15-25 mph and gusts to 30 mph will gradually diminish during the night, reaching 5-15 mph later tonight. Strong 1046 mb polar high pressure west of Lake Winnipeg Canada to settle se into MN/IA by sunrise Sat and bring a frigid night to the region. Lows by early Saturday morning range from around zero north of I-72 to 4-8F in southeast IL from I-70 southeast. Wind chills by dawn will range from 5-15 below zero with a few spots from I-74 north dipping to 15-17 below zero like at Bloomington, Galesburg and Champaign. Will hold off on a wind chill advisory overnight into mid Sat morning, but will issue SPS to address these bitter cold wind chills especially in our northern CWA. .LONG TERM...(Saturday through Friday) ISSUED AT 255 PM CST FRI FEB 12 2016 Very cold conditions expected to start the day Saturday across central and southeast Illinois as Arctic high pressure builds across the area. The relatively slight pressure gradient that will accompany the surface high should keep Wind Chill values warmer than advisory criteria for the most part, but high temperatures should only top out in the teens. Beyond the initially cold conditions, our attention turns to an approaching clipper system, which is likely to be the most significant weather system to impact the area over the next week. This clipper has trended faster in recent model runs, with snow now expected to start breaking locally after midnight Saturday night/Sunday morning. The system will be pushing into a very dry airmass which should limit the snow accumulation to some degree. However, fairly strong isentropic ascent and mixing ratios of 2-3 G/KG over at least a 12 hour period should be able to produce 2"=4" snow totals. In fact, would not be surprised if we need to boost accumulations further once the exact track of the system is more clear (it has trended s bit south in the latest runs). One other thing that will need to be monitored is that the moisture depth is progged to be rather shallow during the period of potential snow. This fact is also a reason to limit snow accumulations for now, and we also need to monitor the threat for freezing drizzle due to a potential lack of ice crystals. The faster trend of the clipper system should now have Monday ending up dry. Another weak clipper system may impact the area Tuesday into Tuesday night, but it does not appear significant at this time. After that, the next chance for precipitation should not occur before the end of the week. However, model agreement in the details of the late week system is weak at best. Temperatures should gradually be trending warmer next week, with well above normal temperatures likely by the end of the week (near 50 degrees for highs). If these trends hold, the late week system, if/when it impacts the area, should be a rain producer. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) ISSUED AT 1128 PM CST FRI FEB 12 2016 VFR conditions will continue at all TAF sites next 24hrs. Clear skies will continue overnight and through the afternoon. Models bring in some high cirrus late tomorrow afternoon/early evening in advance of the next weather system. The cirrus will thicken during the evening hours, followed by some mid clouds around 12kft reaching SPI and DEC later in the evening. Winds still a tad gusty but not too bad so will not have any gusts in this forecast. Winds will become lighter through the morning hours and then become light and variable during the early evening. Later in the evening winds will increase in speed some, but only reaching around 4-5kts. Wind direction will continue to be northwest through the night but then switch so southeast during the evening after the ridge goes by. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Auten SHORT TERM...07 LONG TERM...BAK AVIATION...Auten
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1241 AM EST SAT FEB 13 2016 .SYNOPSIS... ISSUED AT 1235 AM EST SAT FEB 13 2016 THIS WEEKEND WILL FEATURE COLD TEMPERATURES WITH HIGHS INTO THE MID TEENS TODAY AND NEAR 20 ON SUNDAY. LOWS TONIGHT WILL LIKELY FALL TO NEAR ZERO DEGREES. LAKE EFFECT SNOW SHOWERS AND AREAS OF BLOWING SNOW WILL CONTINUE TO IMPACT AREAS ACROSS FAR NORTHERN INDIANA AND SOUTHWEST LOWER MICHIGAN TODAY...WITH LIGHTER FLURRIES AND SNOW SHOWERS POSSIBLE ELSEWHERE. HIGH PRESSURE BRIEFLY BUILDS IN FOR TONIGHT AND SUNDAY MORNING BEFORE SNOW CHANCES RETURN LATER SUNDAY INTO EARLY MONDAY. TEMPERATURES WILL MODERATE CLOSER TO NORMAL NEXT WEEK WITH SEVERAL CHANCES FOR LIGHT PRECIPITATION. && .UPDATE... ISSUED AT 734 PM EST FRI FEB 12 2016 POST FNTL SHSN WITHIN EMERGING ARCTIC AIRMASS QUITE INTENSE IN SPOTS YET THIS EVENING BUT WILL CONT TO DIMINISH AS UNSTABLE SFC BASED LAPSE RATES DECAY W/SUNSET. REGARDLESS GROWING QUITE CONCERNED W/UPSTREAM LAKE RESPONSE WITHIN EVOLVING/INTENSIFYING LL THERMAL TROUGH. GENERAL CONSOLIDATION IN BANDING NOTED OVR THE LAST 3 HOURS ALG A MUSKEGON TO ALLEGAN LINE...MIMICKING RECENT RAP MODEL INDICATIONS AS LL FLW VEERS CONSIDERABLY W/UPSTREAM EXTENT. THIS PRIMARY PLUME XPCD/MODELED TO INTENSIFY AS IT COMES SOUTH THROUGH LT EVENING BFR LOCKING IN WITHIN ROUGHLY ALG A SOUTH HAVEN...CASSOPOLIS...ELKHART...WARSAW LINE. BASED ON OBSVD RADAR TRENDS...SUSPECT NR 1" PER HOUR PEAK SNOWFALL RATES WHICH MAY REQUIRE SOME FORM OF HEADLINE ADJUSTMENT. WILL ATTM FOLLOW EVOLUTION OF THIS BAND THROUGH MID EVENING AND MAKE A DECISION IF NEEDED WELL BFR 11 PM. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 306 PM EST FRI FEB 12 2016 CDFNT MOVG RAPIDLY E-SE ACROSS THE CWA THIS AFTN ACCOMPANIED BY A BAND OF SNOW SHOWERS. LAKE EFFECT SNOW SHOWERS DVLPG BEHIND THE FRONT SHOULD GRDLY INTENSIFY THIS EVE AS CAA CONTS AND WINDS VEER FROM AROUND 300 DEGREES TO 340 DEGREES AS A SECONDARY CDFNT CURRENTLY OVER NRN LWR MI MOVES THROUGH OUR AREA. INVERSION BASE FORECAST TO PEAK LATE THIS EVE AROUND 6500FT WITH SIGNIFICANT LAKE INDUCED INSTABILITY (0-2KM THETA-E LAPSE RATES OVER THE LAKE AROUND -2.5C/KM). CONVECTION ALLOWING MODELS SUGGEST A DOMINANT BAND OR TWO WILL SET UP AROUND THIS TIME IMPACTING NORTHWEST PORTION OF OUR CWA. HWVR, THESE OPTIMAL CONDITIONS FOR LES SHOULD BE SHORT LIVED AS INVERSION FCST TO LOWER/LAKE INDUCED INSTABILITY DECREASE LATE TONIGHT AND THROUGH THE DAY SATURDAY. DGZ WILL ALSO BE VERY LOW GIVEN ARCTIC AIRMASS MOVG IN WHICH SHOULD LIMIT ACCUMS BLO WHAT OTRWS MIGHT BE EXPECTED. ONLY MINOR CHANGE MADE TO PREVIOUS FCST ACCUMS WITH TOTALS TONIGHT AND SATURDAY EXPECTED TO BE IN THE 3-6" RANGE IN THE ADVISORY AREA WITH 1-3" IN COUNTIES SURROUNDING ADVISORY AND <1" OVER THE REST OF THE CWA. LOCALLY HIGHER AMOUNTS PSBL IF DOMINANT BAND PERSISTS OVER ANY GIVEN AREA VERY LONG THIS EVENING. BOUNDARY LAYER WINDS FCST 15-25KT TONIGHT WHICH SHOULD CAUSE CONSIDERABLE BLOWING DRIFTING OF THE POWDERY LES, MAINLY IN THE NW ADVISORY AREA. LITTLE CHANGE MADE TO TEMPS WITH LOWS TONIGHT IN THE 0-5 RANGE NE AND SW WHERE SOME PARTIAL CLEARING EXPECTED AND 5-10 UNDER THE LAKE EFFECT CLOUD PLUME OVER MOST OF THE REST OF THE CWA, WITH HIGHS SATURDAY ONLY 12-16. MINIMUM WIND CHILLS TONIGHT AND SATURDAY MORNING EXPECTED TO BE IN THE -5 TO -15 RANGE. && .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 306 PM EST FRI FEB 12 2016 LAKE EFFECT SNOW WILL TAPER OFF SATURDAY EVENING AS LOW LEVEL RIDGE AXIS SHIFTS OVERHEAD AND INVERSION HEIGHTS LOWER. DGZ REMAINS ACTIVE IN THE 00-06Z TIMEFRAME SO SOME LIGHT FLURRIES/SNOW SHOWERS EXPECTED BUT ANY ADDITIONAL ACCUMULATION WILL BE VERY LIGHT. MAIN STORY FOR SATURDAY NIGHT WILL BE VERY COLD TEMPS. LIGHT WINDS...PARTIALLY CLEAR SKIES...AND FRESH SNOW WILL SUPPORT GOOD RADIATIONAL COOLING POTENTIAL IN SPOTS. GRADIENT WIND/WAA AND CLOUDS BEGIN TO INCREASE TOWARD 12Z BUT SHOULD STILL BE ENOUGH TIME FOR TEMPS TO DROP. KEPT CLOSE TO INHERITED FORECAST...WHICH IS ON THE COLD SIDE OF GUIDANCE...WITH LOWS AROUND ZERO. WILL LIKELY BE A HIGH DEGREE OF VARIANCE IN FINAL NUMBERS THOUGH...DEPENDING ON EXACT CLOUD TRENDS. CHANCE FOR LIGHT SNOW THEN QUICKLY RETURNS LATE SUNDAY AS NEXT SHORTWAVE ROTATES THROUGH THE REGION. CONFLUENT FLOW OVER THE EASTERN CONUS WILL INCREASINGLY SHEAR OUT AND WEAKEN THIS WAVE. CVA BECOMES NEGLIGIBLE BY SUNDAY NIGHT WITH JUST SOME BROAD/WEAK 280- 285K ISENTROPIC ASCENT. DO SEE A DECENT MOISTURE SURGE THOUGH WITH MIXING RATIOS OVER 2 G/KG. GIVEN STEADY...ALBEIT WEAK...ASCENT AND POTENTIAL FOR HIGHER THAN CLIMO SNOW RATIOS...COULD CHURN OUT 1-2" BY LATE MONDAY MORNING. BEST CHANCES FOR HIGHER AMOUNTS WILL BE IN OUR SOUTHWEST WHERE BETTER MOISTURE AND FORCING RESIDE. AFTER A BRIEF BREAK MONDAY NIGHT...THERE IS ANOTHER CHANCE FOR SNOW TUESDAY/TUESDAY NIGHT AS POTENT NORTHERN STREAM SHORTWAVE DIVES SOUTHEAST AND STRENGTHENS EAST COAST LOW. MODELS HAVE BEEN KEEPING PRECIP SHIELD OF PRIMARY LOW JUST EAST OF OUR CWA BUT CONTINUE TO STRUGGLE IMMENSELY WITH EXACT TRACK OF SECONDARY VORT MAX. CONFIDENCE IN SNOW CHANCES REMAINS LOW AT THIS POINT WITH PARENT JET ENERGY STILL WELL OUT OVER THE DATA-SPARSE NORTH PACIFIC. WILL CONTINUE TO WATCH THIS PERIOD AND ADJUST AS MODELS GET A BETTER HANDLE ON SITUATION. SOME MINOR LAKE EFFECT THEN POSSIBLE WEDNESDAY WITH MUCH WARMER TEMPS (AND POTENTIAL FOR RAIN) STILL EXPECTED BY THE END OF THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1235 AM EST SAT FEB 13 2016 NW FLOW LAKE EFFECT EVENT WILL CONTINUE TO PROVIDE VARIABLE FLIGHT CONDITIONS AT KSBN THROUGH THE MORNING (VIS MAINLY IFR WITH TIMES OF MVFR/LIFR)...WITH GRADUAL IMPROVEMENT ANTICIPATED THIS AFTERNOON AS FLOW BACKS ALLOWING FOR DRY AIR ENTRAINMENT INTO SHRINKING BOUNDARY LAYER. KFWA LIKELY TO GET CLIPPED BY PRIMARY LAKE EFFECT BAND THROUGH 07Z WITH MVFR/IFR CONDITIONS ANTICIPATED. IMPROVEMENT TO VFR/LIGHTER WINDS THEN EXPECTED FOR THE REMAINDER OF THE NIGHT AT KFWA...WITH SCT SHSN/FLURRIES FILLING BACK IN DURING THE DAY. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR INZ003>005. MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ077>079. OH...NONE. LM...HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ043-046. GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ043-046. && $$ UPDATE...T SYNOPSIS...STEINWEDEL SHORT TERM...JT LONG TERM...AGD AVIATION...STEINWEDEL VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
405 AM CST SAT FEB 13 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 348 AM CST SAT FEB 13 2016 Areal expansion of stratus will be the main forecast challenge heading through the morning hours, and should have a significant impact of temperature trends through the day across the far north. Some southeastward development of freezing fog is not out of the question this morning, however the probability for freezing drizzle in these areas of stratus is not looking quite as probable at this time. A large temperatures gradient is expected this afternoon in excess of 30 degrees from the Elkhart area which should be in the 60s...to Hays where highs will not likely exceed the 30s. A shortwave now moving into the northern Rockies will affect the northern and central high plains region by the overnight, having very little impact on western Kansas other than pushing a cold front/wind shift across the region before Sunday morning. .LONG TERM...(Sunday THROUGH Friday) ISSUED AT 348 AM CST SAT FEB 13 2016 Models have been consistent with a followup/secondary vort lobe rotating through a bit farther south about 24 hours later which will improve chances for rain or snow late Sunday night into very early Monday morning. The remainder of the forecast period will see rising thicknesses and more northwest flow aloft, resulting in a warming trend through at least Thursday. Could not rule out another 80 degree reading by Thursday as a warm dry downslope pattern once again develops and possibly critical fire weather conditions. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Saturday NIGHT) ISSUED AT 1209 AM CST SAT FEB 13 2016 The HRRR model develops/spreads near IFR stratus farther south across the area over the next few hours and maintains it through the mid to late moring hours. Freezing fog is not a given at any of the terminals this morning, as the HRRR indicates the best signal on the higher terrain in northeast CO, however we will monitor trend going foreward incase it develops farther east. && .PRELIMINARY POINT TEMPS/POPS... DDC 45 30 56 31 / 0 0 0 10 GCK 52 29 57 30 / 10 0 0 10 EHA 65 36 58 32 / 0 0 0 10 LBL 57 32 58 30 / 0 0 0 10 HYS 36 27 51 31 / 10 0 10 20 P28 43 31 58 33 / 0 10 0 10 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Russell
