textproduct: Raleigh

WHAT HAS CHANGED

As of 134 AM Tuesday...

* No appreciable changes to the going forecast

KEY MESSAGES

As of 134 AM Tuesday...

1) Temperatures moderating by midweek, with potential low-end fire danger concerns Wed with gusts of 20-30 mph.

2) Chance for showers with a cold front moving across the region Thursday evening through Friday afternoon.

DISCUSSION

As of 134 AM Tuesday...

KEY MESSAGE 1... Temperatures moderating by midweek, with potential low-end fire danger concerns Wed with gusts of 20-30 mph.

High pressure over the Deep South today will migrate off the SE US coast by Wed. The below normal temperatures expected today and tonight, with 40s for highs and 30s for lows, will moderate on Wed and into Thu with highs well into the 50s and even 60s by Thu.

A fairly strong area of low pressure tracking southeast over the northern Great Lakes and Canada will tighten the pressure gradient over the region Wed. The low-level flow will increase to about 30- kt, supportive of gusts near the surface of 20-30 mph, highest across the Sandhills and Coastal Plain of central NC. In these regimes, even though southwest flow kicks in, models are too quick to bring in higher dewpoints. As such, we expect moisture recovery to be slower, blending in some of the drier guidance of the HRRR/HREF. With that, RH may dip into the low to middle 30s in the afternoon Wed. Combined with these gusts could warrant a low-end fire danger. The Southern Area Coordination Center, which provides fire outlooks, continues to highlight a moderate fire potential over all of NC. This may be tempered by mid/high clouds, limiting gusts, as well as recent wet soils from rain. Precipitation may develop Wed night with the approach of a warm front, but more widespread rain is expected Thu with a southward moving cold front.

KEY MESSAGE 2...Chance for showers with a cold front moving across the region Thursday evening through Friday afternoon.

Aloft, a s/w will track sewd across the Plains and MS Valley within the broad longwave trough Wed night/Thu, amplifying the longwave trough as it swings across the TN Valley, Appalachians, and mid- Atlantic/Southeast US Thu night and Fri. A trailing s/w will move slowly across the Deep South/Southeast US Fri and Sat. A northern stream s/w may move across the Great Lakes and Northeast US Sat night Sun as the parent low tracks ewd across Hudson Bay and nrn Quebec. At the surface, a warm front will lift across the area Wed night/Thu, while a low pressure system develops over the srn Plains. However, the medium-range model solutions varying wrt how the system progresses, with the general model consensus showing a low tracking ewd along the quasi-stationary WSW-ENE oriented frontal zone, extending from the srn mid-Atlantic to cntl TX, on Thu. There are still some significant model differences wrt areas of low pressure moving along the front and subsequently its swd/sewd progression Thu night/Fri, as well as with the high tracking ewd across the OH Valley, Northeast, and nrn mid-Atlantic. The front should be through the area by Fri night, while the high shifts offshore but continues to ridge swwd across the area. A low may develop off the Southeast US coast before lifting newd over the weekend. Another, stronger cold front should slide swd across the region Sun/Sun night as a 1040+ mb Arctic high tracks ewd across the Great Lakes, then continue ridging across the area as the high moves across the Northeast US Mon/Mon night. For now, the best chances for showers will be with the fropa between Thu evening/night and Fri aft/eve. There continues to be a negligible amount of CAPE off the GFS forecast soundings, and effective shear maxes out in the around 20 kt range. Chances for thunder remain too low to include in the forecast at this time. Otherwise, temperatures should generally remain near to above normal through the weekend, with the potential for some below normal temperatures in the wake of the front early next week.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

As of 640 AM Tuesday...

VFR conditions are expected to prevail over the 24 hour TAF period. High clouds should thicken and spread over the region through the day today. Otherwise, northwesterly winds may briefly gust this morning, especially in the Triad. Through the day, 6-10 kt winds will back to southwesterly. A 40-50kt southwesterly low level jet is expecting to develop and move over the region late tonight, bringing a threat for LLWS.

Outlook: Flight restrictions are expected to return Wednesday night though early Friday as a frontal zone moves through the region, bringing restrictions from rain and potentially low ceilings.

RAH WATCHES/WARNINGS/ADVISORIES

None.