FXUS61 KALY 150442
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1241 AM EDT TUE JUL 15 2003

.DISCUSSION...
SOME SHOWERS FORMED ACROSS THE WESTERN MOHAWK VALLEY AND SOUTHERN 
ADIRONDACKS MONDAY EVENING.  THE RAPID UPDATE CYCLE MODEL SOUNDINGS 
WERE TOO DRY TO ACCURATELY DEPICT WHAT WAS HAPPENING.  THE MESOSCALE 
ETA FORECAST SOUNDINGS WERE A LITTLE MOISTER, BUT EVEN SO, DIDN'T 
HAVE ENOUGH INSTABILITY TO CATCH THE DEPTH OF THE CONVECTION.  RADAR 
ANIMATIONS BEFORE MIDNIGHT INDICATED THAT THESE SHOWERS WERE DYING 
QUICKLY.

OTHER THAN THAT, THERE WAS NOT EVEN MUCH CLOUDINESS IN EASTERN NEW 
YORK OR WESTERN NEW ENGLAND AROUND THE MIDNIGHT HOUR.  THE WATER 
VAPOR IMAGERY SUGGESTED THAT AN UNDERNOURISHED WAVE WAS MOVING ALONG 
THE EASTERN NEW ENGLAND COAST.  THERE WAS LITTLE ONSHORE 
PRECIPITATION ASSOCIATED WITH THIS FEATURE.  THE WATER VAPOR IMAGERY 
INDICATED A VORTICITY MAXIMUM NEAR THE UNITED STATES-CANADIAN BORDER 
JUST WEST OF THE GREAT LAKES.  SCATTERED STRONG CONVECTION WAS 
OCCURRING ALONG A COLD FRONT FROM THE WESTERN GREAT LAKES TO THE 
CENTRAL PLAINS.  IT WOULD APPEAR THAT THIS FRONT WOULD BE THE NEXT 
SIGNIFICANT SOURCE OF ANY PRECIPITATION IN THE COUNTY WARNING AREA.

MONDAY EVENING, A SHARP TROUGH WAS ANALYZED IN THE HIGH LEVELS OF 
THE ATMOSPHERE FROM SOUTHERN QUEBEC PROVINCE SOUTHWARD ACROSS 
CENTRAL NEW YORK STATE AND INTO THE CENTRAL VIRGINIA.  THE 
NORTHEASTERN UNITED STATES WAS IN THE CONVERGENT SECTION OF THE 
ASSOCIATED WIND MAXIMUM TO THE EAST OF THIS TROUGH, AND STRONG 
ANTICYLONIC VORTICITY ADVECTION WAS OCCURRING OVER THE EASTERN GREAT 
LAKES.  THE RAPID UPDATE CYCLE MODEL FORECAST THIS ANTICYCLONIC 
VORTICITY ADVECTION TO MOVE OVER CENTRAL NEW YORK AROUND DAYBREAK.  
LONGER-TERM MODELS SHOWED IT OVER MUCH OF THE ALBANY COUNTY WARNING 
AREA THIS AFTERNOON.  MID- AND UPPER-LEVEL SINKING WAS FORECAST IN 
EASTERN NEW YORK AND WESTERN NEW ENGLAND TODAY, WITH THE EXCEPTION
OF THE WESTERN ZONES TOWARD EVENING.  AT THAT TIME, THE APPROACHING 
COOL FRONT AND ITS ASSOCIATED DYNAMICS ARE FORECAST TO BEGIN TO 
AFFECT WESTERN AND CENTRAL NEW YORK.  THE LATEST RUN OF THE NESTED 
GRID MODEL, UNLIKE THE DRIER HOUR 12 UNIVERSAL COORDINATE TIME 
MONDAY RUN OF THE ETA BRINGS PRECIPITATION INTO WESTERN AND CENTRAL 
NEW YORK.  HOWEVER, THE NESTED GRID MAY BE TOO FAST AS THE LATEST 
RUNS OF THE CANADIAN REGIONAL, AVIATION, AND ETA MODELS ALL FORECAST 
PRECIPITATION FURTHER TO THE WEST TODAY.  THE ETA IS SLIGHTLY SLOWER 
THAN THE CANADIAN AND AVIATION, BUT THERE IS NOT A LOT OF DIFFERENCE 
BETWEEN THEM.  MONDAY'S ZONE FORECAST WAS FOR A DRY AND MOSTLY SUNNY 
DAY TODAY, AND THIS LOOKS LIKE IT SHOULD WORK OUT AS SUGGESTED.  THE
MOST RECENT CLIMATOLOGICAL-STATISTICAL FORECAST VALUES OF THE MODELS 
SUGGEST THAT MONDAY'S FORECAST SHOULD BE QUITE ACCURATE WITH ITS 
MAXIMUM TEMPERATURE FORECAST IN THE LOWER AND MIDDLE 80S.  THE 
MESOSCALE MODEL FORECAST SOUNDINGS INDICATED THAT THERE'LL BE ENOUGH 
MOISTURE AND HEATING TO GENERATE TOWERING CUMULUS CLOUDINESS THIS 
AFTERNOON.  BUT IT IS EXPECTED TO BE SCATTERED, AND THE MAIN IMPACT 
REGARDING WIDESPREAD CLOUD COVER WILL BE CIRRUS OVER THE WESTERN 
ZONES LATE IN THE DAY.  THE FORECAST SOUNDINGS SUGGEST A LIGHT SOUTH 
WIND IN THE EASTERN ZONES THIS AFTERNOON, AND A BIT STRONGER, SAY 10 
TO 15 MILES AN HOUR IN THE WEST.