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1226 AM CST SAT FEB 13 2016 ...UPDATED AVIATION SECTION... .SYNOPSIS... ISSUED AT 213 PM CST FRI FEB 12 2016 An upper level ridge of high pressure is located over the Rockies with a long wave trough over the east coast. This places the Central High Plains under northwest flow aloft. High to mid levels of the atmosphere over western Kansas are fairly dry leaving only a few high clouds visible across western Nebraska and northwest Kansas. Some of these clouds may make it into portions of west and west central Kansas this afternoon. As we head to the surface, low levels of the atmosphere are saturated across portions of central and western Kansas leading to a deck of low stratus extending north and east of a line from Colby to Kingman. This deck of clouds is slowly shifting southeast, however, these clouds are expected to dissipate over the next couple of hours. An area of low pressure with associated stationary front is sprawled out across eastern Colorado with a dome of high pressure filtering into the Northern Plains. This will lead to winds backing from the northeast this afternoon to more of an easterly direction this evening. && .SHORT TERM...(THIS EVENING THROUGH Saturday) ISSUED AT 1245 PM CST FRI FEB 12 2016 Low clouds are expected to form once again over north, west central, and north central Kansas tonight with mostly clear skies expected elsewhere. This deck of clouds may be thick enough for light freezing drizzle to fall, mainly north of Highway 96. Winds look to back form an easterly direction this evening, then shifting southeast by midnight. Low clouds are expected to extend into Oklahoma by sunrise tomorrow but then slowly dissipate by mid afternoon like we saw today. Winds take more of a southerly direction with an increase in speed tomorrow as the area of low pressure mentioned in the synopsis intensifies and slides into southeastern Colorado. The dome of high pressure will continue to build across Northern and Central Plains. As for temperatures, lows tonight look to range from the upper teens across north central Kansas to upper 20s across far southwestern Kansas. Highs tomorrow are anticipated to range from the mid 30s across north central Kansas to mid 60s across far southwestern Kansas. .LONG TERM...(Saturday NIGHT THROUGH Friday) ISSUED AT 213 PM CST FRI FEB 12 2016 The upper level ridge in mentioned in the short term gets pushed south Friday night into the weekend as a shortwave moves into the Intermountain West Saturday then Northern Plains Saturday night into Sunday. Cloudiness will increase in coverage as this system moves into the Plains Saturday night with decreasing cloudiness on Sunday. No precipitation is expected with this system due to lake of moisture. This system will also help push a cold front through the area shifting winds to more of a northerly direction. A second shortwave is progged to move through the area Sunday night into Monday once again increasing cloud cover across western Kansas. There may be enough low to mid level moisture to squeeze out some light rain or snow Sunday night but most likely we will stay dry. An upper level ridge builds into the western Untied States early into the mid part of next week. This will allow warmer temperatures to build back into the area but with the sacrifice of no measurable precipitation expected. Models then suggest another system moving into the area late next week but that being so far out it is hard to tell the exact track. As for temperatures, highs in the 50s are expected Sunday, then reaching to around 60 degrees Monday. Lows Saturday night will start out around 30 degrees, with lower 30s Sunday night and mid 30s Monday night. A warming trend continues through the week with highs starting out Tuesday ranging from upper 50s north to mid 60s south ending Thursday with highs ranging from the upper 60s north to around 80 degrees across far southwestern Kansas. Lows during this time frame start out in the mid 50s Tuesday night ranging from the upper 30s to mid 40s Thursday night. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Saturday NIGHT) ISSUED AT 1209 AM CST SAT FEB 13 2016 The HRRR model develops/spreads near IFR stratus farther south across the area over the next few hours and maintains it through the mid to late moring hours. Freezing fog is not a given at any of the terminals this morning, as the HRRR indicates the best signal on the higher terrain in northeast CO, however we will monitor trend going foreward incase it develops farther east. && .PRELIMINARY POINT TEMPS/POPS... DDC 45 30 56 32 / 0 0 10 20 GCK 52 30 57 31 / 10 0 10 20 EHA 64 37 58 33 / 0 0 10 10 LBL 57 32 58 32 / 0 0 10 10 HYS 36 27 52 31 / 10 0 10 20 P28 43 32 58 33 / 0 10 10 20 && .DDC Watches/Warnings/Advisories...NONE. && $$ SYNOPSIS...Hovorka_42 SHORT TERM...Hovorka_42 LONG TERM...Hovorka_42 AVIATION...Russell
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1240 AM EST SAT FEB 13 2016 .SYNOPSIS...ARCTIC HIGH PRESSURE WILL BUILD INTO CENTRAL NC TODAY AND SUNDAY. AN AREA OF LOW PRESSURE WILL APPROACH FROM THE WEST ON MONDAY AND CROSS THE REGION MONDAY NIGHT AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 940 PM FRIDAY... STARTING TO FINALLY SEE BETTER WEST TO EAST CLEARING OF MOISTURE AROUND 6000-7000 FT AS A JET ON THE BACK SIDE OF THE UPPER TROUGH APPROACHES AND NORTHWEST FLOW STRENGTHENS. LOW-LEVEL MOISTURE IS STILL MORE PREVALENT ON THE COASTAL PLAIN WHERE SOME SUB-1000 FT STRATUS IS LINGERING. A PERIOD OF PATCHY FOG MAY DEVELOP IN THE SOUTHERN COASTAL PLAIN AS THE HIGHER LEVEL CLOUDS CLEARING (HINTED AT BY SREF PROBS AND KFAY/KGSB RAP SOUNDINGS)...BUT IT WOULD LIKELY BE BRIEF...PRIOR TO 06Z...WITH A NORTHWEST WIND AND COLD ADVECTION FORECAST TO SLOWLY STRENGTHEN AFTER MIDNIGHT. OTHERWISE...WHILE WE MAY SEE A SOME PATCHES OF STRATOCU DRIFT ACROSS THE AREA GIVEN ALL THE MOISTURE BANKED UPSTREAM OF THE MOUNTAINS...CLEARING SKIES AND COLD ADVECTION WILL PUSH LOWS INTO THE LOWER 20S NORTH AND WEST TO UPPER 20S SOUTH AND EAST. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 300 PM FRIDAY... AS EAST COAST TROUGH TRIES TO PULL OFF THE COAST...VERY STRONG COLD AIR ADVECTION WILL ENSUE BEHIND THE EXITING COASTAL SYSTEM. WITH VERY STRONG PRESSURE GRADIENT ACROSS THE AREA...COLD TEMPERATURES AND STRONG WINDS WILL BE THE FORECAST PROBLEM OF THE DAY. EXPECT WINDS TO REMAIN SUSTAINED OUT OF THE NORTH OR NORTHWEST AT 10-15 KTS WITH GUSTS OF 25-30 KTS FOR MUCH OF THE DAYLIGHT HOURS. AFTER SUNSET GUSTS WILL SUBSIDE. HIGH TEMPERATURES ONLY IN THE LOW TO MID 30S AND WITH WIND CHILL VALUES IN THE UPPER 10S TO LOW 20S FOR MUCH OF THE DAY. AS AN ASIDE...WITH THE COLD BUT ALSO DRY AIRMASS IN PLACE...MIN RH VALUES WILL DIP DOWN INTO THE LOW 20S. COMBINE THESE VALUES WITH THE HIGHER WINDS AND THERE WILL BE A SMALL INCREASE IN FIRE DANGER SATURDAY IN OUR SOUTHERN COUNTIES THAT MAY SQUEAK INTO THE LOWER 40S. SATURDAY NIGHT WILL SEE THE GUSTS SLACK OFF BUT SUSTAINED WINDS TO REMAIN UP IN THE 5 TO 10 KT RANGE KEEP THINGS MIXED A LITTLE. COMBINE THIS WITH VERY COLD EXPECTED LOW TEMPERATURES IN THE LOW TO MID TEENS...WIND CHILL VALUES SATURDAY NIGHT WILL RESIDE IN THE 5-10 DEGREE RANGE. PREPARATIONS SHOULD BE MADE NOW TO PROTECT ANYTHING SUSCEPTIBLE TO THE COLD WIND CHILLS...ESPECIALLY PETS. SOME CLOUDS WILL BEGIN TO APPROACH THE AREA LATE SATURDAY NIGHT INTO SUNDAY MORNING FROM THE WEST IN ADVANCE OF THE NEXT STORM SYSTEM. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 315 PM FRIDAY... ...STORM SYSTEM LIKELY TO BRING WINTRY WEATHER THREAT SUN NIGHT/MON FOLLOWED BY HEAVY RAIN THREAT AND A FEW STORMS MON NIGHT/TUE... SUNDAY: CONTINUED CHILLY WITH THE ARCTIC HIGH PRESSURE EXTENDING FROM THE ERN GREAT LAKES DOWN THROUGH NC. WILL HAVE INCREASING CLOUDS AHEAD OF THE APPROACHING STORM... AS OUR MID LEVEL FLOW SHIFTS FROM FAST NORTHWESTERLY TO WEST-SOUTHWEST... A FUNCTION OF PACIFIC NORTHWEST ENERGY DIVING INTO AN INITIALLY FLAT/BROAD CENTRAL CONUS TROUGH CAUSING ITS AMPLIFICATION. STATISTICAL GUIDANCE STILL SUPPORTS HIGHS FROM 29 NE TO 35 SW. -GIH SUN NIGHT THROUGH TUE: OVERVIEW: CONFIDENCE IS BEGINNING TO INCREASE REGARDING THE TIMING... MOST PROBABLE PRECIP TYPE PATTERN... AND PRIMARY WEATHER THREATS FOR THE INCOMING SYSTEM. LATEST GUIDANCE SHOWS A BIT QUICKER ONSET... WITH PRECIP ARRIVING IN THE NRN/WRN CWA SUN NIGHT... AS WELL AS A SLIGHTLY EARLIER DEPARTURE ON TUE. LONGWAVE TROUGHING WILL CONTINUE TO AMPLIFY ALONG THE MISS VALLEY AS NRN STREAM ENERGY DROPS INTO ITS BASE OVER THE GULF STATES... CULMINATING IN A NARROW DEEP SHORTWAVE TROUGH TAKING ON A POSITIVE TILT AS IT SWINGS ENE INTO THE CAROLINAS. AT THE SURFACE... THE POLAR HIGH SITUATED OVER THE NORTHEAST AND MIDATLANTIC STATES SUN NIGHT CONTINUES TO PUSH STEADILY NORTHEAST AND OFFSHORE THROUGH MON... WHILE A COASTAL FRONT FORMS ALONG THE CAROLINA COAST EXTENDING BACK TO DEVELOPING LOW PRESSURE OVER THE CENTRAL GULF STATES. THIS LOW THEN TRACKS EAST THEN NE THROUGH WRN NC MON NIGHT/TUE MORNING BEFORE MOVING QUICKLY INTO THE NORTHEAST STATES... WITH A TRAILING FRONT SWEEPING THROUGH CENTRAL/ERN NC BY EARLY TUE AFTERNOON. PRECIPITATION CHANCES: THE INITIAL PROCESSES TO FORCE ASCENT SUNDAY NIGHT INTO EARLY MONDAY INCLUDING DPVA AND MOIST ISENTROPIC UPGLIDE ARE RATHER WEAK AND FOCUSED PRIMARILY ON WRN AND NRN PORTIONS OF CENTRAL NC. WILL TREND POPS UP TO LIKELY NW AND RETAIN HIGH CHANCES ACROSS THE SOUTH AND EAST SUN NIGHT INTO MON MORNING... WITH QPF FAIRLY LIGHT... UNDER A QUARTER INCH MAINLY IN THE NW. BUT THIS CHANGES QUICKLY WITH THE ADDITION OF STRONG UPPER DIVERGENCE (DUE TO IDEALLY JUXTAPOSED POLAR AND SUBTROPICAL JETS) AND VIGOROUS LOW LEVEL MOISTURE TRANSPORT EAST OF THE LOW. WILL RAMP UP POPS FURTHER TO CATEGORICAL WEST/LIKELY EAST LATE MON... THEN TO CATEGORICAL EVERYWHERE MON NIGHT THROUGH TUE MORNING... ENDING SW TO NE TUE AFTERNOON. PTYPES: USING THE TOP-DOWN METHODOLOGY WITH CONSIDERATION OF THE INITIALLY VERY COLD/DENSE NATURE OF THE SURFACE AIR MASS... THE INITIAL COLD AIR ALOFT GIVING WAY TO A WARM NOSE... AND THE STRONG LOW LEVEL WARM ADVECTION APT TO DISLODGE THIS SURFACE AIR MASS GRADUALLY FROM SE TO NW MON EVENING... EXPECT THIS TO START AS MOSTLY LIGHT SNOW WITH PERHAPS PATCHY LIGHT SLEET SUN NIGHT ACROSS THE NRN AND WRN CWA... FOLLOWED BY A SLOW STEADY TRANSITION FROM SSE TO NNW TO FREEZING RAIN/SLEET THEN TO ALL RAIN... WITH THE FAR NW COUNTIES INCLUDING THE TRIAD THE LAST TO SEE AN END TO THE WINTRY PRECIP MON EVENING. TENTATIVE ACCUMULATIONS ARE UP TO ONE TO TWO HUNDREDTHS OF AN INCH OF ICING (TRACE AMOUNTS) FOR MUCH OF THE CWA... AND SNOW TOTALS OF 1-3" NW QUARTER WITH AN INCH OR LESS ELSEWHERE... ALL OF WHICH SHOULD BE QUICKLY SWEPT AWAY BY MODERATE TO POTENTIALLY HEAVY RAINFALL LATE MON NIGHT INTO TUE MORNING. RAINFALL TOTALS AND STORM POTENTIAL: AT THIS TIME STORM TOTAL LIQUID QPF IS EXPECTED TO BE 1-2" WITH LOCALLY HIGHER AMOUNTS POSSIBLE... GIVEN THE HIGH WATER CONTENT AND STRONG LIFT MON NIGHT/TUE MORNING. BASED ON THE ANTECEDENT CONDITIONS AND SEVERAL RIVERS AND CREEKS RUNNING HIGH... A FLOOD WATCH MAY BE NEEDED FOR SOME PORTION OF THE AREA. ALSO... WHILE LAPSE RATES ARE UNLIKELY TO BE VERY IMPRESSIVE... THE STRONG AND FOCUSED LIFT POSSIBLE WITH THIS SYSTEM AND WARMING LOW LEVELS ESPECIALLY IN THE SANDHILLS AND COASTAL PLAIN MAY SUPPORT A FEW LIGHTNING STRIKES ON TUE. TEMPS: EXPECT LOWS SUN NIGHT OF 22-26. TEMPS SHOULD SLOWLY RISE MON THROUGH MON NIGHT... REACHING THE LOW 30S NW TO LOW 40S SE LATE MON... RISING TO THE MID 30S NW TO MID 40S SE MON NIGHT... AND PEAKING AT 48-56 TUE PRIOR TO FRONTAL PASSAGE. WED THROUGH FRI: WE MAY SEE A PERTURBATION SWING THROUGH THE LONGWAVE ERN TROUGH BASE ACROSS VA ON WED... BUT MODELS VARY ON THE STRENGTH AND LATITUDE OF ANY SUCH WAVE... AND REGARDLESS THE MOISTURE WILL BE LIMITED YIELDING NO IMPACTS ON CENTRAL NC OTHER THAN SOME CLOUDS ACROSS THE NORTH. OTHERWISE... THIS PERIOD WILL FEATURE A TRANSITION AWAY FROM WRN RIDGE/ERN TROUGH OVER THE CONUS... AS FLAT RIDGING BUILDS OVER THE GULF/SOUTHEAST STATES FROM THE WEST... WITH A NET RESULT OF DRY WEATHER AND NEAR TO SLIGHTLY ABOVE NORMAL TEMPS FOR CENTRAL NC. -GIH && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 1240 AM SATURDAY A LAYER OF SCATTERED-BROKEN STRATOCU WILL LINGER ACROSS THE NORTHERN COUNTIES THROUGH 10Z...THEN GRADUALLY DIMINISH. THE LEADING EDGE OF AN ARCTIC AIRMASS WILL OVERSPREAD CENTRAL NC THROUGH 11Z. SFC WINDS WILL GUSTS BETWEEN 20-25KTS WITH THE PASSAGE OF THE BOUNDARY. AFTER 11Z...EXPECT VFR CONDITIONS WITH FEW-SCATTERED STRATOCU. SFC WINDS WILL BE BRISK WITH GUSTS 22-27KTS HIGHLY PROBABLE FROM THE NW. THESE BRISK WINDS WILL SLOWLY SUBSIDE LATER TONIGHT. VFR CONDITIONS TO CONTINUE INTO SUNDAY THOUGH MID-HIGH LEVEL CLOUDS WILL BE INCREASING DURING THE DAY AS AN AREA OF LOW PRESSURE APPROACHES FROM THE WEST. MOISTURE AHEAD OF THIS SYSTEM WILL LEAD TO SUB VFR CEILINGS ALONG WITH PATCHES OF PRECIPITATION LATE SUNDAY NIGHT INTO MONDAY MORNING. AT ONSET...THIS PRECIPITATION MAY OCCUR AS A WINTRY MIX. THE SUB VFR CONDITIONS MAY LINGER INTO EARLY TUESDAY WITH IMPROVING CONDITIONS LATE TUESDAY INTO WEDNESDAY. && .CLIMATE... HERE ARE THE RECORD LOWS AND RECORD LOW MAXIMUM TEMPERATURES FOR SAT FEB 13TH AND SUN FEB 14TH AT GSO... RDU... AND FAY: REC YR REC YR LOW LOW MAX ---------------------------------------------- GSO: 02/13 11 1955 31 1986 02/14 6 1905 22 1914 RDU: 02/13 4 1899 10 1899 02/14 -2 1899 27 1916 FAY: 02/13 14 1973 32 1955 02/14 12 1968 33 1916 && .RAH WATCHES/WARNINGS/ADVISORIES... NONE && $$ SYNOPSIS...WSS NEAR TERM...SMITH SHORT TERM...ELLIS LONG TERM...HARTFIELD AVIATION...WSS CLIMATE...RAH
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1041 PM CST FRI FEB 12 2016 .DISCUSSION...SEE AVIATION SECTION FOR 06Z TAFS. && .AVIATION...HIGHER BOUNDARY LAYER MOISTURE IS OVER THE COASTAL PLAINS INTO THE EASTERN BRUSH COUNTRY LATE THIS EVENING WHILE WINDS DIMINISHED. TEMPERATURE/DEWPOINT DEPRESSIONS ARE NEAR ZERO OVER THE VICTORIA CROSSROADS. FOG/MVFR VSBYS EXPECTED TO DEVELOP 05-06Z IN THIS REGION WITH CONDITIONS DETERIORATING TO LIFR WITH DENSE FOG BY 07-08Z AND CONTINUE UNTIL AROUND 15Z. TIMING FOR FOG IN THE ALI/CRP AREA WILL BE DELAYED AN HOUR OR TWO WITH LIFR CONDS FORMING BY 08-09Z. EXPECT THE LOW CLOUDS AND FOG...IFR CIGS AND MVFR VSBYS...WILL REACH LRD AREA BY 11Z WITH LIFR VSBYS POSSIBLE IN NEAR DENSE FOG. VSBYS ARE EXPECTED TO IMPROVE BY 15-16Z TO VFR WITH MVFR CIGS HOLDING OVER VCT AREA THROUGH THE LATE MORNING BEFORE LIFTING. STRATUS IS EXPECTED TO MOVE BACK INTO THE VCT AREA AROUND 03Z SUNDAY. && .PREV DISCUSSION... /ISSUED 914 PM CST FRI FEB 12 2016/ DISCUSSION...DEWPOINT TEMPERATURES HAVE RISEN TO THE UPPER 50S TO NEAR 60 OVER THE COASTAL PLAINS THIS EVENING. WINDS WILL CONTINUE TO DIMINISH TONIGHT AS A WEAK FRONTAL BOUNDARY FROM NORTH OF HOUSTON TO SOUTH OF SAN ANTONIO REMAINS ESSENTIAL QUASISTATIONARY TONIGHT. TEMP-DEWPOINT DEPRESSIONS WERE THE LOWEST AROUND THE MID COAST AT 03Z. 00Z HRRR ALONG WITH 00Z NAM SHOW FOG WILL FORM OVER THE MID COAST REGION INITIALLY JUST AFTER 06Z AND SPREAD WESTWARD INTO THE BRUSH COUNTRY OVERNIGHT. ADDED CALHOUN AND ARANSAS COUNTIES INTO THE DENSE FOG ADVISORY. MAY NEED TO HAVE ADVISORY FOR WEBB AND LA SALLE COUNTIES LATER TONIGHT BUT NOT CONFIDENT ENOUGH AT THIS POINT TO INCLUDE IN THE ADVISORY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 55 74 57 78 56 / 0 10 10 10 0 VICTORIA 50 71 54 75 57 / 0 10 10 10 10 LAREDO 54 82 55 83 53 / 0 0 0 0 0 ALICE 52 78 54 82 55 / 0 0 10 10 0 ROCKPORT 56 70 60 73 60 / 0 10 10 10 10 COTULLA 50 80 54 83 51 / 0 0 0 0 0 KINGSVILLE 52 77 54 78 56 / 0 0 0 10 10 NAVY CORPUS 56 71 60 73 59 / 0 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...DENSE FOG ADVISORY FROM 2 AM TO 10 AM CST SATURDAY FOR THE FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...DUVAL...GOLIAD... JIM WELLS...KLEBERG...LIVE OAK...MCMULLEN...NUECES... REFUGIO...SAN PATRICIO...VICTORIA. GM...NONE. && $$ TMT/89...AVIATION
