textproduct: Raleigh

WHAT HAS CHANGED

* Updated Aviation discussion.

KEY MESSAGES

As of 230 AM Sunday...

1) A frontal system will bring the chance for rain across the area tonight and Monday.

2) A chance of showers/isolated thunderstorms at mid-week. Mild temperatures until a late week warm-up.

DISCUSSION

As of 230 AM Sunday...

KEY MESSAGE 1... A frontal system will bring the chance for rain across the area tonight and Monday.

Aloft, a s/w, located over the nrn Rockies as of 06Z Sun, will swing sewd across the Plains today, amplifying the parent trough in the process. This s/w may split/separate from the parent trough then continue ewd across the lwr MS Valley and Deep South as the trough and some s/w energy progress ewd across the region Mon/Mon night. At the surface, a cold front will approach from the NW late tonight and drop swd across the area on Mon as an area of low pressure slides ewd off the Carolina coast ahead of/along it. Ahead of the front, a trough will strengthen over the area this aft/eve before shifting sewd tonight.

Temperatures: Highs Mon will greatly depend on the front and associated precipitation, with a gradient of 10-15 degrees from N-S across the area. For now, have highs in the upr 60s across the north and low 80s across the south. Lows Mon night in the mid 40s to low 50s from N-S expected.

Highest chance for rain will be behind the surface cold front, more aligned with the axis of strongest 850mb frontogenesis as it moves sewd across the area and secondarily, best chance for showers and perhaps an isolated storm or two will be closer to the coast as the low tracks ewd and offshore. Cannot rule out a strong storm or two, mainly along the front and in closest proximity to the low Mon aft, where surface convergence is maximized. In the warm sector Mon aft/eve, the NAM continues to show steep low-level lapse rates, with 300-500 J/Kg of SBCAPE and ~50 kts of 0-6 Km Bulk Shear. North of the front the atmosphere should be too stable for storms to develop. The Day 2 SPC outlook has general thunder across the srn half of cntl NC, with the Marginal risk for an isolated strong storm or two still clipping srn Sampson county.

KEY MESSAGE 2... One more low chance of showers/isolated thunderstorms at mid-week. Mild temperatures until a late week warm- up.

A weak cold front is expected to bring a chance of showers and possibly isolated thunderstorms Wednesday afternoon into the evening. The moisture and instability again are forecast to be lacking. Thus, there is little expectation of widespread or significant rainfall. After the front passes Wednesday night, high pressure will bring a continuation of dry weather Thursday and beyond. Temperatures will be near normal for most of the week. However, much warmer or even hot weather is expected by next weekend when highs should reach well into the 80s. This warm-up and dry weather late week into next weekend will be courtesy of surface high pressure shifting into the western Atlantic.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

As of 530 AM Sunday...

24 hour TAF period: Any lingering sub-VFR conditions should quickly become VFR this morning, with VFR prevailing through the remainder of the TAF period. Otherwise, broken high clouds will clear from the NW this morning and winds will vary from swly to nwly and back through the TAF period.

Outlook: Sub-VFR conditions and rain (possibly some showers at KFAY) are expected with the passage of a frontal system tonight and Mon. Winds should increase Mon morn, with gusts of 15-25 kts in cold advection behind the front. Additional flight restrictions and rain are expected with the passage of another frontal system Wed into Thu. Otherwise, VFR conditions are expected.

RAH WATCHES/WARNINGS/ADVISORIES

None.