106
ACUS48 KWNS 110902
SWOD48
SPC AC 110900
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0400 AM CDT SAT JUL 11 2026
VALID 141200Z - 191200Z
..DISCUSSION
ENSEMBLE GUIDANCE CONTINUES TO INDICATE THAT THE CONUS-WIDE
MID-LEVEL RIDGE CENTERED OVER THE NORTH-CENTRAL UNITED STATES WILL
BUILD WESTWARD DURING THE UPCOMING WEEK IN RESPONSE TO A SERIES OF
MID-LEVEL TROUGHS MOVING THROUGH CENTRAL CANADA. THESE TROUGHS WILL
HELP TO CARVE OUT A SEASONABLY STRONG TROUGH ACROSS EASTERN CANADA.
BY THE END OF THE WEEK, THE US RIDGE WILL BE CENTERED OVER THE
ROCKIES WITH THE EASTERN CANADA TROUGH CENTERED OVER QUEBEC. THE
RESULT WILL BE A STRONG MID-LEVEL HEIGHT GRADIENT (AND STRONG
MID-LEVEL FLOW) STRETCHING FROM THE UPPER GREAT LAKES SOUTHEAST INTO
THE MID-ATLANTIC AND ENCOMPASSING NEW ENGLAND.
.. TUESDAY/DAY 4 -- NEW ENGLAND
MULTIPLE ENSEMBLE SYSTEMS CONTINUE TO SUPPORT A FAVORABLE SEVERE
WEATHER ENVIRONMENT BEING IN PLACE ACROSS NEW ENGLAND ON TUESDAY.
STRONG DIURNAL HEATING AND SOUTHWESTERLY SURFACE FLOW SHOULD ALLOW
SURFACE TEMPERATURES TO WARM INTO THE MID-80FS TO PERHAPS LOW-90FS
BY LATE AFTERNOON AHEAD OF A SEASONABLY STRONG SURFACE COLD FRONT.
AHEAD OF THE COLD FRONT, SURFACE DEWPOINT TEMPERATURES SHOULD RISE
INTO THE 60FS TO PERHAPS 70FS, LEADING TO MUCAPE BETWEEN 1000-2000
J/KG. CURRENT THINKING IS THAT THUNDERSTORMS WILL DEVELOP ALONG AND
AHEAD OF THE SURFACE COLD FRONT DURING THE AFTERNOON ACROSS QUEBEC
AND MOVE INTO NEW ENGLAND DURING THE LATE AFTERNOON BEFORE
DISSIPATING OVERNIGHT. STRONG VERTICAL SHEAR IN EXCESS OF 50 KNOTS
WILL COMBINE WITH STRONG INSTABILITY TO SUPPORT SEVERE
THUNDERSTORMS. THE MOST PROBABLE SCENARIO IS FOR ONE OR MORE BROKEN
LINES OF STORMS TO MOVE ACROSS THE REGION, WITH PERHAPS A FEW
EMBEDDED SUPERCELLS. ALL SEVERE HAZARDS SEEM POSSIBLE AT THIS TIME.
... FRIDAY/DAY 7 AND BEYOND -- UPPER GREAT LAKES INTO THE
MID-ATLANTIC ...
STRONG NORTHWEST FLOW WILL BE ESTABLISHED BETWEEN THE PREVIOUSLY
DESCRIBED WESTERN US RIDGE AND EASTERN CANADIAN TROUGH. RICH
BOUNDARY LAYER MOISTURE IS EXPECTED TO BE PRESENT TO THE SOUTH OF A
RESIDUAL COLD FRONT THAT WILL BE DRAPED SOMEWHERE FROM THE GREAT
LAKES SOUTHEAST INTO THE MID-ATLANTIC/SOUTHERN NEW ENGLAND. STRONG
DIURNAL HEATING EACH AFTERNOON WILL SUPPORT SCATTERED THUNDERSTORM
DEVELOPMENT CAPABLE OF PRODUCING DAMAGING OUTFLOWS. SEVERE
PROBABILITIES WERE INTRODUCED FOR DAY 7 WITH THIS OUTLOOK GIVEN
INCREASING CONFIDENCE IN THUNDERSTORMS DEVELOPING WITHIN SURFACE
TROUGHING EAST OF THE APPALACHIANS. THE EXACT LOCATION OF THESE
HIGHLIGHTS WILL LIKELY BE REFINED WITH SUBSEQUENT OUTLOOKS.
ADDITIONALLY, THE OVERALL LARGE-SCALE PATTERN SEEMS CONDUCIVE FOR
ONE OR MORE SHORTWAVE TROUGHS TO MOVE THROUGH THE BROADER
NORTHWESTERLY FLOW ACROSS THIS REGION. GIVEN THE (SEASONABLY)
STRONGLY UNSTABLE AND SHEARED ENVIRONMENT, ONE OR MORE SOUTHEASTWARD
MOVING MCSS MAY BE POSSIBLE DURING THE DAY 7 - DAY 10 PERIOD.
ENSEMBLE GUIDANCE VARIES SIGNIFICANTLY AS TO THE TIMING AND LOCATION
OF THESE POTENTIAL SHORT-WAVE TROUGHS, BUT THE OVERALL PATTERN WOULD
SUGGEST ADDITIONAL SEVERE WEATHER POTENTIAL AT THE END OF THE
FORECAST PERIOD AND IN THE DAYS THAT FOLLOW.
..MARSH.. 07/11/2026
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