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1013 PM MST FRI FEB 12 2016 .UPDATE... ISSUED AT 1010 PM MST FRI FEB 12 2016 WEBCAMS NEAR CARPENTER IN EASTERN LARAMIE COUNTY...ALONG WITH DECREASING VISIBILITIES REPORTED AT PINE BLUFFS...LED ME TO EXPAND THE DENSE FOG ADVISORY FURTHER WEST. LATEST HRRR GUIDANCE AND 11-3.9U SATELLITE IMAGERY SHOWING THIS AS WELL...SO CONFIDENCE IS HIGH ON EXPANDING THIS ADVISORY. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 806 PM MST FRI FEB 12 2016 LATEST IBM AND SNY OBSERVATIONS IN THE SOUTHERN PANHANDLE SHOWING VISIBILITIES DOWN NEAR 1/4 MILE. THESE VISIBILITY REPORTS HAVE NOT CHANGED MUCH OVER THE PAST HOUR. LATEST 11-3.9U SATELLITE IMAGERY SHOWING THE LOW CLOUDS/FOG SPREADING WEST TOWARDS LARAMIE COUNTY NEAR PINE BLUFFS. WILL CONTINUE TO MONITOR AND MAY NEED TO EXTEND THE ADVISORY FURTHER WEST. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 708 PM MST FRI FEB 12 2016 GETTINGS REPORTS FROM THE SIDNEY AND KIMBALL ASOS/AWOS OF REDUCED VISIBILITIES IN FOG ALREADY THIS EVENING. CERTAINLY NEED TO WATCH CONDITIONS TO SEE IF THIS FOG BECOMES MORE WIDESPREAD. WENT AHEAD AND EXPANDED FOG WEST UP THE PLATTE RIVER VALLEY INTO TORRINGTON AND ACROSS THE NORTHERN PANHANDLE AS WELL. WILL CONTINUE MONITORING. UPDATES HAVE BEEN SENT. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 300 PM MST FRI FEB 12 2016 EARLY AFTERNOON WATER VAPOR IMAGERY SHOWED A UPPER RIDGE AXIS SITUATED OVER THE INTERMTN WEST WITH A DEEP UPPER TROUGH FROM HUDSON BAY CANADA TO FL. NORTHWEST FLOW ALOFT PREVAILED ACROSS THE FRONT RANGE AND HIGH PLAINS. THE LEADING EDGE OF A SHALLOW COLD AIR MASS HAD DRIFTED WEST INTO THE EASTERN 1/3 OF THE COWBOY STATE. EAST-NORTHEAST WINDS AND WESTERN EDGE OF STRATUS CLOUD DECK EXTENDED FROM NEAR LUSK WY TO JUST WEST OF SIDNEY NE. TEMPERATURES EAST OF THE FRONT WERE IN THE 20S AND 30S...WHILE WESTERLY WINDS AND 40S PREVAILED TO THE WEST. DURING THE NEXT 12-18 HOURS...PRIMARY CONCERNS WILL DEAL WITH POTENTIAL FOR PATCHY FREEZING DRIZZLE AND FOG OVER WESTERN NE PANHANDLE ASSOCIATED WITH THE SHALLOW COLD AIR MASS. THERE IS GOOD MODEL AGREEMENT PROGGING THE ARCTIC FRONT TO REMAIN NEARLY STATIONARY TONIGHT ACROSS THE EASTERN WY PLAINS THEN SLOWLY SHIFTING EAST INTO WESTERN NE SATURDAY MORNING. LATEST GFS/NAM BUFR SOUNDINGS INDICATE A NEARLY SATURATED LAYER FROM 700-950MB ALONG WITH A LIGHT LOW LEVEL SOUTHEASTERLY FLOW TONIGHT AND EARLY SATURDAY MORNING OVER WESTERN NE. PATCHY FREEZING DRIZZLE AND FOG DEVELOPING LATER THIS EVENING AND LINGERING THROUGH MID-LATE MORNING. THE FOG/DRIZZLE MAY EXTEND AS FAR WEST AS A LUSK WY-KIMBALL NE LINE...BUT CONFIDENCE NOT HIGH ATTM AND NEXT SHIFT CAN REEVALUATE WITH 00Z MODEL GUIDANCE. A SHORTWAVE TROUGH ENTERING THE PACIFIC NORTHWEST TONIGHT WILL QUICK MOVE ACROSS THE ID/MT SATURDAY MORNING...NORTHERN WY SATURDAY AFTERNOON...AND SD/NORTHERN NE SATURDAY NIGHT. THIS SHORTWAVE WILL INCREASE THE LEESIDE SURFACE PRESSURE GRADIENT WITH THE POTENTIAL FOR A GAP WIND EPISODE FOR ARLINGTON AND BORDEAUX SATURDAY AFTERNOON AND EVENING. THE CRAIG-CASPER HEIGHT 700-850MB GRADIENT EXCEEDS 60M BY 21Z SATURDAY...AND DECREASED BELOW 50M BY 06Z SUNDAY. WINDS AT 700MB PEAK NEAR 60 KT AT 00Z SUNDAY. ISSUED A HIGH WIND WATCH FOR WY ZONES 106 AND 110 FROM NOON TO 9 PM SATURDAY FOR THE POTENTIAL FOR WEST WIND GUSTS TO 60 MPH. SATURDAY WILL BE MILDER...ESPECIALLY EAST OF I-25 AS WESTERLY DOWNSLOPING WINDS SCOUR OUT THE SHALLOW COLD AIR MASS. AFTER A BRIEF LULL IN THE HIGH WINDS SATURDAY NIGHT...THEY PICK UP AGAIN SUNDAY MORNING WITH THE POTENTIAL FOR HIGH WINDS SPREADING EAST TO I-25 SUNDAY AFTERNOON. IF THE MODELS REMAIN CONSISTENT...HIGH WIND HEADLINES MAY BE ISSUED SATURDAY. SUNDAY WILL BE 5-10 DEGREES FOLLOWING THE PASSAGE OF A PACIFIC COLD FRONT. SOME LIGHT PRECIPITATION DEVELOPS INITIALLY ACROSS NORTHEAST WY/WESTERN SD SATURDAY EVENING AND SHIFTS EAST SATURDAY NIGHT. PACIFIC MOISTURE INCREASES WEST OF THE LARAMIE RANGE SUNDAY MORNING WITH LIGHT SNOW BECOMING MORE WIDESPREAD SUNDAY AFTERNOON. THERE IS A SLIGHT CHANCE OF LIGHT SNOW SPREADING EAST ONTO THE SOUTHEAST WY PLAINS SUNDAY NIGHT. MOST OF THE ACCUMULATING SNOW WILL OCCUR OVER THE SNOWY/SIERRA MADRE RANGES WITH UP TO 3 INCHES POSSIBLE. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 200 PM MST FRI FEB 12 2016 MONDAY...RELATIVELY MOIST NORTHWEST FLOW ALOFT WILL PRODUCE OROGRAPHIC SNOWFALL ACROSS THE SNOWY AND SIERRA MADRE RANGES WITH A SLIGHT CHANCE OF PRECIPITATION NORTH OF A DOUGLAS TO SCOTTSBLUFF LINE. TUESDAY...DRIER AND WARMER AS HEIGHTS AND THICKNESSES RISE AND THE ATMOSPHERE DRIES OUT SOMEWHAT. WEDNESDAY...PERHAPS THE WARMEST DAY NEXT WEEK AS THE RIDGE ALOFT MOVES OVERHEAD AND SURFACE LEE TROUGHING BECOMES WELL ESTABLISHED WITH VERY DRY ATMOSPHERE PROMOTING WARMING TEMPERATURES. THURSDAY...CONTINUED MILD IN THE WARM SECTOR AHEAD OF APPROACHING COLD FRONT. SOME OROGRAPHIC SNOW SHOWERS POSSIBLE NEAR THE SNOWY AND SIERRA MADRE RANGES LATE IN THE DAY WITH A SHORTWAVE TROUGH APPROACHING. FRIDAY...COOLER IN THE WAKE OF THE SHORTWAVE TROUGH ALOFT AND ITS ASSOCIATED COLD FRONT PASSAGE...THOUGH STILL RELATIVELY MILD FOR MID FEBRUARY BASED ON PROJECTED HEIGHTS AND THICKNESSES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1010 PM MST FRI FEB 12 2016 BACKDOOR FRONT TO REMAIN ALONG THE EAST SLOPES OF THE LARAMIE RANGE THROUGH THE OVERNIGHT HOURS. EASTERLY UPSLOPING WINDS OVER THE PANHANDLE WILL CONTINUE WIDESPREAD IFR/LIFR CONDITIONS FOR OUR NEBRASKA PANHANDLE AIRPORTS AT LEAST THROUGH 18Z. FOLLOWED LATEST HRRR GUIDANCE AND CONFIDENCE IS HIGH THAT LOW CONDITIONS WILL CONTINUE. WEST WINDS RETURN AFTER 18Z THAT WILL SCOUR OUT THE LOWER STRATUS. && .FIRE WEATHER... ISSUED AT 200 PM MST FRI FEB 12 2016 NO FIRE WEATHER CONCERNS THROUGH THE WEEKEND WITH COOL TO MILD TEMPERATURES AND RESIDUAL SNOW COVER. A NORTH-SOUTH ORIENTED COLD FRONT OVER THE HIGH PLAINS WILL SHIFT EASTWARD SATURDAY AS A QUICK MOVING UPPER LEVEL DISTURBANCE MOVES INTO NORTHERN WYOMING. THIS DISTURBANCE WILL TIGHTEN THE LEESIDE SURFACE PRESSURE GRADIENT WITH WEST WINDS BECOMING STRONG AND GUSTY ACROSS MUCH OF SOUTHEAST WYOMING. THE WINDY CONDITIONS WILL CONTINUE SUNDAY AS WELL. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR WYZ106-110. DENSE FOG ADVISORY UNTIL 5 AM MST SATURDAY FOR WYZ119. NE...DENSE FOG ADVISORY UNTIL 5 AM MST SATURDAY FOR NEZ054-055. && $$ UPDATE...GCC SHORT TERM...MAJ LONG TERM...RUBIN AVIATION...GCC FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
635 AM EST SAT FEB 13 2016 ...UPDATED AVIATION DISCUSSION... .SYNOPSIS... 08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS BROAD BUT AMPLIFIED UPPER LEVEL TROUGHING IN PLACE OVER THE EASTERN THIRD OF THE NATION. TROUGH IS ANCHORED BY A BROAD AND COLD UPPER LOW OVER EASTERN CANADA. FURTHER UPSTREAM WE FIND RIDGING THROUGH THE INTER-MOUNTAIN WEST...AND SHORTWAVE ENERGY ARRIVING OVER THE PACIFIC NORTHWEST/BRITISH COLUMBIA. BACK TO HOME...OUR REGION RESIDES WITHIN DEEP LAYER NW FLOW ON THE BACKSIDE OF THE EASTERN LONGWAVE TROUGH. SHORTWAVE ENERGY EMBEDDED WITHIN THE FLOW HAS EXITED OFF THE GA/CAROLINA COAST EARLY THIS MORNING. THIS PUSH IS DRIVING A WEAK COLD FRONT AT THE SURFACE DOWN FROM THE NORTH INTO THE FLORIDA PENINSULA. THE COLD FRONT IS CURRENTLY DROPPING SOUTH OVER THE NATURE COAST ZONES...AND SHOULD REACH THE I-4 CORRIDOR TOWARD SUNRISE...AND THEN EXIT SOUTH OF FORT MYERS BY MIDDAY. THIS IS A DRY FRONTAL PASSAGE WITH VERY LITTLE ATMOSPHERIC MOISTURE ABOVE 850MB. NARROW BAND OF LOW 2-4KFT CLOUDS LEADS THE FRONT...BUT THAT IS JUST ABOUT IT. THE FRONT WILL BE MOST MARKED BY A WIND SHIFT TO THE NORTH. LIKELY TO SEE SOME PATCHY FOG DEVELOPMENT IN THE PRE-DAWN HOURS AS WE GET SOME LOW LEVEL MOISTURE POOLING AHEAD OF THE FRONTAL BOUNDARY. THIS FOG MAY RESULT IN SOME TRICKY SPOTS FOR THE MORNING COMMUTE...BUT IT WILL NOT LAST LONG ONCE THE SUN COMES UP DUE TO THE COMBINATION OF DIURNAL MIXING...DRY AIR ADVECTION BEHIND THE FRONT. && .SHORT TERM (TODAY THROUGH SUNDAY)... AS MENTIONED IN THE SYNOPSIS...WEAK COLD FRONT WILL CROSS THE REGION THIS MORNING...AND BE SOUTH OF OUR ZONES BY THE AFTERNOON HOURS. THE AIRMASS CHANGE BEHIND THIS FRONT IS A BIT COOLER...BUT THE BIGGER CHANGE WILL BE IN THE MOISTURE AS DEWPOINTS QUICKLY DROP FROM NORTH TO SOUTH DURING THE DAY. IN FACT...AFTERNOON HIGH TEMPS WILL BE GENERALLY SEASONABLE...RANGING FROM THE LOWER 60S FAR NORTH TO THE MID/UPPER 60S CENTRAL...AND INTO THE LOWER 70S SOUTH. AFTER THE EARLY BAND OF CLOUDS...SKIES WILL BE MOSTLY SUNNY FOR THE MAJORITY OF THE DAY. THE FORECAST FOR TONIGHT IS COLDER...MAINLY DUE TO THE DRY AIR THAT WILL BE IN PLACE. HIGH PRESSURE DOES BUILD IN FROM THE NORTH...BUT THE RIDGE CENTER STAYS UP OVER THE MID-ATLANTIC STATES AND NEVER REALLY ALLOWS THE GRADIENT TO SLACKEN SUFFICIENTLY FOR IDEAL RADIATIONAL COOLING OVER OUR ZONES. AT THE VERY LEAST...THE RADIATIVE PROCESS WILL BE SLOWED...AND DOUBT MOST PLACES (OTHER THAN EXTREMELY WELL SHELTERED LOCATIONS) WILL BE ABLE TO DECOUPLE OVERNIGHT. SO...WHILE THE WIND MAY HELP KEEP MORE LOCATIONS ABOVE FREEZING...IT WILL LOWER THE POTENTIAL WIND CHILL VALUES FOR EARLY SUNDAY MORNING. DEEPEST INTO THE AIRMASS AND BEST POTENTIAL FOR RADIATIVE PROCESSES WILL BE OUR FAR NORTHERN ZONES. ALLOW INTERIOR LEVY COUNTY TO TOUCH 32 BRIEFLY AT DAWN...BUT OTHERWISE KEEP TEMPS ABOVE FREEZING. RANGE LOW TEMPS FROM THESE LOWER 30S OVER LEVY COUNTY...TO THE UPPER 30S/LOWER 40S BY THE I-4 CORRIDOR...AND GENERALLY IN THE LOWER/MID 40S FURTHER SOUTH. LOCATIONS SUCH AS SOUTHERN PINELLAS COUNTY AND THE ISLANDS/CAPES OF CHARLOTTE HARBOR WILL BE A BIT WARMER WITH NORTHEAST FLOW OFF WATER. AGAIN THOUGH...WINDS WILL NOT BE STRONG...BUT WILL NOT BE CALM EITHER. WIND CHILL VALUES ARE CURRENTLY FORECAST TO DROP INTO THE 30S LATE TONIGHT AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS COUNTIES. NORTH OF BROOKSVILLE...WIND CHILL VALUES MAY BRIEFLY DROP INTO THE 20S. HIGH PRESSURE SHIFTS OFF THE ATLANTIC SEABOARD DURING SUNDAY...SHIFTING OUR WINDS TO THE EAST. THIS FLOW WILL BRING A SLOW INCREASE IN LOW LEVEL MOISTURE BACK ACROSS THE PENINSULA FROM THE ATLANTIC. FOR OUR FORECAST...THIS MAINLY JUST MEANS A RETURN TO A SCT CUMULUS FIELD FOR THE AFTERNOON HOURS. MANY GUIDANCE MEMBERS ARE SHOWING SOME CONVERGENCE SHOWERS ALONG THE FLORIDA EAST COAST ON SUNDAY THAT WILL ATTEMPT TO MIGRATE INLAND. NOT COMPLETELY SOLD ON THIS POTENTIAL AS THE MOISTURE DEPTH IS REALLY LACKING. HOWEVER...WILL ADD MENTION OF A FEW ISOLATED SPRINKLES AFTER 18Z SUNDAY ACROSS FAR EASTERN POLK/HIGHLANDS COUNTIES. ANY SPRINKLES WILL HAVE LIMITED TO NO IMPACT ON ANY OUTDOOR ACTIVITIES. TEMPERATURES REGION-WIDE FOR SUNDAY SHOULD RECOVER FROM THE CHILLY MORNING TEMPS TO THE 60S FOR THE AFTERNOON. && .LONG TERM (MONDAY THROUGH NEXT FRIDAY)... AN UPPER TROUGH INITIALLY FROM MANITOBA TO THE WESTERN GULF OF MEXICO WILL SHARPEN AND SHIFT INTO THE EASTERN COASTAL STATES TUE...AS A SURFACE LOW FORMS ON THE GULF COAST AND TRACKS TO THE MID- ATLANTIC STATES. THE LOW TRAILS A COLD FRONT INTO THE EASTERN GULF MON NIGHT AND ACROSS FL TUE. AS THE UPPER TROUGH AND SURFACE LOW MOVE EAST A RIDGE OF HIGH PRESSURE ALONG THEE EASTERN SEABOARD SLIDES EAST. AS IT DOES THE LOW LEVEL FLOW VEERS FROM EASTERLY TO SOUTHERLY BY MON NIGHT...HELPING TO MOISTEN THE ATMOSPHERE ALTHOUGH MODELS ONLY INCREASE PWAT VALUES INTO THE 1 TO 1.5 INCH RANGE. BUT THIS WILL BE ENOUGH ALONG WITH THE UPPER TROUGH AND COLD FRONT FOR SHOWERS AND THUNDERSTORMS...STARTING MON AFTERNOON THEN ENDING TUE AS THE FRONT EXITS TO THE EAST. THE GREATEST ODDS OF SHOWERS AND STORMS WILL BE MON NIGHT AND EARLY TUE MORNING. CURRENTLY THE BEST DYNAMICS FOR SEVERE STORMS APPEAR TO STAY NORTH OF THE AREA. FOR WED THROUGH FRI - THE UPPER TROUGH SLOWLY SLIPS OFFSHORE AS AN UPPER RIDGE BUILDS NORTHWARD OVER THE WESTERN STATES THEN MOVES ACROSS THE EASTERN STATES AS IT FLATTENS SOME. SURFACE HIGH PRESSURE BUILDS IN OVER THE MID-MISSISSIPPI VALLEY THEN MIGRATES TO THE ATLANTIC COAST WATERS. A DRY AND STABLE AIRMASS WILL BE IN PLACE TEMPERATURES RUNNING CLOSE TO SEASONAL. WINDS REMAIN RATHER MODEST...ONLY BRIEFLY APPROACHING 20 KNOTS ON THE GULF MON AND TUE AHEAD OF THE FRONT. && .AVIATION (THROUGH 12Z SUNDAY)... A NARROW BAND OF BKN MVFR CIGS WILL CONTINUE TO DROP SOUTH THROUGH THE REGION EARLY THIS MORNING IN ADVANCE OF A WEAK COLD FRONT. THIS FRONT IS CURRENTLY CROSSING THE I-4 CORRIDOR THROUGH KTPA/KPIE/KLAL...AND WILL CONTINUE SOUTH OF KFMY/KRSW BY MIDDAY. MVFR CIGS AND PATCHY DENSE FOG THROUGH THE I-4 TERMINALS WILL IMPROVE SHORTLY AFTER SUNRISE WITH THE FRONTAL PASSAGE. WINDS SHIFT NORTHERLY BEHIND THE FRONT...AND THEN NORTHEASTERLY TONIGHT. PREVAILING VFR CONDITIONS ARE FORECAST THROUGH 12Z SUNDAY FOR ALL TERMINALS AFTER THE PASSAGE OF THE FRONT THIS MORNING. && .MARINE... A WEAK COLD FRONT DROPS SOUTHWARD THROUGH THE FORECAST WATERS THIS MORNING. WINDS WILL SHIFT TO THE NORTH BEHIND THIS FRONT REACHING CAUTIONARY LEVELS AT TIMES...OUTSIDE OF THE BAYS AND HARBORS. HIGH PRESSURE MOVING NORTH OF THE REGION TONIGHT WILL SHIFT WINDS TO THE NORTHEAST...WITH THE POTENTIAL FOR A MORE WIDESPREAD PERIOD OF CAUTIONARY LEVEL WINDS. WINDS SHIFT EAST ON SUNDAY AND DIMINISH BELOW HEADLINE CRITERIA BY THE AFTERNOON HOURS. THE NEXT COLD FRONT CROSSES THE EASTERN GULF OF MEXICO MONDAY NIGHT AND EARLY TUESDAY. WINDS CURRENTLY ARE NOT EXPECTED TO REACH HEADLINE CRITERIA BEHIND THIS FRONT THROUGH THE DAYLIGHT HOURS OF WEDNESDAY. && .FIRE WEATHER... A MUCH DRIER AIRMASS WILL ARRIVE ON NORTHERLY WINDS TODAY IN THE WAKE OF A WEAK COLD FRONT. WITH THE DRY AIR...RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP BELOW 35 PERCENT FOR SEVERAL HOURS THIS AFTERNOON AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS COUNTIES. NORTH OF THE I-4 CORRIDOR...RELATIVE HUMIDITY IS EXPECTED TO DROP INTO THE 20S FOR A TIME. ALTHOUGH IT WILL BE DRY...RED FLAG CONDITIONS ARE NOT FORECAST AS ERC VALUES REMAIN AT OR BELOW 25...AND WINDS WILL STAY BELOW CRITICAL LEVELS. LOW LEVEL MOISTURE BEGINS TO INCREASE DURING SUNDAY ON LIGHT EASTERLY FLOW...AND THIS MOISTURE RETURN CONTINUES INTO MONDAY. AFTER THIS AFTERNOON...CRITICAL LEVELS OF RELATIVE HUMIDITY ARE NOT EXPECTED THROUGH THE EARLY PORTION OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... TPA 65 43 68 54 / 0 0 0 0 FMY 73 47 72 55 / 0 0 0 0 GIF 69 43 66 53 / 0 0 10 10 SRQ 67 44 68 54 / 0 0 0 0 BKV 65 38 67 49 / 0 0 0 0 SPG 65 48 67 56 / 0 0 0 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR COASTAL CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL SARASOTA. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...MROCZKA LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