THE UPPER-LEVEL TROUGH IS FORECAST TO SLIP EASTWARD OVER THE SURFACE 
COOL FRONT AS IT COMES INTO EASTERN NEW YORK AND WESTERN NEW ENGLAND 
TONIGHT (SO TYPICAL OF WARM SEASON COOL FRONTS).  THIS SHOULD HELP 
MAXIMIZE HYDROSTATIC INSTABILITY FOR AWHILE, BUT IT WILL TEND TO 
DECREASE THE SYNOPTIC DYNAMICS ALONG THE FRONT.  THE HEAVIEST 
PRECIPITATION, HALF TO THREE QUARTERS OF AN INCH, IS FORECAST TO BE 
IN WESTERN AND CENTRAL NEW YORK STATE TONIGHT.  AND AS THE 
UPPER-LEVEL TROUGH MOVES EVEN FURTHER EAST OF THE LOW-LEVEL FRONT 
WEDNESDAY, THE DYNAMICS WILL CONTINUE TO WANE.  SO THE FORECAST 
PRECIPITATION IS QUITE LIGHT WEDNESDAY, ESPECIALLY IN THE WESTERN 
ZONES WHERE THERE'S BARELY ANY MEASURABLE PRECIPITATION (ETA 
ENTIRELY DRY).

THE PREVIOUS FORECAST HAD INDICATED A CHANCE OF SHOWERS AND 
THUNDERSTORMS FOR TONIGHT AND WEDNESDAY.  IT SEEMS AS IF THE 
FORECAST MIGHT BE IMPROVED BY INDICATING LIKELY PROBABILITIES OF 
PRECIPITATION IN THE NORTHWESTERN PORTION OF THE COUNTY WARNING AREA 
AS IS SUGGESTED BY MODEL FORECASTS.  BUT THE CHANCE VALUES FOR 
WEDNESDAY SEEM REASONABLE IN VIEW OF THE WEAKENING DYNAMICS.  THE 
TEMPERATURE GUIDANCE OF THE PREVIOUS FORECAST LOOKS REASONABLE WHEN 
COMPARED WITH THE GUIDANCE FROM HOUR ZERO TUESDAY UNIVERSAL 
COORDINATION TIME RUN OF THE MODELS.

LOOKING FURTHER INTO THE WEEK, THE LATEST MODEL RUN OF THE CANADIAN 
GLOBAL, ETA, AND AVIATION ALL INDICATE DRY WEATHER FOR WEDNESDAY 
NIGHT AND THURSDAY.  HOWEVER, AN UPPER-LEVEL TROUGH, AND FAIRLY 
STRONG SURFACE COOL FRONT IS FORECAST TO MOVE TO THE VICINITY OF 
NORTHERN NEW YORK AND THE EASTERN GREAT LAKES THURSDAY EVENING.  THE 
CANADIAN, AVIATION, AND ETA ALL SUGGEST THE CHANCE OF LIGHT 
PRECIPITATION IN THE NORTH AND WEST PORTION OF THE COUNTY WARNING 
AREA THURSDAY NIGHT IN ASSOCIATION WITH THIS FEATURE.  MONDAY'S ZONE 
FORECAST INDICATED DRY WEATHER FOR THURSDAY NIGHT, AND THIS WILL NOT 
BE CHANGED AS ANY PRECIPITATION FORECAST ON THE LATEST MODEL RUN IS 
LIGHT AND CONFINED TO THE PERIPHERY OF THE COUNTY WARNING AREA.  THE 
AVIATION HAS PRECIPITATION FORECAST IN THE SOUTHERN HALF OF THE 
COUNTY WARNING AREA FRIDAY, THE CANADIAN EMPHASIZES PRECIPITATION 
OVER THE NORTH.  MONDAY'S ZONE FORECAST HAD A CHANCE OF SHOWERS AND 
THUNDERSTORMS FOR FRIDAY, SO NO CHANGES ARE LIKELY TO BE MADE.  THE 
CANADIAN AND AVIATION MODEL FORECASTS BEGIN TO DIVERGE LATE IN THE 
WEEK, AS THE CANADIAN IS MORE DEVELOPED AND SLOWER WITH A CYCLONE 
MOVING ACROSS SOUTHEASTERN CANADA.  THE AVIATION IS QUICKER TO 
RETURN NEW YORK AND WESTERN NEW ENGLAND TO A WARM ADVECTION REGIME 
OVER THE WEEKEND, AND IT THREATENS SOME PRECIPITATION IN THE 
SOUTHWEST PORTION OF THE COUNTY WARNING AREA SATURDAY.  THE CANADIAN 
SHOWS SOME LINGERING PRECIPITATION OVER NORTHEASTERN NEW YORK 
SATURDAY FROM THE DEPARTING CYCLONE.  IT WAS NOTED THAT THE HOUR 12 
UNIVERSAL COORDINATION TIME RUN OF THE EUROPEAN MODEL FORECAST 
FAVORED THE LATEST CANADIAN SOLUTION.  BOTTOM LINE, WITH SUCH 
UNCERTAINTY FOR THE WEEKEND, MONDAY'S FORECAST FOR LATE IN THE WEEK 
WILL REMAIN UNCHANGED.

.HYDROLOGIC OUTLOOK...WIDESPREAD HEAVY PRECIPITATION IS NOT FORECAST 
FOR THE FORESEEABLE FUTURE.  NO FLOODING IS ANTICIPATED.

.ALY...NONE.

HEMMERICH