textproduct: Wilmington

SYNOPSIS

A cold front will move through the area today, bringing rain and windy conditions. Another weather system will provide rain on Saturday, with much cooler weather expected for Sunday and beyond.

NEAR TERM /THROUGH TONIGHT/

610AM Update... A Wind Advisory has been issued for our far northwestern counties in west-central OH. This area has the best chance for wind gusts that could exceed 45 MPH.

Previous discussion... Through morning, the ILN CWA will remain in a warm advection pattern, with a 60-70 knot 850mb low-level jet in place over the forecast area. Most of this wind energy is failing to reach the surface as a result of an inversion, but 30-40 MPH wind gusts are being observed in the western half of the CWA, and should spread through much of the forecast area over the next few hours. Several narrow bands of heavy showers -- somewhat convective, though mostly thunderless -- are moving across Indiana. This precipitation will also spread east into the ILN CWA over the next few hours, though with instability very weak, it is unclear if these showers or convective lines will be capable of enhancing winds above and beyond the background flow.

A cold front is then forecast to move east through the forecast area today, generally between 14Z and 19Z. This front will shift winds to the west and at least temporarily produce some steep boundary layer lapse rates. As this cold advection begins, wind gusts of 35-45 mph are expected, with the strongest values generally near and north of the Interstate 70 corridor. The strongest winds should only last a few hours before the pressure gradient begins to relax and winds diminish fairly quickly in the mid to late afternoon.

Overall forecast confidence is reasonably strong, but medium in the expected strength of the gusts with the front. ILN criteria for a wind advisory (40 knots / 46 mph) is not in the forecast as of now, but is also not out of the realm of possibility.

Before the cold front arrives, early-day high temperatures will reach the lower to mid 60s. Some upper 60s in the far south or southeast may occur. These forecast temperatures will be close to record highs.

SHORT TERM /SATURDAY/

Cold advection will continue behind the front tonight, with min temps in the mid 30s to mid 40s by Saturday morning.

Surface high pressure will quickly move east of the area Saturday, as another weather system moves into the area. This will spread rain into the region from south to north on Saturday. Overall, precipitation amounts do not look notable, as the ILN CWA will be caught in between stronger forcing to the north and a stronger feed of moisture to the south.

LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/

Surface low ejects to the northeast Saturday night, limiting coverage in pcpn. Strong CAA will ensue with the mean H5 trough barreling through the Midwest region. A potent vort lobe will pivot through the Great Lakes/upper Ohio Valley region on Sunday. Additionally, deep layer northwesterly flow will transfer some moisture from the Great Lakes into our CWA, which may help with initializing light snowfall on Sunday. Thermal soundings not indicative of any heavy or persistent snowfall given that any saturation in the DGZ is shallow and only persists for a brief period of time on Sunday. Thus, do not highlight any snow accums in the grids for now. Note that conditions will be breezy once again on Sunday, with gusts of 25-35 MPH expected during the daytime.

H5 trough quickly shifts towards the Atlantic coast Sunday night, with broad surface high pressure settling back into the region for the beginning of the work week. The center of the surface high stretches across the southeastern CONUS, immediately resulting in return flow for our fa by Monday. This will allow for another warming trend to ensue through mid-week, but far less impressive than the current anomalous warmth the Ohio Valley is experiencing. Tuesday will be the warmest day, with highs generally peaking in the middle 40s to near 50.

The warming trend quickly ends as another H5 trough sinks down into the Ohio Valley Tuesday night into Wednesday, offering another chance for pcpn. A mix of rain and snow expected with this wave, but overall QPF remains light once again.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

The weather is active at the TAF sites this morning. A band of showers is working its way east through the area, bringing MVFR ceilings, occasionally MVFR to IFR visibilities, and gusty southwesterly winds. TEMPO groups have been included in the TAFs, where applicable, for this line of showers. Then, later in the day, a cold front is expected to move through between 16Z-18Z. This front will shift winds quickly to the west, with gusts of 30-35 knots. These winds will diminish by late afternoon, and become much lighter as they continue to shift to the north and then northwest.

Generally VFR conditions are expected overnight, but aviation conditions will diminish quickly Saturday morning as rain and low ceilings move into the area.

OUTLOOK...MVFR to IFR conditions are likely Saturday into Sunday.

ILN WATCHES/WARNINGS/ADVISORIES

OH...Wind Advisory until 4 PM EST this afternoon for OHZ026-034-035- 042>044. KY...None. IN...None.