951 AM CST SAT FEB 13 2016 .UPDATE... ISSUED AT 947 AM CST SAT FEB 13 2016 NO SIGNIFICANT CHANGES WERE NEEDED FOR THIS UPDATE. DID INCREASE PRECIPITATION CHANCES OVER THE WEST AND CENTRAL THROUGH 18Z...AS MULTIPLE OBSERVATIONS ARE COMING IN WITH LIGHT SNOW WHERE THERE HAVE BEEN LITTLE TO NO RADAR RETURNS. THINKING REMAINS THE SAME ON WINTER WEATHER HEADLINES AS WE ENTER A HOLDING PATTERN...WITH LOW PRESSURE NOW DEVELOPING OVER SOUTHERN SASKATCHEWAN AND NORTHERN WYOMING. UPDATE ISSUED AT 701 AM CST SAT FEB 13 2016 EXPANDED THE WINTER WEATHER ADVISORY INTO THE NORTH CENTRAL AND TURTLE MOUNTAINS AREA FOR THIS AFTERNOON THROUGH TONIGHT WITH THIS UPDATE. THE FULL 00 AND 06 UTC DETERMINISTIC AND ENSEMBLE SUITES AND THE 08-11 UTC HRRR AND RAP ITERATIONS ALL SUPPORT THE POTENTIAL FOR MODERATE SNOWFALL ACCUMULATIONS ACROSS THE NORTH CENTRAL AND TURTLE MOUNTAINS AREA THIS AFTERNOON THROUGH TONIGHT. OVERALL...A CONSENSUS OF THESE SOLUTIONS SUPPORTS GREATER QPF THAN THE PREVIOUS FORECAST OVER MOST OF THE CWA THIS AFTERNOON THROUGH TONIGHT...LEADING TO GREATER SNOWFALL TOTALS. OBSERVED TRENDS ACROSS MONTANA THIS MORNING AND THE 12 UTC SUITE WILL HAVE TO BE CLOSELY EVALUATED AS SOME LOCATIONS ACROSS CENTRAL NORTH DAKOTA HAVE THE POTENTIAL TO APPROACH WARNING LEVEL SNOWFALL AS DEPICTED IN 00 AND 06 UTC SUITES. HEAVY SNOWFALL RATES ARE POSSIBLE GIVEN STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH THE POTENT SHORTWAVE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM CST SAT FEB 13 2016 THE FOCUS OF THE SHORT TERM FORECAST IS A WINTRY MIX IN WESTERN ND AND SNOWFALL IN CENTRAL ND. A FREEZING RAIN ADVISORY WILL BE ISSUED FOR SOUTHWESTERN NORTH DAKOTA...AND A WINTER WEATHER ADVISORY FOR THE SOUTH CENTRAL. CURRENTLY...ARCTIC HIGH PRESSURE EXTENDED FROM MANITOBA TO IOWA...WITH LOW PRESSURE ALONG THE LEE OF THE ROCKIES. TEMPERATURES HAVE BEEN RISING ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY THIS MORNING. LOWS RANGED FROM 5 TO 20 BELOW ZERO FROM THE TURTLE MOUNTAINS TO THE JAMES RIVER VALLEY...BUT WERE CURRENTLY AROUND 5 BELOW ZERO. FARTHER WEST TEMPERATURES HAVE BEEN FAIRLY STEADY OR RISING...WITH TEENS IN THE FAR WEST ALL NIGHT. WARM ADVECTION FROM THE WEST...ACCOMPANIED BY ISENTROPIC LIFT...WAS ASSOCIATED WITH A BAND OF LIGHT SNOW THAT EXTENDED FROM WILLISTON AND STANLEY IN THE NORTHWEST TO GRANT AND SIOUX COUNTIES IN THE SOUTH CENTRAL PART OF THE STATE. THE LATEST ITERATIONS OF THE HIGHRES MODELS INDICATE THIS BAND OF LIGHT SNOW WEAKENING/DISSIPATING AS IT PROGRESSES EASTWARD THIS MORNING. A SIGNIFICANT UPPER LEVEL SHORTWAVE IS FORECAST TO MOVE EAST ACROSS IDAHO AND MONTANA THIS MORNING...THEN MOVE SOUTHEAST ACROSS THE DAKOTAS THIS AFTERNOON AND TONIGHT. PRECIPITATION IS EXPECTED TO DEVELOP BEFORE NOON IN THE SOUTHWEST AND AROUND NOON IN CENTRAL NORTH DAKOTA ASSOCIATED WITH THIS SHORTWAVE. THE 00Z AND 06Z HIGHRES MODELS SUGGEST STRONG WARM ADVECTION CONTINUING IN THE SOUTHWEST...WITH MAX TEMPERATURES ALOFT AROUND +3 TO +5 C. THUS THE THERMAL PROFILES SUGGEST A MIX OF LIGHT FREEZING RAIN...SLEET...SNOW...OR RAIN AT TIMES THIS AFTERNOON. AS THE SHORTWAVE PASSES THROUGH...COLD ADVECTION WILL ENSUE AND PRECIPITATION WILL LIKELY CHANGE TO LIGHT SNOW THIS EVENING IN SOUTHWESTERN NORTH DAKOTA. IN SOUTH CENTRAL NORTH DAKOTA...THE THERMAL PROFILES SUGGEST MAINLY SNOW...BUT A MIX OF SLEET OR FREEZING RAIN IS POSSIBLE AS WELL - ESPECIALLY DURING THE AFTERNOON. MODELS ARE NOT IN THE BEST AGREEMENT REGARDING SNOW AMOUNTS...BUT CONSENSUS SNOW AMOUNTS ARE IN THE 3-5 INCH RANGE BY DAYBREAK SUNDAY MORNING. THUS CONFIDENT ON AT LEAST WINTER WEATHER ADVISORY FOR THE SOUTH CENTRAL. SOME OF THE LATEST ITERATIONS OF THE SHORT TERM MODELS ARE HINTING AT HIGHER SNOW AMOUNTS...BUT CONFIDENCE IS LOWER - MAINLY BECAUSE IF THERMAL PROFILES ARE WARMER/COOLER THAN FORECAST THIS WILL IMPACT SNOW AMOUNTS. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 346 AM CST SAT FEB 13 2016 ABOVE NORMAL TEMPERATURES HIGHLIGHT THE EXTENDED FORECAST. THE 00 UTC AND INCOMING 06 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN GOOD AGREEMENT ON A BROAD...LOW AMPLITUDE UPPER LEVEL RIDGE BUILDING ACROSS THE CENTRAL CONUS THROUGHOUT THE EXTENDED FORECAST PERIOD. THUS...ABOVE NORMAL HIGH TEMPERATURES IN THE 30S AND 40S ARE EXPECTED OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THROUGHOUT THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 701 AM CST SAT FEB 13 2016 A BAND OF LIGHT SNOW WAS OVER NORTHWEST AND CENTRAL NORTH DAKOTA EARLY THIS MORNING WITH CEILINGS AND VSBYS LOWERING TO MVFR. EXPECT MVFR CEILINGS TO REMAIN AT CENTRAL ND SITES ONCE THEY ARRIVE. BUT PERHAPS A PERIOD OF LOW VFR CEILINGS AT KISN AND KDIK 12-18Z BEFORE LOWERING BACK TO MVFR AFT 18Z SAT. MAIN CONCERN IS LATER ON SATURDAY 15Z- 23Z IN WESTERN ND WHEN WARM ADVECTION FROM THE WEST WOULD BRING A WINTRY MIX STARTING WITH SNOW...LEADING TO SLEET...THEN FREEZING RAIN...BEFORE CHANGING BACK TO SNOW AFT 00Z. WILL BE ANALYZING LATEST MODELS AND HOPE TO HAVE A HIGHER CONFIDENCE LEVEL FOR THE 12Z TAF ISSUANCE FOR TIMING AT KISN AND KDIK. && .BIS WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR NDZ004-005-011>013-019>023-025-034>037-042-045>048-050-051. FREEZING RAIN ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT FOR NDZ017-018-031>033-040-041-043-044. && $$ UPDATE...ZH SHORT TERM...JV LONG TERM...AYD AVIATION...AYD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1013 AM EST SAT FEB 13 2016 .SYNOPSIS... POLAR VORTEX OVR S QUEBEC WILL RAPIDLY LIFT NE BY LATE IN THE WEEKEND. A DEEPENING UPPER LVL TROF OVER THE CENTRAL CONUS WILL SPAWN A LOW PRES SYSTEM...WHICH WILL LIKELY TRACK NORTHWARD ACROSS EASTERN PA ON TUESDAY. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... ARCTIC AIR MASS CONTINUES TO PUSH THROUGH THE REGION TODAY. TEMPERATURES WILL NOT MOVE TOO MUCH HIGHER THAN CURRENT VALUES. STRONG NORTHWEST WINDS AND TEMPERATURES IN JUST ABOVE ZERO IN THE NORTHWESTERN AREAS TO A BALMY MID-TEENS IN THE SOUTHEAST WILL PROVIDE FOR A VERY COLD DAY. WIND CHILLS BELOW ZERO OVER MOST OF THE REGION TODAY INTO SUNDAY. WIND GUSTS OF 25 TO 35 MPH HAVE BEEN OBSERVED SO FAR TODAY. COVER UP WELL IF OUTDOORS OVER THE NEXT 36 HOURS OF SO. RADAR AND SATELLITE IMAGERY SHOW HURON CONNECTION SNOW BANDS. ONE BAND MADE INTO STATE COLLEGE AROUND 9 AM FOR A QUICK COATING. THIS BAND IS MOVING TO THE SOUTHEAST AND COULD BRING LIGHT SNOW/FLURRIES TO LOWER SUSQUEHANNA VALLEY LATER THIS MORNING. MORE FOCUSED SNOW IS OVER SOUTHWEST MOUNTAINS. SNOW IN NORTHWESTER AREAS HAS BEEN QUITE LIMITED. THE NCAR 3KM EFS AND THE HRRR SEEM TO FOCUS SNOW IN SOUTHWEST MOUNTAINS AND HAVE LIMITED SNOW IN THEIR RESPECTIVE FORECASTS. THE AIR IS VERY DRY AND HAS NOT BEEN A PROLIFIC LAKE AND MOUNTAIN SNOW PRODUCER. HIGH RESOLUTION MODELS KEEP INDICATING THIS. HRRR AT TIMES SHOWS A POTENTIAL MODEST BAND IN NORTHWESTERN PA THIS EVENING. COLD WILL BE THE ISSUE OVER THE ENTIRE REGION. BEST ACCUMULATING SNOW POTENTIAL IN THE SOUTHWEST MOUNTAINS. && .SHORT TERM /7 PM THIS EVENING THROUGH 7 PM SUNDAY/... MODELS NOT VERY BIG IN SNOW OVERNIGHT INTO SUNDAY. SOME HINTS OF SNOW EARLY IN THE HRRR AND SREF IN SW MOUNTAINS. COMBINED WITH THE FALLING INVERSION HEIGHTS AHEAD OF APPROACHING HIGH...LES AND MOUNTAIN SNOW THREATS WILL DIMINISH. THE HIGH SHOULD DECOUPLE SOME AREAS OVERNIGHT AND WITH SNOW COVER A GOOD PERIOD OF RADIATIONAL COOLING IS POSSIBLE IN CENTRAL AND WESTERN AREAS. THE MASSIVE 1032 TO 1036 HIGH MOVES OVER THE REGION AND IS PARKED OVERHEAD BY MIDDAY SUNDAY. THIS SHOULD ENSURE THE WINDS DIE AND THE WINDCHILL ISSUE DIMINISH. BUT WILL STILL BE A VERY COLD VALENTINES AT LEAST OUTDOORS. THE EVENING SHOULD STILL HAVE NEAR IDEAL RADIATIONAL COOLING CONDITIONS. VERY COLD START TO THE OVERNIGHT PERIOD SUNDAY INTO MONDAY....BUT THE HIGH MOVES OFF FAST SUNDAY NIGHT. OVERNIGHT LOW SUNDAY LIKELY WILL BE EARLY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... *IMPACT WEATHER HIGHLIGHTS: POTENTIAL WINTER STORM EARLY NEXT WEEK. BULK OF MED RANGE GUIDANCE INDICATES THE LIKELIHOOD OF SOME LGT SNOW ARRIVING MONDAY...AS SFC HIGH DRIFTS OFF THE COAST AND MILDER SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS. HOWEVER...THE BIGGER CONCERN INVOLVES DIGGING UPPER TROF OVR THE MISS VALLEY AND ASSOC SFC LOW PRESSURE LIFTING UP THE APPALACHIANS. MDL SPREAD CONTINUES TO NARROW...WITH MOST RUNS TRACKING SFC LOW ACROSS EASTERN PA TUESDAY. THIS TRACK WOULD CERTAINLY FAVOR RAIN ACROSS EASTERN PA AND RAIN OR SNOW ACROSS WESTERN PA. GIVEN INHERENT MDL UNCERTAINTIES THIS FAR OUT...WILL MAINTAIN RAIN/SNOW IN THE FCST FOR MOST OF CENTRAL PA MON NIGHT-TUES. HAVE RAISED POPS INTO THE LIKELY CATEGORY BASED ON CONVERGING MDL SOLUTIONS. WILL ALSO HAVE TO WATCH FOR THE POSSIBILITY OF FLOODING ACROSS EASTERN PA...GIVEN RAINFALL AND SNOWMELT POTENTIAL. LATEST MDL ENSEMBLE RIVER FORECASTS USING NAEFS SUGGESTS MINOR FLOODING IS A POSSIBILITY ACROSS THE LOWER SUSQ VALLEY BY TUES. WPC ALSO HAS HIGHLIGHTED SE PA FOR A SLIGHT RISK OF FLOODING TUESDAY. NEAR TO ABOVE NORMAL TEMPS APPEAR LIKELY LATER NEXT WEEK...AS HEIGHTS ARE FORECAST TO RISE AND A PSBL LOW PRESSURE SYSTEM LIFTS THROUGH THE GREAT LAKES TO THE WEST OF PA. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... ARCTIC AIR MASS POURING INTO THE REGION EARLY THIS MORNING... CURRENTLY ACCOMPANIED BY GUSTY NW WINDS OF 15G25KTS. WINDS WILL PICK UP FURTHER DURING THE DAY...WITH GUSTS APPROACHING 40-45KTS...BEFORE GRADUALLY DIMINISHING TONIGHT. RADAR AT 11Z SHOWING SCT SHSN ACCOMPANYING ARRIVAL OF ARCTIC AIR MASS ACROSS WESTERN/CENTRAL MTNS. ARRIVAL OF LOW PWAT AIR MASS SHOULD CAUSE MOST OF THESE SNOW SHOWERS TO DISSIPATE EARLY IN THE DAY. SNOW SHOWERS WILL LINGER OVER WARREN COUNTY /WITH POSSIBLE BRIEF EXCURSIONS TOWARD KBFD/ WITH MORE PERSISTENT SNOW SHOWERS/BANDS ASSOC WITH LK HURON CONNECTION TO LAST THRU THE DAY ACROSS THE LAUREL HIGHLANDS /KJST/. RESTRICTIONS WILL PERSIST OVER WESTERN HIGHER TERRAIN. BUT WITH DOWNSLOPE FLOW KICKING IN FOR CENTRAL MTNS AND SE...VFR WILL BE THE GENERAL RULE - WITH JUST A CHANCE FOR SOME SCT SNOW BANDS TO CREEP INTO PORTIONS OF THE CENTRAL MTNS LATE DAY. OUTLOOK... SUN...NO SIG WX EXPECTED. MON...WIDESPREAD RESTRICTIONS DEVELOP WITH SNOW DEVELOPING. MON NIGHT AND TUE...SNOW LIKELY NW HALF OF PENN...WITH RAIN AND/OR SNOW IN THE SE. WIDESPREAD RESTRICTIONS CONTINUE. LLWS POSS SE. WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST. && .CTP WATCHES/WARNINGS/ADVISORIES... WIND CHILL WARNING UNTIL 11 AM EST SUNDAY FOR PAZ004>006-037- 041-042. WIND CHILL ADVISORY UNTIL 11 AM EST SUNDAY FOR PAZ010>012-017- 018-024-033. WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR PAZ019-025>028- 034>036-045-046-049>053-056>059-063>066. WIND CHILL ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST SUNDAY FOR PAZ019-025>028-034>036-045-046-049>053-056>059- 063>066. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024- 033. && $$ SYNOPSIS...FITZGERALD NEAR TERM...GRUMM SHORT TERM...GRUMM/FITZGERALD LONG TERM...FITZGERALD/GARTNER AVIATION...RXR
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
925 AM CST SAT FEB 13 2016 .UPDATE... FIRST VISIBILITY HAS IMPROVED SOUTH OF A FRONTAL BOUNDARY SO LET DENSE FOG ADVISORY EXPIRE. BASED ON 15Z SFC OBS...FRONTAL BOUNDARY LOCATED FROM LA GRANGE TO SUGAR LAND TO GALVESTON. LATEST 14Z HRRR HAS THIS BOUNDARY FAIRLY WELL RESOLVED AND BEGINS TO PUSH THE BOUNDARY BACK NORTH LATER THIS AFTERNOON AND TURNS WINDS TO SE. THERE MAY BE ENOUGH CLOUD COVER AND COOLER AIR TO KEEP MAX TEMPS IN THE 60S BUT MAY STILL FEEL HUMID WITH DEWPOINTS IN THE 50S SOUTH OF THE BOUNDARY. MAIN UPDATES TO THE FORECAST WERE TO ENSURE CONSISTENCY WITH ONGOING TRENDS AND LATEST SHORT RANGE GUIDANCE. OVERALL NOT A LOT OF CHANGE FROM THE PREVIOUS UPDATE. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 67 52 71 56 71 / 10 10 20 20 20 HOUSTON (IAH) 68 51 71 58 72 / 10 10 20 30 30 GALVESTON (GLS) 61 56 69 58 68 / 10 10 20 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...39
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 PM EST SAT FEB 13 2016 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 401 PM EST SAT FEB 13 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP TROF OVER SE CANADA INTO THE NE CONUS WITH THE CORE OF THE COLDEST AIR WELL E OF HERE NOW. UPSTREAM...NEXT SHORTWAVE OF INTEREST IS MOVING ACROSS THE NRN ROCKIES. CLOSER TO HOME...WITH LATEST RAP ANALYSIS SHOWING 850MB TEMPS ACROSS LAKE SUPERIOR RANGING FROM AROUND -19C W TO -25C E... LES CONTINUES. HOWEVER...UNDER RISING HEIGHTS/SUBSIDENCE... INVERSION IS DOWN TO AROUND 3KFT W AND 5KFT E. SO...LES IS LIGHT... BUT STILL EFFECTIVE AT REDUCING VIS OVER THE E DUE TO SMALL SNOWFLAKE SIZE. WELL AWAY FROM LAKE EFFECT...IT`S BEEN A MOSTLY SUNNY DAY OVER SCNTRL UPPER MI. LINGERING LIGHT LES WILL END FROM W TO E TONIGHT AS SFC HIGH PRES RIDGE PASSES ACROSS THE FCST AREA. WITH MODERATING AIR MASS RESULTING IN THE DGZ LIFTING INTO THE SHALLOW CONVECTIVE LAYER...MIGHT BE ABLE TO FLUFF UP AN INCH OR TWO OF SNOW ACCUMULATION WHERE STRENGTHENING LAND BREEZES FOCUS CONVERGENCE... MOST LIKELY IN THE E HALF OF ALGER/NRN SCHOOLCRAFT COUNTIES. RIDGE WILL ARRIVE OVER WRN UPPER MI EARLY THIS EVENING AND THE E OVERNIGHT. LOSS OF LAKE EFFECT CLOUDS WITH BACKING WINDS WILL BE REPLACED BY SOME INCREASE IN HIGH CLOUDS IN WAA PATTERN AHEAD OF SHORTWAVE MOVING INTO THE NRN/CNTRL PLAINS. THAT SAID...ALL AREAS WILL SEE AT LEAST A SHORT PERIOD OF VERY GOOD RADIATIONAL COOLING CONDITIONS. IT STILL APPEARS THE CNTRL FCST AREA WILL HAVE THE LONGEST PERIOD OF EXCELLENT RADIATIONAL COOLING DUE TO CLEAR SKIES TO START THE EVENING...LATER ARRIVAL OF HIGH CLOUDS AND LONGER PERIOD OF LIGHT/CALM WIND. AS WITH PREVIOUS FCSTS...MAINTAINED A MIN TEMP FCST AT OR BLO THE LOWEST GUIDANCE WITH THE TRADITIONAL COLDEST SPOTS FALLING TOWARD -20F. MOST IF NOT ALL LOCATIONS WILL FALL BLO 0F. ON SUN...SHORTWAVE MOVING OUT OVER THE PLAINS TONIGHT WILL TRACK ESE WITH ASSOCIATED DEEP LAYER FORCING PER QVECTORS AND BEST ISENTROPIC ASCENT PASSING S OF UPPER MI. MODEL TREND OF RECENT DAYS TO PUSH FORCING/PCPN FARTHER S HAS HELD UP IN LATEST MODEL RUNS. AS A RESULT...DO NOT EXPECT ANY -SN ASSOCIATED WITH THIS FEATURE TO REACH THE FCST AREA SUN. ATTENTION THEN TURNS TO LES OFF LAKE MICHIGAN UNDER DEVELOPING/INCREASING SOUTHERLY FLOW ON THE BACKSIDE OF DEPARTING HIGH PRES. 850MB TEMPS AROUND -17C AT 12Z RISE TO AROUND -14C BY 00Z MON...CERTAINLY LOW ENOUGH TO SUPPORT LES. LARGE SCALE ANTICYCLONIC FLOW AND INVERSIONS AT 4-5KFT WILL LIMIT INTENSITY OF LES. IN ADDITION...MOST HIGH RES MODEL GUIDANCE DEPICT THE LES MOSTLY AS A BAND LIFTING N ON A WIND CONVERGENCE ZONE. WHILE THIS MAY LEAD TO A BURST OF MDT SNOWFALL...ESPECIALLY WITH DGZ SOLIDLY IN THE CONVECTIVE LAYER...THE HEAVIER SNOW WOULD NOT LAST LONG. FOR NOW...EXPECT SNOW ACCUMULATIONS UNDER 1 INCH...BUT NOT OUT OF THE QUESTION FOR LOCALIZED INCH OR TWO OF SNOW ACCUMULATION IF THE CONVERGENCE ZONE IS STRONG. