textproduct: Wilmington

WHAT HAS CHANGED

Trending towards slightly slower progression of systems for tonight and for early next week.

KEY MESSAGES

1) Showers and thunderstorms will occur ahead of a cold front that will move through the region tonight.

2) More showers and storms will occur Monday night into Tuesday ahead of the next cold front.

DISCUSSION

KEY MESSAGE 1) Mid level ridge across the region will get suppressed late in the day and into tonight as a somewhat disorganized short wave pushes eastward. Pre-frontal trough will cross the region this evening with a cold front lagging until later in the night, possibly not clearing the area until Saturday morning. Warm air aloft (500 mb and above), modest mid level lapse rates, and dew points remaining in the 50s will limit the amount of instability that may develop. And with most guidance indicating a somewhat slower progression, resulting in most if not all convection moving in after 00Z, then instability will be lessening. There remains the potential for gusty winds as these showers and thunderstorms move through. Cannot rule out isolated damaging wind gusts but confidence is low.

KEY MESSAGE 2) Short wave emerging from the central Rockies on Sunday night will deepen as it heads east northeast across the Plains and into the Great Lakes by Tuesday. While overall pattern is pretty stable, there has been a trend towards a bit more spread in the mid levels with this system as it gets this far east, which may be more representative of some timing uncertainty compared to system strength. The mean has certainly become slightly slower with the progression.

Given this, the chance of seeing precipitation reaching our forecast area on Monday are becoming less. Bulk of the showers and thunderstorms may not even move across the area until after midnight Monday night. If this timing verifies, then the potential for strong to severe storms will be greatly diminished, heading towards a diurnal minimum in instability. It does appears that a low level jet will push into the region on Monday night and weaken as it moves across the area. This may result in pretty good moisture transport which could mean that locally heavy rainfall may be a bigger concern. But still being out on day 4, there is plenty of time and room for subtle, but meaningful changes in how this system impacts the area.

With the slower progression, the associated cold front may not move across the forecast area until Tuesday morning. If it is slow enough, there may be a window for some instability to develop in southeast counties before the front clears the area. If that were to occur, then some stronger storms could not be ruled out.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

High and mid clouds will spread across the region through the day. Winds will become south southwest with some gusts at or above 20 kt. After 21Z a cumulus deck will move in and showers and thunderstorms will push through the area. With some uncertainty in timing and coverage of thunderstorms, have continued with a few hours of prob30 tsra and followed that with a few more hours of prevailing showers, although that might be generous at some sites. Any heavier showers and storms could bring temporary lower conditions. Otherwise, VFR is forecast to prevail until a cold front moves across the terminals in the latter part of the period. Expect MVFR ceilings to move in behind the front.

OUTLOOK....MVFR ceilings likely into Saturday. Thunderstorms possible Monday night into Tuesday.

ILN WATCHES/WARNINGS/ADVISORIES

OH...None. KY...None. IN...None.