[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 171724
SWODY2
SPC AC 171723

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1123 AM CST FRI DEC 17 2004

VALID 181200Z - 191200Z.

...NO TSTM AREAS FORECAST...

...SYNOPSIS...
UPPER TROUGH BECOMING BETTER DEFINED OVER THE ERN U.S. DURING THE
DAY 1 PERIOD WILL DEEPEN ON DAY 2 AS A PORTION OF THE ARCTIC VORTEX
MOVES SWD TOWARD THE GREAT LAKES REGION.  12Z ETA/GFS AGREE THAT THE
ERN TROUGH WILL DEEPEN...BUT THE GFS INDICATED A DEEPER TROUGH THAN
THE ETA BY 12Z SUNDAY. SURFACE LOW ASSOCIATED WITH PORTION OF
ARCTIC VORTEX IS EXPECTED TO DEVELOP OVER THE NRN GREAT LAKES BY
19/00Z AND THEN TRACK ESEWD TOWARD THE LOWER GREAT LAKES REGION. 
NWLY WINDS IN THE WAKE THIS SURFACE LOW AND TRAILING COLD FRONT WILL
SPREAD ARCTIC AIR MASS /-20 TO -26 AT 850 MB/ SSEWD ACROSS LAKES
SUPERIOR/MICHIGAN/HURON BY 12Z SUNDAY. 

A CONTINUED INFLUX OF STABLE CONTINENTAL POLAR AIR MASS SWD ACROSS
CONUS INTO GULF OF MEXICO WILL RESULT IN MINIMAL TSTM THREATS OVER
THE COUNTRY.  ONE EXCEPTION TO THIS NULL FORECAST IS DOWNWIND OF
LAKES SUPERIOR AND MICHIGAN LATE IN THE DAY 2 PERIOD ASSOCIATED WITH
LAKE EFFECT SNOW.  ETA/ETAKF POINT FORECAST SOUNDINGS SUGGESTED
BOUNDARY LAYER WILL BECOME DEEP ENOUGH WITH STEEPENING LOW-LEVEL
LAPSE RATES...AS THE COLD AIR SPREADS SSEWD ATOP WARM LAKE
TEMPERATURES /LS AT 4-5C AND 7C ACROSS SRN LM/ PER LATEST NOAA
COASTWATCH DATA ANALYSIS.  THUS...A FEW LIGHTNING STRIKES WILL BE
POSSIBLE WITHIN THE HEAVIEST LAKE EFFECT SNOW BANDS DOWNWIND OF
LAKES SUPERIOR AND MICHIGAN SATURDAY NIGHT.

..PETERS.. 12/17/2004

...NOTICE...
FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.