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 320 PM EST SAT FEB 13 2016 LONG TERM STARTS 00Z MON WITH A SHORTWAVE NEAR SRN LAKE MICHIGAN THAT WILL CROSS LAKE HURON BY 12Z MON AND THEN MOVE INTO QUEBEC...AND ANOTHER SHORTWAVE OVER CENTRAL MN THAT WILL MOVE OVER OR JUST S OF THE CWA LATE SUN NIGHT INTO MON AFTERNOON...AND YET ANOTHER SHORTWAVE WILL FOLLOW THE SECOND BY ABOUT 12 HOURS. NOT REALLY LOOKING FOR A LOT OF SYNOPTIC QPF...BUT THE FORCING/MOISTURE WILL ENHANCE LES OFF LAKE MICHIGAN IN THE SLY FLOW AHEAD OF THE ACCOMPANYING SFC TROUGH. SLY WIND LAKE EFFECT IS ALWAYS TRICKY...BUT LOOKS LIKE IT SHOULD START UP AROUND 00Z MON AND REACH A PEAK BETWEEN 06Z AND 18Z MON WHILE SHIFTING E AND ENDING BEFORE 00Z TUE. AT THIS POINT...IT LOOKS LIKE THE MOST SNOW WILL FALL ACROSS MENOMINEE...DELTA...AND SCHOOLCRAFT COUNTIES...AND POSSIBLY INTO COUNTIES JUST N OF THOSE. THINK WITH S WINDS...THINK MENOMINEE COUNTY SEEING MUCH LES IS NOT AS LIKELY. OVERALL...ONLY EXPECTING 2 TO MAYBE 3 INCHES IN THESE AREAS. ELSEWHERE...AROUND AN INCH OR LESS. MAY SEE SOME LIGHT LES OVER W WIND SNOWBELTS MON NIGHT INTO TUE MORNING AS 850MB TEMPS WILL BE MARGINAL BUT ADDITIONAL SHORTWAVE WILL PROVIDE SOME ENHANCEMENT. NOT LOOKING AT SIGNIFICANT AMOUNTS. SFC TROUGH MOVES THROUGH TUE AHEAD OF AN UPPER WAVE. THIS TURNS WINDS OUT OF THE NW-NNW BY TUE AFTERNOON/EVENING AND DROPS 850MB TEMPS TO AROUND-15Z BY 00Z WED AND -19C BY 12Z WED. A SFC RIDGE MOVES THROUGH BY 00Z THU...ENDING MOST OR ALL LES. NOT EXPECTING SIGNIFICANT SNOWFALL AMOUNTS GIVEN CHANGING WIND DIRECTIONS AND QUICK ENTRANCE OF THE RIDGE. COULD SEE A MORE POTENT SYSTEM LATE IN THE WEEK...WITH THE POSSIBILITY OF SNOW...RAIN...AND FREEZING RAIN. HOWEVER...CONFIDENCE EVEN IN THE GENERAL STRENGTH/TRACK OF THE SYSTEM IS LOW AS MODELS VARY FROM RUN TO RUN AND DISAGREE MODEL TO MODEL. CERTAINLY LOOKS LIKE A WARMUP IS IN STORE FOR AT LEAST THU NIGHT AND FRI...BUT CAN NOT SAY MUCH ELSE WITH CONFIDENCE. MAINLY WENT WITH A WINTRY MIX OF PRECIP IN THE FORECAST...WITH CONSENSUS POPS FIELDS OTHERWISE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1244 PM EST SAT FEB 13 2016 WITH WINDS BACKING AS HIGH PRES MOVES E...CROSSING UPPER MI TONIGHT...LINGERING LAKE EFFECT SNOW SHOWERS AFFECTING KCMX WILL END TONIGHT. UNTIL THEN...EXPECT IFR VIS TO PREVAIL THIS AFTN. HOWEVER...AS IS TYPICAL FOR LAKE EFFECT...CONDITIONS WILL BE QUITE VARIABLE AT TIMES...RANGING FROM BRIEF LIFR TO BRIEF MVFR. EXPECT IMPROVEMENT TO MVFR AT KCMX THIS EVENING...THEN VFR OVERNIGHT. AT KIWD...LAST OF THE STRATOCU/MVFR CIGS OFF THE LAKE SHOULD EXIT WITHIN THE NEXT HR OR SO...LEAVING VFR CONDITIONS TO PREVAIL THRU THE REMAINDER OF THE FCST PERIOD. AT KSAW...THERE MAY BE OCNL MVFR CIGS THIS AFTN. OTHERWISE...VFR CONDITIONS WILL BE THE RULE THRU THE FCST PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 401 PM EST SAT FEB 13 2016 AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR TONIGHT...WINDS WILL DIMINISH AND BECOME LIGHT UNDER 15KT FOR A TIME. ONCE THIS HIGH SHIFTS E OF THE AREA...S WINDS WILL INCREASE UP TO 25-30KT SUN INTO MON MORNING UNDER THE TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING HIGH AND AN APPROACHING LOW PRES TROF IN THE PLAINS. THERE COULD BE A FEW GALE FORCE GUSTS SUN NIGHT OVER THE E HALF OF THE LAKE. ALTHOUGH WINDS WILL DIMINISH LATER MON...ANOTHER ROUND OF STRONG NNW WINDS UP TO 30KT WILL DEVELOP TUE/TUE NIGHT FOLLOWING A COLD FRONTAL PASSAGE. NOT OUT OF THE QUESTION THERE COULD BE A FEW GALE FORCE GUSTS. WINDS WILL THEN DIMINISH WED WITH ARRIVAL OF ANOTHER HIGH PRES RIDGE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 6 PM EST THIS EVENING FOR MIZ006- 007-085. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ265>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
328 PM CST SAT FEB 13 2016 .DISCUSSION... Issued at 327 PM CST SAT FEB 13 2016 Main forecast challenges deal with weather type and headlines. The forecast area is really being split by wintry weather, both spatially and temporally, with snowfall in our northeast and light freezing drizzle in our south. The snowfall will likely start earlier (late this evening) than the freezing drizzle, which may hold off unto closer to sunrise. Strong isentropic ascent will eventually saturate the lowest several thousand feet of the atmosphere in north central to northeastern Missouri. Have delayed onset of snow several hours based on forecast soundings,the large temperature/ dewpoint depressions on surface observations and the relatively high cloud bases. Forecast soundings for the Kirksville area saturate around midnight or perhaps a little later. Have waited until then to increase PoPs into the likely range. Snow amounts in our northeastern zones are still expected to be in the 1" to as much as 3" range in Schuyler County. After coordination with neighbors, have issued a winter weather advisory for our extreme northeastern counties, including the Kirksville area. The other aspect of this wintry episode is the potential for freezing drizzle in the southern half of the forecast area. Confidence in this is quite a bit lower than with the snowfall in the northeast. First, the lowest several thousand feet never really saturate. Second, by the time saturation begins to lower, the warm front lifts through, warms the surface above freezing and desaturates the sounding aloft. So there really only looks like a marginal potential for several hours when lift is maximized coincident with the greatest amount of saturation. This seems to be around the 12Z time frame +/- an hour or two. However, freezing drizzle can have a major impact on travel as it can be deceptive in it`s ability to slicken roads. So it`ll be important for people who have to travel Sunday morning to understand that roads may be slick. But for now, confidence just isn`t high enough to issue an advisory at this time. Another clipper system will move through Monday night/ Tuesday morning. Forecast soundings show the lowest several thousand feet to be above freezing, even all the way into the northeastern portions of the forecast area. So for snow, the wave should have little impact with regards to wintry weather in the forecast area and we should see just rain or perhaps a rain/snow mix in our northern zones. The rest of the forecast looks quiet regarding precipitation. An upper level ridge will spread east with low level flow out of the south. This will help temperatures soar to well above normal levels by Thursday into Friday. Highs may be in the 70s in parts of the forecast area Thursday and potentially into Friday. && .AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon) Issued at 1118 AM CST SAT FEB 13 2016 VFR conditions with ceilings between 5 and 8 thousand feet are expected through the rest of the afternoon and into the overnight. Late tonight, ceilings are expected to lower to MVFR and possibly into the 1500 to 2000 ft range. There is also a chance for light freezing drizzle across eastern Kansas and western Missouri late tonight and early tomorrow morning. The most likely timing for this seems to be centered around 12Z give or take a few hours. Temperatures are expected to warm above freezing late Sunday morning with lower levels drying out, ending the potential for freezing drizzle. && .EAX Watches/Warnings/Advisories... KS...NONE. MO...Winter Weather Advisory from 9 PM this evening to 6 PM CST Sunday for MOZ008-017-025-033. && $$ DISCUSSION...CDB AVIATION...CDB
  [top] Area Forecast Discussion National Weather Service SPRINGFIELD MO 244 PM CST SAT FEB 13 2016 ...A Light Wintry Mix Late Tonight into Early on Sunday...Much Warmer Weather Returns Next Week... .SHORT TERM...(This Evening through Sunday) Issued at 0217 PM CST SAT FEB 13 2016 Cold and dry air has invaded much of the Missouri Ozarks region this afternoon. There are some areas across central Missouri that has barely reached 20 degrees. The main story for tonight into early tomorrow will be the threat of a light wintry mix and freezing drizzle. The latest Hi-Res forecast models all indicate very light precip to begin to develop between midnight and 3 am across western and southern Missouri. The latest RUC and HRRR even shows some convective like precip which indicates pockets of sleet possible. The overall message for late tonight into tomorrow morning is we are expecting only very light amounts of a light wintry mix but could be impacts on roads and travel in the morning. Ground and road temperatures have had time to cool down over the past 24 hours. The freezing line will settle somewhere near the Missouri and Kansas border tonight before it begins to retreat eastward during the morning hours. There will be very light precip falling across the Missouri Ozarks with the better potential for higher amounts across the eastern Ozarks. Freezing drizzle and some light sleet is expected across the western half of the area and a wintry mix with some light snow is expected across the eastern half of the area early on. This will slowly transition to just a cold light rain or drizzle late tomorrow morning into the early afternoon from west to east. We will issue a winter weather advisory for light amounts and possible travel impacts in the morning. Like what we saw a few weeks ago...it does not take much freezing drizzle to cause big travel problems in the Ozarks region. All areas in the advisory area can expect a very light glaze of ice possible. A dusting of light sleet or light snow can be expected east of Highway 65 with up to an inch of snow possible from the Highway 63 corridor and eastward. Most area will warm up above freezing by Sunday afternoon with some areas out across far western Missouri near 50. .LONG TERM...(Sunday Night through Saturday) Issued at 0217 PM CST SAT FEB 13 2016 There may be some fog developing late Sunday night into Monday morning. This will need to be watched because temperatures again may be around or slightly below freezing. The best potential for fog will be along and south of the I-44 corridor across southern Missouri. Milder temperatures return on Monday. A quick moving upper level system across the Midwest on Tuesday may bring a few more clouds and a slight chance of showers across central Missouri and the eastern Ozarks. Decent upper Level ridging will develop across the central U.S. for the middle and end of next week. This will allow for way above average temperatures for the region. Highs will be in the 60s and possible lower 70s. A preview of Spring is coming next week. && .AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon) Issued at 1156 AM CST SAT FEB 13 2016 An upper level disturbance will slide southeast across the region from late tonight into Sunday. This system will bring a variety of aviation impacts. Ceilings will lower starting late tonight with MVFR expected during the predawn hours. We are also expecting a light wintry mix of precipitation to develop late tonight, however precipitation onset time remains in question due to a very dry airmass which is currently in place. We have therefore handled this uncertainty with TEMPO groups. Low level wind shear conditions are also expected from late tonight into early Sunday morning. By sunrise, precipitation should be ongoing over most areas with freezing drizzle being the main precipitation type. Precipitation will begin to diminish around Joplin and then Springfield by late morning with temperatures warming to around the freezing mark by midday. Ceilings will remain in the MVFR category. && .SGF Watches/Warnings/Advisories... MO...Winter Weather Advisory from 3 AM to noon CST Sunday for MOZ055>058-066>071-077>083-088>098-101>106. KS...NONE. && $$ SHORT TERM...Griffin LONG TERM...Griffin AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1230 PM CST SAT FEB 13 2016 .UPDATE... ISSUED AT 1215 PM CST SAT FEB 13 2016 ADDED A FREEZING RAIN ADVISORY FOR WILLIAMS AND DIVIDE COUNTY THROUGH 00Z TONIGHT AND EXPANDED THE WINTER WEATHER ADVISORY INTO BURKE...MOUNTRAIL...AND RENVILLE COUNTIES WITH THIS UPDATE. LATEST OBSERVATIONS OUT OF NORTHEASTERN MONTANA AND FORECAST SOUNDINGS NEAR WILLISTON SUPPORT A PERIOD OF FREEZING RAIN AND SNOW MIX IN THE NORTHWEST THROUGH LATE AFTERNOON. BY EVENING...PRECIPITATION SHOULD TRANSITION TO ALL SNOW. THE FORECAST APPEARS ON TRACK FOR THE REST OF THE AREA. UPDATE ISSUED AT 947 AM CST SAT FEB 13 2016 NO SIGNIFICANT CHANGES WERE NEEDED FOR THIS UPDATE. DID INCREASE PRECIPITATION CHANCES OVER THE WEST AND CENTRAL THROUGH 18Z...AS MULTIPLE OBSERVATIONS ARE COMING IN WITH LIGHT SNOW WHERE THERE HAVE BEEN LITTLE TO NO RADAR RETURNS. THINKING REMAINS THE SAME ON WINTER WEATHER HEADLINES AS WE ENTER A HOLDING PATTERN...WITH LOW PRESSURE NOW DEVELOPING OVER SOUTHERN SASKATCHEWAN AND NORTHERN WYOMING. UPDATE ISSUED AT 701 AM CST SAT FEB 13 2016 EXPANDED THE WINTER WEATHER ADVISORY INTO THE NORTH CENTRAL AND TURTLE MOUNTAINS AREA FOR THIS AFTERNOON THROUGH TONIGHT WITH THIS UPDATE. THE FULL 00 AND 06 UTC DETERMINISTIC AND ENSEMBLE SUITES AND THE 08-11 UTC HRRR AND RAP ITERATIONS ALL SUPPORT THE POTENTIAL FOR MODERATE SNOWFALL ACCUMULATIONS ACROSS THE NORTH CENTRAL AND TURTLE MOUNTAINS AREA THIS AFTERNOON THROUGH TONIGHT. OVERALL...A CONSENSUS OF THESE SOLUTIONS SUPPORTS GREATER QPF THAN THE PREVIOUS FORECAST OVER MOST OF THE CWA THIS AFTERNOON THROUGH TONIGHT...LEADING TO GREATER SNOWFALL TOTALS. OBSERVED TRENDS ACROSS MONTANA THIS MORNING AND THE 12 UTC SUITE WILL HAVE TO BE CLOSELY EVALUATED AS SOME LOCATIONS ACROSS CENTRAL NORTH DAKOTA HAVE THE POTENTIAL TO APPROACH WARNING LEVEL SNOWFALL AS DEPICTED IN 00 AND 06 UTC SUITES. HEAVY SNOWFALL RATES ARE POSSIBLE GIVEN STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH THE POTENT SHORTWAVE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM CST SAT FEB 13 2016 THE FOCUS OF THE SHORT TERM FORECAST IS A WINTRY MIX IN WESTERN ND AND SNOWFALL IN CENTRAL ND. A FREEZING RAIN ADVISORY WILL BE ISSUED FOR SOUTHWESTERN NORTH DAKOTA...AND A WINTER WEATHER ADVISORY FOR THE SOUTH CENTRAL. CURRENTLY...ARCTIC HIGH PRESSURE EXTENDED FROM MANITOBA TO IOWA...WITH LOW PRESSURE ALONG THE LEE OF THE ROCKIES. TEMPERATURES HAVE BEEN RISING ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY THIS MORNING. LOWS RANGED FROM 5 TO 20 BELOW ZERO FROM THE TURTLE MOUNTAINS TO THE JAMES RIVER VALLEY...BUT WERE CURRENTLY AROUND 5 BELOW ZERO. FARTHER WEST TEMPERATURES HAVE BEEN FAIRLY STEADY OR RISING...WITH TEENS IN THE FAR WEST ALL NIGHT. WARM ADVECTION FROM THE WEST...ACCOMPANIED BY ISENTROPIC LIFT...WAS ASSOCIATED WITH A BAND OF LIGHT SNOW THAT EXTENDED FROM WILLISTON AND STANLEY IN THE NORTHWEST TO GRANT AND SIOUX COUNTIES IN THE SOUTH CENTRAL PART OF THE STATE. THE LATEST ITERATIONS OF THE HIGHRES MODELS INDICATE THIS BAND OF LIGHT SNOW WEAKENING/DISSIPATING AS IT PROGRESSES EASTWARD THIS MORNING. A SIGNIFICANT UPPER LEVEL SHORTWAVE IS FORECAST TO MOVE EAST ACROSS IDAHO AND MONTANA THIS MORNING...THEN MOVE SOUTHEAST ACROSS THE DAKOTAS THIS AFTERNOON AND TONIGHT. PRECIPITATION IS EXPECTED TO DEVELOP BEFORE NOON IN THE SOUTHWEST AND AROUND NOON IN CENTRAL NORTH DAKOTA ASSOCIATED WITH THIS SHORTWAVE. THE 00Z AND 06Z HIGHRES MODELS SUGGEST STRONG WARM ADVECTION CONTINUING IN THE SOUTHWEST...WITH MAX TEMPERATURES ALOFT AROUND +3 TO +5 C. THUS THE THERMAL PROFILES SUGGEST A MIX OF LIGHT FREEZING RAIN...SLEET...SNOW...OR RAIN AT TIMES THIS AFTERNOON. AS THE SHORTWAVE PASSES THROUGH...COLD ADVECTION WILL ENSUE AND PRECIPITATION WILL LIKELY CHANGE TO LIGHT SNOW THIS EVENING IN SOUTHWESTERN NORTH DAKOTA. IN SOUTH CENTRAL NORTH DAKOTA...THE THERMAL PROFILES SUGGEST MAINLY SNOW...BUT A MIX OF SLEET OR FREEZING RAIN IS POSSIBLE AS WELL - ESPECIALLY DURING THE AFTERNOON. MODELS ARE NOT IN THE BEST AGREEMENT REGARDING SNOW AMOUNTS...BUT CONSENSUS SNOW AMOUNTS ARE IN THE 3-5 INCH RANGE BY DAYBREAK SUNDAY MORNING. THUS CONFIDENT ON AT LEAST WINTER WEATHER ADVISORY FOR THE SOUTH CENTRAL. SOME OF THE LATEST ITERATIONS OF THE SHORT TERM MODELS ARE HINTING AT HIGHER SNOW AMOUNTS...BUT CONFIDENCE IS LOWER - MAINLY BECAUSE IF THERMAL PROFILES ARE WARMER/COOLER THAN FORECAST THIS WILL IMPACT SNOW AMOUNTS. