SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 1244 PM CST Sun Dec 28 2025 Valid 301200Z - 311200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities appear less than 10 percent across the U.S. for Tuesday through Tuesday night. ...Discussion... Models indicate that the center of a broad and still deepening cyclone will migrate north-northwest of the St. Lawrence Valley, toward the southern Hudson Bay vicinity through this period. At mid-levels, it appears that the broadening circulation will be reinforced by a vigorous short wave perturbation digging from the higher latitudes. Surrounding this low, cyclonic flow will likely encompass most areas east of the Rockies through the offshore western Atlantic, with some further amplification across the Gulf Basin into the Caribbean and Bahamas. Beneath this regime, cool surface ridging entrenched across much of the southern Great Plains, Gulf Coast and Gulf Basin is forecast to only slowly begin to weaken. Upstream, a cyclonic circulation over the subtropical eastern Pacific may gradually begin to consolidate in advance of more notable short wave troughing digging across the mid-latitude eastern Pacific. However, a substantive northeastward acceleration of the low toward the California coast appears unlikely through at least early Wednesday, and mid-level ridging will generally be maintained across much of the interior West. While lower/mid-tropospheric moisture return emanating from the lower latitude eastern Pacific may overspread portions of the Southwest into Great Basin, it is still not clear that this will yield sufficient destabilization to support convection capable of producing lightning (although NAM forecast soundings around the Las Vegas, NV vicinity late Tuesday evening/overnight suggest that this might not be completely out of the question). ..Kerr.. 12/28/2025
