ALTHOUGH UPPER RIDGE BECAME MORE AMPLIFIED OVER ERN SEA BOARD THIS EVE...THE LARGE SCALE CONUS PATTERN WILL BECOME INCREASINGLY DEAMPLIFIED INTO FRI. PATTERN HIGHLIGHTED BY WEAK TROFFING FROM PAC NW THRU MIN...AND RIDGING OVER ERN 1/RD OF U.S. PRIMARY BAND OF WESTERLIES HAVE SHIFTED TO NRN U.S WITH A SERIES OF LOWS/IMPULSES RIDING EWD THRU THIS BAND. THIS INCLUDES LOW OVER NE MOST IDAHO/ADJACENT CANADA AND ANOTHER ENTERING NRN MOST MINN ERODING THE RIDGE FROM W-E. IN SRN STREAM...SHORT WAVE TROUGH EXITING EWD FROM OH VALLEY WITH A WEAK SHORTWAVE MOVING EWD ACROSS GULF. MID/UPPER RIDGE WILL REMAIN IN PLACE OVER THE SE STATES OVERNIGHT. OH VALLEY SHORTWAVE WILL WEAKEN AS IT ADVANCES TO THE E/SE AND INTO RIDGE ON FRIDAY...BRUSHING LOCAL AREA DURING AFTN. THE NAM AND GFS MOS GUIDANCE DEPICT AN INCREASE IN DEEP LAYER MOISTURE (WITH THE NAM MORE ROBUST). IN ITS WAKE...DEEP LAYER RIDGING WILL NUDGE BACK WEST AND STRENGTHEN ACROSS THE REGION ON SATURDAY WITH A MARKED DECREASE IN MID/UPPER LAYER MOISTURE...ALBEIT LOW LEVEL REMAINS RELATIVELY MOIST. THIS REFLECTED IN MODEL SOUNDINGS. I.E. GFS TAE PWAT AT 00Z FRI IS 0.94 INCHES INCREASING TO 1.41 AT 18Z FRI...THEN DROPPING TO 1.21 AT 12Z SAT...AND TO 1.03 INCH PWAT AT 00Z SUN. AT LOWER LEVELS... AS SRN STREAM SHORTWAVE`S MOVES EWD OVERNIGHT...THEY WILL SERVE TO SHUNT RIDGE OF HIGH PRESSURE OVER CWA FURTHER SWD THIS EVE SETTLING OVER THE CENTRAL FL LATE OVERNIGHT. AS EXPECTED LOCAL PRESSURE CONTS TO WEAKEN. A COLD FRONT ACCOMPANYING ABOVE SHORT WAVE WILL ADVANCE THROUGH MUCH OF THE NORTHEAST...BEFORE SLOWING OR STALLING ON FRI WHERE IT WILL BE LOCATED FROM MID ATLC COAST THRU OHIO RIVER AND INTO THE SOUTH CENTRAL PLAINS.