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 346 AM CST SAT FEB 13 2016 ABOVE NORMAL TEMPERATURES HIGHLIGHT THE EXTENDED FORECAST. THE 00 UTC AND INCOMING 06 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN GOOD AGREEMENT ON A BROAD...LOW AMPLITUDE UPPER LEVEL RIDGE BUILDING ACROSS THE CENTRAL CONUS THROUGHOUT THE EXTENDED FORECAST PERIOD. THUS...ABOVE NORMAL HIGH TEMPERATURES IN THE 30S AND 40S ARE EXPECTED OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THROUGHOUT THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1215 PM CST SAT FEB 13 2016 FAST MOVING LOW PRESSURE WAS DEVELOPING OVER SOUTHEASTERN MONTANA. THIS SYSTEM WILL BRING FROZEN PRECIPITATION TO MUCH OF THE WESTERN AND CENTRAL PARTS OF NORTH DAKOTA THROUGH THE AFTERNOON AND OVERNIGHT HOURS. PRECIPITATION WILL BEGIN AS A MIX OF RAIN...FREEZING...AND SNOW IN THE WEST THIS AFTERNOON...EVENTUALLY TRANSISTIONING TO ALL SNOW BY TONIGHT. MFVR CEILINGS AND VISIBILITES WILL BE COMMON ACROSS ALL SITES...WITH PERIODS OF IFR/LIFR CONDITIONS POSSIBLE WITHIN ANY HEAVIER SNOW BANDS. WINDS OF 15-20 KNOTS WILL GENERALLY COME FROM THE SOUTH THIS AFTERNOON...TRANSITIONING WEST/NORTHWESTERLY BY THE OVERNIGHT HOURS. PRECIPITATION WILL BEGIN TO DIMINISH EARLY SUNDAY MORNING. && .BIS WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR NDZ002>005-010>013-019>023-025-034>037-042-045>048-050-051. FREEZING RAIN ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT FOR NDZ017-018-031>033-040-041-043-044. FREEZING RAIN ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ001- 009. && $$ UPDATE...ZH SHORT TERM...JV LONG TERM...AYD AVIATION...ZH
AREA FORECAST DISCUSSION
NWS NORMAN OK
1207 PM CST SAT FEB 13 2016 .AVIATION... GUSTY SOUTHEAST WINDS WILL PREVAIL THROUGH THE EVENING WITH A FEW HIGH CLOUDS. MOISTURE RETURN LATE THIS EVENING AND OVERNIGHT WILL RESULT IN AT LEAST MVFR CEILINGS...ESPECIALLY AFTER 6Z. A LITTLE UNSURE HOW FAR LOW CEILINGS WILL EXTEND IN WEST CENTRAL AND NORTHWEST OKLAHOMA. A FRONT WILL MOVE ACROSS ALL TAF SITES BY 18Z SUNDAY WITH NORTH TO NORTHWEST WINDS BEHIND THE FRONT. IFR CEILINGS MAY DEVELOP JUST AHEAD AND SHORTLY BEHIND THE FRONTAL PASSAGE. WILL ALSO MENTION THE POTENTIAL FOR FOG WITH BETTER CHANCES IN AND AROUND OKC/OUN. && .PREV DISCUSSION... /ISSUED 1050 AM CST SAT FEB 13 2016/ DISCUSSION... CIRCULATION FROM COLD HIGH PRESSURE OVER IOWA WILL KEEP NORTH CENTRAL AND CENTRAL OKLAHOMA THE COOLEST THIS AFTERNOON. SURFACE WINDS HAVE ALREADY SHIFTED TO A EAST AND SOUTHEAST DIRECTION THIS MORNING...AND SHOULD KEEP A SOUTHEAST COMPONENT DURING THE AFTERNOON. THE HRRR AND RAP APPEAR A LITTLE WARM WITH HIGHS THIS AFTERNOON (SLIGHTLY VEERED FLOW)...BUT HAVE TRENDED A LITTLE WARMER IN SOME AREAS. PREV DISCUSSION... /ISSUED 604 AM CST SAT FEB 13 2016/ DISCUSSION... AVIATION... EAST WINDS WILL TURN SOUTH TODAY AND INCREASE AHEAD OF A SURFACE TROUGH. MVFR CEILINGS ARE EXPECTED TO MOVE NORTHWARD TONIGHT FROM TEXAS WHERE LOWER-LEVEL MOISTURE IS HIGHER. PREV DISCUSSION... /ISSUED 324 AM CST SAT FEB 13 2016/ DISCUSSION... SLIGHTLY COOLER WEATHER IS EXPECTED TODAY IN THE WAKE OF THE AIRMASS THAT IS DRIFTING OFF TO THE NORTHEAST OF OKLAHOMA. HOWEVER, THE SUNDAY AND NEXT WEEK WILL SEE INCREASING WARMING TO THE POINT OF HOT BY THE LATER PART OF THE WEEK. BEFORE THAT, RAIN CHANCES CROSS THROUGH EASTERN AND SOUTHEASTERN OKLAHOMA SUNDAY AND EARLY MONDAY WHEN SEVERAL SURFACE TROUGHS AND WEAK UPPER WAVES PASS BY. BEYOND THEN, NO PRECIPITATION IS EXPECTED THROUGH NEXT WEEK. THE MAIN WEATHER IMPACT WILL LIKELY BE INCREASED FIRE WEATHER POTENTIAL, ESPECIALLY THURSDAY WHEN GUSTY SOUTHWEST WINDS AND TEMPERATURES IN THE 70S AND 80S ARE EXPECTED. A WEAK FRONT IN THE WEEKEND WILL BRING LOWER, BUT STILL SEASONABLY HIGH TEMPERATURES. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 53 43 62 38 / 0 10 10 10 HOBART OK 55 44 63 36 / 0 0 0 0 WICHITA FALLS TX 62 48 68 40 / 0 0 0 10 GAGE OK 55 34 60 29 / 0 0 0 10 PONCA CITY OK 45 34 58 33 / 0 10 10 0 DURANT OK 56 46 62 44 / 0 10 20 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS NORMAN OK
1050 AM CST SAT FEB 13 2016 .DISCUSSION... CIRCULATION FROM COLD HIGH PRESSURE OVER IOWA WILL KEEP NORTH CENTRAL AND CENTRAL OKLAHOMA THE COOLEST THIS AFTERNOON. SURFACE WINDS HAVE ALREADY SHIFTED TO A EAST AND SOUTHEAST DIRECTION THIS MORNING...AND SHOULD KEEP A SOUTHEAST COMPONENT DURING THE AFTERNOON. THE HRRR AND RAP APPEAR A LITTLE WARM WITH HIGHS THIS AFTERNOON (SLIGHTLY VEERED FLOW)...BUT HAVE TRENDED A LITTLE WARMER IN SOME AREAS. && .PREV DISCUSSION... /ISSUED 604 AM CST SAT FEB 13 2016/ DISCUSSION... AVIATION... EAST WINDS WILL TURN SOUTH TODAY AND INCREASE AHEAD OF A SURFACE TROUGH. MVFR CEILINGS ARE EXPECTED TO MOVE NORTHWARD TONIGHT FROM TEXAS WHERE LOWER-LEVEL MOISTURE IS HIGHER. PREV DISCUSSION... /ISSUED 324 AM CST SAT FEB 13 2016/ DISCUSSION... SLIGHTLY COOLER WEATHER IS EXPECTED TODAY IN THE WAKE OF THE AIRMASS THAT IS DRIFTING OFF TO THE NORTHEAST OF OKLAHOMA. HOWEVER, THE SUNDAY AND NEXT WEEK WILL SEE INCREASING WARMING TO THE POINT OF HOT BY THE LATER PART OF THE WEEK. BEFORE THAT, RAIN CHANCES CROSS THROUGH EASTERN AND SOUTHEASTERN OKLAHOMA SUNDAY AND EARLY MONDAY WHEN SEVERAL SURFACE TROUGHS AND WEAK UPPER WAVES PASS BY. BEYOND THEN, NO PRECIPITATION IS EXPECTED THROUGH NEXT WEEK. THE MAIN WEATHER IMPACT WILL LIKELY BE INCREASED FIRE WEATHER POTENTIAL, ESPECIALLY THURSDAY WHEN GUSTY SOUTHWEST WINDS AND TEMPERATURES IN THE 70S AND 80S ARE EXPECTED. A WEAK FRONT IN THE WEEKEND WILL BRING LOWER, BUT STILL SEASONABLY HIGH TEMPERATURES. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 53 43 62 38 / 0 10 10 10 HOBART OK 55 44 63 36 / 0 0 0 0 WICHITA FALLS TX 62 48 68 40 / 0 0 0 10 GAGE OK 55 34 60 29 / 0 0 0 10 PONCA CITY OK 45 34 58 33 / 0 10 10 0 DURANT OK 56 46 62 44 / 0 10 20 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
201 PM PST SAT FEB 13 2016 .SYNOPSIS...A STRONG WARM FRONT IS SPREADING RAIN AND BREEZY CONDITIONS INTO SOUTHWEST WASHINGTON AND NORTHWEST OREGON THIS AFTERNOON. RAIN WILL BECOME HEAVY AT TIMES...ESPECIALLY ALONG THE COAST AND IN THE HIGHER TERRAIN. SNOW LEVELS ARE STARTING OFF NEAR THE CASCADE PASSES...BUT ARE EXPECTED TO RISE TONIGHT AS WARMER AIR MOVES IN. THE FRONTAL ZONE WILL LINGER OVER THE AREA SUNDAY...THEN LIFT NORTH SUNDAY NIGHT AND MONDAY FOR DECREASING RAIN. HIGH PRESSURE WILL BRING DRIER WEATHER LATER MONDAY INTO TUESDAY...ESPECIALLY FOR SOUTHERN ZONES. AN UPPER LEVEL TROUGH IS EXPECTED TO BRING COOLER AND SHOWERY WEATHER LATER WEDNESDAY INTO THURSDAY...WITH SNOW POSSIBLE FOR THE CASCADE PASSES AND ABOVE. && .SHORT TERM...TONIGHT THROUGH TUESDAY...NWS DOPPLER RADAR SHOWS RAIN SPREADING EASTWARD ACROSS THE FORECAST AREA THIS AFTERNOON...MAINLY NORTH OF A LINCOLN CITY TO SALEM LINE. THIS IS ASSOCIATED WITH A POTENT PACIFIC FRONTAL SYSTEM WHICH WILL PUSH A WARM FRONT ACROSS THE FORECAST AREA TONIGHT. LOOKING AT THE BIGGER PICTURE...THIS FRONTAL SYSTEM HAS A DECENT MOISTURE TAP ALL THE WAY BACK TO THE SUBTROPICAL LATITUDES NEAR THE DATELINE. BLENDED PRECIPITABLE WATER VALUES SHOW 1.2 INCH OR HIGHER WITHIN THIS MOISTURE PLUME AS FAR EAST AS 130W. 12Z NAM/GFS SUGGEST PW VALUES AROUND 1 INCH REACHING OUR FORECAST AREA THIS EVENING...COUPLED WITH OROGRAPHICALLY FAVORABLE W-SW WINDS OF 40-50 KT AT 850 MB. THIS SHOULD YIELD A PERIOD OF FAIRLY HEAVY RAINFALL FOR THE COAST AND HIGHER TERRAIN... ESPECIALLY NORTHERN ZONES WHERE 2-4 INCHES OF RAIN ARE POSSIBLE BY SUNDAY. INLAND VALLEYS WILL SEE LESS...RANGING FROM AROUND 0.50 INCH SOUTH OF SALEM TO AROUND 1 INCH IN THE PDX METRO. 12Z GFS SHOWS THE BEST ISENTROPIC LIFT MOVING THROUGH BY MIDNIGHT TONIGHT. AFTER THAT FORCING MOVES EAST...THE WILLAMETTE VALLEY WILL LIKELY BE HEAVILY RAIN SHADOWED IN LOW-LEVEL WESTERLY FLOW LATER TONIGHT INTO SUNDAY. SNOW AMOUNTS REMAIN A CHALLENGING FORECAST FOR THE CASCADES WITH THIS SYSTEM. OFTEN TIMES...LEFTOVER COLD AIR...WET-BULB EFFECTS AND LATENT HEAT PROCESSES WILL HOLD ON TO LOWER SNOW LEVELS MOUNT HOOD NORTHWARD A BIT LONGER THAN MODELS EXPECT. HOWEVER THIS DOES NOT APPEAR TO BE ONE OF THOSE SCENARIOS AS FAIRLY STRONG WARM ADVECTION WILL BE MOVING IN ON THE 40-50 KT W-SW 850-700 MB FLOW LATER TONIGHT. SOME WET SNOW IS POSSIBLE FOR THE PASSES THIS AFTERNOON INTO THIS EVENING...BUT ACCUMULATIONS SHOULD BE LIGHT. HIGHER SKI RESORT ELEVATIONS LOOK MORE LIKELY TO SEE 5-10 INCHES BEFORE SNOW LEVELS SKYROCKET TO 7000 FEET SUNDAY MORNING. IF SNOW LEVELS REMAIN LOWER THAN EXPECTED...SNOW ACCUMULATIONS COULD BE SUBSTANTIALLY HIGHER GIVEN THE HEAVY QPF THAT IS EXPECTED. HOWEVER...AM FAIRLY CONFIDENT THAT THE CHANGEOVER WILL BE QUICK LATER TONIGHT OR SUNDAY MORNING. NOT EXPECTING TO CHANGE MUCH WITH THE EXISTING WINTER WX ADVISORY FOR SNOW...THOUGH WILL PROBABLY ADD SOME WORDING TO SUGGEST THE GREATEST ACCUMULATIONS WILL LIKELY REMAIN UP IN THE HIGHER SKI RESORT ELEVATIONS. THE HEAVY RAINFALL MAY CAUSE SOME MINOR HYDROLOGIC ISSUES...MAINLY FOR CREEKS AND SMALL STREAMS DRAINING OUT OF THE COAST RANGE AND CASCADES. THE GRAYS RIVER IN WAHKIAKUM COUNTY IS NOTORIOUSLY FAST- RESPONDING...SO 2-4 INCHES OF RAIN IN A 24 HOUR PERIOD MAY PUSH IT CLOSE TO BANKFULL. WILL BE KEEPING A CLOSE EYE ON THIS RIVER AMONG OTHERS AS RAIN INCREASES LATER TODAY AND TONIGHT...BUT SIGNIFICANT MAIN STEM RIVER FLOODING IS NOT EXPECTED AT THIS TIME. UPPER LEVEL RIDGING WILL BEGIN BUILDING IN FROM THE SW SUNDAY...BUT WEAK SHORTWAVES WILL LIKELY RIDE OVER THE TOP OF THE RIDGE AND REMAIN INTACT TO KEEP SOME RAIN IN THE PICTURE THROUGH SUN EVENING. DRYING TREND IS EXPECTED MON/TUE AS THE UPPER RIDGE SHOVES THE MAIN BAROCLINIC ZONE NORTHWARD INTO WA/BC. SW WA MAY REMAIN CLOSE ENOUGH TO THE FRONTAL ZONE TO KEEP SOME RAIN OR DRIZZLE AROUND...BUT AREAS PDX METRO SOUTHWARD SHOULD BE MAINLY DRY MON/TUE. STRENGTHENING INVERSIONS MAY PROMOTE NIGHT AND MORNING FOG... ESPECIALLY SOUTH OF SALEM WHERE SKIES HAVE THE BEST CHANCE OF CLEARING. ANY FOG THAT DOES DEVELOP MAY BE STUBBORN. DID NOT FACTOR THIS INTO MON/TUE MAX TEMP FORECASTS YET...AS THERE REMAINS A GOOD DEAL OF UNCERTAINTY AS TO IF AND WHERE FOG WILL DEVELOP. WEAGLE .LONG TERM...TUESDAY NIGHT THROUGH FRIDAY...THE UPPER RIDGE RESPONSIBLE FOR THE DRYING TREND MON/TUE WILL SHIFT EAST MIDWEEK... WITH MODELS SHOWING GOOD CONSENSUS IN BRINGING A WELL DEFINED UPPER TROUGH INTO THE PAC NW AND POSSIBLY CALIFORNIA WED NIGHT/THU. THIS WILL CAUSE RAIN CHANCES TO INCREASE LATER WED...WITH COOL AND SHOWERY WEATHER LINGERING INTO THU. AIR MASS WILL START OUT RATHER WARM WITH SNOW LEVELS WELL ABOVE THE CASCADE PASSES WED. COLDER AIR WILL MOVE IN WITH THE UPPER TROUGH...WITH SNOW LEVELS LOWERING TO 3000 TO 3500 FEET IN SHOWERS BY THURSDAY. EXPECT TEMPS TO DROP BACK TO NEAR NORMAL LATE WEEK AS A RESULT OF THE UPPER TROUGH...POSSIBLY EVEN A LITTLE BELOW NORMAL. MODELS SHOW DECENT AGREEMENT THAT THIS UPPER TROUGH WILL BE FOLLOWED BY A MORE PROGRESSIVE FRONTAL SYSTEM FOR MORE RAIN AND CASCADE SNOW FRI/FRI NIGHT. WEAGLE && .AVIATION...WARM-FRONTAL PRECIP BEGINNING TO SPREAD INTO THE S WASHINGTON AND N OREGON COAST EARLY THIS AFTERNOON. VFR ACROSS THE AREA...EXCEPT AREAS OF MVFR ALONG THE COAST. FLIGHT CONDITIONS ALONG THE COAST DETERIORATE THROUGH THE AFTERNOON AND EARLY EVENING...DROPPING TO IFR BY 00Z SUN. MVFR COVERAGE TO INCREASE OVER THE INTERIOR LOWLANDS AFTER 00Z SUN. INTERIOR VALLEYS MAY SEE MORE VFR OVERNIGHT THROUGH SUN DUE TO RAIN-SHADOW EFFECTS. STRONG 850 MB WEST FLOW WILL RESULT IN ENHANCED OROGRAPHIC LIFT OVER THE HIGHER TERRAIN...RESULTING IN MOUNTAIN OBSCUREMENT AND IFR OR WORSE FLIGHT CONDITIONS. KPDX AND APPROACHES...VFR AT 21Z. CIGS WILL CONTINUE TO LOWER THROUGH THE AFTERNOON AND EARLY EVENING...WITH MVFR CONDITIONS LIKELY AFTER 02Z SUN...ESPECIALLY ALONG WRN APPROACHES. S WIND SHOULD ALLOW FOR LONGER-DURATION VFR CONDITIONS OVERNIGHT THROUGH SUN. WEISHAAR && .MARINE...WIND GUSTS ON THE EDGE OF GALE FORCE OVER THE NRN OUTER WATERS EARLY THIS AFTERNOON. THE 14Z RUC RUN WAS A LITTLE STRONGER COMPARED TO THE 12Z NAM. GALE FORCE WIND GUSTS OVER THE OUTER NRN WATERS THROUGH 06Z SUN. HELD ON TO THEM A LITTLE LONGER OVER THE NRN INNER WATERS...EXTENDING THE GALE TO 08Z. WILL ALSO NEED TO WATCH THE NRN PART OF PZZ255 AND PZZ275 AS GUSTS COULD TOUCH GALE FORCE TONIGHT. MODELS IN DECENT AGREEMENT SHOWING SMALL CRAFT ADVISORY SPEEDS LATE TONIGHT THROUGH EARLY SUN AFTERNOON. 12Z NAM BOUNDARY LAYER WIND SPEEDS A LITTLE STRONGER 18Z SUN COMPARED TO THE GFS. WIND SPEEDS EASE A BIT MON AS THE WARM FRONT LIFTS N...REDUCING THE SURFACE GRADIENT. BASICALLY WENT WITH THE GFS FOR WIND MON THROUGH TUE NIGHT. MODEL DIFFERENCES BECOME GREATER WED THROUGH THU REGARDING THE NEXT SIGNIFICANT WEATHER SYSTEM. THE ECMWF SEEMS TO BE MORE CONSISTENT...SHOWING POSSIBLE GALES LATE WED THROUGH EARLY THU MORNING. A LONG PERIOD NW SWELL WILL MAINTAIN SEAS 12 TO 15 FT THROUGH TONIGHT AS THE WIND WAVE COMPONENT INCREASES. SEAS WILL SUBSIDE TO AROUND 10 FT SUN AFTERNOON. LATEST ENP RUN HAS SEAS INCREASING TO NEAR 15 FT LATE NEXT WEEK AND POSSIBLY NEAR 20 FT NEXT WEEKEND. WANT TO SEE A FEW MORE RUNS BEFORE GOING THAT HIGH. CAPPED SEAS TO AROUND 15 FT FOR NOW. WEISHAAR && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR NORTHERN OREGON CASCADES. WA...WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR SOUTH WASHINGTON CASCADES. PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM. SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM PST SUNDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 AM PST SUNDAY. GALE WARNING UNTIL MIDNIGHT PST TONIGHT FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 10 NM. && $$ 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 PORTLAND OR
