Global model runs discussion

[AtlanticWind]

Atlantic hurricane season begins June 1
The Atlantic hurricane season starts in just over a week, and the long-range GFS model continues to suggest that the Western Caribbean will be capable of brewing the season's first "Invest" during the first week of June. The Madden Julian Oscillation (MJO), a pattern of increased thunderstorm activity near the Equator that moves around the globe in 30 - 60 days, is currently weak, but the latest GFS forecast predicts that the MJO will strengthen slightly in early June, and might be in a position to increase thunderstorm activity over the Western Caribbean then. While long range 10 - 16 day forecasts are notoriously unreliable, early June is a common time of year for the Western Caribbean to see a tropical disturbance form. Residents of Cuba, the Cayman Islands, Jamaica, Honduras, and Nicaragua should anticipate the possibility of a multi-day period of disturbed weather with heavy rainfall beginning around June 1.

Have a great Memorial Day weekend, everyone!

Jeff Masters


From Jeff Masers Blog

[Alyono]

12Z no longer has a well defined system, instead, it indicates a broad area of low pressure

[cycloneye]

This is from an official source.

FOR THE LAST COUPLE OF DAYS, EVERY RUN OF THE GFS HAS INCLUDED THE
FORMATION OF A TROPICAL SYSTEM OFF THE COAST OF PANAMA, MOVING TO NEAR FLORIDA.
TODAY, THE CANADIAN MODEL HAS DONE THE SAME. BECAUSE THE ATLANTIC TROPICAL
SEASON OFFICIALLY STARTS ON JUNE 1, AND BECAUSE THE UPPER-LEVEL CONDITIONS ARE
FAVORABLE FOR TROPICAL DEVELOPMENT, PEOPLE WITH INTERESTS ALONG THE FLORIDA AND
GULF COASTS SHOULD KEEP UPDATED WITH THE MOST CURRENT INFORMATION COMING OUT OF
THE NATIONAL HURRICANE CENTER AND LOCAL FORECAST OFFICES.

http://forecast.weather.gov/product.php ... suedby=THR

[Hurricane Alexis]

18z GFS shows nothing. Shows some lowering of pressures in the long range.

[floridasun78]

we see what happen .i reading setting maybe their for system by first week of june

[chaser1]

This is from an official source.

FOR THE LAST COUPLE OF DAYS, EVERY RUN OF THE GFS HAS INCLUDED THE
FORMATION OF A TROPICAL SYSTEM OFF THE COAST OF PANAMA, MOVING TO NEAR FLORIDA.
TODAY, THE CANADIAN MODEL HAS DONE THE SAME. BECAUSE THE ATLANTIC TROPICAL
SEASON OFFICIALLY STARTS ON JUNE 1, AND BECAUSE THE UPPER-LEVEL CONDITIONS ARE
FAVORABLE FOR TROPICAL DEVELOPMENT, PEOPLE WITH INTERESTS ALONG THE FLORIDA AND
GULF COASTS SHOULD KEEP UPDATED WITH THE MOST CURRENT INFORMATION COMING OUT OF
THE NATIONAL HURRICANE CENTER AND LOCAL FORECAST OFFICES.

http://forecast.weather.gov/product.php ... suedby=THR

Certainly right about one thing............ The Atlantic Tropical Season officially starts on June 1.

[Florida1118]

00z GFS picks it back up again. Starts festering around 240



Then moves North and consolidates a little


And the end result

[hurricanehunter69]

A very long and lengthy persistence for this storm continues! The 00Z still on it. http://mag.ncep.noaa.gov/Image.php?fhr= ... =&ps=model

[cycloneye]

Broad low pressure at 240 hours of 12z GFS.

[cycloneye]

12z GFS has dropped Caribbean area even if it still shows something there like a monsoonal gyre.

[ninel conde]

i imagine amanda is going to flood the carib with shear. cant imagine anything other than a weak low being able to exist.

[Yellow Evan]

i imagine amanda is going to flood the carib with shear. cant imagine anything other than a weak low being able to exist.

Why Amanda shear the Caribbean? Amanda is hundreds of miles away on the opposite side of the cost. And Amanda will be gone by then.

[ninel conde]

major in the east pac=major shear and it will last well past amanda's demise.

[Florida1118]

major in the east pac=major shear and it will last well past amanda's demise.

Is that based on an actually science or...the Caribbean is full of shear to begin with, so Amanda seems pretty irrelevant, especially in the time frame the low was suppose to develop.

[Alyono]

Now, how can the shear from Amanda last longer than Amanda's demise?

Some new science I missed?

[sunnyday]

So, is nothing going to happen from this after it was predicted to develop earlier in the week?

[Ntxw]

So, is nothing going to happen from this after it was predicted to develop earlier in the week?

I don't think anyone should have believed with certainty something was going to develop. The talk was about very long range (should always be with caution) and those should be taken with some skepticism. What it did show, and still does is areas of disturbed weather that MAY or may not organize in the Carib is all we should take from it.

[NDG]

GFS now shows development in the western Caribbean within its 6-10 day range now. GEM/CMC is on board but so far nothing from the ECMWF.

[ronjon]

GFS pretty consistently has shown development over the last 20 or so runs. Latest 06z has a 1004 mb low in the western carribean that weakens as it moves N-NE into the Cedar Key area. Why does it weaken? The 200 mb winds are screaming at 50 kts in the eastern GOM. Of course this is 10 days out so much will change. But a weak-moderate highly sheared TS is pretty much the norm for early season development.

http://mag.ncep.noaa.gov/Image.php?fhr=228&image=data%2Fgfs%2F06%2Fgfs_wnatl_228_850_vort_ht.gif&model=gfs&area=wnatl&param=850_vort_ht&group=Model+Guidance&preselected_formatted_cycle_date=20140526+06+UTC&imageSize=M&ps=model

[CourierPR]

The latest satellite image shows no precipitation in the Caribbean. Where will the moisture originate to feed any developing system?