lightningmanAB wrote:lightningmanAB wrote:So I am hoping that tomorrow, Tuesday, April 18, 2017 will be my first storm chase in Alberta for the 2017 season.
ECCC puts out a wonderful forecast discussion each day for the Prairies (updated in the morning and early afternoon each day).
From their report:
"TUESDAY A SHORTWAVE MOVES THROUGH THE SOUTH WITH
A CONVERGENCE AREA CURRENTLY PROGGED THROUGH CLARESHOLM, LETHBRIDGE
AND CYPRESS HILLS. LIFTING WITH 14 AND 2 GIVES CAPES NEAR 600 J/KG. "
I think the 14 and 2 is likely referring to the surface temp and dewpoint. I am hoping the area of convergence will be closer to Calgary. If it was all the way down in Claresholm and Lethbridge it would be too far of a drive. Without going into the details, based on what I see on the HRDPS and NAM3KM models I expect to see a little storm somewhere east of Calgary.
NAM3KM shows pockets of 500-600 CAPE on Tuesday late afternoon / early eve in the area which is enough to get my interest and hopes up.
EC's update this morning on the FOCN:IN THE AFTERNOON FROM THE FOOTHILLS
NEAR NORDEGG INTO THE LETHBRIDGE AND MEDICINE HAT REGIONS THERE IS A
RISK OF ISOLATED THUNDERSTORMS AS SBCAPES ARE NEAR 500 J/KG WITH
30-40 KNOTS OF SHEAR OVER 0-6 KM, ALTHOUGH MOISTURE IS SOMEWHAT
LIMITED NEAR THE SURFACE.
EC's update this afternoon on the FOCN:IN THE
AFTERNOON ALONG A CONVERGENCE TROUGH FROM THE FOOTHILLS
NEAR CALGARY INTO THE LETHBRIDGE AND MEDICINE HAT REGIONS THERE IS A
RISK OF ISOLATED THUNDERSTORMS AS SBCAPES ARE IN THE 500-600 J/KG
RANGE WITH 30-40 KNOTS OF 0-6 KM SHEAR. SURFACE DEWPOINTS HAVE
ALSO RISEN INTO THE LOW SINGLE DIGITS THIS MORNING OVER SOUTHEASTERN
ALBERTA. DEPTH OF MOISTURE IS QUESTIONABLE BUT GIVEN ALL THE
INGREDIENTS ABOVE SHOULD A STORM BE ABLE TO ACCESS THE AIRMASS TO
THE NORTHEAST OF THE CONVERGENCE TROUGH A MARGINALLY SEVERE STORM
ISN'T OUT OF THE QUESTION.
I drew a sounding and hodograph from RDPS model data for 3pm Calgary time to give me an idea of what I might expect:
Based on the Skew T Log P prognosis sounding for 3pm today there is enough CAPE for some thunderstorms.
It was a bit of a bust today. Moisture in the lower levels of the atmosphere was lacking. Also, the wind shear was a bit too strong for the weak amount of instability that we had. There were some thunderstorms around the region later in the evening due to a disturbance that approached from the west.