1009 AM PST SAT FEB 13 2016 .SYNOPSIS...A STRONG WARM FRONT WILL SPREAD INCREASING RAIN AND BREEZY CONDITIONS INTO SOUTHWEST WASHINGTON AND NORTHWEST OREGON THIS AFTERNOON AND TONIGHT...WITH RAIN HEAVY AT TIMES. SNOW LEVELS WILL START NEAR THE CASCADE PASSES TODAY...BUT SHOULD RISE TONIGHT AS WARMER AIR MOVES IN. THE FRONTAL ZONE WILL LINGER OVER THE AREA SUNDAY...THEN LIFT NORTH SUNDAY NIGHT AND MONDAY FOR DECREASING RAIN. HIGH PRESSURE WILL BRING DRIER WEATHER LATER MONDAY INTO TUESDAY... ESPECIALLY FOR SOUTHERN ZONES. AN UPPER LEVEL TROUGH WILL BRING COOLER AND SHOWERY WEATHER LATER WEDNESDAY INTO THURSDAY...WITH SNOW POSSIBLE FOR THE CASCADE PASSES AND ABOVE. && .MORNING UPDATE...NWS DOPPLER RADAR SHOWS WARM FRONTAL RAIN STARTING TO MOVE ONSHORE TILLAMOOK NORTHWARD...THE START OF WHAT WILL BE A VERY WET PERIOD WHICH SHOULD LAST INTO SUNDAY. LOOKING AT THE BIGGER PICTURE...THIS FRONTAL SYSTEM HAS A DECENT MOISTURE TAP ALL THE WAY BACK TO THE SUBTROPICAL LATITUDES NEAR THE DATELINE. BLENDED PRECIPITABLE WATER VALUES SHOW 1.2 INCH OR HIGHER WITHIN THIS MOISTURE PLUME AS FAR EAST AS 135W. 12Z NAM/GFS SUGGEST PW VALUES AROUND 1 INCH REACHING OUR FORECAST AREA THIS EVENING...COUPLED WITH OROGRAPHICALLY-FAVORABLE W-SW WINDS OF 40-50 KT AT 850 MB. THIS SHOULD YIELD A PERIOD OF FAIRLY HEAVY RAINFALL FOR THE COAST AND HIGHER TERRAIN...ESPECIALLY NORTHERN ZONES WHERE 2-4 INCHES OF RAIN ARE POSSIBLE BY SUNDAY. INLAND VALLEYS WILL SEE LESS...RANGING FROM ABOUT 0.50 INCH NEAR EUGENE TO 0.75-1.50 INCH IN THE PDX METRO. 12Z GFS SHOWS THE BEST ISENTROPIC LIFT MOVING THROUGH BY MIDNIGHT TONIGHT...AFTER THAT THE WILLAMETTE VALLEY IS LIKELY TO BE HEAVILY RAIN SHADOWED IN LOW-LEVEL WESTERLY FLOW LATER TONIGHT INTO SUNDAY. SNOW AMOUNTS WILL BE TRICKY FOR THE CASCADES WITH THIS SYSTEM. OFTEN TIMES...LEFTOVER COLD AIR...WET-BULB EFFECTS AND LATENT HEAT PROCESSES WILL HOLD ON TO LOWER SNOW LEVELS MOUNT HOOD NORTHWARD A BIT LONGER THAN MODELS EXPECT. HOWEVER THIS DOES NOT APPEAR TO BE ONE OF THOSE SCENARIOS AS FAIRLY STRONG WARM ADVECTION WILL BE MOVING IN ON THE 40-50 KT W-SW 850-700 MB FLOW LATER TONIGHT. THERE WILL PROBABLY BE SOME WET SNOW AT THE PASSES DURING THE ONSET OF PRECIPITATION THIS AFTERNOON INTO THIS EVENING...BUT THIS SHOULD CHANGE TO RAIN BY SUNDAY MORNING. HIGHER SKI RESORT ELEVATIONS LOOK MORE LIKELY TO SEE 5-10 INCHES BEFORE SNOW LEVELS SKYROCKET TO 7000 FEET SUNDAY MORNING. IF SNOW LEVELS REMAIN LOWER THAN EXPECTED... SNOW ACCUMULATIONS COULD BE SUBSTANTIALLY HIGHER GIVEN THE HEAVY QPF THAT IS EXPECTED. HOWEVER...AM FAIRLY CONFIDENT THAT THE CHANGEOVER WILL BE QUICK LATER TONIGHT OR SUNDAY MORNING. CURRENT WINTER WX ADVISORY FOR SNOW APPEARS TO HANDLE ALL THIS WELL AND WILL NOT BE MAKING ANY CHANGES FOR THE MORNING PACKAGE. THE HEAVY RAINFALL MAY CAUSE SOME MINOR HYDROLOGIC ISSUES...MAINLY FOR CREEKS AND SMALL STREAMS DRAINING OUT OF THE COAST RANGE AND CASCADES. THE GRAYS RIVER IN WAHKIAKUM COUNTY IS NOTORIOUSLY FAST- RESPONDING...SO 2-4 INCHES OF RAIN IN A 24 HOUR PERIOD MAY PUSH IT CLOSE TO BANKFULL. WILL BE KEEPING A CLOSE EYE ON THIS RIVER AMONG OTHERS AS RAIN INCREASES LATER TODAY AND TONIGHT. WEAGLE /PREV DISC ISSUED 339 AM PST SAT FEB 13 2016/ .SHORT TERM...THE UPPER TROUGH ASSOCIATED WITH THE FRONTAL SYSTEM FROM FRIDAY MOVED EASTWARD THROUGH SOUTHWEST WASHINGTON AND FAR NORTHWEST OREGON OVERNIGHT...PRODUCING SHOWERS OVER MUCH OF THE FORECAST AREA AND A FEW THUNDERSTORMS OVER THE NORTH COASTAL WATERS AND THE IMMEDIATE COAST. THIS ACTIVITY WILL CONTINUE DECREASING THIS MORNING. ATTENTION THEN TURNS TO THE WARM FRONT APPROACHING 130W EARLY THIS MORNING THAT WILL MOVE INTO THE FORECAST AREA THIS AFTERNOON AND REMAIN OVER THE AREA THROUGH MUCH OF SUNDAY. THE FIRST WAVE ALONG THIS WARM FRONT WILL SPREAD HEAVY RAIN INTO THE AREA THIS AFTERNOON AND THROUGH AT LEAST THIS EVENING...WITH BRISK WINDS AT THE COAST AND LOCALLY INLAND. THIS WAVE IS ACCOMPANIED BY 1.2 INCH PRECIPITABLE WATER VALUES AND 850 MB WINDS OF NEARLY 50 KT. THIS WAVE MOVES EAST OF THE AREA LATER SATURDAY NIGHT...BUT IS FOLLOWED BY ONE OR TWO MORE SLIGHTLY WEAKER WAVES THAT KEEP THE RAIN GOING THROUGH SUNDAY...THOUGH AT LESSER RAINFALL RATES. SNOW LEVELS WILL START OUT IN THE CASCADES BETWEEN 3500 AND 4500 FEET TODAY...AND WILL LINGER NEAR THE PASSES INTO TONIGHT. HAVE ISSUED A SNOW ADVISORY OF THE SOUTH WASHINGTON CASCADES FROM NOON UNTIL AFTER MIDNIGHT TONIGHT...ALSO THE NORTH OREGON CASCADES UNTIL 10 PM TONIGHT. THE SNOW LEVEL DRAMATICALLY RISES FROM SOUTH TO NORTH TONIGHT TO WELL ABOVE THE PASSES...TO WELL ABOVE 6000 FEET. RAINFALL AMOUNTS OF 4 TENTHS OF TO OVER 1 INCH ARE POSSIBLE THIS WEEKEND IN THE VALLEYS...WITH 2 TO 4 INCHES ALONG THE COAST AND IN THE COAST RANGE AND THE CASCADES. THIS SURGE OF RAIN SHOULD CAUSE MANY OF OUR FASTER RESPONDING RIVERS TO RISE RAPIDLY...PARTICULARLY THE GRAYS RIVER IN WAHKIAKUM COUNTY...BUT MAIN STEM RIVER FLOODING IS NOT ANTICIPATED. THE PERIOD WITH THE BEST CHANCE OF ANY URBAN TYPE FLOODING WOULD BE LATER TODAY AND THIS EVENING. THE WARM FRONT SHOULD MOVE MOSTLY NORTH OF OUR FORECAST AREA SUNDAY NIGHT AND MONDAY WITH DECREASING RAIN. AS WE GET INTO THE WARM SECTOR...WE COULD SEE TEMPS BACK INTO THE LOWER 60S AT LOWER ELEVATIONS MONDAY. TOLLESON .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS... MONDAY NIGHT THROUGH FRIDAY...SHORTWAVE RIDGING EARLY IN THE WEEK WILL ONCE AGAIN GIVE WAY TO A MORE ACTIVE WEATHER PATTERN DURING THE MIDDLE TO LATTER HALF OF NEXT WEEK. THE REMNANTS OF AN ATMOSPHERIC RIVER EVENT MAY DIP FAR ENOUGH SOUTH TO BRING SOME LIGHT RAIN TO THE REGION TUESDAY...BUT CONFIDENCE IS LOW. MODELS HAVE BEEN IN MUCH BETTER AGREEMENT THAT A SHORTWAVE TROUGH WILL SWING INTO THE WESTERN UNITED STATES AND BRING WET AND COOLER WEATHER WEDNESDAY INTO THURSDAY. AN ADDITIONAL STORM SYSTEM APPEARS POSSIBLE TOWARDS THE END OF NEXT WEEK. TEMPERATURES FOR THE MOST PART SHOULD REMAIN NEAR TO ABOVE NORMAL WITH ANY BOUTS OF PRECIPITATION LOOKING TO REMAIN LIGHT ENOUGH THAT WE DO NOT FORESEE ANY MAJOR HYDROLOGIC ISSUES IN THE NEXT WEEK. AB/NEUMAN && .AVIATION...GENERALLY VFR AT 16Z...EXCEPT FOR AREAS OF MVFR ALONG THE S WASHINGTON AND FAR N OREGON COAST. THE NEXT WARM FRONT WILL IMPACT THE AREA LATE THIS AFTERNOON THROUGH SUNDAY. EXPECT CONDITIONS TO DETERIORATE WITH INCREASING RAIN FROM NW TO SE MID TO LATE AFTERNOON THROUGH TONIGHT...WITH IFR LIKELY ALONG THE COAST. INTERIOR VALLEYS MAY ACTUALLY REMAIN VFR THIS AFTERNOON THROUGH TONIGHT DUE TO SOME RAIN-SHADOW EFFECTS. STRONG 850 MB WEST FLOW WILL RESULT IN ENHANCED OROGRAPHIC LIFT OVER THE HIGHER TERRAIN...RESULTING IN MOUNTAIN OBSCUREMENT AND IFR OR WORSE FLIGHT CONDITIONS. KPDX AND APPROACHES...VFR PREVAILING TODAY...EXCEPT FOR POSSIBLE MVFR CIGS MID TO LATE-AFTERNOON THROUGH EARLY EVENING AS PRECIP INCREASES. S WIND SHOULD ALLOW FOR PRIMARILY VFR CONDITIONS LATER THIS EVENING THROUGH SUN MORNING. && .MARINE...WIND WILL INCREASE TODAY AS A WARM FRONT MOVES THROUGH THE WATERS. 14Z RUC RUN A LITTLE STRONGER COMPARED TO THE LATEST NAM. EXPECT SMALL CRAFT ADVISORY WIND SPEEDS TO RAMP UP TO GALE FORCE WIND GUSTS LATE THIS EVENING OVER THE N OUTER WATERS. GALES TO SPREAD INTO THE N INNER WATERS OVERNIGHT. GALES COULD LAST A LITTLE LONGER THAN CURRENT FORECAST IMPLIES...BUT WILL LOOK AT THAT MORE FOR THE AFTERNOON. RAMPED UP WIND SPEEDS A BIT SUN...WITH SOLID SMALL CRAFT ADVISORY SPEEDS EXPECTED. A LONG PERIOD NW SWELL WILL MAINTAIN 11 TO 13 FT SEAS TODAY THEN 12 TO 15 FT TONIGHT AS THE WIND WAVE COMPONENT INCREASES. SEAS WILL SUBSIDE TO AROUND 10 FT SUN AFTERNOON. LATEST ENP RUN HAS SEAS INCREASING TO NEAR 15 FT LATE NEXT WEEK. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM PST THIS EVENING FOR NORTHERN OREGON CASCADES. WA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 4 AM PST SUNDAY FOR SOUTH WASHINGTON CASCADES. PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM. SMALL CRAFT ADVISORY FOR WINDS FROM 1 PM THIS AFTERNOON TO 6 PM PST SUNDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM PST SUNDAY. GALE WARNING FROM 2 PM THIS AFTERNOON TO 10 PM PST THIS EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 10 NM. && $$ 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
1230 PM EST SAT FEB 13 2016 .SYNOPSIS... POLAR VORTEX OVR S QUEBEC WILL RAPIDLY LIFT NE BY LATE IN THE WEEKEND. A DEEPENING UPPER LVL TROF OVER THE CENTRAL CONUS WILL SPAWN A LOW PRES SYSTEM...WHICH WILL LIKELY TRACK NORTHWARD ACROSS EASTERN PA ON TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATED GRIDS FOR TEMPS/WINDS AND SNOW SHOWERS FOR QUICK LOOK AND ACCIDENT ON I78 IN LEBANON COUNTY WHICH HAS EM PERSONNEL WORKING ON SITE OF ACCIDENT. PREVIOUS: ARCTIC AIR MASS CONTINUES TO PUSH THROUGH THE REGION TODAY. TEMPERATURES WILL NOT MOVE TOO MUCH HIGHER THAN CURRENT VALUES. STRONG NORTHWEST WINDS AND TEMPERATURES IN JUST ABOVE ZERO IN THE NORTHWESTERN AREAS TO A BALMY MID-TEENS IN THE SOUTHEAST WILL PROVIDE FOR A VERY COLD DAY. WIND CHILLS BELOW ZERO OVER MOST OF THE REGION TODAY INTO SUNDAY. WIND GUSTS OF 25 TO 35 MPH HAVE BEEN OBSERVED SO FAR TODAY. COVER UP WELL IF OUTDOORS OVER THE NEXT 36 HOURS OF SO. RADAR AND SATELLITE IMAGERY SHOW HURON CONNECTION SNOW BANDS. ONE BAND MADE INTO STATE COLLEGE AROUND 9 AM FOR A QUICK COATING. THIS BAND IS MOVING TO THE SOUTHEAST AND COULD BRING LIGHT SNOW/FLURRIES TO LOWER SUSQUEHANNA VALLEY LATER THIS MORNING. MORE FOCUSED SNOW IS OVER SOUTHWEST MOUNTAINS. SNOW IN NORTHWESTER AREAS HAS BEEN QUITE LIMITED. THE NCAR 3KM EFS AND THE HRRR SEEM TO FOCUS SNOW IN SOUTHWEST MOUNTAINS AND HAVE LIMITED SNOW IN THEIR RESPECTIVE FORECASTS. THE AIR IS VERY DRY AND HAS NOT BEEN A PROLIFIC LAKE AND MOUNTAIN SNOW PRODUCER. HIGH RESOLUTION MODELS KEEP INDICATING THIS. HRRR AT TIMES SHOWS A POTENTIAL MODEST BAND IN NORTHWESTERN PA THIS EVENING. COLD WILL BE THE ISSUE OVER THE ENTIRE REGION. BEST ACCUMULATING SNOW POTENTIAL IN THE SOUTHWEST MOUNTAINS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... MODELS NOT VERY BIG IN SNOW OVERNIGHT INTO SUNDAY. SOME HINTS OF SNOW EARLY IN THE HRRR AND SREF IN SW MOUNTAINS. COMBINED WITH THE FALLING INVERSION HEIGHTS AHEAD OF APPROACHING HIGH...LES AND MOUNTAIN SNOW THREATS WILL DIMINISH. THE HIGH SHOULD DECOUPLE SOME AREAS OVERNIGHT AND WITH SNOW COVER A GOOD PERIOD OF RADIATIONAL COOLING IS POSSIBLE IN CENTRAL AND WESTERN AREAS. THE MASSIVE 1032 TO 1036 HIGH MOVES OVER THE REGION AND IS PARKED OVERHEAD BY MIDDAY SUNDAY. THIS SHOULD ENSURE THE WINDS DIE AND THE WINDCHILL ISSUE DIMINISH. BUT WILL STILL BE A VERY COLD VALENTINES AT LEAST OUTDOORS. THE EVENING SHOULD STILL HAVE NEAR IDEAL RADIATIONAL COOLING CONDITIONS. VERY COLD START TO THE OVERNIGHT PERIOD SUNDAY INTO MONDAY....BUT THE HIGH MOVES OFF FAST SUNDAY NIGHT. OVERNIGHT LOW SUNDAY LIKELY WILL BE EARLY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... *IMPACT WEATHER HIGHLIGHTS: POTENTIAL WINTER STORM EARLY NEXT WEEK. BULK OF MED RANGE GUIDANCE INDICATES THE LIKELIHOOD OF SOME LGT SNOW ARRIVING MONDAY...AS SFC HIGH DRIFTS OFF THE COAST AND MILDER SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS. HOWEVER...THE BIGGER CONCERN INVOLVES DIGGING UPPER TROF OVR THE MISS VALLEY AND ASSOC SFC LOW PRESSURE LIFTING UP THE APPALACHIANS. MDL SPREAD CONTINUES TO NARROW...WITH MOST RUNS TRACKING SFC LOW ACROSS EASTERN PA TUESDAY. THIS TRACK WOULD CERTAINLY FAVOR RAIN ACROSS EASTERN PA AND RAIN OR SNOW ACROSS WESTERN PA. GIVEN INHERENT MDL UNCERTAINTIES THIS FAR OUT...WILL MAINTAIN RAIN/SNOW IN THE FCST FOR MOST OF CENTRAL PA MON NIGHT-TUES. HAVE RAISED POPS INTO THE LIKELY CATEGORY BASED ON CONVERGING MDL SOLUTIONS. WILL ALSO HAVE TO WATCH FOR THE POSSIBILITY OF FLOODING ACROSS EASTERN PA...GIVEN RAINFALL AND SNOWMELT POTENTIAL. LATEST MDL ENSEMBLE RIVER FORECASTS USING NAEFS SUGGESTS MINOR FLOODING IS A POSSIBILITY ACROSS THE LOWER SUSQ VALLEY BY TUES. WPC ALSO HAS HIGHLIGHTED SE PA FOR A SLIGHT RISK OF FLOODING TUESDAY. NEAR TO ABOVE NORMAL TEMPS APPEAR LIKELY LATER NEXT WEEK...AS HEIGHTS ARE FORECAST TO RISE AND A PSBL LOW PRESSURE SYSTEM LIFTS THROUGH THE GREAT LAKES TO THE WEST OF PA. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... ARCTIC AIR HAS BROUGHT COLD TEMPERATURES AND STRONG GUSTY WINDS TO THE REGION. SNOW SQUALLS ARE COMMON IN THE WESTERN MOUNTAINS WITH IMPACTS ON KJST AND KBFD. SOME OF THE STRONGER LAKE STREAMERS AND SNOW SHOWERS HAVE MADE TO THE MARYLAND BORDER IN SOUTHEASTERN PA. SO SNOW AND BLOWING SNOW IS POSSIBLE WITH THE STRONG GUSTY WINDS. GOOD GUST SPREADS TOO WHICH AFFECT TAKEOFF/LANDINGS. GUSTS OVER 30KTS HAVE BEEN OBSERVED. IFR AND MVFR MOST OF WEST. VFR WITH TIME MVFR IN CENTRAL AREAS. MOSTLY VFR WITH TIMES MVFR WITH SNOW/BLOWING SNOW IN SOME PARTS OF SOUTHEAST TODAY. THE SNOW SHOWERS AND WINDS WILL DIMINISH THIS EVENING AND OVERNIGHT. THINGS SHOULD BE MUCH NICER SUNDAY...THOUGH A TAD COLD. NEED A HEATED JOY STICK. HIGH PRESSURE SUNDAY DRIFTS EAST OVERNIGHT SO THE PERIOD OF NICE WEATHER WITH VFR WILL BE SHORT LIVED AS CLOUDS AND POTENTIAL PRECIPITATION MOVE IN FOR MONDAY AND INTO TUESDAY. SNOW AND ASSORTED WINTRY PRECIPITATION WILL LIKELY AFFECT FLYING MONDAY INTO TUESDAY. OUTLOOK... SUN...NO SIG WX EXPECTED MAINLY VFR. MON...WIDESPREAD RESTRICTIONS DEVELOP WITH SNOW DEVELOPING. MON NIGHT AND TUE...SNOW LIKELY WRN HALF OF PENN...WITH RAIN AND/OR SNOW IN THE SE. WIDESPREAD RESTRICTIONS SET IN. LLWS POSS SE. WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST. && .CTP WATCHES/WARNINGS/ADVISORIES... WIND CHILL WARNING UNTIL 11 AM EST SUNDAY FOR PAZ004>006-037- 041-042. WIND CHILL ADVISORY UNTIL 11 AM EST SUNDAY FOR PAZ010>012-017- 018-024-033. WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR PAZ019-025>028- 034>036-045-046-049>053-056>059-063>066. WIND CHILL ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST SUNDAY FOR PAZ019-025>028-034>036-045-046-049>053-056>059- 063>066. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024- 033. && $$ SYNOPSIS...FITZGERALD NEAR TERM...GRUMM SHORT TERM...GRUMM/FITZGERALD LONG TERM...FITZGERALD/GARTNER AVIATION...GRUMM
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
