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WHAT HAS CHANGED

* Nil

KEY MESSAGES

1) 2 opportunities for light snow through Valentine's Day and Washington's Birthday holiday weekend

3) Mid-February thaw continues next week with best odds for precip (rain/mix) Wednesday-Friday

DISCUSSION

KEY MESSAGE 1: 2 opportunities for light snow through Valentine's Day and Washington's Birthday holiday weekend

#1: Progressive 500mb shortwave/vort max in the northern stream diving southeast from the Upper Great Lakes this afternoon should reach the Poconos by late tonight/06Z Saturday. This moisture deprived feature could produce an area of light snow <1" in clipper-style fashion driven by weak llvl WAA and upper level jet max across the northern tier and northeastern quadrant of the CWA by daybreak on Valentine's Day.

#2: A strong southern stream shortwave and associated surface low will track across the Mid-South and Southeast Sunday-Monday. The 13/00Z model and ensemble runs (including NBM, WPC, and AI) continue to point toward a potential swath of wintry wx on the north side of an area of enhanced precip focused from the Arkansas Delta to offshore the Carolinas. WSSI-P and NBM probs continue to highlight locations near/south of the PA Turnpike and along/east of I-81 with 20-30% chance of MINOR winter wx impacts and plowable (>2") snow. The other key uncertainty factor centers around ptype which could involve a rain to snow transition. If max temps in the low 40s are reached Sunday afternoon, that may also reduce road snow impact heading into Sunday night. The snow character would be wet/slushy given marginal thermal profiles initially above the freezing mark. Light snow could extend as far to the NW as the I99/US220 corridor. Key takeaway here is this does not appear to be a major winter storm, but could result in some minor travel impacts most likely across southern and eastern PA later Sunday into Sunday night/early Monday. KEY MESSAGE 2: Mid-February thaw continues next week with best odds for precip (rain/mix) Wednesday-Friday

Warmth is fcst to expand during the third week of February with some of the mildest temperatures forecast (45-55F) since early January. The warmup appears to have some staying power behind an influx of Pacific air being transported eastward via broad southwesterly flow aloft.

The precip pattern should dry out to start the week on Washington's Birthday with the southern stream system exiting off the East Coast and northern stream system tracking across ONT/QUE into northern New England. Model and ensemble data form a decent consensus around 2 bouts of potential mixed precip for mid to late week.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

Rare clear sky. High clouds are advancing on PA from the NW with the approach of a fast-moving and weak bump in the mid levels. This feature should make clouds and isolated SHSN tonight VCTY BFD. But, the main effects will be after the sfc trough associated with the shortwave passes. Clouds will (90% chc) lower to IFC at BFD and MVFR at everybody else except MDT and LNS. IPT is just about the only other spot which could see any snowflakes, but we are not expecting a reduction is vsby with any of those at IPT. Wind should go mainly calm early tonight, but pick up slightly on Sat behind the front. Clouds should break up some for the SE half of the area on Sat aftn. BFD and JST don't lose the low clouds. Then a system will roll south of PA, but spread some -SN/RA into the srn tier. IFR possible (50%) JST-MDT- LNS in -SN/RA Sun aftn & evening. MVFR expected (100%). Elsewhere, IFR cigs/visby unlikely (30%).

Outlook...

Mon...Low clouds linger much of the day. IFR expected NW.

Tue...Mainly VFR.

Wed...IFR -RA/cigs N, MVFR -RA/cigs elsewhere.

CTP WATCHES/WARNINGS/ADVISORIES

None.