Tuesday, September 14, 2004
Hurricane Ivan looms large
Josh Larson @ 12:04 AM
Hurricane Ivan maintained its strength yesterday as its eye passed just miles away the western-most tip of Cuba. Meteorologists at the Tropical Prediction Center do not believe that enough of the core of the hurricane interacted with land to cause obvious weakening I am inclined to agree with their thinking based on satellite imagery.
At the time of the most recent advisory, the center of Ivan was 40 miles west-northwest from the western tip of Cuba, with sustained winds of 160mph (Category 5) and it was drifting to the northwest at a somewhat-slower 9mph.
Though I feel the meteorological community has a pretty good grasp on Ivan's (destructive) intentions at the moment, his forecast path, though still open to some question, is more easily discernible than is his intensity forecast.
Path
In recent days, models have converged on a forecast track remarkably similar to the track I was favoring in my post on September 8 (see track #3). It does, indeed, appear that Hurricane Ivan is likely to make landfall somewhere between New Orleans and Panama City very early on Thursday. Models have trended increasingly further west in the past several runs, so I now believe that the eye is more likely to come ashore (further west) in Louisiana (70%) than (further east) in Florida's panhandle (30%).
Intensity
Ivan's intensity forecast is a bit more of a challenge. Recall that both Hurricane Frances and Charley had tricks up their sleeves just before landfall. There are a few conflicting bits of atmospheric data: (1) Ivan is likely to experience increased westerly shear over the next 48 hours - exactly how much and whether it will be enough to appreciably impact Ivan is still unclear; (2) Ivan will continue to move, albeit slowly, over very warm water; (3) there are also a few indications that the depth of this warm water may be slightly less than recent water Ivan has encountered. The bottom line: I believe it is that it is unlikely that Ivan will strengthen further (simply because Ivan is close to as strong as they come), but there are indications that Ivan may weaken. My gut feeling is that Ivan will come ashore as a moderate to strong Category 4 storm; however, strange things happen, and I personally think it is equally likely that Ivan could weaken to a Category 3 storm as it is to remain as a Category 5 storm.
Impacts for DC?
It still appears probable that Ivan, once it makes landfall, will take a path that will take it more or less up the Appalachians. As such, significant rainfall is possible in the DC metro area from Friday through Sunday, with the highest likelihood for (flooding) rain over the western half of the area. In any case, expect mostly cloudy to overcast skies and windy conditions during this time period.
Until then, expect a rather unsettled remainder of the work week. Today will feature more clouds than sun with highs in the mid to upper 70's. Patchy light rain or drizzle is possible, though not probable, overnight as an easterly flow develops. Wednesday will feature mostly cloudy skies with a little light rain or drizzle possible, though the majority of the day should be dry; expect highs once again in the mid to upper 70's. Thursday may be a tick warmer, with highs expected to be in the low 80's, and a stray shower once again cannot be ruled out.
You will see the TPC's most recent Hurricane Ivan track forecast below:
Comments are closed for this archived entry | Link | 
Email this post
Email this post