158 PM MST SAT FEB 13 2016 .UPDATE... ISSUED AT 158 PM MST SAT FEB 13 2016 STRONG WINDS NOTED ALONG COLD FRONT MOVING INTO NORTHEAST WY...GUSTING OVER 60 MPH FOR A BRIEF PERIOD IN SOME AREAS. BOTH HRRR AND RUC SHOW THESE STRONG WINDS MOVING ACROSS NORTHEAST WY DURING THE AFTERNOON AND INTO THE BLACK HILLS AREA LATE THIS AFTERNOON/EARLY EVENING AS THE FRONT CROSSES. SHOWERS ACCOMPANYING THE FRONT WILL ALSO HELP TO MIX STRONGER WINDS ALOFT DOWN. HAVE DECIDED TO ISSUE A HIGH WIND WARNING FOR NORTHEAST WY AND MUCH OF THE BLACK HILLS AREA. WINDS SHOULD DIMINISH WITH THE FRONT AS IT MOVES EAST OF THE BLACK HILLS AND INTO COOLER AND MORE STABLE AIR TO THE EAST. UPDATE ISSUED AT 1238 AM MST SAT FEB 13 2016 CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER FAR SOUTHWEST SK... WITH WARM FRONT EXTENDING SOUTHEAST INTO THE BLACK HILLS AREA AND SOUTHWEST SD. COLD FRONT EXTENDS SOUTHWARD ACROSS CENTRAL MT INTO NORTHWEST WY. UPPER LEVEL ANALYSIS SHOWS STRONG SHORTWAVE MOVING EAST- SOUTHEAST ACROSS CENTRAL MT...WITH STRONG JET WRAPPING AROUND IT FROM THE NORTHERN ROCKIES THROUGH SD. LATEST OBS SHOW TEMPS RANGING FROM THE UPPER TEENS IN THE LEMMON AREA TO THE 50S OVER CAMPBELL CO WY. THE FREEZING LINE RIGHT NOW EXTENDS FROM NEAR BELLE FOURCHE TO NORTH OF PHILIP AND THEN SOUTH- SOUTHEAST TO MELLETTE AND TODD COUNTIES IN SOUTH CENTRAL SD. KUDX RADAR SHOWING SOME PCPN FROM MEADE CO INTO HAAKON AND ZIEBACH COUNTIES...MOSTLY IN THE FORM OF RAIN...WITH SOME FREEZING RAIN OR SNOW LIKELY OVER NORTHEAST MEADE INTO ZIEBACH CO. REGIONAL RADARS SHOW MORE ACTIVITY DEVELOP TO THE WEST OVER SOUTH CENTRAL MT AND NORTH CENTRAL WY NEAR THE SHORTWAVE AND COLD FRONT. SOME STRONG WINDS HAVE ALSO BEEN NOTED NEAR THE FRONT AND WITH SHOWER ACTIVITY THERE...AS TEMPS HAVE RISEN INTO THE 50S AND LOWER 60S. THESE SHOWERS AND WIND WILL MOVE INTO NORTHEAST WY EARLY THIS AFTERNOON AND REACH THE BLACK HILLS AREA LATE IN THE AFTERNOON. A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED FOR THE STRONG WIND GUSTS EXPECTED WITH SHOWERS THIS AFTERNOON. UPDATE HAS BEEN SENT TO ADJUST PCPN TYPE THIS AFTERNOON BASED ON CURRENT TEMPS AND EXPECTED TRENDS. THE MAIN THREAT FOR FREEZING RAIN AND A LITTLE SNOW WILL BE FROM PERKINS INTO ZIEBACH COUNTIES THROUGH THE AFTERNOON. ICE ACCUMULATION UP TO A TENTH OF AN INCH IS STILL EXPECTED. HARDING COUNTY WILL SEE TEMPS RISE TO ABOVE FREEZING BY LATE AFTERNOON AS THE WARM FRONT MOVES THROUGH... EVENTUALLY SWITCHING PCPN TO ALL RAIN. SOME ADJUSTMENTS WERE ALSO MADE TO CLOUD COVER...WINDS...AND HIGH TEMPS. && .SHORT TERM...TODAY THROUGH SUNDAY NIGHT ISSUED AT 327 AM MST SAT FEB 13 2016 UPPER TROUGH CONTINUES ACROSS THE ERN HALF OF THE CONUS WITH NW FLOW OVER THE NRN PLAINS. A STRONG FAST MOVING SHORTWAVE IS CROSSING THE CASCADES INTO THE NRN ROCKIES ATTM. CANADIAN HIGH PRES IS SITTING ACROSS THE UPPER MIDWEST WITH A STRONG BAROCLINIC ZONE OVER THE CNTRL TO ERN DAKOTAS. WARM AIR ADVECTION HAS BEGUN OVER THE CWA AS THE FRONTAL BOUNDARY SLIDES E/NE. TEMPS AT 800MB HAVE RISEN ABOVE FREEZING ACROSS MOST OF THE CWA...AND WILL DO SO INTO CNTRL SD OVER THE NEXT 3 TO 6 HOURS. TEMPS WILL WARM ABOVE FREEZING TODAY ACROSS NE WY TO MUCH OF WRN SD...HOWEVER FREEZING TEMPS ARE PROGGED ACROSS PTNS OF NW/NCNTRL SD THROUGH MUCH OF TODAY. AS THE SHORTWAVE PUSHES THROUGH THE REGION TODAY...PRECIP WILL DEVELOP ESPECIALLY ACROSS THE NRN HALF OF THE AREA. WARM LOW LEVELS SHOW THIS WILL FALL AS RAIN. CONCERN IS LINGERING SUB-FREEZING TEMPS ACROSS THE NRN PARTS OF THE CWA WILL RESULT IN A PERIOD OF FREEZING RAIN ESPECIALLY THROUGH THE AFTERNOON. WILL KEEP WINTER WEATHER ADVISORY ISSUED YESTERDAY BUT HAVE EXPANDED IT ACROSS HARDING COUNTY WITH THE SREF/HRRR SHOWING PRECIP POTENTIALLY BEGINNING LATE THIS MORNING WHEN SURFACE TEMPS ARE STILL BELOW FREEZING. BEHIND THE SHORTWAVE ...SUB-FREEZING LOW LEVELS WILL QUICKLY PUSH BACK INTO THE REGION ENDING THE THREAT FOR FREEZING RAIN AS IT BECOMES ALL SNOW IN THE AFTERNOON/EVENING. PARTS OF NW/CNTRL SD COULD SEE 1 TO 3 INCHES OF ACCUMULATION BEFORE PRECIP ENDS DURING THE OVERNIGHT HOURS. WITH LOW LEVEL INSTABILITY THAT DEVELOPS...MAY EVEN A FEW LIGHTNING STRIKES. MODELS SHOWING 700-850MB WINDS REACHING 50KT BRIEFLY NEAR THE FRONTAL BOUNDARY WHICH WOULD CREATE A SHORT PERIOD OF STRONG WINDS FOR NOT MORE THAN AN HOUR OR SO. W/NW WINDS WILL CONTINUE ACROSS THE AREA SUNDAY AS LOW PRESSURE SITS EAST OF THE AREA. WARMER TEMPS NEAR THE SURFACE WILL ALLOW HIGHS TO REACH THE UPPER 30S TO UPPER 40S...HOWEVER COOLER 700MB TEMPS WILL RESULT IN INSTABILITY IN THE LOW LEVELS WHICH WILL ALLOW FOR UPSLOPING TO DEVELOP ACROSS THE NRN/WRN BLKHLS. PRECIP WILL BE RAIN EXCEPT SOME SNOW AT THE HIGHEST ELEVATIONS. THIS LIGHT PRECIP WILL LINGER INTO SUNDAY NIGHT. .LONG TERM...MONDAY THROUGH FRIDAY ISSUED AT 327 AM MST SAT FEB 13 2016 EASTERN NOAM TROUGH WILL BREAKDOWN IN THE PERIOD...ALLOWING MEAN RIDGING TO SPREAD EAST INTO CENTRAL NOAM. THIS WILL RESULT IN A TREND TO VERY MILD/DRY CONDS BY MID WEEK AS STAUNCH WAA SPREADS INTO THE NORTHERN PLAINS. BEFORE THIS OCCURS...ANOTHER NW FLOW IMPULSE WILL ADVECT ACROSS THE NORTHERN PLAINS...SUPPORTING RA/SN SHOWERS MON INTO TUE. VERY WARM WEATHER CAN BE EXPECTED BY WED AND ESP THUR. HIGHS ACROSS THE FA THUR LOOK TO APPROACH AND PASS 70 AT SOME LOCATIONS...ESP IN THE LEE OF THE BH WHERE DOWNSLOPING WILL BE IN PLACE AHEAD OF A DEEP SFC CYCLONE THAT WILL ADVECT EAST THROUGH THE REGION SPURRED BY AMPLIFIED ACTIVE FLOW OVER THE EASTERN PAC. THUR-FRI LOW PRESSURE SYSTEM MAY ALSO SUPPORT ANOTHER HIGH WIND EVENT IN THE REGION TOWARD THE END OF THE WORK WEEK GIVEN PROGGED CAA/PRESSURE RISE COUPLET. ACTIVE JET ACROSS THE PAC LOOKS TO SUPPORT MILD ZONAL FLOW THROUGH THE MIDDLE/END OF NEXT WEEK...KEEPING ARCTIC AIR BOTTLED UP IN NORTHERN CANADA AS RIDGING REMAINS CONFINED TO LOWER LATITUDES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY) ISSUED AT 1021 AM MST SAT FEB 13 2016 MVFR/IFR CIGS OVER NORTHWEST INTO CENTRAL SOUTH DAKOTA WILL CONTINUE THROUGH THIS AFTERNOON AND EVENING AS AREA OF SN/FZRA DEVELOPS. THE HEAVIEST PRECIPITATION WILL BE THIS AFTERNOON INTO TONIGHT. FOR NORTHEAST WYOMING INTO SOUTHWEST SOUTH DAKOTA...SHOWERS WILL DEVELOP THIS AFTERNOON/EVENING WITH LCL MVFR CIGS/VSBY. COLD FRONT CROSSES THE AREA LATE AFTERNOON/EVENING WITH A PERIOD OF GUSTY NORTHWEST WINDS. VFR CONDITIONS EXPECTED ACROSS THE AREA SUNDAY MORNING. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...WINTER WEATHER ADVISORY UNTIL 8 PM MST THIS EVENING FOR SDZ001- 002-014. HIGH WIND WARNING UNTIL 8 PM MST THIS EVENING FOR SDZ012-024>031- 072>074. WY...HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ054>058- 071. && $$ UPDATE...26 SHORT TERM...13 LONG TERM...JC AVIATION...7
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
237 PM CST SAT FEB 13 2016 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 235 PM CST SAT FEB 13 2016 FAIRLY ACTIVE SHORT TERM FORECAST FOR THE AREA AS TWO FEATURES WILL COMBINE TO PRODUCE MODERATE TO OCCASIONALLY HEAVY SNOWFALL OVER THE CWA. THE STRONG SHORTWAVE THAT WILL SLIDE SOUTHEAST ACROSS SOUTHWEST SOUTH DAKOTA IS STILL LOCATED IN CENTRAL MONTANA AT THIS TIME...AND IS LEADING TO A COUPLE AREAS OF PRECIPITATION IN EASTERN MONTANA (ONE ALONG THE WARM FRONT AND ANOTHER TIED TO THE SHORTWAVE AND COLD FRONT). CLOSER TO THE AREA...SEEING PRECIPITATION JUST TO THE WEST OF THE MISSOURI RIVER THAT IS SLOWLY MOVING EAST-SOUTHEAST. THIS PRECIPITATION IS DUE TO THE INITIAL AREA OF MID-LEVEL WARM AIR ADVECTION AHEAD OF THE WARM FRONT STRETCHING SOUTH-SOUTHEAST THROUGH FAR WESTERN SOUTH DAKOTA. WEBCAMS SHOW THAT THE PRECIPITATION TOWARDS HAAKON/STANLEY COUNTIES IS IN THE FORM OF RAIN AND WITH SURFACE TEMPERATURES IN THAT AREA AROUND OR ABOVE FREEZING...DON/T THINK THERE IS TOO MUCH FREEZING RAIN OCCURRING AT THIS POINT. FARTHER NORTH...RAP ANALYSIS SOUNDINGS INDICATE THE WARM NOSE ALOFT WEAKENS WHICH SHOULD TRANSITION THE PRECIP TO SNOW THE FARTHER NORTH YOU HEAD. OVER THE REST OF THE AREA...CLOUDS HAVE BEEN LOWERING WITH THE INCREASING LOW LEVEL MOISTURE AND DEPARTING SURFACE RIDGE. TEMPERATURES ARE STILL FAIRLY COLD OVER NORTHEAST SD...WHERE 2PM TEMPERATURES RANGE FROM THE UPPER SINGLE DIGITS AT K8D3 TO 13 AT KABR AND THEN 17 AT KMBG. MODELS CONTINUING TO STRUGGLE WITH THE TRACK/EVOLUTION OF THE SHORTWAVE IN MONTANA...WHICH LEADS TO SOME UNCERTAINTY IN THE FORECAST SNOWFALL OVER N.C./N.E. SOUTH DAKOTA THIS EVENING INTO THE OVERNIGHT HOURS. LATEST RUNS OF THE RAP AND 12Z GLOBAL MODELS HAVE TRENDED THE TRACK OF THE STRONGEST FORCING A LITTLE FARTHER TO THE SOUTHWEST AND IN SOME CASES ONLY BARELY BRUSHING SOUTHWESTERN SD. WHILE THAT BEST FORCING SLIDES SOUTHWEST OF MUCH OF THE AREA...STILL HAVE SOME SUPPORT FROM THE UPPER TROUGH AND ESPECIALLY FROM THE WARM AIR ADVECTION / ISENTROPIC ASCENT ALONG AND AHEAD OF THAT TROUGH THROUGH THE EARLY OVERNIGHT HOURS. FAIRLY STRONG LIFT WITH THE WAA (AND SEEN IN THE 700MB OMEGA) WITH FAVORABLE 850-500MB Q-VECTOR DIVERGENCE. THEREFORE...EXPECT TO SEE A FAIRLY QUICK HITTING (4-7HR PERIOD) AREA OF PRECIPITATION MOVING THROUGH THE AREA...ESPECIALLY THIS EVENING INTO THE EARLY OVERNIGHT HOURS. MODELS HAVE TRENDED QPF AMOUNTS TO THE NORTH WITH THE MOST RECENT RUNS...SOME EVEN SHOWING 12HR QPF AMOUNTS EXCEEDING 0.6IN BETWEEN MOBRIDGE/ABERDEEN. THAT POTENTIAL (LIKELY SOMEWHAT CONVECTIVELY DRIVEN WITH 750-500MB LAPSE RATES AROUND 7 C/KM) WILL NEED TO BE WATCHED THROUGH THE EVENING AND IF IT SETS UP AS SHOWN WITH SOME OF THE HIGHER RES RUNS...MAY NEED TO UPGRADE A FEW COUNTIES TO WARNINGS. WITH THAT FARTHER NORTH TREND...EXPECT A LITTLE LESS IMPACT FOR THE SOUTHWESTERN CWA...BUT STILL THINK THE POTENTIAL FOR FREEZING RAIN THROUGH THE FIRST PART OF THE EVENING BEFORE TRANSITIONING TO SNOW FOR A BRIEF PERIOD BEFORE ENDING. THAT NORTHWARD SHIFT SHOULD KEEP SNOWFALL AMOUNTS BELOW 2 INCHES FROM PIERRE AND SOUTHWEST (WHERE SOME AREAS WILL STAY MAINLY RAIN). AS FOR SNOWFALL AMOUNTS OVER THE NORTH CENTRAL AND NORTHEAST...HAVE A GENERAL 3-6 INCHES WITH SNOW RATIOS INCREASING FROM AROUND 10-1 AROUND THE MISSOURI RIVER TO THE 12-14 TO 1 RANGE OVER THE NORTHEAST. OVER THE NORTHEAST...A GOOD PORTION OF THE LIFT IS AT OR ABOVE THE DGZ...WHICH WILL LIKELY LEAD TO MORE COLUMNS IN THE SNOW PROCESS AND MORE POTENTIAL FOR COMPACTING (ALONG WITH AGGREGATION AS THE SNOW FALLS THROUGH THE CLOUD LAYER BELOW THE DGZ). THUS...DIDN/T WANT TO GO MUCH HIGHER THAN THE PREVIOUSLY MENTIONED VALUES ...ALTHOUGH RATIOS COULD BRIEFLY INCREASE IF THE FORCING ALIGNS A LITTLE LOWER AND IN THE DGZ. WITH THE HIGHER QPF AND RATIOS...HAVE NEAR WARNING SNOWFALL AMOUNTS (5.5-6IN) OVER MCPHERSON/EDMUNDS/BROWN/MARSHALL/DAY COUNTIES. WITH THE VARIABILITY IN THE MODEL RUNS TODAY...DIDN/T HAVE ENOUGH CONFIDENCE TO UPGRADE TO A WARNING AT THIS POINT AND THE EVENING SHIFT WILL NEED TO MONITOR FOR A POSSIBLE UPGRADE. IN ADDITION...WITH THE SNOW OCCURRING LATE THIS EVENING AND DURING THE EARLY OVERNIGHT HOURS...THOUGHT THE IMPACTS WOULD BE LOWER THAN IF IT OCCURRED DURING THE DAY. ONE OTHER ITEM TO MENTION WILL BE THE GUSTY SOUTH-SOUTHEAST WINDS INITIALLY THIS EVENING AHEAD OF THE TROUGH (GUSTS TO 25-30MPH). THAT WILL LEAD TO PATCHY/AREAS OF BLOWING SNOW AND WILL CONTINUE TO MENTION THAT IN THE FORECAST/WSW. FOR THE REST OF THE PERIOD...THE SNOW WILL DIMINISH FROM WEST TO EAST LATE TONIGHT AND THROUGH THE DAY ON SUNDAY (LARGELY OVER THE EASTERN HALF/THIRD OF THE CWA). A BROAD SURFACE TROUGH WILL BE OVER THE AREA AND LIMIT THE WINDS AND IN TURN ANY BLOWING SNOW CONCERNS. IN ADDITION...WITH THE WARM AIR OVER THE AREA BEHIND THE WARM FRONT THAT MOVED THROUGH...HIGHS WILL RISE INTO THE MID/UPPER 20S OVER THE FAR EAST TO THE LOWER 40S ALONG AND WEST OF THE MISSOURI RIVER. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 235 PM CST SAT FEB 13 2016 LOW TEMP FORECAST FOR SUNDAY NIGHT IS A BIT TRICKY. AREA WILL STILL BE IN A RELATIVELY MILD AIR MASS WITH 925MB TEMPS AROUND 0C TO +2C AND A LIGHT WEST TO SOUTHWEST SFC WIND. ALTHOUGH...WILL HAVE TO KEEP IN MIND THE FRESH COAT OF SNOW THAT WILL BE OVER MUCH OF THE AREA. THERE WILL BE SOME DEGREE OF CLOUD COVER AS WELL...SO TRYING TO FIGURE OUT WHICH VARIABLES HAVE THE BIGGEST IMPACT ON TEMPS IS TRICKY. WILL THEN BE WATCHING THE NEXT PIECE OF SHORTWAVE ENERGY WHICH WILL BE DROPPING SOUTHEAST THROUGH THE AREA MONDAY NIGHT. HAVE INCREASED POPS FOR THIS EVENT AS MODELS ARE IN PRETTY GOOD AGREEMENT ON TIMING AND PLACEMENT OF QPF. AGAIN...COULD BE DEALING WITH MIXED PRECIP ISSUES AS THERE WILL BE WARM AIR IN PLACE. YET ANOTHER WAVE MOVES THROUGH TUESDAY NIGHT BUT IS LOOKING RATHER WEAK AT THIS POINT. SUPERBLEND GAVE SLIGHT CHANCE POPS AND THIS LOOKS GOOD FOR THE TIME BEING. ONLY CHANGE HERE WAS TO REMOVE THE SLIGHT CHANCES THEY INITIAL GAVE ON TUESDAY AND HELD THINGS OFF TO TUESDAY NIGHT PER MODEL DATA. TEMPS THROUGHOUT THE PERIOD STAY ON THE MILD SIDE...ESPECIALLY BY THURSDAY WHEN MODELS TRY TO BRING IN SOME VERY MILD AIR. 925MB TEMPS AROUND +20C SHOW UP IN THE MODELS OVER SOUTHWEST AND SOUTH CENTRAL SD. SUPERBLEND TEMPS HAVE READINGS AS WARM AS THE 60S OVER THE SOUTHWEST CWA ON THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1149 AM CST SAT FEB 13 2016 EXPECT DETERIORATING CONDITIONS FROM WEST TO EAST THROUGH THE AFTERNOON AND EVENING ACROSS THE REGION...AS A STORM SYSTEM SLIDES EAST-SOUTHEAST ACROSS THE AREA. HAVE ALREADY STARTED TO SEE SOME REDUCTIONS IN VISIBILITY AT KMBG AND EXPECT VISIBILITIES TO FALL TO LOW END IFR AT ALL THE SITES AS THE HEAVIEST SNOW MOVES THROUGH. COULD BRIEFLY SEE LIFR VISIBILITIES FIRST OVER THE WEST LATE THIS AFTERNOON THROUGH LATE EVENING AND THEN AT KABR/KATY BETWEEN 02-08Z (COMBINATION OF THE HEAVY SNOW AND BLOWING SNOW BEFORE WINDS DIMINISH). EXPECT VISIBILITIES TO RAPIDLY IMPROVE OVER THE WEST AFTER MIDNIGHT AS THE SYSTEM SHIFTS TO THE EAST (VFR CONDITIONS WEST BY MID MORNING)...ALTHOUGH MVFR CONDITIONS WILL PREVAIL THROUGH SUNDAY MORNING OVER THE EAST. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR SDZ003- 004-009-015-016-033>036-045-048-051. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST SUNDAY FOR SDZ005>008-010-011-017>023-037. MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST SUNDAY FOR MNZ039-046. && $$ SHORT TERM...SRF LONG TERM...TDK AVIATION...SRF
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1220 PM CST SAT FEB 13 2016 .AVIATION... MVFR CIGS NOTED ACROSS THE SWRN TWO THIRDS OF THE CWFA THIS MORN/ AFTN...GENERALLY ALONG AND SOUTH OF THE WEAK FRONTAL BOUNDARY. AS THE LINE WEAKENS/MOVES BACK FURTHER INLAND THIS EVENING/OVERNIGHT WE COULD SEE WIDESPREAD LOWER/MVFR CIGS ACROSS SE TX BY SAT MORN. SOME SPOTS MIGHT SEE PATCHY FOG OVERNIGHT AS WELL...BUT FOG COULD BE MORE PREVALENT SUN MORN. 41 && .PREV DISCUSSION... /ISSUED 925 AM CST SAT FEB 13 2016/ UPDATE... FIRST VISIBILITY HAS IMPROVED SOUTH OF A FRONTAL BOUNDARY SO LET DENSE FOG ADVISORY EXPIRE. BASED ON 15Z SFC OBS...FRONTAL BOUNDARY LOCATED FROM LA GRANGE TO SUGAR LAND TO GALVESTON. LATEST 14Z HRRR HAS THIS BOUNDARY FAIRLY WELL RESOLVED AND BEGINS TO PUSH THE BOUNDARY BACK NORTH LATER THIS AFTERNOON AND TURNS WINDS TO SE. THERE MAY BE ENOUGH CLOUD COVER AND COOLER AIR TO KEEP MAX TEMPS IN THE 60S BUT MAY STILL FEEL HUMID WITH DEWPOINTS IN THE 50S SOUTH OF THE BOUNDARY. MAIN UPDATES TO THE FORECAST WERE TO ENSURE CONSISTENCY WITH ONGOING TRENDS AND LATEST SHORT RANGE GUIDANCE. OVERALL NOT A LOT OF CHANGE FROM THE PREVIOUS UPDATE. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 67 52 71 56 71 / 10 10 20 20 20 HOUSTON (IAH) 68 51 71 58 72 / 10 10 20 30 30 GALVESTON (GLS) 61 56 69 58 68 / 10 10 20 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...99 AVIATION/MARINE...41