textproduct: Raleigh

WHAT HAS CHANGED

As of 300 AM Monday...

Not as chilly, or wet, as previously forecast

KEY MESSAGES

As of 300 AM Monday...

1) Noticeably cooler, with light rain mainly across the nrn Piedmont and nrn Coastal Plain today, and drizzle or light rain over the nw Piedmont tonight

2) Much above normal temperatures expected Thursday through Sunday, with near record breaking high and high minimum temperatures

DISCUSSION

As of 300 AM Monday...

KEY MESSAGE 1... Noticeably cooler, with light rain mainly across the nrn Piedmont and nrn Coastal Plain today, and drizzle or light rain over the nw Piedmont tonight

A low amplitude shortwave trough now extending from IL to the Mid- South will progress generally ewd and across and offshore the srn Middle Atlantic through this evening, with the srn periphery of an associated precipitation shield that will only glance mainly the nrn half of cntl NC with light rain. Deterministic and ensemble model data have displayed in the past 24 hours a marked nwd shift with the footprint of that precipitation.

At the surface, a now 1038 mb Arctic high centered over Lake Ontario will remain favorably strong and located for classical cold air damming, as it progresses across the nrn Middle Atlantic and New England today. In the absence of any appreciable precipitation and diabatic influence at the latitude of most of cntl NC, however, it will be (mainly) dry CAD for most of the day, with a transition toward hybrid CAD as the high progresses offshore and light rain produces at least weak diabatic influence across nrn zones this afternoon-evening. Low-level isentropic lift/WAA, and 925 mb FGEN, will then probably deepen the associated saturated low-levels and produce periods of light rain or drizzle overnight-Tue morning over the nw Piedmont. Rainfall amounts will be light areawide, with perhaps a tenth of an inch over the far nrn Piedmont and nrn coastal Plain and a Trace to just a few hundredths otherwise and elsewhere. Given the lack of precipitation and diabatic cooling influence, temperatures today will be milder than previously forecast, 45-50F across nrn zones, and 50-60F across srn ones.

KEY MESSAGE 2... Much above normal temperatures expected Thursday through Sunday, with near record breaking high and high minimum temperatures

Model agreement is quite good that strong mid level ridging will build over and just off the Southeast U.S coast through the mid to late week, a function of a deep closed low digging over NW Mexico. Consensus is that our daily low level thicknesses each morning will be around 60 m above normal starting Fri and persisting through the weekend. This suggests high temps roughly 20 deg F above normal, with at least partial sunshine, which equates to daily highs in the upper 70s to lower 80s, with Fri likely the warmest day. Overnight lows are forecast to be even more above normal, by some 20-30 degrees, in the upper 50s to low 60s. These numbers will be generally just under record high values, but given the longwave pattern, later temperature forecasts could increase, possibly threatening these records.

There is a chance of some spotty showers late week into the weekend, however the lapse rates aloft will be tempered by the warm mid levels, and the surface ridging extending across the Southeast states should limit influx of Gulf-source moisture, thus the overall coverage of showers is expected to be low, isolated to widely scattered at most.

AVIATION /12Z MONDAY THROUGH FRIDAY/

As of 650 AM Monday...

Nely surface winds will continue to gust to around 20s kts at times this morning, as strong high pressure ridges swwd across the Carolinas. Otherwise, MVFR ceilings now extending across srn NC (including at FAY), and otherwise flanking cntl NC to both the west and east, will gradually fill in throughout cntl NC today. A little light rain will also be possible at Piedmont sites and RWI, and especially points nwd into VA later this afternoon through tonight. Continued nely flow will favor the development or lowering of ceilings into IFR to low MVFR range tonight-Tue morning. Periods of light rain/drizzle and mist will also accompany the lowest ceilings, most likely at INT and GSO.

Outlook: Low ceilings Tue morning will lift only slowly through MVFR over the Piedmont through the day Tue, with a quicker lifting and scattering to VFR at FAY and RWI. Stratus and/or fog will then be favored at ern sites (ie. FAY and RWI) each morning through the rest of the week.

CLIMATE

Record High Temperatures:

March 5: KGSO: 81/1967 KRDU: 83/1967

March 6: KGSO: 78/2022 KRDU: 82/1967 KFAY: 86/1918

March 7: KGSO: 81/1974 KRDU: 85/1974 KFAY: 84/1961

Record High Minimum Temperatures:

March 6: KGSO: 64/1967 KRDU: 64/1967 KFAY: 65/1961

March 7: KGSO: 63/1956 KRDU: 64/1956 KFAY: 65/1961

RAH WATCHES/WARNINGS/ADVISORIES